1 /* $OpenBSD: radix.c,v 1.10 2003/06/02 23:28:12 millert Exp $ */ 2 /* $NetBSD: radix.c,v 1.11 1996/03/16 23:55:36 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1988, 1989, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)radix.c 8.4 (Berkeley) 11/2/94 33 */ 34 35 /* 36 * Routines to build and maintain radix trees for routing lookups. 37 */ 38 #include <sys/param.h> 39 #ifdef _KERNEL 40 #include <sys/systm.h> 41 #include <sys/malloc.h> 42 #define M_DONTWAIT M_NOWAIT 43 #include <sys/domain.h> 44 #else 45 #include <stdlib.h> 46 #include <stdlib.h> 47 #include <string.h> 48 #endif 49 #include <sys/syslog.h> 50 #include <net/radix.h> 51 52 int max_keylen; 53 struct radix_mask *rn_mkfreelist; 54 struct radix_node_head *mask_rnhead; 55 static char *addmask_key; 56 static char normal_chars[] = {0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1}; 57 static char *rn_zeros, *rn_ones; 58 59 #define rn_masktop (mask_rnhead->rnh_treetop) 60 #undef Bcmp 61 #define Bcmp(a, b, l) (l == 0 ? 0 : bcmp((caddr_t)(a), (caddr_t)(b), (u_long)l)) 62 63 64 static int rn_satsifies_leaf(char *, struct radix_node *, int); 65 static int rn_lexobetter(void *, void *); 66 static struct radix_mask *rn_new_radix_mask(struct radix_node *, 67 struct radix_mask *); 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(v_arg, head) 104 void *v_arg; 105 struct radix_node *head; 106 { 107 register struct radix_node *x; 108 register caddr_t v; 109 110 for (x = head, v = v_arg; x->rn_b >= 0;) { 111 if (x->rn_bmask & v[x->rn_off]) 112 x = x->rn_r; 113 else 114 x = x->rn_l; 115 } 116 return (x); 117 } 118 119 struct radix_node * 120 rn_search_m(v_arg, head, m_arg) 121 struct radix_node *head; 122 void *v_arg, *m_arg; 123 { 124 register struct radix_node *x; 125 register caddr_t v = v_arg, m = m_arg; 126 127 for (x = head; x->rn_b >= 0;) { 128 if ((x->rn_bmask & m[x->rn_off]) && 129 (x->rn_bmask & v[x->rn_off])) 130 x = x->rn_r; 131 else 132 x = x->rn_l; 133 } 134 return x; 135 } 136 137 int 138 rn_refines(m_arg, n_arg) 139 void *m_arg, *n_arg; 140 { 141 register caddr_t m = m_arg, n = n_arg; 142 register caddr_t lim, lim2 = lim = n + *(u_char *)n; 143 int longer = (*(u_char *)n++) - (int)(*(u_char *)m++); 144 int masks_are_equal = 1; 145 146 if (longer > 0) 147 lim -= longer; 148 while (n < lim) { 149 if (*n & ~(*m)) 150 return 0; 151 if (*n++ != *m++) 152 masks_are_equal = 0; 153 } 154 while (n < lim2) 155 if (*n++) 156 return 0; 157 if (masks_are_equal && (longer < 0)) 158 for (lim2 = m - longer; m < lim2; ) 159 if (*m++) 160 return 1; 161 return (!masks_are_equal); 162 } 163 164 struct radix_node * 165 rn_lookup(v_arg, m_arg, head) 166 void *v_arg, *m_arg; 167 struct radix_node_head *head; 168 { 169 register struct radix_node *x; 170 caddr_t netmask = 0; 171 172 if (m_arg) { 173 if ((x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_off)) == 0) 174 return (0); 175 netmask = x->rn_key; 176 } 177 x = rn_match(v_arg, head); 178 if (x && netmask) { 179 while (x && x->rn_mask != netmask) 180 x = x->rn_dupedkey; 181 } 182 return x; 183 } 184 185 static int 186 rn_satsifies_leaf(trial, leaf, skip) 187 char *trial; 188 register struct radix_node *leaf; 189 int skip; 190 { 191 register char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask; 192 char *cplim; 193 int length = min(*(u_char *)cp, *(u_char *)cp2); 194 195 if (cp3 == 0) 196 cp3 = rn_ones; 197 else 198 length = min(length, *(u_char *)cp3); 199 cplim = cp + length; cp3 += skip; cp2 += skip; 200 for (cp += skip; cp < cplim; cp++, cp2++, cp3++) 201 if ((*cp ^ *cp2) & *cp3) 202 return 0; 203 return 1; 204 } 205 206 struct radix_node * 207 rn_match(v_arg, head) 208 void *v_arg; 209 struct radix_node_head *head; 210 { 211 caddr_t v = v_arg; 212 register struct radix_node *t = head->rnh_treetop, *x; 213 register caddr_t cp = v, cp2; 214 caddr_t cplim; 215 struct radix_node *saved_t, *top = t; 216 int off = t->rn_off, vlen = *(u_char *)cp, matched_off; 217 register int test, b, rn_b; 218 219 /* 220 * Open code rn_search(v, top) to avoid overhead of extra 221 * subroutine call. 222 */ 223 for (; t->rn_b >= 0; ) { 224 if (t->rn_bmask & cp[t->rn_off]) 225 t = t->rn_r; 226 else 227 t = t->rn_l; 228 } 229 /* 230 * See if we match exactly as a host destination 231 * or at least learn how many bits match, for normal mask finesse. 232 * 233 * It doesn't hurt us to limit how many bytes to check 234 * to the length of the mask, since if it matches we had a genuine 235 * match and the leaf we have is the most specific one anyway; 236 * if it didn't match with a shorter length it would fail 237 * with a long one. This wins big for class B&C netmasks which 238 * are probably the most common case... 239 */ 240 if (t->rn_mask) 241 vlen = *(u_char *)t->rn_mask; 242 cp += off; cp2 = t->rn_key + off; cplim = v + vlen; 243 for (; cp < cplim; cp++, cp2++) 244 if (*cp != *cp2) 245 goto on1; 246 /* 247 * This extra grot is in case we are explicitly asked 248 * to look up the default. Ugh! 249 */ 250 if ((t->rn_flags & RNF_ROOT) && t->rn_dupedkey) 251 t = t->rn_dupedkey; 252 return t; 253 on1: 254 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */ 255 for (b = 7; (test >>= 1) > 0;) 256 b--; 257 matched_off = cp - v; 258 b += matched_off << 3; 259 rn_b = -1 - b; 260 /* 261 * If there is a host route in a duped-key chain, it will be first. 262 */ 263 if ((saved_t = t)->rn_mask == 0) 264 t = t->rn_dupedkey; 265 for (; t && !(t->rn_flags & RNF_IGNORE); t = t->rn_dupedkey) 266 /* 267 * Even if we don't match exactly as a host, 268 * we may match if the leaf we wound up at is 269 * a route to a net. 270 */ 271 if (t->rn_flags & RNF_NORMAL) { 272 if (rn_b <= t->rn_b) 273 return t; 274 } else if (rn_satsifies_leaf(v, t, matched_off)) 275 return t; 276 t = saved_t; 277 /* start searching up the tree */ 278 do { 279 register struct radix_mask *m; 280 t = t->rn_p; 281 if ((m = t->rn_mklist) != NULL) { 282 /* 283 * If non-contiguous masks ever become important 284 * we can restore the masking and open coding of 285 * the search and satisfaction test and put the 286 * calculation of "off" back before the "do". 287 */ 288 do { 289 if (m->rm_flags & RNF_NORMAL) { 290 if (rn_b <= m->rm_b && 291 !(m->rm_flags & RNF_IGNORE)) 292 return (m->rm_leaf); 293 } else { 294 off = min(t->rn_off, matched_off); 295 x = rn_search_m(v, t, m->rm_mask); 296 while (x && x->rn_mask != m->rm_mask) 297 x = x->rn_dupedkey; 298 if (x && !(x->rn_flags & RNF_IGNORE) && 299 rn_satsifies_leaf(v, x, off)) 300 return x; 301 } 302 } while ((m = m->rm_mklist) != NULL); 303 } 304 } while (t != top); 305 return 0; 306 } 307 308 #ifdef RN_DEBUG 309 int rn_nodenum; 310 struct radix_node *rn_clist; 311 int rn_saveinfo; 312 int rn_debug = 1; 313 #endif 314 315 struct radix_node * 316 rn_newpair(v, b, nodes) 317 void *v; 318 int b; 319 struct radix_node nodes[2]; 320 { 321 register struct radix_node *tt = nodes, *t = tt + 1; 322 t->rn_b = b; 323 t->rn_bmask = 0x80 >> (b & 7); 324 t->rn_l = tt; 325 t->rn_off = b >> 3; 326 tt->rn_b = -1; 327 tt->rn_key = (caddr_t)v; 328 tt->rn_p = t; 329 tt->rn_flags = t->rn_flags = RNF_ACTIVE; 330 #ifdef RN_DEBUG 331 tt->rn_info = rn_nodenum++; 332 t->rn_info = rn_nodenum++; 333 tt->rn_twin = t; 334 tt->rn_ybro = rn_clist; 335 rn_clist = tt; 336 #endif 337 return t; 338 } 339 340 struct radix_node * 341 rn_insert(v_arg, head, dupentry, nodes) 342 void *v_arg; 343 struct radix_node_head *head; 344 int *dupentry; 345 struct radix_node nodes[2]; 346 { 347 caddr_t v = v_arg; 348 struct radix_node *top = head->rnh_treetop; 349 int head_off = top->rn_off, vlen = (int)*((u_char *)v); 350 register struct radix_node *t = rn_search(v_arg, top); 351 register caddr_t cp = v + head_off; 352 register int b; 353 struct radix_node *tt; 354 /* 355 * Find first bit at which v and t->rn_key differ 356 */ 357 { 358 register caddr_t cp2 = t->rn_key + head_off; 359 register int cmp_res; 360 caddr_t cplim = v + vlen; 361 362 while (cp < cplim) 363 if (*cp2++ != *cp++) 364 goto on1; 365 *dupentry = 1; 366 return t; 367 on1: 368 *dupentry = 0; 369 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff; 370 for (b = (cp - v) << 3; cmp_res; b--) 371 cmp_res >>= 1; 372 } 373 { 374 register struct radix_node *p, *x = top; 375 cp = v; 376 do { 377 p = x; 378 if (cp[x->rn_off] & x->rn_bmask) 379 x = x->rn_r; 380 else 381 x = x->rn_l; 382 } while (b > (unsigned) x->rn_b); /* x->rn_b < b && x->rn_b >= 0 */ 383 #ifdef RN_DEBUG 384 if (rn_debug) 385 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p); 386 #endif 387 t = rn_newpair(v_arg, b, nodes); 388 tt = t->rn_l; 389 if ((cp[p->rn_off] & p->rn_bmask) == 0) 390 p->rn_l = t; 391 else 392 p->rn_r = t; 393 x->rn_p = t; 394 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; 399 t->rn_l = x; 400 } 401 #ifdef RN_DEBUG 402 if (rn_debug) 403 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p); 404 #endif 405 } 406 return (tt); 407 } 408 409 struct radix_node * 410 rn_addmask(n_arg, search, skip) 411 int search, skip; 412 void *n_arg; 413 { 414 caddr_t netmask = (caddr_t)n_arg; 415 register struct radix_node *x; 416 register caddr_t cp, cplim; 417 register int b = 0, mlen, j; 418 int maskduplicated, m0, isnormal; 419 struct radix_node *saved_x; 420 static int last_zeroed = 0; 421 422 if ((mlen = *(u_char *)netmask) > max_keylen) 423 mlen = max_keylen; 424 if (skip == 0) 425 skip = 1; 426 if (mlen <= skip) 427 return (mask_rnhead->rnh_nodes); 428 if (skip > 1) 429 Bcopy(rn_ones + 1, addmask_key + 1, skip - 1); 430 if ((m0 = mlen) > skip) 431 Bcopy(netmask + skip, addmask_key + skip, mlen - skip); 432 /* 433 * Trim trailing zeroes. 434 */ 435 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;) 436 cp--; 437 mlen = cp - addmask_key; 438 if (mlen <= skip) { 439 if (m0 >= last_zeroed) 440 last_zeroed = mlen; 441 return (mask_rnhead->rnh_nodes); 442 } 443 if (m0 < last_zeroed) 444 Bzero(addmask_key + m0, last_zeroed - m0); 445 *addmask_key = last_zeroed = mlen; 446 x = rn_search(addmask_key, rn_masktop); 447 if (Bcmp(addmask_key, x->rn_key, mlen) != 0) 448 x = 0; 449 if (x || search) 450 return (x); 451 R_Malloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x)); 452 if ((saved_x = x) == 0) 453 return (0); 454 Bzero(x, max_keylen + 2 * sizeof (*x)); 455 netmask = cp = (caddr_t)(x + 2); 456 Bcopy(addmask_key, cp, mlen); 457 x = rn_insert(cp, mask_rnhead, &maskduplicated, x); 458 if (maskduplicated) { 459 log(LOG_ERR, "rn_addmask: mask impossibly already in tree"); 460 Free(saved_x); 461 return (x); 462 } 463 /* 464 * Calculate index of mask, and check for normalcy. 465 */ 466 cplim = netmask + mlen; 467 isnormal = 1; 468 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;) 469 cp++; 470 if (cp != cplim) { 471 for (j = 0x80; (j & *cp) != 0; j >>= 1) 472 b++; 473 if (*cp != normal_chars[b] || cp != (cplim - 1)) 474 isnormal = 0; 475 } 476 b += (cp - netmask) << 3; 477 x->rn_b = -1 - b; 478 if (isnormal) 479 x->rn_flags |= RNF_NORMAL; 480 return (x); 481 } 482 483 static int /* XXX: arbitrary ordering for non-contiguous masks */ 484 rn_lexobetter(m_arg, n_arg) 485 void *m_arg, *n_arg; 486 { 487 register u_char *mp = m_arg, *np = n_arg, *lim; 488 489 if (*mp > *np) 490 return 1; /* not really, but need to check longer one first */ 491 if (*mp == *np) 492 for (lim = mp + *mp; mp < lim;) 493 if (*mp++ > *np++) 494 return 1; 495 return 0; 496 } 497 498 static struct radix_mask * 499 rn_new_radix_mask(tt, next) 500 register struct radix_node *tt; 501 register struct radix_mask *next; 502 { 503 register struct radix_mask *m; 504 505 MKGet(m); 506 if (m == 0) { 507 log(LOG_ERR, "Mask for route not entered\n"); 508 return (0); 509 } 510 Bzero(m, sizeof *m); 511 m->rm_b = tt->rn_b; 512 m->rm_flags = tt->rn_flags; 513 if (tt->rn_flags & RNF_NORMAL) 514 m->rm_leaf = tt; 515 else 516 m->rm_mask = tt->rn_mask; 517 m->rm_mklist = next; 518 tt->rn_mklist = m; 519 return m; 520 } 521 522 struct radix_node * 523 rn_addroute(v_arg, n_arg, head, treenodes) 524 void *v_arg, *n_arg; 525 struct radix_node_head *head; 526 struct radix_node treenodes[2]; 527 { 528 caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg; 529 register struct radix_node *t, *x = NULL, *tt; 530 struct radix_node *saved_tt, *top = head->rnh_treetop; 531 short b = 0, b_leaf = 0; 532 int keyduplicated; 533 caddr_t mmask; 534 struct radix_mask *m, **mp; 535 536 /* 537 * In dealing with non-contiguous masks, there may be 538 * many different routes which have the same mask. 539 * We will find it useful to have a unique pointer to 540 * the mask to speed avoiding duplicate references at 541 * nodes and possibly save time in calculating indices. 542 */ 543 if (netmask) { 544 if ((x = rn_addmask(netmask, 0, top->rn_off)) == 0) 545 return (0); 546 b_leaf = x->rn_b; 547 b = -1 - x->rn_b; 548 netmask = x->rn_key; 549 } 550 /* 551 * Deal with duplicated keys: attach node to previous instance 552 */ 553 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes); 554 if (keyduplicated) { 555 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) { 556 if (tt->rn_mask == netmask) 557 return (0); 558 if (netmask == 0 || 559 (tt->rn_mask && 560 ((b_leaf < tt->rn_b) || /* index(netmask) > node */ 561 rn_refines(netmask, tt->rn_mask) || 562 rn_lexobetter(netmask, tt->rn_mask)))) 563 break; 564 } 565 /* 566 * If the mask is not duplicated, we wouldn't 567 * find it among possible duplicate key entries 568 * anyway, so the above test doesn't hurt. 569 * 570 * We sort the masks for a duplicated key the same way as 571 * in a masklist -- most specific to least specific. 572 * This may require the unfortunate nuisance of relocating 573 * the head of the list. 574 */ 575 if (tt == saved_tt) { 576 struct radix_node *xx = x; 577 /* link in at head of list */ 578 (tt = treenodes)->rn_dupedkey = t; 579 tt->rn_flags = t->rn_flags; 580 tt->rn_p = x = t->rn_p; 581 if (x->rn_l == t) 582 x->rn_l = tt; 583 else 584 x->rn_r = tt; 585 saved_tt = tt; 586 x = xx; 587 } else { 588 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey; 589 t->rn_dupedkey = tt; 590 } 591 #ifdef RN_DEBUG 592 t=tt+1; 593 tt->rn_info = rn_nodenum++; 594 t->rn_info = rn_nodenum++; 595 tt->rn_twin = t; 596 tt->rn_ybro = rn_clist; 597 rn_clist = tt; 598 #endif 599 tt->rn_key = (caddr_t) v; 600 tt->rn_b = -1; 601 tt->rn_flags = RNF_ACTIVE; 602 } 603 /* 604 * Put mask in tree. 605 */ 606 if (netmask) { 607 tt->rn_mask = netmask; 608 tt->rn_b = x->rn_b; 609 tt->rn_flags |= x->rn_flags & RNF_NORMAL; 610 } 611 t = saved_tt->rn_p; 612 if (keyduplicated) 613 goto on2; 614 b_leaf = -1 - t->rn_b; 615 if (t->rn_r == saved_tt) 616 x = t->rn_l; 617 else 618 x = t->rn_r; 619 /* Promote general routes from below */ 620 if (x->rn_b < 0) { 621 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey) 622 if (x->rn_mask && (x->rn_b >= b_leaf) && x->rn_mklist == 0) { 623 *mp = m = rn_new_radix_mask(x, 0); 624 if (m) 625 mp = &m->rm_mklist; 626 } 627 } else if (x->rn_mklist) { 628 /* 629 * Skip over masks whose index is > that of new node 630 */ 631 for (mp = &x->rn_mklist; (m = *mp) != NULL; mp = &m->rm_mklist) 632 if (m->rm_b >= b_leaf) 633 break; 634 t->rn_mklist = m; 635 *mp = 0; 636 } 637 on2: 638 /* Add new route to highest possible ancestor's list */ 639 if ((netmask == 0) || (b > t->rn_b )) 640 return tt; /* can't lift at all */ 641 b_leaf = tt->rn_b; 642 do { 643 x = t; 644 t = t->rn_p; 645 } while (b <= t->rn_b && x != top); 646 /* 647 * Search through routes associated with node to 648 * insert new route according to index. 649 * Need same criteria as when sorting dupedkeys to avoid 650 * double loop on deletion. 651 */ 652 for (mp = &x->rn_mklist; (m = *mp) != NULL; mp = &m->rm_mklist) { 653 if (m->rm_b < b_leaf) 654 continue; 655 if (m->rm_b > b_leaf) 656 break; 657 if (m->rm_flags & RNF_NORMAL) { 658 mmask = m->rm_leaf->rn_mask; 659 if (tt->rn_flags & RNF_NORMAL) { 660 log(LOG_ERR, "Non-unique normal route, " 661 "mask not entered\n"); 662 return tt; 663 } 664 } else 665 mmask = m->rm_mask; 666 if (mmask == netmask) { 667 m->rm_refs++; 668 tt->rn_mklist = m; 669 return tt; 670 } 671 if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask)) 672 break; 673 } 674 *mp = rn_new_radix_mask(tt, *mp); 675 return tt; 676 } 677 678 struct radix_node * 679 rn_delete(v_arg, netmask_arg, head) 680 void *v_arg, *netmask_arg; 681 struct radix_node_head *head; 682 { 683 register struct radix_node *t, *p, *x, *tt; 684 struct radix_mask *m, *saved_m, **mp; 685 struct radix_node *dupedkey, *saved_tt, *top; 686 caddr_t v, netmask; 687 int b, head_off, vlen; 688 689 v = v_arg; 690 netmask = netmask_arg; 691 x = head->rnh_treetop; 692 tt = rn_search(v, x); 693 head_off = x->rn_off; 694 vlen = *(u_char *)v; 695 saved_tt = tt; 696 top = x; 697 if (tt == 0 || 698 Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off)) 699 return (0); 700 /* 701 * Delete our route from mask lists. 702 */ 703 if (netmask) { 704 if ((x = rn_addmask(netmask, 1, head_off)) == 0) 705 return (0); 706 netmask = x->rn_key; 707 while (tt->rn_mask != netmask) 708 if ((tt = tt->rn_dupedkey) == 0) 709 return (0); 710 } 711 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0) 712 goto on1; 713 if (tt->rn_flags & RNF_NORMAL) { 714 if (m->rm_leaf != tt || m->rm_refs > 0) { 715 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 716 return 0; /* dangling ref could cause disaster */ 717 } 718 } else { 719 if (m->rm_mask != tt->rn_mask) { 720 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 721 goto on1; 722 } 723 if (--m->rm_refs >= 0) 724 goto on1; 725 } 726 b = -1 - tt->rn_b; 727 t = saved_tt->rn_p; 728 if (b > t->rn_b) 729 goto on1; /* Wasn't lifted at all */ 730 do { 731 x = t; 732 t = t->rn_p; 733 } while (b <= t->rn_b && x != top); 734 for (mp = &x->rn_mklist; (m = *mp) != NULL; mp = &m->rm_mklist) 735 if (m == saved_m) { 736 *mp = m->rm_mklist; 737 MKFree(m); 738 break; 739 } 740 if (m == 0) { 741 log(LOG_ERR, "rn_delete: couldn't find our annotation\n"); 742 if (tt->rn_flags & RNF_NORMAL) 743 return (0); /* Dangling ref to us */ 744 } 745 on1: 746 /* 747 * Eliminate us from tree 748 */ 749 if (tt->rn_flags & RNF_ROOT) 750 return (0); 751 #ifdef RN_DEBUG 752 /* Get us out of the creation list */ 753 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) 754 ; 755 if (t) t->rn_ybro = tt->rn_ybro; 756 #endif 757 t = tt->rn_p; 758 if ((dupedkey = saved_tt->rn_dupedkey) != 0) { 759 if (tt == saved_tt) { 760 x = dupedkey; 761 x->rn_p = t; 762 if (t->rn_l == tt) 763 t->rn_l = x; 764 else 765 t->rn_r = x; 766 } else { 767 for (x = p = saved_tt; p && p->rn_dupedkey != tt;) 768 p = p->rn_dupedkey; 769 if (p) 770 p->rn_dupedkey = tt->rn_dupedkey; 771 else 772 log(LOG_ERR, "rn_delete: couldn't find us\n"); 773 } 774 t = tt + 1; 775 if (t->rn_flags & RNF_ACTIVE) { 776 #ifndef RN_DEBUG 777 *++x = *t; 778 p = t->rn_p; 779 #else 780 b = t->rn_info; 781 *++x = *t; 782 t->rn_info = b; 783 p = t->rn_p; 784 #endif 785 if (p->rn_l == t) 786 p->rn_l = x; 787 else 788 p->rn_r = x; 789 x->rn_l->rn_p = x; 790 x->rn_r->rn_p = x; 791 } 792 goto out; 793 } 794 if (t->rn_l == tt) 795 x = t->rn_r; 796 else 797 x = t->rn_l; 798 p = t->rn_p; 799 if (p->rn_r == t) 800 p->rn_r = x; 801 else 802 p->rn_l = x; 803 x->rn_p = p; 804 /* 805 * Demote routes attached to us. 806 */ 807 if (t->rn_mklist) { 808 if (x->rn_b >= 0) { 809 for (mp = &x->rn_mklist; (m = *mp) != NULL;) 810 mp = &m->rm_mklist; 811 *mp = t->rn_mklist; 812 } else { 813 /* If there are any key,mask pairs in a sibling 814 duped-key chain, some subset will appear sorted 815 in the same order attached to our mklist */ 816 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey) 817 if (m == x->rn_mklist) { 818 struct radix_mask *mm = m->rm_mklist; 819 x->rn_mklist = 0; 820 if (--(m->rm_refs) < 0) 821 MKFree(m); 822 m = mm; 823 } 824 if (m) 825 log(LOG_ERR, "%s %p at %p\n", 826 "rn_delete: Orphaned Mask", m, x); 827 } 828 } 829 /* 830 * We may be holding an active internal node in the tree. 831 */ 832 x = tt + 1; 833 if (t != x) { 834 #ifndef RN_DEBUG 835 *t = *x; 836 #else 837 b = t->rn_info; 838 *t = *x; 839 t->rn_info = b; 840 #endif 841 t->rn_l->rn_p = t; 842 t->rn_r->rn_p = t; 843 p = x->rn_p; 844 if (p->rn_l == x) 845 p->rn_l = t; 846 else 847 p->rn_r = t; 848 } 849 out: 850 tt->rn_flags &= ~RNF_ACTIVE; 851 tt[1].rn_flags &= ~RNF_ACTIVE; 852 return (tt); 853 } 854 855 int 856 rn_walktree(h, f, w) 857 struct radix_node_head *h; 858 register int (*f)(struct radix_node *, void *); 859 void *w; 860 { 861 int error; 862 struct radix_node *base, *next; 863 register struct radix_node *rn = h->rnh_treetop; 864 /* 865 * This gets complicated because we may delete the node 866 * while applying the function f to it, so we need to calculate 867 * the successor node in advance. 868 */ 869 /* First time through node, go left */ 870 while (rn->rn_b >= 0) 871 rn = rn->rn_l; 872 for (;;) { 873 base = rn; 874 /* If at right child go back up, otherwise, go right */ 875 while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0) 876 rn = rn->rn_p; 877 /* Find the next *leaf* since next node might vanish, too */ 878 for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;) 879 rn = rn->rn_l; 880 next = rn; 881 /* Process leaves */ 882 while ((rn = base) != NULL) { 883 base = rn->rn_dupedkey; 884 if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w))) 885 return (error); 886 } 887 rn = next; 888 if (rn->rn_flags & RNF_ROOT) 889 return (0); 890 } 891 /* NOTREACHED */ 892 } 893 894 int 895 rn_inithead(head, off) 896 void **head; 897 int off; 898 { 899 register struct radix_node_head *rnh; 900 register struct radix_node *t, *tt, *ttt; 901 if (*head) 902 return (1); 903 R_Malloc(rnh, struct radix_node_head *, sizeof (*rnh)); 904 if (rnh == 0) 905 return (0); 906 Bzero(rnh, sizeof (*rnh)); 907 *head = rnh; 908 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes); 909 ttt = rnh->rnh_nodes + 2; 910 t->rn_r = ttt; 911 t->rn_p = t; 912 tt = t->rn_l; 913 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE; 914 tt->rn_b = -1 - off; 915 *ttt = *tt; 916 ttt->rn_key = rn_ones; 917 rnh->rnh_addaddr = rn_addroute; 918 rnh->rnh_deladdr = rn_delete; 919 rnh->rnh_matchaddr = rn_match; 920 rnh->rnh_lookup = rn_lookup; 921 rnh->rnh_walktree = rn_walktree; 922 rnh->rnh_treetop = t; 923 return (1); 924 } 925 926 void 927 rn_init() 928 { 929 char *cp, *cplim; 930 #ifdef _KERNEL 931 struct domain *dom; 932 933 for (dom = domains; dom; dom = dom->dom_next) 934 if (dom->dom_maxrtkey > max_keylen) 935 max_keylen = dom->dom_maxrtkey; 936 #endif 937 if (max_keylen == 0) { 938 log(LOG_ERR, 939 "rn_init: radix functions require max_keylen be set\n"); 940 return; 941 } 942 R_Malloc(rn_zeros, char *, 3 * max_keylen); 943 if (rn_zeros == NULL) 944 panic("rn_init"); 945 Bzero(rn_zeros, 3 * max_keylen); 946 rn_ones = cp = rn_zeros + max_keylen; 947 addmask_key = cplim = rn_ones + max_keylen; 948 while (cp < cplim) 949 *cp++ = -1; 950 if (rn_inithead((void **)&mask_rnhead, 0) == 0) 951 panic("rn_init 2"); 952 } 953