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4a10c08d | 1 | /* |
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2 | * Copyright (c) 1985 The Regents of the University of California. |
3 | * All rights reserved. | |
4a10c08d | 4 | * |
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5 | * This file includes significant work done at Cornell University by |
6 | * Bill Nesheim. That work included by permission. | |
7 | * | |
8 | * Redistribution and use in source and binary forms are permitted | |
9 | * provided that the above copyright notice and this paragraph are | |
10 | * duplicated in all such forms and that any documentation, | |
11 | * advertising materials, and other materials related to such | |
12 | * distribution and use acknowledge that the software was developed | |
13 | * by the University of California, Berkeley. The name of the | |
14 | * University may not be used to endorse or promote products derived | |
15 | * from this software without specific prior written permission. | |
16 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR | |
17 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED | |
18 | * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. | |
4a10c08d KS |
19 | */ |
20 | ||
5474cc46 | 21 | #ifndef lint |
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22 | static char sccsid[] = "@(#)timer.c 5.5 (Berkeley) %G%"; |
23 | #endif /* not lint */ | |
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24 | |
25 | /* | |
26 | * Routing Table Management Daemon | |
27 | */ | |
28 | #include "defs.h" | |
29 | ||
30 | int timeval = -TIMER_RATE; | |
31 | ||
32 | /* | |
33 | * Timer routine. Performs routing information supply | |
34 | * duties and manages timers on routing table entries. | |
35 | */ | |
36 | timer() | |
37 | { | |
38 | register struct rthash *rh; | |
39 | register struct rt_entry *rt; | |
40 | struct rthash *base = hosthash; | |
41 | int doinghost = 1, timetobroadcast; | |
42 | ||
43 | timeval += TIMER_RATE; | |
44 | if (lookforinterfaces && (timeval % CHECK_INTERVAL) == 0) | |
45 | ifinit(); | |
46 | timetobroadcast = supplier && (timeval % SUPPLY_INTERVAL) == 0; | |
47 | again: | |
48 | for (rh = base; rh < &base[ROUTEHASHSIZ]; rh++) { | |
49 | rt = rh->rt_forw; | |
50 | for (; rt != (struct rt_entry *)rh; rt = rt->rt_forw) { | |
51 | /* | |
52 | * We don't advance time on a routing entry for | |
53 | * a passive gateway or that for our only interface. | |
54 | * The latter is excused because we don't act as | |
55 | * a routing information supplier and hence would | |
56 | * time it out. This is fair as if it's down | |
57 | * we're cut off from the world anyway and it's | |
58 | * not likely we'll grow any new hardware in | |
59 | * the mean time. | |
60 | */ | |
61 | if (!(rt->rt_state & RTS_PASSIVE) && | |
62 | (supplier || !(rt->rt_state & RTS_INTERFACE))) | |
63 | rt->rt_timer += TIMER_RATE; | |
64 | if (rt->rt_timer >= EXPIRE_TIME) | |
65 | rt->rt_metric = HOPCNT_INFINITY; | |
66 | if (rt->rt_timer >= GARBAGE_TIME) { | |
67 | rt = rt->rt_back; | |
68 | /* Perhaps we should send a REQUEST for this route? */ | |
69 | rtdelete(rt->rt_forw); | |
70 | continue; | |
71 | } | |
72 | if (rt->rt_state & RTS_CHANGED) { | |
73 | rt->rt_state &= ~RTS_CHANGED; | |
74 | /* don't send extraneous packets */ | |
75 | if (!supplier || timetobroadcast) | |
76 | continue; | |
77 | msg->rip_cmd = htons(RIPCMD_RESPONSE); | |
84f93e8f KS |
78 | msg->rip_nets[0].rip_dst = |
79 | (satons_addr(rt->rt_dst)).x_net; | |
5474cc46 KS |
80 | msg->rip_nets[0].rip_metric = |
81 | htons(min(rt->rt_metric+1, HOPCNT_INFINITY)); | |
82 | toall(sendmsg); | |
83 | } | |
84 | } | |
85 | } | |
86 | if (doinghost) { | |
87 | doinghost = 0; | |
88 | base = nethash; | |
89 | goto again; | |
90 | } | |
91 | if (timetobroadcast) | |
92 | toall(supply); | |
93 | alarm(TIMER_RATE); | |
94 | } | |
95 | ||
96 | /* | |
97 | * On hangup, let everyone know we're going away. | |
98 | */ | |
99 | hup() | |
100 | { | |
101 | register struct rthash *rh; | |
102 | register struct rt_entry *rt; | |
103 | struct rthash *base = hosthash; | |
104 | int doinghost = 1; | |
105 | ||
106 | if (supplier) { | |
107 | again: | |
108 | for (rh = base; rh < &base[ROUTEHASHSIZ]; rh++) { | |
109 | rt = rh->rt_forw; | |
110 | for (; rt != (struct rt_entry *)rh; rt = rt->rt_forw) | |
111 | rt->rt_metric = HOPCNT_INFINITY; | |
112 | } | |
113 | if (doinghost) { | |
114 | doinghost = 0; | |
115 | base = nethash; | |
116 | goto again; | |
117 | } | |
118 | toall(supply); | |
119 | } | |
120 | exit(1); | |
121 | } |