1 files changed, 162 insertions, 232 deletions

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index aab4948f0aff..6cc7ddd2fb7c 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -55,6 +55,9 @@ struct tipc_sock {
 #define tipc_sk(sk) ((struct tipc_sock *)(sk))
 #define tipc_sk_port(sk) (tipc_sk(sk)->p)
 
+#define tipc_rx_ready(sock) (!skb_queue_empty(&sock->sk->sk_receive_queue) || \
+			(sock->state == SS_DISCONNECTING))
+
 static int backlog_rcv(struct sock *sk, struct sk_buff *skb);
 static u32 dispatch(struct tipc_port *tport, struct sk_buff *buf);
 static void wakeupdispatch(struct tipc_port *tport);
@@ -236,6 +239,7 @@ static int tipc_sk_create(struct net *net, struct socket *sock, int protocol,
 int tipc_sock_create_local(int type, struct socket **res)
 {
 	int rc;
+	struct sock *sk;
 
 	rc = sock_create_lite(AF_TIPC, type, 0, res);
 	if (rc < 0) {
@@ -244,6 +248,8 @@ int tipc_sock_create_local(int type, struct socket **res)
 	}
 	tipc_sk_create(&init_net, *res, 0, 1);
 
+	sk = (*res)->sk;
+
 	return 0;
 }
 
@@ -332,7 +338,7 @@ static int release(struct socket *sock)
 		buf = __skb_dequeue(&sk->sk_receive_queue);
 		if (buf == NULL)
 			break;
-		if (TIPC_SKB_CB(buf)->handle != NULL)
+		if (TIPC_SKB_CB(buf)->handle != 0)
 			kfree_skb(buf);
 		else {
 			if ((sock->state == SS_CONNECTING) ||
@@ -348,7 +354,7 @@ static int release(struct socket *sock)
 	 * Delete TIPC port; this ensures no more messages are queued
 	 * (also disconnects an active connection & sends a 'FIN-' to peer)
 	 */
-	res = tipc_deleteport(tport);
+	res = tipc_deleteport(tport->ref);
 
 	/* Discard any remaining (connection-based) messages in receive queue */
 	__skb_queue_purge(&sk->sk_receive_queue);
@@ -380,46 +386,30 @@ static int release(struct socket *sock)
  */
 static int bind(struct socket *sock, struct sockaddr *uaddr, int uaddr_len)
 {
-	struct sock *sk = sock->sk;
 	struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr;
-	struct tipc_port *tport = tipc_sk_port(sock->sk);
-	int res = -EINVAL;
+	u32 portref = tipc_sk_port(sock->sk)->ref;
 
-	lock_sock(sk);
-	if (unlikely(!uaddr_len)) {
-		res = tipc_withdraw(tport, 0, NULL);
-		goto exit;
-	}
+	if (unlikely(!uaddr_len))
+		return tipc_withdraw(portref, 0, NULL);
 
-	if (uaddr_len < sizeof(struct sockaddr_tipc)) {
-		res = -EINVAL;
-		goto exit;
-	}
-	if (addr->family != AF_TIPC) {
-		res = -EAFNOSUPPORT;
-		goto exit;
-	}
+	if (uaddr_len < sizeof(struct sockaddr_tipc))
+		return -EINVAL;
+	if (addr->family != AF_TIPC)
+		return -EAFNOSUPPORT;
 
 	if (addr->addrtype == TIPC_ADDR_NAME)
 		addr->addr.nameseq.upper = addr->addr.nameseq.lower;
-	else if (addr->addrtype != TIPC_ADDR_NAMESEQ) {
-		res = -EAFNOSUPPORT;
-		goto exit;
-	}
+	else if (addr->addrtype != TIPC_ADDR_NAMESEQ)
+		return -EAFNOSUPPORT;
 
 	if ((addr->addr.nameseq.type < TIPC_RESERVED_TYPES) &&
 	    (addr->addr.nameseq.type != TIPC_TOP_SRV) &&
-	    (addr->addr.nameseq.type != TIPC_CFG_SRV)) {
-		res = -EACCES;
-		goto exit;
-	}
+	    (addr->addr.nameseq.type != TIPC_CFG_SRV))
+		return -EACCES;
 
-	res = (addr->scope > 0) ?
-		tipc_publish(tport, addr->scope, &addr->addr.nameseq) :
-		tipc_withdraw(tport, -addr->scope, &addr->addr.nameseq);
-exit:
-	release_sock(sk);
-	return res;
+	return (addr->scope > 0) ?
+		tipc_publish(portref, addr->scope, &addr->addr.nameseq) :
+		tipc_withdraw(portref, -addr->scope, &addr->addr.nameseq);
 }
 
 /**
@@ -564,31 +554,6 @@ static int dest_name_check(struct sockaddr_tipc *dest, struct msghdr *m)
 	return 0;
 }
 
-static int tipc_wait_for_sndmsg(struct socket *sock, long *timeo_p)
-{
-	struct sock *sk = sock->sk;
-	struct tipc_port *tport = tipc_sk_port(sk);
-	DEFINE_WAIT(wait);
-	int done;
-
-	do {
-		int err = sock_error(sk);
-		if (err)
-			return err;
-		if (sock->state == SS_DISCONNECTING)
-			return -EPIPE;
-		if (!*timeo_p)
-			return -EAGAIN;
-		if (signal_pending(current))
-			return sock_intr_errno(*timeo_p);
-
-		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
-		done = sk_wait_event(sk, timeo_p, !tport->congested);
-		finish_wait(sk_sleep(sk), &wait);
-	} while (!done);
-	return 0;
-}
-
 /**
  * send_msg - send message in connectionless manner
  * @iocb: if NULL, indicates that socket lock is already held
@@ -608,9 +573,9 @@ static int send_msg(struct kiocb *iocb, struct socket *sock,
 {
 	struct sock *sk = sock->sk;
 	struct tipc_port *tport = tipc_sk_port(sk);
-	DECLARE_SOCKADDR(struct sockaddr_tipc *, dest, m->msg_name);
+	struct sockaddr_tipc *dest = (struct sockaddr_tipc *)m->msg_name;
 	int needs_conn;
-	long timeo;
+	long timeout_val;
 	int res = -EINVAL;
 
 	if (unlikely(!dest))
@@ -647,7 +612,8 @@ static int send_msg(struct kiocb *iocb, struct socket *sock,
 		reject_rx_queue(sk);
 	}
 
-	timeo = sock_sndtimeo(sk, m->msg_flags & MSG_DONTWAIT);
+	timeout_val = sock_sndtimeo(sk, m->msg_flags & MSG_DONTWAIT);
+
 	do {
 		if (dest->addrtype == TIPC_ADDR_NAME) {
 			res = dest_name_check(dest, m);
@@ -656,11 +622,13 @@ static int send_msg(struct kiocb *iocb, struct socket *sock,
 			res = tipc_send2name(tport->ref,
 					     &dest->addr.name.name,
 					     dest->addr.name.domain,
+					     m->msg_iovlen,
 					     m->msg_iov,
 					     total_len);
 		} else if (dest->addrtype == TIPC_ADDR_ID) {
 			res = tipc_send2port(tport->ref,
 					     &dest->addr.id,
+					     m->msg_iovlen,
 					     m->msg_iov,
 					     total_len);
 		} else if (dest->addrtype == TIPC_ADDR_MCAST) {
@@ -673,6 +641,7 @@ static int send_msg(struct kiocb *iocb, struct socket *sock,
 				break;
 			res = tipc_multicast(tport->ref,
 					     &dest->addr.nameseq,
+					     m->msg_iovlen,
 					     m->msg_iov,
 					     total_len);
 		}
@@ -681,9 +650,14 @@ static int send_msg(struct kiocb *iocb, struct socket *sock,
 				sock->state = SS_CONNECTING;
 			break;
 		}
-		res = tipc_wait_for_sndmsg(sock, &timeo);
-		if (res)
+		if (timeout_val <= 0L) {
+			res = timeout_val ? timeout_val : -EWOULDBLOCK;
 			break;
+		}
+		release_sock(sk);
+		timeout_val = wait_event_interruptible_timeout(*sk_sleep(sk),
+					       !tport->congested, timeout_val);
+		lock_sock(sk);
 	} while (1);
 
 exit:
@@ -692,34 +666,6 @@ exit:
 	return res;
 }
 
-static int tipc_wait_for_sndpkt(struct socket *sock, long *timeo_p)
-{
-	struct sock *sk = sock->sk;
-	struct tipc_port *tport = tipc_sk_port(sk);
-	DEFINE_WAIT(wait);
-	int done;
-
-	do {
-		int err = sock_error(sk);
-		if (err)
-			return err;
-		if (sock->state == SS_DISCONNECTING)
-			return -EPIPE;
-		else if (sock->state != SS_CONNECTED)
-			return -ENOTCONN;
-		if (!*timeo_p)
-			return -EAGAIN;
-		if (signal_pending(current))
-			return sock_intr_errno(*timeo_p);
-
-		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
-		done = sk_wait_event(sk, timeo_p,
-				     (!tport->congested || !tport->connected));
-		finish_wait(sk_sleep(sk), &wait);
-	} while (!done);
-	return 0;
-}
-
 /**
  * send_packet - send a connection-oriented message
  * @iocb: if NULL, indicates that socket lock is already held
@@ -736,9 +682,9 @@ static int send_packet(struct kiocb *iocb, struct socket *sock,
 {
 	struct sock *sk = sock->sk;
 	struct tipc_port *tport = tipc_sk_port(sk);
-	DECLARE_SOCKADDR(struct sockaddr_tipc *, dest, m->msg_name);
-	int res = -EINVAL;
-	long timeo;
+	struct sockaddr_tipc *dest = (struct sockaddr_tipc *)m->msg_name;
+	long timeout_val;
+	int res;
 
 	/* Handle implied connection establishment */
 	if (unlikely(dest))
@@ -750,24 +696,31 @@ static int send_packet(struct kiocb *iocb, struct socket *sock,
 	if (iocb)
 		lock_sock(sk);
 
-	if (unlikely(sock->state != SS_CONNECTED)) {
-		if (sock->state == SS_DISCONNECTING)
-			res = -EPIPE;
-		else
-			res = -ENOTCONN;
-		goto exit;
-	}
+	timeout_val = sock_sndtimeo(sk, m->msg_flags & MSG_DONTWAIT);
 
-	timeo = sock_sndtimeo(sk, m->msg_flags & MSG_DONTWAIT);
 	do {
-		res = tipc_send(tport->ref, m->msg_iov, total_len);
+		if (unlikely(sock->state != SS_CONNECTED)) {
+			if (sock->state == SS_DISCONNECTING)
+				res = -EPIPE;
+			else
+				res = -ENOTCONN;
+			break;
+		}
+
+		res = tipc_send(tport->ref, m->msg_iovlen, m->msg_iov,
+				total_len);
 		if (likely(res != -ELINKCONG))
 			break;
-		res = tipc_wait_for_sndpkt(sock, &timeo);
-		if (res)
+		if (timeout_val <= 0L) {
+			res = timeout_val ? timeout_val : -EWOULDBLOCK;
 			break;
+		}
+		release_sock(sk);
+		timeout_val = wait_event_interruptible_timeout(*sk_sleep(sk),
+			(!tport->congested || !tport->connected), timeout_val);
+		lock_sock(sk);
 	} while (1);
-exit:
+
 	if (iocb)
 		release_sock(sk);
 	return res;
@@ -805,11 +758,16 @@ static int send_stream(struct kiocb *iocb, struct socket *sock,
 
 	/* Handle special cases where there is no connection */
 	if (unlikely(sock->state != SS_CONNECTED)) {
-		if (sock->state == SS_UNCONNECTED)
+		if (sock->state == SS_UNCONNECTED) {
 			res = send_packet(NULL, sock, m, total_len);
-		else
-			res = sock->state == SS_DISCONNECTING ? -EPIPE : -ENOTCONN;
-		goto exit;
+			goto exit;
+		} else if (sock->state == SS_DISCONNECTING) {
+			res = -EPIPE;
+			goto exit;
+		} else {
+			res = -ENOTCONN;
+			goto exit;
+		}
 	}
 
 	if (unlikely(m->msg_name)) {
@@ -906,7 +864,7 @@ static int auto_connect(struct socket *sock, struct tipc_msg *msg)
  */
 static void set_orig_addr(struct msghdr *m, struct tipc_msg *msg)
 {
-	DECLARE_SOCKADDR(struct sockaddr_tipc *, addr, m->msg_name);
+	struct sockaddr_tipc *addr = (struct sockaddr_tipc *)m->msg_name;
 
 	if (addr) {
 		addr->family = AF_TIPC;
@@ -991,37 +949,6 @@ static int anc_data_recv(struct msghdr *m, struct tipc_msg *msg,
 	return 0;
 }
 
-static int tipc_wait_for_rcvmsg(struct socket *sock, long timeo)
-{
-	struct sock *sk = sock->sk;
-	DEFINE_WAIT(wait);
-	int err;
-
-	for (;;) {
-		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
-		if (skb_queue_empty(&sk->sk_receive_queue)) {
-			if (sock->state == SS_DISCONNECTING) {
-				err = -ENOTCONN;
-				break;
-			}
-			release_sock(sk);
-			timeo = schedule_timeout(timeo);
-			lock_sock(sk);
-		}
-		err = 0;
-		if (!skb_queue_empty(&sk->sk_receive_queue))
-			break;
-		err = sock_intr_errno(timeo);
-		if (signal_pending(current))
-			break;
-		err = -EAGAIN;
-		if (!timeo)
-			break;
-	}
-	finish_wait(sk_sleep(sk), &wait);
-	return err;
-}
-
 /**
  * recv_msg - receive packet-oriented message
  * @iocb: (unused)
@@ -1041,7 +968,7 @@ static int recv_msg(struct kiocb *iocb, struct socket *sock,
 	struct tipc_port *tport = tipc_sk_port(sk);
 	struct sk_buff *buf;
 	struct tipc_msg *msg;
-	long timeo;
+	long timeout;
 	unsigned int sz;
 	u32 err;
 	int res;
@@ -1057,13 +984,28 @@ static int recv_msg(struct kiocb *iocb, struct socket *sock,
 		goto exit;
 	}
 
-	timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
+	/* will be updated in set_orig_addr() if needed */
+	m->msg_namelen = 0;
+
+	timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
 restart:
 
 	/* Look for a message in receive queue; wait if necessary */
-	res = tipc_wait_for_rcvmsg(sock, timeo);
-	if (res)
-		goto exit;
+	while (skb_queue_empty(&sk->sk_receive_queue)) {
+		if (sock->state == SS_DISCONNECTING) {
+			res = -ENOTCONN;
+			goto exit;
+		}
+		if (timeout <= 0L) {
+			res = timeout ? timeout : -EWOULDBLOCK;
+			goto exit;
+		}
+		release_sock(sk);
+		timeout = wait_event_interruptible_timeout(*sk_sleep(sk),
+							   tipc_rx_ready(sock),
+							   timeout);
+		lock_sock(sk);
+	}
 
 	/* Look at first message in receive queue */
 	buf = skb_peek(&sk->sk_receive_queue);
@@ -1135,7 +1077,7 @@ static int recv_stream(struct kiocb *iocb, struct socket *sock,
 	struct tipc_port *tport = tipc_sk_port(sk);
 	struct sk_buff *buf;
 	struct tipc_msg *msg;
-	long timeo;
+	long timeout;
 	unsigned int sz;
 	int sz_to_copy, target, needed;
 	int sz_copied = 0;
@@ -1148,19 +1090,34 @@ static int recv_stream(struct kiocb *iocb, struct socket *sock,
 
 	lock_sock(sk);
 
-	if (unlikely(sock->state == SS_UNCONNECTED)) {
+	if (unlikely((sock->state == SS_UNCONNECTED))) {
 		res = -ENOTCONN;
 		goto exit;
 	}
 
+	/* will be updated in set_orig_addr() if needed */
+	m->msg_namelen = 0;
+
 	target = sock_rcvlowat(sk, flags & MSG_WAITALL, buf_len);
-	timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
+	timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
 
 restart:
 	/* Look for a message in receive queue; wait if necessary */
-	res = tipc_wait_for_rcvmsg(sock, timeo);
-	if (res)
-		goto exit;
+	while (skb_queue_empty(&sk->sk_receive_queue)) {
+		if (sock->state == SS_DISCONNECTING) {
+			res = -ENOTCONN;
+			goto exit;
+		}
+		if (timeout <= 0L) {
+			res = timeout ? timeout : -EWOULDBLOCK;
+			goto exit;
+		}
+		release_sock(sk);
+		timeout = wait_event_interruptible_timeout(*sk_sleep(sk),
+							   tipc_rx_ready(sock),
+							   timeout);
+		lock_sock(sk);
+	}
 
 	/* Look at first message in receive queue */
 	buf = skb_peek(&sk->sk_receive_queue);
@@ -1364,12 +1321,14 @@ static u32 filter_connect(struct tipc_sock *tsock, struct sk_buff **buf)
 static unsigned int rcvbuf_limit(struct sock *sk, struct sk_buff *buf)
 {
 	struct tipc_msg *msg = buf_msg(buf);
+	unsigned int limit;
 
 	if (msg_connected(msg))
-		return sysctl_tipc_rmem[2];
-
-	return sk->sk_rcvbuf >> TIPC_CRITICAL_IMPORTANCE <<
-		msg_importance(msg);
+		limit = sysctl_tipc_rmem[2];
+	else
+		limit = sk->sk_rcvbuf >> TIPC_CRITICAL_IMPORTANCE <<
+			msg_importance(msg);
+	return limit;
 }
 
 /**
@@ -1409,7 +1368,7 @@ static u32 filter_rcv(struct sock *sk, struct sk_buff *buf)
 		return TIPC_ERR_OVERLOAD;
 
 	/* Enqueue message */
-	TIPC_SKB_CB(buf)->handle = NULL;
+	TIPC_SKB_CB(buf)->handle = 0;
 	__skb_queue_tail(&sk->sk_receive_queue, buf);
 	skb_set_owner_r(buf, sk);
 
@@ -1483,28 +1442,6 @@ static void wakeupdispatch(struct tipc_port *tport)
 	sk->sk_write_space(sk);
 }
 
-static int tipc_wait_for_connect(struct socket *sock, long *timeo_p)
-{
-	struct sock *sk = sock->sk;
-	DEFINE_WAIT(wait);
-	int done;
-
-	do {
-		int err = sock_error(sk);
-		if (err)
-			return err;
-		if (!*timeo_p)
-			return -ETIMEDOUT;
-		if (signal_pending(current))
-			return sock_intr_errno(*timeo_p);
-
-		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
-		done = sk_wait_event(sk, timeo_p, sock->state != SS_CONNECTING);
-		finish_wait(sk_sleep(sk), &wait);
-	} while (!done);
-	return 0;
-}
-
 /**
  * connect - establish a connection to another TIPC port
  * @sock: socket structure
@@ -1520,8 +1457,7 @@ static int connect(struct socket *sock, struct sockaddr *dest, int destlen,
 	struct sock *sk = sock->sk;
 	struct sockaddr_tipc *dst = (struct sockaddr_tipc *)dest;
 	struct msghdr m = {NULL,};
-	long timeout = (flags & O_NONBLOCK) ? 0 : tipc_sk(sk)->conn_timeout;
-	socket_state previous;
+	unsigned int timeout;
 	int res;
 
 	lock_sock(sk);
@@ -1543,7 +1479,8 @@ static int connect(struct socket *sock, struct sockaddr *dest, int destlen,
 		goto exit;
 	}
 
-	previous = sock->state;
+	timeout = (flags & O_NONBLOCK) ? 0 : tipc_sk(sk)->conn_timeout;
+
 	switch (sock->state) {
 	case SS_UNCONNECTED:
 		/* Send a 'SYN-' to destination */
@@ -1565,22 +1502,43 @@ static int connect(struct socket *sock, struct sockaddr *dest, int destlen,
 		 * case is EINPROGRESS, rather than EALREADY.
 		 */
 		res = -EINPROGRESS;
+		break;
 	case SS_CONNECTING:
-		if (previous == SS_CONNECTING)
-			res = -EALREADY;
-		if (!timeout)
-			goto exit;
-		timeout = msecs_to_jiffies(timeout);
-		/* Wait until an 'ACK' or 'RST' arrives, or a timeout occurs */
-		res = tipc_wait_for_connect(sock, &timeout);
+		res = -EALREADY;
 		break;
 	case SS_CONNECTED:
 		res = -EISCONN;
 		break;
 	default:
 		res = -EINVAL;
-		break;
+		goto exit;
+	}
+
+	if (sock->state == SS_CONNECTING) {
+		if (!timeout)
+			goto exit;
+
+		/* Wait until an 'ACK' or 'RST' arrives, or a timeout occurs */
+		release_sock(sk);
+		res = wait_event_interruptible_timeout(*sk_sleep(sk),
+				sock->state != SS_CONNECTING,
+				timeout ? (long)msecs_to_jiffies(timeout)
+					: MAX_SCHEDULE_TIMEOUT);
+		lock_sock(sk);
+		if (res <= 0) {
+			if (res == 0)
+				res = -ETIMEDOUT;
+			else
+				; /* leave "res" unchanged */
+			goto exit;
+		}
 	}
+
+	if (unlikely(sock->state == SS_DISCONNECTING))
+		res = sock_error(sk);
+	else
+		res = 0;
+
 exit:
 	release_sock(sk);
 	return res;
@@ -1611,42 +1569,6 @@ static int listen(struct socket *sock, int len)
 	return res;
 }
 
-static int tipc_wait_for_accept(struct socket *sock, long timeo)
-{
-	struct sock *sk = sock->sk;
-	DEFINE_WAIT(wait);
-	int err;
-
-	/* True wake-one mechanism for incoming connections: only
-	 * one process gets woken up, not the 'whole herd'.
-	 * Since we do not 'race & poll' for established sockets
-	 * anymore, the common case will execute the loop only once.
-	*/
-	for (;;) {
-		prepare_to_wait_exclusive(sk_sleep(sk), &wait,
-					  TASK_INTERRUPTIBLE);
-		if (skb_queue_empty(&sk->sk_receive_queue)) {
-			release_sock(sk);
-			timeo = schedule_timeout(timeo);
-			lock_sock(sk);
-		}
-		err = 0;
-		if (!skb_queue_empty(&sk->sk_receive_queue))
-			break;
-		err = -EINVAL;
-		if (sock->state != SS_LISTENING)
-			break;
-		err = sock_intr_errno(timeo);
-		if (signal_pending(current))
-			break;
-		err = -EAGAIN;
-		if (!timeo)
-			break;
-	}
-	finish_wait(sk_sleep(sk), &wait);
-	return err;
-}
-
 /**
  * accept - wait for connection request
  * @sock: listening socket
@@ -1663,7 +1585,7 @@ static int accept(struct socket *sock, struct socket *new_sock, int flags)
 	struct tipc_port *new_tport;
 	struct tipc_msg *msg;
 	u32 new_ref;
-	long timeo;
+
 	int res;
 
 	lock_sock(sk);
@@ -1673,10 +1595,18 @@ static int accept(struct socket *sock, struct socket *new_sock, int flags)
 		goto exit;
 	}
 
-	timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
-	res = tipc_wait_for_accept(sock, timeo);
-	if (res)
-		goto exit;
+	while (skb_queue_empty(&sk->sk_receive_queue)) {
+		if (flags & O_NONBLOCK) {
+			res = -EWOULDBLOCK;
+			goto exit;
+		}
+		release_sock(sk);
+		res = wait_event_interruptible(*sk_sleep(sk),
+				(!skb_queue_empty(&sk->sk_receive_queue)));
+		lock_sock(sk);
+		if (res)
+			goto exit;
+	}
 
 	buf = skb_peek(&sk->sk_receive_queue);
 
@@ -1761,7 +1691,7 @@ 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 != NULL) {
+			if (TIPC_SKB_CB(buf)->handle != 0) {
 				kfree_skb(buf);
 				goto restart;
 			}