71 lines
2.3 KiB
C
71 lines
2.3 KiB
C
/* Skip over a (potentially compressed) domain name in wire format.
|
|
* 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 <arpa/nameser.h>
|
|
#include <errno.h>
|
|
#include <shlib-compat.h>
|
|
|
|
/* Advances *PTRPTR to skip over the compressed name it points at.
|
|
Returns 0 on success, -1 (with errno set) on failure. */
|
|
int
|
|
___ns_name_skip (const unsigned char **ptrptr, const unsigned char *eom)
|
|
{
|
|
const unsigned char *cp;
|
|
unsigned int n;
|
|
|
|
cp = *ptrptr;
|
|
while (cp < eom)
|
|
{
|
|
n = *cp++;
|
|
if (n == 0)
|
|
{
|
|
/* End of domain name without indirection. */
|
|
*ptrptr = cp;
|
|
return 0;
|
|
}
|
|
|
|
/* Check for indirection. */
|
|
switch (n & NS_CMPRSFLGS)
|
|
{
|
|
case 0: /* Normal case, n == len. */
|
|
if (eom - cp < n)
|
|
goto malformed;
|
|
cp += n;
|
|
break;
|
|
case NS_CMPRSFLGS: /* Indirection. */
|
|
if (cp == eom)
|
|
/* No room for second indirection byte. */
|
|
goto malformed;
|
|
*ptrptr = cp + 1;
|
|
return 0;
|
|
default: /* Illegal type. */
|
|
goto malformed;
|
|
}
|
|
}
|
|
|
|
malformed:
|
|
__set_errno (EMSGSIZE);
|
|
return -1;
|
|
}
|
|
versioned_symbol (libc, ___ns_name_skip, ns_name_skip, GLIBC_2_34);
|
|
versioned_symbol (libc, ___ns_name_skip, __ns_name_skip, GLIBC_PRIVATE);
|
|
libc_hidden_ver (___ns_name_skip, __ns_name_skip)
|
|
|
|
#if OTHER_SHLIB_COMPAT (libresolv, GLIBC_2_9, GLIBC_2_34)
|
|
compat_symbol (libresolv, ___ns_name_skip, ns_name_skip, GLIBC_2_9);
|
|
#endif
|