ddd4aa424b
Validity of the cached PMTU information is indicated by it's expiration value being non-zero, just as per dst->expires. The scheme we will use is that we will remember the pre-ICMP value held in the metrics or route entry, and then at expiration time we will restore that value. In this way PMTU expiration does not kill off the cached route as is done currently. Redirect information is permanent, or at least until another redirect is received. Signed-off-by: David S. Miller <davem@davemloft.net>