bsd/netinet/tcp_timer.c

246 static void tcp_remove_timer(struct tcpcb *tp);
248 static uint32_t tcp_run_conn_timer(struct tcpcb *tp, uint16_t *next_index);
249 static void tcp_sched_timers(struct tcpcb *tp);
264 #define TIMER_IS_ON_LIST(tp) ((tp)->t_flags & TF_TIMER_ONLIST)
267 void	add_to_time_wait_locked(struct tcpcb *tp, uint32_t delay);
268 void	add_to_time_wait(struct tcpcb *tp, uint32_t delay) ;
272 void	add_to_time_wait_locked(struct tcpcb *tp, uint32_t delay)
281 	LIST_REMOVE(tp->t_inpcb, inp_list);
283 	/* if (tp->t_timer[TCPT_2MSL] <= 0)
284 	    tp->t_timer[TCPT_2MSL] = 1; */
293 	tp->t_rcvtime = (tp->t_rcvtime / TCP_RETRANSHZ) * PR_SLOWHZ;
295 	tp->t_rcvtime += timer & (N_TIME_WAIT_SLOTS - 1);
301 	LIST_INSERT_HEAD(&time_wait_slots[tw_slot], tp->t_inpcb, inp_list);
304 void	add_to_time_wait(struct tcpcb *tp, uint32_t delay)
309 		tcp_unlock(tp->t_inpcb->inp_socket, 0, 0);
311 		tcp_lock(tp->t_inpcb->inp_socket, 0, 0);
313 	add_to_time_wait_locked(tp, delay);
321 	struct tcpcb *tp;
324 	tp = intotcpcb(inp);
353 	    ((tp != NULL) && (tp->t_state == TCPS_CLOSED) && (so->so_head != NULL)
387 			struct tcpcb *, tp, int32_t, TCPS_CLOSED);
391 		/* If this tp still happens to be on the timer list,
394 		if (TIMER_IS_ON_LIST(tp)) {
395 			tcp_remove_timer(tp);
416 	struct tcpcb *tp;
469 		tp = intotcpcb(inp);
470 		if (tp == NULL)  /* tp already closed, remove from list */
473 		if (tp->t_timer[TCPT_2MSL] >= N_TIME_WAIT_SLOTS) {
474 		    tp->t_timer[TCPT_2MSL] -= N_TIME_WAIT_SLOTS;
475 		    tp->t_rcvtime += N_TIME_WAIT_SLOTS;
478 		    tp->t_timer[TCPT_2MSL] = 0;
480 		if (tp->t_timer[TCPT_2MSL] == 0)  {
483 			tcp_free_sackholes(tp);
484 			tp = tcp_close(tp);
508  * Cancel all timers for TCP tp.
511 tcp_canceltimers(tp)
512 	struct tcpcb *tp;
516 	tcp_remove_timer(tp);
518 		tp->t_timer[i] = 0;
519 	tp->tentry.timer_start = tcp_now;
520 	tp->tentry.index = TCPT_NONE;
535 tcp_timers(tp, timer)
536 	register struct tcpcb *tp;
550 	int isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV4) == 0;
553 	so = tp->t_inpcb->inp_socket;
554 	idle_time = tcp_now - tp->t_rcvtime;
567 		tcp_free_sackholes(tp);
568 		if (tp->t_state != TCPS_TIME_WAIT &&
569 		    tp->t_state != TCPS_FIN_WAIT_2 &&
571 			tp->t_timer[TCPT_2MSL] = OFFSET_FROM_START(tp, (u_int32_t)tcp_keepintvl);
574 			tp = tcp_close(tp);
575 			return(tp);
592 		if (++tp->t_rxtshift > TCP_MAXRXTSHIFT ||
593 			(tp->rxt_conndroptime > 0 && tp->rxt_start > 0 &&
594 			(tcp_now - tp->rxt_start) >= tp->rxt_conndroptime) ||
595 			((tp->t_flagsext & TF_RXTFINDROP) != 0 &&
596 			(tp->t_flags & TF_SENTFIN) != 0 &&
597 			tp->t_rxtshift >= 4)) {
599 			if ((tp->t_flagsext & TF_RXTFINDROP) != 0) {
604 			tp->t_rxtshift = TCP_MAXRXTSHIFT;
608 			tp = tcp_drop(tp, tp->t_softerror ?
609 			    tp->t_softerror : ETIMEDOUT);
614 		if (tp->t_rxtshift == 1) {
624 			tp->snd_cwnd_prev = tp->snd_cwnd;
625 			tp->snd_ssthresh_prev = tp->snd_ssthresh;
626 			tp->snd_recover_prev = tp->snd_recover;
627 			if (IN_FASTRECOVERY(tp))
628 				  tp->t_flags |= TF_WASFRECOVERY;
630 				  tp->t_flags &= ~TF_WASFRECOVERY;
631 			tp->t_badrxtwin = tcp_now  + (tp->t_srtt >> (TCP_RTT_SHIFT));
636 			tp->rxt_start = tcp_now;
640 		if (tp->t_state == TCPS_SYN_SENT)
641 			rexmt = TCP_REXMTVAL(tp) * tcp_syn_backoff[tp->t_rxtshift];
643 			rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift];
644 		TCPT_RANGESET(tp->t_rxtcur, rexmt,
645 			tp->t_rttmin, TCPTV_REXMTMAX,
646 			TCP_ADD_REXMTSLOP(tp));
647 		tp->t_timer[TCPT_REXMT] = OFFSET_FROM_START(tp, tp->t_rxtcur);
649 		if (INP_WAIT_FOR_IF_FEEDBACK(tp->t_inpcb))
652 		tcp_free_sackholes(tp);
657 		if (tcp_pmtud_black_hole_detect && (tp->t_state == TCPS_ESTABLISHED)) {
658 			if (((tp->t_flags & (TF_PMTUD|TF_MAXSEGSNT)) == (TF_PMTUD|TF_MAXSEGSNT)) &&
659 				 (tp->t_rxtshift == 2)) {
666 				tp->t_flags &= ~TF_PMTUD; /* Disable Path MTU Discovery for now */
667 				tp->t_flags |= TF_BLACKHOLE; /* Record that we may have found a black hole */
668 				optlen = tp->t_maxopd - tp->t_maxseg;
669 				tp->t_pmtud_saved_maxopd = tp->t_maxopd; /* Keep track of previous MSS */
670 				if (tp->t_maxopd > tcp_pmtud_black_hole_mss)
671 					tp->t_maxopd = tcp_pmtud_black_hole_mss; /* Reduce the MSS to intermediary value */
673 					tp->t_maxopd = 	/* use the default MSS */
679 				tp->t_maxseg = tp->t_maxopd - optlen;
684 				if (CC_ALGO(tp)->cwnd_init != NULL)
685 					CC_ALGO(tp)->cwnd_init(tp);
694 				if ((tp->t_flags & TF_BLACKHOLE) && (tp->t_rxtshift > 4)) {
695 					tp->t_flags |= TF_PMTUD;
696 					tp->t_flags &= ~TF_BLACKHOLE;
697 					optlen = tp->t_maxopd - tp->t_maxseg;
698 					tp->t_maxopd = tp->t_pmtud_saved_maxopd;
699 					tp->t_maxseg = tp->t_maxopd - optlen;
703 					if (CC_ALGO(tp)->cwnd_init != NULL)
704 						CC_ALGO(tp)->cwnd_init(tp);
717 		if ((tp->t_state == TCPS_SYN_SENT) &&
718 		    (tp->t_rxtshift == tcp_broken_peer_syn_rxmit_thres))
719 			tp->t_flags &= ~(TF_REQ_SCALE|TF_REQ_TSTMP|TF_REQ_CC);
729 		if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
732 				in6_losing(tp->t_inpcb);
735 			in_losing(tp->t_inpcb);
736 			tp->t_rttvar += (tp->t_srtt >> TCP_RTT_SHIFT);
737 			tp->t_srtt = 0;
739 		tp->snd_nxt = tp->snd_una;
744 		tp->snd_recover = tp->snd_max;
748 		tp->t_flags |= TF_ACKNOW;
752 		tp->t_rtttime = 0;
754 		if (CC_ALGO(tp)->after_timeout != NULL)
755 			CC_ALGO(tp)->after_timeout(tp);
757 		tp->t_dupacks = 0;
758 		EXIT_FASTRECOVERY(tp);
763 		if ((tp->ecn_flags & TE_ECN_ON) == TE_ECN_ON) {
764 			tp->ecn_flags |= TE_SENDCWR;
767 		DTRACE_TCP5(cc, void, NULL, struct inpcb *, tp->t_inpcb,
768 			struct tcpcb *, tp, struct tcphdr *, NULL,
771 		(void) tcp_output(tp);
791 		if ((tp->t_rxtshift == TCP_MAXRXTSHIFT &&
793 		    idle_time >= TCP_REXMTVAL(tp) * tcp_totbackoff)) ||
794 		    ((tp->t_persist_stop != 0) &&
795 			TSTMP_LEQ(tp->t_persist_stop, tcp_now))) {
800 			tp = tcp_drop(tp, ETIMEDOUT);
803 		tcp_setpersist(tp);
804 		tp->t_force = 1;
805 		(void) tcp_output(tp);
806 		tp->t_force = 0;
815 		if (tp->t_state < TCPS_ESTABLISHED)
818 		    tp->t_inpcb->inp_socket->so_options & SO_KEEPALIVE) &&
819 		    (tp->t_state <= TCPS_CLOSING || tp->t_state == TCPS_FIN_WAIT_2)) {
820 		    	if (idle_time >= TCP_KEEPIDLE(tp) + (u_int32_t)tcp_maxidle)
828 			 * Using sequence number tp->snd_una-1
835 			t_template = tcp_maketemplate(tp);
839 				if (tp->t_inpcb->inp_flags & INP_BOUND_IF)
840 					ifscope = tp->t_inpcb->inp_boundifp->if_index;
848 				if (tp->t_inpcb->inp_flags & INP_NO_IFT_CELLULAR)
851 				tcp_respond(tp, t_template->tt_ipgen,
853 				    tp->rcv_nxt, tp->snd_una - 1, 0, ifscope,
857 			tp->t_timer[TCPT_KEEP] = OFFSET_FROM_START(tp, tcp_keepintvl);
859 			tp->t_timer[TCPT_KEEP] = OFFSET_FROM_START(tp, TCP_KEEPIDLE(tp));
862 		if (tcp_delack_enabled && (tp->t_flags & TF_DELACK)) {
863 			tp->t_flags &= ~TF_DELACK;
864 			tp->t_timer[TCPT_DELACK] = 0;
865 			tp->t_flags |= TF_ACKNOW;
870 			if ((tp->t_flags & TF_STRETCHACK) != 0)
871 				tcp_reset_stretch_ack(tp);
878 			CLEAR_IAJ_STATE(tp);
881 			(void) tcp_output(tp);
886 	if (tp->t_inpcb->inp_socket->so_options & SO_DEBUG)
887 		tcp_trace(TA_USER, ostate, tp, (void *)0, (struct tcphdr *)0,
895 		tp = tcp_drop(tp, ETIMEDOUT);
898 	return (tp);
903 tcp_remove_timer(struct tcpcb *tp)
907 	lck_mtx_assert(&tp->t_inpcb->inpcb_mtx, LCK_MTX_ASSERT_OWNED);
908 	if (!(TIMER_IS_ON_LIST(tp))) {
914 	if (!(TIMER_IS_ON_LIST(tp))) {
919 	if (listp->next_te != NULL && listp->next_te == &tp->tentry)
920 		listp->next_te = LIST_NEXT(&tp->tentry, le);
922 	LIST_REMOVE(&tp->tentry, le);
923 	tp->t_flags &= ~(TF_TIMER_ONLIST);
927 	tp->tentry.le.le_next = NULL;
928 	tp->tentry.le.le_prev = NULL;
993 tcp_run_conn_timer(struct tcpcb *tp, uint16_t *next_index) {
1002         VERIFY(tp != NULL);
1005         tcp_lock(tp->t_inpcb->inp_socket, 1, 0);
1007         so = tp->t_inpcb->inp_socket;
1009 	if (in_pcb_checkstate(tp->t_inpcb, WNT_RELEASE, 1) == WNT_STOPUSING) {
1010 		if (TIMER_IS_ON_LIST(tp)) {
1011 			tcp_remove_timer(tp);
1024 	index = tp->tentry.index;
1025 	timer_val = tp->t_timer[index];
1027         if (index == TCPT_NONE || tp->tentry.runtime == 0)
1030 	diff = timer_diff(tp->tentry.runtime, 0, tcp_now, 0);
1032 		if (tp->tentry.index != TCPT_NONE) {
1034 			*(next_index) = tp->tentry.index;
1039 	tp->t_timer[index] = 0;
1041 		tp = tcp_timers(tp, index);
1042 		if (tp == NULL)
1050 		if (tp->t_timer[i] != 0) {
1051 			diff = timer_diff(tp->tentry.timer_start, tp->t_timer[i], tcp_now, 0);
1053 				tp->t_timer[i] = 0;
1057 				tp->t_timer[i] = diff;
1067 	tp->tentry.timer_start = tcp_now;
1068 	tp->tentry.index = lo_index;
1070 		tp->tentry.runtime = tp->tentry.timer_start + tp->t_timer[lo_index];
1072 		tp->tentry.runtime = 0;
1079 				tp->t_timer[i] = 0;
1080 				tp = tcp_timers(tp, i);
1081 				if (tp == NULL)
1085 		tcp_set_lotimer_index(tp);
1088 	if (tp->tentry.index < TCPT_NONE) {
1089 		offset = tp->t_timer[tp->tentry.index];
1090 		*(next_index) = tp->tentry.index;
1094 	if (tp != NULL && tp->tentry.index == TCPT_NONE) {
1095 		tcp_remove_timer(tp);
1108 	struct tcpcb *tp;
1133 		tp = TIMERENTRY_TO_TP(te);
1138 		if (in_pcb_checkstate(tp->t_inpcb, WNT_ACQUIRE, 0) == WNT_STOPUSING) {
1143 			if (TIMER_IS_ON_LIST(tp)) {
1144 				tp->t_flags &= ~(TF_TIMER_ONLIST);
1145 				LIST_REMOVE(&tp->tentry, le);
1148 				tp->tentry.le.le_next = NULL;
1149 				tp->tentry.le.le_prev = NULL;
1160 		VERIFY_NEXT_LINK(&tp->tentry, le);
1161 		VERIFY_PREV_LINK(&tp->tentry, le);
1166 		offset = tcp_run_conn_timer(tp, &index);
1233 tcp_sched_timers(struct tcpcb *tp)
1235 	struct tcptimerentry *te = &tp->tentry;
1242 	if (tp->t_inpcb->inp_state == INPCB_STATE_DEAD) {
1244 		if (TIMER_IS_ON_LIST(tp)) {
1245 			tcp_remove_timer(tp);
1251 		tcp_remove_timer(tp);
1264 	if (!TIMER_IS_ON_LIST(tp)) {
1271 		tp->t_flags |= TF_TIMER_ONLIST;
1331 tcp_set_lotimer_index(struct tcpcb *tp) {
1335 		if (tp->t_timer[i] != 0 &&
1336 			(lo_timer == 0 || tp->t_timer[i] < lo_timer)) {
1337 			lo_timer = tp->t_timer[i];
1341 	tp->tentry.index = lo_index;
1343 		tp->tentry.runtime = tp->tentry.timer_start + tp->t_timer[lo_index];
1345 		tp->tentry.runtime = 0;
1350 tcp_check_timer_state(struct tcpcb *tp) {
1352 	lck_mtx_assert(&tp->t_inpcb->inpcb_mtx, LCK_MTX_ASSERT_OWNED);
1354 	tcp_set_lotimer_index(tp);
1356 	tcp_sched_timers(tp);