52  *		other the moment one end closes.
519 static int unix_dgram_peer_wake_connect(struct sock *sk, struct sock *other)  in unix_dgram_peer_wake_connect()  argument
525 	u_other = unix_sk(other);  in unix_dgram_peer_wake_connect()
530 		u->peer_wake.private = other;  in unix_dgram_peer_wake_connect()
541 					    struct sock *other)  in unix_dgram_peer_wake_disconnect()  argument
546 	u_other = unix_sk(other);  in unix_dgram_peer_wake_disconnect()
549 	if (u->peer_wake.private == other) {  in unix_dgram_peer_wake_disconnect()
558 						   struct sock *other)  in unix_dgram_peer_wake_disconnect_wakeup()  argument
560 	unix_dgram_peer_wake_disconnect(sk, other);  in unix_dgram_peer_wake_disconnect_wakeup()
568  *	- unix_peer(sk) == other
571 static int unix_dgram_peer_wake_me(struct sock *sk, struct sock *other)  in unix_dgram_peer_wake_me()  argument
575 	connected = unix_dgram_peer_wake_connect(sk, other);  in unix_dgram_peer_wake_me()
577 	/* If other is SOCK_DEAD, we want to make sure we signal  in unix_dgram_peer_wake_me()
580 	 * to other and its full, we will hang waiting for POLLOUT.  in unix_dgram_peer_wake_me()
582 	if (unix_recvq_full_lockless(other) && !sock_flag(other, SOCK_DEAD))  in unix_dgram_peer_wake_me()
586 		unix_dgram_peer_wake_disconnect(sk, other);  in unix_dgram_peer_wake_me()
616 static void unix_dgram_disconnected(struct sock *sk, struct sock *other)  in unix_dgram_disconnected()  argument
628 		if (!sock_flag(other, SOCK_DEAD) && unix_peer(other) == sk) {  in unix_dgram_disconnected()
629 			WRITE_ONCE(other->sk_err, ECONNRESET);  in unix_dgram_disconnected()
630 			sk_error_report(other);  in unix_dgram_disconnected()
1531 	struct sock *other;  in unix_dgram_connect()  local
1554 		other = unix_find_other(sock_net(sk), sunaddr, alen, sock->type, 0);  in unix_dgram_connect()
1555 		if (IS_ERR(other)) {  in unix_dgram_connect()
1556 			err = PTR_ERR(other);  in unix_dgram_connect()
1560 		unix_state_double_lock(sk, other);  in unix_dgram_connect()
1563 		if (sock_flag(other, SOCK_DEAD)) {  in unix_dgram_connect()
1564 			unix_state_double_unlock(sk, other);  in unix_dgram_connect()
1565 			sock_put(other);  in unix_dgram_connect()
1570 		if (!unix_may_send(sk, other))  in unix_dgram_connect()
1573 		err = security_unix_may_send(sk->sk_socket, other->sk_socket);  in unix_dgram_connect()
1578 		WRITE_ONCE(other->sk_state, TCP_ESTABLISHED);  in unix_dgram_connect()
1583 		other = NULL;  in unix_dgram_connect()
1584 		unix_state_double_lock(sk, other);  in unix_dgram_connect()
1593 		unix_peer(sk) = other;  in unix_dgram_connect()
1594 		if (!other)  in unix_dgram_connect()
1598 		unix_state_double_unlock(sk, other);  in unix_dgram_connect()
1600 		if (other != old_peer) {  in unix_dgram_connect()
1611 		unix_peer(sk) = other;  in unix_dgram_connect()
1612 		unix_state_double_unlock(sk, other);  in unix_dgram_connect()
1618 	unix_state_double_unlock(sk, other);  in unix_dgram_connect()
1619 	sock_put(other);  in unix_dgram_connect()
1624 static long unix_wait_for_peer(struct sock *other, long timeo)  in unix_wait_for_peer()  argument
1626 	struct unix_sock *u = unix_sk(other);  in unix_wait_for_peer()
1632 	sched = !sock_flag(other, SOCK_DEAD) &&  in unix_wait_for_peer()
1633 		!(other->sk_shutdown & RCV_SHUTDOWN) &&  in unix_wait_for_peer()
1634 		unix_recvq_full_lockless(other);  in unix_wait_for_peer()
1636 	unix_state_unlock(other);  in unix_wait_for_peer()
1649 	struct sock *sk = sock->sk, *newsk = NULL, *other = NULL;  in unix_stream_connect()  local
1699 	other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, flags);  in unix_stream_connect()
1700 	if (IS_ERR(other)) {  in unix_stream_connect()
1701 		err = PTR_ERR(other);  in unix_stream_connect()
1705 	unix_state_lock(other);  in unix_stream_connect()
1708 	if (sock_flag(other, SOCK_DEAD)) {  in unix_stream_connect()
1709 		unix_state_unlock(other);  in unix_stream_connect()
1710 		sock_put(other);  in unix_stream_connect()
1714 	if (other->sk_state != TCP_LISTEN ||  in unix_stream_connect()
1715 	    other->sk_shutdown & RCV_SHUTDOWN) {  in unix_stream_connect()
1720 	if (unix_recvq_full_lockless(other)) {  in unix_stream_connect()
1726 		timeo = unix_wait_for_peer(other, timeo);  in unix_stream_connect()
1727 		sock_put(other);  in unix_stream_connect()
1753 	err = security_unix_stream_connect(sk, other, newsk);  in unix_stream_connect()
1765 	newsk->sk_scm_recv_flags = other->sk_scm_recv_flags;  in unix_stream_connect()
1769 	newu->listener = other;  in unix_stream_connect()
1771 	otheru = unix_sk(other);  in unix_stream_connect()
1798 	copy_peercred(sk, other);  in unix_stream_connect()
1810 	spin_lock(&other->sk_receive_queue.lock);  in unix_stream_connect()
1811 	__skb_queue_tail(&other->sk_receive_queue, skb);  in unix_stream_connect()
1812 	spin_unlock(&other->sk_receive_queue.lock);  in unix_stream_connect()
1813 	unix_state_unlock(other);  in unix_stream_connect()
1814 	other->sk_data_ready(other);  in unix_stream_connect()
1815 	sock_put(other);  in unix_stream_connect()
1819 	unix_state_unlock(other);  in unix_stream_connect()
1820 	sock_put(other);  in unix_stream_connect()
2030  * @other: Receiver sock.
2040 				const struct sock *other)  in unix_maybe_add_creds()  argument
2045 	if (unix_may_passcred(sk) || unix_may_passcred(other) ||  in unix_maybe_add_creds()
2046 	    !other->sk_socket) {  in unix_maybe_add_creds()
2100 	struct sock *sk = sock->sk, *other = NULL;  in unix_dgram_sendmsg()  local
2174 		other = unix_find_other(sock_net(sk), msg->msg_name,  in unix_dgram_sendmsg()
2176 		if (IS_ERR(other)) {  in unix_dgram_sendmsg()
2177 			err = PTR_ERR(other);  in unix_dgram_sendmsg()
2181 		other = unix_peer_get(sk);  in unix_dgram_sendmsg()
2182 		if (!other) {  in unix_dgram_sendmsg()
2188 	if (sk_filter(other, skb) < 0) {  in unix_dgram_sendmsg()
2194 	err = unix_maybe_add_creds(skb, sk, other);  in unix_dgram_sendmsg()
2200 	unix_state_lock(other);  in unix_dgram_sendmsg()
2203 	if (!unix_may_send(sk, other)) {  in unix_dgram_sendmsg()
2208 	if (unlikely(sock_flag(other, SOCK_DEAD))) {  in unix_dgram_sendmsg()
2211 		unix_state_unlock(other);  in unix_dgram_sendmsg()
2215 			 * is clearing @other. Never change state to TCP_CLOSE  in unix_dgram_sendmsg()
2225 		if (unix_peer(sk) == other) {  in unix_dgram_sendmsg()
2227 			unix_dgram_peer_wake_disconnect_wakeup(sk, other);  in unix_dgram_sendmsg()
2232 			unix_dgram_disconnected(sk, other);  in unix_dgram_sendmsg()
2233 			sock_put(other);  in unix_dgram_sendmsg()
2245 		sock_put(other);  in unix_dgram_sendmsg()
2249 	if (other->sk_shutdown & RCV_SHUTDOWN) {  in unix_dgram_sendmsg()
2254 	if (UNIXCB(skb).fp && !other->sk_scm_rights) {  in unix_dgram_sendmsg()
2260 		err = security_unix_may_send(sk->sk_socket, other->sk_socket);  in unix_dgram_sendmsg()
2265 	/* other == sk && unix_peer(other) != sk if  in unix_dgram_sendmsg()
2269 	if (other != sk &&  in unix_dgram_sendmsg()
2270 	    unlikely(unix_peer(other) != sk &&  in unix_dgram_sendmsg()
2271 	    unix_recvq_full_lockless(other))) {  in unix_dgram_sendmsg()
2273 			timeo = unix_wait_for_peer(other, timeo);  in unix_dgram_sendmsg()
2283 			unix_state_unlock(other);  in unix_dgram_sendmsg()
2284 			unix_state_double_lock(sk, other);  in unix_dgram_sendmsg()
2287 		if (unix_peer(sk) != other ||  in unix_dgram_sendmsg()
2288 		    unix_dgram_peer_wake_me(sk, other)) {  in unix_dgram_sendmsg()
2303 	if (sock_flag(other, SOCK_RCVTSTAMP))  in unix_dgram_sendmsg()
2306 	scm_stat_add(other, skb);  in unix_dgram_sendmsg()
2307 	skb_queue_tail(&other->sk_receive_queue, skb);  in unix_dgram_sendmsg()
2308 	unix_state_unlock(other);  in unix_dgram_sendmsg()
2309 	other->sk_data_ready(other);  in unix_dgram_sendmsg()
2310 	sock_put(other);  in unix_dgram_sendmsg()
2317 	unix_state_unlock(other);  in unix_dgram_sendmsg()
2319 	sock_put(other);  in unix_dgram_sendmsg()
2333 static int queue_oob(struct sock *sk, struct msghdr *msg, struct sock *other,  in queue_oob()  argument
2336 	struct unix_sock *ousk = unix_sk(other);  in queue_oob()
2349 	err = unix_maybe_add_creds(skb, sk, other);  in queue_oob()
2359 	unix_state_lock(other);  in queue_oob()
2361 	if (sock_flag(other, SOCK_DEAD) ||  in queue_oob()
2362 	    (other->sk_shutdown & RCV_SHUTDOWN)) {  in queue_oob()
2367 	if (UNIXCB(skb).fp && !other->sk_scm_rights) {  in queue_oob()
2372 	scm_stat_add(other, skb);  in queue_oob()
2374 	spin_lock(&other->sk_receive_queue.lock);  in queue_oob()
2377 	__skb_queue_tail(&other->sk_receive_queue, skb);  in queue_oob()
2378 	spin_unlock(&other->sk_receive_queue.lock);  in queue_oob()
2380 	sk_send_sigurg(other);  in queue_oob()
2381 	unix_state_unlock(other);  in queue_oob()
2382 	other->sk_data_ready(other);  in queue_oob()
2386 	unix_state_unlock(other);  in queue_oob()
2398 	struct sock *other = NULL;  in unix_stream_sendmsg()  local
2425 	other = unix_peer(sk);  in unix_stream_sendmsg()
2426 	if (!other) {  in unix_stream_sendmsg()
2431 	otheru = unix_sk(other);  in unix_stream_sendmsg()
2469 		err = unix_maybe_add_creds(skb, sk, other);  in unix_stream_sendmsg()
2490 		unix_state_lock(other);  in unix_stream_sendmsg()
2492 		if (sock_flag(other, SOCK_DEAD) ||  in unix_stream_sendmsg()
2493 		    (other->sk_shutdown & RCV_SHUTDOWN))  in unix_stream_sendmsg()
2496 		if (UNIXCB(skb).fp && !other->sk_scm_rights) {  in unix_stream_sendmsg()
2497 			unix_state_unlock(other);  in unix_stream_sendmsg()
2502 		scm_stat_add(other, skb);  in unix_stream_sendmsg()
2504 		spin_lock(&other->sk_receive_queue.lock);  in unix_stream_sendmsg()
2506 		__skb_queue_tail(&other->sk_receive_queue, skb);  in unix_stream_sendmsg()
2507 		spin_unlock(&other->sk_receive_queue.lock);  in unix_stream_sendmsg()
2509 		unix_state_unlock(other);  in unix_stream_sendmsg()
2510 		other->sk_data_ready(other);  in unix_stream_sendmsg()
2516 		err = queue_oob(sk, msg, other, &scm, fds_sent);  in unix_stream_sendmsg()
2528 	unix_state_unlock(other);  in unix_stream_sendmsg()
3209 	struct sock *other;  in unix_shutdown()  local
3222 	other = unix_peer(sk);  in unix_shutdown()
3223 	if (other)  in unix_shutdown()
3224 		sock_hold(other);  in unix_shutdown()
3228 	if (other &&  in unix_shutdown()
3232 		const struct proto *prot = READ_ONCE(other->sk_prot);  in unix_shutdown()
3235 			prot->unhash(other);  in unix_shutdown()
3240 		unix_state_lock(other);  in unix_shutdown()
3241 		WRITE_ONCE(other->sk_shutdown, other->sk_shutdown | peer_mode);  in unix_shutdown()
3242 		unix_state_unlock(other);  in unix_shutdown()
3243 		other->sk_state_change(other);  in unix_shutdown()
3245 			sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP);  in unix_shutdown()
3247 			sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN);  in unix_shutdown()
3249 	if (other)  in unix_shutdown()
3250 		sock_put(other);  in unix_shutdown()
3414 	 * we set writable also when the other side has shut down the  in unix_poll()
3426 	struct sock *sk = sock->sk, *other;  in unix_dgram_poll()  local
3466 		other = unix_peer(sk);  in unix_dgram_poll()
3467 		if (other && unix_peer(other) != sk &&  in unix_dgram_poll()
3468 		    unix_recvq_full_lockless(other) &&  in unix_dgram_poll()
3469 		    unix_dgram_peer_wake_me(sk, other))  in unix_dgram_poll()