routed.tproj/input.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * Copyright (c) 1983, 1988, 1993
  27  *      The Regents of the University of California.  All rights reserved.
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions
  31  * are met:
  32  * 1. Redistributions of source code must retain the above copyright
  33  *    notice, this list of conditions and the following disclaimer.
  34  * 2. Redistributions in binary form must reproduce the above copyright
  35  *    notice, this list of conditions and the following disclaimer in the
  36  *    documentation and/or other materials provided with the distribution.
  37  * 3. All advertising materials mentioning features or use of this software
  38  *    must display the following acknowledgment:
  39  *      This product includes software developed by the University of
  40  *      California, Berkeley and its contributors.
  41  * 4. Neither the name of the University nor the names of its contributors
  42  *    may be used to endorse or promote products derived from this software
  43  *    without specific prior written permission.
  44  *
  45  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  48  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  55  * SUCH DAMAGE.
  56  *
  57  *      @(#)defs.h      8.1 (Berkeley) 6/5/93
  58  */
  59
  60
  61 /*
  62  * Routing Table Management Daemon
  63  */
  64 #include "defs.h"
  65 #include <sys/syslog.h>
  66
  67 /*
  68  * Process a newly received packet.
  69  */
  70 rip_input(from, rip, size)
  71         struct sockaddr *from;
  72         register struct rip *rip;
  73         int size;
  74 {
  75         register struct rt_entry *rt;
  76         register struct netinfo *n;
  77         register struct interface *ifp;
  78         struct interface *if_ifwithdstaddr();
  79         int count, changes = 0;
  80         register struct afswitch *afp;
  81         static struct sockaddr badfrom, badfrom2;
  82
  83         ifp = 0;
  84         TRACE_INPUT(ifp, from, (char *)rip, size);
  85         if (from->sa_family >= af_max ||
  86             (afp = &afswitch[from->sa_family])->af_hash == (int (*)())0) {
  87                 syslog(LOG_INFO,
  88          "\"from\" address in unsupported address family (%d), cmd %d\n",
  89                     from->sa_family, rip->rip_cmd);
  90                 return;
  91         }
  92         if (rip->rip_vers == 0) {
  93                 syslog(LOG_ERR,
  94                     "RIP version 0 packet received from %s! (cmd %d)",
  95                     (*afswitch[from->sa_family].af_format)(from), rip->rip_cmd);
  96                 return;
  97         }
  98         switch (rip->rip_cmd) {
  99
 100         case RIPCMD_REQUEST:
 101                 n = rip->rip_nets;
 102                 count = size - ((char *)n - (char *)rip);
 103                 if (count < sizeof (struct netinfo))
 104                         return;
 105                 for (; count > 0; n++) {
 106                         if (count < sizeof (struct netinfo))
 107                                 break;
 108                         count -= sizeof (struct netinfo);
 109
 110 #if BSD < 198810
 111                         if (sizeof(n->rip_dst.sa_family) > 1)   /* XXX */
 112                             n->rip_dst.sa_family = ntohs(n->rip_dst.sa_family);
 113 #else
 114 #define osa(x) ((struct osockaddr *)(&(x)))
 115                             n->rip_dst.sa_family =
 116                                         ntohs(osa(n->rip_dst)->sa_family);
 117                             n->rip_dst.sa_len = sizeof(n->rip_dst);
 118 #endif
 119                         n->rip_metric = ntohl(n->rip_metric);
 120                         /*
 121                          * A single entry with sa_family == AF_UNSPEC and
 122                          * metric ``infinity'' means ``all routes''.
 123                          * We respond to routers only if we are acting
 124                          * as a supplier, or to anyone other than a router
 125                          * (eg, query).
 126                          */
 127                         if (n->rip_dst.sa_family == AF_UNSPEC &&
 128                             n->rip_metric == HOPCNT_INFINITY && count == 0) {
 129                                 if (supplier || (*afp->af_portmatch)(from) == 0)
 130                                         supply(from, 0, 0, 0);
 131                                 return;
 132                         }
 133                         if (n->rip_dst.sa_family < af_max &&
 134                             afswitch[n->rip_dst.sa_family].af_hash)
 135                                 rt = rtlookup(&n->rip_dst);
 136                         else
 137                                 rt = 0;
 138 #define min(a, b) (a < b ? a : b)
 139                         n->rip_metric = rt == 0 ? HOPCNT_INFINITY :
 140                                 min(rt->rt_metric + 1, HOPCNT_INFINITY);
 141 #if BSD < 198810
 142                         if (sizeof(n->rip_dst.sa_family) > 1)   /* XXX */
 143                             n->rip_dst.sa_family = htons(n->rip_dst.sa_family);
 144 #else
 145                             osa(n->rip_dst)->sa_family =
 146                                                 htons(n->rip_dst.sa_family);
 147 #endif
 148                         n->rip_metric = htonl(n->rip_metric);
 149                 }
 150                 rip->rip_cmd = RIPCMD_RESPONSE;
 151                 memmove(packet, rip, size);
 152                 (*afp->af_output)(s, 0, from, size);
 153                 return;
 154
 155         case RIPCMD_TRACEON:
 156         case RIPCMD_TRACEOFF:
 157                 /* verify message came from a privileged port */
 158                 if ((*afp->af_portcheck)(from) == 0)
 159                         return;
 160                 if ((ifp = if_iflookup(from)) == 0 || (ifp->int_flags &
 161                     (IFF_BROADCAST | IFF_POINTOPOINT | IFF_REMOTE)) == 0 ||
 162                     ifp->int_flags & IFF_PASSIVE) {
 163                         syslog(LOG_ERR, "trace command from unknown router, %s",
 164                             (*afswitch[from->sa_family].af_format)(from));
 165                         return;
 166                 }
 167                 ((char *)rip)[size] = '\0';
 168                 if (rip->rip_cmd == RIPCMD_TRACEON)
 169                         traceon(rip->rip_tracefile);
 170                 else
 171                         traceoff();
 172                 return;
 173
 174         case RIPCMD_RESPONSE:
 175                 /* verify message came from a router */
 176                 if ((*afp->af_portmatch)(from) == 0)
 177                         return;
 178                 (*afp->af_canon)(from);
 179                 /* are we talking to ourselves? */
 180                 ifp = if_ifwithaddr(from);
 181                 if (ifp) {
 182                         if (ifp->int_flags & IFF_PASSIVE) {
 183                                 syslog(LOG_ERR,
 184                                   "bogus input (from passive interface, %s)",
 185                                   (*afswitch[from->sa_family].af_format)(from));
 186                                 return;
 187                         }
 188                         rt = rtfind(from);
 189                         if (rt == 0 || ((rt->rt_state & RTS_INTERFACE) == 0) &&
 190                             rt->rt_metric >= ifp->int_metric)
 191                                 addrouteforif(ifp);
 192                         else
 193                                 rt->rt_timer = 0;
 194                         return;
 195                 }
 196                 /*
 197                  * Update timer for interface on which the packet arrived.
 198                  * If from other end of a point-to-point link that isn't
 199                  * in the routing tables, (re-)add the route.
 200                  */
 201                 if ((rt = rtfind(from)) &&
 202                     (rt->rt_state & (RTS_INTERFACE | RTS_REMOTE)))
 203                         rt->rt_timer = 0;
 204                 else if ((ifp = if_ifwithdstaddr(from)) &&
 205                     (rt == 0 || rt->rt_metric >= ifp->int_metric))
 206                         addrouteforif(ifp);
 207                 /*
 208                  * "Authenticate" router from which message originated.
 209                  * We accept routing packets from routers directly connected
 210                  * via broadcast or point-to-point networks,
 211                  * and from those listed in /etc/gateways.
 212                  */
 213                 if ((ifp = if_iflookup(from)) == 0 || (ifp->int_flags &
 214                     (IFF_BROADCAST | IFF_POINTOPOINT | IFF_REMOTE)) == 0 ||
 215                     ifp->int_flags & IFF_PASSIVE) {
 216                         if (memcmp(from, &badfrom, sizeof(badfrom)) != 0) {
 217                                 syslog(LOG_ERR,
 218                                   "packet from unknown router, %s",
 219                                   (*afswitch[from->sa_family].af_format)(from));
 220                                 badfrom = *from;
 221                         }
 222                         return;
 223                 }
 224                 size -= 4 * sizeof (char);
 225                 n = rip->rip_nets;
 226                 for (; size > 0; size -= sizeof (struct netinfo), n++) {
 227                         if (size < sizeof (struct netinfo))
 228                                 break;
 229 #if BSD < 198810
 230                         if (sizeof(n->rip_dst.sa_family) > 1)   /* XXX */
 231                                 n->rip_dst.sa_family =
 232                                         ntohs(n->rip_dst.sa_family);
 233 #else
 234                             n->rip_dst.sa_family =
 235                                         ntohs(osa(n->rip_dst)->sa_family);
 236                             n->rip_dst.sa_len = sizeof(n->rip_dst);
 237 #endif
 238                         n->rip_metric = ntohl(n->rip_metric);
 239                         if (n->rip_dst.sa_family >= af_max ||
 240                             (afp = &afswitch[n->rip_dst.sa_family])->af_hash ==
 241                             (int (*)())0) {
 242                                 syslog(LOG_INFO,
 243                 "route in unsupported address family (%d), from %s (af %d)\n",
 244                                    n->rip_dst.sa_family,
 245                                    (*afswitch[from->sa_family].af_format)(from),
 246                                    from->sa_family);
 247                                 continue;
 248                         }
 249                         if (((*afp->af_checkhost)(&n->rip_dst)) == 0) {
 250                                 syslog(LOG_DEBUG,
 251                                     "bad host in route from %s (af %d)\n",
 252                                    (*afswitch[from->sa_family].af_format)(from),
 253                                    from->sa_family);
 254                                 continue;
 255                         }
 256                         if (n->rip_metric == 0 ||
 257                             (unsigned) n->rip_metric > HOPCNT_INFINITY) {
 258                                 if (memcmp(from, &badfrom2,
 259                                     sizeof(badfrom2)) != 0) {
 260                                         syslog(LOG_ERR,
 261                                             "bad metric (%d) from %s\n",
 262                                             n->rip_metric,
 263                                   (*afswitch[from->sa_family].af_format)(from));
 264                                         badfrom2 = *from;
 265                                 }
 266                                 continue;
 267                         }
 268                         /*
 269                          * Adjust metric according to incoming interface.
 270                          */
 271                         if ((unsigned) n->rip_metric < HOPCNT_INFINITY)
 272                                 n->rip_metric += ifp->int_metric;
 273                         if ((unsigned) n->rip_metric > HOPCNT_INFINITY)
 274                                 n->rip_metric = HOPCNT_INFINITY;
 275                         rt = rtlookup(&n->rip_dst);
 276                         if (rt == 0 ||
 277                             (rt->rt_state & (RTS_INTERNAL|RTS_INTERFACE)) ==
 278                             (RTS_INTERNAL|RTS_INTERFACE)) {
 279                                 /*
 280                                  * If we're hearing a logical network route
 281                                  * back from a peer to which we sent it,
 282                                  * ignore it.
 283                                  */
 284                                 if (rt && rt->rt_state & RTS_SUBNET &&
 285                                     (*afp->af_sendroute)(rt, from))
 286                                         continue;
 287                                 if ((unsigned)n->rip_metric < HOPCNT_INFINITY) {
 288                                     /*
 289                                      * Look for an equivalent route that
 290                                      * includes this one before adding
 291                                      * this route.
 292                                      */
 293                                     rt = rtfind(&n->rip_dst);
 294                                     if (rt && equal(from, &rt->rt_router))
 295                                             continue;
 296                                     rtadd(&n->rip_dst, from, n->rip_metric, 0);
 297                                     changes++;
 298                                 }
 299                                 continue;
 300                         }
 301
 302                         /*
 303                          * Update if from gateway and different,
 304                          * shorter, or equivalent but old route
 305                          * is getting stale.
 306                          */
 307                         if (equal(from, &rt->rt_router)) {
 308                                 if (n->rip_metric != rt->rt_metric) {
 309                                         rtchange(rt, from, n->rip_metric);
 310                                         changes++;
 311                                         rt->rt_timer = 0;
 312                                         if (rt->rt_metric >= HOPCNT_INFINITY)
 313                                                 rt->rt_timer =
 314                                                     GARBAGE_TIME - EXPIRE_TIME;
 315                                 } else if (rt->rt_metric < HOPCNT_INFINITY)
 316                                         rt->rt_timer = 0;
 317                         } else if ((unsigned) n->rip_metric < rt->rt_metric ||
 318                             (rt->rt_metric == n->rip_metric &&
 319                             rt->rt_timer > (EXPIRE_TIME/2) &&
 320                             (unsigned) n->rip_metric < HOPCNT_INFINITY)) {
 321                                 rtchange(rt, from, n->rip_metric);
 322                                 changes++;
 323                                 rt->rt_timer = 0;
 324                         }
 325                 }
 326                 break;
 327         }
 328
 329         /*
 330          * If changes have occurred, and if we have not sent a broadcast
 331          * recently, send a dynamic update.  This update is sent only
 332          * on interfaces other than the one on which we received notice
 333          * of the change.  If we are within MIN_WAITTIME of a full update,
 334          * don't bother sending; if we just sent a dynamic update
 335          * and set a timer (nextbcast), delay until that time.
 336          * If we just sent a full update, delay the dynamic update.
 337          * Set a timer for a randomized value to suppress additional
 338          * dynamic updates until it expires; if we delayed sending
 339          * the current changes, set needupdate.
 340          */
 341         if (changes && supplier &&
 342            now.tv_sec - lastfullupdate.tv_sec < SUPPLY_INTERVAL-MAX_WAITTIME) {
 343                 u_long delay;
 344                 extern long random();
 345
 346                 if (now.tv_sec - lastbcast.tv_sec >= MIN_WAITTIME &&
 347                     timercmp(&nextbcast, &now, <)) {
 348                         if (traceactions)
 349                                 fprintf(ftrace, "send dynamic update\n");
 350                         toall(supply, RTS_CHANGED, ifp);
 351                         lastbcast = now;
 352                         needupdate = 0;
 353                         nextbcast.tv_sec = 0;
 354                 } else {
 355                         needupdate++;
 356                         if (traceactions)
 357                                 fprintf(ftrace, "delay dynamic update\n");
 358                 }
 359 #define RANDOMDELAY()   (MIN_WAITTIME * 1000000 + \
 360                 (u_long)random() % ((MAX_WAITTIME - MIN_WAITTIME) * 1000000))
 361
 362                 if (nextbcast.tv_sec == 0) {
 363                         delay = RANDOMDELAY();
 364                         if (traceactions)
 365                                 fprintf(ftrace,
 366                                     "inhibit dynamic update for %d usec\n",
 367                                     delay);
 368                         nextbcast.tv_sec = delay / 1000000;
 369                         nextbcast.tv_usec = delay % 1000000;
 370                         timevaladd(&nextbcast, &now);
 371                         /*
 372                          * If the next possibly dynamic update
 373                          * is within MIN_WAITTIME of the next full update,
 374                          * force the delay past the full update,
 375                          * or we might send a dynamic update just before
 376                          * the full update.
 377                          */
 378                         if (nextbcast.tv_sec > lastfullupdate.tv_sec +
 379                             SUPPLY_INTERVAL - MIN_WAITTIME)
 380                                 nextbcast.tv_sec = lastfullupdate.tv_sec +
 381                                     SUPPLY_INTERVAL + 1;
 382                 }
 383         }
 384 }