1 /* $OpenBSD: radix.c,v 1.23 2008/05/09 07:39:31 claudio Exp $ */ 2 /* $NetBSD: radix.c,v 1.20 2003/08/07 16:32:56 agc Exp $ */ 3 4 /* 5 * Copyright (c) 1988, 1989, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)radix.c 8.6 (Berkeley) 10/17/95 33 */ 34 35 /* 36 * Routines to build and maintain radix trees for routing lookups. 37 */ 38 39 #ifndef _NET_RADIX_H_ 40 #include <sys/param.h> 41 #ifdef _KERNEL 42 #include <sys/systm.h> 43 #include <sys/malloc.h> 44 #define M_DONTWAIT M_NOWAIT 45 #include <sys/domain.h> 46 #else 47 #include <stdlib.h> 48 #endif 49 #include <sys/syslog.h> 50 #include <net/radix.h> 51 #endif 52 53 #ifndef SMALL_KERNEL 54 #include <sys/socket.h> 55 #include <net/route.h> 56 #include <net/radix_mpath.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(char *, struct radix_node *, int); 71 static int rn_lexobetter(void *, void *); 72 static struct radix_mask *rn_new_radix_mask(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 explicit 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(void *v_arg, struct radix_node *head) 111 { 112 struct radix_node *x; 113 caddr_t v; 114 115 for (x = head, v = v_arg; x->rn_b >= 0;) { 116 if (x->rn_bmask & v[x->rn_off]) 117 x = x->rn_r; 118 else 119 x = x->rn_l; 120 } 121 return (x); 122 } 123 124 struct radix_node * 125 rn_search_m(void *v_arg, struct radix_node *head, void *m_arg) 126 { 127 struct radix_node *x; 128 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(void *m_arg, void *n_arg) 142 { 143 caddr_t m = m_arg, n = n_arg; 144 caddr_t lim, lim2 = lim = n + *(u_char *)n; 145 int longer = (*(u_char *)n++) - (int)(*(u_char *)m++); 146 int masks_are_equal = 1; 147 148 if (longer > 0) 149 lim -= longer; 150 while (n < lim) { 151 if (*n & ~(*m)) 152 return 0; 153 if (*n++ != *m++) 154 masks_are_equal = 0; 155 } 156 while (n < lim2) 157 if (*n++) 158 return 0; 159 if (masks_are_equal && (longer < 0)) 160 for (lim2 = m - longer; m < lim2; ) 161 if (*m++) 162 return 1; 163 return (!masks_are_equal); 164 } 165 166 struct radix_node * 167 rn_lookup(void *v_arg, void *m_arg, struct radix_node_head *head) 168 { 169 struct radix_node *x; 170 caddr_t netmask = 0; 171 172 if (m_arg) { 173 if ((x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_off)) == 0) 174 return (0); 175 netmask = x->rn_key; 176 } 177 x = rn_match(v_arg, head); 178 if (x && netmask) { 179 while (x && x->rn_mask != netmask) 180 x = x->rn_dupedkey; 181 } 182 return x; 183 } 184 185 static int 186 rn_satisfies_leaf(char *trial, struct radix_node *leaf, int skip) 187 { 188 char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask; 189 char *cplim; 190 int length = min(*(u_char *)cp, *(u_char *)cp2); 191 192 if (cp3 == 0) 193 cp3 = rn_ones; 194 else 195 length = min(length, *(u_char *)cp3); 196 cplim = cp + length; cp3 += skip; cp2 += skip; 197 for (cp += skip; cp < cplim; cp++, cp2++, cp3++) 198 if ((*cp ^ *cp2) & *cp3) 199 return 0; 200 return 1; 201 } 202 203 struct radix_node * 204 rn_match(void *v_arg, struct radix_node_head *head) 205 { 206 caddr_t v = v_arg; 207 struct radix_node *t = head->rnh_treetop, *x; 208 caddr_t cp = v, cp2; 209 caddr_t cplim; 210 struct radix_node *saved_t, *top = t; 211 int off = t->rn_off, vlen = *(u_char *)cp, matched_off; 212 int test, b, rn_b; 213 214 /* 215 * Open code rn_search(v, top) to avoid overhead of extra 216 * subroutine call. 217 */ 218 for (; t->rn_b >= 0; ) { 219 if (t->rn_bmask & cp[t->rn_off]) 220 t = t->rn_r; 221 else 222 t = t->rn_l; 223 } 224 /* 225 * See if we match exactly as a host destination 226 * or at least learn how many bits match, for normal mask finesse. 227 * 228 * It doesn't hurt us to limit how many bytes to check 229 * to the length of the mask, since if it matches we had a genuine 230 * match and the leaf we have is the most specific one anyway; 231 * if it didn't match with a shorter length it would fail 232 * with a long one. This wins big for class B&C netmasks which 233 * are probably the most common case... 234 */ 235 if (t->rn_mask) 236 vlen = *(u_char *)t->rn_mask; 237 cp += off; cp2 = t->rn_key + off; cplim = v + vlen; 238 for (; cp < cplim; cp++, cp2++) 239 if (*cp != *cp2) 240 goto on1; 241 /* 242 * This extra grot is in case we are explicitly asked 243 * to look up the default. Ugh! 244 */ 245 if ((t->rn_flags & RNF_ROOT) && t->rn_dupedkey) 246 t = t->rn_dupedkey; 247 return t; 248 on1: 249 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */ 250 for (b = 7; (test >>= 1) > 0;) 251 b--; 252 matched_off = cp - v; 253 b += matched_off << 3; 254 rn_b = -1 - b; 255 /* 256 * If there is a host route in a duped-key chain, it will be first. 257 */ 258 if ((saved_t = t)->rn_mask == 0) 259 t = t->rn_dupedkey; 260 for (; t; t = t->rn_dupedkey) 261 /* 262 * Even if we don't match exactly as a host, 263 * we may match if the leaf we wound up at is 264 * a route to a net. 265 */ 266 if (t->rn_flags & RNF_NORMAL) { 267 if (rn_b <= t->rn_b) 268 return t; 269 } else if (rn_satisfies_leaf(v, t, matched_off)) 270 return t; 271 t = saved_t; 272 /* start searching up the tree */ 273 do { 274 struct radix_mask *m; 275 t = t->rn_p; 276 m = t->rn_mklist; 277 if (m) { 278 /* 279 * If non-contiguous masks ever become important 280 * we can restore the masking and open coding of 281 * the search and satisfaction test and put the 282 * calculation of "off" back before the "do". 283 */ 284 do { 285 if (m->rm_flags & RNF_NORMAL) { 286 if (rn_b <= m->rm_b) 287 return (m->rm_leaf); 288 } else { 289 off = min(t->rn_off, matched_off); 290 x = rn_search_m(v, t, m->rm_mask); 291 while (x && x->rn_mask != m->rm_mask) 292 x = x->rn_dupedkey; 293 if (x && rn_satisfies_leaf(v, x, off)) 294 return x; 295 } 296 m = m->rm_mklist; 297 } while (m); 298 } 299 } while (t != top); 300 return 0; 301 } 302 303 #ifdef RN_DEBUG 304 int rn_nodenum; 305 struct radix_node *rn_clist; 306 int rn_saveinfo; 307 int rn_debug = 1; 308 #endif 309 310 struct radix_node * 311 rn_newpair(void *v, int b, struct radix_node nodes[2]) 312 { 313 struct radix_node *tt = nodes, *t = tt + 1; 314 t->rn_b = b; 315 t->rn_bmask = 0x80 >> (b & 7); 316 t->rn_l = tt; 317 t->rn_off = b >> 3; 318 tt->rn_b = -1; 319 tt->rn_key = (caddr_t)v; 320 tt->rn_p = t; 321 tt->rn_flags = t->rn_flags = RNF_ACTIVE; 322 #ifdef RN_DEBUG 323 tt->rn_info = rn_nodenum++; 324 t->rn_info = rn_nodenum++; 325 tt->rn_twin = t; 326 tt->rn_ybro = rn_clist; 327 rn_clist = tt; 328 #endif 329 return t; 330 } 331 332 struct radix_node * 333 rn_insert(void *v_arg, struct radix_node_head *head, 334 int *dupentry, struct radix_node nodes[2]) 335 { 336 caddr_t v = v_arg; 337 struct radix_node *top = head->rnh_treetop; 338 int head_off = top->rn_off, vlen = (int)*((u_char *)v); 339 struct radix_node *t = rn_search(v_arg, top); 340 caddr_t cp = v + head_off; 341 int b; 342 struct radix_node *tt; 343 /* 344 * Find first bit at which v and t->rn_key differ 345 */ 346 { 347 caddr_t cp2 = t->rn_key + head_off; 348 int cmp_res; 349 caddr_t cplim = v + vlen; 350 351 while (cp < cplim) 352 if (*cp2++ != *cp++) 353 goto on1; 354 *dupentry = 1; 355 return t; 356 on1: 357 *dupentry = 0; 358 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff; 359 for (b = (cp - v) << 3; cmp_res; b--) 360 cmp_res >>= 1; 361 } 362 { 363 struct radix_node *p, *x = top; 364 cp = v; 365 do { 366 p = x; 367 if (cp[x->rn_off] & x->rn_bmask) 368 x = x->rn_r; 369 else 370 x = x->rn_l; 371 } while (b > (unsigned) x->rn_b); /* x->rn_b < b && x->rn_b >= 0 */ 372 #ifdef RN_DEBUG 373 if (rn_debug) 374 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p); 375 #endif 376 t = rn_newpair(v_arg, b, nodes); 377 tt = t->rn_l; 378 if ((cp[p->rn_off] & p->rn_bmask) == 0) 379 p->rn_l = t; 380 else 381 p->rn_r = t; 382 x->rn_p = t; 383 t->rn_p = p; /* frees x, p as temp vars below */ 384 if ((cp[t->rn_off] & t->rn_bmask) == 0) { 385 t->rn_r = x; 386 } else { 387 t->rn_r = tt; 388 t->rn_l = x; 389 } 390 #ifdef RN_DEBUG 391 if (rn_debug) 392 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p); 393 #endif 394 } 395 return (tt); 396 } 397 398 struct radix_node * 399 rn_addmask(void *n_arg, int search, int skip) 400 { 401 caddr_t netmask = (caddr_t)n_arg; 402 struct radix_node *x; 403 caddr_t cp, cplim; 404 int b = 0, mlen, j; 405 int maskduplicated, m0, isnormal; 406 struct radix_node *saved_x; 407 static int last_zeroed = 0; 408 409 if ((mlen = *(u_char *)netmask) > max_keylen) 410 mlen = max_keylen; 411 if (skip == 0) 412 skip = 1; 413 if (mlen <= skip) 414 return (mask_rnhead->rnh_nodes); 415 if (skip > 1) 416 Bcopy(rn_ones + 1, addmask_key + 1, skip - 1); 417 if ((m0 = mlen) > skip) 418 Bcopy(netmask + skip, addmask_key + skip, mlen - skip); 419 /* 420 * Trim trailing zeroes. 421 */ 422 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;) 423 cp--; 424 mlen = cp - addmask_key; 425 if (mlen <= skip) { 426 if (m0 >= last_zeroed) 427 last_zeroed = mlen; 428 return (mask_rnhead->rnh_nodes); 429 } 430 if (m0 < last_zeroed) 431 Bzero(addmask_key + m0, last_zeroed - m0); 432 *addmask_key = last_zeroed = mlen; 433 x = rn_search(addmask_key, rn_masktop); 434 if (Bcmp(addmask_key, x->rn_key, mlen) != 0) 435 x = 0; 436 if (x || search) 437 return (x); 438 R_Malloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x)); 439 if ((saved_x = x) == 0) 440 return (0); 441 Bzero(x, max_keylen + 2 * sizeof (*x)); 442 netmask = cp = (caddr_t)(x + 2); 443 Bcopy(addmask_key, cp, mlen); 444 x = rn_insert(cp, mask_rnhead, &maskduplicated, x); 445 if (maskduplicated) { 446 log(LOG_ERR, "rn_addmask: mask impossibly already in tree\n"); 447 Free(saved_x); 448 return (x); 449 } 450 /* 451 * Calculate index of mask, and check for normalcy. 452 */ 453 cplim = netmask + mlen; 454 isnormal = 1; 455 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;) 456 cp++; 457 if (cp != cplim) { 458 for (j = 0x80; (j & *cp) != 0; j >>= 1) 459 b++; 460 if (*cp != normal_chars[b] || cp != (cplim - 1)) 461 isnormal = 0; 462 } 463 b += (cp - netmask) << 3; 464 x->rn_b = -1 - b; 465 if (isnormal) 466 x->rn_flags |= RNF_NORMAL; 467 return (x); 468 } 469 470 static int /* XXX: arbitrary ordering for non-contiguous masks */ 471 rn_lexobetter(void *m_arg, void *n_arg) 472 { 473 u_char *mp = m_arg, *np = n_arg, *lim; 474 475 if (*mp > *np) 476 return 1; /* not really, but need to check longer one first */ 477 if (*mp == *np) 478 for (lim = mp + *mp; mp < lim;) 479 if (*mp++ > *np++) 480 return 1; 481 return 0; 482 } 483 484 static struct radix_mask * 485 rn_new_radix_mask(struct radix_node *tt, struct radix_mask *next) 486 { 487 struct radix_mask *m; 488 489 MKGet(m); 490 if (m == 0) { 491 log(LOG_ERR, "Mask for route not entered\n"); 492 return (0); 493 } 494 Bzero(m, sizeof *m); 495 m->rm_b = tt->rn_b; 496 m->rm_flags = tt->rn_flags; 497 if (tt->rn_flags & RNF_NORMAL) 498 m->rm_leaf = tt; 499 else 500 m->rm_mask = tt->rn_mask; 501 m->rm_mklist = next; 502 tt->rn_mklist = m; 503 return m; 504 } 505 506 struct radix_node * 507 rn_addroute(void *v_arg, void *n_arg, struct radix_node_head *head, 508 struct radix_node treenodes[2], u_int8_t prio) 509 { 510 caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg; 511 struct radix_node *t, *x = NULL, *tt; 512 struct radix_node *saved_tt, *top = head->rnh_treetop; 513 short b = 0, b_leaf = 0; 514 int keyduplicated, prioinv = -1; 515 caddr_t mmask; 516 struct radix_mask *m, **mp; 517 518 /* 519 * In dealing with non-contiguous masks, there may be 520 * many different routes which have the same mask. 521 * We will find it useful to have a unique pointer to 522 * the mask to speed avoiding duplicate references at 523 * nodes and possibly save time in calculating indices. 524 */ 525 if (netmask) { 526 if ((x = rn_addmask(netmask, 0, top->rn_off)) == 0) 527 return (0); 528 b_leaf = x->rn_b; 529 b = -1 - x->rn_b; 530 netmask = x->rn_key; 531 } 532 /* 533 * Deal with duplicated keys: attach node to previous instance 534 */ 535 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes); 536 if (keyduplicated) { 537 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) { 538 #ifndef SMALL_KERNEL 539 /* permit multipath, if enabled for the family */ 540 if (rn_mpath_capable(head) && netmask == tt->rn_mask) { 541 int mid; 542 /* 543 * Try to insert the new node in the middle 544 * of the list of any preexisting multipaths, 545 * to reduce the number of path disruptions 546 * that occur as a result of an insertion, 547 * per RFC2992. 548 * Additionally keep the list sorted by route 549 * priority. 550 */ 551 prioinv = 0; 552 tt = rn_mpath_prio(tt, prio); 553 if (((struct rtentry *)tt)->rt_priority != 554 prio) { 555 /* 556 * rn_mpath_prio returns the previous 557 * element if no element with the 558 * requested priority exists. It could 559 * be that the previous element comes 560 * with a bigger priority. 561 */ 562 if (((struct rtentry *)tt)-> 563 rt_priority > prio) 564 prioinv = 1; 565 t = tt; 566 break; 567 } 568 569 mid = rn_mpath_count(tt) / 2; 570 do { 571 t = tt; 572 tt = rn_mpath_next(tt); 573 } while (tt && --mid > 0); 574 break; 575 } 576 #endif 577 if (tt->rn_mask == netmask) 578 return (0); 579 if (netmask == 0 || 580 (tt->rn_mask && 581 ((b_leaf < tt->rn_b) || /* index(netmask) > node */ 582 rn_refines(netmask, tt->rn_mask) || 583 rn_lexobetter(netmask, tt->rn_mask)))) 584 break; 585 } 586 /* 587 * If the mask is not duplicated, we wouldn't 588 * find it among possible duplicate key entries 589 * anyway, so the above test doesn't hurt. 590 * 591 * We sort the masks for a duplicated key the same way as 592 * in a masklist -- most specific to least specific. 593 * This may require the unfortunate nuisance of relocating 594 * the head of the list. 595 * 596 * We also reverse, or doubly link the list through the 597 * parent pointer. 598 */ 599 if (tt == saved_tt && prioinv) { 600 struct radix_node *xx = x; 601 /* link in at head of list */ 602 (tt = treenodes)->rn_dupedkey = t; 603 tt->rn_flags = t->rn_flags; 604 tt->rn_p = x = t->rn_p; 605 t->rn_p = tt; 606 if (x->rn_l == t) 607 x->rn_l = tt; 608 else 609 x->rn_r = tt; 610 saved_tt = tt; 611 x = xx; 612 } else if (prioinv == 1) { 613 (tt = treenodes)->rn_dupedkey = t; 614 if (t->rn_p == NULL) 615 panic("rn_addroute: t->rn_p is NULL"); 616 t->rn_p->rn_dupedkey = tt; 617 tt->rn_p = t->rn_p; 618 t->rn_p = tt; 619 } else { 620 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey; 621 t->rn_dupedkey = tt; 622 tt->rn_p = t; 623 if (tt->rn_dupedkey) 624 tt->rn_dupedkey->rn_p = tt; 625 } 626 #ifdef RN_DEBUG 627 t=tt+1; 628 tt->rn_info = rn_nodenum++; 629 t->rn_info = rn_nodenum++; 630 tt->rn_twin = t; 631 tt->rn_ybro = rn_clist; 632 rn_clist = tt; 633 #endif 634 tt->rn_key = (caddr_t) v; 635 tt->rn_b = -1; 636 tt->rn_flags = RNF_ACTIVE; 637 } 638 /* 639 * Put mask in tree. 640 */ 641 if (netmask) { 642 tt->rn_mask = netmask; 643 tt->rn_b = x->rn_b; 644 tt->rn_flags |= x->rn_flags & RNF_NORMAL; 645 } 646 t = saved_tt->rn_p; 647 if (keyduplicated) 648 goto on2; 649 b_leaf = -1 - t->rn_b; 650 if (t->rn_r == saved_tt) 651 x = t->rn_l; 652 else 653 x = t->rn_r; 654 /* Promote general routes from below */ 655 if (x->rn_b < 0) { 656 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey) 657 if (x->rn_mask && (x->rn_b >= b_leaf) && x->rn_mklist == 0) { 658 *mp = m = rn_new_radix_mask(x, 0); 659 if (m) 660 mp = &m->rm_mklist; 661 } 662 } else if (x->rn_mklist) { 663 /* 664 * Skip over masks whose index is > that of new node 665 */ 666 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 667 if (m->rm_b >= b_leaf) 668 break; 669 t->rn_mklist = m; 670 *mp = 0; 671 } 672 on2: 673 /* Add new route to highest possible ancestor's list */ 674 if ((netmask == 0) || (b > t->rn_b )) 675 return tt; /* can't lift at all */ 676 b_leaf = tt->rn_b; 677 do { 678 x = t; 679 t = t->rn_p; 680 } while (b <= t->rn_b && x != top); 681 /* 682 * Search through routes associated with node to 683 * insert new route according to index. 684 * Need same criteria as when sorting dupedkeys to avoid 685 * double loop on deletion. 686 */ 687 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) { 688 if (m->rm_b < b_leaf) 689 continue; 690 if (m->rm_b > b_leaf) 691 break; 692 if (m->rm_flags & RNF_NORMAL) { 693 mmask = m->rm_leaf->rn_mask; 694 if (tt->rn_flags & RNF_NORMAL) { 695 log(LOG_ERR, "Non-unique normal route," 696 " mask not entered\n"); 697 return tt; 698 } 699 } else 700 mmask = m->rm_mask; 701 if (mmask == netmask) { 702 m->rm_refs++; 703 tt->rn_mklist = m; 704 return tt; 705 } 706 if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask)) 707 break; 708 } 709 *mp = rn_new_radix_mask(tt, *mp); 710 return tt; 711 } 712 713 struct radix_node * 714 rn_delete(void *v_arg, void *netmask_arg, struct radix_node_head *head, 715 struct radix_node *rn) 716 { 717 struct radix_node *t, *p, *x, *tt; 718 struct radix_mask *m, *saved_m, **mp; 719 struct radix_node *dupedkey, *saved_tt, *top; 720 caddr_t v, netmask; 721 int b, head_off, vlen; 722 723 v = v_arg; 724 netmask = netmask_arg; 725 x = head->rnh_treetop; 726 tt = rn_search(v, x); 727 head_off = x->rn_off; 728 vlen = *(u_char *)v; 729 saved_tt = tt; 730 top = x; 731 if (tt == 0 || 732 Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off)) 733 return (0); 734 /* 735 * Delete our route from mask lists. 736 */ 737 if (netmask) { 738 if ((x = rn_addmask(netmask, 1, head_off)) == 0) 739 return (0); 740 netmask = x->rn_key; 741 while (tt->rn_mask != netmask) 742 if ((tt = tt->rn_dupedkey) == 0) 743 return (0); 744 } 745 #ifndef SMALL_KERNEL 746 if (rn) { 747 while (tt != rn) 748 if ((tt = tt->rn_dupedkey) == 0) 749 return (0); 750 } 751 #endif 752 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0) 753 goto on1; 754 if (tt->rn_flags & RNF_NORMAL) { 755 if (m->rm_leaf != tt || m->rm_refs > 0) { 756 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 757 return 0; /* dangling ref could cause disaster */ 758 } 759 } else { 760 if (m->rm_mask != tt->rn_mask) { 761 log(LOG_ERR, "rn_delete: inconsistent annotation\n"); 762 goto on1; 763 } 764 if (--m->rm_refs >= 0) 765 goto on1; 766 } 767 b = -1 - tt->rn_b; 768 t = saved_tt->rn_p; 769 if (b > t->rn_b) 770 goto on1; /* Wasn't lifted at all */ 771 do { 772 x = t; 773 t = t->rn_p; 774 } while (b <= t->rn_b && x != top); 775 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) 776 if (m == saved_m) { 777 *mp = m->rm_mklist; 778 MKFree(m); 779 break; 780 } 781 if (m == 0) { 782 log(LOG_ERR, "rn_delete: couldn't find our annotation\n"); 783 if (tt->rn_flags & RNF_NORMAL) 784 return (0); /* Dangling ref to us */ 785 } 786 on1: 787 /* 788 * Eliminate us from tree 789 */ 790 if (tt->rn_flags & RNF_ROOT) 791 return (0); 792 #ifdef RN_DEBUG 793 /* Get us out of the creation list */ 794 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) 795 ; 796 if (t) t->rn_ybro = tt->rn_ybro; 797 #endif 798 t = tt->rn_p; 799 dupedkey = saved_tt->rn_dupedkey; 800 if (dupedkey) { 801 /* 802 * Here, tt is the deletion target, and 803 * saved_tt is the head of the dupedkey chain. 804 */ 805 if (tt == saved_tt) { 806 x = dupedkey; 807 x->rn_p = t; 808 if (t->rn_l == tt) 809 t->rn_l = x; 810 else 811 t->rn_r = x; 812 } else { 813 x = saved_tt; 814 t->rn_dupedkey = tt->rn_dupedkey; 815 if (tt->rn_dupedkey) 816 tt->rn_dupedkey->rn_p = t; 817 } 818 t = tt + 1; 819 if (t->rn_flags & RNF_ACTIVE) { 820 #ifndef RN_DEBUG 821 *++x = *t; 822 p = t->rn_p; 823 #else 824 b = t->rn_info; 825 *++x = *t; 826 t->rn_info = b; 827 p = t->rn_p; 828 #endif 829 if (p->rn_l == t) 830 p->rn_l = x; 831 else 832 p->rn_r = x; 833 x->rn_l->rn_p = x; 834 x->rn_r->rn_p = x; 835 } 836 goto out; 837 } 838 if (t->rn_l == tt) 839 x = t->rn_r; 840 else 841 x = t->rn_l; 842 p = t->rn_p; 843 if (p->rn_r == t) 844 p->rn_r = x; 845 else 846 p->rn_l = x; 847 x->rn_p = p; 848 /* 849 * Demote routes attached to us. 850 */ 851 if (t->rn_mklist) { 852 if (x->rn_b >= 0) { 853 for (mp = &x->rn_mklist; (m = *mp);) 854 mp = &m->rm_mklist; 855 *mp = t->rn_mklist; 856 } else { 857 /* If there are any key,mask pairs in a sibling 858 duped-key chain, some subset will appear sorted 859 in the same order attached to our mklist */ 860 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey) 861 if (m == x->rn_mklist) { 862 struct radix_mask *mm = m->rm_mklist; 863 x->rn_mklist = 0; 864 if (--(m->rm_refs) < 0) 865 MKFree(m); 866 m = mm; 867 } 868 if (m) 869 log(LOG_ERR, "%s %p at %p\n", 870 "rn_delete: Orphaned Mask", m, x); 871 } 872 } 873 /* 874 * We may be holding an active internal node in the tree. 875 */ 876 x = tt + 1; 877 if (t != x) { 878 #ifndef RN_DEBUG 879 *t = *x; 880 #else 881 b = t->rn_info; 882 *t = *x; 883 t->rn_info = b; 884 #endif 885 t->rn_l->rn_p = t; 886 t->rn_r->rn_p = t; 887 p = x->rn_p; 888 if (p->rn_l == x) 889 p->rn_l = t; 890 else 891 p->rn_r = t; 892 } 893 out: 894 tt->rn_flags &= ~RNF_ACTIVE; 895 tt[1].rn_flags &= ~RNF_ACTIVE; 896 return (tt); 897 } 898 899 int 900 rn_walktree(struct radix_node_head *h, int (*f)(struct radix_node *, void *), 901 void *w) 902 { 903 int error; 904 struct radix_node *base, *next; 905 struct radix_node *rn = h->rnh_treetop; 906 /* 907 * This gets complicated because we may delete the node 908 * while applying the function f to it, so we need to calculate 909 * the successor node in advance. 910 */ 911 /* First time through node, go left */ 912 while (rn->rn_b >= 0) 913 rn = rn->rn_l; 914 for (;;) { 915 base = rn; 916 /* If at right child go back up, otherwise, go right */ 917 while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0) 918 rn = rn->rn_p; 919 /* Find the next *leaf* since next node might vanish, too */ 920 for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;) 921 rn = rn->rn_l; 922 next = rn; 923 /* Process leaves */ 924 while ((rn = base) != NULL) { 925 base = rn->rn_dupedkey; 926 if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w))) 927 return (error); 928 } 929 rn = next; 930 if (rn->rn_flags & RNF_ROOT) 931 return (0); 932 } 933 /* NOTREACHED */ 934 } 935 936 int 937 rn_inithead(void **head, int off) 938 { 939 struct radix_node_head *rnh; 940 941 if (*head) 942 return (1); 943 R_Malloc(rnh, struct radix_node_head *, sizeof (*rnh)); 944 if (rnh == 0) 945 return (0); 946 *head = rnh; 947 return rn_inithead0(rnh, off); 948 } 949 950 int 951 rn_inithead0(struct radix_node_head *rnh, int off) 952 { 953 struct radix_node *t, *tt, *ttt; 954 955 Bzero(rnh, sizeof (*rnh)); 956 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes); 957 ttt = rnh->rnh_nodes + 2; 958 t->rn_r = ttt; 959 t->rn_p = t; 960 tt = t->rn_l; 961 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE; 962 tt->rn_b = -1 - off; 963 *ttt = *tt; 964 ttt->rn_key = rn_ones; 965 rnh->rnh_addaddr = rn_addroute; 966 rnh->rnh_deladdr = rn_delete; 967 rnh->rnh_matchaddr = rn_match; 968 rnh->rnh_lookup = rn_lookup; 969 rnh->rnh_walktree = rn_walktree; 970 rnh->rnh_treetop = t; 971 return (1); 972 } 973 974 void 975 rn_init() 976 { 977 char *cp, *cplim; 978 #ifdef _KERNEL 979 struct domain *dom; 980 981 for (dom = domains; dom; dom = dom->dom_next) 982 if (dom->dom_maxrtkey > max_keylen) 983 max_keylen = dom->dom_maxrtkey; 984 #endif 985 if (max_keylen == 0) { 986 log(LOG_ERR, 987 "rn_init: radix functions require max_keylen be set\n"); 988 return; 989 } 990 R_Malloc(rn_zeros, char *, 3 * max_keylen); 991 if (rn_zeros == NULL) 992 panic("rn_init"); 993 Bzero(rn_zeros, 3 * max_keylen); 994 rn_ones = cp = rn_zeros + max_keylen; 995 addmask_key = cplim = rn_ones + max_keylen; 996 while (cp < cplim) 997 *cp++ = -1; 998 if (rn_inithead((void *)&mask_rnhead, 0) == 0) 999 panic("rn_init 2"); 1000 } 1001