projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 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 | } |