52  *		other the moment one end closes.
525 static int unix_dgram_peer_wake_connect(struct sock *sk, struct sock *other)  in unix_dgram_peer_wake_connect()  argument
531 	u_other = unix_sk(other);  in unix_dgram_peer_wake_connect()
536 		u->peer_wake.private = other;  in unix_dgram_peer_wake_connect()
547 					    struct sock *other)  in unix_dgram_peer_wake_disconnect()  argument
552 	u_other = unix_sk(other);  in unix_dgram_peer_wake_disconnect()
555 	if (u->peer_wake.private == other) {  in unix_dgram_peer_wake_disconnect()
564 						   struct sock *other)  in unix_dgram_peer_wake_disconnect_wakeup()  argument
566 	unix_dgram_peer_wake_disconnect(sk, other);  in unix_dgram_peer_wake_disconnect_wakeup()
574  *	- unix_peer(sk) == other
577 static int unix_dgram_peer_wake_me(struct sock *sk, struct sock *other)  in unix_dgram_peer_wake_me()  argument
581 	connected = unix_dgram_peer_wake_connect(sk, other);  in unix_dgram_peer_wake_me()
583 	/* If other is SOCK_DEAD, we want to make sure we signal  in unix_dgram_peer_wake_me()
586 	 * to other and its full, we will hang waiting for POLLOUT.  in unix_dgram_peer_wake_me()
588 	if (unix_recvq_full_lockless(other) && !sock_flag(other, SOCK_DEAD))  in unix_dgram_peer_wake_me()
592 		unix_dgram_peer_wake_disconnect(sk, other);  in unix_dgram_peer_wake_me()
622 static void unix_dgram_disconnected(struct sock *sk, struct sock *other)  in unix_dgram_disconnected()  argument
634 		if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) {  in unix_dgram_disconnected()
635 			WRITE_ONCE(other->sk_err, ECONNRESET);  in unix_dgram_disconnected()
636 			sk_error_report(other);  in unix_dgram_disconnected()
1415 	struct sock *other;  in unix_dgram_connect()  local
1440 		other = unix_find_other(sock_net(sk), sunaddr, alen, sock->type);  in unix_dgram_connect()
1441 		if (IS_ERR(other)) {  in unix_dgram_connect()
1442 			err = PTR_ERR(other);  in unix_dgram_connect()
1446 		unix_state_double_lock(sk, other);  in unix_dgram_connect()
1449 		if (sock_flag(other, SOCK_DEAD)) {  in unix_dgram_connect()
1450 			unix_state_double_unlock(sk, other);  in unix_dgram_connect()
1451 			sock_put(other);  in unix_dgram_connect()
1456 		if (!unix_may_send(sk, other))  in unix_dgram_connect()
1459 		err = security_unix_may_send(sk->sk_socket, other->sk_socket);  in unix_dgram_connect()
1464 		WRITE_ONCE(other->sk_state, TCP_ESTABLISHED);  in unix_dgram_connect()
1469 		other = NULL;  in unix_dgram_connect()
1470 		unix_state_double_lock(sk, other);  in unix_dgram_connect()
1479 		unix_peer(sk) = other;  in unix_dgram_connect()
1480 		if (!other)  in unix_dgram_connect()
1484 		unix_state_double_unlock(sk, other);  in unix_dgram_connect()
1486 		if (other != old_peer) {  in unix_dgram_connect()
1497 		unix_peer(sk) = other;  in unix_dgram_connect()
1498 		unix_state_double_unlock(sk, other);  in unix_dgram_connect()
1504 	unix_state_double_unlock(sk, other);  in unix_dgram_connect()
1505 	sock_put(other);  in unix_dgram_connect()
1510 static long unix_wait_for_peer(struct sock *other, long timeo)  in unix_wait_for_peer()  argument
1511 	__releases(&unix_sk(other)->lock)  in unix_wait_for_peer()
1513 	struct unix_sock *u = unix_sk(other);  in unix_wait_for_peer()
1519 	sched = !sock_flag(other, SOCK_DEAD) &&  in unix_wait_for_peer()
1520 		!(other->sk_shutdown & RCV_SHUTDOWN) &&  in unix_wait_for_peer()
1521 		unix_recvq_full_lockless(other);  in unix_wait_for_peer()
1523 	unix_state_unlock(other);  in unix_wait_for_peer()
1536 	struct sock *sk = sock->sk, *newsk = NULL, *other = NULL;  in unix_stream_connect()  local
1583 	other = unix_find_other(net, sunaddr, addr_len, sk->sk_type);  in unix_stream_connect()
1584 	if (IS_ERR(other)) {  in unix_stream_connect()
1585 		err = PTR_ERR(other);  in unix_stream_connect()
1589 	unix_state_lock(other);  in unix_stream_connect()
1592 	if (sock_flag(other, SOCK_DEAD)) {  in unix_stream_connect()
1593 		unix_state_unlock(other);  in unix_stream_connect()
1594 		sock_put(other);  in unix_stream_connect()
1598 	if (other->sk_state != TCP_LISTEN ||  in unix_stream_connect()
1599 	    other->sk_shutdown & RCV_SHUTDOWN) {  in unix_stream_connect()
1604 	if (unix_recvq_full_lockless(other)) {  in unix_stream_connect()
1610 		timeo = unix_wait_for_peer(other, timeo);  in unix_stream_connect()
1611 		sock_put(other);  in unix_stream_connect()
1637 	err = security_unix_stream_connect(sk, other, newsk);  in unix_stream_connect()
1651 	newu->listener = other;  in unix_stream_connect()
1653 	otheru = unix_sk(other);  in unix_stream_connect()
1680 	copy_peercred(sk, other);  in unix_stream_connect()
1692 	spin_lock(&other->sk_receive_queue.lock);  in unix_stream_connect()
1693 	__skb_queue_tail(&other->sk_receive_queue, skb);  in unix_stream_connect()
1694 	spin_unlock(&other->sk_receive_queue.lock);  in unix_stream_connect()
1695 	unix_state_unlock(other);  in unix_stream_connect()
1696 	other->sk_data_ready(other);  in unix_stream_connect()
1697 	sock_put(other);  in unix_stream_connect()
1701 	unix_state_unlock(other);  in unix_stream_connect()
1702 	sock_put(other);  in unix_stream_connect()
1899 				  const struct sock *other)  in unix_passcred_enabled()  argument
1903 	       !other->sk_socket ||  in unix_passcred_enabled()
1904 	       test_bit(SOCK_PASSCRED, &other->sk_socket->flags) ||  in unix_passcred_enabled()
1905 	       test_bit(SOCK_PASSPIDFD, &other->sk_socket->flags);  in unix_passcred_enabled()
1914 			    const struct sock *other)  in maybe_add_creds()  argument
1918 	if (unix_passcred_enabled(sock, other)) {  in maybe_add_creds()
1962 	struct sock *sk = sock->sk, *other = NULL;  in unix_dgram_sendmsg()  local
2038 		other = unix_find_other(sock_net(sk), msg->msg_name,  in unix_dgram_sendmsg()
2040 		if (IS_ERR(other)) {  in unix_dgram_sendmsg()
2041 			err = PTR_ERR(other);  in unix_dgram_sendmsg()
2045 		other = unix_peer_get(sk);  in unix_dgram_sendmsg()
2046 		if (!other) {  in unix_dgram_sendmsg()
2052 	if (sk_filter(other, skb) < 0) {  in unix_dgram_sendmsg()
2060 	unix_state_lock(other);  in unix_dgram_sendmsg()
2063 	if (!unix_may_send(sk, other)) {  in unix_dgram_sendmsg()
2068 	if (unlikely(sock_flag(other, SOCK_DEAD))) {  in unix_dgram_sendmsg()
2071 		unix_state_unlock(other);  in unix_dgram_sendmsg()
2075 			 * is clearing @other. Never change state to TCP_CLOSE  in unix_dgram_sendmsg()
2085 		if (unix_peer(sk) == other) {  in unix_dgram_sendmsg()
2087 			unix_dgram_peer_wake_disconnect_wakeup(sk, other);  in unix_dgram_sendmsg()
2092 			unix_dgram_disconnected(sk, other);  in unix_dgram_sendmsg()
2093 			sock_put(other);  in unix_dgram_sendmsg()
2105 		sock_put(other);  in unix_dgram_sendmsg()
2109 	if (other->sk_shutdown & RCV_SHUTDOWN) {  in unix_dgram_sendmsg()
2115 		err = security_unix_may_send(sk->sk_socket, other->sk_socket);  in unix_dgram_sendmsg()
2120 	/* other == sk && unix_peer(other) != sk if  in unix_dgram_sendmsg()
2124 	if (other != sk &&  in unix_dgram_sendmsg()
2125 	    unlikely(unix_peer(other) != sk &&  in unix_dgram_sendmsg()
2126 	    unix_recvq_full_lockless(other))) {  in unix_dgram_sendmsg()
2128 			timeo = unix_wait_for_peer(other, timeo);  in unix_dgram_sendmsg()
2138 			unix_state_unlock(other);  in unix_dgram_sendmsg()
2139 			unix_state_double_lock(sk, other);  in unix_dgram_sendmsg()
2142 		if (unix_peer(sk) != other ||  in unix_dgram_sendmsg()
2143 		    unix_dgram_peer_wake_me(sk, other)) {  in unix_dgram_sendmsg()
2158 	if (sock_flag(other, SOCK_RCVTSTAMP))  in unix_dgram_sendmsg()
2160 	maybe_add_creds(skb, sock, other);  in unix_dgram_sendmsg()
2161 	scm_stat_add(other, skb);  in unix_dgram_sendmsg()
2162 	skb_queue_tail(&other->sk_receive_queue, skb);  in unix_dgram_sendmsg()
2163 	unix_state_unlock(other);  in unix_dgram_sendmsg()
2164 	other->sk_data_ready(other);  in unix_dgram_sendmsg()
2165 	sock_put(other);  in unix_dgram_sendmsg()
2172 	unix_state_unlock(other);  in unix_dgram_sendmsg()
2174 	sock_put(other);  in unix_dgram_sendmsg()
2188 static int queue_oob(struct socket *sock, struct msghdr *msg, struct sock *other,  in queue_oob()  argument
2191 	struct unix_sock *ousk = unix_sk(other);  in queue_oob()
2210 	unix_state_lock(other);  in queue_oob()
2212 	if (sock_flag(other, SOCK_DEAD) ||  in queue_oob()
2213 	    (other->sk_shutdown & RCV_SHUTDOWN)) {  in queue_oob()
2214 		unix_state_unlock(other);  in queue_oob()
2219 	maybe_add_creds(skb, sock, other);  in queue_oob()
2220 	scm_stat_add(other, skb);  in queue_oob()
2222 	spin_lock(&other->sk_receive_queue.lock);  in queue_oob()
2224 	__skb_queue_tail(&other->sk_receive_queue, skb);  in queue_oob()
2225 	spin_unlock(&other->sk_receive_queue.lock);  in queue_oob()
2227 	sk_send_sigurg(other);  in queue_oob()
2228 	unix_state_unlock(other);  in queue_oob()
2229 	other->sk_data_ready(other);  in queue_oob()
2243 	struct sock *other = NULL;  in unix_stream_sendmsg()  local
2268 		other = unix_peer(sk);  in unix_stream_sendmsg()
2269 		if (!other) {  in unix_stream_sendmsg()
2329 		unix_state_lock(other);  in unix_stream_sendmsg()
2331 		if (sock_flag(other, SOCK_DEAD) ||  in unix_stream_sendmsg()
2332 		    (other->sk_shutdown & RCV_SHUTDOWN))  in unix_stream_sendmsg()
2335 		maybe_add_creds(skb, sock, other);  in unix_stream_sendmsg()
2336 		scm_stat_add(other, skb);  in unix_stream_sendmsg()
2337 		skb_queue_tail(&other->sk_receive_queue, skb);  in unix_stream_sendmsg()
2338 		unix_state_unlock(other);  in unix_stream_sendmsg()
2339 		other->sk_data_ready(other);  in unix_stream_sendmsg()
2345 		err = queue_oob(sock, msg, other, &scm, fds_sent);  in unix_stream_sendmsg()
2357 	unix_state_unlock(other);  in unix_stream_sendmsg()
3029 	struct sock *other;  in unix_shutdown()  local
3042 	other = unix_peer(sk);  in unix_shutdown()
3043 	if (other)  in unix_shutdown()
3044 		sock_hold(other);  in unix_shutdown()
3048 	if (other &&  in unix_shutdown()
3052 		const struct proto *prot = READ_ONCE(other->sk_prot);  in unix_shutdown()
3055 			prot->unhash(other);  in unix_shutdown()
3060 		unix_state_lock(other);  in unix_shutdown()
3061 		WRITE_ONCE(other->sk_shutdown, other->sk_shutdown | peer_mode);  in unix_shutdown()
3062 		unix_state_unlock(other);  in unix_shutdown()
3063 		other->sk_state_change(other);  in unix_shutdown()
3065 			sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP);  in unix_shutdown()
3067 			sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN);  in unix_shutdown()
3069 	if (other)  in unix_shutdown()
3070 		sock_put(other);  in unix_shutdown()
3240 	 * we set writable also when the other side has shut down the  in unix_poll()
3252 	struct sock *sk = sock->sk, *other;  in unix_dgram_poll()  local
3292 		other = unix_peer(sk);  in unix_dgram_poll()
3293 		if (other && unix_peer(other) != sk &&  in unix_dgram_poll()
3294 		    unix_recvq_full_lockless(other) &&  in unix_dgram_poll()
3295 		    unix_dgram_peer_wake_me(sk, other))  in unix_dgram_poll()