tipc: create TIPC_OPEN as a new sk_state

In this commit, we create a new tipc socket state TIPC_OPEN in
sk_state. We primarily replace the SS_UNCONNECTED sock->state with
TIPC_OPEN.
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/socket.c

@@ -53,6 +53,7 @@
 enum {
 	TIPC_LISTEN = TCP_LISTEN,
 	TIPC_ESTABLISHED = TCP_ESTABLISHED,
+	TIPC_OPEN = TCP_CLOSE,
 };
 
 /**
@@ -348,16 +349,21 @@ static bool tsk_peer_msg(struct tipc_sock *tsk, struct tipc_msg *msg)
 static int tipc_set_sk_state(struct sock *sk, int state)
 {
 	int oldstate = sk->sk_socket->state;
+	int oldsk_state = sk->sk_state;
 	int res = -EINVAL;
 
 	switch (state) {
+	case TIPC_OPEN:
+		res = 0;
+		break;
 	case TIPC_LISTEN:
-		if (oldstate == SS_UNCONNECTED)
+		if (oldsk_state == TIPC_OPEN)
 			res = 0;
 		break;
 	case TIPC_ESTABLISHED:
 		if (oldstate == SS_CONNECTING ||
-		    oldstate == SS_UNCONNECTED)
+		    oldstate == SS_UNCONNECTED ||
+		    oldsk_state == TIPC_OPEN)
 			res = 0;
 		break;
 	}
@@ -423,8 +429,8 @@ static int tipc_sk_create(struct net *net, struct socket *sock,
 
 	/* Finish initializing socket data structures */
 	sock->ops = ops;
-	sock->state = SS_UNCONNECTED;
 	sock_init_data(sock, sk);
+	tipc_set_sk_state(sk, TIPC_OPEN);
 	if (tipc_sk_insert(tsk)) {
 		pr_warn("Socket create failed; port number exhausted\n");
 		return -EINVAL;
@@ -448,6 +454,7 @@ static int tipc_sk_create(struct net *net, struct socket *sock,
 		if (sock->type == SOCK_DGRAM)
 			tsk_set_unreliable(tsk, true);
 	}
+
 	return 0;
 }
 
@@ -652,28 +659,6 @@ static int tipc_getname(struct socket *sock, struct sockaddr *uaddr,
  * exits.  TCP and other protocols seem to rely on higher level poll routines
  * to handle any preventable race conditions, so TIPC will do the same ...
  *
- * TIPC sets the returned events as follows:
- *
- * socket state		flags set
- * ------------		---------
- * unconnected		no read flags
- *			POLLOUT if port is not congested
- *
- * connecting		POLLIN/POLLRDNORM if ACK/NACK in rx queue
- *			no write flags
- *
- * connected		POLLIN/POLLRDNORM if data in rx queue
- *			POLLOUT if port is not congested
- *
- * disconnecting	POLLIN/POLLRDNORM/POLLHUP
- *			no write flags
- *
- * listening		POLLIN if SYN in rx queue
- *			no write flags
- *
- * ready		POLLIN/POLLRDNORM if data in rx queue
- * [connectionless]	POLLOUT (since port cannot be congested)
- *
  * IMPORTANT: The fact that a read or write operation is indicated does NOT
  * imply that the operation will succeed, merely that it should be performed
  * and will not block.
@@ -687,27 +672,7 @@ static unsigned int tipc_poll(struct file *file, struct socket *sock,
 
 	sock_poll_wait(file, sk_sleep(sk), wait);
 
-	if (tipc_sk_type_connectionless(sk)) {
-		if (!tsk->link_cong)
-			mask |= POLLOUT;
-		if (!skb_queue_empty(&sk->sk_receive_queue))
-			mask |= (POLLIN | POLLRDNORM);
-		return mask;
-	}
-
 	switch ((int)sock->state) {
-	case SS_UNCONNECTED:
-		switch (sk->sk_state) {
-		case TIPC_LISTEN:
-			if (!skb_queue_empty(&sk->sk_receive_queue))
-				mask |= (POLLIN | POLLRDNORM);
-			break;
-		default:
-			if (!tsk->link_cong)
-				mask |= POLLOUT;
-			break;
-		}
-		break;
 	case SS_CONNECTED:
 		if (!tsk->link_cong && !tsk_conn_cong(tsk))
 			mask |= POLLOUT;
@@ -719,6 +684,20 @@ static unsigned int tipc_poll(struct file *file, struct socket *sock,
 	case SS_DISCONNECTING:
 		mask = (POLLIN | POLLRDNORM | POLLHUP);
 		break;
+	default:
+		switch (sk->sk_state) {
+		case TIPC_OPEN:
+			if (!tsk->link_cong)
+				mask |= POLLOUT;
+			if (tipc_sk_type_connectionless(sk) &&
+			    (!skb_queue_empty(&sk->sk_receive_queue)))
+				mask |= (POLLIN | POLLRDNORM);
+			break;
+		case TIPC_LISTEN:
+			if (!skb_queue_empty(&sk->sk_receive_queue))
+				mask |= (POLLIN | POLLRDNORM);
+			break;
+		}
 	}
 
 	return mask;
@@ -965,7 +944,7 @@ static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dsz)
 	if (!is_connectionless) {
 		if (sk->sk_state == TIPC_LISTEN)
 			return -EPIPE;
-		if (sock->state != SS_UNCONNECTED)
+		if (sk->sk_state != TIPC_OPEN)
 			return -EISCONN;
 		if (tsk->published)
 			return -EOPNOTSUPP;
@@ -1400,7 +1379,7 @@ static int tipc_recvmsg(struct socket *sock, struct msghdr *m, size_t buf_len,
 
 	lock_sock(sk);
 
-	if (!is_connectionless && unlikely(sock->state == SS_UNCONNECTED)) {
+	if (!is_connectionless && unlikely(sk->sk_state == TIPC_OPEN)) {
 		res = -ENOTCONN;
 		goto exit;
 	}
@@ -1497,7 +1476,7 @@ static int tipc_recv_stream(struct socket *sock, struct msghdr *m,
 
 	lock_sock(sk);
 
-	if (unlikely(sock->state == SS_UNCONNECTED)) {
+	if (unlikely(sk->sk_state == TIPC_OPEN)) {
 		res = -ENOTCONN;
 		goto exit;
 	}
@@ -1689,17 +1668,22 @@ static bool filter_connect(struct tipc_sock *tsk, struct sk_buff *skb)
 		msg_set_dest_droppable(hdr, 1);
 		return false;
 
-	case SS_UNCONNECTED:
+	case SS_DISCONNECTING:
+		break;
+	}
 
+	switch (sk->sk_state) {
+	case TIPC_OPEN:
+		break;
+	case TIPC_LISTEN:
 		/* Accept only SYN message */
 		if (!msg_connected(hdr) && !(msg_errcode(hdr)))
 			return true;
 		break;
-	case SS_DISCONNECTING:
-		break;
 	default:
-		pr_err("Unknown socket state %u\n", sock->state);
+		pr_err("Unknown sk_state %u\n", sk->sk_state);
 	}
+
 	return false;
 }
 
@@ -2008,8 +1992,9 @@ static int tipc_connect(struct socket *sock, struct sockaddr *dest,
 	}
 
 	previous = sock->state;
-	switch (sock->state) {
-	case SS_UNCONNECTED:
+
+	switch (sk->sk_state) {
+	case TIPC_OPEN:
 		/* Send a 'SYN-' to destination */
 		m.msg_name = dest;
 		m.msg_namelen = destlen;
@@ -2029,6 +2014,10 @@ static int tipc_connect(struct socket *sock, struct sockaddr *dest,
 		 * case is EINPROGRESS, rather than EALREADY.
 		 */
 		res = -EINPROGRESS;
+		break;
+	}
+
+	switch (sock->state) {
 	case SS_CONNECTING:
 		if (previous == SS_CONNECTING)
 			res = -EALREADY;