/* radix.c - common routines for routing engine *//* Copyright 1990 - 2001 Wind River Systems, Inc. */#include "copyright_wrs.h"/* * 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	8.5 (Berkeley) 5/19/95 *//*modification history--------------------01d,05nov01,vvv  fixed compilation warning01c,12oct01,rae  merge from truestack ver 01f, base 01b01b,02jul97,vin  fixed warnings.01a,03mar96,vin  created from BSD4.4lite2.*//* * Routines to build and maintain radix trees for routing lookups. */#include "vxWorks.h"#include "stdlib.h"#include "logLib.h"#include "string.h"#include "net/domain.h"#include "net/systm.h"#include "net/radix.h"#ifdef WV_INSTRUMENTATION#ifdef INCLUDE_WVNET#include "wvNetLib.h"#endif#endif#ifdef VIRTUAL_STACK#include "netinet/vsLib.h"#elseint	max_keylen;struct radix_mask *rn_mkfreelist;struct radix_node_head *mask_rnhead;static char *addmask_key;static char *rn_zeros, *rn_ones;#endif#ifdef WV_INSTRUMENTATION#ifdef INCLUDE_WVNET    /* Set common fields of event identifiers for this module. */LOCAL UCHAR wvNetModuleId = WV_NET_RADIX_MODULE;   /* Value for radix.c */LOCAL UCHAR wvNetLocalFilter = WV_NET_NONE;     /* Available event filter */LOCAL ULONG wvNetEventId;       /* Event identifier: see wvNetLib.h */#endif    /* INCLUDE_WVNET */#endifstatic char normal_chars[] = {0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, -1};#define rn_masktop (mask_rnhead->rnh_treetop)#undef Bcmp#define Bcmp(a, b, l) (l == 0 ? 0 : bcmp((caddr_t)(a), (caddr_t)(b), (u_long)l))/* * 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 *rn_search(v_arg, head)	void *v_arg;	struct radix_node *head;{	register struct radix_node *x;	register caddr_t v;	for (x = head, v = v_arg; x->rn_b >= 0;) {		if (x->rn_bmask & v[x->rn_off])			x = x->rn_r;		else			x = x->rn_l;	}	return (x);}struct radix_node *rn_search_m(v_arg, head, m_arg)	struct radix_node *head;	void *v_arg, *m_arg;{	register struct radix_node *x;	register caddr_t v = v_arg, m = m_arg;	for (x = head; x->rn_b >= 0;) {		if ((x->rn_bmask & m[x->rn_off]) &&		    (x->rn_bmask & v[x->rn_off]))			x = x->rn_r;		else			x = x->rn_l;	}	return x;}intrn_refines(m_arg, n_arg)	void *m_arg, *n_arg;{	register caddr_t m = m_arg, n = n_arg;	register 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(v_arg, m_arg, head)	void *v_arg, *m_arg;	struct radix_node_head *head;{	register struct radix_node *x;	caddr_t netmask = 0;	if (m_arg) {		if ((x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_off)) == 0)			return (0);		netmask = x->rn_key;	}	x = rn_match(v_arg, head);	if (x && netmask) {		while (x && x->rn_mask != netmask)			x = x->rn_dupedkey;	}	return x;}static intrn_satsifies_leaf(trial, leaf, skip)	char *trial;	register struct radix_node *leaf;	int skip;{	register 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 1;}struct radix_node *rn_match(v_arg, head)	void *v_arg;	struct radix_node_head *head;{	caddr_t v = v_arg;	register struct radix_node *t = head->rnh_treetop, *x;	register caddr_t cp = v, cp2;	caddr_t cplim;	struct radix_node *saved_t, *top = t;	int off = t->rn_off, vlen = *(u_char *)cp, matched_off;	register int test, b, rn_b;	/*	 * Open code rn_search(v, top) to avoid overhead of extra	 * subroutine call.	 */	for (; t->rn_b >= 0; ) {		if (t->rn_bmask & cp[t->rn_off])			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)		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!	 */	if ((t->rn_flags & RNF_ROOT) && t->rn_dupedkey)		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_b = -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_b <= t->rn_b)				return t;		} else if (rn_satsifies_leaf(v, t, matched_off))				return t;	t = saved_t;	/* start searching up the tree */	do {		register 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) {					if (rn_b <= m->rm_b)						return (m->rm_leaf);				} else {					off = min(t->rn_off, 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_satsifies_leaf(v, x, off))						    return x;				}			m = m->rm_mklist;			} while (m);		}	} while (t != top);	return 0;}		#ifdef RN_DEBUGint	rn_nodenum;struct	radix_node *rn_clist;int	rn_saveinfo;int	rn_debug =  1;#endifstruct radix_node *rn_newpair(v, b, nodes)	void *v;	int b;	struct radix_node nodes[2];{	register struct radix_node *tt = nodes, *t = tt + 1;	t->rn_b = b; t->rn_bmask = 0x80 >> (b & 7);	t->rn_l = tt; t->rn_off = b >> 3;	tt->rn_b = -1; tt->rn_key = (caddr_t)v; tt->rn_p = t;	tt->rn_flags = t->rn_flags = RNF_ACTIVE;#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;}struct radix_node *rn_insert(v_arg, head, dupentry, nodes)	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_off, vlen = (int)*((u_char *)v);	register struct radix_node *t = rn_search(v_arg, top);	register caddr_t cp = v + head_off;	register int b;	struct radix_node *tt;    	/*	 * Find first bit at which v and t->rn_key differ	 */    {	register caddr_t cp2 = t->rn_key + head_off;	register 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;    }    {