routed.tproj/input.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * "Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
   7  * Reserved.  This file contains Original Code and/or Modifications of
   8  * Original Code as defined in and that are subject to the Apple Public
   9  * Source License Version 1.0 (the 'License').  You may not use this file
  10  * except in compliance with the License.  Please obtain a copy of the
  11  * License at http://www.apple.com/publicsource and read it before using
  12  * this file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  19  * License for the specific language governing rights and limitations
  20  * under the License."
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24 /*
  25  * Copyright (c) 1983, 1988, 1993
  26  *      The Regents of the University of California.  All rights reserved.
  27  *
  28  * Redistribution and use in source and binary forms, with or without
  29  * modification, are permitted provided that the following conditions
  30  * are met:
  31  * 1. Redistributions of source code must retain the above copyright
  32  *    notice, this list of conditions and the following disclaimer.
  33  * 2. Redistributions in binary form must reproduce the above copyright
  34  *    notice, this list of conditions and the following disclaimer in the
  35  *    documentation and/or other materials provided with the distribution.
  36  * 3. All advertising materials mentioning features or use of this software
  37  *    must display the following acknowledgment:
  38  *      This product includes software developed by the University of
  39  *      California, Berkeley and its contributors.
  40  * 4. Neither the name of the University nor the names of its contributors
  41  *    may be used to endorse or promote products derived from this software
  42  *    without specific prior written permission.
  43  *
  44  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  45  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  46  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  47  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  48  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  49  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  50  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  51  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  52  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  53  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  54  * SUCH DAMAGE.
  55  *
  56  *      @(#)defs.h      8.1 (Berkeley) 6/5/93
  57  */
  58
  59
  60 /*
  61  * Routing Table Management Daemon
  62  */
  63 #include "defs.h"
  64 #include <sys/syslog.h>
  65
  66 /*
  67  * Process a newly received packet.
  68  */
  69 rip_input(from, rip, size)
  70         struct sockaddr *from;
  71         register struct rip *rip;
  72         int size;
  73 {
  74         register struct rt_entry *rt;
  75         register struct netinfo *n;
  76         register struct interface *ifp;
  77         struct interface *if_ifwithdstaddr();
  78         int count, changes = 0;
  79         register struct afswitch *afp;
  80         static struct sockaddr badfrom, badfrom2;
  81
  82         ifp = 0;
  83         TRACE_INPUT(ifp, from, (char *)rip, size);
  84         if (from->sa_family >= af_max ||
  85             (afp = &afswitch[from->sa_family])->af_hash == (int (*)())0) {
  86                 syslog(LOG_INFO,
  87          "\"from\" address in unsupported address family (%d), cmd %d\n",
  88                     from->sa_family, rip->rip_cmd);
  89                 return;
  90         }
  91         if (rip->rip_vers == 0) {
  92                 syslog(LOG_ERR,
  93                     "RIP version 0 packet received from %s! (cmd %d)",
  94                     (*afswitch[from->sa_family].af_format)(from), rip->rip_cmd);
  95                 return;
  96         }
  97         switch (rip->rip_cmd) {
  98
  99         case RIPCMD_REQUEST:
 100                 n = rip->rip_nets;
 101                 count = size - ((char *)n - (char *)rip);
 102                 if (count < sizeof (struct netinfo))
 103                         return;
 104                 for (; count > 0; n++) {
 105                         if (count < sizeof (struct netinfo))
 106                                 break;
 107                         count -= sizeof (struct netinfo);
 108
 109 #if BSD < 198810
 110                         if (sizeof(n->rip_dst.sa_family) > 1)   /* XXX */
 111                             n->rip_dst.sa_family = ntohs(n->rip_dst.sa_family);
 112 #else
 113 #define osa(x) ((struct osockaddr *)(&(x)))
 114                             n->rip_dst.sa_family =
 115                                         ntohs(osa(n->rip_dst)->sa_family);
 116                             n->rip_dst.sa_len = sizeof(n->rip_dst);
 117 #endif
 118                         n->rip_metric = ntohl(n->rip_metric);
 119                         /*
 120                          * A single entry with sa_family == AF_UNSPEC and
 121                          * metric ``infinity'' means ``all routes''.
 122                          * We respond to routers only if we are acting
 123                          * as a supplier, or to anyone other than a router
 124                          * (eg, query).
 125                          */
 126                         if (n->rip_dst.sa_family == AF_UNSPEC &&
 127                             n->rip_metric == HOPCNT_INFINITY && count == 0) {
 128                                 if (supplier || (*afp->af_portmatch)(from) == 0)
 129                                         supply(from, 0, 0, 0);
 130                                 return;
 131                         }
 132                         if (n->rip_dst.sa_family < af_max &&
 133                             afswitch[n->rip_dst.sa_family].af_hash)
 134                                 rt = rtlookup(&n->rip_dst);
 135                         else
 136                                 rt = 0;
 137 #define min(a, b) (a < b ? a : b)
 138                         n->rip_metric = rt == 0 ? HOPCNT_INFINITY :
 139                                 min(rt->rt_metric + 1, HOPCNT_INFINITY);
 140 #if BSD < 198810
 141                         if (sizeof(n->rip_dst.sa_family) > 1)   /* XXX */
 142                             n->rip_dst.sa_family = htons(n->rip_dst.sa_family);
 143 #else
 144                             osa(n->rip_dst)->sa_family =
 145                                                 htons(n->rip_dst.sa_family);
 146 #endif
 147                         n->rip_metric = htonl(n->rip_metric);
 148                 }
 149                 rip->rip_cmd = RIPCMD_RESPONSE;
 150                 memmove(packet, rip, size);
 151                 (*afp->af_output)(s, 0, from, size);
 152                 return;
 153
 154         case RIPCMD_TRACEON:
 155         case RIPCMD_TRACEOFF:
 156                 /* verify message came from a privileged port */
 157                 if ((*afp->af_portcheck)(from) == 0)
 158                         return;
 159                 if ((ifp = if_iflookup(from)) == 0 || (ifp->int_flags &
 160                     (IFF_BROADCAST | IFF_POINTOPOINT | IFF_REMOTE)) == 0 ||
 161                     ifp->int_flags & IFF_PASSIVE) {
 162                         syslog(LOG_ERR, "trace command from unknown router, %s",
 163                             (*afswitch[from->sa_family].af_format)(from));
 164                         return;
 165                 }
 166                 ((char *)rip)[size] = '\0';
 167                 if (rip->rip_cmd == RIPCMD_TRACEON)
 168                         traceon(rip->rip_tracefile);
 169                 else
 170                         traceoff();
 171                 return;
 172
 173         case RIPCMD_RESPONSE:
 174                 /* verify message came from a router */
 175                 if ((*afp->af_portmatch)(from) == 0)
 176                         return;
 177                 (*afp->af_canon)(from);
 178                 /* are we talking to ourselves? */
 179                 ifp = if_ifwithaddr(from);
 180                 if (ifp) {
 181                         if (ifp->int_flags & IFF_PASSIVE) {
 182                                 syslog(LOG_ERR,
 183                                   "bogus input (from passive interface, %s)",
 184                                   (*afswitch[from->sa_family].af_format)(from));
 185                                 return;
 186                         }
 187                         rt = rtfind(from);
 188                         if (rt == 0 || ((rt->rt_state & RTS_INTERFACE) == 0) &&
 189                             rt->rt_metric >= ifp->int_metric)
 190                                 addrouteforif(ifp);
 191                         else
 192                                 rt->rt_timer = 0;
 193                         return;
 194                 }
 195                 /*
 196                  * Update timer for interface on which the packet arrived.
 197                  * If from other end of a point-to-point link that isn't
 198                  * in the routing tables, (re-)add the route.
 199                  */
 200                 if ((rt = rtfind(from)) &&
 201                     (rt->rt_state & (RTS_INTERFACE | RTS_REMOTE)))
 202                         rt->rt_timer = 0;
 203                 else if ((ifp = if_ifwithdstaddr(from)) &&
 204                     (rt == 0 || rt->rt_metric >= ifp->int_metric))
 205                         addrouteforif(ifp);
 206                 /*
 207                  * "Authenticate" router from which message originated.
 208                  * We accept routing packets from routers directly connected
 209                  * via broadcast or point-to-point networks,
 210                  * and from those listed in /etc/gateways.
 211                  */
 212                 if ((ifp = if_iflookup(from)) == 0 || (ifp->int_flags &
 213                     (IFF_BROADCAST | IFF_POINTOPOINT | IFF_REMOTE)) == 0 ||
 214                     ifp->int_flags & IFF_PASSIVE) {
 215                         if (memcmp(from, &badfrom, sizeof(badfrom)) != 0) {
 216                                 syslog(LOG_ERR,
 217                                   "packet from unknown router, %s",
 218                                   (*afswitch[from->sa_family].af_format)(from));
 219                                 badfrom = *from;
 220                         }
 221                         return;
 222                 }
 223                 size -= 4 * sizeof (char);
 224                 n = rip->rip_nets;
 225                 for (; size > 0; size -= sizeof (struct netinfo), n++) {
 226                         if (size < sizeof (struct netinfo))
 227                                 break;
 228 #if BSD < 198810
 229                         if (sizeof(n->rip_dst.sa_family) > 1)   /* XXX */
 230                                 n->rip_dst.sa_family =
 231                                         ntohs(n->rip_dst.sa_family);
 232 #else
 233                             n->rip_dst.sa_family =
 234                                         ntohs(osa(n->rip_dst)->sa_family);
 235                             n->rip_dst.sa_len = sizeof(n->rip_dst);
 236 #endif
 237                         n->rip_metric = ntohl(n->rip_metric);
 238                         if (n->rip_dst.sa_family >= af_max ||
 239                             (afp = &afswitch[n->rip_dst.sa_family])->af_hash ==
 240                             (int (*)())0) {
 241                                 syslog(LOG_INFO,
 242                 "route in unsupported address family (%d), from %s (af %d)\n",
 243                                    n->rip_dst.sa_family,
 244                                    (*afswitch[from->sa_family].af_format)(from),
 245                                    from->sa_family);
 246                                 continue;
 247                         }
 248                         if (((*afp->af_checkhost)(&n->rip_dst)) == 0) {
 249                                 syslog(LOG_DEBUG,
 250                                     "bad host in route from %s (af %d)\n",
 251                                    (*afswitch[from->sa_family].af_format)(from),
 252                                    from->sa_family);
 253                                 continue;
 254                         }
 255                         if (n->rip_metric == 0 ||
 256                             (unsigned) n->rip_metric > HOPCNT_INFINITY) {
 257                                 if (memcmp(from, &badfrom2,
 258                                     sizeof(badfrom2)) != 0) {
 259                                         syslog(LOG_ERR,
 260                                             "bad metric (%d) from %s\n",
 261                                             n->rip_metric,
 262                                   (*afswitch[from->sa_family].af_format)(from));
 263                                         badfrom2 = *from;
 264                                 }
 265                                 continue;
 266                         }
 267                         /*
 268                          * Adjust metric according to incoming interface.
 269                          */
 270                         if ((unsigned) n->rip_metric < HOPCNT_INFINITY)
 271                                 n->rip_metric += ifp->int_metric;
 272                         if ((unsigned) n->rip_metric > HOPCNT_INFINITY)
 273                                 n->rip_metric = HOPCNT_INFINITY;
 274                         rt = rtlookup(&n->rip_dst);
 275                         if (rt == 0 ||
 276                             (rt->rt_state & (RTS_INTERNAL|RTS_INTERFACE)) ==
 277                             (RTS_INTERNAL|RTS_INTERFACE)) {
 278                                 /*
 279                                  * If we're hearing a logical network route
 280                                  * back from a peer to which we sent it,
 281                                  * ignore it.
 282                                  */
 283                                 if (rt && rt->rt_state & RTS_SUBNET &&
 284                                     (*afp->af_sendroute)(rt, from))
 285                                         continue;
 286                                 if ((unsigned)n->rip_metric < HOPCNT_INFINITY) {
 287                                     /*
 288                                      * Look for an equivalent route that
 289                                      * includes this one before adding
 290                                      * this route.
 291                                      */
 292                                     rt = rtfind(&n->rip_dst);
 293                                     if (rt && equal(from, &rt->rt_router))
 294                                             continue;
 295                                     rtadd(&n->rip_dst, from, n->rip_metric, 0);
 296                                     changes++;
 297                                 }
 298                                 continue;
 299                         }
 300
 301                         /*
 302                          * Update if from gateway and different,
 303                          * shorter, or equivalent but old route
 304                          * is getting stale.
 305                          */
 306                         if (equal(from, &rt->rt_router)) {
 307                                 if (n->rip_metric != rt->rt_metric) {
 308                                         rtchange(rt, from, n->rip_metric);
 309                                         changes++;
 310                                         rt->rt_timer = 0;
 311                                         if (rt->rt_metric >= HOPCNT_INFINITY)
 312                                                 rt->rt_timer =
 313                                                     GARBAGE_TIME - EXPIRE_TIME;
 314                                 } else if (rt->rt_metric < HOPCNT_INFINITY)
 315                                         rt->rt_timer = 0;
 316                         } else if ((unsigned) n->rip_metric < rt->rt_metric ||
 317                             (rt->rt_metric == n->rip_metric &&
 318                             rt->rt_timer > (EXPIRE_TIME/2) &&
 319                             (unsigned) n->rip_metric < HOPCNT_INFINITY)) {
 320                                 rtchange(rt, from, n->rip_metric);
 321                                 changes++;
 322                                 rt->rt_timer = 0;
 323                         }
 324                 }
 325                 break;
 326         }
 327
 328         /*
 329          * If changes have occurred, and if we have not sent a broadcast
 330          * recently, send a dynamic update.  This update is sent only
 331          * on interfaces other than the one on which we received notice
 332          * of the change.  If we are within MIN_WAITTIME of a full update,
 333          * don't bother sending; if we just sent a dynamic update
 334          * and set a timer (nextbcast), delay until that time.
 335          * If we just sent a full update, delay the dynamic update.
 336          * Set a timer for a randomized value to suppress additional
 337          * dynamic updates until it expires; if we delayed sending
 338          * the current changes, set needupdate.
 339          */
 340         if (changes && supplier &&
 341            now.tv_sec - lastfullupdate.tv_sec < SUPPLY_INTERVAL-MAX_WAITTIME) {
 342                 u_long delay;
 343                 extern long random();
 344
 345                 if (now.tv_sec - lastbcast.tv_sec >= MIN_WAITTIME &&
 346                     timercmp(&nextbcast, &now, <)) {
 347                         if (traceactions)
 348                                 fprintf(ftrace, "send dynamic update\n");
 349                         toall(supply, RTS_CHANGED, ifp);
 350                         lastbcast = now;
 351                         needupdate = 0;
 352                         nextbcast.tv_sec = 0;
 353                 } else {
 354                         needupdate++;
 355                         if (traceactions)
 356                                 fprintf(ftrace, "delay dynamic update\n");
 357                 }
 358 #define RANDOMDELAY()   (MIN_WAITTIME * 1000000 + \
 359                 (u_long)random() % ((MAX_WAITTIME - MIN_WAITTIME) * 1000000))
 360
 361                 if (nextbcast.tv_sec == 0) {
 362                         delay = RANDOMDELAY();
 363                         if (traceactions)
 364                                 fprintf(ftrace,
 365                                     "inhibit dynamic update for %d usec\n",
 366                                     delay);
 367                         nextbcast.tv_sec = delay / 1000000;
 368                         nextbcast.tv_usec = delay % 1000000;
 369                         timevaladd(&nextbcast, &now);
 370                         /*
 371                          * If the next possibly dynamic update
 372                          * is within MIN_WAITTIME of the next full update,
 373                          * force the delay past the full update,
 374                          * or we might send a dynamic update just before
 375                          * the full update.
 376                          */
 377                         if (nextbcast.tv_sec > lastfullupdate.tv_sec +
 378                             SUPPLY_INTERVAL - MIN_WAITTIME)
 379                                 nextbcast.tv_sec = lastfullupdate.tv_sec +
 380                                     SUPPLY_INTERVAL + 1;
 381                 }
 382         }
 383 }