1 /* $OpenBSD: radix.c,v 1.7 2001/07/21 14:34:47 itojun 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. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)radix.c 8.4 (Berkeley) 11/2/94 37 */ 38 39 /* 40 * Routines to build and maintain radix trees for routing lookups. 41 */ 42 #include <sys/param.h> 43 #ifdef _KERNEL 44 #include <sys/systm.h> 45 #include <sys/malloc.h> 46 #define M_DONTWAIT M_NOWAIT 47 #include <sys/domain.h> 48 #else 49 #include <stdlib.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #endif 53 #include <sys/syslog.h> 54 #include <net/radix.h> 55 56 int max_keylen; 57 struct radix_mask *rn_mkfreelist; 58 struct radix_node_head *mask_rnhead; 59 static char *addmask_key; 60 static char normal_chars[] = {0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1}; 61 static char *rn_zeros, *rn_ones; 62 63 #define rn_masktop (mask_rnhead->rnh_treetop) 64 #undef Bcmp 65 #define Bcmp(a, b, l) (l == 0 ? 0 : bcmp((caddr_t)(a), (caddr_t)(b), (u_long)l)) 66 67 68 static int rn_satsifies_leaf __P((char *, struct radix_node *, int)); 69 static int rn_lexobetter __P((void *, void *)); 70 static struct radix_mask *rn_new_radix_mask __P((struct radix_node *, 71 struct radix_mask *)); 72 /* 73 * The data structure for the keys is a radix tree with one way 74 * branching removed. The index rn_b at an internal node n represents a bit 75 * position to be tested. The tree is arranged so that all descendants 76 * of a node n have keys whose bits all agree up to position rn_b - 1. 77 * (We say the index of n is rn_b.) 78 * 79 * There is at least one descendant which has a one bit at position rn_b, 80 * and at least one with a zero there. 81 * 82 * A route is determined by a pair of key and mask. We require that the 83 * bit-wise logical and of the key and mask to be the key. 84 * We define the index of a route to associated with the mask to be 85 * the first bit number in the mask where 0 occurs (with bit number 0 86 * representing the highest order bit). 87 * 88 * We say a mask is normal if every bit is 0, past the index of the mask. 89 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_b, 90 * and m is a normal mask, then the route applies to every descendant of n. 91 * If the index(m) < rn_b, this implies the trailing last few bits of k 92 * before bit b are all 0, (and hence consequently true of every descendant 93 * of n), so the route applies to all descendants of the node as well. 94 * 95 * Similar logic shows that a non-normal mask m such that 96 * index(m) <= index(n) could potentially apply to many children of n. 97 * Thus, for each non-host route, we attach its mask to a list at an internal 98 * node as high in the tree as we can go. 99 * 100 * The present version of the code makes use of normal routes in short- 101 * circuiting an explict mask and compare operation when testing whether 102 * a key satisfies a normal route, and also in remembering the unique leaf 103 * that governs a subtree. 104 */ 105 106 struct radix_node * 107 rn_search(v_arg, head) 108 void *v_arg; 109 struct radix_node *head; 110 { 111 register struct radix_node *x; 112 register caddr_t v; 113 114 for (x = head, v = v_arg; x->rn_b >= 0;) { 115 if (x->rn_bmask & v[x->rn_off]) 116 x = x->rn_r; 117 else 118 x = x->rn_l; 119 } 120 return (x); 121 } 122 123 struct radix_node * 124 rn_search_m(v_arg, head, m_arg) 125 struct radix_node *head; 126 void *v_arg, *m_arg; 127 { 128 register struct radix_node *x; 129 register caddr_t v = v_arg, m = m_arg; 130 131 for (x = head; x->rn_b >= 0;) { 132 if ((x->rn_bmask & m[x->rn_off]) && 133 (x->rn_bmask & v[x->rn_off])) 134 x = x->rn_r; 135 else 136 x = x->rn_l; 137 } 138 return x; 139 } 140 141 int 142 rn_refines(m_arg, n_arg) 143 void *m_arg, *n_arg; 144 { 145 register caddr_t m = m_arg, n = n_arg; 146 register caddr_t lim, lim2 = lim = n + *(u_char *)n; 147 int longer = (*(u_char *)n++) - (int)(*(u_char *)m++); 148 int masks_are_equal = 1; 149 150 if (longer > 0) 151 lim -= longer; 152 while (n < lim) { 153 if (*n & ~(*m)) 154 return 0; 155 if (*n++ != *m++) 156 masks_are_equal = 0; 157 } 158 while (n < lim2) 159 if (*n++) 160 return 0; 161 if (masks_are_equal && (longer < 0)) 162 for (lim2 = m - longer; m < lim2; ) 163 if (*m++) 164 return 1; 165 return (!masks_are_equal); 166 } 167 168 struct radix_node * 169 rn_lookup(v_arg, m_arg, head) 170 void *v_arg, *m_arg; 171 struct radix_node_head *head; 172 { 173 register struct radix_node *x; 174 caddr_t netmask = 0; 175 176 if (m_arg) { 177 if ((x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_off)) == 0) 178 return (0); 179 netmask = x->rn_key; 180 } 181 x = rn_match(v_arg, head); 182 if (x && netmask) { 183 while (x && x->rn_mask != netmask) 184 x = x->rn_dupedkey; 185 } 186 return x; 187 } 188 189 static int 190 rn_satsifies_leaf(trial, leaf, skip) 191 char *trial; 192 register struct radix_node *leaf; 193 int skip; 194 { 195 register char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask; 196 char *cplim; 197 int length = min(*(u_char *)cp, *(u_char *)cp2); 198 199 if (cp3 == 0) 200 cp3 = rn_ones; 201 else 202 length = min(length, *(u_char *)cp3); 203 cplim = cp + length; cp3 += skip; cp2 += skip; 204 for (cp += skip; cp < cplim; cp++, cp2++, cp3++) 205 if ((*cp ^ *cp2) & *cp3) 206 return 0; 207 return 1; 208 } 209 210 struct radix_node * 211 rn_match(v_arg, head) 212 void *v_arg; 213 struct radix_node_head *head; 214 { 215 caddr_t v = v_arg; 216 register struct radix_node *t = head->rnh_treetop, *x; 217 register caddr_t cp = v, cp2; 218 caddr_t cplim; 219 struct radix_node *saved_t, *top = t; 220 int off = t->rn_off, vlen = *(u_char *)cp, matched_off; 221 register int test, b, rn_b; 222 223 /* 224 * Open code rn_search(v, top) to avoid overhead of extra 225 * subroutine call. 226 */ 227 for (; t->rn_b >= 0; ) { 228 if (t->rn_bmask & cp[t->rn_off]) 229 t = t->rn_r; 230 else 231 t = t->rn_l; 232 } 233 /* 234 * See if we match exactly as a host destination 235 * or at least learn how many bits match, for normal mask finesse. 236 * 237 * It doesn't hurt us to limit how many bytes to check 238 * to the length of the mask, since if it matches we had a genuine 239 * match and the leaf we have is the most specific one anyway; 240 * if it didn't match with a shorter length it would fail 241 * with a long one. This wins big for class B&C netmasks which 242 * are probably the most common case... 243 */ 244 if (t->rn_mask) 245 vlen = *(u_char *)t->rn_mask; 246 cp += off; cp2 = t->rn_key + off; cplim = v + vlen; 247 for (; cp < cplim; cp++, cp2++) 248 if (*cp != *cp2) 249 goto on1; 250 /* 251 * This extra grot is in case we are explicitly asked 252 * to look up the default. Ugh! 253 */ 254 if ((t->rn_flags & RNF_ROOT) && t->rn_dupedkey) 255 t = t->rn_dupedkey; 256 return t; 257 on1: 258 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */ 259 for (b = 7; (test >>= 1) > 0;) 260 b--; 261 matched_off = cp - v; 262 b += matched_off << 3; 263 rn_b = -1 - b; 264 /* 265 * If there is a host route in a duped-key chain, it will be first. 266 */ 267 if ((saved_t = t)->rn_mask == 0) 268 t = t->rn_dupedkey; 269 for (; t && !(t->rn_flags & RNF_IGNORE); t = t->rn_dupedkey) 270 /* 271 * Even if we don't match exactly as a host, 272 * we may match if the leaf we wound up at is 273 * a route to a net. 274 */ 275 if (t->rn_flags & RNF_NORMAL) { 276 if (rn_b <= t->rn_b) 277 return t; 278 } else if (rn_satsifies_leaf(v, t, matched_off)) 279 return t; 280 t = saved_t; 281 /* start searching up the tree */ 282 do { 283 register struct radix_mask *m; 284 t = t->rn_p; 285 if ((m = t->rn_mklist) != NULL) { 286 /* 287 * If non-contiguous masks ever become important 288 * we can restore the masking and open coding of 289 * the search and satisfaction test and put the 290 * calculation of "off" back before the "do". 291 */ 292 do { 293 if (m->rm_flags & RNF_NORMAL) { 294 if (rn_b <= m->rm_b && 295 !(m->rm_flags & RNF_IGNORE)) 296 return (m->rm_leaf); 297 } else { 298 off = min(t->rn_off, matched_off); 299 x = rn_search_m(v, t, m->rm_mask); 300 while (x && x->rn_mask != m->rm_mask) 301 x = x->rn_dupedkey; 302 if (x && !(x->rn_flags & RNF_IGNORE) && 303 rn_satsifies_leaf(v, x, off)) 304 return x; 305 } 306 } while ((m = m->rm_mklist) != NULL); 307 } 308 } while (t != top); 309 return 0; 310 } 311 312 #ifdef RN_DEBUG 313 int rn_nodenum; 314 struct radix_node *rn_clist; 315 int rn_saveinfo; 316 int rn_debug = 1; 317 #endif 318 319 struct radix_node * 320 rn_newpair(v, b, nodes) 321 void *v; 322 int b; 323 struct radix_node nodes[2]; 324 { 325 register struct radix_node *tt = nodes, *t = tt + 1; 326 t->rn_b = b; t->rn_bmask = 0x80 >> (b & 7); 327 t->rn_l = tt; t->rn_off = b >> 3; 328 tt->rn_b = -1; tt->rn_key = (caddr_t)v; tt->rn_p = t; 329 tt->rn_flags = t->rn_flags = RNF_ACTIVE; 330 #ifdef RN_DEBUG 331 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 332 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 333 #endif 334 return t; 335 } 336 337 struct radix_node * 338 rn_insert(v_arg, head, dupentry, nodes) 339 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 * Find first bit at which v and t->rn_key differ 353 */ 354 { 355 register caddr_t cp2 = t->rn_key + head_off; 356 register int cmp_res; 357 caddr_t cplim = v + vlen; 358 359 while (cp < cplim) 360 if (*cp2++ != *cp++) 361 goto on1; 362 *dupentry = 1; 363 return t; 364 on1: 365 *dupentry = 0; 366 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff; 367 for (b = (cp - v) << 3; cmp_res; b--) 368 cmp_res >>= 1; 369 } 370 { 371 register struct radix_node *p, *x = top; 372 cp = v; 373 do { 374 p = x; 375 if (cp[x->rn_off] & x->rn_bmask) 376 x = x->rn_r; 377 else x = x->rn_l; 378 } while (b > (unsigned) x->rn_b); /* x->rn_b < b && x->rn_b >= 0 */ 379 #ifdef RN_DEBUG 380 if (rn_debug) 381 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p); 382 #endif 383 t = rn_newpair(v_arg, b, nodes); tt = t->rn_l; 384 if ((cp[p->rn_off] & p->rn_bmask) == 0) 385 p->rn_l = t; 386 else 387 p->rn_r = t; 388 x->rn_p = t; t->rn_p = p; /* frees x, p as temp vars below */ 389 if ((cp[t->rn_off] & t->rn_bmask) == 0) { 390 t->rn_r = x; 391 } else { 392 t->rn_r = tt; t->rn_l = x; 393 } 394 #ifdef RN_DEBUG 395 if (rn_debug) 396 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p); 397 #endif 398 } 399 return (tt); 400 } 401 402 struct radix_node * 403 rn_addmask(n_arg, search, skip) 404 int search, skip; 405 void *n_arg; 406 { 407 caddr_t netmask = (caddr_t)n_arg; 408 register struct radix_node *x; 409 register caddr_t cp, cplim; 410 register int b = 0, mlen, j; 411 int maskduplicated, m0, isnormal; 412 struct radix_node *saved_x; 413 static int last_zeroed = 0; 414 415 if ((mlen = *(u_char *)netmask) > max_keylen) 416 mlen = max_keylen; 417 if (skip == 0) 418 skip = 1; 419 if (mlen <= skip) 420 return (mask_rnhead->rnh_nodes); 421 if (skip > 1) 422 Bcopy(rn_ones + 1, addmask_key + 1, skip - 1); 423 if ((m0 = mlen) > skip) 424 Bcopy(netmask + skip, addmask_key + skip, mlen - skip); 425 /* 426 * Trim trailing zeroes. 427 */ 428 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;) 429 cp--; 430 mlen = cp - addmask_key; 431 if (mlen <= skip) { 432 if (m0 >= last_zeroed) 433 last_zeroed = mlen; 434 return (mask_rnhead->rnh_nodes); 435 } 436 if (m0 < last_zeroed) 437 Bzero(addmask_key + m0, last_zeroed - m0); 438 *addmask_key = last_zeroed = mlen; 439 x = rn_search(addmask_key, rn_masktop); 440 if (Bcmp(addmask_key, x->rn_key, mlen) != 0) 441 x = 0; 442 if (x || search) 443 return (x); 444 R_Malloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x)); 445 if ((saved_x = x) == 0) 446 return (0); 447 Bzero(x, max_keylen + 2 * sizeof (*x)); 448 netmask = cp = (caddr_t)(x + 2); 449 Bcopy(addmask_key, cp, mlen); 450 x = rn_insert(cp, mask_rnhead, &maskduplicated, x); 451 if (maskduplicated) { 452 log(LOG_ERR, "rn_addmask: mask impossibly already in tree"); 453 Free(saved_x); 454 return (x); 455 } 456 /* 457 * Calculate index of mask, and check for normalcy. 458 */ 459 cplim = netmask + mlen; isnormal = 1; 460 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;) 461 cp++; 462 if (cp != cplim) { 463 for (j = 0x80; (j & *cp) != 0; j >>= 1) 464 b++; 465 if (*cp != normal_chars[b] || cp != (cplim - 1)) 466 isnormal = 0; 467 } 468 b += (cp - netmask) << 3; 469 x->rn_b = -1 - b; 470 if (isnormal) 471 x->rn_flags |= RNF_NORMAL; 472 return (x); 473 } 474 475 static int /* XXX: arbitrary ordering for non-contiguous masks */ 476 rn_lexobetter(m_arg, n_arg) 477 void *m_arg, *n_arg; 478 { 479 register u_char *mp = m_arg, *np = n_arg, *lim; 480 481 if (*mp > *np) 482 return 1; /* not really, but need to check longer one first */ 483 if (*mp == *np) 484 for (lim = mp + *mp; mp < lim;) 485 if (*mp++ > *np++) 486 return 1; 487 return 0; 488 } 489 490 static struct radix_mask * 491 rn_new_radix_mask(tt, next) 492 register struct radix_node *tt; 493 register struct radix_mask *next; 494 { 495 register struct radix_mask *m; 496 497 MKGet(m); 498 if (m == 0) { 499 log(LOG_ERR, "Mask for route not entered\n"); 500 return (0); 501 } 502 Bzero(m, sizeof *m); 503 m->rm_b = tt->rn_b; 504 m->rm_flags = tt->rn_flags; 505 if (tt->rn_flags & RNF_NORMAL) 506 m->rm_leaf = tt; 507 else 508 m->rm_mask = tt->rn_mask; 509 m->rm_mklist = next; 510 tt->rn_mklist = m; 511 return m; 512 } 513 514 struct radix_node * 515 rn_addroute(v_arg, n_arg, head, treenodes) 516 void *v_arg, *n_arg; 517 struct radix_node_head *head; 518 struct radix_node treenodes[2]; 519 { 520 caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg; 521 register struct radix_node *t, *x = NULL, *tt; 522 struct radix_node *saved_tt, *top = head->rnh_treetop; 523 short b = 0, b_leaf = 0; 524 int keyduplicated; 525 caddr_t mmask; 526 struct radix_mask *m, **mp; 527 528 /* 529 * In dealing with non-contiguous masks, there may be 530 * many different routes which have the same mask. 531 * We will find it useful to have a unique pointer to 532 * the mask to speed avoiding duplicate references at 533 * nodes and possibly save time in calculating indices. 534 */ 535 if (netmask) { 536 if ((x = rn_addmask(netmask, 0, top->rn_off)) == 0) 537 return (0); 538 b_leaf = x->rn_b; 539 b = -1 - x->rn_b; 540 netmask = x->rn_key; 541 } 542 /* 543 * Deal with duplicated keys: attach node to previous instance 544 */ 545 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes); 546 if (keyduplicated) { 547 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) { 548 if (tt->rn_mask == netmask) 549 return (0); 550 if (netmask == 0 || 551 (tt->rn_mask && 552 ((b_leaf < tt->rn_b) || /* index(netmask) > node */ 553 rn_refines(netmask, tt->rn_mask) || 554 rn_lexobetter(netmask, tt->rn_mask)))) 555 break; 556 } 557 /* 558 * If the mask is not duplicated, we wouldn't 559 * find it among possible duplicate key entries 560 * anyway, so the above test doesn't hurt. 561 * 562 * We sort the masks for a duplicated key the same way as 563 * in a masklist -- most specific to least specific. 564 * This may require the unfortunate nuisance of relocating 565 * the head of the list. 566 */ 567 if (tt == saved_tt) { 568 struct radix_node *xx = x; 569 /* link in at head of list */ 570 (tt = treenodes)->rn_dupedkey = t; 571 tt->rn_flags = t->rn_flags; 572 tt->rn_p = x = t->rn_p; 573 if (x->rn_l == t) x->rn_l = tt; else x->rn_r = tt; 574 saved_tt = tt; x = xx; 575 } else { 576 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey; 577 t->rn_dupedkey = tt; 578 } 579 #ifdef RN_DEBUG 580 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 581 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 582 #endif 583 tt->rn_key = (caddr_t) v; 584 tt->rn_b = -1; 585 tt->rn_flags = RNF_ACTIVE; 586 } 587 /* 588 * Put mask in tree. 589 */ 590 if (netmask) { 591 tt->rn_mask = netmask; 592 tt->rn_b = x->rn_b; 593 tt->rn_flags |= x->rn_flags & RNF_NORMAL; 594 } 595 t = saved_tt->rn_p; 596 if (keyduplicated) 597 goto on2; 598 b_leaf = -1 - t->rn_b; 599 if (t->rn_r == saved_tt) x = t->rn_l; else x = t->rn_r; 600 /* Promote general routes from below */ 601 if (x->rn_b < 0) { 602 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey) 603 if (x->rn_mask && (x->rn_b >= b_leaf) && x->rn_mklist == 0) { 604 *mp = m = rn_new_radix_mask(x, 0); 605 if (m) 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) != NULL; 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) != NULL; 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, "Non-unique normal route, " 641 "mask not entered\n"); 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(v_arg, netmask_arg, head) 660 void *v_arg, *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) != NULL; 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) != 0) { 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) != NULL;) 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 log(LOG_ERR, "%s %p at %p\n", 785 "rn_delete: Orphaned Mask", m, x); 786 } 787 } 788 /* 789 * We may be holding an active internal node in the tree. 790 */ 791 x = tt + 1; 792 if (t != x) { 793 #ifndef RN_DEBUG 794 *t = *x; 795 #else 796 b = t->rn_info; *t = *x; t->rn_info = b; 797 #endif 798 t->rn_l->rn_p = t; t->rn_r->rn_p = t; 799 p = x->rn_p; 800 if (p->rn_l == x) p->rn_l = t; else p->rn_r = t; 801 } 802 out: 803 tt->rn_flags &= ~RNF_ACTIVE; 804 tt[1].rn_flags &= ~RNF_ACTIVE; 805 return (tt); 806 } 807 808 int 809 rn_walktree(h, f, w) 810 struct radix_node_head *h; 811 register int (*f) __P((struct radix_node *, void *)); 812 void *w; 813 { 814 int error; 815 struct radix_node *base, *next; 816 register struct radix_node *rn = h->rnh_treetop; 817 /* 818 * This gets complicated because we may delete the node 819 * while applying the function f to it, so we need to calculate 820 * the successor node in advance. 821 */ 822 /* First time through node, go left */ 823 while (rn->rn_b >= 0) 824 rn = rn->rn_l; 825 for (;;) { 826 base = rn; 827 /* If at right child go back up, otherwise, go right */ 828 while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0) 829 rn = rn->rn_p; 830 /* Find the next *leaf* since next node might vanish, too */ 831 for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;) 832 rn = rn->rn_l; 833 next = rn; 834 /* Process leaves */ 835 while ((rn = base) != NULL) { 836 base = rn->rn_dupedkey; 837 if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w))) 838 return (error); 839 } 840 rn = next; 841 if (rn->rn_flags & RNF_ROOT) 842 return (0); 843 } 844 /* NOTREACHED */ 845 } 846 847 int 848 rn_inithead(head, off) 849 void **head; 850 int off; 851 { 852 register struct radix_node_head *rnh; 853 register struct radix_node *t, *tt, *ttt; 854 if (*head) 855 return (1); 856 R_Malloc(rnh, struct radix_node_head *, sizeof (*rnh)); 857 if (rnh == 0) 858 return (0); 859 Bzero(rnh, sizeof (*rnh)); 860 *head = rnh; 861 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes); 862 ttt = rnh->rnh_nodes + 2; 863 t->rn_r = ttt; 864 t->rn_p = t; 865 tt = t->rn_l; 866 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE; 867 tt->rn_b = -1 - off; 868 *ttt = *tt; 869 ttt->rn_key = rn_ones; 870 rnh->rnh_addaddr = rn_addroute; 871 rnh->rnh_deladdr = rn_delete; 872 rnh->rnh_matchaddr = rn_match; 873 rnh->rnh_lookup = rn_lookup; 874 rnh->rnh_walktree = rn_walktree; 875 rnh->rnh_treetop = t; 876 return (1); 877 } 878 879 void 880 rn_init() 881 { 882 char *cp, *cplim; 883 #ifdef _KERNEL 884 struct domain *dom; 885 886 for (dom = domains; dom; dom = dom->dom_next) 887 if (dom->dom_maxrtkey > max_keylen) 888 max_keylen = dom->dom_maxrtkey; 889 #endif 890 if (max_keylen == 0) { 891 log(LOG_ERR, 892 "rn_init: radix functions require max_keylen be set\n"); 893 return; 894 } 895 R_Malloc(rn_zeros, char *, 3 * max_keylen); 896 if (rn_zeros == NULL) 897 panic("rn_init"); 898 Bzero(rn_zeros, 3 * max_keylen); 899 rn_ones = cp = rn_zeros + max_keylen; 900 addmask_key = cplim = rn_ones + max_keylen; 901 while (cp < cplim) 902 *cp++ = -1; 903 if (rn_inithead((void **)&mask_rnhead, 0) == 0) 904 panic("rn_init 2"); 905 } 906