Commit | Line | Data |
---|---|---|
8ae0e4b4 KM |
1 | /* |
2 | * Copyright (c) 1982 Regents of the University of California. | |
3 | * All rights reserved. The Berkeley software License Agreement | |
4 | * specifies the terms and conditions for redistribution. | |
5 | * | |
2ba2de86 | 6 | * @(#)tcp_timer.c 6.9 (Berkeley) %G% |
8ae0e4b4 | 7 | */ |
f03530e6 | 8 | |
20666ad3 JB |
9 | #include "param.h" |
10 | #include "systm.h" | |
11 | #include "mbuf.h" | |
12 | #include "socket.h" | |
13 | #include "socketvar.h" | |
14 | #include "protosw.h" | |
15 | #include "errno.h" | |
6e7edb25 BJ |
16 | |
17 | #include "../net/if.h" | |
c124e997 | 18 | #include "../net/route.h" |
f4d55810 | 19 | |
20666ad3 JB |
20 | #include "in.h" |
21 | #include "in_pcb.h" | |
22 | #include "in_systm.h" | |
23 | #include "ip.h" | |
24 | #include "ip_var.h" | |
25 | #include "tcp.h" | |
26 | #include "tcp_fsm.h" | |
27 | #include "tcp_seq.h" | |
28 | #include "tcp_timer.h" | |
29 | #include "tcp_var.h" | |
30 | #include "tcpip.h" | |
f03530e6 | 31 | |
8b5a83bb | 32 | int tcpnodelack = 0; |
f03530e6 BJ |
33 | /* |
34 | * Fast timeout routine for processing delayed acks | |
35 | */ | |
36 | tcp_fasttimo() | |
37 | { | |
b8b9174f BJ |
38 | register struct inpcb *inp; |
39 | register struct tcpcb *tp; | |
40 | int s = splnet(); | |
b8b9174f | 41 | |
fd5dc5f0 BJ |
42 | inp = tcb.inp_next; |
43 | if (inp) | |
44 | for (; inp != &tcb; inp = inp->inp_next) | |
b8b9174f BJ |
45 | if ((tp = (struct tcpcb *)inp->inp_ppcb) && |
46 | (tp->t_flags & TF_DELACK)) { | |
47 | tp->t_flags &= ~TF_DELACK; | |
48 | tp->t_flags |= TF_ACKNOW; | |
49 | (void) tcp_output(tp); | |
50 | } | |
51 | splx(s); | |
f03530e6 BJ |
52 | } |
53 | ||
54 | /* | |
55 | * Tcp protocol timeout routine called every 500 ms. | |
56 | * Updates the timers in all active tcb's and | |
57 | * causes finite state machine actions if timers expire. | |
58 | */ | |
59 | tcp_slowtimo() | |
60 | { | |
1e977657 | 61 | register struct inpcb *ip, *ipnxt; |
f03530e6 BJ |
62 | register struct tcpcb *tp; |
63 | int s = splnet(); | |
f03530e6 | 64 | register int i; |
f03530e6 BJ |
65 | |
66 | /* | |
67 | * Search through tcb's and update active timers. | |
68 | */ | |
4aed14e3 BJ |
69 | ip = tcb.inp_next; |
70 | if (ip == 0) { | |
71 | splx(s); | |
72 | return; | |
73 | } | |
039b88d5 MK |
74 | for (; ip != &tcb; ip = ipnxt) { |
75 | ipnxt = ip->inp_next; | |
f03530e6 | 76 | tp = intotcpcb(ip); |
37de812c BJ |
77 | if (tp == 0) |
78 | continue; | |
a6503abf | 79 | for (i = 0; i < TCPT_NTIMERS; i++) { |
1e977657 | 80 | if (tp->t_timer[i] && --tp->t_timer[i] == 0) { |
f03530e6 BJ |
81 | (void) tcp_usrreq(tp->t_inpcb->inp_socket, |
82 | PRU_SLOWTIMO, (struct mbuf *)0, | |
755d8841 | 83 | (struct mbuf *)i, (struct mbuf *)0); |
1e977657 BJ |
84 | if (ipnxt->inp_prev != ip) |
85 | goto tpgone; | |
86 | } | |
f03530e6 | 87 | } |
405c9168 BJ |
88 | tp->t_idle++; |
89 | if (tp->t_rtt) | |
90 | tp->t_rtt++; | |
1e977657 | 91 | tpgone: |
039b88d5 | 92 | ; |
f03530e6 | 93 | } |
a6503abf | 94 | tcp_iss += TCP_ISSINCR/PR_SLOWHZ; /* increment iss */ |
f03530e6 BJ |
95 | splx(s); |
96 | } | |
97 | ||
98 | /* | |
a6503abf | 99 | * Cancel all timers for TCP tp. |
f03530e6 | 100 | */ |
0974b45c | 101 | tcp_canceltimers(tp) |
f03530e6 BJ |
102 | struct tcpcb *tp; |
103 | { | |
f03530e6 BJ |
104 | register int i; |
105 | ||
a6503abf BJ |
106 | for (i = 0; i < TCPT_NTIMERS; i++) |
107 | tp->t_timer[i] = 0; | |
f03530e6 BJ |
108 | } |
109 | ||
7380f986 | 110 | float tcp_backoff[TCP_MAXRXTSHIFT] = |
6209c5c4 | 111 | { 1.0, 1.2, 1.4, 1.7, 2.0, 3.0, 5.0, 8.0, 16.0, 32.0, 32.0, 32.0 }; |
7380f986 | 112 | int tcpexprexmtbackoff = 0; |
f03530e6 | 113 | /* |
405c9168 | 114 | * TCP timer processing. |
f03530e6 | 115 | */ |
0e3936fa | 116 | struct tcpcb * |
a6503abf | 117 | tcp_timers(tp, timer) |
f03530e6 | 118 | register struct tcpcb *tp; |
a6503abf | 119 | int timer; |
f03530e6 BJ |
120 | { |
121 | ||
0974b45c | 122 | switch (timer) { |
f03530e6 | 123 | |
405c9168 | 124 | /* |
6209c5c4 MK |
125 | * 2 MSL timeout in shutdown went off. If we're closed but |
126 | * still waiting for peer to close and connection has been idle | |
127 | * too long, or if 2MSL time is up from TIME_WAIT, delete connection | |
128 | * control block. Otherwise, check again in a bit. | |
405c9168 | 129 | */ |
a6503abf | 130 | case TCPT_2MSL: |
6209c5c4 MK |
131 | if (tp->t_state != TCPS_TIME_WAIT && |
132 | tp->t_idle <= TCPTV_MAXIDLE) | |
133 | tp->t_timer[TCPT_2MSL] = TCPTV_KEEP; | |
134 | else | |
135 | tp = tcp_close(tp); | |
0e3936fa | 136 | break; |
f03530e6 | 137 | |
405c9168 BJ |
138 | /* |
139 | * Retransmission timer went off. Message has not | |
140 | * been acked within retransmit interval. Back off | |
eeaf00e3 | 141 | * to a longer retransmit interval and retransmit one segment. |
405c9168 | 142 | */ |
a6503abf | 143 | case TCPT_REXMT: |
405c9168 | 144 | tp->t_rxtshift++; |
fd5dc5f0 | 145 | if (tp->t_rxtshift > TCP_MAXRXTSHIFT) { |
0e3936fa SL |
146 | tp = tcp_drop(tp, ETIMEDOUT); |
147 | break; | |
fd5dc5f0 | 148 | } |
eeaf00e3 MK |
149 | /* |
150 | * If losing, let the lower level know | |
151 | * and try for a better route. | |
152 | */ | |
6209c5c4 | 153 | if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 3) |
2ba2de86 | 154 | in_losing(tp->t_inpcb); |
405c9168 | 155 | TCPT_RANGESET(tp->t_timer[TCPT_REXMT], |
d977a479 | 156 | (int)tp->t_srtt, TCPTV_MIN, TCPTV_MAX); |
7380f986 BJ |
157 | if (tcpexprexmtbackoff) { |
158 | TCPT_RANGESET(tp->t_timer[TCPT_REXMT], | |
159 | tp->t_timer[TCPT_REXMT] << tp->t_rxtshift, | |
160 | TCPTV_MIN, TCPTV_MAX); | |
161 | } else { | |
162 | TCPT_RANGESET(tp->t_timer[TCPT_REXMT], | |
163 | tp->t_timer[TCPT_REXMT] * | |
164 | tcp_backoff[tp->t_rxtshift - 1], | |
165 | TCPTV_MIN, TCPTV_MAX); | |
166 | } | |
405c9168 | 167 | tp->snd_nxt = tp->snd_una; |
7872cc0a | 168 | /* |
f2da4d39 MK |
169 | * If timing a segment in this window, |
170 | * and we have already gotten some timing estimate, | |
171 | * stop the timer. | |
7872cc0a | 172 | */ |
f2da4d39 | 173 | if (tp->t_rtt && tp->t_srtt) |
7872cc0a | 174 | tp->t_rtt = 0; |
405c9168 | 175 | (void) tcp_output(tp); |
0e3936fa | 176 | break; |
f03530e6 | 177 | |
405c9168 BJ |
178 | /* |
179 | * Persistance timer into zero window. | |
180 | * Force a byte to be output, if possible. | |
181 | */ | |
a6503abf | 182 | case TCPT_PERSIST: |
a13c006d | 183 | tcp_setpersist(tp); |
405c9168 BJ |
184 | tp->t_force = 1; |
185 | (void) tcp_output(tp); | |
186 | tp->t_force = 0; | |
0e3936fa | 187 | break; |
f03530e6 | 188 | |
405c9168 BJ |
189 | /* |
190 | * Keep-alive timer went off; send something | |
191 | * or drop connection if idle for too long. | |
192 | */ | |
a6503abf | 193 | case TCPT_KEEP: |
f3cdd721 BJ |
194 | if (tp->t_state < TCPS_ESTABLISHED) |
195 | goto dropit; | |
3bd14c98 | 196 | if (tp->t_inpcb->inp_socket->so_options & SO_KEEPALIVE) { |
f3cdd721 BJ |
197 | if (tp->t_idle >= TCPTV_MAXIDLE) |
198 | goto dropit; | |
3bd14c98 BJ |
199 | /* |
200 | * Saying tp->rcv_nxt-1 lies about what | |
201 | * we have received, and by the protocol spec | |
202 | * requires the correspondent TCP to respond. | |
203 | * Saying tp->snd_una-1 causes the transmitted | |
204 | * byte to lie outside the receive window; this | |
205 | * is important because we don't necessarily | |
206 | * have a byte in the window to send (consider | |
207 | * a one-way stream!) | |
208 | */ | |
8e65fd66 | 209 | tcp_respond(tp, |
3bd14c98 BJ |
210 | tp->t_template, tp->rcv_nxt-1, tp->snd_una-1, 0); |
211 | } else | |
1e977657 | 212 | tp->t_idle = 0; |
405c9168 | 213 | tp->t_timer[TCPT_KEEP] = TCPTV_KEEP; |
0e3936fa | 214 | break; |
f3cdd721 | 215 | dropit: |
0e3936fa SL |
216 | tp = tcp_drop(tp, ETIMEDOUT); |
217 | break; | |
f03530e6 | 218 | } |
0e3936fa | 219 | return (tp); |
f03530e6 | 220 | } |