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sys/net/radix.c
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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: releng/8.0/sys/net/radix.c 186176 2008-12-16 11:01:36Z kmacy $ 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/rwlock.h> 42 #include <sys/systm.h> 43 #include <sys/malloc.h> 44 #include <sys/domain.h> 45 #else 46 #include <stdlib.h> 47 #endif 48 #include <sys/syslog.h> 49 #include <net/radix.h> 50 #endif 51 52 #include "opt_mpath.h" 53 54 #ifdef RADIX_MPATH 55 #include <net/radix_mpath.h> 56 #endif 57 58 59 static int rn_walktree_from(struct radix_node_head *h, void *a, void *m, 60 walktree_f_t *f, void *w); 61 static int rn_walktree(struct radix_node_head *, walktree_f_t *, void *); 62 static struct radix_node 63 *rn_insert(void *, struct radix_node_head *, int *, 64 struct radix_node [2]), 65 *rn_newpair(void *, int, struct radix_node[2]), 66 *rn_search(void *, struct radix_node *), 67 *rn_search_m(void *, struct radix_node *, void *); 68 69 static int max_keylen; 70 static struct radix_mask *rn_mkfreelist; 71 static struct radix_node_head *mask_rnhead; 72 /* 73 * Work area -- the following point to 3 buffers of size max_keylen, 74 * allocated in this order in a block of memory malloc'ed by rn_init. 75 */ 76 static char *rn_zeros, *rn_ones, *addmask_key; 77 78 #define MKGet(m) { \ 79 if (rn_mkfreelist) { \ 80 m = rn_mkfreelist; \ 81 rn_mkfreelist = (m)->rm_mklist; \ 82 } else \ 83 R_Malloc(m, struct radix_mask *, sizeof (struct radix_mask)); } 84 85 #define MKFree(m) { (m)->rm_mklist = rn_mkfreelist; rn_mkfreelist = (m);} 86 87 #define rn_masktop (mask_rnhead->rnh_treetop) 88 89 static int rn_lexobetter(void *m_arg, void *n_arg); 90 static struct radix_mask * 91 rn_new_radix_mask(struct radix_node *tt, 92 struct radix_mask *next); 93 static int rn_satisfies_leaf(char *trial, struct radix_node *leaf, 94 int skip); 95 96 /* 97 * The data structure for the keys is a radix tree with one way 98 * branching removed. The index rn_bit at an internal node n represents a bit 99 * position to be tested. The tree is arranged so that all descendants 100 * of a node n have keys whose bits all agree up to position rn_bit - 1. 101 * (We say the index of n is rn_bit.) 102 * 103 * There is at least one descendant which has a one bit at position rn_bit, 104 * and at least one with a zero there. 105 * 106 * A route is determined by a pair of key and mask. We require that the 107 * bit-wise logical and of the key and mask to be the key. 108 * We define the index of a route to associated with the mask to be 109 * the first bit number in the mask where 0 occurs (with bit number 0 110 * representing the highest order bit). 111 * 112 * We say a mask is normal if every bit is 0, past the index of the mask. 113 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_bit, 114 * and m is a normal mask, then the route applies to every descendant of n. 115 * If the index(m) < rn_bit, this implies the trailing last few bits of k 116 * before bit b are all 0, (and hence consequently true of every descendant 117 * of n), so the route applies to all descendants of the node as well. 118 * 119 * Similar logic shows that a non-normal mask m such that 120 * index(m) <= index(n) could potentially apply to many children of n. 121 * Thus, for each non-host route, we attach its mask to a list at an internal 122 * node as high in the tree as we can go. 123 * 124 * The present version of the code makes use of normal routes in short- 125 * circuiting an explict mask and compare operation when testing whether 126 * a key satisfies a normal route, and also in remembering the unique leaf 127 * that governs a subtree. 128 */ 129 130 /* 131 * Most of the functions in this code assume that the key/mask arguments 132 * are sockaddr-like structures, where the first byte is an u_char 133 * indicating the size of the entire structure. 134 * 135 * To make the assumption more explicit, we use the LEN() macro to access 136 * this field. It is safe to pass an expression with side effects 137 * to LEN() as the argument is evaluated only once. 138 */ 139 #define LEN(x) (*(const u_char *)(x)) 140 141 /* 142 * XXX THIS NEEDS TO BE FIXED 143 * In the code, pointers to keys and masks are passed as either 144 * 'void *' (because callers use to pass pointers of various kinds), or 145 * 'caddr_t' (which is fine for pointer arithmetics, but not very 146 * clean when you dereference it to access data). Furthermore, caddr_t 147 * is really 'char *', while the natural type to operate on keys and 148 * masks would be 'u_char'. This mismatch require a lot of casts and 149 * intermediate variables to adapt types that clutter the code. 150 */ 151 152 /* 153 * Search a node in the tree matching the key. 154 */ 155 static struct radix_node * 156 rn_search(v_arg, head) 157 void *v_arg; 158 struct radix_node *head; 159 { 160 register struct radix_node *x; 161 register caddr_t v; 162 163 for (x = head, v = v_arg; x->rn_bit >= 0;) { 164 if (x->rn_bmask & v[x->rn_offset]) 165 x = x->rn_right; 166 else 167 x = x->rn_left; 168 } 169 return (x); 170 } 171 172 /* 173 * Same as above, but with an additional mask. 174 * XXX note this function is used only once. 175 */ 176 static struct radix_node * 177 rn_search_m(v_arg, head, m_arg) 178 struct radix_node *head; 179 void *v_arg, *m_arg; 180 { 181 register struct radix_node *x; 182 register caddr_t v = v_arg, m = m_arg; 183 184 for (x = head; x->rn_bit >= 0;) { 185 if ((x->rn_bmask & m[x->rn_offset]) && 186 (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 int 195 rn_refines(m_arg, n_arg) 196 void *m_arg, *n_arg; 197 { 198 register caddr_t m = m_arg, n = n_arg; 199 register caddr_t lim, lim2 = lim = n + LEN(n); 200 int longer = LEN(n++) - (int)LEN(m++); 201 int masks_are_equal = 1; 202 203 if (longer > 0) 204 lim -= longer; 205 while (n < lim) { 206 if (*n & ~(*m)) 207 return 0; 208 if (*n++ != *m++) 209 masks_are_equal = 0; 210 } 211 while (n < lim2) 212 if (*n++) 213 return 0; 214 if (masks_are_equal && (longer < 0)) 215 for (lim2 = m - longer; m < lim2; ) 216 if (*m++) 217 return 1; 218 return (!masks_are_equal); 219 } 220 221 struct radix_node * 222 rn_lookup(v_arg, m_arg, head) 223 void *v_arg, *m_arg; 224 struct radix_node_head *head; 225 { 226 register struct radix_node *x; 227 caddr_t netmask = 0; 228 229 if (m_arg) { 230 x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_offset); 231 if (x == 0) 232 return (0); 233 netmask = x->rn_key; 234 } 235 x = rn_match(v_arg, head); 236 if (x && netmask) { 237 while (x && x->rn_mask != netmask) 238 x = x->rn_dupedkey; 239 } 240 return x; 241 } 242 243 static int 244 rn_satisfies_leaf(trial, leaf, skip) 245 char *trial; 246 register struct radix_node *leaf; 247 int skip; 248 { 249 register char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask; 250 char *cplim; 251 int length = min(LEN(cp), LEN(cp2)); 252 253 if (cp3 == 0) 254 cp3 = rn_ones; 255 else 256 length = min(length, *(u_char *)cp3); 257 cplim = cp + length; cp3 += skip; cp2 += skip; 258 for (cp += skip; cp < cplim; cp++, cp2++, cp3++) 259 if ((*cp ^ *cp2) & *cp3) 260 return 0; 261 return 1; 262 } 263 264 struct radix_node * 265 rn_match(v_arg, head) 266 void *v_arg; 267 struct radix_node_head *head; 268 { 269 caddr_t v = v_arg; 270 register struct radix_node *t = head->rnh_treetop, *x; 271 register caddr_t cp = v, cp2; 272 caddr_t cplim; 273 struct radix_node *saved_t, *top = t; 274 int off = t->rn_offset, vlen = LEN(cp), matched_off; 275 register int test, b, rn_bit; 276 277 /* 278 * Open code rn_search(v, top) to avoid overhead of extra 279 * subroutine call. 280 */ 281 for (; t->rn_bit >= 0; ) { 282 if (t->rn_bmask & cp[t->rn_offset]) 283 t = t->rn_right; 284 else 285 t = t->rn_left; 286 } 287 /* 288 * See if we match exactly as a host destination 289 * or at least learn how many bits match, for normal mask finesse. 290 * 291 * It doesn't hurt us to limit how many bytes to check 292 * to the length of the mask, since if it matches we had a genuine 293 * match and the leaf we have is the most specific one anyway; 294 * if it didn't match with a shorter length it would fail 295 * with a long one. This wins big for class B&C netmasks which 296 * are probably the most common case... 297 */ 298 if (t->rn_mask) 299 vlen = *(u_char *)t->rn_mask; 300 cp += off; cp2 = t->rn_key + off; cplim = v + vlen; 301 for (; cp < cplim; cp++, cp2++) 302 if (*cp != *cp2) 303 goto on1; 304 /* 305 * This extra grot is in case we are explicitly asked 306 * to look up the default. Ugh! 307 * 308 * Never return the root node itself, it seems to cause a 309 * lot of confusion. 310 */ 311 if (t->rn_flags & RNF_ROOT) 312 t = t->rn_dupedkey; 313 return t; 314 on1: 315 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */ 316 for (b = 7; (test >>= 1) > 0;) 317 b--; 318 matched_off = cp - v; 319 b += matched_off << 3; 320 rn_bit = -1 - b; 321 /* 322 * If there is a host route in a duped-key chain, it will be first. 323 */ 324 if ((saved_t = t)->rn_mask == 0) 325 t = t->rn_dupedkey; 326 for (; t; t = t->rn_dupedkey) 327 /* 328 * Even if we don't match exactly as a host, 329 * we may match if the leaf we wound up at is 330 * a route to a net. 331 */ 332 if (t->rn_flags & RNF_NORMAL) { 333 if (rn_bit <= t->rn_bit) 334 return t; 335 } else if (rn_satisfies_leaf(v, t, matched_off)) 336 return t; 337 t = saved_t; 338 /* start searching up the tree */ 339 do { 340 register struct radix_mask *m; 341 t = t->rn_parent; 342 m = t->rn_mklist; 343 /* 344 * If non-contiguous masks ever become important 345 * we can restore the masking and open coding of 346 * the search and satisfaction test and put the 347 * calculation of "off" back before the "do". 348 */ 349 while (m) { 350 if (m->rm_flags & RNF_NORMAL) { 351 if (rn_bit <= m->rm_bit) 352 return (m->rm_leaf); 353 } else { 354 off = min(t->rn_offset, matched_off); 355 x = rn_search_m(v, t, m->rm_mask); 356 while (x && x->rn_mask != m->rm_mask) 357 x = x->rn_dupedkey; 358 if (x && rn_satisfies_leaf(v, x, off)) 359 return x; 360 } 361 m = m->rm_mklist; 362 } 363 } while (t != top); 364 return 0; 365 } 366 367 #ifdef RN_DEBUG 368 int rn_nodenum; 369 struct radix_node *rn_clist; 370 int rn_saveinfo; 371 int rn_debug = 1; 372 #endif 373 374 /* 375 * Whenever we add a new leaf to the tree, we also add a parent node, 376 * so we allocate them as an array of two elements: the first one must be 377 * the leaf (see RNTORT() in route.c), the second one is the parent. 378 * This routine initializes the relevant fields of the nodes, so that 379 * the leaf is the left child of the parent node, and both nodes have 380 * (almost) all all fields filled as appropriate. 381 * (XXX some fields are left unset, see the '#if 0' section). 382 * The function returns a pointer to the parent node. 383 */ 384 385 static struct radix_node * 386 rn_newpair(v, b, nodes) 387 void *v; 388 int b; 389 struct radix_node nodes[2]; 390 { 391 register struct radix_node *tt = nodes, *t = tt + 1; 392 t->rn_bit = b; 393 t->rn_bmask = 0x80 >> (b & 7); 394 t->rn_left = tt; 395 t->rn_offset = b >> 3; 396 397 #if 0 /* XXX perhaps we should fill these fields as well. */ 398 t->rn_parent = t->rn_right = NULL; 399 400 tt->rn_mask = NULL; 401 tt->rn_dupedkey = NULL; 402 tt->rn_bmask = 0; 403 #endif 404 tt->rn_bit = -1; 405 tt->rn_key = (caddr_t)v; 406 tt->rn_parent = t; 407 tt->rn_flags = t->rn_flags = RNF_ACTIVE; 408 tt->rn_mklist = t->rn_mklist = 0; 409 #ifdef RN_DEBUG 410 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 411 tt->rn_twin = t; 412 tt->rn_ybro = rn_clist; 413 rn_clist = tt; 414 #endif 415 return t; 416 } 417 418 static struct radix_node * 419 rn_insert(v_arg, head, dupentry, nodes) 420 void *v_arg; 421 struct radix_node_head *head; 422 int *dupentry; 423 struct radix_node nodes[2]; 424 { 425 caddr_t v = v_arg; 426 struct radix_node *top = head->rnh_treetop; 427 int head_off = top->rn_offset, vlen = (int)LEN(v); 428 register struct radix_node *t = rn_search(v_arg, top); 429 register caddr_t cp = v + head_off; 430 register int b; 431 struct radix_node *tt; 432 /* 433 * Find first bit at which v and t->rn_key differ 434 */ 435 { 436 register caddr_t cp2 = t->rn_key + head_off; 437 register int cmp_res; 438 caddr_t cplim = v + vlen; 439 440 while (cp < cplim) 441 if (*cp2++ != *cp++) 442 goto on1; 443 *dupentry = 1; 444 return t; 445 on1: 446 *dupentry = 0; 447 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff; 448 for (b = (cp - v) << 3; cmp_res; b--) 449 cmp_res >>= 1; 450 } 451 { 452 register struct radix_node *p, *x = top; 453 cp = v; 454 do { 455 p = x; 456 if (cp[x->rn_offset] & x->rn_bmask) 457 x = x->rn_right; 458 else 459 x = x->rn_left; 460 } while (b > (unsigned) x->rn_bit); 461 /* x->rn_bit < b && x->rn_bit >= 0 */ 462 #ifdef RN_DEBUG 463 if (rn_debug) 464 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p); 465 #endif 466 t = rn_newpair(v_arg, b, nodes); 467 tt = t->rn_left; 468 if ((cp[p->rn_offset] & p->rn_bmask) == 0) 469 p->rn_left = t; 470 else 471 p->rn_right = t; 472 x->rn_parent = t; 473 t->rn_parent = p; /* frees x, p as temp vars below */ 474 if ((cp[t->rn_offset] & t->rn_bmask) == 0) { 475 t->rn_right = x; 476 } else { 477 t->rn_right = tt; 478 t->rn_left = x; 479 } 480 #ifdef RN_DEBUG 481 if (rn_debug) 482 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p); 483 #endif 484 } 485 return (tt); 486 } 487 488 struct radix_node * 489 rn_addmask(n_arg, search, skip) 490 int search, skip; 491 void *n_arg; 492 { 493 caddr_t netmask = (caddr_t)n_arg; 494 register struct radix_node *x; 495 register caddr_t cp, cplim; 496 register int b = 0, mlen, j; 497 int maskduplicated, m0, isnormal; 498 struct radix_node *saved_x; 499 static int last_zeroed = 0; 500 501 if ((mlen = LEN(netmask)) > max_keylen) 502 mlen = max_keylen; 503 if (skip == 0) 504 skip = 1; 505 if (mlen <= skip) 506 return (mask_rnhead->rnh_nodes); 507 if (skip > 1) 508 bcopy(rn_ones + 1, addmask_key + 1, skip - 1); 509 if ((m0 = mlen) > skip) 510 bcopy(netmask + skip, addmask_key + skip, mlen - skip); 511 /* 512 * Trim trailing zeroes. 513 */ 514 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;) 515 cp--; 516 mlen = cp - addmask_key; 517 if (mlen <= skip) { 518 if (m0 >= last_zeroed) 519 last_zeroed = mlen; 520 return (mask_rnhead->rnh_nodes); 521 } 522 if (m0 < last_zeroed) 523 bzero(addmask_key + m0, last_zeroed - m0); 524 *addmask_key = last_zeroed = mlen; 525 x = rn_search(addmask_key, rn_masktop); 526 if (bcmp(addmask_key, x->rn_key, mlen) != 0) 527 x = 0; 528 if (x || search) 529 return (x); 530 R_Zalloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x)); 531 if ((saved_x = x) == 0) 532 return (0); 533 netmask = cp = (caddr_t)(x + 2); 534 bcopy(addmask_key, cp, mlen); 535 x = rn_insert(cp, mask_rnhead, &maskduplicated, x); 536 if (maskduplicated) { 537 log(LOG_ERR, "rn_addmask: mask impossibly already in tree"); 538 Free(saved_x); 539 return (x); 540 } 541 /* 542 * Calculate index of mask, and check for normalcy. 543 * First find the first byte with a 0 bit, then if there are 544 * more bits left (remember we already trimmed the trailing 0's), 545 * the pattern must be one of those in normal_chars[], or we have 546 * a non-contiguous mask. 547 */ 548 cplim = netmask + mlen; 549 isnormal = 1; 550 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;) 551 cp++; 552 if (cp != cplim) { 553 static char normal_chars[] = { 554 0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff}; 555 556 for (j = 0x80; (j & *cp) != 0; j >>= 1) 557 b++; 558 if (*cp != normal_chars[b] || cp != (cplim - 1)) 559 isnormal = 0; 560 } 561 b += (cp - netmask) << 3; 562 x->rn_bit = -1 - b; 563 if (isnormal) 564 x->rn_flags |= RNF_NORMAL; 565 return (x); 566 } 567 568 static int /* XXX: arbitrary ordering for non-contiguous masks */ 569 rn_lexobetter(m_arg, n_arg) 570 void *m_arg, *n_arg; 571 { 572 register u_char *mp = m_arg, *np = n_arg, *lim; 573 574 if (LEN(mp) > LEN(np)) 575 return 1; /* not really, but need to check longer one first */ 576 if (LEN(mp) == LEN(np)) 577 for (lim = mp + LEN(mp); mp < lim;) 578 if (*mp++ > *np++) 579 return 1; 580 return 0; 581 } 582 583 static struct radix_mask * 584 rn_new_radix_mask(tt, next) 585 register struct radix_node *tt; 586 register struct radix_mask *next; 587 { 588 register struct radix_mask *m; 589 590 MKGet(m); 591 if (m == 0) { 592 log(LOG_ERR, "Mask for route not entered\n"); 593 return (0); 594 } 595 bzero(m, sizeof *m); 596 m->rm_bit = tt->rn_bit; 597 m->rm_flags = tt->rn_flags; 598 if (tt->rn_flags & RNF_NORMAL) 599 m->rm_leaf = tt; 600 else 601 m->rm_mask = tt->rn_mask; 602 m->rm_mklist = next; 603 tt->rn_mklist = m; 604 return m; 605 } 606 607 struct radix_node * 608 rn_addroute(v_arg, n_arg, head, treenodes) 609 void *v_arg, *n_arg; 610 struct radix_node_head *head; 611 struct radix_node treenodes[2]; 612 { 613 caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg; 614 register struct radix_node *t, *x = 0, *tt; 615 struct radix_node *saved_tt, *top = head->rnh_treetop; 616 short b = 0, b_leaf = 0; 617 int keyduplicated; 618 caddr_t mmask; 619 struct radix_mask *m, **mp; 620 621 /* 622 * In dealing with non-contiguous masks, there may be 623 * many different routes which have the same mask. 624 * We will find it useful to have a unique pointer to 625 * the mask to speed avoiding duplicate references at 626 * nodes and possibly save time in calculating indices. 627 */ 628 if (netmask) { 629 if ((x = rn_addmask(netmask, 0, top->rn_offset)) == 0) 630 return (0); 631 b_leaf = x->rn_bit; 632 b = -1 - x->rn_bit; 633 netmask = x->rn_key; 634 } 635 /* 636 * Deal with duplicated keys: attach node to previous instance 637 */ 638 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes); 639 if (keyduplicated) { 640 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) { 641 #ifdef RADIX_MPATH 642 /* permit multipath, if enabled for the family */ 643 if (rn_mpath_capable(head) && netmask == tt->rn_mask) { 644 /* 645 * go down to the end of multipaths, so that 646 * new entry goes into the end of rn_dupedkey 647 * chain. 648 */ 649 do { 650 t = tt; 651 tt = tt->rn_dupedkey; 652 } while (tt && t->rn_mask == tt->rn_mask); 653 break; 654 } 655 #endif 656 if (tt->rn_mask == netmask) 657 return (0); 658 if (netmask == 0 || 659 (tt->rn_mask && 660 ((b_leaf < tt->rn_bit) /* index(netmask) > node */ 661 || rn_refines(netmask, tt->rn_mask) 662 || rn_lexobetter(netmask, tt->rn_mask)))) 663 break; 664 } 665 /* 666 * If the mask is not duplicated, we wouldn't 667 * find it among possible duplicate key entries 668 * anyway, so the above test doesn't hurt. 669 * 670 * We sort the masks for a duplicated key the same way as 671 * in a masklist -- most specific to least specific. 672 * This may require the unfortunate nuisance of relocating 673 * the head of the list. 674 * 675 * We also reverse, or doubly link the list through the 676 * parent pointer. 677 */ 678 if (tt == saved_tt) { 679 struct radix_node *xx = x; 680 /* link in at head of list */ 681 (tt = treenodes)->rn_dupedkey = t; 682 tt->rn_flags = t->rn_flags; 683 tt->rn_parent = x = t->rn_parent; 684 t->rn_parent = tt; /* parent */ 685 if (x->rn_left == t) 686 x->rn_left = tt; 687 else 688 x->rn_right = tt; 689 saved_tt = tt; x = xx; 690 } else { 691 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey; 692 t->rn_dupedkey = tt; 693 tt->rn_parent = t; /* parent */ 694 if (tt->rn_dupedkey) /* parent */ 695 tt->rn_dupedkey->rn_parent = tt; /* parent */ 696 } 697 #ifdef RN_DEBUG 698 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 699 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 700 #endif 701 tt->rn_key = (caddr_t) v; 702 tt->rn_bit = -1; 703 tt->rn_flags = RNF_ACTIVE; 704 } 705 /* 706 * Put mask in tree. 707 */ 708 if (netmask) { 709 tt->rn_mask = netmask; 710 tt->rn_bit = x->rn_bit; 711 tt->rn_flags |= x->rn_flags & RNF_NORMAL; 712 } 713 t = saved_tt->rn_parent; 714 if (keyduplicated) 715 goto on2; 716 b_leaf = -1 - t->rn_bit; 717 if (t->rn_right == saved_tt) 718 x = t->rn_left; 719 else 720 x = t->rn_right; 721 /* Promote general routes from below */ 722 if (x->rn_bit < 0) { 723 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey) 724 if (x->rn_mask && (x->rn_bit >= b_leaf) && x->rn_mklist == 0) { 725 *mp = m = rn_new_radix_mask(x, 0); 726 if (m) 727 mp = &m->rm_mklist; 728 } 729 } else if (x->rn_mklist) { 730 /* 731 * Skip over masks whose index is > that of new node 732 */ 733 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 734 if (m->rm_bit >= b_leaf) 735 break; 736 t->rn_mklist = m; *mp = 0; 737 } 738 on2: 739 /* Add new route to highest possible ancestor's list */ 740 if ((netmask == 0) || (b > t->rn_bit )) 741 return tt; /* can't lift at all */ 742 b_leaf = tt->rn_bit; 743 do { 744 x = t; 745 t = t->rn_parent; 746 } while (b <= t->rn_bit && x != top); 747 /* 748 * Search through routes associated with node to 749 * insert new route according to index. 750 * Need same criteria as when sorting dupedkeys to avoid 751 * double loop on deletion. 752 */ 753 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) { 754 if (m->rm_bit < b_leaf) 755 continue; 756 if (m->rm_bit > b_leaf) 757 break; 758 if (m->rm_flags & RNF_NORMAL) { 759 mmask = m->rm_leaf->rn_mask; 760 if (tt->rn_flags & RNF_NORMAL) { 761 log(LOG_ERR, 762 "Non-unique normal route, mask not entered\n"); 763 return tt; 764 } 765 } else 766 mmask = m->rm_mask; 767 if (mmask == netmask) { 768 m->rm_refs++; 769 tt->rn_mklist = m; 770 return tt; 771 } 772 if (rn_refines(netmask, mmask) 773 || rn_lexobetter(netmask, mmask)) 774 break; 775 } 776 *mp = rn_new_radix_mask(tt, *mp); 777 return tt; 778 } 779 780 struct radix_node * 781 rn_delete(v_arg, netmask_arg, head) 782 void *v_arg, *netmask_arg; 783 struct radix_node_head *head; 784 { 785 register struct radix_node *t, *p, *x, *tt; 786 struct radix_mask *m, *saved_m, **mp; 787 struct radix_node *dupedkey, *saved_tt, *top; 788 caddr_t v, netmask; 789 int b, head_off, vlen; 790 791 v = v_arg; 792 netmask = netmask_arg; 793 x = head->rnh_treetop; 794 tt = rn_search(v, x); 795 head_off = x->rn_offset; 796 vlen = LEN(v); 797 saved_tt = tt; 798 top = x; 799 if (tt == 0 || 800 bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off)) 801 return (0); 802 /* 803 * Delete our route from mask lists. 804 */ 805 if (netmask) { 806 if ((x = rn_addmask(netmask, 1, head_off)) == 0) 807 return (0); 808 netmask = x->rn_key; 809 while (tt->rn_mask != netmask) 810 if ((tt = tt->rn_dupedkey) == 0) 811 return (0); 812 } 813 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0) 814 goto on1; 815 if (tt->rn_flags & RNF_NORMAL) { 816 if (m->rm_leaf != tt || m->rm_refs > 0) { 817 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 818 return 0; /* dangling ref could cause disaster */ 819 } 820 } else { 821 if (m->rm_mask != tt->rn_mask) { 822 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 823 goto on1; 824 } 825 if (--m->rm_refs >= 0) 826 goto on1; 827 } 828 b = -1 - tt->rn_bit; 829 t = saved_tt->rn_parent; 830 if (b > t->rn_bit) 831 goto on1; /* Wasn't lifted at all */ 832 do { 833 x = t; 834 t = t->rn_parent; 835 } while (b <= t->rn_bit && x != top); 836 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 837 if (m == saved_m) { 838 *mp = m->rm_mklist; 839 MKFree(m); 840 break; 841 } 842 if (m == 0) { 843 log(LOG_ERR, "rn_delete: couldn't find our annotation\n"); 844 if (tt->rn_flags & RNF_NORMAL) 845 return (0); /* Dangling ref to us */ 846 } 847 on1: 848 /* 849 * Eliminate us from tree 850 */ 851 if (tt->rn_flags & RNF_ROOT) 852 return (0); 853 #ifdef RN_DEBUG 854 /* Get us out of the creation list */ 855 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {} 856 if (t) t->rn_ybro = tt->rn_ybro; 857 #endif 858 t = tt->rn_parent; 859 dupedkey = saved_tt->rn_dupedkey; 860 if (dupedkey) { 861 /* 862 * Here, tt is the deletion target and 863 * saved_tt is the head of the dupekey chain. 864 */ 865 if (tt == saved_tt) { 866 /* remove from head of chain */ 867 x = dupedkey; x->rn_parent = t; 868 if (t->rn_left == tt) 869 t->rn_left = x; 870 else 871 t->rn_right = x; 872 } else { 873 /* find node in front of tt on the chain */ 874 for (x = p = saved_tt; p && p->rn_dupedkey != tt;) 875 p = p->rn_dupedkey; 876 if (p) { 877 p->rn_dupedkey = tt->rn_dupedkey; 878 if (tt->rn_dupedkey) /* parent */ 879 tt->rn_dupedkey->rn_parent = p; 880 /* parent */ 881 } else log(LOG_ERR, "rn_delete: couldn't find us\n"); 882 } 883 t = tt + 1; 884 if (t->rn_flags & RNF_ACTIVE) { 885 #ifndef RN_DEBUG 886 *++x = *t; 887 p = t->rn_parent; 888 #else 889 b = t->rn_info; 890 *++x = *t; 891 t->rn_info = b; 892 p = t->rn_parent; 893 #endif 894 if (p->rn_left == t) 895 p->rn_left = x; 896 else 897 p->rn_right = x; 898 x->rn_left->rn_parent = x; 899 x->rn_right->rn_parent = x; 900 } 901 goto out; 902 } 903 if (t->rn_left == tt) 904 x = t->rn_right; 905 else 906 x = t->rn_left; 907 p = t->rn_parent; 908 if (p->rn_right == t) 909 p->rn_right = x; 910 else 911 p->rn_left = x; 912 x->rn_parent = p; 913 /* 914 * Demote routes attached to us. 915 */ 916 if (t->rn_mklist) { 917 if (x->rn_bit >= 0) { 918 for (mp = &x->rn_mklist; (m = *mp);) 919 mp = &m->rm_mklist; 920 *mp = t->rn_mklist; 921 } else { 922 /* If there are any key,mask pairs in a sibling 923 duped-key chain, some subset will appear sorted 924 in the same order attached to our mklist */ 925 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey) 926 if (m == x->rn_mklist) { 927 struct radix_mask *mm = m->rm_mklist; 928 x->rn_mklist = 0; 929 if (--(m->rm_refs) < 0) 930 MKFree(m); 931 m = mm; 932 } 933 if (m) 934 log(LOG_ERR, 935 "rn_delete: Orphaned Mask %p at %p\n", 936 (void *)m, (void *)x); 937 } 938 } 939 /* 940 * We may be holding an active internal node in the tree. 941 */ 942 x = tt + 1; 943 if (t != x) { 944 #ifndef RN_DEBUG 945 *t = *x; 946 #else 947 b = t->rn_info; 948 *t = *x; 949 t->rn_info = b; 950 #endif 951 t->rn_left->rn_parent = t; 952 t->rn_right->rn_parent = t; 953 p = x->rn_parent; 954 if (p->rn_left == x) 955 p->rn_left = t; 956 else 957 p->rn_right = t; 958 } 959 out: 960 tt->rn_flags &= ~RNF_ACTIVE; 961 tt[1].rn_flags &= ~RNF_ACTIVE; 962 return (tt); 963 } 964 965 /* 966 * This is the same as rn_walktree() except for the parameters and the 967 * exit. 968 */ 969 static int 970 rn_walktree_from(h, a, m, f, w) 971 struct radix_node_head *h; 972 void *a, *m; 973 walktree_f_t *f; 974 void *w; 975 { 976 int error; 977 struct radix_node *base, *next; 978 u_char *xa = (u_char *)a; 979 u_char *xm = (u_char *)m; 980 register struct radix_node *rn, *last = 0 /* shut up gcc */; 981 int stopping = 0; 982 int lastb; 983 984 /* 985 * rn_search_m is sort-of-open-coded here. We cannot use the 986 * function because we need to keep track of the last node seen. 987 */ 988 /* printf("about to search\n"); */ 989 for (rn = h->rnh_treetop; rn->rn_bit >= 0; ) { 990 last = rn; 991 /* printf("rn_bit %d, rn_bmask %x, xm[rn_offset] %x\n", 992 rn->rn_bit, rn->rn_bmask, xm[rn->rn_offset]); */ 993 if (!(rn->rn_bmask & xm[rn->rn_offset])) { 994 break; 995 } 996 if (rn->rn_bmask & xa[rn->rn_offset]) { 997 rn = rn->rn_right; 998 } else { 999 rn = rn->rn_left; 1000 } 1001 } 1002 /* printf("done searching\n"); */ 1003 1004 /* 1005 * Two cases: either we stepped off the end of our mask, 1006 * in which case last == rn, or we reached a leaf, in which 1007 * case we want to start from the last node we looked at. 1008 * Either way, last is the node we want to start from. 1009 */ 1010 rn = last; 1011 lastb = rn->rn_bit; 1012 1013 /* printf("rn %p, lastb %d\n", rn, lastb);*/ 1014 1015 /* 1016 * This gets complicated because we may delete the node 1017 * while applying the function f to it, so we need to calculate 1018 * the successor node in advance. 1019 */ 1020 while (rn->rn_bit >= 0) 1021 rn = rn->rn_left; 1022 1023 while (!stopping) { 1024 /* printf("node %p (%d)\n", rn, rn->rn_bit); */ 1025 base = rn; 1026 /* If at right child go back up, otherwise, go right */ 1027 while (rn->rn_parent->rn_right == rn 1028 && !(rn->rn_flags & RNF_ROOT)) { 1029 rn = rn->rn_parent; 1030 1031 /* if went up beyond last, stop */ 1032 if (rn->rn_bit <= lastb) { 1033 stopping = 1; 1034 /* printf("up too far\n"); */ 1035 /* 1036 * XXX we should jump to the 'Process leaves' 1037 * part, because the values of 'rn' and 'next' 1038 * we compute will not be used. Not a big deal 1039 * because this loop will terminate, but it is 1040 * inefficient and hard to understand! 1041 */ 1042 } 1043 } 1044 1045 /* 1046 * At the top of the tree, no need to traverse the right 1047 * half, prevent the traversal of the entire tree in the 1048 * case of default route. 1049 */ 1050 if (rn->rn_parent->rn_flags & RNF_ROOT) 1051 stopping = 1; 1052 1053 /* Find the next *leaf* since next node might vanish, too */ 1054 for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;) 1055 rn = rn->rn_left; 1056 next = rn; 1057 /* Process leaves */ 1058 while ((rn = base) != 0) { 1059 base = rn->rn_dupedkey; 1060 /* printf("leaf %p\n", rn); */ 1061 if (!(rn->rn_flags & RNF_ROOT) 1062 && (error = (*f)(rn, w))) 1063 return (error); 1064 } 1065 rn = next; 1066 1067 if (rn->rn_flags & RNF_ROOT) { 1068 /* printf("root, stopping"); */ 1069 stopping = 1; 1070 } 1071 1072 } 1073 return 0; 1074 } 1075 1076 static int 1077 rn_walktree(h, f, w) 1078 struct radix_node_head *h; 1079 walktree_f_t *f; 1080 void *w; 1081 { 1082 int error; 1083 struct radix_node *base, *next; 1084 register struct radix_node *rn = h->rnh_treetop; 1085 /* 1086 * This gets complicated because we may delete the node 1087 * while applying the function f to it, so we need to calculate 1088 * the successor node in advance. 1089 */ 1090 1091 /* First time through node, go left */ 1092 while (rn->rn_bit >= 0) 1093 rn = rn->rn_left; 1094 for (;;) { 1095 base = rn; 1096 /* If at right child go back up, otherwise, go right */ 1097 while (rn->rn_parent->rn_right == rn 1098 && (rn->rn_flags & RNF_ROOT) == 0) 1099 rn = rn->rn_parent; 1100 /* Find the next *leaf* since next node might vanish, too */ 1101 for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;) 1102 rn = rn->rn_left; 1103 next = rn; 1104 /* Process leaves */ 1105 while ((rn = base)) { 1106 base = rn->rn_dupedkey; 1107 if (!(rn->rn_flags & RNF_ROOT) 1108 && (error = (*f)(rn, w))) 1109 return (error); 1110 } 1111 rn = next; 1112 if (rn->rn_flags & RNF_ROOT) 1113 return (0); 1114 } 1115 /* NOTREACHED */ 1116 } 1117 1118 /* 1119 * Allocate and initialize an empty tree. This has 3 nodes, which are 1120 * part of the radix_node_head (in the order <left,root,right>) and are 1121 * marked RNF_ROOT so they cannot be freed. 1122 * The leaves have all-zero and all-one keys, with significant 1123 * bits starting at 'off'. 1124 * Return 1 on success, 0 on error. 1125 */ 1126 int 1127 rn_inithead(head, off) 1128 void **head; 1129 int off; 1130 { 1131 register struct radix_node_head *rnh; 1132 register struct radix_node *t, *tt, *ttt; 1133 if (*head) 1134 return (1); 1135 R_Zalloc(rnh, struct radix_node_head *, sizeof (*rnh)); 1136 if (rnh == 0) 1137 return (0); 1138 #ifdef _KERNEL 1139 RADIX_NODE_HEAD_LOCK_INIT(rnh); 1140 #endif 1141 *head = rnh; 1142 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes); 1143 ttt = rnh->rnh_nodes + 2; 1144 t->rn_right = ttt; 1145 t->rn_parent = t; 1146 tt = t->rn_left; /* ... which in turn is rnh->rnh_nodes */ 1147 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE; 1148 tt->rn_bit = -1 - off; 1149 *ttt = *tt; 1150 ttt->rn_key = rn_ones; 1151 rnh->rnh_addaddr = rn_addroute; 1152 rnh->rnh_deladdr = rn_delete; 1153 rnh->rnh_matchaddr = rn_match; 1154 rnh->rnh_lookup = rn_lookup; 1155 rnh->rnh_walktree = rn_walktree; 1156 rnh->rnh_walktree_from = rn_walktree_from; 1157 rnh->rnh_treetop = t; 1158 return (1); 1159 } 1160 1161 void 1162 rn_init() 1163 { 1164 char *cp, *cplim; 1165 #ifdef _KERNEL 1166 struct domain *dom; 1167 1168 for (dom = domains; dom; dom = dom->dom_next) 1169 if (dom->dom_maxrtkey > max_keylen) 1170 max_keylen = dom->dom_maxrtkey; 1171 #endif 1172 if (max_keylen == 0) { 1173 log(LOG_ERR, 1174 "rn_init: radix functions require max_keylen be set\n"); 1175 return; 1176 } 1177 R_Malloc(rn_zeros, char *, 3 * max_keylen); 1178 if (rn_zeros == NULL) 1179 panic("rn_init"); 1180 bzero(rn_zeros, 3 * max_keylen); 1181 rn_ones = cp = rn_zeros + max_keylen; 1182 addmask_key = cplim = rn_ones + max_keylen; 1183 while (cp < cplim) 1184 *cp++ = -1; 1185 if (rn_inithead((void **)(void *)&mask_rnhead, 0) == 0) 1186 panic("rn_init 2"); 1187 }
Cache object: 3a0ab3ab44c85461cb2abd52a51deb86
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