sys/net/radix.c

   1 /*
   2  * Copyright (c) 1988, 1989, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  *      @(#)radix.c     8.4 (Berkeley) 11/2/94
  34  * $FreeBSD: src/sys/net/radix.c,v 1.20.2.3 2002/04/28 05:40:25 suz Exp $
  35  * $DragonFly: src/sys/net/radix.c,v 1.14 2006/12/22 23:44:54 swildner Exp $
  36  */
  37
  38 /*
  39  * Routines to build and maintain radix trees for routing lookups.
  40  */
  41 #include <sys/param.h>
  42 #ifdef  _KERNEL
  43 #include <sys/systm.h>
  44 #include <sys/malloc.h>
  45 #include <sys/domain.h>
  46 #else
  47 #include <stdlib.h>
  48 #endif
  49 #include <sys/syslog.h>
  50 #include <net/radix.h>
  51
  52 /*
  53  * The arguments to the radix functions are really counted byte arrays with
  54  * the length in the first byte.  struct sockaddr's fit this type structurally.
  55  */
  56 #define clen(c) (*(u_char *)(c))
  57
  58 static int rn_walktree_from(struct radix_node_head *h, char *a, char *m,
  59                             walktree_f_t *f, void *w);
  60 static int rn_walktree(struct radix_node_head *, walktree_f_t *, void *);
  61
  62 static struct radix_node
  63     *rn_insert(char *, struct radix_node_head *, boolean_t *,
  64                struct radix_node [2]),
  65     *rn_newpair(char *, int, struct radix_node[2]),
  66     *rn_search(const char *, struct radix_node *),
  67     *rn_search_m(const char *, struct radix_node *, const char *);
  68
  69 static struct radix_mask *rn_mkfreelist;
  70 static struct radix_node_head *mask_rnhead;
  71
  72 static int max_keylen;
  73 static char *rn_zeros, *rn_ones;
  74
  75 static int rn_lexobetter(char *m, char *n);
  76 static struct radix_mask *
  77     rn_new_radix_mask(struct radix_node *tt, struct radix_mask *nextmask);
  78 static boolean_t
  79     rn_satisfies_leaf(char *trial, struct radix_node *leaf, int skip);
  80
  81 static __inline struct radix_mask *
  82 MKGet(struct radix_mask **l)
  83 {
  84         struct radix_mask *m;
  85
  86         if (*l != NULL) {
  87                 m = *l;
  88                 *l = m->rm_next;
  89         } else {
  90                 R_Malloc(m, struct radix_mask *, sizeof *m);
  91         }
  92         return m;
  93 }
  94
  95 static __inline void
  96 MKFree(struct radix_mask **l, struct radix_mask *m)
  97 {
  98         m->rm_next = *l;
  99         *l = m;
 100 }
 101
 102 /*
 103  * The data structure for the keys is a radix tree with one way
 104  * branching removed.  The index rn_bit at an internal node n represents a bit
 105  * position to be tested.  The tree is arranged so that all descendants
 106  * of a node n have keys whose bits all agree up to position rn_bit - 1.
 107  * (We say the index of n is rn_bit.)
 108  *
 109  * There is at least one descendant which has a one bit at position rn_bit,
 110  * and at least one with a zero there.
 111  *
 112  * A route is determined by a pair of key and mask.  We require that the
 113  * bit-wise logical and of the key and mask to be the key.
 114  * We define the index of a route to associated with the mask to be
 115  * the first bit number in the mask where 0 occurs (with bit number 0
 116  * representing the highest order bit).
 117  *
 118  * We say a mask is normal if every bit is 0, past the index of the mask.
 119  * If a node n has a descendant (k, m) with index(m) == index(n) == rn_bit,
 120  * and m is a normal mask, then the route applies to every descendant of n.
 121  * If the index(m) < rn_bit, this implies the trailing last few bits of k
 122  * before bit b are all 0, (and hence consequently true of every descendant
 123  * of n), so the route applies to all descendants of the node as well.
 124  *
 125  * Similar logic shows that a non-normal mask m such that
 126  * index(m) <= index(n) could potentially apply to many children of n.
 127  * Thus, for each non-host route, we attach its mask to a list at an internal
 128  * node as high in the tree as we can go.
 129  *
 130  * The present version of the code makes use of normal routes in short-
 131  * circuiting an explict mask and compare operation when testing whether
 132  * a key satisfies a normal route, and also in remembering the unique leaf
 133  * that governs a subtree.
 134  */
 135
 136 static struct radix_node *
 137 rn_search(const char *v, struct radix_node *head)
 138 {
 139         struct radix_node *x;
 140
 141         x = head;
 142         while (x->rn_bit >= 0) {
 143                 if (x->rn_bmask & v[x->rn_offset])
 144                         x = x->rn_right;
 145                 else
 146                         x = x->rn_left;
 147         }
 148         return (x);
 149 }
 150
 151 static struct radix_node *
 152 rn_search_m(const char *v, struct radix_node *head, const char *m)
 153 {
 154         struct radix_node *x;
 155
 156         for (x = head; x->rn_bit >= 0;) {
 157                 if ((x->rn_bmask & m[x->rn_offset]) &&
 158                     (x->rn_bmask & v[x->rn_offset]))
 159                         x = x->rn_right;
 160                 else
 161                         x = x->rn_left;
 162         }
 163         return x;
 164 }
 165
 166 boolean_t
 167 rn_refines(char *m, char *n)
 168 {
 169         char *lim, *lim2;
 170         int longer = clen(n++) - clen(m++);
 171         boolean_t masks_are_equal = TRUE;
 172
 173         lim2 = lim = n + clen(n);
 174         if (longer > 0)
 175                 lim -= longer;
 176         while (n < lim) {
 177                 if (*n & ~(*m))
 178                         return FALSE;
 179                 if (*n++ != *m++)
 180                         masks_are_equal = FALSE;
 181         }
 182         while (n < lim2)
 183                 if (*n++)
 184                         return FALSE;
 185         if (masks_are_equal && (longer < 0))
 186                 for (lim2 = m - longer; m < lim2; )
 187                         if (*m++)
 188                                 return TRUE;
 189         return (!masks_are_equal);
 190 }
 191
 192 struct radix_node *
 193 rn_lookup(char *key, char *mask, struct radix_node_head *head)
 194 {
 195         struct radix_node *x;
 196         char *netmask = NULL;
 197
 198         if (mask != NULL) {
 199                 x = rn_addmask(mask, TRUE, head->rnh_treetop->rn_offset);
 200                 if (x == NULL)
 201                         return (NULL);
 202                 netmask = x->rn_key;
 203         }
 204         x = rn_match(key, head);
 205         if (x != NULL && netmask != NULL) {
 206                 while (x != NULL && x->rn_mask != netmask)
 207                         x = x->rn_dupedkey;
 208         }
 209         return x;
 210 }
 211
 212 static boolean_t
 213 rn_satisfies_leaf(char *trial, struct radix_node *leaf, int skip)
 214 {
 215         char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask;
 216         char *cplim;
 217         int length = min(clen(cp), clen(cp2));
 218
 219         if (cp3 == NULL)
 220                 cp3 = rn_ones;
 221         else
 222                 length = min(length, clen(cp3));
 223         cplim = cp + length;
 224         cp3 += skip;
 225         cp2 += skip;
 226         for (cp += skip; cp < cplim; cp++, cp2++, cp3++)
 227                 if ((*cp ^ *cp2) & *cp3)
 228                         return FALSE;
 229         return TRUE;
 230 }
 231
 232 struct radix_node *
 233 rn_match(char *key, struct radix_node_head *head)
 234 {
 235         struct radix_node *t, *x;
 236         char *cp = key, *cp2;
 237         char *cplim;
 238         struct radix_node *saved_t, *top = head->rnh_treetop;
 239         int off = top->rn_offset, klen, matched_off;
 240         int test, b, rn_bit;
 241
 242         t = rn_search(key, top);
 243         /*
 244          * See if we match exactly as a host destination
 245          * or at least learn how many bits match, for normal mask finesse.
 246          *
 247          * It doesn't hurt us to limit how many bytes to check
 248          * to the length of the mask, since if it matches we had a genuine
 249          * match and the leaf we have is the most specific one anyway;
 250          * if it didn't match with a shorter length it would fail
 251          * with a long one.  This wins big for class B&C netmasks which
 252          * are probably the most common case...
 253          */
 254         if (t->rn_mask != NULL)
 255                 klen = clen(t->rn_mask);
 256         else
 257                 klen = clen(key);
 258         cp += off; cp2 = t->rn_key + off; cplim = key + klen;
 259         for (; cp < cplim; cp++, cp2++)
 260                 if (*cp != *cp2)
 261                         goto on1;
 262         /*
 263          * This extra grot is in case we are explicitly asked
 264          * to look up the default.  Ugh!
 265          *
 266          * Never return the root node itself, it seems to cause a
 267          * lot of confusion.
 268          */
 269         if (t->rn_flags & RNF_ROOT)
 270                 t = t->rn_dupedkey;
 271         return t;
 272 on1:
 273         test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */
 274         for (b = 7; (test >>= 1) > 0;)
 275                 b--;
 276         matched_off = cp - key;
 277         b += matched_off << 3;
 278         rn_bit = -1 - b;
 279         /*
 280          * If there is a host route in a duped-key chain, it will be first.
 281          */
 282         if ((saved_t = t)->rn_mask == NULL)
 283                 t = t->rn_dupedkey;
 284         for (; t; t = t->rn_dupedkey) {
 285                 /*
 286                  * Even if we don't match exactly as a host,
 287                  * we may match if the leaf we wound up at is
 288                  * a route to a net.
 289                  */
 290                 if (t->rn_flags & RNF_NORMAL) {
 291                         if (rn_bit <= t->rn_bit)
 292                                 return t;
 293                 } else if (rn_satisfies_leaf(key, t, matched_off))
 294                                 return t;
 295         }
 296         t = saved_t;
 297         /* start searching up the tree */
 298         do {
 299                 struct radix_mask *m;
 300
 301                 t = t->rn_parent;
 302                 /*
 303                  * If non-contiguous masks ever become important
 304                  * we can restore the masking and open coding of
 305                  * the search and satisfaction test and put the
 306                  * calculation of "off" back before the "do".
 307                  */
 308                 m = t->rn_mklist;
 309                 while (m != NULL) {
 310                         if (m->rm_flags & RNF_NORMAL) {
 311                                 if (rn_bit <= m->rm_bit)
 312                                         return (m->rm_leaf);
 313                         } else {
 314                                 off = min(t->rn_offset, matched_off);
 315                                 x = rn_search_m(key, t, m->rm_mask);
 316                                 while (x != NULL && x->rn_mask != m->rm_mask)
 317                                         x = x->rn_dupedkey;
 318                                 if (x && rn_satisfies_leaf(key, x, off))
 319                                         return x;
 320                         }
 321                         m = m->rm_next;
 322                 }
 323         } while (t != top);
 324         return NULL;
 325 }
 326
 327 #ifdef RN_DEBUG
 328 int rn_nodenum;
 329 struct radix_node *rn_clist;
 330 int rn_saveinfo;
 331 boolean_t rn_debug =  TRUE;
 332 #endif
 333
 334 static struct radix_node *
 335 rn_newpair(char *key, int indexbit, struct radix_node nodes[2])
 336 {
 337         struct radix_node *leaf = &nodes[0], *interior = &nodes[1];
 338
 339         interior->rn_bit = indexbit;
 340         interior->rn_bmask = 0x80 >> (indexbit & 0x7);
 341         interior->rn_offset = indexbit >> 3;
 342         interior->rn_left = leaf;
 343         interior->rn_mklist = NULL;
 344
 345         leaf->rn_bit = -1;
 346         leaf->rn_key = key;
 347         leaf->rn_parent = interior;
 348         leaf->rn_flags = interior->rn_flags = RNF_ACTIVE;
 349         leaf->rn_mklist = NULL;
 350
 351 #ifdef RN_DEBUG
 352         leaf->rn_info = rn_nodenum++;
 353         interior->rn_info = rn_nodenum++;
 354         leaf->rn_twin = interior;
 355         leaf->rn_ybro = rn_clist;
 356         rn_clist = leaf;
 357 #endif
 358         return interior;
 359 }
 360
 361 static struct radix_node *
 362 rn_insert(char *key, struct radix_node_head *head, boolean_t *dupentry,
 363           struct radix_node nodes[2])
 364 {
 365         struct radix_node *top = head->rnh_treetop;
 366         int head_off = top->rn_offset, klen = clen(key);
 367         struct radix_node *t = rn_search(key, top);
 368         char *cp = key + head_off;
 369         int b;
 370         struct radix_node *tt;
 371
 372         /*
 373          * Find first bit at which the key and t->rn_key differ
 374          */
 375     {
 376         char *cp2 = t->rn_key + head_off;
 377         int cmp_res;
 378         char *cplim = key + klen;
 379
 380         while (cp < cplim)
 381                 if (*cp2++ != *cp++)
 382                         goto on1;
 383         *dupentry = TRUE;
 384         return t;
 385 on1:
 386         *dupentry = FALSE;
 387         cmp_res = (cp[-1] ^ cp2[-1]) & 0xff;
 388         for (b = (cp - key) << 3; cmp_res; b--)
 389                 cmp_res >>= 1;
 390     }
 391     {
 392         struct radix_node *p, *x = top;
 393
 394         cp = key;
 395         do {
 396                 p = x;
 397                 if (cp[x->rn_offset] & x->rn_bmask)
 398                         x = x->rn_right;
 399                 else
 400                         x = x->rn_left;
 401         } while (b > (unsigned) x->rn_bit);
 402                                 /* x->rn_bit < b && x->rn_bit >= 0 */
 403 #ifdef RN_DEBUG
 404         if (rn_debug)
 405                 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p);
 406 #endif
 407         t = rn_newpair(key, b, nodes);
 408         tt = t->rn_left;
 409         if ((cp[p->rn_offset] & p->rn_bmask) == 0)
 410                 p->rn_left = t;
 411         else
 412                 p->rn_right = t;
 413         x->rn_parent = t;
 414         t->rn_parent = p; /* frees x, p as temp vars below */
 415         if ((cp[t->rn_offset] & t->rn_bmask) == 0) {
 416                 t->rn_right = x;
 417         } else {
 418                 t->rn_right = tt;
 419                 t->rn_left = x;
 420         }
 421 #ifdef RN_DEBUG
 422         if (rn_debug)
 423                 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p);
 424 #endif
 425     }
 426         return (tt);
 427 }
 428
 429 struct radix_node *
 430 rn_addmask(char *netmask, boolean_t search, int skip)
 431 {
 432         struct radix_node *x, *saved_x;
 433         char *cp, *cplim;
 434         int b = 0, mlen, m0, j;
 435         boolean_t maskduplicated, isnormal;
 436         static int last_zeroed = 0;
 437         char *addmask_key;
 438
 439         if ((mlen = clen(netmask)) > max_keylen)
 440                 mlen = max_keylen;
 441         if (skip == 0)
 442                 skip = 1;
 443         if (mlen <= skip)
 444                 return (mask_rnhead->rnh_nodes);
 445         R_Malloc(addmask_key, char *, max_keylen);
 446         if (addmask_key == NULL)
 447                 return NULL;
 448         if (skip > 1)
 449                 bcopy(rn_ones + 1, addmask_key + 1, skip - 1);
 450         if ((m0 = mlen) > skip)
 451                 bcopy(netmask + skip, addmask_key + skip, mlen - skip);
 452         /*
 453          * Trim trailing zeroes.
 454          */
 455         for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;)
 456                 cp--;
 457         mlen = cp - addmask_key;
 458         if (mlen <= skip) {
 459                 if (m0 >= last_zeroed)
 460                         last_zeroed = mlen;
 461                 Free(addmask_key);
 462                 return (mask_rnhead->rnh_nodes);
 463         }
 464         if (m0 < last_zeroed)
 465                 bzero(addmask_key + m0, last_zeroed - m0);
 466         *addmask_key = last_zeroed = mlen;
 467         x = rn_search(addmask_key, mask_rnhead->rnh_treetop);
 468         if (bcmp(addmask_key, x->rn_key, mlen) != 0)
 469                 x = NULL;
 470         if (x != NULL || search)
 471                 goto out;
 472         R_Malloc(x, struct radix_node *, max_keylen + 2 * (sizeof *x));
 473         if ((saved_x = x) == NULL)
 474                 goto out;
 475         bzero(x, max_keylen + 2 * (sizeof *x));
 476         netmask = cp = (char *)(x + 2);
 477         bcopy(addmask_key, cp, mlen);
 478         x = rn_insert(cp, mask_rnhead, &maskduplicated, x);
 479         if (maskduplicated) {
 480                 log(LOG_ERR, "rn_addmask: mask impossibly already in tree");
 481                 Free(saved_x);
 482                 goto out;
 483         }
 484         /*
 485          * Calculate index of mask, and check for normalcy.
 486          */
 487         isnormal = TRUE;
 488         cplim = netmask + mlen;
 489         for (cp = netmask + skip; cp < cplim && clen(cp) == 0xff;)
 490                 cp++;
 491         if (cp != cplim) {
 492                 static const char normal_chars[] = {
 493                         0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1
 494                 };
 495
 496                 for (j = 0x80; (j & *cp) != 0; j >>= 1)
 497                         b++;
 498                 if (*cp != normal_chars[b] || cp != (cplim - 1))
 499                         isnormal = FALSE;
 500         }
 501         b += (cp - netmask) << 3;
 502         x->rn_bit = -1 - b;
 503         if (isnormal)
 504                 x->rn_flags |= RNF_NORMAL;
 505 out:
 506         Free(addmask_key);
 507         return (x);
 508 }
 509
 510 /* XXX: arbitrary ordering for non-contiguous masks */
 511 static boolean_t
 512 rn_lexobetter(char *mp, char *np)
 513 {
 514         char *lim;
 515
 516         if ((unsigned) *mp > (unsigned) *np)
 517                 return TRUE;/* not really, but need to check longer one first */
 518         if (*mp == *np)
 519                 for (lim = mp + clen(mp); mp < lim;)
 520                         if (*mp++ > *np++)
 521                                 return TRUE;
 522         return FALSE;
 523 }
 524
 525 static struct radix_mask *
 526 rn_new_radix_mask(struct radix_node *tt, struct radix_mask *nextmask)
 527 {
 528         struct radix_mask *m;
 529
 530         m = MKGet(&rn_mkfreelist);
 531         if (m == NULL) {
 532                 log(LOG_ERR, "Mask for route not entered\n");
 533                 return (NULL);
 534         }
 535         bzero(m, sizeof *m);
 536         m->rm_bit = tt->rn_bit;
 537         m->rm_flags = tt->rn_flags;
 538         if (tt->rn_flags & RNF_NORMAL)
 539                 m->rm_leaf = tt;
 540         else
 541                 m->rm_mask = tt->rn_mask;
 542         m->rm_next = nextmask;
 543         tt->rn_mklist = m;
 544         return m;
 545 }
 546
 547 struct radix_node *
 548 rn_addroute(char *key, char *netmask, struct radix_node_head *head,
 549             struct radix_node treenodes[2])
 550 {
 551         struct radix_node *t, *x = NULL, *tt;
 552         struct radix_node *saved_tt, *top = head->rnh_treetop;
 553         short b = 0, b_leaf = 0;
 554         boolean_t keyduplicated;
 555         char *mmask;
 556         struct radix_mask *m, **mp;
 557
 558         /*
 559          * In dealing with non-contiguous masks, there may be
 560          * many different routes which have the same mask.
 561          * We will find it useful to have a unique pointer to
 562          * the mask to speed avoiding duplicate references at
 563          * nodes and possibly save time in calculating indices.
 564          */
 565         if (netmask != NULL)  {
 566                 if ((x = rn_addmask(netmask, FALSE, top->rn_offset)) == NULL)
 567                         return (NULL);
 568                 b_leaf = x->rn_bit;
 569                 b = -1 - x->rn_bit;
 570                 netmask = x->rn_key;
 571         }
 572         /*
 573          * Deal with duplicated keys: attach node to previous instance
 574          */
 575         saved_tt = tt = rn_insert(key, head, &keyduplicated, treenodes);
 576         if (keyduplicated) {
 577                 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) {
 578                         if (tt->rn_mask == netmask)
 579                                 return (NULL);
 580                         if (netmask == NULL ||
 581                             (tt->rn_mask &&
 582                              ((b_leaf < tt->rn_bit) /* index(netmask) > node */
 583                               || rn_refines(netmask, tt->rn_mask)
 584                               || rn_lexobetter(netmask, tt->rn_mask))))
 585                                 break;
 586                 }
 587                 /*
 588                  * If the mask is not duplicated, we wouldn't
 589                  * find it among possible duplicate key entries
 590                  * anyway, so the above test doesn't hurt.
 591                  *
 592                  * We sort the masks for a duplicated key the same way as
 593                  * in a masklist -- most specific to least specific.
 594                  * This may require the unfortunate nuisance of relocating
 595                  * the head of the list.
 596                  */
 597                 if (tt == saved_tt) {
 598                         struct  radix_node *xx = x;
 599                         /* link in at head of list */
 600                         (tt = treenodes)->rn_dupedkey = t;
 601                         tt->rn_flags = t->rn_flags;
 602                         tt->rn_parent = x = t->rn_parent;
 603                         t->rn_parent = tt;                      /* parent */
 604                         if (x->rn_left == t)
 605                                 x->rn_left = tt;
 606                         else
 607                                 x->rn_right = tt;
 608                         saved_tt = tt; x = xx;
 609                 } else {
 610                         (tt = treenodes)->rn_dupedkey = t->rn_dupedkey;
 611                         t->rn_dupedkey = tt;
 612                         tt->rn_parent = t;                      /* parent */
 613                         if (tt->rn_dupedkey != NULL)            /* parent */
 614                                 tt->rn_dupedkey->rn_parent = tt; /* parent */
 615                 }
 616 #ifdef RN_DEBUG
 617                 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
 618                 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt;
 619 #endif
 620                 tt->rn_key = key;
 621                 tt->rn_bit = -1;
 622                 tt->rn_flags = RNF_ACTIVE;
 623         }
 624         /*
 625          * Put mask in tree.
 626          */
 627         if (netmask != NULL) {
 628                 tt->rn_mask = netmask;
 629                 tt->rn_bit = x->rn_bit;
 630                 tt->rn_flags |= x->rn_flags & RNF_NORMAL;
 631         }
 632         t = saved_tt->rn_parent;
 633         if (keyduplicated)
 634                 goto on2;
 635         b_leaf = -1 - t->rn_bit;
 636         if (t->rn_right == saved_tt)
 637                 x = t->rn_left;
 638         else
 639                 x = t->rn_right;
 640         /* Promote general routes from below */
 641         if (x->rn_bit < 0) {
 642                 mp = &t->rn_mklist;
 643                 while (x != NULL) {
 644                         if (x->rn_mask != NULL &&
 645                             x->rn_bit >= b_leaf &&
 646                             x->rn_mklist == NULL) {
 647                                 *mp = m = rn_new_radix_mask(x, NULL);
 648                                 if (m != NULL)
 649                                         mp = &m->rm_next;
 650                         }
 651                         x = x->rn_dupedkey;
 652                 }
 653         } else if (x->rn_mklist != NULL) {
 654                 /*
 655                  * Skip over masks whose index is > that of new node
 656                  */
 657                 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_next)
 658                         if (m->rm_bit >= b_leaf)
 659                                 break;
 660                 t->rn_mklist = m;
 661                 *mp = NULL;
 662         }
 663 on2:
 664         /* Add new route to highest possible ancestor's list */
 665         if ((netmask == NULL) || (b > t->rn_bit ))
 666                 return tt; /* can't lift at all */
 667         b_leaf = tt->rn_bit;
 668         do {
 669                 x = t;
 670                 t = t->rn_parent;
 671         } while (b <= t->rn_bit && x != top);
 672         /*
 673          * Search through routes associated with node to
 674          * insert new route according to index.
 675          * Need same criteria as when sorting dupedkeys to avoid
 676          * double loop on deletion.
 677          */
 678         for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_next) {
 679                 if (m->rm_bit < b_leaf)
 680                         continue;
 681                 if (m->rm_bit > b_leaf)
 682                         break;
 683                 if (m->rm_flags & RNF_NORMAL) {
 684                         mmask = m->rm_leaf->rn_mask;
 685                         if (tt->rn_flags & RNF_NORMAL) {
 686                             log(LOG_ERR,
 687                                 "Non-unique normal route, mask not entered\n");
 688                                 return tt;
 689                         }
 690                 } else
 691                         mmask = m->rm_mask;
 692                 if (mmask == netmask) {
 693                         m->rm_refs++;
 694                         tt->rn_mklist = m;
 695                         return tt;
 696                 }
 697                 if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask))
 698                         break;
 699         }
 700         *mp = rn_new_radix_mask(tt, *mp);
 701         return tt;
 702 }
 703
 704 struct radix_node *
 705 rn_delete(char *key, char *netmask, struct radix_node_head *head)
 706 {
 707         struct radix_node *t, *p, *x, *tt;
 708         struct radix_mask *m, *saved_m, **mp;
 709         struct radix_node *dupedkey, *saved_tt, *top;
 710         int b, head_off, klen;
 711
 712         x = head->rnh_treetop;
 713         tt = rn_search(key, x);
 714         head_off = x->rn_offset;
 715         klen =  clen(key);
 716         saved_tt = tt;
 717         top = x;
 718         if (tt == NULL ||
 719             bcmp(key + head_off, tt->rn_key + head_off, klen - head_off))
 720                 return (NULL);
 721         /*
 722          * Delete our route from mask lists.
 723          */
 724         if (netmask != NULL) {
 725                 if ((x = rn_addmask(netmask, TRUE, head_off)) == NULL)
 726                         return (NULL);
 727                 netmask = x->rn_key;
 728                 while (tt->rn_mask != netmask)
 729                         if ((tt = tt->rn_dupedkey) == NULL)
 730                                 return (NULL);
 731         }
 732         if (tt->rn_mask == NULL || (saved_m = m = tt->rn_mklist) == NULL)
 733                 goto on1;
 734         if (tt->rn_flags & RNF_NORMAL) {
 735                 if (m->rm_leaf != tt || m->rm_refs > 0) {
 736                         log(LOG_ERR, "rn_delete: inconsistent annotation\n");
 737                         return (NULL);  /* dangling ref could cause disaster */
 738                 }
 739         } else {
 740                 if (m->rm_mask != tt->rn_mask) {
 741                         log(LOG_ERR, "rn_delete: inconsistent annotation\n");
 742                         goto on1;
 743                 }
 744                 if (--m->rm_refs >= 0)
 745                         goto on1;
 746         }
 747         b = -1 - tt->rn_bit;
 748         t = saved_tt->rn_parent;
 749         if (b > t->rn_bit)
 750                 goto on1; /* Wasn't lifted at all */
 751         do {
 752                 x = t;
 753                 t = t->rn_parent;
 754         } while (b <= t->rn_bit && x != top);
 755         for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_next)
 756                 if (m == saved_m) {
 757                         *mp = m->rm_next;
 758                         MKFree(&rn_mkfreelist, m);
 759                         break;
 760                 }
 761         if (m == NULL) {
 762                 log(LOG_ERR, "rn_delete: couldn't find our annotation\n");
 763                 if (tt->rn_flags & RNF_NORMAL)
 764                         return (NULL); /* Dangling ref to us */
 765         }
 766 on1:
 767         /*
 768          * Eliminate us from tree
 769          */
 770         if (tt->rn_flags & RNF_ROOT)
 771                 return (NULL);
 772 #ifdef RN_DEBUG
 773         /* Get us out of the creation list */
 774         for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {}
 775         if (t) t->rn_ybro = tt->rn_ybro;
 776 #endif
 777         t = tt->rn_parent;
 778         dupedkey = saved_tt->rn_dupedkey;
 779         if (dupedkey != NULL) {
 780                 /*
 781                  * at this point, tt is the deletion target and saved_tt
 782                  * is the head of the dupekey chain
 783                  */
 784                 if (tt == saved_tt) {
 785                         /* remove from head of chain */
 786                         x = dupedkey; x->rn_parent = t;
 787                         if (t->rn_left == tt)
 788                                 t->rn_left = x;
 789                         else
 790                                 t->rn_right = x;
 791                 } else {
 792                         /* find node in front of tt on the chain */
 793                         for (x = p = saved_tt; p && p->rn_dupedkey != tt;)
 794                                 p = p->rn_dupedkey;
 795                         if (p) {
 796                                 p->rn_dupedkey = tt->rn_dupedkey;
 797                                 if (tt->rn_dupedkey)            /* parent */
 798                                         tt->rn_dupedkey->rn_parent = p;
 799                                                                 /* parent */
 800                         } else log(LOG_ERR, "rn_delete: couldn't find us\n");
 801                 }
 802                 t = tt + 1;
 803                 if  (t->rn_flags & RNF_ACTIVE) {
 804 #ifndef RN_DEBUG
 805                         *++x = *t;
 806                         p = t->rn_parent;
 807 #else
 808                         b = t->rn_info;
 809                         *++x = *t;
 810                         t->rn_info = b;
 811                         p = t->rn_parent;
 812 #endif
 813                         if (p->rn_left == t)
 814                                 p->rn_left = x;
 815                         else
 816                                 p->rn_right = x;
 817                         x->rn_left->rn_parent = x;
 818                         x->rn_right->rn_parent = x;
 819                 }
 820                 goto out;
 821         }
 822         if (t->rn_left == tt)
 823                 x = t->rn_right;
 824         else
 825                 x = t->rn_left;
 826         p = t->rn_parent;
 827         if (p->rn_right == t)
 828                 p->rn_right = x;
 829         else
 830                 p->rn_left = x;
 831         x->rn_parent = p;
 832         /*
 833          * Demote routes attached to us.
 834          */
 835         if (t->rn_mklist != NULL) {
 836                 if (x->rn_bit >= 0) {
 837                         for (mp = &x->rn_mklist; (m = *mp);)
 838                                 mp = &m->rm_next;
 839                         *mp = t->rn_mklist;
 840                 } else {
 841                         /*
 842                          * If there are any (key, mask) pairs in a sibling
 843                          * duped-key chain, some subset will appear sorted
 844                          * in the same order attached to our mklist.
 845                          */
 846                         for (m = t->rn_mklist; m && x; x = x->rn_dupedkey)
 847                                 if (m == x->rn_mklist) {
 848                                         struct radix_mask *mm = m->rm_next;
 849
 850                                         x->rn_mklist = NULL;
 851                                         if (--(m->rm_refs) < 0)
 852                                                 MKFree(&rn_mkfreelist, m);
 853                                         m = mm;
 854                                 }
 855                         if (m)
 856                                 log(LOG_ERR,
 857                                     "rn_delete: Orphaned Mask %p at %p\n",
 858                                     (void *)m, (void *)x);
 859                 }
 860         }
 861         /*
 862          * We may be holding an active internal node in the tree.
 863          */
 864         x = tt + 1;
 865         if (t != x) {
 866 #ifndef RN_DEBUG
 867                 *t = *x;
 868 #else
 869                 b = t->rn_info;
 870                 *t = *x;
 871                 t->rn_info = b;
 872 #endif
 873                 t->rn_left->rn_parent = t;
 874                 t->rn_right->rn_parent = t;
 875                 p = x->rn_parent;
 876                 if (p->rn_left == x)
 877                         p->rn_left = t;
 878                 else
 879                         p->rn_right = t;
 880         }
 881 out:
 882         tt->rn_flags &= ~RNF_ACTIVE;
 883         tt[1].rn_flags &= ~RNF_ACTIVE;
 884         return (tt);
 885 }
 886
 887 /*
 888  * This is the same as rn_walktree() except for the parameters and the
 889  * exit.
 890  */
 891 static int
 892 rn_walktree_from(struct radix_node_head *h, char *xa, char *xm,
 893                  walktree_f_t *f, void *w)
 894 {
 895         struct radix_node *base, *next;
 896         struct radix_node *rn, *last = NULL /* shut up gcc */;
 897         boolean_t stopping = FALSE;
 898         int lastb, error;
 899
 900         /*
 901          * rn_search_m is sort-of-open-coded here.
 902          */
 903         /* kprintf("about to search\n"); */
 904         for (rn = h->rnh_treetop; rn->rn_bit >= 0; ) {
 905                 last = rn;
 906                 /* kprintf("rn_bit %d, rn_bmask %x, xm[rn_offset] %x\n",
 907                        rn->rn_bit, rn->rn_bmask, xm[rn->rn_offset]); */
 908                 if (!(rn->rn_bmask & xm[rn->rn_offset])) {
 909                         break;
 910                 }
 911                 if (rn->rn_bmask & xa[rn->rn_offset]) {
 912                         rn = rn->rn_right;
 913                 } else {
 914                         rn = rn->rn_left;
 915                 }
 916         }
 917         /* kprintf("done searching\n"); */
 918
 919         /*
 920          * Two cases: either we stepped off the end of our mask,
 921          * in which case last == rn, or we reached a leaf, in which
 922          * case we want to start from the last node we looked at.
 923          * Either way, last is the node we want to start from.
 924          */
 925         rn = last;
 926         lastb = rn->rn_bit;
 927
 928         /* kprintf("rn %p, lastb %d\n", rn, lastb);*/
 929
 930         /*
 931          * This gets complicated because we may delete the node
 932          * while applying the function f to it, so we need to calculate
 933          * the successor node in advance.
 934          */
 935         while (rn->rn_bit >= 0)
 936                 rn = rn->rn_left;
 937
 938         while (!stopping) {
 939                 /* kprintf("node %p (%d)\n", rn, rn->rn_bit); */
 940                 base = rn;
 941                 /* If at right child go back up, otherwise, go right */
 942                 while (rn->rn_parent->rn_right == rn &&
 943                     !(rn->rn_flags & RNF_ROOT)) {
 944                         rn = rn->rn_parent;
 945
 946                         /* if went up beyond last, stop */
 947                         if (rn->rn_bit < lastb) {
 948                                 stopping = TRUE;
 949                                 /* kprintf("up too far\n"); */
 950                         }
 951                 }
 952
 953                 /* Find the next *leaf* since next node might vanish, too */
 954                 for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;)
 955                         rn = rn->rn_left;
 956                 next = rn;
 957                 /* Process leaves */
 958                 while ((rn = base) != NULL) {
 959                         base = rn->rn_dupedkey;
 960                         /* kprintf("leaf %p\n", rn); */
 961                         if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w)))
 962                                 return (error);
 963                 }
 964                 rn = next;
 965
 966                 if (rn->rn_flags & RNF_ROOT) {
 967                         /* kprintf("root, stopping"); */
 968                         stopping = TRUE;
 969                 }
 970
 971         }
 972         return 0;
 973 }
 974
 975 static int
 976 rn_walktree(struct radix_node_head *h, walktree_f_t *f, void *w)
 977 {
 978         struct radix_node *base, *next;
 979         struct radix_node *rn = h->rnh_treetop;
 980         int error;
 981
 982         /*
 983          * This gets complicated because we may delete the node
 984          * while applying the function f to it, so we need to calculate
 985          * the successor node in advance.
 986          */
 987         /* First time through node, go left */
 988         while (rn->rn_bit >= 0)
 989                 rn = rn->rn_left;
 990         for (;;) {
 991                 base = rn;
 992                 /* If at right child go back up, otherwise, go right */
 993                 while (rn->rn_parent->rn_right == rn &&
 994                     !(rn->rn_flags & RNF_ROOT))
 995                         rn = rn->rn_parent;
 996                 /* Find the next *leaf* since next node might vanish, too */
 997                 for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;)
 998                         rn = rn->rn_left;
 999                 next = rn;
1000                 /* Process leaves */
1001                 while ((rn = base)) {
1002                         base = rn->rn_dupedkey;
1003                         if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w)))
1004                                 return (error);
1005                 }
1006                 rn = next;
1007                 if (rn->rn_flags & RNF_ROOT)
1008                         return (0);
1009         }
1010         /* NOTREACHED */
1011 }
1012
1013 int
1014 rn_inithead(void **head, int off)
1015 {
1016         struct radix_node_head *rnh;
1017         struct radix_node *root, *left, *right;
1018
1019         if (*head != NULL)      /* already initialized */
1020                 return (1);
1021
1022         R_Malloc(rnh, struct radix_node_head *, sizeof *rnh);
1023         if (rnh == NULL)
1024                 return (0);
1025         bzero(rnh, sizeof *rnh);
1026         *head = rnh;
1027
1028         root = rn_newpair(rn_zeros, off, rnh->rnh_nodes);
1029         right = &rnh->rnh_nodes[2];
1030         root->rn_parent = root;
1031         root->rn_flags = RNF_ROOT | RNF_ACTIVE;
1032         root->rn_right = right;
1033
1034         left = root->rn_left;
1035         left->rn_bit = -1 - off;
1036         left->rn_flags = RNF_ROOT | RNF_ACTIVE;
1037
1038         *right = *left;
1039         right->rn_key = rn_ones;
1040
1041         rnh->rnh_treetop = root;
1042
1043         rnh->rnh_addaddr = rn_addroute;
1044         rnh->rnh_deladdr = rn_delete;
1045         rnh->rnh_matchaddr = rn_match;
1046         rnh->rnh_lookup = rn_lookup;
1047         rnh->rnh_walktree = rn_walktree;
1048         rnh->rnh_walktree_from = rn_walktree_from;
1049
1050         return (1);
1051 }
1052
1053 void
1054 rn_init(void)
1055 {
1056         char *cp, *cplim;
1057 #ifdef _KERNEL
1058         struct domain *dom;
1059
1060         SLIST_FOREACH(dom, &domains, dom_next)
1061                 if (dom->dom_maxrtkey > max_keylen)
1062                         max_keylen = dom->dom_maxrtkey;
1063 #endif
1064         if (max_keylen == 0) {
1065                 log(LOG_ERR,
1066                     "rn_init: radix functions require max_keylen be set\n");
1067                 return;
1068         }
1069         R_Malloc(rn_zeros, char *, 2 * max_keylen);
1070         if (rn_zeros == NULL)
1071                 panic("rn_init");
1072         bzero(rn_zeros, 2 * max_keylen);
1073         rn_ones = cp = rn_zeros + max_keylen;
1074         cplim = rn_ones + max_keylen;
1075         while (cp < cplim)
1076                 *cp++ = -1;
1077         if (rn_inithead((void **)&mask_rnhead, 0) == 0)
1078                 panic("rn_init 2");
1079 }