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authorErik Kline <ek@google.com>2015-05-18 13:44:41 +0300
committerDavid S. Miller <davem@davemloft.net>2015-05-21 23:52:17 +0300
commit765c9c639fbb132af0cafc6e1da22fe6cea26bb8 (patch)
tree3a197a9708a23ffafcee827225366c8f3ecbbe49 /net
parent06b2c61c92a9942769ee8da22d3ce8b8b935c038 (diff)
downloadlinux-765c9c639fbb132af0cafc6e1da22fe6cea26bb8.tar.xz
neigh: Better handling of transition to NUD_PROBE state
[1] When entering NUD_PROBE state via neigh_update(), perhaps received from userspace, correctly (re)initialize the probes count to zero. This is useful for forcing revalidation of a neighbor (for example if the host is attempting to do DNA [IPv4 4436, IPv6 6059]). [2] Notify listeners when a neighbor goes into NUD_PROBE state. By sending notifications on entry to NUD_PROBE state listeners get more timely warnings of imminent connectivity issues. The current notifications on entry to NUD_STALE have somewhat limited usefulness: NUD_STALE is a perfectly normal state, as is NUD_DELAY, whereas notifications on entry to NUD_FAILURE come after a neighbor reachability problem has been confirmed (typically after three probes). Signed-off-by: Erik Kline <ek@google.com> Acked-By: Lorenzo Colitti <lorenzo@google.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/core/neighbour.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 3de654256028..3a74df750af4 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -913,6 +913,7 @@ static void neigh_timer_handler(unsigned long arg)
neigh->nud_state = NUD_PROBE;
neigh->updated = jiffies;
atomic_set(&neigh->probes, 0);
+ notify = 1;
next = now + NEIGH_VAR(neigh->parms, RETRANS_TIME);
}
} else {
@@ -1144,6 +1145,8 @@ int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
if (new != old) {
neigh_del_timer(neigh);
+ if (new & NUD_PROBE)
+ atomic_set(&neigh->probes, 0);
if (new & NUD_IN_TIMER)
neigh_add_timer(neigh, (jiffies +
((new & NUD_REACHABLE) ?