mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-22 21:10:07 +00:00
820bb23ff0
Reformat to GNU style. Avoid out-of-bounds buffer arithmetic. Eliminate the labellen function. The symbol was moved using scripts/move-symbol-to-libc.py. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
116 lines
3.5 KiB
C
116 lines
3.5 KiB
C
/* De-compressing DNS domain names into binary-encoded uncompressed name.
|
|
* 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>
|
|
#include <stddef.h>
|
|
#include <string.h>
|
|
|
|
/* Unpack a domain name from a message, source may be compressed.
|
|
Returns -1 if it fails, or consumed octets if it succeeds. */
|
|
int
|
|
___ns_name_unpack (const unsigned char *msg, const unsigned char *eom,
|
|
const unsigned char *src, unsigned char *dst, size_t dstsiz)
|
|
{
|
|
const unsigned char *srcp, *dstlim;
|
|
unsigned char *dstp;
|
|
int n, len, checked;
|
|
|
|
len = -1;
|
|
checked = 0;
|
|
dstp = dst;
|
|
srcp = src;
|
|
dstlim = dst + dstsiz;
|
|
if (srcp < msg || srcp >= eom)
|
|
{
|
|
__set_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 (n >= 64)
|
|
{
|
|
__set_errno (EMSGSIZE);
|
|
return -1;
|
|
}
|
|
/* NB: n + 1 and >= to cover the *dstp = '\0' assignment
|
|
below. */
|
|
if (n + 1 >= dstlim - dstp || n >= eom - srcp)
|
|
{
|
|
__set_errno (EMSGSIZE);
|
|
return -1;
|
|
}
|
|
checked += n + 1;
|
|
*dstp++ = n;
|
|
memcpy (dstp, srcp, n);
|
|
dstp += n;
|
|
srcp += n;
|
|
break;
|
|
|
|
case NS_CMPRSFLGS:
|
|
if (srcp >= eom)
|
|
{
|
|
__set_errno (EMSGSIZE);
|
|
return -1;
|
|
}
|
|
if (len < 0)
|
|
len = srcp - src + 1;
|
|
{
|
|
int target = ((n & 0x3f) << 8) | *srcp;
|
|
if (target >= eom - msg)
|
|
{
|
|
/* Out of range. */
|
|
__set_errno (EMSGSIZE);
|
|
return -1;
|
|
}
|
|
srcp = msg + target;
|
|
}
|
|
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)
|
|
{
|
|
__set_errno (EMSGSIZE);
|
|
return -1;
|
|
}
|
|
break;
|
|
|
|
default:
|
|
__set_errno (EMSGSIZE);
|
|
return -1;
|
|
}
|
|
}
|
|
*dstp = '\0';
|
|
if (len < 0)
|
|
len = srcp - src;
|
|
return len;
|
|
}
|
|
versioned_symbol (libc, ___ns_name_unpack, ns_name_unpack, GLIBC_2_34);
|
|
versioned_symbol (libc, ___ns_name_unpack, __ns_name_unpack, GLIBC_PRIVATE);
|
|
libc_hidden_ver (___ns_name_unpack, __ns_name_unpack)
|
|
|
|
#if OTHER_SHLIB_COMPAT (libresolv, GLIBC_2_9, GLIBC_2_34)
|
|
compat_symbol (libresolv, ___ns_name_unpack, ns_name_unpack, GLIBC_2_9);
|
|
#endif
|