Check for SYS/GL during library init. Reason is that
[AROS.git] / workbench / network / stacks / AROSTCP / bsdsocket / netinet / tcp_timer.c
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1 /*
2 * Copyright (c) 1982, 1986, 1988, 1990, 1993
3 * The Regents of the University of California. All rights reserved.
4 * Copyright (c) 2006
5 * Pavel Fedin
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by the University of
18 * California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
35 * @(#)tcp_timer.c 8.1 (Berkeley) 6/10/93
36 * $Id$
39 #ifndef TUBA_INCLUDE
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/malloc.h>
43 #include <sys/mbuf.h>
44 #include <sys/socket.h>
45 #include <sys/socketvar.h>
46 #include <sys/protosw.h>
47 #include <sys/errno.h>
48 #include <sys/queue.h>
49 #include <sys/synch.h>
51 #include <net/route.h>
52 #include <net/if.h>
54 #include <netinet/in.h>
55 #include <netinet/in_systm.h>
56 #include <netinet/ip.h>
57 #include <netinet/in_pcb.h>
58 #include <netinet/ip_var.h>
59 #include <netinet/tcp.h>
60 #include <netinet/tcp_fsm.h>
61 #include <netinet/tcp_seq.h>
62 #include <netinet/tcp_timer.h>
63 #include <netinet/tcp_var.h>
64 #include <netinet/tcpip.h>
66 int tcp_keepidle = TCPTV_KEEP_IDLE;
67 int tcp_keepintvl = TCPTV_KEEPINTVL;
68 int tcp_maxidle;
69 #endif /* TUBA_INCLUDE */
71 * Fast timeout routine for processing delayed acks
73 void
74 tcp_fasttimo()
76 register struct inpcb *inp;
77 register struct tcpcb *tp;
78 int s;
80 s = splnet();
82 for (inp = tcb.lh_first; inp != NULL; inp = inp->inp_list.le_next) {
83 if ((tp = (struct tcpcb *)inp->inp_ppcb) &&
84 (tp->t_flags & TF_DELACK)) {
85 tp->t_flags &= ~TF_DELACK;
86 tp->t_flags |= TF_ACKNOW;
87 tcpstat.tcps_delack++;
88 (void) tcp_output(tp);
91 splx(s);
95 * Tcp protocol timeout routine called every 500 ms.
96 * Updates the timers in all active tcb's and
97 * causes finite state machine actions if timers expire.
99 void
100 tcp_slowtimo()
102 register struct inpcb *ip, *ipnxt;
103 register struct tcpcb *tp;
104 register long i;
105 int s;
107 s = splnet();
109 tcp_maxidle = TCPTV_KEEPCNT * tcp_keepintvl;
111 ip = tcb.lh_first;
112 if (ip == NULL) {
113 splx(s);
114 return;
117 * Search through tcb's and update active timers.
119 for (; ip != NULL; ip = ipnxt) {
120 ipnxt = ip->inp_list.le_next;
121 tp = intotcpcb(ip);
122 if (tp == 0)
123 continue;
124 for (i = 0; i < TCPT_NTIMERS; i++) {
125 if (tp->t_timer[i] && --tp->t_timer[i] == 0) {
126 if (tcp_usrreq(tp->t_inpcb->inp_socket,
127 PRU_SLOWTIMO, (struct mbuf *)0,
128 (struct mbuf *)i, (struct mbuf *)0) == 0)
129 goto tpgone;
132 tp->t_idle++;
133 tp->t_duration++;
134 if (tp->t_rtt)
135 tp->t_rtt++;
136 tpgone:
139 tcp_iss += TCP_ISSINCR/PR_SLOWHZ; /* increment iss */
140 #ifdef TCP_COMPAT_42
141 if ((int)tcp_iss < 0)
142 tcp_iss = 0; /* XXX */
143 #endif
144 tcp_now++; /* for timestamps */
145 splx(s);
147 #ifndef TUBA_INCLUDE
150 * Cancel all timers for TCP tp.
152 void
153 tcp_canceltimers(tp)
154 struct tcpcb *tp;
156 register int i;
158 for (i = 0; i < TCPT_NTIMERS; i++)
159 tp->t_timer[i] = 0;
162 int tcp_backoff[TCP_MAXRXTSHIFT + 1] =
163 { 1, 2, 4, 8, 16, 32, 64, 64, 64, 64, 64, 64, 64 };
166 * TCP timer processing.
168 struct tcpcb *
169 tcp_timers(tp, timer)
170 register struct tcpcb *tp;
171 int timer;
173 register int rexmt;
175 switch (timer) {
178 * 2 MSL timeout in shutdown went off. If we're closed but
179 * still waiting for peer to close and connection has been idle
180 * too long, or if 2MSL time is up from TIME_WAIT, delete connection
181 * control block. Otherwise, check again in a bit.
183 case TCPT_2MSL:
184 if (tp->t_state != TCPS_TIME_WAIT &&
185 tp->t_idle <= tcp_maxidle)
186 tp->t_timer[TCPT_2MSL] = tcp_keepintvl;
187 else
188 tp = tcp_close(tp);
189 break;
192 * Retransmission timer went off. Message has not
193 * been acked within retransmit interval. Back off
194 * to a longer retransmit interval and retransmit one segment.
196 case TCPT_REXMT:
197 if (++tp->t_rxtshift > TCP_MAXRXTSHIFT) {
198 tp->t_rxtshift = TCP_MAXRXTSHIFT;
199 tcpstat.tcps_timeoutdrop++;
200 tp = tcp_drop(tp, tp->t_softerror ?
201 tp->t_softerror : ETIMEDOUT);
202 break;
204 tcpstat.tcps_rexmttimeo++;
205 rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift];
206 TCPT_RANGESET(tp->t_rxtcur, rexmt,
207 tp->t_rttmin, TCPTV_REXMTMAX);
208 tp->t_timer[TCPT_REXMT] = tp->t_rxtcur;
210 * If losing, let the lower level know and try for
211 * a better route. Also, if we backed off this far,
212 * our srtt estimate is probably bogus. Clobber it
213 * so we'll take the next rtt measurement as our srtt;
214 * move the current srtt into rttvar to keep the current
215 * retransmit times until then.
217 if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
218 in_losing(tp->t_inpcb);
219 tp->t_rttvar += (tp->t_srtt >> TCP_RTT_SHIFT);
220 tp->t_srtt = 0;
222 tp->snd_nxt = tp->snd_una;
224 * Force a segment to be sent.
226 tp->t_flags |= TF_ACKNOW;
228 * If timing a segment in this window, stop the timer.
230 tp->t_rtt = 0;
232 * Close the congestion window down to one segment
233 * (we'll open it by one segment for each ack we get).
234 * Since we probably have a window's worth of unacked
235 * data accumulated, this "slow start" keeps us from
236 * dumping all that data as back-to-back packets (which
237 * might overwhelm an intermediate gateway).
239 * There are two phases to the opening: Initially we
240 * open by one mss on each ack. This makes the window
241 * size increase exponentially with time. If the
242 * window is larger than the path can handle, this
243 * exponential growth results in dropped packet(s)
244 * almost immediately. To get more time between
245 * drops but still "push" the network to take advantage
246 * of improving conditions, we switch from exponential
247 * to linear window opening at some threshhold size.
248 * For a threshhold, we use half the current window
249 * size, truncated to a multiple of the mss.
251 * (the minimum cwnd that will give us exponential
252 * growth is 2 mss. We don't allow the threshhold
253 * to go below this.)
256 u_int win = MIN(tp->snd_wnd, tp->snd_cwnd) / 2 / tp->t_maxseg;
257 if (win < 2)
258 win = 2;
259 tp->snd_cwnd = tp->t_maxseg;
260 tp->snd_ssthresh = win * tp->t_maxseg;
261 tp->t_dupacks = 0;
263 (void) tcp_output(tp);
264 break;
267 * Persistance timer into zero window.
268 * Force a byte to be output, if possible.
270 case TCPT_PERSIST:
271 tcpstat.tcps_persisttimeo++;
272 tcp_setpersist(tp);
273 tp->t_force = 1;
274 (void) tcp_output(tp);
275 tp->t_force = 0;
276 break;
279 * Keep-alive timer went off; send something
280 * or drop connection if idle for too long.
282 case TCPT_KEEP:
283 tcpstat.tcps_keeptimeo++;
284 if (tp->t_state < TCPS_ESTABLISHED)
285 goto dropit;
286 if (tp->t_inpcb->inp_socket->so_options & SO_KEEPALIVE &&
287 tp->t_state <= TCPS_CLOSE_WAIT) {
288 if (tp->t_idle >= tcp_keepidle + tcp_maxidle)
289 goto dropit;
291 * Send a packet designed to force a response
292 * if the peer is up and reachable:
293 * either an ACK if the connection is still alive,
294 * or an RST if the peer has closed the connection
295 * due to timeout or reboot.
296 * Using sequence number tp->snd_una-1
297 * causes the transmitted zero-length segment
298 * to lie outside the receive window;
299 * by the protocol spec, this requires the
300 * correspondent TCP to respond.
302 tcpstat.tcps_keepprobe++;
303 #ifdef TCP_COMPAT_42
305 * The keepalive packet must have nonzero length
306 * to get a 4.2 host to respond.
308 tcp_respond(tp, tp->t_template, (struct mbuf *)NULL,
309 tp->rcv_nxt - 1, tp->snd_una - 1, 0);
310 #else
311 tcp_respond(tp, tp->t_template, (struct mbuf *)NULL,
312 tp->rcv_nxt, tp->snd_una - 1, 0);
313 #endif
314 tp->t_timer[TCPT_KEEP] = tcp_keepintvl;
315 } else
316 tp->t_timer[TCPT_KEEP] = tcp_keepidle;
317 break;
318 dropit:
319 tcpstat.tcps_keepdrops++;
320 tp = tcp_drop(tp, ETIMEDOUT);
321 break;
323 return (tp);
325 #endif /* TUBA_INCLUDE */