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authorToshiaki Makita <makita.toshiaki@lab.ntt.co.jp>2014-02-07 16:48:22 +0900
committerDavid S. Miller <davem@davemloft.net>2014-02-10 14:34:33 -0800
commit2b292fb4a57dc233e298a84196d33be0bc3828e4 (patch)
tree3ed6f64d59ea5a91e8524bdc87ffb23823a08a26 /net
parenta4b816d8ba1c1917842dc3de97cbf8ef116e043e (diff)
downloadlinux-stericsson-2b292fb4a57dc233e298a84196d33be0bc3828e4.tar.gz
bridge: Fix the way to check if a local fdb entry can be deleted
We should take into account the followings when deleting a local fdb entry. - nbp_vlan_find() can be used only when vid != 0 to check if an entry is deletable, because a fdb entry with vid 0 can exist at any time while nbp_vlan_find() always return false with vid 0. Example of problematic case: ip link set eth0 address 12:34:56:78:90:ab ip link set eth1 address 12:34:56:78:90:ab brctl addif br0 eth0 brctl addif br0 eth1 ip link set eth0 address aa:bb:cc:dd:ee:ff Then, the fdb entry 12:34:56:78:90:ab will be deleted even though the bridge port eth1 still has that address. - The port to which the bridge device is attached might needs a local entry if its mac address is set manually. Example of problematic case: ip link set eth0 address 12:34:56:78:90:ab brctl addif br0 eth0 ip link set br0 address 12:34:56:78:90:ab ip link set eth0 address aa:bb:cc:dd:ee:ff Then, the fdb still must have the entry 12:34:56:78:90:ab, but it will be deleted. We can use br->dev->addr_assign_type to check if the address is manually set or not, but I propose another approach. Since we delete and insert local entries whenever changing mac address of the bridge device, we can change dst of the entry to NULL regardless of addr_assign_type when deleting an entry associated with a certain port, and if it is found to be unnecessary later, then delete it. That is, if changing mac address of a port, the entry might be changed to its dst being NULL first, but is eventually deleted when recalculating and changing bridge id. This approach is especially useful when we want to share the code with deleting vlan in which the bridge device might want such an entry regardless of addr_assign_type, and makes things easy because we don't have to consider if mac address of the bridge device will be changed or not at the time we delete a local entry of a port, which means fdb code will not be bothered even if the bridge id calculating logic is changed in the future. Also, this change reduces inconsistent state, where frames whose dst is the mac address of the bridge, can't reach the bridge because of premature fdb entry deletion. This change reduces the possibility that the bridge device replies unreachable mac address to arp requests, which could occur during the short window between calling del_nbp() and br_stp_recalculate_bridge_id() in br_del_if(). This will effective after br_fdb_delete_by_port() starts to use the same code by following patch. 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>
Diffstat (limited to 'net')
-rw-r--r--net/bridge/br_fdb.c10
-rw-r--r--net/bridge/br_private.h6
-rw-r--r--net/bridge/br_vlan.c19
3 files changed, 34 insertions, 1 deletions
diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index 96ab1d1748d0..b4005f5b28f4 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -114,12 +114,20 @@ void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
if (op != p &&
ether_addr_equal(op->dev->dev_addr,
f->addr.addr) &&
- nbp_vlan_find(op, vid)) {
+ (!vid || nbp_vlan_find(op, vid))) {
f->dst = op;
goto skip_delete;
}
}
+ /* maybe bridge device has same hw addr? */
+ if (ether_addr_equal(br->dev->dev_addr,
+ f->addr.addr) &&
+ (!vid || br_vlan_find(br, vid))) {
+ f->dst = NULL;
+ goto skip_delete;
+ }
+
/* delete old one */
fdb_delete(br, f);
skip_delete:
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 939a59e15036..f91e1d9c8e92 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -585,6 +585,7 @@ struct sk_buff *br_handle_vlan(struct net_bridge *br,
int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags);
int br_vlan_delete(struct net_bridge *br, u16 vid);
void br_vlan_flush(struct net_bridge *br);
+bool br_vlan_find(struct net_bridge *br, u16 vid);
int br_vlan_filter_toggle(struct net_bridge *br, unsigned long val);
int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags);
int nbp_vlan_delete(struct net_bridge_port *port, u16 vid);
@@ -666,6 +667,11 @@ static inline void br_vlan_flush(struct net_bridge *br)
{
}
+static inline bool br_vlan_find(struct net_bridge *br, u16 vid)
+{
+ return false;
+}
+
static inline int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags)
{
return -EOPNOTSUPP;
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 4ca4d0a0151c..233ec1c6e9db 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -295,6 +295,25 @@ void br_vlan_flush(struct net_bridge *br)
__vlan_flush(pv);
}
+bool br_vlan_find(struct net_bridge *br, u16 vid)
+{
+ struct net_port_vlans *pv;
+ bool found = false;
+
+ rcu_read_lock();
+ pv = rcu_dereference(br->vlan_info);
+
+ if (!pv)
+ goto out;
+
+ if (test_bit(vid, pv->vlan_bitmap))
+ found = true;
+
+out:
+ rcu_read_unlock();
+ return found;
+}
+
int br_vlan_filter_toggle(struct net_bridge *br, unsigned long val)
{
if (!rtnl_trylock())