1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *      NET3    Protocol independent device support routines.
4  *
5  *	Derived from the non IP parts of dev.c 1.0.19
6  *              Authors:	Ross Biro
7  *				Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
8  *				Mark Evans, <evansmp@uhura.aston.ac.uk>
9  *
10  *	Additional Authors:
11  *		Florian la Roche <rzsfl@rz.uni-sb.de>
12  *		Alan Cox <gw4pts@gw4pts.ampr.org>
13  *		David Hinds <dahinds@users.sourceforge.net>
14  *		Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
15  *		Adam Sulmicki <adam@cfar.umd.edu>
16  *              Pekka Riikonen <priikone@poesidon.pspt.fi>
17  *
18  *	Changes:
19  *              D.J. Barrow     :       Fixed bug where dev->refcnt gets set
20  *                                      to 2 if register_netdev gets called
21  *                                      before net_dev_init & also removed a
22  *                                      few lines of code in the process.
23  *		Alan Cox	:	device private ioctl copies fields back.
24  *		Alan Cox	:	Transmit queue code does relevant
25  *					stunts to keep the queue safe.
26  *		Alan Cox	:	Fixed double lock.
27  *		Alan Cox	:	Fixed promisc NULL pointer trap
28  *		????????	:	Support the full private ioctl range
29  *		Alan Cox	:	Moved ioctl permission check into
30  *					drivers
31  *		Tim Kordas	:	SIOCADDMULTI/SIOCDELMULTI
32  *		Alan Cox	:	100 backlog just doesn't cut it when
33  *					you start doing multicast video 8)
34  *		Alan Cox	:	Rewrote net_bh and list manager.
35  *              Alan Cox        :       Fix ETH_P_ALL echoback lengths.
36  *		Alan Cox	:	Took out transmit every packet pass
37  *					Saved a few bytes in the ioctl handler
38  *		Alan Cox	:	Network driver sets packet type before
39  *					calling netif_rx. Saves a function
40  *					call a packet.
41  *		Alan Cox	:	Hashed net_bh()
42  *		Richard Kooijman:	Timestamp fixes.
43  *		Alan Cox	:	Wrong field in SIOCGIFDSTADDR
44  *		Alan Cox	:	Device lock protection.
45  *              Alan Cox        :       Fixed nasty side effect of device close
46  *					changes.
47  *		Rudi Cilibrasi	:	Pass the right thing to
48  *					set_mac_address()
49  *		Dave Miller	:	32bit quantity for the device lock to
50  *					make it work out on a Sparc.
51  *		Bjorn Ekwall	:	Added KERNELD hack.
52  *		Alan Cox	:	Cleaned up the backlog initialise.
53  *		Craig Metz	:	SIOCGIFCONF fix if space for under
54  *					1 device.
55  *	    Thomas Bogendoerfer :	Return ENODEV for dev_open, if there
56  *					is no device open function.
57  *		Andi Kleen	:	Fix error reporting for SIOCGIFCONF
58  *	    Michael Chastain	:	Fix signed/unsigned for SIOCGIFCONF
59  *		Cyrus Durgin	:	Cleaned for KMOD
60  *		Adam Sulmicki   :	Bug Fix : Network Device Unload
61  *					A network device unload needs to purge
62  *					the backlog queue.
63  *	Paul Rusty Russell	:	SIOCSIFNAME
64  *              Pekka Riikonen  :	Netdev boot-time settings code
65  *              Andrew Morton   :       Make unregister_netdevice wait
66  *                                      indefinitely on dev->refcnt
67  *              J Hadi Salim    :       - Backlog queue sampling
68  *				        - netif_rx() feedback
69  */
70 
71 #include <linux/uaccess.h>
72 #include <linux/bitmap.h>
73 #include <linux/capability.h>
74 #include <linux/cpu.h>
75 #include <linux/types.h>
76 #include <linux/kernel.h>
77 #include <linux/hash.h>
78 #include <linux/slab.h>
79 #include <linux/sched.h>
80 #include <linux/sched/mm.h>
81 #include <linux/mutex.h>
82 #include <linux/rwsem.h>
83 #include <linux/string.h>
84 #include <linux/mm.h>
85 #include <linux/socket.h>
86 #include <linux/sockios.h>
87 #include <linux/errno.h>
88 #include <linux/interrupt.h>
89 #include <linux/if_ether.h>
90 #include <linux/netdevice.h>
91 #include <linux/etherdevice.h>
92 #include <linux/ethtool.h>
93 #include <linux/skbuff.h>
94 #include <linux/kthread.h>
95 #include <linux/bpf.h>
96 #include <linux/bpf_trace.h>
97 #include <net/net_namespace.h>
98 #include <net/sock.h>
99 #include <net/busy_poll.h>
100 #include <linux/rtnetlink.h>
101 #include <linux/stat.h>
102 #include <net/dsa.h>
103 #include <net/dst.h>
104 #include <net/dst_metadata.h>
105 #include <net/gro.h>
106 #include <net/pkt_sched.h>
107 #include <net/pkt_cls.h>
108 #include <net/checksum.h>
109 #include <net/xfrm.h>
110 #include <net/tcx.h>
111 #include <linux/highmem.h>
112 #include <linux/init.h>
113 #include <linux/module.h>
114 #include <linux/netpoll.h>
115 #include <linux/rcupdate.h>
116 #include <linux/delay.h>
117 #include <net/iw_handler.h>
118 #include <asm/current.h>
119 #include <linux/audit.h>
120 #include <linux/dmaengine.h>
121 #include <linux/err.h>
122 #include <linux/ctype.h>
123 #include <linux/if_arp.h>
124 #include <linux/if_vlan.h>
125 #include <linux/ip.h>
126 #include <net/ip.h>
127 #include <net/mpls.h>
128 #include <linux/ipv6.h>
129 #include <linux/in.h>
130 #include <linux/jhash.h>
131 #include <linux/random.h>
132 #include <trace/events/napi.h>
133 #include <trace/events/net.h>
134 #include <trace/events/skb.h>
135 #include <trace/events/qdisc.h>
136 #include <trace/events/xdp.h>
137 #include <linux/inetdevice.h>
138 #include <linux/cpu_rmap.h>
139 #include <linux/static_key.h>
140 #include <linux/hashtable.h>
141 #include <linux/vmalloc.h>
142 #include <linux/if_macvlan.h>
143 #include <linux/errqueue.h>
144 #include <linux/hrtimer.h>
145 #include <linux/netfilter_netdev.h>
146 #include <linux/crash_dump.h>
147 #include <linux/sctp.h>
148 #include <net/udp_tunnel.h>
149 #include <linux/net_namespace.h>
150 #include <linux/indirect_call_wrapper.h>
151 #include <net/devlink.h>
152 #include <linux/pm_runtime.h>
153 #include <linux/prandom.h>
154 #include <linux/once_lite.h>
155 #include <net/netdev_rx_queue.h>
156 
157 #include "dev.h"
158 #include "net-sysfs.h"
159 
160 static DEFINE_SPINLOCK(ptype_lock);
161 struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
162 struct list_head ptype_all __read_mostly;	/* Taps */
163 
164 static int netif_rx_internal(struct sk_buff *skb);
165 static int call_netdevice_notifiers_extack(unsigned long val,
166 					   struct net_device *dev,
167 					   struct netlink_ext_ack *extack);
168 static struct napi_struct *napi_by_id(unsigned int napi_id);
169 
170 /*
171  * The @dev_base_head list is protected by @dev_base_lock and the rtnl
172  * semaphore.
173  *
174  * Pure readers hold dev_base_lock for reading, or rcu_read_lock()
175  *
176  * Writers must hold the rtnl semaphore while they loop through the
177  * dev_base_head list, and hold dev_base_lock for writing when they do the
178  * actual updates.  This allows pure readers to access the list even
179  * while a writer is preparing to update it.
180  *
181  * To put it another way, dev_base_lock is held for writing only to
182  * protect against pure readers; the rtnl semaphore provides the
183  * protection against other writers.
184  *
185  * See, for example usages, register_netdevice() and
186  * unregister_netdevice(), which must be called with the rtnl
187  * semaphore held.
188  */
189 DEFINE_RWLOCK(dev_base_lock);
190 EXPORT_SYMBOL(dev_base_lock);
191 
192 static DEFINE_MUTEX(ifalias_mutex);
193 
194 /* protects napi_hash addition/deletion and napi_gen_id */
195 static DEFINE_SPINLOCK(napi_hash_lock);
196 
197 static unsigned int napi_gen_id = NR_CPUS;
198 static DEFINE_READ_MOSTLY_HASHTABLE(napi_hash, 8);
199 
200 static DECLARE_RWSEM(devnet_rename_sem);
201 
dev_base_seq_inc(struct net * net)202 static inline void dev_base_seq_inc(struct net *net)
203 {
204 	while (++net->dev_base_seq == 0)
205 		;
206 }
207 
dev_name_hash(struct net * net,const char * name)208 static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
209 {
210 	unsigned int hash = full_name_hash(net, name, strnlen(name, IFNAMSIZ));
211 
212 	return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
213 }
214 
dev_index_hash(struct net * net,int ifindex)215 static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
216 {
217 	return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
218 }
219 
rps_lock_irqsave(struct softnet_data * sd,unsigned long * flags)220 static inline void rps_lock_irqsave(struct softnet_data *sd,
221 				    unsigned long *flags)
222 {
223 	if (IS_ENABLED(CONFIG_RPS))
224 		spin_lock_irqsave(&sd->input_pkt_queue.lock, *flags);
225 	else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
226 		local_irq_save(*flags);
227 }
228 
rps_lock_irq_disable(struct softnet_data * sd)229 static inline void rps_lock_irq_disable(struct softnet_data *sd)
230 {
231 	if (IS_ENABLED(CONFIG_RPS))
232 		spin_lock_irq(&sd->input_pkt_queue.lock);
233 	else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
234 		local_irq_disable();
235 }
236 
rps_unlock_irq_restore(struct softnet_data * sd,unsigned long * flags)237 static inline void rps_unlock_irq_restore(struct softnet_data *sd,
238 					  unsigned long *flags)
239 {
240 	if (IS_ENABLED(CONFIG_RPS))
241 		spin_unlock_irqrestore(&sd->input_pkt_queue.lock, *flags);
242 	else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
243 		local_irq_restore(*flags);
244 }
245 
rps_unlock_irq_enable(struct softnet_data * sd)246 static inline void rps_unlock_irq_enable(struct softnet_data *sd)
247 {
248 	if (IS_ENABLED(CONFIG_RPS))
249 		spin_unlock_irq(&sd->input_pkt_queue.lock);
250 	else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
251 		local_irq_enable();
252 }
253 
netdev_name_node_alloc(struct net_device * dev,const char * name)254 static struct netdev_name_node *netdev_name_node_alloc(struct net_device *dev,
255 						       const char *name)
256 {
257 	struct netdev_name_node *name_node;
258 
259 	name_node = kmalloc(sizeof(*name_node), GFP_KERNEL);
260 	if (!name_node)
261 		return NULL;
262 	INIT_HLIST_NODE(&name_node->hlist);
263 	name_node->dev = dev;
264 	name_node->name = name;
265 	return name_node;
266 }
267 
268 static struct netdev_name_node *
netdev_name_node_head_alloc(struct net_device * dev)269 netdev_name_node_head_alloc(struct net_device *dev)
270 {
271 	struct netdev_name_node *name_node;
272 
273 	name_node = netdev_name_node_alloc(dev, dev->name);
274 	if (!name_node)
275 		return NULL;
276 	INIT_LIST_HEAD(&name_node->list);
277 	return name_node;
278 }
279 
netdev_name_node_free(struct netdev_name_node * name_node)280 static void netdev_name_node_free(struct netdev_name_node *name_node)
281 {
282 	kfree(name_node);
283 }
284 
netdev_name_node_add(struct net * net,struct netdev_name_node * name_node)285 static void netdev_name_node_add(struct net *net,
286 				 struct netdev_name_node *name_node)
287 {
288 	hlist_add_head_rcu(&name_node->hlist,
289 			   dev_name_hash(net, name_node->name));
290 }
291 
netdev_name_node_del(struct netdev_name_node * name_node)292 static void netdev_name_node_del(struct netdev_name_node *name_node)
293 {
294 	hlist_del_rcu(&name_node->hlist);
295 }
296 
netdev_name_node_lookup(struct net * net,const char * name)297 static struct netdev_name_node *netdev_name_node_lookup(struct net *net,
298 							const char *name)
299 {
300 	struct hlist_head *head = dev_name_hash(net, name);
301 	struct netdev_name_node *name_node;
302 
303 	hlist_for_each_entry(name_node, head, hlist)
304 		if (!strcmp(name_node->name, name))
305 			return name_node;
306 	return NULL;
307 }
308 
netdev_name_node_lookup_rcu(struct net * net,const char * name)309 static struct netdev_name_node *netdev_name_node_lookup_rcu(struct net *net,
310 							    const char *name)
311 {
312 	struct hlist_head *head = dev_name_hash(net, name);
313 	struct netdev_name_node *name_node;
314 
315 	hlist_for_each_entry_rcu(name_node, head, hlist)
316 		if (!strcmp(name_node->name, name))
317 			return name_node;
318 	return NULL;
319 }
320 
netdev_name_in_use(struct net * net,const char * name)321 bool netdev_name_in_use(struct net *net, const char *name)
322 {
323 	return netdev_name_node_lookup(net, name);
324 }
325 EXPORT_SYMBOL(netdev_name_in_use);
326 
netdev_name_node_alt_create(struct net_device * dev,const char * name)327 int netdev_name_node_alt_create(struct net_device *dev, const char *name)
328 {
329 	struct netdev_name_node *name_node;
330 	struct net *net = dev_net(dev);
331 
332 	name_node = netdev_name_node_lookup(net, name);
333 	if (name_node)
334 		return -EEXIST;
335 	name_node = netdev_name_node_alloc(dev, name);
336 	if (!name_node)
337 		return -ENOMEM;
338 	netdev_name_node_add(net, name_node);
339 	/* The node that holds dev->name acts as a head of per-device list. */
340 	list_add_tail(&name_node->list, &dev->name_node->list);
341 
342 	return 0;
343 }
344 
__netdev_name_node_alt_destroy(struct netdev_name_node * name_node)345 static void __netdev_name_node_alt_destroy(struct netdev_name_node *name_node)
346 {
347 	list_del(&name_node->list);
348 	kfree(name_node->name);
349 	netdev_name_node_free(name_node);
350 }
351 
netdev_name_node_alt_destroy(struct net_device * dev,const char * name)352 int netdev_name_node_alt_destroy(struct net_device *dev, const char *name)
353 {
354 	struct netdev_name_node *name_node;
355 	struct net *net = dev_net(dev);
356 
357 	name_node = netdev_name_node_lookup(net, name);
358 	if (!name_node)
359 		return -ENOENT;
360 	/* lookup might have found our primary name or a name belonging
361 	 * to another device.
362 	 */
363 	if (name_node == dev->name_node || name_node->dev != dev)
364 		return -EINVAL;
365 
366 	netdev_name_node_del(name_node);
367 	synchronize_rcu();
368 	__netdev_name_node_alt_destroy(name_node);
369 
370 	return 0;
371 }
372 
netdev_name_node_alt_flush(struct net_device * dev)373 static void netdev_name_node_alt_flush(struct net_device *dev)
374 {
375 	struct netdev_name_node *name_node, *tmp;
376 
377 	list_for_each_entry_safe(name_node, tmp, &dev->name_node->list, list)
378 		__netdev_name_node_alt_destroy(name_node);
379 }
380 
381 /* Device list insertion */
list_netdevice(struct net_device * dev)382 static void list_netdevice(struct net_device *dev)
383 {
384 	struct netdev_name_node *name_node;
385 	struct net *net = dev_net(dev);
386 
387 	ASSERT_RTNL();
388 
389 	write_lock(&dev_base_lock);
390 	list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
391 	netdev_name_node_add(net, dev->name_node);
392 	hlist_add_head_rcu(&dev->index_hlist,
393 			   dev_index_hash(net, dev->ifindex));
394 	write_unlock(&dev_base_lock);
395 
396 	netdev_for_each_altname(dev, name_node)
397 		netdev_name_node_add(net, name_node);
398 
399 	/* We reserved the ifindex, this can't fail */
400 	WARN_ON(xa_store(&net->dev_by_index, dev->ifindex, dev, GFP_KERNEL));
401 
402 	dev_base_seq_inc(net);
403 }
404 
405 /* Device list removal
406  * caller must respect a RCU grace period before freeing/reusing dev
407  */
unlist_netdevice(struct net_device * dev,bool lock)408 static void unlist_netdevice(struct net_device *dev, bool lock)
409 {
410 	struct netdev_name_node *name_node;
411 	struct net *net = dev_net(dev);
412 
413 	ASSERT_RTNL();
414 
415 	xa_erase(&net->dev_by_index, dev->ifindex);
416 
417 	netdev_for_each_altname(dev, name_node)
418 		netdev_name_node_del(name_node);
419 
420 	/* Unlink dev from the device chain */
421 	if (lock)
422 		write_lock(&dev_base_lock);
423 	list_del_rcu(&dev->dev_list);
424 	netdev_name_node_del(dev->name_node);
425 	hlist_del_rcu(&dev->index_hlist);
426 	if (lock)
427 		write_unlock(&dev_base_lock);
428 
429 	dev_base_seq_inc(dev_net(dev));
430 }
431 
432 /*
433  *	Our notifier list
434  */
435 
436 static RAW_NOTIFIER_HEAD(netdev_chain);
437 
438 /*
439  *	Device drivers call our routines to queue packets here. We empty the
440  *	queue in the local softnet handler.
441  */
442 
443 DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
444 EXPORT_PER_CPU_SYMBOL(softnet_data);
445 
446 #ifdef CONFIG_LOCKDEP
447 /*
448  * register_netdevice() inits txq->_xmit_lock and sets lockdep class
449  * according to dev->type
450  */
451 static const unsigned short netdev_lock_type[] = {
452 	 ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
453 	 ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
454 	 ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
455 	 ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
456 	 ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
457 	 ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
458 	 ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
459 	 ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
460 	 ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
461 	 ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
462 	 ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
463 	 ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
464 	 ARPHRD_FCFABRIC, ARPHRD_IEEE80211, ARPHRD_IEEE80211_PRISM,
465 	 ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET, ARPHRD_PHONET_PIPE,
466 	 ARPHRD_IEEE802154, ARPHRD_VOID, ARPHRD_NONE};
467 
468 static const char *const netdev_lock_name[] = {
469 	"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
470 	"_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
471 	"_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
472 	"_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
473 	"_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
474 	"_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
475 	"_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
476 	"_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
477 	"_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
478 	"_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
479 	"_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
480 	"_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
481 	"_xmit_FCFABRIC", "_xmit_IEEE80211", "_xmit_IEEE80211_PRISM",
482 	"_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET", "_xmit_PHONET_PIPE",
483 	"_xmit_IEEE802154", "_xmit_VOID", "_xmit_NONE"};
484 
485 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
486 static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
487 
netdev_lock_pos(unsigned short dev_type)488 static inline unsigned short netdev_lock_pos(unsigned short dev_type)
489 {
490 	int i;
491 
492 	for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
493 		if (netdev_lock_type[i] == dev_type)
494 			return i;
495 	/* the last key is used by default */
496 	return ARRAY_SIZE(netdev_lock_type) - 1;
497 }
498 
netdev_set_xmit_lockdep_class(spinlock_t * lock,unsigned short dev_type)499 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
500 						 unsigned short dev_type)
501 {
502 	int i;
503 
504 	i = netdev_lock_pos(dev_type);
505 	lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
506 				   netdev_lock_name[i]);
507 }
508 
netdev_set_addr_lockdep_class(struct net_device * dev)509 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
510 {
511 	int i;
512 
513 	i = netdev_lock_pos(dev->type);
514 	lockdep_set_class_and_name(&dev->addr_list_lock,
515 				   &netdev_addr_lock_key[i],
516 				   netdev_lock_name[i]);
517 }
518 #else
netdev_set_xmit_lockdep_class(spinlock_t * lock,unsigned short dev_type)519 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
520 						 unsigned short dev_type)
521 {
522 }
523 
netdev_set_addr_lockdep_class(struct net_device * dev)524 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
525 {
526 }
527 #endif
528 
529 /*******************************************************************************
530  *
531  *		Protocol management and registration routines
532  *
533  *******************************************************************************/
534 
535 
536 /*
537  *	Add a protocol ID to the list. Now that the input handler is
538  *	smarter we can dispense with all the messy stuff that used to be
539  *	here.
540  *
541  *	BEWARE!!! Protocol handlers, mangling input packets,
542  *	MUST BE last in hash buckets and checking protocol handlers
543  *	MUST start from promiscuous ptype_all chain in net_bh.
544  *	It is true now, do not change it.
545  *	Explanation follows: if protocol handler, mangling packet, will
546  *	be the first on list, it is not able to sense, that packet
547  *	is cloned and should be copied-on-write, so that it will
548  *	change it and subsequent readers will get broken packet.
549  *							--ANK (980803)
550  */
551 
ptype_head(const struct packet_type * pt)552 static inline struct list_head *ptype_head(const struct packet_type *pt)
553 {
554 	if (pt->type == htons(ETH_P_ALL))
555 		return pt->dev ? &pt->dev->ptype_all : &ptype_all;
556 	else
557 		return pt->dev ? &pt->dev->ptype_specific :
558 				 &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
559 }
560 
561 /**
562  *	dev_add_pack - add packet handler
563  *	@pt: packet type declaration
564  *
565  *	Add a protocol handler to the networking stack. The passed &packet_type
566  *	is linked into kernel lists and may not be freed until it has been
567  *	removed from the kernel lists.
568  *
569  *	This call does not sleep therefore it can not
570  *	guarantee all CPU's that are in middle of receiving packets
571  *	will see the new packet type (until the next received packet).
572  */
573 
dev_add_pack(struct packet_type * pt)574 void dev_add_pack(struct packet_type *pt)
575 {
576 	struct list_head *head = ptype_head(pt);
577 
578 	spin_lock(&ptype_lock);
579 	list_add_rcu(&pt->list, head);
580 	spin_unlock(&ptype_lock);
581 }
582 EXPORT_SYMBOL(dev_add_pack);
583 
584 /**
585  *	__dev_remove_pack	 - remove packet handler
586  *	@pt: packet type declaration
587  *
588  *	Remove a protocol handler that was previously added to the kernel
589  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
590  *	from the kernel lists and can be freed or reused once this function
591  *	returns.
592  *
593  *      The packet type might still be in use by receivers
594  *	and must not be freed until after all the CPU's have gone
595  *	through a quiescent state.
596  */
__dev_remove_pack(struct packet_type * pt)597 void __dev_remove_pack(struct packet_type *pt)
598 {
599 	struct list_head *head = ptype_head(pt);
600 	struct packet_type *pt1;
601 
602 	spin_lock(&ptype_lock);
603 
604 	list_for_each_entry(pt1, head, list) {
605 		if (pt == pt1) {
606 			list_del_rcu(&pt->list);
607 			goto out;
608 		}
609 	}
610 
611 	pr_warn("dev_remove_pack: %p not found\n", pt);
612 out:
613 	spin_unlock(&ptype_lock);
614 }
615 EXPORT_SYMBOL(__dev_remove_pack);
616 
617 /**
618  *	dev_remove_pack	 - remove packet handler
619  *	@pt: packet type declaration
620  *
621  *	Remove a protocol handler that was previously added to the kernel
622  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
623  *	from the kernel lists and can be freed or reused once this function
624  *	returns.
625  *
626  *	This call sleeps to guarantee that no CPU is looking at the packet
627  *	type after return.
628  */
dev_remove_pack(struct packet_type * pt)629 void dev_remove_pack(struct packet_type *pt)
630 {
631 	__dev_remove_pack(pt);
632 
633 	synchronize_net();
634 }
635 EXPORT_SYMBOL(dev_remove_pack);
636 
637 
638 /*******************************************************************************
639  *
640  *			    Device Interface Subroutines
641  *
642  *******************************************************************************/
643 
644 /**
645  *	dev_get_iflink	- get 'iflink' value of a interface
646  *	@dev: targeted interface
647  *
648  *	Indicates the ifindex the interface is linked to.
649  *	Physical interfaces have the same 'ifindex' and 'iflink' values.
650  */
651 
dev_get_iflink(const struct net_device * dev)652 int dev_get_iflink(const struct net_device *dev)
653 {
654 	if (dev->netdev_ops && dev->netdev_ops->ndo_get_iflink)
655 		return dev->netdev_ops->ndo_get_iflink(dev);
656 
657 	return dev->ifindex;
658 }
659 EXPORT_SYMBOL(dev_get_iflink);
660 
661 /**
662  *	dev_fill_metadata_dst - Retrieve tunnel egress information.
663  *	@dev: targeted interface
664  *	@skb: The packet.
665  *
666  *	For better visibility of tunnel traffic OVS needs to retrieve
667  *	egress tunnel information for a packet. Following API allows
668  *	user to get this info.
669  */
dev_fill_metadata_dst(struct net_device * dev,struct sk_buff * skb)670 int dev_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
671 {
672 	struct ip_tunnel_info *info;
673 
674 	if (!dev->netdev_ops  || !dev->netdev_ops->ndo_fill_metadata_dst)
675 		return -EINVAL;
676 
677 	info = skb_tunnel_info_unclone(skb);
678 	if (!info)
679 		return -ENOMEM;
680 	if (unlikely(!(info->mode & IP_TUNNEL_INFO_TX)))
681 		return -EINVAL;
682 
683 	return dev->netdev_ops->ndo_fill_metadata_dst(dev, skb);
684 }
685 EXPORT_SYMBOL_GPL(dev_fill_metadata_dst);
686 
dev_fwd_path(struct net_device_path_stack * stack)687 static struct net_device_path *dev_fwd_path(struct net_device_path_stack *stack)
688 {
689 	int k = stack->num_paths++;
690 
691 	if (WARN_ON_ONCE(k >= NET_DEVICE_PATH_STACK_MAX))
692 		return NULL;
693 
694 	return &stack->path[k];
695 }
696 
dev_fill_forward_path(const struct net_device * dev,const u8 * daddr,struct net_device_path_stack * stack)697 int dev_fill_forward_path(const struct net_device *dev, const u8 *daddr,
698 			  struct net_device_path_stack *stack)
699 {
700 	const struct net_device *last_dev;
701 	struct net_device_path_ctx ctx = {
702 		.dev	= dev,
703 	};
704 	struct net_device_path *path;
705 	int ret = 0;
706 
707 	memcpy(ctx.daddr, daddr, sizeof(ctx.daddr));
708 	stack->num_paths = 0;
709 	while (ctx.dev && ctx.dev->netdev_ops->ndo_fill_forward_path) {
710 		last_dev = ctx.dev;
711 		path = dev_fwd_path(stack);
712 		if (!path)
713 			return -1;
714 
715 		memset(path, 0, sizeof(struct net_device_path));
716 		ret = ctx.dev->netdev_ops->ndo_fill_forward_path(&ctx, path);
717 		if (ret < 0)
718 			return -1;
719 
720 		if (WARN_ON_ONCE(last_dev == ctx.dev))
721 			return -1;
722 	}
723 
724 	if (!ctx.dev)
725 		return ret;
726 
727 	path = dev_fwd_path(stack);
728 	if (!path)
729 		return -1;
730 	path->type = DEV_PATH_ETHERNET;
731 	path->dev = ctx.dev;
732 
733 	return ret;
734 }
735 EXPORT_SYMBOL_GPL(dev_fill_forward_path);
736 
737 /**
738  *	__dev_get_by_name	- find a device by its name
739  *	@net: the applicable net namespace
740  *	@name: name to find
741  *
742  *	Find an interface by name. Must be called under RTNL semaphore
743  *	or @dev_base_lock. If the name is found a pointer to the device
744  *	is returned. If the name is not found then %NULL is returned. The
745  *	reference counters are not incremented so the caller must be
746  *	careful with locks.
747  */
748 
__dev_get_by_name(struct net * net,const char * name)749 struct net_device *__dev_get_by_name(struct net *net, const char *name)
750 {
751 	struct netdev_name_node *node_name;
752 
753 	node_name = netdev_name_node_lookup(net, name);
754 	return node_name ? node_name->dev : NULL;
755 }
756 EXPORT_SYMBOL(__dev_get_by_name);
757 
758 /**
759  * dev_get_by_name_rcu	- find a device by its name
760  * @net: the applicable net namespace
761  * @name: name to find
762  *
763  * Find an interface by name.
764  * If the name is found a pointer to the device is returned.
765  * If the name is not found then %NULL is returned.
766  * The reference counters are not incremented so the caller must be
767  * careful with locks. The caller must hold RCU lock.
768  */
769 
dev_get_by_name_rcu(struct net * net,const char * name)770 struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
771 {
772 	struct netdev_name_node *node_name;
773 
774 	node_name = netdev_name_node_lookup_rcu(net, name);
775 	return node_name ? node_name->dev : NULL;
776 }
777 EXPORT_SYMBOL(dev_get_by_name_rcu);
778 
779 /* Deprecated for new users, call netdev_get_by_name() instead */
dev_get_by_name(struct net * net,const char * name)780 struct net_device *dev_get_by_name(struct net *net, const char *name)
781 {
782 	struct net_device *dev;
783 
784 	rcu_read_lock();
785 	dev = dev_get_by_name_rcu(net, name);
786 	dev_hold(dev);
787 	rcu_read_unlock();
788 	return dev;
789 }
790 EXPORT_SYMBOL(dev_get_by_name);
791 
792 /**
793  *	netdev_get_by_name() - find a device by its name
794  *	@net: the applicable net namespace
795  *	@name: name to find
796  *	@tracker: tracking object for the acquired reference
797  *	@gfp: allocation flags for the tracker
798  *
799  *	Find an interface by name. This can be called from any
800  *	context and does its own locking. The returned handle has
801  *	the usage count incremented and the caller must use netdev_put() to
802  *	release it when it is no longer needed. %NULL is returned if no
803  *	matching device is found.
804  */
netdev_get_by_name(struct net * net,const char * name,netdevice_tracker * tracker,gfp_t gfp)805 struct net_device *netdev_get_by_name(struct net *net, const char *name,
806 				      netdevice_tracker *tracker, gfp_t gfp)
807 {
808 	struct net_device *dev;
809 
810 	dev = dev_get_by_name(net, name);
811 	if (dev)
812 		netdev_tracker_alloc(dev, tracker, gfp);
813 	return dev;
814 }
815 EXPORT_SYMBOL(netdev_get_by_name);
816 
817 /**
818  *	__dev_get_by_index - find a device by its ifindex
819  *	@net: the applicable net namespace
820  *	@ifindex: index of device
821  *
822  *	Search for an interface by index. Returns %NULL if the device
823  *	is not found or a pointer to the device. The device has not
824  *	had its reference counter increased so the caller must be careful
825  *	about locking. The caller must hold either the RTNL semaphore
826  *	or @dev_base_lock.
827  */
828 
__dev_get_by_index(struct net * net,int ifindex)829 struct net_device *__dev_get_by_index(struct net *net, int ifindex)
830 {
831 	struct net_device *dev;
832 	struct hlist_head *head = dev_index_hash(net, ifindex);
833 
834 	hlist_for_each_entry(dev, head, index_hlist)
835 		if (dev->ifindex == ifindex)
836 			return dev;
837 
838 	return NULL;
839 }
840 EXPORT_SYMBOL(__dev_get_by_index);
841 
842 /**
843  *	dev_get_by_index_rcu - find a device by its ifindex
844  *	@net: the applicable net namespace
845  *	@ifindex: index of device
846  *
847  *	Search for an interface by index. Returns %NULL if the device
848  *	is not found or a pointer to the device. The device has not
849  *	had its reference counter increased so the caller must be careful
850  *	about locking. The caller must hold RCU lock.
851  */
852 
dev_get_by_index_rcu(struct net * net,int ifindex)853 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
854 {
855 	struct net_device *dev;
856 	struct hlist_head *head = dev_index_hash(net, ifindex);
857 
858 	hlist_for_each_entry_rcu(dev, head, index_hlist)
859 		if (dev->ifindex == ifindex)
860 			return dev;
861 
862 	return NULL;
863 }
864 EXPORT_SYMBOL(dev_get_by_index_rcu);
865 
866 /* Deprecated for new users, call netdev_get_by_index() instead */
dev_get_by_index(struct net * net,int ifindex)867 struct net_device *dev_get_by_index(struct net *net, int ifindex)
868 {
869 	struct net_device *dev;
870 
871 	rcu_read_lock();
872 	dev = dev_get_by_index_rcu(net, ifindex);
873 	dev_hold(dev);
874 	rcu_read_unlock();
875 	return dev;
876 }
877 EXPORT_SYMBOL(dev_get_by_index);
878 
879 /**
880  *	netdev_get_by_index() - find a device by its ifindex
881  *	@net: the applicable net namespace
882  *	@ifindex: index of device
883  *	@tracker: tracking object for the acquired reference
884  *	@gfp: allocation flags for the tracker
885  *
886  *	Search for an interface by index. Returns NULL if the device
887  *	is not found or a pointer to the device. The device returned has
888  *	had a reference added and the pointer is safe until the user calls
889  *	netdev_put() to indicate they have finished with it.
890  */
netdev_get_by_index(struct net * net,int ifindex,netdevice_tracker * tracker,gfp_t gfp)891 struct net_device *netdev_get_by_index(struct net *net, int ifindex,
892 				       netdevice_tracker *tracker, gfp_t gfp)
893 {
894 	struct net_device *dev;
895 
896 	dev = dev_get_by_index(net, ifindex);
897 	if (dev)
898 		netdev_tracker_alloc(dev, tracker, gfp);
899 	return dev;
900 }
901 EXPORT_SYMBOL(netdev_get_by_index);
902 
903 /**
904  *	dev_get_by_napi_id - find a device by napi_id
905  *	@napi_id: ID of the NAPI struct
906  *
907  *	Search for an interface by NAPI ID. Returns %NULL if the device
908  *	is not found or a pointer to the device. The device has not had
909  *	its reference counter increased so the caller must be careful
910  *	about locking. The caller must hold RCU lock.
911  */
912 
dev_get_by_napi_id(unsigned int napi_id)913 struct net_device *dev_get_by_napi_id(unsigned int napi_id)
914 {
915 	struct napi_struct *napi;
916 
917 	WARN_ON_ONCE(!rcu_read_lock_held());
918 
919 	if (napi_id < MIN_NAPI_ID)
920 		return NULL;
921 
922 	napi = napi_by_id(napi_id);
923 
924 	return napi ? napi->dev : NULL;
925 }
926 EXPORT_SYMBOL(dev_get_by_napi_id);
927 
928 /**
929  *	netdev_get_name - get a netdevice name, knowing its ifindex.
930  *	@net: network namespace
931  *	@name: a pointer to the buffer where the name will be stored.
932  *	@ifindex: the ifindex of the interface to get the name from.
933  */
netdev_get_name(struct net * net,char * name,int ifindex)934 int netdev_get_name(struct net *net, char *name, int ifindex)
935 {
936 	struct net_device *dev;
937 	int ret;
938 
939 	down_read(&devnet_rename_sem);
940 	rcu_read_lock();
941 
942 	dev = dev_get_by_index_rcu(net, ifindex);
943 	if (!dev) {
944 		ret = -ENODEV;
945 		goto out;
946 	}
947 
948 	strcpy(name, dev->name);
949 
950 	ret = 0;
951 out:
952 	rcu_read_unlock();
953 	up_read(&devnet_rename_sem);
954 	return ret;
955 }
956 
957 /**
958  *	dev_getbyhwaddr_rcu - find a device by its hardware address
959  *	@net: the applicable net namespace
960  *	@type: media type of device
961  *	@ha: hardware address
962  *
963  *	Search for an interface by MAC address. Returns NULL if the device
964  *	is not found or a pointer to the device.
965  *	The caller must hold RCU or RTNL.
966  *	The returned device has not had its ref count increased
967  *	and the caller must therefore be careful about locking
968  *
969  */
970 
dev_getbyhwaddr_rcu(struct net * net,unsigned short type,const char * ha)971 struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
972 				       const char *ha)
973 {
974 	struct net_device *dev;
975 
976 	for_each_netdev_rcu(net, dev)
977 		if (dev->type == type &&
978 		    !memcmp(dev->dev_addr, ha, dev->addr_len))
979 			return dev;
980 
981 	return NULL;
982 }
983 EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
984 
dev_getfirstbyhwtype(struct net * net,unsigned short type)985 struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
986 {
987 	struct net_device *dev, *ret = NULL;
988 
989 	rcu_read_lock();
990 	for_each_netdev_rcu(net, dev)
991 		if (dev->type == type) {
992 			dev_hold(dev);
993 			ret = dev;
994 			break;
995 		}
996 	rcu_read_unlock();
997 	return ret;
998 }
999 EXPORT_SYMBOL(dev_getfirstbyhwtype);
1000 
1001 /**
1002  *	__dev_get_by_flags - find any device with given flags
1003  *	@net: the applicable net namespace
1004  *	@if_flags: IFF_* values
1005  *	@mask: bitmask of bits in if_flags to check
1006  *
1007  *	Search for any interface with the given flags. Returns NULL if a device
1008  *	is not found or a pointer to the device. Must be called inside
1009  *	rtnl_lock(), and result refcount is unchanged.
1010  */
1011 
__dev_get_by_flags(struct net * net,unsigned short if_flags,unsigned short mask)1012 struct net_device *__dev_get_by_flags(struct net *net, unsigned short if_flags,
1013 				      unsigned short mask)
1014 {
1015 	struct net_device *dev, *ret;
1016 
1017 	ASSERT_RTNL();
1018 
1019 	ret = NULL;
1020 	for_each_netdev(net, dev) {
1021 		if (((dev->flags ^ if_flags) & mask) == 0) {
1022 			ret = dev;
1023 			break;
1024 		}
1025 	}
1026 	return ret;
1027 }
1028 EXPORT_SYMBOL(__dev_get_by_flags);
1029 
1030 /**
1031  *	dev_valid_name - check if name is okay for network device
1032  *	@name: name string
1033  *
1034  *	Network device names need to be valid file names to
1035  *	allow sysfs to work.  We also disallow any kind of
1036  *	whitespace.
1037  */
dev_valid_name(const char * name)1038 bool dev_valid_name(const char *name)
1039 {
1040 	if (*name == '\0')
1041 		return false;
1042 	if (strnlen(name, IFNAMSIZ) == IFNAMSIZ)
1043 		return false;
1044 	if (!strcmp(name, ".") || !strcmp(name, ".."))
1045 		return false;
1046 
1047 	while (*name) {
1048 		if (*name == '/' || *name == ':' || isspace(*name))
1049 			return false;
1050 		name++;
1051 	}
1052 	return true;
1053 }
1054 EXPORT_SYMBOL(dev_valid_name);
1055 
1056 /**
1057  *	__dev_alloc_name - allocate a name for a device
1058  *	@net: network namespace to allocate the device name in
1059  *	@name: name format string
1060  *	@buf:  scratch buffer and result name string
1061  *
1062  *	Passed a format string - eg "lt%d" it will try and find a suitable
1063  *	id. It scans list of devices to build up a free map, then chooses
1064  *	the first empty slot. The caller must hold the dev_base or rtnl lock
1065  *	while allocating the name and adding the device in order to avoid
1066  *	duplicates.
1067  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1068  *	Returns the number of the unit assigned or a negative errno code.
1069  */
1070 
__dev_alloc_name(struct net * net,const char * name,char * buf)1071 static int __dev_alloc_name(struct net *net, const char *name, char *buf)
1072 {
1073 	int i = 0;
1074 	const char *p;
1075 	const int max_netdevices = 8*PAGE_SIZE;
1076 	unsigned long *inuse;
1077 	struct net_device *d;
1078 
1079 	if (!dev_valid_name(name))
1080 		return -EINVAL;
1081 
1082 	p = strchr(name, '%');
1083 	if (p) {
1084 		/*
1085 		 * Verify the string as this thing may have come from
1086 		 * the user.  There must be either one "%d" and no other "%"
1087 		 * characters.
1088 		 */
1089 		if (p[1] != 'd' || strchr(p + 2, '%'))
1090 			return -EINVAL;
1091 
1092 		/* Use one page as a bit array of possible slots */
1093 		inuse = bitmap_zalloc(max_netdevices, GFP_ATOMIC);
1094 		if (!inuse)
1095 			return -ENOMEM;
1096 
1097 		for_each_netdev(net, d) {
1098 			struct netdev_name_node *name_node;
1099 
1100 			netdev_for_each_altname(d, name_node) {
1101 				if (!sscanf(name_node->name, name, &i))
1102 					continue;
1103 				if (i < 0 || i >= max_netdevices)
1104 					continue;
1105 
1106 				/*  avoid cases where sscanf is not exact inverse of printf */
1107 				snprintf(buf, IFNAMSIZ, name, i);
1108 				if (!strncmp(buf, name_node->name, IFNAMSIZ))
1109 					__set_bit(i, inuse);
1110 			}
1111 			if (!sscanf(d->name, name, &i))
1112 				continue;
1113 			if (i < 0 || i >= max_netdevices)
1114 				continue;
1115 
1116 			/*  avoid cases where sscanf is not exact inverse of printf */
1117 			snprintf(buf, IFNAMSIZ, name, i);
1118 			if (!strncmp(buf, d->name, IFNAMSIZ))
1119 				__set_bit(i, inuse);
1120 		}
1121 
1122 		i = find_first_zero_bit(inuse, max_netdevices);
1123 		bitmap_free(inuse);
1124 	}
1125 
1126 	snprintf(buf, IFNAMSIZ, name, i);
1127 	if (!netdev_name_in_use(net, buf))
1128 		return i;
1129 
1130 	/* It is possible to run out of possible slots
1131 	 * when the name is long and there isn't enough space left
1132 	 * for the digits, or if all bits are used.
1133 	 */
1134 	return -ENFILE;
1135 }
1136 
dev_prep_valid_name(struct net * net,struct net_device * dev,const char * want_name,char * out_name)1137 static int dev_prep_valid_name(struct net *net, struct net_device *dev,
1138 			       const char *want_name, char *out_name)
1139 {
1140 	int ret;
1141 
1142 	if (!dev_valid_name(want_name))
1143 		return -EINVAL;
1144 
1145 	if (strchr(want_name, '%')) {
1146 		ret = __dev_alloc_name(net, want_name, out_name);
1147 		return ret < 0 ? ret : 0;
1148 	} else if (netdev_name_in_use(net, want_name)) {
1149 		return -EEXIST;
1150 	} else if (out_name != want_name) {
1151 		strscpy(out_name, want_name, IFNAMSIZ);
1152 	}
1153 
1154 	return 0;
1155 }
1156 
dev_alloc_name_ns(struct net * net,struct net_device * dev,const char * name)1157 static int dev_alloc_name_ns(struct net *net,
1158 			     struct net_device *dev,
1159 			     const char *name)
1160 {
1161 	char buf[IFNAMSIZ];
1162 	int ret;
1163 
1164 	BUG_ON(!net);
1165 	ret = __dev_alloc_name(net, name, buf);
1166 	if (ret >= 0)
1167 		strscpy(dev->name, buf, IFNAMSIZ);
1168 	return ret;
1169 }
1170 
1171 /**
1172  *	dev_alloc_name - allocate a name for a device
1173  *	@dev: device
1174  *	@name: name format string
1175  *
1176  *	Passed a format string - eg "lt%d" it will try and find a suitable
1177  *	id. It scans list of devices to build up a free map, then chooses
1178  *	the first empty slot. The caller must hold the dev_base or rtnl lock
1179  *	while allocating the name and adding the device in order to avoid
1180  *	duplicates.
1181  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1182  *	Returns the number of the unit assigned or a negative errno code.
1183  */
1184 
dev_alloc_name(struct net_device * dev,const char * name)1185 int dev_alloc_name(struct net_device *dev, const char *name)
1186 {
1187 	return dev_alloc_name_ns(dev_net(dev), dev, name);
1188 }
1189 EXPORT_SYMBOL(dev_alloc_name);
1190 
dev_get_valid_name(struct net * net,struct net_device * dev,const char * name)1191 static int dev_get_valid_name(struct net *net, struct net_device *dev,
1192 			      const char *name)
1193 {
1194 	char buf[IFNAMSIZ];
1195 	int ret;
1196 
1197 	ret = dev_prep_valid_name(net, dev, name, buf);
1198 	if (ret >= 0)
1199 		strscpy(dev->name, buf, IFNAMSIZ);
1200 	return ret;
1201 }
1202 
1203 /**
1204  *	dev_change_name - change name of a device
1205  *	@dev: device
1206  *	@newname: name (or format string) must be at least IFNAMSIZ
1207  *
1208  *	Change name of a device, can pass format strings "eth%d".
1209  *	for wildcarding.
1210  */
dev_change_name(struct net_device * dev,const char * newname)1211 int dev_change_name(struct net_device *dev, const char *newname)
1212 {
1213 	unsigned char old_assign_type;
1214 	char oldname[IFNAMSIZ];
1215 	int err = 0;
1216 	int ret;
1217 	struct net *net;
1218 
1219 	ASSERT_RTNL();
1220 	BUG_ON(!dev_net(dev));
1221 
1222 	net = dev_net(dev);
1223 
1224 	down_write(&devnet_rename_sem);
1225 
1226 	if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
1227 		up_write(&devnet_rename_sem);
1228 		return 0;
1229 	}
1230 
1231 	memcpy(oldname, dev->name, IFNAMSIZ);
1232 
1233 	err = dev_get_valid_name(net, dev, newname);
1234 	if (err < 0) {
1235 		up_write(&devnet_rename_sem);
1236 		return err;
1237 	}
1238 
1239 	if (oldname[0] && !strchr(oldname, '%'))
1240 		netdev_info(dev, "renamed from %s%s\n", oldname,
1241 			    dev->flags & IFF_UP ? " (while UP)" : "");
1242 
1243 	old_assign_type = dev->name_assign_type;
1244 	dev->name_assign_type = NET_NAME_RENAMED;
1245 
1246 rollback:
1247 	ret = device_rename(&dev->dev, dev->name);
1248 	if (ret) {
1249 		memcpy(dev->name, oldname, IFNAMSIZ);
1250 		dev->name_assign_type = old_assign_type;
1251 		up_write(&devnet_rename_sem);
1252 		return ret;
1253 	}
1254 
1255 	up_write(&devnet_rename_sem);
1256 
1257 	netdev_adjacent_rename_links(dev, oldname);
1258 
1259 	write_lock(&dev_base_lock);
1260 	netdev_name_node_del(dev->name_node);
1261 	write_unlock(&dev_base_lock);
1262 
1263 	synchronize_rcu();
1264 
1265 	write_lock(&dev_base_lock);
1266 	netdev_name_node_add(net, dev->name_node);
1267 	write_unlock(&dev_base_lock);
1268 
1269 	ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1270 	ret = notifier_to_errno(ret);
1271 
1272 	if (ret) {
1273 		/* err >= 0 after dev_alloc_name() or stores the first errno */
1274 		if (err >= 0) {
1275 			err = ret;
1276 			down_write(&devnet_rename_sem);
1277 			memcpy(dev->name, oldname, IFNAMSIZ);
1278 			memcpy(oldname, newname, IFNAMSIZ);
1279 			dev->name_assign_type = old_assign_type;
1280 			old_assign_type = NET_NAME_RENAMED;
1281 			goto rollback;
1282 		} else {
1283 			netdev_err(dev, "name change rollback failed: %d\n",
1284 				   ret);
1285 		}
1286 	}
1287 
1288 	return err;
1289 }
1290 
1291 /**
1292  *	dev_set_alias - change ifalias of a device
1293  *	@dev: device
1294  *	@alias: name up to IFALIASZ
1295  *	@len: limit of bytes to copy from info
1296  *
1297  *	Set ifalias for a device,
1298  */
dev_set_alias(struct net_device * dev,const char * alias,size_t len)1299 int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
1300 {
1301 	struct dev_ifalias *new_alias = NULL;
1302 
1303 	if (len >= IFALIASZ)
1304 		return -EINVAL;
1305 
1306 	if (len) {
1307 		new_alias = kmalloc(sizeof(*new_alias) + len + 1, GFP_KERNEL);
1308 		if (!new_alias)
1309 			return -ENOMEM;
1310 
1311 		memcpy(new_alias->ifalias, alias, len);
1312 		new_alias->ifalias[len] = 0;
1313 	}
1314 
1315 	mutex_lock(&ifalias_mutex);
1316 	new_alias = rcu_replace_pointer(dev->ifalias, new_alias,
1317 					mutex_is_locked(&ifalias_mutex));
1318 	mutex_unlock(&ifalias_mutex);
1319 
1320 	if (new_alias)
1321 		kfree_rcu(new_alias, rcuhead);
1322 
1323 	return len;
1324 }
1325 EXPORT_SYMBOL(dev_set_alias);
1326 
1327 /**
1328  *	dev_get_alias - get ifalias of a device
1329  *	@dev: device
1330  *	@name: buffer to store name of ifalias
1331  *	@len: size of buffer
1332  *
1333  *	get ifalias for a device.  Caller must make sure dev cannot go
1334  *	away,  e.g. rcu read lock or own a reference count to device.
1335  */
dev_get_alias(const struct net_device * dev,char * name,size_t len)1336 int dev_get_alias(const struct net_device *dev, char *name, size_t len)
1337 {
1338 	const struct dev_ifalias *alias;
1339 	int ret = 0;
1340 
1341 	rcu_read_lock();
1342 	alias = rcu_dereference(dev->ifalias);
1343 	if (alias)
1344 		ret = snprintf(name, len, "%s", alias->ifalias);
1345 	rcu_read_unlock();
1346 
1347 	return ret;
1348 }
1349 
1350 /**
1351  *	netdev_features_change - device changes features
1352  *	@dev: device to cause notification
1353  *
1354  *	Called to indicate a device has changed features.
1355  */
netdev_features_change(struct net_device * dev)1356 void netdev_features_change(struct net_device *dev)
1357 {
1358 	call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1359 }
1360 EXPORT_SYMBOL(netdev_features_change);
1361 
1362 /**
1363  *	netdev_state_change - device changes state
1364  *	@dev: device to cause notification
1365  *
1366  *	Called to indicate a device has changed state. This function calls
1367  *	the notifier chains for netdev_chain and sends a NEWLINK message
1368  *	to the routing socket.
1369  */
netdev_state_change(struct net_device * dev)1370 void netdev_state_change(struct net_device *dev)
1371 {
1372 	if (dev->flags & IFF_UP) {
1373 		struct netdev_notifier_change_info change_info = {
1374 			.info.dev = dev,
1375 		};
1376 
1377 		call_netdevice_notifiers_info(NETDEV_CHANGE,
1378 					      &change_info.info);
1379 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL, 0, NULL);
1380 	}
1381 }
1382 EXPORT_SYMBOL(netdev_state_change);
1383 
1384 /**
1385  * __netdev_notify_peers - notify network peers about existence of @dev,
1386  * to be called when rtnl lock is already held.
1387  * @dev: network device
1388  *
1389  * Generate traffic such that interested network peers are aware of
1390  * @dev, such as by generating a gratuitous ARP. This may be used when
1391  * a device wants to inform the rest of the network about some sort of
1392  * reconfiguration such as a failover event or virtual machine
1393  * migration.
1394  */
__netdev_notify_peers(struct net_device * dev)1395 void __netdev_notify_peers(struct net_device *dev)
1396 {
1397 	ASSERT_RTNL();
1398 	call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
1399 	call_netdevice_notifiers(NETDEV_RESEND_IGMP, dev);
1400 }
1401 EXPORT_SYMBOL(__netdev_notify_peers);
1402 
1403 /**
1404  * netdev_notify_peers - notify network peers about existence of @dev
1405  * @dev: network device
1406  *
1407  * Generate traffic such that interested network peers are aware of
1408  * @dev, such as by generating a gratuitous ARP. This may be used when
1409  * a device wants to inform the rest of the network about some sort of
1410  * reconfiguration such as a failover event or virtual machine
1411  * migration.
1412  */
netdev_notify_peers(struct net_device * dev)1413 void netdev_notify_peers(struct net_device *dev)
1414 {
1415 	rtnl_lock();
1416 	__netdev_notify_peers(dev);
1417 	rtnl_unlock();
1418 }
1419 EXPORT_SYMBOL(netdev_notify_peers);
1420 
1421 static int napi_threaded_poll(void *data);
1422 
napi_kthread_create(struct napi_struct * n)1423 static int napi_kthread_create(struct napi_struct *n)
1424 {
1425 	int err = 0;
1426 
1427 	/* Create and wake up the kthread once to put it in
1428 	 * TASK_INTERRUPTIBLE mode to avoid the blocked task
1429 	 * warning and work with loadavg.
1430 	 */
1431 	n->thread = kthread_run(napi_threaded_poll, n, "napi/%s-%d",
1432 				n->dev->name, n->napi_id);
1433 	if (IS_ERR(n->thread)) {
1434 		err = PTR_ERR(n->thread);
1435 		pr_err("kthread_run failed with err %d\n", err);
1436 		n->thread = NULL;
1437 	}
1438 
1439 	return err;
1440 }
1441 
__dev_open(struct net_device * dev,struct netlink_ext_ack * extack)1442 static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1443 {
1444 	const struct net_device_ops *ops = dev->netdev_ops;
1445 	int ret;
1446 
1447 	ASSERT_RTNL();
1448 	dev_addr_check(dev);
1449 
1450 	if (!netif_device_present(dev)) {
1451 		/* may be detached because parent is runtime-suspended */
1452 		if (dev->dev.parent)
1453 			pm_runtime_resume(dev->dev.parent);
1454 		if (!netif_device_present(dev))
1455 			return -ENODEV;
1456 	}
1457 
1458 	/* Block netpoll from trying to do any rx path servicing.
1459 	 * If we don't do this there is a chance ndo_poll_controller
1460 	 * or ndo_poll may be running while we open the device
1461 	 */
1462 	netpoll_poll_disable(dev);
1463 
1464 	ret = call_netdevice_notifiers_extack(NETDEV_PRE_UP, dev, extack);
1465 	ret = notifier_to_errno(ret);
1466 	if (ret)
1467 		return ret;
1468 
1469 	set_bit(__LINK_STATE_START, &dev->state);
1470 
1471 	if (ops->ndo_validate_addr)
1472 		ret = ops->ndo_validate_addr(dev);
1473 
1474 	if (!ret && ops->ndo_open)
1475 		ret = ops->ndo_open(dev);
1476 
1477 	netpoll_poll_enable(dev);
1478 
1479 	if (ret)
1480 		clear_bit(__LINK_STATE_START, &dev->state);
1481 	else {
1482 		dev->flags |= IFF_UP;
1483 		dev_set_rx_mode(dev);
1484 		dev_activate(dev);
1485 		add_device_randomness(dev->dev_addr, dev->addr_len);
1486 	}
1487 
1488 	return ret;
1489 }
1490 
1491 /**
1492  *	dev_open	- prepare an interface for use.
1493  *	@dev: device to open
1494  *	@extack: netlink extended ack
1495  *
1496  *	Takes a device from down to up state. The device's private open
1497  *	function is invoked and then the multicast lists are loaded. Finally
1498  *	the device is moved into the up state and a %NETDEV_UP message is
1499  *	sent to the netdev notifier chain.
1500  *
1501  *	Calling this function on an active interface is a nop. On a failure
1502  *	a negative errno code is returned.
1503  */
dev_open(struct net_device * dev,struct netlink_ext_ack * extack)1504 int dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1505 {
1506 	int ret;
1507 
1508 	if (dev->flags & IFF_UP)
1509 		return 0;
1510 
1511 	ret = __dev_open(dev, extack);
1512 	if (ret < 0)
1513 		return ret;
1514 
1515 	rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP | IFF_RUNNING, GFP_KERNEL, 0, NULL);
1516 	call_netdevice_notifiers(NETDEV_UP, dev);
1517 
1518 	return ret;
1519 }
1520 EXPORT_SYMBOL(dev_open);
1521 
__dev_close_many(struct list_head * head)1522 static void __dev_close_many(struct list_head *head)
1523 {
1524 	struct net_device *dev;
1525 
1526 	ASSERT_RTNL();
1527 	might_sleep();
1528 
1529 	list_for_each_entry(dev, head, close_list) {
1530 		/* Temporarily disable netpoll until the interface is down */
1531 		netpoll_poll_disable(dev);
1532 
1533 		call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
1534 
1535 		clear_bit(__LINK_STATE_START, &dev->state);
1536 
1537 		/* Synchronize to scheduled poll. We cannot touch poll list, it
1538 		 * can be even on different cpu. So just clear netif_running().
1539 		 *
1540 		 * dev->stop() will invoke napi_disable() on all of it's
1541 		 * napi_struct instances on this device.
1542 		 */
1543 		smp_mb__after_atomic(); /* Commit netif_running(). */
1544 	}
1545 
1546 	dev_deactivate_many(head);
1547 
1548 	list_for_each_entry(dev, head, close_list) {
1549 		const struct net_device_ops *ops = dev->netdev_ops;
1550 
1551 		/*
1552 		 *	Call the device specific close. This cannot fail.
1553 		 *	Only if device is UP
1554 		 *
1555 		 *	We allow it to be called even after a DETACH hot-plug
1556 		 *	event.
1557 		 */
1558 		if (ops->ndo_stop)
1559 			ops->ndo_stop(dev);
1560 
1561 		dev->flags &= ~IFF_UP;
1562 		netpoll_poll_enable(dev);
1563 	}
1564 }
1565 
__dev_close(struct net_device * dev)1566 static void __dev_close(struct net_device *dev)
1567 {
1568 	LIST_HEAD(single);
1569 
1570 	list_add(&dev->close_list, &single);
1571 	__dev_close_many(&single);
1572 	list_del(&single);
1573 }
1574 
dev_close_many(struct list_head * head,bool unlink)1575 void dev_close_many(struct list_head *head, bool unlink)
1576 {
1577 	struct net_device *dev, *tmp;
1578 
1579 	/* Remove the devices that don't need to be closed */
1580 	list_for_each_entry_safe(dev, tmp, head, close_list)
1581 		if (!(dev->flags & IFF_UP))
1582 			list_del_init(&dev->close_list);
1583 
1584 	__dev_close_many(head);
1585 
1586 	list_for_each_entry_safe(dev, tmp, head, close_list) {
1587 		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP | IFF_RUNNING, GFP_KERNEL, 0, NULL);
1588 		call_netdevice_notifiers(NETDEV_DOWN, dev);
1589 		if (unlink)
1590 			list_del_init(&dev->close_list);
1591 	}
1592 }
1593 EXPORT_SYMBOL(dev_close_many);
1594 
1595 /**
1596  *	dev_close - shutdown an interface.
1597  *	@dev: device to shutdown
1598  *
1599  *	This function moves an active device into down state. A
1600  *	%NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
1601  *	is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
1602  *	chain.
1603  */
dev_close(struct net_device * dev)1604 void dev_close(struct net_device *dev)
1605 {
1606 	if (dev->flags & IFF_UP) {
1607 		LIST_HEAD(single);
1608 
1609 		list_add(&dev->close_list, &single);
1610 		dev_close_many(&single, true);
1611 		list_del(&single);
1612 	}
1613 }
1614 EXPORT_SYMBOL(dev_close);
1615 
1616 
1617 /**
1618  *	dev_disable_lro - disable Large Receive Offload on a device
1619  *	@dev: device
1620  *
1621  *	Disable Large Receive Offload (LRO) on a net device.  Must be
1622  *	called under RTNL.  This is needed if received packets may be
1623  *	forwarded to another interface.
1624  */
dev_disable_lro(struct net_device * dev)1625 void dev_disable_lro(struct net_device *dev)
1626 {
1627 	struct net_device *lower_dev;
1628 	struct list_head *iter;
1629 
1630 	dev->wanted_features &= ~NETIF_F_LRO;
1631 	netdev_update_features(dev);
1632 
1633 	if (unlikely(dev->features & NETIF_F_LRO))
1634 		netdev_WARN(dev, "failed to disable LRO!\n");
1635 
1636 	netdev_for_each_lower_dev(dev, lower_dev, iter)
1637 		dev_disable_lro(lower_dev);
1638 }
1639 EXPORT_SYMBOL(dev_disable_lro);
1640 
1641 /**
1642  *	dev_disable_gro_hw - disable HW Generic Receive Offload on a device
1643  *	@dev: device
1644  *
1645  *	Disable HW Generic Receive Offload (GRO_HW) on a net device.  Must be
1646  *	called under RTNL.  This is needed if Generic XDP is installed on
1647  *	the device.
1648  */
dev_disable_gro_hw(struct net_device * dev)1649 static void dev_disable_gro_hw(struct net_device *dev)
1650 {
1651 	dev->wanted_features &= ~NETIF_F_GRO_HW;
1652 	netdev_update_features(dev);
1653 
1654 	if (unlikely(dev->features & NETIF_F_GRO_HW))
1655 		netdev_WARN(dev, "failed to disable GRO_HW!\n");
1656 }
1657 
netdev_cmd_to_name(enum netdev_cmd cmd)1658 const char *netdev_cmd_to_name(enum netdev_cmd cmd)
1659 {
1660 #define N(val) 						\
1661 	case NETDEV_##val:				\
1662 		return "NETDEV_" __stringify(val);
1663 	switch (cmd) {
1664 	N(UP) N(DOWN) N(REBOOT) N(CHANGE) N(REGISTER) N(UNREGISTER)
1665 	N(CHANGEMTU) N(CHANGEADDR) N(GOING_DOWN) N(CHANGENAME) N(FEAT_CHANGE)
1666 	N(BONDING_FAILOVER) N(PRE_UP) N(PRE_TYPE_CHANGE) N(POST_TYPE_CHANGE)
1667 	N(POST_INIT) N(PRE_UNINIT) N(RELEASE) N(NOTIFY_PEERS) N(JOIN)
1668 	N(CHANGEUPPER) N(RESEND_IGMP) N(PRECHANGEMTU) N(CHANGEINFODATA)
1669 	N(BONDING_INFO) N(PRECHANGEUPPER) N(CHANGELOWERSTATE)
1670 	N(UDP_TUNNEL_PUSH_INFO) N(UDP_TUNNEL_DROP_INFO) N(CHANGE_TX_QUEUE_LEN)
1671 	N(CVLAN_FILTER_PUSH_INFO) N(CVLAN_FILTER_DROP_INFO)
1672 	N(SVLAN_FILTER_PUSH_INFO) N(SVLAN_FILTER_DROP_INFO)
1673 	N(PRE_CHANGEADDR) N(OFFLOAD_XSTATS_ENABLE) N(OFFLOAD_XSTATS_DISABLE)
1674 	N(OFFLOAD_XSTATS_REPORT_USED) N(OFFLOAD_XSTATS_REPORT_DELTA)
1675 	N(XDP_FEAT_CHANGE)
1676 	}
1677 #undef N
1678 	return "UNKNOWN_NETDEV_EVENT";
1679 }
1680 EXPORT_SYMBOL_GPL(netdev_cmd_to_name);
1681 
call_netdevice_notifier(struct notifier_block * nb,unsigned long val,struct net_device * dev)1682 static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val,
1683 				   struct net_device *dev)
1684 {
1685 	struct netdev_notifier_info info = {
1686 		.dev = dev,
1687 	};
1688 
1689 	return nb->notifier_call(nb, val, &info);
1690 }
1691 
call_netdevice_register_notifiers(struct notifier_block * nb,struct net_device * dev)1692 static int call_netdevice_register_notifiers(struct notifier_block *nb,
1693 					     struct net_device *dev)
1694 {
1695 	int err;
1696 
1697 	err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev);
1698 	err = notifier_to_errno(err);
1699 	if (err)
1700 		return err;
1701 
1702 	if (!(dev->flags & IFF_UP))
1703 		return 0;
1704 
1705 	call_netdevice_notifier(nb, NETDEV_UP, dev);
1706 	return 0;
1707 }
1708 
call_netdevice_unregister_notifiers(struct notifier_block * nb,struct net_device * dev)1709 static void call_netdevice_unregister_notifiers(struct notifier_block *nb,
1710 						struct net_device *dev)
1711 {
1712 	if (dev->flags & IFF_UP) {
1713 		call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
1714 					dev);
1715 		call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1716 	}
1717 	call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1718 }
1719 
call_netdevice_register_net_notifiers(struct notifier_block * nb,struct net * net)1720 static int call_netdevice_register_net_notifiers(struct notifier_block *nb,
1721 						 struct net *net)
1722 {
1723 	struct net_device *dev;
1724 	int err;
1725 
1726 	for_each_netdev(net, dev) {
1727 		err = call_netdevice_register_notifiers(nb, dev);
1728 		if (err)
1729 			goto rollback;
1730 	}
1731 	return 0;
1732 
1733 rollback:
1734 	for_each_netdev_continue_reverse(net, dev)
1735 		call_netdevice_unregister_notifiers(nb, dev);
1736 	return err;
1737 }
1738 
call_netdevice_unregister_net_notifiers(struct notifier_block * nb,struct net * net)1739 static void call_netdevice_unregister_net_notifiers(struct notifier_block *nb,
1740 						    struct net *net)
1741 {
1742 	struct net_device *dev;
1743 
1744 	for_each_netdev(net, dev)
1745 		call_netdevice_unregister_notifiers(nb, dev);
1746 }
1747 
1748 static int dev_boot_phase = 1;
1749 
1750 /**
1751  * register_netdevice_notifier - register a network notifier block
1752  * @nb: notifier
1753  *
1754  * Register a notifier to be called when network device events occur.
1755  * The notifier passed is linked into the kernel structures and must
1756  * not be reused until it has been unregistered. A negative errno code
1757  * is returned on a failure.
1758  *
1759  * When registered all registration and up events are replayed
1760  * to the new notifier to allow device to have a race free
1761  * view of the network device list.
1762  */
1763 
register_netdevice_notifier(struct notifier_block * nb)1764 int register_netdevice_notifier(struct notifier_block *nb)
1765 {
1766 	struct net *net;
1767 	int err;
1768 
1769 	/* Close race with setup_net() and cleanup_net() */
1770 	down_write(&pernet_ops_rwsem);
1771 	rtnl_lock();
1772 	err = raw_notifier_chain_register(&netdev_chain, nb);
1773 	if (err)
1774 		goto unlock;
1775 	if (dev_boot_phase)
1776 		goto unlock;
1777 	for_each_net(net) {
1778 		err = call_netdevice_register_net_notifiers(nb, net);
1779 		if (err)
1780 			goto rollback;
1781 	}
1782 
1783 unlock:
1784 	rtnl_unlock();
1785 	up_write(&pernet_ops_rwsem);
1786 	return err;
1787 
1788 rollback:
1789 	for_each_net_continue_reverse(net)
1790 		call_netdevice_unregister_net_notifiers(nb, net);
1791 
1792 	raw_notifier_chain_unregister(&netdev_chain, nb);
1793 	goto unlock;
1794 }
1795 EXPORT_SYMBOL(register_netdevice_notifier);
1796 
1797 /**
1798  * unregister_netdevice_notifier - unregister a network notifier block
1799  * @nb: notifier
1800  *
1801  * Unregister a notifier previously registered by
1802  * register_netdevice_notifier(). The notifier is unlinked into the
1803  * kernel structures and may then be reused. A negative errno code
1804  * is returned on a failure.
1805  *
1806  * After unregistering unregister and down device events are synthesized
1807  * for all devices on the device list to the removed notifier to remove
1808  * the need for special case cleanup code.
1809  */
1810 
unregister_netdevice_notifier(struct notifier_block * nb)1811 int unregister_netdevice_notifier(struct notifier_block *nb)
1812 {
1813 	struct net *net;
1814 	int err;
1815 
1816 	/* Close race with setup_net() and cleanup_net() */
1817 	down_write(&pernet_ops_rwsem);
1818 	rtnl_lock();
1819 	err = raw_notifier_chain_unregister(&netdev_chain, nb);
1820 	if (err)
1821 		goto unlock;
1822 
1823 	for_each_net(net)
1824 		call_netdevice_unregister_net_notifiers(nb, net);
1825 
1826 unlock:
1827 	rtnl_unlock();
1828 	up_write(&pernet_ops_rwsem);
1829 	return err;
1830 }
1831 EXPORT_SYMBOL(unregister_netdevice_notifier);
1832 
__register_netdevice_notifier_net(struct net * net,struct notifier_block * nb,bool ignore_call_fail)1833 static int __register_netdevice_notifier_net(struct net *net,
1834 					     struct notifier_block *nb,
1835 					     bool ignore_call_fail)
1836 {
1837 	int err;
1838 
1839 	err = raw_notifier_chain_register(&net->netdev_chain, nb);
1840 	if (err)
1841 		return err;
1842 	if (dev_boot_phase)
1843 		return 0;
1844 
1845 	err = call_netdevice_register_net_notifiers(nb, net);
1846 	if (err && !ignore_call_fail)
1847 		goto chain_unregister;
1848 
1849 	return 0;
1850 
1851 chain_unregister:
1852 	raw_notifier_chain_unregister(&net->netdev_chain, nb);
1853 	return err;
1854 }
1855 
__unregister_netdevice_notifier_net(struct net * net,struct notifier_block * nb)1856 static int __unregister_netdevice_notifier_net(struct net *net,
1857 					       struct notifier_block *nb)
1858 {
1859 	int err;
1860 
1861 	err = raw_notifier_chain_unregister(&net->netdev_chain, nb);
1862 	if (err)
1863 		return err;
1864 
1865 	call_netdevice_unregister_net_notifiers(nb, net);
1866 	return 0;
1867 }
1868 
1869 /**
1870  * register_netdevice_notifier_net - register a per-netns network notifier block
1871  * @net: network namespace
1872  * @nb: notifier
1873  *
1874  * Register a notifier to be called when network device events occur.
1875  * The notifier passed is linked into the kernel structures and must
1876  * not be reused until it has been unregistered. A negative errno code
1877  * is returned on a failure.
1878  *
1879  * When registered all registration and up events are replayed
1880  * to the new notifier to allow device to have a race free
1881  * view of the network device list.
1882  */
1883 
register_netdevice_notifier_net(struct net * net,struct notifier_block * nb)1884 int register_netdevice_notifier_net(struct net *net, struct notifier_block *nb)
1885 {
1886 	int err;
1887 
1888 	rtnl_lock();
1889 	err = __register_netdevice_notifier_net(net, nb, false);
1890 	rtnl_unlock();
1891 	return err;
1892 }
1893 EXPORT_SYMBOL(register_netdevice_notifier_net);
1894 
1895 /**
1896  * unregister_netdevice_notifier_net - unregister a per-netns
1897  *                                     network notifier block
1898  * @net: network namespace
1899  * @nb: notifier
1900  *
1901  * Unregister a notifier previously registered by
1902  * register_netdevice_notifier_net(). The notifier is unlinked from the
1903  * kernel structures and may then be reused. A negative errno code
1904  * is returned on a failure.
1905  *
1906  * After unregistering unregister and down device events are synthesized
1907  * for all devices on the device list to the removed notifier to remove
1908  * the need for special case cleanup code.
1909  */
1910 
unregister_netdevice_notifier_net(struct net * net,struct notifier_block * nb)1911 int unregister_netdevice_notifier_net(struct net *net,
1912 				      struct notifier_block *nb)
1913 {
1914 	int err;
1915 
1916 	rtnl_lock();
1917 	err = __unregister_netdevice_notifier_net(net, nb);
1918 	rtnl_unlock();
1919 	return err;
1920 }
1921 EXPORT_SYMBOL(unregister_netdevice_notifier_net);
1922 
__move_netdevice_notifier_net(struct net * src_net,struct net * dst_net,struct notifier_block * nb)1923 static void __move_netdevice_notifier_net(struct net *src_net,
1924 					  struct net *dst_net,
1925 					  struct notifier_block *nb)
1926 {
1927 	__unregister_netdevice_notifier_net(src_net, nb);
1928 	__register_netdevice_notifier_net(dst_net, nb, true);
1929 }
1930 
register_netdevice_notifier_dev_net(struct net_device * dev,struct notifier_block * nb,struct netdev_net_notifier * nn)1931 int register_netdevice_notifier_dev_net(struct net_device *dev,
1932 					struct notifier_block *nb,
1933 					struct netdev_net_notifier *nn)
1934 {
1935 	int err;
1936 
1937 	rtnl_lock();
1938 	err = __register_netdevice_notifier_net(dev_net(dev), nb, false);
1939 	if (!err) {
1940 		nn->nb = nb;
1941 		list_add(&nn->list, &dev->net_notifier_list);
1942 	}
1943 	rtnl_unlock();
1944 	return err;
1945 }
1946 EXPORT_SYMBOL(register_netdevice_notifier_dev_net);
1947 
unregister_netdevice_notifier_dev_net(struct net_device * dev,struct notifier_block * nb,struct netdev_net_notifier * nn)1948 int unregister_netdevice_notifier_dev_net(struct net_device *dev,
1949 					  struct notifier_block *nb,
1950 					  struct netdev_net_notifier *nn)
1951 {
1952 	int err;
1953 
1954 	rtnl_lock();
1955 	list_del(&nn->list);
1956 	err = __unregister_netdevice_notifier_net(dev_net(dev), nb);
1957 	rtnl_unlock();
1958 	return err;
1959 }
1960 EXPORT_SYMBOL(unregister_netdevice_notifier_dev_net);
1961 
move_netdevice_notifiers_dev_net(struct net_device * dev,struct net * net)1962 static void move_netdevice_notifiers_dev_net(struct net_device *dev,
1963 					     struct net *net)
1964 {
1965 	struct netdev_net_notifier *nn;
1966 
1967 	list_for_each_entry(nn, &dev->net_notifier_list, list)
1968 		__move_netdevice_notifier_net(dev_net(dev), net, nn->nb);
1969 }
1970 
1971 /**
1972  *	call_netdevice_notifiers_info - call all network notifier blocks
1973  *	@val: value passed unmodified to notifier function
1974  *	@info: notifier information data
1975  *
1976  *	Call all network notifier blocks.  Parameters and return value
1977  *	are as for raw_notifier_call_chain().
1978  */
1979 
call_netdevice_notifiers_info(unsigned long val,struct netdev_notifier_info * info)1980 int call_netdevice_notifiers_info(unsigned long val,
1981 				  struct netdev_notifier_info *info)
1982 {
1983 	struct net *net = dev_net(info->dev);
1984 	int ret;
1985 
1986 	ASSERT_RTNL();
1987 
1988 	/* Run per-netns notifier block chain first, then run the global one.
1989 	 * Hopefully, one day, the global one is going to be removed after
1990 	 * all notifier block registrators get converted to be per-netns.
1991 	 */
1992 	ret = raw_notifier_call_chain(&net->netdev_chain, val, info);
1993 	if (ret & NOTIFY_STOP_MASK)
1994 		return ret;
1995 	return raw_notifier_call_chain(&netdev_chain, val, info);
1996 }
1997 
1998 /**
1999  *	call_netdevice_notifiers_info_robust - call per-netns notifier blocks
2000  *	                                       for and rollback on error
2001  *	@val_up: value passed unmodified to notifier function
2002  *	@val_down: value passed unmodified to the notifier function when
2003  *	           recovering from an error on @val_up
2004  *	@info: notifier information data
2005  *
2006  *	Call all per-netns network notifier blocks, but not notifier blocks on
2007  *	the global notifier chain. Parameters and return value are as for
2008  *	raw_notifier_call_chain_robust().
2009  */
2010 
2011 static int
call_netdevice_notifiers_info_robust(unsigned long val_up,unsigned long val_down,struct netdev_notifier_info * info)2012 call_netdevice_notifiers_info_robust(unsigned long val_up,
2013 				     unsigned long val_down,
2014 				     struct netdev_notifier_info *info)
2015 {
2016 	struct net *net = dev_net(info->dev);
2017 
2018 	ASSERT_RTNL();
2019 
2020 	return raw_notifier_call_chain_robust(&net->netdev_chain,
2021 					      val_up, val_down, info);
2022 }
2023 
call_netdevice_notifiers_extack(unsigned long val,struct net_device * dev,struct netlink_ext_ack * extack)2024 static int call_netdevice_notifiers_extack(unsigned long val,
2025 					   struct net_device *dev,
2026 					   struct netlink_ext_ack *extack)
2027 {
2028 	struct netdev_notifier_info info = {
2029 		.dev = dev,
2030 		.extack = extack,
2031 	};
2032 
2033 	return call_netdevice_notifiers_info(val, &info);
2034 }
2035 
2036 /**
2037  *	call_netdevice_notifiers - call all network notifier blocks
2038  *      @val: value passed unmodified to notifier function
2039  *      @dev: net_device pointer passed unmodified to notifier function
2040  *
2041  *	Call all network notifier blocks.  Parameters and return value
2042  *	are as for raw_notifier_call_chain().
2043  */
2044 
call_netdevice_notifiers(unsigned long val,struct net_device * dev)2045 int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
2046 {
2047 	return call_netdevice_notifiers_extack(val, dev, NULL);
2048 }
2049 EXPORT_SYMBOL(call_netdevice_notifiers);
2050 
2051 /**
2052  *	call_netdevice_notifiers_mtu - call all network notifier blocks
2053  *	@val: value passed unmodified to notifier function
2054  *	@dev: net_device pointer passed unmodified to notifier function
2055  *	@arg: additional u32 argument passed to the notifier function
2056  *
2057  *	Call all network notifier blocks.  Parameters and return value
2058  *	are as for raw_notifier_call_chain().
2059  */
call_netdevice_notifiers_mtu(unsigned long val,struct net_device * dev,u32 arg)2060 static int call_netdevice_notifiers_mtu(unsigned long val,
2061 					struct net_device *dev, u32 arg)
2062 {
2063 	struct netdev_notifier_info_ext info = {
2064 		.info.dev = dev,
2065 		.ext.mtu = arg,
2066 	};
2067 
2068 	BUILD_BUG_ON(offsetof(struct netdev_notifier_info_ext, info) != 0);
2069 
2070 	return call_netdevice_notifiers_info(val, &info.info);
2071 }
2072 
2073 #ifdef CONFIG_NET_INGRESS
2074 static DEFINE_STATIC_KEY_FALSE(ingress_needed_key);
2075 
net_inc_ingress_queue(void)2076 void net_inc_ingress_queue(void)
2077 {
2078 	static_branch_inc(&ingress_needed_key);
2079 }
2080 EXPORT_SYMBOL_GPL(net_inc_ingress_queue);
2081 
net_dec_ingress_queue(void)2082 void net_dec_ingress_queue(void)
2083 {
2084 	static_branch_dec(&ingress_needed_key);
2085 }
2086 EXPORT_SYMBOL_GPL(net_dec_ingress_queue);
2087 #endif
2088 
2089 #ifdef CONFIG_NET_EGRESS
2090 static DEFINE_STATIC_KEY_FALSE(egress_needed_key);
2091 
net_inc_egress_queue(void)2092 void net_inc_egress_queue(void)
2093 {
2094 	static_branch_inc(&egress_needed_key);
2095 }
2096 EXPORT_SYMBOL_GPL(net_inc_egress_queue);
2097 
net_dec_egress_queue(void)2098 void net_dec_egress_queue(void)
2099 {
2100 	static_branch_dec(&egress_needed_key);
2101 }
2102 EXPORT_SYMBOL_GPL(net_dec_egress_queue);
2103 #endif
2104 
2105 DEFINE_STATIC_KEY_FALSE(netstamp_needed_key);
2106 EXPORT_SYMBOL(netstamp_needed_key);
2107 #ifdef CONFIG_JUMP_LABEL
2108 static atomic_t netstamp_needed_deferred;
2109 static atomic_t netstamp_wanted;
netstamp_clear(struct work_struct * work)2110 static void netstamp_clear(struct work_struct *work)
2111 {
2112 	int deferred = atomic_xchg(&netstamp_needed_deferred, 0);
2113 	int wanted;
2114 
2115 	wanted = atomic_add_return(deferred, &netstamp_wanted);
2116 	if (wanted > 0)
2117 		static_branch_enable(&netstamp_needed_key);
2118 	else
2119 		static_branch_disable(&netstamp_needed_key);
2120 }
2121 static DECLARE_WORK(netstamp_work, netstamp_clear);
2122 #endif
2123 
net_enable_timestamp(void)2124 void net_enable_timestamp(void)
2125 {
2126 #ifdef CONFIG_JUMP_LABEL
2127 	int wanted = atomic_read(&netstamp_wanted);
2128 
2129 	while (wanted > 0) {
2130 		if (atomic_try_cmpxchg(&netstamp_wanted, &wanted, wanted + 1))
2131 			return;
2132 	}
2133 	atomic_inc(&netstamp_needed_deferred);
2134 	schedule_work(&netstamp_work);
2135 #else
2136 	static_branch_inc(&netstamp_needed_key);
2137 #endif
2138 }
2139 EXPORT_SYMBOL(net_enable_timestamp);
2140 
net_disable_timestamp(void)2141 void net_disable_timestamp(void)
2142 {
2143 #ifdef CONFIG_JUMP_LABEL
2144 	int wanted = atomic_read(&netstamp_wanted);
2145 
2146 	while (wanted > 1) {
2147 		if (atomic_try_cmpxchg(&netstamp_wanted, &wanted, wanted - 1))
2148 			return;
2149 	}
2150 	atomic_dec(&netstamp_needed_deferred);
2151 	schedule_work(&netstamp_work);
2152 #else
2153 	static_branch_dec(&netstamp_needed_key);
2154 #endif
2155 }
2156 EXPORT_SYMBOL(net_disable_timestamp);
2157 
net_timestamp_set(struct sk_buff * skb)2158 static inline void net_timestamp_set(struct sk_buff *skb)
2159 {
2160 	skb->tstamp = 0;
2161 	skb->mono_delivery_time = 0;
2162 	if (static_branch_unlikely(&netstamp_needed_key))
2163 		skb->tstamp = ktime_get_real();
2164 }
2165 
2166 #define net_timestamp_check(COND, SKB)				\
2167 	if (static_branch_unlikely(&netstamp_needed_key)) {	\
2168 		if ((COND) && !(SKB)->tstamp)			\
2169 			(SKB)->tstamp = ktime_get_real();	\
2170 	}							\
2171 
is_skb_forwardable(const struct net_device * dev,const struct sk_buff * skb)2172 bool is_skb_forwardable(const struct net_device *dev, const struct sk_buff *skb)
2173 {
2174 	return __is_skb_forwardable(dev, skb, true);
2175 }
2176 EXPORT_SYMBOL_GPL(is_skb_forwardable);
2177 
__dev_forward_skb2(struct net_device * dev,struct sk_buff * skb,bool check_mtu)2178 static int __dev_forward_skb2(struct net_device *dev, struct sk_buff *skb,
2179 			      bool check_mtu)
2180 {
2181 	int ret = ____dev_forward_skb(dev, skb, check_mtu);
2182 
2183 	if (likely(!ret)) {
2184 		skb->protocol = eth_type_trans(skb, dev);
2185 		skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
2186 	}
2187 
2188 	return ret;
2189 }
2190 
__dev_forward_skb(struct net_device * dev,struct sk_buff * skb)2191 int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2192 {
2193 	return __dev_forward_skb2(dev, skb, true);
2194 }
2195 EXPORT_SYMBOL_GPL(__dev_forward_skb);
2196 
2197 /**
2198  * dev_forward_skb - loopback an skb to another netif
2199  *
2200  * @dev: destination network device
2201  * @skb: buffer to forward
2202  *
2203  * return values:
2204  *	NET_RX_SUCCESS	(no congestion)
2205  *	NET_RX_DROP     (packet was dropped, but freed)
2206  *
2207  * dev_forward_skb can be used for injecting an skb from the
2208  * start_xmit function of one device into the receive queue
2209  * of another device.
2210  *
2211  * The receiving device may be in another namespace, so
2212  * we have to clear all information in the skb that could
2213  * impact namespace isolation.
2214  */
dev_forward_skb(struct net_device * dev,struct sk_buff * skb)2215 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2216 {
2217 	return __dev_forward_skb(dev, skb) ?: netif_rx_internal(skb);
2218 }
2219 EXPORT_SYMBOL_GPL(dev_forward_skb);
2220 
dev_forward_skb_nomtu(struct net_device * dev,struct sk_buff * skb)2221 int dev_forward_skb_nomtu(struct net_device *dev, struct sk_buff *skb)
2222 {
2223 	return __dev_forward_skb2(dev, skb, false) ?: netif_rx_internal(skb);
2224 }
2225 
deliver_skb(struct sk_buff * skb,struct packet_type * pt_prev,struct net_device * orig_dev)2226 static inline int deliver_skb(struct sk_buff *skb,
2227 			      struct packet_type *pt_prev,
2228 			      struct net_device *orig_dev)
2229 {
2230 	if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
2231 		return -ENOMEM;
2232 	refcount_inc(&skb->users);
2233 	return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
2234 }
2235 
deliver_ptype_list_skb(struct sk_buff * skb,struct packet_type ** pt,struct net_device * orig_dev,__be16 type,struct list_head * ptype_list)2236 static inline void deliver_ptype_list_skb(struct sk_buff *skb,
2237 					  struct packet_type **pt,
2238 					  struct net_device *orig_dev,
2239 					  __be16 type,
2240 					  struct list_head *ptype_list)
2241 {
2242 	struct packet_type *ptype, *pt_prev = *pt;
2243 
2244 	list_for_each_entry_rcu(ptype, ptype_list, list) {
2245 		if (ptype->type != type)
2246 			continue;
2247 		if (pt_prev)
2248 			deliver_skb(skb, pt_prev, orig_dev);
2249 		pt_prev = ptype;
2250 	}
2251 	*pt = pt_prev;
2252 }
2253 
skb_loop_sk(struct packet_type * ptype,struct sk_buff * skb)2254 static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
2255 {
2256 	if (!ptype->af_packet_priv || !skb->sk)
2257 		return false;
2258 
2259 	if (ptype->id_match)
2260 		return ptype->id_match(ptype, skb->sk);
2261 	else if ((struct sock *)ptype->af_packet_priv == skb->sk)
2262 		return true;
2263 
2264 	return false;
2265 }
2266 
2267 /**
2268  * dev_nit_active - return true if any network interface taps are in use
2269  *
2270  * @dev: network device to check for the presence of taps
2271  */
dev_nit_active(struct net_device * dev)2272 bool dev_nit_active(struct net_device *dev)
2273 {
2274 	return !list_empty(&ptype_all) || !list_empty(&dev->ptype_all);
2275 }
2276 EXPORT_SYMBOL_GPL(dev_nit_active);
2277 
2278 /*
2279  *	Support routine. Sends outgoing frames to any network
2280  *	taps currently in use.
2281  */
2282 
dev_queue_xmit_nit(struct sk_buff * skb,struct net_device * dev)2283 void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
2284 {
2285 	struct packet_type *ptype;
2286 	struct sk_buff *skb2 = NULL;
2287 	struct packet_type *pt_prev = NULL;
2288 	struct list_head *ptype_list = &ptype_all;
2289 
2290 	rcu_read_lock();
2291 again:
2292 	list_for_each_entry_rcu(ptype, ptype_list, list) {
2293 		if (ptype->ignore_outgoing)
2294 			continue;
2295 
2296 		/* Never send packets back to the socket
2297 		 * they originated from - MvS (miquels@drinkel.ow.org)
2298 		 */
2299 		if (skb_loop_sk(ptype, skb))
2300 			continue;
2301 
2302 		if (pt_prev) {
2303 			deliver_skb(skb2, pt_prev, skb->dev);
2304 			pt_prev = ptype;
2305 			continue;
2306 		}
2307 
2308 		/* need to clone skb, done only once */
2309 		skb2 = skb_clone(skb, GFP_ATOMIC);
2310 		if (!skb2)
2311 			goto out_unlock;
2312 
2313 		net_timestamp_set(skb2);
2314 
2315 		/* skb->nh should be correctly
2316 		 * set by sender, so that the second statement is
2317 		 * just protection against buggy protocols.
2318 		 */
2319 		skb_reset_mac_header(skb2);
2320 
2321 		if (skb_network_header(skb2) < skb2->data ||
2322 		    skb_network_header(skb2) > skb_tail_pointer(skb2)) {
2323 			net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
2324 					     ntohs(skb2->protocol),
2325 					     dev->name);
2326 			skb_reset_network_header(skb2);
2327 		}
2328 
2329 		skb2->transport_header = skb2->network_header;
2330 		skb2->pkt_type = PACKET_OUTGOING;
2331 		pt_prev = ptype;
2332 	}
2333 
2334 	if (ptype_list == &ptype_all) {
2335 		ptype_list = &dev->ptype_all;
2336 		goto again;
2337 	}
2338 out_unlock:
2339 	if (pt_prev) {
2340 		if (!skb_orphan_frags_rx(skb2, GFP_ATOMIC))
2341 			pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
2342 		else
2343 			kfree_skb(skb2);
2344 	}
2345 	rcu_read_unlock();
2346 }
2347 EXPORT_SYMBOL_GPL(dev_queue_xmit_nit);
2348 
2349 /**
2350  * netif_setup_tc - Handle tc mappings on real_num_tx_queues change
2351  * @dev: Network device
2352  * @txq: number of queues available
2353  *
2354  * If real_num_tx_queues is changed the tc mappings may no longer be
2355  * valid. To resolve this verify the tc mapping remains valid and if
2356  * not NULL the mapping. With no priorities mapping to this
2357  * offset/count pair it will no longer be used. In the worst case TC0
2358  * is invalid nothing can be done so disable priority mappings. If is
2359  * expected that drivers will fix this mapping if they can before
2360  * calling netif_set_real_num_tx_queues.
2361  */
netif_setup_tc(struct net_device * dev,unsigned int txq)2362 static void netif_setup_tc(struct net_device *dev, unsigned int txq)
2363 {
2364 	int i;
2365 	struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2366 
2367 	/* If TC0 is invalidated disable TC mapping */
2368 	if (tc->offset + tc->count > txq) {
2369 		netdev_warn(dev, "Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
2370 		dev->num_tc = 0;
2371 		return;
2372 	}
2373 
2374 	/* Invalidated prio to tc mappings set to TC0 */
2375 	for (i = 1; i < TC_BITMASK + 1; i++) {
2376 		int q = netdev_get_prio_tc_map(dev, i);
2377 
2378 		tc = &dev->tc_to_txq[q];
2379 		if (tc->offset + tc->count > txq) {
2380 			netdev_warn(dev, "Number of in use tx queues changed. Priority %i to tc mapping %i is no longer valid. Setting map to 0\n",
2381 				    i, q);
2382 			netdev_set_prio_tc_map(dev, i, 0);
2383 		}
2384 	}
2385 }
2386 
netdev_txq_to_tc(struct net_device * dev,unsigned int txq)2387 int netdev_txq_to_tc(struct net_device *dev, unsigned int txq)
2388 {
2389 	if (dev->num_tc) {
2390 		struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2391 		int i;
2392 
2393 		/* walk through the TCs and see if it falls into any of them */
2394 		for (i = 0; i < TC_MAX_QUEUE; i++, tc++) {
2395 			if ((txq - tc->offset) < tc->count)
2396 				return i;
2397 		}
2398 
2399 		/* didn't find it, just return -1 to indicate no match */
2400 		return -1;
2401 	}
2402 
2403 	return 0;
2404 }
2405 EXPORT_SYMBOL(netdev_txq_to_tc);
2406 
2407 #ifdef CONFIG_XPS
2408 static struct static_key xps_needed __read_mostly;
2409 static struct static_key xps_rxqs_needed __read_mostly;
2410 static DEFINE_MUTEX(xps_map_mutex);
2411 #define xmap_dereference(P)		\
2412 	rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
2413 
remove_xps_queue(struct xps_dev_maps * dev_maps,struct xps_dev_maps * old_maps,int tci,u16 index)2414 static bool remove_xps_queue(struct xps_dev_maps *dev_maps,
2415 			     struct xps_dev_maps *old_maps, int tci, u16 index)
2416 {
2417 	struct xps_map *map = NULL;
2418 	int pos;
2419 
2420 	map = xmap_dereference(dev_maps->attr_map[tci]);
2421 	if (!map)
2422 		return false;
2423 
2424 	for (pos = map->len; pos--;) {
2425 		if (map->queues[pos] != index)
2426 			continue;
2427 
2428 		if (map->len > 1) {
2429 			map->queues[pos] = map->queues[--map->len];
2430 			break;
2431 		}
2432 
2433 		if (old_maps)
2434 			RCU_INIT_POINTER(old_maps->attr_map[tci], NULL);
2435 		RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2436 		kfree_rcu(map, rcu);
2437 		return false;
2438 	}
2439 
2440 	return true;
2441 }
2442 
remove_xps_queue_cpu(struct net_device * dev,struct xps_dev_maps * dev_maps,int cpu,u16 offset,u16 count)2443 static bool remove_xps_queue_cpu(struct net_device *dev,
2444 				 struct xps_dev_maps *dev_maps,
2445 				 int cpu, u16 offset, u16 count)
2446 {
2447 	int num_tc = dev_maps->num_tc;
2448 	bool active = false;
2449 	int tci;
2450 
2451 	for (tci = cpu * num_tc; num_tc--; tci++) {
2452 		int i, j;
2453 
2454 		for (i = count, j = offset; i--; j++) {
2455 			if (!remove_xps_queue(dev_maps, NULL, tci, j))
2456 				break;
2457 		}
2458 
2459 		active |= i < 0;
2460 	}
2461 
2462 	return active;
2463 }
2464 
reset_xps_maps(struct net_device * dev,struct xps_dev_maps * dev_maps,enum xps_map_type type)2465 static void reset_xps_maps(struct net_device *dev,
2466 			   struct xps_dev_maps *dev_maps,
2467 			   enum xps_map_type type)
2468 {
2469 	static_key_slow_dec_cpuslocked(&xps_needed);
2470 	if (type == XPS_RXQS)
2471 		static_key_slow_dec_cpuslocked(&xps_rxqs_needed);
2472 
2473 	RCU_INIT_POINTER(dev->xps_maps[type], NULL);
2474 
2475 	kfree_rcu(dev_maps, rcu);
2476 }
2477 
clean_xps_maps(struct net_device * dev,enum xps_map_type type,u16 offset,u16 count)2478 static void clean_xps_maps(struct net_device *dev, enum xps_map_type type,
2479 			   u16 offset, u16 count)
2480 {
2481 	struct xps_dev_maps *dev_maps;
2482 	bool active = false;
2483 	int i, j;
2484 
2485 	dev_maps = xmap_dereference(dev->xps_maps[type]);
2486 	if (!dev_maps)
2487 		return;
2488 
2489 	for (j = 0; j < dev_maps->nr_ids; j++)
2490 		active |= remove_xps_queue_cpu(dev, dev_maps, j, offset, count);
2491 	if (!active)
2492 		reset_xps_maps(dev, dev_maps, type);
2493 
2494 	if (type == XPS_CPUS) {
2495 		for (i = offset + (count - 1); count--; i--)
2496 			netdev_queue_numa_node_write(
2497 				netdev_get_tx_queue(dev, i), NUMA_NO_NODE);
2498 	}
2499 }
2500 
netif_reset_xps_queues(struct net_device * dev,u16 offset,u16 count)2501 static void netif_reset_xps_queues(struct net_device *dev, u16 offset,
2502 				   u16 count)
2503 {
2504 	if (!static_key_false(&xps_needed))
2505 		return;
2506 
2507 	cpus_read_lock();
2508 	mutex_lock(&xps_map_mutex);
2509 
2510 	if (static_key_false(&xps_rxqs_needed))
2511 		clean_xps_maps(dev, XPS_RXQS, offset, count);
2512 
2513 	clean_xps_maps(dev, XPS_CPUS, offset, count);
2514 
2515 	mutex_unlock(&xps_map_mutex);
2516 	cpus_read_unlock();
2517 }
2518 
netif_reset_xps_queues_gt(struct net_device * dev,u16 index)2519 static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
2520 {
2521 	netif_reset_xps_queues(dev, index, dev->num_tx_queues - index);
2522 }
2523 
expand_xps_map(struct xps_map * map,int attr_index,u16 index,bool is_rxqs_map)2524 static struct xps_map *expand_xps_map(struct xps_map *map, int attr_index,
2525 				      u16 index, bool is_rxqs_map)
2526 {
2527 	struct xps_map *new_map;
2528 	int alloc_len = XPS_MIN_MAP_ALLOC;
2529 	int i, pos;
2530 
2531 	for (pos = 0; map && pos < map->len; pos++) {
2532 		if (map->queues[pos] != index)
2533 			continue;
2534 		return map;
2535 	}
2536 
2537 	/* Need to add tx-queue to this CPU's/rx-queue's existing map */
2538 	if (map) {
2539 		if (pos < map->alloc_len)
2540 			return map;
2541 
2542 		alloc_len = map->alloc_len * 2;
2543 	}
2544 
2545 	/* Need to allocate new map to store tx-queue on this CPU's/rx-queue's
2546 	 *  map
2547 	 */
2548 	if (is_rxqs_map)
2549 		new_map = kzalloc(XPS_MAP_SIZE(alloc_len), GFP_KERNEL);
2550 	else
2551 		new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len), GFP_KERNEL,
2552 				       cpu_to_node(attr_index));
2553 	if (!new_map)
2554 		return NULL;
2555 
2556 	for (i = 0; i < pos; i++)
2557 		new_map->queues[i] = map->queues[i];
2558 	new_map->alloc_len = alloc_len;
2559 	new_map->len = pos;
2560 
2561 	return new_map;
2562 }
2563 
2564 /* Copy xps maps at a given index */
xps_copy_dev_maps(struct xps_dev_maps * dev_maps,struct xps_dev_maps * new_dev_maps,int index,int tc,bool skip_tc)2565 static void xps_copy_dev_maps(struct xps_dev_maps *dev_maps,
2566 			      struct xps_dev_maps *new_dev_maps, int index,
2567 			      int tc, bool skip_tc)
2568 {
2569 	int i, tci = index * dev_maps->num_tc;
2570 	struct xps_map *map;
2571 
2572 	/* copy maps belonging to foreign traffic classes */
2573 	for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2574 		if (i == tc && skip_tc)
2575 			continue;
2576 
2577 		/* fill in the new device map from the old device map */
2578 		map = xmap_dereference(dev_maps->attr_map[tci]);
2579 		RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2580 	}
2581 }
2582 
2583 /* Must be called under cpus_read_lock */
__netif_set_xps_queue(struct net_device * dev,const unsigned long * mask,u16 index,enum xps_map_type type)2584 int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask,
2585 			  u16 index, enum xps_map_type type)
2586 {
2587 	struct xps_dev_maps *dev_maps, *new_dev_maps = NULL, *old_dev_maps = NULL;
2588 	const unsigned long *online_mask = NULL;
2589 	bool active = false, copy = false;
2590 	int i, j, tci, numa_node_id = -2;
2591 	int maps_sz, num_tc = 1, tc = 0;
2592 	struct xps_map *map, *new_map;
2593 	unsigned int nr_ids;
2594 
2595 	WARN_ON_ONCE(index >= dev->num_tx_queues);
2596 
2597 	if (dev->num_tc) {
2598 		/* Do not allow XPS on subordinate device directly */
2599 		num_tc = dev->num_tc;
2600 		if (num_tc < 0)
2601 			return -EINVAL;
2602 
2603 		/* If queue belongs to subordinate dev use its map */
2604 		dev = netdev_get_tx_queue(dev, index)->sb_dev ? : dev;
2605 
2606 		tc = netdev_txq_to_tc(dev, index);
2607 		if (tc < 0)
2608 			return -EINVAL;
2609 	}
2610 
2611 	mutex_lock(&xps_map_mutex);
2612 
2613 	dev_maps = xmap_dereference(dev->xps_maps[type]);
2614 	if (type == XPS_RXQS) {
2615 		maps_sz = XPS_RXQ_DEV_MAPS_SIZE(num_tc, dev->num_rx_queues);
2616 		nr_ids = dev->num_rx_queues;
2617 	} else {
2618 		maps_sz = XPS_CPU_DEV_MAPS_SIZE(num_tc);
2619 		if (num_possible_cpus() > 1)
2620 			online_mask = cpumask_bits(cpu_online_mask);
2621 		nr_ids = nr_cpu_ids;
2622 	}
2623 
2624 	if (maps_sz < L1_CACHE_BYTES)
2625 		maps_sz = L1_CACHE_BYTES;
2626 
2627 	/* The old dev_maps could be larger or smaller than the one we're
2628 	 * setting up now, as dev->num_tc or nr_ids could have been updated in
2629 	 * between. We could try to be smart, but let's be safe instead and only
2630 	 * copy foreign traffic classes if the two map sizes match.
2631 	 */
2632 	if (dev_maps &&
2633 	    dev_maps->num_tc == num_tc && dev_maps->nr_ids == nr_ids)
2634 		copy = true;
2635 
2636 	/* allocate memory for queue storage */
2637 	for (j = -1; j = netif_attrmask_next_and(j, online_mask, mask, nr_ids),
2638 	     j < nr_ids;) {
2639 		if (!new_dev_maps) {
2640 			new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
2641 			if (!new_dev_maps) {
2642 				mutex_unlock(&xps_map_mutex);
2643 				return -ENOMEM;
2644 			}
2645 
2646 			new_dev_maps->nr_ids = nr_ids;
2647 			new_dev_maps->num_tc = num_tc;
2648 		}
2649 
2650 		tci = j * num_tc + tc;
2651 		map = copy ? xmap_dereference(dev_maps->attr_map[tci]) : NULL;
2652 
2653 		map = expand_xps_map(map, j, index, type == XPS_RXQS);
2654 		if (!map)
2655 			goto error;
2656 
2657 		RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2658 	}
2659 
2660 	if (!new_dev_maps)
2661 		goto out_no_new_maps;
2662 
2663 	if (!dev_maps) {
2664 		/* Increment static keys at most once per type */
2665 		static_key_slow_inc_cpuslocked(&xps_needed);
2666 		if (type == XPS_RXQS)
2667 			static_key_slow_inc_cpuslocked(&xps_rxqs_needed);
2668 	}
2669 
2670 	for (j = 0; j < nr_ids; j++) {
2671 		bool skip_tc = false;
2672 
2673 		tci = j * num_tc + tc;
2674 		if (netif_attr_test_mask(j, mask, nr_ids) &&
2675 		    netif_attr_test_online(j, online_mask, nr_ids)) {
2676 			/* add tx-queue to CPU/rx-queue maps */
2677 			int pos = 0;
2678 
2679 			skip_tc = true;
2680 
2681 			map = xmap_dereference(new_dev_maps->attr_map[tci]);
2682 			while ((pos < map->len) && (map->queues[pos] != index))
2683 				pos++;
2684 
2685 			if (pos == map->len)
2686 				map->queues[map->len++] = index;
2687 #ifdef CONFIG_NUMA
2688 			if (type == XPS_CPUS) {
2689 				if (numa_node_id == -2)
2690 					numa_node_id = cpu_to_node(j);
2691 				else if (numa_node_id != cpu_to_node(j))
2692 					numa_node_id = -1;
2693 			}
2694 #endif
2695 		}
2696 
2697 		if (copy)
2698 			xps_copy_dev_maps(dev_maps, new_dev_maps, j, tc,
2699 					  skip_tc);
2700 	}
2701 
2702 	rcu_assign_pointer(dev->xps_maps[type], new_dev_maps);
2703 
2704 	/* Cleanup old maps */
2705 	if (!dev_maps)
2706 		goto out_no_old_maps;
2707 
2708 	for (j = 0; j < dev_maps->nr_ids; j++) {
2709 		for (i = num_tc, tci = j * dev_maps->num_tc; i--; tci++) {
2710 			map = xmap_dereference(dev_maps->attr_map[tci]);
2711 			if (!map)
2712 				continue;
2713 
2714 			if (copy) {
2715 				new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2716 				if (map == new_map)
2717 					continue;
2718 			}
2719 
2720 			RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2721 			kfree_rcu(map, rcu);
2722 		}
2723 	}
2724 
2725 	old_dev_maps = dev_maps;
2726 
2727 out_no_old_maps:
2728 	dev_maps = new_dev_maps;
2729 	active = true;
2730 
2731 out_no_new_maps:
2732 	if (type == XPS_CPUS)
2733 		/* update Tx queue numa node */
2734 		netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
2735 					     (numa_node_id >= 0) ?
2736 					     numa_node_id : NUMA_NO_NODE);
2737 
2738 	if (!dev_maps)
2739 		goto out_no_maps;
2740 
2741 	/* removes tx-queue from unused CPUs/rx-queues */
2742 	for (j = 0; j < dev_maps->nr_ids; j++) {
2743 		tci = j * dev_maps->num_tc;
2744 
2745 		for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2746 			if (i == tc &&
2747 			    netif_attr_test_mask(j, mask, dev_maps->nr_ids) &&
2748 			    netif_attr_test_online(j, online_mask, dev_maps->nr_ids))
2749 				continue;
2750 
2751 			active |= remove_xps_queue(dev_maps,
2752 						   copy ? old_dev_maps : NULL,
2753 						   tci, index);
2754 		}
2755 	}
2756 
2757 	if (old_dev_maps)
2758 		kfree_rcu(old_dev_maps, rcu);
2759 
2760 	/* free map if not active */
2761 	if (!active)
2762 		reset_xps_maps(dev, dev_maps, type);
2763 
2764 out_no_maps:
2765 	mutex_unlock(&xps_map_mutex);
2766 
2767 	return 0;
2768 error:
2769 	/* remove any maps that we added */
2770 	for (j = 0; j < nr_ids; j++) {
2771 		for (i = num_tc, tci = j * num_tc; i--; tci++) {
2772 			new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2773 			map = copy ?
2774 			      xmap_dereference(dev_maps->attr_map[tci]) :
2775 			      NULL;
2776 			if (new_map && new_map != map)
2777 				kfree(new_map);
2778 		}
2779 	}
2780 
2781 	mutex_unlock(&xps_map_mutex);
2782 
2783 	kfree(new_dev_maps);
2784 	return -ENOMEM;
2785 }
2786 EXPORT_SYMBOL_GPL(__netif_set_xps_queue);
2787 
netif_set_xps_queue(struct net_device * dev,const struct cpumask * mask,u16 index)2788 int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask,
2789 			u16 index)
2790 {
2791 	int ret;
2792 
2793 	cpus_read_lock();
2794 	ret =  __netif_set_xps_queue(dev, cpumask_bits(mask), index, XPS_CPUS);
2795 	cpus_read_unlock();
2796 
2797 	return ret;
2798 }
2799 EXPORT_SYMBOL(netif_set_xps_queue);
2800 
2801 #endif
netdev_unbind_all_sb_channels(struct net_device * dev)2802 static void netdev_unbind_all_sb_channels(struct net_device *dev)
2803 {
2804 	struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2805 
2806 	/* Unbind any subordinate channels */
2807 	while (txq-- != &dev->_tx[0]) {
2808 		if (txq->sb_dev)
2809 			netdev_unbind_sb_channel(dev, txq->sb_dev);
2810 	}
2811 }
2812 
netdev_reset_tc(struct net_device * dev)2813 void netdev_reset_tc(struct net_device *dev)
2814 {
2815 #ifdef CONFIG_XPS
2816 	netif_reset_xps_queues_gt(dev, 0);
2817 #endif
2818 	netdev_unbind_all_sb_channels(dev);
2819 
2820 	/* Reset TC configuration of device */
2821 	dev->num_tc = 0;
2822 	memset(dev->tc_to_txq, 0, sizeof(dev->tc_to_txq));
2823 	memset(dev->prio_tc_map, 0, sizeof(dev->prio_tc_map));
2824 }
2825 EXPORT_SYMBOL(netdev_reset_tc);
2826 
netdev_set_tc_queue(struct net_device * dev,u8 tc,u16 count,u16 offset)2827 int netdev_set_tc_queue(struct net_device *dev, u8 tc, u16 count, u16 offset)
2828 {
2829 	if (tc >= dev->num_tc)
2830 		return -EINVAL;
2831 
2832 #ifdef CONFIG_XPS
2833 	netif_reset_xps_queues(dev, offset, count);
2834 #endif
2835 	dev->tc_to_txq[tc].count = count;
2836 	dev->tc_to_txq[tc].offset = offset;
2837 	return 0;
2838 }
2839 EXPORT_SYMBOL(netdev_set_tc_queue);
2840 
netdev_set_num_tc(struct net_device * dev,u8 num_tc)2841 int netdev_set_num_tc(struct net_device *dev, u8 num_tc)
2842 {
2843 	if (num_tc > TC_MAX_QUEUE)
2844 		return -EINVAL;
2845 
2846 #ifdef CONFIG_XPS
2847 	netif_reset_xps_queues_gt(dev, 0);
2848 #endif
2849 	netdev_unbind_all_sb_channels(dev);
2850 
2851 	dev->num_tc = num_tc;
2852 	return 0;
2853 }
2854 EXPORT_SYMBOL(netdev_set_num_tc);
2855 
netdev_unbind_sb_channel(struct net_device * dev,struct net_device * sb_dev)2856 void netdev_unbind_sb_channel(struct net_device *dev,
2857 			      struct net_device *sb_dev)
2858 {
2859 	struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2860 
2861 #ifdef CONFIG_XPS
2862 	netif_reset_xps_queues_gt(sb_dev, 0);
2863 #endif
2864 	memset(sb_dev->tc_to_txq, 0, sizeof(sb_dev->tc_to_txq));
2865 	memset(sb_dev->prio_tc_map, 0, sizeof(sb_dev->prio_tc_map));
2866 
2867 	while (txq-- != &dev->_tx[0]) {
2868 		if (txq->sb_dev == sb_dev)
2869 			txq->sb_dev = NULL;
2870 	}
2871 }
2872 EXPORT_SYMBOL(netdev_unbind_sb_channel);
2873 
netdev_bind_sb_channel_queue(struct net_device * dev,struct net_device * sb_dev,u8 tc,u16 count,u16 offset)2874 int netdev_bind_sb_channel_queue(struct net_device *dev,
2875 				 struct net_device *sb_dev,
2876 				 u8 tc, u16 count, u16 offset)
2877 {
2878 	/* Make certain the sb_dev and dev are already configured */
2879 	if (sb_dev->num_tc >= 0 || tc >= dev->num_tc)
2880 		return -EINVAL;
2881 
2882 	/* We cannot hand out queues we don't have */
2883 	if ((offset + count) > dev->real_num_tx_queues)
2884 		return -EINVAL;
2885 
2886 	/* Record the mapping */
2887 	sb_dev->tc_to_txq[tc].count = count;
2888 	sb_dev->tc_to_txq[tc].offset = offset;
2889 
2890 	/* Provide a way for Tx queue to find the tc_to_txq map or
2891 	 * XPS map for itself.
2892 	 */
2893 	while (count--)
2894 		netdev_get_tx_queue(dev, count + offset)->sb_dev = sb_dev;
2895 
2896 	return 0;
2897 }
2898 EXPORT_SYMBOL(netdev_bind_sb_channel_queue);
2899 
netdev_set_sb_channel(struct net_device * dev,u16 channel)2900 int netdev_set_sb_channel(struct net_device *dev, u16 channel)
2901 {
2902 	/* Do not use a multiqueue device to represent a subordinate channel */
2903 	if (netif_is_multiqueue(dev))
2904 		return -ENODEV;
2905 
2906 	/* We allow channels 1 - 32767 to be used for subordinate channels.
2907 	 * Channel 0 is meant to be "native" mode and used only to represent
2908 	 * the main root device. We allow writing 0 to reset the device back
2909 	 * to normal mode after being used as a subordinate channel.
2910 	 */
2911 	if (channel > S16_MAX)
2912 		return -EINVAL;
2913 
2914 	dev->num_tc = -channel;
2915 
2916 	return 0;
2917 }
2918 EXPORT_SYMBOL(netdev_set_sb_channel);
2919 
2920 /*
2921  * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
2922  * greater than real_num_tx_queues stale skbs on the qdisc must be flushed.
2923  */
netif_set_real_num_tx_queues(struct net_device * dev,unsigned int txq)2924 int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
2925 {
2926 	bool disabling;
2927 	int rc;
2928 
2929 	disabling = txq < dev->real_num_tx_queues;
2930 
2931 	if (txq < 1 || txq > dev->num_tx_queues)
2932 		return -EINVAL;
2933 
2934 	if (dev->reg_state == NETREG_REGISTERED ||
2935 	    dev->reg_state == NETREG_UNREGISTERING) {
2936 		ASSERT_RTNL();
2937 
2938 		rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
2939 						  txq);
2940 		if (rc)
2941 			return rc;
2942 
2943 		if (dev->num_tc)
2944 			netif_setup_tc(dev, txq);
2945 
2946 		dev_qdisc_change_real_num_tx(dev, txq);
2947 
2948 		dev->real_num_tx_queues = txq;
2949 
2950 		if (disabling) {
2951 			synchronize_net();
2952 			qdisc_reset_all_tx_gt(dev, txq);
2953 #ifdef CONFIG_XPS
2954 			netif_reset_xps_queues_gt(dev, txq);
2955 #endif
2956 		}
2957 	} else {
2958 		dev->real_num_tx_queues = txq;
2959 	}
2960 
2961 	return 0;
2962 }
2963 EXPORT_SYMBOL(netif_set_real_num_tx_queues);
2964 
2965 #ifdef CONFIG_SYSFS
2966 /**
2967  *	netif_set_real_num_rx_queues - set actual number of RX queues used
2968  *	@dev: Network device
2969  *	@rxq: Actual number of RX queues
2970  *
2971  *	This must be called either with the rtnl_lock held or before
2972  *	registration of the net device.  Returns 0 on success, or a
2973  *	negative error code.  If called before registration, it always
2974  *	succeeds.
2975  */
netif_set_real_num_rx_queues(struct net_device * dev,unsigned int rxq)2976 int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
2977 {
2978 	int rc;
2979 
2980 	if (rxq < 1 || rxq > dev->num_rx_queues)
2981 		return -EINVAL;
2982 
2983 	if (dev->reg_state == NETREG_REGISTERED) {
2984 		ASSERT_RTNL();
2985 
2986 		rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
2987 						  rxq);
2988 		if (rc)
2989 			return rc;
2990 	}
2991 
2992 	dev->real_num_rx_queues = rxq;
2993 	return 0;
2994 }
2995 EXPORT_SYMBOL(netif_set_real_num_rx_queues);
2996 #endif
2997 
2998 /**
2999  *	netif_set_real_num_queues - set actual number of RX and TX queues used
3000  *	@dev: Network device
3001  *	@txq: Actual number of TX queues
3002  *	@rxq: Actual number of RX queues
3003  *
3004  *	Set the real number of both TX and RX queues.
3005  *	Does nothing if the number of queues is already correct.
3006  */
netif_set_real_num_queues(struct net_device * dev,unsigned int txq,unsigned int rxq)3007 int netif_set_real_num_queues(struct net_device *dev,
3008 			      unsigned int txq, unsigned int rxq)
3009 {
3010 	unsigned int old_rxq = dev->real_num_rx_queues;
3011 	int err;
3012 
3013 	if (txq < 1 || txq > dev->num_tx_queues ||
3014 	    rxq < 1 || rxq > dev->num_rx_queues)
3015 		return -EINVAL;
3016 
3017 	/* Start from increases, so the error path only does decreases -
3018 	 * decreases can't fail.
3019 	 */
3020 	if (rxq > dev->real_num_rx_queues) {
3021 		err = netif_set_real_num_rx_queues(dev, rxq);
3022 		if (err)
3023 			return err;
3024 	}
3025 	if (txq > dev->real_num_tx_queues) {
3026 		err = netif_set_real_num_tx_queues(dev, txq);
3027 		if (err)
3028 			goto undo_rx;
3029 	}
3030 	if (rxq < dev->real_num_rx_queues)
3031 		WARN_ON(netif_set_real_num_rx_queues(dev, rxq));
3032 	if (txq < dev->real_num_tx_queues)
3033 		WARN_ON(netif_set_real_num_tx_queues(dev, txq));
3034 
3035 	return 0;
3036 undo_rx:
3037 	WARN_ON(netif_set_real_num_rx_queues(dev, old_rxq));
3038 	return err;
3039 }
3040 EXPORT_SYMBOL(netif_set_real_num_queues);
3041 
3042 /**
3043  * netif_set_tso_max_size() - set the max size of TSO frames supported
3044  * @dev:	netdev to update
3045  * @size:	max skb->len of a TSO frame
3046  *
3047  * Set the limit on the size of TSO super-frames the device can handle.
3048  * Unless explicitly set the stack will assume the value of
3049  * %GSO_LEGACY_MAX_SIZE.
3050  */
netif_set_tso_max_size(struct net_device * dev,unsigned int size)3051 void netif_set_tso_max_size(struct net_device *dev, unsigned int size)
3052 {
3053 	dev->tso_max_size = min(GSO_MAX_SIZE, size);
3054 	if (size < READ_ONCE(dev->gso_max_size))
3055 		netif_set_gso_max_size(dev, size);
3056 	if (size < READ_ONCE(dev->gso_ipv4_max_size))
3057 		netif_set_gso_ipv4_max_size(dev, size);
3058 }
3059 EXPORT_SYMBOL(netif_set_tso_max_size);
3060 
3061 /**
3062  * netif_set_tso_max_segs() - set the max number of segs supported for TSO
3063  * @dev:	netdev to update
3064  * @segs:	max number of TCP segments
3065  *
3066  * Set the limit on the number of TCP segments the device can generate from
3067  * a single TSO super-frame.
3068  * Unless explicitly set the stack will assume the value of %GSO_MAX_SEGS.
3069  */
netif_set_tso_max_segs(struct net_device * dev,unsigned int segs)3070 void netif_set_tso_max_segs(struct net_device *dev, unsigned int segs)
3071 {
3072 	dev->tso_max_segs = segs;
3073 	if (segs < READ_ONCE(dev->gso_max_segs))
3074 		netif_set_gso_max_segs(dev, segs);
3075 }
3076 EXPORT_SYMBOL(netif_set_tso_max_segs);
3077 
3078 /**
3079  * netif_inherit_tso_max() - copy all TSO limits from a lower device to an upper
3080  * @to:		netdev to update
3081  * @from:	netdev from which to copy the limits
3082  */
netif_inherit_tso_max(struct net_device * to,const struct net_device * from)3083 void netif_inherit_tso_max(struct net_device *to, const struct net_device *from)
3084 {
3085 	netif_set_tso_max_size(to, from->tso_max_size);
3086 	netif_set_tso_max_segs(to, from->tso_max_segs);
3087 }
3088 EXPORT_SYMBOL(netif_inherit_tso_max);
3089 
3090 /**
3091  * netif_get_num_default_rss_queues - default number of RSS queues
3092  *
3093  * Default value is the number of physical cores if there are only 1 or 2, or
3094  * divided by 2 if there are more.
3095  */
netif_get_num_default_rss_queues(void)3096 int netif_get_num_default_rss_queues(void)
3097 {
3098 	cpumask_var_t cpus;
3099 	int cpu, count = 0;
3100 
3101 	if (unlikely(is_kdump_kernel() || !zalloc_cpumask_var(&cpus, GFP_KERNEL)))
3102 		return 1;
3103 
3104 	cpumask_copy(cpus, cpu_online_mask);
3105 	for_each_cpu(cpu, cpus) {
3106 		++count;
3107 		cpumask_andnot(cpus, cpus, topology_sibling_cpumask(cpu));
3108 	}
3109 	free_cpumask_var(cpus);
3110 
3111 	return count > 2 ? DIV_ROUND_UP(count, 2) : count;
3112 }
3113 EXPORT_SYMBOL(netif_get_num_default_rss_queues);
3114 
__netif_reschedule(struct Qdisc * q)3115 static void __netif_reschedule(struct Qdisc *q)
3116 {
3117 	struct softnet_data *sd;
3118 	unsigned long flags;
3119 
3120 	local_irq_save(flags);
3121 	sd = this_cpu_ptr(&softnet_data);
3122 	q->next_sched = NULL;
3123 	*sd->output_queue_tailp = q;
3124 	sd->output_queue_tailp = &q->next_sched;
3125 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
3126 	local_irq_restore(flags);
3127 }
3128 
__netif_schedule(struct Qdisc * q)3129 void __netif_schedule(struct Qdisc *q)
3130 {
3131 	if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
3132 		__netif_reschedule(q);
3133 }
3134 EXPORT_SYMBOL(__netif_schedule);
3135 
3136 struct dev_kfree_skb_cb {
3137 	enum skb_drop_reason reason;
3138 };
3139 
get_kfree_skb_cb(const struct sk_buff * skb)3140 static struct dev_kfree_skb_cb *get_kfree_skb_cb(const struct sk_buff *skb)
3141 {
3142 	return (struct dev_kfree_skb_cb *)skb->cb;
3143 }
3144 
netif_schedule_queue(struct netdev_queue * txq)3145 void netif_schedule_queue(struct netdev_queue *txq)
3146 {
3147 	rcu_read_lock();
3148 	if (!netif_xmit_stopped(txq)) {
3149 		struct Qdisc *q = rcu_dereference(txq->qdisc);
3150 
3151 		__netif_schedule(q);
3152 	}
3153 	rcu_read_unlock();
3154 }
3155 EXPORT_SYMBOL(netif_schedule_queue);
3156 
netif_tx_wake_queue(struct netdev_queue * dev_queue)3157 void netif_tx_wake_queue(struct netdev_queue *dev_queue)
3158 {
3159 	if (test_and_clear_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state)) {
3160 		struct Qdisc *q;
3161 
3162 		rcu_read_lock();
3163 		q = rcu_dereference(dev_queue->qdisc);
3164 		__netif_schedule(q);
3165 		rcu_read_unlock();
3166 	}
3167 }
3168 EXPORT_SYMBOL(netif_tx_wake_queue);
3169 
dev_kfree_skb_irq_reason(struct sk_buff * skb,enum skb_drop_reason reason)3170 void dev_kfree_skb_irq_reason(struct sk_buff *skb, enum skb_drop_reason reason)
3171 {
3172 	unsigned long flags;
3173 
3174 	if (unlikely(!skb))
3175 		return;
3176 
3177 	if (likely(refcount_read(&skb->users) == 1)) {
3178 		smp_rmb();
3179 		refcount_set(&skb->users, 0);
3180 	} else if (likely(!refcount_dec_and_test(&skb->users))) {
3181 		return;
3182 	}
3183 	get_kfree_skb_cb(skb)->reason = reason;
3184 	local_irq_save(flags);
3185 	skb->next = __this_cpu_read(softnet_data.completion_queue);
3186 	__this_cpu_write(softnet_data.completion_queue, skb);
3187 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
3188 	local_irq_restore(flags);
3189 }
3190 EXPORT_SYMBOL(dev_kfree_skb_irq_reason);
3191 
dev_kfree_skb_any_reason(struct sk_buff * skb,enum skb_drop_reason reason)3192 void dev_kfree_skb_any_reason(struct sk_buff *skb, enum skb_drop_reason reason)
3193 {
3194 	if (in_hardirq() || irqs_disabled())
3195 		dev_kfree_skb_irq_reason(skb, reason);
3196 	else
3197 		kfree_skb_reason(skb, reason);
3198 }
3199 EXPORT_SYMBOL(dev_kfree_skb_any_reason);
3200 
3201 
3202 /**
3203  * netif_device_detach - mark device as removed
3204  * @dev: network device
3205  *
3206  * Mark device as removed from system and therefore no longer available.
3207  */
netif_device_detach(struct net_device * dev)3208 void netif_device_detach(struct net_device *dev)
3209 {
3210 	if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
3211 	    netif_running(dev)) {
3212 		netif_tx_stop_all_queues(dev);
3213 	}
3214 }
3215 EXPORT_SYMBOL(netif_device_detach);
3216 
3217 /**
3218  * netif_device_attach - mark device as attached
3219  * @dev: network device
3220  *
3221  * Mark device as attached from system and restart if needed.
3222  */
netif_device_attach(struct net_device * dev)3223 void netif_device_attach(struct net_device *dev)
3224 {
3225 	if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
3226 	    netif_running(dev)) {
3227 		netif_tx_wake_all_queues(dev);
3228 		__netdev_watchdog_up(dev);
3229 	}
3230 }
3231 EXPORT_SYMBOL(netif_device_attach);
3232 
3233 /*
3234  * Returns a Tx hash based on the given packet descriptor a Tx queues' number
3235  * to be used as a distribution range.
3236  */
skb_tx_hash(const struct net_device * dev,const struct net_device * sb_dev,struct sk_buff * skb)3237 static u16 skb_tx_hash(const struct net_device *dev,
3238 		       const struct net_device *sb_dev,
3239 		       struct sk_buff *skb)
3240 {
3241 	u32 hash;
3242 	u16 qoffset = 0;
3243 	u16 qcount = dev->real_num_tx_queues;
3244 
3245 	if (dev->num_tc) {
3246 		u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
3247 
3248 		qoffset = sb_dev->tc_to_txq[tc].offset;
3249 		qcount = sb_dev->tc_to_txq[tc].count;
3250 		if (unlikely(!qcount)) {
3251 			net_warn_ratelimited("%s: invalid qcount, qoffset %u for tc %u\n",
3252 					     sb_dev->name, qoffset, tc);
3253 			qoffset = 0;
3254 			qcount = dev->real_num_tx_queues;
3255 		}
3256 	}
3257 
3258 	if (skb_rx_queue_recorded(skb)) {
3259 		DEBUG_NET_WARN_ON_ONCE(qcount == 0);
3260 		hash = skb_get_rx_queue(skb);
3261 		if (hash >= qoffset)
3262 			hash -= qoffset;
3263 		while (unlikely(hash >= qcount))
3264 			hash -= qcount;
3265 		return hash + qoffset;
3266 	}
3267 
3268 	return (u16) reciprocal_scale(skb_get_hash(skb), qcount) + qoffset;
3269 }
3270 
skb_warn_bad_offload(const struct sk_buff * skb)3271 void skb_warn_bad_offload(const struct sk_buff *skb)
3272 {
3273 	static const netdev_features_t null_features;
3274 	struct net_device *dev = skb->dev;
3275 	const char *name = "";
3276 
3277 	if (!net_ratelimit())
3278 		return;
3279 
3280 	if (dev) {
3281 		if (dev->dev.parent)
3282 			name = dev_driver_string(dev->dev.parent);
3283 		else
3284 			name = netdev_name(dev);
3285 	}
3286 	skb_dump(KERN_WARNING, skb, false);
3287 	WARN(1, "%s: caps=(%pNF, %pNF)\n",
3288 	     name, dev ? &dev->features : &null_features,
3289 	     skb->sk ? &skb->sk->sk_route_caps : &null_features);
3290 }
3291 
3292 /*
3293  * Invalidate hardware checksum when packet is to be mangled, and
3294  * complete checksum manually on outgoing path.
3295  */
skb_checksum_help(struct sk_buff * skb)3296 int skb_checksum_help(struct sk_buff *skb)
3297 {
3298 	__wsum csum;
3299 	int ret = 0, offset;
3300 
3301 	if (skb->ip_summed == CHECKSUM_COMPLETE)
3302 		goto out_set_summed;
3303 
3304 	if (unlikely(skb_is_gso(skb))) {
3305 		skb_warn_bad_offload(skb);
3306 		return -EINVAL;
3307 	}
3308 
3309 	/* Before computing a checksum, we should make sure no frag could
3310 	 * be modified by an external entity : checksum could be wrong.
3311 	 */
3312 	if (skb_has_shared_frag(skb)) {
3313 		ret = __skb_linearize(skb);
3314 		if (ret)
3315 			goto out;
3316 	}
3317 
3318 	offset = skb_checksum_start_offset(skb);
3319 	ret = -EINVAL;
3320 	if (unlikely(offset >= skb_headlen(skb))) {
3321 		DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
3322 		WARN_ONCE(true, "offset (%d) >= skb_headlen() (%u)\n",
3323 			  offset, skb_headlen(skb));
3324 		goto out;
3325 	}
3326 	csum = skb_checksum(skb, offset, skb->len - offset, 0);
3327 
3328 	offset += skb->csum_offset;
3329 	if (unlikely(offset + sizeof(__sum16) > skb_headlen(skb))) {
3330 		DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
3331 		WARN_ONCE(true, "offset+2 (%zu) > skb_headlen() (%u)\n",
3332 			  offset + sizeof(__sum16), skb_headlen(skb));
3333 		goto out;
3334 	}
3335 	ret = skb_ensure_writable(skb, offset + sizeof(__sum16));
3336 	if (ret)
3337 		goto out;
3338 
3339 	*(__sum16 *)(skb->data + offset) = csum_fold(csum) ?: CSUM_MANGLED_0;
3340 out_set_summed:
3341 	skb->ip_summed = CHECKSUM_NONE;
3342 out:
3343 	return ret;
3344 }
3345 EXPORT_SYMBOL(skb_checksum_help);
3346 
skb_crc32c_csum_help(struct sk_buff * skb)3347 int skb_crc32c_csum_help(struct sk_buff *skb)
3348 {
3349 	__le32 crc32c_csum;
3350 	int ret = 0, offset, start;
3351 
3352 	if (skb->ip_summed != CHECKSUM_PARTIAL)
3353 		goto out;
3354 
3355 	if (unlikely(skb_is_gso(skb)))
3356 		goto out;
3357 
3358 	/* Before computing a checksum, we should make sure no frag could
3359 	 * be modified by an external entity : checksum could be wrong.
3360 	 */
3361 	if (unlikely(skb_has_shared_frag(skb))) {
3362 		ret = __skb_linearize(skb);
3363 		if (ret)
3364 			goto out;
3365 	}
3366 	start = skb_checksum_start_offset(skb);
3367 	offset = start + offsetof(struct sctphdr, checksum);
3368 	if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
3369 		ret = -EINVAL;
3370 		goto out;
3371 	}
3372 
3373 	ret = skb_ensure_writable(skb, offset + sizeof(__le32));
3374 	if (ret)
3375 		goto out;
3376 
3377 	crc32c_csum = cpu_to_le32(~__skb_checksum(skb, start,
3378 						  skb->len - start, ~(__u32)0,
3379 						  crc32c_csum_stub));
3380 	*(__le32 *)(skb->data + offset) = crc32c_csum;
3381 	skb_reset_csum_not_inet(skb);
3382 out:
3383 	return ret;
3384 }
3385 
skb_network_protocol(struct sk_buff * skb,int * depth)3386 __be16 skb_network_protocol(struct sk_buff *skb, int *depth)
3387 {
3388 	__be16 type = skb->protocol;
3389 
3390 	/* Tunnel gso handlers can set protocol to ethernet. */
3391 	if (type == htons(ETH_P_TEB)) {
3392 		struct ethhdr *eth;
3393 
3394 		if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
3395 			return 0;
3396 
3397 		eth = (struct ethhdr *)skb->data;
3398 		type = eth->h_proto;
3399 	}
3400 
3401 	return vlan_get_protocol_and_depth(skb, type, depth);
3402 }
3403 
3404 
3405 /* Take action when hardware reception checksum errors are detected. */
3406 #ifdef CONFIG_BUG
do_netdev_rx_csum_fault(struct net_device * dev,struct sk_buff * skb)3407 static void do_netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3408 {
3409 	netdev_err(dev, "hw csum failure\n");
3410 	skb_dump(KERN_ERR, skb, true);
3411 	dump_stack();
3412 }
3413 
netdev_rx_csum_fault(struct net_device * dev,struct sk_buff * skb)3414 void netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3415 {
3416 	DO_ONCE_LITE(do_netdev_rx_csum_fault, dev, skb);
3417 }
3418 EXPORT_SYMBOL(netdev_rx_csum_fault);
3419 #endif
3420 
3421 /* XXX: check that highmem exists at all on the given machine. */
illegal_highdma(struct net_device * dev,struct sk_buff * skb)3422 static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
3423 {
3424 #ifdef CONFIG_HIGHMEM
3425 	int i;
3426 
3427 	if (!(dev->features & NETIF_F_HIGHDMA)) {
3428 		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
3429 			skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
3430 
3431 			if (PageHighMem(skb_frag_page(frag)))
3432 				return 1;
3433 		}
3434 	}
3435 #endif
3436 	return 0;
3437 }
3438 
3439 /* If MPLS offload request, verify we are testing hardware MPLS features
3440  * instead of standard features for the netdev.
3441  */
3442 #if IS_ENABLED(CONFIG_NET_MPLS_GSO)
net_mpls_features(struct sk_buff * skb,netdev_features_t features,__be16 type)3443 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3444 					   netdev_features_t features,
3445 					   __be16 type)
3446 {
3447 	if (eth_p_mpls(type))
3448 		features &= skb->dev->mpls_features;
3449 
3450 	return features;
3451 }
3452 #else
net_mpls_features(struct sk_buff * skb,netdev_features_t features,__be16 type)3453 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3454 					   netdev_features_t features,
3455 					   __be16 type)
3456 {
3457 	return features;
3458 }
3459 #endif
3460 
harmonize_features(struct sk_buff * skb,netdev_features_t features)3461 static netdev_features_t harmonize_features(struct sk_buff *skb,
3462 	netdev_features_t features)
3463 {
3464 	__be16 type;
3465 
3466 	type = skb_network_protocol(skb, NULL);
3467 	features = net_mpls_features(skb, features, type);
3468 
3469 	if (skb->ip_summed != CHECKSUM_NONE &&
3470 	    !can_checksum_protocol(features, type)) {
3471 		features &= ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
3472 	}
3473 	if (illegal_highdma(skb->dev, skb))
3474 		features &= ~NETIF_F_SG;
3475 
3476 	return features;
3477 }
3478 
passthru_features_check(struct sk_buff * skb,struct net_device * dev,netdev_features_t features)3479 netdev_features_t passthru_features_check(struct sk_buff *skb,
3480 					  struct net_device *dev,
3481 					  netdev_features_t features)
3482 {
3483 	return features;
3484 }
3485 EXPORT_SYMBOL(passthru_features_check);
3486 
dflt_features_check(struct sk_buff * skb,struct net_device * dev,netdev_features_t features)3487 static netdev_features_t dflt_features_check(struct sk_buff *skb,
3488 					     struct net_device *dev,
3489 					     netdev_features_t features)
3490 {
3491 	return vlan_features_check(skb, features);
3492 }
3493 
gso_features_check(const struct sk_buff * skb,struct net_device * dev,netdev_features_t features)3494 static netdev_features_t gso_features_check(const struct sk_buff *skb,
3495 					    struct net_device *dev,
3496 					    netdev_features_t features)
3497 {
3498 	u16 gso_segs = skb_shinfo(skb)->gso_segs;
3499 
3500 	if (gso_segs > READ_ONCE(dev->gso_max_segs))
3501 		return features & ~NETIF_F_GSO_MASK;
3502 
3503 	if (unlikely(skb->len >= READ_ONCE(dev->gso_max_size)))
3504 		return features & ~NETIF_F_GSO_MASK;
3505 
3506 	if (!skb_shinfo(skb)->gso_type) {
3507 		skb_warn_bad_offload(skb);
3508 		return features & ~NETIF_F_GSO_MASK;
3509 	}
3510 
3511 	/* Support for GSO partial features requires software
3512 	 * intervention before we can actually process the packets
3513 	 * so we need to strip support for any partial features now
3514 	 * and we can pull them back in after we have partially
3515 	 * segmented the frame.
3516 	 */
3517 	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL))
3518 		features &= ~dev->gso_partial_features;
3519 
3520 	/* Make sure to clear the IPv4 ID mangling feature if the
3521 	 * IPv4 header has the potential to be fragmented.
3522 	 */
3523 	if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
3524 		struct iphdr *iph = skb->encapsulation ?
3525 				    inner_ip_hdr(skb) : ip_hdr(skb);
3526 
3527 		if (!(iph->frag_off & htons(IP_DF)))
3528 			features &= ~NETIF_F_TSO_MANGLEID;
3529 	}
3530 
3531 	return features;
3532 }
3533 
netif_skb_features(struct sk_buff * skb)3534 netdev_features_t netif_skb_features(struct sk_buff *skb)
3535 {
3536 	struct net_device *dev = skb->dev;
3537 	netdev_features_t features = dev->features;
3538 
3539 	if (skb_is_gso(skb))
3540 		features = gso_features_check(skb, dev, features);
3541 
3542 	/* If encapsulation offload request, verify we are testing
3543 	 * hardware encapsulation features instead of standard
3544 	 * features for the netdev
3545 	 */
3546 	if (skb->encapsulation)
3547 		features &= dev->hw_enc_features;
3548 
3549 	if (skb_vlan_tagged(skb))
3550 		features = netdev_intersect_features(features,
3551 						     dev->vlan_features |
3552 						     NETIF_F_HW_VLAN_CTAG_TX |
3553 						     NETIF_F_HW_VLAN_STAG_TX);
3554 
3555 	if (dev->netdev_ops->ndo_features_check)
3556 		features &= dev->netdev_ops->ndo_features_check(skb, dev,
3557 								features);
3558 	else
3559 		features &= dflt_features_check(skb, dev, features);
3560 
3561 	return harmonize_features(skb, features);
3562 }
3563 EXPORT_SYMBOL(netif_skb_features);
3564 
xmit_one(struct sk_buff * skb,struct net_device * dev,struct netdev_queue * txq,bool more)3565 static int xmit_one(struct sk_buff *skb, struct net_device *dev,
3566 		    struct netdev_queue *txq, bool more)
3567 {
3568 	unsigned int len;
3569 	int rc;
3570 
3571 	if (dev_nit_active(dev))
3572 		dev_queue_xmit_nit(skb, dev);
3573 
3574 	len = skb->len;
3575 	trace_net_dev_start_xmit(skb, dev);
3576 	rc = netdev_start_xmit(skb, dev, txq, more);
3577 	trace_net_dev_xmit(skb, rc, dev, len);
3578 
3579 	return rc;
3580 }
3581 
dev_hard_start_xmit(struct sk_buff * first,struct net_device * dev,struct netdev_queue * txq,int * ret)3582 struct sk_buff *dev_hard_start_xmit(struct sk_buff *first, struct net_device *dev,
3583 				    struct netdev_queue *txq, int *ret)
3584 {
3585 	struct sk_buff *skb = first;
3586 	int rc = NETDEV_TX_OK;
3587 
3588 	while (skb) {
3589 		struct sk_buff *next = skb->next;
3590 
3591 		skb_mark_not_on_list(skb);
3592 		rc = xmit_one(skb, dev, txq, next != NULL);
3593 		if (unlikely(!dev_xmit_complete(rc))) {
3594 			skb->next = next;
3595 			goto out;
3596 		}
3597 
3598 		skb = next;
3599 		if (netif_tx_queue_stopped(txq) && skb) {
3600 			rc = NETDEV_TX_BUSY;
3601 			break;
3602 		}
3603 	}
3604 
3605 out:
3606 	*ret = rc;
3607 	return skb;
3608 }
3609 
validate_xmit_vlan(struct sk_buff * skb,netdev_features_t features)3610 static struct sk_buff *validate_xmit_vlan(struct sk_buff *skb,
3611 					  netdev_features_t features)
3612 {
3613 	if (skb_vlan_tag_present(skb) &&
3614 	    !vlan_hw_offload_capable(features, skb->vlan_proto))
3615 		skb = __vlan_hwaccel_push_inside(skb);
3616 	return skb;
3617 }
3618 
skb_csum_hwoffload_help(struct sk_buff * skb,const netdev_features_t features)3619 int skb_csum_hwoffload_help(struct sk_buff *skb,
3620 			    const netdev_features_t features)
3621 {
3622 	if (unlikely(skb_csum_is_sctp(skb)))
3623 		return !!(features & NETIF_F_SCTP_CRC) ? 0 :
3624 			skb_crc32c_csum_help(skb);
3625 
3626 	if (features & NETIF_F_HW_CSUM)
3627 		return 0;
3628 
3629 	if (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) {
3630 		switch (skb->csum_offset) {
3631 		case offsetof(struct tcphdr, check):
3632 		case offsetof(struct udphdr, check):
3633 			return 0;
3634 		}
3635 	}
3636 
3637 	return skb_checksum_help(skb);
3638 }
3639 EXPORT_SYMBOL(skb_csum_hwoffload_help);
3640 
validate_xmit_skb(struct sk_buff * skb,struct net_device * dev,bool * again)3641 static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device *dev, bool *again)
3642 {
3643 	netdev_features_t features;
3644 
3645 	features = netif_skb_features(skb);
3646 	skb = validate_xmit_vlan(skb, features);
3647 	if (unlikely(!skb))
3648 		goto out_null;
3649 
3650 	skb = sk_validate_xmit_skb(skb, dev);
3651 	if (unlikely(!skb))
3652 		goto out_null;
3653 
3654 	if (netif_needs_gso(skb, features)) {
3655 		struct sk_buff *segs;
3656 
3657 		segs = skb_gso_segment(skb, features);
3658 		if (IS_ERR(segs)) {
3659 			goto out_kfree_skb;
3660 		} else if (segs) {
3661 			consume_skb(skb);
3662 			skb = segs;
3663 		}
3664 	} else {
3665 		if (skb_needs_linearize(skb, features) &&
3666 		    __skb_linearize(skb))
3667 			goto out_kfree_skb;
3668 
3669 		/* If packet is not checksummed and device does not
3670 		 * support checksumming for this protocol, complete
3671 		 * checksumming here.
3672 		 */
3673 		if (skb->ip_summed == CHECKSUM_PARTIAL) {
3674 			if (skb->encapsulation)
3675 				skb_set_inner_transport_header(skb,
3676 							       skb_checksum_start_offset(skb));
3677 			else
3678 				skb_set_transport_header(skb,
3679 							 skb_checksum_start_offset(skb));
3680 			if (skb_csum_hwoffload_help(skb, features))
3681 				goto out_kfree_skb;
3682 		}
3683 	}
3684 
3685 	skb = validate_xmit_xfrm(skb, features, again);
3686 
3687 	return skb;
3688 
3689 out_kfree_skb:
3690 	kfree_skb(skb);
3691 out_null:
3692 	dev_core_stats_tx_dropped_inc(dev);
3693 	return NULL;
3694 }
3695 
validate_xmit_skb_list(struct sk_buff * skb,struct net_device * dev,bool * again)3696 struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *dev, bool *again)
3697 {
3698 	struct sk_buff *next, *head = NULL, *tail;
3699 
3700 	for (; skb != NULL; skb = next) {
3701 		next = skb->next;
3702 		skb_mark_not_on_list(skb);
3703 
3704 		/* in case skb wont be segmented, point to itself */
3705 		skb->prev = skb;
3706 
3707 		skb = validate_xmit_skb(skb, dev, again);
3708 		if (!skb)
3709 			continue;
3710 
3711 		if (!head)
3712 			head = skb;
3713 		else
3714 			tail->next = skb;
3715 		/* If skb was segmented, skb->prev points to
3716 		 * the last segment. If not, it still contains skb.
3717 		 */
3718 		tail = skb->prev;
3719 	}
3720 	return head;
3721 }
3722 EXPORT_SYMBOL_GPL(validate_xmit_skb_list);
3723 
qdisc_pkt_len_init(struct sk_buff * skb)3724 static void qdisc_pkt_len_init(struct sk_buff *skb)
3725 {
3726 	const struct skb_shared_info *shinfo = skb_shinfo(skb);
3727 
3728 	qdisc_skb_cb(skb)->pkt_len = skb->len;
3729 
3730 	/* To get more precise estimation of bytes sent on wire,
3731 	 * we add to pkt_len the headers size of all segments
3732 	 */
3733 	if (shinfo->gso_size && skb_transport_header_was_set(skb)) {
3734 		u16 gso_segs = shinfo->gso_segs;
3735 		unsigned int hdr_len;
3736 
3737 		/* mac layer + network layer */
3738 		hdr_len = skb_transport_offset(skb);
3739 
3740 		/* + transport layer */
3741 		if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) {
3742 			const struct tcphdr *th;
3743 			struct tcphdr _tcphdr;
3744 
3745 			th = skb_header_pointer(skb, hdr_len,
3746 						sizeof(_tcphdr), &_tcphdr);
3747 			if (likely(th))
3748 				hdr_len += __tcp_hdrlen(th);
3749 		} else {
3750 			struct udphdr _udphdr;
3751 
3752 			if (skb_header_pointer(skb, hdr_len,
3753 					       sizeof(_udphdr), &_udphdr))
3754 				hdr_len += sizeof(struct udphdr);
3755 		}
3756 
3757 		if (shinfo->gso_type & SKB_GSO_DODGY)
3758 			gso_segs = DIV_ROUND_UP(skb->len - hdr_len,
3759 						shinfo->gso_size);
3760 
3761 		qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len;
3762 	}
3763 }
3764 
dev_qdisc_enqueue(struct sk_buff * skb,struct Qdisc * q,struct sk_buff ** to_free,struct netdev_queue * txq)3765 static int dev_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *q,
3766 			     struct sk_buff **to_free,
3767 			     struct netdev_queue *txq)
3768 {
3769 	int rc;
3770 
3771 	rc = q->enqueue(skb, q, to_free) & NET_XMIT_MASK;
3772 	if (rc == NET_XMIT_SUCCESS)
3773 		trace_qdisc_enqueue(q, txq, skb);
3774 	return rc;
3775 }
3776 
__dev_xmit_skb(struct sk_buff * skb,struct Qdisc * q,struct net_device * dev,struct netdev_queue * txq)3777 static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
3778 				 struct net_device *dev,
3779 				 struct netdev_queue *txq)
3780 {
3781 	spinlock_t *root_lock = qdisc_lock(q);
3782 	struct sk_buff *to_free = NULL;
3783 	bool contended;
3784 	int rc;
3785 
3786 	qdisc_calculate_pkt_len(skb, q);
3787 
3788 	if (q->flags & TCQ_F_NOLOCK) {
3789 		if (q->flags & TCQ_F_CAN_BYPASS && nolock_qdisc_is_empty(q) &&
3790 		    qdisc_run_begin(q)) {
3791 			/* Retest nolock_qdisc_is_empty() within the protection
3792 			 * of q->seqlock to protect from racing with requeuing.
3793 			 */
3794 			if (unlikely(!nolock_qdisc_is_empty(q))) {
3795 				rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3796 				__qdisc_run(q);
3797 				qdisc_run_end(q);
3798 
3799 				goto no_lock_out;
3800 			}
3801 
3802 			qdisc_bstats_cpu_update(q, skb);
3803 			if (sch_direct_xmit(skb, q, dev, txq, NULL, true) &&
3804 			    !nolock_qdisc_is_empty(q))
3805 				__qdisc_run(q);
3806 
3807 			qdisc_run_end(q);
3808 			return NET_XMIT_SUCCESS;
3809 		}
3810 
3811 		rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3812 		qdisc_run(q);
3813 
3814 no_lock_out:
3815 		if (unlikely(to_free))
3816 			kfree_skb_list_reason(to_free,
3817 					      SKB_DROP_REASON_QDISC_DROP);
3818 		return rc;
3819 	}
3820 
3821 	/*
3822 	 * Heuristic to force contended enqueues to serialize on a
3823 	 * separate lock before trying to get qdisc main lock.
3824 	 * This permits qdisc->running owner to get the lock more
3825 	 * often and dequeue packets faster.
3826 	 * On PREEMPT_RT it is possible to preempt the qdisc owner during xmit
3827 	 * and then other tasks will only enqueue packets. The packets will be
3828 	 * sent after the qdisc owner is scheduled again. To prevent this
3829 	 * scenario the task always serialize on the lock.
3830 	 */
3831 	contended = qdisc_is_running(q) || IS_ENABLED(CONFIG_PREEMPT_RT);
3832 	if (unlikely(contended))
3833 		spin_lock(&q->busylock);
3834 
3835 	spin_lock(root_lock);
3836 	if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
3837 		__qdisc_drop(skb, &to_free);
3838 		rc = NET_XMIT_DROP;
3839 	} else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
3840 		   qdisc_run_begin(q)) {
3841 		/*
3842 		 * This is a work-conserving queue; there are no old skbs
3843 		 * waiting to be sent out; and the qdisc is not running -
3844 		 * xmit the skb directly.
3845 		 */
3846 
3847 		qdisc_bstats_update(q, skb);
3848 
3849 		if (sch_direct_xmit(skb, q, dev, txq, root_lock, true)) {
3850 			if (unlikely(contended)) {
3851 				spin_unlock(&q->busylock);
3852 				contended = false;
3853 			}
3854 			__qdisc_run(q);
3855 		}
3856 
3857 		qdisc_run_end(q);
3858 		rc = NET_XMIT_SUCCESS;
3859 	} else {
3860 		rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3861 		if (qdisc_run_begin(q)) {
3862 			if (unlikely(contended)) {
3863 				spin_unlock(&q->busylock);
3864 				contended = false;
3865 			}
3866 			__qdisc_run(q);
3867 			qdisc_run_end(q);
3868 		}
3869 	}
3870 	spin_unlock(root_lock);
3871 	if (unlikely(to_free))
3872 		kfree_skb_list_reason(to_free, SKB_DROP_REASON_QDISC_DROP);
3873 	if (unlikely(contended))
3874 		spin_unlock(&q->busylock);
3875 	return rc;
3876 }
3877 
3878 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
skb_update_prio(struct sk_buff * skb)3879 static void skb_update_prio(struct sk_buff *skb)
3880 {
3881 	const struct netprio_map *map;
3882 	const struct sock *sk;
3883 	unsigned int prioidx;
3884 
3885 	if (skb->priority)
3886 		return;
3887 	map = rcu_dereference_bh(skb->dev->priomap);
3888 	if (!map)
3889 		return;
3890 	sk = skb_to_full_sk(skb);
3891 	if (!sk)
3892 		return;
3893 
3894 	prioidx = sock_cgroup_prioidx(&sk->sk_cgrp_data);
3895 
3896 	if (prioidx < map->priomap_len)
3897 		skb->priority = map->priomap[prioidx];
3898 }
3899 #else
3900 #define skb_update_prio(skb)
3901 #endif
3902 
3903 /**
3904  *	dev_loopback_xmit - loop back @skb
3905  *	@net: network namespace this loopback is happening in
3906  *	@sk:  sk needed to be a netfilter okfn
3907  *	@skb: buffer to transmit
3908  */
dev_loopback_xmit(struct net * net,struct sock * sk,struct sk_buff * skb)3909 int dev_loopback_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
3910 {
3911 	skb_reset_mac_header(skb);
3912 	__skb_pull(skb, skb_network_offset(skb));
3913 	skb->pkt_type = PACKET_LOOPBACK;
3914 	if (skb->ip_summed == CHECKSUM_NONE)
3915 		skb->ip_summed = CHECKSUM_UNNECESSARY;
3916 	DEBUG_NET_WARN_ON_ONCE(!skb_dst(skb));
3917 	skb_dst_force(skb);
3918 	netif_rx(skb);
3919 	return 0;
3920 }
3921 EXPORT_SYMBOL(dev_loopback_xmit);
3922 
3923 #ifdef CONFIG_NET_EGRESS
3924 static struct netdev_queue *
netdev_tx_queue_mapping(struct net_device * dev,struct sk_buff * skb)3925 netdev_tx_queue_mapping(struct net_device *dev, struct sk_buff *skb)
3926 {
3927 	int qm = skb_get_queue_mapping(skb);
3928 
3929 	return netdev_get_tx_queue(dev, netdev_cap_txqueue(dev, qm));
3930 }
3931 
netdev_xmit_txqueue_skipped(void)3932 static bool netdev_xmit_txqueue_skipped(void)
3933 {
3934 	return __this_cpu_read(softnet_data.xmit.skip_txqueue);
3935 }
3936 
netdev_xmit_skip_txqueue(bool skip)3937 void netdev_xmit_skip_txqueue(bool skip)
3938 {
3939 	__this_cpu_write(softnet_data.xmit.skip_txqueue, skip);
3940 }
3941 EXPORT_SYMBOL_GPL(netdev_xmit_skip_txqueue);
3942 #endif /* CONFIG_NET_EGRESS */
3943 
3944 #ifdef CONFIG_NET_XGRESS
tc_run(struct tcx_entry * entry,struct sk_buff * skb)3945 static int tc_run(struct tcx_entry *entry, struct sk_buff *skb)
3946 {
3947 	int ret = TC_ACT_UNSPEC;
3948 #ifdef CONFIG_NET_CLS_ACT
3949 	struct mini_Qdisc *miniq = rcu_dereference_bh(entry->miniq);
3950 	struct tcf_result res;
3951 
3952 	if (!miniq)
3953 		return ret;
3954 
3955 	tc_skb_cb(skb)->mru = 0;
3956 	tc_skb_cb(skb)->post_ct = false;
3957 
3958 	mini_qdisc_bstats_cpu_update(miniq, skb);
3959 	ret = tcf_classify(skb, miniq->block, miniq->filter_list, &res, false);
3960 	/* Only tcf related quirks below. */
3961 	switch (ret) {
3962 	case TC_ACT_SHOT:
3963 		mini_qdisc_qstats_cpu_drop(miniq);
3964 		break;
3965 	case TC_ACT_OK:
3966 	case TC_ACT_RECLASSIFY:
3967 		skb->tc_index = TC_H_MIN(res.classid);
3968 		break;
3969 	}
3970 #endif /* CONFIG_NET_CLS_ACT */
3971 	return ret;
3972 }
3973 
3974 static DEFINE_STATIC_KEY_FALSE(tcx_needed_key);
3975 
tcx_inc(void)3976 void tcx_inc(void)
3977 {
3978 	static_branch_inc(&tcx_needed_key);
3979 }
3980 
tcx_dec(void)3981 void tcx_dec(void)
3982 {
3983 	static_branch_dec(&tcx_needed_key);
3984 }
3985 
3986 static __always_inline enum tcx_action_base
tcx_run(const struct bpf_mprog_entry * entry,struct sk_buff * skb,const bool needs_mac)3987 tcx_run(const struct bpf_mprog_entry *entry, struct sk_buff *skb,
3988 	const bool needs_mac)
3989 {
3990 	const struct bpf_mprog_fp *fp;
3991 	const struct bpf_prog *prog;
3992 	int ret = TCX_NEXT;
3993 
3994 	if (needs_mac)
3995 		__skb_push(skb, skb->mac_len);
3996 	bpf_mprog_foreach_prog(entry, fp, prog) {
3997 		bpf_compute_data_pointers(skb);
3998 		ret = bpf_prog_run(prog, skb);
3999 		if (ret != TCX_NEXT)
4000 			break;
4001 	}
4002 	if (needs_mac)
4003 		__skb_pull(skb, skb->mac_len);
4004 	return tcx_action_code(skb, ret);
4005 }
4006 
4007 static __always_inline struct sk_buff *
sch_handle_ingress(struct sk_buff * skb,struct packet_type ** pt_prev,int * ret,struct net_device * orig_dev,bool * another)4008 sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
4009 		   struct net_device *orig_dev, bool *another)
4010 {
4011 	struct bpf_mprog_entry *entry = rcu_dereference_bh(skb->dev->tcx_ingress);
4012 	int sch_ret;
4013 
4014 	if (!entry)
4015 		return skb;
4016 	if (*pt_prev) {
4017 		*ret = deliver_skb(skb, *pt_prev, orig_dev);
4018 		*pt_prev = NULL;
4019 	}
4020 
4021 	qdisc_skb_cb(skb)->pkt_len = skb->len;
4022 	tcx_set_ingress(skb, true);
4023 
4024 	if (static_branch_unlikely(&tcx_needed_key)) {
4025 		sch_ret = tcx_run(entry, skb, true);
4026 		if (sch_ret != TC_ACT_UNSPEC)
4027 			goto ingress_verdict;
4028 	}
4029 	sch_ret = tc_run(tcx_entry(entry), skb);
4030 ingress_verdict:
4031 	switch (sch_ret) {
4032 	case TC_ACT_REDIRECT:
4033 		/* skb_mac_header check was done by BPF, so we can safely
4034 		 * push the L2 header back before redirecting to another
4035 		 * netdev.
4036 		 */
4037 		__skb_push(skb, skb->mac_len);
4038 		if (skb_do_redirect(skb) == -EAGAIN) {
4039 			__skb_pull(skb, skb->mac_len);
4040 			*another = true;
4041 			break;
4042 		}
4043 		*ret = NET_RX_SUCCESS;
4044 		return NULL;
4045 	case TC_ACT_SHOT:
4046 		kfree_skb_reason(skb, SKB_DROP_REASON_TC_INGRESS);
4047 		*ret = NET_RX_DROP;
4048 		return NULL;
4049 	/* used by tc_run */
4050 	case TC_ACT_STOLEN:
4051 	case TC_ACT_QUEUED:
4052 	case TC_ACT_TRAP:
4053 		consume_skb(skb);
4054 		fallthrough;
4055 	case TC_ACT_CONSUMED:
4056 		*ret = NET_RX_SUCCESS;
4057 		return NULL;
4058 	}
4059 
4060 	return skb;
4061 }
4062 
4063 static __always_inline struct sk_buff *
sch_handle_egress(struct sk_buff * skb,int * ret,struct net_device * dev)4064 sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
4065 {
4066 	struct bpf_mprog_entry *entry = rcu_dereference_bh(dev->tcx_egress);
4067 	int sch_ret;
4068 
4069 	if (!entry)
4070 		return skb;
4071 
4072 	/* qdisc_skb_cb(skb)->pkt_len & tcx_set_ingress() was
4073 	 * already set by the caller.
4074 	 */
4075 	if (static_branch_unlikely(&tcx_needed_key)) {
4076 		sch_ret = tcx_run(entry, skb, false);
4077 		if (sch_ret != TC_ACT_UNSPEC)
4078 			goto egress_verdict;
4079 	}
4080 	sch_ret = tc_run(tcx_entry(entry), skb);
4081 egress_verdict:
4082 	switch (sch_ret) {
4083 	case TC_ACT_REDIRECT:
4084 		/* No need to push/pop skb's mac_header here on egress! */
4085 		skb_do_redirect(skb);
4086 		*ret = NET_XMIT_SUCCESS;
4087 		return NULL;
4088 	case TC_ACT_SHOT:
4089 		kfree_skb_reason(skb, SKB_DROP_REASON_TC_EGRESS);
4090 		*ret = NET_XMIT_DROP;
4091 		return NULL;
4092 	/* used by tc_run */
4093 	case TC_ACT_STOLEN:
4094 	case TC_ACT_QUEUED:
4095 	case TC_ACT_TRAP:
4096 		consume_skb(skb);
4097 		fallthrough;
4098 	case TC_ACT_CONSUMED:
4099 		*ret = NET_XMIT_SUCCESS;
4100 		return NULL;
4101 	}
4102 
4103 	return skb;
4104 }
4105 #else
4106 static __always_inline struct sk_buff *
sch_handle_ingress(struct sk_buff * skb,struct packet_type ** pt_prev,int * ret,struct net_device * orig_dev,bool * another)4107 sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
4108 		   struct net_device *orig_dev, bool *another)
4109 {
4110 	return skb;
4111 }
4112 
4113 static __always_inline struct sk_buff *
sch_handle_egress(struct sk_buff * skb,int * ret,struct net_device * dev)4114 sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
4115 {
4116 	return skb;
4117 }
4118 #endif /* CONFIG_NET_XGRESS */
4119 
4120 #ifdef CONFIG_XPS
__get_xps_queue_idx(struct net_device * dev,struct sk_buff * skb,struct xps_dev_maps * dev_maps,unsigned int tci)4121 static int __get_xps_queue_idx(struct net_device *dev, struct sk_buff *skb,
4122 			       struct xps_dev_maps *dev_maps, unsigned int tci)
4123 {
4124 	int tc = netdev_get_prio_tc_map(dev, skb->priority);
4125 	struct xps_map *map;
4126 	int queue_index = -1;
4127 
4128 	if (tc >= dev_maps->num_tc || tci >= dev_maps->nr_ids)
4129 		return queue_index;
4130 
4131 	tci *= dev_maps->num_tc;
4132 	tci += tc;
4133 
4134 	map = rcu_dereference(dev_maps->attr_map[tci]);
4135 	if (map) {
4136 		if (map->len == 1)
4137 			queue_index = map->queues[0];
4138 		else
4139 			queue_index = map->queues[reciprocal_scale(
4140 						skb_get_hash(skb), map->len)];
4141 		if (unlikely(queue_index >= dev->real_num_tx_queues))
4142 			queue_index = -1;
4143 	}
4144 	return queue_index;
4145 }
4146 #endif
4147 
get_xps_queue(struct net_device * dev,struct net_device * sb_dev,struct sk_buff * skb)4148 static int get_xps_queue(struct net_device *dev, struct net_device *sb_dev,
4149 			 struct sk_buff *skb)
4150 {
4151 #ifdef CONFIG_XPS
4152 	struct xps_dev_maps *dev_maps;
4153 	struct sock *sk = skb->sk;
4154 	int queue_index = -1;
4155 
4156 	if (!static_key_false(&xps_needed))
4157 		return -1;
4158 
4159 	rcu_read_lock();
4160 	if (!static_key_false(&xps_rxqs_needed))
4161 		goto get_cpus_map;
4162 
4163 	dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_RXQS]);
4164 	if (dev_maps) {
4165 		int tci = sk_rx_queue_get(sk);
4166 
4167 		if (tci >= 0)
4168 			queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
4169 							  tci);
4170 	}
4171 
4172 get_cpus_map:
4173 	if (queue_index < 0) {
4174 		dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_CPUS]);
4175 		if (dev_maps) {
4176 			unsigned int tci = skb->sender_cpu - 1;
4177 
4178 			queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
4179 							  tci);
4180 		}
4181 	}
4182 	rcu_read_unlock();
4183 
4184 	return queue_index;
4185 #else
4186 	return -1;
4187 #endif
4188 }
4189 
dev_pick_tx_zero(struct net_device * dev,struct sk_buff * skb,struct net_device * sb_dev)4190 u16 dev_pick_tx_zero(struct net_device *dev, struct sk_buff *skb,
4191 		     struct net_device *sb_dev)
4192 {
4193 	return 0;
4194 }
4195 EXPORT_SYMBOL(dev_pick_tx_zero);
4196 
dev_pick_tx_cpu_id(struct net_device * dev,struct sk_buff * skb,struct net_device * sb_dev)4197 u16 dev_pick_tx_cpu_id(struct net_device *dev, struct sk_buff *skb,
4198 		       struct net_device *sb_dev)
4199 {
4200 	return (u16)raw_smp_processor_id() % dev->real_num_tx_queues;
4201 }
4202 EXPORT_SYMBOL(dev_pick_tx_cpu_id);
4203 
netdev_pick_tx(struct net_device * dev,struct sk_buff * skb,struct net_device * sb_dev)4204 u16 netdev_pick_tx(struct net_device *dev, struct sk_buff *skb,
4205 		     struct net_device *sb_dev)
4206 {
4207 	struct sock *sk = skb->sk;
4208 	int queue_index = sk_tx_queue_get(sk);
4209 
4210 	sb_dev = sb_dev ? : dev;
4211 
4212 	if (queue_index < 0 || skb->ooo_okay ||
4213 	    queue_index >= dev->real_num_tx_queues) {
4214 		int new_index = get_xps_queue(dev, sb_dev, skb);
4215 
4216 		if (new_index < 0)
4217 			new_index = skb_tx_hash(dev, sb_dev, skb);
4218 
4219 		if (queue_index != new_index && sk &&
4220 		    sk_fullsock(sk) &&
4221 		    rcu_access_pointer(sk->sk_dst_cache))
4222 			sk_tx_queue_set(sk, new_index);
4223 
4224 		queue_index = new_index;
4225 	}
4226 
4227 	return queue_index;
4228 }
4229 EXPORT_SYMBOL(netdev_pick_tx);
4230 
netdev_core_pick_tx(struct net_device * dev,struct sk_buff * skb,struct net_device * sb_dev)4231 struct netdev_queue *netdev_core_pick_tx(struct net_device *dev,
4232 					 struct sk_buff *skb,
4233 					 struct net_device *sb_dev)
4234 {
4235 	int queue_index = 0;
4236 
4237 #ifdef CONFIG_XPS
4238 	u32 sender_cpu = skb->sender_cpu - 1;
4239 
4240 	if (sender_cpu >= (u32)NR_CPUS)
4241 		skb->sender_cpu = raw_smp_processor_id() + 1;
4242 #endif
4243 
4244 	if (dev->real_num_tx_queues != 1) {
4245 		const struct net_device_ops *ops = dev->netdev_ops;
4246 
4247 		if (ops->ndo_select_queue)
4248 			queue_index = ops->ndo_select_queue(dev, skb, sb_dev);
4249 		else
4250 			queue_index = netdev_pick_tx(dev, skb, sb_dev);
4251 
4252 		queue_index = netdev_cap_txqueue(dev, queue_index);
4253 	}
4254 
4255 	skb_set_queue_mapping(skb, queue_index);
4256 	return netdev_get_tx_queue(dev, queue_index);
4257 }
4258 
4259 /**
4260  * __dev_queue_xmit() - transmit a buffer
4261  * @skb:	buffer to transmit
4262  * @sb_dev:	suboordinate device used for L2 forwarding offload
4263  *
4264  * Queue a buffer for transmission to a network device. The caller must
4265  * have set the device and priority and built the buffer before calling
4266  * this function. The function can be called from an interrupt.
4267  *
4268  * When calling this method, interrupts MUST be enabled. This is because
4269  * the BH enable code must have IRQs enabled so that it will not deadlock.
4270  *
4271  * Regardless of the return value, the skb is consumed, so it is currently
4272  * difficult to retry a send to this method. (You can bump the ref count
4273  * before sending to hold a reference for retry if you are careful.)
4274  *
4275  * Return:
4276  * * 0				- buffer successfully transmitted
4277  * * positive qdisc return code	- NET_XMIT_DROP etc.
4278  * * negative errno		- other errors
4279  */
__dev_queue_xmit(struct sk_buff * skb,struct net_device * sb_dev)4280 int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
4281 {
4282 	struct net_device *dev = skb->dev;
4283 	struct netdev_queue *txq = NULL;
4284 	struct Qdisc *q;
4285 	int rc = -ENOMEM;
4286 	bool again = false;
4287 
4288 	skb_reset_mac_header(skb);
4289 	skb_assert_len(skb);
4290 
4291 	if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP))
4292 		__skb_tstamp_tx(skb, NULL, NULL, skb->sk, SCM_TSTAMP_SCHED);
4293 
4294 	/* Disable soft irqs for various locks below. Also
4295 	 * stops preemption for RCU.
4296 	 */
4297 	rcu_read_lock_bh();
4298 
4299 	skb_update_prio(skb);
4300 
4301 	qdisc_pkt_len_init(skb);
4302 	tcx_set_ingress(skb, false);
4303 #ifdef CONFIG_NET_EGRESS
4304 	if (static_branch_unlikely(&egress_needed_key)) {
4305 		if (nf_hook_egress_active()) {
4306 			skb = nf_hook_egress(skb, &rc, dev);
4307 			if (!skb)
4308 				goto out;
4309 		}
4310 
4311 		netdev_xmit_skip_txqueue(false);
4312 
4313 		nf_skip_egress(skb, true);
4314 		skb = sch_handle_egress(skb, &rc, dev);
4315 		if (!skb)
4316 			goto out;
4317 		nf_skip_egress(skb, false);
4318 
4319 		if (netdev_xmit_txqueue_skipped())
4320 			txq = netdev_tx_queue_mapping(dev, skb);
4321 	}
4322 #endif
4323 	/* If device/qdisc don't need skb->dst, release it right now while
4324 	 * its hot in this cpu cache.
4325 	 */
4326 	if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
4327 		skb_dst_drop(skb);
4328 	else
4329 		skb_dst_force(skb);
4330 
4331 	if (!txq)
4332 		txq = netdev_core_pick_tx(dev, skb, sb_dev);
4333 
4334 	q = rcu_dereference_bh(txq->qdisc);
4335 
4336 	trace_net_dev_queue(skb);
4337 	if (q->enqueue) {
4338 		rc = __dev_xmit_skb(skb, q, dev, txq);
4339 		goto out;
4340 	}
4341 
4342 	/* The device has no queue. Common case for software devices:
4343 	 * loopback, all the sorts of tunnels...
4344 
4345 	 * Really, it is unlikely that netif_tx_lock protection is necessary
4346 	 * here.  (f.e. loopback and IP tunnels are clean ignoring statistics
4347 	 * counters.)
4348 	 * However, it is possible, that they rely on protection
4349 	 * made by us here.
4350 
4351 	 * Check this and shot the lock. It is not prone from deadlocks.
4352 	 *Either shot noqueue qdisc, it is even simpler 8)
4353 	 */
4354 	if (dev->flags & IFF_UP) {
4355 		int cpu = smp_processor_id(); /* ok because BHs are off */
4356 
4357 		/* Other cpus might concurrently change txq->xmit_lock_owner
4358 		 * to -1 or to their cpu id, but not to our id.
4359 		 */
4360 		if (READ_ONCE(txq->xmit_lock_owner) != cpu) {
4361 			if (dev_xmit_recursion())
4362 				goto recursion_alert;
4363 
4364 			skb = validate_xmit_skb(skb, dev, &again);
4365 			if (!skb)
4366 				goto out;
4367 
4368 			HARD_TX_LOCK(dev, txq, cpu);
4369 
4370 			if (!netif_xmit_stopped(txq)) {
4371 				dev_xmit_recursion_inc();
4372 				skb = dev_hard_start_xmit(skb, dev, txq, &rc);
4373 				dev_xmit_recursion_dec();
4374 				if (dev_xmit_complete(rc)) {
4375 					HARD_TX_UNLOCK(dev, txq);
4376 					goto out;
4377 				}
4378 			}
4379 			HARD_TX_UNLOCK(dev, txq);
4380 			net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
4381 					     dev->name);
4382 		} else {
4383 			/* Recursion is detected! It is possible,
4384 			 * unfortunately
4385 			 */
4386 recursion_alert:
4387 			net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
4388 					     dev->name);
4389 		}
4390 	}
4391 
4392 	rc = -ENETDOWN;
4393 	rcu_read_unlock_bh();
4394 
4395 	dev_core_stats_tx_dropped_inc(dev);
4396 	kfree_skb_list(skb);
4397 	return rc;
4398 out:
4399 	rcu_read_unlock_bh();
4400 	return rc;
4401 }
4402 EXPORT_SYMBOL(__dev_queue_xmit);
4403 
__dev_direct_xmit(struct sk_buff * skb,u16 queue_id)4404 int __dev_direct_xmit(struct sk_buff *skb, u16 queue_id)
4405 {
4406 	struct net_device *dev = skb->dev;
4407 	struct sk_buff *orig_skb = skb;
4408 	struct netdev_queue *txq;
4409 	int ret = NETDEV_TX_BUSY;
4410 	bool again = false;
4411 
4412 	if (unlikely(!netif_running(dev) ||
4413 		     !netif_carrier_ok(dev)))
4414 		goto drop;
4415 
4416 	skb = validate_xmit_skb_list(skb, dev, &again);
4417 	if (skb != orig_skb)
4418 		goto drop;
4419 
4420 	skb_set_queue_mapping(skb, queue_id);
4421 	txq = skb_get_tx_queue(dev, skb);
4422 
4423 	local_bh_disable();
4424 
4425 	dev_xmit_recursion_inc();
4426 	HARD_TX_LOCK(dev, txq, smp_processor_id());
4427 	if (!netif_xmit_frozen_or_drv_stopped(txq))
4428 		ret = netdev_start_xmit(skb, dev, txq, false);
4429 	HARD_TX_UNLOCK(dev, txq);
4430 	dev_xmit_recursion_dec();
4431 
4432 	local_bh_enable();
4433 	return ret;
4434 drop:
4435 	dev_core_stats_tx_dropped_inc(dev);
4436 	kfree_skb_list(skb);
4437 	return NET_XMIT_DROP;
4438 }
4439 EXPORT_SYMBOL(__dev_direct_xmit);
4440 
4441 /*************************************************************************
4442  *			Receiver routines
4443  *************************************************************************/
4444 
4445 int netdev_max_backlog __read_mostly = 1000;
4446 EXPORT_SYMBOL(netdev_max_backlog);
4447 
4448 int netdev_tstamp_prequeue __read_mostly = 1;
4449 unsigned int sysctl_skb_defer_max __read_mostly = 64;
4450 int netdev_budget __read_mostly = 300;
4451 /* Must be at least 2 jiffes to guarantee 1 jiffy timeout */
4452 unsigned int __read_mostly netdev_budget_usecs = 2 * USEC_PER_SEC / HZ;
4453 int weight_p __read_mostly = 64;           /* old backlog weight */
4454 int dev_weight_rx_bias __read_mostly = 1;  /* bias for backlog weight */
4455 int dev_weight_tx_bias __read_mostly = 1;  /* bias for output_queue quota */
4456 int dev_rx_weight __read_mostly = 64;
4457 int dev_tx_weight __read_mostly = 64;
4458 
4459 /* Called with irq disabled */
____napi_schedule(struct softnet_data * sd,struct napi_struct * napi)4460 static inline void ____napi_schedule(struct softnet_data *sd,
4461 				     struct napi_struct *napi)
4462 {
4463 	struct task_struct *thread;
4464 
4465 	lockdep_assert_irqs_disabled();
4466 
4467 	if (test_bit(NAPI_STATE_THREADED, &napi->state)) {
4468 		/* Paired with smp_mb__before_atomic() in
4469 		 * napi_enable()/dev_set_threaded().
4470 		 * Use READ_ONCE() to guarantee a complete
4471 		 * read on napi->thread. Only call
4472 		 * wake_up_process() when it's not NULL.
4473 		 */
4474 		thread = READ_ONCE(napi->thread);
4475 		if (thread) {
4476 			/* Avoid doing set_bit() if the thread is in
4477 			 * INTERRUPTIBLE state, cause napi_thread_wait()
4478 			 * makes sure to proceed with napi polling
4479 			 * if the thread is explicitly woken from here.
4480 			 */
4481 			if (READ_ONCE(thread->__state) != TASK_INTERRUPTIBLE)
4482 				set_bit(NAPI_STATE_SCHED_THREADED, &napi->state);
4483 			wake_up_process(thread);
4484 			return;
4485 		}
4486 	}
4487 
4488 	list_add_tail(&napi->poll_list, &sd->poll_list);
4489 	WRITE_ONCE(napi->list_owner, smp_processor_id());
4490 	/* If not called from net_rx_action()
4491 	 * we have to raise NET_RX_SOFTIRQ.
4492 	 */
4493 	if (!sd->in_net_rx_action)
4494 		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4495 }
4496 
4497 #ifdef CONFIG_RPS
4498 
4499 /* One global table that all flow-based protocols share. */
4500 struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
4501 EXPORT_SYMBOL(rps_sock_flow_table);
4502 u32 rps_cpu_mask __read_mostly;
4503 EXPORT_SYMBOL(rps_cpu_mask);
4504 
4505 struct static_key_false rps_needed __read_mostly;
4506 EXPORT_SYMBOL(rps_needed);
4507 struct static_key_false rfs_needed __read_mostly;
4508 EXPORT_SYMBOL(rfs_needed);
4509 
4510 static struct rps_dev_flow *
set_rps_cpu(struct net_device * dev,struct sk_buff * skb,struct rps_dev_flow * rflow,u16 next_cpu)4511 set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4512 	    struct rps_dev_flow *rflow, u16 next_cpu)
4513 {
4514 	if (next_cpu < nr_cpu_ids) {
4515 #ifdef CONFIG_RFS_ACCEL
4516 		struct netdev_rx_queue *rxqueue;
4517 		struct rps_dev_flow_table *flow_table;
4518 		struct rps_dev_flow *old_rflow;
4519 		u32 flow_id;
4520 		u16 rxq_index;
4521 		int rc;
4522 
4523 		/* Should we steer this flow to a different hardware queue? */
4524 		if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
4525 		    !(dev->features & NETIF_F_NTUPLE))
4526 			goto out;
4527 		rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
4528 		if (rxq_index == skb_get_rx_queue(skb))
4529 			goto out;
4530 
4531 		rxqueue = dev->_rx + rxq_index;
4532 		flow_table = rcu_dereference(rxqueue->rps_flow_table);
4533 		if (!flow_table)
4534 			goto out;
4535 		flow_id = skb_get_hash(skb) & flow_table->mask;
4536 		rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
4537 							rxq_index, flow_id);
4538 		if (rc < 0)
4539 			goto out;
4540 		old_rflow = rflow;
4541 		rflow = &flow_table->flows[flow_id];
4542 		rflow->filter = rc;
4543 		if (old_rflow->filter == rflow->filter)
4544 			old_rflow->filter = RPS_NO_FILTER;
4545 	out:
4546 #endif
4547 		rflow->last_qtail =
4548 			per_cpu(softnet_data, next_cpu).input_queue_head;
4549 	}
4550 
4551 	rflow->cpu = next_cpu;
4552 	return rflow;
4553 }
4554 
4555 /*
4556  * get_rps_cpu is called from netif_receive_skb and returns the target
4557  * CPU from the RPS map of the receiving queue for a given skb.
4558  * rcu_read_lock must be held on entry.
4559  */
get_rps_cpu(struct net_device * dev,struct sk_buff * skb,struct rps_dev_flow ** rflowp)4560 static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4561 		       struct rps_dev_flow **rflowp)
4562 {
4563 	const struct rps_sock_flow_table *sock_flow_table;
4564 	struct netdev_rx_queue *rxqueue = dev->_rx;
4565 	struct rps_dev_flow_table *flow_table;
4566 	struct rps_map *map;
4567 	int cpu = -1;
4568 	u32 tcpu;
4569 	u32 hash;
4570 
4571 	if (skb_rx_queue_recorded(skb)) {
4572 		u16 index = skb_get_rx_queue(skb);
4573 
4574 		if (unlikely(index >= dev->real_num_rx_queues)) {
4575 			WARN_ONCE(dev->real_num_rx_queues > 1,
4576 				  "%s received packet on queue %u, but number "
4577 				  "of RX queues is %u\n",
4578 				  dev->name, index, dev->real_num_rx_queues);
4579 			goto done;
4580 		}
4581 		rxqueue += index;
4582 	}
4583 
4584 	/* Avoid computing hash if RFS/RPS is not active for this rxqueue */
4585 
4586 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
4587 	map = rcu_dereference(rxqueue->rps_map);
4588 	if (!flow_table && !map)
4589 		goto done;
4590 
4591 	skb_reset_network_header(skb);
4592 	hash = skb_get_hash(skb);
4593 	if (!hash)
4594 		goto done;
4595 
4596 	sock_flow_table = rcu_dereference(rps_sock_flow_table);
4597 	if (flow_table && sock_flow_table) {
4598 		struct rps_dev_flow *rflow;
4599 		u32 next_cpu;
4600 		u32 ident;
4601 
4602 		/* First check into global flow table if there is a match.
4603 		 * This READ_ONCE() pairs with WRITE_ONCE() from rps_record_sock_flow().
4604 		 */
4605 		ident = READ_ONCE(sock_flow_table->ents[hash & sock_flow_table->mask]);
4606 		if ((ident ^ hash) & ~rps_cpu_mask)
4607 			goto try_rps;
4608 
4609 		next_cpu = ident & rps_cpu_mask;
4610 
4611 		/* OK, now we know there is a match,
4612 		 * we can look at the local (per receive queue) flow table
4613 		 */
4614 		rflow = &flow_table->flows[hash & flow_table->mask];
4615 		tcpu = rflow->cpu;
4616 
4617 		/*
4618 		 * If the desired CPU (where last recvmsg was done) is
4619 		 * different from current CPU (one in the rx-queue flow
4620 		 * table entry), switch if one of the following holds:
4621 		 *   - Current CPU is unset (>= nr_cpu_ids).
4622 		 *   - Current CPU is offline.
4623 		 *   - The current CPU's queue tail has advanced beyond the
4624 		 *     last packet that was enqueued using this table entry.
4625 		 *     This guarantees that all previous packets for the flow
4626 		 *     have been dequeued, thus preserving in order delivery.
4627 		 */
4628 		if (unlikely(tcpu != next_cpu) &&
4629 		    (tcpu >= nr_cpu_ids || !cpu_online(tcpu) ||
4630 		     ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
4631 		      rflow->last_qtail)) >= 0)) {
4632 			tcpu = next_cpu;
4633 			rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
4634 		}
4635 
4636 		if (tcpu < nr_cpu_ids && cpu_online(tcpu)) {
4637 			*rflowp = rflow;
4638 			cpu = tcpu;
4639 			goto done;
4640 		}
4641 	}
4642 
4643 try_rps:
4644 
4645 	if (map) {
4646 		tcpu = map->cpus[reciprocal_scale(hash, map->len)];
4647 		if (cpu_online(tcpu)) {
4648 			cpu = tcpu;
4649 			goto done;
4650 		}
4651 	}
4652 
4653 done:
4654 	return cpu;
4655 }
4656 
4657 #ifdef CONFIG_RFS_ACCEL
4658 
4659 /**
4660  * rps_may_expire_flow - check whether an RFS hardware filter may be removed
4661  * @dev: Device on which the filter was set
4662  * @rxq_index: RX queue index
4663  * @flow_id: Flow ID passed to ndo_rx_flow_steer()
4664  * @filter_id: Filter ID returned by ndo_rx_flow_steer()
4665  *
4666  * Drivers that implement ndo_rx_flow_steer() should periodically call
4667  * this function for each installed filter and remove the filters for
4668  * which it returns %true.
4669  */
rps_may_expire_flow(struct net_device * dev,u16 rxq_index,u32 flow_id,u16 filter_id)4670 bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
4671 			 u32 flow_id, u16 filter_id)
4672 {
4673 	struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
4674 	struct rps_dev_flow_table *flow_table;
4675 	struct rps_dev_flow *rflow;
4676 	bool expire = true;
4677 	unsigned int cpu;
4678 
4679 	rcu_read_lock();
4680 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
4681 	if (flow_table && flow_id <= flow_table->mask) {
4682 		rflow = &flow_table->flows[flow_id];
4683 		cpu = READ_ONCE(rflow->cpu);
4684 		if (rflow->filter == filter_id && cpu < nr_cpu_ids &&
4685 		    ((int)(per_cpu(softnet_data, cpu).input_queue_head -
4686 			   rflow->last_qtail) <
4687 		     (int)(10 * flow_table->mask)))
4688 			expire = false;
4689 	}
4690 	rcu_read_unlock();
4691 	return expire;
4692 }
4693 EXPORT_SYMBOL(rps_may_expire_flow);
4694 
4695 #endif /* CONFIG_RFS_ACCEL */
4696 
4697 /* Called from hardirq (IPI) context */
rps_trigger_softirq(void * data)4698 static void rps_trigger_softirq(void *data)
4699 {
4700 	struct softnet_data *sd = data;
4701 
4702 	____napi_schedule(sd, &sd->backlog);
4703 	sd->received_rps++;
4704 }
4705 
4706 #endif /* CONFIG_RPS */
4707 
4708 /* Called from hardirq (IPI) context */
trigger_rx_softirq(void * data)4709 static void trigger_rx_softirq(void *data)
4710 {
4711 	struct softnet_data *sd = data;
4712 
4713 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4714 	smp_store_release(&sd->defer_ipi_scheduled, 0);
4715 }
4716 
4717 /*
4718  * After we queued a packet into sd->input_pkt_queue,
4719  * we need to make sure this queue is serviced soon.
4720  *
4721  * - If this is another cpu queue, link it to our rps_ipi_list,
4722  *   and make sure we will process rps_ipi_list from net_rx_action().
4723  *
4724  * - If this is our own queue, NAPI schedule our backlog.
4725  *   Note that this also raises NET_RX_SOFTIRQ.
4726  */
napi_schedule_rps(struct softnet_data * sd)4727 static void napi_schedule_rps(struct softnet_data *sd)
4728 {
4729 	struct softnet_data *mysd = this_cpu_ptr(&softnet_data);
4730 
4731 #ifdef CONFIG_RPS
4732 	if (sd != mysd) {
4733 		sd->rps_ipi_next = mysd->rps_ipi_list;
4734 		mysd->rps_ipi_list = sd;
4735 
4736 		/* If not called from net_rx_action() or napi_threaded_poll()
4737 		 * we have to raise NET_RX_SOFTIRQ.
4738 		 */
4739 		if (!mysd->in_net_rx_action && !mysd->in_napi_threaded_poll)
4740 			__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4741 		return;
4742 	}
4743 #endif /* CONFIG_RPS */
4744 	__napi_schedule_irqoff(&mysd->backlog);
4745 }
4746 
4747 #ifdef CONFIG_NET_FLOW_LIMIT
4748 int netdev_flow_limit_table_len __read_mostly = (1 << 12);
4749 #endif
4750 
skb_flow_limit(struct sk_buff * skb,unsigned int qlen)4751 static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen)
4752 {
4753 #ifdef CONFIG_NET_FLOW_LIMIT
4754 	struct sd_flow_limit *fl;
4755 	struct softnet_data *sd;
4756 	unsigned int old_flow, new_flow;
4757 
4758 	if (qlen < (READ_ONCE(netdev_max_backlog) >> 1))
4759 		return false;
4760 
4761 	sd = this_cpu_ptr(&softnet_data);
4762 
4763 	rcu_read_lock();
4764 	fl = rcu_dereference(sd->flow_limit);
4765 	if (fl) {
4766 		new_flow = skb_get_hash(skb) & (fl->num_buckets - 1);
4767 		old_flow = fl->history[fl->history_head];
4768 		fl->history[fl->history_head] = new_flow;
4769 
4770 		fl->history_head++;
4771 		fl->history_head &= FLOW_LIMIT_HISTORY - 1;
4772 
4773 		if (likely(fl->buckets[old_flow]))
4774 			fl->buckets[old_flow]--;
4775 
4776 		if (++fl->buckets[new_flow] > (FLOW_LIMIT_HISTORY >> 1)) {
4777 			fl->count++;
4778 			rcu_read_unlock();
4779 			return true;
4780 		}
4781 	}
4782 	rcu_read_unlock();
4783 #endif
4784 	return false;
4785 }
4786 
4787 /*
4788  * enqueue_to_backlog is called to queue an skb to a per CPU backlog
4789  * queue (may be a remote CPU queue).
4790  */
enqueue_to_backlog(struct sk_buff * skb,int cpu,unsigned int * qtail)4791 static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
4792 			      unsigned int *qtail)
4793 {
4794 	enum skb_drop_reason reason;
4795 	struct softnet_data *sd;
4796 	unsigned long flags;
4797 	unsigned int qlen;
4798 
4799 	reason = SKB_DROP_REASON_NOT_SPECIFIED;
4800 	sd = &per_cpu(softnet_data, cpu);
4801 
4802 	rps_lock_irqsave(sd, &flags);
4803 	if (!netif_running(skb->dev))
4804 		goto drop;
4805 	qlen = skb_queue_len(&sd->input_pkt_queue);
4806 	if (qlen <= READ_ONCE(netdev_max_backlog) && !skb_flow_limit(skb, qlen)) {
4807 		if (qlen) {
4808 enqueue:
4809 			__skb_queue_tail(&sd->input_pkt_queue, skb);
4810 			input_queue_tail_incr_save(sd, qtail);
4811 			rps_unlock_irq_restore(sd, &flags);
4812 			return NET_RX_SUCCESS;
4813 		}
4814 
4815 		/* Schedule NAPI for backlog device
4816 		 * We can use non atomic operation since we own the queue lock
4817 		 */
4818 		if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state))
4819 			napi_schedule_rps(sd);
4820 		goto enqueue;
4821 	}
4822 	reason = SKB_DROP_REASON_CPU_BACKLOG;
4823 
4824 drop:
4825 	sd->dropped++;
4826 	rps_unlock_irq_restore(sd, &flags);
4827 
4828 	dev_core_stats_rx_dropped_inc(skb->dev);
4829 	kfree_skb_reason(skb, reason);
4830 	return NET_RX_DROP;
4831 }
4832 
netif_get_rxqueue(struct sk_buff * skb)4833 static struct netdev_rx_queue *netif_get_rxqueue(struct sk_buff *skb)
4834 {
4835 	struct net_device *dev = skb->dev;
4836 	struct netdev_rx_queue *rxqueue;
4837 
4838 	rxqueue = dev->_rx;
4839 
4840 	if (skb_rx_queue_recorded(skb)) {
4841 		u16 index = skb_get_rx_queue(skb);
4842 
4843 		if (unlikely(index >= dev->real_num_rx_queues)) {
4844 			WARN_ONCE(dev->real_num_rx_queues > 1,
4845 				  "%s received packet on queue %u, but number "
4846 				  "of RX queues is %u\n",
4847 				  dev->name, index, dev->real_num_rx_queues);
4848 
4849 			return rxqueue; /* Return first rxqueue */
4850 		}
4851 		rxqueue += index;
4852 	}
4853 	return rxqueue;
4854 }
4855 
bpf_prog_run_generic_xdp(struct sk_buff * skb,struct xdp_buff * xdp,struct bpf_prog * xdp_prog)4856 u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp,
4857 			     struct bpf_prog *xdp_prog)
4858 {
4859 	void *orig_data, *orig_data_end, *hard_start;
4860 	struct netdev_rx_queue *rxqueue;
4861 	bool orig_bcast, orig_host;
4862 	u32 mac_len, frame_sz;
4863 	__be16 orig_eth_type;
4864 	struct ethhdr *eth;
4865 	u32 metalen, act;
4866 	int off;
4867 
4868 	/* The XDP program wants to see the packet starting at the MAC
4869 	 * header.
4870 	 */
4871 	mac_len = skb->data - skb_mac_header(skb);
4872 	hard_start = skb->data - skb_headroom(skb);
4873 
4874 	/* SKB "head" area always have tailroom for skb_shared_info */
4875 	frame_sz = (void *)skb_end_pointer(skb) - hard_start;
4876 	frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
4877 
4878 	rxqueue = netif_get_rxqueue(skb);
4879 	xdp_init_buff(xdp, frame_sz, &rxqueue->xdp_rxq);
4880 	xdp_prepare_buff(xdp, hard_start, skb_headroom(skb) - mac_len,
4881 			 skb_headlen(skb) + mac_len, true);
4882 
4883 	orig_data_end = xdp->data_end;
4884 	orig_data = xdp->data;
4885 	eth = (struct ethhdr *)xdp->data;
4886 	orig_host = ether_addr_equal_64bits(eth->h_dest, skb->dev->dev_addr);
4887 	orig_bcast = is_multicast_ether_addr_64bits(eth->h_dest);
4888 	orig_eth_type = eth->h_proto;
4889 
4890 	act = bpf_prog_run_xdp(xdp_prog, xdp);
4891 
4892 	/* check if bpf_xdp_adjust_head was used */
4893 	off = xdp->data - orig_data;
4894 	if (off) {
4895 		if (off > 0)
4896 			__skb_pull(skb, off);
4897 		else if (off < 0)
4898 			__skb_push(skb, -off);
4899 
4900 		skb->mac_header += off;
4901 		skb_reset_network_header(skb);
4902 	}
4903 
4904 	/* check if bpf_xdp_adjust_tail was used */
4905 	off = xdp->data_end - orig_data_end;
4906 	if (off != 0) {
4907 		skb_set_tail_pointer(skb, xdp->data_end - xdp->data);
4908 		skb->len += off; /* positive on grow, negative on shrink */
4909 	}
4910 
4911 	/* check if XDP changed eth hdr such SKB needs update */
4912 	eth = (struct ethhdr *)xdp->data;
4913 	if ((orig_eth_type != eth->h_proto) ||
4914 	    (orig_host != ether_addr_equal_64bits(eth->h_dest,
4915 						  skb->dev->dev_addr)) ||
4916 	    (orig_bcast != is_multicast_ether_addr_64bits(eth->h_dest))) {
4917 		__skb_push(skb, ETH_HLEN);
4918 		skb->pkt_type = PACKET_HOST;
4919 		skb->protocol = eth_type_trans(skb, skb->dev);
4920 	}
4921 
4922 	/* Redirect/Tx gives L2 packet, code that will reuse skb must __skb_pull
4923 	 * before calling us again on redirect path. We do not call do_redirect
4924 	 * as we leave that up to the caller.
4925 	 *
4926 	 * Caller is responsible for managing lifetime of skb (i.e. calling
4927 	 * kfree_skb in response to actions it cannot handle/XDP_DROP).
4928 	 */
4929 	switch (act) {
4930 	case XDP_REDIRECT:
4931 	case XDP_TX:
4932 		__skb_push(skb, mac_len);
4933 		break;
4934 	case XDP_PASS:
4935 		metalen = xdp->data - xdp->data_meta;
4936 		if (metalen)
4937 			skb_metadata_set(skb, metalen);
4938 		break;
4939 	}
4940 
4941 	return act;
4942 }
4943 
netif_receive_generic_xdp(struct sk_buff * skb,struct xdp_buff * xdp,struct bpf_prog * xdp_prog)4944 static u32 netif_receive_generic_xdp(struct sk_buff *skb,
4945 				     struct xdp_buff *xdp,
4946 				     struct bpf_prog *xdp_prog)
4947 {
4948 	u32 act = XDP_DROP;
4949 
4950 	/* Reinjected packets coming from act_mirred or similar should
4951 	 * not get XDP generic processing.
4952 	 */
4953 	if (skb_is_redirected(skb))
4954 		return XDP_PASS;
4955 
4956 	/* XDP packets must be linear and must have sufficient headroom
4957 	 * of XDP_PACKET_HEADROOM bytes. This is the guarantee that also
4958 	 * native XDP provides, thus we need to do it here as well.
4959 	 */
4960 	if (skb_cloned(skb) || skb_is_nonlinear(skb) ||
4961 	    skb_headroom(skb) < XDP_PACKET_HEADROOM) {
4962 		int hroom = XDP_PACKET_HEADROOM - skb_headroom(skb);
4963 		int troom = skb->tail + skb->data_len - skb->end;
4964 
4965 		/* In case we have to go down the path and also linearize,
4966 		 * then lets do the pskb_expand_head() work just once here.
4967 		 */
4968 		if (pskb_expand_head(skb,
4969 				     hroom > 0 ? ALIGN(hroom, NET_SKB_PAD) : 0,
4970 				     troom > 0 ? troom + 128 : 0, GFP_ATOMIC))
4971 			goto do_drop;
4972 		if (skb_linearize(skb))
4973 			goto do_drop;
4974 	}
4975 
4976 	act = bpf_prog_run_generic_xdp(skb, xdp, xdp_prog);
4977 	switch (act) {
4978 	case XDP_REDIRECT:
4979 	case XDP_TX:
4980 	case XDP_PASS:
4981 		break;
4982 	default:
4983 		bpf_warn_invalid_xdp_action(skb->dev, xdp_prog, act);
4984 		fallthrough;
4985 	case XDP_ABORTED:
4986 		trace_xdp_exception(skb->dev, xdp_prog, act);
4987 		fallthrough;
4988 	case XDP_DROP:
4989 	do_drop:
4990 		kfree_skb(skb);
4991 		break;
4992 	}
4993 
4994 	return act;
4995 }
4996 
4997 /* When doing generic XDP we have to bypass the qdisc layer and the
4998  * network taps in order to match in-driver-XDP behavior. This also means
4999  * that XDP packets are able to starve other packets going through a qdisc,
5000  * and DDOS attacks will be more effective. In-driver-XDP use dedicated TX
5001  * queues, so they do not have this starvation issue.
5002  */
generic_xdp_tx(struct sk_buff * skb,struct bpf_prog * xdp_prog)5003 void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
5004 {
5005 	struct net_device *dev = skb->dev;
5006 	struct netdev_queue *txq;
5007 	bool free_skb = true;
5008 	int cpu, rc;
5009 
5010 	txq = netdev_core_pick_tx(dev, skb, NULL);
5011 	cpu = smp_processor_id();
5012 	HARD_TX_LOCK(dev, txq, cpu);
5013 	if (!netif_xmit_frozen_or_drv_stopped(txq)) {
5014 		rc = netdev_start_xmit(skb, dev, txq, 0);
5015 		if (dev_xmit_complete(rc))
5016 			free_skb = false;
5017 	}
5018 	HARD_TX_UNLOCK(dev, txq);
5019 	if (free_skb) {
5020 		trace_xdp_exception(dev, xdp_prog, XDP_TX);
5021 		dev_core_stats_tx_dropped_inc(dev);
5022 		kfree_skb(skb);
5023 	}
5024 }
5025 
5026 static DEFINE_STATIC_KEY_FALSE(generic_xdp_needed_key);
5027 
do_xdp_generic(struct bpf_prog * xdp_prog,struct sk_buff * skb)5028 int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb)
5029 {
5030 	if (xdp_prog) {
5031 		struct xdp_buff xdp;
5032 		u32 act;
5033 		int err;
5034 
5035 		act = netif_receive_generic_xdp(skb, &xdp, xdp_prog);
5036 		if (act != XDP_PASS) {
5037 			switch (act) {
5038 			case XDP_REDIRECT:
5039 				err = xdp_do_generic_redirect(skb->dev, skb,
5040 							      &xdp, xdp_prog);
5041 				if (err)
5042 					goto out_redir;
5043 				break;
5044 			case XDP_TX:
5045 				generic_xdp_tx(skb, xdp_prog);
5046 				break;
5047 			}
5048 			return XDP_DROP;
5049 		}
5050 	}
5051 	return XDP_PASS;
5052 out_redir:
5053 	kfree_skb_reason(skb, SKB_DROP_REASON_XDP);
5054 	return XDP_DROP;
5055 }
5056 EXPORT_SYMBOL_GPL(do_xdp_generic);
5057 
netif_rx_internal(struct sk_buff * skb)5058 static int netif_rx_internal(struct sk_buff *skb)
5059 {
5060 	int ret;
5061 
5062 	net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
5063 
5064 	trace_netif_rx(skb);
5065 
5066 #ifdef CONFIG_RPS
5067 	if (static_branch_unlikely(&rps_needed)) {
5068 		struct rps_dev_flow voidflow, *rflow = &voidflow;
5069 		int cpu;
5070 
5071 		rcu_read_lock();
5072 
5073 		cpu = get_rps_cpu(skb->dev, skb, &rflow);
5074 		if (cpu < 0)
5075 			cpu = smp_processor_id();
5076 
5077 		ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5078 
5079 		rcu_read_unlock();
5080 	} else
5081 #endif
5082 	{
5083 		unsigned int qtail;
5084 
5085 		ret = enqueue_to_backlog(skb, smp_processor_id(), &qtail);
5086 	}
5087 	return ret;
5088 }
5089 
5090 /**
5091  *	__netif_rx	-	Slightly optimized version of netif_rx
5092  *	@skb: buffer to post
5093  *
5094  *	This behaves as netif_rx except that it does not disable bottom halves.
5095  *	As a result this function may only be invoked from the interrupt context
5096  *	(either hard or soft interrupt).
5097  */
__netif_rx(struct sk_buff * skb)5098 int __netif_rx(struct sk_buff *skb)
5099 {
5100 	int ret;
5101 
5102 	lockdep_assert_once(hardirq_count() | softirq_count());
5103 
5104 	trace_netif_rx_entry(skb);
5105 	ret = netif_rx_internal(skb);
5106 	trace_netif_rx_exit(ret);
5107 	return ret;
5108 }
5109 EXPORT_SYMBOL(__netif_rx);
5110 
5111 /**
5112  *	netif_rx	-	post buffer to the network code
5113  *	@skb: buffer to post
5114  *
5115  *	This function receives a packet from a device driver and queues it for
5116  *	the upper (protocol) levels to process via the backlog NAPI device. It
5117  *	always succeeds. The buffer may be dropped during processing for
5118  *	congestion control or by the protocol layers.
5119  *	The network buffer is passed via the backlog NAPI device. Modern NIC
5120  *	driver should use NAPI and GRO.
5121  *	This function can used from interrupt and from process context. The
5122  *	caller from process context must not disable interrupts before invoking
5123  *	this function.
5124  *
5125  *	return values:
5126  *	NET_RX_SUCCESS	(no congestion)
5127  *	NET_RX_DROP     (packet was dropped)
5128  *
5129  */
netif_rx(struct sk_buff * skb)5130 int netif_rx(struct sk_buff *skb)
5131 {
5132 	bool need_bh_off = !(hardirq_count() | softirq_count());
5133 	int ret;
5134 
5135 	if (need_bh_off)
5136 		local_bh_disable();
5137 	trace_netif_rx_entry(skb);
5138 	ret = netif_rx_internal(skb);
5139 	trace_netif_rx_exit(ret);
5140 	if (need_bh_off)
5141 		local_bh_enable();
5142 	return ret;
5143 }
5144 EXPORT_SYMBOL(netif_rx);
5145 
net_tx_action(struct softirq_action * h)5146 static __latent_entropy void net_tx_action(struct softirq_action *h)
5147 {
5148 	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
5149 
5150 	if (sd->completion_queue) {
5151 		struct sk_buff *clist;
5152 
5153 		local_irq_disable();
5154 		clist = sd->completion_queue;
5155 		sd->completion_queue = NULL;
5156 		local_irq_enable();
5157 
5158 		while (clist) {
5159 			struct sk_buff *skb = clist;
5160 
5161 			clist = clist->next;
5162 
5163 			WARN_ON(refcount_read(&skb->users));
5164 			if (likely(get_kfree_skb_cb(skb)->reason == SKB_CONSUMED))
5165 				trace_consume_skb(skb, net_tx_action);
5166 			else
5167 				trace_kfree_skb(skb, net_tx_action,
5168 						get_kfree_skb_cb(skb)->reason);
5169 
5170 			if (skb->fclone != SKB_FCLONE_UNAVAILABLE)
5171 				__kfree_skb(skb);
5172 			else
5173 				__napi_kfree_skb(skb,
5174 						 get_kfree_skb_cb(skb)->reason);
5175 		}
5176 	}
5177 
5178 	if (sd->output_queue) {
5179 		struct Qdisc *head;
5180 
5181 		local_irq_disable();
5182 		head = sd->output_queue;
5183 		sd->output_queue = NULL;
5184 		sd->output_queue_tailp = &sd->output_queue;
5185 		local_irq_enable();
5186 
5187 		rcu_read_lock();
5188 
5189 		while (head) {
5190 			struct Qdisc *q = head;
5191 			spinlock_t *root_lock = NULL;
5192 
5193 			head = head->next_sched;
5194 
5195 			/* We need to make sure head->next_sched is read
5196 			 * before clearing __QDISC_STATE_SCHED
5197 			 */
5198 			smp_mb__before_atomic();
5199 
5200 			if (!(q->flags & TCQ_F_NOLOCK)) {
5201 				root_lock = qdisc_lock(q);
5202 				spin_lock(root_lock);
5203 			} else if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED,
5204 						     &q->state))) {
5205 				/* There is a synchronize_net() between
5206 				 * STATE_DEACTIVATED flag being set and
5207 				 * qdisc_reset()/some_qdisc_is_busy() in
5208 				 * dev_deactivate(), so we can safely bail out
5209 				 * early here to avoid data race between
5210 				 * qdisc_deactivate() and some_qdisc_is_busy()
5211 				 * for lockless qdisc.
5212 				 */
5213 				clear_bit(__QDISC_STATE_SCHED, &q->state);
5214 				continue;
5215 			}
5216 
5217 			clear_bit(__QDISC_STATE_SCHED, &q->state);
5218 			qdisc_run(q);
5219 			if (root_lock)
5220 				spin_unlock(root_lock);
5221 		}
5222 
5223 		rcu_read_unlock();
5224 	}
5225 
5226 	xfrm_dev_backlog(sd);
5227 }
5228 
5229 #if IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_ATM_LANE)
5230 /* This hook is defined here for ATM LANE */
5231 int (*br_fdb_test_addr_hook)(struct net_device *dev,
5232 			     unsigned char *addr) __read_mostly;
5233 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
5234 #endif
5235 
5236 /**
5237  *	netdev_is_rx_handler_busy - check if receive handler is registered
5238  *	@dev: device to check
5239  *
5240  *	Check if a receive handler is already registered for a given device.
5241  *	Return true if there one.
5242  *
5243  *	The caller must hold the rtnl_mutex.
5244  */
netdev_is_rx_handler_busy(struct net_device * dev)5245 bool netdev_is_rx_handler_busy(struct net_device *dev)
5246 {
5247 	ASSERT_RTNL();
5248 	return dev && rtnl_dereference(dev->rx_handler);
5249 }
5250 EXPORT_SYMBOL_GPL(netdev_is_rx_handler_busy);
5251 
5252 /**
5253  *	netdev_rx_handler_register - register receive handler
5254  *	@dev: device to register a handler for
5255  *	@rx_handler: receive handler to register
5256  *	@rx_handler_data: data pointer that is used by rx handler
5257  *
5258  *	Register a receive handler for a device. This handler will then be
5259  *	called from __netif_receive_skb. A negative errno code is returned
5260  *	on a failure.
5261  *
5262  *	The caller must hold the rtnl_mutex.
5263  *
5264  *	For a general description of rx_handler, see enum rx_handler_result.
5265  */
netdev_rx_handler_register(struct net_device * dev,rx_handler_func_t * rx_handler,void * rx_handler_data)5266 int netdev_rx_handler_register(struct net_device *dev,
5267 			       rx_handler_func_t *rx_handler,
5268 			       void *rx_handler_data)
5269 {
5270 	if (netdev_is_rx_handler_busy(dev))
5271 		return -EBUSY;
5272 
5273 	if (dev->priv_flags & IFF_NO_RX_HANDLER)
5274 		return -EINVAL;
5275 
5276 	/* Note: rx_handler_data must be set before rx_handler */
5277 	rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
5278 	rcu_assign_pointer(dev->rx_handler, rx_handler);
5279 
5280 	return 0;
5281 }
5282 EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
5283 
5284 /**
5285  *	netdev_rx_handler_unregister - unregister receive handler
5286  *	@dev: device to unregister a handler from
5287  *
5288  *	Unregister a receive handler from a device.
5289  *
5290  *	The caller must hold the rtnl_mutex.
5291  */
netdev_rx_handler_unregister(struct net_device * dev)5292 void netdev_rx_handler_unregister(struct net_device *dev)
5293 {
5294 
5295 	ASSERT_RTNL();
5296 	RCU_INIT_POINTER(dev->rx_handler, NULL);
5297 	/* a reader seeing a non NULL rx_handler in a rcu_read_lock()
5298 	 * section has a guarantee to see a non NULL rx_handler_data
5299 	 * as well.
5300 	 */
5301 	synchronize_net();
5302 	RCU_INIT_POINTER(dev->rx_handler_data, NULL);
5303 }
5304 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
5305 
5306 /*
5307  * Limit the use of PFMEMALLOC reserves to those protocols that implement
5308  * the special handling of PFMEMALLOC skbs.
5309  */
skb_pfmemalloc_protocol(struct sk_buff * skb)5310 static bool skb_pfmemalloc_protocol(struct sk_buff *skb)
5311 {
5312 	switch (skb->protocol) {
5313 	case htons(ETH_P_ARP):
5314 	case htons(ETH_P_IP):
5315 	case htons(ETH_P_IPV6):
5316 	case htons(ETH_P_8021Q):
5317 	case htons(ETH_P_8021AD):
5318 		return true;
5319 	default:
5320 		return false;
5321 	}
5322 }
5323 
nf_ingress(struct sk_buff * skb,struct packet_type ** pt_prev,int * ret,struct net_device * orig_dev)5324 static inline int nf_ingress(struct sk_buff *skb, struct packet_type **pt_prev,
5325 			     int *ret, struct net_device *orig_dev)
5326 {
5327 	if (nf_hook_ingress_active(skb)) {
5328 		int ingress_retval;
5329 
5330 		if (*pt_prev) {
5331 			*ret = deliver_skb(skb, *pt_prev, orig_dev);
5332 			*pt_prev = NULL;
5333 		}
5334 
5335 		rcu_read_lock();
5336 		ingress_retval = nf_hook_ingress(skb);
5337 		rcu_read_unlock();
5338 		return ingress_retval;
5339 	}
5340 	return 0;
5341 }
5342 
__netif_receive_skb_core(struct sk_buff ** pskb,bool pfmemalloc,struct packet_type ** ppt_prev)5343 static int __netif_receive_skb_core(struct sk_buff **pskb, bool pfmemalloc,
5344 				    struct packet_type **ppt_prev)
5345 {
5346 	struct packet_type *ptype, *pt_prev;
5347 	rx_handler_func_t *rx_handler;
5348 	struct sk_buff *skb = *pskb;
5349 	struct net_device *orig_dev;
5350 	bool deliver_exact = false;
5351 	int ret = NET_RX_DROP;
5352 	__be16 type;
5353 
5354 	net_timestamp_check(!READ_ONCE(netdev_tstamp_prequeue), skb);
5355 
5356 	trace_netif_receive_skb(skb);
5357 
5358 	orig_dev = skb->dev;
5359 
5360 	skb_reset_network_header(skb);
5361 	if (!skb_transport_header_was_set(skb))
5362 		skb_reset_transport_header(skb);
5363 	skb_reset_mac_len(skb);
5364 
5365 	pt_prev = NULL;
5366 
5367 another_round:
5368 	skb->skb_iif = skb->dev->ifindex;
5369 
5370 	__this_cpu_inc(softnet_data.processed);
5371 
5372 	if (static_branch_unlikely(&generic_xdp_needed_key)) {
5373 		int ret2;
5374 
5375 		migrate_disable();
5376 		ret2 = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog), skb);
5377 		migrate_enable();
5378 
5379 		if (ret2 != XDP_PASS) {
5380 			ret = NET_RX_DROP;
5381 			goto out;
5382 		}
5383 	}
5384 
5385 	if (eth_type_vlan(skb->protocol)) {
5386 		skb = skb_vlan_untag(skb);
5387 		if (unlikely(!skb))
5388 			goto out;
5389 	}
5390 
5391 	if (skb_skip_tc_classify(skb))
5392 		goto skip_classify;
5393 
5394 	if (pfmemalloc)
5395 		goto skip_taps;
5396 
5397 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
5398 		if (pt_prev)
5399 			ret = deliver_skb(skb, pt_prev, orig_dev);
5400 		pt_prev = ptype;
5401 	}
5402 
5403 	list_for_each_entry_rcu(ptype, &skb->dev->ptype_all, list) {
5404 		if (pt_prev)
5405 			ret = deliver_skb(skb, pt_prev, orig_dev);
5406 		pt_prev = ptype;
5407 	}
5408 
5409 skip_taps:
5410 #ifdef CONFIG_NET_INGRESS
5411 	if (static_branch_unlikely(&ingress_needed_key)) {
5412 		bool another = false;
5413 
5414 		nf_skip_egress(skb, true);
5415 		skb = sch_handle_ingress(skb, &pt_prev, &ret, orig_dev,
5416 					 &another);
5417 		if (another)
5418 			goto another_round;
5419 		if (!skb)
5420 			goto out;
5421 
5422 		nf_skip_egress(skb, false);
5423 		if (nf_ingress(skb, &pt_prev, &ret, orig_dev) < 0)
5424 			goto out;
5425 	}
5426 #endif
5427 	skb_reset_redirect(skb);
5428 skip_classify:
5429 	if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
5430 		goto drop;
5431 
5432 	if (skb_vlan_tag_present(skb)) {
5433 		if (pt_prev) {
5434 			ret = deliver_skb(skb, pt_prev, orig_dev);
5435 			pt_prev = NULL;
5436 		}
5437 		if (vlan_do_receive(&skb))
5438 			goto another_round;
5439 		else if (unlikely(!skb))
5440 			goto out;
5441 	}
5442 
5443 	rx_handler = rcu_dereference(skb->dev->rx_handler);
5444 	if (rx_handler) {
5445 		if (pt_prev) {
5446 			ret = deliver_skb(skb, pt_prev, orig_dev);
5447 			pt_prev = NULL;
5448 		}
5449 		switch (rx_handler(&skb)) {
5450 		case RX_HANDLER_CONSUMED:
5451 			ret = NET_RX_SUCCESS;
5452 			goto out;
5453 		case RX_HANDLER_ANOTHER:
5454 			goto another_round;
5455 		case RX_HANDLER_EXACT:
5456 			deliver_exact = true;
5457 			break;
5458 		case RX_HANDLER_PASS:
5459 			break;
5460 		default:
5461 			BUG();
5462 		}
5463 	}
5464 
5465 	if (unlikely(skb_vlan_tag_present(skb)) && !netdev_uses_dsa(skb->dev)) {
5466 check_vlan_id:
5467 		if (skb_vlan_tag_get_id(skb)) {
5468 			/* Vlan id is non 0 and vlan_do_receive() above couldn't
5469 			 * find vlan device.
5470 			 */
5471 			skb->pkt_type = PACKET_OTHERHOST;
5472 		} else if (eth_type_vlan(skb->protocol)) {
5473 			/* Outer header is 802.1P with vlan 0, inner header is
5474 			 * 802.1Q or 802.1AD and vlan_do_receive() above could
5475 			 * not find vlan dev for vlan id 0.
5476 			 */
5477 			__vlan_hwaccel_clear_tag(skb);
5478 			skb = skb_vlan_untag(skb);
5479 			if (unlikely(!skb))
5480 				goto out;
5481 			if (vlan_do_receive(&skb))
5482 				/* After stripping off 802.1P header with vlan 0
5483 				 * vlan dev is found for inner header.
5484 				 */
5485 				goto another_round;
5486 			else if (unlikely(!skb))
5487 				goto out;
5488 			else
5489 				/* We have stripped outer 802.1P vlan 0 header.
5490 				 * But could not find vlan dev.
5491 				 * check again for vlan id to set OTHERHOST.
5492 				 */
5493 				goto check_vlan_id;
5494 		}
5495 		/* Note: we might in the future use prio bits
5496 		 * and set skb->priority like in vlan_do_receive()
5497 		 * For the time being, just ignore Priority Code Point
5498 		 */
5499 		__vlan_hwaccel_clear_tag(skb);
5500 	}
5501 
5502 	type = skb->protocol;
5503 
5504 	/* deliver only exact match when indicated */
5505 	if (likely(!deliver_exact)) {
5506 		deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5507 				       &ptype_base[ntohs(type) &
5508 						   PTYPE_HASH_MASK]);
5509 	}
5510 
5511 	deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5512 			       &orig_dev->ptype_specific);
5513 
5514 	if (unlikely(skb->dev != orig_dev)) {
5515 		deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5516 				       &skb->dev->ptype_specific);
5517 	}
5518 
5519 	if (pt_prev) {
5520 		if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
5521 			goto drop;
5522 		*ppt_prev = pt_prev;
5523 	} else {
5524 drop:
5525 		if (!deliver_exact)
5526 			dev_core_stats_rx_dropped_inc(skb->dev);
5527 		else
5528 			dev_core_stats_rx_nohandler_inc(skb->dev);
5529 		kfree_skb_reason(skb, SKB_DROP_REASON_UNHANDLED_PROTO);
5530 		/* Jamal, now you will not able to escape explaining
5531 		 * me how you were going to use this. :-)
5532 		 */
5533 		ret = NET_RX_DROP;
5534 	}
5535 
5536 out:
5537 	/* The invariant here is that if *ppt_prev is not NULL
5538 	 * then skb should also be non-NULL.
5539 	 *
5540 	 * Apparently *ppt_prev assignment above holds this invariant due to
5541 	 * skb dereferencing near it.
5542 	 */
5543 	*pskb = skb;
5544 	return ret;
5545 }
5546 
__netif_receive_skb_one_core(struct sk_buff * skb,bool pfmemalloc)5547 static int __netif_receive_skb_one_core(struct sk_buff *skb, bool pfmemalloc)
5548 {
5549 	struct net_device *orig_dev = skb->dev;
5550 	struct packet_type *pt_prev = NULL;
5551 	int ret;
5552 
5553 	ret = __netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5554 	if (pt_prev)
5555 		ret = INDIRECT_CALL_INET(pt_prev->func, ipv6_rcv, ip_rcv, skb,
5556 					 skb->dev, pt_prev, orig_dev);
5557 	return ret;
5558 }
5559 
5560 /**
5561  *	netif_receive_skb_core - special purpose version of netif_receive_skb
5562  *	@skb: buffer to process
5563  *
5564  *	More direct receive version of netif_receive_skb().  It should
5565  *	only be used by callers that have a need to skip RPS and Generic XDP.
5566  *	Caller must also take care of handling if ``(page_is_)pfmemalloc``.
5567  *
5568  *	This function may only be called from softirq context and interrupts
5569  *	should be enabled.
5570  *
5571  *	Return values (usually ignored):
5572  *	NET_RX_SUCCESS: no congestion
5573  *	NET_RX_DROP: packet was dropped
5574  */
netif_receive_skb_core(struct sk_buff * skb)5575 int netif_receive_skb_core(struct sk_buff *skb)
5576 {
5577 	int ret;
5578 
5579 	rcu_read_lock();
5580 	ret = __netif_receive_skb_one_core(skb, false);
5581 	rcu_read_unlock();
5582 
5583 	return ret;
5584 }
5585 EXPORT_SYMBOL(netif_receive_skb_core);
5586 
__netif_receive_skb_list_ptype(struct list_head * head,struct packet_type * pt_prev,struct net_device * orig_dev)5587 static inline void __netif_receive_skb_list_ptype(struct list_head *head,
5588 						  struct packet_type *pt_prev,
5589 						  struct net_device *orig_dev)
5590 {
5591 	struct sk_buff *skb, *next;
5592 
5593 	if (!pt_prev)
5594 		return;
5595 	if (list_empty(head))
5596 		return;
5597 	if (pt_prev->list_func != NULL)
5598 		INDIRECT_CALL_INET(pt_prev->list_func, ipv6_list_rcv,
5599 				   ip_list_rcv, head, pt_prev, orig_dev);
5600 	else
5601 		list_for_each_entry_safe(skb, next, head, list) {
5602 			skb_list_del_init(skb);
5603 			pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
5604 		}
5605 }
5606 
__netif_receive_skb_list_core(struct list_head * head,bool pfmemalloc)5607 static void __netif_receive_skb_list_core(struct list_head *head, bool pfmemalloc)
5608 {
5609 	/* Fast-path assumptions:
5610 	 * - There is no RX handler.
5611 	 * - Only one packet_type matches.
5612 	 * If either of these fails, we will end up doing some per-packet
5613 	 * processing in-line, then handling the 'last ptype' for the whole
5614 	 * sublist.  This can't cause out-of-order delivery to any single ptype,
5615 	 * because the 'last ptype' must be constant across the sublist, and all
5616 	 * other ptypes are handled per-packet.
5617 	 */
5618 	/* Current (common) ptype of sublist */
5619 	struct packet_type *pt_curr = NULL;
5620 	/* Current (common) orig_dev of sublist */
5621 	struct net_device *od_curr = NULL;
5622 	struct list_head sublist;
5623 	struct sk_buff *skb, *next;
5624 
5625 	INIT_LIST_HEAD(&sublist);
5626 	list_for_each_entry_safe(skb, next, head, list) {
5627 		struct net_device *orig_dev = skb->dev;
5628 		struct packet_type *pt_prev = NULL;
5629 
5630 		skb_list_del_init(skb);
5631 		__netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5632 		if (!pt_prev)
5633 			continue;
5634 		if (pt_curr != pt_prev || od_curr != orig_dev) {
5635 			/* dispatch old sublist */
5636 			__netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5637 			/* start new sublist */
5638 			INIT_LIST_HEAD(&sublist);
5639 			pt_curr = pt_prev;
5640 			od_curr = orig_dev;
5641 		}
5642 		list_add_tail(&skb->list, &sublist);
5643 	}
5644 
5645 	/* dispatch final sublist */
5646 	__netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5647 }
5648 
__netif_receive_skb(struct sk_buff * skb)5649 static int __netif_receive_skb(struct sk_buff *skb)
5650 {
5651 	int ret;
5652 
5653 	if (sk_memalloc_socks() && skb_pfmemalloc(skb)) {
5654 		unsigned int noreclaim_flag;
5655 
5656 		/*
5657 		 * PFMEMALLOC skbs are special, they should
5658 		 * - be delivered to SOCK_MEMALLOC sockets only
5659 		 * - stay away from userspace
5660 		 * - have bounded memory usage
5661 		 *
5662 		 * Use PF_MEMALLOC as this saves us from propagating the allocation
5663 		 * context down to all allocation sites.
5664 		 */
5665 		noreclaim_flag = memalloc_noreclaim_save();
5666 		ret = __netif_receive_skb_one_core(skb, true);
5667 		memalloc_noreclaim_restore(noreclaim_flag);
5668 	} else
5669 		ret = __netif_receive_skb_one_core(skb, false);
5670 
5671 	return ret;
5672 }
5673 
__netif_receive_skb_list(struct list_head * head)5674 static void __netif_receive_skb_list(struct list_head *head)
5675 {
5676 	unsigned long noreclaim_flag = 0;
5677 	struct sk_buff *skb, *next;
5678 	bool pfmemalloc = false; /* Is current sublist PF_MEMALLOC? */
5679 
5680 	list_for_each_entry_safe(skb, next, head, list) {
5681 		if ((sk_memalloc_socks() && skb_pfmemalloc(skb)) != pfmemalloc) {
5682 			struct list_head sublist;
5683 
5684 			/* Handle the previous sublist */
5685 			list_cut_before(&sublist, head, &skb->list);
5686 			if (!list_empty(&sublist))
5687 				__netif_receive_skb_list_core(&sublist, pfmemalloc);
5688 			pfmemalloc = !pfmemalloc;
5689 			/* See comments in __netif_receive_skb */
5690 			if (pfmemalloc)
5691 				noreclaim_flag = memalloc_noreclaim_save();
5692 			else
5693 				memalloc_noreclaim_restore(noreclaim_flag);
5694 		}
5695 	}
5696 	/* Handle the remaining sublist */
5697 	if (!list_empty(head))
5698 		__netif_receive_skb_list_core(head, pfmemalloc);
5699 	/* Restore pflags */
5700 	if (pfmemalloc)
5701 		memalloc_noreclaim_restore(noreclaim_flag);
5702 }
5703 
generic_xdp_install(struct net_device * dev,struct netdev_bpf * xdp)5704 static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
5705 {
5706 	struct bpf_prog *old = rtnl_dereference(dev->xdp_prog);
5707 	struct bpf_prog *new = xdp->prog;
5708 	int ret = 0;
5709 
5710 	switch (xdp->command) {
5711 	case XDP_SETUP_PROG:
5712 		rcu_assign_pointer(dev->xdp_prog, new);
5713 		if (old)
5714 			bpf_prog_put(old);
5715 
5716 		if (old && !new) {
5717 			static_branch_dec(&generic_xdp_needed_key);
5718 		} else if (new && !old) {
5719 			static_branch_inc(&generic_xdp_needed_key);
5720 			dev_disable_lro(dev);
5721 			dev_disable_gro_hw(dev);
5722 		}
5723 		break;
5724 
5725 	default:
5726 		ret = -EINVAL;
5727 		break;
5728 	}
5729 
5730 	return ret;
5731 }
5732 
netif_receive_skb_internal(struct sk_buff * skb)5733 static int netif_receive_skb_internal(struct sk_buff *skb)
5734 {
5735 	int ret;
5736 
5737 	net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
5738 
5739 	if (skb_defer_rx_timestamp(skb))
5740 		return NET_RX_SUCCESS;
5741 
5742 	rcu_read_lock();
5743 #ifdef CONFIG_RPS
5744 	if (static_branch_unlikely(&rps_needed)) {
5745 		struct rps_dev_flow voidflow, *rflow = &voidflow;
5746 		int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5747 
5748 		if (cpu >= 0) {
5749 			ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5750 			rcu_read_unlock();
5751 			return ret;
5752 		}
5753 	}
5754 #endif
5755 	ret = __netif_receive_skb(skb);
5756 	rcu_read_unlock();
5757 	return ret;
5758 }
5759 
netif_receive_skb_list_internal(struct list_head * head)5760 void netif_receive_skb_list_internal(struct list_head *head)
5761 {
5762 	struct sk_buff *skb, *next;
5763 	struct list_head sublist;
5764 
5765 	INIT_LIST_HEAD(&sublist);
5766 	list_for_each_entry_safe(skb, next, head, list) {
5767 		net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
5768 		skb_list_del_init(skb);
5769 		if (!skb_defer_rx_timestamp(skb))
5770 			list_add_tail(&skb->list, &sublist);
5771 	}
5772 	list_splice_init(&sublist, head);
5773 
5774 	rcu_read_lock();
5775 #ifdef CONFIG_RPS
5776 	if (static_branch_unlikely(&rps_needed)) {
5777 		list_for_each_entry_safe(skb, next, head, list) {
5778 			struct rps_dev_flow voidflow, *rflow = &voidflow;
5779 			int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5780 
5781 			if (cpu >= 0) {
5782 				/* Will be handled, remove from list */
5783 				skb_list_del_init(skb);
5784 				enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5785 			}
5786 		}
5787 	}
5788 #endif
5789 	__netif_receive_skb_list(head);
5790 	rcu_read_unlock();
5791 }
5792 
5793 /**
5794  *	netif_receive_skb - process receive buffer from network
5795  *	@skb: buffer to process
5796  *
5797  *	netif_receive_skb() is the main receive data processing function.
5798  *	It always succeeds. The buffer may be dropped during processing
5799  *	for congestion control or by the protocol layers.
5800  *
5801  *	This function may only be called from softirq context and interrupts
5802  *	should be enabled.
5803  *
5804  *	Return values (usually ignored):
5805  *	NET_RX_SUCCESS: no congestion
5806  *	NET_RX_DROP: packet was dropped
5807  */
netif_receive_skb(struct sk_buff * skb)5808 int netif_receive_skb(struct sk_buff *skb)
5809 {
5810 	int ret;
5811 
5812 	trace_netif_receive_skb_entry(skb);
5813 
5814 	ret = netif_receive_skb_internal(skb);
5815 	trace_netif_receive_skb_exit(ret);
5816 
5817 	return ret;
5818 }
5819 EXPORT_SYMBOL(netif_receive_skb);
5820 
5821 /**
5822  *	netif_receive_skb_list - process many receive buffers from network
5823  *	@head: list of skbs to process.
5824  *
5825  *	Since return value of netif_receive_skb() is normally ignored, and
5826  *	wouldn't be meaningful for a list, this function returns void.
5827  *
5828  *	This function may only be called from softirq context and interrupts
5829  *	should be enabled.
5830  */
netif_receive_skb_list(struct list_head * head)5831 void netif_receive_skb_list(struct list_head *head)
5832 {
5833 	struct sk_buff *skb;
5834 
5835 	if (list_empty(head))
5836 		return;
5837 	if (trace_netif_receive_skb_list_entry_enabled()) {
5838 		list_for_each_entry(skb, head, list)
5839 			trace_netif_receive_skb_list_entry(skb);
5840 	}
5841 	netif_receive_skb_list_internal(head);
5842 	trace_netif_receive_skb_list_exit(0);
5843 }
5844 EXPORT_SYMBOL(netif_receive_skb_list);
5845 
5846 static DEFINE_PER_CPU(struct work_struct, flush_works);
5847 
5848 /* Network device is going away, flush any packets still pending */
flush_backlog(struct work_struct * work)5849 static void flush_backlog(struct work_struct *work)
5850 {
5851 	struct sk_buff *skb, *tmp;
5852 	struct softnet_data *sd;
5853 
5854 	local_bh_disable();
5855 	sd = this_cpu_ptr(&softnet_data);
5856 
5857 	rps_lock_irq_disable(sd);
5858 	skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
5859 		if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5860 			__skb_unlink(skb, &sd->input_pkt_queue);
5861 			dev_kfree_skb_irq(skb);
5862 			input_queue_head_incr(sd);
5863 		}
5864 	}
5865 	rps_unlock_irq_enable(sd);
5866 
5867 	skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
5868 		if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5869 			__skb_unlink(skb, &sd->process_queue);
5870 			kfree_skb(skb);
5871 			input_queue_head_incr(sd);
5872 		}
5873 	}
5874 	local_bh_enable();
5875 }
5876 
flush_required(int cpu)5877 static bool flush_required(int cpu)
5878 {
5879 #if IS_ENABLED(CONFIG_RPS)
5880 	struct softnet_data *sd = &per_cpu(softnet_data, cpu);
5881 	bool do_flush;
5882 
5883 	rps_lock_irq_disable(sd);
5884 
5885 	/* as insertion into process_queue happens with the rps lock held,
5886 	 * process_queue access may race only with dequeue
5887 	 */
5888 	do_flush = !skb_queue_empty(&sd->input_pkt_queue) ||
5889 		   !skb_queue_empty_lockless(&sd->process_queue);
5890 	rps_unlock_irq_enable(sd);
5891 
5892 	return do_flush;
5893 #endif
5894 	/* without RPS we can't safely check input_pkt_queue: during a
5895 	 * concurrent remote skb_queue_splice() we can detect as empty both
5896 	 * input_pkt_queue and process_queue even if the latter could end-up
5897 	 * containing a lot of packets.
5898 	 */
5899 	return true;
5900 }
5901 
flush_all_backlogs(void)5902 static void flush_all_backlogs(void)
5903 {
5904 	static cpumask_t flush_cpus;
5905 	unsigned int cpu;
5906 
5907 	/* since we are under rtnl lock protection we can use static data
5908 	 * for the cpumask and avoid allocating on stack the possibly
5909 	 * large mask
5910 	 */
5911 	ASSERT_RTNL();
5912 
5913 	cpus_read_lock();
5914 
5915 	cpumask_clear(&flush_cpus);
5916 	for_each_online_cpu(cpu) {
5917 		if (flush_required(cpu)) {
5918 			queue_work_on(cpu, system_highpri_wq,
5919 				      per_cpu_ptr(&flush_works, cpu));
5920 			cpumask_set_cpu(cpu, &flush_cpus);
5921 		}
5922 	}
5923 
5924 	/* we can have in flight packet[s] on the cpus we are not flushing,
5925 	 * synchronize_net() in unregister_netdevice_many() will take care of
5926 	 * them
5927 	 */
5928 	for_each_cpu(cpu, &flush_cpus)
5929 		flush_work(per_cpu_ptr(&flush_works, cpu));
5930 
5931 	cpus_read_unlock();
5932 }
5933 
net_rps_send_ipi(struct softnet_data * remsd)5934 static void net_rps_send_ipi(struct softnet_data *remsd)
5935 {
5936 #ifdef CONFIG_RPS
5937 	while (remsd) {
5938 		struct softnet_data *next = remsd->rps_ipi_next;
5939 
5940 		if (cpu_online(remsd->cpu))
5941 			smp_call_function_single_async(remsd->cpu, &remsd->csd);
5942 		remsd = next;
5943 	}
5944 #endif
5945 }
5946 
5947 /*
5948  * net_rps_action_and_irq_enable sends any pending IPI's for rps.
5949  * Note: called with local irq disabled, but exits with local irq enabled.
5950  */
net_rps_action_and_irq_enable(struct softnet_data * sd)5951 static void net_rps_action_and_irq_enable(struct softnet_data *sd)
5952 {
5953 #ifdef CONFIG_RPS
5954 	struct softnet_data *remsd = sd->rps_ipi_list;
5955 
5956 	if (remsd) {
5957 		sd->rps_ipi_list = NULL;
5958 
5959 		local_irq_enable();
5960 
5961 		/* Send pending IPI's to kick RPS processing on remote cpus. */
5962 		net_rps_send_ipi(remsd);
5963 	} else
5964 #endif
5965 		local_irq_enable();
5966 }
5967 
sd_has_rps_ipi_waiting(struct softnet_data * sd)5968 static bool sd_has_rps_ipi_waiting(struct softnet_data *sd)
5969 {
5970 #ifdef CONFIG_RPS
5971 	return sd->rps_ipi_list != NULL;
5972 #else
5973 	return false;
5974 #endif
5975 }
5976 
process_backlog(struct napi_struct * napi,int quota)5977 static int process_backlog(struct napi_struct *napi, int quota)
5978 {
5979 	struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
5980 	bool again = true;
5981 	int work = 0;
5982 
5983 	/* Check if we have pending ipi, its better to send them now,
5984 	 * not waiting net_rx_action() end.
5985 	 */
5986 	if (sd_has_rps_ipi_waiting(sd)) {
5987 		local_irq_disable();
5988 		net_rps_action_and_irq_enable(sd);
5989 	}
5990 
5991 	napi->weight = READ_ONCE(dev_rx_weight);
5992 	while (again) {
5993 		struct sk_buff *skb;
5994 
5995 		while ((skb = __skb_dequeue(&sd->process_queue))) {
5996 			rcu_read_lock();
5997 			__netif_receive_skb(skb);
5998 			rcu_read_unlock();
5999 			input_queue_head_incr(sd);
6000 			if (++work >= quota)
6001 				return work;
6002 
6003 		}
6004 
6005 		rps_lock_irq_disable(sd);
6006 		if (skb_queue_empty(&sd->input_pkt_queue)) {
6007 			/*
6008 			 * Inline a custom version of __napi_complete().
6009 			 * only current cpu owns and manipulates this napi,
6010 			 * and NAPI_STATE_SCHED is the only possible flag set
6011 			 * on backlog.
6012 			 * We can use a plain write instead of clear_bit(),
6013 			 * and we dont need an smp_mb() memory barrier.
6014 			 */
6015 			napi->state = 0;
6016 			again = false;
6017 		} else {
6018 			skb_queue_splice_tail_init(&sd->input_pkt_queue,
6019 						   &sd->process_queue);
6020 		}
6021 		rps_unlock_irq_enable(sd);
6022 	}
6023 
6024 	return work;
6025 }
6026 
6027 /**
6028  * __napi_schedule - schedule for receive
6029  * @n: entry to schedule
6030  *
6031  * The entry's receive function will be scheduled to run.
6032  * Consider using __napi_schedule_irqoff() if hard irqs are masked.
6033  */
__napi_schedule(struct napi_struct * n)6034 void __napi_schedule(struct napi_struct *n)
6035 {
6036 	unsigned long flags;
6037 
6038 	local_irq_save(flags);
6039 	____napi_schedule(this_cpu_ptr(&softnet_data), n);
6040 	local_irq_restore(flags);
6041 }
6042 EXPORT_SYMBOL(__napi_schedule);
6043 
6044 /**
6045  *	napi_schedule_prep - check if napi can be scheduled
6046  *	@n: napi context
6047  *
6048  * Test if NAPI routine is already running, and if not mark
6049  * it as running.  This is used as a condition variable to
6050  * insure only one NAPI poll instance runs.  We also make
6051  * sure there is no pending NAPI disable.
6052  */
napi_schedule_prep(struct napi_struct * n)6053 bool napi_schedule_prep(struct napi_struct *n)
6054 {
6055 	unsigned long new, val = READ_ONCE(n->state);
6056 
6057 	do {
6058 		if (unlikely(val & NAPIF_STATE_DISABLE))
6059 			return false;
6060 		new = val | NAPIF_STATE_SCHED;
6061 
6062 		/* Sets STATE_MISSED bit if STATE_SCHED was already set
6063 		 * This was suggested by Alexander Duyck, as compiler
6064 		 * emits better code than :
6065 		 * if (val & NAPIF_STATE_SCHED)
6066 		 *     new |= NAPIF_STATE_MISSED;
6067 		 */
6068 		new |= (val & NAPIF_STATE_SCHED) / NAPIF_STATE_SCHED *
6069 						   NAPIF_STATE_MISSED;
6070 	} while (!try_cmpxchg(&n->state, &val, new));
6071 
6072 	return !(val & NAPIF_STATE_SCHED);
6073 }
6074 EXPORT_SYMBOL(napi_schedule_prep);
6075 
6076 /**
6077  * __napi_schedule_irqoff - schedule for receive
6078  * @n: entry to schedule
6079  *
6080  * Variant of __napi_schedule() assuming hard irqs are masked.
6081  *
6082  * On PREEMPT_RT enabled kernels this maps to __napi_schedule()
6083  * because the interrupt disabled assumption might not be true
6084  * due to force-threaded interrupts and spinlock substitution.
6085  */
__napi_schedule_irqoff(struct napi_struct * n)6086 void __napi_schedule_irqoff(struct napi_struct *n)
6087 {
6088 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
6089 		____napi_schedule(this_cpu_ptr(&softnet_data), n);
6090 	else
6091 		__napi_schedule(n);
6092 }
6093 EXPORT_SYMBOL(__napi_schedule_irqoff);
6094 
napi_complete_done(struct napi_struct * n,int work_done)6095 bool napi_complete_done(struct napi_struct *n, int work_done)
6096 {
6097 	unsigned long flags, val, new, timeout = 0;
6098 	bool ret = true;
6099 
6100 	/*
6101 	 * 1) Don't let napi dequeue from the cpu poll list
6102 	 *    just in case its running on a different cpu.
6103 	 * 2) If we are busy polling, do nothing here, we have
6104 	 *    the guarantee we will be called later.
6105 	 */
6106 	if (unlikely(n->state & (NAPIF_STATE_NPSVC |
6107 				 NAPIF_STATE_IN_BUSY_POLL)))
6108 		return false;
6109 
6110 	if (work_done) {
6111 		if (n->gro_bitmask)
6112 			timeout = READ_ONCE(n->dev->gro_flush_timeout);
6113 		n->defer_hard_irqs_count = READ_ONCE(n->dev->napi_defer_hard_irqs);
6114 	}
6115 	if (n->defer_hard_irqs_count > 0) {
6116 		n->defer_hard_irqs_count--;
6117 		timeout = READ_ONCE(n->dev->gro_flush_timeout);
6118 		if (timeout)
6119 			ret = false;
6120 	}
6121 	if (n->gro_bitmask) {
6122 		/* When the NAPI instance uses a timeout and keeps postponing
6123 		 * it, we need to bound somehow the time packets are kept in
6124 		 * the GRO layer
6125 		 */
6126 		napi_gro_flush(n, !!timeout);
6127 	}
6128 
6129 	gro_normal_list(n);
6130 
6131 	if (unlikely(!list_empty(&n->poll_list))) {
6132 		/* If n->poll_list is not empty, we need to mask irqs */
6133 		local_irq_save(flags);
6134 		list_del_init(&n->poll_list);
6135 		local_irq_restore(flags);
6136 	}
6137 	WRITE_ONCE(n->list_owner, -1);
6138 
6139 	val = READ_ONCE(n->state);
6140 	do {
6141 		WARN_ON_ONCE(!(val & NAPIF_STATE_SCHED));
6142 
6143 		new = val & ~(NAPIF_STATE_MISSED | NAPIF_STATE_SCHED |
6144 			      NAPIF_STATE_SCHED_THREADED |
6145 			      NAPIF_STATE_PREFER_BUSY_POLL);
6146 
6147 		/* If STATE_MISSED was set, leave STATE_SCHED set,
6148 		 * because we will call napi->poll() one more time.
6149 		 * This C code was suggested by Alexander Duyck to help gcc.
6150 		 */
6151 		new |= (val & NAPIF_STATE_MISSED) / NAPIF_STATE_MISSED *
6152 						    NAPIF_STATE_SCHED;
6153 	} while (!try_cmpxchg(&n->state, &val, new));
6154 
6155 	if (unlikely(val & NAPIF_STATE_MISSED)) {
6156 		__napi_schedule(n);
6157 		return false;
6158 	}
6159 
6160 	if (timeout)
6161 		hrtimer_start(&n->timer, ns_to_ktime(timeout),
6162 			      HRTIMER_MODE_REL_PINNED);
6163 	return ret;
6164 }
6165 EXPORT_SYMBOL(napi_complete_done);
6166 
6167 /* must be called under rcu_read_lock(), as we dont take a reference */
napi_by_id(unsigned int napi_id)6168 static struct napi_struct *napi_by_id(unsigned int napi_id)
6169 {
6170 	unsigned int hash = napi_id % HASH_SIZE(napi_hash);
6171 	struct napi_struct *napi;
6172 
6173 	hlist_for_each_entry_rcu(napi, &napi_hash[hash], napi_hash_node)
6174 		if (napi->napi_id == napi_id)
6175 			return napi;
6176 
6177 	return NULL;
6178 }
6179 
6180 #if defined(CONFIG_NET_RX_BUSY_POLL)
6181 
__busy_poll_stop(struct napi_struct * napi,bool skip_schedule)6182 static void __busy_poll_stop(struct napi_struct *napi, bool skip_schedule)
6183 {
6184 	if (!skip_schedule) {
6185 		gro_normal_list(napi);
6186 		__napi_schedule(napi);
6187 		return;
6188 	}
6189 
6190 	if (napi->gro_bitmask) {
6191 		/* flush too old packets
6192 		 * If HZ < 1000, flush all packets.
6193 		 */
6194 		napi_gro_flush(napi, HZ >= 1000);
6195 	}
6196 
6197 	gro_normal_list(napi);
6198 	clear_bit(NAPI_STATE_SCHED, &napi->state);
6199 }
6200 
busy_poll_stop(struct napi_struct * napi,void * have_poll_lock,bool prefer_busy_poll,u16 budget)6201 static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool prefer_busy_poll,
6202 			   u16 budget)
6203 {
6204 	bool skip_schedule = false;
6205 	unsigned long timeout;
6206 	int rc;
6207 
6208 	/* Busy polling means there is a high chance device driver hard irq
6209 	 * could not grab NAPI_STATE_SCHED, and that NAPI_STATE_MISSED was
6210 	 * set in napi_schedule_prep().
6211 	 * Since we are about to call napi->poll() once more, we can safely
6212 	 * clear NAPI_STATE_MISSED.
6213 	 *
6214 	 * Note: x86 could use a single "lock and ..." instruction
6215 	 * to perform these two clear_bit()
6216 	 */
6217 	clear_bit(NAPI_STATE_MISSED, &napi->state);
6218 	clear_bit(NAPI_STATE_IN_BUSY_POLL, &napi->state);
6219 
6220 	local_bh_disable();
6221 
6222 	if (prefer_busy_poll) {
6223 		napi->defer_hard_irqs_count = READ_ONCE(napi->dev->napi_defer_hard_irqs);
6224 		timeout = READ_ONCE(napi->dev->gro_flush_timeout);
6225 		if (napi->defer_hard_irqs_count && timeout) {
6226 			hrtimer_start(&napi->timer, ns_to_ktime(timeout), HRTIMER_MODE_REL_PINNED);
6227 			skip_schedule = true;
6228 		}
6229 	}
6230 
6231 	/* All we really want here is to re-enable device interrupts.
6232 	 * Ideally, a new ndo_busy_poll_stop() could avoid another round.
6233 	 */
6234 	rc = napi->poll(napi, budget);
6235 	/* We can't gro_normal_list() here, because napi->poll() might have
6236 	 * rearmed the napi (napi_complete_done()) in which case it could
6237 	 * already be running on another CPU.
6238 	 */
6239 	trace_napi_poll(napi, rc, budget);
6240 	netpoll_poll_unlock(have_poll_lock);
6241 	if (rc == budget)
6242 		__busy_poll_stop(napi, skip_schedule);
6243 	local_bh_enable();
6244 }
6245 
napi_busy_loop(unsigned int napi_id,bool (* loop_end)(void *,unsigned long),void * loop_end_arg,bool prefer_busy_poll,u16 budget)6246 void napi_busy_loop(unsigned int napi_id,
6247 		    bool (*loop_end)(void *, unsigned long),
6248 		    void *loop_end_arg, bool prefer_busy_poll, u16 budget)
6249 {
6250 	unsigned long start_time = loop_end ? busy_loop_current_time() : 0;
6251 	int (*napi_poll)(struct napi_struct *napi, int budget);
6252 	void *have_poll_lock = NULL;
6253 	struct napi_struct *napi;
6254 
6255 restart:
6256 	napi_poll = NULL;
6257 
6258 	rcu_read_lock();
6259 
6260 	napi = napi_by_id(napi_id);
6261 	if (!napi)
6262 		goto out;
6263 
6264 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
6265 		preempt_disable();
6266 	for (;;) {
6267 		int work = 0;
6268 
6269 		local_bh_disable();
6270 		if (!napi_poll) {
6271 			unsigned long val = READ_ONCE(napi->state);
6272 
6273 			/* If multiple threads are competing for this napi,
6274 			 * we avoid dirtying napi->state as much as we can.
6275 			 */
6276 			if (val & (NAPIF_STATE_DISABLE | NAPIF_STATE_SCHED |
6277 				   NAPIF_STATE_IN_BUSY_POLL)) {
6278 				if (prefer_busy_poll)
6279 					set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6280 				goto count;
6281 			}
6282 			if (cmpxchg(&napi->state, val,
6283 				    val | NAPIF_STATE_IN_BUSY_POLL |
6284 					  NAPIF_STATE_SCHED) != val) {
6285 				if (prefer_busy_poll)
6286 					set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6287 				goto count;
6288 			}
6289 			have_poll_lock = netpoll_poll_lock(napi);
6290 			napi_poll = napi->poll;
6291 		}
6292 		work = napi_poll(napi, budget);
6293 		trace_napi_poll(napi, work, budget);
6294 		gro_normal_list(napi);
6295 count:
6296 		if (work > 0)
6297 			__NET_ADD_STATS(dev_net(napi->dev),
6298 					LINUX_MIB_BUSYPOLLRXPACKETS, work);
6299 		local_bh_enable();
6300 
6301 		if (!loop_end || loop_end(loop_end_arg, start_time))
6302 			break;
6303 
6304 		if (unlikely(need_resched())) {
6305 			if (napi_poll)
6306 				busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
6307 			if (!IS_ENABLED(CONFIG_PREEMPT_RT))
6308 				preempt_enable();
6309 			rcu_read_unlock();
6310 			cond_resched();
6311 			if (loop_end(loop_end_arg, start_time))
6312 				return;
6313 			goto restart;
6314 		}
6315 		cpu_relax();
6316 	}
6317 	if (napi_poll)
6318 		busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
6319 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
6320 		preempt_enable();
6321 out:
6322 	rcu_read_unlock();
6323 }
6324 EXPORT_SYMBOL(napi_busy_loop);
6325 
6326 #endif /* CONFIG_NET_RX_BUSY_POLL */
6327 
napi_hash_add(struct napi_struct * napi)6328 static void napi_hash_add(struct napi_struct *napi)
6329 {
6330 	if (test_bit(NAPI_STATE_NO_BUSY_POLL, &napi->state))
6331 		return;
6332 
6333 	spin_lock(&napi_hash_lock);
6334 
6335 	/* 0..NR_CPUS range is reserved for sender_cpu use */
6336 	do {
6337 		if (unlikely(++napi_gen_id < MIN_NAPI_ID))
6338 			napi_gen_id = MIN_NAPI_ID;
6339 	} while (napi_by_id(napi_gen_id));
6340 	napi->napi_id = napi_gen_id;
6341 
6342 	hlist_add_head_rcu(&napi->napi_hash_node,
6343 			   &napi_hash[napi->napi_id % HASH_SIZE(napi_hash)]);
6344 
6345 	spin_unlock(&napi_hash_lock);
6346 }
6347 
6348 /* Warning : caller is responsible to make sure rcu grace period
6349  * is respected before freeing memory containing @napi
6350  */
napi_hash_del(struct napi_struct * napi)6351 static void napi_hash_del(struct napi_struct *napi)
6352 {
6353 	spin_lock(&napi_hash_lock);
6354 
6355 	hlist_del_init_rcu(&napi->napi_hash_node);
6356 
6357 	spin_unlock(&napi_hash_lock);
6358 }
6359 
napi_watchdog(struct hrtimer * timer)6360 static enum hrtimer_restart napi_watchdog(struct hrtimer *timer)
6361 {
6362 	struct napi_struct *napi;
6363 
6364 	napi = container_of(timer, struct napi_struct, timer);
6365 
6366 	/* Note : we use a relaxed variant of napi_schedule_prep() not setting
6367 	 * NAPI_STATE_MISSED, since we do not react to a device IRQ.
6368 	 */
6369 	if (!napi_disable_pending(napi) &&
6370 	    !test_and_set_bit(NAPI_STATE_SCHED, &napi->state)) {
6371 		clear_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6372 		__napi_schedule_irqoff(napi);
6373 	}
6374 
6375 	return HRTIMER_NORESTART;
6376 }
6377 
init_gro_hash(struct napi_struct * napi)6378 static void init_gro_hash(struct napi_struct *napi)
6379 {
6380 	int i;
6381 
6382 	for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6383 		INIT_LIST_HEAD(&napi->gro_hash[i].list);
6384 		napi->gro_hash[i].count = 0;
6385 	}
6386 	napi->gro_bitmask = 0;
6387 }
6388 
dev_set_threaded(struct net_device * dev,bool threaded)6389 int dev_set_threaded(struct net_device *dev, bool threaded)
6390 {
6391 	struct napi_struct *napi;
6392 	int err = 0;
6393 
6394 	if (dev->threaded == threaded)
6395 		return 0;
6396 
6397 	if (threaded) {
6398 		list_for_each_entry(napi, &dev->napi_list, dev_list) {
6399 			if (!napi->thread) {
6400 				err = napi_kthread_create(napi);
6401 				if (err) {
6402 					threaded = false;
6403 					break;
6404 				}
6405 			}
6406 		}
6407 	}
6408 
6409 	dev->threaded = threaded;
6410 
6411 	/* Make sure kthread is created before THREADED bit
6412 	 * is set.
6413 	 */
6414 	smp_mb__before_atomic();
6415 
6416 	/* Setting/unsetting threaded mode on a napi might not immediately
6417 	 * take effect, if the current napi instance is actively being
6418 	 * polled. In this case, the switch between threaded mode and
6419 	 * softirq mode will happen in the next round of napi_schedule().
6420 	 * This should not cause hiccups/stalls to the live traffic.
6421 	 */
6422 	list_for_each_entry(napi, &dev->napi_list, dev_list)
6423 		assign_bit(NAPI_STATE_THREADED, &napi->state, threaded);
6424 
6425 	return err;
6426 }
6427 EXPORT_SYMBOL(dev_set_threaded);
6428 
netif_napi_add_weight(struct net_device * dev,struct napi_struct * napi,int (* poll)(struct napi_struct *,int),int weight)6429 void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi,
6430 			   int (*poll)(struct napi_struct *, int), int weight)
6431 {
6432 	if (WARN_ON(test_and_set_bit(NAPI_STATE_LISTED, &napi->state)))
6433 		return;
6434 
6435 	INIT_LIST_HEAD(&napi->poll_list);
6436 	INIT_HLIST_NODE(&napi->napi_hash_node);
6437 	hrtimer_init(&napi->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
6438 	napi->timer.function = napi_watchdog;
6439 	init_gro_hash(napi);
6440 	napi->skb = NULL;
6441 	INIT_LIST_HEAD(&napi->rx_list);
6442 	napi->rx_count = 0;
6443 	napi->poll = poll;
6444 	if (weight > NAPI_POLL_WEIGHT)
6445 		netdev_err_once(dev, "%s() called with weight %d\n", __func__,
6446 				weight);
6447 	napi->weight = weight;
6448 	napi->dev = dev;
6449 #ifdef CONFIG_NETPOLL
6450 	napi->poll_owner = -1;
6451 #endif
6452 	napi->list_owner = -1;
6453 	set_bit(NAPI_STATE_SCHED, &napi->state);
6454 	set_bit(NAPI_STATE_NPSVC, &napi->state);
6455 	list_add_rcu(&napi->dev_list, &dev->napi_list);
6456 	napi_hash_add(napi);
6457 	napi_get_frags_check(napi);
6458 	/* Create kthread for this napi if dev->threaded is set.
6459 	 * Clear dev->threaded if kthread creation failed so that
6460 	 * threaded mode will not be enabled in napi_enable().
6461 	 */
6462 	if (dev->threaded && napi_kthread_create(napi))
6463 		dev->threaded = 0;
6464 }
6465 EXPORT_SYMBOL(netif_napi_add_weight);
6466 
napi_disable(struct napi_struct * n)6467 void napi_disable(struct napi_struct *n)
6468 {
6469 	unsigned long val, new;
6470 
6471 	might_sleep();
6472 	set_bit(NAPI_STATE_DISABLE, &n->state);
6473 
6474 	val = READ_ONCE(n->state);
6475 	do {
6476 		while (val & (NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC)) {
6477 			usleep_range(20, 200);
6478 			val = READ_ONCE(n->state);
6479 		}
6480 
6481 		new = val | NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC;
6482 		new &= ~(NAPIF_STATE_THREADED | NAPIF_STATE_PREFER_BUSY_POLL);
6483 	} while (!try_cmpxchg(&n->state, &val, new));
6484 
6485 	hrtimer_cancel(&n->timer);
6486 
6487 	clear_bit(NAPI_STATE_DISABLE, &n->state);
6488 }
6489 EXPORT_SYMBOL(napi_disable);
6490 
6491 /**
6492  *	napi_enable - enable NAPI scheduling
6493  *	@n: NAPI context
6494  *
6495  * Resume NAPI from being scheduled on this context.
6496  * Must be paired with napi_disable.
6497  */
napi_enable(struct napi_struct * n)6498 void napi_enable(struct napi_struct *n)
6499 {
6500 	unsigned long new, val = READ_ONCE(n->state);
6501 
6502 	do {
6503 		BUG_ON(!test_bit(NAPI_STATE_SCHED, &val));
6504 
6505 		new = val & ~(NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC);
6506 		if (n->dev->threaded && n->thread)
6507 			new |= NAPIF_STATE_THREADED;
6508 	} while (!try_cmpxchg(&n->state, &val, new));
6509 }
6510 EXPORT_SYMBOL(napi_enable);
6511 
flush_gro_hash(struct napi_struct * napi)6512 static void flush_gro_hash(struct napi_struct *napi)
6513 {
6514 	int i;
6515 
6516 	for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6517 		struct sk_buff *skb, *n;
6518 
6519 		list_for_each_entry_safe(skb, n, &napi->gro_hash[i].list, list)
6520 			kfree_skb(skb);
6521 		napi->gro_hash[i].count = 0;
6522 	}
6523 }
6524 
6525 /* Must be called in process context */
__netif_napi_del(struct napi_struct * napi)6526 void __netif_napi_del(struct napi_struct *napi)
6527 {
6528 	if (!test_and_clear_bit(NAPI_STATE_LISTED, &napi->state))
6529 		return;
6530 
6531 	napi_hash_del(napi);
6532 	list_del_rcu(&napi->dev_list);
6533 	napi_free_frags(napi);
6534 
6535 	flush_gro_hash(napi);
6536 	napi->gro_bitmask = 0;
6537 
6538 	if (napi->thread) {
6539 		kthread_stop(napi->thread);
6540 		napi->thread = NULL;
6541 	}
6542 }
6543 EXPORT_SYMBOL(__netif_napi_del);
6544 
__napi_poll(struct napi_struct * n,bool * repoll)6545 static int __napi_poll(struct napi_struct *n, bool *repoll)
6546 {
6547 	int work, weight;
6548 
6549 	weight = n->weight;
6550 
6551 	/* This NAPI_STATE_SCHED test is for avoiding a race
6552 	 * with netpoll's poll_napi().  Only the entity which
6553 	 * obtains the lock and sees NAPI_STATE_SCHED set will
6554 	 * actually make the ->poll() call.  Therefore we avoid
6555 	 * accidentally calling ->poll() when NAPI is not scheduled.
6556 	 */
6557 	work = 0;
6558 	if (test_bit(NAPI_STATE_SCHED, &n->state)) {
6559 		work = n->poll(n, weight);
6560 		trace_napi_poll(n, work, weight);
6561 	}
6562 
6563 	if (unlikely(work > weight))
6564 		netdev_err_once(n->dev, "NAPI poll function %pS returned %d, exceeding its budget of %d.\n",
6565 				n->poll, work, weight);
6566 
6567 	if (likely(work < weight))
6568 		return work;
6569 
6570 	/* Drivers must not modify the NAPI state if they
6571 	 * consume the entire weight.  In such cases this code
6572 	 * still "owns" the NAPI instance and therefore can
6573 	 * move the instance around on the list at-will.
6574 	 */
6575 	if (unlikely(napi_disable_pending(n))) {
6576 		napi_complete(n);
6577 		return work;
6578 	}
6579 
6580 	/* The NAPI context has more processing work, but busy-polling
6581 	 * is preferred. Exit early.
6582 	 */
6583 	if (napi_prefer_busy_poll(n)) {
6584 		if (napi_complete_done(n, work)) {
6585 			/* If timeout is not set, we need to make sure
6586 			 * that the NAPI is re-scheduled.
6587 			 */
6588 			napi_schedule(n);
6589 		}
6590 		return work;
6591 	}
6592 
6593 	if (n->gro_bitmask) {
6594 		/* flush too old packets
6595 		 * If HZ < 1000, flush all packets.
6596 		 */
6597 		napi_gro_flush(n, HZ >= 1000);
6598 	}
6599 
6600 	gro_normal_list(n);
6601 
6602 	/* Some drivers may have called napi_schedule
6603 	 * prior to exhausting their budget.
6604 	 */
6605 	if (unlikely(!list_empty(&n->poll_list))) {
6606 		pr_warn_once("%s: Budget exhausted after napi rescheduled\n",
6607 			     n->dev ? n->dev->name : "backlog");
6608 		return work;
6609 	}
6610 
6611 	*repoll = true;
6612 
6613 	return work;
6614 }
6615 
napi_poll(struct napi_struct * n,struct list_head * repoll)6616 static int napi_poll(struct napi_struct *n, struct list_head *repoll)
6617 {
6618 	bool do_repoll = false;
6619 	void *have;
6620 	int work;
6621 
6622 	list_del_init(&n->poll_list);
6623 
6624 	have = netpoll_poll_lock(n);
6625 
6626 	work = __napi_poll(n, &do_repoll);
6627 
6628 	if (do_repoll)
6629 		list_add_tail(&n->poll_list, repoll);
6630 
6631 	netpoll_poll_unlock(have);
6632 
6633 	return work;
6634 }
6635 
napi_thread_wait(struct napi_struct * napi)6636 static int napi_thread_wait(struct napi_struct *napi)
6637 {
6638 	bool woken = false;
6639 
6640 	set_current_state(TASK_INTERRUPTIBLE);
6641 
6642 	while (!kthread_should_stop()) {
6643 		/* Testing SCHED_THREADED bit here to make sure the current
6644 		 * kthread owns this napi and could poll on this napi.
6645 		 * Testing SCHED bit is not enough because SCHED bit might be
6646 		 * set by some other busy poll thread or by napi_disable().
6647 		 */
6648 		if (test_bit(NAPI_STATE_SCHED_THREADED, &napi->state) || woken) {
6649 			WARN_ON(!list_empty(&napi->poll_list));
6650 			__set_current_state(TASK_RUNNING);
6651 			return 0;
6652 		}
6653 
6654 		schedule();
6655 		/* woken being true indicates this thread owns this napi. */
6656 		woken = true;
6657 		set_current_state(TASK_INTERRUPTIBLE);
6658 	}
6659 	__set_current_state(TASK_RUNNING);
6660 
6661 	return -1;
6662 }
6663 
skb_defer_free_flush(struct softnet_data * sd)6664 static void skb_defer_free_flush(struct softnet_data *sd)
6665 {
6666 	struct sk_buff *skb, *next;
6667 
6668 	/* Paired with WRITE_ONCE() in skb_attempt_defer_free() */
6669 	if (!READ_ONCE(sd->defer_list))
6670 		return;
6671 
6672 	spin_lock(&sd->defer_lock);
6673 	skb = sd->defer_list;
6674 	sd->defer_list = NULL;
6675 	sd->defer_count = 0;
6676 	spin_unlock(&sd->defer_lock);
6677 
6678 	while (skb != NULL) {
6679 		next = skb->next;
6680 		napi_consume_skb(skb, 1);
6681 		skb = next;
6682 	}
6683 }
6684 
napi_threaded_poll(void * data)6685 static int napi_threaded_poll(void *data)
6686 {
6687 	struct napi_struct *napi = data;
6688 	struct softnet_data *sd;
6689 	void *have;
6690 
6691 	while (!napi_thread_wait(napi)) {
6692 		for (;;) {
6693 			bool repoll = false;
6694 
6695 			local_bh_disable();
6696 			sd = this_cpu_ptr(&softnet_data);
6697 			sd->in_napi_threaded_poll = true;
6698 
6699 			have = netpoll_poll_lock(napi);
6700 			__napi_poll(napi, &repoll);
6701 			netpoll_poll_unlock(have);
6702 
6703 			sd->in_napi_threaded_poll = false;
6704 			barrier();
6705 
6706 			if (sd_has_rps_ipi_waiting(sd)) {
6707 				local_irq_disable();
6708 				net_rps_action_and_irq_enable(sd);
6709 			}
6710 			skb_defer_free_flush(sd);
6711 			local_bh_enable();
6712 
6713 			if (!repoll)
6714 				break;
6715 
6716 			cond_resched();
6717 		}
6718 	}
6719 	return 0;
6720 }
6721 
net_rx_action(struct softirq_action * h)6722 static __latent_entropy void net_rx_action(struct softirq_action *h)
6723 {
6724 	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
6725 	unsigned long time_limit = jiffies +
6726 		usecs_to_jiffies(READ_ONCE(netdev_budget_usecs));
6727 	int budget = READ_ONCE(netdev_budget);
6728 	LIST_HEAD(list);
6729 	LIST_HEAD(repoll);
6730 
6731 start:
6732 	sd->in_net_rx_action = true;
6733 	local_irq_disable();
6734 	list_splice_init(&sd->poll_list, &list);
6735 	local_irq_enable();
6736 
6737 	for (;;) {
6738 		struct napi_struct *n;
6739 
6740 		skb_defer_free_flush(sd);
6741 
6742 		if (list_empty(&list)) {
6743 			if (list_empty(&repoll)) {
6744 				sd->in_net_rx_action = false;
6745 				barrier();
6746 				/* We need to check if ____napi_schedule()
6747 				 * had refilled poll_list while
6748 				 * sd->in_net_rx_action was true.
6749 				 */
6750 				if (!list_empty(&sd->poll_list))
6751 					goto start;
6752 				if (!sd_has_rps_ipi_waiting(sd))
6753 					goto end;
6754 			}
6755 			break;
6756 		}
6757 
6758 		n = list_first_entry(&list, struct napi_struct, poll_list);
6759 		budget -= napi_poll(n, &repoll);
6760 
6761 		/* If softirq window is exhausted then punt.
6762 		 * Allow this to run for 2 jiffies since which will allow
6763 		 * an average latency of 1.5/HZ.
6764 		 */
6765 		if (unlikely(budget <= 0 ||
6766 			     time_after_eq(jiffies, time_limit))) {
6767 			sd->time_squeeze++;
6768 			break;
6769 		}
6770 	}
6771 
6772 	local_irq_disable();
6773 
6774 	list_splice_tail_init(&sd->poll_list, &list);
6775 	list_splice_tail(&repoll, &list);
6776 	list_splice(&list, &sd->poll_list);
6777 	if (!list_empty(&sd->poll_list))
6778 		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
6779 	else
6780 		sd->in_net_rx_action = false;
6781 
6782 	net_rps_action_and_irq_enable(sd);
6783 end:;
6784 }
6785 
6786 struct netdev_adjacent {
6787 	struct net_device *dev;
6788 	netdevice_tracker dev_tracker;
6789 
6790 	/* upper master flag, there can only be one master device per list */
6791 	bool master;
6792 
6793 	/* lookup ignore flag */
6794 	bool ignore;
6795 
6796 	/* counter for the number of times this device was added to us */
6797 	u16 ref_nr;
6798 
6799 	/* private field for the users */
6800 	void *private;
6801 
6802 	struct list_head list;
6803 	struct rcu_head rcu;
6804 };
6805 
__netdev_find_adj(struct net_device * adj_dev,struct list_head * adj_list)6806 static struct netdev_adjacent *__netdev_find_adj(struct net_device *adj_dev,
6807 						 struct list_head *adj_list)
6808 {
6809 	struct netdev_adjacent *adj;
6810 
6811 	list_for_each_entry(adj, adj_list, list) {
6812 		if (adj->dev == adj_dev)
6813 			return adj;
6814 	}
6815 	return NULL;
6816 }
6817 
____netdev_has_upper_dev(struct net_device * upper_dev,struct netdev_nested_priv * priv)6818 static int ____netdev_has_upper_dev(struct net_device *upper_dev,
6819 				    struct netdev_nested_priv *priv)
6820 {
6821 	struct net_device *dev = (struct net_device *)priv->data;
6822 
6823 	return upper_dev == dev;
6824 }
6825 
6826 /**
6827  * netdev_has_upper_dev - Check if device is linked to an upper device
6828  * @dev: device
6829  * @upper_dev: upper device to check
6830  *
6831  * Find out if a device is linked to specified upper device and return true
6832  * in case it is. Note that this checks only immediate upper device,
6833  * not through a complete stack of devices. The caller must hold the RTNL lock.
6834  */
netdev_has_upper_dev(struct net_device * dev,struct net_device * upper_dev)6835 bool netdev_has_upper_dev(struct net_device *dev,
6836 			  struct net_device *upper_dev)
6837 {
6838 	struct netdev_nested_priv priv = {
6839 		.data = (void *)upper_dev,
6840 	};
6841 
6842 	ASSERT_RTNL();
6843 
6844 	return netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
6845 					     &priv);
6846 }
6847 EXPORT_SYMBOL(netdev_has_upper_dev);
6848 
6849 /**
6850  * netdev_has_upper_dev_all_rcu - Check if device is linked to an upper device
6851  * @dev: device
6852  * @upper_dev: upper device to check
6853  *
6854  * Find out if a device is linked to specified upper device and return true
6855  * in case it is. Note that this checks the entire upper device chain.
6856  * The caller must hold rcu lock.
6857  */
6858 
netdev_has_upper_dev_all_rcu(struct net_device * dev,struct net_device * upper_dev)6859 bool netdev_has_upper_dev_all_rcu(struct net_device *dev,
6860 				  struct net_device *upper_dev)
6861 {
6862 	struct netdev_nested_priv priv = {
6863 		.data = (void *)upper_dev,
6864 	};
6865 
6866 	return !!netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
6867 					       &priv);
6868 }
6869 EXPORT_SYMBOL(netdev_has_upper_dev_all_rcu);
6870 
6871 /**
6872  * netdev_has_any_upper_dev - Check if device is linked to some device
6873  * @dev: device
6874  *
6875  * Find out if a device is linked to an upper device and return true in case
6876  * it is. The caller must hold the RTNL lock.
6877  */
netdev_has_any_upper_dev(struct net_device * dev)6878 bool netdev_has_any_upper_dev(struct net_device *dev)
6879 {
6880 	ASSERT_RTNL();
6881 
6882 	return !list_empty(&dev->adj_list.upper);
6883 }
6884 EXPORT_SYMBOL(netdev_has_any_upper_dev);
6885 
6886 /**
6887  * netdev_master_upper_dev_get - Get master upper device
6888  * @dev: device
6889  *
6890  * Find a master upper device and return pointer to it or NULL in case
6891  * it's not there. The caller must hold the RTNL lock.
6892  */
netdev_master_upper_dev_get(struct net_device * dev)6893 struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
6894 {
6895 	struct netdev_adjacent *upper;
6896 
6897 	ASSERT_RTNL();
6898 
6899 	if (list_empty(&dev->adj_list.upper))
6900 		return NULL;
6901 
6902 	upper = list_first_entry(&dev->adj_list.upper,
6903 				 struct netdev_adjacent, list);
6904 	if (likely(upper->master))
6905 		return upper->dev;
6906 	return NULL;
6907 }
6908 EXPORT_SYMBOL(netdev_master_upper_dev_get);
6909 
__netdev_master_upper_dev_get(struct net_device * dev)6910 static struct net_device *__netdev_master_upper_dev_get(struct net_device *dev)
6911 {
6912 	struct netdev_adjacent *upper;
6913 
6914 	ASSERT_RTNL();
6915 
6916 	if (list_empty(&dev->adj_list.upper))
6917 		return NULL;
6918 
6919 	upper = list_first_entry(&dev->adj_list.upper,
6920 				 struct netdev_adjacent, list);
6921 	if (likely(upper->master) && !upper->ignore)
6922 		return upper->dev;
6923 	return NULL;
6924 }
6925 
6926 /**
6927  * netdev_has_any_lower_dev - Check if device is linked to some device
6928  * @dev: device
6929  *
6930  * Find out if a device is linked to a lower device and return true in case
6931  * it is. The caller must hold the RTNL lock.
6932  */
netdev_has_any_lower_dev(struct net_device * dev)6933 static bool netdev_has_any_lower_dev(struct net_device *dev)
6934 {
6935 	ASSERT_RTNL();
6936 
6937 	return !list_empty(&dev->adj_list.lower);
6938 }
6939 
netdev_adjacent_get_private(struct list_head * adj_list)6940 void *netdev_adjacent_get_private(struct list_head *adj_list)
6941 {
6942 	struct netdev_adjacent *adj;
6943 
6944 	adj = list_entry(adj_list, struct netdev_adjacent, list);
6945 
6946 	return adj->private;
6947 }
6948 EXPORT_SYMBOL(netdev_adjacent_get_private);
6949 
6950 /**
6951  * netdev_upper_get_next_dev_rcu - Get the next dev from upper list
6952  * @dev: device
6953  * @iter: list_head ** of the current position
6954  *
6955  * Gets the next device from the dev's upper list, starting from iter
6956  * position. The caller must hold RCU read lock.
6957  */
netdev_upper_get_next_dev_rcu(struct net_device * dev,struct list_head ** iter)6958 struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,
6959 						 struct list_head **iter)
6960 {
6961 	struct netdev_adjacent *upper;
6962 
6963 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
6964 
6965 	upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
6966 
6967 	if (&upper->list == &dev->adj_list.upper)
6968 		return NULL;
6969 
6970 	*iter = &upper->list;
6971 
6972 	return upper->dev;
6973 }
6974 EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu);
6975 
__netdev_next_upper_dev(struct net_device * dev,struct list_head ** iter,bool * ignore)6976 static struct net_device *__netdev_next_upper_dev(struct net_device *dev,
6977 						  struct list_head **iter,
6978 						  bool *ignore)
6979 {
6980 	struct netdev_adjacent *upper;
6981 
6982 	upper = list_entry((*iter)->next, struct netdev_adjacent, list);
6983 
6984 	if (&upper->list == &dev->adj_list.upper)
6985 		return NULL;
6986 
6987 	*iter = &upper->list;
6988 	*ignore = upper->ignore;
6989 
6990 	return upper->dev;
6991 }
6992 
netdev_next_upper_dev_rcu(struct net_device * dev,struct list_head ** iter)6993 static struct net_device *netdev_next_upper_dev_rcu(struct net_device *dev,
6994 						    struct list_head **iter)
6995 {
6996 	struct netdev_adjacent *upper;
6997 
6998 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
6999 
7000 	upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7001 
7002 	if (&upper->list == &dev->adj_list.upper)
7003 		return NULL;
7004 
7005 	*iter = &upper->list;
7006 
7007 	return upper->dev;
7008 }
7009 
__netdev_walk_all_upper_dev(struct net_device * dev,int (* fn)(struct net_device * dev,struct netdev_nested_priv * priv),struct netdev_nested_priv * priv)7010 static int __netdev_walk_all_upper_dev(struct net_device *dev,
7011 				       int (*fn)(struct net_device *dev,
7012 					 struct netdev_nested_priv *priv),
7013 				       struct netdev_nested_priv *priv)
7014 {
7015 	struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7016 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7017 	int ret, cur = 0;
7018 	bool ignore;
7019 
7020 	now = dev;
7021 	iter = &dev->adj_list.upper;
7022 
7023 	while (1) {
7024 		if (now != dev) {
7025 			ret = fn(now, priv);
7026 			if (ret)
7027 				return ret;
7028 		}
7029 
7030 		next = NULL;
7031 		while (1) {
7032 			udev = __netdev_next_upper_dev(now, &iter, &ignore);
7033 			if (!udev)
7034 				break;
7035 			if (ignore)
7036 				continue;
7037 
7038 			next = udev;
7039 			niter = &udev->adj_list.upper;
7040 			dev_stack[cur] = now;
7041 			iter_stack[cur++] = iter;
7042 			break;
7043 		}
7044 
7045 		if (!next) {
7046 			if (!cur)
7047 				return 0;
7048 			next = dev_stack[--cur];
7049 			niter = iter_stack[cur];
7050 		}
7051 
7052 		now = next;
7053 		iter = niter;
7054 	}
7055 
7056 	return 0;
7057 }
7058 
netdev_walk_all_upper_dev_rcu(struct net_device * dev,int (* fn)(struct net_device * dev,struct netdev_nested_priv * priv),struct netdev_nested_priv * priv)7059 int netdev_walk_all_upper_dev_rcu(struct net_device *dev,
7060 				  int (*fn)(struct net_device *dev,
7061 					    struct netdev_nested_priv *priv),
7062 				  struct netdev_nested_priv *priv)
7063 {
7064 	struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7065 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7066 	int ret, cur = 0;
7067 
7068 	now = dev;
7069 	iter = &dev->adj_list.upper;
7070 
7071 	while (1) {
7072 		if (now != dev) {
7073 			ret = fn(now, priv);
7074 			if (ret)
7075 				return ret;
7076 		}
7077 
7078 		next = NULL;
7079 		while (1) {
7080 			udev = netdev_next_upper_dev_rcu(now, &iter);
7081 			if (!udev)
7082 				break;
7083 
7084 			next = udev;
7085 			niter = &udev->adj_list.upper;
7086 			dev_stack[cur] = now;
7087 			iter_stack[cur++] = iter;
7088 			break;
7089 		}
7090 
7091 		if (!next) {
7092 			if (!cur)
7093 				return 0;
7094 			next = dev_stack[--cur];
7095 			niter = iter_stack[cur];
7096 		}
7097 
7098 		now = next;
7099 		iter = niter;
7100 	}
7101 
7102 	return 0;
7103 }
7104 EXPORT_SYMBOL_GPL(netdev_walk_all_upper_dev_rcu);
7105 
__netdev_has_upper_dev(struct net_device * dev,struct net_device * upper_dev)7106 static bool __netdev_has_upper_dev(struct net_device *dev,
7107 				   struct net_device *upper_dev)
7108 {
7109 	struct netdev_nested_priv priv = {
7110 		.flags = 0,
7111 		.data = (void *)upper_dev,
7112 	};
7113 
7114 	ASSERT_RTNL();
7115 
7116 	return __netdev_walk_all_upper_dev(dev, ____netdev_has_upper_dev,
7117 					   &priv);
7118 }
7119 
7120 /**
7121  * netdev_lower_get_next_private - Get the next ->private from the
7122  *				   lower neighbour list
7123  * @dev: device
7124  * @iter: list_head ** of the current position
7125  *
7126  * Gets the next netdev_adjacent->private from the dev's lower neighbour
7127  * list, starting from iter position. The caller must hold either hold the
7128  * RTNL lock or its own locking that guarantees that the neighbour lower
7129  * list will remain unchanged.
7130  */
netdev_lower_get_next_private(struct net_device * dev,struct list_head ** iter)7131 void *netdev_lower_get_next_private(struct net_device *dev,
7132 				    struct list_head **iter)
7133 {
7134 	struct netdev_adjacent *lower;
7135 
7136 	lower = list_entry(*iter, struct netdev_adjacent, list);
7137 
7138 	if (&lower->list == &dev->adj_list.lower)
7139 		return NULL;
7140 
7141 	*iter = lower->list.next;
7142 
7143 	return lower->private;
7144 }
7145 EXPORT_SYMBOL(netdev_lower_get_next_private);
7146 
7147 /**
7148  * netdev_lower_get_next_private_rcu - Get the next ->private from the
7149  *				       lower neighbour list, RCU
7150  *				       variant
7151  * @dev: device
7152  * @iter: list_head ** of the current position
7153  *
7154  * Gets the next netdev_adjacent->private from the dev's lower neighbour
7155  * list, starting from iter position. The caller must hold RCU read lock.
7156  */
netdev_lower_get_next_private_rcu(struct net_device * dev,struct list_head ** iter)7157 void *netdev_lower_get_next_private_rcu(struct net_device *dev,
7158 					struct list_head **iter)
7159 {
7160 	struct netdev_adjacent *lower;
7161 
7162 	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
7163 
7164 	lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7165 
7166 	if (&lower->list == &dev->adj_list.lower)
7167 		return NULL;
7168 
7169 	*iter = &lower->list;
7170 
7171 	return lower->private;
7172 }
7173 EXPORT_SYMBOL(netdev_lower_get_next_private_rcu);
7174 
7175 /**
7176  * netdev_lower_get_next - Get the next device from the lower neighbour
7177  *                         list
7178  * @dev: device
7179  * @iter: list_head ** of the current position
7180  *
7181  * Gets the next netdev_adjacent from the dev's lower neighbour
7182  * list, starting from iter position. The caller must hold RTNL lock or
7183  * its own locking that guarantees that the neighbour lower
7184  * list will remain unchanged.
7185  */
netdev_lower_get_next(struct net_device * dev,struct list_head ** iter)7186 void *netdev_lower_get_next(struct net_device *dev, struct list_head **iter)
7187 {
7188 	struct netdev_adjacent *lower;
7189 
7190 	lower = list_entry(*iter, struct netdev_adjacent, list);
7191 
7192 	if (&lower->list == &dev->adj_list.lower)
7193 		return NULL;
7194 
7195 	*iter = lower->list.next;
7196 
7197 	return lower->dev;
7198 }
7199 EXPORT_SYMBOL(netdev_lower_get_next);
7200 
netdev_next_lower_dev(struct net_device * dev,struct list_head ** iter)7201 static struct net_device *netdev_next_lower_dev(struct net_device *dev,
7202 						struct list_head **iter)
7203 {
7204 	struct netdev_adjacent *lower;
7205 
7206 	lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7207 
7208 	if (&lower->list == &dev->adj_list.lower)
7209 		return NULL;
7210 
7211 	*iter = &lower->list;
7212 
7213 	return lower->dev;
7214 }
7215 
__netdev_next_lower_dev(struct net_device * dev,struct list_head ** iter,bool * ignore)7216 static struct net_device *__netdev_next_lower_dev(struct net_device *dev,
7217 						  struct list_head **iter,
7218 						  bool *ignore)
7219 {
7220 	struct netdev_adjacent *lower;
7221 
7222 	lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7223 
7224 	if (&lower->list == &dev->adj_list.lower)
7225 		return NULL;
7226 
7227 	*iter = &lower->list;
7228 	*ignore = lower->ignore;
7229 
7230 	return lower->dev;
7231 }
7232 
netdev_walk_all_lower_dev(struct net_device * dev,int (* fn)(struct net_device * dev,struct netdev_nested_priv * priv),struct netdev_nested_priv * priv)7233 int netdev_walk_all_lower_dev(struct net_device *dev,
7234 			      int (*fn)(struct net_device *dev,
7235 					struct netdev_nested_priv *priv),
7236 			      struct netdev_nested_priv *priv)
7237 {
7238 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7239 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7240 	int ret, cur = 0;
7241 
7242 	now = dev;
7243 	iter = &dev->adj_list.lower;
7244 
7245 	while (1) {
7246 		if (now != dev) {
7247 			ret = fn(now, priv);
7248 			if (ret)
7249 				return ret;
7250 		}
7251 
7252 		next = NULL;
7253 		while (1) {
7254 			ldev = netdev_next_lower_dev(now, &iter);
7255 			if (!ldev)
7256 				break;
7257 
7258 			next = ldev;
7259 			niter = &ldev->adj_list.lower;
7260 			dev_stack[cur] = now;
7261 			iter_stack[cur++] = iter;
7262 			break;
7263 		}
7264 
7265 		if (!next) {
7266 			if (!cur)
7267 				return 0;
7268 			next = dev_stack[--cur];
7269 			niter = iter_stack[cur];
7270 		}
7271 
7272 		now = next;
7273 		iter = niter;
7274 	}
7275 
7276 	return 0;
7277 }
7278 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev);
7279 
__netdev_walk_all_lower_dev(struct net_device * dev,int (* fn)(struct net_device * dev,struct netdev_nested_priv * priv),struct netdev_nested_priv * priv)7280 static int __netdev_walk_all_lower_dev(struct net_device *dev,
7281 				       int (*fn)(struct net_device *dev,
7282 					 struct netdev_nested_priv *priv),
7283 				       struct netdev_nested_priv *priv)
7284 {
7285 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7286 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7287 	int ret, cur = 0;
7288 	bool ignore;
7289 
7290 	now = dev;
7291 	iter = &dev->adj_list.lower;
7292 
7293 	while (1) {
7294 		if (now != dev) {
7295 			ret = fn(now, priv);
7296 			if (ret)
7297 				return ret;
7298 		}
7299 
7300 		next = NULL;
7301 		while (1) {
7302 			ldev = __netdev_next_lower_dev(now, &iter, &ignore);
7303 			if (!ldev)
7304 				break;
7305 			if (ignore)
7306 				continue;
7307 
7308 			next = ldev;
7309 			niter = &ldev->adj_list.lower;
7310 			dev_stack[cur] = now;
7311 			iter_stack[cur++] = iter;
7312 			break;
7313 		}
7314 
7315 		if (!next) {
7316 			if (!cur)
7317 				return 0;
7318 			next = dev_stack[--cur];
7319 			niter = iter_stack[cur];
7320 		}
7321 
7322 		now = next;
7323 		iter = niter;
7324 	}
7325 
7326 	return 0;
7327 }
7328 
netdev_next_lower_dev_rcu(struct net_device * dev,struct list_head ** iter)7329 struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
7330 					     struct list_head **iter)
7331 {
7332 	struct netdev_adjacent *lower;
7333 
7334 	lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7335 	if (&lower->list == &dev->adj_list.lower)
7336 		return NULL;
7337 
7338 	*iter = &lower->list;
7339 
7340 	return lower->dev;
7341 }
7342 EXPORT_SYMBOL(netdev_next_lower_dev_rcu);
7343 
__netdev_upper_depth(struct net_device * dev)7344 static u8 __netdev_upper_depth(struct net_device *dev)
7345 {
7346 	struct net_device *udev;
7347 	struct list_head *iter;
7348 	u8 max_depth = 0;
7349 	bool ignore;
7350 
7351 	for (iter = &dev->adj_list.upper,
7352 	     udev = __netdev_next_upper_dev(dev, &iter, &ignore);
7353 	     udev;
7354 	     udev = __netdev_next_upper_dev(dev, &iter, &ignore)) {
7355 		if (ignore)
7356 			continue;
7357 		if (max_depth < udev->upper_level)
7358 			max_depth = udev->upper_level;
7359 	}
7360 
7361 	return max_depth;
7362 }
7363 
__netdev_lower_depth(struct net_device * dev)7364 static u8 __netdev_lower_depth(struct net_device *dev)
7365 {
7366 	struct net_device *ldev;
7367 	struct list_head *iter;
7368 	u8 max_depth = 0;
7369 	bool ignore;
7370 
7371 	for (iter = &dev->adj_list.lower,
7372 	     ldev = __netdev_next_lower_dev(dev, &iter, &ignore);
7373 	     ldev;
7374 	     ldev = __netdev_next_lower_dev(dev, &iter, &ignore)) {
7375 		if (ignore)
7376 			continue;
7377 		if (max_depth < ldev->lower_level)
7378 			max_depth = ldev->lower_level;
7379 	}
7380 
7381 	return max_depth;
7382 }
7383 
__netdev_update_upper_level(struct net_device * dev,struct netdev_nested_priv * __unused)7384 static int __netdev_update_upper_level(struct net_device *dev,
7385 				       struct netdev_nested_priv *__unused)
7386 {
7387 	dev->upper_level = __netdev_upper_depth(dev) + 1;
7388 	return 0;
7389 }
7390 
7391 #ifdef CONFIG_LOCKDEP
7392 static LIST_HEAD(net_unlink_list);
7393 
net_unlink_todo(struct net_device * dev)7394 static void net_unlink_todo(struct net_device *dev)
7395 {
7396 	if (list_empty(&dev->unlink_list))
7397 		list_add_tail(&dev->unlink_list, &net_unlink_list);
7398 }
7399 #endif
7400 
__netdev_update_lower_level(struct net_device * dev,struct netdev_nested_priv * priv)7401 static int __netdev_update_lower_level(struct net_device *dev,
7402 				       struct netdev_nested_priv *priv)
7403 {
7404 	dev->lower_level = __netdev_lower_depth(dev) + 1;
7405 
7406 #ifdef CONFIG_LOCKDEP
7407 	if (!priv)
7408 		return 0;
7409 
7410 	if (priv->flags & NESTED_SYNC_IMM)
7411 		dev->nested_level = dev->lower_level - 1;
7412 	if (priv->flags & NESTED_SYNC_TODO)
7413 		net_unlink_todo(dev);
7414 #endif
7415 	return 0;
7416 }
7417 
netdev_walk_all_lower_dev_rcu(struct net_device * dev,int (* fn)(struct net_device * dev,struct netdev_nested_priv * priv),struct netdev_nested_priv * priv)7418 int netdev_walk_all_lower_dev_rcu(struct net_device *dev,
7419 				  int (*fn)(struct net_device *dev,
7420 					    struct netdev_nested_priv *priv),
7421 				  struct netdev_nested_priv *priv)
7422 {
7423 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7424 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7425 	int ret, cur = 0;
7426 
7427 	now = dev;
7428 	iter = &dev->adj_list.lower;
7429 
7430 	while (1) {
7431 		if (now != dev) {
7432 			ret = fn(now, priv);
7433 			if (ret)
7434 				return ret;
7435 		}
7436 
7437 		next = NULL;
7438 		while (1) {
7439 			ldev = netdev_next_lower_dev_rcu(now, &iter);
7440 			if (!ldev)
7441 				break;
7442 
7443 			next = ldev;
7444 			niter = &ldev->adj_list.lower;
7445 			dev_stack[cur] = now;
7446 			iter_stack[cur++] = iter;
7447 			break;
7448 		}
7449 
7450 		if (!next) {
7451 			if (!cur)
7452 				return 0;
7453 			next = dev_stack[--cur];
7454 			niter = iter_stack[cur];
7455 		}
7456 
7457 		now = next;
7458 		iter = niter;
7459 	}
7460 
7461 	return 0;
7462 }
7463 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev_rcu);
7464 
7465 /**
7466  * netdev_lower_get_first_private_rcu - Get the first ->private from the
7467  *				       lower neighbour list, RCU
7468  *				       variant
7469  * @dev: device
7470  *
7471  * Gets the first netdev_adjacent->private from the dev's lower neighbour
7472  * list. The caller must hold RCU read lock.
7473  */
netdev_lower_get_first_private_rcu(struct net_device * dev)7474 void *netdev_lower_get_first_private_rcu(struct net_device *dev)
7475 {
7476 	struct netdev_adjacent *lower;
7477 
7478 	lower = list_first_or_null_rcu(&dev->adj_list.lower,
7479 			struct netdev_adjacent, list);
7480 	if (lower)
7481 		return lower->private;
7482 	return NULL;
7483 }
7484 EXPORT_SYMBOL(netdev_lower_get_first_private_rcu);
7485 
7486 /**
7487  * netdev_master_upper_dev_get_rcu - Get master upper device
7488  * @dev: device
7489  *
7490  * Find a master upper device and return pointer to it or NULL in case
7491  * it's not there. The caller must hold the RCU read lock.
7492  */
netdev_master_upper_dev_get_rcu(struct net_device * dev)7493 struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev)
7494 {
7495 	struct netdev_adjacent *upper;
7496 
7497 	upper = list_first_or_null_rcu(&dev->adj_list.upper,
7498 				       struct netdev_adjacent, list);
7499 	if (upper && likely(upper->master))
7500 		return upper->dev;
7501 	return NULL;
7502 }
7503 EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);
7504 
netdev_adjacent_sysfs_add(struct net_device * dev,struct net_device * adj_dev,struct list_head * dev_list)7505 static int netdev_adjacent_sysfs_add(struct net_device *dev,
7506 			      struct net_device *adj_dev,
7507 			      struct list_head *dev_list)
7508 {
7509 	char linkname[IFNAMSIZ+7];
7510 
7511 	sprintf(linkname, dev_list == &dev->adj_list.upper ?
7512 		"upper_%s" : "lower_%s", adj_dev->name);
7513 	return sysfs_create_link(&(dev->dev.kobj), &(adj_dev->dev.kobj),
7514 				 linkname);
7515 }
netdev_adjacent_sysfs_del(struct net_device * dev,char * name,struct list_head * dev_list)7516 static void netdev_adjacent_sysfs_del(struct net_device *dev,
7517 			       char *name,
7518 			       struct list_head *dev_list)
7519 {
7520 	char linkname[IFNAMSIZ+7];
7521 
7522 	sprintf(linkname, dev_list == &dev->adj_list.upper ?
7523 		"upper_%s" : "lower_%s", name);
7524 	sysfs_remove_link(&(dev->dev.kobj), linkname);
7525 }
7526 
netdev_adjacent_is_neigh_list(struct net_device * dev,struct net_device * adj_dev,struct list_head * dev_list)7527 static inline bool netdev_adjacent_is_neigh_list(struct net_device *dev,
7528 						 struct net_device *adj_dev,
7529 						 struct list_head *dev_list)
7530 {
7531 	return (dev_list == &dev->adj_list.upper ||
7532 		dev_list == &dev->adj_list.lower) &&
7533 		net_eq(dev_net(dev), dev_net(adj_dev));
7534 }
7535 
__netdev_adjacent_dev_insert(struct net_device * dev,struct net_device * adj_dev,struct list_head * dev_list,void * private,bool master)7536 static int __netdev_adjacent_dev_insert(struct net_device *dev,
7537 					struct net_device *adj_dev,
7538 					struct list_head *dev_list,
7539 					void *private, bool master)
7540 {
7541 	struct netdev_adjacent *adj;
7542 	int ret;
7543 
7544 	adj = __netdev_find_adj(adj_dev, dev_list);
7545 
7546 	if (adj) {
7547 		adj->ref_nr += 1;
7548 		pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d\n",
7549 			 dev->name, adj_dev->name, adj->ref_nr);
7550 
7551 		return 0;
7552 	}
7553 
7554 	adj = kmalloc(sizeof(*adj), GFP_KERNEL);
7555 	if (!adj)
7556 		return -ENOMEM;
7557 
7558 	adj->dev = adj_dev;
7559 	adj->master = master;
7560 	adj->ref_nr = 1;
7561 	adj->private = private;
7562 	adj->ignore = false;
7563 	netdev_hold(adj_dev, &adj->dev_tracker, GFP_KERNEL);
7564 
7565 	pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d; dev_hold on %s\n",
7566 		 dev->name, adj_dev->name, adj->ref_nr, adj_dev->name);
7567 
7568 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list)) {
7569 		ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list);
7570 		if (ret)
7571 			goto free_adj;
7572 	}
7573 
7574 	/* Ensure that master link is always the first item in list. */
7575 	if (master) {
7576 		ret = sysfs_create_link(&(dev->dev.kobj),
7577 					&(adj_dev->dev.kobj), "master");
7578 		if (ret)
7579 			goto remove_symlinks;
7580 
7581 		list_add_rcu(&adj->list, dev_list);
7582 	} else {
7583 		list_add_tail_rcu(&adj->list, dev_list);
7584 	}
7585 
7586 	return 0;
7587 
7588 remove_symlinks:
7589 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
7590 		netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
7591 free_adj:
7592 	netdev_put(adj_dev, &adj->dev_tracker);
7593 	kfree(adj);
7594 
7595 	return ret;
7596 }
7597 
__netdev_adjacent_dev_remove(struct net_device * dev,struct net_device * adj_dev,u16 ref_nr,struct list_head * dev_list)7598 static void __netdev_adjacent_dev_remove(struct net_device *dev,
7599 					 struct net_device *adj_dev,
7600 					 u16 ref_nr,
7601 					 struct list_head *dev_list)
7602 {
7603 	struct netdev_adjacent *adj;
7604 
7605 	pr_debug("Remove adjacency: dev %s adj_dev %s ref_nr %d\n",
7606 		 dev->name, adj_dev->name, ref_nr);
7607 
7608 	adj = __netdev_find_adj(adj_dev, dev_list);
7609 
7610 	if (!adj) {
7611 		pr_err("Adjacency does not exist for device %s from %s\n",
7612 		       dev->name, adj_dev->name);
7613 		WARN_ON(1);
7614 		return;
7615 	}
7616 
7617 	if (adj->ref_nr > ref_nr) {
7618 		pr_debug("adjacency: %s to %s ref_nr - %d = %d\n",
7619 			 dev->name, adj_dev->name, ref_nr,
7620 			 adj->ref_nr - ref_nr);
7621 		adj->ref_nr -= ref_nr;
7622 		return;
7623 	}
7624 
7625 	if (adj->master)
7626 		sysfs_remove_link(&(dev->dev.kobj), "master");
7627 
7628 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
7629 		netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
7630 
7631 	list_del_rcu(&adj->list);
7632 	pr_debug("adjacency: dev_put for %s, because link removed from %s to %s\n",
7633 		 adj_dev->name, dev->name, adj_dev->name);
7634 	netdev_put(adj_dev, &adj->dev_tracker);
7635 	kfree_rcu(adj, rcu);
7636 }
7637 
__netdev_adjacent_dev_link_lists(struct net_device * dev,struct net_device * upper_dev,struct list_head * up_list,struct list_head * down_list,void * private,bool master)7638 static int __netdev_adjacent_dev_link_lists(struct net_device *dev,
7639 					    struct net_device *upper_dev,
7640 					    struct list_head *up_list,
7641 					    struct list_head *down_list,
7642 					    void *private, bool master)
7643 {
7644 	int ret;
7645 
7646 	ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list,
7647 					   private, master);
7648 	if (ret)
7649 		return ret;
7650 
7651 	ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list,
7652 					   private, false);
7653 	if (ret) {
7654 		__netdev_adjacent_dev_remove(dev, upper_dev, 1, up_list);
7655 		return ret;
7656 	}
7657 
7658 	return 0;
7659 }
7660 
__netdev_adjacent_dev_unlink_lists(struct net_device * dev,struct net_device * upper_dev,u16 ref_nr,struct list_head * up_list,struct list_head * down_list)7661 static void __netdev_adjacent_dev_unlink_lists(struct net_device *dev,
7662 					       struct net_device *upper_dev,
7663 					       u16 ref_nr,
7664 					       struct list_head *up_list,
7665 					       struct list_head *down_list)
7666 {
7667 	__netdev_adjacent_dev_remove(dev, upper_dev, ref_nr, up_list);
7668 	__netdev_adjacent_dev_remove(upper_dev, dev, ref_nr, down_list);
7669 }
7670 
__netdev_adjacent_dev_link_neighbour(struct net_device * dev,struct net_device * upper_dev,void * private,bool master)7671 static int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
7672 						struct net_device *upper_dev,
7673 						void *private, bool master)
7674 {
7675 	return __netdev_adjacent_dev_link_lists(dev, upper_dev,
7676 						&dev->adj_list.upper,
7677 						&upper_dev->adj_list.lower,
7678 						private, master);
7679 }
7680 
__netdev_adjacent_dev_unlink_neighbour(struct net_device * dev,struct net_device * upper_dev)7681 static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
7682 						   struct net_device *upper_dev)
7683 {
7684 	__netdev_adjacent_dev_unlink_lists(dev, upper_dev, 1,
7685 					   &dev->adj_list.upper,
7686 					   &upper_dev->adj_list.lower);
7687 }
7688 
__netdev_upper_dev_link(struct net_device * dev,struct net_device * upper_dev,bool master,void * upper_priv,void * upper_info,struct netdev_nested_priv * priv,struct netlink_ext_ack * extack)7689 static int __netdev_upper_dev_link(struct net_device *dev,
7690 				   struct net_device *upper_dev, bool master,
7691 				   void *upper_priv, void *upper_info,
7692 				   struct netdev_nested_priv *priv,
7693 				   struct netlink_ext_ack *extack)
7694 {
7695 	struct netdev_notifier_changeupper_info changeupper_info = {
7696 		.info = {
7697 			.dev = dev,
7698 			.extack = extack,
7699 		},
7700 		.upper_dev = upper_dev,
7701 		.master = master,
7702 		.linking = true,
7703 		.upper_info = upper_info,
7704 	};
7705 	struct net_device *master_dev;
7706 	int ret = 0;
7707 
7708 	ASSERT_RTNL();
7709 
7710 	if (dev == upper_dev)
7711 		return -EBUSY;
7712 
7713 	/* To prevent loops, check if dev is not upper device to upper_dev. */
7714 	if (__netdev_has_upper_dev(upper_dev, dev))
7715 		return -EBUSY;
7716 
7717 	if ((dev->lower_level + upper_dev->upper_level) > MAX_NEST_DEV)
7718 		return -EMLINK;
7719 
7720 	if (!master) {
7721 		if (__netdev_has_upper_dev(dev, upper_dev))
7722 			return -EEXIST;
7723 	} else {
7724 		master_dev = __netdev_master_upper_dev_get(dev);
7725 		if (master_dev)
7726 			return master_dev == upper_dev ? -EEXIST : -EBUSY;
7727 	}
7728 
7729 	ret = call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
7730 					    &changeupper_info.info);
7731 	ret = notifier_to_errno(ret);
7732 	if (ret)
7733 		return ret;
7734 
7735 	ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, upper_priv,
7736 						   master);
7737 	if (ret)
7738 		return ret;
7739 
7740 	ret = call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
7741 					    &changeupper_info.info);
7742 	ret = notifier_to_errno(ret);
7743 	if (ret)
7744 		goto rollback;
7745 
7746 	__netdev_update_upper_level(dev, NULL);
7747 	__netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
7748 
7749 	__netdev_update_lower_level(upper_dev, priv);
7750 	__netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
7751 				    priv);
7752 
7753 	return 0;
7754 
7755 rollback:
7756 	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
7757 
7758 	return ret;
7759 }
7760 
7761 /**
7762  * netdev_upper_dev_link - Add a link to the upper device
7763  * @dev: device
7764  * @upper_dev: new upper device
7765  * @extack: netlink extended ack
7766  *
7767  * Adds a link to device which is upper to this one. The caller must hold
7768  * the RTNL lock. On a failure a negative errno code is returned.
7769  * On success the reference counts are adjusted and the function
7770  * returns zero.
7771  */
netdev_upper_dev_link(struct net_device * dev,struct net_device * upper_dev,struct netlink_ext_ack * extack)7772 int netdev_upper_dev_link(struct net_device *dev,
7773 			  struct net_device *upper_dev,
7774 			  struct netlink_ext_ack *extack)
7775 {
7776 	struct netdev_nested_priv priv = {
7777 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7778 		.data = NULL,
7779 	};
7780 
7781 	return __netdev_upper_dev_link(dev, upper_dev, false,
7782 				       NULL, NULL, &priv, extack);
7783 }
7784 EXPORT_SYMBOL(netdev_upper_dev_link);
7785 
7786 /**
7787  * netdev_master_upper_dev_link - Add a master link to the upper device
7788  * @dev: device
7789  * @upper_dev: new upper device
7790  * @upper_priv: upper device private
7791  * @upper_info: upper info to be passed down via notifier
7792  * @extack: netlink extended ack
7793  *
7794  * Adds a link to device which is upper to this one. In this case, only
7795  * one master upper device can be linked, although other non-master devices
7796  * might be linked as well. The caller must hold the RTNL lock.
7797  * On a failure a negative errno code is returned. On success the reference
7798  * counts are adjusted and the function returns zero.
7799  */
netdev_master_upper_dev_link(struct net_device * dev,struct net_device * upper_dev,void * upper_priv,void * upper_info,struct netlink_ext_ack * extack)7800 int netdev_master_upper_dev_link(struct net_device *dev,
7801 				 struct net_device *upper_dev,
7802 				 void *upper_priv, void *upper_info,
7803 				 struct netlink_ext_ack *extack)
7804 {
7805 	struct netdev_nested_priv priv = {
7806 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7807 		.data = NULL,
7808 	};
7809 
7810 	return __netdev_upper_dev_link(dev, upper_dev, true,
7811 				       upper_priv, upper_info, &priv, extack);
7812 }
7813 EXPORT_SYMBOL(netdev_master_upper_dev_link);
7814 
__netdev_upper_dev_unlink(struct net_device * dev,struct net_device * upper_dev,struct netdev_nested_priv * priv)7815 static void __netdev_upper_dev_unlink(struct net_device *dev,
7816 				      struct net_device *upper_dev,
7817 				      struct netdev_nested_priv *priv)
7818 {
7819 	struct netdev_notifier_changeupper_info changeupper_info = {
7820 		.info = {
7821 			.dev = dev,
7822 		},
7823 		.upper_dev = upper_dev,
7824 		.linking = false,
7825 	};
7826 
7827 	ASSERT_RTNL();
7828 
7829 	changeupper_info.master = netdev_master_upper_dev_get(dev) == upper_dev;
7830 
7831 	call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
7832 				      &changeupper_info.info);
7833 
7834 	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
7835 
7836 	call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
7837 				      &changeupper_info.info);
7838 
7839 	__netdev_update_upper_level(dev, NULL);
7840 	__netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
7841 
7842 	__netdev_update_lower_level(upper_dev, priv);
7843 	__netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
7844 				    priv);
7845 }
7846 
7847 /**
7848  * netdev_upper_dev_unlink - Removes a link to upper device
7849  * @dev: device
7850  * @upper_dev: new upper device
7851  *
7852  * Removes a link to device which is upper to this one. The caller must hold
7853  * the RTNL lock.
7854  */
netdev_upper_dev_unlink(struct net_device * dev,struct net_device * upper_dev)7855 void netdev_upper_dev_unlink(struct net_device *dev,
7856 			     struct net_device *upper_dev)
7857 {
7858 	struct netdev_nested_priv priv = {
7859 		.flags = NESTED_SYNC_TODO,
7860 		.data = NULL,
7861 	};
7862 
7863 	__netdev_upper_dev_unlink(dev, upper_dev, &priv);
7864 }
7865 EXPORT_SYMBOL(netdev_upper_dev_unlink);
7866 
__netdev_adjacent_dev_set(struct net_device * upper_dev,struct net_device * lower_dev,bool val)7867 static void __netdev_adjacent_dev_set(struct net_device *upper_dev,
7868 				      struct net_device *lower_dev,
7869 				      bool val)
7870 {
7871 	struct netdev_adjacent *adj;
7872 
7873 	adj = __netdev_find_adj(lower_dev, &upper_dev->adj_list.lower);
7874 	if (adj)
7875 		adj->ignore = val;
7876 
7877 	adj = __netdev_find_adj(upper_dev, &lower_dev->adj_list.upper);
7878 	if (adj)
7879 		adj->ignore = val;
7880 }
7881 
netdev_adjacent_dev_disable(struct net_device * upper_dev,struct net_device * lower_dev)7882 static void netdev_adjacent_dev_disable(struct net_device *upper_dev,
7883 					struct net_device *lower_dev)
7884 {
7885 	__netdev_adjacent_dev_set(upper_dev, lower_dev, true);
7886 }
7887 
netdev_adjacent_dev_enable(struct net_device * upper_dev,struct net_device * lower_dev)7888 static void netdev_adjacent_dev_enable(struct net_device *upper_dev,
7889 				       struct net_device *lower_dev)
7890 {
7891 	__netdev_adjacent_dev_set(upper_dev, lower_dev, false);
7892 }
7893 
netdev_adjacent_change_prepare(struct net_device * old_dev,struct net_device * new_dev,struct net_device * dev,struct netlink_ext_ack * extack)7894 int netdev_adjacent_change_prepare(struct net_device *old_dev,
7895 				   struct net_device *new_dev,
7896 				   struct net_device *dev,
7897 				   struct netlink_ext_ack *extack)
7898 {
7899 	struct netdev_nested_priv priv = {
7900 		.flags = 0,
7901 		.data = NULL,
7902 	};
7903 	int err;
7904 
7905 	if (!new_dev)
7906 		return 0;
7907 
7908 	if (old_dev && new_dev != old_dev)
7909 		netdev_adjacent_dev_disable(dev, old_dev);
7910 	err = __netdev_upper_dev_link(new_dev, dev, false, NULL, NULL, &priv,
7911 				      extack);
7912 	if (err) {
7913 		if (old_dev && new_dev != old_dev)
7914 			netdev_adjacent_dev_enable(dev, old_dev);
7915 		return err;
7916 	}
7917 
7918 	return 0;
7919 }
7920 EXPORT_SYMBOL(netdev_adjacent_change_prepare);
7921 
netdev_adjacent_change_commit(struct net_device * old_dev,struct net_device * new_dev,struct net_device * dev)7922 void netdev_adjacent_change_commit(struct net_device *old_dev,
7923 				   struct net_device *new_dev,
7924 				   struct net_device *dev)
7925 {
7926 	struct netdev_nested_priv priv = {
7927 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7928 		.data = NULL,
7929 	};
7930 
7931 	if (!new_dev || !old_dev)
7932 		return;
7933 
7934 	if (new_dev == old_dev)
7935 		return;
7936 
7937 	netdev_adjacent_dev_enable(dev, old_dev);
7938 	__netdev_upper_dev_unlink(old_dev, dev, &priv);
7939 }
7940 EXPORT_SYMBOL(netdev_adjacent_change_commit);
7941 
netdev_adjacent_change_abort(struct net_device * old_dev,struct net_device * new_dev,struct net_device * dev)7942 void netdev_adjacent_change_abort(struct net_device *old_dev,
7943 				  struct net_device *new_dev,
7944 				  struct net_device *dev)
7945 {
7946 	struct netdev_nested_priv priv = {
7947 		.flags = 0,
7948 		.data = NULL,
7949 	};
7950 
7951 	if (!new_dev)
7952 		return;
7953 
7954 	if (old_dev && new_dev != old_dev)
7955 		netdev_adjacent_dev_enable(dev, old_dev);
7956 
7957 	__netdev_upper_dev_unlink(new_dev, dev, &priv);
7958 }
7959 EXPORT_SYMBOL(netdev_adjacent_change_abort);
7960 
7961 /**
7962  * netdev_bonding_info_change - Dispatch event about slave change
7963  * @dev: device
7964  * @bonding_info: info to dispatch
7965  *
7966  * Send NETDEV_BONDING_INFO to netdev notifiers with info.
7967  * The caller must hold the RTNL lock.
7968  */
netdev_bonding_info_change(struct net_device * dev,struct netdev_bonding_info * bonding_info)7969 void netdev_bonding_info_change(struct net_device *dev,
7970 				struct netdev_bonding_info *bonding_info)
7971 {
7972 	struct netdev_notifier_bonding_info info = {
7973 		.info.dev = dev,
7974 	};
7975 
7976 	memcpy(&info.bonding_info, bonding_info,
7977 	       sizeof(struct netdev_bonding_info));
7978 	call_netdevice_notifiers_info(NETDEV_BONDING_INFO,
7979 				      &info.info);
7980 }
7981 EXPORT_SYMBOL(netdev_bonding_info_change);
7982 
netdev_offload_xstats_enable_l3(struct net_device * dev,struct netlink_ext_ack * extack)7983 static int netdev_offload_xstats_enable_l3(struct net_device *dev,
7984 					   struct netlink_ext_ack *extack)
7985 {
7986 	struct netdev_notifier_offload_xstats_info info = {
7987 		.info.dev = dev,
7988 		.info.extack = extack,
7989 		.type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
7990 	};
7991 	int err;
7992 	int rc;
7993 
7994 	dev->offload_xstats_l3 = kzalloc(sizeof(*dev->offload_xstats_l3),
7995 					 GFP_KERNEL);
7996 	if (!dev->offload_xstats_l3)
7997 		return -ENOMEM;
7998 
7999 	rc = call_netdevice_notifiers_info_robust(NETDEV_OFFLOAD_XSTATS_ENABLE,
8000 						  NETDEV_OFFLOAD_XSTATS_DISABLE,
8001 						  &info.info);
8002 	err = notifier_to_errno(rc);
8003 	if (err)
8004 		goto free_stats;
8005 
8006 	return 0;
8007 
8008 free_stats:
8009 	kfree(dev->offload_xstats_l3);
8010 	dev->offload_xstats_l3 = NULL;
8011 	return err;
8012 }
8013 
netdev_offload_xstats_enable(struct net_device * dev,enum netdev_offload_xstats_type type,struct netlink_ext_ack * extack)8014 int netdev_offload_xstats_enable(struct net_device *dev,
8015 				 enum netdev_offload_xstats_type type,
8016 				 struct netlink_ext_ack *extack)
8017 {
8018 	ASSERT_RTNL();
8019 
8020 	if (netdev_offload_xstats_enabled(dev, type))
8021 		return -EALREADY;
8022 
8023 	switch (type) {
8024 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
8025 		return netdev_offload_xstats_enable_l3(dev, extack);
8026 	}
8027 
8028 	WARN_ON(1);
8029 	return -EINVAL;
8030 }
8031 EXPORT_SYMBOL(netdev_offload_xstats_enable);
8032 
netdev_offload_xstats_disable_l3(struct net_device * dev)8033 static void netdev_offload_xstats_disable_l3(struct net_device *dev)
8034 {
8035 	struct netdev_notifier_offload_xstats_info info = {
8036 		.info.dev = dev,
8037 		.type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
8038 	};
8039 
8040 	call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_DISABLE,
8041 				      &info.info);
8042 	kfree(dev->offload_xstats_l3);
8043 	dev->offload_xstats_l3 = NULL;
8044 }
8045 
netdev_offload_xstats_disable(struct net_device * dev,enum netdev_offload_xstats_type type)8046 int netdev_offload_xstats_disable(struct net_device *dev,
8047 				  enum netdev_offload_xstats_type type)
8048 {
8049 	ASSERT_RTNL();
8050 
8051 	if (!netdev_offload_xstats_enabled(dev, type))
8052 		return -EALREADY;
8053 
8054 	switch (type) {
8055 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
8056 		netdev_offload_xstats_disable_l3(dev);
8057 		return 0;
8058 	}
8059 
8060 	WARN_ON(1);
8061 	return -EINVAL;
8062 }
8063 EXPORT_SYMBOL(netdev_offload_xstats_disable);
8064 
netdev_offload_xstats_disable_all(struct net_device * dev)8065 static void netdev_offload_xstats_disable_all(struct net_device *dev)
8066 {
8067 	netdev_offload_xstats_disable(dev, NETDEV_OFFLOAD_XSTATS_TYPE_L3);
8068 }
8069 
8070 static struct rtnl_hw_stats64 *
netdev_offload_xstats_get_ptr(const struct net_device * dev,enum netdev_offload_xstats_type type)8071 netdev_offload_xstats_get_ptr(const struct net_device *dev,
8072 			      enum netdev_offload_xstats_type type)
8073 {
8074 	switch (type) {
8075 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
8076 		return dev->offload_xstats_l3;
8077 	}
8078 
8079 	WARN_ON(1);
8080 	return NULL;
8081 }
8082 
netdev_offload_xstats_enabled(const struct net_device * dev,enum netdev_offload_xstats_type type)8083 bool netdev_offload_xstats_enabled(const struct net_device *dev,
8084 				   enum netdev_offload_xstats_type type)
8085 {
8086 	ASSERT_RTNL();
8087 
8088 	return netdev_offload_xstats_get_ptr(dev, type);
8089 }
8090 EXPORT_SYMBOL(netdev_offload_xstats_enabled);
8091 
8092 struct netdev_notifier_offload_xstats_ru {
8093 	bool used;
8094 };
8095 
8096 struct netdev_notifier_offload_xstats_rd {
8097 	struct rtnl_hw_stats64 stats;
8098 	bool used;
8099 };
8100 
netdev_hw_stats64_add(struct rtnl_hw_stats64 * dest,const struct rtnl_hw_stats64 * src)8101 static void netdev_hw_stats64_add(struct rtnl_hw_stats64 *dest,
8102 				  const struct rtnl_hw_stats64 *src)
8103 {
8104 	dest->rx_packets	  += src->rx_packets;
8105 	dest->tx_packets	  += src->tx_packets;
8106 	dest->rx_bytes		  += src->rx_bytes;
8107 	dest->tx_bytes		  += src->tx_bytes;
8108 	dest->rx_errors		  += src->rx_errors;
8109 	dest->tx_errors		  += src->tx_errors;
8110 	dest->rx_dropped	  += src->rx_dropped;
8111 	dest->tx_dropped	  += src->tx_dropped;
8112 	dest->multicast		  += src->multicast;
8113 }
8114 
netdev_offload_xstats_get_used(struct net_device * dev,enum netdev_offload_xstats_type type,bool * p_used,struct netlink_ext_ack * extack)8115 static int netdev_offload_xstats_get_used(struct net_device *dev,
8116 					  enum netdev_offload_xstats_type type,
8117 					  bool *p_used,
8118 					  struct netlink_ext_ack *extack)
8119 {
8120 	struct netdev_notifier_offload_xstats_ru report_used = {};
8121 	struct netdev_notifier_offload_xstats_info info = {
8122 		.info.dev = dev,
8123 		.info.extack = extack,
8124 		.type = type,
8125 		.report_used = &report_used,
8126 	};
8127 	int rc;
8128 
8129 	WARN_ON(!netdev_offload_xstats_enabled(dev, type));
8130 	rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_USED,
8131 					   &info.info);
8132 	*p_used = report_used.used;
8133 	return notifier_to_errno(rc);
8134 }
8135 
netdev_offload_xstats_get_stats(struct net_device * dev,enum netdev_offload_xstats_type type,struct rtnl_hw_stats64 * p_stats,bool * p_used,struct netlink_ext_ack * extack)8136 static int netdev_offload_xstats_get_stats(struct net_device *dev,
8137 					   enum netdev_offload_xstats_type type,
8138 					   struct rtnl_hw_stats64 *p_stats,
8139 					   bool *p_used,
8140 					   struct netlink_ext_ack *extack)
8141 {
8142 	struct netdev_notifier_offload_xstats_rd report_delta = {};
8143 	struct netdev_notifier_offload_xstats_info info = {
8144 		.info.dev = dev,
8145 		.info.extack = extack,
8146 		.type = type,
8147 		.report_delta = &report_delta,
8148 	};
8149 	struct rtnl_hw_stats64 *stats;
8150 	int rc;
8151 
8152 	stats = netdev_offload_xstats_get_ptr(dev, type);
8153 	if (WARN_ON(!stats))
8154 		return -EINVAL;
8155 
8156 	rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_DELTA,
8157 					   &info.info);
8158 
8159 	/* Cache whatever we got, even if there was an error, otherwise the
8160 	 * successful stats retrievals would get lost.
8161 	 */
8162 	netdev_hw_stats64_add(stats, &report_delta.stats);
8163 
8164 	if (p_stats)
8165 		*p_stats = *stats;
8166 	*p_used = report_delta.used;
8167 
8168 	return notifier_to_errno(rc);
8169 }
8170 
netdev_offload_xstats_get(struct net_device * dev,enum netdev_offload_xstats_type type,struct rtnl_hw_stats64 * p_stats,bool * p_used,struct netlink_ext_ack * extack)8171 int netdev_offload_xstats_get(struct net_device *dev,
8172 			      enum netdev_offload_xstats_type type,
8173 			      struct rtnl_hw_stats64 *p_stats, bool *p_used,
8174 			      struct netlink_ext_ack *extack)
8175 {
8176 	ASSERT_RTNL();
8177 
8178 	if (p_stats)
8179 		return netdev_offload_xstats_get_stats(dev, type, p_stats,
8180 						       p_used, extack);
8181 	else
8182 		return netdev_offload_xstats_get_used(dev, type, p_used,
8183 						      extack);
8184 }
8185 EXPORT_SYMBOL(netdev_offload_xstats_get);
8186 
8187 void
netdev_offload_xstats_report_delta(struct netdev_notifier_offload_xstats_rd * report_delta,const struct rtnl_hw_stats64 * stats)8188 netdev_offload_xstats_report_delta(struct netdev_notifier_offload_xstats_rd *report_delta,
8189 				   const struct rtnl_hw_stats64 *stats)
8190 {
8191 	report_delta->used = true;
8192 	netdev_hw_stats64_add(&report_delta->stats, stats);
8193 }
8194 EXPORT_SYMBOL(netdev_offload_xstats_report_delta);
8195 
8196 void
netdev_offload_xstats_report_used(struct netdev_notifier_offload_xstats_ru * report_used)8197 netdev_offload_xstats_report_used(struct netdev_notifier_offload_xstats_ru *report_used)
8198 {
8199 	report_used->used = true;
8200 }
8201 EXPORT_SYMBOL(netdev_offload_xstats_report_used);
8202 
netdev_offload_xstats_push_delta(struct net_device * dev,enum netdev_offload_xstats_type type,const struct rtnl_hw_stats64 * p_stats)8203 void netdev_offload_xstats_push_delta(struct net_device *dev,
8204 				      enum netdev_offload_xstats_type type,
8205 				      const struct rtnl_hw_stats64 *p_stats)
8206 {
8207 	struct rtnl_hw_stats64 *stats;
8208 
8209 	ASSERT_RTNL();
8210 
8211 	stats = netdev_offload_xstats_get_ptr(dev, type);
8212 	if (WARN_ON(!stats))
8213 		return;
8214 
8215 	netdev_hw_stats64_add(stats, p_stats);
8216 }
8217 EXPORT_SYMBOL(netdev_offload_xstats_push_delta);
8218 
8219 /**
8220  * netdev_get_xmit_slave - Get the xmit slave of master device
8221  * @dev: device
8222  * @skb: The packet
8223  * @all_slaves: assume all the slaves are active
8224  *
8225  * The reference counters are not incremented so the caller must be
8226  * careful with locks. The caller must hold RCU lock.
8227  * %NULL is returned if no slave is found.
8228  */
8229 
netdev_get_xmit_slave(struct net_device * dev,struct sk_buff * skb,bool all_slaves)8230 struct net_device *netdev_get_xmit_slave(struct net_device *dev,
8231 					 struct sk_buff *skb,
8232 					 bool all_slaves)
8233 {
8234 	const struct net_device_ops *ops = dev->netdev_ops;
8235 
8236 	if (!ops->ndo_get_xmit_slave)
8237 		return NULL;
8238 	return ops->ndo_get_xmit_slave(dev, skb, all_slaves);
8239 }
8240 EXPORT_SYMBOL(netdev_get_xmit_slave);
8241 
netdev_sk_get_lower_dev(struct net_device * dev,struct sock * sk)8242 static struct net_device *netdev_sk_get_lower_dev(struct net_device *dev,
8243 						  struct sock *sk)
8244 {
8245 	const struct net_device_ops *ops = dev->netdev_ops;
8246 
8247 	if (!ops->ndo_sk_get_lower_dev)
8248 		return NULL;
8249 	return ops->ndo_sk_get_lower_dev(dev, sk);
8250 }
8251 
8252 /**
8253  * netdev_sk_get_lowest_dev - Get the lowest device in chain given device and socket
8254  * @dev: device
8255  * @sk: the socket
8256  *
8257  * %NULL is returned if no lower device is found.
8258  */
8259 
netdev_sk_get_lowest_dev(struct net_device * dev,struct sock * sk)8260 struct net_device *netdev_sk_get_lowest_dev(struct net_device *dev,
8261 					    struct sock *sk)
8262 {
8263 	struct net_device *lower;
8264 
8265 	lower = netdev_sk_get_lower_dev(dev, sk);
8266 	while (lower) {
8267 		dev = lower;
8268 		lower = netdev_sk_get_lower_dev(dev, sk);
8269 	}
8270 
8271 	return dev;
8272 }
8273 EXPORT_SYMBOL(netdev_sk_get_lowest_dev);
8274 
netdev_adjacent_add_links(struct net_device * dev)8275 static void netdev_adjacent_add_links(struct net_device *dev)
8276 {
8277 	struct netdev_adjacent *iter;
8278 
8279 	struct net *net = dev_net(dev);
8280 
8281 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8282 		if (!net_eq(net, dev_net(iter->dev)))
8283 			continue;
8284 		netdev_adjacent_sysfs_add(iter->dev, dev,
8285 					  &iter->dev->adj_list.lower);
8286 		netdev_adjacent_sysfs_add(dev, iter->dev,
8287 					  &dev->adj_list.upper);
8288 	}
8289 
8290 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8291 		if (!net_eq(net, dev_net(iter->dev)))
8292 			continue;
8293 		netdev_adjacent_sysfs_add(iter->dev, dev,
8294 					  &iter->dev->adj_list.upper);
8295 		netdev_adjacent_sysfs_add(dev, iter->dev,
8296 					  &dev->adj_list.lower);
8297 	}
8298 }
8299 
netdev_adjacent_del_links(struct net_device * dev)8300 static void netdev_adjacent_del_links(struct net_device *dev)
8301 {
8302 	struct netdev_adjacent *iter;
8303 
8304 	struct net *net = dev_net(dev);
8305 
8306 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8307 		if (!net_eq(net, dev_net(iter->dev)))
8308 			continue;
8309 		netdev_adjacent_sysfs_del(iter->dev, dev->name,
8310 					  &iter->dev->adj_list.lower);
8311 		netdev_adjacent_sysfs_del(dev, iter->dev->name,
8312 					  &dev->adj_list.upper);
8313 	}
8314 
8315 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8316 		if (!net_eq(net, dev_net(iter->dev)))
8317 			continue;
8318 		netdev_adjacent_sysfs_del(iter->dev, dev->name,
8319 					  &iter->dev->adj_list.upper);
8320 		netdev_adjacent_sysfs_del(dev, iter->dev->name,
8321 					  &dev->adj_list.lower);
8322 	}
8323 }
8324 
netdev_adjacent_rename_links(struct net_device * dev,char * oldname)8325 void netdev_adjacent_rename_links(struct net_device *dev, char *oldname)
8326 {
8327 	struct netdev_adjacent *iter;
8328 
8329 	struct net *net = dev_net(dev);
8330 
8331 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8332 		if (!net_eq(net, dev_net(iter->dev)))
8333 			continue;
8334 		netdev_adjacent_sysfs_del(iter->dev, oldname,
8335 					  &iter->dev->adj_list.lower);
8336 		netdev_adjacent_sysfs_add(iter->dev, dev,
8337 					  &iter->dev->adj_list.lower);
8338 	}
8339 
8340 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8341 		if (!net_eq(net, dev_net(iter->dev)))
8342 			continue;
8343 		netdev_adjacent_sysfs_del(iter->dev, oldname,
8344 					  &iter->dev->adj_list.upper);
8345 		netdev_adjacent_sysfs_add(iter->dev, dev,
8346 					  &iter->dev->adj_list.upper);
8347 	}
8348 }
8349 
netdev_lower_dev_get_private(struct net_device * dev,struct net_device * lower_dev)8350 void *netdev_lower_dev_get_private(struct net_device *dev,
8351 				   struct net_device *lower_dev)
8352 {
8353 	struct netdev_adjacent *lower;
8354 
8355 	if (!lower_dev)
8356 		return NULL;
8357 	lower = __netdev_find_adj(lower_dev, &dev->adj_list.lower);
8358 	if (!lower)
8359 		return NULL;
8360 
8361 	return lower->private;
8362 }
8363 EXPORT_SYMBOL(netdev_lower_dev_get_private);
8364 
8365 
8366 /**
8367  * netdev_lower_state_changed - Dispatch event about lower device state change
8368  * @lower_dev: device
8369  * @lower_state_info: state to dispatch
8370  *
8371  * Send NETDEV_CHANGELOWERSTATE to netdev notifiers with info.
8372  * The caller must hold the RTNL lock.
8373  */
netdev_lower_state_changed(struct net_device * lower_dev,void * lower_state_info)8374 void netdev_lower_state_changed(struct net_device *lower_dev,
8375 				void *lower_state_info)
8376 {
8377 	struct netdev_notifier_changelowerstate_info changelowerstate_info = {
8378 		.info.dev = lower_dev,
8379 	};
8380 
8381 	ASSERT_RTNL();
8382 	changelowerstate_info.lower_state_info = lower_state_info;
8383 	call_netdevice_notifiers_info(NETDEV_CHANGELOWERSTATE,
8384 				      &changelowerstate_info.info);
8385 }
8386 EXPORT_SYMBOL(netdev_lower_state_changed);
8387 
dev_change_rx_flags(struct net_device * dev,int flags)8388 static void dev_change_rx_flags(struct net_device *dev, int flags)
8389 {
8390 	const struct net_device_ops *ops = dev->netdev_ops;
8391 
8392 	if (ops->ndo_change_rx_flags)
8393 		ops->ndo_change_rx_flags(dev, flags);
8394 }
8395 
__dev_set_promiscuity(struct net_device * dev,int inc,bool notify)8396 static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify)
8397 {
8398 	unsigned int old_flags = dev->flags;
8399 	kuid_t uid;
8400 	kgid_t gid;
8401 
8402 	ASSERT_RTNL();
8403 
8404 	dev->flags |= IFF_PROMISC;
8405 	dev->promiscuity += inc;
8406 	if (dev->promiscuity == 0) {
8407 		/*
8408 		 * Avoid overflow.
8409 		 * If inc causes overflow, untouch promisc and return error.
8410 		 */
8411 		if (inc < 0)
8412 			dev->flags &= ~IFF_PROMISC;
8413 		else {
8414 			dev->promiscuity -= inc;
8415 			netdev_warn(dev, "promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n");
8416 			return -EOVERFLOW;
8417 		}
8418 	}
8419 	if (dev->flags != old_flags) {
8420 		netdev_info(dev, "%s promiscuous mode\n",
8421 			    dev->flags & IFF_PROMISC ? "entered" : "left");
8422 		if (audit_enabled) {
8423 			current_uid_gid(&uid, &gid);
8424 			audit_log(audit_context(), GFP_ATOMIC,
8425 				  AUDIT_ANOM_PROMISCUOUS,
8426 				  "dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
8427 				  dev->name, (dev->flags & IFF_PROMISC),
8428 				  (old_flags & IFF_PROMISC),
8429 				  from_kuid(&init_user_ns, audit_get_loginuid(current)),
8430 				  from_kuid(&init_user_ns, uid),
8431 				  from_kgid(&init_user_ns, gid),
8432 				  audit_get_sessionid(current));
8433 		}
8434 
8435 		dev_change_rx_flags(dev, IFF_PROMISC);
8436 	}
8437 	if (notify)
8438 		__dev_notify_flags(dev, old_flags, IFF_PROMISC, 0, NULL);
8439 	return 0;
8440 }
8441 
8442 /**
8443  *	dev_set_promiscuity	- update promiscuity count on a device
8444  *	@dev: device
8445  *	@inc: modifier
8446  *
8447  *	Add or remove promiscuity from a device. While the count in the device
8448  *	remains above zero the interface remains promiscuous. Once it hits zero
8449  *	the device reverts back to normal filtering operation. A negative inc
8450  *	value is used to drop promiscuity on the device.
8451  *	Return 0 if successful or a negative errno code on error.
8452  */
dev_set_promiscuity(struct net_device * dev,int inc)8453 int dev_set_promiscuity(struct net_device *dev, int inc)
8454 {
8455 	unsigned int old_flags = dev->flags;
8456 	int err;
8457 
8458 	err = __dev_set_promiscuity(dev, inc, true);
8459 	if (err < 0)
8460 		return err;
8461 	if (dev->flags != old_flags)
8462 		dev_set_rx_mode(dev);
8463 	return err;
8464 }
8465 EXPORT_SYMBOL(dev_set_promiscuity);
8466 
__dev_set_allmulti(struct net_device * dev,int inc,bool notify)8467 static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify)
8468 {
8469 	unsigned int old_flags = dev->flags, old_gflags = dev->gflags;
8470 
8471 	ASSERT_RTNL();
8472 
8473 	dev->flags |= IFF_ALLMULTI;
8474 	dev->allmulti += inc;
8475 	if (dev->allmulti == 0) {
8476 		/*
8477 		 * Avoid overflow.
8478 		 * If inc causes overflow, untouch allmulti and return error.
8479 		 */
8480 		if (inc < 0)
8481 			dev->flags &= ~IFF_ALLMULTI;
8482 		else {
8483 			dev->allmulti -= inc;
8484 			netdev_warn(dev, "allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n");
8485 			return -EOVERFLOW;
8486 		}
8487 	}
8488 	if (dev->flags ^ old_flags) {
8489 		netdev_info(dev, "%s allmulticast mode\n",
8490 			    dev->flags & IFF_ALLMULTI ? "entered" : "left");
8491 		dev_change_rx_flags(dev, IFF_ALLMULTI);
8492 		dev_set_rx_mode(dev);
8493 		if (notify)
8494 			__dev_notify_flags(dev, old_flags,
8495 					   dev->gflags ^ old_gflags, 0, NULL);
8496 	}
8497 	return 0;
8498 }
8499 
8500 /**
8501  *	dev_set_allmulti	- update allmulti count on a device
8502  *	@dev: device
8503  *	@inc: modifier
8504  *
8505  *	Add or remove reception of all multicast frames to a device. While the
8506  *	count in the device remains above zero the interface remains listening
8507  *	to all interfaces. Once it hits zero the device reverts back to normal
8508  *	filtering operation. A negative @inc value is used to drop the counter
8509  *	when releasing a resource needing all multicasts.
8510  *	Return 0 if successful or a negative errno code on error.
8511  */
8512 
dev_set_allmulti(struct net_device * dev,int inc)8513 int dev_set_allmulti(struct net_device *dev, int inc)
8514 {
8515 	return __dev_set_allmulti(dev, inc, true);
8516 }
8517 EXPORT_SYMBOL(dev_set_allmulti);
8518 
8519 /*
8520  *	Upload unicast and multicast address lists to device and
8521  *	configure RX filtering. When the device doesn't support unicast
8522  *	filtering it is put in promiscuous mode while unicast addresses
8523  *	are present.
8524  */
__dev_set_rx_mode(struct net_device * dev)8525 void __dev_set_rx_mode(struct net_device *dev)
8526 {
8527 	const struct net_device_ops *ops = dev->netdev_ops;
8528 
8529 	/* dev_open will call this function so the list will stay sane. */
8530 	if (!(dev->flags&IFF_UP))
8531 		return;
8532 
8533 	if (!netif_device_present(dev))
8534 		return;
8535 
8536 	if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
8537 		/* Unicast addresses changes may only happen under the rtnl,
8538 		 * therefore calling __dev_set_promiscuity here is safe.
8539 		 */
8540 		if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
8541 			__dev_set_promiscuity(dev, 1, false);
8542 			dev->uc_promisc = true;
8543 		} else if (netdev_uc_empty(dev) && dev->uc_promisc) {
8544 			__dev_set_promiscuity(dev, -1, false);
8545 			dev->uc_promisc = false;
8546 		}
8547 	}
8548 
8549 	if (ops->ndo_set_rx_mode)
8550 		ops->ndo_set_rx_mode(dev);
8551 }
8552 
dev_set_rx_mode(struct net_device * dev)8553 void dev_set_rx_mode(struct net_device *dev)
8554 {
8555 	netif_addr_lock_bh(dev);
8556 	__dev_set_rx_mode(dev);
8557 	netif_addr_unlock_bh(dev);
8558 }
8559 
8560 /**
8561  *	dev_get_flags - get flags reported to userspace
8562  *	@dev: device
8563  *
8564  *	Get the combination of flag bits exported through APIs to userspace.
8565  */
dev_get_flags(const struct net_device * dev)8566 unsigned int dev_get_flags(const struct net_device *dev)
8567 {
8568 	unsigned int flags;
8569 
8570 	flags = (dev->flags & ~(IFF_PROMISC |
8571 				IFF_ALLMULTI |
8572 				IFF_RUNNING |
8573 				IFF_LOWER_UP |
8574 				IFF_DORMANT)) |
8575 		(dev->gflags & (IFF_PROMISC |
8576 				IFF_ALLMULTI));
8577 
8578 	if (netif_running(dev)) {
8579 		if (netif_oper_up(dev))
8580 			flags |= IFF_RUNNING;
8581 		if (netif_carrier_ok(dev))
8582 			flags |= IFF_LOWER_UP;
8583 		if (netif_dormant(dev))
8584 			flags |= IFF_DORMANT;
8585 	}
8586 
8587 	return flags;
8588 }
8589 EXPORT_SYMBOL(dev_get_flags);
8590 
__dev_change_flags(struct net_device * dev,unsigned int flags,struct netlink_ext_ack * extack)8591 int __dev_change_flags(struct net_device *dev, unsigned int flags,
8592 		       struct netlink_ext_ack *extack)
8593 {
8594 	unsigned int old_flags = dev->flags;
8595 	int ret;
8596 
8597 	ASSERT_RTNL();
8598 
8599 	/*
8600 	 *	Set the flags on our device.
8601 	 */
8602 
8603 	dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
8604 			       IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
8605 			       IFF_AUTOMEDIA)) |
8606 		     (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
8607 				    IFF_ALLMULTI));
8608 
8609 	/*
8610 	 *	Load in the correct multicast list now the flags have changed.
8611 	 */
8612 
8613 	if ((old_flags ^ flags) & IFF_MULTICAST)
8614 		dev_change_rx_flags(dev, IFF_MULTICAST);
8615 
8616 	dev_set_rx_mode(dev);
8617 
8618 	/*
8619 	 *	Have we downed the interface. We handle IFF_UP ourselves
8620 	 *	according to user attempts to set it, rather than blindly
8621 	 *	setting it.
8622 	 */
8623 
8624 	ret = 0;
8625 	if ((old_flags ^ flags) & IFF_UP) {
8626 		if (old_flags & IFF_UP)
8627 			__dev_close(dev);
8628 		else
8629 			ret = __dev_open(dev, extack);
8630 	}
8631 
8632 	if ((flags ^ dev->gflags) & IFF_PROMISC) {
8633 		int inc = (flags & IFF_PROMISC) ? 1 : -1;
8634 		unsigned int old_flags = dev->flags;
8635 
8636 		dev->gflags ^= IFF_PROMISC;
8637 
8638 		if (__dev_set_promiscuity(dev, inc, false) >= 0)
8639 			if (dev->flags != old_flags)
8640 				dev_set_rx_mode(dev);
8641 	}
8642 
8643 	/* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
8644 	 * is important. Some (broken) drivers set IFF_PROMISC, when
8645 	 * IFF_ALLMULTI is requested not asking us and not reporting.
8646 	 */
8647 	if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
8648 		int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
8649 
8650 		dev->gflags ^= IFF_ALLMULTI;
8651 		__dev_set_allmulti(dev, inc, false);
8652 	}
8653 
8654 	return ret;
8655 }
8656 
__dev_notify_flags(struct net_device * dev,unsigned int old_flags,unsigned int gchanges,u32 portid,const struct nlmsghdr * nlh)8657 void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
8658 			unsigned int gchanges, u32 portid,
8659 			const struct nlmsghdr *nlh)
8660 {
8661 	unsigned int changes = dev->flags ^ old_flags;
8662 
8663 	if (gchanges)
8664 		rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC, portid, nlh);
8665 
8666 	if (changes & IFF_UP) {
8667 		if (dev->flags & IFF_UP)
8668 			call_netdevice_notifiers(NETDEV_UP, dev);
8669 		else
8670 			call_netdevice_notifiers(NETDEV_DOWN, dev);
8671 	}
8672 
8673 	if (dev->flags & IFF_UP &&
8674 	    (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE))) {
8675 		struct netdev_notifier_change_info change_info = {
8676 			.info = {
8677 				.dev = dev,
8678 			},
8679 			.flags_changed = changes,
8680 		};
8681 
8682 		call_netdevice_notifiers_info(NETDEV_CHANGE, &change_info.info);
8683 	}
8684 }
8685 
8686 /**
8687  *	dev_change_flags - change device settings
8688  *	@dev: device
8689  *	@flags: device state flags
8690  *	@extack: netlink extended ack
8691  *
8692  *	Change settings on device based state flags. The flags are
8693  *	in the userspace exported format.
8694  */
dev_change_flags(struct net_device * dev,unsigned int flags,struct netlink_ext_ack * extack)8695 int dev_change_flags(struct net_device *dev, unsigned int flags,
8696 		     struct netlink_ext_ack *extack)
8697 {
8698 	int ret;
8699 	unsigned int changes, old_flags = dev->flags, old_gflags = dev->gflags;
8700 
8701 	ret = __dev_change_flags(dev, flags, extack);
8702 	if (ret < 0)
8703 		return ret;
8704 
8705 	changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags);
8706 	__dev_notify_flags(dev, old_flags, changes, 0, NULL);
8707 	return ret;
8708 }
8709 EXPORT_SYMBOL(dev_change_flags);
8710 
__dev_set_mtu(struct net_device * dev,int new_mtu)8711 int __dev_set_mtu(struct net_device *dev, int new_mtu)
8712 {
8713 	const struct net_device_ops *ops = dev->netdev_ops;
8714 
8715 	if (ops->ndo_change_mtu)
8716 		return ops->ndo_change_mtu(dev, new_mtu);
8717 
8718 	/* Pairs with all the lockless reads of dev->mtu in the stack */
8719 	WRITE_ONCE(dev->mtu, new_mtu);
8720 	return 0;
8721 }
8722 EXPORT_SYMBOL(__dev_set_mtu);
8723 
dev_validate_mtu(struct net_device * dev,int new_mtu,struct netlink_ext_ack * extack)8724 int dev_validate_mtu(struct net_device *dev, int new_mtu,
8725 		     struct netlink_ext_ack *extack)
8726 {
8727 	/* MTU must be positive, and in range */
8728 	if (new_mtu < 0 || new_mtu < dev->min_mtu) {
8729 		NL_SET_ERR_MSG(extack, "mtu less than device minimum");
8730 		return -EINVAL;
8731 	}
8732 
8733 	if (dev->max_mtu > 0 && new_mtu > dev->max_mtu) {
8734 		NL_SET_ERR_MSG(extack, "mtu greater than device maximum");
8735 		return -EINVAL;
8736 	}
8737 	return 0;
8738 }
8739 
8740 /**
8741  *	dev_set_mtu_ext - Change maximum transfer unit
8742  *	@dev: device
8743  *	@new_mtu: new transfer unit
8744  *	@extack: netlink extended ack
8745  *
8746  *	Change the maximum transfer size of the network device.
8747  */
dev_set_mtu_ext(struct net_device * dev,int new_mtu,struct netlink_ext_ack * extack)8748 int dev_set_mtu_ext(struct net_device *dev, int new_mtu,
8749 		    struct netlink_ext_ack *extack)
8750 {
8751 	int err, orig_mtu;
8752 
8753 	if (new_mtu == dev->mtu)
8754 		return 0;
8755 
8756 	err = dev_validate_mtu(dev, new_mtu, extack);
8757 	if (err)
8758 		return err;
8759 
8760 	if (!netif_device_present(dev))
8761 		return -ENODEV;
8762 
8763 	err = call_netdevice_notifiers(NETDEV_PRECHANGEMTU, dev);
8764 	err = notifier_to_errno(err);
8765 	if (err)
8766 		return err;
8767 
8768 	orig_mtu = dev->mtu;
8769 	err = __dev_set_mtu(dev, new_mtu);
8770 
8771 	if (!err) {
8772 		err = call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8773 						   orig_mtu);
8774 		err = notifier_to_errno(err);
8775 		if (err) {
8776 			/* setting mtu back and notifying everyone again,
8777 			 * so that they have a chance to revert changes.
8778 			 */
8779 			__dev_set_mtu(dev, orig_mtu);
8780 			call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8781 						     new_mtu);
8782 		}
8783 	}
8784 	return err;
8785 }
8786 
dev_set_mtu(struct net_device * dev,int new_mtu)8787 int dev_set_mtu(struct net_device *dev, int new_mtu)
8788 {
8789 	struct netlink_ext_ack extack;
8790 	int err;
8791 
8792 	memset(&extack, 0, sizeof(extack));
8793 	err = dev_set_mtu_ext(dev, new_mtu, &extack);
8794 	if (err && extack._msg)
8795 		net_err_ratelimited("%s: %s\n", dev->name, extack._msg);
8796 	return err;
8797 }
8798 EXPORT_SYMBOL(dev_set_mtu);
8799 
8800 /**
8801  *	dev_change_tx_queue_len - Change TX queue length of a netdevice
8802  *	@dev: device
8803  *	@new_len: new tx queue length
8804  */
dev_change_tx_queue_len(struct net_device * dev,unsigned long new_len)8805 int dev_change_tx_queue_len(struct net_device *dev, unsigned long new_len)
8806 {
8807 	unsigned int orig_len = dev->tx_queue_len;
8808 	int res;
8809 
8810 	if (new_len != (unsigned int)new_len)
8811 		return -ERANGE;
8812 
8813 	if (new_len != orig_len) {
8814 		dev->tx_queue_len = new_len;
8815 		res = call_netdevice_notifiers(NETDEV_CHANGE_TX_QUEUE_LEN, dev);
8816 		res = notifier_to_errno(res);
8817 		if (res)
8818 			goto err_rollback;
8819 		res = dev_qdisc_change_tx_queue_len(dev);
8820 		if (res)
8821 			goto err_rollback;
8822 	}
8823 
8824 	return 0;
8825 
8826 err_rollback:
8827 	netdev_err(dev, "refused to change device tx_queue_len\n");
8828 	dev->tx_queue_len = orig_len;
8829 	return res;
8830 }
8831 
8832 /**
8833  *	dev_set_group - Change group this device belongs to
8834  *	@dev: device
8835  *	@new_group: group this device should belong to
8836  */
dev_set_group(struct net_device * dev,int new_group)8837 void dev_set_group(struct net_device *dev, int new_group)
8838 {
8839 	dev->group = new_group;
8840 }
8841 
8842 /**
8843  *	dev_pre_changeaddr_notify - Call NETDEV_PRE_CHANGEADDR.
8844  *	@dev: device
8845  *	@addr: new address
8846  *	@extack: netlink extended ack
8847  */
dev_pre_changeaddr_notify(struct net_device * dev,const char * addr,struct netlink_ext_ack * extack)8848 int dev_pre_changeaddr_notify(struct net_device *dev, const char *addr,
8849 			      struct netlink_ext_ack *extack)
8850 {
8851 	struct netdev_notifier_pre_changeaddr_info info = {
8852 		.info.dev = dev,
8853 		.info.extack = extack,
8854 		.dev_addr = addr,
8855 	};
8856 	int rc;
8857 
8858 	rc = call_netdevice_notifiers_info(NETDEV_PRE_CHANGEADDR, &info.info);
8859 	return notifier_to_errno(rc);
8860 }
8861 EXPORT_SYMBOL(dev_pre_changeaddr_notify);
8862 
8863 /**
8864  *	dev_set_mac_address - Change Media Access Control Address
8865  *	@dev: device
8866  *	@sa: new address
8867  *	@extack: netlink extended ack
8868  *
8869  *	Change the hardware (MAC) address of the device
8870  */
dev_set_mac_address(struct net_device * dev,struct sockaddr * sa,struct netlink_ext_ack * extack)8871 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa,
8872 			struct netlink_ext_ack *extack)
8873 {
8874 	const struct net_device_ops *ops = dev->netdev_ops;
8875 	int err;
8876 
8877 	if (!ops->ndo_set_mac_address)
8878 		return -EOPNOTSUPP;
8879 	if (sa->sa_family != dev->type)
8880 		return -EINVAL;
8881 	if (!netif_device_present(dev))
8882 		return -ENODEV;
8883 	err = dev_pre_changeaddr_notify(dev, sa->sa_data, extack);
8884 	if (err)
8885 		return err;
8886 	if (memcmp(dev->dev_addr, sa->sa_data, dev->addr_len)) {
8887 		err = ops->ndo_set_mac_address(dev, sa);
8888 		if (err)
8889 			return err;
8890 	}
8891 	dev->addr_assign_type = NET_ADDR_SET;
8892 	call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
8893 	add_device_randomness(dev->dev_addr, dev->addr_len);
8894 	return 0;
8895 }
8896 EXPORT_SYMBOL(dev_set_mac_address);
8897 
8898 static DECLARE_RWSEM(dev_addr_sem);
8899 
dev_set_mac_address_user(struct net_device * dev,struct sockaddr * sa,struct netlink_ext_ack * extack)8900 int dev_set_mac_address_user(struct net_device *dev, struct sockaddr *sa,
8901 			     struct netlink_ext_ack *extack)
8902 {
8903 	int ret;
8904 
8905 	down_write(&dev_addr_sem);
8906 	ret = dev_set_mac_address(dev, sa, extack);
8907 	up_write(&dev_addr_sem);
8908 	return ret;
8909 }
8910 EXPORT_SYMBOL(dev_set_mac_address_user);
8911 
dev_get_mac_address(struct sockaddr * sa,struct net * net,char * dev_name)8912 int dev_get_mac_address(struct sockaddr *sa, struct net *net, char *dev_name)
8913 {
8914 	size_t size = sizeof(sa->sa_data_min);
8915 	struct net_device *dev;
8916 	int ret = 0;
8917 
8918 	down_read(&dev_addr_sem);
8919 	rcu_read_lock();
8920 
8921 	dev = dev_get_by_name_rcu(net, dev_name);
8922 	if (!dev) {
8923 		ret = -ENODEV;
8924 		goto unlock;
8925 	}
8926 	if (!dev->addr_len)
8927 		memset(sa->sa_data, 0, size);
8928 	else
8929 		memcpy(sa->sa_data, dev->dev_addr,
8930 		       min_t(size_t, size, dev->addr_len));
8931 	sa->sa_family = dev->type;
8932 
8933 unlock:
8934 	rcu_read_unlock();
8935 	up_read(&dev_addr_sem);
8936 	return ret;
8937 }
8938 EXPORT_SYMBOL(dev_get_mac_address);
8939 
8940 /**
8941  *	dev_change_carrier - Change device carrier
8942  *	@dev: device
8943  *	@new_carrier: new value
8944  *
8945  *	Change device carrier
8946  */
dev_change_carrier(struct net_device * dev,bool new_carrier)8947 int dev_change_carrier(struct net_device *dev, bool new_carrier)
8948 {
8949 	const struct net_device_ops *ops = dev->netdev_ops;
8950 
8951 	if (!ops->ndo_change_carrier)
8952 		return -EOPNOTSUPP;
8953 	if (!netif_device_present(dev))
8954 		return -ENODEV;
8955 	return ops->ndo_change_carrier(dev, new_carrier);
8956 }
8957 
8958 /**
8959  *	dev_get_phys_port_id - Get device physical port ID
8960  *	@dev: device
8961  *	@ppid: port ID
8962  *
8963  *	Get device physical port ID
8964  */
dev_get_phys_port_id(struct net_device * dev,struct netdev_phys_item_id * ppid)8965 int dev_get_phys_port_id(struct net_device *dev,
8966 			 struct netdev_phys_item_id *ppid)
8967 {
8968 	const struct net_device_ops *ops = dev->netdev_ops;
8969 
8970 	if (!ops->ndo_get_phys_port_id)
8971 		return -EOPNOTSUPP;
8972 	return ops->ndo_get_phys_port_id(dev, ppid);
8973 }
8974 
8975 /**
8976  *	dev_get_phys_port_name - Get device physical port name
8977  *	@dev: device
8978  *	@name: port name
8979  *	@len: limit of bytes to copy to name
8980  *
8981  *	Get device physical port name
8982  */
dev_get_phys_port_name(struct net_device * dev,char * name,size_t len)8983 int dev_get_phys_port_name(struct net_device *dev,
8984 			   char *name, size_t len)
8985 {
8986 	const struct net_device_ops *ops = dev->netdev_ops;
8987 	int err;
8988 
8989 	if (ops->ndo_get_phys_port_name) {
8990 		err = ops->ndo_get_phys_port_name(dev, name, len);
8991 		if (err != -EOPNOTSUPP)
8992 			return err;
8993 	}
8994 	return devlink_compat_phys_port_name_get(dev, name, len);
8995 }
8996 
8997 /**
8998  *	dev_get_port_parent_id - Get the device's port parent identifier
8999  *	@dev: network device
9000  *	@ppid: pointer to a storage for the port's parent identifier
9001  *	@recurse: allow/disallow recursion to lower devices
9002  *
9003  *	Get the devices's port parent identifier
9004  */
dev_get_port_parent_id(struct net_device * dev,struct netdev_phys_item_id * ppid,bool recurse)9005 int dev_get_port_parent_id(struct net_device *dev,
9006 			   struct netdev_phys_item_id *ppid,
9007 			   bool recurse)
9008 {
9009 	const struct net_device_ops *ops = dev->netdev_ops;
9010 	struct netdev_phys_item_id first = { };
9011 	struct net_device *lower_dev;
9012 	struct list_head *iter;
9013 	int err;
9014 
9015 	if (ops->ndo_get_port_parent_id) {
9016 		err = ops->ndo_get_port_parent_id(dev, ppid);
9017 		if (err != -EOPNOTSUPP)
9018 			return err;
9019 	}
9020 
9021 	err = devlink_compat_switch_id_get(dev, ppid);
9022 	if (!recurse || err != -EOPNOTSUPP)
9023 		return err;
9024 
9025 	netdev_for_each_lower_dev(dev, lower_dev, iter) {
9026 		err = dev_get_port_parent_id(lower_dev, ppid, true);
9027 		if (err)
9028 			break;
9029 		if (!first.id_len)
9030 			first = *ppid;
9031 		else if (memcmp(&first, ppid, sizeof(*ppid)))
9032 			return -EOPNOTSUPP;
9033 	}
9034 
9035 	return err;
9036 }
9037 EXPORT_SYMBOL(dev_get_port_parent_id);
9038 
9039 /**
9040  *	netdev_port_same_parent_id - Indicate if two network devices have
9041  *	the same port parent identifier
9042  *	@a: first network device
9043  *	@b: second network device
9044  */
netdev_port_same_parent_id(struct net_device * a,struct net_device * b)9045 bool netdev_port_same_parent_id(struct net_device *a, struct net_device *b)
9046 {
9047 	struct netdev_phys_item_id a_id = { };
9048 	struct netdev_phys_item_id b_id = { };
9049 
9050 	if (dev_get_port_parent_id(a, &a_id, true) ||
9051 	    dev_get_port_parent_id(b, &b_id, true))
9052 		return false;
9053 
9054 	return netdev_phys_item_id_same(&a_id, &b_id);
9055 }
9056 EXPORT_SYMBOL(netdev_port_same_parent_id);
9057 
9058 /**
9059  *	dev_change_proto_down - set carrier according to proto_down.
9060  *
9061  *	@dev: device
9062  *	@proto_down: new value
9063  */
dev_change_proto_down(struct net_device * dev,bool proto_down)9064 int dev_change_proto_down(struct net_device *dev, bool proto_down)
9065 {
9066 	if (!(dev->priv_flags & IFF_CHANGE_PROTO_DOWN))
9067 		return -EOPNOTSUPP;
9068 	if (!netif_device_present(dev))
9069 		return -ENODEV;
9070 	if (proto_down)
9071 		netif_carrier_off(dev);
9072 	else
9073 		netif_carrier_on(dev);
9074 	dev->proto_down = proto_down;
9075 	return 0;
9076 }
9077 
9078 /**
9079  *	dev_change_proto_down_reason - proto down reason
9080  *
9081  *	@dev: device
9082  *	@mask: proto down mask
9083  *	@value: proto down value
9084  */
dev_change_proto_down_reason(struct net_device * dev,unsigned long mask,u32 value)9085 void dev_change_proto_down_reason(struct net_device *dev, unsigned long mask,
9086 				  u32 value)
9087 {
9088 	int b;
9089 
9090 	if (!mask) {
9091 		dev->proto_down_reason = value;
9092 	} else {
9093 		for_each_set_bit(b, &mask, 32) {
9094 			if (value & (1 << b))
9095 				dev->proto_down_reason |= BIT(b);
9096 			else
9097 				dev->proto_down_reason &= ~BIT(b);
9098 		}
9099 	}
9100 }
9101 
9102 struct bpf_xdp_link {
9103 	struct bpf_link link;
9104 	struct net_device *dev; /* protected by rtnl_lock, no refcnt held */
9105 	int flags;
9106 };
9107 
dev_xdp_mode(struct net_device * dev,u32 flags)9108 static enum bpf_xdp_mode dev_xdp_mode(struct net_device *dev, u32 flags)
9109 {
9110 	if (flags & XDP_FLAGS_HW_MODE)
9111 		return XDP_MODE_HW;
9112 	if (flags & XDP_FLAGS_DRV_MODE)
9113 		return XDP_MODE_DRV;
9114 	if (flags & XDP_FLAGS_SKB_MODE)
9115 		return XDP_MODE_SKB;
9116 	return dev->netdev_ops->ndo_bpf ? XDP_MODE_DRV : XDP_MODE_SKB;
9117 }
9118 
dev_xdp_bpf_op(struct net_device * dev,enum bpf_xdp_mode mode)9119 static bpf_op_t dev_xdp_bpf_op(struct net_device *dev, enum bpf_xdp_mode mode)
9120 {
9121 	switch (mode) {
9122 	case XDP_MODE_SKB:
9123 		return generic_xdp_install;
9124 	case XDP_MODE_DRV:
9125 	case XDP_MODE_HW:
9126 		return dev->netdev_ops->ndo_bpf;
9127 	default:
9128 		return NULL;
9129 	}
9130 }
9131 
dev_xdp_link(struct net_device * dev,enum bpf_xdp_mode mode)9132 static struct bpf_xdp_link *dev_xdp_link(struct net_device *dev,
9133 					 enum bpf_xdp_mode mode)
9134 {
9135 	return dev->xdp_state[mode].link;
9136 }
9137 
dev_xdp_prog(struct net_device * dev,enum bpf_xdp_mode mode)9138 static struct bpf_prog *dev_xdp_prog(struct net_device *dev,
9139 				     enum bpf_xdp_mode mode)
9140 {
9141 	struct bpf_xdp_link *link = dev_xdp_link(dev, mode);
9142 
9143 	if (link)
9144 		return link->link.prog;
9145 	return dev->xdp_state[mode].prog;
9146 }
9147 
dev_xdp_prog_count(struct net_device * dev)9148 u8 dev_xdp_prog_count(struct net_device *dev)
9149 {
9150 	u8 count = 0;
9151 	int i;
9152 
9153 	for (i = 0; i < __MAX_XDP_MODE; i++)
9154 		if (dev->xdp_state[i].prog || dev->xdp_state[i].link)
9155 			count++;
9156 	return count;
9157 }
9158 EXPORT_SYMBOL_GPL(dev_xdp_prog_count);
9159 
dev_xdp_prog_id(struct net_device * dev,enum bpf_xdp_mode mode)9160 u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode)
9161 {
9162 	struct bpf_prog *prog = dev_xdp_prog(dev, mode);
9163 
9164 	return prog ? prog->aux->id : 0;
9165 }
9166 
dev_xdp_set_link(struct net_device * dev,enum bpf_xdp_mode mode,struct bpf_xdp_link * link)9167 static void dev_xdp_set_link(struct net_device *dev, enum bpf_xdp_mode mode,
9168 			     struct bpf_xdp_link *link)
9169 {
9170 	dev->xdp_state[mode].link = link;
9171 	dev->xdp_state[mode].prog = NULL;
9172 }
9173 
dev_xdp_set_prog(struct net_device * dev,enum bpf_xdp_mode mode,struct bpf_prog * prog)9174 static void dev_xdp_set_prog(struct net_device *dev, enum bpf_xdp_mode mode,
9175 			     struct bpf_prog *prog)
9176 {
9177 	dev->xdp_state[mode].link = NULL;
9178 	dev->xdp_state[mode].prog = prog;
9179 }
9180 
dev_xdp_install(struct net_device * dev,enum bpf_xdp_mode mode,bpf_op_t bpf_op,struct netlink_ext_ack * extack,u32 flags,struct bpf_prog * prog)9181 static int dev_xdp_install(struct net_device *dev, enum bpf_xdp_mode mode,
9182 			   bpf_op_t bpf_op, struct netlink_ext_ack *extack,
9183 			   u32 flags, struct bpf_prog *prog)
9184 {
9185 	struct netdev_bpf xdp;
9186 	int err;
9187 
9188 	memset(&xdp, 0, sizeof(xdp));
9189 	xdp.command = mode == XDP_MODE_HW ? XDP_SETUP_PROG_HW : XDP_SETUP_PROG;
9190 	xdp.extack = extack;
9191 	xdp.flags = flags;
9192 	xdp.prog = prog;
9193 
9194 	/* Drivers assume refcnt is already incremented (i.e, prog pointer is
9195 	 * "moved" into driver), so they don't increment it on their own, but
9196 	 * they do decrement refcnt when program is detached or replaced.
9197 	 * Given net_device also owns link/prog, we need to bump refcnt here
9198 	 * to prevent drivers from underflowing it.
9199 	 */
9200 	if (prog)
9201 		bpf_prog_inc(prog);
9202 	err = bpf_op(dev, &xdp);
9203 	if (err) {
9204 		if (prog)
9205 			bpf_prog_put(prog);
9206 		return err;
9207 	}
9208 
9209 	if (mode != XDP_MODE_HW)
9210 		bpf_prog_change_xdp(dev_xdp_prog(dev, mode), prog);
9211 
9212 	return 0;
9213 }
9214 
dev_xdp_uninstall(struct net_device * dev)9215 static void dev_xdp_uninstall(struct net_device *dev)
9216 {
9217 	struct bpf_xdp_link *link;
9218 	struct bpf_prog *prog;
9219 	enum bpf_xdp_mode mode;
9220 	bpf_op_t bpf_op;
9221 
9222 	ASSERT_RTNL();
9223 
9224 	for (mode = XDP_MODE_SKB; mode < __MAX_XDP_MODE; mode++) {
9225 		prog = dev_xdp_prog(dev, mode);
9226 		if (!prog)
9227 			continue;
9228 
9229 		bpf_op = dev_xdp_bpf_op(dev, mode);
9230 		if (!bpf_op)
9231 			continue;
9232 
9233 		WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9234 
9235 		/* auto-detach link from net device */
9236 		link = dev_xdp_link(dev, mode);
9237 		if (link)
9238 			link->dev = NULL;
9239 		else
9240 			bpf_prog_put(prog);
9241 
9242 		dev_xdp_set_link(dev, mode, NULL);
9243 	}
9244 }
9245 
dev_xdp_attach(struct net_device * dev,struct netlink_ext_ack * extack,struct bpf_xdp_link * link,struct bpf_prog * new_prog,struct bpf_prog * old_prog,u32 flags)9246 static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack,
9247 			  struct bpf_xdp_link *link, struct bpf_prog *new_prog,
9248 			  struct bpf_prog *old_prog, u32 flags)
9249 {
9250 	unsigned int num_modes = hweight32(flags & XDP_FLAGS_MODES);
9251 	struct bpf_prog *cur_prog;
9252 	struct net_device *upper;
9253 	struct list_head *iter;
9254 	enum bpf_xdp_mode mode;
9255 	bpf_op_t bpf_op;
9256 	int err;
9257 
9258 	ASSERT_RTNL();
9259 
9260 	/* either link or prog attachment, never both */
9261 	if (link && (new_prog || old_prog))
9262 		return -EINVAL;
9263 	/* link supports only XDP mode flags */
9264 	if (link && (flags & ~XDP_FLAGS_MODES)) {
9265 		NL_SET_ERR_MSG(extack, "Invalid XDP flags for BPF link attachment");
9266 		return -EINVAL;
9267 	}
9268 	/* just one XDP mode bit should be set, zero defaults to drv/skb mode */
9269 	if (num_modes > 1) {
9270 		NL_SET_ERR_MSG(extack, "Only one XDP mode flag can be set");
9271 		return -EINVAL;
9272 	}
9273 	/* avoid ambiguity if offload + drv/skb mode progs are both loaded */
9274 	if (!num_modes && dev_xdp_prog_count(dev) > 1) {
9275 		NL_SET_ERR_MSG(extack,
9276 			       "More than one program loaded, unset mode is ambiguous");
9277 		return -EINVAL;
9278 	}
9279 	/* old_prog != NULL implies XDP_FLAGS_REPLACE is set */
9280 	if (old_prog && !(flags & XDP_FLAGS_REPLACE)) {
9281 		NL_SET_ERR_MSG(extack, "XDP_FLAGS_REPLACE is not specified");
9282 		return -EINVAL;
9283 	}
9284 
9285 	mode = dev_xdp_mode(dev, flags);
9286 	/* can't replace attached link */
9287 	if (dev_xdp_link(dev, mode)) {
9288 		NL_SET_ERR_MSG(extack, "Can't replace active BPF XDP link");
9289 		return -EBUSY;
9290 	}
9291 
9292 	/* don't allow if an upper device already has a program */
9293 	netdev_for_each_upper_dev_rcu(dev, upper, iter) {
9294 		if (dev_xdp_prog_count(upper) > 0) {
9295 			NL_SET_ERR_MSG(extack, "Cannot attach when an upper device already has a program");
9296 			return -EEXIST;
9297 		}
9298 	}
9299 
9300 	cur_prog = dev_xdp_prog(dev, mode);
9301 	/* can't replace attached prog with link */
9302 	if (link && cur_prog) {
9303 		NL_SET_ERR_MSG(extack, "Can't replace active XDP program with BPF link");
9304 		return -EBUSY;
9305 	}
9306 	if ((flags & XDP_FLAGS_REPLACE) && cur_prog != old_prog) {
9307 		NL_SET_ERR_MSG(extack, "Active program does not match expected");
9308 		return -EEXIST;
9309 	}
9310 
9311 	/* put effective new program into new_prog */
9312 	if (link)
9313 		new_prog = link->link.prog;
9314 
9315 	if (new_prog) {
9316 		bool offload = mode == XDP_MODE_HW;
9317 		enum bpf_xdp_mode other_mode = mode == XDP_MODE_SKB
9318 					       ? XDP_MODE_DRV : XDP_MODE_SKB;
9319 
9320 		if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && cur_prog) {
9321 			NL_SET_ERR_MSG(extack, "XDP program already attached");
9322 			return -EBUSY;
9323 		}
9324 		if (!offload && dev_xdp_prog(dev, other_mode)) {
9325 			NL_SET_ERR_MSG(extack, "Native and generic XDP can't be active at the same time");
9326 			return -EEXIST;
9327 		}
9328 		if (!offload && bpf_prog_is_offloaded(new_prog->aux)) {
9329 			NL_SET_ERR_MSG(extack, "Using offloaded program without HW_MODE flag is not supported");
9330 			return -EINVAL;
9331 		}
9332 		if (bpf_prog_is_dev_bound(new_prog->aux) && !bpf_offload_dev_match(new_prog, dev)) {
9333 			NL_SET_ERR_MSG(extack, "Program bound to different device");
9334 			return -EINVAL;
9335 		}
9336 		if (new_prog->expected_attach_type == BPF_XDP_DEVMAP) {
9337 			NL_SET_ERR_MSG(extack, "BPF_XDP_DEVMAP programs can not be attached to a device");
9338 			return -EINVAL;
9339 		}
9340 		if (new_prog->expected_attach_type == BPF_XDP_CPUMAP) {
9341 			NL_SET_ERR_MSG(extack, "BPF_XDP_CPUMAP programs can not be attached to a device");
9342 			return -EINVAL;
9343 		}
9344 	}
9345 
9346 	/* don't call drivers if the effective program didn't change */
9347 	if (new_prog != cur_prog) {
9348 		bpf_op = dev_xdp_bpf_op(dev, mode);
9349 		if (!bpf_op) {
9350 			NL_SET_ERR_MSG(extack, "Underlying driver does not support XDP in native mode");
9351 			return -EOPNOTSUPP;
9352 		}
9353 
9354 		err = dev_xdp_install(dev, mode, bpf_op, extack, flags, new_prog);
9355 		if (err)
9356 			return err;
9357 	}
9358 
9359 	if (link)
9360 		dev_xdp_set_link(dev, mode, link);
9361 	else
9362 		dev_xdp_set_prog(dev, mode, new_prog);
9363 	if (cur_prog)
9364 		bpf_prog_put(cur_prog);
9365 
9366 	return 0;
9367 }
9368 
dev_xdp_attach_link(struct net_device * dev,struct netlink_ext_ack * extack,struct bpf_xdp_link * link)9369 static int dev_xdp_attach_link(struct net_device *dev,
9370 			       struct netlink_ext_ack *extack,
9371 			       struct bpf_xdp_link *link)
9372 {
9373 	return dev_xdp_attach(dev, extack, link, NULL, NULL, link->flags);
9374 }
9375 
dev_xdp_detach_link(struct net_device * dev,struct netlink_ext_ack * extack,struct bpf_xdp_link * link)9376 static int dev_xdp_detach_link(struct net_device *dev,
9377 			       struct netlink_ext_ack *extack,
9378 			       struct bpf_xdp_link *link)
9379 {
9380 	enum bpf_xdp_mode mode;
9381 	bpf_op_t bpf_op;
9382 
9383 	ASSERT_RTNL();
9384 
9385 	mode = dev_xdp_mode(dev, link->flags);
9386 	if (dev_xdp_link(dev, mode) != link)
9387 		return -EINVAL;
9388 
9389 	bpf_op = dev_xdp_bpf_op(dev, mode);
9390 	WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9391 	dev_xdp_set_link(dev, mode, NULL);
9392 	return 0;
9393 }
9394 
bpf_xdp_link_release(struct bpf_link * link)9395 static void bpf_xdp_link_release(struct bpf_link *link)
9396 {
9397 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9398 
9399 	rtnl_lock();
9400 
9401 	/* if racing with net_device's tear down, xdp_link->dev might be
9402 	 * already NULL, in which case link was already auto-detached
9403 	 */
9404 	if (xdp_link->dev) {
9405 		WARN_ON(dev_xdp_detach_link(xdp_link->dev, NULL, xdp_link));
9406 		xdp_link->dev = NULL;
9407 	}
9408 
9409 	rtnl_unlock();
9410 }
9411 
bpf_xdp_link_detach(struct bpf_link * link)9412 static int bpf_xdp_link_detach(struct bpf_link *link)
9413 {
9414 	bpf_xdp_link_release(link);
9415 	return 0;
9416 }
9417 
bpf_xdp_link_dealloc(struct bpf_link * link)9418 static void bpf_xdp_link_dealloc(struct bpf_link *link)
9419 {
9420 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9421 
9422 	kfree(xdp_link);
9423 }
9424 
bpf_xdp_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)9425 static void bpf_xdp_link_show_fdinfo(const struct bpf_link *link,
9426 				     struct seq_file *seq)
9427 {
9428 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9429 	u32 ifindex = 0;
9430 
9431 	rtnl_lock();
9432 	if (xdp_link->dev)
9433 		ifindex = xdp_link->dev->ifindex;
9434 	rtnl_unlock();
9435 
9436 	seq_printf(seq, "ifindex:\t%u\n", ifindex);
9437 }
9438 
bpf_xdp_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)9439 static int bpf_xdp_link_fill_link_info(const struct bpf_link *link,
9440 				       struct bpf_link_info *info)
9441 {
9442 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9443 	u32 ifindex = 0;
9444 
9445 	rtnl_lock();
9446 	if (xdp_link->dev)
9447 		ifindex = xdp_link->dev->ifindex;
9448 	rtnl_unlock();
9449 
9450 	info->xdp.ifindex = ifindex;
9451 	return 0;
9452 }
9453 
bpf_xdp_link_update(struct bpf_link * link,struct bpf_prog * new_prog,struct bpf_prog * old_prog)9454 static int bpf_xdp_link_update(struct bpf_link *link, struct bpf_prog *new_prog,
9455 			       struct bpf_prog *old_prog)
9456 {
9457 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9458 	enum bpf_xdp_mode mode;
9459 	bpf_op_t bpf_op;
9460 	int err = 0;
9461 
9462 	rtnl_lock();
9463 
9464 	/* link might have been auto-released already, so fail */
9465 	if (!xdp_link->dev) {
9466 		err = -ENOLINK;
9467 		goto out_unlock;
9468 	}
9469 
9470 	if (old_prog && link->prog != old_prog) {
9471 		err = -EPERM;
9472 		goto out_unlock;
9473 	}
9474 	old_prog = link->prog;
9475 	if (old_prog->type != new_prog->type ||
9476 	    old_prog->expected_attach_type != new_prog->expected_attach_type) {
9477 		err = -EINVAL;
9478 		goto out_unlock;
9479 	}
9480 
9481 	if (old_prog == new_prog) {
9482 		/* no-op, don't disturb drivers */
9483 		bpf_prog_put(new_prog);
9484 		goto out_unlock;
9485 	}
9486 
9487 	mode = dev_xdp_mode(xdp_link->dev, xdp_link->flags);
9488 	bpf_op = dev_xdp_bpf_op(xdp_link->dev, mode);
9489 	err = dev_xdp_install(xdp_link->dev, mode, bpf_op, NULL,
9490 			      xdp_link->flags, new_prog);
9491 	if (err)
9492 		goto out_unlock;
9493 
9494 	old_prog = xchg(&link->prog, new_prog);
9495 	bpf_prog_put(old_prog);
9496 
9497 out_unlock:
9498 	rtnl_unlock();
9499 	return err;
9500 }
9501 
9502 static const struct bpf_link_ops bpf_xdp_link_lops = {
9503 	.release = bpf_xdp_link_release,
9504 	.dealloc = bpf_xdp_link_dealloc,
9505 	.detach = bpf_xdp_link_detach,
9506 	.show_fdinfo = bpf_xdp_link_show_fdinfo,
9507 	.fill_link_info = bpf_xdp_link_fill_link_info,
9508 	.update_prog = bpf_xdp_link_update,
9509 };
9510 
bpf_xdp_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)9511 int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
9512 {
9513 	struct net *net = current->nsproxy->net_ns;
9514 	struct bpf_link_primer link_primer;
9515 	struct netlink_ext_ack extack = {};
9516 	struct bpf_xdp_link *link;
9517 	struct net_device *dev;
9518 	int err, fd;
9519 
9520 	rtnl_lock();
9521 	dev = dev_get_by_index(net, attr->link_create.target_ifindex);
9522 	if (!dev) {
9523 		rtnl_unlock();
9524 		return -EINVAL;
9525 	}
9526 
9527 	link = kzalloc(sizeof(*link), GFP_USER);
9528 	if (!link) {
9529 		err = -ENOMEM;
9530 		goto unlock;
9531 	}
9532 
9533 	bpf_link_init(&link->link, BPF_LINK_TYPE_XDP, &bpf_xdp_link_lops, prog);
9534 	link->dev = dev;
9535 	link->flags = attr->link_create.flags;
9536 
9537 	err = bpf_link_prime(&link->link, &link_primer);
9538 	if (err) {
9539 		kfree(link);
9540 		goto unlock;
9541 	}
9542 
9543 	err = dev_xdp_attach_link(dev, &extack, link);
9544 	rtnl_unlock();
9545 
9546 	if (err) {
9547 		link->dev = NULL;
9548 		bpf_link_cleanup(&link_primer);
9549 		trace_bpf_xdp_link_attach_failed(extack._msg);
9550 		goto out_put_dev;
9551 	}
9552 
9553 	fd = bpf_link_settle(&link_primer);
9554 	/* link itself doesn't hold dev's refcnt to not complicate shutdown */
9555 	dev_put(dev);
9556 	return fd;
9557 
9558 unlock:
9559 	rtnl_unlock();
9560 
9561 out_put_dev:
9562 	dev_put(dev);
9563 	return err;
9564 }
9565 
9566 /**
9567  *	dev_change_xdp_fd - set or clear a bpf program for a device rx path
9568  *	@dev: device
9569  *	@extack: netlink extended ack
9570  *	@fd: new program fd or negative value to clear
9571  *	@expected_fd: old program fd that userspace expects to replace or clear
9572  *	@flags: xdp-related flags
9573  *
9574  *	Set or clear a bpf program for a device
9575  */
dev_change_xdp_fd(struct net_device * dev,struct netlink_ext_ack * extack,int fd,int expected_fd,u32 flags)9576 int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
9577 		      int fd, int expected_fd, u32 flags)
9578 {
9579 	enum bpf_xdp_mode mode = dev_xdp_mode(dev, flags);
9580 	struct bpf_prog *new_prog = NULL, *old_prog = NULL;
9581 	int err;
9582 
9583 	ASSERT_RTNL();
9584 
9585 	if (fd >= 0) {
9586 		new_prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP,
9587 						 mode != XDP_MODE_SKB);
9588 		if (IS_ERR(new_prog))
9589 			return PTR_ERR(new_prog);
9590 	}
9591 
9592 	if (expected_fd >= 0) {
9593 		old_prog = bpf_prog_get_type_dev(expected_fd, BPF_PROG_TYPE_XDP,
9594 						 mode != XDP_MODE_SKB);
9595 		if (IS_ERR(old_prog)) {
9596 			err = PTR_ERR(old_prog);
9597 			old_prog = NULL;
9598 			goto err_out;
9599 		}
9600 	}
9601 
9602 	err = dev_xdp_attach(dev, extack, NULL, new_prog, old_prog, flags);
9603 
9604 err_out:
9605 	if (err && new_prog)
9606 		bpf_prog_put(new_prog);
9607 	if (old_prog)
9608 		bpf_prog_put(old_prog);
9609 	return err;
9610 }
9611 
9612 /**
9613  * dev_index_reserve() - allocate an ifindex in a namespace
9614  * @net: the applicable net namespace
9615  * @ifindex: requested ifindex, pass %0 to get one allocated
9616  *
9617  * Allocate a ifindex for a new device. Caller must either use the ifindex
9618  * to store the device (via list_netdevice()) or call dev_index_release()
9619  * to give the index up.
9620  *
9621  * Return: a suitable unique value for a new device interface number or -errno.
9622  */
dev_index_reserve(struct net * net,u32 ifindex)9623 static int dev_index_reserve(struct net *net, u32 ifindex)
9624 {
9625 	int err;
9626 
9627 	if (ifindex > INT_MAX) {
9628 		DEBUG_NET_WARN_ON_ONCE(1);
9629 		return -EINVAL;
9630 	}
9631 
9632 	if (!ifindex)
9633 		err = xa_alloc_cyclic(&net->dev_by_index, &ifindex, NULL,
9634 				      xa_limit_31b, &net->ifindex, GFP_KERNEL);
9635 	else
9636 		err = xa_insert(&net->dev_by_index, ifindex, NULL, GFP_KERNEL);
9637 	if (err < 0)
9638 		return err;
9639 
9640 	return ifindex;
9641 }
9642 
dev_index_release(struct net * net,int ifindex)9643 static void dev_index_release(struct net *net, int ifindex)
9644 {
9645 	/* Expect only unused indexes, unlist_netdevice() removes the used */
9646 	WARN_ON(xa_erase(&net->dev_by_index, ifindex));
9647 }
9648 
9649 /* Delayed registration/unregisteration */
9650 LIST_HEAD(net_todo_list);
9651 DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq);
9652 
net_set_todo(struct net_device * dev)9653 static void net_set_todo(struct net_device *dev)
9654 {
9655 	list_add_tail(&dev->todo_list, &net_todo_list);
9656 	atomic_inc(&dev_net(dev)->dev_unreg_count);
9657 }
9658 
netdev_sync_upper_features(struct net_device * lower,struct net_device * upper,netdev_features_t features)9659 static netdev_features_t netdev_sync_upper_features(struct net_device *lower,
9660 	struct net_device *upper, netdev_features_t features)
9661 {
9662 	netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9663 	netdev_features_t feature;
9664 	int feature_bit;
9665 
9666 	for_each_netdev_feature(upper_disables, feature_bit) {
9667 		feature = __NETIF_F_BIT(feature_bit);
9668 		if (!(upper->wanted_features & feature)
9669 		    && (features & feature)) {
9670 			netdev_dbg(lower, "Dropping feature %pNF, upper dev %s has it off.\n",
9671 				   &feature, upper->name);
9672 			features &= ~feature;
9673 		}
9674 	}
9675 
9676 	return features;
9677 }
9678 
netdev_sync_lower_features(struct net_device * upper,struct net_device * lower,netdev_features_t features)9679 static void netdev_sync_lower_features(struct net_device *upper,
9680 	struct net_device *lower, netdev_features_t features)
9681 {
9682 	netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9683 	netdev_features_t feature;
9684 	int feature_bit;
9685 
9686 	for_each_netdev_feature(upper_disables, feature_bit) {
9687 		feature = __NETIF_F_BIT(feature_bit);
9688 		if (!(features & feature) && (lower->features & feature)) {
9689 			netdev_dbg(upper, "Disabling feature %pNF on lower dev %s.\n",
9690 				   &feature, lower->name);
9691 			lower->wanted_features &= ~feature;
9692 			__netdev_update_features(lower);
9693 
9694 			if (unlikely(lower->features & feature))
9695 				netdev_WARN(upper, "failed to disable %pNF on %s!\n",
9696 					    &feature, lower->name);
9697 			else
9698 				netdev_features_change(lower);
9699 		}
9700 	}
9701 }
9702 
netdev_fix_features(struct net_device * dev,netdev_features_t features)9703 static netdev_features_t netdev_fix_features(struct net_device *dev,
9704 	netdev_features_t features)
9705 {
9706 	/* Fix illegal checksum combinations */
9707 	if ((features & NETIF_F_HW_CSUM) &&
9708 	    (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
9709 		netdev_warn(dev, "mixed HW and IP checksum settings.\n");
9710 		features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
9711 	}
9712 
9713 	/* TSO requires that SG is present as well. */
9714 	if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
9715 		netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
9716 		features &= ~NETIF_F_ALL_TSO;
9717 	}
9718 
9719 	if ((features & NETIF_F_TSO) && !(features & NETIF_F_HW_CSUM) &&
9720 					!(features & NETIF_F_IP_CSUM)) {
9721 		netdev_dbg(dev, "Dropping TSO features since no CSUM feature.\n");
9722 		features &= ~NETIF_F_TSO;
9723 		features &= ~NETIF_F_TSO_ECN;
9724 	}
9725 
9726 	if ((features & NETIF_F_TSO6) && !(features & NETIF_F_HW_CSUM) &&
9727 					 !(features & NETIF_F_IPV6_CSUM)) {
9728 		netdev_dbg(dev, "Dropping TSO6 features since no CSUM feature.\n");
9729 		features &= ~NETIF_F_TSO6;
9730 	}
9731 
9732 	/* TSO with IPv4 ID mangling requires IPv4 TSO be enabled */
9733 	if ((features & NETIF_F_TSO_MANGLEID) && !(features & NETIF_F_TSO))
9734 		features &= ~NETIF_F_TSO_MANGLEID;
9735 
9736 	/* TSO ECN requires that TSO is present as well. */
9737 	if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
9738 		features &= ~NETIF_F_TSO_ECN;
9739 
9740 	/* Software GSO depends on SG. */
9741 	if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
9742 		netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
9743 		features &= ~NETIF_F_GSO;
9744 	}
9745 
9746 	/* GSO partial features require GSO partial be set */
9747 	if ((features & dev->gso_partial_features) &&
9748 	    !(features & NETIF_F_GSO_PARTIAL)) {
9749 		netdev_dbg(dev,
9750 			   "Dropping partially supported GSO features since no GSO partial.\n");
9751 		features &= ~dev->gso_partial_features;
9752 	}
9753 
9754 	if (!(features & NETIF_F_RXCSUM)) {
9755 		/* NETIF_F_GRO_HW implies doing RXCSUM since every packet
9756 		 * successfully merged by hardware must also have the
9757 		 * checksum verified by hardware.  If the user does not
9758 		 * want to enable RXCSUM, logically, we should disable GRO_HW.
9759 		 */
9760 		if (features & NETIF_F_GRO_HW) {
9761 			netdev_dbg(dev, "Dropping NETIF_F_GRO_HW since no RXCSUM feature.\n");
9762 			features &= ~NETIF_F_GRO_HW;
9763 		}
9764 	}
9765 
9766 	/* LRO/HW-GRO features cannot be combined with RX-FCS */
9767 	if (features & NETIF_F_RXFCS) {
9768 		if (features & NETIF_F_LRO) {
9769 			netdev_dbg(dev, "Dropping LRO feature since RX-FCS is requested.\n");
9770 			features &= ~NETIF_F_LRO;
9771 		}
9772 
9773 		if (features & NETIF_F_GRO_HW) {
9774 			netdev_dbg(dev, "Dropping HW-GRO feature since RX-FCS is requested.\n");
9775 			features &= ~NETIF_F_GRO_HW;
9776 		}
9777 	}
9778 
9779 	if ((features & NETIF_F_GRO_HW) && (features & NETIF_F_LRO)) {
9780 		netdev_dbg(dev, "Dropping LRO feature since HW-GRO is requested.\n");
9781 		features &= ~NETIF_F_LRO;
9782 	}
9783 
9784 	if (features & NETIF_F_HW_TLS_TX) {
9785 		bool ip_csum = (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) ==
9786 			(NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM);
9787 		bool hw_csum = features & NETIF_F_HW_CSUM;
9788 
9789 		if (!ip_csum && !hw_csum) {
9790 			netdev_dbg(dev, "Dropping TLS TX HW offload feature since no CSUM feature.\n");
9791 			features &= ~NETIF_F_HW_TLS_TX;
9792 		}
9793 	}
9794 
9795 	if ((features & NETIF_F_HW_TLS_RX) && !(features & NETIF_F_RXCSUM)) {
9796 		netdev_dbg(dev, "Dropping TLS RX HW offload feature since no RXCSUM feature.\n");
9797 		features &= ~NETIF_F_HW_TLS_RX;
9798 	}
9799 
9800 	return features;
9801 }
9802 
__netdev_update_features(struct net_device * dev)9803 int __netdev_update_features(struct net_device *dev)
9804 {
9805 	struct net_device *upper, *lower;
9806 	netdev_features_t features;
9807 	struct list_head *iter;
9808 	int err = -1;
9809 
9810 	ASSERT_RTNL();
9811 
9812 	features = netdev_get_wanted_features(dev);
9813 
9814 	if (dev->netdev_ops->ndo_fix_features)
9815 		features = dev->netdev_ops->ndo_fix_features(dev, features);
9816 
9817 	/* driver might be less strict about feature dependencies */
9818 	features = netdev_fix_features(dev, features);
9819 
9820 	/* some features can't be enabled if they're off on an upper device */
9821 	netdev_for_each_upper_dev_rcu(dev, upper, iter)
9822 		features = netdev_sync_upper_features(dev, upper, features);
9823 
9824 	if (dev->features == features)
9825 		goto sync_lower;
9826 
9827 	netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
9828 		&dev->features, &features);
9829 
9830 	if (dev->netdev_ops->ndo_set_features)
9831 		err = dev->netdev_ops->ndo_set_features(dev, features);
9832 	else
9833 		err = 0;
9834 
9835 	if (unlikely(err < 0)) {
9836 		netdev_err(dev,
9837 			"set_features() failed (%d); wanted %pNF, left %pNF\n",
9838 			err, &features, &dev->features);
9839 		/* return non-0 since some features might have changed and
9840 		 * it's better to fire a spurious notification than miss it
9841 		 */
9842 		return -1;
9843 	}
9844 
9845 sync_lower:
9846 	/* some features must be disabled on lower devices when disabled
9847 	 * on an upper device (think: bonding master or bridge)
9848 	 */
9849 	netdev_for_each_lower_dev(dev, lower, iter)
9850 		netdev_sync_lower_features(dev, lower, features);
9851 
9852 	if (!err) {
9853 		netdev_features_t diff = features ^ dev->features;
9854 
9855 		if (diff & NETIF_F_RX_UDP_TUNNEL_PORT) {
9856 			/* udp_tunnel_{get,drop}_rx_info both need
9857 			 * NETIF_F_RX_UDP_TUNNEL_PORT enabled on the
9858 			 * device, or they won't do anything.
9859 			 * Thus we need to update dev->features
9860 			 * *before* calling udp_tunnel_get_rx_info,
9861 			 * but *after* calling udp_tunnel_drop_rx_info.
9862 			 */
9863 			if (features & NETIF_F_RX_UDP_TUNNEL_PORT) {
9864 				dev->features = features;
9865 				udp_tunnel_get_rx_info(dev);
9866 			} else {
9867 				udp_tunnel_drop_rx_info(dev);
9868 			}
9869 		}
9870 
9871 		if (diff & NETIF_F_HW_VLAN_CTAG_FILTER) {
9872 			if (features & NETIF_F_HW_VLAN_CTAG_FILTER) {
9873 				dev->features = features;
9874 				err |= vlan_get_rx_ctag_filter_info(dev);
9875 			} else {
9876 				vlan_drop_rx_ctag_filter_info(dev);
9877 			}
9878 		}
9879 
9880 		if (diff & NETIF_F_HW_VLAN_STAG_FILTER) {
9881 			if (features & NETIF_F_HW_VLAN_STAG_FILTER) {
9882 				dev->features = features;
9883 				err |= vlan_get_rx_stag_filter_info(dev);
9884 			} else {
9885 				vlan_drop_rx_stag_filter_info(dev);
9886 			}
9887 		}
9888 
9889 		dev->features = features;
9890 	}
9891 
9892 	return err < 0 ? 0 : 1;
9893 }
9894 
9895 /**
9896  *	netdev_update_features - recalculate device features
9897  *	@dev: the device to check
9898  *
9899  *	Recalculate dev->features set and send notifications if it
9900  *	has changed. Should be called after driver or hardware dependent
9901  *	conditions might have changed that influence the features.
9902  */
netdev_update_features(struct net_device * dev)9903 void netdev_update_features(struct net_device *dev)
9904 {
9905 	if (__netdev_update_features(dev))
9906 		netdev_features_change(dev);
9907 }
9908 EXPORT_SYMBOL(netdev_update_features);
9909 
9910 /**
9911  *	netdev_change_features - recalculate device features
9912  *	@dev: the device to check
9913  *
9914  *	Recalculate dev->features set and send notifications even
9915  *	if they have not changed. Should be called instead of
9916  *	netdev_update_features() if also dev->vlan_features might
9917  *	have changed to allow the changes to be propagated to stacked
9918  *	VLAN devices.
9919  */
netdev_change_features(struct net_device * dev)9920 void netdev_change_features(struct net_device *dev)
9921 {
9922 	__netdev_update_features(dev);
9923 	netdev_features_change(dev);
9924 }
9925 EXPORT_SYMBOL(netdev_change_features);
9926 
9927 /**
9928  *	netif_stacked_transfer_operstate -	transfer operstate
9929  *	@rootdev: the root or lower level device to transfer state from
9930  *	@dev: the device to transfer operstate to
9931  *
9932  *	Transfer operational state from root to device. This is normally
9933  *	called when a stacking relationship exists between the root
9934  *	device and the device(a leaf device).
9935  */
netif_stacked_transfer_operstate(const struct net_device * rootdev,struct net_device * dev)9936 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
9937 					struct net_device *dev)
9938 {
9939 	if (rootdev->operstate == IF_OPER_DORMANT)
9940 		netif_dormant_on(dev);
9941 	else
9942 		netif_dormant_off(dev);
9943 
9944 	if (rootdev->operstate == IF_OPER_TESTING)
9945 		netif_testing_on(dev);
9946 	else
9947 		netif_testing_off(dev);
9948 
9949 	if (netif_carrier_ok(rootdev))
9950 		netif_carrier_on(dev);
9951 	else
9952 		netif_carrier_off(dev);
9953 }
9954 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
9955 
netif_alloc_rx_queues(struct net_device * dev)9956 static int netif_alloc_rx_queues(struct net_device *dev)
9957 {
9958 	unsigned int i, count = dev->num_rx_queues;
9959 	struct netdev_rx_queue *rx;
9960 	size_t sz = count * sizeof(*rx);
9961 	int err = 0;
9962 
9963 	BUG_ON(count < 1);
9964 
9965 	rx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
9966 	if (!rx)
9967 		return -ENOMEM;
9968 
9969 	dev->_rx = rx;
9970 
9971 	for (i = 0; i < count; i++) {
9972 		rx[i].dev = dev;
9973 
9974 		/* XDP RX-queue setup */
9975 		err = xdp_rxq_info_reg(&rx[i].xdp_rxq, dev, i, 0);
9976 		if (err < 0)
9977 			goto err_rxq_info;
9978 	}
9979 	return 0;
9980 
9981 err_rxq_info:
9982 	/* Rollback successful reg's and free other resources */
9983 	while (i--)
9984 		xdp_rxq_info_unreg(&rx[i].xdp_rxq);
9985 	kvfree(dev->_rx);
9986 	dev->_rx = NULL;
9987 	return err;
9988 }
9989 
netif_free_rx_queues(struct net_device * dev)9990 static void netif_free_rx_queues(struct net_device *dev)
9991 {
9992 	unsigned int i, count = dev->num_rx_queues;
9993 
9994 	/* netif_alloc_rx_queues alloc failed, resources have been unreg'ed */
9995 	if (!dev->_rx)
9996 		return;
9997 
9998 	for (i = 0; i < count; i++)
9999 		xdp_rxq_info_unreg(&dev->_rx[i].xdp_rxq);
10000 
10001 	kvfree(dev->_rx);
10002 }
10003 
netdev_init_one_queue(struct net_device * dev,struct netdev_queue * queue,void * _unused)10004 static void netdev_init_one_queue(struct net_device *dev,
10005 				  struct netdev_queue *queue, void *_unused)
10006 {
10007 	/* Initialize queue lock */
10008 	spin_lock_init(&queue->_xmit_lock);
10009 	netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
10010 	queue->xmit_lock_owner = -1;
10011 	netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
10012 	queue->dev = dev;
10013 #ifdef CONFIG_BQL
10014 	dql_init(&queue->dql, HZ);
10015 #endif
10016 }
10017 
netif_free_tx_queues(struct net_device * dev)10018 static void netif_free_tx_queues(struct net_device *dev)
10019 {
10020 	kvfree(dev->_tx);
10021 }
10022 
netif_alloc_netdev_queues(struct net_device * dev)10023 static int netif_alloc_netdev_queues(struct net_device *dev)
10024 {
10025 	unsigned int count = dev->num_tx_queues;
10026 	struct netdev_queue *tx;
10027 	size_t sz = count * sizeof(*tx);
10028 
10029 	if (count < 1 || count > 0xffff)
10030 		return -EINVAL;
10031 
10032 	tx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
10033 	if (!tx)
10034 		return -ENOMEM;
10035 
10036 	dev->_tx = tx;
10037 
10038 	netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
10039 	spin_lock_init(&dev->tx_global_lock);
10040 
10041 	return 0;
10042 }
10043 
netif_tx_stop_all_queues(struct net_device * dev)10044 void netif_tx_stop_all_queues(struct net_device *dev)
10045 {
10046 	unsigned int i;
10047 
10048 	for (i = 0; i < dev->num_tx_queues; i++) {
10049 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
10050 
10051 		netif_tx_stop_queue(txq);
10052 	}
10053 }
10054 EXPORT_SYMBOL(netif_tx_stop_all_queues);
10055 
netdev_do_alloc_pcpu_stats(struct net_device * dev)10056 static int netdev_do_alloc_pcpu_stats(struct net_device *dev)
10057 {
10058 	void __percpu *v;
10059 
10060 	/* Drivers implementing ndo_get_peer_dev must support tstat
10061 	 * accounting, so that skb_do_redirect() can bump the dev's
10062 	 * RX stats upon network namespace switch.
10063 	 */
10064 	if (dev->netdev_ops->ndo_get_peer_dev &&
10065 	    dev->pcpu_stat_type != NETDEV_PCPU_STAT_TSTATS)
10066 		return -EOPNOTSUPP;
10067 
10068 	switch (dev->pcpu_stat_type) {
10069 	case NETDEV_PCPU_STAT_NONE:
10070 		return 0;
10071 	case NETDEV_PCPU_STAT_LSTATS:
10072 		v = dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
10073 		break;
10074 	case NETDEV_PCPU_STAT_TSTATS:
10075 		v = dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
10076 		break;
10077 	case NETDEV_PCPU_STAT_DSTATS:
10078 		v = dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats);
10079 		break;
10080 	default:
10081 		return -EINVAL;
10082 	}
10083 
10084 	return v ? 0 : -ENOMEM;
10085 }
10086 
netdev_do_free_pcpu_stats(struct net_device * dev)10087 static void netdev_do_free_pcpu_stats(struct net_device *dev)
10088 {
10089 	switch (dev->pcpu_stat_type) {
10090 	case NETDEV_PCPU_STAT_NONE:
10091 		return;
10092 	case NETDEV_PCPU_STAT_LSTATS:
10093 		free_percpu(dev->lstats);
10094 		break;
10095 	case NETDEV_PCPU_STAT_TSTATS:
10096 		free_percpu(dev->tstats);
10097 		break;
10098 	case NETDEV_PCPU_STAT_DSTATS:
10099 		free_percpu(dev->dstats);
10100 		break;
10101 	}
10102 }
10103 
10104 /**
10105  * register_netdevice() - register a network device
10106  * @dev: device to register
10107  *
10108  * Take a prepared network device structure and make it externally accessible.
10109  * A %NETDEV_REGISTER message is sent to the netdev notifier chain.
10110  * Callers must hold the rtnl lock - you may want register_netdev()
10111  * instead of this.
10112  */
register_netdevice(struct net_device * dev)10113 int register_netdevice(struct net_device *dev)
10114 {
10115 	int ret;
10116 	struct net *net = dev_net(dev);
10117 
10118 	BUILD_BUG_ON(sizeof(netdev_features_t) * BITS_PER_BYTE <
10119 		     NETDEV_FEATURE_COUNT);
10120 	BUG_ON(dev_boot_phase);
10121 	ASSERT_RTNL();
10122 
10123 	might_sleep();
10124 
10125 	/* When net_device's are persistent, this will be fatal. */
10126 	BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
10127 	BUG_ON(!net);
10128 
10129 	ret = ethtool_check_ops(dev->ethtool_ops);
10130 	if (ret)
10131 		return ret;
10132 
10133 	spin_lock_init(&dev->addr_list_lock);
10134 	netdev_set_addr_lockdep_class(dev);
10135 
10136 	ret = dev_get_valid_name(net, dev, dev->name);
10137 	if (ret < 0)
10138 		goto out;
10139 
10140 	ret = -ENOMEM;
10141 	dev->name_node = netdev_name_node_head_alloc(dev);
10142 	if (!dev->name_node)
10143 		goto out;
10144 
10145 	/* Init, if this function is available */
10146 	if (dev->netdev_ops->ndo_init) {
10147 		ret = dev->netdev_ops->ndo_init(dev);
10148 		if (ret) {
10149 			if (ret > 0)
10150 				ret = -EIO;
10151 			goto err_free_name;
10152 		}
10153 	}
10154 
10155 	if (((dev->hw_features | dev->features) &
10156 	     NETIF_F_HW_VLAN_CTAG_FILTER) &&
10157 	    (!dev->netdev_ops->ndo_vlan_rx_add_vid ||
10158 	     !dev->netdev_ops->ndo_vlan_rx_kill_vid)) {
10159 		netdev_WARN(dev, "Buggy VLAN acceleration in driver!\n");
10160 		ret = -EINVAL;
10161 		goto err_uninit;
10162 	}
10163 
10164 	ret = netdev_do_alloc_pcpu_stats(dev);
10165 	if (ret)
10166 		goto err_uninit;
10167 
10168 	ret = dev_index_reserve(net, dev->ifindex);
10169 	if (ret < 0)
10170 		goto err_free_pcpu;
10171 	dev->ifindex = ret;
10172 
10173 	/* Transfer changeable features to wanted_features and enable
10174 	 * software offloads (GSO and GRO).
10175 	 */
10176 	dev->hw_features |= (NETIF_F_SOFT_FEATURES | NETIF_F_SOFT_FEATURES_OFF);
10177 	dev->features |= NETIF_F_SOFT_FEATURES;
10178 
10179 	if (dev->udp_tunnel_nic_info) {
10180 		dev->features |= NETIF_F_RX_UDP_TUNNEL_PORT;
10181 		dev->hw_features |= NETIF_F_RX_UDP_TUNNEL_PORT;
10182 	}
10183 
10184 	dev->wanted_features = dev->features & dev->hw_features;
10185 
10186 	if (!(dev->flags & IFF_LOOPBACK))
10187 		dev->hw_features |= NETIF_F_NOCACHE_COPY;
10188 
10189 	/* If IPv4 TCP segmentation offload is supported we should also
10190 	 * allow the device to enable segmenting the frame with the option
10191 	 * of ignoring a static IP ID value.  This doesn't enable the
10192 	 * feature itself but allows the user to enable it later.
10193 	 */
10194 	if (dev->hw_features & NETIF_F_TSO)
10195 		dev->hw_features |= NETIF_F_TSO_MANGLEID;
10196 	if (dev->vlan_features & NETIF_F_TSO)
10197 		dev->vlan_features |= NETIF_F_TSO_MANGLEID;
10198 	if (dev->mpls_features & NETIF_F_TSO)
10199 		dev->mpls_features |= NETIF_F_TSO_MANGLEID;
10200 	if (dev->hw_enc_features & NETIF_F_TSO)
10201 		dev->hw_enc_features |= NETIF_F_TSO_MANGLEID;
10202 
10203 	/* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
10204 	 */
10205 	dev->vlan_features |= NETIF_F_HIGHDMA;
10206 
10207 	/* Make NETIF_F_SG inheritable to tunnel devices.
10208 	 */
10209 	dev->hw_enc_features |= NETIF_F_SG | NETIF_F_GSO_PARTIAL;
10210 
10211 	/* Make NETIF_F_SG inheritable to MPLS.
10212 	 */
10213 	dev->mpls_features |= NETIF_F_SG;
10214 
10215 	ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
10216 	ret = notifier_to_errno(ret);
10217 	if (ret)
10218 		goto err_ifindex_release;
10219 
10220 	ret = netdev_register_kobject(dev);
10221 	write_lock(&dev_base_lock);
10222 	dev->reg_state = ret ? NETREG_UNREGISTERED : NETREG_REGISTERED;
10223 	write_unlock(&dev_base_lock);
10224 	if (ret)
10225 		goto err_uninit_notify;
10226 
10227 	__netdev_update_features(dev);
10228 
10229 	/*
10230 	 *	Default initial state at registry is that the
10231 	 *	device is present.
10232 	 */
10233 
10234 	set_bit(__LINK_STATE_PRESENT, &dev->state);
10235 
10236 	linkwatch_init_dev(dev);
10237 
10238 	dev_init_scheduler(dev);
10239 
10240 	netdev_hold(dev, &dev->dev_registered_tracker, GFP_KERNEL);
10241 	list_netdevice(dev);
10242 
10243 	add_device_randomness(dev->dev_addr, dev->addr_len);
10244 
10245 	/* If the device has permanent device address, driver should
10246 	 * set dev_addr and also addr_assign_type should be set to
10247 	 * NET_ADDR_PERM (default value).
10248 	 */
10249 	if (dev->addr_assign_type == NET_ADDR_PERM)
10250 		memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);
10251 
10252 	/* Notify protocols, that a new device appeared. */
10253 	ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
10254 	ret = notifier_to_errno(ret);
10255 	if (ret) {
10256 		/* Expect explicit free_netdev() on failure */
10257 		dev->needs_free_netdev = false;
10258 		unregister_netdevice_queue(dev, NULL);
10259 		goto out;
10260 	}
10261 	/*
10262 	 *	Prevent userspace races by waiting until the network
10263 	 *	device is fully setup before sending notifications.
10264 	 */
10265 	if (!dev->rtnl_link_ops ||
10266 	    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
10267 		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL, 0, NULL);
10268 
10269 out:
10270 	return ret;
10271 
10272 err_uninit_notify:
10273 	call_netdevice_notifiers(NETDEV_PRE_UNINIT, dev);
10274 err_ifindex_release:
10275 	dev_index_release(net, dev->ifindex);
10276 err_free_pcpu:
10277 	netdev_do_free_pcpu_stats(dev);
10278 err_uninit:
10279 	if (dev->netdev_ops->ndo_uninit)
10280 		dev->netdev_ops->ndo_uninit(dev);
10281 	if (dev->priv_destructor)
10282 		dev->priv_destructor(dev);
10283 err_free_name:
10284 	netdev_name_node_free(dev->name_node);
10285 	goto out;
10286 }
10287 EXPORT_SYMBOL(register_netdevice);
10288 
10289 /**
10290  *	init_dummy_netdev	- init a dummy network device for NAPI
10291  *	@dev: device to init
10292  *
10293  *	This takes a network device structure and initialize the minimum
10294  *	amount of fields so it can be used to schedule NAPI polls without
10295  *	registering a full blown interface. This is to be used by drivers
10296  *	that need to tie several hardware interfaces to a single NAPI
10297  *	poll scheduler due to HW limitations.
10298  */
init_dummy_netdev(struct net_device * dev)10299 int init_dummy_netdev(struct net_device *dev)
10300 {
10301 	/* Clear everything. Note we don't initialize spinlocks
10302 	 * are they aren't supposed to be taken by any of the
10303 	 * NAPI code and this dummy netdev is supposed to be
10304 	 * only ever used for NAPI polls
10305 	 */
10306 	memset(dev, 0, sizeof(struct net_device));
10307 
10308 	/* make sure we BUG if trying to hit standard
10309 	 * register/unregister code path
10310 	 */
10311 	dev->reg_state = NETREG_DUMMY;
10312 
10313 	/* NAPI wants this */
10314 	INIT_LIST_HEAD(&dev->napi_list);
10315 
10316 	/* a dummy interface is started by default */
10317 	set_bit(__LINK_STATE_PRESENT, &dev->state);
10318 	set_bit(__LINK_STATE_START, &dev->state);
10319 
10320 	/* napi_busy_loop stats accounting wants this */
10321 	dev_net_set(dev, &init_net);
10322 
10323 	/* Note : We dont allocate pcpu_refcnt for dummy devices,
10324 	 * because users of this 'device' dont need to change
10325 	 * its refcount.
10326 	 */
10327 
10328 	return 0;
10329 }
10330 EXPORT_SYMBOL_GPL(init_dummy_netdev);
10331 
10332 
10333 /**
10334  *	register_netdev	- register a network device
10335  *	@dev: device to register
10336  *
10337  *	Take a completed network device structure and add it to the kernel
10338  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
10339  *	chain. 0 is returned on success. A negative errno code is returned
10340  *	on a failure to set up the device, or if the name is a duplicate.
10341  *
10342  *	This is a wrapper around register_netdevice that takes the rtnl semaphore
10343  *	and expands the device name if you passed a format string to
10344  *	alloc_netdev.
10345  */
register_netdev(struct net_device * dev)10346 int register_netdev(struct net_device *dev)
10347 {
10348 	int err;
10349 
10350 	if (rtnl_lock_killable())
10351 		return -EINTR;
10352 	err = register_netdevice(dev);
10353 	rtnl_unlock();
10354 	return err;
10355 }
10356 EXPORT_SYMBOL(register_netdev);
10357 
netdev_refcnt_read(const struct net_device * dev)10358 int netdev_refcnt_read(const struct net_device *dev)
10359 {
10360 #ifdef CONFIG_PCPU_DEV_REFCNT
10361 	int i, refcnt = 0;
10362 
10363 	for_each_possible_cpu(i)
10364 		refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
10365 	return refcnt;
10366 #else
10367 	return refcount_read(&dev->dev_refcnt);
10368 #endif
10369 }
10370 EXPORT_SYMBOL(netdev_refcnt_read);
10371 
10372 int netdev_unregister_timeout_secs __read_mostly = 10;
10373 
10374 #define WAIT_REFS_MIN_MSECS 1
10375 #define WAIT_REFS_MAX_MSECS 250
10376 /**
10377  * netdev_wait_allrefs_any - wait until all references are gone.
10378  * @list: list of net_devices to wait on
10379  *
10380  * This is called when unregistering network devices.
10381  *
10382  * Any protocol or device that holds a reference should register
10383  * for netdevice notification, and cleanup and put back the
10384  * reference if they receive an UNREGISTER event.
10385  * We can get stuck here if buggy protocols don't correctly
10386  * call dev_put.
10387  */
netdev_wait_allrefs_any(struct list_head * list)10388 static struct net_device *netdev_wait_allrefs_any(struct list_head *list)
10389 {
10390 	unsigned long rebroadcast_time, warning_time;
10391 	struct net_device *dev;
10392 	int wait = 0;
10393 
10394 	rebroadcast_time = warning_time = jiffies;
10395 
10396 	list_for_each_entry(dev, list, todo_list)
10397 		if (netdev_refcnt_read(dev) == 1)
10398 			return dev;
10399 
10400 	while (true) {
10401 		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
10402 			rtnl_lock();
10403 
10404 			/* Rebroadcast unregister notification */
10405 			list_for_each_entry(dev, list, todo_list)
10406 				call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10407 
10408 			__rtnl_unlock();
10409 			rcu_barrier();
10410 			rtnl_lock();
10411 
10412 			list_for_each_entry(dev, list, todo_list)
10413 				if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
10414 					     &dev->state)) {
10415 					/* We must not have linkwatch events
10416 					 * pending on unregister. If this
10417 					 * happens, we simply run the queue
10418 					 * unscheduled, resulting in a noop
10419 					 * for this device.
10420 					 */
10421 					linkwatch_run_queue();
10422 					break;
10423 				}
10424 
10425 			__rtnl_unlock();
10426 
10427 			rebroadcast_time = jiffies;
10428 		}
10429 
10430 		if (!wait) {
10431 			rcu_barrier();
10432 			wait = WAIT_REFS_MIN_MSECS;
10433 		} else {
10434 			msleep(wait);
10435 			wait = min(wait << 1, WAIT_REFS_MAX_MSECS);
10436 		}
10437 
10438 		list_for_each_entry(dev, list, todo_list)
10439 			if (netdev_refcnt_read(dev) == 1)
10440 				return dev;
10441 
10442 		if (time_after(jiffies, warning_time +
10443 			       READ_ONCE(netdev_unregister_timeout_secs) * HZ)) {
10444 			list_for_each_entry(dev, list, todo_list) {
10445 				pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
10446 					 dev->name, netdev_refcnt_read(dev));
10447 				ref_tracker_dir_print(&dev->refcnt_tracker, 10);
10448 			}
10449 
10450 			warning_time = jiffies;
10451 		}
10452 	}
10453 }
10454 
10455 /* The sequence is:
10456  *
10457  *	rtnl_lock();
10458  *	...
10459  *	register_netdevice(x1);
10460  *	register_netdevice(x2);
10461  *	...
10462  *	unregister_netdevice(y1);
10463  *	unregister_netdevice(y2);
10464  *      ...
10465  *	rtnl_unlock();
10466  *	free_netdev(y1);
10467  *	free_netdev(y2);
10468  *
10469  * We are invoked by rtnl_unlock().
10470  * This allows us to deal with problems:
10471  * 1) We can delete sysfs objects which invoke hotplug
10472  *    without deadlocking with linkwatch via keventd.
10473  * 2) Since we run with the RTNL semaphore not held, we can sleep
10474  *    safely in order to wait for the netdev refcnt to drop to zero.
10475  *
10476  * We must not return until all unregister events added during
10477  * the interval the lock was held have been completed.
10478  */
netdev_run_todo(void)10479 void netdev_run_todo(void)
10480 {
10481 	struct net_device *dev, *tmp;
10482 	struct list_head list;
10483 #ifdef CONFIG_LOCKDEP
10484 	struct list_head unlink_list;
10485 
10486 	list_replace_init(&net_unlink_list, &unlink_list);
10487 
10488 	while (!list_empty(&unlink_list)) {
10489 		struct net_device *dev = list_first_entry(&unlink_list,
10490 							  struct net_device,
10491 							  unlink_list);
10492 		list_del_init(&dev->unlink_list);
10493 		dev->nested_level = dev->lower_level - 1;
10494 	}
10495 #endif
10496 
10497 	/* Snapshot list, allow later requests */
10498 	list_replace_init(&net_todo_list, &list);
10499 
10500 	__rtnl_unlock();
10501 
10502 	/* Wait for rcu callbacks to finish before next phase */
10503 	if (!list_empty(&list))
10504 		rcu_barrier();
10505 
10506 	list_for_each_entry_safe(dev, tmp, &list, todo_list) {
10507 		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
10508 			netdev_WARN(dev, "run_todo but not unregistering\n");
10509 			list_del(&dev->todo_list);
10510 			continue;
10511 		}
10512 
10513 		write_lock(&dev_base_lock);
10514 		dev->reg_state = NETREG_UNREGISTERED;
10515 		write_unlock(&dev_base_lock);
10516 		linkwatch_forget_dev(dev);
10517 	}
10518 
10519 	while (!list_empty(&list)) {
10520 		dev = netdev_wait_allrefs_any(&list);
10521 		list_del(&dev->todo_list);
10522 
10523 		/* paranoia */
10524 		BUG_ON(netdev_refcnt_read(dev) != 1);
10525 		BUG_ON(!list_empty(&dev->ptype_all));
10526 		BUG_ON(!list_empty(&dev->ptype_specific));
10527 		WARN_ON(rcu_access_pointer(dev->ip_ptr));
10528 		WARN_ON(rcu_access_pointer(dev->ip6_ptr));
10529 
10530 		netdev_do_free_pcpu_stats(dev);
10531 		if (dev->priv_destructor)
10532 			dev->priv_destructor(dev);
10533 		if (dev->needs_free_netdev)
10534 			free_netdev(dev);
10535 
10536 		if (atomic_dec_and_test(&dev_net(dev)->dev_unreg_count))
10537 			wake_up(&netdev_unregistering_wq);
10538 
10539 		/* Free network device */
10540 		kobject_put(&dev->dev.kobj);
10541 	}
10542 }
10543 
10544 /* Convert net_device_stats to rtnl_link_stats64. rtnl_link_stats64 has
10545  * all the same fields in the same order as net_device_stats, with only
10546  * the type differing, but rtnl_link_stats64 may have additional fields
10547  * at the end for newer counters.
10548  */
netdev_stats_to_stats64(struct rtnl_link_stats64 * stats64,const struct net_device_stats * netdev_stats)10549 void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
10550 			     const struct net_device_stats *netdev_stats)
10551 {
10552 	size_t i, n = sizeof(*netdev_stats) / sizeof(atomic_long_t);
10553 	const atomic_long_t *src = (atomic_long_t *)netdev_stats;
10554 	u64 *dst = (u64 *)stats64;
10555 
10556 	BUILD_BUG_ON(n > sizeof(*stats64) / sizeof(u64));
10557 	for (i = 0; i < n; i++)
10558 		dst[i] = (unsigned long)atomic_long_read(&src[i]);
10559 	/* zero out counters that only exist in rtnl_link_stats64 */
10560 	memset((char *)stats64 + n * sizeof(u64), 0,
10561 	       sizeof(*stats64) - n * sizeof(u64));
10562 }
10563 EXPORT_SYMBOL(netdev_stats_to_stats64);
10564 
netdev_core_stats_alloc(struct net_device * dev)10565 struct net_device_core_stats __percpu *netdev_core_stats_alloc(struct net_device *dev)
10566 {
10567 	struct net_device_core_stats __percpu *p;
10568 
10569 	p = alloc_percpu_gfp(struct net_device_core_stats,
10570 			     GFP_ATOMIC | __GFP_NOWARN);
10571 
10572 	if (p && cmpxchg(&dev->core_stats, NULL, p))
10573 		free_percpu(p);
10574 
10575 	/* This READ_ONCE() pairs with the cmpxchg() above */
10576 	return READ_ONCE(dev->core_stats);
10577 }
10578 EXPORT_SYMBOL(netdev_core_stats_alloc);
10579 
10580 /**
10581  *	dev_get_stats	- get network device statistics
10582  *	@dev: device to get statistics from
10583  *	@storage: place to store stats
10584  *
10585  *	Get network statistics from device. Return @storage.
10586  *	The device driver may provide its own method by setting
10587  *	dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
10588  *	otherwise the internal statistics structure is used.
10589  */
dev_get_stats(struct net_device * dev,struct rtnl_link_stats64 * storage)10590 struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
10591 					struct rtnl_link_stats64 *storage)
10592 {
10593 	const struct net_device_ops *ops = dev->netdev_ops;
10594 	const struct net_device_core_stats __percpu *p;
10595 
10596 	if (ops->ndo_get_stats64) {
10597 		memset(storage, 0, sizeof(*storage));
10598 		ops->ndo_get_stats64(dev, storage);
10599 	} else if (ops->ndo_get_stats) {
10600 		netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
10601 	} else {
10602 		netdev_stats_to_stats64(storage, &dev->stats);
10603 	}
10604 
10605 	/* This READ_ONCE() pairs with the write in netdev_core_stats_alloc() */
10606 	p = READ_ONCE(dev->core_stats);
10607 	if (p) {
10608 		const struct net_device_core_stats *core_stats;
10609 		int i;
10610 
10611 		for_each_possible_cpu(i) {
10612 			core_stats = per_cpu_ptr(p, i);
10613 			storage->rx_dropped += READ_ONCE(core_stats->rx_dropped);
10614 			storage->tx_dropped += READ_ONCE(core_stats->tx_dropped);
10615 			storage->rx_nohandler += READ_ONCE(core_stats->rx_nohandler);
10616 			storage->rx_otherhost_dropped += READ_ONCE(core_stats->rx_otherhost_dropped);
10617 		}
10618 	}
10619 	return storage;
10620 }
10621 EXPORT_SYMBOL(dev_get_stats);
10622 
10623 /**
10624  *	dev_fetch_sw_netstats - get per-cpu network device statistics
10625  *	@s: place to store stats
10626  *	@netstats: per-cpu network stats to read from
10627  *
10628  *	Read per-cpu network statistics and populate the related fields in @s.
10629  */
dev_fetch_sw_netstats(struct rtnl_link_stats64 * s,const struct pcpu_sw_netstats __percpu * netstats)10630 void dev_fetch_sw_netstats(struct rtnl_link_stats64 *s,
10631 			   const struct pcpu_sw_netstats __percpu *netstats)
10632 {
10633 	int cpu;
10634 
10635 	for_each_possible_cpu(cpu) {
10636 		u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
10637 		const struct pcpu_sw_netstats *stats;
10638 		unsigned int start;
10639 
10640 		stats = per_cpu_ptr(netstats, cpu);
10641 		do {
10642 			start = u64_stats_fetch_begin(&stats->syncp);
10643 			rx_packets = u64_stats_read(&stats->rx_packets);
10644 			rx_bytes   = u64_stats_read(&stats->rx_bytes);
10645 			tx_packets = u64_stats_read(&stats->tx_packets);
10646 			tx_bytes   = u64_stats_read(&stats->tx_bytes);
10647 		} while (u64_stats_fetch_retry(&stats->syncp, start));
10648 
10649 		s->rx_packets += rx_packets;
10650 		s->rx_bytes   += rx_bytes;
10651 		s->tx_packets += tx_packets;
10652 		s->tx_bytes   += tx_bytes;
10653 	}
10654 }
10655 EXPORT_SYMBOL_GPL(dev_fetch_sw_netstats);
10656 
10657 /**
10658  *	dev_get_tstats64 - ndo_get_stats64 implementation
10659  *	@dev: device to get statistics from
10660  *	@s: place to store stats
10661  *
10662  *	Populate @s from dev->stats and dev->tstats. Can be used as
10663  *	ndo_get_stats64() callback.
10664  */
dev_get_tstats64(struct net_device * dev,struct rtnl_link_stats64 * s)10665 void dev_get_tstats64(struct net_device *dev, struct rtnl_link_stats64 *s)
10666 {
10667 	netdev_stats_to_stats64(s, &dev->stats);
10668 	dev_fetch_sw_netstats(s, dev->tstats);
10669 }
10670 EXPORT_SYMBOL_GPL(dev_get_tstats64);
10671 
dev_ingress_queue_create(struct net_device * dev)10672 struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
10673 {
10674 	struct netdev_queue *queue = dev_ingress_queue(dev);
10675 
10676 #ifdef CONFIG_NET_CLS_ACT
10677 	if (queue)
10678 		return queue;
10679 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
10680 	if (!queue)
10681 		return NULL;
10682 	netdev_init_one_queue(dev, queue, NULL);
10683 	RCU_INIT_POINTER(queue->qdisc, &noop_qdisc);
10684 	RCU_INIT_POINTER(queue->qdisc_sleeping, &noop_qdisc);
10685 	rcu_assign_pointer(dev->ingress_queue, queue);
10686 #endif
10687 	return queue;
10688 }
10689 
10690 static const struct ethtool_ops default_ethtool_ops;
10691 
netdev_set_default_ethtool_ops(struct net_device * dev,const struct ethtool_ops * ops)10692 void netdev_set_default_ethtool_ops(struct net_device *dev,
10693 				    const struct ethtool_ops *ops)
10694 {
10695 	if (dev->ethtool_ops == &default_ethtool_ops)
10696 		dev->ethtool_ops = ops;
10697 }
10698 EXPORT_SYMBOL_GPL(netdev_set_default_ethtool_ops);
10699 
10700 /**
10701  * netdev_sw_irq_coalesce_default_on() - enable SW IRQ coalescing by default
10702  * @dev: netdev to enable the IRQ coalescing on
10703  *
10704  * Sets a conservative default for SW IRQ coalescing. Users can use
10705  * sysfs attributes to override the default values.
10706  */
netdev_sw_irq_coalesce_default_on(struct net_device * dev)10707 void netdev_sw_irq_coalesce_default_on(struct net_device *dev)
10708 {
10709 	WARN_ON(dev->reg_state == NETREG_REGISTERED);
10710 
10711 	if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
10712 		dev->gro_flush_timeout = 20000;
10713 		dev->napi_defer_hard_irqs = 1;
10714 	}
10715 }
10716 EXPORT_SYMBOL_GPL(netdev_sw_irq_coalesce_default_on);
10717 
netdev_freemem(struct net_device * dev)10718 void netdev_freemem(struct net_device *dev)
10719 {
10720 	char *addr = (char *)dev - dev->padded;
10721 
10722 	kvfree(addr);
10723 }
10724 
10725 /**
10726  * alloc_netdev_mqs - allocate network device
10727  * @sizeof_priv: size of private data to allocate space for
10728  * @name: device name format string
10729  * @name_assign_type: origin of device name
10730  * @setup: callback to initialize device
10731  * @txqs: the number of TX subqueues to allocate
10732  * @rxqs: the number of RX subqueues to allocate
10733  *
10734  * Allocates a struct net_device with private data area for driver use
10735  * and performs basic initialization.  Also allocates subqueue structs
10736  * for each queue on the device.
10737  */
alloc_netdev_mqs(int sizeof_priv,const char * name,unsigned char name_assign_type,void (* setup)(struct net_device *),unsigned int txqs,unsigned int rxqs)10738 struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
10739 		unsigned char name_assign_type,
10740 		void (*setup)(struct net_device *),
10741 		unsigned int txqs, unsigned int rxqs)
10742 {
10743 	struct net_device *dev;
10744 	unsigned int alloc_size;
10745 	struct net_device *p;
10746 
10747 	BUG_ON(strlen(name) >= sizeof(dev->name));
10748 
10749 	if (txqs < 1) {
10750 		pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
10751 		return NULL;
10752 	}
10753 
10754 	if (rxqs < 1) {
10755 		pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
10756 		return NULL;
10757 	}
10758 
10759 	alloc_size = sizeof(struct net_device);
10760 	if (sizeof_priv) {
10761 		/* ensure 32-byte alignment of private area */
10762 		alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
10763 		alloc_size += sizeof_priv;
10764 	}
10765 	/* ensure 32-byte alignment of whole construct */
10766 	alloc_size += NETDEV_ALIGN - 1;
10767 
10768 	p = kvzalloc(alloc_size, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
10769 	if (!p)
10770 		return NULL;
10771 
10772 	dev = PTR_ALIGN(p, NETDEV_ALIGN);
10773 	dev->padded = (char *)dev - (char *)p;
10774 
10775 	ref_tracker_dir_init(&dev->refcnt_tracker, 128, name);
10776 #ifdef CONFIG_PCPU_DEV_REFCNT
10777 	dev->pcpu_refcnt = alloc_percpu(int);
10778 	if (!dev->pcpu_refcnt)
10779 		goto free_dev;
10780 	__dev_hold(dev);
10781 #else
10782 	refcount_set(&dev->dev_refcnt, 1);
10783 #endif
10784 
10785 	if (dev_addr_init(dev))
10786 		goto free_pcpu;
10787 
10788 	dev_mc_init(dev);
10789 	dev_uc_init(dev);
10790 
10791 	dev_net_set(dev, &init_net);
10792 
10793 	dev->gso_max_size = GSO_LEGACY_MAX_SIZE;
10794 	dev->xdp_zc_max_segs = 1;
10795 	dev->gso_max_segs = GSO_MAX_SEGS;
10796 	dev->gro_max_size = GRO_LEGACY_MAX_SIZE;
10797 	dev->gso_ipv4_max_size = GSO_LEGACY_MAX_SIZE;
10798 	dev->gro_ipv4_max_size = GRO_LEGACY_MAX_SIZE;
10799 	dev->tso_max_size = TSO_LEGACY_MAX_SIZE;
10800 	dev->tso_max_segs = TSO_MAX_SEGS;
10801 	dev->upper_level = 1;
10802 	dev->lower_level = 1;
10803 #ifdef CONFIG_LOCKDEP
10804 	dev->nested_level = 0;
10805 	INIT_LIST_HEAD(&dev->unlink_list);
10806 #endif
10807 
10808 	INIT_LIST_HEAD(&dev->napi_list);
10809 	INIT_LIST_HEAD(&dev->unreg_list);
10810 	INIT_LIST_HEAD(&dev->close_list);
10811 	INIT_LIST_HEAD(&dev->link_watch_list);
10812 	INIT_LIST_HEAD(&dev->adj_list.upper);
10813 	INIT_LIST_HEAD(&dev->adj_list.lower);
10814 	INIT_LIST_HEAD(&dev->ptype_all);
10815 	INIT_LIST_HEAD(&dev->ptype_specific);
10816 	INIT_LIST_HEAD(&dev->net_notifier_list);
10817 #ifdef CONFIG_NET_SCHED
10818 	hash_init(dev->qdisc_hash);
10819 #endif
10820 	dev->priv_flags = IFF_XMIT_DST_RELEASE | IFF_XMIT_DST_RELEASE_PERM;
10821 	setup(dev);
10822 
10823 	if (!dev->tx_queue_len) {
10824 		dev->priv_flags |= IFF_NO_QUEUE;
10825 		dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
10826 	}
10827 
10828 	dev->num_tx_queues = txqs;
10829 	dev->real_num_tx_queues = txqs;
10830 	if (netif_alloc_netdev_queues(dev))
10831 		goto free_all;
10832 
10833 	dev->num_rx_queues = rxqs;
10834 	dev->real_num_rx_queues = rxqs;
10835 	if (netif_alloc_rx_queues(dev))
10836 		goto free_all;
10837 
10838 	strcpy(dev->name, name);
10839 	dev->name_assign_type = name_assign_type;
10840 	dev->group = INIT_NETDEV_GROUP;
10841 	if (!dev->ethtool_ops)
10842 		dev->ethtool_ops = &default_ethtool_ops;
10843 
10844 	nf_hook_netdev_init(dev);
10845 
10846 	return dev;
10847 
10848 free_all:
10849 	free_netdev(dev);
10850 	return NULL;
10851 
10852 free_pcpu:
10853 #ifdef CONFIG_PCPU_DEV_REFCNT
10854 	free_percpu(dev->pcpu_refcnt);
10855 free_dev:
10856 #endif
10857 	netdev_freemem(dev);
10858 	return NULL;
10859 }
10860 EXPORT_SYMBOL(alloc_netdev_mqs);
10861 
10862 /**
10863  * free_netdev - free network device
10864  * @dev: device
10865  *
10866  * This function does the last stage of destroying an allocated device
10867  * interface. The reference to the device object is released. If this
10868  * is the last reference then it will be freed.Must be called in process
10869  * context.
10870  */
free_netdev(struct net_device * dev)10871 void free_netdev(struct net_device *dev)
10872 {
10873 	struct napi_struct *p, *n;
10874 
10875 	might_sleep();
10876 
10877 	/* When called immediately after register_netdevice() failed the unwind
10878 	 * handling may still be dismantling the device. Handle that case by
10879 	 * deferring the free.
10880 	 */
10881 	if (dev->reg_state == NETREG_UNREGISTERING) {
10882 		ASSERT_RTNL();
10883 		dev->needs_free_netdev = true;
10884 		return;
10885 	}
10886 
10887 	netif_free_tx_queues(dev);
10888 	netif_free_rx_queues(dev);
10889 
10890 	kfree(rcu_dereference_protected(dev->ingress_queue, 1));
10891 
10892 	/* Flush device addresses */
10893 	dev_addr_flush(dev);
10894 
10895 	list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
10896 		netif_napi_del(p);
10897 
10898 	ref_tracker_dir_exit(&dev->refcnt_tracker);
10899 #ifdef CONFIG_PCPU_DEV_REFCNT
10900 	free_percpu(dev->pcpu_refcnt);
10901 	dev->pcpu_refcnt = NULL;
10902 #endif
10903 	free_percpu(dev->core_stats);
10904 	dev->core_stats = NULL;
10905 	free_percpu(dev->xdp_bulkq);
10906 	dev->xdp_bulkq = NULL;
10907 
10908 	/*  Compatibility with error handling in drivers */
10909 	if (dev->reg_state == NETREG_UNINITIALIZED) {
10910 		netdev_freemem(dev);
10911 		return;
10912 	}
10913 
10914 	BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
10915 	dev->reg_state = NETREG_RELEASED;
10916 
10917 	/* will free via device release */
10918 	put_device(&dev->dev);
10919 }
10920 EXPORT_SYMBOL(free_netdev);
10921 
10922 /**
10923  *	synchronize_net -  Synchronize with packet receive processing
10924  *
10925  *	Wait for packets currently being received to be done.
10926  *	Does not block later packets from starting.
10927  */
synchronize_net(void)10928 void synchronize_net(void)
10929 {
10930 	might_sleep();
10931 	if (rtnl_is_locked())
10932 		synchronize_rcu_expedited();
10933 	else
10934 		synchronize_rcu();
10935 }
10936 EXPORT_SYMBOL(synchronize_net);
10937 
10938 /**
10939  *	unregister_netdevice_queue - remove device from the kernel
10940  *	@dev: device
10941  *	@head: list
10942  *
10943  *	This function shuts down a device interface and removes it
10944  *	from the kernel tables.
10945  *	If head not NULL, device is queued to be unregistered later.
10946  *
10947  *	Callers must hold the rtnl semaphore.  You may want
10948  *	unregister_netdev() instead of this.
10949  */
10950 
unregister_netdevice_queue(struct net_device * dev,struct list_head * head)10951 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
10952 {
10953 	ASSERT_RTNL();
10954 
10955 	if (head) {
10956 		list_move_tail(&dev->unreg_list, head);
10957 	} else {
10958 		LIST_HEAD(single);
10959 
10960 		list_add(&dev->unreg_list, &single);
10961 		unregister_netdevice_many(&single);
10962 	}
10963 }
10964 EXPORT_SYMBOL(unregister_netdevice_queue);
10965 
unregister_netdevice_many_notify(struct list_head * head,u32 portid,const struct nlmsghdr * nlh)10966 void unregister_netdevice_many_notify(struct list_head *head,
10967 				      u32 portid, const struct nlmsghdr *nlh)
10968 {
10969 	struct net_device *dev, *tmp;
10970 	LIST_HEAD(close_head);
10971 
10972 	BUG_ON(dev_boot_phase);
10973 	ASSERT_RTNL();
10974 
10975 	if (list_empty(head))
10976 		return;
10977 
10978 	list_for_each_entry_safe(dev, tmp, head, unreg_list) {
10979 		/* Some devices call without registering
10980 		 * for initialization unwind. Remove those
10981 		 * devices and proceed with the remaining.
10982 		 */
10983 		if (dev->reg_state == NETREG_UNINITIALIZED) {
10984 			pr_debug("unregister_netdevice: device %s/%p never was registered\n",
10985 				 dev->name, dev);
10986 
10987 			WARN_ON(1);
10988 			list_del(&dev->unreg_list);
10989 			continue;
10990 		}
10991 		dev->dismantle = true;
10992 		BUG_ON(dev->reg_state != NETREG_REGISTERED);
10993 	}
10994 
10995 	/* If device is running, close it first. */
10996 	list_for_each_entry(dev, head, unreg_list)
10997 		list_add_tail(&dev->close_list, &close_head);
10998 	dev_close_many(&close_head, true);
10999 
11000 	list_for_each_entry(dev, head, unreg_list) {
11001 		/* And unlink it from device chain. */
11002 		write_lock(&dev_base_lock);
11003 		unlist_netdevice(dev, false);
11004 		dev->reg_state = NETREG_UNREGISTERING;
11005 		write_unlock(&dev_base_lock);
11006 	}
11007 	flush_all_backlogs();
11008 
11009 	synchronize_net();
11010 
11011 	list_for_each_entry(dev, head, unreg_list) {
11012 		struct sk_buff *skb = NULL;
11013 
11014 		/* Shutdown queueing discipline. */
11015 		dev_shutdown(dev);
11016 		dev_tcx_uninstall(dev);
11017 		dev_xdp_uninstall(dev);
11018 		bpf_dev_bound_netdev_unregister(dev);
11019 
11020 		netdev_offload_xstats_disable_all(dev);
11021 
11022 		/* Notify protocols, that we are about to destroy
11023 		 * this device. They should clean all the things.
11024 		 */
11025 		call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
11026 
11027 		if (!dev->rtnl_link_ops ||
11028 		    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
11029 			skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, 0,
11030 						     GFP_KERNEL, NULL, 0,
11031 						     portid, nlh);
11032 
11033 		/*
11034 		 *	Flush the unicast and multicast chains
11035 		 */
11036 		dev_uc_flush(dev);
11037 		dev_mc_flush(dev);
11038 
11039 		netdev_name_node_alt_flush(dev);
11040 		netdev_name_node_free(dev->name_node);
11041 
11042 		call_netdevice_notifiers(NETDEV_PRE_UNINIT, dev);
11043 
11044 		if (dev->netdev_ops->ndo_uninit)
11045 			dev->netdev_ops->ndo_uninit(dev);
11046 
11047 		if (skb)
11048 			rtmsg_ifinfo_send(skb, dev, GFP_KERNEL, portid, nlh);
11049 
11050 		/* Notifier chain MUST detach us all upper devices. */
11051 		WARN_ON(netdev_has_any_upper_dev(dev));
11052 		WARN_ON(netdev_has_any_lower_dev(dev));
11053 
11054 		/* Remove entries from kobject tree */
11055 		netdev_unregister_kobject(dev);
11056 #ifdef CONFIG_XPS
11057 		/* Remove XPS queueing entries */
11058 		netif_reset_xps_queues_gt(dev, 0);
11059 #endif
11060 	}
11061 
11062 	synchronize_net();
11063 
11064 	list_for_each_entry(dev, head, unreg_list) {
11065 		netdev_put(dev, &dev->dev_registered_tracker);
11066 		net_set_todo(dev);
11067 	}
11068 
11069 	list_del(head);
11070 }
11071 
11072 /**
11073  *	unregister_netdevice_many - unregister many devices
11074  *	@head: list of devices
11075  *
11076  *  Note: As most callers use a stack allocated list_head,
11077  *  we force a list_del() to make sure stack wont be corrupted later.
11078  */
unregister_netdevice_many(struct list_head * head)11079 void unregister_netdevice_many(struct list_head *head)
11080 {
11081 	unregister_netdevice_many_notify(head, 0, NULL);
11082 }
11083 EXPORT_SYMBOL(unregister_netdevice_many);
11084 
11085 /**
11086  *	unregister_netdev - remove device from the kernel
11087  *	@dev: device
11088  *
11089  *	This function shuts down a device interface and removes it
11090  *	from the kernel tables.
11091  *
11092  *	This is just a wrapper for unregister_netdevice that takes
11093  *	the rtnl semaphore.  In general you want to use this and not
11094  *	unregister_netdevice.
11095  */
unregister_netdev(struct net_device * dev)11096 void unregister_netdev(struct net_device *dev)
11097 {
11098 	rtnl_lock();
11099 	unregister_netdevice(dev);
11100 	rtnl_unlock();
11101 }
11102 EXPORT_SYMBOL(unregister_netdev);
11103 
11104 /**
11105  *	__dev_change_net_namespace - move device to different nethost namespace
11106  *	@dev: device
11107  *	@net: network namespace
11108  *	@pat: If not NULL name pattern to try if the current device name
11109  *	      is already taken in the destination network namespace.
11110  *	@new_ifindex: If not zero, specifies device index in the target
11111  *	              namespace.
11112  *
11113  *	This function shuts down a device interface and moves it
11114  *	to a new network namespace. On success 0 is returned, on
11115  *	a failure a netagive errno code is returned.
11116  *
11117  *	Callers must hold the rtnl semaphore.
11118  */
11119 
__dev_change_net_namespace(struct net_device * dev,struct net * net,const char * pat,int new_ifindex)11120 int __dev_change_net_namespace(struct net_device *dev, struct net *net,
11121 			       const char *pat, int new_ifindex)
11122 {
11123 	struct netdev_name_node *name_node;
11124 	struct net *net_old = dev_net(dev);
11125 	char new_name[IFNAMSIZ] = {};
11126 	int err, new_nsid;
11127 
11128 	ASSERT_RTNL();
11129 
11130 	/* Don't allow namespace local devices to be moved. */
11131 	err = -EINVAL;
11132 	if (dev->features & NETIF_F_NETNS_LOCAL)
11133 		goto out;
11134 
11135 	/* Ensure the device has been registrered */
11136 	if (dev->reg_state != NETREG_REGISTERED)
11137 		goto out;
11138 
11139 	/* Get out if there is nothing todo */
11140 	err = 0;
11141 	if (net_eq(net_old, net))
11142 		goto out;
11143 
11144 	/* Pick the destination device name, and ensure
11145 	 * we can use it in the destination network namespace.
11146 	 */
11147 	err = -EEXIST;
11148 	if (netdev_name_in_use(net, dev->name)) {
11149 		/* We get here if we can't use the current device name */
11150 		if (!pat)
11151 			goto out;
11152 		err = dev_prep_valid_name(net, dev, pat, new_name);
11153 		if (err < 0)
11154 			goto out;
11155 	}
11156 	/* Check that none of the altnames conflicts. */
11157 	err = -EEXIST;
11158 	netdev_for_each_altname(dev, name_node)
11159 		if (netdev_name_in_use(net, name_node->name))
11160 			goto out;
11161 
11162 	/* Check that new_ifindex isn't used yet. */
11163 	if (new_ifindex) {
11164 		err = dev_index_reserve(net, new_ifindex);
11165 		if (err < 0)
11166 			goto out;
11167 	} else {
11168 		/* If there is an ifindex conflict assign a new one */
11169 		err = dev_index_reserve(net, dev->ifindex);
11170 		if (err == -EBUSY)
11171 			err = dev_index_reserve(net, 0);
11172 		if (err < 0)
11173 			goto out;
11174 		new_ifindex = err;
11175 	}
11176 
11177 	/*
11178 	 * And now a mini version of register_netdevice unregister_netdevice.
11179 	 */
11180 
11181 	/* If device is running close it first. */
11182 	dev_close(dev);
11183 
11184 	/* And unlink it from device chain */
11185 	unlist_netdevice(dev, true);
11186 
11187 	synchronize_net();
11188 
11189 	/* Shutdown queueing discipline. */
11190 	dev_shutdown(dev);
11191 
11192 	/* Notify protocols, that we are about to destroy
11193 	 * this device. They should clean all the things.
11194 	 *
11195 	 * Note that dev->reg_state stays at NETREG_REGISTERED.
11196 	 * This is wanted because this way 8021q and macvlan know
11197 	 * the device is just moving and can keep their slaves up.
11198 	 */
11199 	call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
11200 	rcu_barrier();
11201 
11202 	new_nsid = peernet2id_alloc(dev_net(dev), net, GFP_KERNEL);
11203 
11204 	rtmsg_ifinfo_newnet(RTM_DELLINK, dev, ~0U, GFP_KERNEL, &new_nsid,
11205 			    new_ifindex);
11206 
11207 	/*
11208 	 *	Flush the unicast and multicast chains
11209 	 */
11210 	dev_uc_flush(dev);
11211 	dev_mc_flush(dev);
11212 
11213 	/* Send a netdev-removed uevent to the old namespace */
11214 	kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);
11215 	netdev_adjacent_del_links(dev);
11216 
11217 	/* Move per-net netdevice notifiers that are following the netdevice */
11218 	move_netdevice_notifiers_dev_net(dev, net);
11219 
11220 	/* Actually switch the network namespace */
11221 	dev_net_set(dev, net);
11222 	dev->ifindex = new_ifindex;
11223 
11224 	/* Send a netdev-add uevent to the new namespace */
11225 	kobject_uevent(&dev->dev.kobj, KOBJ_ADD);
11226 	netdev_adjacent_add_links(dev);
11227 
11228 	if (new_name[0]) /* Rename the netdev to prepared name */
11229 		strscpy(dev->name, new_name, IFNAMSIZ);
11230 
11231 	/* Fixup kobjects */
11232 	err = device_rename(&dev->dev, dev->name);
11233 	WARN_ON(err);
11234 
11235 	/* Adapt owner in case owning user namespace of target network
11236 	 * namespace is different from the original one.
11237 	 */
11238 	err = netdev_change_owner(dev, net_old, net);
11239 	WARN_ON(err);
11240 
11241 	/* Add the device back in the hashes */
11242 	list_netdevice(dev);
11243 
11244 	/* Notify protocols, that a new device appeared. */
11245 	call_netdevice_notifiers(NETDEV_REGISTER, dev);
11246 
11247 	/*
11248 	 *	Prevent userspace races by waiting until the network
11249 	 *	device is fully setup before sending notifications.
11250 	 */
11251 	rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL, 0, NULL);
11252 
11253 	synchronize_net();
11254 	err = 0;
11255 out:
11256 	return err;
11257 }
11258 EXPORT_SYMBOL_GPL(__dev_change_net_namespace);
11259 
dev_cpu_dead(unsigned int oldcpu)11260 static int dev_cpu_dead(unsigned int oldcpu)
11261 {
11262 	struct sk_buff **list_skb;
11263 	struct sk_buff *skb;
11264 	unsigned int cpu;
11265 	struct softnet_data *sd, *oldsd, *remsd = NULL;
11266 
11267 	local_irq_disable();
11268 	cpu = smp_processor_id();
11269 	sd = &per_cpu(softnet_data, cpu);
11270 	oldsd = &per_cpu(softnet_data, oldcpu);
11271 
11272 	/* Find end of our completion_queue. */
11273 	list_skb = &sd->completion_queue;
11274 	while (*list_skb)
11275 		list_skb = &(*list_skb)->next;
11276 	/* Append completion queue from offline CPU. */
11277 	*list_skb = oldsd->completion_queue;
11278 	oldsd->completion_queue = NULL;
11279 
11280 	/* Append output queue from offline CPU. */
11281 	if (oldsd->output_queue) {
11282 		*sd->output_queue_tailp = oldsd->output_queue;
11283 		sd->output_queue_tailp = oldsd->output_queue_tailp;
11284 		oldsd->output_queue = NULL;
11285 		oldsd->output_queue_tailp = &oldsd->output_queue;
11286 	}
11287 	/* Append NAPI poll list from offline CPU, with one exception :
11288 	 * process_backlog() must be called by cpu owning percpu backlog.
11289 	 * We properly handle process_queue & input_pkt_queue later.
11290 	 */
11291 	while (!list_empty(&oldsd->poll_list)) {
11292 		struct napi_struct *napi = list_first_entry(&oldsd->poll_list,
11293 							    struct napi_struct,
11294 							    poll_list);
11295 
11296 		list_del_init(&napi->poll_list);
11297 		if (napi->poll == process_backlog)
11298 			napi->state = 0;
11299 		else
11300 			____napi_schedule(sd, napi);
11301 	}
11302 
11303 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
11304 	local_irq_enable();
11305 
11306 #ifdef CONFIG_RPS
11307 	remsd = oldsd->rps_ipi_list;
11308 	oldsd->rps_ipi_list = NULL;
11309 #endif
11310 	/* send out pending IPI's on offline CPU */
11311 	net_rps_send_ipi(remsd);
11312 
11313 	/* Process offline CPU's input_pkt_queue */
11314 	while ((skb = __skb_dequeue(&oldsd->process_queue))) {
11315 		netif_rx(skb);
11316 		input_queue_head_incr(oldsd);
11317 	}
11318 	while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) {
11319 		netif_rx(skb);
11320 		input_queue_head_incr(oldsd);
11321 	}
11322 
11323 	return 0;
11324 }
11325 
11326 /**
11327  *	netdev_increment_features - increment feature set by one
11328  *	@all: current feature set
11329  *	@one: new feature set
11330  *	@mask: mask feature set
11331  *
11332  *	Computes a new feature set after adding a device with feature set
11333  *	@one to the master device with current feature set @all.  Will not
11334  *	enable anything that is off in @mask. Returns the new feature set.
11335  */
netdev_increment_features(netdev_features_t all,netdev_features_t one,netdev_features_t mask)11336 netdev_features_t netdev_increment_features(netdev_features_t all,
11337 	netdev_features_t one, netdev_features_t mask)
11338 {
11339 	if (mask & NETIF_F_HW_CSUM)
11340 		mask |= NETIF_F_CSUM_MASK;
11341 	mask |= NETIF_F_VLAN_CHALLENGED;
11342 
11343 	all |= one & (NETIF_F_ONE_FOR_ALL | NETIF_F_CSUM_MASK) & mask;
11344 	all &= one | ~NETIF_F_ALL_FOR_ALL;
11345 
11346 	/* If one device supports hw checksumming, set for all. */
11347 	if (all & NETIF_F_HW_CSUM)
11348 		all &= ~(NETIF_F_CSUM_MASK & ~NETIF_F_HW_CSUM);
11349 
11350 	return all;
11351 }
11352 EXPORT_SYMBOL(netdev_increment_features);
11353 
netdev_create_hash(void)11354 static struct hlist_head * __net_init netdev_create_hash(void)
11355 {
11356 	int i;
11357 	struct hlist_head *hash;
11358 
11359 	hash = kmalloc_array(NETDEV_HASHENTRIES, sizeof(*hash), GFP_KERNEL);
11360 	if (hash != NULL)
11361 		for (i = 0; i < NETDEV_HASHENTRIES; i++)
11362 			INIT_HLIST_HEAD(&hash[i]);
11363 
11364 	return hash;
11365 }
11366 
11367 /* Initialize per network namespace state */
netdev_init(struct net * net)11368 static int __net_init netdev_init(struct net *net)
11369 {
11370 	BUILD_BUG_ON(GRO_HASH_BUCKETS >
11371 		     8 * sizeof_field(struct napi_struct, gro_bitmask));
11372 
11373 	INIT_LIST_HEAD(&net->dev_base_head);
11374 
11375 	net->dev_name_head = netdev_create_hash();
11376 	if (net->dev_name_head == NULL)
11377 		goto err_name;
11378 
11379 	net->dev_index_head = netdev_create_hash();
11380 	if (net->dev_index_head == NULL)
11381 		goto err_idx;
11382 
11383 	xa_init_flags(&net->dev_by_index, XA_FLAGS_ALLOC1);
11384 
11385 	RAW_INIT_NOTIFIER_HEAD(&net->netdev_chain);
11386 
11387 	return 0;
11388 
11389 err_idx:
11390 	kfree(net->dev_name_head);
11391 err_name:
11392 	return -ENOMEM;
11393 }
11394 
11395 /**
11396  *	netdev_drivername - network driver for the device
11397  *	@dev: network device
11398  *
11399  *	Determine network driver for device.
11400  */
netdev_drivername(const struct net_device * dev)11401 const char *netdev_drivername(const struct net_device *dev)
11402 {
11403 	const struct device_driver *driver;
11404 	const struct device *parent;
11405 	const char *empty = "";
11406 
11407 	parent = dev->dev.parent;
11408 	if (!parent)
11409 		return empty;
11410 
11411 	driver = parent->driver;
11412 	if (driver && driver->name)
11413 		return driver->name;
11414 	return empty;
11415 }
11416 
__netdev_printk(const char * level,const struct net_device * dev,struct va_format * vaf)11417 static void __netdev_printk(const char *level, const struct net_device *dev,
11418 			    struct va_format *vaf)
11419 {
11420 	if (dev && dev->dev.parent) {
11421 		dev_printk_emit(level[1] - '0',
11422 				dev->dev.parent,
11423 				"%s %s %s%s: %pV",
11424 				dev_driver_string(dev->dev.parent),
11425 				dev_name(dev->dev.parent),
11426 				netdev_name(dev), netdev_reg_state(dev),
11427 				vaf);
11428 	} else if (dev) {
11429 		printk("%s%s%s: %pV",
11430 		       level, netdev_name(dev), netdev_reg_state(dev), vaf);
11431 	} else {
11432 		printk("%s(NULL net_device): %pV", level, vaf);
11433 	}
11434 }
11435 
netdev_printk(const char * level,const struct net_device * dev,const char * format,...)11436 void netdev_printk(const char *level, const struct net_device *dev,
11437 		   const char *format, ...)
11438 {
11439 	struct va_format vaf;
11440 	va_list args;
11441 
11442 	va_start(args, format);
11443 
11444 	vaf.fmt = format;
11445 	vaf.va = &args;
11446 
11447 	__netdev_printk(level, dev, &vaf);
11448 
11449 	va_end(args);
11450 }
11451 EXPORT_SYMBOL(netdev_printk);
11452 
11453 #define define_netdev_printk_level(func, level)			\
11454 void func(const struct net_device *dev, const char *fmt, ...)	\
11455 {								\
11456 	struct va_format vaf;					\
11457 	va_list args;						\
11458 								\
11459 	va_start(args, fmt);					\
11460 								\
11461 	vaf.fmt = fmt;						\
11462 	vaf.va = &args;						\
11463 								\
11464 	__netdev_printk(level, dev, &vaf);			\
11465 								\
11466 	va_end(args);						\
11467 }								\
11468 EXPORT_SYMBOL(func);
11469 
11470 define_netdev_printk_level(netdev_emerg, KERN_EMERG);
11471 define_netdev_printk_level(netdev_alert, KERN_ALERT);
11472 define_netdev_printk_level(netdev_crit, KERN_CRIT);
11473 define_netdev_printk_level(netdev_err, KERN_ERR);
11474 define_netdev_printk_level(netdev_warn, KERN_WARNING);
11475 define_netdev_printk_level(netdev_notice, KERN_NOTICE);
11476 define_netdev_printk_level(netdev_info, KERN_INFO);
11477 
netdev_exit(struct net * net)11478 static void __net_exit netdev_exit(struct net *net)
11479 {
11480 	kfree(net->dev_name_head);
11481 	kfree(net->dev_index_head);
11482 	xa_destroy(&net->dev_by_index);
11483 	if (net != &init_net)
11484 		WARN_ON_ONCE(!list_empty(&net->dev_base_head));
11485 }
11486 
11487 static struct pernet_operations __net_initdata netdev_net_ops = {
11488 	.init = netdev_init,
11489 	.exit = netdev_exit,
11490 };
11491 
default_device_exit_net(struct net * net)11492 static void __net_exit default_device_exit_net(struct net *net)
11493 {
11494 	struct netdev_name_node *name_node, *tmp;
11495 	struct net_device *dev, *aux;
11496 	/*
11497 	 * Push all migratable network devices back to the
11498 	 * initial network namespace
11499 	 */
11500 	ASSERT_RTNL();
11501 	for_each_netdev_safe(net, dev, aux) {
11502 		int err;
11503 		char fb_name[IFNAMSIZ];
11504 
11505 		/* Ignore unmoveable devices (i.e. loopback) */
11506 		if (dev->features & NETIF_F_NETNS_LOCAL)
11507 			continue;
11508 
11509 		/* Leave virtual devices for the generic cleanup */
11510 		if (dev->rtnl_link_ops && !dev->rtnl_link_ops->netns_refund)
11511 			continue;
11512 
11513 		/* Push remaining network devices to init_net */
11514 		snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
11515 		if (netdev_name_in_use(&init_net, fb_name))
11516 			snprintf(fb_name, IFNAMSIZ, "dev%%d");
11517 
11518 		netdev_for_each_altname_safe(dev, name_node, tmp)
11519 			if (netdev_name_in_use(&init_net, name_node->name)) {
11520 				netdev_name_node_del(name_node);
11521 				synchronize_rcu();
11522 				__netdev_name_node_alt_destroy(name_node);
11523 			}
11524 
11525 		err = dev_change_net_namespace(dev, &init_net, fb_name);
11526 		if (err) {
11527 			pr_emerg("%s: failed to move %s to init_net: %d\n",
11528 				 __func__, dev->name, err);
11529 			BUG();
11530 		}
11531 	}
11532 }
11533 
default_device_exit_batch(struct list_head * net_list)11534 static void __net_exit default_device_exit_batch(struct list_head *net_list)
11535 {
11536 	/* At exit all network devices most be removed from a network
11537 	 * namespace.  Do this in the reverse order of registration.
11538 	 * Do this across as many network namespaces as possible to
11539 	 * improve batching efficiency.
11540 	 */
11541 	struct net_device *dev;
11542 	struct net *net;
11543 	LIST_HEAD(dev_kill_list);
11544 
11545 	rtnl_lock();
11546 	list_for_each_entry(net, net_list, exit_list) {
11547 		default_device_exit_net(net);
11548 		cond_resched();
11549 	}
11550 
11551 	list_for_each_entry(net, net_list, exit_list) {
11552 		for_each_netdev_reverse(net, dev) {
11553 			if (dev->rtnl_link_ops && dev->rtnl_link_ops->dellink)
11554 				dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
11555 			else
11556 				unregister_netdevice_queue(dev, &dev_kill_list);
11557 		}
11558 	}
11559 	unregister_netdevice_many(&dev_kill_list);
11560 	rtnl_unlock();
11561 }
11562 
11563 static struct pernet_operations __net_initdata default_device_ops = {
11564 	.exit_batch = default_device_exit_batch,
11565 };
11566 
11567 /*
11568  *	Initialize the DEV module. At boot time this walks the device list and
11569  *	unhooks any devices that fail to initialise (normally hardware not
11570  *	present) and leaves us with a valid list of present and active devices.
11571  *
11572  */
11573 
11574 /*
11575  *       This is called single threaded during boot, so no need
11576  *       to take the rtnl semaphore.
11577  */
net_dev_init(void)11578 static int __init net_dev_init(void)
11579 {
11580 	int i, rc = -ENOMEM;
11581 
11582 	BUG_ON(!dev_boot_phase);
11583 
11584 	if (dev_proc_init())
11585 		goto out;
11586 
11587 	if (netdev_kobject_init())
11588 		goto out;
11589 
11590 	INIT_LIST_HEAD(&ptype_all);
11591 	for (i = 0; i < PTYPE_HASH_SIZE; i++)
11592 		INIT_LIST_HEAD(&ptype_base[i]);
11593 
11594 	if (register_pernet_subsys(&netdev_net_ops))
11595 		goto out;
11596 
11597 	/*
11598 	 *	Initialise the packet receive queues.
11599 	 */
11600 
11601 	for_each_possible_cpu(i) {
11602 		struct work_struct *flush = per_cpu_ptr(&flush_works, i);
11603 		struct softnet_data *sd = &per_cpu(softnet_data, i);
11604 
11605 		INIT_WORK(flush, flush_backlog);
11606 
11607 		skb_queue_head_init(&sd->input_pkt_queue);
11608 		skb_queue_head_init(&sd->process_queue);
11609 #ifdef CONFIG_XFRM_OFFLOAD
11610 		skb_queue_head_init(&sd->xfrm_backlog);
11611 #endif
11612 		INIT_LIST_HEAD(&sd->poll_list);
11613 		sd->output_queue_tailp = &sd->output_queue;
11614 #ifdef CONFIG_RPS
11615 		INIT_CSD(&sd->csd, rps_trigger_softirq, sd);
11616 		sd->cpu = i;
11617 #endif
11618 		INIT_CSD(&sd->defer_csd, trigger_rx_softirq, sd);
11619 		spin_lock_init(&sd->defer_lock);
11620 
11621 		init_gro_hash(&sd->backlog);
11622 		sd->backlog.poll = process_backlog;
11623 		sd->backlog.weight = weight_p;
11624 	}
11625 
11626 	dev_boot_phase = 0;
11627 
11628 	/* The loopback device is special if any other network devices
11629 	 * is present in a network namespace the loopback device must
11630 	 * be present. Since we now dynamically allocate and free the
11631 	 * loopback device ensure this invariant is maintained by
11632 	 * keeping the loopback device as the first device on the
11633 	 * list of network devices.  Ensuring the loopback devices
11634 	 * is the first device that appears and the last network device
11635 	 * that disappears.
11636 	 */
11637 	if (register_pernet_device(&loopback_net_ops))
11638 		goto out;
11639 
11640 	if (register_pernet_device(&default_device_ops))
11641 		goto out;
11642 
11643 	open_softirq(NET_TX_SOFTIRQ, net_tx_action);
11644 	open_softirq(NET_RX_SOFTIRQ, net_rx_action);
11645 
11646 	rc = cpuhp_setup_state_nocalls(CPUHP_NET_DEV_DEAD, "net/dev:dead",
11647 				       NULL, dev_cpu_dead);
11648 	WARN_ON(rc < 0);
11649 	rc = 0;
11650 out:
11651 	return rc;
11652 }
11653 
11654 subsys_initcall(net_dev_init);
11655