xref: /csrg-svn/sys/netinet/tcp_timer.c (revision 5089)
1 /* tcp_timer.c 4.3 81/11/26 */
2 
3 #include "../h/param.h"
4 #include "../h/systm.h"
5 #include "../h/mbuf.h"
6 #include "../h/socket.h"
7 #include "../h/socketvar.h"
8 #include "../h/protosw.h"
9 #include "../net/in.h"
10 #include "../net/in_pcb.h"
11 #include "../net/in_systm.h"
12 #include "../net/if.h"
13 #include "../net/ip.h"
14 #include "../net/ip_var.h"
15 #include "../net/tcp.h"
16 #include "../net/tcp_fsm.h"
17 #include "../net/tcp_seq.h"
18 #include "../net/tcp_timer.h"
19 #include "../net/tcp_var.h"
20 #include "../net/tcpip.h"
21 #include "/usr/include/errno.h"
22 
23 /*
24  * Fast timeout routine for processing delayed acks
25  */
26 tcp_fasttimo()
27 {
28 
29 COUNT(TCP_FASTTIMO);
30 }
31 
32 /*
33  * Tcp protocol timeout routine called every 500 ms.
34  * Updates the timers in all active tcb's and
35  * causes finite state machine actions if timers expire.
36  */
37 tcp_slowtimo()
38 {
39 	register struct inpcb *ip;
40 	register struct tcpcb *tp;
41 	int s = splnet();
42 	register short *tmp;
43 	register int i;
44 COUNT(TCP_SLOWTIMO);
45 
46 	/*
47 	 * Search through tcb's and update active timers.
48 	 */
49 	for (ip = tcb.inp_next; ip != &tcb; ip = ip->inp_next) {
50 		tp = intotcpcb(ip);
51 		for (i = 0; i < TCPT_NTIMERS; i++) {
52 			if (tp->t_timer[i] && --tp->t_timer[i] == 0)
53 				(void) tcp_usrreq(tp->t_inpcb->inp_socket,
54 				    PRU_SLOWTIMO, (struct mbuf *)0,
55 				    (caddr_t)i);
56 			tmp++;
57 		}
58 	}
59 	tcp_iss += TCP_ISSINCR/PR_SLOWHZ;		/* increment iss */
60 	splx(s);
61 }
62 
63 /*
64  * Cancel all timers for TCP tp.
65  */
66 tcp_canceltimers(tp)
67 	struct tcpcb *tp;
68 {
69 	register int i;
70 
71 COUNT(TCP_CANCELTIMERS);
72 	for (i = 0; i < TCPT_NTIMERS; i++)
73 		tp->t_timer[i] = 0;
74 }
75 
76 /*
77  * TCP timer went off processing.
78  */
79 tcp_timers(tp, timer)
80 	register struct tcpcb *tp;
81 	int timer;
82 {
83 
84 COUNT(TCP_TIMERS);
85 	switch (timer) {
86 
87 	case TCPT_2MSL:
88 		tcp_close(tp);
89 		return;
90 
91 	case TCPT_REXMT:
92 #if 0
93 		tp->t_xmtime <<= 1;
94 		if (tp->t_xmtime > TCPSC_TOOLONG) {
95 			tcp_drop(tp, ETIMEDOUT);
96 			return;
97 		}
98 #endif
99 		tcp_output(tp);
100 		return;
101 
102 	case TCPT_PERSIST:
103 		if (tcp_output(tp) == 0)
104 			tp->snd_wnd++, (void) tcp_output(tp), tp->snd_wnd--;
105 		/* reset? */
106 		return;
107 
108 	case TCPT_KEEP:
109 		/* reset? */
110 		return;
111 	}
112 }
113