lib/glibc
1
0
Fork 0
mirror of https://sourceware.org/git/glibc.git synced 2025-08-08 17:42:12 +03:00
Code Activity

resolv: Move ns_name_unpack to its own file and into libc

Browse Source 
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>
This commit is contained in:
Florian Weimer
2021-07-15 08:28:50 +02:00
parent ee3639e0fe
commit 820bb23ff0
69 changed files with 187 additions and 115 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
resolv/Makefile
View File

@@ -33,6 +33,7 @@ routines := \
inet_ntop \
inet_pton \
ns_name_ntop \
ns_name_unpack \
nsap_addr \
res-close \
res-state \

5
resolv/Versions
View File

@@ -26,6 +26,7 @@ libc {
}
GLIBC_2.9 {
ns_name_ntop;
ns_name_unpack;
}
GLIBC_2.34 {
%if PTHREAD_IN_LIBC
@@ -35,6 +36,7 @@ libc {
getaddrinfo_a;
%endif
ns_name_ntop;
ns_name_unpack;
}
GLIBC_PRIVATE {
%if !PTHREAD_IN_LIBC
@@ -45,6 +47,7 @@ libc {
__inet_pton_length;
__res_iclose;
__ns_name_ntop;
__ns_name_unpack;
__resolv_context_get;
__resolv_context_get_override;
__resolv_context_get_preinit;
@@ -147,7 +150,6 @@ libresolv {
ns_name_rollback;
ns_name_skip;
ns_name_uncompress;
ns_name_unpack;
ns_parse_ttl;
ns_parserr;
ns_put16;
@@ -162,7 +164,6 @@ libresolv {
GLIBC_PRIVATE {
__ns_get16;
__ns_get32;
__ns_name_unpack;
__res_context_hostalias;
__res_context_query;
__res_context_search;

81
resolv/ns_name.c
View File

@@ -217,87 +217,6 @@ ns_name_ntol(const u_char *src, u_char *dst, size_t dstsiz)
return (dn - dst);
}
/*%
* Unpack a domain name from a message, source may be compressed.
*
* return:
*\li -1 if it fails, or consumed octets if it succeeds.
*/
int
ns_name_unpack(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, len, checked, l;
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 ((l = labellen(srcp - 1)) < 0) {
__set_errno (EMSGSIZE);
return(-1);
}
if (dstp + l + 1 >= dstlim || srcp + l >= eom) {
__set_errno (EMSGSIZE);
return (-1);
}
checked += l + 1;
*dstp++ = n;
memcpy(dstp, srcp, l);
dstp += l;
srcp += l;
break;
case NS_CMPRSFLGS:
if (srcp >= eom) {
__set_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. */
__set_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) {
__set_errno (EMSGSIZE);
return (-1);
}
break;
default:
__set_errno (EMSGSIZE);
return (-1); /*%< flag error */
}
}
*dstp = '\0';
if (len < 0)
len = srcp - src;
return (len);
}
libresolv_hidden_def (ns_name_unpack)
strong_alias (ns_name_unpack, __ns_name_unpack)
/*%
* Pack domain name 'domain' into 'comp_dn'.
*

115
resolv/ns_name_unpack.c Normal file
View File

@@ -0,0 +1,115 @@
/* 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