usr/src/cmd/cmd-inet/usr.sbin/in.routed/output.c

   1 /*
   2  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
   3  * Use is subject to license terms.
   4  *
   5  * Copyright (c) 1983, 1988, 1993
   6  *      The Regents of the University of California.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgment:
  18  *      This product includes software developed by the University of
  19  *      California, Berkeley and its contributors.
  20  * 4. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  *
  36  * $FreeBSD: src/sbin/routed/output.c,v 1.7 2000/08/11 08:24:38 sheldonh Exp $
  37  */
  38
  39 #pragma ident   "%Z%%M% %I%     %E% SMI"
  40
  41 #include "defs.h"
  42 #include <md5.h>
  43 #include <alloca.h>
  44
  45 uint_t update_seqno;
  46
  47
  48 /*
  49  * walk the tree of routes with this for output
  50  */
  51 static  struct {
  52         struct sockaddr_in to;
  53         in_addr_t       to_mask;
  54         in_addr_t       to_net;
  55         in_addr_t       to_std_mask;
  56         in_addr_t       to_std_net;
  57         struct interface *ifp;          /* usually output interface */
  58         struct auth     *a;
  59         uint8_t         metric;         /* adjust metrics by interface */
  60         uint32_t        npackets;
  61         uint32_t        gen_limit;
  62 #define WS_GEN_LIMIT_MAX        1024
  63         uint16_t        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 static  union pkt_buf ripv12_buf;
  76
  77 /* Another for only RIPv2 listeners */
  78 static  struct ws_buf v2buf;
  79 static  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 /*
  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 sin;
 108         int flags;
 109         const char *msg;
 110         int res;
 111         int ifindex;
 112         struct in_addr addr;
 113
 114         sin = *dst;
 115         if (sin.sin_port == 0)
 116                 sin.sin_port = htons(RIP_PORT);
 117
 118         flags = 0;
 119
 120         if (ifp == NULL && type == OUT_MULTICAST) {
 121                 msglog("Cannot send RIP message to %s",
 122                     inet_ntoa(sin.sin_addr));
 123                 return (-1);
 124         }
 125
 126         switch (type) {
 127         case OUT_QUERY:
 128                 msg = "Answer Query";
 129                 break;
 130         case OUT_UNICAST:
 131                 msg = "Send";
 132                 flags = MSG_DONTROUTE;
 133                 break;
 134         case OUT_BROADCAST:
 135                 msg = "Send bcast";
 136                 break;
 137         case OUT_MULTICAST:
 138                 msg = "Send mcast";
 139                 break;
 140
 141         case NO_OUT_MULTICAST:
 142         case NO_OUT_RIPV2:
 143         default:
 144 #ifdef DEBUG
 145                 abort();
 146 #endif
 147                 return (-1);
 148         }
 149
 150         /*
 151          * IP_PKTINFO overrides IP_MULTICAST_IF, so we don't set ifindex
 152          * for multicast traffic.
 153          */
 154         ifindex = (type != OUT_MULTICAST && type != OUT_QUERY &&
 155             ifp != NULL && ifp->int_phys != NULL) ?
 156             ifp->int_phys->phyi_index : 0;
 157
 158         if (rip_sock_interface != ifp) {
 159                 /*
 160                  * For multicast, we have to choose the source
 161                  * address.  This is either the local address
 162                  * (non-point-to-point) or the remote address.
 163                  */
 164                 if (ifp != NULL) {
 165                         addr.s_addr = (ifp->int_if_flags & IFF_POINTOPOINT) ?
 166                             ifp->int_dstaddr : ifp->int_addr;
 167                         if (type == OUT_MULTICAST &&
 168                             setsockopt(rip_sock, IPPROTO_IP,
 169                             IP_MULTICAST_IF, &addr, sizeof (addr)) == -1) {
 170                                 LOGERR("setsockopt(rip_sock, IP_MULTICAST_IF)");
 171                                 return (-1);
 172                         }
 173                 }
 174                 rip_sock_interface = ifp;
 175         }
 176
 177         trace_rip(msg, "to", &sin, ifp, buf, size);
 178
 179         res = sendtoif(rip_sock, buf, size, flags, &sin, ifindex);
 180         if (res < 0 && (ifp == NULL || !(ifp->int_state & IS_BROKE))) {
 181                 writelog(LOG_WARNING, "%s sendto(%s%s%s.%d): %s", msg,
 182                     ifp != NULL ? ifp->int_name : "",
 183                     ifp != NULL ? ", " : "",
 184                     inet_ntoa(sin.sin_addr),
 185                     ntohs(sin.sin_port),
 186                     rip_strerror(errno));
 187         }
 188
 189         return (res);
 190 }
 191
 192 /*
 193  * Semantically identical to sendto(), but sends the message through a
 194  * specific interface (if ifindex is non-zero) using IP_PKTINFO.
 195  */
 196 int
 197 sendtoif(int fd, const void *buf, uint_t bufsize, uint_t flags,
 198     struct sockaddr_in *sinp, uint_t ifindex)
 199 {
 200         struct iovec iov;
 201         struct msghdr msg;
 202         struct cmsghdr *cmsgp;
 203         struct in_pktinfo *ipip;
 204
 205         iov.iov_base = (void *)buf;
 206         iov.iov_len = bufsize;
 207
 208         (void) memset(&msg, 0, sizeof (struct msghdr));
 209         msg.msg_name = (struct sockaddr *)sinp;
 210         msg.msg_namelen = sizeof (struct sockaddr_in);
 211         msg.msg_iov = &iov;
 212         msg.msg_iovlen = 1;
 213
 214         if (ifindex != 0) {
 215                 /*
 216                  * We can't precisely predict the alignment padding we'll
 217                  * need, so we allocate the maximum alignment and then
 218                  * use CMSG_NXTHDR() to fix it up at the end.
 219                  */
 220                 msg.msg_controllen = sizeof (*cmsgp) + _MAX_ALIGNMENT +
 221                     sizeof (*ipip) + _MAX_ALIGNMENT + sizeof (*cmsgp);
 222                 msg.msg_control = alloca(msg.msg_controllen);
 223
 224                 cmsgp = CMSG_FIRSTHDR(&msg);
 225                 ipip = (void *)CMSG_DATA(cmsgp);
 226                 (void) memset(ipip, 0, sizeof (struct in_pktinfo));
 227                 ipip->ipi_ifindex = ifindex;
 228                 cmsgp->cmsg_len = (caddr_t)(ipip + 1) - (caddr_t)cmsgp;
 229                 cmsgp->cmsg_type = IP_PKTINFO;
 230                 cmsgp->cmsg_level = IPPROTO_IP;
 231
 232                 /*
 233                  * Correct the control message length.
 234                  */
 235                 cmsgp = CMSG_NXTHDR(&msg, cmsgp);
 236                 msg.msg_controllen = (caddr_t)cmsgp - (caddr_t)msg.msg_control;
 237         }
 238
 239         return (sendmsg(fd, &msg, flags));
 240 }
 241
 242 /*
 243  * Find the first key for a packet to send.
 244  * Try for a key that is eligible and has not expired, but settle for
 245  * the last key if they have all expired.
 246  * If no key is ready yet, give up.
 247  */
 248 struct auth *
 249 find_auth(struct interface *ifp)
 250 {
 251         struct auth *ap, *res = NULL;
 252         int i;
 253
 254
 255         if (ifp == NULL)
 256                 return (NULL);
 257
 258         if ((ap = ifp->int_auth) == NULL)
 259                 return (NULL);
 260
 261         for (i = 0; i < MAX_AUTH_KEYS; i++, ap++) {
 262                 /* stop looking after the last key */
 263                 if (ap->type == RIP_AUTH_NONE)
 264                         break;
 265
 266                 /* ignore keys that are not ready yet */
 267                 if ((ulong_t)ap->start > (ulong_t)clk.tv_sec)
 268                         continue;
 269
 270                 if ((ulong_t)ap->end < (ulong_t)clk.tv_sec) {
 271                         /* note best expired password as a fall-back */
 272                         if (res == NULL ||
 273                             (((ulong_t)ap->end > (ulong_t)res->end)) &&
 274                             ((ulong_t)res->end < (ulong_t)clk.tv_sec))
 275                                 res = ap;
 276                         continue;
 277                 }
 278
 279                 /* note key with the best future */
 280                 if (res == NULL || (ulong_t)res->end < (ulong_t)ap->end)
 281                         res = ap;
 282         }
 283         return (res);
 284 }
 285
 286
 287 void
 288 clr_ws_buf(struct ws_buf *wb, struct auth *ap)
 289 {
 290         struct netauth *na;
 291
 292         wb->lim = wb->base + NETS_LEN;
 293         wb->n = wb->base;
 294         (void) memset(wb->n, 0, NETS_LEN*sizeof (*wb->n));
 295
 296         /*
 297          * (start to) install authentication if appropriate
 298          */
 299         if (ap == NULL)
 300                 return;
 301
 302         na = (struct netauth *)wb->n;
 303         if (ap->type == RIP_AUTH_PW) {
 304                 na->a_family = RIP_AF_AUTH;
 305                 na->a_type = RIP_AUTH_PW;
 306                 (void) memcpy(na->au.au_pw, ap->key, sizeof (na->au.au_pw));
 307                 wb->n++;
 308
 309         } else if (ap->type ==  RIP_AUTH_MD5) {
 310                 na->a_family = RIP_AF_AUTH;
 311                 na->a_type = RIP_AUTH_MD5;
 312                 na->au.a_md5.md5_keyid = ap->keyid;
 313                 na->au.a_md5.md5_auth_len = RIP_AUTH_MD5_LEN;
 314                 na->au.a_md5.md5_seqno = htonl(clk.tv_sec);
 315                 wb->n++;
 316                 wb->lim--;              /* make room for trailer */
 317         }
 318 }
 319
 320
 321 void
 322 end_md5_auth(struct ws_buf *wb, struct auth *ap)
 323 {
 324         struct netauth *na, *na2;
 325         MD5_CTX md5_ctx;
 326         int len;
 327
 328         na = (struct netauth *)wb->base;
 329         na2 = (struct netauth *)wb->n;
 330         len = (char *)na2-(char *)wb->buf;
 331         na2->a_family = RIP_AF_AUTH;
 332         na2->a_type = RIP_AUTH_TRAILER;
 333         na->au.a_md5.md5_pkt_len = htons(len);
 334         MD5Init(&md5_ctx);
 335         /* len+4 to include auth trailer's family/type in MD5 sum */
 336         MD5Update(&md5_ctx, (uchar_t *)wb->buf, len + 4);
 337         MD5Update(&md5_ctx, ap->key, RIP_AUTH_MD5_LEN);
 338         MD5Final(na2->au.au_pw, &md5_ctx);
 339         wb->n++;
 340 }
 341
 342
 343 /*
 344  * Send the buffer
 345  */
 346 static void
 347 supply_write(struct ws_buf *wb)
 348 {
 349         /*
 350          * Output multicast only if legal.
 351          * If we would multicast and it would be illegal, then discard the
 352          * packet.
 353          */
 354         switch (wb->type) {
 355         case NO_OUT_MULTICAST:
 356                 trace_pkt("skip multicast to %s because impossible",
 357                     naddr_ntoa(ws.to.sin_addr.s_addr));
 358                 break;
 359         case NO_OUT_RIPV2:
 360                 break;
 361         default:
 362                 if (ws.a != NULL && ws.a->type == RIP_AUTH_MD5)
 363                         end_md5_auth(wb, ws.a);
 364                 if (output(wb->type, &ws.to, ws.ifp, wb->buf,
 365                     ((char *)wb->n - (char *)wb->buf)) < 0 && ws.ifp != NULL)
 366                         if_sick(ws.ifp, _B_FALSE);
 367                 ws.npackets++;
 368                 break;
 369         }
 370
 371         clr_ws_buf(wb, ws.a);
 372 }
 373
 374
 375 /*
 376  * Put an entry into the packet
 377  */
 378 static void
 379 supply_out(struct ag_info *ag)
 380 {
 381         uint32_t dstcount;
 382         in_addr_t mask, v1_mask, dst_h, ddst_h = 0;
 383         struct ws_buf *wb;
 384
 385
 386         /*
 387          * Skip this route if doing a flash update and it and the routes
 388          * it aggregates have not changed recently.
 389          */
 390         if (ag->ag_seqno < update_seqno && (ws.state & WS_ST_FLASH))
 391                 return;
 392
 393         dst_h = ag->ag_dst_h;
 394         mask = ag->ag_mask;
 395         v1_mask = ripv1_mask_host(htonl(dst_h),
 396             (ws.state & WS_ST_TO_ON_NET) ? ws.ifp : NULL);
 397         dstcount = 0;
 398
 399         /*
 400          * If we are sending RIPv2 packets that cannot (or must not) be
 401          * heard by RIPv1 listeners, do not worry about sub- or supernets.
 402          * Subnets (from other networks) can only be sent via multicast.
 403          * A pair of subnet routes might have been promoted so that they
 404          * are legal to send by RIPv1.
 405          * If RIPv1 is off, use the multicast buffer.
 406          */
 407         if ((ws.state & WS_ST_RIP2_ALL) ||
 408             ((ag->ag_state & AGS_RIPV2) && v1_mask != mask)) {
 409                 /* use the RIPv2-only buffer */
 410                 wb = &v2buf;
 411
 412         } else {
 413                 /*
 414                  * use the RIPv1-or-RIPv2 buffer
 415                  */
 416                 wb = &v12buf;
 417
 418                 /*
 419                  * Convert supernet route into corresponding set of network
 420                  * routes for RIPv1, but leave non-contiguous netmasks
 421                  * to ag_check().
 422                  */
 423                 if (v1_mask > mask &&
 424                     mask + (mask & -mask) == 0) {
 425                         ddst_h = v1_mask & -v1_mask;
 426                         dstcount = (v1_mask & ~mask)/ddst_h;
 427
 428                         if (dstcount > ws.gen_limit) {
 429                                 /*
 430                                  * Punt if we would have to generate an
 431                                  * unreasonable number of routes.
 432                                  */
 433                                 if (TRACECONTENTS)
 434                                         trace_misc("sending %s-->%s as 1"
 435                                             " instead of %d routes",
 436                                             addrname(htonl(dst_h), mask, 1),
 437                                             naddr_ntoa(ws.to.sin_addr.s_addr),
 438                                             dstcount + 1);
 439                                 dstcount = 0;
 440
 441                         } else {
 442                                 mask = v1_mask;
 443                                 ws.gen_limit -= dstcount;
 444                         }
 445                 }
 446         }
 447
 448         do {
 449                 wb->n->n_family = RIP_AF_INET;
 450                 wb->n->n_dst = htonl(dst_h);
 451                 /*
 452                  * If the route is from router-discovery or we are
 453                  * shutting down, or this is a broken/sick interface,
 454                  * admit only a bad metric.
 455                  */
 456                 wb->n->n_metric = ((stopint || ag->ag_metric < 1 ||
 457                     (ag->ag_ifp && (ag->ag_ifp->int_state &
 458                     (IS_BROKE|IS_SICK)))) ? HOPCNT_INFINITY : ag->ag_metric);
 459                 wb->n->n_metric = htonl(wb->n->n_metric);
 460                 /*
 461                  * Any non-zero bits in the supposedly unused RIPv1 fields
 462                  * cause the old `routed` to ignore the route.
 463                  * That means the mask and so forth cannot be sent
 464                  * in the hybrid RIPv1/RIPv2 mode.
 465                  */
 466                 if (ws.state & WS_ST_RIP2_ALL) {
 467                         if (ag->ag_nhop != 0 &&
 468                             ((ws.state & WS_ST_QUERY) ||
 469                             (ag->ag_nhop != ws.ifp->int_addr &&
 470                             on_net(ag->ag_nhop, ws.ifp->int_net,
 471                             ws.ifp->int_mask)) &&
 472                             ifwithaddr(ag->ag_nhop, _B_FALSE, _B_FALSE) ==
 473                             NULL))
 474                                 wb->n->n_nhop = ag->ag_nhop;
 475                         wb->n->n_mask = htonl(mask);
 476                         wb->n->n_tag = ag->ag_tag;
 477                 }
 478                 dst_h += ddst_h;
 479
 480                 if (++wb->n >= wb->lim)
 481                         supply_write(wb);
 482         } while (dstcount-- > 0);
 483 }
 484
 485
 486 /*
 487  * Supply one route from the table
 488  */
 489 /* ARGSUSED */
 490 static int
 491 walk_supply(struct radix_node *rn, void *argp)
 492 {
 493 #define RT ((struct rt_entry *)rn)
 494         ushort_t ags;
 495         uint8_t metric, pref;
 496         in_addr_t dst, nhop;
 497         struct rt_spare *rts;
 498         uint_t sparecount;
 499
 500
 501         /*
 502          * Do not advertise external remote interfaces or passive interfaces.
 503          */
 504         if ((RT->rt_state & RS_IF) && RT->rt_ifp != NULL &&
 505             (RT->rt_ifp->int_state & IS_PASSIVE) &&
 506             !(RT->rt_state & RS_MHOME))
 507                 return (0);
 508         /*
 509          * Do not advertise routes learnt from /etc/gateways.
 510          */
 511         if (RT->rt_spares[0].rts_origin == RO_FILE)
 512                 return (0);
 513
 514         /*
 515          * Do not advertise routes which would lead to forwarding on a
 516          * non-forwarding interface.
 517          */
 518         if (RT->rt_state & RS_NOPROPAGATE)
 519                 return (0);
 520
 521         /*
 522          * If being quiet about our ability to forward, then
 523          * do not say anything unless responding to a query,
 524          * except about our main interface.
 525          */
 526         if (!should_supply(NULL) && !(ws.state & WS_ST_QUERY) &&
 527             !(RT->rt_state & RS_MHOME))
 528                 return (0);
 529
 530         dst = RT->rt_dst;
 531
 532         /*
 533          * do not collide with the fake default route
 534          */
 535         if (dst == RIP_DEFAULT && (ws.state & WS_ST_DEFAULT))
 536                 return (0);
 537
 538         if (RT->rt_state & RS_NET_SYN) {
 539                 if (RT->rt_state & RS_NET_INT) {
 540                         /*
 541                          * Do not send manual synthetic network routes
 542                          * into the subnet.
 543                          */
 544                         if (on_net(ws.to.sin_addr.s_addr,
 545                             ntohl(dst), RT->rt_mask))
 546                                 return (0);
 547
 548                 } else {
 549                         /*
 550                          * Do not send automatic synthetic network routes
 551                          * if they are not needed because no RIPv1 listeners
 552                          * can hear them.
 553                          */
 554                         if (ws.state & WS_ST_RIP2_ALL)
 555                                 return (0);
 556
 557                         /*
 558                          * Do not send automatic synthetic network routes to
 559                          * the real subnet.
 560                          */
 561                         if (on_net(ws.to.sin_addr.s_addr,
 562                             ntohl(dst), RT->rt_mask))
 563                                 return (0);
 564                 }
 565                 nhop = 0;
 566
 567         } else {
 568                 /*
 569                  * Advertise the next hop if this is not a route for one
 570                  * of our interfaces and the next hop is on the same
 571                  * network as the target.
 572                  * The final determination is made by supply_out().
 573                  */
 574                 if (!(RT->rt_state & RS_IF) && !(RT->rt_state & RS_MHOME) &&
 575                     RT->rt_gate != loopaddr)
 576                         nhop = RT->rt_gate;
 577                 else
 578                         nhop = 0;
 579         }
 580
 581         metric = RT->rt_metric;
 582         ags = 0;
 583
 584         if (!RT_ISHOST(RT)) {
 585                 /*
 586                  * Always suppress network routes into other, existing
 587                  * network routes
 588                  */
 589                 ags |= AGS_SUPPRESS;
 590
 591                 /*
 592                  * Generate supernets if allowed.
 593                  * If we can be heard by RIPv1 systems, we will
 594                  * later convert back to ordinary nets.
 595                  * This unifies dealing with received supernets.
 596                  */
 597                 if ((ws.state & WS_ST_AG) && ((RT->rt_state & RS_SUBNET) ||
 598                     (ws.state & WS_ST_SUPER_AG)))
 599                         ags |= AGS_AGGREGATE;
 600         } else if (!(RT->rt_state & RS_MHOME)) {
 601                 /*
 602                  * We should always suppress (into existing network routes)
 603                  * the host routes for the local end of our point-to-point
 604                  * links.
 605                  * If we are suppressing host routes in general, then do so.
 606                  * Avoid advertising host routes onto their own network,
 607                  * where they should be handled by proxy-ARP.
 608                  */
 609                 if ((RT->rt_state & RS_LOCAL) || ridhosts ||
 610                     on_net(dst, ws.to_net, ws.to_mask))
 611                         ags |= AGS_SUPPRESS;
 612
 613                 /*
 614                  * Aggregate stray host routes into network routes if allowed.
 615                  * We cannot aggregate host routes into small network routes
 616                  * without confusing RIPv1 listeners into thinking the
 617                  * network routes are host routes.
 618                  */
 619                 if ((ws.state & WS_ST_AG) && (ws.state & WS_ST_RIP2_ALL))
 620                         ags |= AGS_AGGREGATE;
 621         }
 622
 623         /*
 624          * Do not send RIPv1 advertisements of subnets to other
 625          * networks. If possible, multicast them by RIPv2.
 626          */
 627         if ((RT->rt_state & RS_SUBNET) && !(ws.state & WS_ST_RIP2_ALL) &&
 628             !on_net(dst, ws.to_std_net, ws.to_std_mask))
 629                 ags |= AGS_RIPV2 | AGS_AGGREGATE;
 630
 631
 632         /*
 633          * Do not send a route back to where it came from, except in
 634          * response to a query.  This is "split-horizon".  That means not
 635          * advertising back to the same network and so via the same interface.
 636          *
 637          * We want to suppress routes that might have been fragmented
 638          * from this route by a RIPv1 router and sent back to us, and so we
 639          * cannot forget this route here.  Let the split-horizon route
 640          * suppress the fragmented routes and then itself be forgotten.
 641          *
 642          * Include the routes for both ends of point-to-point interfaces
 643          * among those suppressed by split-horizon, since the other side
 644          * should knows them as well as we do.
 645          *
 646          * Notice spare routes with the same metric that we are about to
 647          * advertise, to split the horizon on redundant, inactive paths.
 648          */
 649         if (ws.ifp != NULL && !(ws.state & WS_ST_QUERY) &&
 650             (ws.state & WS_ST_TO_ON_NET) && (!(RT->rt_state & RS_IF) ||
 651             (ws.ifp->int_if_flags & IFF_POINTOPOINT))) {
 652                 for (rts = RT->rt_spares, sparecount = 0;
 653                     sparecount < RT->rt_num_spares; sparecount++, rts++) {
 654                         if (rts->rts_metric > metric || rts->rts_ifp != ws.ifp)
 655                                 continue;
 656
 657                         /*
 658                          * If we do not mark the route with AGS_SPLIT_HZ here,
 659                          * it will be poisoned-reverse, or advertised back
 660                          * toward its source with an infinite metric.
 661                          * If we have recently advertised the route with a
 662                          * better metric than we now have, then we should
 663                          * poison-reverse the route before suppressing it for
 664                          * split-horizon.
 665                          *
 666                          * In almost all cases, if there is no spare for the
 667                          * route then it is either old and dead or a brand
 668                          * new route. If it is brand new, there is no need
 669                          * for poison-reverse. If it is old and dead, it
 670                          * is already poisoned.
 671                          */
 672                         if (RT->rt_poison_time < now_expire ||
 673                             RT->rt_poison_metric >= metric ||
 674                             RT->rt_spares[1].rts_gate == 0) {
 675                                 ags |= AGS_SPLIT_HZ;
 676                                 ags &= ~AGS_SUPPRESS;
 677                         }
 678                         metric = HOPCNT_INFINITY;
 679                         break;
 680                 }
 681         }
 682
 683         /*
 684          * Keep track of the best metric with which the
 685          * route has been advertised recently.
 686          */
 687         if (RT->rt_poison_metric >= metric ||
 688             RT->rt_poison_time < now_expire) {
 689                 RT->rt_poison_time = now.tv_sec;
 690                 RT->rt_poison_metric = metric;
 691         }
 692
 693         /*
 694          * Adjust the outgoing metric by the cost of the link.
 695          * Avoid aggregation when a route is counting to infinity.
 696          */
 697         pref = RT->rt_poison_metric + ws.metric;
 698         metric += ws.metric;
 699
 700         /*
 701          * If this is a static route pointing to the same interface
 702          * upon which we are sending out the RIP RESPONSE
 703          * adjust the preference so that we don't aggregate into this
 704          * route. Note that the maximum possible hop count on a route
 705          * per RFC 2453 is 16 (HOPCNT_INFINITY)
 706          */
 707         if ((RT->rt_state & RS_STATIC) && (ws.ifp == RT->rt_ifp))
 708                 pref = (HOPCNT_INFINITY+1);
 709
 710         /*
 711          * Do not advertise stable routes that will be ignored,
 712          * unless we are answering a query.
 713          * If the route recently was advertised with a metric that
 714          * would have been less than infinity through this interface,
 715          * we need to continue to advertise it in order to poison it.
 716          */
 717         if (metric >= HOPCNT_INFINITY) {
 718                 if (!(ws.state & WS_ST_QUERY) && (pref >= HOPCNT_INFINITY ||
 719                     RT->rt_poison_time < now_garbage))
 720                         return (0);
 721
 722                 metric = HOPCNT_INFINITY;
 723         }
 724
 725         /*
 726          * supply this route out on the wire- we only care about dest/mask
 727          * and so can ignore all rt_spares[i] with i > 0
 728          */
 729         ag_check(dst, RT->rt_mask, 0, RT->rt_ifp, nhop, metric, pref,
 730             RT->rt_seqno, RT->rt_tag, ags, supply_out);
 731         return (0);
 732 #undef RT
 733 }
 734
 735
 736 /*
 737  * Supply dst with the contents of the routing tables.
 738  * If this won't fit in one packet, chop it up into several.
 739  */
 740 void
 741 supply(struct sockaddr_in *dst,
 742     struct interface *ifp,      /* output interface */
 743     enum output_type type,
 744     int flash,                  /* 1=flash update */
 745     int vers,                   /* RIP version */
 746     boolean_t passwd_ok)        /* OK to include cleartext password */
 747 {
 748         struct rt_entry *rt;
 749         uint8_t def_metric;
 750
 751
 752         ws.state = 0;
 753         ws.gen_limit = WS_GEN_LIMIT_MAX;
 754
 755         ws.to = *dst;
 756         ws.to_std_mask = std_mask(ws.to.sin_addr.s_addr);
 757         ws.to_std_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_std_mask;
 758
 759         if (ifp != NULL) {
 760                 ws.to_mask = ifp->int_mask;
 761                 ws.to_net = ifp->int_net;
 762                 if (on_net(ws.to.sin_addr.s_addr, ws.to_net, ws.to_mask) ||
 763                     type == OUT_MULTICAST)
 764                         ws.state |= WS_ST_TO_ON_NET;
 765
 766         } else {
 767                 ws.to_mask = ripv1_mask_net(ws.to.sin_addr.s_addr, NULL);
 768                 ws.to_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_mask;
 769                 rt = rtfind(dst->sin_addr.s_addr);
 770                 if (rt != NULL)
 771                         ifp = rt->rt_ifp;
 772                 else
 773                         return;
 774         }
 775
 776         ws.npackets = 0;
 777         if (flash)
 778                 ws.state |= WS_ST_FLASH;
 779
 780         ws.ifp = ifp;
 781
 782         /*
 783          * Routes in the table were already adjusted by their respective
 784          * destination interface costs (which are zero by default) on
 785          * input.  The following is the value by which each route's metric
 786          * will be bumped up on output.
 787          */
 788         ws.metric = 1;
 789
 790         ripv12_buf.rip.rip_vers = vers;
 791
 792         switch (type) {
 793         case OUT_MULTICAST:
 794                 if (ifp->int_if_flags & IFF_MULTICAST)
 795                         v2buf.type = OUT_MULTICAST;
 796                 else
 797                         v2buf.type = NO_OUT_MULTICAST;
 798                 v12buf.type = OUT_BROADCAST;
 799                 break;
 800
 801         case OUT_QUERY:
 802                 ws.state |= WS_ST_QUERY;
 803                 /* FALLTHROUGH */
 804         case OUT_BROADCAST:
 805         case OUT_UNICAST:
 806                 v2buf.type = (vers == RIPv2) ? type : NO_OUT_RIPV2;
 807                 v12buf.type = type;
 808                 break;
 809
 810         case NO_OUT_MULTICAST:
 811         case NO_OUT_RIPV2:
 812                 return;                 /* no output */
 813         }
 814
 815         if (vers == RIPv2) {
 816                 /* full RIPv2 only if cannot be heard by RIPv1 listeners */
 817                 if (type != OUT_BROADCAST)
 818                         ws.state |= WS_ST_RIP2_ALL;
 819                 if ((ws.state & WS_ST_QUERY) || !(ws.state & WS_ST_TO_ON_NET)) {
 820                         ws.state |= (WS_ST_AG | WS_ST_SUPER_AG);
 821                 } else if (ifp == NULL || !(ifp->int_state & IS_NO_AG)) {
 822                         ws.state |= WS_ST_AG;
 823                         if (type != OUT_BROADCAST && (ifp == NULL ||
 824                             !(ifp->int_state & IS_NO_SUPER_AG)))
 825                                 ws.state |= WS_ST_SUPER_AG;
 826                 }
 827
 828                 /* See if this packet needs authenticating */
 829                 ws.a = find_auth(ifp);
 830                 if (!passwd_ok && ws.a != NULL && ws.a->type == RIP_AUTH_PW)
 831                         ws.a = NULL;
 832                 if (ws.a != NULL && (ulong_t)ws.a->end < (ulong_t)clk.tv_sec &&
 833                     !ws.a->warnedflag) {
 834                         /*
 835                          * If the best key is an expired one, we may as
 836                          * well use it.  Log this event.
 837                          */
 838                         writelog(LOG_WARNING,
 839                             "Using expired auth while transmitting to %s",
 840                             naddr_ntoa(ws.to.sin_addr.s_addr));
 841                         ws.a->warnedflag = 1;
 842                 }
 843         } else {
 844                 ws.a = NULL;
 845         }
 846
 847         clr_ws_buf(&v12buf, ws.a);
 848         clr_ws_buf(&v2buf, ws.a);
 849
 850         /*
 851          * Fake a default route if asked and if there is not already
 852          * a better, real default route.
 853          */
 854         if (should_supply(NULL) && (def_metric = ifp->int_d_metric) != 0) {
 855                 if (NULL == (rt = rtget(RIP_DEFAULT, 0)) ||
 856                     rt->rt_metric+ws.metric >= def_metric) {
 857                         ws.state |= WS_ST_DEFAULT;
 858                         ag_check(0, 0, 0, NULL, 0, def_metric, def_metric,
 859                             0, 0, 0, supply_out);
 860                 } else {
 861                         def_metric = rt->rt_metric+ws.metric;
 862                 }
 863
 864                 /*
 865                  * If both RIPv2 and the poor-man's router discovery
 866                  * kludge are on, arrange to advertise an extra
 867                  * default route via RIPv1.
 868                  */
 869                 if ((ws.state & WS_ST_RIP2_ALL) &&
 870                     (ifp->int_state & IS_PM_RDISC)) {
 871                         ripv12_buf.rip.rip_vers = RIPv1;
 872                         v12buf.n->n_family = RIP_AF_INET;
 873                         v12buf.n->n_dst = htonl(RIP_DEFAULT);
 874                         v12buf.n->n_metric = htonl(def_metric);
 875                         v12buf.n++;
 876                 }
 877         }
 878
 879         (void) rn_walktree(rhead, walk_supply, NULL);
 880         ag_flush(0, 0, supply_out);
 881
 882         /*
 883          * Flush the packet buffers, provided they are not empty and
 884          * do not contain only the password.
 885          */
 886         if (v12buf.n != v12buf.base &&
 887             (v12buf.n > v12buf.base+1 ||
 888             v12buf.base->n_family != RIP_AF_AUTH))
 889                 supply_write(&v12buf);
 890         if (v2buf.n != v2buf.base && (v2buf.n > v2buf.base+1 ||
 891             v2buf.base->n_family != RIP_AF_AUTH))
 892                 supply_write(&v2buf);
 893
 894         /*
 895          * If we sent nothing and this is an answer to a query, send
 896          * an empty buffer.
 897          */
 898         if (ws.npackets == 0 && (ws.state & WS_ST_QUERY)) {
 899                 supply_write(&v2buf);
 900                 if (ws.npackets == 0)
 901                         supply_write(&v12buf);
 902         }
 903 }
 904
 905
 906 /*
 907  * send all of the routing table or just do a flash update
 908  */
 909 void
 910 rip_bcast(int flash)
 911 {
 912         static struct sockaddr_in dst = {AF_INET};
 913         struct interface *ifp;
 914         enum output_type type;
 915         int vers;
 916         struct timeval rtime;
 917
 918
 919         need_flash = _B_FALSE;
 920         intvl_random(&rtime, MIN_WAITTIME, MAX_WAITTIME);
 921         no_flash = rtime;
 922         timevaladd(&no_flash, &now);
 923
 924         if (!rip_enabled)
 925                 return;
 926
 927         trace_act("send %s and inhibit dynamic updates for %.3f sec",
 928             flash ? "dynamic update" : "all routes",
 929             rtime.tv_sec + ((double)rtime.tv_usec)/1000000.0);
 930
 931         for (ifp = ifnet; ifp != NULL; ifp = ifp->int_next) {
 932                 /*
 933                  * Skip interfaces not doing RIP or for which IP
 934                  * forwarding isn't turned on.  Skip duplicate
 935                  * interfaces, we don't want to generate duplicate
 936                  * packets.  Do try broken interfaces to see if they
 937                  * have healed.
 938                  */
 939                 if (IS_RIP_OUT_OFF(ifp->int_state) ||
 940                     (ifp->int_state & IS_DUP) ||
 941                     !IS_IFF_ROUTING(ifp->int_if_flags))
 942                         continue;
 943
 944                 /* skip turned off interfaces */
 945                 if (!IS_IFF_UP(ifp->int_if_flags))
 946                         continue;
 947
 948                 /* skip interfaces we shouldn't use */
 949                 if (IS_IFF_QUIET(ifp->int_if_flags))
 950                         continue;
 951
 952                 vers = (ifp->int_state & IS_NO_RIPV1_OUT) ? RIPv2 : RIPv1;
 953                 dst.sin_addr.s_addr = ifp->int_ripout_addr;
 954
 955                 /*
 956                  * Ignore the interface if it's not broadcast,
 957                  * point-to-point, or remote.  It must be non-broadcast
 958                  * multiaccess, and therefore unsupported.
 959                  */
 960                 if (!(ifp->int_if_flags & (IFF_BROADCAST | IFF_POINTOPOINT)) &&
 961                     !(ifp->int_state & IS_REMOTE))
 962                         continue;
 963
 964                 type = (ifp->int_if_flags & IFF_BROADCAST) ?
 965                     OUT_BROADCAST : OUT_UNICAST;
 966                 if (vers == RIPv2 && (ifp->int_if_flags & IFF_MULTICAST) &&
 967                     !(ifp->int_state & IS_NO_RIP_MCAST))
 968                         type = OUT_MULTICAST;
 969
 970                 supply(&dst, ifp, type, flash, vers, _B_TRUE);
 971         }
 972
 973         update_seqno++;                 /* all routes are up to date */
 974 }
 975
 976
 977 /*
 978  * Ask for routes
 979  * Do it only once to an interface, and not even after the interface
 980  * was broken and recovered.
 981  */
 982 void
 983 rip_query(void)
 984 {
 985         static struct sockaddr_in dst = {AF_INET};
 986         struct interface *ifp;
 987         struct rip buf;
 988         enum output_type type;
 989
 990
 991         if (!rip_enabled)
 992                 return;
 993
 994         (void) memset(&buf, 0, sizeof (buf));
 995
 996         for (ifp = ifnet; ifp; ifp = ifp->int_next) {
 997                 /*
 998                  * Skip interfaces those already queried.  Do not ask
 999                  * via interfaces through which we don't accept input.
1000                  * Do not ask via interfaces that cannot send RIP
1001                  * packets.  Don't send queries on duplicate
1002                  * interfaces, that would generate duplicate packets
1003                  * on link.  Do try broken interfaces to see if they
1004                  * have healed.
1005                  */
1006                 if (IS_RIP_IN_OFF(ifp->int_state) ||
1007                     (ifp->int_state & IS_DUP) ||
1008                     ifp->int_query_time != NEVER)
1009                         continue;
1010
1011                 /* skip turned off interfaces */
1012                 if (!IS_IFF_UP(ifp->int_if_flags))
1013                         continue;
1014
1015                 /* skip interfaces we shouldn't use */
1016                 if (IS_IFF_QUIET(ifp->int_if_flags))
1017                         continue;
1018
1019                 /*
1020                  * Ignore the interface if it's not broadcast,
1021                  * point-to-point, or remote.  It must be non-broadcast
1022                  * multiaccess, and therefore unsupported.
1023                  */
1024                 if (!(ifp->int_if_flags & (IFF_BROADCAST | IFF_POINTOPOINT)) &&
1025                     !(ifp->int_state & IS_REMOTE))
1026                         continue;
1027
1028                 buf.rip_cmd = RIPCMD_REQUEST;
1029                 buf.rip_nets[0].n_family = RIP_AF_UNSPEC;
1030                 buf.rip_nets[0].n_metric = htonl(HOPCNT_INFINITY);
1031
1032                 /*
1033                  * Send a RIPv1 query only if allowed and if we will
1034                  * listen to RIPv1 routers.
1035                  */
1036                 if ((ifp->int_state & IS_NO_RIPV1_OUT) ||
1037                     (ifp->int_state & IS_NO_RIPV1_IN)) {
1038                         buf.rip_vers = RIPv2;
1039                 } else {
1040                         buf.rip_vers = RIPv1;
1041                 }
1042
1043                 dst.sin_addr.s_addr = ifp->int_ripout_addr;
1044
1045                 type = (ifp->int_if_flags & IFF_BROADCAST) ?
1046                     OUT_BROADCAST : OUT_UNICAST;
1047                 if (buf.rip_vers == RIPv2 &&
1048                     (ifp->int_if_flags & IFF_MULTICAST) &&
1049                     !(ifp->int_state & IS_NO_RIP_MCAST))
1050                         type = OUT_MULTICAST;
1051
1052                 ifp->int_query_time = now.tv_sec+SUPPLY_INTERVAL;
1053                 if (output(type, &dst, ifp, &buf, sizeof (buf)) < 0)
1054                         if_sick(ifp, _B_FALSE);
1055         }
1056 }