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authorMaciej Żenczykowski <maze@google.com>2010-10-03 14:49:00 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2010-12-09 13:24:19 -0800
commit7c873a37d10ef7e9291b812421d7e6ef52f4793a (patch)
tree7381c8124bff8faec0733c166abaf3b26b2360be
parent1d58c9a17dc76d4ae75e9f63417be0e6de48bb48 (diff)
downloadlwn-7c873a37d10ef7e9291b812421d7e6ef52f4793a.tar.gz
lwn-7c873a37d10ef7e9291b812421d7e6ef52f4793a.zip
net: Fix IPv6 PMTU disc. w/ asymmetric routes
[ Upstream commit ae878ae280bea286ff2b1e1cb6e609dd8cb4501d ] Signed-off-by: Maciej Żenczykowski <maze@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--net/ipv6/route.c28
1 files changed, 24 insertions, 4 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 63442a1e741c..bb7cc04e5c4f 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1507,14 +1507,13 @@ out:
* i.e. Path MTU discovery
*/
-void rt6_pmtu_discovery(struct in6_addr *daddr, struct in6_addr *saddr,
- struct net_device *dev, u32 pmtu)
+static void rt6_do_pmtu_disc(struct in6_addr *daddr, struct in6_addr *saddr,
+ struct net *net, u32 pmtu, int ifindex)
{
struct rt6_info *rt, *nrt;
- struct net *net = dev_net(dev);
int allfrag = 0;
- rt = rt6_lookup(net, daddr, saddr, dev->ifindex, 0);
+ rt = rt6_lookup(net, daddr, saddr, ifindex, 0);
if (rt == NULL)
return;
@@ -1582,6 +1581,27 @@ out:
dst_release(&rt->u.dst);
}
+void rt6_pmtu_discovery(struct in6_addr *daddr, struct in6_addr *saddr,
+ struct net_device *dev, u32 pmtu)
+{
+ struct net *net = dev_net(dev);
+
+ /*
+ * RFC 1981 states that a node "MUST reduce the size of the packets it
+ * is sending along the path" that caused the Packet Too Big message.
+ * Since it's not possible in the general case to determine which
+ * interface was used to send the original packet, we update the MTU
+ * on the interface that will be used to send future packets. We also
+ * update the MTU on the interface that received the Packet Too Big in
+ * case the original packet was forced out that interface with
+ * SO_BINDTODEVICE or similar. This is the next best thing to the
+ * correct behaviour, which would be to update the MTU on all
+ * interfaces.
+ */
+ rt6_do_pmtu_disc(daddr, saddr, net, pmtu, 0);
+ rt6_do_pmtu_disc(daddr, saddr, net, pmtu, dev->ifindex);
+}
+
/*
* Misc support functions
*/