[PATCH 56/81] ipv6: do not create neighbor entries for local delivery

[Herton Ronaldo Krzesinski]

3.5.7.6 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Marcelo Ricardo Leitner <mleitner at redhat.com>

commit bd30e947207e2ea0ff2c08f5b4a03025ddce48d3 upstream.

They will be created at output, if ever needed. This avoids creating
empty neighbor entries when TPROXYing/Forwarding packets for addresses
that are not even directly reachable.

Note that IPv4 already handles it this way. No neighbor entries are
created for local input.

Tested by myself and customer.

Signed-off-by: Jiri Pirko <jiri at resnulli.us>
Signed-off-by: Marcelo Ricardo Leitner <mleitner at redhat.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
[ herton: adjust if condition, add additional RTF_LOCAL flag for the
  check ]
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
---
 net/ipv6/route.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index fd44184..08c149c 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -846,7 +846,8 @@ restart:
 	dst_hold(&rt->dst);
 	read_unlock_bh(&table->tb6_lock);
 
-	if (!dst_get_neighbour_noref_raw(&rt->dst) && !(rt->rt6i_flags & RTF_NONEXTHOP))
+	if (!dst_get_neighbour_noref_raw(&rt->dst) &&
+	    !(rt->rt6i_flags & (RTF_NONEXTHOP | RTF_LOCAL)))
 		nrt = rt6_alloc_cow(rt, &fl6->daddr, &fl6->saddr);
 	else if (!(rt->dst.flags & DST_HOST))
 		nrt = rt6_alloc_clone(rt, &fl6->daddr);
-- 
1.7.9.5