[SCTP]: Allow unspecified port in sctp_bindx()

Allow sctp_bindx() to accept multiple address with
unspecified port.  In this case, all addresses inherit
the first bound port.  We still catch full mis-matches.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Acked-by: Sridhar Samudrala <sri@us.ibm.com>

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index d370c945a7578e659c1ce9cd171bcedd30fa2950..a5b6e559451ed65bd66556ac82c7a6256add9ce5 100644 (file)
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -333,12 +333,19 @@ SCTP_STATIC int sctp_do_bind(struct sock *sk, union sctp_addr *addr, int len)
        if (!sp->pf->bind_verify(sp, addr))
                return -EADDRNOTAVAIL;
 
-       /* We must either be unbound, or bind to the same port.  */
-       if (bp->port && (snum != bp->port)) {
-               SCTP_DEBUG_PRINTK("sctp_do_bind:"
+       /* We must either be unbound, or bind to the same port.
+        * It's OK to allow 0 ports if we are already bound.
+        * We'll just inhert an already bound port in this case
+        */
+       if (bp->port) {
+               if (!snum)
+                       snum = bp->port;
+               else if (snum != bp->port) {
+                       SCTP_DEBUG_PRINTK("sctp_do_bind:"
                                  " New port %d does not match existing port "
                                  "%d.\n", snum, bp->port);
-               return -EINVAL;
+                       return -EINVAL;
+               }
        }
 
        if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))