1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1988, 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)radix.c 8.4 (Berkeley) 11/2/94 32 */ 33 34 /* 35 * Routines to build and maintain radix trees for routing lookups. 36 */ 37 38 #include "defs.h" 39 40 __RCSID("$FreeBSD$"); 41 42 #define log(x, msg) syslog(x, msg) 43 #define panic(s) {log(LOG_ERR,s); exit(1);} 44 #define min(a,b) (((a)<(b))?(a):(b)) 45 46 int max_keylen; 47 static struct radix_mask *rn_mkfreelist; 48 static struct radix_node_head *mask_rnhead; 49 static char *addmask_key; 50 static const uint8_t normal_chars[] = 51 { 0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff}; 52 static char *rn_zeros, *rn_ones; 53 54 #define rn_masktop (mask_rnhead->rnh_treetop) 55 #define Bcmp(a, b, l) (l == 0 ? 0 \ 56 : memcmp((caddr_t)(a), (caddr_t)(b), (size_t)l)) 57 58 static int rn_satisfies_leaf(char *, struct radix_node *, int); 59 static struct radix_node *rn_addmask(void *n_arg, int search, int skip); 60 static struct radix_node *rn_addroute(void *v_arg, void *n_arg, 61 struct radix_node_head *head, struct radix_node treenodes[2]); 62 static struct radix_node *rn_match(void *v_arg, struct radix_node_head *head); 63 64 /* 65 * The data structure for the keys is a radix tree with one way 66 * branching removed. The index rn_b at an internal node n represents a bit 67 * position to be tested. The tree is arranged so that all descendants 68 * of a node n have keys whose bits all agree up to position rn_b - 1. 69 * (We say the index of n is rn_b.) 70 * 71 * There is at least one descendant which has a one bit at position rn_b, 72 * and at least one with a zero there. 73 * 74 * A route is determined by a pair of key and mask. We require that the 75 * bit-wise logical and of the key and mask to be the key. 76 * We define the index of a route to associated with the mask to be 77 * the first bit number in the mask where 0 occurs (with bit number 0 78 * representing the highest order bit). 79 * 80 * We say a mask is normal if every bit is 0, past the index of the mask. 81 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_b, 82 * and m is a normal mask, then the route applies to every descendant of n. 83 * If the index(m) < rn_b, this implies the trailing last few bits of k 84 * before bit b are all 0, (and hence consequently true of every descendant 85 * of n), so the route applies to all descendants of the node as well. 86 * 87 * Similar logic shows that a non-normal mask m such that 88 * index(m) <= index(n) could potentially apply to many children of n. 89 * Thus, for each non-host route, we attach its mask to a list at an internal 90 * node as high in the tree as we can go. 91 * 92 * The present version of the code makes use of normal routes in short- 93 * circuiting an explicit mask and compare operation when testing whether 94 * a key satisfies a normal route, and also in remembering the unique leaf 95 * that governs a subtree. 96 */ 97 98 static struct radix_node * 99 rn_search(void *v_arg, 100 struct radix_node *head) 101 { 102 struct radix_node *x; 103 caddr_t v; 104 105 for (x = head, v = v_arg; x->rn_b >= 0;) { 106 if (x->rn_bmask & v[x->rn_off]) 107 x = x->rn_r; 108 else 109 x = x->rn_l; 110 } 111 return (x); 112 } 113 114 static struct radix_node * 115 rn_search_m(void *v_arg, 116 struct radix_node *head, 117 void *m_arg) 118 { 119 struct radix_node *x; 120 caddr_t v = v_arg, m = m_arg; 121 122 for (x = head; x->rn_b >= 0;) { 123 if ((x->rn_bmask & m[x->rn_off]) && 124 (x->rn_bmask & v[x->rn_off])) 125 x = x->rn_r; 126 else 127 x = x->rn_l; 128 } 129 return x; 130 } 131 132 static int 133 rn_refines(void* m_arg, void *n_arg) 134 { 135 caddr_t m = m_arg, n = n_arg; 136 caddr_t lim, lim2 = lim = n + *(u_char *)n; 137 int longer = (*(u_char *)n++) - (int)(*(u_char *)m++); 138 int masks_are_equal = 1; 139 140 if (longer > 0) 141 lim -= longer; 142 while (n < lim) { 143 if (*n & ~(*m)) 144 return 0; 145 if (*n++ != *m++) 146 masks_are_equal = 0; 147 } 148 while (n < lim2) 149 if (*n++) 150 return 0; 151 if (masks_are_equal && (longer < 0)) 152 for (lim2 = m - longer; m < lim2; ) 153 if (*m++) 154 return 1; 155 return (!masks_are_equal); 156 } 157 158 static struct radix_node * 159 rn_lookup(void *v_arg, void *m_arg, struct radix_node_head *head) 160 { 161 struct radix_node *x; 162 caddr_t netmask = 0; 163 164 if (m_arg) { 165 if ((x = rn_addmask(m_arg, 1, 166 head->rnh_treetop->rn_off)) == NULL) 167 return (0); 168 netmask = x->rn_key; 169 } 170 x = rn_match(v_arg, head); 171 if (x && netmask) { 172 while (x && x->rn_mask != netmask) 173 x = x->rn_dupedkey; 174 } 175 return x; 176 } 177 178 static int 179 rn_satisfies_leaf(char *trial, 180 struct radix_node *leaf, 181 int skip) 182 { 183 char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask; 184 char *cplim; 185 int length = min(*(u_char *)cp, *(u_char *)cp2); 186 187 if (cp3 == NULL) 188 cp3 = rn_ones; 189 else 190 length = min(length, *(u_char *)cp3); 191 cplim = cp + length; cp3 += skip; cp2 += skip; 192 for (cp += skip; cp < cplim; cp++, cp2++, cp3++) 193 if ((*cp ^ *cp2) & *cp3) 194 return 0; 195 return 1; 196 } 197 198 static struct radix_node * 199 rn_match(void *v_arg, 200 struct radix_node_head *head) 201 { 202 caddr_t v = v_arg; 203 struct radix_node *t = head->rnh_treetop, *x; 204 caddr_t cp = v, cp2; 205 caddr_t cplim; 206 struct radix_node *saved_t, *top = t; 207 int off = t->rn_off, vlen = *(u_char *)cp, matched_off; 208 int test, b, rn_b; 209 210 /* 211 * Open code rn_search(v, top) to avoid overhead of extra 212 * subroutine call. 213 */ 214 for (; t->rn_b >= 0; ) { 215 if (t->rn_bmask & cp[t->rn_off]) 216 t = t->rn_r; 217 else 218 t = t->rn_l; 219 } 220 /* 221 * See if we match exactly as a host destination 222 * or at least learn how many bits match, for normal mask finesse. 223 * 224 * It doesn't hurt us to limit how many bytes to check 225 * to the length of the mask, since if it matches we had a genuine 226 * match and the leaf we have is the most specific one anyway; 227 * if it didn't match with a shorter length it would fail 228 * with a long one. This wins big for class B&C netmasks which 229 * are probably the most common case... 230 */ 231 if (t->rn_mask) 232 vlen = *(u_char *)t->rn_mask; 233 cp += off; cp2 = t->rn_key + off; cplim = v + vlen; 234 for (; cp < cplim; cp++, cp2++) 235 if (*cp != *cp2) 236 goto on1; 237 /* 238 * This extra grot is in case we are explicitly asked 239 * to look up the default. Ugh! 240 * Or 255.255.255.255 241 * 242 * In this case, we have a complete match of the key. Unless 243 * the node is one of the roots, we are finished. 244 * If it is the zeros root, then take what we have, preferring 245 * any real data. 246 * If it is the ones root, then pretend the target key was followed 247 * by a byte of zeros. 248 */ 249 if (!(t->rn_flags & RNF_ROOT)) 250 return t; /* not a root */ 251 if (t->rn_dupedkey) { 252 t = t->rn_dupedkey; 253 return t; /* have some real data */ 254 } 255 if (*(cp-1) == 0) 256 return t; /* not the ones root */ 257 b = 0; /* fake a zero after 255.255.255.255 */ 258 goto on2; 259 on1: 260 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */ 261 for (b = 7; (test >>= 1) > 0;) 262 b--; 263 on2: 264 matched_off = cp - v; 265 b += matched_off << 3; 266 rn_b = -1 - b; 267 /* 268 * If there is a host route in a duped-key chain, it will be first. 269 */ 270 if ((saved_t = t)->rn_mask == 0) 271 t = t->rn_dupedkey; 272 for (; t; t = t->rn_dupedkey) { 273 /* 274 * Even if we don't match exactly as a host, 275 * we may match if the leaf we wound up at is 276 * a route to a net. 277 */ 278 if (t->rn_flags & RNF_NORMAL) { 279 if (rn_b <= t->rn_b) 280 return t; 281 } else if (rn_satisfies_leaf(v, t, matched_off)) { 282 return t; 283 } 284 } 285 t = saved_t; 286 /* start searching up the tree */ 287 do { 288 struct radix_mask *m; 289 t = t->rn_p; 290 if ((m = t->rn_mklist)) { 291 /* 292 * If non-contiguous masks ever become important 293 * we can restore the masking and open coding of 294 * the search and satisfaction test and put the 295 * calculation of "off" back before the "do". 296 */ 297 do { 298 if (m->rm_flags & RNF_NORMAL) { 299 if (rn_b <= m->rm_b) 300 return (m->rm_leaf); 301 } else { 302 off = min(t->rn_off, matched_off); 303 x = rn_search_m(v, t, m->rm_mask); 304 while (x && x->rn_mask != m->rm_mask) 305 x = x->rn_dupedkey; 306 if (x && rn_satisfies_leaf(v, x, off)) 307 return x; 308 } 309 } while ((m = m->rm_mklist)); 310 } 311 } while (t != top); 312 return 0; 313 } 314 315 #ifdef RN_DEBUG 316 int rn_nodenum; 317 struct radix_node *rn_clist; 318 int rn_saveinfo; 319 int rn_debug = 1; 320 #endif 321 322 static struct radix_node * 323 rn_newpair(void *v, int b, struct radix_node nodes[2]) 324 { 325 struct radix_node *tt = nodes, *t = tt + 1; 326 t->rn_b = b; t->rn_bmask = 0x80 >> (b & 7); 327 t->rn_l = tt; t->rn_off = b >> 3; 328 tt->rn_b = -1; tt->rn_key = (caddr_t)v; tt->rn_p = t; 329 tt->rn_flags = t->rn_flags = RNF_ACTIVE; 330 #ifdef RN_DEBUG 331 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 332 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 333 #endif 334 return t; 335 } 336 337 static struct radix_node * 338 rn_insert(void* v_arg, 339 struct radix_node_head *head, 340 int *dupentry, 341 struct radix_node nodes[2]) 342 { 343 caddr_t v = v_arg; 344 struct radix_node *top = head->rnh_treetop; 345 int head_off = top->rn_off, vlen = (int)*((u_char *)v); 346 struct radix_node *t = rn_search(v_arg, top); 347 caddr_t cp = v + head_off; 348 int b; 349 struct radix_node *tt; 350 351 /* 352 * Find first bit at which v and t->rn_key differ 353 */ 354 { 355 caddr_t cp2 = t->rn_key + head_off; 356 int cmp_res; 357 caddr_t cplim = v + vlen; 358 359 while (cp < cplim) 360 if (*cp2++ != *cp++) 361 goto on1; 362 /* handle adding 255.255.255.255 */ 363 if (!(t->rn_flags & RNF_ROOT) || *(cp2-1) == 0) { 364 *dupentry = 1; 365 return t; 366 } 367 on1: 368 *dupentry = 0; 369 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff; 370 for (b = (cp - v) << 3; cmp_res; b--) 371 cmp_res >>= 1; 372 } 373 { 374 struct radix_node *p, *x = top; 375 cp = v; 376 do { 377 p = x; 378 if (cp[x->rn_off] & x->rn_bmask) 379 x = x->rn_r; 380 else x = x->rn_l; 381 } while ((unsigned)b > (unsigned)x->rn_b); 382 #ifdef RN_DEBUG 383 if (rn_debug) 384 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p); 385 #endif 386 t = rn_newpair(v_arg, b, nodes); tt = t->rn_l; 387 if ((cp[p->rn_off] & p->rn_bmask) == 0) 388 p->rn_l = t; 389 else 390 p->rn_r = t; 391 x->rn_p = t; t->rn_p = p; /* frees x, p as temp vars below */ 392 if ((cp[t->rn_off] & t->rn_bmask) == 0) { 393 t->rn_r = x; 394 } else { 395 t->rn_r = tt; t->rn_l = x; 396 } 397 #ifdef RN_DEBUG 398 if (rn_debug) 399 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p); 400 #endif 401 } 402 return (tt); 403 } 404 405 static struct radix_node * 406 rn_addmask(void *n_arg, int search, int skip) 407 { 408 caddr_t netmask = (caddr_t)n_arg; 409 struct radix_node *x; 410 caddr_t cp, cplim; 411 int b = 0, mlen, j; 412 int maskduplicated, m0, isnormal; 413 struct radix_node *saved_x; 414 static int last_zeroed = 0; 415 416 if ((mlen = *(u_char *)netmask) > max_keylen) 417 mlen = max_keylen; 418 if (skip == 0) 419 skip = 1; 420 if (mlen <= skip) 421 return (mask_rnhead->rnh_nodes); 422 if (skip > 1) 423 Bcopy(rn_ones + 1, addmask_key + 1, skip - 1); 424 if ((m0 = mlen) > skip) 425 Bcopy(netmask + skip, addmask_key + skip, mlen - skip); 426 /* 427 * Trim trailing zeroes. 428 */ 429 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;) 430 cp--; 431 mlen = cp - addmask_key; 432 if (mlen <= skip) { 433 if (m0 >= last_zeroed) 434 last_zeroed = mlen; 435 return (mask_rnhead->rnh_nodes); 436 } 437 if (m0 < last_zeroed) 438 Bzero(addmask_key + m0, last_zeroed - m0); 439 *addmask_key = last_zeroed = mlen; 440 x = rn_search(addmask_key, rn_masktop); 441 if (Bcmp(addmask_key, x->rn_key, mlen) != 0) 442 x = NULL; 443 if (x || search) 444 return (x); 445 x = (struct radix_node *)rtmalloc(max_keylen + 2*sizeof(*x), 446 "rn_addmask"); 447 saved_x = x; 448 Bzero(x, max_keylen + 2 * sizeof (*x)); 449 netmask = cp = (caddr_t)(x + 2); 450 Bcopy(addmask_key, cp, mlen); 451 x = rn_insert(cp, mask_rnhead, &maskduplicated, x); 452 if (maskduplicated) { 453 log(LOG_ERR, "rn_addmask: mask impossibly already in tree"); 454 Free(saved_x); 455 return (x); 456 } 457 /* 458 * Calculate index of mask, and check for normalcy. 459 */ 460 cplim = netmask + mlen; isnormal = 1; 461 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;) 462 cp++; 463 if (cp != cplim) { 464 for (j = 0x80; (j & *cp) != 0; j >>= 1) 465 b++; 466 if (*cp != normal_chars[b] || cp != (cplim - 1)) 467 isnormal = 0; 468 } 469 b += (cp - netmask) << 3; 470 x->rn_b = -1 - b; 471 if (isnormal) 472 x->rn_flags |= RNF_NORMAL; 473 return (x); 474 } 475 476 static int /* XXX: arbitrary ordering for non-contiguous masks */ 477 rn_lexobetter(void *m_arg, void *n_arg) 478 { 479 u_char *mp = m_arg, *np = n_arg, *lim; 480 481 if (*mp > *np) 482 return 1; /* not really, but need to check longer one first */ 483 if (*mp == *np) 484 for (lim = mp + *mp; mp < lim;) 485 if (*mp++ > *np++) 486 return 1; 487 return 0; 488 } 489 490 static struct radix_mask * 491 rn_new_radix_mask(struct radix_node *tt, 492 struct radix_mask *next) 493 { 494 struct radix_mask *m; 495 496 MKGet(m); 497 if (m == NULL) { 498 log(LOG_ERR, "Mask for route not entered\n"); 499 return (0); 500 } 501 Bzero(m, sizeof *m); 502 m->rm_b = tt->rn_b; 503 m->rm_flags = tt->rn_flags; 504 if (tt->rn_flags & RNF_NORMAL) 505 m->rm_leaf = tt; 506 else 507 m->rm_mask = tt->rn_mask; 508 m->rm_mklist = next; 509 tt->rn_mklist = m; 510 return m; 511 } 512 513 static struct radix_node * 514 rn_addroute(void *v_arg, 515 void *n_arg, 516 struct radix_node_head *head, 517 struct radix_node treenodes[2]) 518 { 519 caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg; 520 struct radix_node *t, *x = NULL, *tt; 521 struct radix_node *saved_tt, *top = head->rnh_treetop; 522 short b = 0, b_leaf = 0; 523 int keyduplicated; 524 caddr_t mmask; 525 struct radix_mask *m, **mp; 526 527 /* 528 * In dealing with non-contiguous masks, there may be 529 * many different routes which have the same mask. 530 * We will find it useful to have a unique pointer to 531 * the mask to speed avoiding duplicate references at 532 * nodes and possibly save time in calculating indices. 533 */ 534 if (netmask) { 535 if ((x = rn_addmask(netmask, 0, top->rn_off)) == NULL) 536 return (0); 537 b_leaf = x->rn_b; 538 b = -1 - x->rn_b; 539 netmask = x->rn_key; 540 } 541 /* 542 * Deal with duplicated keys: attach node to previous instance 543 */ 544 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes); 545 if (keyduplicated) { 546 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) { 547 if (tt->rn_mask == netmask) 548 return (0); 549 if (netmask == 0 || 550 (tt->rn_mask && 551 ((b_leaf < tt->rn_b) || /* index(netmask) > node */ 552 rn_refines(netmask, tt->rn_mask) || 553 rn_lexobetter(netmask, tt->rn_mask)))) 554 break; 555 } 556 /* 557 * If the mask is not duplicated, we wouldn't 558 * find it among possible duplicate key entries 559 * anyway, so the above test doesn't hurt. 560 * 561 * We sort the masks for a duplicated key the same way as 562 * in a masklist -- most specific to least specific. 563 * This may require the unfortunate nuisance of relocating 564 * the head of the list. 565 */ 566 if (tt == saved_tt) { 567 struct radix_node *xx = x; 568 /* link in at head of list */ 569 (tt = treenodes)->rn_dupedkey = t; 570 tt->rn_flags = t->rn_flags; 571 tt->rn_p = x = t->rn_p; 572 if (x->rn_l == t) x->rn_l = tt; else x->rn_r = tt; 573 saved_tt = tt; x = xx; 574 } else { 575 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey; 576 t->rn_dupedkey = tt; 577 } 578 #ifdef RN_DEBUG 579 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 580 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 581 #endif 582 tt->rn_key = (caddr_t) v; 583 tt->rn_b = -1; 584 tt->rn_flags = RNF_ACTIVE; 585 } 586 /* 587 * Put mask in tree. 588 */ 589 if (netmask) { 590 tt->rn_mask = netmask; 591 tt->rn_b = x->rn_b; 592 tt->rn_flags |= x->rn_flags & RNF_NORMAL; 593 } 594 t = saved_tt->rn_p; 595 if (keyduplicated) 596 goto on2; 597 b_leaf = -1 - t->rn_b; 598 if (t->rn_r == saved_tt) x = t->rn_l; else x = t->rn_r; 599 /* Promote general routes from below */ 600 if (x->rn_b < 0) { 601 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey) 602 if (x->rn_mask && (x->rn_b >= b_leaf) && x->rn_mklist == 0) { 603 if ((*mp = m = rn_new_radix_mask(x, 0))) 604 mp = &m->rm_mklist; 605 } 606 } else if (x->rn_mklist) { 607 /* 608 * Skip over masks whose index is > that of new node 609 */ 610 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 611 if (m->rm_b >= b_leaf) 612 break; 613 t->rn_mklist = m; *mp = NULL; 614 } 615 on2: 616 /* Add new route to highest possible ancestor's list */ 617 if ((netmask == 0) || (b > t->rn_b )) 618 return tt; /* can't lift at all */ 619 b_leaf = tt->rn_b; 620 do { 621 x = t; 622 t = t->rn_p; 623 } while (b <= t->rn_b && x != top); 624 /* 625 * Search through routes associated with node to 626 * insert new route according to index. 627 * Need same criteria as when sorting dupedkeys to avoid 628 * double loop on deletion. 629 */ 630 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) { 631 if (m->rm_b < b_leaf) 632 continue; 633 if (m->rm_b > b_leaf) 634 break; 635 if (m->rm_flags & RNF_NORMAL) { 636 mmask = m->rm_leaf->rn_mask; 637 if (tt->rn_flags & RNF_NORMAL) { 638 log(LOG_ERR, 639 "Non-unique normal route, mask not entered"); 640 return tt; 641 } 642 } else 643 mmask = m->rm_mask; 644 if (mmask == netmask) { 645 m->rm_refs++; 646 tt->rn_mklist = m; 647 return tt; 648 } 649 if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask)) 650 break; 651 } 652 *mp = rn_new_radix_mask(tt, *mp); 653 return tt; 654 } 655 656 static struct radix_node * 657 rn_delete(void *v_arg, 658 void *netmask_arg, 659 struct radix_node_head *head) 660 { 661 struct radix_node *t, *p, *x, *tt; 662 struct radix_mask *m, *saved_m, **mp; 663 struct radix_node *dupedkey, *saved_tt, *top; 664 caddr_t v, netmask; 665 int b, head_off, vlen; 666 667 v = v_arg; 668 netmask = netmask_arg; 669 x = head->rnh_treetop; 670 tt = rn_search(v, x); 671 head_off = x->rn_off; 672 vlen = *(u_char *)v; 673 saved_tt = tt; 674 top = x; 675 if (tt == NULL || 676 Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off)) 677 return (0); 678 /* 679 * Delete our route from mask lists. 680 */ 681 if (netmask) { 682 if ((x = rn_addmask(netmask, 1, head_off)) == NULL) 683 return (0); 684 netmask = x->rn_key; 685 while (tt->rn_mask != netmask) 686 if ((tt = tt->rn_dupedkey) == NULL) 687 return (0); 688 } 689 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == NULL) 690 goto on1; 691 if (tt->rn_flags & RNF_NORMAL) { 692 if (m->rm_leaf != tt || m->rm_refs > 0) { 693 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 694 return 0; /* dangling ref could cause disaster */ 695 } 696 } else { 697 if (m->rm_mask != tt->rn_mask) { 698 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 699 goto on1; 700 } 701 if (--m->rm_refs >= 0) 702 goto on1; 703 } 704 b = -1 - tt->rn_b; 705 t = saved_tt->rn_p; 706 if (b > t->rn_b) 707 goto on1; /* Wasn't lifted at all */ 708 do { 709 x = t; 710 t = t->rn_p; 711 } while (b <= t->rn_b && x != top); 712 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 713 if (m == saved_m) { 714 *mp = m->rm_mklist; 715 MKFree(m); 716 break; 717 } 718 if (m == NULL) { 719 log(LOG_ERR, "rn_delete: couldn't find our annotation\n"); 720 if (tt->rn_flags & RNF_NORMAL) 721 return (0); /* Dangling ref to us */ 722 } 723 on1: 724 /* 725 * Eliminate us from tree 726 */ 727 if (tt->rn_flags & RNF_ROOT) 728 return (0); 729 #ifdef RN_DEBUG 730 /* Get us out of the creation list */ 731 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {} 732 if (t) t->rn_ybro = tt->rn_ybro; 733 #endif 734 t = tt->rn_p; 735 if ((dupedkey = saved_tt->rn_dupedkey)) { 736 if (tt == saved_tt) { 737 x = dupedkey; x->rn_p = t; 738 if (t->rn_l == tt) t->rn_l = x; else t->rn_r = x; 739 } else { 740 for (x = p = saved_tt; p && p->rn_dupedkey != tt;) 741 p = p->rn_dupedkey; 742 if (p) p->rn_dupedkey = tt->rn_dupedkey; 743 else log(LOG_ERR, "rn_delete: couldn't find us\n"); 744 } 745 t = tt + 1; 746 if (t->rn_flags & RNF_ACTIVE) { 747 #ifndef RN_DEBUG 748 *++x = *t; p = t->rn_p; 749 #else 750 b = t->rn_info; *++x = *t; t->rn_info = b; p = t->rn_p; 751 #endif 752 if (p->rn_l == t) p->rn_l = x; else p->rn_r = x; 753 x->rn_l->rn_p = x; x->rn_r->rn_p = x; 754 } 755 goto out; 756 } 757 if (t->rn_l == tt) x = t->rn_r; else x = t->rn_l; 758 p = t->rn_p; 759 if (p->rn_r == t) p->rn_r = x; else p->rn_l = x; 760 x->rn_p = p; 761 /* 762 * Demote routes attached to us. 763 */ 764 if (t->rn_mklist) { 765 if (x->rn_b >= 0) { 766 for (mp = &x->rn_mklist; (m = *mp);) 767 mp = &m->rm_mklist; 768 *mp = t->rn_mklist; 769 } else { 770 /* If there are any key,mask pairs in a sibling 771 duped-key chain, some subset will appear sorted 772 in the same order attached to our mklist */ 773 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey) 774 if (m == x->rn_mklist) { 775 struct radix_mask *mm = m->rm_mklist; 776 x->rn_mklist = 0; 777 if (--(m->rm_refs) < 0) 778 MKFree(m); 779 m = mm; 780 } 781 if (m) 782 syslog(LOG_ERR, "%s 0x%lx at 0x%lx\n", 783 "rn_delete: Orphaned Mask", 784 (unsigned long)m, 785 (unsigned long)x); 786 } 787 } 788 /* 789 * We may be holding an active internal node in the tree. 790 */ 791 x = tt + 1; 792 if (t != x) { 793 #ifndef RN_DEBUG 794 *t = *x; 795 #else 796 b = t->rn_info; *t = *x; t->rn_info = b; 797 #endif 798 t->rn_l->rn_p = t; t->rn_r->rn_p = t; 799 p = x->rn_p; 800 if (p->rn_l == x) p->rn_l = t; else p->rn_r = t; 801 } 802 out: 803 tt->rn_flags &= ~RNF_ACTIVE; 804 tt[1].rn_flags &= ~RNF_ACTIVE; 805 return (tt); 806 } 807 808 int 809 rn_walktree(struct radix_node_head *h, 810 int (*f)(struct radix_node *, struct walkarg *), 811 struct walkarg *w) 812 { 813 int error; 814 struct radix_node *base, *next; 815 struct radix_node *rn = h->rnh_treetop; 816 /* 817 * This gets complicated because we may delete the node 818 * while applying the function f to it, so we need to calculate 819 * the successor node in advance. 820 */ 821 /* First time through node, go left */ 822 while (rn->rn_b >= 0) 823 rn = rn->rn_l; 824 for (;;) { 825 base = rn; 826 /* If at right child go back up, otherwise, go right */ 827 while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0) 828 rn = rn->rn_p; 829 /* Find the next *leaf* since next node might vanish, too */ 830 for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;) 831 rn = rn->rn_l; 832 next = rn; 833 /* Process leaves */ 834 while ((rn = base)) { 835 base = rn->rn_dupedkey; 836 if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w))) 837 return (error); 838 } 839 rn = next; 840 if (rn->rn_flags & RNF_ROOT) 841 return (0); 842 } 843 /* NOTREACHED */ 844 } 845 846 int 847 rn_inithead(struct radix_node_head **head, int off) 848 { 849 struct radix_node_head *rnh; 850 struct radix_node *t, *tt, *ttt; 851 if (*head) 852 return (1); 853 rnh = (struct radix_node_head *)rtmalloc(sizeof(*rnh), "rn_inithead"); 854 Bzero(rnh, sizeof (*rnh)); 855 *head = rnh; 856 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes); 857 ttt = rnh->rnh_nodes + 2; 858 t->rn_r = ttt; 859 t->rn_p = t; 860 tt = t->rn_l; 861 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE; 862 tt->rn_b = -1 - off; 863 *ttt = *tt; 864 ttt->rn_key = rn_ones; 865 rnh->rnh_addaddr = rn_addroute; 866 rnh->rnh_deladdr = rn_delete; 867 rnh->rnh_matchaddr = rn_match; 868 rnh->rnh_lookup = rn_lookup; 869 rnh->rnh_walktree = rn_walktree; 870 rnh->rnh_treetop = t; 871 return (1); 872 } 873 874 void 875 rn_init(void) 876 { 877 char *cp, *cplim; 878 if (max_keylen == 0) { 879 printf("rn_init: radix functions require max_keylen be set\n"); 880 return; 881 } 882 rn_zeros = (char *)rtmalloc(3 * max_keylen, "rn_init"); 883 Bzero(rn_zeros, 3 * max_keylen); 884 rn_ones = cp = rn_zeros + max_keylen; 885 addmask_key = cplim = rn_ones + max_keylen; 886 while (cp < cplim) 887 *cp++ = -1; 888 if (rn_inithead(&mask_rnhead, 0) == 0) 889 panic("rn_init 2"); 890 } 891 892