[Bridge] [PATCH net-next v2] net: bridge: Fix improper taking over HW learned FDB

Arkadi Sharshevsky arkadis at mellanox.com
Fri Apr 28 16:31:38 UTC 2017


Commit 7e26bf45e4cb ("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: 7e26bf45e4cb ("net: bridge: allow SW learn to take over HW fdb entries")
Signed-off-by: Ido Schimmel <idosch at mellanox.com>
Signed-off-by: Arkadi Sharashevsky <arkadis at mellanox.com>
Cc: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
---
v1->v2
- net-next rebase.
---
 net/bridge/br_fdb.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index de7988b..5905eb7 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -589,16 +589,16 @@ 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;
+					fdb_modified = true;
+				}
 			}
 			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);
 		}
-- 
2.4.11



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