1/* 2 * Copyright 2006, Haiku, Inc. All Rights Reserved. 3 * Distributed under the terms of the MIT License. 4 */ 5 6/* 7 * Copyright (c) 1988, 1989, 1993 8 * The Regents of the University of California. All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35/* 36 * Routines to build and maintain radix trees for routing lookups. 37 */ 38 39#include "radix.h" 40 41#include <KernelExport.h> 42 43#include <stdlib.h> 44#include <string.h> 45 46 47static int rn_walktree_from(struct radix_node_head *h, void *a, void *m, 48 walktree_f_t *f, void *w); 49static int rn_walktree(struct radix_node_head *, walktree_f_t *, void *); 50static struct radix_node *rn_insert(void *, struct radix_node_head *, int *, 51 struct radix_node [2]); 52static struct radix_node *rn_newpair(void *, int, struct radix_node[2]); 53static struct radix_node *rn_search(void *, struct radix_node *); 54static struct radix_node *rn_search_m(void *, struct radix_node *, void *); 55 56static int max_keylen; 57static struct radix_mask *rn_mkfreelist; 58static struct radix_node_head *mask_rnhead; 59/* 60 * Work area -- the following point to 3 buffers of size max_keylen, 61 * allocated in this order in a block of memory malloc'ed by rn_init. 62 */ 63static uint8 *rn_zeros, *rn_ones, *addmask_key; 64 65#define MKFree(m) { (m)->rm_mklist = rn_mkfreelist; rn_mkfreelist = (m);} 66 67#define rn_masktop (mask_rnhead->rnh_treetop) 68 69static int rn_lexobetter(void *m_arg, void *n_arg); 70static struct radix_mask *rn_new_radix_mask(struct radix_node *tt, 71 struct radix_mask *next); 72static int rn_satisfies_leaf(char *trial, struct radix_node *leaf, 73 int skip); 74 75/* 76 * The data structure for the keys is a radix tree with one way 77 * branching removed. The index rn_bit at an internal node n represents a bit 78 * position to be tested. The tree is arranged so that all descendants 79 * of a node n have keys whose bits all agree up to position rn_bit - 1. 80 * (We say the index of n is rn_bit.) 81 * 82 * There is at least one descendant which has a one bit at position rn_bit, 83 * and at least one with a zero there. 84 * 85 * A route is determined by a pair of key and mask. We require that the 86 * bit-wise logical and of the key and mask to be the key. 87 * We define the index of a route to associated with the mask to be 88 * the first bit number in the mask where 0 occurs (with bit number 0 89 * representing the highest order bit). 90 * 91 * We say a mask is normal if every bit is 0, past the index of the mask. 92 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_bit, 93 * and m is a normal mask, then the route applies to every descendant of n. 94 * If the index(m) < rn_bit, this implies the trailing last few bits of k 95 * before bit b are all 0, (and hence consequently true of every descendant 96 * of n), so the route applies to all descendants of the node as well. 97 * 98 * Similar logic shows that a non-normal mask m such that 99 * index(m) <= index(n) could potentially apply to many children of n. 100 * Thus, for each non-host route, we attach its mask to a list at an internal 101 * node as high in the tree as we can go. 102 * 103 * The present version of the code makes use of normal routes in short- 104 * circuiting an explict mask and compare operation when testing whether 105 * a key satisfies a normal route, and also in remembering the unique leaf 106 * that governs a subtree. 107 */ 108 109/* 110 * Most of the functions in this code assume that the key/mask arguments 111 * are sockaddr-like structures, where the first byte is an u_char 112 * indicating the size of the entire structure. 113 * 114 * To make the assumption more explicit, we use the LEN() macro to access 115 * this field. It is safe to pass an expression with side effects 116 * to LEN() as the argument is evaluated only once. 117 */ 118#define LEN(x) (*(const u_char *)(x)) 119 120/* 121 * XXX THIS NEEDS TO BE FIXED 122 * In the code, pointers to keys and masks are passed as either 123 * 'void *' (because callers use to pass pointers of various kinds), or 124 * 'caddr_t' (which is fine for pointer arithmetics, but not very 125 * clean when you dereference it to access data). Furthermore, caddr_t 126 * is really 'char *', while the natural type to operate on keys and 127 * masks would be 'u_char'. This mismatch require a lot of casts and 128 * intermediate variables to adapt types that clutter the code. 129 */ 130 131 132static int /* XXX: arbitrary ordering for non-contiguous masks */ 133rn_lexobetter(void *m_arg, void *n_arg) 134{ 135 register uint8 *mp = m_arg, *np = n_arg, *lim; 136 137 if (LEN(mp) > LEN(np)) 138 return 1; /* not really, but need to check longer one first */ 139 if (LEN(mp) == LEN(np)) { 140 for (lim = mp + LEN(mp); mp < lim;) { 141 if (*mp++ > *np++) 142 return 1; 143 } 144 } 145 return 0; 146} 147 148 149static struct radix_mask * 150rn_new_radix_mask(register struct radix_node *tt, register struct radix_mask *next) 151{ 152 register struct radix_mask *m; 153 154 if (rn_mkfreelist) { 155 m = rn_mkfreelist; 156 rn_mkfreelist = m->rm_mklist; 157 } else 158 m = (struct radix_mask *)malloc(sizeof(struct radix_mask)); 159 if (m == 0) { 160 dprintf("Mask for route not entered\n"); 161 return 0; 162 } 163 memset(m, 0, sizeof *m); 164 m->rm_bit = tt->rn_bit; 165 m->rm_flags = tt->rn_flags; 166 if (tt->rn_flags & RNF_NORMAL) 167 m->rm_leaf = tt; 168 else 169 m->rm_mask = tt->rn_mask; 170 m->rm_mklist = next; 171 tt->rn_mklist = m; 172 return m; 173} 174 175 176/*! 177 Search a node in the tree matching the key. 178*/ 179static struct radix_node * 180rn_search(void *v_arg, struct radix_node *head) 181{ 182 register struct radix_node *x; 183 register caddr_t v; 184 185 for (x = head, v = v_arg; x->rn_bit >= 0;) { 186 if (x->rn_bmask & v[x->rn_offset]) 187 x = x->rn_right; 188 else 189 x = x->rn_left; 190 } 191 return x; 192} 193 194 195/*! 196 Same as above, but with an additional mask. 197 XXX note this function is used only once. 198*/ 199static struct radix_node * 200rn_search_m(void *v_arg, struct radix_node *head, void *m_arg) 201{ 202 register struct radix_node *x; 203 register caddr_t v = v_arg, m = m_arg; 204 205 for (x = head; x->rn_bit >= 0;) { 206 if ((x->rn_bmask & m[x->rn_offset]) 207 && (x->rn_bmask & v[x->rn_offset])) 208 x = x->rn_right; 209 else 210 x = x->rn_left; 211 } 212 return x; 213} 214 215 216static int 217rn_satisfies_leaf(char *trial, register struct radix_node *leaf, int skip) 218{ 219 register char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask; 220 char *cplim; 221 int length = min(LEN(cp), LEN(cp2)); 222 223 if (cp3 == 0) 224 cp3 = rn_ones; 225 else 226 length = min(length, *(u_char *)cp3); 227 cplim = cp + length; cp3 += skip; cp2 += skip; 228 for (cp += skip; cp < cplim; cp++, cp2++, cp3++) 229 if ((*cp ^ *cp2) & *cp3) 230 return 0; 231 return 1; 232} 233 234 235/* 236 * Whenever we add a new leaf to the tree, we also add a parent node, 237 * so we allocate them as an array of two elements: the first one must be 238 * the leaf (see RNTORT() in route.c), the second one is the parent. 239 * This routine initializes the relevant fields of the nodes, so that 240 * the leaf is the left child of the parent node, and both nodes have 241 * (almost) all all fields filled as appropriate. 242 * (XXX some fields are left unset, see the '#if 0' section). 243 * The function returns a pointer to the parent node. 244 */ 245 246static struct radix_node * 247rn_newpair(void *v, int b, struct radix_node nodes[2]) 248{ 249 register struct radix_node *tt = nodes, *t = tt + 1; 250 t->rn_bit = b; 251 t->rn_bmask = 0x80 >> (b & 7); 252 t->rn_left = tt; 253 t->rn_offset = b >> 3; 254 255#if 0 /* XXX perhaps we should fill these fields as well. */ 256 t->rn_parent = t->rn_right = NULL; 257 258 tt->rn_mask = NULL; 259 tt->rn_dupedkey = NULL; 260 tt->rn_bmask = 0; 261#endif 262 tt->rn_bit = -1; 263 tt->rn_key = (caddr_t)v; 264 tt->rn_parent = t; 265 tt->rn_flags = t->rn_flags = RNF_ACTIVE; 266 tt->rn_mklist = t->rn_mklist = 0; 267 return t; 268} 269 270 271static struct radix_node * 272rn_insert(void *v_arg, struct radix_node_head *head, int *dupentry, 273 struct radix_node nodes[2]) 274{ 275 uint8 *v = v_arg; 276 struct radix_node *top = head->rnh_treetop; 277 int head_off = top->rn_offset, vlen = (int)LEN(v); 278 register struct radix_node *t = rn_search(v_arg, top); 279 register uint8 *cp = v + head_off; 280 register int b; 281 struct radix_node *tt; 282 /* 283 * Find first bit at which v and t->rn_key differ 284 */ 285 { 286 register uint8 *cp2 = t->rn_key + head_off; 287 register int cmp_res; 288 uint8 *cplim = v + vlen; 289 290 while (cp < cplim) { 291 if (*cp2++ != *cp++) 292 goto on1; 293 } 294 *dupentry = 1; 295 return t; 296 on1: 297 *dupentry = 0; 298 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff; 299 for (b = (cp - v) << 3; cmp_res; b--) { 300 cmp_res >>= 1; 301 } 302 } 303 { 304 register struct radix_node *p, *x = top; 305 cp = v; 306 do { 307 p = x; 308 if (cp[x->rn_offset] & x->rn_bmask) 309 x = x->rn_right; 310 else 311 x = x->rn_left; 312 } while (b > (unsigned) x->rn_bit); 313 /* x->rn_bit < b && x->rn_bit >= 0 */ 314 t = rn_newpair(v_arg, b, nodes); 315 tt = t->rn_left; 316 if ((cp[p->rn_offset] & p->rn_bmask) == 0) 317 p->rn_left = t; 318 else 319 p->rn_right = t; 320 x->rn_parent = t; 321 t->rn_parent = p; /* frees x, p as temp vars below */ 322 if ((cp[t->rn_offset] & t->rn_bmask) == 0) { 323 t->rn_right = x; 324 } else { 325 t->rn_right = tt; 326 t->rn_left = x; 327 } 328 } 329 return tt; 330} 331 332 333/*! 334 This is the same as rn_walktree() except for the parameters and the 335 exit. 336*/ 337static int 338rn_walktree_from(struct radix_node_head *h, void *a, void *m, walktree_f_t *f, void *w) 339{ 340 int error; 341 struct radix_node *base, *next; 342 u_char *xa = (u_char *)a; 343 u_char *xm = (u_char *)m; 344 register struct radix_node *rn, *last = 0 /* shut up gcc */; 345 int stopping = 0; 346 int lastb; 347 348 /* 349 * rn_search_m is sort-of-open-coded here. We cannot use the 350 * function because we need to keep track of the last node seen. 351 */ 352 /* printf("about to search\n"); */ 353 for (rn = h->rnh_treetop; rn->rn_bit >= 0; ) { 354 last = rn; 355 /* printf("rn_bit %d, rn_bmask %x, xm[rn_offset] %x\n", 356 rn->rn_bit, rn->rn_bmask, xm[rn->rn_offset]); */ 357 if (!(rn->rn_bmask & xm[rn->rn_offset])) { 358 break; 359 } 360 if (rn->rn_bmask & xa[rn->rn_offset]) { 361 rn = rn->rn_right; 362 } else { 363 rn = rn->rn_left; 364 } 365 } 366 /* printf("done searching\n"); */ 367 368 /* 369 * Two cases: either we stepped off the end of our mask, 370 * in which case last == rn, or we reached a leaf, in which 371 * case we want to start from the last node we looked at. 372 * Either way, last is the node we want to start from. 373 */ 374 rn = last; 375 lastb = rn->rn_bit; 376 377 /* printf("rn %p, lastb %d\n", rn, lastb);*/ 378 379 /* 380 * This gets complicated because we may delete the node 381 * while applying the function f to it, so we need to calculate 382 * the successor node in advance. 383 */ 384 while (rn->rn_bit >= 0) { 385 rn = rn->rn_left; 386 } 387 388 while (!stopping) { 389 /* printf("node %p (%d)\n", rn, rn->rn_bit); */ 390 base = rn; 391 /* If at right child go back up, otherwise, go right */ 392 while (rn->rn_parent->rn_right == rn 393 && !(rn->rn_flags & RNF_ROOT)) { 394 rn = rn->rn_parent; 395 396 /* if went up beyond last, stop */ 397 if (rn->rn_bit <= lastb) { 398 stopping = 1; 399 /* printf("up too far\n"); */ 400 /* 401 * XXX we should jump to the 'Process leaves' 402 * part, because the values of 'rn' and 'next' 403 * we compute will not be used. Not a big deal 404 * because this loop will terminate, but it is 405 * inefficient and hard to understand! 406 */ 407 } 408 } 409 410 /* 411 * At the top of the tree, no need to traverse the right 412 * half, prevent the traversal of the entire tree in the 413 * case of default route. 414 */ 415 if (rn->rn_parent->rn_flags & RNF_ROOT) 416 stopping = 1; 417 418 /* Find the next *leaf* since next node might vanish, too */ 419 for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;) 420 rn = rn->rn_left; 421 next = rn; 422 /* Process leaves */ 423 while ((rn = base) != 0) { 424 base = rn->rn_dupedkey; 425 /* printf("leaf %p\n", rn); */ 426 if (!(rn->rn_flags & RNF_ROOT) 427 && (error = (*f)(rn, w))) 428 return (error); 429 } 430 rn = next; 431 432 if (rn->rn_flags & RNF_ROOT) { 433 /* printf("root, stopping"); */ 434 stopping = 1; 435 } 436 } 437 return 0; 438} 439 440 441static int 442rn_walktree(struct radix_node_head *h, walktree_f_t *f, void *w) 443{ 444 int error; 445 struct radix_node *base, *next; 446 register struct radix_node *rn = h->rnh_treetop; 447 /* 448 * This gets complicated because we may delete the node 449 * while applying the function f to it, so we need to calculate 450 * the successor node in advance. 451 */ 452 /* First time through node, go left */ 453 while (rn->rn_bit >= 0) { 454 rn = rn->rn_left; 455 } 456 for (;;) { 457 base = rn; 458 /* If at right child go back up, otherwise, go right */ 459 while (rn->rn_parent->rn_right == rn 460 && (rn->rn_flags & RNF_ROOT) == 0) { 461 rn = rn->rn_parent; 462 } 463 /* Find the next *leaf* since next node might vanish, too */ 464 for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;) { 465 rn = rn->rn_left; 466 } 467 next = rn; 468 /* Process leaves */ 469 while ((rn = base)) { 470 base = rn->rn_dupedkey; 471 if (!(rn->rn_flags & RNF_ROOT) 472 && (error = (*f)(rn, w))) 473 return error; 474 } 475 rn = next; 476 if (rn->rn_flags & RNF_ROOT) 477 return 0; 478 } 479 /* NOTREACHED */ 480} 481 482 483// #pragma mark - public API 484 485 486struct radix_node * 487rn_lookup(void *v_arg, void *m_arg, struct radix_node_head *head) 488{ 489 register struct radix_node *x; 490 uint8 *netmask = NULL; 491 492 if (m_arg) { 493 x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_offset); 494 if (x == 0) 495 return 0; 496 netmask = x->rn_key; 497 } 498 x = rn_match(v_arg, head); 499 if (x && netmask) { 500 while (x && x->rn_mask != netmask) 501 x = x->rn_dupedkey; 502 } 503 return x; 504} 505 506 507struct radix_node * 508rn_match(void *v_arg, struct radix_node_head *head) 509{ 510 caddr_t v = v_arg; 511 register struct radix_node *t = head->rnh_treetop, *x; 512 register caddr_t cp = v, cp2; 513 caddr_t cplim; 514 struct radix_node *saved_t, *top = t; 515 int off = t->rn_offset, vlen = LEN(cp), matched_off; 516 register int test, b, rn_bit; 517 518 /* 519 * Open code rn_search(v, top) to avoid overhead of extra 520 * subroutine call. 521 */ 522 for (; t->rn_bit >= 0; ) { 523 if (t->rn_bmask & cp[t->rn_offset]) 524 t = t->rn_right; 525 else 526 t = t->rn_left; 527 } 528 /* 529 * See if we match exactly as a host destination 530 * or at least learn how many bits match, for normal mask finesse. 531 * 532 * It doesn't hurt us to limit how many bytes to check 533 * to the length of the mask, since if it matches we had a genuine 534 * match and the leaf we have is the most specific one anyway; 535 * if it didn't match with a shorter length it would fail 536 * with a long one. This wins big for class B&C netmasks which 537 * are probably the most common case... 538 */ 539 if (t->rn_mask) 540 vlen = *(u_char *)t->rn_mask; 541 cp += off; cp2 = t->rn_key + off; cplim = v + vlen; 542 for (; cp < cplim; cp++, cp2++) { 543 if (*cp != *cp2) 544 goto on1; 545 } 546 /* 547 * This extra grot is in case we are explicitly asked 548 * to look up the default. Ugh! 549 * 550 * Never return the root node itself, it seems to cause a 551 * lot of confusion. 552 */ 553 if (t->rn_flags & RNF_ROOT) 554 t = t->rn_dupedkey; 555 return t; 556on1: 557 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */ 558 for (b = 7; (test >>= 1) > 0;) 559 b--; 560 matched_off = cp - v; 561 b += matched_off << 3; 562 rn_bit = -1 - b; 563 /* 564 * If there is a host route in a duped-key chain, it will be first. 565 */ 566 if ((saved_t = t)->rn_mask == 0) 567 t = t->rn_dupedkey; 568 for (; t; t = t->rn_dupedkey) { 569 /* 570 * Even if we don't match exactly as a host, 571 * we may match if the leaf we wound up at is 572 * a route to a net. 573 */ 574 if (t->rn_flags & RNF_NORMAL) { 575 if (rn_bit <= t->rn_bit) 576 return t; 577 } else if (rn_satisfies_leaf(v, t, matched_off)) 578 return t; 579 } 580 581 t = saved_t; 582 /* start searching up the tree */ 583 do { 584 register struct radix_mask *m; 585 t = t->rn_parent; 586 m = t->rn_mklist; 587 /* 588 * If non-contiguous masks ever become important 589 * we can restore the masking and open coding of 590 * the search and satisfaction test and put the 591 * calculation of "off" back before the "do". 592 */ 593 while (m) { 594 if (m->rm_flags & RNF_NORMAL) { 595 if (rn_bit <= m->rm_bit) 596 return (m->rm_leaf); 597 } else { 598 off = min(t->rn_offset, matched_off); 599 x = rn_search_m(v, t, m->rm_mask); 600 while (x && x->rn_mask != m->rm_mask) 601 x = x->rn_dupedkey; 602 if (x && rn_satisfies_leaf(v, x, off)) 603 return x; 604 } 605 m = m->rm_mklist; 606 } 607 } while (t != top); 608 609 return 0; 610} 611 612 613struct radix_node * 614rn_addmask(void *n_arg, int search, int skip) 615{ 616 uint8 *netmask = (uint8 *)n_arg; 617 register struct radix_node *x; 618 register uint8 *cp, *cplim; 619 register int b = 0, mlen, j; 620 int maskduplicated, m0, isnormal; 621 struct radix_node *saved_x; 622 static int last_zeroed = 0; 623 624 if ((mlen = LEN(netmask)) > max_keylen) 625 mlen = max_keylen; 626 if (skip == 0) 627 skip = 1; 628 if (mlen <= skip) 629 return mask_rnhead->rnh_nodes; 630 if (skip > 1) 631 memcpy(addmask_key + 1, rn_ones + 1, skip - 1); 632 if ((m0 = mlen) > skip) 633 memcpy(addmask_key + skip, netmask + skip, mlen - skip); 634 /* 635 * Trim trailing zeroes. 636 */ 637 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;) 638 cp--; 639 mlen = cp - addmask_key; 640 if (mlen <= skip) { 641 if (m0 >= last_zeroed) 642 last_zeroed = mlen; 643 return (mask_rnhead->rnh_nodes); 644 } 645 if (m0 < last_zeroed) 646 memset(addmask_key + m0, 0, last_zeroed - m0); 647 *addmask_key = last_zeroed = mlen; 648 x = rn_search(addmask_key, rn_masktop); 649 if (memcmp(addmask_key, x->rn_key, mlen) != 0) 650 x = 0; 651 if (x || search) 652 return x; 653 x = (struct radix_node *)calloc(1, max_keylen + 2 * sizeof(*x)); 654 if ((saved_x = x) == 0) 655 return 0; 656 netmask = cp = (caddr_t)(x + 2); 657 memcpy(cp, addmask_key, mlen); 658 x = rn_insert(cp, mask_rnhead, &maskduplicated, x); 659 if (maskduplicated) { 660 dprintf("rn_addmask: mask impossibly already in tree\n"); 661 free(saved_x); 662 return x; 663 } 664 /* 665 * Calculate index of mask, and check for normalcy. 666 * First find the first byte with a 0 bit, then if there are 667 * more bits left (remember we already trimmed the trailing 0's), 668 * the pattern must be one of those in normal_chars[], or we have 669 * a non-contiguous mask. 670 */ 671 cplim = netmask + mlen; 672 isnormal = 1; 673 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;) { 674 cp++; 675 } 676 if (cp != cplim) { 677 static char normal_chars[] = { 678 0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff}; 679 680 for (j = 0x80; (j & *cp) != 0; j >>= 1) 681 b++; 682 if (*cp != normal_chars[b] || cp != (cplim - 1)) 683 isnormal = 0; 684 } 685 b += (cp - netmask) << 3; 686 x->rn_bit = -1 - b; 687 if (isnormal) 688 x->rn_flags |= RNF_NORMAL; 689 return x; 690} 691 692 693struct radix_node * 694rn_addroute(void *v_arg, void *n_arg, struct radix_node_head *head, 695 struct radix_node treenodes[2]) 696{ 697 uint8 *v = (uint8 *)v_arg, *netmask = (uint8 *)n_arg; 698 register struct radix_node *t, *x = 0, *tt; 699 struct radix_node *saved_tt, *top = head->rnh_treetop; 700 short b = 0, b_leaf = 0; 701 int keyduplicated; 702 uint8 *mmask; 703 struct radix_mask *m, **mp; 704 705 /* 706 * In dealing with non-contiguous masks, there may be 707 * many different routes which have the same mask. 708 * We will find it useful to have a unique pointer to 709 * the mask to speed avoiding duplicate references at 710 * nodes and possibly save time in calculating indices. 711 */ 712 if (netmask) { 713 if ((x = rn_addmask(netmask, 0, top->rn_offset)) == 0) 714 return (0); 715 b_leaf = x->rn_bit; 716 b = -1 - x->rn_bit; 717 netmask = x->rn_key; 718 } 719 /* 720 * Deal with duplicated keys: attach node to previous instance 721 */ 722 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes); 723 if (keyduplicated) { 724 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) { 725 if (tt->rn_mask == netmask) 726 return (0); 727 if (netmask == 0 || 728 (tt->rn_mask && 729 ((b_leaf < tt->rn_bit) /* index(netmask) > node */ 730 || rn_refines(netmask, tt->rn_mask) 731 || rn_lexobetter(netmask, tt->rn_mask)))) 732 break; 733 } 734 /* 735 * If the mask is not duplicated, we wouldn't 736 * find it among possible duplicate key entries 737 * anyway, so the above test doesn't hurt. 738 * 739 * We sort the masks for a duplicated key the same way as 740 * in a masklist -- most specific to least specific. 741 * This may require the unfortunate nuisance of relocating 742 * the head of the list. 743 * 744 * We also reverse, or doubly link the list through the 745 * parent pointer. 746 */ 747 if (tt == saved_tt) { 748 struct radix_node *xx = x; 749 /* link in at head of list */ 750 (tt = treenodes)->rn_dupedkey = t; 751 tt->rn_flags = t->rn_flags; 752 tt->rn_parent = x = t->rn_parent; 753 t->rn_parent = tt; /* parent */ 754 if (x->rn_left == t) 755 x->rn_left = tt; 756 else 757 x->rn_right = tt; 758 saved_tt = tt; x = xx; 759 } else { 760 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey; 761 t->rn_dupedkey = tt; 762 tt->rn_parent = t; /* parent */ 763 if (tt->rn_dupedkey) /* parent */ 764 tt->rn_dupedkey->rn_parent = tt; /* parent */ 765 } 766 tt->rn_key = (caddr_t) v; 767 tt->rn_bit = -1; 768 tt->rn_flags = RNF_ACTIVE; 769 } 770 /* 771 * Put mask in tree. 772 */ 773 if (netmask) { 774 tt->rn_mask = netmask; 775 tt->rn_bit = x->rn_bit; 776 tt->rn_flags |= x->rn_flags & RNF_NORMAL; 777 } 778 t = saved_tt->rn_parent; 779 if (keyduplicated) 780 goto on2; 781 b_leaf = -1 - t->rn_bit; 782 if (t->rn_right == saved_tt) 783 x = t->rn_left; 784 else 785 x = t->rn_right; 786 /* Promote general routes from below */ 787 if (x->rn_bit < 0) { 788 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey) 789 if (x->rn_mask && (x->rn_bit >= b_leaf) && x->rn_mklist == 0) { 790 *mp = m = rn_new_radix_mask(x, 0); 791 if (m) 792 mp = &m->rm_mklist; 793 } 794 } else if (x->rn_mklist) { 795 /* 796 * Skip over masks whose index is > that of new node 797 */ 798 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 799 if (m->rm_bit >= b_leaf) 800 break; 801 t->rn_mklist = m; *mp = 0; 802 } 803on2: 804 /* Add new route to highest possible ancestor's list */ 805 if ((netmask == 0) || (b > t->rn_bit )) 806 return tt; /* can't lift at all */ 807 b_leaf = tt->rn_bit; 808 do { 809 x = t; 810 t = t->rn_parent; 811 } while (b <= t->rn_bit && x != top); 812 /* 813 * Search through routes associated with node to 814 * insert new route according to index. 815 * Need same criteria as when sorting dupedkeys to avoid 816 * double loop on deletion. 817 */ 818 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) { 819 if (m->rm_bit < b_leaf) 820 continue; 821 if (m->rm_bit > b_leaf) 822 break; 823 if (m->rm_flags & RNF_NORMAL) { 824 mmask = m->rm_leaf->rn_mask; 825 if (tt->rn_flags & RNF_NORMAL) { 826 dprintf("Non-unique normal route, mask not entered\n"); 827 return tt; 828 } 829 } else 830 mmask = m->rm_mask; 831 if (mmask == netmask) { 832 m->rm_refs++; 833 tt->rn_mklist = m; 834 return tt; 835 } 836 if (rn_refines(netmask, mmask) 837 || rn_lexobetter(netmask, mmask)) 838 break; 839 } 840 *mp = rn_new_radix_mask(tt, *mp); 841 return tt; 842} 843 844 845struct radix_node * 846rn_delete(void *v_arg, void *netmask_arg, struct radix_node_head *head) 847{ 848 register struct radix_node *t, *p, *x, *tt; 849 struct radix_mask *m, *saved_m, **mp; 850 struct radix_node *dupedkey, *saved_tt, *top; 851 uint8 *v, *netmask; 852 int b, head_off, vlen; 853 854 v = v_arg; 855 netmask = netmask_arg; 856 x = head->rnh_treetop; 857 tt = rn_search(v, x); 858 head_off = x->rn_offset; 859 vlen = LEN(v); 860 saved_tt = tt; 861 top = x; 862 if (tt == 0 863 || memcmp(v + head_off, tt->rn_key + head_off, vlen - head_off)) 864 return 0; 865 /* 866 * Delete our route from mask lists. 867 */ 868 if (netmask) { 869 if ((x = rn_addmask(netmask, 1, head_off)) == 0) 870 return 0; 871 netmask = x->rn_key; 872 while (tt->rn_mask != netmask) 873 if ((tt = tt->rn_dupedkey) == 0) 874 return 0; 875 } 876 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0) 877 goto on1; 878 if (tt->rn_flags & RNF_NORMAL) { 879 if (m->rm_leaf != tt || m->rm_refs > 0) { 880 dprintf("rn_delete: inconsistent annotation\n"); 881 return 0; /* dangling ref could cause disaster */ 882 } 883 } else { 884 if (m->rm_mask != tt->rn_mask) { 885 dprintf("rn_delete: inconsistent annotation\n"); 886 goto on1; 887 } 888 if (--m->rm_refs >= 0) 889 goto on1; 890 } 891 b = -1 - tt->rn_bit; 892 t = saved_tt->rn_parent; 893 if (b > t->rn_bit) 894 goto on1; /* Wasn't lifted at all */ 895 do { 896 x = t; 897 t = t->rn_parent; 898 } while (b <= t->rn_bit && x != top); 899 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 900 if (m == saved_m) { 901 *mp = m->rm_mklist; 902 MKFree(m); 903 break; 904 } 905 if (m == 0) { 906 dprintf("rn_delete: couldn't find our annotation\n"); 907 if (tt->rn_flags & RNF_NORMAL) 908 return 0; /* Dangling ref to us */ 909 } 910on1: 911 /* 912 * Eliminate us from tree 913 */ 914 if (tt->rn_flags & RNF_ROOT) 915 return 0; 916 t = tt->rn_parent; 917 dupedkey = saved_tt->rn_dupedkey; 918 if (dupedkey) { 919 /* 920 * Here, tt is the deletion target and 921 * saved_tt is the head of the dupekey chain. 922 */ 923 if (tt == saved_tt) { 924 /* remove from head of chain */ 925 x = dupedkey; x->rn_parent = t; 926 if (t->rn_left == tt) 927 t->rn_left = x; 928 else 929 t->rn_right = x; 930 } else { 931 /* find node in front of tt on the chain */ 932 for (x = p = saved_tt; p && p->rn_dupedkey != tt;) 933 p = p->rn_dupedkey; 934 if (p) { 935 p->rn_dupedkey = tt->rn_dupedkey; 936 if (tt->rn_dupedkey) /* parent */ 937 tt->rn_dupedkey->rn_parent = p; 938 /* parent */ 939 } else 940 dprintf("rn_delete: couldn't find us\n"); 941 } 942 t = tt + 1; 943 if (t->rn_flags & RNF_ACTIVE) { 944 *++x = *t; 945 p = t->rn_parent; 946 if (p->rn_left == t) 947 p->rn_left = x; 948 else 949 p->rn_right = x; 950 x->rn_left->rn_parent = x; 951 x->rn_right->rn_parent = x; 952 } 953 goto out; 954 } 955 if (t->rn_left == tt) 956 x = t->rn_right; 957 else 958 x = t->rn_left; 959 p = t->rn_parent; 960 if (p->rn_right == t) 961 p->rn_right = x; 962 else 963 p->rn_left = x; 964 x->rn_parent = p; 965 /* 966 * Demote routes attached to us. 967 */ 968 if (t->rn_mklist) { 969 if (x->rn_bit >= 0) { 970 for (mp = &x->rn_mklist; (m = *mp);) 971 mp = &m->rm_mklist; 972 *mp = t->rn_mklist; 973 } else { 974 /* If there are any key,mask pairs in a sibling 975 duped-key chain, some subset will appear sorted 976 in the same order attached to our mklist */ 977 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey) { 978 if (m == x->rn_mklist) { 979 struct radix_mask *mm = m->rm_mklist; 980 x->rn_mklist = 0; 981 if (--(m->rm_refs) < 0) 982 MKFree(m); 983 m = mm; 984 } 985 } 986 if (m) { 987 dprintf("rn_delete: Orphaned Mask %p at %p\n", 988 (void *)m, (void *)x); 989 } 990 } 991 } 992 /* 993 * We may be holding an active internal node in the tree. 994 */ 995 x = tt + 1; 996 if (t != x) { 997 *t = *x; 998 t->rn_left->rn_parent = t; 999 t->rn_right->rn_parent = t; 1000 p = x->rn_parent; 1001 if (p->rn_left == x) 1002 p->rn_left = t; 1003 else 1004 p->rn_right = t; 1005 } 1006out: 1007 tt->rn_flags &= ~RNF_ACTIVE; 1008 tt[1].rn_flags &= ~RNF_ACTIVE; 1009 return tt; 1010} 1011 1012 1013int 1014rn_refines(void *m_arg, void *n_arg) 1015{ 1016 register caddr_t m = m_arg, n = n_arg; 1017 register caddr_t lim, lim2 = lim = n + LEN(n); 1018 int longer = LEN(n++) - (int)LEN(m++); 1019 int masks_are_equal = 1; 1020 1021 if (longer > 0) 1022 lim -= longer; 1023 while (n < lim) { 1024 if (*n & ~(*m)) 1025 return 0; 1026 if (*n++ != *m++) 1027 masks_are_equal = 0; 1028 } 1029 1030 while (n < lim2) { 1031 if (*n++) 1032 return 0; 1033 } 1034 1035 if (masks_are_equal && (longer < 0)) { 1036 for (lim2 = m - longer; m < lim2; ) { 1037 if (*m++) 1038 return 1; 1039 } 1040 } 1041 1042 return !masks_are_equal; 1043} 1044 1045 1046/*! 1047 Allocate and initialize an empty tree. This has 3 nodes, which are 1048 part of the radix_node_head (in the order <left,root,right>) and are 1049 marked RNF_ROOT so they cannot be freed. 1050 The leaves have all-zero and all-one keys, with significant 1051 bits starting at 'off'. 1052 Return 1 on success, 0 on error. 1053*/ 1054int 1055rn_inithead(void **head, int off) 1056{ 1057 register struct radix_node_head *rnh; 1058 register struct radix_node *t, *tt, *ttt; 1059 if (*head) 1060 return 1; 1061 rnh = (struct radix_node_head *)calloc(1, sizeof(*rnh)); 1062 if (rnh == NULL) 1063 return 0; 1064 1065 *head = rnh; 1066 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes); 1067 ttt = rnh->rnh_nodes + 2; 1068 t->rn_right = ttt; 1069 t->rn_parent = t; 1070 tt = t->rn_left; /* ... which in turn is rnh->rnh_nodes */ 1071 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE; 1072 tt->rn_bit = -1 - off; 1073 *ttt = *tt; 1074 ttt->rn_key = rn_ones; 1075 rnh->rnh_addaddr = rn_addroute; 1076 rnh->rnh_deladdr = rn_delete; 1077 rnh->rnh_matchaddr = rn_match; 1078 rnh->rnh_lookup = rn_lookup; 1079 rnh->rnh_walktree = rn_walktree; 1080 rnh->rnh_walktree_from = rn_walktree_from; 1081 rnh->rnh_treetop = t; 1082 return 1; 1083} 1084 1085 1086void 1087rn_init() 1088{ 1089 char *cp, *cplim; 1090#ifdef _KERNEL 1091 struct domain *dom; 1092 1093 for (dom = domains; dom; dom = dom->dom_next) 1094 if (dom->dom_maxrtkey > max_keylen) 1095 max_keylen = dom->dom_maxrtkey; 1096#endif 1097 if (max_keylen == 0) { 1098 dprintf("rn_init: radix functions require max_keylen be set\n"); 1099 return; 1100 } 1101 rn_zeros = (char *)malloc(3 * max_keylen); 1102 if (rn_zeros == NULL) 1103 panic("rn_init"); 1104 memset(rn_zeros, 0, 3 * max_keylen); 1105 rn_ones = cp = rn_zeros + max_keylen; 1106 addmask_key = cplim = rn_ones + max_keylen; 1107 while (cp < cplim) 1108 *cp++ = -1; 1109 if (rn_inithead((void **)(void *)&mask_rnhead, 0) == 0) 1110 panic("rn_init 2"); 1111} 1112