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