glibc/resolv/res_comp.c

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/*
* Copyright (c) 1985, 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.
* 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.
*/
/*
* 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) 1996-1999 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 const char sccsid[] = "@(#)res_comp.c 8.1 (Berkeley) 6/4/93";
static const char rcsid[] = "$BINDId: res_comp.c,v 8.15 1999/10/13 16:39:39 vixie Exp $";
#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>
/*
* 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 (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 underscorechar(c) ((c) == 0x5f)
#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) || underscorechar(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); }
#ifndef __ultrix__
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 /*__ultrix__*/
#endif /*BIND_4_COMPAT*/
#include <shlib-compat.h>
#if SHLIB_COMPAT(libresolv, GLIBC_2_0, GLIBC_2_2)
# undef dn_expand
weak_alias (__dn_expand, dn_expand);
#endif