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sys/net/radix.c
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1 /* $NetBSD: radix.c,v 1.31 2006/02/25 00:58:35 wiz Exp $ */ 2 3 /* 4 * Copyright (c) 1988, 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)radix.c 8.6 (Berkeley) 10/17/95 32 */ 33 34 /* 35 * Routines to build and maintain radix trees for routing lookups. 36 */ 37 38 #include <sys/cdefs.h> 39 __KERNEL_RCSID(0, "$NetBSD: radix.c,v 1.31 2006/02/25 00:58:35 wiz Exp $"); 40 41 #ifndef _NET_RADIX_H_ 42 #include <sys/param.h> 43 #ifdef _KERNEL 44 #include "opt_inet.h" 45 46 #include <sys/systm.h> 47 #include <sys/malloc.h> 48 #define M_DONTWAIT M_NOWAIT 49 #include <sys/domain.h> 50 #include <netinet/ip_encap.h> 51 #else 52 #include <stdlib.h> 53 #endif 54 #include <sys/syslog.h> 55 #include <net/radix.h> 56 #endif 57 58 int max_keylen; 59 struct radix_mask *rn_mkfreelist; 60 struct radix_node_head *mask_rnhead; 61 static char *addmask_key; 62 static const char normal_chars[] = 63 {0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1}; 64 static char *rn_zeros, *rn_ones; 65 66 #define rn_masktop (mask_rnhead->rnh_treetop) 67 68 static int rn_satisfies_leaf(const char *, struct radix_node *, int); 69 static int rn_lexobetter(const void *, const void *); 70 static struct radix_mask *rn_new_radix_mask(struct radix_node *, 71 struct radix_mask *); 72 73 /* 74 * The data structure for the keys is a radix tree with one way 75 * branching removed. The index rn_b at an internal node n represents a bit 76 * position to be tested. The tree is arranged so that all descendants 77 * of a node n have keys whose bits all agree up to position rn_b - 1. 78 * (We say the index of n is rn_b.) 79 * 80 * There is at least one descendant which has a one bit at position rn_b, 81 * and at least one with a zero there. 82 * 83 * A route is determined by a pair of key and mask. We require that the 84 * bit-wise logical and of the key and mask to be the key. 85 * We define the index of a route to associated with the mask to be 86 * the first bit number in the mask where 0 occurs (with bit number 0 87 * representing the highest order bit). 88 * 89 * We say a mask is normal if every bit is 0, past the index of the mask. 90 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_b, 91 * and m is a normal mask, then the route applies to every descendant of n. 92 * If the index(m) < rn_b, this implies the trailing last few bits of k 93 * before bit b are all 0, (and hence consequently true of every descendant 94 * of n), so the route applies to all descendants of the node as well. 95 * 96 * Similar logic shows that a non-normal mask m such that 97 * index(m) <= index(n) could potentially apply to many children of n. 98 * Thus, for each non-host route, we attach its mask to a list at an internal 99 * node as high in the tree as we can go. 100 * 101 * The present version of the code makes use of normal routes in short- 102 * circuiting an explicit mask and compare operation when testing whether 103 * a key satisfies a normal route, and also in remembering the unique leaf 104 * that governs a subtree. 105 */ 106 107 struct radix_node * 108 rn_search( 109 const void *v_arg, 110 struct radix_node *head) 111 { 112 const u_char * const v = v_arg; 113 struct radix_node *x; 114 115 for (x = head; x->rn_b >= 0;) { 116 if (x->rn_bmask & v[x->rn_off]) 117 x = x->rn_r; 118 else 119 x = x->rn_l; 120 } 121 return (x); 122 } 123 124 struct radix_node * 125 rn_search_m( 126 const void *v_arg, 127 struct radix_node *head, 128 const void *m_arg) 129 { 130 struct radix_node *x; 131 const u_char * const v = v_arg; 132 const u_char * const m = m_arg; 133 134 for (x = head; x->rn_b >= 0;) { 135 if ((x->rn_bmask & m[x->rn_off]) && 136 (x->rn_bmask & v[x->rn_off])) 137 x = x->rn_r; 138 else 139 x = x->rn_l; 140 } 141 return x; 142 } 143 144 int 145 rn_refines( 146 const void *m_arg, 147 const void *n_arg) 148 { 149 const char *m = m_arg; 150 const char *n = n_arg; 151 const char *lim = n + *(const u_char *)n; 152 const char *lim2 = lim; 153 int longer = (*(const u_char *)n++) - (int)(*(const u_char *)m++); 154 int masks_are_equal = 1; 155 156 if (longer > 0) 157 lim -= longer; 158 while (n < lim) { 159 if (*n & ~(*m)) 160 return 0; 161 if (*n++ != *m++) 162 masks_are_equal = 0; 163 } 164 while (n < lim2) 165 if (*n++) 166 return 0; 167 if (masks_are_equal && (longer < 0)) 168 for (lim2 = m - longer; m < lim2; ) 169 if (*m++) 170 return 1; 171 return (!masks_are_equal); 172 } 173 174 struct radix_node * 175 rn_lookup( 176 const void *v_arg, 177 const void *m_arg, 178 struct radix_node_head *head) 179 { 180 struct radix_node *x; 181 const char *netmask = NULL; 182 183 if (m_arg) { 184 if ((x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_off)) == 0) 185 return (0); 186 netmask = x->rn_key; 187 } 188 x = rn_match(v_arg, head); 189 if (x && netmask) { 190 while (x && x->rn_mask != netmask) 191 x = x->rn_dupedkey; 192 } 193 return x; 194 } 195 196 static int 197 rn_satisfies_leaf( 198 const char *trial, 199 struct radix_node *leaf, 200 int skip) 201 { 202 const char *cp = trial; 203 const char *cp2 = leaf->rn_key; 204 const char *cp3 = leaf->rn_mask; 205 const char *cplim; 206 int length = min(*(const u_char *)cp, *(const u_char *)cp2); 207 208 if (cp3 == 0) 209 cp3 = rn_ones; 210 else 211 length = min(length, *(const u_char *)cp3); 212 cplim = cp + length; cp3 += skip; cp2 += skip; 213 for (cp += skip; cp < cplim; cp++, cp2++, cp3++) 214 if ((*cp ^ *cp2) & *cp3) 215 return 0; 216 return 1; 217 } 218 219 struct radix_node * 220 rn_match( 221 const void *v_arg, 222 struct radix_node_head *head) 223 { 224 const char * const v = v_arg; 225 struct radix_node *t = head->rnh_treetop; 226 struct radix_node *top = t; 227 struct radix_node *x; 228 struct radix_node *saved_t; 229 const char *cp = v; 230 const char *cp2; 231 const char *cplim; 232 int off = t->rn_off; 233 int vlen = *(const u_char *)cp; 234 int matched_off; 235 int test, b, rn_b; 236 237 /* 238 * Open code rn_search(v, top) to avoid overhead of extra 239 * subroutine call. 240 */ 241 for (; t->rn_b >= 0; ) { 242 if (t->rn_bmask & cp[t->rn_off]) 243 t = t->rn_r; 244 else 245 t = t->rn_l; 246 } 247 /* 248 * See if we match exactly as a host destination 249 * or at least learn how many bits match, for normal mask finesse. 250 * 251 * It doesn't hurt us to limit how many bytes to check 252 * to the length of the mask, since if it matches we had a genuine 253 * match and the leaf we have is the most specific one anyway; 254 * if it didn't match with a shorter length it would fail 255 * with a long one. This wins big for class B&C netmasks which 256 * are probably the most common case... 257 */ 258 if (t->rn_mask) 259 vlen = *(const u_char *)t->rn_mask; 260 cp += off; cp2 = t->rn_key + off; cplim = v + vlen; 261 for (; cp < cplim; cp++, cp2++) 262 if (*cp != *cp2) 263 goto on1; 264 /* 265 * This extra grot is in case we are explicitly asked 266 * to look up the default. Ugh! 267 */ 268 if ((t->rn_flags & RNF_ROOT) && t->rn_dupedkey) 269 t = t->rn_dupedkey; 270 return t; 271 on1: 272 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */ 273 for (b = 7; (test >>= 1) > 0;) 274 b--; 275 matched_off = cp - v; 276 b += matched_off << 3; 277 rn_b = -1 - b; 278 /* 279 * If there is a host route in a duped-key chain, it will be first. 280 */ 281 if ((saved_t = t)->rn_mask == 0) 282 t = t->rn_dupedkey; 283 for (; t; t = t->rn_dupedkey) 284 /* 285 * Even if we don't match exactly as a host, 286 * we may match if the leaf we wound up at is 287 * a route to a net. 288 */ 289 if (t->rn_flags & RNF_NORMAL) { 290 if (rn_b <= t->rn_b) 291 return t; 292 } else if (rn_satisfies_leaf(v, t, matched_off)) 293 return t; 294 t = saved_t; 295 /* start searching up the tree */ 296 do { 297 struct radix_mask *m; 298 t = t->rn_p; 299 m = t->rn_mklist; 300 if (m) { 301 /* 302 * If non-contiguous masks ever become important 303 * we can restore the masking and open coding of 304 * the search and satisfaction test and put the 305 * calculation of "off" back before the "do". 306 */ 307 do { 308 if (m->rm_flags & RNF_NORMAL) { 309 if (rn_b <= m->rm_b) 310 return (m->rm_leaf); 311 } else { 312 off = min(t->rn_off, matched_off); 313 x = rn_search_m(v, t, m->rm_mask); 314 while (x && x->rn_mask != m->rm_mask) 315 x = x->rn_dupedkey; 316 if (x && rn_satisfies_leaf(v, x, off)) 317 return x; 318 } 319 m = m->rm_mklist; 320 } while (m); 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 struct radix_node * 334 rn_newpair( 335 const void *v, 336 int b, 337 struct radix_node nodes[2]) 338 { 339 struct radix_node *tt = nodes; 340 struct radix_node *t = tt + 1; 341 t->rn_b = b; t->rn_bmask = 0x80 >> (b & 7); 342 t->rn_l = tt; t->rn_off = b >> 3; 343 tt->rn_b = -1; tt->rn_key = v; tt->rn_p = t; 344 tt->rn_flags = t->rn_flags = RNF_ACTIVE; 345 #ifdef RN_DEBUG 346 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 347 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 348 #endif 349 return t; 350 } 351 352 struct radix_node * 353 rn_insert( 354 const void *v_arg, 355 struct radix_node_head *head, 356 int *dupentry, 357 struct radix_node nodes[2]) 358 { 359 struct radix_node *top = head->rnh_treetop; 360 struct radix_node *t = rn_search(v_arg, top); 361 struct radix_node *tt; 362 const char *v = v_arg; 363 int head_off = top->rn_off; 364 int vlen = *((const u_char *)v); 365 const char *cp = v + head_off; 366 int b; 367 /* 368 * Find first bit at which v and t->rn_key differ 369 */ 370 { 371 const char *cp2 = t->rn_key + head_off; 372 const char *cplim = v + vlen; 373 int cmp_res; 374 375 while (cp < cplim) 376 if (*cp2++ != *cp++) 377 goto on1; 378 *dupentry = 1; 379 return t; 380 on1: 381 *dupentry = 0; 382 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff; 383 for (b = (cp - v) << 3; cmp_res; b--) 384 cmp_res >>= 1; 385 } 386 { 387 struct radix_node *p, *x = top; 388 cp = v; 389 do { 390 p = x; 391 if (cp[x->rn_off] & x->rn_bmask) 392 x = x->rn_r; 393 else x = x->rn_l; 394 } while (b > (unsigned) x->rn_b); /* x->rn_b < b && x->rn_b >= 0 */ 395 #ifdef RN_DEBUG 396 if (rn_debug) 397 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p); 398 #endif 399 t = rn_newpair(v_arg, b, nodes); tt = t->rn_l; 400 if ((cp[p->rn_off] & p->rn_bmask) == 0) 401 p->rn_l = t; 402 else 403 p->rn_r = t; 404 x->rn_p = t; t->rn_p = p; /* frees x, p as temp vars below */ 405 if ((cp[t->rn_off] & t->rn_bmask) == 0) { 406 t->rn_r = x; 407 } else { 408 t->rn_r = tt; t->rn_l = x; 409 } 410 #ifdef RN_DEBUG 411 if (rn_debug) 412 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p); 413 #endif 414 } 415 return (tt); 416 } 417 418 struct radix_node * 419 rn_addmask( 420 const void *n_arg, 421 int search, 422 int skip) 423 { 424 const char *netmask = n_arg; 425 const char *cp; 426 const char *cplim; 427 struct radix_node *x; 428 struct radix_node *saved_x; 429 int b = 0, mlen, j; 430 int maskduplicated, m0, isnormal; 431 static int last_zeroed = 0; 432 433 if ((mlen = *(const u_char *)netmask) > max_keylen) 434 mlen = max_keylen; 435 if (skip == 0) 436 skip = 1; 437 if (mlen <= skip) 438 return (mask_rnhead->rnh_nodes); 439 if (skip > 1) 440 Bcopy(rn_ones + 1, addmask_key + 1, skip - 1); 441 if ((m0 = mlen) > skip) 442 Bcopy(netmask + skip, addmask_key + skip, mlen - skip); 443 /* 444 * Trim trailing zeroes. 445 */ 446 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;) 447 cp--; 448 mlen = cp - addmask_key; 449 if (mlen <= skip) { 450 if (m0 >= last_zeroed) 451 last_zeroed = mlen; 452 return (mask_rnhead->rnh_nodes); 453 } 454 if (m0 < last_zeroed) 455 Bzero(addmask_key + m0, last_zeroed - m0); 456 *addmask_key = last_zeroed = mlen; 457 x = rn_search(addmask_key, rn_masktop); 458 if (Bcmp(addmask_key, x->rn_key, mlen) != 0) 459 x = 0; 460 if (x || search) 461 return (x); 462 R_Malloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x)); 463 if ((saved_x = x) == 0) 464 return (0); 465 Bzero(x, max_keylen + 2 * sizeof (*x)); 466 cp = netmask = (caddr_t)(x + 2); 467 Bcopy(addmask_key, (caddr_t)(x + 2), mlen); 468 x = rn_insert(cp, mask_rnhead, &maskduplicated, x); 469 if (maskduplicated) { 470 log(LOG_ERR, "rn_addmask: mask impossibly already in tree\n"); 471 Free(saved_x); 472 return (x); 473 } 474 /* 475 * Calculate index of mask, and check for normalcy. 476 */ 477 cplim = netmask + mlen; isnormal = 1; 478 for (cp = netmask + skip; (cp < cplim) && *(const u_char *)cp == 0xff;) 479 cp++; 480 if (cp != cplim) { 481 for (j = 0x80; (j & *cp) != 0; j >>= 1) 482 b++; 483 if (*cp != normal_chars[b] || cp != (cplim - 1)) 484 isnormal = 0; 485 } 486 b += (cp - netmask) << 3; 487 x->rn_b = -1 - b; 488 if (isnormal) 489 x->rn_flags |= RNF_NORMAL; 490 return (x); 491 } 492 493 static int /* XXX: arbitrary ordering for non-contiguous masks */ 494 rn_lexobetter( 495 const void *m_arg, 496 const void *n_arg) 497 { 498 const u_char *mp = m_arg; 499 const u_char *np = n_arg; 500 const u_char *lim; 501 502 if (*mp > *np) 503 return 1; /* not really, but need to check longer one first */ 504 if (*mp == *np) 505 for (lim = mp + *mp; mp < lim;) 506 if (*mp++ > *np++) 507 return 1; 508 return 0; 509 } 510 511 static struct radix_mask * 512 rn_new_radix_mask( 513 struct radix_node *tt, 514 struct radix_mask *next) 515 { 516 struct radix_mask *m; 517 518 MKGet(m); 519 if (m == 0) { 520 log(LOG_ERR, "Mask for route not entered\n"); 521 return (0); 522 } 523 Bzero(m, sizeof *m); 524 m->rm_b = tt->rn_b; 525 m->rm_flags = tt->rn_flags; 526 if (tt->rn_flags & RNF_NORMAL) 527 m->rm_leaf = tt; 528 else 529 m->rm_mask = tt->rn_mask; 530 m->rm_mklist = next; 531 tt->rn_mklist = m; 532 return m; 533 } 534 535 struct radix_node * 536 rn_addroute( 537 const void *v_arg, 538 const void *n_arg, 539 struct radix_node_head *head, 540 struct radix_node treenodes[2]) 541 { 542 const char *v = v_arg; 543 const char *netmask = n_arg; 544 struct radix_node *t; 545 struct radix_node *x = 0; 546 struct radix_node *tt; 547 struct radix_node *saved_tt; 548 struct radix_node *top = head->rnh_treetop; 549 short b = 0, b_leaf = 0; 550 int keyduplicated; 551 const char *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_off)) == 0) 563 return (0); 564 b_leaf = x->rn_b; 565 b = -1 - x->rn_b; 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_b) || /* 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_p = x = t->rn_p; 602 t->rn_p = tt; 603 if (x->rn_l == t) x->rn_l = tt; else x->rn_r = tt; 604 saved_tt = tt; x = xx; 605 } else { 606 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey; 607 t->rn_dupedkey = tt; 608 tt->rn_p = t; 609 if (tt->rn_dupedkey) 610 tt->rn_dupedkey->rn_p = tt; 611 } 612 #ifdef RN_DEBUG 613 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 614 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 615 #endif 616 tt->rn_key = __UNCONST(v); /*XXXUNCONST*/ 617 tt->rn_b = -1; 618 tt->rn_flags = RNF_ACTIVE; 619 } 620 /* 621 * Put mask in tree. 622 */ 623 if (netmask) { 624 tt->rn_mask = netmask; 625 tt->rn_b = x->rn_b; 626 tt->rn_flags |= x->rn_flags & RNF_NORMAL; 627 } 628 t = saved_tt->rn_p; 629 if (keyduplicated) 630 goto on2; 631 b_leaf = -1 - t->rn_b; 632 if (t->rn_r == saved_tt) x = t->rn_l; else x = t->rn_r; 633 /* Promote general routes from below */ 634 if (x->rn_b < 0) { 635 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey) 636 if (x->rn_mask && (x->rn_b >= b_leaf) && x->rn_mklist == 0) { 637 *mp = m = rn_new_radix_mask(x, 0); 638 if (m) 639 mp = &m->rm_mklist; 640 } 641 } else if (x->rn_mklist) { 642 /* 643 * Skip over masks whose index is > that of new node 644 */ 645 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 646 if (m->rm_b >= b_leaf) 647 break; 648 t->rn_mklist = m; *mp = 0; 649 } 650 on2: 651 /* Add new route to highest possible ancestor's list */ 652 if ((netmask == 0) || (b > t->rn_b )) 653 return tt; /* can't lift at all */ 654 b_leaf = tt->rn_b; 655 do { 656 x = t; 657 t = t->rn_p; 658 } while (b <= t->rn_b && x != top); 659 /* 660 * Search through routes associated with node to 661 * insert new route according to index. 662 * Need same criteria as when sorting dupedkeys to avoid 663 * double loop on deletion. 664 */ 665 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) { 666 if (m->rm_b < b_leaf) 667 continue; 668 if (m->rm_b > b_leaf) 669 break; 670 if (m->rm_flags & RNF_NORMAL) { 671 mmask = m->rm_leaf->rn_mask; 672 if (tt->rn_flags & RNF_NORMAL) { 673 log(LOG_ERR, "Non-unique normal route," 674 " mask not entered\n"); 675 return tt; 676 } 677 } else 678 mmask = m->rm_mask; 679 if (mmask == netmask) { 680 m->rm_refs++; 681 tt->rn_mklist = m; 682 return tt; 683 } 684 if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask)) 685 break; 686 } 687 *mp = rn_new_radix_mask(tt, *mp); 688 return tt; 689 } 690 691 struct radix_node * 692 rn_delete( 693 const void *v_arg, 694 const void *netmask_arg, 695 struct radix_node_head *head) 696 { 697 struct radix_node *t; 698 struct radix_node *p; 699 struct radix_node *x; 700 struct radix_node *tt; 701 struct radix_node *dupedkey; 702 struct radix_node *saved_tt; 703 struct radix_node *top; 704 struct radix_mask *m; 705 struct radix_mask *saved_m; 706 struct radix_mask **mp; 707 const char *v = v_arg; 708 const char *netmask = netmask_arg; 709 int b, head_off, vlen; 710 711 x = head->rnh_treetop; 712 tt = rn_search(v, x); 713 head_off = x->rn_off; 714 vlen = *(const 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_b; 747 t = saved_tt->rn_p; 748 if (b > t->rn_b) 749 goto on1; /* Wasn't lifted at all */ 750 do { 751 x = t; 752 t = t->rn_p; 753 } while (b <= t->rn_b && 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_p; 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 dupedkey chain. 782 */ 783 if (tt == saved_tt) { 784 x = dupedkey; x->rn_p = t; 785 if (t->rn_l == tt) t->rn_l = x; else t->rn_r = x; 786 } else { 787 /* find node in front of tt on the chain */ 788 for (x = p = saved_tt; p && p->rn_dupedkey != tt;) 789 p = p->rn_dupedkey; 790 if (p) { 791 p->rn_dupedkey = tt->rn_dupedkey; 792 if (tt->rn_dupedkey) 793 tt->rn_dupedkey->rn_p = p; 794 } else log(LOG_ERR, "rn_delete: couldn't find us\n"); 795 } 796 t = tt + 1; 797 if (t->rn_flags & RNF_ACTIVE) { 798 #ifndef RN_DEBUG 799 *++x = *t; p = t->rn_p; 800 #else 801 b = t->rn_info; *++x = *t; t->rn_info = b; p = t->rn_p; 802 #endif 803 if (p->rn_l == t) p->rn_l = x; else p->rn_r = x; 804 x->rn_l->rn_p = x; x->rn_r->rn_p = x; 805 } 806 goto out; 807 } 808 if (t->rn_l == tt) x = t->rn_r; else x = t->rn_l; 809 p = t->rn_p; 810 if (p->rn_r == t) p->rn_r = x; else p->rn_l = x; 811 x->rn_p = p; 812 /* 813 * Demote routes attached to us. 814 */ 815 if (t->rn_mklist) { 816 if (x->rn_b >= 0) { 817 for (mp = &x->rn_mklist; (m = *mp);) 818 mp = &m->rm_mklist; 819 *mp = t->rn_mklist; 820 } else { 821 /* If there are any key,mask pairs in a sibling 822 duped-key chain, some subset will appear sorted 823 in the same order attached to our mklist */ 824 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey) 825 if (m == x->rn_mklist) { 826 struct radix_mask *mm = m->rm_mklist; 827 x->rn_mklist = 0; 828 if (--(m->rm_refs) < 0) 829 MKFree(m); 830 m = mm; 831 } 832 if (m) 833 log(LOG_ERR, "%s %p at %p\n", 834 "rn_delete: Orphaned Mask", m, x); 835 } 836 } 837 /* 838 * We may be holding an active internal node in the tree. 839 */ 840 x = tt + 1; 841 if (t != x) { 842 #ifndef RN_DEBUG 843 *t = *x; 844 #else 845 b = t->rn_info; *t = *x; t->rn_info = b; 846 #endif 847 t->rn_l->rn_p = t; t->rn_r->rn_p = t; 848 p = x->rn_p; 849 if (p->rn_l == x) p->rn_l = t; else p->rn_r = t; 850 } 851 out: 852 tt->rn_flags &= ~RNF_ACTIVE; 853 tt[1].rn_flags &= ~RNF_ACTIVE; 854 return (tt); 855 } 856 857 int 858 rn_walktree( 859 struct radix_node_head *h, 860 int (*f)(struct radix_node *, void *), 861 void *w) 862 { 863 int error; 864 struct radix_node *base; 865 struct radix_node *next; 866 struct radix_node *rn = h->rnh_treetop; 867 /* 868 * This gets complicated because we may delete the node 869 * while applying the function f to it, so we need to calculate 870 * the successor node in advance. 871 */ 872 /* First time through node, go left */ 873 while (rn->rn_b >= 0) 874 rn = rn->rn_l; 875 for (;;) { 876 base = rn; 877 /* If at right child go back up, otherwise, go right */ 878 while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0) 879 rn = rn->rn_p; 880 /* Find the next *leaf* since next node might vanish, too */ 881 for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;) 882 rn = rn->rn_l; 883 next = rn; 884 /* Process leaves */ 885 while ((rn = base) != NULL) { 886 base = rn->rn_dupedkey; 887 if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w))) 888 return (error); 889 } 890 rn = next; 891 if (rn->rn_flags & RNF_ROOT) 892 return (0); 893 } 894 /* NOTREACHED */ 895 } 896 897 int 898 rn_inithead(head, off) 899 void **head; 900 int off; 901 { 902 struct radix_node_head *rnh; 903 904 if (*head) 905 return (1); 906 R_Malloc(rnh, struct radix_node_head *, sizeof (*rnh)); 907 if (rnh == 0) 908 return (0); 909 *head = rnh; 910 return rn_inithead0(rnh, off); 911 } 912 913 int 914 rn_inithead0(rnh, off) 915 struct radix_node_head *rnh; 916 int off; 917 { 918 struct radix_node *t; 919 struct radix_node *tt; 920 struct radix_node *ttt; 921 922 Bzero(rnh, sizeof (*rnh)); 923 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes); 924 ttt = rnh->rnh_nodes + 2; 925 t->rn_r = ttt; 926 t->rn_p = t; 927 tt = t->rn_l; 928 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE; 929 tt->rn_b = -1 - off; 930 *ttt = *tt; 931 ttt->rn_key = rn_ones; 932 rnh->rnh_addaddr = rn_addroute; 933 rnh->rnh_deladdr = rn_delete; 934 rnh->rnh_matchaddr = rn_match; 935 rnh->rnh_lookup = rn_lookup; 936 rnh->rnh_walktree = rn_walktree; 937 rnh->rnh_treetop = t; 938 return (1); 939 } 940 941 void 942 rn_init() 943 { 944 char *cp, *cplim; 945 #ifdef _KERNEL 946 static int initialized; 947 __link_set_decl(domains, struct domain); 948 struct domain *const *dpp; 949 950 if (initialized) 951 return; 952 initialized = 1; 953 954 __link_set_foreach(dpp, domains) { 955 if ((*dpp)->dom_maxrtkey > max_keylen) 956 max_keylen = (*dpp)->dom_maxrtkey; 957 } 958 #ifdef INET 959 encap_setkeylen(); 960 #endif 961 #endif 962 if (max_keylen == 0) { 963 log(LOG_ERR, 964 "rn_init: radix functions require max_keylen be set\n"); 965 return; 966 } 967 R_Malloc(rn_zeros, char *, 3 * max_keylen); 968 if (rn_zeros == NULL) 969 panic("rn_init"); 970 Bzero(rn_zeros, 3 * max_keylen); 971 rn_ones = cp = rn_zeros + max_keylen; 972 addmask_key = cplim = rn_ones + max_keylen; 973 while (cp < cplim) 974 *cp++ = -1; 975 if (rn_inithead((void *)&mask_rnhead, 0) == 0) 976 panic("rn_init 2"); 977 }
Cache object: ac10db8a6725799294c658426ef73370
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