diff options
Diffstat (limited to 'c/src/libnetworking/netinet/tcp_timer.c')
-rw-r--r-- | c/src/libnetworking/netinet/tcp_timer.c | 387 |
1 files changed, 0 insertions, 387 deletions
diff --git a/c/src/libnetworking/netinet/tcp_timer.c b/c/src/libnetworking/netinet/tcp_timer.c deleted file mode 100644 index 04d3d604e2..0000000000 --- a/c/src/libnetworking/netinet/tcp_timer.c +++ /dev/null @@ -1,387 +0,0 @@ -/* - * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 - * 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. All advertising materials mentioning features or use of this software - * must display the following acknowledgement: - * This product includes software developed by the University of - * California, Berkeley and its contributors. - * 4. 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 8.2 (Berkeley) 5/24/95 - * $Id$ - */ - -#include "opt_tcpdebug.h" - -#ifndef TUBA_INCLUDE -#include <sys/param.h> -#include <sys/queue.h> -#include <sys/systm.h> -#include <sys/kernel.h> -#include <sys/sysctl.h> -#include <sys/malloc.h> -#include <sys/mbuf.h> -#include <sys/socket.h> -#include <sys/socketvar.h> -#include <sys/protosw.h> -#include <sys/errno.h> - -#include <machine/cpu.h> /* before tcp_seq.h, for tcp_random18() */ - -#include <net/if.h> -#include <net/route.h> - -#include <netinet/in.h> -#include <netinet/in_systm.h> -#include <netinet/ip.h> -#include <netinet/in_pcb.h> -#include <netinet/ip_var.h> -#include <netinet/tcp.h> -#include <netinet/tcp_fsm.h> -#include <netinet/tcp_seq.h> -#include <netinet/tcp_timer.h> -#include <netinet/tcp_var.h> -#include <netinet/tcpip.h> -#ifdef TCPDEBUG -#include <netinet/tcp_debug.h> -#endif - -int tcp_keepinit = TCPTV_KEEP_INIT; -SYSCTL_INT(_net_inet_tcp, TCPCTL_KEEPINIT, keepinit, - CTLFLAG_RW, &tcp_keepinit , 0, ""); - -int tcp_keepidle = TCPTV_KEEP_IDLE; -SYSCTL_INT(_net_inet_tcp, TCPCTL_KEEPIDLE, keepidle, - CTLFLAG_RW, &tcp_keepidle , 0, ""); - -static int tcp_keepintvl = TCPTV_KEEPINTVL; -SYSCTL_INT(_net_inet_tcp, TCPCTL_KEEPINTVL, keepintvl, - CTLFLAG_RW, &tcp_keepintvl , 0, ""); - -static int always_keepalive = 0; -SYSCTL_INT(_net_inet_tcp, OID_AUTO, always_keepalive, - CTLFLAG_RW, &always_keepalive , 0, ""); - -static int tcp_keepcnt = TCPTV_KEEPCNT; - /* max idle probes */ -static int tcp_maxpersistidle = TCPTV_KEEP_IDLE; - /* max idle time in persist */ -int tcp_maxidle; -#else /* TUBA_INCLUDE */ - -static int tcp_maxpersistidle; -#endif /* TUBA_INCLUDE */ - -/* - * Fast timeout routine for processing delayed acks - */ -void -tcp_fasttimo() -{ - register struct inpcb *inp; - register struct tcpcb *tp; - int s; - - s = splnet(); - - for (inp = tcb.lh_first; inp != NULL; inp = inp->inp_list.le_next) { - if ((tp = (struct tcpcb *)inp->inp_ppcb) && - (tp->t_flags & TF_DELACK)) { - tp->t_flags &= ~TF_DELACK; - tp->t_flags |= TF_ACKNOW; - tcpstat.tcps_delack++; - (void) tcp_output(tp); - } - } - splx(s); -} - -/* - * 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() -{ - register struct inpcb *ip, *ipnxt; - register struct tcpcb *tp; - register int i; - int s; -#ifdef TCPDEBUG - int ostate; -#endif - - s = splnet(); - - tcp_maxidle = tcp_keepcnt * tcp_keepintvl; - - ip = tcb.lh_first; - if (ip == NULL) { - splx(s); - return; - } - /* - * Search through tcb's and update active timers. - */ - for (; ip != NULL; ip = ipnxt) { - ipnxt = ip->inp_list.le_next; - tp = intotcpcb(ip); - if (tp == 0 || tp->t_state == TCPS_LISTEN) - continue; - for (i = 0; i < TCPT_NTIMERS; i++) { - if (tp->t_timer[i] && --tp->t_timer[i] == 0) { -#ifdef TCPDEBUG - ostate = tp->t_state; -#endif - tp = tcp_timers(tp, i); - if (tp == NULL) - goto tpgone; -#ifdef TCPDEBUG - if (tp->t_inpcb->inp_socket->so_options - & SO_DEBUG) - tcp_trace(TA_USER, ostate, tp, - (struct tcpiphdr *)0, - PRU_SLOWTIMO); -#endif - } - } - tp->t_idle++; - tp->t_duration++; - 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 = TCP_ISSINCR; /* XXX */ -#endif - tcp_now++; /* for timestamps */ - splx(s); -} -#ifndef TUBA_INCLUDE - -/* - * Cancel all timers for TCP tp. - */ -void -tcp_canceltimers(tp) - struct tcpcb *tp; -{ - register int i; - - for (i = 0; i < TCPT_NTIMERS; i++) - tp->t_timer[i] = 0; -} - -int tcp_backoff[TCP_MAXRXTSHIFT + 1] = - { 1, 2, 4, 8, 16, 32, 64, 64, 64, 64, 64, 64, 64 }; - -static int tcp_totbackoff = 511; /* sum of tcp_backoff[] */ - -/* - * TCP timer processing. - */ -struct tcpcb * -tcp_timers(tp, timer) - register struct tcpcb *tp; - int timer; -{ - register int rexmt; - - 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] = tcp_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: - if (++tp->t_rxtshift > TCP_MAXRXTSHIFT) { - tp->t_rxtshift = TCP_MAXRXTSHIFT; - tcpstat.tcps_timeoutdrop++; - tp = tcp_drop(tp, tp->t_softerror ? - tp->t_softerror : ETIMEDOUT); - break; - } - tcpstat.tcps_rexmttimeo++; - rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift]; - TCPT_RANGESET(tp->t_rxtcur, rexmt, - tp->t_rttmin, TCPTV_REXMTMAX); - 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) { - in_losing(tp->t_inpcb); - tp->t_rttvar += (tp->t_srtt >> TCP_RTT_SHIFT); - tp->t_srtt = 0; - } - tp->snd_nxt = tp->snd_una; - /* - * Force a segment to be sent. - */ - tp->t_flags |= TF_ACKNOW; - /* - * 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 threshhold size. - * For a threshhold, 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 threshhold - * to go below this.) - */ - { - u_int 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; - - /* - * Persistance timer into zero window. - * Force a byte to be output, if possible. - */ - case TCPT_PERSIST: - tcpstat.tcps_persisttimeo++; - /* - * Hack: if the peer is dead/unreachable, we do not - * time out if the window is closed. After a full - * backoff, drop the connection if the idle time - * (no responses to probes) reaches the maximum - * backoff that we would use if retransmitting. - */ - if (tp->t_rxtshift == TCP_MAXRXTSHIFT) { - u_long maxidle = TCP_REXMTVAL(tp); - if (maxidle < tp->t_rttmin) - maxidle = tp->t_rttmin; - maxidle *= tcp_totbackoff; - if (tp->t_idle >= tcp_maxpersistidle || - tp->t_idle >= maxidle) { - tcpstat.tcps_persistdrop++; - tp = tcp_drop(tp, ETIMEDOUT); - break; - } - } - 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: - tcpstat.tcps_keeptimeo++; - if (tp->t_state < TCPS_ESTABLISHED) - goto dropit; - if ((always_keepalive || - tp->t_inpcb->inp_socket->so_options & SO_KEEPALIVE) && - tp->t_state <= TCPS_CLOSING) { - if (tp->t_idle >= tcp_keepidle + 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. - */ - tcpstat.tcps_keepprobe++; -#ifdef TCP_COMPAT_42 - /* - * The keepalive packet must have nonzero length - * to get a 4.2 host to respond. - */ - tcp_respond(tp, tp->t_template, (struct mbuf *)NULL, - tp->rcv_nxt - 1, tp->snd_una - 1, 0); -#else - tcp_respond(tp, tp->t_template, (struct mbuf *)NULL, - tp->rcv_nxt, tp->snd_una - 1, 0); -#endif - tp->t_timer[TCPT_KEEP] = tcp_keepintvl; - } else - tp->t_timer[TCPT_KEEP] = tcp_keepidle; - break; - dropit: - tcpstat.tcps_keepdrops++; - tp = tcp_drop(tp, ETIMEDOUT); - break; - } - return (tp); -} -#endif /* TUBA_INCLUDE */ |