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 #ident "$Revision: 1.1.1.1 $" 40 41 #include "defs.h" 42 43 static struct rt_spare *rts_better(struct rt_entry *); 44 45 struct radix_node_head *rhead; /* root of the radix tree */ 46 47 int need_flash = 1; /* flash update needed 48 * start =1 to suppress the 1st 49 */ 50 51 struct timeval age_timer; /* next check of old routes */ 52 struct timeval need_kern = { /* need to update kernel table */ 53 EPOCH+MIN_WAITTIME-1 54 }; 55 56 int stopint; 57 58 int total_routes; 59 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\n", 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; 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("punt %s without mask", 835 rtm_type_name(rtm->rtm_type)); 836 return; 837 } 838 839 if (INFO_GATE(info) == 0 840 || INFO_GATE(info)->sa_family != AF_INET) { 841 msglog("punt %s without gateway", 842 rtm_type_name(rtm->rtm_type)); 843 return; 844 } 845 846 k = kern_add(S_ADDR(INFO_DST(info)), mask); 847 if (k->k_state & KS_NEW) 848 k->k_keep = now.tv_sec+keep; 849 k->k_gate = S_ADDR(INFO_GATE(info)); 850 k->k_metric = rtm->rtm_rmx.rmx_hopcount; 851 if (k->k_metric < 0) 852 k->k_metric = 0; 853 else if (k->k_metric > HOPCNT_INFINITY) 854 k->k_metric = HOPCNT_INFINITY; 855 k->k_state &= ~(KS_DELETED | KS_GATEWAY | KS_STATIC | KS_NEW); 856 if (rtm->rtm_flags & RTF_GATEWAY) 857 k->k_state |= KS_GATEWAY; 858 if (rtm->rtm_flags & RTF_STATIC) 859 k->k_state |= KS_STATIC; 860 861 if (0 != (rtm->rtm_flags & (RTF_DYNAMIC | RTF_MODIFIED))) { 862 if (supplier) { 863 /* Routers are not supposed to listen to redirects, 864 * so delete it. 865 */ 866 k->k_state &= ~KS_DYNAMIC; 867 k->k_state |= KS_DELETE; 868 LIM_SEC(need_kern, 0); 869 trace_act("mark redirected %s --> %s for deletion" 870 " since this is a router\n", 871 addrname(k->k_dst, k->k_mask, 0), 872 naddr_ntoa(k->k_gate)); 873 } else { 874 k->k_state |= KS_DYNAMIC; 875 k->k_redirect_time = now.tv_sec; 876 } 877 return; 878 } 879 880 /* If it is not a static route, quit until the next comparison 881 * between the kernel and daemon tables, when it will be deleted. 882 */ 883 if (!(k->k_state & KS_STATIC)) { 884 k->k_state |= KS_DELETE; 885 LIM_SEC(need_kern, k->k_keep); 886 return; 887 } 888 889 /* Put static routes with real metrics into the daemon table so 890 * they can be advertised. 891 * 892 * Find the interface concerned 893 */ 894 ifp = iflookup(k->k_gate); 895 if (ifp == 0) { 896 /* if there is no known interface, 897 * maybe there is a new interface 898 */ 899 ifinit(); 900 ifp = iflookup(k->k_gate); 901 if (ifp == 0) 902 msglog("static route %s --> %s impossibly lacks ifp", 903 addrname(S_ADDR(INFO_DST(info)), mask, 0), 904 naddr_ntoa(k->k_gate)); 905 } 906 907 kern_check_static(k, ifp); 908 } 909 910 911 /* deal with packet loss 912 */ 913 static void 914 rtm_lose(struct rt_msghdr *rtm, 915 struct rt_addrinfo *info) 916 { 917 if (INFO_GATE(info) == 0 918 || INFO_GATE(info)->sa_family != AF_INET) { 919 msglog("punt %s without gateway", 920 rtm_type_name(rtm->rtm_type)); 921 return; 922 } 923 924 if (!supplier) 925 rdisc_age(S_ADDR(INFO_GATE(info))); 926 927 age(S_ADDR(INFO_GATE(info))); 928 } 929 930 931 /* Clean the kernel table by copying it to the daemon image. 932 * Eventually the daemon will delete any extra routes. 933 */ 934 void 935 flush_kern(void) 936 { 937 size_t needed; 938 int mib[6]; 939 char *buf, *next, *lim; 940 struct rt_msghdr *rtm; 941 struct interface *ifp; 942 static struct sockaddr_in gate_sa; 943 struct rt_addrinfo info; 944 945 946 mib[0] = CTL_NET; 947 mib[1] = PF_ROUTE; 948 mib[2] = 0; /* protocol */ 949 mib[3] = 0; /* wildcard address family */ 950 mib[4] = NET_RT_DUMP; 951 mib[5] = 0; /* no flags */ 952 if (sysctl(mib, 6, 0, &needed, 0, 0) < 0) { 953 DBGERR(1,"RT_DUMP-sysctl-estimate"); 954 return; 955 } 956 buf = malloc(needed); 957 if (sysctl(mib, 6, buf, &needed, 0, 0) < 0) 958 BADERR(1,"RT_DUMP"); 959 lim = buf + needed; 960 for (next = buf; next < lim; next += rtm->rtm_msglen) { 961 rtm = (struct rt_msghdr *)next; 962 963 rt_xaddrs(&info, 964 (struct sockaddr *)(rtm+1), 965 (struct sockaddr *)(next + rtm->rtm_msglen), 966 rtm->rtm_addrs); 967 968 if (INFO_DST(&info) == 0 969 || INFO_DST(&info)->sa_family != AF_INET) 970 continue; 971 972 /* ignore ARP table entries on systems with a merged route 973 * and ARP table. 974 */ 975 if (rtm->rtm_flags & RTF_LLINFO) 976 continue; 977 978 if (INFO_GATE(&info) == 0) 979 continue; 980 if (INFO_GATE(&info)->sa_family != AF_INET) { 981 if (INFO_GATE(&info)->sa_family != AF_LINK) 982 continue; 983 ifp = ifwithindex(((struct sockaddr_dl *) 984 INFO_GATE(&info))->sdl_index); 985 if (ifp == 0) 986 continue; 987 if ((ifp->int_if_flags & IFF_POINTOPOINT) 988 || S_ADDR(INFO_DST(&info)) == ifp->int_addr) 989 gate_sa.sin_addr.s_addr = ifp->int_addr; 990 else 991 gate_sa.sin_addr.s_addr = htonl(ifp->int_net); 992 #ifdef _HAVE_SA_LEN 993 gate_sa.sin_len = sizeof(gate_sa); 994 #endif 995 gate_sa.sin_family = AF_INET; 996 INFO_GATE(&info) = (struct sockaddr *)&gate_sa; 997 } 998 999 /* ignore multicast addresses 1000 */ 1001 if (IN_MULTICAST(ntohl(S_ADDR(INFO_DST(&info))))) 1002 continue; 1003 1004 /* Note static routes and interface routes, and also 1005 * preload the image of the kernel table so that 1006 * we can later clean it, as well as avoid making 1007 * unneeded changes. Keep the old kernel routes for a 1008 * few seconds to allow a RIP or router-discovery 1009 * response to be heard. 1010 */ 1011 rtm_add(rtm,&info,MIN_WAITTIME); 1012 } 1013 free(buf); 1014 } 1015 1016 1017 /* Listen to announcements from the kernel 1018 */ 1019 void 1020 read_rt(void) 1021 { 1022 long cc; 1023 struct interface *ifp; 1024 naddr mask; 1025 union { 1026 struct { 1027 struct rt_msghdr rtm; 1028 struct sockaddr addrs[RTAX_MAX]; 1029 } r; 1030 struct if_msghdr ifm; 1031 } m; 1032 char str[100], *strp; 1033 struct rt_addrinfo info; 1034 1035 1036 for (;;) { 1037 cc = read(rt_sock, &m, sizeof(m)); 1038 if (cc <= 0) { 1039 if (cc < 0 && errno != EWOULDBLOCK) 1040 LOGERR("read(rt_sock)"); 1041 return; 1042 } 1043 1044 if (m.r.rtm.rtm_version != RTM_VERSION) { 1045 msglog("bogus routing message version %d", 1046 m.r.rtm.rtm_version); 1047 continue; 1048 } 1049 1050 /* Ignore our own results. 1051 */ 1052 if (m.r.rtm.rtm_type <= RTM_CHANGE 1053 && m.r.rtm.rtm_pid == mypid) { 1054 static int complained = 0; 1055 if (!complained) { 1056 msglog("receiving our own change messages"); 1057 complained = 1; 1058 } 1059 continue; 1060 } 1061 1062 if (m.r.rtm.rtm_type == RTM_IFINFO 1063 || m.r.rtm.rtm_type == RTM_NEWADDR 1064 || m.r.rtm.rtm_type == RTM_DELADDR) { 1065 ifp = ifwithindex(m.ifm.ifm_index); 1066 if (ifp == 0) 1067 trace_act("note %s with flags %#x" 1068 " for index #%d\n", 1069 rtm_type_name(m.r.rtm.rtm_type), 1070 m.ifm.ifm_flags, 1071 m.ifm.ifm_index); 1072 else 1073 trace_act("note %s with flags %#x for %s\n", 1074 rtm_type_name(m.r.rtm.rtm_type), 1075 m.ifm.ifm_flags, 1076 ifp->int_name); 1077 1078 /* After being informed of a change to an interface, 1079 * check them all now if the check would otherwise 1080 * be a long time from now, if the interface is 1081 * not known, or if the interface has been turned 1082 * off or on. 1083 */ 1084 if (ifinit_timer.tv_sec-now.tv_sec>=CHECK_BAD_INTERVAL 1085 || ifp == 0 1086 || ((ifp->int_if_flags ^ m.ifm.ifm_flags) 1087 & IFF_UP_RUNNING) != 0) 1088 ifinit_timer.tv_sec = now.tv_sec; 1089 continue; 1090 } 1091 1092 strcpy(str, rtm_type_name(m.r.rtm.rtm_type)); 1093 strp = &str[strlen(str)]; 1094 if (m.r.rtm.rtm_type <= RTM_CHANGE) 1095 strp += sprintf(strp," from pid %d",m.r.rtm.rtm_pid); 1096 1097 rt_xaddrs(&info, m.r.addrs, &m.r.addrs[RTAX_MAX], 1098 m.r.rtm.rtm_addrs); 1099 1100 if (INFO_DST(&info) == 0) { 1101 trace_act("ignore %s without dst\n", str); 1102 continue; 1103 } 1104 1105 if (INFO_DST(&info)->sa_family != AF_INET) { 1106 trace_act("ignore %s for AF %d\n", str, 1107 INFO_DST(&info)->sa_family); 1108 continue; 1109 } 1110 1111 mask = ((INFO_MASK(&info) != 0) 1112 ? ntohl(S_ADDR(INFO_MASK(&info))) 1113 : (m.r.rtm.rtm_flags & RTF_HOST) 1114 ? HOST_MASK 1115 : std_mask(S_ADDR(INFO_DST(&info)))); 1116 1117 strp += sprintf(strp, ": %s", 1118 addrname(S_ADDR(INFO_DST(&info)), mask, 0)); 1119 1120 if (IN_MULTICAST(ntohl(S_ADDR(INFO_DST(&info))))) { 1121 trace_act("ignore multicast %s\n", str); 1122 continue; 1123 } 1124 1125 if (INFO_GATE(&info) != 0 1126 && INFO_GATE(&info)->sa_family == AF_INET) 1127 strp += sprintf(strp, " --> %s", 1128 saddr_ntoa(INFO_GATE(&info))); 1129 1130 if (INFO_AUTHOR(&info) != 0) 1131 strp += sprintf(strp, " by authority of %s", 1132 saddr_ntoa(INFO_AUTHOR(&info))); 1133 1134 switch (m.r.rtm.rtm_type) { 1135 case RTM_ADD: 1136 case RTM_CHANGE: 1137 case RTM_REDIRECT: 1138 if (m.r.rtm.rtm_errno != 0) { 1139 trace_act("ignore %s with \"%s\" error\n", 1140 str, strerror(m.r.rtm.rtm_errno)); 1141 } else { 1142 trace_act("%s\n", str); 1143 rtm_add(&m.r.rtm,&info,0); 1144 } 1145 break; 1146 1147 case RTM_DELETE: 1148 if (m.r.rtm.rtm_errno != 0) { 1149 trace_act("ignore %s with \"%s\" error\n", 1150 str, strerror(m.r.rtm.rtm_errno)); 1151 } else { 1152 trace_act("%s\n", str); 1153 del_static(S_ADDR(INFO_DST(&info)), mask, 1); 1154 } 1155 break; 1156 1157 case RTM_LOSING: 1158 trace_act("%s\n", str); 1159 rtm_lose(&m.r.rtm,&info); 1160 break; 1161 1162 default: 1163 trace_act("ignore %s\n", str); 1164 break; 1165 } 1166 } 1167 } 1168 1169 1170 /* after aggregating, note routes that belong in the kernel 1171 */ 1172 static void 1173 kern_out(struct ag_info *ag) 1174 { 1175 struct khash *k; 1176 1177 1178 /* Do not install bad routes if they are not already present. 1179 * This includes routes that had RS_NET_SYN for interfaces that 1180 * recently died. 1181 */ 1182 if (ag->ag_metric == HOPCNT_INFINITY) { 1183 k = kern_find(htonl(ag->ag_dst_h), ag->ag_mask, 0); 1184 if (k == 0) 1185 return; 1186 } else { 1187 k = kern_add(htonl(ag->ag_dst_h), ag->ag_mask); 1188 } 1189 1190 if (k->k_state & KS_NEW) { 1191 /* will need to add new entry to the kernel table */ 1192 k->k_state = KS_ADD; 1193 if (ag->ag_state & AGS_GATEWAY) 1194 k->k_state |= KS_GATEWAY; 1195 k->k_gate = ag->ag_gate; 1196 k->k_metric = ag->ag_metric; 1197 return; 1198 } 1199 1200 if (k->k_state & KS_STATIC) 1201 return; 1202 1203 /* modify existing kernel entry if necessary */ 1204 if (k->k_gate != ag->ag_gate 1205 || k->k_metric != ag->ag_metric) { 1206 k->k_gate = ag->ag_gate; 1207 k->k_metric = ag->ag_metric; 1208 k->k_state |= KS_CHANGE; 1209 } 1210 1211 if (k->k_state & KS_DYNAMIC) { 1212 k->k_state &= ~KS_DYNAMIC; 1213 k->k_state |= (KS_ADD | KS_DEL_ADD); 1214 } 1215 1216 if ((k->k_state & KS_GATEWAY) 1217 && !(ag->ag_state & AGS_GATEWAY)) { 1218 k->k_state &= ~KS_GATEWAY; 1219 k->k_state |= (KS_ADD | KS_DEL_ADD); 1220 } else 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 } 1225 1226 /* Deleting-and-adding is necessary to change aspects of a route. 1227 * Just delete instead of deleting and then adding a bad route. 1228 * Otherwise, we want to keep the route in the kernel. 1229 */ 1230 if (k->k_metric == HOPCNT_INFINITY 1231 && (k->k_state & KS_DEL_ADD)) 1232 k->k_state |= KS_DELETE; 1233 else 1234 k->k_state &= ~KS_DELETE; 1235 #undef RT 1236 } 1237 1238 1239 /* ARGSUSED */ 1240 static int 1241 walk_kern(struct radix_node *rn, 1242 struct walkarg *w) 1243 { 1244 #define RT ((struct rt_entry *)rn) 1245 char metric, pref; 1246 u_int ags = 0; 1247 1248 1249 /* Do not install synthetic routes */ 1250 if (RT->rt_state & RS_NET_SYN) 1251 return 0; 1252 1253 if (!(RT->rt_state & RS_IF)) { 1254 ags |= (AGS_GATEWAY | AGS_SUPPRESS | AGS_PROMOTE); 1255 1256 } else { 1257 /* Do not install routes for "external" remote interfaces. 1258 */ 1259 if (RT->rt_ifp != 0 && (RT->rt_ifp->int_state & IS_EXTERNAL)) 1260 return 0; 1261 1262 ags |= AGS_IF; 1263 1264 /* If it is not an interface, or an alias for an interface, 1265 * it must be a "gateway." 1266 * 1267 * If it is a "remote" interface, it is also a "gateway" to 1268 * the kernel if is not a alias. 1269 */ 1270 if (RT->rt_ifp == 0 1271 || ((RT->rt_ifp->int_state & IS_REMOTE) 1272 && RT->rt_ifp->int_metric == 0)) 1273 ags |= (AGS_GATEWAY | AGS_SUPPRESS | AGS_PROMOTE); 1274 } 1275 1276 if (RT->rt_state & RS_RDISC) 1277 ags |= AGS_CORS_GATE; 1278 1279 /* aggregate good routes without regard to their metric */ 1280 pref = 1; 1281 metric = RT->rt_metric; 1282 if (metric == HOPCNT_INFINITY) { 1283 /* if the route is dead, so try hard to aggregate. */ 1284 pref = HOPCNT_INFINITY; 1285 ags |= (AGS_FINE_GATE | AGS_SUPPRESS); 1286 } 1287 1288 ag_check(RT->rt_dst, RT->rt_mask, RT->rt_gate, 0, 1289 metric,pref, 0, 0, ags, kern_out); 1290 return 0; 1291 #undef RT 1292 } 1293 1294 1295 /* Update the kernel table to match the daemon table. 1296 */ 1297 static void 1298 fix_kern(void) 1299 { 1300 int i, flags; 1301 struct khash *k, **pk; 1302 1303 1304 need_kern = age_timer; 1305 1306 /* Walk daemon table, updating the copy of the kernel table. 1307 */ 1308 (void)rn_walktree(rhead, walk_kern, 0); 1309 ag_flush(0,0,kern_out); 1310 1311 for (i = 0; i < KHASH_SIZE; i++) { 1312 for (pk = &khash_bins[i]; (k = *pk) != 0; ) { 1313 /* Do not touch static routes */ 1314 if (k->k_state & KS_STATIC) { 1315 kern_check_static(k,0); 1316 pk = &k->k_next; 1317 continue; 1318 } 1319 1320 /* check hold on routes deleted by the operator */ 1321 if (k->k_keep > now.tv_sec) { 1322 LIM_SEC(need_kern, k->k_keep); 1323 k->k_state |= KS_DELETE; 1324 pk = &k->k_next; 1325 continue; 1326 } 1327 1328 if ((k->k_state & (KS_DELETE | KS_DYNAMIC)) 1329 == KS_DELETE) { 1330 if (!(k->k_state & KS_DELETED)) 1331 rtioctl(RTM_DELETE, 1332 k->k_dst, k->k_gate, k->k_mask, 1333 0, 0); 1334 *pk = k->k_next; 1335 free(k); 1336 continue; 1337 } 1338 1339 if (0 != (k->k_state&(KS_ADD|KS_CHANGE|KS_DEL_ADD))) { 1340 if (k->k_state & KS_DEL_ADD) { 1341 rtioctl(RTM_DELETE, 1342 k->k_dst,k->k_gate,k->k_mask, 1343 0, 0); 1344 k->k_state &= ~KS_DYNAMIC; 1345 } 1346 1347 flags = 0; 1348 if (0 != (k->k_state&(KS_GATEWAY|KS_DYNAMIC))) 1349 flags |= RTF_GATEWAY; 1350 1351 if (k->k_state & KS_ADD) { 1352 rtioctl(RTM_ADD, 1353 k->k_dst, k->k_gate, k->k_mask, 1354 k->k_metric, flags); 1355 } else if (k->k_state & KS_CHANGE) { 1356 rtioctl(RTM_CHANGE, 1357 k->k_dst,k->k_gate,k->k_mask, 1358 k->k_metric, flags); 1359 } 1360 k->k_state &= ~(KS_ADD|KS_CHANGE|KS_DEL_ADD); 1361 } 1362 1363 /* Mark this route to be deleted in the next cycle. 1364 * This deletes routes that disappear from the 1365 * daemon table, since the normal aging code 1366 * will clear the bit for routes that have not 1367 * disappeared from the daemon table. 1368 */ 1369 k->k_state |= KS_DELETE; 1370 pk = &k->k_next; 1371 } 1372 } 1373 } 1374 1375 1376 /* Delete a static route in the image of the kernel table. 1377 */ 1378 void 1379 del_static(naddr dst, 1380 naddr mask, 1381 int gone) 1382 { 1383 struct khash *k; 1384 struct rt_entry *rt; 1385 1386 /* Just mark it in the table to be deleted next time the kernel 1387 * table is updated. 1388 * If it has already been deleted, mark it as such, and set its 1389 * keep-timer so that it will not be deleted again for a while. 1390 * This lets the operator delete a route added by the daemon 1391 * and add a replacement. 1392 */ 1393 k = kern_find(dst, mask, 0); 1394 if (k != 0) { 1395 k->k_state &= ~(KS_STATIC | KS_DYNAMIC); 1396 k->k_state |= KS_DELETE; 1397 if (gone) { 1398 k->k_state |= KS_DELETED; 1399 k->k_keep = now.tv_sec + K_KEEP_LIM; 1400 } 1401 } 1402 1403 rt = rtget(dst, mask); 1404 if (rt != 0 && (rt->rt_state & RS_STATIC)) 1405 rtbad(rt); 1406 } 1407 1408 1409 /* Delete all routes generated from ICMP Redirects that use a given gateway, 1410 * as well as old redirected routes. 1411 */ 1412 void 1413 del_redirects(naddr bad_gate, 1414 time_t old) 1415 { 1416 int i; 1417 struct khash *k; 1418 1419 1420 for (i = 0; i < KHASH_SIZE; i++) { 1421 for (k = khash_bins[i]; k != 0; k = k->k_next) { 1422 if (!(k->k_state & KS_DYNAMIC) 1423 || (k->k_state & KS_STATIC)) 1424 continue; 1425 1426 if (k->k_gate != bad_gate 1427 && k->k_redirect_time > old 1428 && !supplier) 1429 continue; 1430 1431 k->k_state |= KS_DELETE; 1432 k->k_state &= ~KS_DYNAMIC; 1433 need_kern.tv_sec = now.tv_sec; 1434 trace_act("mark redirected %s --> %s for deletion\n", 1435 addrname(k->k_dst, k->k_mask, 0), 1436 naddr_ntoa(k->k_gate)); 1437 } 1438 } 1439 } 1440 1441 1442 /* Start the daemon tables. 1443 */ 1444 void 1445 rtinit(void) 1446 { 1447 extern int max_keylen; 1448 int i; 1449 struct ag_info *ag; 1450 1451 /* Initialize the radix trees */ 1452 max_keylen = sizeof(struct sockaddr_in); 1453 rn_init(); 1454 rn_inithead((void**)&rhead, 32); 1455 1456 /* mark all of the slots in the table free */ 1457 ag_avail = ag_slots; 1458 for (ag = ag_slots, i = 1; i < NUM_AG_SLOTS; i++) { 1459 ag->ag_fine = ag+1; 1460 ag++; 1461 } 1462 } 1463 1464 1465 #ifdef _HAVE_SIN_LEN 1466 static struct sockaddr_in dst_sock = {sizeof(dst_sock), AF_INET}; 1467 static struct sockaddr_in mask_sock = {sizeof(mask_sock), AF_INET}; 1468 #else 1469 static struct sockaddr_in_new dst_sock = {_SIN_ADDR_SIZE, AF_INET}; 1470 static struct sockaddr_in_new mask_sock = {_SIN_ADDR_SIZE, AF_INET}; 1471 #endif 1472 1473 1474 void 1475 set_need_flash(void) 1476 { 1477 if (!need_flash) { 1478 need_flash = 1; 1479 /* Do not send the flash update immediately. Wait a little 1480 * while to hear from other routers. 1481 */ 1482 no_flash.tv_sec = now.tv_sec + MIN_WAITTIME; 1483 } 1484 } 1485 1486 1487 /* Get a particular routing table entry 1488 */ 1489 struct rt_entry * 1490 rtget(naddr dst, naddr mask) 1491 { 1492 struct rt_entry *rt; 1493 1494 dst_sock.sin_addr.s_addr = dst; 1495 mask_sock.sin_addr.s_addr = mask; 1496 masktrim(&mask_sock); 1497 rt = (struct rt_entry *)rhead->rnh_lookup(&dst_sock,&mask_sock,rhead); 1498 if (!rt 1499 || rt->rt_dst != dst 1500 || rt->rt_mask != mask) 1501 return 0; 1502 1503 return rt; 1504 } 1505 1506 1507 /* Find a route to dst as the kernel would. 1508 */ 1509 struct rt_entry * 1510 rtfind(naddr dst) 1511 { 1512 dst_sock.sin_addr.s_addr = dst; 1513 return (struct rt_entry *)rhead->rnh_matchaddr(&dst_sock, rhead); 1514 } 1515 1516 1517 /* add a route to the table 1518 */ 1519 void 1520 rtadd(naddr dst, 1521 naddr mask, 1522 naddr gate, /* forward packets here */ 1523 naddr router, /* on the authority of this router */ 1524 int metric, 1525 u_short tag, 1526 u_int state, /* rs_state for the entry */ 1527 struct interface *ifp) 1528 { 1529 struct rt_entry *rt; 1530 naddr smask; 1531 int i; 1532 struct rt_spare *rts; 1533 1534 rt = (struct rt_entry *)rtmalloc(sizeof (*rt), "rtadd"); 1535 bzero(rt, sizeof(*rt)); 1536 for (rts = rt->rt_spares, i = NUM_SPARES; i != 0; i--, rts++) 1537 rts->rts_metric = HOPCNT_INFINITY; 1538 1539 rt->rt_nodes->rn_key = (caddr_t)&rt->rt_dst_sock; 1540 rt->rt_dst = dst; 1541 rt->rt_dst_sock.sin_family = AF_INET; 1542 #ifdef _HAVE_SIN_LEN 1543 rt->rt_dst_sock.sin_len = dst_sock.sin_len; 1544 #endif 1545 if (mask != HOST_MASK) { 1546 smask = std_mask(dst); 1547 if ((smask & ~mask) == 0 && mask > smask) 1548 state |= RS_SUBNET; 1549 } 1550 mask_sock.sin_addr.s_addr = mask; 1551 masktrim(&mask_sock); 1552 rt->rt_mask = mask; 1553 rt->rt_state = state; 1554 rt->rt_gate = gate; 1555 rt->rt_router = router; 1556 rt->rt_time = now.tv_sec; 1557 rt->rt_metric = metric; 1558 rt->rt_poison_metric = HOPCNT_INFINITY; 1559 rt->rt_tag = tag; 1560 rt->rt_ifp = ifp; 1561 rt->rt_seqno = update_seqno; 1562 1563 if (++total_routes == MAX_ROUTES) 1564 msglog("have maximum (%d) routes", total_routes); 1565 if (TRACEACTIONS) 1566 trace_add_del("Add", rt); 1567 1568 need_kern.tv_sec = now.tv_sec; 1569 set_need_flash(); 1570 1571 if (0 == rhead->rnh_addaddr(&rt->rt_dst_sock, &mask_sock, 1572 rhead, rt->rt_nodes)) { 1573 /* 1574 * This will happen if RIP1 and RIP2 routeds talk to one another and 1575 * there are variable subnets. This is only good for filling up your 1576 * syslog. -jkh 1577 */ 1578 #if 0 1579 msglog("rnh_addaddr() failed for %s mask=%#x", 1580 naddr_ntoa(dst), mask); 1581 #endif 1582 } 1583 } 1584 1585 1586 /* notice a changed route 1587 */ 1588 void 1589 rtchange(struct rt_entry *rt, 1590 u_int state, /* new state bits */ 1591 naddr gate, /* now forward packets here */ 1592 naddr router, /* on the authority of this router */ 1593 int metric, /* new metric */ 1594 u_short tag, 1595 struct interface *ifp, 1596 time_t new_time, 1597 char *label) 1598 { 1599 if (rt->rt_metric != metric) { 1600 /* Fix the kernel immediately if it seems the route 1601 * has gone bad, since there may be a working route that 1602 * aggregates this route. 1603 */ 1604 if (metric == HOPCNT_INFINITY) { 1605 need_kern.tv_sec = now.tv_sec; 1606 if (new_time >= now.tv_sec - EXPIRE_TIME) 1607 new_time = now.tv_sec - EXPIRE_TIME; 1608 } 1609 rt->rt_seqno = update_seqno; 1610 set_need_flash(); 1611 } 1612 1613 if (rt->rt_gate != gate) { 1614 need_kern.tv_sec = now.tv_sec; 1615 rt->rt_seqno = update_seqno; 1616 set_need_flash(); 1617 } 1618 1619 state |= (rt->rt_state & RS_SUBNET); 1620 1621 /* Keep various things from deciding ageless routes are stale. 1622 */ 1623 if (!AGE_RT(state, ifp)) 1624 new_time = now.tv_sec; 1625 1626 if (TRACEACTIONS) 1627 trace_change(rt, state, gate, router, metric, tag, ifp, 1628 new_time, 1629 label ? label : "Chg "); 1630 1631 rt->rt_state = state; 1632 rt->rt_gate = gate; 1633 rt->rt_router = router; 1634 rt->rt_metric = metric; 1635 rt->rt_tag = tag; 1636 rt->rt_ifp = ifp; 1637 rt->rt_time = new_time; 1638 } 1639 1640 1641 /* check for a better route among the spares 1642 */ 1643 static struct rt_spare * 1644 rts_better(struct rt_entry *rt) 1645 { 1646 struct rt_spare *rts, *rts1; 1647 int i; 1648 1649 /* find the best alternative among the spares */ 1650 rts = rt->rt_spares+1; 1651 for (i = NUM_SPARES, rts1 = rts+1; i > 2; i--, rts1++) { 1652 if (BETTER_LINK(rt,rts1,rts)) 1653 rts = rts1; 1654 } 1655 1656 return rts; 1657 } 1658 1659 1660 /* switch to a backup route 1661 */ 1662 void 1663 rtswitch(struct rt_entry *rt, 1664 struct rt_spare *rts) 1665 { 1666 struct rt_spare swap; 1667 char label[10]; 1668 1669 1670 /* Do not change permanent routes */ 1671 if (0 != (rt->rt_state & (RS_MHOME | RS_STATIC | RS_RDISC 1672 | RS_NET_SYN | RS_IF))) 1673 return; 1674 1675 /* find the best alternative among the spares */ 1676 if (rts == 0) 1677 rts = rts_better(rt); 1678 1679 /* Do not bother if it is not worthwhile. 1680 */ 1681 if (!BETTER_LINK(rt, rts, rt->rt_spares)) 1682 return; 1683 1684 swap = rt->rt_spares[0]; 1685 (void)sprintf(label, "Use #%d", rts - rt->rt_spares); 1686 rtchange(rt, rt->rt_state & ~(RS_NET_SYN | RS_RDISC), 1687 rts->rts_gate, rts->rts_router, rts->rts_metric, 1688 rts->rts_tag, rts->rts_ifp, rts->rts_time, label); 1689 *rts = swap; 1690 } 1691 1692 1693 void 1694 rtdelete(struct rt_entry *rt) 1695 { 1696 struct khash *k; 1697 1698 1699 if (TRACEACTIONS) 1700 trace_add_del("Del", rt); 1701 1702 k = kern_find(rt->rt_dst, rt->rt_mask, 0); 1703 if (k != 0) { 1704 k->k_state |= KS_DELETE; 1705 need_kern.tv_sec = now.tv_sec; 1706 } 1707 1708 dst_sock.sin_addr.s_addr = rt->rt_dst; 1709 mask_sock.sin_addr.s_addr = rt->rt_mask; 1710 masktrim(&mask_sock); 1711 if (rt != (struct rt_entry *)rhead->rnh_deladdr(&dst_sock, &mask_sock, 1712 rhead)) { 1713 msglog("rnh_deladdr() failed"); 1714 } else { 1715 free(rt); 1716 total_routes--; 1717 } 1718 } 1719 1720 1721 /* Get rid of a bad route, and try to switch to a replacement. 1722 */ 1723 void 1724 rtbad(struct rt_entry *rt) 1725 { 1726 /* Poison the route */ 1727 rtchange(rt, rt->rt_state & ~(RS_IF | RS_LOCAL | RS_STATIC), 1728 rt->rt_gate, rt->rt_router, HOPCNT_INFINITY, rt->rt_tag, 1729 0, rt->rt_time, 0); 1730 1731 rtswitch(rt, 0); 1732 } 1733 1734 1735 /* Junk a RS_NET_SYN or RS_LOCAL route, 1736 * unless it is needed by another interface. 1737 */ 1738 void 1739 rtbad_sub(struct rt_entry *rt) 1740 { 1741 struct interface *ifp, *ifp1; 1742 struct intnet *intnetp; 1743 u_int state; 1744 1745 1746 ifp1 = 0; 1747 state = 0; 1748 1749 if (rt->rt_state & RS_LOCAL) { 1750 /* Is this the route through loopback for the interface? 1751 * If so, see if it is used by any other interfaces, such 1752 * as a point-to-point interface with the same local address. 1753 */ 1754 for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) { 1755 /* Retain it if another interface needs it. 1756 */ 1757 if (ifp->int_addr == rt->rt_ifp->int_addr) { 1758 state |= RS_LOCAL; 1759 ifp1 = ifp; 1760 break; 1761 } 1762 } 1763 1764 } 1765 1766 if (!(state & RS_LOCAL)) { 1767 /* Retain RIPv1 logical network route if there is another 1768 * interface that justifies it. 1769 */ 1770 if (rt->rt_state & RS_NET_SYN) { 1771 for (ifp = ifnet; ifp != 0; ifp = ifp->int_next) { 1772 if ((ifp->int_state & IS_NEED_NET_SYN) 1773 && rt->rt_mask == ifp->int_std_mask 1774 && rt->rt_dst == ifp->int_std_addr) { 1775 state |= RS_NET_SYN; 1776 ifp1 = ifp; 1777 break; 1778 } 1779 } 1780 } 1781 1782 /* or if there is an authority route that needs it. */ 1783 for (intnetp = intnets; 1784 intnetp != 0; 1785 intnetp = intnetp->intnet_next) { 1786 if (intnetp->intnet_addr == rt->rt_dst 1787 && intnetp->intnet_mask == rt->rt_mask) { 1788 state |= (RS_NET_SYN | RS_NET_INT); 1789 break; 1790 } 1791 } 1792 } 1793 1794 if (ifp1 != 0 || (state & RS_NET_SYN)) { 1795 rtchange(rt, ((rt->rt_state & ~(RS_NET_SYN | RS_LOCAL)) 1796 | state), 1797 rt->rt_gate, rt->rt_router, rt->rt_metric, 1798 rt->rt_tag, ifp1, rt->rt_time, 0); 1799 } else { 1800 rtbad(rt); 1801 } 1802 } 1803 1804 1805 /* Called while walking the table looking for sick interfaces 1806 * or after a time change. 1807 */ 1808 /* ARGSUSED */ 1809 int 1810 walk_bad(struct radix_node *rn, 1811 struct walkarg *w) 1812 { 1813 #define RT ((struct rt_entry *)rn) 1814 struct rt_spare *rts; 1815 int i; 1816 time_t new_time; 1817 1818 1819 /* fix any spare routes through the interface 1820 */ 1821 rts = RT->rt_spares; 1822 for (i = NUM_SPARES; i != 1; i--) { 1823 rts++; 1824 1825 if (rts->rts_ifp != 0 1826 && (rts->rts_ifp->int_state & IS_BROKE)) { 1827 /* mark the spare route to be deleted immediately */ 1828 new_time = rts->rts_time; 1829 if (new_time >= now_garbage) 1830 new_time = now_garbage-1; 1831 trace_upslot(RT, rts, rts->rts_gate, 1832 rts->rts_router, 0, 1833 HOPCNT_INFINITY, rts->rts_tag, 1834 new_time); 1835 rts->rts_ifp = 0; 1836 rts->rts_metric = HOPCNT_INFINITY; 1837 rts->rts_time = new_time; 1838 } 1839 } 1840 1841 /* Deal with the main route 1842 */ 1843 /* finished if it has been handled before or if its interface is ok 1844 */ 1845 if (RT->rt_ifp == 0 || !(RT->rt_ifp->int_state & IS_BROKE)) 1846 return 0; 1847 1848 /* Bad routes for other than interfaces are easy. 1849 */ 1850 if (0 == (RT->rt_state & (RS_IF | RS_NET_SYN | RS_LOCAL))) { 1851 rtbad(RT); 1852 return 0; 1853 } 1854 1855 rtbad_sub(RT); 1856 return 0; 1857 #undef RT 1858 } 1859 1860 1861 /* Check the age of an individual route. 1862 */ 1863 /* ARGSUSED */ 1864 static int 1865 walk_age(struct radix_node *rn, 1866 struct walkarg *w) 1867 { 1868 #define RT ((struct rt_entry *)rn) 1869 struct interface *ifp; 1870 struct rt_spare *rts; 1871 int i; 1872 1873 1874 /* age all of the spare routes, including the primary route 1875 * currently in use 1876 */ 1877 rts = RT->rt_spares; 1878 for (i = NUM_SPARES; i != 0; i--, rts++) { 1879 1880 ifp = rts->rts_ifp; 1881 if (i == NUM_SPARES) { 1882 if (!AGE_RT(RT->rt_state, ifp)) { 1883 /* Keep various things from deciding ageless 1884 * routes are stale 1885 */ 1886 rts->rts_time = now.tv_sec; 1887 continue; 1888 } 1889 1890 /* forget RIP routes after RIP has been turned off. 1891 */ 1892 if (rip_sock < 0) { 1893 rtdelete(RT); 1894 return 0; 1895 } 1896 } 1897 1898 /* age failing routes 1899 */ 1900 if (age_bad_gate == rts->rts_gate 1901 && rts->rts_time >= now_stale) { 1902 rts->rts_time -= SUPPLY_INTERVAL; 1903 } 1904 1905 /* trash the spare routes when they go bad */ 1906 if (rts->rts_metric < HOPCNT_INFINITY 1907 && now_garbage > rts->rts_time) { 1908 trace_upslot(RT, rts, rts->rts_gate, 1909 rts->rts_router, rts->rts_ifp, 1910 HOPCNT_INFINITY, rts->rts_tag, 1911 rts->rts_time); 1912 rts->rts_metric = HOPCNT_INFINITY; 1913 } 1914 } 1915 1916 1917 /* finished if the active route is still fresh */ 1918 if (now_stale <= RT->rt_time) 1919 return 0; 1920 1921 /* try to switch to an alternative */ 1922 rtswitch(RT, 0); 1923 1924 /* Delete a dead route after it has been publically mourned. */ 1925 if (now_garbage > RT->rt_time) { 1926 rtdelete(RT); 1927 return 0; 1928 } 1929 1930 /* Start poisoning a bad route before deleting it. */ 1931 if (now.tv_sec - RT->rt_time > EXPIRE_TIME) 1932 rtchange(RT, RT->rt_state, RT->rt_gate, RT->rt_router, 1933 HOPCNT_INFINITY, RT->rt_tag, RT->rt_ifp, 1934 RT->rt_time, 0); 1935 return 0; 1936 } 1937 1938 1939 /* Watch for dead routes and interfaces. 1940 */ 1941 void 1942 age(naddr bad_gate) 1943 { 1944 struct interface *ifp; 1945 1946 1947 age_timer.tv_sec = now.tv_sec + (rip_sock < 0 1948 ? NEVER 1949 : SUPPLY_INTERVAL); 1950 1951 for (ifp = ifnet; ifp; ifp = ifp->int_next) { 1952 /* Check for dead IS_REMOTE interfaces by timing their 1953 * transmissions. 1954 */ 1955 if ((ifp->int_state & IS_REMOTE) 1956 && !(ifp->int_state & IS_PASSIVE) 1957 && (ifp->int_state & IS_ACTIVE)) { 1958 LIM_SEC(age_timer, now.tv_sec+SUPPLY_INTERVAL); 1959 1960 if (now.tv_sec - ifp->int_act_time > EXPIRE_TIME 1961 && !(ifp->int_state & IS_BROKE)) { 1962 msglog("remote interface %s to %s timed out" 1963 "--turned off", 1964 ifp->int_name, 1965 naddr_ntoa(ifp->int_addr)); 1966 if_bad(ifp); 1967 } 1968 } 1969 } 1970 1971 /* Age routes. */ 1972 age_bad_gate = bad_gate; 1973 (void)rn_walktree(rhead, walk_age, 0); 1974 1975 /* Update the kernel routing table. */ 1976 fix_kern(); 1977 } 1978