Commit 653437d0 authored Apr 28, 2015 by Martin KaFai Lau Committed by David S. Miller May 01, 2015

ipv6: Stop /128 route from disappearing after pmtu update



This patch is mostly from Steffen Klassert <steffen.klassert@secunet.com>.
I only removed the (rt6->rt6i_dst.plen == 128) check from
ip6_rt_update_pmtu() because the (rt6->rt6i_flags & RTF_CACHE) test
has already implied it.

This patch:
1. Create RTF_CACHE route for /128 non local route
2. After (1), all routes that allow pmtu update should have a RTF_CACHE
   clone.  Hence, stop updating MTU for any non RTF_CACHE route.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 9fbdcfaf

net/ipv6/route.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -977,7 +977,7 @@ redo_rt6_select:

		if (!(rt->rt6i_flags & (RTF_NONEXTHOP \| RTF_GATEWAY)))
		nrt = rt6_alloc_cow(rt, &fl6->daddr, &fl6->saddr);
		else if (!(rt->dst.flags & DST_HOST))
		else if (!(rt->dst.flags & DST_HOST) \|\| !(rt->dst.flags & RTF_LOCAL))
		nrt = rt6_alloc_clone(rt, &fl6->daddr);
		else
		goto out2;
		@@ -1172,7 +1172,7 @@ static void ip6_rt_update_pmtu(struct dst_entry dst, struct sock sk,
		struct rt6_info rt6 = (struct rt6_info )dst;

		dst_confirm(dst);
		if (mtu < dst_mtu(dst) && rt6->rt6i_dst.plen == 128) {
		if (mtu < dst_mtu(dst) && (rt6->rt6i_flags & RTF_CACHE)) {
		struct net *net = dev_net(dst->dev);

		rt6->rt6i_flags \|= RTF_MODIFIED;

Admin message