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_each_set_bit_from(vid
, pv
->vlan_bitmap
, BR_VLAN_BITMAP_LEN
) {
165 f
= __br_fdb_get(br
, br
->dev
->dev_addr
, vid
);
166 if (f
&& f
->is_local
&& !f
->dst
)
168 fdb_insert(br
, NULL
, newaddr
, vid
);
172 void br_fdb_cleanup(unsigned long _data
)
174 struct net_bridge
*br
= (struct net_bridge
*)_data
;
175 unsigned long delay
= hold_time(br
);
176 unsigned long next_timer
= jiffies
+ br
->ageing_time
;
179 spin_lock(&br
->hash_lock
);
180 for (i
= 0; i
< BR_HASH_SIZE
; i
++) {
181 struct net_bridge_fdb_entry
*f
;
182 struct hlist_node
*n
;
184 hlist_for_each_entry_safe(f
, n
, &br
->hash
[i
], hlist
) {
185 unsigned long this_timer
;
188 this_timer
= f
->updated
+ delay
;
189 if (time_before_eq(this_timer
, jiffies
))
191 else if (time_before(this_timer
, next_timer
))
192 next_timer
= this_timer
;
195 spin_unlock(&br
->hash_lock
);
197 mod_timer(&br
->gc_timer
, round_jiffies_up(next_timer
));
200 /* Completely flush all dynamic entries in forwarding database.*/
201 void br_fdb_flush(struct net_bridge
*br
)
205 spin_lock_bh(&br
->hash_lock
);
206 for (i
= 0; i
< BR_HASH_SIZE
; i
++) {
207 struct net_bridge_fdb_entry
*f
;
208 struct hlist_node
*n
;
209 hlist_for_each_entry_safe(f
, n
, &br
->hash
[i
], hlist
) {
214 spin_unlock_bh(&br
->hash_lock
);
217 /* Flush all entries referring to a specific port.
218 * if do_all is set also flush static entries
220 void br_fdb_delete_by_port(struct net_bridge
*br
,
221 const struct net_bridge_port
*p
,
226 spin_lock_bh(&br
->hash_lock
);
227 for (i
= 0; i
< BR_HASH_SIZE
; i
++) {
228 struct hlist_node
*h
, *g
;
230 hlist_for_each_safe(h
, g
, &br
->hash
[i
]) {
231 struct net_bridge_fdb_entry
*f
232 = hlist_entry(h
, struct net_bridge_fdb_entry
, hlist
);
236 if (f
->is_static
&& !do_all
)
239 * if multiple ports all have the same device address
240 * then when one port is deleted, assign
241 * the local entry to other port
244 struct net_bridge_port
*op
;
245 list_for_each_entry(op
, &br
->port_list
, list
) {
247 ether_addr_equal(op
->dev
->dev_addr
,
259 spin_unlock_bh(&br
->hash_lock
);
262 /* No locking or refcounting, assumes caller has rcu_read_lock */
263 struct net_bridge_fdb_entry
*__br_fdb_get(struct net_bridge
*br
,
264 const unsigned char *addr
,
267 struct net_bridge_fdb_entry
*fdb
;
269 hlist_for_each_entry_rcu(fdb
,
270 &br
->hash
[br_mac_hash(addr
, vid
)], hlist
) {
271 if (ether_addr_equal(fdb
->addr
.addr
, addr
) &&
272 fdb
->vlan_id
== vid
) {
273 if (unlikely(has_expired(br
, fdb
)))
282 #if IS_ENABLED(CONFIG_ATM_LANE)
283 /* Interface used by ATM LANE hook to test
284 * if an addr is on some other bridge port */
285 int br_fdb_test_addr(struct net_device
*dev
, unsigned char *addr
)
287 struct net_bridge_fdb_entry
*fdb
;
288 struct net_bridge_port
*port
;
292 port
= br_port_get_rcu(dev
);
296 fdb
= __br_fdb_get(port
->br
, addr
, 0);
297 ret
= fdb
&& fdb
->dst
&& fdb
->dst
->dev
!= dev
&&
298 fdb
->dst
->state
== BR_STATE_FORWARDING
;
304 #endif /* CONFIG_ATM_LANE */
307 * Fill buffer with forwarding table records in
310 int br_fdb_fillbuf(struct net_bridge
*br
, void *buf
,
311 unsigned long maxnum
, unsigned long skip
)
313 struct __fdb_entry
*fe
= buf
;
315 struct net_bridge_fdb_entry
*f
;
317 memset(buf
, 0, maxnum
*sizeof(struct __fdb_entry
));
320 for (i
= 0; i
< BR_HASH_SIZE
; i
++) {
321 hlist_for_each_entry_rcu(f
, &br
->hash
[i
], hlist
) {
325 if (has_expired(br
, f
))
328 /* ignore pseudo entry for local MAC address */
337 /* convert from internal format to API */
338 memcpy(fe
->mac_addr
, f
->addr
.addr
, ETH_ALEN
);
340 /* due to ABI compat need to split into hi/lo */
341 fe
->port_no
= f
->dst
->port_no
;
342 fe
->port_hi
= f
->dst
->port_no
>> 8;
344 fe
->is_local
= f
->is_local
;
346 fe
->ageing_timer_value
= jiffies_delta_to_clock_t(jiffies
- f
->updated
);
358 static struct net_bridge_fdb_entry
*fdb_find(struct hlist_head
*head
,
359 const unsigned char *addr
,
362 struct net_bridge_fdb_entry
*fdb
;
364 hlist_for_each_entry(fdb
, head
, hlist
) {
365 if (ether_addr_equal(fdb
->addr
.addr
, addr
) &&
372 static struct net_bridge_fdb_entry
*fdb_find_rcu(struct hlist_head
*head
,
373 const unsigned char *addr
,
376 struct net_bridge_fdb_entry
*fdb
;
378 hlist_for_each_entry_rcu(fdb
, head
, hlist
) {
379 if (ether_addr_equal(fdb
->addr
.addr
, addr
) &&
386 static struct net_bridge_fdb_entry
*fdb_create(struct hlist_head
*head
,
387 struct net_bridge_port
*source
,
388 const unsigned char *addr
,
391 struct net_bridge_fdb_entry
*fdb
;
393 fdb
= kmem_cache_alloc(br_fdb_cache
, GFP_ATOMIC
);
395 memcpy(fdb
->addr
.addr
, addr
, ETH_ALEN
);
400 fdb
->updated
= fdb
->used
= jiffies
;
401 hlist_add_head_rcu(&fdb
->hlist
, head
);
406 static int fdb_insert(struct net_bridge
*br
, struct net_bridge_port
*source
,
407 const unsigned char *addr
, u16 vid
)
409 struct hlist_head
*head
= &br
->hash
[br_mac_hash(addr
, vid
)];
410 struct net_bridge_fdb_entry
*fdb
;
412 if (!is_valid_ether_addr(addr
))
415 fdb
= fdb_find(head
, addr
, vid
);
417 /* it is okay to have multiple ports with same
418 * address, just use the first one.
422 br_warn(br
, "adding interface %s with same address "
423 "as a received packet\n",
424 source
? source
->dev
->name
: br
->dev
->name
);
428 fdb
= fdb_create(head
, source
, addr
, vid
);
432 fdb
->is_local
= fdb
->is_static
= 1;
433 fdb_notify(br
, fdb
, RTM_NEWNEIGH
);
437 /* Add entry for local address of interface */
438 int br_fdb_insert(struct net_bridge
*br
, struct net_bridge_port
*source
,
439 const unsigned char *addr
, u16 vid
)
443 spin_lock_bh(&br
->hash_lock
);
444 ret
= fdb_insert(br
, source
, addr
, vid
);
445 spin_unlock_bh(&br
->hash_lock
);
449 void br_fdb_update(struct net_bridge
*br
, struct net_bridge_port
*source
,
450 const unsigned char *addr
, u16 vid
)
452 struct hlist_head
*head
= &br
->hash
[br_mac_hash(addr
, vid
)];
453 struct net_bridge_fdb_entry
*fdb
;
455 /* some users want to always flood. */
456 if (hold_time(br
) == 0)
459 /* ignore packets unless we are using this port */
460 if (!(source
->state
== BR_STATE_LEARNING
||
461 source
->state
== BR_STATE_FORWARDING
))
464 fdb
= fdb_find_rcu(head
, addr
, vid
);
466 /* attempt to update an entry for a local interface */
467 if (unlikely(fdb
->is_local
)) {
469 br_warn(br
, "received packet on %s with "
470 "own address as source address\n",
473 /* fastpath: update of existing entry */
475 fdb
->updated
= jiffies
;
478 spin_lock(&br
->hash_lock
);
479 if (likely(!fdb_find(head
, addr
, vid
))) {
480 fdb
= fdb_create(head
, source
, addr
, vid
);
482 fdb_notify(br
, fdb
, RTM_NEWNEIGH
);
484 /* else we lose race and someone else inserts
485 * it first, don't bother updating
487 spin_unlock(&br
->hash_lock
);
491 static int fdb_to_nud(const struct net_bridge_fdb_entry
*fdb
)
494 return NUD_PERMANENT
;
495 else if (fdb
->is_static
)
497 else if (has_expired(fdb
->dst
->br
, fdb
))
500 return NUD_REACHABLE
;
503 static int fdb_fill_info(struct sk_buff
*skb
, const struct net_bridge
*br
,
504 const struct net_bridge_fdb_entry
*fdb
,
505 u32 portid
, u32 seq
, int type
, unsigned int flags
)
507 unsigned long now
= jiffies
;
508 struct nda_cacheinfo ci
;
509 struct nlmsghdr
*nlh
;
512 nlh
= nlmsg_put(skb
, portid
, seq
, type
, sizeof(*ndm
), flags
);
516 ndm
= nlmsg_data(nlh
);
517 ndm
->ndm_family
= AF_BRIDGE
;
522 ndm
->ndm_ifindex
= fdb
->dst
? fdb
->dst
->dev
->ifindex
: br
->dev
->ifindex
;
523 ndm
->ndm_state
= fdb_to_nud(fdb
);
525 if (nla_put(skb
, NDA_LLADDR
, ETH_ALEN
, &fdb
->addr
))
526 goto nla_put_failure
;
527 ci
.ndm_used
= jiffies_to_clock_t(now
- fdb
->used
);
528 ci
.ndm_confirmed
= 0;
529 ci
.ndm_updated
= jiffies_to_clock_t(now
- fdb
->updated
);
531 if (nla_put(skb
, NDA_CACHEINFO
, sizeof(ci
), &ci
))
532 goto nla_put_failure
;
534 if (nla_put(skb
, NDA_VLAN
, sizeof(u16
), &fdb
->vlan_id
))
535 goto nla_put_failure
;
537 return nlmsg_end(skb
, nlh
);
540 nlmsg_cancel(skb
, nlh
);
544 static inline size_t fdb_nlmsg_size(void)
546 return NLMSG_ALIGN(sizeof(struct ndmsg
))
547 + nla_total_size(ETH_ALEN
) /* NDA_LLADDR */
548 + nla_total_size(sizeof(u16
)) /* NDA_VLAN */
549 + nla_total_size(sizeof(struct nda_cacheinfo
));
552 static void fdb_notify(struct net_bridge
*br
,
553 const struct net_bridge_fdb_entry
*fdb
, int type
)
555 struct net
*net
= dev_net(br
->dev
);
559 skb
= nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC
);
563 err
= fdb_fill_info(skb
, br
, fdb
, 0, 0, type
, 0);
565 /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
566 WARN_ON(err
== -EMSGSIZE
);
570 rtnl_notify(skb
, net
, 0, RTNLGRP_NEIGH
, NULL
, GFP_ATOMIC
);
574 rtnl_set_sk_err(net
, RTNLGRP_NEIGH
, err
);
577 /* Dump information about entries, in response to GETNEIGH */
578 int br_fdb_dump(struct sk_buff
*skb
,
579 struct netlink_callback
*cb
,
580 struct net_device
*dev
,
583 struct net_bridge
*br
= netdev_priv(dev
);
586 if (!(dev
->priv_flags
& IFF_EBRIDGE
))
589 for (i
= 0; i
< BR_HASH_SIZE
; i
++) {
590 struct net_bridge_fdb_entry
*f
;
592 hlist_for_each_entry_rcu(f
, &br
->hash
[i
], hlist
) {
593 if (idx
< cb
->args
[0])
596 if (fdb_fill_info(skb
, br
, f
,
597 NETLINK_CB(cb
->skb
).portid
,
611 /* Update (create or replace) forwarding database entry */
612 static int fdb_add_entry(struct net_bridge_port
*source
, const __u8
*addr
,
613 __u16 state
, __u16 flags
, __u16 vid
)
615 struct net_bridge
*br
= source
->br
;
616 struct hlist_head
*head
= &br
->hash
[br_mac_hash(addr
, vid
)];
617 struct net_bridge_fdb_entry
*fdb
;
618 bool modified
= false;
620 fdb
= fdb_find(head
, addr
, vid
);
622 if (!(flags
& NLM_F_CREATE
))
625 fdb
= fdb_create(head
, source
, addr
, vid
);
631 if (flags
& NLM_F_EXCL
)
634 if (fdb
->dst
!= source
) {
640 if (fdb_to_nud(fdb
) != state
) {
641 if (state
& NUD_PERMANENT
)
642 fdb
->is_local
= fdb
->is_static
= 1;
643 else if (state
& NUD_NOARP
) {
647 fdb
->is_local
= fdb
->is_static
= 0;
654 fdb
->updated
= jiffies
;
655 fdb_notify(br
, fdb
, RTM_NEWNEIGH
);
661 static int __br_fdb_add(struct ndmsg
*ndm
, struct net_bridge_port
*p
,
662 const unsigned char *addr
, u16 nlh_flags
, u16 vid
)
666 if (ndm
->ndm_flags
& NTF_USE
) {
668 br_fdb_update(p
->br
, p
, addr
, vid
);
671 spin_lock_bh(&p
->br
->hash_lock
);
672 err
= fdb_add_entry(p
, addr
, ndm
->ndm_state
,
674 spin_unlock_bh(&p
->br
->hash_lock
);
680 /* Add new permanent fdb entry with RTM_NEWNEIGH */
681 int br_fdb_add(struct ndmsg
*ndm
, struct nlattr
*tb
[],
682 struct net_device
*dev
,
683 const unsigned char *addr
, u16 nlh_flags
)
685 struct net_bridge_port
*p
;
687 struct net_port_vlans
*pv
;
688 unsigned short vid
= VLAN_N_VID
;
690 if (!(ndm
->ndm_state
& (NUD_PERMANENT
|NUD_NOARP
|NUD_REACHABLE
))) {
691 pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm
->ndm_state
);
696 if (nla_len(tb
[NDA_VLAN
]) != sizeof(unsigned short)) {
697 pr_info("bridge: RTM_NEWNEIGH with invalid vlan\n");
701 vid
= nla_get_u16(tb
[NDA_VLAN
]);
703 if (vid
>= VLAN_N_VID
) {
704 pr_info("bridge: RTM_NEWNEIGH with invalid vlan id %d\n",
710 p
= br_port_get_rtnl(dev
);
712 pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
717 pv
= nbp_get_vlan_info(p
);
718 if (vid
!= VLAN_N_VID
) {
719 if (!pv
|| !test_bit(vid
, pv
->vlan_bitmap
)) {
720 pr_info("bridge: RTM_NEWNEIGH with unconfigured "
721 "vlan %d on port %s\n", vid
, dev
->name
);
725 /* VID was specified, so use it. */
726 err
= __br_fdb_add(ndm
, p
, addr
, nlh_flags
, vid
);
728 if (!pv
|| bitmap_empty(pv
->vlan_bitmap
, BR_VLAN_BITMAP_LEN
)) {
729 err
= __br_fdb_add(ndm
, p
, addr
, nlh_flags
, 0);
733 /* We have vlans configured on this port and user didn't
734 * specify a VLAN. To be nice, add/update entry for every
737 for_each_set_bit(vid
, pv
->vlan_bitmap
, BR_VLAN_BITMAP_LEN
) {
738 err
= __br_fdb_add(ndm
, p
, addr
, nlh_flags
, vid
);
748 int fdb_delete_by_addr(struct net_bridge
*br
, const u8
*addr
,
751 struct hlist_head
*head
= &br
->hash
[br_mac_hash(addr
, vlan
)];
752 struct net_bridge_fdb_entry
*fdb
;
754 fdb
= fdb_find(head
, addr
, vlan
);
762 static int __br_fdb_delete(struct net_bridge_port
*p
,
763 const unsigned char *addr
, u16 vid
)
767 spin_lock_bh(&p
->br
->hash_lock
);
768 err
= fdb_delete_by_addr(p
->br
, addr
, vid
);
769 spin_unlock_bh(&p
->br
->hash_lock
);
774 /* Remove neighbor entry with RTM_DELNEIGH */
775 int br_fdb_delete(struct ndmsg
*ndm
, struct nlattr
*tb
[],
776 struct net_device
*dev
,
777 const unsigned char *addr
)
779 struct net_bridge_port
*p
;
781 struct net_port_vlans
*pv
;
782 unsigned short vid
= VLAN_N_VID
;
785 if (nla_len(tb
[NDA_VLAN
]) != sizeof(unsigned short)) {
786 pr_info("bridge: RTM_NEWNEIGH with invalid vlan\n");
790 vid
= nla_get_u16(tb
[NDA_VLAN
]);
792 if (vid
>= VLAN_N_VID
) {
793 pr_info("bridge: RTM_NEWNEIGH with invalid vlan id %d\n",
798 p
= br_port_get_rtnl(dev
);
800 pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
805 pv
= nbp_get_vlan_info(p
);
806 if (vid
!= VLAN_N_VID
) {
807 if (!pv
|| !test_bit(vid
, pv
->vlan_bitmap
)) {
808 pr_info("bridge: RTM_DELNEIGH with unconfigured "
809 "vlan %d on port %s\n", vid
, dev
->name
);
813 err
= __br_fdb_delete(p
, addr
, vid
);
815 if (!pv
|| bitmap_empty(pv
->vlan_bitmap
, BR_VLAN_BITMAP_LEN
)) {
816 err
= __br_fdb_delete(p
, addr
, 0);
820 /* We have vlans configured on this port and user didn't
821 * specify a VLAN. To be nice, add/update entry for every
825 for_each_set_bit(vid
, pv
->vlan_bitmap
, BR_VLAN_BITMAP_LEN
) {
826 err
&= __br_fdb_delete(p
, addr
, vid
);