/**
* filter_connect - Handle all incoming messages for a connection-based socket
* @tsock: TIPC socket
* @msg: message
*
* Returns TIPC error status code and socket error status code
* once it encounters some errors
*/
static u32 filter_connect(struct tipc_sock *tsock, struct sk_buff **buf)
{
struct socket *sock = tsock->sk.sk_socket;
struct tipc_msg *msg = buf_msg(*buf);
struct sock *sk = &tsock->sk;
u32 retval = TIPC_ERR_NO_PORT;
int res;
if (msg_mcast(msg))
return retval;
switch ((int)sock->state) {
case SS_CONNECTED:
/* Accept only connection-based messages sent by peer */
if (msg_connected(msg) && tipc_port_peer_msg(tsock->p, msg)) {
if (unlikely(msg_errcode(msg))) {
sock->state = SS_DISCONNECTING;
__tipc_disconnect(tsock->p);
}
retval = TIPC_OK;
}
break;
case SS_CONNECTING:
/* Accept only ACK or NACK message */
if (unlikely(msg_errcode(msg))) {
sock->state = SS_DISCONNECTING;
sk->sk_err = ECONNREFUSED;
retval = TIPC_OK;
break;
}
if (unlikely(!msg_connected(msg)))
break;
res = auto_connect(sock, msg);
if (res) {
sock->state = SS_DISCONNECTING;
sk->sk_err = -res;
retval = TIPC_OK;
break;
}
/* If an incoming message is an 'ACK-', it should be
* discarded here because it doesn't contain useful
* data. In addition, we should try to wake up
* connect() routine if sleeping.
*/
if (msg_data_sz(msg) == 0) {
kfree_skb(*buf);
*buf = NULL;
if (waitqueue_active(sk_sleep(sk)))
wake_up_interruptible(sk_sleep(sk));
}
retval = TIPC_OK;
break;
case SS_LISTENING:
case SS_UNCONNECTED:
/* Accept only SYN message */
if (!msg_connected(msg) && !(msg_errcode(msg)))
retval = TIPC_OK;
break;
case SS_DISCONNECTING:
break;
default:
pr_err("Unknown socket state %u\n", sock->state);
}
return retval;
}
/**
* filter_rcv - validate incoming message
* @sk: socket
* @buf: message
*
* Enqueues message on receive queue if acceptable; optionally handles
* disconnect indication for a connected socket.
*
* Called with socket lock already taken; port lock may also be taken.
*
* Returns TIPC error status code (TIPC_OK if message is not to be rejected)
*/
static u32 filter_rcv(struct sock *sk, struct sk_buff *buf)
{
struct socket *sock = sk->sk_socket;
struct tipc_msg *msg = buf_msg(buf);
u32 recv_q_len;
/* Reject message if it is wrong sort of message for socket */
if (msg_type(msg) > TIPC_DIRECT_MSG)
return TIPC_ERR_NO_PORT;
if (sock->state == SS_READY) {
if (msg_connected(msg))
return TIPC_ERR_NO_PORT;
} else {
if (msg_mcast(msg))
return TIPC_ERR_NO_PORT;
if (sock->state == SS_CONNECTED) {
if (!msg_connected(msg) ||
!tipc_port_peer_msg(tipc_sk_port(sk), msg))
return TIPC_ERR_NO_PORT;
} else if (sock->state == SS_CONNECTING) {
if (!msg_connected(msg) && (msg_errcode(msg) == 0))
return TIPC_ERR_NO_PORT;
} else if (sock->state == SS_LISTENING) {
if (msg_connected(msg) || msg_errcode(msg))
return TIPC_ERR_NO_PORT;
} else if (sock->state == SS_DISCONNECTING) {
return TIPC_ERR_NO_PORT;
} else /* (sock->state == SS_UNCONNECTED) */ {
if (msg_connected(msg) || msg_errcode(msg))
return TIPC_ERR_NO_PORT;
}
}
/* Reject message if there isn't room to queue it */
recv_q_len = (u32)atomic_read(&tipc_queue_size);
if (unlikely(recv_q_len >= OVERLOAD_LIMIT_BASE)) {
if (rx_queue_full(msg, recv_q_len, OVERLOAD_LIMIT_BASE))
return TIPC_ERR_OVERLOAD;
}
recv_q_len = skb_queue_len(&sk->sk_receive_queue);
if (unlikely(recv_q_len >= (OVERLOAD_LIMIT_BASE / 2))) {
if (rx_queue_full(msg, recv_q_len, OVERLOAD_LIMIT_BASE / 2))
return TIPC_ERR_OVERLOAD;
}
/* Enqueue message (finally!) */
TIPC_SKB_CB(buf)->handle = 0;
atomic_inc(&tipc_queue_size);
__skb_queue_tail(&sk->sk_receive_queue, buf);
/* Initiate connection termination for an incoming 'FIN' */
if (unlikely(msg_errcode(msg) && (sock->state == SS_CONNECTED))) {
sock->state = SS_DISCONNECTING;
tipc_disconnect_port(tipc_sk_port(sk));
}
if (waitqueue_active(sk_sleep(sk)))
wake_up_interruptible(sk_sleep(sk));
return TIPC_OK;
}
