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 * $FreeBSD$ 34 */ 35 36 /* 37 * Routines to build and maintain radix trees for routing lookups. 38 */ 39 40 #include "defs.h" 41 42 #ifdef __NetBSD__ 43 __RCSID("$NetBSD$"); 44 #elif defined(__FreeBSD__) 45 __RCSID("$FreeBSD$"); 46 #else 47 __RCSID("$Revision: 2.23 $"); 48 #ident "$Revision: 2.23 $" 49 #endif 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 static struct radix_mask *rn_mkfreelist; 57 static struct radix_node_head *mask_rnhead; 58 static char *addmask_key; 59 static const uint8_t normal_chars[] = 60 { 0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff}; 61 static char *rn_zeros, *rn_ones; 62 63 #define rn_masktop (mask_rnhead->rnh_treetop) 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 static struct radix_node *rn_addmask(void *n_arg, int search, int skip); 69 static struct radix_node *rn_addroute(void *v_arg, void *n_arg, 70 struct radix_node_head *head, struct radix_node treenodes[2]); 71 static struct radix_node *rn_match(void *v_arg, struct radix_node_head *head); 72 73 /* 74 * The data structure for the keys is a radix tree with one way 75 * branching removed. The index rn_b at an internal node n represents a bit 76 * position to be tested. The tree is arranged so that all descendants 77 * of a node n have keys whose bits all agree up to position rn_b - 1. 78 * (We say the index of n is rn_b.) 79 * 80 * There is at least one descendant which has a one bit at position rn_b, 81 * and at least one with a zero there. 82 * 83 * A route is determined by a pair of key and mask. We require that the 84 * bit-wise logical and of the key and mask to be the key. 85 * We define the index of a route to associated with the mask to be 86 * the first bit number in the mask where 0 occurs (with bit number 0 87 * representing the highest order bit). 88 * 89 * We say a mask is normal if every bit is 0, past the index of the mask. 90 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_b, 91 * and m is a normal mask, then the route applies to every descendant of n. 92 * If the index(m) < rn_b, this implies the trailing last few bits of k 93 * before bit b are all 0, (and hence consequently true of every descendant 94 * of n), so the route applies to all descendants of the node as well. 95 * 96 * Similar logic shows that a non-normal mask m such that 97 * index(m) <= index(n) could potentially apply to many children of n. 98 * Thus, for each non-host route, we attach its mask to a list at an internal 99 * node as high in the tree as we can go. 100 * 101 * The present version of the code makes use of normal routes in short- 102 * circuiting an explicit mask and compare operation when testing whether 103 * a key satisfies a normal route, and also in remembering the unique leaf 104 * that governs a subtree. 105 */ 106 107 static struct radix_node * 108 rn_search(void *v_arg, 109 struct radix_node *head) 110 { 111 struct radix_node *x; 112 caddr_t v; 113 114 for (x = head, v = v_arg; x->rn_b >= 0;) { 115 if (x->rn_bmask & v[x->rn_off]) 116 x = x->rn_r; 117 else 118 x = x->rn_l; 119 } 120 return (x); 121 } 122 123 static struct radix_node * 124 rn_search_m(void *v_arg, 125 struct radix_node *head, 126 void *m_arg) 127 { 128 struct radix_node *x; 129 caddr_t v = v_arg, m = m_arg; 130 131 for (x = head; x->rn_b >= 0;) { 132 if ((x->rn_bmask & m[x->rn_off]) && 133 (x->rn_bmask & v[x->rn_off])) 134 x = x->rn_r; 135 else 136 x = x->rn_l; 137 } 138 return x; 139 } 140 141 static int 142 rn_refines(void* m_arg, void *n_arg) 143 { 144 caddr_t m = m_arg, n = n_arg; 145 caddr_t lim, lim2 = lim = n + *(u_char *)n; 146 int longer = (*(u_char *)n++) - (int)(*(u_char *)m++); 147 int masks_are_equal = 1; 148 149 if (longer > 0) 150 lim -= longer; 151 while (n < lim) { 152 if (*n & ~(*m)) 153 return 0; 154 if (*n++ != *m++) 155 masks_are_equal = 0; 156 } 157 while (n < lim2) 158 if (*n++) 159 return 0; 160 if (masks_are_equal && (longer < 0)) 161 for (lim2 = m - longer; m < lim2; ) 162 if (*m++) 163 return 1; 164 return (!masks_are_equal); 165 } 166 167 static struct radix_node * 168 rn_lookup(void *v_arg, void *m_arg, struct radix_node_head *head) 169 { 170 struct radix_node *x; 171 caddr_t netmask = 0; 172 173 if (m_arg) { 174 if ((x = rn_addmask(m_arg, 1, 175 head->rnh_treetop->rn_off)) == NULL) 176 return (0); 177 netmask = x->rn_key; 178 } 179 x = rn_match(v_arg, head); 180 if (x && netmask) { 181 while (x && x->rn_mask != netmask) 182 x = x->rn_dupedkey; 183 } 184 return x; 185 } 186 187 static int 188 rn_satisfies_leaf(char *trial, 189 struct radix_node *leaf, 190 int skip) 191 { 192 char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask; 193 char *cplim; 194 int length = min(*(u_char *)cp, *(u_char *)cp2); 195 196 if (cp3 == NULL) 197 cp3 = rn_ones; 198 else 199 length = min(length, *(u_char *)cp3); 200 cplim = cp + length; cp3 += skip; cp2 += skip; 201 for (cp += skip; cp < cplim; cp++, cp2++, cp3++) 202 if ((*cp ^ *cp2) & *cp3) 203 return 0; 204 return 1; 205 } 206 207 static struct radix_node * 208 rn_match(void *v_arg, 209 struct radix_node_head *head) 210 { 211 caddr_t v = v_arg; 212 struct radix_node *t = head->rnh_treetop, *x; 213 caddr_t cp = v, cp2; 214 caddr_t cplim; 215 struct radix_node *saved_t, *top = t; 216 int off = t->rn_off, vlen = *(u_char *)cp, matched_off; 217 int test, b, rn_b; 218 219 /* 220 * Open code rn_search(v, top) to avoid overhead of extra 221 * subroutine call. 222 */ 223 for (; t->rn_b >= 0; ) { 224 if (t->rn_bmask & cp[t->rn_off]) 225 t = t->rn_r; 226 else 227 t = t->rn_l; 228 } 229 /* 230 * See if we match exactly as a host destination 231 * or at least learn how many bits match, for normal mask finesse. 232 * 233 * It doesn't hurt us to limit how many bytes to check 234 * to the length of the mask, since if it matches we had a genuine 235 * match and the leaf we have is the most specific one anyway; 236 * if it didn't match with a shorter length it would fail 237 * with a long one. This wins big for class B&C netmasks which 238 * are probably the most common case... 239 */ 240 if (t->rn_mask) 241 vlen = *(u_char *)t->rn_mask; 242 cp += off; cp2 = t->rn_key + off; cplim = v + vlen; 243 for (; cp < cplim; cp++, cp2++) 244 if (*cp != *cp2) 245 goto on1; 246 /* 247 * This extra grot is in case we are explicitly asked 248 * to look up the default. Ugh! 249 * Or 255.255.255.255 250 * 251 * In this case, we have a complete match of the key. Unless 252 * the node is one of the roots, we are finished. 253 * If it is the zeros root, then take what we have, preferring 254 * any real data. 255 * If it is the ones root, then pretend the target key was followed 256 * by a byte of zeros. 257 */ 258 if (!(t->rn_flags & RNF_ROOT)) 259 return t; /* not a root */ 260 if (t->rn_dupedkey) { 261 t = t->rn_dupedkey; 262 return t; /* have some real data */ 263 } 264 if (*(cp-1) == 0) 265 return t; /* not the ones root */ 266 b = 0; /* fake a zero after 255.255.255.255 */ 267 goto on2; 268 on1: 269 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */ 270 for (b = 7; (test >>= 1) > 0;) 271 b--; 272 on2: 273 matched_off = cp - v; 274 b += matched_off << 3; 275 rn_b = -1 - b; 276 /* 277 * If there is a host route in a duped-key chain, it will be first. 278 */ 279 if ((saved_t = t)->rn_mask == 0) 280 t = t->rn_dupedkey; 281 for (; t; t = t->rn_dupedkey) { 282 /* 283 * Even if we don't match exactly as a host, 284 * we may match if the leaf we wound up at is 285 * a route to a net. 286 */ 287 if (t->rn_flags & RNF_NORMAL) { 288 if (rn_b <= t->rn_b) 289 return t; 290 } else if (rn_satisfies_leaf(v, t, matched_off)) { 291 return t; 292 } 293 } 294 t = saved_t; 295 /* start searching up the tree */ 296 do { 297 struct radix_mask *m; 298 t = t->rn_p; 299 if ((m = t->rn_mklist)) { 300 /* 301 * If non-contiguous masks ever become important 302 * we can restore the masking and open coding of 303 * the search and satisfaction test and put the 304 * calculation of "off" back before the "do". 305 */ 306 do { 307 if (m->rm_flags & RNF_NORMAL) { 308 if (rn_b <= m->rm_b) 309 return (m->rm_leaf); 310 } else { 311 off = min(t->rn_off, matched_off); 312 x = rn_search_m(v, t, m->rm_mask); 313 while (x && x->rn_mask != m->rm_mask) 314 x = x->rn_dupedkey; 315 if (x && rn_satisfies_leaf(v, x, off)) 316 return x; 317 } 318 } while ((m = m->rm_mklist)); 319 } 320 } while (t != top); 321 return 0; 322 } 323 324 #ifdef RN_DEBUG 325 int rn_nodenum; 326 struct radix_node *rn_clist; 327 int rn_saveinfo; 328 int rn_debug = 1; 329 #endif 330 331 static struct radix_node * 332 rn_newpair(void *v, int b, struct radix_node nodes[2]) 333 { 334 struct radix_node *tt = nodes, *t = tt + 1; 335 t->rn_b = b; t->rn_bmask = 0x80 >> (b & 7); 336 t->rn_l = tt; t->rn_off = b >> 3; 337 tt->rn_b = -1; tt->rn_key = (caddr_t)v; tt->rn_p = t; 338 tt->rn_flags = t->rn_flags = RNF_ACTIVE; 339 #ifdef RN_DEBUG 340 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 341 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 342 #endif 343 return t; 344 } 345 346 static struct radix_node * 347 rn_insert(void* v_arg, 348 struct radix_node_head *head, 349 int *dupentry, 350 struct radix_node nodes[2]) 351 { 352 caddr_t v = v_arg; 353 struct radix_node *top = head->rnh_treetop; 354 int head_off = top->rn_off, vlen = (int)*((u_char *)v); 355 struct radix_node *t = rn_search(v_arg, top); 356 caddr_t cp = v + head_off; 357 int b; 358 struct radix_node *tt; 359 360 /* 361 * Find first bit at which v and t->rn_key differ 362 */ 363 { 364 caddr_t cp2 = t->rn_key + head_off; 365 int cmp_res; 366 caddr_t cplim = v + vlen; 367 368 while (cp < cplim) 369 if (*cp2++ != *cp++) 370 goto on1; 371 /* handle adding 255.255.255.255 */ 372 if (!(t->rn_flags & RNF_ROOT) || *(cp2-1) == 0) { 373 *dupentry = 1; 374 return t; 375 } 376 on1: 377 *dupentry = 0; 378 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff; 379 for (b = (cp - v) << 3; cmp_res; b--) 380 cmp_res >>= 1; 381 } 382 { 383 struct radix_node *p, *x = top; 384 cp = v; 385 do { 386 p = x; 387 if (cp[x->rn_off] & x->rn_bmask) 388 x = x->rn_r; 389 else x = x->rn_l; 390 } while ((unsigned)b > (unsigned)x->rn_b); 391 #ifdef RN_DEBUG 392 if (rn_debug) 393 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p); 394 #endif 395 t = rn_newpair(v_arg, b, nodes); tt = t->rn_l; 396 if ((cp[p->rn_off] & p->rn_bmask) == 0) 397 p->rn_l = t; 398 else 399 p->rn_r = t; 400 x->rn_p = t; t->rn_p = p; /* frees x, p as temp vars below */ 401 if ((cp[t->rn_off] & t->rn_bmask) == 0) { 402 t->rn_r = x; 403 } else { 404 t->rn_r = tt; t->rn_l = x; 405 } 406 #ifdef RN_DEBUG 407 if (rn_debug) 408 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p); 409 #endif 410 } 411 return (tt); 412 } 413 414 static struct radix_node * 415 rn_addmask(void *n_arg, int search, int skip) 416 { 417 caddr_t netmask = (caddr_t)n_arg; 418 struct radix_node *x; 419 caddr_t cp, cplim; 420 int b = 0, mlen, j; 421 int maskduplicated, m0, isnormal; 422 struct radix_node *saved_x; 423 static int last_zeroed = 0; 424 425 if ((mlen = *(u_char *)netmask) > max_keylen) 426 mlen = max_keylen; 427 if (skip == 0) 428 skip = 1; 429 if (mlen <= skip) 430 return (mask_rnhead->rnh_nodes); 431 if (skip > 1) 432 Bcopy(rn_ones + 1, addmask_key + 1, skip - 1); 433 if ((m0 = mlen) > skip) 434 Bcopy(netmask + skip, addmask_key + skip, mlen - skip); 435 /* 436 * Trim trailing zeroes. 437 */ 438 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;) 439 cp--; 440 mlen = cp - addmask_key; 441 if (mlen <= skip) { 442 if (m0 >= last_zeroed) 443 last_zeroed = mlen; 444 return (mask_rnhead->rnh_nodes); 445 } 446 if (m0 < last_zeroed) 447 Bzero(addmask_key + m0, last_zeroed - m0); 448 *addmask_key = last_zeroed = mlen; 449 x = rn_search(addmask_key, rn_masktop); 450 if (Bcmp(addmask_key, x->rn_key, mlen) != 0) 451 x = NULL; 452 if (x || search) 453 return (x); 454 x = (struct radix_node *)rtmalloc(max_keylen + 2*sizeof(*x), 455 "rn_addmask"); 456 saved_x = x; 457 Bzero(x, max_keylen + 2 * sizeof (*x)); 458 netmask = cp = (caddr_t)(x + 2); 459 Bcopy(addmask_key, cp, mlen); 460 x = rn_insert(cp, mask_rnhead, &maskduplicated, x); 461 if (maskduplicated) { 462 log(LOG_ERR, "rn_addmask: mask impossibly already in tree"); 463 Free(saved_x); 464 return (x); 465 } 466 /* 467 * Calculate index of mask, and check for normalcy. 468 */ 469 cplim = netmask + mlen; isnormal = 1; 470 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;) 471 cp++; 472 if (cp != cplim) { 473 for (j = 0x80; (j & *cp) != 0; j >>= 1) 474 b++; 475 if (*cp != normal_chars[b] || cp != (cplim - 1)) 476 isnormal = 0; 477 } 478 b += (cp - netmask) << 3; 479 x->rn_b = -1 - b; 480 if (isnormal) 481 x->rn_flags |= RNF_NORMAL; 482 return (x); 483 } 484 485 static int /* XXX: arbitrary ordering for non-contiguous masks */ 486 rn_lexobetter(void *m_arg, void *n_arg) 487 { 488 u_char *mp = m_arg, *np = n_arg, *lim; 489 490 if (*mp > *np) 491 return 1; /* not really, but need to check longer one first */ 492 if (*mp == *np) 493 for (lim = mp + *mp; mp < lim;) 494 if (*mp++ > *np++) 495 return 1; 496 return 0; 497 } 498 499 static struct radix_mask * 500 rn_new_radix_mask(struct radix_node *tt, 501 struct radix_mask *next) 502 { 503 struct radix_mask *m; 504 505 MKGet(m); 506 if (m == NULL) { 507 log(LOG_ERR, "Mask for route not entered\n"); 508 return (0); 509 } 510 Bzero(m, sizeof *m); 511 m->rm_b = tt->rn_b; 512 m->rm_flags = tt->rn_flags; 513 if (tt->rn_flags & RNF_NORMAL) 514 m->rm_leaf = tt; 515 else 516 m->rm_mask = tt->rn_mask; 517 m->rm_mklist = next; 518 tt->rn_mklist = m; 519 return m; 520 } 521 522 static struct radix_node * 523 rn_addroute(void *v_arg, 524 void *n_arg, 525 struct radix_node_head *head, 526 struct radix_node treenodes[2]) 527 { 528 caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg; 529 struct radix_node *t, *x = NULL, *tt; 530 struct radix_node *saved_tt, *top = head->rnh_treetop; 531 short b = 0, b_leaf = 0; 532 int keyduplicated; 533 caddr_t mmask; 534 struct radix_mask *m, **mp; 535 536 /* 537 * In dealing with non-contiguous masks, there may be 538 * many different routes which have the same mask. 539 * We will find it useful to have a unique pointer to 540 * the mask to speed avoiding duplicate references at 541 * nodes and possibly save time in calculating indices. 542 */ 543 if (netmask) { 544 if ((x = rn_addmask(netmask, 0, top->rn_off)) == NULL) 545 return (0); 546 b_leaf = x->rn_b; 547 b = -1 - x->rn_b; 548 netmask = x->rn_key; 549 } 550 /* 551 * Deal with duplicated keys: attach node to previous instance 552 */ 553 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes); 554 if (keyduplicated) { 555 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) { 556 if (tt->rn_mask == netmask) 557 return (0); 558 if (netmask == 0 || 559 (tt->rn_mask && 560 ((b_leaf < tt->rn_b) || /* index(netmask) > node */ 561 rn_refines(netmask, tt->rn_mask) || 562 rn_lexobetter(netmask, tt->rn_mask)))) 563 break; 564 } 565 /* 566 * If the mask is not duplicated, we wouldn't 567 * find it among possible duplicate key entries 568 * anyway, so the above test doesn't hurt. 569 * 570 * We sort the masks for a duplicated key the same way as 571 * in a masklist -- most specific to least specific. 572 * This may require the unfortunate nuisance of relocating 573 * the head of the list. 574 */ 575 if (tt == saved_tt) { 576 struct radix_node *xx = x; 577 /* link in at head of list */ 578 (tt = treenodes)->rn_dupedkey = t; 579 tt->rn_flags = t->rn_flags; 580 tt->rn_p = x = t->rn_p; 581 if (x->rn_l == t) x->rn_l = tt; else x->rn_r = tt; 582 saved_tt = tt; x = xx; 583 } else { 584 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey; 585 t->rn_dupedkey = tt; 586 } 587 #ifdef RN_DEBUG 588 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 589 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 590 #endif 591 tt->rn_key = (caddr_t) v; 592 tt->rn_b = -1; 593 tt->rn_flags = RNF_ACTIVE; 594 } 595 /* 596 * Put mask in tree. 597 */ 598 if (netmask) { 599 tt->rn_mask = netmask; 600 tt->rn_b = x->rn_b; 601 tt->rn_flags |= x->rn_flags & RNF_NORMAL; 602 } 603 t = saved_tt->rn_p; 604 if (keyduplicated) 605 goto on2; 606 b_leaf = -1 - t->rn_b; 607 if (t->rn_r == saved_tt) x = t->rn_l; else x = t->rn_r; 608 /* Promote general routes from below */ 609 if (x->rn_b < 0) { 610 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey) 611 if (x->rn_mask && (x->rn_b >= b_leaf) && x->rn_mklist == 0) { 612 if ((*mp = m = rn_new_radix_mask(x, 0))) 613 mp = &m->rm_mklist; 614 } 615 } else if (x->rn_mklist) { 616 /* 617 * Skip over masks whose index is > that of new node 618 */ 619 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 620 if (m->rm_b >= b_leaf) 621 break; 622 t->rn_mklist = m; *mp = NULL; 623 } 624 on2: 625 /* Add new route to highest possible ancestor's list */ 626 if ((netmask == 0) || (b > t->rn_b )) 627 return tt; /* can't lift at all */ 628 b_leaf = tt->rn_b; 629 do { 630 x = t; 631 t = t->rn_p; 632 } while (b <= t->rn_b && x != top); 633 /* 634 * Search through routes associated with node to 635 * insert new route according to index. 636 * Need same criteria as when sorting dupedkeys to avoid 637 * double loop on deletion. 638 */ 639 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) { 640 if (m->rm_b < b_leaf) 641 continue; 642 if (m->rm_b > b_leaf) 643 break; 644 if (m->rm_flags & RNF_NORMAL) { 645 mmask = m->rm_leaf->rn_mask; 646 if (tt->rn_flags & RNF_NORMAL) { 647 log(LOG_ERR, 648 "Non-unique normal route, mask not entered"); 649 return tt; 650 } 651 } else 652 mmask = m->rm_mask; 653 if (mmask == netmask) { 654 m->rm_refs++; 655 tt->rn_mklist = m; 656 return tt; 657 } 658 if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask)) 659 break; 660 } 661 *mp = rn_new_radix_mask(tt, *mp); 662 return tt; 663 } 664 665 static struct radix_node * 666 rn_delete(void *v_arg, 667 void *netmask_arg, 668 struct radix_node_head *head) 669 { 670 struct radix_node *t, *p, *x, *tt; 671 struct radix_mask *m, *saved_m, **mp; 672 struct radix_node *dupedkey, *saved_tt, *top; 673 caddr_t v, netmask; 674 int b, head_off, vlen; 675 676 v = v_arg; 677 netmask = netmask_arg; 678 x = head->rnh_treetop; 679 tt = rn_search(v, x); 680 head_off = x->rn_off; 681 vlen = *(u_char *)v; 682 saved_tt = tt; 683 top = x; 684 if (tt == NULL || 685 Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off)) 686 return (0); 687 /* 688 * Delete our route from mask lists. 689 */ 690 if (netmask) { 691 if ((x = rn_addmask(netmask, 1, head_off)) == NULL) 692 return (0); 693 netmask = x->rn_key; 694 while (tt->rn_mask != netmask) 695 if ((tt = tt->rn_dupedkey) == NULL) 696 return (0); 697 } 698 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == NULL) 699 goto on1; 700 if (tt->rn_flags & RNF_NORMAL) { 701 if (m->rm_leaf != tt || m->rm_refs > 0) { 702 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 703 return 0; /* dangling ref could cause disaster */ 704 } 705 } else { 706 if (m->rm_mask != tt->rn_mask) { 707 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 708 goto on1; 709 } 710 if (--m->rm_refs >= 0) 711 goto on1; 712 } 713 b = -1 - tt->rn_b; 714 t = saved_tt->rn_p; 715 if (b > t->rn_b) 716 goto on1; /* Wasn't lifted at all */ 717 do { 718 x = t; 719 t = t->rn_p; 720 } while (b <= t->rn_b && x != top); 721 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 722 if (m == saved_m) { 723 *mp = m->rm_mklist; 724 MKFree(m); 725 break; 726 } 727 if (m == NULL) { 728 log(LOG_ERR, "rn_delete: couldn't find our annotation\n"); 729 if (tt->rn_flags & RNF_NORMAL) 730 return (0); /* Dangling ref to us */ 731 } 732 on1: 733 /* 734 * Eliminate us from tree 735 */ 736 if (tt->rn_flags & RNF_ROOT) 737 return (0); 738 #ifdef RN_DEBUG 739 /* Get us out of the creation list */ 740 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {} 741 if (t) t->rn_ybro = tt->rn_ybro; 742 #endif 743 t = tt->rn_p; 744 if ((dupedkey = saved_tt->rn_dupedkey)) { 745 if (tt == saved_tt) { 746 x = dupedkey; x->rn_p = t; 747 if (t->rn_l == tt) t->rn_l = x; else t->rn_r = x; 748 } else { 749 for (x = p = saved_tt; p && p->rn_dupedkey != tt;) 750 p = p->rn_dupedkey; 751 if (p) p->rn_dupedkey = tt->rn_dupedkey; 752 else log(LOG_ERR, "rn_delete: couldn't find us\n"); 753 } 754 t = tt + 1; 755 if (t->rn_flags & RNF_ACTIVE) { 756 #ifndef RN_DEBUG 757 *++x = *t; p = t->rn_p; 758 #else 759 b = t->rn_info; *++x = *t; t->rn_info = b; p = t->rn_p; 760 #endif 761 if (p->rn_l == t) p->rn_l = x; else p->rn_r = x; 762 x->rn_l->rn_p = x; x->rn_r->rn_p = x; 763 } 764 goto out; 765 } 766 if (t->rn_l == tt) x = t->rn_r; else x = t->rn_l; 767 p = t->rn_p; 768 if (p->rn_r == t) p->rn_r = x; else p->rn_l = x; 769 x->rn_p = p; 770 /* 771 * Demote routes attached to us. 772 */ 773 if (t->rn_mklist) { 774 if (x->rn_b >= 0) { 775 for (mp = &x->rn_mklist; (m = *mp);) 776 mp = &m->rm_mklist; 777 *mp = t->rn_mklist; 778 } else { 779 /* If there are any key,mask pairs in a sibling 780 duped-key chain, some subset will appear sorted 781 in the same order attached to our mklist */ 782 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey) 783 if (m == x->rn_mklist) { 784 struct radix_mask *mm = m->rm_mklist; 785 x->rn_mklist = 0; 786 if (--(m->rm_refs) < 0) 787 MKFree(m); 788 m = mm; 789 } 790 if (m) 791 syslog(LOG_ERR, "%s 0x%lx at 0x%lx\n", 792 "rn_delete: Orphaned Mask", 793 (unsigned long)m, 794 (unsigned long)x); 795 } 796 } 797 /* 798 * We may be holding an active internal node in the tree. 799 */ 800 x = tt + 1; 801 if (t != x) { 802 #ifndef RN_DEBUG 803 *t = *x; 804 #else 805 b = t->rn_info; *t = *x; t->rn_info = b; 806 #endif 807 t->rn_l->rn_p = t; t->rn_r->rn_p = t; 808 p = x->rn_p; 809 if (p->rn_l == x) p->rn_l = t; else p->rn_r = t; 810 } 811 out: 812 tt->rn_flags &= ~RNF_ACTIVE; 813 tt[1].rn_flags &= ~RNF_ACTIVE; 814 return (tt); 815 } 816 817 int 818 rn_walktree(struct radix_node_head *h, 819 int (*f)(struct radix_node *, struct walkarg *), 820 struct walkarg *w) 821 { 822 int error; 823 struct radix_node *base, *next; 824 struct radix_node *rn = h->rnh_treetop; 825 /* 826 * This gets complicated because we may delete the node 827 * while applying the function f to it, so we need to calculate 828 * the successor node in advance. 829 */ 830 /* First time through node, go left */ 831 while (rn->rn_b >= 0) 832 rn = rn->rn_l; 833 for (;;) { 834 base = rn; 835 /* If at right child go back up, otherwise, go right */ 836 while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0) 837 rn = rn->rn_p; 838 /* Find the next *leaf* since next node might vanish, too */ 839 for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;) 840 rn = rn->rn_l; 841 next = rn; 842 /* Process leaves */ 843 while ((rn = base)) { 844 base = rn->rn_dupedkey; 845 if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w))) 846 return (error); 847 } 848 rn = next; 849 if (rn->rn_flags & RNF_ROOT) 850 return (0); 851 } 852 /* NOTREACHED */ 853 } 854 855 int 856 rn_inithead(struct radix_node_head **head, int off) 857 { 858 struct radix_node_head *rnh; 859 struct radix_node *t, *tt, *ttt; 860 if (*head) 861 return (1); 862 rnh = (struct radix_node_head *)rtmalloc(sizeof(*rnh), "rn_inithead"); 863 Bzero(rnh, sizeof (*rnh)); 864 *head = rnh; 865 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes); 866 ttt = rnh->rnh_nodes + 2; 867 t->rn_r = ttt; 868 t->rn_p = t; 869 tt = t->rn_l; 870 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE; 871 tt->rn_b = -1 - off; 872 *ttt = *tt; 873 ttt->rn_key = rn_ones; 874 rnh->rnh_addaddr = rn_addroute; 875 rnh->rnh_deladdr = rn_delete; 876 rnh->rnh_matchaddr = rn_match; 877 rnh->rnh_lookup = rn_lookup; 878 rnh->rnh_walktree = rn_walktree; 879 rnh->rnh_treetop = t; 880 return (1); 881 } 882 883 void 884 rn_init(void) 885 { 886 char *cp, *cplim; 887 if (max_keylen == 0) { 888 printf("rn_init: radix functions require max_keylen be set\n"); 889 return; 890 } 891 rn_zeros = (char *)rtmalloc(3 * max_keylen, "rn_init"); 892 Bzero(rn_zeros, 3 * max_keylen); 893 rn_ones = cp = rn_zeros + max_keylen; 894 addmask_key = cplim = rn_ones + max_keylen; 895 while (cp < cplim) 896 *cp++ = -1; 897 if (rn_inithead(&mask_rnhead, 0) == 0) 898 panic("rn_init 2"); 899 } 900 901