freebsd-skq/lib/libc/net/nss_compat.c
nectar 7ec3e33301 When a dynamic NSS module is built and linked against a thread
library, it may pull in that thread library at run time.  If the
process started out single-threaded, this could cause attempts to
release locks that do not exist.  Guard against this possibility by
checking __isthreaded before invoking thread primitives.

A similar problem remains if the process is linked against one thread
library, but the NSS module is linked against another.  This can only
be avoided by careful design of the NSS module.

Submitted by:	Sean McNeil <sean@mcneil.com> (mostly; bugs are mine)
2004-03-30 15:56:15 +00:00

279 lines
7.0 KiB
C

/*-
* Copyright (c) 2003 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed for the FreeBSD Project by
* Jacques A. Vidrine, Safeport Network Services, and Network
* Associates Laboratories, the Security Research Division of Network
* Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
* ("CBOSS"), as part of the DARPA CHATS research program.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* Compatibility shims for the GNU C Library-style nsswitch interface.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "namespace.h"
#include <sys/param.h>
#include <errno.h>
#include <nss.h>
#include <pthread.h>
#include <pthread_np.h>
#include "un-namespace.h"
#include "libc_private.h"
struct group;
struct passwd;
static int terminator;
#define DECLARE_TERMINATOR(x) \
static pthread_key_t _term_key_##x; \
static void \
_term_create_##x(void) \
{ \
(void)_pthread_key_create(&_term_key_##x, NULL); \
} \
static void *_term_main_##x; \
static pthread_once_t _term_once_##x = PTHREAD_ONCE_INIT
#define SET_TERMINATOR(x, y) \
do { \
if (!__isthreaded || _pthread_main_np()) \
_term_main_##x = (y); \
else { \
(void)_pthread_once(&_term_once_##x, _term_create_##x); \
(void)_pthread_setspecific(_term_key_##x, y); \
} \
} while (0)
#define CHECK_TERMINATOR(x) \
(!__isthreaded || _pthread_main_np() ? \
(_term_main_##x) : \
((void)_pthread_once(&_term_once_##x, _term_create_##x), \
_pthread_getspecific(_term_key_##x)))
DECLARE_TERMINATOR(group);
int
__nss_compat_getgrnam_r(void *retval, void *mdata, va_list ap)
{
int (*fn)(const char *, struct group *, char *, size_t, int *);
const char *name;
struct group *grp;
char *buffer;
int *errnop;
size_t bufsize;
enum nss_status status;
fn = mdata;
name = va_arg(ap, const char *);
grp = va_arg(ap, struct group *);
buffer = va_arg(ap, char *);
bufsize = va_arg(ap, size_t);
errnop = va_arg(ap, int *);
status = fn(name, grp, buffer, bufsize, errnop);
status = __nss_compat_result(status, *errnop);
if (status == NS_SUCCESS)
*(struct group **)retval = grp;
return (status);
}
int
__nss_compat_getgrgid_r(void *retval, void *mdata, va_list ap)
{
int (*fn)(gid_t, struct group *, char *, size_t, int *);
gid_t gid;
struct group *grp;
char *buffer;
int *errnop;
size_t bufsize;
enum nss_status status;
fn = mdata;
gid = va_arg(ap, gid_t);
grp = va_arg(ap, struct group *);
buffer = va_arg(ap, char *);
bufsize = va_arg(ap, size_t);
errnop = va_arg(ap, int *);
status = fn(gid, grp, buffer, bufsize, errnop);
status = __nss_compat_result(status, *errnop);
if (status == NS_SUCCESS)
*(struct group **)retval = grp;
return (status);
}
int
__nss_compat_getgrent_r(void *retval, void *mdata, va_list ap)
{
int (*fn)(struct group *, char *, size_t, int *);
struct group *grp;
char *buffer;
int *errnop;
size_t bufsize;
enum nss_status status;
if (CHECK_TERMINATOR(group))
return (NS_NOTFOUND);
fn = mdata;
grp = va_arg(ap, struct group *);
buffer = va_arg(ap, char *);
bufsize = va_arg(ap, size_t);
errnop = va_arg(ap, int *);
status = fn(grp, buffer, bufsize, errnop);
status = __nss_compat_result(status, *errnop);
if (status == NS_SUCCESS)
*(struct group **)retval = grp;
else if (status != NS_RETURN)
SET_TERMINATOR(group, &terminator);
return (status);
}
int
__nss_compat_setgrent(void *retval, void *mdata, va_list ap)
{
SET_TERMINATOR(group, NULL);
((int (*)(void))mdata)();
return (NS_UNAVAIL);
}
int
__nss_compat_endgrent(void *retval, void *mdata, va_list ap)
{
SET_TERMINATOR(group, NULL);
((int (*)(void))mdata)();
return (NS_UNAVAIL);
}
DECLARE_TERMINATOR(passwd);
int
__nss_compat_getpwnam_r(void *retval, void *mdata, va_list ap)
{
int (*fn)(const char *, struct passwd *, char *, size_t, int *);
const char *name;
struct passwd *pwd;
char *buffer;
int *errnop;
size_t bufsize;
enum nss_status status;
fn = mdata;
name = va_arg(ap, const char *);
pwd = va_arg(ap, struct passwd *);
buffer = va_arg(ap, char *);
bufsize = va_arg(ap, size_t);
errnop = va_arg(ap, int *);
status = fn(name, pwd, buffer, bufsize, errnop);
status = __nss_compat_result(status, *errnop);
if (status == NS_SUCCESS)
*(struct passwd **)retval = pwd;
return (status);
}
int
__nss_compat_getpwuid_r(void *retval, void *mdata, va_list ap)
{
int (*fn)(uid_t, struct passwd *, char *, size_t, int *);
uid_t uid;
struct passwd *pwd;
char *buffer;
int *errnop;
size_t bufsize;
enum nss_status status;
fn = mdata;
uid = va_arg(ap, uid_t);
pwd = va_arg(ap, struct passwd *);
buffer = va_arg(ap, char *);
bufsize = va_arg(ap, size_t);
errnop = va_arg(ap, int *);
status = fn(uid, pwd, buffer, bufsize, errnop);
status = __nss_compat_result(status, *errnop);
if (status == NS_SUCCESS)
*(struct passwd **)retval = pwd;
return (status);
}
int
__nss_compat_getpwent_r(void *retval, void *mdata, va_list ap)
{
int (*fn)(struct passwd *, char *, size_t, int *);
struct passwd *pwd;
char *buffer;
int *errnop;
size_t bufsize;
enum nss_status status;
if (CHECK_TERMINATOR(passwd))
return (NS_NOTFOUND);
fn = mdata;
pwd = va_arg(ap, struct passwd *);
buffer = va_arg(ap, char *);
bufsize = va_arg(ap, size_t);
errnop = va_arg(ap, int *);
status = fn(pwd, buffer, bufsize, errnop);
status = __nss_compat_result(status, *errnop);
if (status == NS_SUCCESS)
*(struct passwd **)retval = pwd;
else if (status != NS_RETURN)
SET_TERMINATOR(passwd, &terminator);
return (status);
}
int
__nss_compat_setpwent(void *retval, void *mdata, va_list ap)
{
SET_TERMINATOR(passwd, NULL);
((int (*)(void))mdata)();
return (NS_UNAVAIL);
}
int
__nss_compat_endpwent(void *retval, void *mdata, va_list ap)
{
SET_TERMINATOR(passwd, NULL);
((int (*)(void))mdata)();
return (NS_UNAVAIL);
}