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4a10c08d KS |
1 | /* |
2 | * Copyright (c) 1985 Regents of the University of California. | |
3 | * All rights reserved. The Berkeley software License Agreement | |
4 | * specifies the terms and conditions for redistribution. | |
5 | * | |
6 | * Includes material written at Cornell University by Bill Nesheim, | |
7 | * by permission of the author. | |
8 | */ | |
9 | ||
10 | ||
5474cc46 | 11 | #ifndef lint |
84f93e8f | 12 | static char sccsid[] = "@(#)timer.c 5.4 (Berkeley) %G%"; |
4a10c08d | 13 | #endif not lint |
5474cc46 KS |
14 | |
15 | /* | |
16 | * Routing Table Management Daemon | |
17 | */ | |
18 | #include "defs.h" | |
19 | ||
20 | int timeval = -TIMER_RATE; | |
21 | ||
22 | /* | |
23 | * Timer routine. Performs routing information supply | |
24 | * duties and manages timers on routing table entries. | |
25 | */ | |
26 | timer() | |
27 | { | |
28 | register struct rthash *rh; | |
29 | register struct rt_entry *rt; | |
30 | struct rthash *base = hosthash; | |
31 | int doinghost = 1, timetobroadcast; | |
32 | ||
33 | timeval += TIMER_RATE; | |
34 | if (lookforinterfaces && (timeval % CHECK_INTERVAL) == 0) | |
35 | ifinit(); | |
36 | timetobroadcast = supplier && (timeval % SUPPLY_INTERVAL) == 0; | |
37 | again: | |
38 | for (rh = base; rh < &base[ROUTEHASHSIZ]; rh++) { | |
39 | rt = rh->rt_forw; | |
40 | for (; rt != (struct rt_entry *)rh; rt = rt->rt_forw) { | |
41 | /* | |
42 | * We don't advance time on a routing entry for | |
43 | * a passive gateway or that for our only interface. | |
44 | * The latter is excused because we don't act as | |
45 | * a routing information supplier and hence would | |
46 | * time it out. This is fair as if it's down | |
47 | * we're cut off from the world anyway and it's | |
48 | * not likely we'll grow any new hardware in | |
49 | * the mean time. | |
50 | */ | |
51 | if (!(rt->rt_state & RTS_PASSIVE) && | |
52 | (supplier || !(rt->rt_state & RTS_INTERFACE))) | |
53 | rt->rt_timer += TIMER_RATE; | |
54 | if (rt->rt_timer >= EXPIRE_TIME) | |
55 | rt->rt_metric = HOPCNT_INFINITY; | |
56 | if (rt->rt_timer >= GARBAGE_TIME) { | |
57 | rt = rt->rt_back; | |
58 | /* Perhaps we should send a REQUEST for this route? */ | |
59 | rtdelete(rt->rt_forw); | |
60 | continue; | |
61 | } | |
62 | if (rt->rt_state & RTS_CHANGED) { | |
63 | rt->rt_state &= ~RTS_CHANGED; | |
64 | /* don't send extraneous packets */ | |
65 | if (!supplier || timetobroadcast) | |
66 | continue; | |
67 | msg->rip_cmd = htons(RIPCMD_RESPONSE); | |
84f93e8f KS |
68 | msg->rip_nets[0].rip_dst = |
69 | (satons_addr(rt->rt_dst)).x_net; | |
5474cc46 KS |
70 | msg->rip_nets[0].rip_metric = |
71 | htons(min(rt->rt_metric+1, HOPCNT_INFINITY)); | |
72 | toall(sendmsg); | |
73 | } | |
74 | } | |
75 | } | |
76 | if (doinghost) { | |
77 | doinghost = 0; | |
78 | base = nethash; | |
79 | goto again; | |
80 | } | |
81 | if (timetobroadcast) | |
82 | toall(supply); | |
83 | alarm(TIMER_RATE); | |
84 | } | |
85 | ||
86 | /* | |
87 | * On hangup, let everyone know we're going away. | |
88 | */ | |
89 | hup() | |
90 | { | |
91 | register struct rthash *rh; | |
92 | register struct rt_entry *rt; | |
93 | struct rthash *base = hosthash; | |
94 | int doinghost = 1; | |
95 | ||
96 | if (supplier) { | |
97 | again: | |
98 | for (rh = base; rh < &base[ROUTEHASHSIZ]; rh++) { | |
99 | rt = rh->rt_forw; | |
100 | for (; rt != (struct rt_entry *)rh; rt = rt->rt_forw) | |
101 | rt->rt_metric = HOPCNT_INFINITY; | |
102 | } | |
103 | if (doinghost) { | |
104 | doinghost = 0; | |
105 | base = nethash; | |
106 | goto again; | |
107 | } | |
108 | toall(supply); | |
109 | } | |
110 | exit(1); | |
111 | } |