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4a10c08d | 1 | /* |
632d8116 KB |
2 | * Copyright (c) 1985, 1993 |
3 | * The Regents of the University of California. All rights reserved. | |
4a10c08d | 4 | * |
3565c602 KB |
5 | * This file includes significant work done at Cornell University by |
6 | * Bill Nesheim. That work included by permission. | |
7 | * | |
6ecf3d85 | 8 | * %sccs.include.redist.c% |
4a10c08d KS |
9 | */ |
10 | ||
5474cc46 | 11 | #ifndef lint |
632d8116 | 12 | static char sccsid[] = "@(#)timer.c 8.1 (Berkeley) %G%"; |
3565c602 | 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 | */ | |
b6a2f0a4 | 26 | void |
5474cc46 KS |
27 | timer() |
28 | { | |
29 | register struct rthash *rh; | |
30 | register struct rt_entry *rt; | |
31 | struct rthash *base = hosthash; | |
32 | int doinghost = 1, timetobroadcast; | |
33 | ||
34 | timeval += TIMER_RATE; | |
35 | if (lookforinterfaces && (timeval % CHECK_INTERVAL) == 0) | |
36 | ifinit(); | |
37 | timetobroadcast = supplier && (timeval % SUPPLY_INTERVAL) == 0; | |
38 | again: | |
39 | for (rh = base; rh < &base[ROUTEHASHSIZ]; rh++) { | |
40 | rt = rh->rt_forw; | |
41 | for (; rt != (struct rt_entry *)rh; rt = rt->rt_forw) { | |
42 | /* | |
43 | * We don't advance time on a routing entry for | |
44 | * a passive gateway or that for our only interface. | |
45 | * The latter is excused because we don't act as | |
46 | * a routing information supplier and hence would | |
47 | * time it out. This is fair as if it's down | |
48 | * we're cut off from the world anyway and it's | |
49 | * not likely we'll grow any new hardware in | |
50 | * the mean time. | |
51 | */ | |
52 | if (!(rt->rt_state & RTS_PASSIVE) && | |
53 | (supplier || !(rt->rt_state & RTS_INTERFACE))) | |
54 | rt->rt_timer += TIMER_RATE; | |
55 | if (rt->rt_timer >= EXPIRE_TIME) | |
56 | rt->rt_metric = HOPCNT_INFINITY; | |
57 | if (rt->rt_timer >= GARBAGE_TIME) { | |
58 | rt = rt->rt_back; | |
59 | /* Perhaps we should send a REQUEST for this route? */ | |
60 | rtdelete(rt->rt_forw); | |
61 | continue; | |
62 | } | |
63 | if (rt->rt_state & RTS_CHANGED) { | |
64 | rt->rt_state &= ~RTS_CHANGED; | |
65 | /* don't send extraneous packets */ | |
66 | if (!supplier || timetobroadcast) | |
67 | continue; | |
68 | msg->rip_cmd = htons(RIPCMD_RESPONSE); | |
84f93e8f KS |
69 | msg->rip_nets[0].rip_dst = |
70 | (satons_addr(rt->rt_dst)).x_net; | |
5474cc46 KS |
71 | msg->rip_nets[0].rip_metric = |
72 | htons(min(rt->rt_metric+1, HOPCNT_INFINITY)); | |
b6a2f0a4 | 73 | toall(sndmsg); |
5474cc46 KS |
74 | } |
75 | } | |
76 | } | |
77 | if (doinghost) { | |
78 | doinghost = 0; | |
79 | base = nethash; | |
80 | goto again; | |
81 | } | |
82 | if (timetobroadcast) | |
83 | toall(supply); | |
84 | alarm(TIMER_RATE); | |
85 | } | |
86 | ||
87 | /* | |
88 | * On hangup, let everyone know we're going away. | |
89 | */ | |
b6a2f0a4 | 90 | void |
5474cc46 KS |
91 | hup() |
92 | { | |
93 | register struct rthash *rh; | |
94 | register struct rt_entry *rt; | |
95 | struct rthash *base = hosthash; | |
96 | int doinghost = 1; | |
97 | ||
98 | if (supplier) { | |
99 | again: | |
100 | for (rh = base; rh < &base[ROUTEHASHSIZ]; rh++) { | |
101 | rt = rh->rt_forw; | |
102 | for (; rt != (struct rt_entry *)rh; rt = rt->rt_forw) | |
103 | rt->rt_metric = HOPCNT_INFINITY; | |
104 | } | |
105 | if (doinghost) { | |
106 | doinghost = 0; | |
107 | base = nethash; | |
108 | goto again; | |
109 | } | |
110 | toall(supply); | |
111 | } | |
112 | exit(1); | |
113 | } |