1 /* $OpenBSD: radix.c,v 1.11 2003/08/27 00:33:34 henric 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 = 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 return (m->rm_leaf); 292 } else { 293 off = min(t->rn_off, matched_off); 294 x = rn_search_m(v, t, m->rm_mask); 295 while (x && x->rn_mask != m->rm_mask) 296 x = x->rn_dupedkey; 297 if (x && rn_satsifies_leaf(v, x, off)) 298 return x; 299 } 300 } while ((m = m->rm_mklist) != NULL); 301 } 302 } while (t != top); 303 return 0; 304 } 305 306 #ifdef RN_DEBUG 307 int rn_nodenum; 308 struct radix_node *rn_clist; 309 int rn_saveinfo; 310 int rn_debug = 1; 311 #endif 312 313 struct radix_node * 314 rn_newpair(v, b, nodes) 315 void *v; 316 int b; 317 struct radix_node nodes[2]; 318 { 319 register struct radix_node *tt = nodes, *t = tt + 1; 320 t->rn_b = b; 321 t->rn_bmask = 0x80 >> (b & 7); 322 t->rn_l = tt; 323 t->rn_off = b >> 3; 324 tt->rn_b = -1; 325 tt->rn_key = (caddr_t)v; 326 tt->rn_p = t; 327 tt->rn_flags = t->rn_flags = RNF_ACTIVE; 328 #ifdef RN_DEBUG 329 tt->rn_info = rn_nodenum++; 330 t->rn_info = rn_nodenum++; 331 tt->rn_twin = t; 332 tt->rn_ybro = rn_clist; 333 rn_clist = tt; 334 #endif 335 return t; 336 } 337 338 struct radix_node * 339 rn_insert(v_arg, head, dupentry, nodes) 340 void *v_arg; 341 struct radix_node_head *head; 342 int *dupentry; 343 struct radix_node nodes[2]; 344 { 345 caddr_t v = v_arg; 346 struct radix_node *top = head->rnh_treetop; 347 int head_off = top->rn_off, vlen = (int)*((u_char *)v); 348 register struct radix_node *t = rn_search(v_arg, top); 349 register caddr_t cp = v + head_off; 350 register int b; 351 struct radix_node *tt; 352 /* 353 * Find first bit at which v and t->rn_key differ 354 */ 355 { 356 register caddr_t cp2 = t->rn_key + head_off; 357 register int cmp_res; 358 caddr_t cplim = v + vlen; 359 360 while (cp < cplim) 361 if (*cp2++ != *cp++) 362 goto on1; 363 *dupentry = 1; 364 return t; 365 on1: 366 *dupentry = 0; 367 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff; 368 for (b = (cp - v) << 3; cmp_res; b--) 369 cmp_res >>= 1; 370 } 371 { 372 register struct radix_node *p, *x = top; 373 cp = v; 374 do { 375 p = x; 376 if (cp[x->rn_off] & x->rn_bmask) 377 x = x->rn_r; 378 else 379 x = x->rn_l; 380 } while (b > (unsigned) x->rn_b); /* x->rn_b < b && x->rn_b >= 0 */ 381 #ifdef RN_DEBUG 382 if (rn_debug) 383 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p); 384 #endif 385 t = rn_newpair(v_arg, b, nodes); 386 tt = t->rn_l; 387 if ((cp[p->rn_off] & p->rn_bmask) == 0) 388 p->rn_l = t; 389 else 390 p->rn_r = t; 391 x->rn_p = t; 392 t->rn_p = p; /* frees x, p as temp vars below */ 393 if ((cp[t->rn_off] & t->rn_bmask) == 0) { 394 t->rn_r = x; 395 } else { 396 t->rn_r = tt; 397 t->rn_l = x; 398 } 399 #ifdef RN_DEBUG 400 if (rn_debug) 401 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p); 402 #endif 403 } 404 return (tt); 405 } 406 407 struct radix_node * 408 rn_addmask(n_arg, search, skip) 409 int search, skip; 410 void *n_arg; 411 { 412 caddr_t netmask = (caddr_t)n_arg; 413 register struct radix_node *x; 414 register caddr_t cp, cplim; 415 register int b = 0, mlen, j; 416 int maskduplicated, m0, isnormal; 417 struct radix_node *saved_x; 418 static int last_zeroed = 0; 419 420 if ((mlen = *(u_char *)netmask) > max_keylen) 421 mlen = max_keylen; 422 if (skip == 0) 423 skip = 1; 424 if (mlen <= skip) 425 return (mask_rnhead->rnh_nodes); 426 if (skip > 1) 427 Bcopy(rn_ones + 1, addmask_key + 1, skip - 1); 428 if ((m0 = mlen) > skip) 429 Bcopy(netmask + skip, addmask_key + skip, mlen - skip); 430 /* 431 * Trim trailing zeroes. 432 */ 433 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;) 434 cp--; 435 mlen = cp - addmask_key; 436 if (mlen <= skip) { 437 if (m0 >= last_zeroed) 438 last_zeroed = mlen; 439 return (mask_rnhead->rnh_nodes); 440 } 441 if (m0 < last_zeroed) 442 Bzero(addmask_key + m0, last_zeroed - m0); 443 *addmask_key = last_zeroed = mlen; 444 x = rn_search(addmask_key, rn_masktop); 445 if (Bcmp(addmask_key, x->rn_key, mlen) != 0) 446 x = 0; 447 if (x || search) 448 return (x); 449 R_Malloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x)); 450 if ((saved_x = x) == 0) 451 return (0); 452 Bzero(x, max_keylen + 2 * sizeof (*x)); 453 netmask = cp = (caddr_t)(x + 2); 454 Bcopy(addmask_key, cp, mlen); 455 x = rn_insert(cp, mask_rnhead, &maskduplicated, x); 456 if (maskduplicated) { 457 log(LOG_ERR, "rn_addmask: mask impossibly already in tree"); 458 Free(saved_x); 459 return (x); 460 } 461 /* 462 * Calculate index of mask, and check for normalcy. 463 */ 464 cplim = netmask + mlen; 465 isnormal = 1; 466 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;) 467 cp++; 468 if (cp != cplim) { 469 for (j = 0x80; (j & *cp) != 0; j >>= 1) 470 b++; 471 if (*cp != normal_chars[b] || cp != (cplim - 1)) 472 isnormal = 0; 473 } 474 b += (cp - netmask) << 3; 475 x->rn_b = -1 - b; 476 if (isnormal) 477 x->rn_flags |= RNF_NORMAL; 478 return (x); 479 } 480 481 static int /* XXX: arbitrary ordering for non-contiguous masks */ 482 rn_lexobetter(m_arg, n_arg) 483 void *m_arg, *n_arg; 484 { 485 register u_char *mp = m_arg, *np = n_arg, *lim; 486 487 if (*mp > *np) 488 return 1; /* not really, but need to check longer one first */ 489 if (*mp == *np) 490 for (lim = mp + *mp; mp < lim;) 491 if (*mp++ > *np++) 492 return 1; 493 return 0; 494 } 495 496 static struct radix_mask * 497 rn_new_radix_mask(tt, next) 498 register struct radix_node *tt; 499 register struct radix_mask *next; 500 { 501 register struct radix_mask *m; 502 503 MKGet(m); 504 if (m == 0) { 505 log(LOG_ERR, "Mask for route not entered\n"); 506 return (0); 507 } 508 Bzero(m, sizeof *m); 509 m->rm_b = tt->rn_b; 510 m->rm_flags = tt->rn_flags; 511 if (tt->rn_flags & RNF_NORMAL) 512 m->rm_leaf = tt; 513 else 514 m->rm_mask = tt->rn_mask; 515 m->rm_mklist = next; 516 tt->rn_mklist = m; 517 return m; 518 } 519 520 struct radix_node * 521 rn_addroute(v_arg, n_arg, head, treenodes) 522 void *v_arg, *n_arg; 523 struct radix_node_head *head; 524 struct radix_node treenodes[2]; 525 { 526 caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg; 527 register struct radix_node *t, *x = NULL, *tt; 528 struct radix_node *saved_tt, *top = head->rnh_treetop; 529 short b = 0, b_leaf = 0; 530 int keyduplicated; 531 caddr_t mmask; 532 struct radix_mask *m, **mp; 533 534 /* 535 * In dealing with non-contiguous masks, there may be 536 * many different routes which have the same mask. 537 * We will find it useful to have a unique pointer to 538 * the mask to speed avoiding duplicate references at 539 * nodes and possibly save time in calculating indices. 540 */ 541 if (netmask) { 542 if ((x = rn_addmask(netmask, 0, top->rn_off)) == 0) 543 return (0); 544 b_leaf = x->rn_b; 545 b = -1 - x->rn_b; 546 netmask = x->rn_key; 547 } 548 /* 549 * Deal with duplicated keys: attach node to previous instance 550 */ 551 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes); 552 if (keyduplicated) { 553 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) { 554 if (tt->rn_mask == netmask) 555 return (0); 556 if (netmask == 0 || 557 (tt->rn_mask && 558 ((b_leaf < tt->rn_b) || /* index(netmask) > node */ 559 rn_refines(netmask, tt->rn_mask) || 560 rn_lexobetter(netmask, tt->rn_mask)))) 561 break; 562 } 563 /* 564 * If the mask is not duplicated, we wouldn't 565 * find it among possible duplicate key entries 566 * anyway, so the above test doesn't hurt. 567 * 568 * We sort the masks for a duplicated key the same way as 569 * in a masklist -- most specific to least specific. 570 * This may require the unfortunate nuisance of relocating 571 * the head of the list. 572 */ 573 if (tt == saved_tt) { 574 struct radix_node *xx = x; 575 /* link in at head of list */ 576 (tt = treenodes)->rn_dupedkey = t; 577 tt->rn_flags = t->rn_flags; 578 tt->rn_p = x = t->rn_p; 579 if (x->rn_l == t) 580 x->rn_l = tt; 581 else 582 x->rn_r = tt; 583 saved_tt = tt; 584 x = xx; 585 } else { 586 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey; 587 t->rn_dupedkey = tt; 588 } 589 #ifdef RN_DEBUG 590 t=tt+1; 591 tt->rn_info = rn_nodenum++; 592 t->rn_info = rn_nodenum++; 593 tt->rn_twin = t; 594 tt->rn_ybro = rn_clist; 595 rn_clist = tt; 596 #endif 597 tt->rn_key = (caddr_t) v; 598 tt->rn_b = -1; 599 tt->rn_flags = RNF_ACTIVE; 600 } 601 /* 602 * Put mask in tree. 603 */ 604 if (netmask) { 605 tt->rn_mask = netmask; 606 tt->rn_b = x->rn_b; 607 tt->rn_flags |= x->rn_flags & RNF_NORMAL; 608 } 609 t = saved_tt->rn_p; 610 if (keyduplicated) 611 goto on2; 612 b_leaf = -1 - t->rn_b; 613 if (t->rn_r == saved_tt) 614 x = t->rn_l; 615 else 616 x = t->rn_r; 617 /* Promote general routes from below */ 618 if (x->rn_b < 0) { 619 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey) 620 if (x->rn_mask && (x->rn_b >= b_leaf) && x->rn_mklist == 0) { 621 *mp = m = rn_new_radix_mask(x, 0); 622 if (m) 623 mp = &m->rm_mklist; 624 } 625 } else if (x->rn_mklist) { 626 /* 627 * Skip over masks whose index is > that of new node 628 */ 629 for (mp = &x->rn_mklist; (m = *mp) != NULL; mp = &m->rm_mklist) 630 if (m->rm_b >= b_leaf) 631 break; 632 t->rn_mklist = m; 633 *mp = 0; 634 } 635 on2: 636 /* Add new route to highest possible ancestor's list */ 637 if ((netmask == 0) || (b > t->rn_b )) 638 return tt; /* can't lift at all */ 639 b_leaf = tt->rn_b; 640 do { 641 x = t; 642 t = t->rn_p; 643 } while (b <= t->rn_b && x != top); 644 /* 645 * Search through routes associated with node to 646 * insert new route according to index. 647 * Need same criteria as when sorting dupedkeys to avoid 648 * double loop on deletion. 649 */ 650 for (mp = &x->rn_mklist; (m = *mp) != NULL; mp = &m->rm_mklist) { 651 if (m->rm_b < b_leaf) 652 continue; 653 if (m->rm_b > b_leaf) 654 break; 655 if (m->rm_flags & RNF_NORMAL) { 656 mmask = m->rm_leaf->rn_mask; 657 if (tt->rn_flags & RNF_NORMAL) { 658 log(LOG_ERR, "Non-unique normal route, " 659 "mask not entered\n"); 660 return tt; 661 } 662 } else 663 mmask = m->rm_mask; 664 if (mmask == netmask) { 665 m->rm_refs++; 666 tt->rn_mklist = m; 667 return tt; 668 } 669 if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask)) 670 break; 671 } 672 *mp = rn_new_radix_mask(tt, *mp); 673 return tt; 674 } 675 676 struct radix_node * 677 rn_delete(v_arg, netmask_arg, head) 678 void *v_arg, *netmask_arg; 679 struct radix_node_head *head; 680 { 681 register struct radix_node *t, *p, *x, *tt; 682 struct radix_mask *m, *saved_m, **mp; 683 struct radix_node *dupedkey, *saved_tt, *top; 684 caddr_t v, netmask; 685 int b, head_off, vlen; 686 687 v = v_arg; 688 netmask = netmask_arg; 689 x = head->rnh_treetop; 690 tt = rn_search(v, x); 691 head_off = x->rn_off; 692 vlen = *(u_char *)v; 693 saved_tt = tt; 694 top = x; 695 if (tt == 0 || 696 Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off)) 697 return (0); 698 /* 699 * Delete our route from mask lists. 700 */ 701 if (netmask) { 702 if ((x = rn_addmask(netmask, 1, head_off)) == 0) 703 return (0); 704 netmask = x->rn_key; 705 while (tt->rn_mask != netmask) 706 if ((tt = tt->rn_dupedkey) == 0) 707 return (0); 708 } 709 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0) 710 goto on1; 711 if (tt->rn_flags & RNF_NORMAL) { 712 if (m->rm_leaf != tt || m->rm_refs > 0) { 713 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 714 return 0; /* dangling ref could cause disaster */ 715 } 716 } else { 717 if (m->rm_mask != tt->rn_mask) { 718 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 719 goto on1; 720 } 721 if (--m->rm_refs >= 0) 722 goto on1; 723 } 724 b = -1 - tt->rn_b; 725 t = saved_tt->rn_p; 726 if (b > t->rn_b) 727 goto on1; /* Wasn't lifted at all */ 728 do { 729 x = t; 730 t = t->rn_p; 731 } while (b <= t->rn_b && x != top); 732 for (mp = &x->rn_mklist; (m = *mp) != NULL; mp = &m->rm_mklist) 733 if (m == saved_m) { 734 *mp = m->rm_mklist; 735 MKFree(m); 736 break; 737 } 738 if (m == 0) { 739 log(LOG_ERR, "rn_delete: couldn't find our annotation\n"); 740 if (tt->rn_flags & RNF_NORMAL) 741 return (0); /* Dangling ref to us */ 742 } 743 on1: 744 /* 745 * Eliminate us from tree 746 */ 747 if (tt->rn_flags & RNF_ROOT) 748 return (0); 749 #ifdef RN_DEBUG 750 /* Get us out of the creation list */ 751 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) 752 ; 753 if (t) t->rn_ybro = tt->rn_ybro; 754 #endif 755 t = tt->rn_p; 756 if ((dupedkey = saved_tt->rn_dupedkey) != 0) { 757 if (tt == saved_tt) { 758 x = dupedkey; 759 x->rn_p = t; 760 if (t->rn_l == tt) 761 t->rn_l = x; 762 else 763 t->rn_r = x; 764 } else { 765 for (x = p = saved_tt; p && p->rn_dupedkey != tt;) 766 p = p->rn_dupedkey; 767 if (p) 768 p->rn_dupedkey = tt->rn_dupedkey; 769 else 770 log(LOG_ERR, "rn_delete: couldn't find us\n"); 771 } 772 t = tt + 1; 773 if (t->rn_flags & RNF_ACTIVE) { 774 #ifndef RN_DEBUG 775 *++x = *t; 776 p = t->rn_p; 777 #else 778 b = t->rn_info; 779 *++x = *t; 780 t->rn_info = b; 781 p = t->rn_p; 782 #endif 783 if (p->rn_l == t) 784 p->rn_l = x; 785 else 786 p->rn_r = x; 787 x->rn_l->rn_p = x; 788 x->rn_r->rn_p = x; 789 } 790 goto out; 791 } 792 if (t->rn_l == tt) 793 x = t->rn_r; 794 else 795 x = t->rn_l; 796 p = t->rn_p; 797 if (p->rn_r == t) 798 p->rn_r = x; 799 else 800 p->rn_l = x; 801 x->rn_p = p; 802 /* 803 * Demote routes attached to us. 804 */ 805 if (t->rn_mklist) { 806 if (x->rn_b >= 0) { 807 for (mp = &x->rn_mklist; (m = *mp) != NULL;) 808 mp = &m->rm_mklist; 809 *mp = t->rn_mklist; 810 } else { 811 /* If there are any key,mask pairs in a sibling 812 duped-key chain, some subset will appear sorted 813 in the same order attached to our mklist */ 814 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey) 815 if (m == x->rn_mklist) { 816 struct radix_mask *mm = m->rm_mklist; 817 x->rn_mklist = 0; 818 if (--(m->rm_refs) < 0) 819 MKFree(m); 820 m = mm; 821 } 822 if (m) 823 log(LOG_ERR, "%s %p at %p\n", 824 "rn_delete: Orphaned Mask", m, x); 825 } 826 } 827 /* 828 * We may be holding an active internal node in the tree. 829 */ 830 x = tt + 1; 831 if (t != x) { 832 #ifndef RN_DEBUG 833 *t = *x; 834 #else 835 b = t->rn_info; 836 *t = *x; 837 t->rn_info = b; 838 #endif 839 t->rn_l->rn_p = t; 840 t->rn_r->rn_p = t; 841 p = x->rn_p; 842 if (p->rn_l == x) 843 p->rn_l = t; 844 else 845 p->rn_r = t; 846 } 847 out: 848 tt->rn_flags &= ~RNF_ACTIVE; 849 tt[1].rn_flags &= ~RNF_ACTIVE; 850 return (tt); 851 } 852 853 int 854 rn_walktree(h, f, w) 855 struct radix_node_head *h; 856 register int (*f)(struct radix_node *, void *); 857 void *w; 858 { 859 int error; 860 struct radix_node *base, *next; 861 register struct radix_node *rn = h->rnh_treetop; 862 /* 863 * This gets complicated because we may delete the node 864 * while applying the function f to it, so we need to calculate 865 * the successor node in advance. 866 */ 867 /* First time through node, go left */ 868 while (rn->rn_b >= 0) 869 rn = rn->rn_l; 870 for (;;) { 871 base = rn; 872 /* If at right child go back up, otherwise, go right */ 873 while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0) 874 rn = rn->rn_p; 875 /* Find the next *leaf* since next node might vanish, too */ 876 for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;) 877 rn = rn->rn_l; 878 next = rn; 879 /* Process leaves */ 880 while ((rn = base) != NULL) { 881 base = rn->rn_dupedkey; 882 if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w))) 883 return (error); 884 } 885 rn = next; 886 if (rn->rn_flags & RNF_ROOT) 887 return (0); 888 } 889 /* NOTREACHED */ 890 } 891 892 int 893 rn_inithead(head, off) 894 void **head; 895 int off; 896 { 897 register struct radix_node_head *rnh; 898 register struct radix_node *t, *tt, *ttt; 899 if (*head) 900 return (1); 901 R_Malloc(rnh, struct radix_node_head *, sizeof (*rnh)); 902 if (rnh == 0) 903 return (0); 904 Bzero(rnh, sizeof (*rnh)); 905 *head = rnh; 906 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes); 907 ttt = rnh->rnh_nodes + 2; 908 t->rn_r = ttt; 909 t->rn_p = t; 910 tt = t->rn_l; 911 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE; 912 tt->rn_b = -1 - off; 913 *ttt = *tt; 914 ttt->rn_key = rn_ones; 915 rnh->rnh_addaddr = rn_addroute; 916 rnh->rnh_deladdr = rn_delete; 917 rnh->rnh_matchaddr = rn_match; 918 rnh->rnh_lookup = rn_lookup; 919 rnh->rnh_walktree = rn_walktree; 920 rnh->rnh_treetop = t; 921 return (1); 922 } 923 924 void 925 rn_init() 926 { 927 char *cp, *cplim; 928 #ifdef _KERNEL 929 struct domain *dom; 930 931 for (dom = domains; dom; dom = dom->dom_next) 932 if (dom->dom_maxrtkey > max_keylen) 933 max_keylen = dom->dom_maxrtkey; 934 #endif 935 if (max_keylen == 0) { 936 log(LOG_ERR, 937 "rn_init: radix functions require max_keylen be set\n"); 938 return; 939 } 940 R_Malloc(rn_zeros, char *, 3 * max_keylen); 941 if (rn_zeros == NULL) 942 panic("rn_init"); 943 Bzero(rn_zeros, 3 * max_keylen); 944 rn_ones = cp = rn_zeros + max_keylen; 945 addmask_key = cplim = rn_ones + max_keylen; 946 while (cp < cplim) 947 *cp++ = -1; 948 if (rn_inithead((void **)&mask_rnhead, 0) == 0) 949 panic("rn_init 2"); 950 } 951