Commit 4e54064e authored by Vlad Yasevich's avatar Vlad Yasevich Committed by David S. Miller
Browse files

sctp: Allow only 1 listening socket with SO_REUSEADDR 



When multiple socket bind to the same port with SO_REUSEADDR,
only 1 can be listining.

Signed-off-by: default avatarVlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 23b29ed8

net/sctp/socket.c

+16 −9
Original line number Diff line number Diff line
@@ -377,19 +377,20 @@ SCTP_STATIC int sctp_do_bind(struct sock *sk, union sctp_addr *addr, int len) 
	if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))

		return -EACCES;



	/* See if the address matches any of the addresses we may have

	 * already bound before checking against other endpoints.

	 */

	if (sctp_bind_addr_match(bp, addr, sp))

		return -EINVAL;



	/* Make sure we are allowed to bind here.

	 * The function sctp_get_port_local() does duplicate address

	 * detection.

	 */

	addr->v4.sin_port = htons(snum);

	if ((ret = sctp_get_port_local(sk, addr))) {

		if (ret == (long) sk) {

			/* This endpoint has a conflicting address. */

			return -EINVAL;

		} else {

		return -EADDRINUSE;

	}

	}



	/* Refresh ephemeral port.  */

	if (!bp->port)
@@ -5584,8 +5585,9 @@ static long sctp_get_port_local(struct sock *sk, union sctp_addr *addr) 
			struct sctp_endpoint *ep2;

			ep2 = sctp_sk(sk2)->ep;



			if (reuse && sk2->sk_reuse &&

			    sk2->sk_state != SCTP_SS_LISTENING)

			if (sk == sk2 ||

			    (reuse && sk2->sk_reuse &&

			     sk2->sk_state != SCTP_SS_LISTENING))

				continue;



			if (sctp_bind_addr_conflict(&ep2->base.bind_addr, addr,
@@ -5702,8 +5704,13 @@ SCTP_STATIC int sctp_seqpacket_listen(struct sock *sk, int backlog) 
	if (!ep->base.bind_addr.port) {

		if (sctp_autobind(sk))

			return -EAGAIN;

	} else

	} else {

		if (sctp_get_port(sk, inet_sk(sk)->num)) {

			sk->sk_state = SCTP_SS_CLOSED;

			return -EADDRINUSE;

		}

		sctp_sk(sk)->bind_hash->fastreuse = 0;

	}



	sctp_hash_endpoint(ep);

	return 0;