sbin/routed/output.c

   1 /*      $NetBSD: output.c,v 1.23 2006/03/18 20:21:50 christos Exp $     */
   2
   3 /*
   4  * Copyright (c) 1983, 1988, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgment:
  17  *      This product includes software developed by the University of
  18  *      California, Berkeley and its contributors.
  19  * 4. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include "defs.h"
  37
  38 #ifdef __NetBSD__
  39 __RCSID("$NetBSD: output.c,v 1.23 2006/03/18 20:21:50 christos Exp $");
  40 #elif defined(__FreeBSD__)
  41 __RCSID("$FreeBSD$");
  42 #else
  43 __RCSID("Revision: 2.27 ");
  44 #ident "Revision: 2.27 "
  45 #endif
  46
  47
  48 u_int update_seqno;
  49
  50
  51 /* walk the tree of routes with this for output
  52  */
  53 struct {
  54         struct sockaddr_in to;
  55         naddr   to_mask;
  56         naddr   to_net;
  57         naddr   to_std_mask;
  58         naddr   to_std_net;
  59         struct interface *ifp;          /* usually output interface */
  60         struct auth *a;
  61         char    metric;                 /* adjust metrics by interface */
  62         int     npackets;
  63         int     gen_limit;
  64         u_int   state;
  65 #define     WS_ST_FLASH     0x001       /* send only changed routes */
  66 #define     WS_ST_RIP2_ALL  0x002       /* send full featured RIPv2 */
  67 #define     WS_ST_AG        0x004       /* ok to aggregate subnets */
  68 #define     WS_ST_SUPER_AG  0x008       /* ok to aggregate networks */
  69 #define     WS_ST_QUERY     0x010       /* responding to a query */
  70 #define     WS_ST_TO_ON_NET 0x020       /* sending onto one of our nets */
  71 #define     WS_ST_DEFAULT   0x040       /* faking a default */
  72 } ws;
  73
  74 /* A buffer for what can be heard by both RIPv1 and RIPv2 listeners */
  75 struct ws_buf v12buf;
  76 union pkt_buf ripv12_buf;
  77
  78 /* Another for only RIPv2 listeners */
  79 struct ws_buf v2buf;
  80 union pkt_buf rip_v2_buf;
  81
  82
  83
  84 void
  85 bufinit(void)
  86 {
  87         ripv12_buf.rip.rip_cmd = RIPCMD_RESPONSE;
  88         v12buf.buf = &ripv12_buf.rip;
  89         v12buf.base = &v12buf.buf->rip_nets[0];
  90
  91         rip_v2_buf.rip.rip_cmd = RIPCMD_RESPONSE;
  92         rip_v2_buf.rip.rip_vers = RIPv2;
  93         v2buf.buf = &rip_v2_buf.rip;
  94         v2buf.base = &v2buf.buf->rip_nets[0];
  95 }
  96
  97
  98 /* Send the contents of the global buffer via the non-multicast socket
  99  */
 100 int                                     /* <0 on failure */
 101 output(enum output_type type,
 102        struct sockaddr_in *dst,         /* send to here */
 103        struct interface *ifp,
 104        struct rip *buf,
 105        int size)                        /* this many bytes */
 106 {
 107         struct sockaddr_in osin;
 108         int flags;
 109         const char *msg;
 110         int res;
 111         naddr tgt_mcast;
 112         int soc;
 113         int serrno;
 114
 115         osin = *dst;
 116         if (osin.sin_port == 0)
 117                 osin.sin_port = htons(RIP_PORT);
 118 #ifdef _HAVE_SIN_LEN
 119         if (osin.sin_len == 0)
 120                 osin.sin_len = sizeof(osin);
 121 #endif
 122
 123         soc = rip_sock;
 124         flags = 0;
 125
 126         switch (type) {
 127         case OUT_QUERY:
 128                 msg = "Answer Query";
 129                 if (soc < 0)
 130                         soc = ifp->int_rip_sock;
 131                 break;
 132         case OUT_UNICAST:
 133                 msg = "Send";
 134                 if (soc < 0)
 135                         soc = ifp->int_rip_sock;
 136                 flags = MSG_DONTROUTE;
 137                 break;
 138         case OUT_BROADCAST:
 139                 if (ifp->int_if_flags & IFF_POINTOPOINT) {
 140                         msg = "Send";
 141                 } else {
 142                         msg = "Send bcast";
 143                 }
 144                 flags = MSG_DONTROUTE;
 145                 break;
 146         case OUT_MULTICAST:
 147                 if (ifp->int_if_flags & IFF_POINTOPOINT) {
 148                         msg = "Send pt-to-pt";
 149                 } else if (ifp->int_state & IS_DUP) {
 150                         trace_act("abort multicast output via %s"
 151                                   " with duplicate address",
 152                                   ifp->int_name);
 153                         return 0;
 154                 } else {
 155                         msg = "Send mcast";
 156                         if (rip_sock_mcast != ifp) {
 157 #ifdef MCAST_IFINDEX
 158                                 /* specify ifindex */
 159                                 tgt_mcast = htonl(ifp->int_index);
 160 #else
 161 #ifdef MCAST_PPP_BUG
 162                                 /* Do not specify the primary interface
 163                                  * explicitly if we have the multicast
 164                                  * point-to-point kernel bug, since the
 165                                  * kernel will do the wrong thing if the
 166                                  * local address of a point-to-point link
 167                                  * is the same as the address of an ordinary
 168                                  * interface.
 169                                  */
 170                                 if (ifp->int_addr == myaddr) {
 171                                         tgt_mcast = 0;
 172                                 } else
 173 #endif
 174                                 tgt_mcast = ifp->int_addr;
 175 #endif
 176                                 if (0 > setsockopt(rip_sock,
 177                                                    IPPROTO_IP, IP_MULTICAST_IF,
 178                                                    &tgt_mcast,
 179                                                    sizeof(tgt_mcast))) {
 180                                         serrno = errno;
 181                                         LOGERR("setsockopt(rip_sock,"
 182                                                "IP_MULTICAST_IF)");
 183                                         errno = serrno;
 184                                         ifp = 0;
 185                                         return -1;
 186                                 }
 187                                 rip_sock_mcast = ifp;
 188                         }
 189                         osin.sin_addr.s_addr = htonl(INADDR_RIP_GROUP);
 190                 }
 191                 break;
 192
 193         case NO_OUT_MULTICAST:
 194         case NO_OUT_RIPV2:
 195         default:
 196 #ifdef DEBUG
 197                 abort();
 198 #endif
 199                 return -1;
 200         }
 201
 202         trace_rip(msg, "to", &osin, ifp, buf, size);
 203
 204         res = sendto(soc, buf, size, flags,
 205                      (struct sockaddr *)&osin, sizeof(osin));
 206         if (res < 0
 207             && (ifp == 0 || !(ifp->int_state & IS_BROKE))) {
 208                 serrno = errno;
 209                 msglog("%s sendto(%s%s%s.%d): %s", msg,
 210                        ifp != 0 ? ifp->int_name : "",
 211                        ifp != 0 ? ", " : "",
 212                        inet_ntoa(osin.sin_addr),
 213                        ntohs(osin.sin_port),
 214                        strerror(errno));
 215                 errno = serrno;
 216         }
 217
 218         return res;
 219 }
 220
 221
 222 /* Find the first key for a packet to send.
 223  * Try for a key that is eligible and has not expired, but settle for
 224  * the last key if they have all expired.
 225  * If no key is ready yet, give up.
 226  */
 227 struct auth *
 228 find_auth(struct interface *ifp)
 229 {
 230         struct auth *ap, *res;
 231         int i;
 232
 233
 234         if (ifp == 0)
 235                 return 0;
 236
 237         res = 0;
 238         ap = ifp->int_auth;
 239         for (i = 0; i < MAX_AUTH_KEYS; i++, ap++) {
 240                 /* stop looking after the last key */
 241                 if (ap->type == RIP_AUTH_NONE)
 242                         break;
 243
 244                 /* ignore keys that are not ready yet */
 245                 if ((u_long)ap->start > (u_long)clk.tv_sec)
 246                         continue;
 247
 248                 if ((u_long)ap->end < (u_long)clk.tv_sec) {
 249                         /* note best expired password as a fall-back */
 250                         if (res == 0 || (u_long)ap->end > (u_long)res->end)
 251                                 res = ap;
 252                         continue;
 253                 }
 254
 255                 /* note key with the best future */
 256                 if (res == 0 || (u_long)res->end < (u_long)ap->end)
 257                         res = ap;
 258         }
 259         return res;
 260 }
 261
 262
 263 void
 264 clr_ws_buf(struct ws_buf *wb,
 265            struct auth *ap)
 266 {
 267         struct netauth *na;
 268
 269         wb->lim = wb->base + NETS_LEN;
 270         wb->n = wb->base;
 271         memset(wb->n, 0, NETS_LEN*sizeof(*wb->n));
 272
 273         /* (start to) install authentication if appropriate
 274          */
 275         if (ap == 0)
 276                 return;
 277
 278         na = (struct netauth*)wb->n;
 279         if (ap->type == RIP_AUTH_PW) {
 280                 na->a_family = RIP_AF_AUTH;
 281                 na->a_type = RIP_AUTH_PW;
 282                 memcpy(na->au.au_pw, ap->key, sizeof(na->au.au_pw));
 283                 wb->n++;
 284
 285         } else if (ap->type ==  RIP_AUTH_MD5) {
 286                 na->a_family = RIP_AF_AUTH;
 287                 na->a_type = RIP_AUTH_MD5;
 288                 na->au.a_md5.md5_keyid = ap->keyid;
 289                 na->au.a_md5.md5_auth_len = RIP_AUTH_MD5_KEY_LEN;
 290                 na->au.a_md5.md5_seqno = htonl(clk.tv_sec);
 291                 wb->n++;
 292                 wb->lim--;              /* make room for trailer */
 293         }
 294 }
 295
 296
 297 void
 298 end_md5_auth(struct ws_buf *wb,
 299              struct auth *ap)
 300 {
 301         struct netauth *na, *na2;
 302         MD5_CTX md5_ctx;
 303         int len;
 304
 305
 306         na = (struct netauth*)wb->base;
 307         na2 = (struct netauth*)wb->n;
 308         len = (char *)na2-(char *)wb->buf;
 309         na2->a_family = RIP_AF_AUTH;
 310         na2->a_type = htons(1);
 311         na->au.a_md5.md5_pkt_len = htons(len);
 312         MD5Init(&md5_ctx);
 313         MD5Update(&md5_ctx, (u_char *)wb->buf, len + RIP_AUTH_MD5_HASH_XTRA);
 314         MD5Update(&md5_ctx, ap->key, RIP_AUTH_MD5_KEY_LEN);
 315         MD5Final(na2->au.au_pw, &md5_ctx);
 316         wb->n++;
 317 }
 318
 319
 320 /* Send the buffer
 321  */
 322 static void
 323 supply_write(struct ws_buf *wb)
 324 {
 325         /* Output multicast only if legal.
 326          * If we would multicast and it would be illegal, then discard the
 327          * packet.
 328          */
 329         switch (wb->type) {
 330         case NO_OUT_MULTICAST:
 331                 trace_pkt("skip multicast to %s because impossible",
 332                           naddr_ntoa(ws.to.sin_addr.s_addr));
 333                 break;
 334         case NO_OUT_RIPV2:
 335                 break;
 336         default:
 337                 if (ws.a != 0 && ws.a->type == RIP_AUTH_MD5)
 338                         end_md5_auth(wb,ws.a);
 339                 if (output(wb->type, &ws.to, ws.ifp, wb->buf,
 340                            ((char *)wb->n - (char*)wb->buf)) < 0
 341                     && ws.ifp != 0)
 342                         if_sick(ws.ifp);
 343                 ws.npackets++;
 344                 break;
 345         }
 346
 347         clr_ws_buf(wb,ws.a);
 348 }
 349
 350
 351 /* put an entry into the packet
 352  */
 353 static void
 354 supply_out(struct ag_info *ag)
 355 {
 356         int i;
 357         naddr mask, v1_mask, dst_h, ddst_h = 0;
 358         struct ws_buf *wb;
 359
 360
 361         /* Skip this route if doing a flash update and it and the routes
 362          * it aggregates have not changed recently.
 363          */
 364         if (ag->ag_seqno < update_seqno
 365             && (ws.state & WS_ST_FLASH))
 366                 return;
 367
 368         dst_h = ag->ag_dst_h;
 369         mask = ag->ag_mask;
 370         v1_mask = ripv1_mask_host(htonl(dst_h),
 371                                   (ws.state & WS_ST_TO_ON_NET) ? ws.ifp : 0);
 372         i = 0;
 373
 374         /* If we are sending RIPv2 packets that cannot (or must not) be
 375          * heard by RIPv1 listeners, do not worry about sub- or supernets.
 376          * Subnets (from other networks) can only be sent via multicast.
 377          * A pair of subnet routes might have been promoted so that they
 378          * are legal to send by RIPv1.
 379          * If RIPv1 is off, use the multicast buffer.
 380          */
 381         if ((ws.state & WS_ST_RIP2_ALL)
 382             || ((ag->ag_state & AGS_RIPV2) && v1_mask != mask)) {
 383                 /* use the RIPv2-only buffer */
 384                 wb = &v2buf;
 385
 386         } else {
 387                 /* use the RIPv1-or-RIPv2 buffer */
 388                 wb = &v12buf;
 389
 390                 /* Convert supernet route into corresponding set of network
 391                  * routes for RIPv1, but leave non-contiguous netmasks
 392                  * to ag_check().
 393                  */
 394                 if (v1_mask > mask
 395                     && mask + (mask & -mask) == 0) {
 396                         ddst_h = v1_mask & -v1_mask;
 397                         i = (v1_mask & ~mask)/ddst_h;
 398
 399                         if (i > ws.gen_limit) {
 400                                 /* Punt if we would have to generate an
 401                                  * unreasonable number of routes.
 402                                  */
 403                                 if (TRACECONTENTS)
 404                                         trace_misc("sending %s-->%s as 1"
 405                                                    " instead of %d routes",
 406                                                    addrname(htonl(dst_h), mask,
 407                                                         1),
 408                                                    naddr_ntoa(ws.to.sin_addr
 409                                                         .s_addr),
 410                                                    i+1);
 411                                 i = 0;
 412
 413                         } else {
 414                                 mask = v1_mask;
 415                                 ws.gen_limit -= i;
 416                         }
 417                 }
 418         }
 419
 420         do {
 421                 wb->n->n_family = RIP_AF_INET;
 422                 wb->n->n_dst = htonl(dst_h);
 423                 /* If the route is from router-discovery or we are
 424                  * shutting down, admit only a bad metric.
 425                  */
 426                 wb->n->n_metric = ((stopint || ag->ag_metric < 1)
 427                                    ? HOPCNT_INFINITY
 428                                    : ag->ag_metric);
 429                 HTONL(wb->n->n_metric);
 430                 /* Any non-zero bits in the supposedly unused RIPv1 fields
 431                  * cause the old `routed` to ignore the route.
 432                  * That means the mask and so forth cannot be sent
 433                  * in the hybrid RIPv1/RIPv2 mode.
 434                  */
 435                 if (ws.state & WS_ST_RIP2_ALL) {
 436                         if (ag->ag_nhop != 0
 437                             && ((ws.state & WS_ST_QUERY)
 438                                 || (ag->ag_nhop != ws.ifp->int_addr
 439                                     && on_net(ag->ag_nhop,
 440                                               ws.ifp->int_net,
 441                                               ws.ifp->int_mask))))
 442                                 wb->n->n_nhop = ag->ag_nhop;
 443                         wb->n->n_mask = htonl(mask);
 444                         wb->n->n_tag = ag->ag_tag;
 445                 }
 446                 dst_h += ddst_h;
 447
 448                 if (++wb->n >= wb->lim)
 449                         supply_write(wb);
 450         } while (i-- != 0);
 451 }
 452
 453
 454 /* supply one route from the table
 455  */
 456 /* ARGSUSED */
 457 static int
 458 walk_supply(struct radix_node *rn,
 459             struct walkarg *argp UNUSED)
 460 {
 461 #define RT ((struct rt_entry *)rn)
 462         u_short ags;
 463         char metric, pref;
 464         naddr dst, nhop;
 465         struct rt_spare *rts;
 466         int i;
 467
 468
 469         /* Do not advertise external remote interfaces or passive interfaces.
 470          */
 471         if ((RT->rt_state & RS_IF)
 472             && RT->rt_ifp != 0
 473             && (RT->rt_ifp->int_state & IS_PASSIVE)
 474             && !(RT->rt_state & RS_MHOME))
 475                 return 0;
 476
 477         /* If being quiet about our ability to forward, then
 478          * do not say anything unless responding to a query,
 479          * except about our main interface.
 480          */
 481         if (!supplier && !(ws.state & WS_ST_QUERY)
 482             && !(RT->rt_state & RS_MHOME))
 483                 return 0;
 484
 485         dst = RT->rt_dst;
 486
 487         /* do not collide with the fake default route */
 488         if (dst == RIP_DEFAULT
 489             && (ws.state & WS_ST_DEFAULT))
 490                 return 0;
 491
 492         if (RT->rt_state & RS_NET_SYN) {
 493                 if (RT->rt_state & RS_NET_INT) {
 494                         /* Do not send manual synthetic network routes
 495                          * into the subnet.
 496                          */
 497                         if (on_net(ws.to.sin_addr.s_addr,
 498                                    ntohl(dst), RT->rt_mask))
 499                                 return 0;
 500
 501                 } else {
 502                         /* Do not send automatic synthetic network routes
 503                          * if they are not needed because no RIPv1 listeners
 504                          * can hear them.
 505                          */
 506                         if (ws.state & WS_ST_RIP2_ALL)
 507                                 return 0;
 508
 509                         /* Do not send automatic synthetic network routes to
 510                          * the real subnet.
 511                          */
 512                         if (on_net(ws.to.sin_addr.s_addr,
 513                                    ntohl(dst), RT->rt_mask))
 514                                 return 0;
 515                 }
 516                 nhop = 0;
 517
 518         } else {
 519                 /* Advertise the next hop if this is not a route for one
 520                  * of our interfaces and the next hop is on the same
 521                  * network as the target.
 522                  * The final determination is made by supply_out().
 523                  */
 524                 if (!(RT->rt_state & RS_IF)
 525                     && RT->rt_gate != myaddr
 526                     && RT->rt_gate != loopaddr)
 527                         nhop = RT->rt_gate;
 528                 else
 529                         nhop = 0;
 530         }
 531
 532         metric = RT->rt_metric;
 533         ags = 0;
 534
 535         if (RT->rt_state & RS_MHOME) {
 536                 /* retain host route of multi-homed servers */
 537                 ;
 538
 539         } else if (RT_ISHOST(RT)) {
 540                 /* We should always suppress (into existing network routes)
 541                  * the host routes for the local end of our point-to-point
 542                  * links.
 543                  * If we are suppressing host routes in general, then do so.
 544                  * Avoid advertising host routes onto their own network,
 545                  * where they should be handled by proxy-ARP.
 546                  */
 547                 if ((RT->rt_state & RS_LOCAL)
 548                     || ridhosts
 549                     || on_net(dst, ws.to_net, ws.to_mask))
 550                         ags |= AGS_SUPPRESS;
 551
 552                 /* Aggregate stray host routes into network routes if allowed.
 553                  * We cannot aggregate host routes into small network routes
 554                  * without confusing RIPv1 listeners into thinking the
 555                  * network routes are host routes.
 556                  */
 557                 if ((ws.state & WS_ST_AG) && (ws.state & WS_ST_RIP2_ALL))
 558                         ags |= AGS_AGGREGATE;
 559
 560         } else {
 561                 /* Always suppress network routes into other, existing
 562                  * network routes
 563                  */
 564                 ags |= AGS_SUPPRESS;
 565
 566                 /* Generate supernets if allowed.
 567                  * If we can be heard by RIPv1 systems, we will
 568                  * later convert back to ordinary nets.
 569                  * This unifies dealing with received supernets.
 570                  */
 571                 if ((ws.state & WS_ST_AG)
 572                     && ((RT->rt_state & RS_SUBNET)
 573                         || (ws.state & WS_ST_SUPER_AG)))
 574                         ags |= AGS_AGGREGATE;
 575         }
 576
 577         /* Do not send RIPv1 advertisements of subnets to other
 578          * networks. If possible, multicast them by RIPv2.
 579          */
 580         if ((RT->rt_state & RS_SUBNET)
 581             && !(ws.state & WS_ST_RIP2_ALL)
 582             && !on_net(dst, ws.to_std_net, ws.to_std_mask))
 583                 ags |= AGS_RIPV2 | AGS_AGGREGATE;
 584
 585
 586         /* Do not send a route back to where it came from, except in
 587          * response to a query.  This is "split-horizon".  That means not
 588          * advertising back to the same network and so via the same interface.
 589          *
 590          * We want to suppress routes that might have been fragmented
 591          * from this route by a RIPv1 router and sent back to us, and so we
 592          * cannot forget this route here.  Let the split-horizon route
 593          * suppress the fragmented routes and then itself be forgotten.
 594          *
 595          * Include the routes for both ends of point-to-point interfaces
 596          * among those suppressed by split-horizon, since the other side
 597          * should knows them as well as we do.
 598          *
 599          * Notice spare routes with the same metric that we are about to
 600          * advertise, to split the horizon on redundant, inactive paths.
 601          *
 602          * Do not suppress advertisements of interface-related addresses on
 603          * non-point-to-point interfaces.  This ensures that we have something
 604          * to say every 30 seconds to help detect broken Ethernets or
 605          * other interfaces where one packet every 30 seconds costs nothing.
 606          */
 607         if (ws.ifp != 0
 608             && !(ws.state & WS_ST_QUERY)
 609             && (ws.state & WS_ST_TO_ON_NET)
 610             && (!(RT->rt_state & RS_IF)
 611                 || ws.ifp->int_if_flags & IFF_POINTOPOINT)) {
 612                 for (rts = RT->rt_spares, i = NUM_SPARES; i != 0; i--, rts++) {
 613                         if (rts->rts_metric > metric
 614                             || rts->rts_ifp != ws.ifp)
 615                                 continue;
 616
 617                         /* If we do not mark the route with AGS_SPLIT_HZ here,
 618                          * it will be poisoned-reverse, or advertised back
 619                          * toward its source with an infinite metric.
 620                          * If we have recently advertised the route with a
 621                          * better metric than we now have, then we should
 622                          * poison-reverse the route before suppressing it for
 623                          * split-horizon.
 624                          *
 625                          * In almost all cases, if there is no spare for the
 626                          * route then it is either old and dead or a brand
 627                          * new route. If it is brand new, there is no need
 628                          * for poison-reverse. If it is old and dead, it
 629                          * is already poisoned.
 630                          */
 631                         if (RT->rt_poison_time < now_expire
 632                             || RT->rt_poison_metric >= metric
 633                             || RT->rt_spares[1].rts_gate == 0) {
 634                                 ags |= AGS_SPLIT_HZ;
 635                                 ags &= ~AGS_SUPPRESS;
 636                         }
 637                         metric = HOPCNT_INFINITY;
 638                         break;
 639                 }
 640         }
 641
 642         /* Keep track of the best metric with which the
 643          * route has been advertised recently.
 644          */
 645         if (RT->rt_poison_metric >= metric
 646             || RT->rt_poison_time < now_expire) {
 647                 RT->rt_poison_time = now.tv_sec;
 648                 RT->rt_poison_metric = metric;
 649         }
 650
 651         /* Adjust the outgoing metric by the cost of the link.
 652          * Avoid aggregation when a route is counting to infinity.
 653          */
 654         pref = RT->rt_poison_metric + ws.metric;
 655         metric += ws.metric;
 656
 657         /* Do not advertise stable routes that will be ignored,
 658          * unless we are answering a query.
 659          * If the route recently was advertised with a metric that
 660          * would have been less than infinity through this interface,
 661          * we need to continue to advertise it in order to poison it.
 662          */
 663         if (metric >= HOPCNT_INFINITY) {
 664                 if (!(ws.state & WS_ST_QUERY)
 665                     && (pref >= HOPCNT_INFINITY
 666                         || RT->rt_poison_time < now_garbage))
 667                         return 0;
 668
 669                 metric = HOPCNT_INFINITY;
 670         }
 671
 672         ag_check(dst, RT->rt_mask, 0, nhop, metric, pref,
 673                  RT->rt_seqno, RT->rt_tag, ags, supply_out);
 674         return 0;
 675 #undef RT
 676 }
 677
 678
 679 /* Supply dst with the contents of the routing tables.
 680  * If this won't fit in one packet, chop it up into several.
 681  */
 682 void
 683 supply(struct sockaddr_in *dst,
 684        struct interface *ifp,           /* output interface */
 685        enum output_type type,
 686        int flash,                       /* 1=flash update */
 687        int vers,                        /* RIP version */
 688        int passwd_ok)                   /* OK to include cleartext password */
 689 {
 690         struct rt_entry *rt;
 691         int def_metric;
 692
 693
 694         ws.state = 0;
 695         ws.gen_limit = 1024;
 696
 697         ws.to = *dst;
 698         ws.to_std_mask = std_mask(ws.to.sin_addr.s_addr);
 699         ws.to_std_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_std_mask;
 700
 701         if (ifp != 0) {
 702                 ws.to_mask = ifp->int_mask;
 703                 ws.to_net = ifp->int_net;
 704                 if (on_net(ws.to.sin_addr.s_addr, ws.to_net, ws.to_mask))
 705                         ws.state |= WS_ST_TO_ON_NET;
 706
 707         } else {
 708                 ws.to_mask = ripv1_mask_net(ws.to.sin_addr.s_addr, 0);
 709                 ws.to_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_mask;
 710                 rt = rtfind(dst->sin_addr.s_addr);
 711                 if (rt)
 712                         ifp = rt->rt_ifp;
 713         }
 714
 715         ws.npackets = 0;
 716         if (flash)
 717                 ws.state |= WS_ST_FLASH;
 718
 719         if ((ws.ifp = ifp) == 0) {
 720                 ws.metric = 1;
 721         } else {
 722                 /* Adjust the advertised metric by the outgoing interface
 723                  * metric.
 724                  */
 725                 ws.metric = ifp->int_metric + 1 + ifp->int_adj_outmetric;
 726         }
 727
 728         ripv12_buf.rip.rip_vers = vers;
 729
 730         switch (type) {
 731         case OUT_MULTICAST:
 732                 if (ifp != NULL && ifp->int_if_flags & IFF_MULTICAST)
 733                         v2buf.type = OUT_MULTICAST;
 734                 else
 735                         v2buf.type = NO_OUT_MULTICAST;
 736                 v12buf.type = OUT_BROADCAST;
 737                 break;
 738
 739         case OUT_QUERY:
 740                 ws.state |= WS_ST_QUERY;
 741                 /* fall through */
 742         case OUT_BROADCAST:
 743         case OUT_UNICAST:
 744                 v2buf.type = (vers == RIPv2) ? type : NO_OUT_RIPV2;
 745                 v12buf.type = type;
 746                 break;
 747
 748         case NO_OUT_MULTICAST:
 749         case NO_OUT_RIPV2:
 750                 break;                  /* no output */
 751         }
 752
 753         if (vers == RIPv2) {
 754                 /* full RIPv2 only if cannot be heard by RIPv1 listeners */
 755                 if (type != OUT_BROADCAST)
 756                         ws.state |= WS_ST_RIP2_ALL;
 757                 if ((ws.state & WS_ST_QUERY)
 758                     || !(ws.state & WS_ST_TO_ON_NET)) {
 759                         ws.state |= (WS_ST_AG | WS_ST_SUPER_AG);
 760                 } else if (ifp == 0 || !(ifp->int_state & IS_NO_AG)) {
 761                         ws.state |= WS_ST_AG;
 762                         if (type != OUT_BROADCAST
 763                             && (ifp == 0
 764                                 || !(ifp->int_state & IS_NO_SUPER_AG)))
 765                                 ws.state |= WS_ST_SUPER_AG;
 766                 }
 767         }
 768
 769         ws.a = (vers == RIPv2) ? find_auth(ifp) : 0;
 770         if (!passwd_ok && ws.a != 0 && ws.a->type == RIP_AUTH_PW)
 771                 ws.a = 0;
 772         clr_ws_buf(&v12buf,ws.a);
 773         clr_ws_buf(&v2buf,ws.a);
 774
 775         /*  Fake a default route if asked and if there is not already
 776          * a better, real default route.
 777          */
 778         if (supplier && ifp && (def_metric = ifp->int_d_metric) != 0) {
 779                 if (0 == (rt = rtget(RIP_DEFAULT, 0))
 780                     || rt->rt_metric+ws.metric >= def_metric) {
 781                         ws.state |= WS_ST_DEFAULT;
 782                         ag_check(0, 0, 0, 0, def_metric, def_metric,
 783                                  0, 0, 0, supply_out);
 784                 } else {
 785                         def_metric = rt->rt_metric+ws.metric;
 786                 }
 787
 788                 /* If both RIPv2 and the poor-man's router discovery
 789                  * kludge are on, arrange to advertise an extra
 790                  * default route via RIPv1.
 791                  */
 792                 if ((ws.state & WS_ST_RIP2_ALL)
 793                     && (ifp->int_state & IS_PM_RDISC)) {
 794                         ripv12_buf.rip.rip_vers = RIPv1;
 795                         v12buf.n->n_family = RIP_AF_INET;
 796                         v12buf.n->n_dst = htonl(RIP_DEFAULT);
 797                         v12buf.n->n_metric = htonl(def_metric);
 798                         v12buf.n++;
 799                 }
 800         }
 801
 802         (void)rn_walktree(rhead, walk_supply, 0);
 803         ag_flush(0,0,supply_out);
 804
 805         /* Flush the packet buffers, provided they are not empty and
 806          * do not contain only the password.
 807          */
 808         if (v12buf.n != v12buf.base
 809             && (v12buf.n > v12buf.base+1
 810                 || v12buf.base->n_family != RIP_AF_AUTH))
 811                 supply_write(&v12buf);
 812         if (v2buf.n != v2buf.base
 813             && (v2buf.n > v2buf.base+1
 814                 || v2buf.base->n_family != RIP_AF_AUTH))
 815                 supply_write(&v2buf);
 816
 817         /* If we sent nothing and this is an answer to a query, send
 818          * an empty buffer.
 819          */
 820         if (ws.npackets == 0
 821             && (ws.state & WS_ST_QUERY))
 822                 supply_write(&v12buf);
 823 }
 824
 825
 826 /* send all of the routing table or just do a flash update
 827  */
 828 void
 829 rip_bcast(int flash)
 830 {
 831 #ifdef _HAVE_SIN_LEN
 832         static struct sockaddr_in dst = {sizeof(dst), AF_INET, 0, {0}, {0}};
 833 #else
 834         static struct sockaddr_in dst = {AF_INET};
 835 #endif
 836         struct interface *ifp;
 837         enum output_type type;
 838         int vers;
 839         struct timeval rtime;
 840
 841
 842         need_flash = 0;
 843         intvl_random(&rtime, MIN_WAITTIME, MAX_WAITTIME);
 844         no_flash = rtime;
 845         timevaladd(&no_flash, &now);
 846
 847         if (rip_sock < 0)
 848                 return;
 849
 850         trace_act("send %s and inhibit dynamic updates for %.3f sec",
 851                   flash ? "dynamic update" : "all routes",
 852                   rtime.tv_sec + ((float)rtime.tv_usec)/1000000.0);
 853
 854         for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) {
 855                 /* Skip interfaces not doing RIP.
 856                  * Do try broken interfaces to see if they have healed.
 857                  */
 858                 if (IS_RIP_OUT_OFF(ifp->int_state))
 859                         continue;
 860
 861                 /* skip turned off interfaces */
 862                 if (!iff_up(ifp->int_if_flags))
 863                         continue;
 864
 865                 vers = (ifp->int_state & IS_NO_RIPV1_OUT) ? RIPv2 : RIPv1;
 866
 867                 if (ifp->int_if_flags & IFF_BROADCAST) {
 868                         /* ordinary, hardware interface */
 869                         dst.sin_addr.s_addr = ifp->int_brdaddr;
 870
 871                         if (vers == RIPv2
 872                             && !(ifp->int_state  & IS_NO_RIP_MCAST)) {
 873                                 type = OUT_MULTICAST;
 874                         } else {
 875                                 type = OUT_BROADCAST;
 876                         }
 877
 878                 } else if (ifp->int_if_flags & IFF_POINTOPOINT) {
 879                         /* point-to-point hardware interface */
 880                         dst.sin_addr.s_addr = ifp->int_dstaddr;
 881                         type = OUT_UNICAST;
 882
 883                 } else if (ifp->int_state & IS_REMOTE) {
 884                         /* remote interface */
 885                         dst.sin_addr.s_addr = ifp->int_addr;
 886                         type = OUT_UNICAST;
 887
 888                 } else {
 889                         /* ATM, HIPPI, etc. */
 890                         continue;
 891                 }
 892
 893                 supply(&dst, ifp, type, flash, vers, 1);
 894         }
 895
 896         update_seqno++;                 /* all routes are up to date */
 897 }
 898
 899
 900 /* Ask for routes
 901  * Do it only once to an interface, and not even after the interface
 902  * was broken and recovered.
 903  */
 904 void
 905 rip_query(void)
 906 {
 907 #ifdef _HAVE_SIN_LEN
 908         static struct sockaddr_in dst = {sizeof(dst), AF_INET, 0, {0}, {0}};
 909 #else
 910         static struct sockaddr_in dst = {AF_INET};
 911 #endif
 912         struct interface *ifp;
 913         struct rip buf;
 914         enum output_type type;
 915
 916
 917         if (rip_sock < 0)
 918                 return;
 919
 920         memset(&buf, 0, sizeof(buf));
 921
 922         for (ifp = ifnet; ifp; ifp = ifp->int_next) {
 923                 /* Skip interfaces those already queried.
 924                  * Do not ask via interfaces through which we don't
 925                  * accept input.  Do not ask via interfaces that cannot
 926                  * send RIP packets.
 927                  * Do try broken interfaces to see if they have healed.
 928                  */
 929                 if (IS_RIP_IN_OFF(ifp->int_state)
 930                     || ifp->int_query_time != NEVER)
 931                         continue;
 932
 933                 /* skip turned off interfaces */
 934                 if (!iff_up(ifp->int_if_flags))
 935                         continue;
 936
 937                 buf.rip_vers = (ifp->int_state&IS_NO_RIPV1_OUT) ? RIPv2:RIPv1;
 938                 buf.rip_cmd = RIPCMD_REQUEST;
 939                 buf.rip_nets[0].n_family = RIP_AF_UNSPEC;
 940                 buf.rip_nets[0].n_metric = htonl(HOPCNT_INFINITY);
 941
 942                 /* Send a RIPv1 query only if allowed and if we will
 943                  * listen to RIPv1 routers.
 944                  */
 945                 if ((ifp->int_state & IS_NO_RIPV1_OUT)
 946                     || (ifp->int_state & IS_NO_RIPV1_IN)) {
 947                         buf.rip_vers = RIPv2;
 948                 } else {
 949                         buf.rip_vers = RIPv1;
 950                 }
 951
 952                 if (ifp->int_if_flags & IFF_BROADCAST) {
 953                         /* ordinary, hardware interface */
 954                         dst.sin_addr.s_addr = ifp->int_brdaddr;
 955
 956                         /* Broadcast RIPv1 queries and RIPv2 queries
 957                          * when the hardware cannot multicast.
 958                          */
 959                         if (buf.rip_vers == RIPv2
 960                             && (ifp->int_if_flags & IFF_MULTICAST)
 961                             && !(ifp->int_state  & IS_NO_RIP_MCAST)) {
 962                                 type = OUT_MULTICAST;
 963                         } else {
 964                                 type = OUT_BROADCAST;
 965                         }
 966
 967                 } else if (ifp->int_if_flags & IFF_POINTOPOINT) {
 968                         /* point-to-point hardware interface */
 969                         dst.sin_addr.s_addr = ifp->int_dstaddr;
 970                         type = OUT_UNICAST;
 971
 972                 } else if (ifp->int_state & IS_REMOTE) {
 973                         /* remote interface */
 974                         dst.sin_addr.s_addr = ifp->int_addr;
 975                         type = OUT_UNICAST;
 976
 977                 } else {
 978                         /* ATM, HIPPI, etc. */
 979                         continue;
 980                 }
 981
 982                 ifp->int_query_time = now.tv_sec+SUPPLY_INTERVAL;
 983                 if (output(type, &dst, ifp, &buf, sizeof(buf)) < 0)
 984                         if_sick(ifp);
 985         }
 986 }