c8d2fd6da8
chunks of res_comp.c and replacing it with chunks of bind-8.1.1's resolver code. (There are no interface changes though) The other parts are better bounds checking related.
923 lines
21 KiB
C
923 lines
21 KiB
C
/*
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* ++Copyright++ 1985, 1993
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* -
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* Copyright (c) 1985, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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* -
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* Portions Copyright (c) 1993 by Digital Equipment Corporation.
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies, and that
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* the name of Digital Equipment Corporation not be used in advertising or
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* publicity pertaining to distribution of the document or software without
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* specific, written prior permission.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
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* WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
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* CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
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* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
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* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
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* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
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* SOFTWARE.
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* -
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* --Copyright--
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*/
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#if defined(LIBC_SCCS) && !defined(lint)
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static char sccsid[] = "@(#)res_comp.c 8.1 (Berkeley) 6/4/93";
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static char orig_rcsid[] = "From: Id: res_comp.c,v 8.13 1998/04/07 04:24:06 vixie Exp $";
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static char rcsid[] = "$Id: res_comp.c,v 1.12 1997/06/27 08:22:02 peter Exp $";
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#endif /* LIBC_SCCS and not lint */
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#include <sys/types.h>
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#include <sys/param.h>
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#include <netinet/in.h>
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#include <arpa/nameser.h>
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#include <stdio.h>
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#include <resolv.h>
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#include <ctype.h>
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#include <errno.h>
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#include <unistd.h>
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#include <string.h>
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static int ns_name_ntop __P((const u_char *, char *, size_t));
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static int ns_name_pton __P((const char *, u_char *, size_t));
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static int ns_name_unpack __P((const u_char *, const u_char *,
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const u_char *, u_char *, size_t));
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static int ns_name_pack __P((const u_char *, u_char *, int,
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const u_char **, const u_char **));
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static int ns_name_uncompress __P((const u_char *, const u_char *,
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const u_char *, char *, size_t));
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static int ns_name_compress __P((const char *, u_char *, size_t,
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const u_char **, const u_char **));
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static int ns_name_skip __P((const u_char **, const u_char *));
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/*
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* Expand compressed domain name 'comp_dn' to full domain name.
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* 'msg' is a pointer to the begining of the message,
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* 'eomorig' points to the first location after the message,
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* 'exp_dn' is a pointer to a buffer of size 'length' for the result.
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* Return size of compressed name or -1 if there was an error.
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*/
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int
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dn_expand(const u_char *msg, const u_char *eom, const u_char *src,
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char *dst, int dstsiz)
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{
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int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz);
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if (n > 0 && dst[0] == '.')
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dst[0] = '\0';
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return (n);
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}
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/*
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* Pack domain name 'exp_dn' in presentation form into 'comp_dn'.
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* Return the size of the compressed name or -1.
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* 'length' is the size of the array pointed to by 'comp_dn'.
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*/
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int
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dn_comp(const char *src, u_char *dst, int dstsiz,
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u_char **dnptrs, u_char **lastdnptr)
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{
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return (ns_name_compress(src, dst, (size_t)dstsiz,
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(const u_char **)dnptrs,
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(const u_char **)lastdnptr));
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}
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/*
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* Skip over a compressed domain name. Return the size or -1.
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*/
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int
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__dn_skipname(const u_char *ptr, const u_char *eom) {
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const u_char *saveptr = ptr;
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if (ns_name_skip(&ptr, eom) == -1)
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return (-1);
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return (ptr - saveptr);
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}
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/*
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* Verify that a domain name uses an acceptable character set.
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*/
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/*
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* Note the conspicuous absence of ctype macros in these definitions. On
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* non-ASCII hosts, we can't depend on string literals or ctype macros to
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* tell us anything about network-format data. The rest of the BIND system
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* is not careful about this, but for some reason, we're doing it right here.
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*/
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#define PERIOD 0x2e
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#define hyphenchar(c) ((c) == 0x2d)
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#define bslashchar(c) ((c) == 0x5c)
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#define periodchar(c) ((c) == PERIOD)
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#define asterchar(c) ((c) == 0x2a)
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#define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \
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|| ((c) >= 0x61 && (c) <= 0x7a))
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#define digitchar(c) ((c) >= 0x30 && (c) <= 0x39)
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#define borderchar(c) (alphachar(c) || digitchar(c))
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#define middlechar(c) (borderchar(c) || hyphenchar(c))
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#define domainchar(c) ((c) > 0x20 && (c) < 0x7f)
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int
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res_hnok(dn)
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const char *dn;
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{
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int ppch = '\0', pch = PERIOD, ch = *dn++;
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while (ch != '\0') {
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int nch = *dn++;
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if (periodchar(ch)) {
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NULL;
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} else if (periodchar(pch)) {
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if (!borderchar(ch))
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return (0);
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} else if (periodchar(nch) || nch == '\0') {
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if (!borderchar(ch))
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return (0);
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} else {
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if (!middlechar(ch))
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return (0);
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}
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ppch = pch, pch = ch, ch = nch;
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}
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return (1);
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}
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/*
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* hostname-like (A, MX, WKS) owners can have "*" as their first label
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* but must otherwise be as a host name.
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*/
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int
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res_ownok(dn)
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const char *dn;
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{
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if (asterchar(dn[0])) {
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if (periodchar(dn[1]))
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return (res_hnok(dn+2));
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if (dn[1] == '\0')
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return (1);
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}
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return (res_hnok(dn));
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}
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/*
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* SOA RNAMEs and RP RNAMEs can have any printable character in their first
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* label, but the rest of the name has to look like a host name.
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*/
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int
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res_mailok(dn)
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const char *dn;
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{
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int ch, escaped = 0;
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/* "." is a valid missing representation */
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if (*dn == '\0')
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return(1);
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/* otherwise <label>.<hostname> */
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while ((ch = *dn++) != '\0') {
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if (!domainchar(ch))
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return (0);
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if (!escaped && periodchar(ch))
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break;
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if (escaped)
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escaped = 0;
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else if (bslashchar(ch))
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escaped = 1;
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}
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if (periodchar(ch))
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return (res_hnok(dn));
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return(0);
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}
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/*
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* This function is quite liberal, since RFC 1034's character sets are only
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* recommendations.
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*/
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int
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res_dnok(dn)
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const char *dn;
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{
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int ch;
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while ((ch = *dn++) != '\0')
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if (!domainchar(ch))
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return (0);
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return (1);
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}
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/*
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* Routines to insert/extract short/long's.
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*/
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u_int16_t
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_getshort(msgp)
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register const u_char *msgp;
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{
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register u_int16_t u;
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GETSHORT(u, msgp);
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return (u);
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}
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u_int32_t
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_getlong(msgp)
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register const u_char *msgp;
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{
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register u_int32_t u;
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GETLONG(u, msgp);
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return (u);
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}
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void
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#if defined(__STDC__) || defined(__cplusplus)
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__putshort(register u_int16_t s, register u_char *msgp) /* must match proto */
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#else
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__putshort(s, msgp)
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register u_int16_t s;
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register u_char *msgp;
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#endif
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{
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PUTSHORT(s, msgp);
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}
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void
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__putlong(l, msgp)
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register u_int32_t l;
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register u_char *msgp;
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{
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PUTLONG(l, msgp);
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}
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/* ++ From BIND 8.1.1. ++ */
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/*
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* Copyright (c) 1996 by Internet Software Consortium.
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
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*
|
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* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
|
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* 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
|
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* SOFTWARE.
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*/
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/*"Id: ns_name.c,v 1.1 1997/12/13 02:41:13 vixie Exp vixie"*/
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/*#include "port_before.h"*/
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/*#include <sys/types.h>*/
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/*#include <netinet/in.h>*/
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/*#include <arpa/nameser.h>*/
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/*#include <errno.h>*/
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/*#include <resolv.h>*/
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/*#include <string.h>*/
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/*#include "port_after.h"*/
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#define NS_CMPRSFLGS 0xc0 /* Flag bits indicating name compression. */
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#define NS_MAXCDNAME 255 /* maximum compressed domain name */
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/* Data. */
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static char digits[] = "0123456789";
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/* Forward. */
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static int special(int);
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static int printable(int);
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static int dn_find(const u_char *, const u_char *,
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const u_char * const *,
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const u_char * const *);
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/* Public. */
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/*
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* ns_name_ntop(src, dst, dstsiz)
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* Convert an encoded domain name to printable ascii as per RFC1035.
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* return:
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* Number of bytes written to buffer, or -1 (with errno set)
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* notes:
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* The root is returned as "."
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* All other domains are returned in non absolute form
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*/
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static int
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ns_name_ntop(src, dst, dstsiz)
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const u_char *src;
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char *dst;
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size_t dstsiz;
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{
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const u_char *cp;
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char *dn, *eom;
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u_char c;
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u_int n;
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cp = src;
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dn = dst;
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eom = dst + dstsiz;
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while ((n = *cp++) != 0) {
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if ((n & NS_CMPRSFLGS) != 0) {
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/* Some kind of compression pointer. */
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errno = EMSGSIZE;
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return (-1);
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}
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if (dn != dst) {
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if (dn >= eom) {
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errno = EMSGSIZE;
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return (-1);
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}
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*dn++ = '.';
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}
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if (dn + n >= eom) {
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errno = EMSGSIZE;
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return (-1);
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}
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for ((void)NULL; n > 0; n--) {
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c = *cp++;
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if (special(c)) {
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if (dn + 1 >= eom) {
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errno = EMSGSIZE;
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return (-1);
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}
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*dn++ = '\\';
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*dn++ = (char)c;
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} else if (!printable(c)) {
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if (dn + 3 >= eom) {
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errno = EMSGSIZE;
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return (-1);
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}
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*dn++ = '\\';
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*dn++ = digits[c / 100];
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*dn++ = digits[(c % 100) / 10];
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*dn++ = digits[c % 10];
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} else {
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if (dn >= eom) {
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errno = EMSGSIZE;
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return (-1);
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}
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*dn++ = (char)c;
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}
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}
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}
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if (dn == dst) {
|
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if (dn >= eom) {
|
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errno = EMSGSIZE;
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return (-1);
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}
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*dn++ = '.';
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}
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if (dn >= eom) {
|
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errno = EMSGSIZE;
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return (-1);
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}
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*dn++ = '\0';
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return (dn - dst);
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}
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|
|
/*
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* ns_name_pton(src, dst, dstsiz)
|
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* Convert a ascii string into an encoded domain name as per RFC1035.
|
|
* return:
|
|
* -1 if it fails
|
|
* 1 if string was fully qualified
|
|
* 0 is string was not fully qualified
|
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* notes:
|
|
* Enforces label and domain length limits.
|
|
*/
|
|
|
|
static int
|
|
ns_name_pton(src, dst, dstsiz)
|
|
const char *src;
|
|
u_char *dst;
|
|
size_t dstsiz;
|
|
{
|
|
u_char *label, *bp, *eom;
|
|
int c, n, escaped;
|
|
char *cp;
|
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|
escaped = 0;
|
|
bp = dst;
|
|
eom = dst + dstsiz;
|
|
label = bp++;
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|
|
|
while ((c = *src++) != 0) {
|
|
if (escaped) {
|
|
if ((cp = strchr(digits, c)) != NULL) {
|
|
n = (cp - digits) * 100;
|
|
if ((c = *src++) == 0 ||
|
|
(cp = strchr(digits, c)) == NULL) {
|
|
errno = EMSGSIZE;
|
|
return (-1);
|
|
}
|
|
n += (cp - digits) * 10;
|
|
if ((c = *src++) == 0 ||
|
|
(cp = strchr(digits, c)) == NULL) {
|
|
errno = EMSGSIZE;
|
|
return (-1);
|
|
}
|
|
n += (cp - digits);
|
|
if (n > 255) {
|
|
errno = EMSGSIZE;
|
|
return (-1);
|
|
}
|
|
c = n;
|
|
}
|
|
escaped = 0;
|
|
} else if (c == '\\') {
|
|
escaped = 1;
|
|
continue;
|
|
} else if (c == '.') {
|
|
c = (bp - label - 1);
|
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if ((c & NS_CMPRSFLGS) != 0) { /* Label too big. */
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|
errno = EMSGSIZE;
|
|
return (-1);
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|
}
|
|
if (label >= eom) {
|
|
errno = EMSGSIZE;
|
|
return (-1);
|
|
}
|
|
*label = c;
|
|
/* Fully qualified ? */
|
|
if (*src == '\0') {
|
|
if (c != 0) {
|
|
if (bp >= eom) {
|
|
errno = EMSGSIZE;
|
|
return (-1);
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|
}
|
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*bp++ = '\0';
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|
}
|
|
if ((bp - dst) > MAXCDNAME) {
|
|
errno = EMSGSIZE;
|
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return (-1);
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|
}
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|
return (1);
|
|
}
|
|
if (c == 0) {
|
|
errno = EMSGSIZE;
|
|
return (-1);
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}
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|
label = bp++;
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|
continue;
|
|
}
|
|
if (bp >= eom) {
|
|
errno = EMSGSIZE;
|
|
return (-1);
|
|
}
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|
*bp++ = (u_char)c;
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|
}
|
|
c = (bp - label - 1);
|
|
if ((c & NS_CMPRSFLGS) != 0) { /* Label too big. */
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|
errno = EMSGSIZE;
|
|
return (-1);
|
|
}
|
|
if (label >= eom) {
|
|
errno = EMSGSIZE;
|
|
return (-1);
|
|
}
|
|
*label = c;
|
|
if (c != 0) {
|
|
if (bp >= eom) {
|
|
errno = EMSGSIZE;
|
|
return (-1);
|
|
}
|
|
*bp++ = 0;
|
|
}
|
|
if ((bp - dst) > MAXCDNAME) { /* src too big */
|
|
errno = EMSGSIZE;
|
|
return (-1);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* ns_name_unpack(msg, eom, src, dst, dstsiz)
|
|
* Unpack a domain name from a message, source may be compressed.
|
|
* return:
|
|
* -1 if it fails, or consumed octets if it succeeds.
|
|
*/
|
|
static int
|
|
ns_name_unpack(msg, eom, src, dst, dstsiz)
|
|
const u_char *msg;
|
|
const u_char *eom;
|
|
const u_char *src;
|
|
u_char *dst;
|
|
size_t dstsiz;
|
|
{
|
|
const u_char *srcp, *dstlim;
|
|
u_char *dstp;
|
|
int n, c, len, checked;
|
|
|
|
len = -1;
|
|
checked = 0;
|
|
dstp = dst;
|
|
srcp = src;
|
|
dstlim = dst + dstsiz;
|
|
if (srcp < msg || srcp >= eom) {
|
|
errno = EMSGSIZE;
|
|
return (-1);
|
|
}
|
|
/* Fetch next label in domain name. */
|
|
while ((n = *srcp++) != 0) {
|
|
/* Check for indirection. */
|
|
switch (n & NS_CMPRSFLGS) {
|
|
case 0:
|
|
/* Limit checks. */
|
|
if (dstp + n + 1 >= dstlim || srcp + n >= eom) {
|
|
errno = EMSGSIZE;
|
|
return (-1);
|
|
}
|
|
checked += n + 1;
|
|
*dstp++ = n;
|
|
memcpy(dstp, srcp, n);
|
|
dstp += n;
|
|
srcp += n;
|
|
break;
|
|
|
|
case NS_CMPRSFLGS:
|
|
if (srcp >= eom) {
|
|
errno = EMSGSIZE;
|
|
return (-1);
|
|
}
|
|
if (len < 0)
|
|
len = srcp - src + 1;
|
|
srcp = msg + (((n & 0x3f) << 8) | (*srcp & 0xff));
|
|
if (srcp < msg || srcp >= eom) { /* Out of range. */
|
|
errno = EMSGSIZE;
|
|
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 >= eom - msg) {
|
|
errno = EMSGSIZE;
|
|
return (-1);
|
|
}
|
|
break;
|
|
|
|
default:
|
|
errno = EMSGSIZE;
|
|
return (-1); /* flag error */
|
|
}
|
|
}
|
|
*dstp = '\0';
|
|
if (len < 0)
|
|
len = srcp - src;
|
|
return (len);
|
|
}
|
|
|
|
/*
|
|
* ns_name_pack(src, dst, dstsiz, dnptrs, lastdnptr)
|
|
* Pack domain name 'domain' into 'comp_dn'.
|
|
* return:
|
|
* Size of the compressed name, or -1.
|
|
* notes:
|
|
* 'dnptrs' is an array of pointers to previous compressed names.
|
|
* dnptrs[0] is a pointer to the beginning of the message. The array
|
|
* ends with NULL.
|
|
* 'lastdnptr' is a pointer to the end of the array pointed to
|
|
* by 'dnptrs'.
|
|
* Side effects:
|
|
* The list of pointers in dnptrs is updated 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.
|
|
*/
|
|
static int
|
|
ns_name_pack(src, dst, dstsiz, dnptrs, lastdnptr)
|
|
const u_char *src;
|
|
u_char *dst;
|
|
int dstsiz;
|
|
const u_char **dnptrs;
|
|
const u_char **lastdnptr;
|
|
{
|
|
u_char *dstp;
|
|
const u_char **cpp, **lpp, *eob, *msg;
|
|
const u_char *srcp;
|
|
int n, l;
|
|
|
|
srcp = src;
|
|
dstp = dst;
|
|
eob = dstp + dstsiz;
|
|
lpp = cpp = NULL;
|
|
if (dnptrs != NULL) {
|
|
if ((msg = *dnptrs++) != NULL) {
|
|
for (cpp = dnptrs; *cpp != NULL; cpp++)
|
|
(void)NULL;
|
|
lpp = cpp; /* end of list to search */
|
|
}
|
|
} else
|
|
msg = NULL;
|
|
|
|
/* make sure the domain we are about to add is legal */
|
|
l = 0;
|
|
do {
|
|
n = *srcp;
|
|
if ((n & NS_CMPRSFLGS) != 0) {
|
|
errno = EMSGSIZE;
|
|
return (-1);
|
|
}
|
|
l += n + 1;
|
|
if (l > MAXCDNAME) {
|
|
errno = EMSGSIZE;
|
|
return (-1);
|
|
}
|
|
srcp += n + 1;
|
|
} while (n != 0);
|
|
|
|
srcp = src;
|
|
do {
|
|
/* Look to see if we can use pointers. */
|
|
n = *srcp;
|
|
if (n != 0 && msg != NULL) {
|
|
l = dn_find(srcp, msg, (const u_char * const *)dnptrs,
|
|
(const u_char * const *)lpp);
|
|
if (l >= 0) {
|
|
if (dstp + 1 >= eob) {
|
|
errno = EMSGSIZE;
|
|
return (-1);
|
|
}
|
|
*dstp++ = (l >> 8) | NS_CMPRSFLGS;
|
|
*dstp++ = l % 256;
|
|
return (dstp - dst);
|
|
}
|
|
/* Not found, save it. */
|
|
if (lastdnptr != NULL && cpp < lastdnptr - 1 &&
|
|
(dstp - msg) < 0x4000) {
|
|
*cpp++ = dstp;
|
|
*cpp = NULL;
|
|
}
|
|
}
|
|
/* copy label to buffer */
|
|
if (n & NS_CMPRSFLGS) { /* Should not happen. */
|
|
errno = EMSGSIZE;
|
|
return (-1);
|
|
}
|
|
if (dstp + 1 + n >= eob) {
|
|
errno = EMSGSIZE;
|
|
return (-1);
|
|
}
|
|
memcpy(dstp, srcp, n + 1);
|
|
srcp += n + 1;
|
|
dstp += n + 1;
|
|
} while (n != 0);
|
|
|
|
if (dstp > eob) {
|
|
if (msg != NULL)
|
|
*lpp = NULL;
|
|
errno = EMSGSIZE;
|
|
return (-1);
|
|
}
|
|
return (dstp - dst);
|
|
}
|
|
|
|
/*
|
|
* ns_name_uncompress(msg, eom, src, dst, dstsiz)
|
|
* Expand compressed domain name to presentation format.
|
|
* return:
|
|
* Number of bytes read out of `src', or -1 (with errno set).
|
|
* note:
|
|
* Root domain returns as "." not "".
|
|
*/
|
|
static int
|
|
ns_name_uncompress(msg, eom, src, dst, dstsiz)
|
|
const u_char *msg;
|
|
const u_char *eom;
|
|
const u_char *src;
|
|
char *dst;
|
|
size_t dstsiz;
|
|
{
|
|
u_char tmp[NS_MAXCDNAME];
|
|
int n;
|
|
|
|
if ((n = ns_name_unpack(msg, eom, src, tmp, sizeof tmp)) == -1)
|
|
return (-1);
|
|
if (ns_name_ntop(tmp, dst, dstsiz) == -1)
|
|
return (-1);
|
|
return (n);
|
|
}
|
|
|
|
/*
|
|
* ns_name_compress(src, dst, dstsiz, dnptrs, lastdnptr)
|
|
* Compress a domain name into wire format, using compression pointers.
|
|
* return:
|
|
* Number of bytes consumed in `dst' or -1 (with errno set).
|
|
* notes:
|
|
* 'dnptrs' is an array 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
|
|
* array 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.
|
|
*/
|
|
static int
|
|
ns_name_compress(src, dst, dstsiz, dnptrs, lastdnptr)
|
|
const char *src;
|
|
u_char *dst;
|
|
size_t dstsiz;
|
|
const u_char **dnptrs;
|
|
const u_char **lastdnptr;
|
|
{
|
|
u_char tmp[NS_MAXCDNAME];
|
|
|
|
if (ns_name_pton(src, tmp, sizeof tmp) == -1)
|
|
return (-1);
|
|
return (ns_name_pack(tmp, dst, dstsiz, dnptrs, lastdnptr));
|
|
}
|
|
|
|
/*
|
|
* ns_name_skip(ptrptr, eom)
|
|
* Advance *ptrptr to skip over the compressed name it points at.
|
|
* return:
|
|
* 0 on success, -1 (with errno set) on failure.
|
|
*/
|
|
static int
|
|
ns_name_skip(ptrptr, eom)
|
|
const u_char **ptrptr;
|
|
const u_char *eom;
|
|
{
|
|
const u_char *cp;
|
|
u_int n;
|
|
|
|
cp = *ptrptr;
|
|
while (cp < eom && (n = *cp++) != 0) {
|
|
/* Check for indirection. */
|
|
switch (n & NS_CMPRSFLGS) {
|
|
case 0: /* normal case, n == len */
|
|
cp += n;
|
|
continue;
|
|
case NS_CMPRSFLGS: /* indirection */
|
|
cp++;
|
|
break;
|
|
default: /* illegal type */
|
|
errno = EMSGSIZE;
|
|
return (-1);
|
|
}
|
|
break;
|
|
}
|
|
if (cp > eom) {
|
|
errno = EMSGSIZE;
|
|
return (-1);
|
|
}
|
|
*ptrptr = cp;
|
|
return (0);
|
|
}
|
|
|
|
/* Private. */
|
|
|
|
/*
|
|
* special(ch)
|
|
* Thinking in noninternationalized USASCII (per the DNS spec),
|
|
* is this characted special ("in need of quoting") ?
|
|
* return:
|
|
* boolean.
|
|
*/
|
|
static int
|
|
special(ch)
|
|
int ch;
|
|
{
|
|
switch (ch) {
|
|
case 0x22: /* '"' */
|
|
case 0x2E: /* '.' */
|
|
case 0x3B: /* ';' */
|
|
case 0x5C: /* '\\' */
|
|
/* Special modifiers in zone files. */
|
|
case 0x40: /* '@' */
|
|
case 0x24: /* '$' */
|
|
return (1);
|
|
default:
|
|
return (0);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* printable(ch)
|
|
* Thinking in noninternationalized USASCII (per the DNS spec),
|
|
* is this character visible and not a space when printed ?
|
|
* return:
|
|
* boolean.
|
|
*/
|
|
static int
|
|
printable(ch)
|
|
int ch;
|
|
{
|
|
return (ch > 0x20 && ch < 0x7f);
|
|
}
|
|
|
|
/*
|
|
* Thinking in noninternationalized USASCII (per the DNS spec),
|
|
* convert this character to lower case if it's upper case.
|
|
*/
|
|
static int
|
|
mklower(ch)
|
|
int ch;
|
|
{
|
|
if (ch >= 0x41 && ch <= 0x5A)
|
|
return (ch + 0x20);
|
|
return (ch);
|
|
}
|
|
|
|
/*
|
|
* dn_find(domain, msg, dnptrs, lastdnptr)
|
|
* Search for the counted-label name in an array of compressed names.
|
|
* return:
|
|
* offset from msg if found, or -1.
|
|
* notes:
|
|
* dnptrs is the pointer to the first name on the list,
|
|
* not the pointer to the start of the message.
|
|
*/
|
|
static int
|
|
dn_find(domain, msg, dnptrs, lastdnptr)
|
|
const u_char *domain;
|
|
const u_char *msg;
|
|
const u_char * const *dnptrs;
|
|
const u_char * const *lastdnptr;
|
|
{
|
|
const u_char *dn, *cp, *sp;
|
|
const u_char * const *cpp;
|
|
u_int n;
|
|
|
|
for (cpp = dnptrs; cpp < lastdnptr; cpp++) {
|
|
dn = domain;
|
|
sp = cp = *cpp;
|
|
while ((n = *cp++) != 0) {
|
|
/*
|
|
* check for indirection
|
|
*/
|
|
switch (n & NS_CMPRSFLGS) {
|
|
case 0: /* normal case, n == len */
|
|
if (n != *dn++)
|
|
goto next;
|
|
for ((void)NULL; n > 0; n--)
|
|
if (mklower(*dn++) != mklower(*cp++))
|
|
goto next;
|
|
/* Is next root for both ? */
|
|
if (*dn == '\0' && *cp == '\0')
|
|
return (sp - msg);
|
|
if (*dn)
|
|
continue;
|
|
goto next;
|
|
|
|
case NS_CMPRSFLGS: /* indirection */
|
|
cp = msg + (((n & 0x3f) << 8) | *cp);
|
|
break;
|
|
|
|
default: /* illegal type */
|
|
errno = EMSGSIZE;
|
|
return (-1);
|
|
}
|
|
}
|
|
next: ;
|
|
}
|
|
errno = ENOENT;
|
|
return (-1);
|
|
}
|
|
|
|
/* -- From BIND 8.1.1. -- */
|