From: Bob Gilligan <gilligan@aristanetworks.com>
Date: Sun, 15 Dec 2013 21:39:56 +0000 (-0800)
Subject: neigh: Netlink notification for administrative NUD state change
X-Git-Tag: submit/tizen/20160607.132125~5444^2~3
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=53385d2d1de84f4036a0919ec46964c4e81b83f5;p=sdk%2Femulator%2Femulator-kernel.git

neigh: Netlink notification for administrative NUD state change

The neighbour code sends up an RTM_NEWNEIGH netlink notification if
the NUD state of a neighbour cache entry is changed by a timer (e.g.
from REACHABLE to STALE), even if the lladdr of the entry has not
changed.

But an administrative change to the the NUD state of a neighbour cache
entry that does not change the lladdr (e.g. via "ip -4 neigh change
...  nud ...") does not trigger a netlink notification.  This means
that netlink listeners will not hear about administrative NUD state
changes such as from a resolved state to PERMANENT.

This patch changes the neighbor code to generate an RTM_NEWNEIGH
message when the NUD state of an entry is changed administratively.

Signed-off-by: Bob Gilligan <gilligan@aristanetworks.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index ca15f32..36b1443 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1161,6 +1161,7 @@ int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
 						 neigh->parms->reachable_time :
 						 0)));
 		neigh->nud_state = new;
+		notify = 1;
 	}
 
 	if (lladdr != neigh->ha) {