1 /* $NetBSD: radix.c,v 1.18 2001/11/12 23:49:47 lukem Exp $ */ 2 3 /* 4 * Copyright (c) 1988, 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)radix.c 8.6 (Berkeley) 10/17/95 36 */ 37 38 /* 39 * Routines to build and maintain radix trees for routing lookups. 40 */ 41 42 #include <sys/cdefs.h> 43 __KERNEL_RCSID(0, "$NetBSD: radix.c,v 1.18 2001/11/12 23:49:47 lukem Exp $"); 44 45 #ifndef _NET_RADIX_H_ 46 #include <sys/param.h> 47 #ifdef _KERNEL 48 #include <sys/systm.h> 49 #include <sys/malloc.h> 50 #define M_DONTWAIT M_NOWAIT 51 #include <sys/domain.h> 52 #else 53 #include <stdlib.h> 54 #endif 55 #include <sys/syslog.h> 56 #include <net/radix.h> 57 #endif 58 59 int max_keylen; 60 struct radix_mask *rn_mkfreelist; 61 struct radix_node_head *mask_rnhead; 62 static char *addmask_key; 63 static char normal_chars[] = {0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1}; 64 static char *rn_zeros, *rn_ones; 65 66 #define rn_masktop (mask_rnhead->rnh_treetop) 67 #undef Bcmp 68 #define Bcmp(a, b, l) (l == 0 ? 0 : bcmp((caddr_t)(a), (caddr_t)(b), (u_long)l)) 69 70 static int rn_satisfies_leaf __P((char *, struct radix_node *, int)); 71 static int rn_lexobetter __P((void *, void *)); 72 static struct radix_mask *rn_new_radix_mask __P((struct radix_node *, 73 struct radix_mask *)); 74 75 /* 76 * The data structure for the keys is a radix tree with one way 77 * branching removed. The index rn_b at an internal node n represents a bit 78 * position to be tested. The tree is arranged so that all descendants 79 * of a node n have keys whose bits all agree up to position rn_b - 1. 80 * (We say the index of n is rn_b.) 81 * 82 * There is at least one descendant which has a one bit at position rn_b, 83 * and at least one with a zero there. 84 * 85 * A route is determined by a pair of key and mask. We require that the 86 * bit-wise logical and of the key and mask to be the key. 87 * We define the index of a route to associated with the mask to be 88 * the first bit number in the mask where 0 occurs (with bit number 0 89 * representing the highest order bit). 90 * 91 * We say a mask is normal if every bit is 0, past the index of the mask. 92 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_b, 93 * and m is a normal mask, then the route applies to every descendant of n. 94 * If the index(m) < rn_b, this implies the trailing last few bits of k 95 * before bit b are all 0, (and hence consequently true of every descendant 96 * of n), so the route applies to all descendants of the node as well. 97 * 98 * Similar logic shows that a non-normal mask m such that 99 * index(m) <= index(n) could potentially apply to many children of n. 100 * Thus, for each non-host route, we attach its mask to a list at an internal 101 * node as high in the tree as we can go. 102 * 103 * The present version of the code makes use of normal routes in short- 104 * circuiting an explict mask and compare operation when testing whether 105 * a key satisfies a normal route, and also in remembering the unique leaf 106 * that governs a subtree. 107 */ 108 109 struct radix_node * 110 rn_search(v_arg, head) 111 void *v_arg; 112 struct radix_node *head; 113 { 114 struct radix_node *x; 115 caddr_t v; 116 117 for (x = head, v = v_arg; x->rn_b >= 0;) { 118 if (x->rn_bmask & v[x->rn_off]) 119 x = x->rn_r; 120 else 121 x = x->rn_l; 122 } 123 return (x); 124 } 125 126 struct radix_node * 127 rn_search_m(v_arg, head, m_arg) 128 struct radix_node *head; 129 void *v_arg, *m_arg; 130 { 131 struct radix_node *x; 132 caddr_t v = v_arg, m = m_arg; 133 134 for (x = head; x->rn_b >= 0;) { 135 if ((x->rn_bmask & m[x->rn_off]) && 136 (x->rn_bmask & v[x->rn_off])) 137 x = x->rn_r; 138 else 139 x = x->rn_l; 140 } 141 return x; 142 } 143 144 int 145 rn_refines(m_arg, n_arg) 146 void *m_arg, *n_arg; 147 { 148 caddr_t m = m_arg, n = n_arg; 149 caddr_t lim, lim2 = lim = n + *(u_char *)n; 150 int longer = (*(u_char *)n++) - (int)(*(u_char *)m++); 151 int masks_are_equal = 1; 152 153 if (longer > 0) 154 lim -= longer; 155 while (n < lim) { 156 if (*n & ~(*m)) 157 return 0; 158 if (*n++ != *m++) 159 masks_are_equal = 0; 160 } 161 while (n < lim2) 162 if (*n++) 163 return 0; 164 if (masks_are_equal && (longer < 0)) 165 for (lim2 = m - longer; m < lim2; ) 166 if (*m++) 167 return 1; 168 return (!masks_are_equal); 169 } 170 171 struct radix_node * 172 rn_lookup(v_arg, m_arg, head) 173 void *v_arg, *m_arg; 174 struct radix_node_head *head; 175 { 176 struct radix_node *x; 177 caddr_t netmask = 0; 178 179 if (m_arg) { 180 if ((x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_off)) == 0) 181 return (0); 182 netmask = x->rn_key; 183 } 184 x = rn_match(v_arg, head); 185 if (x && netmask) { 186 while (x && x->rn_mask != netmask) 187 x = x->rn_dupedkey; 188 } 189 return x; 190 } 191 192 static int 193 rn_satisfies_leaf(trial, leaf, skip) 194 char *trial; 195 struct radix_node *leaf; 196 int skip; 197 { 198 char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask; 199 char *cplim; 200 int length = min(*(u_char *)cp, *(u_char *)cp2); 201 202 if (cp3 == 0) 203 cp3 = rn_ones; 204 else 205 length = min(length, *(u_char *)cp3); 206 cplim = cp + length; cp3 += skip; cp2 += skip; 207 for (cp += skip; cp < cplim; cp++, cp2++, cp3++) 208 if ((*cp ^ *cp2) & *cp3) 209 return 0; 210 return 1; 211 } 212 213 struct radix_node * 214 rn_match(v_arg, head) 215 void *v_arg; 216 struct radix_node_head *head; 217 { 218 caddr_t v = v_arg; 219 struct radix_node *t = head->rnh_treetop, *x; 220 caddr_t cp = v, cp2; 221 caddr_t cplim; 222 struct radix_node *saved_t, *top = t; 223 int off = t->rn_off, vlen = *(u_char *)cp, matched_off; 224 int test, b, rn_b; 225 226 /* 227 * Open code rn_search(v, top) to avoid overhead of extra 228 * subroutine call. 229 */ 230 for (; t->rn_b >= 0; ) { 231 if (t->rn_bmask & cp[t->rn_off]) 232 t = t->rn_r; 233 else 234 t = t->rn_l; 235 } 236 /* 237 * See if we match exactly as a host destination 238 * or at least learn how many bits match, for normal mask finesse. 239 * 240 * It doesn't hurt us to limit how many bytes to check 241 * to the length of the mask, since if it matches we had a genuine 242 * match and the leaf we have is the most specific one anyway; 243 * if it didn't match with a shorter length it would fail 244 * with a long one. This wins big for class B&C netmasks which 245 * are probably the most common case... 246 */ 247 if (t->rn_mask) 248 vlen = *(u_char *)t->rn_mask; 249 cp += off; cp2 = t->rn_key + off; cplim = v + vlen; 250 for (; cp < cplim; cp++, cp2++) 251 if (*cp != *cp2) 252 goto on1; 253 /* 254 * This extra grot is in case we are explicitly asked 255 * to look up the default. Ugh! 256 */ 257 if ((t->rn_flags & RNF_ROOT) && t->rn_dupedkey) 258 t = t->rn_dupedkey; 259 return t; 260 on1: 261 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */ 262 for (b = 7; (test >>= 1) > 0;) 263 b--; 264 matched_off = cp - v; 265 b += matched_off << 3; 266 rn_b = -1 - b; 267 /* 268 * If there is a host route in a duped-key chain, it will be first. 269 */ 270 if ((saved_t = t)->rn_mask == 0) 271 t = t->rn_dupedkey; 272 for (; t; t = t->rn_dupedkey) 273 /* 274 * Even if we don't match exactly as a host, 275 * we may match if the leaf we wound up at is 276 * a route to a net. 277 */ 278 if (t->rn_flags & RNF_NORMAL) { 279 if (rn_b <= t->rn_b) 280 return t; 281 } else if (rn_satisfies_leaf(v, t, matched_off)) 282 return t; 283 t = saved_t; 284 /* start searching up the tree */ 285 do { 286 struct radix_mask *m; 287 t = t->rn_p; 288 m = t->rn_mklist; 289 if (m) { 290 /* 291 * If non-contiguous masks ever become important 292 * we can restore the masking and open coding of 293 * the search and satisfaction test and put the 294 * calculation of "off" back before the "do". 295 */ 296 do { 297 if (m->rm_flags & RNF_NORMAL) { 298 if (rn_b <= m->rm_b) 299 return (m->rm_leaf); 300 } else { 301 off = min(t->rn_off, matched_off); 302 x = rn_search_m(v, t, m->rm_mask); 303 while (x && x->rn_mask != m->rm_mask) 304 x = x->rn_dupedkey; 305 if (x && rn_satisfies_leaf(v, x, off)) 306 return x; 307 } 308 m = m->rm_mklist; 309 } while (m); 310 } 311 } while (t != top); 312 return 0; 313 } 314 315 #ifdef RN_DEBUG 316 int rn_nodenum; 317 struct radix_node *rn_clist; 318 int rn_saveinfo; 319 int rn_debug = 1; 320 #endif 321 322 struct radix_node * 323 rn_newpair(v, b, nodes) 324 void *v; 325 int b; 326 struct radix_node nodes[2]; 327 { 328 struct radix_node *tt = nodes, *t = tt + 1; 329 t->rn_b = b; t->rn_bmask = 0x80 >> (b & 7); 330 t->rn_l = tt; t->rn_off = b >> 3; 331 tt->rn_b = -1; tt->rn_key = (caddr_t)v; tt->rn_p = t; 332 tt->rn_flags = t->rn_flags = RNF_ACTIVE; 333 #ifdef RN_DEBUG 334 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 335 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 336 #endif 337 return t; 338 } 339 340 struct radix_node * 341 rn_insert(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 struct radix_node *t = rn_search(v_arg, top); 351 caddr_t cp = v + head_off; 352 int b; 353 struct radix_node *tt; 354 /* 355 * Find first bit at which v and t->rn_key differ 356 */ 357 { 358 caddr_t cp2 = t->rn_key + head_off; 359 int cmp_res; 360 caddr_t cplim = v + vlen; 361 362 while (cp < cplim) 363 if (*cp2++ != *cp++) 364 goto on1; 365 *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 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 x = x->rn_l; 381 } while (b > (unsigned) x->rn_b); /* x->rn_b < b && x->rn_b >= 0 */ 382 #ifdef RN_DEBUG 383 if (rn_debug) 384 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p); 385 #endif 386 t = rn_newpair(v_arg, b, nodes); 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; t->rn_p = p; /* frees x, p as temp vars below */ 392 if ((cp[t->rn_off] & t->rn_bmask) == 0) { 393 t->rn_r = x; 394 } else { 395 t->rn_r = tt; t->rn_l = x; 396 } 397 #ifdef RN_DEBUG 398 if (rn_debug) 399 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p); 400 #endif 401 } 402 return (tt); 403 } 404 405 struct radix_node * 406 rn_addmask(n_arg, search, skip) 407 int search, skip; 408 void *n_arg; 409 { 410 caddr_t netmask = (caddr_t)n_arg; 411 struct radix_node *x; 412 caddr_t cp, cplim; 413 int b = 0, mlen, j; 414 int maskduplicated, m0, isnormal; 415 struct radix_node *saved_x; 416 static int last_zeroed = 0; 417 418 if ((mlen = *(u_char *)netmask) > max_keylen) 419 mlen = max_keylen; 420 if (skip == 0) 421 skip = 1; 422 if (mlen <= skip) 423 return (mask_rnhead->rnh_nodes); 424 if (skip > 1) 425 Bcopy(rn_ones + 1, addmask_key + 1, skip - 1); 426 if ((m0 = mlen) > skip) 427 Bcopy(netmask + skip, addmask_key + skip, mlen - skip); 428 /* 429 * Trim trailing zeroes. 430 */ 431 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;) 432 cp--; 433 mlen = cp - addmask_key; 434 if (mlen <= skip) { 435 if (m0 >= last_zeroed) 436 last_zeroed = mlen; 437 return (mask_rnhead->rnh_nodes); 438 } 439 if (m0 < last_zeroed) 440 Bzero(addmask_key + m0, last_zeroed - m0); 441 *addmask_key = last_zeroed = mlen; 442 x = rn_search(addmask_key, rn_masktop); 443 if (Bcmp(addmask_key, x->rn_key, mlen) != 0) 444 x = 0; 445 if (x || search) 446 return (x); 447 R_Malloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x)); 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\n"); 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(m_arg, n_arg) 480 void *m_arg, *n_arg; 481 { 482 u_char *mp = m_arg, *np = n_arg, *lim; 483 484 if (*mp > *np) 485 return 1; /* not really, but need to check longer one first */ 486 if (*mp == *np) 487 for (lim = mp + *mp; mp < lim;) 488 if (*mp++ > *np++) 489 return 1; 490 return 0; 491 } 492 493 static struct radix_mask * 494 rn_new_radix_mask(tt, next) 495 struct radix_node *tt; 496 struct radix_mask *next; 497 { 498 struct radix_mask *m; 499 500 MKGet(m); 501 if (m == 0) { 502 log(LOG_ERR, "Mask for route not entered\n"); 503 return (0); 504 } 505 Bzero(m, sizeof *m); 506 m->rm_b = tt->rn_b; 507 m->rm_flags = tt->rn_flags; 508 if (tt->rn_flags & RNF_NORMAL) 509 m->rm_leaf = tt; 510 else 511 m->rm_mask = tt->rn_mask; 512 m->rm_mklist = next; 513 tt->rn_mklist = m; 514 return m; 515 } 516 517 struct radix_node * 518 rn_addroute(v_arg, n_arg, head, treenodes) 519 void *v_arg, *n_arg; 520 struct radix_node_head *head; 521 struct radix_node treenodes[2]; 522 { 523 caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg; 524 struct radix_node *t, *x = 0, *tt; 525 struct radix_node *saved_tt, *top = head->rnh_treetop; 526 short b = 0, b_leaf = 0; 527 int keyduplicated; 528 caddr_t mmask; 529 struct radix_mask *m, **mp; 530 531 /* 532 * In dealing with non-contiguous masks, there may be 533 * many different routes which have the same mask. 534 * We will find it useful to have a unique pointer to 535 * the mask to speed avoiding duplicate references at 536 * nodes and possibly save time in calculating indices. 537 */ 538 if (netmask) { 539 if ((x = rn_addmask(netmask, 0, top->rn_off)) == 0) 540 return (0); 541 b_leaf = x->rn_b; 542 b = -1 - x->rn_b; 543 netmask = x->rn_key; 544 } 545 /* 546 * Deal with duplicated keys: attach node to previous instance 547 */ 548 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes); 549 if (keyduplicated) { 550 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) { 551 if (tt->rn_mask == netmask) 552 return (0); 553 if (netmask == 0 || 554 (tt->rn_mask && 555 ((b_leaf < tt->rn_b) || /* index(netmask) > node */ 556 rn_refines(netmask, tt->rn_mask) || 557 rn_lexobetter(netmask, tt->rn_mask)))) 558 break; 559 } 560 /* 561 * If the mask is not duplicated, we wouldn't 562 * find it among possible duplicate key entries 563 * anyway, so the above test doesn't hurt. 564 * 565 * We sort the masks for a duplicated key the same way as 566 * in a masklist -- most specific to least specific. 567 * This may require the unfortunate nuisance of relocating 568 * the head of the list. 569 * 570 * We also reverse, or doubly link the list through the 571 * parent pointer. 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 t->rn_p = tt; 580 if (x->rn_l == t) x->rn_l = tt; else x->rn_r = tt; 581 saved_tt = tt; x = xx; 582 } else { 583 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey; 584 t->rn_dupedkey = tt; 585 tt->rn_p = t; 586 if (tt->rn_dupedkey) 587 tt->rn_dupedkey->rn_p = tt; 588 } 589 #ifdef RN_DEBUG 590 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 591 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 592 #endif 593 tt->rn_key = (caddr_t) v; 594 tt->rn_b = -1; 595 tt->rn_flags = RNF_ACTIVE; 596 } 597 /* 598 * Put mask in tree. 599 */ 600 if (netmask) { 601 tt->rn_mask = netmask; 602 tt->rn_b = x->rn_b; 603 tt->rn_flags |= x->rn_flags & RNF_NORMAL; 604 } 605 t = saved_tt->rn_p; 606 if (keyduplicated) 607 goto on2; 608 b_leaf = -1 - t->rn_b; 609 if (t->rn_r == saved_tt) x = t->rn_l; else x = t->rn_r; 610 /* Promote general routes from below */ 611 if (x->rn_b < 0) { 612 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey) 613 if (x->rn_mask && (x->rn_b >= b_leaf) && x->rn_mklist == 0) { 614 *mp = m = rn_new_radix_mask(x, 0); 615 if (m) 616 mp = &m->rm_mklist; 617 } 618 } else if (x->rn_mklist) { 619 /* 620 * Skip over masks whose index is > that of new node 621 */ 622 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 623 if (m->rm_b >= b_leaf) 624 break; 625 t->rn_mklist = m; *mp = 0; 626 } 627 on2: 628 /* Add new route to highest possible ancestor's list */ 629 if ((netmask == 0) || (b > t->rn_b )) 630 return tt; /* can't lift at all */ 631 b_leaf = tt->rn_b; 632 do { 633 x = t; 634 t = t->rn_p; 635 } while (b <= t->rn_b && x != top); 636 /* 637 * Search through routes associated with node to 638 * insert new route according to index. 639 * Need same criteria as when sorting dupedkeys to avoid 640 * double loop on deletion. 641 */ 642 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) { 643 if (m->rm_b < b_leaf) 644 continue; 645 if (m->rm_b > b_leaf) 646 break; 647 if (m->rm_flags & RNF_NORMAL) { 648 mmask = m->rm_leaf->rn_mask; 649 if (tt->rn_flags & RNF_NORMAL) { 650 log(LOG_ERR, "Non-unique normal route," 651 " mask not entered\n"); 652 return tt; 653 } 654 } else 655 mmask = m->rm_mask; 656 if (mmask == netmask) { 657 m->rm_refs++; 658 tt->rn_mklist = m; 659 return tt; 660 } 661 if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask)) 662 break; 663 } 664 *mp = rn_new_radix_mask(tt, *mp); 665 return tt; 666 } 667 668 struct radix_node * 669 rn_delete(v_arg, netmask_arg, head) 670 void *v_arg, *netmask_arg; 671 struct radix_node_head *head; 672 { 673 struct radix_node *t, *p, *x, *tt; 674 struct radix_mask *m, *saved_m, **mp; 675 struct radix_node *dupedkey, *saved_tt, *top; 676 caddr_t v, netmask; 677 int b, head_off, vlen; 678 679 v = v_arg; 680 netmask = netmask_arg; 681 x = head->rnh_treetop; 682 tt = rn_search(v, x); 683 head_off = x->rn_off; 684 vlen = *(u_char *)v; 685 saved_tt = tt; 686 top = x; 687 if (tt == 0 || 688 Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off)) 689 return (0); 690 /* 691 * Delete our route from mask lists. 692 */ 693 if (netmask) { 694 if ((x = rn_addmask(netmask, 1, head_off)) == 0) 695 return (0); 696 netmask = x->rn_key; 697 while (tt->rn_mask != netmask) 698 if ((tt = tt->rn_dupedkey) == 0) 699 return (0); 700 } 701 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0) 702 goto on1; 703 if (tt->rn_flags & RNF_NORMAL) { 704 if (m->rm_leaf != tt || m->rm_refs > 0) { 705 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 706 return 0; /* dangling ref could cause disaster */ 707 } 708 } else { 709 if (m->rm_mask != tt->rn_mask) { 710 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 711 goto on1; 712 } 713 if (--m->rm_refs >= 0) 714 goto on1; 715 } 716 b = -1 - tt->rn_b; 717 t = saved_tt->rn_p; 718 if (b > t->rn_b) 719 goto on1; /* Wasn't lifted at all */ 720 do { 721 x = t; 722 t = t->rn_p; 723 } while (b <= t->rn_b && x != top); 724 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 725 if (m == saved_m) { 726 *mp = m->rm_mklist; 727 MKFree(m); 728 break; 729 } 730 if (m == 0) { 731 log(LOG_ERR, "rn_delete: couldn't find our annotation\n"); 732 if (tt->rn_flags & RNF_NORMAL) 733 return (0); /* Dangling ref to us */ 734 } 735 on1: 736 /* 737 * Eliminate us from tree 738 */ 739 if (tt->rn_flags & RNF_ROOT) 740 return (0); 741 #ifdef RN_DEBUG 742 /* Get us out of the creation list */ 743 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {} 744 if (t) t->rn_ybro = tt->rn_ybro; 745 #endif 746 t = tt->rn_p; 747 dupedkey = saved_tt->rn_dupedkey; 748 if (dupedkey) { 749 /* 750 * Here, tt is the deletion target, and 751 * saved_tt is the head of the dupedkey chain. 752 */ 753 if (tt == saved_tt) { 754 x = dupedkey; x->rn_p = t; 755 if (t->rn_l == tt) t->rn_l = x; else t->rn_r = x; 756 } else { 757 /* find node in front of tt on the chain */ 758 for (x = p = saved_tt; p && p->rn_dupedkey != tt;) 759 p = p->rn_dupedkey; 760 if (p) { 761 p->rn_dupedkey = tt->rn_dupedkey; 762 if (tt->rn_dupedkey) 763 tt->rn_dupedkey->rn_p = p; 764 } else log(LOG_ERR, "rn_delete: couldn't find us\n"); 765 } 766 t = tt + 1; 767 if (t->rn_flags & RNF_ACTIVE) { 768 #ifndef RN_DEBUG 769 *++x = *t; p = t->rn_p; 770 #else 771 b = t->rn_info; *++x = *t; t->rn_info = b; p = t->rn_p; 772 #endif 773 if (p->rn_l == t) p->rn_l = x; else p->rn_r = x; 774 x->rn_l->rn_p = x; x->rn_r->rn_p = x; 775 } 776 goto out; 777 } 778 if (t->rn_l == tt) x = t->rn_r; else x = t->rn_l; 779 p = t->rn_p; 780 if (p->rn_r == t) p->rn_r = x; else p->rn_l = x; 781 x->rn_p = p; 782 /* 783 * Demote routes attached to us. 784 */ 785 if (t->rn_mklist) { 786 if (x->rn_b >= 0) { 787 for (mp = &x->rn_mklist; (m = *mp);) 788 mp = &m->rm_mklist; 789 *mp = t->rn_mklist; 790 } else { 791 /* If there are any key,mask pairs in a sibling 792 duped-key chain, some subset will appear sorted 793 in the same order attached to our mklist */ 794 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey) 795 if (m == x->rn_mklist) { 796 struct radix_mask *mm = m->rm_mklist; 797 x->rn_mklist = 0; 798 if (--(m->rm_refs) < 0) 799 MKFree(m); 800 m = mm; 801 } 802 if (m) 803 log(LOG_ERR, "%s %p at %p\n", 804 "rn_delete: Orphaned Mask", m, x); 805 } 806 } 807 /* 808 * We may be holding an active internal node in the tree. 809 */ 810 x = tt + 1; 811 if (t != x) { 812 #ifndef RN_DEBUG 813 *t = *x; 814 #else 815 b = t->rn_info; *t = *x; t->rn_info = b; 816 #endif 817 t->rn_l->rn_p = t; t->rn_r->rn_p = t; 818 p = x->rn_p; 819 if (p->rn_l == x) p->rn_l = t; else p->rn_r = t; 820 } 821 out: 822 tt->rn_flags &= ~RNF_ACTIVE; 823 tt[1].rn_flags &= ~RNF_ACTIVE; 824 return (tt); 825 } 826 827 int 828 rn_walktree(h, f, w) 829 struct radix_node_head *h; 830 int (*f) __P((struct radix_node *, void *)); 831 void *w; 832 { 833 int error; 834 struct radix_node *base, *next; 835 struct radix_node *rn = h->rnh_treetop; 836 /* 837 * This gets complicated because we may delete the node 838 * while applying the function f to it, so we need to calculate 839 * the successor node in advance. 840 */ 841 /* First time through node, go left */ 842 while (rn->rn_b >= 0) 843 rn = rn->rn_l; 844 for (;;) { 845 base = rn; 846 /* If at right child go back up, otherwise, go right */ 847 while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0) 848 rn = rn->rn_p; 849 /* Find the next *leaf* since next node might vanish, too */ 850 for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;) 851 rn = rn->rn_l; 852 next = rn; 853 /* Process leaves */ 854 while ((rn = base) != NULL) { 855 base = rn->rn_dupedkey; 856 if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w))) 857 return (error); 858 } 859 rn = next; 860 if (rn->rn_flags & RNF_ROOT) 861 return (0); 862 } 863 /* NOTREACHED */ 864 } 865 866 int 867 rn_inithead(head, off) 868 void **head; 869 int off; 870 { 871 struct radix_node_head *rnh; 872 873 if (*head) 874 return (1); 875 R_Malloc(rnh, struct radix_node_head *, sizeof (*rnh)); 876 if (rnh == 0) 877 return (0); 878 *head = rnh; 879 return rn_inithead0(rnh, off); 880 } 881 882 int 883 rn_inithead0(rnh, off) 884 struct radix_node_head *rnh; 885 int off; 886 { 887 struct radix_node *t, *tt, *ttt; 888 889 Bzero(rnh, sizeof (*rnh)); 890 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes); 891 ttt = rnh->rnh_nodes + 2; 892 t->rn_r = ttt; 893 t->rn_p = t; 894 tt = t->rn_l; 895 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE; 896 tt->rn_b = -1 - off; 897 *ttt = *tt; 898 ttt->rn_key = rn_ones; 899 rnh->rnh_addaddr = rn_addroute; 900 rnh->rnh_deladdr = rn_delete; 901 rnh->rnh_matchaddr = rn_match; 902 rnh->rnh_lookup = rn_lookup; 903 rnh->rnh_walktree = rn_walktree; 904 rnh->rnh_treetop = t; 905 return (1); 906 } 907 908 void 909 rn_init() 910 { 911 char *cp, *cplim; 912 #ifdef _KERNEL 913 struct domain *dom; 914 915 for (dom = domains; dom; dom = dom->dom_next) 916 if (dom->dom_maxrtkey > max_keylen) 917 max_keylen = dom->dom_maxrtkey; 918 #endif 919 if (max_keylen == 0) { 920 log(LOG_ERR, 921 "rn_init: radix functions require max_keylen be set\n"); 922 return; 923 } 924 R_Malloc(rn_zeros, char *, 3 * max_keylen); 925 if (rn_zeros == NULL) 926 panic("rn_init"); 927 Bzero(rn_zeros, 3 * max_keylen); 928 rn_ones = cp = rn_zeros + max_keylen; 929 addmask_key = cplim = rn_ones + max_keylen; 930 while (cp < cplim) 931 *cp++ = -1; 932 if (rn_inithead((void **)&mask_rnhead, 0) == 0) 933 panic("rn_init 2"); 934 } 935