/* $NetBSD: input.c,v 1.14 1995/05/28 05:37:32 jtc Exp $ */ /* * Copyright (c) 1983, 1988, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef lint #if 0 static char sccsid[] = "@(#)input.c 8.1 (Berkeley) 6/5/93"; #else static char rcsid[] = "$NetBSD: input.c,v 1.14 1995/05/28 05:37:32 jtc Exp $"; #endif #endif /* not lint */ /* * Routing Table Management Daemon */ #include "defs.h" #include /* * Process a newly received packet. */ void rip_input(from, rip, size) struct sockaddr *from; register struct rip *rip; int size; { register struct rt_entry *rt; register struct netinfo *n; register struct interface *ifp; struct interface *if_ifwithdstaddr(); int count, changes = 0; register struct afswitch *afp; static struct sockaddr badfrom, badfrom2; char buf1[256], buf2[256]; ifp = 0; TRACE_INPUT(ifp, from, (char *)rip, 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, rip->rip_cmd); return; } if (rip->rip_vers == 0) { syslog(LOG_ERR, "RIP version 0 packet received from %s! (cmd %d)", (*afswitch[from->sa_family].af_format)(from, buf1, sizeof(buf1)), rip->rip_cmd); return; } switch (rip->rip_cmd) { case RIPCMD_REQUEST: n = rip->rip_nets; count = size - ((char *)n - (char *)rip); if (count < sizeof (struct netinfo)) return; for (; count > 0; n++) { if (count < sizeof (struct netinfo)) break; count -= sizeof (struct netinfo); #if BSD < 198810 if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */ n->rip_dst.sa_family = ntohs(n->rip_dst.sa_family); #else #define osa(x) ((struct osockaddr *)(&(x))) n->rip_dst.sa_family = ntohs(osa(n->rip_dst)->sa_family); n->rip_dst.sa_len = sizeof(n->rip_dst); #endif 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 && count == 0) { if (supplier || (*afp->af_portmatch)(from) == 0) supply(from, 0, 0, 0); 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; #define min(a, b) (a < b ? a : b) n->rip_metric = rt == 0 ? HOPCNT_INFINITY : min(rt->rt_metric + 1, HOPCNT_INFINITY); #if BSD < 198810 if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */ n->rip_dst.sa_family = htons(n->rip_dst.sa_family); #else osa(n->rip_dst)->sa_family = htons(n->rip_dst.sa_family); #endif n->rip_metric = htonl(n->rip_metric); } rip->rip_cmd = RIPCMD_RESPONSE; memcpy(packet, rip, size); (*afp->af_output)(s, 0, from, size); return; case RIPCMD_TRACEON: case RIPCMD_TRACEOFF: /* verify message came from a privileged port */ if ((*afp->af_portcheck)(from) == 0) return; if ((ifp = if_iflookup(from)) == 0) { syslog(LOG_ERR, "trace command from unknown router, %s", (*afswitch[from->sa_family].af_format)(from, buf1, sizeof(buf1))); return; } if ((ifp->int_flags & (IFF_BROADCAST|IFF_POINTOPOINT|IFF_REMOTE)) == 0) { syslog(LOG_ERR, "trace command from router %s, with bad flags %x", (*afswitch[from->sa_family].af_format)(from, buf1, sizeof(buf1)), ifp->int_flags); return; } if ((ifp->int_flags & IFF_PASSIVE) != 0) { syslog(LOG_ERR, "trace command from %s on a passive interface", (*afswitch[from->sa_family].af_format)(from, buf1, sizeof(buf1))); return; } ((char *)rip)[size] = '\0'; if (rip->rip_cmd == RIPCMD_TRACEON) traceon(rip->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) { if (ifp->int_flags & IFF_PASSIVE) { syslog(LOG_ERR, "bogus input (from passive interface, %s)", (*afswitch[from->sa_family].af_format)(from, buf1, sizeof(buf1))); return; } rt = rtfind(from); if (rt == 0 || ((rt->rt_state & RTS_INTERFACE) == 0) && rt->rt_metric >= ifp->int_metric) 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 | RTS_REMOTE))) rt->rt_timer = 0; else if ((ifp = if_ifwithdstaddr(from)) && (rt == 0 || rt->rt_metric >= ifp->int_metric)) addrouteforif(ifp); /* * "Authenticate" router from which message originated. * We accept routing packets from routers directly connected * via broadcast or point-to-point networks, * and from those listed in /etc/gateways. */ if ((ifp = if_iflookup(from)) == 0 || (ifp->int_flags & (IFF_BROADCAST | IFF_POINTOPOINT | IFF_REMOTE)) == 0 || ifp->int_flags & IFF_PASSIVE) { if (memcmp(from, &badfrom, sizeof(badfrom)) != 0) { syslog(LOG_ERR, "packet from unknown router, %s", (*afswitch[from->sa_family].af_format)(from, buf1, sizeof(buf1))); badfrom = *from; } return; } size -= 4 * sizeof (char); n = rip->rip_nets; for (; size > 0; size -= sizeof (struct netinfo), n++) { if (size < sizeof (struct netinfo)) break; #if BSD < 198810 if (sizeof(n->rip_dst.sa_family) > 1) /* XXX */ n->rip_dst.sa_family = ntohs(n->rip_dst.sa_family); #else n->rip_dst.sa_family = ntohs(osa(n->rip_dst)->sa_family); n->rip_dst.sa_len = sizeof(n->rip_dst); #endif n->rip_metric = ntohl(n->rip_metric); 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, buf1, sizeof(buf1)), from->sa_family); continue; } if (((*afp->af_checkhost)(&n->rip_dst)) == 0) { syslog(LOG_DEBUG, "bad host %s in route from %s (af %d)\n", (*afswitch[n->rip_dst.sa_family].af_format)( &n->rip_dst, buf1, sizeof(buf1)), (*afswitch[from->sa_family].af_format)(from, buf2, sizeof(buf2)), from->sa_family); continue; } if (n->rip_metric == 0 || (unsigned) n->rip_metric > HOPCNT_INFINITY) { if (memcmp(from, &badfrom2, sizeof(badfrom2)) != 0) { syslog(LOG_ERR, "bad metric (%d) from %s\n", n->rip_metric, (*afswitch[from->sa_family].af_format)(from, buf1, sizeof(buf1))); badfrom2 = *from; } continue; } /* * Adjust metric according to incoming interface. */ if ((unsigned) n->rip_metric < HOPCNT_INFINITY) n->rip_metric += ifp->int_metric; if ((unsigned) n->rip_metric > HOPCNT_INFINITY) n->rip_metric = HOPCNT_INFINITY; rt = rtlookup(&n->rip_dst); if (rt == 0 || (rt->rt_state & (RTS_INTERNAL|RTS_INTERFACE)) == (RTS_INTERNAL|RTS_INTERFACE)) { /* * If we're hearing a logical network route * back from a peer to which we sent it, * ignore it. */ if (rt && rt->rt_state & RTS_SUBNET && (*afp->af_sendroute)(rt, from)) continue; if ((unsigned)n->rip_metric < HOPCNT_INFINITY) { /* * Look for an equivalent route that * includes this one before adding * this route. */ rt = rtfind(&n->rip_dst); if (rt && equal(from, &rt->rt_router)) continue; rtadd(&n->rip_dst, from, n->rip_metric, 0); changes++; } continue; } /* * Update if from gateway and different, * shorter, or equivalent but old route * is getting stale. */ if (equal(from, &rt->rt_router)) { if (n->rip_metric != rt->rt_metric) { rtchange(rt, from, n->rip_metric); changes++; rt->rt_timer = 0; if (rt->rt_metric >= HOPCNT_INFINITY) rt->rt_timer = GARBAGE_TIME - EXPIRE_TIME; } else if (rt->rt_metric < HOPCNT_INFINITY) rt->rt_timer = 0; } else if ((unsigned) n->rip_metric < rt->rt_metric || (rt->rt_metric == n->rip_metric && rt->rt_timer > (EXPIRE_TIME/2) && (unsigned) n->rip_metric < HOPCNT_INFINITY)) { rtchange(rt, from, n->rip_metric); changes++; rt->rt_timer = 0; } } break; } /* * If changes have occurred, and if we have not sent a broadcast * recently, send a dynamic update. This update is sent only * on interfaces other than the one on which we received notice * of the change. If we are within MIN_WAITTIME of a full update, * don't bother sending; if we just sent a dynamic update * and set a timer (nextbcast), delay until that time. * If we just sent a full update, delay the dynamic update. * Set a timer for a randomized value to suppress additional * dynamic updates until it expires; if we delayed sending * the current changes, set needupdate. */ if (changes && supplier && now.tv_sec - lastfullupdate.tv_sec < SUPPLY_INTERVAL-MAX_WAITTIME) { u_long delay; extern long random(); if (now.tv_sec - lastbcast.tv_sec >= MIN_WAITTIME && timercmp(&nextbcast, &now, <)) { if (traceactions) fprintf(ftrace, "send dynamic update\n"); toall(supply, RTS_CHANGED, ifp); lastbcast = now; needupdate = 0; nextbcast.tv_sec = 0; } else { needupdate++; if (traceactions) fprintf(ftrace, "delay dynamic update\n"); } #define RANDOMDELAY() (MIN_WAITTIME * 1000000 + \ (u_long)random() % ((MAX_WAITTIME - MIN_WAITTIME) * 1000000)) if (nextbcast.tv_sec == 0) { delay = RANDOMDELAY(); if (traceactions) fprintf(ftrace, "inhibit dynamic update for %d usec\n", delay); nextbcast.tv_sec = delay / 1000000; nextbcast.tv_usec = delay % 1000000; timeradd(&nextbcast, &now, &nextbcast); /* * If the next possibly dynamic update * is within MIN_WAITTIME of the next full update, * force the delay past the full update, * or we might send a dynamic update just before * the full update. */ if (nextbcast.tv_sec > lastfullupdate.tv_sec + SUPPLY_INTERVAL - MIN_WAITTIME) nextbcast.tv_sec = lastfullupdate.tv_sec + SUPPLY_INTERVAL + 1; } } }