/**
* release - destroy a TIPC socket
* @sock: socket to destroy
*
* This routine cleans up any messages that are still queued on the socket.
* For DGRAM and RDM socket types, all queued messages are rejected.
* For SEQPACKET and STREAM socket types, the first message is rejected
* and any others are discarded. (If the first message on a STREAM socket
* is partially-read, it is discarded and the next one is rejected instead.)
*
* NOTE: Rejected messages are not necessarily returned to the sender! They
* are returned or discarded according to the "destination droppable" setting
* specified for the message by the sender.
*
* Returns 0 on success, errno otherwise
*/
static int release(struct socket *sock)
{
struct sock *sk = sock->sk;
struct tipc_port *tport;
struct sk_buff *buf;
int res;
/*
* Exit if socket isn't fully initialized (occurs when a failed accept()
* releases a pre-allocated child socket that was never used)
*/
if (sk == NULL)
return 0;
tport = tipc_sk_port(sk);
lock_sock(sk);
/*
* Reject all unreceived messages, except on an active connection
* (which disconnects locally & sends a 'FIN+' to peer)
*/
while (sock->state != SS_DISCONNECTING) {
buf = __skb_dequeue(&sk->sk_receive_queue);
if (buf == NULL)
break;
atomic_dec(&tipc_queue_size);
if (TIPC_SKB_CB(buf)->handle != 0)
kfree_skb(buf);
else {
if ((sock->state == SS_CONNECTING) ||
(sock->state == SS_CONNECTED)) {
sock->state = SS_DISCONNECTING;
tipc_disconnect(tport->ref);
}
tipc_reject_msg(buf, TIPC_ERR_NO_PORT);
}
}
/*
* Delete TIPC port; this ensures no more messages are queued
* (also disconnects an active connection & sends a 'FIN-' to peer)
*/
res = tipc_deleteport(tport->ref);
/* Discard any remaining (connection-based) messages in receive queue */
discard_rx_queue(sk);
/* Reject any messages that accumulated in backlog queue */
sock->state = SS_DISCONNECTING;
release_sock(sk);
sock_put(sk);
sock->sk = NULL;
return res;
}
static int shutdown(struct socket *sock, int how)
{
struct sock *sk = sock->sk;
struct tipc_port *tport = tipc_sk_port(sk);
struct sk_buff *buf;
int res;
if (how != SHUT_RDWR)
return -EINVAL;
lock_sock(sk);
switch (sock->state) {
case SS_CONNECTING:
case SS_CONNECTED:
/* Disconnect and send a 'FIN+' or 'FIN-' message to peer */
restart:
buf = __skb_dequeue(&sk->sk_receive_queue);
if (buf) {
atomic_dec(&tipc_queue_size);
if (TIPC_SKB_CB(buf)->handle != 0) {
kfree_skb(buf);
goto restart;
}
tipc_disconnect(tport->ref);
tipc_reject_msg(buf, TIPC_CONN_SHUTDOWN);
} else {
tipc_shutdown(tport->ref);
}
sock->state = SS_DISCONNECTING;
/* fall through */
case SS_DISCONNECTING:
/* Discard any unreceived messages; wake up sleeping tasks */
discard_rx_queue(sk);
if (waitqueue_active(sk_sleep(sk)))
wake_up_interruptible(sk_sleep(sk));
res = 0;
break;
default:
res = -ENOTCONN;
}
release_sock(sk);
return res;
}
/**
* shutdown - shutdown socket connection
* @sock: socket structure
* @how: direction to close (must be SHUT_RDWR)
*
* Terminates connection (if necessary), then purges socket's receive queue.
*
* Returns 0 on success, errno otherwise
*/
static int shutdown(struct socket *sock, int how)
{
struct sock *sk = sock->sk;
struct tipc_port *tport = tipc_sk_port(sk);
struct sk_buff *buf;
int res;
if (how != SHUT_RDWR)
return -EINVAL;
lock_sock(sk);
switch (sock->state) {
case SS_CONNECTING:
case SS_CONNECTED:
restart:
/* Disconnect and send a 'FIN+' or 'FIN-' message to peer */
buf = __skb_dequeue(&sk->sk_receive_queue);
if (buf) {
if (TIPC_SKB_CB(buf)->handle != 0) {
kfree_skb(buf);
goto restart;
}
tipc_disconnect(tport->ref);
tipc_reject_msg(buf, TIPC_CONN_SHUTDOWN);
} else {
tipc_shutdown(tport->ref);
}
sock->state = SS_DISCONNECTING;
/* fall through */
case SS_DISCONNECTING:
/* Discard any unreceived messages */
__skb_queue_purge(&sk->sk_receive_queue);
/* Wake up anyone sleeping in poll */
sk->sk_state_change(sk);
res = 0;
break;
default:
res = -ENOTCONN;
}
release_sock(sk);
return res;
}
static void async_disconnect(unsigned long portref)
{
tipc_disconnect((u32)portref);
}