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