/src/SockFuzzer/third_party/xnu/bsd/net/radix.c

Source
/*
 * Copyright (c) 2000-2013 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/*
 * Copyright (c) 1988, 1989, 1993
 *  The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *  This product includes software developed by the University of
 *  California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *  @(#)radix.c 8.4 (Berkeley) 11/2/94
 * $FreeBSD: src/sys/net/radix.c,v 1.20.2.2 2001/03/06 00:56:50 obrien Exp $
 */

/*
 * Routines to build and maintain radix trees for routing lookups.
 */
#ifndef _RADIX_H_
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#define M_DONTWAIT M_NOWAIT
#include <sys/domain.h>
#include <sys/syslog.h>
#include <net/radix.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <kern/locks.h>
#endif

static int      rn_walktree_from(struct radix_node_head *h, void *a,
    void *m, walktree_f_t *f, void *w);
static int rn_walktree(struct radix_node_head *, walktree_f_t *, void *);
static struct radix_node
*rn_insert(void *, struct radix_node_head *, int *,
    struct radix_node[2]),
*rn_newpair(void *, int, struct radix_node[2]),
*rn_search(void *, struct radix_node *),
*rn_search_m(void *, struct radix_node *, void *);

static int      max_keylen;
static struct radix_mask *rn_mkfreelist;
static struct radix_node_head *mask_rnhead;
static char *addmask_key;
static char normal_chars[] = {0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1};
static char *rn_zeros, *rn_ones;


#define rn_masktop (mask_rnhead->rnh_treetop)
#undef Bcmp
#define Bcmp(a, b, l) \
  (l == 0 ? 0 : bcmp((caddr_t)(a), (caddr_t)(b), (uint32_t)l))

static int      rn_lexobetter(void *m_arg, void *n_arg);
static struct radix_mask *
rn_new_radix_mask(struct radix_node *tt,
    struct radix_mask *next);
static int rn_satisfies_leaf(char *trial, struct radix_node *leaf, int skip,
    rn_matchf_t *f, void *w);

#define RN_MATCHF(rn, f, arg)   (f == NULL || (*f)((rn), arg))

/*
 * The data structure for the keys is a radix tree with one way
 * branching removed.  The index rn_bit at an internal node n represents a bit
 * position to be tested.  The tree is arranged so that all descendants
 * of a node n have keys whose bits all agree up to position rn_bit - 1.
 * (We say the index of n is rn_bit.)
 *
 * There is at least one descendant which has a one bit at position rn_bit,
 * and at least one with a zero there.
 *
 * A route is determined by a pair of key and mask.  We require that the
 * bit-wise logical and of the key and mask to be the key.
 * We define the index of a route to associated with the mask to be
 * the first bit number in the mask where 0 occurs (with bit number 0
 * representing the highest order bit).
 *
 * We say a mask is normal if every bit is 0, past the index of the mask.
 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_bit,
 * and m is a normal mask, then the route applies to every descendant of n.
 * If the index(m) < rn_bit, this implies the trailing last few bits of k
 * before bit b are all 0, (and hence consequently true of every descendant
 * of n), so the route applies to all descendants of the node as well.
 *
 * Similar logic shows that a non-normal mask m such that
 * index(m) <= index(n) could potentially apply to many children of n.
 * Thus, for each non-host route, we attach its mask to a list at an internal
 * node as high in the tree as we can go.
 *
 * The present version of the code makes use of normal routes in short-
 * circuiting an explict mask and compare operation when testing whether
 * a key satisfies a normal route, and also in remembering the unique leaf
 * that governs a subtree.
 */

static struct radix_node *
rn_search(void *v_arg, struct radix_node *head)
{
  struct radix_node *x;
  caddr_t v;

  for (x = head, v = v_arg; x->rn_bit >= 0;) {
    if (x->rn_bmask & v[x->rn_offset]) {
      x = x->rn_right;
    } else {
      x = x->rn_left;
    }
  }
  return x;
}

static struct radix_node *
rn_search_m(void *v_arg, struct radix_node *head, void *m_arg)
{
  struct radix_node *x;
  caddr_t v = v_arg, m = m_arg;

  for (x = head; x->rn_bit >= 0;) {
    if ((x->rn_bmask & m[x->rn_offset]) &&
        (x->rn_bmask & v[x->rn_offset])) {
      x = x->rn_right;
    } else {
      x = x->rn_left;
    }
  }
  return x;
}

int
rn_refines(void *m_arg, void *n_arg)
{
  caddr_t m = m_arg, n = n_arg;
  caddr_t lim, lim2 = lim = n + *(u_char *)n;
  int longer = (*(u_char *)n++) - (int)(*(u_char *)m++);
  int masks_are_equal = 1;

  if (longer > 0) {
    lim -= longer;
  }
  while (n < lim) {
    if (*n & ~(*m)) {
      return 0;
    }
    if (*n++ != *m++) {
      masks_are_equal = 0;
    }
  }
  while (n < lim2) {
    if (*n++) {
      return 0;
    }
  }
  if (masks_are_equal && (longer < 0)) {
    for (lim2 = m - longer; m < lim2;) {
      if (*m++) {
        return 1;
      }
    }
  }
  return !masks_are_equal;
}

struct radix_node *
rn_lookup(void *v_arg, void *m_arg, struct radix_node_head *head)
{
  return rn_lookup_args(v_arg, m_arg, head, NULL, NULL);
}

struct radix_node *
rn_lookup_args(void *v_arg, void *m_arg, struct radix_node_head *head,
    rn_matchf_t *f, void *w)
{
  struct radix_node *x;
  caddr_t netmask = NULL;

  if (m_arg) {
    x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_offset);
    if (x == 0) {
      return NULL;
    }
    netmask = x->rn_key;
  }
  x = rn_match_args(v_arg, head, f, w);
  if (x && netmask) {
    while (x && x->rn_mask != netmask) {
      x = x->rn_dupedkey;
    }
  }
  return x;
}

/*
 * Returns true if address 'trial' has no bits differing from the
 * leaf's key when compared under the leaf's mask.  In other words,
 * returns true when 'trial' matches leaf.  If a leaf-matching
 * routine is passed in, it is also used to find a match on the
 * conditions defined by the caller of rn_match.
 */
static int
rn_satisfies_leaf(char *trial, struct radix_node *leaf, int skip,
    rn_matchf_t *f, void *w)
{
  char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask;
  char *cplim;
  int length = min(*(u_char *)cp, *(u_char *)cp2);

  if (cp3 == 0) {
    cp3 = rn_ones;
  } else {
    length = min(length, *(u_char *)cp3);
  }
  cplim = cp + length; cp3 += skip; cp2 += skip;
  for (cp += skip; cp < cplim; cp++, cp2++, cp3++) {
    if ((*cp ^ *cp2) & *cp3) {
      return 0;
    }
  }

  return RN_MATCHF(leaf, f, w);
}

struct radix_node *
rn_match(void *v_arg, struct radix_node_head *head)
{
  return rn_match_args(v_arg, head, NULL, NULL);
}

struct radix_node *
rn_match_args(void *v_arg, struct radix_node_head *head,
    rn_matchf_t *f, void *w)
{
  caddr_t v = v_arg;
  struct radix_node *t = head->rnh_treetop, *x;
  caddr_t cp = v, cp2;
  caddr_t cplim;
  struct radix_node *saved_t, *top = t;
  int off = t->rn_offset, vlen = *(u_char *)cp, matched_off;
  int test, b, rn_bit;

  /*
   * Open code rn_search(v, top) to avoid overhead of extra
   * subroutine call.
   */
  for (; t->rn_bit >= 0;) {
    if (t->rn_bmask & cp[t->rn_offset]) {
      t = t->rn_right;
    } else {
      t = t->rn_left;
    }
  }
  /*
   * See if we match exactly as a host destination
   * or at least learn how many bits match, for normal mask finesse.
   *
   * It doesn't hurt us to limit how many bytes to check
   * to the length of the mask, since if it matches we had a genuine
   * match and the leaf we have is the most specific one anyway;
   * if it didn't match with a shorter length it would fail
   * with a long one.  This wins big for class B&C netmasks which
   * are probably the most common case...
   */
  if (t->rn_mask) {
    vlen = *(u_char *)t->rn_mask;
  }
  cp += off; cp2 = t->rn_key + off; cplim = v + vlen;
  for (; cp < cplim; cp++, cp2++) {
    if (*cp != *cp2) {
      goto on1;
    }
  }
  /*
   * This extra grot is in case we are explicitly asked
   * to look up the default.  Ugh!
   *
   * Never return the root node itself, it seems to cause a
   * lot of confusion.
   */
  if (t->rn_flags & RNF_ROOT) {
    t = t->rn_dupedkey;
  }
  if (t == NULL || RN_MATCHF(t, f, w)) {
    return t;
  } else {
    /*
     * Although we found an exact match on the key,
     * f() is looking for some other criteria as well.
     * Continue looking as if the exact match failed.
     */
    if (t->rn_parent->rn_flags & RNF_ROOT) {
      /* Hit the top; have to give up */
      return NULL;
    }
    b = 0;
    goto keeplooking;
  }
on1:
  test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */
  for (b = 7; (test >>= 1) > 0;) {
    b--;
  }
keeplooking:
  matched_off = cp - v;
  b += matched_off << 3;
  rn_bit = -1 - b;
  /*
   * If there is a host route in a duped-key chain, it will be first.
   */
  if ((saved_t = t)->rn_mask == 0) {
    t = t->rn_dupedkey;
  }
  for (; t; t = t->rn_dupedkey) {
    /*
     * Even if we don't match exactly as a host,
     * we may match if the leaf we wound up at is
     * a route to a net.
     */
    if (t->rn_flags & RNF_NORMAL) {
      if ((rn_bit <= t->rn_bit) && RN_MATCHF(t, f, w)) {
        return t;
      }
    } else if (rn_satisfies_leaf(v, t, matched_off, f, w)) {
      return t;
    }
  }
  t = saved_t;
  /* start searching up the tree */
  do {
    struct radix_mask *m;
    t = t->rn_parent;
    m = t->rn_mklist;
    /*
     * If non-contiguous masks ever become important
     * we can restore the masking and open coding of
     * the search and satisfaction test and put the
     * calculation of "off" back before the "do".
     */
    while (m) {
      if (m->rm_flags & RNF_NORMAL) {
        if ((rn_bit <= m->rm_bit) &&
            RN_MATCHF(m->rm_leaf, f, w)) {
          return m->rm_leaf;
        }
      } else {
        off = min(t->rn_offset, matched_off);
        x = rn_search_m(v, t, m->rm_mask);
        while (x && x->rn_mask != m->rm_mask) {
          x = x->rn_dupedkey;
        }
        if (x && rn_satisfies_leaf(v, x, off, f, w)) {
          return x;
        }
      }
      m = m->rm_mklist;
    }
  } while (t != top);
  return NULL;
}

#ifdef RN_DEBUG
int     rn_nodenum;
struct  radix_node *rn_clist;
int     rn_saveinfo;
int     rn_debug =  1;
#endif

static struct radix_node *
rn_newpair(void *v, int b, struct radix_node nodes[2])
{
  struct radix_node *tt = nodes, *t = tt + 1;
  t->rn_bit = b;
  t->rn_bmask = 0x80 >> (b & 7);
  t->rn_left = tt;
  t->rn_offset = b >> 3;
  tt->rn_bit = -1;
  tt->rn_key = (caddr_t)v;
  tt->rn_parent = t;
  tt->rn_flags = t->rn_flags = RNF_ACTIVE;
  tt->rn_mklist = t->rn_mklist = NULL;
#ifdef RN_DEBUG
  tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
  tt->rn_twin = t;
  tt->rn_ybro = rn_clist;
  rn_clist = tt;
#endif
  return t;
}

static struct radix_node *
rn_insert(void *v_arg, struct radix_node_head *head, int *dupentry,
    struct radix_node nodes[2])
{
  caddr_t v = v_arg;
  struct radix_node *top = head->rnh_treetop;
  int head_off = top->rn_offset, vlen = (int)*((u_char *)v);
  struct radix_node *t = rn_search(v_arg, top);
  caddr_t cp = v + head_off;
  int b;
  struct radix_node *tt;
  /*
   * Find first bit at which v and t->rn_key differ
   */
  {
    caddr_t cp2 = t->rn_key + head_off;
    int cmp_res;
    caddr_t cplim = v + vlen;

    while (cp < cplim) {
      if (*cp2++ != *cp++) {
        goto on1;
      }
    }
    *dupentry = 1;
    return t;
on1:
    *dupentry = 0;
    cmp_res = (cp[-1] ^ cp2[-1]) & 0xff;
    for (b = (cp - v) << 3; cmp_res; b--) {
      cmp_res >>= 1;
    }
  }
  {
    struct radix_node *p, *x = top;
    cp = v;
    do {
      p = x;
      if (cp[x->rn_offset] & x->rn_bmask) {
        x = x->rn_right;
      } else {
        x = x->rn_left;
      }
    } while (b > (unsigned) x->rn_bit);
    /* x->rn_bit < b && x->rn_bit >= 0 */
#ifdef RN_DEBUG
    if (rn_debug) {
      log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p);
    }
#endif
    t = rn_newpair(v_arg, b, nodes);
    tt = t->rn_left;
    if ((cp[p->rn_offset] & p->rn_bmask) == 0) {
      p->rn_left = t;
    } else {
      p->rn_right = t;
    }
    x->rn_parent = t;
    t->rn_parent = p; /* frees x, p as temp vars below */
    if ((cp[t->rn_offset] & t->rn_bmask) == 0) {
      t->rn_right = x;
    } else {
      t->rn_right = tt;
      t->rn_left = x;
    }
#ifdef RN_DEBUG
    if (rn_debug) {
      log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p);
    }
#endif
  }
  return tt;
}

struct radix_node *
rn_addmask(void *n_arg, int search, int skip)
{
  caddr_t netmask = (caddr_t)n_arg;
  struct radix_node *x;
  caddr_t cp, cplim;
  int b = 0, mlen, j;
  int maskduplicated, m0, isnormal;
  struct radix_node *saved_x;
  static int last_zeroed = 0;

  if ((mlen = *(u_char *)netmask) > max_keylen) {
    mlen = max_keylen;
  }
  if (skip == 0) {
    skip = 1;
  }
  if (mlen <= skip) {
    return mask_rnhead->rnh_nodes;
  }
  if (skip > 1) {
    Bcopy(rn_ones + 1, addmask_key + 1, skip - 1);
  }
  if ((m0 = mlen) > skip) {
    Bcopy(netmask + skip, addmask_key + skip, mlen - skip);
  }
  /*
   * Trim trailing zeroes.
   */
  for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;) {
    cp--;
  }
  mlen = cp - addmask_key;
  if (mlen <= skip) {
    if (m0 >= last_zeroed) {
      last_zeroed = mlen;
    }
    return mask_rnhead->rnh_nodes;
  }
  if (m0 < last_zeroed) {
    Bzero(addmask_key + m0, last_zeroed - m0);
  }
  *addmask_key = last_zeroed = mlen;
  x = rn_search(addmask_key, rn_masktop);
  if (Bcmp(addmask_key, x->rn_key, mlen) != 0) {
    x = NULL;
  }
  if (x || search) {
    return x;
  }
  R_Malloc(x, struct radix_node *, max_keylen + 2 * sizeof(*x));
  if ((saved_x = x) == 0) {
    return NULL;
  }
  Bzero(x, max_keylen + 2 * sizeof(*x));
  netmask = cp = (caddr_t)(x + 2);
  Bcopy(addmask_key, cp, mlen);
  x = rn_insert(cp, mask_rnhead, &maskduplicated, x);
  if (maskduplicated) {
    log(LOG_ERR, "rn_addmask: mask impossibly already in tree");
    R_Free(saved_x);
    return x;
  }
  mask_rnhead->rnh_cnt++;
  /*
   * Calculate index of mask, and check for normalcy.
   */
  cplim = netmask + mlen; isnormal = 1;
  for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;) {
    cp++;
  }
  if (cp != cplim) {
    for (j = 0x80; (j & *cp) != 0; j >>= 1) {
      b++;
    }
    if (*cp != normal_chars[b] || cp != (cplim - 1)) {
      isnormal = 0;
    }
  }
  b += (cp - netmask) << 3;
  x->rn_bit = -1 - b;
  if (isnormal) {
    x->rn_flags |= RNF_NORMAL;
  }
  return x;
}

static int
/* XXX: arbitrary ordering for non-contiguous masks */
rn_lexobetter(void *m_arg, void *n_arg)
{
  u_char *mp = m_arg, *np = n_arg, *lim;

  if (*mp > *np) {
    return 1;  /* not really, but need to check longer one first */
  }
  if (*mp == *np) {
    for (lim = mp + *mp; mp < lim;) {
      if (*mp++ > *np++) {
        return 1;
      }
    }
  }
  return 0;
}

static struct radix_mask *
rn_new_radix_mask(struct radix_node *tt, struct radix_mask *next)
{
  struct radix_mask *m;

  MKGet(m);
  if (m == 0) {
    log(LOG_ERR, "Mask for route not entered\n");
    return NULL;
  }
  Bzero(m, sizeof *m);
  m->rm_bit = tt->rn_bit;
  m->rm_flags = tt->rn_flags;
  if (tt->rn_flags & RNF_NORMAL) {
    m->rm_leaf = tt;
  } else {
    m->rm_mask = tt->rn_mask;
  }
  m->rm_mklist = next;
  tt->rn_mklist = m;
  return m;
}

struct radix_node *
rn_addroute(void *v_arg, void *n_arg, struct radix_node_head *head,
    struct radix_node treenodes[2])
{
  caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg;
  struct radix_node *t, *x = NULL, *tt;
  struct radix_node *saved_tt, *top = head->rnh_treetop;
  short b = 0, b_leaf = 0;
  int keyduplicated;
  caddr_t mmask;
  struct radix_mask *m, **mp;

  /*
   * In dealing with non-contiguous masks, there may be
   * many different routes which have the same mask.
   * We will find it useful to have a unique pointer to
   * the mask to speed avoiding duplicate references at
   * nodes and possibly save time in calculating indices.
   */
  if (netmask) {
    if ((x = rn_addmask(netmask, 0, top->rn_offset)) == 0) {
      return NULL;
    }
    b_leaf = x->rn_bit;
    b = -1 - x->rn_bit;
    netmask = x->rn_key;
  }
  /*
   * Deal with duplicated keys: attach node to previous instance
   */
  saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes);
  if (keyduplicated) {
    for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) {
      if (tt->rn_mask == netmask) {
        return NULL;
      }
      if (netmask == 0 ||
          (tt->rn_mask &&
          ((b_leaf < tt->rn_bit)  /* index(netmask) > node */
          || rn_refines(netmask, tt->rn_mask)
          || rn_lexobetter(netmask, tt->rn_mask)))) {
        break;
      }
    }
    /*
     * If the mask is not duplicated, we wouldn't
     * find it among possible duplicate key entries
     * anyway, so the above test doesn't hurt.
     *
     * We sort the masks for a duplicated key the same way as
     * in a masklist -- most specific to least specific.
     * This may require the unfortunate nuisance of relocating
     * the head of the list.
     */
    if (tt == saved_tt) {
      struct  radix_node *xx = x;
      /* link in at head of list */
      (tt = treenodes)->rn_dupedkey = t;
      tt->rn_flags = t->rn_flags;
      tt->rn_parent = x = t->rn_parent;
      t->rn_parent = tt;                      /* parent */
      if (x->rn_left == t) {
        x->rn_left = tt;
      } else {
        x->rn_right = tt;
      }
      saved_tt = tt; x = xx;
    } else {
      (tt = treenodes)->rn_dupedkey = t->rn_dupedkey;
      t->rn_dupedkey = tt;
      tt->rn_parent = t;                      /* parent */
      if (tt->rn_dupedkey) {                  /* parent */
        tt->rn_dupedkey->rn_parent = tt; /* parent */
      }
    }
#ifdef RN_DEBUG
    t = tt + 1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
    tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt;
#endif
    tt->rn_key = (caddr_t) v;
    tt->rn_bit = -1;
    tt->rn_flags = RNF_ACTIVE;
  }
  head->rnh_cnt++;
  /*
   * Put mask in tree.
   */
  if (netmask) {
    tt->rn_mask = netmask;
    tt->rn_bit = x->rn_bit;
    tt->rn_flags |= x->rn_flags & RNF_NORMAL;
  }
  t = saved_tt->rn_parent;
  if (keyduplicated) {
    goto on2;
  }
  b_leaf = -1 - t->rn_bit;
  if (t->rn_right == saved_tt) {
    x = t->rn_left;
  } else {
    x = t->rn_right;
  }
  /* Promote general routes from below */
  if (x->rn_bit < 0) {
    for (mp = &t->rn_mklist; x; x = x->rn_dupedkey) {
      if (x->rn_mask && (x->rn_bit >= b_leaf) && x->rn_mklist == 0) {
        *mp = m = rn_new_radix_mask(x, NULL);
        if (m) {
          mp = &m->rm_mklist;
        }
      }
    }
  } else if (x->rn_mklist) {
    /*
     * Skip over masks whose index is > that of new node
     */
    for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) {
      if (m->rm_bit >= b_leaf) {
        break;
      }
    }
    t->rn_mklist = m; *mp = NULL;
  }
on2:
  /* Add new route to highest possible ancestor's list */
  if ((netmask == 0) || (b > t->rn_bit)) {
    return tt; /* can't lift at all */
  }
  b_leaf = tt->rn_bit;
  do {
    x = t;
    t = t->rn_parent;
  } while (b <= t->rn_bit && x != top);
  /*
   * Search through routes associated with node to
   * insert new route according to index.
   * Need same criteria as when sorting dupedkeys to avoid
   * double loop on deletion.
   */
  for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) {
    if (m->rm_bit < b_leaf) {
      continue;
    }
    if (m->rm_bit > b_leaf) {
      break;
    }
    if (m->rm_flags & RNF_NORMAL) {
      mmask = m->rm_leaf->rn_mask;
      if (tt->rn_flags & RNF_NORMAL) {
        log(LOG_ERR,
            "Non-unique normal route, mask not entered");
        return tt;
      }
    } else {
      mmask = m->rm_mask;
    }
    if (mmask == netmask) {
      m->rm_refs++;
      tt->rn_mklist = m;
      return tt;
    }
    if (rn_refines(netmask, mmask)
        || rn_lexobetter(netmask, mmask)) {
      break;
    }
  }
  *mp = rn_new_radix_mask(tt, *mp);
  return tt;
}

struct radix_node *
rn_delete(void *v_arg, void *netmask_arg, struct radix_node_head *head)
{
  struct radix_node *t, *p, *x, *tt;
  struct radix_mask *m, *saved_m, **mp;
  struct radix_node *dupedkey, *saved_tt, *top;
  caddr_t v, netmask;
  int b, head_off, vlen;

  v = v_arg;
  netmask = netmask_arg;
  x = head->rnh_treetop;
  tt = rn_search(v, x);
  head_off = x->rn_offset;
  vlen =  *(u_char *)v;
  saved_tt = tt;
  top = x;
  if (tt == 0 ||
      Bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off)) {
    return NULL;
  }
  /*
   * Delete our route from mask lists.
   */
  if (netmask) {
    if ((x = rn_addmask(netmask, 1, head_off)) == 0) {
      return NULL;
    }
    netmask = x->rn_key;
    while (tt->rn_mask != netmask) {
      if ((tt = tt->rn_dupedkey) == 0) {
        return NULL;
      }
    }
  }
  if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0) {
    goto on1;
  }
  if (tt->rn_flags & RNF_NORMAL) {
    if (m->rm_leaf != tt || m->rm_refs > 0) {
      log(LOG_ERR, "rn_delete: inconsistent annotation\n");
      return NULL;  /* dangling ref could cause disaster */
    }
  } else {
    if (m->rm_mask != tt->rn_mask) {
      log(LOG_ERR, "rn_delete: inconsistent annotation\n");
      goto on1;
    }
    if (--m->rm_refs >= 0) {
      goto on1;
    }
  }
  b = -1 - tt->rn_bit;
  t = saved_tt->rn_parent;
  if (b > t->rn_bit) {
    goto on1; /* Wasn't lifted at all */
  }
  do {
    x = t;
    t = t->rn_parent;
  } while (b <= t->rn_bit && x != top);
  for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) {
    if (m == saved_m) {
      *mp = m->rm_mklist;
      MKFree(m);
      break;
    }
  }
  if (m == 0) {
    log(LOG_ERR, "rn_delete: couldn't find our annotation\n");
    if (tt->rn_flags & RNF_NORMAL) {
      return NULL; /* Dangling ref to us */
    }
  }
on1:
  /*
   * Eliminate us from tree
   */
  if (tt->rn_flags & RNF_ROOT) {
    return NULL;
  }
  head->rnh_cnt--;
#ifdef RN_DEBUG
  /* Get us out of the creation list */
  for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {
  }
  if (t) {
    t->rn_ybro = tt->rn_ybro;
  }
#endif
  t = tt->rn_parent;
  dupedkey = saved_tt->rn_dupedkey;
  if (dupedkey) {
    /*
     * at this point, tt is the deletion target and saved_tt
     * is the head of the dupekey chain
     */
    if (tt == saved_tt) {
      /* remove from head of chain */
      x = dupedkey; x->rn_parent = t;
      if (t->rn_left == tt) {
        t->rn_left = x;
      } else {
        t->rn_right = x;
      }
    } else {
      /* find node in front of tt on the chain */
      for (x = p = saved_tt; p && p->rn_dupedkey != tt;) {
        p = p->rn_dupedkey;
      }
      if (p) {
        p->rn_dupedkey = tt->rn_dupedkey;
        if (tt->rn_dupedkey) {          /* parent */
          tt->rn_dupedkey->rn_parent = p;
        }
        /* parent */
      } else {
        log(LOG_ERR, "rn_delete: couldn't find us\n");
      }
    }
    t = tt + 1;
    if (t->rn_flags & RNF_ACTIVE) {
#ifndef RN_DEBUG
      *++x = *t;
      p = t->rn_parent;
#else
      b = t->rn_info;
      *++x = *t;
      t->rn_info = b;
      p = t->rn_parent;
#endif
      if (p->rn_left == t) {
        p->rn_left = x;
      } else {
        p->rn_right = x;
      }
      x->rn_left->rn_parent = x;
      x->rn_right->rn_parent = x;
    }
    goto out;
  }
  if (t->rn_left == tt) {
    x = t->rn_right;
  } else {
    x = t->rn_left;
  }
  p = t->rn_parent;
  if (p->rn_right == t) {
    p->rn_right = x;
  } else {
    p->rn_left = x;
  }
  x->rn_parent = p;
  /*
   * Demote routes attached to us.
   */
  if (t->rn_mklist) {
    if (x->rn_bit >= 0) {
      for (mp = &x->rn_mklist; (m = *mp);) {
        mp = &m->rm_mklist;
      }
      *mp = t->rn_mklist;
    } else {
      /* If there are any key,mask pairs in a sibling
       *  duped-key chain, some subset will appear sorted
       *  in the same order attached to our mklist */
      for (m = t->rn_mklist; m && x; x = x->rn_dupedkey) {
        if (m == x->rn_mklist) {
          struct radix_mask *mm = m->rm_mklist;
          x->rn_mklist = NULL;
          if (--(m->rm_refs) < 0) {
            MKFree(m);
          }
          m = mm;
        }
      }
      if (m) {
        log(LOG_ERR, "rn_delete: Orphaned Mask "
            "0x%llx at 0x%llx\n",
            (uint64_t)VM_KERNEL_ADDRPERM(m),
            (uint64_t)VM_KERNEL_ADDRPERM(x));
      }
    }
  }
  /*
   * We may be holding an active internal node in the tree.
   */
  x = tt + 1;
  if (t != x) {
#ifndef RN_DEBUG
    *t = *x;
#else
    b = t->rn_info;
    *t = *x;
    t->rn_info = b;
#endif
    t->rn_left->rn_parent = t;
    t->rn_right->rn_parent = t;
    p = x->rn_parent;
    if (p->rn_left == x) {
      p->rn_left = t;
    } else {
      p->rn_right = t;
    }
  }
out:
  tt->rn_flags &= ~RNF_ACTIVE;
  tt[1].rn_flags &= ~RNF_ACTIVE;
  return tt;
}

/*
 * This is the same as rn_walktree() except for the parameters and the
 * exit.
 */
static int
rn_walktree_from(struct radix_node_head *h, void *a, void *m, walktree_f_t *f,
    void *w)
{
  int error;
  struct radix_node *base, *next;
  u_char *xa = (u_char *)a;
  u_char *xm = (u_char *)m;
  struct radix_node *rn, *last;
  int stopping;
  int lastb;
  int rnh_cnt;

  /*
   * This gets complicated because we may delete the node while
   * applying the function f to it; we cannot simply use the next
   * leaf as the successor node in advance, because that leaf may
   * be removed as well during deletion when it is a clone of the
   * current node.  When that happens, we would end up referring
   * to an already-freed radix node as the successor node.  To get
   * around this issue, if we detect that the radix tree has changed
   * in dimension (smaller than before), we simply restart the walk
   * from the top of tree.
   */
restart:
  last = NULL;
  stopping = 0;
  rnh_cnt = h->rnh_cnt;

  /*
   * rn_search_m is sort-of-open-coded here.
   */
  for (rn = h->rnh_treetop; rn->rn_bit >= 0;) {
    last = rn;
    if (!(rn->rn_bmask & xm[rn->rn_offset])) {
      break;
    }

    if (rn->rn_bmask & xa[rn->rn_offset]) {
      rn = rn->rn_right;
    } else {
      rn = rn->rn_left;
    }
  }

  /*
   * Two cases: either we stepped off the end of our mask,
   * in which case last == rn, or we reached a leaf, in which
   * case we want to start from the last node we looked at.
   * Either way, last is the node we want to start from.
   */
  rn = last;
  lastb = rn->rn_bit;

  /* First time through node, go left */
  while (rn->rn_bit >= 0) {
    rn = rn->rn_left;
  }

  while (!stopping) {
    base = rn;
    /* If at right child go back up, otherwise, go right */
    while (rn->rn_parent->rn_right == rn
        && !(rn->rn_flags & RNF_ROOT)) {
      rn = rn->rn_parent;

      /* if went up beyond last, stop */
      if (rn->rn_bit <= lastb) {
        stopping = 1;
        /*
         * XXX we should jump to the 'Process leaves'
         * part, because the values of 'rn' and 'next'
         * we compute will not be used. Not a big deal
         * because this loop will terminate, but it is
         * inefficient and hard to understand!
         */
      }
    }

    /*
     * The following code (bug fix) inherited from FreeBSD is
     * currently disabled, because our implementation uses the
     * RTF_PRCLONING scheme that has been abandoned in current
     * FreeBSD release.  The scheme involves setting such a flag
     * for the default route entry, and therefore all off-link
     * destinations would become clones of that entry.  Enabling
     * the following code would be problematic at this point,
     * because the removal of default route would cause only
     * the left-half of the tree to be traversed, leaving the
     * right-half untouched.  If there are clones of the entry
     * that reside in that right-half, they would not be deleted
     * and would linger around until they expire or explicitly
     * deleted, which is a very bad thing.
     *
     * This code should be uncommented only after we get rid
     * of the RTF_PRCLONING scheme.
     */
#if 0
    /*
     * At the top of the tree, no need to traverse the right
     * half, prevent the traversal of the entire tree in the
     * case of default route.
     */
    if (rn->rn_parent->rn_flags & RNF_ROOT) {
      stopping = 1;
    }
#endif

    /* Find the next *leaf* to start from */
    for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;) {
      rn = rn->rn_left;
    }
    next = rn;
    /* Process leaves */
    while ((rn = base) != 0) {
      base = rn->rn_dupedkey;
      if (!(rn->rn_flags & RNF_ROOT)
          && (error = (*f)(rn, w))) {
        return error;
      }
    }
    /* If one or more nodes got deleted, restart from top */
    if (h->rnh_cnt < rnh_cnt) {
      goto restart;
    }
    rn = next;
    if (rn->rn_flags & RNF_ROOT) {
      stopping = 1;
    }
  }
  return 0;
}

static int
rn_walktree(struct radix_node_head *h, walktree_f_t *f, void *w)
{
  int error;
  struct radix_node *base, *next;
  struct radix_node *rn;
  int rnh_cnt;

  /*
   * This gets complicated because we may delete the node while
   * applying the function f to it; we cannot simply use the next
   * leaf as the successor node in advance, because that leaf may
   * be removed as well during deletion when it is a clone of the
   * current node.  When that happens, we would end up referring
   * to an already-freed radix node as the successor node.  To get
   * around this issue, if we detect that the radix tree has changed
   * in dimension (smaller than before), we simply restart the walk
   * from the top of tree.
   */
restart:
  rn = h->rnh_treetop;
  rnh_cnt = h->rnh_cnt;

  /* First time through node, go left */
  while (rn->rn_bit >= 0) {
    rn = rn->rn_left;
  }
  for (;;) {
    base = rn;
    /* If at right child go back up, otherwise, go right */
    while (rn->rn_parent->rn_right == rn &&
        (rn->rn_flags & RNF_ROOT) == 0) {
      rn = rn->rn_parent;
    }
    /* Find the next *leaf* to start from */
    for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;) {
      rn = rn->rn_left;
    }
    next = rn;
    /* Process leaves */
    while ((rn = base) != NULL) {
      base = rn->rn_dupedkey;
      if (!(rn->rn_flags & RNF_ROOT)
          && (error = (*f)(rn, w))) {
        return error;
      }
    }
    /* If one or more nodes got deleted, restart from top */
    if (h->rnh_cnt < rnh_cnt) {
      goto restart;
    }
    rn = next;
    if (rn->rn_flags & RNF_ROOT) {
      return 0;
    }
  }
  /* NOTREACHED */
}

int
rn_inithead(void **head, int off)
{
  struct radix_node_head *rnh;
  struct radix_node *t, *tt, *ttt;
  if (*head) {
    return 1;
  }
  R_Malloc(rnh, struct radix_node_head *, sizeof(*rnh));
  if (rnh == 0) {
    return 0;
  }
  Bzero(rnh, sizeof(*rnh));
  *head = rnh;
  t = rn_newpair(rn_zeros, off, rnh->rnh_nodes);
  ttt = rnh->rnh_nodes + 2;
  t->rn_right = ttt;
  t->rn_parent = t;
  tt = t->rn_left;
  tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE;
  tt->rn_bit = -1 - off;
  *ttt = *tt;
  ttt->rn_key = rn_ones;
  rnh->rnh_addaddr = rn_addroute;
  rnh->rnh_deladdr = rn_delete;
  rnh->rnh_matchaddr = rn_match;
  rnh->rnh_matchaddr_args = rn_match_args;
  rnh->rnh_lookup = rn_lookup;
  rnh->rnh_lookup_args = rn_lookup_args;
  rnh->rnh_walktree = rn_walktree;
  rnh->rnh_walktree_from = rn_walktree_from;
  rnh->rnh_treetop = t;
  rnh->rnh_cnt = 3;
  return 1;
}

void
rn_init(void)
{
  char *cp, *cplim;
  struct domain *dom;

  /* lock already held when rn_init is called */
  TAILQ_FOREACH(dom, &domains, dom_entry) {
    if (dom->dom_maxrtkey > max_keylen) {
      max_keylen = dom->dom_maxrtkey;
    }
  }
  if (max_keylen == 0) {
    log(LOG_ERR,
        "rn_init: radix functions require max_keylen be set\n");
    return;
  }
  R_Malloc(rn_zeros, char *, 3 * max_keylen);
  if (rn_zeros == NULL) {
    panic("rn_init");
  }
  Bzero(rn_zeros, 3 * max_keylen);
  rn_ones = cp = rn_zeros + max_keylen;
  addmask_key = cplim = rn_ones + max_keylen;
  while (cp < cplim) {
    *cp++ = -1;
  }
  if (rn_inithead((void **)&mask_rnhead, 0) == 0) {
    panic("rn_init 2");
  }
}

Coverage Report

Created: 2026-06-25 06:11