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 #include "defs.h" 40 #include <md5.h> 41 #include <alloca.h> 42 43 uint_t update_seqno; 44 45 46 /* 47 * walk the tree of routes with this for output 48 */ 49 static struct { 50 struct sockaddr_in to; 51 in_addr_t to_mask; 52 in_addr_t to_net; 53 in_addr_t to_std_mask; 54 in_addr_t to_std_net; 55 struct interface *ifp; /* usually output interface */ 56 struct auth *a; 57 uint8_t metric; /* adjust metrics by interface */ 58 uint32_t npackets; 59 uint32_t gen_limit; 60 #define WS_GEN_LIMIT_MAX 1024 61 uint16_t 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 static union pkt_buf ripv12_buf; 74 75 /* Another for only RIPv2 listeners */ 76 static struct ws_buf v2buf; 77 static 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 /* 96 * Send the contents of the global buffer via the non-multicast socket 97 */ 98 int /* <0 on failure */ 99 output(enum output_type type, 100 struct sockaddr_in *dst, /* send to here */ 101 struct interface *ifp, 102 struct rip *buf, 103 int size) /* this many bytes */ 104 { 105 struct sockaddr_in sin; 106 int flags; 107 const char *msg; 108 int res; 109 int ifindex; 110 struct in_addr addr; 111 112 sin = *dst; 113 if (sin.sin_port == 0) 114 sin.sin_port = htons(RIP_PORT); 115 116 flags = 0; 117 118 if (ifp == NULL && type == OUT_MULTICAST) { 119 msglog("Cannot send RIP message to %s", 120 inet_ntoa(sin.sin_addr)); 121 return (-1); 122 } 123 124 switch (type) { 125 case OUT_QUERY: 126 msg = "Answer Query"; 127 break; 128 case OUT_UNICAST: 129 msg = "Send"; 130 flags = MSG_DONTROUTE; 131 break; 132 case OUT_BROADCAST: 133 msg = "Send bcast"; 134 break; 135 case OUT_MULTICAST: 136 msg = "Send mcast"; 137 break; 138 139 case NO_OUT_MULTICAST: 140 case NO_OUT_RIPV2: 141 default: 142 #ifdef DEBUG 143 abort(); 144 #endif 145 return (-1); 146 } 147 148 /* 149 * IP_PKTINFO overrides IP_MULTICAST_IF, so we don't set ifindex 150 * for multicast traffic. 151 */ 152 ifindex = (type != OUT_MULTICAST && type != OUT_QUERY && 153 ifp != NULL && ifp->int_phys != NULL) ? 154 ifp->int_phys->phyi_index : 0; 155 156 if (rip_sock_interface != ifp) { 157 /* 158 * For multicast, we have to choose the source 159 * address. This is either the local address 160 * (non-point-to-point) or the remote address. 161 */ 162 if (ifp != NULL) { 163 addr.s_addr = (ifp->int_if_flags & IFF_POINTOPOINT) ? 164 ifp->int_dstaddr : ifp->int_addr; 165 if (type == OUT_MULTICAST && 166 setsockopt(rip_sock, IPPROTO_IP, 167 IP_MULTICAST_IF, &addr, sizeof (addr)) == -1) { 168 LOGERR("setsockopt(rip_sock, IP_MULTICAST_IF)"); 169 return (-1); 170 } 171 } 172 rip_sock_interface = ifp; 173 } 174 175 trace_rip(msg, "to", &sin, ifp, buf, size); 176 177 res = sendtoif(rip_sock, buf, size, flags, &sin, ifindex); 178 if (res < 0 && (ifp == NULL || !(ifp->int_state & IS_BROKE))) { 179 writelog(LOG_WARNING, "%s sendto(%s%s%s.%d): %s", msg, 180 ifp != NULL ? ifp->int_name : "", 181 ifp != NULL ? ", " : "", 182 inet_ntoa(sin.sin_addr), 183 ntohs(sin.sin_port), 184 rip_strerror(errno)); 185 } 186 187 return (res); 188 } 189 190 /* 191 * Semantically identical to sendto(), but sends the message through a 192 * specific interface (if ifindex is non-zero) using IP_PKTINFO. 193 */ 194 int 195 sendtoif(int fd, const void *buf, uint_t bufsize, uint_t flags, 196 struct sockaddr_in *sinp, uint_t ifindex) 197 { 198 struct iovec iov; 199 struct msghdr msg; 200 struct cmsghdr *cmsgp; 201 struct in_pktinfo *ipip; 202 203 iov.iov_base = (void *)buf; 204 iov.iov_len = bufsize; 205 206 (void) memset(&msg, 0, sizeof (struct msghdr)); 207 msg.msg_name = (struct sockaddr *)sinp; 208 msg.msg_namelen = sizeof (struct sockaddr_in); 209 msg.msg_iov = &iov; 210 msg.msg_iovlen = 1; 211 212 if (ifindex != 0) { 213 /* 214 * We can't precisely predict the alignment padding we'll 215 * need, so we allocate the maximum alignment and then 216 * use CMSG_NXTHDR() to fix it up at the end. 217 */ 218 msg.msg_controllen = sizeof (*cmsgp) + _MAX_ALIGNMENT + 219 sizeof (*ipip) + _MAX_ALIGNMENT + sizeof (*cmsgp); 220 msg.msg_control = alloca(msg.msg_controllen); 221 222 cmsgp = CMSG_FIRSTHDR(&msg); 223 ipip = (void *)CMSG_DATA(cmsgp); 224 (void) memset(ipip, 0, sizeof (struct in_pktinfo)); 225 ipip->ipi_ifindex = ifindex; 226 cmsgp->cmsg_len = (caddr_t)(ipip + 1) - (caddr_t)cmsgp; 227 cmsgp->cmsg_type = IP_PKTINFO; 228 cmsgp->cmsg_level = IPPROTO_IP; 229 230 /* 231 * Correct the control message length. 232 */ 233 cmsgp = CMSG_NXTHDR(&msg, cmsgp); 234 msg.msg_controllen = (caddr_t)cmsgp - (caddr_t)msg.msg_control; 235 } 236 237 return (sendmsg(fd, &msg, flags)); 238 } 239 240 /* 241 * Find the first key for a packet to send. 242 * Try for a key that is eligible and has not expired, but settle for 243 * the last key if they have all expired. 244 * If no key is ready yet, give up. 245 */ 246 struct auth * 247 find_auth(struct interface *ifp) 248 { 249 struct auth *ap, *res = NULL; 250 int i; 251 252 253 if (ifp == NULL) 254 return (NULL); 255 256 if ((ap = ifp->int_auth) == NULL) 257 return (NULL); 258 259 for (i = 0; i < MAX_AUTH_KEYS; i++, ap++) { 260 /* stop looking after the last key */ 261 if (ap->type == RIP_AUTH_NONE) 262 break; 263 264 /* ignore keys that are not ready yet */ 265 if ((ulong_t)ap->start > (ulong_t)clk.tv_sec) 266 continue; 267 268 if ((ulong_t)ap->end < (ulong_t)clk.tv_sec) { 269 /* note best expired password as a fall-back */ 270 if (res == NULL || 271 (((ulong_t)ap->end > (ulong_t)res->end)) && 272 ((ulong_t)res->end < (ulong_t)clk.tv_sec)) 273 res = ap; 274 continue; 275 } 276 277 /* note key with the best future */ 278 if (res == NULL || (ulong_t)res->end < (ulong_t)ap->end) 279 res = ap; 280 } 281 return (res); 282 } 283 284 285 void 286 clr_ws_buf(struct ws_buf *wb, struct auth *ap) 287 { 288 struct netauth *na; 289 290 wb->lim = wb->base + NETS_LEN; 291 wb->n = wb->base; 292 (void) memset(wb->n, 0, NETS_LEN*sizeof (*wb->n)); 293 294 /* 295 * (start to) install authentication if appropriate 296 */ 297 if (ap == NULL) 298 return; 299 300 na = (struct netauth *)wb->n; 301 if (ap->type == RIP_AUTH_PW) { 302 na->a_family = RIP_AF_AUTH; 303 na->a_type = RIP_AUTH_PW; 304 (void) memcpy(na->au.au_pw, ap->key, sizeof (na->au.au_pw)); 305 wb->n++; 306 307 } else if (ap->type == RIP_AUTH_MD5) { 308 na->a_family = RIP_AF_AUTH; 309 na->a_type = RIP_AUTH_MD5; 310 na->au.a_md5.md5_keyid = ap->keyid; 311 na->au.a_md5.md5_auth_len = RIP_AUTH_MD5_LEN; 312 na->au.a_md5.md5_seqno = htonl(clk.tv_sec); 313 wb->n++; 314 wb->lim--; /* make room for trailer */ 315 } 316 } 317 318 319 void 320 end_md5_auth(struct ws_buf *wb, struct auth *ap) 321 { 322 struct netauth *na, *na2; 323 MD5_CTX md5_ctx; 324 int len; 325 326 na = (struct netauth *)wb->base; 327 na2 = (struct netauth *)wb->n; 328 len = (char *)na2-(char *)wb->buf; 329 na2->a_family = RIP_AF_AUTH; 330 na2->a_type = RIP_AUTH_TRAILER; 331 na->au.a_md5.md5_pkt_len = htons(len); 332 MD5Init(&md5_ctx); 333 /* len+4 to include auth trailer's family/type in MD5 sum */ 334 MD5Update(&md5_ctx, (uchar_t *)wb->buf, len + 4); 335 MD5Update(&md5_ctx, ap->key, RIP_AUTH_MD5_LEN); 336 MD5Final(na2->au.au_pw, &md5_ctx); 337 wb->n++; 338 } 339 340 341 /* 342 * Send the buffer 343 */ 344 static void 345 supply_write(struct ws_buf *wb) 346 { 347 /* 348 * Output multicast only if legal. 349 * If we would multicast and it would be illegal, then discard the 350 * packet. 351 */ 352 switch (wb->type) { 353 case NO_OUT_MULTICAST: 354 trace_pkt("skip multicast to %s because impossible", 355 naddr_ntoa(ws.to.sin_addr.s_addr)); 356 break; 357 case NO_OUT_RIPV2: 358 break; 359 default: 360 if (ws.a != NULL && ws.a->type == RIP_AUTH_MD5) 361 end_md5_auth(wb, ws.a); 362 if (output(wb->type, &ws.to, ws.ifp, wb->buf, 363 ((char *)wb->n - (char *)wb->buf)) < 0 && ws.ifp != NULL) 364 if_sick(ws.ifp, _B_FALSE); 365 ws.npackets++; 366 break; 367 } 368 369 clr_ws_buf(wb, ws.a); 370 } 371 372 373 /* 374 * Put an entry into the packet 375 */ 376 static void 377 supply_out(struct ag_info *ag) 378 { 379 uint32_t dstcount; 380 in_addr_t mask, v1_mask, dst_h, ddst_h = 0; 381 struct ws_buf *wb; 382 383 384 /* 385 * Skip this route if doing a flash update and it and the routes 386 * it aggregates have not changed recently. 387 */ 388 if (ag->ag_seqno < update_seqno && (ws.state & WS_ST_FLASH)) 389 return; 390 391 dst_h = ag->ag_dst_h; 392 mask = ag->ag_mask; 393 v1_mask = ripv1_mask_host(htonl(dst_h), 394 (ws.state & WS_ST_TO_ON_NET) ? ws.ifp : NULL); 395 dstcount = 0; 396 397 /* 398 * If we are sending RIPv2 packets that cannot (or must not) be 399 * heard by RIPv1 listeners, do not worry about sub- or supernets. 400 * Subnets (from other networks) can only be sent via multicast. 401 * A pair of subnet routes might have been promoted so that they 402 * are legal to send by RIPv1. 403 * If RIPv1 is off, use the multicast buffer. 404 */ 405 if ((ws.state & WS_ST_RIP2_ALL) || 406 ((ag->ag_state & AGS_RIPV2) && v1_mask != mask)) { 407 /* use the RIPv2-only buffer */ 408 wb = &v2buf; 409 410 } else { 411 /* 412 * use the RIPv1-or-RIPv2 buffer 413 */ 414 wb = &v12buf; 415 416 /* 417 * Convert supernet route into corresponding set of network 418 * routes for RIPv1, but leave non-contiguous netmasks 419 * to ag_check(). 420 */ 421 if (v1_mask > mask && 422 mask + (mask & -mask) == 0) { 423 ddst_h = v1_mask & -v1_mask; 424 dstcount = (v1_mask & ~mask)/ddst_h; 425 426 if (dstcount > ws.gen_limit) { 427 /* 428 * Punt if we would have to generate an 429 * unreasonable number of routes. 430 */ 431 if (TRACECONTENTS) 432 trace_misc("sending %s-->%s as 1" 433 " instead of %d routes", 434 addrname(htonl(dst_h), mask, 1), 435 naddr_ntoa(ws.to.sin_addr.s_addr), 436 dstcount + 1); 437 dstcount = 0; 438 439 } else { 440 mask = v1_mask; 441 ws.gen_limit -= dstcount; 442 } 443 } 444 } 445 446 do { 447 wb->n->n_family = RIP_AF_INET; 448 wb->n->n_dst = htonl(dst_h); 449 /* 450 * If the route is from router-discovery or we are 451 * shutting down, or this is a broken/sick interface, 452 * admit only a bad metric. 453 */ 454 wb->n->n_metric = ((stopint || ag->ag_metric < 1 || 455 (ag->ag_ifp && (ag->ag_ifp->int_state & 456 (IS_BROKE|IS_SICK)))) ? HOPCNT_INFINITY : ag->ag_metric); 457 wb->n->n_metric = htonl(wb->n->n_metric); 458 /* 459 * Any non-zero bits in the supposedly unused RIPv1 fields 460 * cause the old `routed` to ignore the route. 461 * That means the mask and so forth cannot be sent 462 * in the hybrid RIPv1/RIPv2 mode. 463 */ 464 if (ws.state & WS_ST_RIP2_ALL) { 465 if (ag->ag_nhop != 0 && 466 ((ws.state & WS_ST_QUERY) || 467 (ag->ag_nhop != ws.ifp->int_addr && 468 on_net(ag->ag_nhop, ws.ifp->int_net, 469 ws.ifp->int_mask)) && 470 ifwithaddr(ag->ag_nhop, _B_FALSE, _B_FALSE) == 471 NULL)) 472 wb->n->n_nhop = ag->ag_nhop; 473 wb->n->n_mask = htonl(mask); 474 wb->n->n_tag = ag->ag_tag; 475 } 476 dst_h += ddst_h; 477 478 if (++wb->n >= wb->lim) 479 supply_write(wb); 480 } while (dstcount-- > 0); 481 } 482 483 484 /* 485 * Supply one route from the table 486 */ 487 /* ARGSUSED */ 488 static int 489 walk_supply(struct radix_node *rn, void *argp) 490 { 491 #define RT ((struct rt_entry *)rn) 492 ushort_t ags; 493 uint8_t metric, pref; 494 in_addr_t dst, nhop; 495 struct rt_spare *rts; 496 uint_t sparecount; 497 498 499 /* 500 * Do not advertise external remote interfaces or passive interfaces. 501 */ 502 if ((RT->rt_state & RS_IF) && RT->rt_ifp != NULL && 503 (RT->rt_ifp->int_state & IS_PASSIVE) && 504 !(RT->rt_state & RS_MHOME)) 505 return (0); 506 /* 507 * Do not advertise routes learnt from /etc/gateways. 508 */ 509 if (RT->rt_spares[0].rts_origin == RO_FILE) 510 return (0); 511 512 /* 513 * Do not advertise routes which would lead to forwarding on a 514 * non-forwarding interface. 515 */ 516 if (RT->rt_state & RS_NOPROPAGATE) 517 return (0); 518 519 /* 520 * If being quiet about our ability to forward, then 521 * do not say anything unless responding to a query, 522 * except about our main interface. 523 */ 524 if (!should_supply(NULL) && !(ws.state & WS_ST_QUERY) && 525 !(RT->rt_state & RS_MHOME)) 526 return (0); 527 528 dst = RT->rt_dst; 529 530 /* 531 * do not collide with the fake default route 532 */ 533 if (dst == RIP_DEFAULT && (ws.state & WS_ST_DEFAULT)) 534 return (0); 535 536 if (RT->rt_state & RS_NET_SYN) { 537 if (RT->rt_state & RS_NET_INT) { 538 /* 539 * Do not send manual synthetic network routes 540 * into the subnet. 541 */ 542 if (on_net(ws.to.sin_addr.s_addr, 543 ntohl(dst), RT->rt_mask)) 544 return (0); 545 546 } else { 547 /* 548 * Do not send automatic synthetic network routes 549 * if they are not needed because no RIPv1 listeners 550 * can hear them. 551 */ 552 if (ws.state & WS_ST_RIP2_ALL) 553 return (0); 554 555 /* 556 * Do not send automatic synthetic network routes to 557 * the real subnet. 558 */ 559 if (on_net(ws.to.sin_addr.s_addr, 560 ntohl(dst), RT->rt_mask)) 561 return (0); 562 } 563 nhop = 0; 564 565 } else { 566 /* 567 * Advertise the next hop if this is not a route for one 568 * of our interfaces and the next hop is on the same 569 * network as the target. 570 * The final determination is made by supply_out(). 571 */ 572 if (!(RT->rt_state & RS_IF) && !(RT->rt_state & RS_MHOME) && 573 RT->rt_gate != loopaddr) 574 nhop = RT->rt_gate; 575 else 576 nhop = 0; 577 } 578 579 metric = RT->rt_metric; 580 ags = 0; 581 582 if (!RT_ISHOST(RT)) { 583 /* 584 * Always suppress network routes into other, existing 585 * network routes 586 */ 587 ags |= AGS_SUPPRESS; 588 589 /* 590 * Generate supernets if allowed. 591 * If we can be heard by RIPv1 systems, we will 592 * later convert back to ordinary nets. 593 * This unifies dealing with received supernets. 594 */ 595 if ((ws.state & WS_ST_AG) && ((RT->rt_state & RS_SUBNET) || 596 (ws.state & WS_ST_SUPER_AG))) 597 ags |= AGS_AGGREGATE; 598 } else if (!(RT->rt_state & RS_MHOME)) { 599 /* 600 * We should always suppress (into existing network routes) 601 * the host routes for the local end of our point-to-point 602 * links. 603 * If we are suppressing host routes in general, then do so. 604 * Avoid advertising host routes onto their own network, 605 * where they should be handled by proxy-ARP. 606 */ 607 if ((RT->rt_state & RS_LOCAL) || ridhosts || 608 on_net(dst, ws.to_net, ws.to_mask)) 609 ags |= AGS_SUPPRESS; 610 611 /* 612 * Aggregate stray host routes into network routes if allowed. 613 * We cannot aggregate host routes into small network routes 614 * without confusing RIPv1 listeners into thinking the 615 * network routes are host routes. 616 */ 617 if ((ws.state & WS_ST_AG) && (ws.state & WS_ST_RIP2_ALL)) 618 ags |= AGS_AGGREGATE; 619 } 620 621 /* 622 * Do not send RIPv1 advertisements of subnets to other 623 * networks. If possible, multicast them by RIPv2. 624 */ 625 if ((RT->rt_state & RS_SUBNET) && !(ws.state & WS_ST_RIP2_ALL) && 626 !on_net(dst, ws.to_std_net, ws.to_std_mask)) 627 ags |= AGS_RIPV2 | AGS_AGGREGATE; 628 629 630 /* 631 * Do not send a route back to where it came from, except in 632 * response to a query. This is "split-horizon". That means not 633 * advertising back to the same network and so via the same interface. 634 * 635 * We want to suppress routes that might have been fragmented 636 * from this route by a RIPv1 router and sent back to us, and so we 637 * cannot forget this route here. Let the split-horizon route 638 * suppress the fragmented routes and then itself be forgotten. 639 * 640 * Include the routes for both ends of point-to-point interfaces 641 * among those suppressed by split-horizon, since the other side 642 * should knows them as well as we do. 643 * 644 * Notice spare routes with the same metric that we are about to 645 * advertise, to split the horizon on redundant, inactive paths. 646 */ 647 if (ws.ifp != NULL && !(ws.state & WS_ST_QUERY) && 648 (ws.state & WS_ST_TO_ON_NET) && (!(RT->rt_state & RS_IF) || 649 (ws.ifp->int_if_flags & IFF_POINTOPOINT))) { 650 for (rts = RT->rt_spares, sparecount = 0; 651 sparecount < RT->rt_num_spares; sparecount++, rts++) { 652 if (rts->rts_metric > metric || rts->rts_ifp != ws.ifp) 653 continue; 654 655 /* 656 * If we do not mark the route with AGS_SPLIT_HZ here, 657 * it will be poisoned-reverse, or advertised back 658 * toward its source with an infinite metric. 659 * If we have recently advertised the route with a 660 * better metric than we now have, then we should 661 * poison-reverse the route before suppressing it for 662 * split-horizon. 663 * 664 * In almost all cases, if there is no spare for the 665 * route then it is either old and dead or a brand 666 * new route. If it is brand new, there is no need 667 * for poison-reverse. If it is old and dead, it 668 * is already poisoned. 669 */ 670 if (RT->rt_poison_time < now_expire || 671 RT->rt_poison_metric >= metric || 672 RT->rt_spares[1].rts_gate == 0) { 673 ags |= AGS_SPLIT_HZ; 674 ags &= ~AGS_SUPPRESS; 675 } 676 metric = HOPCNT_INFINITY; 677 break; 678 } 679 } 680 681 /* 682 * Keep track of the best metric with which the 683 * route has been advertised recently. 684 */ 685 if (RT->rt_poison_metric >= metric || 686 RT->rt_poison_time < now_expire) { 687 RT->rt_poison_time = now.tv_sec; 688 RT->rt_poison_metric = metric; 689 } 690 691 /* 692 * Adjust the outgoing metric by the cost of the link. 693 * Avoid aggregation when a route is counting to infinity. 694 */ 695 pref = RT->rt_poison_metric + ws.metric; 696 metric += ws.metric; 697 698 /* 699 * If this is a static route pointing to the same interface 700 * upon which we are sending out the RIP RESPONSE 701 * adjust the preference so that we don't aggregate into this 702 * route. Note that the maximum possible hop count on a route 703 * per RFC 2453 is 16 (HOPCNT_INFINITY) 704 */ 705 if ((RT->rt_state & RS_STATIC) && (ws.ifp == RT->rt_ifp)) 706 pref = (HOPCNT_INFINITY+1); 707 708 /* 709 * Do not advertise stable routes that will be ignored, 710 * unless we are answering a query. 711 * If the route recently was advertised with a metric that 712 * would have been less than infinity through this interface, 713 * we need to continue to advertise it in order to poison it. 714 */ 715 if (metric >= HOPCNT_INFINITY) { 716 if (!(ws.state & WS_ST_QUERY) && (pref >= HOPCNT_INFINITY || 717 RT->rt_poison_time < now_garbage)) 718 return (0); 719 720 metric = HOPCNT_INFINITY; 721 } 722 723 /* 724 * supply this route out on the wire- we only care about dest/mask 725 * and so can ignore all rt_spares[i] with i > 0 726 */ 727 ag_check(dst, RT->rt_mask, 0, RT->rt_ifp, nhop, metric, pref, 728 RT->rt_seqno, RT->rt_tag, ags, supply_out); 729 return (0); 730 #undef RT 731 } 732 733 734 /* 735 * Supply dst with the contents of the routing tables. 736 * If this won't fit in one packet, chop it up into several. 737 */ 738 void 739 supply(struct sockaddr_in *dst, 740 struct interface *ifp, /* output interface */ 741 enum output_type type, 742 int flash, /* 1=flash update */ 743 int vers, /* RIP version */ 744 boolean_t passwd_ok) /* OK to include cleartext password */ 745 { 746 struct rt_entry *rt; 747 uint8_t def_metric; 748 749 750 ws.state = 0; 751 ws.gen_limit = WS_GEN_LIMIT_MAX; 752 753 ws.to = *dst; 754 ws.to_std_mask = std_mask(ws.to.sin_addr.s_addr); 755 ws.to_std_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_std_mask; 756 757 if (ifp != NULL) { 758 ws.to_mask = ifp->int_mask; 759 ws.to_net = ifp->int_net; 760 if (on_net(ws.to.sin_addr.s_addr, ws.to_net, ws.to_mask) || 761 type == OUT_MULTICAST) 762 ws.state |= WS_ST_TO_ON_NET; 763 764 } else { 765 ws.to_mask = ripv1_mask_net(ws.to.sin_addr.s_addr, NULL); 766 ws.to_net = ntohl(ws.to.sin_addr.s_addr) & ws.to_mask; 767 rt = rtfind(dst->sin_addr.s_addr); 768 if (rt != NULL) 769 ifp = rt->rt_ifp; 770 else 771 return; 772 } 773 774 ws.npackets = 0; 775 if (flash) 776 ws.state |= WS_ST_FLASH; 777 778 ws.ifp = ifp; 779 780 /* 781 * Routes in the table were already adjusted by their respective 782 * destination interface costs (which are zero by default) on 783 * input. The following is the value by which each route's metric 784 * will be bumped up on output. 785 */ 786 ws.metric = 1; 787 788 ripv12_buf.rip.rip_vers = vers; 789 790 switch (type) { 791 case OUT_MULTICAST: 792 if (ifp->int_if_flags & IFF_MULTICAST) 793 v2buf.type = OUT_MULTICAST; 794 else 795 v2buf.type = NO_OUT_MULTICAST; 796 v12buf.type = OUT_BROADCAST; 797 break; 798 799 case OUT_QUERY: 800 ws.state |= WS_ST_QUERY; 801 /* FALLTHROUGH */ 802 case OUT_BROADCAST: 803 case OUT_UNICAST: 804 v2buf.type = (vers == RIPv2) ? type : NO_OUT_RIPV2; 805 v12buf.type = type; 806 break; 807 808 case NO_OUT_MULTICAST: 809 case NO_OUT_RIPV2: 810 return; /* no output */ 811 } 812 813 if (vers == RIPv2) { 814 /* full RIPv2 only if cannot be heard by RIPv1 listeners */ 815 if (type != OUT_BROADCAST) 816 ws.state |= WS_ST_RIP2_ALL; 817 if ((ws.state & WS_ST_QUERY) || !(ws.state & WS_ST_TO_ON_NET)) { 818 ws.state |= (WS_ST_AG | WS_ST_SUPER_AG); 819 } else if (ifp == NULL || !(ifp->int_state & IS_NO_AG)) { 820 ws.state |= WS_ST_AG; 821 if (type != OUT_BROADCAST && (ifp == NULL || 822 !(ifp->int_state & IS_NO_SUPER_AG))) 823 ws.state |= WS_ST_SUPER_AG; 824 } 825 826 /* See if this packet needs authenticating */ 827 ws.a = find_auth(ifp); 828 if (!passwd_ok && ws.a != NULL && ws.a->type == RIP_AUTH_PW) 829 ws.a = NULL; 830 if (ws.a != NULL && (ulong_t)ws.a->end < (ulong_t)clk.tv_sec && 831 !ws.a->warnedflag) { 832 /* 833 * If the best key is an expired one, we may as 834 * well use it. Log this event. 835 */ 836 writelog(LOG_WARNING, 837 "Using expired auth while transmitting to %s", 838 naddr_ntoa(ws.to.sin_addr.s_addr)); 839 ws.a->warnedflag = 1; 840 } 841 } else { 842 ws.a = NULL; 843 } 844 845 clr_ws_buf(&v12buf, ws.a); 846 clr_ws_buf(&v2buf, ws.a); 847 848 /* 849 * Fake a default route if asked and if there is not already 850 * a better, real default route. 851 */ 852 if (should_supply(NULL) && (def_metric = ifp->int_d_metric) != 0) { 853 if (NULL == (rt = rtget(RIP_DEFAULT, 0)) || 854 rt->rt_metric+ws.metric >= def_metric) { 855 ws.state |= WS_ST_DEFAULT; 856 ag_check(0, 0, 0, NULL, 0, def_metric, def_metric, 857 0, 0, 0, supply_out); 858 } else { 859 def_metric = rt->rt_metric+ws.metric; 860 } 861 862 /* 863 * If both RIPv2 and the poor-man's router discovery 864 * kludge are on, arrange to advertise an extra 865 * default route via RIPv1. 866 */ 867 if ((ws.state & WS_ST_RIP2_ALL) && 868 (ifp->int_state & IS_PM_RDISC)) { 869 ripv12_buf.rip.rip_vers = RIPv1; 870 v12buf.n->n_family = RIP_AF_INET; 871 v12buf.n->n_dst = htonl(RIP_DEFAULT); 872 v12buf.n->n_metric = htonl(def_metric); 873 v12buf.n++; 874 } 875 } 876 877 (void) rn_walktree(rhead, walk_supply, NULL); 878 ag_flush(0, 0, supply_out); 879 880 /* 881 * Flush the packet buffers, provided they are not empty and 882 * do not contain only the password. 883 */ 884 if (v12buf.n != v12buf.base && 885 (v12buf.n > v12buf.base+1 || 886 v12buf.base->n_family != RIP_AF_AUTH)) 887 supply_write(&v12buf); 888 if (v2buf.n != v2buf.base && (v2buf.n > v2buf.base+1 || 889 v2buf.base->n_family != RIP_AF_AUTH)) 890 supply_write(&v2buf); 891 892 /* 893 * If we sent nothing and this is an answer to a query, send 894 * an empty buffer. 895 */ 896 if (ws.npackets == 0 && (ws.state & WS_ST_QUERY)) { 897 supply_write(&v2buf); 898 if (ws.npackets == 0) 899 supply_write(&v12buf); 900 } 901 } 902 903 904 /* 905 * send all of the routing table or just do a flash update 906 */ 907 void 908 rip_bcast(int flash) 909 { 910 static struct sockaddr_in dst = {AF_INET}; 911 struct interface *ifp; 912 enum output_type type; 913 int vers; 914 struct timeval rtime; 915 916 917 need_flash = _B_FALSE; 918 intvl_random(&rtime, MIN_WAITTIME, MAX_WAITTIME); 919 no_flash = rtime; 920 timevaladd(&no_flash, &now); 921 922 if (!rip_enabled) 923 return; 924 925 trace_act("send %s and inhibit dynamic updates for %.3f sec", 926 flash ? "dynamic update" : "all routes", 927 rtime.tv_sec + ((double)rtime.tv_usec)/1000000.0); 928 929 for (ifp = ifnet; ifp != NULL; ifp = ifp->int_next) { 930 /* 931 * Skip interfaces not doing RIP or for which IP 932 * forwarding isn't turned on. Skip duplicate 933 * interfaces, we don't want to generate duplicate 934 * packets. Do try broken interfaces to see if they 935 * have healed. 936 */ 937 if (IS_RIP_OUT_OFF(ifp->int_state) || 938 (ifp->int_state & IS_DUP) || 939 !IS_IFF_ROUTING(ifp->int_if_flags)) 940 continue; 941 942 /* skip turned off interfaces */ 943 if (!IS_IFF_UP(ifp->int_if_flags)) 944 continue; 945 946 /* skip interfaces we shouldn't use */ 947 if (IS_IFF_QUIET(ifp->int_if_flags)) 948 continue; 949 950 vers = (ifp->int_state & IS_NO_RIPV1_OUT) ? RIPv2 : RIPv1; 951 dst.sin_addr.s_addr = ifp->int_ripout_addr; 952 953 /* 954 * Ignore the interface if it's not broadcast, 955 * point-to-point, or remote. It must be non-broadcast 956 * multiaccess, and therefore unsupported. 957 */ 958 if (!(ifp->int_if_flags & (IFF_BROADCAST | IFF_POINTOPOINT)) && 959 !(ifp->int_state & IS_REMOTE)) 960 continue; 961 962 type = (ifp->int_if_flags & IFF_BROADCAST) ? 963 OUT_BROADCAST : OUT_UNICAST; 964 if (vers == RIPv2 && (ifp->int_if_flags & IFF_MULTICAST) && 965 !(ifp->int_state & IS_NO_RIP_MCAST)) 966 type = OUT_MULTICAST; 967 968 supply(&dst, ifp, type, flash, vers, _B_TRUE); 969 } 970 971 update_seqno++; /* all routes are up to date */ 972 } 973 974 975 /* 976 * Ask for routes 977 * Do it only once to an interface, and not even after the interface 978 * was broken and recovered. 979 */ 980 void 981 rip_query(void) 982 { 983 static struct sockaddr_in dst = {AF_INET}; 984 struct interface *ifp; 985 struct rip buf; 986 enum output_type type; 987 988 989 if (!rip_enabled) 990 return; 991 992 (void) memset(&buf, 0, sizeof (buf)); 993 994 for (ifp = ifnet; ifp; ifp = ifp->int_next) { 995 /* 996 * Skip interfaces those already queried. Do not ask 997 * via interfaces through which we don't accept input. 998 * Do not ask via interfaces that cannot send RIP 999 * packets. Don't send queries on duplicate 1000 * interfaces, that would generate duplicate packets 1001 * on link. Do try broken interfaces to see if they 1002 * have healed. 1003 */ 1004 if (IS_RIP_IN_OFF(ifp->int_state) || 1005 (ifp->int_state & IS_DUP) || 1006 ifp->int_query_time != NEVER) 1007 continue; 1008 1009 /* skip turned off interfaces */ 1010 if (!IS_IFF_UP(ifp->int_if_flags)) 1011 continue; 1012 1013 /* skip interfaces we shouldn't use */ 1014 if (IS_IFF_QUIET(ifp->int_if_flags)) 1015 continue; 1016 1017 /* 1018 * Ignore the interface if it's not broadcast, 1019 * point-to-point, or remote. It must be non-broadcast 1020 * multiaccess, and therefore unsupported. 1021 */ 1022 if (!(ifp->int_if_flags & (IFF_BROADCAST | IFF_POINTOPOINT)) && 1023 !(ifp->int_state & IS_REMOTE)) 1024 continue; 1025 1026 buf.rip_cmd = RIPCMD_REQUEST; 1027 buf.rip_nets[0].n_family = RIP_AF_UNSPEC; 1028 buf.rip_nets[0].n_metric = htonl(HOPCNT_INFINITY); 1029 1030 /* 1031 * Send a RIPv1 query only if allowed and if we will 1032 * listen to RIPv1 routers. 1033 */ 1034 if ((ifp->int_state & IS_NO_RIPV1_OUT) || 1035 (ifp->int_state & IS_NO_RIPV1_IN)) { 1036 buf.rip_vers = RIPv2; 1037 } else { 1038 buf.rip_vers = RIPv1; 1039 } 1040 1041 dst.sin_addr.s_addr = ifp->int_ripout_addr; 1042 1043 type = (ifp->int_if_flags & IFF_BROADCAST) ? 1044 OUT_BROADCAST : OUT_UNICAST; 1045 if (buf.rip_vers == RIPv2 && 1046 (ifp->int_if_flags & IFF_MULTICAST) && 1047 !(ifp->int_state & IS_NO_RIP_MCAST)) 1048 type = OUT_MULTICAST; 1049 1050 ifp->int_query_time = now.tv_sec+SUPPLY_INTERVAL; 1051 if (output(type, &dst, ifp, &buf, sizeof (buf)) < 0) 1052 if_sick(ifp, _B_FALSE); 1053 } 1054 } 1055