projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 5919db1b SL |
1 | #ifndef lint |
| 2 | static char sccsid[] = "@(#)timer.c 4.1 %G%"; | |
| 3 | #endif | |
| 4 | ||
| 5 | /* | |
| 6 | * Routing Table Management Daemon | |
| 7 | */ | |
| 8 | #include "router.h" | |
| 9 | ||
| 10 | int timeval = -TIMER_RATE; | |
| 11 | ||
| 12 | /* | |
| 13 | * Timer routine. Performs routing information supply | |
| 14 | * duties and manages timers on routing table entries. | |
| 15 | */ | |
| 16 | timer() | |
| 17 | { | |
| 18 | register struct rthash *rh; | |
| 19 | register struct rt_entry *rt; | |
| 20 | struct rthash *base = hosthash; | |
| 21 | int doinghost = 1, timetobroadcast; | |
| 22 | ||
| 23 | timeval += TIMER_RATE; | |
| 24 | if (lookforinterfaces && (timeval % CHECK_INTERVAL) == 0) | |
| 25 | ifinit(); | |
| 26 | timetobroadcast = supplier && (timeval % SUPPLY_INTERVAL) == 0; | |
| 27 | again: | |
| 28 | for (rh = base; rh < &base[ROUTEHASHSIZ]; rh++) { | |
| 29 | rt = rh->rt_forw; | |
| 30 | for (; rt != (struct rt_entry *)rh; rt = rt->rt_forw) { | |
| 31 | /* | |
| 32 | * We don't advance time on a routing entry for | |
| 33 | * a passive gateway or that for our only interface. | |
| 34 | * The latter is excused because we don't act as | |
| 35 | * a routing information supplier and hence would | |
| 36 | * time it out. This is fair as if it's down | |
| 37 | * we're cut off from the world anyway and it's | |
| 38 | * not likely we'll grow any new hardware in | |
| 39 | * the mean time. | |
| 40 | */ | |
| 41 | if (!(rt->rt_state & RTS_PASSIVE) && | |
| 42 | (supplier || !(rt->rt_state & RTS_INTERFACE))) | |
| 43 | rt->rt_timer += TIMER_RATE; | |
| 44 | if (rt->rt_timer >= EXPIRE_TIME) | |
| 45 | rt->rt_metric = HOPCNT_INFINITY; | |
| 46 | if (rt->rt_timer >= GARBAGE_TIME) { | |
| 47 | rt = rt->rt_back; | |
| 48 | rtdelete(rt->rt_forw); | |
| 49 | continue; | |
| 50 | } | |
| 51 | if (rt->rt_state & RTS_CHANGED) { | |
| 52 | rt->rt_state &= ~RTS_CHANGED; | |
| 53 | /* don't send extraneous packets */ | |
| 54 | if (!supplier || timetobroadcast) | |
| 55 | continue; | |
| 56 | msg->rip_cmd = RIPCMD_RESPONSE; | |
| 57 | msg->rip_nets[0].rip_dst = rt->rt_dst; | |
| 58 | msg->rip_nets[0].rip_metric = | |
| 59 | min(rt->rt_metric+1, HOPCNT_INFINITY); | |
| 60 | toall(sendmsg); | |
| 61 | } | |
| 62 | } | |
| 63 | } | |
| 64 | if (doinghost) { | |
| 65 | doinghost = 0; | |
| 66 | base = nethash; | |
| 67 | goto again; | |
| 68 | } | |
| 69 | if (timetobroadcast) | |
| 70 | toall(supply); | |
| 71 | alarm(TIMER_RATE); | |
| 72 | } |