27 static u32 tcp_clamp_rto_to_user_timeout(const struct sock *sk)  in tcp_clamp_rto_to_user_timeout()  argument
29 	const struct inet_connection_sock *icsk = inet_csk(sk);  in tcp_clamp_rto_to_user_timeout()
30 	const struct tcp_sock *tp = tcp_sk(sk);  in tcp_clamp_rto_to_user_timeout()
49 u32 tcp_clamp_probe0_to_user_timeout(const struct sock *sk, u32 when)  in tcp_clamp_probe0_to_user_timeout()  argument
51 	const struct inet_connection_sock *icsk = inet_csk(sk);  in tcp_clamp_probe0_to_user_timeout()
75 static void tcp_write_err(struct sock *sk)  in tcp_write_err()  argument
77 	tcp_done_with_error(sk, READ_ONCE(sk->sk_err_soft) ? : ETIMEDOUT);  in tcp_write_err()
78 	__NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONTIMEOUT);  in tcp_write_err()
105 static int tcp_out_of_resources(struct sock *sk, bool do_reset)  in tcp_out_of_resources()  argument
107 	struct tcp_sock *tp = tcp_sk(sk);  in tcp_out_of_resources()
112 	if ((s32)(tcp_jiffies32 - tp->lsndtime) > 2*tcp_rto_max(sk) || !do_reset)  in tcp_out_of_resources()
116 	if (READ_ONCE(sk->sk_err_soft))  in tcp_out_of_resources()
119 	if (tcp_check_oom(sk, shift)) {  in tcp_out_of_resources()
127 			tcp_send_active_reset(sk, GFP_ATOMIC,  in tcp_out_of_resources()
129 		tcp_done(sk);  in tcp_out_of_resources()
130 		__NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONMEMORY);  in tcp_out_of_resources()
134 	if (!check_net(sock_net(sk))) {  in tcp_out_of_resources()
136 		tcp_done(sk);  in tcp_out_of_resources()
148 static int tcp_orphan_retries(struct sock *sk, bool alive)  in tcp_orphan_retries()  argument
150 	int retries = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_orphan_retries); /* May be zero. */  in tcp_orphan_retries()
153 	if (READ_ONCE(sk->sk_err_soft) && !alive)  in tcp_orphan_retries()
164 static void tcp_mtu_probing(struct inet_connection_sock *icsk, struct sock *sk)  in tcp_mtu_probing()  argument
166 	const struct net *net = sock_net(sk);  in tcp_mtu_probing()
177 		mss = tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_low) >> 1;  in tcp_mtu_probing()
181 		icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, mss);  in tcp_mtu_probing()
183 	tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);  in tcp_mtu_probing()
186 static unsigned int tcp_model_timeout(struct sock *sk,  in tcp_model_timeout()  argument
192 	linear_backoff_thresh = ilog2(tcp_rto_max(sk) / rto_base);  in tcp_model_timeout()
197 			(boundary - linear_backoff_thresh) * tcp_rto_max(sk);  in tcp_model_timeout()
213 static bool retransmits_timed_out(struct sock *sk,  in retransmits_timed_out()  argument
217 	struct tcp_sock *tp = tcp_sk(sk);  in retransmits_timed_out()
220 	if (!inet_csk(sk)->icsk_retransmits)  in retransmits_timed_out()
227 		if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))  in retransmits_timed_out()
228 			rto_base = tcp_timeout_init(sk);  in retransmits_timed_out()
229 		timeout = tcp_model_timeout(sk, boundary, rto_base);  in retransmits_timed_out()
241 static int tcp_write_timeout(struct sock *sk)  in tcp_write_timeout()  argument
243 	struct inet_connection_sock *icsk = inet_csk(sk);  in tcp_write_timeout()
244 	struct tcp_sock *tp = tcp_sk(sk);  in tcp_write_timeout()
245 	struct net *net = sock_net(sk);  in tcp_write_timeout()
249 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {  in tcp_write_timeout()
251 			__dst_negative_advice(sk);  in tcp_write_timeout()
257 		if (sk->sk_state == TCP_SYN_SENT)  in tcp_write_timeout()
262 		if (retransmits_timed_out(sk, READ_ONCE(net->ipv4.sysctl_tcp_retries1), 0)) {  in tcp_write_timeout()
264 			tcp_mtu_probing(icsk, sk);  in tcp_write_timeout()
266 			__dst_negative_advice(sk);  in tcp_write_timeout()
270 		if (sock_flag(sk, SOCK_DEAD)) {  in tcp_write_timeout()
271 			const bool alive = icsk->icsk_rto < tcp_rto_max(sk);  in tcp_write_timeout()
273 			retry_until = tcp_orphan_retries(sk, alive);  in tcp_write_timeout()
275 				!retransmits_timed_out(sk, retry_until, 0);  in tcp_write_timeout()
277 			if (tcp_out_of_resources(sk, do_reset))  in tcp_write_timeout()
282 		expired = retransmits_timed_out(sk, retry_until,  in tcp_write_timeout()
284 	tcp_fastopen_active_detect_blackhole(sk, expired);  in tcp_write_timeout()
285 	mptcp_active_detect_blackhole(sk, expired);  in tcp_write_timeout()
288 		tcp_call_bpf_3arg(sk, BPF_SOCK_OPS_RTO_CB,  in tcp_write_timeout()
294 		tcp_write_err(sk);  in tcp_write_timeout()
298 	if (sk_rethink_txhash(sk)) {  in tcp_write_timeout()
300 		__NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPTIMEOUTREHASH);  in tcp_write_timeout()
307 void tcp_delack_timer_handler(struct sock *sk)  in tcp_delack_timer_handler()  argument
309 	struct inet_connection_sock *icsk = inet_csk(sk);  in tcp_delack_timer_handler()
310 	struct tcp_sock *tp = tcp_sk(sk);  in tcp_delack_timer_handler()
312 	if ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))  in tcp_delack_timer_handler()
318 		tcp_sack_compress_send_ack(sk);  in tcp_delack_timer_handler()
326 		sk_reset_timer(sk, &icsk->icsk_delack_timer,  in tcp_delack_timer_handler()
332 	if (inet_csk_ack_scheduled(sk)) {  in tcp_delack_timer_handler()
333 		if (!inet_csk_in_pingpong_mode(sk)) {  in tcp_delack_timer_handler()
340 			inet_csk_exit_pingpong_mode(sk);  in tcp_delack_timer_handler()
344 		tcp_send_ack(sk);  in tcp_delack_timer_handler()
345 		__NET_INC_STATS(sock_net(sk), LINUX_MIB_DELAYEDACKS);  in tcp_delack_timer_handler()
363 	struct sock *sk = &icsk->icsk_inet.sk;  in tcp_delack_timer()  local
370 	    !READ_ONCE(tcp_sk(sk)->compressed_ack))  in tcp_delack_timer()
373 	bh_lock_sock(sk);  in tcp_delack_timer()
374 	if (!sock_owned_by_user(sk)) {  in tcp_delack_timer()
375 		tcp_delack_timer_handler(sk);  in tcp_delack_timer()
377 		__NET_INC_STATS(sock_net(sk), LINUX_MIB_DELAYEDACKLOCKED);  in tcp_delack_timer()
379 		if (!test_and_set_bit(TCP_DELACK_TIMER_DEFERRED, &sk->sk_tsq_flags))  in tcp_delack_timer()
380 			sock_hold(sk);  in tcp_delack_timer()
382 	bh_unlock_sock(sk);  in tcp_delack_timer()
384 	sock_put(sk);  in tcp_delack_timer()
387 static void tcp_probe_timer(struct sock *sk)  in tcp_probe_timer()  argument
389 	struct inet_connection_sock *icsk = inet_csk(sk);  in tcp_probe_timer()
390 	struct sk_buff *skb = tcp_send_head(sk);  in tcp_probe_timer()
391 	struct tcp_sock *tp = tcp_sk(sk);  in tcp_probe_timer()
418 	max_probes = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_retries2);  in tcp_probe_timer()
419 	if (sock_flag(sk, SOCK_DEAD)) {  in tcp_probe_timer()
420 		unsigned int rto_max = tcp_rto_max(sk);  in tcp_probe_timer()
423 		max_probes = tcp_orphan_retries(sk, alive);  in tcp_probe_timer()
426 		if (tcp_out_of_resources(sk, true))  in tcp_probe_timer()
431 abort:		tcp_write_err(sk);  in tcp_probe_timer()
434 		tcp_send_probe0(sk);  in tcp_probe_timer()
438 static void tcp_update_rto_stats(struct sock *sk)  in tcp_update_rto_stats()  argument
440 	struct inet_connection_sock *icsk = inet_csk(sk);  in tcp_update_rto_stats()
441 	struct tcp_sock *tp = tcp_sk(sk);  in tcp_update_rto_stats()
455 static void tcp_fastopen_synack_timer(struct sock *sk, struct request_sock *req)  in tcp_fastopen_synack_timer()  argument
457 	struct inet_connection_sock *icsk = inet_csk(sk);  in tcp_fastopen_synack_timer()
458 	struct tcp_sock *tp = tcp_sk(sk);  in tcp_fastopen_synack_timer()
467 		READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_synack_retries) + 1;  in tcp_fastopen_synack_timer()
470 		tcp_write_err(sk);  in tcp_fastopen_synack_timer()
475 		tcp_enter_loss(sk);  in tcp_fastopen_synack_timer()
481 	inet_rtx_syn_ack(sk, req);  in tcp_fastopen_synack_timer()
483 	tcp_update_rto_stats(sk);  in tcp_fastopen_synack_timer()
486 	tcp_reset_xmit_timer(sk, ICSK_TIME_RETRANS,  in tcp_fastopen_synack_timer()
490 static bool tcp_rtx_probe0_timed_out(const struct sock *sk,  in tcp_rtx_probe0_timed_out()  argument
494 	const struct inet_connection_sock *icsk = inet_csk(sk);  in tcp_rtx_probe0_timed_out()
496 	const struct tcp_sock *tp = tcp_sk(sk);  in tcp_rtx_probe0_timed_out()
497 	int timeout = tcp_rto_max(sk) * 2;  in tcp_rtx_probe0_timed_out()
531 void tcp_retransmit_timer(struct sock *sk)  in tcp_retransmit_timer()  argument
533 	struct tcp_sock *tp = tcp_sk(sk);  in tcp_retransmit_timer()
534 	struct net *net = sock_net(sk);  in tcp_retransmit_timer()
535 	struct inet_connection_sock *icsk = inet_csk(sk);  in tcp_retransmit_timer()
540 					lockdep_sock_is_held(sk));  in tcp_retransmit_timer()
542 		WARN_ON_ONCE(sk->sk_state != TCP_SYN_RECV &&  in tcp_retransmit_timer()
543 			     sk->sk_state != TCP_FIN_WAIT1);  in tcp_retransmit_timer()
544 		tcp_fastopen_synack_timer(sk, req);  in tcp_retransmit_timer()
554 	skb = tcp_rtx_queue_head(sk);  in tcp_retransmit_timer()
558 	if (!tp->snd_wnd && !sock_flag(sk, SOCK_DEAD) &&  in tcp_retransmit_timer()
559 	    !((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))) {  in tcp_retransmit_timer()
565 		struct inet_sock *inet = inet_sk(sk);  in tcp_retransmit_timer()
573 		if (sk->sk_family == AF_INET) {  in tcp_retransmit_timer()
581 		else if (sk->sk_family == AF_INET6) {  in tcp_retransmit_timer()
583 				&sk->sk_v6_daddr, ntohs(inet->inet_dport),  in tcp_retransmit_timer()
589 		if (tcp_rtx_probe0_timed_out(sk, skb, rtx_delta)) {  in tcp_retransmit_timer()
590 			tcp_write_err(sk);  in tcp_retransmit_timer()
593 		tcp_enter_loss(sk);  in tcp_retransmit_timer()
594 		tcp_retransmit_skb(sk, skb, 1);  in tcp_retransmit_timer()
595 		__sk_dst_reset(sk);  in tcp_retransmit_timer()
599 	__NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPTIMEOUTS);  in tcp_retransmit_timer()
600 	if (tcp_write_timeout(sk))  in tcp_retransmit_timer()
621 			__NET_INC_STATS(sock_net(sk), mib_idx);  in tcp_retransmit_timer()
624 	tcp_enter_loss(sk);  in tcp_retransmit_timer()
626 	tcp_update_rto_stats(sk);  in tcp_retransmit_timer()
627 	if (tcp_retransmit_skb(sk, tcp_rtx_queue_head(sk), 1) > 0) {  in tcp_retransmit_timer()
631 		tcp_reset_xmit_timer(sk, ICSK_TIME_RETRANS,  in tcp_retransmit_timer()
663 	if (sk->sk_state == TCP_ESTABLISHED &&  in tcp_retransmit_timer()
669 				       tcp_rto_min(sk),  in tcp_retransmit_timer()
670 				       tcp_rto_max(sk));  in tcp_retransmit_timer()
671 	} else if (sk->sk_state != TCP_SYN_SENT ||  in tcp_retransmit_timer()
678 		icsk->icsk_rto = min(icsk->icsk_rto << 1, tcp_rto_max(sk));  in tcp_retransmit_timer()
680 	tcp_reset_xmit_timer(sk, ICSK_TIME_RETRANS,  in tcp_retransmit_timer()
681 			     tcp_clamp_rto_to_user_timeout(sk), false);  in tcp_retransmit_timer()
682 	if (retransmits_timed_out(sk, READ_ONCE(net->ipv4.sysctl_tcp_retries1) + 1, 0))  in tcp_retransmit_timer()
683 		__sk_dst_reset(sk);  in tcp_retransmit_timer()
691 void tcp_write_timer_handler(struct sock *sk)  in tcp_write_timer_handler()  argument
693 	struct inet_connection_sock *icsk = inet_csk(sk);  in tcp_write_timer_handler()
696 	if (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)) ||  in tcp_write_timer_handler()
701 		sk_reset_timer(sk, &icsk->icsk_retransmit_timer,  in tcp_write_timer_handler()
705 	tcp_mstamp_refresh(tcp_sk(sk));  in tcp_write_timer_handler()
710 		tcp_rack_reo_timeout(sk);  in tcp_write_timer_handler()
713 		tcp_send_loss_probe(sk);  in tcp_write_timer_handler()
717 		tcp_retransmit_timer(sk);  in tcp_write_timer_handler()
721 		tcp_probe_timer(sk);  in tcp_write_timer_handler()
730 	struct sock *sk = &icsk->icsk_inet.sk;  in tcp_write_timer()  local
736 	bh_lock_sock(sk);  in tcp_write_timer()
737 	if (!sock_owned_by_user(sk)) {  in tcp_write_timer()
738 		tcp_write_timer_handler(sk);  in tcp_write_timer()
741 		if (!test_and_set_bit(TCP_WRITE_TIMER_DEFERRED, &sk->sk_tsq_flags))  in tcp_write_timer()
742 			sock_hold(sk);  in tcp_write_timer()
744 	bh_unlock_sock(sk);  in tcp_write_timer()
746 	sock_put(sk);  in tcp_write_timer()
757 void tcp_reset_keepalive_timer(struct sock *sk, unsigned long len)  in tcp_reset_keepalive_timer()  argument
759 	sk_reset_timer(sk, &sk->sk_timer, jiffies + len);  in tcp_reset_keepalive_timer()
762 static void tcp_delete_keepalive_timer(struct sock *sk)  in tcp_delete_keepalive_timer()  argument
764 	sk_stop_timer(sk, &sk->sk_timer);  in tcp_delete_keepalive_timer()
767 void tcp_set_keepalive(struct sock *sk, int val)  in tcp_set_keepalive()  argument
769 	if ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))  in tcp_set_keepalive()
772 	if (val && !sock_flag(sk, SOCK_KEEPOPEN))  in tcp_set_keepalive()
773 		tcp_reset_keepalive_timer(sk, keepalive_time_when(tcp_sk(sk)));  in tcp_set_keepalive()
775 		tcp_delete_keepalive_timer(sk);  in tcp_set_keepalive()
781 	struct sock *sk = from_timer(sk, t, sk_timer);  in tcp_keepalive_timer()  local
782 	struct inet_connection_sock *icsk = inet_csk(sk);  in tcp_keepalive_timer()
783 	struct tcp_sock *tp = tcp_sk(sk);  in tcp_keepalive_timer()
787 	bh_lock_sock(sk);  in tcp_keepalive_timer()
788 	if (sock_owned_by_user(sk)) {  in tcp_keepalive_timer()
790 		tcp_reset_keepalive_timer(sk, HZ/20);  in tcp_keepalive_timer()
794 	if (sk->sk_state == TCP_LISTEN) {  in tcp_keepalive_timer()
800 	if (sk->sk_state == TCP_FIN_WAIT2 && sock_flag(sk, SOCK_DEAD)) {  in tcp_keepalive_timer()
802 			const int tmo = tcp_fin_time(sk) - TCP_TIMEWAIT_LEN;  in tcp_keepalive_timer()
805 				tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);  in tcp_keepalive_timer()
809 		tcp_send_active_reset(sk, GFP_ATOMIC, SK_RST_REASON_TCP_STATE);  in tcp_keepalive_timer()
813 	if (!sock_flag(sk, SOCK_KEEPOPEN) ||  in tcp_keepalive_timer()
814 	    ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)))  in tcp_keepalive_timer()
820 	if (tp->packets_out || !tcp_write_queue_empty(sk))  in tcp_keepalive_timer()
836 			tcp_send_active_reset(sk, GFP_ATOMIC,  in tcp_keepalive_timer()
838 			tcp_write_err(sk);  in tcp_keepalive_timer()
841 		if (tcp_write_wakeup(sk, LINUX_MIB_TCPKEEPALIVE) <= 0) {  in tcp_keepalive_timer()
856 	tcp_reset_keepalive_timer(sk, elapsed);  in tcp_keepalive_timer()
860 	tcp_done(sk);  in tcp_keepalive_timer()
863 	bh_unlock_sock(sk);  in tcp_keepalive_timer()
864 	sock_put(sk);  in tcp_keepalive_timer()
870 	struct sock *sk = (struct sock *)tp;  in tcp_compressed_ack_kick()  local
872 	bh_lock_sock(sk);  in tcp_compressed_ack_kick()
873 	if (!sock_owned_by_user(sk)) {  in tcp_compressed_ack_kick()
881 			tcp_send_ack(sk);  in tcp_compressed_ack_kick()
885 				      &sk->sk_tsq_flags))  in tcp_compressed_ack_kick()
886 			sock_hold(sk);  in tcp_compressed_ack_kick()
888 	bh_unlock_sock(sk);  in tcp_compressed_ack_kick()
890 	sock_put(sk);  in tcp_compressed_ack_kick()
895 void tcp_init_xmit_timers(struct sock *sk)  in tcp_init_xmit_timers()  argument
897 	inet_csk_init_xmit_timers(sk, &tcp_write_timer, &tcp_delack_timer,  in tcp_init_xmit_timers()
899 	hrtimer_setup(&tcp_sk(sk)->pacing_timer, tcp_pace_kick, CLOCK_MONOTONIC,  in tcp_init_xmit_timers()
902 	hrtimer_setup(&tcp_sk(sk)->compressed_ack_timer, tcp_compressed_ack_kick, CLOCK_MONOTONIC,  in tcp_init_xmit_timers()