radix.c revision 128433
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 8.5 (Berkeley) 5/19/95 30 * $FreeBSD: head/sys/net/radix.c 128433 2004-04-19 17:28:39Z luigi $ 31 */ 32 33/* 34 * Routines to build and maintain radix trees for routing lookups. 35 */ 36#ifndef _RADIX_H_ 37#include <sys/param.h> 38#ifdef _KERNEL 39#include <sys/lock.h> 40#include <sys/mutex.h> 41#include <sys/systm.h> 42#include <sys/malloc.h> 43#include <sys/domain.h> 44#else 45#include <stdlib.h> 46#endif 47#include <sys/syslog.h> 48#include <net/radix.h> 49#endif 50 51static int rn_walktree_from(struct radix_node_head *h, void *a, void *m, 52 walktree_f_t *f, void *w); 53static int rn_walktree(struct radix_node_head *, walktree_f_t *, void *); 54static struct radix_node 55 *rn_insert(void *, struct radix_node_head *, int *, 56 struct radix_node [2]), 57 *rn_newpair(void *, int, struct radix_node[2]), 58 *rn_search(void *, struct radix_node *), 59 *rn_search_m(void *, struct radix_node *, void *); 60 61static int max_keylen; 62static struct radix_mask *rn_mkfreelist; 63static struct radix_node_head *mask_rnhead; 64/* 65 * Work area -- the following point to 3 buffers of size max_keylen, 66 * allocated in this order in a block of memory malloc'ed by rn_init. 67 */ 68static char *rn_zeros, *rn_ones, *addmask_key; 69 70#define MKGet(m) { \ 71 if (rn_mkfreelist) { \ 72 m = rn_mkfreelist; \ 73 rn_mkfreelist = (m)->rm_mklist; \ 74 } else \ 75 R_Malloc(m, struct radix_mask *, sizeof (struct radix_mask)); } 76 77#define MKFree(m) { (m)->rm_mklist = rn_mkfreelist; rn_mkfreelist = (m);} 78 79#define rn_masktop (mask_rnhead->rnh_treetop) 80 81static int rn_lexobetter(void *m_arg, void *n_arg); 82static struct radix_mask * 83 rn_new_radix_mask(struct radix_node *tt, 84 struct radix_mask *next); 85static int rn_satisfies_leaf(char *trial, struct radix_node *leaf, 86 int skip); 87 88/* 89 * The data structure for the keys is a radix tree with one way 90 * branching removed. The index rn_bit at an internal node n represents a bit 91 * position to be tested. The tree is arranged so that all descendants 92 * of a node n have keys whose bits all agree up to position rn_bit - 1. 93 * (We say the index of n is rn_bit.) 94 * 95 * There is at least one descendant which has a one bit at position rn_bit, 96 * and at least one with a zero there. 97 * 98 * A route is determined by a pair of key and mask. We require that the 99 * bit-wise logical and of the key and mask to be the key. 100 * We define the index of a route to associated with the mask to be 101 * the first bit number in the mask where 0 occurs (with bit number 0 102 * representing the highest order bit). 103 * 104 * We say a mask is normal if every bit is 0, past the index of the mask. 105 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_bit, 106 * and m is a normal mask, then the route applies to every descendant of n. 107 * If the index(m) < rn_bit, this implies the trailing last few bits of k 108 * before bit b are all 0, (and hence consequently true of every descendant 109 * of n), so the route applies to all descendants of the node as well. 110 * 111 * Similar logic shows that a non-normal mask m such that 112 * index(m) <= index(n) could potentially apply to many children of n. 113 * Thus, for each non-host route, we attach its mask to a list at an internal 114 * node as high in the tree as we can go. 115 * 116 * The present version of the code makes use of normal routes in short- 117 * circuiting an explict mask and compare operation when testing whether 118 * a key satisfies a normal route, and also in remembering the unique leaf 119 * that governs a subtree. 120 */ 121 122static struct radix_node * 123rn_search(v_arg, head) 124 void *v_arg; 125 struct radix_node *head; 126{ 127 register struct radix_node *x; 128 register caddr_t v; 129 130 for (x = head, v = v_arg; x->rn_bit >= 0;) { 131 if (x->rn_bmask & v[x->rn_offset]) 132 x = x->rn_right; 133 else 134 x = x->rn_left; 135 } 136 return (x); 137} 138 139static struct radix_node * 140rn_search_m(v_arg, head, m_arg) 141 struct radix_node *head; 142 void *v_arg, *m_arg; 143{ 144 register struct radix_node *x; 145 register caddr_t v = v_arg, m = m_arg; 146 147 for (x = head; x->rn_bit >= 0;) { 148 if ((x->rn_bmask & m[x->rn_offset]) && 149 (x->rn_bmask & v[x->rn_offset])) 150 x = x->rn_right; 151 else 152 x = x->rn_left; 153 } 154 return x; 155} 156 157int 158rn_refines(m_arg, n_arg) 159 void *m_arg, *n_arg; 160{ 161 register caddr_t m = m_arg, n = n_arg; 162 register caddr_t lim, lim2 = lim = n + *(u_char *)n; 163 int longer = (*(u_char *)n++) - (int)(*(u_char *)m++); 164 int masks_are_equal = 1; 165 166 if (longer > 0) 167 lim -= longer; 168 while (n < lim) { 169 if (*n & ~(*m)) 170 return 0; 171 if (*n++ != *m++) 172 masks_are_equal = 0; 173 } 174 while (n < lim2) 175 if (*n++) 176 return 0; 177 if (masks_are_equal && (longer < 0)) 178 for (lim2 = m - longer; m < lim2; ) 179 if (*m++) 180 return 1; 181 return (!masks_are_equal); 182} 183 184struct radix_node * 185rn_lookup(v_arg, m_arg, head) 186 void *v_arg, *m_arg; 187 struct radix_node_head *head; 188{ 189 register struct radix_node *x; 190 caddr_t netmask = 0; 191 192 if (m_arg) { 193 x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_offset); 194 if (x == 0) 195 return (0); 196 netmask = x->rn_key; 197 } 198 x = rn_match(v_arg, head); 199 if (x && netmask) { 200 while (x && x->rn_mask != netmask) 201 x = x->rn_dupedkey; 202 } 203 return x; 204} 205 206static int 207rn_satisfies_leaf(trial, leaf, skip) 208 char *trial; 209 register struct radix_node *leaf; 210 int skip; 211{ 212 register char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask; 213 char *cplim; 214 int length = min(*(u_char *)cp, *(u_char *)cp2); 215 216 if (cp3 == 0) 217 cp3 = rn_ones; 218 else 219 length = min(length, *(u_char *)cp3); 220 cplim = cp + length; cp3 += skip; cp2 += skip; 221 for (cp += skip; cp < cplim; cp++, cp2++, cp3++) 222 if ((*cp ^ *cp2) & *cp3) 223 return 0; 224 return 1; 225} 226 227struct radix_node * 228rn_match(v_arg, head) 229 void *v_arg; 230 struct radix_node_head *head; 231{ 232 caddr_t v = v_arg; 233 register struct radix_node *t = head->rnh_treetop, *x; 234 register caddr_t cp = v, cp2; 235 caddr_t cplim; 236 struct radix_node *saved_t, *top = t; 237 int off = t->rn_offset, vlen = *(u_char *)cp, matched_off; 238 register int test, b, rn_bit; 239 240 /* 241 * Open code rn_search(v, top) to avoid overhead of extra 242 * subroutine call. 243 */ 244 for (; t->rn_bit >= 0; ) { 245 if (t->rn_bmask & cp[t->rn_offset]) 246 t = t->rn_right; 247 else 248 t = t->rn_left; 249 } 250 /* 251 * See if we match exactly as a host destination 252 * or at least learn how many bits match, for normal mask finesse. 253 * 254 * It doesn't hurt us to limit how many bytes to check 255 * to the length of the mask, since if it matches we had a genuine 256 * match and the leaf we have is the most specific one anyway; 257 * if it didn't match with a shorter length it would fail 258 * with a long one. This wins big for class B&C netmasks which 259 * are probably the most common case... 260 */ 261 if (t->rn_mask) 262 vlen = *(u_char *)t->rn_mask; 263 cp += off; cp2 = t->rn_key + off; cplim = v + vlen; 264 for (; cp < cplim; cp++, cp2++) 265 if (*cp != *cp2) 266 goto on1; 267 /* 268 * This extra grot is in case we are explicitly asked 269 * to look up the default. Ugh! 270 * 271 * Never return the root node itself, it seems to cause a 272 * lot of confusion. 273 */ 274 if (t->rn_flags & RNF_ROOT) 275 t = t->rn_dupedkey; 276 return t; 277on1: 278 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */ 279 for (b = 7; (test >>= 1) > 0;) 280 b--; 281 matched_off = cp - v; 282 b += matched_off << 3; 283 rn_bit = -1 - b; 284 /* 285 * If there is a host route in a duped-key chain, it will be first. 286 */ 287 if ((saved_t = t)->rn_mask == 0) 288 t = t->rn_dupedkey; 289 for (; t; t = t->rn_dupedkey) 290 /* 291 * Even if we don't match exactly as a host, 292 * we may match if the leaf we wound up at is 293 * a route to a net. 294 */ 295 if (t->rn_flags & RNF_NORMAL) { 296 if (rn_bit <= t->rn_bit) 297 return t; 298 } else if (rn_satisfies_leaf(v, t, matched_off)) 299 return t; 300 t = saved_t; 301 /* start searching up the tree */ 302 do { 303 register struct radix_mask *m; 304 t = t->rn_parent; 305 m = t->rn_mklist; 306 /* 307 * If non-contiguous masks ever become important 308 * we can restore the masking and open coding of 309 * the search and satisfaction test and put the 310 * calculation of "off" back before the "do". 311 */ 312 while (m) { 313 if (m->rm_flags & RNF_NORMAL) { 314 if (rn_bit <= m->rm_bit) 315 return (m->rm_leaf); 316 } else { 317 off = min(t->rn_offset, matched_off); 318 x = rn_search_m(v, t, m->rm_mask); 319 while (x && x->rn_mask != m->rm_mask) 320 x = x->rn_dupedkey; 321 if (x && rn_satisfies_leaf(v, x, off)) 322 return x; 323 } 324 m = m->rm_mklist; 325 } 326 } while (t != top); 327 return 0; 328} 329 330#ifdef RN_DEBUG 331int rn_nodenum; 332struct radix_node *rn_clist; 333int rn_saveinfo; 334int rn_debug = 1; 335#endif 336 337static struct radix_node * 338rn_newpair(v, b, nodes) 339 void *v; 340 int b; 341 struct radix_node nodes[2]; 342{ 343 register struct radix_node *tt = nodes, *t = tt + 1; 344 t->rn_bit = b; 345 t->rn_bmask = 0x80 >> (b & 7); 346 t->rn_left = tt; 347 t->rn_offset = b >> 3; 348 tt->rn_bit = -1; 349 tt->rn_key = (caddr_t)v; 350 tt->rn_parent = t; 351 tt->rn_flags = t->rn_flags = RNF_ACTIVE; 352 tt->rn_mklist = t->rn_mklist = 0; 353#ifdef RN_DEBUG 354 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 355 tt->rn_twin = t; 356 tt->rn_ybro = rn_clist; 357 rn_clist = tt; 358#endif 359 return t; 360} 361 362static struct radix_node * 363rn_insert(v_arg, head, dupentry, nodes) 364 void *v_arg; 365 struct radix_node_head *head; 366 int *dupentry; 367 struct radix_node nodes[2]; 368{ 369 caddr_t v = v_arg; 370 struct radix_node *top = head->rnh_treetop; 371 int head_off = top->rn_offset, vlen = (int)*((u_char *)v); 372 register struct radix_node *t = rn_search(v_arg, top); 373 register caddr_t cp = v + head_off; 374 register int b; 375 struct radix_node *tt; 376 /* 377 * Find first bit at which v and t->rn_key differ 378 */ 379 { 380 register caddr_t cp2 = t->rn_key + head_off; 381 register int cmp_res; 382 caddr_t cplim = v + vlen; 383 384 while (cp < cplim) 385 if (*cp2++ != *cp++) 386 goto on1; 387 *dupentry = 1; 388 return t; 389on1: 390 *dupentry = 0; 391 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff; 392 for (b = (cp - v) << 3; cmp_res; b--) 393 cmp_res >>= 1; 394 } 395 { 396 register struct radix_node *p, *x = top; 397 cp = v; 398 do { 399 p = x; 400 if (cp[x->rn_offset] & x->rn_bmask) 401 x = x->rn_right; 402 else 403 x = x->rn_left; 404 } while (b > (unsigned) x->rn_bit); 405 /* x->rn_bit < b && x->rn_bit >= 0 */ 406#ifdef RN_DEBUG 407 if (rn_debug) 408 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p); 409#endif 410 t = rn_newpair(v_arg, b, nodes); 411 tt = t->rn_left; 412 if ((cp[p->rn_offset] & p->rn_bmask) == 0) 413 p->rn_left = t; 414 else 415 p->rn_right = t; 416 x->rn_parent = t; 417 t->rn_parent = p; /* frees x, p as temp vars below */ 418 if ((cp[t->rn_offset] & t->rn_bmask) == 0) { 419 t->rn_right = x; 420 } else { 421 t->rn_right = tt; 422 t->rn_left = x; 423 } 424#ifdef RN_DEBUG 425 if (rn_debug) 426 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p); 427#endif 428 } 429 return (tt); 430} 431 432struct radix_node * 433rn_addmask(n_arg, search, skip) 434 int search, skip; 435 void *n_arg; 436{ 437 caddr_t netmask = (caddr_t)n_arg; 438 register struct radix_node *x; 439 register caddr_t cp, cplim; 440 register int b = 0, mlen, j; 441 int maskduplicated, m0, isnormal; 442 struct radix_node *saved_x; 443 static int last_zeroed = 0; 444 445 if ((mlen = *(u_char *)netmask) > max_keylen) 446 mlen = max_keylen; 447 if (skip == 0) 448 skip = 1; 449 if (mlen <= skip) 450 return (mask_rnhead->rnh_nodes); 451 if (skip > 1) 452 bcopy(rn_ones + 1, addmask_key + 1, skip - 1); 453 if ((m0 = mlen) > skip) 454 bcopy(netmask + skip, addmask_key + skip, mlen - skip); 455 /* 456 * Trim trailing zeroes. 457 */ 458 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;) 459 cp--; 460 mlen = cp - addmask_key; 461 if (mlen <= skip) { 462 if (m0 >= last_zeroed) 463 last_zeroed = mlen; 464 return (mask_rnhead->rnh_nodes); 465 } 466 if (m0 < last_zeroed) 467 bzero(addmask_key + m0, last_zeroed - m0); 468 *addmask_key = last_zeroed = mlen; 469 x = rn_search(addmask_key, rn_masktop); 470 if (bcmp(addmask_key, x->rn_key, mlen) != 0) 471 x = 0; 472 if (x || search) 473 return (x); 474 R_Zalloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x)); 475 if ((saved_x = x) == 0) 476 return (0); 477 netmask = cp = (caddr_t)(x + 2); 478 bcopy(addmask_key, cp, mlen); 479 x = rn_insert(cp, mask_rnhead, &maskduplicated, x); 480 if (maskduplicated) { 481 log(LOG_ERR, "rn_addmask: mask impossibly already in tree"); 482 Free(saved_x); 483 return (x); 484 } 485 /* 486 * Calculate index of mask, and check for normalcy. 487 * First find the first byte with a 0 bit, then if there are 488 * more bits left (remember we already trimmed the trailing 0's), 489 * the pattern must be one of those in normal_chars[], or we have 490 * a non-contiguous mask. 491 */ 492 cplim = netmask + mlen; 493 isnormal = 1; 494 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;) 495 cp++; 496 if (cp != cplim) { 497 static char normal_chars[] = { 498 0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff}; 499 500 for (j = 0x80; (j & *cp) != 0; j >>= 1) 501 b++; 502 if (*cp != normal_chars[b] || cp != (cplim - 1)) 503 isnormal = 0; 504 } 505 b += (cp - netmask) << 3; 506 x->rn_bit = -1 - b; 507 if (isnormal) 508 x->rn_flags |= RNF_NORMAL; 509 return (x); 510} 511 512static int /* XXX: arbitrary ordering for non-contiguous masks */ 513rn_lexobetter(m_arg, n_arg) 514 void *m_arg, *n_arg; 515{ 516 register u_char *mp = m_arg, *np = n_arg, *lim; 517 518 if (*mp > *np) 519 return 1; /* not really, but need to check longer one first */ 520 if (*mp == *np) 521 for (lim = mp + *mp; mp < lim;) 522 if (*mp++ > *np++) 523 return 1; 524 return 0; 525} 526 527static struct radix_mask * 528rn_new_radix_mask(tt, next) 529 register struct radix_node *tt; 530 register struct radix_mask *next; 531{ 532 register struct radix_mask *m; 533 534 MKGet(m); 535 if (m == 0) { 536 log(LOG_ERR, "Mask for route not entered\n"); 537 return (0); 538 } 539 bzero(m, sizeof *m); 540 m->rm_bit = tt->rn_bit; 541 m->rm_flags = tt->rn_flags; 542 if (tt->rn_flags & RNF_NORMAL) 543 m->rm_leaf = tt; 544 else 545 m->rm_mask = tt->rn_mask; 546 m->rm_mklist = next; 547 tt->rn_mklist = m; 548 return m; 549} 550 551struct radix_node * 552rn_addroute(v_arg, n_arg, head, treenodes) 553 void *v_arg, *n_arg; 554 struct radix_node_head *head; 555 struct radix_node treenodes[2]; 556{ 557 caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg; 558 register struct radix_node *t, *x = 0, *tt; 559 struct radix_node *saved_tt, *top = head->rnh_treetop; 560 short b = 0, b_leaf = 0; 561 int keyduplicated; 562 caddr_t mmask; 563 struct radix_mask *m, **mp; 564 565 /* 566 * In dealing with non-contiguous masks, there may be 567 * many different routes which have the same mask. 568 * We will find it useful to have a unique pointer to 569 * the mask to speed avoiding duplicate references at 570 * nodes and possibly save time in calculating indices. 571 */ 572 if (netmask) { 573 if ((x = rn_addmask(netmask, 0, top->rn_offset)) == 0) 574 return (0); 575 b_leaf = x->rn_bit; 576 b = -1 - x->rn_bit; 577 netmask = x->rn_key; 578 } 579 /* 580 * Deal with duplicated keys: attach node to previous instance 581 */ 582 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes); 583 if (keyduplicated) { 584 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) { 585 if (tt->rn_mask == netmask) 586 return (0); 587 if (netmask == 0 || 588 (tt->rn_mask && 589 ((b_leaf < tt->rn_bit) /* index(netmask) > node */ 590 || rn_refines(netmask, tt->rn_mask) 591 || rn_lexobetter(netmask, tt->rn_mask)))) 592 break; 593 } 594 /* 595 * If the mask is not duplicated, we wouldn't 596 * find it among possible duplicate key entries 597 * anyway, so the above test doesn't hurt. 598 * 599 * We sort the masks for a duplicated key the same way as 600 * in a masklist -- most specific to least specific. 601 * This may require the unfortunate nuisance of relocating 602 * the head of the list. 603 * 604 * We also reverse, or doubly link the list through the 605 * parent pointer. 606 */ 607 if (tt == saved_tt) { 608 struct radix_node *xx = x; 609 /* link in at head of list */ 610 (tt = treenodes)->rn_dupedkey = t; 611 tt->rn_flags = t->rn_flags; 612 tt->rn_parent = x = t->rn_parent; 613 t->rn_parent = tt; /* parent */ 614 if (x->rn_left == t) 615 x->rn_left = tt; 616 else 617 x->rn_right = tt; 618 saved_tt = tt; x = xx; 619 } else { 620 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey; 621 t->rn_dupedkey = tt; 622 tt->rn_parent = t; /* parent */ 623 if (tt->rn_dupedkey) /* parent */ 624 tt->rn_dupedkey->rn_parent = tt; /* parent */ 625 } 626#ifdef RN_DEBUG 627 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 628 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 629#endif 630 tt->rn_key = (caddr_t) v; 631 tt->rn_bit = -1; 632 tt->rn_flags = RNF_ACTIVE; 633 } 634 /* 635 * Put mask in tree. 636 */ 637 if (netmask) { 638 tt->rn_mask = netmask; 639 tt->rn_bit = x->rn_bit; 640 tt->rn_flags |= x->rn_flags & RNF_NORMAL; 641 } 642 t = saved_tt->rn_parent; 643 if (keyduplicated) 644 goto on2; 645 b_leaf = -1 - t->rn_bit; 646 if (t->rn_right == saved_tt) 647 x = t->rn_left; 648 else 649 x = t->rn_right; 650 /* Promote general routes from below */ 651 if (x->rn_bit < 0) { 652 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey) 653 if (x->rn_mask && (x->rn_bit >= b_leaf) && x->rn_mklist == 0) { 654 *mp = m = rn_new_radix_mask(x, 0); 655 if (m) 656 mp = &m->rm_mklist; 657 } 658 } else if (x->rn_mklist) { 659 /* 660 * Skip over masks whose index is > that of new node 661 */ 662 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 663 if (m->rm_bit >= b_leaf) 664 break; 665 t->rn_mklist = m; *mp = 0; 666 } 667on2: 668 /* Add new route to highest possible ancestor's list */ 669 if ((netmask == 0) || (b > t->rn_bit )) 670 return tt; /* can't lift at all */ 671 b_leaf = tt->rn_bit; 672 do { 673 x = t; 674 t = t->rn_parent; 675 } while (b <= t->rn_bit && x != top); 676 /* 677 * Search through routes associated with node to 678 * insert new route according to index. 679 * Need same criteria as when sorting dupedkeys to avoid 680 * double loop on deletion. 681 */ 682 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) { 683 if (m->rm_bit < b_leaf) 684 continue; 685 if (m->rm_bit > b_leaf) 686 break; 687 if (m->rm_flags & RNF_NORMAL) { 688 mmask = m->rm_leaf->rn_mask; 689 if (tt->rn_flags & RNF_NORMAL) { 690 log(LOG_ERR, 691 "Non-unique normal route, mask not entered\n"); 692 return tt; 693 } 694 } else 695 mmask = m->rm_mask; 696 if (mmask == netmask) { 697 m->rm_refs++; 698 tt->rn_mklist = m; 699 return tt; 700 } 701 if (rn_refines(netmask, mmask) 702 || rn_lexobetter(netmask, mmask)) 703 break; 704 } 705 *mp = rn_new_radix_mask(tt, *mp); 706 return tt; 707} 708 709struct radix_node * 710rn_delete(v_arg, netmask_arg, head) 711 void *v_arg, *netmask_arg; 712 struct radix_node_head *head; 713{ 714 register struct radix_node *t, *p, *x, *tt; 715 struct radix_mask *m, *saved_m, **mp; 716 struct radix_node *dupedkey, *saved_tt, *top; 717 caddr_t v, netmask; 718 int b, head_off, vlen; 719 720 v = v_arg; 721 netmask = netmask_arg; 722 x = head->rnh_treetop; 723 tt = rn_search(v, x); 724 head_off = x->rn_offset; 725 vlen = *(u_char *)v; 726 saved_tt = tt; 727 top = x; 728 if (tt == 0 || 729 bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off)) 730 return (0); 731 /* 732 * Delete our route from mask lists. 733 */ 734 if (netmask) { 735 if ((x = rn_addmask(netmask, 1, head_off)) == 0) 736 return (0); 737 netmask = x->rn_key; 738 while (tt->rn_mask != netmask) 739 if ((tt = tt->rn_dupedkey) == 0) 740 return (0); 741 } 742 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0) 743 goto on1; 744 if (tt->rn_flags & RNF_NORMAL) { 745 if (m->rm_leaf != tt || m->rm_refs > 0) { 746 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 747 return 0; /* dangling ref could cause disaster */ 748 } 749 } else { 750 if (m->rm_mask != tt->rn_mask) { 751 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 752 goto on1; 753 } 754 if (--m->rm_refs >= 0) 755 goto on1; 756 } 757 b = -1 - tt->rn_bit; 758 t = saved_tt->rn_parent; 759 if (b > t->rn_bit) 760 goto on1; /* Wasn't lifted at all */ 761 do { 762 x = t; 763 t = t->rn_parent; 764 } while (b <= t->rn_bit && x != top); 765 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 766 if (m == saved_m) { 767 *mp = m->rm_mklist; 768 MKFree(m); 769 break; 770 } 771 if (m == 0) { 772 log(LOG_ERR, "rn_delete: couldn't find our annotation\n"); 773 if (tt->rn_flags & RNF_NORMAL) 774 return (0); /* Dangling ref to us */ 775 } 776on1: 777 /* 778 * Eliminate us from tree 779 */ 780 if (tt->rn_flags & RNF_ROOT) 781 return (0); 782#ifdef RN_DEBUG 783 /* Get us out of the creation list */ 784 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {} 785 if (t) t->rn_ybro = tt->rn_ybro; 786#endif 787 t = tt->rn_parent; 788 dupedkey = saved_tt->rn_dupedkey; 789 if (dupedkey) { 790 /* 791 * Here, tt is the deletion target and 792 * saved_tt is the head of the dupekey chain. 793 */ 794 if (tt == saved_tt) { 795 /* remove from head of chain */ 796 x = dupedkey; x->rn_parent = t; 797 if (t->rn_left == tt) 798 t->rn_left = x; 799 else 800 t->rn_right = x; 801 } else { 802 /* find node in front of tt on the chain */ 803 for (x = p = saved_tt; p && p->rn_dupedkey != tt;) 804 p = p->rn_dupedkey; 805 if (p) { 806 p->rn_dupedkey = tt->rn_dupedkey; 807 if (tt->rn_dupedkey) /* parent */ 808 tt->rn_dupedkey->rn_parent = p; 809 /* parent */ 810 } else log(LOG_ERR, "rn_delete: couldn't find us\n"); 811 } 812 t = tt + 1; 813 if (t->rn_flags & RNF_ACTIVE) { 814#ifndef RN_DEBUG 815 *++x = *t; 816 p = t->rn_parent; 817#else 818 b = t->rn_info; 819 *++x = *t; 820 t->rn_info = b; 821 p = t->rn_parent; 822#endif 823 if (p->rn_left == t) 824 p->rn_left = x; 825 else 826 p->rn_right = x; 827 x->rn_left->rn_parent = x; 828 x->rn_right->rn_parent = x; 829 } 830 goto out; 831 } 832 if (t->rn_left == tt) 833 x = t->rn_right; 834 else 835 x = t->rn_left; 836 p = t->rn_parent; 837 if (p->rn_right == t) 838 p->rn_right = x; 839 else 840 p->rn_left = x; 841 x->rn_parent = p; 842 /* 843 * Demote routes attached to us. 844 */ 845 if (t->rn_mklist) { 846 if (x->rn_bit >= 0) { 847 for (mp = &x->rn_mklist; (m = *mp);) 848 mp = &m->rm_mklist; 849 *mp = t->rn_mklist; 850 } else { 851 /* If there are any key,mask pairs in a sibling 852 duped-key chain, some subset will appear sorted 853 in the same order attached to our mklist */ 854 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey) 855 if (m == x->rn_mklist) { 856 struct radix_mask *mm = m->rm_mklist; 857 x->rn_mklist = 0; 858 if (--(m->rm_refs) < 0) 859 MKFree(m); 860 m = mm; 861 } 862 if (m) 863 log(LOG_ERR, 864 "rn_delete: Orphaned Mask %p at %p\n", 865 (void *)m, (void *)x); 866 } 867 } 868 /* 869 * We may be holding an active internal node in the tree. 870 */ 871 x = tt + 1; 872 if (t != x) { 873#ifndef RN_DEBUG 874 *t = *x; 875#else 876 b = t->rn_info; 877 *t = *x; 878 t->rn_info = b; 879#endif 880 t->rn_left->rn_parent = t; 881 t->rn_right->rn_parent = t; 882 p = x->rn_parent; 883 if (p->rn_left == x) 884 p->rn_left = t; 885 else 886 p->rn_right = t; 887 } 888out: 889 tt->rn_flags &= ~RNF_ACTIVE; 890 tt[1].rn_flags &= ~RNF_ACTIVE; 891 return (tt); 892} 893 894/* 895 * This is the same as rn_walktree() except for the parameters and the 896 * exit. 897 */ 898static int 899rn_walktree_from(h, a, m, f, w) 900 struct radix_node_head *h; 901 void *a, *m; 902 walktree_f_t *f; 903 void *w; 904{ 905 int error; 906 struct radix_node *base, *next; 907 u_char *xa = (u_char *)a; 908 u_char *xm = (u_char *)m; 909 register struct radix_node *rn, *last = 0 /* shut up gcc */; 910 int stopping = 0; 911 int lastb; 912 913 /* 914 * rn_search_m is sort-of-open-coded here. 915 */ 916 /* printf("about to search\n"); */ 917 for (rn = h->rnh_treetop; rn->rn_bit >= 0; ) { 918 last = rn; 919 /* printf("rn_bit %d, rn_bmask %x, xm[rn_offset] %x\n", 920 rn->rn_bit, rn->rn_bmask, xm[rn->rn_offset]); */ 921 if (!(rn->rn_bmask & xm[rn->rn_offset])) { 922 break; 923 } 924 if (rn->rn_bmask & xa[rn->rn_offset]) { 925 rn = rn->rn_right; 926 } else { 927 rn = rn->rn_left; 928 } 929 } 930 /* printf("done searching\n"); */ 931 932 /* 933 * Two cases: either we stepped off the end of our mask, 934 * in which case last == rn, or we reached a leaf, in which 935 * case we want to start from the last node we looked at. 936 * Either way, last is the node we want to start from. 937 */ 938 rn = last; 939 lastb = rn->rn_bit; 940 941 /* printf("rn %p, lastb %d\n", rn, lastb);*/ 942 943 /* 944 * This gets complicated because we may delete the node 945 * while applying the function f to it, so we need to calculate 946 * the successor node in advance. 947 */ 948 while (rn->rn_bit >= 0) 949 rn = rn->rn_left; 950 951 while (!stopping) { 952 /* printf("node %p (%d)\n", rn, rn->rn_bit); */ 953 base = rn; 954 /* If at right child go back up, otherwise, go right */ 955 while (rn->rn_parent->rn_right == rn 956 && !(rn->rn_flags & RNF_ROOT)) { 957 rn = rn->rn_parent; 958 959 /* if went up beyond last, stop */ 960 if (rn->rn_bit < lastb) { 961 stopping = 1; 962 /* printf("up too far\n"); */ 963 } 964 } 965 966 /* Find the next *leaf* since next node might vanish, too */ 967 for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;) 968 rn = rn->rn_left; 969 next = rn; 970 /* Process leaves */ 971 while ((rn = base) != 0) { 972 base = rn->rn_dupedkey; 973 /* printf("leaf %p\n", rn); */ 974 if (!(rn->rn_flags & RNF_ROOT) 975 && (error = (*f)(rn, w))) 976 return (error); 977 } 978 rn = next; 979 980 if (rn->rn_flags & RNF_ROOT) { 981 /* printf("root, stopping"); */ 982 stopping = 1; 983 } 984 985 } 986 return 0; 987} 988 989static int 990rn_walktree(h, f, w) 991 struct radix_node_head *h; 992 walktree_f_t *f; 993 void *w; 994{ 995 int error; 996 struct radix_node *base, *next; 997 register struct radix_node *rn = h->rnh_treetop; 998 /* 999 * This gets complicated because we may delete the node 1000 * while applying the function f to it, so we need to calculate 1001 * the successor node in advance. 1002 */ 1003 /* First time through node, go left */ 1004 while (rn->rn_bit >= 0) 1005 rn = rn->rn_left; 1006 for (;;) { 1007 base = rn; 1008 /* If at right child go back up, otherwise, go right */ 1009 while (rn->rn_parent->rn_right == rn 1010 && (rn->rn_flags & RNF_ROOT) == 0) 1011 rn = rn->rn_parent; 1012 /* Find the next *leaf* since next node might vanish, too */ 1013 for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;) 1014 rn = rn->rn_left; 1015 next = rn; 1016 /* Process leaves */ 1017 while ((rn = base)) { 1018 base = rn->rn_dupedkey; 1019 if (!(rn->rn_flags & RNF_ROOT) 1020 && (error = (*f)(rn, w))) 1021 return (error); 1022 } 1023 rn = next; 1024 if (rn->rn_flags & RNF_ROOT) 1025 return (0); 1026 } 1027 /* NOTREACHED */ 1028} 1029 1030int 1031rn_inithead(head, off) 1032 void **head; 1033 int off; 1034{ 1035 register struct radix_node_head *rnh; 1036 register struct radix_node *t, *tt, *ttt; 1037 if (*head) 1038 return (1); 1039 R_Zalloc(rnh, struct radix_node_head *, sizeof (*rnh)); 1040 if (rnh == 0) 1041 return (0); 1042#ifdef _KERNEL 1043 RADIX_NODE_HEAD_LOCK_INIT(rnh); 1044#endif 1045 *head = rnh; 1046 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes); 1047 ttt = rnh->rnh_nodes + 2; 1048 t->rn_right = ttt; 1049 t->rn_parent = t; 1050 tt = t->rn_left; 1051 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE; 1052 tt->rn_bit = -1 - off; 1053 *ttt = *tt; 1054 ttt->rn_key = rn_ones; 1055 rnh->rnh_addaddr = rn_addroute; 1056 rnh->rnh_deladdr = rn_delete; 1057 rnh->rnh_matchaddr = rn_match; 1058 rnh->rnh_lookup = rn_lookup; 1059 rnh->rnh_walktree = rn_walktree; 1060 rnh->rnh_walktree_from = rn_walktree_from; 1061 rnh->rnh_treetop = t; 1062 return (1); 1063} 1064 1065void 1066rn_init() 1067{ 1068 char *cp, *cplim; 1069#ifdef _KERNEL 1070 struct domain *dom; 1071 1072 for (dom = domains; dom; dom = dom->dom_next) 1073 if (dom->dom_maxrtkey > max_keylen) 1074 max_keylen = dom->dom_maxrtkey; 1075#endif 1076 if (max_keylen == 0) { 1077 log(LOG_ERR, 1078 "rn_init: radix functions require max_keylen be set\n"); 1079 return; 1080 } 1081 R_Malloc(rn_zeros, char *, 3 * max_keylen); 1082 if (rn_zeros == NULL) 1083 panic("rn_init"); 1084 bzero(rn_zeros, 3 * max_keylen); 1085 rn_ones = cp = rn_zeros + max_keylen; 1086 addmask_key = cplim = rn_ones + max_keylen; 1087 while (cp < cplim) 1088 *cp++ = -1; 1089 if (rn_inithead((void **)(void *)&mask_rnhead, 0) == 0) 1090 panic("rn_init 2"); 1091} 1092