glibc/nss/getXXbyYY.c
Chris Metcalf 017678433c Suppress incorrect link warnings for NSS symbols
When glibc is built with --enable-static-nss, the warning that
using NSS symbols requires the nss shared objects to be present
is no longer true, as those symbols are built into libc.  Suppress
the warning for those symbols by providing a new macro
(nss_interface_function) for the NSS functions that is defined as
static_link_warning in the normal case, and empty for static NSS.
2012-10-30 14:14:33 -04:00

155 lines
4.2 KiB
C

/* Copyright (C) 1996-2001,2003, 2004 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 <assert.h>
#include <errno.h>
#include <bits/libc-lock.h>
#include <stdlib.h>
#include <resolv.h>
#include "nsswitch.h"
/*******************************************************************\
|* Here we assume several symbols to be defined: *|
|* *|
|* LOOKUP_TYPE - the return type of the function *|
|* *|
|* FUNCTION_NAME - name of the non-reentrant function *|
|* *|
|* DATABASE_NAME - name of the database the function accesses *|
|* (e.g., host, services, ...) *|
|* *|
|* ADD_PARAMS - additional parameter, can vary in number *|
|* *|
|* ADD_VARIABLES - names of additional parameter *|
|* *|
|* BUFLEN - length of buffer allocated for the non *|
|* reentrant version *|
|* *|
|* 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_NAME APPEND_R (FUNCTION_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_tmp
# define H_ERRNO_VAR_P &h_errno_tmp
#else
# define H_ERRNO_PARM
# define H_ERRNO_VAR
# define H_ERRNO_VAR_P NULL
#endif
#ifdef HAVE_AF
# define AF_VAL af
#else
# define AF_VAL AF_INET
#endif
/* Prototype for reentrant version we use here. */
extern int INTERNAL (REENTRANT_NAME) (ADD_PARAMS, 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 *
FUNCTION_NAME (ADD_PARAMS)
{
static size_t buffer_size;
static LOOKUP_TYPE resbuf;
LOOKUP_TYPE *result;
#ifdef NEED_H_ERRNO
int h_errno_tmp = 0;
#endif
/* Get lock. */
__libc_lock_lock (lock);
if (buffer == NULL)
{
buffer_size = BUFLEN;
buffer = (char *) malloc (buffer_size);
}
#ifdef HANDLE_DIGITS_DOTS
if (buffer != NULL)
{
if (__nss_hostname_digits_dots (name, &resbuf, &buffer,
&buffer_size, 0, &result, NULL, AF_VAL,
H_ERRNO_VAR_P))
goto done;
}
#endif
while (buffer != NULL
&& (INTERNAL (REENTRANT_NAME) (ADD_VARIABLES, &resbuf, buffer,
buffer_size, &result H_ERRNO_VAR)
== ERANGE)
#ifdef NEED_H_ERRNO
&& h_errno_tmp == NETDB_INTERNAL
#endif
)
{
char *new_buf;
buffer_size *= 2;
new_buf = (char *) realloc (buffer, buffer_size);
if (new_buf == NULL)
{
/* We are out of memory. Free the current buffer so that the
process gets a chance for a normal termination. */
free (buffer);
__set_errno (ENOMEM);
}
buffer = new_buf;
}
if (buffer == NULL)
result = NULL;
#ifdef HANDLE_DIGITS_DOTS
done:
#endif
/* Release lock. */
__libc_lock_unlock (lock);
#ifdef NEED_H_ERRNO
if (h_errno_tmp != 0)
__set_h_errno (h_errno_tmp);
#endif
return result;
}
nss_interface_function (FUNCTION_NAME)