projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 2e74322d SL |
1 | #ifndef lint |
| 2 | static char sccsid[] = "@(#)input.c 4.1 %G%"; | |
| 3 | #endif | |
| 4 | ||
| 5 | /* | |
| 6 | * Routing Table Management Daemon | |
| 7 | */ | |
| 8 | #include "router.h" | |
| 9 | ||
| 10 | /* | |
| 11 | * Process a newly received packet. | |
| 12 | */ | |
| 13 | rip_input(from, size) | |
| 14 | struct sockaddr *from; | |
| 15 | int size; | |
| 16 | { | |
| 17 | struct rt_entry *rt; | |
| 18 | struct netinfo *n; | |
| 19 | struct interface *ifp; | |
| 20 | int newsize; | |
| 21 | struct afswitch *afp; | |
| 22 | ||
| 23 | ifp = 0; | |
| 24 | TRACE_INPUT(ifp, from, size); | |
| 25 | if (from->sa_family >= AF_MAX) | |
| 26 | return; | |
| 27 | afp = &afswitch[from->sa_family]; | |
| 28 | switch (msg->rip_cmd) { | |
| 29 | ||
| 30 | case RIPCMD_REQUEST: | |
| 31 | newsize = 0; | |
| 32 | size -= 4 * sizeof (char); | |
| 33 | n = msg->rip_nets; | |
| 34 | while (size > 0) { | |
| 35 | if (size < sizeof (struct netinfo)) | |
| 36 | break; | |
| 37 | size -= sizeof (struct netinfo); | |
| 38 | ||
| 39 | /* | |
| 40 | * A single entry with sa_family == AF_UNSPEC and | |
| 41 | * metric ``infinity'' means ``all routes''. | |
| 42 | */ | |
| 43 | if (n->rip_dst.sa_family == AF_UNSPEC && | |
| 44 | n->rip_metric == HOPCNT_INFINITY && size == 0) { | |
| 45 | supply(from, 0, ifp); | |
| 46 | return; | |
| 47 | } | |
| 48 | rt = rtlookup(&n->rip_dst); | |
| 49 | n->rip_metric = rt == 0 ? HOPCNT_INFINITY : | |
| 50 | min(rt->rt_metric+1, HOPCNT_INFINITY); | |
| 51 | n++, newsize += sizeof (struct netinfo); | |
| 52 | } | |
| 53 | if (newsize > 0) { | |
| 54 | msg->rip_cmd = RIPCMD_RESPONSE; | |
| 55 | newsize += sizeof (int); | |
| 56 | (*afp->af_output)(s, from, newsize); | |
| 57 | } | |
| 58 | return; | |
| 59 | ||
| 60 | case RIPCMD_TRACEON: | |
| 61 | case RIPCMD_TRACEOFF: | |
| 62 | /* verify message came from a priviledged port */ | |
| 63 | if ((*afp->af_portcheck)(from) == 0) | |
| 64 | return; | |
| 65 | packet[size] = '\0'; | |
| 66 | if (msg->rip_cmd == RIPCMD_TRACEON) | |
| 67 | traceon(msg->rip_tracefile); | |
| 68 | else | |
| 69 | traceoff(); | |
| 70 | return; | |
| 71 | ||
| 72 | case RIPCMD_RESPONSE: | |
| 73 | /* verify message came from a router */ | |
| 74 | if ((*afp->af_portmatch)(from) == 0) | |
| 75 | return; | |
| 76 | (*afp->af_canon)(from); | |
| 77 | /* are we talking to ourselves? */ | |
| 78 | ifp = if_ifwithaddr(from); | |
| 79 | if (ifp) { | |
| 80 | rt = rtfind(from); | |
| 81 | if (rt == 0) | |
| 82 | addrouteforif(ifp); | |
| 83 | else | |
| 84 | rt->rt_timer = 0; | |
| 85 | return; | |
| 86 | } | |
| 87 | size -= 4 * sizeof (char); | |
| 88 | n = msg->rip_nets; | |
| 89 | for (; size > 0; size -= sizeof (struct netinfo), n++) { | |
| 90 | if (size < sizeof (struct netinfo)) | |
| 91 | break; | |
| 92 | if (n->rip_metric >= HOPCNT_INFINITY) | |
| 93 | continue; | |
| 94 | rt = rtlookup(&n->rip_dst); | |
| 95 | if (rt == 0) { | |
| 96 | rtadd(&n->rip_dst, from, n->rip_metric, 0); | |
| 97 | continue; | |
| 98 | } | |
| 99 | ||
| 100 | /* | |
| 101 | * Update if from gateway, shorter, or getting | |
| 102 | * stale and equivalent. | |
| 103 | */ | |
| 104 | if (equal(from, &rt->rt_router) || | |
| 105 | n->rip_metric < rt->rt_metric || | |
| 106 | (rt->rt_timer > (EXPIRE_TIME/2) && | |
| 107 | rt->rt_metric == n->rip_metric)) { | |
| 108 | rtchange(rt, from, n->rip_metric); | |
| 109 | rt->rt_timer = 0; | |
| 110 | } | |
| 111 | } | |
| 112 | return; | |
| 113 | } | |
| 114 | } |