radix.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* 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
*
* 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 8.6 (Berkeley) 10/17/95
*/
/*
* Routines to build and maintain radix trees for routing lookups.
*/
#endif
#ifndef __P
# ifdef __STDC__
# define __P(x) x
# else
# define __P(x) ()
# endif
#endif
#ifdef _KERNEL
#else
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#endif
#include "ip_compat.h"
#include "ip_fil.h"
#include "radix.h"
int max_keylen = 16;
struct radix_mask *rn_mkfreelist;
struct radix_node_head *mask_rnhead;
static char *addmask_key;
static int rn_lexobetter __P((void *, void *));
struct radix_mask *));
/*
* The data structure for the keys is a radix tree with one way
* branching removed. The index rn_b 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_b - 1.
* (We say the index of n is rn_b.)
*
* There is at least one descendant which has a one bit at position rn_b,
* 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_b,
* and m is a normal mask, then the route applies to every descendant of n.
* If the index(m) < rn_b, 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.
*/
struct radix_node *
void *v_arg;
struct radix_node *head;
{
struct radix_node *x;
caddr_t v;
x = x->rn_r;
else
x = x->rn_l;
}
return (x);
}
struct radix_node *
struct radix_node *head;
{
struct radix_node *x;
x = x->rn_r;
else
x = x->rn_l;
}
return x;
}
int
{
int masks_are_equal = 1;
if (longer > 0)
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))
if (*m++)
return 1;
return (!masks_are_equal);
}
struct radix_node *
struct radix_node_head *head;
{
struct radix_node *x;
if (m_arg) {
return (0);
}
if (x && netmask) {
x = x->rn_dupedkey;
}
return x;
}
static int
char *trial;
struct radix_node *leaf;
int skip;
{
char *cplim;
if (cp3 == 0)
else
return 0;
return 1;
}
struct radix_node *
void *v_arg;
struct radix_node_head *head;
{
/*
* Open code rn_search(v, top) to avoid overhead of extra
* subroutine call.
*/
for (; t->rn_b >= 0; ) {
t = t->rn_r;
else
t = t->rn_l;
}
/*
* 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)
goto on1;
/*
* This extra grot is in case we are explicitly asked
* to look up the default. Ugh!
*/
t = t->rn_dupedkey;
return t;
on1:
b--;
matched_off = cp - v;
b += matched_off << 3;
rn_b = -1 - b;
/*
* If there is a host route in a duped-key chain, it will be first.
*/
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) {
return t;
} else if (rn_satisfies_leaf(v, t, matched_off))
return t;
t = saved_t;
/* start searching up the tree */
do {
struct radix_mask *m;
t = t->rn_p;
m = t->rn_mklist;
if (m) {
/*
* 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".
*/
do {
if (m->rm_flags & RNF_NORMAL) {
return (m->rm_leaf);
} else {
x = rn_search_m(v, t, m->rm_mask);
x = x->rn_dupedkey;
if (x && rn_satisfies_leaf(v, x, off))
return x;
}
m = m->rm_mklist;
} while (m);
}
} while (t != top);
return 0;
}
#ifdef RN_DEBUG
int rn_nodenum;
struct radix_node *rn_clist;
int rn_saveinfo;
int rn_debug = 1;
#endif
struct radix_node *
rn_newpair(v, b, nodes)
void *v;
int b;
{
#ifdef RN_DEBUG
#endif
return t;
}
struct radix_node *
void *v_arg;
struct radix_node_head *head;
int *dupentry;
{
int b;
struct radix_node *tt;
#ifdef RN_DEBUG
if (rn_debug)
#endif
/*
* Find first bit at which v and t->rn_key differ
*/
{
int cmp_res;
goto on1;
*dupentry = 1;
return t;
on1:
*dupentry = 0;
cmp_res >>= 1;
}
{
struct radix_node *p, *x = top;
cp = v;
do {
p = x;
x = x->rn_r;
else x = x->rn_l;
} while (b > (unsigned) x->rn_b); /* x->rn_b < b && x->rn_b >= 0 */
#ifdef RN_DEBUG
if (rn_debug)
#endif
p->rn_l = t;
else
p->rn_r = t;
t->rn_r = x;
} else {
}
#ifdef RN_DEBUG
if (rn_debug)
#endif
}
return (tt);
}
struct radix_node *
void *n_arg;
{
struct radix_node *x;
int b = 0, mlen, j;
struct radix_node *saved_x;
static int last_zeroed = 0;
#ifdef RN_DEBUG
if (rn_debug)
#endif
mlen = max_keylen;
if (skip == 0)
skip = 1;
return (mask_rnhead->rnh_nodes);
if (skip > 1)
/*
* Trim trailing zeroes.
*/
cp--;
if (m0 >= last_zeroed)
last_zeroed = mlen;
return (mask_rnhead->rnh_nodes);
}
if (m0 < last_zeroed)
x = 0;
if (x || search)
return (x);
if ((saved_x = x) == 0)
return (0);
if (maskduplicated) {
#if 0
#endif
return (x);
}
/*
* Calculate index of mask, and check for normalcy.
*/
cp++;
b++;
isnormal = 0;
}
x->rn_b = -1 - b;
if (isnormal)
x->rn_flags |= RNF_NORMAL;
return (x);
}
static int /* XXX: arbitrary ordering for non-contiguous masks */
{
return 1; /* not really, but need to check longer one first */
return 1;
return 0;
}
static struct radix_mask *
struct radix_node *tt;
struct radix_mask *next;
{
struct radix_mask *m;
MKGet(m);
if (m == 0) {
#if 0
#endif
return (0);
}
Bzero(m, sizeof *m);
else
return m;
}
struct radix_node *
struct radix_node_head *head;
{
struct radix_node *t, *x = 0, *tt;
short b = 0, b_leaf = 0;
int keyduplicated;
struct radix_mask *m, **mp;
#ifdef RN_DEBUG
if (rn_debug)
#endif
/*
* 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) {
return (0);
b = -1 - x->rn_b;
}
/*
* Deal with duplicated keys: attach node to previous instance
*/
if (keyduplicated) {
return (0);
if (netmask == 0 ||
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.
*
* We also reverse, or doubly link the list through the
* parent pointer.
*/
struct radix_node *xx = x;
/* link in at head of list */
} else {
t->rn_dupedkey = tt;
if (tt->rn_dupedkey)
}
#ifdef RN_DEBUG
#endif
}
/*
* Put mask in tree.
*/
if (netmask) {
}
if (keyduplicated)
goto on2;
/* Promote general routes from below */
if (x->rn_b < 0) {
*mp = m = rn_new_radix_mask(x, 0);
if (m)
}
} else if (x->rn_mklist) {
/*
* Skip over masks whose index is > that of new node
*/
break;
}
on2:
/* Add new route to highest possible ancestor's list */
return tt; /* can't lift at all */
do {
x = t;
t = t->rn_p;
/*
* 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.
*/
continue;
break;
if (m->rm_flags & RNF_NORMAL) {
#if 0
" mask not entered\n");
#endif
return tt;
}
} else
m->rm_refs++;
return tt;
}
break;
}
return tt;
}
struct radix_node *
void *v_arg, *netmask_arg;
struct radix_node_head *head;
{
struct radix_node *t, *p, *x, *tt;
v = v_arg;
x = head->rnh_treetop;
top = x;
if (tt == 0 ||
return (0);
/*
* Delete our route from mask lists.
*/
if (netmask) {
return (0);
return (0);
}
goto on1;
#if 0
#endif
return 0; /* dangling ref could cause disaster */
}
} else {
#if 0
#endif
goto on1;
}
if (--m->rm_refs >= 0)
goto on1;
}
if (b > t->rn_b)
goto on1; /* Wasn't lifted at all */
do {
x = t;
t = t->rn_p;
if (m == saved_m) {
MKFree(m);
break;
}
if (m == 0) {
#if 0
#endif
return (0); /* Dangling ref to us */
}
on1:
/*
* Eliminate us from tree
*/
return (0);
#ifdef RN_DEBUG
/* Get us out of the creation list */
#endif
if (dupedkey) {
/*
* Here, tt is the deletion target, and
* saved_tt is the head of the dupedkey chain.
*/
} else {
/* find node in front of tt on the chain */
p = p->rn_dupedkey;
if (p) {
if (tt->rn_dupedkey)
}
#if 0
else
#endif
}
t = tt + 1;
if (t->rn_flags & RNF_ACTIVE) {
#ifndef RN_DEBUG
*++x = *t; p = t->rn_p;
#else
#endif
}
goto out;
}
p = t->rn_p;
x->rn_p = p;
/*
* Demote routes attached to us.
*/
if (t->rn_mklist) {
if (x->rn_b >= 0) {
} 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) {
x->rn_mklist = 0;
if (--(m->rm_refs) < 0)
MKFree(m);
m = mm;
}
#if 0
if (m)
"rn_delete: Orphaned Mask", m, x);
#endif
}
}
/*
* We may be holding an active internal node in the tree.
*/
x = tt + 1;
if (t != x) {
#ifndef RN_DEBUG
*t = *x;
#else
#endif
p = x->rn_p;
}
out:
return (tt);
}
int
rn_walktree(h, f, w)
struct radix_node_head *h;
int (*f) __P((struct radix_node *, void *));
void *w;
{
int error;
/*
* This gets complicated because we may delete the node
* while applying the function f to it, so we need to calculate
* the successor node in advance.
*/
/* First time through node, go left */
for (;;) {
/* If at right child go back up, otherwise, go right */
/* Find the next *leaf* since next node might vanish, too */
/* Process leaves */
return (error);
}
return (0);
}
/* NOTREACHED */
}
int
void **head;
int off;
{
struct radix_node_head *rnh;
if (*head)
return (1);
if (rnh == 0)
return (0);
}
int
struct radix_node_head *rnh;
int off;
{
t->rn_p = t;
rnh->rnh_treetop = t;
return (1);
}
void
rn_init()
{
if (max_keylen == 0) {
#if 0
"rn_init: radix functions require max_keylen be set\n");
#endif
return;
}
}
panic("rn_init");
*cp++ = -1;
if (rn_inithead((void **)&mask_rnhead, 0) == 0)
panic("rn_init 2");
}
static int
rn_freenode(struct radix_node *n, void *p)
{
struct radix_node_head *rnh = p;
struct radix_node *d;
if (d != NULL) {
}
return 0;
}
void
struct radix_node_head *rnh;
{
}
void
rn_fini()
{
struct radix_mask *m;
}
if (mask_rnhead != NULL) {
mask_rnhead = NULL;
}
while ((m = rn_mkfreelist) != NULL) {
rn_mkfreelist = m->rm_mklist;
KFREE(m);
}
}
#ifdef USE_MAIN
typedef struct myst {
} myst_t;
int
{
struct radix_node_head *rnh;
struct radix_node *rn;
rn_init();
}
}
return 0;
}
void
{
}
#endif
#ifndef _KERNEL
void
{
abort();
}
#endif