tipc: remove socket state SS_READY

Until now, tipc socket state SS_READY declares that the socket is a
connectionless socket.

In this commit, we remove the state SS_READY and replace it with a
condition which returns true for datagram / connectionless sockets.

Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/socket.c

@@ -45,7 +45,6 @@
 #include "netlink.h"
 
 #define SS_LISTENING		-1	/* socket is listening */
-#define SS_READY		-2	/* socket is connectionless */
 
 #define CONN_TIMEOUT_DEFAULT	8000	/* default connect timeout = 8s */
 #define CONN_PROBING_INTERVAL	msecs_to_jiffies(3600000)  /* [ms] => 1 h */
@@ -294,6 +293,16 @@ static bool tipc_sk_connected(struct sock *sk)
 	return sk->sk_socket->state == SS_CONNECTED;
 }
 
+/* tipc_sk_type_connectionless - check if the socket is datagram socket
+ * @sk: socket
+ *
+ * Returns true if connection less, false otherwise
+ */
+static bool tipc_sk_type_connectionless(struct sock *sk)
+{
+	return sk->sk_type == SOCK_RDM || sk->sk_type == SOCK_DGRAM;
+}
+
 /* tsk_peer_msg - verify if message was sent by connected port's peer
  *
  * Handles cases where the node's network address has changed from
@@ -345,7 +354,6 @@ static int tipc_sk_create(struct net *net, struct socket *sock,
 {
 	struct tipc_net *tn;
 	const struct proto_ops *ops;
-	socket_state state;
 	struct sock *sk;
 	struct tipc_sock *tsk;
 	struct tipc_msg *msg;
@@ -357,16 +365,13 @@ static int tipc_sk_create(struct net *net, struct socket *sock,
 	switch (sock->type) {
 	case SOCK_STREAM:
 		ops = &stream_ops;
-		state = SS_UNCONNECTED;
 		break;
 	case SOCK_SEQPACKET:
 		ops = &packet_ops;
-		state = SS_UNCONNECTED;
 		break;
 	case SOCK_DGRAM:
 	case SOCK_RDM:
 		ops = &msg_ops;
-		state = SS_READY;
 		break;
 	default:
 		return -EPROTOTYPE;
@@ -387,7 +392,7 @@ static int tipc_sk_create(struct net *net, struct socket *sock,
 
 	/* Finish initializing socket data structures */
 	sock->ops = ops;
-	sock->state = state;
+	sock->state = SS_UNCONNECTED;
 	sock_init_data(sock, sk);
 	if (tipc_sk_insert(tsk)) {
 		pr_warn("Socket create failed; port number exhausted\n");
@@ -407,7 +412,7 @@ static int tipc_sk_create(struct net *net, struct socket *sock,
 	tsk->snd_win = tsk_adv_blocks(RCVBUF_MIN);
 	tsk->rcv_win = tsk->snd_win;
 
-	if (sock->state == SS_READY) {
+	if (tipc_sk_type_connectionless(sk)) {
 		tsk_set_unreturnable(tsk, true);
 		if (sock->type == SOCK_DGRAM)
 			tsk_set_unreliable(tsk, true);
@@ -651,12 +656,19 @@ 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:
 		if (!tsk->link_cong)
 			mask |= POLLOUT;
 		break;
-	case SS_READY:
 	case SS_CONNECTED:
 		if (!tsk->link_cong && !tsk_conn_cong(tsk))
 			mask |= POLLOUT;
@@ -893,6 +905,7 @@ static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dsz)
 	struct tipc_msg *mhdr = &tsk->phdr;
 	u32 dnode, dport;
 	struct sk_buff_head pktchain;
+	bool is_connectionless = tipc_sk_type_connectionless(sk);
 	struct sk_buff *skb;
 	struct tipc_name_seq *seq;
 	struct iov_iter save;
@@ -903,7 +916,7 @@ static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dsz)
 	if (dsz > TIPC_MAX_USER_MSG_SIZE)
 		return -EMSGSIZE;
 	if (unlikely(!dest)) {
-		if (sock->state == SS_READY && tsk->peer.family == AF_TIPC)
+		if (is_connectionless && tsk->peer.family == AF_TIPC)
 			dest = &tsk->peer;
 		else
 			return -EDESTADDRREQ;
@@ -911,7 +924,7 @@ static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dsz)
 		   dest->family != AF_TIPC) {
 		return -EINVAL;
 	}
-	if (unlikely(sock->state != SS_READY)) {
+	if (!is_connectionless) {
 		if (sock->state == SS_LISTENING)
 			return -EPIPE;
 		if (sock->state != SS_UNCONNECTED)
@@ -966,7 +979,7 @@ new_mtu:
 		TIPC_SKB_CB(skb)->wakeup_pending = tsk->link_cong;
 		rc = tipc_node_xmit(net, &pktchain, dnode, tsk->portid);
 		if (likely(!rc)) {
-			if (sock->state != SS_READY)
+			if (!is_connectionless)
 				sock->state = SS_CONNECTING;
 			return dsz;
 		}
@@ -1337,6 +1350,7 @@ static int tipc_recvmsg(struct socket *sock, struct msghdr *m, size_t buf_len,
 	struct tipc_sock *tsk = tipc_sk(sk);
 	struct sk_buff *buf;
 	struct tipc_msg *msg;
+	bool is_connectionless = tipc_sk_type_connectionless(sk);
 	long timeo;
 	unsigned int sz;
 	u32 err;
@@ -1348,7 +1362,7 @@ static int tipc_recvmsg(struct socket *sock, struct msghdr *m, size_t buf_len,
 
 	lock_sock(sk);
 
-	if (unlikely(sock->state == SS_UNCONNECTED)) {
+	if (!is_connectionless && unlikely(sock->state == SS_UNCONNECTED)) {
 		res = -ENOTCONN;
 		goto exit;
 	}
@@ -1393,8 +1407,8 @@ restart:
 			goto exit;
 		res = sz;
 	} else {
-		if ((sock->state == SS_READY) ||
-		    ((err == TIPC_CONN_SHUTDOWN) || m->msg_control))
+		if (is_connectionless || err == TIPC_CONN_SHUTDOWN ||
+		    m->msg_control)
 			res = 0;
 		else
 			res = -ECONNRESET;
@@ -1403,7 +1417,7 @@ restart:
 	if (unlikely(flags & MSG_PEEK))
 		goto exit;
 
-	if (likely(sock->state != SS_READY)) {
+	if (likely(!is_connectionless)) {
 		tsk->rcv_unacked += tsk_inc(tsk, hlen + sz);
 		if (unlikely(tsk->rcv_unacked >= (tsk->rcv_win / 4)))
 			tipc_sk_send_ack(tsk);
@@ -1699,7 +1713,6 @@ static unsigned int rcvbuf_limit(struct sock *sk, struct sk_buff *skb)
 static bool filter_rcv(struct sock *sk, struct sk_buff *skb,
 		       struct sk_buff_head *xmitq)
 {
-	struct socket *sock = sk->sk_socket;
 	struct tipc_sock *tsk = tipc_sk(sk);
 	struct tipc_msg *hdr = buf_msg(skb);
 	unsigned int limit = rcvbuf_limit(sk, skb);
@@ -1725,7 +1738,7 @@ static bool filter_rcv(struct sock *sk, struct sk_buff *skb,
 	}
 
 	/* Reject if wrong message type for current socket state */
-	if (unlikely(sock->state == SS_READY)) {
+	if (tipc_sk_type_connectionless(sk)) {
 		if (msg_connected(hdr)) {
 			err = TIPC_ERR_NO_PORT;
 			goto reject;
@@ -1935,7 +1948,7 @@ static int tipc_connect(struct socket *sock, struct sockaddr *dest,
 	lock_sock(sk);
 
 	/* DGRAM/RDM connect(), just save the destaddr */
-	if (sock->state == SS_READY) {
+	if (tipc_sk_type_connectionless(sk)) {
 		if (dst->family == AF_UNSPEC) {
 			memset(&tsk->peer, 0, sizeof(struct sockaddr_tipc));
 		} else if (destlen != sizeof(struct sockaddr_tipc)) {