bridge: Fix the way to find old local fdb entries in br_fdb_changeaddr
br_fdb_changeaddr() assumes that there is at most one local entry per port
per vlan. It used to be true, but since commit 36fd2b63e3b4 ("bridge: allow
creating/deleting fdb entries via netlink"), it has not been so.
Therefore, the function might fail to search a correct previous address
to be deleted and delete an arbitrary local entry if user has added local
entries manually.
Example of problematic case:
ip link set eth0 address ee:ff:12:34:56:78
brctl addif br0 eth0
bridge fdb add 12:34:56:78:90:ab dev eth0 master
ip link set eth0 address aa:bb:cc:dd:ee:ff
Then, the address 12:34:56:78:90:ab might be deleted instead of
ee:ff:12:34:56:78, the original mac address of eth0.
Address this issue by introducing a new flag, added_by_user, to struct
net_bridge_fdb_entry.
Note that br_fdb_delete_by_port() has to set added_by_user to 0 in cases
like:
ip link set eth0 address 12:34:56:78:90:ab
ip link set eth1 address aa:bb:cc:dd:ee:ff
brctl addif br0 eth0
bridge fdb add aa:bb:cc:dd:ee:ff dev eth0 master
brctl addif br0 eth1
brctl delif br0 eth0
In this case, kernel should delete the user-added entry aa:bb:cc:dd:ee:ff,
but it also should have been added by "brctl addif br0 eth1" originally,
so we don't delete it and treat it a new kernel-created entry.
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index bf8dc7d..28d5446 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -77,7 +77,7 @@
/* insert into forwarding database after filtering to avoid spoofing */
br = p->br;
if (p->flags & BR_LEARNING)
- br_fdb_update(br, p, eth_hdr(skb)->h_source, vid);
+ br_fdb_update(br, p, eth_hdr(skb)->h_source, vid, false);
if (!is_broadcast_ether_addr(dest) && is_multicast_ether_addr(dest) &&
br_multicast_rcv(br, p, skb, vid))
@@ -148,7 +148,7 @@
br_vlan_get_tag(skb, &vid);
if (p->flags & BR_LEARNING)
- br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid);
+ br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, false);
return 0; /* process further */
}