sbin/routed/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 acknowledgment:
  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  *
  35  * $FreeBSD: src/sbin/routed/radix.c,v 1.5 1999/09/05 17:49:11 peter Exp $
  36  */
  37
  38 /*
  39  * Routines to build and maintain radix trees for routing lookups.
  40  */
  41
  42 #include "defs.h"
  43
  44 #if !defined(sgi) && !defined(__NetBSD__)
  45 static char sccsid[] __attribute__((unused)) = "@(#)rdisc.c     8.1 (Berkeley) x/y/95";
  46 #elif defined(__NetBSD__)
  47 __RCSID("$NetBSD$");
  48 #endif
  49
  50 #define log(x, msg) syslog(x, msg)
  51 #define panic(s) {log(LOG_ERR,s); exit(1);}
  52 #define min(a,b) (((a)<(b))?(a):(b))
  53
  54 int     max_keylen;
  55 struct radix_mask *rn_mkfreelist;
  56 struct radix_node_head *mask_rnhead;
  57 static char *addmask_key;
  58 static char normal_chars[] = {0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1};
  59 static char *rn_zeros, *rn_ones;
  60
  61 #define rn_masktop (mask_rnhead->rnh_treetop)
  62 #undef Bcmp
  63 #define Bcmp(a, b, l) (l == 0 ? 0 \
  64                        : memcmp((caddr_t)(a), (caddr_t)(b), (size_t)l))
  65
  66 static int rn_satisfies_leaf(char *, struct radix_node *, int);
  67
  68 /*
  69  * The data structure for the keys is a radix tree with one way
  70  * branching removed.  The index rn_b at an internal node n represents a bit
  71  * position to be tested.  The tree is arranged so that all descendants
  72  * of a node n have keys whose bits all agree up to position rn_b - 1.
  73  * (We say the index of n is rn_b.)
  74  *
  75  * There is at least one descendant which has a one bit at position rn_b,
  76  * and at least one with a zero there.
  77  *
  78  * A route is determined by a pair of key and mask.  We require that the
  79  * bit-wise logical and of the key and mask to be the key.
  80  * We define the index of a route to associated with the mask to be
  81  * the first bit number in the mask where 0 occurs (with bit number 0
  82  * representing the highest order bit).
  83  *
  84  * We say a mask is normal if every bit is 0, past the index of the mask.
  85  * If a node n has a descendant (k, m) with index(m) == index(n) == rn_b,
  86  * and m is a normal mask, then the route applies to every descendant of n.
  87  * If the index(m) < rn_b, this implies the trailing last few bits of k
  88  * before bit b are all 0, (and hence consequently true of every descendant
  89  * of n), so the route applies to all descendants of the node as well.
  90  *
  91  * Similar logic shows that a non-normal mask m such that
  92  * index(m) <= index(n) could potentially apply to many children of n.
  93  * Thus, for each non-host route, we attach its mask to a list at an internal
  94  * node as high in the tree as we can go.
  95  *
  96  * The present version of the code makes use of normal routes in short-
  97  * circuiting an explict mask and compare operation when testing whether
  98  * a key satisfies a normal route, and also in remembering the unique leaf
  99  * that governs a subtree.
 100  */
 101
 102 struct radix_node *
 103 rn_search(void *v_arg,
 104           struct radix_node *head)
 105 {
 106         struct radix_node *x;
 107         caddr_t v;
 108
 109         for (x = head, v = v_arg; x->rn_b >= 0;) {
 110                 if (x->rn_bmask & v[x->rn_off])
 111                         x = x->rn_r;
 112                 else
 113                         x = x->rn_l;
 114         }
 115         return (x);
 116 }
 117
 118 struct radix_node *
 119 rn_search_m(void *v_arg,
 120             struct radix_node *head,
 121             void *m_arg)
 122 {
 123         struct radix_node *x;
 124         caddr_t v = v_arg, m = m_arg;
 125
 126         for (x = head; x->rn_b >= 0;) {
 127                 if ((x->rn_bmask & m[x->rn_off]) &&
 128                     (x->rn_bmask & v[x->rn_off]))
 129                         x = x->rn_r;
 130                 else
 131                         x = x->rn_l;
 132         }
 133         return x;
 134 }
 135
 136 int
 137 rn_refines(void* m_arg, void *n_arg)
 138 {
 139         caddr_t m = m_arg, n = n_arg;
 140         caddr_t lim, lim2 = lim = n + *(u_char *)n;
 141         int longer = (*(u_char *)n++) - (int)(*(u_char *)m++);
 142         int masks_are_equal = 1;
 143
 144         if (longer > 0)
 145                 lim -= longer;
 146         while (n < lim) {
 147                 if (*n & ~(*m))
 148                         return 0;
 149                 if (*n++ != *m++)
 150                         masks_are_equal = 0;
 151         }
 152         while (n < lim2)
 153                 if (*n++)
 154                         return 0;
 155         if (masks_are_equal && (longer < 0))
 156                 for (lim2 = m - longer; m < lim2; )
 157                         if (*m++)
 158                                 return 1;
 159         return (!masks_are_equal);
 160 }
 161
 162 struct radix_node *
 163 rn_lookup(void *v_arg, void *m_arg, struct radix_node_head *head)
 164 {
 165         struct radix_node *x;
 166         caddr_t netmask = 0;
 167
 168         if (m_arg) {
 169                 if ((x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_off)) == NULL)
 170                         return (0);
 171                 netmask = x->rn_key;
 172         }
 173         x = rn_match(v_arg, head);
 174         if (x && netmask) {
 175                 while (x && x->rn_mask != netmask)
 176                         x = x->rn_dupedkey;
 177         }
 178         return x;
 179 }
 180
 181 static int
 182 rn_satisfies_leaf(char *trial,
 183                   struct radix_node *leaf,
 184                   int skip)
 185 {
 186         char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask;
 187         char *cplim;
 188         int length = min(*(u_char *)cp, *(u_char *)cp2);
 189
 190         if (cp3 == NULL)
 191                 cp3 = rn_ones;
 192         else
 193                 length = min(length, *(u_char *)cp3);
 194         cplim = cp + length; cp3 += skip; cp2 += skip;
 195         for (cp += skip; cp < cplim; cp++, cp2++, cp3++)
 196                 if ((*cp ^ *cp2) & *cp3)
 197                         return 0;
 198         return 1;
 199 }
 200
 201 struct radix_node *
 202 rn_match(void *v_arg,
 203          struct radix_node_head *head)
 204 {
 205         caddr_t v = v_arg;
 206         struct radix_node *t = head->rnh_treetop, *x;
 207         caddr_t cp = v, cp2;
 208         caddr_t cplim;
 209         struct radix_node *saved_t, *top = t;
 210         int off = t->rn_off, vlen = *(u_char *)cp, matched_off;
 211         int test, b, rn_b;
 212
 213         /*
 214          * Open code rn_search(v, top) to avoid overhead of extra
 215          * subroutine call.
 216          */
 217         for (; t->rn_b >= 0; ) {
 218                 if (t->rn_bmask & cp[t->rn_off])
 219                         t = t->rn_r;
 220                 else
 221                         t = t->rn_l;
 222         }
 223         /*
 224          * See if we match exactly as a host destination
 225          * or at least learn how many bits match, for normal mask finesse.
 226          *
 227          * It doesn't hurt us to limit how many bytes to check
 228          * to the length of the mask, since if it matches we had a genuine
 229          * match and the leaf we have is the most specific one anyway;
 230          * if it didn't match with a shorter length it would fail
 231          * with a long one.  This wins big for class B&C netmasks which
 232          * are probably the most common case...
 233          */
 234         if (t->rn_mask)
 235                 vlen = *(u_char *)t->rn_mask;
 236         cp += off; cp2 = t->rn_key + off; cplim = v + vlen;
 237         for (; cp < cplim; cp++, cp2++)
 238                 if (*cp != *cp2)
 239                         goto on1;
 240         /*
 241          * This extra grot is in case we are explicitly asked
 242          * to look up the default.  Ugh!
 243          * Or 255.255.255.255
 244          *
 245          * In this case, we have a complete match of the key.  Unless
 246          * the node is one of the roots, we are finished.
 247          * If it is the zeros root, then take what we have, prefering
 248          * any real data.
 249          * If it is the ones root, then pretend the target key was followed
 250          * by a byte of zeros.
 251          */
 252         if (!(t->rn_flags & RNF_ROOT))
 253                 return t;               /* not a root */
 254         if (t->rn_dupedkey) {
 255                 t = t->rn_dupedkey;
 256                 return t;               /* have some real data */
 257         }
 258         if (*(cp-1) == 0)
 259                 return t;               /* not the ones root */
 260         b = 0;                          /* fake a zero after 255.255.255.255 */
 261         goto on2;
 262 on1:
 263         test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */
 264         for (b = 7; (test >>= 1) > 0;)
 265                 b--;
 266 on2:
 267         matched_off = cp - v;
 268         b += matched_off << 3;
 269         rn_b = -1 - b;
 270         /*
 271          * If there is a host route in a duped-key chain, it will be first.
 272          */
 273         if ((saved_t = t)->rn_mask == 0)
 274                 t = t->rn_dupedkey;
 275         for (; t; t = t->rn_dupedkey) {
 276                 /*
 277                  * Even if we don't match exactly as a host,
 278                  * we may match if the leaf we wound up at is
 279                  * a route to a net.
 280                  */
 281                 if (t->rn_flags & RNF_NORMAL) {
 282                         if (rn_b <= t->rn_b)
 283                                 return t;
 284                 } else if (rn_satisfies_leaf(v, t, matched_off)) {
 285                         return t;
 286                 }
 287         }
 288         t = saved_t;
 289         /* start searching up the tree */
 290         do {
 291                 struct radix_mask *m;
 292                 t = t->rn_p;
 293                 if ((m = t->rn_mklist)) {
 294                         /*
 295                          * If non-contiguous masks ever become important
 296                          * we can restore the masking and open coding of
 297                          * the search and satisfaction test and put the
 298                          * calculation of "off" back before the "do".
 299                          */
 300                         do {
 301                                 if (m->rm_flags & RNF_NORMAL) {
 302                                         if (rn_b <= m->rm_b)
 303                                                 return (m->rm_leaf);
 304                                 } else {
 305                                         off = min(t->rn_off, matched_off);
 306                                         x = rn_search_m(v, t, m->rm_mask);
 307                                         while (x && x->rn_mask != m->rm_mask)
 308                                                 x = x->rn_dupedkey;
 309                                         if (x && rn_satisfies_leaf(v, x, off))
 310                                                     return x;
 311                                 }
 312                         } while ((m = m->rm_mklist));
 313                 }
 314         } while (t != top);
 315         return 0;
 316 }
 317
 318 #ifdef RN_DEBUG
 319 int     rn_nodenum;
 320 struct  radix_node *rn_clist;
 321 int     rn_saveinfo;
 322 int     rn_debug =  1;
 323 #endif
 324
 325 struct radix_node *
 326 rn_newpair(void *v, int b, struct radix_node nodes[2])
 327 {
 328         struct radix_node *tt = nodes, *t = tt + 1;
 329         t->rn_b = b; t->rn_bmask = 0x80 >> (b & 7);
 330         t->rn_l = tt; t->rn_off = b >> 3;
 331         tt->rn_b = -1; tt->rn_key = (caddr_t)v; tt->rn_p = t;
 332         tt->rn_flags = t->rn_flags = RNF_ACTIVE;
 333 #ifdef RN_DEBUG
 334         tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
 335         tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt;
 336 #endif
 337         return t;
 338 }
 339
 340 struct radix_node *
 341 rn_insert(void* v_arg,
 342           struct radix_node_head *head,
 343           int *dupentry,
 344           struct radix_node nodes[2])
 345 {
 346         caddr_t v = v_arg;
 347         struct radix_node *top = head->rnh_treetop;
 348         int head_off = top->rn_off, vlen = (int)*((u_char *)v);
 349         struct radix_node *t = rn_search(v_arg, top);
 350         caddr_t cp = v + head_off;
 351         int b;
 352         struct radix_node *tt;
 353
 354         /*
 355          * Find first bit at which v and t->rn_key differ
 356          */
 357     {
 358                 caddr_t cp2 = t->rn_key + head_off;
 359                 int cmp_res;
 360         caddr_t cplim = v + vlen;
 361
 362         while (cp < cplim)
 363                 if (*cp2++ != *cp++)
 364                         goto on1;
 365         /* handle adding 255.255.255.255 */
 366         if (!(t->rn_flags & RNF_ROOT) || *(cp2-1) == 0) {
 367                 *dupentry = 1;
 368                 return t;
 369         }
 370 on1:
 371         *dupentry = 0;
 372         cmp_res = (cp[-1] ^ cp2[-1]) & 0xff;
 373         for (b = (cp - v) << 3; cmp_res; b--)
 374                 cmp_res >>= 1;
 375     }
 376     {
 377             struct radix_node *p, *x = top;
 378         cp = v;
 379         do {
 380                 p = x;
 381                 if (cp[x->rn_off] & x->rn_bmask)
 382                         x = x->rn_r;
 383                 else x = x->rn_l;
 384         } while ((unsigned)b > (unsigned)x->rn_b);
 385 #ifdef RN_DEBUG
 386         if (rn_debug)
 387                 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p);
 388 #endif
 389         t = rn_newpair(v_arg, b, nodes); tt = t->rn_l;
 390         if ((cp[p->rn_off] & p->rn_bmask) == 0)
 391                 p->rn_l = t;
 392         else
 393                 p->rn_r = t;
 394         x->rn_p = t; t->rn_p = p; /* frees x, p as temp vars below */
 395         if ((cp[t->rn_off] & t->rn_bmask) == 0) {
 396                 t->rn_r = x;
 397         } else {
 398                 t->rn_r = tt; t->rn_l = x;
 399         }
 400 #ifdef RN_DEBUG
 401         if (rn_debug)
 402                 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p);
 403 #endif
 404     }
 405         return (tt);
 406 }
 407
 408 struct radix_node *
 409 rn_addmask(void *n_arg, int search, int skip)
 410 {
 411         caddr_t netmask = (caddr_t)n_arg;
 412         struct radix_node *x;
 413         caddr_t cp, cplim;
 414         int b = 0, mlen, j;
 415         int maskduplicated, m0, isnormal;
 416         struct radix_node *saved_x;
 417         static int last_zeroed = 0;
 418
 419         if ((mlen = *(u_char *)netmask) > max_keylen)
 420                 mlen = max_keylen;
 421         if (skip == 0)
 422                 skip = 1;
 423         if (mlen <= skip)
 424                 return (mask_rnhead->rnh_nodes);
 425         if (skip > 1)
 426                 Bcopy(rn_ones + 1, addmask_key + 1, skip - 1);
 427         if ((m0 = mlen) > skip)
 428                 Bcopy(netmask + skip, addmask_key + skip, mlen - skip);
 429         /*
 430          * Trim trailing zeroes.
 431          */
 432         for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;)
 433                 cp--;
 434         mlen = cp - addmask_key;
 435         if (mlen <= skip) {
 436                 if (m0 >= last_zeroed)
 437                         last_zeroed = mlen;
 438                 return (mask_rnhead->rnh_nodes);
 439         }
 440         if (m0 < last_zeroed)
 441                 Bzero(addmask_key + m0, last_zeroed - m0);
 442         *addmask_key = last_zeroed = mlen;
 443         x = rn_search(addmask_key, rn_masktop);
 444         if (Bcmp(addmask_key, x->rn_key, mlen) != 0)
 445                 x = NULL;
 446         if (x || search)
 447                 return (x);
 448         x = (struct radix_node *)rtmalloc(max_keylen + 2*sizeof(*x),
 449                                           "rn_addmask");
 450         saved_x = x;
 451         Bzero(x, max_keylen + 2 * sizeof (*x));
 452         netmask = cp = (caddr_t)(x + 2);
 453         Bcopy(addmask_key, cp, mlen);
 454         x = rn_insert(cp, mask_rnhead, &maskduplicated, x);
 455         if (maskduplicated) {
 456                 log(LOG_ERR, "rn_addmask: mask impossibly already in tree");
 457                 Free(saved_x);
 458                 return (x);
 459         }
 460         /*
 461          * Calculate index of mask, and check for normalcy.
 462          */
 463         cplim = netmask + mlen; isnormal = 1;
 464         for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;)
 465                 cp++;
 466         if (cp != cplim) {
 467                 for (j = 0x80; (j & *cp) != 0; j >>= 1)
 468                         b++;
 469                 if (*cp != normal_chars[b] || cp != (cplim - 1))
 470                         isnormal = 0;
 471         }
 472         b += (cp - netmask) << 3;
 473         x->rn_b = -1 - b;
 474         if (isnormal)
 475                 x->rn_flags |= RNF_NORMAL;
 476         return (x);
 477 }
 478
 479 static int      /* XXX: arbitrary ordering for non-contiguous masks */
 480 rn_lexobetter(void *m_arg, void *n_arg)
 481 {
 482         u_char *mp = m_arg, *np = n_arg, *lim;
 483
 484         if (*mp > *np)
 485                 return 1;  /* not really, but need to check longer one first */
 486         if (*mp == *np)
 487                 for (lim = mp + *mp; mp < lim;)
 488                         if (*mp++ > *np++)
 489                                 return 1;
 490         return 0;
 491 }
 492
 493 static struct radix_mask *
 494 rn_new_radix_mask(struct radix_node *tt,
 495                   struct radix_mask *next)
 496 {
 497         struct radix_mask *m;
 498
 499         MKGet(m);
 500         if (m == NULL) {
 501                 log(LOG_ERR, "Mask for route not entered\n");
 502                 return (0);
 503         }
 504         Bzero(m, sizeof *m);
 505         m->rm_b = tt->rn_b;
 506         m->rm_flags = tt->rn_flags;
 507         if (tt->rn_flags & RNF_NORMAL)
 508                 m->rm_leaf = tt;
 509         else
 510                 m->rm_mask = tt->rn_mask;
 511         m->rm_mklist = next;
 512         tt->rn_mklist = m;
 513         return m;
 514 }
 515
 516 struct radix_node *
 517 rn_addroute(void *v_arg,
 518             void *n_arg,
 519             struct radix_node_head *head,
 520             struct radix_node treenodes[2])
 521 {
 522         caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg;
 523         struct radix_node *t, *x = NULL, *tt;
 524         struct radix_node *saved_tt, *top = head->rnh_treetop;
 525         short b = 0, b_leaf = 0;
 526         int keyduplicated;
 527         caddr_t mmask;
 528         struct radix_mask *m, **mp;
 529
 530         /*
 531          * In dealing with non-contiguous masks, there may be
 532          * many different routes which have the same mask.
 533          * We will find it useful to have a unique pointer to
 534          * the mask to speed avoiding duplicate references at
 535          * nodes and possibly save time in calculating indices.
 536          */
 537         if (netmask)  {
 538                 if ((x = rn_addmask(netmask, 0, top->rn_off)) == NULL)
 539                         return (0);
 540                 b_leaf = x->rn_b;
 541                 b = -1 - x->rn_b;
 542                 netmask = x->rn_key;
 543         }
 544         /*
 545          * Deal with duplicated keys: attach node to previous instance
 546          */
 547         saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes);
 548         if (keyduplicated) {
 549                 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) {
 550                         if (tt->rn_mask == netmask)
 551                                 return (0);
 552                         if (netmask == 0 ||
 553                             (tt->rn_mask &&
 554                              ((b_leaf < tt->rn_b) || /* index(netmask) > node */
 555                                rn_refines(netmask, tt->rn_mask) ||
 556                                rn_lexobetter(netmask, tt->rn_mask))))
 557                                 break;
 558                 }
 559                 /*
 560                  * If the mask is not duplicated, we wouldn't
 561                  * find it among possible duplicate key entries
 562                  * anyway, so the above test doesn't hurt.
 563                  *
 564                  * We sort the masks for a duplicated key the same way as
 565                  * in a masklist -- most specific to least specific.
 566                  * This may require the unfortunate nuisance of relocating
 567                  * the head of the list.
 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                         if (x->rn_l == t) x->rn_l = tt; else x->rn_r = tt;
 576                         saved_tt = tt; x = xx;
 577                 } else {
 578                         (tt = treenodes)->rn_dupedkey = t->rn_dupedkey;
 579                         t->rn_dupedkey = tt;
 580                 }
 581 #ifdef RN_DEBUG
 582                 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
 583                 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt;
 584 #endif
 585                 tt->rn_key = (caddr_t) v;
 586                 tt->rn_b = -1;
 587                 tt->rn_flags = RNF_ACTIVE;
 588         }
 589         /*
 590          * Put mask in tree.
 591          */
 592         if (netmask) {
 593                 tt->rn_mask = netmask;
 594                 tt->rn_b = x->rn_b;
 595                 tt->rn_flags |= x->rn_flags & RNF_NORMAL;
 596         }
 597         t = saved_tt->rn_p;
 598         if (keyduplicated)
 599                 goto on2;
 600         b_leaf = -1 - t->rn_b;
 601         if (t->rn_r == saved_tt) x = t->rn_l; else x = t->rn_r;
 602         /* Promote general routes from below */
 603         if (x->rn_b < 0) {
 604             for (mp = &t->rn_mklist; x; x = x->rn_dupedkey)
 605                 if (x->rn_mask && (x->rn_b >= b_leaf) && x->rn_mklist == 0) {
 606                         if ((*mp = m = rn_new_radix_mask(x, 0)))
 607                                 mp = &m->rm_mklist;
 608                 }
 609         } else if (x->rn_mklist) {
 610                 /*
 611                  * Skip over masks whose index is > that of new node
 612                  */
 613                 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
 614                         if (m->rm_b >= b_leaf)
 615                                 break;
 616                 t->rn_mklist = m; *mp = NULL;
 617         }
 618 on2:
 619         /* Add new route to highest possible ancestor's list */
 620         if ((netmask == 0) || (b > t->rn_b ))
 621                 return tt; /* can't lift at all */
 622         b_leaf = tt->rn_b;
 623         do {
 624                 x = t;
 625                 t = t->rn_p;
 626         } while (b <= t->rn_b && x != top);
 627         /*
 628          * Search through routes associated with node to
 629          * insert new route according to index.
 630          * Need same criteria as when sorting dupedkeys to avoid
 631          * double loop on deletion.
 632          */
 633         for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) {
 634                 if (m->rm_b < b_leaf)
 635                         continue;
 636                 if (m->rm_b > b_leaf)
 637                         break;
 638                 if (m->rm_flags & RNF_NORMAL) {
 639                         mmask = m->rm_leaf->rn_mask;
 640                         if (tt->rn_flags & RNF_NORMAL) {
 641                                 log(LOG_ERR,
 642                                    "Non-unique normal route, mask not entered");
 643                                 return tt;
 644                         }
 645                 } else
 646                         mmask = m->rm_mask;
 647                 if (mmask == netmask) {
 648                         m->rm_refs++;
 649                         tt->rn_mklist = m;
 650                         return tt;
 651                 }
 652                 if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask))
 653                         break;
 654         }
 655         *mp = rn_new_radix_mask(tt, *mp);
 656         return tt;
 657 }
 658
 659 struct radix_node *
 660 rn_delete(void *v_arg,
 661           void *netmask_arg,
 662           struct radix_node_head *head)
 663 {
 664         struct radix_node *t, *p, *x, *tt;
 665         struct radix_mask *m, *saved_m, **mp;
 666         struct radix_node *dupedkey, *saved_tt, *top;
 667         caddr_t v, netmask;
 668         int b, head_off, vlen;
 669
 670         v = v_arg;
 671         netmask = netmask_arg;
 672         x = head->rnh_treetop;
 673         tt = rn_search(v, x);
 674         head_off = x->rn_off;
 675         vlen =  *(u_char *)v;
 676         saved_tt = tt;
 677         top = x;
 678         if (tt == NULL ||
 679             Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off))
 680                 return (0);
 681         /*
 682          * Delete our route from mask lists.
 683          */
 684         if (netmask) {
 685                 if ((x = rn_addmask(netmask, 1, head_off)) == NULL)
 686                         return (0);
 687                 netmask = x->rn_key;
 688                 while (tt->rn_mask != netmask)
 689                         if ((tt = tt->rn_dupedkey) == NULL)
 690                                 return (0);
 691         }
 692         if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == NULL)
 693                 goto on1;
 694         if (tt->rn_flags & RNF_NORMAL) {
 695                 if (m->rm_leaf != tt || m->rm_refs > 0) {
 696                         log(LOG_ERR, "rn_delete: inconsistent annotation\n");
 697                         return 0;  /* dangling ref could cause disaster */
 698                 }
 699         } else {
 700                 if (m->rm_mask != tt->rn_mask) {
 701                         log(LOG_ERR, "rn_delete: inconsistent annotation\n");
 702                         goto on1;
 703                 }
 704                 if (--m->rm_refs >= 0)
 705                         goto on1;
 706         }
 707         b = -1 - tt->rn_b;
 708         t = saved_tt->rn_p;
 709         if (b > t->rn_b)
 710                 goto on1; /* Wasn't lifted at all */
 711         do {
 712                 x = t;
 713                 t = t->rn_p;
 714         } while (b <= t->rn_b && x != top);
 715         for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
 716                 if (m == saved_m) {
 717                         *mp = m->rm_mklist;
 718                         MKFree(m);
 719                         break;
 720                 }
 721         if (m == NULL) {
 722                 log(LOG_ERR, "rn_delete: couldn't find our annotation\n");
 723                 if (tt->rn_flags & RNF_NORMAL)
 724                         return (0); /* Dangling ref to us */
 725         }
 726 on1:
 727         /*
 728          * Eliminate us from tree
 729          */
 730         if (tt->rn_flags & RNF_ROOT)
 731                 return (0);
 732 #ifdef RN_DEBUG
 733         /* Get us out of the creation list */
 734         for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {}
 735         if (t) t->rn_ybro = tt->rn_ybro;
 736 #endif
 737         t = tt->rn_p;
 738         if ((dupedkey = saved_tt->rn_dupedkey)) {
 739                 if (tt == saved_tt) {
 740                         x = dupedkey; x->rn_p = t;
 741                         if (t->rn_l == tt) t->rn_l = x; else t->rn_r = x;
 742                 } else {
 743                         for (x = p = saved_tt; p && p->rn_dupedkey != tt;)
 744                                 p = p->rn_dupedkey;
 745                         if (p) p->rn_dupedkey = tt->rn_dupedkey;
 746                         else log(LOG_ERR, "rn_delete: couldn't find us\n");
 747                 }
 748                 t = tt + 1;
 749                 if  (t->rn_flags & RNF_ACTIVE) {
 750 #ifndef RN_DEBUG
 751                         *++x = *t; p = t->rn_p;
 752 #else
 753                         b = t->rn_info; *++x = *t; t->rn_info = b; p = t->rn_p;
 754 #endif
 755                         if (p->rn_l == t) p->rn_l = x; else p->rn_r = x;
 756                         x->rn_l->rn_p = x; x->rn_r->rn_p = x;
 757                 }
 758                 goto out;
 759         }
 760         if (t->rn_l == tt) x = t->rn_r; else x = t->rn_l;
 761         p = t->rn_p;
 762         if (p->rn_r == t) p->rn_r = x; else p->rn_l = x;
 763         x->rn_p = p;
 764         /*
 765          * Demote routes attached to us.
 766          */
 767         if (t->rn_mklist) {
 768                 if (x->rn_b >= 0) {
 769                         for (mp = &x->rn_mklist; (m = *mp);)
 770                                 mp = &m->rm_mklist;
 771                         *mp = t->rn_mklist;
 772                 } else {
 773                         /* If there are any key,mask pairs in a sibling
 774                            duped-key chain, some subset will appear sorted
 775                            in the same order attached to our mklist */
 776                         for (m = t->rn_mklist; m && x; x = x->rn_dupedkey)
 777                                 if (m == x->rn_mklist) {
 778                                         struct radix_mask *mm = m->rm_mklist;
 779                                         x->rn_mklist = 0;
 780                                         if (--(m->rm_refs) < 0)
 781                                                 MKFree(m);
 782                                         m = mm;
 783                                 }
 784                         if (m)
 785                                 syslog(LOG_ERR, "%s 0x%lx at 0x%lx\n",
 786                                        "rn_delete: Orphaned Mask",
 787                                        (unsigned long)m,
 788                                        (unsigned long)x);
 789                 }
 790         }
 791         /*
 792          * We may be holding an active internal node in the tree.
 793          */
 794         x = tt + 1;
 795         if (t != x) {
 796 #ifndef RN_DEBUG
 797                 *t = *x;
 798 #else
 799                 b = t->rn_info; *t = *x; t->rn_info = b;
 800 #endif
 801                 t->rn_l->rn_p = t; t->rn_r->rn_p = t;
 802                 p = x->rn_p;
 803                 if (p->rn_l == x) p->rn_l = t; else p->rn_r = t;
 804         }
 805 out:
 806         tt->rn_flags &= ~RNF_ACTIVE;
 807         tt[1].rn_flags &= ~RNF_ACTIVE;
 808         return (tt);
 809 }
 810
 811 int
 812 rn_walktree(struct radix_node_head *h,
 813             int (*f)(struct radix_node *, struct walkarg *),
 814             struct walkarg *w)
 815 {
 816         int error;
 817         struct radix_node *base, *next;
 818         struct radix_node *rn = h->rnh_treetop;
 819         /*
 820          * This gets complicated because we may delete the node
 821          * while applying the function f to it, so we need to calculate
 822          * the successor node in advance.
 823          */
 824         /* First time through node, go left */
 825         while (rn->rn_b >= 0)
 826                 rn = rn->rn_l;
 827         for (;;) {
 828                 base = rn;
 829                 /* If at right child go back up, otherwise, go right */
 830                 while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0)
 831                         rn = rn->rn_p;
 832                 /* Find the next *leaf* since next node might vanish, too */
 833                 for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;)
 834                         rn = rn->rn_l;
 835                 next = rn;
 836                 /* Process leaves */
 837                 while ((rn = base)) {
 838                         base = rn->rn_dupedkey;
 839                         if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w)))
 840                                 return (error);
 841                 }
 842                 rn = next;
 843                 if (rn->rn_flags & RNF_ROOT)
 844                         return (0);
 845         }
 846         /* NOTREACHED */
 847 }
 848
 849 int
 850 rn_inithead(struct radix_node_head **head, int off)
 851 {
 852         struct radix_node_head *rnh;
 853         struct radix_node *t, *tt, *ttt;
 854         if (*head)
 855                 return (1);
 856         rnh = (struct radix_node_head *)rtmalloc(sizeof(*rnh), "rn_inithead");
 857         Bzero(rnh, sizeof (*rnh));
 858         *head = rnh;
 859         t = rn_newpair(rn_zeros, off, rnh->rnh_nodes);
 860         ttt = rnh->rnh_nodes + 2;
 861         t->rn_r = ttt;
 862         t->rn_p = t;
 863         tt = t->rn_l;
 864         tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE;
 865         tt->rn_b = -1 - off;
 866         *ttt = *tt;
 867         ttt->rn_key = rn_ones;
 868         rnh->rnh_addaddr = rn_addroute;
 869         rnh->rnh_deladdr = rn_delete;
 870         rnh->rnh_matchaddr = rn_match;
 871         rnh->rnh_lookup = rn_lookup;
 872         rnh->rnh_walktree = rn_walktree;
 873         rnh->rnh_treetop = t;
 874         return (1);
 875 }
 876
 877 void
 878 rn_init(void)
 879 {
 880         char *cp, *cplim;
 881         if (max_keylen == 0) {
 882                 printf("rn_init: radix functions require max_keylen be set\n");
 883                 return;
 884         }
 885         rn_zeros = (char *)rtmalloc(3 * max_keylen, "rn_init");
 886         Bzero(rn_zeros, 3 * max_keylen);
 887         rn_ones = cp = rn_zeros + max_keylen;
 888         addmask_key = cplim = rn_ones + max_keylen;
 889         while (cp < cplim)
 890                 *cp++ = -1;
 891         if (rn_inithead(&mask_rnhead, 0) == 0)
 892                 panic("rn_init 2");
 893 }
 894