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/*
* Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
* 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 ISC DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC 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.
*/
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <errno.h>
#include <resolv.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include <limits.h>
# define SPRINTF(x) ((size_t)sprintf x)
/* Forward. */
static int labellen(const u_char *);
/* Public. */
/*%
* Convert a network strings labels into all lowercase.
*
* return:
*\li Number of bytes written to buffer, or -1 (with errno set)
*
* notes:
*\li Enforces label and domain length limits.
*/
int
ns_name_ntol(const u_char *src, u_char *dst, size_t dstsiz)
{
const u_char *cp;
u_char *dn, *eom;
u_char c;
u_int n;
int l;
cp = src;
dn = dst;
eom = dst + dstsiz;
if (dn >= eom) {
__set_errno (EMSGSIZE);
return (-1);
}
while ((n = *cp++) != 0) {
if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) {
/* Some kind of compression pointer. */
__set_errno (EMSGSIZE);
return (-1);
}
*dn++ = n;
if ((l = labellen(cp - 1)) < 0) {
__set_errno (EMSGSIZE);
return (-1);
}
if (dn + l >= eom) {
__set_errno (EMSGSIZE);
return (-1);
}
for ((void)NULL; l > 0; l--) {
c = *cp++;
if (isupper(c))
*dn++ = tolower(c);
else
*dn++ = c;
}
}
*dn++ = '\0';
return (dn - dst);
}
/*%
* Compress a domain name into wire format, using compression pointers.
*
* return:
*\li Number of bytes consumed in `dst' or -1 (with errno set).
*
* notes:
*\li 'dnptrs' is an array of pointers to previous compressed names.
*\li dnptrs[0] is a pointer to the beginning of the message.
*\li 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.
*\li If 'dnptr' is NULL, we don't try to compress names. If 'lastdnptr'
* is NULL, we don't update the list.
*/
int
ns_name_compress(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));
}
libresolv_hidden_def (ns_name_compress)
/*%
* Reset dnptrs so that there are no active references to pointers at or
* after src.
*/
void
ns_name_rollback(const u_char *src, const u_char **dnptrs,
const u_char **lastdnptr)
{
while (dnptrs < lastdnptr && *dnptrs != NULL) {
if (*dnptrs >= src) {
*dnptrs = NULL;
break;
}
dnptrs++;
}
}
/* Private. */
/* Return the length of the encoded label starting at LP, or -1 for
compression references and extended label types. */
static int
labellen (const unsigned char *lp)
{
if (*lp <= 63)
return *lp;
return -1;
}
/*! \file */
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