sctp: introduce sctp_dst_mtu

Which makes sure that the MTU respects the minimum value of
SCTP_DEFAULT_MINSEGMENT and that it is correctly aligned.

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
index e327acad8e7d0710e30f32d0829116593c1171cf..4965cbfa7d92c0f60a76dd6e03571f78209dda5a 100644 (file)
--- a/include/net/sctp/sctp.h
+++ b/include/net/sctp/sctp.h
@@ -600,10 +600,15 @@ static inline __u32 sctp_mtu_payload(const struct sctp_sock *sp,
        return mtu ? mtu - overhead : overhead;
 }
 
+static inline __u32 sctp_dst_mtu(const struct dst_entry *dst)
+{
+       return SCTP_TRUNC4(max_t(__u32, dst_mtu(dst),
+                                SCTP_DEFAULT_MINSEGMENT));
+}
+
 static inline bool sctp_transport_pmtu_check(struct sctp_transport *t)
 {
-       __u32 pmtu = max_t(size_t, SCTP_TRUNC4(dst_mtu(t->dst)),
-                          SCTP_DEFAULT_MINSEGMENT);
+       __u32 pmtu = sctp_dst_mtu(t->dst);
 
        if (t->pathmtu == pmtu)
                return true;

diff --git a/net/sctp/associola.c b/net/sctp/associola.c
index a29025418b96015dd0240013b0a7c636194da67b..039fdb862b1797686bf7e5e911379b5b47ea58f7 100644 (file)
--- a/net/sctp/associola.c
+++ b/net/sctp/associola.c
@@ -1405,11 +1405,9 @@ void sctp_assoc_sync_pmtu(struct sctp_association *asoc)
                return;
 
        /* Get the lowest pmtu of all the transports. */
-       list_for_each_entry(t, &asoc->peer.transport_addr_list,
-                               transports) {
+       list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
                if (t->pmtu_pending && t->dst) {
-                       sctp_transport_update_pmtu(
-                                       t, SCTP_TRUNC4(dst_mtu(t->dst)));
+                       sctp_transport_update_pmtu(t, sctp_dst_mtu(t->dst));
                        t->pmtu_pending = 0;
                }
                if (!pmtu || (t->pathmtu < pmtu))

diff --git a/net/sctp/transport.c b/net/sctp/transport.c
index c5fc3aed08a18658448b528b07dbb13900686313..ed73a9d91b83eadd3eb8d681fda104fe71562c3f 100644 (file)
--- a/net/sctp/transport.c
+++ b/net/sctp/transport.c
@@ -242,9 +242,9 @@ void sctp_transport_pmtu(struct sctp_transport *transport, struct sock *sk)
                                                &transport->fl, sk);
        }
 
-       if (transport->dst) {
-               transport->pathmtu = SCTP_TRUNC4(dst_mtu(transport->dst));
-       } else
+       if (transport->dst)
+               transport->pathmtu = sctp_dst_mtu(transport->dst);
+       else
                transport->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
 }