1 /* 2 * Copyright (c) 1988, 1989, 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 acknowledgment: 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 * @(#)radix.c 8.4 (Berkeley) 11/2/94 34 * 35 * $FreeBSD$ 36 */ 37 38 /* 39 * Routines to build and maintain radix trees for routing lookups. 40 */ 41 42 #include "defs.h" 43 44 #if !defined(sgi) && !defined(__NetBSD__) 45 static char sccsid[] __attribute__((unused)) = "@(#)rdisc.c 8.1 (Berkeley) x/y/95"; 46 #elif defined(__NetBSD__) 47 __RCSID("$NetBSD$"); 48 #endif 49 #ident "$FreeBSD$" 50 51 #define log(x, msg) syslog(x, msg) 52 #define panic(s) {log(LOG_ERR,s); exit(1);} 53 #define min(a,b) (((a)<(b))?(a):(b)) 54 55 int max_keylen; 56 struct radix_mask *rn_mkfreelist; 57 struct radix_node_head *mask_rnhead; 58 static char *addmask_key; 59 static char normal_chars[] = {0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1}; 60 static char *rn_zeros, *rn_ones; 61 62 #define rn_masktop (mask_rnhead->rnh_treetop) 63 #undef Bcmp 64 #define Bcmp(a, b, l) (l == 0 ? 0 \ 65 : memcmp((caddr_t)(a), (caddr_t)(b), (size_t)l)) 66 67 static int rn_satisfies_leaf(char *, struct radix_node *, int); 68 69 /* 70 * The data structure for the keys is a radix tree with one way 71 * branching removed. The index rn_b at an internal node n represents a bit 72 * position to be tested. The tree is arranged so that all descendants 73 * of a node n have keys whose bits all agree up to position rn_b - 1. 74 * (We say the index of n is rn_b.) 75 * 76 * There is at least one descendant which has a one bit at position rn_b, 77 * and at least one with a zero there. 78 * 79 * A route is determined by a pair of key and mask. We require that the 80 * bit-wise logical and of the key and mask to be the key. 81 * We define the index of a route to associated with the mask to be 82 * the first bit number in the mask where 0 occurs (with bit number 0 83 * representing the highest order bit). 84 * 85 * We say a mask is normal if every bit is 0, past the index of the mask. 86 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_b, 87 * and m is a normal mask, then the route applies to every descendant of n. 88 * If the index(m) < rn_b, this implies the trailing last few bits of k 89 * before bit b are all 0, (and hence consequently true of every descendant 90 * of n), so the route applies to all descendants of the node as well. 91 * 92 * Similar logic shows that a non-normal mask m such that 93 * index(m) <= index(n) could potentially apply to many children of n. 94 * Thus, for each non-host route, we attach its mask to a list at an internal 95 * node as high in the tree as we can go. 96 * 97 * The present version of the code makes use of normal routes in short- 98 * circuiting an explict mask and compare operation when testing whether 99 * a key satisfies a normal route, and also in remembering the unique leaf 100 * that governs a subtree. 101 */ 102 103 struct radix_node * 104 rn_search(void *v_arg, 105 struct radix_node *head) 106 { 107 struct radix_node *x; 108 caddr_t v; 109 110 for (x = head, v = v_arg; x->rn_b >= 0;) { 111 if (x->rn_bmask & v[x->rn_off]) 112 x = x->rn_r; 113 else 114 x = x->rn_l; 115 } 116 return (x); 117 } 118 119 struct radix_node * 120 rn_search_m(void *v_arg, 121 struct radix_node *head, 122 void *m_arg) 123 { 124 struct radix_node *x; 125 caddr_t v = v_arg, m = m_arg; 126 127 for (x = head; x->rn_b >= 0;) { 128 if ((x->rn_bmask & m[x->rn_off]) && 129 (x->rn_bmask & v[x->rn_off])) 130 x = x->rn_r; 131 else 132 x = x->rn_l; 133 } 134 return x; 135 } 136 137 int 138 rn_refines(void* m_arg, void *n_arg) 139 { 140 caddr_t m = m_arg, n = n_arg; 141 caddr_t lim, lim2 = lim = n + *(u_char *)n; 142 int longer = (*(u_char *)n++) - (int)(*(u_char *)m++); 143 int masks_are_equal = 1; 144 145 if (longer > 0) 146 lim -= longer; 147 while (n < lim) { 148 if (*n & ~(*m)) 149 return 0; 150 if (*n++ != *m++) 151 masks_are_equal = 0; 152 } 153 while (n < lim2) 154 if (*n++) 155 return 0; 156 if (masks_are_equal && (longer < 0)) 157 for (lim2 = m - longer; m < lim2; ) 158 if (*m++) 159 return 1; 160 return (!masks_are_equal); 161 } 162 163 struct radix_node * 164 rn_lookup(void *v_arg, void *m_arg, struct radix_node_head *head) 165 { 166 struct radix_node *x; 167 caddr_t netmask = 0; 168 169 if (m_arg) { 170 if ((x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_off)) == 0) 171 return (0); 172 netmask = x->rn_key; 173 } 174 x = rn_match(v_arg, head); 175 if (x && netmask) { 176 while (x && x->rn_mask != netmask) 177 x = x->rn_dupedkey; 178 } 179 return x; 180 } 181 182 static int 183 rn_satisfies_leaf(char *trial, 184 struct radix_node *leaf, 185 int skip) 186 { 187 char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask; 188 char *cplim; 189 int length = min(*(u_char *)cp, *(u_char *)cp2); 190 191 if (cp3 == 0) 192 cp3 = rn_ones; 193 else 194 length = min(length, *(u_char *)cp3); 195 cplim = cp + length; cp3 += skip; cp2 += skip; 196 for (cp += skip; cp < cplim; cp++, cp2++, cp3++) 197 if ((*cp ^ *cp2) & *cp3) 198 return 0; 199 return 1; 200 } 201 202 struct radix_node * 203 rn_match(void *v_arg, 204 struct radix_node_head *head) 205 { 206 caddr_t v = v_arg; 207 struct radix_node *t = head->rnh_treetop, *x; 208 caddr_t cp = v, cp2; 209 caddr_t cplim; 210 struct radix_node *saved_t, *top = t; 211 int off = t->rn_off, vlen = *(u_char *)cp, matched_off; 212 int test, b, rn_b; 213 214 /* 215 * Open code rn_search(v, top) to avoid overhead of extra 216 * subroutine call. 217 */ 218 for (; t->rn_b >= 0; ) { 219 if (t->rn_bmask & cp[t->rn_off]) 220 t = t->rn_r; 221 else 222 t = t->rn_l; 223 } 224 /* 225 * See if we match exactly as a host destination 226 * or at least learn how many bits match, for normal mask finesse. 227 * 228 * It doesn't hurt us to limit how many bytes to check 229 * to the length of the mask, since if it matches we had a genuine 230 * match and the leaf we have is the most specific one anyway; 231 * if it didn't match with a shorter length it would fail 232 * with a long one. This wins big for class B&C netmasks which 233 * are probably the most common case... 234 */ 235 if (t->rn_mask) 236 vlen = *(u_char *)t->rn_mask; 237 cp += off; cp2 = t->rn_key + off; cplim = v + vlen; 238 for (; cp < cplim; cp++, cp2++) 239 if (*cp != *cp2) 240 goto on1; 241 /* 242 * This extra grot is in case we are explicitly asked 243 * to look up the default. Ugh! 244 * Or 255.255.255.255 245 * 246 * In this case, we have a complete match of the key. Unless 247 * the node is one of the roots, we are finished. 248 * If it is the zeros root, then take what we have, prefering 249 * any real data. 250 * If it is the ones root, then pretend the target key was followed 251 * by a byte of zeros. 252 */ 253 if (!(t->rn_flags & RNF_ROOT)) 254 return t; /* not a root */ 255 if (t->rn_dupedkey) { 256 t = t->rn_dupedkey; 257 return t; /* have some real data */ 258 } 259 if (*(cp-1) == 0) 260 return t; /* not the ones root */ 261 b = 0; /* fake a zero after 255.255.255.255 */ 262 goto on2; 263 on1: 264 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */ 265 for (b = 7; (test >>= 1) > 0;) 266 b--; 267 on2: 268 matched_off = cp - v; 269 b += matched_off << 3; 270 rn_b = -1 - b; 271 /* 272 * If there is a host route in a duped-key chain, it will be first. 273 */ 274 if ((saved_t = t)->rn_mask == 0) 275 t = t->rn_dupedkey; 276 for (; t; t = t->rn_dupedkey) { 277 /* 278 * Even if we don't match exactly as a host, 279 * we may match if the leaf we wound up at is 280 * a route to a net. 281 */ 282 if (t->rn_flags & RNF_NORMAL) { 283 if (rn_b <= t->rn_b) 284 return t; 285 } else if (rn_satisfies_leaf(v, t, matched_off)) { 286 return t; 287 } 288 } 289 t = saved_t; 290 /* start searching up the tree */ 291 do { 292 struct radix_mask *m; 293 t = t->rn_p; 294 if ((m = t->rn_mklist)) { 295 /* 296 * If non-contiguous masks ever become important 297 * we can restore the masking and open coding of 298 * the search and satisfaction test and put the 299 * calculation of "off" back before the "do". 300 */ 301 do { 302 if (m->rm_flags & RNF_NORMAL) { 303 if (rn_b <= m->rm_b) 304 return (m->rm_leaf); 305 } else { 306 off = min(t->rn_off, matched_off); 307 x = rn_search_m(v, t, m->rm_mask); 308 while (x && x->rn_mask != m->rm_mask) 309 x = x->rn_dupedkey; 310 if (x && rn_satisfies_leaf(v, x, off)) 311 return x; 312 } 313 } while ((m = m->rm_mklist)); 314 } 315 } while (t != top); 316 return 0; 317 } 318 319 #ifdef RN_DEBUG 320 int rn_nodenum; 321 struct radix_node *rn_clist; 322 int rn_saveinfo; 323 int rn_debug = 1; 324 #endif 325 326 struct radix_node * 327 rn_newpair(void *v, int b, struct radix_node nodes[2]) 328 { 329 struct radix_node *tt = nodes, *t = tt + 1; 330 t->rn_b = b; t->rn_bmask = 0x80 >> (b & 7); 331 t->rn_l = tt; t->rn_off = b >> 3; 332 tt->rn_b = -1; tt->rn_key = (caddr_t)v; tt->rn_p = t; 333 tt->rn_flags = t->rn_flags = RNF_ACTIVE; 334 #ifdef RN_DEBUG 335 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 336 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 337 #endif 338 return t; 339 } 340 341 struct radix_node * 342 rn_insert(void* v_arg, 343 struct radix_node_head *head, 344 int *dupentry, 345 struct radix_node nodes[2]) 346 { 347 caddr_t v = v_arg; 348 struct radix_node *top = head->rnh_treetop; 349 int head_off = top->rn_off, vlen = (int)*((u_char *)v); 350 struct radix_node *t = rn_search(v_arg, top); 351 caddr_t cp = v + head_off; 352 int b; 353 struct radix_node *tt; 354 355 /* 356 * Find first bit at which v and t->rn_key differ 357 */ 358 { 359 caddr_t cp2 = t->rn_key + head_off; 360 int cmp_res; 361 caddr_t cplim = v + vlen; 362 363 while (cp < cplim) 364 if (*cp2++ != *cp++) 365 goto on1; 366 /* handle adding 255.255.255.255 */ 367 if (!(t->rn_flags & RNF_ROOT) || *(cp2-1) == 0) { 368 *dupentry = 1; 369 return t; 370 } 371 on1: 372 *dupentry = 0; 373 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff; 374 for (b = (cp - v) << 3; cmp_res; b--) 375 cmp_res >>= 1; 376 } 377 { 378 struct radix_node *p, *x = top; 379 cp = v; 380 do { 381 p = x; 382 if (cp[x->rn_off] & x->rn_bmask) 383 x = x->rn_r; 384 else x = x->rn_l; 385 } while ((unsigned)b > (unsigned)x->rn_b); 386 #ifdef RN_DEBUG 387 if (rn_debug) 388 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p); 389 #endif 390 t = rn_newpair(v_arg, b, nodes); tt = t->rn_l; 391 if ((cp[p->rn_off] & p->rn_bmask) == 0) 392 p->rn_l = t; 393 else 394 p->rn_r = t; 395 x->rn_p = t; t->rn_p = p; /* frees x, p as temp vars below */ 396 if ((cp[t->rn_off] & t->rn_bmask) == 0) { 397 t->rn_r = x; 398 } else { 399 t->rn_r = tt; t->rn_l = x; 400 } 401 #ifdef RN_DEBUG 402 if (rn_debug) 403 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p); 404 #endif 405 } 406 return (tt); 407 } 408 409 struct radix_node * 410 rn_addmask(void *n_arg, int search, int skip) 411 { 412 caddr_t netmask = (caddr_t)n_arg; 413 struct radix_node *x; 414 caddr_t cp, cplim; 415 int b = 0, mlen, j; 416 int maskduplicated, m0, isnormal; 417 struct radix_node *saved_x; 418 static int last_zeroed = 0; 419 420 if ((mlen = *(u_char *)netmask) > max_keylen) 421 mlen = max_keylen; 422 if (skip == 0) 423 skip = 1; 424 if (mlen <= skip) 425 return (mask_rnhead->rnh_nodes); 426 if (skip > 1) 427 Bcopy(rn_ones + 1, addmask_key + 1, skip - 1); 428 if ((m0 = mlen) > skip) 429 Bcopy(netmask + skip, addmask_key + skip, mlen - skip); 430 /* 431 * Trim trailing zeroes. 432 */ 433 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;) 434 cp--; 435 mlen = cp - addmask_key; 436 if (mlen <= skip) { 437 if (m0 >= last_zeroed) 438 last_zeroed = mlen; 439 return (mask_rnhead->rnh_nodes); 440 } 441 if (m0 < last_zeroed) 442 Bzero(addmask_key + m0, last_zeroed - m0); 443 *addmask_key = last_zeroed = mlen; 444 x = rn_search(addmask_key, rn_masktop); 445 if (Bcmp(addmask_key, x->rn_key, mlen) != 0) 446 x = 0; 447 if (x || search) 448 return (x); 449 x = (struct radix_node *)rtmalloc(max_keylen + 2*sizeof(*x), 450 "rn_addmask"); 451 saved_x = x; 452 Bzero(x, max_keylen + 2 * sizeof (*x)); 453 netmask = cp = (caddr_t)(x + 2); 454 Bcopy(addmask_key, cp, mlen); 455 x = rn_insert(cp, mask_rnhead, &maskduplicated, x); 456 if (maskduplicated) { 457 log(LOG_ERR, "rn_addmask: mask impossibly already in tree"); 458 Free(saved_x); 459 return (x); 460 } 461 /* 462 * Calculate index of mask, and check for normalcy. 463 */ 464 cplim = netmask + mlen; isnormal = 1; 465 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;) 466 cp++; 467 if (cp != cplim) { 468 for (j = 0x80; (j & *cp) != 0; j >>= 1) 469 b++; 470 if (*cp != normal_chars[b] || cp != (cplim - 1)) 471 isnormal = 0; 472 } 473 b += (cp - netmask) << 3; 474 x->rn_b = -1 - b; 475 if (isnormal) 476 x->rn_flags |= RNF_NORMAL; 477 return (x); 478 } 479 480 static int /* XXX: arbitrary ordering for non-contiguous masks */ 481 rn_lexobetter(void *m_arg, void *n_arg) 482 { 483 u_char *mp = m_arg, *np = n_arg, *lim; 484 485 if (*mp > *np) 486 return 1; /* not really, but need to check longer one first */ 487 if (*mp == *np) 488 for (lim = mp + *mp; mp < lim;) 489 if (*mp++ > *np++) 490 return 1; 491 return 0; 492 } 493 494 static struct radix_mask * 495 rn_new_radix_mask(struct radix_node *tt, 496 struct radix_mask *next) 497 { 498 struct radix_mask *m; 499 500 MKGet(m); 501 if (m == 0) { 502 log(LOG_ERR, "Mask for route not entered\n"); 503 return (0); 504 } 505 Bzero(m, sizeof *m); 506 m->rm_b = tt->rn_b; 507 m->rm_flags = tt->rn_flags; 508 if (tt->rn_flags & RNF_NORMAL) 509 m->rm_leaf = tt; 510 else 511 m->rm_mask = tt->rn_mask; 512 m->rm_mklist = next; 513 tt->rn_mklist = m; 514 return m; 515 } 516 517 struct radix_node * 518 rn_addroute(void *v_arg, 519 void *n_arg, 520 struct radix_node_head *head, 521 struct radix_node treenodes[2]) 522 { 523 caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg; 524 struct radix_node *t, *x = 0, *tt; 525 struct radix_node *saved_tt, *top = head->rnh_treetop; 526 short b = 0, b_leaf = 0; 527 int keyduplicated; 528 caddr_t mmask; 529 struct radix_mask *m, **mp; 530 531 /* 532 * In dealing with non-contiguous masks, there may be 533 * many different routes which have the same mask. 534 * We will find it useful to have a unique pointer to 535 * the mask to speed avoiding duplicate references at 536 * nodes and possibly save time in calculating indices. 537 */ 538 if (netmask) { 539 if ((x = rn_addmask(netmask, 0, top->rn_off)) == 0) 540 return (0); 541 b_leaf = x->rn_b; 542 b = -1 - x->rn_b; 543 netmask = x->rn_key; 544 } 545 /* 546 * Deal with duplicated keys: attach node to previous instance 547 */ 548 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes); 549 if (keyduplicated) { 550 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) { 551 if (tt->rn_mask == netmask) 552 return (0); 553 if (netmask == 0 || 554 (tt->rn_mask && 555 ((b_leaf < tt->rn_b) || /* index(netmask) > node */ 556 rn_refines(netmask, tt->rn_mask) || 557 rn_lexobetter(netmask, tt->rn_mask)))) 558 break; 559 } 560 /* 561 * If the mask is not duplicated, we wouldn't 562 * find it among possible duplicate key entries 563 * anyway, so the above test doesn't hurt. 564 * 565 * We sort the masks for a duplicated key the same way as 566 * in a masklist -- most specific to least specific. 567 * This may require the unfortunate nuisance of relocating 568 * the head of the list. 569 */ 570 if (tt == saved_tt) { 571 struct radix_node *xx = x; 572 /* link in at head of list */ 573 (tt = treenodes)->rn_dupedkey = t; 574 tt->rn_flags = t->rn_flags; 575 tt->rn_p = x = t->rn_p; 576 if (x->rn_l == t) x->rn_l = tt; else x->rn_r = tt; 577 saved_tt = tt; x = xx; 578 } else { 579 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey; 580 t->rn_dupedkey = tt; 581 } 582 #ifdef RN_DEBUG 583 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 584 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 585 #endif 586 tt->rn_key = (caddr_t) v; 587 tt->rn_b = -1; 588 tt->rn_flags = RNF_ACTIVE; 589 } 590 /* 591 * Put mask in tree. 592 */ 593 if (netmask) { 594 tt->rn_mask = netmask; 595 tt->rn_b = x->rn_b; 596 tt->rn_flags |= x->rn_flags & RNF_NORMAL; 597 } 598 t = saved_tt->rn_p; 599 if (keyduplicated) 600 goto on2; 601 b_leaf = -1 - t->rn_b; 602 if (t->rn_r == saved_tt) x = t->rn_l; else x = t->rn_r; 603 /* Promote general routes from below */ 604 if (x->rn_b < 0) { 605 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey) 606 if (x->rn_mask && (x->rn_b >= b_leaf) && x->rn_mklist == 0) { 607 if ((*mp = m = rn_new_radix_mask(x, 0))) 608 mp = &m->rm_mklist; 609 } 610 } else if (x->rn_mklist) { 611 /* 612 * Skip over masks whose index is > that of new node 613 */ 614 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 615 if (m->rm_b >= b_leaf) 616 break; 617 t->rn_mklist = m; *mp = 0; 618 } 619 on2: 620 /* Add new route to highest possible ancestor's list */ 621 if ((netmask == 0) || (b > t->rn_b )) 622 return tt; /* can't lift at all */ 623 b_leaf = tt->rn_b; 624 do { 625 x = t; 626 t = t->rn_p; 627 } while (b <= t->rn_b && x != top); 628 /* 629 * Search through routes associated with node to 630 * insert new route according to index. 631 * Need same criteria as when sorting dupedkeys to avoid 632 * double loop on deletion. 633 */ 634 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) { 635 if (m->rm_b < b_leaf) 636 continue; 637 if (m->rm_b > b_leaf) 638 break; 639 if (m->rm_flags & RNF_NORMAL) { 640 mmask = m->rm_leaf->rn_mask; 641 if (tt->rn_flags & RNF_NORMAL) { 642 log(LOG_ERR, 643 "Non-unique normal route, mask not entered"); 644 return tt; 645 } 646 } else 647 mmask = m->rm_mask; 648 if (mmask == netmask) { 649 m->rm_refs++; 650 tt->rn_mklist = m; 651 return tt; 652 } 653 if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask)) 654 break; 655 } 656 *mp = rn_new_radix_mask(tt, *mp); 657 return tt; 658 } 659 660 struct radix_node * 661 rn_delete(void *v_arg, 662 void *netmask_arg, 663 struct radix_node_head *head) 664 { 665 struct radix_node *t, *p, *x, *tt; 666 struct radix_mask *m, *saved_m, **mp; 667 struct radix_node *dupedkey, *saved_tt, *top; 668 caddr_t v, netmask; 669 int b, head_off, vlen; 670 671 v = v_arg; 672 netmask = netmask_arg; 673 x = head->rnh_treetop; 674 tt = rn_search(v, x); 675 head_off = x->rn_off; 676 vlen = *(u_char *)v; 677 saved_tt = tt; 678 top = x; 679 if (tt == 0 || 680 Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off)) 681 return (0); 682 /* 683 * Delete our route from mask lists. 684 */ 685 if (netmask) { 686 if ((x = rn_addmask(netmask, 1, head_off)) == 0) 687 return (0); 688 netmask = x->rn_key; 689 while (tt->rn_mask != netmask) 690 if ((tt = tt->rn_dupedkey) == 0) 691 return (0); 692 } 693 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0) 694 goto on1; 695 if (tt->rn_flags & RNF_NORMAL) { 696 if (m->rm_leaf != tt || m->rm_refs > 0) { 697 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 698 return 0; /* dangling ref could cause disaster */ 699 } 700 } else { 701 if (m->rm_mask != tt->rn_mask) { 702 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 703 goto on1; 704 } 705 if (--m->rm_refs >= 0) 706 goto on1; 707 } 708 b = -1 - tt->rn_b; 709 t = saved_tt->rn_p; 710 if (b > t->rn_b) 711 goto on1; /* Wasn't lifted at all */ 712 do { 713 x = t; 714 t = t->rn_p; 715 } while (b <= t->rn_b && x != top); 716 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 717 if (m == saved_m) { 718 *mp = m->rm_mklist; 719 MKFree(m); 720 break; 721 } 722 if (m == 0) { 723 log(LOG_ERR, "rn_delete: couldn't find our annotation\n"); 724 if (tt->rn_flags & RNF_NORMAL) 725 return (0); /* Dangling ref to us */ 726 } 727 on1: 728 /* 729 * Eliminate us from tree 730 */ 731 if (tt->rn_flags & RNF_ROOT) 732 return (0); 733 #ifdef RN_DEBUG 734 /* Get us out of the creation list */ 735 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {} 736 if (t) t->rn_ybro = tt->rn_ybro; 737 #endif 738 t = tt->rn_p; 739 if ((dupedkey = saved_tt->rn_dupedkey)) { 740 if (tt == saved_tt) { 741 x = dupedkey; x->rn_p = t; 742 if (t->rn_l == tt) t->rn_l = x; else t->rn_r = x; 743 } else { 744 for (x = p = saved_tt; p && p->rn_dupedkey != tt;) 745 p = p->rn_dupedkey; 746 if (p) p->rn_dupedkey = tt->rn_dupedkey; 747 else log(LOG_ERR, "rn_delete: couldn't find us\n"); 748 } 749 t = tt + 1; 750 if (t->rn_flags & RNF_ACTIVE) { 751 #ifndef RN_DEBUG 752 *++x = *t; p = t->rn_p; 753 #else 754 b = t->rn_info; *++x = *t; t->rn_info = b; p = t->rn_p; 755 #endif 756 if (p->rn_l == t) p->rn_l = x; else p->rn_r = x; 757 x->rn_l->rn_p = x; x->rn_r->rn_p = x; 758 } 759 goto out; 760 } 761 if (t->rn_l == tt) x = t->rn_r; else x = t->rn_l; 762 p = t->rn_p; 763 if (p->rn_r == t) p->rn_r = x; else p->rn_l = x; 764 x->rn_p = p; 765 /* 766 * Demote routes attached to us. 767 */ 768 if (t->rn_mklist) { 769 if (x->rn_b >= 0) { 770 for (mp = &x->rn_mklist; (m = *mp);) 771 mp = &m->rm_mklist; 772 *mp = t->rn_mklist; 773 } else { 774 /* If there are any key,mask pairs in a sibling 775 duped-key chain, some subset will appear sorted 776 in the same order attached to our mklist */ 777 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey) 778 if (m == x->rn_mklist) { 779 struct radix_mask *mm = m->rm_mklist; 780 x->rn_mklist = 0; 781 if (--(m->rm_refs) < 0) 782 MKFree(m); 783 m = mm; 784 } 785 if (m) 786 syslog(LOG_ERR, "%s 0x%lx at 0x%lx\n", 787 "rn_delete: Orphaned Mask", 788 (unsigned long)m, 789 (unsigned long)x); 790 } 791 } 792 /* 793 * We may be holding an active internal node in the tree. 794 */ 795 x = tt + 1; 796 if (t != x) { 797 #ifndef RN_DEBUG 798 *t = *x; 799 #else 800 b = t->rn_info; *t = *x; t->rn_info = b; 801 #endif 802 t->rn_l->rn_p = t; t->rn_r->rn_p = t; 803 p = x->rn_p; 804 if (p->rn_l == x) p->rn_l = t; else p->rn_r = t; 805 } 806 out: 807 tt->rn_flags &= ~RNF_ACTIVE; 808 tt[1].rn_flags &= ~RNF_ACTIVE; 809 return (tt); 810 } 811 812 int 813 rn_walktree(struct radix_node_head *h, 814 int (*f)(struct radix_node *, struct walkarg *), 815 struct walkarg *w) 816 { 817 int error; 818 struct radix_node *base, *next; 819 struct radix_node *rn = h->rnh_treetop; 820 /* 821 * This gets complicated because we may delete the node 822 * while applying the function f to it, so we need to calculate 823 * the successor node in advance. 824 */ 825 /* First time through node, go left */ 826 while (rn->rn_b >= 0) 827 rn = rn->rn_l; 828 for (;;) { 829 base = rn; 830 /* If at right child go back up, otherwise, go right */ 831 while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0) 832 rn = rn->rn_p; 833 /* Find the next *leaf* since next node might vanish, too */ 834 for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;) 835 rn = rn->rn_l; 836 next = rn; 837 /* Process leaves */ 838 while ((rn = base)) { 839 base = rn->rn_dupedkey; 840 if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w))) 841 return (error); 842 } 843 rn = next; 844 if (rn->rn_flags & RNF_ROOT) 845 return (0); 846 } 847 /* NOTREACHED */ 848 } 849 850 int 851 rn_inithead(void **head, int off) 852 { 853 struct radix_node_head *rnh; 854 struct radix_node *t, *tt, *ttt; 855 if (*head) 856 return (1); 857 rnh = (struct radix_node_head *)rtmalloc(sizeof(*rnh), "rn_inithead"); 858 Bzero(rnh, sizeof (*rnh)); 859 *head = rnh; 860 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes); 861 ttt = rnh->rnh_nodes + 2; 862 t->rn_r = ttt; 863 t->rn_p = t; 864 tt = t->rn_l; 865 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE; 866 tt->rn_b = -1 - off; 867 *ttt = *tt; 868 ttt->rn_key = rn_ones; 869 rnh->rnh_addaddr = rn_addroute; 870 rnh->rnh_deladdr = rn_delete; 871 rnh->rnh_matchaddr = rn_match; 872 rnh->rnh_lookup = rn_lookup; 873 rnh->rnh_walktree = rn_walktree; 874 rnh->rnh_treetop = t; 875 return (1); 876 } 877 878 void 879 rn_init(void) 880 { 881 char *cp, *cplim; 882 if (max_keylen == 0) { 883 printf("rn_init: radix functions require max_keylen be set\n"); 884 return; 885 } 886 rn_zeros = (char *)rtmalloc(3 * max_keylen, "rn_init"); 887 Bzero(rn_zeros, 3 * max_keylen); 888 rn_ones = cp = rn_zeros + max_keylen; 889 addmask_key = cplim = rn_ones + max_keylen; 890 while (cp < cplim) 891 *cp++ = -1; 892 if (rn_inithead((void **)&mask_rnhead, 0) == 0) 893 panic("rn_init 2"); 894 } 895 896