don't call (null)->hash; if not supplying table dump to query for all,

[unix-history] / usr / src / sbin / routed / input.c

/*
* Copyright (c) 1983 Regents of the University of California.
* All rights reserved.  The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*/

#ifndef lint
static char sccsid[] = "@(#)input.c     5.3 (Berkeley) %G%";
#endif not lint

/*
* Routing Table Management Daemon
*/
#include "defs.h"
#include <sys/syslog.h>

/*
* Process a newly received packet.
*/
rip_input(from, size)
       struct sockaddr *from;
       int size;
{
       register struct rt_entry *rt;
       register struct netinfo *n;
       register struct interface *ifp;
       struct interface *if_ifwithdstaddr();
       int newsize;
       register struct afswitch *afp;

       ifp = 0;
       TRACE_INPUT(ifp, from, size);
       if (from->sa_family >= af_max ||
           (afp = &afswitch[from->sa_family])->af_hash == (int (*)())0) {
               syslog(LOG_INFO,
        "\"from\" address in unsupported address family (%d), cmd %d\n",
                   from->sa_family, msg->rip_cmd);
               return;
       }
       switch (msg->rip_cmd) {

       case RIPCMD_REQUEST:
               newsize = 0;
               size -= 4 * sizeof (char);
               n = msg->rip_nets;
               while (size > 0) {
                       if (size < sizeof (struct netinfo))
                               break;
                       size -= sizeof (struct netinfo);

                       if (msg->rip_vers > 0) {
                               n->rip_dst.sa_family =
                                       ntohs(n->rip_dst.sa_family);
                               n->rip_metric = ntohl(n->rip_metric);
                       }
                       /* 
                        * A single entry with sa_family == AF_UNSPEC and
                        * metric ``infinity'' means ``all routes''.
                        * We respond to routers only if we are acting
                        * as a supplier, or to anyone other than a router
                        * (eg, query).
                        */
                       if (n->rip_dst.sa_family == AF_UNSPEC &&
                           n->rip_metric == HOPCNT_INFINITY && size == 0) {
                               if (supplier || (*afp->af_portmatch)(from) == 0)
                                       supply(from, 0, ifp);
                               return;
                       }
                       if (n->rip_dst.sa_family < af_max &&
                           afswitch[n->rip_dst.sa_family].af_hash)
                               rt = rtlookup(&n->rip_dst);
                       else
                               rt = 0;
                       n->rip_metric = rt == 0 ? HOPCNT_INFINITY :
                               min(rt->rt_metric+1, HOPCNT_INFINITY);
                       if (msg->rip_vers > 0) {
                               n->rip_dst.sa_family =
                                       htons(n->rip_dst.sa_family);
                               n->rip_metric = htonl(n->rip_metric);
                       }
                       n++, newsize += sizeof (struct netinfo);
               }
               if (newsize > 0) {
                       msg->rip_cmd = RIPCMD_RESPONSE;
                       newsize += sizeof (int);
                       (*afp->af_output)(s, 0, from, newsize);
               }
               return;

       case RIPCMD_TRACEON:
       case RIPCMD_TRACEOFF:
               /* verify message came from a privileged port */
               if ((*afp->af_portcheck)(from) == 0)
                       return;
               packet[size] = '\0';
               if (msg->rip_cmd == RIPCMD_TRACEON)
                       traceon(msg->rip_tracefile);
               else
                       traceoff();
               return;

       case RIPCMD_RESPONSE:
               /* verify message came from a router */
               if ((*afp->af_portmatch)(from) == 0)
                       return;
               (*afp->af_canon)(from);
               /* are we talking to ourselves? */
               ifp = if_ifwithaddr(from);
               if (ifp) {
                       rt = rtfind(from);
                       if (rt == 0 || (rt->rt_state & RTS_INTERFACE) == 0)
                               addrouteforif(ifp);
                       else
                               rt->rt_timer = 0;
                       return;
               }
               /*
                * Update timer for interface on which the packet arrived.
                * If from other end of a point-to-point link that isn't
                * in the routing tables, (re-)add the route.
                */
               if ((rt = rtfind(from)) && (rt->rt_state & RTS_INTERFACE))
                       rt->rt_timer = 0;
               else if (ifp = if_ifwithdstaddr(from))
                       addrouteforif(ifp);
               size -= 4 * sizeof (char);
               n = msg->rip_nets;
               for (; size > 0; size -= sizeof (struct netinfo), n++) {
                       if (size < sizeof (struct netinfo))
                               break;
                       if (msg->rip_vers > 0) {
                               n->rip_dst.sa_family =
                                       ntohs(n->rip_dst.sa_family);
                               n->rip_metric = ntohl(n->rip_metric);
                       }
                       if ((unsigned) n->rip_metric > HOPCNT_INFINITY)
                               continue;
                       if (n->rip_dst.sa_family >= af_max ||
                           (afp = &afswitch[n->rip_dst.sa_family])->af_hash ==
                           (int (*)())0) {
                               syslog(LOG_INFO,
               "route in unsupported address family (%d), from %s (af %d)\n",
                                  n->rip_dst.sa_family,
                                  (*afswitch[from->sa_family].af_format)(from),
                                  from->sa_family);
                               continue;
                       }
                       if (((*afp->af_checkhost)(&n->rip_dst)) == 0) {
                               syslog(LOG_DEBUG,
                                   "bad host in route from %s (af %d)\n",
                                  (*afswitch[from->sa_family].af_format)(from),
                                  from->sa_family);
                               continue;
                       }
                       rt = rtlookup(&n->rip_dst);
                       if (rt == 0) {
                               if (n->rip_metric < HOPCNT_INFINITY)
                                   rtadd(&n->rip_dst, from, n->rip_metric, 0);
                               continue;
                       }

                       /*
                        * Update if from gateway and different,
                        * shorter, or getting stale and equivalent.
                        */
                       if (equal(from, &rt->rt_router)) {
                               if (n->rip_metric == HOPCNT_INFINITY) {
                                       rtdelete(rt);
                                       continue;
                               }
                               if (n->rip_metric != rt->rt_metric)
                                       rtchange(rt, from, n->rip_metric);
                               rt->rt_timer = 0;
                       } else if ((unsigned) (n->rip_metric) < rt->rt_metric ||
                           (rt->rt_timer > (EXPIRE_TIME/2) &&
                           rt->rt_metric == n->rip_metric)) {
                               rtchange(rt, from, n->rip_metric);
                               rt->rt_timer = 0;
                       }
               }
               return;
       }
}