Update 'confirmed' timestamp when ARP packet is received. It shouldn't
affect locktime logic and anyway entry can be confirmed by any higher-layer
protocol. Thus it makes sense to confirm it when ARP packet is received.

Fixes: 77d7123342 ("neighbour: update neigh timestamps iff update is effective")
Signed-off-by: Vasily Khoruzhick <vasil...@arista.com>
---
v2: - update comment to match new code.
v3: - fix wording in commit message, make 'Fixes' tag one line, remove extra 
new line
      between 'Fixes' and 'Signed-off-by'.

 net/core/neighbour.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index aa19d86937af..91592fceeaad 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1180,6 +1180,12 @@ int neigh_update(struct neighbour *neigh, const u8 
*lladdr, u8 new,
                lladdr = neigh->ha;
        }
 
+       /* Update confirmed timestamp for neighbour entry after we
+        * received ARP packet even if it doesn't change IP to MAC binding.
+        */
+       if (new & NUD_CONNECTED)
+               neigh->confirmed = jiffies;
+
        /* If entry was valid and address is not changed,
           do not change entry state, if new one is STALE.
         */
@@ -1201,15 +1207,12 @@ int neigh_update(struct neighbour *neigh, const u8 
*lladdr, u8 new,
                }
        }
 
-       /* Update timestamps only once we know we will make a change to the
+       /* Update timestamp only once we know we will make a change to the
         * neighbour entry. Otherwise we risk to move the locktime window with
         * noop updates and ignore relevant ARP updates.
         */
-       if (new != old || lladdr != neigh->ha) {
-               if (new & NUD_CONNECTED)
-                       neigh->confirmed = jiffies;
+       if (new != old || lladdr != neigh->ha)
                neigh->updated = jiffies;
-       }
 
        if (new != old) {
                neigh_del_timer(neigh);
-- 
2.18.0

Reply via email to