/* res_comp.c - expands and compresses domain names in a messge  *//* Copyright 1984-2001 Wind River Systems, Inc. */#include "copyright_wrs.h"/* * Copyright (c) 1985 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. *//*modification history--------------------01b,17sep01,vvv  fixed compilation warnings01a,13dec96,jag  Cleaned up and rename functions with the resolv prefix.  The                 man pages for these functions appear in resolvLib*/#include <resolvLib.h>#include <stdio.h>static int dn_find();/* * Expand compressed domain name 'comp_dn' to full domain name. * 'msg' is a pointer to the begining of the message, * 'eomorig' points to the first location after the message, * 'exp_dn' is a pointer to a buffer of size 'length' for the result. * Return size of compressed name or -1 if there was an error. */int resolvDNExpand(msg, eomorig, comp_dn, exp_dn, length)	const u_char *msg, *eomorig, *comp_dn;	u_char *exp_dn;	int length;{	register u_char *cp, *dn;	register int n, c;	u_char *eom;	int len = -1, checked = 0;	dn = exp_dn;	cp = (u_char *)comp_dn;	eom = exp_dn + length;	/*	 * fetch next label in domain name	 */	while ((n = *cp++)) {		/*		 * Check for indirection		 */		switch (n & INDIR_MASK) {		case 0:			if (dn != exp_dn) {				if (dn >= eom)					return (-1);				*dn++ = '.';			}			if (dn+n >= eom)				return (-1);			checked += n + 1;			while (--n >= 0) {				if ((c = *cp++) == '.') {					if (dn + n + 2 >= eom)						return (-1);					*dn++ = '\\';				}				*dn++ = c;				if (cp >= eomorig)	/* out of range */					return(-1);			}			break;		case INDIR_MASK:			if (len < 0)				len = cp - comp_dn + 1;			cp = (u_char *)msg + (((n & 0x3f) << 8) | (*cp & 0xff));			if (cp < msg || cp >= eomorig)	/* out of range */				return(-1);			checked += 2;			/*			 * Check for loops in the compressed name;			 * if we've looked at the whole message,			 * there must be a loop.			 */			if (checked >= eomorig - msg)				return (-1);			break;		default:			return (-1);			/* flag error */		}	}	*dn = '\0';	if (len < 0)		len = cp - comp_dn;	return (len);}/* * Compress domain name 'exp_dn' into 'comp_dn'. * Return the size of the compressed name or -1. * 'length' is the size of the array pointed to by 'comp_dn'. * 'dnptrs' is a list of pointers to previous compressed names. dnptrs[0] * is a pointer to the beginning of the message. The list ends with NULL. * 'lastdnptr' is a pointer to the end of the arrary pointed to * by 'dnptrs'. Side effect is to update the list of pointers for * labels inserted into the message as we compress the name. * If 'dnptr' is NULL, we don't try to compress names. If 'lastdnptr' * is NULL, we don't update the list. */int resolvDNComp(exp_dn, comp_dn, length, dnptrs, lastdnptr)	const u_char *exp_dn;	u_char *comp_dn;        int length;        u_char **dnptrs, **lastdnptr;{	register u_char *cp, *dn;	register int c, l;	u_char **cpp = NULL, **lpp = NULL, *sp, *eob;	u_char *msg;	dn = (u_char *)exp_dn;	cp = comp_dn;	eob = cp + length;	if (dnptrs != NULL) {		if ((msg = *dnptrs++) != NULL) {			for (cpp = dnptrs; *cpp != NULL; cpp++)				;			lpp = cpp;	/* end of list to search */		}	} else		msg = NULL;	for (c = *dn++; c != '\0'; ) {		/* look to see if we can use pointers */		if (msg != NULL) {			if ((l = dn_find(dn-1, msg, dnptrs, lpp)) >= 0) {				if (cp+1 >= eob)					return (-1);				*cp++ = (l >> 8) | INDIR_MASK;				*cp++ = l % 256;				return (cp - comp_dn);			}			/* not found, save it */			if (lastdnptr != NULL && cpp < lastdnptr-1) {				*cpp++ = cp;				*cpp = NULL;			}		}		sp = cp++;	/* save ptr to length byte */		do {			if (c == '.') {				c = *dn++;				break;			}			if (c == '\\') {				if ((c = *dn++) == '\0')					break;			}			if (cp >= eob) {				if (msg != NULL)					*lpp = NULL;				return (-1);			}			*cp++ = c;		} while ((c = *dn++) != '\0');		/* catch trailing '.'s but not '..' */		if ((l = cp - sp - 1) == 0 && c == '\0') {			cp--;			break;		}		if (l <= 0 || l > MAXLABEL) {			if (msg != NULL)				*lpp = NULL;			return (-1);		}		*sp = l;	}	if (cp >= eob) {		if (msg != NULL)			*lpp = NULL;		return (-1);	}	*cp++ = '\0';	return (cp - comp_dn);}/* * Skip over a compressed domain name. Return the size or -1. */int __dn_skipname(comp_dn, eom)	const u_char *comp_dn, *eom;{	register u_char *cp;	register int n;	cp = (u_char *)comp_dn;	while (cp < eom && (n = *cp++)) {		/*		 * check for indirection		 */		switch (n & INDIR_MASK) {		case 0:			/* normal case, n == len */			cp += n;			continue;		case INDIR_MASK:	/* indirection */			cp++;			break;		default:		/* illegal type */			return (-1);		}		break;	}	if (cp > eom)		return -1;	return (cp - comp_dn);}/* * Search for expanded name from a list of previously compressed names. * Return the offset from msg if found or -1. * dnptrs is the pointer to the first name on the list, * not the pointer to the start of the message. */static intdn_find(exp_dn, msg, dnptrs, lastdnptr)	u_char *exp_dn, *msg;	u_char **dnptrs, **lastdnptr;{	register u_char *dn, *cp, **cpp;	register int n;	u_char *sp;	for (cpp = dnptrs; cpp < lastdnptr; cpp++) {		dn = exp_dn;		sp = cp = *cpp;		while ((n = *cp++)) {			/*			 * check for indirection			 */			switch (n & INDIR_MASK) {			case 0:		/* normal case, n == len */				while (--n >= 0) {					if (*dn == '.')						goto next;					if (*dn == '\\')						dn++;					if (*dn++ != *cp++)						goto next;				}				if ((n = *dn++) == '\0' && *cp == '\0')					return (sp - msg);				if (n == '.')					continue;				goto next;			default:	/* illegal type */				return (-1);			case INDIR_MASK:	/* indirection */				cp = msg + (((n & 0x3f) << 8) | *cp);			}		}		if (*dn == '\0')			return (sp - msg);	next:	;	}	return (-1);}/* * Routines to insert/extract short/long's. Must account for byte * order and non-alignment problems. This code at least has the * advantage of being portable. * * used by sendmail. */u_short_getshort(msgp)	register u_char *msgp;{	register u_short u;	GETSHORT(u, msgp);	return (u);}uint32_t_getlong(msgp)	u_char *msgp;{	register uint32_t u;	GETLONG(u, msgp);	return (u);}void#ifdef __STDC____putshort(register uint16_t s, register u_char *msgp)#else__putshort(s, msgp)	register uint16_t s;	register u_char *msgp;#endif{	PUTSHORT(s, msgp);}void__putlong(l, msgp)	register uint32_t l;	register u_char *msgp;{	PUTLONG(l, msgp);}