sctp: Adjust PMTU updates to accomodate route invalidation.

This adjusts the call to dst_ops->update_pmtu() so that we can
transparently handle the fact that, in the future, the dst itself can
be invalidated by the PMTU update (when we have non-host routes cached
in sockets).

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 2 deletions

diff --git a/net/sctp/transport.c b/net/sctp/transport.c
index 1dcceb6e0ce..e69e1a2175a 100644
--- a/net/sctp/transport.c
+++ b/net/sctp/transport.c
@@ -228,7 +228,7 @@ void sctp_transport_pmtu(struct sctp_transport *transport, struct sock *sk)
                 transport->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
 }
 
-void sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu)
+void sctp_transport_update_pmtu(struct sock *sk, struct sctp_transport *t, u32 pmtu)
 {
         struct dst_entry *dst;
 
@@ -245,8 +245,16 @@ void sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu)
         }
 
         dst = sctp_transport_dst_check(t);
-        if (dst)
+        if (!dst)
+                t->af_specific->get_dst(t, &t->saddr, &t->fl, sk);
+
+        if (dst) {
                 dst->ops->update_pmtu(dst, pmtu);
+
+                dst = sctp_transport_dst_check(t);
+                if (!dst)
+                        t->af_specific->get_dst(t, &t->saddr, &t->fl, sk);
+        }
 }
 
 /* Caches the dst entry and source address for a transport's destination