Skip to content

Commit

Permalink
sctp: simplify sctp listening code
Browse files Browse the repository at this point in the history 
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: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
  • Loading branch information
Vlad Yasevich authored and David S. Miller committed Mar 13, 2009
1 parent 3bcb125 commit 5e8f3f7
Showing 1 changed file with 50 additions and 102 deletions.
152 changes: 50 additions & 102 deletions net/sctp/socket.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -5843,37 +5843,28 @@ 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()
* call that allows new associations to be accepted, the system
Expand All @@ -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) {
Expand All @@ -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;
}

sctp_hash_endpoint(ep);
return 0;
}

/*
* 4.1.3 listen() - TCP Style Syntax
*
* 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.
*
* 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;
}

/*
* 4.1.3 / 5.1.3 listen()
*
* 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.
*
* 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 (err)
goto cleanup;
/* 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 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;
}

/*
Expand Down

0 comments on commit 5e8f3f7

Please sign in to comment.