1 /* 2 * Copyright (c) 1983, 1988, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #if !defined(lint) && !defined(sgi) && !defined(__NetBSD__) 35 static char sccsid[] = "@(#)tables.c 8.1 (Berkeley) 6/5/93"; 36 #elif defined(__NetBSD__) 37 static char rcsid[] = "$NetBSD$"; 38 #endif 39 40 #include "defs.h" 41 42 static struct rt_spare *rts_better(struct rt_entry *); 43 44 struct radix_node_head *rhead; /* root of the radix tree */ 45 46 int need_flash = 1; /* flash update needed 47 * start =1 to suppress the 1st 48 */ 49 50 struct timeval age_timer; /* next check of old routes */ 51 struct timeval need_kern = { /* need to update kernel table */ 52 EPOCH+MIN_WAITTIME-1 53 }; 54 55 int stopint; 56 57 int total_routes; 58 59 /* zap any old routes through this gateway */ 60 naddr age_bad_gate; 61 62 63 /* It is desirable to "aggregate" routes, to combine differing routes of 64 * the same metric and next hop into a common route with a smaller netmask 65 * or to suppress redundant routes, routes that add no information to 66 * routes with smaller netmasks. 67 * 68 * A route is redundant if and only if any and all routes with smaller 69 * but matching netmasks and nets are the same. Since routes are 70 * kept sorted in the radix tree, redundant routes always come second. 71 * 72 * There are two kinds of aggregations. First, two routes of the same bit 73 * mask and differing only in the least significant bit of the network 74 * number can be combined into a single route with a coarser mask. 75 * 76 * Second, a route can be suppressed in favor of another route with a more 77 * coarse mask provided no incompatible routes with intermediate masks 78 * are present. The second kind of aggregation involves suppressing routes. 79 * A route must not be suppressed if an incompatible route exists with 80 * an intermediate mask, since the suppressed route would be covered 81 * by the intermediate. 82 * 83 * This code relies on the radix tree walk encountering routes 84 * sorted first by address, with the smallest address first. 85 */ 86 87 struct ag_info ag_slots[NUM_AG_SLOTS], *ag_avail, *ag_corsest, *ag_finest; 88 89 /* #define DEBUG_AG */ 90 #ifdef DEBUG_AG 91 #define CHECK_AG() {int acnt = 0; struct ag_info *cag; \ 92 for (cag = ag_avail; cag != 0; cag = cag->ag_fine) \ 93 acnt++; \ 94 for (cag = ag_corsest; cag != 0; cag = cag->ag_fine) \ 95 acnt++; \ 96 if (acnt != NUM_AG_SLOTS) { \ 97 (void)fflush(stderr); \ 98 abort(); \ 99 } \ 100 } 101 #else 102 #define CHECK_AG() 103 #endif 104 105 106 /* Output the contents of an aggregation table slot. 107 * This function must always be immediately followed with the deletion 108 * of the target slot. 109 */ 110 static void 111 ag_out(struct ag_info *ag, 112 void (*out)(struct ag_info *)) 113 { 114 struct ag_info *ag_cors; 115 naddr bit; 116 117 118 /* If we output both the even and odd twins, then the immediate parent, 119 * if it is present, is redundant, unless the parent manages to 120 * aggregate into something coarser. 121 * On successive calls, this code detects the even and odd twins, 122 * and marks the parent. 123 * 124 * Note that the order in which the radix tree code emits routes 125 * ensures that the twins are seen before the parent is emitted. 126 */ 127 ag_cors = ag->ag_cors; 128 if (ag_cors != 0 129 && ag_cors->ag_mask == ag->ag_mask<<1 130 && ag_cors->ag_dst_h == (ag->ag_dst_h & ag_cors->ag_mask)) { 131 ag_cors->ag_state |= ((ag_cors->ag_dst_h == ag->ag_dst_h) 132 ? AGS_REDUN0 133 : AGS_REDUN1); 134 } 135 136 /* Skip it if this route is itself redundant. 137 * 138 * It is ok to change the contents of the slot here, since it is 139 * always deleted next. 140 */ 141 if (ag->ag_state & AGS_REDUN0) { 142 if (ag->ag_state & AGS_REDUN1) 143 return; 144 bit = (-ag->ag_mask) >> 1; 145 ag->ag_dst_h |= bit; 146 ag->ag_mask |= bit; 147 148 } else if (ag->ag_state & AGS_REDUN1) { 149 bit = (-ag->ag_mask) >> 1; 150 ag->ag_mask |= bit; 151 } 152 out(ag); 153 } 154 155 156 static void 157 ag_del(struct ag_info *ag) 158 { 159 CHECK_AG(); 160 161 if (ag->ag_cors == 0) 162 ag_corsest = ag->ag_fine; 163 else 164 ag->ag_cors->ag_fine = ag->ag_fine; 165 166 if (ag->ag_fine == 0) 167 ag_finest = ag->ag_cors; 168 else 169 ag->ag_fine->ag_cors = ag->ag_cors; 170 171 ag->ag_fine = ag_avail; 172 ag_avail = ag; 173 174 CHECK_AG(); 175 } 176 177 178 /* Flush routes waiting for aggretation. 179 * This must not suppress a route unless it is known that among all 180 * routes with coarser masks that match it, the one with the longest 181 * mask is appropriate. This is ensured by scanning the routes 182 * in lexical order, and with the most restritive mask first 183 * among routes to the same destination. 184 */ 185 void 186 ag_flush(naddr lim_dst_h, /* flush routes to here */ 187 naddr lim_mask, /* matching this mask */ 188 void (*out)(struct ag_info *)) 189 { 190 struct ag_info *ag, *ag_cors; 191 naddr dst_h; 192 193 194 for (ag = ag_finest; 195 ag != 0 && ag->ag_mask >= lim_mask; 196 ag = ag_cors) { 197 ag_cors = ag->ag_cors; 198 199 /* work on only the specified routes */ 200 dst_h = ag->ag_dst_h; 201 if ((dst_h & lim_mask) != lim_dst_h) 202 continue; 203 204 if (!(ag->ag_state & AGS_SUPPRESS)) 205 ag_out(ag, out); 206 207 else for ( ; ; ag_cors = ag_cors->ag_cors) { 208 /* Look for a route that can suppress the 209 * current route */ 210 if (ag_cors == 0) { 211 /* failed, so output it and look for 212 * another route to work on 213 */ 214 ag_out(ag, out); 215 break; 216 } 217 218 if ((dst_h & ag_cors->ag_mask) == ag_cors->ag_dst_h) { 219 /* We found a route with a coarser mask that 220 * aggregates the current target. 221 * 222 * If it has a different next hop, it 223 * cannot replace the target, so output 224 * the target. 225 */ 226 if (ag->ag_gate != ag_cors->ag_gate 227 && !(ag->ag_state & AGS_FINE_GATE) 228 && !(ag_cors->ag_state & AGS_CORS_GATE)) { 229 ag_out(ag, out); 230 break; 231 } 232 233 /* If the coarse route has a good enough 234 * metric, it suppresses the target. 235 */ 236 if (ag_cors->ag_pref <= ag->ag_pref) { 237 if (ag_cors->ag_seqno > ag->ag_seqno) 238 ag_cors->ag_seqno = ag->ag_seqno; 239 if (AG_IS_REDUN(ag->ag_state) 240 && ag_cors->ag_mask==ag->ag_mask<<1) { 241 if (ag_cors->ag_dst_h == dst_h) 242 ag_cors->ag_state |= AGS_REDUN0; 243 else 244 ag_cors->ag_state |= AGS_REDUN1; 245 } 246 if (ag->ag_tag != ag_cors->ag_tag) 247 ag_cors->ag_tag = 0; 248 if (ag->ag_nhop != ag_cors->ag_nhop) 249 ag_cors->ag_nhop = 0; 250 break; 251 } 252 } 253 } 254 255 /* That route has either been output or suppressed */ 256 ag_cors = ag->ag_cors; 257 ag_del(ag); 258 } 259 260 CHECK_AG(); 261 } 262 263 264 /* Try to aggregate a route with previous routes. 265 */ 266 void 267 ag_check(naddr dst, 268 naddr mask, 269 naddr gate, 270 naddr nhop, 271 char metric, 272 char pref, 273 u_int seqno, 274 u_short tag, 275 u_short state, 276 void (*out)(struct ag_info *)) /* output using this */ 277 { 278 struct ag_info *ag, *nag, *ag_cors; 279 naddr xaddr; 280 int x; 281 282 NTOHL(dst); 283 284 /* Punt non-contiguous subnet masks. 285 * 286 * (X & -X) contains a single bit if and only if X is a power of 2. 287 * (X + (X & -X)) == 0 if and only if X is a power of 2. 288 */ 289 if ((mask & -mask) + mask != 0) { 290 struct ag_info nc_ag; 291 292 nc_ag.ag_dst_h = dst; 293 nc_ag.ag_mask = mask; 294 nc_ag.ag_gate = gate; 295 nc_ag.ag_nhop = nhop; 296 nc_ag.ag_metric = metric; 297 nc_ag.ag_pref = pref; 298 nc_ag.ag_tag = tag; 299 nc_ag.ag_state = state; 300 nc_ag.ag_seqno = seqno; 301 out(&nc_ag); 302 return; 303 } 304 305 /* Search for the right slot in the aggregation table. 306 */ 307 ag_cors = 0; 308 ag = ag_corsest; 309 while (ag != 0) { 310 if (ag->ag_mask >= mask) 311 break; 312 313 /* Suppress old routes (i.e. combine with compatible routes 314 * with coarser masks) as we look for the right slot in the 315 * aggregation table for the new route. 316 * A route to an address less than the current destination 317 * will not be affected by the current route or any route 318 * seen hereafter. That means it is safe to suppress it. 319 * This check keeps poor routes (eg. with large hop counts) 320 * from preventing suppresion of finer routes. 321 */ 322 if (ag_cors != 0 323 && ag->ag_dst_h < dst 324 && (ag->ag_state & AGS_SUPPRESS) 325 && ag_cors->ag_pref <= ag->ag_pref 326 && (ag->ag_dst_h & ag_cors->ag_mask) == ag_cors->ag_dst_h 327 && (ag_cors->ag_gate == ag->ag_gate 328 || (ag->ag_state & AGS_FINE_GATE) 329 || (ag_cors->ag_state & AGS_CORS_GATE))) { 330 if (ag_cors->ag_seqno > ag->ag_seqno) 331 ag_cors->ag_seqno = ag->ag_seqno; 332 if (AG_IS_REDUN(ag->ag_state) 333 && ag_cors->ag_mask==ag->ag_mask<<1) { 334 if (ag_cors->ag_dst_h == dst) 335 ag_cors->ag_state |= AGS_REDUN0; 336 else 337 ag_cors->ag_state |= AGS_REDUN1; 338 } 339 if (ag->ag_tag != ag_cors->ag_tag) 340 ag_cors->ag_tag = 0; 341 if (ag->ag_nhop != ag_cors->ag_nhop) 342 ag_cors->ag_nhop = 0; 343 ag_del(ag); 344 CHECK_AG(); 345 } else { 346 ag_cors = ag; 347 } 348 ag = ag_cors->ag_fine; 349 } 350 351 /* If we find the even/odd twin of the new route, and if the 352 * masks and so forth are equal, we can aggregate them. 353 * We can probably promote one of the pair. 354 * 355 * Since the routes are encountered in lexical order, 356 * the new route must be odd. However, the second or later 357 * times around this loop, it could be the even twin promoted 358 * from the even/odd pair of twins of the finer route. 359 */ 360 while (ag != 0 361 && ag->ag_mask == mask 362 && ((ag->ag_dst_h ^ dst) & (mask<<1)) == 0) { 363 364 /* Here we know the target route and the route in the current 365 * slot have the same netmasks and differ by at most the 366 * last bit. They are either for the same destination, or 367 * for an even/odd pair of destinations. 368 */ 369 if (ag->ag_dst_h == dst) { 370 /* We have two routes to the same destination. 371 * Routes are encountered in lexical order, so a 372 * route is never promoted until the parent route is 373 * already present. So we know that the new route is 374 * a promoted pair and the route already in the slot 375 * is the explicit route. 376 * 377 * Prefer the best route if their metrics differ, 378 * or the promoted one if not, following a sort 379 * of longest-match rule. 380 */ 381 if (pref <= ag->ag_pref) { 382 ag->ag_gate = gate; 383 ag->ag_nhop = nhop; 384 ag->ag_tag = tag; 385 ag->ag_metric = metric; 386 ag->ag_pref = pref; 387 x = ag->ag_state; 388 ag->ag_state = state; 389 state = x; 390 } 391 392 /* The sequence number controls flash updating, 393 * and should be the smaller of the two. 394 */ 395 if (ag->ag_seqno > seqno) 396 ag->ag_seqno = seqno; 397 398 /* some bits are set if they are set on either route */ 399 ag->ag_state |= (state & (AGS_PROMOTE_EITHER 400 | AGS_REDUN0 | AGS_REDUN1)); 401 return; 402 } 403 404 /* If one of the routes can be promoted and the other can 405 * be suppressed, it may be possible to combine them or 406 * worthwhile to promote one. 407 * 408 * Note that any route that can be promoted is always 409 * marked to be eligible to be suppressed. 410 */ 411 if (!((state & AGS_PROMOTE) 412 && (ag->ag_state & AGS_SUPPRESS)) 413 && !((ag->ag_state & AGS_PROMOTE) 414 && (state & AGS_SUPPRESS))) 415 break; 416 417 /* A pair of even/odd twin routes can be combined 418 * if either is redundant, or if they are via the 419 * same gateway and have the same metric. 420 */ 421 if (AG_IS_REDUN(ag->ag_state) 422 || AG_IS_REDUN(state) 423 || (ag->ag_gate == gate 424 && ag->ag_pref == pref 425 && (state & ag->ag_state & AGS_PROMOTE) != 0)) { 426 427 /* We have both the even and odd pairs. 428 * Since the routes are encountered in order, 429 * the route in the slot must be the even twin. 430 * 431 * Combine and promote the pair of routes. 432 */ 433 if (seqno > ag->ag_seqno) 434 seqno = ag->ag_seqno; 435 if (!AG_IS_REDUN(state)) 436 state &= ~AGS_REDUN1; 437 if (AG_IS_REDUN(ag->ag_state)) 438 state |= AGS_REDUN0; 439 else 440 state &= ~AGS_REDUN0; 441 state |= (ag->ag_state & AGS_PROMOTE_EITHER); 442 if (ag->ag_tag != tag) 443 tag = 0; 444 if (ag->ag_nhop != nhop) 445 nhop = 0; 446 447 /* Get rid of the even twin that was already 448 * in the slot. 449 */ 450 ag_del(ag); 451 452 } else if (ag->ag_pref >= pref 453 && (ag->ag_state & AGS_PROMOTE)) { 454 /* If we cannot combine the pair, maybe the route 455 * with the worse metric can be promoted. 456 * 457 * Promote the old, even twin, by giving its slot 458 * in the table to the new, odd twin. 459 */ 460 ag->ag_dst_h = dst; 461 462 xaddr = ag->ag_gate; 463 ag->ag_gate = gate; 464 gate = xaddr; 465 466 xaddr = ag->ag_nhop; 467 ag->ag_nhop = nhop; 468 nhop = xaddr; 469 470 x = ag->ag_tag; 471 ag->ag_tag = tag; 472 tag = x; 473 474 x = ag->ag_state; 475 ag->ag_state = state; 476 state = x; 477 if (!AG_IS_REDUN(state)) 478 state &= ~AGS_REDUN0; 479 480 x = ag->ag_metric; 481 ag->ag_metric = metric; 482 metric = x; 483 484 x = ag->ag_pref; 485 ag->ag_pref = pref; 486 pref = x; 487 488 if (seqno >= ag->ag_seqno) 489 seqno = ag->ag_seqno; 490 else 491 ag->ag_seqno = seqno; 492 493 } else { 494 if (!(state & AGS_PROMOTE)) 495 break; /* cannot promote either twin */ 496 497 /* promote the new, odd twin by shaving its 498 * mask and address. 499 */ 500 if (seqno > ag->ag_seqno) 501 seqno = ag->ag_seqno; 502 else 503 ag->ag_seqno = seqno; 504 if (!AG_IS_REDUN(state)) 505 state &= ~AGS_REDUN1; 506 } 507 508 mask <<= 1; 509 dst &= mask; 510 511 if (ag_cors == 0) { 512 ag = ag_corsest; 513 break; 514 } 515 ag = ag_cors; 516 ag_cors = ag->ag_cors; 517 } 518 519 /* When we can no longer promote and combine routes, 520 * flush the old route in the target slot. Also flush 521 * any finer routes that we know will never be aggregated by 522 * the new route. 523 * 524 * In case we moved toward coarser masks, 525 * get back where we belong 526 */ 527 if (ag != 0 528 && ag->ag_mask < mask) { 529 ag_cors = ag; 530 ag = ag->ag_fine; 531 } 532 533 /* Empty the target slot 534 */ 535 if (ag != 0 && ag->ag_mask == mask) { 536 ag_flush(ag->ag_dst_h, ag->ag_mask, out); 537 ag = (ag_cors == 0) ? ag_corsest : ag_cors->ag_fine; 538 } 539 540 #ifdef DEBUG_AG 541 (void)fflush(stderr); 542 if (ag == 0 && ag_cors != ag_finest) 543 abort(); 544 if (ag_cors == 0 && ag != ag_corsest) 545 abort(); 546 if (ag != 0 && ag->ag_cors != ag_cors) 547 abort(); 548 if (ag_cors != 0 && ag_cors->ag_fine != ag) 549 abort(); 550 CHECK_AG(); 551 #endif 552 553 /* Save the new route on the end of the table. 554 */ 555 nag = ag_avail; 556 ag_avail = nag->ag_fine; 557 558 nag->ag_dst_h = dst; 559 nag->ag_mask = mask; 560 nag->ag_gate = gate; 561 nag->ag_nhop = nhop; 562 nag->ag_metric = metric; 563 nag->ag_pref = pref; 564 nag->ag_tag = tag; 565 nag->ag_state = state; 566 nag->ag_seqno = seqno; 567 568 nag->ag_fine = ag; 569 if (ag != 0) 570 ag->ag_cors = nag; 571 else 572 ag_finest = nag; 573 nag->ag_cors = ag_cors; 574 if (ag_cors == 0) 575 ag_corsest = nag; 576 else 577 ag_cors->ag_fine = nag; 578 CHECK_AG(); 579 } 580 581 582 static char * 583 rtm_type_name(u_char type) 584 { 585 static char *rtm_types[] = { 586 "RTM_ADD", 587 "RTM_DELETE", 588 "RTM_CHANGE", 589 "RTM_GET", 590 "RTM_LOSING", 591 "RTM_REDIRECT", 592 "RTM_MISS", 593 "RTM_LOCK", 594 "RTM_OLDADD", 595 "RTM_OLDDEL", 596 "RTM_RESOLVE", 597 "RTM_NEWADDR", 598 "RTM_DELADDR", 599 "RTM_IFINFO" 600 }; 601 static char name0[10]; 602 603 604 if (type > sizeof(rtm_types)/sizeof(rtm_types[0]) 605 || type == 0) { 606 sprintf(name0, "RTM type %#x", type); 607 return name0; 608 } else { 609 return rtm_types[type-1]; 610 } 611 } 612 613 614 /* Trim a mask in a sockaddr 615 * Produce a length of 0 for an address of 0. 616 * Otherwise produce the index of the first zero byte. 617 */ 618 void 619 #ifdef _HAVE_SIN_LEN 620 masktrim(struct sockaddr_in *ap) 621 #else 622 masktrim(struct sockaddr_in_new *ap) 623 #endif 624 { 625 register char *cp; 626 627 if (ap->sin_addr.s_addr == 0) { 628 ap->sin_len = 0; 629 return; 630 } 631 cp = (char *)(&ap->sin_addr.s_addr+1); 632 while (*--cp == 0) 633 continue; 634 ap->sin_len = cp - (char*)ap + 1; 635 } 636 637 638 /* Tell the kernel to add, delete or change a route 639 */ 640 static void 641 rtioctl(int action, /* RTM_DELETE, etc */ 642 naddr dst, 643 naddr gate, 644 naddr mask, 645 int metric, 646 int flags) 647 { 648 struct { 649 struct rt_msghdr w_rtm; 650 struct sockaddr_in w_dst; 651 struct sockaddr_in w_gate; 652 #ifdef _HAVE_SA_LEN 653 struct sockaddr_in w_mask; 654 #else 655 struct sockaddr_in_new w_mask; 656 #endif 657 } w; 658 long cc; 659 660 again: 661 bzero(&w, sizeof(w)); 662 w.w_rtm.rtm_msglen = sizeof(w); 663 w.w_rtm.rtm_version = RTM_VERSION; 664 w.w_rtm.rtm_type = action; 665 w.w_rtm.rtm_flags = flags; 666 w.w_rtm.rtm_seq = ++rt_sock_seqno; 667 w.w_rtm.rtm_addrs = RTA_DST|RTA_GATEWAY; 668 if (metric != 0) { 669 w.w_rtm.rtm_rmx.rmx_hopcount = metric; 670 w.w_rtm.rtm_inits |= RTV_HOPCOUNT; 671 } 672 w.w_dst.sin_family = AF_INET; 673 w.w_dst.sin_addr.s_addr = dst; 674 w.w_gate.sin_family = AF_INET; 675 w.w_gate.sin_addr.s_addr = gate; 676 #ifdef _HAVE_SA_LEN 677 w.w_dst.sin_len = sizeof(w.w_dst); 678 w.w_gate.sin_len = sizeof(w.w_gate); 679 #endif 680 if (mask == HOST_MASK) { 681 w.w_rtm.rtm_flags |= RTF_HOST; 682 w.w_rtm.rtm_msglen -= sizeof(w.w_mask); 683 } else { 684 w.w_rtm.rtm_addrs |= RTA_NETMASK; 685 w.w_mask.sin_addr.s_addr = htonl(mask); 686 #ifdef _HAVE_SA_LEN 687 masktrim(&w.w_mask); 688 if (w.w_mask.sin_len == 0) 689 w.w_mask.sin_len = sizeof(long); 690 w.w_rtm.rtm_msglen -= (sizeof(w.w_mask) - w.w_mask.sin_len); 691 #endif 692 } 693 694 if (TRACEKERNEL) 695 trace_kernel("write kernel %s %s->%s metric=%d flags=%#x\n", 696 rtm_type_name(action), 697 addrname(dst, mask, 0), naddr_ntoa(gate), 698 metric, flags); 699 700 #ifndef NO_INSTALL 701 cc = write(rt_sock, &w, w.w_rtm.rtm_msglen); 702 if (cc == w.w_rtm.rtm_msglen) 703 return; 704 if (cc < 0) { 705 if (errno == ESRCH 706 && (action == RTM_CHANGE || action == RTM_DELETE)) { 707 trace_act("route to %s disappeared before %s", 708 addrname(dst, mask, 0), 709 rtm_type_name(action)); 710 if (action == RTM_CHANGE) { 711 action = RTM_ADD; 712 goto again; 713 } 714 return; 715 } 716 msglog("write(rt_sock) %s %s --> %s: %s", 717 rtm_type_name(action), 718 addrname(dst, mask, 0), naddr_ntoa(gate), 719 strerror(errno)); 720 } else { 721 msglog("write(rt_sock) wrote %d instead of %d", 722 cc, w.w_rtm.rtm_msglen); 723 } 724 #endif 725 } 726 727 728 #define KHASH_SIZE 71 /* should be prime */ 729 #define KHASH(a,m) khash_bins[((a) ^ (m)) % KHASH_SIZE] 730 static struct khash { 731 struct khash *k_next; 732 naddr k_dst; 733 naddr k_mask; 734 naddr k_gate; 735 short k_metric; 736 u_short k_state; 737 #define KS_NEW 0x001 738 #define KS_DELETE 0x002 739 #define KS_ADD 0x004 /* add to the kernel */ 740 #define KS_CHANGE 0x008 /* tell kernel to change the route */ 741 #define KS_DEL_ADD 0x010 /* delete & add to change the kernel */ 742 #define KS_STATIC 0x020 /* Static flag in kernel */ 743 #define KS_GATEWAY 0x040 /* G flag in kernel */ 744 #define KS_DYNAMIC 0x080 /* result of redirect */ 745 #define KS_DELETED 0x100 /* already deleted */ 746 time_t k_keep; 747 #define K_KEEP_LIM 30 748 time_t k_redirect_time; /* when redirected route 1st seen */ 749 } *khash_bins[KHASH_SIZE]; 750 751 752 static struct khash* 753 kern_find(naddr dst, naddr mask, struct khash ***ppk) 754 { 755 struct khash *k, **pk; 756 757 for (pk = &KHASH(dst,mask); (k = *pk) != 0; pk = &k->k_next) { 758 if (k->k_dst == dst && k->k_mask == mask) 759 break; 760 } 761 if (ppk != 0) 762 *ppk = pk; 763 return k; 764 } 765 766 767 static struct khash* 768 kern_add(naddr dst, naddr mask) 769 { 770 struct khash *k, **pk; 771 772 k = kern_find(dst, mask, &pk); 773 if (k != 0) 774 return k; 775 776 k = (struct khash *)malloc(sizeof(*k)); 777 778 bzero(k, sizeof(*k)); 779 k->k_dst = dst; 780 k->k_mask = mask; 781 k->k_state = KS_NEW; 782 k->k_keep = now.tv_sec; 783 *pk = k; 784 785 return k; 786 } 787 788 789 /* If a kernel route has a non-zero metric, check that it is still in the 790 * daemon table, and not deleted by interfaces coming and going. 791 */ 792 static void 793 kern_check_static(struct khash *k, 794 struct interface *ifp) 795 { 796 struct rt_entry *rt; 797 naddr int_addr; 798 799 if (k->k_metric == 0) 800 return; 801 802 int_addr = (ifp != 0) ? ifp->int_addr : loopaddr; 803 804 rt = rtget(k->k_dst, k->k_mask); 805 if (rt != 0) { 806 if (!(rt->rt_state & RS_STATIC)) 807 rtchange(rt, rt->rt_state | RS_STATIC, 808 k->k_gate, int_addr, 809 k->k_metric, 0, ifp, now.tv_sec, 0); 810 } else { 811 rtadd(k->k_dst, k->k_mask, k->k_gate, int_addr, 812 k->k_metric, 0, RS_STATIC, ifp); 813 } 814 } 815 816 817 /* add a route the kernel told us 818 */ 819 static void 820 rtm_add(struct rt_msghdr *rtm, 821 struct rt_addrinfo *info, 822 time_t keep) 823 { 824 struct khash *k; 825 struct interface *ifp; 826 naddr mask; 827 828 829 if (rtm->rtm_flags & RTF_HOST) { 830 mask = HOST_MASK; 831 } else if (INFO_MASK(info) != 0) { 832 mask = ntohl(S_ADDR(INFO_MASK(info))); 833 } else { 834 msglog("ignore %s without mask", rtm_type_name(rtm->rtm_type)); 835 return; 836 } 837 838 if (INFO_GATE(info) == 0 839 || INFO_GATE(info)->sa_family != AF_INET) { 840 msglog("ignore %s without gateway", 841 rtm_type_name(rtm->rtm_type)); 842 return; 843 } 844 845 k = kern_add(S_ADDR(INFO_DST(info)), mask); 846 if (k->k_state & KS_NEW) 847 k->k_keep = now.tv_sec+keep; 848 k->k_gate = S_ADDR(INFO_GATE(info)); 849 k->k_metric = rtm->rtm_rmx.rmx_hopcount; 850 if (k->k_metric < 0) 851 k->k_metric = 0; 852 else if (k->k_metric > HOPCNT_INFINITY) 853 k->k_metric = HOPCNT_INFINITY; 854 k->k_state &= ~(KS_DELETED | KS_GATEWAY | KS_STATIC | KS_NEW); 855 if (rtm->rtm_flags & RTF_GATEWAY) 856 k->k_state |= KS_GATEWAY; 857 if (rtm->rtm_flags & RTF_STATIC) 858 k->k_state |= KS_STATIC; 859 860 if (0 != (rtm->rtm_flags & (RTF_DYNAMIC | RTF_MODIFIED))) { 861 if (INFO_AUTHOR(info) != 0 862 && INFO_AUTHOR(info)->sa_family == AF_INET) 863 ifp = iflookup(S_ADDR(INFO_AUTHOR(info))); 864 else 865 ifp = 0; 866 if (supplier 867 && (ifp == 0 || !(ifp->int_state & IS_REDIRECT_OK))) { 868 /* Routers are not supposed to listen to redirects, 869 * so delete it if it came via an unknown interface 870 * or the interface does not have special permission. 871 */ 872 k->k_state &= ~KS_DYNAMIC; 873 k->k_state |= KS_DELETE; 874 LIM_SEC(need_kern, 0); 875 trace_act("mark for deletion redirected %s --> %s" 876 " via %s", 877 addrname(k->k_dst, k->k_mask, 0), 878 naddr_ntoa(k->k_gate), 879 ifp ? ifp->int_name : "unknown interface"); 880 } else { 881 k->k_state |= KS_DYNAMIC; 882 k->k_redirect_time = now.tv_sec; 883 trace_act("accept redirected %s --> %s via %s", 884 addrname(k->k_dst, k->k_mask, 0), 885 naddr_ntoa(k->k_gate), 886 ifp ? ifp->int_name : "unknown interface"); 887 } 888 return; 889 } 890 891 /* If it is not a static route, quit until the next comparison 892 * between the kernel and daemon tables, when it will be deleted. 893 */ 894 if (!(k->k_state & KS_STATIC)) { 895 k->k_state |= KS_DELETE; 896 LIM_SEC(need_kern, k->k_keep); 897 return; 898 } 899 900 /* Put static routes with real metrics into the daemon table so 901 * they can be advertised. 902 * 903 * Find the interface toward the gateway. 904 */ 905 ifp = iflookup(k->k_gate); 906 if (ifp == 0) 907 msglog("static route %s --> %s impossibly lacks ifp", 908 addrname(S_ADDR(INFO_DST(info)), mask, 0), 909 naddr_ntoa(k->k_gate)); 910 911 kern_check_static(k, ifp); 912 } 913 914 915 /* deal with packet loss 916 */ 917 static void 918 rtm_lose(struct rt_msghdr *rtm, 919 struct rt_addrinfo *info) 920 { 921 if (INFO_GATE(info) == 0 922 || INFO_GATE(info)->sa_family != AF_INET) { 923 trace_act("ignore %s without gateway", 924 rtm_type_name(rtm->rtm_type)); 925 return; 926 } 927 928 if (!supplier) 929 rdisc_age(S_ADDR(INFO_GATE(info))); 930 931 age(S_ADDR(INFO_GATE(info))); 932 } 933 934 935 /* Clean the kernel table by copying it to the daemon image. 936 * Eventually the daemon will delete any extra routes. 937 */ 938 void 939 flush_kern(void) 940 { 941 size_t needed; 942 int mib[6]; 943 char *buf, *next, *lim; 944 struct rt_msghdr *rtm; 945 struct interface *ifp; 946 static struct sockaddr_in gate_sa; 947 struct rt_addrinfo info; 948 949 950 mib[0] = CTL_NET; 951 mib[1] = PF_ROUTE; 952 mib[2] = 0; /* protocol */ 953 mib[3] = 0; /* wildcard address family */ 954 mib[4] = NET_RT_DUMP; 955 mib[5] = 0; /* no flags */ 956 if (sysctl(mib, 6, 0, &needed, 0, 0) < 0) { 957 DBGERR(1,"RT_DUMP-sysctl-estimate"); 958 return; 959 } 960 buf = malloc(needed); 961 if (sysctl(mib, 6, buf, &needed, 0, 0) < 0) 962 BADERR(1,"RT_DUMP"); 963 lim = buf + needed; 964 for (next = buf; next < lim; next += rtm->rtm_msglen) { 965 rtm = (struct rt_msghdr *)next; 966 967 rt_xaddrs(&info, 968 (struct sockaddr *)(rtm+1), 969 (struct sockaddr *)(next + rtm->rtm_msglen), 970 rtm->rtm_addrs); 971 972 if (INFO_DST(&info) == 0 973 || INFO_DST(&info)->sa_family != AF_INET) 974 continue; 975 976 /* ignore ARP table entries on systems with a merged route 977 * and ARP table. 978 */ 979 if (rtm->rtm_flags & RTF_LLINFO) 980 continue; 981 982 if (INFO_GATE(&info) == 0) 983 continue; 984 if (INFO_GATE(&info)->sa_family != AF_INET) { 985 if (INFO_GATE(&info)->sa_family != AF_LINK) 986 continue; 987 ifp = ifwithindex(((struct sockaddr_dl *) 988 INFO_GATE(&info))->sdl_index); 989 if (ifp == 0) 990 continue; 991 if ((ifp->int_if_flags & IFF_POINTOPOINT) 992 || S_ADDR(INFO_DST(&info)) == ifp->int_addr) 993 gate_sa.sin_addr.s_addr = ifp->int_addr; 994 else 995 gate_sa.sin_addr.s_addr = htonl(ifp->int_net); 996 #ifdef _HAVE_SA_LEN 997 gate_sa.sin_len = sizeof(gate_sa); 998 #endif 999 gate_sa.sin_family = AF_INET; 1000 INFO_GATE(&info) = (struct sockaddr *)&gate_sa; 1001 } 1002 1003 /* ignore multicast addresses 1004 */ 1005 if (IN_MULTICAST(ntohl(S_ADDR(INFO_DST(&info))))) 1006 continue; 1007 1008 /* Note static routes and interface routes, and also 1009 * preload the image of the kernel table so that 1010 * we can later clean it, as well as avoid making 1011 * unneeded changes. Keep the old kernel routes for a 1012 * few seconds to allow a RIP or router-discovery 1013 * response to be heard. 1014 */ 1015 rtm_add(rtm,&info,MIN_WAITTIME); 1016 } 1017 free(buf); 1018 } 1019 1020 1021 /* Listen to announcements from the kernel 1022 */ 1023 void 1024 read_rt(void) 1025 { 1026 long cc; 1027 struct interface *ifp; 1028 naddr mask; 1029 union { 1030 struct { 1031 struct rt_msghdr rtm; 1032 struct sockaddr addrs[RTAX_MAX]; 1033 } r; 1034 struct if_msghdr ifm; 1035 } m; 1036 char str[100], *strp; 1037 struct rt_addrinfo info; 1038 1039 1040 for (;;) { 1041 cc = read(rt_sock, &m, sizeof(m)); 1042 if (cc <= 0) { 1043 if (cc < 0 && errno != EWOULDBLOCK) 1044 LOGERR("read(rt_sock)"); 1045 return; 1046 } 1047 1048 if (m.r.rtm.rtm_version != RTM_VERSION) { 1049 msglog("bogus routing message version %d", 1050 m.r.rtm.rtm_version); 1051 continue; 1052 } 1053 1054 /* Ignore our own results. 1055 */ 1056 if (m.r.rtm.rtm_type <= RTM_CHANGE 1057 && m.r.rtm.rtm_pid == mypid) { 1058 static int complained = 0; 1059 if (!complained) { 1060 msglog("receiving our own change messages"); 1061 complained = 1; 1062 } 1063 continue; 1064 } 1065 1066 if (m.r.rtm.rtm_type == RTM_IFINFO 1067 || m.r.rtm.rtm_type == RTM_NEWADDR 1068 || m.r.rtm.rtm_type == RTM_DELADDR) { 1069 ifp = ifwithindex(m.ifm.ifm_index); 1070 if (ifp == 0) 1071 trace_act("note %s with flags %#x" 1072 " for index #%d", 1073 rtm_type_name(m.r.rtm.rtm_type), 1074 m.ifm.ifm_flags, 1075 m.ifm.ifm_index); 1076 else 1077 trace_act("note %s with flags %#x for %s", 1078 rtm_type_name(m.r.rtm.rtm_type), 1079 m.ifm.ifm_flags, 1080 ifp->int_name); 1081 1082 /* After being informed of a change to an interface, 1083 * check them all now if the check would otherwise 1084 * be a long time from now, if the interface is 1085 * not known, or if the interface has been turned 1086 * off or on. 1087 */ 1088 if (ifinit_timer.tv_sec-now.tv_sec>=CHECK_BAD_INTERVAL 1089 || ifp == 0 1090 || ((ifp->int_if_flags ^ m.ifm.ifm_flags) 1091 & IFF_UP_RUNNING) != 0) 1092 ifinit_timer.tv_sec = now.tv_sec; 1093 continue; 1094 } 1095 1096 strcpy(str, rtm_type_name(m.r.rtm.rtm_type)); 1097 strp = &str[strlen(str)]; 1098 if (m.r.rtm.rtm_type <= RTM_CHANGE) 1099 strp += sprintf(strp," from pid %d",m.r.rtm.rtm_pid); 1100 1101 rt_xaddrs(&info, m.r.addrs, &m.r.addrs[RTAX_MAX], 1102 m.r.rtm.rtm_addrs); 1103 1104 if (INFO_DST(&info) == 0) { 1105 trace_act("ignore %s without dst", str); 1106 continue; 1107 } 1108 1109 if (INFO_DST(&info)->sa_family != AF_INET) { 1110 trace_act("ignore %s for AF %d", str, 1111 INFO_DST(&info)->sa_family); 1112 continue; 1113 } 1114 1115 mask = ((INFO_MASK(&info) != 0) 1116 ? ntohl(S_ADDR(INFO_MASK(&info))) 1117 : (m.r.rtm.rtm_flags & RTF_HOST) 1118 ? HOST_MASK 1119 : std_mask(S_ADDR(INFO_DST(&info)))); 1120 1121 strp += sprintf(strp, ": %s", 1122 addrname(S_ADDR(INFO_DST(&info)), mask, 0)); 1123 1124 if (IN_MULTICAST(ntohl(S_ADDR(INFO_DST(&info))))) { 1125 trace_act("ignore multicast %s", str); 1126 continue; 1127 } 1128 1129 if (INFO_GATE(&info) != 0 1130 && INFO_GATE(&info)->sa_family == AF_INET) 1131 strp += sprintf(strp, " --> %s", 1132 saddr_ntoa(INFO_GATE(&info))); 1133 1134 if (INFO_AUTHOR(&info) != 0) 1135 strp += sprintf(strp, " by authority of %s", 1136 saddr_ntoa(INFO_AUTHOR(&info))); 1137 1138 switch (m.r.rtm.rtm_type) { 1139 case RTM_ADD: 1140 case RTM_CHANGE: 1141 case RTM_REDIRECT: 1142 if (m.r.rtm.rtm_errno != 0) { 1143 trace_act("ignore %s with \"%s\" error", 1144 str, strerror(m.r.rtm.rtm_errno)); 1145 } else { 1146 trace_act("%s", str); 1147 rtm_add(&m.r.rtm,&info,0); 1148 } 1149 break; 1150 1151 case RTM_DELETE: 1152 if (m.r.rtm.rtm_errno != 0) { 1153 trace_act("ignore %s with \"%s\" error", 1154 str, strerror(m.r.rtm.rtm_errno)); 1155 } else { 1156 trace_act("%s", str); 1157 del_static(S_ADDR(INFO_DST(&info)), mask, 1); 1158 } 1159 break; 1160 1161 case RTM_LOSING: 1162 trace_act("%s", str); 1163 rtm_lose(&m.r.rtm,&info); 1164 break; 1165 1166 default: 1167 trace_act("ignore %s", str); 1168 break; 1169 } 1170 } 1171 } 1172 1173 1174 /* after aggregating, note routes that belong in the kernel 1175 */ 1176 static void 1177 kern_out(struct ag_info *ag) 1178 { 1179 struct khash *k; 1180 1181 1182 /* Do not install bad routes if they are not already present. 1183 * This includes routes that had RS_NET_SYN for interfaces that 1184 * recently died. 1185 */ 1186 if (ag->ag_metric == HOPCNT_INFINITY) { 1187 k = kern_find(htonl(ag->ag_dst_h), ag->ag_mask, 0); 1188 if (k == 0) 1189 return; 1190 } else { 1191 k = kern_add(htonl(ag->ag_dst_h), ag->ag_mask); 1192 } 1193 1194 if (k->k_state & KS_NEW) { 1195 /* will need to add new entry to the kernel table */ 1196 k->k_state = KS_ADD; 1197 if (ag->ag_state & AGS_GATEWAY) 1198 k->k_state |= KS_GATEWAY; 1199 k->k_gate = ag->ag_gate; 1200 k->k_metric = ag->ag_metric; 1201 return; 1202 } 1203 1204 if (k->k_state & KS_STATIC) 1205 return; 1206 1207 /* modify existing kernel entry if necessary */ 1208 if (k->k_gate != ag->ag_gate 1209 || k->k_metric != ag->ag_metric) { 1210 k->k_gate = ag->ag_gate; 1211 k->k_metric = ag->ag_metric; 1212 k->k_state |= KS_CHANGE; 1213 } 1214 1215 if (k->k_state & KS_DYNAMIC) { 1216 k->k_state &= ~KS_DYNAMIC; 1217 k->k_state |= (KS_ADD | KS_DEL_ADD); 1218 } 1219 1220 if ((k->k_state & KS_GATEWAY) 1221 && !(ag->ag_state & AGS_GATEWAY)) { 1222 k->k_state &= ~KS_GATEWAY; 1223 k->k_state |= (KS_ADD | KS_DEL_ADD); 1224 } else if (!(k->k_state & KS_GATEWAY) 1225 && (ag->ag_state & AGS_GATEWAY)) { 1226 k->k_state |= KS_GATEWAY; 1227 k->k_state |= (KS_ADD | KS_DEL_ADD); 1228 } 1229 1230 /* Deleting-and-adding is necessary to change aspects of a route. 1231 * Just delete instead of deleting and then adding a bad route. 1232 * Otherwise, we want to keep the route in the kernel. 1233 */ 1234 if (k->k_metric == HOPCNT_INFINITY 1235 && (k->k_state & KS_DEL_ADD)) 1236 k->k_state |= KS_DELETE; 1237 else 1238 k->k_state &= ~KS_DELETE; 1239 #undef RT 1240 } 1241 1242 1243 /* ARGSUSED */ 1244 static int 1245 walk_kern(struct radix_node *rn, 1246 struct walkarg *w) 1247 { 1248 #define RT ((struct rt_entry *)rn) 1249 char metric, pref; 1250 u_int ags = 0; 1251 1252 1253 /* Do not install synthetic routes */ 1254 if (RT->rt_state & RS_NET_SYN) 1255 return 0; 1256 1257 if (!(RT->rt_state & RS_IF)) { 1258 ags |= (AGS_GATEWAY | AGS_SUPPRESS | AGS_PROMOTE); 1259 1260 } else { 1261 /* Do not install routes for "external" remote interfaces. 1262 */ 1263 if (RT->rt_ifp != 0 && (RT->rt_ifp->int_state & IS_EXTERNAL)) 1264 return 0; 1265 1266 ags |= AGS_IF; 1267 1268 /* If it is not an interface, or an alias for an interface, 1269 * it must be a "gateway." 1270 * 1271 * If it is a "remote" interface, it is also a "gateway" to 1272 * the kernel if is not a alias. 1273 */ 1274 if (RT->rt_ifp == 0 1275 || (RT->rt_ifp->int_state & IS_REMOTE)) 1276 ags |= (AGS_GATEWAY | AGS_SUPPRESS | AGS_PROMOTE); 1277 } 1278 1279 if (RT->rt_state & RS_RDISC) 1280 ags |= AGS_CORS_GATE; 1281 1282 /* aggregate good routes without regard to their metric */ 1283 pref = 1; 1284 metric = RT->rt_metric; 1285 if (metric == HOPCNT_INFINITY) { 1286 /* if the route is dead, so try hard to aggregate. */ 1287 pref = HOPCNT_INFINITY; 1288 ags |= (AGS_FINE_GATE | AGS_SUPPRESS); 1289 } 1290 1291 ag_check(RT->rt_dst, RT->rt_mask, RT->rt_gate, 0, 1292 metric,pref, 0, 0, ags, kern_out); 1293 return 0; 1294 #undef RT 1295 } 1296 1297 1298 /* Update the kernel table to match the daemon table. 1299 */ 1300 static void 1301 fix_kern(void) 1302 { 1303 int i, flags; 1304 struct khash *k, **pk; 1305 1306 1307 need_kern = age_timer; 1308 1309 /* Walk daemon table, updating the copy of the kernel table. 1310 */ 1311 (void)rn_walktree(rhead, walk_kern, 0); 1312 ag_flush(0,0,kern_out); 1313 1314 for (i = 0; i < KHASH_SIZE; i++) { 1315 for (pk = &khash_bins[i]; (k = *pk) != 0; ) { 1316 /* Do not touch static routes */ 1317 if (k->k_state & KS_STATIC) { 1318 kern_check_static(k,0); 1319 pk = &k->k_next; 1320 continue; 1321 } 1322 1323 /* check hold on routes deleted by the operator */ 1324 if (k->k_keep > now.tv_sec) { 1325 LIM_SEC(need_kern, k->k_keep); 1326 k->k_state |= KS_DELETE; 1327 pk = &k->k_next; 1328 continue; 1329 } 1330 1331 if ((k->k_state & (KS_DELETE | KS_DYNAMIC)) 1332 == KS_DELETE) { 1333 if (!(k->k_state & KS_DELETED)) 1334 rtioctl(RTM_DELETE, 1335 k->k_dst, k->k_gate, k->k_mask, 1336 0, 0); 1337 *pk = k->k_next; 1338 free(k); 1339 continue; 1340 } 1341 1342 if (0 != (k->k_state&(KS_ADD|KS_CHANGE|KS_DEL_ADD))) { 1343 if (k->k_state & KS_DEL_ADD) { 1344 rtioctl(RTM_DELETE, 1345 k->k_dst,k->k_gate,k->k_mask, 1346 0, 0); 1347 k->k_state &= ~KS_DYNAMIC; 1348 } 1349 1350 flags = 0; 1351 if (0 != (k->k_state&(KS_GATEWAY|KS_DYNAMIC))) 1352 flags |= RTF_GATEWAY; 1353 1354 if (k->k_state & KS_ADD) { 1355 rtioctl(RTM_ADD, 1356 k->k_dst, k->k_gate, k->k_mask, 1357 k->k_metric, flags); 1358 } else if (k->k_state & KS_CHANGE) { 1359 rtioctl(RTM_CHANGE, 1360 k->k_dst,k->k_gate,k->k_mask, 1361 k->k_metric, flags); 1362 } 1363 k->k_state &= ~(KS_ADD|KS_CHANGE|KS_DEL_ADD); 1364 } 1365 1366 /* Mark this route to be deleted in the next cycle. 1367 * This deletes routes that disappear from the 1368 * daemon table, since the normal aging code 1369 * will clear the bit for routes that have not 1370 * disappeared from the daemon table. 1371 */ 1372 k->k_state |= KS_DELETE; 1373 pk = &k->k_next; 1374 } 1375 } 1376 } 1377 1378 1379 /* Delete a static route in the image of the kernel table. 1380 */ 1381 void 1382 del_static(naddr dst, 1383 naddr mask, 1384 int gone) 1385 { 1386 struct khash *k; 1387 struct rt_entry *rt; 1388 1389 /* Just mark it in the table to be deleted next time the kernel 1390 * table is updated. 1391 * If it has already been deleted, mark it as such, and set its 1392 * keep-timer so that it will not be deleted again for a while. 1393 * This lets the operator delete a route added by the daemon 1394 * and add a replacement. 1395 */ 1396 k = kern_find(dst, mask, 0); 1397 if (k != 0) { 1398 k->k_state &= ~(KS_STATIC | KS_DYNAMIC); 1399 k->k_state |= KS_DELETE; 1400 if (gone) { 1401 k->k_state |= KS_DELETED; 1402 k->k_keep = now.tv_sec + K_KEEP_LIM; 1403 } 1404 } 1405 1406 rt = rtget(dst, mask); 1407 if (rt != 0 && (rt->rt_state & RS_STATIC)) 1408 rtbad(rt); 1409 } 1410 1411 1412 /* Delete all routes generated from ICMP Redirects that use a given gateway, 1413 * as well as old redirected routes. 1414 */ 1415 void 1416 del_redirects(naddr bad_gate, 1417 time_t old) 1418 { 1419 int i; 1420 struct khash *k; 1421 1422 1423 for (i = 0; i < KHASH_SIZE; i++) { 1424 for (k = khash_bins[i]; k != 0; k = k->k_next) { 1425 if (!(k->k_state & KS_DYNAMIC) 1426 || (k->k_state & KS_STATIC)) 1427 continue; 1428 1429 if (k->k_gate != bad_gate 1430 && k->k_redirect_time > old 1431 && !supplier) 1432 continue; 1433 1434 k->k_state |= KS_DELETE; 1435 k->k_state &= ~KS_DYNAMIC; 1436 need_kern.tv_sec = now.tv_sec; 1437 trace_act("mark redirected %s --> %s for deletion", 1438 addrname(k->k_dst, k->k_mask, 0), 1439 naddr_ntoa(k->k_gate)); 1440 } 1441 } 1442 } 1443 1444 1445 /* Start the daemon tables. 1446 */ 1447 void 1448 rtinit(void) 1449 { 1450 extern int max_keylen; 1451 int i; 1452 struct ag_info *ag; 1453 1454 /* Initialize the radix trees */ 1455 max_keylen = sizeof(struct sockaddr_in); 1456 rn_init(); 1457 rn_inithead((void**)&rhead, 32); 1458 1459 /* mark all of the slots in the table free */ 1460 ag_avail = ag_slots; 1461 for (ag = ag_slots, i = 1; i < NUM_AG_SLOTS; i++) { 1462 ag->ag_fine = ag+1; 1463 ag++; 1464 } 1465 } 1466 1467 1468 #ifdef _HAVE_SIN_LEN 1469 static struct sockaddr_in dst_sock = {sizeof(dst_sock), AF_INET}; 1470 static struct sockaddr_in mask_sock = {sizeof(mask_sock), AF_INET}; 1471 #else 1472 static struct sockaddr_in_new dst_sock = {_SIN_ADDR_SIZE, AF_INET}; 1473 static struct sockaddr_in_new mask_sock = {_SIN_ADDR_SIZE, AF_INET}; 1474 #endif 1475 1476 1477 void 1478 set_need_flash(void) 1479 { 1480 if (!need_flash) { 1481 need_flash = 1; 1482 /* Do not send the flash update immediately. Wait a little 1483 * while to hear from other routers. 1484 */ 1485 no_flash.tv_sec = now.tv_sec + MIN_WAITTIME; 1486 } 1487 } 1488 1489 1490 /* Get a particular routing table entry 1491 */ 1492 struct rt_entry * 1493 rtget(naddr dst, naddr mask) 1494 { 1495 struct rt_entry *rt; 1496 1497 dst_sock.sin_addr.s_addr = dst; 1498 mask_sock.sin_addr.s_addr = mask; 1499 masktrim(&mask_sock); 1500 rt = (struct rt_entry *)rhead->rnh_lookup(&dst_sock,&mask_sock,rhead); 1501 if (!rt 1502 || rt->rt_dst != dst 1503 || rt->rt_mask != mask) 1504 return 0; 1505 1506 return rt; 1507 } 1508 1509 1510 /* Find a route to dst as the kernel would. 1511 */ 1512 struct rt_entry * 1513 rtfind(naddr dst) 1514 { 1515 dst_sock.sin_addr.s_addr = dst; 1516 return (struct rt_entry *)rhead->rnh_matchaddr(&dst_sock, rhead); 1517 } 1518 1519 1520 /* add a route to the table 1521 */ 1522 void 1523 rtadd(naddr dst, 1524 naddr mask, 1525 naddr gate, /* forward packets here */ 1526 naddr router, /* on the authority of this router */ 1527 int metric, 1528 u_short tag, 1529 u_int state, /* rs_state for the entry */ 1530 struct interface *ifp) 1531 { 1532 struct rt_entry *rt; 1533 naddr smask; 1534 int i; 1535 struct rt_spare *rts; 1536 1537 rt = (struct rt_entry *)rtmalloc(sizeof (*rt), "rtadd"); 1538 bzero(rt, sizeof(*rt)); 1539 for (rts = rt->rt_spares, i = NUM_SPARES; i != 0; i--, rts++) 1540 rts->rts_metric = HOPCNT_INFINITY; 1541 1542 rt->rt_nodes->rn_key = (caddr_t)&rt->rt_dst_sock; 1543 rt->rt_dst = dst; 1544 rt->rt_dst_sock.sin_family = AF_INET; 1545 #ifdef _HAVE_SIN_LEN 1546 rt->rt_dst_sock.sin_len = dst_sock.sin_len; 1547 #endif 1548 if (mask != HOST_MASK) { 1549 smask = std_mask(dst); 1550 if ((smask & ~mask) == 0 && mask > smask) 1551 state |= RS_SUBNET; 1552 } 1553 mask_sock.sin_addr.s_addr = mask; 1554 masktrim(&mask_sock); 1555 rt->rt_mask = mask; 1556 rt->rt_state = state; 1557 rt->rt_gate = gate; 1558 rt->rt_router = router; 1559 rt->rt_time = now.tv_sec; 1560 rt->rt_metric = metric; 1561 rt->rt_poison_metric = HOPCNT_INFINITY; 1562 rt->rt_tag = tag; 1563 rt->rt_ifp = ifp; 1564 rt->rt_seqno = update_seqno; 1565 1566 if (++total_routes == MAX_ROUTES) 1567 msglog("have maximum (%d) routes", total_routes); 1568 if (TRACEACTIONS) 1569 trace_add_del("Add", rt); 1570 1571 need_kern.tv_sec = now.tv_sec; 1572 set_need_flash(); 1573 1574 if (0 == rhead->rnh_addaddr(&rt->rt_dst_sock, &mask_sock, 1575 rhead, rt->rt_nodes)) { 1576 /* 1577 * This will happen if RIP1 and RIP2 routeds talk to one another and 1578 * there are variable subnets. This is only good for filling up your 1579 * syslog. -jkh 1580 */ 1581 #if 0 1582 msglog("rnh_addaddr() failed for %s mask=%#x", 1583 naddr_ntoa(dst), mask); 1584 #endif 1585 } 1586 } 1587 1588 1589 /* notice a changed route 1590 */ 1591 void 1592 rtchange(struct rt_entry *rt, 1593 u_int state, /* new state bits */ 1594 naddr gate, /* now forward packets here */ 1595 naddr router, /* on the authority of this router */ 1596 int metric, /* new metric */ 1597 u_short tag, 1598 struct interface *ifp, 1599 time_t new_time, 1600 char *label) 1601 { 1602 if (rt->rt_metric != metric) { 1603 /* Fix the kernel immediately if it seems the route 1604 * has gone bad, since there may be a working route that 1605 * aggregates this route. 1606 */ 1607 if (metric == HOPCNT_INFINITY) { 1608 need_kern.tv_sec = now.tv_sec; 1609 if (new_time >= now.tv_sec - EXPIRE_TIME) 1610 new_time = now.tv_sec - EXPIRE_TIME; 1611 } 1612 rt->rt_seqno = update_seqno; 1613 set_need_flash(); 1614 } 1615 1616 if (rt->rt_gate != gate) { 1617 need_kern.tv_sec = now.tv_sec; 1618 rt->rt_seqno = update_seqno; 1619 set_need_flash(); 1620 } 1621 1622 state |= (rt->rt_state & RS_SUBNET); 1623 1624 /* Keep various things from deciding ageless routes are stale. 1625 */ 1626 if (!AGE_RT(state, ifp)) 1627 new_time = now.tv_sec; 1628 1629 if (TRACEACTIONS) 1630 trace_change(rt, state, gate, router, metric, tag, ifp, 1631 new_time, 1632 label ? label : "Chg "); 1633 1634 rt->rt_state = state; 1635 rt->rt_gate = gate; 1636 rt->rt_router = router; 1637 rt->rt_metric = metric; 1638 rt->rt_tag = tag; 1639 rt->rt_ifp = ifp; 1640 rt->rt_time = new_time; 1641 } 1642 1643 1644 /* check for a better route among the spares 1645 */ 1646 static struct rt_spare * 1647 rts_better(struct rt_entry *rt) 1648 { 1649 struct rt_spare *rts, *rts1; 1650 int i; 1651 1652 /* find the best alternative among the spares */ 1653 rts = rt->rt_spares+1; 1654 for (i = NUM_SPARES, rts1 = rts+1; i > 2; i--, rts1++) { 1655 if (BETTER_LINK(rt,rts1,rts)) 1656 rts = rts1; 1657 } 1658 1659 return rts; 1660 } 1661 1662 1663 /* switch to a backup route 1664 */ 1665 void 1666 rtswitch(struct rt_entry *rt, 1667 struct rt_spare *rts) 1668 { 1669 struct rt_spare swap; 1670 char label[10]; 1671 1672 1673 /* Do not change permanent routes */ 1674 if (0 != (rt->rt_state & (RS_MHOME | RS_STATIC | RS_RDISC 1675 | RS_NET_SYN | RS_IF))) 1676 return; 1677 1678 /* find the best alternative among the spares */ 1679 if (rts == 0) 1680 rts = rts_better(rt); 1681 1682 /* Do not bother if it is not worthwhile. 1683 */ 1684 if (!BETTER_LINK(rt, rts, rt->rt_spares)) 1685 return; 1686 1687 swap = rt->rt_spares[0]; 1688 (void)sprintf(label, "Use #%d", rts - rt->rt_spares); 1689 rtchange(rt, rt->rt_state & ~(RS_NET_SYN | RS_RDISC), 1690 rts->rts_gate, rts->rts_router, rts->rts_metric, 1691 rts->rts_tag, rts->rts_ifp, rts->rts_time, label); 1692 *rts = swap; 1693 } 1694 1695 1696 void 1697 rtdelete(struct rt_entry *rt) 1698 { 1699 struct khash *k; 1700 1701 1702 if (TRACEACTIONS) 1703 trace_add_del("Del", rt); 1704 1705 k = kern_find(rt->rt_dst, rt->rt_mask, 0); 1706 if (k != 0) { 1707 k->k_state |= KS_DELETE; 1708 need_kern.tv_sec = now.tv_sec; 1709 } 1710 1711 dst_sock.sin_addr.s_addr = rt->rt_dst; 1712 mask_sock.sin_addr.s_addr = rt->rt_mask; 1713 masktrim(&mask_sock); 1714 if (rt != (struct rt_entry *)rhead->rnh_deladdr(&dst_sock, &mask_sock, 1715 rhead)) { 1716 msglog("rnh_deladdr() failed"); 1717 } else { 1718 free(rt); 1719 total_routes--; 1720 } 1721 } 1722 1723 1724 /* Get rid of a bad route, and try to switch to a replacement. 1725 */ 1726 void 1727 rtbad(struct rt_entry *rt) 1728 { 1729 /* Poison the route */ 1730 rtchange(rt, rt->rt_state & ~(RS_IF | RS_LOCAL | RS_STATIC), 1731 rt->rt_gate, rt->rt_router, HOPCNT_INFINITY, rt->rt_tag, 1732 0, rt->rt_time, 0); 1733 1734 rtswitch(rt, 0); 1735 } 1736 1737 1738 /* Junk a RS_NET_SYN or RS_LOCAL route, 1739 * unless it is needed by another interface. 1740 */ 1741 void 1742 rtbad_sub(struct rt_entry *rt) 1743 { 1744 struct interface *ifp, *ifp1; 1745 struct intnet *intnetp; 1746 u_int state; 1747 1748 1749 ifp1 = 0; 1750 state = 0; 1751 1752 if (rt->rt_state & RS_LOCAL) { 1753 /* Is this the route through loopback for the interface? 1754 * If so, see if it is used by any other interfaces, such 1755 * as a point-to-point interface with the same local address. 1756 */ 1757 for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) { 1758 /* Retain it if another interface needs it. 1759 */ 1760 if (ifp->int_addr == rt->rt_ifp->int_addr) { 1761 state |= RS_LOCAL; 1762 ifp1 = ifp; 1763 break; 1764 } 1765 } 1766 1767 } 1768 1769 if (!(state & RS_LOCAL)) { 1770 /* Retain RIPv1 logical network route if there is another 1771 * interface that justifies it. 1772 */ 1773 if (rt->rt_state & RS_NET_SYN) { 1774 for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) { 1775 if ((ifp->int_state & IS_NEED_NET_SYN) 1776 && rt->rt_mask == ifp->int_std_mask 1777 && rt->rt_dst == ifp->int_std_addr) { 1778 state |= RS_NET_SYN; 1779 ifp1 = ifp; 1780 break; 1781 } 1782 } 1783 } 1784 1785 /* or if there is an authority route that needs it. */ 1786 for (intnetp = intnets; 1787 intnetp != 0; 1788 intnetp = intnetp->intnet_next) { 1789 if (intnetp->intnet_addr == rt->rt_dst 1790 && intnetp->intnet_mask == rt->rt_mask) { 1791 state |= (RS_NET_SYN | RS_NET_INT); 1792 break; 1793 } 1794 } 1795 } 1796 1797 if (ifp1 != 0 || (state & RS_NET_SYN)) { 1798 rtchange(rt, ((rt->rt_state & ~(RS_NET_SYN | RS_LOCAL)) 1799 | state), 1800 rt->rt_gate, rt->rt_router, rt->rt_metric, 1801 rt->rt_tag, ifp1, rt->rt_time, 0); 1802 } else { 1803 rtbad(rt); 1804 } 1805 } 1806 1807 1808 /* Called while walking the table looking for sick interfaces 1809 * or after a time change. 1810 */ 1811 /* ARGSUSED */ 1812 int 1813 walk_bad(struct radix_node *rn, 1814 struct walkarg *w) 1815 { 1816 #define RT ((struct rt_entry *)rn) 1817 struct rt_spare *rts; 1818 int i; 1819 time_t new_time; 1820 1821 1822 /* fix any spare routes through the interface 1823 */ 1824 rts = RT->rt_spares; 1825 for (i = NUM_SPARES; i != 1; i--) { 1826 rts++; 1827 1828 if (rts->rts_ifp != 0 1829 && (rts->rts_ifp->int_state & IS_BROKE)) { 1830 /* mark the spare route to be deleted immediately */ 1831 new_time = rts->rts_time; 1832 if (new_time >= now_garbage) 1833 new_time = now_garbage-1; 1834 trace_upslot(RT, rts, rts->rts_gate, 1835 rts->rts_router, 0, 1836 HOPCNT_INFINITY, rts->rts_tag, 1837 new_time); 1838 rts->rts_ifp = 0; 1839 rts->rts_metric = HOPCNT_INFINITY; 1840 rts->rts_time = new_time; 1841 } 1842 } 1843 1844 /* Deal with the main route 1845 */ 1846 /* finished if it has been handled before or if its interface is ok 1847 */ 1848 if (RT->rt_ifp == 0 || !(RT->rt_ifp->int_state & IS_BROKE)) 1849 return 0; 1850 1851 /* Bad routes for other than interfaces are easy. 1852 */ 1853 if (0 == (RT->rt_state & (RS_IF | RS_NET_SYN | RS_LOCAL))) { 1854 rtbad(RT); 1855 return 0; 1856 } 1857 1858 rtbad_sub(RT); 1859 return 0; 1860 #undef RT 1861 } 1862 1863 1864 /* Check the age of an individual route. 1865 */ 1866 /* ARGSUSED */ 1867 static int 1868 walk_age(struct radix_node *rn, 1869 struct walkarg *w) 1870 { 1871 #define RT ((struct rt_entry *)rn) 1872 struct interface *ifp; 1873 struct rt_spare *rts; 1874 int i; 1875 1876 1877 /* age all of the spare routes, including the primary route 1878 * currently in use 1879 */ 1880 rts = RT->rt_spares; 1881 for (i = NUM_SPARES; i != 0; i--, rts++) { 1882 1883 ifp = rts->rts_ifp; 1884 if (i == NUM_SPARES) { 1885 if (!AGE_RT(RT->rt_state, ifp)) { 1886 /* Keep various things from deciding ageless 1887 * routes are stale 1888 */ 1889 rts->rts_time = now.tv_sec; 1890 continue; 1891 } 1892 1893 /* forget RIP routes after RIP has been turned off. 1894 */ 1895 if (rip_sock < 0) { 1896 rtdelete(RT); 1897 return 0; 1898 } 1899 } 1900 1901 /* age failing routes 1902 */ 1903 if (age_bad_gate == rts->rts_gate 1904 && rts->rts_time >= now_stale) { 1905 rts->rts_time -= SUPPLY_INTERVAL; 1906 } 1907 1908 /* trash the spare routes when they go bad */ 1909 if (rts->rts_metric < HOPCNT_INFINITY 1910 && now_garbage > rts->rts_time) { 1911 trace_upslot(RT, rts, rts->rts_gate, 1912 rts->rts_router, rts->rts_ifp, 1913 HOPCNT_INFINITY, rts->rts_tag, 1914 rts->rts_time); 1915 rts->rts_metric = HOPCNT_INFINITY; 1916 } 1917 } 1918 1919 1920 /* finished if the active route is still fresh */ 1921 if (now_stale <= RT->rt_time) 1922 return 0; 1923 1924 /* try to switch to an alternative */ 1925 rtswitch(RT, 0); 1926 1927 /* Delete a dead route after it has been publically mourned. */ 1928 if (now_garbage > RT->rt_time) { 1929 rtdelete(RT); 1930 return 0; 1931 } 1932 1933 /* Start poisoning a bad route before deleting it. */ 1934 if (now.tv_sec - RT->rt_time > EXPIRE_TIME) 1935 rtchange(RT, RT->rt_state, RT->rt_gate, RT->rt_router, 1936 HOPCNT_INFINITY, RT->rt_tag, RT->rt_ifp, 1937 RT->rt_time, 0); 1938 return 0; 1939 } 1940 1941 1942 /* Watch for dead routes and interfaces. 1943 */ 1944 void 1945 age(naddr bad_gate) 1946 { 1947 struct interface *ifp; 1948 int need_query = 0; 1949 1950 /* If not listening to RIP, there is no need to age the routes in 1951 * the table. 1952 */ 1953 age_timer.tv_sec = (now.tv_sec 1954 + ((rip_sock < 0) ? NEVER : SUPPLY_INTERVAL)); 1955 1956 /* Check for dead IS_REMOTE interfaces by timing their 1957 * transmissions. 1958 */ 1959 for (ifp = ifnet; ifp; ifp = ifp->int_next) { 1960 if (!(ifp->int_state & IS_REMOTE)) 1961 continue; 1962 1963 /* ignore unreachable remote interfaces */ 1964 if (!check_remote(ifp)) 1965 continue; 1966 /* Restore remote interface that has become reachable 1967 */ 1968 if (ifp->int_state & IS_BROKE) 1969 if_ok(ifp, "remote "); 1970 1971 if (ifp->int_act_time != NEVER 1972 && now.tv_sec - ifp->int_act_time > EXPIRE_TIME) { 1973 msglog("remote interface %s to %s timed out after" 1974 " %d:%d", 1975 ifp->int_name, 1976 naddr_ntoa(ifp->int_dstaddr), 1977 (now.tv_sec - ifp->int_act_time)/60, 1978 (now.tv_sec - ifp->int_act_time)%60); 1979 if_sick(ifp); 1980 } 1981 1982 /* If we have not heard from the other router 1983 * recently, ask it. 1984 */ 1985 if (now.tv_sec >= ifp->int_query_time) { 1986 ifp->int_query_time = NEVER; 1987 need_query = 1; 1988 } 1989 } 1990 1991 /* Age routes. */ 1992 age_bad_gate = bad_gate; 1993 (void)rn_walktree(rhead, walk_age, 0); 1994 1995 /* Update the kernel routing table. */ 1996 fix_kern(); 1997 1998 /* poke reticent remote gateways */ 1999 if (need_query) 2000 rip_query(); 2001 } 2002