1 /* 2 * Copyright (c) 1988, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)radix.c 8.4 (Berkeley) 11/2/94 30 * 31 * $FreeBSD$ 32 */ 33 34 /* 35 * Routines to build and maintain radix trees for routing lookups. 36 */ 37 38 #include "defs.h" 39 40 #ifdef __NetBSD__ 41 __RCSID("$NetBSD$"); 42 #elif defined(__FreeBSD__) 43 __RCSID("$FreeBSD$"); 44 #else 45 __RCSID("$Revision: 2.23 $"); 46 #ident "$Revision: 2.23 $" 47 #endif 48 #ident "$FreeBSD$" 49 50 #define log(x, msg) syslog(x, msg) 51 #define panic(s) {log(LOG_ERR,s); exit(1);} 52 #define min(a,b) (((a)<(b))?(a):(b)) 53 54 int max_keylen; 55 struct radix_mask *rn_mkfreelist; 56 struct radix_node_head *mask_rnhead; 57 static char *addmask_key; 58 static char normal_chars[] = {0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1}; 59 static char *rn_zeros, *rn_ones; 60 61 #define rn_masktop (mask_rnhead->rnh_treetop) 62 #undef Bcmp 63 #define Bcmp(a, b, l) (l == 0 ? 0 \ 64 : memcmp((caddr_t)(a), (caddr_t)(b), (size_t)l)) 65 66 static int rn_satisfies_leaf(char *, struct radix_node *, int); 67 68 /* 69 * The data structure for the keys is a radix tree with one way 70 * branching removed. The index rn_b at an internal node n represents a bit 71 * position to be tested. The tree is arranged so that all descendants 72 * of a node n have keys whose bits all agree up to position rn_b - 1. 73 * (We say the index of n is rn_b.) 74 * 75 * There is at least one descendant which has a one bit at position rn_b, 76 * and at least one with a zero there. 77 * 78 * A route is determined by a pair of key and mask. We require that the 79 * bit-wise logical and of the key and mask to be the key. 80 * We define the index of a route to associated with the mask to be 81 * the first bit number in the mask where 0 occurs (with bit number 0 82 * representing the highest order bit). 83 * 84 * We say a mask is normal if every bit is 0, past the index of the mask. 85 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_b, 86 * and m is a normal mask, then the route applies to every descendant of n. 87 * If the index(m) < rn_b, this implies the trailing last few bits of k 88 * before bit b are all 0, (and hence consequently true of every descendant 89 * of n), so the route applies to all descendants of the node as well. 90 * 91 * Similar logic shows that a non-normal mask m such that 92 * index(m) <= index(n) could potentially apply to many children of n. 93 * Thus, for each non-host route, we attach its mask to a list at an internal 94 * node as high in the tree as we can go. 95 * 96 * The present version of the code makes use of normal routes in short- 97 * circuiting an explict mask and compare operation when testing whether 98 * a key satisfies a normal route, and also in remembering the unique leaf 99 * that governs a subtree. 100 */ 101 102 struct radix_node * 103 rn_search(void *v_arg, 104 struct radix_node *head) 105 { 106 struct radix_node *x; 107 caddr_t v; 108 109 for (x = head, v = v_arg; x->rn_b >= 0;) { 110 if (x->rn_bmask & v[x->rn_off]) 111 x = x->rn_r; 112 else 113 x = x->rn_l; 114 } 115 return (x); 116 } 117 118 struct radix_node * 119 rn_search_m(void *v_arg, 120 struct radix_node *head, 121 void *m_arg) 122 { 123 struct radix_node *x; 124 caddr_t v = v_arg, m = m_arg; 125 126 for (x = head; x->rn_b >= 0;) { 127 if ((x->rn_bmask & m[x->rn_off]) && 128 (x->rn_bmask & v[x->rn_off])) 129 x = x->rn_r; 130 else 131 x = x->rn_l; 132 } 133 return x; 134 } 135 136 int 137 rn_refines(void* m_arg, void *n_arg) 138 { 139 caddr_t m = m_arg, n = n_arg; 140 caddr_t lim, lim2 = lim = n + *(u_char *)n; 141 int longer = (*(u_char *)n++) - (int)(*(u_char *)m++); 142 int masks_are_equal = 1; 143 144 if (longer > 0) 145 lim -= longer; 146 while (n < lim) { 147 if (*n & ~(*m)) 148 return 0; 149 if (*n++ != *m++) 150 masks_are_equal = 0; 151 } 152 while (n < lim2) 153 if (*n++) 154 return 0; 155 if (masks_are_equal && (longer < 0)) 156 for (lim2 = m - longer; m < lim2; ) 157 if (*m++) 158 return 1; 159 return (!masks_are_equal); 160 } 161 162 struct radix_node * 163 rn_lookup(void *v_arg, void *m_arg, struct radix_node_head *head) 164 { 165 struct radix_node *x; 166 caddr_t netmask = 0; 167 168 if (m_arg) { 169 if ((x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_off)) == 0) 170 return (0); 171 netmask = x->rn_key; 172 } 173 x = rn_match(v_arg, head); 174 if (x && netmask) { 175 while (x && x->rn_mask != netmask) 176 x = x->rn_dupedkey; 177 } 178 return x; 179 } 180 181 static int 182 rn_satisfies_leaf(char *trial, 183 struct radix_node *leaf, 184 int skip) 185 { 186 char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask; 187 char *cplim; 188 int length = min(*(u_char *)cp, *(u_char *)cp2); 189 190 if (cp3 == 0) 191 cp3 = rn_ones; 192 else 193 length = min(length, *(u_char *)cp3); 194 cplim = cp + length; cp3 += skip; cp2 += skip; 195 for (cp += skip; cp < cplim; cp++, cp2++, cp3++) 196 if ((*cp ^ *cp2) & *cp3) 197 return 0; 198 return 1; 199 } 200 201 struct radix_node * 202 rn_match(void *v_arg, 203 struct radix_node_head *head) 204 { 205 caddr_t v = v_arg; 206 struct radix_node *t = head->rnh_treetop, *x; 207 caddr_t cp = v, cp2; 208 caddr_t cplim; 209 struct radix_node *saved_t, *top = t; 210 int off = t->rn_off, vlen = *(u_char *)cp, matched_off; 211 int test, b, rn_b; 212 213 /* 214 * Open code rn_search(v, top) to avoid overhead of extra 215 * subroutine call. 216 */ 217 for (; t->rn_b >= 0; ) { 218 if (t->rn_bmask & cp[t->rn_off]) 219 t = t->rn_r; 220 else 221 t = t->rn_l; 222 } 223 /* 224 * See if we match exactly as a host destination 225 * or at least learn how many bits match, for normal mask finesse. 226 * 227 * It doesn't hurt us to limit how many bytes to check 228 * to the length of the mask, since if it matches we had a genuine 229 * match and the leaf we have is the most specific one anyway; 230 * if it didn't match with a shorter length it would fail 231 * with a long one. This wins big for class B&C netmasks which 232 * are probably the most common case... 233 */ 234 if (t->rn_mask) 235 vlen = *(u_char *)t->rn_mask; 236 cp += off; cp2 = t->rn_key + off; cplim = v + vlen; 237 for (; cp < cplim; cp++, cp2++) 238 if (*cp != *cp2) 239 goto on1; 240 /* 241 * This extra grot is in case we are explicitly asked 242 * to look up the default. Ugh! 243 * Or 255.255.255.255 244 * 245 * In this case, we have a complete match of the key. Unless 246 * the node is one of the roots, we are finished. 247 * If it is the zeros root, then take what we have, prefering 248 * any real data. 249 * If it is the ones root, then pretend the target key was followed 250 * by a byte of zeros. 251 */ 252 if (!(t->rn_flags & RNF_ROOT)) 253 return t; /* not a root */ 254 if (t->rn_dupedkey) { 255 t = t->rn_dupedkey; 256 return t; /* have some real data */ 257 } 258 if (*(cp-1) == 0) 259 return t; /* not the ones root */ 260 b = 0; /* fake a zero after 255.255.255.255 */ 261 goto on2; 262 on1: 263 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */ 264 for (b = 7; (test >>= 1) > 0;) 265 b--; 266 on2: 267 matched_off = cp - v; 268 b += matched_off << 3; 269 rn_b = -1 - b; 270 /* 271 * If there is a host route in a duped-key chain, it will be first. 272 */ 273 if ((saved_t = t)->rn_mask == 0) 274 t = t->rn_dupedkey; 275 for (; t; t = t->rn_dupedkey) { 276 /* 277 * Even if we don't match exactly as a host, 278 * we may match if the leaf we wound up at is 279 * a route to a net. 280 */ 281 if (t->rn_flags & RNF_NORMAL) { 282 if (rn_b <= t->rn_b) 283 return t; 284 } else if (rn_satisfies_leaf(v, t, matched_off)) { 285 return t; 286 } 287 } 288 t = saved_t; 289 /* start searching up the tree */ 290 do { 291 struct radix_mask *m; 292 t = t->rn_p; 293 if ((m = t->rn_mklist)) { 294 /* 295 * If non-contiguous masks ever become important 296 * we can restore the masking and open coding of 297 * the search and satisfaction test and put the 298 * calculation of "off" back before the "do". 299 */ 300 do { 301 if (m->rm_flags & RNF_NORMAL) { 302 if (rn_b <= m->rm_b) 303 return (m->rm_leaf); 304 } else { 305 off = min(t->rn_off, matched_off); 306 x = rn_search_m(v, t, m->rm_mask); 307 while (x && x->rn_mask != m->rm_mask) 308 x = x->rn_dupedkey; 309 if (x && rn_satisfies_leaf(v, x, off)) 310 return x; 311 } 312 } while ((m = m->rm_mklist)); 313 } 314 } while (t != top); 315 return 0; 316 } 317 318 #ifdef RN_DEBUG 319 int rn_nodenum; 320 struct radix_node *rn_clist; 321 int rn_saveinfo; 322 int rn_debug = 1; 323 #endif 324 325 struct radix_node * 326 rn_newpair(void *v, int b, struct radix_node nodes[2]) 327 { 328 struct radix_node *tt = nodes, *t = tt + 1; 329 t->rn_b = b; t->rn_bmask = 0x80 >> (b & 7); 330 t->rn_l = tt; t->rn_off = b >> 3; 331 tt->rn_b = -1; tt->rn_key = (caddr_t)v; tt->rn_p = t; 332 tt->rn_flags = t->rn_flags = RNF_ACTIVE; 333 #ifdef RN_DEBUG 334 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 335 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 336 #endif 337 return t; 338 } 339 340 struct radix_node * 341 rn_insert(void* v_arg, 342 struct radix_node_head *head, 343 int *dupentry, 344 struct radix_node nodes[2]) 345 { 346 caddr_t v = v_arg; 347 struct radix_node *top = head->rnh_treetop; 348 int head_off = top->rn_off, vlen = (int)*((u_char *)v); 349 struct radix_node *t = rn_search(v_arg, top); 350 caddr_t cp = v + head_off; 351 int b; 352 struct radix_node *tt; 353 354 /* 355 * Find first bit at which v and t->rn_key differ 356 */ 357 { 358 caddr_t cp2 = t->rn_key + head_off; 359 int cmp_res; 360 caddr_t cplim = v + vlen; 361 362 while (cp < cplim) 363 if (*cp2++ != *cp++) 364 goto on1; 365 /* handle adding 255.255.255.255 */ 366 if (!(t->rn_flags & RNF_ROOT) || *(cp2-1) == 0) { 367 *dupentry = 1; 368 return t; 369 } 370 on1: 371 *dupentry = 0; 372 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff; 373 for (b = (cp - v) << 3; cmp_res; b--) 374 cmp_res >>= 1; 375 } 376 { 377 struct radix_node *p, *x = top; 378 cp = v; 379 do { 380 p = x; 381 if (cp[x->rn_off] & x->rn_bmask) 382 x = x->rn_r; 383 else x = x->rn_l; 384 } while ((unsigned)b > (unsigned)x->rn_b); 385 #ifdef RN_DEBUG 386 if (rn_debug) 387 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p); 388 #endif 389 t = rn_newpair(v_arg, b, nodes); tt = t->rn_l; 390 if ((cp[p->rn_off] & p->rn_bmask) == 0) 391 p->rn_l = t; 392 else 393 p->rn_r = t; 394 x->rn_p = t; t->rn_p = p; /* frees x, p as temp vars below */ 395 if ((cp[t->rn_off] & t->rn_bmask) == 0) { 396 t->rn_r = x; 397 } else { 398 t->rn_r = tt; t->rn_l = x; 399 } 400 #ifdef RN_DEBUG 401 if (rn_debug) 402 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p); 403 #endif 404 } 405 return (tt); 406 } 407 408 struct radix_node * 409 rn_addmask(void *n_arg, int search, int skip) 410 { 411 caddr_t netmask = (caddr_t)n_arg; 412 struct radix_node *x; 413 caddr_t cp, cplim; 414 int b = 0, mlen, j; 415 int maskduplicated, m0, isnormal; 416 struct radix_node *saved_x; 417 static int last_zeroed = 0; 418 419 if ((mlen = *(u_char *)netmask) > max_keylen) 420 mlen = max_keylen; 421 if (skip == 0) 422 skip = 1; 423 if (mlen <= skip) 424 return (mask_rnhead->rnh_nodes); 425 if (skip > 1) 426 Bcopy(rn_ones + 1, addmask_key + 1, skip - 1); 427 if ((m0 = mlen) > skip) 428 Bcopy(netmask + skip, addmask_key + skip, mlen - skip); 429 /* 430 * Trim trailing zeroes. 431 */ 432 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;) 433 cp--; 434 mlen = cp - addmask_key; 435 if (mlen <= skip) { 436 if (m0 >= last_zeroed) 437 last_zeroed = mlen; 438 return (mask_rnhead->rnh_nodes); 439 } 440 if (m0 < last_zeroed) 441 Bzero(addmask_key + m0, last_zeroed - m0); 442 *addmask_key = last_zeroed = mlen; 443 x = rn_search(addmask_key, rn_masktop); 444 if (Bcmp(addmask_key, x->rn_key, mlen) != 0) 445 x = 0; 446 if (x || search) 447 return (x); 448 x = (struct radix_node *)rtmalloc(max_keylen + 2*sizeof(*x), 449 "rn_addmask"); 450 saved_x = x; 451 Bzero(x, max_keylen + 2 * sizeof (*x)); 452 netmask = cp = (caddr_t)(x + 2); 453 Bcopy(addmask_key, cp, mlen); 454 x = rn_insert(cp, mask_rnhead, &maskduplicated, x); 455 if (maskduplicated) { 456 log(LOG_ERR, "rn_addmask: mask impossibly already in tree"); 457 Free(saved_x); 458 return (x); 459 } 460 /* 461 * Calculate index of mask, and check for normalcy. 462 */ 463 cplim = netmask + mlen; isnormal = 1; 464 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;) 465 cp++; 466 if (cp != cplim) { 467 for (j = 0x80; (j & *cp) != 0; j >>= 1) 468 b++; 469 if (*cp != normal_chars[b] || cp != (cplim - 1)) 470 isnormal = 0; 471 } 472 b += (cp - netmask) << 3; 473 x->rn_b = -1 - b; 474 if (isnormal) 475 x->rn_flags |= RNF_NORMAL; 476 return (x); 477 } 478 479 static int /* XXX: arbitrary ordering for non-contiguous masks */ 480 rn_lexobetter(void *m_arg, void *n_arg) 481 { 482 u_char *mp = m_arg, *np = n_arg, *lim; 483 484 if (*mp > *np) 485 return 1; /* not really, but need to check longer one first */ 486 if (*mp == *np) 487 for (lim = mp + *mp; mp < lim;) 488 if (*mp++ > *np++) 489 return 1; 490 return 0; 491 } 492 493 static struct radix_mask * 494 rn_new_radix_mask(struct radix_node *tt, 495 struct radix_mask *next) 496 { 497 struct radix_mask *m; 498 499 MKGet(m); 500 if (m == 0) { 501 log(LOG_ERR, "Mask for route not entered\n"); 502 return (0); 503 } 504 Bzero(m, sizeof *m); 505 m->rm_b = tt->rn_b; 506 m->rm_flags = tt->rn_flags; 507 if (tt->rn_flags & RNF_NORMAL) 508 m->rm_leaf = tt; 509 else 510 m->rm_mask = tt->rn_mask; 511 m->rm_mklist = next; 512 tt->rn_mklist = m; 513 return m; 514 } 515 516 struct radix_node * 517 rn_addroute(void *v_arg, 518 void *n_arg, 519 struct radix_node_head *head, 520 struct radix_node treenodes[2]) 521 { 522 caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg; 523 struct radix_node *t, *x = 0, *tt; 524 struct radix_node *saved_tt, *top = head->rnh_treetop; 525 short b = 0, b_leaf = 0; 526 int keyduplicated; 527 caddr_t mmask; 528 struct radix_mask *m, **mp; 529 530 /* 531 * In dealing with non-contiguous masks, there may be 532 * many different routes which have the same mask. 533 * We will find it useful to have a unique pointer to 534 * the mask to speed avoiding duplicate references at 535 * nodes and possibly save time in calculating indices. 536 */ 537 if (netmask) { 538 if ((x = rn_addmask(netmask, 0, top->rn_off)) == 0) 539 return (0); 540 b_leaf = x->rn_b; 541 b = -1 - x->rn_b; 542 netmask = x->rn_key; 543 } 544 /* 545 * Deal with duplicated keys: attach node to previous instance 546 */ 547 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes); 548 if (keyduplicated) { 549 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) { 550 if (tt->rn_mask == netmask) 551 return (0); 552 if (netmask == 0 || 553 (tt->rn_mask && 554 ((b_leaf < tt->rn_b) || /* index(netmask) > node */ 555 rn_refines(netmask, tt->rn_mask) || 556 rn_lexobetter(netmask, tt->rn_mask)))) 557 break; 558 } 559 /* 560 * If the mask is not duplicated, we wouldn't 561 * find it among possible duplicate key entries 562 * anyway, so the above test doesn't hurt. 563 * 564 * We sort the masks for a duplicated key the same way as 565 * in a masklist -- most specific to least specific. 566 * This may require the unfortunate nuisance of relocating 567 * the head of the list. 568 */ 569 if (tt == saved_tt) { 570 struct radix_node *xx = x; 571 /* link in at head of list */ 572 (tt = treenodes)->rn_dupedkey = t; 573 tt->rn_flags = t->rn_flags; 574 tt->rn_p = x = t->rn_p; 575 if (x->rn_l == t) x->rn_l = tt; else x->rn_r = tt; 576 saved_tt = tt; x = xx; 577 } else { 578 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey; 579 t->rn_dupedkey = tt; 580 } 581 #ifdef RN_DEBUG 582 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 583 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 584 #endif 585 tt->rn_key = (caddr_t) v; 586 tt->rn_b = -1; 587 tt->rn_flags = RNF_ACTIVE; 588 } 589 /* 590 * Put mask in tree. 591 */ 592 if (netmask) { 593 tt->rn_mask = netmask; 594 tt->rn_b = x->rn_b; 595 tt->rn_flags |= x->rn_flags & RNF_NORMAL; 596 } 597 t = saved_tt->rn_p; 598 if (keyduplicated) 599 goto on2; 600 b_leaf = -1 - t->rn_b; 601 if (t->rn_r == saved_tt) x = t->rn_l; else x = t->rn_r; 602 /* Promote general routes from below */ 603 if (x->rn_b < 0) { 604 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey) 605 if (x->rn_mask && (x->rn_b >= b_leaf) && x->rn_mklist == 0) { 606 if ((*mp = m = rn_new_radix_mask(x, 0))) 607 mp = &m->rm_mklist; 608 } 609 } else if (x->rn_mklist) { 610 /* 611 * Skip over masks whose index is > that of new node 612 */ 613 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 614 if (m->rm_b >= b_leaf) 615 break; 616 t->rn_mklist = m; *mp = 0; 617 } 618 on2: 619 /* Add new route to highest possible ancestor's list */ 620 if ((netmask == 0) || (b > t->rn_b )) 621 return tt; /* can't lift at all */ 622 b_leaf = tt->rn_b; 623 do { 624 x = t; 625 t = t->rn_p; 626 } while (b <= t->rn_b && x != top); 627 /* 628 * Search through routes associated with node to 629 * insert new route according to index. 630 * Need same criteria as when sorting dupedkeys to avoid 631 * double loop on deletion. 632 */ 633 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) { 634 if (m->rm_b < b_leaf) 635 continue; 636 if (m->rm_b > b_leaf) 637 break; 638 if (m->rm_flags & RNF_NORMAL) { 639 mmask = m->rm_leaf->rn_mask; 640 if (tt->rn_flags & RNF_NORMAL) { 641 log(LOG_ERR, 642 "Non-unique normal route, mask not entered"); 643 return tt; 644 } 645 } else 646 mmask = m->rm_mask; 647 if (mmask == netmask) { 648 m->rm_refs++; 649 tt->rn_mklist = m; 650 return tt; 651 } 652 if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask)) 653 break; 654 } 655 *mp = rn_new_radix_mask(tt, *mp); 656 return tt; 657 } 658 659 struct radix_node * 660 rn_delete(void *v_arg, 661 void *netmask_arg, 662 struct radix_node_head *head) 663 { 664 struct radix_node *t, *p, *x, *tt; 665 struct radix_mask *m, *saved_m, **mp; 666 struct radix_node *dupedkey, *saved_tt, *top; 667 caddr_t v, netmask; 668 int b, head_off, vlen; 669 670 v = v_arg; 671 netmask = netmask_arg; 672 x = head->rnh_treetop; 673 tt = rn_search(v, x); 674 head_off = x->rn_off; 675 vlen = *(u_char *)v; 676 saved_tt = tt; 677 top = x; 678 if (tt == 0 || 679 Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off)) 680 return (0); 681 /* 682 * Delete our route from mask lists. 683 */ 684 if (netmask) { 685 if ((x = rn_addmask(netmask, 1, head_off)) == 0) 686 return (0); 687 netmask = x->rn_key; 688 while (tt->rn_mask != netmask) 689 if ((tt = tt->rn_dupedkey) == 0) 690 return (0); 691 } 692 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0) 693 goto on1; 694 if (tt->rn_flags & RNF_NORMAL) { 695 if (m->rm_leaf != tt || m->rm_refs > 0) { 696 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 697 return 0; /* dangling ref could cause disaster */ 698 } 699 } else { 700 if (m->rm_mask != tt->rn_mask) { 701 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 702 goto on1; 703 } 704 if (--m->rm_refs >= 0) 705 goto on1; 706 } 707 b = -1 - tt->rn_b; 708 t = saved_tt->rn_p; 709 if (b > t->rn_b) 710 goto on1; /* Wasn't lifted at all */ 711 do { 712 x = t; 713 t = t->rn_p; 714 } while (b <= t->rn_b && x != top); 715 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 716 if (m == saved_m) { 717 *mp = m->rm_mklist; 718 MKFree(m); 719 break; 720 } 721 if (m == 0) { 722 log(LOG_ERR, "rn_delete: couldn't find our annotation\n"); 723 if (tt->rn_flags & RNF_NORMAL) 724 return (0); /* Dangling ref to us */ 725 } 726 on1: 727 /* 728 * Eliminate us from tree 729 */ 730 if (tt->rn_flags & RNF_ROOT) 731 return (0); 732 #ifdef RN_DEBUG 733 /* Get us out of the creation list */ 734 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {} 735 if (t) t->rn_ybro = tt->rn_ybro; 736 #endif 737 t = tt->rn_p; 738 if ((dupedkey = saved_tt->rn_dupedkey)) { 739 if (tt == saved_tt) { 740 x = dupedkey; x->rn_p = t; 741 if (t->rn_l == tt) t->rn_l = x; else t->rn_r = x; 742 } else { 743 for (x = p = saved_tt; p && p->rn_dupedkey != tt;) 744 p = p->rn_dupedkey; 745 if (p) p->rn_dupedkey = tt->rn_dupedkey; 746 else log(LOG_ERR, "rn_delete: couldn't find us\n"); 747 } 748 t = tt + 1; 749 if (t->rn_flags & RNF_ACTIVE) { 750 #ifndef RN_DEBUG 751 *++x = *t; p = t->rn_p; 752 #else 753 b = t->rn_info; *++x = *t; t->rn_info = b; p = t->rn_p; 754 #endif 755 if (p->rn_l == t) p->rn_l = x; else p->rn_r = x; 756 x->rn_l->rn_p = x; x->rn_r->rn_p = x; 757 } 758 goto out; 759 } 760 if (t->rn_l == tt) x = t->rn_r; else x = t->rn_l; 761 p = t->rn_p; 762 if (p->rn_r == t) p->rn_r = x; else p->rn_l = x; 763 x->rn_p = p; 764 /* 765 * Demote routes attached to us. 766 */ 767 if (t->rn_mklist) { 768 if (x->rn_b >= 0) { 769 for (mp = &x->rn_mklist; (m = *mp);) 770 mp = &m->rm_mklist; 771 *mp = t->rn_mklist; 772 } else { 773 /* If there are any key,mask pairs in a sibling 774 duped-key chain, some subset will appear sorted 775 in the same order attached to our mklist */ 776 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey) 777 if (m == x->rn_mklist) { 778 struct radix_mask *mm = m->rm_mklist; 779 x->rn_mklist = 0; 780 if (--(m->rm_refs) < 0) 781 MKFree(m); 782 m = mm; 783 } 784 if (m) 785 syslog(LOG_ERR, "%s 0x%lx at 0x%lx\n", 786 "rn_delete: Orphaned Mask", 787 (unsigned long)m, 788 (unsigned long)x); 789 } 790 } 791 /* 792 * We may be holding an active internal node in the tree. 793 */ 794 x = tt + 1; 795 if (t != x) { 796 #ifndef RN_DEBUG 797 *t = *x; 798 #else 799 b = t->rn_info; *t = *x; t->rn_info = b; 800 #endif 801 t->rn_l->rn_p = t; t->rn_r->rn_p = t; 802 p = x->rn_p; 803 if (p->rn_l == x) p->rn_l = t; else p->rn_r = t; 804 } 805 out: 806 tt->rn_flags &= ~RNF_ACTIVE; 807 tt[1].rn_flags &= ~RNF_ACTIVE; 808 return (tt); 809 } 810 811 int 812 rn_walktree(struct radix_node_head *h, 813 int (*f)(struct radix_node *, struct walkarg *), 814 struct walkarg *w) 815 { 816 int error; 817 struct radix_node *base, *next; 818 struct radix_node *rn = h->rnh_treetop; 819 /* 820 * This gets complicated because we may delete the node 821 * while applying the function f to it, so we need to calculate 822 * the successor node in advance. 823 */ 824 /* First time through node, go left */ 825 while (rn->rn_b >= 0) 826 rn = rn->rn_l; 827 for (;;) { 828 base = rn; 829 /* If at right child go back up, otherwise, go right */ 830 while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0) 831 rn = rn->rn_p; 832 /* Find the next *leaf* since next node might vanish, too */ 833 for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;) 834 rn = rn->rn_l; 835 next = rn; 836 /* Process leaves */ 837 while ((rn = base)) { 838 base = rn->rn_dupedkey; 839 if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w))) 840 return (error); 841 } 842 rn = next; 843 if (rn->rn_flags & RNF_ROOT) 844 return (0); 845 } 846 /* NOTREACHED */ 847 } 848 849 int 850 rn_inithead(void **head, int off) 851 { 852 struct radix_node_head *rnh; 853 struct radix_node *t, *tt, *ttt; 854 if (*head) 855 return (1); 856 rnh = (struct radix_node_head *)rtmalloc(sizeof(*rnh), "rn_inithead"); 857 Bzero(rnh, sizeof (*rnh)); 858 *head = rnh; 859 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes); 860 ttt = rnh->rnh_nodes + 2; 861 t->rn_r = ttt; 862 t->rn_p = t; 863 tt = t->rn_l; 864 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE; 865 tt->rn_b = -1 - off; 866 *ttt = *tt; 867 ttt->rn_key = rn_ones; 868 rnh->rnh_addaddr = rn_addroute; 869 rnh->rnh_deladdr = rn_delete; 870 rnh->rnh_matchaddr = rn_match; 871 rnh->rnh_lookup = rn_lookup; 872 rnh->rnh_walktree = rn_walktree; 873 rnh->rnh_treetop = t; 874 return (1); 875 } 876 877 void 878 rn_init(void) 879 { 880 char *cp, *cplim; 881 if (max_keylen == 0) { 882 printf("rn_init: radix functions require max_keylen be set\n"); 883 return; 884 } 885 rn_zeros = (char *)rtmalloc(3 * max_keylen, "rn_init"); 886 Bzero(rn_zeros, 3 * max_keylen); 887 rn_ones = cp = rn_zeros + max_keylen; 888 addmask_key = cplim = rn_ones + max_keylen; 889 while (cp < cplim) 890 *cp++ = -1; 891 if (rn_inithead((void **)&mask_rnhead, 0) == 0) 892 panic("rn_init 2"); 893 } 894 895