neigh: Better handling of transition to NUD_PROBE state
authorErik Kline <ek@google.com>
Wed, 2 Dec 2015 10:01:20 +0000 (15:01 +0530)
committermobile promotions <svcmobile_promotions@nvidia.com>
Wed, 2 Dec 2015 22:09:43 +0000 (14:09 -0800)
commitbf34ba6c9ed96b4926b1ab5136ce9c894df68c3f
tree3dd5931624883948b264eb830304f36eb2d379bc
parent4b26f8f182a7501e7307d3cff11e77acbdd970d8
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).

Bug 200154120

Change-Id: I3ee05ab3489173824d38a4b3790bcf0840e0dc40
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>
Signed-off-by: kraghavender <kraghavender@nvidia.com>
Reviewed-on: http://git-master/r/840346
Reviewed-by: Narayan Reddy <narayanr@nvidia.com>
Reviewed-by: Om Prakash Singh <omp@nvidia.com>
Tested-by: Om Prakash Singh <omp@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Ashutosh Jha <ajha@nvidia.com>
net/core/neighbour.c