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/bitops.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 <linux/highmem.h>
111 #include <linux/init.h>
112 #include <linux/module.h>
113 #include <linux/netpoll.h>
114 #include <linux/rcupdate.h>
115 #include <linux/delay.h>
116 #include <net/iw_handler.h>
117 #include <asm/current.h>
118 #include <linux/audit.h>
119 #include <linux/dmaengine.h>
120 #include <linux/err.h>
121 #include <linux/ctype.h>
122 #include <linux/if_arp.h>
123 #include <linux/if_vlan.h>
124 #include <linux/ip.h>
125 #include <net/ip.h>
126 #include <net/mpls.h>
127 #include <linux/ipv6.h>
128 #include <linux/in.h>
129 #include <linux/jhash.h>
130 #include <linux/random.h>
131 #include <trace/events/napi.h>
132 #include <trace/events/net.h>
133 #include <trace/events/skb.h>
134 #include <trace/events/qdisc.h>
135 #include <linux/inetdevice.h>
136 #include <linux/cpu_rmap.h>
137 #include <linux/static_key.h>
138 #include <linux/hashtable.h>
139 #include <linux/vmalloc.h>
140 #include <linux/if_macvlan.h>
141 #include <linux/errqueue.h>
142 #include <linux/hrtimer.h>
143 #include <linux/netfilter_netdev.h>
144 #include <linux/crash_dump.h>
145 #include <linux/sctp.h>
146 #include <net/udp_tunnel.h>
147 #include <linux/net_namespace.h>
148 #include <linux/indirect_call_wrapper.h>
149 #include <net/devlink.h>
150 #include <linux/pm_runtime.h>
151 #include <linux/prandom.h>
152 #include <linux/once_lite.h>
153 
154 #include "dev.h"
155 #include "net-sysfs.h"
156 
157 
158 static DEFINE_SPINLOCK(ptype_lock);
159 struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
160 struct list_head ptype_all __read_mostly;	/* Taps */
161 
162 static int netif_rx_internal(struct sk_buff *skb);
163 static int call_netdevice_notifiers_info(unsigned long val,
164 					 struct netdev_notifier_info *info);
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 	netdev_name_node_del(name_node);
349 	kfree(name_node->name);
350 	netdev_name_node_free(name_node);
351 }
352 
netdev_name_node_alt_destroy(struct net_device * dev,const char * name)353 int netdev_name_node_alt_destroy(struct net_device *dev, const char *name)
354 {
355 	struct netdev_name_node *name_node;
356 	struct net *net = dev_net(dev);
357 
358 	name_node = netdev_name_node_lookup(net, name);
359 	if (!name_node)
360 		return -ENOENT;
361 	/* lookup might have found our primary name or a name belonging
362 	 * to another device.
363 	 */
364 	if (name_node == dev->name_node || name_node->dev != dev)
365 		return -EINVAL;
366 
367 	__netdev_name_node_alt_destroy(name_node);
368 
369 	return 0;
370 }
371 
netdev_name_node_alt_flush(struct net_device * dev)372 static void netdev_name_node_alt_flush(struct net_device *dev)
373 {
374 	struct netdev_name_node *name_node, *tmp;
375 
376 	list_for_each_entry_safe(name_node, tmp, &dev->name_node->list, list)
377 		__netdev_name_node_alt_destroy(name_node);
378 }
379 
380 /* Device list insertion */
list_netdevice(struct net_device * dev)381 static void list_netdevice(struct net_device *dev)
382 {
383 	struct net *net = dev_net(dev);
384 
385 	ASSERT_RTNL();
386 
387 	write_lock(&dev_base_lock);
388 	list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
389 	netdev_name_node_add(net, dev->name_node);
390 	hlist_add_head_rcu(&dev->index_hlist,
391 			   dev_index_hash(net, dev->ifindex));
392 	write_unlock(&dev_base_lock);
393 
394 	dev_base_seq_inc(net);
395 }
396 
397 /* Device list removal
398  * caller must respect a RCU grace period before freeing/reusing dev
399  */
unlist_netdevice(struct net_device * dev,bool lock)400 static void unlist_netdevice(struct net_device *dev, bool lock)
401 {
402 	ASSERT_RTNL();
403 
404 	/* Unlink dev from the device chain */
405 	if (lock)
406 		write_lock(&dev_base_lock);
407 	list_del_rcu(&dev->dev_list);
408 	netdev_name_node_del(dev->name_node);
409 	hlist_del_rcu(&dev->index_hlist);
410 	if (lock)
411 		write_unlock(&dev_base_lock);
412 
413 	dev_base_seq_inc(dev_net(dev));
414 }
415 
416 /*
417  *	Our notifier list
418  */
419 
420 static RAW_NOTIFIER_HEAD(netdev_chain);
421 
422 /*
423  *	Device drivers call our routines to queue packets here. We empty the
424  *	queue in the local softnet handler.
425  */
426 
427 DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
428 EXPORT_PER_CPU_SYMBOL(softnet_data);
429 
430 #ifdef CONFIG_LOCKDEP
431 /*
432  * register_netdevice() inits txq->_xmit_lock and sets lockdep class
433  * according to dev->type
434  */
435 static const unsigned short netdev_lock_type[] = {
436 	 ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
437 	 ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
438 	 ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
439 	 ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
440 	 ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
441 	 ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
442 	 ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
443 	 ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
444 	 ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
445 	 ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
446 	 ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
447 	 ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
448 	 ARPHRD_FCFABRIC, ARPHRD_IEEE80211, ARPHRD_IEEE80211_PRISM,
449 	 ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET, ARPHRD_PHONET_PIPE,
450 	 ARPHRD_IEEE802154, ARPHRD_VOID, ARPHRD_NONE};
451 
452 static const char *const netdev_lock_name[] = {
453 	"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
454 	"_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
455 	"_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
456 	"_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
457 	"_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
458 	"_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
459 	"_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
460 	"_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
461 	"_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
462 	"_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
463 	"_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
464 	"_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
465 	"_xmit_FCFABRIC", "_xmit_IEEE80211", "_xmit_IEEE80211_PRISM",
466 	"_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET", "_xmit_PHONET_PIPE",
467 	"_xmit_IEEE802154", "_xmit_VOID", "_xmit_NONE"};
468 
469 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
470 static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
471 
netdev_lock_pos(unsigned short dev_type)472 static inline unsigned short netdev_lock_pos(unsigned short dev_type)
473 {
474 	int i;
475 
476 	for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
477 		if (netdev_lock_type[i] == dev_type)
478 			return i;
479 	/* the last key is used by default */
480 	return ARRAY_SIZE(netdev_lock_type) - 1;
481 }
482 
netdev_set_xmit_lockdep_class(spinlock_t * lock,unsigned short dev_type)483 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
484 						 unsigned short dev_type)
485 {
486 	int i;
487 
488 	i = netdev_lock_pos(dev_type);
489 	lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
490 				   netdev_lock_name[i]);
491 }
492 
netdev_set_addr_lockdep_class(struct net_device * dev)493 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
494 {
495 	int i;
496 
497 	i = netdev_lock_pos(dev->type);
498 	lockdep_set_class_and_name(&dev->addr_list_lock,
499 				   &netdev_addr_lock_key[i],
500 				   netdev_lock_name[i]);
501 }
502 #else
netdev_set_xmit_lockdep_class(spinlock_t * lock,unsigned short dev_type)503 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
504 						 unsigned short dev_type)
505 {
506 }
507 
netdev_set_addr_lockdep_class(struct net_device * dev)508 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
509 {
510 }
511 #endif
512 
513 /*******************************************************************************
514  *
515  *		Protocol management and registration routines
516  *
517  *******************************************************************************/
518 
519 
520 /*
521  *	Add a protocol ID to the list. Now that the input handler is
522  *	smarter we can dispense with all the messy stuff that used to be
523  *	here.
524  *
525  *	BEWARE!!! Protocol handlers, mangling input packets,
526  *	MUST BE last in hash buckets and checking protocol handlers
527  *	MUST start from promiscuous ptype_all chain in net_bh.
528  *	It is true now, do not change it.
529  *	Explanation follows: if protocol handler, mangling packet, will
530  *	be the first on list, it is not able to sense, that packet
531  *	is cloned and should be copied-on-write, so that it will
532  *	change it and subsequent readers will get broken packet.
533  *							--ANK (980803)
534  */
535 
ptype_head(const struct packet_type * pt)536 static inline struct list_head *ptype_head(const struct packet_type *pt)
537 {
538 	if (pt->type == htons(ETH_P_ALL))
539 		return pt->dev ? &pt->dev->ptype_all : &ptype_all;
540 	else
541 		return pt->dev ? &pt->dev->ptype_specific :
542 				 &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
543 }
544 
545 /**
546  *	dev_add_pack - add packet handler
547  *	@pt: packet type declaration
548  *
549  *	Add a protocol handler to the networking stack. The passed &packet_type
550  *	is linked into kernel lists and may not be freed until it has been
551  *	removed from the kernel lists.
552  *
553  *	This call does not sleep therefore it can not
554  *	guarantee all CPU's that are in middle of receiving packets
555  *	will see the new packet type (until the next received packet).
556  */
557 
dev_add_pack(struct packet_type * pt)558 void dev_add_pack(struct packet_type *pt)
559 {
560 	struct list_head *head = ptype_head(pt);
561 
562 	spin_lock(&ptype_lock);
563 	list_add_rcu(&pt->list, head);
564 	spin_unlock(&ptype_lock);
565 }
566 EXPORT_SYMBOL(dev_add_pack);
567 
568 /**
569  *	__dev_remove_pack	 - remove packet handler
570  *	@pt: packet type declaration
571  *
572  *	Remove a protocol handler that was previously added to the kernel
573  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
574  *	from the kernel lists and can be freed or reused once this function
575  *	returns.
576  *
577  *      The packet type might still be in use by receivers
578  *	and must not be freed until after all the CPU's have gone
579  *	through a quiescent state.
580  */
__dev_remove_pack(struct packet_type * pt)581 void __dev_remove_pack(struct packet_type *pt)
582 {
583 	struct list_head *head = ptype_head(pt);
584 	struct packet_type *pt1;
585 
586 	spin_lock(&ptype_lock);
587 
588 	list_for_each_entry(pt1, head, list) {
589 		if (pt == pt1) {
590 			list_del_rcu(&pt->list);
591 			goto out;
592 		}
593 	}
594 
595 	pr_warn("dev_remove_pack: %p not found\n", pt);
596 out:
597 	spin_unlock(&ptype_lock);
598 }
599 EXPORT_SYMBOL(__dev_remove_pack);
600 
601 /**
602  *	dev_remove_pack	 - remove packet handler
603  *	@pt: packet type declaration
604  *
605  *	Remove a protocol handler that was previously added to the kernel
606  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
607  *	from the kernel lists and can be freed or reused once this function
608  *	returns.
609  *
610  *	This call sleeps to guarantee that no CPU is looking at the packet
611  *	type after return.
612  */
dev_remove_pack(struct packet_type * pt)613 void dev_remove_pack(struct packet_type *pt)
614 {
615 	__dev_remove_pack(pt);
616 
617 	synchronize_net();
618 }
619 EXPORT_SYMBOL(dev_remove_pack);
620 
621 
622 /*******************************************************************************
623  *
624  *			    Device Interface Subroutines
625  *
626  *******************************************************************************/
627 
628 /**
629  *	dev_get_iflink	- get 'iflink' value of a interface
630  *	@dev: targeted interface
631  *
632  *	Indicates the ifindex the interface is linked to.
633  *	Physical interfaces have the same 'ifindex' and 'iflink' values.
634  */
635 
dev_get_iflink(const struct net_device * dev)636 int dev_get_iflink(const struct net_device *dev)
637 {
638 	if (dev->netdev_ops && dev->netdev_ops->ndo_get_iflink)
639 		return dev->netdev_ops->ndo_get_iflink(dev);
640 
641 	return dev->ifindex;
642 }
643 EXPORT_SYMBOL(dev_get_iflink);
644 
645 /**
646  *	dev_fill_metadata_dst - Retrieve tunnel egress information.
647  *	@dev: targeted interface
648  *	@skb: The packet.
649  *
650  *	For better visibility of tunnel traffic OVS needs to retrieve
651  *	egress tunnel information for a packet. Following API allows
652  *	user to get this info.
653  */
dev_fill_metadata_dst(struct net_device * dev,struct sk_buff * skb)654 int dev_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
655 {
656 	struct ip_tunnel_info *info;
657 
658 	if (!dev->netdev_ops  || !dev->netdev_ops->ndo_fill_metadata_dst)
659 		return -EINVAL;
660 
661 	info = skb_tunnel_info_unclone(skb);
662 	if (!info)
663 		return -ENOMEM;
664 	if (unlikely(!(info->mode & IP_TUNNEL_INFO_TX)))
665 		return -EINVAL;
666 
667 	return dev->netdev_ops->ndo_fill_metadata_dst(dev, skb);
668 }
669 EXPORT_SYMBOL_GPL(dev_fill_metadata_dst);
670 
dev_fwd_path(struct net_device_path_stack * stack)671 static struct net_device_path *dev_fwd_path(struct net_device_path_stack *stack)
672 {
673 	int k = stack->num_paths++;
674 
675 	if (WARN_ON_ONCE(k >= NET_DEVICE_PATH_STACK_MAX))
676 		return NULL;
677 
678 	return &stack->path[k];
679 }
680 
dev_fill_forward_path(const struct net_device * dev,const u8 * daddr,struct net_device_path_stack * stack)681 int dev_fill_forward_path(const struct net_device *dev, const u8 *daddr,
682 			  struct net_device_path_stack *stack)
683 {
684 	const struct net_device *last_dev;
685 	struct net_device_path_ctx ctx = {
686 		.dev	= dev,
687 	};
688 	struct net_device_path *path;
689 	int ret = 0;
690 
691 	memcpy(ctx.daddr, daddr, sizeof(ctx.daddr));
692 	stack->num_paths = 0;
693 	while (ctx.dev && ctx.dev->netdev_ops->ndo_fill_forward_path) {
694 		last_dev = ctx.dev;
695 		path = dev_fwd_path(stack);
696 		if (!path)
697 			return -1;
698 
699 		memset(path, 0, sizeof(struct net_device_path));
700 		ret = ctx.dev->netdev_ops->ndo_fill_forward_path(&ctx, path);
701 		if (ret < 0)
702 			return -1;
703 
704 		if (WARN_ON_ONCE(last_dev == ctx.dev))
705 			return -1;
706 	}
707 
708 	if (!ctx.dev)
709 		return ret;
710 
711 	path = dev_fwd_path(stack);
712 	if (!path)
713 		return -1;
714 	path->type = DEV_PATH_ETHERNET;
715 	path->dev = ctx.dev;
716 
717 	return ret;
718 }
719 EXPORT_SYMBOL_GPL(dev_fill_forward_path);
720 
721 /**
722  *	__dev_get_by_name	- find a device by its name
723  *	@net: the applicable net namespace
724  *	@name: name to find
725  *
726  *	Find an interface by name. Must be called under RTNL semaphore
727  *	or @dev_base_lock. If the name is found a pointer to the device
728  *	is returned. If the name is not found then %NULL is returned. The
729  *	reference counters are not incremented so the caller must be
730  *	careful with locks.
731  */
732 
__dev_get_by_name(struct net * net,const char * name)733 struct net_device *__dev_get_by_name(struct net *net, const char *name)
734 {
735 	struct netdev_name_node *node_name;
736 
737 	node_name = netdev_name_node_lookup(net, name);
738 	return node_name ? node_name->dev : NULL;
739 }
740 EXPORT_SYMBOL(__dev_get_by_name);
741 
742 /**
743  * dev_get_by_name_rcu	- find a device by its name
744  * @net: the applicable net namespace
745  * @name: name to find
746  *
747  * Find an interface by name.
748  * If the name is found a pointer to the device is returned.
749  * If the name is not found then %NULL is returned.
750  * The reference counters are not incremented so the caller must be
751  * careful with locks. The caller must hold RCU lock.
752  */
753 
dev_get_by_name_rcu(struct net * net,const char * name)754 struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
755 {
756 	struct netdev_name_node *node_name;
757 
758 	node_name = netdev_name_node_lookup_rcu(net, name);
759 	return node_name ? node_name->dev : NULL;
760 }
761 EXPORT_SYMBOL(dev_get_by_name_rcu);
762 
763 /**
764  *	dev_get_by_name		- find a device by its name
765  *	@net: the applicable net namespace
766  *	@name: name to find
767  *
768  *	Find an interface by name. This can be called from any
769  *	context and does its own locking. The returned handle has
770  *	the usage count incremented and the caller must use dev_put() to
771  *	release it when it is no longer needed. %NULL is returned if no
772  *	matching device is found.
773  */
774 
dev_get_by_name(struct net * net,const char * name)775 struct net_device *dev_get_by_name(struct net *net, const char *name)
776 {
777 	struct net_device *dev;
778 
779 	rcu_read_lock();
780 	dev = dev_get_by_name_rcu(net, name);
781 	dev_hold(dev);
782 	rcu_read_unlock();
783 	return dev;
784 }
785 EXPORT_SYMBOL(dev_get_by_name);
786 
787 /**
788  *	__dev_get_by_index - find a device by its ifindex
789  *	@net: the applicable net namespace
790  *	@ifindex: index of device
791  *
792  *	Search for an interface by index. Returns %NULL if the device
793  *	is not found or a pointer to the device. The device has not
794  *	had its reference counter increased so the caller must be careful
795  *	about locking. The caller must hold either the RTNL semaphore
796  *	or @dev_base_lock.
797  */
798 
__dev_get_by_index(struct net * net,int ifindex)799 struct net_device *__dev_get_by_index(struct net *net, int ifindex)
800 {
801 	struct net_device *dev;
802 	struct hlist_head *head = dev_index_hash(net, ifindex);
803 
804 	hlist_for_each_entry(dev, head, index_hlist)
805 		if (dev->ifindex == ifindex)
806 			return dev;
807 
808 	return NULL;
809 }
810 EXPORT_SYMBOL(__dev_get_by_index);
811 
812 /**
813  *	dev_get_by_index_rcu - find a device by its ifindex
814  *	@net: the applicable net namespace
815  *	@ifindex: index of device
816  *
817  *	Search for an interface by index. Returns %NULL if the device
818  *	is not found or a pointer to the device. The device has not
819  *	had its reference counter increased so the caller must be careful
820  *	about locking. The caller must hold RCU lock.
821  */
822 
dev_get_by_index_rcu(struct net * net,int ifindex)823 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
824 {
825 	struct net_device *dev;
826 	struct hlist_head *head = dev_index_hash(net, ifindex);
827 
828 	hlist_for_each_entry_rcu(dev, head, index_hlist)
829 		if (dev->ifindex == ifindex)
830 			return dev;
831 
832 	return NULL;
833 }
834 EXPORT_SYMBOL(dev_get_by_index_rcu);
835 
836 
837 /**
838  *	dev_get_by_index - find a device by its ifindex
839  *	@net: the applicable net namespace
840  *	@ifindex: index of device
841  *
842  *	Search for an interface by index. Returns NULL if the device
843  *	is not found or a pointer to the device. The device returned has
844  *	had a reference added and the pointer is safe until the user calls
845  *	dev_put to indicate they have finished with it.
846  */
847 
dev_get_by_index(struct net * net,int ifindex)848 struct net_device *dev_get_by_index(struct net *net, int ifindex)
849 {
850 	struct net_device *dev;
851 
852 	rcu_read_lock();
853 	dev = dev_get_by_index_rcu(net, ifindex);
854 	dev_hold(dev);
855 	rcu_read_unlock();
856 	return dev;
857 }
858 EXPORT_SYMBOL(dev_get_by_index);
859 
860 /**
861  *	dev_get_by_napi_id - find a device by napi_id
862  *	@napi_id: ID of the NAPI struct
863  *
864  *	Search for an interface by NAPI ID. Returns %NULL if the device
865  *	is not found or a pointer to the device. The device has not had
866  *	its reference counter increased so the caller must be careful
867  *	about locking. The caller must hold RCU lock.
868  */
869 
dev_get_by_napi_id(unsigned int napi_id)870 struct net_device *dev_get_by_napi_id(unsigned int napi_id)
871 {
872 	struct napi_struct *napi;
873 
874 	WARN_ON_ONCE(!rcu_read_lock_held());
875 
876 	if (napi_id < MIN_NAPI_ID)
877 		return NULL;
878 
879 	napi = napi_by_id(napi_id);
880 
881 	return napi ? napi->dev : NULL;
882 }
883 EXPORT_SYMBOL(dev_get_by_napi_id);
884 
885 /**
886  *	netdev_get_name - get a netdevice name, knowing its ifindex.
887  *	@net: network namespace
888  *	@name: a pointer to the buffer where the name will be stored.
889  *	@ifindex: the ifindex of the interface to get the name from.
890  */
netdev_get_name(struct net * net,char * name,int ifindex)891 int netdev_get_name(struct net *net, char *name, int ifindex)
892 {
893 	struct net_device *dev;
894 	int ret;
895 
896 	down_read(&devnet_rename_sem);
897 	rcu_read_lock();
898 
899 	dev = dev_get_by_index_rcu(net, ifindex);
900 	if (!dev) {
901 		ret = -ENODEV;
902 		goto out;
903 	}
904 
905 	strcpy(name, dev->name);
906 
907 	ret = 0;
908 out:
909 	rcu_read_unlock();
910 	up_read(&devnet_rename_sem);
911 	return ret;
912 }
913 
914 /**
915  *	dev_getbyhwaddr_rcu - find a device by its hardware address
916  *	@net: the applicable net namespace
917  *	@type: media type of device
918  *	@ha: hardware address
919  *
920  *	Search for an interface by MAC address. Returns NULL if the device
921  *	is not found or a pointer to the device.
922  *	The caller must hold RCU or RTNL.
923  *	The returned device has not had its ref count increased
924  *	and the caller must therefore be careful about locking
925  *
926  */
927 
dev_getbyhwaddr_rcu(struct net * net,unsigned short type,const char * ha)928 struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
929 				       const char *ha)
930 {
931 	struct net_device *dev;
932 
933 	for_each_netdev_rcu(net, dev)
934 		if (dev->type == type &&
935 		    !memcmp(dev->dev_addr, ha, dev->addr_len))
936 			return dev;
937 
938 	return NULL;
939 }
940 EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
941 
dev_getfirstbyhwtype(struct net * net,unsigned short type)942 struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
943 {
944 	struct net_device *dev, *ret = NULL;
945 
946 	rcu_read_lock();
947 	for_each_netdev_rcu(net, dev)
948 		if (dev->type == type) {
949 			dev_hold(dev);
950 			ret = dev;
951 			break;
952 		}
953 	rcu_read_unlock();
954 	return ret;
955 }
956 EXPORT_SYMBOL(dev_getfirstbyhwtype);
957 
958 /**
959  *	__dev_get_by_flags - find any device with given flags
960  *	@net: the applicable net namespace
961  *	@if_flags: IFF_* values
962  *	@mask: bitmask of bits in if_flags to check
963  *
964  *	Search for any interface with the given flags. Returns NULL if a device
965  *	is not found or a pointer to the device. Must be called inside
966  *	rtnl_lock(), and result refcount is unchanged.
967  */
968 
__dev_get_by_flags(struct net * net,unsigned short if_flags,unsigned short mask)969 struct net_device *__dev_get_by_flags(struct net *net, unsigned short if_flags,
970 				      unsigned short mask)
971 {
972 	struct net_device *dev, *ret;
973 
974 	ASSERT_RTNL();
975 
976 	ret = NULL;
977 	for_each_netdev(net, dev) {
978 		if (((dev->flags ^ if_flags) & mask) == 0) {
979 			ret = dev;
980 			break;
981 		}
982 	}
983 	return ret;
984 }
985 EXPORT_SYMBOL(__dev_get_by_flags);
986 
987 /**
988  *	dev_valid_name - check if name is okay for network device
989  *	@name: name string
990  *
991  *	Network device names need to be valid file names to
992  *	allow sysfs to work.  We also disallow any kind of
993  *	whitespace.
994  */
dev_valid_name(const char * name)995 bool dev_valid_name(const char *name)
996 {
997 	if (*name == '\0')
998 		return false;
999 	if (strnlen(name, IFNAMSIZ) == IFNAMSIZ)
1000 		return false;
1001 	if (!strcmp(name, ".") || !strcmp(name, ".."))
1002 		return false;
1003 
1004 	while (*name) {
1005 		if (*name == '/' || *name == ':' || isspace(*name))
1006 			return false;
1007 		name++;
1008 	}
1009 	return true;
1010 }
1011 EXPORT_SYMBOL(dev_valid_name);
1012 
1013 /**
1014  *	__dev_alloc_name - allocate a name for a device
1015  *	@net: network namespace to allocate the device name in
1016  *	@name: name format string
1017  *	@buf:  scratch buffer and result name string
1018  *
1019  *	Passed a format string - eg "lt%d" it will try and find a suitable
1020  *	id. It scans list of devices to build up a free map, then chooses
1021  *	the first empty slot. The caller must hold the dev_base or rtnl lock
1022  *	while allocating the name and adding the device in order to avoid
1023  *	duplicates.
1024  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1025  *	Returns the number of the unit assigned or a negative errno code.
1026  */
1027 
__dev_alloc_name(struct net * net,const char * name,char * buf)1028 static int __dev_alloc_name(struct net *net, const char *name, char *buf)
1029 {
1030 	int i = 0;
1031 	const char *p;
1032 	const int max_netdevices = 8*PAGE_SIZE;
1033 	unsigned long *inuse;
1034 	struct net_device *d;
1035 
1036 	if (!dev_valid_name(name))
1037 		return -EINVAL;
1038 
1039 	p = strchr(name, '%');
1040 	if (p) {
1041 		/*
1042 		 * Verify the string as this thing may have come from
1043 		 * the user.  There must be either one "%d" and no other "%"
1044 		 * characters.
1045 		 */
1046 		if (p[1] != 'd' || strchr(p + 2, '%'))
1047 			return -EINVAL;
1048 
1049 		/* Use one page as a bit array of possible slots */
1050 		inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
1051 		if (!inuse)
1052 			return -ENOMEM;
1053 
1054 		for_each_netdev(net, d) {
1055 			struct netdev_name_node *name_node;
1056 			list_for_each_entry(name_node, &d->name_node->list, list) {
1057 				if (!sscanf(name_node->name, name, &i))
1058 					continue;
1059 				if (i < 0 || i >= max_netdevices)
1060 					continue;
1061 
1062 				/*  avoid cases where sscanf is not exact inverse of printf */
1063 				snprintf(buf, IFNAMSIZ, name, i);
1064 				if (!strncmp(buf, name_node->name, IFNAMSIZ))
1065 					__set_bit(i, inuse);
1066 			}
1067 			if (!sscanf(d->name, name, &i))
1068 				continue;
1069 			if (i < 0 || i >= max_netdevices)
1070 				continue;
1071 
1072 			/*  avoid cases where sscanf is not exact inverse of printf */
1073 			snprintf(buf, IFNAMSIZ, name, i);
1074 			if (!strncmp(buf, d->name, IFNAMSIZ))
1075 				__set_bit(i, inuse);
1076 		}
1077 
1078 		i = find_first_zero_bit(inuse, max_netdevices);
1079 		free_page((unsigned long) inuse);
1080 	}
1081 
1082 	snprintf(buf, IFNAMSIZ, name, i);
1083 	if (!netdev_name_in_use(net, buf))
1084 		return i;
1085 
1086 	/* It is possible to run out of possible slots
1087 	 * when the name is long and there isn't enough space left
1088 	 * for the digits, or if all bits are used.
1089 	 */
1090 	return -ENFILE;
1091 }
1092 
dev_alloc_name_ns(struct net * net,struct net_device * dev,const char * name)1093 static int dev_alloc_name_ns(struct net *net,
1094 			     struct net_device *dev,
1095 			     const char *name)
1096 {
1097 	char buf[IFNAMSIZ];
1098 	int ret;
1099 
1100 	BUG_ON(!net);
1101 	ret = __dev_alloc_name(net, name, buf);
1102 	if (ret >= 0)
1103 		strscpy(dev->name, buf, IFNAMSIZ);
1104 	return ret;
1105 }
1106 
1107 /**
1108  *	dev_alloc_name - allocate a name for a device
1109  *	@dev: device
1110  *	@name: name format string
1111  *
1112  *	Passed a format string - eg "lt%d" it will try and find a suitable
1113  *	id. It scans list of devices to build up a free map, then chooses
1114  *	the first empty slot. The caller must hold the dev_base or rtnl lock
1115  *	while allocating the name and adding the device in order to avoid
1116  *	duplicates.
1117  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1118  *	Returns the number of the unit assigned or a negative errno code.
1119  */
1120 
dev_alloc_name(struct net_device * dev,const char * name)1121 int dev_alloc_name(struct net_device *dev, const char *name)
1122 {
1123 	return dev_alloc_name_ns(dev_net(dev), dev, name);
1124 }
1125 EXPORT_SYMBOL(dev_alloc_name);
1126 
dev_get_valid_name(struct net * net,struct net_device * dev,const char * name)1127 static int dev_get_valid_name(struct net *net, struct net_device *dev,
1128 			      const char *name)
1129 {
1130 	BUG_ON(!net);
1131 
1132 	if (!dev_valid_name(name))
1133 		return -EINVAL;
1134 
1135 	if (strchr(name, '%'))
1136 		return dev_alloc_name_ns(net, dev, name);
1137 	else if (netdev_name_in_use(net, name))
1138 		return -EEXIST;
1139 	else if (dev->name != name)
1140 		strscpy(dev->name, name, IFNAMSIZ);
1141 
1142 	return 0;
1143 }
1144 
1145 /**
1146  *	dev_change_name - change name of a device
1147  *	@dev: device
1148  *	@newname: name (or format string) must be at least IFNAMSIZ
1149  *
1150  *	Change name of a device, can pass format strings "eth%d".
1151  *	for wildcarding.
1152  */
dev_change_name(struct net_device * dev,const char * newname)1153 int dev_change_name(struct net_device *dev, const char *newname)
1154 {
1155 	unsigned char old_assign_type;
1156 	char oldname[IFNAMSIZ];
1157 	int err = 0;
1158 	int ret;
1159 	struct net *net;
1160 
1161 	ASSERT_RTNL();
1162 	BUG_ON(!dev_net(dev));
1163 
1164 	net = dev_net(dev);
1165 
1166 	/* Some auto-enslaved devices e.g. failover slaves are
1167 	 * special, as userspace might rename the device after
1168 	 * the interface had been brought up and running since
1169 	 * the point kernel initiated auto-enslavement. Allow
1170 	 * live name change even when these slave devices are
1171 	 * up and running.
1172 	 *
1173 	 * Typically, users of these auto-enslaving devices
1174 	 * don't actually care about slave name change, as
1175 	 * they are supposed to operate on master interface
1176 	 * directly.
1177 	 */
1178 	if (dev->flags & IFF_UP &&
1179 	    likely(!(dev->priv_flags & IFF_LIVE_RENAME_OK)))
1180 		return -EBUSY;
1181 
1182 	down_write(&devnet_rename_sem);
1183 
1184 	if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
1185 		up_write(&devnet_rename_sem);
1186 		return 0;
1187 	}
1188 
1189 	memcpy(oldname, dev->name, IFNAMSIZ);
1190 
1191 	err = dev_get_valid_name(net, dev, newname);
1192 	if (err < 0) {
1193 		up_write(&devnet_rename_sem);
1194 		return err;
1195 	}
1196 
1197 	if (oldname[0] && !strchr(oldname, '%'))
1198 		netdev_info(dev, "renamed from %s\n", oldname);
1199 
1200 	old_assign_type = dev->name_assign_type;
1201 	dev->name_assign_type = NET_NAME_RENAMED;
1202 
1203 rollback:
1204 	ret = device_rename(&dev->dev, dev->name);
1205 	if (ret) {
1206 		memcpy(dev->name, oldname, IFNAMSIZ);
1207 		dev->name_assign_type = old_assign_type;
1208 		up_write(&devnet_rename_sem);
1209 		return ret;
1210 	}
1211 
1212 	up_write(&devnet_rename_sem);
1213 
1214 	netdev_adjacent_rename_links(dev, oldname);
1215 
1216 	write_lock(&dev_base_lock);
1217 	netdev_name_node_del(dev->name_node);
1218 	write_unlock(&dev_base_lock);
1219 
1220 	synchronize_rcu();
1221 
1222 	write_lock(&dev_base_lock);
1223 	netdev_name_node_add(net, dev->name_node);
1224 	write_unlock(&dev_base_lock);
1225 
1226 	ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1227 	ret = notifier_to_errno(ret);
1228 
1229 	if (ret) {
1230 		/* err >= 0 after dev_alloc_name() or stores the first errno */
1231 		if (err >= 0) {
1232 			err = ret;
1233 			down_write(&devnet_rename_sem);
1234 			memcpy(dev->name, oldname, IFNAMSIZ);
1235 			memcpy(oldname, newname, IFNAMSIZ);
1236 			dev->name_assign_type = old_assign_type;
1237 			old_assign_type = NET_NAME_RENAMED;
1238 			goto rollback;
1239 		} else {
1240 			netdev_err(dev, "name change rollback failed: %d\n",
1241 				   ret);
1242 		}
1243 	}
1244 
1245 	return err;
1246 }
1247 
1248 /**
1249  *	dev_set_alias - change ifalias of a device
1250  *	@dev: device
1251  *	@alias: name up to IFALIASZ
1252  *	@len: limit of bytes to copy from info
1253  *
1254  *	Set ifalias for a device,
1255  */
dev_set_alias(struct net_device * dev,const char * alias,size_t len)1256 int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
1257 {
1258 	struct dev_ifalias *new_alias = NULL;
1259 
1260 	if (len >= IFALIASZ)
1261 		return -EINVAL;
1262 
1263 	if (len) {
1264 		new_alias = kmalloc(sizeof(*new_alias) + len + 1, GFP_KERNEL);
1265 		if (!new_alias)
1266 			return -ENOMEM;
1267 
1268 		memcpy(new_alias->ifalias, alias, len);
1269 		new_alias->ifalias[len] = 0;
1270 	}
1271 
1272 	mutex_lock(&ifalias_mutex);
1273 	new_alias = rcu_replace_pointer(dev->ifalias, new_alias,
1274 					mutex_is_locked(&ifalias_mutex));
1275 	mutex_unlock(&ifalias_mutex);
1276 
1277 	if (new_alias)
1278 		kfree_rcu(new_alias, rcuhead);
1279 
1280 	return len;
1281 }
1282 EXPORT_SYMBOL(dev_set_alias);
1283 
1284 /**
1285  *	dev_get_alias - get ifalias of a device
1286  *	@dev: device
1287  *	@name: buffer to store name of ifalias
1288  *	@len: size of buffer
1289  *
1290  *	get ifalias for a device.  Caller must make sure dev cannot go
1291  *	away,  e.g. rcu read lock or own a reference count to device.
1292  */
dev_get_alias(const struct net_device * dev,char * name,size_t len)1293 int dev_get_alias(const struct net_device *dev, char *name, size_t len)
1294 {
1295 	const struct dev_ifalias *alias;
1296 	int ret = 0;
1297 
1298 	rcu_read_lock();
1299 	alias = rcu_dereference(dev->ifalias);
1300 	if (alias)
1301 		ret = snprintf(name, len, "%s", alias->ifalias);
1302 	rcu_read_unlock();
1303 
1304 	return ret;
1305 }
1306 
1307 /**
1308  *	netdev_features_change - device changes features
1309  *	@dev: device to cause notification
1310  *
1311  *	Called to indicate a device has changed features.
1312  */
netdev_features_change(struct net_device * dev)1313 void netdev_features_change(struct net_device *dev)
1314 {
1315 	call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1316 }
1317 EXPORT_SYMBOL(netdev_features_change);
1318 
1319 /**
1320  *	netdev_state_change - device changes state
1321  *	@dev: device to cause notification
1322  *
1323  *	Called to indicate a device has changed state. This function calls
1324  *	the notifier chains for netdev_chain and sends a NEWLINK message
1325  *	to the routing socket.
1326  */
netdev_state_change(struct net_device * dev)1327 void netdev_state_change(struct net_device *dev)
1328 {
1329 	if (dev->flags & IFF_UP) {
1330 		struct netdev_notifier_change_info change_info = {
1331 			.info.dev = dev,
1332 		};
1333 
1334 		call_netdevice_notifiers_info(NETDEV_CHANGE,
1335 					      &change_info.info);
1336 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL);
1337 	}
1338 }
1339 EXPORT_SYMBOL(netdev_state_change);
1340 
1341 /**
1342  * __netdev_notify_peers - notify network peers about existence of @dev,
1343  * to be called when rtnl lock is already held.
1344  * @dev: network device
1345  *
1346  * Generate traffic such that interested network peers are aware of
1347  * @dev, such as by generating a gratuitous ARP. This may be used when
1348  * a device wants to inform the rest of the network about some sort of
1349  * reconfiguration such as a failover event or virtual machine
1350  * migration.
1351  */
__netdev_notify_peers(struct net_device * dev)1352 void __netdev_notify_peers(struct net_device *dev)
1353 {
1354 	ASSERT_RTNL();
1355 	call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
1356 	call_netdevice_notifiers(NETDEV_RESEND_IGMP, dev);
1357 }
1358 EXPORT_SYMBOL(__netdev_notify_peers);
1359 
1360 /**
1361  * netdev_notify_peers - notify network peers about existence of @dev
1362  * @dev: network device
1363  *
1364  * Generate traffic such that interested network peers are aware of
1365  * @dev, such as by generating a gratuitous ARP. This may be used when
1366  * a device wants to inform the rest of the network about some sort of
1367  * reconfiguration such as a failover event or virtual machine
1368  * migration.
1369  */
netdev_notify_peers(struct net_device * dev)1370 void netdev_notify_peers(struct net_device *dev)
1371 {
1372 	rtnl_lock();
1373 	__netdev_notify_peers(dev);
1374 	rtnl_unlock();
1375 }
1376 EXPORT_SYMBOL(netdev_notify_peers);
1377 
1378 static int napi_threaded_poll(void *data);
1379 
napi_kthread_create(struct napi_struct * n)1380 static int napi_kthread_create(struct napi_struct *n)
1381 {
1382 	int err = 0;
1383 
1384 	/* Create and wake up the kthread once to put it in
1385 	 * TASK_INTERRUPTIBLE mode to avoid the blocked task
1386 	 * warning and work with loadavg.
1387 	 */
1388 	n->thread = kthread_run(napi_threaded_poll, n, "napi/%s-%d",
1389 				n->dev->name, n->napi_id);
1390 	if (IS_ERR(n->thread)) {
1391 		err = PTR_ERR(n->thread);
1392 		pr_err("kthread_run failed with err %d\n", err);
1393 		n->thread = NULL;
1394 	}
1395 
1396 	return err;
1397 }
1398 
__dev_open(struct net_device * dev,struct netlink_ext_ack * extack)1399 static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1400 {
1401 	const struct net_device_ops *ops = dev->netdev_ops;
1402 	int ret;
1403 
1404 	ASSERT_RTNL();
1405 	dev_addr_check(dev);
1406 
1407 	if (!netif_device_present(dev)) {
1408 		/* may be detached because parent is runtime-suspended */
1409 		if (dev->dev.parent)
1410 			pm_runtime_resume(dev->dev.parent);
1411 		if (!netif_device_present(dev))
1412 			return -ENODEV;
1413 	}
1414 
1415 	/* Block netpoll from trying to do any rx path servicing.
1416 	 * If we don't do this there is a chance ndo_poll_controller
1417 	 * or ndo_poll may be running while we open the device
1418 	 */
1419 	netpoll_poll_disable(dev);
1420 
1421 	ret = call_netdevice_notifiers_extack(NETDEV_PRE_UP, dev, extack);
1422 	ret = notifier_to_errno(ret);
1423 	if (ret)
1424 		return ret;
1425 
1426 	set_bit(__LINK_STATE_START, &dev->state);
1427 
1428 	if (ops->ndo_validate_addr)
1429 		ret = ops->ndo_validate_addr(dev);
1430 
1431 	if (!ret && ops->ndo_open)
1432 		ret = ops->ndo_open(dev);
1433 
1434 	netpoll_poll_enable(dev);
1435 
1436 	if (ret)
1437 		clear_bit(__LINK_STATE_START, &dev->state);
1438 	else {
1439 		dev->flags |= IFF_UP;
1440 		dev_set_rx_mode(dev);
1441 		dev_activate(dev);
1442 		add_device_randomness(dev->dev_addr, dev->addr_len);
1443 	}
1444 
1445 	return ret;
1446 }
1447 
1448 /**
1449  *	dev_open	- prepare an interface for use.
1450  *	@dev: device to open
1451  *	@extack: netlink extended ack
1452  *
1453  *	Takes a device from down to up state. The device's private open
1454  *	function is invoked and then the multicast lists are loaded. Finally
1455  *	the device is moved into the up state and a %NETDEV_UP message is
1456  *	sent to the netdev notifier chain.
1457  *
1458  *	Calling this function on an active interface is a nop. On a failure
1459  *	a negative errno code is returned.
1460  */
dev_open(struct net_device * dev,struct netlink_ext_ack * extack)1461 int dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1462 {
1463 	int ret;
1464 
1465 	if (dev->flags & IFF_UP)
1466 		return 0;
1467 
1468 	ret = __dev_open(dev, extack);
1469 	if (ret < 0)
1470 		return ret;
1471 
1472 	rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
1473 	call_netdevice_notifiers(NETDEV_UP, dev);
1474 
1475 	return ret;
1476 }
1477 EXPORT_SYMBOL(dev_open);
1478 
__dev_close_many(struct list_head * head)1479 static void __dev_close_many(struct list_head *head)
1480 {
1481 	struct net_device *dev;
1482 
1483 	ASSERT_RTNL();
1484 	might_sleep();
1485 
1486 	list_for_each_entry(dev, head, close_list) {
1487 		/* Temporarily disable netpoll until the interface is down */
1488 		netpoll_poll_disable(dev);
1489 
1490 		call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
1491 
1492 		clear_bit(__LINK_STATE_START, &dev->state);
1493 
1494 		/* Synchronize to scheduled poll. We cannot touch poll list, it
1495 		 * can be even on different cpu. So just clear netif_running().
1496 		 *
1497 		 * dev->stop() will invoke napi_disable() on all of it's
1498 		 * napi_struct instances on this device.
1499 		 */
1500 		smp_mb__after_atomic(); /* Commit netif_running(). */
1501 	}
1502 
1503 	dev_deactivate_many(head);
1504 
1505 	list_for_each_entry(dev, head, close_list) {
1506 		const struct net_device_ops *ops = dev->netdev_ops;
1507 
1508 		/*
1509 		 *	Call the device specific close. This cannot fail.
1510 		 *	Only if device is UP
1511 		 *
1512 		 *	We allow it to be called even after a DETACH hot-plug
1513 		 *	event.
1514 		 */
1515 		if (ops->ndo_stop)
1516 			ops->ndo_stop(dev);
1517 
1518 		dev->flags &= ~IFF_UP;
1519 		netpoll_poll_enable(dev);
1520 	}
1521 }
1522 
__dev_close(struct net_device * dev)1523 static void __dev_close(struct net_device *dev)
1524 {
1525 	LIST_HEAD(single);
1526 
1527 	list_add(&dev->close_list, &single);
1528 	__dev_close_many(&single);
1529 	list_del(&single);
1530 }
1531 
dev_close_many(struct list_head * head,bool unlink)1532 void dev_close_many(struct list_head *head, bool unlink)
1533 {
1534 	struct net_device *dev, *tmp;
1535 
1536 	/* Remove the devices that don't need to be closed */
1537 	list_for_each_entry_safe(dev, tmp, head, close_list)
1538 		if (!(dev->flags & IFF_UP))
1539 			list_del_init(&dev->close_list);
1540 
1541 	__dev_close_many(head);
1542 
1543 	list_for_each_entry_safe(dev, tmp, head, close_list) {
1544 		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
1545 		call_netdevice_notifiers(NETDEV_DOWN, dev);
1546 		if (unlink)
1547 			list_del_init(&dev->close_list);
1548 	}
1549 }
1550 EXPORT_SYMBOL(dev_close_many);
1551 
1552 /**
1553  *	dev_close - shutdown an interface.
1554  *	@dev: device to shutdown
1555  *
1556  *	This function moves an active device into down state. A
1557  *	%NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
1558  *	is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
1559  *	chain.
1560  */
dev_close(struct net_device * dev)1561 void dev_close(struct net_device *dev)
1562 {
1563 	if (dev->flags & IFF_UP) {
1564 		LIST_HEAD(single);
1565 
1566 		list_add(&dev->close_list, &single);
1567 		dev_close_many(&single, true);
1568 		list_del(&single);
1569 	}
1570 }
1571 EXPORT_SYMBOL(dev_close);
1572 
1573 
1574 /**
1575  *	dev_disable_lro - disable Large Receive Offload on a device
1576  *	@dev: device
1577  *
1578  *	Disable Large Receive Offload (LRO) on a net device.  Must be
1579  *	called under RTNL.  This is needed if received packets may be
1580  *	forwarded to another interface.
1581  */
dev_disable_lro(struct net_device * dev)1582 void dev_disable_lro(struct net_device *dev)
1583 {
1584 	struct net_device *lower_dev;
1585 	struct list_head *iter;
1586 
1587 	dev->wanted_features &= ~NETIF_F_LRO;
1588 	netdev_update_features(dev);
1589 
1590 	if (unlikely(dev->features & NETIF_F_LRO))
1591 		netdev_WARN(dev, "failed to disable LRO!\n");
1592 
1593 	netdev_for_each_lower_dev(dev, lower_dev, iter)
1594 		dev_disable_lro(lower_dev);
1595 }
1596 EXPORT_SYMBOL(dev_disable_lro);
1597 
1598 /**
1599  *	dev_disable_gro_hw - disable HW Generic Receive Offload on a device
1600  *	@dev: device
1601  *
1602  *	Disable HW Generic Receive Offload (GRO_HW) on a net device.  Must be
1603  *	called under RTNL.  This is needed if Generic XDP is installed on
1604  *	the device.
1605  */
dev_disable_gro_hw(struct net_device * dev)1606 static void dev_disable_gro_hw(struct net_device *dev)
1607 {
1608 	dev->wanted_features &= ~NETIF_F_GRO_HW;
1609 	netdev_update_features(dev);
1610 
1611 	if (unlikely(dev->features & NETIF_F_GRO_HW))
1612 		netdev_WARN(dev, "failed to disable GRO_HW!\n");
1613 }
1614 
netdev_cmd_to_name(enum netdev_cmd cmd)1615 const char *netdev_cmd_to_name(enum netdev_cmd cmd)
1616 {
1617 #define N(val) 						\
1618 	case NETDEV_##val:				\
1619 		return "NETDEV_" __stringify(val);
1620 	switch (cmd) {
1621 	N(UP) N(DOWN) N(REBOOT) N(CHANGE) N(REGISTER) N(UNREGISTER)
1622 	N(CHANGEMTU) N(CHANGEADDR) N(GOING_DOWN) N(CHANGENAME) N(FEAT_CHANGE)
1623 	N(BONDING_FAILOVER) N(PRE_UP) N(PRE_TYPE_CHANGE) N(POST_TYPE_CHANGE)
1624 	N(POST_INIT) N(RELEASE) N(NOTIFY_PEERS) N(JOIN) N(CHANGEUPPER)
1625 	N(RESEND_IGMP) N(PRECHANGEMTU) N(CHANGEINFODATA) N(BONDING_INFO)
1626 	N(PRECHANGEUPPER) N(CHANGELOWERSTATE) N(UDP_TUNNEL_PUSH_INFO)
1627 	N(UDP_TUNNEL_DROP_INFO) N(CHANGE_TX_QUEUE_LEN)
1628 	N(CVLAN_FILTER_PUSH_INFO) N(CVLAN_FILTER_DROP_INFO)
1629 	N(SVLAN_FILTER_PUSH_INFO) N(SVLAN_FILTER_DROP_INFO)
1630 	N(PRE_CHANGEADDR) N(OFFLOAD_XSTATS_ENABLE) N(OFFLOAD_XSTATS_DISABLE)
1631 	N(OFFLOAD_XSTATS_REPORT_USED) N(OFFLOAD_XSTATS_REPORT_DELTA)
1632 	}
1633 #undef N
1634 	return "UNKNOWN_NETDEV_EVENT";
1635 }
1636 EXPORT_SYMBOL_GPL(netdev_cmd_to_name);
1637 
call_netdevice_notifier(struct notifier_block * nb,unsigned long val,struct net_device * dev)1638 static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val,
1639 				   struct net_device *dev)
1640 {
1641 	struct netdev_notifier_info info = {
1642 		.dev = dev,
1643 	};
1644 
1645 	return nb->notifier_call(nb, val, &info);
1646 }
1647 
call_netdevice_register_notifiers(struct notifier_block * nb,struct net_device * dev)1648 static int call_netdevice_register_notifiers(struct notifier_block *nb,
1649 					     struct net_device *dev)
1650 {
1651 	int err;
1652 
1653 	err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev);
1654 	err = notifier_to_errno(err);
1655 	if (err)
1656 		return err;
1657 
1658 	if (!(dev->flags & IFF_UP))
1659 		return 0;
1660 
1661 	call_netdevice_notifier(nb, NETDEV_UP, dev);
1662 	return 0;
1663 }
1664 
call_netdevice_unregister_notifiers(struct notifier_block * nb,struct net_device * dev)1665 static void call_netdevice_unregister_notifiers(struct notifier_block *nb,
1666 						struct net_device *dev)
1667 {
1668 	if (dev->flags & IFF_UP) {
1669 		call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
1670 					dev);
1671 		call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1672 	}
1673 	call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1674 }
1675 
call_netdevice_register_net_notifiers(struct notifier_block * nb,struct net * net)1676 static int call_netdevice_register_net_notifiers(struct notifier_block *nb,
1677 						 struct net *net)
1678 {
1679 	struct net_device *dev;
1680 	int err;
1681 
1682 	for_each_netdev(net, dev) {
1683 		err = call_netdevice_register_notifiers(nb, dev);
1684 		if (err)
1685 			goto rollback;
1686 	}
1687 	return 0;
1688 
1689 rollback:
1690 	for_each_netdev_continue_reverse(net, dev)
1691 		call_netdevice_unregister_notifiers(nb, dev);
1692 	return err;
1693 }
1694 
call_netdevice_unregister_net_notifiers(struct notifier_block * nb,struct net * net)1695 static void call_netdevice_unregister_net_notifiers(struct notifier_block *nb,
1696 						    struct net *net)
1697 {
1698 	struct net_device *dev;
1699 
1700 	for_each_netdev(net, dev)
1701 		call_netdevice_unregister_notifiers(nb, dev);
1702 }
1703 
1704 static int dev_boot_phase = 1;
1705 
1706 /**
1707  * register_netdevice_notifier - register a network notifier block
1708  * @nb: notifier
1709  *
1710  * Register a notifier to be called when network device events occur.
1711  * The notifier passed is linked into the kernel structures and must
1712  * not be reused until it has been unregistered. A negative errno code
1713  * is returned on a failure.
1714  *
1715  * When registered all registration and up events are replayed
1716  * to the new notifier to allow device to have a race free
1717  * view of the network device list.
1718  */
1719 
register_netdevice_notifier(struct notifier_block * nb)1720 int register_netdevice_notifier(struct notifier_block *nb)
1721 {
1722 	struct net *net;
1723 	int err;
1724 
1725 	/* Close race with setup_net() and cleanup_net() */
1726 	down_write(&pernet_ops_rwsem);
1727 	rtnl_lock();
1728 	err = raw_notifier_chain_register(&netdev_chain, nb);
1729 	if (err)
1730 		goto unlock;
1731 	if (dev_boot_phase)
1732 		goto unlock;
1733 	for_each_net(net) {
1734 		err = call_netdevice_register_net_notifiers(nb, net);
1735 		if (err)
1736 			goto rollback;
1737 	}
1738 
1739 unlock:
1740 	rtnl_unlock();
1741 	up_write(&pernet_ops_rwsem);
1742 	return err;
1743 
1744 rollback:
1745 	for_each_net_continue_reverse(net)
1746 		call_netdevice_unregister_net_notifiers(nb, net);
1747 
1748 	raw_notifier_chain_unregister(&netdev_chain, nb);
1749 	goto unlock;
1750 }
1751 EXPORT_SYMBOL(register_netdevice_notifier);
1752 
1753 /**
1754  * unregister_netdevice_notifier - unregister a network notifier block
1755  * @nb: notifier
1756  *
1757  * Unregister a notifier previously registered by
1758  * register_netdevice_notifier(). The notifier is unlinked into the
1759  * kernel structures and may then be reused. A negative errno code
1760  * is returned on a failure.
1761  *
1762  * After unregistering unregister and down device events are synthesized
1763  * for all devices on the device list to the removed notifier to remove
1764  * the need for special case cleanup code.
1765  */
1766 
unregister_netdevice_notifier(struct notifier_block * nb)1767 int unregister_netdevice_notifier(struct notifier_block *nb)
1768 {
1769 	struct net *net;
1770 	int err;
1771 
1772 	/* Close race with setup_net() and cleanup_net() */
1773 	down_write(&pernet_ops_rwsem);
1774 	rtnl_lock();
1775 	err = raw_notifier_chain_unregister(&netdev_chain, nb);
1776 	if (err)
1777 		goto unlock;
1778 
1779 	for_each_net(net)
1780 		call_netdevice_unregister_net_notifiers(nb, net);
1781 
1782 unlock:
1783 	rtnl_unlock();
1784 	up_write(&pernet_ops_rwsem);
1785 	return err;
1786 }
1787 EXPORT_SYMBOL(unregister_netdevice_notifier);
1788 
__register_netdevice_notifier_net(struct net * net,struct notifier_block * nb,bool ignore_call_fail)1789 static int __register_netdevice_notifier_net(struct net *net,
1790 					     struct notifier_block *nb,
1791 					     bool ignore_call_fail)
1792 {
1793 	int err;
1794 
1795 	err = raw_notifier_chain_register(&net->netdev_chain, nb);
1796 	if (err)
1797 		return err;
1798 	if (dev_boot_phase)
1799 		return 0;
1800 
1801 	err = call_netdevice_register_net_notifiers(nb, net);
1802 	if (err && !ignore_call_fail)
1803 		goto chain_unregister;
1804 
1805 	return 0;
1806 
1807 chain_unregister:
1808 	raw_notifier_chain_unregister(&net->netdev_chain, nb);
1809 	return err;
1810 }
1811 
__unregister_netdevice_notifier_net(struct net * net,struct notifier_block * nb)1812 static int __unregister_netdevice_notifier_net(struct net *net,
1813 					       struct notifier_block *nb)
1814 {
1815 	int err;
1816 
1817 	err = raw_notifier_chain_unregister(&net->netdev_chain, nb);
1818 	if (err)
1819 		return err;
1820 
1821 	call_netdevice_unregister_net_notifiers(nb, net);
1822 	return 0;
1823 }
1824 
1825 /**
1826  * register_netdevice_notifier_net - register a per-netns network notifier block
1827  * @net: network namespace
1828  * @nb: notifier
1829  *
1830  * Register a notifier to be called when network device events occur.
1831  * The notifier passed is linked into the kernel structures and must
1832  * not be reused until it has been unregistered. A negative errno code
1833  * is returned on a failure.
1834  *
1835  * When registered all registration and up events are replayed
1836  * to the new notifier to allow device to have a race free
1837  * view of the network device list.
1838  */
1839 
register_netdevice_notifier_net(struct net * net,struct notifier_block * nb)1840 int register_netdevice_notifier_net(struct net *net, struct notifier_block *nb)
1841 {
1842 	int err;
1843 
1844 	rtnl_lock();
1845 	err = __register_netdevice_notifier_net(net, nb, false);
1846 	rtnl_unlock();
1847 	return err;
1848 }
1849 EXPORT_SYMBOL(register_netdevice_notifier_net);
1850 
1851 /**
1852  * unregister_netdevice_notifier_net - unregister a per-netns
1853  *                                     network notifier block
1854  * @net: network namespace
1855  * @nb: notifier
1856  *
1857  * Unregister a notifier previously registered by
1858  * register_netdevice_notifier(). The notifier is unlinked into the
1859  * kernel structures and may then be reused. A negative errno code
1860  * is returned on a failure.
1861  *
1862  * After unregistering unregister and down device events are synthesized
1863  * for all devices on the device list to the removed notifier to remove
1864  * the need for special case cleanup code.
1865  */
1866 
unregister_netdevice_notifier_net(struct net * net,struct notifier_block * nb)1867 int unregister_netdevice_notifier_net(struct net *net,
1868 				      struct notifier_block *nb)
1869 {
1870 	int err;
1871 
1872 	rtnl_lock();
1873 	err = __unregister_netdevice_notifier_net(net, nb);
1874 	rtnl_unlock();
1875 	return err;
1876 }
1877 EXPORT_SYMBOL(unregister_netdevice_notifier_net);
1878 
register_netdevice_notifier_dev_net(struct net_device * dev,struct notifier_block * nb,struct netdev_net_notifier * nn)1879 int register_netdevice_notifier_dev_net(struct net_device *dev,
1880 					struct notifier_block *nb,
1881 					struct netdev_net_notifier *nn)
1882 {
1883 	int err;
1884 
1885 	rtnl_lock();
1886 	err = __register_netdevice_notifier_net(dev_net(dev), nb, false);
1887 	if (!err) {
1888 		nn->nb = nb;
1889 		list_add(&nn->list, &dev->net_notifier_list);
1890 	}
1891 	rtnl_unlock();
1892 	return err;
1893 }
1894 EXPORT_SYMBOL(register_netdevice_notifier_dev_net);
1895 
unregister_netdevice_notifier_dev_net(struct net_device * dev,struct notifier_block * nb,struct netdev_net_notifier * nn)1896 int unregister_netdevice_notifier_dev_net(struct net_device *dev,
1897 					  struct notifier_block *nb,
1898 					  struct netdev_net_notifier *nn)
1899 {
1900 	int err;
1901 
1902 	rtnl_lock();
1903 	list_del(&nn->list);
1904 	err = __unregister_netdevice_notifier_net(dev_net(dev), nb);
1905 	rtnl_unlock();
1906 	return err;
1907 }
1908 EXPORT_SYMBOL(unregister_netdevice_notifier_dev_net);
1909 
move_netdevice_notifiers_dev_net(struct net_device * dev,struct net * net)1910 static void move_netdevice_notifiers_dev_net(struct net_device *dev,
1911 					     struct net *net)
1912 {
1913 	struct netdev_net_notifier *nn;
1914 
1915 	list_for_each_entry(nn, &dev->net_notifier_list, list) {
1916 		__unregister_netdevice_notifier_net(dev_net(dev), nn->nb);
1917 		__register_netdevice_notifier_net(net, nn->nb, true);
1918 	}
1919 }
1920 
1921 /**
1922  *	call_netdevice_notifiers_info - call all network notifier blocks
1923  *	@val: value passed unmodified to notifier function
1924  *	@info: notifier information data
1925  *
1926  *	Call all network notifier blocks.  Parameters and return value
1927  *	are as for raw_notifier_call_chain().
1928  */
1929 
call_netdevice_notifiers_info(unsigned long val,struct netdev_notifier_info * info)1930 static int call_netdevice_notifiers_info(unsigned long val,
1931 					 struct netdev_notifier_info *info)
1932 {
1933 	struct net *net = dev_net(info->dev);
1934 	int ret;
1935 
1936 	ASSERT_RTNL();
1937 
1938 	/* Run per-netns notifier block chain first, then run the global one.
1939 	 * Hopefully, one day, the global one is going to be removed after
1940 	 * all notifier block registrators get converted to be per-netns.
1941 	 */
1942 	ret = raw_notifier_call_chain(&net->netdev_chain, val, info);
1943 	if (ret & NOTIFY_STOP_MASK)
1944 		return ret;
1945 	return raw_notifier_call_chain(&netdev_chain, val, info);
1946 }
1947 
1948 /**
1949  *	call_netdevice_notifiers_info_robust - call per-netns notifier blocks
1950  *	                                       for and rollback on error
1951  *	@val_up: value passed unmodified to notifier function
1952  *	@val_down: value passed unmodified to the notifier function when
1953  *	           recovering from an error on @val_up
1954  *	@info: notifier information data
1955  *
1956  *	Call all per-netns network notifier blocks, but not notifier blocks on
1957  *	the global notifier chain. Parameters and return value are as for
1958  *	raw_notifier_call_chain_robust().
1959  */
1960 
1961 static int
call_netdevice_notifiers_info_robust(unsigned long val_up,unsigned long val_down,struct netdev_notifier_info * info)1962 call_netdevice_notifiers_info_robust(unsigned long val_up,
1963 				     unsigned long val_down,
1964 				     struct netdev_notifier_info *info)
1965 {
1966 	struct net *net = dev_net(info->dev);
1967 
1968 	ASSERT_RTNL();
1969 
1970 	return raw_notifier_call_chain_robust(&net->netdev_chain,
1971 					      val_up, val_down, info);
1972 }
1973 
call_netdevice_notifiers_extack(unsigned long val,struct net_device * dev,struct netlink_ext_ack * extack)1974 static int call_netdevice_notifiers_extack(unsigned long val,
1975 					   struct net_device *dev,
1976 					   struct netlink_ext_ack *extack)
1977 {
1978 	struct netdev_notifier_info info = {
1979 		.dev = dev,
1980 		.extack = extack,
1981 	};
1982 
1983 	return call_netdevice_notifiers_info(val, &info);
1984 }
1985 
1986 /**
1987  *	call_netdevice_notifiers - call all network notifier blocks
1988  *      @val: value passed unmodified to notifier function
1989  *      @dev: net_device pointer passed unmodified to notifier function
1990  *
1991  *	Call all network notifier blocks.  Parameters and return value
1992  *	are as for raw_notifier_call_chain().
1993  */
1994 
call_netdevice_notifiers(unsigned long val,struct net_device * dev)1995 int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
1996 {
1997 	return call_netdevice_notifiers_extack(val, dev, NULL);
1998 }
1999 EXPORT_SYMBOL(call_netdevice_notifiers);
2000 
2001 /**
2002  *	call_netdevice_notifiers_mtu - call all network notifier blocks
2003  *	@val: value passed unmodified to notifier function
2004  *	@dev: net_device pointer passed unmodified to notifier function
2005  *	@arg: additional u32 argument passed to the notifier function
2006  *
2007  *	Call all network notifier blocks.  Parameters and return value
2008  *	are as for raw_notifier_call_chain().
2009  */
call_netdevice_notifiers_mtu(unsigned long val,struct net_device * dev,u32 arg)2010 static int call_netdevice_notifiers_mtu(unsigned long val,
2011 					struct net_device *dev, u32 arg)
2012 {
2013 	struct netdev_notifier_info_ext info = {
2014 		.info.dev = dev,
2015 		.ext.mtu = arg,
2016 	};
2017 
2018 	BUILD_BUG_ON(offsetof(struct netdev_notifier_info_ext, info) != 0);
2019 
2020 	return call_netdevice_notifiers_info(val, &info.info);
2021 }
2022 
2023 #ifdef CONFIG_NET_INGRESS
2024 static DEFINE_STATIC_KEY_FALSE(ingress_needed_key);
2025 
net_inc_ingress_queue(void)2026 void net_inc_ingress_queue(void)
2027 {
2028 	static_branch_inc(&ingress_needed_key);
2029 }
2030 EXPORT_SYMBOL_GPL(net_inc_ingress_queue);
2031 
net_dec_ingress_queue(void)2032 void net_dec_ingress_queue(void)
2033 {
2034 	static_branch_dec(&ingress_needed_key);
2035 }
2036 EXPORT_SYMBOL_GPL(net_dec_ingress_queue);
2037 #endif
2038 
2039 #ifdef CONFIG_NET_EGRESS
2040 static DEFINE_STATIC_KEY_FALSE(egress_needed_key);
2041 
net_inc_egress_queue(void)2042 void net_inc_egress_queue(void)
2043 {
2044 	static_branch_inc(&egress_needed_key);
2045 }
2046 EXPORT_SYMBOL_GPL(net_inc_egress_queue);
2047 
net_dec_egress_queue(void)2048 void net_dec_egress_queue(void)
2049 {
2050 	static_branch_dec(&egress_needed_key);
2051 }
2052 EXPORT_SYMBOL_GPL(net_dec_egress_queue);
2053 #endif
2054 
2055 DEFINE_STATIC_KEY_FALSE(netstamp_needed_key);
2056 EXPORT_SYMBOL(netstamp_needed_key);
2057 #ifdef CONFIG_JUMP_LABEL
2058 static atomic_t netstamp_needed_deferred;
2059 static atomic_t netstamp_wanted;
netstamp_clear(struct work_struct * work)2060 static void netstamp_clear(struct work_struct *work)
2061 {
2062 	int deferred = atomic_xchg(&netstamp_needed_deferred, 0);
2063 	int wanted;
2064 
2065 	wanted = atomic_add_return(deferred, &netstamp_wanted);
2066 	if (wanted > 0)
2067 		static_branch_enable(&netstamp_needed_key);
2068 	else
2069 		static_branch_disable(&netstamp_needed_key);
2070 }
2071 static DECLARE_WORK(netstamp_work, netstamp_clear);
2072 #endif
2073 
net_enable_timestamp(void)2074 void net_enable_timestamp(void)
2075 {
2076 #ifdef CONFIG_JUMP_LABEL
2077 	int wanted;
2078 
2079 	while (1) {
2080 		wanted = atomic_read(&netstamp_wanted);
2081 		if (wanted <= 0)
2082 			break;
2083 		if (atomic_cmpxchg(&netstamp_wanted, wanted, wanted + 1) == wanted)
2084 			return;
2085 	}
2086 	atomic_inc(&netstamp_needed_deferred);
2087 	schedule_work(&netstamp_work);
2088 #else
2089 	static_branch_inc(&netstamp_needed_key);
2090 #endif
2091 }
2092 EXPORT_SYMBOL(net_enable_timestamp);
2093 
net_disable_timestamp(void)2094 void net_disable_timestamp(void)
2095 {
2096 #ifdef CONFIG_JUMP_LABEL
2097 	int wanted;
2098 
2099 	while (1) {
2100 		wanted = atomic_read(&netstamp_wanted);
2101 		if (wanted <= 1)
2102 			break;
2103 		if (atomic_cmpxchg(&netstamp_wanted, wanted, wanted - 1) == wanted)
2104 			return;
2105 	}
2106 	atomic_dec(&netstamp_needed_deferred);
2107 	schedule_work(&netstamp_work);
2108 #else
2109 	static_branch_dec(&netstamp_needed_key);
2110 #endif
2111 }
2112 EXPORT_SYMBOL(net_disable_timestamp);
2113 
net_timestamp_set(struct sk_buff * skb)2114 static inline void net_timestamp_set(struct sk_buff *skb)
2115 {
2116 	skb->tstamp = 0;
2117 	skb->mono_delivery_time = 0;
2118 	if (static_branch_unlikely(&netstamp_needed_key))
2119 		skb->tstamp = ktime_get_real();
2120 }
2121 
2122 #define net_timestamp_check(COND, SKB)				\
2123 	if (static_branch_unlikely(&netstamp_needed_key)) {	\
2124 		if ((COND) && !(SKB)->tstamp)			\
2125 			(SKB)->tstamp = ktime_get_real();	\
2126 	}							\
2127 
is_skb_forwardable(const struct net_device * dev,const struct sk_buff * skb)2128 bool is_skb_forwardable(const struct net_device *dev, const struct sk_buff *skb)
2129 {
2130 	return __is_skb_forwardable(dev, skb, true);
2131 }
2132 EXPORT_SYMBOL_GPL(is_skb_forwardable);
2133 
__dev_forward_skb2(struct net_device * dev,struct sk_buff * skb,bool check_mtu)2134 static int __dev_forward_skb2(struct net_device *dev, struct sk_buff *skb,
2135 			      bool check_mtu)
2136 {
2137 	int ret = ____dev_forward_skb(dev, skb, check_mtu);
2138 
2139 	if (likely(!ret)) {
2140 		skb->protocol = eth_type_trans(skb, dev);
2141 		skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
2142 	}
2143 
2144 	return ret;
2145 }
2146 
__dev_forward_skb(struct net_device * dev,struct sk_buff * skb)2147 int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2148 {
2149 	return __dev_forward_skb2(dev, skb, true);
2150 }
2151 EXPORT_SYMBOL_GPL(__dev_forward_skb);
2152 
2153 /**
2154  * dev_forward_skb - loopback an skb to another netif
2155  *
2156  * @dev: destination network device
2157  * @skb: buffer to forward
2158  *
2159  * return values:
2160  *	NET_RX_SUCCESS	(no congestion)
2161  *	NET_RX_DROP     (packet was dropped, but freed)
2162  *
2163  * dev_forward_skb can be used for injecting an skb from the
2164  * start_xmit function of one device into the receive queue
2165  * of another device.
2166  *
2167  * The receiving device may be in another namespace, so
2168  * we have to clear all information in the skb that could
2169  * impact namespace isolation.
2170  */
dev_forward_skb(struct net_device * dev,struct sk_buff * skb)2171 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2172 {
2173 	return __dev_forward_skb(dev, skb) ?: netif_rx_internal(skb);
2174 }
2175 EXPORT_SYMBOL_GPL(dev_forward_skb);
2176 
dev_forward_skb_nomtu(struct net_device * dev,struct sk_buff * skb)2177 int dev_forward_skb_nomtu(struct net_device *dev, struct sk_buff *skb)
2178 {
2179 	return __dev_forward_skb2(dev, skb, false) ?: netif_rx_internal(skb);
2180 }
2181 
deliver_skb(struct sk_buff * skb,struct packet_type * pt_prev,struct net_device * orig_dev)2182 static inline int deliver_skb(struct sk_buff *skb,
2183 			      struct packet_type *pt_prev,
2184 			      struct net_device *orig_dev)
2185 {
2186 	if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
2187 		return -ENOMEM;
2188 	refcount_inc(&skb->users);
2189 	return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
2190 }
2191 
deliver_ptype_list_skb(struct sk_buff * skb,struct packet_type ** pt,struct net_device * orig_dev,__be16 type,struct list_head * ptype_list)2192 static inline void deliver_ptype_list_skb(struct sk_buff *skb,
2193 					  struct packet_type **pt,
2194 					  struct net_device *orig_dev,
2195 					  __be16 type,
2196 					  struct list_head *ptype_list)
2197 {
2198 	struct packet_type *ptype, *pt_prev = *pt;
2199 
2200 	list_for_each_entry_rcu(ptype, ptype_list, list) {
2201 		if (ptype->type != type)
2202 			continue;
2203 		if (pt_prev)
2204 			deliver_skb(skb, pt_prev, orig_dev);
2205 		pt_prev = ptype;
2206 	}
2207 	*pt = pt_prev;
2208 }
2209 
skb_loop_sk(struct packet_type * ptype,struct sk_buff * skb)2210 static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
2211 {
2212 	if (!ptype->af_packet_priv || !skb->sk)
2213 		return false;
2214 
2215 	if (ptype->id_match)
2216 		return ptype->id_match(ptype, skb->sk);
2217 	else if ((struct sock *)ptype->af_packet_priv == skb->sk)
2218 		return true;
2219 
2220 	return false;
2221 }
2222 
2223 /**
2224  * dev_nit_active - return true if any network interface taps are in use
2225  *
2226  * @dev: network device to check for the presence of taps
2227  */
dev_nit_active(struct net_device * dev)2228 bool dev_nit_active(struct net_device *dev)
2229 {
2230 	return !list_empty(&ptype_all) || !list_empty(&dev->ptype_all);
2231 }
2232 EXPORT_SYMBOL_GPL(dev_nit_active);
2233 
2234 /*
2235  *	Support routine. Sends outgoing frames to any network
2236  *	taps currently in use.
2237  */
2238 
dev_queue_xmit_nit(struct sk_buff * skb,struct net_device * dev)2239 void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
2240 {
2241 	struct packet_type *ptype;
2242 	struct sk_buff *skb2 = NULL;
2243 	struct packet_type *pt_prev = NULL;
2244 	struct list_head *ptype_list = &ptype_all;
2245 
2246 	rcu_read_lock();
2247 again:
2248 	list_for_each_entry_rcu(ptype, ptype_list, list) {
2249 		if (ptype->ignore_outgoing)
2250 			continue;
2251 
2252 		/* Never send packets back to the socket
2253 		 * they originated from - MvS (miquels@drinkel.ow.org)
2254 		 */
2255 		if (skb_loop_sk(ptype, skb))
2256 			continue;
2257 
2258 		if (pt_prev) {
2259 			deliver_skb(skb2, pt_prev, skb->dev);
2260 			pt_prev = ptype;
2261 			continue;
2262 		}
2263 
2264 		/* need to clone skb, done only once */
2265 		skb2 = skb_clone(skb, GFP_ATOMIC);
2266 		if (!skb2)
2267 			goto out_unlock;
2268 
2269 		net_timestamp_set(skb2);
2270 
2271 		/* skb->nh should be correctly
2272 		 * set by sender, so that the second statement is
2273 		 * just protection against buggy protocols.
2274 		 */
2275 		skb_reset_mac_header(skb2);
2276 
2277 		if (skb_network_header(skb2) < skb2->data ||
2278 		    skb_network_header(skb2) > skb_tail_pointer(skb2)) {
2279 			net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
2280 					     ntohs(skb2->protocol),
2281 					     dev->name);
2282 			skb_reset_network_header(skb2);
2283 		}
2284 
2285 		skb2->transport_header = skb2->network_header;
2286 		skb2->pkt_type = PACKET_OUTGOING;
2287 		pt_prev = ptype;
2288 	}
2289 
2290 	if (ptype_list == &ptype_all) {
2291 		ptype_list = &dev->ptype_all;
2292 		goto again;
2293 	}
2294 out_unlock:
2295 	if (pt_prev) {
2296 		if (!skb_orphan_frags_rx(skb2, GFP_ATOMIC))
2297 			pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
2298 		else
2299 			kfree_skb(skb2);
2300 	}
2301 	rcu_read_unlock();
2302 }
2303 EXPORT_SYMBOL_GPL(dev_queue_xmit_nit);
2304 
2305 /**
2306  * netif_setup_tc - Handle tc mappings on real_num_tx_queues change
2307  * @dev: Network device
2308  * @txq: number of queues available
2309  *
2310  * If real_num_tx_queues is changed the tc mappings may no longer be
2311  * valid. To resolve this verify the tc mapping remains valid and if
2312  * not NULL the mapping. With no priorities mapping to this
2313  * offset/count pair it will no longer be used. In the worst case TC0
2314  * is invalid nothing can be done so disable priority mappings. If is
2315  * expected that drivers will fix this mapping if they can before
2316  * calling netif_set_real_num_tx_queues.
2317  */
netif_setup_tc(struct net_device * dev,unsigned int txq)2318 static void netif_setup_tc(struct net_device *dev, unsigned int txq)
2319 {
2320 	int i;
2321 	struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2322 
2323 	/* If TC0 is invalidated disable TC mapping */
2324 	if (tc->offset + tc->count > txq) {
2325 		netdev_warn(dev, "Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
2326 		dev->num_tc = 0;
2327 		return;
2328 	}
2329 
2330 	/* Invalidated prio to tc mappings set to TC0 */
2331 	for (i = 1; i < TC_BITMASK + 1; i++) {
2332 		int q = netdev_get_prio_tc_map(dev, i);
2333 
2334 		tc = &dev->tc_to_txq[q];
2335 		if (tc->offset + tc->count > txq) {
2336 			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",
2337 				    i, q);
2338 			netdev_set_prio_tc_map(dev, i, 0);
2339 		}
2340 	}
2341 }
2342 
netdev_txq_to_tc(struct net_device * dev,unsigned int txq)2343 int netdev_txq_to_tc(struct net_device *dev, unsigned int txq)
2344 {
2345 	if (dev->num_tc) {
2346 		struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2347 		int i;
2348 
2349 		/* walk through the TCs and see if it falls into any of them */
2350 		for (i = 0; i < TC_MAX_QUEUE; i++, tc++) {
2351 			if ((txq - tc->offset) < tc->count)
2352 				return i;
2353 		}
2354 
2355 		/* didn't find it, just return -1 to indicate no match */
2356 		return -1;
2357 	}
2358 
2359 	return 0;
2360 }
2361 EXPORT_SYMBOL(netdev_txq_to_tc);
2362 
2363 #ifdef CONFIG_XPS
2364 static struct static_key xps_needed __read_mostly;
2365 static struct static_key xps_rxqs_needed __read_mostly;
2366 static DEFINE_MUTEX(xps_map_mutex);
2367 #define xmap_dereference(P)		\
2368 	rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
2369 
remove_xps_queue(struct xps_dev_maps * dev_maps,struct xps_dev_maps * old_maps,int tci,u16 index)2370 static bool remove_xps_queue(struct xps_dev_maps *dev_maps,
2371 			     struct xps_dev_maps *old_maps, int tci, u16 index)
2372 {
2373 	struct xps_map *map = NULL;
2374 	int pos;
2375 
2376 	if (dev_maps)
2377 		map = xmap_dereference(dev_maps->attr_map[tci]);
2378 	if (!map)
2379 		return false;
2380 
2381 	for (pos = map->len; pos--;) {
2382 		if (map->queues[pos] != index)
2383 			continue;
2384 
2385 		if (map->len > 1) {
2386 			map->queues[pos] = map->queues[--map->len];
2387 			break;
2388 		}
2389 
2390 		if (old_maps)
2391 			RCU_INIT_POINTER(old_maps->attr_map[tci], NULL);
2392 		RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2393 		kfree_rcu(map, rcu);
2394 		return false;
2395 	}
2396 
2397 	return true;
2398 }
2399 
remove_xps_queue_cpu(struct net_device * dev,struct xps_dev_maps * dev_maps,int cpu,u16 offset,u16 count)2400 static bool remove_xps_queue_cpu(struct net_device *dev,
2401 				 struct xps_dev_maps *dev_maps,
2402 				 int cpu, u16 offset, u16 count)
2403 {
2404 	int num_tc = dev_maps->num_tc;
2405 	bool active = false;
2406 	int tci;
2407 
2408 	for (tci = cpu * num_tc; num_tc--; tci++) {
2409 		int i, j;
2410 
2411 		for (i = count, j = offset; i--; j++) {
2412 			if (!remove_xps_queue(dev_maps, NULL, tci, j))
2413 				break;
2414 		}
2415 
2416 		active |= i < 0;
2417 	}
2418 
2419 	return active;
2420 }
2421 
reset_xps_maps(struct net_device * dev,struct xps_dev_maps * dev_maps,enum xps_map_type type)2422 static void reset_xps_maps(struct net_device *dev,
2423 			   struct xps_dev_maps *dev_maps,
2424 			   enum xps_map_type type)
2425 {
2426 	static_key_slow_dec_cpuslocked(&xps_needed);
2427 	if (type == XPS_RXQS)
2428 		static_key_slow_dec_cpuslocked(&xps_rxqs_needed);
2429 
2430 	RCU_INIT_POINTER(dev->xps_maps[type], NULL);
2431 
2432 	kfree_rcu(dev_maps, rcu);
2433 }
2434 
clean_xps_maps(struct net_device * dev,enum xps_map_type type,u16 offset,u16 count)2435 static void clean_xps_maps(struct net_device *dev, enum xps_map_type type,
2436 			   u16 offset, u16 count)
2437 {
2438 	struct xps_dev_maps *dev_maps;
2439 	bool active = false;
2440 	int i, j;
2441 
2442 	dev_maps = xmap_dereference(dev->xps_maps[type]);
2443 	if (!dev_maps)
2444 		return;
2445 
2446 	for (j = 0; j < dev_maps->nr_ids; j++)
2447 		active |= remove_xps_queue_cpu(dev, dev_maps, j, offset, count);
2448 	if (!active)
2449 		reset_xps_maps(dev, dev_maps, type);
2450 
2451 	if (type == XPS_CPUS) {
2452 		for (i = offset + (count - 1); count--; i--)
2453 			netdev_queue_numa_node_write(
2454 				netdev_get_tx_queue(dev, i), NUMA_NO_NODE);
2455 	}
2456 }
2457 
netif_reset_xps_queues(struct net_device * dev,u16 offset,u16 count)2458 static void netif_reset_xps_queues(struct net_device *dev, u16 offset,
2459 				   u16 count)
2460 {
2461 	if (!static_key_false(&xps_needed))
2462 		return;
2463 
2464 	cpus_read_lock();
2465 	mutex_lock(&xps_map_mutex);
2466 
2467 	if (static_key_false(&xps_rxqs_needed))
2468 		clean_xps_maps(dev, XPS_RXQS, offset, count);
2469 
2470 	clean_xps_maps(dev, XPS_CPUS, offset, count);
2471 
2472 	mutex_unlock(&xps_map_mutex);
2473 	cpus_read_unlock();
2474 }
2475 
netif_reset_xps_queues_gt(struct net_device * dev,u16 index)2476 static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
2477 {
2478 	netif_reset_xps_queues(dev, index, dev->num_tx_queues - index);
2479 }
2480 
expand_xps_map(struct xps_map * map,int attr_index,u16 index,bool is_rxqs_map)2481 static struct xps_map *expand_xps_map(struct xps_map *map, int attr_index,
2482 				      u16 index, bool is_rxqs_map)
2483 {
2484 	struct xps_map *new_map;
2485 	int alloc_len = XPS_MIN_MAP_ALLOC;
2486 	int i, pos;
2487 
2488 	for (pos = 0; map && pos < map->len; pos++) {
2489 		if (map->queues[pos] != index)
2490 			continue;
2491 		return map;
2492 	}
2493 
2494 	/* Need to add tx-queue to this CPU's/rx-queue's existing map */
2495 	if (map) {
2496 		if (pos < map->alloc_len)
2497 			return map;
2498 
2499 		alloc_len = map->alloc_len * 2;
2500 	}
2501 
2502 	/* Need to allocate new map to store tx-queue on this CPU's/rx-queue's
2503 	 *  map
2504 	 */
2505 	if (is_rxqs_map)
2506 		new_map = kzalloc(XPS_MAP_SIZE(alloc_len), GFP_KERNEL);
2507 	else
2508 		new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len), GFP_KERNEL,
2509 				       cpu_to_node(attr_index));
2510 	if (!new_map)
2511 		return NULL;
2512 
2513 	for (i = 0; i < pos; i++)
2514 		new_map->queues[i] = map->queues[i];
2515 	new_map->alloc_len = alloc_len;
2516 	new_map->len = pos;
2517 
2518 	return new_map;
2519 }
2520 
2521 /* 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)2522 static void xps_copy_dev_maps(struct xps_dev_maps *dev_maps,
2523 			      struct xps_dev_maps *new_dev_maps, int index,
2524 			      int tc, bool skip_tc)
2525 {
2526 	int i, tci = index * dev_maps->num_tc;
2527 	struct xps_map *map;
2528 
2529 	/* copy maps belonging to foreign traffic classes */
2530 	for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2531 		if (i == tc && skip_tc)
2532 			continue;
2533 
2534 		/* fill in the new device map from the old device map */
2535 		map = xmap_dereference(dev_maps->attr_map[tci]);
2536 		RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2537 	}
2538 }
2539 
2540 /* 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)2541 int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask,
2542 			  u16 index, enum xps_map_type type)
2543 {
2544 	struct xps_dev_maps *dev_maps, *new_dev_maps = NULL, *old_dev_maps = NULL;
2545 	const unsigned long *online_mask = NULL;
2546 	bool active = false, copy = false;
2547 	int i, j, tci, numa_node_id = -2;
2548 	int maps_sz, num_tc = 1, tc = 0;
2549 	struct xps_map *map, *new_map;
2550 	unsigned int nr_ids;
2551 
2552 	if (dev->num_tc) {
2553 		/* Do not allow XPS on subordinate device directly */
2554 		num_tc = dev->num_tc;
2555 		if (num_tc < 0)
2556 			return -EINVAL;
2557 
2558 		/* If queue belongs to subordinate dev use its map */
2559 		dev = netdev_get_tx_queue(dev, index)->sb_dev ? : dev;
2560 
2561 		tc = netdev_txq_to_tc(dev, index);
2562 		if (tc < 0)
2563 			return -EINVAL;
2564 	}
2565 
2566 	mutex_lock(&xps_map_mutex);
2567 
2568 	dev_maps = xmap_dereference(dev->xps_maps[type]);
2569 	if (type == XPS_RXQS) {
2570 		maps_sz = XPS_RXQ_DEV_MAPS_SIZE(num_tc, dev->num_rx_queues);
2571 		nr_ids = dev->num_rx_queues;
2572 	} else {
2573 		maps_sz = XPS_CPU_DEV_MAPS_SIZE(num_tc);
2574 		if (num_possible_cpus() > 1)
2575 			online_mask = cpumask_bits(cpu_online_mask);
2576 		nr_ids = nr_cpu_ids;
2577 	}
2578 
2579 	if (maps_sz < L1_CACHE_BYTES)
2580 		maps_sz = L1_CACHE_BYTES;
2581 
2582 	/* The old dev_maps could be larger or smaller than the one we're
2583 	 * setting up now, as dev->num_tc or nr_ids could have been updated in
2584 	 * between. We could try to be smart, but let's be safe instead and only
2585 	 * copy foreign traffic classes if the two map sizes match.
2586 	 */
2587 	if (dev_maps &&
2588 	    dev_maps->num_tc == num_tc && dev_maps->nr_ids == nr_ids)
2589 		copy = true;
2590 
2591 	/* allocate memory for queue storage */
2592 	for (j = -1; j = netif_attrmask_next_and(j, online_mask, mask, nr_ids),
2593 	     j < nr_ids;) {
2594 		if (!new_dev_maps) {
2595 			new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
2596 			if (!new_dev_maps) {
2597 				mutex_unlock(&xps_map_mutex);
2598 				return -ENOMEM;
2599 			}
2600 
2601 			new_dev_maps->nr_ids = nr_ids;
2602 			new_dev_maps->num_tc = num_tc;
2603 		}
2604 
2605 		tci = j * num_tc + tc;
2606 		map = copy ? xmap_dereference(dev_maps->attr_map[tci]) : NULL;
2607 
2608 		map = expand_xps_map(map, j, index, type == XPS_RXQS);
2609 		if (!map)
2610 			goto error;
2611 
2612 		RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2613 	}
2614 
2615 	if (!new_dev_maps)
2616 		goto out_no_new_maps;
2617 
2618 	if (!dev_maps) {
2619 		/* Increment static keys at most once per type */
2620 		static_key_slow_inc_cpuslocked(&xps_needed);
2621 		if (type == XPS_RXQS)
2622 			static_key_slow_inc_cpuslocked(&xps_rxqs_needed);
2623 	}
2624 
2625 	for (j = 0; j < nr_ids; j++) {
2626 		bool skip_tc = false;
2627 
2628 		tci = j * num_tc + tc;
2629 		if (netif_attr_test_mask(j, mask, nr_ids) &&
2630 		    netif_attr_test_online(j, online_mask, nr_ids)) {
2631 			/* add tx-queue to CPU/rx-queue maps */
2632 			int pos = 0;
2633 
2634 			skip_tc = true;
2635 
2636 			map = xmap_dereference(new_dev_maps->attr_map[tci]);
2637 			while ((pos < map->len) && (map->queues[pos] != index))
2638 				pos++;
2639 
2640 			if (pos == map->len)
2641 				map->queues[map->len++] = index;
2642 #ifdef CONFIG_NUMA
2643 			if (type == XPS_CPUS) {
2644 				if (numa_node_id == -2)
2645 					numa_node_id = cpu_to_node(j);
2646 				else if (numa_node_id != cpu_to_node(j))
2647 					numa_node_id = -1;
2648 			}
2649 #endif
2650 		}
2651 
2652 		if (copy)
2653 			xps_copy_dev_maps(dev_maps, new_dev_maps, j, tc,
2654 					  skip_tc);
2655 	}
2656 
2657 	rcu_assign_pointer(dev->xps_maps[type], new_dev_maps);
2658 
2659 	/* Cleanup old maps */
2660 	if (!dev_maps)
2661 		goto out_no_old_maps;
2662 
2663 	for (j = 0; j < dev_maps->nr_ids; j++) {
2664 		for (i = num_tc, tci = j * dev_maps->num_tc; i--; tci++) {
2665 			map = xmap_dereference(dev_maps->attr_map[tci]);
2666 			if (!map)
2667 				continue;
2668 
2669 			if (copy) {
2670 				new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2671 				if (map == new_map)
2672 					continue;
2673 			}
2674 
2675 			RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2676 			kfree_rcu(map, rcu);
2677 		}
2678 	}
2679 
2680 	old_dev_maps = dev_maps;
2681 
2682 out_no_old_maps:
2683 	dev_maps = new_dev_maps;
2684 	active = true;
2685 
2686 out_no_new_maps:
2687 	if (type == XPS_CPUS)
2688 		/* update Tx queue numa node */
2689 		netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
2690 					     (numa_node_id >= 0) ?
2691 					     numa_node_id : NUMA_NO_NODE);
2692 
2693 	if (!dev_maps)
2694 		goto out_no_maps;
2695 
2696 	/* removes tx-queue from unused CPUs/rx-queues */
2697 	for (j = 0; j < dev_maps->nr_ids; j++) {
2698 		tci = j * dev_maps->num_tc;
2699 
2700 		for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2701 			if (i == tc &&
2702 			    netif_attr_test_mask(j, mask, dev_maps->nr_ids) &&
2703 			    netif_attr_test_online(j, online_mask, dev_maps->nr_ids))
2704 				continue;
2705 
2706 			active |= remove_xps_queue(dev_maps,
2707 						   copy ? old_dev_maps : NULL,
2708 						   tci, index);
2709 		}
2710 	}
2711 
2712 	if (old_dev_maps)
2713 		kfree_rcu(old_dev_maps, rcu);
2714 
2715 	/* free map if not active */
2716 	if (!active)
2717 		reset_xps_maps(dev, dev_maps, type);
2718 
2719 out_no_maps:
2720 	mutex_unlock(&xps_map_mutex);
2721 
2722 	return 0;
2723 error:
2724 	/* remove any maps that we added */
2725 	for (j = 0; j < nr_ids; j++) {
2726 		for (i = num_tc, tci = j * num_tc; i--; tci++) {
2727 			new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2728 			map = copy ?
2729 			      xmap_dereference(dev_maps->attr_map[tci]) :
2730 			      NULL;
2731 			if (new_map && new_map != map)
2732 				kfree(new_map);
2733 		}
2734 	}
2735 
2736 	mutex_unlock(&xps_map_mutex);
2737 
2738 	kfree(new_dev_maps);
2739 	return -ENOMEM;
2740 }
2741 EXPORT_SYMBOL_GPL(__netif_set_xps_queue);
2742 
netif_set_xps_queue(struct net_device * dev,const struct cpumask * mask,u16 index)2743 int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask,
2744 			u16 index)
2745 {
2746 	int ret;
2747 
2748 	cpus_read_lock();
2749 	ret =  __netif_set_xps_queue(dev, cpumask_bits(mask), index, XPS_CPUS);
2750 	cpus_read_unlock();
2751 
2752 	return ret;
2753 }
2754 EXPORT_SYMBOL(netif_set_xps_queue);
2755 
2756 #endif
netdev_unbind_all_sb_channels(struct net_device * dev)2757 static void netdev_unbind_all_sb_channels(struct net_device *dev)
2758 {
2759 	struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2760 
2761 	/* Unbind any subordinate channels */
2762 	while (txq-- != &dev->_tx[0]) {
2763 		if (txq->sb_dev)
2764 			netdev_unbind_sb_channel(dev, txq->sb_dev);
2765 	}
2766 }
2767 
netdev_reset_tc(struct net_device * dev)2768 void netdev_reset_tc(struct net_device *dev)
2769 {
2770 #ifdef CONFIG_XPS
2771 	netif_reset_xps_queues_gt(dev, 0);
2772 #endif
2773 	netdev_unbind_all_sb_channels(dev);
2774 
2775 	/* Reset TC configuration of device */
2776 	dev->num_tc = 0;
2777 	memset(dev->tc_to_txq, 0, sizeof(dev->tc_to_txq));
2778 	memset(dev->prio_tc_map, 0, sizeof(dev->prio_tc_map));
2779 }
2780 EXPORT_SYMBOL(netdev_reset_tc);
2781 
netdev_set_tc_queue(struct net_device * dev,u8 tc,u16 count,u16 offset)2782 int netdev_set_tc_queue(struct net_device *dev, u8 tc, u16 count, u16 offset)
2783 {
2784 	if (tc >= dev->num_tc)
2785 		return -EINVAL;
2786 
2787 #ifdef CONFIG_XPS
2788 	netif_reset_xps_queues(dev, offset, count);
2789 #endif
2790 	dev->tc_to_txq[tc].count = count;
2791 	dev->tc_to_txq[tc].offset = offset;
2792 	return 0;
2793 }
2794 EXPORT_SYMBOL(netdev_set_tc_queue);
2795 
netdev_set_num_tc(struct net_device * dev,u8 num_tc)2796 int netdev_set_num_tc(struct net_device *dev, u8 num_tc)
2797 {
2798 	if (num_tc > TC_MAX_QUEUE)
2799 		return -EINVAL;
2800 
2801 #ifdef CONFIG_XPS
2802 	netif_reset_xps_queues_gt(dev, 0);
2803 #endif
2804 	netdev_unbind_all_sb_channels(dev);
2805 
2806 	dev->num_tc = num_tc;
2807 	return 0;
2808 }
2809 EXPORT_SYMBOL(netdev_set_num_tc);
2810 
netdev_unbind_sb_channel(struct net_device * dev,struct net_device * sb_dev)2811 void netdev_unbind_sb_channel(struct net_device *dev,
2812 			      struct net_device *sb_dev)
2813 {
2814 	struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2815 
2816 #ifdef CONFIG_XPS
2817 	netif_reset_xps_queues_gt(sb_dev, 0);
2818 #endif
2819 	memset(sb_dev->tc_to_txq, 0, sizeof(sb_dev->tc_to_txq));
2820 	memset(sb_dev->prio_tc_map, 0, sizeof(sb_dev->prio_tc_map));
2821 
2822 	while (txq-- != &dev->_tx[0]) {
2823 		if (txq->sb_dev == sb_dev)
2824 			txq->sb_dev = NULL;
2825 	}
2826 }
2827 EXPORT_SYMBOL(netdev_unbind_sb_channel);
2828 
netdev_bind_sb_channel_queue(struct net_device * dev,struct net_device * sb_dev,u8 tc,u16 count,u16 offset)2829 int netdev_bind_sb_channel_queue(struct net_device *dev,
2830 				 struct net_device *sb_dev,
2831 				 u8 tc, u16 count, u16 offset)
2832 {
2833 	/* Make certain the sb_dev and dev are already configured */
2834 	if (sb_dev->num_tc >= 0 || tc >= dev->num_tc)
2835 		return -EINVAL;
2836 
2837 	/* We cannot hand out queues we don't have */
2838 	if ((offset + count) > dev->real_num_tx_queues)
2839 		return -EINVAL;
2840 
2841 	/* Record the mapping */
2842 	sb_dev->tc_to_txq[tc].count = count;
2843 	sb_dev->tc_to_txq[tc].offset = offset;
2844 
2845 	/* Provide a way for Tx queue to find the tc_to_txq map or
2846 	 * XPS map for itself.
2847 	 */
2848 	while (count--)
2849 		netdev_get_tx_queue(dev, count + offset)->sb_dev = sb_dev;
2850 
2851 	return 0;
2852 }
2853 EXPORT_SYMBOL(netdev_bind_sb_channel_queue);
2854 
netdev_set_sb_channel(struct net_device * dev,u16 channel)2855 int netdev_set_sb_channel(struct net_device *dev, u16 channel)
2856 {
2857 	/* Do not use a multiqueue device to represent a subordinate channel */
2858 	if (netif_is_multiqueue(dev))
2859 		return -ENODEV;
2860 
2861 	/* We allow channels 1 - 32767 to be used for subordinate channels.
2862 	 * Channel 0 is meant to be "native" mode and used only to represent
2863 	 * the main root device. We allow writing 0 to reset the device back
2864 	 * to normal mode after being used as a subordinate channel.
2865 	 */
2866 	if (channel > S16_MAX)
2867 		return -EINVAL;
2868 
2869 	dev->num_tc = -channel;
2870 
2871 	return 0;
2872 }
2873 EXPORT_SYMBOL(netdev_set_sb_channel);
2874 
2875 /*
2876  * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
2877  * greater than real_num_tx_queues stale skbs on the qdisc must be flushed.
2878  */
netif_set_real_num_tx_queues(struct net_device * dev,unsigned int txq)2879 int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
2880 {
2881 	bool disabling;
2882 	int rc;
2883 
2884 	disabling = txq < dev->real_num_tx_queues;
2885 
2886 	if (txq < 1 || txq > dev->num_tx_queues)
2887 		return -EINVAL;
2888 
2889 	if (dev->reg_state == NETREG_REGISTERED ||
2890 	    dev->reg_state == NETREG_UNREGISTERING) {
2891 		ASSERT_RTNL();
2892 
2893 		rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
2894 						  txq);
2895 		if (rc)
2896 			return rc;
2897 
2898 		if (dev->num_tc)
2899 			netif_setup_tc(dev, txq);
2900 
2901 		dev_qdisc_change_real_num_tx(dev, txq);
2902 
2903 		dev->real_num_tx_queues = txq;
2904 
2905 		if (disabling) {
2906 			synchronize_net();
2907 			qdisc_reset_all_tx_gt(dev, txq);
2908 #ifdef CONFIG_XPS
2909 			netif_reset_xps_queues_gt(dev, txq);
2910 #endif
2911 		}
2912 	} else {
2913 		dev->real_num_tx_queues = txq;
2914 	}
2915 
2916 	return 0;
2917 }
2918 EXPORT_SYMBOL(netif_set_real_num_tx_queues);
2919 
2920 #ifdef CONFIG_SYSFS
2921 /**
2922  *	netif_set_real_num_rx_queues - set actual number of RX queues used
2923  *	@dev: Network device
2924  *	@rxq: Actual number of RX queues
2925  *
2926  *	This must be called either with the rtnl_lock held or before
2927  *	registration of the net device.  Returns 0 on success, or a
2928  *	negative error code.  If called before registration, it always
2929  *	succeeds.
2930  */
netif_set_real_num_rx_queues(struct net_device * dev,unsigned int rxq)2931 int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
2932 {
2933 	int rc;
2934 
2935 	if (rxq < 1 || rxq > dev->num_rx_queues)
2936 		return -EINVAL;
2937 
2938 	if (dev->reg_state == NETREG_REGISTERED) {
2939 		ASSERT_RTNL();
2940 
2941 		rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
2942 						  rxq);
2943 		if (rc)
2944 			return rc;
2945 	}
2946 
2947 	dev->real_num_rx_queues = rxq;
2948 	return 0;
2949 }
2950 EXPORT_SYMBOL(netif_set_real_num_rx_queues);
2951 #endif
2952 
2953 /**
2954  *	netif_set_real_num_queues - set actual number of RX and TX queues used
2955  *	@dev: Network device
2956  *	@txq: Actual number of TX queues
2957  *	@rxq: Actual number of RX queues
2958  *
2959  *	Set the real number of both TX and RX queues.
2960  *	Does nothing if the number of queues is already correct.
2961  */
netif_set_real_num_queues(struct net_device * dev,unsigned int txq,unsigned int rxq)2962 int netif_set_real_num_queues(struct net_device *dev,
2963 			      unsigned int txq, unsigned int rxq)
2964 {
2965 	unsigned int old_rxq = dev->real_num_rx_queues;
2966 	int err;
2967 
2968 	if (txq < 1 || txq > dev->num_tx_queues ||
2969 	    rxq < 1 || rxq > dev->num_rx_queues)
2970 		return -EINVAL;
2971 
2972 	/* Start from increases, so the error path only does decreases -
2973 	 * decreases can't fail.
2974 	 */
2975 	if (rxq > dev->real_num_rx_queues) {
2976 		err = netif_set_real_num_rx_queues(dev, rxq);
2977 		if (err)
2978 			return err;
2979 	}
2980 	if (txq > dev->real_num_tx_queues) {
2981 		err = netif_set_real_num_tx_queues(dev, txq);
2982 		if (err)
2983 			goto undo_rx;
2984 	}
2985 	if (rxq < dev->real_num_rx_queues)
2986 		WARN_ON(netif_set_real_num_rx_queues(dev, rxq));
2987 	if (txq < dev->real_num_tx_queues)
2988 		WARN_ON(netif_set_real_num_tx_queues(dev, txq));
2989 
2990 	return 0;
2991 undo_rx:
2992 	WARN_ON(netif_set_real_num_rx_queues(dev, old_rxq));
2993 	return err;
2994 }
2995 EXPORT_SYMBOL(netif_set_real_num_queues);
2996 
2997 /**
2998  * netif_set_tso_max_size() - set the max size of TSO frames supported
2999  * @dev:	netdev to update
3000  * @size:	max skb->len of a TSO frame
3001  *
3002  * Set the limit on the size of TSO super-frames the device can handle.
3003  * Unless explicitly set the stack will assume the value of
3004  * %GSO_LEGACY_MAX_SIZE.
3005  */
netif_set_tso_max_size(struct net_device * dev,unsigned int size)3006 void netif_set_tso_max_size(struct net_device *dev, unsigned int size)
3007 {
3008 	dev->tso_max_size = min(GSO_MAX_SIZE, size);
3009 	if (size < READ_ONCE(dev->gso_max_size))
3010 		netif_set_gso_max_size(dev, size);
3011 }
3012 EXPORT_SYMBOL(netif_set_tso_max_size);
3013 
3014 /**
3015  * netif_set_tso_max_segs() - set the max number of segs supported for TSO
3016  * @dev:	netdev to update
3017  * @segs:	max number of TCP segments
3018  *
3019  * Set the limit on the number of TCP segments the device can generate from
3020  * a single TSO super-frame.
3021  * Unless explicitly set the stack will assume the value of %GSO_MAX_SEGS.
3022  */
netif_set_tso_max_segs(struct net_device * dev,unsigned int segs)3023 void netif_set_tso_max_segs(struct net_device *dev, unsigned int segs)
3024 {
3025 	dev->tso_max_segs = segs;
3026 	if (segs < READ_ONCE(dev->gso_max_segs))
3027 		netif_set_gso_max_segs(dev, segs);
3028 }
3029 EXPORT_SYMBOL(netif_set_tso_max_segs);
3030 
3031 /**
3032  * netif_inherit_tso_max() - copy all TSO limits from a lower device to an upper
3033  * @to:		netdev to update
3034  * @from:	netdev from which to copy the limits
3035  */
netif_inherit_tso_max(struct net_device * to,const struct net_device * from)3036 void netif_inherit_tso_max(struct net_device *to, const struct net_device *from)
3037 {
3038 	netif_set_tso_max_size(to, from->tso_max_size);
3039 	netif_set_tso_max_segs(to, from->tso_max_segs);
3040 }
3041 EXPORT_SYMBOL(netif_inherit_tso_max);
3042 
3043 /**
3044  * netif_get_num_default_rss_queues - default number of RSS queues
3045  *
3046  * Default value is the number of physical cores if there are only 1 or 2, or
3047  * divided by 2 if there are more.
3048  */
netif_get_num_default_rss_queues(void)3049 int netif_get_num_default_rss_queues(void)
3050 {
3051 	cpumask_var_t cpus;
3052 	int cpu, count = 0;
3053 
3054 	if (unlikely(is_kdump_kernel() || !zalloc_cpumask_var(&cpus, GFP_KERNEL)))
3055 		return 1;
3056 
3057 	cpumask_copy(cpus, cpu_online_mask);
3058 	for_each_cpu(cpu, cpus) {
3059 		++count;
3060 		cpumask_andnot(cpus, cpus, topology_sibling_cpumask(cpu));
3061 	}
3062 	free_cpumask_var(cpus);
3063 
3064 	return count > 2 ? DIV_ROUND_UP(count, 2) : count;
3065 }
3066 EXPORT_SYMBOL(netif_get_num_default_rss_queues);
3067 
__netif_reschedule(struct Qdisc * q)3068 static void __netif_reschedule(struct Qdisc *q)
3069 {
3070 	struct softnet_data *sd;
3071 	unsigned long flags;
3072 
3073 	local_irq_save(flags);
3074 	sd = this_cpu_ptr(&softnet_data);
3075 	q->next_sched = NULL;
3076 	*sd->output_queue_tailp = q;
3077 	sd->output_queue_tailp = &q->next_sched;
3078 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
3079 	local_irq_restore(flags);
3080 }
3081 
__netif_schedule(struct Qdisc * q)3082 void __netif_schedule(struct Qdisc *q)
3083 {
3084 	if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
3085 		__netif_reschedule(q);
3086 }
3087 EXPORT_SYMBOL(__netif_schedule);
3088 
3089 struct dev_kfree_skb_cb {
3090 	enum skb_free_reason reason;
3091 };
3092 
get_kfree_skb_cb(const struct sk_buff * skb)3093 static struct dev_kfree_skb_cb *get_kfree_skb_cb(const struct sk_buff *skb)
3094 {
3095 	return (struct dev_kfree_skb_cb *)skb->cb;
3096 }
3097 
netif_schedule_queue(struct netdev_queue * txq)3098 void netif_schedule_queue(struct netdev_queue *txq)
3099 {
3100 	rcu_read_lock();
3101 	if (!netif_xmit_stopped(txq)) {
3102 		struct Qdisc *q = rcu_dereference(txq->qdisc);
3103 
3104 		__netif_schedule(q);
3105 	}
3106 	rcu_read_unlock();
3107 }
3108 EXPORT_SYMBOL(netif_schedule_queue);
3109 
netif_tx_wake_queue(struct netdev_queue * dev_queue)3110 void netif_tx_wake_queue(struct netdev_queue *dev_queue)
3111 {
3112 	if (test_and_clear_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state)) {
3113 		struct Qdisc *q;
3114 
3115 		rcu_read_lock();
3116 		q = rcu_dereference(dev_queue->qdisc);
3117 		__netif_schedule(q);
3118 		rcu_read_unlock();
3119 	}
3120 }
3121 EXPORT_SYMBOL(netif_tx_wake_queue);
3122 
__dev_kfree_skb_irq(struct sk_buff * skb,enum skb_free_reason reason)3123 void __dev_kfree_skb_irq(struct sk_buff *skb, enum skb_free_reason reason)
3124 {
3125 	unsigned long flags;
3126 
3127 	if (unlikely(!skb))
3128 		return;
3129 
3130 	if (likely(refcount_read(&skb->users) == 1)) {
3131 		smp_rmb();
3132 		refcount_set(&skb->users, 0);
3133 	} else if (likely(!refcount_dec_and_test(&skb->users))) {
3134 		return;
3135 	}
3136 	get_kfree_skb_cb(skb)->reason = reason;
3137 	local_irq_save(flags);
3138 	skb->next = __this_cpu_read(softnet_data.completion_queue);
3139 	__this_cpu_write(softnet_data.completion_queue, skb);
3140 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
3141 	local_irq_restore(flags);
3142 }
3143 EXPORT_SYMBOL(__dev_kfree_skb_irq);
3144 
__dev_kfree_skb_any(struct sk_buff * skb,enum skb_free_reason reason)3145 void __dev_kfree_skb_any(struct sk_buff *skb, enum skb_free_reason reason)
3146 {
3147 	if (in_hardirq() || irqs_disabled())
3148 		__dev_kfree_skb_irq(skb, reason);
3149 	else
3150 		dev_kfree_skb(skb);
3151 }
3152 EXPORT_SYMBOL(__dev_kfree_skb_any);
3153 
3154 
3155 /**
3156  * netif_device_detach - mark device as removed
3157  * @dev: network device
3158  *
3159  * Mark device as removed from system and therefore no longer available.
3160  */
netif_device_detach(struct net_device * dev)3161 void netif_device_detach(struct net_device *dev)
3162 {
3163 	if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
3164 	    netif_running(dev)) {
3165 		netif_tx_stop_all_queues(dev);
3166 	}
3167 }
3168 EXPORT_SYMBOL(netif_device_detach);
3169 
3170 /**
3171  * netif_device_attach - mark device as attached
3172  * @dev: network device
3173  *
3174  * Mark device as attached from system and restart if needed.
3175  */
netif_device_attach(struct net_device * dev)3176 void netif_device_attach(struct net_device *dev)
3177 {
3178 	if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
3179 	    netif_running(dev)) {
3180 		netif_tx_wake_all_queues(dev);
3181 		__netdev_watchdog_up(dev);
3182 	}
3183 }
3184 EXPORT_SYMBOL(netif_device_attach);
3185 
3186 /*
3187  * Returns a Tx hash based on the given packet descriptor a Tx queues' number
3188  * to be used as a distribution range.
3189  */
skb_tx_hash(const struct net_device * dev,const struct net_device * sb_dev,struct sk_buff * skb)3190 static u16 skb_tx_hash(const struct net_device *dev,
3191 		       const struct net_device *sb_dev,
3192 		       struct sk_buff *skb)
3193 {
3194 	u32 hash;
3195 	u16 qoffset = 0;
3196 	u16 qcount = dev->real_num_tx_queues;
3197 
3198 	if (dev->num_tc) {
3199 		u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
3200 
3201 		qoffset = sb_dev->tc_to_txq[tc].offset;
3202 		qcount = sb_dev->tc_to_txq[tc].count;
3203 		if (unlikely(!qcount)) {
3204 			net_warn_ratelimited("%s: invalid qcount, qoffset %u for tc %u\n",
3205 					     sb_dev->name, qoffset, tc);
3206 			qoffset = 0;
3207 			qcount = dev->real_num_tx_queues;
3208 		}
3209 	}
3210 
3211 	if (skb_rx_queue_recorded(skb)) {
3212 		hash = skb_get_rx_queue(skb);
3213 		if (hash >= qoffset)
3214 			hash -= qoffset;
3215 		while (unlikely(hash >= qcount))
3216 			hash -= qcount;
3217 		return hash + qoffset;
3218 	}
3219 
3220 	return (u16) reciprocal_scale(skb_get_hash(skb), qcount) + qoffset;
3221 }
3222 
skb_warn_bad_offload(const struct sk_buff * skb)3223 static void skb_warn_bad_offload(const struct sk_buff *skb)
3224 {
3225 	static const netdev_features_t null_features;
3226 	struct net_device *dev = skb->dev;
3227 	const char *name = "";
3228 
3229 	if (!net_ratelimit())
3230 		return;
3231 
3232 	if (dev) {
3233 		if (dev->dev.parent)
3234 			name = dev_driver_string(dev->dev.parent);
3235 		else
3236 			name = netdev_name(dev);
3237 	}
3238 	skb_dump(KERN_WARNING, skb, false);
3239 	WARN(1, "%s: caps=(%pNF, %pNF)\n",
3240 	     name, dev ? &dev->features : &null_features,
3241 	     skb->sk ? &skb->sk->sk_route_caps : &null_features);
3242 }
3243 
3244 /*
3245  * Invalidate hardware checksum when packet is to be mangled, and
3246  * complete checksum manually on outgoing path.
3247  */
skb_checksum_help(struct sk_buff * skb)3248 int skb_checksum_help(struct sk_buff *skb)
3249 {
3250 	__wsum csum;
3251 	int ret = 0, offset;
3252 
3253 	if (skb->ip_summed == CHECKSUM_COMPLETE)
3254 		goto out_set_summed;
3255 
3256 	if (unlikely(skb_is_gso(skb))) {
3257 		skb_warn_bad_offload(skb);
3258 		return -EINVAL;
3259 	}
3260 
3261 	/* Before computing a checksum, we should make sure no frag could
3262 	 * be modified by an external entity : checksum could be wrong.
3263 	 */
3264 	if (skb_has_shared_frag(skb)) {
3265 		ret = __skb_linearize(skb);
3266 		if (ret)
3267 			goto out;
3268 	}
3269 
3270 	offset = skb_checksum_start_offset(skb);
3271 	ret = -EINVAL;
3272 	if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
3273 		DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
3274 		goto out;
3275 	}
3276 	csum = skb_checksum(skb, offset, skb->len - offset, 0);
3277 
3278 	offset += skb->csum_offset;
3279 	if (WARN_ON_ONCE(offset + sizeof(__sum16) > skb_headlen(skb))) {
3280 		DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
3281 		goto out;
3282 	}
3283 	ret = skb_ensure_writable(skb, offset + sizeof(__sum16));
3284 	if (ret)
3285 		goto out;
3286 
3287 	*(__sum16 *)(skb->data + offset) = csum_fold(csum) ?: CSUM_MANGLED_0;
3288 out_set_summed:
3289 	skb->ip_summed = CHECKSUM_NONE;
3290 out:
3291 	return ret;
3292 }
3293 EXPORT_SYMBOL(skb_checksum_help);
3294 
skb_crc32c_csum_help(struct sk_buff * skb)3295 int skb_crc32c_csum_help(struct sk_buff *skb)
3296 {
3297 	__le32 crc32c_csum;
3298 	int ret = 0, offset, start;
3299 
3300 	if (skb->ip_summed != CHECKSUM_PARTIAL)
3301 		goto out;
3302 
3303 	if (unlikely(skb_is_gso(skb)))
3304 		goto out;
3305 
3306 	/* Before computing a checksum, we should make sure no frag could
3307 	 * be modified by an external entity : checksum could be wrong.
3308 	 */
3309 	if (unlikely(skb_has_shared_frag(skb))) {
3310 		ret = __skb_linearize(skb);
3311 		if (ret)
3312 			goto out;
3313 	}
3314 	start = skb_checksum_start_offset(skb);
3315 	offset = start + offsetof(struct sctphdr, checksum);
3316 	if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
3317 		ret = -EINVAL;
3318 		goto out;
3319 	}
3320 
3321 	ret = skb_ensure_writable(skb, offset + sizeof(__le32));
3322 	if (ret)
3323 		goto out;
3324 
3325 	crc32c_csum = cpu_to_le32(~__skb_checksum(skb, start,
3326 						  skb->len - start, ~(__u32)0,
3327 						  crc32c_csum_stub));
3328 	*(__le32 *)(skb->data + offset) = crc32c_csum;
3329 	skb->ip_summed = CHECKSUM_NONE;
3330 	skb->csum_not_inet = 0;
3331 out:
3332 	return ret;
3333 }
3334 
skb_network_protocol(struct sk_buff * skb,int * depth)3335 __be16 skb_network_protocol(struct sk_buff *skb, int *depth)
3336 {
3337 	__be16 type = skb->protocol;
3338 
3339 	/* Tunnel gso handlers can set protocol to ethernet. */
3340 	if (type == htons(ETH_P_TEB)) {
3341 		struct ethhdr *eth;
3342 
3343 		if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
3344 			return 0;
3345 
3346 		eth = (struct ethhdr *)skb->data;
3347 		type = eth->h_proto;
3348 	}
3349 
3350 	return __vlan_get_protocol(skb, type, depth);
3351 }
3352 
3353 /* openvswitch calls this on rx path, so we need a different check.
3354  */
skb_needs_check(struct sk_buff * skb,bool tx_path)3355 static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path)
3356 {
3357 	if (tx_path)
3358 		return skb->ip_summed != CHECKSUM_PARTIAL &&
3359 		       skb->ip_summed != CHECKSUM_UNNECESSARY;
3360 
3361 	return skb->ip_summed == CHECKSUM_NONE;
3362 }
3363 
3364 /**
3365  *	__skb_gso_segment - Perform segmentation on skb.
3366  *	@skb: buffer to segment
3367  *	@features: features for the output path (see dev->features)
3368  *	@tx_path: whether it is called in TX path
3369  *
3370  *	This function segments the given skb and returns a list of segments.
3371  *
3372  *	It may return NULL if the skb requires no segmentation.  This is
3373  *	only possible when GSO is used for verifying header integrity.
3374  *
3375  *	Segmentation preserves SKB_GSO_CB_OFFSET bytes of previous skb cb.
3376  */
__skb_gso_segment(struct sk_buff * skb,netdev_features_t features,bool tx_path)3377 struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
3378 				  netdev_features_t features, bool tx_path)
3379 {
3380 	struct sk_buff *segs;
3381 
3382 	if (unlikely(skb_needs_check(skb, tx_path))) {
3383 		int err;
3384 
3385 		/* We're going to init ->check field in TCP or UDP header */
3386 		err = skb_cow_head(skb, 0);
3387 		if (err < 0)
3388 			return ERR_PTR(err);
3389 	}
3390 
3391 	/* Only report GSO partial support if it will enable us to
3392 	 * support segmentation on this frame without needing additional
3393 	 * work.
3394 	 */
3395 	if (features & NETIF_F_GSO_PARTIAL) {
3396 		netdev_features_t partial_features = NETIF_F_GSO_ROBUST;
3397 		struct net_device *dev = skb->dev;
3398 
3399 		partial_features |= dev->features & dev->gso_partial_features;
3400 		if (!skb_gso_ok(skb, features | partial_features))
3401 			features &= ~NETIF_F_GSO_PARTIAL;
3402 	}
3403 
3404 	BUILD_BUG_ON(SKB_GSO_CB_OFFSET +
3405 		     sizeof(*SKB_GSO_CB(skb)) > sizeof(skb->cb));
3406 
3407 	SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb);
3408 	SKB_GSO_CB(skb)->encap_level = 0;
3409 
3410 	skb_reset_mac_header(skb);
3411 	skb_reset_mac_len(skb);
3412 
3413 	segs = skb_mac_gso_segment(skb, features);
3414 
3415 	if (segs != skb && unlikely(skb_needs_check(skb, tx_path) && !IS_ERR(segs)))
3416 		skb_warn_bad_offload(skb);
3417 
3418 	return segs;
3419 }
3420 EXPORT_SYMBOL(__skb_gso_segment);
3421 
3422 /* Take action when hardware reception checksum errors are detected. */
3423 #ifdef CONFIG_BUG
do_netdev_rx_csum_fault(struct net_device * dev,struct sk_buff * skb)3424 static void do_netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3425 {
3426 	netdev_err(dev, "hw csum failure\n");
3427 	skb_dump(KERN_ERR, skb, true);
3428 	dump_stack();
3429 }
3430 
netdev_rx_csum_fault(struct net_device * dev,struct sk_buff * skb)3431 void netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3432 {
3433 	DO_ONCE_LITE(do_netdev_rx_csum_fault, dev, skb);
3434 }
3435 EXPORT_SYMBOL(netdev_rx_csum_fault);
3436 #endif
3437 
3438 /* XXX: check that highmem exists at all on the given machine. */
illegal_highdma(struct net_device * dev,struct sk_buff * skb)3439 static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
3440 {
3441 #ifdef CONFIG_HIGHMEM
3442 	int i;
3443 
3444 	if (!(dev->features & NETIF_F_HIGHDMA)) {
3445 		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
3446 			skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
3447 
3448 			if (PageHighMem(skb_frag_page(frag)))
3449 				return 1;
3450 		}
3451 	}
3452 #endif
3453 	return 0;
3454 }
3455 
3456 /* If MPLS offload request, verify we are testing hardware MPLS features
3457  * instead of standard features for the netdev.
3458  */
3459 #if IS_ENABLED(CONFIG_NET_MPLS_GSO)
net_mpls_features(struct sk_buff * skb,netdev_features_t features,__be16 type)3460 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3461 					   netdev_features_t features,
3462 					   __be16 type)
3463 {
3464 	if (eth_p_mpls(type))
3465 		features &= skb->dev->mpls_features;
3466 
3467 	return features;
3468 }
3469 #else
net_mpls_features(struct sk_buff * skb,netdev_features_t features,__be16 type)3470 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3471 					   netdev_features_t features,
3472 					   __be16 type)
3473 {
3474 	return features;
3475 }
3476 #endif
3477 
harmonize_features(struct sk_buff * skb,netdev_features_t features)3478 static netdev_features_t harmonize_features(struct sk_buff *skb,
3479 	netdev_features_t features)
3480 {
3481 	__be16 type;
3482 
3483 	type = skb_network_protocol(skb, NULL);
3484 	features = net_mpls_features(skb, features, type);
3485 
3486 	if (skb->ip_summed != CHECKSUM_NONE &&
3487 	    !can_checksum_protocol(features, type)) {
3488 		features &= ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
3489 	}
3490 	if (illegal_highdma(skb->dev, skb))
3491 		features &= ~NETIF_F_SG;
3492 
3493 	return features;
3494 }
3495 
passthru_features_check(struct sk_buff * skb,struct net_device * dev,netdev_features_t features)3496 netdev_features_t passthru_features_check(struct sk_buff *skb,
3497 					  struct net_device *dev,
3498 					  netdev_features_t features)
3499 {
3500 	return features;
3501 }
3502 EXPORT_SYMBOL(passthru_features_check);
3503 
dflt_features_check(struct sk_buff * skb,struct net_device * dev,netdev_features_t features)3504 static netdev_features_t dflt_features_check(struct sk_buff *skb,
3505 					     struct net_device *dev,
3506 					     netdev_features_t features)
3507 {
3508 	return vlan_features_check(skb, features);
3509 }
3510 
gso_features_check(const struct sk_buff * skb,struct net_device * dev,netdev_features_t features)3511 static netdev_features_t gso_features_check(const struct sk_buff *skb,
3512 					    struct net_device *dev,
3513 					    netdev_features_t features)
3514 {
3515 	u16 gso_segs = skb_shinfo(skb)->gso_segs;
3516 
3517 	if (gso_segs > READ_ONCE(dev->gso_max_segs))
3518 		return features & ~NETIF_F_GSO_MASK;
3519 
3520 	if (!skb_shinfo(skb)->gso_type) {
3521 		skb_warn_bad_offload(skb);
3522 		return features & ~NETIF_F_GSO_MASK;
3523 	}
3524 
3525 	/* Support for GSO partial features requires software
3526 	 * intervention before we can actually process the packets
3527 	 * so we need to strip support for any partial features now
3528 	 * and we can pull them back in after we have partially
3529 	 * segmented the frame.
3530 	 */
3531 	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL))
3532 		features &= ~dev->gso_partial_features;
3533 
3534 	/* Make sure to clear the IPv4 ID mangling feature if the
3535 	 * IPv4 header has the potential to be fragmented.
3536 	 */
3537 	if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
3538 		struct iphdr *iph = skb->encapsulation ?
3539 				    inner_ip_hdr(skb) : ip_hdr(skb);
3540 
3541 		if (!(iph->frag_off & htons(IP_DF)))
3542 			features &= ~NETIF_F_TSO_MANGLEID;
3543 	}
3544 
3545 	return features;
3546 }
3547 
netif_skb_features(struct sk_buff * skb)3548 netdev_features_t netif_skb_features(struct sk_buff *skb)
3549 {
3550 	struct net_device *dev = skb->dev;
3551 	netdev_features_t features = dev->features;
3552 
3553 	if (skb_is_gso(skb))
3554 		features = gso_features_check(skb, dev, features);
3555 
3556 	/* If encapsulation offload request, verify we are testing
3557 	 * hardware encapsulation features instead of standard
3558 	 * features for the netdev
3559 	 */
3560 	if (skb->encapsulation)
3561 		features &= dev->hw_enc_features;
3562 
3563 	if (skb_vlan_tagged(skb))
3564 		features = netdev_intersect_features(features,
3565 						     dev->vlan_features |
3566 						     NETIF_F_HW_VLAN_CTAG_TX |
3567 						     NETIF_F_HW_VLAN_STAG_TX);
3568 
3569 	if (dev->netdev_ops->ndo_features_check)
3570 		features &= dev->netdev_ops->ndo_features_check(skb, dev,
3571 								features);
3572 	else
3573 		features &= dflt_features_check(skb, dev, features);
3574 
3575 	return harmonize_features(skb, features);
3576 }
3577 EXPORT_SYMBOL(netif_skb_features);
3578 
xmit_one(struct sk_buff * skb,struct net_device * dev,struct netdev_queue * txq,bool more)3579 static int xmit_one(struct sk_buff *skb, struct net_device *dev,
3580 		    struct netdev_queue *txq, bool more)
3581 {
3582 	unsigned int len;
3583 	int rc;
3584 
3585 	if (dev_nit_active(dev))
3586 		dev_queue_xmit_nit(skb, dev);
3587 
3588 	len = skb->len;
3589 	trace_net_dev_start_xmit(skb, dev);
3590 	rc = netdev_start_xmit(skb, dev, txq, more);
3591 	trace_net_dev_xmit(skb, rc, dev, len);
3592 
3593 	return rc;
3594 }
3595 
dev_hard_start_xmit(struct sk_buff * first,struct net_device * dev,struct netdev_queue * txq,int * ret)3596 struct sk_buff *dev_hard_start_xmit(struct sk_buff *first, struct net_device *dev,
3597 				    struct netdev_queue *txq, int *ret)
3598 {
3599 	struct sk_buff *skb = first;
3600 	int rc = NETDEV_TX_OK;
3601 
3602 	while (skb) {
3603 		struct sk_buff *next = skb->next;
3604 
3605 		skb_mark_not_on_list(skb);
3606 		rc = xmit_one(skb, dev, txq, next != NULL);
3607 		if (unlikely(!dev_xmit_complete(rc))) {
3608 			skb->next = next;
3609 			goto out;
3610 		}
3611 
3612 		skb = next;
3613 		if (netif_tx_queue_stopped(txq) && skb) {
3614 			rc = NETDEV_TX_BUSY;
3615 			break;
3616 		}
3617 	}
3618 
3619 out:
3620 	*ret = rc;
3621 	return skb;
3622 }
3623 
validate_xmit_vlan(struct sk_buff * skb,netdev_features_t features)3624 static struct sk_buff *validate_xmit_vlan(struct sk_buff *skb,
3625 					  netdev_features_t features)
3626 {
3627 	if (skb_vlan_tag_present(skb) &&
3628 	    !vlan_hw_offload_capable(features, skb->vlan_proto))
3629 		skb = __vlan_hwaccel_push_inside(skb);
3630 	return skb;
3631 }
3632 
skb_csum_hwoffload_help(struct sk_buff * skb,const netdev_features_t features)3633 int skb_csum_hwoffload_help(struct sk_buff *skb,
3634 			    const netdev_features_t features)
3635 {
3636 	if (unlikely(skb_csum_is_sctp(skb)))
3637 		return !!(features & NETIF_F_SCTP_CRC) ? 0 :
3638 			skb_crc32c_csum_help(skb);
3639 
3640 	if (features & NETIF_F_HW_CSUM)
3641 		return 0;
3642 
3643 	if (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) {
3644 		switch (skb->csum_offset) {
3645 		case offsetof(struct tcphdr, check):
3646 		case offsetof(struct udphdr, check):
3647 			return 0;
3648 		}
3649 	}
3650 
3651 	return skb_checksum_help(skb);
3652 }
3653 EXPORT_SYMBOL(skb_csum_hwoffload_help);
3654 
validate_xmit_skb(struct sk_buff * skb,struct net_device * dev,bool * again)3655 static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device *dev, bool *again)
3656 {
3657 	netdev_features_t features;
3658 
3659 	features = netif_skb_features(skb);
3660 	skb = validate_xmit_vlan(skb, features);
3661 	if (unlikely(!skb))
3662 		goto out_null;
3663 
3664 	skb = sk_validate_xmit_skb(skb, dev);
3665 	if (unlikely(!skb))
3666 		goto out_null;
3667 
3668 	if (netif_needs_gso(skb, features)) {
3669 		struct sk_buff *segs;
3670 
3671 		segs = skb_gso_segment(skb, features);
3672 		if (IS_ERR(segs)) {
3673 			goto out_kfree_skb;
3674 		} else if (segs) {
3675 			consume_skb(skb);
3676 			skb = segs;
3677 		}
3678 	} else {
3679 		if (skb_needs_linearize(skb, features) &&
3680 		    __skb_linearize(skb))
3681 			goto out_kfree_skb;
3682 
3683 		/* If packet is not checksummed and device does not
3684 		 * support checksumming for this protocol, complete
3685 		 * checksumming here.
3686 		 */
3687 		if (skb->ip_summed == CHECKSUM_PARTIAL) {
3688 			if (skb->encapsulation)
3689 				skb_set_inner_transport_header(skb,
3690 							       skb_checksum_start_offset(skb));
3691 			else
3692 				skb_set_transport_header(skb,
3693 							 skb_checksum_start_offset(skb));
3694 			if (skb_csum_hwoffload_help(skb, features))
3695 				goto out_kfree_skb;
3696 		}
3697 	}
3698 
3699 	skb = validate_xmit_xfrm(skb, features, again);
3700 
3701 	return skb;
3702 
3703 out_kfree_skb:
3704 	kfree_skb(skb);
3705 out_null:
3706 	dev_core_stats_tx_dropped_inc(dev);
3707 	return NULL;
3708 }
3709 
validate_xmit_skb_list(struct sk_buff * skb,struct net_device * dev,bool * again)3710 struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *dev, bool *again)
3711 {
3712 	struct sk_buff *next, *head = NULL, *tail;
3713 
3714 	for (; skb != NULL; skb = next) {
3715 		next = skb->next;
3716 		skb_mark_not_on_list(skb);
3717 
3718 		/* in case skb wont be segmented, point to itself */
3719 		skb->prev = skb;
3720 
3721 		skb = validate_xmit_skb(skb, dev, again);
3722 		if (!skb)
3723 			continue;
3724 
3725 		if (!head)
3726 			head = skb;
3727 		else
3728 			tail->next = skb;
3729 		/* If skb was segmented, skb->prev points to
3730 		 * the last segment. If not, it still contains skb.
3731 		 */
3732 		tail = skb->prev;
3733 	}
3734 	return head;
3735 }
3736 EXPORT_SYMBOL_GPL(validate_xmit_skb_list);
3737 
qdisc_pkt_len_init(struct sk_buff * skb)3738 static void qdisc_pkt_len_init(struct sk_buff *skb)
3739 {
3740 	const struct skb_shared_info *shinfo = skb_shinfo(skb);
3741 
3742 	qdisc_skb_cb(skb)->pkt_len = skb->len;
3743 
3744 	/* To get more precise estimation of bytes sent on wire,
3745 	 * we add to pkt_len the headers size of all segments
3746 	 */
3747 	if (shinfo->gso_size && skb_transport_header_was_set(skb)) {
3748 		unsigned int hdr_len;
3749 		u16 gso_segs = shinfo->gso_segs;
3750 
3751 		/* mac layer + network layer */
3752 		hdr_len = skb_transport_header(skb) - skb_mac_header(skb);
3753 
3754 		/* + transport layer */
3755 		if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) {
3756 			const struct tcphdr *th;
3757 			struct tcphdr _tcphdr;
3758 
3759 			th = skb_header_pointer(skb, skb_transport_offset(skb),
3760 						sizeof(_tcphdr), &_tcphdr);
3761 			if (likely(th))
3762 				hdr_len += __tcp_hdrlen(th);
3763 		} else {
3764 			struct udphdr _udphdr;
3765 
3766 			if (skb_header_pointer(skb, skb_transport_offset(skb),
3767 					       sizeof(_udphdr), &_udphdr))
3768 				hdr_len += sizeof(struct udphdr);
3769 		}
3770 
3771 		if (shinfo->gso_type & SKB_GSO_DODGY)
3772 			gso_segs = DIV_ROUND_UP(skb->len - hdr_len,
3773 						shinfo->gso_size);
3774 
3775 		qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len;
3776 	}
3777 }
3778 
dev_qdisc_enqueue(struct sk_buff * skb,struct Qdisc * q,struct sk_buff ** to_free,struct netdev_queue * txq)3779 static int dev_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *q,
3780 			     struct sk_buff **to_free,
3781 			     struct netdev_queue *txq)
3782 {
3783 	int rc;
3784 
3785 	rc = q->enqueue(skb, q, to_free) & NET_XMIT_MASK;
3786 	if (rc == NET_XMIT_SUCCESS)
3787 		trace_qdisc_enqueue(q, txq, skb);
3788 	return rc;
3789 }
3790 
__dev_xmit_skb(struct sk_buff * skb,struct Qdisc * q,struct net_device * dev,struct netdev_queue * txq)3791 static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
3792 				 struct net_device *dev,
3793 				 struct netdev_queue *txq)
3794 {
3795 	spinlock_t *root_lock = qdisc_lock(q);
3796 	struct sk_buff *to_free = NULL;
3797 	bool contended;
3798 	int rc;
3799 
3800 	qdisc_calculate_pkt_len(skb, q);
3801 
3802 	if (q->flags & TCQ_F_NOLOCK) {
3803 		if (q->flags & TCQ_F_CAN_BYPASS && nolock_qdisc_is_empty(q) &&
3804 		    qdisc_run_begin(q)) {
3805 			/* Retest nolock_qdisc_is_empty() within the protection
3806 			 * of q->seqlock to protect from racing with requeuing.
3807 			 */
3808 			if (unlikely(!nolock_qdisc_is_empty(q))) {
3809 				rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3810 				__qdisc_run(q);
3811 				qdisc_run_end(q);
3812 
3813 				goto no_lock_out;
3814 			}
3815 
3816 			qdisc_bstats_cpu_update(q, skb);
3817 			if (sch_direct_xmit(skb, q, dev, txq, NULL, true) &&
3818 			    !nolock_qdisc_is_empty(q))
3819 				__qdisc_run(q);
3820 
3821 			qdisc_run_end(q);
3822 			return NET_XMIT_SUCCESS;
3823 		}
3824 
3825 		rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3826 		qdisc_run(q);
3827 
3828 no_lock_out:
3829 		if (unlikely(to_free))
3830 			kfree_skb_list_reason(to_free,
3831 					      SKB_DROP_REASON_QDISC_DROP);
3832 		return rc;
3833 	}
3834 
3835 	/*
3836 	 * Heuristic to force contended enqueues to serialize on a
3837 	 * separate lock before trying to get qdisc main lock.
3838 	 * This permits qdisc->running owner to get the lock more
3839 	 * often and dequeue packets faster.
3840 	 * On PREEMPT_RT it is possible to preempt the qdisc owner during xmit
3841 	 * and then other tasks will only enqueue packets. The packets will be
3842 	 * sent after the qdisc owner is scheduled again. To prevent this
3843 	 * scenario the task always serialize on the lock.
3844 	 */
3845 	contended = qdisc_is_running(q) || IS_ENABLED(CONFIG_PREEMPT_RT);
3846 	if (unlikely(contended))
3847 		spin_lock(&q->busylock);
3848 
3849 	spin_lock(root_lock);
3850 	if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
3851 		__qdisc_drop(skb, &to_free);
3852 		rc = NET_XMIT_DROP;
3853 	} else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
3854 		   qdisc_run_begin(q)) {
3855 		/*
3856 		 * This is a work-conserving queue; there are no old skbs
3857 		 * waiting to be sent out; and the qdisc is not running -
3858 		 * xmit the skb directly.
3859 		 */
3860 
3861 		qdisc_bstats_update(q, skb);
3862 
3863 		if (sch_direct_xmit(skb, q, dev, txq, root_lock, true)) {
3864 			if (unlikely(contended)) {
3865 				spin_unlock(&q->busylock);
3866 				contended = false;
3867 			}
3868 			__qdisc_run(q);
3869 		}
3870 
3871 		qdisc_run_end(q);
3872 		rc = NET_XMIT_SUCCESS;
3873 	} else {
3874 		rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3875 		if (qdisc_run_begin(q)) {
3876 			if (unlikely(contended)) {
3877 				spin_unlock(&q->busylock);
3878 				contended = false;
3879 			}
3880 			__qdisc_run(q);
3881 			qdisc_run_end(q);
3882 		}
3883 	}
3884 	spin_unlock(root_lock);
3885 	if (unlikely(to_free))
3886 		kfree_skb_list_reason(to_free, SKB_DROP_REASON_QDISC_DROP);
3887 	if (unlikely(contended))
3888 		spin_unlock(&q->busylock);
3889 	return rc;
3890 }
3891 
3892 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
skb_update_prio(struct sk_buff * skb)3893 static void skb_update_prio(struct sk_buff *skb)
3894 {
3895 	const struct netprio_map *map;
3896 	const struct sock *sk;
3897 	unsigned int prioidx;
3898 
3899 	if (skb->priority)
3900 		return;
3901 	map = rcu_dereference_bh(skb->dev->priomap);
3902 	if (!map)
3903 		return;
3904 	sk = skb_to_full_sk(skb);
3905 	if (!sk)
3906 		return;
3907 
3908 	prioidx = sock_cgroup_prioidx(&sk->sk_cgrp_data);
3909 
3910 	if (prioidx < map->priomap_len)
3911 		skb->priority = map->priomap[prioidx];
3912 }
3913 #else
3914 #define skb_update_prio(skb)
3915 #endif
3916 
3917 /**
3918  *	dev_loopback_xmit - loop back @skb
3919  *	@net: network namespace this loopback is happening in
3920  *	@sk:  sk needed to be a netfilter okfn
3921  *	@skb: buffer to transmit
3922  */
dev_loopback_xmit(struct net * net,struct sock * sk,struct sk_buff * skb)3923 int dev_loopback_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
3924 {
3925 	skb_reset_mac_header(skb);
3926 	__skb_pull(skb, skb_network_offset(skb));
3927 	skb->pkt_type = PACKET_LOOPBACK;
3928 	if (skb->ip_summed == CHECKSUM_NONE)
3929 		skb->ip_summed = CHECKSUM_UNNECESSARY;
3930 	DEBUG_NET_WARN_ON_ONCE(!skb_dst(skb));
3931 	skb_dst_force(skb);
3932 	netif_rx(skb);
3933 	return 0;
3934 }
3935 EXPORT_SYMBOL(dev_loopback_xmit);
3936 
3937 #ifdef CONFIG_NET_EGRESS
3938 static struct sk_buff *
sch_handle_egress(struct sk_buff * skb,int * ret,struct net_device * dev)3939 sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
3940 {
3941 #ifdef CONFIG_NET_CLS_ACT
3942 	struct mini_Qdisc *miniq = rcu_dereference_bh(dev->miniq_egress);
3943 	struct tcf_result cl_res;
3944 
3945 	if (!miniq)
3946 		return skb;
3947 
3948 	/* qdisc_skb_cb(skb)->pkt_len was already set by the caller. */
3949 	tc_skb_cb(skb)->mru = 0;
3950 	tc_skb_cb(skb)->post_ct = false;
3951 	mini_qdisc_bstats_cpu_update(miniq, skb);
3952 
3953 	switch (tcf_classify(skb, miniq->block, miniq->filter_list, &cl_res, false)) {
3954 	case TC_ACT_OK:
3955 	case TC_ACT_RECLASSIFY:
3956 		skb->tc_index = TC_H_MIN(cl_res.classid);
3957 		break;
3958 	case TC_ACT_SHOT:
3959 		mini_qdisc_qstats_cpu_drop(miniq);
3960 		*ret = NET_XMIT_DROP;
3961 		kfree_skb_reason(skb, SKB_DROP_REASON_TC_EGRESS);
3962 		return NULL;
3963 	case TC_ACT_STOLEN:
3964 	case TC_ACT_QUEUED:
3965 	case TC_ACT_TRAP:
3966 		*ret = NET_XMIT_SUCCESS;
3967 		consume_skb(skb);
3968 		return NULL;
3969 	case TC_ACT_REDIRECT:
3970 		/* No need to push/pop skb's mac_header here on egress! */
3971 		skb_do_redirect(skb);
3972 		*ret = NET_XMIT_SUCCESS;
3973 		return NULL;
3974 	default:
3975 		break;
3976 	}
3977 #endif /* CONFIG_NET_CLS_ACT */
3978 
3979 	return skb;
3980 }
3981 
3982 static struct netdev_queue *
netdev_tx_queue_mapping(struct net_device * dev,struct sk_buff * skb)3983 netdev_tx_queue_mapping(struct net_device *dev, struct sk_buff *skb)
3984 {
3985 	int qm = skb_get_queue_mapping(skb);
3986 
3987 	return netdev_get_tx_queue(dev, netdev_cap_txqueue(dev, qm));
3988 }
3989 
netdev_xmit_txqueue_skipped(void)3990 static bool netdev_xmit_txqueue_skipped(void)
3991 {
3992 	return __this_cpu_read(softnet_data.xmit.skip_txqueue);
3993 }
3994 
netdev_xmit_skip_txqueue(bool skip)3995 void netdev_xmit_skip_txqueue(bool skip)
3996 {
3997 	__this_cpu_write(softnet_data.xmit.skip_txqueue, skip);
3998 }
3999 EXPORT_SYMBOL_GPL(netdev_xmit_skip_txqueue);
4000 #endif /* CONFIG_NET_EGRESS */
4001 
4002 #ifdef CONFIG_XPS
__get_xps_queue_idx(struct net_device * dev,struct sk_buff * skb,struct xps_dev_maps * dev_maps,unsigned int tci)4003 static int __get_xps_queue_idx(struct net_device *dev, struct sk_buff *skb,
4004 			       struct xps_dev_maps *dev_maps, unsigned int tci)
4005 {
4006 	int tc = netdev_get_prio_tc_map(dev, skb->priority);
4007 	struct xps_map *map;
4008 	int queue_index = -1;
4009 
4010 	if (tc >= dev_maps->num_tc || tci >= dev_maps->nr_ids)
4011 		return queue_index;
4012 
4013 	tci *= dev_maps->num_tc;
4014 	tci += tc;
4015 
4016 	map = rcu_dereference(dev_maps->attr_map[tci]);
4017 	if (map) {
4018 		if (map->len == 1)
4019 			queue_index = map->queues[0];
4020 		else
4021 			queue_index = map->queues[reciprocal_scale(
4022 						skb_get_hash(skb), map->len)];
4023 		if (unlikely(queue_index >= dev->real_num_tx_queues))
4024 			queue_index = -1;
4025 	}
4026 	return queue_index;
4027 }
4028 #endif
4029 
get_xps_queue(struct net_device * dev,struct net_device * sb_dev,struct sk_buff * skb)4030 static int get_xps_queue(struct net_device *dev, struct net_device *sb_dev,
4031 			 struct sk_buff *skb)
4032 {
4033 #ifdef CONFIG_XPS
4034 	struct xps_dev_maps *dev_maps;
4035 	struct sock *sk = skb->sk;
4036 	int queue_index = -1;
4037 
4038 	if (!static_key_false(&xps_needed))
4039 		return -1;
4040 
4041 	rcu_read_lock();
4042 	if (!static_key_false(&xps_rxqs_needed))
4043 		goto get_cpus_map;
4044 
4045 	dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_RXQS]);
4046 	if (dev_maps) {
4047 		int tci = sk_rx_queue_get(sk);
4048 
4049 		if (tci >= 0)
4050 			queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
4051 							  tci);
4052 	}
4053 
4054 get_cpus_map:
4055 	if (queue_index < 0) {
4056 		dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_CPUS]);
4057 		if (dev_maps) {
4058 			unsigned int tci = skb->sender_cpu - 1;
4059 
4060 			queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
4061 							  tci);
4062 		}
4063 	}
4064 	rcu_read_unlock();
4065 
4066 	return queue_index;
4067 #else
4068 	return -1;
4069 #endif
4070 }
4071 
dev_pick_tx_zero(struct net_device * dev,struct sk_buff * skb,struct net_device * sb_dev)4072 u16 dev_pick_tx_zero(struct net_device *dev, struct sk_buff *skb,
4073 		     struct net_device *sb_dev)
4074 {
4075 	return 0;
4076 }
4077 EXPORT_SYMBOL(dev_pick_tx_zero);
4078 
dev_pick_tx_cpu_id(struct net_device * dev,struct sk_buff * skb,struct net_device * sb_dev)4079 u16 dev_pick_tx_cpu_id(struct net_device *dev, struct sk_buff *skb,
4080 		       struct net_device *sb_dev)
4081 {
4082 	return (u16)raw_smp_processor_id() % dev->real_num_tx_queues;
4083 }
4084 EXPORT_SYMBOL(dev_pick_tx_cpu_id);
4085 
netdev_pick_tx(struct net_device * dev,struct sk_buff * skb,struct net_device * sb_dev)4086 u16 netdev_pick_tx(struct net_device *dev, struct sk_buff *skb,
4087 		     struct net_device *sb_dev)
4088 {
4089 	struct sock *sk = skb->sk;
4090 	int queue_index = sk_tx_queue_get(sk);
4091 
4092 	sb_dev = sb_dev ? : dev;
4093 
4094 	if (queue_index < 0 || skb->ooo_okay ||
4095 	    queue_index >= dev->real_num_tx_queues) {
4096 		int new_index = get_xps_queue(dev, sb_dev, skb);
4097 
4098 		if (new_index < 0)
4099 			new_index = skb_tx_hash(dev, sb_dev, skb);
4100 
4101 		if (queue_index != new_index && sk &&
4102 		    sk_fullsock(sk) &&
4103 		    rcu_access_pointer(sk->sk_dst_cache))
4104 			sk_tx_queue_set(sk, new_index);
4105 
4106 		queue_index = new_index;
4107 	}
4108 
4109 	return queue_index;
4110 }
4111 EXPORT_SYMBOL(netdev_pick_tx);
4112 
netdev_core_pick_tx(struct net_device * dev,struct sk_buff * skb,struct net_device * sb_dev)4113 struct netdev_queue *netdev_core_pick_tx(struct net_device *dev,
4114 					 struct sk_buff *skb,
4115 					 struct net_device *sb_dev)
4116 {
4117 	int queue_index = 0;
4118 
4119 #ifdef CONFIG_XPS
4120 	u32 sender_cpu = skb->sender_cpu - 1;
4121 
4122 	if (sender_cpu >= (u32)NR_CPUS)
4123 		skb->sender_cpu = raw_smp_processor_id() + 1;
4124 #endif
4125 
4126 	if (dev->real_num_tx_queues != 1) {
4127 		const struct net_device_ops *ops = dev->netdev_ops;
4128 
4129 		if (ops->ndo_select_queue)
4130 			queue_index = ops->ndo_select_queue(dev, skb, sb_dev);
4131 		else
4132 			queue_index = netdev_pick_tx(dev, skb, sb_dev);
4133 
4134 		queue_index = netdev_cap_txqueue(dev, queue_index);
4135 	}
4136 
4137 	skb_set_queue_mapping(skb, queue_index);
4138 	return netdev_get_tx_queue(dev, queue_index);
4139 }
4140 
4141 /**
4142  * __dev_queue_xmit() - transmit a buffer
4143  * @skb:	buffer to transmit
4144  * @sb_dev:	suboordinate device used for L2 forwarding offload
4145  *
4146  * Queue a buffer for transmission to a network device. The caller must
4147  * have set the device and priority and built the buffer before calling
4148  * this function. The function can be called from an interrupt.
4149  *
4150  * When calling this method, interrupts MUST be enabled. This is because
4151  * the BH enable code must have IRQs enabled so that it will not deadlock.
4152  *
4153  * Regardless of the return value, the skb is consumed, so it is currently
4154  * difficult to retry a send to this method. (You can bump the ref count
4155  * before sending to hold a reference for retry if you are careful.)
4156  *
4157  * Return:
4158  * * 0				- buffer successfully transmitted
4159  * * positive qdisc return code	- NET_XMIT_DROP etc.
4160  * * negative errno		- other errors
4161  */
__dev_queue_xmit(struct sk_buff * skb,struct net_device * sb_dev)4162 int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
4163 {
4164 	struct net_device *dev = skb->dev;
4165 	struct netdev_queue *txq = NULL;
4166 	struct Qdisc *q;
4167 	int rc = -ENOMEM;
4168 	bool again = false;
4169 
4170 	skb_reset_mac_header(skb);
4171 	skb_assert_len(skb);
4172 
4173 	if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP))
4174 		__skb_tstamp_tx(skb, NULL, NULL, skb->sk, SCM_TSTAMP_SCHED);
4175 
4176 	/* Disable soft irqs for various locks below. Also
4177 	 * stops preemption for RCU.
4178 	 */
4179 	rcu_read_lock_bh();
4180 
4181 	skb_update_prio(skb);
4182 
4183 	qdisc_pkt_len_init(skb);
4184 #ifdef CONFIG_NET_CLS_ACT
4185 	skb->tc_at_ingress = 0;
4186 #endif
4187 #ifdef CONFIG_NET_EGRESS
4188 	if (static_branch_unlikely(&egress_needed_key)) {
4189 		if (nf_hook_egress_active()) {
4190 			skb = nf_hook_egress(skb, &rc, dev);
4191 			if (!skb)
4192 				goto out;
4193 		}
4194 
4195 		netdev_xmit_skip_txqueue(false);
4196 
4197 		nf_skip_egress(skb, true);
4198 		skb = sch_handle_egress(skb, &rc, dev);
4199 		if (!skb)
4200 			goto out;
4201 		nf_skip_egress(skb, false);
4202 
4203 		if (netdev_xmit_txqueue_skipped())
4204 			txq = netdev_tx_queue_mapping(dev, skb);
4205 	}
4206 #endif
4207 	/* If device/qdisc don't need skb->dst, release it right now while
4208 	 * its hot in this cpu cache.
4209 	 */
4210 	if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
4211 		skb_dst_drop(skb);
4212 	else
4213 		skb_dst_force(skb);
4214 
4215 	if (!txq)
4216 		txq = netdev_core_pick_tx(dev, skb, sb_dev);
4217 
4218 	q = rcu_dereference_bh(txq->qdisc);
4219 
4220 	trace_net_dev_queue(skb);
4221 	if (q->enqueue) {
4222 		rc = __dev_xmit_skb(skb, q, dev, txq);
4223 		goto out;
4224 	}
4225 
4226 	/* The device has no queue. Common case for software devices:
4227 	 * loopback, all the sorts of tunnels...
4228 
4229 	 * Really, it is unlikely that netif_tx_lock protection is necessary
4230 	 * here.  (f.e. loopback and IP tunnels are clean ignoring statistics
4231 	 * counters.)
4232 	 * However, it is possible, that they rely on protection
4233 	 * made by us here.
4234 
4235 	 * Check this and shot the lock. It is not prone from deadlocks.
4236 	 *Either shot noqueue qdisc, it is even simpler 8)
4237 	 */
4238 	if (dev->flags & IFF_UP) {
4239 		int cpu = smp_processor_id(); /* ok because BHs are off */
4240 
4241 		/* Other cpus might concurrently change txq->xmit_lock_owner
4242 		 * to -1 or to their cpu id, but not to our id.
4243 		 */
4244 		if (READ_ONCE(txq->xmit_lock_owner) != cpu) {
4245 			if (dev_xmit_recursion())
4246 				goto recursion_alert;
4247 
4248 			skb = validate_xmit_skb(skb, dev, &again);
4249 			if (!skb)
4250 				goto out;
4251 
4252 			HARD_TX_LOCK(dev, txq, cpu);
4253 
4254 			if (!netif_xmit_stopped(txq)) {
4255 				dev_xmit_recursion_inc();
4256 				skb = dev_hard_start_xmit(skb, dev, txq, &rc);
4257 				dev_xmit_recursion_dec();
4258 				if (dev_xmit_complete(rc)) {
4259 					HARD_TX_UNLOCK(dev, txq);
4260 					goto out;
4261 				}
4262 			}
4263 			HARD_TX_UNLOCK(dev, txq);
4264 			net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
4265 					     dev->name);
4266 		} else {
4267 			/* Recursion is detected! It is possible,
4268 			 * unfortunately
4269 			 */
4270 recursion_alert:
4271 			net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
4272 					     dev->name);
4273 		}
4274 	}
4275 
4276 	rc = -ENETDOWN;
4277 	rcu_read_unlock_bh();
4278 
4279 	dev_core_stats_tx_dropped_inc(dev);
4280 	kfree_skb_list(skb);
4281 	return rc;
4282 out:
4283 	rcu_read_unlock_bh();
4284 	return rc;
4285 }
4286 EXPORT_SYMBOL(__dev_queue_xmit);
4287 
__dev_direct_xmit(struct sk_buff * skb,u16 queue_id)4288 int __dev_direct_xmit(struct sk_buff *skb, u16 queue_id)
4289 {
4290 	struct net_device *dev = skb->dev;
4291 	struct sk_buff *orig_skb = skb;
4292 	struct netdev_queue *txq;
4293 	int ret = NETDEV_TX_BUSY;
4294 	bool again = false;
4295 
4296 	if (unlikely(!netif_running(dev) ||
4297 		     !netif_carrier_ok(dev)))
4298 		goto drop;
4299 
4300 	skb = validate_xmit_skb_list(skb, dev, &again);
4301 	if (skb != orig_skb)
4302 		goto drop;
4303 
4304 	skb_set_queue_mapping(skb, queue_id);
4305 	txq = skb_get_tx_queue(dev, skb);
4306 
4307 	local_bh_disable();
4308 
4309 	dev_xmit_recursion_inc();
4310 	HARD_TX_LOCK(dev, txq, smp_processor_id());
4311 	if (!netif_xmit_frozen_or_drv_stopped(txq))
4312 		ret = netdev_start_xmit(skb, dev, txq, false);
4313 	HARD_TX_UNLOCK(dev, txq);
4314 	dev_xmit_recursion_dec();
4315 
4316 	local_bh_enable();
4317 	return ret;
4318 drop:
4319 	dev_core_stats_tx_dropped_inc(dev);
4320 	kfree_skb_list(skb);
4321 	return NET_XMIT_DROP;
4322 }
4323 EXPORT_SYMBOL(__dev_direct_xmit);
4324 
4325 /*************************************************************************
4326  *			Receiver routines
4327  *************************************************************************/
4328 
4329 int netdev_max_backlog __read_mostly = 1000;
4330 EXPORT_SYMBOL(netdev_max_backlog);
4331 
4332 int netdev_tstamp_prequeue __read_mostly = 1;
4333 unsigned int sysctl_skb_defer_max __read_mostly = 64;
4334 int netdev_budget __read_mostly = 300;
4335 /* Must be at least 2 jiffes to guarantee 1 jiffy timeout */
4336 unsigned int __read_mostly netdev_budget_usecs = 2 * USEC_PER_SEC / HZ;
4337 int weight_p __read_mostly = 64;           /* old backlog weight */
4338 int dev_weight_rx_bias __read_mostly = 1;  /* bias for backlog weight */
4339 int dev_weight_tx_bias __read_mostly = 1;  /* bias for output_queue quota */
4340 int dev_rx_weight __read_mostly = 64;
4341 int dev_tx_weight __read_mostly = 64;
4342 
4343 /* Called with irq disabled */
____napi_schedule(struct softnet_data * sd,struct napi_struct * napi)4344 static inline void ____napi_schedule(struct softnet_data *sd,
4345 				     struct napi_struct *napi)
4346 {
4347 	struct task_struct *thread;
4348 
4349 	lockdep_assert_irqs_disabled();
4350 
4351 	if (test_bit(NAPI_STATE_THREADED, &napi->state)) {
4352 		/* Paired with smp_mb__before_atomic() in
4353 		 * napi_enable()/dev_set_threaded().
4354 		 * Use READ_ONCE() to guarantee a complete
4355 		 * read on napi->thread. Only call
4356 		 * wake_up_process() when it's not NULL.
4357 		 */
4358 		thread = READ_ONCE(napi->thread);
4359 		if (thread) {
4360 			/* Avoid doing set_bit() if the thread is in
4361 			 * INTERRUPTIBLE state, cause napi_thread_wait()
4362 			 * makes sure to proceed with napi polling
4363 			 * if the thread is explicitly woken from here.
4364 			 */
4365 			if (READ_ONCE(thread->__state) != TASK_INTERRUPTIBLE)
4366 				set_bit(NAPI_STATE_SCHED_THREADED, &napi->state);
4367 			wake_up_process(thread);
4368 			return;
4369 		}
4370 	}
4371 
4372 	list_add_tail(&napi->poll_list, &sd->poll_list);
4373 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4374 }
4375 
4376 #ifdef CONFIG_RPS
4377 
4378 /* One global table that all flow-based protocols share. */
4379 struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
4380 EXPORT_SYMBOL(rps_sock_flow_table);
4381 u32 rps_cpu_mask __read_mostly;
4382 EXPORT_SYMBOL(rps_cpu_mask);
4383 
4384 struct static_key_false rps_needed __read_mostly;
4385 EXPORT_SYMBOL(rps_needed);
4386 struct static_key_false rfs_needed __read_mostly;
4387 EXPORT_SYMBOL(rfs_needed);
4388 
4389 static struct rps_dev_flow *
set_rps_cpu(struct net_device * dev,struct sk_buff * skb,struct rps_dev_flow * rflow,u16 next_cpu)4390 set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4391 	    struct rps_dev_flow *rflow, u16 next_cpu)
4392 {
4393 	if (next_cpu < nr_cpu_ids) {
4394 #ifdef CONFIG_RFS_ACCEL
4395 		struct netdev_rx_queue *rxqueue;
4396 		struct rps_dev_flow_table *flow_table;
4397 		struct rps_dev_flow *old_rflow;
4398 		u32 flow_id;
4399 		u16 rxq_index;
4400 		int rc;
4401 
4402 		/* Should we steer this flow to a different hardware queue? */
4403 		if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
4404 		    !(dev->features & NETIF_F_NTUPLE))
4405 			goto out;
4406 		rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
4407 		if (rxq_index == skb_get_rx_queue(skb))
4408 			goto out;
4409 
4410 		rxqueue = dev->_rx + rxq_index;
4411 		flow_table = rcu_dereference(rxqueue->rps_flow_table);
4412 		if (!flow_table)
4413 			goto out;
4414 		flow_id = skb_get_hash(skb) & flow_table->mask;
4415 		rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
4416 							rxq_index, flow_id);
4417 		if (rc < 0)
4418 			goto out;
4419 		old_rflow = rflow;
4420 		rflow = &flow_table->flows[flow_id];
4421 		rflow->filter = rc;
4422 		if (old_rflow->filter == rflow->filter)
4423 			old_rflow->filter = RPS_NO_FILTER;
4424 	out:
4425 #endif
4426 		rflow->last_qtail =
4427 			per_cpu(softnet_data, next_cpu).input_queue_head;
4428 	}
4429 
4430 	rflow->cpu = next_cpu;
4431 	return rflow;
4432 }
4433 
4434 /*
4435  * get_rps_cpu is called from netif_receive_skb and returns the target
4436  * CPU from the RPS map of the receiving queue for a given skb.
4437  * rcu_read_lock must be held on entry.
4438  */
get_rps_cpu(struct net_device * dev,struct sk_buff * skb,struct rps_dev_flow ** rflowp)4439 static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4440 		       struct rps_dev_flow **rflowp)
4441 {
4442 	const struct rps_sock_flow_table *sock_flow_table;
4443 	struct netdev_rx_queue *rxqueue = dev->_rx;
4444 	struct rps_dev_flow_table *flow_table;
4445 	struct rps_map *map;
4446 	int cpu = -1;
4447 	u32 tcpu;
4448 	u32 hash;
4449 
4450 	if (skb_rx_queue_recorded(skb)) {
4451 		u16 index = skb_get_rx_queue(skb);
4452 
4453 		if (unlikely(index >= dev->real_num_rx_queues)) {
4454 			WARN_ONCE(dev->real_num_rx_queues > 1,
4455 				  "%s received packet on queue %u, but number "
4456 				  "of RX queues is %u\n",
4457 				  dev->name, index, dev->real_num_rx_queues);
4458 			goto done;
4459 		}
4460 		rxqueue += index;
4461 	}
4462 
4463 	/* Avoid computing hash if RFS/RPS is not active for this rxqueue */
4464 
4465 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
4466 	map = rcu_dereference(rxqueue->rps_map);
4467 	if (!flow_table && !map)
4468 		goto done;
4469 
4470 	skb_reset_network_header(skb);
4471 	hash = skb_get_hash(skb);
4472 	if (!hash)
4473 		goto done;
4474 
4475 	sock_flow_table = rcu_dereference(rps_sock_flow_table);
4476 	if (flow_table && sock_flow_table) {
4477 		struct rps_dev_flow *rflow;
4478 		u32 next_cpu;
4479 		u32 ident;
4480 
4481 		/* First check into global flow table if there is a match */
4482 		ident = sock_flow_table->ents[hash & sock_flow_table->mask];
4483 		if ((ident ^ hash) & ~rps_cpu_mask)
4484 			goto try_rps;
4485 
4486 		next_cpu = ident & rps_cpu_mask;
4487 
4488 		/* OK, now we know there is a match,
4489 		 * we can look at the local (per receive queue) flow table
4490 		 */
4491 		rflow = &flow_table->flows[hash & flow_table->mask];
4492 		tcpu = rflow->cpu;
4493 
4494 		/*
4495 		 * If the desired CPU (where last recvmsg was done) is
4496 		 * different from current CPU (one in the rx-queue flow
4497 		 * table entry), switch if one of the following holds:
4498 		 *   - Current CPU is unset (>= nr_cpu_ids).
4499 		 *   - Current CPU is offline.
4500 		 *   - The current CPU's queue tail has advanced beyond the
4501 		 *     last packet that was enqueued using this table entry.
4502 		 *     This guarantees that all previous packets for the flow
4503 		 *     have been dequeued, thus preserving in order delivery.
4504 		 */
4505 		if (unlikely(tcpu != next_cpu) &&
4506 		    (tcpu >= nr_cpu_ids || !cpu_online(tcpu) ||
4507 		     ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
4508 		      rflow->last_qtail)) >= 0)) {
4509 			tcpu = next_cpu;
4510 			rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
4511 		}
4512 
4513 		if (tcpu < nr_cpu_ids && cpu_online(tcpu)) {
4514 			*rflowp = rflow;
4515 			cpu = tcpu;
4516 			goto done;
4517 		}
4518 	}
4519 
4520 try_rps:
4521 
4522 	if (map) {
4523 		tcpu = map->cpus[reciprocal_scale(hash, map->len)];
4524 		if (cpu_online(tcpu)) {
4525 			cpu = tcpu;
4526 			goto done;
4527 		}
4528 	}
4529 
4530 done:
4531 	return cpu;
4532 }
4533 
4534 #ifdef CONFIG_RFS_ACCEL
4535 
4536 /**
4537  * rps_may_expire_flow - check whether an RFS hardware filter may be removed
4538  * @dev: Device on which the filter was set
4539  * @rxq_index: RX queue index
4540  * @flow_id: Flow ID passed to ndo_rx_flow_steer()
4541  * @filter_id: Filter ID returned by ndo_rx_flow_steer()
4542  *
4543  * Drivers that implement ndo_rx_flow_steer() should periodically call
4544  * this function for each installed filter and remove the filters for
4545  * which it returns %true.
4546  */
rps_may_expire_flow(struct net_device * dev,u16 rxq_index,u32 flow_id,u16 filter_id)4547 bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
4548 			 u32 flow_id, u16 filter_id)
4549 {
4550 	struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
4551 	struct rps_dev_flow_table *flow_table;
4552 	struct rps_dev_flow *rflow;
4553 	bool expire = true;
4554 	unsigned int cpu;
4555 
4556 	rcu_read_lock();
4557 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
4558 	if (flow_table && flow_id <= flow_table->mask) {
4559 		rflow = &flow_table->flows[flow_id];
4560 		cpu = READ_ONCE(rflow->cpu);
4561 		if (rflow->filter == filter_id && cpu < nr_cpu_ids &&
4562 		    ((int)(per_cpu(softnet_data, cpu).input_queue_head -
4563 			   rflow->last_qtail) <
4564 		     (int)(10 * flow_table->mask)))
4565 			expire = false;
4566 	}
4567 	rcu_read_unlock();
4568 	return expire;
4569 }
4570 EXPORT_SYMBOL(rps_may_expire_flow);
4571 
4572 #endif /* CONFIG_RFS_ACCEL */
4573 
4574 /* Called from hardirq (IPI) context */
rps_trigger_softirq(void * data)4575 static void rps_trigger_softirq(void *data)
4576 {
4577 	struct softnet_data *sd = data;
4578 
4579 	____napi_schedule(sd, &sd->backlog);
4580 	sd->received_rps++;
4581 }
4582 
4583 #endif /* CONFIG_RPS */
4584 
4585 /* Called from hardirq (IPI) context */
trigger_rx_softirq(void * data)4586 static void trigger_rx_softirq(void *data)
4587 {
4588 	struct softnet_data *sd = data;
4589 
4590 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4591 	smp_store_release(&sd->defer_ipi_scheduled, 0);
4592 }
4593 
4594 /*
4595  * Check if this softnet_data structure is another cpu one
4596  * If yes, queue it to our IPI list and return 1
4597  * If no, return 0
4598  */
napi_schedule_rps(struct softnet_data * sd)4599 static int napi_schedule_rps(struct softnet_data *sd)
4600 {
4601 	struct softnet_data *mysd = this_cpu_ptr(&softnet_data);
4602 
4603 #ifdef CONFIG_RPS
4604 	if (sd != mysd) {
4605 		sd->rps_ipi_next = mysd->rps_ipi_list;
4606 		mysd->rps_ipi_list = sd;
4607 
4608 		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
4609 		return 1;
4610 	}
4611 #endif /* CONFIG_RPS */
4612 	__napi_schedule_irqoff(&mysd->backlog);
4613 	return 0;
4614 }
4615 
4616 #ifdef CONFIG_NET_FLOW_LIMIT
4617 int netdev_flow_limit_table_len __read_mostly = (1 << 12);
4618 #endif
4619 
skb_flow_limit(struct sk_buff * skb,unsigned int qlen)4620 static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen)
4621 {
4622 #ifdef CONFIG_NET_FLOW_LIMIT
4623 	struct sd_flow_limit *fl;
4624 	struct softnet_data *sd;
4625 	unsigned int old_flow, new_flow;
4626 
4627 	if (qlen < (READ_ONCE(netdev_max_backlog) >> 1))
4628 		return false;
4629 
4630 	sd = this_cpu_ptr(&softnet_data);
4631 
4632 	rcu_read_lock();
4633 	fl = rcu_dereference(sd->flow_limit);
4634 	if (fl) {
4635 		new_flow = skb_get_hash(skb) & (fl->num_buckets - 1);
4636 		old_flow = fl->history[fl->history_head];
4637 		fl->history[fl->history_head] = new_flow;
4638 
4639 		fl->history_head++;
4640 		fl->history_head &= FLOW_LIMIT_HISTORY - 1;
4641 
4642 		if (likely(fl->buckets[old_flow]))
4643 			fl->buckets[old_flow]--;
4644 
4645 		if (++fl->buckets[new_flow] > (FLOW_LIMIT_HISTORY >> 1)) {
4646 			fl->count++;
4647 			rcu_read_unlock();
4648 			return true;
4649 		}
4650 	}
4651 	rcu_read_unlock();
4652 #endif
4653 	return false;
4654 }
4655 
4656 /*
4657  * enqueue_to_backlog is called to queue an skb to a per CPU backlog
4658  * queue (may be a remote CPU queue).
4659  */
enqueue_to_backlog(struct sk_buff * skb,int cpu,unsigned int * qtail)4660 static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
4661 			      unsigned int *qtail)
4662 {
4663 	enum skb_drop_reason reason;
4664 	struct softnet_data *sd;
4665 	unsigned long flags;
4666 	unsigned int qlen;
4667 
4668 	reason = SKB_DROP_REASON_NOT_SPECIFIED;
4669 	sd = &per_cpu(softnet_data, cpu);
4670 
4671 	rps_lock_irqsave(sd, &flags);
4672 	if (!netif_running(skb->dev))
4673 		goto drop;
4674 	qlen = skb_queue_len(&sd->input_pkt_queue);
4675 	if (qlen <= READ_ONCE(netdev_max_backlog) && !skb_flow_limit(skb, qlen)) {
4676 		if (qlen) {
4677 enqueue:
4678 			__skb_queue_tail(&sd->input_pkt_queue, skb);
4679 			input_queue_tail_incr_save(sd, qtail);
4680 			rps_unlock_irq_restore(sd, &flags);
4681 			return NET_RX_SUCCESS;
4682 		}
4683 
4684 		/* Schedule NAPI for backlog device
4685 		 * We can use non atomic operation since we own the queue lock
4686 		 */
4687 		if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state))
4688 			napi_schedule_rps(sd);
4689 		goto enqueue;
4690 	}
4691 	reason = SKB_DROP_REASON_CPU_BACKLOG;
4692 
4693 drop:
4694 	sd->dropped++;
4695 	rps_unlock_irq_restore(sd, &flags);
4696 
4697 	dev_core_stats_rx_dropped_inc(skb->dev);
4698 	kfree_skb_reason(skb, reason);
4699 	return NET_RX_DROP;
4700 }
4701 
netif_get_rxqueue(struct sk_buff * skb)4702 static struct netdev_rx_queue *netif_get_rxqueue(struct sk_buff *skb)
4703 {
4704 	struct net_device *dev = skb->dev;
4705 	struct netdev_rx_queue *rxqueue;
4706 
4707 	rxqueue = dev->_rx;
4708 
4709 	if (skb_rx_queue_recorded(skb)) {
4710 		u16 index = skb_get_rx_queue(skb);
4711 
4712 		if (unlikely(index >= dev->real_num_rx_queues)) {
4713 			WARN_ONCE(dev->real_num_rx_queues > 1,
4714 				  "%s received packet on queue %u, but number "
4715 				  "of RX queues is %u\n",
4716 				  dev->name, index, dev->real_num_rx_queues);
4717 
4718 			return rxqueue; /* Return first rxqueue */
4719 		}
4720 		rxqueue += index;
4721 	}
4722 	return rxqueue;
4723 }
4724 
bpf_prog_run_generic_xdp(struct sk_buff * skb,struct xdp_buff * xdp,struct bpf_prog * xdp_prog)4725 u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp,
4726 			     struct bpf_prog *xdp_prog)
4727 {
4728 	void *orig_data, *orig_data_end, *hard_start;
4729 	struct netdev_rx_queue *rxqueue;
4730 	bool orig_bcast, orig_host;
4731 	u32 mac_len, frame_sz;
4732 	__be16 orig_eth_type;
4733 	struct ethhdr *eth;
4734 	u32 metalen, act;
4735 	int off;
4736 
4737 	/* The XDP program wants to see the packet starting at the MAC
4738 	 * header.
4739 	 */
4740 	mac_len = skb->data - skb_mac_header(skb);
4741 	hard_start = skb->data - skb_headroom(skb);
4742 
4743 	/* SKB "head" area always have tailroom for skb_shared_info */
4744 	frame_sz = (void *)skb_end_pointer(skb) - hard_start;
4745 	frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
4746 
4747 	rxqueue = netif_get_rxqueue(skb);
4748 	xdp_init_buff(xdp, frame_sz, &rxqueue->xdp_rxq);
4749 	xdp_prepare_buff(xdp, hard_start, skb_headroom(skb) - mac_len,
4750 			 skb_headlen(skb) + mac_len, true);
4751 
4752 	orig_data_end = xdp->data_end;
4753 	orig_data = xdp->data;
4754 	eth = (struct ethhdr *)xdp->data;
4755 	orig_host = ether_addr_equal_64bits(eth->h_dest, skb->dev->dev_addr);
4756 	orig_bcast = is_multicast_ether_addr_64bits(eth->h_dest);
4757 	orig_eth_type = eth->h_proto;
4758 
4759 	act = bpf_prog_run_xdp(xdp_prog, xdp);
4760 
4761 	/* check if bpf_xdp_adjust_head was used */
4762 	off = xdp->data - orig_data;
4763 	if (off) {
4764 		if (off > 0)
4765 			__skb_pull(skb, off);
4766 		else if (off < 0)
4767 			__skb_push(skb, -off);
4768 
4769 		skb->mac_header += off;
4770 		skb_reset_network_header(skb);
4771 	}
4772 
4773 	/* check if bpf_xdp_adjust_tail was used */
4774 	off = xdp->data_end - orig_data_end;
4775 	if (off != 0) {
4776 		skb_set_tail_pointer(skb, xdp->data_end - xdp->data);
4777 		skb->len += off; /* positive on grow, negative on shrink */
4778 	}
4779 
4780 	/* check if XDP changed eth hdr such SKB needs update */
4781 	eth = (struct ethhdr *)xdp->data;
4782 	if ((orig_eth_type != eth->h_proto) ||
4783 	    (orig_host != ether_addr_equal_64bits(eth->h_dest,
4784 						  skb->dev->dev_addr)) ||
4785 	    (orig_bcast != is_multicast_ether_addr_64bits(eth->h_dest))) {
4786 		__skb_push(skb, ETH_HLEN);
4787 		skb->pkt_type = PACKET_HOST;
4788 		skb->protocol = eth_type_trans(skb, skb->dev);
4789 	}
4790 
4791 	/* Redirect/Tx gives L2 packet, code that will reuse skb must __skb_pull
4792 	 * before calling us again on redirect path. We do not call do_redirect
4793 	 * as we leave that up to the caller.
4794 	 *
4795 	 * Caller is responsible for managing lifetime of skb (i.e. calling
4796 	 * kfree_skb in response to actions it cannot handle/XDP_DROP).
4797 	 */
4798 	switch (act) {
4799 	case XDP_REDIRECT:
4800 	case XDP_TX:
4801 		__skb_push(skb, mac_len);
4802 		break;
4803 	case XDP_PASS:
4804 		metalen = xdp->data - xdp->data_meta;
4805 		if (metalen)
4806 			skb_metadata_set(skb, metalen);
4807 		break;
4808 	}
4809 
4810 	return act;
4811 }
4812 
netif_receive_generic_xdp(struct sk_buff * skb,struct xdp_buff * xdp,struct bpf_prog * xdp_prog)4813 static u32 netif_receive_generic_xdp(struct sk_buff *skb,
4814 				     struct xdp_buff *xdp,
4815 				     struct bpf_prog *xdp_prog)
4816 {
4817 	u32 act = XDP_DROP;
4818 
4819 	/* Reinjected packets coming from act_mirred or similar should
4820 	 * not get XDP generic processing.
4821 	 */
4822 	if (skb_is_redirected(skb))
4823 		return XDP_PASS;
4824 
4825 	/* XDP packets must be linear and must have sufficient headroom
4826 	 * of XDP_PACKET_HEADROOM bytes. This is the guarantee that also
4827 	 * native XDP provides, thus we need to do it here as well.
4828 	 */
4829 	if (skb_cloned(skb) || skb_is_nonlinear(skb) ||
4830 	    skb_headroom(skb) < XDP_PACKET_HEADROOM) {
4831 		int hroom = XDP_PACKET_HEADROOM - skb_headroom(skb);
4832 		int troom = skb->tail + skb->data_len - skb->end;
4833 
4834 		/* In case we have to go down the path and also linearize,
4835 		 * then lets do the pskb_expand_head() work just once here.
4836 		 */
4837 		if (pskb_expand_head(skb,
4838 				     hroom > 0 ? ALIGN(hroom, NET_SKB_PAD) : 0,
4839 				     troom > 0 ? troom + 128 : 0, GFP_ATOMIC))
4840 			goto do_drop;
4841 		if (skb_linearize(skb))
4842 			goto do_drop;
4843 	}
4844 
4845 	act = bpf_prog_run_generic_xdp(skb, xdp, xdp_prog);
4846 	switch (act) {
4847 	case XDP_REDIRECT:
4848 	case XDP_TX:
4849 	case XDP_PASS:
4850 		break;
4851 	default:
4852 		bpf_warn_invalid_xdp_action(skb->dev, xdp_prog, act);
4853 		fallthrough;
4854 	case XDP_ABORTED:
4855 		trace_xdp_exception(skb->dev, xdp_prog, act);
4856 		fallthrough;
4857 	case XDP_DROP:
4858 	do_drop:
4859 		kfree_skb(skb);
4860 		break;
4861 	}
4862 
4863 	return act;
4864 }
4865 
4866 /* When doing generic XDP we have to bypass the qdisc layer and the
4867  * network taps in order to match in-driver-XDP behavior. This also means
4868  * that XDP packets are able to starve other packets going through a qdisc,
4869  * and DDOS attacks will be more effective. In-driver-XDP use dedicated TX
4870  * queues, so they do not have this starvation issue.
4871  */
generic_xdp_tx(struct sk_buff * skb,struct bpf_prog * xdp_prog)4872 void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
4873 {
4874 	struct net_device *dev = skb->dev;
4875 	struct netdev_queue *txq;
4876 	bool free_skb = true;
4877 	int cpu, rc;
4878 
4879 	txq = netdev_core_pick_tx(dev, skb, NULL);
4880 	cpu = smp_processor_id();
4881 	HARD_TX_LOCK(dev, txq, cpu);
4882 	if (!netif_xmit_frozen_or_drv_stopped(txq)) {
4883 		rc = netdev_start_xmit(skb, dev, txq, 0);
4884 		if (dev_xmit_complete(rc))
4885 			free_skb = false;
4886 	}
4887 	HARD_TX_UNLOCK(dev, txq);
4888 	if (free_skb) {
4889 		trace_xdp_exception(dev, xdp_prog, XDP_TX);
4890 		dev_core_stats_tx_dropped_inc(dev);
4891 		kfree_skb(skb);
4892 	}
4893 }
4894 
4895 static DEFINE_STATIC_KEY_FALSE(generic_xdp_needed_key);
4896 
do_xdp_generic(struct bpf_prog * xdp_prog,struct sk_buff * skb)4897 int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb)
4898 {
4899 	if (xdp_prog) {
4900 		struct xdp_buff xdp;
4901 		u32 act;
4902 		int err;
4903 
4904 		act = netif_receive_generic_xdp(skb, &xdp, xdp_prog);
4905 		if (act != XDP_PASS) {
4906 			switch (act) {
4907 			case XDP_REDIRECT:
4908 				err = xdp_do_generic_redirect(skb->dev, skb,
4909 							      &xdp, xdp_prog);
4910 				if (err)
4911 					goto out_redir;
4912 				break;
4913 			case XDP_TX:
4914 				generic_xdp_tx(skb, xdp_prog);
4915 				break;
4916 			}
4917 			return XDP_DROP;
4918 		}
4919 	}
4920 	return XDP_PASS;
4921 out_redir:
4922 	kfree_skb_reason(skb, SKB_DROP_REASON_XDP);
4923 	return XDP_DROP;
4924 }
4925 EXPORT_SYMBOL_GPL(do_xdp_generic);
4926 
netif_rx_internal(struct sk_buff * skb)4927 static int netif_rx_internal(struct sk_buff *skb)
4928 {
4929 	int ret;
4930 
4931 	net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
4932 
4933 	trace_netif_rx(skb);
4934 
4935 #ifdef CONFIG_RPS
4936 	if (static_branch_unlikely(&rps_needed)) {
4937 		struct rps_dev_flow voidflow, *rflow = &voidflow;
4938 		int cpu;
4939 
4940 		rcu_read_lock();
4941 
4942 		cpu = get_rps_cpu(skb->dev, skb, &rflow);
4943 		if (cpu < 0)
4944 			cpu = smp_processor_id();
4945 
4946 		ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
4947 
4948 		rcu_read_unlock();
4949 	} else
4950 #endif
4951 	{
4952 		unsigned int qtail;
4953 
4954 		ret = enqueue_to_backlog(skb, smp_processor_id(), &qtail);
4955 	}
4956 	return ret;
4957 }
4958 
4959 /**
4960  *	__netif_rx	-	Slightly optimized version of netif_rx
4961  *	@skb: buffer to post
4962  *
4963  *	This behaves as netif_rx except that it does not disable bottom halves.
4964  *	As a result this function may only be invoked from the interrupt context
4965  *	(either hard or soft interrupt).
4966  */
__netif_rx(struct sk_buff * skb)4967 int __netif_rx(struct sk_buff *skb)
4968 {
4969 	int ret;
4970 
4971 	lockdep_assert_once(hardirq_count() | softirq_count());
4972 
4973 	trace_netif_rx_entry(skb);
4974 	ret = netif_rx_internal(skb);
4975 	trace_netif_rx_exit(ret);
4976 	return ret;
4977 }
4978 EXPORT_SYMBOL(__netif_rx);
4979 
4980 /**
4981  *	netif_rx	-	post buffer to the network code
4982  *	@skb: buffer to post
4983  *
4984  *	This function receives a packet from a device driver and queues it for
4985  *	the upper (protocol) levels to process via the backlog NAPI device. It
4986  *	always succeeds. The buffer may be dropped during processing for
4987  *	congestion control or by the protocol layers.
4988  *	The network buffer is passed via the backlog NAPI device. Modern NIC
4989  *	driver should use NAPI and GRO.
4990  *	This function can used from interrupt and from process context. The
4991  *	caller from process context must not disable interrupts before invoking
4992  *	this function.
4993  *
4994  *	return values:
4995  *	NET_RX_SUCCESS	(no congestion)
4996  *	NET_RX_DROP     (packet was dropped)
4997  *
4998  */
netif_rx(struct sk_buff * skb)4999 int netif_rx(struct sk_buff *skb)
5000 {
5001 	bool need_bh_off = !(hardirq_count() | softirq_count());
5002 	int ret;
5003 
5004 	if (need_bh_off)
5005 		local_bh_disable();
5006 	trace_netif_rx_entry(skb);
5007 	ret = netif_rx_internal(skb);
5008 	trace_netif_rx_exit(ret);
5009 	if (need_bh_off)
5010 		local_bh_enable();
5011 	return ret;
5012 }
5013 EXPORT_SYMBOL(netif_rx);
5014 
net_tx_action(struct softirq_action * h)5015 static __latent_entropy void net_tx_action(struct softirq_action *h)
5016 {
5017 	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
5018 
5019 	if (sd->completion_queue) {
5020 		struct sk_buff *clist;
5021 
5022 		local_irq_disable();
5023 		clist = sd->completion_queue;
5024 		sd->completion_queue = NULL;
5025 		local_irq_enable();
5026 
5027 		while (clist) {
5028 			struct sk_buff *skb = clist;
5029 
5030 			clist = clist->next;
5031 
5032 			WARN_ON(refcount_read(&skb->users));
5033 			if (likely(get_kfree_skb_cb(skb)->reason == SKB_REASON_CONSUMED))
5034 				trace_consume_skb(skb);
5035 			else
5036 				trace_kfree_skb(skb, net_tx_action,
5037 						SKB_DROP_REASON_NOT_SPECIFIED);
5038 
5039 			if (skb->fclone != SKB_FCLONE_UNAVAILABLE)
5040 				__kfree_skb(skb);
5041 			else
5042 				__kfree_skb_defer(skb);
5043 		}
5044 	}
5045 
5046 	if (sd->output_queue) {
5047 		struct Qdisc *head;
5048 
5049 		local_irq_disable();
5050 		head = sd->output_queue;
5051 		sd->output_queue = NULL;
5052 		sd->output_queue_tailp = &sd->output_queue;
5053 		local_irq_enable();
5054 
5055 		rcu_read_lock();
5056 
5057 		while (head) {
5058 			struct Qdisc *q = head;
5059 			spinlock_t *root_lock = NULL;
5060 
5061 			head = head->next_sched;
5062 
5063 			/* We need to make sure head->next_sched is read
5064 			 * before clearing __QDISC_STATE_SCHED
5065 			 */
5066 			smp_mb__before_atomic();
5067 
5068 			if (!(q->flags & TCQ_F_NOLOCK)) {
5069 				root_lock = qdisc_lock(q);
5070 				spin_lock(root_lock);
5071 			} else if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED,
5072 						     &q->state))) {
5073 				/* There is a synchronize_net() between
5074 				 * STATE_DEACTIVATED flag being set and
5075 				 * qdisc_reset()/some_qdisc_is_busy() in
5076 				 * dev_deactivate(), so we can safely bail out
5077 				 * early here to avoid data race between
5078 				 * qdisc_deactivate() and some_qdisc_is_busy()
5079 				 * for lockless qdisc.
5080 				 */
5081 				clear_bit(__QDISC_STATE_SCHED, &q->state);
5082 				continue;
5083 			}
5084 
5085 			clear_bit(__QDISC_STATE_SCHED, &q->state);
5086 			qdisc_run(q);
5087 			if (root_lock)
5088 				spin_unlock(root_lock);
5089 		}
5090 
5091 		rcu_read_unlock();
5092 	}
5093 
5094 	xfrm_dev_backlog(sd);
5095 }
5096 
5097 #if IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_ATM_LANE)
5098 /* This hook is defined here for ATM LANE */
5099 int (*br_fdb_test_addr_hook)(struct net_device *dev,
5100 			     unsigned char *addr) __read_mostly;
5101 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
5102 #endif
5103 
5104 static 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)5105 sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
5106 		   struct net_device *orig_dev, bool *another)
5107 {
5108 #ifdef CONFIG_NET_CLS_ACT
5109 	struct mini_Qdisc *miniq = rcu_dereference_bh(skb->dev->miniq_ingress);
5110 	struct tcf_result cl_res;
5111 
5112 	/* If there's at least one ingress present somewhere (so
5113 	 * we get here via enabled static key), remaining devices
5114 	 * that are not configured with an ingress qdisc will bail
5115 	 * out here.
5116 	 */
5117 	if (!miniq)
5118 		return skb;
5119 
5120 	if (*pt_prev) {
5121 		*ret = deliver_skb(skb, *pt_prev, orig_dev);
5122 		*pt_prev = NULL;
5123 	}
5124 
5125 	qdisc_skb_cb(skb)->pkt_len = skb->len;
5126 	tc_skb_cb(skb)->mru = 0;
5127 	tc_skb_cb(skb)->post_ct = false;
5128 	skb->tc_at_ingress = 1;
5129 	mini_qdisc_bstats_cpu_update(miniq, skb);
5130 
5131 	switch (tcf_classify(skb, miniq->block, miniq->filter_list, &cl_res, false)) {
5132 	case TC_ACT_OK:
5133 	case TC_ACT_RECLASSIFY:
5134 		skb->tc_index = TC_H_MIN(cl_res.classid);
5135 		break;
5136 	case TC_ACT_SHOT:
5137 		mini_qdisc_qstats_cpu_drop(miniq);
5138 		kfree_skb_reason(skb, SKB_DROP_REASON_TC_INGRESS);
5139 		*ret = NET_RX_DROP;
5140 		return NULL;
5141 	case TC_ACT_STOLEN:
5142 	case TC_ACT_QUEUED:
5143 	case TC_ACT_TRAP:
5144 		consume_skb(skb);
5145 		*ret = NET_RX_SUCCESS;
5146 		return NULL;
5147 	case TC_ACT_REDIRECT:
5148 		/* skb_mac_header check was done by cls/act_bpf, so
5149 		 * we can safely push the L2 header back before
5150 		 * redirecting to another netdev
5151 		 */
5152 		__skb_push(skb, skb->mac_len);
5153 		if (skb_do_redirect(skb) == -EAGAIN) {
5154 			__skb_pull(skb, skb->mac_len);
5155 			*another = true;
5156 			break;
5157 		}
5158 		*ret = NET_RX_SUCCESS;
5159 		return NULL;
5160 	case TC_ACT_CONSUMED:
5161 		*ret = NET_RX_SUCCESS;
5162 		return NULL;
5163 	default:
5164 		break;
5165 	}
5166 #endif /* CONFIG_NET_CLS_ACT */
5167 	return skb;
5168 }
5169 
5170 /**
5171  *	netdev_is_rx_handler_busy - check if receive handler is registered
5172  *	@dev: device to check
5173  *
5174  *	Check if a receive handler is already registered for a given device.
5175  *	Return true if there one.
5176  *
5177  *	The caller must hold the rtnl_mutex.
5178  */
netdev_is_rx_handler_busy(struct net_device * dev)5179 bool netdev_is_rx_handler_busy(struct net_device *dev)
5180 {
5181 	ASSERT_RTNL();
5182 	return dev && rtnl_dereference(dev->rx_handler);
5183 }
5184 EXPORT_SYMBOL_GPL(netdev_is_rx_handler_busy);
5185 
5186 /**
5187  *	netdev_rx_handler_register - register receive handler
5188  *	@dev: device to register a handler for
5189  *	@rx_handler: receive handler to register
5190  *	@rx_handler_data: data pointer that is used by rx handler
5191  *
5192  *	Register a receive handler for a device. This handler will then be
5193  *	called from __netif_receive_skb. A negative errno code is returned
5194  *	on a failure.
5195  *
5196  *	The caller must hold the rtnl_mutex.
5197  *
5198  *	For a general description of rx_handler, see enum rx_handler_result.
5199  */
netdev_rx_handler_register(struct net_device * dev,rx_handler_func_t * rx_handler,void * rx_handler_data)5200 int netdev_rx_handler_register(struct net_device *dev,
5201 			       rx_handler_func_t *rx_handler,
5202 			       void *rx_handler_data)
5203 {
5204 	if (netdev_is_rx_handler_busy(dev))
5205 		return -EBUSY;
5206 
5207 	if (dev->priv_flags & IFF_NO_RX_HANDLER)
5208 		return -EINVAL;
5209 
5210 	/* Note: rx_handler_data must be set before rx_handler */
5211 	rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
5212 	rcu_assign_pointer(dev->rx_handler, rx_handler);
5213 
5214 	return 0;
5215 }
5216 EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
5217 
5218 /**
5219  *	netdev_rx_handler_unregister - unregister receive handler
5220  *	@dev: device to unregister a handler from
5221  *
5222  *	Unregister a receive handler from a device.
5223  *
5224  *	The caller must hold the rtnl_mutex.
5225  */
netdev_rx_handler_unregister(struct net_device * dev)5226 void netdev_rx_handler_unregister(struct net_device *dev)
5227 {
5228 
5229 	ASSERT_RTNL();
5230 	RCU_INIT_POINTER(dev->rx_handler, NULL);
5231 	/* a reader seeing a non NULL rx_handler in a rcu_read_lock()
5232 	 * section has a guarantee to see a non NULL rx_handler_data
5233 	 * as well.
5234 	 */
5235 	synchronize_net();
5236 	RCU_INIT_POINTER(dev->rx_handler_data, NULL);
5237 }
5238 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
5239 
5240 /*
5241  * Limit the use of PFMEMALLOC reserves to those protocols that implement
5242  * the special handling of PFMEMALLOC skbs.
5243  */
skb_pfmemalloc_protocol(struct sk_buff * skb)5244 static bool skb_pfmemalloc_protocol(struct sk_buff *skb)
5245 {
5246 	switch (skb->protocol) {
5247 	case htons(ETH_P_ARP):
5248 	case htons(ETH_P_IP):
5249 	case htons(ETH_P_IPV6):
5250 	case htons(ETH_P_8021Q):
5251 	case htons(ETH_P_8021AD):
5252 		return true;
5253 	default:
5254 		return false;
5255 	}
5256 }
5257 
nf_ingress(struct sk_buff * skb,struct packet_type ** pt_prev,int * ret,struct net_device * orig_dev)5258 static inline int nf_ingress(struct sk_buff *skb, struct packet_type **pt_prev,
5259 			     int *ret, struct net_device *orig_dev)
5260 {
5261 	if (nf_hook_ingress_active(skb)) {
5262 		int ingress_retval;
5263 
5264 		if (*pt_prev) {
5265 			*ret = deliver_skb(skb, *pt_prev, orig_dev);
5266 			*pt_prev = NULL;
5267 		}
5268 
5269 		rcu_read_lock();
5270 		ingress_retval = nf_hook_ingress(skb);
5271 		rcu_read_unlock();
5272 		return ingress_retval;
5273 	}
5274 	return 0;
5275 }
5276 
__netif_receive_skb_core(struct sk_buff ** pskb,bool pfmemalloc,struct packet_type ** ppt_prev)5277 static int __netif_receive_skb_core(struct sk_buff **pskb, bool pfmemalloc,
5278 				    struct packet_type **ppt_prev)
5279 {
5280 	struct packet_type *ptype, *pt_prev;
5281 	rx_handler_func_t *rx_handler;
5282 	struct sk_buff *skb = *pskb;
5283 	struct net_device *orig_dev;
5284 	bool deliver_exact = false;
5285 	int ret = NET_RX_DROP;
5286 	__be16 type;
5287 
5288 	net_timestamp_check(!READ_ONCE(netdev_tstamp_prequeue), skb);
5289 
5290 	trace_netif_receive_skb(skb);
5291 
5292 	orig_dev = skb->dev;
5293 
5294 	skb_reset_network_header(skb);
5295 	if (!skb_transport_header_was_set(skb))
5296 		skb_reset_transport_header(skb);
5297 	skb_reset_mac_len(skb);
5298 
5299 	pt_prev = NULL;
5300 
5301 another_round:
5302 	skb->skb_iif = skb->dev->ifindex;
5303 
5304 	__this_cpu_inc(softnet_data.processed);
5305 
5306 	if (static_branch_unlikely(&generic_xdp_needed_key)) {
5307 		int ret2;
5308 
5309 		migrate_disable();
5310 		ret2 = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog), skb);
5311 		migrate_enable();
5312 
5313 		if (ret2 != XDP_PASS) {
5314 			ret = NET_RX_DROP;
5315 			goto out;
5316 		}
5317 	}
5318 
5319 	if (eth_type_vlan(skb->protocol)) {
5320 		skb = skb_vlan_untag(skb);
5321 		if (unlikely(!skb))
5322 			goto out;
5323 	}
5324 
5325 	if (skb_skip_tc_classify(skb))
5326 		goto skip_classify;
5327 
5328 	if (pfmemalloc)
5329 		goto skip_taps;
5330 
5331 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
5332 		if (pt_prev)
5333 			ret = deliver_skb(skb, pt_prev, orig_dev);
5334 		pt_prev = ptype;
5335 	}
5336 
5337 	list_for_each_entry_rcu(ptype, &skb->dev->ptype_all, list) {
5338 		if (pt_prev)
5339 			ret = deliver_skb(skb, pt_prev, orig_dev);
5340 		pt_prev = ptype;
5341 	}
5342 
5343 skip_taps:
5344 #ifdef CONFIG_NET_INGRESS
5345 	if (static_branch_unlikely(&ingress_needed_key)) {
5346 		bool another = false;
5347 
5348 		nf_skip_egress(skb, true);
5349 		skb = sch_handle_ingress(skb, &pt_prev, &ret, orig_dev,
5350 					 &another);
5351 		if (another)
5352 			goto another_round;
5353 		if (!skb)
5354 			goto out;
5355 
5356 		nf_skip_egress(skb, false);
5357 		if (nf_ingress(skb, &pt_prev, &ret, orig_dev) < 0)
5358 			goto out;
5359 	}
5360 #endif
5361 	skb_reset_redirect(skb);
5362 skip_classify:
5363 	if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
5364 		goto drop;
5365 
5366 	if (skb_vlan_tag_present(skb)) {
5367 		if (pt_prev) {
5368 			ret = deliver_skb(skb, pt_prev, orig_dev);
5369 			pt_prev = NULL;
5370 		}
5371 		if (vlan_do_receive(&skb))
5372 			goto another_round;
5373 		else if (unlikely(!skb))
5374 			goto out;
5375 	}
5376 
5377 	rx_handler = rcu_dereference(skb->dev->rx_handler);
5378 	if (rx_handler) {
5379 		if (pt_prev) {
5380 			ret = deliver_skb(skb, pt_prev, orig_dev);
5381 			pt_prev = NULL;
5382 		}
5383 		switch (rx_handler(&skb)) {
5384 		case RX_HANDLER_CONSUMED:
5385 			ret = NET_RX_SUCCESS;
5386 			goto out;
5387 		case RX_HANDLER_ANOTHER:
5388 			goto another_round;
5389 		case RX_HANDLER_EXACT:
5390 			deliver_exact = true;
5391 			break;
5392 		case RX_HANDLER_PASS:
5393 			break;
5394 		default:
5395 			BUG();
5396 		}
5397 	}
5398 
5399 	if (unlikely(skb_vlan_tag_present(skb)) && !netdev_uses_dsa(skb->dev)) {
5400 check_vlan_id:
5401 		if (skb_vlan_tag_get_id(skb)) {
5402 			/* Vlan id is non 0 and vlan_do_receive() above couldn't
5403 			 * find vlan device.
5404 			 */
5405 			skb->pkt_type = PACKET_OTHERHOST;
5406 		} else if (eth_type_vlan(skb->protocol)) {
5407 			/* Outer header is 802.1P with vlan 0, inner header is
5408 			 * 802.1Q or 802.1AD and vlan_do_receive() above could
5409 			 * not find vlan dev for vlan id 0.
5410 			 */
5411 			__vlan_hwaccel_clear_tag(skb);
5412 			skb = skb_vlan_untag(skb);
5413 			if (unlikely(!skb))
5414 				goto out;
5415 			if (vlan_do_receive(&skb))
5416 				/* After stripping off 802.1P header with vlan 0
5417 				 * vlan dev is found for inner header.
5418 				 */
5419 				goto another_round;
5420 			else if (unlikely(!skb))
5421 				goto out;
5422 			else
5423 				/* We have stripped outer 802.1P vlan 0 header.
5424 				 * But could not find vlan dev.
5425 				 * check again for vlan id to set OTHERHOST.
5426 				 */
5427 				goto check_vlan_id;
5428 		}
5429 		/* Note: we might in the future use prio bits
5430 		 * and set skb->priority like in vlan_do_receive()
5431 		 * For the time being, just ignore Priority Code Point
5432 		 */
5433 		__vlan_hwaccel_clear_tag(skb);
5434 	}
5435 
5436 	type = skb->protocol;
5437 
5438 	/* deliver only exact match when indicated */
5439 	if (likely(!deliver_exact)) {
5440 		deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5441 				       &ptype_base[ntohs(type) &
5442 						   PTYPE_HASH_MASK]);
5443 	}
5444 
5445 	deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5446 			       &orig_dev->ptype_specific);
5447 
5448 	if (unlikely(skb->dev != orig_dev)) {
5449 		deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5450 				       &skb->dev->ptype_specific);
5451 	}
5452 
5453 	if (pt_prev) {
5454 		if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
5455 			goto drop;
5456 		*ppt_prev = pt_prev;
5457 	} else {
5458 drop:
5459 		if (!deliver_exact)
5460 			dev_core_stats_rx_dropped_inc(skb->dev);
5461 		else
5462 			dev_core_stats_rx_nohandler_inc(skb->dev);
5463 		kfree_skb_reason(skb, SKB_DROP_REASON_UNHANDLED_PROTO);
5464 		/* Jamal, now you will not able to escape explaining
5465 		 * me how you were going to use this. :-)
5466 		 */
5467 		ret = NET_RX_DROP;
5468 	}
5469 
5470 out:
5471 	/* The invariant here is that if *ppt_prev is not NULL
5472 	 * then skb should also be non-NULL.
5473 	 *
5474 	 * Apparently *ppt_prev assignment above holds this invariant due to
5475 	 * skb dereferencing near it.
5476 	 */
5477 	*pskb = skb;
5478 	return ret;
5479 }
5480 
__netif_receive_skb_one_core(struct sk_buff * skb,bool pfmemalloc)5481 static int __netif_receive_skb_one_core(struct sk_buff *skb, bool pfmemalloc)
5482 {
5483 	struct net_device *orig_dev = skb->dev;
5484 	struct packet_type *pt_prev = NULL;
5485 	int ret;
5486 
5487 	ret = __netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5488 	if (pt_prev)
5489 		ret = INDIRECT_CALL_INET(pt_prev->func, ipv6_rcv, ip_rcv, skb,
5490 					 skb->dev, pt_prev, orig_dev);
5491 	return ret;
5492 }
5493 
5494 /**
5495  *	netif_receive_skb_core - special purpose version of netif_receive_skb
5496  *	@skb: buffer to process
5497  *
5498  *	More direct receive version of netif_receive_skb().  It should
5499  *	only be used by callers that have a need to skip RPS and Generic XDP.
5500  *	Caller must also take care of handling if ``(page_is_)pfmemalloc``.
5501  *
5502  *	This function may only be called from softirq context and interrupts
5503  *	should be enabled.
5504  *
5505  *	Return values (usually ignored):
5506  *	NET_RX_SUCCESS: no congestion
5507  *	NET_RX_DROP: packet was dropped
5508  */
netif_receive_skb_core(struct sk_buff * skb)5509 int netif_receive_skb_core(struct sk_buff *skb)
5510 {
5511 	int ret;
5512 
5513 	rcu_read_lock();
5514 	ret = __netif_receive_skb_one_core(skb, false);
5515 	rcu_read_unlock();
5516 
5517 	return ret;
5518 }
5519 EXPORT_SYMBOL(netif_receive_skb_core);
5520 
__netif_receive_skb_list_ptype(struct list_head * head,struct packet_type * pt_prev,struct net_device * orig_dev)5521 static inline void __netif_receive_skb_list_ptype(struct list_head *head,
5522 						  struct packet_type *pt_prev,
5523 						  struct net_device *orig_dev)
5524 {
5525 	struct sk_buff *skb, *next;
5526 
5527 	if (!pt_prev)
5528 		return;
5529 	if (list_empty(head))
5530 		return;
5531 	if (pt_prev->list_func != NULL)
5532 		INDIRECT_CALL_INET(pt_prev->list_func, ipv6_list_rcv,
5533 				   ip_list_rcv, head, pt_prev, orig_dev);
5534 	else
5535 		list_for_each_entry_safe(skb, next, head, list) {
5536 			skb_list_del_init(skb);
5537 			pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
5538 		}
5539 }
5540 
__netif_receive_skb_list_core(struct list_head * head,bool pfmemalloc)5541 static void __netif_receive_skb_list_core(struct list_head *head, bool pfmemalloc)
5542 {
5543 	/* Fast-path assumptions:
5544 	 * - There is no RX handler.
5545 	 * - Only one packet_type matches.
5546 	 * If either of these fails, we will end up doing some per-packet
5547 	 * processing in-line, then handling the 'last ptype' for the whole
5548 	 * sublist.  This can't cause out-of-order delivery to any single ptype,
5549 	 * because the 'last ptype' must be constant across the sublist, and all
5550 	 * other ptypes are handled per-packet.
5551 	 */
5552 	/* Current (common) ptype of sublist */
5553 	struct packet_type *pt_curr = NULL;
5554 	/* Current (common) orig_dev of sublist */
5555 	struct net_device *od_curr = NULL;
5556 	struct list_head sublist;
5557 	struct sk_buff *skb, *next;
5558 
5559 	INIT_LIST_HEAD(&sublist);
5560 	list_for_each_entry_safe(skb, next, head, list) {
5561 		struct net_device *orig_dev = skb->dev;
5562 		struct packet_type *pt_prev = NULL;
5563 
5564 		skb_list_del_init(skb);
5565 		__netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5566 		if (!pt_prev)
5567 			continue;
5568 		if (pt_curr != pt_prev || od_curr != orig_dev) {
5569 			/* dispatch old sublist */
5570 			__netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5571 			/* start new sublist */
5572 			INIT_LIST_HEAD(&sublist);
5573 			pt_curr = pt_prev;
5574 			od_curr = orig_dev;
5575 		}
5576 		list_add_tail(&skb->list, &sublist);
5577 	}
5578 
5579 	/* dispatch final sublist */
5580 	__netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5581 }
5582 
__netif_receive_skb(struct sk_buff * skb)5583 static int __netif_receive_skb(struct sk_buff *skb)
5584 {
5585 	int ret;
5586 
5587 	if (sk_memalloc_socks() && skb_pfmemalloc(skb)) {
5588 		unsigned int noreclaim_flag;
5589 
5590 		/*
5591 		 * PFMEMALLOC skbs are special, they should
5592 		 * - be delivered to SOCK_MEMALLOC sockets only
5593 		 * - stay away from userspace
5594 		 * - have bounded memory usage
5595 		 *
5596 		 * Use PF_MEMALLOC as this saves us from propagating the allocation
5597 		 * context down to all allocation sites.
5598 		 */
5599 		noreclaim_flag = memalloc_noreclaim_save();
5600 		ret = __netif_receive_skb_one_core(skb, true);
5601 		memalloc_noreclaim_restore(noreclaim_flag);
5602 	} else
5603 		ret = __netif_receive_skb_one_core(skb, false);
5604 
5605 	return ret;
5606 }
5607 
__netif_receive_skb_list(struct list_head * head)5608 static void __netif_receive_skb_list(struct list_head *head)
5609 {
5610 	unsigned long noreclaim_flag = 0;
5611 	struct sk_buff *skb, *next;
5612 	bool pfmemalloc = false; /* Is current sublist PF_MEMALLOC? */
5613 
5614 	list_for_each_entry_safe(skb, next, head, list) {
5615 		if ((sk_memalloc_socks() && skb_pfmemalloc(skb)) != pfmemalloc) {
5616 			struct list_head sublist;
5617 
5618 			/* Handle the previous sublist */
5619 			list_cut_before(&sublist, head, &skb->list);
5620 			if (!list_empty(&sublist))
5621 				__netif_receive_skb_list_core(&sublist, pfmemalloc);
5622 			pfmemalloc = !pfmemalloc;
5623 			/* See comments in __netif_receive_skb */
5624 			if (pfmemalloc)
5625 				noreclaim_flag = memalloc_noreclaim_save();
5626 			else
5627 				memalloc_noreclaim_restore(noreclaim_flag);
5628 		}
5629 	}
5630 	/* Handle the remaining sublist */
5631 	if (!list_empty(head))
5632 		__netif_receive_skb_list_core(head, pfmemalloc);
5633 	/* Restore pflags */
5634 	if (pfmemalloc)
5635 		memalloc_noreclaim_restore(noreclaim_flag);
5636 }
5637 
generic_xdp_install(struct net_device * dev,struct netdev_bpf * xdp)5638 static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
5639 {
5640 	struct bpf_prog *old = rtnl_dereference(dev->xdp_prog);
5641 	struct bpf_prog *new = xdp->prog;
5642 	int ret = 0;
5643 
5644 	switch (xdp->command) {
5645 	case XDP_SETUP_PROG:
5646 		rcu_assign_pointer(dev->xdp_prog, new);
5647 		if (old)
5648 			bpf_prog_put(old);
5649 
5650 		if (old && !new) {
5651 			static_branch_dec(&generic_xdp_needed_key);
5652 		} else if (new && !old) {
5653 			static_branch_inc(&generic_xdp_needed_key);
5654 			dev_disable_lro(dev);
5655 			dev_disable_gro_hw(dev);
5656 		}
5657 		break;
5658 
5659 	default:
5660 		ret = -EINVAL;
5661 		break;
5662 	}
5663 
5664 	return ret;
5665 }
5666 
netif_receive_skb_internal(struct sk_buff * skb)5667 static int netif_receive_skb_internal(struct sk_buff *skb)
5668 {
5669 	int ret;
5670 
5671 	net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
5672 
5673 	if (skb_defer_rx_timestamp(skb))
5674 		return NET_RX_SUCCESS;
5675 
5676 	rcu_read_lock();
5677 #ifdef CONFIG_RPS
5678 	if (static_branch_unlikely(&rps_needed)) {
5679 		struct rps_dev_flow voidflow, *rflow = &voidflow;
5680 		int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5681 
5682 		if (cpu >= 0) {
5683 			ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5684 			rcu_read_unlock();
5685 			return ret;
5686 		}
5687 	}
5688 #endif
5689 	ret = __netif_receive_skb(skb);
5690 	rcu_read_unlock();
5691 	return ret;
5692 }
5693 
netif_receive_skb_list_internal(struct list_head * head)5694 void netif_receive_skb_list_internal(struct list_head *head)
5695 {
5696 	struct sk_buff *skb, *next;
5697 	struct list_head sublist;
5698 
5699 	INIT_LIST_HEAD(&sublist);
5700 	list_for_each_entry_safe(skb, next, head, list) {
5701 		net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
5702 		skb_list_del_init(skb);
5703 		if (!skb_defer_rx_timestamp(skb))
5704 			list_add_tail(&skb->list, &sublist);
5705 	}
5706 	list_splice_init(&sublist, head);
5707 
5708 	rcu_read_lock();
5709 #ifdef CONFIG_RPS
5710 	if (static_branch_unlikely(&rps_needed)) {
5711 		list_for_each_entry_safe(skb, next, head, list) {
5712 			struct rps_dev_flow voidflow, *rflow = &voidflow;
5713 			int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5714 
5715 			if (cpu >= 0) {
5716 				/* Will be handled, remove from list */
5717 				skb_list_del_init(skb);
5718 				enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5719 			}
5720 		}
5721 	}
5722 #endif
5723 	__netif_receive_skb_list(head);
5724 	rcu_read_unlock();
5725 }
5726 
5727 /**
5728  *	netif_receive_skb - process receive buffer from network
5729  *	@skb: buffer to process
5730  *
5731  *	netif_receive_skb() is the main receive data processing function.
5732  *	It always succeeds. The buffer may be dropped during processing
5733  *	for congestion control or by the protocol layers.
5734  *
5735  *	This function may only be called from softirq context and interrupts
5736  *	should be enabled.
5737  *
5738  *	Return values (usually ignored):
5739  *	NET_RX_SUCCESS: no congestion
5740  *	NET_RX_DROP: packet was dropped
5741  */
netif_receive_skb(struct sk_buff * skb)5742 int netif_receive_skb(struct sk_buff *skb)
5743 {
5744 	int ret;
5745 
5746 	trace_netif_receive_skb_entry(skb);
5747 
5748 	ret = netif_receive_skb_internal(skb);
5749 	trace_netif_receive_skb_exit(ret);
5750 
5751 	return ret;
5752 }
5753 EXPORT_SYMBOL(netif_receive_skb);
5754 
5755 /**
5756  *	netif_receive_skb_list - process many receive buffers from network
5757  *	@head: list of skbs to process.
5758  *
5759  *	Since return value of netif_receive_skb() is normally ignored, and
5760  *	wouldn't be meaningful for a list, this function returns void.
5761  *
5762  *	This function may only be called from softirq context and interrupts
5763  *	should be enabled.
5764  */
netif_receive_skb_list(struct list_head * head)5765 void netif_receive_skb_list(struct list_head *head)
5766 {
5767 	struct sk_buff *skb;
5768 
5769 	if (list_empty(head))
5770 		return;
5771 	if (trace_netif_receive_skb_list_entry_enabled()) {
5772 		list_for_each_entry(skb, head, list)
5773 			trace_netif_receive_skb_list_entry(skb);
5774 	}
5775 	netif_receive_skb_list_internal(head);
5776 	trace_netif_receive_skb_list_exit(0);
5777 }
5778 EXPORT_SYMBOL(netif_receive_skb_list);
5779 
5780 static DEFINE_PER_CPU(struct work_struct, flush_works);
5781 
5782 /* Network device is going away, flush any packets still pending */
flush_backlog(struct work_struct * work)5783 static void flush_backlog(struct work_struct *work)
5784 {
5785 	struct sk_buff *skb, *tmp;
5786 	struct softnet_data *sd;
5787 
5788 	local_bh_disable();
5789 	sd = this_cpu_ptr(&softnet_data);
5790 
5791 	rps_lock_irq_disable(sd);
5792 	skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
5793 		if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5794 			__skb_unlink(skb, &sd->input_pkt_queue);
5795 			dev_kfree_skb_irq(skb);
5796 			input_queue_head_incr(sd);
5797 		}
5798 	}
5799 	rps_unlock_irq_enable(sd);
5800 
5801 	skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
5802 		if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5803 			__skb_unlink(skb, &sd->process_queue);
5804 			kfree_skb(skb);
5805 			input_queue_head_incr(sd);
5806 		}
5807 	}
5808 	local_bh_enable();
5809 }
5810 
flush_required(int cpu)5811 static bool flush_required(int cpu)
5812 {
5813 #if IS_ENABLED(CONFIG_RPS)
5814 	struct softnet_data *sd = &per_cpu(softnet_data, cpu);
5815 	bool do_flush;
5816 
5817 	rps_lock_irq_disable(sd);
5818 
5819 	/* as insertion into process_queue happens with the rps lock held,
5820 	 * process_queue access may race only with dequeue
5821 	 */
5822 	do_flush = !skb_queue_empty(&sd->input_pkt_queue) ||
5823 		   !skb_queue_empty_lockless(&sd->process_queue);
5824 	rps_unlock_irq_enable(sd);
5825 
5826 	return do_flush;
5827 #endif
5828 	/* without RPS we can't safely check input_pkt_queue: during a
5829 	 * concurrent remote skb_queue_splice() we can detect as empty both
5830 	 * input_pkt_queue and process_queue even if the latter could end-up
5831 	 * containing a lot of packets.
5832 	 */
5833 	return true;
5834 }
5835 
flush_all_backlogs(void)5836 static void flush_all_backlogs(void)
5837 {
5838 	static cpumask_t flush_cpus;
5839 	unsigned int cpu;
5840 
5841 	/* since we are under rtnl lock protection we can use static data
5842 	 * for the cpumask and avoid allocating on stack the possibly
5843 	 * large mask
5844 	 */
5845 	ASSERT_RTNL();
5846 
5847 	cpus_read_lock();
5848 
5849 	cpumask_clear(&flush_cpus);
5850 	for_each_online_cpu(cpu) {
5851 		if (flush_required(cpu)) {
5852 			queue_work_on(cpu, system_highpri_wq,
5853 				      per_cpu_ptr(&flush_works, cpu));
5854 			cpumask_set_cpu(cpu, &flush_cpus);
5855 		}
5856 	}
5857 
5858 	/* we can have in flight packet[s] on the cpus we are not flushing,
5859 	 * synchronize_net() in unregister_netdevice_many() will take care of
5860 	 * them
5861 	 */
5862 	for_each_cpu(cpu, &flush_cpus)
5863 		flush_work(per_cpu_ptr(&flush_works, cpu));
5864 
5865 	cpus_read_unlock();
5866 }
5867 
net_rps_send_ipi(struct softnet_data * remsd)5868 static void net_rps_send_ipi(struct softnet_data *remsd)
5869 {
5870 #ifdef CONFIG_RPS
5871 	while (remsd) {
5872 		struct softnet_data *next = remsd->rps_ipi_next;
5873 
5874 		if (cpu_online(remsd->cpu))
5875 			smp_call_function_single_async(remsd->cpu, &remsd->csd);
5876 		remsd = next;
5877 	}
5878 #endif
5879 }
5880 
5881 /*
5882  * net_rps_action_and_irq_enable sends any pending IPI's for rps.
5883  * Note: called with local irq disabled, but exits with local irq enabled.
5884  */
net_rps_action_and_irq_enable(struct softnet_data * sd)5885 static void net_rps_action_and_irq_enable(struct softnet_data *sd)
5886 {
5887 #ifdef CONFIG_RPS
5888 	struct softnet_data *remsd = sd->rps_ipi_list;
5889 
5890 	if (remsd) {
5891 		sd->rps_ipi_list = NULL;
5892 
5893 		local_irq_enable();
5894 
5895 		/* Send pending IPI's to kick RPS processing on remote cpus. */
5896 		net_rps_send_ipi(remsd);
5897 	} else
5898 #endif
5899 		local_irq_enable();
5900 }
5901 
sd_has_rps_ipi_waiting(struct softnet_data * sd)5902 static bool sd_has_rps_ipi_waiting(struct softnet_data *sd)
5903 {
5904 #ifdef CONFIG_RPS
5905 	return sd->rps_ipi_list != NULL;
5906 #else
5907 	return false;
5908 #endif
5909 }
5910 
process_backlog(struct napi_struct * napi,int quota)5911 static int process_backlog(struct napi_struct *napi, int quota)
5912 {
5913 	struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
5914 	bool again = true;
5915 	int work = 0;
5916 
5917 	/* Check if we have pending ipi, its better to send them now,
5918 	 * not waiting net_rx_action() end.
5919 	 */
5920 	if (sd_has_rps_ipi_waiting(sd)) {
5921 		local_irq_disable();
5922 		net_rps_action_and_irq_enable(sd);
5923 	}
5924 
5925 	napi->weight = READ_ONCE(dev_rx_weight);
5926 	while (again) {
5927 		struct sk_buff *skb;
5928 
5929 		while ((skb = __skb_dequeue(&sd->process_queue))) {
5930 			rcu_read_lock();
5931 			__netif_receive_skb(skb);
5932 			rcu_read_unlock();
5933 			input_queue_head_incr(sd);
5934 			if (++work >= quota)
5935 				return work;
5936 
5937 		}
5938 
5939 		rps_lock_irq_disable(sd);
5940 		if (skb_queue_empty(&sd->input_pkt_queue)) {
5941 			/*
5942 			 * Inline a custom version of __napi_complete().
5943 			 * only current cpu owns and manipulates this napi,
5944 			 * and NAPI_STATE_SCHED is the only possible flag set
5945 			 * on backlog.
5946 			 * We can use a plain write instead of clear_bit(),
5947 			 * and we dont need an smp_mb() memory barrier.
5948 			 */
5949 			napi->state = 0;
5950 			again = false;
5951 		} else {
5952 			skb_queue_splice_tail_init(&sd->input_pkt_queue,
5953 						   &sd->process_queue);
5954 		}
5955 		rps_unlock_irq_enable(sd);
5956 	}
5957 
5958 	return work;
5959 }
5960 
5961 /**
5962  * __napi_schedule - schedule for receive
5963  * @n: entry to schedule
5964  *
5965  * The entry's receive function will be scheduled to run.
5966  * Consider using __napi_schedule_irqoff() if hard irqs are masked.
5967  */
__napi_schedule(struct napi_struct * n)5968 void __napi_schedule(struct napi_struct *n)
5969 {
5970 	unsigned long flags;
5971 
5972 	local_irq_save(flags);
5973 	____napi_schedule(this_cpu_ptr(&softnet_data), n);
5974 	local_irq_restore(flags);
5975 }
5976 EXPORT_SYMBOL(__napi_schedule);
5977 
5978 /**
5979  *	napi_schedule_prep - check if napi can be scheduled
5980  *	@n: napi context
5981  *
5982  * Test if NAPI routine is already running, and if not mark
5983  * it as running.  This is used as a condition variable to
5984  * insure only one NAPI poll instance runs.  We also make
5985  * sure there is no pending NAPI disable.
5986  */
napi_schedule_prep(struct napi_struct * n)5987 bool napi_schedule_prep(struct napi_struct *n)
5988 {
5989 	unsigned long val, new;
5990 
5991 	do {
5992 		val = READ_ONCE(n->state);
5993 		if (unlikely(val & NAPIF_STATE_DISABLE))
5994 			return false;
5995 		new = val | NAPIF_STATE_SCHED;
5996 
5997 		/* Sets STATE_MISSED bit if STATE_SCHED was already set
5998 		 * This was suggested by Alexander Duyck, as compiler
5999 		 * emits better code than :
6000 		 * if (val & NAPIF_STATE_SCHED)
6001 		 *     new |= NAPIF_STATE_MISSED;
6002 		 */
6003 		new |= (val & NAPIF_STATE_SCHED) / NAPIF_STATE_SCHED *
6004 						   NAPIF_STATE_MISSED;
6005 	} while (cmpxchg(&n->state, val, new) != val);
6006 
6007 	return !(val & NAPIF_STATE_SCHED);
6008 }
6009 EXPORT_SYMBOL(napi_schedule_prep);
6010 
6011 /**
6012  * __napi_schedule_irqoff - schedule for receive
6013  * @n: entry to schedule
6014  *
6015  * Variant of __napi_schedule() assuming hard irqs are masked.
6016  *
6017  * On PREEMPT_RT enabled kernels this maps to __napi_schedule()
6018  * because the interrupt disabled assumption might not be true
6019  * due to force-threaded interrupts and spinlock substitution.
6020  */
__napi_schedule_irqoff(struct napi_struct * n)6021 void __napi_schedule_irqoff(struct napi_struct *n)
6022 {
6023 	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
6024 		____napi_schedule(this_cpu_ptr(&softnet_data), n);
6025 	else
6026 		__napi_schedule(n);
6027 }
6028 EXPORT_SYMBOL(__napi_schedule_irqoff);
6029 
napi_complete_done(struct napi_struct * n,int work_done)6030 bool napi_complete_done(struct napi_struct *n, int work_done)
6031 {
6032 	unsigned long flags, val, new, timeout = 0;
6033 	bool ret = true;
6034 
6035 	/*
6036 	 * 1) Don't let napi dequeue from the cpu poll list
6037 	 *    just in case its running on a different cpu.
6038 	 * 2) If we are busy polling, do nothing here, we have
6039 	 *    the guarantee we will be called later.
6040 	 */
6041 	if (unlikely(n->state & (NAPIF_STATE_NPSVC |
6042 				 NAPIF_STATE_IN_BUSY_POLL)))
6043 		return false;
6044 
6045 	if (work_done) {
6046 		if (n->gro_bitmask)
6047 			timeout = READ_ONCE(n->dev->gro_flush_timeout);
6048 		n->defer_hard_irqs_count = READ_ONCE(n->dev->napi_defer_hard_irqs);
6049 	}
6050 	if (n->defer_hard_irqs_count > 0) {
6051 		n->defer_hard_irqs_count--;
6052 		timeout = READ_ONCE(n->dev->gro_flush_timeout);
6053 		if (timeout)
6054 			ret = false;
6055 	}
6056 	if (n->gro_bitmask) {
6057 		/* When the NAPI instance uses a timeout and keeps postponing
6058 		 * it, we need to bound somehow the time packets are kept in
6059 		 * the GRO layer
6060 		 */
6061 		napi_gro_flush(n, !!timeout);
6062 	}
6063 
6064 	gro_normal_list(n);
6065 
6066 	if (unlikely(!list_empty(&n->poll_list))) {
6067 		/* If n->poll_list is not empty, we need to mask irqs */
6068 		local_irq_save(flags);
6069 		list_del_init(&n->poll_list);
6070 		local_irq_restore(flags);
6071 	}
6072 
6073 	do {
6074 		val = READ_ONCE(n->state);
6075 
6076 		WARN_ON_ONCE(!(val & NAPIF_STATE_SCHED));
6077 
6078 		new = val & ~(NAPIF_STATE_MISSED | NAPIF_STATE_SCHED |
6079 			      NAPIF_STATE_SCHED_THREADED |
6080 			      NAPIF_STATE_PREFER_BUSY_POLL);
6081 
6082 		/* If STATE_MISSED was set, leave STATE_SCHED set,
6083 		 * because we will call napi->poll() one more time.
6084 		 * This C code was suggested by Alexander Duyck to help gcc.
6085 		 */
6086 		new |= (val & NAPIF_STATE_MISSED) / NAPIF_STATE_MISSED *
6087 						    NAPIF_STATE_SCHED;
6088 	} while (cmpxchg(&n->state, val, new) != val);
6089 
6090 	if (unlikely(val & NAPIF_STATE_MISSED)) {
6091 		__napi_schedule(n);
6092 		return false;
6093 	}
6094 
6095 	if (timeout)
6096 		hrtimer_start(&n->timer, ns_to_ktime(timeout),
6097 			      HRTIMER_MODE_REL_PINNED);
6098 	return ret;
6099 }
6100 EXPORT_SYMBOL(napi_complete_done);
6101 
6102 /* must be called under rcu_read_lock(), as we dont take a reference */
napi_by_id(unsigned int napi_id)6103 static struct napi_struct *napi_by_id(unsigned int napi_id)
6104 {
6105 	unsigned int hash = napi_id % HASH_SIZE(napi_hash);
6106 	struct napi_struct *napi;
6107 
6108 	hlist_for_each_entry_rcu(napi, &napi_hash[hash], napi_hash_node)
6109 		if (napi->napi_id == napi_id)
6110 			return napi;
6111 
6112 	return NULL;
6113 }
6114 
6115 #if defined(CONFIG_NET_RX_BUSY_POLL)
6116 
__busy_poll_stop(struct napi_struct * napi,bool skip_schedule)6117 static void __busy_poll_stop(struct napi_struct *napi, bool skip_schedule)
6118 {
6119 	if (!skip_schedule) {
6120 		gro_normal_list(napi);
6121 		__napi_schedule(napi);
6122 		return;
6123 	}
6124 
6125 	if (napi->gro_bitmask) {
6126 		/* flush too old packets
6127 		 * If HZ < 1000, flush all packets.
6128 		 */
6129 		napi_gro_flush(napi, HZ >= 1000);
6130 	}
6131 
6132 	gro_normal_list(napi);
6133 	clear_bit(NAPI_STATE_SCHED, &napi->state);
6134 }
6135 
busy_poll_stop(struct napi_struct * napi,void * have_poll_lock,bool prefer_busy_poll,u16 budget)6136 static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool prefer_busy_poll,
6137 			   u16 budget)
6138 {
6139 	bool skip_schedule = false;
6140 	unsigned long timeout;
6141 	int rc;
6142 
6143 	/* Busy polling means there is a high chance device driver hard irq
6144 	 * could not grab NAPI_STATE_SCHED, and that NAPI_STATE_MISSED was
6145 	 * set in napi_schedule_prep().
6146 	 * Since we are about to call napi->poll() once more, we can safely
6147 	 * clear NAPI_STATE_MISSED.
6148 	 *
6149 	 * Note: x86 could use a single "lock and ..." instruction
6150 	 * to perform these two clear_bit()
6151 	 */
6152 	clear_bit(NAPI_STATE_MISSED, &napi->state);
6153 	clear_bit(NAPI_STATE_IN_BUSY_POLL, &napi->state);
6154 
6155 	local_bh_disable();
6156 
6157 	if (prefer_busy_poll) {
6158 		napi->defer_hard_irqs_count = READ_ONCE(napi->dev->napi_defer_hard_irqs);
6159 		timeout = READ_ONCE(napi->dev->gro_flush_timeout);
6160 		if (napi->defer_hard_irqs_count && timeout) {
6161 			hrtimer_start(&napi->timer, ns_to_ktime(timeout), HRTIMER_MODE_REL_PINNED);
6162 			skip_schedule = true;
6163 		}
6164 	}
6165 
6166 	/* All we really want here is to re-enable device interrupts.
6167 	 * Ideally, a new ndo_busy_poll_stop() could avoid another round.
6168 	 */
6169 	rc = napi->poll(napi, budget);
6170 	/* We can't gro_normal_list() here, because napi->poll() might have
6171 	 * rearmed the napi (napi_complete_done()) in which case it could
6172 	 * already be running on another CPU.
6173 	 */
6174 	trace_napi_poll(napi, rc, budget);
6175 	netpoll_poll_unlock(have_poll_lock);
6176 	if (rc == budget)
6177 		__busy_poll_stop(napi, skip_schedule);
6178 	local_bh_enable();
6179 }
6180 
napi_busy_loop(unsigned int napi_id,bool (* loop_end)(void *,unsigned long),void * loop_end_arg,bool prefer_busy_poll,u16 budget)6181 void napi_busy_loop(unsigned int napi_id,
6182 		    bool (*loop_end)(void *, unsigned long),
6183 		    void *loop_end_arg, bool prefer_busy_poll, u16 budget)
6184 {
6185 	unsigned long start_time = loop_end ? busy_loop_current_time() : 0;
6186 	int (*napi_poll)(struct napi_struct *napi, int budget);
6187 	void *have_poll_lock = NULL;
6188 	struct napi_struct *napi;
6189 
6190 restart:
6191 	napi_poll = NULL;
6192 
6193 	rcu_read_lock();
6194 
6195 	napi = napi_by_id(napi_id);
6196 	if (!napi)
6197 		goto out;
6198 
6199 	preempt_disable();
6200 	for (;;) {
6201 		int work = 0;
6202 
6203 		local_bh_disable();
6204 		if (!napi_poll) {
6205 			unsigned long val = READ_ONCE(napi->state);
6206 
6207 			/* If multiple threads are competing for this napi,
6208 			 * we avoid dirtying napi->state as much as we can.
6209 			 */
6210 			if (val & (NAPIF_STATE_DISABLE | NAPIF_STATE_SCHED |
6211 				   NAPIF_STATE_IN_BUSY_POLL)) {
6212 				if (prefer_busy_poll)
6213 					set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6214 				goto count;
6215 			}
6216 			if (cmpxchg(&napi->state, val,
6217 				    val | NAPIF_STATE_IN_BUSY_POLL |
6218 					  NAPIF_STATE_SCHED) != val) {
6219 				if (prefer_busy_poll)
6220 					set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6221 				goto count;
6222 			}
6223 			have_poll_lock = netpoll_poll_lock(napi);
6224 			napi_poll = napi->poll;
6225 		}
6226 		work = napi_poll(napi, budget);
6227 		trace_napi_poll(napi, work, budget);
6228 		gro_normal_list(napi);
6229 count:
6230 		if (work > 0)
6231 			__NET_ADD_STATS(dev_net(napi->dev),
6232 					LINUX_MIB_BUSYPOLLRXPACKETS, work);
6233 		local_bh_enable();
6234 
6235 		if (!loop_end || loop_end(loop_end_arg, start_time))
6236 			break;
6237 
6238 		if (unlikely(need_resched())) {
6239 			if (napi_poll)
6240 				busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
6241 			preempt_enable();
6242 			rcu_read_unlock();
6243 			cond_resched();
6244 			if (loop_end(loop_end_arg, start_time))
6245 				return;
6246 			goto restart;
6247 		}
6248 		cpu_relax();
6249 	}
6250 	if (napi_poll)
6251 		busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
6252 	preempt_enable();
6253 out:
6254 	rcu_read_unlock();
6255 }
6256 EXPORT_SYMBOL(napi_busy_loop);
6257 
6258 #endif /* CONFIG_NET_RX_BUSY_POLL */
6259 
napi_hash_add(struct napi_struct * napi)6260 static void napi_hash_add(struct napi_struct *napi)
6261 {
6262 	if (test_bit(NAPI_STATE_NO_BUSY_POLL, &napi->state))
6263 		return;
6264 
6265 	spin_lock(&napi_hash_lock);
6266 
6267 	/* 0..NR_CPUS range is reserved for sender_cpu use */
6268 	do {
6269 		if (unlikely(++napi_gen_id < MIN_NAPI_ID))
6270 			napi_gen_id = MIN_NAPI_ID;
6271 	} while (napi_by_id(napi_gen_id));
6272 	napi->napi_id = napi_gen_id;
6273 
6274 	hlist_add_head_rcu(&napi->napi_hash_node,
6275 			   &napi_hash[napi->napi_id % HASH_SIZE(napi_hash)]);
6276 
6277 	spin_unlock(&napi_hash_lock);
6278 }
6279 
6280 /* Warning : caller is responsible to make sure rcu grace period
6281  * is respected before freeing memory containing @napi
6282  */
napi_hash_del(struct napi_struct * napi)6283 static void napi_hash_del(struct napi_struct *napi)
6284 {
6285 	spin_lock(&napi_hash_lock);
6286 
6287 	hlist_del_init_rcu(&napi->napi_hash_node);
6288 
6289 	spin_unlock(&napi_hash_lock);
6290 }
6291 
napi_watchdog(struct hrtimer * timer)6292 static enum hrtimer_restart napi_watchdog(struct hrtimer *timer)
6293 {
6294 	struct napi_struct *napi;
6295 
6296 	napi = container_of(timer, struct napi_struct, timer);
6297 
6298 	/* Note : we use a relaxed variant of napi_schedule_prep() not setting
6299 	 * NAPI_STATE_MISSED, since we do not react to a device IRQ.
6300 	 */
6301 	if (!napi_disable_pending(napi) &&
6302 	    !test_and_set_bit(NAPI_STATE_SCHED, &napi->state)) {
6303 		clear_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6304 		__napi_schedule_irqoff(napi);
6305 	}
6306 
6307 	return HRTIMER_NORESTART;
6308 }
6309 
init_gro_hash(struct napi_struct * napi)6310 static void init_gro_hash(struct napi_struct *napi)
6311 {
6312 	int i;
6313 
6314 	for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6315 		INIT_LIST_HEAD(&napi->gro_hash[i].list);
6316 		napi->gro_hash[i].count = 0;
6317 	}
6318 	napi->gro_bitmask = 0;
6319 }
6320 
dev_set_threaded(struct net_device * dev,bool threaded)6321 int dev_set_threaded(struct net_device *dev, bool threaded)
6322 {
6323 	struct napi_struct *napi;
6324 	int err = 0;
6325 
6326 	if (dev->threaded == threaded)
6327 		return 0;
6328 
6329 	if (threaded) {
6330 		list_for_each_entry(napi, &dev->napi_list, dev_list) {
6331 			if (!napi->thread) {
6332 				err = napi_kthread_create(napi);
6333 				if (err) {
6334 					threaded = false;
6335 					break;
6336 				}
6337 			}
6338 		}
6339 	}
6340 
6341 	dev->threaded = threaded;
6342 
6343 	/* Make sure kthread is created before THREADED bit
6344 	 * is set.
6345 	 */
6346 	smp_mb__before_atomic();
6347 
6348 	/* Setting/unsetting threaded mode on a napi might not immediately
6349 	 * take effect, if the current napi instance is actively being
6350 	 * polled. In this case, the switch between threaded mode and
6351 	 * softirq mode will happen in the next round of napi_schedule().
6352 	 * This should not cause hiccups/stalls to the live traffic.
6353 	 */
6354 	list_for_each_entry(napi, &dev->napi_list, dev_list) {
6355 		if (threaded)
6356 			set_bit(NAPI_STATE_THREADED, &napi->state);
6357 		else
6358 			clear_bit(NAPI_STATE_THREADED, &napi->state);
6359 	}
6360 
6361 	return err;
6362 }
6363 EXPORT_SYMBOL(dev_set_threaded);
6364 
netif_napi_add_weight(struct net_device * dev,struct napi_struct * napi,int (* poll)(struct napi_struct *,int),int weight)6365 void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi,
6366 			   int (*poll)(struct napi_struct *, int), int weight)
6367 {
6368 	if (WARN_ON(test_and_set_bit(NAPI_STATE_LISTED, &napi->state)))
6369 		return;
6370 
6371 	INIT_LIST_HEAD(&napi->poll_list);
6372 	INIT_HLIST_NODE(&napi->napi_hash_node);
6373 	hrtimer_init(&napi->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
6374 	napi->timer.function = napi_watchdog;
6375 	init_gro_hash(napi);
6376 	napi->skb = NULL;
6377 	INIT_LIST_HEAD(&napi->rx_list);
6378 	napi->rx_count = 0;
6379 	napi->poll = poll;
6380 	if (weight > NAPI_POLL_WEIGHT)
6381 		netdev_err_once(dev, "%s() called with weight %d\n", __func__,
6382 				weight);
6383 	napi->weight = weight;
6384 	napi->dev = dev;
6385 #ifdef CONFIG_NETPOLL
6386 	napi->poll_owner = -1;
6387 #endif
6388 	set_bit(NAPI_STATE_SCHED, &napi->state);
6389 	set_bit(NAPI_STATE_NPSVC, &napi->state);
6390 	list_add_rcu(&napi->dev_list, &dev->napi_list);
6391 	napi_hash_add(napi);
6392 	napi_get_frags_check(napi);
6393 	/* Create kthread for this napi if dev->threaded is set.
6394 	 * Clear dev->threaded if kthread creation failed so that
6395 	 * threaded mode will not be enabled in napi_enable().
6396 	 */
6397 	if (dev->threaded && napi_kthread_create(napi))
6398 		dev->threaded = 0;
6399 }
6400 EXPORT_SYMBOL(netif_napi_add_weight);
6401 
napi_disable(struct napi_struct * n)6402 void napi_disable(struct napi_struct *n)
6403 {
6404 	unsigned long val, new;
6405 
6406 	might_sleep();
6407 	set_bit(NAPI_STATE_DISABLE, &n->state);
6408 
6409 	for ( ; ; ) {
6410 		val = READ_ONCE(n->state);
6411 		if (val & (NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC)) {
6412 			usleep_range(20, 200);
6413 			continue;
6414 		}
6415 
6416 		new = val | NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC;
6417 		new &= ~(NAPIF_STATE_THREADED | NAPIF_STATE_PREFER_BUSY_POLL);
6418 
6419 		if (cmpxchg(&n->state, val, new) == val)
6420 			break;
6421 	}
6422 
6423 	hrtimer_cancel(&n->timer);
6424 
6425 	clear_bit(NAPI_STATE_DISABLE, &n->state);
6426 }
6427 EXPORT_SYMBOL(napi_disable);
6428 
6429 /**
6430  *	napi_enable - enable NAPI scheduling
6431  *	@n: NAPI context
6432  *
6433  * Resume NAPI from being scheduled on this context.
6434  * Must be paired with napi_disable.
6435  */
napi_enable(struct napi_struct * n)6436 void napi_enable(struct napi_struct *n)
6437 {
6438 	unsigned long val, new;
6439 
6440 	do {
6441 		val = READ_ONCE(n->state);
6442 		BUG_ON(!test_bit(NAPI_STATE_SCHED, &val));
6443 
6444 		new = val & ~(NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC);
6445 		if (n->dev->threaded && n->thread)
6446 			new |= NAPIF_STATE_THREADED;
6447 	} while (cmpxchg(&n->state, val, new) != val);
6448 }
6449 EXPORT_SYMBOL(napi_enable);
6450 
flush_gro_hash(struct napi_struct * napi)6451 static void flush_gro_hash(struct napi_struct *napi)
6452 {
6453 	int i;
6454 
6455 	for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6456 		struct sk_buff *skb, *n;
6457 
6458 		list_for_each_entry_safe(skb, n, &napi->gro_hash[i].list, list)
6459 			kfree_skb(skb);
6460 		napi->gro_hash[i].count = 0;
6461 	}
6462 }
6463 
6464 /* Must be called in process context */
__netif_napi_del(struct napi_struct * napi)6465 void __netif_napi_del(struct napi_struct *napi)
6466 {
6467 	if (!test_and_clear_bit(NAPI_STATE_LISTED, &napi->state))
6468 		return;
6469 
6470 	napi_hash_del(napi);
6471 	list_del_rcu(&napi->dev_list);
6472 	napi_free_frags(napi);
6473 
6474 	flush_gro_hash(napi);
6475 	napi->gro_bitmask = 0;
6476 
6477 	if (napi->thread) {
6478 		kthread_stop(napi->thread);
6479 		napi->thread = NULL;
6480 	}
6481 }
6482 EXPORT_SYMBOL(__netif_napi_del);
6483 
__napi_poll(struct napi_struct * n,bool * repoll)6484 static int __napi_poll(struct napi_struct *n, bool *repoll)
6485 {
6486 	int work, weight;
6487 
6488 	weight = n->weight;
6489 
6490 	/* This NAPI_STATE_SCHED test is for avoiding a race
6491 	 * with netpoll's poll_napi().  Only the entity which
6492 	 * obtains the lock and sees NAPI_STATE_SCHED set will
6493 	 * actually make the ->poll() call.  Therefore we avoid
6494 	 * accidentally calling ->poll() when NAPI is not scheduled.
6495 	 */
6496 	work = 0;
6497 	if (test_bit(NAPI_STATE_SCHED, &n->state)) {
6498 		work = n->poll(n, weight);
6499 		trace_napi_poll(n, work, weight);
6500 	}
6501 
6502 	if (unlikely(work > weight))
6503 		netdev_err_once(n->dev, "NAPI poll function %pS returned %d, exceeding its budget of %d.\n",
6504 				n->poll, work, weight);
6505 
6506 	if (likely(work < weight))
6507 		return work;
6508 
6509 	/* Drivers must not modify the NAPI state if they
6510 	 * consume the entire weight.  In such cases this code
6511 	 * still "owns" the NAPI instance and therefore can
6512 	 * move the instance around on the list at-will.
6513 	 */
6514 	if (unlikely(napi_disable_pending(n))) {
6515 		napi_complete(n);
6516 		return work;
6517 	}
6518 
6519 	/* The NAPI context has more processing work, but busy-polling
6520 	 * is preferred. Exit early.
6521 	 */
6522 	if (napi_prefer_busy_poll(n)) {
6523 		if (napi_complete_done(n, work)) {
6524 			/* If timeout is not set, we need to make sure
6525 			 * that the NAPI is re-scheduled.
6526 			 */
6527 			napi_schedule(n);
6528 		}
6529 		return work;
6530 	}
6531 
6532 	if (n->gro_bitmask) {
6533 		/* flush too old packets
6534 		 * If HZ < 1000, flush all packets.
6535 		 */
6536 		napi_gro_flush(n, HZ >= 1000);
6537 	}
6538 
6539 	gro_normal_list(n);
6540 
6541 	/* Some drivers may have called napi_schedule
6542 	 * prior to exhausting their budget.
6543 	 */
6544 	if (unlikely(!list_empty(&n->poll_list))) {
6545 		pr_warn_once("%s: Budget exhausted after napi rescheduled\n",
6546 			     n->dev ? n->dev->name : "backlog");
6547 		return work;
6548 	}
6549 
6550 	*repoll = true;
6551 
6552 	return work;
6553 }
6554 
napi_poll(struct napi_struct * n,struct list_head * repoll)6555 static int napi_poll(struct napi_struct *n, struct list_head *repoll)
6556 {
6557 	bool do_repoll = false;
6558 	void *have;
6559 	int work;
6560 
6561 	list_del_init(&n->poll_list);
6562 
6563 	have = netpoll_poll_lock(n);
6564 
6565 	work = __napi_poll(n, &do_repoll);
6566 
6567 	if (do_repoll)
6568 		list_add_tail(&n->poll_list, repoll);
6569 
6570 	netpoll_poll_unlock(have);
6571 
6572 	return work;
6573 }
6574 
napi_thread_wait(struct napi_struct * napi)6575 static int napi_thread_wait(struct napi_struct *napi)
6576 {
6577 	bool woken = false;
6578 
6579 	set_current_state(TASK_INTERRUPTIBLE);
6580 
6581 	while (!kthread_should_stop()) {
6582 		/* Testing SCHED_THREADED bit here to make sure the current
6583 		 * kthread owns this napi and could poll on this napi.
6584 		 * Testing SCHED bit is not enough because SCHED bit might be
6585 		 * set by some other busy poll thread or by napi_disable().
6586 		 */
6587 		if (test_bit(NAPI_STATE_SCHED_THREADED, &napi->state) || woken) {
6588 			WARN_ON(!list_empty(&napi->poll_list));
6589 			__set_current_state(TASK_RUNNING);
6590 			return 0;
6591 		}
6592 
6593 		schedule();
6594 		/* woken being true indicates this thread owns this napi. */
6595 		woken = true;
6596 		set_current_state(TASK_INTERRUPTIBLE);
6597 	}
6598 	__set_current_state(TASK_RUNNING);
6599 
6600 	return -1;
6601 }
6602 
napi_threaded_poll(void * data)6603 static int napi_threaded_poll(void *data)
6604 {
6605 	struct napi_struct *napi = data;
6606 	void *have;
6607 
6608 	while (!napi_thread_wait(napi)) {
6609 		for (;;) {
6610 			bool repoll = false;
6611 
6612 			local_bh_disable();
6613 
6614 			have = netpoll_poll_lock(napi);
6615 			__napi_poll(napi, &repoll);
6616 			netpoll_poll_unlock(have);
6617 
6618 			local_bh_enable();
6619 
6620 			if (!repoll)
6621 				break;
6622 
6623 			cond_resched();
6624 		}
6625 	}
6626 	return 0;
6627 }
6628 
skb_defer_free_flush(struct softnet_data * sd)6629 static void skb_defer_free_flush(struct softnet_data *sd)
6630 {
6631 	struct sk_buff *skb, *next;
6632 	unsigned long flags;
6633 
6634 	/* Paired with WRITE_ONCE() in skb_attempt_defer_free() */
6635 	if (!READ_ONCE(sd->defer_list))
6636 		return;
6637 
6638 	spin_lock_irqsave(&sd->defer_lock, flags);
6639 	skb = sd->defer_list;
6640 	sd->defer_list = NULL;
6641 	sd->defer_count = 0;
6642 	spin_unlock_irqrestore(&sd->defer_lock, flags);
6643 
6644 	while (skb != NULL) {
6645 		next = skb->next;
6646 		napi_consume_skb(skb, 1);
6647 		skb = next;
6648 	}
6649 }
6650 
net_rx_action(struct softirq_action * h)6651 static __latent_entropy void net_rx_action(struct softirq_action *h)
6652 {
6653 	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
6654 	unsigned long time_limit = jiffies +
6655 		usecs_to_jiffies(READ_ONCE(netdev_budget_usecs));
6656 	int budget = READ_ONCE(netdev_budget);
6657 	LIST_HEAD(list);
6658 	LIST_HEAD(repoll);
6659 
6660 	local_irq_disable();
6661 	list_splice_init(&sd->poll_list, &list);
6662 	local_irq_enable();
6663 
6664 	for (;;) {
6665 		struct napi_struct *n;
6666 
6667 		skb_defer_free_flush(sd);
6668 
6669 		if (list_empty(&list)) {
6670 			if (!sd_has_rps_ipi_waiting(sd) && list_empty(&repoll))
6671 				goto end;
6672 			break;
6673 		}
6674 
6675 		n = list_first_entry(&list, struct napi_struct, poll_list);
6676 		budget -= napi_poll(n, &repoll);
6677 
6678 		/* If softirq window is exhausted then punt.
6679 		 * Allow this to run for 2 jiffies since which will allow
6680 		 * an average latency of 1.5/HZ.
6681 		 */
6682 		if (unlikely(budget <= 0 ||
6683 			     time_after_eq(jiffies, time_limit))) {
6684 			sd->time_squeeze++;
6685 			break;
6686 		}
6687 	}
6688 
6689 	local_irq_disable();
6690 
6691 	list_splice_tail_init(&sd->poll_list, &list);
6692 	list_splice_tail(&repoll, &list);
6693 	list_splice(&list, &sd->poll_list);
6694 	if (!list_empty(&sd->poll_list))
6695 		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
6696 
6697 	net_rps_action_and_irq_enable(sd);
6698 end:;
6699 }
6700 
6701 struct netdev_adjacent {
6702 	struct net_device *dev;
6703 	netdevice_tracker dev_tracker;
6704 
6705 	/* upper master flag, there can only be one master device per list */
6706 	bool master;
6707 
6708 	/* lookup ignore flag */
6709 	bool ignore;
6710 
6711 	/* counter for the number of times this device was added to us */
6712 	u16 ref_nr;
6713 
6714 	/* private field for the users */
6715 	void *private;
6716 
6717 	struct list_head list;
6718 	struct rcu_head rcu;
6719 };
6720 
__netdev_find_adj(struct net_device * adj_dev,struct list_head * adj_list)6721 static struct netdev_adjacent *__netdev_find_adj(struct net_device *adj_dev,
6722 						 struct list_head *adj_list)
6723 {
6724 	struct netdev_adjacent *adj;
6725 
6726 	list_for_each_entry(adj, adj_list, list) {
6727 		if (adj->dev == adj_dev)
6728 			return adj;
6729 	}
6730 	return NULL;
6731 }
6732 
____netdev_has_upper_dev(struct net_device * upper_dev,struct netdev_nested_priv * priv)6733 static int ____netdev_has_upper_dev(struct net_device *upper_dev,
6734 				    struct netdev_nested_priv *priv)
6735 {
6736 	struct net_device *dev = (struct net_device *)priv->data;
6737 
6738 	return upper_dev == dev;
6739 }
6740 
6741 /**
6742  * netdev_has_upper_dev - Check if device is linked to an upper device
6743  * @dev: device
6744  * @upper_dev: upper device to check
6745  *
6746  * Find out if a device is linked to specified upper device and return true
6747  * in case it is. Note that this checks only immediate upper device,
6748  * not through a complete stack of devices. The caller must hold the RTNL lock.
6749  */
netdev_has_upper_dev(struct net_device * dev,struct net_device * upper_dev)6750 bool netdev_has_upper_dev(struct net_device *dev,
6751 			  struct net_device *upper_dev)
6752 {
6753 	struct netdev_nested_priv priv = {
6754 		.data = (void *)upper_dev,
6755 	};
6756 
6757 	ASSERT_RTNL();
6758 
6759 	return netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
6760 					     &priv);
6761 }
6762 EXPORT_SYMBOL(netdev_has_upper_dev);
6763 
6764 /**
6765  * netdev_has_upper_dev_all_rcu - Check if device is linked to an upper device
6766  * @dev: device
6767  * @upper_dev: upper device to check
6768  *
6769  * Find out if a device is linked to specified upper device and return true
6770  * in case it is. Note that this checks the entire upper device chain.
6771  * The caller must hold rcu lock.
6772  */
6773 
netdev_has_upper_dev_all_rcu(struct net_device * dev,struct net_device * upper_dev)6774 bool netdev_has_upper_dev_all_rcu(struct net_device *dev,
6775 				  struct net_device *upper_dev)
6776 {
6777 	struct netdev_nested_priv priv = {
6778 		.data = (void *)upper_dev,
6779 	};
6780 
6781 	return !!netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
6782 					       &priv);
6783 }
6784 EXPORT_SYMBOL(netdev_has_upper_dev_all_rcu);
6785 
6786 /**
6787  * netdev_has_any_upper_dev - Check if device is linked to some device
6788  * @dev: device
6789  *
6790  * Find out if a device is linked to an upper device and return true in case
6791  * it is. The caller must hold the RTNL lock.
6792  */
netdev_has_any_upper_dev(struct net_device * dev)6793 bool netdev_has_any_upper_dev(struct net_device *dev)
6794 {
6795 	ASSERT_RTNL();
6796 
6797 	return !list_empty(&dev->adj_list.upper);
6798 }
6799 EXPORT_SYMBOL(netdev_has_any_upper_dev);
6800 
6801 /**
6802  * netdev_master_upper_dev_get - Get master upper device
6803  * @dev: device
6804  *
6805  * Find a master upper device and return pointer to it or NULL in case
6806  * it's not there. The caller must hold the RTNL lock.
6807  */
netdev_master_upper_dev_get(struct net_device * dev)6808 struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
6809 {
6810 	struct netdev_adjacent *upper;
6811 
6812 	ASSERT_RTNL();
6813 
6814 	if (list_empty(&dev->adj_list.upper))
6815 		return NULL;
6816 
6817 	upper = list_first_entry(&dev->adj_list.upper,
6818 				 struct netdev_adjacent, list);
6819 	if (likely(upper->master))
6820 		return upper->dev;
6821 	return NULL;
6822 }
6823 EXPORT_SYMBOL(netdev_master_upper_dev_get);
6824 
__netdev_master_upper_dev_get(struct net_device * dev)6825 static struct net_device *__netdev_master_upper_dev_get(struct net_device *dev)
6826 {
6827 	struct netdev_adjacent *upper;
6828 
6829 	ASSERT_RTNL();
6830 
6831 	if (list_empty(&dev->adj_list.upper))
6832 		return NULL;
6833 
6834 	upper = list_first_entry(&dev->adj_list.upper,
6835 				 struct netdev_adjacent, list);
6836 	if (likely(upper->master) && !upper->ignore)
6837 		return upper->dev;
6838 	return NULL;
6839 }
6840 
6841 /**
6842  * netdev_has_any_lower_dev - Check if device is linked to some device
6843  * @dev: device
6844  *
6845  * Find out if a device is linked to a lower device and return true in case
6846  * it is. The caller must hold the RTNL lock.
6847  */
netdev_has_any_lower_dev(struct net_device * dev)6848 static bool netdev_has_any_lower_dev(struct net_device *dev)
6849 {
6850 	ASSERT_RTNL();
6851 
6852 	return !list_empty(&dev->adj_list.lower);
6853 }
6854 
netdev_adjacent_get_private(struct list_head * adj_list)6855 void *netdev_adjacent_get_private(struct list_head *adj_list)
6856 {
6857 	struct netdev_adjacent *adj;
6858 
6859 	adj = list_entry(adj_list, struct netdev_adjacent, list);
6860 
6861 	return adj->private;
6862 }
6863 EXPORT_SYMBOL(netdev_adjacent_get_private);
6864 
6865 /**
6866  * netdev_upper_get_next_dev_rcu - Get the next dev from upper list
6867  * @dev: device
6868  * @iter: list_head ** of the current position
6869  *
6870  * Gets the next device from the dev's upper list, starting from iter
6871  * position. The caller must hold RCU read lock.
6872  */
netdev_upper_get_next_dev_rcu(struct net_device * dev,struct list_head ** iter)6873 struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,
6874 						 struct list_head **iter)
6875 {
6876 	struct netdev_adjacent *upper;
6877 
6878 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
6879 
6880 	upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
6881 
6882 	if (&upper->list == &dev->adj_list.upper)
6883 		return NULL;
6884 
6885 	*iter = &upper->list;
6886 
6887 	return upper->dev;
6888 }
6889 EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu);
6890 
__netdev_next_upper_dev(struct net_device * dev,struct list_head ** iter,bool * ignore)6891 static struct net_device *__netdev_next_upper_dev(struct net_device *dev,
6892 						  struct list_head **iter,
6893 						  bool *ignore)
6894 {
6895 	struct netdev_adjacent *upper;
6896 
6897 	upper = list_entry((*iter)->next, struct netdev_adjacent, list);
6898 
6899 	if (&upper->list == &dev->adj_list.upper)
6900 		return NULL;
6901 
6902 	*iter = &upper->list;
6903 	*ignore = upper->ignore;
6904 
6905 	return upper->dev;
6906 }
6907 
netdev_next_upper_dev_rcu(struct net_device * dev,struct list_head ** iter)6908 static struct net_device *netdev_next_upper_dev_rcu(struct net_device *dev,
6909 						    struct list_head **iter)
6910 {
6911 	struct netdev_adjacent *upper;
6912 
6913 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
6914 
6915 	upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
6916 
6917 	if (&upper->list == &dev->adj_list.upper)
6918 		return NULL;
6919 
6920 	*iter = &upper->list;
6921 
6922 	return upper->dev;
6923 }
6924 
__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)6925 static int __netdev_walk_all_upper_dev(struct net_device *dev,
6926 				       int (*fn)(struct net_device *dev,
6927 					 struct netdev_nested_priv *priv),
6928 				       struct netdev_nested_priv *priv)
6929 {
6930 	struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
6931 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
6932 	int ret, cur = 0;
6933 	bool ignore;
6934 
6935 	now = dev;
6936 	iter = &dev->adj_list.upper;
6937 
6938 	while (1) {
6939 		if (now != dev) {
6940 			ret = fn(now, priv);
6941 			if (ret)
6942 				return ret;
6943 		}
6944 
6945 		next = NULL;
6946 		while (1) {
6947 			udev = __netdev_next_upper_dev(now, &iter, &ignore);
6948 			if (!udev)
6949 				break;
6950 			if (ignore)
6951 				continue;
6952 
6953 			next = udev;
6954 			niter = &udev->adj_list.upper;
6955 			dev_stack[cur] = now;
6956 			iter_stack[cur++] = iter;
6957 			break;
6958 		}
6959 
6960 		if (!next) {
6961 			if (!cur)
6962 				return 0;
6963 			next = dev_stack[--cur];
6964 			niter = iter_stack[cur];
6965 		}
6966 
6967 		now = next;
6968 		iter = niter;
6969 	}
6970 
6971 	return 0;
6972 }
6973 
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)6974 int netdev_walk_all_upper_dev_rcu(struct net_device *dev,
6975 				  int (*fn)(struct net_device *dev,
6976 					    struct netdev_nested_priv *priv),
6977 				  struct netdev_nested_priv *priv)
6978 {
6979 	struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
6980 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
6981 	int ret, cur = 0;
6982 
6983 	now = dev;
6984 	iter = &dev->adj_list.upper;
6985 
6986 	while (1) {
6987 		if (now != dev) {
6988 			ret = fn(now, priv);
6989 			if (ret)
6990 				return ret;
6991 		}
6992 
6993 		next = NULL;
6994 		while (1) {
6995 			udev = netdev_next_upper_dev_rcu(now, &iter);
6996 			if (!udev)
6997 				break;
6998 
6999 			next = udev;
7000 			niter = &udev->adj_list.upper;
7001 			dev_stack[cur] = now;
7002 			iter_stack[cur++] = iter;
7003 			break;
7004 		}
7005 
7006 		if (!next) {
7007 			if (!cur)
7008 				return 0;
7009 			next = dev_stack[--cur];
7010 			niter = iter_stack[cur];
7011 		}
7012 
7013 		now = next;
7014 		iter = niter;
7015 	}
7016 
7017 	return 0;
7018 }
7019 EXPORT_SYMBOL_GPL(netdev_walk_all_upper_dev_rcu);
7020 
__netdev_has_upper_dev(struct net_device * dev,struct net_device * upper_dev)7021 static bool __netdev_has_upper_dev(struct net_device *dev,
7022 				   struct net_device *upper_dev)
7023 {
7024 	struct netdev_nested_priv priv = {
7025 		.flags = 0,
7026 		.data = (void *)upper_dev,
7027 	};
7028 
7029 	ASSERT_RTNL();
7030 
7031 	return __netdev_walk_all_upper_dev(dev, ____netdev_has_upper_dev,
7032 					   &priv);
7033 }
7034 
7035 /**
7036  * netdev_lower_get_next_private - Get the next ->private from the
7037  *				   lower neighbour list
7038  * @dev: device
7039  * @iter: list_head ** of the current position
7040  *
7041  * Gets the next netdev_adjacent->private from the dev's lower neighbour
7042  * list, starting from iter position. The caller must hold either hold the
7043  * RTNL lock or its own locking that guarantees that the neighbour lower
7044  * list will remain unchanged.
7045  */
netdev_lower_get_next_private(struct net_device * dev,struct list_head ** iter)7046 void *netdev_lower_get_next_private(struct net_device *dev,
7047 				    struct list_head **iter)
7048 {
7049 	struct netdev_adjacent *lower;
7050 
7051 	lower = list_entry(*iter, struct netdev_adjacent, list);
7052 
7053 	if (&lower->list == &dev->adj_list.lower)
7054 		return NULL;
7055 
7056 	*iter = lower->list.next;
7057 
7058 	return lower->private;
7059 }
7060 EXPORT_SYMBOL(netdev_lower_get_next_private);
7061 
7062 /**
7063  * netdev_lower_get_next_private_rcu - Get the next ->private from the
7064  *				       lower neighbour list, RCU
7065  *				       variant
7066  * @dev: device
7067  * @iter: list_head ** of the current position
7068  *
7069  * Gets the next netdev_adjacent->private from the dev's lower neighbour
7070  * list, starting from iter position. The caller must hold RCU read lock.
7071  */
netdev_lower_get_next_private_rcu(struct net_device * dev,struct list_head ** iter)7072 void *netdev_lower_get_next_private_rcu(struct net_device *dev,
7073 					struct list_head **iter)
7074 {
7075 	struct netdev_adjacent *lower;
7076 
7077 	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
7078 
7079 	lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7080 
7081 	if (&lower->list == &dev->adj_list.lower)
7082 		return NULL;
7083 
7084 	*iter = &lower->list;
7085 
7086 	return lower->private;
7087 }
7088 EXPORT_SYMBOL(netdev_lower_get_next_private_rcu);
7089 
7090 /**
7091  * netdev_lower_get_next - Get the next device from the lower neighbour
7092  *                         list
7093  * @dev: device
7094  * @iter: list_head ** of the current position
7095  *
7096  * Gets the next netdev_adjacent from the dev's lower neighbour
7097  * list, starting from iter position. The caller must hold RTNL lock or
7098  * its own locking that guarantees that the neighbour lower
7099  * list will remain unchanged.
7100  */
netdev_lower_get_next(struct net_device * dev,struct list_head ** iter)7101 void *netdev_lower_get_next(struct net_device *dev, struct list_head **iter)
7102 {
7103 	struct netdev_adjacent *lower;
7104 
7105 	lower = list_entry(*iter, struct netdev_adjacent, list);
7106 
7107 	if (&lower->list == &dev->adj_list.lower)
7108 		return NULL;
7109 
7110 	*iter = lower->list.next;
7111 
7112 	return lower->dev;
7113 }
7114 EXPORT_SYMBOL(netdev_lower_get_next);
7115 
netdev_next_lower_dev(struct net_device * dev,struct list_head ** iter)7116 static struct net_device *netdev_next_lower_dev(struct net_device *dev,
7117 						struct list_head **iter)
7118 {
7119 	struct netdev_adjacent *lower;
7120 
7121 	lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7122 
7123 	if (&lower->list == &dev->adj_list.lower)
7124 		return NULL;
7125 
7126 	*iter = &lower->list;
7127 
7128 	return lower->dev;
7129 }
7130 
__netdev_next_lower_dev(struct net_device * dev,struct list_head ** iter,bool * ignore)7131 static struct net_device *__netdev_next_lower_dev(struct net_device *dev,
7132 						  struct list_head **iter,
7133 						  bool *ignore)
7134 {
7135 	struct netdev_adjacent *lower;
7136 
7137 	lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7138 
7139 	if (&lower->list == &dev->adj_list.lower)
7140 		return NULL;
7141 
7142 	*iter = &lower->list;
7143 	*ignore = lower->ignore;
7144 
7145 	return lower->dev;
7146 }
7147 
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)7148 int netdev_walk_all_lower_dev(struct net_device *dev,
7149 			      int (*fn)(struct net_device *dev,
7150 					struct netdev_nested_priv *priv),
7151 			      struct netdev_nested_priv *priv)
7152 {
7153 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7154 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7155 	int ret, cur = 0;
7156 
7157 	now = dev;
7158 	iter = &dev->adj_list.lower;
7159 
7160 	while (1) {
7161 		if (now != dev) {
7162 			ret = fn(now, priv);
7163 			if (ret)
7164 				return ret;
7165 		}
7166 
7167 		next = NULL;
7168 		while (1) {
7169 			ldev = netdev_next_lower_dev(now, &iter);
7170 			if (!ldev)
7171 				break;
7172 
7173 			next = ldev;
7174 			niter = &ldev->adj_list.lower;
7175 			dev_stack[cur] = now;
7176 			iter_stack[cur++] = iter;
7177 			break;
7178 		}
7179 
7180 		if (!next) {
7181 			if (!cur)
7182 				return 0;
7183 			next = dev_stack[--cur];
7184 			niter = iter_stack[cur];
7185 		}
7186 
7187 		now = next;
7188 		iter = niter;
7189 	}
7190 
7191 	return 0;
7192 }
7193 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev);
7194 
__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)7195 static int __netdev_walk_all_lower_dev(struct net_device *dev,
7196 				       int (*fn)(struct net_device *dev,
7197 					 struct netdev_nested_priv *priv),
7198 				       struct netdev_nested_priv *priv)
7199 {
7200 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7201 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7202 	int ret, cur = 0;
7203 	bool ignore;
7204 
7205 	now = dev;
7206 	iter = &dev->adj_list.lower;
7207 
7208 	while (1) {
7209 		if (now != dev) {
7210 			ret = fn(now, priv);
7211 			if (ret)
7212 				return ret;
7213 		}
7214 
7215 		next = NULL;
7216 		while (1) {
7217 			ldev = __netdev_next_lower_dev(now, &iter, &ignore);
7218 			if (!ldev)
7219 				break;
7220 			if (ignore)
7221 				continue;
7222 
7223 			next = ldev;
7224 			niter = &ldev->adj_list.lower;
7225 			dev_stack[cur] = now;
7226 			iter_stack[cur++] = iter;
7227 			break;
7228 		}
7229 
7230 		if (!next) {
7231 			if (!cur)
7232 				return 0;
7233 			next = dev_stack[--cur];
7234 			niter = iter_stack[cur];
7235 		}
7236 
7237 		now = next;
7238 		iter = niter;
7239 	}
7240 
7241 	return 0;
7242 }
7243 
netdev_next_lower_dev_rcu(struct net_device * dev,struct list_head ** iter)7244 struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
7245 					     struct list_head **iter)
7246 {
7247 	struct netdev_adjacent *lower;
7248 
7249 	lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7250 	if (&lower->list == &dev->adj_list.lower)
7251 		return NULL;
7252 
7253 	*iter = &lower->list;
7254 
7255 	return lower->dev;
7256 }
7257 EXPORT_SYMBOL(netdev_next_lower_dev_rcu);
7258 
__netdev_upper_depth(struct net_device * dev)7259 static u8 __netdev_upper_depth(struct net_device *dev)
7260 {
7261 	struct net_device *udev;
7262 	struct list_head *iter;
7263 	u8 max_depth = 0;
7264 	bool ignore;
7265 
7266 	for (iter = &dev->adj_list.upper,
7267 	     udev = __netdev_next_upper_dev(dev, &iter, &ignore);
7268 	     udev;
7269 	     udev = __netdev_next_upper_dev(dev, &iter, &ignore)) {
7270 		if (ignore)
7271 			continue;
7272 		if (max_depth < udev->upper_level)
7273 			max_depth = udev->upper_level;
7274 	}
7275 
7276 	return max_depth;
7277 }
7278 
__netdev_lower_depth(struct net_device * dev)7279 static u8 __netdev_lower_depth(struct net_device *dev)
7280 {
7281 	struct net_device *ldev;
7282 	struct list_head *iter;
7283 	u8 max_depth = 0;
7284 	bool ignore;
7285 
7286 	for (iter = &dev->adj_list.lower,
7287 	     ldev = __netdev_next_lower_dev(dev, &iter, &ignore);
7288 	     ldev;
7289 	     ldev = __netdev_next_lower_dev(dev, &iter, &ignore)) {
7290 		if (ignore)
7291 			continue;
7292 		if (max_depth < ldev->lower_level)
7293 			max_depth = ldev->lower_level;
7294 	}
7295 
7296 	return max_depth;
7297 }
7298 
__netdev_update_upper_level(struct net_device * dev,struct netdev_nested_priv * __unused)7299 static int __netdev_update_upper_level(struct net_device *dev,
7300 				       struct netdev_nested_priv *__unused)
7301 {
7302 	dev->upper_level = __netdev_upper_depth(dev) + 1;
7303 	return 0;
7304 }
7305 
7306 #ifdef CONFIG_LOCKDEP
7307 static LIST_HEAD(net_unlink_list);
7308 
net_unlink_todo(struct net_device * dev)7309 static void net_unlink_todo(struct net_device *dev)
7310 {
7311 	if (list_empty(&dev->unlink_list))
7312 		list_add_tail(&dev->unlink_list, &net_unlink_list);
7313 }
7314 #endif
7315 
__netdev_update_lower_level(struct net_device * dev,struct netdev_nested_priv * priv)7316 static int __netdev_update_lower_level(struct net_device *dev,
7317 				       struct netdev_nested_priv *priv)
7318 {
7319 	dev->lower_level = __netdev_lower_depth(dev) + 1;
7320 
7321 #ifdef CONFIG_LOCKDEP
7322 	if (!priv)
7323 		return 0;
7324 
7325 	if (priv->flags & NESTED_SYNC_IMM)
7326 		dev->nested_level = dev->lower_level - 1;
7327 	if (priv->flags & NESTED_SYNC_TODO)
7328 		net_unlink_todo(dev);
7329 #endif
7330 	return 0;
7331 }
7332 
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)7333 int netdev_walk_all_lower_dev_rcu(struct net_device *dev,
7334 				  int (*fn)(struct net_device *dev,
7335 					    struct netdev_nested_priv *priv),
7336 				  struct netdev_nested_priv *priv)
7337 {
7338 	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7339 	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7340 	int ret, cur = 0;
7341 
7342 	now = dev;
7343 	iter = &dev->adj_list.lower;
7344 
7345 	while (1) {
7346 		if (now != dev) {
7347 			ret = fn(now, priv);
7348 			if (ret)
7349 				return ret;
7350 		}
7351 
7352 		next = NULL;
7353 		while (1) {
7354 			ldev = netdev_next_lower_dev_rcu(now, &iter);
7355 			if (!ldev)
7356 				break;
7357 
7358 			next = ldev;
7359 			niter = &ldev->adj_list.lower;
7360 			dev_stack[cur] = now;
7361 			iter_stack[cur++] = iter;
7362 			break;
7363 		}
7364 
7365 		if (!next) {
7366 			if (!cur)
7367 				return 0;
7368 			next = dev_stack[--cur];
7369 			niter = iter_stack[cur];
7370 		}
7371 
7372 		now = next;
7373 		iter = niter;
7374 	}
7375 
7376 	return 0;
7377 }
7378 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev_rcu);
7379 
7380 /**
7381  * netdev_lower_get_first_private_rcu - Get the first ->private from the
7382  *				       lower neighbour list, RCU
7383  *				       variant
7384  * @dev: device
7385  *
7386  * Gets the first netdev_adjacent->private from the dev's lower neighbour
7387  * list. The caller must hold RCU read lock.
7388  */
netdev_lower_get_first_private_rcu(struct net_device * dev)7389 void *netdev_lower_get_first_private_rcu(struct net_device *dev)
7390 {
7391 	struct netdev_adjacent *lower;
7392 
7393 	lower = list_first_or_null_rcu(&dev->adj_list.lower,
7394 			struct netdev_adjacent, list);
7395 	if (lower)
7396 		return lower->private;
7397 	return NULL;
7398 }
7399 EXPORT_SYMBOL(netdev_lower_get_first_private_rcu);
7400 
7401 /**
7402  * netdev_master_upper_dev_get_rcu - Get master upper device
7403  * @dev: device
7404  *
7405  * Find a master upper device and return pointer to it or NULL in case
7406  * it's not there. The caller must hold the RCU read lock.
7407  */
netdev_master_upper_dev_get_rcu(struct net_device * dev)7408 struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev)
7409 {
7410 	struct netdev_adjacent *upper;
7411 
7412 	upper = list_first_or_null_rcu(&dev->adj_list.upper,
7413 				       struct netdev_adjacent, list);
7414 	if (upper && likely(upper->master))
7415 		return upper->dev;
7416 	return NULL;
7417 }
7418 EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);
7419 
netdev_adjacent_sysfs_add(struct net_device * dev,struct net_device * adj_dev,struct list_head * dev_list)7420 static int netdev_adjacent_sysfs_add(struct net_device *dev,
7421 			      struct net_device *adj_dev,
7422 			      struct list_head *dev_list)
7423 {
7424 	char linkname[IFNAMSIZ+7];
7425 
7426 	sprintf(linkname, dev_list == &dev->adj_list.upper ?
7427 		"upper_%s" : "lower_%s", adj_dev->name);
7428 	return sysfs_create_link(&(dev->dev.kobj), &(adj_dev->dev.kobj),
7429 				 linkname);
7430 }
netdev_adjacent_sysfs_del(struct net_device * dev,char * name,struct list_head * dev_list)7431 static void netdev_adjacent_sysfs_del(struct net_device *dev,
7432 			       char *name,
7433 			       struct list_head *dev_list)
7434 {
7435 	char linkname[IFNAMSIZ+7];
7436 
7437 	sprintf(linkname, dev_list == &dev->adj_list.upper ?
7438 		"upper_%s" : "lower_%s", name);
7439 	sysfs_remove_link(&(dev->dev.kobj), linkname);
7440 }
7441 
netdev_adjacent_is_neigh_list(struct net_device * dev,struct net_device * adj_dev,struct list_head * dev_list)7442 static inline bool netdev_adjacent_is_neigh_list(struct net_device *dev,
7443 						 struct net_device *adj_dev,
7444 						 struct list_head *dev_list)
7445 {
7446 	return (dev_list == &dev->adj_list.upper ||
7447 		dev_list == &dev->adj_list.lower) &&
7448 		net_eq(dev_net(dev), dev_net(adj_dev));
7449 }
7450 
__netdev_adjacent_dev_insert(struct net_device * dev,struct net_device * adj_dev,struct list_head * dev_list,void * private,bool master)7451 static int __netdev_adjacent_dev_insert(struct net_device *dev,
7452 					struct net_device *adj_dev,
7453 					struct list_head *dev_list,
7454 					void *private, bool master)
7455 {
7456 	struct netdev_adjacent *adj;
7457 	int ret;
7458 
7459 	adj = __netdev_find_adj(adj_dev, dev_list);
7460 
7461 	if (adj) {
7462 		adj->ref_nr += 1;
7463 		pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d\n",
7464 			 dev->name, adj_dev->name, adj->ref_nr);
7465 
7466 		return 0;
7467 	}
7468 
7469 	adj = kmalloc(sizeof(*adj), GFP_KERNEL);
7470 	if (!adj)
7471 		return -ENOMEM;
7472 
7473 	adj->dev = adj_dev;
7474 	adj->master = master;
7475 	adj->ref_nr = 1;
7476 	adj->private = private;
7477 	adj->ignore = false;
7478 	netdev_hold(adj_dev, &adj->dev_tracker, GFP_KERNEL);
7479 
7480 	pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d; dev_hold on %s\n",
7481 		 dev->name, adj_dev->name, adj->ref_nr, adj_dev->name);
7482 
7483 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list)) {
7484 		ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list);
7485 		if (ret)
7486 			goto free_adj;
7487 	}
7488 
7489 	/* Ensure that master link is always the first item in list. */
7490 	if (master) {
7491 		ret = sysfs_create_link(&(dev->dev.kobj),
7492 					&(adj_dev->dev.kobj), "master");
7493 		if (ret)
7494 			goto remove_symlinks;
7495 
7496 		list_add_rcu(&adj->list, dev_list);
7497 	} else {
7498 		list_add_tail_rcu(&adj->list, dev_list);
7499 	}
7500 
7501 	return 0;
7502 
7503 remove_symlinks:
7504 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
7505 		netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
7506 free_adj:
7507 	netdev_put(adj_dev, &adj->dev_tracker);
7508 	kfree(adj);
7509 
7510 	return ret;
7511 }
7512 
__netdev_adjacent_dev_remove(struct net_device * dev,struct net_device * adj_dev,u16 ref_nr,struct list_head * dev_list)7513 static void __netdev_adjacent_dev_remove(struct net_device *dev,
7514 					 struct net_device *adj_dev,
7515 					 u16 ref_nr,
7516 					 struct list_head *dev_list)
7517 {
7518 	struct netdev_adjacent *adj;
7519 
7520 	pr_debug("Remove adjacency: dev %s adj_dev %s ref_nr %d\n",
7521 		 dev->name, adj_dev->name, ref_nr);
7522 
7523 	adj = __netdev_find_adj(adj_dev, dev_list);
7524 
7525 	if (!adj) {
7526 		pr_err("Adjacency does not exist for device %s from %s\n",
7527 		       dev->name, adj_dev->name);
7528 		WARN_ON(1);
7529 		return;
7530 	}
7531 
7532 	if (adj->ref_nr > ref_nr) {
7533 		pr_debug("adjacency: %s to %s ref_nr - %d = %d\n",
7534 			 dev->name, adj_dev->name, ref_nr,
7535 			 adj->ref_nr - ref_nr);
7536 		adj->ref_nr -= ref_nr;
7537 		return;
7538 	}
7539 
7540 	if (adj->master)
7541 		sysfs_remove_link(&(dev->dev.kobj), "master");
7542 
7543 	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
7544 		netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
7545 
7546 	list_del_rcu(&adj->list);
7547 	pr_debug("adjacency: dev_put for %s, because link removed from %s to %s\n",
7548 		 adj_dev->name, dev->name, adj_dev->name);
7549 	netdev_put(adj_dev, &adj->dev_tracker);
7550 	kfree_rcu(adj, rcu);
7551 }
7552 
__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)7553 static int __netdev_adjacent_dev_link_lists(struct net_device *dev,
7554 					    struct net_device *upper_dev,
7555 					    struct list_head *up_list,
7556 					    struct list_head *down_list,
7557 					    void *private, bool master)
7558 {
7559 	int ret;
7560 
7561 	ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list,
7562 					   private, master);
7563 	if (ret)
7564 		return ret;
7565 
7566 	ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list,
7567 					   private, false);
7568 	if (ret) {
7569 		__netdev_adjacent_dev_remove(dev, upper_dev, 1, up_list);
7570 		return ret;
7571 	}
7572 
7573 	return 0;
7574 }
7575 
__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)7576 static void __netdev_adjacent_dev_unlink_lists(struct net_device *dev,
7577 					       struct net_device *upper_dev,
7578 					       u16 ref_nr,
7579 					       struct list_head *up_list,
7580 					       struct list_head *down_list)
7581 {
7582 	__netdev_adjacent_dev_remove(dev, upper_dev, ref_nr, up_list);
7583 	__netdev_adjacent_dev_remove(upper_dev, dev, ref_nr, down_list);
7584 }
7585 
__netdev_adjacent_dev_link_neighbour(struct net_device * dev,struct net_device * upper_dev,void * private,bool master)7586 static int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
7587 						struct net_device *upper_dev,
7588 						void *private, bool master)
7589 {
7590 	return __netdev_adjacent_dev_link_lists(dev, upper_dev,
7591 						&dev->adj_list.upper,
7592 						&upper_dev->adj_list.lower,
7593 						private, master);
7594 }
7595 
__netdev_adjacent_dev_unlink_neighbour(struct net_device * dev,struct net_device * upper_dev)7596 static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
7597 						   struct net_device *upper_dev)
7598 {
7599 	__netdev_adjacent_dev_unlink_lists(dev, upper_dev, 1,
7600 					   &dev->adj_list.upper,
7601 					   &upper_dev->adj_list.lower);
7602 }
7603 
__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)7604 static int __netdev_upper_dev_link(struct net_device *dev,
7605 				   struct net_device *upper_dev, bool master,
7606 				   void *upper_priv, void *upper_info,
7607 				   struct netdev_nested_priv *priv,
7608 				   struct netlink_ext_ack *extack)
7609 {
7610 	struct netdev_notifier_changeupper_info changeupper_info = {
7611 		.info = {
7612 			.dev = dev,
7613 			.extack = extack,
7614 		},
7615 		.upper_dev = upper_dev,
7616 		.master = master,
7617 		.linking = true,
7618 		.upper_info = upper_info,
7619 	};
7620 	struct net_device *master_dev;
7621 	int ret = 0;
7622 
7623 	ASSERT_RTNL();
7624 
7625 	if (dev == upper_dev)
7626 		return -EBUSY;
7627 
7628 	/* To prevent loops, check if dev is not upper device to upper_dev. */
7629 	if (__netdev_has_upper_dev(upper_dev, dev))
7630 		return -EBUSY;
7631 
7632 	if ((dev->lower_level + upper_dev->upper_level) > MAX_NEST_DEV)
7633 		return -EMLINK;
7634 
7635 	if (!master) {
7636 		if (__netdev_has_upper_dev(dev, upper_dev))
7637 			return -EEXIST;
7638 	} else {
7639 		master_dev = __netdev_master_upper_dev_get(dev);
7640 		if (master_dev)
7641 			return master_dev == upper_dev ? -EEXIST : -EBUSY;
7642 	}
7643 
7644 	ret = call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
7645 					    &changeupper_info.info);
7646 	ret = notifier_to_errno(ret);
7647 	if (ret)
7648 		return ret;
7649 
7650 	ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, upper_priv,
7651 						   master);
7652 	if (ret)
7653 		return ret;
7654 
7655 	ret = call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
7656 					    &changeupper_info.info);
7657 	ret = notifier_to_errno(ret);
7658 	if (ret)
7659 		goto rollback;
7660 
7661 	__netdev_update_upper_level(dev, NULL);
7662 	__netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
7663 
7664 	__netdev_update_lower_level(upper_dev, priv);
7665 	__netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
7666 				    priv);
7667 
7668 	return 0;
7669 
7670 rollback:
7671 	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
7672 
7673 	return ret;
7674 }
7675 
7676 /**
7677  * netdev_upper_dev_link - Add a link to the upper device
7678  * @dev: device
7679  * @upper_dev: new upper device
7680  * @extack: netlink extended ack
7681  *
7682  * Adds a link to device which is upper to this one. The caller must hold
7683  * the RTNL lock. On a failure a negative errno code is returned.
7684  * On success the reference counts are adjusted and the function
7685  * returns zero.
7686  */
netdev_upper_dev_link(struct net_device * dev,struct net_device * upper_dev,struct netlink_ext_ack * extack)7687 int netdev_upper_dev_link(struct net_device *dev,
7688 			  struct net_device *upper_dev,
7689 			  struct netlink_ext_ack *extack)
7690 {
7691 	struct netdev_nested_priv priv = {
7692 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7693 		.data = NULL,
7694 	};
7695 
7696 	return __netdev_upper_dev_link(dev, upper_dev, false,
7697 				       NULL, NULL, &priv, extack);
7698 }
7699 EXPORT_SYMBOL(netdev_upper_dev_link);
7700 
7701 /**
7702  * netdev_master_upper_dev_link - Add a master link to the upper device
7703  * @dev: device
7704  * @upper_dev: new upper device
7705  * @upper_priv: upper device private
7706  * @upper_info: upper info to be passed down via notifier
7707  * @extack: netlink extended ack
7708  *
7709  * Adds a link to device which is upper to this one. In this case, only
7710  * one master upper device can be linked, although other non-master devices
7711  * might be linked as well. The caller must hold the RTNL lock.
7712  * On a failure a negative errno code is returned. On success the reference
7713  * counts are adjusted and the function returns zero.
7714  */
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)7715 int netdev_master_upper_dev_link(struct net_device *dev,
7716 				 struct net_device *upper_dev,
7717 				 void *upper_priv, void *upper_info,
7718 				 struct netlink_ext_ack *extack)
7719 {
7720 	struct netdev_nested_priv priv = {
7721 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7722 		.data = NULL,
7723 	};
7724 
7725 	return __netdev_upper_dev_link(dev, upper_dev, true,
7726 				       upper_priv, upper_info, &priv, extack);
7727 }
7728 EXPORT_SYMBOL(netdev_master_upper_dev_link);
7729 
__netdev_upper_dev_unlink(struct net_device * dev,struct net_device * upper_dev,struct netdev_nested_priv * priv)7730 static void __netdev_upper_dev_unlink(struct net_device *dev,
7731 				      struct net_device *upper_dev,
7732 				      struct netdev_nested_priv *priv)
7733 {
7734 	struct netdev_notifier_changeupper_info changeupper_info = {
7735 		.info = {
7736 			.dev = dev,
7737 		},
7738 		.upper_dev = upper_dev,
7739 		.linking = false,
7740 	};
7741 
7742 	ASSERT_RTNL();
7743 
7744 	changeupper_info.master = netdev_master_upper_dev_get(dev) == upper_dev;
7745 
7746 	call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
7747 				      &changeupper_info.info);
7748 
7749 	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
7750 
7751 	call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
7752 				      &changeupper_info.info);
7753 
7754 	__netdev_update_upper_level(dev, NULL);
7755 	__netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
7756 
7757 	__netdev_update_lower_level(upper_dev, priv);
7758 	__netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
7759 				    priv);
7760 }
7761 
7762 /**
7763  * netdev_upper_dev_unlink - Removes a link to upper device
7764  * @dev: device
7765  * @upper_dev: new upper device
7766  *
7767  * Removes a link to device which is upper to this one. The caller must hold
7768  * the RTNL lock.
7769  */
netdev_upper_dev_unlink(struct net_device * dev,struct net_device * upper_dev)7770 void netdev_upper_dev_unlink(struct net_device *dev,
7771 			     struct net_device *upper_dev)
7772 {
7773 	struct netdev_nested_priv priv = {
7774 		.flags = NESTED_SYNC_TODO,
7775 		.data = NULL,
7776 	};
7777 
7778 	__netdev_upper_dev_unlink(dev, upper_dev, &priv);
7779 }
7780 EXPORT_SYMBOL(netdev_upper_dev_unlink);
7781 
__netdev_adjacent_dev_set(struct net_device * upper_dev,struct net_device * lower_dev,bool val)7782 static void __netdev_adjacent_dev_set(struct net_device *upper_dev,
7783 				      struct net_device *lower_dev,
7784 				      bool val)
7785 {
7786 	struct netdev_adjacent *adj;
7787 
7788 	adj = __netdev_find_adj(lower_dev, &upper_dev->adj_list.lower);
7789 	if (adj)
7790 		adj->ignore = val;
7791 
7792 	adj = __netdev_find_adj(upper_dev, &lower_dev->adj_list.upper);
7793 	if (adj)
7794 		adj->ignore = val;
7795 }
7796 
netdev_adjacent_dev_disable(struct net_device * upper_dev,struct net_device * lower_dev)7797 static void netdev_adjacent_dev_disable(struct net_device *upper_dev,
7798 					struct net_device *lower_dev)
7799 {
7800 	__netdev_adjacent_dev_set(upper_dev, lower_dev, true);
7801 }
7802 
netdev_adjacent_dev_enable(struct net_device * upper_dev,struct net_device * lower_dev)7803 static void netdev_adjacent_dev_enable(struct net_device *upper_dev,
7804 				       struct net_device *lower_dev)
7805 {
7806 	__netdev_adjacent_dev_set(upper_dev, lower_dev, false);
7807 }
7808 
netdev_adjacent_change_prepare(struct net_device * old_dev,struct net_device * new_dev,struct net_device * dev,struct netlink_ext_ack * extack)7809 int netdev_adjacent_change_prepare(struct net_device *old_dev,
7810 				   struct net_device *new_dev,
7811 				   struct net_device *dev,
7812 				   struct netlink_ext_ack *extack)
7813 {
7814 	struct netdev_nested_priv priv = {
7815 		.flags = 0,
7816 		.data = NULL,
7817 	};
7818 	int err;
7819 
7820 	if (!new_dev)
7821 		return 0;
7822 
7823 	if (old_dev && new_dev != old_dev)
7824 		netdev_adjacent_dev_disable(dev, old_dev);
7825 	err = __netdev_upper_dev_link(new_dev, dev, false, NULL, NULL, &priv,
7826 				      extack);
7827 	if (err) {
7828 		if (old_dev && new_dev != old_dev)
7829 			netdev_adjacent_dev_enable(dev, old_dev);
7830 		return err;
7831 	}
7832 
7833 	return 0;
7834 }
7835 EXPORT_SYMBOL(netdev_adjacent_change_prepare);
7836 
netdev_adjacent_change_commit(struct net_device * old_dev,struct net_device * new_dev,struct net_device * dev)7837 void netdev_adjacent_change_commit(struct net_device *old_dev,
7838 				   struct net_device *new_dev,
7839 				   struct net_device *dev)
7840 {
7841 	struct netdev_nested_priv priv = {
7842 		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7843 		.data = NULL,
7844 	};
7845 
7846 	if (!new_dev || !old_dev)
7847 		return;
7848 
7849 	if (new_dev == old_dev)
7850 		return;
7851 
7852 	netdev_adjacent_dev_enable(dev, old_dev);
7853 	__netdev_upper_dev_unlink(old_dev, dev, &priv);
7854 }
7855 EXPORT_SYMBOL(netdev_adjacent_change_commit);
7856 
netdev_adjacent_change_abort(struct net_device * old_dev,struct net_device * new_dev,struct net_device * dev)7857 void netdev_adjacent_change_abort(struct net_device *old_dev,
7858 				  struct net_device *new_dev,
7859 				  struct net_device *dev)
7860 {
7861 	struct netdev_nested_priv priv = {
7862 		.flags = 0,
7863 		.data = NULL,
7864 	};
7865 
7866 	if (!new_dev)
7867 		return;
7868 
7869 	if (old_dev && new_dev != old_dev)
7870 		netdev_adjacent_dev_enable(dev, old_dev);
7871 
7872 	__netdev_upper_dev_unlink(new_dev, dev, &priv);
7873 }
7874 EXPORT_SYMBOL(netdev_adjacent_change_abort);
7875 
7876 /**
7877  * netdev_bonding_info_change - Dispatch event about slave change
7878  * @dev: device
7879  * @bonding_info: info to dispatch
7880  *
7881  * Send NETDEV_BONDING_INFO to netdev notifiers with info.
7882  * The caller must hold the RTNL lock.
7883  */
netdev_bonding_info_change(struct net_device * dev,struct netdev_bonding_info * bonding_info)7884 void netdev_bonding_info_change(struct net_device *dev,
7885 				struct netdev_bonding_info *bonding_info)
7886 {
7887 	struct netdev_notifier_bonding_info info = {
7888 		.info.dev = dev,
7889 	};
7890 
7891 	memcpy(&info.bonding_info, bonding_info,
7892 	       sizeof(struct netdev_bonding_info));
7893 	call_netdevice_notifiers_info(NETDEV_BONDING_INFO,
7894 				      &info.info);
7895 }
7896 EXPORT_SYMBOL(netdev_bonding_info_change);
7897 
netdev_offload_xstats_enable_l3(struct net_device * dev,struct netlink_ext_ack * extack)7898 static int netdev_offload_xstats_enable_l3(struct net_device *dev,
7899 					   struct netlink_ext_ack *extack)
7900 {
7901 	struct netdev_notifier_offload_xstats_info info = {
7902 		.info.dev = dev,
7903 		.info.extack = extack,
7904 		.type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
7905 	};
7906 	int err;
7907 	int rc;
7908 
7909 	dev->offload_xstats_l3 = kzalloc(sizeof(*dev->offload_xstats_l3),
7910 					 GFP_KERNEL);
7911 	if (!dev->offload_xstats_l3)
7912 		return -ENOMEM;
7913 
7914 	rc = call_netdevice_notifiers_info_robust(NETDEV_OFFLOAD_XSTATS_ENABLE,
7915 						  NETDEV_OFFLOAD_XSTATS_DISABLE,
7916 						  &info.info);
7917 	err = notifier_to_errno(rc);
7918 	if (err)
7919 		goto free_stats;
7920 
7921 	return 0;
7922 
7923 free_stats:
7924 	kfree(dev->offload_xstats_l3);
7925 	dev->offload_xstats_l3 = NULL;
7926 	return err;
7927 }
7928 
netdev_offload_xstats_enable(struct net_device * dev,enum netdev_offload_xstats_type type,struct netlink_ext_ack * extack)7929 int netdev_offload_xstats_enable(struct net_device *dev,
7930 				 enum netdev_offload_xstats_type type,
7931 				 struct netlink_ext_ack *extack)
7932 {
7933 	ASSERT_RTNL();
7934 
7935 	if (netdev_offload_xstats_enabled(dev, type))
7936 		return -EALREADY;
7937 
7938 	switch (type) {
7939 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
7940 		return netdev_offload_xstats_enable_l3(dev, extack);
7941 	}
7942 
7943 	WARN_ON(1);
7944 	return -EINVAL;
7945 }
7946 EXPORT_SYMBOL(netdev_offload_xstats_enable);
7947 
netdev_offload_xstats_disable_l3(struct net_device * dev)7948 static void netdev_offload_xstats_disable_l3(struct net_device *dev)
7949 {
7950 	struct netdev_notifier_offload_xstats_info info = {
7951 		.info.dev = dev,
7952 		.type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
7953 	};
7954 
7955 	call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_DISABLE,
7956 				      &info.info);
7957 	kfree(dev->offload_xstats_l3);
7958 	dev->offload_xstats_l3 = NULL;
7959 }
7960 
netdev_offload_xstats_disable(struct net_device * dev,enum netdev_offload_xstats_type type)7961 int netdev_offload_xstats_disable(struct net_device *dev,
7962 				  enum netdev_offload_xstats_type type)
7963 {
7964 	ASSERT_RTNL();
7965 
7966 	if (!netdev_offload_xstats_enabled(dev, type))
7967 		return -EALREADY;
7968 
7969 	switch (type) {
7970 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
7971 		netdev_offload_xstats_disable_l3(dev);
7972 		return 0;
7973 	}
7974 
7975 	WARN_ON(1);
7976 	return -EINVAL;
7977 }
7978 EXPORT_SYMBOL(netdev_offload_xstats_disable);
7979 
netdev_offload_xstats_disable_all(struct net_device * dev)7980 static void netdev_offload_xstats_disable_all(struct net_device *dev)
7981 {
7982 	netdev_offload_xstats_disable(dev, NETDEV_OFFLOAD_XSTATS_TYPE_L3);
7983 }
7984 
7985 static struct rtnl_hw_stats64 *
netdev_offload_xstats_get_ptr(const struct net_device * dev,enum netdev_offload_xstats_type type)7986 netdev_offload_xstats_get_ptr(const struct net_device *dev,
7987 			      enum netdev_offload_xstats_type type)
7988 {
7989 	switch (type) {
7990 	case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
7991 		return dev->offload_xstats_l3;
7992 	}
7993 
7994 	WARN_ON(1);
7995 	return NULL;
7996 }
7997 
netdev_offload_xstats_enabled(const struct net_device * dev,enum netdev_offload_xstats_type type)7998 bool netdev_offload_xstats_enabled(const struct net_device *dev,
7999 				   enum netdev_offload_xstats_type type)
8000 {
8001 	ASSERT_RTNL();
8002 
8003 	return netdev_offload_xstats_get_ptr(dev, type);
8004 }
8005 EXPORT_SYMBOL(netdev_offload_xstats_enabled);
8006 
8007 struct netdev_notifier_offload_xstats_ru {
8008 	bool used;
8009 };
8010 
8011 struct netdev_notifier_offload_xstats_rd {
8012 	struct rtnl_hw_stats64 stats;
8013 	bool used;
8014 };
8015 
netdev_hw_stats64_add(struct rtnl_hw_stats64 * dest,const struct rtnl_hw_stats64 * src)8016 static void netdev_hw_stats64_add(struct rtnl_hw_stats64 *dest,
8017 				  const struct rtnl_hw_stats64 *src)
8018 {
8019 	dest->rx_packets	  += src->rx_packets;
8020 	dest->tx_packets	  += src->tx_packets;
8021 	dest->rx_bytes		  += src->rx_bytes;
8022 	dest->tx_bytes		  += src->tx_bytes;
8023 	dest->rx_errors		  += src->rx_errors;
8024 	dest->tx_errors		  += src->tx_errors;
8025 	dest->rx_dropped	  += src->rx_dropped;
8026 	dest->tx_dropped	  += src->tx_dropped;
8027 	dest->multicast		  += src->multicast;
8028 }
8029 
netdev_offload_xstats_get_used(struct net_device * dev,enum netdev_offload_xstats_type type,bool * p_used,struct netlink_ext_ack * extack)8030 static int netdev_offload_xstats_get_used(struct net_device *dev,
8031 					  enum netdev_offload_xstats_type type,
8032 					  bool *p_used,
8033 					  struct netlink_ext_ack *extack)
8034 {
8035 	struct netdev_notifier_offload_xstats_ru report_used = {};
8036 	struct netdev_notifier_offload_xstats_info info = {
8037 		.info.dev = dev,
8038 		.info.extack = extack,
8039 		.type = type,
8040 		.report_used = &report_used,
8041 	};
8042 	int rc;
8043 
8044 	WARN_ON(!netdev_offload_xstats_enabled(dev, type));
8045 	rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_USED,
8046 					   &info.info);
8047 	*p_used = report_used.used;
8048 	return notifier_to_errno(rc);
8049 }
8050 
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)8051 static int netdev_offload_xstats_get_stats(struct net_device *dev,
8052 					   enum netdev_offload_xstats_type type,
8053 					   struct rtnl_hw_stats64 *p_stats,
8054 					   bool *p_used,
8055 					   struct netlink_ext_ack *extack)
8056 {
8057 	struct netdev_notifier_offload_xstats_rd report_delta = {};
8058 	struct netdev_notifier_offload_xstats_info info = {
8059 		.info.dev = dev,
8060 		.info.extack = extack,
8061 		.type = type,
8062 		.report_delta = &report_delta,
8063 	};
8064 	struct rtnl_hw_stats64 *stats;
8065 	int rc;
8066 
8067 	stats = netdev_offload_xstats_get_ptr(dev, type);
8068 	if (WARN_ON(!stats))
8069 		return -EINVAL;
8070 
8071 	rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_DELTA,
8072 					   &info.info);
8073 
8074 	/* Cache whatever we got, even if there was an error, otherwise the
8075 	 * successful stats retrievals would get lost.
8076 	 */
8077 	netdev_hw_stats64_add(stats, &report_delta.stats);
8078 
8079 	if (p_stats)
8080 		*p_stats = *stats;
8081 	*p_used = report_delta.used;
8082 
8083 	return notifier_to_errno(rc);
8084 }
8085 
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)8086 int netdev_offload_xstats_get(struct net_device *dev,
8087 			      enum netdev_offload_xstats_type type,
8088 			      struct rtnl_hw_stats64 *p_stats, bool *p_used,
8089 			      struct netlink_ext_ack *extack)
8090 {
8091 	ASSERT_RTNL();
8092 
8093 	if (p_stats)
8094 		return netdev_offload_xstats_get_stats(dev, type, p_stats,
8095 						       p_used, extack);
8096 	else
8097 		return netdev_offload_xstats_get_used(dev, type, p_used,
8098 						      extack);
8099 }
8100 EXPORT_SYMBOL(netdev_offload_xstats_get);
8101 
8102 void
netdev_offload_xstats_report_delta(struct netdev_notifier_offload_xstats_rd * report_delta,const struct rtnl_hw_stats64 * stats)8103 netdev_offload_xstats_report_delta(struct netdev_notifier_offload_xstats_rd *report_delta,
8104 				   const struct rtnl_hw_stats64 *stats)
8105 {
8106 	report_delta->used = true;
8107 	netdev_hw_stats64_add(&report_delta->stats, stats);
8108 }
8109 EXPORT_SYMBOL(netdev_offload_xstats_report_delta);
8110 
8111 void
netdev_offload_xstats_report_used(struct netdev_notifier_offload_xstats_ru * report_used)8112 netdev_offload_xstats_report_used(struct netdev_notifier_offload_xstats_ru *report_used)
8113 {
8114 	report_used->used = true;
8115 }
8116 EXPORT_SYMBOL(netdev_offload_xstats_report_used);
8117 
netdev_offload_xstats_push_delta(struct net_device * dev,enum netdev_offload_xstats_type type,const struct rtnl_hw_stats64 * p_stats)8118 void netdev_offload_xstats_push_delta(struct net_device *dev,
8119 				      enum netdev_offload_xstats_type type,
8120 				      const struct rtnl_hw_stats64 *p_stats)
8121 {
8122 	struct rtnl_hw_stats64 *stats;
8123 
8124 	ASSERT_RTNL();
8125 
8126 	stats = netdev_offload_xstats_get_ptr(dev, type);
8127 	if (WARN_ON(!stats))
8128 		return;
8129 
8130 	netdev_hw_stats64_add(stats, p_stats);
8131 }
8132 EXPORT_SYMBOL(netdev_offload_xstats_push_delta);
8133 
8134 /**
8135  * netdev_get_xmit_slave - Get the xmit slave of master device
8136  * @dev: device
8137  * @skb: The packet
8138  * @all_slaves: assume all the slaves are active
8139  *
8140  * The reference counters are not incremented so the caller must be
8141  * careful with locks. The caller must hold RCU lock.
8142  * %NULL is returned if no slave is found.
8143  */
8144 
netdev_get_xmit_slave(struct net_device * dev,struct sk_buff * skb,bool all_slaves)8145 struct net_device *netdev_get_xmit_slave(struct net_device *dev,
8146 					 struct sk_buff *skb,
8147 					 bool all_slaves)
8148 {
8149 	const struct net_device_ops *ops = dev->netdev_ops;
8150 
8151 	if (!ops->ndo_get_xmit_slave)
8152 		return NULL;
8153 	return ops->ndo_get_xmit_slave(dev, skb, all_slaves);
8154 }
8155 EXPORT_SYMBOL(netdev_get_xmit_slave);
8156 
netdev_sk_get_lower_dev(struct net_device * dev,struct sock * sk)8157 static struct net_device *netdev_sk_get_lower_dev(struct net_device *dev,
8158 						  struct sock *sk)
8159 {
8160 	const struct net_device_ops *ops = dev->netdev_ops;
8161 
8162 	if (!ops->ndo_sk_get_lower_dev)
8163 		return NULL;
8164 	return ops->ndo_sk_get_lower_dev(dev, sk);
8165 }
8166 
8167 /**
8168  * netdev_sk_get_lowest_dev - Get the lowest device in chain given device and socket
8169  * @dev: device
8170  * @sk: the socket
8171  *
8172  * %NULL is returned if no lower device is found.
8173  */
8174 
netdev_sk_get_lowest_dev(struct net_device * dev,struct sock * sk)8175 struct net_device *netdev_sk_get_lowest_dev(struct net_device *dev,
8176 					    struct sock *sk)
8177 {
8178 	struct net_device *lower;
8179 
8180 	lower = netdev_sk_get_lower_dev(dev, sk);
8181 	while (lower) {
8182 		dev = lower;
8183 		lower = netdev_sk_get_lower_dev(dev, sk);
8184 	}
8185 
8186 	return dev;
8187 }
8188 EXPORT_SYMBOL(netdev_sk_get_lowest_dev);
8189 
netdev_adjacent_add_links(struct net_device * dev)8190 static void netdev_adjacent_add_links(struct net_device *dev)
8191 {
8192 	struct netdev_adjacent *iter;
8193 
8194 	struct net *net = dev_net(dev);
8195 
8196 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8197 		if (!net_eq(net, dev_net(iter->dev)))
8198 			continue;
8199 		netdev_adjacent_sysfs_add(iter->dev, dev,
8200 					  &iter->dev->adj_list.lower);
8201 		netdev_adjacent_sysfs_add(dev, iter->dev,
8202 					  &dev->adj_list.upper);
8203 	}
8204 
8205 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8206 		if (!net_eq(net, dev_net(iter->dev)))
8207 			continue;
8208 		netdev_adjacent_sysfs_add(iter->dev, dev,
8209 					  &iter->dev->adj_list.upper);
8210 		netdev_adjacent_sysfs_add(dev, iter->dev,
8211 					  &dev->adj_list.lower);
8212 	}
8213 }
8214 
netdev_adjacent_del_links(struct net_device * dev)8215 static void netdev_adjacent_del_links(struct net_device *dev)
8216 {
8217 	struct netdev_adjacent *iter;
8218 
8219 	struct net *net = dev_net(dev);
8220 
8221 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8222 		if (!net_eq(net, dev_net(iter->dev)))
8223 			continue;
8224 		netdev_adjacent_sysfs_del(iter->dev, dev->name,
8225 					  &iter->dev->adj_list.lower);
8226 		netdev_adjacent_sysfs_del(dev, iter->dev->name,
8227 					  &dev->adj_list.upper);
8228 	}
8229 
8230 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8231 		if (!net_eq(net, dev_net(iter->dev)))
8232 			continue;
8233 		netdev_adjacent_sysfs_del(iter->dev, dev->name,
8234 					  &iter->dev->adj_list.upper);
8235 		netdev_adjacent_sysfs_del(dev, iter->dev->name,
8236 					  &dev->adj_list.lower);
8237 	}
8238 }
8239 
netdev_adjacent_rename_links(struct net_device * dev,char * oldname)8240 void netdev_adjacent_rename_links(struct net_device *dev, char *oldname)
8241 {
8242 	struct netdev_adjacent *iter;
8243 
8244 	struct net *net = dev_net(dev);
8245 
8246 	list_for_each_entry(iter, &dev->adj_list.upper, list) {
8247 		if (!net_eq(net, dev_net(iter->dev)))
8248 			continue;
8249 		netdev_adjacent_sysfs_del(iter->dev, oldname,
8250 					  &iter->dev->adj_list.lower);
8251 		netdev_adjacent_sysfs_add(iter->dev, dev,
8252 					  &iter->dev->adj_list.lower);
8253 	}
8254 
8255 	list_for_each_entry(iter, &dev->adj_list.lower, list) {
8256 		if (!net_eq(net, dev_net(iter->dev)))
8257 			continue;
8258 		netdev_adjacent_sysfs_del(iter->dev, oldname,
8259 					  &iter->dev->adj_list.upper);
8260 		netdev_adjacent_sysfs_add(iter->dev, dev,
8261 					  &iter->dev->adj_list.upper);
8262 	}
8263 }
8264 
netdev_lower_dev_get_private(struct net_device * dev,struct net_device * lower_dev)8265 void *netdev_lower_dev_get_private(struct net_device *dev,
8266 				   struct net_device *lower_dev)
8267 {
8268 	struct netdev_adjacent *lower;
8269 
8270 	if (!lower_dev)
8271 		return NULL;
8272 	lower = __netdev_find_adj(lower_dev, &dev->adj_list.lower);
8273 	if (!lower)
8274 		return NULL;
8275 
8276 	return lower->private;
8277 }
8278 EXPORT_SYMBOL(netdev_lower_dev_get_private);
8279 
8280 
8281 /**
8282  * netdev_lower_state_changed - Dispatch event about lower device state change
8283  * @lower_dev: device
8284  * @lower_state_info: state to dispatch
8285  *
8286  * Send NETDEV_CHANGELOWERSTATE to netdev notifiers with info.
8287  * The caller must hold the RTNL lock.
8288  */
netdev_lower_state_changed(struct net_device * lower_dev,void * lower_state_info)8289 void netdev_lower_state_changed(struct net_device *lower_dev,
8290 				void *lower_state_info)
8291 {
8292 	struct netdev_notifier_changelowerstate_info changelowerstate_info = {
8293 		.info.dev = lower_dev,
8294 	};
8295 
8296 	ASSERT_RTNL();
8297 	changelowerstate_info.lower_state_info = lower_state_info;
8298 	call_netdevice_notifiers_info(NETDEV_CHANGELOWERSTATE,
8299 				      &changelowerstate_info.info);
8300 }
8301 EXPORT_SYMBOL(netdev_lower_state_changed);
8302 
dev_change_rx_flags(struct net_device * dev,int flags)8303 static void dev_change_rx_flags(struct net_device *dev, int flags)
8304 {
8305 	const struct net_device_ops *ops = dev->netdev_ops;
8306 
8307 	if (ops->ndo_change_rx_flags)
8308 		ops->ndo_change_rx_flags(dev, flags);
8309 }
8310 
__dev_set_promiscuity(struct net_device * dev,int inc,bool notify)8311 static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify)
8312 {
8313 	unsigned int old_flags = dev->flags;
8314 	kuid_t uid;
8315 	kgid_t gid;
8316 
8317 	ASSERT_RTNL();
8318 
8319 	dev->flags |= IFF_PROMISC;
8320 	dev->promiscuity += inc;
8321 	if (dev->promiscuity == 0) {
8322 		/*
8323 		 * Avoid overflow.
8324 		 * If inc causes overflow, untouch promisc and return error.
8325 		 */
8326 		if (inc < 0)
8327 			dev->flags &= ~IFF_PROMISC;
8328 		else {
8329 			dev->promiscuity -= inc;
8330 			netdev_warn(dev, "promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n");
8331 			return -EOVERFLOW;
8332 		}
8333 	}
8334 	if (dev->flags != old_flags) {
8335 		pr_info("device %s %s promiscuous mode\n",
8336 			dev->name,
8337 			dev->flags & IFF_PROMISC ? "entered" : "left");
8338 		if (audit_enabled) {
8339 			current_uid_gid(&uid, &gid);
8340 			audit_log(audit_context(), GFP_ATOMIC,
8341 				  AUDIT_ANOM_PROMISCUOUS,
8342 				  "dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
8343 				  dev->name, (dev->flags & IFF_PROMISC),
8344 				  (old_flags & IFF_PROMISC),
8345 				  from_kuid(&init_user_ns, audit_get_loginuid(current)),
8346 				  from_kuid(&init_user_ns, uid),
8347 				  from_kgid(&init_user_ns, gid),
8348 				  audit_get_sessionid(current));
8349 		}
8350 
8351 		dev_change_rx_flags(dev, IFF_PROMISC);
8352 	}
8353 	if (notify)
8354 		__dev_notify_flags(dev, old_flags, IFF_PROMISC);
8355 	return 0;
8356 }
8357 
8358 /**
8359  *	dev_set_promiscuity	- update promiscuity count on a device
8360  *	@dev: device
8361  *	@inc: modifier
8362  *
8363  *	Add or remove promiscuity from a device. While the count in the device
8364  *	remains above zero the interface remains promiscuous. Once it hits zero
8365  *	the device reverts back to normal filtering operation. A negative inc
8366  *	value is used to drop promiscuity on the device.
8367  *	Return 0 if successful or a negative errno code on error.
8368  */
dev_set_promiscuity(struct net_device * dev,int inc)8369 int dev_set_promiscuity(struct net_device *dev, int inc)
8370 {
8371 	unsigned int old_flags = dev->flags;
8372 	int err;
8373 
8374 	err = __dev_set_promiscuity(dev, inc, true);
8375 	if (err < 0)
8376 		return err;
8377 	if (dev->flags != old_flags)
8378 		dev_set_rx_mode(dev);
8379 	return err;
8380 }
8381 EXPORT_SYMBOL(dev_set_promiscuity);
8382 
__dev_set_allmulti(struct net_device * dev,int inc,bool notify)8383 static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify)
8384 {
8385 	unsigned int old_flags = dev->flags, old_gflags = dev->gflags;
8386 
8387 	ASSERT_RTNL();
8388 
8389 	dev->flags |= IFF_ALLMULTI;
8390 	dev->allmulti += inc;
8391 	if (dev->allmulti == 0) {
8392 		/*
8393 		 * Avoid overflow.
8394 		 * If inc causes overflow, untouch allmulti and return error.
8395 		 */
8396 		if (inc < 0)
8397 			dev->flags &= ~IFF_ALLMULTI;
8398 		else {
8399 			dev->allmulti -= inc;
8400 			netdev_warn(dev, "allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n");
8401 			return -EOVERFLOW;
8402 		}
8403 	}
8404 	if (dev->flags ^ old_flags) {
8405 		dev_change_rx_flags(dev, IFF_ALLMULTI);
8406 		dev_set_rx_mode(dev);
8407 		if (notify)
8408 			__dev_notify_flags(dev, old_flags,
8409 					   dev->gflags ^ old_gflags);
8410 	}
8411 	return 0;
8412 }
8413 
8414 /**
8415  *	dev_set_allmulti	- update allmulti count on a device
8416  *	@dev: device
8417  *	@inc: modifier
8418  *
8419  *	Add or remove reception of all multicast frames to a device. While the
8420  *	count in the device remains above zero the interface remains listening
8421  *	to all interfaces. Once it hits zero the device reverts back to normal
8422  *	filtering operation. A negative @inc value is used to drop the counter
8423  *	when releasing a resource needing all multicasts.
8424  *	Return 0 if successful or a negative errno code on error.
8425  */
8426 
dev_set_allmulti(struct net_device * dev,int inc)8427 int dev_set_allmulti(struct net_device *dev, int inc)
8428 {
8429 	return __dev_set_allmulti(dev, inc, true);
8430 }
8431 EXPORT_SYMBOL(dev_set_allmulti);
8432 
8433 /*
8434  *	Upload unicast and multicast address lists to device and
8435  *	configure RX filtering. When the device doesn't support unicast
8436  *	filtering it is put in promiscuous mode while unicast addresses
8437  *	are present.
8438  */
__dev_set_rx_mode(struct net_device * dev)8439 void __dev_set_rx_mode(struct net_device *dev)
8440 {
8441 	const struct net_device_ops *ops = dev->netdev_ops;
8442 
8443 	/* dev_open will call this function so the list will stay sane. */
8444 	if (!(dev->flags&IFF_UP))
8445 		return;
8446 
8447 	if (!netif_device_present(dev))
8448 		return;
8449 
8450 	if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
8451 		/* Unicast addresses changes may only happen under the rtnl,
8452 		 * therefore calling __dev_set_promiscuity here is safe.
8453 		 */
8454 		if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
8455 			__dev_set_promiscuity(dev, 1, false);
8456 			dev->uc_promisc = true;
8457 		} else if (netdev_uc_empty(dev) && dev->uc_promisc) {
8458 			__dev_set_promiscuity(dev, -1, false);
8459 			dev->uc_promisc = false;
8460 		}
8461 	}
8462 
8463 	if (ops->ndo_set_rx_mode)
8464 		ops->ndo_set_rx_mode(dev);
8465 }
8466 
dev_set_rx_mode(struct net_device * dev)8467 void dev_set_rx_mode(struct net_device *dev)
8468 {
8469 	netif_addr_lock_bh(dev);
8470 	__dev_set_rx_mode(dev);
8471 	netif_addr_unlock_bh(dev);
8472 }
8473 
8474 /**
8475  *	dev_get_flags - get flags reported to userspace
8476  *	@dev: device
8477  *
8478  *	Get the combination of flag bits exported through APIs to userspace.
8479  */
dev_get_flags(const struct net_device * dev)8480 unsigned int dev_get_flags(const struct net_device *dev)
8481 {
8482 	unsigned int flags;
8483 
8484 	flags = (dev->flags & ~(IFF_PROMISC |
8485 				IFF_ALLMULTI |
8486 				IFF_RUNNING |
8487 				IFF_LOWER_UP |
8488 				IFF_DORMANT)) |
8489 		(dev->gflags & (IFF_PROMISC |
8490 				IFF_ALLMULTI));
8491 
8492 	if (netif_running(dev)) {
8493 		if (netif_oper_up(dev))
8494 			flags |= IFF_RUNNING;
8495 		if (netif_carrier_ok(dev))
8496 			flags |= IFF_LOWER_UP;
8497 		if (netif_dormant(dev))
8498 			flags |= IFF_DORMANT;
8499 	}
8500 
8501 	return flags;
8502 }
8503 EXPORT_SYMBOL(dev_get_flags);
8504 
__dev_change_flags(struct net_device * dev,unsigned int flags,struct netlink_ext_ack * extack)8505 int __dev_change_flags(struct net_device *dev, unsigned int flags,
8506 		       struct netlink_ext_ack *extack)
8507 {
8508 	unsigned int old_flags = dev->flags;
8509 	int ret;
8510 
8511 	ASSERT_RTNL();
8512 
8513 	/*
8514 	 *	Set the flags on our device.
8515 	 */
8516 
8517 	dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
8518 			       IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
8519 			       IFF_AUTOMEDIA)) |
8520 		     (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
8521 				    IFF_ALLMULTI));
8522 
8523 	/*
8524 	 *	Load in the correct multicast list now the flags have changed.
8525 	 */
8526 
8527 	if ((old_flags ^ flags) & IFF_MULTICAST)
8528 		dev_change_rx_flags(dev, IFF_MULTICAST);
8529 
8530 	dev_set_rx_mode(dev);
8531 
8532 	/*
8533 	 *	Have we downed the interface. We handle IFF_UP ourselves
8534 	 *	according to user attempts to set it, rather than blindly
8535 	 *	setting it.
8536 	 */
8537 
8538 	ret = 0;
8539 	if ((old_flags ^ flags) & IFF_UP) {
8540 		if (old_flags & IFF_UP)
8541 			__dev_close(dev);
8542 		else
8543 			ret = __dev_open(dev, extack);
8544 	}
8545 
8546 	if ((flags ^ dev->gflags) & IFF_PROMISC) {
8547 		int inc = (flags & IFF_PROMISC) ? 1 : -1;
8548 		unsigned int old_flags = dev->flags;
8549 
8550 		dev->gflags ^= IFF_PROMISC;
8551 
8552 		if (__dev_set_promiscuity(dev, inc, false) >= 0)
8553 			if (dev->flags != old_flags)
8554 				dev_set_rx_mode(dev);
8555 	}
8556 
8557 	/* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
8558 	 * is important. Some (broken) drivers set IFF_PROMISC, when
8559 	 * IFF_ALLMULTI is requested not asking us and not reporting.
8560 	 */
8561 	if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
8562 		int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
8563 
8564 		dev->gflags ^= IFF_ALLMULTI;
8565 		__dev_set_allmulti(dev, inc, false);
8566 	}
8567 
8568 	return ret;
8569 }
8570 
__dev_notify_flags(struct net_device * dev,unsigned int old_flags,unsigned int gchanges)8571 void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
8572 			unsigned int gchanges)
8573 {
8574 	unsigned int changes = dev->flags ^ old_flags;
8575 
8576 	if (gchanges)
8577 		rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC);
8578 
8579 	if (changes & IFF_UP) {
8580 		if (dev->flags & IFF_UP)
8581 			call_netdevice_notifiers(NETDEV_UP, dev);
8582 		else
8583 			call_netdevice_notifiers(NETDEV_DOWN, dev);
8584 	}
8585 
8586 	if (dev->flags & IFF_UP &&
8587 	    (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE))) {
8588 		struct netdev_notifier_change_info change_info = {
8589 			.info = {
8590 				.dev = dev,
8591 			},
8592 			.flags_changed = changes,
8593 		};
8594 
8595 		call_netdevice_notifiers_info(NETDEV_CHANGE, &change_info.info);
8596 	}
8597 }
8598 
8599 /**
8600  *	dev_change_flags - change device settings
8601  *	@dev: device
8602  *	@flags: device state flags
8603  *	@extack: netlink extended ack
8604  *
8605  *	Change settings on device based state flags. The flags are
8606  *	in the userspace exported format.
8607  */
dev_change_flags(struct net_device * dev,unsigned int flags,struct netlink_ext_ack * extack)8608 int dev_change_flags(struct net_device *dev, unsigned int flags,
8609 		     struct netlink_ext_ack *extack)
8610 {
8611 	int ret;
8612 	unsigned int changes, old_flags = dev->flags, old_gflags = dev->gflags;
8613 
8614 	ret = __dev_change_flags(dev, flags, extack);
8615 	if (ret < 0)
8616 		return ret;
8617 
8618 	changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags);
8619 	__dev_notify_flags(dev, old_flags, changes);
8620 	return ret;
8621 }
8622 EXPORT_SYMBOL(dev_change_flags);
8623 
__dev_set_mtu(struct net_device * dev,int new_mtu)8624 int __dev_set_mtu(struct net_device *dev, int new_mtu)
8625 {
8626 	const struct net_device_ops *ops = dev->netdev_ops;
8627 
8628 	if (ops->ndo_change_mtu)
8629 		return ops->ndo_change_mtu(dev, new_mtu);
8630 
8631 	/* Pairs with all the lockless reads of dev->mtu in the stack */
8632 	WRITE_ONCE(dev->mtu, new_mtu);
8633 	return 0;
8634 }
8635 EXPORT_SYMBOL(__dev_set_mtu);
8636 
dev_validate_mtu(struct net_device * dev,int new_mtu,struct netlink_ext_ack * extack)8637 int dev_validate_mtu(struct net_device *dev, int new_mtu,
8638 		     struct netlink_ext_ack *extack)
8639 {
8640 	/* MTU must be positive, and in range */
8641 	if (new_mtu < 0 || new_mtu < dev->min_mtu) {
8642 		NL_SET_ERR_MSG(extack, "mtu less than device minimum");
8643 		return -EINVAL;
8644 	}
8645 
8646 	if (dev->max_mtu > 0 && new_mtu > dev->max_mtu) {
8647 		NL_SET_ERR_MSG(extack, "mtu greater than device maximum");
8648 		return -EINVAL;
8649 	}
8650 	return 0;
8651 }
8652 
8653 /**
8654  *	dev_set_mtu_ext - Change maximum transfer unit
8655  *	@dev: device
8656  *	@new_mtu: new transfer unit
8657  *	@extack: netlink extended ack
8658  *
8659  *	Change the maximum transfer size of the network device.
8660  */
dev_set_mtu_ext(struct net_device * dev,int new_mtu,struct netlink_ext_ack * extack)8661 int dev_set_mtu_ext(struct net_device *dev, int new_mtu,
8662 		    struct netlink_ext_ack *extack)
8663 {
8664 	int err, orig_mtu;
8665 
8666 	if (new_mtu == dev->mtu)
8667 		return 0;
8668 
8669 	err = dev_validate_mtu(dev, new_mtu, extack);
8670 	if (err)
8671 		return err;
8672 
8673 	if (!netif_device_present(dev))
8674 		return -ENODEV;
8675 
8676 	err = call_netdevice_notifiers(NETDEV_PRECHANGEMTU, dev);
8677 	err = notifier_to_errno(err);
8678 	if (err)
8679 		return err;
8680 
8681 	orig_mtu = dev->mtu;
8682 	err = __dev_set_mtu(dev, new_mtu);
8683 
8684 	if (!err) {
8685 		err = call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8686 						   orig_mtu);
8687 		err = notifier_to_errno(err);
8688 		if (err) {
8689 			/* setting mtu back and notifying everyone again,
8690 			 * so that they have a chance to revert changes.
8691 			 */
8692 			__dev_set_mtu(dev, orig_mtu);
8693 			call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8694 						     new_mtu);
8695 		}
8696 	}
8697 	return err;
8698 }
8699 
dev_set_mtu(struct net_device * dev,int new_mtu)8700 int dev_set_mtu(struct net_device *dev, int new_mtu)
8701 {
8702 	struct netlink_ext_ack extack;
8703 	int err;
8704 
8705 	memset(&extack, 0, sizeof(extack));
8706 	err = dev_set_mtu_ext(dev, new_mtu, &extack);
8707 	if (err && extack._msg)
8708 		net_err_ratelimited("%s: %s\n", dev->name, extack._msg);
8709 	return err;
8710 }
8711 EXPORT_SYMBOL(dev_set_mtu);
8712 
8713 /**
8714  *	dev_change_tx_queue_len - Change TX queue length of a netdevice
8715  *	@dev: device
8716  *	@new_len: new tx queue length
8717  */
dev_change_tx_queue_len(struct net_device * dev,unsigned long new_len)8718 int dev_change_tx_queue_len(struct net_device *dev, unsigned long new_len)
8719 {
8720 	unsigned int orig_len = dev->tx_queue_len;
8721 	int res;
8722 
8723 	if (new_len != (unsigned int)new_len)
8724 		return -ERANGE;
8725 
8726 	if (new_len != orig_len) {
8727 		dev->tx_queue_len = new_len;
8728 		res = call_netdevice_notifiers(NETDEV_CHANGE_TX_QUEUE_LEN, dev);
8729 		res = notifier_to_errno(res);
8730 		if (res)
8731 			goto err_rollback;
8732 		res = dev_qdisc_change_tx_queue_len(dev);
8733 		if (res)
8734 			goto err_rollback;
8735 	}
8736 
8737 	return 0;
8738 
8739 err_rollback:
8740 	netdev_err(dev, "refused to change device tx_queue_len\n");
8741 	dev->tx_queue_len = orig_len;
8742 	return res;
8743 }
8744 
8745 /**
8746  *	dev_set_group - Change group this device belongs to
8747  *	@dev: device
8748  *	@new_group: group this device should belong to
8749  */
dev_set_group(struct net_device * dev,int new_group)8750 void dev_set_group(struct net_device *dev, int new_group)
8751 {
8752 	dev->group = new_group;
8753 }
8754 
8755 /**
8756  *	dev_pre_changeaddr_notify - Call NETDEV_PRE_CHANGEADDR.
8757  *	@dev: device
8758  *	@addr: new address
8759  *	@extack: netlink extended ack
8760  */
dev_pre_changeaddr_notify(struct net_device * dev,const char * addr,struct netlink_ext_ack * extack)8761 int dev_pre_changeaddr_notify(struct net_device *dev, const char *addr,
8762 			      struct netlink_ext_ack *extack)
8763 {
8764 	struct netdev_notifier_pre_changeaddr_info info = {
8765 		.info.dev = dev,
8766 		.info.extack = extack,
8767 		.dev_addr = addr,
8768 	};
8769 	int rc;
8770 
8771 	rc = call_netdevice_notifiers_info(NETDEV_PRE_CHANGEADDR, &info.info);
8772 	return notifier_to_errno(rc);
8773 }
8774 EXPORT_SYMBOL(dev_pre_changeaddr_notify);
8775 
8776 /**
8777  *	dev_set_mac_address - Change Media Access Control Address
8778  *	@dev: device
8779  *	@sa: new address
8780  *	@extack: netlink extended ack
8781  *
8782  *	Change the hardware (MAC) address of the device
8783  */
dev_set_mac_address(struct net_device * dev,struct sockaddr * sa,struct netlink_ext_ack * extack)8784 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa,
8785 			struct netlink_ext_ack *extack)
8786 {
8787 	const struct net_device_ops *ops = dev->netdev_ops;
8788 	int err;
8789 
8790 	if (!ops->ndo_set_mac_address)
8791 		return -EOPNOTSUPP;
8792 	if (sa->sa_family != dev->type)
8793 		return -EINVAL;
8794 	if (!netif_device_present(dev))
8795 		return -ENODEV;
8796 	err = dev_pre_changeaddr_notify(dev, sa->sa_data, extack);
8797 	if (err)
8798 		return err;
8799 	err = ops->ndo_set_mac_address(dev, sa);
8800 	if (err)
8801 		return err;
8802 	dev->addr_assign_type = NET_ADDR_SET;
8803 	call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
8804 	add_device_randomness(dev->dev_addr, dev->addr_len);
8805 	return 0;
8806 }
8807 EXPORT_SYMBOL(dev_set_mac_address);
8808 
8809 static DECLARE_RWSEM(dev_addr_sem);
8810 
dev_set_mac_address_user(struct net_device * dev,struct sockaddr * sa,struct netlink_ext_ack * extack)8811 int dev_set_mac_address_user(struct net_device *dev, struct sockaddr *sa,
8812 			     struct netlink_ext_ack *extack)
8813 {
8814 	int ret;
8815 
8816 	down_write(&dev_addr_sem);
8817 	ret = dev_set_mac_address(dev, sa, extack);
8818 	up_write(&dev_addr_sem);
8819 	return ret;
8820 }
8821 EXPORT_SYMBOL(dev_set_mac_address_user);
8822 
dev_get_mac_address(struct sockaddr * sa,struct net * net,char * dev_name)8823 int dev_get_mac_address(struct sockaddr *sa, struct net *net, char *dev_name)
8824 {
8825 	size_t size = sizeof(sa->sa_data);
8826 	struct net_device *dev;
8827 	int ret = 0;
8828 
8829 	down_read(&dev_addr_sem);
8830 	rcu_read_lock();
8831 
8832 	dev = dev_get_by_name_rcu(net, dev_name);
8833 	if (!dev) {
8834 		ret = -ENODEV;
8835 		goto unlock;
8836 	}
8837 	if (!dev->addr_len)
8838 		memset(sa->sa_data, 0, size);
8839 	else
8840 		memcpy(sa->sa_data, dev->dev_addr,
8841 		       min_t(size_t, size, dev->addr_len));
8842 	sa->sa_family = dev->type;
8843 
8844 unlock:
8845 	rcu_read_unlock();
8846 	up_read(&dev_addr_sem);
8847 	return ret;
8848 }
8849 EXPORT_SYMBOL(dev_get_mac_address);
8850 
8851 /**
8852  *	dev_change_carrier - Change device carrier
8853  *	@dev: device
8854  *	@new_carrier: new value
8855  *
8856  *	Change device carrier
8857  */
dev_change_carrier(struct net_device * dev,bool new_carrier)8858 int dev_change_carrier(struct net_device *dev, bool new_carrier)
8859 {
8860 	const struct net_device_ops *ops = dev->netdev_ops;
8861 
8862 	if (!ops->ndo_change_carrier)
8863 		return -EOPNOTSUPP;
8864 	if (!netif_device_present(dev))
8865 		return -ENODEV;
8866 	return ops->ndo_change_carrier(dev, new_carrier);
8867 }
8868 
8869 /**
8870  *	dev_get_phys_port_id - Get device physical port ID
8871  *	@dev: device
8872  *	@ppid: port ID
8873  *
8874  *	Get device physical port ID
8875  */
dev_get_phys_port_id(struct net_device * dev,struct netdev_phys_item_id * ppid)8876 int dev_get_phys_port_id(struct net_device *dev,
8877 			 struct netdev_phys_item_id *ppid)
8878 {
8879 	const struct net_device_ops *ops = dev->netdev_ops;
8880 
8881 	if (!ops->ndo_get_phys_port_id)
8882 		return -EOPNOTSUPP;
8883 	return ops->ndo_get_phys_port_id(dev, ppid);
8884 }
8885 
8886 /**
8887  *	dev_get_phys_port_name - Get device physical port name
8888  *	@dev: device
8889  *	@name: port name
8890  *	@len: limit of bytes to copy to name
8891  *
8892  *	Get device physical port name
8893  */
dev_get_phys_port_name(struct net_device * dev,char * name,size_t len)8894 int dev_get_phys_port_name(struct net_device *dev,
8895 			   char *name, size_t len)
8896 {
8897 	const struct net_device_ops *ops = dev->netdev_ops;
8898 	int err;
8899 
8900 	if (ops->ndo_get_phys_port_name) {
8901 		err = ops->ndo_get_phys_port_name(dev, name, len);
8902 		if (err != -EOPNOTSUPP)
8903 			return err;
8904 	}
8905 	return devlink_compat_phys_port_name_get(dev, name, len);
8906 }
8907 
8908 /**
8909  *	dev_get_port_parent_id - Get the device's port parent identifier
8910  *	@dev: network device
8911  *	@ppid: pointer to a storage for the port's parent identifier
8912  *	@recurse: allow/disallow recursion to lower devices
8913  *
8914  *	Get the devices's port parent identifier
8915  */
dev_get_port_parent_id(struct net_device * dev,struct netdev_phys_item_id * ppid,bool recurse)8916 int dev_get_port_parent_id(struct net_device *dev,
8917 			   struct netdev_phys_item_id *ppid,
8918 			   bool recurse)
8919 {
8920 	const struct net_device_ops *ops = dev->netdev_ops;
8921 	struct netdev_phys_item_id first = { };
8922 	struct net_device *lower_dev;
8923 	struct list_head *iter;
8924 	int err;
8925 
8926 	if (ops->ndo_get_port_parent_id) {
8927 		err = ops->ndo_get_port_parent_id(dev, ppid);
8928 		if (err != -EOPNOTSUPP)
8929 			return err;
8930 	}
8931 
8932 	err = devlink_compat_switch_id_get(dev, ppid);
8933 	if (!recurse || err != -EOPNOTSUPP)
8934 		return err;
8935 
8936 	netdev_for_each_lower_dev(dev, lower_dev, iter) {
8937 		err = dev_get_port_parent_id(lower_dev, ppid, true);
8938 		if (err)
8939 			break;
8940 		if (!first.id_len)
8941 			first = *ppid;
8942 		else if (memcmp(&first, ppid, sizeof(*ppid)))
8943 			return -EOPNOTSUPP;
8944 	}
8945 
8946 	return err;
8947 }
8948 EXPORT_SYMBOL(dev_get_port_parent_id);
8949 
8950 /**
8951  *	netdev_port_same_parent_id - Indicate if two network devices have
8952  *	the same port parent identifier
8953  *	@a: first network device
8954  *	@b: second network device
8955  */
netdev_port_same_parent_id(struct net_device * a,struct net_device * b)8956 bool netdev_port_same_parent_id(struct net_device *a, struct net_device *b)
8957 {
8958 	struct netdev_phys_item_id a_id = { };
8959 	struct netdev_phys_item_id b_id = { };
8960 
8961 	if (dev_get_port_parent_id(a, &a_id, true) ||
8962 	    dev_get_port_parent_id(b, &b_id, true))
8963 		return false;
8964 
8965 	return netdev_phys_item_id_same(&a_id, &b_id);
8966 }
8967 EXPORT_SYMBOL(netdev_port_same_parent_id);
8968 
8969 /**
8970  *	dev_change_proto_down - set carrier according to proto_down.
8971  *
8972  *	@dev: device
8973  *	@proto_down: new value
8974  */
dev_change_proto_down(struct net_device * dev,bool proto_down)8975 int dev_change_proto_down(struct net_device *dev, bool proto_down)
8976 {
8977 	if (!(dev->priv_flags & IFF_CHANGE_PROTO_DOWN))
8978 		return -EOPNOTSUPP;
8979 	if (!netif_device_present(dev))
8980 		return -ENODEV;
8981 	if (proto_down)
8982 		netif_carrier_off(dev);
8983 	else
8984 		netif_carrier_on(dev);
8985 	dev->proto_down = proto_down;
8986 	return 0;
8987 }
8988 
8989 /**
8990  *	dev_change_proto_down_reason - proto down reason
8991  *
8992  *	@dev: device
8993  *	@mask: proto down mask
8994  *	@value: proto down value
8995  */
dev_change_proto_down_reason(struct net_device * dev,unsigned long mask,u32 value)8996 void dev_change_proto_down_reason(struct net_device *dev, unsigned long mask,
8997 				  u32 value)
8998 {
8999 	int b;
9000 
9001 	if (!mask) {
9002 		dev->proto_down_reason = value;
9003 	} else {
9004 		for_each_set_bit(b, &mask, 32) {
9005 			if (value & (1 << b))
9006 				dev->proto_down_reason |= BIT(b);
9007 			else
9008 				dev->proto_down_reason &= ~BIT(b);
9009 		}
9010 	}
9011 }
9012 
9013 struct bpf_xdp_link {
9014 	struct bpf_link link;
9015 	struct net_device *dev; /* protected by rtnl_lock, no refcnt held */
9016 	int flags;
9017 };
9018 
dev_xdp_mode(struct net_device * dev,u32 flags)9019 static enum bpf_xdp_mode dev_xdp_mode(struct net_device *dev, u32 flags)
9020 {
9021 	if (flags & XDP_FLAGS_HW_MODE)
9022 		return XDP_MODE_HW;
9023 	if (flags & XDP_FLAGS_DRV_MODE)
9024 		return XDP_MODE_DRV;
9025 	if (flags & XDP_FLAGS_SKB_MODE)
9026 		return XDP_MODE_SKB;
9027 	return dev->netdev_ops->ndo_bpf ? XDP_MODE_DRV : XDP_MODE_SKB;
9028 }
9029 
dev_xdp_bpf_op(struct net_device * dev,enum bpf_xdp_mode mode)9030 static bpf_op_t dev_xdp_bpf_op(struct net_device *dev, enum bpf_xdp_mode mode)
9031 {
9032 	switch (mode) {
9033 	case XDP_MODE_SKB:
9034 		return generic_xdp_install;
9035 	case XDP_MODE_DRV:
9036 	case XDP_MODE_HW:
9037 		return dev->netdev_ops->ndo_bpf;
9038 	default:
9039 		return NULL;
9040 	}
9041 }
9042 
dev_xdp_link(struct net_device * dev,enum bpf_xdp_mode mode)9043 static struct bpf_xdp_link *dev_xdp_link(struct net_device *dev,
9044 					 enum bpf_xdp_mode mode)
9045 {
9046 	return dev->xdp_state[mode].link;
9047 }
9048 
dev_xdp_prog(struct net_device * dev,enum bpf_xdp_mode mode)9049 static struct bpf_prog *dev_xdp_prog(struct net_device *dev,
9050 				     enum bpf_xdp_mode mode)
9051 {
9052 	struct bpf_xdp_link *link = dev_xdp_link(dev, mode);
9053 
9054 	if (link)
9055 		return link->link.prog;
9056 	return dev->xdp_state[mode].prog;
9057 }
9058 
dev_xdp_prog_count(struct net_device * dev)9059 u8 dev_xdp_prog_count(struct net_device *dev)
9060 {
9061 	u8 count = 0;
9062 	int i;
9063 
9064 	for (i = 0; i < __MAX_XDP_MODE; i++)
9065 		if (dev->xdp_state[i].prog || dev->xdp_state[i].link)
9066 			count++;
9067 	return count;
9068 }
9069 EXPORT_SYMBOL_GPL(dev_xdp_prog_count);
9070 
dev_xdp_prog_id(struct net_device * dev,enum bpf_xdp_mode mode)9071 u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode)
9072 {
9073 	struct bpf_prog *prog = dev_xdp_prog(dev, mode);
9074 
9075 	return prog ? prog->aux->id : 0;
9076 }
9077 
dev_xdp_set_link(struct net_device * dev,enum bpf_xdp_mode mode,struct bpf_xdp_link * link)9078 static void dev_xdp_set_link(struct net_device *dev, enum bpf_xdp_mode mode,
9079 			     struct bpf_xdp_link *link)
9080 {
9081 	dev->xdp_state[mode].link = link;
9082 	dev->xdp_state[mode].prog = NULL;
9083 }
9084 
dev_xdp_set_prog(struct net_device * dev,enum bpf_xdp_mode mode,struct bpf_prog * prog)9085 static void dev_xdp_set_prog(struct net_device *dev, enum bpf_xdp_mode mode,
9086 			     struct bpf_prog *prog)
9087 {
9088 	dev->xdp_state[mode].link = NULL;
9089 	dev->xdp_state[mode].prog = prog;
9090 }
9091 
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)9092 static int dev_xdp_install(struct net_device *dev, enum bpf_xdp_mode mode,
9093 			   bpf_op_t bpf_op, struct netlink_ext_ack *extack,
9094 			   u32 flags, struct bpf_prog *prog)
9095 {
9096 	struct netdev_bpf xdp;
9097 	int err;
9098 
9099 	memset(&xdp, 0, sizeof(xdp));
9100 	xdp.command = mode == XDP_MODE_HW ? XDP_SETUP_PROG_HW : XDP_SETUP_PROG;
9101 	xdp.extack = extack;
9102 	xdp.flags = flags;
9103 	xdp.prog = prog;
9104 
9105 	/* Drivers assume refcnt is already incremented (i.e, prog pointer is
9106 	 * "moved" into driver), so they don't increment it on their own, but
9107 	 * they do decrement refcnt when program is detached or replaced.
9108 	 * Given net_device also owns link/prog, we need to bump refcnt here
9109 	 * to prevent drivers from underflowing it.
9110 	 */
9111 	if (prog)
9112 		bpf_prog_inc(prog);
9113 	err = bpf_op(dev, &xdp);
9114 	if (err) {
9115 		if (prog)
9116 			bpf_prog_put(prog);
9117 		return err;
9118 	}
9119 
9120 	if (mode != XDP_MODE_HW)
9121 		bpf_prog_change_xdp(dev_xdp_prog(dev, mode), prog);
9122 
9123 	return 0;
9124 }
9125 
dev_xdp_uninstall(struct net_device * dev)9126 static void dev_xdp_uninstall(struct net_device *dev)
9127 {
9128 	struct bpf_xdp_link *link;
9129 	struct bpf_prog *prog;
9130 	enum bpf_xdp_mode mode;
9131 	bpf_op_t bpf_op;
9132 
9133 	ASSERT_RTNL();
9134 
9135 	for (mode = XDP_MODE_SKB; mode < __MAX_XDP_MODE; mode++) {
9136 		prog = dev_xdp_prog(dev, mode);
9137 		if (!prog)
9138 			continue;
9139 
9140 		bpf_op = dev_xdp_bpf_op(dev, mode);
9141 		if (!bpf_op)
9142 			continue;
9143 
9144 		WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9145 
9146 		/* auto-detach link from net device */
9147 		link = dev_xdp_link(dev, mode);
9148 		if (link)
9149 			link->dev = NULL;
9150 		else
9151 			bpf_prog_put(prog);
9152 
9153 		dev_xdp_set_link(dev, mode, NULL);
9154 	}
9155 }
9156 
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)9157 static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack,
9158 			  struct bpf_xdp_link *link, struct bpf_prog *new_prog,
9159 			  struct bpf_prog *old_prog, u32 flags)
9160 {
9161 	unsigned int num_modes = hweight32(flags & XDP_FLAGS_MODES);
9162 	struct bpf_prog *cur_prog;
9163 	struct net_device *upper;
9164 	struct list_head *iter;
9165 	enum bpf_xdp_mode mode;
9166 	bpf_op_t bpf_op;
9167 	int err;
9168 
9169 	ASSERT_RTNL();
9170 
9171 	/* either link or prog attachment, never both */
9172 	if (link && (new_prog || old_prog))
9173 		return -EINVAL;
9174 	/* link supports only XDP mode flags */
9175 	if (link && (flags & ~XDP_FLAGS_MODES)) {
9176 		NL_SET_ERR_MSG(extack, "Invalid XDP flags for BPF link attachment");
9177 		return -EINVAL;
9178 	}
9179 	/* just one XDP mode bit should be set, zero defaults to drv/skb mode */
9180 	if (num_modes > 1) {
9181 		NL_SET_ERR_MSG(extack, "Only one XDP mode flag can be set");
9182 		return -EINVAL;
9183 	}
9184 	/* avoid ambiguity if offload + drv/skb mode progs are both loaded */
9185 	if (!num_modes && dev_xdp_prog_count(dev) > 1) {
9186 		NL_SET_ERR_MSG(extack,
9187 			       "More than one program loaded, unset mode is ambiguous");
9188 		return -EINVAL;
9189 	}
9190 	/* old_prog != NULL implies XDP_FLAGS_REPLACE is set */
9191 	if (old_prog && !(flags & XDP_FLAGS_REPLACE)) {
9192 		NL_SET_ERR_MSG(extack, "XDP_FLAGS_REPLACE is not specified");
9193 		return -EINVAL;
9194 	}
9195 
9196 	mode = dev_xdp_mode(dev, flags);
9197 	/* can't replace attached link */
9198 	if (dev_xdp_link(dev, mode)) {
9199 		NL_SET_ERR_MSG(extack, "Can't replace active BPF XDP link");
9200 		return -EBUSY;
9201 	}
9202 
9203 	/* don't allow if an upper device already has a program */
9204 	netdev_for_each_upper_dev_rcu(dev, upper, iter) {
9205 		if (dev_xdp_prog_count(upper) > 0) {
9206 			NL_SET_ERR_MSG(extack, "Cannot attach when an upper device already has a program");
9207 			return -EEXIST;
9208 		}
9209 	}
9210 
9211 	cur_prog = dev_xdp_prog(dev, mode);
9212 	/* can't replace attached prog with link */
9213 	if (link && cur_prog) {
9214 		NL_SET_ERR_MSG(extack, "Can't replace active XDP program with BPF link");
9215 		return -EBUSY;
9216 	}
9217 	if ((flags & XDP_FLAGS_REPLACE) && cur_prog != old_prog) {
9218 		NL_SET_ERR_MSG(extack, "Active program does not match expected");
9219 		return -EEXIST;
9220 	}
9221 
9222 	/* put effective new program into new_prog */
9223 	if (link)
9224 		new_prog = link->link.prog;
9225 
9226 	if (new_prog) {
9227 		bool offload = mode == XDP_MODE_HW;
9228 		enum bpf_xdp_mode other_mode = mode == XDP_MODE_SKB
9229 					       ? XDP_MODE_DRV : XDP_MODE_SKB;
9230 
9231 		if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && cur_prog) {
9232 			NL_SET_ERR_MSG(extack, "XDP program already attached");
9233 			return -EBUSY;
9234 		}
9235 		if (!offload && dev_xdp_prog(dev, other_mode)) {
9236 			NL_SET_ERR_MSG(extack, "Native and generic XDP can't be active at the same time");
9237 			return -EEXIST;
9238 		}
9239 		if (!offload && bpf_prog_is_dev_bound(new_prog->aux)) {
9240 			NL_SET_ERR_MSG(extack, "Using device-bound program without HW_MODE flag is not supported");
9241 			return -EINVAL;
9242 		}
9243 		if (new_prog->expected_attach_type == BPF_XDP_DEVMAP) {
9244 			NL_SET_ERR_MSG(extack, "BPF_XDP_DEVMAP programs can not be attached to a device");
9245 			return -EINVAL;
9246 		}
9247 		if (new_prog->expected_attach_type == BPF_XDP_CPUMAP) {
9248 			NL_SET_ERR_MSG(extack, "BPF_XDP_CPUMAP programs can not be attached to a device");
9249 			return -EINVAL;
9250 		}
9251 	}
9252 
9253 	/* don't call drivers if the effective program didn't change */
9254 	if (new_prog != cur_prog) {
9255 		bpf_op = dev_xdp_bpf_op(dev, mode);
9256 		if (!bpf_op) {
9257 			NL_SET_ERR_MSG(extack, "Underlying driver does not support XDP in native mode");
9258 			return -EOPNOTSUPP;
9259 		}
9260 
9261 		err = dev_xdp_install(dev, mode, bpf_op, extack, flags, new_prog);
9262 		if (err)
9263 			return err;
9264 	}
9265 
9266 	if (link)
9267 		dev_xdp_set_link(dev, mode, link);
9268 	else
9269 		dev_xdp_set_prog(dev, mode, new_prog);
9270 	if (cur_prog)
9271 		bpf_prog_put(cur_prog);
9272 
9273 	return 0;
9274 }
9275 
dev_xdp_attach_link(struct net_device * dev,struct netlink_ext_ack * extack,struct bpf_xdp_link * link)9276 static int dev_xdp_attach_link(struct net_device *dev,
9277 			       struct netlink_ext_ack *extack,
9278 			       struct bpf_xdp_link *link)
9279 {
9280 	return dev_xdp_attach(dev, extack, link, NULL, NULL, link->flags);
9281 }
9282 
dev_xdp_detach_link(struct net_device * dev,struct netlink_ext_ack * extack,struct bpf_xdp_link * link)9283 static int dev_xdp_detach_link(struct net_device *dev,
9284 			       struct netlink_ext_ack *extack,
9285 			       struct bpf_xdp_link *link)
9286 {
9287 	enum bpf_xdp_mode mode;
9288 	bpf_op_t bpf_op;
9289 
9290 	ASSERT_RTNL();
9291 
9292 	mode = dev_xdp_mode(dev, link->flags);
9293 	if (dev_xdp_link(dev, mode) != link)
9294 		return -EINVAL;
9295 
9296 	bpf_op = dev_xdp_bpf_op(dev, mode);
9297 	WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9298 	dev_xdp_set_link(dev, mode, NULL);
9299 	return 0;
9300 }
9301 
bpf_xdp_link_release(struct bpf_link * link)9302 static void bpf_xdp_link_release(struct bpf_link *link)
9303 {
9304 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9305 
9306 	rtnl_lock();
9307 
9308 	/* if racing with net_device's tear down, xdp_link->dev might be
9309 	 * already NULL, in which case link was already auto-detached
9310 	 */
9311 	if (xdp_link->dev) {
9312 		WARN_ON(dev_xdp_detach_link(xdp_link->dev, NULL, xdp_link));
9313 		xdp_link->dev = NULL;
9314 	}
9315 
9316 	rtnl_unlock();
9317 }
9318 
bpf_xdp_link_detach(struct bpf_link * link)9319 static int bpf_xdp_link_detach(struct bpf_link *link)
9320 {
9321 	bpf_xdp_link_release(link);
9322 	return 0;
9323 }
9324 
bpf_xdp_link_dealloc(struct bpf_link * link)9325 static void bpf_xdp_link_dealloc(struct bpf_link *link)
9326 {
9327 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9328 
9329 	kfree(xdp_link);
9330 }
9331 
bpf_xdp_link_show_fdinfo(const struct bpf_link * link,struct seq_file * seq)9332 static void bpf_xdp_link_show_fdinfo(const struct bpf_link *link,
9333 				     struct seq_file *seq)
9334 {
9335 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9336 	u32 ifindex = 0;
9337 
9338 	rtnl_lock();
9339 	if (xdp_link->dev)
9340 		ifindex = xdp_link->dev->ifindex;
9341 	rtnl_unlock();
9342 
9343 	seq_printf(seq, "ifindex:\t%u\n", ifindex);
9344 }
9345 
bpf_xdp_link_fill_link_info(const struct bpf_link * link,struct bpf_link_info * info)9346 static int bpf_xdp_link_fill_link_info(const struct bpf_link *link,
9347 				       struct bpf_link_info *info)
9348 {
9349 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9350 	u32 ifindex = 0;
9351 
9352 	rtnl_lock();
9353 	if (xdp_link->dev)
9354 		ifindex = xdp_link->dev->ifindex;
9355 	rtnl_unlock();
9356 
9357 	info->xdp.ifindex = ifindex;
9358 	return 0;
9359 }
9360 
bpf_xdp_link_update(struct bpf_link * link,struct bpf_prog * new_prog,struct bpf_prog * old_prog)9361 static int bpf_xdp_link_update(struct bpf_link *link, struct bpf_prog *new_prog,
9362 			       struct bpf_prog *old_prog)
9363 {
9364 	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9365 	enum bpf_xdp_mode mode;
9366 	bpf_op_t bpf_op;
9367 	int err = 0;
9368 
9369 	rtnl_lock();
9370 
9371 	/* link might have been auto-released already, so fail */
9372 	if (!xdp_link->dev) {
9373 		err = -ENOLINK;
9374 		goto out_unlock;
9375 	}
9376 
9377 	if (old_prog && link->prog != old_prog) {
9378 		err = -EPERM;
9379 		goto out_unlock;
9380 	}
9381 	old_prog = link->prog;
9382 	if (old_prog->type != new_prog->type ||
9383 	    old_prog->expected_attach_type != new_prog->expected_attach_type) {
9384 		err = -EINVAL;
9385 		goto out_unlock;
9386 	}
9387 
9388 	if (old_prog == new_prog) {
9389 		/* no-op, don't disturb drivers */
9390 		bpf_prog_put(new_prog);
9391 		goto out_unlock;
9392 	}
9393 
9394 	mode = dev_xdp_mode(xdp_link->dev, xdp_link->flags);
9395 	bpf_op = dev_xdp_bpf_op(xdp_link->dev, mode);
9396 	err = dev_xdp_install(xdp_link->dev, mode, bpf_op, NULL,
9397 			      xdp_link->flags, new_prog);
9398 	if (err)
9399 		goto out_unlock;
9400 
9401 	old_prog = xchg(&link->prog, new_prog);
9402 	bpf_prog_put(old_prog);
9403 
9404 out_unlock:
9405 	rtnl_unlock();
9406 	return err;
9407 }
9408 
9409 static const struct bpf_link_ops bpf_xdp_link_lops = {
9410 	.release = bpf_xdp_link_release,
9411 	.dealloc = bpf_xdp_link_dealloc,
9412 	.detach = bpf_xdp_link_detach,
9413 	.show_fdinfo = bpf_xdp_link_show_fdinfo,
9414 	.fill_link_info = bpf_xdp_link_fill_link_info,
9415 	.update_prog = bpf_xdp_link_update,
9416 };
9417 
bpf_xdp_link_attach(const union bpf_attr * attr,struct bpf_prog * prog)9418 int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
9419 {
9420 	struct net *net = current->nsproxy->net_ns;
9421 	struct bpf_link_primer link_primer;
9422 	struct bpf_xdp_link *link;
9423 	struct net_device *dev;
9424 	int err, fd;
9425 
9426 	rtnl_lock();
9427 	dev = dev_get_by_index(net, attr->link_create.target_ifindex);
9428 	if (!dev) {
9429 		rtnl_unlock();
9430 		return -EINVAL;
9431 	}
9432 
9433 	link = kzalloc(sizeof(*link), GFP_USER);
9434 	if (!link) {
9435 		err = -ENOMEM;
9436 		goto unlock;
9437 	}
9438 
9439 	bpf_link_init(&link->link, BPF_LINK_TYPE_XDP, &bpf_xdp_link_lops, prog);
9440 	link->dev = dev;
9441 	link->flags = attr->link_create.flags;
9442 
9443 	err = bpf_link_prime(&link->link, &link_primer);
9444 	if (err) {
9445 		kfree(link);
9446 		goto unlock;
9447 	}
9448 
9449 	err = dev_xdp_attach_link(dev, NULL, link);
9450 	rtnl_unlock();
9451 
9452 	if (err) {
9453 		link->dev = NULL;
9454 		bpf_link_cleanup(&link_primer);
9455 		goto out_put_dev;
9456 	}
9457 
9458 	fd = bpf_link_settle(&link_primer);
9459 	/* link itself doesn't hold dev's refcnt to not complicate shutdown */
9460 	dev_put(dev);
9461 	return fd;
9462 
9463 unlock:
9464 	rtnl_unlock();
9465 
9466 out_put_dev:
9467 	dev_put(dev);
9468 	return err;
9469 }
9470 
9471 /**
9472  *	dev_change_xdp_fd - set or clear a bpf program for a device rx path
9473  *	@dev: device
9474  *	@extack: netlink extended ack
9475  *	@fd: new program fd or negative value to clear
9476  *	@expected_fd: old program fd that userspace expects to replace or clear
9477  *	@flags: xdp-related flags
9478  *
9479  *	Set or clear a bpf program for a device
9480  */
dev_change_xdp_fd(struct net_device * dev,struct netlink_ext_ack * extack,int fd,int expected_fd,u32 flags)9481 int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
9482 		      int fd, int expected_fd, u32 flags)
9483 {
9484 	enum bpf_xdp_mode mode = dev_xdp_mode(dev, flags);
9485 	struct bpf_prog *new_prog = NULL, *old_prog = NULL;
9486 	int err;
9487 
9488 	ASSERT_RTNL();
9489 
9490 	if (fd >= 0) {
9491 		new_prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP,
9492 						 mode != XDP_MODE_SKB);
9493 		if (IS_ERR(new_prog))
9494 			return PTR_ERR(new_prog);
9495 	}
9496 
9497 	if (expected_fd >= 0) {
9498 		old_prog = bpf_prog_get_type_dev(expected_fd, BPF_PROG_TYPE_XDP,
9499 						 mode != XDP_MODE_SKB);
9500 		if (IS_ERR(old_prog)) {
9501 			err = PTR_ERR(old_prog);
9502 			old_prog = NULL;
9503 			goto err_out;
9504 		}
9505 	}
9506 
9507 	err = dev_xdp_attach(dev, extack, NULL, new_prog, old_prog, flags);
9508 
9509 err_out:
9510 	if (err && new_prog)
9511 		bpf_prog_put(new_prog);
9512 	if (old_prog)
9513 		bpf_prog_put(old_prog);
9514 	return err;
9515 }
9516 
9517 /**
9518  *	dev_new_index	-	allocate an ifindex
9519  *	@net: the applicable net namespace
9520  *
9521  *	Returns a suitable unique value for a new device interface
9522  *	number.  The caller must hold the rtnl semaphore or the
9523  *	dev_base_lock to be sure it remains unique.
9524  */
dev_new_index(struct net * net)9525 static int dev_new_index(struct net *net)
9526 {
9527 	int ifindex = net->ifindex;
9528 
9529 	for (;;) {
9530 		if (++ifindex <= 0)
9531 			ifindex = 1;
9532 		if (!__dev_get_by_index(net, ifindex))
9533 			return net->ifindex = ifindex;
9534 	}
9535 }
9536 
9537 /* Delayed registration/unregisteration */
9538 LIST_HEAD(net_todo_list);
9539 DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq);
9540 
net_set_todo(struct net_device * dev)9541 static void net_set_todo(struct net_device *dev)
9542 {
9543 	list_add_tail(&dev->todo_list, &net_todo_list);
9544 	atomic_inc(&dev_net(dev)->dev_unreg_count);
9545 }
9546 
netdev_sync_upper_features(struct net_device * lower,struct net_device * upper,netdev_features_t features)9547 static netdev_features_t netdev_sync_upper_features(struct net_device *lower,
9548 	struct net_device *upper, netdev_features_t features)
9549 {
9550 	netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9551 	netdev_features_t feature;
9552 	int feature_bit;
9553 
9554 	for_each_netdev_feature(upper_disables, feature_bit) {
9555 		feature = __NETIF_F_BIT(feature_bit);
9556 		if (!(upper->wanted_features & feature)
9557 		    && (features & feature)) {
9558 			netdev_dbg(lower, "Dropping feature %pNF, upper dev %s has it off.\n",
9559 				   &feature, upper->name);
9560 			features &= ~feature;
9561 		}
9562 	}
9563 
9564 	return features;
9565 }
9566 
netdev_sync_lower_features(struct net_device * upper,struct net_device * lower,netdev_features_t features)9567 static void netdev_sync_lower_features(struct net_device *upper,
9568 	struct net_device *lower, netdev_features_t features)
9569 {
9570 	netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9571 	netdev_features_t feature;
9572 	int feature_bit;
9573 
9574 	for_each_netdev_feature(upper_disables, feature_bit) {
9575 		feature = __NETIF_F_BIT(feature_bit);
9576 		if (!(features & feature) && (lower->features & feature)) {
9577 			netdev_dbg(upper, "Disabling feature %pNF on lower dev %s.\n",
9578 				   &feature, lower->name);
9579 			lower->wanted_features &= ~feature;
9580 			__netdev_update_features(lower);
9581 
9582 			if (unlikely(lower->features & feature))
9583 				netdev_WARN(upper, "failed to disable %pNF on %s!\n",
9584 					    &feature, lower->name);
9585 			else
9586 				netdev_features_change(lower);
9587 		}
9588 	}
9589 }
9590 
netdev_fix_features(struct net_device * dev,netdev_features_t features)9591 static netdev_features_t netdev_fix_features(struct net_device *dev,
9592 	netdev_features_t features)
9593 {
9594 	/* Fix illegal checksum combinations */
9595 	if ((features & NETIF_F_HW_CSUM) &&
9596 	    (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
9597 		netdev_warn(dev, "mixed HW and IP checksum settings.\n");
9598 		features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
9599 	}
9600 
9601 	/* TSO requires that SG is present as well. */
9602 	if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
9603 		netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
9604 		features &= ~NETIF_F_ALL_TSO;
9605 	}
9606 
9607 	if ((features & NETIF_F_TSO) && !(features & NETIF_F_HW_CSUM) &&
9608 					!(features & NETIF_F_IP_CSUM)) {
9609 		netdev_dbg(dev, "Dropping TSO features since no CSUM feature.\n");
9610 		features &= ~NETIF_F_TSO;
9611 		features &= ~NETIF_F_TSO_ECN;
9612 	}
9613 
9614 	if ((features & NETIF_F_TSO6) && !(features & NETIF_F_HW_CSUM) &&
9615 					 !(features & NETIF_F_IPV6_CSUM)) {
9616 		netdev_dbg(dev, "Dropping TSO6 features since no CSUM feature.\n");
9617 		features &= ~NETIF_F_TSO6;
9618 	}
9619 
9620 	/* TSO with IPv4 ID mangling requires IPv4 TSO be enabled */
9621 	if ((features & NETIF_F_TSO_MANGLEID) && !(features & NETIF_F_TSO))
9622 		features &= ~NETIF_F_TSO_MANGLEID;
9623 
9624 	/* TSO ECN requires that TSO is present as well. */
9625 	if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
9626 		features &= ~NETIF_F_TSO_ECN;
9627 
9628 	/* Software GSO depends on SG. */
9629 	if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
9630 		netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
9631 		features &= ~NETIF_F_GSO;
9632 	}
9633 
9634 	/* GSO partial features require GSO partial be set */
9635 	if ((features & dev->gso_partial_features) &&
9636 	    !(features & NETIF_F_GSO_PARTIAL)) {
9637 		netdev_dbg(dev,
9638 			   "Dropping partially supported GSO features since no GSO partial.\n");
9639 		features &= ~dev->gso_partial_features;
9640 	}
9641 
9642 	if (!(features & NETIF_F_RXCSUM)) {
9643 		/* NETIF_F_GRO_HW implies doing RXCSUM since every packet
9644 		 * successfully merged by hardware must also have the
9645 		 * checksum verified by hardware.  If the user does not
9646 		 * want to enable RXCSUM, logically, we should disable GRO_HW.
9647 		 */
9648 		if (features & NETIF_F_GRO_HW) {
9649 			netdev_dbg(dev, "Dropping NETIF_F_GRO_HW since no RXCSUM feature.\n");
9650 			features &= ~NETIF_F_GRO_HW;
9651 		}
9652 	}
9653 
9654 	/* LRO/HW-GRO features cannot be combined with RX-FCS */
9655 	if (features & NETIF_F_RXFCS) {
9656 		if (features & NETIF_F_LRO) {
9657 			netdev_dbg(dev, "Dropping LRO feature since RX-FCS is requested.\n");
9658 			features &= ~NETIF_F_LRO;
9659 		}
9660 
9661 		if (features & NETIF_F_GRO_HW) {
9662 			netdev_dbg(dev, "Dropping HW-GRO feature since RX-FCS is requested.\n");
9663 			features &= ~NETIF_F_GRO_HW;
9664 		}
9665 	}
9666 
9667 	if ((features & NETIF_F_GRO_HW) && (features & NETIF_F_LRO)) {
9668 		netdev_dbg(dev, "Dropping LRO feature since HW-GRO is requested.\n");
9669 		features &= ~NETIF_F_LRO;
9670 	}
9671 
9672 	if (features & NETIF_F_HW_TLS_TX) {
9673 		bool ip_csum = (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) ==
9674 			(NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM);
9675 		bool hw_csum = features & NETIF_F_HW_CSUM;
9676 
9677 		if (!ip_csum && !hw_csum) {
9678 			netdev_dbg(dev, "Dropping TLS TX HW offload feature since no CSUM feature.\n");
9679 			features &= ~NETIF_F_HW_TLS_TX;
9680 		}
9681 	}
9682 
9683 	if ((features & NETIF_F_HW_TLS_RX) && !(features & NETIF_F_RXCSUM)) {
9684 		netdev_dbg(dev, "Dropping TLS RX HW offload feature since no RXCSUM feature.\n");
9685 		features &= ~NETIF_F_HW_TLS_RX;
9686 	}
9687 
9688 	return features;
9689 }
9690 
__netdev_update_features(struct net_device * dev)9691 int __netdev_update_features(struct net_device *dev)
9692 {
9693 	struct net_device *upper, *lower;
9694 	netdev_features_t features;
9695 	struct list_head *iter;
9696 	int err = -1;
9697 
9698 	ASSERT_RTNL();
9699 
9700 	features = netdev_get_wanted_features(dev);
9701 
9702 	if (dev->netdev_ops->ndo_fix_features)
9703 		features = dev->netdev_ops->ndo_fix_features(dev, features);
9704 
9705 	/* driver might be less strict about feature dependencies */
9706 	features = netdev_fix_features(dev, features);
9707 
9708 	/* some features can't be enabled if they're off on an upper device */
9709 	netdev_for_each_upper_dev_rcu(dev, upper, iter)
9710 		features = netdev_sync_upper_features(dev, upper, features);
9711 
9712 	if (dev->features == features)
9713 		goto sync_lower;
9714 
9715 	netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
9716 		&dev->features, &features);
9717 
9718 	if (dev->netdev_ops->ndo_set_features)
9719 		err = dev->netdev_ops->ndo_set_features(dev, features);
9720 	else
9721 		err = 0;
9722 
9723 	if (unlikely(err < 0)) {
9724 		netdev_err(dev,
9725 			"set_features() failed (%d); wanted %pNF, left %pNF\n",
9726 			err, &features, &dev->features);
9727 		/* return non-0 since some features might have changed and
9728 		 * it's better to fire a spurious notification than miss it
9729 		 */
9730 		return -1;
9731 	}
9732 
9733 sync_lower:
9734 	/* some features must be disabled on lower devices when disabled
9735 	 * on an upper device (think: bonding master or bridge)
9736 	 */
9737 	netdev_for_each_lower_dev(dev, lower, iter)
9738 		netdev_sync_lower_features(dev, lower, features);
9739 
9740 	if (!err) {
9741 		netdev_features_t diff = features ^ dev->features;
9742 
9743 		if (diff & NETIF_F_RX_UDP_TUNNEL_PORT) {
9744 			/* udp_tunnel_{get,drop}_rx_info both need
9745 			 * NETIF_F_RX_UDP_TUNNEL_PORT enabled on the
9746 			 * device, or they won't do anything.
9747 			 * Thus we need to update dev->features
9748 			 * *before* calling udp_tunnel_get_rx_info,
9749 			 * but *after* calling udp_tunnel_drop_rx_info.
9750 			 */
9751 			if (features & NETIF_F_RX_UDP_TUNNEL_PORT) {
9752 				dev->features = features;
9753 				udp_tunnel_get_rx_info(dev);
9754 			} else {
9755 				udp_tunnel_drop_rx_info(dev);
9756 			}
9757 		}
9758 
9759 		if (diff & NETIF_F_HW_VLAN_CTAG_FILTER) {
9760 			if (features & NETIF_F_HW_VLAN_CTAG_FILTER) {
9761 				dev->features = features;
9762 				err |= vlan_get_rx_ctag_filter_info(dev);
9763 			} else {
9764 				vlan_drop_rx_ctag_filter_info(dev);
9765 			}
9766 		}
9767 
9768 		if (diff & NETIF_F_HW_VLAN_STAG_FILTER) {
9769 			if (features & NETIF_F_HW_VLAN_STAG_FILTER) {
9770 				dev->features = features;
9771 				err |= vlan_get_rx_stag_filter_info(dev);
9772 			} else {
9773 				vlan_drop_rx_stag_filter_info(dev);
9774 			}
9775 		}
9776 
9777 		dev->features = features;
9778 	}
9779 
9780 	return err < 0 ? 0 : 1;
9781 }
9782 
9783 /**
9784  *	netdev_update_features - recalculate device features
9785  *	@dev: the device to check
9786  *
9787  *	Recalculate dev->features set and send notifications if it
9788  *	has changed. Should be called after driver or hardware dependent
9789  *	conditions might have changed that influence the features.
9790  */
netdev_update_features(struct net_device * dev)9791 void netdev_update_features(struct net_device *dev)
9792 {
9793 	if (__netdev_update_features(dev))
9794 		netdev_features_change(dev);
9795 }
9796 EXPORT_SYMBOL(netdev_update_features);
9797 
9798 /**
9799  *	netdev_change_features - recalculate device features
9800  *	@dev: the device to check
9801  *
9802  *	Recalculate dev->features set and send notifications even
9803  *	if they have not changed. Should be called instead of
9804  *	netdev_update_features() if also dev->vlan_features might
9805  *	have changed to allow the changes to be propagated to stacked
9806  *	VLAN devices.
9807  */
netdev_change_features(struct net_device * dev)9808 void netdev_change_features(struct net_device *dev)
9809 {
9810 	__netdev_update_features(dev);
9811 	netdev_features_change(dev);
9812 }
9813 EXPORT_SYMBOL(netdev_change_features);
9814 
9815 /**
9816  *	netif_stacked_transfer_operstate -	transfer operstate
9817  *	@rootdev: the root or lower level device to transfer state from
9818  *	@dev: the device to transfer operstate to
9819  *
9820  *	Transfer operational state from root to device. This is normally
9821  *	called when a stacking relationship exists between the root
9822  *	device and the device(a leaf device).
9823  */
netif_stacked_transfer_operstate(const struct net_device * rootdev,struct net_device * dev)9824 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
9825 					struct net_device *dev)
9826 {
9827 	if (rootdev->operstate == IF_OPER_DORMANT)
9828 		netif_dormant_on(dev);
9829 	else
9830 		netif_dormant_off(dev);
9831 
9832 	if (rootdev->operstate == IF_OPER_TESTING)
9833 		netif_testing_on(dev);
9834 	else
9835 		netif_testing_off(dev);
9836 
9837 	if (netif_carrier_ok(rootdev))
9838 		netif_carrier_on(dev);
9839 	else
9840 		netif_carrier_off(dev);
9841 }
9842 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
9843 
netif_alloc_rx_queues(struct net_device * dev)9844 static int netif_alloc_rx_queues(struct net_device *dev)
9845 {
9846 	unsigned int i, count = dev->num_rx_queues;
9847 	struct netdev_rx_queue *rx;
9848 	size_t sz = count * sizeof(*rx);
9849 	int err = 0;
9850 
9851 	BUG_ON(count < 1);
9852 
9853 	rx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
9854 	if (!rx)
9855 		return -ENOMEM;
9856 
9857 	dev->_rx = rx;
9858 
9859 	for (i = 0; i < count; i++) {
9860 		rx[i].dev = dev;
9861 
9862 		/* XDP RX-queue setup */
9863 		err = xdp_rxq_info_reg(&rx[i].xdp_rxq, dev, i, 0);
9864 		if (err < 0)
9865 			goto err_rxq_info;
9866 	}
9867 	return 0;
9868 
9869 err_rxq_info:
9870 	/* Rollback successful reg's and free other resources */
9871 	while (i--)
9872 		xdp_rxq_info_unreg(&rx[i].xdp_rxq);
9873 	kvfree(dev->_rx);
9874 	dev->_rx = NULL;
9875 	return err;
9876 }
9877 
netif_free_rx_queues(struct net_device * dev)9878 static void netif_free_rx_queues(struct net_device *dev)
9879 {
9880 	unsigned int i, count = dev->num_rx_queues;
9881 
9882 	/* netif_alloc_rx_queues alloc failed, resources have been unreg'ed */
9883 	if (!dev->_rx)
9884 		return;
9885 
9886 	for (i = 0; i < count; i++)
9887 		xdp_rxq_info_unreg(&dev->_rx[i].xdp_rxq);
9888 
9889 	kvfree(dev->_rx);
9890 }
9891 
netdev_init_one_queue(struct net_device * dev,struct netdev_queue * queue,void * _unused)9892 static void netdev_init_one_queue(struct net_device *dev,
9893 				  struct netdev_queue *queue, void *_unused)
9894 {
9895 	/* Initialize queue lock */
9896 	spin_lock_init(&queue->_xmit_lock);
9897 	netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
9898 	queue->xmit_lock_owner = -1;
9899 	netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
9900 	queue->dev = dev;
9901 #ifdef CONFIG_BQL
9902 	dql_init(&queue->dql, HZ);
9903 #endif
9904 }
9905 
netif_free_tx_queues(struct net_device * dev)9906 static void netif_free_tx_queues(struct net_device *dev)
9907 {
9908 	kvfree(dev->_tx);
9909 }
9910 
netif_alloc_netdev_queues(struct net_device * dev)9911 static int netif_alloc_netdev_queues(struct net_device *dev)
9912 {
9913 	unsigned int count = dev->num_tx_queues;
9914 	struct netdev_queue *tx;
9915 	size_t sz = count * sizeof(*tx);
9916 
9917 	if (count < 1 || count > 0xffff)
9918 		return -EINVAL;
9919 
9920 	tx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
9921 	if (!tx)
9922 		return -ENOMEM;
9923 
9924 	dev->_tx = tx;
9925 
9926 	netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
9927 	spin_lock_init(&dev->tx_global_lock);
9928 
9929 	return 0;
9930 }
9931 
netif_tx_stop_all_queues(struct net_device * dev)9932 void netif_tx_stop_all_queues(struct net_device *dev)
9933 {
9934 	unsigned int i;
9935 
9936 	for (i = 0; i < dev->num_tx_queues; i++) {
9937 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
9938 
9939 		netif_tx_stop_queue(txq);
9940 	}
9941 }
9942 EXPORT_SYMBOL(netif_tx_stop_all_queues);
9943 
9944 /**
9945  * register_netdevice() - register a network device
9946  * @dev: device to register
9947  *
9948  * Take a prepared network device structure and make it externally accessible.
9949  * A %NETDEV_REGISTER message is sent to the netdev notifier chain.
9950  * Callers must hold the rtnl lock - you may want register_netdev()
9951  * instead of this.
9952  */
register_netdevice(struct net_device * dev)9953 int register_netdevice(struct net_device *dev)
9954 {
9955 	int ret;
9956 	struct net *net = dev_net(dev);
9957 
9958 	BUILD_BUG_ON(sizeof(netdev_features_t) * BITS_PER_BYTE <
9959 		     NETDEV_FEATURE_COUNT);
9960 	BUG_ON(dev_boot_phase);
9961 	ASSERT_RTNL();
9962 
9963 	might_sleep();
9964 
9965 	/* When net_device's are persistent, this will be fatal. */
9966 	BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
9967 	BUG_ON(!net);
9968 
9969 	ret = ethtool_check_ops(dev->ethtool_ops);
9970 	if (ret)
9971 		return ret;
9972 
9973 	spin_lock_init(&dev->addr_list_lock);
9974 	netdev_set_addr_lockdep_class(dev);
9975 
9976 	ret = dev_get_valid_name(net, dev, dev->name);
9977 	if (ret < 0)
9978 		goto out;
9979 
9980 	ret = -ENOMEM;
9981 	dev->name_node = netdev_name_node_head_alloc(dev);
9982 	if (!dev->name_node)
9983 		goto out;
9984 
9985 	/* Init, if this function is available */
9986 	if (dev->netdev_ops->ndo_init) {
9987 		ret = dev->netdev_ops->ndo_init(dev);
9988 		if (ret) {
9989 			if (ret > 0)
9990 				ret = -EIO;
9991 			goto err_free_name;
9992 		}
9993 	}
9994 
9995 	if (((dev->hw_features | dev->features) &
9996 	     NETIF_F_HW_VLAN_CTAG_FILTER) &&
9997 	    (!dev->netdev_ops->ndo_vlan_rx_add_vid ||
9998 	     !dev->netdev_ops->ndo_vlan_rx_kill_vid)) {
9999 		netdev_WARN(dev, "Buggy VLAN acceleration in driver!\n");
10000 		ret = -EINVAL;
10001 		goto err_uninit;
10002 	}
10003 
10004 	ret = -EBUSY;
10005 	if (!dev->ifindex)
10006 		dev->ifindex = dev_new_index(net);
10007 	else if (__dev_get_by_index(net, dev->ifindex))
10008 		goto err_uninit;
10009 
10010 	/* Transfer changeable features to wanted_features and enable
10011 	 * software offloads (GSO and GRO).
10012 	 */
10013 	dev->hw_features |= (NETIF_F_SOFT_FEATURES | NETIF_F_SOFT_FEATURES_OFF);
10014 	dev->features |= NETIF_F_SOFT_FEATURES;
10015 
10016 	if (dev->udp_tunnel_nic_info) {
10017 		dev->features |= NETIF_F_RX_UDP_TUNNEL_PORT;
10018 		dev->hw_features |= NETIF_F_RX_UDP_TUNNEL_PORT;
10019 	}
10020 
10021 	dev->wanted_features = dev->features & dev->hw_features;
10022 
10023 	if (!(dev->flags & IFF_LOOPBACK))
10024 		dev->hw_features |= NETIF_F_NOCACHE_COPY;
10025 
10026 	/* If IPv4 TCP segmentation offload is supported we should also
10027 	 * allow the device to enable segmenting the frame with the option
10028 	 * of ignoring a static IP ID value.  This doesn't enable the
10029 	 * feature itself but allows the user to enable it later.
10030 	 */
10031 	if (dev->hw_features & NETIF_F_TSO)
10032 		dev->hw_features |= NETIF_F_TSO_MANGLEID;
10033 	if (dev->vlan_features & NETIF_F_TSO)
10034 		dev->vlan_features |= NETIF_F_TSO_MANGLEID;
10035 	if (dev->mpls_features & NETIF_F_TSO)
10036 		dev->mpls_features |= NETIF_F_TSO_MANGLEID;
10037 	if (dev->hw_enc_features & NETIF_F_TSO)
10038 		dev->hw_enc_features |= NETIF_F_TSO_MANGLEID;
10039 
10040 	/* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
10041 	 */
10042 	dev->vlan_features |= NETIF_F_HIGHDMA;
10043 
10044 	/* Make NETIF_F_SG inheritable to tunnel devices.
10045 	 */
10046 	dev->hw_enc_features |= NETIF_F_SG | NETIF_F_GSO_PARTIAL;
10047 
10048 	/* Make NETIF_F_SG inheritable to MPLS.
10049 	 */
10050 	dev->mpls_features |= NETIF_F_SG;
10051 
10052 	ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
10053 	ret = notifier_to_errno(ret);
10054 	if (ret)
10055 		goto err_uninit;
10056 
10057 	ret = netdev_register_kobject(dev);
10058 	write_lock(&dev_base_lock);
10059 	dev->reg_state = ret ? NETREG_UNREGISTERED : NETREG_REGISTERED;
10060 	write_unlock(&dev_base_lock);
10061 	if (ret)
10062 		goto err_uninit;
10063 
10064 	__netdev_update_features(dev);
10065 
10066 	/*
10067 	 *	Default initial state at registry is that the
10068 	 *	device is present.
10069 	 */
10070 
10071 	set_bit(__LINK_STATE_PRESENT, &dev->state);
10072 
10073 	linkwatch_init_dev(dev);
10074 
10075 	dev_init_scheduler(dev);
10076 
10077 	netdev_hold(dev, &dev->dev_registered_tracker, GFP_KERNEL);
10078 	list_netdevice(dev);
10079 
10080 	add_device_randomness(dev->dev_addr, dev->addr_len);
10081 
10082 	/* If the device has permanent device address, driver should
10083 	 * set dev_addr and also addr_assign_type should be set to
10084 	 * NET_ADDR_PERM (default value).
10085 	 */
10086 	if (dev->addr_assign_type == NET_ADDR_PERM)
10087 		memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);
10088 
10089 	/* Notify protocols, that a new device appeared. */
10090 	ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
10091 	ret = notifier_to_errno(ret);
10092 	if (ret) {
10093 		/* Expect explicit free_netdev() on failure */
10094 		dev->needs_free_netdev = false;
10095 		unregister_netdevice_queue(dev, NULL);
10096 		goto out;
10097 	}
10098 	/*
10099 	 *	Prevent userspace races by waiting until the network
10100 	 *	device is fully setup before sending notifications.
10101 	 */
10102 	if (!dev->rtnl_link_ops ||
10103 	    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
10104 		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
10105 
10106 out:
10107 	return ret;
10108 
10109 err_uninit:
10110 	if (dev->netdev_ops->ndo_uninit)
10111 		dev->netdev_ops->ndo_uninit(dev);
10112 	if (dev->priv_destructor)
10113 		dev->priv_destructor(dev);
10114 err_free_name:
10115 	netdev_name_node_free(dev->name_node);
10116 	goto out;
10117 }
10118 EXPORT_SYMBOL(register_netdevice);
10119 
10120 /**
10121  *	init_dummy_netdev	- init a dummy network device for NAPI
10122  *	@dev: device to init
10123  *
10124  *	This takes a network device structure and initialize the minimum
10125  *	amount of fields so it can be used to schedule NAPI polls without
10126  *	registering a full blown interface. This is to be used by drivers
10127  *	that need to tie several hardware interfaces to a single NAPI
10128  *	poll scheduler due to HW limitations.
10129  */
init_dummy_netdev(struct net_device * dev)10130 int init_dummy_netdev(struct net_device *dev)
10131 {
10132 	/* Clear everything. Note we don't initialize spinlocks
10133 	 * are they aren't supposed to be taken by any of the
10134 	 * NAPI code and this dummy netdev is supposed to be
10135 	 * only ever used for NAPI polls
10136 	 */
10137 	memset(dev, 0, sizeof(struct net_device));
10138 
10139 	/* make sure we BUG if trying to hit standard
10140 	 * register/unregister code path
10141 	 */
10142 	dev->reg_state = NETREG_DUMMY;
10143 
10144 	/* NAPI wants this */
10145 	INIT_LIST_HEAD(&dev->napi_list);
10146 
10147 	/* a dummy interface is started by default */
10148 	set_bit(__LINK_STATE_PRESENT, &dev->state);
10149 	set_bit(__LINK_STATE_START, &dev->state);
10150 
10151 	/* napi_busy_loop stats accounting wants this */
10152 	dev_net_set(dev, &init_net);
10153 
10154 	/* Note : We dont allocate pcpu_refcnt for dummy devices,
10155 	 * because users of this 'device' dont need to change
10156 	 * its refcount.
10157 	 */
10158 
10159 	return 0;
10160 }
10161 EXPORT_SYMBOL_GPL(init_dummy_netdev);
10162 
10163 
10164 /**
10165  *	register_netdev	- register a network device
10166  *	@dev: device to register
10167  *
10168  *	Take a completed network device structure and add it to the kernel
10169  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
10170  *	chain. 0 is returned on success. A negative errno code is returned
10171  *	on a failure to set up the device, or if the name is a duplicate.
10172  *
10173  *	This is a wrapper around register_netdevice that takes the rtnl semaphore
10174  *	and expands the device name if you passed a format string to
10175  *	alloc_netdev.
10176  */
register_netdev(struct net_device * dev)10177 int register_netdev(struct net_device *dev)
10178 {
10179 	int err;
10180 
10181 	if (rtnl_lock_killable())
10182 		return -EINTR;
10183 	err = register_netdevice(dev);
10184 	rtnl_unlock();
10185 	return err;
10186 }
10187 EXPORT_SYMBOL(register_netdev);
10188 
netdev_refcnt_read(const struct net_device * dev)10189 int netdev_refcnt_read(const struct net_device *dev)
10190 {
10191 #ifdef CONFIG_PCPU_DEV_REFCNT
10192 	int i, refcnt = 0;
10193 
10194 	for_each_possible_cpu(i)
10195 		refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
10196 	return refcnt;
10197 #else
10198 	return refcount_read(&dev->dev_refcnt);
10199 #endif
10200 }
10201 EXPORT_SYMBOL(netdev_refcnt_read);
10202 
10203 int netdev_unregister_timeout_secs __read_mostly = 10;
10204 
10205 #define WAIT_REFS_MIN_MSECS 1
10206 #define WAIT_REFS_MAX_MSECS 250
10207 /**
10208  * netdev_wait_allrefs_any - wait until all references are gone.
10209  * @list: list of net_devices to wait on
10210  *
10211  * This is called when unregistering network devices.
10212  *
10213  * Any protocol or device that holds a reference should register
10214  * for netdevice notification, and cleanup and put back the
10215  * reference if they receive an UNREGISTER event.
10216  * We can get stuck here if buggy protocols don't correctly
10217  * call dev_put.
10218  */
netdev_wait_allrefs_any(struct list_head * list)10219 static struct net_device *netdev_wait_allrefs_any(struct list_head *list)
10220 {
10221 	unsigned long rebroadcast_time, warning_time;
10222 	struct net_device *dev;
10223 	int wait = 0;
10224 
10225 	rebroadcast_time = warning_time = jiffies;
10226 
10227 	list_for_each_entry(dev, list, todo_list)
10228 		if (netdev_refcnt_read(dev) == 1)
10229 			return dev;
10230 
10231 	while (true) {
10232 		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
10233 			rtnl_lock();
10234 
10235 			/* Rebroadcast unregister notification */
10236 			list_for_each_entry(dev, list, todo_list)
10237 				call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10238 
10239 			__rtnl_unlock();
10240 			rcu_barrier();
10241 			rtnl_lock();
10242 
10243 			list_for_each_entry(dev, list, todo_list)
10244 				if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
10245 					     &dev->state)) {
10246 					/* We must not have linkwatch events
10247 					 * pending on unregister. If this
10248 					 * happens, we simply run the queue
10249 					 * unscheduled, resulting in a noop
10250 					 * for this device.
10251 					 */
10252 					linkwatch_run_queue();
10253 					break;
10254 				}
10255 
10256 			__rtnl_unlock();
10257 
10258 			rebroadcast_time = jiffies;
10259 		}
10260 
10261 		if (!wait) {
10262 			rcu_barrier();
10263 			wait = WAIT_REFS_MIN_MSECS;
10264 		} else {
10265 			msleep(wait);
10266 			wait = min(wait << 1, WAIT_REFS_MAX_MSECS);
10267 		}
10268 
10269 		list_for_each_entry(dev, list, todo_list)
10270 			if (netdev_refcnt_read(dev) == 1)
10271 				return dev;
10272 
10273 		if (time_after(jiffies, warning_time +
10274 			       READ_ONCE(netdev_unregister_timeout_secs) * HZ)) {
10275 			list_for_each_entry(dev, list, todo_list) {
10276 				pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
10277 					 dev->name, netdev_refcnt_read(dev));
10278 				ref_tracker_dir_print(&dev->refcnt_tracker, 10);
10279 			}
10280 
10281 			warning_time = jiffies;
10282 		}
10283 	}
10284 }
10285 
10286 /* The sequence is:
10287  *
10288  *	rtnl_lock();
10289  *	...
10290  *	register_netdevice(x1);
10291  *	register_netdevice(x2);
10292  *	...
10293  *	unregister_netdevice(y1);
10294  *	unregister_netdevice(y2);
10295  *      ...
10296  *	rtnl_unlock();
10297  *	free_netdev(y1);
10298  *	free_netdev(y2);
10299  *
10300  * We are invoked by rtnl_unlock().
10301  * This allows us to deal with problems:
10302  * 1) We can delete sysfs objects which invoke hotplug
10303  *    without deadlocking with linkwatch via keventd.
10304  * 2) Since we run with the RTNL semaphore not held, we can sleep
10305  *    safely in order to wait for the netdev refcnt to drop to zero.
10306  *
10307  * We must not return until all unregister events added during
10308  * the interval the lock was held have been completed.
10309  */
netdev_run_todo(void)10310 void netdev_run_todo(void)
10311 {
10312 	struct net_device *dev, *tmp;
10313 	struct list_head list;
10314 #ifdef CONFIG_LOCKDEP
10315 	struct list_head unlink_list;
10316 
10317 	list_replace_init(&net_unlink_list, &unlink_list);
10318 
10319 	while (!list_empty(&unlink_list)) {
10320 		struct net_device *dev = list_first_entry(&unlink_list,
10321 							  struct net_device,
10322 							  unlink_list);
10323 		list_del_init(&dev->unlink_list);
10324 		dev->nested_level = dev->lower_level - 1;
10325 	}
10326 #endif
10327 
10328 	/* Snapshot list, allow later requests */
10329 	list_replace_init(&net_todo_list, &list);
10330 
10331 	__rtnl_unlock();
10332 
10333 	/* Wait for rcu callbacks to finish before next phase */
10334 	if (!list_empty(&list))
10335 		rcu_barrier();
10336 
10337 	list_for_each_entry_safe(dev, tmp, &list, todo_list) {
10338 		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
10339 			netdev_WARN(dev, "run_todo but not unregistering\n");
10340 			list_del(&dev->todo_list);
10341 			continue;
10342 		}
10343 
10344 		write_lock(&dev_base_lock);
10345 		dev->reg_state = NETREG_UNREGISTERED;
10346 		write_unlock(&dev_base_lock);
10347 		linkwatch_forget_dev(dev);
10348 	}
10349 
10350 	while (!list_empty(&list)) {
10351 		dev = netdev_wait_allrefs_any(&list);
10352 		list_del(&dev->todo_list);
10353 
10354 		/* paranoia */
10355 		BUG_ON(netdev_refcnt_read(dev) != 1);
10356 		BUG_ON(!list_empty(&dev->ptype_all));
10357 		BUG_ON(!list_empty(&dev->ptype_specific));
10358 		WARN_ON(rcu_access_pointer(dev->ip_ptr));
10359 		WARN_ON(rcu_access_pointer(dev->ip6_ptr));
10360 
10361 		if (dev->priv_destructor)
10362 			dev->priv_destructor(dev);
10363 		if (dev->needs_free_netdev)
10364 			free_netdev(dev);
10365 
10366 		if (atomic_dec_and_test(&dev_net(dev)->dev_unreg_count))
10367 			wake_up(&netdev_unregistering_wq);
10368 
10369 		/* Free network device */
10370 		kobject_put(&dev->dev.kobj);
10371 	}
10372 }
10373 
10374 /* Convert net_device_stats to rtnl_link_stats64. rtnl_link_stats64 has
10375  * all the same fields in the same order as net_device_stats, with only
10376  * the type differing, but rtnl_link_stats64 may have additional fields
10377  * at the end for newer counters.
10378  */
netdev_stats_to_stats64(struct rtnl_link_stats64 * stats64,const struct net_device_stats * netdev_stats)10379 void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
10380 			     const struct net_device_stats *netdev_stats)
10381 {
10382 	size_t i, n = sizeof(*netdev_stats) / sizeof(atomic_long_t);
10383 	const atomic_long_t *src = (atomic_long_t *)netdev_stats;
10384 	u64 *dst = (u64 *)stats64;
10385 
10386 	BUILD_BUG_ON(n > sizeof(*stats64) / sizeof(u64));
10387 	for (i = 0; i < n; i++)
10388 		dst[i] = atomic_long_read(&src[i]);
10389 	/* zero out counters that only exist in rtnl_link_stats64 */
10390 	memset((char *)stats64 + n * sizeof(u64), 0,
10391 	       sizeof(*stats64) - n * sizeof(u64));
10392 }
10393 EXPORT_SYMBOL(netdev_stats_to_stats64);
10394 
netdev_core_stats_alloc(struct net_device * dev)10395 struct net_device_core_stats __percpu *netdev_core_stats_alloc(struct net_device *dev)
10396 {
10397 	struct net_device_core_stats __percpu *p;
10398 
10399 	p = alloc_percpu_gfp(struct net_device_core_stats,
10400 			     GFP_ATOMIC | __GFP_NOWARN);
10401 
10402 	if (p && cmpxchg(&dev->core_stats, NULL, p))
10403 		free_percpu(p);
10404 
10405 	/* This READ_ONCE() pairs with the cmpxchg() above */
10406 	return READ_ONCE(dev->core_stats);
10407 }
10408 EXPORT_SYMBOL(netdev_core_stats_alloc);
10409 
10410 /**
10411  *	dev_get_stats	- get network device statistics
10412  *	@dev: device to get statistics from
10413  *	@storage: place to store stats
10414  *
10415  *	Get network statistics from device. Return @storage.
10416  *	The device driver may provide its own method by setting
10417  *	dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
10418  *	otherwise the internal statistics structure is used.
10419  */
dev_get_stats(struct net_device * dev,struct rtnl_link_stats64 * storage)10420 struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
10421 					struct rtnl_link_stats64 *storage)
10422 {
10423 	const struct net_device_ops *ops = dev->netdev_ops;
10424 	const struct net_device_core_stats __percpu *p;
10425 
10426 	if (ops->ndo_get_stats64) {
10427 		memset(storage, 0, sizeof(*storage));
10428 		ops->ndo_get_stats64(dev, storage);
10429 	} else if (ops->ndo_get_stats) {
10430 		netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
10431 	} else {
10432 		netdev_stats_to_stats64(storage, &dev->stats);
10433 	}
10434 
10435 	/* This READ_ONCE() pairs with the write in netdev_core_stats_alloc() */
10436 	p = READ_ONCE(dev->core_stats);
10437 	if (p) {
10438 		const struct net_device_core_stats *core_stats;
10439 		int i;
10440 
10441 		for_each_possible_cpu(i) {
10442 			core_stats = per_cpu_ptr(p, i);
10443 			storage->rx_dropped += READ_ONCE(core_stats->rx_dropped);
10444 			storage->tx_dropped += READ_ONCE(core_stats->tx_dropped);
10445 			storage->rx_nohandler += READ_ONCE(core_stats->rx_nohandler);
10446 			storage->rx_otherhost_dropped += READ_ONCE(core_stats->rx_otherhost_dropped);
10447 		}
10448 	}
10449 	return storage;
10450 }
10451 EXPORT_SYMBOL(dev_get_stats);
10452 
10453 /**
10454  *	dev_fetch_sw_netstats - get per-cpu network device statistics
10455  *	@s: place to store stats
10456  *	@netstats: per-cpu network stats to read from
10457  *
10458  *	Read per-cpu network statistics and populate the related fields in @s.
10459  */
dev_fetch_sw_netstats(struct rtnl_link_stats64 * s,const struct pcpu_sw_netstats __percpu * netstats)10460 void dev_fetch_sw_netstats(struct rtnl_link_stats64 *s,
10461 			   const struct pcpu_sw_netstats __percpu *netstats)
10462 {
10463 	int cpu;
10464 
10465 	for_each_possible_cpu(cpu) {
10466 		u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
10467 		const struct pcpu_sw_netstats *stats;
10468 		unsigned int start;
10469 
10470 		stats = per_cpu_ptr(netstats, cpu);
10471 		do {
10472 			start = u64_stats_fetch_begin_irq(&stats->syncp);
10473 			rx_packets = u64_stats_read(&stats->rx_packets);
10474 			rx_bytes   = u64_stats_read(&stats->rx_bytes);
10475 			tx_packets = u64_stats_read(&stats->tx_packets);
10476 			tx_bytes   = u64_stats_read(&stats->tx_bytes);
10477 		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
10478 
10479 		s->rx_packets += rx_packets;
10480 		s->rx_bytes   += rx_bytes;
10481 		s->tx_packets += tx_packets;
10482 		s->tx_bytes   += tx_bytes;
10483 	}
10484 }
10485 EXPORT_SYMBOL_GPL(dev_fetch_sw_netstats);
10486 
10487 /**
10488  *	dev_get_tstats64 - ndo_get_stats64 implementation
10489  *	@dev: device to get statistics from
10490  *	@s: place to store stats
10491  *
10492  *	Populate @s from dev->stats and dev->tstats. Can be used as
10493  *	ndo_get_stats64() callback.
10494  */
dev_get_tstats64(struct net_device * dev,struct rtnl_link_stats64 * s)10495 void dev_get_tstats64(struct net_device *dev, struct rtnl_link_stats64 *s)
10496 {
10497 	netdev_stats_to_stats64(s, &dev->stats);
10498 	dev_fetch_sw_netstats(s, dev->tstats);
10499 }
10500 EXPORT_SYMBOL_GPL(dev_get_tstats64);
10501 
dev_ingress_queue_create(struct net_device * dev)10502 struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
10503 {
10504 	struct netdev_queue *queue = dev_ingress_queue(dev);
10505 
10506 #ifdef CONFIG_NET_CLS_ACT
10507 	if (queue)
10508 		return queue;
10509 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
10510 	if (!queue)
10511 		return NULL;
10512 	netdev_init_one_queue(dev, queue, NULL);
10513 	RCU_INIT_POINTER(queue->qdisc, &noop_qdisc);
10514 	queue->qdisc_sleeping = &noop_qdisc;
10515 	rcu_assign_pointer(dev->ingress_queue, queue);
10516 #endif
10517 	return queue;
10518 }
10519 
10520 static const struct ethtool_ops default_ethtool_ops;
10521 
netdev_set_default_ethtool_ops(struct net_device * dev,const struct ethtool_ops * ops)10522 void netdev_set_default_ethtool_ops(struct net_device *dev,
10523 				    const struct ethtool_ops *ops)
10524 {
10525 	if (dev->ethtool_ops == &default_ethtool_ops)
10526 		dev->ethtool_ops = ops;
10527 }
10528 EXPORT_SYMBOL_GPL(netdev_set_default_ethtool_ops);
10529 
netdev_freemem(struct net_device * dev)10530 void netdev_freemem(struct net_device *dev)
10531 {
10532 	char *addr = (char *)dev - dev->padded;
10533 
10534 	kvfree(addr);
10535 }
10536 
10537 /**
10538  * alloc_netdev_mqs - allocate network device
10539  * @sizeof_priv: size of private data to allocate space for
10540  * @name: device name format string
10541  * @name_assign_type: origin of device name
10542  * @setup: callback to initialize device
10543  * @txqs: the number of TX subqueues to allocate
10544  * @rxqs: the number of RX subqueues to allocate
10545  *
10546  * Allocates a struct net_device with private data area for driver use
10547  * and performs basic initialization.  Also allocates subqueue structs
10548  * for each queue on the device.
10549  */
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)10550 struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
10551 		unsigned char name_assign_type,
10552 		void (*setup)(struct net_device *),
10553 		unsigned int txqs, unsigned int rxqs)
10554 {
10555 	struct net_device *dev;
10556 	unsigned int alloc_size;
10557 	struct net_device *p;
10558 
10559 	BUG_ON(strlen(name) >= sizeof(dev->name));
10560 
10561 	if (txqs < 1) {
10562 		pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
10563 		return NULL;
10564 	}
10565 
10566 	if (rxqs < 1) {
10567 		pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
10568 		return NULL;
10569 	}
10570 
10571 	alloc_size = sizeof(struct net_device);
10572 	if (sizeof_priv) {
10573 		/* ensure 32-byte alignment of private area */
10574 		alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
10575 		alloc_size += sizeof_priv;
10576 	}
10577 	/* ensure 32-byte alignment of whole construct */
10578 	alloc_size += NETDEV_ALIGN - 1;
10579 
10580 	p = kvzalloc(alloc_size, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
10581 	if (!p)
10582 		return NULL;
10583 
10584 	dev = PTR_ALIGN(p, NETDEV_ALIGN);
10585 	dev->padded = (char *)dev - (char *)p;
10586 
10587 	ref_tracker_dir_init(&dev->refcnt_tracker, 128);
10588 #ifdef CONFIG_PCPU_DEV_REFCNT
10589 	dev->pcpu_refcnt = alloc_percpu(int);
10590 	if (!dev->pcpu_refcnt)
10591 		goto free_dev;
10592 	__dev_hold(dev);
10593 #else
10594 	refcount_set(&dev->dev_refcnt, 1);
10595 #endif
10596 
10597 	if (dev_addr_init(dev))
10598 		goto free_pcpu;
10599 
10600 	dev_mc_init(dev);
10601 	dev_uc_init(dev);
10602 
10603 	dev_net_set(dev, &init_net);
10604 
10605 	dev->gso_max_size = GSO_LEGACY_MAX_SIZE;
10606 	dev->gso_max_segs = GSO_MAX_SEGS;
10607 	dev->gro_max_size = GRO_LEGACY_MAX_SIZE;
10608 	dev->tso_max_size = TSO_LEGACY_MAX_SIZE;
10609 	dev->tso_max_segs = TSO_MAX_SEGS;
10610 	dev->upper_level = 1;
10611 	dev->lower_level = 1;
10612 #ifdef CONFIG_LOCKDEP
10613 	dev->nested_level = 0;
10614 	INIT_LIST_HEAD(&dev->unlink_list);
10615 #endif
10616 
10617 	INIT_LIST_HEAD(&dev->napi_list);
10618 	INIT_LIST_HEAD(&dev->unreg_list);
10619 	INIT_LIST_HEAD(&dev->close_list);
10620 	INIT_LIST_HEAD(&dev->link_watch_list);
10621 	INIT_LIST_HEAD(&dev->adj_list.upper);
10622 	INIT_LIST_HEAD(&dev->adj_list.lower);
10623 	INIT_LIST_HEAD(&dev->ptype_all);
10624 	INIT_LIST_HEAD(&dev->ptype_specific);
10625 	INIT_LIST_HEAD(&dev->net_notifier_list);
10626 #ifdef CONFIG_NET_SCHED
10627 	hash_init(dev->qdisc_hash);
10628 #endif
10629 	dev->priv_flags = IFF_XMIT_DST_RELEASE | IFF_XMIT_DST_RELEASE_PERM;
10630 	setup(dev);
10631 
10632 	if (!dev->tx_queue_len) {
10633 		dev->priv_flags |= IFF_NO_QUEUE;
10634 		dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
10635 	}
10636 
10637 	dev->num_tx_queues = txqs;
10638 	dev->real_num_tx_queues = txqs;
10639 	if (netif_alloc_netdev_queues(dev))
10640 		goto free_all;
10641 
10642 	dev->num_rx_queues = rxqs;
10643 	dev->real_num_rx_queues = rxqs;
10644 	if (netif_alloc_rx_queues(dev))
10645 		goto free_all;
10646 
10647 	strcpy(dev->name, name);
10648 	dev->name_assign_type = name_assign_type;
10649 	dev->group = INIT_NETDEV_GROUP;
10650 	if (!dev->ethtool_ops)
10651 		dev->ethtool_ops = &default_ethtool_ops;
10652 
10653 	nf_hook_netdev_init(dev);
10654 
10655 	return dev;
10656 
10657 free_all:
10658 	free_netdev(dev);
10659 	return NULL;
10660 
10661 free_pcpu:
10662 #ifdef CONFIG_PCPU_DEV_REFCNT
10663 	free_percpu(dev->pcpu_refcnt);
10664 free_dev:
10665 #endif
10666 	netdev_freemem(dev);
10667 	return NULL;
10668 }
10669 EXPORT_SYMBOL(alloc_netdev_mqs);
10670 
10671 /**
10672  * free_netdev - free network device
10673  * @dev: device
10674  *
10675  * This function does the last stage of destroying an allocated device
10676  * interface. The reference to the device object is released. If this
10677  * is the last reference then it will be freed.Must be called in process
10678  * context.
10679  */
free_netdev(struct net_device * dev)10680 void free_netdev(struct net_device *dev)
10681 {
10682 	struct napi_struct *p, *n;
10683 
10684 	might_sleep();
10685 
10686 	/* When called immediately after register_netdevice() failed the unwind
10687 	 * handling may still be dismantling the device. Handle that case by
10688 	 * deferring the free.
10689 	 */
10690 	if (dev->reg_state == NETREG_UNREGISTERING) {
10691 		ASSERT_RTNL();
10692 		dev->needs_free_netdev = true;
10693 		return;
10694 	}
10695 
10696 	netif_free_tx_queues(dev);
10697 	netif_free_rx_queues(dev);
10698 
10699 	kfree(rcu_dereference_protected(dev->ingress_queue, 1));
10700 
10701 	/* Flush device addresses */
10702 	dev_addr_flush(dev);
10703 
10704 	list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
10705 		netif_napi_del(p);
10706 
10707 	ref_tracker_dir_exit(&dev->refcnt_tracker);
10708 #ifdef CONFIG_PCPU_DEV_REFCNT
10709 	free_percpu(dev->pcpu_refcnt);
10710 	dev->pcpu_refcnt = NULL;
10711 #endif
10712 	free_percpu(dev->core_stats);
10713 	dev->core_stats = NULL;
10714 	free_percpu(dev->xdp_bulkq);
10715 	dev->xdp_bulkq = NULL;
10716 
10717 	/*  Compatibility with error handling in drivers */
10718 	if (dev->reg_state == NETREG_UNINITIALIZED) {
10719 		netdev_freemem(dev);
10720 		return;
10721 	}
10722 
10723 	BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
10724 	dev->reg_state = NETREG_RELEASED;
10725 
10726 	/* will free via device release */
10727 	put_device(&dev->dev);
10728 }
10729 EXPORT_SYMBOL(free_netdev);
10730 
10731 /**
10732  *	synchronize_net -  Synchronize with packet receive processing
10733  *
10734  *	Wait for packets currently being received to be done.
10735  *	Does not block later packets from starting.
10736  */
synchronize_net(void)10737 void synchronize_net(void)
10738 {
10739 	might_sleep();
10740 	if (rtnl_is_locked())
10741 		synchronize_rcu_expedited();
10742 	else
10743 		synchronize_rcu();
10744 }
10745 EXPORT_SYMBOL(synchronize_net);
10746 
10747 /**
10748  *	unregister_netdevice_queue - remove device from the kernel
10749  *	@dev: device
10750  *	@head: list
10751  *
10752  *	This function shuts down a device interface and removes it
10753  *	from the kernel tables.
10754  *	If head not NULL, device is queued to be unregistered later.
10755  *
10756  *	Callers must hold the rtnl semaphore.  You may want
10757  *	unregister_netdev() instead of this.
10758  */
10759 
unregister_netdevice_queue(struct net_device * dev,struct list_head * head)10760 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
10761 {
10762 	ASSERT_RTNL();
10763 
10764 	if (head) {
10765 		list_move_tail(&dev->unreg_list, head);
10766 	} else {
10767 		LIST_HEAD(single);
10768 
10769 		list_add(&dev->unreg_list, &single);
10770 		unregister_netdevice_many(&single);
10771 	}
10772 }
10773 EXPORT_SYMBOL(unregister_netdevice_queue);
10774 
10775 /**
10776  *	unregister_netdevice_many - unregister many devices
10777  *	@head: list of devices
10778  *
10779  *  Note: As most callers use a stack allocated list_head,
10780  *  we force a list_del() to make sure stack wont be corrupted later.
10781  */
unregister_netdevice_many(struct list_head * head)10782 void unregister_netdevice_many(struct list_head *head)
10783 {
10784 	struct net_device *dev, *tmp;
10785 	LIST_HEAD(close_head);
10786 
10787 	BUG_ON(dev_boot_phase);
10788 	ASSERT_RTNL();
10789 
10790 	if (list_empty(head))
10791 		return;
10792 
10793 	list_for_each_entry_safe(dev, tmp, head, unreg_list) {
10794 		/* Some devices call without registering
10795 		 * for initialization unwind. Remove those
10796 		 * devices and proceed with the remaining.
10797 		 */
10798 		if (dev->reg_state == NETREG_UNINITIALIZED) {
10799 			pr_debug("unregister_netdevice: device %s/%p never was registered\n",
10800 				 dev->name, dev);
10801 
10802 			WARN_ON(1);
10803 			list_del(&dev->unreg_list);
10804 			continue;
10805 		}
10806 		dev->dismantle = true;
10807 		BUG_ON(dev->reg_state != NETREG_REGISTERED);
10808 	}
10809 
10810 	/* If device is running, close it first. */
10811 	list_for_each_entry(dev, head, unreg_list)
10812 		list_add_tail(&dev->close_list, &close_head);
10813 	dev_close_many(&close_head, true);
10814 
10815 	list_for_each_entry(dev, head, unreg_list) {
10816 		/* And unlink it from device chain. */
10817 		write_lock(&dev_base_lock);
10818 		unlist_netdevice(dev, false);
10819 		dev->reg_state = NETREG_UNREGISTERING;
10820 		write_unlock(&dev_base_lock);
10821 	}
10822 	flush_all_backlogs();
10823 
10824 	synchronize_net();
10825 
10826 	list_for_each_entry(dev, head, unreg_list) {
10827 		struct sk_buff *skb = NULL;
10828 
10829 		/* Shutdown queueing discipline. */
10830 		dev_shutdown(dev);
10831 
10832 		dev_xdp_uninstall(dev);
10833 
10834 		netdev_offload_xstats_disable_all(dev);
10835 
10836 		/* Notify protocols, that we are about to destroy
10837 		 * this device. They should clean all the things.
10838 		 */
10839 		call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10840 
10841 		if (!dev->rtnl_link_ops ||
10842 		    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
10843 			skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, 0,
10844 						     GFP_KERNEL, NULL, 0);
10845 
10846 		/*
10847 		 *	Flush the unicast and multicast chains
10848 		 */
10849 		dev_uc_flush(dev);
10850 		dev_mc_flush(dev);
10851 
10852 		netdev_name_node_alt_flush(dev);
10853 		netdev_name_node_free(dev->name_node);
10854 
10855 		if (dev->netdev_ops->ndo_uninit)
10856 			dev->netdev_ops->ndo_uninit(dev);
10857 
10858 		if (skb)
10859 			rtmsg_ifinfo_send(skb, dev, GFP_KERNEL);
10860 
10861 		/* Notifier chain MUST detach us all upper devices. */
10862 		WARN_ON(netdev_has_any_upper_dev(dev));
10863 		WARN_ON(netdev_has_any_lower_dev(dev));
10864 
10865 		/* Remove entries from kobject tree */
10866 		netdev_unregister_kobject(dev);
10867 #ifdef CONFIG_XPS
10868 		/* Remove XPS queueing entries */
10869 		netif_reset_xps_queues_gt(dev, 0);
10870 #endif
10871 	}
10872 
10873 	synchronize_net();
10874 
10875 	list_for_each_entry(dev, head, unreg_list) {
10876 		netdev_put(dev, &dev->dev_registered_tracker);
10877 		net_set_todo(dev);
10878 	}
10879 
10880 	list_del(head);
10881 }
10882 EXPORT_SYMBOL(unregister_netdevice_many);
10883 
10884 /**
10885  *	unregister_netdev - remove device from the kernel
10886  *	@dev: device
10887  *
10888  *	This function shuts down a device interface and removes it
10889  *	from the kernel tables.
10890  *
10891  *	This is just a wrapper for unregister_netdevice that takes
10892  *	the rtnl semaphore.  In general you want to use this and not
10893  *	unregister_netdevice.
10894  */
unregister_netdev(struct net_device * dev)10895 void unregister_netdev(struct net_device *dev)
10896 {
10897 	rtnl_lock();
10898 	unregister_netdevice(dev);
10899 	rtnl_unlock();
10900 }
10901 EXPORT_SYMBOL(unregister_netdev);
10902 
10903 /**
10904  *	__dev_change_net_namespace - move device to different nethost namespace
10905  *	@dev: device
10906  *	@net: network namespace
10907  *	@pat: If not NULL name pattern to try if the current device name
10908  *	      is already taken in the destination network namespace.
10909  *	@new_ifindex: If not zero, specifies device index in the target
10910  *	              namespace.
10911  *
10912  *	This function shuts down a device interface and moves it
10913  *	to a new network namespace. On success 0 is returned, on
10914  *	a failure a netagive errno code is returned.
10915  *
10916  *	Callers must hold the rtnl semaphore.
10917  */
10918 
__dev_change_net_namespace(struct net_device * dev,struct net * net,const char * pat,int new_ifindex)10919 int __dev_change_net_namespace(struct net_device *dev, struct net *net,
10920 			       const char *pat, int new_ifindex)
10921 {
10922 	struct net *net_old = dev_net(dev);
10923 	int err, new_nsid;
10924 
10925 	ASSERT_RTNL();
10926 
10927 	/* Don't allow namespace local devices to be moved. */
10928 	err = -EINVAL;
10929 	if (dev->features & NETIF_F_NETNS_LOCAL)
10930 		goto out;
10931 
10932 	/* Ensure the device has been registrered */
10933 	if (dev->reg_state != NETREG_REGISTERED)
10934 		goto out;
10935 
10936 	/* Get out if there is nothing todo */
10937 	err = 0;
10938 	if (net_eq(net_old, net))
10939 		goto out;
10940 
10941 	/* Pick the destination device name, and ensure
10942 	 * we can use it in the destination network namespace.
10943 	 */
10944 	err = -EEXIST;
10945 	if (netdev_name_in_use(net, dev->name)) {
10946 		/* We get here if we can't use the current device name */
10947 		if (!pat)
10948 			goto out;
10949 		err = dev_get_valid_name(net, dev, pat);
10950 		if (err < 0)
10951 			goto out;
10952 	}
10953 
10954 	/* Check that new_ifindex isn't used yet. */
10955 	err = -EBUSY;
10956 	if (new_ifindex && __dev_get_by_index(net, new_ifindex))
10957 		goto out;
10958 
10959 	/*
10960 	 * And now a mini version of register_netdevice unregister_netdevice.
10961 	 */
10962 
10963 	/* If device is running close it first. */
10964 	dev_close(dev);
10965 
10966 	/* And unlink it from device chain */
10967 	unlist_netdevice(dev, true);
10968 
10969 	synchronize_net();
10970 
10971 	/* Shutdown queueing discipline. */
10972 	dev_shutdown(dev);
10973 
10974 	/* Notify protocols, that we are about to destroy
10975 	 * this device. They should clean all the things.
10976 	 *
10977 	 * Note that dev->reg_state stays at NETREG_REGISTERED.
10978 	 * This is wanted because this way 8021q and macvlan know
10979 	 * the device is just moving and can keep their slaves up.
10980 	 */
10981 	call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10982 	rcu_barrier();
10983 
10984 	new_nsid = peernet2id_alloc(dev_net(dev), net, GFP_KERNEL);
10985 	/* If there is an ifindex conflict assign a new one */
10986 	if (!new_ifindex) {
10987 		if (__dev_get_by_index(net, dev->ifindex))
10988 			new_ifindex = dev_new_index(net);
10989 		else
10990 			new_ifindex = dev->ifindex;
10991 	}
10992 
10993 	rtmsg_ifinfo_newnet(RTM_DELLINK, dev, ~0U, GFP_KERNEL, &new_nsid,
10994 			    new_ifindex);
10995 
10996 	/*
10997 	 *	Flush the unicast and multicast chains
10998 	 */
10999 	dev_uc_flush(dev);
11000 	dev_mc_flush(dev);
11001 
11002 	/* Send a netdev-removed uevent to the old namespace */
11003 	kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);
11004 	netdev_adjacent_del_links(dev);
11005 
11006 	/* Move per-net netdevice notifiers that are following the netdevice */
11007 	move_netdevice_notifiers_dev_net(dev, net);
11008 
11009 	/* Actually switch the network namespace */
11010 	dev_net_set(dev, net);
11011 	dev->ifindex = new_ifindex;
11012 
11013 	/* Send a netdev-add uevent to the new namespace */
11014 	kobject_uevent(&dev->dev.kobj, KOBJ_ADD);
11015 	netdev_adjacent_add_links(dev);
11016 
11017 	/* Fixup kobjects */
11018 	err = device_rename(&dev->dev, dev->name);
11019 	WARN_ON(err);
11020 
11021 	/* Adapt owner in case owning user namespace of target network
11022 	 * namespace is different from the original one.
11023 	 */
11024 	err = netdev_change_owner(dev, net_old, net);
11025 	WARN_ON(err);
11026 
11027 	/* Add the device back in the hashes */
11028 	list_netdevice(dev);
11029 
11030 	/* Notify protocols, that a new device appeared. */
11031 	call_netdevice_notifiers(NETDEV_REGISTER, dev);
11032 
11033 	/*
11034 	 *	Prevent userspace races by waiting until the network
11035 	 *	device is fully setup before sending notifications.
11036 	 */
11037 	rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
11038 
11039 	synchronize_net();
11040 	err = 0;
11041 out:
11042 	return err;
11043 }
11044 EXPORT_SYMBOL_GPL(__dev_change_net_namespace);
11045 
dev_cpu_dead(unsigned int oldcpu)11046 static int dev_cpu_dead(unsigned int oldcpu)
11047 {
11048 	struct sk_buff **list_skb;
11049 	struct sk_buff *skb;
11050 	unsigned int cpu;
11051 	struct softnet_data *sd, *oldsd, *remsd = NULL;
11052 
11053 	local_irq_disable();
11054 	cpu = smp_processor_id();
11055 	sd = &per_cpu(softnet_data, cpu);
11056 	oldsd = &per_cpu(softnet_data, oldcpu);
11057 
11058 	/* Find end of our completion_queue. */
11059 	list_skb = &sd->completion_queue;
11060 	while (*list_skb)
11061 		list_skb = &(*list_skb)->next;
11062 	/* Append completion queue from offline CPU. */
11063 	*list_skb = oldsd->completion_queue;
11064 	oldsd->completion_queue = NULL;
11065 
11066 	/* Append output queue from offline CPU. */
11067 	if (oldsd->output_queue) {
11068 		*sd->output_queue_tailp = oldsd->output_queue;
11069 		sd->output_queue_tailp = oldsd->output_queue_tailp;
11070 		oldsd->output_queue = NULL;
11071 		oldsd->output_queue_tailp = &oldsd->output_queue;
11072 	}
11073 	/* Append NAPI poll list from offline CPU, with one exception :
11074 	 * process_backlog() must be called by cpu owning percpu backlog.
11075 	 * We properly handle process_queue & input_pkt_queue later.
11076 	 */
11077 	while (!list_empty(&oldsd->poll_list)) {
11078 		struct napi_struct *napi = list_first_entry(&oldsd->poll_list,
11079 							    struct napi_struct,
11080 							    poll_list);
11081 
11082 		list_del_init(&napi->poll_list);
11083 		if (napi->poll == process_backlog)
11084 			napi->state = 0;
11085 		else
11086 			____napi_schedule(sd, napi);
11087 	}
11088 
11089 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
11090 	local_irq_enable();
11091 
11092 #ifdef CONFIG_RPS
11093 	remsd = oldsd->rps_ipi_list;
11094 	oldsd->rps_ipi_list = NULL;
11095 #endif
11096 	/* send out pending IPI's on offline CPU */
11097 	net_rps_send_ipi(remsd);
11098 
11099 	/* Process offline CPU's input_pkt_queue */
11100 	while ((skb = __skb_dequeue(&oldsd->process_queue))) {
11101 		netif_rx(skb);
11102 		input_queue_head_incr(oldsd);
11103 	}
11104 	while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) {
11105 		netif_rx(skb);
11106 		input_queue_head_incr(oldsd);
11107 	}
11108 
11109 	return 0;
11110 }
11111 
11112 /**
11113  *	netdev_increment_features - increment feature set by one
11114  *	@all: current feature set
11115  *	@one: new feature set
11116  *	@mask: mask feature set
11117  *
11118  *	Computes a new feature set after adding a device with feature set
11119  *	@one to the master device with current feature set @all.  Will not
11120  *	enable anything that is off in @mask. Returns the new feature set.
11121  */
netdev_increment_features(netdev_features_t all,netdev_features_t one,netdev_features_t mask)11122 netdev_features_t netdev_increment_features(netdev_features_t all,
11123 	netdev_features_t one, netdev_features_t mask)
11124 {
11125 	if (mask & NETIF_F_HW_CSUM)
11126 		mask |= NETIF_F_CSUM_MASK;
11127 	mask |= NETIF_F_VLAN_CHALLENGED;
11128 
11129 	all |= one & (NETIF_F_ONE_FOR_ALL | NETIF_F_CSUM_MASK) & mask;
11130 	all &= one | ~NETIF_F_ALL_FOR_ALL;
11131 
11132 	/* If one device supports hw checksumming, set for all. */
11133 	if (all & NETIF_F_HW_CSUM)
11134 		all &= ~(NETIF_F_CSUM_MASK & ~NETIF_F_HW_CSUM);
11135 
11136 	return all;
11137 }
11138 EXPORT_SYMBOL(netdev_increment_features);
11139 
netdev_create_hash(void)11140 static struct hlist_head * __net_init netdev_create_hash(void)
11141 {
11142 	int i;
11143 	struct hlist_head *hash;
11144 
11145 	hash = kmalloc_array(NETDEV_HASHENTRIES, sizeof(*hash), GFP_KERNEL);
11146 	if (hash != NULL)
11147 		for (i = 0; i < NETDEV_HASHENTRIES; i++)
11148 			INIT_HLIST_HEAD(&hash[i]);
11149 
11150 	return hash;
11151 }
11152 
11153 /* Initialize per network namespace state */
netdev_init(struct net * net)11154 static int __net_init netdev_init(struct net *net)
11155 {
11156 	BUILD_BUG_ON(GRO_HASH_BUCKETS >
11157 		     8 * sizeof_field(struct napi_struct, gro_bitmask));
11158 
11159 	INIT_LIST_HEAD(&net->dev_base_head);
11160 
11161 	net->dev_name_head = netdev_create_hash();
11162 	if (net->dev_name_head == NULL)
11163 		goto err_name;
11164 
11165 	net->dev_index_head = netdev_create_hash();
11166 	if (net->dev_index_head == NULL)
11167 		goto err_idx;
11168 
11169 	RAW_INIT_NOTIFIER_HEAD(&net->netdev_chain);
11170 
11171 	return 0;
11172 
11173 err_idx:
11174 	kfree(net->dev_name_head);
11175 err_name:
11176 	return -ENOMEM;
11177 }
11178 
11179 /**
11180  *	netdev_drivername - network driver for the device
11181  *	@dev: network device
11182  *
11183  *	Determine network driver for device.
11184  */
netdev_drivername(const struct net_device * dev)11185 const char *netdev_drivername(const struct net_device *dev)
11186 {
11187 	const struct device_driver *driver;
11188 	const struct device *parent;
11189 	const char *empty = "";
11190 
11191 	parent = dev->dev.parent;
11192 	if (!parent)
11193 		return empty;
11194 
11195 	driver = parent->driver;
11196 	if (driver && driver->name)
11197 		return driver->name;
11198 	return empty;
11199 }
11200 
__netdev_printk(const char * level,const struct net_device * dev,struct va_format * vaf)11201 static void __netdev_printk(const char *level, const struct net_device *dev,
11202 			    struct va_format *vaf)
11203 {
11204 	if (dev && dev->dev.parent) {
11205 		dev_printk_emit(level[1] - '0',
11206 				dev->dev.parent,
11207 				"%s %s %s%s: %pV",
11208 				dev_driver_string(dev->dev.parent),
11209 				dev_name(dev->dev.parent),
11210 				netdev_name(dev), netdev_reg_state(dev),
11211 				vaf);
11212 	} else if (dev) {
11213 		printk("%s%s%s: %pV",
11214 		       level, netdev_name(dev), netdev_reg_state(dev), vaf);
11215 	} else {
11216 		printk("%s(NULL net_device): %pV", level, vaf);
11217 	}
11218 }
11219 
netdev_printk(const char * level,const struct net_device * dev,const char * format,...)11220 void netdev_printk(const char *level, const struct net_device *dev,
11221 		   const char *format, ...)
11222 {
11223 	struct va_format vaf;
11224 	va_list args;
11225 
11226 	va_start(args, format);
11227 
11228 	vaf.fmt = format;
11229 	vaf.va = &args;
11230 
11231 	__netdev_printk(level, dev, &vaf);
11232 
11233 	va_end(args);
11234 }
11235 EXPORT_SYMBOL(netdev_printk);
11236 
11237 #define define_netdev_printk_level(func, level)			\
11238 void func(const struct net_device *dev, const char *fmt, ...)	\
11239 {								\
11240 	struct va_format vaf;					\
11241 	va_list args;						\
11242 								\
11243 	va_start(args, fmt);					\
11244 								\
11245 	vaf.fmt = fmt;						\
11246 	vaf.va = &args;						\
11247 								\
11248 	__netdev_printk(level, dev, &vaf);			\
11249 								\
11250 	va_end(args);						\
11251 }								\
11252 EXPORT_SYMBOL(func);
11253 
11254 define_netdev_printk_level(netdev_emerg, KERN_EMERG);
11255 define_netdev_printk_level(netdev_alert, KERN_ALERT);
11256 define_netdev_printk_level(netdev_crit, KERN_CRIT);
11257 define_netdev_printk_level(netdev_err, KERN_ERR);
11258 define_netdev_printk_level(netdev_warn, KERN_WARNING);
11259 define_netdev_printk_level(netdev_notice, KERN_NOTICE);
11260 define_netdev_printk_level(netdev_info, KERN_INFO);
11261 
netdev_exit(struct net * net)11262 static void __net_exit netdev_exit(struct net *net)
11263 {
11264 	kfree(net->dev_name_head);
11265 	kfree(net->dev_index_head);
11266 	if (net != &init_net)
11267 		WARN_ON_ONCE(!list_empty(&net->dev_base_head));
11268 }
11269 
11270 static struct pernet_operations __net_initdata netdev_net_ops = {
11271 	.init = netdev_init,
11272 	.exit = netdev_exit,
11273 };
11274 
default_device_exit_net(struct net * net)11275 static void __net_exit default_device_exit_net(struct net *net)
11276 {
11277 	struct net_device *dev, *aux;
11278 	/*
11279 	 * Push all migratable network devices back to the
11280 	 * initial network namespace
11281 	 */
11282 	ASSERT_RTNL();
11283 	for_each_netdev_safe(net, dev, aux) {
11284 		int err;
11285 		char fb_name[IFNAMSIZ];
11286 
11287 		/* Ignore unmoveable devices (i.e. loopback) */
11288 		if (dev->features & NETIF_F_NETNS_LOCAL)
11289 			continue;
11290 
11291 		/* Leave virtual devices for the generic cleanup */
11292 		if (dev->rtnl_link_ops && !dev->rtnl_link_ops->netns_refund)
11293 			continue;
11294 
11295 		/* Push remaining network devices to init_net */
11296 		snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
11297 		if (netdev_name_in_use(&init_net, fb_name))
11298 			snprintf(fb_name, IFNAMSIZ, "dev%%d");
11299 		err = dev_change_net_namespace(dev, &init_net, fb_name);
11300 		if (err) {
11301 			pr_emerg("%s: failed to move %s to init_net: %d\n",
11302 				 __func__, dev->name, err);
11303 			BUG();
11304 		}
11305 	}
11306 }
11307 
default_device_exit_batch(struct list_head * net_list)11308 static void __net_exit default_device_exit_batch(struct list_head *net_list)
11309 {
11310 	/* At exit all network devices most be removed from a network
11311 	 * namespace.  Do this in the reverse order of registration.
11312 	 * Do this across as many network namespaces as possible to
11313 	 * improve batching efficiency.
11314 	 */
11315 	struct net_device *dev;
11316 	struct net *net;
11317 	LIST_HEAD(dev_kill_list);
11318 
11319 	rtnl_lock();
11320 	list_for_each_entry(net, net_list, exit_list) {
11321 		default_device_exit_net(net);
11322 		cond_resched();
11323 	}
11324 
11325 	list_for_each_entry(net, net_list, exit_list) {
11326 		for_each_netdev_reverse(net, dev) {
11327 			if (dev->rtnl_link_ops && dev->rtnl_link_ops->dellink)
11328 				dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
11329 			else
11330 				unregister_netdevice_queue(dev, &dev_kill_list);
11331 		}
11332 	}
11333 	unregister_netdevice_many(&dev_kill_list);
11334 	rtnl_unlock();
11335 }
11336 
11337 static struct pernet_operations __net_initdata default_device_ops = {
11338 	.exit_batch = default_device_exit_batch,
11339 };
11340 
11341 /*
11342  *	Initialize the DEV module. At boot time this walks the device list and
11343  *	unhooks any devices that fail to initialise (normally hardware not
11344  *	present) and leaves us with a valid list of present and active devices.
11345  *
11346  */
11347 
11348 /*
11349  *       This is called single threaded during boot, so no need
11350  *       to take the rtnl semaphore.
11351  */
net_dev_init(void)11352 static int __init net_dev_init(void)
11353 {
11354 	int i, rc = -ENOMEM;
11355 
11356 	BUG_ON(!dev_boot_phase);
11357 
11358 	if (dev_proc_init())
11359 		goto out;
11360 
11361 	if (netdev_kobject_init())
11362 		goto out;
11363 
11364 	INIT_LIST_HEAD(&ptype_all);
11365 	for (i = 0; i < PTYPE_HASH_SIZE; i++)
11366 		INIT_LIST_HEAD(&ptype_base[i]);
11367 
11368 	if (register_pernet_subsys(&netdev_net_ops))
11369 		goto out;
11370 
11371 	/*
11372 	 *	Initialise the packet receive queues.
11373 	 */
11374 
11375 	for_each_possible_cpu(i) {
11376 		struct work_struct *flush = per_cpu_ptr(&flush_works, i);
11377 		struct softnet_data *sd = &per_cpu(softnet_data, i);
11378 
11379 		INIT_WORK(flush, flush_backlog);
11380 
11381 		skb_queue_head_init(&sd->input_pkt_queue);
11382 		skb_queue_head_init(&sd->process_queue);
11383 #ifdef CONFIG_XFRM_OFFLOAD
11384 		skb_queue_head_init(&sd->xfrm_backlog);
11385 #endif
11386 		INIT_LIST_HEAD(&sd->poll_list);
11387 		sd->output_queue_tailp = &sd->output_queue;
11388 #ifdef CONFIG_RPS
11389 		INIT_CSD(&sd->csd, rps_trigger_softirq, sd);
11390 		sd->cpu = i;
11391 #endif
11392 		INIT_CSD(&sd->defer_csd, trigger_rx_softirq, sd);
11393 		spin_lock_init(&sd->defer_lock);
11394 
11395 		init_gro_hash(&sd->backlog);
11396 		sd->backlog.poll = process_backlog;
11397 		sd->backlog.weight = weight_p;
11398 	}
11399 
11400 	dev_boot_phase = 0;
11401 
11402 	/* The loopback device is special if any other network devices
11403 	 * is present in a network namespace the loopback device must
11404 	 * be present. Since we now dynamically allocate and free the
11405 	 * loopback device ensure this invariant is maintained by
11406 	 * keeping the loopback device as the first device on the
11407 	 * list of network devices.  Ensuring the loopback devices
11408 	 * is the first device that appears and the last network device
11409 	 * that disappears.
11410 	 */
11411 	if (register_pernet_device(&loopback_net_ops))
11412 		goto out;
11413 
11414 	if (register_pernet_device(&default_device_ops))
11415 		goto out;
11416 
11417 	open_softirq(NET_TX_SOFTIRQ, net_tx_action);
11418 	open_softirq(NET_RX_SOFTIRQ, net_rx_action);
11419 
11420 	rc = cpuhp_setup_state_nocalls(CPUHP_NET_DEV_DEAD, "net/dev:dead",
11421 				       NULL, dev_cpu_dead);
11422 	WARN_ON(rc < 0);
11423 	rc = 0;
11424 out:
11425 	return rc;
11426 }
11427 
11428 subsys_initcall(net_dev_init);
11429