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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 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)radix.c 8.5 (Berkeley) 5/19/95 34 * $FreeBSD: releng/5.2/sys/net/radix.c 120359 2003-09-22 23:24:18Z peter $ 35 */ 36 37 /* 38 * Routines to build and maintain radix trees for routing lookups. 39 */ 40 #ifndef _RADIX_H_ 41 #include <sys/param.h> 42 #ifdef _KERNEL 43 #include <sys/lock.h> 44 #include <sys/mutex.h> 45 #include <sys/systm.h> 46 #include <sys/malloc.h> 47 #include <sys/domain.h> 48 #else 49 #include <stdlib.h> 50 #endif 51 #include <sys/syslog.h> 52 #include <net/radix.h> 53 #endif 54 55 static int rn_walktree_from(struct radix_node_head *h, void *a, void *m, 56 walktree_f_t *f, void *w); 57 static int rn_walktree(struct radix_node_head *, walktree_f_t *, void *); 58 static struct radix_node 59 *rn_insert(void *, struct radix_node_head *, int *, 60 struct radix_node [2]), 61 *rn_newpair(void *, int, struct radix_node[2]), 62 *rn_search(void *, struct radix_node *), 63 *rn_search_m(void *, struct radix_node *, void *); 64 65 static int max_keylen; 66 static struct radix_mask *rn_mkfreelist; 67 static struct radix_node_head *mask_rnhead; 68 static char *addmask_key; 69 static char normal_chars[] = {0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1}; 70 static char *rn_zeros, *rn_ones; 71 72 #define rn_masktop (mask_rnhead->rnh_treetop) 73 #undef Bcmp 74 #define Bcmp(a, b, l) \ 75 ((l) == 0 ? 0 : bcmp((caddr_t)(a), (caddr_t)(b), (u_long)(l))) 76 77 static int rn_lexobetter(void *m_arg, void *n_arg); 78 static struct radix_mask * 79 rn_new_radix_mask(struct radix_node *tt, 80 struct radix_mask *next); 81 static int rn_satisfies_leaf(char *trial, struct radix_node *leaf, 82 int skip); 83 84 /* 85 * The data structure for the keys is a radix tree with one way 86 * branching removed. The index rn_bit at an internal node n represents a bit 87 * position to be tested. The tree is arranged so that all descendants 88 * of a node n have keys whose bits all agree up to position rn_bit - 1. 89 * (We say the index of n is rn_bit.) 90 * 91 * There is at least one descendant which has a one bit at position rn_bit, 92 * and at least one with a zero there. 93 * 94 * A route is determined by a pair of key and mask. We require that the 95 * bit-wise logical and of the key and mask to be the key. 96 * We define the index of a route to associated with the mask to be 97 * the first bit number in the mask where 0 occurs (with bit number 0 98 * representing the highest order bit). 99 * 100 * We say a mask is normal if every bit is 0, past the index of the mask. 101 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_bit, 102 * and m is a normal mask, then the route applies to every descendant of n. 103 * If the index(m) < rn_bit, this implies the trailing last few bits of k 104 * before bit b are all 0, (and hence consequently true of every descendant 105 * of n), so the route applies to all descendants of the node as well. 106 * 107 * Similar logic shows that a non-normal mask m such that 108 * index(m) <= index(n) could potentially apply to many children of n. 109 * Thus, for each non-host route, we attach its mask to a list at an internal 110 * node as high in the tree as we can go. 111 * 112 * The present version of the code makes use of normal routes in short- 113 * circuiting an explict mask and compare operation when testing whether 114 * a key satisfies a normal route, and also in remembering the unique leaf 115 * that governs a subtree. 116 */ 117 118 static struct radix_node * 119 rn_search(v_arg, head) 120 void *v_arg; 121 struct radix_node *head; 122 { 123 register struct radix_node *x; 124 register caddr_t v; 125 126 for (x = head, v = v_arg; x->rn_bit >= 0;) { 127 if (x->rn_bmask & v[x->rn_offset]) 128 x = x->rn_right; 129 else 130 x = x->rn_left; 131 } 132 return (x); 133 } 134 135 static struct radix_node * 136 rn_search_m(v_arg, head, m_arg) 137 struct radix_node *head; 138 void *v_arg, *m_arg; 139 { 140 register struct radix_node *x; 141 register caddr_t v = v_arg, m = m_arg; 142 143 for (x = head; x->rn_bit >= 0;) { 144 if ((x->rn_bmask & m[x->rn_offset]) && 145 (x->rn_bmask & v[x->rn_offset])) 146 x = x->rn_right; 147 else 148 x = x->rn_left; 149 } 150 return x; 151 } 152 153 int 154 rn_refines(m_arg, n_arg) 155 void *m_arg, *n_arg; 156 { 157 register caddr_t m = m_arg, n = n_arg; 158 register caddr_t lim, lim2 = lim = n + *(u_char *)n; 159 int longer = (*(u_char *)n++) - (int)(*(u_char *)m++); 160 int masks_are_equal = 1; 161 162 if (longer > 0) 163 lim -= longer; 164 while (n < lim) { 165 if (*n & ~(*m)) 166 return 0; 167 if (*n++ != *m++) 168 masks_are_equal = 0; 169 } 170 while (n < lim2) 171 if (*n++) 172 return 0; 173 if (masks_are_equal && (longer < 0)) 174 for (lim2 = m - longer; m < lim2; ) 175 if (*m++) 176 return 1; 177 return (!masks_are_equal); 178 } 179 180 struct radix_node * 181 rn_lookup(v_arg, m_arg, head) 182 void *v_arg, *m_arg; 183 struct radix_node_head *head; 184 { 185 register struct radix_node *x; 186 caddr_t netmask = 0; 187 188 if (m_arg) { 189 x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_offset); 190 if (x == 0) 191 return (0); 192 netmask = x->rn_key; 193 } 194 x = rn_match(v_arg, head); 195 if (x && netmask) { 196 while (x && x->rn_mask != netmask) 197 x = x->rn_dupedkey; 198 } 199 return x; 200 } 201 202 static int 203 rn_satisfies_leaf(trial, leaf, skip) 204 char *trial; 205 register struct radix_node *leaf; 206 int skip; 207 { 208 register char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask; 209 char *cplim; 210 int length = min(*(u_char *)cp, *(u_char *)cp2); 211 212 if (cp3 == 0) 213 cp3 = rn_ones; 214 else 215 length = min(length, *(u_char *)cp3); 216 cplim = cp + length; cp3 += skip; cp2 += skip; 217 for (cp += skip; cp < cplim; cp++, cp2++, cp3++) 218 if ((*cp ^ *cp2) & *cp3) 219 return 0; 220 return 1; 221 } 222 223 struct radix_node * 224 rn_match(v_arg, head) 225 void *v_arg; 226 struct radix_node_head *head; 227 { 228 caddr_t v = v_arg; 229 register struct radix_node *t = head->rnh_treetop, *x; 230 register caddr_t cp = v, cp2; 231 caddr_t cplim; 232 struct radix_node *saved_t, *top = t; 233 int off = t->rn_offset, vlen = *(u_char *)cp, matched_off; 234 register int test, b, rn_bit; 235 236 /* 237 * Open code rn_search(v, top) to avoid overhead of extra 238 * subroutine call. 239 */ 240 for (; t->rn_bit >= 0; ) { 241 if (t->rn_bmask & cp[t->rn_offset]) 242 t = t->rn_right; 243 else 244 t = t->rn_left; 245 } 246 /* 247 * See if we match exactly as a host destination 248 * or at least learn how many bits match, for normal mask finesse. 249 * 250 * It doesn't hurt us to limit how many bytes to check 251 * to the length of the mask, since if it matches we had a genuine 252 * match and the leaf we have is the most specific one anyway; 253 * if it didn't match with a shorter length it would fail 254 * with a long one. This wins big for class B&C netmasks which 255 * are probably the most common case... 256 */ 257 if (t->rn_mask) 258 vlen = *(u_char *)t->rn_mask; 259 cp += off; cp2 = t->rn_key + off; cplim = v + vlen; 260 for (; cp < cplim; cp++, cp2++) 261 if (*cp != *cp2) 262 goto on1; 263 /* 264 * This extra grot is in case we are explicitly asked 265 * to look up the default. Ugh! 266 * 267 * Never return the root node itself, it seems to cause a 268 * lot of confusion. 269 */ 270 if (t->rn_flags & RNF_ROOT) 271 t = t->rn_dupedkey; 272 return t; 273 on1: 274 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */ 275 for (b = 7; (test >>= 1) > 0;) 276 b--; 277 matched_off = cp - v; 278 b += matched_off << 3; 279 rn_bit = -1 - b; 280 /* 281 * If there is a host route in a duped-key chain, it will be first. 282 */ 283 if ((saved_t = t)->rn_mask == 0) 284 t = t->rn_dupedkey; 285 for (; t; t = t->rn_dupedkey) 286 /* 287 * Even if we don't match exactly as a host, 288 * we may match if the leaf we wound up at is 289 * a route to a net. 290 */ 291 if (t->rn_flags & RNF_NORMAL) { 292 if (rn_bit <= t->rn_bit) 293 return t; 294 } else if (rn_satisfies_leaf(v, t, matched_off)) 295 return t; 296 t = saved_t; 297 /* start searching up the tree */ 298 do { 299 register struct radix_mask *m; 300 t = t->rn_parent; 301 m = t->rn_mklist; 302 /* 303 * If non-contiguous masks ever become important 304 * we can restore the masking and open coding of 305 * the search and satisfaction test and put the 306 * calculation of "off" back before the "do". 307 */ 308 while (m) { 309 if (m->rm_flags & RNF_NORMAL) { 310 if (rn_bit <= m->rm_bit) 311 return (m->rm_leaf); 312 } else { 313 off = min(t->rn_offset, matched_off); 314 x = rn_search_m(v, t, m->rm_mask); 315 while (x && x->rn_mask != m->rm_mask) 316 x = x->rn_dupedkey; 317 if (x && rn_satisfies_leaf(v, x, off)) 318 return x; 319 } 320 m = m->rm_mklist; 321 } 322 } while (t != top); 323 return 0; 324 } 325 326 #ifdef RN_DEBUG 327 int rn_nodenum; 328 struct radix_node *rn_clist; 329 int rn_saveinfo; 330 int rn_debug = 1; 331 #endif 332 333 static struct radix_node * 334 rn_newpair(v, b, nodes) 335 void *v; 336 int b; 337 struct radix_node nodes[2]; 338 { 339 register struct radix_node *tt = nodes, *t = tt + 1; 340 t->rn_bit = b; 341 t->rn_bmask = 0x80 >> (b & 7); 342 t->rn_left = tt; 343 t->rn_offset = b >> 3; 344 tt->rn_bit = -1; 345 tt->rn_key = (caddr_t)v; 346 tt->rn_parent = t; 347 tt->rn_flags = t->rn_flags = RNF_ACTIVE; 348 tt->rn_mklist = t->rn_mklist = 0; 349 #ifdef RN_DEBUG 350 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 351 tt->rn_twin = t; 352 tt->rn_ybro = rn_clist; 353 rn_clist = tt; 354 #endif 355 return t; 356 } 357 358 static struct radix_node * 359 rn_insert(v_arg, head, dupentry, nodes) 360 void *v_arg; 361 struct radix_node_head *head; 362 int *dupentry; 363 struct radix_node nodes[2]; 364 { 365 caddr_t v = v_arg; 366 struct radix_node *top = head->rnh_treetop; 367 int head_off = top->rn_offset, vlen = (int)*((u_char *)v); 368 register struct radix_node *t = rn_search(v_arg, top); 369 register caddr_t cp = v + head_off; 370 register int b; 371 struct radix_node *tt; 372 /* 373 * Find first bit at which v and t->rn_key differ 374 */ 375 { 376 register caddr_t cp2 = t->rn_key + head_off; 377 register int cmp_res; 378 caddr_t cplim = v + vlen; 379 380 while (cp < cplim) 381 if (*cp2++ != *cp++) 382 goto on1; 383 *dupentry = 1; 384 return t; 385 on1: 386 *dupentry = 0; 387 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff; 388 for (b = (cp - v) << 3; cmp_res; b--) 389 cmp_res >>= 1; 390 } 391 { 392 register struct radix_node *p, *x = top; 393 cp = v; 394 do { 395 p = x; 396 if (cp[x->rn_offset] & x->rn_bmask) 397 x = x->rn_right; 398 else 399 x = x->rn_left; 400 } while (b > (unsigned) x->rn_bit); 401 /* x->rn_bit < b && x->rn_bit >= 0 */ 402 #ifdef RN_DEBUG 403 if (rn_debug) 404 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p); 405 #endif 406 t = rn_newpair(v_arg, b, nodes); 407 tt = t->rn_left; 408 if ((cp[p->rn_offset] & p->rn_bmask) == 0) 409 p->rn_left = t; 410 else 411 p->rn_right = t; 412 x->rn_parent = t; 413 t->rn_parent = p; /* frees x, p as temp vars below */ 414 if ((cp[t->rn_offset] & t->rn_bmask) == 0) { 415 t->rn_right = x; 416 } else { 417 t->rn_right = tt; 418 t->rn_left = x; 419 } 420 #ifdef RN_DEBUG 421 if (rn_debug) 422 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p); 423 #endif 424 } 425 return (tt); 426 } 427 428 struct radix_node * 429 rn_addmask(n_arg, search, skip) 430 int search, skip; 431 void *n_arg; 432 { 433 caddr_t netmask = (caddr_t)n_arg; 434 register struct radix_node *x; 435 register caddr_t cp, cplim; 436 register int b = 0, mlen, j; 437 int maskduplicated, m0, isnormal; 438 struct radix_node *saved_x; 439 static int last_zeroed = 0; 440 441 if ((mlen = *(u_char *)netmask) > max_keylen) 442 mlen = max_keylen; 443 if (skip == 0) 444 skip = 1; 445 if (mlen <= skip) 446 return (mask_rnhead->rnh_nodes); 447 if (skip > 1) 448 Bcopy(rn_ones + 1, addmask_key + 1, skip - 1); 449 if ((m0 = mlen) > skip) 450 Bcopy(netmask + skip, addmask_key + skip, mlen - skip); 451 /* 452 * Trim trailing zeroes. 453 */ 454 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;) 455 cp--; 456 mlen = cp - addmask_key; 457 if (mlen <= skip) { 458 if (m0 >= last_zeroed) 459 last_zeroed = mlen; 460 return (mask_rnhead->rnh_nodes); 461 } 462 if (m0 < last_zeroed) 463 Bzero(addmask_key + m0, last_zeroed - m0); 464 *addmask_key = last_zeroed = mlen; 465 x = rn_search(addmask_key, rn_masktop); 466 if (Bcmp(addmask_key, x->rn_key, mlen) != 0) 467 x = 0; 468 if (x || search) 469 return (x); 470 R_Malloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x)); 471 if ((saved_x = x) == 0) 472 return (0); 473 Bzero(x, max_keylen + 2 * sizeof (*x)); 474 netmask = cp = (caddr_t)(x + 2); 475 Bcopy(addmask_key, cp, mlen); 476 x = rn_insert(cp, mask_rnhead, &maskduplicated, x); 477 if (maskduplicated) { 478 log(LOG_ERR, "rn_addmask: mask impossibly already in tree"); 479 Free(saved_x); 480 return (x); 481 } 482 /* 483 * Calculate index of mask, and check for normalcy. 484 */ 485 cplim = netmask + mlen; isnormal = 1; 486 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;) 487 cp++; 488 if (cp != cplim) { 489 for (j = 0x80; (j & *cp) != 0; j >>= 1) 490 b++; 491 if (*cp != normal_chars[b] || cp != (cplim - 1)) 492 isnormal = 0; 493 } 494 b += (cp - netmask) << 3; 495 x->rn_bit = -1 - b; 496 if (isnormal) 497 x->rn_flags |= RNF_NORMAL; 498 return (x); 499 } 500 501 static int /* XXX: arbitrary ordering for non-contiguous masks */ 502 rn_lexobetter(m_arg, n_arg) 503 void *m_arg, *n_arg; 504 { 505 register u_char *mp = m_arg, *np = n_arg, *lim; 506 507 if (*mp > *np) 508 return 1; /* not really, but need to check longer one first */ 509 if (*mp == *np) 510 for (lim = mp + *mp; mp < lim;) 511 if (*mp++ > *np++) 512 return 1; 513 return 0; 514 } 515 516 static struct radix_mask * 517 rn_new_radix_mask(tt, next) 518 register struct radix_node *tt; 519 register struct radix_mask *next; 520 { 521 register struct radix_mask *m; 522 523 MKGet(m); 524 if (m == 0) { 525 log(LOG_ERR, "Mask for route not entered\n"); 526 return (0); 527 } 528 Bzero(m, sizeof *m); 529 m->rm_bit = tt->rn_bit; 530 m->rm_flags = tt->rn_flags; 531 if (tt->rn_flags & RNF_NORMAL) 532 m->rm_leaf = tt; 533 else 534 m->rm_mask = tt->rn_mask; 535 m->rm_mklist = next; 536 tt->rn_mklist = m; 537 return m; 538 } 539 540 struct radix_node * 541 rn_addroute(v_arg, n_arg, head, treenodes) 542 void *v_arg, *n_arg; 543 struct radix_node_head *head; 544 struct radix_node treenodes[2]; 545 { 546 caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg; 547 register struct radix_node *t, *x = 0, *tt; 548 struct radix_node *saved_tt, *top = head->rnh_treetop; 549 short b = 0, b_leaf = 0; 550 int keyduplicated; 551 caddr_t mmask; 552 struct radix_mask *m, **mp; 553 554 /* 555 * In dealing with non-contiguous masks, there may be 556 * many different routes which have the same mask. 557 * We will find it useful to have a unique pointer to 558 * the mask to speed avoiding duplicate references at 559 * nodes and possibly save time in calculating indices. 560 */ 561 if (netmask) { 562 if ((x = rn_addmask(netmask, 0, top->rn_offset)) == 0) 563 return (0); 564 b_leaf = x->rn_bit; 565 b = -1 - x->rn_bit; 566 netmask = x->rn_key; 567 } 568 /* 569 * Deal with duplicated keys: attach node to previous instance 570 */ 571 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes); 572 if (keyduplicated) { 573 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) { 574 if (tt->rn_mask == netmask) 575 return (0); 576 if (netmask == 0 || 577 (tt->rn_mask && 578 ((b_leaf < tt->rn_bit) /* index(netmask) > node */ 579 || rn_refines(netmask, tt->rn_mask) 580 || rn_lexobetter(netmask, tt->rn_mask)))) 581 break; 582 } 583 /* 584 * If the mask is not duplicated, we wouldn't 585 * find it among possible duplicate key entries 586 * anyway, so the above test doesn't hurt. 587 * 588 * We sort the masks for a duplicated key the same way as 589 * in a masklist -- most specific to least specific. 590 * This may require the unfortunate nuisance of relocating 591 * the head of the list. 592 * 593 * We also reverse, or doubly link the list through the 594 * parent pointer. 595 */ 596 if (tt == saved_tt) { 597 struct radix_node *xx = x; 598 /* link in at head of list */ 599 (tt = treenodes)->rn_dupedkey = t; 600 tt->rn_flags = t->rn_flags; 601 tt->rn_parent = x = t->rn_parent; 602 t->rn_parent = tt; /* parent */ 603 if (x->rn_left == t) 604 x->rn_left = tt; 605 else 606 x->rn_right = tt; 607 saved_tt = tt; x = xx; 608 } else { 609 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey; 610 t->rn_dupedkey = tt; 611 tt->rn_parent = t; /* parent */ 612 if (tt->rn_dupedkey) /* parent */ 613 tt->rn_dupedkey->rn_parent = tt; /* parent */ 614 } 615 #ifdef RN_DEBUG 616 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 617 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 618 #endif 619 tt->rn_key = (caddr_t) v; 620 tt->rn_bit = -1; 621 tt->rn_flags = RNF_ACTIVE; 622 } 623 /* 624 * Put mask in tree. 625 */ 626 if (netmask) { 627 tt->rn_mask = netmask; 628 tt->rn_bit = x->rn_bit; 629 tt->rn_flags |= x->rn_flags & RNF_NORMAL; 630 } 631 t = saved_tt->rn_parent; 632 if (keyduplicated) 633 goto on2; 634 b_leaf = -1 - t->rn_bit; 635 if (t->rn_right == saved_tt) 636 x = t->rn_left; 637 else 638 x = t->rn_right; 639 /* Promote general routes from below */ 640 if (x->rn_bit < 0) { 641 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey) 642 if (x->rn_mask && (x->rn_bit >= b_leaf) && x->rn_mklist == 0) { 643 *mp = m = rn_new_radix_mask(x, 0); 644 if (m) 645 mp = &m->rm_mklist; 646 } 647 } else if (x->rn_mklist) { 648 /* 649 * Skip over masks whose index is > that of new node 650 */ 651 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 652 if (m->rm_bit >= b_leaf) 653 break; 654 t->rn_mklist = m; *mp = 0; 655 } 656 on2: 657 /* Add new route to highest possible ancestor's list */ 658 if ((netmask == 0) || (b > t->rn_bit )) 659 return tt; /* can't lift at all */ 660 b_leaf = tt->rn_bit; 661 do { 662 x = t; 663 t = t->rn_parent; 664 } while (b <= t->rn_bit && x != top); 665 /* 666 * Search through routes associated with node to 667 * insert new route according to index. 668 * Need same criteria as when sorting dupedkeys to avoid 669 * double loop on deletion. 670 */ 671 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) { 672 if (m->rm_bit < b_leaf) 673 continue; 674 if (m->rm_bit > b_leaf) 675 break; 676 if (m->rm_flags & RNF_NORMAL) { 677 mmask = m->rm_leaf->rn_mask; 678 if (tt->rn_flags & RNF_NORMAL) { 679 log(LOG_ERR, 680 "Non-unique normal route, mask not entered\n"); 681 return tt; 682 } 683 } else 684 mmask = m->rm_mask; 685 if (mmask == netmask) { 686 m->rm_refs++; 687 tt->rn_mklist = m; 688 return tt; 689 } 690 if (rn_refines(netmask, mmask) 691 || rn_lexobetter(netmask, mmask)) 692 break; 693 } 694 *mp = rn_new_radix_mask(tt, *mp); 695 return tt; 696 } 697 698 struct radix_node * 699 rn_delete(v_arg, netmask_arg, head) 700 void *v_arg, *netmask_arg; 701 struct radix_node_head *head; 702 { 703 register struct radix_node *t, *p, *x, *tt; 704 struct radix_mask *m, *saved_m, **mp; 705 struct radix_node *dupedkey, *saved_tt, *top; 706 caddr_t v, netmask; 707 int b, head_off, vlen; 708 709 v = v_arg; 710 netmask = netmask_arg; 711 x = head->rnh_treetop; 712 tt = rn_search(v, x); 713 head_off = x->rn_offset; 714 vlen = *(u_char *)v; 715 saved_tt = tt; 716 top = x; 717 if (tt == 0 || 718 Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off)) 719 return (0); 720 /* 721 * Delete our route from mask lists. 722 */ 723 if (netmask) { 724 if ((x = rn_addmask(netmask, 1, head_off)) == 0) 725 return (0); 726 netmask = x->rn_key; 727 while (tt->rn_mask != netmask) 728 if ((tt = tt->rn_dupedkey) == 0) 729 return (0); 730 } 731 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0) 732 goto on1; 733 if (tt->rn_flags & RNF_NORMAL) { 734 if (m->rm_leaf != tt || m->rm_refs > 0) { 735 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 736 return 0; /* dangling ref could cause disaster */ 737 } 738 } else { 739 if (m->rm_mask != tt->rn_mask) { 740 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 741 goto on1; 742 } 743 if (--m->rm_refs >= 0) 744 goto on1; 745 } 746 b = -1 - tt->rn_bit; 747 t = saved_tt->rn_parent; 748 if (b > t->rn_bit) 749 goto on1; /* Wasn't lifted at all */ 750 do { 751 x = t; 752 t = t->rn_parent; 753 } while (b <= t->rn_bit && x != top); 754 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 755 if (m == saved_m) { 756 *mp = m->rm_mklist; 757 MKFree(m); 758 break; 759 } 760 if (m == 0) { 761 log(LOG_ERR, "rn_delete: couldn't find our annotation\n"); 762 if (tt->rn_flags & RNF_NORMAL) 763 return (0); /* Dangling ref to us */ 764 } 765 on1: 766 /* 767 * Eliminate us from tree 768 */ 769 if (tt->rn_flags & RNF_ROOT) 770 return (0); 771 #ifdef RN_DEBUG 772 /* Get us out of the creation list */ 773 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {} 774 if (t) t->rn_ybro = tt->rn_ybro; 775 #endif 776 t = tt->rn_parent; 777 dupedkey = saved_tt->rn_dupedkey; 778 if (dupedkey) { 779 /* 780 * Here, tt is the deletion target and 781 * saved_tt is the head of the dupekey chain. 782 */ 783 if (tt == saved_tt) { 784 /* remove from head of chain */ 785 x = dupedkey; x->rn_parent = t; 786 if (t->rn_left == tt) 787 t->rn_left = x; 788 else 789 t->rn_right = x; 790 } else { 791 /* find node in front of tt on the chain */ 792 for (x = p = saved_tt; p && p->rn_dupedkey != tt;) 793 p = p->rn_dupedkey; 794 if (p) { 795 p->rn_dupedkey = tt->rn_dupedkey; 796 if (tt->rn_dupedkey) /* parent */ 797 tt->rn_dupedkey->rn_parent = p; 798 /* parent */ 799 } else log(LOG_ERR, "rn_delete: couldn't find us\n"); 800 } 801 t = tt + 1; 802 if (t->rn_flags & RNF_ACTIVE) { 803 #ifndef RN_DEBUG 804 *++x = *t; 805 p = t->rn_parent; 806 #else 807 b = t->rn_info; 808 *++x = *t; 809 t->rn_info = b; 810 p = t->rn_parent; 811 #endif 812 if (p->rn_left == t) 813 p->rn_left = x; 814 else 815 p->rn_right = x; 816 x->rn_left->rn_parent = x; 817 x->rn_right->rn_parent = x; 818 } 819 goto out; 820 } 821 if (t->rn_left == tt) 822 x = t->rn_right; 823 else 824 x = t->rn_left; 825 p = t->rn_parent; 826 if (p->rn_right == t) 827 p->rn_right = x; 828 else 829 p->rn_left = x; 830 x->rn_parent = p; 831 /* 832 * Demote routes attached to us. 833 */ 834 if (t->rn_mklist) { 835 if (x->rn_bit >= 0) { 836 for (mp = &x->rn_mklist; (m = *mp);) 837 mp = &m->rm_mklist; 838 *mp = t->rn_mklist; 839 } else { 840 /* If there are any key,mask pairs in a sibling 841 duped-key chain, some subset will appear sorted 842 in the same order attached to our mklist */ 843 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey) 844 if (m == x->rn_mklist) { 845 struct radix_mask *mm = m->rm_mklist; 846 x->rn_mklist = 0; 847 if (--(m->rm_refs) < 0) 848 MKFree(m); 849 m = mm; 850 } 851 if (m) 852 log(LOG_ERR, 853 "rn_delete: Orphaned Mask %p at %p\n", 854 (void *)m, (void *)x); 855 } 856 } 857 /* 858 * We may be holding an active internal node in the tree. 859 */ 860 x = tt + 1; 861 if (t != x) { 862 #ifndef RN_DEBUG 863 *t = *x; 864 #else 865 b = t->rn_info; 866 *t = *x; 867 t->rn_info = b; 868 #endif 869 t->rn_left->rn_parent = t; 870 t->rn_right->rn_parent = t; 871 p = x->rn_parent; 872 if (p->rn_left == x) 873 p->rn_left = t; 874 else 875 p->rn_right = t; 876 } 877 out: 878 tt->rn_flags &= ~RNF_ACTIVE; 879 tt[1].rn_flags &= ~RNF_ACTIVE; 880 return (tt); 881 } 882 883 /* 884 * This is the same as rn_walktree() except for the parameters and the 885 * exit. 886 */ 887 static int 888 rn_walktree_from(h, a, m, f, w) 889 struct radix_node_head *h; 890 void *a, *m; 891 walktree_f_t *f; 892 void *w; 893 { 894 int error; 895 struct radix_node *base, *next; 896 u_char *xa = (u_char *)a; 897 u_char *xm = (u_char *)m; 898 register struct radix_node *rn, *last = 0 /* shut up gcc */; 899 int stopping = 0; 900 int lastb; 901 902 /* 903 * rn_search_m is sort-of-open-coded here. 904 */ 905 /* printf("about to search\n"); */ 906 for (rn = h->rnh_treetop; rn->rn_bit >= 0; ) { 907 last = rn; 908 /* printf("rn_bit %d, rn_bmask %x, xm[rn_offset] %x\n", 909 rn->rn_bit, rn->rn_bmask, xm[rn->rn_offset]); */ 910 if (!(rn->rn_bmask & xm[rn->rn_offset])) { 911 break; 912 } 913 if (rn->rn_bmask & xa[rn->rn_offset]) { 914 rn = rn->rn_right; 915 } else { 916 rn = rn->rn_left; 917 } 918 } 919 /* printf("done searching\n"); */ 920 921 /* 922 * Two cases: either we stepped off the end of our mask, 923 * in which case last == rn, or we reached a leaf, in which 924 * case we want to start from the last node we looked at. 925 * Either way, last is the node we want to start from. 926 */ 927 rn = last; 928 lastb = rn->rn_bit; 929 930 /* printf("rn %p, lastb %d\n", rn, lastb);*/ 931 932 /* 933 * This gets complicated because we may delete the node 934 * while applying the function f to it, so we need to calculate 935 * the successor node in advance. 936 */ 937 while (rn->rn_bit >= 0) 938 rn = rn->rn_left; 939 940 while (!stopping) { 941 /* printf("node %p (%d)\n", rn, rn->rn_bit); */ 942 base = rn; 943 /* If at right child go back up, otherwise, go right */ 944 while (rn->rn_parent->rn_right == rn 945 && !(rn->rn_flags & RNF_ROOT)) { 946 rn = rn->rn_parent; 947 948 /* if went up beyond last, stop */ 949 if (rn->rn_bit < lastb) { 950 stopping = 1; 951 /* printf("up too far\n"); */ 952 } 953 } 954 955 /* Find the next *leaf* since next node might vanish, too */ 956 for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;) 957 rn = rn->rn_left; 958 next = rn; 959 /* Process leaves */ 960 while ((rn = base) != 0) { 961 base = rn->rn_dupedkey; 962 /* printf("leaf %p\n", rn); */ 963 if (!(rn->rn_flags & RNF_ROOT) 964 && (error = (*f)(rn, w))) 965 return (error); 966 } 967 rn = next; 968 969 if (rn->rn_flags & RNF_ROOT) { 970 /* printf("root, stopping"); */ 971 stopping = 1; 972 } 973 974 } 975 return 0; 976 } 977 978 static int 979 rn_walktree(h, f, w) 980 struct radix_node_head *h; 981 walktree_f_t *f; 982 void *w; 983 { 984 int error; 985 struct radix_node *base, *next; 986 register struct radix_node *rn = h->rnh_treetop; 987 /* 988 * This gets complicated because we may delete the node 989 * while applying the function f to it, so we need to calculate 990 * the successor node in advance. 991 */ 992 /* First time through node, go left */ 993 while (rn->rn_bit >= 0) 994 rn = rn->rn_left; 995 for (;;) { 996 base = rn; 997 /* If at right child go back up, otherwise, go right */ 998 while (rn->rn_parent->rn_right == rn 999 && (rn->rn_flags & RNF_ROOT) == 0) 1000 rn = rn->rn_parent; 1001 /* Find the next *leaf* since next node might vanish, too */ 1002 for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;) 1003 rn = rn->rn_left; 1004 next = rn; 1005 /* Process leaves */ 1006 while ((rn = base)) { 1007 base = rn->rn_dupedkey; 1008 if (!(rn->rn_flags & RNF_ROOT) 1009 && (error = (*f)(rn, w))) 1010 return (error); 1011 } 1012 rn = next; 1013 if (rn->rn_flags & RNF_ROOT) 1014 return (0); 1015 } 1016 /* NOTREACHED */ 1017 } 1018 1019 int 1020 rn_inithead(head, off) 1021 void **head; 1022 int off; 1023 { 1024 register struct radix_node_head *rnh; 1025 register struct radix_node *t, *tt, *ttt; 1026 if (*head) 1027 return (1); 1028 R_Malloc(rnh, struct radix_node_head *, sizeof (*rnh)); 1029 if (rnh == 0) 1030 return (0); 1031 Bzero(rnh, sizeof (*rnh)); 1032 #ifdef _KERNEL 1033 RADIX_NODE_HEAD_LOCK_INIT(rnh); 1034 #endif 1035 *head = rnh; 1036 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes); 1037 ttt = rnh->rnh_nodes + 2; 1038 t->rn_right = ttt; 1039 t->rn_parent = t; 1040 tt = t->rn_left; 1041 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE; 1042 tt->rn_bit = -1 - off; 1043 *ttt = *tt; 1044 ttt->rn_key = rn_ones; 1045 rnh->rnh_addaddr = rn_addroute; 1046 rnh->rnh_deladdr = rn_delete; 1047 rnh->rnh_matchaddr = rn_match; 1048 rnh->rnh_lookup = rn_lookup; 1049 rnh->rnh_walktree = rn_walktree; 1050 rnh->rnh_walktree_from = rn_walktree_from; 1051 rnh->rnh_treetop = t; 1052 return (1); 1053 } 1054 1055 void 1056 rn_init() 1057 { 1058 char *cp, *cplim; 1059 #ifdef _KERNEL 1060 struct domain *dom; 1061 1062 for (dom = domains; dom; dom = dom->dom_next) 1063 if (dom->dom_maxrtkey > max_keylen) 1064 max_keylen = dom->dom_maxrtkey; 1065 #endif 1066 if (max_keylen == 0) { 1067 log(LOG_ERR, 1068 "rn_init: radix functions require max_keylen be set\n"); 1069 return; 1070 } 1071 R_Malloc(rn_zeros, char *, 3 * max_keylen); 1072 if (rn_zeros == NULL) 1073 panic("rn_init"); 1074 Bzero(rn_zeros, 3 * max_keylen); 1075 rn_ones = cp = rn_zeros + max_keylen; 1076 addmask_key = cplim = rn_ones + max_keylen; 1077 while (cp < cplim) 1078 *cp++ = -1; 1079 if (rn_inithead((void **)(void *)&mask_rnhead, 0) == 0) 1080 panic("rn_init 2"); 1081 }
Cache object: 80409da3e5d2264929e3dd6b76b1861d
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