From 36393395536064e483b73d173f6afc103eadfbc4 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Thu, 14 Jun 2012 22:21:46 -0700 Subject: ipv4: Handle PMTU in all ICMP error handlers. With ip_rt_frag_needed() removed, we have to explicitly update PMTU information in every ICMP error handler. Create two helper functions to facilitate this. 1) ipv4_sk_update_pmtu() This updates the PMTU when we have a socket context to work with. 2) ipv4_update_pmtu() Raw version, used when no socket context is available. For this interface, we essentially just pass in explicit arguments for the flow identity information we would have extracted from the socket. And you'll notice that ipv4_sk_update_pmtu() is simply implemented in terms of ipv4_update_pmtu() Note that __ip_route_output_key() is used, rather than something like ip_route_output_flow() or ip_route_output_key(). This is because we absolutely do not want to end up with a route that does IPSEC encapsulation and the like. Instead, we only want the route that would get us to the node described by the outermost IP header. Reported-by: Steffen Klassert Signed-off-by: David S. Miller --- net/ipv4/ip_gre.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'net/ipv4/ip_gre.c') diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index f49047b79609..594cec35ac4d 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -516,9 +516,6 @@ static void ipgre_err(struct sk_buff *skb, u32 info) case ICMP_PORT_UNREACH: /* Impossible event. */ return; - case ICMP_FRAG_NEEDED: - /* Soft state for pmtu is maintained by IP core. */ - return; default: /* All others are translated to HOST_UNREACH. rfc2003 contains "deep thoughts" about NET_UNREACH, @@ -538,7 +535,16 @@ static void ipgre_err(struct sk_buff *skb, u32 info) flags & GRE_KEY ? *(((__be32 *)p) + (grehlen / 4) - 1) : 0, p[1]); - if (t == NULL || t->parms.iph.daddr == 0 || + if (t == NULL) + goto out; + + if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { + ipv4_update_pmtu(skb, dev_net(skb->dev), info, + t->parms.link, 0, IPPROTO_GRE, 0); + goto out; + } + + if (t->parms.iph.daddr == 0 || ipv4_is_multicast(t->parms.iph.daddr)) goto out; -- cgit v1.2.3