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Diffstat (limited to 'slirp/src/tcp_timer.c')
m---------slirp0
-rw-r--r--slirp/src/tcp_timer.c294
2 files changed, 0 insertions, 294 deletions
diff --git a/slirp b/slirp
new file mode 160000
+Subproject 59a1b1f165458c2acb7ff0525b543945f741622
diff --git a/slirp/src/tcp_timer.c b/slirp/src/tcp_timer.c
deleted file mode 100644
index be361a1bb6..0000000000
--- a/slirp/src/tcp_timer.c
+++ /dev/null
@@ -1,294 +0,0 @@
-/* SPDX-License-Identifier: BSD-3-Clause */
-/*
- * Copyright (c) 1982, 1986, 1988, 1990, 1993
- * The Regents of the University of California. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * 3. Neither the name of the University nor the names of its contributors
- * may be used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- *
- * @(#)tcp_timer.c 8.1 (Berkeley) 6/10/93
- * tcp_timer.c,v 1.2 1994/08/02 07:49:10 davidg Exp
- */
-
-#include "slirp.h"
-
-static struct tcpcb *tcp_timers(register struct tcpcb *tp, int timer);
-
-/*
- * Fast timeout routine for processing delayed acks
- */
-void
-tcp_fasttimo(Slirp *slirp)
-{
- register struct socket *so;
- register struct tcpcb *tp;
-
- DEBUG_CALL("tcp_fasttimo");
-
- so = slirp->tcb.so_next;
- if (so)
- for (; so != &slirp->tcb; so = so->so_next)
- if ((tp = (struct tcpcb *)so->so_tcpcb) &&
- (tp->t_flags & TF_DELACK)) {
- tp->t_flags &= ~TF_DELACK;
- tp->t_flags |= TF_ACKNOW;
- (void) tcp_output(tp);
- }
-}
-
-/*
- * Tcp protocol timeout routine called every 500 ms.
- * Updates the timers in all active tcb's and
- * causes finite state machine actions if timers expire.
- */
-void
-tcp_slowtimo(Slirp *slirp)
-{
- register struct socket *ip, *ipnxt;
- register struct tcpcb *tp;
- register int i;
-
- DEBUG_CALL("tcp_slowtimo");
-
- /*
- * Search through tcb's and update active timers.
- */
- ip = slirp->tcb.so_next;
- if (ip == NULL) {
- return;
- }
- for (; ip != &slirp->tcb; ip = ipnxt) {
- ipnxt = ip->so_next;
- tp = sototcpcb(ip);
- if (tp == NULL) {
- continue;
- }
- for (i = 0; i < TCPT_NTIMERS; i++) {
- if (tp->t_timer[i] && --tp->t_timer[i] == 0) {
- tcp_timers(tp,i);
- if (ipnxt->so_prev != ip)
- goto tpgone;
- }
- }
- tp->t_idle++;
- if (tp->t_rtt)
- tp->t_rtt++;
-tpgone:
- ;
- }
- slirp->tcp_iss += TCP_ISSINCR/PR_SLOWHZ; /* increment iss */
- slirp->tcp_now++; /* for timestamps */
-}
-
-/*
- * Cancel all timers for TCP tp.
- */
-void
-tcp_canceltimers(struct tcpcb *tp)
-{
- register int i;
-
- for (i = 0; i < TCPT_NTIMERS; i++)
- tp->t_timer[i] = 0;
-}
-
-const int tcp_backoff[TCP_MAXRXTSHIFT + 1] =
- { 1, 2, 4, 8, 16, 32, 64, 64, 64, 64, 64, 64, 64 };
-
-/*
- * TCP timer processing.
- */
-static struct tcpcb *
-tcp_timers(register struct tcpcb *tp, int timer)
-{
- register int rexmt;
-
- DEBUG_CALL("tcp_timers");
-
- switch (timer) {
-
- /*
- * 2 MSL timeout in shutdown went off. If we're closed but
- * still waiting for peer to close and connection has been idle
- * too long, or if 2MSL time is up from TIME_WAIT, delete connection
- * control block. Otherwise, check again in a bit.
- */
- case TCPT_2MSL:
- if (tp->t_state != TCPS_TIME_WAIT &&
- tp->t_idle <= TCP_MAXIDLE)
- tp->t_timer[TCPT_2MSL] = TCPTV_KEEPINTVL;
- else
- tp = tcp_close(tp);
- break;
-
- /*
- * Retransmission timer went off. Message has not
- * been acked within retransmit interval. Back off
- * to a longer retransmit interval and retransmit one segment.
- */
- case TCPT_REXMT:
-
- /*
- * XXXXX If a packet has timed out, then remove all the queued
- * packets for that session.
- */
-
- if (++tp->t_rxtshift > TCP_MAXRXTSHIFT) {
- /*
- * This is a hack to suit our terminal server here at the uni of canberra
- * since they have trouble with zeroes... It usually lets them through
- * unharmed, but under some conditions, it'll eat the zeros. If we
- * keep retransmitting it, it'll keep eating the zeroes, so we keep
- * retransmitting, and eventually the connection dies...
- * (this only happens on incoming data)
- *
- * So, if we were gonna drop the connection from too many retransmits,
- * don't... instead halve the t_maxseg, which might break up the NULLs and
- * let them through
- *
- * *sigh*
- */
-
- tp->t_maxseg >>= 1;
- if (tp->t_maxseg < 32) {
- /*
- * We tried our best, now the connection must die!
- */
- tp->t_rxtshift = TCP_MAXRXTSHIFT;
- tp = tcp_drop(tp, tp->t_softerror);
- /* tp->t_softerror : ETIMEDOUT); */ /* XXX */
- return (tp); /* XXX */
- }
-
- /*
- * Set rxtshift to 6, which is still at the maximum
- * backoff time
- */
- tp->t_rxtshift = 6;
- }
- rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift];
- TCPT_RANGESET(tp->t_rxtcur, rexmt,
- (short)tp->t_rttmin, TCPTV_REXMTMAX); /* XXX */
- tp->t_timer[TCPT_REXMT] = tp->t_rxtcur;
- /*
- * If losing, let the lower level know and try for
- * a better route. Also, if we backed off this far,
- * our srtt estimate is probably bogus. Clobber it
- * so we'll take the next rtt measurement as our srtt;
- * move the current srtt into rttvar to keep the current
- * retransmit times until then.
- */
- if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
- tp->t_rttvar += (tp->t_srtt >> TCP_RTT_SHIFT);
- tp->t_srtt = 0;
- }
- tp->snd_nxt = tp->snd_una;
- /*
- * If timing a segment in this window, stop the timer.
- */
- tp->t_rtt = 0;
- /*
- * Close the congestion window down to one segment
- * (we'll open it by one segment for each ack we get).
- * Since we probably have a window's worth of unacked
- * data accumulated, this "slow start" keeps us from
- * dumping all that data as back-to-back packets (which
- * might overwhelm an intermediate gateway).
- *
- * There are two phases to the opening: Initially we
- * open by one mss on each ack. This makes the window
- * size increase exponentially with time. If the
- * window is larger than the path can handle, this
- * exponential growth results in dropped packet(s)
- * almost immediately. To get more time between
- * drops but still "push" the network to take advantage
- * of improving conditions, we switch from exponential
- * to linear window opening at some threshold size.
- * For a threshold, we use half the current window
- * size, truncated to a multiple of the mss.
- *
- * (the minimum cwnd that will give us exponential
- * growth is 2 mss. We don't allow the threshold
- * to go below this.)
- */
- {
- unsigned win = MIN(tp->snd_wnd, tp->snd_cwnd) / 2 / tp->t_maxseg;
- if (win < 2)
- win = 2;
- tp->snd_cwnd = tp->t_maxseg;
- tp->snd_ssthresh = win * tp->t_maxseg;
- tp->t_dupacks = 0;
- }
- (void) tcp_output(tp);
- break;
-
- /*
- * Persistence timer into zero window.
- * Force a byte to be output, if possible.
- */
- case TCPT_PERSIST:
- tcp_setpersist(tp);
- tp->t_force = 1;
- (void) tcp_output(tp);
- tp->t_force = 0;
- break;
-
- /*
- * Keep-alive timer went off; send something
- * or drop connection if idle for too long.
- */
- case TCPT_KEEP:
- if (tp->t_state < TCPS_ESTABLISHED)
- goto dropit;
-
- if (slirp_do_keepalive && tp->t_state <= TCPS_CLOSE_WAIT) {
- if (tp->t_idle >= TCPTV_KEEP_IDLE + TCP_MAXIDLE)
- goto dropit;
- /*
- * Send a packet designed to force a response
- * if the peer is up and reachable:
- * either an ACK if the connection is still alive,
- * or an RST if the peer has closed the connection
- * due to timeout or reboot.
- * Using sequence number tp->snd_una-1
- * causes the transmitted zero-length segment
- * to lie outside the receive window;
- * by the protocol spec, this requires the
- * correspondent TCP to respond.
- */
- tcp_respond(tp, &tp->t_template, (struct mbuf *)NULL,
- tp->rcv_nxt, tp->snd_una - 1, 0,
- tp->t_socket->so_ffamily);
- tp->t_timer[TCPT_KEEP] = TCPTV_KEEPINTVL;
- } else
- tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_IDLE;
- break;
-
- dropit:
- tp = tcp_drop(tp, 0);
- break;
- }
-
- return (tp);
-}
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