From 653437d02f1f12d528c290e64f6dc54be1224db2 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Tue, 28 Apr 2015 13:03:05 -0700 Subject: [PATCH] ipv6: Stop /128 route from disappearing after pmtu update This patch is mostly from Steffen Klassert . 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 Signed-off-by: Steffen Klassert Reviewed-by: Hannes Frederic Sowa Signed-off-by: David S. Miller --- net/ipv6/route.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 07562a2702c9..aa4cfdd13f28 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -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; -- 2.20.1