glibc/libidn/idn-stub.c

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/* idn-stub.c --- Stub to dlopen libcidn.so and invoke idna_to_ascii_lz.
* Copyright (C) 2003, 2004 Simon Josefsson
*
* This file is part of GNU Libidn.
*
* GNU Libidn 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.
*
* GNU Libidn 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 GNU Libidn; if not, see <http://www.gnu.org/licenses/>.
*/
#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <dlfcn.h>
#include <gnu/lib-names.h>
#include <bits/libc-lock.h>
/* Get specification for idna_to_ascii_lz. */
#include "idna.h"
/* Handle of the libidn DSO. */
static void *h;
static int (*to_ascii_lz) (const char *input, char **output, int flags);
static int (*to_unicode_lzlz) (const char *input, char **output, int flags);
static void
load_dso (void)
{
/* Lock protecting the DSO loading. */
__libc_lock_define_initialized (static, lock);
__libc_lock_lock (lock);
/* Retest in case some other thread arrived here at the same time. */
if (h == NULL)
{
h = __libc_dlopen (LIBCIDN_SO);
if (h == NULL)
h = (void *) 1l;
else
{
/* Get the function we are interested in. */
to_ascii_lz = __libc_dlsym (h, "idna_to_ascii_lz");
to_unicode_lzlz = __libc_dlsym (h, "idna_to_unicode_lzlz");
if (to_ascii_lz == NULL || to_unicode_lzlz == NULL)
{
__libc_dlclose (h);
h = (void *) 1l;
}
}
}
__libc_lock_unlock (lock);
}
/* Stub to dlopen libcidn.so and invoke the real idna_to_ascii_lz, or
return IDNA_DLOPEN_ERROR on failure. */
int
__idna_to_unicode_lzlz (const char *input, char **output, int flags)
{
/* If the input string contains no "xn--" prefix for a component of
the name we can pass it up right away. */
const char *cp = input;
while (*cp != '\0')
{
if (strncmp (cp, IDNA_ACE_PREFIX, strlen (IDNA_ACE_PREFIX)) == 0)
break;
/* On to the next part of the name. */
cp = __strchrnul (cp, '.');
if (*cp == '.')
++cp;
}
if (*cp == '\0')
{
*output = (char *) input;
return IDNA_SUCCESS;
}
if (h == NULL)
load_dso ();
if (h == (void *) 1l)
return IDNA_DLOPEN_ERROR;
return to_unicode_lzlz (input, output, flags);
}
/* Stub to dlopen libcidn.so and invoke the real idna_to_ascii_lz, or
return IDNA_DLOPEN_ERROR on failure. */
int
__idna_to_ascii_lz (const char *input, char **output, int flags)
{
/* If the input string contains no non-ASCII character the output
string will be the same. No valid locale encoding does not have
this property. */
const char *cp = input;
while (*cp != '\0' && isascii (*cp))
++cp;
if (*cp == '\0')
{
*output = (char *) input;
return IDNA_SUCCESS;
}
if (h == NULL)
load_dso ();
if (h == (void *) 1l)
return IDNA_DLOPEN_ERROR;
return to_ascii_lz (input, output, flags);
}
#ifndef NOT_IN_libc
libc_freeres_fn (unload_libidn)
{
if (h != NULL && h != (void *) 1l)
{
__libc_dlclose (h);
h = (void *) 1l;
}
}
#endif