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 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)radix.c 8.4 (Berkeley) 11/2/94 30 * 31 * $FreeBSD$ 32 */ 33 34/* 35 * Routines to build and maintain radix trees for routing lookups. 36 */ 37 38#include "defs.h" 39 40#ifdef __NetBSD__ 41__RCSID("$NetBSD$"); 42#elif defined(__FreeBSD__) 43__RCSID("$FreeBSD$"); 44#else 45__RCSID("$Revision: 2.23 $"); 46#ident "$Revision: 2.23 $" 47#endif 48 49#define log(x, msg) syslog(x, msg) 50#define panic(s) {log(LOG_ERR,s); exit(1);} 51#define min(a,b) (((a)<(b))?(a):(b)) 52 53int max_keylen; 54static struct radix_mask *rn_mkfreelist; 55static struct radix_node_head *mask_rnhead; 56static char *addmask_key; 57static const uint8_t normal_chars[] = 58 { 0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff}; 59static char *rn_zeros, *rn_ones; 60 61#define rn_masktop (mask_rnhead->rnh_treetop) 62#define Bcmp(a, b, l) (l == 0 ? 0 \ 63 : memcmp((caddr_t)(a), (caddr_t)(b), (size_t)l)) 64 65static int rn_satisfies_leaf(char *, struct radix_node *, int); 66static struct radix_node *rn_addmask(void *n_arg, int search, int skip); 67static struct radix_node *rn_addroute(void *v_arg, void *n_arg, 68 struct radix_node_head *head, struct radix_node treenodes[2]); 69static struct radix_node *rn_match(void *v_arg, struct radix_node_head *head); 70 71/* 72 * The data structure for the keys is a radix tree with one way 73 * branching removed. The index rn_b at an internal node n represents a bit 74 * position to be tested. The tree is arranged so that all descendants 75 * of a node n have keys whose bits all agree up to position rn_b - 1. 76 * (We say the index of n is rn_b.) 77 * 78 * There is at least one descendant which has a one bit at position rn_b, 79 * and at least one with a zero there. 80 * 81 * A route is determined by a pair of key and mask. We require that the 82 * bit-wise logical and of the key and mask to be the key. 83 * We define the index of a route to associated with the mask to be 84 * the first bit number in the mask where 0 occurs (with bit number 0 85 * representing the highest order bit). 86 * 87 * We say a mask is normal if every bit is 0, past the index of the mask. 88 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_b, 89 * and m is a normal mask, then the route applies to every descendant of n. 90 * If the index(m) < rn_b, this implies the trailing last few bits of k 91 * before bit b are all 0, (and hence consequently true of every descendant 92 * of n), so the route applies to all descendants of the node as well. 93 * 94 * Similar logic shows that a non-normal mask m such that 95 * index(m) <= index(n) could potentially apply to many children of n. 96 * Thus, for each non-host route, we attach its mask to a list at an internal 97 * node as high in the tree as we can go. 98 * 99 * The present version of the code makes use of normal routes in short- 100 * circuiting an explicit mask and compare operation when testing whether 101 * a key satisfies a normal route, and also in remembering the unique leaf 102 * that governs a subtree. 103 */ 104 105static struct radix_node * 106rn_search(void *v_arg, 107 struct radix_node *head) 108{ 109 struct radix_node *x; 110 caddr_t v; 111 112 for (x = head, v = v_arg; x->rn_b >= 0;) { 113 if (x->rn_bmask & v[x->rn_off]) 114 x = x->rn_r; 115 else 116 x = x->rn_l; 117 } 118 return (x); 119} 120 121static struct radix_node * 122rn_search_m(void *v_arg, 123 struct radix_node *head, 124 void *m_arg) 125{ 126 struct radix_node *x; 127 caddr_t v = v_arg, m = m_arg; 128 129 for (x = head; x->rn_b >= 0;) { 130 if ((x->rn_bmask & m[x->rn_off]) && 131 (x->rn_bmask & v[x->rn_off])) 132 x = x->rn_r; 133 else 134 x = x->rn_l; 135 } 136 return x; 137} 138 139static int 140rn_refines(void* m_arg, void *n_arg) 141{ 142 caddr_t m = m_arg, n = n_arg; 143 caddr_t lim, lim2 = lim = n + *(u_char *)n; 144 int longer = (*(u_char *)n++) - (int)(*(u_char *)m++); 145 int masks_are_equal = 1; 146 147 if (longer > 0) 148 lim -= longer; 149 while (n < lim) { 150 if (*n & ~(*m)) 151 return 0; 152 if (*n++ != *m++) 153 masks_are_equal = 0; 154 } 155 while (n < lim2) 156 if (*n++) 157 return 0; 158 if (masks_are_equal && (longer < 0)) 159 for (lim2 = m - longer; m < lim2; ) 160 if (*m++) 161 return 1; 162 return (!masks_are_equal); 163} 164 165static struct radix_node * 166rn_lookup(void *v_arg, void *m_arg, struct radix_node_head *head) 167{ 168 struct radix_node *x; 169 caddr_t netmask = 0; 170 171 if (m_arg) { 172 if ((x = rn_addmask(m_arg, 1, 173 head->rnh_treetop->rn_off)) == NULL) 174 return (0); 175 netmask = x->rn_key; 176 } 177 x = rn_match(v_arg, head); 178 if (x && netmask) { 179 while (x && x->rn_mask != netmask) 180 x = x->rn_dupedkey; 181 } 182 return x; 183} 184 185static int 186rn_satisfies_leaf(char *trial, 187 struct radix_node *leaf, 188 int skip) 189{ 190 char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask; 191 char *cplim; 192 int length = min(*(u_char *)cp, *(u_char *)cp2); 193 194 if (cp3 == NULL) 195 cp3 = rn_ones; 196 else 197 length = min(length, *(u_char *)cp3); 198 cplim = cp + length; cp3 += skip; cp2 += skip; 199 for (cp += skip; cp < cplim; cp++, cp2++, cp3++) 200 if ((*cp ^ *cp2) & *cp3) 201 return 0; 202 return 1; 203} 204 205static struct radix_node * 206rn_match(void *v_arg, 207 struct radix_node_head *head) 208{ 209 caddr_t v = v_arg; 210 struct radix_node *t = head->rnh_treetop, *x; 211 caddr_t cp = v, cp2; 212 caddr_t cplim; 213 struct radix_node *saved_t, *top = t; 214 int off = t->rn_off, vlen = *(u_char *)cp, matched_off; 215 int test, b, rn_b; 216 217 /* 218 * Open code rn_search(v, top) to avoid overhead of extra 219 * subroutine call. 220 */ 221 for (; t->rn_b >= 0; ) { 222 if (t->rn_bmask & cp[t->rn_off]) 223 t = t->rn_r; 224 else 225 t = t->rn_l; 226 } 227 /* 228 * See if we match exactly as a host destination 229 * or at least learn how many bits match, for normal mask finesse. 230 * 231 * It doesn't hurt us to limit how many bytes to check 232 * to the length of the mask, since if it matches we had a genuine 233 * match and the leaf we have is the most specific one anyway; 234 * if it didn't match with a shorter length it would fail 235 * with a long one. This wins big for class B&C netmasks which 236 * are probably the most common case... 237 */ 238 if (t->rn_mask) 239 vlen = *(u_char *)t->rn_mask; 240 cp += off; cp2 = t->rn_key + off; cplim = v + vlen; 241 for (; cp < cplim; cp++, cp2++) 242 if (*cp != *cp2) 243 goto on1; 244 /* 245 * This extra grot is in case we are explicitly asked 246 * to look up the default. Ugh! 247 * Or 255.255.255.255 248 * 249 * In this case, we have a complete match of the key. Unless 250 * the node is one of the roots, we are finished. 251 * If it is the zeros root, then take what we have, preferring 252 * any real data. 253 * If it is the ones root, then pretend the target key was followed 254 * by a byte of zeros. 255 */ 256 if (!(t->rn_flags & RNF_ROOT)) 257 return t; /* not a root */ 258 if (t->rn_dupedkey) { 259 t = t->rn_dupedkey; 260 return t; /* have some real data */ 261 } 262 if (*(cp-1) == 0) 263 return t; /* not the ones root */ 264 b = 0; /* fake a zero after 255.255.255.255 */ 265 goto on2; 266on1: 267 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */ 268 for (b = 7; (test >>= 1) > 0;) 269 b--; 270on2: 271 matched_off = cp - v; 272 b += matched_off << 3; 273 rn_b = -1 - b; 274 /* 275 * If there is a host route in a duped-key chain, it will be first. 276 */ 277 if ((saved_t = t)->rn_mask == 0) 278 t = t->rn_dupedkey; 279 for (; t; t = t->rn_dupedkey) { 280 /* 281 * Even if we don't match exactly as a host, 282 * we may match if the leaf we wound up at is 283 * a route to a net. 284 */ 285 if (t->rn_flags & RNF_NORMAL) { 286 if (rn_b <= t->rn_b) 287 return t; 288 } else if (rn_satisfies_leaf(v, t, matched_off)) { 289 return t; 290 } 291 } 292 t = saved_t; 293 /* start searching up the tree */ 294 do { 295 struct radix_mask *m; 296 t = t->rn_p; 297 if ((m = t->rn_mklist)) { 298 /* 299 * If non-contiguous masks ever become important 300 * we can restore the masking and open coding of 301 * the search and satisfaction test and put the 302 * calculation of "off" back before the "do". 303 */ 304 do { 305 if (m->rm_flags & RNF_NORMAL) { 306 if (rn_b <= m->rm_b) 307 return (m->rm_leaf); 308 } else { 309 off = min(t->rn_off, matched_off); 310 x = rn_search_m(v, t, m->rm_mask); 311 while (x && x->rn_mask != m->rm_mask) 312 x = x->rn_dupedkey; 313 if (x && rn_satisfies_leaf(v, x, off)) 314 return x; 315 } 316 } while ((m = m->rm_mklist)); 317 } 318 } while (t != top); 319 return 0; 320} 321 322#ifdef RN_DEBUG 323int rn_nodenum; 324struct radix_node *rn_clist; 325int rn_saveinfo; 326int rn_debug = 1; 327#endif 328 329static struct radix_node * 330rn_newpair(void *v, int b, struct radix_node nodes[2]) 331{ 332 struct radix_node *tt = nodes, *t = tt + 1; 333 t->rn_b = b; t->rn_bmask = 0x80 >> (b & 7); 334 t->rn_l = tt; t->rn_off = b >> 3; 335 tt->rn_b = -1; tt->rn_key = (caddr_t)v; tt->rn_p = t; 336 tt->rn_flags = t->rn_flags = RNF_ACTIVE; 337#ifdef RN_DEBUG 338 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 339 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 340#endif 341 return t; 342} 343 344static struct radix_node * 345rn_insert(void* v_arg, 346 struct radix_node_head *head, 347 int *dupentry, 348 struct radix_node nodes[2]) 349{ 350 caddr_t v = v_arg; 351 struct radix_node *top = head->rnh_treetop; 352 int head_off = top->rn_off, vlen = (int)*((u_char *)v); 353 struct radix_node *t = rn_search(v_arg, top); 354 caddr_t cp = v + head_off; 355 int b; 356 struct radix_node *tt; 357 358 /* 359 * Find first bit at which v and t->rn_key differ 360 */ 361 { 362 caddr_t cp2 = t->rn_key + head_off; 363 int cmp_res; 364 caddr_t cplim = v + vlen; 365 366 while (cp < cplim) 367 if (*cp2++ != *cp++) 368 goto on1; 369 /* handle adding 255.255.255.255 */ 370 if (!(t->rn_flags & RNF_ROOT) || *(cp2-1) == 0) { 371 *dupentry = 1; 372 return t; 373 } 374on1: 375 *dupentry = 0; 376 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff; 377 for (b = (cp - v) << 3; cmp_res; b--) 378 cmp_res >>= 1; 379 } 380 { 381 struct radix_node *p, *x = top; 382 cp = v; 383 do { 384 p = x; 385 if (cp[x->rn_off] & x->rn_bmask) 386 x = x->rn_r; 387 else x = x->rn_l; 388 } while ((unsigned)b > (unsigned)x->rn_b); 389#ifdef RN_DEBUG 390 if (rn_debug) 391 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p); 392#endif 393 t = rn_newpair(v_arg, b, nodes); tt = t->rn_l; 394 if ((cp[p->rn_off] & p->rn_bmask) == 0) 395 p->rn_l = t; 396 else 397 p->rn_r = t; 398 x->rn_p = t; t->rn_p = p; /* frees x, p as temp vars below */ 399 if ((cp[t->rn_off] & t->rn_bmask) == 0) { 400 t->rn_r = x; 401 } else { 402 t->rn_r = tt; t->rn_l = x; 403 } 404#ifdef RN_DEBUG 405 if (rn_debug) 406 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p); 407#endif 408 } 409 return (tt); 410} 411 412static struct radix_node * 413rn_addmask(void *n_arg, int search, int skip) 414{ 415 caddr_t netmask = (caddr_t)n_arg; 416 struct radix_node *x; 417 caddr_t cp, cplim; 418 int b = 0, mlen, j; 419 int maskduplicated, m0, isnormal; 420 struct radix_node *saved_x; 421 static int last_zeroed = 0; 422 423 if ((mlen = *(u_char *)netmask) > max_keylen) 424 mlen = max_keylen; 425 if (skip == 0) 426 skip = 1; 427 if (mlen <= skip) 428 return (mask_rnhead->rnh_nodes); 429 if (skip > 1) 430 Bcopy(rn_ones + 1, addmask_key + 1, skip - 1); 431 if ((m0 = mlen) > skip) 432 Bcopy(netmask + skip, addmask_key + skip, mlen - skip); 433 /* 434 * Trim trailing zeroes. 435 */ 436 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;) 437 cp--; 438 mlen = cp - addmask_key; 439 if (mlen <= skip) { 440 if (m0 >= last_zeroed) 441 last_zeroed = mlen; 442 return (mask_rnhead->rnh_nodes); 443 } 444 if (m0 < last_zeroed) 445 Bzero(addmask_key + m0, last_zeroed - m0); 446 *addmask_key = last_zeroed = mlen; 447 x = rn_search(addmask_key, rn_masktop); 448 if (Bcmp(addmask_key, x->rn_key, mlen) != 0) 449 x = NULL; 450 if (x || search) 451 return (x); 452 x = (struct radix_node *)rtmalloc(max_keylen + 2*sizeof(*x), 453 "rn_addmask"); 454 saved_x = x; 455 Bzero(x, max_keylen + 2 * sizeof (*x)); 456 netmask = cp = (caddr_t)(x + 2); 457 Bcopy(addmask_key, cp, mlen); 458 x = rn_insert(cp, mask_rnhead, &maskduplicated, x); 459 if (maskduplicated) { 460 log(LOG_ERR, "rn_addmask: mask impossibly already in tree"); 461 Free(saved_x); 462 return (x); 463 } 464 /* 465 * Calculate index of mask, and check for normalcy. 466 */ 467 cplim = netmask + mlen; isnormal = 1; 468 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;) 469 cp++; 470 if (cp != cplim) { 471 for (j = 0x80; (j & *cp) != 0; j >>= 1) 472 b++; 473 if (*cp != normal_chars[b] || cp != (cplim - 1)) 474 isnormal = 0; 475 } 476 b += (cp - netmask) << 3; 477 x->rn_b = -1 - b; 478 if (isnormal) 479 x->rn_flags |= RNF_NORMAL; 480 return (x); 481} 482 483static int /* XXX: arbitrary ordering for non-contiguous masks */ 484rn_lexobetter(void *m_arg, void *n_arg) 485{ 486 u_char *mp = m_arg, *np = n_arg, *lim; 487 488 if (*mp > *np) 489 return 1; /* not really, but need to check longer one first */ 490 if (*mp == *np) 491 for (lim = mp + *mp; mp < lim;) 492 if (*mp++ > *np++) 493 return 1; 494 return 0; 495} 496 497static struct radix_mask * 498rn_new_radix_mask(struct radix_node *tt, 499 struct radix_mask *next) 500{ 501 struct radix_mask *m; 502 503 MKGet(m); 504 if (m == NULL) { 505 log(LOG_ERR, "Mask for route not entered\n"); 506 return (0); 507 } 508 Bzero(m, sizeof *m); 509 m->rm_b = tt->rn_b; 510 m->rm_flags = tt->rn_flags; 511 if (tt->rn_flags & RNF_NORMAL) 512 m->rm_leaf = tt; 513 else 514 m->rm_mask = tt->rn_mask; 515 m->rm_mklist = next; 516 tt->rn_mklist = m; 517 return m; 518} 519 520static struct radix_node * 521rn_addroute(void *v_arg, 522 void *n_arg, 523 struct radix_node_head *head, 524 struct radix_node treenodes[2]) 525{ 526 caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg; 527 struct radix_node *t, *x = NULL, *tt; 528 struct radix_node *saved_tt, *top = head->rnh_treetop; 529 short b = 0, b_leaf = 0; 530 int keyduplicated; 531 caddr_t mmask; 532 struct radix_mask *m, **mp; 533 534 /* 535 * In dealing with non-contiguous masks, there may be 536 * many different routes which have the same mask. 537 * We will find it useful to have a unique pointer to 538 * the mask to speed avoiding duplicate references at 539 * nodes and possibly save time in calculating indices. 540 */ 541 if (netmask) { 542 if ((x = rn_addmask(netmask, 0, top->rn_off)) == NULL) 543 return (0); 544 b_leaf = x->rn_b; 545 b = -1 - x->rn_b; 546 netmask = x->rn_key; 547 } 548 /* 549 * Deal with duplicated keys: attach node to previous instance 550 */ 551 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes); 552 if (keyduplicated) { 553 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) { 554 if (tt->rn_mask == netmask) 555 return (0); 556 if (netmask == 0 || 557 (tt->rn_mask && 558 ((b_leaf < tt->rn_b) || /* index(netmask) > node */ 559 rn_refines(netmask, tt->rn_mask) || 560 rn_lexobetter(netmask, tt->rn_mask)))) 561 break; 562 } 563 /* 564 * If the mask is not duplicated, we wouldn't 565 * find it among possible duplicate key entries 566 * anyway, so the above test doesn't hurt. 567 * 568 * We sort the masks for a duplicated key the same way as 569 * in a masklist -- most specific to least specific. 570 * This may require the unfortunate nuisance of relocating 571 * the head of the list. 572 */ 573 if (tt == saved_tt) { 574 struct radix_node *xx = x; 575 /* link in at head of list */ 576 (tt = treenodes)->rn_dupedkey = t; 577 tt->rn_flags = t->rn_flags; 578 tt->rn_p = x = t->rn_p; 579 if (x->rn_l == t) x->rn_l = tt; else x->rn_r = tt; 580 saved_tt = tt; x = xx; 581 } else { 582 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey; 583 t->rn_dupedkey = tt; 584 } 585#ifdef RN_DEBUG 586 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 587 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 588#endif 589 tt->rn_key = (caddr_t) v; 590 tt->rn_b = -1; 591 tt->rn_flags = RNF_ACTIVE; 592 } 593 /* 594 * Put mask in tree. 595 */ 596 if (netmask) { 597 tt->rn_mask = netmask; 598 tt->rn_b = x->rn_b; 599 tt->rn_flags |= x->rn_flags & RNF_NORMAL; 600 } 601 t = saved_tt->rn_p; 602 if (keyduplicated) 603 goto on2; 604 b_leaf = -1 - t->rn_b; 605 if (t->rn_r == saved_tt) x = t->rn_l; else x = t->rn_r; 606 /* Promote general routes from below */ 607 if (x->rn_b < 0) { 608 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey) 609 if (x->rn_mask && (x->rn_b >= b_leaf) && x->rn_mklist == 0) { 610 if ((*mp = m = rn_new_radix_mask(x, 0))) 611 mp = &m->rm_mklist; 612 } 613 } else if (x->rn_mklist) { 614 /* 615 * Skip over masks whose index is > that of new node 616 */ 617 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 618 if (m->rm_b >= b_leaf) 619 break; 620 t->rn_mklist = m; *mp = NULL; 621 } 622on2: 623 /* Add new route to highest possible ancestor's list */ 624 if ((netmask == 0) || (b > t->rn_b )) 625 return tt; /* can't lift at all */ 626 b_leaf = tt->rn_b; 627 do { 628 x = t; 629 t = t->rn_p; 630 } while (b <= t->rn_b && x != top); 631 /* 632 * Search through routes associated with node to 633 * insert new route according to index. 634 * Need same criteria as when sorting dupedkeys to avoid 635 * double loop on deletion. 636 */ 637 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) { 638 if (m->rm_b < b_leaf) 639 continue; 640 if (m->rm_b > b_leaf) 641 break; 642 if (m->rm_flags & RNF_NORMAL) { 643 mmask = m->rm_leaf->rn_mask; 644 if (tt->rn_flags & RNF_NORMAL) { 645 log(LOG_ERR, 646 "Non-unique normal route, mask not entered"); 647 return tt; 648 } 649 } else 650 mmask = m->rm_mask; 651 if (mmask == netmask) { 652 m->rm_refs++; 653 tt->rn_mklist = m; 654 return tt; 655 } 656 if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask)) 657 break; 658 } 659 *mp = rn_new_radix_mask(tt, *mp); 660 return tt; 661} 662 663static struct radix_node * 664rn_delete(void *v_arg, 665 void *netmask_arg, 666 struct radix_node_head *head) 667{ 668 struct radix_node *t, *p, *x, *tt; 669 struct radix_mask *m, *saved_m, **mp; 670 struct radix_node *dupedkey, *saved_tt, *top; 671 caddr_t v, netmask; 672 int b, head_off, vlen; 673 674 v = v_arg; 675 netmask = netmask_arg; 676 x = head->rnh_treetop; 677 tt = rn_search(v, x); 678 head_off = x->rn_off; 679 vlen = *(u_char *)v; 680 saved_tt = tt; 681 top = x; 682 if (tt == NULL || 683 Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off)) 684 return (0); 685 /* 686 * Delete our route from mask lists. 687 */ 688 if (netmask) { 689 if ((x = rn_addmask(netmask, 1, head_off)) == NULL) 690 return (0); 691 netmask = x->rn_key; 692 while (tt->rn_mask != netmask) 693 if ((tt = tt->rn_dupedkey) == NULL) 694 return (0); 695 } 696 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == NULL) 697 goto on1; 698 if (tt->rn_flags & RNF_NORMAL) { 699 if (m->rm_leaf != tt || m->rm_refs > 0) { 700 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 701 return 0; /* dangling ref could cause disaster */ 702 } 703 } else { 704 if (m->rm_mask != tt->rn_mask) { 705 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 706 goto on1; 707 } 708 if (--m->rm_refs >= 0) 709 goto on1; 710 } 711 b = -1 - tt->rn_b; 712 t = saved_tt->rn_p; 713 if (b > t->rn_b) 714 goto on1; /* Wasn't lifted at all */ 715 do { 716 x = t; 717 t = t->rn_p; 718 } while (b <= t->rn_b && x != top); 719 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 720 if (m == saved_m) { 721 *mp = m->rm_mklist; 722 MKFree(m); 723 break; 724 } 725 if (m == NULL) { 726 log(LOG_ERR, "rn_delete: couldn't find our annotation\n"); 727 if (tt->rn_flags & RNF_NORMAL) 728 return (0); /* Dangling ref to us */ 729 } 730on1: 731 /* 732 * Eliminate us from tree 733 */ 734 if (tt->rn_flags & RNF_ROOT) 735 return (0); 736#ifdef RN_DEBUG 737 /* Get us out of the creation list */ 738 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {} 739 if (t) t->rn_ybro = tt->rn_ybro; 740#endif 741 t = tt->rn_p; 742 if ((dupedkey = saved_tt->rn_dupedkey)) { 743 if (tt == saved_tt) { 744 x = dupedkey; x->rn_p = t; 745 if (t->rn_l == tt) t->rn_l = x; else t->rn_r = x; 746 } else { 747 for (x = p = saved_tt; p && p->rn_dupedkey != tt;) 748 p = p->rn_dupedkey; 749 if (p) p->rn_dupedkey = tt->rn_dupedkey; 750 else log(LOG_ERR, "rn_delete: couldn't find us\n"); 751 } 752 t = tt + 1; 753 if (t->rn_flags & RNF_ACTIVE) { 754#ifndef RN_DEBUG 755 *++x = *t; p = t->rn_p; 756#else 757 b = t->rn_info; *++x = *t; t->rn_info = b; p = t->rn_p; 758#endif 759 if (p->rn_l == t) p->rn_l = x; else p->rn_r = x; 760 x->rn_l->rn_p = x; x->rn_r->rn_p = x; 761 } 762 goto out; 763 } 764 if (t->rn_l == tt) x = t->rn_r; else x = t->rn_l; 765 p = t->rn_p; 766 if (p->rn_r == t) p->rn_r = x; else p->rn_l = x; 767 x->rn_p = p; 768 /* 769 * Demote routes attached to us. 770 */ 771 if (t->rn_mklist) { 772 if (x->rn_b >= 0) { 773 for (mp = &x->rn_mklist; (m = *mp);) 774 mp = &m->rm_mklist; 775 *mp = t->rn_mklist; 776 } else { 777 /* If there are any key,mask pairs in a sibling 778 duped-key chain, some subset will appear sorted 779 in the same order attached to our mklist */ 780 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey) 781 if (m == x->rn_mklist) { 782 struct radix_mask *mm = m->rm_mklist; 783 x->rn_mklist = 0; 784 if (--(m->rm_refs) < 0) 785 MKFree(m); 786 m = mm; 787 } 788 if (m) 789 syslog(LOG_ERR, "%s 0x%lx at 0x%lx\n", 790 "rn_delete: Orphaned Mask", 791 (unsigned long)m, 792 (unsigned long)x); 793 } 794 } 795 /* 796 * We may be holding an active internal node in the tree. 797 */ 798 x = tt + 1; 799 if (t != x) { 800#ifndef RN_DEBUG 801 *t = *x; 802#else 803 b = t->rn_info; *t = *x; t->rn_info = b; 804#endif 805 t->rn_l->rn_p = t; t->rn_r->rn_p = t; 806 p = x->rn_p; 807 if (p->rn_l == x) p->rn_l = t; else p->rn_r = t; 808 } 809out: 810 tt->rn_flags &= ~RNF_ACTIVE; 811 tt[1].rn_flags &= ~RNF_ACTIVE; 812 return (tt); 813} 814 815int 816rn_walktree(struct radix_node_head *h, 817 int (*f)(struct radix_node *, struct walkarg *), 818 struct walkarg *w) 819{ 820 int error; 821 struct radix_node *base, *next; 822 struct radix_node *rn = h->rnh_treetop; 823 /* 824 * This gets complicated because we may delete the node 825 * while applying the function f to it, so we need to calculate 826 * the successor node in advance. 827 */ 828 /* First time through node, go left */ 829 while (rn->rn_b >= 0) 830 rn = rn->rn_l; 831 for (;;) { 832 base = rn; 833 /* If at right child go back up, otherwise, go right */ 834 while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0) 835 rn = rn->rn_p; 836 /* Find the next *leaf* since next node might vanish, too */ 837 for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;) 838 rn = rn->rn_l; 839 next = rn; 840 /* Process leaves */ 841 while ((rn = base)) { 842 base = rn->rn_dupedkey; 843 if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w))) 844 return (error); 845 } 846 rn = next; 847 if (rn->rn_flags & RNF_ROOT) 848 return (0); 849 } 850 /* NOTREACHED */ 851} 852 853int 854rn_inithead(struct radix_node_head **head, int off) 855{ 856 struct radix_node_head *rnh; 857 struct radix_node *t, *tt, *ttt; 858 if (*head) 859 return (1); 860 rnh = (struct radix_node_head *)rtmalloc(sizeof(*rnh), "rn_inithead"); 861 Bzero(rnh, sizeof (*rnh)); 862 *head = rnh; 863 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes); 864 ttt = rnh->rnh_nodes + 2; 865 t->rn_r = ttt; 866 t->rn_p = t; 867 tt = t->rn_l; 868 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE; 869 tt->rn_b = -1 - off; 870 *ttt = *tt; 871 ttt->rn_key = rn_ones; 872 rnh->rnh_addaddr = rn_addroute; 873 rnh->rnh_deladdr = rn_delete; 874 rnh->rnh_matchaddr = rn_match; 875 rnh->rnh_lookup = rn_lookup; 876 rnh->rnh_walktree = rn_walktree; 877 rnh->rnh_treetop = t; 878 return (1); 879} 880 881void 882rn_init(void) 883{ 884 char *cp, *cplim; 885 if (max_keylen == 0) { 886 printf("rn_init: radix functions require max_keylen be set\n"); 887 return; 888 } 889 rn_zeros = (char *)rtmalloc(3 * max_keylen, "rn_init"); 890 Bzero(rn_zeros, 3 * max_keylen); 891 rn_ones = cp = rn_zeros + max_keylen; 892 addmask_key = cplim = rn_ones + max_keylen; 893 while (cp < cplim) 894 *cp++ = -1; 895 if (rn_inithead(&mask_rnhead, 0) == 0) 896 panic("rn_init 2"); 897} 898 899