Differential D29441 Diff 91107 sys/netinet/tcp_input.c

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sys/netinet/tcp_input.c

Show First 20 Lines • Show All 2,606 Lines • ▼ Show 20 Lines	if (SEQ_LEQ(th->th_ack, tp->snd_una)) {
break;		break;
else if (!tcp_timer_active(tp, TT_REXMT))		else if (!tcp_timer_active(tp, TT_REXMT))
tp->t_dupacks = 0;		tp->t_dupacks = 0;
else if (++tp->t_dupacks > tcprexmtthresh \|\|		else if (++tp->t_dupacks > tcprexmtthresh \|\|
IN_FASTRECOVERY(tp->t_flags)) {		IN_FASTRECOVERY(tp->t_flags)) {
cc_ack_received(tp, th, nsegs,		cc_ack_received(tp, th, nsegs,
CC_DUPACK);		CC_DUPACK);
if (V_tcp_do_prr &&		if (V_tcp_do_prr &&
IN_FASTRECOVERY(tp->t_flags) &&		IN_FASTRECOVERY(tp->t_flags)) {
(tp->t_flags & TF_SACK_PERMIT)) {
tcp_do_prr_ack(tp, th, &to);		tcp_do_prr_ack(tp, th, &to);
} else if ((tp->t_flags & TF_SACK_PERMIT) &&		} else if ((tp->t_flags & TF_SACK_PERMIT) &&
(to.to_flags & TOF_SACK) &&		(to.to_flags & TOF_SACK) &&
IN_FASTRECOVERY(tp->t_flags)) {		IN_FASTRECOVERY(tp->t_flags)) {
int awnd;		int awnd;

/*		/*
* Compute the amount of data in flight first.		* Compute the amount of data in flight first.
▲ Show 20 Lines • Show All 59 Lines • ▼ Show 20 Lines	enter_recovery:
CC_DUPACK);		CC_DUPACK);
tcp_timer_activate(tp, TT_REXMT, 0);		tcp_timer_activate(tp, TT_REXMT, 0);
tp->t_rtttime = 0;		tp->t_rtttime = 0;
if (V_tcp_do_prr) {		if (V_tcp_do_prr) {
/*		/*
* snd_ssthresh is already updated by		* snd_ssthresh is already updated by
* cc_cong_signal.		* cc_cong_signal.
*/		*/
		if ((tp->t_flags & TF_SACK_PERMIT) &&
		(to.to_flags & TOF_SACK)) {
tp->sackhint.prr_delivered =		tp->sackhint.prr_delivered =
tp->sackhint.sacked_bytes;		tp->sackhint.sacked_bytes;
		} else {
		tp->sackhint.prr_delivered =
		imin(tp->snd_max - tp->snd_una,
		imin(INT_MAX / 65536,
		jtlUnsubmitted Not Done Inline Actions Are you sure this can never wrap? jtl: Are you sure this can never wrap?
		tp->t_dupacks) * maxseg);
		}
tp->sackhint.recover_fs = max(1,		tp->sackhint.recover_fs = max(1,
tp->snd_nxt - tp->snd_una);		tp->snd_nxt - tp->snd_una);
}		}
if ((tp->t_flags & TF_SACK_PERMIT) &&		if ((tp->t_flags & TF_SACK_PERMIT) &&
(to.to_flags & TOF_SACK)) {		(to.to_flags & TOF_SACK)) {
TCPSTAT_INC(		TCPSTAT_INC(
tcps_sack_recovery_episode);		tcps_sack_recovery_episode);
tp->snd_recover = tp->snd_nxt;		tp->snd_recover = tp->snd_nxt;
▲ Show 20 Lines • Show All 1,261 Lines • ▼ Show 20 Lines	tcp_do_prr_ack(struct tcpcb tp, struct tcphdr th, struct tcpopt *to)

INP_WLOCK_ASSERT(tp->t_inpcb);		INP_WLOCK_ASSERT(tp->t_inpcb);

/*		/*
* Compute the amount of data that this ACK is indicating		* Compute the amount of data that this ACK is indicating
* (del_data) and an estimate of how many bytes are in the		* (del_data) and an estimate of how many bytes are in the
* network.		* network.
*/		*/
		if (((tp->t_flags & TF_SACK_PERMIT) &&
		(to->to_flags & TOF_SACK)) \|\|
		(IN_CONGRECOVERY(tp->t_flags) &&
		!IN_FASTRECOVERY(tp->t_flags))) {
del_data = tp->sackhint.delivered_data;		del_data = tp->sackhint.delivered_data;
if (V_tcp_do_newsack)		if (V_tcp_do_newsack)
pipe = tcp_compute_pipe(tp);		pipe = tcp_compute_pipe(tp);
else		else
pipe = (tp->snd_nxt - tp->snd_fack) + tp->sackhint.sack_bytes_rexmit;		pipe = (tp->snd_nxt - tp->snd_fack) +
		tp->sackhint.sack_bytes_rexmit;
		} else {
		if (tp->sackhint.prr_delivered < (tcprexmtthresh * maxseg +
		tp->snd_recover - tp->snd_una))
		del_data = maxseg;
		pipe = imax(0, tp->snd_max - tp->snd_una -
		imin(INT_MAX / 65536, tp->t_dupacks) * maxseg);
		jtlUnsubmitted Not Done Inline Actions Again, can t_dupacks * maxseg never wrap? jtl: Again, can t_dupacks * maxseg never wrap?
		}
tp->sackhint.prr_delivered += del_data;		tp->sackhint.prr_delivered += del_data;
/*		/*
* Proportional Rate Reduction		* Proportional Rate Reduction
*/		*/
if (pipe >= tp->snd_ssthresh) {		if (pipe >= tp->snd_ssthresh) {
if (tp->sackhint.recover_fs == 0)		if (tp->sackhint.recover_fs == 0)
tp->sackhint.recover_fs =		tp->sackhint.recover_fs =
imax(1, tp->snd_nxt - tp->snd_una);		imax(1, tp->snd_nxt - tp->snd_una);
snd_cnt = howmany((long)tp->sackhint.prr_delivered *		snd_cnt = howmany((long)tp->sackhint.prr_delivered *
tp->snd_ssthresh, tp->sackhint.recover_fs) -		tp->snd_ssthresh, tp->sackhint.recover_fs) -
tp->sackhint.prr_out;		tp->sackhint.prr_out;
} else {		} else {
if (V_tcp_do_prr_conservative)		if (V_tcp_do_prr_conservative \|\| (del_data == 0))
limit = tp->sackhint.prr_delivered -		limit = tp->sackhint.prr_delivered -
tp->sackhint.prr_out;		tp->sackhint.prr_out;
else		else
limit = imax(tp->sackhint.prr_delivered -		limit = imax(tp->sackhint.prr_delivered -
tp->sackhint.prr_out, del_data) +		tp->sackhint.prr_out, del_data) +
maxseg;		maxseg;
snd_cnt = imin((tp->snd_ssthresh - pipe), limit);		snd_cnt = imin((tp->snd_ssthresh - pipe), limit);
}		}
snd_cnt = imax(snd_cnt, 0) / maxseg;		snd_cnt = imax(snd_cnt, 0) / maxseg;
/*		/*
* Send snd_cnt new data into the network in response to this ack.		* Send snd_cnt new data into the network in response to this ack.
* If there is going to be a SACK retransmission, adjust snd_cwnd		* If there is going to be a SACK retransmission, adjust snd_cwnd
* accordingly.		* accordingly.
*/		*/
if (IN_FASTRECOVERY(tp->t_flags)) {		if (IN_FASTRECOVERY(tp->t_flags)) {
tp->snd_cwnd = imax(maxseg, tp->snd_nxt - tp->snd_recover +		if ((tp->t_flags & TF_SACK_PERMIT) &&
tp->sackhint.sack_bytes_rexmit + (snd_cnt * maxseg));		(to->to_flags & TOF_SACK)) {
		tp->snd_cwnd = tp->snd_nxt - tp->snd_recover +
		tp->sackhint.sack_bytes_rexmit +
		(snd_cnt * maxseg);
		} else {
		tp->snd_cwnd = (tp->snd_max - tp->snd_una) +
		(snd_cnt * maxseg);
		}
} else if (IN_CONGRECOVERY(tp->t_flags))		} else if (IN_CONGRECOVERY(tp->t_flags))
tp->snd_cwnd = imax(maxseg, pipe - del_data +		tp->snd_cwnd = pipe - del_data + (snd_cnt * maxseg);
(snd_cnt * maxseg));		tp->snd_cwnd = imax(maxseg, tp->snd_cwnd);
}		}

/*		/*
* On a partial ack arrives, force the retransmission of the		* On a partial ack arrives, force the retransmission of the
* next unacknowledged segment. Do not clear tp->t_dupacks.		* next unacknowledged segment. Do not clear tp->t_dupacks.
* By setting snd_nxt to ti_ack, this forces retransmission timer to		* By setting snd_nxt to ti_ack, this forces retransmission timer to
* be started again.		* be started again.
*/		*/
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