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