| | 1 | #ifndef lint |
| | 2 | static char sccsid[] = "@(#)input.c 4.9 (Berkeley) %G%"; |
| | 3 | #endif |
| | 4 | |
| | 5 | /* |
| | 6 | * Routing Table Management Daemon |
| | 7 | */ |
| | 8 | #include "defs.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 | if (msg->rip_vers > 0) { |
| | 40 | n->rip_dst.sa_family = |
| | 41 | ntohs(n->rip_dst.sa_family); |
| | 42 | n->rip_metric = ntohl(n->rip_metric); |
| | 43 | } |
| | 44 | /* |
| | 45 | * A single entry with sa_family == AF_UNSPEC and |
| | 46 | * metric ``infinity'' means ``all routes''. |
| | 47 | */ |
| | 48 | if (n->rip_dst.sa_family == AF_UNSPEC && |
| | 49 | n->rip_metric == HOPCNT_INFINITY && size == 0) { |
| | 50 | supply(from, 0, ifp); |
| | 51 | return; |
| | 52 | } |
| | 53 | rt = rtlookup(&n->rip_dst); |
| | 54 | n->rip_metric = rt == 0 ? HOPCNT_INFINITY : |
| | 55 | min(rt->rt_metric+1, HOPCNT_INFINITY); |
| | 56 | if (msg->rip_vers > 0) { |
| | 57 | n->rip_dst.sa_family = |
| | 58 | htons(n->rip_dst.sa_family); |
| | 59 | n->rip_metric = htonl(n->rip_metric); |
| | 60 | } |
| | 61 | n++, newsize += sizeof (struct netinfo); |
| | 62 | } |
| | 63 | if (newsize > 0) { |
| | 64 | msg->rip_cmd = RIPCMD_RESPONSE; |
| | 65 | newsize += sizeof (int); |
| | 66 | (*afp->af_output)(s, 0, from, newsize); |
| | 67 | } |
| | 68 | return; |
| | 69 | |
| | 70 | case RIPCMD_TRACEON: |
| | 71 | case RIPCMD_TRACEOFF: |
| | 72 | /* verify message came from a privileged port */ |
| | 73 | if ((*afp->af_portcheck)(from) == 0) |
| | 74 | return; |
| | 75 | packet[size] = '\0'; |
| | 76 | if (msg->rip_cmd == RIPCMD_TRACEON) |
| | 77 | traceon(msg->rip_tracefile); |
| | 78 | else |
| | 79 | traceoff(); |
| | 80 | return; |
| | 81 | |
| | 82 | case RIPCMD_RESPONSE: |
| | 83 | /* verify message came from a router */ |
| | 84 | if ((*afp->af_portmatch)(from) == 0) |
| | 85 | return; |
| | 86 | (*afp->af_canon)(from); |
| | 87 | /* are we talking to ourselves? */ |
| | 88 | ifp = if_ifwithaddr(from); |
| | 89 | if (ifp) { |
| | 90 | rt = rtfind(from); |
| | 91 | if (rt == 0 || (rt->rt_state & RTS_INTERFACE) == 0) |
| | 92 | addrouteforif(ifp); |
| | 93 | else |
| | 94 | rt->rt_timer = 0; |
| | 95 | return; |
| | 96 | } |
| | 97 | /* update timer for interface on which the packet arrived */ |
| | 98 | if ((rt = rtfind(from)) && (rt->rt_state & RTS_INTERFACE)) |
| | 99 | rt->rt_timer = 0; |
| | 100 | size -= 4 * sizeof (char); |
| | 101 | n = msg->rip_nets; |
| | 102 | for (; size > 0; size -= sizeof (struct netinfo), n++) { |
| | 103 | if (size < sizeof (struct netinfo)) |
| | 104 | break; |
| | 105 | if (msg->rip_vers > 0) { |
| | 106 | n->rip_dst.sa_family = |
| | 107 | ntohs(n->rip_dst.sa_family); |
| | 108 | n->rip_metric = ntohl(n->rip_metric); |
| | 109 | } |
| | 110 | if ((unsigned) n->rip_metric >= HOPCNT_INFINITY) |
| | 111 | continue; |
| | 112 | if (n->rip_dst.sa_family >= AF_MAX) |
| | 113 | continue; |
| | 114 | afp = &afswitch[n->rip_dst.sa_family]; |
| | 115 | if (((*afp->af_checkhost)(&n->rip_dst)) == 0) |
| | 116 | continue; |
| | 117 | rt = rtlookup(&n->rip_dst); |
| | 118 | if (rt == 0) { |
| | 119 | rtadd(&n->rip_dst, from, n->rip_metric, 0); |
| | 120 | continue; |
| | 121 | } |
| | 122 | |
| | 123 | /* |
| | 124 | * Update if from gateway and different, |
| | 125 | * shorter, or getting stale and equivalent. |
| | 126 | */ |
| | 127 | if ((equal(from, &rt->rt_router) && |
| | 128 | n->rip_metric != rt->rt_metric ) || |
| | 129 | (unsigned) (n->rip_metric) < rt->rt_metric || |
| | 130 | (rt->rt_timer > (EXPIRE_TIME/2) && |
| | 131 | rt->rt_metric == n->rip_metric)) { |
| | 132 | rtchange(rt, from, n->rip_metric); |
| | 133 | rt->rt_timer = 0; |
| | 134 | } |
| | 135 | } |
| | 136 | return; |
| | 137 | } |
| | 138 | } |
projects / unix-history / blame_incremental