1 /* $NetBSD: radix.c,v 1.27 2005/01/24 04:46:49 enami 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 1.27 2005/01/24 04:46:49 enami 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 #undef Bcmp 68 #define Bcmp(a, b, l) (l == 0 ? 0 : bcmp((caddr_t)(a), (caddr_t)(b), (u_long)l)) 69 70 static int rn_satisfies_leaf(const char *, struct radix_node *, int); 71 static int rn_lexobetter(const void *, const void *); 72 static struct radix_mask *rn_new_radix_mask(struct radix_node *, 73 struct radix_mask *); 74 75 /* 76 * The data structure for the keys is a radix tree with one way 77 * branching removed. The index rn_b at an internal node n represents a bit 78 * position to be tested. The tree is arranged so that all descendants 79 * of a node n have keys whose bits all agree up to position rn_b - 1. 80 * (We say the index of n is rn_b.) 81 * 82 * There is at least one descendant which has a one bit at position rn_b, 83 * and at least one with a zero there. 84 * 85 * A route is determined by a pair of key and mask. We require that the 86 * bit-wise logical and of the key and mask to be the key. 87 * We define the index of a route to associated with the mask to be 88 * the first bit number in the mask where 0 occurs (with bit number 0 89 * representing the highest order bit). 90 * 91 * We say a mask is normal if every bit is 0, past the index of the mask. 92 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_b, 93 * and m is a normal mask, then the route applies to every descendant of n. 94 * If the index(m) < rn_b, this implies the trailing last few bits of k 95 * before bit b are all 0, (and hence consequently true of every descendant 96 * of n), so the route applies to all descendants of the node as well. 97 * 98 * Similar logic shows that a non-normal mask m such that 99 * index(m) <= index(n) could potentially apply to many children of n. 100 * Thus, for each non-host route, we attach its mask to a list at an internal 101 * node as high in the tree as we can go. 102 * 103 * The present version of the code makes use of normal routes in short- 104 * circuiting an explict mask and compare operation when testing whether 105 * a key satisfies a normal route, and also in remembering the unique leaf 106 * that governs a subtree. 107 */ 108 109 struct radix_node * 110 rn_search( 111 const void *v_arg, 112 struct radix_node *head) 113 { 114 const u_char * const v = v_arg; 115 struct radix_node *x; 116 117 for (x = head; x->rn_b >= 0;) { 118 if (x->rn_bmask & v[x->rn_off]) 119 x = x->rn_r; 120 else 121 x = x->rn_l; 122 } 123 return (x); 124 } 125 126 struct radix_node * 127 rn_search_m( 128 const void *v_arg, 129 struct radix_node *head, 130 const void *m_arg) 131 { 132 struct radix_node *x; 133 const u_char * const v = v_arg; 134 const u_char * const m = m_arg; 135 136 for (x = head; x->rn_b >= 0;) { 137 if ((x->rn_bmask & m[x->rn_off]) && 138 (x->rn_bmask & v[x->rn_off])) 139 x = x->rn_r; 140 else 141 x = x->rn_l; 142 } 143 return x; 144 } 145 146 int 147 rn_refines( 148 const void *m_arg, 149 const void *n_arg) 150 { 151 const char *m = m_arg; 152 const char *n = n_arg; 153 const char *lim = n + *(u_char *)n; 154 const char *lim2 = lim; 155 int longer = (*(u_char *)n++) - (int)(*(u_char *)m++); 156 int masks_are_equal = 1; 157 158 if (longer > 0) 159 lim -= longer; 160 while (n < lim) { 161 if (*n & ~(*m)) 162 return 0; 163 if (*n++ != *m++) 164 masks_are_equal = 0; 165 } 166 while (n < lim2) 167 if (*n++) 168 return 0; 169 if (masks_are_equal && (longer < 0)) 170 for (lim2 = m - longer; m < lim2; ) 171 if (*m++) 172 return 1; 173 return (!masks_are_equal); 174 } 175 176 struct radix_node * 177 rn_lookup( 178 const void *v_arg, 179 const void *m_arg, 180 struct radix_node_head *head) 181 { 182 struct radix_node *x; 183 const char *netmask = NULL; 184 185 if (m_arg) { 186 if ((x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_off)) == 0) 187 return (0); 188 netmask = x->rn_key; 189 } 190 x = rn_match(v_arg, head); 191 if (x && netmask) { 192 while (x && x->rn_mask != netmask) 193 x = x->rn_dupedkey; 194 } 195 return x; 196 } 197 198 static int 199 rn_satisfies_leaf( 200 const char *trial, 201 struct radix_node *leaf, 202 int skip) 203 { 204 const char *cp = trial; 205 const char *cp2 = leaf->rn_key; 206 const char *cp3 = leaf->rn_mask; 207 const char *cplim; 208 int length = min(*(u_char *)cp, *(u_char *)cp2); 209 210 if (cp3 == 0) 211 cp3 = rn_ones; 212 else 213 length = min(length, *(u_char *)cp3); 214 cplim = cp + length; cp3 += skip; cp2 += skip; 215 for (cp += skip; cp < cplim; cp++, cp2++, cp3++) 216 if ((*cp ^ *cp2) & *cp3) 217 return 0; 218 return 1; 219 } 220 221 struct radix_node * 222 rn_match( 223 const void *v_arg, 224 struct radix_node_head *head) 225 { 226 const char * const v = v_arg; 227 struct radix_node *t = head->rnh_treetop; 228 struct radix_node *top = t; 229 struct radix_node *x; 230 struct radix_node *saved_t; 231 const char *cp = v; 232 const char *cp2; 233 const char *cplim; 234 int off = t->rn_off; 235 int vlen = *(u_char *)cp; 236 int matched_off; 237 int test, b, rn_b; 238 239 /* 240 * Open code rn_search(v, top) to avoid overhead of extra 241 * subroutine call. 242 */ 243 for (; t->rn_b >= 0; ) { 244 if (t->rn_bmask & cp[t->rn_off]) 245 t = t->rn_r; 246 else 247 t = t->rn_l; 248 } 249 /* 250 * See if we match exactly as a host destination 251 * or at least learn how many bits match, for normal mask finesse. 252 * 253 * It doesn't hurt us to limit how many bytes to check 254 * to the length of the mask, since if it matches we had a genuine 255 * match and the leaf we have is the most specific one anyway; 256 * if it didn't match with a shorter length it would fail 257 * with a long one. This wins big for class B&C netmasks which 258 * are probably the most common case... 259 */ 260 if (t->rn_mask) 261 vlen = *(u_char *)t->rn_mask; 262 cp += off; cp2 = t->rn_key + off; cplim = v + vlen; 263 for (; cp < cplim; cp++, cp2++) 264 if (*cp != *cp2) 265 goto on1; 266 /* 267 * This extra grot is in case we are explicitly asked 268 * to look up the default. Ugh! 269 */ 270 if ((t->rn_flags & RNF_ROOT) && t->rn_dupedkey) 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_b = -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_b <= t->rn_b) 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 struct radix_mask *m; 300 t = t->rn_p; 301 m = t->rn_mklist; 302 if (m) { 303 /* 304 * If non-contiguous masks ever become important 305 * we can restore the masking and open coding of 306 * the search and satisfaction test and put the 307 * calculation of "off" back before the "do". 308 */ 309 do { 310 if (m->rm_flags & RNF_NORMAL) { 311 if (rn_b <= m->rm_b) 312 return (m->rm_leaf); 313 } else { 314 off = min(t->rn_off, matched_off); 315 x = rn_search_m(v, t, m->rm_mask); 316 while (x && x->rn_mask != m->rm_mask) 317 x = x->rn_dupedkey; 318 if (x && rn_satisfies_leaf(v, x, off)) 319 return x; 320 } 321 m = m->rm_mklist; 322 } while (m); 323 } 324 } while (t != top); 325 return 0; 326 } 327 328 #ifdef RN_DEBUG 329 int rn_nodenum; 330 struct radix_node *rn_clist; 331 int rn_saveinfo; 332 int rn_debug = 1; 333 #endif 334 335 struct radix_node * 336 rn_newpair( 337 const void *v, 338 int b, 339 struct radix_node nodes[2]) 340 { 341 struct radix_node *tt = nodes; 342 struct radix_node *t = tt + 1; 343 t->rn_b = b; t->rn_bmask = 0x80 >> (b & 7); 344 t->rn_l = tt; t->rn_off = b >> 3; 345 tt->rn_b = -1; tt->rn_key = v; tt->rn_p = t; 346 tt->rn_flags = t->rn_flags = RNF_ACTIVE; 347 #ifdef RN_DEBUG 348 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 349 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 350 #endif 351 return t; 352 } 353 354 struct radix_node * 355 rn_insert( 356 const void *v_arg, 357 struct radix_node_head *head, 358 int *dupentry, 359 struct radix_node nodes[2]) 360 { 361 struct radix_node *top = head->rnh_treetop; 362 struct radix_node *t = rn_search(v_arg, top); 363 struct radix_node *tt; 364 const char *v = v_arg; 365 int head_off = top->rn_off; 366 int vlen = *((u_char *)v); 367 const char *cp = v + head_off; 368 int b; 369 /* 370 * Find first bit at which v and t->rn_key differ 371 */ 372 { 373 const char *cp2 = t->rn_key + head_off; 374 const char *cplim = v + vlen; 375 int cmp_res; 376 377 while (cp < cplim) 378 if (*cp2++ != *cp++) 379 goto on1; 380 *dupentry = 1; 381 return t; 382 on1: 383 *dupentry = 0; 384 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff; 385 for (b = (cp - v) << 3; cmp_res; b--) 386 cmp_res >>= 1; 387 } 388 { 389 struct radix_node *p, *x = top; 390 cp = v; 391 do { 392 p = x; 393 if (cp[x->rn_off] & x->rn_bmask) 394 x = x->rn_r; 395 else x = x->rn_l; 396 } while (b > (unsigned) x->rn_b); /* x->rn_b < b && x->rn_b >= 0 */ 397 #ifdef RN_DEBUG 398 if (rn_debug) 399 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p); 400 #endif 401 t = rn_newpair(v_arg, b, nodes); tt = t->rn_l; 402 if ((cp[p->rn_off] & p->rn_bmask) == 0) 403 p->rn_l = t; 404 else 405 p->rn_r = t; 406 x->rn_p = t; t->rn_p = p; /* frees x, p as temp vars below */ 407 if ((cp[t->rn_off] & t->rn_bmask) == 0) { 408 t->rn_r = x; 409 } else { 410 t->rn_r = tt; t->rn_l = x; 411 } 412 #ifdef RN_DEBUG 413 if (rn_debug) 414 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p); 415 #endif 416 } 417 return (tt); 418 } 419 420 struct radix_node * 421 rn_addmask( 422 const void *n_arg, 423 int search, 424 int skip) 425 { 426 const char *netmask = n_arg; 427 const char *cp; 428 const char *cplim; 429 struct radix_node *x; 430 struct radix_node *saved_x; 431 int b = 0, mlen, j; 432 int maskduplicated, m0, isnormal; 433 static int last_zeroed = 0; 434 435 if ((mlen = *(u_char *)netmask) > max_keylen) 436 mlen = max_keylen; 437 if (skip == 0) 438 skip = 1; 439 if (mlen <= skip) 440 return (mask_rnhead->rnh_nodes); 441 if (skip > 1) 442 Bcopy(rn_ones + 1, addmask_key + 1, skip - 1); 443 if ((m0 = mlen) > skip) 444 Bcopy(netmask + skip, addmask_key + skip, mlen - skip); 445 /* 446 * Trim trailing zeroes. 447 */ 448 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;) 449 cp--; 450 mlen = cp - addmask_key; 451 if (mlen <= skip) { 452 if (m0 >= last_zeroed) 453 last_zeroed = mlen; 454 return (mask_rnhead->rnh_nodes); 455 } 456 if (m0 < last_zeroed) 457 Bzero(addmask_key + m0, last_zeroed - m0); 458 *addmask_key = last_zeroed = mlen; 459 x = rn_search(addmask_key, rn_masktop); 460 if (Bcmp(addmask_key, x->rn_key, mlen) != 0) 461 x = 0; 462 if (x || search) 463 return (x); 464 R_Malloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x)); 465 if ((saved_x = x) == 0) 466 return (0); 467 Bzero(x, max_keylen + 2 * sizeof (*x)); 468 cp = netmask = (caddr_t)(x + 2); 469 Bcopy(addmask_key, (caddr_t)(x + 2), mlen); 470 x = rn_insert(cp, mask_rnhead, &maskduplicated, x); 471 if (maskduplicated) { 472 log(LOG_ERR, "rn_addmask: mask impossibly already in tree\n"); 473 Free(saved_x); 474 return (x); 475 } 476 /* 477 * Calculate index of mask, and check for normalcy. 478 */ 479 cplim = netmask + mlen; isnormal = 1; 480 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;) 481 cp++; 482 if (cp != cplim) { 483 for (j = 0x80; (j & *cp) != 0; j >>= 1) 484 b++; 485 if (*cp != normal_chars[b] || cp != (cplim - 1)) 486 isnormal = 0; 487 } 488 b += (cp - netmask) << 3; 489 x->rn_b = -1 - b; 490 if (isnormal) 491 x->rn_flags |= RNF_NORMAL; 492 return (x); 493 } 494 495 static int /* XXX: arbitrary ordering for non-contiguous masks */ 496 rn_lexobetter( 497 const void *m_arg, 498 const void *n_arg) 499 { 500 const u_char *mp = m_arg; 501 const u_char *np = n_arg; 502 const u_char *lim; 503 504 if (*mp > *np) 505 return 1; /* not really, but need to check longer one first */ 506 if (*mp == *np) 507 for (lim = mp + *mp; mp < lim;) 508 if (*mp++ > *np++) 509 return 1; 510 return 0; 511 } 512 513 static struct radix_mask * 514 rn_new_radix_mask( 515 struct radix_node *tt, 516 struct radix_mask *next) 517 { 518 struct radix_mask *m; 519 520 MKGet(m); 521 if (m == 0) { 522 log(LOG_ERR, "Mask for route not entered\n"); 523 return (0); 524 } 525 Bzero(m, sizeof *m); 526 m->rm_b = tt->rn_b; 527 m->rm_flags = tt->rn_flags; 528 if (tt->rn_flags & RNF_NORMAL) 529 m->rm_leaf = tt; 530 else 531 m->rm_mask = tt->rn_mask; 532 m->rm_mklist = next; 533 tt->rn_mklist = m; 534 return m; 535 } 536 537 struct radix_node * 538 rn_addroute( 539 const void *v_arg, 540 const void *n_arg, 541 struct radix_node_head *head, 542 struct radix_node treenodes[2]) 543 { 544 const char *v = v_arg; 545 const char *netmask = n_arg; 546 struct radix_node *t; 547 struct radix_node *x = 0; 548 struct radix_node *tt; 549 struct radix_node *saved_tt; 550 struct radix_node *top = head->rnh_treetop; 551 short b = 0, b_leaf = 0; 552 int keyduplicated; 553 const char *mmask; 554 struct radix_mask *m, **mp; 555 556 /* 557 * In dealing with non-contiguous masks, there may be 558 * many different routes which have the same mask. 559 * We will find it useful to have a unique pointer to 560 * the mask to speed avoiding duplicate references at 561 * nodes and possibly save time in calculating indices. 562 */ 563 if (netmask) { 564 if ((x = rn_addmask(netmask, 0, top->rn_off)) == 0) 565 return (0); 566 b_leaf = x->rn_b; 567 b = -1 - x->rn_b; 568 netmask = x->rn_key; 569 } 570 /* 571 * Deal with duplicated keys: attach node to previous instance 572 */ 573 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes); 574 if (keyduplicated) { 575 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) { 576 if (tt->rn_mask == netmask) 577 return (0); 578 if (netmask == 0 || 579 (tt->rn_mask && 580 ((b_leaf < tt->rn_b) || /* index(netmask) > node */ 581 rn_refines(netmask, tt->rn_mask) || 582 rn_lexobetter(netmask, tt->rn_mask)))) 583 break; 584 } 585 /* 586 * If the mask is not duplicated, we wouldn't 587 * find it among possible duplicate key entries 588 * anyway, so the above test doesn't hurt. 589 * 590 * We sort the masks for a duplicated key the same way as 591 * in a masklist -- most specific to least specific. 592 * This may require the unfortunate nuisance of relocating 593 * the head of the list. 594 * 595 * We also reverse, or doubly link the list through the 596 * parent pointer. 597 */ 598 if (tt == saved_tt) { 599 struct radix_node *xx = x; 600 /* link in at head of list */ 601 (tt = treenodes)->rn_dupedkey = t; 602 tt->rn_flags = t->rn_flags; 603 tt->rn_p = x = t->rn_p; 604 t->rn_p = tt; 605 if (x->rn_l == t) x->rn_l = tt; else x->rn_r = tt; 606 saved_tt = tt; x = xx; 607 } else { 608 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey; 609 t->rn_dupedkey = tt; 610 tt->rn_p = t; 611 if (tt->rn_dupedkey) 612 tt->rn_dupedkey->rn_p = tt; 613 } 614 #ifdef RN_DEBUG 615 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 616 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 617 #endif 618 tt->rn_key = (caddr_t) v; 619 tt->rn_b = -1; 620 tt->rn_flags = RNF_ACTIVE; 621 } 622 /* 623 * Put mask in tree. 624 */ 625 if (netmask) { 626 tt->rn_mask = netmask; 627 tt->rn_b = x->rn_b; 628 tt->rn_flags |= x->rn_flags & RNF_NORMAL; 629 } 630 t = saved_tt->rn_p; 631 if (keyduplicated) 632 goto on2; 633 b_leaf = -1 - t->rn_b; 634 if (t->rn_r == saved_tt) x = t->rn_l; else x = t->rn_r; 635 /* Promote general routes from below */ 636 if (x->rn_b < 0) { 637 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey) 638 if (x->rn_mask && (x->rn_b >= b_leaf) && x->rn_mklist == 0) { 639 *mp = m = rn_new_radix_mask(x, 0); 640 if (m) 641 mp = &m->rm_mklist; 642 } 643 } else if (x->rn_mklist) { 644 /* 645 * Skip over masks whose index is > that of new node 646 */ 647 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 648 if (m->rm_b >= b_leaf) 649 break; 650 t->rn_mklist = m; *mp = 0; 651 } 652 on2: 653 /* Add new route to highest possible ancestor's list */ 654 if ((netmask == 0) || (b > t->rn_b )) 655 return tt; /* can't lift at all */ 656 b_leaf = tt->rn_b; 657 do { 658 x = t; 659 t = t->rn_p; 660 } while (b <= t->rn_b && x != top); 661 /* 662 * Search through routes associated with node to 663 * insert new route according to index. 664 * Need same criteria as when sorting dupedkeys to avoid 665 * double loop on deletion. 666 */ 667 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) { 668 if (m->rm_b < b_leaf) 669 continue; 670 if (m->rm_b > b_leaf) 671 break; 672 if (m->rm_flags & RNF_NORMAL) { 673 mmask = m->rm_leaf->rn_mask; 674 if (tt->rn_flags & RNF_NORMAL) { 675 log(LOG_ERR, "Non-unique normal route," 676 " mask not entered\n"); 677 return tt; 678 } 679 } else 680 mmask = m->rm_mask; 681 if (mmask == netmask) { 682 m->rm_refs++; 683 tt->rn_mklist = m; 684 return tt; 685 } 686 if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask)) 687 break; 688 } 689 *mp = rn_new_radix_mask(tt, *mp); 690 return tt; 691 } 692 693 struct radix_node * 694 rn_delete( 695 const void *v_arg, 696 const void *netmask_arg, 697 struct radix_node_head *head) 698 { 699 struct radix_node *t; 700 struct radix_node *p; 701 struct radix_node *x; 702 struct radix_node *tt; 703 struct radix_node *dupedkey; 704 struct radix_node *saved_tt; 705 struct radix_node *top; 706 struct radix_mask *m; 707 struct radix_mask *saved_m; 708 struct radix_mask **mp; 709 const char *v = v_arg; 710 const char *netmask = netmask_arg; 711 int b, head_off, vlen; 712 713 x = head->rnh_treetop; 714 tt = rn_search(v, x); 715 head_off = x->rn_off; 716 vlen = *(u_char *)v; 717 saved_tt = tt; 718 top = x; 719 if (tt == 0 || 720 Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off)) 721 return (0); 722 /* 723 * Delete our route from mask lists. 724 */ 725 if (netmask) { 726 if ((x = rn_addmask(netmask, 1, head_off)) == 0) 727 return (0); 728 netmask = x->rn_key; 729 while (tt->rn_mask != netmask) 730 if ((tt = tt->rn_dupedkey) == 0) 731 return (0); 732 } 733 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0) 734 goto on1; 735 if (tt->rn_flags & RNF_NORMAL) { 736 if (m->rm_leaf != tt || m->rm_refs > 0) { 737 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 738 return 0; /* dangling ref could cause disaster */ 739 } 740 } else { 741 if (m->rm_mask != tt->rn_mask) { 742 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 743 goto on1; 744 } 745 if (--m->rm_refs >= 0) 746 goto on1; 747 } 748 b = -1 - tt->rn_b; 749 t = saved_tt->rn_p; 750 if (b > t->rn_b) 751 goto on1; /* Wasn't lifted at all */ 752 do { 753 x = t; 754 t = t->rn_p; 755 } while (b <= t->rn_b && x != top); 756 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 757 if (m == saved_m) { 758 *mp = m->rm_mklist; 759 MKFree(m); 760 break; 761 } 762 if (m == 0) { 763 log(LOG_ERR, "rn_delete: couldn't find our annotation\n"); 764 if (tt->rn_flags & RNF_NORMAL) 765 return (0); /* Dangling ref to us */ 766 } 767 on1: 768 /* 769 * Eliminate us from tree 770 */ 771 if (tt->rn_flags & RNF_ROOT) 772 return (0); 773 #ifdef RN_DEBUG 774 /* Get us out of the creation list */ 775 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {} 776 if (t) t->rn_ybro = tt->rn_ybro; 777 #endif 778 t = tt->rn_p; 779 dupedkey = saved_tt->rn_dupedkey; 780 if (dupedkey) { 781 /* 782 * Here, tt is the deletion target, and 783 * saved_tt is the head of the dupedkey chain. 784 */ 785 if (tt == saved_tt) { 786 x = dupedkey; x->rn_p = t; 787 if (t->rn_l == tt) t->rn_l = x; else t->rn_r = x; 788 } else { 789 /* find node in front of tt on the chain */ 790 for (x = p = saved_tt; p && p->rn_dupedkey != tt;) 791 p = p->rn_dupedkey; 792 if (p) { 793 p->rn_dupedkey = tt->rn_dupedkey; 794 if (tt->rn_dupedkey) 795 tt->rn_dupedkey->rn_p = p; 796 } else log(LOG_ERR, "rn_delete: couldn't find us\n"); 797 } 798 t = tt + 1; 799 if (t->rn_flags & RNF_ACTIVE) { 800 #ifndef RN_DEBUG 801 *++x = *t; p = t->rn_p; 802 #else 803 b = t->rn_info; *++x = *t; t->rn_info = b; p = t->rn_p; 804 #endif 805 if (p->rn_l == t) p->rn_l = x; else p->rn_r = x; 806 x->rn_l->rn_p = x; x->rn_r->rn_p = x; 807 } 808 goto out; 809 } 810 if (t->rn_l == tt) x = t->rn_r; else x = t->rn_l; 811 p = t->rn_p; 812 if (p->rn_r == t) p->rn_r = x; else p->rn_l = x; 813 x->rn_p = p; 814 /* 815 * Demote routes attached to us. 816 */ 817 if (t->rn_mklist) { 818 if (x->rn_b >= 0) { 819 for (mp = &x->rn_mklist; (m = *mp);) 820 mp = &m->rm_mklist; 821 *mp = t->rn_mklist; 822 } else { 823 /* If there are any key,mask pairs in a sibling 824 duped-key chain, some subset will appear sorted 825 in the same order attached to our mklist */ 826 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey) 827 if (m == x->rn_mklist) { 828 struct radix_mask *mm = m->rm_mklist; 829 x->rn_mklist = 0; 830 if (--(m->rm_refs) < 0) 831 MKFree(m); 832 m = mm; 833 } 834 if (m) 835 log(LOG_ERR, "%s %p at %p\n", 836 "rn_delete: Orphaned Mask", m, x); 837 } 838 } 839 /* 840 * We may be holding an active internal node in the tree. 841 */ 842 x = tt + 1; 843 if (t != x) { 844 #ifndef RN_DEBUG 845 *t = *x; 846 #else 847 b = t->rn_info; *t = *x; t->rn_info = b; 848 #endif 849 t->rn_l->rn_p = t; t->rn_r->rn_p = t; 850 p = x->rn_p; 851 if (p->rn_l == x) p->rn_l = t; else p->rn_r = t; 852 } 853 out: 854 tt->rn_flags &= ~RNF_ACTIVE; 855 tt[1].rn_flags &= ~RNF_ACTIVE; 856 return (tt); 857 } 858 859 int 860 rn_walktree( 861 struct radix_node_head *h, 862 int (*f)(struct radix_node *, void *), 863 void *w) 864 { 865 int error; 866 struct radix_node *base; 867 struct radix_node *next; 868 struct radix_node *rn = h->rnh_treetop; 869 /* 870 * This gets complicated because we may delete the node 871 * while applying the function f to it, so we need to calculate 872 * the successor node in advance. 873 */ 874 /* First time through node, go left */ 875 while (rn->rn_b >= 0) 876 rn = rn->rn_l; 877 for (;;) { 878 base = rn; 879 /* If at right child go back up, otherwise, go right */ 880 while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0) 881 rn = rn->rn_p; 882 /* Find the next *leaf* since next node might vanish, too */ 883 for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;) 884 rn = rn->rn_l; 885 next = rn; 886 /* Process leaves */ 887 while ((rn = base) != NULL) { 888 base = rn->rn_dupedkey; 889 if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w))) 890 return (error); 891 } 892 rn = next; 893 if (rn->rn_flags & RNF_ROOT) 894 return (0); 895 } 896 /* NOTREACHED */ 897 } 898 899 int 900 rn_inithead(head, off) 901 void **head; 902 int off; 903 { 904 struct radix_node_head *rnh; 905 906 if (*head) 907 return (1); 908 R_Malloc(rnh, struct radix_node_head *, sizeof (*rnh)); 909 if (rnh == 0) 910 return (0); 911 *head = rnh; 912 return rn_inithead0(rnh, off); 913 } 914 915 int 916 rn_inithead0(rnh, off) 917 struct radix_node_head *rnh; 918 int off; 919 { 920 struct radix_node *t; 921 struct radix_node *tt; 922 struct radix_node *ttt; 923 924 Bzero(rnh, sizeof (*rnh)); 925 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes); 926 ttt = rnh->rnh_nodes + 2; 927 t->rn_r = ttt; 928 t->rn_p = t; 929 tt = t->rn_l; 930 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE; 931 tt->rn_b = -1 - off; 932 *ttt = *tt; 933 ttt->rn_key = rn_ones; 934 rnh->rnh_addaddr = rn_addroute; 935 rnh->rnh_deladdr = rn_delete; 936 rnh->rnh_matchaddr = rn_match; 937 rnh->rnh_lookup = rn_lookup; 938 rnh->rnh_walktree = rn_walktree; 939 rnh->rnh_treetop = t; 940 return (1); 941 } 942 943 void 944 rn_init() 945 { 946 char *cp, *cplim; 947 #ifdef _KERNEL 948 static int initialized; 949 __link_set_decl(domains, struct domain); 950 struct domain *const *dpp; 951 952 if (initialized) 953 return; 954 initialized = 1; 955 956 __link_set_foreach(dpp, domains) { 957 if ((*dpp)->dom_maxrtkey > max_keylen) 958 max_keylen = (*dpp)->dom_maxrtkey; 959 } 960 #ifdef INET 961 encap_setkeylen(); 962 #endif 963 #endif 964 if (max_keylen == 0) { 965 log(LOG_ERR, 966 "rn_init: radix functions require max_keylen be set\n"); 967 return; 968 } 969 R_Malloc(rn_zeros, char *, 3 * max_keylen); 970 if (rn_zeros == NULL) 971 panic("rn_init"); 972 Bzero(rn_zeros, 3 * max_keylen); 973 rn_ones = cp = rn_zeros + max_keylen; 974 addmask_key = cplim = rn_ones + max_keylen; 975 while (cp < cplim) 976 *cp++ = -1; 977 if (rn_inithead((void *)&mask_rnhead, 0) == 0) 978 panic("rn_init 2"); 979 } 980