Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 5e8f3f70 authored by Vlad Yasevich's avatar Vlad Yasevich Committed by David S. Miller
Browse files

sctp: simplify sctp listening code 



sctp_inet_listen() call is split between UDP and TCP style.  Looking
at the code, the two functions are almost the same and can be
merged into a single helper.  This also fixes a bug that was
fixed in the UDP function, but missed in the TCP function.

Signed-off-by: default avatarVlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3bcb1255

net/sctp/socket.c

+50 −102
Original line number Diff line number Diff line
@@ -5843,36 +5843,27 @@ static int sctp_get_port(struct sock *sk, unsigned short snum) 
}



/*

 * 3.1.3 listen() - UDP Style Syntax

 *

 *   By default, new associations are not accepted for UDP style sockets.

 *   An application uses listen() to mark a socket as being able to

 *   accept new associations.

 *  Move a socket to LISTENING state.

 */

SCTP_STATIC int sctp_seqpacket_listen(struct sock *sk, int backlog)

SCTP_STATIC int sctp_listen_start(struct sock *sk, int backlog)

{

	struct sctp_sock *sp = sctp_sk(sk);

	struct sctp_endpoint *ep = sp->ep;

	struct crypto_hash *tfm = NULL;



	/* Only UDP style sockets that are not peeled off are allowed to

	 * listen().

	 */

	if (!sctp_style(sk, UDP))

		return -EINVAL;



	/* If backlog is zero, disable listening. */

	if (!backlog) {

		if (sctp_sstate(sk, CLOSED))

			return 0;



		sctp_unhash_endpoint(ep);

		sk->sk_state = SCTP_SS_CLOSED;

		return 0;

	/* Allocate HMAC for generating cookie. */

	if (!sctp_sk(sk)->hmac && sctp_hmac_alg) {

		tfm = crypto_alloc_hash(sctp_hmac_alg, 0, CRYPTO_ALG_ASYNC);

		if (IS_ERR(tfm)) {

			if (net_ratelimit()) {

				printk(KERN_INFO

				       "SCTP: failed to load transform for %s: %ld\n",

					sctp_hmac_alg, PTR_ERR(tfm));

			}

			return -ENOSYS;

		}

		sctp_sk(sk)->hmac = tfm;

	}



	/* Return if we are already listening. */

	if (sctp_sstate(sk, LISTENING))

		return 0;



	/*

	 * If a bind() or sctp_bindx() is not called prior to a listen()
@@ -5884,7 +5875,6 @@ SCTP_STATIC int sctp_seqpacket_listen(struct sock *sk, int backlog) 
	 * extensions draft, but follows the practice as seen in TCP

	 * sockets.

	 *

	 * Additionally, turn off fastreuse flag since we are not listening

	 */

	sk->sk_state = SCTP_SS_LISTENING;

	if (!ep->base.bind_addr.port) {
@@ -5895,113 +5885,71 @@ SCTP_STATIC int sctp_seqpacket_listen(struct sock *sk, int backlog) 
			sk->sk_state = SCTP_SS_CLOSED;

			return -EADDRINUSE;

		}

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

	}



	sk->sk_max_ack_backlog = backlog;

	sctp_hash_endpoint(ep);

	return 0;

}



/*

 * 4.1.3 listen() - TCP Style Syntax

 * 4.1.3 / 5.1.3 listen()

 *

 *   Applications uses listen() to ready the SCTP endpoint for accepting

 *   inbound associations.

 */

SCTP_STATIC int sctp_stream_listen(struct sock *sk, int backlog)

{

	struct sctp_sock *sp = sctp_sk(sk);

	struct sctp_endpoint *ep = sp->ep;



	/* If backlog is zero, disable listening. */

	if (!backlog) {

		if (sctp_sstate(sk, CLOSED))

			return 0;



		sctp_unhash_endpoint(ep);

		sk->sk_state = SCTP_SS_CLOSED;

		return 0;

	}



	if (sctp_sstate(sk, LISTENING))

		return 0;



	/*

	 * If a bind() or sctp_bindx() is not called prior to a listen()

	 * call that allows new associations to be accepted, the system

	 * picks an ephemeral port and will choose an address set equivalent

	 * to binding with a wildcard address.

 *   By default, new associations are not accepted for UDP style sockets.

 *   An application uses listen() to mark a socket as being able to

 *   accept new associations.

 *

 *   On TCP style sockets, applications use listen() to ready the SCTP

 *   endpoint for accepting inbound associations.

 *

 *   On both types of endpoints a backlog of '0' disables listening.

 *

	 * This is not currently spelled out in the SCTP sockets

	 * extensions draft, but follows the practice as seen in TCP

	 * sockets.

	 */

	sk->sk_state = SCTP_SS_LISTENING;

	if (!ep->base.bind_addr.port) {

		if (sctp_autobind(sk))

			return -EAGAIN;

	} else

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



	sk->sk_max_ack_backlog = backlog;

	sctp_hash_endpoint(ep);

	return 0;

}



/*

 *  Move a socket to LISTENING state.

 */

int sctp_inet_listen(struct socket *sock, int backlog)

{

	struct sock *sk = sock->sk;

	struct crypto_hash *tfm = NULL;

	struct sctp_endpoint *ep = sctp_sk(sk)->ep;

	int err = -EINVAL;



	if (unlikely(backlog < 0))

		goto out;

		return err;



	sctp_lock_sock(sk);



	/* Peeled-off sockets are not allowed to listen().  */

	if (sctp_style(sk, UDP_HIGH_BANDWIDTH))

		goto out;



	if (sock->state != SS_UNCONNECTED)

		goto out;



	/* Allocate HMAC for generating cookie. */

	if (!sctp_sk(sk)->hmac && sctp_hmac_alg) {

		tfm = crypto_alloc_hash(sctp_hmac_alg, 0, CRYPTO_ALG_ASYNC);

		if (IS_ERR(tfm)) {

			if (net_ratelimit()) {

				printk(KERN_INFO

				       "SCTP: failed to load transform for %s: %ld\n",

					sctp_hmac_alg, PTR_ERR(tfm));

			}

			err = -ENOSYS;

	/* If backlog is zero, disable listening. */

	if (!backlog) {

		if (sctp_sstate(sk, CLOSED))

			goto out;

		}

	}



	switch (sock->type) {

	case SOCK_SEQPACKET:

		err = sctp_seqpacket_listen(sk, backlog);

		break;

	case SOCK_STREAM:

		err = sctp_stream_listen(sk, backlog);

		break;

	default:

		break;

		err = 0;

		sctp_unhash_endpoint(ep);

		sk->sk_state = SCTP_SS_CLOSED;

		if (sk->sk_reuse)

			sctp_sk(sk)->bind_hash->fastreuse = 1;

		goto out;

	}



	/* If we are already listening, just update the backlog */

	if (sctp_sstate(sk, LISTENING))

		sk->sk_max_ack_backlog = backlog;

	else {

		err = sctp_listen_start(sk, backlog);

		if (err)

		goto cleanup;

			goto out;

	}



	/* Store away the transform reference. */

	if (!sctp_sk(sk)->hmac)

		sctp_sk(sk)->hmac = tfm;

	err = 0;

out:

	sctp_release_sock(sk);

	return err;

cleanup:

	crypto_free_hash(tfm);

	goto out;

}



/*