radix.c revision 40cdc2e8babc6bb3ab847f6a129fc9eb76c5f4d5
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*
* 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
* 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 8.5 (Berkeley) 5/19/95
* imp Exp $
*/
/*
* Routines to build and maintain radix trees for routing lookups.
*/
#ifndef _RADIX_H_
#ifdef _KERNEL
#else
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <syslog.h>
#include <strings.h>
#endif /* _KERNEL */
#endif
#ifndef _KERNEL
void
{
abort();
}
#endif /* _KERNEL */
static struct radix_node
*rn_insert(void *, struct radix_node_head *, int *,
struct radix_node [2]),
*rn_search(void *, struct radix_node *),
*rn_search_m(void *, struct radix_node *, void *),
*rn_lookup(void *, void *, struct radix_node_head *),
*rn_match(void *, struct radix_node_head *),
void *),
*rn_addmask(void *, int, int),
*rn_addroute(void *, void *, struct radix_node_head *,
struct radix_node [2]),
*rn_delete(void *, void *, struct radix_node_head *);
static boolean_t rn_refines(void *, void *);
/*
* IPF also uses PATRICIA tree to manage ippools. IPF stores its own structure
* addrfamily_t. sizeof (addrfamily_t) == 24.
*/
#define MAX_KEYLEN 24
static int max_keylen = MAX_KEYLEN;
#ifdef _KERNEL
static struct kmem_cache *radix_node_cache;
#else
#endif /* _KERNEL */
static struct radix_mask *rn_mkfreelist;
static struct radix_node_head *mask_rnhead;
/*
* Work area -- the following point to 2 buffers of size max_keylen,
* allocated in this order in a block of memory malloc'ed by rn_init.
* A third buffer of size MAX_KEYLEN is allocated from the stack.
*/
static struct radix_mask *
struct radix_mask *next);
static boolean_t
/*
* 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 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.
*/
/*
* are sockaddr-like structures, where the first byte is an uchar_t
* indicating the size of the entire structure.
*
* To make the assumption more explicit, we use the LEN() macro to access
* this field. It is safe to pass an expression with side effects
* to LEN() as the argument is evaluated only once.
*/
/*
* Search a node in the tree matching the key.
*/
static struct radix_node *
void *v_arg;
struct radix_node *head;
{
struct radix_node *x;
caddr_t v;
x = x->rn_right;
else
x = x->rn_left;
}
return (x);
}
/*
* Same as above, but with an additional mask.
*/
static struct radix_node *
struct radix_node *head;
{
struct radix_node *x;
x = x->rn_right;
else
x = x->rn_left;
}
return (x);
}
/*
* Returns true if there are no bits set in n_arg that are zero in
* m_arg and the masks aren't equal. In other words, it returns true
* when m_arg is a finer-granularity netmask -- it represents a subset
* of the destinations implied by n_arg.
*/
static boolean_t
{
if (longer > 0)
while (n < lim) {
if (*n & ~(*m))
return (0);
if (*n++ != *m++)
}
while (n < lim2)
if (*n++)
return (B_FALSE);
if (masks_are_equal && (longer < 0))
if (*m++)
return (B_TRUE);
return (!masks_are_equal);
}
static struct radix_node *
struct radix_node_head *head;
{
struct radix_node *x;
if (m_arg) {
if (x == NULL)
return (NULL);
}
if (x && 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.
* In addition, if a rn_leaf_fn is passed in, that is used to find
* a match on conditions defined by the caller of rn_match. This is
* used by the kernel ftable to match on IRE_MATCH_* conditions.
*/
static boolean_t
struct radix_node *leaf;
int skip;
void *rn_leaf_arg;
{
char *cplim;
if (cp3 == 0)
else
return (B_FALSE);
}
static struct radix_node *
void *v_arg;
struct radix_node_head *head;
{
}
static struct radix_node *
void *v_arg;
struct radix_node_head *head;
void *rn_leaf_arg;
{
/*
* Open code rn_search(v, top) to avoid overhead of extra
* subroutine call.
*/
for (; t->rn_bit >= 0; ) {
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)
goto keydiff;
/*
* 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.
*/
t = t->rn_dupedkey;
return (t);
} else {
/*
* Although we found an exact match on the key, rn_leaf_fn
* is looking for some other criteria as well. Continue
* looking as if the exact match failed.
*/
/* hit the top. have to give up */
return (NULL);
}
b = 0;
goto keeplooking;
}
b--;
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.
*/
t = t->rn_dupedkey;
for (; t != NULL; 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);
}
rn_leaf_arg)) {
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) {
rn_leaf_arg)) {
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,
rn_leaf_fn, rn_leaf_arg)) {
return (x);
}
}
m = m->rm_mklist;
}
} while (t != top);
return (0);
}
/*
* Whenever we add a new leaf to the tree, we also add a parent node,
* so we allocate them as an array of two elements: the first one must be
* the leaf (see RNTORT() in route.c), the second one is the parent.
* This routine initializes the relevant fields of the nodes, so that
* the leaf is the left child of the parent node, and both nodes have
* (almost) all all fields filled as appropriate.
* The function returns a pointer to the parent node.
*/
static struct radix_node *
rn_newpair(v, b, nodes)
void *v;
int b;
{
t->rn_bit = b;
t->rn_offset = b >> 3;
/*
* t->rn_parent, r->rn_right, tt->rn_mask, tt->rn_dupedkey
* and tt->rn_bmask must have been zeroed by caller.
*/
return (t);
}
static struct radix_node *
void *v_arg;
struct radix_node_head *head;
int *dupentry;
{
int b;
struct radix_node *tt;
/*
* 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_right;
else
x = x->rn_left;
} while (b > (unsigned)x->rn_bit);
/* x->rn_bit < b && x->rn_bit >= 0 */
p->rn_left = t;
else
p->rn_right = t;
x->rn_parent = t;
t->rn_parent = p;
t->rn_right = x;
} else {
t->rn_left = x;
}
}
return (tt);
}
static struct radix_node *
void *n_arg;
{
struct radix_node *x;
int b = 0, mlen, j;
struct radix_node *saved_x;
int last_zeroed = 0;
char addmask_key[MAX_KEYLEN];
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) {
#ifdef _KERNEL
#else
#endif /* _KERNEL */
return (x);
}
/*
* Calculate index of mask, and check for normalcy.
* First find the first byte with a 0 bit, then if there are
* more bits left (remember we already trimmed the trailing 0's),
* the pattern must be one of those in normal_chars[], or we have
* a non-contiguous mask.
*/
isnormal = 1;
cp++;
static uint8_t normal_chars[] = {
0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff};
b++;
isnormal = 0;
}
x->rn_bit = -1 - b;
if (isnormal)
x->rn_flags |= RNF_NORMAL;
return (x);
}
/* arbitrary ordering for non-contiguous masks */
static boolean_t
{
/* not really, but need to check longer one first */
return (B_TRUE);
return (B_TRUE);
return (B_FALSE);
}
static struct radix_mask *
struct radix_node *tt;
struct radix_mask *next;
{
struct radix_mask *m;
MKGet(m);
if (m == 0) {
#ifndef _KERNEL
#endif /* _KERNEL */
return (0);
}
bzero(m, sizeof (*m));
else
return (m);
}
static 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;
/*
* 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_bit;
}
/*
* Deal with duplicated keys: attach node to previous instance
*/
if (keyduplicated) {
return (0);
if (netmask == 0 ||
/* index (netmask) > node */
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 */
if (x->rn_left == t)
else
} else {
t->rn_dupedkey = tt;
/* Set rn_parent value for tt and tt->rn_dupedkey */
if (tt->rn_dupedkey)
}
}
/*
* Put mask in tree.
*/
if (netmask) {
}
if (keyduplicated)
goto key_exists;
x = t->rn_left;
else
x = t->rn_right;
/* Promote general routes from below */
if (x->rn_bit < 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;
}
/* Add new route to highest possible ancestor's list */
return (tt); /* can't lift at all */
do {
x = t;
t = t->rn_parent;
/*
* 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) {
#ifdef _KERNEL
"mask not entered\n");
#else
"mask not entered\n");
#endif /* _KERNEL */
return (tt);
}
} else
m->rm_refs++;
return (tt);
}
break;
}
return (tt);
}
static 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;
#ifdef _KERNEL
"rn_delete: inconsistent annotation\n");
#else
#endif /* _KERNEL */
return (0); /* dangling ref could cause disaster */
}
} else {
#ifdef _KERNEL
"rn_delete: inconsistent annotation 2\n");
#else
"rn_delete: inconsistent annotation 2\n");
#endif /* _KERNEL */
goto on1;
}
if (--m->rm_refs >= 0)
goto on1;
}
if (b > t->rn_bit)
goto on1; /* Wasn't lifted at all */
do {
x = t;
t = t->rn_parent;
if (m == saved_m) {
MKFree(m);
break;
}
if (m == 0) {
#ifdef _KERNEL
#else
#endif /* _KERNEL */
return (0); /* Dangling ref to us */
}
on1:
/*
* Eliminate us from tree
*/
return (0);
if (dupedkey) {
/*
* Here, tt is the deletion target and
* saved_tt is the head of the dupekey chain.
*/
/* remove from head of chain */
t->rn_left = x;
else
t->rn_right = x;
} else {
/* find node in front of tt on the chain */
p = p->rn_dupedkey;
if (p) {
/* parent */
} else
#ifdef _KERNEL
"rn_delete: couldn't find us\n");
#else
"rn_delete: couldn't find us\n");
#endif /* _KERNEL */
}
t = tt + 1;
if (t->rn_flags & RNF_ACTIVE) {
*++x = *t;
p = t->rn_parent;
if (p->rn_left == t)
p->rn_left = x;
else
p->rn_right = x;
}
goto out;
}
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) {
} 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 (m)
#ifdef _KERNEL
"rn_delete: Orphaned Mask %p at %p\n",
(void *)m, (void *)x);
#else
"rn_delete: Orphaned Mask %p at %p\n",
(void *)m, (void *)x);
#endif /* _KERNEL */
}
}
/*
* We may be holding an active internal node in the tree.
*/
x = tt + 1;
if (t != x) {
*t = *x;
p = x->rn_parent;
if (p->rn_left == x)
p->rn_left = t;
else
p->rn_right = t;
}
out:
return (tt);
}
/*
* Walk the radix tree; For the kernel routing table, we hold additional
* refs on the ire_bucket to ensure that the walk function f() does not
* run into trashed memory. The kernel routing table is identified by
* a rnh_treetop that has RNF_SUNW_FT set in the rn_flags.
* Note that all refs takein in rn_walktree are released before it returns,
* so that f() will need to take any additional references on memory
* to be passed back to the caller of rn_walktree.
*/
static int
rn_walktree(h, f, w)
struct radix_node_head *h;
walktree_f_t *f;
void *w;
{
}
static int
struct radix_node_head *h;
walktree_f_t *f;
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 */
}
if (is_mt)
for (;;) {
/* If at right child go back up, otherwise, go right */
}
/* Find the next *leaf* since next node might vanish, too */
}
/* Process leaves */
if (is_mt) {
}
return (error);
}
if (is_mt)
}
/*
* no ref to release, since we never take a ref
* on the root node- it can't be deleted.
*/
return (0);
}
}
/* NOTREACHED */
}
/*
* Allocate and initialize an empty tree. This has 3 nodes, which are
* part of the radix_node_head (in the order <left,root,right>) and are
* marked RNF_ROOT so they cannot be freed.
* The leaves have all-zero and all-one keys, with significant
* bits starting at 'off'.
* Return 1 on success, 0 on error.
*/
int
void **head;
int off;
{
struct radix_node_head *rnh;
if (*head)
return (1);
if (rnh == 0)
return (0);
#ifdef _KERNEL
#endif
t->rn_parent = t;
rnh->rnh_treetop = t;
return (1);
}
void
rn_init()
{
#ifdef _KERNEL
#endif /* _KERNEL */
*cp++ = -1;
if (rn_inithead((void **)(void *)&mask_rnhead, 0) == 0)
panic("rn_init: could not init mask_rnhead ");
}
int
rn_freenode(n, p)
struct radix_node *n;
void *p;
{
struct radix_node_head *rnh = p;
struct radix_node *d;
if (d != NULL) {
Free(d, radix_node_cache);
}
return (0);
}
void
struct radix_node_head *rnh;
{
#ifdef _KERNEL
#else
#endif /* _KERNEL */
}
void
rn_fini()
{
struct radix_mask *m;
#ifdef _KERNEL
#else
#endif
}
if (mask_rnhead != NULL) {
mask_rnhead = NULL;
}
while ((m = rn_mkfreelist) != NULL) {
rn_mkfreelist = m->rm_mklist;
}
}