sbin/routed/output.c

   1 /*
   2  * Copyright (c) 1983, 1988, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgment:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * $FreeBSD: src/sbin/routed/output.c,v 1.5.2.1 2000/08/14 17:00:03 sheldonh Exp $
  34  * $DragonFly: src/sbin/routed/output.c,v 1.5 2005/03/16 21:21:34 cpressey Exp $
  35  */
  36
  37 #include "defs.h"
  38
  39 #if !defined(sgi) && !defined(__NetBSD__)
  40 static char sccsid[] __attribute__((unused)) = "@(#)output.c    8.1 (Berkeley) 6/5/93";
  41 #elif defined(__NetBSD__)
  42 __RCSID("$NetBSD$");
  43 #endif
  44 #ident "$FreeBSD: src/sbin/routed/output.c,v 1.5.2.1 2000/08/14 17:00:03 sheldonh Exp $"
  45
  46
  47 u_int update_seqno;
  48
  49
  50 /* walk the tree of routes with this for output
  51  */
  52 struct {
  53         struct sockaddr_in to;
  54         naddr   to_mask;
  55         naddr   to_net;
  56         naddr   to_std_mask;
  57         naddr   to_std_net;
  58         struct interface *ifp;          /* usually output interface */
  59         struct auth *a;
  60         char    metric;                 /* adjust metrics by interface */
  61         int     npackets;
  62         int     gen_limit;
  63         u_int   state;
  64 #define     WS_ST_FLASH     0x001       /* send only changed routes */
  65 #define     WS_ST_RIP2_ALL  0x002       /* send full featured RIPv2 */
  66 #define     WS_ST_AG        0x004       /* ok to aggregate subnets */
  67 #define     WS_ST_SUPER_AG  0x008       /* ok to aggregate networks */
  68 #define     WS_ST_QUERY     0x010       /* responding to a query */
  69 #define     WS_ST_TO_ON_NET 0x020       /* sending onto one of our nets */
  70 #define     WS_ST_DEFAULT   0x040       /* faking a default */
  71 } ws;
  72
  73 /* A buffer for what can be heard by both RIPv1 and RIPv2 listeners */
  74 struct ws_buf v12buf;
  75 union pkt_buf ripv12_buf;
  76
  77 /* Another for only RIPv2 listeners */
  78 struct ws_buf v2buf;
  79 union pkt_buf rip_v2_buf;
  80
  81
  82
  83 void
  84 bufinit(void)
  85 {
  86         ripv12_buf.rip.rip_cmd = RIPCMD_RESPONSE;
  87         v12buf.buf = &ripv12_buf.rip;
  88         v12buf.base = &v12buf.buf->rip_nets[0];
  89
  90         rip_v2_buf.rip.rip_cmd = RIPCMD_RESPONSE;
  91         rip_v2_buf.rip.rip_vers = RIPv2;
  92         v2buf.buf = &rip_v2_buf.rip;
  93         v2buf.base = &v2buf.buf->rip_nets[0];
  94 }
  95
  96
  97 /* Send the contents of the global buffer via the non-multicast socket
  98  */
  99 int                                     /* <0 on failure */
 100 output(enum output_type type,
 101        struct sockaddr_in *dst,         /* send to here */
 102        struct interface *ifp,
 103        struct rip *buf,
 104        int size)                        /* this many bytes */
 105 {
 106         struct sockaddr_in in;
 107         int flags;
 108         const char *msg;
 109         int res;
 110         naddr tgt_mcast;
 111         int soc;
 112         int serrno;
 113
 114         in = *dst;
 115         if (in.sin_port == 0)
 116                 in.sin_port = htons(RIP_PORT);
 117 #ifdef _HAVE_SIN_LEN
 118         if (in.sin_len == 0)
 119                 in.sin_len = sizeof(in);
 120 #endif
 121
 122         soc = rip_sock;
 123         flags = 0;
 124
 125         switch (type) {
 126         case OUT_QUERY:
 127                 msg = "Answer Query";
 128                 if (soc < 0)
 129                         soc = ifp->int_rip_sock;
 130                 break;
 131         case OUT_UNICAST:
 132                 msg = "Send";
 133                 if (soc < 0)
 134                         soc = ifp->int_rip_sock;
 135                 flags = MSG_DONTROUTE;
 136                 break;
 137         case OUT_BROADCAST:
 138                 if (ifp->int_if_flags & IFF_POINTOPOINT) {
 139                         msg = "Send";
 140                 } else {
 141                         msg = "Send bcast";
 142                 }
 143                 flags = MSG_DONTROUTE;
 144                 break;
 145         case OUT_MULTICAST:
 146                 if (ifp->int_if_flags & IFF_POINTOPOINT) {
 147                         msg = "Send pt-to-pt";
 148                 } else if (ifp->int_state & IS_DUP) {
 149                         trace_act("abort multicast output via %s"
 150                                   " with duplicate address",
 151                                   ifp->int_name);
 152                         return 0;
 153                 } else {
 154                         msg = "Send mcast";
 155                         if (rip_sock_mcast != ifp) {
 156 #ifdef MCAST_PPP_BUG
 157                                 /* Do not specify the primary interface
 158                                  * explicitly if we have the multicast
 159                                  * point-to-point kernel bug, since the
 160                                  * kernel will do the wrong thing if the
 161                                  * local address of a point-to-point link
 162                                  * is the same as the address of an ordinary
 163                                  * interface.
 164                                  */
 165                                 if (ifp->int_addr == myaddr) {
 166                                         tgt_mcast = 0;
 167                                 } else
 168 #endif
 169                                 tgt_mcast = ifp->int_addr;
 170                                 if (0 > setsockopt(rip_sock,
 171                                                    IPPROTO_IP, IP_MULTICAST_IF,
 172                                                    &tgt_mcast,
 173                                                    sizeof(tgt_mcast))) {
 174                                         serrno = errno;
 175                                         LOGERR("setsockopt(rip_sock,"
 176                                                "IP_MULTICAST_IF)");
 177                                         errno = serrno;
 178                                         ifp = 0;
 179                                         return -1;
 180                                 }
 181                                 rip_sock_mcast = ifp;
 182                         }
 183                         in.sin_addr.s_addr = htonl(INADDR_RIP_GROUP);
 184                 }
 185                 break;
 186
 187         case NO_OUT_MULTICAST:
 188         case NO_OUT_RIPV2:
 189         default:
 190 #ifdef DEBUG
 191                 abort();
 192 #endif
 193                 return -1;
 194         }
 195
 196         trace_rip(msg, "to", &in, ifp, buf, size);
 197
 198         res = sendto(soc, buf, size, flags,
 199                      (struct sockaddr *)&in, sizeof(in));
 200         if (res < 0
 201             && (ifp == 0 || !(ifp->int_state & IS_BROKE))) {
 202                 serrno = errno;
 203                 msglog("%s sendto(%s%s%s.%d): %s", msg,
 204                        ifp != 0 ? ifp->int_name : "",
 205                        ifp != 0 ? ", " : "",
 206                        inet_ntoa(in.sin_addr),
 207                        ntohs(in.sin_port),
 208                        strerror(errno));
 209                 errno = serrno;
 210         }
 211
 212         return res;
 213 }
 214
 215
 216 /* Find the first key for a packet to send.
 217  * Try for a key that is eligible and has not expired, but settle for
 218  * the last key if they have all expired.
 219  * If no key is ready yet, give up.
 220  */
 221 struct auth *
 222 find_auth(struct interface *ifp)
 223 {
 224         struct auth *ap, *res;
 225         int i;
 226
 227
 228         if (ifp == 0)
 229                 return 0;
 230
 231         res = 0;
 232         ap = ifp->int_auth;
 233         for (i = 0; i < MAX_AUTH_KEYS; i++, ap++) {
 234                 /* stop looking after the last key */
 235                 if (ap->type == RIP_AUTH_NONE)
 236                         break;
 237
 238                 /* ignore keys that are not ready yet */
 239                 if ((u_long)ap->start > (u_long)clk.tv_sec)
 240                         continue;
 241
 242                 if ((u_long)ap->end < (u_long)clk.tv_sec) {
 243                         /* note best expired password as a fall-back */
 244                         if (res == 0 || (u_long)ap->end > (u_long)res->end)
 245                                 res = ap;
 246                         continue;
 247                 }
 248
 249                 /* note key with the best future */
 250                 if (res == 0 || (u_long)res->end < (u_long)ap->end)
 251                         res = ap;
 252         }
 253         return res;
 254 }
 255
 256
 257 void
 258 clr_ws_buf(struct ws_buf *wb,
 259            struct auth *ap)
 260 {
 261         struct netauth *na;
 262
 263         wb->lim = wb->base + NETS_LEN;
 264         wb->n = wb->base;
 265         memset(wb->n, 0, NETS_LEN*sizeof(*wb->n));
 266
 267         /* (start to) install authentication if appropriate
 268          */
 269         if (ap == 0)
 270                 return;
 271
 272         na = (struct netauth*)wb->n;
 273         if (ap->type == RIP_AUTH_PW) {
 274                 na->a_family = RIP_AF_AUTH;
 275                 na->a_type = RIP_AUTH_PW;
 276                 memcpy(na->au.au_pw, ap->key, sizeof(na->au.au_pw));
 277                 wb->n++;
 278
 279         } else if (ap->type ==  RIP_AUTH_MD5) {
 280                 na->a_family = RIP_AF_AUTH;
 281                 na->a_type = RIP_AUTH_MD5;
 282                 na->au.a_md5.md5_keyid = ap->keyid;
 283                 na->au.a_md5.md5_auth_len = RIP_AUTH_MD5_LEN;
 284                 na->au.a_md5.md5_seqno = htonl(clk.tv_sec);
 285                 wb->n++;
 286                 wb->lim--;              /* make room for trailer */
 287         }
 288 }
 289
 290
 291 void
 292 end_md5_auth(struct ws_buf *wb,
 293              struct auth *ap)
 294 {
 295         struct netauth *na, *na2;
 296         MD5_CTX md5_ctx;
 297         int len;
 298
 299
 300         na = (struct netauth*)wb->base;
 301         na2 = (struct netauth*)wb->n;
 302         len = (char *)na2-(char *)wb->buf;
 303         na2->a_family = RIP_AF_AUTH;
 304         na2->a_type = htons(1);
 305         na->au.a_md5.md5_pkt_len = htons(len);
 306         MD5Init(&md5_ctx);
 307         MD5Update(&md5_ctx, (u_char *)wb->buf, len);
 308         MD5Update(&md5_ctx, ap->key, RIP_AUTH_MD5_LEN);
 309         MD5Final(na2->au.au_pw, &md5_ctx);
 310         wb->n++;
 311 }
 312
 313
 314 /* Send the buffer
 315  */
 316 static void
 317 supply_write(struct ws_buf *wb)
 318 {
 319         /* Output multicast only if legal.
 320          * If we would multicast and it would be illegal, then discard the
 321          * packet.
 322          */
 323         switch (wb->type) {
 324         case NO_OUT_MULTICAST:
 325                 trace_pkt("skip multicast to %s because impossible",
 326                           naddr_ntoa(ws.to.sin_addr.s_addr));
 327                 break;
 328         case NO_OUT_RIPV2:
 329                 break;
 330         default:
 331                 if (ws.a != 0 && ws.a->type == RIP_AUTH_MD5)
 332                         end_md5_auth(wb,ws.a);
 333                 if (output(wb->type, &ws.to, ws.ifp, wb->buf,
 334                            ((char *)wb->n - (char*)wb->buf)) < 0
 335                     && ws.ifp != 0)
 336                         if_sick(ws.ifp);
 337                 ws.npackets++;
 338                 break;
 339         }
 340
 341         clr_ws_buf(wb,ws.a);
 342 }
 343
 344
 345 /* put an entry into the packet
 346  */
 347 static void
 348 supply_out(struct ag_info *ag)
 349 {
 350         int i;
 351         naddr mask, v1_mask, dst_h, ddst_h = 0;
 352         struct ws_buf *wb;
 353
 354
 355         /* Skip this route if doing a flash update and it and the routes
 356          * it aggregates have not changed recently.
 357          */
 358         if (ag->ag_seqno < update_seqno
 359             && (ws.state & WS_ST_FLASH))
 360                 return;
 361
 362         dst_h = ag->ag_dst_h;
 363         mask = ag->ag_mask;
 364         v1_mask = ripv1_mask_host(htonl(dst_h),
 365                                   (ws.state & WS_ST_TO_ON_NET) ? ws.ifp : 0);
 366         i = 0;
 367
 368         /* If we are sending RIPv2 packets that cannot (or must not) be
 369          * heard by RIPv1 listeners, do not worry about sub- or supernets.
 370          * Subnets (from other networks) can only be sent via multicast.
 371          * A pair of subnet routes might have been promoted so that they
 372          * are legal to send by RIPv1.
 373          * If RIPv1 is off, use the multicast buffer.
 374          */
 375         if ((ws.state & WS_ST_RIP2_ALL)
 376             || ((ag->ag_state & AGS_RIPV2) && v1_mask != mask)) {
 377                 /* use the RIPv2-only buffer */
 378                 wb = &v2buf;
 379
 380         } else {
 381                 /* use the RIPv1-or-RIPv2 buffer */
 382                 wb = &v12buf;
 383
 384                 /* Convert supernet route into corresponding set of network
 385                  * routes for RIPv1, but leave non-contiguous netmasks
 386                  * to ag_check().
 387                  */
 388                 if (v1_mask > mask
 389                     && mask + (mask & -mask) == 0) {
 390                         ddst_h = v1_mask & -v1_mask;
 391                         i = (v1_mask & ~mask)/ddst_h;
 392
 393                         if (i > ws.gen_limit) {
 394                                 /* Punt if we would have to generate an
 395                                  * unreasonable number of routes.
 396                                  */
 397                                 if (TRACECONTENTS)
 398                                         trace_misc("sending %s-->%s as 1"
 399                                                    " instead of %d routes",
 400                                                    addrname(htonl(dst_h), mask,
 401                                                         1),
 402                                                    naddr_ntoa(ws.to.sin_addr
 403                                                         .s_addr),
 404                                                    i+1);
 405                                 i = 0;
 406
 407                         } else {
 408                                 mask = v1_mask;
 409                                 ws.gen_limit -= i;
 410                         }
 411                 }
 412         }
 413
 414         do {
 415                 wb->n->n_family = RIP_AF_INET;
 416                 wb->n->n_dst = htonl(dst_h);
 417                 /* If the route is from router-discovery or we are
 418                  * shutting down, admit only a bad metric.
 419                  */
 420                 wb->n->n_metric = ((stopint || ag->ag_metric < 1)
 421                                    ? HOPCNT_INFINITY
 422                                    : ag->ag_metric);
 423                 wb->n->n_metric = htonl(wb->n->n_metric);
 424                 /* Any non-zero bits in the supposedly unused RIPv1 fields
 425                  * cause the old `routed` to ignore the route.
 426                  * That means the mask and so forth cannot be sent
 427                  * in the hybrid RIPv1/RIPv2 mode.
 428                  */
 429                 if (ws.state & WS_ST_RIP2_ALL) {
 430                         if (ag->ag_nhop != 0
 431                             && ((ws.state & WS_ST_QUERY)
 432                                 || (ag->ag_nhop != ws.ifp->int_addr
 433                                     && on_net(ag->ag_nhop,
 434                                               ws.ifp->int_net,
 435                                               ws.ifp->int_mask))))
 436                                 wb->n->n_nhop = ag->ag_nhop;
 437                         wb->n->n_mask = htonl(mask);
 438                         wb->n->n_tag = ag->ag_tag;
 439                 }
 440                 dst_h += ddst_h;
 441
 442                 if (++wb->n >= wb->lim)
 443                         supply_write(wb);
 444         } while (i-- != 0);
 445 }
 446
 447
 448 /* supply one route from the table
 449  */
 450 /* ARGSUSED */
 451 static int
 452 walk_supply(struct radix_node *rn,
 453             struct walkarg *argp UNUSED)
 454 {
 455 #define RT ((struct rt_entry *)rn)
 456         u_short ags;
 457         char metric, pref;
 458         naddr dst, nhop;
 459         struct rt_spare *rts;
 460         int i;
 461
 462
 463         /* Do not advertise external remote interfaces or passive interfaces.
 464          */
 465         if ((RT->rt_state & RS_IF)
 466             && RT->rt_ifp != 0
 467             && (RT->rt_ifp->int_state & IS_PASSIVE)
 468             && !(RT->rt_state & RS_MHOME))
 469                 return 0;
 470
 471         /* If being quiet about our ability to forward, then
 472          * do not say anything unless responding to a query,
 473          * except about our main interface.
 474          */
 475         if (!supplier && !(ws.state & WS_ST_QUERY)
 476             && !(RT->rt_state & RS_MHOME))
 477                 return 0;
 478
 479         dst = RT->rt_dst;
 480
 481         /* do not collide with the fake default route */
 482         if (dst == RIP_DEFAULT
 483             && (ws.state & WS_ST_DEFAULT))
 484                 return 0;
 485
 486         if (RT->rt_state & RS_NET_SYN) {
 487                 if (RT->rt_state & RS_NET_INT) {
 488                         /* Do not send manual synthetic network routes
 489                          * into the subnet.
 490                          */
 491                         if (on_net(ws.to.sin_addr.s_addr,
 492                                    ntohl(dst), RT->rt_mask))
 493                                 return 0;
 494
 495                 } else {
 496                         /* Do not send automatic synthetic network routes
 497                          * if they are not needed because no RIPv1 listeners
 498                          * can hear them.
 499                          */
 500                         if (ws.state & WS_ST_RIP2_ALL)
 501                                 return 0;
 502
 503                         /* Do not send automatic synthetic network routes to
 504                          * the real subnet.
 505                          */
 506                         if (on_net(ws.to.sin_addr.s_addr,
 507                                    ntohl(dst), RT->rt_mask))
 508                                 return 0;
 509                 }
 510                 nhop = 0;
 511
 512         } else {
 513                 /* Advertise the next hop if this is not a route for one
 514                  * of our interfaces and the next hop is on the same
 515                  * network as the target.
 516                  * The final determination is made by supply_out().
 517                  */
 518                 if (!(RT->rt_state & RS_IF)
 519                     && RT->rt_gate != myaddr
 520                     && RT->rt_gate != loopaddr)
 521                         nhop = RT->rt_gate;
 522                 else
 523                         nhop = 0;
 524         }
 525
 526         metric = RT->rt_metric;
 527         ags = 0;
 528
 529         if (RT->rt_state & RS_MHOME) {
 530                 /* retain host route of multi-homed servers */
 531                 ;
 532
 533         } else if (RT_ISHOST(RT)) {
 534                 /* We should always suppress (into existing network routes)
 535                  * the host routes for the local end of our point-to-point
 536                  * links.
 537                  * If we are suppressing host routes in general, then do so.
 538                  * Avoid advertising host routes onto their own network,
 539                  * where they should be handled by proxy-ARP.
 540                  */
 541                 if ((RT->rt_state & RS_LOCAL)
 542                     || ridhosts
 543                     || on_net(dst, ws.to_net, ws.to_mask))
 544                         ags |= AGS_SUPPRESS;
 545
 546                 /* Aggregate stray host routes into network routes if allowed.
 547                  * We cannot aggregate host routes into small network routes
 548                  * without confusing RIPv1 listeners into thinking the
 549                  * network routes are host routes.
 550                  */
 551                 if ((ws.state & WS_ST_AG)
 552                     && !(ws.state & WS_ST_RIP2_ALL))
 553                         ags |= AGS_AGGREGATE;
 554
 555         } else {
 556                 /* Always suppress network routes into other, existing
 557                  * network routes
 558                  */
 559                 ags |= AGS_SUPPRESS;
 560
 561                 /* Generate supernets if allowed.
 562                  * If we can be heard by RIPv1 systems, we will
 563                  * later convert back to ordinary nets.
 564                  * This unifies dealing with received supernets.
 565                  */
 566                 if ((ws.state & WS_ST_AG)
 567                     && ((RT->rt_state & RS_SUBNET)
 568                         || (ws.state & WS_ST_SUPER_AG)))
 569                         ags |= AGS_AGGREGATE;
 570         }
 571
 572         /* Do not send RIPv1 advertisements of subnets to other
 573          * networks. If possible, multicast them by RIPv2.
 574          */
 575         if ((RT->rt_state & RS_SUBNET)
 576             && !(ws.state & WS_ST_RIP2_ALL)
 577             && !on_net(dst, ws.to_std_net, ws.to_std_mask))
 578                 ags |= AGS_RIPV2 | AGS_AGGREGATE;
 579
 580
 581         /* Do not send a route back to where it came from, except in
 582          * response to a query.  This is "split-horizon".  That means not
 583          * advertising back to the same network and so via the same interface.
 584          *
 585          * We want to suppress routes that might have been fragmented
 586          * from this route by a RIPv1 router and sent back to us, and so we
 587          * cannot forget this route here.  Let the split-horizon route
 588          * suppress the fragmented routes and then itself be forgotten.
 589          *
 590          * Include the routes for both ends of point-to-point interfaces
 591          * among those suppressed by split-horizon, since the other side
 592          * should knows them as well as we do.
 593          *
 594          * Notice spare routes with the same metric that we are about to
 595          * advertise, to split the horizon on redundant, inactive paths.
 596          */
 597         if (ws.ifp != 0
 598             && !(ws.state & WS_ST_QUERY)
 599             && (ws.state & WS_ST_TO_ON_NET)
 600             && (!(RT->rt_state & RS_IF)
 601                 || ws.ifp->int_if_flags & IFF_POINTOPOINT)) {
 602                 for (rts = RT->rt_spares, i = NUM_SPARES; i != 0; i--, rts++) {
 603                         if (rts->rts_metric > metric
 604                             || rts->rts_ifp != ws.ifp)
 605                                 continue;
 606
 607                         /* If we do not mark the route with AGS_SPLIT_HZ here,
 608                          * it will be poisoned-reverse, or advertised back
 609                          * toward its source with an infinite metric.
 610                          * If we have recently advertised the route with a
 611                          * better metric than we now have, then we should
 612                          * poison-reverse the route before suppressing it for
 613                          * split-horizon.
 614                          *
 615                          * In almost all cases, if there is no spare for the
 616                          * route then it is either old and dead or a brand
 617                          * new route. If it is brand new, there is no need
 618                          * for poison-reverse. If it is old and dead, it
 619                          * is already poisoned.
 620                          */
 621                         if (RT->rt_poison_time < now_expire
 622                             || RT->rt_poison_metric >= metric
 623                             || RT->rt_spares[1].rts_gate == 0) {
 624                                 ags |= AGS_SPLIT_HZ;
 625                                 ags &= ~AGS_SUPPRESS;
 626                         }
 627                         metric = HOPCNT_INFINITY;
 628                         break;
 629                 }
 630         }
 631
 632         /* Keep track of the best metric with which the
 633          * route has been advertised recently.
 634          */
 635         if (RT->rt_poison_metric >= metric
 636             || RT->rt_poison_time < now_expire) {
 637                 RT->rt_poison_time = now.tv_sec;
 638                 RT->rt_poison_metric = metric;
 639         }
 640
 641         /* Adjust the outgoing metric by the cost of the link.
 642          * Avoid aggregation when a route is counting to infinity.
 643          */
 644         pref = RT->rt_poison_metric + ws.metric;
 645         metric += ws.metric;
 646
 647         /* Do not advertise stable routes that will be ignored,
 648          * unless we are answering a query.
 649          * If the route recently was advertised with a metric that
 650          * would have been less than infinity through this interface,
 651          * we need to continue to advertise it in order to poison it.
 652          */
 653         if (metric >= HOPCNT_INFINITY) {
 654                 if (!(ws.state & WS_ST_QUERY)
 655                     && (pref >= HOPCNT_INFINITY
 656                         || RT->rt_poison_time < now_garbage))
 657                         return 0;
 658
 659                 metric = HOPCNT_INFINITY;
 660         }
 661
 662         ag_check(dst, RT->rt_mask, 0, nhop, metric, pref,
 663                  RT->rt_seqno, RT->rt_tag, ags, supply_out);
 664         return 0;
 665 #undef RT
 666 }
 667
 668
 669 /* Supply dst with the contents of the routing tables.
 670  * If this won't fit in one packet, chop it up into several.
 671  */
 672 void
 673 supply(struct sockaddr_in *dst,
 674        struct interface *ifp,           /* output interface */
 675        enum output_type type,
 676        int flash,                       /* 1=flash update */
 677        int vers,                        /* RIP version */
 678        int passwd_ok)                   /* OK to include cleartext password */
 679 {
 680         struct rt_entry *rt;
 681         int def_metric;
 682
 683
 684         ws.state = 0;
 685         ws.gen_limit = 1024;
 686
 687         ws.to = *dst;
 688         ws.to_std_mask = std_mask(ws.to.sin_addr.s_addr);
 689         ws.to_std_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_std_mask;
 690
 691         if (ifp != 0) {
 692                 ws.to_mask = ifp->int_mask;
 693                 ws.to_net = ifp->int_net;
 694                 if (on_net(ws.to.sin_addr.s_addr, ws.to_net, ws.to_mask))
 695                         ws.state |= WS_ST_TO_ON_NET;
 696
 697         } else {
 698                 ws.to_mask = ripv1_mask_net(ws.to.sin_addr.s_addr, 0);
 699                 ws.to_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_mask;
 700                 rt = rtfind(dst->sin_addr.s_addr);
 701                 if (rt)
 702                         ifp = rt->rt_ifp;
 703         }
 704
 705         ws.npackets = 0;
 706         if (flash)
 707                 ws.state |= WS_ST_FLASH;
 708
 709         if ((ws.ifp = ifp) == 0) {
 710                 ws.metric = 1;
 711         } else {
 712                 /* Adjust the advertised metric by the outgoing interface
 713                  * metric.
 714                  */
 715                 ws.metric = ifp->int_metric+1;
 716         }
 717
 718         ripv12_buf.rip.rip_vers = vers;
 719
 720         switch (type) {
 721         case OUT_MULTICAST:
 722                 if (ifp->int_if_flags & IFF_MULTICAST)
 723                         v2buf.type = OUT_MULTICAST;
 724                 else
 725                         v2buf.type = NO_OUT_MULTICAST;
 726                 v12buf.type = OUT_BROADCAST;
 727                 break;
 728
 729         case OUT_QUERY:
 730                 ws.state |= WS_ST_QUERY;
 731                 /* fall through */
 732         case OUT_BROADCAST:
 733         case OUT_UNICAST:
 734                 v2buf.type = (vers == RIPv2) ? type : NO_OUT_RIPV2;
 735                 v12buf.type = type;
 736                 break;
 737
 738         case NO_OUT_MULTICAST:
 739         case NO_OUT_RIPV2:
 740                 break;                  /* no output */
 741         }
 742
 743         if (vers == RIPv2) {
 744                 /* full RIPv2 only if cannot be heard by RIPv1 listeners */
 745                 if (type != OUT_BROADCAST)
 746                         ws.state |= WS_ST_RIP2_ALL;
 747                 if ((ws.state & WS_ST_QUERY)
 748                     || !(ws.state & WS_ST_TO_ON_NET)) {
 749                         ws.state |= (WS_ST_AG | WS_ST_SUPER_AG);
 750                 } else if (ifp == 0 || !(ifp->int_state & IS_NO_AG)) {
 751                         ws.state |= WS_ST_AG;
 752                         if (type != OUT_BROADCAST
 753                             && (ifp == 0
 754                                 || !(ifp->int_state & IS_NO_SUPER_AG)))
 755                                 ws.state |= WS_ST_SUPER_AG;
 756                 }
 757         }
 758
 759         ws.a = (vers == RIPv2) ? find_auth(ifp) : 0;
 760         if (!passwd_ok && ws.a != 0 && ws.a->type == RIP_AUTH_PW)
 761                 ws.a = 0;
 762         clr_ws_buf(&v12buf,ws.a);
 763         clr_ws_buf(&v2buf,ws.a);
 764
 765         /*  Fake a default route if asked and if there is not already
 766          * a better, real default route.
 767          */
 768         if (supplier && (def_metric = ifp->int_d_metric) != 0) {
 769                 if (0 == (rt = rtget(RIP_DEFAULT, 0))
 770                     || rt->rt_metric+ws.metric >= def_metric) {
 771                         ws.state |= WS_ST_DEFAULT;
 772                         ag_check(0, 0, 0, 0, def_metric, def_metric,
 773                                  0, 0, 0, supply_out);
 774                 } else {
 775                         def_metric = rt->rt_metric+ws.metric;
 776                 }
 777
 778                 /* If both RIPv2 and the poor-man's router discovery
 779                  * kludge are on, arrange to advertise an extra
 780                  * default route via RIPv1.
 781                  */
 782                 if ((ws.state & WS_ST_RIP2_ALL)
 783                     && (ifp->int_state & IS_PM_RDISC)) {
 784                         ripv12_buf.rip.rip_vers = RIPv1;
 785                         v12buf.n->n_family = RIP_AF_INET;
 786                         v12buf.n->n_dst = htonl(RIP_DEFAULT);
 787                         v12buf.n->n_metric = htonl(def_metric);
 788                         v12buf.n++;
 789                 }
 790         }
 791
 792         rn_walktree(rhead, walk_supply, 0);
 793         ag_flush(0,0,supply_out);
 794
 795         /* Flush the packet buffers, provided they are not empty and
 796          * do not contain only the password.
 797          */
 798         if (v12buf.n != v12buf.base
 799             && (v12buf.n > v12buf.base+1
 800                 || v12buf.base->n_family != RIP_AF_AUTH))
 801                 supply_write(&v12buf);
 802         if (v2buf.n != v2buf.base
 803             && (v2buf.n > v2buf.base+1
 804                 || v2buf.base->n_family != RIP_AF_AUTH))
 805                 supply_write(&v2buf);
 806
 807         /* If we sent nothing and this is an answer to a query, send
 808          * an empty buffer.
 809          */
 810         if (ws.npackets == 0
 811             && (ws.state & WS_ST_QUERY))
 812                 supply_write(&v12buf);
 813 }
 814
 815
 816 /* send all of the routing table or just do a flash update
 817  */
 818 void
 819 rip_bcast(int flash)
 820 {
 821 #ifdef _HAVE_SIN_LEN
 822         static struct sockaddr_in dst = {sizeof(dst), AF_INET, 0, {0}, {0}};
 823 #else
 824         static struct sockaddr_in dst = {AF_INET};
 825 #endif
 826         struct interface *ifp;
 827         enum output_type type;
 828         int vers;
 829         struct timeval rtime;
 830
 831
 832         need_flash = 0;
 833         intvl_random(&rtime, MIN_WAITTIME, MAX_WAITTIME);
 834         no_flash = rtime;
 835         timevaladd(&no_flash, &now);
 836
 837         if (rip_sock < 0)
 838                 return;
 839
 840         trace_act("send %s and inhibit dynamic updates for %.3f sec",
 841                   flash ? "dynamic update" : "all routes",
 842                   rtime.tv_sec + ((float)rtime.tv_usec)/1000000.0);
 843
 844         for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
 845                 /* Skip interfaces not doing RIP.
 846                  * Do try broken interfaces to see if they have healed.
 847                  */
 848                 if (IS_RIP_OUT_OFF(ifp->int_state))
 849                         continue;
 850
 851                 /* skip turned off interfaces */
 852                 if (!iff_up(ifp->int_if_flags))
 853                         continue;
 854
 855                 vers = (ifp->int_state & IS_NO_RIPV1_OUT) ? RIPv2 : RIPv1;
 856
 857                 if (ifp->int_if_flags & IFF_BROADCAST) {
 858                         /* ordinary, hardware interface */
 859                         dst.sin_addr.s_addr = ifp->int_brdaddr;
 860
 861                         if (vers == RIPv2
 862                             && !(ifp->int_state  & IS_NO_RIP_MCAST)) {
 863                                 type = OUT_MULTICAST;
 864                         } else {
 865                                 type = OUT_BROADCAST;
 866                         }
 867
 868                 } else if (ifp->int_if_flags & IFF_POINTOPOINT) {
 869                         /* point-to-point hardware interface */
 870                         dst.sin_addr.s_addr = ifp->int_dstaddr;
 871                         type = OUT_UNICAST;
 872
 873                 } else if (ifp->int_state & IS_REMOTE) {
 874                         /* remote interface */
 875                         dst.sin_addr.s_addr = ifp->int_addr;
 876                         type = OUT_UNICAST;
 877
 878                 } else {
 879                         /* ATM, HIPPI, etc. */
 880                         continue;
 881                 }
 882
 883                 supply(&dst, ifp, type, flash, vers, 1);
 884         }
 885
 886         update_seqno++;                 /* all routes are up to date */
 887 }
 888
 889
 890 /* Ask for routes
 891  * Do it only once to an interface, and not even after the interface
 892  * was broken and recovered.
 893  */
 894 void
 895 rip_query(void)
 896 {
 897 #ifdef _HAVE_SIN_LEN
 898         static struct sockaddr_in dst = {sizeof(dst), AF_INET, 0, {0}, {0}};
 899 #else
 900         static struct sockaddr_in dst = {AF_INET};
 901 #endif
 902         struct interface *ifp;
 903         struct rip buf;
 904         enum output_type type;
 905
 906
 907         if (rip_sock < 0)
 908                 return;
 909
 910         memset(&buf, 0, sizeof(buf));
 911
 912         for (ifp = ifnet; ifp; ifp = ifp->int_next) {
 913                 /* Skip interfaces those already queried.
 914                  * Do not ask via interfaces through which we don't
 915                  * accept input.  Do not ask via interfaces that cannot
 916                  * send RIP packets.
 917                  * Do try broken interfaces to see if they have healed.
 918                  */
 919                 if (IS_RIP_IN_OFF(ifp->int_state)
 920                     || ifp->int_query_time != NEVER)
 921                         continue;
 922
 923                 /* skip turned off interfaces */
 924                 if (!iff_up(ifp->int_if_flags))
 925                         continue;
 926
 927                 buf.rip_vers = (ifp->int_state&IS_NO_RIPV1_OUT) ? RIPv2:RIPv1;
 928                 buf.rip_cmd = RIPCMD_REQUEST;
 929                 buf.rip_nets[0].n_family = RIP_AF_UNSPEC;
 930                 buf.rip_nets[0].n_metric = htonl(HOPCNT_INFINITY);
 931
 932                 /* Send a RIPv1 query only if allowed and if we will
 933                  * listen to RIPv1 routers.
 934                  */
 935                 if ((ifp->int_state & IS_NO_RIPV1_OUT)
 936                     || (ifp->int_state & IS_NO_RIPV1_IN)) {
 937                         buf.rip_vers = RIPv2;
 938                 } else {
 939                         buf.rip_vers = RIPv1;
 940                 }
 941
 942                 if (ifp->int_if_flags & IFF_BROADCAST) {
 943                         /* ordinary, hardware interface */
 944                         dst.sin_addr.s_addr = ifp->int_brdaddr;
 945
 946                         /* Broadcast RIPv1 queries and RIPv2 queries
 947                          * when the hardware cannot multicast.
 948                          */
 949                         if (buf.rip_vers == RIPv2
 950                             && (ifp->int_if_flags & IFF_MULTICAST)
 951                             && !(ifp->int_state  & IS_NO_RIP_MCAST)) {
 952                                 type = OUT_MULTICAST;
 953                         } else {
 954                                 type = OUT_BROADCAST;
 955                         }
 956
 957                 } else if (ifp->int_if_flags & IFF_POINTOPOINT) {
 958                         /* point-to-point hardware interface */
 959                         dst.sin_addr.s_addr = ifp->int_dstaddr;
 960                         type = OUT_UNICAST;
 961
 962                 } else if (ifp->int_state & IS_REMOTE) {
 963                         /* remote interface */
 964                         dst.sin_addr.s_addr = ifp->int_addr;
 965                         type = OUT_UNICAST;
 966
 967                 } else {
 968                         /* ATM, HIPPI, etc. */
 969                         continue;
 970                 }
 971
 972                 ifp->int_query_time = now.tv_sec+SUPPLY_INTERVAL;
 973                 if (output(type, &dst, ifp, &buf, sizeof(buf)) < 0)
 974                         if_sick(ifp);
 975         }
 976 }