1 /* $NetBSD: radix.c,v 1.23 2004/04/21 21:03:43 matt 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 1.23 2004/04/21 21:03:43 matt Exp $"); 40 41 #ifndef _NET_RADIX_H_ 42 #include <sys/param.h> 43 #ifdef _KERNEL 44 #include <sys/systm.h> 45 #include <sys/malloc.h> 46 #define M_DONTWAIT M_NOWAIT 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 int max_keylen; 56 struct radix_mask *rn_mkfreelist; 57 struct radix_node_head *mask_rnhead; 58 static char *addmask_key; 59 static const char normal_chars[] = 60 {0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1}; 61 static char *rn_zeros, *rn_ones; 62 63 #define rn_masktop (mask_rnhead->rnh_treetop) 64 #undef Bcmp 65 #define Bcmp(a, b, l) (l == 0 ? 0 : bcmp((caddr_t)(a), (caddr_t)(b), (u_long)l)) 66 67 static int rn_satisfies_leaf(const char *, struct radix_node *, int); 68 static int rn_lexobetter(const void *, const void *); 69 static struct radix_mask *rn_new_radix_mask(struct radix_node *, 70 struct radix_mask *); 71 72 /* 73 * The data structure for the keys is a radix tree with one way 74 * branching removed. The index rn_b at an internal node n represents a bit 75 * position to be tested. The tree is arranged so that all descendants 76 * of a node n have keys whose bits all agree up to position rn_b - 1. 77 * (We say the index of n is rn_b.) 78 * 79 * There is at least one descendant which has a one bit at position rn_b, 80 * and at least one with a zero there. 81 * 82 * A route is determined by a pair of key and mask. We require that the 83 * bit-wise logical and of the key and mask to be the key. 84 * We define the index of a route to associated with the mask to be 85 * the first bit number in the mask where 0 occurs (with bit number 0 86 * representing the highest order bit). 87 * 88 * We say a mask is normal if every bit is 0, past the index of the mask. 89 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_b, 90 * and m is a normal mask, then the route applies to every descendant of n. 91 * If the index(m) < rn_b, this implies the trailing last few bits of k 92 * before bit b are all 0, (and hence consequently true of every descendant 93 * of n), so the route applies to all descendants of the node as well. 94 * 95 * Similar logic shows that a non-normal mask m such that 96 * index(m) <= index(n) could potentially apply to many children of n. 97 * Thus, for each non-host route, we attach its mask to a list at an internal 98 * node as high in the tree as we can go. 99 * 100 * The present version of the code makes use of normal routes in short- 101 * circuiting an explict mask and compare operation when testing whether 102 * a key satisfies a normal route, and also in remembering the unique leaf 103 * that governs a subtree. 104 */ 105 106 struct radix_node * 107 rn_search( 108 const void *v_arg, 109 struct radix_node *head) 110 { 111 const u_char * const v = v_arg; 112 struct radix_node *x; 113 114 for (x = head; x->rn_b >= 0;) { 115 if (x->rn_bmask & v[x->rn_off]) 116 x = x->rn_r; 117 else 118 x = x->rn_l; 119 } 120 return (x); 121 } 122 123 struct radix_node * 124 rn_search_m( 125 const void *v_arg, 126 struct radix_node *head, 127 const void *m_arg) 128 { 129 struct radix_node *x; 130 const u_char * const v = v_arg; 131 const u_char * const m = m_arg; 132 133 for (x = head; x->rn_b >= 0;) { 134 if ((x->rn_bmask & m[x->rn_off]) && 135 (x->rn_bmask & v[x->rn_off])) 136 x = x->rn_r; 137 else 138 x = x->rn_l; 139 } 140 return x; 141 } 142 143 int 144 rn_refines( 145 const void *m_arg, 146 const void *n_arg) 147 { 148 const char *m = m_arg; 149 const char *n = n_arg; 150 const char *lim = n + *(u_char *)n; 151 const char *lim2 = lim; 152 int longer = (*(u_char *)n++) - (int)(*(u_char *)m++); 153 int masks_are_equal = 1; 154 155 if (longer > 0) 156 lim -= longer; 157 while (n < lim) { 158 if (*n & ~(*m)) 159 return 0; 160 if (*n++ != *m++) 161 masks_are_equal = 0; 162 } 163 while (n < lim2) 164 if (*n++) 165 return 0; 166 if (masks_are_equal && (longer < 0)) 167 for (lim2 = m - longer; m < lim2; ) 168 if (*m++) 169 return 1; 170 return (!masks_are_equal); 171 } 172 173 struct radix_node * 174 rn_lookup( 175 const void *v_arg, 176 const void *m_arg, 177 struct radix_node_head *head) 178 { 179 struct radix_node *x; 180 const char *netmask = NULL; 181 182 if (m_arg) { 183 if ((x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_off)) == 0) 184 return (0); 185 netmask = x->rn_key; 186 } 187 x = rn_match(v_arg, head); 188 if (x && netmask) { 189 while (x && x->rn_mask != netmask) 190 x = x->rn_dupedkey; 191 } 192 return x; 193 } 194 195 static int 196 rn_satisfies_leaf( 197 const char *trial, 198 struct radix_node *leaf, 199 int skip) 200 { 201 const char *cp = trial; 202 const char *cp2 = leaf->rn_key; 203 const char *cp3 = leaf->rn_mask; 204 const char *cplim; 205 int length = min(*(u_char *)cp, *(u_char *)cp2); 206 207 if (cp3 == 0) 208 cp3 = rn_ones; 209 else 210 length = min(length, *(u_char *)cp3); 211 cplim = cp + length; cp3 += skip; cp2 += skip; 212 for (cp += skip; cp < cplim; cp++, cp2++, cp3++) 213 if ((*cp ^ *cp2) & *cp3) 214 return 0; 215 return 1; 216 } 217 218 struct radix_node * 219 rn_match( 220 const void *v_arg, 221 struct radix_node_head *head) 222 { 223 const char * const v = v_arg; 224 struct radix_node *t = head->rnh_treetop; 225 struct radix_node *top = t; 226 struct radix_node *x; 227 struct radix_node *saved_t; 228 const char *cp = v; 229 const char *cp2; 230 const char *cplim; 231 int off = t->rn_off; 232 int vlen = *(u_char *)cp; 233 int matched_off; 234 int test, b, rn_b; 235 236 /* 237 * Open code rn_search(v, top) to avoid overhead of extra 238 * subroutine call. 239 */ 240 for (; t->rn_b >= 0; ) { 241 if (t->rn_bmask & cp[t->rn_off]) 242 t = t->rn_r; 243 else 244 t = t->rn_l; 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 if ((t->rn_flags & RNF_ROOT) && t->rn_dupedkey) 268 t = t->rn_dupedkey; 269 return t; 270 on1: 271 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */ 272 for (b = 7; (test >>= 1) > 0;) 273 b--; 274 matched_off = cp - v; 275 b += matched_off << 3; 276 rn_b = -1 - b; 277 /* 278 * If there is a host route in a duped-key chain, it will be first. 279 */ 280 if ((saved_t = t)->rn_mask == 0) 281 t = t->rn_dupedkey; 282 for (; t; t = t->rn_dupedkey) 283 /* 284 * Even if we don't match exactly as a host, 285 * we may match if the leaf we wound up at is 286 * a route to a net. 287 */ 288 if (t->rn_flags & RNF_NORMAL) { 289 if (rn_b <= t->rn_b) 290 return t; 291 } else if (rn_satisfies_leaf(v, t, matched_off)) 292 return t; 293 t = saved_t; 294 /* start searching up the tree */ 295 do { 296 struct radix_mask *m; 297 t = t->rn_p; 298 m = t->rn_mklist; 299 if (m) { 300 /* 301 * If non-contiguous masks ever become important 302 * we can restore the masking and open coding of 303 * the search and satisfaction test and put the 304 * calculation of "off" back before the "do". 305 */ 306 do { 307 if (m->rm_flags & RNF_NORMAL) { 308 if (rn_b <= m->rm_b) 309 return (m->rm_leaf); 310 } else { 311 off = min(t->rn_off, matched_off); 312 x = rn_search_m(v, t, m->rm_mask); 313 while (x && x->rn_mask != m->rm_mask) 314 x = x->rn_dupedkey; 315 if (x && rn_satisfies_leaf(v, x, off)) 316 return x; 317 } 318 m = m->rm_mklist; 319 } while (m); 320 } 321 } while (t != top); 322 return 0; 323 } 324 325 #ifdef RN_DEBUG 326 int rn_nodenum; 327 struct radix_node *rn_clist; 328 int rn_saveinfo; 329 int rn_debug = 1; 330 #endif 331 332 struct radix_node * 333 rn_newpair( 334 const void *v, 335 int b, 336 struct radix_node nodes[2]) 337 { 338 struct radix_node *tt = nodes; 339 struct radix_node *t = tt + 1; 340 t->rn_b = b; t->rn_bmask = 0x80 >> (b & 7); 341 t->rn_l = tt; t->rn_off = b >> 3; 342 tt->rn_b = -1; tt->rn_key = v; tt->rn_p = t; 343 tt->rn_flags = t->rn_flags = RNF_ACTIVE; 344 #ifdef RN_DEBUG 345 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 346 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 347 #endif 348 return t; 349 } 350 351 struct radix_node * 352 rn_insert( 353 const void *v_arg, 354 struct radix_node_head *head, 355 int *dupentry, 356 struct radix_node nodes[2]) 357 { 358 struct radix_node *top = head->rnh_treetop; 359 struct radix_node *t = rn_search(v_arg, top); 360 struct radix_node *tt; 361 const char *v = v_arg; 362 int head_off = top->rn_off; 363 int vlen = *((u_char *)v); 364 const char *cp = v + head_off; 365 int b; 366 /* 367 * Find first bit at which v and t->rn_key differ 368 */ 369 { 370 const char *cp2 = t->rn_key + head_off; 371 const char *cplim = v + vlen; 372 int cmp_res; 373 374 while (cp < cplim) 375 if (*cp2++ != *cp++) 376 goto on1; 377 *dupentry = 1; 378 return t; 379 on1: 380 *dupentry = 0; 381 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff; 382 for (b = (cp - v) << 3; cmp_res; b--) 383 cmp_res >>= 1; 384 } 385 { 386 struct radix_node *p, *x = top; 387 cp = v; 388 do { 389 p = x; 390 if (cp[x->rn_off] & x->rn_bmask) 391 x = x->rn_r; 392 else x = x->rn_l; 393 } while (b > (unsigned) x->rn_b); /* x->rn_b < b && x->rn_b >= 0 */ 394 #ifdef RN_DEBUG 395 if (rn_debug) 396 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p); 397 #endif 398 t = rn_newpair(v_arg, b, nodes); tt = t->rn_l; 399 if ((cp[p->rn_off] & p->rn_bmask) == 0) 400 p->rn_l = t; 401 else 402 p->rn_r = t; 403 x->rn_p = t; t->rn_p = p; /* frees x, p as temp vars below */ 404 if ((cp[t->rn_off] & t->rn_bmask) == 0) { 405 t->rn_r = x; 406 } else { 407 t->rn_r = tt; t->rn_l = x; 408 } 409 #ifdef RN_DEBUG 410 if (rn_debug) 411 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p); 412 #endif 413 } 414 return (tt); 415 } 416 417 struct radix_node * 418 rn_addmask( 419 const void *n_arg, 420 int search, 421 int skip) 422 { 423 const char *netmask = n_arg; 424 const char *cp; 425 const char *cplim; 426 struct radix_node *x; 427 struct radix_node *saved_x; 428 int b = 0, mlen, j; 429 int maskduplicated, m0, isnormal; 430 static int last_zeroed = 0; 431 432 if ((mlen = *(u_char *)netmask) > max_keylen) 433 mlen = max_keylen; 434 if (skip == 0) 435 skip = 1; 436 if (mlen <= skip) 437 return (mask_rnhead->rnh_nodes); 438 if (skip > 1) 439 Bcopy(rn_ones + 1, addmask_key + 1, skip - 1); 440 if ((m0 = mlen) > skip) 441 Bcopy(netmask + skip, addmask_key + skip, mlen - skip); 442 /* 443 * Trim trailing zeroes. 444 */ 445 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;) 446 cp--; 447 mlen = cp - addmask_key; 448 if (mlen <= skip) { 449 if (m0 >= last_zeroed) 450 last_zeroed = mlen; 451 return (mask_rnhead->rnh_nodes); 452 } 453 if (m0 < last_zeroed) 454 Bzero(addmask_key + m0, last_zeroed - m0); 455 *addmask_key = last_zeroed = mlen; 456 x = rn_search(addmask_key, rn_masktop); 457 if (Bcmp(addmask_key, x->rn_key, mlen) != 0) 458 x = 0; 459 if (x || search) 460 return (x); 461 R_Malloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x)); 462 if ((saved_x = x) == 0) 463 return (0); 464 Bzero(x, max_keylen + 2 * sizeof (*x)); 465 cp = netmask = (caddr_t)(x + 2); 466 Bcopy(addmask_key, (caddr_t)(x + 2), mlen); 467 x = rn_insert(cp, mask_rnhead, &maskduplicated, x); 468 if (maskduplicated) { 469 log(LOG_ERR, "rn_addmask: mask impossibly already in tree\n"); 470 Free(saved_x); 471 return (x); 472 } 473 /* 474 * Calculate index of mask, and check for normalcy. 475 */ 476 cplim = netmask + mlen; isnormal = 1; 477 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;) 478 cp++; 479 if (cp != cplim) { 480 for (j = 0x80; (j & *cp) != 0; j >>= 1) 481 b++; 482 if (*cp != normal_chars[b] || cp != (cplim - 1)) 483 isnormal = 0; 484 } 485 b += (cp - netmask) << 3; 486 x->rn_b = -1 - b; 487 if (isnormal) 488 x->rn_flags |= RNF_NORMAL; 489 return (x); 490 } 491 492 static int /* XXX: arbitrary ordering for non-contiguous masks */ 493 rn_lexobetter( 494 const void *m_arg, 495 const void *n_arg) 496 { 497 const u_char *mp = m_arg; 498 const u_char *np = n_arg; 499 const u_char *lim; 500 501 if (*mp > *np) 502 return 1; /* not really, but need to check longer one first */ 503 if (*mp == *np) 504 for (lim = mp + *mp; mp < lim;) 505 if (*mp++ > *np++) 506 return 1; 507 return 0; 508 } 509 510 static struct radix_mask * 511 rn_new_radix_mask( 512 struct radix_node *tt, 513 struct radix_mask *next) 514 { 515 struct radix_mask *m; 516 517 MKGet(m); 518 if (m == 0) { 519 log(LOG_ERR, "Mask for route not entered\n"); 520 return (0); 521 } 522 Bzero(m, sizeof *m); 523 m->rm_b = tt->rn_b; 524 m->rm_flags = tt->rn_flags; 525 if (tt->rn_flags & RNF_NORMAL) 526 m->rm_leaf = tt; 527 else 528 m->rm_mask = tt->rn_mask; 529 m->rm_mklist = next; 530 tt->rn_mklist = m; 531 return m; 532 } 533 534 struct radix_node * 535 rn_addroute( 536 const void *v_arg, 537 const void *n_arg, 538 struct radix_node_head *head, 539 struct radix_node treenodes[2]) 540 { 541 const char *v = v_arg; 542 const char *netmask = n_arg; 543 struct radix_node *t; 544 struct radix_node *x = 0; 545 struct radix_node *tt; 546 struct radix_node *saved_tt; 547 struct radix_node *top = head->rnh_treetop; 548 short b = 0, b_leaf = 0; 549 int keyduplicated; 550 const char *mmask; 551 struct radix_mask *m, **mp; 552 553 /* 554 * In dealing with non-contiguous masks, there may be 555 * many different routes which have the same mask. 556 * We will find it useful to have a unique pointer to 557 * the mask to speed avoiding duplicate references at 558 * nodes and possibly save time in calculating indices. 559 */ 560 if (netmask) { 561 if ((x = rn_addmask(netmask, 0, top->rn_off)) == 0) 562 return (0); 563 b_leaf = x->rn_b; 564 b = -1 - x->rn_b; 565 netmask = x->rn_key; 566 } 567 /* 568 * Deal with duplicated keys: attach node to previous instance 569 */ 570 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes); 571 if (keyduplicated) { 572 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) { 573 if (tt->rn_mask == netmask) 574 return (0); 575 if (netmask == 0 || 576 (tt->rn_mask && 577 ((b_leaf < tt->rn_b) || /* index(netmask) > node */ 578 rn_refines(netmask, tt->rn_mask) || 579 rn_lexobetter(netmask, tt->rn_mask)))) 580 break; 581 } 582 /* 583 * If the mask is not duplicated, we wouldn't 584 * find it among possible duplicate key entries 585 * anyway, so the above test doesn't hurt. 586 * 587 * We sort the masks for a duplicated key the same way as 588 * in a masklist -- most specific to least specific. 589 * This may require the unfortunate nuisance of relocating 590 * the head of the list. 591 * 592 * We also reverse, or doubly link the list through the 593 * parent pointer. 594 */ 595 if (tt == saved_tt) { 596 struct radix_node *xx = x; 597 /* link in at head of list */ 598 (tt = treenodes)->rn_dupedkey = t; 599 tt->rn_flags = t->rn_flags; 600 tt->rn_p = x = t->rn_p; 601 t->rn_p = tt; 602 if (x->rn_l == t) x->rn_l = tt; else x->rn_r = tt; 603 saved_tt = tt; x = xx; 604 } else { 605 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey; 606 t->rn_dupedkey = tt; 607 tt->rn_p = t; 608 if (tt->rn_dupedkey) 609 tt->rn_dupedkey->rn_p = tt; 610 } 611 #ifdef RN_DEBUG 612 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 613 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 614 #endif 615 tt->rn_key = (caddr_t) v; 616 tt->rn_b = -1; 617 tt->rn_flags = RNF_ACTIVE; 618 } 619 /* 620 * Put mask in tree. 621 */ 622 if (netmask) { 623 tt->rn_mask = netmask; 624 tt->rn_b = x->rn_b; 625 tt->rn_flags |= x->rn_flags & RNF_NORMAL; 626 } 627 t = saved_tt->rn_p; 628 if (keyduplicated) 629 goto on2; 630 b_leaf = -1 - t->rn_b; 631 if (t->rn_r == saved_tt) x = t->rn_l; else x = t->rn_r; 632 /* Promote general routes from below */ 633 if (x->rn_b < 0) { 634 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey) 635 if (x->rn_mask && (x->rn_b >= b_leaf) && x->rn_mklist == 0) { 636 *mp = m = rn_new_radix_mask(x, 0); 637 if (m) 638 mp = &m->rm_mklist; 639 } 640 } else if (x->rn_mklist) { 641 /* 642 * Skip over masks whose index is > that of new node 643 */ 644 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 645 if (m->rm_b >= b_leaf) 646 break; 647 t->rn_mklist = m; *mp = 0; 648 } 649 on2: 650 /* Add new route to highest possible ancestor's list */ 651 if ((netmask == 0) || (b > t->rn_b )) 652 return tt; /* can't lift at all */ 653 b_leaf = tt->rn_b; 654 do { 655 x = t; 656 t = t->rn_p; 657 } while (b <= t->rn_b && x != top); 658 /* 659 * Search through routes associated with node to 660 * insert new route according to index. 661 * Need same criteria as when sorting dupedkeys to avoid 662 * double loop on deletion. 663 */ 664 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) { 665 if (m->rm_b < b_leaf) 666 continue; 667 if (m->rm_b > b_leaf) 668 break; 669 if (m->rm_flags & RNF_NORMAL) { 670 mmask = m->rm_leaf->rn_mask; 671 if (tt->rn_flags & RNF_NORMAL) { 672 log(LOG_ERR, "Non-unique normal route," 673 " mask not entered\n"); 674 return tt; 675 } 676 } else 677 mmask = m->rm_mask; 678 if (mmask == netmask) { 679 m->rm_refs++; 680 tt->rn_mklist = m; 681 return tt; 682 } 683 if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask)) 684 break; 685 } 686 *mp = rn_new_radix_mask(tt, *mp); 687 return tt; 688 } 689 690 struct radix_node * 691 rn_delete( 692 const void *v_arg, 693 const void *netmask_arg, 694 struct radix_node_head *head) 695 { 696 struct radix_node *t; 697 struct radix_node *p; 698 struct radix_node *x; 699 struct radix_node *tt; 700 struct radix_node *dupedkey; 701 struct radix_node *saved_tt; 702 struct radix_node *top; 703 struct radix_mask *m; 704 struct radix_mask *saved_m; 705 struct radix_mask **mp; 706 const char *v = v_arg; 707 const char *netmask = netmask_arg; 708 int b, head_off, vlen; 709 710 x = head->rnh_treetop; 711 tt = rn_search(v, x); 712 head_off = x->rn_off; 713 vlen = *(u_char *)v; 714 saved_tt = tt; 715 top = x; 716 if (tt == 0 || 717 Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off)) 718 return (0); 719 /* 720 * Delete our route from mask lists. 721 */ 722 if (netmask) { 723 if ((x = rn_addmask(netmask, 1, head_off)) == 0) 724 return (0); 725 netmask = x->rn_key; 726 while (tt->rn_mask != netmask) 727 if ((tt = tt->rn_dupedkey) == 0) 728 return (0); 729 } 730 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0) 731 goto on1; 732 if (tt->rn_flags & RNF_NORMAL) { 733 if (m->rm_leaf != tt || m->rm_refs > 0) { 734 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 735 return 0; /* dangling ref could cause disaster */ 736 } 737 } else { 738 if (m->rm_mask != tt->rn_mask) { 739 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 740 goto on1; 741 } 742 if (--m->rm_refs >= 0) 743 goto on1; 744 } 745 b = -1 - tt->rn_b; 746 t = saved_tt->rn_p; 747 if (b > t->rn_b) 748 goto on1; /* Wasn't lifted at all */ 749 do { 750 x = t; 751 t = t->rn_p; 752 } while (b <= t->rn_b && x != top); 753 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 754 if (m == saved_m) { 755 *mp = m->rm_mklist; 756 MKFree(m); 757 break; 758 } 759 if (m == 0) { 760 log(LOG_ERR, "rn_delete: couldn't find our annotation\n"); 761 if (tt->rn_flags & RNF_NORMAL) 762 return (0); /* Dangling ref to us */ 763 } 764 on1: 765 /* 766 * Eliminate us from tree 767 */ 768 if (tt->rn_flags & RNF_ROOT) 769 return (0); 770 #ifdef RN_DEBUG 771 /* Get us out of the creation list */ 772 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {} 773 if (t) t->rn_ybro = tt->rn_ybro; 774 #endif 775 t = tt->rn_p; 776 dupedkey = saved_tt->rn_dupedkey; 777 if (dupedkey) { 778 /* 779 * Here, tt is the deletion target, and 780 * saved_tt is the head of the dupedkey chain. 781 */ 782 if (tt == saved_tt) { 783 x = dupedkey; x->rn_p = t; 784 if (t->rn_l == tt) t->rn_l = x; else t->rn_r = x; 785 } else { 786 /* find node in front of tt on the chain */ 787 for (x = p = saved_tt; p && p->rn_dupedkey != tt;) 788 p = p->rn_dupedkey; 789 if (p) { 790 p->rn_dupedkey = tt->rn_dupedkey; 791 if (tt->rn_dupedkey) 792 tt->rn_dupedkey->rn_p = p; 793 } else log(LOG_ERR, "rn_delete: couldn't find us\n"); 794 } 795 t = tt + 1; 796 if (t->rn_flags & RNF_ACTIVE) { 797 #ifndef RN_DEBUG 798 *++x = *t; p = t->rn_p; 799 #else 800 b = t->rn_info; *++x = *t; t->rn_info = b; p = t->rn_p; 801 #endif 802 if (p->rn_l == t) p->rn_l = x; else p->rn_r = x; 803 x->rn_l->rn_p = x; x->rn_r->rn_p = x; 804 } 805 goto out; 806 } 807 if (t->rn_l == tt) x = t->rn_r; else x = t->rn_l; 808 p = t->rn_p; 809 if (p->rn_r == t) p->rn_r = x; else p->rn_l = x; 810 x->rn_p = p; 811 /* 812 * Demote routes attached to us. 813 */ 814 if (t->rn_mklist) { 815 if (x->rn_b >= 0) { 816 for (mp = &x->rn_mklist; (m = *mp);) 817 mp = &m->rm_mklist; 818 *mp = t->rn_mklist; 819 } else { 820 /* If there are any key,mask pairs in a sibling 821 duped-key chain, some subset will appear sorted 822 in the same order attached to our mklist */ 823 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey) 824 if (m == x->rn_mklist) { 825 struct radix_mask *mm = m->rm_mklist; 826 x->rn_mklist = 0; 827 if (--(m->rm_refs) < 0) 828 MKFree(m); 829 m = mm; 830 } 831 if (m) 832 log(LOG_ERR, "%s %p at %p\n", 833 "rn_delete: Orphaned Mask", m, x); 834 } 835 } 836 /* 837 * We may be holding an active internal node in the tree. 838 */ 839 x = tt + 1; 840 if (t != x) { 841 #ifndef RN_DEBUG 842 *t = *x; 843 #else 844 b = t->rn_info; *t = *x; t->rn_info = b; 845 #endif 846 t->rn_l->rn_p = t; t->rn_r->rn_p = t; 847 p = x->rn_p; 848 if (p->rn_l == x) p->rn_l = t; else p->rn_r = t; 849 } 850 out: 851 tt->rn_flags &= ~RNF_ACTIVE; 852 tt[1].rn_flags &= ~RNF_ACTIVE; 853 return (tt); 854 } 855 856 int 857 rn_walktree( 858 struct radix_node_head *h, 859 int (*f)(struct radix_node *, void *), 860 void *w) 861 { 862 int error; 863 struct radix_node *base; 864 struct radix_node *next; 865 struct radix_node *rn = h->rnh_treetop; 866 /* 867 * This gets complicated because we may delete the node 868 * while applying the function f to it, so we need to calculate 869 * the successor node in advance. 870 */ 871 /* First time through node, go left */ 872 while (rn->rn_b >= 0) 873 rn = rn->rn_l; 874 for (;;) { 875 base = rn; 876 /* If at right child go back up, otherwise, go right */ 877 while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0) 878 rn = rn->rn_p; 879 /* Find the next *leaf* since next node might vanish, too */ 880 for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;) 881 rn = rn->rn_l; 882 next = rn; 883 /* Process leaves */ 884 while ((rn = base) != NULL) { 885 base = rn->rn_dupedkey; 886 if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w))) 887 return (error); 888 } 889 rn = next; 890 if (rn->rn_flags & RNF_ROOT) 891 return (0); 892 } 893 /* NOTREACHED */ 894 } 895 896 int 897 rn_inithead(head, off) 898 void **head; 899 int off; 900 { 901 struct radix_node_head *rnh; 902 903 if (*head) 904 return (1); 905 R_Malloc(rnh, struct radix_node_head *, sizeof (*rnh)); 906 if (rnh == 0) 907 return (0); 908 *head = rnh; 909 return rn_inithead0(rnh, off); 910 } 911 912 int 913 rn_inithead0(rnh, off) 914 struct radix_node_head *rnh; 915 int off; 916 { 917 struct radix_node *t; 918 struct radix_node *tt; 919 struct radix_node *ttt; 920 921 Bzero(rnh, sizeof (*rnh)); 922 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes); 923 ttt = rnh->rnh_nodes + 2; 924 t->rn_r = ttt; 925 t->rn_p = t; 926 tt = t->rn_l; 927 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE; 928 tt->rn_b = -1 - off; 929 *ttt = *tt; 930 ttt->rn_key = rn_ones; 931 rnh->rnh_addaddr = rn_addroute; 932 rnh->rnh_deladdr = rn_delete; 933 rnh->rnh_matchaddr = rn_match; 934 rnh->rnh_lookup = rn_lookup; 935 rnh->rnh_walktree = rn_walktree; 936 rnh->rnh_treetop = t; 937 return (1); 938 } 939 940 void 941 rn_init() 942 { 943 char *cp, *cplim; 944 #ifdef _KERNEL 945 struct domain *dom; 946 947 for (dom = domains; dom; dom = dom->dom_next) 948 if (dom->dom_maxrtkey > max_keylen) 949 max_keylen = dom->dom_maxrtkey; 950 #endif 951 if (max_keylen == 0) { 952 log(LOG_ERR, 953 "rn_init: radix functions require max_keylen be set\n"); 954 return; 955 } 956 R_Malloc(rn_zeros, char *, 3 * max_keylen); 957 if (rn_zeros == NULL) 958 panic("rn_init"); 959 Bzero(rn_zeros, 3 * max_keylen); 960 rn_ones = cp = rn_zeros + max_keylen; 961 addmask_key = cplim = rn_ones + max_keylen; 962 while (cp < cplim) 963 *cp++ = -1; 964 if (rn_inithead((void *)&mask_rnhead, 0) == 0) 965 panic("rn_init 2"); 966 } 967