net: bridge: Fix improper taking over HW learned FDB

Commit 7e26bf4 ("net: bridge: allow SW learn to take over HW fdb entries") added the ability to "take over an entry which was previously learned via HW when it shows up from a SW port". However, if an entry was learned via HW and then a control packet (e.g., ARP request) was trapped to the CPU, the bridge driver will update the entry and remove the externally learned flag, although the entry is still present in HW. Instead, only clear the externally learned flag in case of roaming. Fixes: 7e26bf4 ("net: bridge: allow SW learn to take over HW fdb entries") Signed-off-by: Ido Schimmel <[email protected]> Signed-off-by: Arkadi Sharashevsky <[email protected]> Cc: Nikolay Aleksandrov <[email protected]> Acked-by: Nikolay Aleksandrov <[email protected]> Signed-off-by: David S. Miller <[email protected]>
soumdtt · May 1, 2017 · 58073b3 · 58073b3
1 parent ba3f571
commit 58073b3
Showing 1 changed file with 3 additions and 5 deletions.
diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
@@ -589,16 +589,14 @@ void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
 			if (unlikely(source != fdb->dst)) {
 				fdb->dst = source;
 				fdb_modified = true;
+				/* Take over HW learned entry */
+				if (unlikely(fdb->added_by_external_learn))
+					fdb->added_by_external_learn = 0;
 			}
 			if (now != fdb->updated)
 				fdb->updated = now;
 			if (unlikely(added_by_user))
 				fdb->added_by_user = 1;
-			/* Take over HW learned entry */
-			if (unlikely(fdb->added_by_external_learn)) {
-				fdb->added_by_external_learn = 0;
-				fdb_modified = true;
-			}
 			if (unlikely(fdb_modified))
 				fdb_notify(br, fdb, RTM_NEWNEIGH);
 		}