3 * Linux ethernet bridge
6 * Lennert Buytenhek <buytenh@gnu.org>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
14 #include <linux/kernel.h>
15 #include <linux/init.h>
16 #include <linux/rculist.h>
17 #include <linux/spinlock.h>
18 #include <linux/times.h>
19 #include <linux/netdevice.h>
20 #include <linux/etherdevice.h>
21 #include <linux/jhash.h>
22 #include <linux/random.h>
23 #include <linux/slab.h>
24 #include <linux/atomic.h>
25 #include <asm/unaligned.h>
26 #include <linux/if_vlan.h>
27 #include "br_private.h"
29 static struct kmem_cache
*br_fdb_cache __read_mostly
;
30 static int fdb_insert(struct net_bridge
*br
, struct net_bridge_port
*source
,
31 const unsigned char *addr
, u16 vid
);
32 static void fdb_notify(struct net_bridge
*br
,
33 const struct net_bridge_fdb_entry
*, int);
35 static u32 fdb_salt __read_mostly
;
37 int __init
br_fdb_init(void)
39 br_fdb_cache
= kmem_cache_create("bridge_fdb_cache",
40 sizeof(struct net_bridge_fdb_entry
),
42 SLAB_HWCACHE_ALIGN
, NULL
);
46 get_random_bytes(&fdb_salt
, sizeof(fdb_salt
));
50 void br_fdb_fini(void)
52 kmem_cache_destroy(br_fdb_cache
);
56 /* if topology_changing then use forward_delay (default 15 sec)
57 * otherwise keep longer (default 5 minutes)
59 static inline unsigned long hold_time(const struct net_bridge
*br
)
61 return br
->topology_change
? br
->forward_delay
: br
->ageing_time
;
64 static inline int has_expired(const struct net_bridge
*br
,
65 const struct net_bridge_fdb_entry
*fdb
)
67 return !fdb
->is_static
&&
68 time_before_eq(fdb
->updated
+ hold_time(br
), jiffies
);
71 static inline int br_mac_hash(const unsigned char *mac
, __u16 vid
)
73 /* use 1 byte of OUI and 3 bytes of NIC */
74 u32 key
= get_unaligned((u32
*)(mac
+ 2));
75 return jhash_2words(key
, vid
, fdb_salt
) & (BR_HASH_SIZE
- 1);
78 static void fdb_rcu_free(struct rcu_head
*head
)
80 struct net_bridge_fdb_entry
*ent
81 = container_of(head
, struct net_bridge_fdb_entry
, rcu
);
82 kmem_cache_free(br_fdb_cache
, ent
);
85 static void fdb_delete(struct net_bridge
*br
, struct net_bridge_fdb_entry
*f
)
87 hlist_del_rcu(&f
->hlist
);
88 fdb_notify(br
, f
, RTM_DELNEIGH
);
89 call_rcu(&f
->rcu
, fdb_rcu_free
);
92 void br_fdb_changeaddr(struct net_bridge_port
*p
, const unsigned char *newaddr
)
94 struct net_bridge
*br
= p
->br
;
95 bool no_vlan
= (nbp_get_vlan_info(p
) == NULL
) ? true : false;
98 spin_lock_bh(&br
->hash_lock
);
100 /* Search all chains since old address/hash is unknown */
101 for (i
= 0; i
< BR_HASH_SIZE
; i
++) {
102 struct hlist_node
*h
;
103 hlist_for_each(h
, &br
->hash
[i
]) {
104 struct net_bridge_fdb_entry
*f
;
106 f
= hlist_entry(h
, struct net_bridge_fdb_entry
, hlist
);
107 if (f
->dst
== p
&& f
->is_local
) {
108 /* maybe another port has same hw addr? */
109 struct net_bridge_port
*op
;
110 u16 vid
= f
->vlan_id
;
111 list_for_each_entry(op
, &br
->port_list
, list
) {
113 ether_addr_equal(op
->dev
->dev_addr
,
115 nbp_vlan_find(op
, vid
)) {
124 /* insert new address, may fail if invalid
127 fdb_insert(br
, p
, newaddr
, vid
);
129 /* if this port has no vlan information
130 * configured, we can safely be done at
140 spin_unlock_bh(&br
->hash_lock
);
143 void br_fdb_change_mac_address(struct net_bridge
*br
, const u8
*newaddr
)
145 struct net_bridge_fdb_entry
*f
;
146 struct net_port_vlans
*pv
;
149 /* If old entry was unassociated with any port, then delete it. */
150 f
= __br_fdb_get(br
, br
->dev
->dev_addr
, 0);
151 if (f
&& f
->is_local
&& !f
->dst
)
154 fdb_insert(br
, NULL
, newaddr
, 0);
156 /* Now remove and add entries for every VLAN configured on the
157 * bridge. This function runs under RTNL so the bitmap will not
158 * change from under us.
160 pv
= br_get_vlan_info(br
);
164 for (vid
= find_next_bit(pv
->vlan_bitmap
, BR_VLAN_BITMAP_LEN
, vid
);
165 vid
< BR_VLAN_BITMAP_LEN
;
166 vid
= find_next_bit(pv
->vlan_bitmap
, BR_VLAN_BITMAP_LEN
, vid
+1)) {
167 f
= __br_fdb_get(br
, br
->dev
->dev_addr
, vid
);
168 if (f
&& f
->is_local
&& !f
->dst
)
170 fdb_insert(br
, NULL
, newaddr
, vid
);
174 void br_fdb_cleanup(unsigned long _data
)
176 struct net_bridge
*br
= (struct net_bridge
*)_data
;
177 unsigned long delay
= hold_time(br
);
178 unsigned long next_timer
= jiffies
+ br
->ageing_time
;
181 spin_lock(&br
->hash_lock
);
182 for (i
= 0; i
< BR_HASH_SIZE
; i
++) {
183 struct net_bridge_fdb_entry
*f
;
184 struct hlist_node
*n
;
186 hlist_for_each_entry_safe(f
, n
, &br
->hash
[i
], hlist
) {
187 unsigned long this_timer
;
190 this_timer
= f
->updated
+ delay
;
191 if (time_before_eq(this_timer
, jiffies
))
193 else if (time_before(this_timer
, next_timer
))
194 next_timer
= this_timer
;
197 spin_unlock(&br
->hash_lock
);
199 mod_timer(&br
->gc_timer
, round_jiffies_up(next_timer
));
202 /* Completely flush all dynamic entries in forwarding database.*/
203 void br_fdb_flush(struct net_bridge
*br
)
207 spin_lock_bh(&br
->hash_lock
);
208 for (i
= 0; i
< BR_HASH_SIZE
; i
++) {
209 struct net_bridge_fdb_entry
*f
;
210 struct hlist_node
*n
;
211 hlist_for_each_entry_safe(f
, n
, &br
->hash
[i
], hlist
) {
216 spin_unlock_bh(&br
->hash_lock
);
219 /* Flush all entries referring to a specific port.
220 * if do_all is set also flush static entries
222 void br_fdb_delete_by_port(struct net_bridge
*br
,
223 const struct net_bridge_port
*p
,
228 spin_lock_bh(&br
->hash_lock
);
229 for (i
= 0; i
< BR_HASH_SIZE
; i
++) {
230 struct hlist_node
*h
, *g
;
232 hlist_for_each_safe(h
, g
, &br
->hash
[i
]) {
233 struct net_bridge_fdb_entry
*f
234 = hlist_entry(h
, struct net_bridge_fdb_entry
, hlist
);
238 if (f
->is_static
&& !do_all
)
241 * if multiple ports all have the same device address
242 * then when one port is deleted, assign
243 * the local entry to other port
246 struct net_bridge_port
*op
;
247 list_for_each_entry(op
, &br
->port_list
, list
) {
249 ether_addr_equal(op
->dev
->dev_addr
,
261 spin_unlock_bh(&br
->hash_lock
);
264 /* No locking or refcounting, assumes caller has rcu_read_lock */
265 struct net_bridge_fdb_entry
*__br_fdb_get(struct net_bridge
*br
,
266 const unsigned char *addr
,
269 struct net_bridge_fdb_entry
*fdb
;
271 hlist_for_each_entry_rcu(fdb
,
272 &br
->hash
[br_mac_hash(addr
, vid
)], hlist
) {
273 if (ether_addr_equal(fdb
->addr
.addr
, addr
) &&
274 fdb
->vlan_id
== vid
) {
275 if (unlikely(has_expired(br
, fdb
)))
284 #if IS_ENABLED(CONFIG_ATM_LANE)
285 /* Interface used by ATM LANE hook to test
286 * if an addr is on some other bridge port */
287 int br_fdb_test_addr(struct net_device
*dev
, unsigned char *addr
)
289 struct net_bridge_fdb_entry
*fdb
;
290 struct net_bridge_port
*port
;
294 port
= br_port_get_rcu(dev
);
298 fdb
= __br_fdb_get(port
->br
, addr
, 0);
299 ret
= fdb
&& fdb
->dst
&& fdb
->dst
->dev
!= dev
&&
300 fdb
->dst
->state
== BR_STATE_FORWARDING
;
306 #endif /* CONFIG_ATM_LANE */
309 * Fill buffer with forwarding table records in
312 int br_fdb_fillbuf(struct net_bridge
*br
, void *buf
,
313 unsigned long maxnum
, unsigned long skip
)
315 struct __fdb_entry
*fe
= buf
;
317 struct net_bridge_fdb_entry
*f
;
319 memset(buf
, 0, maxnum
*sizeof(struct __fdb_entry
));
322 for (i
= 0; i
< BR_HASH_SIZE
; i
++) {
323 hlist_for_each_entry_rcu(f
, &br
->hash
[i
], hlist
) {
327 if (has_expired(br
, f
))
330 /* ignore pseudo entry for local MAC address */
339 /* convert from internal format to API */
340 memcpy(fe
->mac_addr
, f
->addr
.addr
, ETH_ALEN
);
342 /* due to ABI compat need to split into hi/lo */
343 fe
->port_no
= f
->dst
->port_no
;
344 fe
->port_hi
= f
->dst
->port_no
>> 8;
346 fe
->is_local
= f
->is_local
;
348 fe
->ageing_timer_value
= jiffies_delta_to_clock_t(jiffies
- f
->updated
);
360 static struct net_bridge_fdb_entry
*fdb_find(struct hlist_head
*head
,
361 const unsigned char *addr
,
364 struct net_bridge_fdb_entry
*fdb
;
366 hlist_for_each_entry(fdb
, head
, hlist
) {
367 if (ether_addr_equal(fdb
->addr
.addr
, addr
) &&
374 static struct net_bridge_fdb_entry
*fdb_find_rcu(struct hlist_head
*head
,
375 const unsigned char *addr
,
378 struct net_bridge_fdb_entry
*fdb
;
380 hlist_for_each_entry_rcu(fdb
, head
, hlist
) {
381 if (ether_addr_equal(fdb
->addr
.addr
, addr
) &&
388 static struct net_bridge_fdb_entry
*fdb_create(struct hlist_head
*head
,
389 struct net_bridge_port
*source
,
390 const unsigned char *addr
,
393 struct net_bridge_fdb_entry
*fdb
;
395 fdb
= kmem_cache_alloc(br_fdb_cache
, GFP_ATOMIC
);
397 memcpy(fdb
->addr
.addr
, addr
, ETH_ALEN
);
402 fdb
->updated
= fdb
->used
= jiffies
;
403 hlist_add_head_rcu(&fdb
->hlist
, head
);
408 static int fdb_insert(struct net_bridge
*br
, struct net_bridge_port
*source
,
409 const unsigned char *addr
, u16 vid
)
411 struct hlist_head
*head
= &br
->hash
[br_mac_hash(addr
, vid
)];
412 struct net_bridge_fdb_entry
*fdb
;
414 if (!is_valid_ether_addr(addr
))
417 fdb
= fdb_find(head
, addr
, vid
);
419 /* it is okay to have multiple ports with same
420 * address, just use the first one.
424 br_warn(br
, "adding interface %s with same address "
425 "as a received packet\n",
430 fdb
= fdb_create(head
, source
, addr
, vid
);
434 fdb
->is_local
= fdb
->is_static
= 1;
435 fdb_notify(br
, fdb
, RTM_NEWNEIGH
);
439 /* Add entry for local address of interface */
440 int br_fdb_insert(struct net_bridge
*br
, struct net_bridge_port
*source
,
441 const unsigned char *addr
, u16 vid
)
445 spin_lock_bh(&br
->hash_lock
);
446 ret
= fdb_insert(br
, source
, addr
, vid
);
447 spin_unlock_bh(&br
->hash_lock
);
451 void br_fdb_update(struct net_bridge
*br
, struct net_bridge_port
*source
,
452 const unsigned char *addr
, u16 vid
)
454 struct hlist_head
*head
= &br
->hash
[br_mac_hash(addr
, vid
)];
455 struct net_bridge_fdb_entry
*fdb
;
457 /* some users want to always flood. */
458 if (hold_time(br
) == 0)
461 /* ignore packets unless we are using this port */
462 if (!(source
->state
== BR_STATE_LEARNING
||
463 source
->state
== BR_STATE_FORWARDING
))
466 fdb
= fdb_find_rcu(head
, addr
, vid
);
468 /* attempt to update an entry for a local interface */
469 if (unlikely(fdb
->is_local
)) {
471 br_warn(br
, "received packet on %s with "
472 "own address as source address\n",
475 /* fastpath: update of existing entry */
477 fdb
->updated
= jiffies
;
480 spin_lock(&br
->hash_lock
);
481 if (likely(!fdb_find(head
, addr
, vid
))) {
482 fdb
= fdb_create(head
, source
, addr
, vid
);
484 fdb_notify(br
, fdb
, RTM_NEWNEIGH
);
486 /* else we lose race and someone else inserts
487 * it first, don't bother updating
489 spin_unlock(&br
->hash_lock
);
493 static int fdb_to_nud(const struct net_bridge_fdb_entry
*fdb
)
496 return NUD_PERMANENT
;
497 else if (fdb
->is_static
)
499 else if (has_expired(fdb
->dst
->br
, fdb
))
502 return NUD_REACHABLE
;
505 static int fdb_fill_info(struct sk_buff
*skb
, const struct net_bridge
*br
,
506 const struct net_bridge_fdb_entry
*fdb
,
507 u32 portid
, u32 seq
, int type
, unsigned int flags
)
509 unsigned long now
= jiffies
;
510 struct nda_cacheinfo ci
;
511 struct nlmsghdr
*nlh
;
514 nlh
= nlmsg_put(skb
, portid
, seq
, type
, sizeof(*ndm
), flags
);
518 ndm
= nlmsg_data(nlh
);
519 ndm
->ndm_family
= AF_BRIDGE
;
524 ndm
->ndm_ifindex
= fdb
->dst
? fdb
->dst
->dev
->ifindex
: br
->dev
->ifindex
;
525 ndm
->ndm_state
= fdb_to_nud(fdb
);
527 if (nla_put(skb
, NDA_LLADDR
, ETH_ALEN
, &fdb
->addr
))
528 goto nla_put_failure
;
529 ci
.ndm_used
= jiffies_to_clock_t(now
- fdb
->used
);
530 ci
.ndm_confirmed
= 0;
531 ci
.ndm_updated
= jiffies_to_clock_t(now
- fdb
->updated
);
533 if (nla_put(skb
, NDA_CACHEINFO
, sizeof(ci
), &ci
))
534 goto nla_put_failure
;
536 if (nla_put(skb
, NDA_VLAN
, sizeof(u16
), &fdb
->vlan_id
))
537 goto nla_put_failure
;
539 return nlmsg_end(skb
, nlh
);
542 nlmsg_cancel(skb
, nlh
);
546 static inline size_t fdb_nlmsg_size(void)
548 return NLMSG_ALIGN(sizeof(struct ndmsg
))
549 + nla_total_size(ETH_ALEN
) /* NDA_LLADDR */
550 + nla_total_size(sizeof(u16
)) /* NDA_VLAN */
551 + nla_total_size(sizeof(struct nda_cacheinfo
));
554 static void fdb_notify(struct net_bridge
*br
,
555 const struct net_bridge_fdb_entry
*fdb
, int type
)
557 struct net
*net
= dev_net(br
->dev
);
561 skb
= nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC
);
565 err
= fdb_fill_info(skb
, br
, fdb
, 0, 0, type
, 0);
567 /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
568 WARN_ON(err
== -EMSGSIZE
);
572 rtnl_notify(skb
, net
, 0, RTNLGRP_NEIGH
, NULL
, GFP_ATOMIC
);
576 rtnl_set_sk_err(net
, RTNLGRP_NEIGH
, err
);
579 /* Dump information about entries, in response to GETNEIGH */
580 int br_fdb_dump(struct sk_buff
*skb
,
581 struct netlink_callback
*cb
,
582 struct net_device
*dev
,
585 struct net_bridge
*br
= netdev_priv(dev
);
588 if (!(dev
->priv_flags
& IFF_EBRIDGE
))
591 for (i
= 0; i
< BR_HASH_SIZE
; i
++) {
592 struct net_bridge_fdb_entry
*f
;
594 hlist_for_each_entry_rcu(f
, &br
->hash
[i
], hlist
) {
595 if (idx
< cb
->args
[0])
598 if (fdb_fill_info(skb
, br
, f
,
599 NETLINK_CB(cb
->skb
).portid
,
613 /* Update (create or replace) forwarding database entry */
614 static int fdb_add_entry(struct net_bridge_port
*source
, const __u8
*addr
,
615 __u16 state
, __u16 flags
, __u16 vid
)
617 struct net_bridge
*br
= source
->br
;
618 struct hlist_head
*head
= &br
->hash
[br_mac_hash(addr
, vid
)];
619 struct net_bridge_fdb_entry
*fdb
;
621 fdb
= fdb_find(head
, addr
, vid
);
623 if (!(flags
& NLM_F_CREATE
))
626 fdb
= fdb_create(head
, source
, addr
, vid
);
629 fdb_notify(br
, fdb
, RTM_NEWNEIGH
);
631 if (flags
& NLM_F_EXCL
)
635 if (fdb_to_nud(fdb
) != state
) {
636 if (state
& NUD_PERMANENT
)
637 fdb
->is_local
= fdb
->is_static
= 1;
638 else if (state
& NUD_NOARP
) {
642 fdb
->is_local
= fdb
->is_static
= 0;
644 fdb
->updated
= fdb
->used
= jiffies
;
645 fdb_notify(br
, fdb
, RTM_NEWNEIGH
);
651 static int __br_fdb_add(struct ndmsg
*ndm
, struct net_bridge_port
*p
,
652 const unsigned char *addr
, u16 nlh_flags
, u16 vid
)
656 if (ndm
->ndm_flags
& NTF_USE
) {
658 br_fdb_update(p
->br
, p
, addr
, vid
);
661 spin_lock_bh(&p
->br
->hash_lock
);
662 err
= fdb_add_entry(p
, addr
, ndm
->ndm_state
,
664 spin_unlock_bh(&p
->br
->hash_lock
);
670 /* Add new permanent fdb entry with RTM_NEWNEIGH */
671 int br_fdb_add(struct ndmsg
*ndm
, struct nlattr
*tb
[],
672 struct net_device
*dev
,
673 const unsigned char *addr
, u16 nlh_flags
)
675 struct net_bridge_port
*p
;
677 struct net_port_vlans
*pv
;
678 unsigned short vid
= VLAN_N_VID
;
680 if (!(ndm
->ndm_state
& (NUD_PERMANENT
|NUD_NOARP
|NUD_REACHABLE
))) {
681 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm
->ndm_state
);
686 if (nla_len(tb
[NDA_VLAN
]) != sizeof(unsigned short)) {
687 pr_info("bridge: RTM_NEWNEIGH with invalid vlan\n");
691 vid
= nla_get_u16(tb
[NDA_VLAN
]);
693 if (vid
>= VLAN_N_VID
) {
694 pr_info("bridge: RTM_NEWNEIGH with invalid vlan id %d\n",
700 p
= br_port_get_rtnl(dev
);
702 pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
707 pv
= nbp_get_vlan_info(p
);
708 if (vid
!= VLAN_N_VID
) {
709 if (!pv
|| !test_bit(vid
, pv
->vlan_bitmap
)) {
710 pr_info("bridge: RTM_NEWNEIGH with unconfigured "
711 "vlan %d on port %s\n", vid
, dev
->name
);
715 /* VID was specified, so use it. */
716 err
= __br_fdb_add(ndm
, p
, addr
, nlh_flags
, vid
);
718 if (!pv
|| bitmap_empty(pv
->vlan_bitmap
, BR_VLAN_BITMAP_LEN
)) {
719 err
= __br_fdb_add(ndm
, p
, addr
, nlh_flags
, 0);
723 /* We have vlans configured on this port and user didn't
724 * specify a VLAN. To be nice, add/update entry for every
727 vid
= find_first_bit(pv
->vlan_bitmap
, BR_VLAN_BITMAP_LEN
);
728 while (vid
< BR_VLAN_BITMAP_LEN
) {
729 err
= __br_fdb_add(ndm
, p
, addr
, nlh_flags
, vid
);
732 vid
= find_next_bit(pv
->vlan_bitmap
,
733 BR_VLAN_BITMAP_LEN
, vid
+1);
741 int fdb_delete_by_addr(struct net_bridge
*br
, const u8
*addr
,
744 struct hlist_head
*head
= &br
->hash
[br_mac_hash(addr
, vlan
)];
745 struct net_bridge_fdb_entry
*fdb
;
747 fdb
= fdb_find(head
, addr
, vlan
);
755 static int __br_fdb_delete(struct net_bridge_port
*p
,
756 const unsigned char *addr
, u16 vid
)
760 spin_lock_bh(&p
->br
->hash_lock
);
761 err
= fdb_delete_by_addr(p
->br
, addr
, vid
);
762 spin_unlock_bh(&p
->br
->hash_lock
);
767 /* Remove neighbor entry with RTM_DELNEIGH */
768 int br_fdb_delete(struct ndmsg
*ndm
, struct nlattr
*tb
[],
769 struct net_device
*dev
,
770 const unsigned char *addr
)
772 struct net_bridge_port
*p
;
774 struct net_port_vlans
*pv
;
775 unsigned short vid
= VLAN_N_VID
;
778 if (nla_len(tb
[NDA_VLAN
]) != sizeof(unsigned short)) {
779 pr_info("bridge: RTM_NEWNEIGH with invalid vlan\n");
783 vid
= nla_get_u16(tb
[NDA_VLAN
]);
785 if (vid
>= VLAN_N_VID
) {
786 pr_info("bridge: RTM_NEWNEIGH with invalid vlan id %d\n",
791 p
= br_port_get_rtnl(dev
);
793 pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
798 pv
= nbp_get_vlan_info(p
);
799 if (vid
!= VLAN_N_VID
) {
800 if (!pv
|| !test_bit(vid
, pv
->vlan_bitmap
)) {
801 pr_info("bridge: RTM_DELNEIGH with unconfigured "
802 "vlan %d on port %s\n", vid
, dev
->name
);
806 err
= __br_fdb_delete(p
, addr
, vid
);
808 if (!pv
|| bitmap_empty(pv
->vlan_bitmap
, BR_VLAN_BITMAP_LEN
)) {
809 err
= __br_fdb_delete(p
, addr
, 0);
813 /* We have vlans configured on this port and user didn't
814 * specify a VLAN. To be nice, add/update entry for every
818 vid
= find_first_bit(pv
->vlan_bitmap
, BR_VLAN_BITMAP_LEN
);
819 while (vid
< BR_VLAN_BITMAP_LEN
) {
820 err
&= __br_fdb_delete(p
, addr
, vid
);
821 vid
= find_next_bit(pv
->vlan_bitmap
,
822 BR_VLAN_BITMAP_LEN
, vid
+1);