1/* idn-stub.c --- Stub to dlopen libcidn.so and invoke idna_to_ascii_lz.
2 * Copyright (C) 2003, 2004 Simon Josefsson
3 *
4 * This file is part of GNU Libidn.
5 *
6 * GNU Libidn is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * GNU Libidn is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with GNU Libidn; if not, see <http://www.gnu.org/licenses/>.
18 */
19
20#include <ctype.h>
21#include <stdio.h>
22#include <string.h>
23#include <dlfcn.h>
24#include <gnu/lib-names.h>
25#include <libc-lock.h>
26
27/* Get specification for idna_to_ascii_lz. */
28#include "idna.h"
29
30/* Handle of the libidn DSO. */
31static void *h;
32
33
34static int (*to_ascii_lz) (const char *input, char **output, int flags);
35static int (*to_unicode_lzlz) (const char *input, char **output, int flags);
36
37
38static void
39load_dso (void)
40{
41 /* Lock protecting the DSO loading. */
42 __libc_lock_define_initialized (static, lock);
43
44 __libc_lock_lock (lock);
45
46 /* Retest in case some other thread arrived here at the same time. */
47 if (h == NULL)
48 {
49 h = __libc_dlopen (LIBCIDN_SO);
50
51 if (h == NULL)
52 h = (void *) 1l;
53 else
54 {
55 /* Get the function we are interested in. */
56 to_ascii_lz = __libc_dlsym (h, "idna_to_ascii_lz");
57 to_unicode_lzlz = __libc_dlsym (h, "idna_to_unicode_lzlz");
58 if (to_ascii_lz == NULL || to_unicode_lzlz == NULL)
59 {
60 __libc_dlclose (h);
61 h = (void *) 1l;
62 }
63 }
64 }
65
66 __libc_lock_unlock (lock);
67}
68
69
70/* Stub to dlopen libcidn.so and invoke the real idna_to_ascii_lz, or
71 return IDNA_DLOPEN_ERROR on failure. */
72int
73__idna_to_unicode_lzlz (const char *input, char **output, int flags)
74{
75 /* If the input string contains no "xn--" prefix for a component of
76 the name we can pass it up right away. */
77 const char *cp = input;
78 while (*cp != '\0')
79 {
80 if (strncmp (cp, IDNA_ACE_PREFIX, strlen (IDNA_ACE_PREFIX)) == 0)
81 break;
82
83 /* On to the next part of the name. */
84 cp = __strchrnul (cp, '.');
85 if (*cp == '.')
86 ++cp;
87 }
88
89 if (*cp == '\0')
90 {
91 *output = (char *) input;
92 return IDNA_SUCCESS;
93 }
94
95 if (h == NULL)
96 load_dso ();
97
98 if (h == (void *) 1l)
99 return IDNA_DLOPEN_ERROR;
100
101 return to_unicode_lzlz (input, output, flags);
102}
103
104
105/* Stub to dlopen libcidn.so and invoke the real idna_to_ascii_lz, or
106 return IDNA_DLOPEN_ERROR on failure. */
107int
108__idna_to_ascii_lz (const char *input, char **output, int flags)
109{
110 /* If the input string contains no non-ASCII character the output
111 string will be the same. No valid locale encoding does not have
112 this property. */
113 const char *cp = input;
114 while (*cp != '\0' && isascii (*cp))
115 ++cp;
116
117 if (*cp == '\0')
118 {
119 *output = (char *) input;
120 return IDNA_SUCCESS;
121 }
122
123 if (h == NULL)
124 load_dso ();
125
126 if (h == (void *) 1l)
127 return IDNA_DLOPEN_ERROR;
128
129 return to_ascii_lz (input, output, flags);
130}
131
132
133#if IS_IN (libc)
134libc_freeres_fn (unload_libidn)
135{
136 if (h != NULL && h != (void *) 1l)
137 {
138 __libc_dlclose (h);
139 h = (void *) 1l;
140 }
141}
142#endif
143