1 /*
2  * 	NET3	Protocol independent device support routines.
3  *
4  *		This program is free software; you can redistribute it and/or
5  *		modify it under the terms of the GNU General Public License
6  *		as published by the Free Software Foundation; either version
7  *		2 of the License, or (at your option) any later version.
8  *
9  *	Derived from the non IP parts of dev.c 1.0.19
10  * 		Authors:	Ross Biro
11  *				Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12  *				Mark Evans, <evansmp@uhura.aston.ac.uk>
13  *
14  *	Additional Authors:
15  *		Florian la Roche <rzsfl@rz.uni-sb.de>
16  *		Alan Cox <gw4pts@gw4pts.ampr.org>
17  *		David Hinds <dahinds@users.sourceforge.net>
18  *		Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
19  *		Adam Sulmicki <adam@cfar.umd.edu>
20  *              Pekka Riikonen <priikone@poesidon.pspt.fi>
21  *
22  *	Changes:
23  *              D.J. Barrow     :       Fixed bug where dev->refcnt gets set
24  *              			to 2 if register_netdev gets called
25  *              			before net_dev_init & also removed a
26  *              			few lines of code in the process.
27  *		Alan Cox	:	device private ioctl copies fields back.
28  *		Alan Cox	:	Transmit queue code does relevant
29  *					stunts to keep the queue safe.
30  *		Alan Cox	:	Fixed double lock.
31  *		Alan Cox	:	Fixed promisc NULL pointer trap
32  *		????????	:	Support the full private ioctl range
33  *		Alan Cox	:	Moved ioctl permission check into
34  *					drivers
35  *		Tim Kordas	:	SIOCADDMULTI/SIOCDELMULTI
36  *		Alan Cox	:	100 backlog just doesn't cut it when
37  *					you start doing multicast video 8)
38  *		Alan Cox	:	Rewrote net_bh and list manager.
39  *		Alan Cox	: 	Fix ETH_P_ALL echoback lengths.
40  *		Alan Cox	:	Took out transmit every packet pass
41  *					Saved a few bytes in the ioctl handler
42  *		Alan Cox	:	Network driver sets packet type before
43  *					calling netif_rx. Saves a function
44  *					call a packet.
45  *		Alan Cox	:	Hashed net_bh()
46  *		Richard Kooijman:	Timestamp fixes.
47  *		Alan Cox	:	Wrong field in SIOCGIFDSTADDR
48  *		Alan Cox	:	Device lock protection.
49  *		Alan Cox	: 	Fixed nasty side effect of device close
50  *					changes.
51  *		Rudi Cilibrasi	:	Pass the right thing to
52  *					set_mac_address()
53  *		Dave Miller	:	32bit quantity for the device lock to
54  *					make it work out on a Sparc.
55  *		Bjorn Ekwall	:	Added KERNELD hack.
56  *		Alan Cox	:	Cleaned up the backlog initialise.
57  *		Craig Metz	:	SIOCGIFCONF fix if space for under
58  *					1 device.
59  *	    Thomas Bogendoerfer :	Return ENODEV for dev_open, if there
60  *					is no device open function.
61  *		Andi Kleen	:	Fix error reporting for SIOCGIFCONF
62  *	    Michael Chastain	:	Fix signed/unsigned for SIOCGIFCONF
63  *		Cyrus Durgin	:	Cleaned for KMOD
64  *		Adam Sulmicki   :	Bug Fix : Network Device Unload
65  *					A network device unload needs to purge
66  *					the backlog queue.
67  *	Paul Rusty Russell	:	SIOCSIFNAME
68  *              Pekka Riikonen  :	Netdev boot-time settings code
69  *              Andrew Morton   :       Make unregister_netdevice wait
70  *              			indefinitely on dev->refcnt
71  * 		J Hadi Salim	:	- Backlog queue sampling
72  *				        - netif_rx() feedback
73  */
74 
75 #include <asm/uaccess.h>
76 #include <asm/system.h>
77 #include <linux/bitops.h>
78 #include <linux/capability.h>
79 #include <linux/cpu.h>
80 #include <linux/types.h>
81 #include <linux/kernel.h>
82 #include <linux/hash.h>
83 #include <linux/slab.h>
84 #include <linux/sched.h>
85 #include <linux/mutex.h>
86 #include <linux/string.h>
87 #include <linux/mm.h>
88 #include <linux/socket.h>
89 #include <linux/sockios.h>
90 #include <linux/errno.h>
91 #include <linux/interrupt.h>
92 #include <linux/if_ether.h>
93 #include <linux/netdevice.h>
94 #include <linux/etherdevice.h>
95 #include <linux/ethtool.h>
96 #include <linux/notifier.h>
97 #include <linux/skbuff.h>
98 #include <net/net_namespace.h>
99 #include <net/sock.h>
100 #include <linux/rtnetlink.h>
101 #include <linux/proc_fs.h>
102 #include <linux/seq_file.h>
103 #include <linux/stat.h>
104 #include <net/dst.h>
105 #include <net/pkt_sched.h>
106 #include <net/checksum.h>
107 #include <net/xfrm.h>
108 #include <linux/highmem.h>
109 #include <linux/init.h>
110 #include <linux/kmod.h>
111 #include <linux/module.h>
112 #include <linux/netpoll.h>
113 #include <linux/rcupdate.h>
114 #include <linux/delay.h>
115 #include <net/wext.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 <linux/ipv6.h>
127 #include <linux/in.h>
128 #include <linux/jhash.h>
129 #include <linux/random.h>
130 #include <trace/events/napi.h>
131 #include <trace/events/net.h>
132 #include <trace/events/skb.h>
133 #include <linux/pci.h>
134 #include <linux/inetdevice.h>
135 #include <linux/cpu_rmap.h>
136 
137 #include "net-sysfs.h"
138 
139 /* Instead of increasing this, you should create a hash table. */
140 #define MAX_GRO_SKBS 8
141 
142 /* This should be increased if a protocol with a bigger head is added. */
143 #define GRO_MAX_HEAD (MAX_HEADER + 128)
144 
145 /*
146  *	The list of packet types we will receive (as opposed to discard)
147  *	and the routines to invoke.
148  *
149  *	Why 16. Because with 16 the only overlap we get on a hash of the
150  *	low nibble of the protocol value is RARP/SNAP/X.25.
151  *
152  *      NOTE:  That is no longer true with the addition of VLAN tags.  Not
153  *             sure which should go first, but I bet it won't make much
154  *             difference if we are running VLANs.  The good news is that
155  *             this protocol won't be in the list unless compiled in, so
156  *             the average user (w/out VLANs) will not be adversely affected.
157  *             --BLG
158  *
159  *		0800	IP
160  *		8100    802.1Q VLAN
161  *		0001	802.3
162  *		0002	AX.25
163  *		0004	802.2
164  *		8035	RARP
165  *		0005	SNAP
166  *		0805	X.25
167  *		0806	ARP
168  *		8137	IPX
169  *		0009	Localtalk
170  *		86DD	IPv6
171  */
172 
173 #define PTYPE_HASH_SIZE	(16)
174 #define PTYPE_HASH_MASK	(PTYPE_HASH_SIZE - 1)
175 
176 static DEFINE_SPINLOCK(ptype_lock);
177 static struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
178 static struct list_head ptype_all __read_mostly;	/* Taps */
179 
180 /*
181  * The @dev_base_head list is protected by @dev_base_lock and the rtnl
182  * semaphore.
183  *
184  * Pure readers hold dev_base_lock for reading, or rcu_read_lock()
185  *
186  * Writers must hold the rtnl semaphore while they loop through the
187  * dev_base_head list, and hold dev_base_lock for writing when they do the
188  * actual updates.  This allows pure readers to access the list even
189  * while a writer is preparing to update it.
190  *
191  * To put it another way, dev_base_lock is held for writing only to
192  * protect against pure readers; the rtnl semaphore provides the
193  * protection against other writers.
194  *
195  * See, for example usages, register_netdevice() and
196  * unregister_netdevice(), which must be called with the rtnl
197  * semaphore held.
198  */
199 DEFINE_RWLOCK(dev_base_lock);
200 EXPORT_SYMBOL(dev_base_lock);
201 
dev_name_hash(struct net * net,const char * name)202 static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
203 {
204 	unsigned hash = full_name_hash(name, strnlen(name, IFNAMSIZ));
205 	return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
206 }
207 
dev_index_hash(struct net * net,int ifindex)208 static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
209 {
210 	return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
211 }
212 
rps_lock(struct softnet_data * sd)213 static inline void rps_lock(struct softnet_data *sd)
214 {
215 #ifdef CONFIG_RPS
216 	spin_lock(&sd->input_pkt_queue.lock);
217 #endif
218 }
219 
rps_unlock(struct softnet_data * sd)220 static inline void rps_unlock(struct softnet_data *sd)
221 {
222 #ifdef CONFIG_RPS
223 	spin_unlock(&sd->input_pkt_queue.lock);
224 #endif
225 }
226 
227 /* Device list insertion */
list_netdevice(struct net_device * dev)228 static int list_netdevice(struct net_device *dev)
229 {
230 	struct net *net = dev_net(dev);
231 
232 	ASSERT_RTNL();
233 
234 	write_lock_bh(&dev_base_lock);
235 	list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
236 	hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
237 	hlist_add_head_rcu(&dev->index_hlist,
238 			   dev_index_hash(net, dev->ifindex));
239 	write_unlock_bh(&dev_base_lock);
240 	return 0;
241 }
242 
243 /* Device list removal
244  * caller must respect a RCU grace period before freeing/reusing dev
245  */
unlist_netdevice(struct net_device * dev)246 static void unlist_netdevice(struct net_device *dev)
247 {
248 	ASSERT_RTNL();
249 
250 	/* Unlink dev from the device chain */
251 	write_lock_bh(&dev_base_lock);
252 	list_del_rcu(&dev->dev_list);
253 	hlist_del_rcu(&dev->name_hlist);
254 	hlist_del_rcu(&dev->index_hlist);
255 	write_unlock_bh(&dev_base_lock);
256 }
257 
258 /*
259  *	Our notifier list
260  */
261 
262 static RAW_NOTIFIER_HEAD(netdev_chain);
263 
264 /*
265  *	Device drivers call our routines to queue packets here. We empty the
266  *	queue in the local softnet handler.
267  */
268 
269 DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
270 EXPORT_PER_CPU_SYMBOL(softnet_data);
271 
272 #ifdef CONFIG_LOCKDEP
273 /*
274  * register_netdevice() inits txq->_xmit_lock and sets lockdep class
275  * according to dev->type
276  */
277 static const unsigned short netdev_lock_type[] =
278 	{ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
279 	 ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
280 	 ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
281 	 ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
282 	 ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
283 	 ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
284 	 ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
285 	 ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
286 	 ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
287 	 ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
288 	 ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
289 	 ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
290 	 ARPHRD_FCFABRIC, ARPHRD_IEEE802_TR, ARPHRD_IEEE80211,
291 	 ARPHRD_IEEE80211_PRISM, ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET,
292 	 ARPHRD_PHONET_PIPE, ARPHRD_IEEE802154,
293 	 ARPHRD_VOID, ARPHRD_NONE};
294 
295 static const char *const netdev_lock_name[] =
296 	{"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
297 	 "_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
298 	 "_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
299 	 "_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
300 	 "_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
301 	 "_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
302 	 "_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
303 	 "_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
304 	 "_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
305 	 "_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
306 	 "_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
307 	 "_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
308 	 "_xmit_FCFABRIC", "_xmit_IEEE802_TR", "_xmit_IEEE80211",
309 	 "_xmit_IEEE80211_PRISM", "_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET",
310 	 "_xmit_PHONET_PIPE", "_xmit_IEEE802154",
311 	 "_xmit_VOID", "_xmit_NONE"};
312 
313 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
314 static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
315 
netdev_lock_pos(unsigned short dev_type)316 static inline unsigned short netdev_lock_pos(unsigned short dev_type)
317 {
318 	int i;
319 
320 	for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
321 		if (netdev_lock_type[i] == dev_type)
322 			return i;
323 	/* the last key is used by default */
324 	return ARRAY_SIZE(netdev_lock_type) - 1;
325 }
326 
netdev_set_xmit_lockdep_class(spinlock_t * lock,unsigned short dev_type)327 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
328 						 unsigned short dev_type)
329 {
330 	int i;
331 
332 	i = netdev_lock_pos(dev_type);
333 	lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
334 				   netdev_lock_name[i]);
335 }
336 
netdev_set_addr_lockdep_class(struct net_device * dev)337 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
338 {
339 	int i;
340 
341 	i = netdev_lock_pos(dev->type);
342 	lockdep_set_class_and_name(&dev->addr_list_lock,
343 				   &netdev_addr_lock_key[i],
344 				   netdev_lock_name[i]);
345 }
346 #else
netdev_set_xmit_lockdep_class(spinlock_t * lock,unsigned short dev_type)347 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
348 						 unsigned short dev_type)
349 {
350 }
netdev_set_addr_lockdep_class(struct net_device * dev)351 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
352 {
353 }
354 #endif
355 
356 /*******************************************************************************
357 
358 		Protocol management and registration routines
359 
360 *******************************************************************************/
361 
362 /*
363  *	Add a protocol ID to the list. Now that the input handler is
364  *	smarter we can dispense with all the messy stuff that used to be
365  *	here.
366  *
367  *	BEWARE!!! Protocol handlers, mangling input packets,
368  *	MUST BE last in hash buckets and checking protocol handlers
369  *	MUST start from promiscuous ptype_all chain in net_bh.
370  *	It is true now, do not change it.
371  *	Explanation follows: if protocol handler, mangling packet, will
372  *	be the first on list, it is not able to sense, that packet
373  *	is cloned and should be copied-on-write, so that it will
374  *	change it and subsequent readers will get broken packet.
375  *							--ANK (980803)
376  */
377 
ptype_head(const struct packet_type * pt)378 static inline struct list_head *ptype_head(const struct packet_type *pt)
379 {
380 	if (pt->type == htons(ETH_P_ALL))
381 		return &ptype_all;
382 	else
383 		return &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
384 }
385 
386 /**
387  *	dev_add_pack - add packet handler
388  *	@pt: packet type declaration
389  *
390  *	Add a protocol handler to the networking stack. The passed &packet_type
391  *	is linked into kernel lists and may not be freed until it has been
392  *	removed from the kernel lists.
393  *
394  *	This call does not sleep therefore it can not
395  *	guarantee all CPU's that are in middle of receiving packets
396  *	will see the new packet type (until the next received packet).
397  */
398 
dev_add_pack(struct packet_type * pt)399 void dev_add_pack(struct packet_type *pt)
400 {
401 	struct list_head *head = ptype_head(pt);
402 
403 	spin_lock(&ptype_lock);
404 	list_add_rcu(&pt->list, head);
405 	spin_unlock(&ptype_lock);
406 }
407 EXPORT_SYMBOL(dev_add_pack);
408 
409 /**
410  *	__dev_remove_pack	 - remove packet handler
411  *	@pt: packet type declaration
412  *
413  *	Remove a protocol handler that was previously added to the kernel
414  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
415  *	from the kernel lists and can be freed or reused once this function
416  *	returns.
417  *
418  *      The packet type might still be in use by receivers
419  *	and must not be freed until after all the CPU's have gone
420  *	through a quiescent state.
421  */
__dev_remove_pack(struct packet_type * pt)422 void __dev_remove_pack(struct packet_type *pt)
423 {
424 	struct list_head *head = ptype_head(pt);
425 	struct packet_type *pt1;
426 
427 	spin_lock(&ptype_lock);
428 
429 	list_for_each_entry(pt1, head, list) {
430 		if (pt == pt1) {
431 			list_del_rcu(&pt->list);
432 			goto out;
433 		}
434 	}
435 
436 	printk(KERN_WARNING "dev_remove_pack: %p not found.\n", pt);
437 out:
438 	spin_unlock(&ptype_lock);
439 }
440 EXPORT_SYMBOL(__dev_remove_pack);
441 
442 /**
443  *	dev_remove_pack	 - remove packet handler
444  *	@pt: packet type declaration
445  *
446  *	Remove a protocol handler that was previously added to the kernel
447  *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
448  *	from the kernel lists and can be freed or reused once this function
449  *	returns.
450  *
451  *	This call sleeps to guarantee that no CPU is looking at the packet
452  *	type after return.
453  */
dev_remove_pack(struct packet_type * pt)454 void dev_remove_pack(struct packet_type *pt)
455 {
456 	__dev_remove_pack(pt);
457 
458 	synchronize_net();
459 }
460 EXPORT_SYMBOL(dev_remove_pack);
461 
462 /******************************************************************************
463 
464 		      Device Boot-time Settings Routines
465 
466 *******************************************************************************/
467 
468 /* Boot time configuration table */
469 static struct netdev_boot_setup dev_boot_setup[NETDEV_BOOT_SETUP_MAX];
470 
471 /**
472  *	netdev_boot_setup_add	- add new setup entry
473  *	@name: name of the device
474  *	@map: configured settings for the device
475  *
476  *	Adds new setup entry to the dev_boot_setup list.  The function
477  *	returns 0 on error and 1 on success.  This is a generic routine to
478  *	all netdevices.
479  */
netdev_boot_setup_add(char * name,struct ifmap * map)480 static int netdev_boot_setup_add(char *name, struct ifmap *map)
481 {
482 	struct netdev_boot_setup *s;
483 	int i;
484 
485 	s = dev_boot_setup;
486 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
487 		if (s[i].name[0] == '\0' || s[i].name[0] == ' ') {
488 			memset(s[i].name, 0, sizeof(s[i].name));
489 			strlcpy(s[i].name, name, IFNAMSIZ);
490 			memcpy(&s[i].map, map, sizeof(s[i].map));
491 			break;
492 		}
493 	}
494 
495 	return i >= NETDEV_BOOT_SETUP_MAX ? 0 : 1;
496 }
497 
498 /**
499  *	netdev_boot_setup_check	- check boot time settings
500  *	@dev: the netdevice
501  *
502  * 	Check boot time settings for the device.
503  *	The found settings are set for the device to be used
504  *	later in the device probing.
505  *	Returns 0 if no settings found, 1 if they are.
506  */
netdev_boot_setup_check(struct net_device * dev)507 int netdev_boot_setup_check(struct net_device *dev)
508 {
509 	struct netdev_boot_setup *s = dev_boot_setup;
510 	int i;
511 
512 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
513 		if (s[i].name[0] != '\0' && s[i].name[0] != ' ' &&
514 		    !strcmp(dev->name, s[i].name)) {
515 			dev->irq 	= s[i].map.irq;
516 			dev->base_addr 	= s[i].map.base_addr;
517 			dev->mem_start 	= s[i].map.mem_start;
518 			dev->mem_end 	= s[i].map.mem_end;
519 			return 1;
520 		}
521 	}
522 	return 0;
523 }
524 EXPORT_SYMBOL(netdev_boot_setup_check);
525 
526 
527 /**
528  *	netdev_boot_base	- get address from boot time settings
529  *	@prefix: prefix for network device
530  *	@unit: id for network device
531  *
532  * 	Check boot time settings for the base address of device.
533  *	The found settings are set for the device to be used
534  *	later in the device probing.
535  *	Returns 0 if no settings found.
536  */
netdev_boot_base(const char * prefix,int unit)537 unsigned long netdev_boot_base(const char *prefix, int unit)
538 {
539 	const struct netdev_boot_setup *s = dev_boot_setup;
540 	char name[IFNAMSIZ];
541 	int i;
542 
543 	sprintf(name, "%s%d", prefix, unit);
544 
545 	/*
546 	 * If device already registered then return base of 1
547 	 * to indicate not to probe for this interface
548 	 */
549 	if (__dev_get_by_name(&init_net, name))
550 		return 1;
551 
552 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++)
553 		if (!strcmp(name, s[i].name))
554 			return s[i].map.base_addr;
555 	return 0;
556 }
557 
558 /*
559  * Saves at boot time configured settings for any netdevice.
560  */
netdev_boot_setup(char * str)561 int __init netdev_boot_setup(char *str)
562 {
563 	int ints[5];
564 	struct ifmap map;
565 
566 	str = get_options(str, ARRAY_SIZE(ints), ints);
567 	if (!str || !*str)
568 		return 0;
569 
570 	/* Save settings */
571 	memset(&map, 0, sizeof(map));
572 	if (ints[0] > 0)
573 		map.irq = ints[1];
574 	if (ints[0] > 1)
575 		map.base_addr = ints[2];
576 	if (ints[0] > 2)
577 		map.mem_start = ints[3];
578 	if (ints[0] > 3)
579 		map.mem_end = ints[4];
580 
581 	/* Add new entry to the list */
582 	return netdev_boot_setup_add(str, &map);
583 }
584 
585 __setup("netdev=", netdev_boot_setup);
586 
587 /*******************************************************************************
588 
589 			    Device Interface Subroutines
590 
591 *******************************************************************************/
592 
593 /**
594  *	__dev_get_by_name	- find a device by its name
595  *	@net: the applicable net namespace
596  *	@name: name to find
597  *
598  *	Find an interface by name. Must be called under RTNL semaphore
599  *	or @dev_base_lock. If the name is found a pointer to the device
600  *	is returned. If the name is not found then %NULL is returned. The
601  *	reference counters are not incremented so the caller must be
602  *	careful with locks.
603  */
604 
__dev_get_by_name(struct net * net,const char * name)605 struct net_device *__dev_get_by_name(struct net *net, const char *name)
606 {
607 	struct hlist_node *p;
608 	struct net_device *dev;
609 	struct hlist_head *head = dev_name_hash(net, name);
610 
611 	hlist_for_each_entry(dev, p, head, name_hlist)
612 		if (!strncmp(dev->name, name, IFNAMSIZ))
613 			return dev;
614 
615 	return NULL;
616 }
617 EXPORT_SYMBOL(__dev_get_by_name);
618 
619 /**
620  *	dev_get_by_name_rcu	- find a device by its name
621  *	@net: the applicable net namespace
622  *	@name: name to find
623  *
624  *	Find an interface by name.
625  *	If the name is found a pointer to the device is returned.
626  * 	If the name is not found then %NULL is returned.
627  *	The reference counters are not incremented so the caller must be
628  *	careful with locks. The caller must hold RCU lock.
629  */
630 
dev_get_by_name_rcu(struct net * net,const char * name)631 struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
632 {
633 	struct hlist_node *p;
634 	struct net_device *dev;
635 	struct hlist_head *head = dev_name_hash(net, name);
636 
637 	hlist_for_each_entry_rcu(dev, p, head, name_hlist)
638 		if (!strncmp(dev->name, name, IFNAMSIZ))
639 			return dev;
640 
641 	return NULL;
642 }
643 EXPORT_SYMBOL(dev_get_by_name_rcu);
644 
645 /**
646  *	dev_get_by_name		- find a device by its name
647  *	@net: the applicable net namespace
648  *	@name: name to find
649  *
650  *	Find an interface by name. This can be called from any
651  *	context and does its own locking. The returned handle has
652  *	the usage count incremented and the caller must use dev_put() to
653  *	release it when it is no longer needed. %NULL is returned if no
654  *	matching device is found.
655  */
656 
dev_get_by_name(struct net * net,const char * name)657 struct net_device *dev_get_by_name(struct net *net, const char *name)
658 {
659 	struct net_device *dev;
660 
661 	rcu_read_lock();
662 	dev = dev_get_by_name_rcu(net, name);
663 	if (dev)
664 		dev_hold(dev);
665 	rcu_read_unlock();
666 	return dev;
667 }
668 EXPORT_SYMBOL(dev_get_by_name);
669 
670 /**
671  *	__dev_get_by_index - find a device by its ifindex
672  *	@net: the applicable net namespace
673  *	@ifindex: index of device
674  *
675  *	Search for an interface by index. Returns %NULL if the device
676  *	is not found or a pointer to the device. The device has not
677  *	had its reference counter increased so the caller must be careful
678  *	about locking. The caller must hold either the RTNL semaphore
679  *	or @dev_base_lock.
680  */
681 
__dev_get_by_index(struct net * net,int ifindex)682 struct net_device *__dev_get_by_index(struct net *net, int ifindex)
683 {
684 	struct hlist_node *p;
685 	struct net_device *dev;
686 	struct hlist_head *head = dev_index_hash(net, ifindex);
687 
688 	hlist_for_each_entry(dev, p, head, index_hlist)
689 		if (dev->ifindex == ifindex)
690 			return dev;
691 
692 	return NULL;
693 }
694 EXPORT_SYMBOL(__dev_get_by_index);
695 
696 /**
697  *	dev_get_by_index_rcu - find a device by its ifindex
698  *	@net: the applicable net namespace
699  *	@ifindex: index of device
700  *
701  *	Search for an interface by index. Returns %NULL if the device
702  *	is not found or a pointer to the device. The device has not
703  *	had its reference counter increased so the caller must be careful
704  *	about locking. The caller must hold RCU lock.
705  */
706 
dev_get_by_index_rcu(struct net * net,int ifindex)707 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
708 {
709 	struct hlist_node *p;
710 	struct net_device *dev;
711 	struct hlist_head *head = dev_index_hash(net, ifindex);
712 
713 	hlist_for_each_entry_rcu(dev, p, head, index_hlist)
714 		if (dev->ifindex == ifindex)
715 			return dev;
716 
717 	return NULL;
718 }
719 EXPORT_SYMBOL(dev_get_by_index_rcu);
720 
721 
722 /**
723  *	dev_get_by_index - find a device by its ifindex
724  *	@net: the applicable net namespace
725  *	@ifindex: index of device
726  *
727  *	Search for an interface by index. Returns NULL if the device
728  *	is not found or a pointer to the device. The device returned has
729  *	had a reference added and the pointer is safe until the user calls
730  *	dev_put to indicate they have finished with it.
731  */
732 
dev_get_by_index(struct net * net,int ifindex)733 struct net_device *dev_get_by_index(struct net *net, int ifindex)
734 {
735 	struct net_device *dev;
736 
737 	rcu_read_lock();
738 	dev = dev_get_by_index_rcu(net, ifindex);
739 	if (dev)
740 		dev_hold(dev);
741 	rcu_read_unlock();
742 	return dev;
743 }
744 EXPORT_SYMBOL(dev_get_by_index);
745 
746 /**
747  *	dev_getbyhwaddr_rcu - find a device by its hardware address
748  *	@net: the applicable net namespace
749  *	@type: media type of device
750  *	@ha: hardware address
751  *
752  *	Search for an interface by MAC address. Returns NULL if the device
753  *	is not found or a pointer to the device.
754  *	The caller must hold RCU or RTNL.
755  *	The returned device has not had its ref count increased
756  *	and the caller must therefore be careful about locking
757  *
758  */
759 
dev_getbyhwaddr_rcu(struct net * net,unsigned short type,const char * ha)760 struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
761 				       const char *ha)
762 {
763 	struct net_device *dev;
764 
765 	for_each_netdev_rcu(net, dev)
766 		if (dev->type == type &&
767 		    !memcmp(dev->dev_addr, ha, dev->addr_len))
768 			return dev;
769 
770 	return NULL;
771 }
772 EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
773 
__dev_getfirstbyhwtype(struct net * net,unsigned short type)774 struct net_device *__dev_getfirstbyhwtype(struct net *net, unsigned short type)
775 {
776 	struct net_device *dev;
777 
778 	ASSERT_RTNL();
779 	for_each_netdev(net, dev)
780 		if (dev->type == type)
781 			return dev;
782 
783 	return NULL;
784 }
785 EXPORT_SYMBOL(__dev_getfirstbyhwtype);
786 
dev_getfirstbyhwtype(struct net * net,unsigned short type)787 struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
788 {
789 	struct net_device *dev, *ret = NULL;
790 
791 	rcu_read_lock();
792 	for_each_netdev_rcu(net, dev)
793 		if (dev->type == type) {
794 			dev_hold(dev);
795 			ret = dev;
796 			break;
797 		}
798 	rcu_read_unlock();
799 	return ret;
800 }
801 EXPORT_SYMBOL(dev_getfirstbyhwtype);
802 
803 /**
804  *	dev_get_by_flags_rcu - find any device with given flags
805  *	@net: the applicable net namespace
806  *	@if_flags: IFF_* values
807  *	@mask: bitmask of bits in if_flags to check
808  *
809  *	Search for any interface with the given flags. Returns NULL if a device
810  *	is not found or a pointer to the device. Must be called inside
811  *	rcu_read_lock(), and result refcount is unchanged.
812  */
813 
dev_get_by_flags_rcu(struct net * net,unsigned short if_flags,unsigned short mask)814 struct net_device *dev_get_by_flags_rcu(struct net *net, unsigned short if_flags,
815 				    unsigned short mask)
816 {
817 	struct net_device *dev, *ret;
818 
819 	ret = NULL;
820 	for_each_netdev_rcu(net, dev) {
821 		if (((dev->flags ^ if_flags) & mask) == 0) {
822 			ret = dev;
823 			break;
824 		}
825 	}
826 	return ret;
827 }
828 EXPORT_SYMBOL(dev_get_by_flags_rcu);
829 
830 /**
831  *	dev_valid_name - check if name is okay for network device
832  *	@name: name string
833  *
834  *	Network device names need to be valid file names to
835  *	to allow sysfs to work.  We also disallow any kind of
836  *	whitespace.
837  */
dev_valid_name(const char * name)838 int dev_valid_name(const char *name)
839 {
840 	if (*name == '\0')
841 		return 0;
842 	if (strlen(name) >= IFNAMSIZ)
843 		return 0;
844 	if (!strcmp(name, ".") || !strcmp(name, ".."))
845 		return 0;
846 
847 	while (*name) {
848 		if (*name == '/' || isspace(*name))
849 			return 0;
850 		name++;
851 	}
852 	return 1;
853 }
854 EXPORT_SYMBOL(dev_valid_name);
855 
856 /**
857  *	__dev_alloc_name - allocate a name for a device
858  *	@net: network namespace to allocate the device name in
859  *	@name: name format string
860  *	@buf:  scratch buffer and result name string
861  *
862  *	Passed a format string - eg "lt%d" it will try and find a suitable
863  *	id. It scans list of devices to build up a free map, then chooses
864  *	the first empty slot. The caller must hold the dev_base or rtnl lock
865  *	while allocating the name and adding the device in order to avoid
866  *	duplicates.
867  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
868  *	Returns the number of the unit assigned or a negative errno code.
869  */
870 
__dev_alloc_name(struct net * net,const char * name,char * buf)871 static int __dev_alloc_name(struct net *net, const char *name, char *buf)
872 {
873 	int i = 0;
874 	const char *p;
875 	const int max_netdevices = 8*PAGE_SIZE;
876 	unsigned long *inuse;
877 	struct net_device *d;
878 
879 	p = strnchr(name, IFNAMSIZ-1, '%');
880 	if (p) {
881 		/*
882 		 * Verify the string as this thing may have come from
883 		 * the user.  There must be either one "%d" and no other "%"
884 		 * characters.
885 		 */
886 		if (p[1] != 'd' || strchr(p + 2, '%'))
887 			return -EINVAL;
888 
889 		/* Use one page as a bit array of possible slots */
890 		inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
891 		if (!inuse)
892 			return -ENOMEM;
893 
894 		for_each_netdev(net, d) {
895 			if (!sscanf(d->name, name, &i))
896 				continue;
897 			if (i < 0 || i >= max_netdevices)
898 				continue;
899 
900 			/*  avoid cases where sscanf is not exact inverse of printf */
901 			snprintf(buf, IFNAMSIZ, name, i);
902 			if (!strncmp(buf, d->name, IFNAMSIZ))
903 				set_bit(i, inuse);
904 		}
905 
906 		i = find_first_zero_bit(inuse, max_netdevices);
907 		free_page((unsigned long) inuse);
908 	}
909 
910 	if (buf != name)
911 		snprintf(buf, IFNAMSIZ, name, i);
912 	if (!__dev_get_by_name(net, buf))
913 		return i;
914 
915 	/* It is possible to run out of possible slots
916 	 * when the name is long and there isn't enough space left
917 	 * for the digits, or if all bits are used.
918 	 */
919 	return -ENFILE;
920 }
921 
922 /**
923  *	dev_alloc_name - allocate a name for a device
924  *	@dev: device
925  *	@name: name format string
926  *
927  *	Passed a format string - eg "lt%d" it will try and find a suitable
928  *	id. It scans list of devices to build up a free map, then chooses
929  *	the first empty slot. The caller must hold the dev_base or rtnl lock
930  *	while allocating the name and adding the device in order to avoid
931  *	duplicates.
932  *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
933  *	Returns the number of the unit assigned or a negative errno code.
934  */
935 
dev_alloc_name(struct net_device * dev,const char * name)936 int dev_alloc_name(struct net_device *dev, const char *name)
937 {
938 	char buf[IFNAMSIZ];
939 	struct net *net;
940 	int ret;
941 
942 	BUG_ON(!dev_net(dev));
943 	net = dev_net(dev);
944 	ret = __dev_alloc_name(net, name, buf);
945 	if (ret >= 0)
946 		strlcpy(dev->name, buf, IFNAMSIZ);
947 	return ret;
948 }
949 EXPORT_SYMBOL(dev_alloc_name);
950 
dev_get_valid_name(struct net_device * dev,const char * name,bool fmt)951 static int dev_get_valid_name(struct net_device *dev, const char *name, bool fmt)
952 {
953 	struct net *net;
954 
955 	BUG_ON(!dev_net(dev));
956 	net = dev_net(dev);
957 
958 	if (!dev_valid_name(name))
959 		return -EINVAL;
960 
961 	if (fmt && strchr(name, '%'))
962 		return dev_alloc_name(dev, name);
963 	else if (__dev_get_by_name(net, name))
964 		return -EEXIST;
965 	else if (dev->name != name)
966 		strlcpy(dev->name, name, IFNAMSIZ);
967 
968 	return 0;
969 }
970 
971 /**
972  *	dev_change_name - change name of a device
973  *	@dev: device
974  *	@newname: name (or format string) must be at least IFNAMSIZ
975  *
976  *	Change name of a device, can pass format strings "eth%d".
977  *	for wildcarding.
978  */
dev_change_name(struct net_device * dev,const char * newname)979 int dev_change_name(struct net_device *dev, const char *newname)
980 {
981 	char oldname[IFNAMSIZ];
982 	int err = 0;
983 	int ret;
984 	struct net *net;
985 
986 	ASSERT_RTNL();
987 	BUG_ON(!dev_net(dev));
988 
989 	net = dev_net(dev);
990 	if (dev->flags & IFF_UP)
991 		return -EBUSY;
992 
993 	if (strncmp(newname, dev->name, IFNAMSIZ) == 0)
994 		return 0;
995 
996 	memcpy(oldname, dev->name, IFNAMSIZ);
997 
998 	err = dev_get_valid_name(dev, newname, 1);
999 	if (err < 0)
1000 		return err;
1001 
1002 rollback:
1003 	ret = device_rename(&dev->dev, dev->name);
1004 	if (ret) {
1005 		memcpy(dev->name, oldname, IFNAMSIZ);
1006 		return ret;
1007 	}
1008 
1009 	write_lock_bh(&dev_base_lock);
1010 	hlist_del(&dev->name_hlist);
1011 	write_unlock_bh(&dev_base_lock);
1012 
1013 	synchronize_rcu();
1014 
1015 	write_lock_bh(&dev_base_lock);
1016 	hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
1017 	write_unlock_bh(&dev_base_lock);
1018 
1019 	ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1020 	ret = notifier_to_errno(ret);
1021 
1022 	if (ret) {
1023 		/* err >= 0 after dev_alloc_name() or stores the first errno */
1024 		if (err >= 0) {
1025 			err = ret;
1026 			memcpy(dev->name, oldname, IFNAMSIZ);
1027 			goto rollback;
1028 		} else {
1029 			printk(KERN_ERR
1030 			       "%s: name change rollback failed: %d.\n",
1031 			       dev->name, ret);
1032 		}
1033 	}
1034 
1035 	return err;
1036 }
1037 
1038 /**
1039  *	dev_set_alias - change ifalias of a device
1040  *	@dev: device
1041  *	@alias: name up to IFALIASZ
1042  *	@len: limit of bytes to copy from info
1043  *
1044  *	Set ifalias for a device,
1045  */
dev_set_alias(struct net_device * dev,const char * alias,size_t len)1046 int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
1047 {
1048 	ASSERT_RTNL();
1049 
1050 	if (len >= IFALIASZ)
1051 		return -EINVAL;
1052 
1053 	if (!len) {
1054 		if (dev->ifalias) {
1055 			kfree(dev->ifalias);
1056 			dev->ifalias = NULL;
1057 		}
1058 		return 0;
1059 	}
1060 
1061 	dev->ifalias = krealloc(dev->ifalias, len + 1, GFP_KERNEL);
1062 	if (!dev->ifalias)
1063 		return -ENOMEM;
1064 
1065 	strlcpy(dev->ifalias, alias, len+1);
1066 	return len;
1067 }
1068 
1069 
1070 /**
1071  *	netdev_features_change - device changes features
1072  *	@dev: device to cause notification
1073  *
1074  *	Called to indicate a device has changed features.
1075  */
netdev_features_change(struct net_device * dev)1076 void netdev_features_change(struct net_device *dev)
1077 {
1078 	call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1079 }
1080 EXPORT_SYMBOL(netdev_features_change);
1081 
1082 /**
1083  *	netdev_state_change - device changes state
1084  *	@dev: device to cause notification
1085  *
1086  *	Called to indicate a device has changed state. This function calls
1087  *	the notifier chains for netdev_chain and sends a NEWLINK message
1088  *	to the routing socket.
1089  */
netdev_state_change(struct net_device * dev)1090 void netdev_state_change(struct net_device *dev)
1091 {
1092 	if (dev->flags & IFF_UP) {
1093 		call_netdevice_notifiers(NETDEV_CHANGE, dev);
1094 		rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
1095 	}
1096 }
1097 EXPORT_SYMBOL(netdev_state_change);
1098 
netdev_bonding_change(struct net_device * dev,unsigned long event)1099 int netdev_bonding_change(struct net_device *dev, unsigned long event)
1100 {
1101 	return call_netdevice_notifiers(event, dev);
1102 }
1103 EXPORT_SYMBOL(netdev_bonding_change);
1104 
1105 /**
1106  *	dev_load 	- load a network module
1107  *	@net: the applicable net namespace
1108  *	@name: name of interface
1109  *
1110  *	If a network interface is not present and the process has suitable
1111  *	privileges this function loads the module. If module loading is not
1112  *	available in this kernel then it becomes a nop.
1113  */
1114 
dev_load(struct net * net,const char * name)1115 void dev_load(struct net *net, const char *name)
1116 {
1117 	struct net_device *dev;
1118 	int no_module;
1119 
1120 	rcu_read_lock();
1121 	dev = dev_get_by_name_rcu(net, name);
1122 	rcu_read_unlock();
1123 
1124 	no_module = !dev;
1125 	if (no_module && capable(CAP_NET_ADMIN))
1126 		no_module = request_module("netdev-%s", name);
1127 	if (no_module && capable(CAP_SYS_MODULE)) {
1128 		if (!request_module("%s", name))
1129 			pr_err("Loading kernel module for a network device "
1130 "with CAP_SYS_MODULE (deprecated).  Use CAP_NET_ADMIN and alias netdev-%s "
1131 "instead\n", name);
1132 	}
1133 }
1134 EXPORT_SYMBOL(dev_load);
1135 
__dev_open(struct net_device * dev)1136 static int __dev_open(struct net_device *dev)
1137 {
1138 	const struct net_device_ops *ops = dev->netdev_ops;
1139 	int ret;
1140 
1141 	ASSERT_RTNL();
1142 
1143 	if (!netif_device_present(dev))
1144 		return -ENODEV;
1145 
1146 	ret = call_netdevice_notifiers(NETDEV_PRE_UP, dev);
1147 	ret = notifier_to_errno(ret);
1148 	if (ret)
1149 		return ret;
1150 
1151 	set_bit(__LINK_STATE_START, &dev->state);
1152 
1153 	if (ops->ndo_validate_addr)
1154 		ret = ops->ndo_validate_addr(dev);
1155 
1156 	if (!ret && ops->ndo_open)
1157 		ret = ops->ndo_open(dev);
1158 
1159 	if (ret)
1160 		clear_bit(__LINK_STATE_START, &dev->state);
1161 	else {
1162 		dev->flags |= IFF_UP;
1163 		net_dmaengine_get();
1164 		dev_set_rx_mode(dev);
1165 		dev_activate(dev);
1166 	}
1167 
1168 	return ret;
1169 }
1170 
1171 /**
1172  *	dev_open	- prepare an interface for use.
1173  *	@dev:	device to open
1174  *
1175  *	Takes a device from down to up state. The device's private open
1176  *	function is invoked and then the multicast lists are loaded. Finally
1177  *	the device is moved into the up state and a %NETDEV_UP message is
1178  *	sent to the netdev notifier chain.
1179  *
1180  *	Calling this function on an active interface is a nop. On a failure
1181  *	a negative errno code is returned.
1182  */
dev_open(struct net_device * dev)1183 int dev_open(struct net_device *dev)
1184 {
1185 	int ret;
1186 
1187 	if (dev->flags & IFF_UP)
1188 		return 0;
1189 
1190 	ret = __dev_open(dev);
1191 	if (ret < 0)
1192 		return ret;
1193 
1194 	rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
1195 	call_netdevice_notifiers(NETDEV_UP, dev);
1196 
1197 	return ret;
1198 }
1199 EXPORT_SYMBOL(dev_open);
1200 
__dev_close_many(struct list_head * head)1201 static int __dev_close_many(struct list_head *head)
1202 {
1203 	struct net_device *dev;
1204 
1205 	ASSERT_RTNL();
1206 	might_sleep();
1207 
1208 	list_for_each_entry(dev, head, unreg_list) {
1209 		call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
1210 
1211 		clear_bit(__LINK_STATE_START, &dev->state);
1212 
1213 		/* Synchronize to scheduled poll. We cannot touch poll list, it
1214 		 * can be even on different cpu. So just clear netif_running().
1215 		 *
1216 		 * dev->stop() will invoke napi_disable() on all of it's
1217 		 * napi_struct instances on this device.
1218 		 */
1219 		smp_mb__after_clear_bit(); /* Commit netif_running(). */
1220 	}
1221 
1222 	dev_deactivate_many(head);
1223 
1224 	list_for_each_entry(dev, head, unreg_list) {
1225 		const struct net_device_ops *ops = dev->netdev_ops;
1226 
1227 		/*
1228 		 *	Call the device specific close. This cannot fail.
1229 		 *	Only if device is UP
1230 		 *
1231 		 *	We allow it to be called even after a DETACH hot-plug
1232 		 *	event.
1233 		 */
1234 		if (ops->ndo_stop)
1235 			ops->ndo_stop(dev);
1236 
1237 		dev->flags &= ~IFF_UP;
1238 		net_dmaengine_put();
1239 	}
1240 
1241 	return 0;
1242 }
1243 
__dev_close(struct net_device * dev)1244 static int __dev_close(struct net_device *dev)
1245 {
1246 	int retval;
1247 	LIST_HEAD(single);
1248 
1249 	list_add(&dev->unreg_list, &single);
1250 	retval = __dev_close_many(&single);
1251 	list_del(&single);
1252 	return retval;
1253 }
1254 
dev_close_many(struct list_head * head)1255 static int dev_close_many(struct list_head *head)
1256 {
1257 	struct net_device *dev, *tmp;
1258 	LIST_HEAD(tmp_list);
1259 
1260 	list_for_each_entry_safe(dev, tmp, head, unreg_list)
1261 		if (!(dev->flags & IFF_UP))
1262 			list_move(&dev->unreg_list, &tmp_list);
1263 
1264 	__dev_close_many(head);
1265 
1266 	list_for_each_entry(dev, head, unreg_list) {
1267 		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
1268 		call_netdevice_notifiers(NETDEV_DOWN, dev);
1269 	}
1270 
1271 	/* rollback_registered_many needs the complete original list */
1272 	list_splice(&tmp_list, head);
1273 	return 0;
1274 }
1275 
1276 /**
1277  *	dev_close - shutdown an interface.
1278  *	@dev: device to shutdown
1279  *
1280  *	This function moves an active device into down state. A
1281  *	%NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
1282  *	is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
1283  *	chain.
1284  */
dev_close(struct net_device * dev)1285 int dev_close(struct net_device *dev)
1286 {
1287 	if (dev->flags & IFF_UP) {
1288 		LIST_HEAD(single);
1289 
1290 		list_add(&dev->unreg_list, &single);
1291 		dev_close_many(&single);
1292 		list_del(&single);
1293 	}
1294 	return 0;
1295 }
1296 EXPORT_SYMBOL(dev_close);
1297 
1298 
1299 /**
1300  *	dev_disable_lro - disable Large Receive Offload on a device
1301  *	@dev: device
1302  *
1303  *	Disable Large Receive Offload (LRO) on a net device.  Must be
1304  *	called under RTNL.  This is needed if received packets may be
1305  *	forwarded to another interface.
1306  */
dev_disable_lro(struct net_device * dev)1307 void dev_disable_lro(struct net_device *dev)
1308 {
1309 	u32 flags;
1310 
1311 	if (dev->ethtool_ops && dev->ethtool_ops->get_flags)
1312 		flags = dev->ethtool_ops->get_flags(dev);
1313 	else
1314 		flags = ethtool_op_get_flags(dev);
1315 
1316 	if (!(flags & ETH_FLAG_LRO))
1317 		return;
1318 
1319 	__ethtool_set_flags(dev, flags & ~ETH_FLAG_LRO);
1320 	WARN_ON(dev->features & NETIF_F_LRO);
1321 }
1322 EXPORT_SYMBOL(dev_disable_lro);
1323 
1324 
1325 static int dev_boot_phase = 1;
1326 
1327 /**
1328  *	register_netdevice_notifier - register a network notifier block
1329  *	@nb: notifier
1330  *
1331  *	Register a notifier to be called when network device events occur.
1332  *	The notifier passed is linked into the kernel structures and must
1333  *	not be reused until it has been unregistered. A negative errno code
1334  *	is returned on a failure.
1335  *
1336  * 	When registered all registration and up events are replayed
1337  *	to the new notifier to allow device to have a race free
1338  *	view of the network device list.
1339  */
1340 
register_netdevice_notifier(struct notifier_block * nb)1341 int register_netdevice_notifier(struct notifier_block *nb)
1342 {
1343 	struct net_device *dev;
1344 	struct net_device *last;
1345 	struct net *net;
1346 	int err;
1347 
1348 	rtnl_lock();
1349 	err = raw_notifier_chain_register(&netdev_chain, nb);
1350 	if (err)
1351 		goto unlock;
1352 	if (dev_boot_phase)
1353 		goto unlock;
1354 	for_each_net(net) {
1355 		for_each_netdev(net, dev) {
1356 			err = nb->notifier_call(nb, NETDEV_REGISTER, dev);
1357 			err = notifier_to_errno(err);
1358 			if (err)
1359 				goto rollback;
1360 
1361 			if (!(dev->flags & IFF_UP))
1362 				continue;
1363 
1364 			nb->notifier_call(nb, NETDEV_UP, dev);
1365 		}
1366 	}
1367 
1368 unlock:
1369 	rtnl_unlock();
1370 	return err;
1371 
1372 rollback:
1373 	last = dev;
1374 	for_each_net(net) {
1375 		for_each_netdev(net, dev) {
1376 			if (dev == last)
1377 				break;
1378 
1379 			if (dev->flags & IFF_UP) {
1380 				nb->notifier_call(nb, NETDEV_GOING_DOWN, dev);
1381 				nb->notifier_call(nb, NETDEV_DOWN, dev);
1382 			}
1383 			nb->notifier_call(nb, NETDEV_UNREGISTER, dev);
1384 			nb->notifier_call(nb, NETDEV_UNREGISTER_BATCH, dev);
1385 		}
1386 	}
1387 
1388 	raw_notifier_chain_unregister(&netdev_chain, nb);
1389 	goto unlock;
1390 }
1391 EXPORT_SYMBOL(register_netdevice_notifier);
1392 
1393 /**
1394  *	unregister_netdevice_notifier - unregister a network notifier block
1395  *	@nb: notifier
1396  *
1397  *	Unregister a notifier previously registered by
1398  *	register_netdevice_notifier(). The notifier is unlinked into the
1399  *	kernel structures and may then be reused. A negative errno code
1400  *	is returned on a failure.
1401  */
1402 
unregister_netdevice_notifier(struct notifier_block * nb)1403 int unregister_netdevice_notifier(struct notifier_block *nb)
1404 {
1405 	int err;
1406 
1407 	rtnl_lock();
1408 	err = raw_notifier_chain_unregister(&netdev_chain, nb);
1409 	rtnl_unlock();
1410 	return err;
1411 }
1412 EXPORT_SYMBOL(unregister_netdevice_notifier);
1413 
1414 /**
1415  *	call_netdevice_notifiers - call all network notifier blocks
1416  *      @val: value passed unmodified to notifier function
1417  *      @dev: net_device pointer passed unmodified to notifier function
1418  *
1419  *	Call all network notifier blocks.  Parameters and return value
1420  *	are as for raw_notifier_call_chain().
1421  */
1422 
call_netdevice_notifiers(unsigned long val,struct net_device * dev)1423 int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
1424 {
1425 	ASSERT_RTNL();
1426 	return raw_notifier_call_chain(&netdev_chain, val, dev);
1427 }
1428 EXPORT_SYMBOL(call_netdevice_notifiers);
1429 
1430 /* When > 0 there are consumers of rx skb time stamps */
1431 static atomic_t netstamp_needed = ATOMIC_INIT(0);
1432 
net_enable_timestamp(void)1433 void net_enable_timestamp(void)
1434 {
1435 	atomic_inc(&netstamp_needed);
1436 }
1437 EXPORT_SYMBOL(net_enable_timestamp);
1438 
net_disable_timestamp(void)1439 void net_disable_timestamp(void)
1440 {
1441 	atomic_dec(&netstamp_needed);
1442 }
1443 EXPORT_SYMBOL(net_disable_timestamp);
1444 
net_timestamp_set(struct sk_buff * skb)1445 static inline void net_timestamp_set(struct sk_buff *skb)
1446 {
1447 	if (atomic_read(&netstamp_needed))
1448 		__net_timestamp(skb);
1449 	else
1450 		skb->tstamp.tv64 = 0;
1451 }
1452 
net_timestamp_check(struct sk_buff * skb)1453 static inline void net_timestamp_check(struct sk_buff *skb)
1454 {
1455 	if (!skb->tstamp.tv64 && atomic_read(&netstamp_needed))
1456 		__net_timestamp(skb);
1457 }
1458 
is_skb_forwardable(struct net_device * dev,struct sk_buff * skb)1459 static inline bool is_skb_forwardable(struct net_device *dev,
1460 				      struct sk_buff *skb)
1461 {
1462 	unsigned int len;
1463 
1464 	if (!(dev->flags & IFF_UP))
1465 		return false;
1466 
1467 	len = dev->mtu + dev->hard_header_len + VLAN_HLEN;
1468 	if (skb->len <= len)
1469 		return true;
1470 
1471 	/* if TSO is enabled, we don't care about the length as the packet
1472 	 * could be forwarded without being segmented before
1473 	 */
1474 	if (skb_is_gso(skb))
1475 		return true;
1476 
1477 	return false;
1478 }
1479 
1480 /**
1481  * dev_forward_skb - loopback an skb to another netif
1482  *
1483  * @dev: destination network device
1484  * @skb: buffer to forward
1485  *
1486  * return values:
1487  *	NET_RX_SUCCESS	(no congestion)
1488  *	NET_RX_DROP     (packet was dropped, but freed)
1489  *
1490  * dev_forward_skb can be used for injecting an skb from the
1491  * start_xmit function of one device into the receive queue
1492  * of another device.
1493  *
1494  * The receiving device may be in another namespace, so
1495  * we have to clear all information in the skb that could
1496  * impact namespace isolation.
1497  */
dev_forward_skb(struct net_device * dev,struct sk_buff * skb)1498 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
1499 {
1500 	skb_orphan(skb);
1501 	nf_reset(skb);
1502 
1503 	if (unlikely(!is_skb_forwardable(dev, skb))) {
1504 		atomic_long_inc(&dev->rx_dropped);
1505 		kfree_skb(skb);
1506 		return NET_RX_DROP;
1507 	}
1508 	skb_set_dev(skb, dev);
1509 	skb->tstamp.tv64 = 0;
1510 	skb->pkt_type = PACKET_HOST;
1511 	skb->protocol = eth_type_trans(skb, dev);
1512 	return netif_rx(skb);
1513 }
1514 EXPORT_SYMBOL_GPL(dev_forward_skb);
1515 
deliver_skb(struct sk_buff * skb,struct packet_type * pt_prev,struct net_device * orig_dev)1516 static inline int deliver_skb(struct sk_buff *skb,
1517 			      struct packet_type *pt_prev,
1518 			      struct net_device *orig_dev)
1519 {
1520 	atomic_inc(&skb->users);
1521 	return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
1522 }
1523 
1524 /*
1525  *	Support routine. Sends outgoing frames to any network
1526  *	taps currently in use.
1527  */
1528 
dev_queue_xmit_nit(struct sk_buff * skb,struct net_device * dev)1529 static void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
1530 {
1531 	struct packet_type *ptype;
1532 	struct sk_buff *skb2 = NULL;
1533 	struct packet_type *pt_prev = NULL;
1534 
1535 	rcu_read_lock();
1536 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
1537 		/* Never send packets back to the socket
1538 		 * they originated from - MvS (miquels@drinkel.ow.org)
1539 		 */
1540 		if ((ptype->dev == dev || !ptype->dev) &&
1541 		    (ptype->af_packet_priv == NULL ||
1542 		     (struct sock *)ptype->af_packet_priv != skb->sk)) {
1543 			if (pt_prev) {
1544 				deliver_skb(skb2, pt_prev, skb->dev);
1545 				pt_prev = ptype;
1546 				continue;
1547 			}
1548 
1549 			skb2 = skb_clone(skb, GFP_ATOMIC);
1550 			if (!skb2)
1551 				break;
1552 
1553 			net_timestamp_set(skb2);
1554 
1555 			/* skb->nh should be correctly
1556 			   set by sender, so that the second statement is
1557 			   just protection against buggy protocols.
1558 			 */
1559 			skb_reset_mac_header(skb2);
1560 
1561 			if (skb_network_header(skb2) < skb2->data ||
1562 			    skb2->network_header > skb2->tail) {
1563 				if (net_ratelimit())
1564 					printk(KERN_CRIT "protocol %04x is "
1565 					       "buggy, dev %s\n",
1566 					       ntohs(skb2->protocol),
1567 					       dev->name);
1568 				skb_reset_network_header(skb2);
1569 			}
1570 
1571 			skb2->transport_header = skb2->network_header;
1572 			skb2->pkt_type = PACKET_OUTGOING;
1573 			pt_prev = ptype;
1574 		}
1575 	}
1576 	if (pt_prev)
1577 		pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
1578 	rcu_read_unlock();
1579 }
1580 
1581 /* netif_setup_tc - Handle tc mappings on real_num_tx_queues change
1582  * @dev: Network device
1583  * @txq: number of queues available
1584  *
1585  * If real_num_tx_queues is changed the tc mappings may no longer be
1586  * valid. To resolve this verify the tc mapping remains valid and if
1587  * not NULL the mapping. With no priorities mapping to this
1588  * offset/count pair it will no longer be used. In the worst case TC0
1589  * is invalid nothing can be done so disable priority mappings. If is
1590  * expected that drivers will fix this mapping if they can before
1591  * calling netif_set_real_num_tx_queues.
1592  */
netif_setup_tc(struct net_device * dev,unsigned int txq)1593 static void netif_setup_tc(struct net_device *dev, unsigned int txq)
1594 {
1595 	int i;
1596 	struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
1597 
1598 	/* If TC0 is invalidated disable TC mapping */
1599 	if (tc->offset + tc->count > txq) {
1600 		pr_warning("Number of in use tx queues changed "
1601 			   "invalidating tc mappings. Priority "
1602 			   "traffic classification disabled!\n");
1603 		dev->num_tc = 0;
1604 		return;
1605 	}
1606 
1607 	/* Invalidated prio to tc mappings set to TC0 */
1608 	for (i = 1; i < TC_BITMASK + 1; i++) {
1609 		int q = netdev_get_prio_tc_map(dev, i);
1610 
1611 		tc = &dev->tc_to_txq[q];
1612 		if (tc->offset + tc->count > txq) {
1613 			pr_warning("Number of in use tx queues "
1614 				   "changed. Priority %i to tc "
1615 				   "mapping %i is no longer valid "
1616 				   "setting map to 0\n",
1617 				   i, q);
1618 			netdev_set_prio_tc_map(dev, i, 0);
1619 		}
1620 	}
1621 }
1622 
1623 /*
1624  * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
1625  * greater then real_num_tx_queues stale skbs on the qdisc must be flushed.
1626  */
netif_set_real_num_tx_queues(struct net_device * dev,unsigned int txq)1627 int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
1628 {
1629 	int rc;
1630 
1631 	if (txq < 1 || txq > dev->num_tx_queues)
1632 		return -EINVAL;
1633 
1634 	if (dev->reg_state == NETREG_REGISTERED ||
1635 	    dev->reg_state == NETREG_UNREGISTERING) {
1636 		ASSERT_RTNL();
1637 
1638 		rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
1639 						  txq);
1640 		if (rc)
1641 			return rc;
1642 
1643 		if (dev->num_tc)
1644 			netif_setup_tc(dev, txq);
1645 
1646 		if (txq < dev->real_num_tx_queues)
1647 			qdisc_reset_all_tx_gt(dev, txq);
1648 	}
1649 
1650 	dev->real_num_tx_queues = txq;
1651 	return 0;
1652 }
1653 EXPORT_SYMBOL(netif_set_real_num_tx_queues);
1654 
1655 #ifdef CONFIG_RPS
1656 /**
1657  *	netif_set_real_num_rx_queues - set actual number of RX queues used
1658  *	@dev: Network device
1659  *	@rxq: Actual number of RX queues
1660  *
1661  *	This must be called either with the rtnl_lock held or before
1662  *	registration of the net device.  Returns 0 on success, or a
1663  *	negative error code.  If called before registration, it always
1664  *	succeeds.
1665  */
netif_set_real_num_rx_queues(struct net_device * dev,unsigned int rxq)1666 int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
1667 {
1668 	int rc;
1669 
1670 	if (rxq < 1 || rxq > dev->num_rx_queues)
1671 		return -EINVAL;
1672 
1673 	if (dev->reg_state == NETREG_REGISTERED) {
1674 		ASSERT_RTNL();
1675 
1676 		rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
1677 						  rxq);
1678 		if (rc)
1679 			return rc;
1680 	}
1681 
1682 	dev->real_num_rx_queues = rxq;
1683 	return 0;
1684 }
1685 EXPORT_SYMBOL(netif_set_real_num_rx_queues);
1686 #endif
1687 
__netif_reschedule(struct Qdisc * q)1688 static inline void __netif_reschedule(struct Qdisc *q)
1689 {
1690 	struct softnet_data *sd;
1691 	unsigned long flags;
1692 
1693 	local_irq_save(flags);
1694 	sd = &__get_cpu_var(softnet_data);
1695 	q->next_sched = NULL;
1696 	*sd->output_queue_tailp = q;
1697 	sd->output_queue_tailp = &q->next_sched;
1698 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
1699 	local_irq_restore(flags);
1700 }
1701 
__netif_schedule(struct Qdisc * q)1702 void __netif_schedule(struct Qdisc *q)
1703 {
1704 	if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
1705 		__netif_reschedule(q);
1706 }
1707 EXPORT_SYMBOL(__netif_schedule);
1708 
dev_kfree_skb_irq(struct sk_buff * skb)1709 void dev_kfree_skb_irq(struct sk_buff *skb)
1710 {
1711 	if (atomic_dec_and_test(&skb->users)) {
1712 		struct softnet_data *sd;
1713 		unsigned long flags;
1714 
1715 		local_irq_save(flags);
1716 		sd = &__get_cpu_var(softnet_data);
1717 		skb->next = sd->completion_queue;
1718 		sd->completion_queue = skb;
1719 		raise_softirq_irqoff(NET_TX_SOFTIRQ);
1720 		local_irq_restore(flags);
1721 	}
1722 }
1723 EXPORT_SYMBOL(dev_kfree_skb_irq);
1724 
dev_kfree_skb_any(struct sk_buff * skb)1725 void dev_kfree_skb_any(struct sk_buff *skb)
1726 {
1727 	if (in_irq() || irqs_disabled())
1728 		dev_kfree_skb_irq(skb);
1729 	else
1730 		dev_kfree_skb(skb);
1731 }
1732 EXPORT_SYMBOL(dev_kfree_skb_any);
1733 
1734 
1735 /**
1736  * netif_device_detach - mark device as removed
1737  * @dev: network device
1738  *
1739  * Mark device as removed from system and therefore no longer available.
1740  */
netif_device_detach(struct net_device * dev)1741 void netif_device_detach(struct net_device *dev)
1742 {
1743 	if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
1744 	    netif_running(dev)) {
1745 		netif_tx_stop_all_queues(dev);
1746 	}
1747 }
1748 EXPORT_SYMBOL(netif_device_detach);
1749 
1750 /**
1751  * netif_device_attach - mark device as attached
1752  * @dev: network device
1753  *
1754  * Mark device as attached from system and restart if needed.
1755  */
netif_device_attach(struct net_device * dev)1756 void netif_device_attach(struct net_device *dev)
1757 {
1758 	if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
1759 	    netif_running(dev)) {
1760 		netif_tx_wake_all_queues(dev);
1761 		__netdev_watchdog_up(dev);
1762 	}
1763 }
1764 EXPORT_SYMBOL(netif_device_attach);
1765 
1766 /**
1767  * skb_dev_set -- assign a new device to a buffer
1768  * @skb: buffer for the new device
1769  * @dev: network device
1770  *
1771  * If an skb is owned by a device already, we have to reset
1772  * all data private to the namespace a device belongs to
1773  * before assigning it a new device.
1774  */
1775 #ifdef CONFIG_NET_NS
skb_set_dev(struct sk_buff * skb,struct net_device * dev)1776 void skb_set_dev(struct sk_buff *skb, struct net_device *dev)
1777 {
1778 	skb_dst_drop(skb);
1779 	if (skb->dev && !net_eq(dev_net(skb->dev), dev_net(dev))) {
1780 		secpath_reset(skb);
1781 		nf_reset(skb);
1782 		skb_init_secmark(skb);
1783 		skb->mark = 0;
1784 		skb->priority = 0;
1785 		skb->nf_trace = 0;
1786 		skb->ipvs_property = 0;
1787 #ifdef CONFIG_NET_SCHED
1788 		skb->tc_index = 0;
1789 #endif
1790 	}
1791 	skb->dev = dev;
1792 }
1793 EXPORT_SYMBOL(skb_set_dev);
1794 #endif /* CONFIG_NET_NS */
1795 
1796 /*
1797  * Invalidate hardware checksum when packet is to be mangled, and
1798  * complete checksum manually on outgoing path.
1799  */
skb_checksum_help(struct sk_buff * skb)1800 int skb_checksum_help(struct sk_buff *skb)
1801 {
1802 	__wsum csum;
1803 	int ret = 0, offset;
1804 
1805 	if (skb->ip_summed == CHECKSUM_COMPLETE)
1806 		goto out_set_summed;
1807 
1808 	if (unlikely(skb_shinfo(skb)->gso_size)) {
1809 		/* Let GSO fix up the checksum. */
1810 		goto out_set_summed;
1811 	}
1812 
1813 	offset = skb_checksum_start_offset(skb);
1814 	BUG_ON(offset >= skb_headlen(skb));
1815 	csum = skb_checksum(skb, offset, skb->len - offset, 0);
1816 
1817 	offset += skb->csum_offset;
1818 	BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb));
1819 
1820 	if (skb_cloned(skb) &&
1821 	    !skb_clone_writable(skb, offset + sizeof(__sum16))) {
1822 		ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
1823 		if (ret)
1824 			goto out;
1825 	}
1826 
1827 	*(__sum16 *)(skb->data + offset) = csum_fold(csum);
1828 out_set_summed:
1829 	skb->ip_summed = CHECKSUM_NONE;
1830 out:
1831 	return ret;
1832 }
1833 EXPORT_SYMBOL(skb_checksum_help);
1834 
1835 /**
1836  *	skb_gso_segment - Perform segmentation on skb.
1837  *	@skb: buffer to segment
1838  *	@features: features for the output path (see dev->features)
1839  *
1840  *	This function segments the given skb and returns a list of segments.
1841  *
1842  *	It may return NULL if the skb requires no segmentation.  This is
1843  *	only possible when GSO is used for verifying header integrity.
1844  */
skb_gso_segment(struct sk_buff * skb,u32 features)1845 struct sk_buff *skb_gso_segment(struct sk_buff *skb, u32 features)
1846 {
1847 	struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT);
1848 	struct packet_type *ptype;
1849 	__be16 type = skb->protocol;
1850 	int vlan_depth = ETH_HLEN;
1851 	int err;
1852 
1853 	while (type == htons(ETH_P_8021Q)) {
1854 		struct vlan_hdr *vh;
1855 
1856 		if (unlikely(!pskb_may_pull(skb, vlan_depth + VLAN_HLEN)))
1857 			return ERR_PTR(-EINVAL);
1858 
1859 		vh = (struct vlan_hdr *)(skb->data + vlan_depth);
1860 		type = vh->h_vlan_encapsulated_proto;
1861 		vlan_depth += VLAN_HLEN;
1862 	}
1863 
1864 	skb_reset_mac_header(skb);
1865 	skb->mac_len = skb->network_header - skb->mac_header;
1866 	__skb_pull(skb, skb->mac_len);
1867 
1868 	if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
1869 		struct net_device *dev = skb->dev;
1870 		struct ethtool_drvinfo info = {};
1871 
1872 		if (dev && dev->ethtool_ops && dev->ethtool_ops->get_drvinfo)
1873 			dev->ethtool_ops->get_drvinfo(dev, &info);
1874 
1875 		WARN(1, "%s: caps=(0x%lx, 0x%lx) len=%d data_len=%d ip_summed=%d\n",
1876 		     info.driver, dev ? dev->features : 0L,
1877 		     skb->sk ? skb->sk->sk_route_caps : 0L,
1878 		     skb->len, skb->data_len, skb->ip_summed);
1879 
1880 		if (skb_header_cloned(skb) &&
1881 		    (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
1882 			return ERR_PTR(err);
1883 	}
1884 
1885 	rcu_read_lock();
1886 	list_for_each_entry_rcu(ptype,
1887 			&ptype_base[ntohs(type) & PTYPE_HASH_MASK], list) {
1888 		if (ptype->type == type && !ptype->dev && ptype->gso_segment) {
1889 			if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
1890 				err = ptype->gso_send_check(skb);
1891 				segs = ERR_PTR(err);
1892 				if (err || skb_gso_ok(skb, features))
1893 					break;
1894 				__skb_push(skb, (skb->data -
1895 						 skb_network_header(skb)));
1896 			}
1897 			segs = ptype->gso_segment(skb, features);
1898 			break;
1899 		}
1900 	}
1901 	rcu_read_unlock();
1902 
1903 	__skb_push(skb, skb->data - skb_mac_header(skb));
1904 
1905 	return segs;
1906 }
1907 EXPORT_SYMBOL(skb_gso_segment);
1908 
1909 /* Take action when hardware reception checksum errors are detected. */
1910 #ifdef CONFIG_BUG
netdev_rx_csum_fault(struct net_device * dev)1911 void netdev_rx_csum_fault(struct net_device *dev)
1912 {
1913 	if (net_ratelimit()) {
1914 		printk(KERN_ERR "%s: hw csum failure.\n",
1915 			dev ? dev->name : "<unknown>");
1916 		dump_stack();
1917 	}
1918 }
1919 EXPORT_SYMBOL(netdev_rx_csum_fault);
1920 #endif
1921 
1922 /* Actually, we should eliminate this check as soon as we know, that:
1923  * 1. IOMMU is present and allows to map all the memory.
1924  * 2. No high memory really exists on this machine.
1925  */
1926 
illegal_highdma(struct net_device * dev,struct sk_buff * skb)1927 static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
1928 {
1929 #ifdef CONFIG_HIGHMEM
1930 	int i;
1931 	if (!(dev->features & NETIF_F_HIGHDMA)) {
1932 		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
1933 			if (PageHighMem(skb_shinfo(skb)->frags[i].page))
1934 				return 1;
1935 	}
1936 
1937 	if (PCI_DMA_BUS_IS_PHYS) {
1938 		struct device *pdev = dev->dev.parent;
1939 
1940 		if (!pdev)
1941 			return 0;
1942 		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1943 			dma_addr_t addr = page_to_phys(skb_shinfo(skb)->frags[i].page);
1944 			if (!pdev->dma_mask || addr + PAGE_SIZE - 1 > *pdev->dma_mask)
1945 				return 1;
1946 		}
1947 	}
1948 #endif
1949 	return 0;
1950 }
1951 
1952 struct dev_gso_cb {
1953 	void (*destructor)(struct sk_buff *skb);
1954 };
1955 
1956 #define DEV_GSO_CB(skb) ((struct dev_gso_cb *)(skb)->cb)
1957 
dev_gso_skb_destructor(struct sk_buff * skb)1958 static void dev_gso_skb_destructor(struct sk_buff *skb)
1959 {
1960 	struct dev_gso_cb *cb;
1961 
1962 	do {
1963 		struct sk_buff *nskb = skb->next;
1964 
1965 		skb->next = nskb->next;
1966 		nskb->next = NULL;
1967 		kfree_skb(nskb);
1968 	} while (skb->next);
1969 
1970 	cb = DEV_GSO_CB(skb);
1971 	if (cb->destructor)
1972 		cb->destructor(skb);
1973 }
1974 
1975 /**
1976  *	dev_gso_segment - Perform emulated hardware segmentation on skb.
1977  *	@skb: buffer to segment
1978  *	@features: device features as applicable to this skb
1979  *
1980  *	This function segments the given skb and stores the list of segments
1981  *	in skb->next.
1982  */
dev_gso_segment(struct sk_buff * skb,int features)1983 static int dev_gso_segment(struct sk_buff *skb, int features)
1984 {
1985 	struct sk_buff *segs;
1986 
1987 	segs = skb_gso_segment(skb, features);
1988 
1989 	/* Verifying header integrity only. */
1990 	if (!segs)
1991 		return 0;
1992 
1993 	if (IS_ERR(segs))
1994 		return PTR_ERR(segs);
1995 
1996 	skb->next = segs;
1997 	DEV_GSO_CB(skb)->destructor = skb->destructor;
1998 	skb->destructor = dev_gso_skb_destructor;
1999 
2000 	return 0;
2001 }
2002 
2003 /*
2004  * Try to orphan skb early, right before transmission by the device.
2005  * We cannot orphan skb if tx timestamp is requested or the sk-reference
2006  * is needed on driver level for other reasons, e.g. see net/can/raw.c
2007  */
skb_orphan_try(struct sk_buff * skb)2008 static inline void skb_orphan_try(struct sk_buff *skb)
2009 {
2010 	struct sock *sk = skb->sk;
2011 
2012 	if (sk && !skb_shinfo(skb)->tx_flags) {
2013 		/* skb_tx_hash() wont be able to get sk.
2014 		 * We copy sk_hash into skb->rxhash
2015 		 */
2016 		if (!skb->rxhash)
2017 			skb->rxhash = sk->sk_hash;
2018 		skb_orphan(skb);
2019 	}
2020 }
2021 
can_checksum_protocol(unsigned long features,__be16 protocol)2022 static bool can_checksum_protocol(unsigned long features, __be16 protocol)
2023 {
2024 	return ((features & NETIF_F_GEN_CSUM) ||
2025 		((features & NETIF_F_V4_CSUM) &&
2026 		 protocol == htons(ETH_P_IP)) ||
2027 		((features & NETIF_F_V6_CSUM) &&
2028 		 protocol == htons(ETH_P_IPV6)) ||
2029 		((features & NETIF_F_FCOE_CRC) &&
2030 		 protocol == htons(ETH_P_FCOE)));
2031 }
2032 
harmonize_features(struct sk_buff * skb,__be16 protocol,u32 features)2033 static u32 harmonize_features(struct sk_buff *skb, __be16 protocol, u32 features)
2034 {
2035 	if (!can_checksum_protocol(features, protocol)) {
2036 		features &= ~NETIF_F_ALL_CSUM;
2037 		features &= ~NETIF_F_SG;
2038 	} else if (illegal_highdma(skb->dev, skb)) {
2039 		features &= ~NETIF_F_SG;
2040 	}
2041 
2042 	return features;
2043 }
2044 
netif_skb_features(struct sk_buff * skb)2045 u32 netif_skb_features(struct sk_buff *skb)
2046 {
2047 	__be16 protocol = skb->protocol;
2048 	u32 features = skb->dev->features;
2049 
2050 	if (protocol == htons(ETH_P_8021Q)) {
2051 		struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
2052 		protocol = veh->h_vlan_encapsulated_proto;
2053 	} else if (!vlan_tx_tag_present(skb)) {
2054 		return harmonize_features(skb, protocol, features);
2055 	}
2056 
2057 	features &= (skb->dev->vlan_features | NETIF_F_HW_VLAN_TX);
2058 
2059 	if (protocol != htons(ETH_P_8021Q)) {
2060 		return harmonize_features(skb, protocol, features);
2061 	} else {
2062 		features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST |
2063 				NETIF_F_GEN_CSUM | NETIF_F_HW_VLAN_TX;
2064 		return harmonize_features(skb, protocol, features);
2065 	}
2066 }
2067 EXPORT_SYMBOL(netif_skb_features);
2068 
2069 /*
2070  * Returns true if either:
2071  *	1. skb has frag_list and the device doesn't support FRAGLIST, or
2072  *	2. skb is fragmented and the device does not support SG, or if
2073  *	   at least one of fragments is in highmem and device does not
2074  *	   support DMA from it.
2075  */
skb_needs_linearize(struct sk_buff * skb,int features)2076 static inline int skb_needs_linearize(struct sk_buff *skb,
2077 				      int features)
2078 {
2079 	return skb_is_nonlinear(skb) &&
2080 			((skb_has_frag_list(skb) &&
2081 				!(features & NETIF_F_FRAGLIST)) ||
2082 			(skb_shinfo(skb)->nr_frags &&
2083 				!(features & NETIF_F_SG)));
2084 }
2085 
dev_hard_start_xmit(struct sk_buff * skb,struct net_device * dev,struct netdev_queue * txq)2086 int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
2087 			struct netdev_queue *txq)
2088 {
2089 	const struct net_device_ops *ops = dev->netdev_ops;
2090 	int rc = NETDEV_TX_OK;
2091 
2092 	if (likely(!skb->next)) {
2093 		u32 features;
2094 
2095 		/*
2096 		 * If device doesn't need skb->dst, release it right now while
2097 		 * its hot in this cpu cache
2098 		 */
2099 		if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
2100 			skb_dst_drop(skb);
2101 
2102 		if (!list_empty(&ptype_all))
2103 			dev_queue_xmit_nit(skb, dev);
2104 
2105 		skb_orphan_try(skb);
2106 
2107 		features = netif_skb_features(skb);
2108 
2109 		if (vlan_tx_tag_present(skb) &&
2110 		    !(features & NETIF_F_HW_VLAN_TX)) {
2111 			skb = __vlan_put_tag(skb, vlan_tx_tag_get(skb));
2112 			if (unlikely(!skb))
2113 				goto out;
2114 
2115 			skb->vlan_tci = 0;
2116 		}
2117 
2118 		if (netif_needs_gso(skb, features)) {
2119 			if (unlikely(dev_gso_segment(skb, features)))
2120 				goto out_kfree_skb;
2121 			if (skb->next)
2122 				goto gso;
2123 		} else {
2124 			if (skb_needs_linearize(skb, features) &&
2125 			    __skb_linearize(skb))
2126 				goto out_kfree_skb;
2127 
2128 			/* If packet is not checksummed and device does not
2129 			 * support checksumming for this protocol, complete
2130 			 * checksumming here.
2131 			 */
2132 			if (skb->ip_summed == CHECKSUM_PARTIAL) {
2133 				skb_set_transport_header(skb,
2134 					skb_checksum_start_offset(skb));
2135 				if (!(features & NETIF_F_ALL_CSUM) &&
2136 				     skb_checksum_help(skb))
2137 					goto out_kfree_skb;
2138 			}
2139 		}
2140 
2141 		rc = ops->ndo_start_xmit(skb, dev);
2142 		trace_net_dev_xmit(skb, rc);
2143 		if (rc == NETDEV_TX_OK)
2144 			txq_trans_update(txq);
2145 		return rc;
2146 	}
2147 
2148 gso:
2149 	do {
2150 		struct sk_buff *nskb = skb->next;
2151 
2152 		skb->next = nskb->next;
2153 		nskb->next = NULL;
2154 
2155 		/*
2156 		 * If device doesn't need nskb->dst, release it right now while
2157 		 * its hot in this cpu cache
2158 		 */
2159 		if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
2160 			skb_dst_drop(nskb);
2161 
2162 		rc = ops->ndo_start_xmit(nskb, dev);
2163 		trace_net_dev_xmit(nskb, rc);
2164 		if (unlikely(rc != NETDEV_TX_OK)) {
2165 			if (rc & ~NETDEV_TX_MASK)
2166 				goto out_kfree_gso_skb;
2167 			nskb->next = skb->next;
2168 			skb->next = nskb;
2169 			return rc;
2170 		}
2171 		txq_trans_update(txq);
2172 		if (unlikely(netif_tx_queue_stopped(txq) && skb->next))
2173 			return NETDEV_TX_BUSY;
2174 	} while (skb->next);
2175 
2176 out_kfree_gso_skb:
2177 	if (likely(skb->next == NULL))
2178 		skb->destructor = DEV_GSO_CB(skb)->destructor;
2179 out_kfree_skb:
2180 	kfree_skb(skb);
2181 out:
2182 	return rc;
2183 }
2184 
2185 static u32 hashrnd __read_mostly;
2186 
2187 /*
2188  * Returns a Tx hash based on the given packet descriptor a Tx queues' number
2189  * to be used as a distribution range.
2190  */
__skb_tx_hash(const struct net_device * dev,const struct sk_buff * skb,unsigned int num_tx_queues)2191 u16 __skb_tx_hash(const struct net_device *dev, const struct sk_buff *skb,
2192 		  unsigned int num_tx_queues)
2193 {
2194 	u32 hash;
2195 	u16 qoffset = 0;
2196 	u16 qcount = num_tx_queues;
2197 
2198 	if (skb_rx_queue_recorded(skb)) {
2199 		hash = skb_get_rx_queue(skb);
2200 		while (unlikely(hash >= num_tx_queues))
2201 			hash -= num_tx_queues;
2202 		return hash;
2203 	}
2204 
2205 	if (dev->num_tc) {
2206 		u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
2207 		qoffset = dev->tc_to_txq[tc].offset;
2208 		qcount = dev->tc_to_txq[tc].count;
2209 	}
2210 
2211 	if (skb->sk && skb->sk->sk_hash)
2212 		hash = skb->sk->sk_hash;
2213 	else
2214 		hash = (__force u16) skb->protocol ^ skb->rxhash;
2215 	hash = jhash_1word(hash, hashrnd);
2216 
2217 	return (u16) (((u64) hash * qcount) >> 32) + qoffset;
2218 }
2219 EXPORT_SYMBOL(__skb_tx_hash);
2220 
dev_cap_txqueue(struct net_device * dev,u16 queue_index)2221 static inline u16 dev_cap_txqueue(struct net_device *dev, u16 queue_index)
2222 {
2223 	if (unlikely(queue_index >= dev->real_num_tx_queues)) {
2224 		if (net_ratelimit()) {
2225 			pr_warning("%s selects TX queue %d, but "
2226 				"real number of TX queues is %d\n",
2227 				dev->name, queue_index, dev->real_num_tx_queues);
2228 		}
2229 		return 0;
2230 	}
2231 	return queue_index;
2232 }
2233 
get_xps_queue(struct net_device * dev,struct sk_buff * skb)2234 static inline int get_xps_queue(struct net_device *dev, struct sk_buff *skb)
2235 {
2236 #ifdef CONFIG_XPS
2237 	struct xps_dev_maps *dev_maps;
2238 	struct xps_map *map;
2239 	int queue_index = -1;
2240 
2241 	rcu_read_lock();
2242 	dev_maps = rcu_dereference(dev->xps_maps);
2243 	if (dev_maps) {
2244 		map = rcu_dereference(
2245 		    dev_maps->cpu_map[raw_smp_processor_id()]);
2246 		if (map) {
2247 			if (map->len == 1)
2248 				queue_index = map->queues[0];
2249 			else {
2250 				u32 hash;
2251 				if (skb->sk && skb->sk->sk_hash)
2252 					hash = skb->sk->sk_hash;
2253 				else
2254 					hash = (__force u16) skb->protocol ^
2255 					    skb->rxhash;
2256 				hash = jhash_1word(hash, hashrnd);
2257 				queue_index = map->queues[
2258 				    ((u64)hash * map->len) >> 32];
2259 			}
2260 			if (unlikely(queue_index >= dev->real_num_tx_queues))
2261 				queue_index = -1;
2262 		}
2263 	}
2264 	rcu_read_unlock();
2265 
2266 	return queue_index;
2267 #else
2268 	return -1;
2269 #endif
2270 }
2271 
dev_pick_tx(struct net_device * dev,struct sk_buff * skb)2272 static struct netdev_queue *dev_pick_tx(struct net_device *dev,
2273 					struct sk_buff *skb)
2274 {
2275 	int queue_index;
2276 	const struct net_device_ops *ops = dev->netdev_ops;
2277 
2278 	if (dev->real_num_tx_queues == 1)
2279 		queue_index = 0;
2280 	else if (ops->ndo_select_queue) {
2281 		queue_index = ops->ndo_select_queue(dev, skb);
2282 		queue_index = dev_cap_txqueue(dev, queue_index);
2283 	} else {
2284 		struct sock *sk = skb->sk;
2285 		queue_index = sk_tx_queue_get(sk);
2286 
2287 		if (queue_index < 0 || skb->ooo_okay ||
2288 		    queue_index >= dev->real_num_tx_queues) {
2289 			int old_index = queue_index;
2290 
2291 			queue_index = get_xps_queue(dev, skb);
2292 			if (queue_index < 0)
2293 				queue_index = skb_tx_hash(dev, skb);
2294 
2295 			if (queue_index != old_index && sk) {
2296 				struct dst_entry *dst =
2297 				    rcu_dereference_check(sk->sk_dst_cache, 1);
2298 
2299 				if (dst && skb_dst(skb) == dst)
2300 					sk_tx_queue_set(sk, queue_index);
2301 			}
2302 		}
2303 	}
2304 
2305 	skb_set_queue_mapping(skb, queue_index);
2306 	return netdev_get_tx_queue(dev, queue_index);
2307 }
2308 
__dev_xmit_skb(struct sk_buff * skb,struct Qdisc * q,struct net_device * dev,struct netdev_queue * txq)2309 static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
2310 				 struct net_device *dev,
2311 				 struct netdev_queue *txq)
2312 {
2313 	spinlock_t *root_lock = qdisc_lock(q);
2314 	bool contended;
2315 	int rc;
2316 
2317 	qdisc_skb_cb(skb)->pkt_len = skb->len;
2318 	qdisc_calculate_pkt_len(skb, q);
2319 	/*
2320 	 * Heuristic to force contended enqueues to serialize on a
2321 	 * separate lock before trying to get qdisc main lock.
2322 	 * This permits __QDISC_STATE_RUNNING owner to get the lock more often
2323 	 * and dequeue packets faster.
2324 	 */
2325 	contended = qdisc_is_running(q);
2326 	if (unlikely(contended))
2327 		spin_lock(&q->busylock);
2328 
2329 	spin_lock(root_lock);
2330 	if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
2331 		kfree_skb(skb);
2332 		rc = NET_XMIT_DROP;
2333 	} else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
2334 		   qdisc_run_begin(q)) {
2335 		/*
2336 		 * This is a work-conserving queue; there are no old skbs
2337 		 * waiting to be sent out; and the qdisc is not running -
2338 		 * xmit the skb directly.
2339 		 */
2340 		if (!(dev->priv_flags & IFF_XMIT_DST_RELEASE))
2341 			skb_dst_force(skb);
2342 
2343 		qdisc_bstats_update(q, skb);
2344 
2345 		if (sch_direct_xmit(skb, q, dev, txq, root_lock)) {
2346 			if (unlikely(contended)) {
2347 				spin_unlock(&q->busylock);
2348 				contended = false;
2349 			}
2350 			__qdisc_run(q);
2351 		} else
2352 			qdisc_run_end(q);
2353 
2354 		rc = NET_XMIT_SUCCESS;
2355 	} else {
2356 		skb_dst_force(skb);
2357 		rc = q->enqueue(skb, q) & NET_XMIT_MASK;
2358 		if (qdisc_run_begin(q)) {
2359 			if (unlikely(contended)) {
2360 				spin_unlock(&q->busylock);
2361 				contended = false;
2362 			}
2363 			__qdisc_run(q);
2364 		}
2365 	}
2366 	spin_unlock(root_lock);
2367 	if (unlikely(contended))
2368 		spin_unlock(&q->busylock);
2369 	return rc;
2370 }
2371 
2372 static DEFINE_PER_CPU(int, xmit_recursion);
2373 #define RECURSION_LIMIT 10
2374 
2375 /**
2376  *	dev_queue_xmit - transmit a buffer
2377  *	@skb: buffer to transmit
2378  *
2379  *	Queue a buffer for transmission to a network device. The caller must
2380  *	have set the device and priority and built the buffer before calling
2381  *	this function. The function can be called from an interrupt.
2382  *
2383  *	A negative errno code is returned on a failure. A success does not
2384  *	guarantee the frame will be transmitted as it may be dropped due
2385  *	to congestion or traffic shaping.
2386  *
2387  * -----------------------------------------------------------------------------------
2388  *      I notice this method can also return errors from the queue disciplines,
2389  *      including NET_XMIT_DROP, which is a positive value.  So, errors can also
2390  *      be positive.
2391  *
2392  *      Regardless of the return value, the skb is consumed, so it is currently
2393  *      difficult to retry a send to this method.  (You can bump the ref count
2394  *      before sending to hold a reference for retry if you are careful.)
2395  *
2396  *      When calling this method, interrupts MUST be enabled.  This is because
2397  *      the BH enable code must have IRQs enabled so that it will not deadlock.
2398  *          --BLG
2399  */
dev_queue_xmit(struct sk_buff * skb)2400 int dev_queue_xmit(struct sk_buff *skb)
2401 {
2402 	struct net_device *dev = skb->dev;
2403 	struct netdev_queue *txq;
2404 	struct Qdisc *q;
2405 	int rc = -ENOMEM;
2406 
2407 	/* Disable soft irqs for various locks below. Also
2408 	 * stops preemption for RCU.
2409 	 */
2410 	rcu_read_lock_bh();
2411 
2412 	txq = dev_pick_tx(dev, skb);
2413 	q = rcu_dereference_bh(txq->qdisc);
2414 
2415 #ifdef CONFIG_NET_CLS_ACT
2416 	skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_EGRESS);
2417 #endif
2418 	trace_net_dev_queue(skb);
2419 	if (q->enqueue) {
2420 		rc = __dev_xmit_skb(skb, q, dev, txq);
2421 		goto out;
2422 	}
2423 
2424 	/* The device has no queue. Common case for software devices:
2425 	   loopback, all the sorts of tunnels...
2426 
2427 	   Really, it is unlikely that netif_tx_lock protection is necessary
2428 	   here.  (f.e. loopback and IP tunnels are clean ignoring statistics
2429 	   counters.)
2430 	   However, it is possible, that they rely on protection
2431 	   made by us here.
2432 
2433 	   Check this and shot the lock. It is not prone from deadlocks.
2434 	   Either shot noqueue qdisc, it is even simpler 8)
2435 	 */
2436 	if (dev->flags & IFF_UP) {
2437 		int cpu = smp_processor_id(); /* ok because BHs are off */
2438 
2439 		if (txq->xmit_lock_owner != cpu) {
2440 
2441 			if (__this_cpu_read(xmit_recursion) > RECURSION_LIMIT)
2442 				goto recursion_alert;
2443 
2444 			HARD_TX_LOCK(dev, txq, cpu);
2445 
2446 			if (!netif_tx_queue_stopped(txq)) {
2447 				__this_cpu_inc(xmit_recursion);
2448 				rc = dev_hard_start_xmit(skb, dev, txq);
2449 				__this_cpu_dec(xmit_recursion);
2450 				if (dev_xmit_complete(rc)) {
2451 					HARD_TX_UNLOCK(dev, txq);
2452 					goto out;
2453 				}
2454 			}
2455 			HARD_TX_UNLOCK(dev, txq);
2456 			if (net_ratelimit())
2457 				printk(KERN_CRIT "Virtual device %s asks to "
2458 				       "queue packet!\n", dev->name);
2459 		} else {
2460 			/* Recursion is detected! It is possible,
2461 			 * unfortunately
2462 			 */
2463 recursion_alert:
2464 			if (net_ratelimit())
2465 				printk(KERN_CRIT "Dead loop on virtual device "
2466 				       "%s, fix it urgently!\n", dev->name);
2467 		}
2468 	}
2469 
2470 	rc = -ENETDOWN;
2471 	rcu_read_unlock_bh();
2472 
2473 	kfree_skb(skb);
2474 	return rc;
2475 out:
2476 	rcu_read_unlock_bh();
2477 	return rc;
2478 }
2479 EXPORT_SYMBOL(dev_queue_xmit);
2480 
2481 
2482 /*=======================================================================
2483 			Receiver routines
2484   =======================================================================*/
2485 
2486 int netdev_max_backlog __read_mostly = 1000;
2487 int netdev_tstamp_prequeue __read_mostly = 1;
2488 int netdev_budget __read_mostly = 300;
2489 int weight_p __read_mostly = 64;            /* old backlog weight */
2490 
2491 /* Called with irq disabled */
____napi_schedule(struct softnet_data * sd,struct napi_struct * napi)2492 static inline void ____napi_schedule(struct softnet_data *sd,
2493 				     struct napi_struct *napi)
2494 {
2495 	list_add_tail(&napi->poll_list, &sd->poll_list);
2496 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
2497 }
2498 
2499 /*
2500  * __skb_get_rxhash: calculate a flow hash based on src/dst addresses
2501  * and src/dst port numbers. Returns a non-zero hash number on success
2502  * and 0 on failure.
2503  */
__skb_get_rxhash(struct sk_buff * skb)2504 __u32 __skb_get_rxhash(struct sk_buff *skb)
2505 {
2506 	int nhoff, hash = 0, poff;
2507 	struct ipv6hdr *ip6;
2508 	struct iphdr *ip;
2509 	u8 ip_proto;
2510 	u32 addr1, addr2, ihl;
2511 	union {
2512 		u32 v32;
2513 		u16 v16[2];
2514 	} ports;
2515 
2516 	nhoff = skb_network_offset(skb);
2517 
2518 	switch (skb->protocol) {
2519 	case __constant_htons(ETH_P_IP):
2520 		if (!pskb_may_pull(skb, sizeof(*ip) + nhoff))
2521 			goto done;
2522 
2523 		ip = (struct iphdr *) (skb->data + nhoff);
2524 		if (ip->frag_off & htons(IP_MF | IP_OFFSET))
2525 			ip_proto = 0;
2526 		else
2527 			ip_proto = ip->protocol;
2528 		addr1 = (__force u32) ip->saddr;
2529 		addr2 = (__force u32) ip->daddr;
2530 		ihl = ip->ihl;
2531 		break;
2532 	case __constant_htons(ETH_P_IPV6):
2533 		if (!pskb_may_pull(skb, sizeof(*ip6) + nhoff))
2534 			goto done;
2535 
2536 		ip6 = (struct ipv6hdr *) (skb->data + nhoff);
2537 		ip_proto = ip6->nexthdr;
2538 		addr1 = (__force u32) ip6->saddr.s6_addr32[3];
2539 		addr2 = (__force u32) ip6->daddr.s6_addr32[3];
2540 		ihl = (40 >> 2);
2541 		break;
2542 	default:
2543 		goto done;
2544 	}
2545 
2546 	ports.v32 = 0;
2547 	poff = proto_ports_offset(ip_proto);
2548 	if (poff >= 0) {
2549 		nhoff += ihl * 4 + poff;
2550 		if (pskb_may_pull(skb, nhoff + 4)) {
2551 			ports.v32 = * (__force u32 *) (skb->data + nhoff);
2552 			if (ports.v16[1] < ports.v16[0])
2553 				swap(ports.v16[0], ports.v16[1]);
2554 		}
2555 	}
2556 
2557 	/* get a consistent hash (same value on both flow directions) */
2558 	if (addr2 < addr1)
2559 		swap(addr1, addr2);
2560 
2561 	hash = jhash_3words(addr1, addr2, ports.v32, hashrnd);
2562 	if (!hash)
2563 		hash = 1;
2564 
2565 done:
2566 	return hash;
2567 }
2568 EXPORT_SYMBOL(__skb_get_rxhash);
2569 
2570 #ifdef CONFIG_RPS
2571 
2572 /* One global table that all flow-based protocols share. */
2573 struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
2574 EXPORT_SYMBOL(rps_sock_flow_table);
2575 
2576 static struct rps_dev_flow *
set_rps_cpu(struct net_device * dev,struct sk_buff * skb,struct rps_dev_flow * rflow,u16 next_cpu)2577 set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
2578 	    struct rps_dev_flow *rflow, u16 next_cpu)
2579 {
2580 	u16 tcpu;
2581 
2582 	tcpu = rflow->cpu = next_cpu;
2583 	if (tcpu != RPS_NO_CPU) {
2584 #ifdef CONFIG_RFS_ACCEL
2585 		struct netdev_rx_queue *rxqueue;
2586 		struct rps_dev_flow_table *flow_table;
2587 		struct rps_dev_flow *old_rflow;
2588 		u32 flow_id;
2589 		u16 rxq_index;
2590 		int rc;
2591 
2592 		/* Should we steer this flow to a different hardware queue? */
2593 		if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
2594 		    !(dev->features & NETIF_F_NTUPLE))
2595 			goto out;
2596 		rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
2597 		if (rxq_index == skb_get_rx_queue(skb))
2598 			goto out;
2599 
2600 		rxqueue = dev->_rx + rxq_index;
2601 		flow_table = rcu_dereference(rxqueue->rps_flow_table);
2602 		if (!flow_table)
2603 			goto out;
2604 		flow_id = skb->rxhash & flow_table->mask;
2605 		rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
2606 							rxq_index, flow_id);
2607 		if (rc < 0)
2608 			goto out;
2609 		old_rflow = rflow;
2610 		rflow = &flow_table->flows[flow_id];
2611 		rflow->cpu = next_cpu;
2612 		rflow->filter = rc;
2613 		if (old_rflow->filter == rflow->filter)
2614 			old_rflow->filter = RPS_NO_FILTER;
2615 	out:
2616 #endif
2617 		rflow->last_qtail =
2618 			per_cpu(softnet_data, tcpu).input_queue_head;
2619 	}
2620 
2621 	return rflow;
2622 }
2623 
2624 /*
2625  * get_rps_cpu is called from netif_receive_skb and returns the target
2626  * CPU from the RPS map of the receiving queue for a given skb.
2627  * rcu_read_lock must be held on entry.
2628  */
get_rps_cpu(struct net_device * dev,struct sk_buff * skb,struct rps_dev_flow ** rflowp)2629 static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
2630 		       struct rps_dev_flow **rflowp)
2631 {
2632 	struct netdev_rx_queue *rxqueue;
2633 	struct rps_map *map;
2634 	struct rps_dev_flow_table *flow_table;
2635 	struct rps_sock_flow_table *sock_flow_table;
2636 	int cpu = -1;
2637 	u16 tcpu;
2638 
2639 	if (skb_rx_queue_recorded(skb)) {
2640 		u16 index = skb_get_rx_queue(skb);
2641 		if (unlikely(index >= dev->real_num_rx_queues)) {
2642 			WARN_ONCE(dev->real_num_rx_queues > 1,
2643 				  "%s received packet on queue %u, but number "
2644 				  "of RX queues is %u\n",
2645 				  dev->name, index, dev->real_num_rx_queues);
2646 			goto done;
2647 		}
2648 		rxqueue = dev->_rx + index;
2649 	} else
2650 		rxqueue = dev->_rx;
2651 
2652 	map = rcu_dereference(rxqueue->rps_map);
2653 	if (map) {
2654 		if (map->len == 1 &&
2655 		    !rcu_dereference_raw(rxqueue->rps_flow_table)) {
2656 			tcpu = map->cpus[0];
2657 			if (cpu_online(tcpu))
2658 				cpu = tcpu;
2659 			goto done;
2660 		}
2661 	} else if (!rcu_dereference_raw(rxqueue->rps_flow_table)) {
2662 		goto done;
2663 	}
2664 
2665 	skb_reset_network_header(skb);
2666 	if (!skb_get_rxhash(skb))
2667 		goto done;
2668 
2669 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
2670 	sock_flow_table = rcu_dereference(rps_sock_flow_table);
2671 	if (flow_table && sock_flow_table) {
2672 		u16 next_cpu;
2673 		struct rps_dev_flow *rflow;
2674 
2675 		rflow = &flow_table->flows[skb->rxhash & flow_table->mask];
2676 		tcpu = rflow->cpu;
2677 
2678 		next_cpu = sock_flow_table->ents[skb->rxhash &
2679 		    sock_flow_table->mask];
2680 
2681 		/*
2682 		 * If the desired CPU (where last recvmsg was done) is
2683 		 * different from current CPU (one in the rx-queue flow
2684 		 * table entry), switch if one of the following holds:
2685 		 *   - Current CPU is unset (equal to RPS_NO_CPU).
2686 		 *   - Current CPU is offline.
2687 		 *   - The current CPU's queue tail has advanced beyond the
2688 		 *     last packet that was enqueued using this table entry.
2689 		 *     This guarantees that all previous packets for the flow
2690 		 *     have been dequeued, thus preserving in order delivery.
2691 		 */
2692 		if (unlikely(tcpu != next_cpu) &&
2693 		    (tcpu == RPS_NO_CPU || !cpu_online(tcpu) ||
2694 		     ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
2695 		      rflow->last_qtail)) >= 0))
2696 			rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
2697 
2698 		if (tcpu != RPS_NO_CPU && cpu_online(tcpu)) {
2699 			*rflowp = rflow;
2700 			cpu = tcpu;
2701 			goto done;
2702 		}
2703 	}
2704 
2705 	if (map) {
2706 		tcpu = map->cpus[((u64) skb->rxhash * map->len) >> 32];
2707 
2708 		if (cpu_online(tcpu)) {
2709 			cpu = tcpu;
2710 			goto done;
2711 		}
2712 	}
2713 
2714 done:
2715 	return cpu;
2716 }
2717 
2718 #ifdef CONFIG_RFS_ACCEL
2719 
2720 /**
2721  * rps_may_expire_flow - check whether an RFS hardware filter may be removed
2722  * @dev: Device on which the filter was set
2723  * @rxq_index: RX queue index
2724  * @flow_id: Flow ID passed to ndo_rx_flow_steer()
2725  * @filter_id: Filter ID returned by ndo_rx_flow_steer()
2726  *
2727  * Drivers that implement ndo_rx_flow_steer() should periodically call
2728  * this function for each installed filter and remove the filters for
2729  * which it returns %true.
2730  */
rps_may_expire_flow(struct net_device * dev,u16 rxq_index,u32 flow_id,u16 filter_id)2731 bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
2732 			 u32 flow_id, u16 filter_id)
2733 {
2734 	struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
2735 	struct rps_dev_flow_table *flow_table;
2736 	struct rps_dev_flow *rflow;
2737 	bool expire = true;
2738 	int cpu;
2739 
2740 	rcu_read_lock();
2741 	flow_table = rcu_dereference(rxqueue->rps_flow_table);
2742 	if (flow_table && flow_id <= flow_table->mask) {
2743 		rflow = &flow_table->flows[flow_id];
2744 		cpu = ACCESS_ONCE(rflow->cpu);
2745 		if (rflow->filter == filter_id && cpu != RPS_NO_CPU &&
2746 		    ((int)(per_cpu(softnet_data, cpu).input_queue_head -
2747 			   rflow->last_qtail) <
2748 		     (int)(10 * flow_table->mask)))
2749 			expire = false;
2750 	}
2751 	rcu_read_unlock();
2752 	return expire;
2753 }
2754 EXPORT_SYMBOL(rps_may_expire_flow);
2755 
2756 #endif /* CONFIG_RFS_ACCEL */
2757 
2758 /* Called from hardirq (IPI) context */
rps_trigger_softirq(void * data)2759 static void rps_trigger_softirq(void *data)
2760 {
2761 	struct softnet_data *sd = data;
2762 
2763 	____napi_schedule(sd, &sd->backlog);
2764 	sd->received_rps++;
2765 }
2766 
2767 #endif /* CONFIG_RPS */
2768 
2769 /*
2770  * Check if this softnet_data structure is another cpu one
2771  * If yes, queue it to our IPI list and return 1
2772  * If no, return 0
2773  */
rps_ipi_queued(struct softnet_data * sd)2774 static int rps_ipi_queued(struct softnet_data *sd)
2775 {
2776 #ifdef CONFIG_RPS
2777 	struct softnet_data *mysd = &__get_cpu_var(softnet_data);
2778 
2779 	if (sd != mysd) {
2780 		sd->rps_ipi_next = mysd->rps_ipi_list;
2781 		mysd->rps_ipi_list = sd;
2782 
2783 		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
2784 		return 1;
2785 	}
2786 #endif /* CONFIG_RPS */
2787 	return 0;
2788 }
2789 
2790 /*
2791  * enqueue_to_backlog is called to queue an skb to a per CPU backlog
2792  * queue (may be a remote CPU queue).
2793  */
enqueue_to_backlog(struct sk_buff * skb,int cpu,unsigned int * qtail)2794 static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
2795 			      unsigned int *qtail)
2796 {
2797 	struct softnet_data *sd;
2798 	unsigned long flags;
2799 
2800 	sd = &per_cpu(softnet_data, cpu);
2801 
2802 	local_irq_save(flags);
2803 
2804 	rps_lock(sd);
2805 	if (skb_queue_len(&sd->input_pkt_queue) <= netdev_max_backlog) {
2806 		if (skb_queue_len(&sd->input_pkt_queue)) {
2807 enqueue:
2808 			__skb_queue_tail(&sd->input_pkt_queue, skb);
2809 			input_queue_tail_incr_save(sd, qtail);
2810 			rps_unlock(sd);
2811 			local_irq_restore(flags);
2812 			return NET_RX_SUCCESS;
2813 		}
2814 
2815 		/* Schedule NAPI for backlog device
2816 		 * We can use non atomic operation since we own the queue lock
2817 		 */
2818 		if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state)) {
2819 			if (!rps_ipi_queued(sd))
2820 				____napi_schedule(sd, &sd->backlog);
2821 		}
2822 		goto enqueue;
2823 	}
2824 
2825 	sd->dropped++;
2826 	rps_unlock(sd);
2827 
2828 	local_irq_restore(flags);
2829 
2830 	atomic_long_inc(&skb->dev->rx_dropped);
2831 	kfree_skb(skb);
2832 	return NET_RX_DROP;
2833 }
2834 
2835 /**
2836  *	netif_rx	-	post buffer to the network code
2837  *	@skb: buffer to post
2838  *
2839  *	This function receives a packet from a device driver and queues it for
2840  *	the upper (protocol) levels to process.  It always succeeds. The buffer
2841  *	may be dropped during processing for congestion control or by the
2842  *	protocol layers.
2843  *
2844  *	return values:
2845  *	NET_RX_SUCCESS	(no congestion)
2846  *	NET_RX_DROP     (packet was dropped)
2847  *
2848  */
2849 
netif_rx(struct sk_buff * skb)2850 int netif_rx(struct sk_buff *skb)
2851 {
2852 	int ret;
2853 
2854 	/* if netpoll wants it, pretend we never saw it */
2855 	if (netpoll_rx(skb))
2856 		return NET_RX_DROP;
2857 
2858 	if (netdev_tstamp_prequeue)
2859 		net_timestamp_check(skb);
2860 
2861 	trace_netif_rx(skb);
2862 #ifdef CONFIG_RPS
2863 	{
2864 		struct rps_dev_flow voidflow, *rflow = &voidflow;
2865 		int cpu;
2866 
2867 		preempt_disable();
2868 		rcu_read_lock();
2869 
2870 		cpu = get_rps_cpu(skb->dev, skb, &rflow);
2871 		if (cpu < 0)
2872 			cpu = smp_processor_id();
2873 
2874 		ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
2875 
2876 		rcu_read_unlock();
2877 		preempt_enable();
2878 	}
2879 #else
2880 	{
2881 		unsigned int qtail;
2882 		ret = enqueue_to_backlog(skb, get_cpu(), &qtail);
2883 		put_cpu();
2884 	}
2885 #endif
2886 	return ret;
2887 }
2888 EXPORT_SYMBOL(netif_rx);
2889 
netif_rx_ni(struct sk_buff * skb)2890 int netif_rx_ni(struct sk_buff *skb)
2891 {
2892 	int err;
2893 
2894 	preempt_disable();
2895 	err = netif_rx(skb);
2896 	if (local_softirq_pending())
2897 		do_softirq();
2898 	preempt_enable();
2899 
2900 	return err;
2901 }
2902 EXPORT_SYMBOL(netif_rx_ni);
2903 
net_tx_action(struct softirq_action * h)2904 static void net_tx_action(struct softirq_action *h)
2905 {
2906 	struct softnet_data *sd = &__get_cpu_var(softnet_data);
2907 
2908 	if (sd->completion_queue) {
2909 		struct sk_buff *clist;
2910 
2911 		local_irq_disable();
2912 		clist = sd->completion_queue;
2913 		sd->completion_queue = NULL;
2914 		local_irq_enable();
2915 
2916 		while (clist) {
2917 			struct sk_buff *skb = clist;
2918 			clist = clist->next;
2919 
2920 			WARN_ON(atomic_read(&skb->users));
2921 			trace_kfree_skb(skb, net_tx_action);
2922 			__kfree_skb(skb);
2923 		}
2924 	}
2925 
2926 	if (sd->output_queue) {
2927 		struct Qdisc *head;
2928 
2929 		local_irq_disable();
2930 		head = sd->output_queue;
2931 		sd->output_queue = NULL;
2932 		sd->output_queue_tailp = &sd->output_queue;
2933 		local_irq_enable();
2934 
2935 		while (head) {
2936 			struct Qdisc *q = head;
2937 			spinlock_t *root_lock;
2938 
2939 			head = head->next_sched;
2940 
2941 			root_lock = qdisc_lock(q);
2942 			if (spin_trylock(root_lock)) {
2943 				smp_mb__before_clear_bit();
2944 				clear_bit(__QDISC_STATE_SCHED,
2945 					  &q->state);
2946 				qdisc_run(q);
2947 				spin_unlock(root_lock);
2948 			} else {
2949 				if (!test_bit(__QDISC_STATE_DEACTIVATED,
2950 					      &q->state)) {
2951 					__netif_reschedule(q);
2952 				} else {
2953 					smp_mb__before_clear_bit();
2954 					clear_bit(__QDISC_STATE_SCHED,
2955 						  &q->state);
2956 				}
2957 			}
2958 		}
2959 	}
2960 }
2961 
2962 #if (defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)) && \
2963     (defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE))
2964 /* This hook is defined here for ATM LANE */
2965 int (*br_fdb_test_addr_hook)(struct net_device *dev,
2966 			     unsigned char *addr) __read_mostly;
2967 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
2968 #endif
2969 
2970 #ifdef CONFIG_NET_CLS_ACT
2971 /* TODO: Maybe we should just force sch_ingress to be compiled in
2972  * when CONFIG_NET_CLS_ACT is? otherwise some useless instructions
2973  * a compare and 2 stores extra right now if we dont have it on
2974  * but have CONFIG_NET_CLS_ACT
2975  * NOTE: This doesn't stop any functionality; if you dont have
2976  * the ingress scheduler, you just can't add policies on ingress.
2977  *
2978  */
ing_filter(struct sk_buff * skb,struct netdev_queue * rxq)2979 static int ing_filter(struct sk_buff *skb, struct netdev_queue *rxq)
2980 {
2981 	struct net_device *dev = skb->dev;
2982 	u32 ttl = G_TC_RTTL(skb->tc_verd);
2983 	int result = TC_ACT_OK;
2984 	struct Qdisc *q;
2985 
2986 	if (unlikely(MAX_RED_LOOP < ttl++)) {
2987 		if (net_ratelimit())
2988 			pr_warning( "Redir loop detected Dropping packet (%d->%d)\n",
2989 			       skb->skb_iif, dev->ifindex);
2990 		return TC_ACT_SHOT;
2991 	}
2992 
2993 	skb->tc_verd = SET_TC_RTTL(skb->tc_verd, ttl);
2994 	skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_INGRESS);
2995 
2996 	q = rxq->qdisc;
2997 	if (q != &noop_qdisc) {
2998 		spin_lock(qdisc_lock(q));
2999 		if (likely(!test_bit(__QDISC_STATE_DEACTIVATED, &q->state)))
3000 			result = qdisc_enqueue_root(skb, q);
3001 		spin_unlock(qdisc_lock(q));
3002 	}
3003 
3004 	return result;
3005 }
3006 
handle_ing(struct sk_buff * skb,struct packet_type ** pt_prev,int * ret,struct net_device * orig_dev)3007 static inline struct sk_buff *handle_ing(struct sk_buff *skb,
3008 					 struct packet_type **pt_prev,
3009 					 int *ret, struct net_device *orig_dev)
3010 {
3011 	struct netdev_queue *rxq = rcu_dereference(skb->dev->ingress_queue);
3012 
3013 	if (!rxq || rxq->qdisc == &noop_qdisc)
3014 		goto out;
3015 
3016 	if (*pt_prev) {
3017 		*ret = deliver_skb(skb, *pt_prev, orig_dev);
3018 		*pt_prev = NULL;
3019 	}
3020 
3021 	switch (ing_filter(skb, rxq)) {
3022 	case TC_ACT_SHOT:
3023 	case TC_ACT_STOLEN:
3024 		kfree_skb(skb);
3025 		return NULL;
3026 	}
3027 
3028 out:
3029 	skb->tc_verd = 0;
3030 	return skb;
3031 }
3032 #endif
3033 
3034 /**
3035  *	netdev_rx_handler_register - register receive handler
3036  *	@dev: device to register a handler for
3037  *	@rx_handler: receive handler to register
3038  *	@rx_handler_data: data pointer that is used by rx handler
3039  *
3040  *	Register a receive hander for a device. This handler will then be
3041  *	called from __netif_receive_skb. A negative errno code is returned
3042  *	on a failure.
3043  *
3044  *	The caller must hold the rtnl_mutex.
3045  *
3046  *	For a general description of rx_handler, see enum rx_handler_result.
3047  */
netdev_rx_handler_register(struct net_device * dev,rx_handler_func_t * rx_handler,void * rx_handler_data)3048 int netdev_rx_handler_register(struct net_device *dev,
3049 			       rx_handler_func_t *rx_handler,
3050 			       void *rx_handler_data)
3051 {
3052 	ASSERT_RTNL();
3053 
3054 	if (dev->rx_handler)
3055 		return -EBUSY;
3056 
3057 	rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
3058 	rcu_assign_pointer(dev->rx_handler, rx_handler);
3059 
3060 	return 0;
3061 }
3062 EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
3063 
3064 /**
3065  *	netdev_rx_handler_unregister - unregister receive handler
3066  *	@dev: device to unregister a handler from
3067  *
3068  *	Unregister a receive hander from a device.
3069  *
3070  *	The caller must hold the rtnl_mutex.
3071  */
netdev_rx_handler_unregister(struct net_device * dev)3072 void netdev_rx_handler_unregister(struct net_device *dev)
3073 {
3074 
3075 	ASSERT_RTNL();
3076 	rcu_assign_pointer(dev->rx_handler, NULL);
3077 	rcu_assign_pointer(dev->rx_handler_data, NULL);
3078 }
3079 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
3080 
vlan_on_bond_hook(struct sk_buff * skb)3081 static void vlan_on_bond_hook(struct sk_buff *skb)
3082 {
3083 	/*
3084 	 * Make sure ARP frames received on VLAN interfaces stacked on
3085 	 * bonding interfaces still make their way to any base bonding
3086 	 * device that may have registered for a specific ptype.
3087 	 */
3088 	if (skb->dev->priv_flags & IFF_802_1Q_VLAN &&
3089 	    vlan_dev_real_dev(skb->dev)->priv_flags & IFF_BONDING &&
3090 	    skb->protocol == htons(ETH_P_ARP)) {
3091 		struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
3092 
3093 		if (!skb2)
3094 			return;
3095 		skb2->dev = vlan_dev_real_dev(skb->dev);
3096 		netif_rx(skb2);
3097 	}
3098 }
3099 
__netif_receive_skb(struct sk_buff * skb)3100 static int __netif_receive_skb(struct sk_buff *skb)
3101 {
3102 	struct packet_type *ptype, *pt_prev;
3103 	rx_handler_func_t *rx_handler;
3104 	struct net_device *orig_dev;
3105 	struct net_device *null_or_dev;
3106 	bool deliver_exact = false;
3107 	int ret = NET_RX_DROP;
3108 	__be16 type;
3109 
3110 	if (!netdev_tstamp_prequeue)
3111 		net_timestamp_check(skb);
3112 
3113 	trace_netif_receive_skb(skb);
3114 
3115 	/* if we've gotten here through NAPI, check netpoll */
3116 	if (netpoll_receive_skb(skb))
3117 		return NET_RX_DROP;
3118 
3119 	if (!skb->skb_iif)
3120 		skb->skb_iif = skb->dev->ifindex;
3121 	orig_dev = skb->dev;
3122 
3123 	skb_reset_network_header(skb);
3124 	skb_reset_transport_header(skb);
3125 	skb->mac_len = skb->network_header - skb->mac_header;
3126 
3127 	pt_prev = NULL;
3128 
3129 	rcu_read_lock();
3130 
3131 another_round:
3132 
3133 	__this_cpu_inc(softnet_data.processed);
3134 
3135 #ifdef CONFIG_NET_CLS_ACT
3136 	if (skb->tc_verd & TC_NCLS) {
3137 		skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
3138 		goto ncls;
3139 	}
3140 #endif
3141 
3142 	list_for_each_entry_rcu(ptype, &ptype_all, list) {
3143 		if (!ptype->dev || ptype->dev == skb->dev) {
3144 			if (pt_prev)
3145 				ret = deliver_skb(skb, pt_prev, orig_dev);
3146 			pt_prev = ptype;
3147 		}
3148 	}
3149 
3150 #ifdef CONFIG_NET_CLS_ACT
3151 	skb = handle_ing(skb, &pt_prev, &ret, orig_dev);
3152 	if (!skb)
3153 		goto out;
3154 ncls:
3155 #endif
3156 
3157 	rx_handler = rcu_dereference(skb->dev->rx_handler);
3158 	if (rx_handler) {
3159 		if (pt_prev) {
3160 			ret = deliver_skb(skb, pt_prev, orig_dev);
3161 			pt_prev = NULL;
3162 		}
3163 		switch (rx_handler(&skb)) {
3164 		case RX_HANDLER_CONSUMED:
3165 			goto out;
3166 		case RX_HANDLER_ANOTHER:
3167 			goto another_round;
3168 		case RX_HANDLER_EXACT:
3169 			deliver_exact = true;
3170 		case RX_HANDLER_PASS:
3171 			break;
3172 		default:
3173 			BUG();
3174 		}
3175 	}
3176 
3177 	if (vlan_tx_tag_present(skb)) {
3178 		if (pt_prev) {
3179 			ret = deliver_skb(skb, pt_prev, orig_dev);
3180 			pt_prev = NULL;
3181 		}
3182 		if (vlan_hwaccel_do_receive(&skb)) {
3183 			ret = __netif_receive_skb(skb);
3184 			goto out;
3185 		} else if (unlikely(!skb))
3186 			goto out;
3187 	}
3188 
3189 	vlan_on_bond_hook(skb);
3190 
3191 	/* deliver only exact match when indicated */
3192 	null_or_dev = deliver_exact ? skb->dev : NULL;
3193 
3194 	type = skb->protocol;
3195 	list_for_each_entry_rcu(ptype,
3196 			&ptype_base[ntohs(type) & PTYPE_HASH_MASK], list) {
3197 		if (ptype->type == type &&
3198 		    (ptype->dev == null_or_dev || ptype->dev == skb->dev ||
3199 		     ptype->dev == orig_dev)) {
3200 			if (pt_prev)
3201 				ret = deliver_skb(skb, pt_prev, orig_dev);
3202 			pt_prev = ptype;
3203 		}
3204 	}
3205 
3206 	if (pt_prev) {
3207 		ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
3208 	} else {
3209 		atomic_long_inc(&skb->dev->rx_dropped);
3210 		kfree_skb(skb);
3211 		/* Jamal, now you will not able to escape explaining
3212 		 * me how you were going to use this. :-)
3213 		 */
3214 		ret = NET_RX_DROP;
3215 	}
3216 
3217 out:
3218 	rcu_read_unlock();
3219 	return ret;
3220 }
3221 
3222 /**
3223  *	netif_receive_skb - process receive buffer from network
3224  *	@skb: buffer to process
3225  *
3226  *	netif_receive_skb() is the main receive data processing function.
3227  *	It always succeeds. The buffer may be dropped during processing
3228  *	for congestion control or by the protocol layers.
3229  *
3230  *	This function may only be called from softirq context and interrupts
3231  *	should be enabled.
3232  *
3233  *	Return values (usually ignored):
3234  *	NET_RX_SUCCESS: no congestion
3235  *	NET_RX_DROP: packet was dropped
3236  */
netif_receive_skb(struct sk_buff * skb)3237 int netif_receive_skb(struct sk_buff *skb)
3238 {
3239 	if (netdev_tstamp_prequeue)
3240 		net_timestamp_check(skb);
3241 
3242 	if (skb_defer_rx_timestamp(skb))
3243 		return NET_RX_SUCCESS;
3244 
3245 #ifdef CONFIG_RPS
3246 	{
3247 		struct rps_dev_flow voidflow, *rflow = &voidflow;
3248 		int cpu, ret;
3249 
3250 		rcu_read_lock();
3251 
3252 		cpu = get_rps_cpu(skb->dev, skb, &rflow);
3253 
3254 		if (cpu >= 0) {
3255 			ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
3256 			rcu_read_unlock();
3257 		} else {
3258 			rcu_read_unlock();
3259 			ret = __netif_receive_skb(skb);
3260 		}
3261 
3262 		return ret;
3263 	}
3264 #else
3265 	return __netif_receive_skb(skb);
3266 #endif
3267 }
3268 EXPORT_SYMBOL(netif_receive_skb);
3269 
3270 /* Network device is going away, flush any packets still pending
3271  * Called with irqs disabled.
3272  */
flush_backlog(void * arg)3273 static void flush_backlog(void *arg)
3274 {
3275 	struct net_device *dev = arg;
3276 	struct softnet_data *sd = &__get_cpu_var(softnet_data);
3277 	struct sk_buff *skb, *tmp;
3278 
3279 	rps_lock(sd);
3280 	skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
3281 		if (skb->dev == dev) {
3282 			__skb_unlink(skb, &sd->input_pkt_queue);
3283 			kfree_skb(skb);
3284 			input_queue_head_incr(sd);
3285 		}
3286 	}
3287 	rps_unlock(sd);
3288 
3289 	skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
3290 		if (skb->dev == dev) {
3291 			__skb_unlink(skb, &sd->process_queue);
3292 			kfree_skb(skb);
3293 			input_queue_head_incr(sd);
3294 		}
3295 	}
3296 }
3297 
napi_gro_complete(struct sk_buff * skb)3298 static int napi_gro_complete(struct sk_buff *skb)
3299 {
3300 	struct packet_type *ptype;
3301 	__be16 type = skb->protocol;
3302 	struct list_head *head = &ptype_base[ntohs(type) & PTYPE_HASH_MASK];
3303 	int err = -ENOENT;
3304 
3305 	if (NAPI_GRO_CB(skb)->count == 1) {
3306 		skb_shinfo(skb)->gso_size = 0;
3307 		goto out;
3308 	}
3309 
3310 	rcu_read_lock();
3311 	list_for_each_entry_rcu(ptype, head, list) {
3312 		if (ptype->type != type || ptype->dev || !ptype->gro_complete)
3313 			continue;
3314 
3315 		err = ptype->gro_complete(skb);
3316 		break;
3317 	}
3318 	rcu_read_unlock();
3319 
3320 	if (err) {
3321 		WARN_ON(&ptype->list == head);
3322 		kfree_skb(skb);
3323 		return NET_RX_SUCCESS;
3324 	}
3325 
3326 out:
3327 	return netif_receive_skb(skb);
3328 }
3329 
napi_gro_flush(struct napi_struct * napi)3330 inline void napi_gro_flush(struct napi_struct *napi)
3331 {
3332 	struct sk_buff *skb, *next;
3333 
3334 	for (skb = napi->gro_list; skb; skb = next) {
3335 		next = skb->next;
3336 		skb->next = NULL;
3337 		napi_gro_complete(skb);
3338 	}
3339 
3340 	napi->gro_count = 0;
3341 	napi->gro_list = NULL;
3342 }
3343 EXPORT_SYMBOL(napi_gro_flush);
3344 
dev_gro_receive(struct napi_struct * napi,struct sk_buff * skb)3345 enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3346 {
3347 	struct sk_buff **pp = NULL;
3348 	struct packet_type *ptype;
3349 	__be16 type = skb->protocol;
3350 	struct list_head *head = &ptype_base[ntohs(type) & PTYPE_HASH_MASK];
3351 	int same_flow;
3352 	int mac_len;
3353 	enum gro_result ret;
3354 
3355 	if (!(skb->dev->features & NETIF_F_GRO) || netpoll_rx_on(skb))
3356 		goto normal;
3357 
3358 	if (skb_is_gso(skb) || skb_has_frag_list(skb))
3359 		goto normal;
3360 
3361 	rcu_read_lock();
3362 	list_for_each_entry_rcu(ptype, head, list) {
3363 		if (ptype->type != type || ptype->dev || !ptype->gro_receive)
3364 			continue;
3365 
3366 		skb_set_network_header(skb, skb_gro_offset(skb));
3367 		mac_len = skb->network_header - skb->mac_header;
3368 		skb->mac_len = mac_len;
3369 		NAPI_GRO_CB(skb)->same_flow = 0;
3370 		NAPI_GRO_CB(skb)->flush = 0;
3371 		NAPI_GRO_CB(skb)->free = 0;
3372 
3373 		pp = ptype->gro_receive(&napi->gro_list, skb);
3374 		break;
3375 	}
3376 	rcu_read_unlock();
3377 
3378 	if (&ptype->list == head)
3379 		goto normal;
3380 
3381 	same_flow = NAPI_GRO_CB(skb)->same_flow;
3382 	ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED;
3383 
3384 	if (pp) {
3385 		struct sk_buff *nskb = *pp;
3386 
3387 		*pp = nskb->next;
3388 		nskb->next = NULL;
3389 		napi_gro_complete(nskb);
3390 		napi->gro_count--;
3391 	}
3392 
3393 	if (same_flow)
3394 		goto ok;
3395 
3396 	if (NAPI_GRO_CB(skb)->flush || napi->gro_count >= MAX_GRO_SKBS)
3397 		goto normal;
3398 
3399 	napi->gro_count++;
3400 	NAPI_GRO_CB(skb)->count = 1;
3401 	skb_shinfo(skb)->gso_size = skb_gro_len(skb);
3402 	skb->next = napi->gro_list;
3403 	napi->gro_list = skb;
3404 	ret = GRO_HELD;
3405 
3406 pull:
3407 	if (skb_headlen(skb) < skb_gro_offset(skb)) {
3408 		int grow = skb_gro_offset(skb) - skb_headlen(skb);
3409 
3410 		BUG_ON(skb->end - skb->tail < grow);
3411 
3412 		memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow);
3413 
3414 		skb->tail += grow;
3415 		skb->data_len -= grow;
3416 
3417 		skb_shinfo(skb)->frags[0].page_offset += grow;
3418 		skb_shinfo(skb)->frags[0].size -= grow;
3419 
3420 		if (unlikely(!skb_shinfo(skb)->frags[0].size)) {
3421 			put_page(skb_shinfo(skb)->frags[0].page);
3422 			memmove(skb_shinfo(skb)->frags,
3423 				skb_shinfo(skb)->frags + 1,
3424 				--skb_shinfo(skb)->nr_frags * sizeof(skb_frag_t));
3425 		}
3426 	}
3427 
3428 ok:
3429 	return ret;
3430 
3431 normal:
3432 	ret = GRO_NORMAL;
3433 	goto pull;
3434 }
3435 EXPORT_SYMBOL(dev_gro_receive);
3436 
3437 static inline gro_result_t
__napi_gro_receive(struct napi_struct * napi,struct sk_buff * skb)3438 __napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3439 {
3440 	struct sk_buff *p;
3441 
3442 	for (p = napi->gro_list; p; p = p->next) {
3443 		unsigned long diffs;
3444 
3445 		diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev;
3446 		diffs |= p->vlan_tci ^ skb->vlan_tci;
3447 		diffs |= compare_ether_header(skb_mac_header(p),
3448 					      skb_gro_mac_header(skb));
3449 		NAPI_GRO_CB(p)->same_flow = !diffs;
3450 		NAPI_GRO_CB(p)->flush = 0;
3451 	}
3452 
3453 	return dev_gro_receive(napi, skb);
3454 }
3455 
napi_skb_finish(gro_result_t ret,struct sk_buff * skb)3456 gro_result_t napi_skb_finish(gro_result_t ret, struct sk_buff *skb)
3457 {
3458 	switch (ret) {
3459 	case GRO_NORMAL:
3460 		if (netif_receive_skb(skb))
3461 			ret = GRO_DROP;
3462 		break;
3463 
3464 	case GRO_DROP:
3465 	case GRO_MERGED_FREE:
3466 		kfree_skb(skb);
3467 		break;
3468 
3469 	case GRO_HELD:
3470 	case GRO_MERGED:
3471 		break;
3472 	}
3473 
3474 	return ret;
3475 }
3476 EXPORT_SYMBOL(napi_skb_finish);
3477 
skb_gro_reset_offset(struct sk_buff * skb)3478 void skb_gro_reset_offset(struct sk_buff *skb)
3479 {
3480 	NAPI_GRO_CB(skb)->data_offset = 0;
3481 	NAPI_GRO_CB(skb)->frag0 = NULL;
3482 	NAPI_GRO_CB(skb)->frag0_len = 0;
3483 
3484 	if (skb->mac_header == skb->tail &&
3485 	    !PageHighMem(skb_shinfo(skb)->frags[0].page)) {
3486 		NAPI_GRO_CB(skb)->frag0 =
3487 			page_address(skb_shinfo(skb)->frags[0].page) +
3488 			skb_shinfo(skb)->frags[0].page_offset;
3489 		NAPI_GRO_CB(skb)->frag0_len = skb_shinfo(skb)->frags[0].size;
3490 	}
3491 }
3492 EXPORT_SYMBOL(skb_gro_reset_offset);
3493 
napi_gro_receive(struct napi_struct * napi,struct sk_buff * skb)3494 gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3495 {
3496 	skb_gro_reset_offset(skb);
3497 
3498 	return napi_skb_finish(__napi_gro_receive(napi, skb), skb);
3499 }
3500 EXPORT_SYMBOL(napi_gro_receive);
3501 
napi_reuse_skb(struct napi_struct * napi,struct sk_buff * skb)3502 static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
3503 {
3504 	__skb_pull(skb, skb_headlen(skb));
3505 	skb_reserve(skb, NET_IP_ALIGN - skb_headroom(skb));
3506 	skb->vlan_tci = 0;
3507 	skb->dev = napi->dev;
3508 	skb->skb_iif = 0;
3509 
3510 	napi->skb = skb;
3511 }
3512 
napi_get_frags(struct napi_struct * napi)3513 struct sk_buff *napi_get_frags(struct napi_struct *napi)
3514 {
3515 	struct sk_buff *skb = napi->skb;
3516 
3517 	if (!skb) {
3518 		skb = netdev_alloc_skb_ip_align(napi->dev, GRO_MAX_HEAD);
3519 		if (skb)
3520 			napi->skb = skb;
3521 	}
3522 	return skb;
3523 }
3524 EXPORT_SYMBOL(napi_get_frags);
3525 
napi_frags_finish(struct napi_struct * napi,struct sk_buff * skb,gro_result_t ret)3526 gro_result_t napi_frags_finish(struct napi_struct *napi, struct sk_buff *skb,
3527 			       gro_result_t ret)
3528 {
3529 	switch (ret) {
3530 	case GRO_NORMAL:
3531 	case GRO_HELD:
3532 		skb->protocol = eth_type_trans(skb, skb->dev);
3533 
3534 		if (ret == GRO_HELD)
3535 			skb_gro_pull(skb, -ETH_HLEN);
3536 		else if (netif_receive_skb(skb))
3537 			ret = GRO_DROP;
3538 		break;
3539 
3540 	case GRO_DROP:
3541 	case GRO_MERGED_FREE:
3542 		napi_reuse_skb(napi, skb);
3543 		break;
3544 
3545 	case GRO_MERGED:
3546 		break;
3547 	}
3548 
3549 	return ret;
3550 }
3551 EXPORT_SYMBOL(napi_frags_finish);
3552 
napi_frags_skb(struct napi_struct * napi)3553 struct sk_buff *napi_frags_skb(struct napi_struct *napi)
3554 {
3555 	struct sk_buff *skb = napi->skb;
3556 	struct ethhdr *eth;
3557 	unsigned int hlen;
3558 	unsigned int off;
3559 
3560 	napi->skb = NULL;
3561 
3562 	skb_reset_mac_header(skb);
3563 	skb_gro_reset_offset(skb);
3564 
3565 	off = skb_gro_offset(skb);
3566 	hlen = off + sizeof(*eth);
3567 	eth = skb_gro_header_fast(skb, off);
3568 	if (skb_gro_header_hard(skb, hlen)) {
3569 		eth = skb_gro_header_slow(skb, hlen, off);
3570 		if (unlikely(!eth)) {
3571 			napi_reuse_skb(napi, skb);
3572 			skb = NULL;
3573 			goto out;
3574 		}
3575 	}
3576 
3577 	skb_gro_pull(skb, sizeof(*eth));
3578 
3579 	/*
3580 	 * This works because the only protocols we care about don't require
3581 	 * special handling.  We'll fix it up properly at the end.
3582 	 */
3583 	skb->protocol = eth->h_proto;
3584 
3585 out:
3586 	return skb;
3587 }
3588 EXPORT_SYMBOL(napi_frags_skb);
3589 
napi_gro_frags(struct napi_struct * napi)3590 gro_result_t napi_gro_frags(struct napi_struct *napi)
3591 {
3592 	struct sk_buff *skb = napi_frags_skb(napi);
3593 
3594 	if (!skb)
3595 		return GRO_DROP;
3596 
3597 	return napi_frags_finish(napi, skb, __napi_gro_receive(napi, skb));
3598 }
3599 EXPORT_SYMBOL(napi_gro_frags);
3600 
3601 /*
3602  * net_rps_action sends any pending IPI's for rps.
3603  * Note: called with local irq disabled, but exits with local irq enabled.
3604  */
net_rps_action_and_irq_enable(struct softnet_data * sd)3605 static void net_rps_action_and_irq_enable(struct softnet_data *sd)
3606 {
3607 #ifdef CONFIG_RPS
3608 	struct softnet_data *remsd = sd->rps_ipi_list;
3609 
3610 	if (remsd) {
3611 		sd->rps_ipi_list = NULL;
3612 
3613 		local_irq_enable();
3614 
3615 		/* Send pending IPI's to kick RPS processing on remote cpus. */
3616 		while (remsd) {
3617 			struct softnet_data *next = remsd->rps_ipi_next;
3618 
3619 			if (cpu_online(remsd->cpu))
3620 				__smp_call_function_single(remsd->cpu,
3621 							   &remsd->csd, 0);
3622 			remsd = next;
3623 		}
3624 	} else
3625 #endif
3626 		local_irq_enable();
3627 }
3628 
process_backlog(struct napi_struct * napi,int quota)3629 static int process_backlog(struct napi_struct *napi, int quota)
3630 {
3631 	int work = 0;
3632 	struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
3633 
3634 #ifdef CONFIG_RPS
3635 	/* Check if we have pending ipi, its better to send them now,
3636 	 * not waiting net_rx_action() end.
3637 	 */
3638 	if (sd->rps_ipi_list) {
3639 		local_irq_disable();
3640 		net_rps_action_and_irq_enable(sd);
3641 	}
3642 #endif
3643 	napi->weight = weight_p;
3644 	local_irq_disable();
3645 	while (work < quota) {
3646 		struct sk_buff *skb;
3647 		unsigned int qlen;
3648 
3649 		while ((skb = __skb_dequeue(&sd->process_queue))) {
3650 			local_irq_enable();
3651 			__netif_receive_skb(skb);
3652 			local_irq_disable();
3653 			input_queue_head_incr(sd);
3654 			if (++work >= quota) {
3655 				local_irq_enable();
3656 				return work;
3657 			}
3658 		}
3659 
3660 		rps_lock(sd);
3661 		qlen = skb_queue_len(&sd->input_pkt_queue);
3662 		if (qlen)
3663 			skb_queue_splice_tail_init(&sd->input_pkt_queue,
3664 						   &sd->process_queue);
3665 
3666 		if (qlen < quota - work) {
3667 			/*
3668 			 * Inline a custom version of __napi_complete().
3669 			 * only current cpu owns and manipulates this napi,
3670 			 * and NAPI_STATE_SCHED is the only possible flag set on backlog.
3671 			 * we can use a plain write instead of clear_bit(),
3672 			 * and we dont need an smp_mb() memory barrier.
3673 			 */
3674 			list_del(&napi->poll_list);
3675 			napi->state = 0;
3676 
3677 			quota = work + qlen;
3678 		}
3679 		rps_unlock(sd);
3680 	}
3681 	local_irq_enable();
3682 
3683 	return work;
3684 }
3685 
3686 /**
3687  * __napi_schedule - schedule for receive
3688  * @n: entry to schedule
3689  *
3690  * The entry's receive function will be scheduled to run
3691  */
__napi_schedule(struct napi_struct * n)3692 void __napi_schedule(struct napi_struct *n)
3693 {
3694 	unsigned long flags;
3695 
3696 	local_irq_save(flags);
3697 	____napi_schedule(&__get_cpu_var(softnet_data), n);
3698 	local_irq_restore(flags);
3699 }
3700 EXPORT_SYMBOL(__napi_schedule);
3701 
__napi_complete(struct napi_struct * n)3702 void __napi_complete(struct napi_struct *n)
3703 {
3704 	BUG_ON(!test_bit(NAPI_STATE_SCHED, &n->state));
3705 	BUG_ON(n->gro_list);
3706 
3707 	list_del(&n->poll_list);
3708 	smp_mb__before_clear_bit();
3709 	clear_bit(NAPI_STATE_SCHED, &n->state);
3710 }
3711 EXPORT_SYMBOL(__napi_complete);
3712 
napi_complete(struct napi_struct * n)3713 void napi_complete(struct napi_struct *n)
3714 {
3715 	unsigned long flags;
3716 
3717 	/*
3718 	 * don't let napi dequeue from the cpu poll list
3719 	 * just in case its running on a different cpu
3720 	 */
3721 	if (unlikely(test_bit(NAPI_STATE_NPSVC, &n->state)))
3722 		return;
3723 
3724 	napi_gro_flush(n);
3725 	local_irq_save(flags);
3726 	__napi_complete(n);
3727 	local_irq_restore(flags);
3728 }
3729 EXPORT_SYMBOL(napi_complete);
3730 
netif_napi_add(struct net_device * dev,struct napi_struct * napi,int (* poll)(struct napi_struct *,int),int weight)3731 void netif_napi_add(struct net_device *dev, struct napi_struct *napi,
3732 		    int (*poll)(struct napi_struct *, int), int weight)
3733 {
3734 	INIT_LIST_HEAD(&napi->poll_list);
3735 	napi->gro_count = 0;
3736 	napi->gro_list = NULL;
3737 	napi->skb = NULL;
3738 	napi->poll = poll;
3739 	napi->weight = weight;
3740 	list_add(&napi->dev_list, &dev->napi_list);
3741 	napi->dev = dev;
3742 #ifdef CONFIG_NETPOLL
3743 	spin_lock_init(&napi->poll_lock);
3744 	napi->poll_owner = -1;
3745 #endif
3746 	set_bit(NAPI_STATE_SCHED, &napi->state);
3747 }
3748 EXPORT_SYMBOL(netif_napi_add);
3749 
netif_napi_del(struct napi_struct * napi)3750 void netif_napi_del(struct napi_struct *napi)
3751 {
3752 	struct sk_buff *skb, *next;
3753 
3754 	list_del_init(&napi->dev_list);
3755 	napi_free_frags(napi);
3756 
3757 	for (skb = napi->gro_list; skb; skb = next) {
3758 		next = skb->next;
3759 		skb->next = NULL;
3760 		kfree_skb(skb);
3761 	}
3762 
3763 	napi->gro_list = NULL;
3764 	napi->gro_count = 0;
3765 }
3766 EXPORT_SYMBOL(netif_napi_del);
3767 
net_rx_action(struct softirq_action * h)3768 static void net_rx_action(struct softirq_action *h)
3769 {
3770 	struct softnet_data *sd = &__get_cpu_var(softnet_data);
3771 	unsigned long time_limit = jiffies + 2;
3772 	int budget = netdev_budget;
3773 	void *have;
3774 
3775 	local_irq_disable();
3776 
3777 	while (!list_empty(&sd->poll_list)) {
3778 		struct napi_struct *n;
3779 		int work, weight;
3780 
3781 		/* If softirq window is exhuasted then punt.
3782 		 * Allow this to run for 2 jiffies since which will allow
3783 		 * an average latency of 1.5/HZ.
3784 		 */
3785 		if (unlikely(budget <= 0 || time_after(jiffies, time_limit)))
3786 			goto softnet_break;
3787 
3788 		local_irq_enable();
3789 
3790 		/* Even though interrupts have been re-enabled, this
3791 		 * access is safe because interrupts can only add new
3792 		 * entries to the tail of this list, and only ->poll()
3793 		 * calls can remove this head entry from the list.
3794 		 */
3795 		n = list_first_entry(&sd->poll_list, struct napi_struct, poll_list);
3796 
3797 		have = netpoll_poll_lock(n);
3798 
3799 		weight = n->weight;
3800 
3801 		/* This NAPI_STATE_SCHED test is for avoiding a race
3802 		 * with netpoll's poll_napi().  Only the entity which
3803 		 * obtains the lock and sees NAPI_STATE_SCHED set will
3804 		 * actually make the ->poll() call.  Therefore we avoid
3805 		 * accidentally calling ->poll() when NAPI is not scheduled.
3806 		 */
3807 		work = 0;
3808 		if (test_bit(NAPI_STATE_SCHED, &n->state)) {
3809 			work = n->poll(n, weight);
3810 			trace_napi_poll(n);
3811 		}
3812 
3813 		WARN_ON_ONCE(work > weight);
3814 
3815 		budget -= work;
3816 
3817 		local_irq_disable();
3818 
3819 		/* Drivers must not modify the NAPI state if they
3820 		 * consume the entire weight.  In such cases this code
3821 		 * still "owns" the NAPI instance and therefore can
3822 		 * move the instance around on the list at-will.
3823 		 */
3824 		if (unlikely(work == weight)) {
3825 			if (unlikely(napi_disable_pending(n))) {
3826 				local_irq_enable();
3827 				napi_complete(n);
3828 				local_irq_disable();
3829 			} else
3830 				list_move_tail(&n->poll_list, &sd->poll_list);
3831 		}
3832 
3833 		netpoll_poll_unlock(have);
3834 	}
3835 out:
3836 	net_rps_action_and_irq_enable(sd);
3837 
3838 #ifdef CONFIG_NET_DMA
3839 	/*
3840 	 * There may not be any more sk_buffs coming right now, so push
3841 	 * any pending DMA copies to hardware
3842 	 */
3843 	dma_issue_pending_all();
3844 #endif
3845 
3846 	return;
3847 
3848 softnet_break:
3849 	sd->time_squeeze++;
3850 	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
3851 	goto out;
3852 }
3853 
3854 static gifconf_func_t *gifconf_list[NPROTO];
3855 
3856 /**
3857  *	register_gifconf	-	register a SIOCGIF handler
3858  *	@family: Address family
3859  *	@gifconf: Function handler
3860  *
3861  *	Register protocol dependent address dumping routines. The handler
3862  *	that is passed must not be freed or reused until it has been replaced
3863  *	by another handler.
3864  */
register_gifconf(unsigned int family,gifconf_func_t * gifconf)3865 int register_gifconf(unsigned int family, gifconf_func_t *gifconf)
3866 {
3867 	if (family >= NPROTO)
3868 		return -EINVAL;
3869 	gifconf_list[family] = gifconf;
3870 	return 0;
3871 }
3872 EXPORT_SYMBOL(register_gifconf);
3873 
3874 
3875 /*
3876  *	Map an interface index to its name (SIOCGIFNAME)
3877  */
3878 
3879 /*
3880  *	We need this ioctl for efficient implementation of the
3881  *	if_indextoname() function required by the IPv6 API.  Without
3882  *	it, we would have to search all the interfaces to find a
3883  *	match.  --pb
3884  */
3885 
dev_ifname(struct net * net,struct ifreq __user * arg)3886 static int dev_ifname(struct net *net, struct ifreq __user *arg)
3887 {
3888 	struct net_device *dev;
3889 	struct ifreq ifr;
3890 
3891 	/*
3892 	 *	Fetch the caller's info block.
3893 	 */
3894 
3895 	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
3896 		return -EFAULT;
3897 
3898 	rcu_read_lock();
3899 	dev = dev_get_by_index_rcu(net, ifr.ifr_ifindex);
3900 	if (!dev) {
3901 		rcu_read_unlock();
3902 		return -ENODEV;
3903 	}
3904 
3905 	strcpy(ifr.ifr_name, dev->name);
3906 	rcu_read_unlock();
3907 
3908 	if (copy_to_user(arg, &ifr, sizeof(struct ifreq)))
3909 		return -EFAULT;
3910 	return 0;
3911 }
3912 
3913 /*
3914  *	Perform a SIOCGIFCONF call. This structure will change
3915  *	size eventually, and there is nothing I can do about it.
3916  *	Thus we will need a 'compatibility mode'.
3917  */
3918 
dev_ifconf(struct net * net,char __user * arg)3919 static int dev_ifconf(struct net *net, char __user *arg)
3920 {
3921 	struct ifconf ifc;
3922 	struct net_device *dev;
3923 	char __user *pos;
3924 	int len;
3925 	int total;
3926 	int i;
3927 
3928 	/*
3929 	 *	Fetch the caller's info block.
3930 	 */
3931 
3932 	if (copy_from_user(&ifc, arg, sizeof(struct ifconf)))
3933 		return -EFAULT;
3934 
3935 	pos = ifc.ifc_buf;
3936 	len = ifc.ifc_len;
3937 
3938 	/*
3939 	 *	Loop over the interfaces, and write an info block for each.
3940 	 */
3941 
3942 	total = 0;
3943 	for_each_netdev(net, dev) {
3944 		for (i = 0; i < NPROTO; i++) {
3945 			if (gifconf_list[i]) {
3946 				int done;
3947 				if (!pos)
3948 					done = gifconf_list[i](dev, NULL, 0);
3949 				else
3950 					done = gifconf_list[i](dev, pos + total,
3951 							       len - total);
3952 				if (done < 0)
3953 					return -EFAULT;
3954 				total += done;
3955 			}
3956 		}
3957 	}
3958 
3959 	/*
3960 	 *	All done.  Write the updated control block back to the caller.
3961 	 */
3962 	ifc.ifc_len = total;
3963 
3964 	/*
3965 	 * 	Both BSD and Solaris return 0 here, so we do too.
3966 	 */
3967 	return copy_to_user(arg, &ifc, sizeof(struct ifconf)) ? -EFAULT : 0;
3968 }
3969 
3970 #ifdef CONFIG_PROC_FS
3971 /*
3972  *	This is invoked by the /proc filesystem handler to display a device
3973  *	in detail.
3974  */
dev_seq_start(struct seq_file * seq,loff_t * pos)3975 void *dev_seq_start(struct seq_file *seq, loff_t *pos)
3976 	__acquires(RCU)
3977 {
3978 	struct net *net = seq_file_net(seq);
3979 	loff_t off;
3980 	struct net_device *dev;
3981 
3982 	rcu_read_lock();
3983 	if (!*pos)
3984 		return SEQ_START_TOKEN;
3985 
3986 	off = 1;
3987 	for_each_netdev_rcu(net, dev)
3988 		if (off++ == *pos)
3989 			return dev;
3990 
3991 	return NULL;
3992 }
3993 
dev_seq_next(struct seq_file * seq,void * v,loff_t * pos)3994 void *dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3995 {
3996 	struct net_device *dev = v;
3997 
3998 	if (v == SEQ_START_TOKEN)
3999 		dev = first_net_device_rcu(seq_file_net(seq));
4000 	else
4001 		dev = next_net_device_rcu(dev);
4002 
4003 	++*pos;
4004 	return dev;
4005 }
4006 
dev_seq_stop(struct seq_file * seq,void * v)4007 void dev_seq_stop(struct seq_file *seq, void *v)
4008 	__releases(RCU)
4009 {
4010 	rcu_read_unlock();
4011 }
4012 
dev_seq_printf_stats(struct seq_file * seq,struct net_device * dev)4013 static void dev_seq_printf_stats(struct seq_file *seq, struct net_device *dev)
4014 {
4015 	struct rtnl_link_stats64 temp;
4016 	const struct rtnl_link_stats64 *stats = dev_get_stats(dev, &temp);
4017 
4018 	seq_printf(seq, "%6s: %7llu %7llu %4llu %4llu %4llu %5llu %10llu %9llu "
4019 		   "%8llu %7llu %4llu %4llu %4llu %5llu %7llu %10llu\n",
4020 		   dev->name, stats->rx_bytes, stats->rx_packets,
4021 		   stats->rx_errors,
4022 		   stats->rx_dropped + stats->rx_missed_errors,
4023 		   stats->rx_fifo_errors,
4024 		   stats->rx_length_errors + stats->rx_over_errors +
4025 		    stats->rx_crc_errors + stats->rx_frame_errors,
4026 		   stats->rx_compressed, stats->multicast,
4027 		   stats->tx_bytes, stats->tx_packets,
4028 		   stats->tx_errors, stats->tx_dropped,
4029 		   stats->tx_fifo_errors, stats->collisions,
4030 		   stats->tx_carrier_errors +
4031 		    stats->tx_aborted_errors +
4032 		    stats->tx_window_errors +
4033 		    stats->tx_heartbeat_errors,
4034 		   stats->tx_compressed);
4035 }
4036 
4037 /*
4038  *	Called from the PROCfs module. This now uses the new arbitrary sized
4039  *	/proc/net interface to create /proc/net/dev
4040  */
dev_seq_show(struct seq_file * seq,void * v)4041 static int dev_seq_show(struct seq_file *seq, void *v)
4042 {
4043 	if (v == SEQ_START_TOKEN)
4044 		seq_puts(seq, "Inter-|   Receive                            "
4045 			      "                    |  Transmit\n"
4046 			      " face |bytes    packets errs drop fifo frame "
4047 			      "compressed multicast|bytes    packets errs "
4048 			      "drop fifo colls carrier compressed\n");
4049 	else
4050 		dev_seq_printf_stats(seq, v);
4051 	return 0;
4052 }
4053 
softnet_get_online(loff_t * pos)4054 static struct softnet_data *softnet_get_online(loff_t *pos)
4055 {
4056 	struct softnet_data *sd = NULL;
4057 
4058 	while (*pos < nr_cpu_ids)
4059 		if (cpu_online(*pos)) {
4060 			sd = &per_cpu(softnet_data, *pos);
4061 			break;
4062 		} else
4063 			++*pos;
4064 	return sd;
4065 }
4066 
softnet_seq_start(struct seq_file * seq,loff_t * pos)4067 static void *softnet_seq_start(struct seq_file *seq, loff_t *pos)
4068 {
4069 	return softnet_get_online(pos);
4070 }
4071 
softnet_seq_next(struct seq_file * seq,void * v,loff_t * pos)4072 static void *softnet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4073 {
4074 	++*pos;
4075 	return softnet_get_online(pos);
4076 }
4077 
softnet_seq_stop(struct seq_file * seq,void * v)4078 static void softnet_seq_stop(struct seq_file *seq, void *v)
4079 {
4080 }
4081 
softnet_seq_show(struct seq_file * seq,void * v)4082 static int softnet_seq_show(struct seq_file *seq, void *v)
4083 {
4084 	struct softnet_data *sd = v;
4085 
4086 	seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x %08x %08x %08x\n",
4087 		   sd->processed, sd->dropped, sd->time_squeeze, 0,
4088 		   0, 0, 0, 0, /* was fastroute */
4089 		   sd->cpu_collision, sd->received_rps);
4090 	return 0;
4091 }
4092 
4093 static const struct seq_operations dev_seq_ops = {
4094 	.start = dev_seq_start,
4095 	.next  = dev_seq_next,
4096 	.stop  = dev_seq_stop,
4097 	.show  = dev_seq_show,
4098 };
4099 
dev_seq_open(struct inode * inode,struct file * file)4100 static int dev_seq_open(struct inode *inode, struct file *file)
4101 {
4102 	return seq_open_net(inode, file, &dev_seq_ops,
4103 			    sizeof(struct seq_net_private));
4104 }
4105 
4106 static const struct file_operations dev_seq_fops = {
4107 	.owner	 = THIS_MODULE,
4108 	.open    = dev_seq_open,
4109 	.read    = seq_read,
4110 	.llseek  = seq_lseek,
4111 	.release = seq_release_net,
4112 };
4113 
4114 static const struct seq_operations softnet_seq_ops = {
4115 	.start = softnet_seq_start,
4116 	.next  = softnet_seq_next,
4117 	.stop  = softnet_seq_stop,
4118 	.show  = softnet_seq_show,
4119 };
4120 
softnet_seq_open(struct inode * inode,struct file * file)4121 static int softnet_seq_open(struct inode *inode, struct file *file)
4122 {
4123 	return seq_open(file, &softnet_seq_ops);
4124 }
4125 
4126 static const struct file_operations softnet_seq_fops = {
4127 	.owner	 = THIS_MODULE,
4128 	.open    = softnet_seq_open,
4129 	.read    = seq_read,
4130 	.llseek  = seq_lseek,
4131 	.release = seq_release,
4132 };
4133 
ptype_get_idx(loff_t pos)4134 static void *ptype_get_idx(loff_t pos)
4135 {
4136 	struct packet_type *pt = NULL;
4137 	loff_t i = 0;
4138 	int t;
4139 
4140 	list_for_each_entry_rcu(pt, &ptype_all, list) {
4141 		if (i == pos)
4142 			return pt;
4143 		++i;
4144 	}
4145 
4146 	for (t = 0; t < PTYPE_HASH_SIZE; t++) {
4147 		list_for_each_entry_rcu(pt, &ptype_base[t], list) {
4148 			if (i == pos)
4149 				return pt;
4150 			++i;
4151 		}
4152 	}
4153 	return NULL;
4154 }
4155 
ptype_seq_start(struct seq_file * seq,loff_t * pos)4156 static void *ptype_seq_start(struct seq_file *seq, loff_t *pos)
4157 	__acquires(RCU)
4158 {
4159 	rcu_read_lock();
4160 	return *pos ? ptype_get_idx(*pos - 1) : SEQ_START_TOKEN;
4161 }
4162 
ptype_seq_next(struct seq_file * seq,void * v,loff_t * pos)4163 static void *ptype_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4164 {
4165 	struct packet_type *pt;
4166 	struct list_head *nxt;
4167 	int hash;
4168 
4169 	++*pos;
4170 	if (v == SEQ_START_TOKEN)
4171 		return ptype_get_idx(0);
4172 
4173 	pt = v;
4174 	nxt = pt->list.next;
4175 	if (pt->type == htons(ETH_P_ALL)) {
4176 		if (nxt != &ptype_all)
4177 			goto found;
4178 		hash = 0;
4179 		nxt = ptype_base[0].next;
4180 	} else
4181 		hash = ntohs(pt->type) & PTYPE_HASH_MASK;
4182 
4183 	while (nxt == &ptype_base[hash]) {
4184 		if (++hash >= PTYPE_HASH_SIZE)
4185 			return NULL;
4186 		nxt = ptype_base[hash].next;
4187 	}
4188 found:
4189 	return list_entry(nxt, struct packet_type, list);
4190 }
4191 
ptype_seq_stop(struct seq_file * seq,void * v)4192 static void ptype_seq_stop(struct seq_file *seq, void *v)
4193 	__releases(RCU)
4194 {
4195 	rcu_read_unlock();
4196 }
4197 
ptype_seq_show(struct seq_file * seq,void * v)4198 static int ptype_seq_show(struct seq_file *seq, void *v)
4199 {
4200 	struct packet_type *pt = v;
4201 
4202 	if (v == SEQ_START_TOKEN)
4203 		seq_puts(seq, "Type Device      Function\n");
4204 	else if (pt->dev == NULL || dev_net(pt->dev) == seq_file_net(seq)) {
4205 		if (pt->type == htons(ETH_P_ALL))
4206 			seq_puts(seq, "ALL ");
4207 		else
4208 			seq_printf(seq, "%04x", ntohs(pt->type));
4209 
4210 		seq_printf(seq, " %-8s %pF\n",
4211 			   pt->dev ? pt->dev->name : "", pt->func);
4212 	}
4213 
4214 	return 0;
4215 }
4216 
4217 static const struct seq_operations ptype_seq_ops = {
4218 	.start = ptype_seq_start,
4219 	.next  = ptype_seq_next,
4220 	.stop  = ptype_seq_stop,
4221 	.show  = ptype_seq_show,
4222 };
4223 
ptype_seq_open(struct inode * inode,struct file * file)4224 static int ptype_seq_open(struct inode *inode, struct file *file)
4225 {
4226 	return seq_open_net(inode, file, &ptype_seq_ops,
4227 			sizeof(struct seq_net_private));
4228 }
4229 
4230 static const struct file_operations ptype_seq_fops = {
4231 	.owner	 = THIS_MODULE,
4232 	.open    = ptype_seq_open,
4233 	.read    = seq_read,
4234 	.llseek  = seq_lseek,
4235 	.release = seq_release_net,
4236 };
4237 
4238 
dev_proc_net_init(struct net * net)4239 static int __net_init dev_proc_net_init(struct net *net)
4240 {
4241 	int rc = -ENOMEM;
4242 
4243 	if (!proc_net_fops_create(net, "dev", S_IRUGO, &dev_seq_fops))
4244 		goto out;
4245 	if (!proc_net_fops_create(net, "softnet_stat", S_IRUGO, &softnet_seq_fops))
4246 		goto out_dev;
4247 	if (!proc_net_fops_create(net, "ptype", S_IRUGO, &ptype_seq_fops))
4248 		goto out_softnet;
4249 
4250 	if (wext_proc_init(net))
4251 		goto out_ptype;
4252 	rc = 0;
4253 out:
4254 	return rc;
4255 out_ptype:
4256 	proc_net_remove(net, "ptype");
4257 out_softnet:
4258 	proc_net_remove(net, "softnet_stat");
4259 out_dev:
4260 	proc_net_remove(net, "dev");
4261 	goto out;
4262 }
4263 
dev_proc_net_exit(struct net * net)4264 static void __net_exit dev_proc_net_exit(struct net *net)
4265 {
4266 	wext_proc_exit(net);
4267 
4268 	proc_net_remove(net, "ptype");
4269 	proc_net_remove(net, "softnet_stat");
4270 	proc_net_remove(net, "dev");
4271 }
4272 
4273 static struct pernet_operations __net_initdata dev_proc_ops = {
4274 	.init = dev_proc_net_init,
4275 	.exit = dev_proc_net_exit,
4276 };
4277 
dev_proc_init(void)4278 static int __init dev_proc_init(void)
4279 {
4280 	return register_pernet_subsys(&dev_proc_ops);
4281 }
4282 #else
4283 #define dev_proc_init() 0
4284 #endif	/* CONFIG_PROC_FS */
4285 
4286 
4287 /**
4288  *	netdev_set_master	-	set up master pointer
4289  *	@slave: slave device
4290  *	@master: new master device
4291  *
4292  *	Changes the master device of the slave. Pass %NULL to break the
4293  *	bonding. The caller must hold the RTNL semaphore. On a failure
4294  *	a negative errno code is returned. On success the reference counts
4295  *	are adjusted and the function returns zero.
4296  */
netdev_set_master(struct net_device * slave,struct net_device * master)4297 int netdev_set_master(struct net_device *slave, struct net_device *master)
4298 {
4299 	struct net_device *old = slave->master;
4300 
4301 	ASSERT_RTNL();
4302 
4303 	if (master) {
4304 		if (old)
4305 			return -EBUSY;
4306 		dev_hold(master);
4307 	}
4308 
4309 	slave->master = master;
4310 
4311 	if (old) {
4312 		synchronize_net();
4313 		dev_put(old);
4314 	}
4315 	return 0;
4316 }
4317 EXPORT_SYMBOL(netdev_set_master);
4318 
4319 /**
4320  *	netdev_set_bond_master	-	set up bonding master/slave pair
4321  *	@slave: slave device
4322  *	@master: new master device
4323  *
4324  *	Changes the master device of the slave. Pass %NULL to break the
4325  *	bonding. The caller must hold the RTNL semaphore. On a failure
4326  *	a negative errno code is returned. On success %RTM_NEWLINK is sent
4327  *	to the routing socket and the function returns zero.
4328  */
netdev_set_bond_master(struct net_device * slave,struct net_device * master)4329 int netdev_set_bond_master(struct net_device *slave, struct net_device *master)
4330 {
4331 	int err;
4332 
4333 	ASSERT_RTNL();
4334 
4335 	err = netdev_set_master(slave, master);
4336 	if (err)
4337 		return err;
4338 	if (master)
4339 		slave->flags |= IFF_SLAVE;
4340 	else
4341 		slave->flags &= ~IFF_SLAVE;
4342 
4343 	rtmsg_ifinfo(RTM_NEWLINK, slave, IFF_SLAVE);
4344 	return 0;
4345 }
4346 EXPORT_SYMBOL(netdev_set_bond_master);
4347 
dev_change_rx_flags(struct net_device * dev,int flags)4348 static void dev_change_rx_flags(struct net_device *dev, int flags)
4349 {
4350 	const struct net_device_ops *ops = dev->netdev_ops;
4351 
4352 	if ((dev->flags & IFF_UP) && ops->ndo_change_rx_flags)
4353 		ops->ndo_change_rx_flags(dev, flags);
4354 }
4355 
__dev_set_promiscuity(struct net_device * dev,int inc)4356 static int __dev_set_promiscuity(struct net_device *dev, int inc)
4357 {
4358 	unsigned short old_flags = dev->flags;
4359 	uid_t uid;
4360 	gid_t gid;
4361 
4362 	ASSERT_RTNL();
4363 
4364 	dev->flags |= IFF_PROMISC;
4365 	dev->promiscuity += inc;
4366 	if (dev->promiscuity == 0) {
4367 		/*
4368 		 * Avoid overflow.
4369 		 * If inc causes overflow, untouch promisc and return error.
4370 		 */
4371 		if (inc < 0)
4372 			dev->flags &= ~IFF_PROMISC;
4373 		else {
4374 			dev->promiscuity -= inc;
4375 			printk(KERN_WARNING "%s: promiscuity touches roof, "
4376 				"set promiscuity failed, promiscuity feature "
4377 				"of device might be broken.\n", dev->name);
4378 			return -EOVERFLOW;
4379 		}
4380 	}
4381 	if (dev->flags != old_flags) {
4382 		printk(KERN_INFO "device %s %s promiscuous mode\n",
4383 		       dev->name, (dev->flags & IFF_PROMISC) ? "entered" :
4384 							       "left");
4385 		if (audit_enabled) {
4386 			current_uid_gid(&uid, &gid);
4387 			audit_log(current->audit_context, GFP_ATOMIC,
4388 				AUDIT_ANOM_PROMISCUOUS,
4389 				"dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
4390 				dev->name, (dev->flags & IFF_PROMISC),
4391 				(old_flags & IFF_PROMISC),
4392 				audit_get_loginuid(current),
4393 				uid, gid,
4394 				audit_get_sessionid(current));
4395 		}
4396 
4397 		dev_change_rx_flags(dev, IFF_PROMISC);
4398 	}
4399 	return 0;
4400 }
4401 
4402 /**
4403  *	dev_set_promiscuity	- update promiscuity count on a device
4404  *	@dev: device
4405  *	@inc: modifier
4406  *
4407  *	Add or remove promiscuity from a device. While the count in the device
4408  *	remains above zero the interface remains promiscuous. Once it hits zero
4409  *	the device reverts back to normal filtering operation. A negative inc
4410  *	value is used to drop promiscuity on the device.
4411  *	Return 0 if successful or a negative errno code on error.
4412  */
dev_set_promiscuity(struct net_device * dev,int inc)4413 int dev_set_promiscuity(struct net_device *dev, int inc)
4414 {
4415 	unsigned short old_flags = dev->flags;
4416 	int err;
4417 
4418 	err = __dev_set_promiscuity(dev, inc);
4419 	if (err < 0)
4420 		return err;
4421 	if (dev->flags != old_flags)
4422 		dev_set_rx_mode(dev);
4423 	return err;
4424 }
4425 EXPORT_SYMBOL(dev_set_promiscuity);
4426 
4427 /**
4428  *	dev_set_allmulti	- update allmulti count on a device
4429  *	@dev: device
4430  *	@inc: modifier
4431  *
4432  *	Add or remove reception of all multicast frames to a device. While the
4433  *	count in the device remains above zero the interface remains listening
4434  *	to all interfaces. Once it hits zero the device reverts back to normal
4435  *	filtering operation. A negative @inc value is used to drop the counter
4436  *	when releasing a resource needing all multicasts.
4437  *	Return 0 if successful or a negative errno code on error.
4438  */
4439 
dev_set_allmulti(struct net_device * dev,int inc)4440 int dev_set_allmulti(struct net_device *dev, int inc)
4441 {
4442 	unsigned short old_flags = dev->flags;
4443 
4444 	ASSERT_RTNL();
4445 
4446 	dev->flags |= IFF_ALLMULTI;
4447 	dev->allmulti += inc;
4448 	if (dev->allmulti == 0) {
4449 		/*
4450 		 * Avoid overflow.
4451 		 * If inc causes overflow, untouch allmulti and return error.
4452 		 */
4453 		if (inc < 0)
4454 			dev->flags &= ~IFF_ALLMULTI;
4455 		else {
4456 			dev->allmulti -= inc;
4457 			printk(KERN_WARNING "%s: allmulti touches roof, "
4458 				"set allmulti failed, allmulti feature of "
4459 				"device might be broken.\n", dev->name);
4460 			return -EOVERFLOW;
4461 		}
4462 	}
4463 	if (dev->flags ^ old_flags) {
4464 		dev_change_rx_flags(dev, IFF_ALLMULTI);
4465 		dev_set_rx_mode(dev);
4466 	}
4467 	return 0;
4468 }
4469 EXPORT_SYMBOL(dev_set_allmulti);
4470 
4471 /*
4472  *	Upload unicast and multicast address lists to device and
4473  *	configure RX filtering. When the device doesn't support unicast
4474  *	filtering it is put in promiscuous mode while unicast addresses
4475  *	are present.
4476  */
__dev_set_rx_mode(struct net_device * dev)4477 void __dev_set_rx_mode(struct net_device *dev)
4478 {
4479 	const struct net_device_ops *ops = dev->netdev_ops;
4480 
4481 	/* dev_open will call this function so the list will stay sane. */
4482 	if (!(dev->flags&IFF_UP))
4483 		return;
4484 
4485 	if (!netif_device_present(dev))
4486 		return;
4487 
4488 	if (ops->ndo_set_rx_mode)
4489 		ops->ndo_set_rx_mode(dev);
4490 	else {
4491 		/* Unicast addresses changes may only happen under the rtnl,
4492 		 * therefore calling __dev_set_promiscuity here is safe.
4493 		 */
4494 		if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
4495 			__dev_set_promiscuity(dev, 1);
4496 			dev->uc_promisc = 1;
4497 		} else if (netdev_uc_empty(dev) && dev->uc_promisc) {
4498 			__dev_set_promiscuity(dev, -1);
4499 			dev->uc_promisc = 0;
4500 		}
4501 
4502 		if (ops->ndo_set_multicast_list)
4503 			ops->ndo_set_multicast_list(dev);
4504 	}
4505 }
4506 
dev_set_rx_mode(struct net_device * dev)4507 void dev_set_rx_mode(struct net_device *dev)
4508 {
4509 	netif_addr_lock_bh(dev);
4510 	__dev_set_rx_mode(dev);
4511 	netif_addr_unlock_bh(dev);
4512 }
4513 
4514 /**
4515  *	dev_get_flags - get flags reported to userspace
4516  *	@dev: device
4517  *
4518  *	Get the combination of flag bits exported through APIs to userspace.
4519  */
dev_get_flags(const struct net_device * dev)4520 unsigned dev_get_flags(const struct net_device *dev)
4521 {
4522 	unsigned flags;
4523 
4524 	flags = (dev->flags & ~(IFF_PROMISC |
4525 				IFF_ALLMULTI |
4526 				IFF_RUNNING |
4527 				IFF_LOWER_UP |
4528 				IFF_DORMANT)) |
4529 		(dev->gflags & (IFF_PROMISC |
4530 				IFF_ALLMULTI));
4531 
4532 	if (netif_running(dev)) {
4533 		if (netif_oper_up(dev))
4534 			flags |= IFF_RUNNING;
4535 		if (netif_carrier_ok(dev))
4536 			flags |= IFF_LOWER_UP;
4537 		if (netif_dormant(dev))
4538 			flags |= IFF_DORMANT;
4539 	}
4540 
4541 	return flags;
4542 }
4543 EXPORT_SYMBOL(dev_get_flags);
4544 
__dev_change_flags(struct net_device * dev,unsigned int flags)4545 int __dev_change_flags(struct net_device *dev, unsigned int flags)
4546 {
4547 	int old_flags = dev->flags;
4548 	int ret;
4549 
4550 	ASSERT_RTNL();
4551 
4552 	/*
4553 	 *	Set the flags on our device.
4554 	 */
4555 
4556 	dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
4557 			       IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
4558 			       IFF_AUTOMEDIA)) |
4559 		     (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
4560 				    IFF_ALLMULTI));
4561 
4562 	/*
4563 	 *	Load in the correct multicast list now the flags have changed.
4564 	 */
4565 
4566 	if ((old_flags ^ flags) & IFF_MULTICAST)
4567 		dev_change_rx_flags(dev, IFF_MULTICAST);
4568 
4569 	dev_set_rx_mode(dev);
4570 
4571 	/*
4572 	 *	Have we downed the interface. We handle IFF_UP ourselves
4573 	 *	according to user attempts to set it, rather than blindly
4574 	 *	setting it.
4575 	 */
4576 
4577 	ret = 0;
4578 	if ((old_flags ^ flags) & IFF_UP) {	/* Bit is different  ? */
4579 		ret = ((old_flags & IFF_UP) ? __dev_close : __dev_open)(dev);
4580 
4581 		if (!ret)
4582 			dev_set_rx_mode(dev);
4583 	}
4584 
4585 	if ((flags ^ dev->gflags) & IFF_PROMISC) {
4586 		int inc = (flags & IFF_PROMISC) ? 1 : -1;
4587 
4588 		dev->gflags ^= IFF_PROMISC;
4589 		dev_set_promiscuity(dev, inc);
4590 	}
4591 
4592 	/* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
4593 	   is important. Some (broken) drivers set IFF_PROMISC, when
4594 	   IFF_ALLMULTI is requested not asking us and not reporting.
4595 	 */
4596 	if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
4597 		int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
4598 
4599 		dev->gflags ^= IFF_ALLMULTI;
4600 		dev_set_allmulti(dev, inc);
4601 	}
4602 
4603 	return ret;
4604 }
4605 
__dev_notify_flags(struct net_device * dev,unsigned int old_flags)4606 void __dev_notify_flags(struct net_device *dev, unsigned int old_flags)
4607 {
4608 	unsigned int changes = dev->flags ^ old_flags;
4609 
4610 	if (changes & IFF_UP) {
4611 		if (dev->flags & IFF_UP)
4612 			call_netdevice_notifiers(NETDEV_UP, dev);
4613 		else
4614 			call_netdevice_notifiers(NETDEV_DOWN, dev);
4615 	}
4616 
4617 	if (dev->flags & IFF_UP &&
4618 	    (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE)))
4619 		call_netdevice_notifiers(NETDEV_CHANGE, dev);
4620 }
4621 
4622 /**
4623  *	dev_change_flags - change device settings
4624  *	@dev: device
4625  *	@flags: device state flags
4626  *
4627  *	Change settings on device based state flags. The flags are
4628  *	in the userspace exported format.
4629  */
dev_change_flags(struct net_device * dev,unsigned flags)4630 int dev_change_flags(struct net_device *dev, unsigned flags)
4631 {
4632 	int ret, changes;
4633 	int old_flags = dev->flags;
4634 
4635 	ret = __dev_change_flags(dev, flags);
4636 	if (ret < 0)
4637 		return ret;
4638 
4639 	changes = old_flags ^ dev->flags;
4640 	if (changes)
4641 		rtmsg_ifinfo(RTM_NEWLINK, dev, changes);
4642 
4643 	__dev_notify_flags(dev, old_flags);
4644 	return ret;
4645 }
4646 EXPORT_SYMBOL(dev_change_flags);
4647 
4648 /**
4649  *	dev_set_mtu - Change maximum transfer unit
4650  *	@dev: device
4651  *	@new_mtu: new transfer unit
4652  *
4653  *	Change the maximum transfer size of the network device.
4654  */
dev_set_mtu(struct net_device * dev,int new_mtu)4655 int dev_set_mtu(struct net_device *dev, int new_mtu)
4656 {
4657 	const struct net_device_ops *ops = dev->netdev_ops;
4658 	int err;
4659 
4660 	if (new_mtu == dev->mtu)
4661 		return 0;
4662 
4663 	/*	MTU must be positive.	 */
4664 	if (new_mtu < 0)
4665 		return -EINVAL;
4666 
4667 	if (!netif_device_present(dev))
4668 		return -ENODEV;
4669 
4670 	err = 0;
4671 	if (ops->ndo_change_mtu)
4672 		err = ops->ndo_change_mtu(dev, new_mtu);
4673 	else
4674 		dev->mtu = new_mtu;
4675 
4676 	if (!err && dev->flags & IFF_UP)
4677 		call_netdevice_notifiers(NETDEV_CHANGEMTU, dev);
4678 	return err;
4679 }
4680 EXPORT_SYMBOL(dev_set_mtu);
4681 
4682 /**
4683  *	dev_set_group - Change group this device belongs to
4684  *	@dev: device
4685  *	@new_group: group this device should belong to
4686  */
dev_set_group(struct net_device * dev,int new_group)4687 void dev_set_group(struct net_device *dev, int new_group)
4688 {
4689 	dev->group = new_group;
4690 }
4691 EXPORT_SYMBOL(dev_set_group);
4692 
4693 /**
4694  *	dev_set_mac_address - Change Media Access Control Address
4695  *	@dev: device
4696  *	@sa: new address
4697  *
4698  *	Change the hardware (MAC) address of the device
4699  */
dev_set_mac_address(struct net_device * dev,struct sockaddr * sa)4700 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
4701 {
4702 	const struct net_device_ops *ops = dev->netdev_ops;
4703 	int err;
4704 
4705 	if (!ops->ndo_set_mac_address)
4706 		return -EOPNOTSUPP;
4707 	if (sa->sa_family != dev->type)
4708 		return -EINVAL;
4709 	if (!netif_device_present(dev))
4710 		return -ENODEV;
4711 	err = ops->ndo_set_mac_address(dev, sa);
4712 	if (!err)
4713 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
4714 	return err;
4715 }
4716 EXPORT_SYMBOL(dev_set_mac_address);
4717 
4718 /*
4719  *	Perform the SIOCxIFxxx calls, inside rcu_read_lock()
4720  */
dev_ifsioc_locked(struct net * net,struct ifreq * ifr,unsigned int cmd)4721 static int dev_ifsioc_locked(struct net *net, struct ifreq *ifr, unsigned int cmd)
4722 {
4723 	int err;
4724 	struct net_device *dev = dev_get_by_name_rcu(net, ifr->ifr_name);
4725 
4726 	if (!dev)
4727 		return -ENODEV;
4728 
4729 	switch (cmd) {
4730 	case SIOCGIFFLAGS:	/* Get interface flags */
4731 		ifr->ifr_flags = (short) dev_get_flags(dev);
4732 		return 0;
4733 
4734 	case SIOCGIFMETRIC:	/* Get the metric on the interface
4735 				   (currently unused) */
4736 		ifr->ifr_metric = 0;
4737 		return 0;
4738 
4739 	case SIOCGIFMTU:	/* Get the MTU of a device */
4740 		ifr->ifr_mtu = dev->mtu;
4741 		return 0;
4742 
4743 	case SIOCGIFHWADDR:
4744 		if (!dev->addr_len)
4745 			memset(ifr->ifr_hwaddr.sa_data, 0, sizeof ifr->ifr_hwaddr.sa_data);
4746 		else
4747 			memcpy(ifr->ifr_hwaddr.sa_data, dev->dev_addr,
4748 			       min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
4749 		ifr->ifr_hwaddr.sa_family = dev->type;
4750 		return 0;
4751 
4752 	case SIOCGIFSLAVE:
4753 		err = -EINVAL;
4754 		break;
4755 
4756 	case SIOCGIFMAP:
4757 		ifr->ifr_map.mem_start = dev->mem_start;
4758 		ifr->ifr_map.mem_end   = dev->mem_end;
4759 		ifr->ifr_map.base_addr = dev->base_addr;
4760 		ifr->ifr_map.irq       = dev->irq;
4761 		ifr->ifr_map.dma       = dev->dma;
4762 		ifr->ifr_map.port      = dev->if_port;
4763 		return 0;
4764 
4765 	case SIOCGIFINDEX:
4766 		ifr->ifr_ifindex = dev->ifindex;
4767 		return 0;
4768 
4769 	case SIOCGIFTXQLEN:
4770 		ifr->ifr_qlen = dev->tx_queue_len;
4771 		return 0;
4772 
4773 	default:
4774 		/* dev_ioctl() should ensure this case
4775 		 * is never reached
4776 		 */
4777 		WARN_ON(1);
4778 		err = -ENOTTY;
4779 		break;
4780 
4781 	}
4782 	return err;
4783 }
4784 
4785 /*
4786  *	Perform the SIOCxIFxxx calls, inside rtnl_lock()
4787  */
dev_ifsioc(struct net * net,struct ifreq * ifr,unsigned int cmd)4788 static int dev_ifsioc(struct net *net, struct ifreq *ifr, unsigned int cmd)
4789 {
4790 	int err;
4791 	struct net_device *dev = __dev_get_by_name(net, ifr->ifr_name);
4792 	const struct net_device_ops *ops;
4793 
4794 	if (!dev)
4795 		return -ENODEV;
4796 
4797 	ops = dev->netdev_ops;
4798 
4799 	switch (cmd) {
4800 	case SIOCSIFFLAGS:	/* Set interface flags */
4801 		return dev_change_flags(dev, ifr->ifr_flags);
4802 
4803 	case SIOCSIFMETRIC:	/* Set the metric on the interface
4804 				   (currently unused) */
4805 		return -EOPNOTSUPP;
4806 
4807 	case SIOCSIFMTU:	/* Set the MTU of a device */
4808 		return dev_set_mtu(dev, ifr->ifr_mtu);
4809 
4810 	case SIOCSIFHWADDR:
4811 		return dev_set_mac_address(dev, &ifr->ifr_hwaddr);
4812 
4813 	case SIOCSIFHWBROADCAST:
4814 		if (ifr->ifr_hwaddr.sa_family != dev->type)
4815 			return -EINVAL;
4816 		memcpy(dev->broadcast, ifr->ifr_hwaddr.sa_data,
4817 		       min(sizeof ifr->ifr_hwaddr.sa_data, (size_t) dev->addr_len));
4818 		call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
4819 		return 0;
4820 
4821 	case SIOCSIFMAP:
4822 		if (ops->ndo_set_config) {
4823 			if (!netif_device_present(dev))
4824 				return -ENODEV;
4825 			return ops->ndo_set_config(dev, &ifr->ifr_map);
4826 		}
4827 		return -EOPNOTSUPP;
4828 
4829 	case SIOCADDMULTI:
4830 		if ((!ops->ndo_set_multicast_list && !ops->ndo_set_rx_mode) ||
4831 		    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
4832 			return -EINVAL;
4833 		if (!netif_device_present(dev))
4834 			return -ENODEV;
4835 		return dev_mc_add_global(dev, ifr->ifr_hwaddr.sa_data);
4836 
4837 	case SIOCDELMULTI:
4838 		if ((!ops->ndo_set_multicast_list && !ops->ndo_set_rx_mode) ||
4839 		    ifr->ifr_hwaddr.sa_family != AF_UNSPEC)
4840 			return -EINVAL;
4841 		if (!netif_device_present(dev))
4842 			return -ENODEV;
4843 		return dev_mc_del_global(dev, ifr->ifr_hwaddr.sa_data);
4844 
4845 	case SIOCSIFTXQLEN:
4846 		if (ifr->ifr_qlen < 0)
4847 			return -EINVAL;
4848 		dev->tx_queue_len = ifr->ifr_qlen;
4849 		return 0;
4850 
4851 	case SIOCSIFNAME:
4852 		ifr->ifr_newname[IFNAMSIZ-1] = '\0';
4853 		return dev_change_name(dev, ifr->ifr_newname);
4854 
4855 	/*
4856 	 *	Unknown or private ioctl
4857 	 */
4858 	default:
4859 		if ((cmd >= SIOCDEVPRIVATE &&
4860 		    cmd <= SIOCDEVPRIVATE + 15) ||
4861 		    cmd == SIOCBONDENSLAVE ||
4862 		    cmd == SIOCBONDRELEASE ||
4863 		    cmd == SIOCBONDSETHWADDR ||
4864 		    cmd == SIOCBONDSLAVEINFOQUERY ||
4865 		    cmd == SIOCBONDINFOQUERY ||
4866 		    cmd == SIOCBONDCHANGEACTIVE ||
4867 		    cmd == SIOCGMIIPHY ||
4868 		    cmd == SIOCGMIIREG ||
4869 		    cmd == SIOCSMIIREG ||
4870 		    cmd == SIOCBRADDIF ||
4871 		    cmd == SIOCBRDELIF ||
4872 		    cmd == SIOCSHWTSTAMP ||
4873 		    cmd == SIOCWANDEV) {
4874 			err = -EOPNOTSUPP;
4875 			if (ops->ndo_do_ioctl) {
4876 				if (netif_device_present(dev))
4877 					err = ops->ndo_do_ioctl(dev, ifr, cmd);
4878 				else
4879 					err = -ENODEV;
4880 			}
4881 		} else
4882 			err = -EINVAL;
4883 
4884 	}
4885 	return err;
4886 }
4887 
4888 /*
4889  *	This function handles all "interface"-type I/O control requests. The actual
4890  *	'doing' part of this is dev_ifsioc above.
4891  */
4892 
4893 /**
4894  *	dev_ioctl	-	network device ioctl
4895  *	@net: the applicable net namespace
4896  *	@cmd: command to issue
4897  *	@arg: pointer to a struct ifreq in user space
4898  *
4899  *	Issue ioctl functions to devices. This is normally called by the
4900  *	user space syscall interfaces but can sometimes be useful for
4901  *	other purposes. The return value is the return from the syscall if
4902  *	positive or a negative errno code on error.
4903  */
4904 
dev_ioctl(struct net * net,unsigned int cmd,void __user * arg)4905 int dev_ioctl(struct net *net, unsigned int cmd, void __user *arg)
4906 {
4907 	struct ifreq ifr;
4908 	int ret;
4909 	char *colon;
4910 
4911 	/* One special case: SIOCGIFCONF takes ifconf argument
4912 	   and requires shared lock, because it sleeps writing
4913 	   to user space.
4914 	 */
4915 
4916 	if (cmd == SIOCGIFCONF) {
4917 		rtnl_lock();
4918 		ret = dev_ifconf(net, (char __user *) arg);
4919 		rtnl_unlock();
4920 		return ret;
4921 	}
4922 	if (cmd == SIOCGIFNAME)
4923 		return dev_ifname(net, (struct ifreq __user *)arg);
4924 
4925 	if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
4926 		return -EFAULT;
4927 
4928 	ifr.ifr_name[IFNAMSIZ-1] = 0;
4929 
4930 	colon = strchr(ifr.ifr_name, ':');
4931 	if (colon)
4932 		*colon = 0;
4933 
4934 	/*
4935 	 *	See which interface the caller is talking about.
4936 	 */
4937 
4938 	switch (cmd) {
4939 	/*
4940 	 *	These ioctl calls:
4941 	 *	- can be done by all.
4942 	 *	- atomic and do not require locking.
4943 	 *	- return a value
4944 	 */
4945 	case SIOCGIFFLAGS:
4946 	case SIOCGIFMETRIC:
4947 	case SIOCGIFMTU:
4948 	case SIOCGIFHWADDR:
4949 	case SIOCGIFSLAVE:
4950 	case SIOCGIFMAP:
4951 	case SIOCGIFINDEX:
4952 	case SIOCGIFTXQLEN:
4953 		dev_load(net, ifr.ifr_name);
4954 		rcu_read_lock();
4955 		ret = dev_ifsioc_locked(net, &ifr, cmd);
4956 		rcu_read_unlock();
4957 		if (!ret) {
4958 			if (colon)
4959 				*colon = ':';
4960 			if (copy_to_user(arg, &ifr,
4961 					 sizeof(struct ifreq)))
4962 				ret = -EFAULT;
4963 		}
4964 		return ret;
4965 
4966 	case SIOCETHTOOL:
4967 		dev_load(net, ifr.ifr_name);
4968 		rtnl_lock();
4969 		ret = dev_ethtool(net, &ifr);
4970 		rtnl_unlock();
4971 		if (!ret) {
4972 			if (colon)
4973 				*colon = ':';
4974 			if (copy_to_user(arg, &ifr,
4975 					 sizeof(struct ifreq)))
4976 				ret = -EFAULT;
4977 		}
4978 		return ret;
4979 
4980 	/*
4981 	 *	These ioctl calls:
4982 	 *	- require superuser power.
4983 	 *	- require strict serialization.
4984 	 *	- return a value
4985 	 */
4986 	case SIOCGMIIPHY:
4987 	case SIOCGMIIREG:
4988 	case SIOCSIFNAME:
4989 		if (!capable(CAP_NET_ADMIN))
4990 			return -EPERM;
4991 		dev_load(net, ifr.ifr_name);
4992 		rtnl_lock();
4993 		ret = dev_ifsioc(net, &ifr, cmd);
4994 		rtnl_unlock();
4995 		if (!ret) {
4996 			if (colon)
4997 				*colon = ':';
4998 			if (copy_to_user(arg, &ifr,
4999 					 sizeof(struct ifreq)))
5000 				ret = -EFAULT;
5001 		}
5002 		return ret;
5003 
5004 	/*
5005 	 *	These ioctl calls:
5006 	 *	- require superuser power.
5007 	 *	- require strict serialization.
5008 	 *	- do not return a value
5009 	 */
5010 	case SIOCSIFFLAGS:
5011 	case SIOCSIFMETRIC:
5012 	case SIOCSIFMTU:
5013 	case SIOCSIFMAP:
5014 	case SIOCSIFHWADDR:
5015 	case SIOCSIFSLAVE:
5016 	case SIOCADDMULTI:
5017 	case SIOCDELMULTI:
5018 	case SIOCSIFHWBROADCAST:
5019 	case SIOCSIFTXQLEN:
5020 	case SIOCSMIIREG:
5021 	case SIOCBONDENSLAVE:
5022 	case SIOCBONDRELEASE:
5023 	case SIOCBONDSETHWADDR:
5024 	case SIOCBONDCHANGEACTIVE:
5025 	case SIOCBRADDIF:
5026 	case SIOCBRDELIF:
5027 	case SIOCSHWTSTAMP:
5028 		if (!capable(CAP_NET_ADMIN))
5029 			return -EPERM;
5030 		/* fall through */
5031 	case SIOCBONDSLAVEINFOQUERY:
5032 	case SIOCBONDINFOQUERY:
5033 		dev_load(net, ifr.ifr_name);
5034 		rtnl_lock();
5035 		ret = dev_ifsioc(net, &ifr, cmd);
5036 		rtnl_unlock();
5037 		return ret;
5038 
5039 	case SIOCGIFMEM:
5040 		/* Get the per device memory space. We can add this but
5041 		 * currently do not support it */
5042 	case SIOCSIFMEM:
5043 		/* Set the per device memory buffer space.
5044 		 * Not applicable in our case */
5045 	case SIOCSIFLINK:
5046 		return -ENOTTY;
5047 
5048 	/*
5049 	 *	Unknown or private ioctl.
5050 	 */
5051 	default:
5052 		if (cmd == SIOCWANDEV ||
5053 		    (cmd >= SIOCDEVPRIVATE &&
5054 		     cmd <= SIOCDEVPRIVATE + 15)) {
5055 			dev_load(net, ifr.ifr_name);
5056 			rtnl_lock();
5057 			ret = dev_ifsioc(net, &ifr, cmd);
5058 			rtnl_unlock();
5059 			if (!ret && copy_to_user(arg, &ifr,
5060 						 sizeof(struct ifreq)))
5061 				ret = -EFAULT;
5062 			return ret;
5063 		}
5064 		/* Take care of Wireless Extensions */
5065 		if (cmd >= SIOCIWFIRST && cmd <= SIOCIWLAST)
5066 			return wext_handle_ioctl(net, &ifr, cmd, arg);
5067 		return -ENOTTY;
5068 	}
5069 }
5070 
5071 
5072 /**
5073  *	dev_new_index	-	allocate an ifindex
5074  *	@net: the applicable net namespace
5075  *
5076  *	Returns a suitable unique value for a new device interface
5077  *	number.  The caller must hold the rtnl semaphore or the
5078  *	dev_base_lock to be sure it remains unique.
5079  */
dev_new_index(struct net * net)5080 static int dev_new_index(struct net *net)
5081 {
5082 	static int ifindex;
5083 	for (;;) {
5084 		if (++ifindex <= 0)
5085 			ifindex = 1;
5086 		if (!__dev_get_by_index(net, ifindex))
5087 			return ifindex;
5088 	}
5089 }
5090 
5091 /* Delayed registration/unregisteration */
5092 static LIST_HEAD(net_todo_list);
5093 
net_set_todo(struct net_device * dev)5094 static void net_set_todo(struct net_device *dev)
5095 {
5096 	list_add_tail(&dev->todo_list, &net_todo_list);
5097 }
5098 
rollback_registered_many(struct list_head * head)5099 static void rollback_registered_many(struct list_head *head)
5100 {
5101 	struct net_device *dev, *tmp;
5102 
5103 	BUG_ON(dev_boot_phase);
5104 	ASSERT_RTNL();
5105 
5106 	list_for_each_entry_safe(dev, tmp, head, unreg_list) {
5107 		/* Some devices call without registering
5108 		 * for initialization unwind. Remove those
5109 		 * devices and proceed with the remaining.
5110 		 */
5111 		if (dev->reg_state == NETREG_UNINITIALIZED) {
5112 			pr_debug("unregister_netdevice: device %s/%p never "
5113 				 "was registered\n", dev->name, dev);
5114 
5115 			WARN_ON(1);
5116 			list_del(&dev->unreg_list);
5117 			continue;
5118 		}
5119 
5120 		BUG_ON(dev->reg_state != NETREG_REGISTERED);
5121 	}
5122 
5123 	/* If device is running, close it first. */
5124 	dev_close_many(head);
5125 
5126 	list_for_each_entry(dev, head, unreg_list) {
5127 		/* And unlink it from device chain. */
5128 		unlist_netdevice(dev);
5129 
5130 		dev->reg_state = NETREG_UNREGISTERING;
5131 	}
5132 
5133 	synchronize_net();
5134 
5135 	list_for_each_entry(dev, head, unreg_list) {
5136 		/* Shutdown queueing discipline. */
5137 		dev_shutdown(dev);
5138 
5139 
5140 		/* Notify protocols, that we are about to destroy
5141 		   this device. They should clean all the things.
5142 		*/
5143 		call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
5144 
5145 		if (!dev->rtnl_link_ops ||
5146 		    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
5147 			rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
5148 
5149 		/*
5150 		 *	Flush the unicast and multicast chains
5151 		 */
5152 		dev_uc_flush(dev);
5153 		dev_mc_flush(dev);
5154 
5155 		if (dev->netdev_ops->ndo_uninit)
5156 			dev->netdev_ops->ndo_uninit(dev);
5157 
5158 		/* Notifier chain MUST detach us from master device. */
5159 		WARN_ON(dev->master);
5160 
5161 		/* Remove entries from kobject tree */
5162 		netdev_unregister_kobject(dev);
5163 	}
5164 
5165 	/* Process any work delayed until the end of the batch */
5166 	dev = list_first_entry(head, struct net_device, unreg_list);
5167 	call_netdevice_notifiers(NETDEV_UNREGISTER_BATCH, dev);
5168 
5169 	rcu_barrier();
5170 
5171 	list_for_each_entry(dev, head, unreg_list)
5172 		dev_put(dev);
5173 }
5174 
rollback_registered(struct net_device * dev)5175 static void rollback_registered(struct net_device *dev)
5176 {
5177 	LIST_HEAD(single);
5178 
5179 	list_add(&dev->unreg_list, &single);
5180 	rollback_registered_many(&single);
5181 	list_del(&single);
5182 }
5183 
netdev_fix_features(struct net_device * dev,u32 features)5184 u32 netdev_fix_features(struct net_device *dev, u32 features)
5185 {
5186 	/* Fix illegal checksum combinations */
5187 	if ((features & NETIF_F_HW_CSUM) &&
5188 	    (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
5189 		netdev_warn(dev, "mixed HW and IP checksum settings.\n");
5190 		features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
5191 	}
5192 
5193 	if ((features & NETIF_F_NO_CSUM) &&
5194 	    (features & (NETIF_F_HW_CSUM|NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
5195 		netdev_warn(dev, "mixed no checksumming and other settings.\n");
5196 		features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM|NETIF_F_HW_CSUM);
5197 	}
5198 
5199 	/* Fix illegal SG+CSUM combinations. */
5200 	if ((features & NETIF_F_SG) &&
5201 	    !(features & NETIF_F_ALL_CSUM)) {
5202 		netdev_dbg(dev,
5203 			"Dropping NETIF_F_SG since no checksum feature.\n");
5204 		features &= ~NETIF_F_SG;
5205 	}
5206 
5207 	/* TSO requires that SG is present as well. */
5208 	if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
5209 		netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
5210 		features &= ~NETIF_F_ALL_TSO;
5211 	}
5212 
5213 	/* TSO ECN requires that TSO is present as well. */
5214 	if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
5215 		features &= ~NETIF_F_TSO_ECN;
5216 
5217 	/* Software GSO depends on SG. */
5218 	if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
5219 		netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
5220 		features &= ~NETIF_F_GSO;
5221 	}
5222 
5223 	/* UFO needs SG and checksumming */
5224 	if (features & NETIF_F_UFO) {
5225 		/* maybe split UFO into V4 and V6? */
5226 		if (!((features & NETIF_F_GEN_CSUM) ||
5227 		    (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))
5228 			    == (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
5229 			netdev_dbg(dev,
5230 				"Dropping NETIF_F_UFO since no checksum offload features.\n");
5231 			features &= ~NETIF_F_UFO;
5232 		}
5233 
5234 		if (!(features & NETIF_F_SG)) {
5235 			netdev_dbg(dev,
5236 				"Dropping NETIF_F_UFO since no NETIF_F_SG feature.\n");
5237 			features &= ~NETIF_F_UFO;
5238 		}
5239 	}
5240 
5241 	return features;
5242 }
5243 EXPORT_SYMBOL(netdev_fix_features);
5244 
netdev_update_features(struct net_device * dev)5245 void netdev_update_features(struct net_device *dev)
5246 {
5247 	u32 features;
5248 	int err = 0;
5249 
5250 	features = netdev_get_wanted_features(dev);
5251 
5252 	if (dev->netdev_ops->ndo_fix_features)
5253 		features = dev->netdev_ops->ndo_fix_features(dev, features);
5254 
5255 	/* driver might be less strict about feature dependencies */
5256 	features = netdev_fix_features(dev, features);
5257 
5258 	if (dev->features == features)
5259 		return;
5260 
5261 	netdev_info(dev, "Features changed: 0x%08x -> 0x%08x\n",
5262 		dev->features, features);
5263 
5264 	if (dev->netdev_ops->ndo_set_features)
5265 		err = dev->netdev_ops->ndo_set_features(dev, features);
5266 
5267 	if (!err)
5268 		dev->features = features;
5269 	else if (err < 0)
5270 		netdev_err(dev,
5271 			"set_features() failed (%d); wanted 0x%08x, left 0x%08x\n",
5272 			err, features, dev->features);
5273 }
5274 EXPORT_SYMBOL(netdev_update_features);
5275 
5276 /**
5277  *	netif_stacked_transfer_operstate -	transfer operstate
5278  *	@rootdev: the root or lower level device to transfer state from
5279  *	@dev: the device to transfer operstate to
5280  *
5281  *	Transfer operational state from root to device. This is normally
5282  *	called when a stacking relationship exists between the root
5283  *	device and the device(a leaf device).
5284  */
netif_stacked_transfer_operstate(const struct net_device * rootdev,struct net_device * dev)5285 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
5286 					struct net_device *dev)
5287 {
5288 	if (rootdev->operstate == IF_OPER_DORMANT)
5289 		netif_dormant_on(dev);
5290 	else
5291 		netif_dormant_off(dev);
5292 
5293 	if (netif_carrier_ok(rootdev)) {
5294 		if (!netif_carrier_ok(dev))
5295 			netif_carrier_on(dev);
5296 	} else {
5297 		if (netif_carrier_ok(dev))
5298 			netif_carrier_off(dev);
5299 	}
5300 }
5301 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
5302 
5303 #ifdef CONFIG_RPS
netif_alloc_rx_queues(struct net_device * dev)5304 static int netif_alloc_rx_queues(struct net_device *dev)
5305 {
5306 	unsigned int i, count = dev->num_rx_queues;
5307 	struct netdev_rx_queue *rx;
5308 
5309 	BUG_ON(count < 1);
5310 
5311 	rx = kcalloc(count, sizeof(struct netdev_rx_queue), GFP_KERNEL);
5312 	if (!rx) {
5313 		pr_err("netdev: Unable to allocate %u rx queues.\n", count);
5314 		return -ENOMEM;
5315 	}
5316 	dev->_rx = rx;
5317 
5318 	for (i = 0; i < count; i++)
5319 		rx[i].dev = dev;
5320 	return 0;
5321 }
5322 #endif
5323 
netdev_init_one_queue(struct net_device * dev,struct netdev_queue * queue,void * _unused)5324 static void netdev_init_one_queue(struct net_device *dev,
5325 				  struct netdev_queue *queue, void *_unused)
5326 {
5327 	/* Initialize queue lock */
5328 	spin_lock_init(&queue->_xmit_lock);
5329 	netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
5330 	queue->xmit_lock_owner = -1;
5331 	netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
5332 	queue->dev = dev;
5333 }
5334 
netif_alloc_netdev_queues(struct net_device * dev)5335 static int netif_alloc_netdev_queues(struct net_device *dev)
5336 {
5337 	unsigned int count = dev->num_tx_queues;
5338 	struct netdev_queue *tx;
5339 
5340 	BUG_ON(count < 1);
5341 
5342 	tx = kcalloc(count, sizeof(struct netdev_queue), GFP_KERNEL);
5343 	if (!tx) {
5344 		pr_err("netdev: Unable to allocate %u tx queues.\n",
5345 		       count);
5346 		return -ENOMEM;
5347 	}
5348 	dev->_tx = tx;
5349 
5350 	netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
5351 	spin_lock_init(&dev->tx_global_lock);
5352 
5353 	return 0;
5354 }
5355 
5356 /**
5357  *	register_netdevice	- register a network device
5358  *	@dev: device to register
5359  *
5360  *	Take a completed network device structure and add it to the kernel
5361  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
5362  *	chain. 0 is returned on success. A negative errno code is returned
5363  *	on a failure to set up the device, or if the name is a duplicate.
5364  *
5365  *	Callers must hold the rtnl semaphore. You may want
5366  *	register_netdev() instead of this.
5367  *
5368  *	BUGS:
5369  *	The locking appears insufficient to guarantee two parallel registers
5370  *	will not get the same name.
5371  */
5372 
register_netdevice(struct net_device * dev)5373 int register_netdevice(struct net_device *dev)
5374 {
5375 	int ret;
5376 	struct net *net = dev_net(dev);
5377 
5378 	BUG_ON(dev_boot_phase);
5379 	ASSERT_RTNL();
5380 
5381 	might_sleep();
5382 
5383 	/* When net_device's are persistent, this will be fatal. */
5384 	BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
5385 	BUG_ON(!net);
5386 
5387 	spin_lock_init(&dev->addr_list_lock);
5388 	netdev_set_addr_lockdep_class(dev);
5389 
5390 	dev->iflink = -1;
5391 
5392 	/* Init, if this function is available */
5393 	if (dev->netdev_ops->ndo_init) {
5394 		ret = dev->netdev_ops->ndo_init(dev);
5395 		if (ret) {
5396 			if (ret > 0)
5397 				ret = -EIO;
5398 			goto out;
5399 		}
5400 	}
5401 
5402 	ret = dev_get_valid_name(dev, dev->name, 0);
5403 	if (ret)
5404 		goto err_uninit;
5405 
5406 	dev->ifindex = dev_new_index(net);
5407 	if (dev->iflink == -1)
5408 		dev->iflink = dev->ifindex;
5409 
5410 	/* Transfer changeable features to wanted_features and enable
5411 	 * software offloads (GSO and GRO).
5412 	 */
5413 	dev->hw_features |= NETIF_F_SOFT_FEATURES;
5414 	dev->features |= NETIF_F_SOFT_FEATURES;
5415 	dev->wanted_features = dev->features & dev->hw_features;
5416 
5417 	/* Enable GRO and NETIF_F_HIGHDMA for vlans by default,
5418 	 * vlan_dev_init() will do the dev->features check, so these features
5419 	 * are enabled only if supported by underlying device.
5420 	 */
5421 	dev->vlan_features |= (NETIF_F_GRO | NETIF_F_HIGHDMA);
5422 
5423 	ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
5424 	ret = notifier_to_errno(ret);
5425 	if (ret)
5426 		goto err_uninit;
5427 
5428 	ret = netdev_register_kobject(dev);
5429 	if (ret)
5430 		goto err_uninit;
5431 	dev->reg_state = NETREG_REGISTERED;
5432 
5433 	netdev_update_features(dev);
5434 
5435 	/*
5436 	 *	Default initial state at registry is that the
5437 	 *	device is present.
5438 	 */
5439 
5440 	set_bit(__LINK_STATE_PRESENT, &dev->state);
5441 
5442 	dev_init_scheduler(dev);
5443 	dev_hold(dev);
5444 	list_netdevice(dev);
5445 
5446 	/* Notify protocols, that a new device appeared. */
5447 	ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
5448 	ret = notifier_to_errno(ret);
5449 	if (ret) {
5450 		rollback_registered(dev);
5451 		dev->reg_state = NETREG_UNREGISTERED;
5452 	}
5453 	/*
5454 	 *	Prevent userspace races by waiting until the network
5455 	 *	device is fully setup before sending notifications.
5456 	 */
5457 	if (!dev->rtnl_link_ops ||
5458 	    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
5459 		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
5460 
5461 out:
5462 	return ret;
5463 
5464 err_uninit:
5465 	if (dev->netdev_ops->ndo_uninit)
5466 		dev->netdev_ops->ndo_uninit(dev);
5467 	goto out;
5468 }
5469 EXPORT_SYMBOL(register_netdevice);
5470 
5471 /**
5472  *	init_dummy_netdev	- init a dummy network device for NAPI
5473  *	@dev: device to init
5474  *
5475  *	This takes a network device structure and initialize the minimum
5476  *	amount of fields so it can be used to schedule NAPI polls without
5477  *	registering a full blown interface. This is to be used by drivers
5478  *	that need to tie several hardware interfaces to a single NAPI
5479  *	poll scheduler due to HW limitations.
5480  */
init_dummy_netdev(struct net_device * dev)5481 int init_dummy_netdev(struct net_device *dev)
5482 {
5483 	/* Clear everything. Note we don't initialize spinlocks
5484 	 * are they aren't supposed to be taken by any of the
5485 	 * NAPI code and this dummy netdev is supposed to be
5486 	 * only ever used for NAPI polls
5487 	 */
5488 	memset(dev, 0, sizeof(struct net_device));
5489 
5490 	/* make sure we BUG if trying to hit standard
5491 	 * register/unregister code path
5492 	 */
5493 	dev->reg_state = NETREG_DUMMY;
5494 
5495 	/* NAPI wants this */
5496 	INIT_LIST_HEAD(&dev->napi_list);
5497 
5498 	/* a dummy interface is started by default */
5499 	set_bit(__LINK_STATE_PRESENT, &dev->state);
5500 	set_bit(__LINK_STATE_START, &dev->state);
5501 
5502 	/* Note : We dont allocate pcpu_refcnt for dummy devices,
5503 	 * because users of this 'device' dont need to change
5504 	 * its refcount.
5505 	 */
5506 
5507 	return 0;
5508 }
5509 EXPORT_SYMBOL_GPL(init_dummy_netdev);
5510 
5511 
5512 /**
5513  *	register_netdev	- register a network device
5514  *	@dev: device to register
5515  *
5516  *	Take a completed network device structure and add it to the kernel
5517  *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
5518  *	chain. 0 is returned on success. A negative errno code is returned
5519  *	on a failure to set up the device, or if the name is a duplicate.
5520  *
5521  *	This is a wrapper around register_netdevice that takes the rtnl semaphore
5522  *	and expands the device name if you passed a format string to
5523  *	alloc_netdev.
5524  */
register_netdev(struct net_device * dev)5525 int register_netdev(struct net_device *dev)
5526 {
5527 	int err;
5528 
5529 	rtnl_lock();
5530 
5531 	/*
5532 	 * If the name is a format string the caller wants us to do a
5533 	 * name allocation.
5534 	 */
5535 	if (strchr(dev->name, '%')) {
5536 		err = dev_alloc_name(dev, dev->name);
5537 		if (err < 0)
5538 			goto out;
5539 	}
5540 
5541 	err = register_netdevice(dev);
5542 out:
5543 	rtnl_unlock();
5544 	return err;
5545 }
5546 EXPORT_SYMBOL(register_netdev);
5547 
netdev_refcnt_read(const struct net_device * dev)5548 int netdev_refcnt_read(const struct net_device *dev)
5549 {
5550 	int i, refcnt = 0;
5551 
5552 	for_each_possible_cpu(i)
5553 		refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
5554 	return refcnt;
5555 }
5556 EXPORT_SYMBOL(netdev_refcnt_read);
5557 
5558 /*
5559  * netdev_wait_allrefs - wait until all references are gone.
5560  *
5561  * This is called when unregistering network devices.
5562  *
5563  * Any protocol or device that holds a reference should register
5564  * for netdevice notification, and cleanup and put back the
5565  * reference if they receive an UNREGISTER event.
5566  * We can get stuck here if buggy protocols don't correctly
5567  * call dev_put.
5568  */
netdev_wait_allrefs(struct net_device * dev)5569 static void netdev_wait_allrefs(struct net_device *dev)
5570 {
5571 	unsigned long rebroadcast_time, warning_time;
5572 	int refcnt;
5573 
5574 	linkwatch_forget_dev(dev);
5575 
5576 	rebroadcast_time = warning_time = jiffies;
5577 	refcnt = netdev_refcnt_read(dev);
5578 
5579 	while (refcnt != 0) {
5580 		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
5581 			rtnl_lock();
5582 
5583 			/* Rebroadcast unregister notification */
5584 			call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
5585 			/* don't resend NETDEV_UNREGISTER_BATCH, _BATCH users
5586 			 * should have already handle it the first time */
5587 
5588 			if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
5589 				     &dev->state)) {
5590 				/* We must not have linkwatch events
5591 				 * pending on unregister. If this
5592 				 * happens, we simply run the queue
5593 				 * unscheduled, resulting in a noop
5594 				 * for this device.
5595 				 */
5596 				linkwatch_run_queue();
5597 			}
5598 
5599 			__rtnl_unlock();
5600 
5601 			rebroadcast_time = jiffies;
5602 		}
5603 
5604 		msleep(250);
5605 
5606 		refcnt = netdev_refcnt_read(dev);
5607 
5608 		if (time_after(jiffies, warning_time + 10 * HZ)) {
5609 			printk(KERN_EMERG "unregister_netdevice: "
5610 			       "waiting for %s to become free. Usage "
5611 			       "count = %d\n",
5612 			       dev->name, refcnt);
5613 			warning_time = jiffies;
5614 		}
5615 	}
5616 }
5617 
5618 /* The sequence is:
5619  *
5620  *	rtnl_lock();
5621  *	...
5622  *	register_netdevice(x1);
5623  *	register_netdevice(x2);
5624  *	...
5625  *	unregister_netdevice(y1);
5626  *	unregister_netdevice(y2);
5627  *      ...
5628  *	rtnl_unlock();
5629  *	free_netdev(y1);
5630  *	free_netdev(y2);
5631  *
5632  * We are invoked by rtnl_unlock().
5633  * This allows us to deal with problems:
5634  * 1) We can delete sysfs objects which invoke hotplug
5635  *    without deadlocking with linkwatch via keventd.
5636  * 2) Since we run with the RTNL semaphore not held, we can sleep
5637  *    safely in order to wait for the netdev refcnt to drop to zero.
5638  *
5639  * We must not return until all unregister events added during
5640  * the interval the lock was held have been completed.
5641  */
netdev_run_todo(void)5642 void netdev_run_todo(void)
5643 {
5644 	struct list_head list;
5645 
5646 	/* Snapshot list, allow later requests */
5647 	list_replace_init(&net_todo_list, &list);
5648 
5649 	__rtnl_unlock();
5650 
5651 	while (!list_empty(&list)) {
5652 		struct net_device *dev
5653 			= list_first_entry(&list, struct net_device, todo_list);
5654 		list_del(&dev->todo_list);
5655 
5656 		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
5657 			printk(KERN_ERR "network todo '%s' but state %d\n",
5658 			       dev->name, dev->reg_state);
5659 			dump_stack();
5660 			continue;
5661 		}
5662 
5663 		dev->reg_state = NETREG_UNREGISTERED;
5664 
5665 		on_each_cpu(flush_backlog, dev, 1);
5666 
5667 		netdev_wait_allrefs(dev);
5668 
5669 		/* paranoia */
5670 		BUG_ON(netdev_refcnt_read(dev));
5671 		WARN_ON(rcu_dereference_raw(dev->ip_ptr));
5672 		WARN_ON(rcu_dereference_raw(dev->ip6_ptr));
5673 		WARN_ON(dev->dn_ptr);
5674 
5675 		if (dev->destructor)
5676 			dev->destructor(dev);
5677 
5678 		/* Free network device */
5679 		kobject_put(&dev->dev.kobj);
5680 	}
5681 }
5682 
5683 /* Convert net_device_stats to rtnl_link_stats64.  They have the same
5684  * fields in the same order, with only the type differing.
5685  */
netdev_stats_to_stats64(struct rtnl_link_stats64 * stats64,const struct net_device_stats * netdev_stats)5686 static void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
5687 				    const struct net_device_stats *netdev_stats)
5688 {
5689 #if BITS_PER_LONG == 64
5690         BUILD_BUG_ON(sizeof(*stats64) != sizeof(*netdev_stats));
5691         memcpy(stats64, netdev_stats, sizeof(*stats64));
5692 #else
5693 	size_t i, n = sizeof(*stats64) / sizeof(u64);
5694 	const unsigned long *src = (const unsigned long *)netdev_stats;
5695 	u64 *dst = (u64 *)stats64;
5696 
5697 	BUILD_BUG_ON(sizeof(*netdev_stats) / sizeof(unsigned long) !=
5698 		     sizeof(*stats64) / sizeof(u64));
5699 	for (i = 0; i < n; i++)
5700 		dst[i] = src[i];
5701 #endif
5702 }
5703 
5704 /**
5705  *	dev_get_stats	- get network device statistics
5706  *	@dev: device to get statistics from
5707  *	@storage: place to store stats
5708  *
5709  *	Get network statistics from device. Return @storage.
5710  *	The device driver may provide its own method by setting
5711  *	dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
5712  *	otherwise the internal statistics structure is used.
5713  */
dev_get_stats(struct net_device * dev,struct rtnl_link_stats64 * storage)5714 struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
5715 					struct rtnl_link_stats64 *storage)
5716 {
5717 	const struct net_device_ops *ops = dev->netdev_ops;
5718 
5719 	if (ops->ndo_get_stats64) {
5720 		memset(storage, 0, sizeof(*storage));
5721 		ops->ndo_get_stats64(dev, storage);
5722 	} else if (ops->ndo_get_stats) {
5723 		netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
5724 	} else {
5725 		netdev_stats_to_stats64(storage, &dev->stats);
5726 	}
5727 	storage->rx_dropped += atomic_long_read(&dev->rx_dropped);
5728 	return storage;
5729 }
5730 EXPORT_SYMBOL(dev_get_stats);
5731 
dev_ingress_queue_create(struct net_device * dev)5732 struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
5733 {
5734 	struct netdev_queue *queue = dev_ingress_queue(dev);
5735 
5736 #ifdef CONFIG_NET_CLS_ACT
5737 	if (queue)
5738 		return queue;
5739 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
5740 	if (!queue)
5741 		return NULL;
5742 	netdev_init_one_queue(dev, queue, NULL);
5743 	queue->qdisc = &noop_qdisc;
5744 	queue->qdisc_sleeping = &noop_qdisc;
5745 	rcu_assign_pointer(dev->ingress_queue, queue);
5746 #endif
5747 	return queue;
5748 }
5749 
5750 /**
5751  *	alloc_netdev_mqs - allocate network device
5752  *	@sizeof_priv:	size of private data to allocate space for
5753  *	@name:		device name format string
5754  *	@setup:		callback to initialize device
5755  *	@txqs:		the number of TX subqueues to allocate
5756  *	@rxqs:		the number of RX subqueues to allocate
5757  *
5758  *	Allocates a struct net_device with private data area for driver use
5759  *	and performs basic initialization.  Also allocates subquue structs
5760  *	for each queue on the device.
5761  */
alloc_netdev_mqs(int sizeof_priv,const char * name,void (* setup)(struct net_device *),unsigned int txqs,unsigned int rxqs)5762 struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
5763 		void (*setup)(struct net_device *),
5764 		unsigned int txqs, unsigned int rxqs)
5765 {
5766 	struct net_device *dev;
5767 	size_t alloc_size;
5768 	struct net_device *p;
5769 
5770 	BUG_ON(strlen(name) >= sizeof(dev->name));
5771 
5772 	if (txqs < 1) {
5773 		pr_err("alloc_netdev: Unable to allocate device "
5774 		       "with zero queues.\n");
5775 		return NULL;
5776 	}
5777 
5778 #ifdef CONFIG_RPS
5779 	if (rxqs < 1) {
5780 		pr_err("alloc_netdev: Unable to allocate device "
5781 		       "with zero RX queues.\n");
5782 		return NULL;
5783 	}
5784 #endif
5785 
5786 	alloc_size = sizeof(struct net_device);
5787 	if (sizeof_priv) {
5788 		/* ensure 32-byte alignment of private area */
5789 		alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
5790 		alloc_size += sizeof_priv;
5791 	}
5792 	/* ensure 32-byte alignment of whole construct */
5793 	alloc_size += NETDEV_ALIGN - 1;
5794 
5795 	p = kzalloc(alloc_size, GFP_KERNEL);
5796 	if (!p) {
5797 		printk(KERN_ERR "alloc_netdev: Unable to allocate device.\n");
5798 		return NULL;
5799 	}
5800 
5801 	dev = PTR_ALIGN(p, NETDEV_ALIGN);
5802 	dev->padded = (char *)dev - (char *)p;
5803 
5804 	dev->pcpu_refcnt = alloc_percpu(int);
5805 	if (!dev->pcpu_refcnt)
5806 		goto free_p;
5807 
5808 	if (dev_addr_init(dev))
5809 		goto free_pcpu;
5810 
5811 	dev_mc_init(dev);
5812 	dev_uc_init(dev);
5813 
5814 	dev_net_set(dev, &init_net);
5815 
5816 	dev->gso_max_size = GSO_MAX_SIZE;
5817 
5818 	INIT_LIST_HEAD(&dev->ethtool_ntuple_list.list);
5819 	dev->ethtool_ntuple_list.count = 0;
5820 	INIT_LIST_HEAD(&dev->napi_list);
5821 	INIT_LIST_HEAD(&dev->unreg_list);
5822 	INIT_LIST_HEAD(&dev->link_watch_list);
5823 	dev->priv_flags = IFF_XMIT_DST_RELEASE;
5824 	setup(dev);
5825 
5826 	dev->num_tx_queues = txqs;
5827 	dev->real_num_tx_queues = txqs;
5828 	if (netif_alloc_netdev_queues(dev))
5829 		goto free_all;
5830 
5831 #ifdef CONFIG_RPS
5832 	dev->num_rx_queues = rxqs;
5833 	dev->real_num_rx_queues = rxqs;
5834 	if (netif_alloc_rx_queues(dev))
5835 		goto free_all;
5836 #endif
5837 
5838 	strcpy(dev->name, name);
5839 	dev->group = INIT_NETDEV_GROUP;
5840 	return dev;
5841 
5842 free_all:
5843 	free_netdev(dev);
5844 	return NULL;
5845 
5846 free_pcpu:
5847 	free_percpu(dev->pcpu_refcnt);
5848 	kfree(dev->_tx);
5849 #ifdef CONFIG_RPS
5850 	kfree(dev->_rx);
5851 #endif
5852 
5853 free_p:
5854 	kfree(p);
5855 	return NULL;
5856 }
5857 EXPORT_SYMBOL(alloc_netdev_mqs);
5858 
5859 /**
5860  *	free_netdev - free network device
5861  *	@dev: device
5862  *
5863  *	This function does the last stage of destroying an allocated device
5864  * 	interface. The reference to the device object is released.
5865  *	If this is the last reference then it will be freed.
5866  */
free_netdev(struct net_device * dev)5867 void free_netdev(struct net_device *dev)
5868 {
5869 	struct napi_struct *p, *n;
5870 
5871 	release_net(dev_net(dev));
5872 
5873 	kfree(dev->_tx);
5874 #ifdef CONFIG_RPS
5875 	kfree(dev->_rx);
5876 #endif
5877 
5878 	kfree(rcu_dereference_raw(dev->ingress_queue));
5879 
5880 	/* Flush device addresses */
5881 	dev_addr_flush(dev);
5882 
5883 	/* Clear ethtool n-tuple list */
5884 	ethtool_ntuple_flush(dev);
5885 
5886 	list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
5887 		netif_napi_del(p);
5888 
5889 	free_percpu(dev->pcpu_refcnt);
5890 	dev->pcpu_refcnt = NULL;
5891 
5892 	/*  Compatibility with error handling in drivers */
5893 	if (dev->reg_state == NETREG_UNINITIALIZED) {
5894 		kfree((char *)dev - dev->padded);
5895 		return;
5896 	}
5897 
5898 	BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
5899 	dev->reg_state = NETREG_RELEASED;
5900 
5901 	/* will free via device release */
5902 	put_device(&dev->dev);
5903 }
5904 EXPORT_SYMBOL(free_netdev);
5905 
5906 /**
5907  *	synchronize_net -  Synchronize with packet receive processing
5908  *
5909  *	Wait for packets currently being received to be done.
5910  *	Does not block later packets from starting.
5911  */
synchronize_net(void)5912 void synchronize_net(void)
5913 {
5914 	might_sleep();
5915 	synchronize_rcu();
5916 }
5917 EXPORT_SYMBOL(synchronize_net);
5918 
5919 /**
5920  *	unregister_netdevice_queue - remove device from the kernel
5921  *	@dev: device
5922  *	@head: list
5923  *
5924  *	This function shuts down a device interface and removes it
5925  *	from the kernel tables.
5926  *	If head not NULL, device is queued to be unregistered later.
5927  *
5928  *	Callers must hold the rtnl semaphore.  You may want
5929  *	unregister_netdev() instead of this.
5930  */
5931 
unregister_netdevice_queue(struct net_device * dev,struct list_head * head)5932 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
5933 {
5934 	ASSERT_RTNL();
5935 
5936 	if (head) {
5937 		list_move_tail(&dev->unreg_list, head);
5938 	} else {
5939 		rollback_registered(dev);
5940 		/* Finish processing unregister after unlock */
5941 		net_set_todo(dev);
5942 	}
5943 }
5944 EXPORT_SYMBOL(unregister_netdevice_queue);
5945 
5946 /**
5947  *	unregister_netdevice_many - unregister many devices
5948  *	@head: list of devices
5949  */
unregister_netdevice_many(struct list_head * head)5950 void unregister_netdevice_many(struct list_head *head)
5951 {
5952 	struct net_device *dev;
5953 
5954 	if (!list_empty(head)) {
5955 		rollback_registered_many(head);
5956 		list_for_each_entry(dev, head, unreg_list)
5957 			net_set_todo(dev);
5958 	}
5959 }
5960 EXPORT_SYMBOL(unregister_netdevice_many);
5961 
5962 /**
5963  *	unregister_netdev - remove device from the kernel
5964  *	@dev: device
5965  *
5966  *	This function shuts down a device interface and removes it
5967  *	from the kernel tables.
5968  *
5969  *	This is just a wrapper for unregister_netdevice that takes
5970  *	the rtnl semaphore.  In general you want to use this and not
5971  *	unregister_netdevice.
5972  */
unregister_netdev(struct net_device * dev)5973 void unregister_netdev(struct net_device *dev)
5974 {
5975 	rtnl_lock();
5976 	unregister_netdevice(dev);
5977 	rtnl_unlock();
5978 }
5979 EXPORT_SYMBOL(unregister_netdev);
5980 
5981 /**
5982  *	dev_change_net_namespace - move device to different nethost namespace
5983  *	@dev: device
5984  *	@net: network namespace
5985  *	@pat: If not NULL name pattern to try if the current device name
5986  *	      is already taken in the destination network namespace.
5987  *
5988  *	This function shuts down a device interface and moves it
5989  *	to a new network namespace. On success 0 is returned, on
5990  *	a failure a netagive errno code is returned.
5991  *
5992  *	Callers must hold the rtnl semaphore.
5993  */
5994 
dev_change_net_namespace(struct net_device * dev,struct net * net,const char * pat)5995 int dev_change_net_namespace(struct net_device *dev, struct net *net, const char *pat)
5996 {
5997 	int err;
5998 
5999 	ASSERT_RTNL();
6000 
6001 	/* Don't allow namespace local devices to be moved. */
6002 	err = -EINVAL;
6003 	if (dev->features & NETIF_F_NETNS_LOCAL)
6004 		goto out;
6005 
6006 	/* Ensure the device has been registrered */
6007 	err = -EINVAL;
6008 	if (dev->reg_state != NETREG_REGISTERED)
6009 		goto out;
6010 
6011 	/* Get out if there is nothing todo */
6012 	err = 0;
6013 	if (net_eq(dev_net(dev), net))
6014 		goto out;
6015 
6016 	/* Pick the destination device name, and ensure
6017 	 * we can use it in the destination network namespace.
6018 	 */
6019 	err = -EEXIST;
6020 	if (__dev_get_by_name(net, dev->name)) {
6021 		/* We get here if we can't use the current device name */
6022 		if (!pat)
6023 			goto out;
6024 		if (dev_get_valid_name(dev, pat, 1))
6025 			goto out;
6026 	}
6027 
6028 	/*
6029 	 * And now a mini version of register_netdevice unregister_netdevice.
6030 	 */
6031 
6032 	/* If device is running close it first. */
6033 	dev_close(dev);
6034 
6035 	/* And unlink it from device chain */
6036 	err = -ENODEV;
6037 	unlist_netdevice(dev);
6038 
6039 	synchronize_net();
6040 
6041 	/* Shutdown queueing discipline. */
6042 	dev_shutdown(dev);
6043 
6044 	/* Notify protocols, that we are about to destroy
6045 	   this device. They should clean all the things.
6046 
6047 	   Note that dev->reg_state stays at NETREG_REGISTERED.
6048 	   This is wanted because this way 8021q and macvlan know
6049 	   the device is just moving and can keep their slaves up.
6050 	*/
6051 	call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
6052 	call_netdevice_notifiers(NETDEV_UNREGISTER_BATCH, dev);
6053 
6054 	/*
6055 	 *	Flush the unicast and multicast chains
6056 	 */
6057 	dev_uc_flush(dev);
6058 	dev_mc_flush(dev);
6059 
6060 	/* Actually switch the network namespace */
6061 	dev_net_set(dev, net);
6062 
6063 	/* If there is an ifindex conflict assign a new one */
6064 	if (__dev_get_by_index(net, dev->ifindex)) {
6065 		int iflink = (dev->iflink == dev->ifindex);
6066 		dev->ifindex = dev_new_index(net);
6067 		if (iflink)
6068 			dev->iflink = dev->ifindex;
6069 	}
6070 
6071 	/* Fixup kobjects */
6072 	err = device_rename(&dev->dev, dev->name);
6073 	WARN_ON(err);
6074 
6075 	/* Add the device back in the hashes */
6076 	list_netdevice(dev);
6077 
6078 	/* Notify protocols, that a new device appeared. */
6079 	call_netdevice_notifiers(NETDEV_REGISTER, dev);
6080 
6081 	/*
6082 	 *	Prevent userspace races by waiting until the network
6083 	 *	device is fully setup before sending notifications.
6084 	 */
6085 	rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
6086 
6087 	synchronize_net();
6088 	err = 0;
6089 out:
6090 	return err;
6091 }
6092 EXPORT_SYMBOL_GPL(dev_change_net_namespace);
6093 
dev_cpu_callback(struct notifier_block * nfb,unsigned long action,void * ocpu)6094 static int dev_cpu_callback(struct notifier_block *nfb,
6095 			    unsigned long action,
6096 			    void *ocpu)
6097 {
6098 	struct sk_buff **list_skb;
6099 	struct sk_buff *skb;
6100 	unsigned int cpu, oldcpu = (unsigned long)ocpu;
6101 	struct softnet_data *sd, *oldsd;
6102 
6103 	if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
6104 		return NOTIFY_OK;
6105 
6106 	local_irq_disable();
6107 	cpu = smp_processor_id();
6108 	sd = &per_cpu(softnet_data, cpu);
6109 	oldsd = &per_cpu(softnet_data, oldcpu);
6110 
6111 	/* Find end of our completion_queue. */
6112 	list_skb = &sd->completion_queue;
6113 	while (*list_skb)
6114 		list_skb = &(*list_skb)->next;
6115 	/* Append completion queue from offline CPU. */
6116 	*list_skb = oldsd->completion_queue;
6117 	oldsd->completion_queue = NULL;
6118 
6119 	/* Append output queue from offline CPU. */
6120 	if (oldsd->output_queue) {
6121 		*sd->output_queue_tailp = oldsd->output_queue;
6122 		sd->output_queue_tailp = oldsd->output_queue_tailp;
6123 		oldsd->output_queue = NULL;
6124 		oldsd->output_queue_tailp = &oldsd->output_queue;
6125 	}
6126 
6127 	raise_softirq_irqoff(NET_TX_SOFTIRQ);
6128 	local_irq_enable();
6129 
6130 	/* Process offline CPU's input_pkt_queue */
6131 	while ((skb = __skb_dequeue(&oldsd->process_queue))) {
6132 		netif_rx(skb);
6133 		input_queue_head_incr(oldsd);
6134 	}
6135 	while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) {
6136 		netif_rx(skb);
6137 		input_queue_head_incr(oldsd);
6138 	}
6139 
6140 	return NOTIFY_OK;
6141 }
6142 
6143 
6144 /**
6145  *	netdev_increment_features - increment feature set by one
6146  *	@all: current feature set
6147  *	@one: new feature set
6148  *	@mask: mask feature set
6149  *
6150  *	Computes a new feature set after adding a device with feature set
6151  *	@one to the master device with current feature set @all.  Will not
6152  *	enable anything that is off in @mask. Returns the new feature set.
6153  */
netdev_increment_features(u32 all,u32 one,u32 mask)6154 u32 netdev_increment_features(u32 all, u32 one, u32 mask)
6155 {
6156 	/* If device needs checksumming, downgrade to it. */
6157 	if (all & NETIF_F_NO_CSUM && !(one & NETIF_F_NO_CSUM))
6158 		all ^= NETIF_F_NO_CSUM | (one & NETIF_F_ALL_CSUM);
6159 	else if (mask & NETIF_F_ALL_CSUM) {
6160 		/* If one device supports v4/v6 checksumming, set for all. */
6161 		if (one & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM) &&
6162 		    !(all & NETIF_F_GEN_CSUM)) {
6163 			all &= ~NETIF_F_ALL_CSUM;
6164 			all |= one & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM);
6165 		}
6166 
6167 		/* If one device supports hw checksumming, set for all. */
6168 		if (one & NETIF_F_GEN_CSUM && !(all & NETIF_F_GEN_CSUM)) {
6169 			all &= ~NETIF_F_ALL_CSUM;
6170 			all |= NETIF_F_HW_CSUM;
6171 		}
6172 	}
6173 
6174 	one |= NETIF_F_ALL_CSUM;
6175 
6176 	one |= all & NETIF_F_ONE_FOR_ALL;
6177 	all &= one | NETIF_F_LLTX | NETIF_F_GSO | NETIF_F_UFO;
6178 	all |= one & mask & NETIF_F_ONE_FOR_ALL;
6179 
6180 	return all;
6181 }
6182 EXPORT_SYMBOL(netdev_increment_features);
6183 
netdev_create_hash(void)6184 static struct hlist_head *netdev_create_hash(void)
6185 {
6186 	int i;
6187 	struct hlist_head *hash;
6188 
6189 	hash = kmalloc(sizeof(*hash) * NETDEV_HASHENTRIES, GFP_KERNEL);
6190 	if (hash != NULL)
6191 		for (i = 0; i < NETDEV_HASHENTRIES; i++)
6192 			INIT_HLIST_HEAD(&hash[i]);
6193 
6194 	return hash;
6195 }
6196 
6197 /* Initialize per network namespace state */
netdev_init(struct net * net)6198 static int __net_init netdev_init(struct net *net)
6199 {
6200 	INIT_LIST_HEAD(&net->dev_base_head);
6201 
6202 	net->dev_name_head = netdev_create_hash();
6203 	if (net->dev_name_head == NULL)
6204 		goto err_name;
6205 
6206 	net->dev_index_head = netdev_create_hash();
6207 	if (net->dev_index_head == NULL)
6208 		goto err_idx;
6209 
6210 	return 0;
6211 
6212 err_idx:
6213 	kfree(net->dev_name_head);
6214 err_name:
6215 	return -ENOMEM;
6216 }
6217 
6218 /**
6219  *	netdev_drivername - network driver for the device
6220  *	@dev: network device
6221  *	@buffer: buffer for resulting name
6222  *	@len: size of buffer
6223  *
6224  *	Determine network driver for device.
6225  */
netdev_drivername(const struct net_device * dev,char * buffer,int len)6226 char *netdev_drivername(const struct net_device *dev, char *buffer, int len)
6227 {
6228 	const struct device_driver *driver;
6229 	const struct device *parent;
6230 
6231 	if (len <= 0 || !buffer)
6232 		return buffer;
6233 	buffer[0] = 0;
6234 
6235 	parent = dev->dev.parent;
6236 
6237 	if (!parent)
6238 		return buffer;
6239 
6240 	driver = parent->driver;
6241 	if (driver && driver->name)
6242 		strlcpy(buffer, driver->name, len);
6243 	return buffer;
6244 }
6245 
__netdev_printk(const char * level,const struct net_device * dev,struct va_format * vaf)6246 static int __netdev_printk(const char *level, const struct net_device *dev,
6247 			   struct va_format *vaf)
6248 {
6249 	int r;
6250 
6251 	if (dev && dev->dev.parent)
6252 		r = dev_printk(level, dev->dev.parent, "%s: %pV",
6253 			       netdev_name(dev), vaf);
6254 	else if (dev)
6255 		r = printk("%s%s: %pV", level, netdev_name(dev), vaf);
6256 	else
6257 		r = printk("%s(NULL net_device): %pV", level, vaf);
6258 
6259 	return r;
6260 }
6261 
netdev_printk(const char * level,const struct net_device * dev,const char * format,...)6262 int netdev_printk(const char *level, const struct net_device *dev,
6263 		  const char *format, ...)
6264 {
6265 	struct va_format vaf;
6266 	va_list args;
6267 	int r;
6268 
6269 	va_start(args, format);
6270 
6271 	vaf.fmt = format;
6272 	vaf.va = &args;
6273 
6274 	r = __netdev_printk(level, dev, &vaf);
6275 	va_end(args);
6276 
6277 	return r;
6278 }
6279 EXPORT_SYMBOL(netdev_printk);
6280 
6281 #define define_netdev_printk_level(func, level)			\
6282 int func(const struct net_device *dev, const char *fmt, ...)	\
6283 {								\
6284 	int r;							\
6285 	struct va_format vaf;					\
6286 	va_list args;						\
6287 								\
6288 	va_start(args, fmt);					\
6289 								\
6290 	vaf.fmt = fmt;						\
6291 	vaf.va = &args;						\
6292 								\
6293 	r = __netdev_printk(level, dev, &vaf);			\
6294 	va_end(args);						\
6295 								\
6296 	return r;						\
6297 }								\
6298 EXPORT_SYMBOL(func);
6299 
6300 define_netdev_printk_level(netdev_emerg, KERN_EMERG);
6301 define_netdev_printk_level(netdev_alert, KERN_ALERT);
6302 define_netdev_printk_level(netdev_crit, KERN_CRIT);
6303 define_netdev_printk_level(netdev_err, KERN_ERR);
6304 define_netdev_printk_level(netdev_warn, KERN_WARNING);
6305 define_netdev_printk_level(netdev_notice, KERN_NOTICE);
6306 define_netdev_printk_level(netdev_info, KERN_INFO);
6307 
netdev_exit(struct net * net)6308 static void __net_exit netdev_exit(struct net *net)
6309 {
6310 	kfree(net->dev_name_head);
6311 	kfree(net->dev_index_head);
6312 }
6313 
6314 static struct pernet_operations __net_initdata netdev_net_ops = {
6315 	.init = netdev_init,
6316 	.exit = netdev_exit,
6317 };
6318 
default_device_exit(struct net * net)6319 static void __net_exit default_device_exit(struct net *net)
6320 {
6321 	struct net_device *dev, *aux;
6322 	/*
6323 	 * Push all migratable network devices back to the
6324 	 * initial network namespace
6325 	 */
6326 	rtnl_lock();
6327 	for_each_netdev_safe(net, dev, aux) {
6328 		int err;
6329 		char fb_name[IFNAMSIZ];
6330 
6331 		/* Ignore unmoveable devices (i.e. loopback) */
6332 		if (dev->features & NETIF_F_NETNS_LOCAL)
6333 			continue;
6334 
6335 		/* Leave virtual devices for the generic cleanup */
6336 		if (dev->rtnl_link_ops)
6337 			continue;
6338 
6339 		/* Push remaining network devices to init_net */
6340 		snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
6341 		err = dev_change_net_namespace(dev, &init_net, fb_name);
6342 		if (err) {
6343 			printk(KERN_EMERG "%s: failed to move %s to init_net: %d\n",
6344 				__func__, dev->name, err);
6345 			BUG();
6346 		}
6347 	}
6348 	rtnl_unlock();
6349 }
6350 
default_device_exit_batch(struct list_head * net_list)6351 static void __net_exit default_device_exit_batch(struct list_head *net_list)
6352 {
6353 	/* At exit all network devices most be removed from a network
6354 	 * namespace.  Do this in the reverse order of registration.
6355 	 * Do this across as many network namespaces as possible to
6356 	 * improve batching efficiency.
6357 	 */
6358 	struct net_device *dev;
6359 	struct net *net;
6360 	LIST_HEAD(dev_kill_list);
6361 
6362 	rtnl_lock();
6363 	list_for_each_entry(net, net_list, exit_list) {
6364 		for_each_netdev_reverse(net, dev) {
6365 			if (dev->rtnl_link_ops)
6366 				dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
6367 			else
6368 				unregister_netdevice_queue(dev, &dev_kill_list);
6369 		}
6370 	}
6371 	unregister_netdevice_many(&dev_kill_list);
6372 	list_del(&dev_kill_list);
6373 	rtnl_unlock();
6374 }
6375 
6376 static struct pernet_operations __net_initdata default_device_ops = {
6377 	.exit = default_device_exit,
6378 	.exit_batch = default_device_exit_batch,
6379 };
6380 
6381 /*
6382  *	Initialize the DEV module. At boot time this walks the device list and
6383  *	unhooks any devices that fail to initialise (normally hardware not
6384  *	present) and leaves us with a valid list of present and active devices.
6385  *
6386  */
6387 
6388 /*
6389  *       This is called single threaded during boot, so no need
6390  *       to take the rtnl semaphore.
6391  */
net_dev_init(void)6392 static int __init net_dev_init(void)
6393 {
6394 	int i, rc = -ENOMEM;
6395 
6396 	BUG_ON(!dev_boot_phase);
6397 
6398 	if (dev_proc_init())
6399 		goto out;
6400 
6401 	if (netdev_kobject_init())
6402 		goto out;
6403 
6404 	INIT_LIST_HEAD(&ptype_all);
6405 	for (i = 0; i < PTYPE_HASH_SIZE; i++)
6406 		INIT_LIST_HEAD(&ptype_base[i]);
6407 
6408 	if (register_pernet_subsys(&netdev_net_ops))
6409 		goto out;
6410 
6411 	/*
6412 	 *	Initialise the packet receive queues.
6413 	 */
6414 
6415 	for_each_possible_cpu(i) {
6416 		struct softnet_data *sd = &per_cpu(softnet_data, i);
6417 
6418 		memset(sd, 0, sizeof(*sd));
6419 		skb_queue_head_init(&sd->input_pkt_queue);
6420 		skb_queue_head_init(&sd->process_queue);
6421 		sd->completion_queue = NULL;
6422 		INIT_LIST_HEAD(&sd->poll_list);
6423 		sd->output_queue = NULL;
6424 		sd->output_queue_tailp = &sd->output_queue;
6425 #ifdef CONFIG_RPS
6426 		sd->csd.func = rps_trigger_softirq;
6427 		sd->csd.info = sd;
6428 		sd->csd.flags = 0;
6429 		sd->cpu = i;
6430 #endif
6431 
6432 		sd->backlog.poll = process_backlog;
6433 		sd->backlog.weight = weight_p;
6434 		sd->backlog.gro_list = NULL;
6435 		sd->backlog.gro_count = 0;
6436 	}
6437 
6438 	dev_boot_phase = 0;
6439 
6440 	/* The loopback device is special if any other network devices
6441 	 * is present in a network namespace the loopback device must
6442 	 * be present. Since we now dynamically allocate and free the
6443 	 * loopback device ensure this invariant is maintained by
6444 	 * keeping the loopback device as the first device on the
6445 	 * list of network devices.  Ensuring the loopback devices
6446 	 * is the first device that appears and the last network device
6447 	 * that disappears.
6448 	 */
6449 	if (register_pernet_device(&loopback_net_ops))
6450 		goto out;
6451 
6452 	if (register_pernet_device(&default_device_ops))
6453 		goto out;
6454 
6455 	open_softirq(NET_TX_SOFTIRQ, net_tx_action);
6456 	open_softirq(NET_RX_SOFTIRQ, net_rx_action);
6457 
6458 	hotcpu_notifier(dev_cpu_callback, 0);
6459 	dst_init();
6460 	dev_mcast_init();
6461 	rc = 0;
6462 out:
6463 	return rc;
6464 }
6465 
6466 subsys_initcall(net_dev_init);
6467 
initialize_hashrnd(void)6468 static int __init initialize_hashrnd(void)
6469 {
6470 	get_random_bytes(&hashrnd, sizeof(hashrnd));
6471 	return 0;
6472 }
6473 
6474 late_initcall_sync(initialize_hashrnd);
6475 
6476