glibc/nss/getXXent.c

95 lines
2.8 KiB
C

/* Copyright (C) 1996-2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <libc-lock.h>
#include <stdlib.h>
#include "nsswitch.h"
/*******************************************************************\
|* Here we assume several symbols to be defined: *|
|* *|
|* LOOKUP_TYPE - the return type of the function *|
|* *|
|* GETFUNC_NAME - name of the non-reentrant getXXXent function *|
|* *|
|* BUFLEN - size of static buffer *|
|* *|
|* Optionally the following vars can be defined: *|
|* *|
|* NEED_H_ERRNO - an extra parameter will be passed to point to *|
|* the global `h_errno' variable. *|
|* *|
\*******************************************************************/
/* To make the real sources a bit prettier. */
#define REENTRANT_GETNAME APPEND_R (GETFUNC_NAME)
#define APPEND_R(name) APPEND_R1 (name)
#define APPEND_R1(name) name##_r
#define INTERNAL(name) INTERNAL1 (name)
#define INTERNAL1(name) __##name
/* Sometimes we need to store error codes in the `h_errno' variable. */
#ifdef NEED_H_ERRNO
# define H_ERRNO_PARM , int *h_errnop
# define H_ERRNO_VAR &h_errno
#else
# define H_ERRNO_PARM
# define H_ERRNO_VAR NULL
#endif
/* Prototype of the reentrant version. */
extern int INTERNAL (REENTRANT_GETNAME) (LOOKUP_TYPE *resbuf, char *buffer,
size_t buflen, LOOKUP_TYPE **result
H_ERRNO_PARM);
/* We need to protect the dynamic buffer handling. */
__libc_lock_define_initialized (static, lock);
/* This points to the static buffer used. */
libc_freeres_ptr (static char *buffer);
LOOKUP_TYPE *
GETFUNC_NAME (void)
{
static size_t buffer_size;
static union
{
LOOKUP_TYPE l;
void *ptr;
} resbuf;
LOOKUP_TYPE *result;
int save;
/* Get lock. */
__libc_lock_lock (lock);
result = (LOOKUP_TYPE *)
__nss_getent ((getent_r_function) INTERNAL (REENTRANT_GETNAME),
&resbuf.ptr, &buffer, BUFLEN, &buffer_size,
H_ERRNO_VAR);
save = errno;
__libc_lock_unlock (lock);
__set_errno (save);
return result;
}
nss_interface_function (GETFUNC_NAME)