52  *		other the moment one end closes.
464 static int unix_dgram_peer_wake_connect(struct sock *sk, struct sock *other)  in unix_dgram_peer_wake_connect()  argument
470 	u_other = unix_sk(other);  in unix_dgram_peer_wake_connect()
475 		u->peer_wake.private = other;  in unix_dgram_peer_wake_connect()
486 					    struct sock *other)  in unix_dgram_peer_wake_disconnect()  argument
491 	u_other = unix_sk(other);  in unix_dgram_peer_wake_disconnect()
494 	if (u->peer_wake.private == other) {  in unix_dgram_peer_wake_disconnect()
503 						   struct sock *other)  in unix_dgram_peer_wake_disconnect_wakeup()  argument
505 	unix_dgram_peer_wake_disconnect(sk, other);  in unix_dgram_peer_wake_disconnect_wakeup()
513  *	- unix_peer(sk) == other
516 static int unix_dgram_peer_wake_me(struct sock *sk, struct sock *other)  in unix_dgram_peer_wake_me()  argument
520 	connected = unix_dgram_peer_wake_connect(sk, other);  in unix_dgram_peer_wake_me()
522 	/* If other is SOCK_DEAD, we want to make sure we signal  in unix_dgram_peer_wake_me()
525 	 * to other and its full, we will hang waiting for POLLOUT.  in unix_dgram_peer_wake_me()
527 	if (unix_recvq_full_lockless(other) && !sock_flag(other, SOCK_DEAD))  in unix_dgram_peer_wake_me()
531 		unix_dgram_peer_wake_disconnect(sk, other);  in unix_dgram_peer_wake_me()
561 static void unix_dgram_disconnected(struct sock *sk, struct sock *other)  in unix_dgram_disconnected()  argument
571 		if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) {  in unix_dgram_disconnected()
572 			WRITE_ONCE(other->sk_err, ECONNRESET);  in unix_dgram_disconnected()
573 			sk_error_report(other);  in unix_dgram_disconnected()
576 	other->sk_state = TCP_CLOSE;  in unix_dgram_disconnected()
1372 	struct sock *other;  in unix_dgram_connect()  local
1393 		other = unix_find_other(sock_net(sk), sunaddr, alen, sock->type);  in unix_dgram_connect()
1394 		if (IS_ERR(other)) {  in unix_dgram_connect()
1395 			err = PTR_ERR(other);  in unix_dgram_connect()
1399 		unix_state_double_lock(sk, other);  in unix_dgram_connect()
1402 		if (sock_flag(other, SOCK_DEAD)) {  in unix_dgram_connect()
1403 			unix_state_double_unlock(sk, other);  in unix_dgram_connect()
1404 			sock_put(other);  in unix_dgram_connect()
1409 		if (!unix_may_send(sk, other))  in unix_dgram_connect()
1412 		err = security_unix_may_send(sk->sk_socket, other->sk_socket);  in unix_dgram_connect()
1416 		sk->sk_state = other->sk_state = TCP_ESTABLISHED;  in unix_dgram_connect()
1421 		other = NULL;  in unix_dgram_connect()
1422 		unix_state_double_lock(sk, other);  in unix_dgram_connect()
1431 		unix_peer(sk) = other;  in unix_dgram_connect()
1432 		if (!other)  in unix_dgram_connect()
1436 		unix_state_double_unlock(sk, other);  in unix_dgram_connect()
1438 		if (other != old_peer)  in unix_dgram_connect()
1442 		unix_peer(sk) = other;  in unix_dgram_connect()
1443 		unix_state_double_unlock(sk, other);  in unix_dgram_connect()
1449 	unix_state_double_unlock(sk, other);  in unix_dgram_connect()
1450 	sock_put(other);  in unix_dgram_connect()
1455 static long unix_wait_for_peer(struct sock *other, long timeo)  in unix_wait_for_peer()  argument
1456 	__releases(&unix_sk(other)->lock)  in unix_wait_for_peer()
1458 	struct unix_sock *u = unix_sk(other);  in unix_wait_for_peer()
1464 	sched = !sock_flag(other, SOCK_DEAD) &&  in unix_wait_for_peer()
1465 		!(other->sk_shutdown & RCV_SHUTDOWN) &&  in unix_wait_for_peer()
1466 		unix_recvq_full_lockless(other);  in unix_wait_for_peer()
1468 	unix_state_unlock(other);  in unix_wait_for_peer()
1481 	struct sock *sk = sock->sk, *newsk = NULL, *other = NULL;  in unix_stream_connect()  local
1524 	other = unix_find_other(net, sunaddr, addr_len, sk->sk_type);  in unix_stream_connect()
1525 	if (IS_ERR(other)) {  in unix_stream_connect()
1526 		err = PTR_ERR(other);  in unix_stream_connect()
1527 		other = NULL;  in unix_stream_connect()
1532 	unix_state_lock(other);  in unix_stream_connect()
1535 	if (sock_flag(other, SOCK_DEAD)) {  in unix_stream_connect()
1536 		unix_state_unlock(other);  in unix_stream_connect()
1537 		sock_put(other);  in unix_stream_connect()
1542 	if (other->sk_state != TCP_LISTEN)  in unix_stream_connect()
1544 	if (other->sk_shutdown & RCV_SHUTDOWN)  in unix_stream_connect()
1547 	if (unix_recvq_full(other)) {  in unix_stream_connect()
1552 		timeo = unix_wait_for_peer(other, timeo);  in unix_stream_connect()
1557 		sock_put(other);  in unix_stream_connect()
1567 	   state. other is TCP_LISTEN, if sk is TCP_LISTEN we  in unix_stream_connect()
1591 		unix_state_unlock(other);  in unix_stream_connect()
1592 		sock_put(other);  in unix_stream_connect()
1596 	err = security_unix_stream_connect(sk, other, newsk);  in unix_stream_connect()
1611 	otheru = unix_sk(other);  in unix_stream_connect()
1638 	copy_peercred(sk, other);  in unix_stream_connect()
1650 	spin_lock(&other->sk_receive_queue.lock);  in unix_stream_connect()
1651 	__skb_queue_tail(&other->sk_receive_queue, skb);  in unix_stream_connect()
1652 	spin_unlock(&other->sk_receive_queue.lock);  in unix_stream_connect()
1653 	unix_state_unlock(other);  in unix_stream_connect()
1654 	other->sk_data_ready(other);  in unix_stream_connect()
1655 	sock_put(other);  in unix_stream_connect()
1659 	if (other)  in unix_stream_connect()
1660 		unix_state_unlock(other);  in unix_stream_connect()
1666 	if (other)  in unix_stream_connect()
1667 		sock_put(other);  in unix_stream_connect()
1843 				  const struct sock *other)  in unix_passcred_enabled()  argument
1847 	       !other->sk_socket ||  in unix_passcred_enabled()
1848 	       test_bit(SOCK_PASSCRED, &other->sk_socket->flags) ||  in unix_passcred_enabled()
1849 	       test_bit(SOCK_PASSPIDFD, &other->sk_socket->flags);  in unix_passcred_enabled()
1858 			    const struct sock *other)  in maybe_add_creds()  argument
1862 	if (unix_passcred_enabled(sock, other)) {  in maybe_add_creds()
1903 	struct sock *sk = sock->sk, *other = NULL;  in unix_dgram_sendmsg()  local
1928 		other = unix_peer_get(sk);  in unix_dgram_sendmsg()
1929 		if (!other)  in unix_dgram_sendmsg()
1973 	if (!other) {  in unix_dgram_sendmsg()
1978 		other = unix_find_other(sock_net(sk), sunaddr, msg->msg_namelen,  in unix_dgram_sendmsg()
1980 		if (IS_ERR(other)) {  in unix_dgram_sendmsg()
1981 			err = PTR_ERR(other);  in unix_dgram_sendmsg()
1982 			other = NULL;  in unix_dgram_sendmsg()
1987 	if (sk_filter(other, skb) < 0) {  in unix_dgram_sendmsg()
1994 	unix_state_lock(other);  in unix_dgram_sendmsg()
1997 	if (!unix_may_send(sk, other))  in unix_dgram_sendmsg()
2000 	if (unlikely(sock_flag(other, SOCK_DEAD))) {  in unix_dgram_sendmsg()
2005 		unix_state_unlock(other);  in unix_dgram_sendmsg()
2006 		sock_put(other);  in unix_dgram_sendmsg()
2014 			 * is clearing @other. Never change state to TCP_CLOSE  in unix_dgram_sendmsg()
2019 		} else if (unix_peer(sk) == other) {  in unix_dgram_sendmsg()
2021 			unix_dgram_peer_wake_disconnect_wakeup(sk, other);  in unix_dgram_sendmsg()
2026 			unix_dgram_disconnected(sk, other);  in unix_dgram_sendmsg()
2027 			sock_put(other);  in unix_dgram_sendmsg()
2033 		other = NULL;  in unix_dgram_sendmsg()
2040 	if (other->sk_shutdown & RCV_SHUTDOWN)  in unix_dgram_sendmsg()
2044 		err = security_unix_may_send(sk->sk_socket, other->sk_socket);  in unix_dgram_sendmsg()
2049 	/* other == sk && unix_peer(other) != sk if  in unix_dgram_sendmsg()
2053 	if (other != sk &&  in unix_dgram_sendmsg()
2054 	    unlikely(unix_peer(other) != sk &&  in unix_dgram_sendmsg()
2055 	    unix_recvq_full_lockless(other))) {  in unix_dgram_sendmsg()
2057 			timeo = unix_wait_for_peer(other, timeo);  in unix_dgram_sendmsg()
2067 			unix_state_unlock(other);  in unix_dgram_sendmsg()
2068 			unix_state_double_lock(sk, other);  in unix_dgram_sendmsg()
2071 		if (unix_peer(sk) != other ||  in unix_dgram_sendmsg()
2072 		    unix_dgram_peer_wake_me(sk, other)) {  in unix_dgram_sendmsg()
2087 	if (sock_flag(other, SOCK_RCVTSTAMP))  in unix_dgram_sendmsg()
2089 	maybe_add_creds(skb, sock, other);  in unix_dgram_sendmsg()
2090 	scm_stat_add(other, skb);  in unix_dgram_sendmsg()
2091 	skb_queue_tail(&other->sk_receive_queue, skb);  in unix_dgram_sendmsg()
2092 	unix_state_unlock(other);  in unix_dgram_sendmsg()
2093 	other->sk_data_ready(other);  in unix_dgram_sendmsg()
2094 	sock_put(other);  in unix_dgram_sendmsg()
2101 	unix_state_unlock(other);  in unix_dgram_sendmsg()
2105 	if (other)  in unix_dgram_sendmsg()
2106 		sock_put(other);  in unix_dgram_sendmsg()
2117 static int queue_oob(struct socket *sock, struct msghdr *msg, struct sock *other,  in queue_oob()  argument
2120 	struct unix_sock *ousk = unix_sk(other);  in queue_oob()
2142 	unix_state_lock(other);  in queue_oob()
2144 	if (sock_flag(other, SOCK_DEAD) ||  in queue_oob()
2145 	    (other->sk_shutdown & RCV_SHUTDOWN)) {  in queue_oob()
2146 		unix_state_unlock(other);  in queue_oob()
2151 	maybe_add_creds(skb, sock, other);  in queue_oob()
2159 	scm_stat_add(other, skb);  in queue_oob()
2160 	skb_queue_tail(&other->sk_receive_queue, skb);  in queue_oob()
2161 	sk_send_sigurg(other);  in queue_oob()
2162 	unix_state_unlock(other);  in queue_oob()
2163 	other->sk_data_ready(other);  in queue_oob()
2173 	struct sock *other = NULL;  in unix_stream_sendmsg()  local
2201 		other = unix_peer(sk);  in unix_stream_sendmsg()
2202 		if (!other)  in unix_stream_sendmsg()
2262 		unix_state_lock(other);  in unix_stream_sendmsg()
2264 		if (sock_flag(other, SOCK_DEAD) ||  in unix_stream_sendmsg()
2265 		    (other->sk_shutdown & RCV_SHUTDOWN))  in unix_stream_sendmsg()
2268 		maybe_add_creds(skb, sock, other);  in unix_stream_sendmsg()
2269 		scm_stat_add(other, skb);  in unix_stream_sendmsg()
2270 		skb_queue_tail(&other->sk_receive_queue, skb);  in unix_stream_sendmsg()
2271 		unix_state_unlock(other);  in unix_stream_sendmsg()
2272 		other->sk_data_ready(other);  in unix_stream_sendmsg()
2278 		err = queue_oob(sock, msg, other, &scm, fds_sent);  in unix_stream_sendmsg()
2290 	unix_state_unlock(other);  in unix_stream_sendmsg()
2907 	struct sock *other;  in unix_shutdown()  local
2920 	other = unix_peer(sk);  in unix_shutdown()
2921 	if (other)  in unix_shutdown()
2922 		sock_hold(other);  in unix_shutdown()
2926 	if (other &&  in unix_shutdown()
2930 		const struct proto *prot = READ_ONCE(other->sk_prot);  in unix_shutdown()
2933 			prot->unhash(other);  in unix_shutdown()
2938 		unix_state_lock(other);  in unix_shutdown()
2939 		WRITE_ONCE(other->sk_shutdown, other->sk_shutdown | peer_mode);  in unix_shutdown()
2940 		unix_state_unlock(other);  in unix_shutdown()
2941 		other->sk_state_change(other);  in unix_shutdown()
2943 			sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP);  in unix_shutdown()
2945 			sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN);  in unix_shutdown()
2947 	if (other)  in unix_shutdown()
2948 		sock_put(other);  in unix_shutdown()
3101 	 * we set writable also when the other side has shut down the  in unix_poll()
3113 	struct sock *sk = sock->sk, *other;  in unix_dgram_poll()  local
3156 		other = unix_peer(sk);  in unix_dgram_poll()
3157 		if (other && unix_peer(other) != sk &&  in unix_dgram_poll()
3158 		    unix_recvq_full_lockless(other) &&  in unix_dgram_poll()
3159 		    unix_dgram_peer_wake_me(sk, other))  in unix_dgram_poll()
3692 /* Earlier than device_initcall() so that other drivers invoking