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 * $FreeBSD$ 31 */ 32 33 /* 34 * Routines to build and maintain radix trees for routing lookups. 35 */ 36 #include <sys/param.h> 37 #ifdef _KERNEL 38 #include <sys/lock.h> 39 #include <sys/mutex.h> 40 #include <sys/rwlock.h> 41 #include <sys/systm.h> 42 #include <sys/malloc.h> 43 #include <sys/syslog.h> 44 #include <net/radix.h> 45 #include "opt_mpath.h" 46 #ifdef RADIX_MPATH 47 #include <net/radix_mpath.h> 48 #endif 49 #else /* !_KERNEL */ 50 #include <stdio.h> 51 #include <strings.h> 52 #include <stdlib.h> 53 #define log(x, arg...) fprintf(stderr, ## arg) 54 #define panic(x) fprintf(stderr, "PANIC: %s", x), exit(1) 55 #define min(a, b) ((a) < (b) ? (a) : (b) ) 56 #include <net/radix.h> 57 #endif /* !_KERNEL */ 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 void rn_detachhead_internal(void **head); 70 static int rn_inithead_internal(void **head, int off); 71 72 #define RADIX_MAX_KEY_LEN 32 73 74 static char rn_zeros[RADIX_MAX_KEY_LEN]; 75 static char rn_ones[RADIX_MAX_KEY_LEN] = { 76 -1, -1, -1, -1, -1, -1, -1, -1, 77 -1, -1, -1, -1, -1, -1, -1, -1, 78 -1, -1, -1, -1, -1, -1, -1, -1, 79 -1, -1, -1, -1, -1, -1, -1, -1, 80 }; 81 82 83 static int rn_lexobetter(void *m_arg, void *n_arg); 84 static struct radix_mask * 85 rn_new_radix_mask(struct radix_node *tt, 86 struct radix_mask *next); 87 static int rn_satisfies_leaf(char *trial, struct radix_node *leaf, 88 int skip); 89 90 /* 91 * The data structure for the keys is a radix tree with one way 92 * branching removed. The index rn_bit at an internal node n represents a bit 93 * position to be tested. The tree is arranged so that all descendants 94 * of a node n have keys whose bits all agree up to position rn_bit - 1. 95 * (We say the index of n is rn_bit.) 96 * 97 * There is at least one descendant which has a one bit at position rn_bit, 98 * and at least one with a zero there. 99 * 100 * A route is determined by a pair of key and mask. We require that the 101 * bit-wise logical and of the key and mask to be the key. 102 * We define the index of a route to associated with the mask to be 103 * the first bit number in the mask where 0 occurs (with bit number 0 104 * representing the highest order bit). 105 * 106 * We say a mask is normal if every bit is 0, past the index of the mask. 107 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_bit, 108 * and m is a normal mask, then the route applies to every descendant of n. 109 * If the index(m) < rn_bit, this implies the trailing last few bits of k 110 * before bit b are all 0, (and hence consequently true of every descendant 111 * of n), so the route applies to all descendants of the node as well. 112 * 113 * Similar logic shows that a non-normal mask m such that 114 * index(m) <= index(n) could potentially apply to many children of n. 115 * Thus, for each non-host route, we attach its mask to a list at an internal 116 * node as high in the tree as we can go. 117 * 118 * The present version of the code makes use of normal routes in short- 119 * circuiting an explict mask and compare operation when testing whether 120 * a key satisfies a normal route, and also in remembering the unique leaf 121 * that governs a subtree. 122 */ 123 124 /* 125 * Most of the functions in this code assume that the key/mask arguments 126 * are sockaddr-like structures, where the first byte is an u_char 127 * indicating the size of the entire structure. 128 * 129 * To make the assumption more explicit, we use the LEN() macro to access 130 * this field. It is safe to pass an expression with side effects 131 * to LEN() as the argument is evaluated only once. 132 * We cast the result to int as this is the dominant usage. 133 */ 134 #define LEN(x) ( (int) (*(const u_char *)(x)) ) 135 136 /* 137 * XXX THIS NEEDS TO BE FIXED 138 * In the code, pointers to keys and masks are passed as either 139 * 'void *' (because callers use to pass pointers of various kinds), or 140 * 'caddr_t' (which is fine for pointer arithmetics, but not very 141 * clean when you dereference it to access data). Furthermore, caddr_t 142 * is really 'char *', while the natural type to operate on keys and 143 * masks would be 'u_char'. This mismatch require a lot of casts and 144 * intermediate variables to adapt types that clutter the code. 145 */ 146 147 /* 148 * Search a node in the tree matching the key. 149 */ 150 static struct radix_node * 151 rn_search(v_arg, head) 152 void *v_arg; 153 struct radix_node *head; 154 { 155 register struct radix_node *x; 156 register caddr_t v; 157 158 for (x = head, v = v_arg; x->rn_bit >= 0;) { 159 if (x->rn_bmask & v[x->rn_offset]) 160 x = x->rn_right; 161 else 162 x = x->rn_left; 163 } 164 return (x); 165 } 166 167 /* 168 * Same as above, but with an additional mask. 169 * XXX note this function is used only once. 170 */ 171 static struct radix_node * 172 rn_search_m(v_arg, head, m_arg) 173 struct radix_node *head; 174 void *v_arg, *m_arg; 175 { 176 register struct radix_node *x; 177 register caddr_t v = v_arg, m = m_arg; 178 179 for (x = head; x->rn_bit >= 0;) { 180 if ((x->rn_bmask & m[x->rn_offset]) && 181 (x->rn_bmask & v[x->rn_offset])) 182 x = x->rn_right; 183 else 184 x = x->rn_left; 185 } 186 return x; 187 } 188 189 int 190 rn_refines(m_arg, n_arg) 191 void *m_arg, *n_arg; 192 { 193 register caddr_t m = m_arg, n = n_arg; 194 register caddr_t lim, lim2 = lim = n + LEN(n); 195 int longer = LEN(n++) - LEN(m++); 196 int masks_are_equal = 1; 197 198 if (longer > 0) 199 lim -= longer; 200 while (n < lim) { 201 if (*n & ~(*m)) 202 return 0; 203 if (*n++ != *m++) 204 masks_are_equal = 0; 205 } 206 while (n < lim2) 207 if (*n++) 208 return 0; 209 if (masks_are_equal && (longer < 0)) 210 for (lim2 = m - longer; m < lim2; ) 211 if (*m++) 212 return 1; 213 return (!masks_are_equal); 214 } 215 216 struct radix_node * 217 rn_lookup(v_arg, m_arg, head) 218 void *v_arg, *m_arg; 219 struct radix_node_head *head; 220 { 221 register struct radix_node *x; 222 caddr_t netmask = 0; 223 224 if (m_arg) { 225 x = rn_addmask(m_arg, head->rnh_masks, 1, 226 head->rnh_treetop->rn_offset); 227 if (x == 0) 228 return (0); 229 netmask = x->rn_key; 230 } 231 x = rn_match(v_arg, head); 232 if (x && netmask) { 233 while (x && x->rn_mask != netmask) 234 x = x->rn_dupedkey; 235 } 236 return x; 237 } 238 239 static int 240 rn_satisfies_leaf(trial, leaf, skip) 241 char *trial; 242 register struct radix_node *leaf; 243 int skip; 244 { 245 register char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask; 246 char *cplim; 247 int length = min(LEN(cp), LEN(cp2)); 248 249 if (cp3 == NULL) 250 cp3 = rn_ones; 251 else 252 length = min(length, LEN(cp3)); 253 cplim = cp + length; cp3 += skip; cp2 += skip; 254 for (cp += skip; cp < cplim; cp++, cp2++, cp3++) 255 if ((*cp ^ *cp2) & *cp3) 256 return 0; 257 return 1; 258 } 259 260 struct radix_node * 261 rn_match(v_arg, head) 262 void *v_arg; 263 struct radix_node_head *head; 264 { 265 caddr_t v = v_arg; 266 register struct radix_node *t = head->rnh_treetop, *x; 267 register caddr_t cp = v, cp2; 268 caddr_t cplim; 269 struct radix_node *saved_t, *top = t; 270 int off = t->rn_offset, vlen = LEN(cp), matched_off; 271 register int test, b, rn_bit; 272 273 /* 274 * Open code rn_search(v, top) to avoid overhead of extra 275 * subroutine call. 276 */ 277 for (; t->rn_bit >= 0; ) { 278 if (t->rn_bmask & cp[t->rn_offset]) 279 t = t->rn_right; 280 else 281 t = t->rn_left; 282 } 283 /* 284 * See if we match exactly as a host destination 285 * or at least learn how many bits match, for normal mask finesse. 286 * 287 * It doesn't hurt us to limit how many bytes to check 288 * to the length of the mask, since if it matches we had a genuine 289 * match and the leaf we have is the most specific one anyway; 290 * if it didn't match with a shorter length it would fail 291 * with a long one. This wins big for class B&C netmasks which 292 * are probably the most common case... 293 */ 294 if (t->rn_mask) 295 vlen = *(u_char *)t->rn_mask; 296 cp += off; cp2 = t->rn_key + off; cplim = v + vlen; 297 for (; cp < cplim; cp++, cp2++) 298 if (*cp != *cp2) 299 goto on1; 300 /* 301 * This extra grot is in case we are explicitly asked 302 * to look up the default. Ugh! 303 * 304 * Never return the root node itself, it seems to cause a 305 * lot of confusion. 306 */ 307 if (t->rn_flags & RNF_ROOT) 308 t = t->rn_dupedkey; 309 return t; 310 on1: 311 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */ 312 for (b = 7; (test >>= 1) > 0;) 313 b--; 314 matched_off = cp - v; 315 b += matched_off << 3; 316 rn_bit = -1 - b; 317 /* 318 * If there is a host route in a duped-key chain, it will be first. 319 */ 320 if ((saved_t = t)->rn_mask == 0) 321 t = t->rn_dupedkey; 322 for (; t; t = t->rn_dupedkey) 323 /* 324 * Even if we don't match exactly as a host, 325 * we may match if the leaf we wound up at is 326 * a route to a net. 327 */ 328 if (t->rn_flags & RNF_NORMAL) { 329 if (rn_bit <= t->rn_bit) 330 return t; 331 } else if (rn_satisfies_leaf(v, t, matched_off)) 332 return t; 333 t = saved_t; 334 /* start searching up the tree */ 335 do { 336 register struct radix_mask *m; 337 t = t->rn_parent; 338 m = t->rn_mklist; 339 /* 340 * If non-contiguous masks ever become important 341 * we can restore the masking and open coding of 342 * the search and satisfaction test and put the 343 * calculation of "off" back before the "do". 344 */ 345 while (m) { 346 if (m->rm_flags & RNF_NORMAL) { 347 if (rn_bit <= m->rm_bit) 348 return (m->rm_leaf); 349 } else { 350 off = min(t->rn_offset, matched_off); 351 x = rn_search_m(v, t, m->rm_mask); 352 while (x && x->rn_mask != m->rm_mask) 353 x = x->rn_dupedkey; 354 if (x && rn_satisfies_leaf(v, x, off)) 355 return x; 356 } 357 m = m->rm_mklist; 358 } 359 } while (t != top); 360 return 0; 361 } 362 363 #ifdef RN_DEBUG 364 int rn_nodenum; 365 struct radix_node *rn_clist; 366 int rn_saveinfo; 367 int rn_debug = 1; 368 #endif 369 370 /* 371 * Whenever we add a new leaf to the tree, we also add a parent node, 372 * so we allocate them as an array of two elements: the first one must be 373 * the leaf (see RNTORT() in route.c), the second one is the parent. 374 * This routine initializes the relevant fields of the nodes, so that 375 * the leaf is the left child of the parent node, and both nodes have 376 * (almost) all all fields filled as appropriate. 377 * (XXX some fields are left unset, see the '#if 0' section). 378 * The function returns a pointer to the parent node. 379 */ 380 381 static struct radix_node * 382 rn_newpair(v, b, nodes) 383 void *v; 384 int b; 385 struct radix_node nodes[2]; 386 { 387 register struct radix_node *tt = nodes, *t = tt + 1; 388 t->rn_bit = b; 389 t->rn_bmask = 0x80 >> (b & 7); 390 t->rn_left = tt; 391 t->rn_offset = b >> 3; 392 393 #if 0 /* XXX perhaps we should fill these fields as well. */ 394 t->rn_parent = t->rn_right = NULL; 395 396 tt->rn_mask = NULL; 397 tt->rn_dupedkey = NULL; 398 tt->rn_bmask = 0; 399 #endif 400 tt->rn_bit = -1; 401 tt->rn_key = (caddr_t)v; 402 tt->rn_parent = t; 403 tt->rn_flags = t->rn_flags = RNF_ACTIVE; 404 tt->rn_mklist = t->rn_mklist = 0; 405 #ifdef RN_DEBUG 406 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 407 tt->rn_twin = t; 408 tt->rn_ybro = rn_clist; 409 rn_clist = tt; 410 #endif 411 return t; 412 } 413 414 static struct radix_node * 415 rn_insert(v_arg, head, dupentry, nodes) 416 void *v_arg; 417 struct radix_node_head *head; 418 int *dupentry; 419 struct radix_node nodes[2]; 420 { 421 caddr_t v = v_arg; 422 struct radix_node *top = head->rnh_treetop; 423 int head_off = top->rn_offset, vlen = LEN(v); 424 register struct radix_node *t = rn_search(v_arg, top); 425 register caddr_t cp = v + head_off; 426 register int b; 427 struct radix_node *tt; 428 /* 429 * Find first bit at which v and t->rn_key differ 430 */ 431 { 432 register caddr_t cp2 = t->rn_key + head_off; 433 register int cmp_res; 434 caddr_t cplim = v + vlen; 435 436 while (cp < cplim) 437 if (*cp2++ != *cp++) 438 goto on1; 439 *dupentry = 1; 440 return t; 441 on1: 442 *dupentry = 0; 443 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff; 444 for (b = (cp - v) << 3; cmp_res; b--) 445 cmp_res >>= 1; 446 } 447 { 448 register struct radix_node *p, *x = top; 449 cp = v; 450 do { 451 p = x; 452 if (cp[x->rn_offset] & x->rn_bmask) 453 x = x->rn_right; 454 else 455 x = x->rn_left; 456 } while (b > (unsigned) x->rn_bit); 457 /* x->rn_bit < b && x->rn_bit >= 0 */ 458 #ifdef RN_DEBUG 459 if (rn_debug) 460 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p); 461 #endif 462 t = rn_newpair(v_arg, b, nodes); 463 tt = t->rn_left; 464 if ((cp[p->rn_offset] & p->rn_bmask) == 0) 465 p->rn_left = t; 466 else 467 p->rn_right = t; 468 x->rn_parent = t; 469 t->rn_parent = p; /* frees x, p as temp vars below */ 470 if ((cp[t->rn_offset] & t->rn_bmask) == 0) { 471 t->rn_right = x; 472 } else { 473 t->rn_right = tt; 474 t->rn_left = x; 475 } 476 #ifdef RN_DEBUG 477 if (rn_debug) 478 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p); 479 #endif 480 } 481 return (tt); 482 } 483 484 struct radix_node * 485 rn_addmask(void *n_arg, struct radix_node_head *maskhead, int search, int skip) 486 { 487 caddr_t netmask = (caddr_t)n_arg; 488 register struct radix_node *x; 489 register caddr_t cp, cplim; 490 register int b = 0, mlen, j; 491 int maskduplicated, isnormal; 492 struct radix_node *saved_x; 493 char addmask_key[RADIX_MAX_KEY_LEN]; 494 495 if ((mlen = LEN(netmask)) > RADIX_MAX_KEY_LEN) 496 mlen = RADIX_MAX_KEY_LEN; 497 if (skip == 0) 498 skip = 1; 499 if (mlen <= skip) 500 return (maskhead->rnh_nodes); 501 502 bzero(addmask_key, RADIX_MAX_KEY_LEN); 503 if (skip > 1) 504 bcopy(rn_ones + 1, addmask_key + 1, skip - 1); 505 bcopy(netmask + skip, addmask_key + skip, mlen - skip); 506 /* 507 * Trim trailing zeroes. 508 */ 509 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;) 510 cp--; 511 mlen = cp - addmask_key; 512 if (mlen <= skip) 513 return (maskhead->rnh_nodes); 514 *addmask_key = mlen; 515 x = rn_search(addmask_key, maskhead->rnh_treetop); 516 if (bcmp(addmask_key, x->rn_key, mlen) != 0) 517 x = 0; 518 if (x || search) 519 return (x); 520 R_Zalloc(x, struct radix_node *, RADIX_MAX_KEY_LEN + 2 * sizeof (*x)); 521 if ((saved_x = x) == 0) 522 return (0); 523 netmask = cp = (caddr_t)(x + 2); 524 bcopy(addmask_key, cp, mlen); 525 x = rn_insert(cp, maskhead, &maskduplicated, x); 526 if (maskduplicated) { 527 log(LOG_ERR, "rn_addmask: mask impossibly already in tree"); 528 Free(saved_x); 529 return (x); 530 } 531 /* 532 * Calculate index of mask, and check for normalcy. 533 * First find the first byte with a 0 bit, then if there are 534 * more bits left (remember we already trimmed the trailing 0's), 535 * the pattern must be one of those in normal_chars[], or we have 536 * a non-contiguous mask. 537 */ 538 cplim = netmask + mlen; 539 isnormal = 1; 540 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;) 541 cp++; 542 if (cp != cplim) { 543 static char normal_chars[] = { 544 0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff}; 545 546 for (j = 0x80; (j & *cp) != 0; j >>= 1) 547 b++; 548 if (*cp != normal_chars[b] || cp != (cplim - 1)) 549 isnormal = 0; 550 } 551 b += (cp - netmask) << 3; 552 x->rn_bit = -1 - b; 553 if (isnormal) 554 x->rn_flags |= RNF_NORMAL; 555 return (x); 556 } 557 558 static int /* XXX: arbitrary ordering for non-contiguous masks */ 559 rn_lexobetter(m_arg, n_arg) 560 void *m_arg, *n_arg; 561 { 562 register u_char *mp = m_arg, *np = n_arg, *lim; 563 564 if (LEN(mp) > LEN(np)) 565 return 1; /* not really, but need to check longer one first */ 566 if (LEN(mp) == LEN(np)) 567 for (lim = mp + LEN(mp); mp < lim;) 568 if (*mp++ > *np++) 569 return 1; 570 return 0; 571 } 572 573 static struct radix_mask * 574 rn_new_radix_mask(tt, next) 575 register struct radix_node *tt; 576 register struct radix_mask *next; 577 { 578 register struct radix_mask *m; 579 580 R_Malloc(m, struct radix_mask *, sizeof (struct radix_mask)); 581 if (m == 0) { 582 log(LOG_ERR, "Failed to allocate route mask\n"); 583 return (0); 584 } 585 bzero(m, sizeof(*m)); 586 m->rm_bit = tt->rn_bit; 587 m->rm_flags = tt->rn_flags; 588 if (tt->rn_flags & RNF_NORMAL) 589 m->rm_leaf = tt; 590 else 591 m->rm_mask = tt->rn_mask; 592 m->rm_mklist = next; 593 tt->rn_mklist = m; 594 return m; 595 } 596 597 struct radix_node * 598 rn_addroute(v_arg, n_arg, head, treenodes) 599 void *v_arg, *n_arg; 600 struct radix_node_head *head; 601 struct radix_node treenodes[2]; 602 { 603 caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg; 604 register struct radix_node *t, *x = 0, *tt; 605 struct radix_node *saved_tt, *top = head->rnh_treetop; 606 short b = 0, b_leaf = 0; 607 int keyduplicated; 608 caddr_t mmask; 609 struct radix_mask *m, **mp; 610 611 /* 612 * In dealing with non-contiguous masks, there may be 613 * many different routes which have the same mask. 614 * We will find it useful to have a unique pointer to 615 * the mask to speed avoiding duplicate references at 616 * nodes and possibly save time in calculating indices. 617 */ 618 if (netmask) { 619 x = rn_addmask(netmask, head->rnh_masks, 0, top->rn_offset); 620 if (x == NULL) 621 return (0); 622 b_leaf = x->rn_bit; 623 b = -1 - x->rn_bit; 624 netmask = x->rn_key; 625 } 626 /* 627 * Deal with duplicated keys: attach node to previous instance 628 */ 629 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes); 630 if (keyduplicated) { 631 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) { 632 #ifdef RADIX_MPATH 633 /* permit multipath, if enabled for the family */ 634 if (rn_mpath_capable(head) && netmask == tt->rn_mask) { 635 /* 636 * go down to the end of multipaths, so that 637 * new entry goes into the end of rn_dupedkey 638 * chain. 639 */ 640 do { 641 t = tt; 642 tt = tt->rn_dupedkey; 643 } while (tt && t->rn_mask == tt->rn_mask); 644 break; 645 } 646 #endif 647 if (tt->rn_mask == netmask) 648 return (0); 649 if (netmask == 0 || 650 (tt->rn_mask && 651 ((b_leaf < tt->rn_bit) /* index(netmask) > node */ 652 || rn_refines(netmask, tt->rn_mask) 653 || rn_lexobetter(netmask, tt->rn_mask)))) 654 break; 655 } 656 /* 657 * If the mask is not duplicated, we wouldn't 658 * find it among possible duplicate key entries 659 * anyway, so the above test doesn't hurt. 660 * 661 * We sort the masks for a duplicated key the same way as 662 * in a masklist -- most specific to least specific. 663 * This may require the unfortunate nuisance of relocating 664 * the head of the list. 665 * 666 * We also reverse, or doubly link the list through the 667 * parent pointer. 668 */ 669 if (tt == saved_tt) { 670 struct radix_node *xx = x; 671 /* link in at head of list */ 672 (tt = treenodes)->rn_dupedkey = t; 673 tt->rn_flags = t->rn_flags; 674 tt->rn_parent = x = t->rn_parent; 675 t->rn_parent = tt; /* parent */ 676 if (x->rn_left == t) 677 x->rn_left = tt; 678 else 679 x->rn_right = tt; 680 saved_tt = tt; x = xx; 681 } else { 682 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey; 683 t->rn_dupedkey = tt; 684 tt->rn_parent = t; /* parent */ 685 if (tt->rn_dupedkey) /* parent */ 686 tt->rn_dupedkey->rn_parent = tt; /* parent */ 687 } 688 #ifdef RN_DEBUG 689 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 690 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 691 #endif 692 tt->rn_key = (caddr_t) v; 693 tt->rn_bit = -1; 694 tt->rn_flags = RNF_ACTIVE; 695 } 696 /* 697 * Put mask in tree. 698 */ 699 if (netmask) { 700 tt->rn_mask = netmask; 701 tt->rn_bit = x->rn_bit; 702 tt->rn_flags |= x->rn_flags & RNF_NORMAL; 703 } 704 t = saved_tt->rn_parent; 705 if (keyduplicated) 706 goto on2; 707 b_leaf = -1 - t->rn_bit; 708 if (t->rn_right == saved_tt) 709 x = t->rn_left; 710 else 711 x = t->rn_right; 712 /* Promote general routes from below */ 713 if (x->rn_bit < 0) { 714 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey) 715 if (x->rn_mask && (x->rn_bit >= b_leaf) && x->rn_mklist == 0) { 716 *mp = m = rn_new_radix_mask(x, 0); 717 if (m) 718 mp = &m->rm_mklist; 719 } 720 } else if (x->rn_mklist) { 721 /* 722 * Skip over masks whose index is > that of new node 723 */ 724 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 725 if (m->rm_bit >= b_leaf) 726 break; 727 t->rn_mklist = m; *mp = 0; 728 } 729 on2: 730 /* Add new route to highest possible ancestor's list */ 731 if ((netmask == 0) || (b > t->rn_bit )) 732 return tt; /* can't lift at all */ 733 b_leaf = tt->rn_bit; 734 do { 735 x = t; 736 t = t->rn_parent; 737 } while (b <= t->rn_bit && x != top); 738 /* 739 * Search through routes associated with node to 740 * insert new route according to index. 741 * Need same criteria as when sorting dupedkeys to avoid 742 * double loop on deletion. 743 */ 744 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) { 745 if (m->rm_bit < b_leaf) 746 continue; 747 if (m->rm_bit > b_leaf) 748 break; 749 if (m->rm_flags & RNF_NORMAL) { 750 mmask = m->rm_leaf->rn_mask; 751 if (tt->rn_flags & RNF_NORMAL) { 752 #if !defined(RADIX_MPATH) 753 log(LOG_ERR, 754 "Non-unique normal route, mask not entered\n"); 755 #endif 756 return tt; 757 } 758 } else 759 mmask = m->rm_mask; 760 if (mmask == netmask) { 761 m->rm_refs++; 762 tt->rn_mklist = m; 763 return tt; 764 } 765 if (rn_refines(netmask, mmask) 766 || rn_lexobetter(netmask, mmask)) 767 break; 768 } 769 *mp = rn_new_radix_mask(tt, *mp); 770 return tt; 771 } 772 773 struct radix_node * 774 rn_delete(v_arg, netmask_arg, head) 775 void *v_arg, *netmask_arg; 776 struct radix_node_head *head; 777 { 778 register struct radix_node *t, *p, *x, *tt; 779 struct radix_mask *m, *saved_m, **mp; 780 struct radix_node *dupedkey, *saved_tt, *top; 781 caddr_t v, netmask; 782 int b, head_off, vlen; 783 784 v = v_arg; 785 netmask = netmask_arg; 786 x = head->rnh_treetop; 787 tt = rn_search(v, x); 788 head_off = x->rn_offset; 789 vlen = LEN(v); 790 saved_tt = tt; 791 top = x; 792 if (tt == 0 || 793 bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off)) 794 return (0); 795 /* 796 * Delete our route from mask lists. 797 */ 798 if (netmask) { 799 x = rn_addmask(netmask, head->rnh_masks, 1, head_off); 800 if (x == NULL) 801 return (0); 802 netmask = x->rn_key; 803 while (tt->rn_mask != netmask) 804 if ((tt = tt->rn_dupedkey) == 0) 805 return (0); 806 } 807 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0) 808 goto on1; 809 if (tt->rn_flags & RNF_NORMAL) { 810 if (m->rm_leaf != tt || m->rm_refs > 0) { 811 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 812 return 0; /* dangling ref could cause disaster */ 813 } 814 } else { 815 if (m->rm_mask != tt->rn_mask) { 816 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 817 goto on1; 818 } 819 if (--m->rm_refs >= 0) 820 goto on1; 821 } 822 b = -1 - tt->rn_bit; 823 t = saved_tt->rn_parent; 824 if (b > t->rn_bit) 825 goto on1; /* Wasn't lifted at all */ 826 do { 827 x = t; 828 t = t->rn_parent; 829 } while (b <= t->rn_bit && x != top); 830 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 831 if (m == saved_m) { 832 *mp = m->rm_mklist; 833 Free(m); 834 break; 835 } 836 if (m == 0) { 837 log(LOG_ERR, "rn_delete: couldn't find our annotation\n"); 838 if (tt->rn_flags & RNF_NORMAL) 839 return (0); /* Dangling ref to us */ 840 } 841 on1: 842 /* 843 * Eliminate us from tree 844 */ 845 if (tt->rn_flags & RNF_ROOT) 846 return (0); 847 #ifdef RN_DEBUG 848 /* Get us out of the creation list */ 849 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {} 850 if (t) t->rn_ybro = tt->rn_ybro; 851 #endif 852 t = tt->rn_parent; 853 dupedkey = saved_tt->rn_dupedkey; 854 if (dupedkey) { 855 /* 856 * Here, tt is the deletion target and 857 * saved_tt is the head of the dupekey chain. 858 */ 859 if (tt == saved_tt) { 860 /* remove from head of chain */ 861 x = dupedkey; x->rn_parent = t; 862 if (t->rn_left == tt) 863 t->rn_left = x; 864 else 865 t->rn_right = x; 866 } else { 867 /* find node in front of tt on the chain */ 868 for (x = p = saved_tt; p && p->rn_dupedkey != tt;) 869 p = p->rn_dupedkey; 870 if (p) { 871 p->rn_dupedkey = tt->rn_dupedkey; 872 if (tt->rn_dupedkey) /* parent */ 873 tt->rn_dupedkey->rn_parent = p; 874 /* parent */ 875 } else log(LOG_ERR, "rn_delete: couldn't find us\n"); 876 } 877 t = tt + 1; 878 if (t->rn_flags & RNF_ACTIVE) { 879 #ifndef RN_DEBUG 880 *++x = *t; 881 p = t->rn_parent; 882 #else 883 b = t->rn_info; 884 *++x = *t; 885 t->rn_info = b; 886 p = t->rn_parent; 887 #endif 888 if (p->rn_left == t) 889 p->rn_left = x; 890 else 891 p->rn_right = x; 892 x->rn_left->rn_parent = x; 893 x->rn_right->rn_parent = x; 894 } 895 goto out; 896 } 897 if (t->rn_left == tt) 898 x = t->rn_right; 899 else 900 x = t->rn_left; 901 p = t->rn_parent; 902 if (p->rn_right == t) 903 p->rn_right = x; 904 else 905 p->rn_left = x; 906 x->rn_parent = p; 907 /* 908 * Demote routes attached to us. 909 */ 910 if (t->rn_mklist) { 911 if (x->rn_bit >= 0) { 912 for (mp = &x->rn_mklist; (m = *mp);) 913 mp = &m->rm_mklist; 914 *mp = t->rn_mklist; 915 } else { 916 /* If there are any key,mask pairs in a sibling 917 duped-key chain, some subset will appear sorted 918 in the same order attached to our mklist */ 919 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey) 920 if (m == x->rn_mklist) { 921 struct radix_mask *mm = m->rm_mklist; 922 x->rn_mklist = 0; 923 if (--(m->rm_refs) < 0) 924 Free(m); 925 m = mm; 926 } 927 if (m) 928 log(LOG_ERR, 929 "rn_delete: Orphaned Mask %p at %p\n", 930 m, x); 931 } 932 } 933 /* 934 * We may be holding an active internal node in the tree. 935 */ 936 x = tt + 1; 937 if (t != x) { 938 #ifndef RN_DEBUG 939 *t = *x; 940 #else 941 b = t->rn_info; 942 *t = *x; 943 t->rn_info = b; 944 #endif 945 t->rn_left->rn_parent = t; 946 t->rn_right->rn_parent = t; 947 p = x->rn_parent; 948 if (p->rn_left == x) 949 p->rn_left = t; 950 else 951 p->rn_right = t; 952 } 953 out: 954 tt->rn_flags &= ~RNF_ACTIVE; 955 tt[1].rn_flags &= ~RNF_ACTIVE; 956 return (tt); 957 } 958 959 /* 960 * This is the same as rn_walktree() except for the parameters and the 961 * exit. 962 */ 963 static int 964 rn_walktree_from(h, a, m, f, w) 965 struct radix_node_head *h; 966 void *a, *m; 967 walktree_f_t *f; 968 void *w; 969 { 970 int error; 971 struct radix_node *base, *next; 972 u_char *xa = (u_char *)a; 973 u_char *xm = (u_char *)m; 974 register struct radix_node *rn, *last = 0 /* shut up gcc */; 975 int stopping = 0; 976 int lastb; 977 978 /* 979 * rn_search_m is sort-of-open-coded here. We cannot use the 980 * function because we need to keep track of the last node seen. 981 */ 982 /* printf("about to search\n"); */ 983 for (rn = h->rnh_treetop; rn->rn_bit >= 0; ) { 984 last = rn; 985 /* printf("rn_bit %d, rn_bmask %x, xm[rn_offset] %x\n", 986 rn->rn_bit, rn->rn_bmask, xm[rn->rn_offset]); */ 987 if (!(rn->rn_bmask & xm[rn->rn_offset])) { 988 break; 989 } 990 if (rn->rn_bmask & xa[rn->rn_offset]) { 991 rn = rn->rn_right; 992 } else { 993 rn = rn->rn_left; 994 } 995 } 996 /* printf("done searching\n"); */ 997 998 /* 999 * Two cases: either we stepped off the end of our mask, 1000 * in which case last == rn, or we reached a leaf, in which 1001 * case we want to start from the last node we looked at. 1002 * Either way, last is the node we want to start from. 1003 */ 1004 rn = last; 1005 lastb = rn->rn_bit; 1006 1007 /* printf("rn %p, lastb %d\n", rn, lastb);*/ 1008 1009 /* 1010 * This gets complicated because we may delete the node 1011 * while applying the function f to it, so we need to calculate 1012 * the successor node in advance. 1013 */ 1014 while (rn->rn_bit >= 0) 1015 rn = rn->rn_left; 1016 1017 while (!stopping) { 1018 /* printf("node %p (%d)\n", rn, rn->rn_bit); */ 1019 base = rn; 1020 /* If at right child go back up, otherwise, go right */ 1021 while (rn->rn_parent->rn_right == rn 1022 && !(rn->rn_flags & RNF_ROOT)) { 1023 rn = rn->rn_parent; 1024 1025 /* if went up beyond last, stop */ 1026 if (rn->rn_bit <= lastb) { 1027 stopping = 1; 1028 /* printf("up too far\n"); */ 1029 /* 1030 * XXX we should jump to the 'Process leaves' 1031 * part, because the values of 'rn' and 'next' 1032 * we compute will not be used. Not a big deal 1033 * because this loop will terminate, but it is 1034 * inefficient and hard to understand! 1035 */ 1036 } 1037 } 1038 1039 /* 1040 * At the top of the tree, no need to traverse the right 1041 * half, prevent the traversal of the entire tree in the 1042 * case of default route. 1043 */ 1044 if (rn->rn_parent->rn_flags & RNF_ROOT) 1045 stopping = 1; 1046 1047 /* Find the next *leaf* since next node might vanish, too */ 1048 for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;) 1049 rn = rn->rn_left; 1050 next = rn; 1051 /* Process leaves */ 1052 while ((rn = base) != 0) { 1053 base = rn->rn_dupedkey; 1054 /* printf("leaf %p\n", rn); */ 1055 if (!(rn->rn_flags & RNF_ROOT) 1056 && (error = (*f)(rn, w))) 1057 return (error); 1058 } 1059 rn = next; 1060 1061 if (rn->rn_flags & RNF_ROOT) { 1062 /* printf("root, stopping"); */ 1063 stopping = 1; 1064 } 1065 1066 } 1067 return 0; 1068 } 1069 1070 static int 1071 rn_walktree(h, f, w) 1072 struct radix_node_head *h; 1073 walktree_f_t *f; 1074 void *w; 1075 { 1076 int error; 1077 struct radix_node *base, *next; 1078 register struct radix_node *rn = h->rnh_treetop; 1079 /* 1080 * This gets complicated because we may delete the node 1081 * while applying the function f to it, so we need to calculate 1082 * the successor node in advance. 1083 */ 1084 1085 /* First time through node, go left */ 1086 while (rn->rn_bit >= 0) 1087 rn = rn->rn_left; 1088 for (;;) { 1089 base = rn; 1090 /* If at right child go back up, otherwise, go right */ 1091 while (rn->rn_parent->rn_right == rn 1092 && (rn->rn_flags & RNF_ROOT) == 0) 1093 rn = rn->rn_parent; 1094 /* Find the next *leaf* since next node might vanish, too */ 1095 for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;) 1096 rn = rn->rn_left; 1097 next = rn; 1098 /* Process leaves */ 1099 while ((rn = base)) { 1100 base = rn->rn_dupedkey; 1101 if (!(rn->rn_flags & RNF_ROOT) 1102 && (error = (*f)(rn, w))) 1103 return (error); 1104 } 1105 rn = next; 1106 if (rn->rn_flags & RNF_ROOT) 1107 return (0); 1108 } 1109 /* NOTREACHED */ 1110 } 1111 1112 /* 1113 * Allocate and initialize an empty tree. This has 3 nodes, which are 1114 * part of the radix_node_head (in the order <left,root,right>) and are 1115 * marked RNF_ROOT so they cannot be freed. 1116 * The leaves have all-zero and all-one keys, with significant 1117 * bits starting at 'off'. 1118 * Return 1 on success, 0 on error. 1119 */ 1120 static int 1121 rn_inithead_internal(void **head, int off) 1122 { 1123 register struct radix_node_head *rnh; 1124 register struct radix_node *t, *tt, *ttt; 1125 if (*head) 1126 return (1); 1127 R_Zalloc(rnh, struct radix_node_head *, sizeof (*rnh)); 1128 if (rnh == 0) 1129 return (0); 1130 #ifdef _KERNEL 1131 RADIX_NODE_HEAD_LOCK_INIT(rnh); 1132 #endif 1133 *head = rnh; 1134 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes); 1135 ttt = rnh->rnh_nodes + 2; 1136 t->rn_right = ttt; 1137 t->rn_parent = t; 1138 tt = t->rn_left; /* ... which in turn is rnh->rnh_nodes */ 1139 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE; 1140 tt->rn_bit = -1 - off; 1141 *ttt = *tt; 1142 ttt->rn_key = rn_ones; 1143 rnh->rnh_addaddr = rn_addroute; 1144 rnh->rnh_deladdr = rn_delete; 1145 rnh->rnh_matchaddr = rn_match; 1146 rnh->rnh_lookup = rn_lookup; 1147 rnh->rnh_walktree = rn_walktree; 1148 rnh->rnh_walktree_from = rn_walktree_from; 1149 rnh->rnh_treetop = t; 1150 return (1); 1151 } 1152 1153 static void 1154 rn_detachhead_internal(void **head) 1155 { 1156 struct radix_node_head *rnh; 1157 1158 KASSERT((head != NULL && *head != NULL), 1159 ("%s: head already freed", __func__)); 1160 rnh = *head; 1161 1162 /* Free <left,root,right> nodes. */ 1163 Free(rnh); 1164 1165 *head = NULL; 1166 } 1167 1168 int 1169 rn_inithead(void **head, int off) 1170 { 1171 struct radix_node_head *rnh; 1172 1173 if (*head != NULL) 1174 return (1); 1175 1176 if (rn_inithead_internal(head, off) == 0) 1177 return (0); 1178 1179 rnh = (struct radix_node_head *)(*head); 1180 1181 if (rn_inithead_internal((void **)&rnh->rnh_masks, 0) == 0) { 1182 rn_detachhead_internal(head); 1183 return (0); 1184 } 1185 1186 return (1); 1187 } 1188 1189 int 1190 rn_detachhead(void **head) 1191 { 1192 struct radix_node_head *rnh; 1193 1194 KASSERT((head != NULL && *head != NULL), 1195 ("%s: head already freed", __func__)); 1196 1197 rnh = *head; 1198 1199 rn_detachhead_internal((void **)&rnh->rnh_masks); 1200 rn_detachhead_internal(head); 1201 return (1); 1202 } 1203 1204