freebsd-dev/sys/net/radix.c
Pedro F. Giffuni 51369649b0 sys: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:43:44 +00:00

1214 lines
31 KiB
C

/*-
* 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/rwlock.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/syslog.h>
#include <net/radix.h>
#include "opt_mpath.h"
#ifdef RADIX_MPATH
#include <net/radix_mpath.h>
#endif
#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(void *, struct radix_node *),
*rn_search_m(void *, struct radix_node *, void *);
static struct radix_node *rn_addmask(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(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);
/*
* 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(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);
}
/*
* Same as above, but with an additional mask.
* XXX note this function is used only once.
*/
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 + 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(void *v_arg, 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(char *trial, struct radix_node *leaf, int skip)
{
char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask;
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(void *v_arg, struct radix_head *head)
{
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 = 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);
}
#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;
int 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);
}
struct radix_node *
rn_addmask(void *n_arg, struct radix_mask_head *maskhead, int search, int skip)
{
unsigned char *netmask = n_arg;
unsigned char *cp, *cplim;
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))
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 (!CONTIG(*cp) || 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 (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, void *n_arg, struct radix_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) {
x = rn_addmask(netmask, 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) {
#ifdef RADIX_MPATH
/* permit multipath, if enabled for the family */
if (rn_mpath_capable(head) && netmask == tt->rn_mask) {
/*
* go down to the end of multipaths, so that
* new entry goes into the end of rn_dupedkey
* chain.
*/
do {
t = tt;
tt = tt->rn_dupedkey;
} while (tt && t->rn_mask == tt->rn_mask);
break;
}
#endif
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) {
#if !defined(RADIX_MPATH)
log(LOG_ERR,
"Non-unique normal route, mask not entered\n");
#endif
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_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 = 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);
}