The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/net/radix.c

Version: -  FREEBSD  -  FREEBSD-13-STABLE  -  FREEBSD-13-0  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  l41  -  OPENBSD  -  linux-2.6  -  MK84  -  PLAN9  -  xnu-8792 
SearchContext: -  none  -  3  -  10 

    1 /*      $NetBSD: radix.c,v 1.28 2005/02/26 22:45:09 perry Exp $ */
    2 
    3 /*
    4  * Copyright (c) 1988, 1989, 1993
    5  *      The Regents of the University of California.  All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  * 3. Neither the name of the University nor the names of its contributors
   16  *    may be used to endorse or promote products derived from this software
   17  *    without specific prior written permission.
   18  *
   19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   29  * SUCH DAMAGE.
   30  *
   31  *      @(#)radix.c     8.6 (Berkeley) 10/17/95
   32  */
   33 
   34 /*
   35  * Routines to build and maintain radix trees for routing lookups.
   36  */
   37 
   38 #include <sys/cdefs.h>
   39 __KERNEL_RCSID(0, "$NetBSD: radix.c,v 1.28 2005/02/26 22:45:09 perry Exp $");
   40 
   41 #ifndef _NET_RADIX_H_
   42 #include <sys/param.h>
   43 #ifdef  _KERNEL
   44 #include "opt_inet.h"
   45 
   46 #include <sys/systm.h>
   47 #include <sys/malloc.h>
   48 #define M_DONTWAIT M_NOWAIT
   49 #include <sys/domain.h>
   50 #include <netinet/ip_encap.h>
   51 #else
   52 #include <stdlib.h>
   53 #endif
   54 #include <sys/syslog.h>
   55 #include <net/radix.h>
   56 #endif
   57 
   58 int     max_keylen;
   59 struct radix_mask *rn_mkfreelist;
   60 struct radix_node_head *mask_rnhead;
   61 static char *addmask_key;
   62 static const char normal_chars[] =
   63     {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(const char *, struct radix_node *, int);
   71 static int rn_lexobetter(const void *, const 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 explict mask and compare operation when testing whether
  105  * a key satisfies a normal route, and also in remembering the unique leaf
  106  * that governs a subtree.
  107  */
  108 
  109 struct radix_node *
  110 rn_search(
  111         const void *v_arg,
  112         struct radix_node *head)
  113 {
  114         const u_char * const v = v_arg;
  115         struct radix_node *x;
  116 
  117         for (x = head; x->rn_b >= 0;) {
  118                 if (x->rn_bmask & v[x->rn_off])
  119                         x = x->rn_r;
  120                 else
  121                         x = x->rn_l;
  122         }
  123         return (x);
  124 }
  125 
  126 struct radix_node *
  127 rn_search_m(
  128         const void *v_arg,
  129         struct radix_node *head,
  130         const void *m_arg)
  131 {
  132         struct radix_node *x;
  133         const u_char * const v = v_arg;
  134         const u_char * const m = m_arg;
  135 
  136         for (x = head; x->rn_b >= 0;) {
  137                 if ((x->rn_bmask & m[x->rn_off]) &&
  138                     (x->rn_bmask & v[x->rn_off]))
  139                         x = x->rn_r;
  140                 else
  141                         x = x->rn_l;
  142         }
  143         return x;
  144 }
  145 
  146 int
  147 rn_refines(
  148         const void *m_arg,
  149         const void *n_arg)
  150 {
  151         const char *m = m_arg;
  152         const char *n = n_arg;
  153         const char *lim = n + *(u_char *)n;
  154         const char *lim2 = lim;
  155         int longer = (*(u_char *)n++) - (int)(*(u_char *)m++);
  156         int masks_are_equal = 1;
  157 
  158         if (longer > 0)
  159                 lim -= longer;
  160         while (n < lim) {
  161                 if (*n & ~(*m))
  162                         return 0;
  163                 if (*n++ != *m++)
  164                         masks_are_equal = 0;
  165         }
  166         while (n < lim2)
  167                 if (*n++)
  168                         return 0;
  169         if (masks_are_equal && (longer < 0))
  170                 for (lim2 = m - longer; m < lim2; )
  171                         if (*m++)
  172                                 return 1;
  173         return (!masks_are_equal);
  174 }
  175 
  176 struct radix_node *
  177 rn_lookup(
  178         const void *v_arg,
  179         const void *m_arg,
  180         struct radix_node_head *head)
  181 {
  182         struct radix_node *x;
  183         const char *netmask = NULL;
  184 
  185         if (m_arg) {
  186                 if ((x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_off)) == 0)
  187                         return (0);
  188                 netmask = x->rn_key;
  189         }
  190         x = rn_match(v_arg, head);
  191         if (x && netmask) {
  192                 while (x && x->rn_mask != netmask)
  193                         x = x->rn_dupedkey;
  194         }
  195         return x;
  196 }
  197 
  198 static int
  199 rn_satisfies_leaf(
  200         const char *trial,
  201         struct radix_node *leaf,
  202         int skip)
  203 {
  204         const char *cp = trial;
  205         const char *cp2 = leaf->rn_key;
  206         const char *cp3 = leaf->rn_mask;
  207         const char *cplim;
  208         int length = min(*(u_char *)cp, *(u_char *)cp2);
  209 
  210         if (cp3 == 0)
  211                 cp3 = rn_ones;
  212         else
  213                 length = min(length, *(u_char *)cp3);
  214         cplim = cp + length; cp3 += skip; cp2 += skip;
  215         for (cp += skip; cp < cplim; cp++, cp2++, cp3++)
  216                 if ((*cp ^ *cp2) & *cp3)
  217                         return 0;
  218         return 1;
  219 }
  220 
  221 struct radix_node *
  222 rn_match(
  223         const void *v_arg,
  224         struct radix_node_head *head)
  225 {
  226         const char * const v = v_arg;
  227         struct radix_node *t = head->rnh_treetop;
  228         struct radix_node *top = t;
  229         struct radix_node *x;
  230         struct radix_node *saved_t;
  231         const char *cp = v;
  232         const char *cp2;
  233         const char *cplim;
  234         int off = t->rn_off;
  235         int vlen = *(u_char *)cp;
  236         int matched_off;
  237         int test, b, rn_b;
  238 
  239         /*
  240          * Open code rn_search(v, top) to avoid overhead of extra
  241          * subroutine call.
  242          */
  243         for (; t->rn_b >= 0; ) {
  244                 if (t->rn_bmask & cp[t->rn_off])
  245                         t = t->rn_r;
  246                 else
  247                         t = t->rn_l;
  248         }
  249         /*
  250          * See if we match exactly as a host destination
  251          * or at least learn how many bits match, for normal mask finesse.
  252          *
  253          * It doesn't hurt us to limit how many bytes to check
  254          * to the length of the mask, since if it matches we had a genuine
  255          * match and the leaf we have is the most specific one anyway;
  256          * if it didn't match with a shorter length it would fail
  257          * with a long one.  This wins big for class B&C netmasks which
  258          * are probably the most common case...
  259          */
  260         if (t->rn_mask)
  261                 vlen = *(u_char *)t->rn_mask;
  262         cp += off; cp2 = t->rn_key + off; cplim = v + vlen;
  263         for (; cp < cplim; cp++, cp2++)
  264                 if (*cp != *cp2)
  265                         goto on1;
  266         /*
  267          * This extra grot is in case we are explicitly asked
  268          * to look up the default.  Ugh!
  269          */
  270         if ((t->rn_flags & RNF_ROOT) && t->rn_dupedkey)
  271                 t = t->rn_dupedkey;
  272         return t;
  273 on1:
  274         test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */
  275         for (b = 7; (test >>= 1) > 0;)
  276                 b--;
  277         matched_off = cp - v;
  278         b += matched_off << 3;
  279         rn_b = -1 - b;
  280         /*
  281          * If there is a host route in a duped-key chain, it will be first.
  282          */
  283         if ((saved_t = t)->rn_mask == 0)
  284                 t = t->rn_dupedkey;
  285         for (; t; t = t->rn_dupedkey)
  286                 /*
  287                  * Even if we don't match exactly as a host,
  288                  * we may match if the leaf we wound up at is
  289                  * a route to a net.
  290                  */
  291                 if (t->rn_flags & RNF_NORMAL) {
  292                         if (rn_b <= t->rn_b)
  293                                 return t;
  294                 } else if (rn_satisfies_leaf(v, t, matched_off))
  295                                 return t;
  296         t = saved_t;
  297         /* start searching up the tree */
  298         do {
  299                 struct radix_mask *m;
  300                 t = t->rn_p;
  301                 m = t->rn_mklist;
  302                 if (m) {
  303                         /*
  304                          * If non-contiguous masks ever become important
  305                          * we can restore the masking and open coding of
  306                          * the search and satisfaction test and put the
  307                          * calculation of "off" back before the "do".
  308                          */
  309                         do {
  310                                 if (m->rm_flags & RNF_NORMAL) {
  311                                         if (rn_b <= m->rm_b)
  312                                                 return (m->rm_leaf);
  313                                 } else {
  314                                         off = min(t->rn_off, matched_off);
  315                                         x = rn_search_m(v, t, m->rm_mask);
  316                                         while (x && x->rn_mask != m->rm_mask)
  317                                                 x = x->rn_dupedkey;
  318                                         if (x && rn_satisfies_leaf(v, x, off))
  319                                                 return x;
  320                                 }
  321                                 m = m->rm_mklist;
  322                         } while (m);
  323                 }
  324         } while (t != top);
  325         return 0;
  326 }
  327 
  328 #ifdef RN_DEBUG
  329 int     rn_nodenum;
  330 struct  radix_node *rn_clist;
  331 int     rn_saveinfo;
  332 int     rn_debug =  1;
  333 #endif
  334 
  335 struct radix_node *
  336 rn_newpair(
  337         const void *v,
  338         int b,
  339         struct radix_node nodes[2])
  340 {
  341         struct radix_node *tt = nodes;
  342         struct radix_node *t = tt + 1;
  343         t->rn_b = b; t->rn_bmask = 0x80 >> (b & 7);
  344         t->rn_l = tt; t->rn_off = b >> 3;
  345         tt->rn_b = -1; tt->rn_key = v; tt->rn_p = t;
  346         tt->rn_flags = t->rn_flags = RNF_ACTIVE;
  347 #ifdef RN_DEBUG
  348         tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
  349         tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt;
  350 #endif
  351         return t;
  352 }
  353 
  354 struct radix_node *
  355 rn_insert(
  356         const void *v_arg,
  357         struct radix_node_head *head,
  358         int *dupentry,
  359         struct radix_node nodes[2])
  360 {
  361         struct radix_node *top = head->rnh_treetop;
  362         struct radix_node *t = rn_search(v_arg, top);
  363         struct radix_node *tt;
  364         const char *v = v_arg;
  365         int head_off = top->rn_off;
  366         int vlen = *((u_char *)v);
  367         const char *cp = v + head_off;
  368         int b;
  369         /*
  370          * Find first bit at which v and t->rn_key differ
  371          */
  372     {
  373         const char *cp2 = t->rn_key + head_off;
  374         const char *cplim = v + vlen;
  375         int cmp_res;
  376 
  377         while (cp < cplim)
  378                 if (*cp2++ != *cp++)
  379                         goto on1;
  380         *dupentry = 1;
  381         return t;
  382 on1:
  383         *dupentry = 0;
  384         cmp_res = (cp[-1] ^ cp2[-1]) & 0xff;
  385         for (b = (cp - v) << 3; cmp_res; b--)
  386                 cmp_res >>= 1;
  387     }
  388     {
  389         struct radix_node *p, *x = top;
  390         cp = v;
  391         do {
  392                 p = x;
  393                 if (cp[x->rn_off] & x->rn_bmask)
  394                         x = x->rn_r;
  395                 else x = x->rn_l;
  396         } while (b > (unsigned) x->rn_b); /* x->rn_b < b && x->rn_b >= 0 */
  397 #ifdef RN_DEBUG
  398         if (rn_debug)
  399                 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p);
  400 #endif
  401         t = rn_newpair(v_arg, b, nodes); tt = t->rn_l;
  402         if ((cp[p->rn_off] & p->rn_bmask) == 0)
  403                 p->rn_l = t;
  404         else
  405                 p->rn_r = t;
  406         x->rn_p = t; t->rn_p = p; /* frees x, p as temp vars below */
  407         if ((cp[t->rn_off] & t->rn_bmask) == 0) {
  408                 t->rn_r = x;
  409         } else {
  410                 t->rn_r = tt; t->rn_l = x;
  411         }
  412 #ifdef RN_DEBUG
  413         if (rn_debug)
  414                 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p);
  415 #endif
  416     }
  417         return (tt);
  418 }
  419 
  420 struct radix_node *
  421 rn_addmask(
  422         const void *n_arg,
  423         int search,
  424         int skip)
  425 {
  426         const char *netmask = n_arg;
  427         const char *cp;
  428         const char *cplim;
  429         struct radix_node *x;
  430         struct radix_node *saved_x;
  431         int b = 0, mlen, j;
  432         int maskduplicated, m0, isnormal;
  433         static int last_zeroed = 0;
  434 
  435         if ((mlen = *(u_char *)netmask) > max_keylen)
  436                 mlen = max_keylen;
  437         if (skip == 0)
  438                 skip = 1;
  439         if (mlen <= skip)
  440                 return (mask_rnhead->rnh_nodes);
  441         if (skip > 1)
  442                 Bcopy(rn_ones + 1, addmask_key + 1, skip - 1);
  443         if ((m0 = mlen) > skip)
  444                 Bcopy(netmask + skip, addmask_key + skip, mlen - skip);
  445         /*
  446          * Trim trailing zeroes.
  447          */
  448         for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;)
  449                 cp--;
  450         mlen = cp - addmask_key;
  451         if (mlen <= skip) {
  452                 if (m0 >= last_zeroed)
  453                         last_zeroed = mlen;
  454                 return (mask_rnhead->rnh_nodes);
  455         }
  456         if (m0 < last_zeroed)
  457                 Bzero(addmask_key + m0, last_zeroed - m0);
  458         *addmask_key = last_zeroed = mlen;
  459         x = rn_search(addmask_key, rn_masktop);
  460         if (Bcmp(addmask_key, x->rn_key, mlen) != 0)
  461                 x = 0;
  462         if (x || search)
  463                 return (x);
  464         R_Malloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x));
  465         if ((saved_x = x) == 0)
  466                 return (0);
  467         Bzero(x, max_keylen + 2 * sizeof (*x));
  468         cp = netmask = (caddr_t)(x + 2);
  469         Bcopy(addmask_key, (caddr_t)(x + 2), mlen);
  470         x = rn_insert(cp, mask_rnhead, &maskduplicated, x);
  471         if (maskduplicated) {
  472                 log(LOG_ERR, "rn_addmask: mask impossibly already in tree\n");
  473                 Free(saved_x);
  474                 return (x);
  475         }
  476         /*
  477          * Calculate index of mask, and check for normalcy.
  478          */
  479         cplim = netmask + mlen; isnormal = 1;
  480         for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;)
  481                 cp++;
  482         if (cp != cplim) {
  483                 for (j = 0x80; (j & *cp) != 0; j >>= 1)
  484                         b++;
  485                 if (*cp != normal_chars[b] || cp != (cplim - 1))
  486                         isnormal = 0;
  487         }
  488         b += (cp - netmask) << 3;
  489         x->rn_b = -1 - b;
  490         if (isnormal)
  491                 x->rn_flags |= RNF_NORMAL;
  492         return (x);
  493 }
  494 
  495 static int      /* XXX: arbitrary ordering for non-contiguous masks */
  496 rn_lexobetter(
  497         const void *m_arg,
  498         const void *n_arg)
  499 {
  500         const u_char *mp = m_arg;
  501         const u_char *np = n_arg;
  502         const u_char *lim;
  503 
  504         if (*mp > *np)
  505                 return 1;  /* not really, but need to check longer one first */
  506         if (*mp == *np)
  507                 for (lim = mp + *mp; mp < lim;)
  508                         if (*mp++ > *np++)
  509                                 return 1;
  510         return 0;
  511 }
  512 
  513 static struct radix_mask *
  514 rn_new_radix_mask(
  515         struct radix_node *tt,
  516         struct radix_mask *next)
  517 {
  518         struct radix_mask *m;
  519 
  520         MKGet(m);
  521         if (m == 0) {
  522                 log(LOG_ERR, "Mask for route not entered\n");
  523                 return (0);
  524         }
  525         Bzero(m, sizeof *m);
  526         m->rm_b = tt->rn_b;
  527         m->rm_flags = tt->rn_flags;
  528         if (tt->rn_flags & RNF_NORMAL)
  529                 m->rm_leaf = tt;
  530         else
  531                 m->rm_mask = tt->rn_mask;
  532         m->rm_mklist = next;
  533         tt->rn_mklist = m;
  534         return m;
  535 }
  536 
  537 struct radix_node *
  538 rn_addroute(
  539         const void *v_arg,
  540         const void *n_arg,
  541         struct radix_node_head *head,
  542         struct radix_node treenodes[2])
  543 {
  544         const char *v = v_arg;
  545         const char *netmask = n_arg;
  546         struct radix_node *t;
  547         struct radix_node *x = 0;
  548         struct radix_node *tt;
  549         struct radix_node *saved_tt;
  550         struct radix_node *top = head->rnh_treetop;
  551         short b = 0, b_leaf = 0;
  552         int keyduplicated;
  553         const char *mmask;
  554         struct radix_mask *m, **mp;
  555 
  556         /*
  557          * In dealing with non-contiguous masks, there may be
  558          * many different routes which have the same mask.
  559          * We will find it useful to have a unique pointer to
  560          * the mask to speed avoiding duplicate references at
  561          * nodes and possibly save time in calculating indices.
  562          */
  563         if (netmask)  {
  564                 if ((x = rn_addmask(netmask, 0, top->rn_off)) == 0)
  565                         return (0);
  566                 b_leaf = x->rn_b;
  567                 b = -1 - x->rn_b;
  568                 netmask = x->rn_key;
  569         }
  570         /*
  571          * Deal with duplicated keys: attach node to previous instance
  572          */
  573         saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes);
  574         if (keyduplicated) {
  575                 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) {
  576                         if (tt->rn_mask == netmask)
  577                                 return (0);
  578                         if (netmask == 0 ||
  579                             (tt->rn_mask &&
  580                              ((b_leaf < tt->rn_b) || /* index(netmask) > node */
  581                                rn_refines(netmask, tt->rn_mask) ||
  582                                rn_lexobetter(netmask, tt->rn_mask))))
  583                                 break;
  584                 }
  585                 /*
  586                  * If the mask is not duplicated, we wouldn't
  587                  * find it among possible duplicate key entries
  588                  * anyway, so the above test doesn't hurt.
  589                  *
  590                  * We sort the masks for a duplicated key the same way as
  591                  * in a masklist -- most specific to least specific.
  592                  * This may require the unfortunate nuisance of relocating
  593                  * the head of the list.
  594                  *
  595                  * We also reverse, or doubly link the list through the
  596                  * parent pointer.
  597                  */
  598                 if (tt == saved_tt) {
  599                         struct  radix_node *xx = x;
  600                         /* link in at head of list */
  601                         (tt = treenodes)->rn_dupedkey = t;
  602                         tt->rn_flags = t->rn_flags;
  603                         tt->rn_p = x = t->rn_p;
  604                         t->rn_p = tt;
  605                         if (x->rn_l == t) x->rn_l = tt; else x->rn_r = tt;
  606                         saved_tt = tt; x = xx;
  607                 } else {
  608                         (tt = treenodes)->rn_dupedkey = t->rn_dupedkey;
  609                         t->rn_dupedkey = tt;
  610                         tt->rn_p = t;
  611                         if (tt->rn_dupedkey)
  612                                 tt->rn_dupedkey->rn_p = tt;
  613                 }
  614 #ifdef RN_DEBUG
  615                 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
  616                 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt;
  617 #endif
  618                 tt->rn_key = (caddr_t) v;
  619                 tt->rn_b = -1;
  620                 tt->rn_flags = RNF_ACTIVE;
  621         }
  622         /*
  623          * Put mask in tree.
  624          */
  625         if (netmask) {
  626                 tt->rn_mask = netmask;
  627                 tt->rn_b = x->rn_b;
  628                 tt->rn_flags |= x->rn_flags & RNF_NORMAL;
  629         }
  630         t = saved_tt->rn_p;
  631         if (keyduplicated)
  632                 goto on2;
  633         b_leaf = -1 - t->rn_b;
  634         if (t->rn_r == saved_tt) x = t->rn_l; else x = t->rn_r;
  635         /* Promote general routes from below */
  636         if (x->rn_b < 0) {
  637             for (mp = &t->rn_mklist; x; x = x->rn_dupedkey)
  638                 if (x->rn_mask && (x->rn_b >= b_leaf) && x->rn_mklist == 0) {
  639                         *mp = m = rn_new_radix_mask(x, 0);
  640                         if (m)
  641                                 mp = &m->rm_mklist;
  642                 }
  643         } else if (x->rn_mklist) {
  644                 /*
  645                  * Skip over masks whose index is > that of new node
  646                  */
  647                 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
  648                         if (m->rm_b >= b_leaf)
  649                                 break;
  650                 t->rn_mklist = m; *mp = 0;
  651         }
  652 on2:
  653         /* Add new route to highest possible ancestor's list */
  654         if ((netmask == 0) || (b > t->rn_b ))
  655                 return tt; /* can't lift at all */
  656         b_leaf = tt->rn_b;
  657         do {
  658                 x = t;
  659                 t = t->rn_p;
  660         } while (b <= t->rn_b && x != top);
  661         /*
  662          * Search through routes associated with node to
  663          * insert new route according to index.
  664          * Need same criteria as when sorting dupedkeys to avoid
  665          * double loop on deletion.
  666          */
  667         for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) {
  668                 if (m->rm_b < b_leaf)
  669                         continue;
  670                 if (m->rm_b > b_leaf)
  671                         break;
  672                 if (m->rm_flags & RNF_NORMAL) {
  673                         mmask = m->rm_leaf->rn_mask;
  674                         if (tt->rn_flags & RNF_NORMAL) {
  675                                 log(LOG_ERR, "Non-unique normal route,"
  676                                     " mask not entered\n");
  677                                 return tt;
  678                         }
  679                 } else
  680                         mmask = m->rm_mask;
  681                 if (mmask == netmask) {
  682                         m->rm_refs++;
  683                         tt->rn_mklist = m;
  684                         return tt;
  685                 }
  686                 if (rn_refines(netmask, mmask) || rn_lexobetter(netmask, mmask))
  687                         break;
  688         }
  689         *mp = rn_new_radix_mask(tt, *mp);
  690         return tt;
  691 }
  692 
  693 struct radix_node *
  694 rn_delete(
  695         const void *v_arg,
  696         const void *netmask_arg,
  697         struct radix_node_head *head)
  698 {
  699         struct radix_node *t;
  700         struct radix_node *p;
  701         struct radix_node *x;
  702         struct radix_node *tt;
  703         struct radix_node *dupedkey;
  704         struct radix_node *saved_tt;
  705         struct radix_node *top;
  706         struct radix_mask *m;
  707         struct radix_mask *saved_m;
  708         struct radix_mask **mp;
  709         const char *v = v_arg;
  710         const char *netmask = netmask_arg;
  711         int b, head_off, vlen;
  712 
  713         x = head->rnh_treetop;
  714         tt = rn_search(v, x);
  715         head_off = x->rn_off;
  716         vlen =  *(u_char *)v;
  717         saved_tt = tt;
  718         top = x;
  719         if (tt == 0 ||
  720             Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off))
  721                 return (0);
  722         /*
  723          * Delete our route from mask lists.
  724          */
  725         if (netmask) {
  726                 if ((x = rn_addmask(netmask, 1, head_off)) == 0)
  727                         return (0);
  728                 netmask = x->rn_key;
  729                 while (tt->rn_mask != netmask)
  730                         if ((tt = tt->rn_dupedkey) == 0)
  731                                 return (0);
  732         }
  733         if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0)
  734                 goto on1;
  735         if (tt->rn_flags & RNF_NORMAL) {
  736                 if (m->rm_leaf != tt || m->rm_refs > 0) {
  737                         log(LOG_ERR, "rn_delete: inconsistent annotation\n");
  738                         return 0;  /* dangling ref could cause disaster */
  739                 }
  740         } else {
  741                 if (m->rm_mask != tt->rn_mask) {
  742                         log(LOG_ERR, "rn_delete: inconsistent annotation\n");
  743                         goto on1;
  744                 }
  745                 if (--m->rm_refs >= 0)
  746                         goto on1;
  747         }
  748         b = -1 - tt->rn_b;
  749         t = saved_tt->rn_p;
  750         if (b > t->rn_b)
  751                 goto on1; /* Wasn't lifted at all */
  752         do {
  753                 x = t;
  754                 t = t->rn_p;
  755         } while (b <= t->rn_b && x != top);
  756         for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
  757                 if (m == saved_m) {
  758                         *mp = m->rm_mklist;
  759                         MKFree(m);
  760                         break;
  761                 }
  762         if (m == 0) {
  763                 log(LOG_ERR, "rn_delete: couldn't find our annotation\n");
  764                 if (tt->rn_flags & RNF_NORMAL)
  765                         return (0); /* Dangling ref to us */
  766         }
  767 on1:
  768         /*
  769          * Eliminate us from tree
  770          */
  771         if (tt->rn_flags & RNF_ROOT)
  772                 return (0);
  773 #ifdef RN_DEBUG
  774         /* Get us out of the creation list */
  775         for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {}
  776         if (t) t->rn_ybro = tt->rn_ybro;
  777 #endif
  778         t = tt->rn_p;
  779         dupedkey = saved_tt->rn_dupedkey;
  780         if (dupedkey) {
  781                 /*
  782                  * Here, tt is the deletion target, and
  783                  * saved_tt is the head of the dupedkey chain.
  784                  */
  785                 if (tt == saved_tt) {
  786                         x = dupedkey; x->rn_p = t;
  787                         if (t->rn_l == tt) t->rn_l = x; else t->rn_r = x;
  788                 } else {
  789                         /* find node in front of tt on the chain */
  790                         for (x = p = saved_tt; p && p->rn_dupedkey != tt;)
  791                                 p = p->rn_dupedkey;
  792                         if (p) {
  793                                 p->rn_dupedkey = tt->rn_dupedkey;
  794                                 if (tt->rn_dupedkey)
  795                                         tt->rn_dupedkey->rn_p = p;
  796                         } else log(LOG_ERR, "rn_delete: couldn't find us\n");
  797                 }
  798                 t = tt + 1;
  799                 if  (t->rn_flags & RNF_ACTIVE) {
  800 #ifndef RN_DEBUG
  801                         *++x = *t; p = t->rn_p;
  802 #else
  803                         b = t->rn_info; *++x = *t; t->rn_info = b; p = t->rn_p;
  804 #endif
  805                         if (p->rn_l == t) p->rn_l = x; else p->rn_r = x;
  806                         x->rn_l->rn_p = x; x->rn_r->rn_p = x;
  807                 }
  808                 goto out;
  809         }
  810         if (t->rn_l == tt) x = t->rn_r; else x = t->rn_l;
  811         p = t->rn_p;
  812         if (p->rn_r == t) p->rn_r = x; else p->rn_l = x;
  813         x->rn_p = p;
  814         /*
  815          * Demote routes attached to us.
  816          */
  817         if (t->rn_mklist) {
  818                 if (x->rn_b >= 0) {
  819                         for (mp = &x->rn_mklist; (m = *mp);)
  820                                 mp = &m->rm_mklist;
  821                         *mp = t->rn_mklist;
  822                 } else {
  823                         /* If there are any key,mask pairs in a sibling
  824                            duped-key chain, some subset will appear sorted
  825                            in the same order attached to our mklist */
  826                         for (m = t->rn_mklist; m && x; x = x->rn_dupedkey)
  827                                 if (m == x->rn_mklist) {
  828                                         struct radix_mask *mm = m->rm_mklist;
  829                                         x->rn_mklist = 0;
  830                                         if (--(m->rm_refs) < 0)
  831                                                 MKFree(m);
  832                                         m = mm;
  833                                 }
  834                         if (m)
  835                                 log(LOG_ERR, "%s %p at %p\n",
  836                                     "rn_delete: Orphaned Mask", m, x);
  837                 }
  838         }
  839         /*
  840          * We may be holding an active internal node in the tree.
  841          */
  842         x = tt + 1;
  843         if (t != x) {
  844 #ifndef RN_DEBUG
  845                 *t = *x;
  846 #else
  847                 b = t->rn_info; *t = *x; t->rn_info = b;
  848 #endif
  849                 t->rn_l->rn_p = t; t->rn_r->rn_p = t;
  850                 p = x->rn_p;
  851                 if (p->rn_l == x) p->rn_l = t; else p->rn_r = t;
  852         }
  853 out:
  854         tt->rn_flags &= ~RNF_ACTIVE;
  855         tt[1].rn_flags &= ~RNF_ACTIVE;
  856         return (tt);
  857 }
  858 
  859 int
  860 rn_walktree(
  861         struct radix_node_head *h,
  862         int (*f)(struct radix_node *, void *),
  863         void *w)
  864 {
  865         int error;
  866         struct radix_node *base;
  867         struct radix_node *next;
  868         struct radix_node *rn = h->rnh_treetop;
  869         /*
  870          * This gets complicated because we may delete the node
  871          * while applying the function f to it, so we need to calculate
  872          * the successor node in advance.
  873          */
  874         /* First time through node, go left */
  875         while (rn->rn_b >= 0)
  876                 rn = rn->rn_l;
  877         for (;;) {
  878                 base = rn;
  879                 /* If at right child go back up, otherwise, go right */
  880                 while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0)
  881                         rn = rn->rn_p;
  882                 /* Find the next *leaf* since next node might vanish, too */
  883                 for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;)
  884                         rn = rn->rn_l;
  885                 next = rn;
  886                 /* Process leaves */
  887                 while ((rn = base) != NULL) {
  888                         base = rn->rn_dupedkey;
  889                         if (!(rn->rn_flags & RNF_ROOT) && (error = (*f)(rn, w)))
  890                                 return (error);
  891                 }
  892                 rn = next;
  893                 if (rn->rn_flags & RNF_ROOT)
  894                         return (0);
  895         }
  896         /* NOTREACHED */
  897 }
  898 
  899 int
  900 rn_inithead(head, off)
  901         void **head;
  902         int off;
  903 {
  904         struct radix_node_head *rnh;
  905 
  906         if (*head)
  907                 return (1);
  908         R_Malloc(rnh, struct radix_node_head *, sizeof (*rnh));
  909         if (rnh == 0)
  910                 return (0);
  911         *head = rnh;
  912         return rn_inithead0(rnh, off);
  913 }
  914 
  915 int
  916 rn_inithead0(rnh, off)
  917         struct radix_node_head *rnh;
  918         int off;
  919 {
  920         struct radix_node *t;
  921         struct radix_node *tt;
  922         struct radix_node *ttt;
  923 
  924         Bzero(rnh, sizeof (*rnh));
  925         t = rn_newpair(rn_zeros, off, rnh->rnh_nodes);
  926         ttt = rnh->rnh_nodes + 2;
  927         t->rn_r = ttt;
  928         t->rn_p = t;
  929         tt = t->rn_l;
  930         tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE;
  931         tt->rn_b = -1 - off;
  932         *ttt = *tt;
  933         ttt->rn_key = rn_ones;
  934         rnh->rnh_addaddr = rn_addroute;
  935         rnh->rnh_deladdr = rn_delete;
  936         rnh->rnh_matchaddr = rn_match;
  937         rnh->rnh_lookup = rn_lookup;
  938         rnh->rnh_walktree = rn_walktree;
  939         rnh->rnh_treetop = t;
  940         return (1);
  941 }
  942 
  943 void
  944 rn_init()
  945 {
  946         char *cp, *cplim;
  947 #ifdef _KERNEL
  948         static int initialized;
  949         __link_set_decl(domains, struct domain);
  950         struct domain *const *dpp;
  951 
  952         if (initialized)
  953                 return;
  954         initialized = 1;
  955 
  956         __link_set_foreach(dpp, domains) {
  957                 if ((*dpp)->dom_maxrtkey > max_keylen)
  958                         max_keylen = (*dpp)->dom_maxrtkey;
  959         }
  960 #ifdef INET
  961         encap_setkeylen();
  962 #endif
  963 #endif
  964         if (max_keylen == 0) {
  965                 log(LOG_ERR,
  966                     "rn_init: radix functions require max_keylen be set\n");
  967                 return;
  968         }
  969         R_Malloc(rn_zeros, char *, 3 * max_keylen);
  970         if (rn_zeros == NULL)
  971                 panic("rn_init");
  972         Bzero(rn_zeros, 3 * max_keylen);
  973         rn_ones = cp = rn_zeros + max_keylen;
  974         addmask_key = cplim = rn_ones + max_keylen;
  975         while (cp < cplim)
  976                 *cp++ = -1;
  977         if (rn_inithead((void *)&mask_rnhead, 0) == 0)
  978                 panic("rn_init 2");
  979 }

Cache object: e85ad72f9ae2bac3766540af7092d560


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.