1 /* $NetBSD: radix.c,v 1.12 1997/04/02 21:17:30 christos 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 8.5 (Berkeley) 5/19/95 36 */ 37 38 /* 39 * Routines to build and maintain radix trees for routing lookups. 40 */ 41 #ifndef _NET_RADIX_H_ 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 #endif 51 #include <sys/syslog.h> 52 #include <net/radix.h> 53 #endif 54 55 int max_keylen; 56 struct radix_mask *rn_mkfreelist; 57 struct radix_node_head *mask_rnhead; 58 static char *addmask_key; 59 static char normal_chars[] = {0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1}; 60 static char *rn_zeros, *rn_ones; 61 62 #define rn_masktop (mask_rnhead->rnh_treetop) 63 #undef Bcmp 64 #define Bcmp(a, b, l) (l == 0 ? 0 : bcmp((caddr_t)(a), (caddr_t)(b), (u_long)l)) 65 66 static int rn_satsifies_leaf __P((char *, struct radix_node *, int)); 67 static int rn_lexobetter __P((void *, void *)); 68 static struct radix_mask *rn_new_radix_mask __P((struct radix_node *, 69 struct radix_mask *)); 70 71 /* 72 * The data structure for the keys is a radix tree with one way 73 * branching removed. The index rn_b at an internal node n represents a bit 74 * position to be tested. The tree is arranged so that all descendants 75 * of a node n have keys whose bits all agree up to position rn_b - 1. 76 * (We say the index of n is rn_b.) 77 * 78 * There is at least one descendant which has a one bit at position rn_b, 79 * and at least one with a zero there. 80 * 81 * A route is determined by a pair of key and mask. We require that the 82 * bit-wise logical and of the key and mask to be the key. 83 * We define the index of a route to associated with the mask to be 84 * the first bit number in the mask where 0 occurs (with bit number 0 85 * representing the highest order bit). 86 * 87 * We say a mask is normal if every bit is 0, past the index of the mask. 88 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_b, 89 * and m is a normal mask, then the route applies to every descendant of n. 90 * If the index(m) < rn_b, this implies the trailing last few bits of k 91 * before bit b are all 0, (and hence consequently true of every descendant 92 * of n), so the route applies to all descendants of the node as well. 93 * 94 * Similar logic shows that a non-normal mask m such that 95 * index(m) <= index(n) could potentially apply to many children of n. 96 * Thus, for each non-host route, we attach its mask to a list at an internal 97 * node as high in the tree as we can go. 98 * 99 * The present version of the code makes use of normal routes in short- 100 * circuiting an explict mask and compare operation when testing whether 101 * a key satisfies a normal route, and also in remembering the unique leaf 102 * that governs a subtree. 103 */ 104 105 struct radix_node * 106 rn_search(v_arg, head) 107 void *v_arg; 108 struct radix_node *head; 109 { 110 register struct radix_node *x; 111 register caddr_t v; 112 113 for (x = head, v = v_arg; x->rn_b >= 0;) { 114 if (x->rn_bmask & v[x->rn_off]) 115 x = x->rn_r; 116 else 117 x = x->rn_l; 118 } 119 return (x); 120 }; 121 122 struct radix_node * 123 rn_search_m(v_arg, head, m_arg) 124 struct radix_node *head; 125 void *v_arg, *m_arg; 126 { 127 register struct radix_node *x; 128 register caddr_t v = v_arg, m = m_arg; 129 130 for (x = head; x->rn_b >= 0;) { 131 if ((x->rn_bmask & m[x->rn_off]) && 132 (x->rn_bmask & v[x->rn_off])) 133 x = x->rn_r; 134 else 135 x = x->rn_l; 136 } 137 return x; 138 }; 139 140 int 141 rn_refines(m_arg, n_arg) 142 void *m_arg, *n_arg; 143 { 144 register caddr_t m = m_arg, n = n_arg; 145 register caddr_t lim, lim2 = lim = n + *(u_char *)n; 146 int longer = (*(u_char *)n++) - (int)(*(u_char *)m++); 147 int masks_are_equal = 1; 148 149 if (longer > 0) 150 lim -= longer; 151 while (n < lim) { 152 if (*n & ~(*m)) 153 return 0; 154 if (*n++ != *m++) 155 masks_are_equal = 0; 156 } 157 while (n < lim2) 158 if (*n++) 159 return 0; 160 if (masks_are_equal && (longer < 0)) 161 for (lim2 = m - longer; m < lim2; ) 162 if (*m++) 163 return 1; 164 return (!masks_are_equal); 165 } 166 167 struct radix_node * 168 rn_lookup(v_arg, m_arg, head) 169 void *v_arg, *m_arg; 170 struct radix_node_head *head; 171 { 172 register struct radix_node *x; 173 caddr_t netmask = 0; 174 175 if (m_arg) { 176 if ((x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_off)) == 0) 177 return (0); 178 netmask = x->rn_key; 179 } 180 x = rn_match(v_arg, head); 181 if (x && netmask) { 182 while (x && x->rn_mask != netmask) 183 x = x->rn_dupedkey; 184 } 185 return x; 186 } 187 188 static int 189 rn_satsifies_leaf(trial, leaf, skip) 190 char *trial; 191 register struct radix_node *leaf; 192 int skip; 193 { 194 register char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask; 195 char *cplim; 196 int length = min(*(u_char *)cp, *(u_char *)cp2); 197 198 if (cp3 == 0) 199 cp3 = rn_ones; 200 else 201 length = min(length, *(u_char *)cp3); 202 cplim = cp + length; cp3 += skip; cp2 += skip; 203 for (cp += skip; cp < cplim; cp++, cp2++, cp3++) 204 if ((*cp ^ *cp2) & *cp3) 205 return 0; 206 return 1; 207 } 208 209 struct radix_node * 210 rn_match(v_arg, head) 211 void *v_arg; 212 struct radix_node_head *head; 213 { 214 caddr_t v = v_arg; 215 register struct radix_node *t = head->rnh_treetop, *x; 216 register caddr_t cp = v, cp2; 217 caddr_t cplim; 218 struct radix_node *saved_t, *top = t; 219 int off = t->rn_off, vlen = *(u_char *)cp, matched_off; 220 register int test, b, rn_b; 221 222 /* 223 * Open code rn_search(v, top) to avoid overhead of extra 224 * subroutine call. 225 */ 226 for (; t->rn_b >= 0; ) { 227 if (t->rn_bmask & cp[t->rn_off]) 228 t = t->rn_r; 229 else 230 t = t->rn_l; 231 } 232 /* 233 * See if we match exactly as a host destination 234 * or at least learn how many bits match, for normal mask finesse. 235 * 236 * It doesn't hurt us to limit how many bytes to check 237 * to the length of the mask, since if it matches we had a genuine 238 * match and the leaf we have is the most specific one anyway; 239 * if it didn't match with a shorter length it would fail 240 * with a long one. This wins big for class B&C netmasks which 241 * are probably the most common case... 242 */ 243 if (t->rn_mask) 244 vlen = *(u_char *)t->rn_mask; 245 cp += off; cp2 = t->rn_key + off; cplim = v + vlen; 246 for (; cp < cplim; cp++, cp2++) 247 if (*cp != *cp2) 248 goto on1; 249 /* 250 * This extra grot is in case we are explicitly asked 251 * to look up the default. Ugh! 252 */ 253 if ((t->rn_flags & RNF_ROOT) && t->rn_dupedkey) 254 t = t->rn_dupedkey; 255 return t; 256 on1: 257 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */ 258 for (b = 7; (test >>= 1) > 0;) 259 b--; 260 matched_off = cp - v; 261 b += matched_off << 3; 262 rn_b = -1 - b; 263 /* 264 * If there is a host route in a duped-key chain, it will be first. 265 */ 266 if ((saved_t = t)->rn_mask == 0) 267 t = t->rn_dupedkey; 268 for (; t; t = t->rn_dupedkey) 269 /* 270 * Even if we don't match exactly as a host, 271 * we may match if the leaf we wound up at is 272 * a route to a net. 273 */ 274 if (t->rn_flags & RNF_NORMAL) { 275 if (rn_b <= t->rn_b) 276 return t; 277 } else if (rn_satsifies_leaf(v, t, matched_off)) 278 return t; 279 t = saved_t; 280 /* start searching up the tree */ 281 do { 282 register struct radix_mask *m; 283 t = t->rn_p; 284 m = t->rn_mklist; 285 if (m) { 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 return (m->rm_leaf); 296 } else { 297 off = min(t->rn_off, matched_off); 298 x = rn_search_m(v, t, m->rm_mask); 299 while (x && x->rn_mask != m->rm_mask) 300 x = x->rn_dupedkey; 301 if (x && rn_satsifies_leaf(v, x, off)) 302 return x; 303 } 304 m = m->rm_mklist; 305 } while (m); 306 } 307 } while (t != top); 308 return 0; 309 }; 310 311 #ifdef RN_DEBUG 312 int rn_nodenum; 313 struct radix_node *rn_clist; 314 int rn_saveinfo; 315 int rn_debug = 1; 316 #endif 317 318 struct radix_node * 319 rn_newpair(v, b, nodes) 320 void *v; 321 int b; 322 struct radix_node nodes[2]; 323 { 324 register struct radix_node *tt = nodes, *t = tt + 1; 325 t->rn_b = b; t->rn_bmask = 0x80 >> (b & 7); 326 t->rn_l = tt; t->rn_off = b >> 3; 327 tt->rn_b = -1; tt->rn_key = (caddr_t)v; tt->rn_p = t; 328 tt->rn_flags = t->rn_flags = RNF_ACTIVE; 329 #ifdef RN_DEBUG 330 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 331 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 332 #endif 333 return t; 334 } 335 336 struct radix_node * 337 rn_insert(v_arg, head, dupentry, nodes) 338 void *v_arg; 339 struct radix_node_head *head; 340 int *dupentry; 341 struct radix_node nodes[2]; 342 { 343 caddr_t v = v_arg; 344 struct radix_node *top = head->rnh_treetop; 345 int head_off = top->rn_off, vlen = (int)*((u_char *)v); 346 register struct radix_node *t = rn_search(v_arg, top); 347 register caddr_t cp = v + head_off; 348 register int b; 349 struct radix_node *tt; 350 /* 351 * Find first bit at which v and t->rn_key differ 352 */ 353 { 354 register caddr_t cp2 = t->rn_key + head_off; 355 register int cmp_res; 356 caddr_t cplim = v + vlen; 357 358 while (cp < cplim) 359 if (*cp2++ != *cp++) 360 goto on1; 361 *dupentry = 1; 362 return t; 363 on1: 364 *dupentry = 0; 365 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff; 366 for (b = (cp - v) << 3; cmp_res; b--) 367 cmp_res >>= 1; 368 } 369 { 370 register struct radix_node *p, *x = top; 371 cp = v; 372 do { 373 p = x; 374 if (cp[x->rn_off] & x->rn_bmask) 375 x = x->rn_r; 376 else x = x->rn_l; 377 } while (b > (unsigned) x->rn_b); /* x->rn_b < b && x->rn_b >= 0 */ 378 #ifdef RN_DEBUG 379 if (rn_debug) 380 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p); 381 #endif 382 t = rn_newpair(v_arg, b, nodes); tt = t->rn_l; 383 if ((cp[p->rn_off] & p->rn_bmask) == 0) 384 p->rn_l = t; 385 else 386 p->rn_r = t; 387 x->rn_p = t; t->rn_p = p; /* frees x, p as temp vars below */ 388 if ((cp[t->rn_off] & t->rn_bmask) == 0) { 389 t->rn_r = x; 390 } else { 391 t->rn_r = tt; t->rn_l = x; 392 } 393 #ifdef RN_DEBUG 394 if (rn_debug) 395 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p); 396 #endif 397 } 398 return (tt); 399 } 400 401 struct radix_node * 402 rn_addmask(n_arg, search, skip) 403 int search, skip; 404 void *n_arg; 405 { 406 caddr_t netmask = (caddr_t)n_arg; 407 register struct radix_node *x; 408 register caddr_t cp, cplim; 409 register int b = 0, mlen, j; 410 int maskduplicated, m0, isnormal; 411 struct radix_node *saved_x; 412 static int last_zeroed = 0; 413 414 if ((mlen = *(u_char *)netmask) > max_keylen) 415 mlen = max_keylen; 416 if (skip == 0) 417 skip = 1; 418 if (mlen <= skip) 419 return (mask_rnhead->rnh_nodes); 420 if (skip > 1) 421 Bcopy(rn_ones + 1, addmask_key + 1, skip - 1); 422 if ((m0 = mlen) > skip) 423 Bcopy(netmask + skip, addmask_key + skip, mlen - skip); 424 /* 425 * Trim trailing zeroes. 426 */ 427 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;) 428 cp--; 429 mlen = cp - addmask_key; 430 if (mlen <= skip) { 431 if (m0 >= last_zeroed) 432 last_zeroed = mlen; 433 return (mask_rnhead->rnh_nodes); 434 } 435 if (m0 < last_zeroed) 436 Bzero(addmask_key + m0, last_zeroed - m0); 437 *addmask_key = last_zeroed = mlen; 438 x = rn_search(addmask_key, rn_masktop); 439 if (Bcmp(addmask_key, x->rn_key, mlen) != 0) 440 x = 0; 441 if (x || search) 442 return (x); 443 R_Malloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x)); 444 if ((saved_x = x) == 0) 445 return (0); 446 Bzero(x, max_keylen + 2 * sizeof (*x)); 447 netmask = cp = (caddr_t)(x + 2); 448 Bcopy(addmask_key, cp, mlen); 449 x = rn_insert(cp, mask_rnhead, &maskduplicated, x); 450 if (maskduplicated) { 451 log(LOG_ERR, "rn_addmask: mask impossibly already in tree"); 452 Free(saved_x); 453 return (x); 454 } 455 /* 456 * Calculate index of mask, and check for normalcy. 457 */ 458 cplim = netmask + mlen; isnormal = 1; 459 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;) 460 cp++; 461 if (cp != cplim) { 462 for (j = 0x80; (j & *cp) != 0; j >>= 1) 463 b++; 464 if (*cp != normal_chars[b] || cp != (cplim - 1)) 465 isnormal = 0; 466 } 467 b += (cp - netmask) << 3; 468 x->rn_b = -1 - b; 469 if (isnormal) 470 x->rn_flags |= RNF_NORMAL; 471 return (x); 472 } 473 474 static int /* XXX: arbitrary ordering for non-contiguous masks */ 475 rn_lexobetter(m_arg, n_arg) 476 void *m_arg, *n_arg; 477 { 478 register u_char *mp = m_arg, *np = n_arg, *lim; 479 480 if (*mp > *np) 481 return 1; /* not really, but need to check longer one first */ 482 if (*mp == *np) 483 for (lim = mp + *mp; mp < lim;) 484 if (*mp++ > *np++) 485 return 1; 486 return 0; 487 } 488 489 static struct radix_mask * 490 rn_new_radix_mask(tt, next) 491 register struct radix_node *tt; 492 register struct radix_mask *next; 493 { 494 register struct radix_mask *m; 495 496 MKGet(m); 497 if (m == 0) { 498 log(LOG_ERR, "Mask for route not entered\n"); 499 return (0); 500 } 501 Bzero(m, sizeof *m); 502 m->rm_b = tt->rn_b; 503 m->rm_flags = tt->rn_flags; 504 if (tt->rn_flags & RNF_NORMAL) 505 m->rm_leaf = tt; 506 else 507 m->rm_mask = tt->rn_mask; 508 m->rm_mklist = next; 509 tt->rn_mklist = m; 510 return m; 511 } 512 513 struct radix_node * 514 rn_addroute(v_arg, n_arg, head, treenodes) 515 void *v_arg, *n_arg; 516 struct radix_node_head *head; 517 struct radix_node treenodes[2]; 518 { 519 caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg; 520 register struct radix_node *t, *x = 0, *tt; 521 struct radix_node *saved_tt, *top = head->rnh_treetop; 522 short b = 0, b_leaf = 0; 523 int keyduplicated; 524 caddr_t mmask; 525 struct radix_mask *m, **mp; 526 527 /* 528 * In dealing with non-contiguous masks, there may be 529 * many different routes which have the same mask. 530 * We will find it useful to have a unique pointer to 531 * the mask to speed avoiding duplicate references at 532 * nodes and possibly save time in calculating indices. 533 */ 534 if (netmask) { 535 if ((x = rn_addmask(netmask, 0, top->rn_off)) == 0) 536 return (0); 537 b_leaf = x->rn_b; 538 b = -1 - x->rn_b; 539 netmask = x->rn_key; 540 } 541 /* 542 * Deal with duplicated keys: attach node to previous instance 543 */ 544 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes); 545 if (keyduplicated) { 546 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) { 547 if (tt->rn_mask == netmask) 548 return (0); 549 if (netmask == 0 || 550 (tt->rn_mask && 551 ((b_leaf < tt->rn_b) || /* index(netmask) > node */ 552 rn_refines(netmask, tt->rn_mask) || 553 rn_lexobetter(netmask, tt->rn_mask)))) 554 break; 555 } 556 /* 557 * If the mask is not duplicated, we wouldn't 558 * find it among possible duplicate key entries 559 * anyway, so the above test doesn't hurt. 560 * 561 * We sort the masks for a duplicated key the same way as 562 * in a masklist -- most specific to least specific. 563 * This may require the unfortunate nuisance of relocating 564 * the head of the list. 565 * 566 * We also reverse, or doubly link the list through the 567 * parent pointer. 568 */ 569 if (tt == saved_tt) { 570 struct radix_node *xx = x; 571 /* link in at head of list */ 572 (tt = treenodes)->rn_dupedkey = t; 573 tt->rn_flags = t->rn_flags; 574 tt->rn_p = x = t->rn_p; 575 t->rn_p = tt; 576 if (x->rn_l == t) x->rn_l = tt; else x->rn_r = tt; 577 saved_tt = tt; x = xx; 578 } else { 579 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey; 580 t->rn_dupedkey = tt; 581 tt->rn_p = t; 582 if (tt->rn_dupedkey) 583 tt->rn_dupedkey->rn_p = tt; 584 } 585 #ifdef RN_DEBUG 586 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++; 587 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt; 588 #endif 589 tt->rn_key = (caddr_t) v; 590 tt->rn_b = -1; 591 tt->rn_flags = RNF_ACTIVE; 592 } 593 /* 594 * Put mask in tree. 595 */ 596 if (netmask) { 597 tt->rn_mask = netmask; 598 tt->rn_b = x->rn_b; 599 tt->rn_flags |= x->rn_flags & RNF_NORMAL; 600 } 601 t = saved_tt->rn_p; 602 if (keyduplicated) 603 goto on2; 604 b_leaf = -1 - t->rn_b; 605 if (t->rn_r == saved_tt) x = t->rn_l; else x = t->rn_r; 606 /* Promote general routes from below */ 607 if (x->rn_b < 0) { 608 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey) 609 if (x->rn_mask && (x->rn_b >= b_leaf) && x->rn_mklist == 0) { 610 *mp = m = rn_new_radix_mask(x, 0); 611 if (m) 612 mp = &m->rm_mklist; 613 } 614 } else if (x->rn_mklist) { 615 /* 616 * Skip over masks whose index is > that of new node 617 */ 618 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 619 if (m->rm_b >= b_leaf) 620 break; 621 t->rn_mklist = m; *mp = 0; 622 } 623 on2: 624 /* Add new route to highest possible ancestor's list */ 625 if ((netmask == 0) || (b > t->rn_b )) 626 return tt; /* can't lift at all */ 627 b_leaf = tt->rn_b; 628 do { 629 x = t; 630 t = t->rn_p; 631 } while (b <= t->rn_b && x != top); 632 /* 633 * Search through routes associated with node to 634 * insert new route according to index. 635 * Need same criteria as when sorting dupedkeys to avoid 636 * double loop on deletion. 637 */ 638 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) { 639 if (m->rm_b < b_leaf) 640 continue; 641 if (m->rm_b > b_leaf) 642 break; 643 if (m->rm_flags & RNF_NORMAL) { 644 mmask = m->rm_leaf->rn_mask; 645 if (tt->rn_flags & RNF_NORMAL) { 646 log(LOG_ERR, 647 "Non-unique normal route, mask not entered"); 648 return tt; 649 } 650 } else 651 mmask = m->rm_mask; 652 if (mmask == netmask) { 653 m->rm_refs++; 654 tt->rn_mklist = m; 655 return tt; 656 } 657 if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask)) 658 break; 659 } 660 *mp = rn_new_radix_mask(tt, *mp); 661 return tt; 662 } 663 664 struct radix_node * 665 rn_delete(v_arg, netmask_arg, head) 666 void *v_arg, *netmask_arg; 667 struct radix_node_head *head; 668 { 669 register struct radix_node *t, *p, *x, *tt; 670 struct radix_mask *m, *saved_m, **mp; 671 struct radix_node *dupedkey, *saved_tt, *top; 672 caddr_t v, netmask; 673 int b, head_off, vlen; 674 675 v = v_arg; 676 netmask = netmask_arg; 677 x = head->rnh_treetop; 678 tt = rn_search(v, x); 679 head_off = x->rn_off; 680 vlen = *(u_char *)v; 681 saved_tt = tt; 682 top = x; 683 if (tt == 0 || 684 Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off)) 685 return (0); 686 /* 687 * Delete our route from mask lists. 688 */ 689 if (netmask) { 690 if ((x = rn_addmask(netmask, 1, head_off)) == 0) 691 return (0); 692 netmask = x->rn_key; 693 while (tt->rn_mask != netmask) 694 if ((tt = tt->rn_dupedkey) == 0) 695 return (0); 696 } 697 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0) 698 goto on1; 699 if (tt->rn_flags & RNF_NORMAL) { 700 if (m->rm_leaf != tt || m->rm_refs > 0) { 701 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 702 return 0; /* dangling ref could cause disaster */ 703 } 704 } else { 705 if (m->rm_mask != tt->rn_mask) { 706 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 707 goto on1; 708 } 709 if (--m->rm_refs >= 0) 710 goto on1; 711 } 712 b = -1 - tt->rn_b; 713 t = saved_tt->rn_p; 714 if (b > t->rn_b) 715 goto on1; /* Wasn't lifted at all */ 716 do { 717 x = t; 718 t = t->rn_p; 719 } while (b <= t->rn_b && x != top); 720 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 721 if (m == saved_m) { 722 *mp = m->rm_mklist; 723 MKFree(m); 724 break; 725 } 726 if (m == 0) { 727 log(LOG_ERR, "rn_delete: couldn't find our annotation\n"); 728 if (tt->rn_flags & RNF_NORMAL) 729 return (0); /* Dangling ref to us */ 730 } 731 on1: 732 /* 733 * Eliminate us from tree 734 */ 735 if (tt->rn_flags & RNF_ROOT) 736 return (0); 737 #ifdef RN_DEBUG 738 /* Get us out of the creation list */ 739 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {} 740 if (t) t->rn_ybro = tt->rn_ybro; 741 #endif 742 t = tt->rn_p; 743 dupedkey = saved_tt->rn_dupedkey; 744 if (dupedkey) { 745 /* 746 * Here, tt is the deletion target, and 747 * saved_tt is the head of the dupedkey chain. 748 */ 749 if (tt == saved_tt) { 750 x = dupedkey; x->rn_p = t; 751 if (t->rn_l == tt) t->rn_l = x; else t->rn_r = x; 752 } else { 753 /* find node in front of tt on the chain */ 754 for (x = p = saved_tt; p && p->rn_dupedkey != tt;) 755 p = p->rn_dupedkey; 756 if (p) { 757 p->rn_dupedkey = tt->rn_dupedkey; 758 if (tt->rn_dupedkey) 759 tt->rn_dupedkey->rn_p = p; 760 } else log(LOG_ERR, "rn_delete: couldn't find us\n"); 761 } 762 t = tt + 1; 763 if (t->rn_flags & RNF_ACTIVE) { 764 #ifndef RN_DEBUG 765 *++x = *t; p = t->rn_p; 766 #else 767 b = t->rn_info; *++x = *t; t->rn_info = b; p = t->rn_p; 768 #endif 769 if (p->rn_l == t) p->rn_l = x; else p->rn_r = x; 770 x->rn_l->rn_p = x; x->rn_r->rn_p = x; 771 } 772 goto out; 773 } 774 if (t->rn_l == tt) x = t->rn_r; else x = t->rn_l; 775 p = t->rn_p; 776 if (p->rn_r == t) p->rn_r = x; else p->rn_l = x; 777 x->rn_p = p; 778 /* 779 * Demote routes attached to us. 780 */ 781 if (t->rn_mklist) { 782 if (x->rn_b >= 0) { 783 for (mp = &x->rn_mklist; (m = *mp);) 784 mp = &m->rm_mklist; 785 *mp = t->rn_mklist; 786 } else { 787 /* If there are any key,mask pairs in a sibling 788 duped-key chain, some subset will appear sorted 789 in the same order attached to our mklist */ 790 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey) 791 if (m == x->rn_mklist) { 792 struct radix_mask *mm = m->rm_mklist; 793 x->rn_mklist = 0; 794 if (--(m->rm_refs) < 0) 795 MKFree(m); 796 m = mm; 797 } 798 if (m) 799 log(LOG_ERR, "%s %p at %p\n", 800 "rn_delete: Orphaned Mask", m, x); 801 } 802 } 803 /* 804 * We may be holding an active internal node in the tree. 805 */ 806 x = tt + 1; 807 if (t != x) { 808 #ifndef RN_DEBUG 809 *t = *x; 810 #else 811 b = t->rn_info; *t = *x; t->rn_info = b; 812 #endif 813 t->rn_l->rn_p = t; t->rn_r->rn_p = t; 814 p = x->rn_p; 815 if (p->rn_l == x) p->rn_l = t; else p->rn_r = t; 816 } 817 out: 818 tt->rn_flags &= ~RNF_ACTIVE; 819 tt[1].rn_flags &= ~RNF_ACTIVE; 820 return (tt); 821 } 822 823 int 824 rn_walktree(h, f, w) 825 struct radix_node_head *h; 826 register int (*f) __P((struct radix_node *, void *)); 827 void *w; 828 { 829 int error; 830 struct radix_node *base, *next; 831 register struct radix_node *rn = h->rnh_treetop; 832 /* 833 * This gets complicated because we may delete the node 834 * while applying the function f to it, so we need to calculate 835 * the successor node in advance. 836 */ 837 /* First time through node, go left */ 838 while (rn->rn_b >= 0) 839 rn = rn->rn_l; 840 for (;;) { 841 base = rn; 842 /* If at right child go back up, otherwise, go right */ 843 while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0) 844 rn = rn->rn_p; 845 /* Find the next *leaf* since next node might vanish, too */ 846 for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;) 847 rn = rn->rn_l; 848 next = rn; 849 /* Process leaves */ 850 while ((rn = base) != NULL) { 851 base = rn->rn_dupedkey; 852 if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w))) 853 return (error); 854 } 855 rn = next; 856 if (rn->rn_flags & RNF_ROOT) 857 return (0); 858 } 859 /* NOTREACHED */ 860 } 861 862 int 863 rn_inithead(head, off) 864 void **head; 865 int off; 866 { 867 register struct radix_node_head *rnh; 868 register struct radix_node *t, *tt, *ttt; 869 if (*head) 870 return (1); 871 R_Malloc(rnh, struct radix_node_head *, sizeof (*rnh)); 872 if (rnh == 0) 873 return (0); 874 Bzero(rnh, sizeof (*rnh)); 875 *head = rnh; 876 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes); 877 ttt = rnh->rnh_nodes + 2; 878 t->rn_r = ttt; 879 t->rn_p = t; 880 tt = t->rn_l; 881 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE; 882 tt->rn_b = -1 - off; 883 *ttt = *tt; 884 ttt->rn_key = rn_ones; 885 rnh->rnh_addaddr = rn_addroute; 886 rnh->rnh_deladdr = rn_delete; 887 rnh->rnh_matchaddr = rn_match; 888 rnh->rnh_lookup = rn_lookup; 889 rnh->rnh_walktree = rn_walktree; 890 rnh->rnh_treetop = t; 891 return (1); 892 } 893 894 void 895 rn_init() 896 { 897 char *cp, *cplim; 898 #ifdef _KERNEL 899 struct domain *dom; 900 901 for (dom = domains; dom; dom = dom->dom_next) 902 if (dom->dom_maxrtkey > max_keylen) 903 max_keylen = dom->dom_maxrtkey; 904 #endif 905 if (max_keylen == 0) { 906 log(LOG_ERR, 907 "rn_init: radix functions require max_keylen be set\n"); 908 return; 909 } 910 R_Malloc(rn_zeros, char *, 3 * max_keylen); 911 if (rn_zeros == NULL) 912 panic("rn_init"); 913 Bzero(rn_zeros, 3 * max_keylen); 914 rn_ones = cp = rn_zeros + max_keylen; 915 addmask_key = cplim = rn_ones + max_keylen; 916 while (cp < cplim) 917 *cp++ = -1; 918 if (rn_inithead((void **)&mask_rnhead, 0) == 0) 919 panic("rn_init 2"); 920 } 921