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 <avagin@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Andrey Vagin 2010-12-11 15:20:11 +00:00 committed by David S. Miller
parent af3e5bd5f6
commit d3052b557a
1 changed files with 6 additions and 1 deletions
net/ipv6

View File

@ -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;