-/* tcp_timer.c 4.6 81/12/12 */
+/*
+ * Copyright (c) 1982, 1986 Regents of the University of California.
+ * All rights reserved. The Berkeley software License Agreement
+ * specifies the terms and conditions for redistribution.
+ *
+ * @(#)tcp_timer.c 7.1 (Berkeley) %G%
+ */
+
+#include "param.h"
+#include "systm.h"
+#include "mbuf.h"
+#include "socket.h"
+#include "socketvar.h"
+#include "protosw.h"
+#include "errno.h"
-#include "../h/param.h"
-#include "../h/systm.h"
-#include "../h/mbuf.h"
-#include "../h/socket.h"
-#include "../h/socketvar.h"
-#include "../h/protosw.h"
-#include "../net/in.h"
-#include "../net/in_pcb.h"
-#include "../net/in_systm.h"
#include "../net/if.h"
-#include "../net/ip.h"
-#include "../net/ip_var.h"
-#include "../net/tcp.h"
-#include "../net/tcp_fsm.h"
-#include "../net/tcp_seq.h"
-#include "../net/tcp_timer.h"
-#include "../net/tcp_var.h"
-#include "../net/tcpip.h"
-#include "../errno.h"
+#include "../net/route.h"
+
+#include "in.h"
+#include "in_pcb.h"
+#include "in_systm.h"
+#include "ip.h"
+#include "ip_var.h"
+#include "tcp.h"
+#include "tcp_fsm.h"
+#include "tcp_seq.h"
+#include "tcp_timer.h"
+#include "tcp_var.h"
+#include "tcpip.h"
+int tcpnodelack = 0;
/*
* Fast timeout routine for processing delayed acks
*/
tcp_fasttimo()
{
+ register struct inpcb *inp;
+ register struct tcpcb *tp;
+ int s = splnet();
-COUNT(TCP_FASTTIMO);
+ inp = tcb.inp_next;
+ if (inp)
+ for (; inp != &tcb; inp = inp->inp_next)
+ if ((tp = (struct tcpcb *)inp->inp_ppcb) &&
+ (tp->t_flags & TF_DELACK)) {
+ tp->t_flags &= ~TF_DELACK;
+ tp->t_flags |= TF_ACKNOW;
+ (void) tcp_output(tp);
+ }
+ splx(s);
}
/*
*/
tcp_slowtimo()
{
- register struct inpcb *ip;
+ register struct inpcb *ip, *ipnxt;
register struct tcpcb *tp;
int s = splnet();
register int i;
-COUNT(TCP_SLOWTIMO);
/*
* Search through tcb's and update active timers.
splx(s);
return;
}
- for (; ip != &tcb; ip = ip->inp_next) {
+ for (; ip != &tcb; ip = ipnxt) {
+ ipnxt = ip->inp_next;
tp = intotcpcb(ip);
+ if (tp == 0)
+ continue;
for (i = 0; i < TCPT_NTIMERS; i++) {
- if (tp->t_timer[i] && --tp->t_timer[i] == 0)
+ if (tp->t_timer[i] && --tp->t_timer[i] == 0) {
(void) tcp_usrreq(tp->t_inpcb->inp_socket,
PRU_SLOWTIMO, (struct mbuf *)0,
- (caddr_t)i);
+ (struct mbuf *)i, (struct mbuf *)0);
+ if (ipnxt->inp_prev != ip)
+ goto tpgone;
+ }
}
tp->t_idle++;
if (tp->t_rtt)
tp->t_rtt++;
+tpgone:
+ ;
}
tcp_iss += TCP_ISSINCR/PR_SLOWHZ; /* increment iss */
+#ifdef TCP_COMPAT_42
+ if ((int)tcp_iss < 0)
+ tcp_iss = 0; /* XXX */
+#endif
splx(s);
}
{
register int i;
-COUNT(TCP_CANCELTIMERS);
-printf("tcp_canceltimers %x\n", tp);
for (i = 0; i < TCPT_NTIMERS; i++)
tp->t_timer[i] = 0;
}
+int tcp_backoff[TCP_MAXRXTSHIFT+1] =
+ { 1, 2, 4, 6, 8, 10, 15, 20, 30, 30, 30, 30, 30 };
/*
* TCP timer processing.
*/
+struct tcpcb *
tcp_timers(tp, timer)
register struct tcpcb *tp;
int timer;
{
+ register int rexmt;
-COUNT(TCP_TIMERS);
-printf("tcp_timers %x %d\n", tp, timer);
switch (timer) {
/*
- * 2 MSL timeout in shutdown went off. Delete connection
- * control block.
+ * 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:
- tcp_close(tp);
- return;
+ if (tp->t_state != TCPS_TIME_WAIT &&
+ tp->t_idle <= TCPTV_MAXIDLE)
+ tp->t_timer[TCPT_2MSL] = TCPTV_KEEP;
+ 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 all
- * unacknowledged messages in the window.
+ * to a longer retransmit interval and retransmit one segment.
*/
case TCPT_REXMT:
tp->t_rxtshift++;
- TCPT_RANGESET(tp->t_timer[TCPT_REXMT],
- ((int)(2 * tp->t_srtt)) << tp->t_rxtshift,
- TCPTV_MIN, TCPTV_MAX);
-printf("rexmt timer now %d\n", tp->t_timer[TCPT_REXMT]);
+ if (tp->t_rxtshift > TCP_MAXRXTSHIFT) {
+ tp = tcp_drop(tp, ETIMEDOUT);
+ break;
+ }
+ if (tp->t_srtt == 0)
+ rexmt = tcp_beta * TCPTV_SRTTDFLT;
+ else
+ rexmt = (int)(tcp_beta * tp->t_srtt);
+ rexmt *= tcp_backoff[tp->t_rxtshift - 1];
+ TCPT_RANGESET(tp->t_timer[TCPT_REXMT], rexmt,
+ TCPTV_MIN, TCPTV_MAX);
+ /*
+ * If losing, let the lower level know
+ * and try for a better route.
+ */
+ if (tp->t_rxtshift >= TCP_MAXRXTSHIFT / 4 ||
+ rexmt >= 10 * PR_SLOWHZ)
+ in_losing(tp->t_inpcb);
tp->snd_nxt = tp->snd_una;
- /* this only transmits one segment! */
+ /*
+ * If timing a segment in this window,
+ * and we have already gotten some timing estimate,
+ * stop the timer.
+ */
+ if (tp->t_rtt && tp->t_srtt)
+ tp->t_rtt = 0;
(void) tcp_output(tp);
- return;
+ break;
/*
* Persistance 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;
- TCPT_RANGESET(tp->t_timer[TCPT_PERSIST],
- 2 * tp->t_srtt, TCPTV_PERSMIN, TCPTV_MAX);
-printf("persist timer now %d\n", tp->t_timer[TCPT_PERSIST]);
- return;
+ 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 ||
- tp->t_idle >= TCPTV_MAXIDLE) {
-printf("drop because of keep alive\n");
- tcp_drop(tp, ETIMEDOUT);
- return;
+ if (tp->t_state < TCPS_ESTABLISHED)
+ goto dropit;
+ if (tp->t_inpcb->inp_socket->so_options & SO_KEEPALIVE &&
+ tp->t_state <= TCPS_CLOSE_WAIT) {
+ if (tp->t_idle >= TCPTV_MAXIDLE)
+ goto dropit;
+ /*
+ * Saying tp->rcv_nxt-1 lies about what
+ * we have received, and by the protocol spec
+ * requires the correspondent TCP to respond.
+ * Saying tp->snd_una-1 causes the transmitted
+ * byte to lie outside the receive window; this
+ * is important because we don't necessarily
+ * have a byte in the window to send (consider
+ * a one-way stream!)
+ */
+ tcp_respond(tp,
+ tp->t_template, tp->rcv_nxt-1, tp->snd_una-1, 0);
}
-printf("send keep alive\n");
- tcp_respond(tp->t_template, tp->rcv_nxt, tp->snd_una-1, 0);
tp->t_timer[TCPT_KEEP] = TCPTV_KEEP;
- return;
+ break;
+ dropit:
+ tp = tcp_drop(tp, ETIMEDOUT);
+ break;
}
+ return (tp);
}