/*
 * Copyright (c) 1985, 1993
 *    The Regents of the University of California.  All rights reserved.
 *
 * Portions copyright (c) 1999, 2000
 * Intel Corporation.
 * 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, Intel Corporation, and its contributors.
 *
 * 4. Neither the name of University, Intel Corporation, or their respective
 *    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, INTEL CORPORATION 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,
 * INTEL CORPORATION 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.
 *
 */

/*
 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies, and that
 * the name of Digital Equipment Corporation not be used in advertising or
 * publicity pertaining to distribution of the document or software without
 * specific, written prior permission.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

/*
 * Portions Copyright (c) 1996 by Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)res_comp.c  8.1 (Berkeley) 6/4/93";
static char orig_rcsid[] = "From: Id: res_comp.c,v 8.11 1997/05/21 19:31:04 halley Exp $";
static char rcsid[] = "$Id: res_comp.c $";
#endif /* LIBC_SCCS and not lint */

#include <sys/types.h>
#include <sys/param.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <ctype.h>
#include <resolv.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

#define BIND_4_COMPAT

/*
 * 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
dn_expand(const u_char *msg, const u_char *eom, const u_char *src,
      char *dst, int dstsiz)
{
    int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz);

    if (n > 0 && dst[0] == '.')
        dst[0] = '\0';
    return (n);
}

/*
 * Pack domain name 'exp_dn' in presentation form into 'comp_dn'.
 * Return the size of the compressed name or -1.
 * 'length' is the size of the array pointed to by 'comp_dn'.
 */
int
dn_comp(const char *src, u_char *dst, int dstsiz,
    u_char **dnptrs, u_char **lastdnptr)
{
    return (ns_name_compress(src, dst, (size_t)dstsiz,
                 (const u_char **)dnptrs,
                 (const u_char **)lastdnptr));
}

/*
 * Skip over a compressed domain name. Return the size or -1.
 */
int
dn_skipname(const u_char *ptr, const u_char *eom) {
    const u_char *saveptr = ptr;

    if (ns_name_skip(&ptr, eom) == -1)
        return (-1);
    return ((int)(ptr - saveptr));
}

/*
 * Verify that a domain name uses an acceptable character set.
 */

/*
 * Note the conspicuous absence of ctype macros in these definitions.  On
 * non-ASCII hosts, we can't depend on string literals or ctype macros to
 * tell us anything about network-format data.  The rest of the BIND system
 * is not careful about this, but for some reason, we're doing it right here.
 */
#define PERIOD 0x2e
#define hyphenchar(c) ((c) == 0x2d)
#define bslashchar(c) ((c) == 0x5c)
#define periodchar(c) ((c) == PERIOD)
#define asterchar(c) ((c) == 0x2a)
#define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \
           || ((c) >= 0x61 && (c) <= 0x7a))
#define digitchar(c) ((c) >= 0x30 && (c) <= 0x39)

#define borderchar(c) (alphachar(c) || digitchar(c))
#define middlechar(c) (borderchar(c) || hyphenchar(c))
#define domainchar(c) ((c) > 0x20 && (c) < 0x7f)

int
res_hnok(
    const char *dn
    )
{
    int ppch = '\0', pch = PERIOD, ch = *dn++;

    while (ch != '\0') {
        int nch = *dn++;

        if (periodchar(ch)) {
            (void)NULL;
        } else if (periodchar(pch)) {
            if (!borderchar(ch))
                return (0);
        } else if (periodchar(nch) || nch == '\0') {
            if (!borderchar(ch))
                return (0);
        } else {
            if (!middlechar(ch))
                return (0);
        }
        ppch = pch, pch = ch, ch = nch;
    }
    return (1);
}

/*
 * hostname-like (A, MX, WKS) owners can have "*" as their first label
 * but must otherwise be as a host name.
 */
int
res_ownok(
    const char *dn
    )
{
    if (asterchar(dn[0])) {
        if (periodchar(dn[1]))
            return (res_hnok(dn+2));
        if (dn[1] == '\0')
            return (1);
    }
    return (res_hnok(dn));
}

/*
 * SOA RNAMEs and RP RNAMEs can have any printable character in their first
 * label, but the rest of the name has to look like a host name.
 */
int
res_mailok(
    const char *dn
    )
{
    int ch, escaped = 0;

    /* "." is a valid missing representation */
    if (*dn == '\0')
        return (1);

    /* otherwise <label>.<hostname> */
    while ((ch = *dn++) != '\0') {
        if (!domainchar(ch))
            return (0);
        if (!escaped && periodchar(ch))
            break;
        if (escaped)
            escaped = 0;
        else if (bslashchar(ch))
            escaped = 1;
    }
    if (periodchar(ch))
        return (res_hnok(dn));
    return (0);
}

/*
 * This function is quite liberal, since RFC 1034's character sets are only
 * recommendations.
 */
int
res_dnok(
    const char *dn
    )
{
    int ch;

    while ((ch = *dn++) != '\0')
        if (!domainchar(ch))
            return (0);
    return (1);
}

#ifdef BIND_4_COMPAT
/*
 * This module must export the following externally-visible symbols:
 *    ___putlong
 *    ___putshort
 *    __getlong
 *    __getshort
 * Note that one _ comes from C and the others come from us.
 */
void __putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); }
void __putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); }
u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); }
u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); }
#endif /*BIND_4_COMPAT*/
