bridge: Fix the way to insert new local fdb entries in br_fdb_changeaddr

Since commit bc9a25d21ef8 ("bridge: Add vlan support for local fdb entries"),
br_fdb_changeaddr() has inserted a new local fdb entry only if it can
find old one. But if we have two ports where they have the same address
or user has deleted a local entry, there will be no entry for one of the
ports.

Example of problematic case:
  ip link set eth0 address aa:bb:cc:dd:ee:ff
  ip link set eth1 address aa:bb:cc:dd:ee:ff
  brctl addif br0 eth0
  brctl addif br0 eth1 # eth1 will not have a local entry due to dup.
  ip link set eth1 address 12:34:56:78:90:ab
Then, the new entry for the address 12:34:56:78:90:ab will not be
created, and the bridge device will not be able to communicate.

Insert new entries regardless of whether we can find old entries or not.

Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 20 insertions, 9 deletions

diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index ce5411995a63..96ab1d1748d0 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -92,8 +92,10 @@ static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f)
 void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
 {
         struct net_bridge *br = p->br;
-        bool no_vlan = (nbp_get_vlan_info(p) == NULL) ? true : false;
+        struct net_port_vlans *pv = nbp_get_vlan_info(p);
+        bool no_vlan = !pv;
         int i;
+        u16 vid;
 
         spin_lock_bh(&br->hash_lock);
 
@@ -114,28 +116,37 @@ void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
                                                              f->addr.addr) &&
                                             nbp_vlan_find(op, vid)) {
                                                 f->dst = op;
-                                                goto insert;
+                                                goto skip_delete;
                                         }
                                 }
 
                                 /* delete old one */
                                 fdb_delete(br, f);
-insert:
-                                /* insert new address,  may fail if invalid
-                                 * address or dup.
-                                 */
-                                fdb_insert(br, p, newaddr, vid);
-
+skip_delete:
                                 /* if this port has no vlan information
                                  * configured, we can safely be done at
                                  * this point.
                                  */
                                 if (no_vlan)
-                                        goto done;
+                                        goto insert;
                         }
                 }
         }
 
+insert:
+        /* insert new address,  may fail if invalid address or dup. */
+        fdb_insert(br, p, newaddr, 0);
+
+        if (no_vlan)
+                goto done;
+
+        /* Now add entries for every VLAN configured on the port.
+         * This function runs under RTNL so the bitmap will not change
+         * from under us.
+         */
+        for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
+                fdb_insert(br, p, newaddr, vid);
+
 done:
         spin_unlock_bh(&br->hash_lock);
 }