2 * NET3 Protocol independent device support routines.
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.
9 * Derived from the non IP parts of dev.c 1.0.19
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Mark Evans, <evansmp@uhura.aston.ac.uk>
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>
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
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
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
51 * Rudi Cilibrasi : Pass the right thing to
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
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
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
75 #include <asm/uaccess.h>
76 #include <linux/bitops.h>
77 #include <linux/capability.h>
78 #include <linux/cpu.h>
79 #include <linux/types.h>
80 #include <linux/kernel.h>
81 #include <linux/hash.h>
82 #include <linux/slab.h>
83 #include <linux/sched.h>
84 #include <linux/mutex.h>
85 #include <linux/string.h>
87 #include <linux/socket.h>
88 #include <linux/sockios.h>
89 #include <linux/errno.h>
90 #include <linux/interrupt.h>
91 #include <linux/if_ether.h>
92 #include <linux/netdevice.h>
93 #include <linux/etherdevice.h>
94 #include <linux/ethtool.h>
95 #include <linux/notifier.h>
96 #include <linux/skbuff.h>
97 #include <net/net_namespace.h>
99 #include <linux/rtnetlink.h>
100 #include <linux/stat.h>
102 #include <net/pkt_sched.h>
103 #include <net/checksum.h>
104 #include <net/xfrm.h>
105 #include <linux/highmem.h>
106 #include <linux/init.h>
107 #include <linux/module.h>
108 #include <linux/netpoll.h>
109 #include <linux/rcupdate.h>
110 #include <linux/delay.h>
111 #include <net/iw_handler.h>
112 #include <asm/current.h>
113 #include <linux/audit.h>
114 #include <linux/dmaengine.h>
115 #include <linux/err.h>
116 #include <linux/ctype.h>
117 #include <linux/if_arp.h>
118 #include <linux/if_vlan.h>
119 #include <linux/ip.h>
121 #include <linux/ipv6.h>
122 #include <linux/in.h>
123 #include <linux/jhash.h>
124 #include <linux/random.h>
125 #include <trace/events/napi.h>
126 #include <trace/events/net.h>
127 #include <trace/events/skb.h>
128 #include <linux/pci.h>
129 #include <linux/inetdevice.h>
130 #include <linux/cpu_rmap.h>
131 #include <linux/static_key.h>
132 #include <linux/hashtable.h>
133 #include <linux/vmalloc.h>
134 #include <linux/if_macvlan.h>
136 #include "net-sysfs.h"
138 /* Instead of increasing this, you should create a hash table. */
139 #define MAX_GRO_SKBS 8
141 /* This should be increased if a protocol with a bigger head is added. */
142 #define GRO_MAX_HEAD (MAX_HEADER + 128)
144 static DEFINE_SPINLOCK(ptype_lock);
145 static DEFINE_SPINLOCK(offload_lock);
146 struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
147 struct list_head ptype_all __read_mostly; /* Taps */
148 static struct list_head offload_base __read_mostly;
150 static int netif_rx_internal(struct sk_buff *skb);
153 * The @dev_base_head list is protected by @dev_base_lock and the rtnl
156 * Pure readers hold dev_base_lock for reading, or rcu_read_lock()
158 * Writers must hold the rtnl semaphore while they loop through the
159 * dev_base_head list, and hold dev_base_lock for writing when they do the
160 * actual updates. This allows pure readers to access the list even
161 * while a writer is preparing to update it.
163 * To put it another way, dev_base_lock is held for writing only to
164 * protect against pure readers; the rtnl semaphore provides the
165 * protection against other writers.
167 * See, for example usages, register_netdevice() and
168 * unregister_netdevice(), which must be called with the rtnl
171 DEFINE_RWLOCK(dev_base_lock);
172 EXPORT_SYMBOL(dev_base_lock);
174 /* protects napi_hash addition/deletion and napi_gen_id */
175 static DEFINE_SPINLOCK(napi_hash_lock);
177 static unsigned int napi_gen_id;
178 static DEFINE_HASHTABLE(napi_hash, 8);
180 static seqcount_t devnet_rename_seq;
182 static inline void dev_base_seq_inc(struct net *net)
184 while (++net->dev_base_seq == 0);
187 static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
189 unsigned int hash = full_name_hash(name, strnlen(name, IFNAMSIZ));
191 return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
194 static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
196 return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
199 static inline void rps_lock(struct softnet_data *sd)
202 spin_lock(&sd->input_pkt_queue.lock);
206 static inline void rps_unlock(struct softnet_data *sd)
209 spin_unlock(&sd->input_pkt_queue.lock);
213 /* Device list insertion */
214 static void list_netdevice(struct net_device *dev)
216 struct net *net = dev_net(dev);
220 write_lock_bh(&dev_base_lock);
221 list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
222 hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
223 hlist_add_head_rcu(&dev->index_hlist,
224 dev_index_hash(net, dev->ifindex));
225 write_unlock_bh(&dev_base_lock);
227 dev_base_seq_inc(net);
230 /* Device list removal
231 * caller must respect a RCU grace period before freeing/reusing dev
233 static void unlist_netdevice(struct net_device *dev)
237 /* Unlink dev from the device chain */
238 write_lock_bh(&dev_base_lock);
239 list_del_rcu(&dev->dev_list);
240 hlist_del_rcu(&dev->name_hlist);
241 hlist_del_rcu(&dev->index_hlist);
242 write_unlock_bh(&dev_base_lock);
244 dev_base_seq_inc(dev_net(dev));
251 static RAW_NOTIFIER_HEAD(netdev_chain);
254 * Device drivers call our routines to queue packets here. We empty the
255 * queue in the local softnet handler.
258 DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
259 EXPORT_PER_CPU_SYMBOL(softnet_data);
261 #ifdef CONFIG_LOCKDEP
263 * register_netdevice() inits txq->_xmit_lock and sets lockdep class
264 * according to dev->type
266 static const unsigned short netdev_lock_type[] =
267 {ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
268 ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
269 ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
270 ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
271 ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
272 ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
273 ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
274 ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
275 ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
276 ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
277 ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
278 ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
279 ARPHRD_FCFABRIC, ARPHRD_IEEE80211, ARPHRD_IEEE80211_PRISM,
280 ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET, ARPHRD_PHONET_PIPE,
281 ARPHRD_IEEE802154, ARPHRD_VOID, ARPHRD_NONE};
283 static const char *const netdev_lock_name[] =
284 {"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
285 "_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
286 "_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
287 "_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
288 "_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
289 "_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
290 "_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
291 "_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
292 "_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
293 "_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
294 "_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
295 "_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
296 "_xmit_FCFABRIC", "_xmit_IEEE80211", "_xmit_IEEE80211_PRISM",
297 "_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET", "_xmit_PHONET_PIPE",
298 "_xmit_IEEE802154", "_xmit_VOID", "_xmit_NONE"};
300 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
301 static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
303 static inline unsigned short netdev_lock_pos(unsigned short dev_type)
307 for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
308 if (netdev_lock_type[i] == dev_type)
310 /* the last key is used by default */
311 return ARRAY_SIZE(netdev_lock_type) - 1;
314 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
315 unsigned short dev_type)
319 i = netdev_lock_pos(dev_type);
320 lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
321 netdev_lock_name[i]);
324 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
328 i = netdev_lock_pos(dev->type);
329 lockdep_set_class_and_name(&dev->addr_list_lock,
330 &netdev_addr_lock_key[i],
331 netdev_lock_name[i]);
334 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
335 unsigned short dev_type)
338 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
343 /*******************************************************************************
345 Protocol management and registration routines
347 *******************************************************************************/
350 * Add a protocol ID to the list. Now that the input handler is
351 * smarter we can dispense with all the messy stuff that used to be
354 * BEWARE!!! Protocol handlers, mangling input packets,
355 * MUST BE last in hash buckets and checking protocol handlers
356 * MUST start from promiscuous ptype_all chain in net_bh.
357 * It is true now, do not change it.
358 * Explanation follows: if protocol handler, mangling packet, will
359 * be the first on list, it is not able to sense, that packet
360 * is cloned and should be copied-on-write, so that it will
361 * change it and subsequent readers will get broken packet.
365 static inline struct list_head *ptype_head(const struct packet_type *pt)
367 if (pt->type == htons(ETH_P_ALL))
370 return &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
374 * dev_add_pack - add packet handler
375 * @pt: packet type declaration
377 * Add a protocol handler to the networking stack. The passed &packet_type
378 * is linked into kernel lists and may not be freed until it has been
379 * removed from the kernel lists.
381 * This call does not sleep therefore it can not
382 * guarantee all CPU's that are in middle of receiving packets
383 * will see the new packet type (until the next received packet).
386 void dev_add_pack(struct packet_type *pt)
388 struct list_head *head = ptype_head(pt);
390 spin_lock(&ptype_lock);
391 list_add_rcu(&pt->list, head);
392 spin_unlock(&ptype_lock);
394 EXPORT_SYMBOL(dev_add_pack);
397 * __dev_remove_pack - remove packet handler
398 * @pt: packet type declaration
400 * Remove a protocol handler that was previously added to the kernel
401 * protocol handlers by dev_add_pack(). The passed &packet_type is removed
402 * from the kernel lists and can be freed or reused once this function
405 * The packet type might still be in use by receivers
406 * and must not be freed until after all the CPU's have gone
407 * through a quiescent state.
409 void __dev_remove_pack(struct packet_type *pt)
411 struct list_head *head = ptype_head(pt);
412 struct packet_type *pt1;
414 spin_lock(&ptype_lock);
416 list_for_each_entry(pt1, head, list) {
418 list_del_rcu(&pt->list);
423 pr_warn("dev_remove_pack: %p not found\n", pt);
425 spin_unlock(&ptype_lock);
427 EXPORT_SYMBOL(__dev_remove_pack);
430 * dev_remove_pack - remove packet handler
431 * @pt: packet type declaration
433 * Remove a protocol handler that was previously added to the kernel
434 * protocol handlers by dev_add_pack(). The passed &packet_type is removed
435 * from the kernel lists and can be freed or reused once this function
438 * This call sleeps to guarantee that no CPU is looking at the packet
441 void dev_remove_pack(struct packet_type *pt)
443 __dev_remove_pack(pt);
447 EXPORT_SYMBOL(dev_remove_pack);
451 * dev_add_offload - register offload handlers
452 * @po: protocol offload declaration
454 * Add protocol offload handlers to the networking stack. The passed
455 * &proto_offload is linked into kernel lists and may not be freed until
456 * it has been removed from the kernel lists.
458 * This call does not sleep therefore it can not
459 * guarantee all CPU's that are in middle of receiving packets
460 * will see the new offload handlers (until the next received packet).
462 void dev_add_offload(struct packet_offload *po)
464 struct list_head *head = &offload_base;
466 spin_lock(&offload_lock);
467 list_add_rcu(&po->list, head);
468 spin_unlock(&offload_lock);
470 EXPORT_SYMBOL(dev_add_offload);
473 * __dev_remove_offload - remove offload handler
474 * @po: packet offload declaration
476 * Remove a protocol offload handler that was previously added to the
477 * kernel offload handlers by dev_add_offload(). The passed &offload_type
478 * is removed from the kernel lists and can be freed or reused once this
481 * The packet type might still be in use by receivers
482 * and must not be freed until after all the CPU's have gone
483 * through a quiescent state.
485 static void __dev_remove_offload(struct packet_offload *po)
487 struct list_head *head = &offload_base;
488 struct packet_offload *po1;
490 spin_lock(&offload_lock);
492 list_for_each_entry(po1, head, list) {
494 list_del_rcu(&po->list);
499 pr_warn("dev_remove_offload: %p not found\n", po);
501 spin_unlock(&offload_lock);
505 * dev_remove_offload - remove packet offload handler
506 * @po: packet offload declaration
508 * Remove a packet offload handler that was previously added to the kernel
509 * offload handlers by dev_add_offload(). The passed &offload_type is
510 * removed from the kernel lists and can be freed or reused once this
513 * This call sleeps to guarantee that no CPU is looking at the packet
516 void dev_remove_offload(struct packet_offload *po)
518 __dev_remove_offload(po);
522 EXPORT_SYMBOL(dev_remove_offload);
524 /******************************************************************************
526 Device Boot-time Settings Routines
528 *******************************************************************************/
530 /* Boot time configuration table */
531 static struct netdev_boot_setup dev_boot_setup[NETDEV_BOOT_SETUP_MAX];
534 * netdev_boot_setup_add - add new setup entry
535 * @name: name of the device
536 * @map: configured settings for the device
538 * Adds new setup entry to the dev_boot_setup list. The function
539 * returns 0 on error and 1 on success. This is a generic routine to
542 static int netdev_boot_setup_add(char *name, struct ifmap *map)
544 struct netdev_boot_setup *s;
548 for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
549 if (s[i].name[0] == '\0' || s[i].name[0] == ' ') {
550 memset(s[i].name, 0, sizeof(s[i].name));
551 strlcpy(s[i].name, name, IFNAMSIZ);
552 memcpy(&s[i].map, map, sizeof(s[i].map));
557 return i >= NETDEV_BOOT_SETUP_MAX ? 0 : 1;
561 * netdev_boot_setup_check - check boot time settings
562 * @dev: the netdevice
564 * Check boot time settings for the device.
565 * The found settings are set for the device to be used
566 * later in the device probing.
567 * Returns 0 if no settings found, 1 if they are.
569 int netdev_boot_setup_check(struct net_device *dev)
571 struct netdev_boot_setup *s = dev_boot_setup;
574 for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
575 if (s[i].name[0] != '\0' && s[i].name[0] != ' ' &&
576 !strcmp(dev->name, s[i].name)) {
577 dev->irq = s[i].map.irq;
578 dev->base_addr = s[i].map.base_addr;
579 dev->mem_start = s[i].map.mem_start;
580 dev->mem_end = s[i].map.mem_end;
586 EXPORT_SYMBOL(netdev_boot_setup_check);
590 * netdev_boot_base - get address from boot time settings
591 * @prefix: prefix for network device
592 * @unit: id for network device
594 * Check boot time settings for the base address of device.
595 * The found settings are set for the device to be used
596 * later in the device probing.
597 * Returns 0 if no settings found.
599 unsigned long netdev_boot_base(const char *prefix, int unit)
601 const struct netdev_boot_setup *s = dev_boot_setup;
605 sprintf(name, "%s%d", prefix, unit);
608 * If device already registered then return base of 1
609 * to indicate not to probe for this interface
611 if (__dev_get_by_name(&init_net, name))
614 for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++)
615 if (!strcmp(name, s[i].name))
616 return s[i].map.base_addr;
621 * Saves at boot time configured settings for any netdevice.
623 int __init netdev_boot_setup(char *str)
628 str = get_options(str, ARRAY_SIZE(ints), ints);
633 memset(&map, 0, sizeof(map));
637 map.base_addr = ints[2];
639 map.mem_start = ints[3];
641 map.mem_end = ints[4];
643 /* Add new entry to the list */
644 return netdev_boot_setup_add(str, &map);
647 __setup("netdev=", netdev_boot_setup);
649 /*******************************************************************************
651 Device Interface Subroutines
653 *******************************************************************************/
656 * __dev_get_by_name - find a device by its name
657 * @net: the applicable net namespace
658 * @name: name to find
660 * Find an interface by name. Must be called under RTNL semaphore
661 * or @dev_base_lock. If the name is found a pointer to the device
662 * is returned. If the name is not found then %NULL is returned. The
663 * reference counters are not incremented so the caller must be
664 * careful with locks.
667 struct net_device *__dev_get_by_name(struct net *net, const char *name)
669 struct net_device *dev;
670 struct hlist_head *head = dev_name_hash(net, name);
672 hlist_for_each_entry(dev, head, name_hlist)
673 if (!strncmp(dev->name, name, IFNAMSIZ))
678 EXPORT_SYMBOL(__dev_get_by_name);
681 * dev_get_by_name_rcu - find a device by its name
682 * @net: the applicable net namespace
683 * @name: name to find
685 * Find an interface by name.
686 * If the name is found a pointer to the device is returned.
687 * If the name is not found then %NULL is returned.
688 * The reference counters are not incremented so the caller must be
689 * careful with locks. The caller must hold RCU lock.
692 struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
694 struct net_device *dev;
695 struct hlist_head *head = dev_name_hash(net, name);
697 hlist_for_each_entry_rcu(dev, head, name_hlist)
698 if (!strncmp(dev->name, name, IFNAMSIZ))
703 EXPORT_SYMBOL(dev_get_by_name_rcu);
706 * dev_get_by_name - find a device by its name
707 * @net: the applicable net namespace
708 * @name: name to find
710 * Find an interface by name. This can be called from any
711 * context and does its own locking. The returned handle has
712 * the usage count incremented and the caller must use dev_put() to
713 * release it when it is no longer needed. %NULL is returned if no
714 * matching device is found.
717 struct net_device *dev_get_by_name(struct net *net, const char *name)
719 struct net_device *dev;
722 dev = dev_get_by_name_rcu(net, name);
728 EXPORT_SYMBOL(dev_get_by_name);
731 * __dev_get_by_index - find a device by its ifindex
732 * @net: the applicable net namespace
733 * @ifindex: index of device
735 * Search for an interface by index. Returns %NULL if the device
736 * is not found or a pointer to the device. The device has not
737 * had its reference counter increased so the caller must be careful
738 * about locking. The caller must hold either the RTNL semaphore
742 struct net_device *__dev_get_by_index(struct net *net, int ifindex)
744 struct net_device *dev;
745 struct hlist_head *head = dev_index_hash(net, ifindex);
747 hlist_for_each_entry(dev, head, index_hlist)
748 if (dev->ifindex == ifindex)
753 EXPORT_SYMBOL(__dev_get_by_index);
756 * dev_get_by_index_rcu - find a device by its ifindex
757 * @net: the applicable net namespace
758 * @ifindex: index of device
760 * Search for an interface by index. Returns %NULL if the device
761 * is not found or a pointer to the device. The device has not
762 * had its reference counter increased so the caller must be careful
763 * about locking. The caller must hold RCU lock.
766 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
768 struct net_device *dev;
769 struct hlist_head *head = dev_index_hash(net, ifindex);
771 hlist_for_each_entry_rcu(dev, head, index_hlist)
772 if (dev->ifindex == ifindex)
777 EXPORT_SYMBOL(dev_get_by_index_rcu);
781 * dev_get_by_index - find a device by its ifindex
782 * @net: the applicable net namespace
783 * @ifindex: index of device
785 * Search for an interface by index. Returns NULL if the device
786 * is not found or a pointer to the device. The device returned has
787 * had a reference added and the pointer is safe until the user calls
788 * dev_put to indicate they have finished with it.
791 struct net_device *dev_get_by_index(struct net *net, int ifindex)
793 struct net_device *dev;
796 dev = dev_get_by_index_rcu(net, ifindex);
802 EXPORT_SYMBOL(dev_get_by_index);
805 * netdev_get_name - get a netdevice name, knowing its ifindex.
806 * @net: network namespace
807 * @name: a pointer to the buffer where the name will be stored.
808 * @ifindex: the ifindex of the interface to get the name from.
810 * The use of raw_seqcount_begin() and cond_resched() before
811 * retrying is required as we want to give the writers a chance
812 * to complete when CONFIG_PREEMPT is not set.
814 int netdev_get_name(struct net *net, char *name, int ifindex)
816 struct net_device *dev;
820 seq = raw_seqcount_begin(&devnet_rename_seq);
822 dev = dev_get_by_index_rcu(net, ifindex);
828 strcpy(name, dev->name);
830 if (read_seqcount_retry(&devnet_rename_seq, seq)) {
839 * dev_getbyhwaddr_rcu - find a device by its hardware address
840 * @net: the applicable net namespace
841 * @type: media type of device
842 * @ha: hardware address
844 * Search for an interface by MAC address. Returns NULL if the device
845 * is not found or a pointer to the device.
846 * The caller must hold RCU or RTNL.
847 * The returned device has not had its ref count increased
848 * and the caller must therefore be careful about locking
852 struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
855 struct net_device *dev;
857 for_each_netdev_rcu(net, dev)
858 if (dev->type == type &&
859 !memcmp(dev->dev_addr, ha, dev->addr_len))
864 EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
866 struct net_device *__dev_getfirstbyhwtype(struct net *net, unsigned short type)
868 struct net_device *dev;
871 for_each_netdev(net, dev)
872 if (dev->type == type)
877 EXPORT_SYMBOL(__dev_getfirstbyhwtype);
879 struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
881 struct net_device *dev, *ret = NULL;
884 for_each_netdev_rcu(net, dev)
885 if (dev->type == type) {
893 EXPORT_SYMBOL(dev_getfirstbyhwtype);
896 * dev_get_by_flags_rcu - find any device with given flags
897 * @net: the applicable net namespace
898 * @if_flags: IFF_* values
899 * @mask: bitmask of bits in if_flags to check
901 * Search for any interface with the given flags. Returns NULL if a device
902 * is not found or a pointer to the device. Must be called inside
903 * rcu_read_lock(), and result refcount is unchanged.
906 struct net_device *dev_get_by_flags_rcu(struct net *net, unsigned short if_flags,
909 struct net_device *dev, *ret;
912 for_each_netdev_rcu(net, dev) {
913 if (((dev->flags ^ if_flags) & mask) == 0) {
920 EXPORT_SYMBOL(dev_get_by_flags_rcu);
923 * dev_valid_name - check if name is okay for network device
926 * Network device names need to be valid file names to
927 * to allow sysfs to work. We also disallow any kind of
930 bool dev_valid_name(const char *name)
934 if (strlen(name) >= IFNAMSIZ)
936 if (!strcmp(name, ".") || !strcmp(name, ".."))
940 if (*name == '/' || isspace(*name))
946 EXPORT_SYMBOL(dev_valid_name);
949 * __dev_alloc_name - allocate a name for a device
950 * @net: network namespace to allocate the device name in
951 * @name: name format string
952 * @buf: scratch buffer and result name string
954 * Passed a format string - eg "lt%d" it will try and find a suitable
955 * id. It scans list of devices to build up a free map, then chooses
956 * the first empty slot. The caller must hold the dev_base or rtnl lock
957 * while allocating the name and adding the device in order to avoid
959 * Limited to bits_per_byte * page size devices (ie 32K on most platforms).
960 * Returns the number of the unit assigned or a negative errno code.
963 static int __dev_alloc_name(struct net *net, const char *name, char *buf)
967 const int max_netdevices = 8*PAGE_SIZE;
968 unsigned long *inuse;
969 struct net_device *d;
971 p = strnchr(name, IFNAMSIZ-1, '%');
974 * Verify the string as this thing may have come from
975 * the user. There must be either one "%d" and no other "%"
978 if (p[1] != 'd' || strchr(p + 2, '%'))
981 /* Use one page as a bit array of possible slots */
982 inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
986 for_each_netdev(net, d) {
987 if (!sscanf(d->name, name, &i))
989 if (i < 0 || i >= max_netdevices)
992 /* avoid cases where sscanf is not exact inverse of printf */
993 snprintf(buf, IFNAMSIZ, name, i);
994 if (!strncmp(buf, d->name, IFNAMSIZ))
998 i = find_first_zero_bit(inuse, max_netdevices);
999 free_page((unsigned long) inuse);
1003 snprintf(buf, IFNAMSIZ, name, i);
1004 if (!__dev_get_by_name(net, buf))
1007 /* It is possible to run out of possible slots
1008 * when the name is long and there isn't enough space left
1009 * for the digits, or if all bits are used.
1015 * dev_alloc_name - allocate a name for a device
1017 * @name: name format string
1019 * Passed a format string - eg "lt%d" it will try and find a suitable
1020 * id. It scans list of devices to build up a free map, then chooses
1021 * the first empty slot. The caller must hold the dev_base or rtnl lock
1022 * while allocating the name and adding the device in order to avoid
1024 * Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1025 * Returns the number of the unit assigned or a negative errno code.
1028 int dev_alloc_name(struct net_device *dev, const char *name)
1034 BUG_ON(!dev_net(dev));
1036 ret = __dev_alloc_name(net, name, buf);
1038 strlcpy(dev->name, buf, IFNAMSIZ);
1041 EXPORT_SYMBOL(dev_alloc_name);
1043 static int dev_alloc_name_ns(struct net *net,
1044 struct net_device *dev,
1050 ret = __dev_alloc_name(net, name, buf);
1052 strlcpy(dev->name, buf, IFNAMSIZ);
1056 static int dev_get_valid_name(struct net *net,
1057 struct net_device *dev,
1062 if (!dev_valid_name(name))
1065 if (strchr(name, '%'))
1066 return dev_alloc_name_ns(net, dev, name);
1067 else if (__dev_get_by_name(net, name))
1069 else if (dev->name != name)
1070 strlcpy(dev->name, name, IFNAMSIZ);
1076 * dev_change_name - change name of a device
1078 * @newname: name (or format string) must be at least IFNAMSIZ
1080 * Change name of a device, can pass format strings "eth%d".
1083 int dev_change_name(struct net_device *dev, const char *newname)
1085 char oldname[IFNAMSIZ];
1091 BUG_ON(!dev_net(dev));
1094 if (dev->flags & IFF_UP)
1097 write_seqcount_begin(&devnet_rename_seq);
1099 if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
1100 write_seqcount_end(&devnet_rename_seq);
1104 memcpy(oldname, dev->name, IFNAMSIZ);
1106 err = dev_get_valid_name(net, dev, newname);
1108 write_seqcount_end(&devnet_rename_seq);
1113 ret = device_rename(&dev->dev, dev->name);
1115 memcpy(dev->name, oldname, IFNAMSIZ);
1116 write_seqcount_end(&devnet_rename_seq);
1120 write_seqcount_end(&devnet_rename_seq);
1122 netdev_adjacent_rename_links(dev, oldname);
1124 write_lock_bh(&dev_base_lock);
1125 hlist_del_rcu(&dev->name_hlist);
1126 write_unlock_bh(&dev_base_lock);
1130 write_lock_bh(&dev_base_lock);
1131 hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
1132 write_unlock_bh(&dev_base_lock);
1134 ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1135 ret = notifier_to_errno(ret);
1138 /* err >= 0 after dev_alloc_name() or stores the first errno */
1141 write_seqcount_begin(&devnet_rename_seq);
1142 memcpy(dev->name, oldname, IFNAMSIZ);
1143 memcpy(oldname, newname, IFNAMSIZ);
1146 pr_err("%s: name change rollback failed: %d\n",
1155 * dev_set_alias - change ifalias of a device
1157 * @alias: name up to IFALIASZ
1158 * @len: limit of bytes to copy from info
1160 * Set ifalias for a device,
1162 int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
1168 if (len >= IFALIASZ)
1172 kfree(dev->ifalias);
1173 dev->ifalias = NULL;
1177 new_ifalias = krealloc(dev->ifalias, len + 1, GFP_KERNEL);
1180 dev->ifalias = new_ifalias;
1182 strlcpy(dev->ifalias, alias, len+1);
1188 * netdev_features_change - device changes features
1189 * @dev: device to cause notification
1191 * Called to indicate a device has changed features.
1193 void netdev_features_change(struct net_device *dev)
1195 call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1197 EXPORT_SYMBOL(netdev_features_change);
1200 * netdev_state_change - device changes state
1201 * @dev: device to cause notification
1203 * Called to indicate a device has changed state. This function calls
1204 * the notifier chains for netdev_chain and sends a NEWLINK message
1205 * to the routing socket.
1207 void netdev_state_change(struct net_device *dev)
1209 if (dev->flags & IFF_UP) {
1210 call_netdevice_notifiers(NETDEV_CHANGE, dev);
1211 rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL);
1214 EXPORT_SYMBOL(netdev_state_change);
1217 * netdev_notify_peers - notify network peers about existence of @dev
1218 * @dev: network device
1220 * Generate traffic such that interested network peers are aware of
1221 * @dev, such as by generating a gratuitous ARP. This may be used when
1222 * a device wants to inform the rest of the network about some sort of
1223 * reconfiguration such as a failover event or virtual machine
1226 void netdev_notify_peers(struct net_device *dev)
1229 call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
1232 EXPORT_SYMBOL(netdev_notify_peers);
1234 static int __dev_open(struct net_device *dev)
1236 const struct net_device_ops *ops = dev->netdev_ops;
1241 if (!netif_device_present(dev))
1244 /* Block netpoll from trying to do any rx path servicing.
1245 * If we don't do this there is a chance ndo_poll_controller
1246 * or ndo_poll may be running while we open the device
1248 netpoll_poll_disable(dev);
1250 ret = call_netdevice_notifiers(NETDEV_PRE_UP, dev);
1251 ret = notifier_to_errno(ret);
1255 set_bit(__LINK_STATE_START, &dev->state);
1257 if (ops->ndo_validate_addr)
1258 ret = ops->ndo_validate_addr(dev);
1260 if (!ret && ops->ndo_open)
1261 ret = ops->ndo_open(dev);
1263 netpoll_poll_enable(dev);
1266 clear_bit(__LINK_STATE_START, &dev->state);
1268 dev->flags |= IFF_UP;
1269 net_dmaengine_get();
1270 dev_set_rx_mode(dev);
1272 add_device_randomness(dev->dev_addr, dev->addr_len);
1279 * dev_open - prepare an interface for use.
1280 * @dev: device to open
1282 * Takes a device from down to up state. The device's private open
1283 * function is invoked and then the multicast lists are loaded. Finally
1284 * the device is moved into the up state and a %NETDEV_UP message is
1285 * sent to the netdev notifier chain.
1287 * Calling this function on an active interface is a nop. On a failure
1288 * a negative errno code is returned.
1290 int dev_open(struct net_device *dev)
1294 if (dev->flags & IFF_UP)
1297 ret = __dev_open(dev);
1301 rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
1302 call_netdevice_notifiers(NETDEV_UP, dev);
1306 EXPORT_SYMBOL(dev_open);
1308 static int __dev_close_many(struct list_head *head)
1310 struct net_device *dev;
1315 list_for_each_entry(dev, head, close_list) {
1316 /* Temporarily disable netpoll until the interface is down */
1317 netpoll_poll_disable(dev);
1319 call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
1321 clear_bit(__LINK_STATE_START, &dev->state);
1323 /* Synchronize to scheduled poll. We cannot touch poll list, it
1324 * can be even on different cpu. So just clear netif_running().
1326 * dev->stop() will invoke napi_disable() on all of it's
1327 * napi_struct instances on this device.
1329 smp_mb__after_clear_bit(); /* Commit netif_running(). */
1332 dev_deactivate_many(head);
1334 list_for_each_entry(dev, head, close_list) {
1335 const struct net_device_ops *ops = dev->netdev_ops;
1338 * Call the device specific close. This cannot fail.
1339 * Only if device is UP
1341 * We allow it to be called even after a DETACH hot-plug
1347 dev->flags &= ~IFF_UP;
1348 net_dmaengine_put();
1349 netpoll_poll_enable(dev);
1355 static int __dev_close(struct net_device *dev)
1360 list_add(&dev->close_list, &single);
1361 retval = __dev_close_many(&single);
1367 static int dev_close_many(struct list_head *head)
1369 struct net_device *dev, *tmp;
1371 /* Remove the devices that don't need to be closed */
1372 list_for_each_entry_safe(dev, tmp, head, close_list)
1373 if (!(dev->flags & IFF_UP))
1374 list_del_init(&dev->close_list);
1376 __dev_close_many(head);
1378 list_for_each_entry_safe(dev, tmp, head, close_list) {
1379 rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
1380 call_netdevice_notifiers(NETDEV_DOWN, dev);
1381 list_del_init(&dev->close_list);
1388 * dev_close - shutdown an interface.
1389 * @dev: device to shutdown
1391 * This function moves an active device into down state. A
1392 * %NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
1393 * is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
1396 int dev_close(struct net_device *dev)
1398 if (dev->flags & IFF_UP) {
1401 list_add(&dev->close_list, &single);
1402 dev_close_many(&single);
1407 EXPORT_SYMBOL(dev_close);
1411 * dev_disable_lro - disable Large Receive Offload on a device
1414 * Disable Large Receive Offload (LRO) on a net device. Must be
1415 * called under RTNL. This is needed if received packets may be
1416 * forwarded to another interface.
1418 void dev_disable_lro(struct net_device *dev)
1421 * If we're trying to disable lro on a vlan device
1422 * use the underlying physical device instead
1424 if (is_vlan_dev(dev))
1425 dev = vlan_dev_real_dev(dev);
1427 /* the same for macvlan devices */
1428 if (netif_is_macvlan(dev))
1429 dev = macvlan_dev_real_dev(dev);
1431 dev->wanted_features &= ~NETIF_F_LRO;
1432 netdev_update_features(dev);
1434 if (unlikely(dev->features & NETIF_F_LRO))
1435 netdev_WARN(dev, "failed to disable LRO!\n");
1437 EXPORT_SYMBOL(dev_disable_lro);
1439 static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val,
1440 struct net_device *dev)
1442 struct netdev_notifier_info info;
1444 netdev_notifier_info_init(&info, dev);
1445 return nb->notifier_call(nb, val, &info);
1448 static int dev_boot_phase = 1;
1451 * register_netdevice_notifier - register a network notifier block
1454 * Register a notifier to be called when network device events occur.
1455 * The notifier passed is linked into the kernel structures and must
1456 * not be reused until it has been unregistered. A negative errno code
1457 * is returned on a failure.
1459 * When registered all registration and up events are replayed
1460 * to the new notifier to allow device to have a race free
1461 * view of the network device list.
1464 int register_netdevice_notifier(struct notifier_block *nb)
1466 struct net_device *dev;
1467 struct net_device *last;
1472 err = raw_notifier_chain_register(&netdev_chain, nb);
1478 for_each_netdev(net, dev) {
1479 err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev);
1480 err = notifier_to_errno(err);
1484 if (!(dev->flags & IFF_UP))
1487 call_netdevice_notifier(nb, NETDEV_UP, dev);
1498 for_each_netdev(net, dev) {
1502 if (dev->flags & IFF_UP) {
1503 call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
1505 call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1507 call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1512 raw_notifier_chain_unregister(&netdev_chain, nb);
1515 EXPORT_SYMBOL(register_netdevice_notifier);
1518 * unregister_netdevice_notifier - unregister a network notifier block
1521 * Unregister a notifier previously registered by
1522 * register_netdevice_notifier(). The notifier is unlinked into the
1523 * kernel structures and may then be reused. A negative errno code
1524 * is returned on a failure.
1526 * After unregistering unregister and down device events are synthesized
1527 * for all devices on the device list to the removed notifier to remove
1528 * the need for special case cleanup code.
1531 int unregister_netdevice_notifier(struct notifier_block *nb)
1533 struct net_device *dev;
1538 err = raw_notifier_chain_unregister(&netdev_chain, nb);
1543 for_each_netdev(net, dev) {
1544 if (dev->flags & IFF_UP) {
1545 call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
1547 call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1549 call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1556 EXPORT_SYMBOL(unregister_netdevice_notifier);
1559 * call_netdevice_notifiers_info - call all network notifier blocks
1560 * @val: value passed unmodified to notifier function
1561 * @dev: net_device pointer passed unmodified to notifier function
1562 * @info: notifier information data
1564 * Call all network notifier blocks. Parameters and return value
1565 * are as for raw_notifier_call_chain().
1568 static int call_netdevice_notifiers_info(unsigned long val,
1569 struct net_device *dev,
1570 struct netdev_notifier_info *info)
1573 netdev_notifier_info_init(info, dev);
1574 return raw_notifier_call_chain(&netdev_chain, val, info);
1578 * call_netdevice_notifiers - call all network notifier blocks
1579 * @val: value passed unmodified to notifier function
1580 * @dev: net_device pointer passed unmodified to notifier function
1582 * Call all network notifier blocks. Parameters and return value
1583 * are as for raw_notifier_call_chain().
1586 int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
1588 struct netdev_notifier_info info;
1590 return call_netdevice_notifiers_info(val, dev, &info);
1592 EXPORT_SYMBOL(call_netdevice_notifiers);
1594 static struct static_key netstamp_needed __read_mostly;
1595 #ifdef HAVE_JUMP_LABEL
1596 /* We are not allowed to call static_key_slow_dec() from irq context
1597 * If net_disable_timestamp() is called from irq context, defer the
1598 * static_key_slow_dec() calls.
1600 static atomic_t netstamp_needed_deferred;
1603 void net_enable_timestamp(void)
1605 #ifdef HAVE_JUMP_LABEL
1606 int deferred = atomic_xchg(&netstamp_needed_deferred, 0);
1610 static_key_slow_dec(&netstamp_needed);
1614 static_key_slow_inc(&netstamp_needed);
1616 EXPORT_SYMBOL(net_enable_timestamp);
1618 void net_disable_timestamp(void)
1620 #ifdef HAVE_JUMP_LABEL
1621 if (in_interrupt()) {
1622 atomic_inc(&netstamp_needed_deferred);
1626 static_key_slow_dec(&netstamp_needed);
1628 EXPORT_SYMBOL(net_disable_timestamp);
1630 static inline void net_timestamp_set(struct sk_buff *skb)
1632 skb->tstamp.tv64 = 0;
1633 if (static_key_false(&netstamp_needed))
1634 __net_timestamp(skb);
1637 #define net_timestamp_check(COND, SKB) \
1638 if (static_key_false(&netstamp_needed)) { \
1639 if ((COND) && !(SKB)->tstamp.tv64) \
1640 __net_timestamp(SKB); \
1643 bool is_skb_forwardable(struct net_device *dev, struct sk_buff *skb)
1647 if (!(dev->flags & IFF_UP))
1650 len = dev->mtu + dev->hard_header_len + VLAN_HLEN;
1651 if (skb->len <= len)
1654 /* if TSO is enabled, we don't care about the length as the packet
1655 * could be forwarded without being segmented before
1657 if (skb_is_gso(skb))
1662 EXPORT_SYMBOL_GPL(is_skb_forwardable);
1665 * dev_forward_skb - loopback an skb to another netif
1667 * @dev: destination network device
1668 * @skb: buffer to forward
1671 * NET_RX_SUCCESS (no congestion)
1672 * NET_RX_DROP (packet was dropped, but freed)
1674 * dev_forward_skb can be used for injecting an skb from the
1675 * start_xmit function of one device into the receive queue
1676 * of another device.
1678 * The receiving device may be in another namespace, so
1679 * we have to clear all information in the skb that could
1680 * impact namespace isolation.
1682 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
1684 if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) {
1685 if (skb_copy_ubufs(skb, GFP_ATOMIC)) {
1686 atomic_long_inc(&dev->rx_dropped);
1692 if (unlikely(!is_skb_forwardable(dev, skb))) {
1693 atomic_long_inc(&dev->rx_dropped);
1698 skb_scrub_packet(skb, true);
1699 skb->protocol = eth_type_trans(skb, dev);
1701 return netif_rx_internal(skb);
1703 EXPORT_SYMBOL_GPL(dev_forward_skb);
1705 static inline int deliver_skb(struct sk_buff *skb,
1706 struct packet_type *pt_prev,
1707 struct net_device *orig_dev)
1709 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
1711 atomic_inc(&skb->users);
1712 return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
1715 static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
1717 if (!ptype->af_packet_priv || !skb->sk)
1720 if (ptype->id_match)
1721 return ptype->id_match(ptype, skb->sk);
1722 else if ((struct sock *)ptype->af_packet_priv == skb->sk)
1729 * Support routine. Sends outgoing frames to any network
1730 * taps currently in use.
1733 static void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
1735 struct packet_type *ptype;
1736 struct sk_buff *skb2 = NULL;
1737 struct packet_type *pt_prev = NULL;
1740 list_for_each_entry_rcu(ptype, &ptype_all, list) {
1741 /* Never send packets back to the socket
1742 * they originated from - MvS (miquels@drinkel.ow.org)
1744 if ((ptype->dev == dev || !ptype->dev) &&
1745 (!skb_loop_sk(ptype, skb))) {
1747 deliver_skb(skb2, pt_prev, skb->dev);
1752 skb2 = skb_clone(skb, GFP_ATOMIC);
1756 net_timestamp_set(skb2);
1758 /* skb->nh should be correctly
1759 set by sender, so that the second statement is
1760 just protection against buggy protocols.
1762 skb_reset_mac_header(skb2);
1764 if (skb_network_header(skb2) < skb2->data ||
1765 skb_network_header(skb2) > skb_tail_pointer(skb2)) {
1766 net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
1767 ntohs(skb2->protocol),
1769 skb_reset_network_header(skb2);
1772 skb2->transport_header = skb2->network_header;
1773 skb2->pkt_type = PACKET_OUTGOING;
1778 pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
1783 * netif_setup_tc - Handle tc mappings on real_num_tx_queues change
1784 * @dev: Network device
1785 * @txq: number of queues available
1787 * If real_num_tx_queues is changed the tc mappings may no longer be
1788 * valid. To resolve this verify the tc mapping remains valid and if
1789 * not NULL the mapping. With no priorities mapping to this
1790 * offset/count pair it will no longer be used. In the worst case TC0
1791 * is invalid nothing can be done so disable priority mappings. If is
1792 * expected that drivers will fix this mapping if they can before
1793 * calling netif_set_real_num_tx_queues.
1795 static void netif_setup_tc(struct net_device *dev, unsigned int txq)
1798 struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
1800 /* If TC0 is invalidated disable TC mapping */
1801 if (tc->offset + tc->count > txq) {
1802 pr_warn("Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
1807 /* Invalidated prio to tc mappings set to TC0 */
1808 for (i = 1; i < TC_BITMASK + 1; i++) {
1809 int q = netdev_get_prio_tc_map(dev, i);
1811 tc = &dev->tc_to_txq[q];
1812 if (tc->offset + tc->count > txq) {
1813 pr_warn("Number of in use tx queues changed. Priority %i to tc mapping %i is no longer valid. Setting map to 0\n",
1815 netdev_set_prio_tc_map(dev, i, 0);
1821 static DEFINE_MUTEX(xps_map_mutex);
1822 #define xmap_dereference(P) \
1823 rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
1825 static struct xps_map *remove_xps_queue(struct xps_dev_maps *dev_maps,
1828 struct xps_map *map = NULL;
1832 map = xmap_dereference(dev_maps->cpu_map[cpu]);
1834 for (pos = 0; map && pos < map->len; pos++) {
1835 if (map->queues[pos] == index) {
1837 map->queues[pos] = map->queues[--map->len];
1839 RCU_INIT_POINTER(dev_maps->cpu_map[cpu], NULL);
1840 kfree_rcu(map, rcu);
1850 static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
1852 struct xps_dev_maps *dev_maps;
1854 bool active = false;
1856 mutex_lock(&xps_map_mutex);
1857 dev_maps = xmap_dereference(dev->xps_maps);
1862 for_each_possible_cpu(cpu) {
1863 for (i = index; i < dev->num_tx_queues; i++) {
1864 if (!remove_xps_queue(dev_maps, cpu, i))
1867 if (i == dev->num_tx_queues)
1872 RCU_INIT_POINTER(dev->xps_maps, NULL);
1873 kfree_rcu(dev_maps, rcu);
1876 for (i = index; i < dev->num_tx_queues; i++)
1877 netdev_queue_numa_node_write(netdev_get_tx_queue(dev, i),
1881 mutex_unlock(&xps_map_mutex);
1884 static struct xps_map *expand_xps_map(struct xps_map *map,
1887 struct xps_map *new_map;
1888 int alloc_len = XPS_MIN_MAP_ALLOC;
1891 for (pos = 0; map && pos < map->len; pos++) {
1892 if (map->queues[pos] != index)
1897 /* Need to add queue to this CPU's existing map */
1899 if (pos < map->alloc_len)
1902 alloc_len = map->alloc_len * 2;
1905 /* Need to allocate new map to store queue on this CPU's map */
1906 new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len), GFP_KERNEL,
1911 for (i = 0; i < pos; i++)
1912 new_map->queues[i] = map->queues[i];
1913 new_map->alloc_len = alloc_len;
1919 int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask,
1922 struct xps_dev_maps *dev_maps, *new_dev_maps = NULL;
1923 struct xps_map *map, *new_map;
1924 int maps_sz = max_t(unsigned int, XPS_DEV_MAPS_SIZE, L1_CACHE_BYTES);
1925 int cpu, numa_node_id = -2;
1926 bool active = false;
1928 mutex_lock(&xps_map_mutex);
1930 dev_maps = xmap_dereference(dev->xps_maps);
1932 /* allocate memory for queue storage */
1933 for_each_online_cpu(cpu) {
1934 if (!cpumask_test_cpu(cpu, mask))
1938 new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
1939 if (!new_dev_maps) {
1940 mutex_unlock(&xps_map_mutex);
1944 map = dev_maps ? xmap_dereference(dev_maps->cpu_map[cpu]) :
1947 map = expand_xps_map(map, cpu, index);
1951 RCU_INIT_POINTER(new_dev_maps->cpu_map[cpu], map);
1955 goto out_no_new_maps;
1957 for_each_possible_cpu(cpu) {
1958 if (cpumask_test_cpu(cpu, mask) && cpu_online(cpu)) {
1959 /* add queue to CPU maps */
1962 map = xmap_dereference(new_dev_maps->cpu_map[cpu]);
1963 while ((pos < map->len) && (map->queues[pos] != index))
1966 if (pos == map->len)
1967 map->queues[map->len++] = index;
1969 if (numa_node_id == -2)
1970 numa_node_id = cpu_to_node(cpu);
1971 else if (numa_node_id != cpu_to_node(cpu))
1974 } else if (dev_maps) {
1975 /* fill in the new device map from the old device map */
1976 map = xmap_dereference(dev_maps->cpu_map[cpu]);
1977 RCU_INIT_POINTER(new_dev_maps->cpu_map[cpu], map);
1982 rcu_assign_pointer(dev->xps_maps, new_dev_maps);
1984 /* Cleanup old maps */
1986 for_each_possible_cpu(cpu) {
1987 new_map = xmap_dereference(new_dev_maps->cpu_map[cpu]);
1988 map = xmap_dereference(dev_maps->cpu_map[cpu]);
1989 if (map && map != new_map)
1990 kfree_rcu(map, rcu);
1993 kfree_rcu(dev_maps, rcu);
1996 dev_maps = new_dev_maps;
2000 /* update Tx queue numa node */
2001 netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
2002 (numa_node_id >= 0) ? numa_node_id :
2008 /* removes queue from unused CPUs */
2009 for_each_possible_cpu(cpu) {
2010 if (cpumask_test_cpu(cpu, mask) && cpu_online(cpu))
2013 if (remove_xps_queue(dev_maps, cpu, index))
2017 /* free map if not active */
2019 RCU_INIT_POINTER(dev->xps_maps, NULL);
2020 kfree_rcu(dev_maps, rcu);
2024 mutex_unlock(&xps_map_mutex);
2028 /* remove any maps that we added */
2029 for_each_possible_cpu(cpu) {
2030 new_map = xmap_dereference(new_dev_maps->cpu_map[cpu]);
2031 map = dev_maps ? xmap_dereference(dev_maps->cpu_map[cpu]) :
2033 if (new_map && new_map != map)
2037 mutex_unlock(&xps_map_mutex);
2039 kfree(new_dev_maps);
2042 EXPORT_SYMBOL(netif_set_xps_queue);
2046 * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
2047 * greater then real_num_tx_queues stale skbs on the qdisc must be flushed.
2049 int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
2053 if (txq < 1 || txq > dev->num_tx_queues)
2056 if (dev->reg_state == NETREG_REGISTERED ||
2057 dev->reg_state == NETREG_UNREGISTERING) {
2060 rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
2066 netif_setup_tc(dev, txq);
2068 if (txq < dev->real_num_tx_queues) {
2069 qdisc_reset_all_tx_gt(dev, txq);
2071 netif_reset_xps_queues_gt(dev, txq);
2076 dev->real_num_tx_queues = txq;
2079 EXPORT_SYMBOL(netif_set_real_num_tx_queues);
2083 * netif_set_real_num_rx_queues - set actual number of RX queues used
2084 * @dev: Network device
2085 * @rxq: Actual number of RX queues
2087 * This must be called either with the rtnl_lock held or before
2088 * registration of the net device. Returns 0 on success, or a
2089 * negative error code. If called before registration, it always
2092 int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
2096 if (rxq < 1 || rxq > dev->num_rx_queues)
2099 if (dev->reg_state == NETREG_REGISTERED) {
2102 rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
2108 dev->real_num_rx_queues = rxq;
2111 EXPORT_SYMBOL(netif_set_real_num_rx_queues);
2115 * netif_get_num_default_rss_queues - default number of RSS queues
2117 * This routine should set an upper limit on the number of RSS queues
2118 * used by default by multiqueue devices.
2120 int netif_get_num_default_rss_queues(void)
2122 return min_t(int, DEFAULT_MAX_NUM_RSS_QUEUES, num_online_cpus());
2124 EXPORT_SYMBOL(netif_get_num_default_rss_queues);
2126 static inline void __netif_reschedule(struct Qdisc *q)
2128 struct softnet_data *sd;
2129 unsigned long flags;
2131 local_irq_save(flags);
2132 sd = &__get_cpu_var(softnet_data);
2133 q->next_sched = NULL;
2134 *sd->output_queue_tailp = q;
2135 sd->output_queue_tailp = &q->next_sched;
2136 raise_softirq_irqoff(NET_TX_SOFTIRQ);
2137 local_irq_restore(flags);
2140 void __netif_schedule(struct Qdisc *q)
2142 if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
2143 __netif_reschedule(q);
2145 EXPORT_SYMBOL(__netif_schedule);
2147 struct dev_kfree_skb_cb {
2148 enum skb_free_reason reason;
2151 static struct dev_kfree_skb_cb *get_kfree_skb_cb(const struct sk_buff *skb)
2153 return (struct dev_kfree_skb_cb *)skb->cb;
2156 void __dev_kfree_skb_irq(struct sk_buff *skb, enum skb_free_reason reason)
2158 unsigned long flags;
2160 if (likely(atomic_read(&skb->users) == 1)) {
2162 atomic_set(&skb->users, 0);
2163 } else if (likely(!atomic_dec_and_test(&skb->users))) {
2166 get_kfree_skb_cb(skb)->reason = reason;
2167 local_irq_save(flags);
2168 skb->next = __this_cpu_read(softnet_data.completion_queue);
2169 __this_cpu_write(softnet_data.completion_queue, skb);
2170 raise_softirq_irqoff(NET_TX_SOFTIRQ);
2171 local_irq_restore(flags);
2173 EXPORT_SYMBOL(__dev_kfree_skb_irq);
2175 void __dev_kfree_skb_any(struct sk_buff *skb, enum skb_free_reason reason)
2177 if (in_irq() || irqs_disabled())
2178 __dev_kfree_skb_irq(skb, reason);
2182 EXPORT_SYMBOL(__dev_kfree_skb_any);
2186 * netif_device_detach - mark device as removed
2187 * @dev: network device
2189 * Mark device as removed from system and therefore no longer available.
2191 void netif_device_detach(struct net_device *dev)
2193 if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
2194 netif_running(dev)) {
2195 netif_tx_stop_all_queues(dev);
2198 EXPORT_SYMBOL(netif_device_detach);
2201 * netif_device_attach - mark device as attached
2202 * @dev: network device
2204 * Mark device as attached from system and restart if needed.
2206 void netif_device_attach(struct net_device *dev)
2208 if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
2209 netif_running(dev)) {
2210 netif_tx_wake_all_queues(dev);
2211 __netdev_watchdog_up(dev);
2214 EXPORT_SYMBOL(netif_device_attach);
2216 static void skb_warn_bad_offload(const struct sk_buff *skb)
2218 static const netdev_features_t null_features = 0;
2219 struct net_device *dev = skb->dev;
2220 const char *driver = "";
2222 if (!net_ratelimit())
2225 if (dev && dev->dev.parent)
2226 driver = dev_driver_string(dev->dev.parent);
2228 WARN(1, "%s: caps=(%pNF, %pNF) len=%d data_len=%d gso_size=%d "
2229 "gso_type=%d ip_summed=%d\n",
2230 driver, dev ? &dev->features : &null_features,
2231 skb->sk ? &skb->sk->sk_route_caps : &null_features,
2232 skb->len, skb->data_len, skb_shinfo(skb)->gso_size,
2233 skb_shinfo(skb)->gso_type, skb->ip_summed);
2237 * Invalidate hardware checksum when packet is to be mangled, and
2238 * complete checksum manually on outgoing path.
2240 int skb_checksum_help(struct sk_buff *skb)
2243 int ret = 0, offset;
2245 if (skb->ip_summed == CHECKSUM_COMPLETE)
2246 goto out_set_summed;
2248 if (unlikely(skb_shinfo(skb)->gso_size)) {
2249 skb_warn_bad_offload(skb);
2253 /* Before computing a checksum, we should make sure no frag could
2254 * be modified by an external entity : checksum could be wrong.
2256 if (skb_has_shared_frag(skb)) {
2257 ret = __skb_linearize(skb);
2262 offset = skb_checksum_start_offset(skb);
2263 BUG_ON(offset >= skb_headlen(skb));
2264 csum = skb_checksum(skb, offset, skb->len - offset, 0);
2266 offset += skb->csum_offset;
2267 BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb));
2269 if (skb_cloned(skb) &&
2270 !skb_clone_writable(skb, offset + sizeof(__sum16))) {
2271 ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
2276 *(__sum16 *)(skb->data + offset) = csum_fold(csum);
2278 skb->ip_summed = CHECKSUM_NONE;
2282 EXPORT_SYMBOL(skb_checksum_help);
2284 __be16 skb_network_protocol(struct sk_buff *skb, int *depth)
2286 __be16 type = skb->protocol;
2287 int vlan_depth = ETH_HLEN;
2289 /* Tunnel gso handlers can set protocol to ethernet. */
2290 if (type == htons(ETH_P_TEB)) {
2293 if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
2296 eth = (struct ethhdr *)skb_mac_header(skb);
2297 type = eth->h_proto;
2300 while (type == htons(ETH_P_8021Q) || type == htons(ETH_P_8021AD)) {
2301 struct vlan_hdr *vh;
2303 if (unlikely(!pskb_may_pull(skb, vlan_depth + VLAN_HLEN)))
2306 vh = (struct vlan_hdr *)(skb->data + vlan_depth);
2307 type = vh->h_vlan_encapsulated_proto;
2308 vlan_depth += VLAN_HLEN;
2311 *depth = vlan_depth;
2317 * skb_mac_gso_segment - mac layer segmentation handler.
2318 * @skb: buffer to segment
2319 * @features: features for the output path (see dev->features)
2321 struct sk_buff *skb_mac_gso_segment(struct sk_buff *skb,
2322 netdev_features_t features)
2324 struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT);
2325 struct packet_offload *ptype;
2326 int vlan_depth = skb->mac_len;
2327 __be16 type = skb_network_protocol(skb, &vlan_depth);
2329 if (unlikely(!type))
2330 return ERR_PTR(-EINVAL);
2332 __skb_pull(skb, vlan_depth);
2335 list_for_each_entry_rcu(ptype, &offload_base, list) {
2336 if (ptype->type == type && ptype->callbacks.gso_segment) {
2337 if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
2340 err = ptype->callbacks.gso_send_check(skb);
2341 segs = ERR_PTR(err);
2342 if (err || skb_gso_ok(skb, features))
2344 __skb_push(skb, (skb->data -
2345 skb_network_header(skb)));
2347 segs = ptype->callbacks.gso_segment(skb, features);
2353 __skb_push(skb, skb->data - skb_mac_header(skb));
2357 EXPORT_SYMBOL(skb_mac_gso_segment);
2360 /* openvswitch calls this on rx path, so we need a different check.
2362 static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path)
2365 return skb->ip_summed != CHECKSUM_PARTIAL;
2367 return skb->ip_summed == CHECKSUM_NONE;
2371 * __skb_gso_segment - Perform segmentation on skb.
2372 * @skb: buffer to segment
2373 * @features: features for the output path (see dev->features)
2374 * @tx_path: whether it is called in TX path
2376 * This function segments the given skb and returns a list of segments.
2378 * It may return NULL if the skb requires no segmentation. This is
2379 * only possible when GSO is used for verifying header integrity.
2381 struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
2382 netdev_features_t features, bool tx_path)
2384 if (unlikely(skb_needs_check(skb, tx_path))) {
2387 skb_warn_bad_offload(skb);
2389 if (skb_header_cloned(skb) &&
2390 (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
2391 return ERR_PTR(err);
2394 SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb);
2395 SKB_GSO_CB(skb)->encap_level = 0;
2397 skb_reset_mac_header(skb);
2398 skb_reset_mac_len(skb);
2400 return skb_mac_gso_segment(skb, features);
2402 EXPORT_SYMBOL(__skb_gso_segment);
2404 /* Take action when hardware reception checksum errors are detected. */
2406 void netdev_rx_csum_fault(struct net_device *dev)
2408 if (net_ratelimit()) {
2409 pr_err("%s: hw csum failure\n", dev ? dev->name : "<unknown>");
2413 EXPORT_SYMBOL(netdev_rx_csum_fault);
2416 /* Actually, we should eliminate this check as soon as we know, that:
2417 * 1. IOMMU is present and allows to map all the memory.
2418 * 2. No high memory really exists on this machine.
2421 static int illegal_highdma(const struct net_device *dev, struct sk_buff *skb)
2423 #ifdef CONFIG_HIGHMEM
2425 if (!(dev->features & NETIF_F_HIGHDMA)) {
2426 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
2427 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
2428 if (PageHighMem(skb_frag_page(frag)))
2433 if (PCI_DMA_BUS_IS_PHYS) {
2434 struct device *pdev = dev->dev.parent;
2438 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
2439 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
2440 dma_addr_t addr = page_to_phys(skb_frag_page(frag));
2441 if (!pdev->dma_mask || addr + PAGE_SIZE - 1 > *pdev->dma_mask)
2450 void (*destructor)(struct sk_buff *skb);
2453 #define DEV_GSO_CB(skb) ((struct dev_gso_cb *)(skb)->cb)
2455 static void dev_gso_skb_destructor(struct sk_buff *skb)
2457 struct dev_gso_cb *cb;
2459 kfree_skb_list(skb->next);
2462 cb = DEV_GSO_CB(skb);
2464 cb->destructor(skb);
2468 * dev_gso_segment - Perform emulated hardware segmentation on skb.
2469 * @skb: buffer to segment
2470 * @features: device features as applicable to this skb
2472 * This function segments the given skb and stores the list of segments
2475 static int dev_gso_segment(struct sk_buff *skb, netdev_features_t features)
2477 struct sk_buff *segs;
2479 segs = skb_gso_segment(skb, features);
2481 /* Verifying header integrity only. */
2486 return PTR_ERR(segs);
2489 DEV_GSO_CB(skb)->destructor = skb->destructor;
2490 skb->destructor = dev_gso_skb_destructor;
2495 static netdev_features_t harmonize_features(struct sk_buff *skb,
2496 const struct net_device *dev,
2497 netdev_features_t features)
2501 if (skb->ip_summed != CHECKSUM_NONE &&
2502 !can_checksum_protocol(features, skb_network_protocol(skb, &tmp))) {
2503 features &= ~NETIF_F_ALL_CSUM;
2504 } else if (illegal_highdma(dev, skb)) {
2505 features &= ~NETIF_F_SG;
2511 netdev_features_t netif_skb_dev_features(struct sk_buff *skb,
2512 const struct net_device *dev)
2514 __be16 protocol = skb->protocol;
2515 netdev_features_t features = dev->features;
2517 if (skb_shinfo(skb)->gso_segs > dev->gso_max_segs)
2518 features &= ~NETIF_F_GSO_MASK;
2520 if (protocol == htons(ETH_P_8021Q) || protocol == htons(ETH_P_8021AD)) {
2521 struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
2522 protocol = veh->h_vlan_encapsulated_proto;
2523 } else if (!vlan_tx_tag_present(skb)) {
2524 return harmonize_features(skb, dev, features);
2527 features &= (dev->vlan_features | NETIF_F_HW_VLAN_CTAG_TX |
2528 NETIF_F_HW_VLAN_STAG_TX);
2530 if (protocol == htons(ETH_P_8021Q) || protocol == htons(ETH_P_8021AD))
2531 features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST |
2532 NETIF_F_GEN_CSUM | NETIF_F_HW_VLAN_CTAG_TX |
2533 NETIF_F_HW_VLAN_STAG_TX;
2535 return harmonize_features(skb, dev, features);
2537 EXPORT_SYMBOL(netif_skb_dev_features);
2539 int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
2540 struct netdev_queue *txq)
2542 const struct net_device_ops *ops = dev->netdev_ops;
2543 int rc = NETDEV_TX_OK;
2544 unsigned int skb_len;
2546 if (likely(!skb->next)) {
2547 netdev_features_t features;
2550 * If device doesn't need skb->dst, release it right now while
2551 * its hot in this cpu cache
2553 if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
2556 features = netif_skb_features(skb);
2558 if (vlan_tx_tag_present(skb) &&
2559 !vlan_hw_offload_capable(features, skb->vlan_proto)) {
2560 skb = __vlan_put_tag(skb, skb->vlan_proto,
2561 vlan_tx_tag_get(skb));
2568 /* If encapsulation offload request, verify we are testing
2569 * hardware encapsulation features instead of standard
2570 * features for the netdev
2572 if (skb->encapsulation)
2573 features &= dev->hw_enc_features;
2575 if (netif_needs_gso(skb, features)) {
2576 if (unlikely(dev_gso_segment(skb, features)))
2581 if (skb_needs_linearize(skb, features) &&
2582 __skb_linearize(skb))
2585 /* If packet is not checksummed and device does not
2586 * support checksumming for this protocol, complete
2587 * checksumming here.
2589 if (skb->ip_summed == CHECKSUM_PARTIAL) {
2590 if (skb->encapsulation)
2591 skb_set_inner_transport_header(skb,
2592 skb_checksum_start_offset(skb));
2594 skb_set_transport_header(skb,
2595 skb_checksum_start_offset(skb));
2596 if (!(features & NETIF_F_ALL_CSUM) &&
2597 skb_checksum_help(skb))
2602 if (!list_empty(&ptype_all))
2603 dev_queue_xmit_nit(skb, dev);
2606 trace_net_dev_start_xmit(skb, dev);
2607 rc = ops->ndo_start_xmit(skb, dev);
2608 trace_net_dev_xmit(skb, rc, dev, skb_len);
2609 if (rc == NETDEV_TX_OK)
2610 txq_trans_update(txq);
2616 struct sk_buff *nskb = skb->next;
2618 skb->next = nskb->next;
2621 if (!list_empty(&ptype_all))
2622 dev_queue_xmit_nit(nskb, dev);
2624 skb_len = nskb->len;
2625 trace_net_dev_start_xmit(nskb, dev);
2626 rc = ops->ndo_start_xmit(nskb, dev);
2627 trace_net_dev_xmit(nskb, rc, dev, skb_len);
2628 if (unlikely(rc != NETDEV_TX_OK)) {
2629 if (rc & ~NETDEV_TX_MASK)
2630 goto out_kfree_gso_skb;
2631 nskb->next = skb->next;
2635 txq_trans_update(txq);
2636 if (unlikely(netif_xmit_stopped(txq) && skb->next))
2637 return NETDEV_TX_BUSY;
2638 } while (skb->next);
2641 if (likely(skb->next == NULL)) {
2642 skb->destructor = DEV_GSO_CB(skb)->destructor;
2651 EXPORT_SYMBOL_GPL(dev_hard_start_xmit);
2653 static void qdisc_pkt_len_init(struct sk_buff *skb)
2655 const struct skb_shared_info *shinfo = skb_shinfo(skb);
2657 qdisc_skb_cb(skb)->pkt_len = skb->len;
2659 /* To get more precise estimation of bytes sent on wire,
2660 * we add to pkt_len the headers size of all segments
2662 if (shinfo->gso_size) {
2663 unsigned int hdr_len;
2664 u16 gso_segs = shinfo->gso_segs;
2666 /* mac layer + network layer */
2667 hdr_len = skb_transport_header(skb) - skb_mac_header(skb);
2669 /* + transport layer */
2670 if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))
2671 hdr_len += tcp_hdrlen(skb);
2673 hdr_len += sizeof(struct udphdr);
2675 if (shinfo->gso_type & SKB_GSO_DODGY)
2676 gso_segs = DIV_ROUND_UP(skb->len - hdr_len,
2679 qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len;
2683 static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
2684 struct net_device *dev,
2685 struct netdev_queue *txq)
2687 spinlock_t *root_lock = qdisc_lock(q);
2691 qdisc_pkt_len_init(skb);
2692 qdisc_calculate_pkt_len(skb, q);
2694 * Heuristic to force contended enqueues to serialize on a
2695 * separate lock before trying to get qdisc main lock.
2696 * This permits __QDISC_STATE_RUNNING owner to get the lock more often
2697 * and dequeue packets faster.
2699 contended = qdisc_is_running(q);
2700 if (unlikely(contended))
2701 spin_lock(&q->busylock);
2703 spin_lock(root_lock);
2704 if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
2707 } else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
2708 qdisc_run_begin(q)) {
2710 * This is a work-conserving queue; there are no old skbs
2711 * waiting to be sent out; and the qdisc is not running -
2712 * xmit the skb directly.
2714 if (!(dev->priv_flags & IFF_XMIT_DST_RELEASE))
2717 qdisc_bstats_update(q, skb);
2719 if (sch_direct_xmit(skb, q, dev, txq, root_lock)) {
2720 if (unlikely(contended)) {
2721 spin_unlock(&q->busylock);
2728 rc = NET_XMIT_SUCCESS;
2731 rc = q->enqueue(skb, q) & NET_XMIT_MASK;
2732 if (qdisc_run_begin(q)) {
2733 if (unlikely(contended)) {
2734 spin_unlock(&q->busylock);
2740 spin_unlock(root_lock);
2741 if (unlikely(contended))
2742 spin_unlock(&q->busylock);
2746 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
2747 static void skb_update_prio(struct sk_buff *skb)
2749 struct netprio_map *map = rcu_dereference_bh(skb->dev->priomap);
2751 if (!skb->priority && skb->sk && map) {
2752 unsigned int prioidx = skb->sk->sk_cgrp_prioidx;
2754 if (prioidx < map->priomap_len)
2755 skb->priority = map->priomap[prioidx];
2759 #define skb_update_prio(skb)
2762 static DEFINE_PER_CPU(int, xmit_recursion);
2763 #define RECURSION_LIMIT 10
2766 * dev_loopback_xmit - loop back @skb
2767 * @skb: buffer to transmit
2769 int dev_loopback_xmit(struct sk_buff *skb)
2771 skb_reset_mac_header(skb);
2772 __skb_pull(skb, skb_network_offset(skb));
2773 skb->pkt_type = PACKET_LOOPBACK;
2774 skb->ip_summed = CHECKSUM_UNNECESSARY;
2775 WARN_ON(!skb_dst(skb));
2780 EXPORT_SYMBOL(dev_loopback_xmit);
2783 * __dev_queue_xmit - transmit a buffer
2784 * @skb: buffer to transmit
2785 * @accel_priv: private data used for L2 forwarding offload
2787 * Queue a buffer for transmission to a network device. The caller must
2788 * have set the device and priority and built the buffer before calling
2789 * this function. The function can be called from an interrupt.
2791 * A negative errno code is returned on a failure. A success does not
2792 * guarantee the frame will be transmitted as it may be dropped due
2793 * to congestion or traffic shaping.
2795 * -----------------------------------------------------------------------------------
2796 * I notice this method can also return errors from the queue disciplines,
2797 * including NET_XMIT_DROP, which is a positive value. So, errors can also
2800 * Regardless of the return value, the skb is consumed, so it is currently
2801 * difficult to retry a send to this method. (You can bump the ref count
2802 * before sending to hold a reference for retry if you are careful.)
2804 * When calling this method, interrupts MUST be enabled. This is because
2805 * the BH enable code must have IRQs enabled so that it will not deadlock.
2808 static int __dev_queue_xmit(struct sk_buff *skb, void *accel_priv)
2810 struct net_device *dev = skb->dev;
2811 struct netdev_queue *txq;
2815 skb_reset_mac_header(skb);
2817 /* Disable soft irqs for various locks below. Also
2818 * stops preemption for RCU.
2822 skb_update_prio(skb);
2824 txq = netdev_pick_tx(dev, skb, accel_priv);
2825 q = rcu_dereference_bh(txq->qdisc);
2827 #ifdef CONFIG_NET_CLS_ACT
2828 skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_EGRESS);
2830 trace_net_dev_queue(skb);
2832 rc = __dev_xmit_skb(skb, q, dev, txq);
2836 /* The device has no queue. Common case for software devices:
2837 loopback, all the sorts of tunnels...
2839 Really, it is unlikely that netif_tx_lock protection is necessary
2840 here. (f.e. loopback and IP tunnels are clean ignoring statistics
2842 However, it is possible, that they rely on protection
2845 Check this and shot the lock. It is not prone from deadlocks.
2846 Either shot noqueue qdisc, it is even simpler 8)
2848 if (dev->flags & IFF_UP) {
2849 int cpu = smp_processor_id(); /* ok because BHs are off */
2851 if (txq->xmit_lock_owner != cpu) {
2853 if (__this_cpu_read(xmit_recursion) > RECURSION_LIMIT)
2854 goto recursion_alert;
2856 HARD_TX_LOCK(dev, txq, cpu);
2858 if (!netif_xmit_stopped(txq)) {
2859 __this_cpu_inc(xmit_recursion);
2860 rc = dev_hard_start_xmit(skb, dev, txq);
2861 __this_cpu_dec(xmit_recursion);
2862 if (dev_xmit_complete(rc)) {
2863 HARD_TX_UNLOCK(dev, txq);
2867 HARD_TX_UNLOCK(dev, txq);
2868 net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
2871 /* Recursion is detected! It is possible,
2875 net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
2881 rcu_read_unlock_bh();
2883 atomic_long_inc(&dev->tx_dropped);
2887 rcu_read_unlock_bh();
2891 int dev_queue_xmit(struct sk_buff *skb)
2893 return __dev_queue_xmit(skb, NULL);
2895 EXPORT_SYMBOL(dev_queue_xmit);
2897 int dev_queue_xmit_accel(struct sk_buff *skb, void *accel_priv)
2899 return __dev_queue_xmit(skb, accel_priv);
2901 EXPORT_SYMBOL(dev_queue_xmit_accel);
2904 /*=======================================================================
2906 =======================================================================*/
2908 int netdev_max_backlog __read_mostly = 1000;
2909 EXPORT_SYMBOL(netdev_max_backlog);
2911 int netdev_tstamp_prequeue __read_mostly = 1;
2912 int netdev_budget __read_mostly = 300;
2913 int weight_p __read_mostly = 64; /* old backlog weight */
2915 /* Called with irq disabled */
2916 static inline void ____napi_schedule(struct softnet_data *sd,
2917 struct napi_struct *napi)
2919 list_add_tail(&napi->poll_list, &sd->poll_list);
2920 __raise_softirq_irqoff(NET_RX_SOFTIRQ);
2925 /* One global table that all flow-based protocols share. */
2926 struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
2927 EXPORT_SYMBOL(rps_sock_flow_table);
2929 struct static_key rps_needed __read_mostly;
2931 static struct rps_dev_flow *
2932 set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
2933 struct rps_dev_flow *rflow, u16 next_cpu)
2935 if (next_cpu != RPS_NO_CPU) {
2936 #ifdef CONFIG_RFS_ACCEL
2937 struct netdev_rx_queue *rxqueue;
2938 struct rps_dev_flow_table *flow_table;
2939 struct rps_dev_flow *old_rflow;
2944 /* Should we steer this flow to a different hardware queue? */
2945 if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
2946 !(dev->features & NETIF_F_NTUPLE))
2948 rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
2949 if (rxq_index == skb_get_rx_queue(skb))
2952 rxqueue = dev->_rx + rxq_index;
2953 flow_table = rcu_dereference(rxqueue->rps_flow_table);
2956 flow_id = skb_get_hash(skb) & flow_table->mask;
2957 rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
2958 rxq_index, flow_id);
2962 rflow = &flow_table->flows[flow_id];
2964 if (old_rflow->filter == rflow->filter)
2965 old_rflow->filter = RPS_NO_FILTER;
2969 per_cpu(softnet_data, next_cpu).input_queue_head;
2972 rflow->cpu = next_cpu;
2977 * get_rps_cpu is called from netif_receive_skb and returns the target
2978 * CPU from the RPS map of the receiving queue for a given skb.
2979 * rcu_read_lock must be held on entry.
2981 static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
2982 struct rps_dev_flow **rflowp)
2984 struct netdev_rx_queue *rxqueue;
2985 struct rps_map *map;
2986 struct rps_dev_flow_table *flow_table;
2987 struct rps_sock_flow_table *sock_flow_table;
2992 if (skb_rx_queue_recorded(skb)) {
2993 u16 index = skb_get_rx_queue(skb);
2994 if (unlikely(index >= dev->real_num_rx_queues)) {
2995 WARN_ONCE(dev->real_num_rx_queues > 1,
2996 "%s received packet on queue %u, but number "
2997 "of RX queues is %u\n",
2998 dev->name, index, dev->real_num_rx_queues);
3001 rxqueue = dev->_rx + index;
3005 map = rcu_dereference(rxqueue->rps_map);
3007 if (map->len == 1 &&
3008 !rcu_access_pointer(rxqueue->rps_flow_table)) {
3009 tcpu = map->cpus[0];
3010 if (cpu_online(tcpu))
3014 } else if (!rcu_access_pointer(rxqueue->rps_flow_table)) {
3018 skb_reset_network_header(skb);
3019 hash = skb_get_hash(skb);
3023 flow_table = rcu_dereference(rxqueue->rps_flow_table);
3024 sock_flow_table = rcu_dereference(rps_sock_flow_table);
3025 if (flow_table && sock_flow_table) {
3027 struct rps_dev_flow *rflow;
3029 rflow = &flow_table->flows[hash & flow_table->mask];
3032 next_cpu = sock_flow_table->ents[hash & sock_flow_table->mask];
3035 * If the desired CPU (where last recvmsg was done) is
3036 * different from current CPU (one in the rx-queue flow
3037 * table entry), switch if one of the following holds:
3038 * - Current CPU is unset (equal to RPS_NO_CPU).
3039 * - Current CPU is offline.
3040 * - The current CPU's queue tail has advanced beyond the
3041 * last packet that was enqueued using this table entry.
3042 * This guarantees that all previous packets for the flow
3043 * have been dequeued, thus preserving in order delivery.
3045 if (unlikely(tcpu != next_cpu) &&
3046 (tcpu == RPS_NO_CPU || !cpu_online(tcpu) ||
3047 ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
3048 rflow->last_qtail)) >= 0)) {
3050 rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
3053 if (tcpu != RPS_NO_CPU && cpu_online(tcpu)) {
3061 tcpu = map->cpus[((u64) hash * map->len) >> 32];
3063 if (cpu_online(tcpu)) {
3073 #ifdef CONFIG_RFS_ACCEL
3076 * rps_may_expire_flow - check whether an RFS hardware filter may be removed
3077 * @dev: Device on which the filter was set
3078 * @rxq_index: RX queue index
3079 * @flow_id: Flow ID passed to ndo_rx_flow_steer()
3080 * @filter_id: Filter ID returned by ndo_rx_flow_steer()
3082 * Drivers that implement ndo_rx_flow_steer() should periodically call
3083 * this function for each installed filter and remove the filters for
3084 * which it returns %true.
3086 bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
3087 u32 flow_id, u16 filter_id)
3089 struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
3090 struct rps_dev_flow_table *flow_table;
3091 struct rps_dev_flow *rflow;
3096 flow_table = rcu_dereference(rxqueue->rps_flow_table);
3097 if (flow_table && flow_id <= flow_table->mask) {
3098 rflow = &flow_table->flows[flow_id];
3099 cpu = ACCESS_ONCE(rflow->cpu);
3100 if (rflow->filter == filter_id && cpu != RPS_NO_CPU &&
3101 ((int)(per_cpu(softnet_data, cpu).input_queue_head -
3102 rflow->last_qtail) <
3103 (int)(10 * flow_table->mask)))
3109 EXPORT_SYMBOL(rps_may_expire_flow);
3111 #endif /* CONFIG_RFS_ACCEL */
3113 /* Called from hardirq (IPI) context */
3114 static void rps_trigger_softirq(void *data)
3116 struct softnet_data *sd = data;
3118 ____napi_schedule(sd, &sd->backlog);
3122 #endif /* CONFIG_RPS */
3125 * Check if this softnet_data structure is another cpu one
3126 * If yes, queue it to our IPI list and return 1
3129 static int rps_ipi_queued(struct softnet_data *sd)
3132 struct softnet_data *mysd = &__get_cpu_var(softnet_data);
3135 sd->rps_ipi_next = mysd->rps_ipi_list;
3136 mysd->rps_ipi_list = sd;
3138 __raise_softirq_irqoff(NET_RX_SOFTIRQ);
3141 #endif /* CONFIG_RPS */
3145 #ifdef CONFIG_NET_FLOW_LIMIT
3146 int netdev_flow_limit_table_len __read_mostly = (1 << 12);
3149 static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen)
3151 #ifdef CONFIG_NET_FLOW_LIMIT
3152 struct sd_flow_limit *fl;
3153 struct softnet_data *sd;
3154 unsigned int old_flow, new_flow;
3156 if (qlen < (netdev_max_backlog >> 1))
3159 sd = &__get_cpu_var(softnet_data);
3162 fl = rcu_dereference(sd->flow_limit);
3164 new_flow = skb_get_hash(skb) & (fl->num_buckets - 1);
3165 old_flow = fl->history[fl->history_head];
3166 fl->history[fl->history_head] = new_flow;
3169 fl->history_head &= FLOW_LIMIT_HISTORY - 1;
3171 if (likely(fl->buckets[old_flow]))
3172 fl->buckets[old_flow]--;
3174 if (++fl->buckets[new_flow] > (FLOW_LIMIT_HISTORY >> 1)) {
3186 * enqueue_to_backlog is called to queue an skb to a per CPU backlog
3187 * queue (may be a remote CPU queue).
3189 static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
3190 unsigned int *qtail)
3192 struct softnet_data *sd;
3193 unsigned long flags;
3196 sd = &per_cpu(softnet_data, cpu);
3198 local_irq_save(flags);
3201 qlen = skb_queue_len(&sd->input_pkt_queue);
3202 if (qlen <= netdev_max_backlog && !skb_flow_limit(skb, qlen)) {
3203 if (skb_queue_len(&sd->input_pkt_queue)) {
3205 __skb_queue_tail(&sd->input_pkt_queue, skb);
3206 input_queue_tail_incr_save(sd, qtail);
3208 local_irq_restore(flags);
3209 return NET_RX_SUCCESS;
3212 /* Schedule NAPI for backlog device
3213 * We can use non atomic operation since we own the queue lock
3215 if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state)) {
3216 if (!rps_ipi_queued(sd))
3217 ____napi_schedule(sd, &sd->backlog);
3225 local_irq_restore(flags);
3227 atomic_long_inc(&skb->dev->rx_dropped);
3232 static int netif_rx_internal(struct sk_buff *skb)
3236 net_timestamp_check(netdev_tstamp_prequeue, skb);
3238 trace_netif_rx(skb);
3240 if (static_key_false(&rps_needed)) {
3241 struct rps_dev_flow voidflow, *rflow = &voidflow;
3247 cpu = get_rps_cpu(skb->dev, skb, &rflow);
3249 cpu = smp_processor_id();
3251 ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
3259 ret = enqueue_to_backlog(skb, get_cpu(), &qtail);
3266 * netif_rx - post buffer to the network code
3267 * @skb: buffer to post
3269 * This function receives a packet from a device driver and queues it for
3270 * the upper (protocol) levels to process. It always succeeds. The buffer
3271 * may be dropped during processing for congestion control or by the
3275 * NET_RX_SUCCESS (no congestion)
3276 * NET_RX_DROP (packet was dropped)
3280 int netif_rx(struct sk_buff *skb)
3282 trace_netif_rx_entry(skb);
3284 return netif_rx_internal(skb);
3286 EXPORT_SYMBOL(netif_rx);
3288 int netif_rx_ni(struct sk_buff *skb)
3292 trace_netif_rx_ni_entry(skb);
3295 err = netif_rx_internal(skb);
3296 if (local_softirq_pending())
3302 EXPORT_SYMBOL(netif_rx_ni);
3304 static void net_tx_action(struct softirq_action *h)
3306 struct softnet_data *sd = &__get_cpu_var(softnet_data);
3308 if (sd->completion_queue) {
3309 struct sk_buff *clist;
3311 local_irq_disable();
3312 clist = sd->completion_queue;
3313 sd->completion_queue = NULL;
3317 struct sk_buff *skb = clist;
3318 clist = clist->next;
3320 WARN_ON(atomic_read(&skb->users));
3321 if (likely(get_kfree_skb_cb(skb)->reason == SKB_REASON_CONSUMED))
3322 trace_consume_skb(skb);
3324 trace_kfree_skb(skb, net_tx_action);
3329 if (sd->output_queue) {
3332 local_irq_disable();
3333 head = sd->output_queue;
3334 sd->output_queue = NULL;
3335 sd->output_queue_tailp = &sd->output_queue;
3339 struct Qdisc *q = head;
3340 spinlock_t *root_lock;
3342 head = head->next_sched;
3344 root_lock = qdisc_lock(q);
3345 if (spin_trylock(root_lock)) {
3346 smp_mb__before_clear_bit();
3347 clear_bit(__QDISC_STATE_SCHED,
3350 spin_unlock(root_lock);
3352 if (!test_bit(__QDISC_STATE_DEACTIVATED,
3354 __netif_reschedule(q);
3356 smp_mb__before_clear_bit();
3357 clear_bit(__QDISC_STATE_SCHED,
3365 #if (defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)) && \
3366 (defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE))
3367 /* This hook is defined here for ATM LANE */
3368 int (*br_fdb_test_addr_hook)(struct net_device *dev,
3369 unsigned char *addr) __read_mostly;
3370 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
3373 #ifdef CONFIG_NET_CLS_ACT
3374 /* TODO: Maybe we should just force sch_ingress to be compiled in
3375 * when CONFIG_NET_CLS_ACT is? otherwise some useless instructions
3376 * a compare and 2 stores extra right now if we dont have it on
3377 * but have CONFIG_NET_CLS_ACT
3378 * NOTE: This doesn't stop any functionality; if you dont have
3379 * the ingress scheduler, you just can't add policies on ingress.
3382 static int ing_filter(struct sk_buff *skb, struct netdev_queue *rxq)
3384 struct net_device *dev = skb->dev;
3385 u32 ttl = G_TC_RTTL(skb->tc_verd);
3386 int result = TC_ACT_OK;
3389 if (unlikely(MAX_RED_LOOP < ttl++)) {
3390 net_warn_ratelimited("Redir loop detected Dropping packet (%d->%d)\n",
3391 skb->skb_iif, dev->ifindex);
3395 skb->tc_verd = SET_TC_RTTL(skb->tc_verd, ttl);
3396 skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_INGRESS);
3399 if (q != &noop_qdisc) {
3400 spin_lock(qdisc_lock(q));
3401 if (likely(!test_bit(__QDISC_STATE_DEACTIVATED, &q->state)))
3402 result = qdisc_enqueue_root(skb, q);
3403 spin_unlock(qdisc_lock(q));
3409 static inline struct sk_buff *handle_ing(struct sk_buff *skb,
3410 struct packet_type **pt_prev,
3411 int *ret, struct net_device *orig_dev)
3413 struct netdev_queue *rxq = rcu_dereference(skb->dev->ingress_queue);
3415 if (!rxq || rxq->qdisc == &noop_qdisc)
3419 *ret = deliver_skb(skb, *pt_prev, orig_dev);
3423 switch (ing_filter(skb, rxq)) {
3437 * netdev_rx_handler_register - register receive handler
3438 * @dev: device to register a handler for
3439 * @rx_handler: receive handler to register
3440 * @rx_handler_data: data pointer that is used by rx handler
3442 * Register a receive handler for a device. This handler will then be
3443 * called from __netif_receive_skb. A negative errno code is returned
3446 * The caller must hold the rtnl_mutex.
3448 * For a general description of rx_handler, see enum rx_handler_result.
3450 int netdev_rx_handler_register(struct net_device *dev,
3451 rx_handler_func_t *rx_handler,
3452 void *rx_handler_data)
3456 if (dev->rx_handler)
3459 /* Note: rx_handler_data must be set before rx_handler */
3460 rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
3461 rcu_assign_pointer(dev->rx_handler, rx_handler);
3465 EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
3468 * netdev_rx_handler_unregister - unregister receive handler
3469 * @dev: device to unregister a handler from
3471 * Unregister a receive handler from a device.
3473 * The caller must hold the rtnl_mutex.
3475 void netdev_rx_handler_unregister(struct net_device *dev)
3479 RCU_INIT_POINTER(dev->rx_handler, NULL);
3480 /* a reader seeing a non NULL rx_handler in a rcu_read_lock()
3481 * section has a guarantee to see a non NULL rx_handler_data
3485 RCU_INIT_POINTER(dev->rx_handler_data, NULL);
3487 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
3490 * Limit the use of PFMEMALLOC reserves to those protocols that implement
3491 * the special handling of PFMEMALLOC skbs.
3493 static bool skb_pfmemalloc_protocol(struct sk_buff *skb)
3495 switch (skb->protocol) {
3496 case htons(ETH_P_ARP):
3497 case htons(ETH_P_IP):
3498 case htons(ETH_P_IPV6):
3499 case htons(ETH_P_8021Q):
3500 case htons(ETH_P_8021AD):
3507 static int __netif_receive_skb_core(struct sk_buff *skb, bool pfmemalloc)
3509 struct packet_type *ptype, *pt_prev;
3510 rx_handler_func_t *rx_handler;
3511 struct net_device *orig_dev;
3512 struct net_device *null_or_dev;
3513 bool deliver_exact = false;
3514 int ret = NET_RX_DROP;
3517 net_timestamp_check(!netdev_tstamp_prequeue, skb);
3519 trace_netif_receive_skb(skb);
3521 orig_dev = skb->dev;
3523 skb_reset_network_header(skb);
3524 if (!skb_transport_header_was_set(skb))
3525 skb_reset_transport_header(skb);
3526 skb_reset_mac_len(skb);
3533 skb->skb_iif = skb->dev->ifindex;
3535 __this_cpu_inc(softnet_data.processed);
3537 if (skb->protocol == cpu_to_be16(ETH_P_8021Q) ||
3538 skb->protocol == cpu_to_be16(ETH_P_8021AD)) {
3539 skb = vlan_untag(skb);
3544 #ifdef CONFIG_NET_CLS_ACT
3545 if (skb->tc_verd & TC_NCLS) {
3546 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
3554 list_for_each_entry_rcu(ptype, &ptype_all, list) {
3555 if (!ptype->dev || ptype->dev == skb->dev) {
3557 ret = deliver_skb(skb, pt_prev, orig_dev);
3563 #ifdef CONFIG_NET_CLS_ACT
3564 skb = handle_ing(skb, &pt_prev, &ret, orig_dev);
3570 if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
3573 if (vlan_tx_tag_present(skb)) {
3575 ret = deliver_skb(skb, pt_prev, orig_dev);
3578 if (vlan_do_receive(&skb))
3580 else if (unlikely(!skb))
3584 rx_handler = rcu_dereference(skb->dev->rx_handler);
3587 ret = deliver_skb(skb, pt_prev, orig_dev);
3590 switch (rx_handler(&skb)) {
3591 case RX_HANDLER_CONSUMED:
3592 ret = NET_RX_SUCCESS;
3594 case RX_HANDLER_ANOTHER:
3596 case RX_HANDLER_EXACT:
3597 deliver_exact = true;
3598 case RX_HANDLER_PASS:
3605 if (unlikely(vlan_tx_tag_present(skb))) {
3606 if (vlan_tx_tag_get_id(skb))
3607 skb->pkt_type = PACKET_OTHERHOST;
3608 /* Note: we might in the future use prio bits
3609 * and set skb->priority like in vlan_do_receive()
3610 * For the time being, just ignore Priority Code Point
3615 /* deliver only exact match when indicated */
3616 null_or_dev = deliver_exact ? skb->dev : NULL;
3618 type = skb->protocol;
3619 list_for_each_entry_rcu(ptype,
3620 &ptype_base[ntohs(type) & PTYPE_HASH_MASK], list) {
3621 if (ptype->type == type &&
3622 (ptype->dev == null_or_dev || ptype->dev == skb->dev ||
3623 ptype->dev == orig_dev)) {
3625 ret = deliver_skb(skb, pt_prev, orig_dev);
3631 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
3634 ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
3637 atomic_long_inc(&skb->dev->rx_dropped);
3639 /* Jamal, now you will not able to escape explaining
3640 * me how you were going to use this. :-)
3650 static int __netif_receive_skb(struct sk_buff *skb)
3654 if (sk_memalloc_socks() && skb_pfmemalloc(skb)) {
3655 unsigned long pflags = current->flags;
3658 * PFMEMALLOC skbs are special, they should
3659 * - be delivered to SOCK_MEMALLOC sockets only
3660 * - stay away from userspace
3661 * - have bounded memory usage
3663 * Use PF_MEMALLOC as this saves us from propagating the allocation
3664 * context down to all allocation sites.
3666 current->flags |= PF_MEMALLOC;
3667 ret = __netif_receive_skb_core(skb, true);
3668 tsk_restore_flags(current, pflags, PF_MEMALLOC);
3670 ret = __netif_receive_skb_core(skb, false);
3675 static int netif_receive_skb_internal(struct sk_buff *skb)
3677 net_timestamp_check(netdev_tstamp_prequeue, skb);
3679 if (skb_defer_rx_timestamp(skb))
3680 return NET_RX_SUCCESS;
3683 if (static_key_false(&rps_needed)) {
3684 struct rps_dev_flow voidflow, *rflow = &voidflow;
3689 cpu = get_rps_cpu(skb->dev, skb, &rflow);
3692 ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
3699 return __netif_receive_skb(skb);
3703 * netif_receive_skb - process receive buffer from network
3704 * @skb: buffer to process
3706 * netif_receive_skb() is the main receive data processing function.
3707 * It always succeeds. The buffer may be dropped during processing
3708 * for congestion control or by the protocol layers.
3710 * This function may only be called from softirq context and interrupts
3711 * should be enabled.
3713 * Return values (usually ignored):
3714 * NET_RX_SUCCESS: no congestion
3715 * NET_RX_DROP: packet was dropped
3717 int netif_receive_skb(struct sk_buff *skb)
3719 trace_netif_receive_skb_entry(skb);
3721 return netif_receive_skb_internal(skb);
3723 EXPORT_SYMBOL(netif_receive_skb);
3725 /* Network device is going away, flush any packets still pending
3726 * Called with irqs disabled.
3728 static void flush_backlog(void *arg)
3730 struct net_device *dev = arg;
3731 struct softnet_data *sd = &__get_cpu_var(softnet_data);
3732 struct sk_buff *skb, *tmp;
3735 skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
3736 if (skb->dev == dev) {
3737 __skb_unlink(skb, &sd->input_pkt_queue);
3739 input_queue_head_incr(sd);
3744 skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
3745 if (skb->dev == dev) {
3746 __skb_unlink(skb, &sd->process_queue);
3748 input_queue_head_incr(sd);
3753 static int napi_gro_complete(struct sk_buff *skb)
3755 struct packet_offload *ptype;
3756 __be16 type = skb->protocol;
3757 struct list_head *head = &offload_base;
3760 BUILD_BUG_ON(sizeof(struct napi_gro_cb) > sizeof(skb->cb));
3762 if (NAPI_GRO_CB(skb)->count == 1) {
3763 skb_shinfo(skb)->gso_size = 0;
3768 list_for_each_entry_rcu(ptype, head, list) {
3769 if (ptype->type != type || !ptype->callbacks.gro_complete)
3772 err = ptype->callbacks.gro_complete(skb, 0);
3778 WARN_ON(&ptype->list == head);
3780 return NET_RX_SUCCESS;
3784 return netif_receive_skb_internal(skb);
3787 /* napi->gro_list contains packets ordered by age.
3788 * youngest packets at the head of it.
3789 * Complete skbs in reverse order to reduce latencies.
3791 void napi_gro_flush(struct napi_struct *napi, bool flush_old)
3793 struct sk_buff *skb, *prev = NULL;
3795 /* scan list and build reverse chain */
3796 for (skb = napi->gro_list; skb != NULL; skb = skb->next) {
3801 for (skb = prev; skb; skb = prev) {
3804 if (flush_old && NAPI_GRO_CB(skb)->age == jiffies)
3808 napi_gro_complete(skb);
3812 napi->gro_list = NULL;
3814 EXPORT_SYMBOL(napi_gro_flush);
3816 static void gro_list_prepare(struct napi_struct *napi, struct sk_buff *skb)
3819 unsigned int maclen = skb->dev->hard_header_len;
3820 u32 hash = skb_get_hash_raw(skb);
3822 for (p = napi->gro_list; p; p = p->next) {
3823 unsigned long diffs;
3825 NAPI_GRO_CB(p)->flush = 0;
3827 if (hash != skb_get_hash_raw(p)) {
3828 NAPI_GRO_CB(p)->same_flow = 0;
3832 diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev;
3833 diffs |= p->vlan_tci ^ skb->vlan_tci;
3834 if (maclen == ETH_HLEN)
3835 diffs |= compare_ether_header(skb_mac_header(p),
3836 skb_mac_header(skb));
3838 diffs = memcmp(skb_mac_header(p),
3839 skb_mac_header(skb),
3841 NAPI_GRO_CB(p)->same_flow = !diffs;
3845 static void skb_gro_reset_offset(struct sk_buff *skb)
3847 const struct skb_shared_info *pinfo = skb_shinfo(skb);
3848 const skb_frag_t *frag0 = &pinfo->frags[0];
3850 NAPI_GRO_CB(skb)->data_offset = 0;
3851 NAPI_GRO_CB(skb)->frag0 = NULL;
3852 NAPI_GRO_CB(skb)->frag0_len = 0;
3854 if (skb_mac_header(skb) == skb_tail_pointer(skb) &&
3856 !PageHighMem(skb_frag_page(frag0))) {
3857 NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0);
3858 NAPI_GRO_CB(skb)->frag0_len = skb_frag_size(frag0);
3862 static void gro_pull_from_frag0(struct sk_buff *skb, int grow)
3864 struct skb_shared_info *pinfo = skb_shinfo(skb);
3866 BUG_ON(skb->end - skb->tail < grow);
3868 memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow);
3870 skb->data_len -= grow;
3873 pinfo->frags[0].page_offset += grow;
3874 skb_frag_size_sub(&pinfo->frags[0], grow);
3876 if (unlikely(!skb_frag_size(&pinfo->frags[0]))) {
3877 skb_frag_unref(skb, 0);
3878 memmove(pinfo->frags, pinfo->frags + 1,
3879 --pinfo->nr_frags * sizeof(pinfo->frags[0]));
3883 static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3885 struct sk_buff **pp = NULL;
3886 struct packet_offload *ptype;
3887 __be16 type = skb->protocol;
3888 struct list_head *head = &offload_base;
3890 enum gro_result ret;
3893 if (!(skb->dev->features & NETIF_F_GRO))
3896 if (skb_is_gso(skb) || skb_has_frag_list(skb))
3899 gro_list_prepare(napi, skb);
3900 NAPI_GRO_CB(skb)->csum = skb->csum; /* Needed for CHECKSUM_COMPLETE */
3903 list_for_each_entry_rcu(ptype, head, list) {
3904 if (ptype->type != type || !ptype->callbacks.gro_receive)
3907 skb_set_network_header(skb, skb_gro_offset(skb));
3908 skb_reset_mac_len(skb);
3909 NAPI_GRO_CB(skb)->same_flow = 0;
3910 NAPI_GRO_CB(skb)->flush = 0;
3911 NAPI_GRO_CB(skb)->free = 0;
3912 NAPI_GRO_CB(skb)->udp_mark = 0;
3914 pp = ptype->callbacks.gro_receive(&napi->gro_list, skb);
3919 if (&ptype->list == head)
3922 same_flow = NAPI_GRO_CB(skb)->same_flow;
3923 ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED;
3926 struct sk_buff *nskb = *pp;
3930 napi_gro_complete(nskb);
3937 if (NAPI_GRO_CB(skb)->flush)
3940 if (unlikely(napi->gro_count >= MAX_GRO_SKBS)) {
3941 struct sk_buff *nskb = napi->gro_list;
3943 /* locate the end of the list to select the 'oldest' flow */
3944 while (nskb->next) {
3950 napi_gro_complete(nskb);
3954 NAPI_GRO_CB(skb)->count = 1;
3955 NAPI_GRO_CB(skb)->age = jiffies;
3956 skb_shinfo(skb)->gso_size = skb_gro_len(skb);
3957 skb->next = napi->gro_list;
3958 napi->gro_list = skb;
3962 grow = skb_gro_offset(skb) - skb_headlen(skb);
3964 gro_pull_from_frag0(skb, grow);
3973 struct packet_offload *gro_find_receive_by_type(__be16 type)
3975 struct list_head *offload_head = &offload_base;
3976 struct packet_offload *ptype;
3978 list_for_each_entry_rcu(ptype, offload_head, list) {
3979 if (ptype->type != type || !ptype->callbacks.gro_receive)
3985 EXPORT_SYMBOL(gro_find_receive_by_type);
3987 struct packet_offload *gro_find_complete_by_type(__be16 type)
3989 struct list_head *offload_head = &offload_base;
3990 struct packet_offload *ptype;
3992 list_for_each_entry_rcu(ptype, offload_head, list) {
3993 if (ptype->type != type || !ptype->callbacks.gro_complete)
3999 EXPORT_SYMBOL(gro_find_complete_by_type);
4001 static gro_result_t napi_skb_finish(gro_result_t ret, struct sk_buff *skb)
4005 if (netif_receive_skb_internal(skb))
4013 case GRO_MERGED_FREE:
4014 if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
4015 kmem_cache_free(skbuff_head_cache, skb);
4028 gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
4030 trace_napi_gro_receive_entry(skb);
4032 skb_gro_reset_offset(skb);
4034 return napi_skb_finish(dev_gro_receive(napi, skb), skb);
4036 EXPORT_SYMBOL(napi_gro_receive);
4038 static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
4040 __skb_pull(skb, skb_headlen(skb));
4041 /* restore the reserve we had after netdev_alloc_skb_ip_align() */
4042 skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb));
4044 skb->dev = napi->dev;
4050 struct sk_buff *napi_get_frags(struct napi_struct *napi)
4052 struct sk_buff *skb = napi->skb;
4055 skb = netdev_alloc_skb_ip_align(napi->dev, GRO_MAX_HEAD);
4060 EXPORT_SYMBOL(napi_get_frags);
4062 static gro_result_t napi_frags_finish(struct napi_struct *napi,
4063 struct sk_buff *skb,
4069 __skb_push(skb, ETH_HLEN);
4070 skb->protocol = eth_type_trans(skb, skb->dev);
4071 if (ret == GRO_NORMAL && netif_receive_skb_internal(skb))
4076 case GRO_MERGED_FREE:
4077 napi_reuse_skb(napi, skb);
4087 /* Upper GRO stack assumes network header starts at gro_offset=0
4088 * Drivers could call both napi_gro_frags() and napi_gro_receive()
4089 * We copy ethernet header into skb->data to have a common layout.
4091 static struct sk_buff *napi_frags_skb(struct napi_struct *napi)
4093 struct sk_buff *skb = napi->skb;
4094 const struct ethhdr *eth;
4095 unsigned int hlen = sizeof(*eth);
4099 skb_reset_mac_header(skb);
4100 skb_gro_reset_offset(skb);
4102 eth = skb_gro_header_fast(skb, 0);
4103 if (unlikely(skb_gro_header_hard(skb, hlen))) {
4104 eth = skb_gro_header_slow(skb, hlen, 0);
4105 if (unlikely(!eth)) {
4106 napi_reuse_skb(napi, skb);
4110 gro_pull_from_frag0(skb, hlen);
4111 NAPI_GRO_CB(skb)->frag0 += hlen;
4112 NAPI_GRO_CB(skb)->frag0_len -= hlen;
4114 __skb_pull(skb, hlen);
4117 * This works because the only protocols we care about don't require
4119 * We'll fix it up properly in napi_frags_finish()
4121 skb->protocol = eth->h_proto;
4126 gro_result_t napi_gro_frags(struct napi_struct *napi)
4128 struct sk_buff *skb = napi_frags_skb(napi);
4133 trace_napi_gro_frags_entry(skb);
4135 return napi_frags_finish(napi, skb, dev_gro_receive(napi, skb));
4137 EXPORT_SYMBOL(napi_gro_frags);
4140 * net_rps_action_and_irq_enable sends any pending IPI's for rps.
4141 * Note: called with local irq disabled, but exits with local irq enabled.
4143 static void net_rps_action_and_irq_enable(struct softnet_data *sd)
4146 struct softnet_data *remsd = sd->rps_ipi_list;
4149 sd->rps_ipi_list = NULL;
4153 /* Send pending IPI's to kick RPS processing on remote cpus. */
4155 struct softnet_data *next = remsd->rps_ipi_next;
4157 if (cpu_online(remsd->cpu))
4158 smp_call_function_single_async(remsd->cpu,
4167 static int process_backlog(struct napi_struct *napi, int quota)
4170 struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
4173 /* Check if we have pending ipi, its better to send them now,
4174 * not waiting net_rx_action() end.
4176 if (sd->rps_ipi_list) {
4177 local_irq_disable();
4178 net_rps_action_and_irq_enable(sd);
4181 napi->weight = weight_p;
4182 local_irq_disable();
4183 while (work < quota) {
4184 struct sk_buff *skb;
4187 while ((skb = __skb_dequeue(&sd->process_queue))) {
4189 __netif_receive_skb(skb);
4190 local_irq_disable();
4191 input_queue_head_incr(sd);
4192 if (++work >= quota) {
4199 qlen = skb_queue_len(&sd->input_pkt_queue);
4201 skb_queue_splice_tail_init(&sd->input_pkt_queue,
4202 &sd->process_queue);
4204 if (qlen < quota - work) {
4206 * Inline a custom version of __napi_complete().
4207 * only current cpu owns and manipulates this napi,
4208 * and NAPI_STATE_SCHED is the only possible flag set on backlog.
4209 * we can use a plain write instead of clear_bit(),
4210 * and we dont need an smp_mb() memory barrier.
4212 list_del(&napi->poll_list);
4215 quota = work + qlen;
4225 * __napi_schedule - schedule for receive
4226 * @n: entry to schedule
4228 * The entry's receive function will be scheduled to run
4230 void __napi_schedule(struct napi_struct *n)
4232 unsigned long flags;
4234 local_irq_save(flags);
4235 ____napi_schedule(&__get_cpu_var(softnet_data), n);
4236 local_irq_restore(flags);
4238 EXPORT_SYMBOL(__napi_schedule);
4240 void __napi_complete(struct napi_struct *n)
4242 BUG_ON(!test_bit(NAPI_STATE_SCHED, &n->state));
4243 BUG_ON(n->gro_list);
4245 list_del(&n->poll_list);
4246 smp_mb__before_clear_bit();
4247 clear_bit(NAPI_STATE_SCHED, &n->state);
4249 EXPORT_SYMBOL(__napi_complete);
4251 void napi_complete(struct napi_struct *n)
4253 unsigned long flags;
4256 * don't let napi dequeue from the cpu poll list
4257 * just in case its running on a different cpu
4259 if (unlikely(test_bit(NAPI_STATE_NPSVC, &n->state)))
4262 napi_gro_flush(n, false);
4263 local_irq_save(flags);
4265 local_irq_restore(flags);
4267 EXPORT_SYMBOL(napi_complete);
4269 /* must be called under rcu_read_lock(), as we dont take a reference */
4270 struct napi_struct *napi_by_id(unsigned int napi_id)
4272 unsigned int hash = napi_id % HASH_SIZE(napi_hash);
4273 struct napi_struct *napi;
4275 hlist_for_each_entry_rcu(napi, &napi_hash[hash], napi_hash_node)
4276 if (napi->napi_id == napi_id)
4281 EXPORT_SYMBOL_GPL(napi_by_id);
4283 void napi_hash_add(struct napi_struct *napi)
4285 if (!test_and_set_bit(NAPI_STATE_HASHED, &napi->state)) {
4287 spin_lock(&napi_hash_lock);
4289 /* 0 is not a valid id, we also skip an id that is taken
4290 * we expect both events to be extremely rare
4293 while (!napi->napi_id) {
4294 napi->napi_id = ++napi_gen_id;
4295 if (napi_by_id(napi->napi_id))
4299 hlist_add_head_rcu(&napi->napi_hash_node,
4300 &napi_hash[napi->napi_id % HASH_SIZE(napi_hash)]);
4302 spin_unlock(&napi_hash_lock);
4305 EXPORT_SYMBOL_GPL(napi_hash_add);
4307 /* Warning : caller is responsible to make sure rcu grace period
4308 * is respected before freeing memory containing @napi
4310 void napi_hash_del(struct napi_struct *napi)
4312 spin_lock(&napi_hash_lock);
4314 if (test_and_clear_bit(NAPI_STATE_HASHED, &napi->state))
4315 hlist_del_rcu(&napi->napi_hash_node);
4317 spin_unlock(&napi_hash_lock);
4319 EXPORT_SYMBOL_GPL(napi_hash_del);
4321 void netif_napi_add(struct net_device *dev, struct napi_struct *napi,
4322 int (*poll)(struct napi_struct *, int), int weight)
4324 INIT_LIST_HEAD(&napi->poll_list);
4325 napi->gro_count = 0;
4326 napi->gro_list = NULL;
4329 if (weight > NAPI_POLL_WEIGHT)
4330 pr_err_once("netif_napi_add() called with weight %d on device %s\n",
4332 napi->weight = weight;
4333 list_add(&napi->dev_list, &dev->napi_list);
4335 #ifdef CONFIG_NETPOLL
4336 spin_lock_init(&napi->poll_lock);
4337 napi->poll_owner = -1;
4339 set_bit(NAPI_STATE_SCHED, &napi->state);
4341 EXPORT_SYMBOL(netif_napi_add);
4343 void netif_napi_del(struct napi_struct *napi)
4345 list_del_init(&napi->dev_list);
4346 napi_free_frags(napi);
4348 kfree_skb_list(napi->gro_list);
4349 napi->gro_list = NULL;
4350 napi->gro_count = 0;
4352 EXPORT_SYMBOL(netif_napi_del);
4354 static void net_rx_action(struct softirq_action *h)
4356 struct softnet_data *sd = &__get_cpu_var(softnet_data);
4357 unsigned long time_limit = jiffies + 2;
4358 int budget = netdev_budget;
4361 local_irq_disable();
4363 while (!list_empty(&sd->poll_list)) {
4364 struct napi_struct *n;
4367 /* If softirq window is exhuasted then punt.
4368 * Allow this to run for 2 jiffies since which will allow
4369 * an average latency of 1.5/HZ.
4371 if (unlikely(budget <= 0 || time_after_eq(jiffies, time_limit)))
4376 /* Even though interrupts have been re-enabled, this
4377 * access is safe because interrupts can only add new
4378 * entries to the tail of this list, and only ->poll()
4379 * calls can remove this head entry from the list.
4381 n = list_first_entry(&sd->poll_list, struct napi_struct, poll_list);
4383 have = netpoll_poll_lock(n);
4387 /* This NAPI_STATE_SCHED test is for avoiding a race
4388 * with netpoll's poll_napi(). Only the entity which
4389 * obtains the lock and sees NAPI_STATE_SCHED set will
4390 * actually make the ->poll() call. Therefore we avoid
4391 * accidentally calling ->poll() when NAPI is not scheduled.
4394 if (test_bit(NAPI_STATE_SCHED, &n->state)) {
4395 work = n->poll(n, weight);
4399 WARN_ON_ONCE(work > weight);
4403 local_irq_disable();
4405 /* Drivers must not modify the NAPI state if they
4406 * consume the entire weight. In such cases this code
4407 * still "owns" the NAPI instance and therefore can
4408 * move the instance around on the list at-will.
4410 if (unlikely(work == weight)) {
4411 if (unlikely(napi_disable_pending(n))) {
4414 local_irq_disable();
4417 /* flush too old packets
4418 * If HZ < 1000, flush all packets.
4421 napi_gro_flush(n, HZ >= 1000);
4422 local_irq_disable();
4424 list_move_tail(&n->poll_list, &sd->poll_list);
4428 netpoll_poll_unlock(have);
4431 net_rps_action_and_irq_enable(sd);
4433 #ifdef CONFIG_NET_DMA
4435 * There may not be any more sk_buffs coming right now, so push
4436 * any pending DMA copies to hardware
4438 dma_issue_pending_all();
4445 __raise_softirq_irqoff(NET_RX_SOFTIRQ);
4449 struct netdev_adjacent {
4450 struct net_device *dev;
4452 /* upper master flag, there can only be one master device per list */
4455 /* counter for the number of times this device was added to us */
4458 /* private field for the users */
4461 struct list_head list;
4462 struct rcu_head rcu;
4465 static struct netdev_adjacent *__netdev_find_adj(struct net_device *dev,
4466 struct net_device *adj_dev,
4467 struct list_head *adj_list)
4469 struct netdev_adjacent *adj;
4471 list_for_each_entry(adj, adj_list, list) {
4472 if (adj->dev == adj_dev)
4479 * netdev_has_upper_dev - Check if device is linked to an upper device
4481 * @upper_dev: upper device to check
4483 * Find out if a device is linked to specified upper device and return true
4484 * in case it is. Note that this checks only immediate upper device,
4485 * not through a complete stack of devices. The caller must hold the RTNL lock.
4487 bool netdev_has_upper_dev(struct net_device *dev,
4488 struct net_device *upper_dev)
4492 return __netdev_find_adj(dev, upper_dev, &dev->all_adj_list.upper);
4494 EXPORT_SYMBOL(netdev_has_upper_dev);
4497 * netdev_has_any_upper_dev - Check if device is linked to some device
4500 * Find out if a device is linked to an upper device and return true in case
4501 * it is. The caller must hold the RTNL lock.
4503 static bool netdev_has_any_upper_dev(struct net_device *dev)
4507 return !list_empty(&dev->all_adj_list.upper);
4511 * netdev_master_upper_dev_get - Get master upper device
4514 * Find a master upper device and return pointer to it or NULL in case
4515 * it's not there. The caller must hold the RTNL lock.
4517 struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
4519 struct netdev_adjacent *upper;
4523 if (list_empty(&dev->adj_list.upper))
4526 upper = list_first_entry(&dev->adj_list.upper,
4527 struct netdev_adjacent, list);
4528 if (likely(upper->master))
4532 EXPORT_SYMBOL(netdev_master_upper_dev_get);
4534 void *netdev_adjacent_get_private(struct list_head *adj_list)
4536 struct netdev_adjacent *adj;
4538 adj = list_entry(adj_list, struct netdev_adjacent, list);
4540 return adj->private;
4542 EXPORT_SYMBOL(netdev_adjacent_get_private);
4545 * netdev_all_upper_get_next_dev_rcu - Get the next dev from upper list
4547 * @iter: list_head ** of the current position
4549 * Gets the next device from the dev's upper list, starting from iter
4550 * position. The caller must hold RCU read lock.
4552 struct net_device *netdev_all_upper_get_next_dev_rcu(struct net_device *dev,
4553 struct list_head **iter)
4555 struct netdev_adjacent *upper;
4557 WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
4559 upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
4561 if (&upper->list == &dev->all_adj_list.upper)
4564 *iter = &upper->list;
4568 EXPORT_SYMBOL(netdev_all_upper_get_next_dev_rcu);
4571 * netdev_lower_get_next_private - Get the next ->private from the
4572 * lower neighbour list
4574 * @iter: list_head ** of the current position
4576 * Gets the next netdev_adjacent->private from the dev's lower neighbour
4577 * list, starting from iter position. The caller must hold either hold the
4578 * RTNL lock or its own locking that guarantees that the neighbour lower
4579 * list will remain unchainged.
4581 void *netdev_lower_get_next_private(struct net_device *dev,
4582 struct list_head **iter)
4584 struct netdev_adjacent *lower;
4586 lower = list_entry(*iter, struct netdev_adjacent, list);
4588 if (&lower->list == &dev->adj_list.lower)
4592 *iter = lower->list.next;
4594 return lower->private;
4596 EXPORT_SYMBOL(netdev_lower_get_next_private);
4599 * netdev_lower_get_next_private_rcu - Get the next ->private from the
4600 * lower neighbour list, RCU
4603 * @iter: list_head ** of the current position
4605 * Gets the next netdev_adjacent->private from the dev's lower neighbour
4606 * list, starting from iter position. The caller must hold RCU read lock.
4608 void *netdev_lower_get_next_private_rcu(struct net_device *dev,
4609 struct list_head **iter)
4611 struct netdev_adjacent *lower;
4613 WARN_ON_ONCE(!rcu_read_lock_held());
4615 lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
4617 if (&lower->list == &dev->adj_list.lower)
4621 *iter = &lower->list;
4623 return lower->private;
4625 EXPORT_SYMBOL(netdev_lower_get_next_private_rcu);
4628 * netdev_lower_get_first_private_rcu - Get the first ->private from the
4629 * lower neighbour list, RCU
4633 * Gets the first netdev_adjacent->private from the dev's lower neighbour
4634 * list. The caller must hold RCU read lock.
4636 void *netdev_lower_get_first_private_rcu(struct net_device *dev)
4638 struct netdev_adjacent *lower;
4640 lower = list_first_or_null_rcu(&dev->adj_list.lower,
4641 struct netdev_adjacent, list);
4643 return lower->private;
4646 EXPORT_SYMBOL(netdev_lower_get_first_private_rcu);
4649 * netdev_master_upper_dev_get_rcu - Get master upper device
4652 * Find a master upper device and return pointer to it or NULL in case
4653 * it's not there. The caller must hold the RCU read lock.
4655 struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev)
4657 struct netdev_adjacent *upper;
4659 upper = list_first_or_null_rcu(&dev->adj_list.upper,
4660 struct netdev_adjacent, list);
4661 if (upper && likely(upper->master))
4665 EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);
4667 static int netdev_adjacent_sysfs_add(struct net_device *dev,
4668 struct net_device *adj_dev,
4669 struct list_head *dev_list)
4671 char linkname[IFNAMSIZ+7];
4672 sprintf(linkname, dev_list == &dev->adj_list.upper ?
4673 "upper_%s" : "lower_%s", adj_dev->name);
4674 return sysfs_create_link(&(dev->dev.kobj), &(adj_dev->dev.kobj),
4677 static void netdev_adjacent_sysfs_del(struct net_device *dev,
4679 struct list_head *dev_list)
4681 char linkname[IFNAMSIZ+7];
4682 sprintf(linkname, dev_list == &dev->adj_list.upper ?
4683 "upper_%s" : "lower_%s", name);
4684 sysfs_remove_link(&(dev->dev.kobj), linkname);
4687 #define netdev_adjacent_is_neigh_list(dev, dev_list) \
4688 (dev_list == &dev->adj_list.upper || \
4689 dev_list == &dev->adj_list.lower)
4691 static int __netdev_adjacent_dev_insert(struct net_device *dev,
4692 struct net_device *adj_dev,
4693 struct list_head *dev_list,
4694 void *private, bool master)
4696 struct netdev_adjacent *adj;
4699 adj = __netdev_find_adj(dev, adj_dev, dev_list);
4706 adj = kmalloc(sizeof(*adj), GFP_KERNEL);
4711 adj->master = master;
4713 adj->private = private;
4716 pr_debug("dev_hold for %s, because of link added from %s to %s\n",
4717 adj_dev->name, dev->name, adj_dev->name);
4719 if (netdev_adjacent_is_neigh_list(dev, dev_list)) {
4720 ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list);
4725 /* Ensure that master link is always the first item in list. */
4727 ret = sysfs_create_link(&(dev->dev.kobj),
4728 &(adj_dev->dev.kobj), "master");
4730 goto remove_symlinks;
4732 list_add_rcu(&adj->list, dev_list);
4734 list_add_tail_rcu(&adj->list, dev_list);
4740 if (netdev_adjacent_is_neigh_list(dev, dev_list))
4741 netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
4749 static void __netdev_adjacent_dev_remove(struct net_device *dev,
4750 struct net_device *adj_dev,
4751 struct list_head *dev_list)
4753 struct netdev_adjacent *adj;
4755 adj = __netdev_find_adj(dev, adj_dev, dev_list);
4758 pr_err("tried to remove device %s from %s\n",
4759 dev->name, adj_dev->name);
4763 if (adj->ref_nr > 1) {
4764 pr_debug("%s to %s ref_nr-- = %d\n", dev->name, adj_dev->name,
4771 sysfs_remove_link(&(dev->dev.kobj), "master");
4773 if (netdev_adjacent_is_neigh_list(dev, dev_list))
4774 netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
4776 list_del_rcu(&adj->list);
4777 pr_debug("dev_put for %s, because link removed from %s to %s\n",
4778 adj_dev->name, dev->name, adj_dev->name);
4780 kfree_rcu(adj, rcu);
4783 static int __netdev_adjacent_dev_link_lists(struct net_device *dev,
4784 struct net_device *upper_dev,
4785 struct list_head *up_list,
4786 struct list_head *down_list,
4787 void *private, bool master)
4791 ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list, private,
4796 ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list, private,
4799 __netdev_adjacent_dev_remove(dev, upper_dev, up_list);
4806 static int __netdev_adjacent_dev_link(struct net_device *dev,
4807 struct net_device *upper_dev)
4809 return __netdev_adjacent_dev_link_lists(dev, upper_dev,
4810 &dev->all_adj_list.upper,
4811 &upper_dev->all_adj_list.lower,
4815 static void __netdev_adjacent_dev_unlink_lists(struct net_device *dev,
4816 struct net_device *upper_dev,
4817 struct list_head *up_list,
4818 struct list_head *down_list)
4820 __netdev_adjacent_dev_remove(dev, upper_dev, up_list);
4821 __netdev_adjacent_dev_remove(upper_dev, dev, down_list);
4824 static void __netdev_adjacent_dev_unlink(struct net_device *dev,
4825 struct net_device *upper_dev)
4827 __netdev_adjacent_dev_unlink_lists(dev, upper_dev,
4828 &dev->all_adj_list.upper,
4829 &upper_dev->all_adj_list.lower);
4832 static int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
4833 struct net_device *upper_dev,
4834 void *private, bool master)
4836 int ret = __netdev_adjacent_dev_link(dev, upper_dev);
4841 ret = __netdev_adjacent_dev_link_lists(dev, upper_dev,
4842 &dev->adj_list.upper,
4843 &upper_dev->adj_list.lower,
4846 __netdev_adjacent_dev_unlink(dev, upper_dev);
4853 static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
4854 struct net_device *upper_dev)
4856 __netdev_adjacent_dev_unlink(dev, upper_dev);
4857 __netdev_adjacent_dev_unlink_lists(dev, upper_dev,
4858 &dev->adj_list.upper,
4859 &upper_dev->adj_list.lower);
4862 static int __netdev_upper_dev_link(struct net_device *dev,
4863 struct net_device *upper_dev, bool master,
4866 struct netdev_adjacent *i, *j, *to_i, *to_j;
4871 if (dev == upper_dev)
4874 /* To prevent loops, check if dev is not upper device to upper_dev. */
4875 if (__netdev_find_adj(upper_dev, dev, &upper_dev->all_adj_list.upper))
4878 if (__netdev_find_adj(dev, upper_dev, &dev->all_adj_list.upper))
4881 if (master && netdev_master_upper_dev_get(dev))
4884 ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, private,
4889 /* Now that we linked these devs, make all the upper_dev's
4890 * all_adj_list.upper visible to every dev's all_adj_list.lower an
4891 * versa, and don't forget the devices itself. All of these
4892 * links are non-neighbours.
4894 list_for_each_entry(i, &dev->all_adj_list.lower, list) {
4895 list_for_each_entry(j, &upper_dev->all_adj_list.upper, list) {
4896 pr_debug("Interlinking %s with %s, non-neighbour\n",
4897 i->dev->name, j->dev->name);
4898 ret = __netdev_adjacent_dev_link(i->dev, j->dev);
4904 /* add dev to every upper_dev's upper device */
4905 list_for_each_entry(i, &upper_dev->all_adj_list.upper, list) {
4906 pr_debug("linking %s's upper device %s with %s\n",
4907 upper_dev->name, i->dev->name, dev->name);
4908 ret = __netdev_adjacent_dev_link(dev, i->dev);
4910 goto rollback_upper_mesh;
4913 /* add upper_dev to every dev's lower device */
4914 list_for_each_entry(i, &dev->all_adj_list.lower, list) {
4915 pr_debug("linking %s's lower device %s with %s\n", dev->name,
4916 i->dev->name, upper_dev->name);
4917 ret = __netdev_adjacent_dev_link(i->dev, upper_dev);
4919 goto rollback_lower_mesh;
4922 call_netdevice_notifiers(NETDEV_CHANGEUPPER, dev);
4925 rollback_lower_mesh:
4927 list_for_each_entry(i, &dev->all_adj_list.lower, list) {
4930 __netdev_adjacent_dev_unlink(i->dev, upper_dev);
4935 rollback_upper_mesh:
4937 list_for_each_entry(i, &upper_dev->all_adj_list.upper, list) {
4940 __netdev_adjacent_dev_unlink(dev, i->dev);
4948 list_for_each_entry(i, &dev->all_adj_list.lower, list) {
4949 list_for_each_entry(j, &upper_dev->all_adj_list.upper, list) {
4950 if (i == to_i && j == to_j)
4952 __netdev_adjacent_dev_unlink(i->dev, j->dev);
4958 __netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
4964 * netdev_upper_dev_link - Add a link to the upper device
4966 * @upper_dev: new upper device
4968 * Adds a link to device which is upper to this one. The caller must hold
4969 * the RTNL lock. On a failure a negative errno code is returned.
4970 * On success the reference counts are adjusted and the function
4973 int netdev_upper_dev_link(struct net_device *dev,
4974 struct net_device *upper_dev)
4976 return __netdev_upper_dev_link(dev, upper_dev, false, NULL);
4978 EXPORT_SYMBOL(netdev_upper_dev_link);
4981 * netdev_master_upper_dev_link - Add a master link to the upper device
4983 * @upper_dev: new upper device
4985 * Adds a link to device which is upper to this one. In this case, only
4986 * one master upper device can be linked, although other non-master devices
4987 * might be linked as well. The caller must hold the RTNL lock.
4988 * On a failure a negative errno code is returned. On success the reference
4989 * counts are adjusted and the function returns zero.
4991 int netdev_master_upper_dev_link(struct net_device *dev,
4992 struct net_device *upper_dev)
4994 return __netdev_upper_dev_link(dev, upper_dev, true, NULL);
4996 EXPORT_SYMBOL(netdev_master_upper_dev_link);
4998 int netdev_master_upper_dev_link_private(struct net_device *dev,
4999 struct net_device *upper_dev,
5002 return __netdev_upper_dev_link(dev, upper_dev, true, private);
5004 EXPORT_SYMBOL(netdev_master_upper_dev_link_private);
5007 * netdev_upper_dev_unlink - Removes a link to upper device
5009 * @upper_dev: new upper device
5011 * Removes a link to device which is upper to this one. The caller must hold
5014 void netdev_upper_dev_unlink(struct net_device *dev,
5015 struct net_device *upper_dev)
5017 struct netdev_adjacent *i, *j;
5020 __netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
5022 /* Here is the tricky part. We must remove all dev's lower
5023 * devices from all upper_dev's upper devices and vice
5024 * versa, to maintain the graph relationship.
5026 list_for_each_entry(i, &dev->all_adj_list.lower, list)
5027 list_for_each_entry(j, &upper_dev->all_adj_list.upper, list)
5028 __netdev_adjacent_dev_unlink(i->dev, j->dev);
5030 /* remove also the devices itself from lower/upper device
5033 list_for_each_entry(i, &dev->all_adj_list.lower, list)
5034 __netdev_adjacent_dev_unlink(i->dev, upper_dev);
5036 list_for_each_entry(i, &upper_dev->all_adj_list.upper, list)
5037 __netdev_adjacent_dev_unlink(dev, i->dev);
5039 call_netdevice_notifiers(NETDEV_CHANGEUPPER, dev);
5041 EXPORT_SYMBOL(netdev_upper_dev_unlink);
5043 void netdev_adjacent_rename_links(struct net_device *dev, char *oldname)
5045 struct netdev_adjacent *iter;
5047 list_for_each_entry(iter, &dev->adj_list.upper, list) {
5048 netdev_adjacent_sysfs_del(iter->dev, oldname,
5049 &iter->dev->adj_list.lower);
5050 netdev_adjacent_sysfs_add(iter->dev, dev,
5051 &iter->dev->adj_list.lower);
5054 list_for_each_entry(iter, &dev->adj_list.lower, list) {
5055 netdev_adjacent_sysfs_del(iter->dev, oldname,
5056 &iter->dev->adj_list.upper);
5057 netdev_adjacent_sysfs_add(iter->dev, dev,
5058 &iter->dev->adj_list.upper);
5062 void *netdev_lower_dev_get_private(struct net_device *dev,
5063 struct net_device *lower_dev)
5065 struct netdev_adjacent *lower;
5069 lower = __netdev_find_adj(dev, lower_dev, &dev->adj_list.lower);
5073 return lower->private;
5075 EXPORT_SYMBOL(netdev_lower_dev_get_private);
5077 static void dev_change_rx_flags(struct net_device *dev, int flags)
5079 const struct net_device_ops *ops = dev->netdev_ops;
5081 if (ops->ndo_change_rx_flags)
5082 ops->ndo_change_rx_flags(dev, flags);
5085 static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify)
5087 unsigned int old_flags = dev->flags;
5093 dev->flags |= IFF_PROMISC;
5094 dev->promiscuity += inc;
5095 if (dev->promiscuity == 0) {
5098 * If inc causes overflow, untouch promisc and return error.
5101 dev->flags &= ~IFF_PROMISC;
5103 dev->promiscuity -= inc;
5104 pr_warn("%s: promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n",
5109 if (dev->flags != old_flags) {
5110 pr_info("device %s %s promiscuous mode\n",
5112 dev->flags & IFF_PROMISC ? "entered" : "left");
5113 if (audit_enabled) {
5114 current_uid_gid(&uid, &gid);
5115 audit_log(current->audit_context, GFP_ATOMIC,
5116 AUDIT_ANOM_PROMISCUOUS,
5117 "dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
5118 dev->name, (dev->flags & IFF_PROMISC),
5119 (old_flags & IFF_PROMISC),
5120 from_kuid(&init_user_ns, audit_get_loginuid(current)),
5121 from_kuid(&init_user_ns, uid),
5122 from_kgid(&init_user_ns, gid),
5123 audit_get_sessionid(current));
5126 dev_change_rx_flags(dev, IFF_PROMISC);
5129 __dev_notify_flags(dev, old_flags, IFF_PROMISC);
5134 * dev_set_promiscuity - update promiscuity count on a device
5138 * Add or remove promiscuity from a device. While the count in the device
5139 * remains above zero the interface remains promiscuous. Once it hits zero
5140 * the device reverts back to normal filtering operation. A negative inc
5141 * value is used to drop promiscuity on the device.
5142 * Return 0 if successful or a negative errno code on error.
5144 int dev_set_promiscuity(struct net_device *dev, int inc)
5146 unsigned int old_flags = dev->flags;
5149 err = __dev_set_promiscuity(dev, inc, true);
5152 if (dev->flags != old_flags)
5153 dev_set_rx_mode(dev);
5156 EXPORT_SYMBOL(dev_set_promiscuity);
5158 static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify)
5160 unsigned int old_flags = dev->flags, old_gflags = dev->gflags;
5164 dev->flags |= IFF_ALLMULTI;
5165 dev->allmulti += inc;
5166 if (dev->allmulti == 0) {
5169 * If inc causes overflow, untouch allmulti and return error.
5172 dev->flags &= ~IFF_ALLMULTI;
5174 dev->allmulti -= inc;
5175 pr_warn("%s: allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n",
5180 if (dev->flags ^ old_flags) {
5181 dev_change_rx_flags(dev, IFF_ALLMULTI);
5182 dev_set_rx_mode(dev);
5184 __dev_notify_flags(dev, old_flags,
5185 dev->gflags ^ old_gflags);
5191 * dev_set_allmulti - update allmulti count on a device
5195 * Add or remove reception of all multicast frames to a device. While the
5196 * count in the device remains above zero the interface remains listening
5197 * to all interfaces. Once it hits zero the device reverts back to normal
5198 * filtering operation. A negative @inc value is used to drop the counter
5199 * when releasing a resource needing all multicasts.
5200 * Return 0 if successful or a negative errno code on error.
5203 int dev_set_allmulti(struct net_device *dev, int inc)
5205 return __dev_set_allmulti(dev, inc, true);
5207 EXPORT_SYMBOL(dev_set_allmulti);
5210 * Upload unicast and multicast address lists to device and
5211 * configure RX filtering. When the device doesn't support unicast
5212 * filtering it is put in promiscuous mode while unicast addresses
5215 void __dev_set_rx_mode(struct net_device *dev)
5217 const struct net_device_ops *ops = dev->netdev_ops;
5219 /* dev_open will call this function so the list will stay sane. */
5220 if (!(dev->flags&IFF_UP))
5223 if (!netif_device_present(dev))
5226 if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
5227 /* Unicast addresses changes may only happen under the rtnl,
5228 * therefore calling __dev_set_promiscuity here is safe.
5230 if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
5231 __dev_set_promiscuity(dev, 1, false);
5232 dev->uc_promisc = true;
5233 } else if (netdev_uc_empty(dev) && dev->uc_promisc) {
5234 __dev_set_promiscuity(dev, -1, false);
5235 dev->uc_promisc = false;
5239 if (ops->ndo_set_rx_mode)
5240 ops->ndo_set_rx_mode(dev);
5243 void dev_set_rx_mode(struct net_device *dev)
5245 netif_addr_lock_bh(dev);
5246 __dev_set_rx_mode(dev);
5247 netif_addr_unlock_bh(dev);
5251 * dev_get_flags - get flags reported to userspace
5254 * Get the combination of flag bits exported through APIs to userspace.
5256 unsigned int dev_get_flags(const struct net_device *dev)
5260 flags = (dev->flags & ~(IFF_PROMISC |
5265 (dev->gflags & (IFF_PROMISC |
5268 if (netif_running(dev)) {
5269 if (netif_oper_up(dev))
5270 flags |= IFF_RUNNING;
5271 if (netif_carrier_ok(dev))
5272 flags |= IFF_LOWER_UP;
5273 if (netif_dormant(dev))
5274 flags |= IFF_DORMANT;
5279 EXPORT_SYMBOL(dev_get_flags);
5281 int __dev_change_flags(struct net_device *dev, unsigned int flags)
5283 unsigned int old_flags = dev->flags;
5289 * Set the flags on our device.
5292 dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
5293 IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
5295 (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
5299 * Load in the correct multicast list now the flags have changed.
5302 if ((old_flags ^ flags) & IFF_MULTICAST)
5303 dev_change_rx_flags(dev, IFF_MULTICAST);
5305 dev_set_rx_mode(dev);
5308 * Have we downed the interface. We handle IFF_UP ourselves
5309 * according to user attempts to set it, rather than blindly
5314 if ((old_flags ^ flags) & IFF_UP) { /* Bit is different ? */
5315 ret = ((old_flags & IFF_UP) ? __dev_close : __dev_open)(dev);
5318 dev_set_rx_mode(dev);
5321 if ((flags ^ dev->gflags) & IFF_PROMISC) {
5322 int inc = (flags & IFF_PROMISC) ? 1 : -1;
5323 unsigned int old_flags = dev->flags;
5325 dev->gflags ^= IFF_PROMISC;
5327 if (__dev_set_promiscuity(dev, inc, false) >= 0)
5328 if (dev->flags != old_flags)
5329 dev_set_rx_mode(dev);
5332 /* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
5333 is important. Some (broken) drivers set IFF_PROMISC, when
5334 IFF_ALLMULTI is requested not asking us and not reporting.
5336 if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
5337 int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
5339 dev->gflags ^= IFF_ALLMULTI;
5340 __dev_set_allmulti(dev, inc, false);
5346 void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
5347 unsigned int gchanges)
5349 unsigned int changes = dev->flags ^ old_flags;
5352 rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC);
5354 if (changes & IFF_UP) {
5355 if (dev->flags & IFF_UP)
5356 call_netdevice_notifiers(NETDEV_UP, dev);
5358 call_netdevice_notifiers(NETDEV_DOWN, dev);
5361 if (dev->flags & IFF_UP &&
5362 (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE))) {
5363 struct netdev_notifier_change_info change_info;
5365 change_info.flags_changed = changes;
5366 call_netdevice_notifiers_info(NETDEV_CHANGE, dev,
5372 * dev_change_flags - change device settings
5374 * @flags: device state flags
5376 * Change settings on device based state flags. The flags are
5377 * in the userspace exported format.
5379 int dev_change_flags(struct net_device *dev, unsigned int flags)
5382 unsigned int changes, old_flags = dev->flags, old_gflags = dev->gflags;
5384 ret = __dev_change_flags(dev, flags);
5388 changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags);
5389 __dev_notify_flags(dev, old_flags, changes);
5392 EXPORT_SYMBOL(dev_change_flags);
5394 static int __dev_set_mtu(struct net_device *dev, int new_mtu)
5396 const struct net_device_ops *ops = dev->netdev_ops;
5398 if (ops->ndo_change_mtu)
5399 return ops->ndo_change_mtu(dev, new_mtu);
5406 * dev_set_mtu - Change maximum transfer unit
5408 * @new_mtu: new transfer unit
5410 * Change the maximum transfer size of the network device.
5412 int dev_set_mtu(struct net_device *dev, int new_mtu)
5416 if (new_mtu == dev->mtu)
5419 /* MTU must be positive. */
5423 if (!netif_device_present(dev))
5426 err = call_netdevice_notifiers(NETDEV_PRECHANGEMTU, dev);
5427 err = notifier_to_errno(err);
5431 orig_mtu = dev->mtu;
5432 err = __dev_set_mtu(dev, new_mtu);
5435 err = call_netdevice_notifiers(NETDEV_CHANGEMTU, dev);
5436 err = notifier_to_errno(err);
5438 /* setting mtu back and notifying everyone again,
5439 * so that they have a chance to revert changes.
5441 __dev_set_mtu(dev, orig_mtu);
5442 call_netdevice_notifiers(NETDEV_CHANGEMTU, dev);
5447 EXPORT_SYMBOL(dev_set_mtu);
5450 * dev_set_group - Change group this device belongs to
5452 * @new_group: group this device should belong to
5454 void dev_set_group(struct net_device *dev, int new_group)
5456 dev->group = new_group;
5458 EXPORT_SYMBOL(dev_set_group);
5461 * dev_set_mac_address - Change Media Access Control Address
5465 * Change the hardware (MAC) address of the device
5467 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
5469 const struct net_device_ops *ops = dev->netdev_ops;
5472 if (!ops->ndo_set_mac_address)
5474 if (sa->sa_family != dev->type)
5476 if (!netif_device_present(dev))
5478 err = ops->ndo_set_mac_address(dev, sa);
5481 dev->addr_assign_type = NET_ADDR_SET;
5482 call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
5483 add_device_randomness(dev->dev_addr, dev->addr_len);
5486 EXPORT_SYMBOL(dev_set_mac_address);
5489 * dev_change_carrier - Change device carrier
5491 * @new_carrier: new value
5493 * Change device carrier
5495 int dev_change_carrier(struct net_device *dev, bool new_carrier)
5497 const struct net_device_ops *ops = dev->netdev_ops;
5499 if (!ops->ndo_change_carrier)
5501 if (!netif_device_present(dev))
5503 return ops->ndo_change_carrier(dev, new_carrier);
5505 EXPORT_SYMBOL(dev_change_carrier);
5508 * dev_get_phys_port_id - Get device physical port ID
5512 * Get device physical port ID
5514 int dev_get_phys_port_id(struct net_device *dev,
5515 struct netdev_phys_port_id *ppid)
5517 const struct net_device_ops *ops = dev->netdev_ops;
5519 if (!ops->ndo_get_phys_port_id)
5521 return ops->ndo_get_phys_port_id(dev, ppid);
5523 EXPORT_SYMBOL(dev_get_phys_port_id);
5526 * dev_new_index - allocate an ifindex
5527 * @net: the applicable net namespace
5529 * Returns a suitable unique value for a new device interface
5530 * number. The caller must hold the rtnl semaphore or the
5531 * dev_base_lock to be sure it remains unique.
5533 static int dev_new_index(struct net *net)
5535 int ifindex = net->ifindex;
5539 if (!__dev_get_by_index(net, ifindex))
5540 return net->ifindex = ifindex;
5544 /* Delayed registration/unregisteration */
5545 static LIST_HEAD(net_todo_list);
5546 static DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq);
5548 static void net_set_todo(struct net_device *dev)
5550 list_add_tail(&dev->todo_list, &net_todo_list);
5551 dev_net(dev)->dev_unreg_count++;
5554 static void rollback_registered_many(struct list_head *head)
5556 struct net_device *dev, *tmp;
5557 LIST_HEAD(close_head);
5559 BUG_ON(dev_boot_phase);
5562 list_for_each_entry_safe(dev, tmp, head, unreg_list) {
5563 /* Some devices call without registering
5564 * for initialization unwind. Remove those
5565 * devices and proceed with the remaining.
5567 if (dev->reg_state == NETREG_UNINITIALIZED) {
5568 pr_debug("unregister_netdevice: device %s/%p never was registered\n",
5572 list_del(&dev->unreg_list);
5575 dev->dismantle = true;
5576 BUG_ON(dev->reg_state != NETREG_REGISTERED);
5579 /* If device is running, close it first. */
5580 list_for_each_entry(dev, head, unreg_list)
5581 list_add_tail(&dev->close_list, &close_head);
5582 dev_close_many(&close_head);
5584 list_for_each_entry(dev, head, unreg_list) {
5585 /* And unlink it from device chain. */
5586 unlist_netdevice(dev);
5588 dev->reg_state = NETREG_UNREGISTERING;
5593 list_for_each_entry(dev, head, unreg_list) {
5594 /* Shutdown queueing discipline. */
5598 /* Notify protocols, that we are about to destroy
5599 this device. They should clean all the things.
5601 call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
5603 if (!dev->rtnl_link_ops ||
5604 dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
5605 rtmsg_ifinfo(RTM_DELLINK, dev, ~0U, GFP_KERNEL);
5608 * Flush the unicast and multicast chains
5613 if (dev->netdev_ops->ndo_uninit)
5614 dev->netdev_ops->ndo_uninit(dev);
5616 /* Notifier chain MUST detach us all upper devices. */
5617 WARN_ON(netdev_has_any_upper_dev(dev));
5619 /* Remove entries from kobject tree */
5620 netdev_unregister_kobject(dev);
5622 /* Remove XPS queueing entries */
5623 netif_reset_xps_queues_gt(dev, 0);
5629 list_for_each_entry(dev, head, unreg_list)
5633 static void rollback_registered(struct net_device *dev)
5637 list_add(&dev->unreg_list, &single);
5638 rollback_registered_many(&single);
5642 static netdev_features_t netdev_fix_features(struct net_device *dev,
5643 netdev_features_t features)
5645 /* Fix illegal checksum combinations */
5646 if ((features & NETIF_F_HW_CSUM) &&
5647 (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
5648 netdev_warn(dev, "mixed HW and IP checksum settings.\n");
5649 features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
5652 /* TSO requires that SG is present as well. */
5653 if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
5654 netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
5655 features &= ~NETIF_F_ALL_TSO;
5658 if ((features & NETIF_F_TSO) && !(features & NETIF_F_HW_CSUM) &&
5659 !(features & NETIF_F_IP_CSUM)) {
5660 netdev_dbg(dev, "Dropping TSO features since no CSUM feature.\n");
5661 features &= ~NETIF_F_TSO;
5662 features &= ~NETIF_F_TSO_ECN;
5665 if ((features & NETIF_F_TSO6) && !(features & NETIF_F_HW_CSUM) &&
5666 !(features & NETIF_F_IPV6_CSUM)) {
5667 netdev_dbg(dev, "Dropping TSO6 features since no CSUM feature.\n");
5668 features &= ~NETIF_F_TSO6;
5671 /* TSO ECN requires that TSO is present as well. */
5672 if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
5673 features &= ~NETIF_F_TSO_ECN;
5675 /* Software GSO depends on SG. */
5676 if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
5677 netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
5678 features &= ~NETIF_F_GSO;
5681 /* UFO needs SG and checksumming */
5682 if (features & NETIF_F_UFO) {
5683 /* maybe split UFO into V4 and V6? */
5684 if (!((features & NETIF_F_GEN_CSUM) ||
5685 (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))
5686 == (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
5688 "Dropping NETIF_F_UFO since no checksum offload features.\n");
5689 features &= ~NETIF_F_UFO;
5692 if (!(features & NETIF_F_SG)) {
5694 "Dropping NETIF_F_UFO since no NETIF_F_SG feature.\n");
5695 features &= ~NETIF_F_UFO;
5702 int __netdev_update_features(struct net_device *dev)
5704 netdev_features_t features;
5709 features = netdev_get_wanted_features(dev);
5711 if (dev->netdev_ops->ndo_fix_features)
5712 features = dev->netdev_ops->ndo_fix_features(dev, features);
5714 /* driver might be less strict about feature dependencies */
5715 features = netdev_fix_features(dev, features);
5717 if (dev->features == features)
5720 netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
5721 &dev->features, &features);
5723 if (dev->netdev_ops->ndo_set_features)
5724 err = dev->netdev_ops->ndo_set_features(dev, features);
5726 if (unlikely(err < 0)) {
5728 "set_features() failed (%d); wanted %pNF, left %pNF\n",
5729 err, &features, &dev->features);
5734 dev->features = features;
5740 * netdev_update_features - recalculate device features
5741 * @dev: the device to check
5743 * Recalculate dev->features set and send notifications if it
5744 * has changed. Should be called after driver or hardware dependent
5745 * conditions might have changed that influence the features.
5747 void netdev_update_features(struct net_device *dev)
5749 if (__netdev_update_features(dev))
5750 netdev_features_change(dev);
5752 EXPORT_SYMBOL(netdev_update_features);
5755 * netdev_change_features - recalculate device features
5756 * @dev: the device to check
5758 * Recalculate dev->features set and send notifications even
5759 * if they have not changed. Should be called instead of
5760 * netdev_update_features() if also dev->vlan_features might
5761 * have changed to allow the changes to be propagated to stacked
5764 void netdev_change_features(struct net_device *dev)
5766 __netdev_update_features(dev);
5767 netdev_features_change(dev);
5769 EXPORT_SYMBOL(netdev_change_features);
5772 * netif_stacked_transfer_operstate - transfer operstate
5773 * @rootdev: the root or lower level device to transfer state from
5774 * @dev: the device to transfer operstate to
5776 * Transfer operational state from root to device. This is normally
5777 * called when a stacking relationship exists between the root
5778 * device and the device(a leaf device).
5780 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
5781 struct net_device *dev)
5783 if (rootdev->operstate == IF_OPER_DORMANT)
5784 netif_dormant_on(dev);
5786 netif_dormant_off(dev);
5788 if (netif_carrier_ok(rootdev)) {
5789 if (!netif_carrier_ok(dev))
5790 netif_carrier_on(dev);
5792 if (netif_carrier_ok(dev))
5793 netif_carrier_off(dev);
5796 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
5799 static int netif_alloc_rx_queues(struct net_device *dev)
5801 unsigned int i, count = dev->num_rx_queues;
5802 struct netdev_rx_queue *rx;
5806 rx = kcalloc(count, sizeof(struct netdev_rx_queue), GFP_KERNEL);
5812 for (i = 0; i < count; i++)
5818 static void netdev_init_one_queue(struct net_device *dev,
5819 struct netdev_queue *queue, void *_unused)
5821 /* Initialize queue lock */
5822 spin_lock_init(&queue->_xmit_lock);
5823 netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
5824 queue->xmit_lock_owner = -1;
5825 netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
5828 dql_init(&queue->dql, HZ);
5832 static void netif_free_tx_queues(struct net_device *dev)
5834 if (is_vmalloc_addr(dev->_tx))
5840 static int netif_alloc_netdev_queues(struct net_device *dev)
5842 unsigned int count = dev->num_tx_queues;
5843 struct netdev_queue *tx;
5844 size_t sz = count * sizeof(*tx);
5846 BUG_ON(count < 1 || count > 0xffff);
5848 tx = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
5856 netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
5857 spin_lock_init(&dev->tx_global_lock);
5863 * register_netdevice - register a network device
5864 * @dev: device to register
5866 * Take a completed network device structure and add it to the kernel
5867 * interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
5868 * chain. 0 is returned on success. A negative errno code is returned
5869 * on a failure to set up the device, or if the name is a duplicate.
5871 * Callers must hold the rtnl semaphore. You may want
5872 * register_netdev() instead of this.
5875 * The locking appears insufficient to guarantee two parallel registers
5876 * will not get the same name.
5879 int register_netdevice(struct net_device *dev)
5882 struct net *net = dev_net(dev);
5884 BUG_ON(dev_boot_phase);
5889 /* When net_device's are persistent, this will be fatal. */
5890 BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
5893 spin_lock_init(&dev->addr_list_lock);
5894 netdev_set_addr_lockdep_class(dev);
5898 ret = dev_get_valid_name(net, dev, dev->name);
5902 /* Init, if this function is available */
5903 if (dev->netdev_ops->ndo_init) {
5904 ret = dev->netdev_ops->ndo_init(dev);
5912 if (((dev->hw_features | dev->features) &
5913 NETIF_F_HW_VLAN_CTAG_FILTER) &&
5914 (!dev->netdev_ops->ndo_vlan_rx_add_vid ||
5915 !dev->netdev_ops->ndo_vlan_rx_kill_vid)) {
5916 netdev_WARN(dev, "Buggy VLAN acceleration in driver!\n");
5923 dev->ifindex = dev_new_index(net);
5924 else if (__dev_get_by_index(net, dev->ifindex))
5927 if (dev->iflink == -1)
5928 dev->iflink = dev->ifindex;
5930 /* Transfer changeable features to wanted_features and enable
5931 * software offloads (GSO and GRO).
5933 dev->hw_features |= NETIF_F_SOFT_FEATURES;
5934 dev->features |= NETIF_F_SOFT_FEATURES;
5935 dev->wanted_features = dev->features & dev->hw_features;
5937 if (!(dev->flags & IFF_LOOPBACK)) {
5938 dev->hw_features |= NETIF_F_NOCACHE_COPY;
5941 /* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
5943 dev->vlan_features |= NETIF_F_HIGHDMA;
5945 /* Make NETIF_F_SG inheritable to tunnel devices.
5947 dev->hw_enc_features |= NETIF_F_SG;
5949 /* Make NETIF_F_SG inheritable to MPLS.
5951 dev->mpls_features |= NETIF_F_SG;
5953 ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
5954 ret = notifier_to_errno(ret);
5958 ret = netdev_register_kobject(dev);
5961 dev->reg_state = NETREG_REGISTERED;
5963 __netdev_update_features(dev);
5966 * Default initial state at registry is that the
5967 * device is present.
5970 set_bit(__LINK_STATE_PRESENT, &dev->state);
5972 linkwatch_init_dev(dev);
5974 dev_init_scheduler(dev);
5976 list_netdevice(dev);
5977 add_device_randomness(dev->dev_addr, dev->addr_len);
5979 /* If the device has permanent device address, driver should
5980 * set dev_addr and also addr_assign_type should be set to
5981 * NET_ADDR_PERM (default value).
5983 if (dev->addr_assign_type == NET_ADDR_PERM)
5984 memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);
5986 /* Notify protocols, that a new device appeared. */
5987 ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
5988 ret = notifier_to_errno(ret);
5990 rollback_registered(dev);
5991 dev->reg_state = NETREG_UNREGISTERED;
5994 * Prevent userspace races by waiting until the network
5995 * device is fully setup before sending notifications.
5997 if (!dev->rtnl_link_ops ||
5998 dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
5999 rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
6005 if (dev->netdev_ops->ndo_uninit)
6006 dev->netdev_ops->ndo_uninit(dev);
6009 EXPORT_SYMBOL(register_netdevice);
6012 * init_dummy_netdev - init a dummy network device for NAPI
6013 * @dev: device to init
6015 * This takes a network device structure and initialize the minimum
6016 * amount of fields so it can be used to schedule NAPI polls without
6017 * registering a full blown interface. This is to be used by drivers
6018 * that need to tie several hardware interfaces to a single NAPI
6019 * poll scheduler due to HW limitations.
6021 int init_dummy_netdev(struct net_device *dev)
6023 /* Clear everything. Note we don't initialize spinlocks
6024 * are they aren't supposed to be taken by any of the
6025 * NAPI code and this dummy netdev is supposed to be
6026 * only ever used for NAPI polls
6028 memset(dev, 0, sizeof(struct net_device));
6030 /* make sure we BUG if trying to hit standard
6031 * register/unregister code path
6033 dev->reg_state = NETREG_DUMMY;
6035 /* NAPI wants this */
6036 INIT_LIST_HEAD(&dev->napi_list);
6038 /* a dummy interface is started by default */
6039 set_bit(__LINK_STATE_PRESENT, &dev->state);
6040 set_bit(__LINK_STATE_START, &dev->state);
6042 /* Note : We dont allocate pcpu_refcnt for dummy devices,
6043 * because users of this 'device' dont need to change
6049 EXPORT_SYMBOL_GPL(init_dummy_netdev);
6053 * register_netdev - register a network device
6054 * @dev: device to register
6056 * Take a completed network device structure and add it to the kernel
6057 * interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
6058 * chain. 0 is returned on success. A negative errno code is returned
6059 * on a failure to set up the device, or if the name is a duplicate.
6061 * This is a wrapper around register_netdevice that takes the rtnl semaphore
6062 * and expands the device name if you passed a format string to
6065 int register_netdev(struct net_device *dev)
6070 err = register_netdevice(dev);
6074 EXPORT_SYMBOL(register_netdev);
6076 int netdev_refcnt_read(const struct net_device *dev)
6080 for_each_possible_cpu(i)
6081 refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
6084 EXPORT_SYMBOL(netdev_refcnt_read);
6087 * netdev_wait_allrefs - wait until all references are gone.
6088 * @dev: target net_device
6090 * This is called when unregistering network devices.
6092 * Any protocol or device that holds a reference should register
6093 * for netdevice notification, and cleanup and put back the
6094 * reference if they receive an UNREGISTER event.
6095 * We can get stuck here if buggy protocols don't correctly
6098 static void netdev_wait_allrefs(struct net_device *dev)
6100 unsigned long rebroadcast_time, warning_time;
6103 linkwatch_forget_dev(dev);
6105 rebroadcast_time = warning_time = jiffies;
6106 refcnt = netdev_refcnt_read(dev);
6108 while (refcnt != 0) {
6109 if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
6112 /* Rebroadcast unregister notification */
6113 call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
6119 call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
6120 if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
6122 /* We must not have linkwatch events
6123 * pending on unregister. If this
6124 * happens, we simply run the queue
6125 * unscheduled, resulting in a noop
6128 linkwatch_run_queue();
6133 rebroadcast_time = jiffies;
6138 refcnt = netdev_refcnt_read(dev);
6140 if (time_after(jiffies, warning_time + 10 * HZ)) {
6141 pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
6143 warning_time = jiffies;
6152 * register_netdevice(x1);
6153 * register_netdevice(x2);
6155 * unregister_netdevice(y1);
6156 * unregister_netdevice(y2);
6162 * We are invoked by rtnl_unlock().
6163 * This allows us to deal with problems:
6164 * 1) We can delete sysfs objects which invoke hotplug
6165 * without deadlocking with linkwatch via keventd.
6166 * 2) Since we run with the RTNL semaphore not held, we can sleep
6167 * safely in order to wait for the netdev refcnt to drop to zero.
6169 * We must not return until all unregister events added during
6170 * the interval the lock was held have been completed.
6172 void netdev_run_todo(void)
6174 struct list_head list;
6176 /* Snapshot list, allow later requests */
6177 list_replace_init(&net_todo_list, &list);
6182 /* Wait for rcu callbacks to finish before next phase */
6183 if (!list_empty(&list))
6186 while (!list_empty(&list)) {
6187 struct net_device *dev
6188 = list_first_entry(&list, struct net_device, todo_list);
6189 list_del(&dev->todo_list);
6192 call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
6195 if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
6196 pr_err("network todo '%s' but state %d\n",
6197 dev->name, dev->reg_state);
6202 dev->reg_state = NETREG_UNREGISTERED;
6204 on_each_cpu(flush_backlog, dev, 1);
6206 netdev_wait_allrefs(dev);
6209 BUG_ON(netdev_refcnt_read(dev));
6210 WARN_ON(rcu_access_pointer(dev->ip_ptr));
6211 WARN_ON(rcu_access_pointer(dev->ip6_ptr));
6212 WARN_ON(dev->dn_ptr);
6214 if (dev->destructor)
6215 dev->destructor(dev);
6217 /* Report a network device has been unregistered */
6219 dev_net(dev)->dev_unreg_count--;
6221 wake_up(&netdev_unregistering_wq);
6223 /* Free network device */
6224 kobject_put(&dev->dev.kobj);
6228 /* Convert net_device_stats to rtnl_link_stats64. They have the same
6229 * fields in the same order, with only the type differing.
6231 void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
6232 const struct net_device_stats *netdev_stats)
6234 #if BITS_PER_LONG == 64
6235 BUILD_BUG_ON(sizeof(*stats64) != sizeof(*netdev_stats));
6236 memcpy(stats64, netdev_stats, sizeof(*stats64));
6238 size_t i, n = sizeof(*stats64) / sizeof(u64);
6239 const unsigned long *src = (const unsigned long *)netdev_stats;
6240 u64 *dst = (u64 *)stats64;
6242 BUILD_BUG_ON(sizeof(*netdev_stats) / sizeof(unsigned long) !=
6243 sizeof(*stats64) / sizeof(u64));
6244 for (i = 0; i < n; i++)
6248 EXPORT_SYMBOL(netdev_stats_to_stats64);
6251 * dev_get_stats - get network device statistics
6252 * @dev: device to get statistics from
6253 * @storage: place to store stats
6255 * Get network statistics from device. Return @storage.
6256 * The device driver may provide its own method by setting
6257 * dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
6258 * otherwise the internal statistics structure is used.
6260 struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
6261 struct rtnl_link_stats64 *storage)
6263 const struct net_device_ops *ops = dev->netdev_ops;
6265 if (ops->ndo_get_stats64) {
6266 memset(storage, 0, sizeof(*storage));
6267 ops->ndo_get_stats64(dev, storage);
6268 } else if (ops->ndo_get_stats) {
6269 netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
6271 netdev_stats_to_stats64(storage, &dev->stats);
6273 storage->rx_dropped += atomic_long_read(&dev->rx_dropped);
6274 storage->tx_dropped += atomic_long_read(&dev->tx_dropped);
6277 EXPORT_SYMBOL(dev_get_stats);
6279 struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
6281 struct netdev_queue *queue = dev_ingress_queue(dev);
6283 #ifdef CONFIG_NET_CLS_ACT
6286 queue = kzalloc(sizeof(*queue), GFP_KERNEL);
6289 netdev_init_one_queue(dev, queue, NULL);
6290 queue->qdisc = &noop_qdisc;
6291 queue->qdisc_sleeping = &noop_qdisc;
6292 rcu_assign_pointer(dev->ingress_queue, queue);
6297 static const struct ethtool_ops default_ethtool_ops;
6299 void netdev_set_default_ethtool_ops(struct net_device *dev,
6300 const struct ethtool_ops *ops)
6302 if (dev->ethtool_ops == &default_ethtool_ops)
6303 dev->ethtool_ops = ops;
6305 EXPORT_SYMBOL_GPL(netdev_set_default_ethtool_ops);
6307 void netdev_freemem(struct net_device *dev)
6309 char *addr = (char *)dev - dev->padded;
6311 if (is_vmalloc_addr(addr))
6318 * alloc_netdev_mqs - allocate network device
6319 * @sizeof_priv: size of private data to allocate space for
6320 * @name: device name format string
6321 * @setup: callback to initialize device
6322 * @txqs: the number of TX subqueues to allocate
6323 * @rxqs: the number of RX subqueues to allocate
6325 * Allocates a struct net_device with private data area for driver use
6326 * and performs basic initialization. Also allocates subqueue structs
6327 * for each queue on the device.
6329 struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
6330 void (*setup)(struct net_device *),
6331 unsigned int txqs, unsigned int rxqs)
6333 struct net_device *dev;
6335 struct net_device *p;
6337 BUG_ON(strlen(name) >= sizeof(dev->name));
6340 pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
6346 pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
6351 alloc_size = sizeof(struct net_device);
6353 /* ensure 32-byte alignment of private area */
6354 alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
6355 alloc_size += sizeof_priv;
6357 /* ensure 32-byte alignment of whole construct */
6358 alloc_size += NETDEV_ALIGN - 1;
6360 p = kzalloc(alloc_size, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
6362 p = vzalloc(alloc_size);
6366 dev = PTR_ALIGN(p, NETDEV_ALIGN);
6367 dev->padded = (char *)dev - (char *)p;
6369 dev->pcpu_refcnt = alloc_percpu(int);
6370 if (!dev->pcpu_refcnt)
6373 if (dev_addr_init(dev))
6379 dev_net_set(dev, &init_net);
6381 dev->gso_max_size = GSO_MAX_SIZE;
6382 dev->gso_max_segs = GSO_MAX_SEGS;
6384 INIT_LIST_HEAD(&dev->napi_list);
6385 INIT_LIST_HEAD(&dev->unreg_list);
6386 INIT_LIST_HEAD(&dev->close_list);
6387 INIT_LIST_HEAD(&dev->link_watch_list);
6388 INIT_LIST_HEAD(&dev->adj_list.upper);
6389 INIT_LIST_HEAD(&dev->adj_list.lower);
6390 INIT_LIST_HEAD(&dev->all_adj_list.upper);
6391 INIT_LIST_HEAD(&dev->all_adj_list.lower);
6392 dev->priv_flags = IFF_XMIT_DST_RELEASE;
6395 dev->num_tx_queues = txqs;
6396 dev->real_num_tx_queues = txqs;
6397 if (netif_alloc_netdev_queues(dev))
6401 dev->num_rx_queues = rxqs;
6402 dev->real_num_rx_queues = rxqs;
6403 if (netif_alloc_rx_queues(dev))
6407 strcpy(dev->name, name);
6408 dev->group = INIT_NETDEV_GROUP;
6409 if (!dev->ethtool_ops)
6410 dev->ethtool_ops = &default_ethtool_ops;
6418 free_percpu(dev->pcpu_refcnt);
6419 netif_free_tx_queues(dev);
6425 netdev_freemem(dev);
6428 EXPORT_SYMBOL(alloc_netdev_mqs);
6431 * free_netdev - free network device
6434 * This function does the last stage of destroying an allocated device
6435 * interface. The reference to the device object is released.
6436 * If this is the last reference then it will be freed.
6438 void free_netdev(struct net_device *dev)
6440 struct napi_struct *p, *n;
6442 release_net(dev_net(dev));
6444 netif_free_tx_queues(dev);
6449 kfree(rcu_dereference_protected(dev->ingress_queue, 1));
6451 /* Flush device addresses */
6452 dev_addr_flush(dev);
6454 list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
6457 free_percpu(dev->pcpu_refcnt);
6458 dev->pcpu_refcnt = NULL;
6460 /* Compatibility with error handling in drivers */
6461 if (dev->reg_state == NETREG_UNINITIALIZED) {
6462 netdev_freemem(dev);
6466 BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
6467 dev->reg_state = NETREG_RELEASED;
6469 /* will free via device release */
6470 put_device(&dev->dev);
6472 EXPORT_SYMBOL(free_netdev);
6475 * synchronize_net - Synchronize with packet receive processing
6477 * Wait for packets currently being received to be done.
6478 * Does not block later packets from starting.
6480 void synchronize_net(void)
6483 if (rtnl_is_locked())
6484 synchronize_rcu_expedited();
6488 EXPORT_SYMBOL(synchronize_net);
6491 * unregister_netdevice_queue - remove device from the kernel
6495 * This function shuts down a device interface and removes it
6496 * from the kernel tables.
6497 * If head not NULL, device is queued to be unregistered later.
6499 * Callers must hold the rtnl semaphore. You may want
6500 * unregister_netdev() instead of this.
6503 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
6508 list_move_tail(&dev->unreg_list, head);
6510 rollback_registered(dev);
6511 /* Finish processing unregister after unlock */
6515 EXPORT_SYMBOL(unregister_netdevice_queue);
6518 * unregister_netdevice_many - unregister many devices
6519 * @head: list of devices
6521 void unregister_netdevice_many(struct list_head *head)
6523 struct net_device *dev;
6525 if (!list_empty(head)) {
6526 rollback_registered_many(head);
6527 list_for_each_entry(dev, head, unreg_list)
6531 EXPORT_SYMBOL(unregister_netdevice_many);
6534 * unregister_netdev - remove device from the kernel
6537 * This function shuts down a device interface and removes it
6538 * from the kernel tables.
6540 * This is just a wrapper for unregister_netdevice that takes
6541 * the rtnl semaphore. In general you want to use this and not
6542 * unregister_netdevice.
6544 void unregister_netdev(struct net_device *dev)
6547 unregister_netdevice(dev);
6550 EXPORT_SYMBOL(unregister_netdev);
6553 * dev_change_net_namespace - move device to different nethost namespace
6555 * @net: network namespace
6556 * @pat: If not NULL name pattern to try if the current device name
6557 * is already taken in the destination network namespace.
6559 * This function shuts down a device interface and moves it
6560 * to a new network namespace. On success 0 is returned, on
6561 * a failure a netagive errno code is returned.
6563 * Callers must hold the rtnl semaphore.
6566 int dev_change_net_namespace(struct net_device *dev, struct net *net, const char *pat)
6572 /* Don't allow namespace local devices to be moved. */
6574 if (dev->features & NETIF_F_NETNS_LOCAL)
6577 /* Ensure the device has been registrered */
6578 if (dev->reg_state != NETREG_REGISTERED)
6581 /* Get out if there is nothing todo */
6583 if (net_eq(dev_net(dev), net))
6586 /* Pick the destination device name, and ensure
6587 * we can use it in the destination network namespace.
6590 if (__dev_get_by_name(net, dev->name)) {
6591 /* We get here if we can't use the current device name */
6594 if (dev_get_valid_name(net, dev, pat) < 0)
6599 * And now a mini version of register_netdevice unregister_netdevice.
6602 /* If device is running close it first. */
6605 /* And unlink it from device chain */
6607 unlist_netdevice(dev);
6611 /* Shutdown queueing discipline. */
6614 /* Notify protocols, that we are about to destroy
6615 this device. They should clean all the things.
6617 Note that dev->reg_state stays at NETREG_REGISTERED.
6618 This is wanted because this way 8021q and macvlan know
6619 the device is just moving and can keep their slaves up.
6621 call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
6623 call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
6624 rtmsg_ifinfo(RTM_DELLINK, dev, ~0U, GFP_KERNEL);
6627 * Flush the unicast and multicast chains
6632 /* Send a netdev-removed uevent to the old namespace */
6633 kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);
6635 /* Actually switch the network namespace */
6636 dev_net_set(dev, net);
6638 /* If there is an ifindex conflict assign a new one */
6639 if (__dev_get_by_index(net, dev->ifindex)) {
6640 int iflink = (dev->iflink == dev->ifindex);
6641 dev->ifindex = dev_new_index(net);
6643 dev->iflink = dev->ifindex;
6646 /* Send a netdev-add uevent to the new namespace */
6647 kobject_uevent(&dev->dev.kobj, KOBJ_ADD);
6649 /* Fixup kobjects */
6650 err = device_rename(&dev->dev, dev->name);
6653 /* Add the device back in the hashes */
6654 list_netdevice(dev);
6656 /* Notify protocols, that a new device appeared. */
6657 call_netdevice_notifiers(NETDEV_REGISTER, dev);
6660 * Prevent userspace races by waiting until the network
6661 * device is fully setup before sending notifications.
6663 rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
6670 EXPORT_SYMBOL_GPL(dev_change_net_namespace);
6672 static int dev_cpu_callback(struct notifier_block *nfb,
6673 unsigned long action,
6676 struct sk_buff **list_skb;
6677 struct sk_buff *skb;
6678 unsigned int cpu, oldcpu = (unsigned long)ocpu;
6679 struct softnet_data *sd, *oldsd;
6681 if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
6684 local_irq_disable();
6685 cpu = smp_processor_id();
6686 sd = &per_cpu(softnet_data, cpu);
6687 oldsd = &per_cpu(softnet_data, oldcpu);
6689 /* Find end of our completion_queue. */
6690 list_skb = &sd->completion_queue;
6692 list_skb = &(*list_skb)->next;
6693 /* Append completion queue from offline CPU. */
6694 *list_skb = oldsd->completion_queue;
6695 oldsd->completion_queue = NULL;
6697 /* Append output queue from offline CPU. */
6698 if (oldsd->output_queue) {
6699 *sd->output_queue_tailp = oldsd->output_queue;
6700 sd->output_queue_tailp = oldsd->output_queue_tailp;
6701 oldsd->output_queue = NULL;
6702 oldsd->output_queue_tailp = &oldsd->output_queue;
6704 /* Append NAPI poll list from offline CPU. */
6705 if (!list_empty(&oldsd->poll_list)) {
6706 list_splice_init(&oldsd->poll_list, &sd->poll_list);
6707 raise_softirq_irqoff(NET_RX_SOFTIRQ);
6710 raise_softirq_irqoff(NET_TX_SOFTIRQ);
6713 /* Process offline CPU's input_pkt_queue */
6714 while ((skb = __skb_dequeue(&oldsd->process_queue))) {
6715 netif_rx_internal(skb);
6716 input_queue_head_incr(oldsd);
6718 while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) {
6719 netif_rx_internal(skb);
6720 input_queue_head_incr(oldsd);
6728 * netdev_increment_features - increment feature set by one
6729 * @all: current feature set
6730 * @one: new feature set
6731 * @mask: mask feature set
6733 * Computes a new feature set after adding a device with feature set
6734 * @one to the master device with current feature set @all. Will not
6735 * enable anything that is off in @mask. Returns the new feature set.
6737 netdev_features_t netdev_increment_features(netdev_features_t all,
6738 netdev_features_t one, netdev_features_t mask)
6740 if (mask & NETIF_F_GEN_CSUM)
6741 mask |= NETIF_F_ALL_CSUM;
6742 mask |= NETIF_F_VLAN_CHALLENGED;
6744 all |= one & (NETIF_F_ONE_FOR_ALL|NETIF_F_ALL_CSUM) & mask;
6745 all &= one | ~NETIF_F_ALL_FOR_ALL;
6747 /* If one device supports hw checksumming, set for all. */
6748 if (all & NETIF_F_GEN_CSUM)
6749 all &= ~(NETIF_F_ALL_CSUM & ~NETIF_F_GEN_CSUM);
6753 EXPORT_SYMBOL(netdev_increment_features);
6755 static struct hlist_head * __net_init netdev_create_hash(void)
6758 struct hlist_head *hash;
6760 hash = kmalloc(sizeof(*hash) * NETDEV_HASHENTRIES, GFP_KERNEL);
6762 for (i = 0; i < NETDEV_HASHENTRIES; i++)
6763 INIT_HLIST_HEAD(&hash[i]);
6768 /* Initialize per network namespace state */
6769 static int __net_init netdev_init(struct net *net)
6771 if (net != &init_net)
6772 INIT_LIST_HEAD(&net->dev_base_head);
6774 net->dev_name_head = netdev_create_hash();
6775 if (net->dev_name_head == NULL)
6778 net->dev_index_head = netdev_create_hash();
6779 if (net->dev_index_head == NULL)
6785 kfree(net->dev_name_head);
6791 * netdev_drivername - network driver for the device
6792 * @dev: network device
6794 * Determine network driver for device.
6796 const char *netdev_drivername(const struct net_device *dev)
6798 const struct device_driver *driver;
6799 const struct device *parent;
6800 const char *empty = "";
6802 parent = dev->dev.parent;
6806 driver = parent->driver;
6807 if (driver && driver->name)
6808 return driver->name;
6812 static int __netdev_printk(const char *level, const struct net_device *dev,
6813 struct va_format *vaf)
6817 if (dev && dev->dev.parent) {
6818 r = dev_printk_emit(level[1] - '0',
6821 dev_driver_string(dev->dev.parent),
6822 dev_name(dev->dev.parent),
6823 netdev_name(dev), vaf);
6825 r = printk("%s%s: %pV", level, netdev_name(dev), vaf);
6827 r = printk("%s(NULL net_device): %pV", level, vaf);
6833 int netdev_printk(const char *level, const struct net_device *dev,
6834 const char *format, ...)
6836 struct va_format vaf;
6840 va_start(args, format);
6845 r = __netdev_printk(level, dev, &vaf);
6851 EXPORT_SYMBOL(netdev_printk);
6853 #define define_netdev_printk_level(func, level) \
6854 int func(const struct net_device *dev, const char *fmt, ...) \
6857 struct va_format vaf; \
6860 va_start(args, fmt); \
6865 r = __netdev_printk(level, dev, &vaf); \
6871 EXPORT_SYMBOL(func);
6873 define_netdev_printk_level(netdev_emerg, KERN_EMERG);
6874 define_netdev_printk_level(netdev_alert, KERN_ALERT);
6875 define_netdev_printk_level(netdev_crit, KERN_CRIT);
6876 define_netdev_printk_level(netdev_err, KERN_ERR);
6877 define_netdev_printk_level(netdev_warn, KERN_WARNING);
6878 define_netdev_printk_level(netdev_notice, KERN_NOTICE);
6879 define_netdev_printk_level(netdev_info, KERN_INFO);
6881 static void __net_exit netdev_exit(struct net *net)
6883 kfree(net->dev_name_head);
6884 kfree(net->dev_index_head);
6887 static struct pernet_operations __net_initdata netdev_net_ops = {
6888 .init = netdev_init,
6889 .exit = netdev_exit,
6892 static void __net_exit default_device_exit(struct net *net)
6894 struct net_device *dev, *aux;
6896 * Push all migratable network devices back to the
6897 * initial network namespace
6900 for_each_netdev_safe(net, dev, aux) {
6902 char fb_name[IFNAMSIZ];
6904 /* Ignore unmoveable devices (i.e. loopback) */
6905 if (dev->features & NETIF_F_NETNS_LOCAL)
6908 /* Leave virtual devices for the generic cleanup */
6909 if (dev->rtnl_link_ops)
6912 /* Push remaining network devices to init_net */
6913 snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
6914 err = dev_change_net_namespace(dev, &init_net, fb_name);
6916 pr_emerg("%s: failed to move %s to init_net: %d\n",
6917 __func__, dev->name, err);
6924 static void __net_exit rtnl_lock_unregistering(struct list_head *net_list)
6926 /* Return with the rtnl_lock held when there are no network
6927 * devices unregistering in any network namespace in net_list.
6934 prepare_to_wait(&netdev_unregistering_wq, &wait,
6935 TASK_UNINTERRUPTIBLE);
6936 unregistering = false;
6938 list_for_each_entry(net, net_list, exit_list) {
6939 if (net->dev_unreg_count > 0) {
6940 unregistering = true;
6949 finish_wait(&netdev_unregistering_wq, &wait);
6952 static void __net_exit default_device_exit_batch(struct list_head *net_list)
6954 /* At exit all network devices most be removed from a network
6955 * namespace. Do this in the reverse order of registration.
6956 * Do this across as many network namespaces as possible to
6957 * improve batching efficiency.
6959 struct net_device *dev;
6961 LIST_HEAD(dev_kill_list);
6963 /* To prevent network device cleanup code from dereferencing
6964 * loopback devices or network devices that have been freed
6965 * wait here for all pending unregistrations to complete,
6966 * before unregistring the loopback device and allowing the
6967 * network namespace be freed.
6969 * The netdev todo list containing all network devices
6970 * unregistrations that happen in default_device_exit_batch
6971 * will run in the rtnl_unlock() at the end of
6972 * default_device_exit_batch.
6974 rtnl_lock_unregistering(net_list);
6975 list_for_each_entry(net, net_list, exit_list) {
6976 for_each_netdev_reverse(net, dev) {
6977 if (dev->rtnl_link_ops)
6978 dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
6980 unregister_netdevice_queue(dev, &dev_kill_list);
6983 unregister_netdevice_many(&dev_kill_list);
6984 list_del(&dev_kill_list);
6988 static struct pernet_operations __net_initdata default_device_ops = {
6989 .exit = default_device_exit,
6990 .exit_batch = default_device_exit_batch,
6994 * Initialize the DEV module. At boot time this walks the device list and
6995 * unhooks any devices that fail to initialise (normally hardware not
6996 * present) and leaves us with a valid list of present and active devices.
7001 * This is called single threaded during boot, so no need
7002 * to take the rtnl semaphore.
7004 static int __init net_dev_init(void)
7006 int i, rc = -ENOMEM;
7008 BUG_ON(!dev_boot_phase);
7010 if (dev_proc_init())
7013 if (netdev_kobject_init())
7016 INIT_LIST_HEAD(&ptype_all);
7017 for (i = 0; i < PTYPE_HASH_SIZE; i++)
7018 INIT_LIST_HEAD(&ptype_base[i]);
7020 INIT_LIST_HEAD(&offload_base);
7022 if (register_pernet_subsys(&netdev_net_ops))
7026 * Initialise the packet receive queues.
7029 for_each_possible_cpu(i) {
7030 struct softnet_data *sd = &per_cpu(softnet_data, i);
7032 skb_queue_head_init(&sd->input_pkt_queue);
7033 skb_queue_head_init(&sd->process_queue);
7034 INIT_LIST_HEAD(&sd->poll_list);
7035 sd->output_queue_tailp = &sd->output_queue;
7037 sd->csd.func = rps_trigger_softirq;
7042 sd->backlog.poll = process_backlog;
7043 sd->backlog.weight = weight_p;
7048 /* The loopback device is special if any other network devices
7049 * is present in a network namespace the loopback device must
7050 * be present. Since we now dynamically allocate and free the
7051 * loopback device ensure this invariant is maintained by
7052 * keeping the loopback device as the first device on the
7053 * list of network devices. Ensuring the loopback devices
7054 * is the first device that appears and the last network device
7057 if (register_pernet_device(&loopback_net_ops))
7060 if (register_pernet_device(&default_device_ops))
7063 open_softirq(NET_TX_SOFTIRQ, net_tx_action);
7064 open_softirq(NET_RX_SOFTIRQ, net_rx_action);
7066 hotcpu_notifier(dev_cpu_callback, 0);
7073 subsys_initcall(net_dev_init);