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 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 */ 34 35 #ifndef lint 36 #if 0 37 static char sccsid[] = "@(#)radix.c 8.4 (Berkeley) 11/2/94"; 38 #endif 39 static const char rcsid[] = 40 "$Id$"; 41 #endif /* not lint */ 42 43 /* 44 * Routines to build and maintain radix trees for routing lookups. 45 */ 46 47 #include "defs.h" 48 49 #define log(x, msg) syslog(x, msg) 50 #define panic(s) {log(LOG_ERR,s); exit(1);} 51 #define min(a,b) (((a)<(b))?(a):(b)) 52 53 int max_keylen; 54 struct radix_mask *rn_mkfreelist; 55 struct radix_node_head *mask_rnhead; 56 static char *addmask_key; 57 static char normal_chars[] = {0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1}; 58 static char *rn_zeros, *rn_ones; 59 60 #define rn_masktop (mask_rnhead->rnh_treetop) 61 #undef Bcmp 62 #define Bcmp(a, b, l) (l == 0 ? 0 : bcmp((caddr_t)(a), (caddr_t)(b), (u_long)l)) 63 64 static int rn_satsifies_leaf(char *, struct radix_node *, int); 65 66 /* 67 * The data structure for the keys is a radix tree with one way 68 * branching removed. The index rn_b at an internal node n represents a bit 69 * position to be tested. The tree is arranged so that all descendants 70 * of a node n have keys whose bits all agree up to position rn_b - 1. 71 * (We say the index of n is rn_b.) 72 * 73 * There is at least one descendant which has a one bit at position rn_b, 74 * and at least one with a zero there. 75 * 76 * A route is determined by a pair of key and mask. We require that the 77 * bit-wise logical and of the key and mask to be the key. 78 * We define the index of a route to associated with the mask to be 79 * the first bit number in the mask where 0 occurs (with bit number 0 80 * representing the highest order bit). 81 * 82 * We say a mask is normal if every bit is 0, past the index of the mask. 83 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_b, 84 * and m is a normal mask, then the route applies to every descendant of n. 85 * If the index(m) < rn_b, this implies the trailing last few bits of k 86 * before bit b are all 0, (and hence consequently true of every descendant 87 * of n), so the route applies to all descendants of the node as well. 88 * 89 * Similar logic shows that a non-normal mask m such that 90 * index(m) <= index(n) could potentially apply to many children of n. 91 * Thus, for each non-host route, we attach its mask to a list at an internal 92 * node as high in the tree as we can go. 93 * 94 * The present version of the code makes use of normal routes in short- 95 * circuiting an explict mask and compare operation when testing whether 96 * a key satisfies a normal route, and also in remembering the unique leaf 97 * that governs a subtree. 98 */ 99 100 struct radix_node * 101 rn_search(void *v_arg, 102 struct radix_node *head) 103 { 104 register struct radix_node *x; 105 register caddr_t v; 106 107 for (x = head, v = v_arg; x->rn_b >= 0;) { 108 if (x->rn_bmask & v[x->rn_off]) 109 x = x->rn_r; 110 else 111 x = x->rn_l; 112 } 113 return (x); 114 } 115 116 struct radix_node * 117 rn_search_m(void *v_arg, 118 struct radix_node *head, 119 void *m_arg) 120 { 121 register struct radix_node *x; 122 register caddr_t v = v_arg, m = m_arg; 123 124 for (x = head; x->rn_b >= 0;) { 125 if ((x->rn_bmask & m[x->rn_off]) && 126 (x->rn_bmask & v[x->rn_off])) 127 x = x->rn_r; 128 else 129 x = x->rn_l; 130 } 131 return x; 132 } 133 134 int 135 rn_refines(void* m_arg, void *n_arg) 136 { 137 register caddr_t m = m_arg, n = n_arg; 138 register caddr_t lim, lim2 = lim = n + *(u_char *)n; 139 int longer = (*(u_char *)n++) - (int)(*(u_char *)m++); 140 int masks_are_equal = 1; 141 142 if (longer > 0) 143 lim -= longer; 144 while (n < lim) { 145 if (*n & ~(*m)) 146 return 0; 147 if (*n++ != *m++) 148 masks_are_equal = 0; 149 } 150 while (n < lim2) 151 if (*n++) 152 return 0; 153 if (masks_are_equal && (longer < 0)) 154 for (lim2 = m - longer; m < lim2; ) 155 if (*m++) 156 return 1; 157 return (!masks_are_equal); 158 } 159 160 struct radix_node * 161 rn_lookup(v_arg, m_arg, head) 162 void *v_arg, *m_arg; 163 struct radix_node_head *head; 164 { 165 register 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_satsifies_leaf(char *trial, 183 register struct radix_node *leaf, 184 int skip) 185 { 186 register 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 register struct radix_node *t = head->rnh_treetop, *x; 207 register 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 register 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_satsifies_leaf(v, t, matched_off)) 285 return t; 286 t = saved_t; 287 /* start searching up the tree */ 288 do { 289 register struct radix_mask *m; 290 t = t->rn_p; 291 if ((m = t->rn_mklist)) { 292 /* 293 * If non-contiguous masks ever become important 294 * we can restore the masking and open coding of 295 * the search and satisfaction test and put the 296 * calculation of "off" back before the "do". 297 */ 298 do { 299 if (m->rm_flags & RNF_NORMAL) { 300 if (rn_b <= m->rm_b) 301 return (m->rm_leaf); 302 } else { 303 off = min(t->rn_off, matched_off); 304 x = rn_search_m(v, t, m->rm_mask); 305 while (x && x->rn_mask != m->rm_mask) 306 x = x->rn_dupedkey; 307 if (x && rn_satsifies_leaf(v, x, off)) 308 return x; 309 } 310 } while ((m = m->rm_mklist)); 311 } 312 } while (t != top); 313 return 0; 314 } 315 316 #ifdef RN_DEBUG 317 int rn_nodenum; 318 struct radix_node *rn_clist; 319 int rn_saveinfo; 320 int rn_debug = 1; 321 #endif 322 323 struct radix_node * 324 rn_newpair(void *v, int b, struct radix_node nodes[2]) 325 { 326 register struct radix_node *tt = nodes, *t = tt + 1; 327 t->rn_b = b; t->rn_bmask = 0x80 >> (b & 7); 328 t->rn_l = tt; t->rn_off = b >> 3; 329 tt->rn_b = -1; tt->rn_key = (caddr_t)v; tt->rn_p = t; 330 tt->rn_flags = t->rn_flags = RNF_ACTIVE; 331 #ifdef RN_DEBUG 332 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 333 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 334 #endif 335 return t; 336 } 337 338 struct radix_node * 339 rn_insert(void* v_arg, 340 struct radix_node_head *head, 341 int *dupentry, 342 struct radix_node nodes[2]) 343 { 344 caddr_t v = v_arg; 345 struct radix_node *top = head->rnh_treetop; 346 int head_off = top->rn_off, vlen = (int)*((u_char *)v); 347 register struct radix_node *t = rn_search(v_arg, top); 348 register caddr_t cp = v + head_off; 349 register int b; 350 struct radix_node *tt; 351 352 /* 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 /* handle adding 255.255.255.255 */ 364 if (!(t->rn_flags & RNF_ROOT) || *(cp2-1) == 0) { 365 *dupentry = 1; 366 return t; 367 } 368 on1: 369 *dupentry = 0; 370 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff; 371 for (b = (cp - v) << 3; cmp_res; b--) 372 cmp_res >>= 1; 373 } 374 { 375 register struct radix_node *p, *x = top; 376 cp = v; 377 do { 378 p = x; 379 if (cp[x->rn_off] & x->rn_bmask) 380 x = x->rn_r; 381 else 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); tt = t->rn_l; 388 if ((cp[p->rn_off] & p->rn_bmask) == 0) 389 p->rn_l = t; 390 else 391 p->rn_r = t; 392 x->rn_p = t; 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; t->rn_l = x; 397 } 398 #ifdef RN_DEBUG 399 if (rn_debug) 400 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p); 401 #endif 402 } 403 return (tt); 404 } 405 406 struct radix_node * 407 rn_addmask(void *n_arg, int search, int skip) 408 { 409 caddr_t netmask = (caddr_t)n_arg; 410 register struct radix_node *x; 411 register caddr_t cp, cplim; 412 register int b = 0, mlen, j; 413 int maskduplicated, m0, isnormal; 414 struct radix_node *saved_x; 415 static int last_zeroed = 0; 416 417 if ((mlen = *(u_char *)netmask) > max_keylen) 418 mlen = max_keylen; 419 if (skip == 0) 420 skip = 1; 421 if (mlen <= skip) 422 return (mask_rnhead->rnh_nodes); 423 if (skip > 1) 424 Bcopy(rn_ones + 1, addmask_key + 1, skip - 1); 425 if ((m0 = mlen) > skip) 426 Bcopy(netmask + skip, addmask_key + skip, mlen - skip); 427 /* 428 * Trim trailing zeroes. 429 */ 430 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;) 431 cp--; 432 mlen = cp - addmask_key; 433 if (mlen <= skip) { 434 if (m0 >= last_zeroed) 435 last_zeroed = mlen; 436 return (mask_rnhead->rnh_nodes); 437 } 438 if (m0 < last_zeroed) 439 Bzero(addmask_key + m0, last_zeroed - m0); 440 *addmask_key = last_zeroed = mlen; 441 x = rn_search(addmask_key, rn_masktop); 442 if (Bcmp(addmask_key, x->rn_key, mlen) != 0) 443 x = 0; 444 if (x || search) 445 return (x); 446 x = (struct radix_node *) 447 rtmalloc(max_keylen + 2 * sizeof (*x), "rn_addmask"); 448 if ((saved_x = x) == 0) 449 return (0); 450 Bzero(x, max_keylen + 2 * sizeof (*x)); 451 netmask = cp = (caddr_t)(x + 2); 452 Bcopy(addmask_key, cp, mlen); 453 x = rn_insert(cp, mask_rnhead, &maskduplicated, x); 454 if (maskduplicated) { 455 log(LOG_ERR, "rn_addmask: mask impossibly already in tree"); 456 Free(saved_x); 457 return (x); 458 } 459 /* 460 * Calculate index of mask, and check for normalcy. 461 */ 462 cplim = netmask + mlen; isnormal = 1; 463 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;) 464 cp++; 465 if (cp != cplim) { 466 for (j = 0x80; (j & *cp) != 0; j >>= 1) 467 b++; 468 if (*cp != normal_chars[b] || cp != (cplim - 1)) 469 isnormal = 0; 470 } 471 b += (cp - netmask) << 3; 472 x->rn_b = -1 - b; 473 if (isnormal) 474 x->rn_flags |= RNF_NORMAL; 475 return (x); 476 } 477 478 static int /* XXX: arbitrary ordering for non-contiguous masks */ 479 rn_lexobetter(void *m_arg, void *n_arg) 480 { 481 register u_char *mp = m_arg, *np = n_arg, *lim; 482 483 if (*mp > *np) 484 return 1; /* not really, but need to check longer one first */ 485 if (*mp == *np) 486 for (lim = mp + *mp; mp < lim;) 487 if (*mp++ > *np++) 488 return 1; 489 return 0; 490 } 491 492 static struct radix_mask * 493 rn_new_radix_mask(register struct radix_node *tt, 494 register struct radix_mask *next) 495 { 496 register struct radix_mask *m; 497 498 MKGet(m); 499 if (m == 0) { 500 log(LOG_ERR, "Mask for route not entered\n"); 501 return (0); 502 } 503 Bzero(m, sizeof *m); 504 m->rm_b = tt->rn_b; 505 m->rm_flags = tt->rn_flags; 506 if (tt->rn_flags & RNF_NORMAL) 507 m->rm_leaf = tt; 508 else 509 m->rm_mask = tt->rn_mask; 510 m->rm_mklist = next; 511 tt->rn_mklist = m; 512 return m; 513 } 514 515 struct radix_node * 516 rn_addroute(void *v_arg, 517 void *n_arg, 518 struct radix_node_head *head, 519 struct radix_node treenodes[2]) 520 { 521 caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg; 522 register struct radix_node *t, *x = 0, *tt; 523 struct radix_node *saved_tt, *top = head->rnh_treetop; 524 short b = 0, b_leaf = 0; 525 int keyduplicated; 526 caddr_t mmask; 527 struct radix_mask *m, **mp; 528 529 /* 530 * In dealing with non-contiguous masks, there may be 531 * many different routes which have the same mask. 532 * We will find it useful to have a unique pointer to 533 * the mask to speed avoiding duplicate references at 534 * nodes and possibly save time in calculating indices. 535 */ 536 if (netmask) { 537 if ((x = rn_addmask(netmask, 0, top->rn_off)) == 0) 538 return (0); 539 b_leaf = x->rn_b; 540 b = -1 - x->rn_b; 541 netmask = x->rn_key; 542 } 543 /* 544 * Deal with duplicated keys: attach node to previous instance 545 */ 546 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes); 547 if (keyduplicated) { 548 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) { 549 if (tt->rn_mask == netmask) 550 return (0); 551 if (netmask == 0 || 552 (tt->rn_mask && 553 ((b_leaf < tt->rn_b) || /* index(netmask) > node */ 554 rn_refines(netmask, tt->rn_mask) || 555 rn_lexobetter(netmask, tt->rn_mask)))) 556 break; 557 } 558 /* 559 * If the mask is not duplicated, we wouldn't 560 * find it among possible duplicate key entries 561 * anyway, so the above test doesn't hurt. 562 * 563 * We sort the masks for a duplicated key the same way as 564 * in a masklist -- most specific to least specific. 565 * This may require the unfortunate nuisance of relocating 566 * the head of the list. 567 */ 568 if (tt == saved_tt) { 569 struct radix_node *xx = x; 570 /* link in at head of list */ 571 (tt = treenodes)->rn_dupedkey = t; 572 tt->rn_flags = t->rn_flags; 573 tt->rn_p = x = t->rn_p; 574 if (x->rn_l == t) x->rn_l = tt; else x->rn_r = tt; 575 saved_tt = tt; x = xx; 576 } else { 577 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey; 578 t->rn_dupedkey = tt; 579 } 580 #ifdef RN_DEBUG 581 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 582 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 583 #endif 584 tt->rn_key = (caddr_t) v; 585 tt->rn_b = -1; 586 tt->rn_flags = RNF_ACTIVE; 587 } 588 /* 589 * Put mask in tree. 590 */ 591 if (netmask) { 592 tt->rn_mask = netmask; 593 tt->rn_b = x->rn_b; 594 tt->rn_flags |= x->rn_flags & RNF_NORMAL; 595 } 596 t = saved_tt->rn_p; 597 if (keyduplicated) 598 goto on2; 599 b_leaf = -1 - t->rn_b; 600 if (t->rn_r == saved_tt) x = t->rn_l; else x = t->rn_r; 601 /* Promote general routes from below */ 602 if (x->rn_b < 0) { 603 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey) 604 if (x->rn_mask && (x->rn_b >= b_leaf) && x->rn_mklist == 0) { 605 if ((*mp = m = rn_new_radix_mask(x, 0))) 606 mp = &m->rm_mklist; 607 } 608 } else if (x->rn_mklist) { 609 /* 610 * Skip over masks whose index is > that of new node 611 */ 612 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 613 if (m->rm_b >= b_leaf) 614 break; 615 t->rn_mklist = m; *mp = 0; 616 } 617 on2: 618 /* Add new route to highest possible ancestor's list */ 619 if ((netmask == 0) || (b > t->rn_b )) 620 return tt; /* can't lift at all */ 621 b_leaf = tt->rn_b; 622 do { 623 x = t; 624 t = t->rn_p; 625 } while (b <= t->rn_b && x != top); 626 /* 627 * Search through routes associated with node to 628 * insert new route according to index. 629 * Need same criteria as when sorting dupedkeys to avoid 630 * double loop on deletion. 631 */ 632 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) { 633 if (m->rm_b < b_leaf) 634 continue; 635 if (m->rm_b > b_leaf) 636 break; 637 if (m->rm_flags & RNF_NORMAL) { 638 mmask = m->rm_leaf->rn_mask; 639 if (tt->rn_flags & RNF_NORMAL) { 640 log(LOG_ERR, 641 "Non-unique normal route, mask not entered"); 642 return tt; 643 } 644 } else 645 mmask = m->rm_mask; 646 if (mmask == netmask) { 647 m->rm_refs++; 648 tt->rn_mklist = m; 649 return tt; 650 } 651 if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask)) 652 break; 653 } 654 *mp = rn_new_radix_mask(tt, *mp); 655 return tt; 656 } 657 658 struct radix_node * 659 rn_delete(void *v_arg, 660 void *netmask_arg, 661 struct radix_node_head *head) 662 { 663 register struct radix_node *t, *p, *x, *tt; 664 struct radix_mask *m, *saved_m, **mp; 665 struct radix_node *dupedkey, *saved_tt, *top; 666 caddr_t v, netmask; 667 int b, head_off, vlen; 668 669 v = v_arg; 670 netmask = netmask_arg; 671 x = head->rnh_treetop; 672 tt = rn_search(v, x); 673 head_off = x->rn_off; 674 vlen = *(u_char *)v; 675 saved_tt = tt; 676 top = x; 677 if (tt == 0 || 678 Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off)) 679 return (0); 680 /* 681 * Delete our route from mask lists. 682 */ 683 if (netmask) { 684 if ((x = rn_addmask(netmask, 1, head_off)) == 0) 685 return (0); 686 netmask = x->rn_key; 687 while (tt->rn_mask != netmask) 688 if ((tt = tt->rn_dupedkey) == 0) 689 return (0); 690 } 691 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0) 692 goto on1; 693 if (tt->rn_flags & RNF_NORMAL) { 694 if (m->rm_leaf != tt || m->rm_refs > 0) { 695 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 696 return 0; /* dangling ref could cause disaster */ 697 } 698 } else { 699 if (m->rm_mask != tt->rn_mask) { 700 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 701 goto on1; 702 } 703 if (--m->rm_refs >= 0) 704 goto on1; 705 } 706 b = -1 - tt->rn_b; 707 t = saved_tt->rn_p; 708 if (b > t->rn_b) 709 goto on1; /* Wasn't lifted at all */ 710 do { 711 x = t; 712 t = t->rn_p; 713 } while (b <= t->rn_b && x != top); 714 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 715 if (m == saved_m) { 716 *mp = m->rm_mklist; 717 MKFree(m); 718 break; 719 } 720 if (m == 0) { 721 log(LOG_ERR, "rn_delete: couldn't find our annotation\n"); 722 if (tt->rn_flags & RNF_NORMAL) 723 return (0); /* Dangling ref to us */ 724 } 725 on1: 726 /* 727 * Eliminate us from tree 728 */ 729 if (tt->rn_flags & RNF_ROOT) 730 return (0); 731 #ifdef RN_DEBUG 732 /* Get us out of the creation list */ 733 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {} 734 if (t) t->rn_ybro = tt->rn_ybro; 735 #endif 736 t = tt->rn_p; 737 if ((dupedkey = saved_tt->rn_dupedkey)) { 738 if (tt == saved_tt) { 739 x = dupedkey; x->rn_p = t; 740 if (t->rn_l == tt) t->rn_l = x; else t->rn_r = x; 741 } else { 742 for (x = p = saved_tt; p && p->rn_dupedkey != tt;) 743 p = p->rn_dupedkey; 744 if (p) p->rn_dupedkey = tt->rn_dupedkey; 745 else log(LOG_ERR, "rn_delete: couldn't find us\n"); 746 } 747 t = tt + 1; 748 if (t->rn_flags & RNF_ACTIVE) { 749 #ifndef RN_DEBUG 750 *++x = *t; p = t->rn_p; 751 #else 752 b = t->rn_info; *++x = *t; t->rn_info = b; p = t->rn_p; 753 #endif 754 if (p->rn_l == t) p->rn_l = x; else p->rn_r = x; 755 x->rn_l->rn_p = x; x->rn_r->rn_p = x; 756 } 757 goto out; 758 } 759 if (t->rn_l == tt) x = t->rn_r; else x = t->rn_l; 760 p = t->rn_p; 761 if (p->rn_r == t) p->rn_r = x; else p->rn_l = x; 762 x->rn_p = p; 763 /* 764 * Demote routes attached to us. 765 */ 766 if (t->rn_mklist) { 767 if (x->rn_b >= 0) { 768 for (mp = &x->rn_mklist; (m = *mp);) 769 mp = &m->rm_mklist; 770 *mp = t->rn_mklist; 771 } else { 772 /* If there are any key,mask pairs in a sibling 773 duped-key chain, some subset will appear sorted 774 in the same order attached to our mklist */ 775 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey) 776 if (m == x->rn_mklist) { 777 struct radix_mask *mm = m->rm_mklist; 778 x->rn_mklist = 0; 779 if (--(m->rm_refs) < 0) 780 MKFree(m); 781 m = mm; 782 } 783 if (m) 784 syslog(LOG_ERR, "%s %lx at %lx\n", 785 "rn_delete: Orphaned Mask", 786 (unsigned long)m, 787 (unsigned long)x); 788 } 789 } 790 /* 791 * We may be holding an active internal node in the tree. 792 */ 793 x = tt + 1; 794 if (t != x) { 795 #ifndef RN_DEBUG 796 *t = *x; 797 #else 798 b = t->rn_info; *t = *x; t->rn_info = b; 799 #endif 800 t->rn_l->rn_p = t; t->rn_r->rn_p = t; 801 p = x->rn_p; 802 if (p->rn_l == x) p->rn_l = t; else p->rn_r = t; 803 } 804 out: 805 tt->rn_flags &= ~RNF_ACTIVE; 806 tt[1].rn_flags &= ~RNF_ACTIVE; 807 return (tt); 808 } 809 810 int 811 rn_walktree(struct radix_node_head *h, 812 register int (*f)(struct radix_node *, struct walkarg*), 813 struct walkarg *w) 814 { 815 int error; 816 struct radix_node *base, *next; 817 register struct radix_node *rn = h->rnh_treetop; 818 /* 819 * This gets complicated because we may delete the node 820 * while applying the function f to it, so we need to calculate 821 * the successor node in advance. 822 */ 823 /* First time through node, go left */ 824 while (rn->rn_b >= 0) 825 rn = rn->rn_l; 826 for (;;) { 827 base = rn; 828 /* If at right child go back up, otherwise, go right */ 829 while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0) 830 rn = rn->rn_p; 831 /* Find the next *leaf* since next node might vanish, too */ 832 for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;) 833 rn = rn->rn_l; 834 next = rn; 835 /* Process leaves */ 836 while ((rn = base)) { 837 base = rn->rn_dupedkey; 838 if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w))) 839 return (error); 840 } 841 rn = next; 842 if (rn->rn_flags & RNF_ROOT) 843 return (0); 844 } 845 /* NOTREACHED */ 846 } 847 848 int 849 rn_inithead(void **head, int off) 850 { 851 register struct radix_node_head *rnh; 852 register struct radix_node *t, *tt, *ttt; 853 if (*head) 854 return (1); 855 rnh = (struct radix_node_head *)rtmalloc(sizeof (*rnh), "rn_inithead"); 856 if (rnh == 0) 857 return (0); 858 Bzero(rnh, sizeof (*rnh)); 859 *head = rnh; 860 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes); 861 ttt = rnh->rnh_nodes + 2; 862 t->rn_r = ttt; 863 t->rn_p = t; 864 tt = t->rn_l; 865 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE; 866 tt->rn_b = -1 - off; 867 *ttt = *tt; 868 ttt->rn_key = rn_ones; 869 rnh->rnh_addaddr = rn_addroute; 870 rnh->rnh_deladdr = rn_delete; 871 rnh->rnh_matchaddr = rn_match; 872 rnh->rnh_lookup = rn_lookup; 873 rnh->rnh_walktree = rn_walktree; 874 rnh->rnh_treetop = t; 875 return (1); 876 } 877 878 void 879 rn_init(void) 880 { 881 char *cp, *cplim; 882 if (max_keylen == 0) { 883 printf("rn_init: radix functions require max_keylen be set\n"); 884 return; 885 } 886 rn_zeros = (char *)rtmalloc(3 * max_keylen, "rn_init"); 887 if (rn_zeros == NULL) 888 panic("rn_init"); 889 Bzero(rn_zeros, 3 * max_keylen); 890 rn_ones = cp = rn_zeros + max_keylen; 891 addmask_key = cplim = rn_ones + max_keylen; 892 while (cp < cplim) 893 *cp++ = -1; 894 if (rn_inithead((void **)&mask_rnhead, 0) == 0) 895 panic("rn_init 2"); 896 } 897 898