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>
133 #include "net-sysfs.h"
135 /* Instead of increasing this, you should create a hash table. */
136 #define MAX_GRO_SKBS 8
138 /* This should be increased if a protocol with a bigger head is added. */
139 #define GRO_MAX_HEAD (MAX_HEADER + 128)
141 static DEFINE_SPINLOCK(ptype_lock);
142 static DEFINE_SPINLOCK(offload_lock);
143 struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
144 struct list_head ptype_all __read_mostly; /* Taps */
145 static struct list_head offload_base __read_mostly;
148 * The @dev_base_head list is protected by @dev_base_lock and the rtnl
151 * Pure readers hold dev_base_lock for reading, or rcu_read_lock()
153 * Writers must hold the rtnl semaphore while they loop through the
154 * dev_base_head list, and hold dev_base_lock for writing when they do the
155 * actual updates. This allows pure readers to access the list even
156 * while a writer is preparing to update it.
158 * To put it another way, dev_base_lock is held for writing only to
159 * protect against pure readers; the rtnl semaphore provides the
160 * protection against other writers.
162 * See, for example usages, register_netdevice() and
163 * unregister_netdevice(), which must be called with the rtnl
166 DEFINE_RWLOCK(dev_base_lock);
167 EXPORT_SYMBOL(dev_base_lock);
169 seqcount_t devnet_rename_seq;
171 static inline void dev_base_seq_inc(struct net *net)
173 while (++net->dev_base_seq == 0);
176 static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
178 unsigned int hash = full_name_hash(name, strnlen(name, IFNAMSIZ));
180 return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
183 static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
185 return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
188 static inline void rps_lock(struct softnet_data *sd)
191 spin_lock(&sd->input_pkt_queue.lock);
195 static inline void rps_unlock(struct softnet_data *sd)
198 spin_unlock(&sd->input_pkt_queue.lock);
202 /* Device list insertion */
203 static int list_netdevice(struct net_device *dev)
205 struct net *net = dev_net(dev);
209 write_lock_bh(&dev_base_lock);
210 list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
211 hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
212 hlist_add_head_rcu(&dev->index_hlist,
213 dev_index_hash(net, dev->ifindex));
214 write_unlock_bh(&dev_base_lock);
216 dev_base_seq_inc(net);
221 /* Device list removal
222 * caller must respect a RCU grace period before freeing/reusing dev
224 static void unlist_netdevice(struct net_device *dev)
228 /* Unlink dev from the device chain */
229 write_lock_bh(&dev_base_lock);
230 list_del_rcu(&dev->dev_list);
231 hlist_del_rcu(&dev->name_hlist);
232 hlist_del_rcu(&dev->index_hlist);
233 write_unlock_bh(&dev_base_lock);
235 dev_base_seq_inc(dev_net(dev));
242 static RAW_NOTIFIER_HEAD(netdev_chain);
245 * Device drivers call our routines to queue packets here. We empty the
246 * queue in the local softnet handler.
249 DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
250 EXPORT_PER_CPU_SYMBOL(softnet_data);
252 #ifdef CONFIG_LOCKDEP
254 * register_netdevice() inits txq->_xmit_lock and sets lockdep class
255 * according to dev->type
257 static const unsigned short netdev_lock_type[] =
258 {ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
259 ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
260 ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
261 ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
262 ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
263 ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
264 ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
265 ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
266 ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
267 ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
268 ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
269 ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
270 ARPHRD_FCFABRIC, ARPHRD_IEEE80211, ARPHRD_IEEE80211_PRISM,
271 ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET, ARPHRD_PHONET_PIPE,
272 ARPHRD_IEEE802154, ARPHRD_VOID, ARPHRD_NONE};
274 static const char *const netdev_lock_name[] =
275 {"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
276 "_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
277 "_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
278 "_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
279 "_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
280 "_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
281 "_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
282 "_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
283 "_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
284 "_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
285 "_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
286 "_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
287 "_xmit_FCFABRIC", "_xmit_IEEE80211", "_xmit_IEEE80211_PRISM",
288 "_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET", "_xmit_PHONET_PIPE",
289 "_xmit_IEEE802154", "_xmit_VOID", "_xmit_NONE"};
291 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
292 static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
294 static inline unsigned short netdev_lock_pos(unsigned short dev_type)
298 for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
299 if (netdev_lock_type[i] == dev_type)
301 /* the last key is used by default */
302 return ARRAY_SIZE(netdev_lock_type) - 1;
305 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
306 unsigned short dev_type)
310 i = netdev_lock_pos(dev_type);
311 lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
312 netdev_lock_name[i]);
315 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
319 i = netdev_lock_pos(dev->type);
320 lockdep_set_class_and_name(&dev->addr_list_lock,
321 &netdev_addr_lock_key[i],
322 netdev_lock_name[i]);
325 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
326 unsigned short dev_type)
329 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
334 /*******************************************************************************
336 Protocol management and registration routines
338 *******************************************************************************/
341 * Add a protocol ID to the list. Now that the input handler is
342 * smarter we can dispense with all the messy stuff that used to be
345 * BEWARE!!! Protocol handlers, mangling input packets,
346 * MUST BE last in hash buckets and checking protocol handlers
347 * MUST start from promiscuous ptype_all chain in net_bh.
348 * It is true now, do not change it.
349 * Explanation follows: if protocol handler, mangling packet, will
350 * be the first on list, it is not able to sense, that packet
351 * is cloned and should be copied-on-write, so that it will
352 * change it and subsequent readers will get broken packet.
356 static inline struct list_head *ptype_head(const struct packet_type *pt)
358 if (pt->type == htons(ETH_P_ALL))
361 return &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
365 * dev_add_pack - add packet handler
366 * @pt: packet type declaration
368 * Add a protocol handler to the networking stack. The passed &packet_type
369 * is linked into kernel lists and may not be freed until it has been
370 * removed from the kernel lists.
372 * This call does not sleep therefore it can not
373 * guarantee all CPU's that are in middle of receiving packets
374 * will see the new packet type (until the next received packet).
377 void dev_add_pack(struct packet_type *pt)
379 struct list_head *head = ptype_head(pt);
381 spin_lock(&ptype_lock);
382 list_add_rcu(&pt->list, head);
383 spin_unlock(&ptype_lock);
385 EXPORT_SYMBOL(dev_add_pack);
388 * __dev_remove_pack - remove packet handler
389 * @pt: packet type declaration
391 * Remove a protocol handler that was previously added to the kernel
392 * protocol handlers by dev_add_pack(). The passed &packet_type is removed
393 * from the kernel lists and can be freed or reused once this function
396 * The packet type might still be in use by receivers
397 * and must not be freed until after all the CPU's have gone
398 * through a quiescent state.
400 void __dev_remove_pack(struct packet_type *pt)
402 struct list_head *head = ptype_head(pt);
403 struct packet_type *pt1;
405 spin_lock(&ptype_lock);
407 list_for_each_entry(pt1, head, list) {
409 list_del_rcu(&pt->list);
414 pr_warn("dev_remove_pack: %p not found\n", pt);
416 spin_unlock(&ptype_lock);
418 EXPORT_SYMBOL(__dev_remove_pack);
421 * dev_remove_pack - remove packet handler
422 * @pt: packet type declaration
424 * Remove a protocol handler that was previously added to the kernel
425 * protocol handlers by dev_add_pack(). The passed &packet_type is removed
426 * from the kernel lists and can be freed or reused once this function
429 * This call sleeps to guarantee that no CPU is looking at the packet
432 void dev_remove_pack(struct packet_type *pt)
434 __dev_remove_pack(pt);
438 EXPORT_SYMBOL(dev_remove_pack);
442 * dev_add_offload - register offload handlers
443 * @po: protocol offload declaration
445 * Add protocol offload handlers to the networking stack. The passed
446 * &proto_offload is linked into kernel lists and may not be freed until
447 * it has been removed from the kernel lists.
449 * This call does not sleep therefore it can not
450 * guarantee all CPU's that are in middle of receiving packets
451 * will see the new offload handlers (until the next received packet).
453 void dev_add_offload(struct packet_offload *po)
455 struct list_head *head = &offload_base;
457 spin_lock(&offload_lock);
458 list_add_rcu(&po->list, head);
459 spin_unlock(&offload_lock);
461 EXPORT_SYMBOL(dev_add_offload);
464 * __dev_remove_offload - remove offload handler
465 * @po: packet offload declaration
467 * Remove a protocol offload handler that was previously added to the
468 * kernel offload handlers by dev_add_offload(). The passed &offload_type
469 * is removed from the kernel lists and can be freed or reused once this
472 * The packet type might still be in use by receivers
473 * and must not be freed until after all the CPU's have gone
474 * through a quiescent state.
476 void __dev_remove_offload(struct packet_offload *po)
478 struct list_head *head = &offload_base;
479 struct packet_offload *po1;
481 spin_lock(&offload_lock);
483 list_for_each_entry(po1, head, list) {
485 list_del_rcu(&po->list);
490 pr_warn("dev_remove_offload: %p not found\n", po);
492 spin_unlock(&offload_lock);
494 EXPORT_SYMBOL(__dev_remove_offload);
497 * dev_remove_offload - remove packet offload handler
498 * @po: packet offload declaration
500 * Remove a packet offload handler that was previously added to the kernel
501 * offload handlers by dev_add_offload(). The passed &offload_type is
502 * removed from the kernel lists and can be freed or reused once this
505 * This call sleeps to guarantee that no CPU is looking at the packet
508 void dev_remove_offload(struct packet_offload *po)
510 __dev_remove_offload(po);
514 EXPORT_SYMBOL(dev_remove_offload);
516 /******************************************************************************
518 Device Boot-time Settings Routines
520 *******************************************************************************/
522 /* Boot time configuration table */
523 static struct netdev_boot_setup dev_boot_setup[NETDEV_BOOT_SETUP_MAX];
526 * netdev_boot_setup_add - add new setup entry
527 * @name: name of the device
528 * @map: configured settings for the device
530 * Adds new setup entry to the dev_boot_setup list. The function
531 * returns 0 on error and 1 on success. This is a generic routine to
534 static int netdev_boot_setup_add(char *name, struct ifmap *map)
536 struct netdev_boot_setup *s;
540 for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
541 if (s[i].name[0] == '\0' || s[i].name[0] == ' ') {
542 memset(s[i].name, 0, sizeof(s[i].name));
543 strlcpy(s[i].name, name, IFNAMSIZ);
544 memcpy(&s[i].map, map, sizeof(s[i].map));
549 return i >= NETDEV_BOOT_SETUP_MAX ? 0 : 1;
553 * netdev_boot_setup_check - check boot time settings
554 * @dev: the netdevice
556 * Check boot time settings for the device.
557 * The found settings are set for the device to be used
558 * later in the device probing.
559 * Returns 0 if no settings found, 1 if they are.
561 int netdev_boot_setup_check(struct net_device *dev)
563 struct netdev_boot_setup *s = dev_boot_setup;
566 for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
567 if (s[i].name[0] != '\0' && s[i].name[0] != ' ' &&
568 !strcmp(dev->name, s[i].name)) {
569 dev->irq = s[i].map.irq;
570 dev->base_addr = s[i].map.base_addr;
571 dev->mem_start = s[i].map.mem_start;
572 dev->mem_end = s[i].map.mem_end;
578 EXPORT_SYMBOL(netdev_boot_setup_check);
582 * netdev_boot_base - get address from boot time settings
583 * @prefix: prefix for network device
584 * @unit: id for network device
586 * Check boot time settings for the base address of device.
587 * The found settings are set for the device to be used
588 * later in the device probing.
589 * Returns 0 if no settings found.
591 unsigned long netdev_boot_base(const char *prefix, int unit)
593 const struct netdev_boot_setup *s = dev_boot_setup;
597 sprintf(name, "%s%d", prefix, unit);
600 * If device already registered then return base of 1
601 * to indicate not to probe for this interface
603 if (__dev_get_by_name(&init_net, name))
606 for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++)
607 if (!strcmp(name, s[i].name))
608 return s[i].map.base_addr;
613 * Saves at boot time configured settings for any netdevice.
615 int __init netdev_boot_setup(char *str)
620 str = get_options(str, ARRAY_SIZE(ints), ints);
625 memset(&map, 0, sizeof(map));
629 map.base_addr = ints[2];
631 map.mem_start = ints[3];
633 map.mem_end = ints[4];
635 /* Add new entry to the list */
636 return netdev_boot_setup_add(str, &map);
639 __setup("netdev=", netdev_boot_setup);
641 /*******************************************************************************
643 Device Interface Subroutines
645 *******************************************************************************/
648 * __dev_get_by_name - find a device by its name
649 * @net: the applicable net namespace
650 * @name: name to find
652 * Find an interface by name. Must be called under RTNL semaphore
653 * or @dev_base_lock. If the name is found a pointer to the device
654 * is returned. If the name is not found then %NULL is returned. The
655 * reference counters are not incremented so the caller must be
656 * careful with locks.
659 struct net_device *__dev_get_by_name(struct net *net, const char *name)
661 struct hlist_node *p;
662 struct net_device *dev;
663 struct hlist_head *head = dev_name_hash(net, name);
665 hlist_for_each_entry(dev, p, head, name_hlist)
666 if (!strncmp(dev->name, name, IFNAMSIZ))
671 EXPORT_SYMBOL(__dev_get_by_name);
674 * dev_get_by_name_rcu - find a device by its name
675 * @net: the applicable net namespace
676 * @name: name to find
678 * Find an interface by name.
679 * If the name is found a pointer to the device is returned.
680 * If the name is not found then %NULL is returned.
681 * The reference counters are not incremented so the caller must be
682 * careful with locks. The caller must hold RCU lock.
685 struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
687 struct hlist_node *p;
688 struct net_device *dev;
689 struct hlist_head *head = dev_name_hash(net, name);
691 hlist_for_each_entry_rcu(dev, p, head, name_hlist)
692 if (!strncmp(dev->name, name, IFNAMSIZ))
697 EXPORT_SYMBOL(dev_get_by_name_rcu);
700 * dev_get_by_name - find a device by its name
701 * @net: the applicable net namespace
702 * @name: name to find
704 * Find an interface by name. This can be called from any
705 * context and does its own locking. The returned handle has
706 * the usage count incremented and the caller must use dev_put() to
707 * release it when it is no longer needed. %NULL is returned if no
708 * matching device is found.
711 struct net_device *dev_get_by_name(struct net *net, const char *name)
713 struct net_device *dev;
716 dev = dev_get_by_name_rcu(net, name);
722 EXPORT_SYMBOL(dev_get_by_name);
725 * __dev_get_by_index - find a device by its ifindex
726 * @net: the applicable net namespace
727 * @ifindex: index of device
729 * Search for an interface by index. Returns %NULL if the device
730 * is not found or a pointer to the device. The device has not
731 * had its reference counter increased so the caller must be careful
732 * about locking. The caller must hold either the RTNL semaphore
736 struct net_device *__dev_get_by_index(struct net *net, int ifindex)
738 struct hlist_node *p;
739 struct net_device *dev;
740 struct hlist_head *head = dev_index_hash(net, ifindex);
742 hlist_for_each_entry(dev, p, head, index_hlist)
743 if (dev->ifindex == ifindex)
748 EXPORT_SYMBOL(__dev_get_by_index);
751 * dev_get_by_index_rcu - find a device by its ifindex
752 * @net: the applicable net namespace
753 * @ifindex: index of device
755 * Search for an interface by index. Returns %NULL if the device
756 * is not found or a pointer to the device. The device has not
757 * had its reference counter increased so the caller must be careful
758 * about locking. The caller must hold RCU lock.
761 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
763 struct hlist_node *p;
764 struct net_device *dev;
765 struct hlist_head *head = dev_index_hash(net, ifindex);
767 hlist_for_each_entry_rcu(dev, p, head, index_hlist)
768 if (dev->ifindex == ifindex)
773 EXPORT_SYMBOL(dev_get_by_index_rcu);
777 * dev_get_by_index - find a device by its ifindex
778 * @net: the applicable net namespace
779 * @ifindex: index of device
781 * Search for an interface by index. Returns NULL if the device
782 * is not found or a pointer to the device. The device returned has
783 * had a reference added and the pointer is safe until the user calls
784 * dev_put to indicate they have finished with it.
787 struct net_device *dev_get_by_index(struct net *net, int ifindex)
789 struct net_device *dev;
792 dev = dev_get_by_index_rcu(net, ifindex);
798 EXPORT_SYMBOL(dev_get_by_index);
801 * dev_getbyhwaddr_rcu - find a device by its hardware address
802 * @net: the applicable net namespace
803 * @type: media type of device
804 * @ha: hardware address
806 * Search for an interface by MAC address. Returns NULL if the device
807 * is not found or a pointer to the device.
808 * The caller must hold RCU or RTNL.
809 * The returned device has not had its ref count increased
810 * and the caller must therefore be careful about locking
814 struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
817 struct net_device *dev;
819 for_each_netdev_rcu(net, dev)
820 if (dev->type == type &&
821 !memcmp(dev->dev_addr, ha, dev->addr_len))
826 EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
828 struct net_device *__dev_getfirstbyhwtype(struct net *net, unsigned short type)
830 struct net_device *dev;
833 for_each_netdev(net, dev)
834 if (dev->type == type)
839 EXPORT_SYMBOL(__dev_getfirstbyhwtype);
841 struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
843 struct net_device *dev, *ret = NULL;
846 for_each_netdev_rcu(net, dev)
847 if (dev->type == type) {
855 EXPORT_SYMBOL(dev_getfirstbyhwtype);
858 * dev_get_by_flags_rcu - find any device with given flags
859 * @net: the applicable net namespace
860 * @if_flags: IFF_* values
861 * @mask: bitmask of bits in if_flags to check
863 * Search for any interface with the given flags. Returns NULL if a device
864 * is not found or a pointer to the device. Must be called inside
865 * rcu_read_lock(), and result refcount is unchanged.
868 struct net_device *dev_get_by_flags_rcu(struct net *net, unsigned short if_flags,
871 struct net_device *dev, *ret;
874 for_each_netdev_rcu(net, dev) {
875 if (((dev->flags ^ if_flags) & mask) == 0) {
882 EXPORT_SYMBOL(dev_get_by_flags_rcu);
885 * dev_valid_name - check if name is okay for network device
888 * Network device names need to be valid file names to
889 * to allow sysfs to work. We also disallow any kind of
892 bool dev_valid_name(const char *name)
896 if (strlen(name) >= IFNAMSIZ)
898 if (!strcmp(name, ".") || !strcmp(name, ".."))
902 if (*name == '/' || isspace(*name))
908 EXPORT_SYMBOL(dev_valid_name);
911 * __dev_alloc_name - allocate a name for a device
912 * @net: network namespace to allocate the device name in
913 * @name: name format string
914 * @buf: scratch buffer and result name string
916 * Passed a format string - eg "lt%d" it will try and find a suitable
917 * id. It scans list of devices to build up a free map, then chooses
918 * the first empty slot. The caller must hold the dev_base or rtnl lock
919 * while allocating the name and adding the device in order to avoid
921 * Limited to bits_per_byte * page size devices (ie 32K on most platforms).
922 * Returns the number of the unit assigned or a negative errno code.
925 static int __dev_alloc_name(struct net *net, const char *name, char *buf)
929 const int max_netdevices = 8*PAGE_SIZE;
930 unsigned long *inuse;
931 struct net_device *d;
933 p = strnchr(name, IFNAMSIZ-1, '%');
936 * Verify the string as this thing may have come from
937 * the user. There must be either one "%d" and no other "%"
940 if (p[1] != 'd' || strchr(p + 2, '%'))
943 /* Use one page as a bit array of possible slots */
944 inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
948 for_each_netdev(net, d) {
949 if (!sscanf(d->name, name, &i))
951 if (i < 0 || i >= max_netdevices)
954 /* avoid cases where sscanf is not exact inverse of printf */
955 snprintf(buf, IFNAMSIZ, name, i);
956 if (!strncmp(buf, d->name, IFNAMSIZ))
960 i = find_first_zero_bit(inuse, max_netdevices);
961 free_page((unsigned long) inuse);
965 snprintf(buf, IFNAMSIZ, name, i);
966 if (!__dev_get_by_name(net, buf))
969 /* It is possible to run out of possible slots
970 * when the name is long and there isn't enough space left
971 * for the digits, or if all bits are used.
977 * dev_alloc_name - allocate a name for a device
979 * @name: name format string
981 * Passed a format string - eg "lt%d" it will try and find a suitable
982 * id. It scans list of devices to build up a free map, then chooses
983 * the first empty slot. The caller must hold the dev_base or rtnl lock
984 * while allocating the name and adding the device in order to avoid
986 * Limited to bits_per_byte * page size devices (ie 32K on most platforms).
987 * Returns the number of the unit assigned or a negative errno code.
990 int dev_alloc_name(struct net_device *dev, const char *name)
996 BUG_ON(!dev_net(dev));
998 ret = __dev_alloc_name(net, name, buf);
1000 strlcpy(dev->name, buf, IFNAMSIZ);
1003 EXPORT_SYMBOL(dev_alloc_name);
1005 static int dev_alloc_name_ns(struct net *net,
1006 struct net_device *dev,
1012 ret = __dev_alloc_name(net, name, buf);
1014 strlcpy(dev->name, buf, IFNAMSIZ);
1018 static int dev_get_valid_name(struct net *net,
1019 struct net_device *dev,
1024 if (!dev_valid_name(name))
1027 if (strchr(name, '%'))
1028 return dev_alloc_name_ns(net, dev, name);
1029 else if (__dev_get_by_name(net, name))
1031 else if (dev->name != name)
1032 strlcpy(dev->name, name, IFNAMSIZ);
1038 * dev_change_name - change name of a device
1040 * @newname: name (or format string) must be at least IFNAMSIZ
1042 * Change name of a device, can pass format strings "eth%d".
1045 int dev_change_name(struct net_device *dev, const char *newname)
1047 char oldname[IFNAMSIZ];
1053 BUG_ON(!dev_net(dev));
1056 if (dev->flags & IFF_UP)
1059 write_seqcount_begin(&devnet_rename_seq);
1061 if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
1062 write_seqcount_end(&devnet_rename_seq);
1066 memcpy(oldname, dev->name, IFNAMSIZ);
1068 err = dev_get_valid_name(net, dev, newname);
1070 write_seqcount_end(&devnet_rename_seq);
1075 ret = device_rename(&dev->dev, dev->name);
1077 memcpy(dev->name, oldname, IFNAMSIZ);
1078 write_seqcount_end(&devnet_rename_seq);
1082 write_seqcount_end(&devnet_rename_seq);
1084 write_lock_bh(&dev_base_lock);
1085 hlist_del_rcu(&dev->name_hlist);
1086 write_unlock_bh(&dev_base_lock);
1090 write_lock_bh(&dev_base_lock);
1091 hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name));
1092 write_unlock_bh(&dev_base_lock);
1094 ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1095 ret = notifier_to_errno(ret);
1098 /* err >= 0 after dev_alloc_name() or stores the first errno */
1101 write_seqcount_begin(&devnet_rename_seq);
1102 memcpy(dev->name, oldname, IFNAMSIZ);
1105 pr_err("%s: name change rollback failed: %d\n",
1114 * dev_set_alias - change ifalias of a device
1116 * @alias: name up to IFALIASZ
1117 * @len: limit of bytes to copy from info
1119 * Set ifalias for a device,
1121 int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
1127 if (len >= IFALIASZ)
1131 kfree(dev->ifalias);
1132 dev->ifalias = NULL;
1136 new_ifalias = krealloc(dev->ifalias, len + 1, GFP_KERNEL);
1139 dev->ifalias = new_ifalias;
1141 strlcpy(dev->ifalias, alias, len+1);
1147 * netdev_features_change - device changes features
1148 * @dev: device to cause notification
1150 * Called to indicate a device has changed features.
1152 void netdev_features_change(struct net_device *dev)
1154 call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1156 EXPORT_SYMBOL(netdev_features_change);
1159 * netdev_state_change - device changes state
1160 * @dev: device to cause notification
1162 * Called to indicate a device has changed state. This function calls
1163 * the notifier chains for netdev_chain and sends a NEWLINK message
1164 * to the routing socket.
1166 void netdev_state_change(struct net_device *dev)
1168 if (dev->flags & IFF_UP) {
1169 call_netdevice_notifiers(NETDEV_CHANGE, dev);
1170 rtmsg_ifinfo(RTM_NEWLINK, dev, 0);
1173 EXPORT_SYMBOL(netdev_state_change);
1176 * netdev_notify_peers - notify network peers about existence of @dev
1177 * @dev: network device
1179 * Generate traffic such that interested network peers are aware of
1180 * @dev, such as by generating a gratuitous ARP. This may be used when
1181 * a device wants to inform the rest of the network about some sort of
1182 * reconfiguration such as a failover event or virtual machine
1185 void netdev_notify_peers(struct net_device *dev)
1188 call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
1191 EXPORT_SYMBOL(netdev_notify_peers);
1193 static int __dev_open(struct net_device *dev)
1195 const struct net_device_ops *ops = dev->netdev_ops;
1200 if (!netif_device_present(dev))
1203 /* Block netpoll from trying to do any rx path servicing.
1204 * If we don't do this there is a chance ndo_poll_controller
1205 * or ndo_poll may be running while we open the device
1207 ret = netpoll_rx_disable(dev);
1211 ret = call_netdevice_notifiers(NETDEV_PRE_UP, dev);
1212 ret = notifier_to_errno(ret);
1216 set_bit(__LINK_STATE_START, &dev->state);
1218 if (ops->ndo_validate_addr)
1219 ret = ops->ndo_validate_addr(dev);
1221 if (!ret && ops->ndo_open)
1222 ret = ops->ndo_open(dev);
1224 netpoll_rx_enable(dev);
1227 clear_bit(__LINK_STATE_START, &dev->state);
1229 dev->flags |= IFF_UP;
1230 net_dmaengine_get();
1231 dev_set_rx_mode(dev);
1233 add_device_randomness(dev->dev_addr, dev->addr_len);
1240 * dev_open - prepare an interface for use.
1241 * @dev: device to open
1243 * Takes a device from down to up state. The device's private open
1244 * function is invoked and then the multicast lists are loaded. Finally
1245 * the device is moved into the up state and a %NETDEV_UP message is
1246 * sent to the netdev notifier chain.
1248 * Calling this function on an active interface is a nop. On a failure
1249 * a negative errno code is returned.
1251 int dev_open(struct net_device *dev)
1255 if (dev->flags & IFF_UP)
1258 ret = __dev_open(dev);
1262 rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
1263 call_netdevice_notifiers(NETDEV_UP, dev);
1267 EXPORT_SYMBOL(dev_open);
1269 static int __dev_close_many(struct list_head *head)
1271 struct net_device *dev;
1276 list_for_each_entry(dev, head, unreg_list) {
1277 call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
1279 clear_bit(__LINK_STATE_START, &dev->state);
1281 /* Synchronize to scheduled poll. We cannot touch poll list, it
1282 * can be even on different cpu. So just clear netif_running().
1284 * dev->stop() will invoke napi_disable() on all of it's
1285 * napi_struct instances on this device.
1287 smp_mb__after_clear_bit(); /* Commit netif_running(). */
1290 dev_deactivate_many(head);
1292 list_for_each_entry(dev, head, unreg_list) {
1293 const struct net_device_ops *ops = dev->netdev_ops;
1296 * Call the device specific close. This cannot fail.
1297 * Only if device is UP
1299 * We allow it to be called even after a DETACH hot-plug
1305 dev->flags &= ~IFF_UP;
1306 net_dmaengine_put();
1312 static int __dev_close(struct net_device *dev)
1317 /* Temporarily disable netpoll until the interface is down */
1318 retval = netpoll_rx_disable(dev);
1322 list_add(&dev->unreg_list, &single);
1323 retval = __dev_close_many(&single);
1326 netpoll_rx_enable(dev);
1330 static int dev_close_many(struct list_head *head)
1332 struct net_device *dev, *tmp;
1333 LIST_HEAD(tmp_list);
1335 list_for_each_entry_safe(dev, tmp, head, unreg_list)
1336 if (!(dev->flags & IFF_UP))
1337 list_move(&dev->unreg_list, &tmp_list);
1339 __dev_close_many(head);
1341 list_for_each_entry(dev, head, unreg_list) {
1342 rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING);
1343 call_netdevice_notifiers(NETDEV_DOWN, dev);
1346 /* rollback_registered_many needs the complete original list */
1347 list_splice(&tmp_list, head);
1352 * dev_close - shutdown an interface.
1353 * @dev: device to shutdown
1355 * This function moves an active device into down state. A
1356 * %NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
1357 * is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
1360 int dev_close(struct net_device *dev)
1363 if (dev->flags & IFF_UP) {
1366 /* Block netpoll rx while the interface is going down */
1367 ret = netpoll_rx_disable(dev);
1371 list_add(&dev->unreg_list, &single);
1372 dev_close_many(&single);
1375 netpoll_rx_enable(dev);
1379 EXPORT_SYMBOL(dev_close);
1383 * dev_disable_lro - disable Large Receive Offload on a device
1386 * Disable Large Receive Offload (LRO) on a net device. Must be
1387 * called under RTNL. This is needed if received packets may be
1388 * forwarded to another interface.
1390 void dev_disable_lro(struct net_device *dev)
1393 * If we're trying to disable lro on a vlan device
1394 * use the underlying physical device instead
1396 if (is_vlan_dev(dev))
1397 dev = vlan_dev_real_dev(dev);
1399 dev->wanted_features &= ~NETIF_F_LRO;
1400 netdev_update_features(dev);
1402 if (unlikely(dev->features & NETIF_F_LRO))
1403 netdev_WARN(dev, "failed to disable LRO!\n");
1405 EXPORT_SYMBOL(dev_disable_lro);
1408 static int dev_boot_phase = 1;
1411 * register_netdevice_notifier - register a network notifier block
1414 * Register a notifier to be called when network device events occur.
1415 * The notifier passed is linked into the kernel structures and must
1416 * not be reused until it has been unregistered. A negative errno code
1417 * is returned on a failure.
1419 * When registered all registration and up events are replayed
1420 * to the new notifier to allow device to have a race free
1421 * view of the network device list.
1424 int register_netdevice_notifier(struct notifier_block *nb)
1426 struct net_device *dev;
1427 struct net_device *last;
1432 err = raw_notifier_chain_register(&netdev_chain, nb);
1438 for_each_netdev(net, dev) {
1439 err = nb->notifier_call(nb, NETDEV_REGISTER, dev);
1440 err = notifier_to_errno(err);
1444 if (!(dev->flags & IFF_UP))
1447 nb->notifier_call(nb, NETDEV_UP, dev);
1458 for_each_netdev(net, dev) {
1462 if (dev->flags & IFF_UP) {
1463 nb->notifier_call(nb, NETDEV_GOING_DOWN, dev);
1464 nb->notifier_call(nb, NETDEV_DOWN, dev);
1466 nb->notifier_call(nb, NETDEV_UNREGISTER, dev);
1471 raw_notifier_chain_unregister(&netdev_chain, nb);
1474 EXPORT_SYMBOL(register_netdevice_notifier);
1477 * unregister_netdevice_notifier - unregister a network notifier block
1480 * Unregister a notifier previously registered by
1481 * register_netdevice_notifier(). The notifier is unlinked into the
1482 * kernel structures and may then be reused. A negative errno code
1483 * is returned on a failure.
1485 * After unregistering unregister and down device events are synthesized
1486 * for all devices on the device list to the removed notifier to remove
1487 * the need for special case cleanup code.
1490 int unregister_netdevice_notifier(struct notifier_block *nb)
1492 struct net_device *dev;
1497 err = raw_notifier_chain_unregister(&netdev_chain, nb);
1502 for_each_netdev(net, dev) {
1503 if (dev->flags & IFF_UP) {
1504 nb->notifier_call(nb, NETDEV_GOING_DOWN, dev);
1505 nb->notifier_call(nb, NETDEV_DOWN, dev);
1507 nb->notifier_call(nb, NETDEV_UNREGISTER, dev);
1514 EXPORT_SYMBOL(unregister_netdevice_notifier);
1517 * call_netdevice_notifiers - call all network notifier blocks
1518 * @val: value passed unmodified to notifier function
1519 * @dev: net_device pointer passed unmodified to notifier function
1521 * Call all network notifier blocks. Parameters and return value
1522 * are as for raw_notifier_call_chain().
1525 int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
1528 return raw_notifier_call_chain(&netdev_chain, val, dev);
1530 EXPORT_SYMBOL(call_netdevice_notifiers);
1532 static struct static_key netstamp_needed __read_mostly;
1533 #ifdef HAVE_JUMP_LABEL
1534 /* We are not allowed to call static_key_slow_dec() from irq context
1535 * If net_disable_timestamp() is called from irq context, defer the
1536 * static_key_slow_dec() calls.
1538 static atomic_t netstamp_needed_deferred;
1541 void net_enable_timestamp(void)
1543 #ifdef HAVE_JUMP_LABEL
1544 int deferred = atomic_xchg(&netstamp_needed_deferred, 0);
1548 static_key_slow_dec(&netstamp_needed);
1552 WARN_ON(in_interrupt());
1553 static_key_slow_inc(&netstamp_needed);
1555 EXPORT_SYMBOL(net_enable_timestamp);
1557 void net_disable_timestamp(void)
1559 #ifdef HAVE_JUMP_LABEL
1560 if (in_interrupt()) {
1561 atomic_inc(&netstamp_needed_deferred);
1565 static_key_slow_dec(&netstamp_needed);
1567 EXPORT_SYMBOL(net_disable_timestamp);
1569 static inline void net_timestamp_set(struct sk_buff *skb)
1571 skb->tstamp.tv64 = 0;
1572 if (static_key_false(&netstamp_needed))
1573 __net_timestamp(skb);
1576 #define net_timestamp_check(COND, SKB) \
1577 if (static_key_false(&netstamp_needed)) { \
1578 if ((COND) && !(SKB)->tstamp.tv64) \
1579 __net_timestamp(SKB); \
1582 static inline bool is_skb_forwardable(struct net_device *dev,
1583 struct sk_buff *skb)
1587 if (!(dev->flags & IFF_UP))
1590 len = dev->mtu + dev->hard_header_len + VLAN_HLEN;
1591 if (skb->len <= len)
1594 /* if TSO is enabled, we don't care about the length as the packet
1595 * could be forwarded without being segmented before
1597 if (skb_is_gso(skb))
1604 * dev_forward_skb - loopback an skb to another netif
1606 * @dev: destination network device
1607 * @skb: buffer to forward
1610 * NET_RX_SUCCESS (no congestion)
1611 * NET_RX_DROP (packet was dropped, but freed)
1613 * dev_forward_skb can be used for injecting an skb from the
1614 * start_xmit function of one device into the receive queue
1615 * of another device.
1617 * The receiving device may be in another namespace, so
1618 * we have to clear all information in the skb that could
1619 * impact namespace isolation.
1621 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
1623 if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) {
1624 if (skb_copy_ubufs(skb, GFP_ATOMIC)) {
1625 atomic_long_inc(&dev->rx_dropped);
1634 if (unlikely(!is_skb_forwardable(dev, skb))) {
1635 atomic_long_inc(&dev->rx_dropped);
1642 skb->tstamp.tv64 = 0;
1643 skb->pkt_type = PACKET_HOST;
1644 skb->protocol = eth_type_trans(skb, dev);
1648 return netif_rx(skb);
1650 EXPORT_SYMBOL_GPL(dev_forward_skb);
1652 static inline int deliver_skb(struct sk_buff *skb,
1653 struct packet_type *pt_prev,
1654 struct net_device *orig_dev)
1656 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
1658 atomic_inc(&skb->users);
1659 return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
1662 static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
1664 if (!ptype->af_packet_priv || !skb->sk)
1667 if (ptype->id_match)
1668 return ptype->id_match(ptype, skb->sk);
1669 else if ((struct sock *)ptype->af_packet_priv == skb->sk)
1676 * Support routine. Sends outgoing frames to any network
1677 * taps currently in use.
1680 static void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
1682 struct packet_type *ptype;
1683 struct sk_buff *skb2 = NULL;
1684 struct packet_type *pt_prev = NULL;
1687 list_for_each_entry_rcu(ptype, &ptype_all, list) {
1688 /* Never send packets back to the socket
1689 * they originated from - MvS (miquels@drinkel.ow.org)
1691 if ((ptype->dev == dev || !ptype->dev) &&
1692 (!skb_loop_sk(ptype, skb))) {
1694 deliver_skb(skb2, pt_prev, skb->dev);
1699 skb2 = skb_clone(skb, GFP_ATOMIC);
1703 net_timestamp_set(skb2);
1705 /* skb->nh should be correctly
1706 set by sender, so that the second statement is
1707 just protection against buggy protocols.
1709 skb_reset_mac_header(skb2);
1711 if (skb_network_header(skb2) < skb2->data ||
1712 skb2->network_header > skb2->tail) {
1713 net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
1714 ntohs(skb2->protocol),
1716 skb_reset_network_header(skb2);
1719 skb2->transport_header = skb2->network_header;
1720 skb2->pkt_type = PACKET_OUTGOING;
1725 pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
1730 * netif_setup_tc - Handle tc mappings on real_num_tx_queues change
1731 * @dev: Network device
1732 * @txq: number of queues available
1734 * If real_num_tx_queues is changed the tc mappings may no longer be
1735 * valid. To resolve this verify the tc mapping remains valid and if
1736 * not NULL the mapping. With no priorities mapping to this
1737 * offset/count pair it will no longer be used. In the worst case TC0
1738 * is invalid nothing can be done so disable priority mappings. If is
1739 * expected that drivers will fix this mapping if they can before
1740 * calling netif_set_real_num_tx_queues.
1742 static void netif_setup_tc(struct net_device *dev, unsigned int txq)
1745 struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
1747 /* If TC0 is invalidated disable TC mapping */
1748 if (tc->offset + tc->count > txq) {
1749 pr_warn("Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
1754 /* Invalidated prio to tc mappings set to TC0 */
1755 for (i = 1; i < TC_BITMASK + 1; i++) {
1756 int q = netdev_get_prio_tc_map(dev, i);
1758 tc = &dev->tc_to_txq[q];
1759 if (tc->offset + tc->count > txq) {
1760 pr_warn("Number of in use tx queues changed. Priority %i to tc mapping %i is no longer valid. Setting map to 0\n",
1762 netdev_set_prio_tc_map(dev, i, 0);
1768 static DEFINE_MUTEX(xps_map_mutex);
1769 #define xmap_dereference(P) \
1770 rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
1772 static struct xps_map *remove_xps_queue(struct xps_dev_maps *dev_maps,
1775 struct xps_map *map = NULL;
1779 map = xmap_dereference(dev_maps->cpu_map[cpu]);
1781 for (pos = 0; map && pos < map->len; pos++) {
1782 if (map->queues[pos] == index) {
1784 map->queues[pos] = map->queues[--map->len];
1786 RCU_INIT_POINTER(dev_maps->cpu_map[cpu], NULL);
1787 kfree_rcu(map, rcu);
1797 static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
1799 struct xps_dev_maps *dev_maps;
1801 bool active = false;
1803 mutex_lock(&xps_map_mutex);
1804 dev_maps = xmap_dereference(dev->xps_maps);
1809 for_each_possible_cpu(cpu) {
1810 for (i = index; i < dev->num_tx_queues; i++) {
1811 if (!remove_xps_queue(dev_maps, cpu, i))
1814 if (i == dev->num_tx_queues)
1819 RCU_INIT_POINTER(dev->xps_maps, NULL);
1820 kfree_rcu(dev_maps, rcu);
1823 for (i = index; i < dev->num_tx_queues; i++)
1824 netdev_queue_numa_node_write(netdev_get_tx_queue(dev, i),
1828 mutex_unlock(&xps_map_mutex);
1831 static struct xps_map *expand_xps_map(struct xps_map *map,
1834 struct xps_map *new_map;
1835 int alloc_len = XPS_MIN_MAP_ALLOC;
1838 for (pos = 0; map && pos < map->len; pos++) {
1839 if (map->queues[pos] != index)
1844 /* Need to add queue to this CPU's existing map */
1846 if (pos < map->alloc_len)
1849 alloc_len = map->alloc_len * 2;
1852 /* Need to allocate new map to store queue on this CPU's map */
1853 new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len), GFP_KERNEL,
1858 for (i = 0; i < pos; i++)
1859 new_map->queues[i] = map->queues[i];
1860 new_map->alloc_len = alloc_len;
1866 int netif_set_xps_queue(struct net_device *dev, struct cpumask *mask, u16 index)
1868 struct xps_dev_maps *dev_maps, *new_dev_maps = NULL;
1869 struct xps_map *map, *new_map;
1870 int maps_sz = max_t(unsigned int, XPS_DEV_MAPS_SIZE, L1_CACHE_BYTES);
1871 int cpu, numa_node_id = -2;
1872 bool active = false;
1874 mutex_lock(&xps_map_mutex);
1876 dev_maps = xmap_dereference(dev->xps_maps);
1878 /* allocate memory for queue storage */
1879 for_each_online_cpu(cpu) {
1880 if (!cpumask_test_cpu(cpu, mask))
1884 new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
1888 map = dev_maps ? xmap_dereference(dev_maps->cpu_map[cpu]) :
1891 map = expand_xps_map(map, cpu, index);
1895 RCU_INIT_POINTER(new_dev_maps->cpu_map[cpu], map);
1899 goto out_no_new_maps;
1901 for_each_possible_cpu(cpu) {
1902 if (cpumask_test_cpu(cpu, mask) && cpu_online(cpu)) {
1903 /* add queue to CPU maps */
1906 map = xmap_dereference(new_dev_maps->cpu_map[cpu]);
1907 while ((pos < map->len) && (map->queues[pos] != index))
1910 if (pos == map->len)
1911 map->queues[map->len++] = index;
1913 if (numa_node_id == -2)
1914 numa_node_id = cpu_to_node(cpu);
1915 else if (numa_node_id != cpu_to_node(cpu))
1918 } else if (dev_maps) {
1919 /* fill in the new device map from the old device map */
1920 map = xmap_dereference(dev_maps->cpu_map[cpu]);
1921 RCU_INIT_POINTER(new_dev_maps->cpu_map[cpu], map);
1926 rcu_assign_pointer(dev->xps_maps, new_dev_maps);
1928 /* Cleanup old maps */
1930 for_each_possible_cpu(cpu) {
1931 new_map = xmap_dereference(new_dev_maps->cpu_map[cpu]);
1932 map = xmap_dereference(dev_maps->cpu_map[cpu]);
1933 if (map && map != new_map)
1934 kfree_rcu(map, rcu);
1937 kfree_rcu(dev_maps, rcu);
1940 dev_maps = new_dev_maps;
1944 /* update Tx queue numa node */
1945 netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
1946 (numa_node_id >= 0) ? numa_node_id :
1952 /* removes queue from unused CPUs */
1953 for_each_possible_cpu(cpu) {
1954 if (cpumask_test_cpu(cpu, mask) && cpu_online(cpu))
1957 if (remove_xps_queue(dev_maps, cpu, index))
1961 /* free map if not active */
1963 RCU_INIT_POINTER(dev->xps_maps, NULL);
1964 kfree_rcu(dev_maps, rcu);
1968 mutex_unlock(&xps_map_mutex);
1972 /* remove any maps that we added */
1973 for_each_possible_cpu(cpu) {
1974 new_map = xmap_dereference(new_dev_maps->cpu_map[cpu]);
1975 map = dev_maps ? xmap_dereference(dev_maps->cpu_map[cpu]) :
1977 if (new_map && new_map != map)
1981 mutex_unlock(&xps_map_mutex);
1983 kfree(new_dev_maps);
1986 EXPORT_SYMBOL(netif_set_xps_queue);
1990 * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
1991 * greater then real_num_tx_queues stale skbs on the qdisc must be flushed.
1993 int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
1997 if (txq < 1 || txq > dev->num_tx_queues)
2000 if (dev->reg_state == NETREG_REGISTERED ||
2001 dev->reg_state == NETREG_UNREGISTERING) {
2004 rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
2010 netif_setup_tc(dev, txq);
2012 if (txq < dev->real_num_tx_queues) {
2013 qdisc_reset_all_tx_gt(dev, txq);
2015 netif_reset_xps_queues_gt(dev, txq);
2020 dev->real_num_tx_queues = txq;
2023 EXPORT_SYMBOL(netif_set_real_num_tx_queues);
2027 * netif_set_real_num_rx_queues - set actual number of RX queues used
2028 * @dev: Network device
2029 * @rxq: Actual number of RX queues
2031 * This must be called either with the rtnl_lock held or before
2032 * registration of the net device. Returns 0 on success, or a
2033 * negative error code. If called before registration, it always
2036 int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
2040 if (rxq < 1 || rxq > dev->num_rx_queues)
2043 if (dev->reg_state == NETREG_REGISTERED) {
2046 rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
2052 dev->real_num_rx_queues = rxq;
2055 EXPORT_SYMBOL(netif_set_real_num_rx_queues);
2059 * netif_get_num_default_rss_queues - default number of RSS queues
2061 * This routine should set an upper limit on the number of RSS queues
2062 * used by default by multiqueue devices.
2064 int netif_get_num_default_rss_queues(void)
2066 return min_t(int, DEFAULT_MAX_NUM_RSS_QUEUES, num_online_cpus());
2068 EXPORT_SYMBOL(netif_get_num_default_rss_queues);
2070 static inline void __netif_reschedule(struct Qdisc *q)
2072 struct softnet_data *sd;
2073 unsigned long flags;
2075 local_irq_save(flags);
2076 sd = &__get_cpu_var(softnet_data);
2077 q->next_sched = NULL;
2078 *sd->output_queue_tailp = q;
2079 sd->output_queue_tailp = &q->next_sched;
2080 raise_softirq_irqoff(NET_TX_SOFTIRQ);
2081 local_irq_restore(flags);
2084 void __netif_schedule(struct Qdisc *q)
2086 if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
2087 __netif_reschedule(q);
2089 EXPORT_SYMBOL(__netif_schedule);
2091 void dev_kfree_skb_irq(struct sk_buff *skb)
2093 if (atomic_dec_and_test(&skb->users)) {
2094 struct softnet_data *sd;
2095 unsigned long flags;
2097 local_irq_save(flags);
2098 sd = &__get_cpu_var(softnet_data);
2099 skb->next = sd->completion_queue;
2100 sd->completion_queue = skb;
2101 raise_softirq_irqoff(NET_TX_SOFTIRQ);
2102 local_irq_restore(flags);
2105 EXPORT_SYMBOL(dev_kfree_skb_irq);
2107 void dev_kfree_skb_any(struct sk_buff *skb)
2109 if (in_irq() || irqs_disabled())
2110 dev_kfree_skb_irq(skb);
2114 EXPORT_SYMBOL(dev_kfree_skb_any);
2118 * netif_device_detach - mark device as removed
2119 * @dev: network device
2121 * Mark device as removed from system and therefore no longer available.
2123 void netif_device_detach(struct net_device *dev)
2125 if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
2126 netif_running(dev)) {
2127 netif_tx_stop_all_queues(dev);
2130 EXPORT_SYMBOL(netif_device_detach);
2133 * netif_device_attach - mark device as attached
2134 * @dev: network device
2136 * Mark device as attached from system and restart if needed.
2138 void netif_device_attach(struct net_device *dev)
2140 if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
2141 netif_running(dev)) {
2142 netif_tx_wake_all_queues(dev);
2143 __netdev_watchdog_up(dev);
2146 EXPORT_SYMBOL(netif_device_attach);
2148 static void skb_warn_bad_offload(const struct sk_buff *skb)
2150 static const netdev_features_t null_features = 0;
2151 struct net_device *dev = skb->dev;
2152 const char *driver = "";
2154 if (dev && dev->dev.parent)
2155 driver = dev_driver_string(dev->dev.parent);
2157 WARN(1, "%s: caps=(%pNF, %pNF) len=%d data_len=%d gso_size=%d "
2158 "gso_type=%d ip_summed=%d\n",
2159 driver, dev ? &dev->features : &null_features,
2160 skb->sk ? &skb->sk->sk_route_caps : &null_features,
2161 skb->len, skb->data_len, skb_shinfo(skb)->gso_size,
2162 skb_shinfo(skb)->gso_type, skb->ip_summed);
2166 * Invalidate hardware checksum when packet is to be mangled, and
2167 * complete checksum manually on outgoing path.
2169 int skb_checksum_help(struct sk_buff *skb)
2172 int ret = 0, offset;
2174 if (skb->ip_summed == CHECKSUM_COMPLETE)
2175 goto out_set_summed;
2177 if (unlikely(skb_shinfo(skb)->gso_size)) {
2178 skb_warn_bad_offload(skb);
2182 /* Before computing a checksum, we should make sure no frag could
2183 * be modified by an external entity : checksum could be wrong.
2185 if (skb_has_shared_frag(skb)) {
2186 ret = __skb_linearize(skb);
2191 offset = skb_checksum_start_offset(skb);
2192 BUG_ON(offset >= skb_headlen(skb));
2193 csum = skb_checksum(skb, offset, skb->len - offset, 0);
2195 offset += skb->csum_offset;
2196 BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb));
2198 if (skb_cloned(skb) &&
2199 !skb_clone_writable(skb, offset + sizeof(__sum16))) {
2200 ret = pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
2205 *(__sum16 *)(skb->data + offset) = csum_fold(csum);
2207 skb->ip_summed = CHECKSUM_NONE;
2211 EXPORT_SYMBOL(skb_checksum_help);
2214 * skb_mac_gso_segment - mac layer segmentation handler.
2215 * @skb: buffer to segment
2216 * @features: features for the output path (see dev->features)
2218 struct sk_buff *skb_mac_gso_segment(struct sk_buff *skb,
2219 netdev_features_t features)
2221 struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT);
2222 struct packet_offload *ptype;
2223 __be16 type = skb->protocol;
2225 while (type == htons(ETH_P_8021Q)) {
2226 int vlan_depth = ETH_HLEN;
2227 struct vlan_hdr *vh;
2229 if (unlikely(!pskb_may_pull(skb, vlan_depth + VLAN_HLEN)))
2230 return ERR_PTR(-EINVAL);
2232 vh = (struct vlan_hdr *)(skb->data + vlan_depth);
2233 type = vh->h_vlan_encapsulated_proto;
2234 vlan_depth += VLAN_HLEN;
2237 __skb_pull(skb, skb->mac_len);
2240 list_for_each_entry_rcu(ptype, &offload_base, list) {
2241 if (ptype->type == type && ptype->callbacks.gso_segment) {
2242 if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
2245 err = ptype->callbacks.gso_send_check(skb);
2246 segs = ERR_PTR(err);
2247 if (err || skb_gso_ok(skb, features))
2249 __skb_push(skb, (skb->data -
2250 skb_network_header(skb)));
2252 segs = ptype->callbacks.gso_segment(skb, features);
2258 __skb_push(skb, skb->data - skb_mac_header(skb));
2262 EXPORT_SYMBOL(skb_mac_gso_segment);
2265 /* openvswitch calls this on rx path, so we need a different check.
2267 static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path)
2270 return skb->ip_summed != CHECKSUM_PARTIAL;
2272 return skb->ip_summed == CHECKSUM_NONE;
2276 * __skb_gso_segment - Perform segmentation on skb.
2277 * @skb: buffer to segment
2278 * @features: features for the output path (see dev->features)
2279 * @tx_path: whether it is called in TX path
2281 * This function segments the given skb and returns a list of segments.
2283 * It may return NULL if the skb requires no segmentation. This is
2284 * only possible when GSO is used for verifying header integrity.
2286 struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
2287 netdev_features_t features, bool tx_path)
2289 if (unlikely(skb_needs_check(skb, tx_path))) {
2292 skb_warn_bad_offload(skb);
2294 if (skb_header_cloned(skb) &&
2295 (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
2296 return ERR_PTR(err);
2299 SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb);
2300 skb_reset_mac_header(skb);
2301 skb_reset_mac_len(skb);
2303 return skb_mac_gso_segment(skb, features);
2305 EXPORT_SYMBOL(__skb_gso_segment);
2307 /* Take action when hardware reception checksum errors are detected. */
2309 void netdev_rx_csum_fault(struct net_device *dev)
2311 if (net_ratelimit()) {
2312 pr_err("%s: hw csum failure\n", dev ? dev->name : "<unknown>");
2316 EXPORT_SYMBOL(netdev_rx_csum_fault);
2319 /* Actually, we should eliminate this check as soon as we know, that:
2320 * 1. IOMMU is present and allows to map all the memory.
2321 * 2. No high memory really exists on this machine.
2324 static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
2326 #ifdef CONFIG_HIGHMEM
2328 if (!(dev->features & NETIF_F_HIGHDMA)) {
2329 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
2330 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
2331 if (PageHighMem(skb_frag_page(frag)))
2336 if (PCI_DMA_BUS_IS_PHYS) {
2337 struct device *pdev = dev->dev.parent;
2341 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
2342 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
2343 dma_addr_t addr = page_to_phys(skb_frag_page(frag));
2344 if (!pdev->dma_mask || addr + PAGE_SIZE - 1 > *pdev->dma_mask)
2353 void (*destructor)(struct sk_buff *skb);
2356 #define DEV_GSO_CB(skb) ((struct dev_gso_cb *)(skb)->cb)
2358 static void dev_gso_skb_destructor(struct sk_buff *skb)
2360 struct dev_gso_cb *cb;
2363 struct sk_buff *nskb = skb->next;
2365 skb->next = nskb->next;
2368 } while (skb->next);
2370 cb = DEV_GSO_CB(skb);
2372 cb->destructor(skb);
2376 * dev_gso_segment - Perform emulated hardware segmentation on skb.
2377 * @skb: buffer to segment
2378 * @features: device features as applicable to this skb
2380 * This function segments the given skb and stores the list of segments
2383 static int dev_gso_segment(struct sk_buff *skb, netdev_features_t features)
2385 struct sk_buff *segs;
2387 segs = skb_gso_segment(skb, features);
2389 /* Verifying header integrity only. */
2394 return PTR_ERR(segs);
2397 DEV_GSO_CB(skb)->destructor = skb->destructor;
2398 skb->destructor = dev_gso_skb_destructor;
2403 static bool can_checksum_protocol(netdev_features_t features, __be16 protocol)
2405 return ((features & NETIF_F_GEN_CSUM) ||
2406 ((features & NETIF_F_V4_CSUM) &&
2407 protocol == htons(ETH_P_IP)) ||
2408 ((features & NETIF_F_V6_CSUM) &&
2409 protocol == htons(ETH_P_IPV6)) ||
2410 ((features & NETIF_F_FCOE_CRC) &&
2411 protocol == htons(ETH_P_FCOE)));
2414 static netdev_features_t harmonize_features(struct sk_buff *skb,
2415 __be16 protocol, netdev_features_t features)
2417 if (skb->ip_summed != CHECKSUM_NONE &&
2418 !can_checksum_protocol(features, protocol)) {
2419 features &= ~NETIF_F_ALL_CSUM;
2420 features &= ~NETIF_F_SG;
2421 } else if (illegal_highdma(skb->dev, skb)) {
2422 features &= ~NETIF_F_SG;
2428 netdev_features_t netif_skb_features(struct sk_buff *skb)
2430 __be16 protocol = skb->protocol;
2431 netdev_features_t features = skb->dev->features;
2433 if (skb_shinfo(skb)->gso_segs > skb->dev->gso_max_segs)
2434 features &= ~NETIF_F_GSO_MASK;
2436 if (protocol == htons(ETH_P_8021Q)) {
2437 struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data;
2438 protocol = veh->h_vlan_encapsulated_proto;
2439 } else if (!vlan_tx_tag_present(skb)) {
2440 return harmonize_features(skb, protocol, features);
2443 features &= (skb->dev->vlan_features | NETIF_F_HW_VLAN_TX);
2445 if (protocol != htons(ETH_P_8021Q)) {
2446 return harmonize_features(skb, protocol, features);
2448 features &= NETIF_F_SG | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST |
2449 NETIF_F_GEN_CSUM | NETIF_F_HW_VLAN_TX;
2450 return harmonize_features(skb, protocol, features);
2453 EXPORT_SYMBOL(netif_skb_features);
2456 * Returns true if either:
2457 * 1. skb has frag_list and the device doesn't support FRAGLIST, or
2458 * 2. skb is fragmented and the device does not support SG.
2460 static inline int skb_needs_linearize(struct sk_buff *skb,
2463 return skb_is_nonlinear(skb) &&
2464 ((skb_has_frag_list(skb) &&
2465 !(features & NETIF_F_FRAGLIST)) ||
2466 (skb_shinfo(skb)->nr_frags &&
2467 !(features & NETIF_F_SG)));
2470 int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
2471 struct netdev_queue *txq)
2473 const struct net_device_ops *ops = dev->netdev_ops;
2474 int rc = NETDEV_TX_OK;
2475 unsigned int skb_len;
2477 if (likely(!skb->next)) {
2478 netdev_features_t features;
2481 * If device doesn't need skb->dst, release it right now while
2482 * its hot in this cpu cache
2484 if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
2487 features = netif_skb_features(skb);
2489 if (vlan_tx_tag_present(skb) &&
2490 !(features & NETIF_F_HW_VLAN_TX)) {
2491 skb = __vlan_put_tag(skb, vlan_tx_tag_get(skb));
2498 /* If encapsulation offload request, verify we are testing
2499 * hardware encapsulation features instead of standard
2500 * features for the netdev
2502 if (skb->encapsulation)
2503 features &= dev->hw_enc_features;
2505 if (netif_needs_gso(skb, features)) {
2506 if (unlikely(dev_gso_segment(skb, features)))
2511 if (skb_needs_linearize(skb, features) &&
2512 __skb_linearize(skb))
2515 /* If packet is not checksummed and device does not
2516 * support checksumming for this protocol, complete
2517 * checksumming here.
2519 if (skb->ip_summed == CHECKSUM_PARTIAL) {
2520 if (skb->encapsulation)
2521 skb_set_inner_transport_header(skb,
2522 skb_checksum_start_offset(skb));
2524 skb_set_transport_header(skb,
2525 skb_checksum_start_offset(skb));
2526 if (!(features & NETIF_F_ALL_CSUM) &&
2527 skb_checksum_help(skb))
2532 if (!list_empty(&ptype_all))
2533 dev_queue_xmit_nit(skb, dev);
2536 rc = ops->ndo_start_xmit(skb, dev);
2537 trace_net_dev_xmit(skb, rc, dev, skb_len);
2538 if (rc == NETDEV_TX_OK)
2539 txq_trans_update(txq);
2545 struct sk_buff *nskb = skb->next;
2547 skb->next = nskb->next;
2551 * If device doesn't need nskb->dst, release it right now while
2552 * its hot in this cpu cache
2554 if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
2557 if (!list_empty(&ptype_all))
2558 dev_queue_xmit_nit(nskb, dev);
2560 skb_len = nskb->len;
2561 rc = ops->ndo_start_xmit(nskb, dev);
2562 trace_net_dev_xmit(nskb, rc, dev, skb_len);
2563 if (unlikely(rc != NETDEV_TX_OK)) {
2564 if (rc & ~NETDEV_TX_MASK)
2565 goto out_kfree_gso_skb;
2566 nskb->next = skb->next;
2570 txq_trans_update(txq);
2571 if (unlikely(netif_xmit_stopped(txq) && skb->next))
2572 return NETDEV_TX_BUSY;
2573 } while (skb->next);
2576 if (likely(skb->next == NULL))
2577 skb->destructor = DEV_GSO_CB(skb)->destructor;
2584 static void qdisc_pkt_len_init(struct sk_buff *skb)
2586 const struct skb_shared_info *shinfo = skb_shinfo(skb);
2588 qdisc_skb_cb(skb)->pkt_len = skb->len;
2590 /* To get more precise estimation of bytes sent on wire,
2591 * we add to pkt_len the headers size of all segments
2593 if (shinfo->gso_size) {
2594 unsigned int hdr_len;
2596 /* mac layer + network layer */
2597 hdr_len = skb_transport_header(skb) - skb_mac_header(skb);
2599 /* + transport layer */
2600 if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)))
2601 hdr_len += tcp_hdrlen(skb);
2603 hdr_len += sizeof(struct udphdr);
2604 qdisc_skb_cb(skb)->pkt_len += (shinfo->gso_segs - 1) * hdr_len;
2608 static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
2609 struct net_device *dev,
2610 struct netdev_queue *txq)
2612 spinlock_t *root_lock = qdisc_lock(q);
2616 qdisc_pkt_len_init(skb);
2617 qdisc_calculate_pkt_len(skb, q);
2619 * Heuristic to force contended enqueues to serialize on a
2620 * separate lock before trying to get qdisc main lock.
2621 * This permits __QDISC_STATE_RUNNING owner to get the lock more often
2622 * and dequeue packets faster.
2624 contended = qdisc_is_running(q);
2625 if (unlikely(contended))
2626 spin_lock(&q->busylock);
2628 spin_lock(root_lock);
2629 if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
2632 } else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
2633 qdisc_run_begin(q)) {
2635 * This is a work-conserving queue; there are no old skbs
2636 * waiting to be sent out; and the qdisc is not running -
2637 * xmit the skb directly.
2639 if (!(dev->priv_flags & IFF_XMIT_DST_RELEASE))
2642 qdisc_bstats_update(q, skb);
2644 if (sch_direct_xmit(skb, q, dev, txq, root_lock)) {
2645 if (unlikely(contended)) {
2646 spin_unlock(&q->busylock);
2653 rc = NET_XMIT_SUCCESS;
2656 rc = q->enqueue(skb, q) & NET_XMIT_MASK;
2657 if (qdisc_run_begin(q)) {
2658 if (unlikely(contended)) {
2659 spin_unlock(&q->busylock);
2665 spin_unlock(root_lock);
2666 if (unlikely(contended))
2667 spin_unlock(&q->busylock);
2671 #if IS_ENABLED(CONFIG_NETPRIO_CGROUP)
2672 static void skb_update_prio(struct sk_buff *skb)
2674 struct netprio_map *map = rcu_dereference_bh(skb->dev->priomap);
2676 if (!skb->priority && skb->sk && map) {
2677 unsigned int prioidx = skb->sk->sk_cgrp_prioidx;
2679 if (prioidx < map->priomap_len)
2680 skb->priority = map->priomap[prioidx];
2684 #define skb_update_prio(skb)
2687 static DEFINE_PER_CPU(int, xmit_recursion);
2688 #define RECURSION_LIMIT 10
2691 * dev_loopback_xmit - loop back @skb
2692 * @skb: buffer to transmit
2694 int dev_loopback_xmit(struct sk_buff *skb)
2696 skb_reset_mac_header(skb);
2697 __skb_pull(skb, skb_network_offset(skb));
2698 skb->pkt_type = PACKET_LOOPBACK;
2699 skb->ip_summed = CHECKSUM_UNNECESSARY;
2700 WARN_ON(!skb_dst(skb));
2705 EXPORT_SYMBOL(dev_loopback_xmit);
2708 * dev_queue_xmit - transmit a buffer
2709 * @skb: buffer to transmit
2711 * Queue a buffer for transmission to a network device. The caller must
2712 * have set the device and priority and built the buffer before calling
2713 * this function. The function can be called from an interrupt.
2715 * A negative errno code is returned on a failure. A success does not
2716 * guarantee the frame will be transmitted as it may be dropped due
2717 * to congestion or traffic shaping.
2719 * -----------------------------------------------------------------------------------
2720 * I notice this method can also return errors from the queue disciplines,
2721 * including NET_XMIT_DROP, which is a positive value. So, errors can also
2724 * Regardless of the return value, the skb is consumed, so it is currently
2725 * difficult to retry a send to this method. (You can bump the ref count
2726 * before sending to hold a reference for retry if you are careful.)
2728 * When calling this method, interrupts MUST be enabled. This is because
2729 * the BH enable code must have IRQs enabled so that it will not deadlock.
2732 int dev_queue_xmit(struct sk_buff *skb)
2734 struct net_device *dev = skb->dev;
2735 struct netdev_queue *txq;
2739 skb_reset_mac_header(skb);
2741 /* Disable soft irqs for various locks below. Also
2742 * stops preemption for RCU.
2746 skb_update_prio(skb);
2748 txq = netdev_pick_tx(dev, skb);
2749 q = rcu_dereference_bh(txq->qdisc);
2751 #ifdef CONFIG_NET_CLS_ACT
2752 skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_EGRESS);
2754 trace_net_dev_queue(skb);
2756 rc = __dev_xmit_skb(skb, q, dev, txq);
2760 /* The device has no queue. Common case for software devices:
2761 loopback, all the sorts of tunnels...
2763 Really, it is unlikely that netif_tx_lock protection is necessary
2764 here. (f.e. loopback and IP tunnels are clean ignoring statistics
2766 However, it is possible, that they rely on protection
2769 Check this and shot the lock. It is not prone from deadlocks.
2770 Either shot noqueue qdisc, it is even simpler 8)
2772 if (dev->flags & IFF_UP) {
2773 int cpu = smp_processor_id(); /* ok because BHs are off */
2775 if (txq->xmit_lock_owner != cpu) {
2777 if (__this_cpu_read(xmit_recursion) > RECURSION_LIMIT)
2778 goto recursion_alert;
2780 HARD_TX_LOCK(dev, txq, cpu);
2782 if (!netif_xmit_stopped(txq)) {
2783 __this_cpu_inc(xmit_recursion);
2784 rc = dev_hard_start_xmit(skb, dev, txq);
2785 __this_cpu_dec(xmit_recursion);
2786 if (dev_xmit_complete(rc)) {
2787 HARD_TX_UNLOCK(dev, txq);
2791 HARD_TX_UNLOCK(dev, txq);
2792 net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
2795 /* Recursion is detected! It is possible,
2799 net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
2805 rcu_read_unlock_bh();
2810 rcu_read_unlock_bh();
2813 EXPORT_SYMBOL(dev_queue_xmit);
2816 /*=======================================================================
2818 =======================================================================*/
2820 int netdev_max_backlog __read_mostly = 1000;
2821 EXPORT_SYMBOL(netdev_max_backlog);
2823 int netdev_tstamp_prequeue __read_mostly = 1;
2824 int netdev_budget __read_mostly = 300;
2825 int weight_p __read_mostly = 64; /* old backlog weight */
2827 /* Called with irq disabled */
2828 static inline void ____napi_schedule(struct softnet_data *sd,
2829 struct napi_struct *napi)
2831 list_add_tail(&napi->poll_list, &sd->poll_list);
2832 __raise_softirq_irqoff(NET_RX_SOFTIRQ);
2837 /* One global table that all flow-based protocols share. */
2838 struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
2839 EXPORT_SYMBOL(rps_sock_flow_table);
2841 struct static_key rps_needed __read_mostly;
2843 static struct rps_dev_flow *
2844 set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
2845 struct rps_dev_flow *rflow, u16 next_cpu)
2847 if (next_cpu != RPS_NO_CPU) {
2848 #ifdef CONFIG_RFS_ACCEL
2849 struct netdev_rx_queue *rxqueue;
2850 struct rps_dev_flow_table *flow_table;
2851 struct rps_dev_flow *old_rflow;
2856 /* Should we steer this flow to a different hardware queue? */
2857 if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
2858 !(dev->features & NETIF_F_NTUPLE))
2860 rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
2861 if (rxq_index == skb_get_rx_queue(skb))
2864 rxqueue = dev->_rx + rxq_index;
2865 flow_table = rcu_dereference(rxqueue->rps_flow_table);
2868 flow_id = skb->rxhash & flow_table->mask;
2869 rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
2870 rxq_index, flow_id);
2874 rflow = &flow_table->flows[flow_id];
2876 if (old_rflow->filter == rflow->filter)
2877 old_rflow->filter = RPS_NO_FILTER;
2881 per_cpu(softnet_data, next_cpu).input_queue_head;
2884 rflow->cpu = next_cpu;
2889 * get_rps_cpu is called from netif_receive_skb and returns the target
2890 * CPU from the RPS map of the receiving queue for a given skb.
2891 * rcu_read_lock must be held on entry.
2893 static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
2894 struct rps_dev_flow **rflowp)
2896 struct netdev_rx_queue *rxqueue;
2897 struct rps_map *map;
2898 struct rps_dev_flow_table *flow_table;
2899 struct rps_sock_flow_table *sock_flow_table;
2903 if (skb_rx_queue_recorded(skb)) {
2904 u16 index = skb_get_rx_queue(skb);
2905 if (unlikely(index >= dev->real_num_rx_queues)) {
2906 WARN_ONCE(dev->real_num_rx_queues > 1,
2907 "%s received packet on queue %u, but number "
2908 "of RX queues is %u\n",
2909 dev->name, index, dev->real_num_rx_queues);
2912 rxqueue = dev->_rx + index;
2916 map = rcu_dereference(rxqueue->rps_map);
2918 if (map->len == 1 &&
2919 !rcu_access_pointer(rxqueue->rps_flow_table)) {
2920 tcpu = map->cpus[0];
2921 if (cpu_online(tcpu))
2925 } else if (!rcu_access_pointer(rxqueue->rps_flow_table)) {
2929 skb_reset_network_header(skb);
2930 if (!skb_get_rxhash(skb))
2933 flow_table = rcu_dereference(rxqueue->rps_flow_table);
2934 sock_flow_table = rcu_dereference(rps_sock_flow_table);
2935 if (flow_table && sock_flow_table) {
2937 struct rps_dev_flow *rflow;
2939 rflow = &flow_table->flows[skb->rxhash & flow_table->mask];
2942 next_cpu = sock_flow_table->ents[skb->rxhash &
2943 sock_flow_table->mask];
2946 * If the desired CPU (where last recvmsg was done) is
2947 * different from current CPU (one in the rx-queue flow
2948 * table entry), switch if one of the following holds:
2949 * - Current CPU is unset (equal to RPS_NO_CPU).
2950 * - Current CPU is offline.
2951 * - The current CPU's queue tail has advanced beyond the
2952 * last packet that was enqueued using this table entry.
2953 * This guarantees that all previous packets for the flow
2954 * have been dequeued, thus preserving in order delivery.
2956 if (unlikely(tcpu != next_cpu) &&
2957 (tcpu == RPS_NO_CPU || !cpu_online(tcpu) ||
2958 ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
2959 rflow->last_qtail)) >= 0)) {
2961 rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
2964 if (tcpu != RPS_NO_CPU && cpu_online(tcpu)) {
2972 tcpu = map->cpus[((u64) skb->rxhash * map->len) >> 32];
2974 if (cpu_online(tcpu)) {
2984 #ifdef CONFIG_RFS_ACCEL
2987 * rps_may_expire_flow - check whether an RFS hardware filter may be removed
2988 * @dev: Device on which the filter was set
2989 * @rxq_index: RX queue index
2990 * @flow_id: Flow ID passed to ndo_rx_flow_steer()
2991 * @filter_id: Filter ID returned by ndo_rx_flow_steer()
2993 * Drivers that implement ndo_rx_flow_steer() should periodically call
2994 * this function for each installed filter and remove the filters for
2995 * which it returns %true.
2997 bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
2998 u32 flow_id, u16 filter_id)
3000 struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
3001 struct rps_dev_flow_table *flow_table;
3002 struct rps_dev_flow *rflow;
3007 flow_table = rcu_dereference(rxqueue->rps_flow_table);
3008 if (flow_table && flow_id <= flow_table->mask) {
3009 rflow = &flow_table->flows[flow_id];
3010 cpu = ACCESS_ONCE(rflow->cpu);
3011 if (rflow->filter == filter_id && cpu != RPS_NO_CPU &&
3012 ((int)(per_cpu(softnet_data, cpu).input_queue_head -
3013 rflow->last_qtail) <
3014 (int)(10 * flow_table->mask)))
3020 EXPORT_SYMBOL(rps_may_expire_flow);
3022 #endif /* CONFIG_RFS_ACCEL */
3024 /* Called from hardirq (IPI) context */
3025 static void rps_trigger_softirq(void *data)
3027 struct softnet_data *sd = data;
3029 ____napi_schedule(sd, &sd->backlog);
3033 #endif /* CONFIG_RPS */
3036 * Check if this softnet_data structure is another cpu one
3037 * If yes, queue it to our IPI list and return 1
3040 static int rps_ipi_queued(struct softnet_data *sd)
3043 struct softnet_data *mysd = &__get_cpu_var(softnet_data);
3046 sd->rps_ipi_next = mysd->rps_ipi_list;
3047 mysd->rps_ipi_list = sd;
3049 __raise_softirq_irqoff(NET_RX_SOFTIRQ);
3052 #endif /* CONFIG_RPS */
3057 * enqueue_to_backlog is called to queue an skb to a per CPU backlog
3058 * queue (may be a remote CPU queue).
3060 static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
3061 unsigned int *qtail)
3063 struct softnet_data *sd;
3064 unsigned long flags;
3066 sd = &per_cpu(softnet_data, cpu);
3068 local_irq_save(flags);
3071 if (skb_queue_len(&sd->input_pkt_queue) <= netdev_max_backlog) {
3072 if (skb_queue_len(&sd->input_pkt_queue)) {
3074 __skb_queue_tail(&sd->input_pkt_queue, skb);
3075 input_queue_tail_incr_save(sd, qtail);
3077 local_irq_restore(flags);
3078 return NET_RX_SUCCESS;
3081 /* Schedule NAPI for backlog device
3082 * We can use non atomic operation since we own the queue lock
3084 if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state)) {
3085 if (!rps_ipi_queued(sd))
3086 ____napi_schedule(sd, &sd->backlog);
3094 local_irq_restore(flags);
3096 atomic_long_inc(&skb->dev->rx_dropped);
3102 * netif_rx - post buffer to the network code
3103 * @skb: buffer to post
3105 * This function receives a packet from a device driver and queues it for
3106 * the upper (protocol) levels to process. It always succeeds. The buffer
3107 * may be dropped during processing for congestion control or by the
3111 * NET_RX_SUCCESS (no congestion)
3112 * NET_RX_DROP (packet was dropped)
3116 int netif_rx(struct sk_buff *skb)
3120 /* if netpoll wants it, pretend we never saw it */
3121 if (netpoll_rx(skb))
3124 net_timestamp_check(netdev_tstamp_prequeue, skb);
3126 trace_netif_rx(skb);
3128 if (static_key_false(&rps_needed)) {
3129 struct rps_dev_flow voidflow, *rflow = &voidflow;
3135 cpu = get_rps_cpu(skb->dev, skb, &rflow);
3137 cpu = smp_processor_id();
3139 ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
3147 ret = enqueue_to_backlog(skb, get_cpu(), &qtail);
3152 EXPORT_SYMBOL(netif_rx);
3154 int netif_rx_ni(struct sk_buff *skb)
3159 err = netif_rx(skb);
3160 if (local_softirq_pending())
3166 EXPORT_SYMBOL(netif_rx_ni);
3168 static void net_tx_action(struct softirq_action *h)
3170 struct softnet_data *sd = &__get_cpu_var(softnet_data);
3172 if (sd->completion_queue) {
3173 struct sk_buff *clist;
3175 local_irq_disable();
3176 clist = sd->completion_queue;
3177 sd->completion_queue = NULL;
3181 struct sk_buff *skb = clist;
3182 clist = clist->next;
3184 WARN_ON(atomic_read(&skb->users));
3185 trace_kfree_skb(skb, net_tx_action);
3190 if (sd->output_queue) {
3193 local_irq_disable();
3194 head = sd->output_queue;
3195 sd->output_queue = NULL;
3196 sd->output_queue_tailp = &sd->output_queue;
3200 struct Qdisc *q = head;
3201 spinlock_t *root_lock;
3203 head = head->next_sched;
3205 root_lock = qdisc_lock(q);
3206 if (spin_trylock(root_lock)) {
3207 smp_mb__before_clear_bit();
3208 clear_bit(__QDISC_STATE_SCHED,
3211 spin_unlock(root_lock);
3213 if (!test_bit(__QDISC_STATE_DEACTIVATED,
3215 __netif_reschedule(q);
3217 smp_mb__before_clear_bit();
3218 clear_bit(__QDISC_STATE_SCHED,
3226 #if (defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)) && \
3227 (defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE))
3228 /* This hook is defined here for ATM LANE */
3229 int (*br_fdb_test_addr_hook)(struct net_device *dev,
3230 unsigned char *addr) __read_mostly;
3231 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
3234 #ifdef CONFIG_NET_CLS_ACT
3235 /* TODO: Maybe we should just force sch_ingress to be compiled in
3236 * when CONFIG_NET_CLS_ACT is? otherwise some useless instructions
3237 * a compare and 2 stores extra right now if we dont have it on
3238 * but have CONFIG_NET_CLS_ACT
3239 * NOTE: This doesn't stop any functionality; if you dont have
3240 * the ingress scheduler, you just can't add policies on ingress.
3243 static int ing_filter(struct sk_buff *skb, struct netdev_queue *rxq)
3245 struct net_device *dev = skb->dev;
3246 u32 ttl = G_TC_RTTL(skb->tc_verd);
3247 int result = TC_ACT_OK;
3250 if (unlikely(MAX_RED_LOOP < ttl++)) {
3251 net_warn_ratelimited("Redir loop detected Dropping packet (%d->%d)\n",
3252 skb->skb_iif, dev->ifindex);
3256 skb->tc_verd = SET_TC_RTTL(skb->tc_verd, ttl);
3257 skb->tc_verd = SET_TC_AT(skb->tc_verd, AT_INGRESS);
3260 if (q != &noop_qdisc) {
3261 spin_lock(qdisc_lock(q));
3262 if (likely(!test_bit(__QDISC_STATE_DEACTIVATED, &q->state)))
3263 result = qdisc_enqueue_root(skb, q);
3264 spin_unlock(qdisc_lock(q));
3270 static inline struct sk_buff *handle_ing(struct sk_buff *skb,
3271 struct packet_type **pt_prev,
3272 int *ret, struct net_device *orig_dev)
3274 struct netdev_queue *rxq = rcu_dereference(skb->dev->ingress_queue);
3276 if (!rxq || rxq->qdisc == &noop_qdisc)
3280 *ret = deliver_skb(skb, *pt_prev, orig_dev);
3284 switch (ing_filter(skb, rxq)) {
3298 * netdev_rx_handler_register - register receive handler
3299 * @dev: device to register a handler for
3300 * @rx_handler: receive handler to register
3301 * @rx_handler_data: data pointer that is used by rx handler
3303 * Register a receive hander for a device. This handler will then be
3304 * called from __netif_receive_skb. A negative errno code is returned
3307 * The caller must hold the rtnl_mutex.
3309 * For a general description of rx_handler, see enum rx_handler_result.
3311 int netdev_rx_handler_register(struct net_device *dev,
3312 rx_handler_func_t *rx_handler,
3313 void *rx_handler_data)
3317 if (dev->rx_handler)
3320 rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
3321 rcu_assign_pointer(dev->rx_handler, rx_handler);
3325 EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
3328 * netdev_rx_handler_unregister - unregister receive handler
3329 * @dev: device to unregister a handler from
3331 * Unregister a receive hander from a device.
3333 * The caller must hold the rtnl_mutex.
3335 void netdev_rx_handler_unregister(struct net_device *dev)
3339 RCU_INIT_POINTER(dev->rx_handler, NULL);
3340 RCU_INIT_POINTER(dev->rx_handler_data, NULL);
3342 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
3345 * Limit the use of PFMEMALLOC reserves to those protocols that implement
3346 * the special handling of PFMEMALLOC skbs.
3348 static bool skb_pfmemalloc_protocol(struct sk_buff *skb)
3350 switch (skb->protocol) {
3351 case __constant_htons(ETH_P_ARP):
3352 case __constant_htons(ETH_P_IP):
3353 case __constant_htons(ETH_P_IPV6):
3354 case __constant_htons(ETH_P_8021Q):
3361 static int __netif_receive_skb_core(struct sk_buff *skb, bool pfmemalloc)
3363 struct packet_type *ptype, *pt_prev;
3364 rx_handler_func_t *rx_handler;
3365 struct net_device *orig_dev;
3366 struct net_device *null_or_dev;
3367 bool deliver_exact = false;
3368 int ret = NET_RX_DROP;
3371 net_timestamp_check(!netdev_tstamp_prequeue, skb);
3373 trace_netif_receive_skb(skb);
3375 /* if we've gotten here through NAPI, check netpoll */
3376 if (netpoll_receive_skb(skb))
3379 orig_dev = skb->dev;
3381 skb_reset_network_header(skb);
3382 if (!skb_transport_header_was_set(skb))
3383 skb_reset_transport_header(skb);
3384 skb_reset_mac_len(skb);
3391 skb->skb_iif = skb->dev->ifindex;
3393 __this_cpu_inc(softnet_data.processed);
3395 if (skb->protocol == cpu_to_be16(ETH_P_8021Q)) {
3396 skb = vlan_untag(skb);
3401 #ifdef CONFIG_NET_CLS_ACT
3402 if (skb->tc_verd & TC_NCLS) {
3403 skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
3411 list_for_each_entry_rcu(ptype, &ptype_all, list) {
3412 if (!ptype->dev || ptype->dev == skb->dev) {
3414 ret = deliver_skb(skb, pt_prev, orig_dev);
3420 #ifdef CONFIG_NET_CLS_ACT
3421 skb = handle_ing(skb, &pt_prev, &ret, orig_dev);
3427 if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
3430 if (vlan_tx_tag_present(skb)) {
3432 ret = deliver_skb(skb, pt_prev, orig_dev);
3435 if (vlan_do_receive(&skb))
3437 else if (unlikely(!skb))
3441 rx_handler = rcu_dereference(skb->dev->rx_handler);
3444 ret = deliver_skb(skb, pt_prev, orig_dev);
3447 switch (rx_handler(&skb)) {
3448 case RX_HANDLER_CONSUMED:
3450 case RX_HANDLER_ANOTHER:
3452 case RX_HANDLER_EXACT:
3453 deliver_exact = true;
3454 case RX_HANDLER_PASS:
3461 if (vlan_tx_nonzero_tag_present(skb))
3462 skb->pkt_type = PACKET_OTHERHOST;
3464 /* deliver only exact match when indicated */
3465 null_or_dev = deliver_exact ? skb->dev : NULL;
3467 type = skb->protocol;
3468 list_for_each_entry_rcu(ptype,
3469 &ptype_base[ntohs(type) & PTYPE_HASH_MASK], list) {
3470 if (ptype->type == type &&
3471 (ptype->dev == null_or_dev || ptype->dev == skb->dev ||
3472 ptype->dev == orig_dev)) {
3474 ret = deliver_skb(skb, pt_prev, orig_dev);
3480 if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
3483 ret = pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
3486 atomic_long_inc(&skb->dev->rx_dropped);
3488 /* Jamal, now you will not able to escape explaining
3489 * me how you were going to use this. :-)
3500 static int __netif_receive_skb(struct sk_buff *skb)
3504 if (sk_memalloc_socks() && skb_pfmemalloc(skb)) {
3505 unsigned long pflags = current->flags;
3508 * PFMEMALLOC skbs are special, they should
3509 * - be delivered to SOCK_MEMALLOC sockets only
3510 * - stay away from userspace
3511 * - have bounded memory usage
3513 * Use PF_MEMALLOC as this saves us from propagating the allocation
3514 * context down to all allocation sites.
3516 current->flags |= PF_MEMALLOC;
3517 ret = __netif_receive_skb_core(skb, true);
3518 tsk_restore_flags(current, pflags, PF_MEMALLOC);
3520 ret = __netif_receive_skb_core(skb, false);
3526 * netif_receive_skb - process receive buffer from network
3527 * @skb: buffer to process
3529 * netif_receive_skb() is the main receive data processing function.
3530 * It always succeeds. The buffer may be dropped during processing
3531 * for congestion control or by the protocol layers.
3533 * This function may only be called from softirq context and interrupts
3534 * should be enabled.
3536 * Return values (usually ignored):
3537 * NET_RX_SUCCESS: no congestion
3538 * NET_RX_DROP: packet was dropped
3540 int netif_receive_skb(struct sk_buff *skb)
3542 net_timestamp_check(netdev_tstamp_prequeue, skb);
3544 if (skb_defer_rx_timestamp(skb))
3545 return NET_RX_SUCCESS;
3548 if (static_key_false(&rps_needed)) {
3549 struct rps_dev_flow voidflow, *rflow = &voidflow;
3554 cpu = get_rps_cpu(skb->dev, skb, &rflow);
3557 ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
3564 return __netif_receive_skb(skb);
3566 EXPORT_SYMBOL(netif_receive_skb);
3568 /* Network device is going away, flush any packets still pending
3569 * Called with irqs disabled.
3571 static void flush_backlog(void *arg)
3573 struct net_device *dev = arg;
3574 struct softnet_data *sd = &__get_cpu_var(softnet_data);
3575 struct sk_buff *skb, *tmp;
3578 skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
3579 if (skb->dev == dev) {
3580 __skb_unlink(skb, &sd->input_pkt_queue);
3582 input_queue_head_incr(sd);
3587 skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
3588 if (skb->dev == dev) {
3589 __skb_unlink(skb, &sd->process_queue);
3591 input_queue_head_incr(sd);
3596 static int napi_gro_complete(struct sk_buff *skb)
3598 struct packet_offload *ptype;
3599 __be16 type = skb->protocol;
3600 struct list_head *head = &offload_base;
3603 BUILD_BUG_ON(sizeof(struct napi_gro_cb) > sizeof(skb->cb));
3605 if (NAPI_GRO_CB(skb)->count == 1) {
3606 skb_shinfo(skb)->gso_size = 0;
3611 list_for_each_entry_rcu(ptype, head, list) {
3612 if (ptype->type != type || !ptype->callbacks.gro_complete)
3615 err = ptype->callbacks.gro_complete(skb);
3621 WARN_ON(&ptype->list == head);
3623 return NET_RX_SUCCESS;
3627 return netif_receive_skb(skb);
3630 /* napi->gro_list contains packets ordered by age.
3631 * youngest packets at the head of it.
3632 * Complete skbs in reverse order to reduce latencies.
3634 void napi_gro_flush(struct napi_struct *napi, bool flush_old)
3636 struct sk_buff *skb, *prev = NULL;
3638 /* scan list and build reverse chain */
3639 for (skb = napi->gro_list; skb != NULL; skb = skb->next) {
3644 for (skb = prev; skb; skb = prev) {
3647 if (flush_old && NAPI_GRO_CB(skb)->age == jiffies)
3651 napi_gro_complete(skb);
3655 napi->gro_list = NULL;
3657 EXPORT_SYMBOL(napi_gro_flush);
3659 static void gro_list_prepare(struct napi_struct *napi, struct sk_buff *skb)
3662 unsigned int maclen = skb->dev->hard_header_len;
3664 for (p = napi->gro_list; p; p = p->next) {
3665 unsigned long diffs;
3667 diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev;
3668 diffs |= p->vlan_tci ^ skb->vlan_tci;
3669 if (maclen == ETH_HLEN)
3670 diffs |= compare_ether_header(skb_mac_header(p),
3671 skb_gro_mac_header(skb));
3673 diffs = memcmp(skb_mac_header(p),
3674 skb_gro_mac_header(skb),
3676 NAPI_GRO_CB(p)->same_flow = !diffs;
3677 NAPI_GRO_CB(p)->flush = 0;
3681 static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3683 struct sk_buff **pp = NULL;
3684 struct packet_offload *ptype;
3685 __be16 type = skb->protocol;
3686 struct list_head *head = &offload_base;
3688 enum gro_result ret;
3690 if (!(skb->dev->features & NETIF_F_GRO) || netpoll_rx_on(skb))
3693 if (skb_is_gso(skb) || skb_has_frag_list(skb))
3696 gro_list_prepare(napi, skb);
3699 list_for_each_entry_rcu(ptype, head, list) {
3700 if (ptype->type != type || !ptype->callbacks.gro_receive)
3703 skb_set_network_header(skb, skb_gro_offset(skb));
3704 skb_reset_mac_len(skb);
3705 NAPI_GRO_CB(skb)->same_flow = 0;
3706 NAPI_GRO_CB(skb)->flush = 0;
3707 NAPI_GRO_CB(skb)->free = 0;
3709 pp = ptype->callbacks.gro_receive(&napi->gro_list, skb);
3714 if (&ptype->list == head)
3717 same_flow = NAPI_GRO_CB(skb)->same_flow;
3718 ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED;
3721 struct sk_buff *nskb = *pp;
3725 napi_gro_complete(nskb);
3732 if (NAPI_GRO_CB(skb)->flush || napi->gro_count >= MAX_GRO_SKBS)
3736 NAPI_GRO_CB(skb)->count = 1;
3737 NAPI_GRO_CB(skb)->age = jiffies;
3738 skb_shinfo(skb)->gso_size = skb_gro_len(skb);
3739 skb->next = napi->gro_list;
3740 napi->gro_list = skb;
3744 if (skb_headlen(skb) < skb_gro_offset(skb)) {
3745 int grow = skb_gro_offset(skb) - skb_headlen(skb);
3747 BUG_ON(skb->end - skb->tail < grow);
3749 memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow);
3752 skb->data_len -= grow;
3754 skb_shinfo(skb)->frags[0].page_offset += grow;
3755 skb_frag_size_sub(&skb_shinfo(skb)->frags[0], grow);
3757 if (unlikely(!skb_frag_size(&skb_shinfo(skb)->frags[0]))) {
3758 skb_frag_unref(skb, 0);
3759 memmove(skb_shinfo(skb)->frags,
3760 skb_shinfo(skb)->frags + 1,
3761 --skb_shinfo(skb)->nr_frags * sizeof(skb_frag_t));
3774 static gro_result_t napi_skb_finish(gro_result_t ret, struct sk_buff *skb)
3778 if (netif_receive_skb(skb))
3786 case GRO_MERGED_FREE:
3787 if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
3788 kmem_cache_free(skbuff_head_cache, skb);
3801 static void skb_gro_reset_offset(struct sk_buff *skb)
3803 const struct skb_shared_info *pinfo = skb_shinfo(skb);
3804 const skb_frag_t *frag0 = &pinfo->frags[0];
3806 NAPI_GRO_CB(skb)->data_offset = 0;
3807 NAPI_GRO_CB(skb)->frag0 = NULL;
3808 NAPI_GRO_CB(skb)->frag0_len = 0;
3810 if (skb->mac_header == skb->tail &&
3812 !PageHighMem(skb_frag_page(frag0))) {
3813 NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0);
3814 NAPI_GRO_CB(skb)->frag0_len = skb_frag_size(frag0);
3818 gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
3820 skb_gro_reset_offset(skb);
3822 return napi_skb_finish(dev_gro_receive(napi, skb), skb);
3824 EXPORT_SYMBOL(napi_gro_receive);
3826 static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
3828 __skb_pull(skb, skb_headlen(skb));
3829 /* restore the reserve we had after netdev_alloc_skb_ip_align() */
3830 skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb));
3832 skb->dev = napi->dev;
3838 struct sk_buff *napi_get_frags(struct napi_struct *napi)
3840 struct sk_buff *skb = napi->skb;
3843 skb = netdev_alloc_skb_ip_align(napi->dev, GRO_MAX_HEAD);
3849 EXPORT_SYMBOL(napi_get_frags);
3851 static gro_result_t napi_frags_finish(struct napi_struct *napi, struct sk_buff *skb,
3857 skb->protocol = eth_type_trans(skb, skb->dev);
3859 if (ret == GRO_HELD)
3860 skb_gro_pull(skb, -ETH_HLEN);
3861 else if (netif_receive_skb(skb))
3866 case GRO_MERGED_FREE:
3867 napi_reuse_skb(napi, skb);
3877 static struct sk_buff *napi_frags_skb(struct napi_struct *napi)
3879 struct sk_buff *skb = napi->skb;
3886 skb_reset_mac_header(skb);
3887 skb_gro_reset_offset(skb);
3889 off = skb_gro_offset(skb);
3890 hlen = off + sizeof(*eth);
3891 eth = skb_gro_header_fast(skb, off);
3892 if (skb_gro_header_hard(skb, hlen)) {
3893 eth = skb_gro_header_slow(skb, hlen, off);
3894 if (unlikely(!eth)) {
3895 napi_reuse_skb(napi, skb);
3901 skb_gro_pull(skb, sizeof(*eth));
3904 * This works because the only protocols we care about don't require
3905 * special handling. We'll fix it up properly at the end.
3907 skb->protocol = eth->h_proto;
3913 gro_result_t napi_gro_frags(struct napi_struct *napi)
3915 struct sk_buff *skb = napi_frags_skb(napi);
3920 return napi_frags_finish(napi, skb, dev_gro_receive(napi, skb));
3922 EXPORT_SYMBOL(napi_gro_frags);
3925 * net_rps_action sends any pending IPI's for rps.
3926 * Note: called with local irq disabled, but exits with local irq enabled.
3928 static void net_rps_action_and_irq_enable(struct softnet_data *sd)
3931 struct softnet_data *remsd = sd->rps_ipi_list;
3934 sd->rps_ipi_list = NULL;
3938 /* Send pending IPI's to kick RPS processing on remote cpus. */
3940 struct softnet_data *next = remsd->rps_ipi_next;
3942 if (cpu_online(remsd->cpu))
3943 __smp_call_function_single(remsd->cpu,
3952 static int process_backlog(struct napi_struct *napi, int quota)
3955 struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
3958 /* Check if we have pending ipi, its better to send them now,
3959 * not waiting net_rx_action() end.
3961 if (sd->rps_ipi_list) {
3962 local_irq_disable();
3963 net_rps_action_and_irq_enable(sd);
3966 napi->weight = weight_p;
3967 local_irq_disable();
3968 while (work < quota) {
3969 struct sk_buff *skb;
3972 while ((skb = __skb_dequeue(&sd->process_queue))) {
3974 __netif_receive_skb(skb);
3975 local_irq_disable();
3976 input_queue_head_incr(sd);
3977 if (++work >= quota) {
3984 qlen = skb_queue_len(&sd->input_pkt_queue);
3986 skb_queue_splice_tail_init(&sd->input_pkt_queue,
3987 &sd->process_queue);
3989 if (qlen < quota - work) {
3991 * Inline a custom version of __napi_complete().
3992 * only current cpu owns and manipulates this napi,
3993 * and NAPI_STATE_SCHED is the only possible flag set on backlog.
3994 * we can use a plain write instead of clear_bit(),
3995 * and we dont need an smp_mb() memory barrier.
3997 list_del(&napi->poll_list);
4000 quota = work + qlen;
4010 * __napi_schedule - schedule for receive
4011 * @n: entry to schedule
4013 * The entry's receive function will be scheduled to run
4015 void __napi_schedule(struct napi_struct *n)
4017 unsigned long flags;
4019 local_irq_save(flags);
4020 ____napi_schedule(&__get_cpu_var(softnet_data), n);
4021 local_irq_restore(flags);
4023 EXPORT_SYMBOL(__napi_schedule);
4025 void __napi_complete(struct napi_struct *n)
4027 BUG_ON(!test_bit(NAPI_STATE_SCHED, &n->state));
4028 BUG_ON(n->gro_list);
4030 list_del(&n->poll_list);
4031 smp_mb__before_clear_bit();
4032 clear_bit(NAPI_STATE_SCHED, &n->state);
4034 EXPORT_SYMBOL(__napi_complete);
4036 void napi_complete(struct napi_struct *n)
4038 unsigned long flags;
4041 * don't let napi dequeue from the cpu poll list
4042 * just in case its running on a different cpu
4044 if (unlikely(test_bit(NAPI_STATE_NPSVC, &n->state)))
4047 napi_gro_flush(n, false);
4048 local_irq_save(flags);
4050 local_irq_restore(flags);
4052 EXPORT_SYMBOL(napi_complete);
4054 void netif_napi_add(struct net_device *dev, struct napi_struct *napi,
4055 int (*poll)(struct napi_struct *, int), int weight)
4057 INIT_LIST_HEAD(&napi->poll_list);
4058 napi->gro_count = 0;
4059 napi->gro_list = NULL;
4062 napi->weight = weight;
4063 list_add(&napi->dev_list, &dev->napi_list);
4065 #ifdef CONFIG_NETPOLL
4066 spin_lock_init(&napi->poll_lock);
4067 napi->poll_owner = -1;
4069 set_bit(NAPI_STATE_SCHED, &napi->state);
4071 EXPORT_SYMBOL(netif_napi_add);
4073 void netif_napi_del(struct napi_struct *napi)
4075 struct sk_buff *skb, *next;
4077 list_del_init(&napi->dev_list);
4078 napi_free_frags(napi);
4080 for (skb = napi->gro_list; skb; skb = next) {
4086 napi->gro_list = NULL;
4087 napi->gro_count = 0;
4089 EXPORT_SYMBOL(netif_napi_del);
4091 static void net_rx_action(struct softirq_action *h)
4093 struct softnet_data *sd = &__get_cpu_var(softnet_data);
4094 unsigned long time_limit = jiffies + 2;
4095 int budget = netdev_budget;
4098 local_irq_disable();
4100 while (!list_empty(&sd->poll_list)) {
4101 struct napi_struct *n;
4104 /* If softirq window is exhuasted then punt.
4105 * Allow this to run for 2 jiffies since which will allow
4106 * an average latency of 1.5/HZ.
4108 if (unlikely(budget <= 0 || time_after(jiffies, time_limit)))
4113 /* Even though interrupts have been re-enabled, this
4114 * access is safe because interrupts can only add new
4115 * entries to the tail of this list, and only ->poll()
4116 * calls can remove this head entry from the list.
4118 n = list_first_entry(&sd->poll_list, struct napi_struct, poll_list);
4120 have = netpoll_poll_lock(n);
4124 /* This NAPI_STATE_SCHED test is for avoiding a race
4125 * with netpoll's poll_napi(). Only the entity which
4126 * obtains the lock and sees NAPI_STATE_SCHED set will
4127 * actually make the ->poll() call. Therefore we avoid
4128 * accidentally calling ->poll() when NAPI is not scheduled.
4131 if (test_bit(NAPI_STATE_SCHED, &n->state)) {
4132 work = n->poll(n, weight);
4136 WARN_ON_ONCE(work > weight);
4140 local_irq_disable();
4142 /* Drivers must not modify the NAPI state if they
4143 * consume the entire weight. In such cases this code
4144 * still "owns" the NAPI instance and therefore can
4145 * move the instance around on the list at-will.
4147 if (unlikely(work == weight)) {
4148 if (unlikely(napi_disable_pending(n))) {
4151 local_irq_disable();
4154 /* flush too old packets
4155 * If HZ < 1000, flush all packets.
4158 napi_gro_flush(n, HZ >= 1000);
4159 local_irq_disable();
4161 list_move_tail(&n->poll_list, &sd->poll_list);
4165 netpoll_poll_unlock(have);
4168 net_rps_action_and_irq_enable(sd);
4170 #ifdef CONFIG_NET_DMA
4172 * There may not be any more sk_buffs coming right now, so push
4173 * any pending DMA copies to hardware
4175 dma_issue_pending_all();
4182 __raise_softirq_irqoff(NET_RX_SOFTIRQ);
4186 struct netdev_upper {
4187 struct net_device *dev;
4189 struct list_head list;
4190 struct rcu_head rcu;
4191 struct list_head search_list;
4194 static void __append_search_uppers(struct list_head *search_list,
4195 struct net_device *dev)
4197 struct netdev_upper *upper;
4199 list_for_each_entry(upper, &dev->upper_dev_list, list) {
4200 /* check if this upper is not already in search list */
4201 if (list_empty(&upper->search_list))
4202 list_add_tail(&upper->search_list, search_list);
4206 static bool __netdev_search_upper_dev(struct net_device *dev,
4207 struct net_device *upper_dev)
4209 LIST_HEAD(search_list);
4210 struct netdev_upper *upper;
4211 struct netdev_upper *tmp;
4214 __append_search_uppers(&search_list, dev);
4215 list_for_each_entry(upper, &search_list, search_list) {
4216 if (upper->dev == upper_dev) {
4220 __append_search_uppers(&search_list, upper->dev);
4222 list_for_each_entry_safe(upper, tmp, &search_list, search_list)
4223 INIT_LIST_HEAD(&upper->search_list);
4227 static struct netdev_upper *__netdev_find_upper(struct net_device *dev,
4228 struct net_device *upper_dev)
4230 struct netdev_upper *upper;
4232 list_for_each_entry(upper, &dev->upper_dev_list, list) {
4233 if (upper->dev == upper_dev)
4240 * netdev_has_upper_dev - Check if device is linked to an upper device
4242 * @upper_dev: upper device to check
4244 * Find out if a device is linked to specified upper device and return true
4245 * in case it is. Note that this checks only immediate upper device,
4246 * not through a complete stack of devices. The caller must hold the RTNL lock.
4248 bool netdev_has_upper_dev(struct net_device *dev,
4249 struct net_device *upper_dev)
4253 return __netdev_find_upper(dev, upper_dev);
4255 EXPORT_SYMBOL(netdev_has_upper_dev);
4258 * netdev_has_any_upper_dev - Check if device is linked to some device
4261 * Find out if a device is linked to an upper device and return true in case
4262 * it is. The caller must hold the RTNL lock.
4264 bool netdev_has_any_upper_dev(struct net_device *dev)
4268 return !list_empty(&dev->upper_dev_list);
4270 EXPORT_SYMBOL(netdev_has_any_upper_dev);
4273 * netdev_master_upper_dev_get - Get master upper device
4276 * Find a master upper device and return pointer to it or NULL in case
4277 * it's not there. The caller must hold the RTNL lock.
4279 struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
4281 struct netdev_upper *upper;
4285 if (list_empty(&dev->upper_dev_list))
4288 upper = list_first_entry(&dev->upper_dev_list,
4289 struct netdev_upper, list);
4290 if (likely(upper->master))
4294 EXPORT_SYMBOL(netdev_master_upper_dev_get);
4297 * netdev_master_upper_dev_get_rcu - Get master upper device
4300 * Find a master upper device and return pointer to it or NULL in case
4301 * it's not there. The caller must hold the RCU read lock.
4303 struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev)
4305 struct netdev_upper *upper;
4307 upper = list_first_or_null_rcu(&dev->upper_dev_list,
4308 struct netdev_upper, list);
4309 if (upper && likely(upper->master))
4313 EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);
4315 static int __netdev_upper_dev_link(struct net_device *dev,
4316 struct net_device *upper_dev, bool master)
4318 struct netdev_upper *upper;
4322 if (dev == upper_dev)
4325 /* To prevent loops, check if dev is not upper device to upper_dev. */
4326 if (__netdev_search_upper_dev(upper_dev, dev))
4329 if (__netdev_find_upper(dev, upper_dev))
4332 if (master && netdev_master_upper_dev_get(dev))
4335 upper = kmalloc(sizeof(*upper), GFP_KERNEL);
4339 upper->dev = upper_dev;
4340 upper->master = master;
4341 INIT_LIST_HEAD(&upper->search_list);
4343 /* Ensure that master upper link is always the first item in list. */
4345 list_add_rcu(&upper->list, &dev->upper_dev_list);
4347 list_add_tail_rcu(&upper->list, &dev->upper_dev_list);
4348 dev_hold(upper_dev);
4354 * netdev_upper_dev_link - Add a link to the upper device
4356 * @upper_dev: new upper device
4358 * Adds a link to device which is upper to this one. The caller must hold
4359 * the RTNL lock. On a failure a negative errno code is returned.
4360 * On success the reference counts are adjusted and the function
4363 int netdev_upper_dev_link(struct net_device *dev,
4364 struct net_device *upper_dev)
4366 return __netdev_upper_dev_link(dev, upper_dev, false);
4368 EXPORT_SYMBOL(netdev_upper_dev_link);
4371 * netdev_master_upper_dev_link - Add a master link to the upper device
4373 * @upper_dev: new upper device
4375 * Adds a link to device which is upper to this one. In this case, only
4376 * one master upper device can be linked, although other non-master devices
4377 * might be linked as well. The caller must hold the RTNL lock.
4378 * On a failure a negative errno code is returned. On success the reference
4379 * counts are adjusted and the function returns zero.
4381 int netdev_master_upper_dev_link(struct net_device *dev,
4382 struct net_device *upper_dev)
4384 return __netdev_upper_dev_link(dev, upper_dev, true);
4386 EXPORT_SYMBOL(netdev_master_upper_dev_link);
4389 * netdev_upper_dev_unlink - Removes a link to upper device
4391 * @upper_dev: new upper device
4393 * Removes a link to device which is upper to this one. The caller must hold
4396 void netdev_upper_dev_unlink(struct net_device *dev,
4397 struct net_device *upper_dev)
4399 struct netdev_upper *upper;
4403 upper = __netdev_find_upper(dev, upper_dev);
4406 list_del_rcu(&upper->list);
4408 kfree_rcu(upper, rcu);
4410 EXPORT_SYMBOL(netdev_upper_dev_unlink);
4412 static void dev_change_rx_flags(struct net_device *dev, int flags)
4414 const struct net_device_ops *ops = dev->netdev_ops;
4416 if ((dev->flags & IFF_UP) && ops->ndo_change_rx_flags)
4417 ops->ndo_change_rx_flags(dev, flags);
4420 static int __dev_set_promiscuity(struct net_device *dev, int inc)
4422 unsigned int old_flags = dev->flags;
4428 dev->flags |= IFF_PROMISC;
4429 dev->promiscuity += inc;
4430 if (dev->promiscuity == 0) {
4433 * If inc causes overflow, untouch promisc and return error.
4436 dev->flags &= ~IFF_PROMISC;
4438 dev->promiscuity -= inc;
4439 pr_warn("%s: promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n",
4444 if (dev->flags != old_flags) {
4445 pr_info("device %s %s promiscuous mode\n",
4447 dev->flags & IFF_PROMISC ? "entered" : "left");
4448 if (audit_enabled) {
4449 current_uid_gid(&uid, &gid);
4450 audit_log(current->audit_context, GFP_ATOMIC,
4451 AUDIT_ANOM_PROMISCUOUS,
4452 "dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
4453 dev->name, (dev->flags & IFF_PROMISC),
4454 (old_flags & IFF_PROMISC),
4455 from_kuid(&init_user_ns, audit_get_loginuid(current)),
4456 from_kuid(&init_user_ns, uid),
4457 from_kgid(&init_user_ns, gid),
4458 audit_get_sessionid(current));
4461 dev_change_rx_flags(dev, IFF_PROMISC);
4467 * dev_set_promiscuity - update promiscuity count on a device
4471 * Add or remove promiscuity from a device. While the count in the device
4472 * remains above zero the interface remains promiscuous. Once it hits zero
4473 * the device reverts back to normal filtering operation. A negative inc
4474 * value is used to drop promiscuity on the device.
4475 * Return 0 if successful or a negative errno code on error.
4477 int dev_set_promiscuity(struct net_device *dev, int inc)
4479 unsigned int old_flags = dev->flags;
4482 err = __dev_set_promiscuity(dev, inc);
4485 if (dev->flags != old_flags)
4486 dev_set_rx_mode(dev);
4489 EXPORT_SYMBOL(dev_set_promiscuity);
4492 * dev_set_allmulti - update allmulti count on a device
4496 * Add or remove reception of all multicast frames to a device. While the
4497 * count in the device remains above zero the interface remains listening
4498 * to all interfaces. Once it hits zero the device reverts back to normal
4499 * filtering operation. A negative @inc value is used to drop the counter
4500 * when releasing a resource needing all multicasts.
4501 * Return 0 if successful or a negative errno code on error.
4504 int dev_set_allmulti(struct net_device *dev, int inc)
4506 unsigned int old_flags = dev->flags;
4510 dev->flags |= IFF_ALLMULTI;
4511 dev->allmulti += inc;
4512 if (dev->allmulti == 0) {
4515 * If inc causes overflow, untouch allmulti and return error.
4518 dev->flags &= ~IFF_ALLMULTI;
4520 dev->allmulti -= inc;
4521 pr_warn("%s: allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n",
4526 if (dev->flags ^ old_flags) {
4527 dev_change_rx_flags(dev, IFF_ALLMULTI);
4528 dev_set_rx_mode(dev);
4532 EXPORT_SYMBOL(dev_set_allmulti);
4535 * Upload unicast and multicast address lists to device and
4536 * configure RX filtering. When the device doesn't support unicast
4537 * filtering it is put in promiscuous mode while unicast addresses
4540 void __dev_set_rx_mode(struct net_device *dev)
4542 const struct net_device_ops *ops = dev->netdev_ops;
4544 /* dev_open will call this function so the list will stay sane. */
4545 if (!(dev->flags&IFF_UP))
4548 if (!netif_device_present(dev))
4551 if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
4552 /* Unicast addresses changes may only happen under the rtnl,
4553 * therefore calling __dev_set_promiscuity here is safe.
4555 if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
4556 __dev_set_promiscuity(dev, 1);
4557 dev->uc_promisc = true;
4558 } else if (netdev_uc_empty(dev) && dev->uc_promisc) {
4559 __dev_set_promiscuity(dev, -1);
4560 dev->uc_promisc = false;
4564 if (ops->ndo_set_rx_mode)
4565 ops->ndo_set_rx_mode(dev);
4568 void dev_set_rx_mode(struct net_device *dev)
4570 netif_addr_lock_bh(dev);
4571 __dev_set_rx_mode(dev);
4572 netif_addr_unlock_bh(dev);
4576 * dev_get_flags - get flags reported to userspace
4579 * Get the combination of flag bits exported through APIs to userspace.
4581 unsigned int dev_get_flags(const struct net_device *dev)
4585 flags = (dev->flags & ~(IFF_PROMISC |
4590 (dev->gflags & (IFF_PROMISC |
4593 if (netif_running(dev)) {
4594 if (netif_oper_up(dev))
4595 flags |= IFF_RUNNING;
4596 if (netif_carrier_ok(dev))
4597 flags |= IFF_LOWER_UP;
4598 if (netif_dormant(dev))
4599 flags |= IFF_DORMANT;
4604 EXPORT_SYMBOL(dev_get_flags);
4606 int __dev_change_flags(struct net_device *dev, unsigned int flags)
4608 unsigned int old_flags = dev->flags;
4614 * Set the flags on our device.
4617 dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
4618 IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
4620 (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
4624 * Load in the correct multicast list now the flags have changed.
4627 if ((old_flags ^ flags) & IFF_MULTICAST)
4628 dev_change_rx_flags(dev, IFF_MULTICAST);
4630 dev_set_rx_mode(dev);
4633 * Have we downed the interface. We handle IFF_UP ourselves
4634 * according to user attempts to set it, rather than blindly
4639 if ((old_flags ^ flags) & IFF_UP) { /* Bit is different ? */
4640 ret = ((old_flags & IFF_UP) ? __dev_close : __dev_open)(dev);
4643 dev_set_rx_mode(dev);
4646 if ((flags ^ dev->gflags) & IFF_PROMISC) {
4647 int inc = (flags & IFF_PROMISC) ? 1 : -1;
4649 dev->gflags ^= IFF_PROMISC;
4650 dev_set_promiscuity(dev, inc);
4653 /* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
4654 is important. Some (broken) drivers set IFF_PROMISC, when
4655 IFF_ALLMULTI is requested not asking us and not reporting.
4657 if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
4658 int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
4660 dev->gflags ^= IFF_ALLMULTI;
4661 dev_set_allmulti(dev, inc);
4667 void __dev_notify_flags(struct net_device *dev, unsigned int old_flags)
4669 unsigned int changes = dev->flags ^ old_flags;
4671 if (changes & IFF_UP) {
4672 if (dev->flags & IFF_UP)
4673 call_netdevice_notifiers(NETDEV_UP, dev);
4675 call_netdevice_notifiers(NETDEV_DOWN, dev);
4678 if (dev->flags & IFF_UP &&
4679 (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE)))
4680 call_netdevice_notifiers(NETDEV_CHANGE, dev);
4684 * dev_change_flags - change device settings
4686 * @flags: device state flags
4688 * Change settings on device based state flags. The flags are
4689 * in the userspace exported format.
4691 int dev_change_flags(struct net_device *dev, unsigned int flags)
4694 unsigned int changes, old_flags = dev->flags;
4696 ret = __dev_change_flags(dev, flags);
4700 changes = old_flags ^ dev->flags;
4702 rtmsg_ifinfo(RTM_NEWLINK, dev, changes);
4704 __dev_notify_flags(dev, old_flags);
4707 EXPORT_SYMBOL(dev_change_flags);
4710 * dev_set_mtu - Change maximum transfer unit
4712 * @new_mtu: new transfer unit
4714 * Change the maximum transfer size of the network device.
4716 int dev_set_mtu(struct net_device *dev, int new_mtu)
4718 const struct net_device_ops *ops = dev->netdev_ops;
4721 if (new_mtu == dev->mtu)
4724 /* MTU must be positive. */
4728 if (!netif_device_present(dev))
4732 if (ops->ndo_change_mtu)
4733 err = ops->ndo_change_mtu(dev, new_mtu);
4738 call_netdevice_notifiers(NETDEV_CHANGEMTU, dev);
4741 EXPORT_SYMBOL(dev_set_mtu);
4744 * dev_set_group - Change group this device belongs to
4746 * @new_group: group this device should belong to
4748 void dev_set_group(struct net_device *dev, int new_group)
4750 dev->group = new_group;
4752 EXPORT_SYMBOL(dev_set_group);
4755 * dev_set_mac_address - Change Media Access Control Address
4759 * Change the hardware (MAC) address of the device
4761 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa)
4763 const struct net_device_ops *ops = dev->netdev_ops;
4766 if (!ops->ndo_set_mac_address)
4768 if (sa->sa_family != dev->type)
4770 if (!netif_device_present(dev))
4772 err = ops->ndo_set_mac_address(dev, sa);
4775 dev->addr_assign_type = NET_ADDR_SET;
4776 call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
4777 add_device_randomness(dev->dev_addr, dev->addr_len);
4780 EXPORT_SYMBOL(dev_set_mac_address);
4783 * dev_change_carrier - Change device carrier
4785 * @new_carries: new value
4787 * Change device carrier
4789 int dev_change_carrier(struct net_device *dev, bool new_carrier)
4791 const struct net_device_ops *ops = dev->netdev_ops;
4793 if (!ops->ndo_change_carrier)
4795 if (!netif_device_present(dev))
4797 return ops->ndo_change_carrier(dev, new_carrier);
4799 EXPORT_SYMBOL(dev_change_carrier);
4802 * dev_new_index - allocate an ifindex
4803 * @net: the applicable net namespace
4805 * Returns a suitable unique value for a new device interface
4806 * number. The caller must hold the rtnl semaphore or the
4807 * dev_base_lock to be sure it remains unique.
4809 static int dev_new_index(struct net *net)
4811 int ifindex = net->ifindex;
4815 if (!__dev_get_by_index(net, ifindex))
4816 return net->ifindex = ifindex;
4820 /* Delayed registration/unregisteration */
4821 static LIST_HEAD(net_todo_list);
4823 static void net_set_todo(struct net_device *dev)
4825 list_add_tail(&dev->todo_list, &net_todo_list);
4828 static void rollback_registered_many(struct list_head *head)
4830 struct net_device *dev, *tmp;
4832 BUG_ON(dev_boot_phase);
4835 list_for_each_entry_safe(dev, tmp, head, unreg_list) {
4836 /* Some devices call without registering
4837 * for initialization unwind. Remove those
4838 * devices and proceed with the remaining.
4840 if (dev->reg_state == NETREG_UNINITIALIZED) {
4841 pr_debug("unregister_netdevice: device %s/%p never was registered\n",
4845 list_del(&dev->unreg_list);
4848 dev->dismantle = true;
4849 BUG_ON(dev->reg_state != NETREG_REGISTERED);
4852 /* If device is running, close it first. */
4853 dev_close_many(head);
4855 list_for_each_entry(dev, head, unreg_list) {
4856 /* And unlink it from device chain. */
4857 unlist_netdevice(dev);
4859 dev->reg_state = NETREG_UNREGISTERING;
4864 list_for_each_entry(dev, head, unreg_list) {
4865 /* Shutdown queueing discipline. */
4869 /* Notify protocols, that we are about to destroy
4870 this device. They should clean all the things.
4872 call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
4874 if (!dev->rtnl_link_ops ||
4875 dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
4876 rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
4879 * Flush the unicast and multicast chains
4884 if (dev->netdev_ops->ndo_uninit)
4885 dev->netdev_ops->ndo_uninit(dev);
4887 /* Notifier chain MUST detach us all upper devices. */
4888 WARN_ON(netdev_has_any_upper_dev(dev));
4890 /* Remove entries from kobject tree */
4891 netdev_unregister_kobject(dev);
4893 /* Remove XPS queueing entries */
4894 netif_reset_xps_queues_gt(dev, 0);
4900 list_for_each_entry(dev, head, unreg_list)
4904 static void rollback_registered(struct net_device *dev)
4908 list_add(&dev->unreg_list, &single);
4909 rollback_registered_many(&single);
4913 static netdev_features_t netdev_fix_features(struct net_device *dev,
4914 netdev_features_t features)
4916 /* Fix illegal checksum combinations */
4917 if ((features & NETIF_F_HW_CSUM) &&
4918 (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
4919 netdev_warn(dev, "mixed HW and IP checksum settings.\n");
4920 features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
4923 /* Fix illegal SG+CSUM combinations. */
4924 if ((features & NETIF_F_SG) &&
4925 !(features & NETIF_F_ALL_CSUM)) {
4927 "Dropping NETIF_F_SG since no checksum feature.\n");
4928 features &= ~NETIF_F_SG;
4931 /* TSO requires that SG is present as well. */
4932 if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
4933 netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
4934 features &= ~NETIF_F_ALL_TSO;
4937 /* TSO ECN requires that TSO is present as well. */
4938 if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
4939 features &= ~NETIF_F_TSO_ECN;
4941 /* Software GSO depends on SG. */
4942 if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
4943 netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
4944 features &= ~NETIF_F_GSO;
4947 /* UFO needs SG and checksumming */
4948 if (features & NETIF_F_UFO) {
4949 /* maybe split UFO into V4 and V6? */
4950 if (!((features & NETIF_F_GEN_CSUM) ||
4951 (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))
4952 == (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
4954 "Dropping NETIF_F_UFO since no checksum offload features.\n");
4955 features &= ~NETIF_F_UFO;
4958 if (!(features & NETIF_F_SG)) {
4960 "Dropping NETIF_F_UFO since no NETIF_F_SG feature.\n");
4961 features &= ~NETIF_F_UFO;
4968 int __netdev_update_features(struct net_device *dev)
4970 netdev_features_t features;
4975 features = netdev_get_wanted_features(dev);
4977 if (dev->netdev_ops->ndo_fix_features)
4978 features = dev->netdev_ops->ndo_fix_features(dev, features);
4980 /* driver might be less strict about feature dependencies */
4981 features = netdev_fix_features(dev, features);
4983 if (dev->features == features)
4986 netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
4987 &dev->features, &features);
4989 if (dev->netdev_ops->ndo_set_features)
4990 err = dev->netdev_ops->ndo_set_features(dev, features);
4992 if (unlikely(err < 0)) {
4994 "set_features() failed (%d); wanted %pNF, left %pNF\n",
4995 err, &features, &dev->features);
5000 dev->features = features;
5006 * netdev_update_features - recalculate device features
5007 * @dev: the device to check
5009 * Recalculate dev->features set and send notifications if it
5010 * has changed. Should be called after driver or hardware dependent
5011 * conditions might have changed that influence the features.
5013 void netdev_update_features(struct net_device *dev)
5015 if (__netdev_update_features(dev))
5016 netdev_features_change(dev);
5018 EXPORT_SYMBOL(netdev_update_features);
5021 * netdev_change_features - recalculate device features
5022 * @dev: the device to check
5024 * Recalculate dev->features set and send notifications even
5025 * if they have not changed. Should be called instead of
5026 * netdev_update_features() if also dev->vlan_features might
5027 * have changed to allow the changes to be propagated to stacked
5030 void netdev_change_features(struct net_device *dev)
5032 __netdev_update_features(dev);
5033 netdev_features_change(dev);
5035 EXPORT_SYMBOL(netdev_change_features);
5038 * netif_stacked_transfer_operstate - transfer operstate
5039 * @rootdev: the root or lower level device to transfer state from
5040 * @dev: the device to transfer operstate to
5042 * Transfer operational state from root to device. This is normally
5043 * called when a stacking relationship exists between the root
5044 * device and the device(a leaf device).
5046 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
5047 struct net_device *dev)
5049 if (rootdev->operstate == IF_OPER_DORMANT)
5050 netif_dormant_on(dev);
5052 netif_dormant_off(dev);
5054 if (netif_carrier_ok(rootdev)) {
5055 if (!netif_carrier_ok(dev))
5056 netif_carrier_on(dev);
5058 if (netif_carrier_ok(dev))
5059 netif_carrier_off(dev);
5062 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
5065 static int netif_alloc_rx_queues(struct net_device *dev)
5067 unsigned int i, count = dev->num_rx_queues;
5068 struct netdev_rx_queue *rx;
5072 rx = kcalloc(count, sizeof(struct netdev_rx_queue), GFP_KERNEL);
5078 for (i = 0; i < count; i++)
5084 static void netdev_init_one_queue(struct net_device *dev,
5085 struct netdev_queue *queue, void *_unused)
5087 /* Initialize queue lock */
5088 spin_lock_init(&queue->_xmit_lock);
5089 netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
5090 queue->xmit_lock_owner = -1;
5091 netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
5094 dql_init(&queue->dql, HZ);
5098 static int netif_alloc_netdev_queues(struct net_device *dev)
5100 unsigned int count = dev->num_tx_queues;
5101 struct netdev_queue *tx;
5105 tx = kcalloc(count, sizeof(struct netdev_queue), GFP_KERNEL);
5111 netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
5112 spin_lock_init(&dev->tx_global_lock);
5118 * register_netdevice - register a network device
5119 * @dev: device to register
5121 * Take a completed network device structure and add it to the kernel
5122 * interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
5123 * chain. 0 is returned on success. A negative errno code is returned
5124 * on a failure to set up the device, or if the name is a duplicate.
5126 * Callers must hold the rtnl semaphore. You may want
5127 * register_netdev() instead of this.
5130 * The locking appears insufficient to guarantee two parallel registers
5131 * will not get the same name.
5134 int register_netdevice(struct net_device *dev)
5137 struct net *net = dev_net(dev);
5139 BUG_ON(dev_boot_phase);
5144 /* When net_device's are persistent, this will be fatal. */
5145 BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
5148 spin_lock_init(&dev->addr_list_lock);
5149 netdev_set_addr_lockdep_class(dev);
5153 ret = dev_get_valid_name(net, dev, dev->name);
5157 /* Init, if this function is available */
5158 if (dev->netdev_ops->ndo_init) {
5159 ret = dev->netdev_ops->ndo_init(dev);
5167 if (((dev->hw_features | dev->features) & NETIF_F_HW_VLAN_FILTER) &&
5168 (!dev->netdev_ops->ndo_vlan_rx_add_vid ||
5169 !dev->netdev_ops->ndo_vlan_rx_kill_vid)) {
5170 netdev_WARN(dev, "Buggy VLAN acceleration in driver!\n");
5177 dev->ifindex = dev_new_index(net);
5178 else if (__dev_get_by_index(net, dev->ifindex))
5181 if (dev->iflink == -1)
5182 dev->iflink = dev->ifindex;
5184 /* Transfer changeable features to wanted_features and enable
5185 * software offloads (GSO and GRO).
5187 dev->hw_features |= NETIF_F_SOFT_FEATURES;
5188 dev->features |= NETIF_F_SOFT_FEATURES;
5189 dev->wanted_features = dev->features & dev->hw_features;
5191 /* Turn on no cache copy if HW is doing checksum */
5192 if (!(dev->flags & IFF_LOOPBACK)) {
5193 dev->hw_features |= NETIF_F_NOCACHE_COPY;
5194 if (dev->features & NETIF_F_ALL_CSUM) {
5195 dev->wanted_features |= NETIF_F_NOCACHE_COPY;
5196 dev->features |= NETIF_F_NOCACHE_COPY;
5200 /* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
5202 dev->vlan_features |= NETIF_F_HIGHDMA;
5204 ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
5205 ret = notifier_to_errno(ret);
5209 ret = netdev_register_kobject(dev);
5212 dev->reg_state = NETREG_REGISTERED;
5214 __netdev_update_features(dev);
5217 * Default initial state at registry is that the
5218 * device is present.
5221 set_bit(__LINK_STATE_PRESENT, &dev->state);
5223 linkwatch_init_dev(dev);
5225 dev_init_scheduler(dev);
5227 list_netdevice(dev);
5228 add_device_randomness(dev->dev_addr, dev->addr_len);
5230 /* If the device has permanent device address, driver should
5231 * set dev_addr and also addr_assign_type should be set to
5232 * NET_ADDR_PERM (default value).
5234 if (dev->addr_assign_type == NET_ADDR_PERM)
5235 memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);
5237 /* Notify protocols, that a new device appeared. */
5238 ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
5239 ret = notifier_to_errno(ret);
5241 rollback_registered(dev);
5242 dev->reg_state = NETREG_UNREGISTERED;
5245 * Prevent userspace races by waiting until the network
5246 * device is fully setup before sending notifications.
5248 if (!dev->rtnl_link_ops ||
5249 dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
5250 rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
5256 if (dev->netdev_ops->ndo_uninit)
5257 dev->netdev_ops->ndo_uninit(dev);
5260 EXPORT_SYMBOL(register_netdevice);
5263 * init_dummy_netdev - init a dummy network device for NAPI
5264 * @dev: device to init
5266 * This takes a network device structure and initialize the minimum
5267 * amount of fields so it can be used to schedule NAPI polls without
5268 * registering a full blown interface. This is to be used by drivers
5269 * that need to tie several hardware interfaces to a single NAPI
5270 * poll scheduler due to HW limitations.
5272 int init_dummy_netdev(struct net_device *dev)
5274 /* Clear everything. Note we don't initialize spinlocks
5275 * are they aren't supposed to be taken by any of the
5276 * NAPI code and this dummy netdev is supposed to be
5277 * only ever used for NAPI polls
5279 memset(dev, 0, sizeof(struct net_device));
5281 /* make sure we BUG if trying to hit standard
5282 * register/unregister code path
5284 dev->reg_state = NETREG_DUMMY;
5286 /* NAPI wants this */
5287 INIT_LIST_HEAD(&dev->napi_list);
5289 /* a dummy interface is started by default */
5290 set_bit(__LINK_STATE_PRESENT, &dev->state);
5291 set_bit(__LINK_STATE_START, &dev->state);
5293 /* Note : We dont allocate pcpu_refcnt for dummy devices,
5294 * because users of this 'device' dont need to change
5300 EXPORT_SYMBOL_GPL(init_dummy_netdev);
5304 * register_netdev - register a network device
5305 * @dev: device to register
5307 * Take a completed network device structure and add it to the kernel
5308 * interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
5309 * chain. 0 is returned on success. A negative errno code is returned
5310 * on a failure to set up the device, or if the name is a duplicate.
5312 * This is a wrapper around register_netdevice that takes the rtnl semaphore
5313 * and expands the device name if you passed a format string to
5316 int register_netdev(struct net_device *dev)
5321 err = register_netdevice(dev);
5325 EXPORT_SYMBOL(register_netdev);
5327 int netdev_refcnt_read(const struct net_device *dev)
5331 for_each_possible_cpu(i)
5332 refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
5335 EXPORT_SYMBOL(netdev_refcnt_read);
5338 * netdev_wait_allrefs - wait until all references are gone.
5339 * @dev: target net_device
5341 * This is called when unregistering network devices.
5343 * Any protocol or device that holds a reference should register
5344 * for netdevice notification, and cleanup and put back the
5345 * reference if they receive an UNREGISTER event.
5346 * We can get stuck here if buggy protocols don't correctly
5349 static void netdev_wait_allrefs(struct net_device *dev)
5351 unsigned long rebroadcast_time, warning_time;
5354 linkwatch_forget_dev(dev);
5356 rebroadcast_time = warning_time = jiffies;
5357 refcnt = netdev_refcnt_read(dev);
5359 while (refcnt != 0) {
5360 if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
5363 /* Rebroadcast unregister notification */
5364 call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
5370 call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
5371 if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
5373 /* We must not have linkwatch events
5374 * pending on unregister. If this
5375 * happens, we simply run the queue
5376 * unscheduled, resulting in a noop
5379 linkwatch_run_queue();
5384 rebroadcast_time = jiffies;
5389 refcnt = netdev_refcnt_read(dev);
5391 if (time_after(jiffies, warning_time + 10 * HZ)) {
5392 pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
5394 warning_time = jiffies;
5403 * register_netdevice(x1);
5404 * register_netdevice(x2);
5406 * unregister_netdevice(y1);
5407 * unregister_netdevice(y2);
5413 * We are invoked by rtnl_unlock().
5414 * This allows us to deal with problems:
5415 * 1) We can delete sysfs objects which invoke hotplug
5416 * without deadlocking with linkwatch via keventd.
5417 * 2) Since we run with the RTNL semaphore not held, we can sleep
5418 * safely in order to wait for the netdev refcnt to drop to zero.
5420 * We must not return until all unregister events added during
5421 * the interval the lock was held have been completed.
5423 void netdev_run_todo(void)
5425 struct list_head list;
5427 /* Snapshot list, allow later requests */
5428 list_replace_init(&net_todo_list, &list);
5433 /* Wait for rcu callbacks to finish before next phase */
5434 if (!list_empty(&list))
5437 while (!list_empty(&list)) {
5438 struct net_device *dev
5439 = list_first_entry(&list, struct net_device, todo_list);
5440 list_del(&dev->todo_list);
5443 call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
5446 if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
5447 pr_err("network todo '%s' but state %d\n",
5448 dev->name, dev->reg_state);
5453 dev->reg_state = NETREG_UNREGISTERED;
5455 on_each_cpu(flush_backlog, dev, 1);
5457 netdev_wait_allrefs(dev);
5460 BUG_ON(netdev_refcnt_read(dev));
5461 WARN_ON(rcu_access_pointer(dev->ip_ptr));
5462 WARN_ON(rcu_access_pointer(dev->ip6_ptr));
5463 WARN_ON(dev->dn_ptr);
5465 if (dev->destructor)
5466 dev->destructor(dev);
5468 /* Free network device */
5469 kobject_put(&dev->dev.kobj);
5473 /* Convert net_device_stats to rtnl_link_stats64. They have the same
5474 * fields in the same order, with only the type differing.
5476 void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
5477 const struct net_device_stats *netdev_stats)
5479 #if BITS_PER_LONG == 64
5480 BUILD_BUG_ON(sizeof(*stats64) != sizeof(*netdev_stats));
5481 memcpy(stats64, netdev_stats, sizeof(*stats64));
5483 size_t i, n = sizeof(*stats64) / sizeof(u64);
5484 const unsigned long *src = (const unsigned long *)netdev_stats;
5485 u64 *dst = (u64 *)stats64;
5487 BUILD_BUG_ON(sizeof(*netdev_stats) / sizeof(unsigned long) !=
5488 sizeof(*stats64) / sizeof(u64));
5489 for (i = 0; i < n; i++)
5493 EXPORT_SYMBOL(netdev_stats_to_stats64);
5496 * dev_get_stats - get network device statistics
5497 * @dev: device to get statistics from
5498 * @storage: place to store stats
5500 * Get network statistics from device. Return @storage.
5501 * The device driver may provide its own method by setting
5502 * dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
5503 * otherwise the internal statistics structure is used.
5505 struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
5506 struct rtnl_link_stats64 *storage)
5508 const struct net_device_ops *ops = dev->netdev_ops;
5510 if (ops->ndo_get_stats64) {
5511 memset(storage, 0, sizeof(*storage));
5512 ops->ndo_get_stats64(dev, storage);
5513 } else if (ops->ndo_get_stats) {
5514 netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
5516 netdev_stats_to_stats64(storage, &dev->stats);
5518 storage->rx_dropped += atomic_long_read(&dev->rx_dropped);
5521 EXPORT_SYMBOL(dev_get_stats);
5523 struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
5525 struct netdev_queue *queue = dev_ingress_queue(dev);
5527 #ifdef CONFIG_NET_CLS_ACT
5530 queue = kzalloc(sizeof(*queue), GFP_KERNEL);
5533 netdev_init_one_queue(dev, queue, NULL);
5534 queue->qdisc = &noop_qdisc;
5535 queue->qdisc_sleeping = &noop_qdisc;
5536 rcu_assign_pointer(dev->ingress_queue, queue);
5541 static const struct ethtool_ops default_ethtool_ops;
5543 void netdev_set_default_ethtool_ops(struct net_device *dev,
5544 const struct ethtool_ops *ops)
5546 if (dev->ethtool_ops == &default_ethtool_ops)
5547 dev->ethtool_ops = ops;
5549 EXPORT_SYMBOL_GPL(netdev_set_default_ethtool_ops);
5552 * alloc_netdev_mqs - allocate network device
5553 * @sizeof_priv: size of private data to allocate space for
5554 * @name: device name format string
5555 * @setup: callback to initialize device
5556 * @txqs: the number of TX subqueues to allocate
5557 * @rxqs: the number of RX subqueues to allocate
5559 * Allocates a struct net_device with private data area for driver use
5560 * and performs basic initialization. Also allocates subquue structs
5561 * for each queue on the device.
5563 struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
5564 void (*setup)(struct net_device *),
5565 unsigned int txqs, unsigned int rxqs)
5567 struct net_device *dev;
5569 struct net_device *p;
5571 BUG_ON(strlen(name) >= sizeof(dev->name));
5574 pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
5580 pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
5585 alloc_size = sizeof(struct net_device);
5587 /* ensure 32-byte alignment of private area */
5588 alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
5589 alloc_size += sizeof_priv;
5591 /* ensure 32-byte alignment of whole construct */
5592 alloc_size += NETDEV_ALIGN - 1;
5594 p = kzalloc(alloc_size, GFP_KERNEL);
5598 dev = PTR_ALIGN(p, NETDEV_ALIGN);
5599 dev->padded = (char *)dev - (char *)p;
5601 dev->pcpu_refcnt = alloc_percpu(int);
5602 if (!dev->pcpu_refcnt)
5605 if (dev_addr_init(dev))
5611 dev_net_set(dev, &init_net);
5613 dev->gso_max_size = GSO_MAX_SIZE;
5614 dev->gso_max_segs = GSO_MAX_SEGS;
5616 INIT_LIST_HEAD(&dev->napi_list);
5617 INIT_LIST_HEAD(&dev->unreg_list);
5618 INIT_LIST_HEAD(&dev->link_watch_list);
5619 INIT_LIST_HEAD(&dev->upper_dev_list);
5620 dev->priv_flags = IFF_XMIT_DST_RELEASE;
5623 dev->num_tx_queues = txqs;
5624 dev->real_num_tx_queues = txqs;
5625 if (netif_alloc_netdev_queues(dev))
5629 dev->num_rx_queues = rxqs;
5630 dev->real_num_rx_queues = rxqs;
5631 if (netif_alloc_rx_queues(dev))
5635 strcpy(dev->name, name);
5636 dev->group = INIT_NETDEV_GROUP;
5637 if (!dev->ethtool_ops)
5638 dev->ethtool_ops = &default_ethtool_ops;
5646 free_percpu(dev->pcpu_refcnt);
5656 EXPORT_SYMBOL(alloc_netdev_mqs);
5659 * free_netdev - free network device
5662 * This function does the last stage of destroying an allocated device
5663 * interface. The reference to the device object is released.
5664 * If this is the last reference then it will be freed.
5666 void free_netdev(struct net_device *dev)
5668 struct napi_struct *p, *n;
5670 release_net(dev_net(dev));
5677 kfree(rcu_dereference_protected(dev->ingress_queue, 1));
5679 /* Flush device addresses */
5680 dev_addr_flush(dev);
5682 list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
5685 free_percpu(dev->pcpu_refcnt);
5686 dev->pcpu_refcnt = NULL;
5688 /* Compatibility with error handling in drivers */
5689 if (dev->reg_state == NETREG_UNINITIALIZED) {
5690 kfree((char *)dev - dev->padded);
5694 BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
5695 dev->reg_state = NETREG_RELEASED;
5697 /* will free via device release */
5698 put_device(&dev->dev);
5700 EXPORT_SYMBOL(free_netdev);
5703 * synchronize_net - Synchronize with packet receive processing
5705 * Wait for packets currently being received to be done.
5706 * Does not block later packets from starting.
5708 void synchronize_net(void)
5711 if (rtnl_is_locked())
5712 synchronize_rcu_expedited();
5716 EXPORT_SYMBOL(synchronize_net);
5719 * unregister_netdevice_queue - remove device from the kernel
5723 * This function shuts down a device interface and removes it
5724 * from the kernel tables.
5725 * If head not NULL, device is queued to be unregistered later.
5727 * Callers must hold the rtnl semaphore. You may want
5728 * unregister_netdev() instead of this.
5731 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
5736 list_move_tail(&dev->unreg_list, head);
5738 rollback_registered(dev);
5739 /* Finish processing unregister after unlock */
5743 EXPORT_SYMBOL(unregister_netdevice_queue);
5746 * unregister_netdevice_many - unregister many devices
5747 * @head: list of devices
5749 void unregister_netdevice_many(struct list_head *head)
5751 struct net_device *dev;
5753 if (!list_empty(head)) {
5754 rollback_registered_many(head);
5755 list_for_each_entry(dev, head, unreg_list)
5759 EXPORT_SYMBOL(unregister_netdevice_many);
5762 * unregister_netdev - remove device from the kernel
5765 * This function shuts down a device interface and removes it
5766 * from the kernel tables.
5768 * This is just a wrapper for unregister_netdevice that takes
5769 * the rtnl semaphore. In general you want to use this and not
5770 * unregister_netdevice.
5772 void unregister_netdev(struct net_device *dev)
5775 unregister_netdevice(dev);
5778 EXPORT_SYMBOL(unregister_netdev);
5781 * dev_change_net_namespace - move device to different nethost namespace
5783 * @net: network namespace
5784 * @pat: If not NULL name pattern to try if the current device name
5785 * is already taken in the destination network namespace.
5787 * This function shuts down a device interface and moves it
5788 * to a new network namespace. On success 0 is returned, on
5789 * a failure a netagive errno code is returned.
5791 * Callers must hold the rtnl semaphore.
5794 int dev_change_net_namespace(struct net_device *dev, struct net *net, const char *pat)
5800 /* Don't allow namespace local devices to be moved. */
5802 if (dev->features & NETIF_F_NETNS_LOCAL)
5805 /* Ensure the device has been registrered */
5806 if (dev->reg_state != NETREG_REGISTERED)
5809 /* Get out if there is nothing todo */
5811 if (net_eq(dev_net(dev), net))
5814 /* Pick the destination device name, and ensure
5815 * we can use it in the destination network namespace.
5818 if (__dev_get_by_name(net, dev->name)) {
5819 /* We get here if we can't use the current device name */
5822 if (dev_get_valid_name(net, dev, pat) < 0)
5827 * And now a mini version of register_netdevice unregister_netdevice.
5830 /* If device is running close it first. */
5833 /* And unlink it from device chain */
5835 unlist_netdevice(dev);
5839 /* Shutdown queueing discipline. */
5842 /* Notify protocols, that we are about to destroy
5843 this device. They should clean all the things.
5845 Note that dev->reg_state stays at NETREG_REGISTERED.
5846 This is wanted because this way 8021q and macvlan know
5847 the device is just moving and can keep their slaves up.
5849 call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
5851 call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);
5852 rtmsg_ifinfo(RTM_DELLINK, dev, ~0U);
5855 * Flush the unicast and multicast chains
5860 /* Send a netdev-removed uevent to the old namespace */
5861 kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);
5863 /* Actually switch the network namespace */
5864 dev_net_set(dev, net);
5866 /* If there is an ifindex conflict assign a new one */
5867 if (__dev_get_by_index(net, dev->ifindex)) {
5868 int iflink = (dev->iflink == dev->ifindex);
5869 dev->ifindex = dev_new_index(net);
5871 dev->iflink = dev->ifindex;
5874 /* Send a netdev-add uevent to the new namespace */
5875 kobject_uevent(&dev->dev.kobj, KOBJ_ADD);
5877 /* Fixup kobjects */
5878 err = device_rename(&dev->dev, dev->name);
5881 /* Add the device back in the hashes */
5882 list_netdevice(dev);
5884 /* Notify protocols, that a new device appeared. */
5885 call_netdevice_notifiers(NETDEV_REGISTER, dev);
5888 * Prevent userspace races by waiting until the network
5889 * device is fully setup before sending notifications.
5891 rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U);
5898 EXPORT_SYMBOL_GPL(dev_change_net_namespace);
5900 static int dev_cpu_callback(struct notifier_block *nfb,
5901 unsigned long action,
5904 struct sk_buff **list_skb;
5905 struct sk_buff *skb;
5906 unsigned int cpu, oldcpu = (unsigned long)ocpu;
5907 struct softnet_data *sd, *oldsd;
5909 if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
5912 local_irq_disable();
5913 cpu = smp_processor_id();
5914 sd = &per_cpu(softnet_data, cpu);
5915 oldsd = &per_cpu(softnet_data, oldcpu);
5917 /* Find end of our completion_queue. */
5918 list_skb = &sd->completion_queue;
5920 list_skb = &(*list_skb)->next;
5921 /* Append completion queue from offline CPU. */
5922 *list_skb = oldsd->completion_queue;
5923 oldsd->completion_queue = NULL;
5925 /* Append output queue from offline CPU. */
5926 if (oldsd->output_queue) {
5927 *sd->output_queue_tailp = oldsd->output_queue;
5928 sd->output_queue_tailp = oldsd->output_queue_tailp;
5929 oldsd->output_queue = NULL;
5930 oldsd->output_queue_tailp = &oldsd->output_queue;
5932 /* Append NAPI poll list from offline CPU. */
5933 if (!list_empty(&oldsd->poll_list)) {
5934 list_splice_init(&oldsd->poll_list, &sd->poll_list);
5935 raise_softirq_irqoff(NET_RX_SOFTIRQ);
5938 raise_softirq_irqoff(NET_TX_SOFTIRQ);
5941 /* Process offline CPU's input_pkt_queue */
5942 while ((skb = __skb_dequeue(&oldsd->process_queue))) {
5944 input_queue_head_incr(oldsd);
5946 while ((skb = __skb_dequeue(&oldsd->input_pkt_queue))) {
5948 input_queue_head_incr(oldsd);
5956 * netdev_increment_features - increment feature set by one
5957 * @all: current feature set
5958 * @one: new feature set
5959 * @mask: mask feature set
5961 * Computes a new feature set after adding a device with feature set
5962 * @one to the master device with current feature set @all. Will not
5963 * enable anything that is off in @mask. Returns the new feature set.
5965 netdev_features_t netdev_increment_features(netdev_features_t all,
5966 netdev_features_t one, netdev_features_t mask)
5968 if (mask & NETIF_F_GEN_CSUM)
5969 mask |= NETIF_F_ALL_CSUM;
5970 mask |= NETIF_F_VLAN_CHALLENGED;
5972 all |= one & (NETIF_F_ONE_FOR_ALL|NETIF_F_ALL_CSUM) & mask;
5973 all &= one | ~NETIF_F_ALL_FOR_ALL;
5975 /* If one device supports hw checksumming, set for all. */
5976 if (all & NETIF_F_GEN_CSUM)
5977 all &= ~(NETIF_F_ALL_CSUM & ~NETIF_F_GEN_CSUM);
5981 EXPORT_SYMBOL(netdev_increment_features);
5983 static struct hlist_head *netdev_create_hash(void)
5986 struct hlist_head *hash;
5988 hash = kmalloc(sizeof(*hash) * NETDEV_HASHENTRIES, GFP_KERNEL);
5990 for (i = 0; i < NETDEV_HASHENTRIES; i++)
5991 INIT_HLIST_HEAD(&hash[i]);
5996 /* Initialize per network namespace state */
5997 static int __net_init netdev_init(struct net *net)
5999 if (net != &init_net)
6000 INIT_LIST_HEAD(&net->dev_base_head);
6002 net->dev_name_head = netdev_create_hash();
6003 if (net->dev_name_head == NULL)
6006 net->dev_index_head = netdev_create_hash();
6007 if (net->dev_index_head == NULL)
6013 kfree(net->dev_name_head);
6019 * netdev_drivername - network driver for the device
6020 * @dev: network device
6022 * Determine network driver for device.
6024 const char *netdev_drivername(const struct net_device *dev)
6026 const struct device_driver *driver;
6027 const struct device *parent;
6028 const char *empty = "";
6030 parent = dev->dev.parent;
6034 driver = parent->driver;
6035 if (driver && driver->name)
6036 return driver->name;
6040 static int __netdev_printk(const char *level, const struct net_device *dev,
6041 struct va_format *vaf)
6045 if (dev && dev->dev.parent) {
6046 r = dev_printk_emit(level[1] - '0',
6049 dev_driver_string(dev->dev.parent),
6050 dev_name(dev->dev.parent),
6051 netdev_name(dev), vaf);
6053 r = printk("%s%s: %pV", level, netdev_name(dev), vaf);
6055 r = printk("%s(NULL net_device): %pV", level, vaf);
6061 int netdev_printk(const char *level, const struct net_device *dev,
6062 const char *format, ...)
6064 struct va_format vaf;
6068 va_start(args, format);
6073 r = __netdev_printk(level, dev, &vaf);
6079 EXPORT_SYMBOL(netdev_printk);
6081 #define define_netdev_printk_level(func, level) \
6082 int func(const struct net_device *dev, const char *fmt, ...) \
6085 struct va_format vaf; \
6088 va_start(args, fmt); \
6093 r = __netdev_printk(level, dev, &vaf); \
6099 EXPORT_SYMBOL(func);
6101 define_netdev_printk_level(netdev_emerg, KERN_EMERG);
6102 define_netdev_printk_level(netdev_alert, KERN_ALERT);
6103 define_netdev_printk_level(netdev_crit, KERN_CRIT);
6104 define_netdev_printk_level(netdev_err, KERN_ERR);
6105 define_netdev_printk_level(netdev_warn, KERN_WARNING);
6106 define_netdev_printk_level(netdev_notice, KERN_NOTICE);
6107 define_netdev_printk_level(netdev_info, KERN_INFO);
6109 static void __net_exit netdev_exit(struct net *net)
6111 kfree(net->dev_name_head);
6112 kfree(net->dev_index_head);
6115 static struct pernet_operations __net_initdata netdev_net_ops = {
6116 .init = netdev_init,
6117 .exit = netdev_exit,
6120 static void __net_exit default_device_exit(struct net *net)
6122 struct net_device *dev, *aux;
6124 * Push all migratable network devices back to the
6125 * initial network namespace
6128 for_each_netdev_safe(net, dev, aux) {
6130 char fb_name[IFNAMSIZ];
6132 /* Ignore unmoveable devices (i.e. loopback) */
6133 if (dev->features & NETIF_F_NETNS_LOCAL)
6136 /* Leave virtual devices for the generic cleanup */
6137 if (dev->rtnl_link_ops)
6140 /* Push remaining network devices to init_net */
6141 snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
6142 err = dev_change_net_namespace(dev, &init_net, fb_name);
6144 pr_emerg("%s: failed to move %s to init_net: %d\n",
6145 __func__, dev->name, err);
6152 static void __net_exit default_device_exit_batch(struct list_head *net_list)
6154 /* At exit all network devices most be removed from a network
6155 * namespace. Do this in the reverse order of registration.
6156 * Do this across as many network namespaces as possible to
6157 * improve batching efficiency.
6159 struct net_device *dev;
6161 LIST_HEAD(dev_kill_list);
6164 list_for_each_entry(net, net_list, exit_list) {
6165 for_each_netdev_reverse(net, dev) {
6166 if (dev->rtnl_link_ops)
6167 dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
6169 unregister_netdevice_queue(dev, &dev_kill_list);
6172 unregister_netdevice_many(&dev_kill_list);
6173 list_del(&dev_kill_list);
6177 static struct pernet_operations __net_initdata default_device_ops = {
6178 .exit = default_device_exit,
6179 .exit_batch = default_device_exit_batch,
6183 * Initialize the DEV module. At boot time this walks the device list and
6184 * unhooks any devices that fail to initialise (normally hardware not
6185 * present) and leaves us with a valid list of present and active devices.
6190 * This is called single threaded during boot, so no need
6191 * to take the rtnl semaphore.
6193 static int __init net_dev_init(void)
6195 int i, rc = -ENOMEM;
6197 BUG_ON(!dev_boot_phase);
6199 if (dev_proc_init())
6202 if (netdev_kobject_init())
6205 INIT_LIST_HEAD(&ptype_all);
6206 for (i = 0; i < PTYPE_HASH_SIZE; i++)
6207 INIT_LIST_HEAD(&ptype_base[i]);
6209 INIT_LIST_HEAD(&offload_base);
6211 if (register_pernet_subsys(&netdev_net_ops))
6215 * Initialise the packet receive queues.
6218 for_each_possible_cpu(i) {
6219 struct softnet_data *sd = &per_cpu(softnet_data, i);
6221 memset(sd, 0, sizeof(*sd));
6222 skb_queue_head_init(&sd->input_pkt_queue);
6223 skb_queue_head_init(&sd->process_queue);
6224 sd->completion_queue = NULL;
6225 INIT_LIST_HEAD(&sd->poll_list);
6226 sd->output_queue = NULL;
6227 sd->output_queue_tailp = &sd->output_queue;
6229 sd->csd.func = rps_trigger_softirq;
6235 sd->backlog.poll = process_backlog;
6236 sd->backlog.weight = weight_p;
6237 sd->backlog.gro_list = NULL;
6238 sd->backlog.gro_count = 0;
6243 /* The loopback device is special if any other network devices
6244 * is present in a network namespace the loopback device must
6245 * be present. Since we now dynamically allocate and free the
6246 * loopback device ensure this invariant is maintained by
6247 * keeping the loopback device as the first device on the
6248 * list of network devices. Ensuring the loopback devices
6249 * is the first device that appears and the last network device
6252 if (register_pernet_device(&loopback_net_ops))
6255 if (register_pernet_device(&default_device_ops))
6258 open_softirq(NET_TX_SOFTIRQ, net_tx_action);
6259 open_softirq(NET_RX_SOFTIRQ, net_rx_action);
6261 hotcpu_notifier(dev_cpu_callback, 0);
6268 subsys_initcall(net_dev_init);