From d3052b557a1c94c21f50465702fa886753ce6b43 Mon Sep 17 00:00:00 2001 From: Andrey Vagin Date: Sat, 11 Dec 2010 15:20:11 +0000 Subject: [PATCH] ipv6: delete expired route in ip6_pmtu_deliver The first big packets sent to a "low-MTU" client correctly triggers the creation of a temporary route containing the reduced MTU. But after the temporary route has expired, new ICMP6 "packet too big" will be sent, rt6_pmtu_discovery will find the previous EXPIRED route check that its mtu isn't bigger then in icmp packet and do nothing before the temporary route will not deleted by gc. I make the simple experiment: while :; do time ( dd if=/dev/zero bs=10K count=1 | ssh hostname dd of=/dev/null ) || break; done The "time" reports real 0m0.197s if a temporary route isn't expired, but it reports real 0m52.837s (!!!!) immediately after a temporare route has expired. Signed-off-by: Andrey Vagin Signed-off-by: David S. Miller --- net/ipv6/route.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 96455ffb76fb..7659d6f16e6b 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1565,11 +1565,16 @@ static void rt6_do_pmtu_disc(struct in6_addr *daddr, struct in6_addr *saddr, { struct rt6_info *rt, *nrt; int allfrag = 0; - +again: rt = rt6_lookup(net, daddr, saddr, ifindex, 0); if (rt == NULL) return; + if (rt6_check_expired(rt)) { + ip6_del_rt(rt); + goto again; + } + if (pmtu >= dst_mtu(&rt->dst)) goto out; -- 2.20.1