[PATCH] IPv6: fix rt_lookup in pmtu_discovery

[Tom Herbert <therbert@google.com>]

In rt6_pmtu_discovery a route lookup is done constrained to the
receiving interface of the ICMP message.  In the case of an asymmetric
routing, the receive interface may be different than the sending
interface, so no route will be found in such cases and pmtu is never
correctly set in the route to the destination.  This patch fixes that
by not using the receive interface in the lookup.

Tom

Signed-off-by: Tom Herbert <therbert@google.com>

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index df9432a..d7d8893 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1569,7 +1569,7 @@ void rt6_pmtu_discovery(struct in6_addr *daddr,
struct in6_addr *saddr,
        struct net *net = dev_net(dev);
        int allfrag = 0;

-       rt = rt6_lookup(net, daddr, saddr, dev->ifindex, 0);
+       rt = rt6_lookup(net, daddr, saddr, 0, 0);
        if (rt == NULL)
                return;