/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* 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. 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
* $FreeBSD$
*/
/*
* Routines to build and maintain radix trees for routing lookups.
*/
#include <sys/param.h>
#ifdef _KERNEL
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/rmlock.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/syslog.h>
#include <net/radix.h>
#else /* !_KERNEL */
#include <stdio.h>
#include <strings.h>
#include <stdlib.h>
#define log(x, arg...) fprintf(stderr, ## arg)
#define panic(x) fprintf(stderr, "PANIC: %s", x), exit(1)
#define min(a, b) ((a) < (b) ? (a) : (b) )
#include <net/radix.h>
#endif /* !_KERNEL */
static struct radix_node
*rn_insert(void *, struct radix_head *, int *,
struct radix_node [2]),
*rn_newpair(void *, int, struct radix_node[2]),
*rn_search(const void *, struct radix_node *),
*rn_search_m(const void *, struct radix_node *, void *);
static struct radix_node *rn_addmask(const void *, struct radix_mask_head *, int,int);
static void rn_detachhead_internal(struct radix_head *);
#define RADIX_MAX_KEY_LEN 32
static char rn_zeros[RADIX_MAX_KEY_LEN];
static char rn_ones[RADIX_MAX_KEY_LEN] = {
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1,
};
static int rn_lexobetter(const void *m_arg, const void *n_arg);
static struct radix_mask *
rn_new_radix_mask(struct radix_node *tt,
struct radix_mask *next);
static int rn_satisfies_leaf(const char *trial, struct radix_node *leaf,
int skip);
/*
* 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.
*/
/*
* Most of the functions in this code assume that the key/mask arguments
* are sockaddr-like structures, where the first byte is an u_char
* 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.
* We cast the result to int as this is the dominant usage.
*/
#define LEN(x) ( (int) (*(const u_char *)(x)) )
/*
* XXX THIS NEEDS TO BE FIXED
* In the code, pointers to keys and masks are passed as either
* 'void *' (because callers use to pass pointers of various kinds), or
* 'caddr_t' (which is fine for pointer arithmetics, but not very
* clean when you dereference it to access data). Furthermore, caddr_t
* is really 'char *', while the natural type to operate on keys and
* masks would be 'u_char'. This mismatch require a lot of casts and
* intermediate variables to adapt types that clutter the code.
*/
/*
* Search a node in the tree matching the key.
*/
static struct radix_node *
rn_search(const void *v_arg, struct radix_node *head)
{
struct radix_node *x;
c_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);
}
/*
* Same as above, but with an additional mask.
* XXX note this function is used only once.
*/
static struct radix_node *
rn_search_m(const void *v_arg, struct radix_node *head, void *m_arg)
{
struct radix_node *x;
c_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(const void *m_arg, const void *n_arg)
{
c_caddr_t m = m_arg, n = n_arg;
c_caddr_t lim, lim2 = lim = n + LEN(n);
int longer = LEN(n++) - LEN(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);
}
/*
* Search for exact match in given @head.
* Assume host bits are cleared in @v_arg if @m_arg is not NULL
* Note that prefixes with /32 or /128 masks are treated differently
* from host routes.
*/
struct radix_node *
rn_lookup(const void *v_arg, const void *m_arg, struct radix_head *head)
{
struct radix_node *x;
caddr_t netmask;
if (m_arg != NULL) {
/*
* Most common case: search exact prefix/mask
*/
x = rn_addmask(m_arg, head->rnh_masks, 1,
head->rnh_treetop->rn_offset);
if (x == NULL)
return (NULL);
netmask = x->rn_key;
x = rn_match(v_arg, head);
while (x != NULL && x->rn_mask != netmask)
x = x->rn_dupedkey;
return (x);
}
/*
* Search for host address.
*/
if ((x = rn_match(v_arg, head)) == NULL)
return (NULL);
/* Check if found key is the same */
if (LEN(x->rn_key) != LEN(v_arg) || bcmp(x->rn_key, v_arg, LEN(v_arg)))
return (NULL);
/* Check if this is not host route */
if (x->rn_mask != NULL)
return (NULL);
return (x);
}
static int
rn_satisfies_leaf(const char *trial, struct radix_node *leaf, int skip)
{
const char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask;
const char *cplim;
int length = min(LEN(cp), LEN(cp2));
if (cp3 == NULL)
cp3 = rn_ones;
else
length = min(length, LEN(cp3));
cplim = cp + length; cp3 += skip; cp2 += skip;
for (cp += skip; cp < cplim; cp++, cp2++, cp3++)
if ((*cp ^ *cp2) & *cp3)
return (0);
return (1);
}
/*
* Search for longest-prefix match in given @head
*/
struct radix_node *
rn_match(const void *v_arg, struct radix_head *head)
{
c_caddr_t v = v_arg;
struct radix_node *t = head->rnh_treetop, *x;
c_caddr_t cp = v, cp2;
c_caddr_t cplim;
struct radix_node *saved_t, *top = t;
int off = t->rn_offset, vlen = LEN(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;
return (t);
on1:
test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */
for (b = 7; (test >>= 1) > 0;)
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.
*/
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)
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_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)
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))
return (x);
}
m = m->rm_mklist;
}
} while (t != top);
return (0);
}
/*
* Returns the next (wider) prefix for the key defined by @rn
* if exists.
*/
struct radix_node *
rn_nextprefix(struct radix_node *rn)
{
for (rn = rn->rn_dupedkey; rn != NULL; rn = rn->rn_dupedkey) {
if (!(rn->rn_flags & RNF_ROOT))
return (rn);
}
return (NULL);
}
#ifdef RN_DEBUG
int rn_nodenum;
struct radix_node *rn_clist;
int rn_saveinfo;
int rn_debug = 1;
#endif
/*
* 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.
* (XXX some fields are left unset, see the '#if 0' section).
* The function returns a pointer to the parent node.
*/
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;
#if 0 /* XXX perhaps we should fill these fields as well. */
t->rn_parent = t->rn_right = NULL;
tt->rn_mask = NULL;
tt->rn_dupedkey = NULL;
tt->rn_bmask = 0;
#endif
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 = 0;
#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_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 = LEN(v);
struct radix_node *t = rn_search(v_arg, top);
caddr_t cp = v + head_off;
unsigned b;
struct radix_node *p, *tt, *x;
/*
* 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;
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);
}
static struct radix_node *
rn_addmask(const void *n_arg, struct radix_mask_head *maskhead, int search, int skip)
{
const unsigned char *netmask = n_arg;
const unsigned char *c, *clim;
unsigned char *cp;
struct radix_node *x;
int b = 0, mlen, j;
int maskduplicated, isnormal;
struct radix_node *saved_x;
unsigned char addmask_key[RADIX_MAX_KEY_LEN];
if ((mlen = LEN(netmask)) > RADIX_MAX_KEY_LEN)
mlen = RADIX_MAX_KEY_LEN;
if (skip == 0)
skip = 1;
if (mlen <= skip)
return (maskhead->mask_nodes);
bzero(addmask_key, RADIX_MAX_KEY_LEN);
if (skip > 1)
bcopy(rn_ones + 1, addmask_key + 1, skip - 1);
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)
return (maskhead->mask_nodes);
*addmask_key = mlen;
x = rn_search(addmask_key, maskhead->head.rnh_treetop);
if (bcmp(addmask_key, x->rn_key, mlen) != 0)
x = NULL;
if (x || search)
return (x);
R_Zalloc(x, struct radix_node *, RADIX_MAX_KEY_LEN + 2 * sizeof (*x));
if ((saved_x = x) == NULL)
return (0);
netmask = cp = (unsigned char *)(x + 2);
bcopy(addmask_key, cp, mlen);
x = rn_insert(cp, &maskhead->head, &maskduplicated, x);
if (maskduplicated) {
log(LOG_ERR, "rn_addmask: mask impossibly already in tree");
R_Free(saved_x);
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 bits should be contiguous, otherwise we have got
* a non-contiguous mask.
*/
#define CONTIG(_c) (((~(_c) + 1) & (_c)) == (unsigned char)(~(_c) + 1))
clim = netmask + mlen;
isnormal = 1;
for (c = netmask + skip; (c < clim) && *(const u_char *)c == 0xff;)
c++;
if (c != clim) {
for (j = 0x80; (j & *c) != 0; j >>= 1)
b++;
if (!CONTIG(*c) || c != (clim - 1))
isnormal = 0;
}
b += (c - 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(const void *m_arg, const void *n_arg)
{
const u_char *mp = m_arg, *np = n_arg, *lim;
if (LEN(mp) > LEN(np))
return (1); /* not really, but need to check longer one first */
if (LEN(mp) == LEN(np))
for (lim = mp + LEN(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;
R_Malloc(m, struct radix_mask *, sizeof (struct radix_mask));
if (m == NULL) {
log(LOG_ERR, "Failed to allocate route mask\n");
return (0);
}
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, const void *n_arg, struct radix_head *head,
struct radix_node treenodes[2])
{
caddr_t v = (caddr_t)v_arg, netmask = NULL;
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 (n_arg) {
x = rn_addmask(n_arg, head->rnh_masks, 0, top->rn_offset);
if (x == NULL)
return (0);
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 (0);
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.
*
* We also reverse, or doubly link the list through the
* parent pointer.
*/
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;
}
/*
* 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, 0);
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\n");
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(const void *v_arg, const void *netmask_arg, struct radix_head *head)
{
struct radix_node *t, *p, *x, *tt;
struct radix_mask *m, *saved_m, **mp;
struct radix_node *dupedkey, *saved_tt, *top;
c_caddr_t v;
c_caddr_t 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 = LEN(v);
saved_tt = tt;
top = x;
if (tt == NULL ||
bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off))
return (0);
/*
* Delete our route from mask lists.
*/
if (netmask) {
x = rn_addmask(netmask, head->rnh_masks, 1, head_off);
if (x == NULL)
return (0);
netmask = x->rn_key;
while (tt->rn_mask != netmask)
if ((tt = tt->rn_dupedkey) == NULL)
return (0);
}
if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == NULL)
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 (0); /* 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;
R_Free(m);
break;
}
if (m == NULL) {
log(LOG_ERR, "rn_delete: couldn't find our annotation\n");
if (tt->rn_flags & RNF_NORMAL)
return (0); /* Dangling ref to us */
}
on1:
/*
* Eliminate us from tree
*/
if (tt->rn_flags & RNF_ROOT)
return (0);
#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) {
/*
* Here, 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 = 0;
if (--(m->rm_refs) < 0)
R_Free(m);
m = mm;
}
if (m)
log(LOG_ERR,
"rn_delete: Orphaned Mask %p at %p\n",
m, 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.
*/
int
rn_walktree_from(struct radix_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 = NULL; /* shut up gcc */
int stopping = 0;
int lastb;
KASSERT(m != NULL, ("%s: mask needs to be specified", __func__));
/*
* rn_search_m is sort-of-open-coded here. We cannot use the
* function because we need to keep track of the last node seen.
*/
/* printf("about to search\n"); */
for (rn = h->rnh_treetop; rn->rn_bit >= 0; ) {
last = rn;
/* printf("rn_bit %d, rn_bmask %x, xm[rn_offset] %x\n",
rn->rn_bit, rn->rn_bmask, xm[rn->rn_offset]); */
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;
}
}
/* printf("done searching\n"); */
/*
* 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 leaf.
*/
if (rn->rn_bit >= 0)
rn = last;
lastb = last->rn_bit;
/* printf("rn %p, lastb %d\n", rn, lastb);*/
/*
* 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.
*/
while (rn->rn_bit >= 0)
rn = rn->rn_left;
while (!stopping) {
/* printf("node %p (%d)\n", rn, rn->rn_bit); */
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;
/* printf("up too far\n"); */
/*
* 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!
*/
}
}
/*
* 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;
/* Find the next *leaf* since next node might vanish, too */
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;
/* printf("leaf %p\n", rn); */
if (!(rn->rn_flags & RNF_ROOT)
&& (error = (*f)(rn, w)))
return (error);
}
rn = next;
if (rn->rn_flags & RNF_ROOT) {
/* printf("root, stopping"); */
stopping = 1;
}
}
return (0);
}
int
rn_walktree(struct radix_head *h, walktree_f_t *f, void *w)
{
int error;
struct radix_node *base, *next;
struct radix_node *rn = h->rnh_treetop;
/*
* 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 */
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* since next node might vanish, too */
for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;)
rn = rn->rn_left;
next = rn;
/* Process leaves */
while ((rn = base)) {
base = rn->rn_dupedkey;
if (!(rn->rn_flags & RNF_ROOT)
&& (error = (*f)(rn, w)))
return (error);
}
rn = next;
if (rn->rn_flags & RNF_ROOT)
return (0);
}
/* NOTREACHED */
}
/*
* Initialize an empty tree. This has 3 nodes, which are passed
* via base_nodes (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'.
*/
void
rn_inithead_internal(struct radix_head *rh, struct radix_node *base_nodes, int off)
{
struct radix_node *t, *tt, *ttt;
t = rn_newpair(rn_zeros, off, base_nodes);
ttt = base_nodes + 2;
t->rn_right = ttt;
t->rn_parent = t;
tt = t->rn_left; /* ... which in turn is base_nodes */
tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE;
tt->rn_bit = -1 - off;
*ttt = *tt;
ttt->rn_key = rn_ones;
rh->rnh_treetop = t;
}
static void
rn_detachhead_internal(struct radix_head *head)
{
KASSERT((head != NULL),
("%s: head already freed", __func__));
/* Free <left,root,right> nodes. */
R_Free(head);
}
/* Functions used by 'struct radix_node_head' users */
int
rn_inithead(void **head, int off)
{
struct radix_node_head *rnh;
struct radix_mask_head *rmh;
rnh = *head;
rmh = NULL;
if (*head != NULL)
return (1);
R_Zalloc(rnh, struct radix_node_head *, sizeof (*rnh));
R_Zalloc(rmh, struct radix_mask_head *, sizeof (*rmh));
if (rnh == NULL || rmh == NULL) {
if (rnh != NULL)
R_Free(rnh);
if (rmh != NULL)
R_Free(rmh);
return (0);
}
/* Init trees */
rn_inithead_internal(&rnh->rh, rnh->rnh_nodes, off);
rn_inithead_internal(&rmh->head, rmh->mask_nodes, 0);
*head = rnh;
rnh->rh.rnh_masks = rmh;
/* Finally, set base callbacks */
rnh->rnh_addaddr = rn_addroute;
rnh->rnh_deladdr = rn_delete;
rnh->rnh_matchaddr = rn_match;
rnh->rnh_lookup = rn_lookup;
rnh->rnh_walktree = rn_walktree;
rnh->rnh_walktree_from = rn_walktree_from;
return (1);
}
static int
rn_freeentry(struct radix_node *rn, void *arg)
{
struct radix_head * const rnh = arg;
struct radix_node *x;
x = (struct radix_node *)rn_delete(rn + 2, NULL, rnh);
if (x != NULL)
R_Free(x);
return (0);
}
int
rn_detachhead(void **head)
{
struct radix_node_head *rnh;
KASSERT((head != NULL && *head != NULL),
("%s: head already freed", __func__));
rnh = (struct radix_node_head *)(*head);
rn_walktree(&rnh->rh.rnh_masks->head, rn_freeentry, rnh->rh.rnh_masks);
rn_detachhead_internal(&rnh->rh.rnh_masks->head);
rn_detachhead_internal(&rnh->rh);
*head = NULL;
return (1);
}
