1/* Copyright (C) 1998-2021 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <ctype.h>
20#include <langinfo.h>
21#include <limits.h>
22#include <stdlib.h>
23#include <stdio.h>
24#include <string.h>
25
26#include <locale/localeinfo.h>
27#include <wcsmbsload.h>
28#include <libc-lock.h>
29
30
31/* These are the descriptions for the default conversion functions. */
32static const struct __gconv_step to_wc =
33{
34 .__shlib_handle = NULL,
35 .__modname = NULL,
36 .__counter = INT_MAX,
37 .__from_name = (char *) "ANSI_X3.4-1968//TRANSLIT",
38 .__to_name = (char *) "INTERNAL",
39 .__fct = __gconv_transform_ascii_internal,
40 .__btowc_fct = __gconv_btwoc_ascii,
41 .__init_fct = NULL,
42 .__end_fct = NULL,
43 .__min_needed_from = 1,
44 .__max_needed_from = 1,
45 .__min_needed_to = 4,
46 .__max_needed_to = 4,
47 .__stateful = 0,
48 .__data = NULL
49};
50
51static const struct __gconv_step to_mb =
52{
53 .__shlib_handle = NULL,
54 .__modname = NULL,
55 .__counter = INT_MAX,
56 .__from_name = (char *) "INTERNAL",
57 .__to_name = (char *) "ANSI_X3.4-1968//TRANSLIT",
58 .__fct = __gconv_transform_internal_ascii,
59 .__btowc_fct = NULL,
60 .__init_fct = NULL,
61 .__end_fct = NULL,
62 .__min_needed_from = 4,
63 .__max_needed_from = 4,
64 .__min_needed_to = 1,
65 .__max_needed_to = 1,
66 .__stateful = 0,
67 .__data = NULL
68};
69
70
71/* For the default locale we only have to handle ANSI_X3.4-1968. */
72const struct gconv_fcts __wcsmbs_gconv_fcts_c =
73{
74 .towc = (struct __gconv_step *) &to_wc,
75 .towc_nsteps = 1,
76 .tomb = (struct __gconv_step *) &to_mb,
77 .tomb_nsteps = 1,
78};
79
80
81attribute_hidden
82struct __gconv_step *
83__wcsmbs_getfct (const char *to, const char *from, size_t *nstepsp)
84{
85 size_t nsteps;
86 struct __gconv_step *result;
87#if 0
88 size_t nstateful;
89 size_t cnt;
90#endif
91
92 if (__gconv_find_transform (to, from, &result, &nsteps, 0) != __GCONV_OK)
93 /* Loading the conversion step is not possible. */
94 return NULL;
95
96 /* Maybe it is someday necessary to allow more than one step.
97 Currently this is not the case since the conversions handled here
98 are from and to INTERNAL and there always is a converted for
99 that. It the directly following code is enabled the libio
100 functions will have to allocate appropriate __gconv_step_data
101 elements instead of only one. */
102#if 0
103 /* Count the number of stateful conversions. Since we will only
104 have one 'mbstate_t' object available we can only deal with one
105 stateful conversion. */
106 nstateful = 0;
107 for (cnt = 0; cnt < nsteps; ++cnt)
108 if (result[cnt].__stateful)
109 ++nstateful;
110 if (nstateful > 1)
111#else
112 if (nsteps > 1)
113#endif
114 {
115 /* We cannot handle this case. */
116 __gconv_close_transform (result, nsteps);
117 result = NULL;
118 }
119 else
120 *nstepsp = nsteps;
121
122 return result;
123}
124
125
126/* Extract from the given locale name the character set portion. Since
127 only the XPG form of the name includes this information we don't have
128 to take care for the CEN form. */
129#define extract_charset_name(str) \
130 ({ \
131 const char *cp = str; \
132 char *result = NULL; \
133 \
134 cp += strcspn (cp, "@.+,"); \
135 if (*cp == '.') \
136 { \
137 const char *endp = ++cp; \
138 while (*endp != '\0' && *endp != '@') \
139 ++endp; \
140 if (endp != cp) \
141 result = strndupa (cp, endp - cp); \
142 } \
143 result; \
144 })
145
146
147/* Some of the functions here must not be used while setlocale is called. */
148__libc_rwlock_define (extern, __libc_setlocale_lock attribute_hidden)
149
150/* Load conversion functions for the currently selected locale. */
151void
152__wcsmbs_load_conv (struct __locale_data *new_category)
153{
154 /* Acquire the lock. */
155 __libc_rwlock_wrlock (__libc_setlocale_lock);
156
157 /* We should repeat the test since while we waited some other thread
158 might have run this function. */
159 if (__glibc_likely (new_category->private.ctype == NULL))
160 {
161 /* We must find the real functions. */
162 const char *charset_name;
163 const char *complete_name;
164 struct gconv_fcts *new_fcts;
165 int use_translit;
166
167 /* Allocate the gconv_fcts structure. */
168 new_fcts = calloc (1, sizeof *new_fcts);
169 if (new_fcts == NULL)
170 goto failed;
171
172 /* Get name of charset of the locale. */
173 charset_name = new_category->values[_NL_ITEM_INDEX(CODESET)].string;
174
175 /* Does the user want transliteration? */
176 use_translit = new_category->use_translit;
177
178 /* Normalize the name and add the slashes necessary for a
179 complete lookup. */
180 complete_name = norm_add_slashes (charset_name,
181 use_translit ? "TRANSLIT" : "");
182
183 /* It is not necessary to use transliteration in this direction
184 since the internal character set is supposed to be able to
185 represent all others. */
186 new_fcts->towc = __wcsmbs_getfct ("INTERNAL", complete_name,
187 &new_fcts->towc_nsteps);
188 if (new_fcts->towc != NULL)
189 new_fcts->tomb = __wcsmbs_getfct (complete_name, "INTERNAL",
190 &new_fcts->tomb_nsteps);
191
192 /* If any of the conversion functions is not available we don't
193 use any since this would mean we cannot convert back and
194 forth. NB: NEW_FCTS was allocated with calloc. */
195 if (new_fcts->tomb == NULL)
196 {
197 if (new_fcts->towc != NULL)
198 __gconv_close_transform (new_fcts->towc, new_fcts->towc_nsteps);
199
200 free (new_fcts);
201
202 failed:
203 new_category->private.ctype = &__wcsmbs_gconv_fcts_c;
204 }
205 else
206 {
207 new_category->private.ctype = new_fcts;
208 new_category->private.cleanup = &_nl_cleanup_ctype;
209 }
210 }
211
212 __libc_rwlock_unlock (__libc_setlocale_lock);
213}
214
215
216/* Clone the current conversion function set. */
217void
218__wcsmbs_clone_conv (struct gconv_fcts *copy)
219{
220 const struct gconv_fcts *orig;
221
222 orig = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
223
224 /* Copy the data. */
225 *copy = *orig;
226
227 /* Now increment the usage counters. Note: This assumes
228 copy->*_nsteps == 1. The current locale holds a reference, so it
229 is still there after acquiring the lock. */
230
231 __libc_lock_lock (__gconv_lock);
232
233 bool overflow = false;
234 if (copy->towc->__shlib_handle != NULL)
235 overflow |= __builtin_add_overflow (copy->towc->__counter, 1,
236 &copy->towc->__counter);
237 if (copy->tomb->__shlib_handle != NULL)
238 overflow |= __builtin_add_overflow (copy->tomb->__counter, 1,
239 &copy->tomb->__counter);
240
241 __libc_lock_unlock (__gconv_lock);
242
243 if (overflow)
244 __libc_fatal ("\
245Fatal glibc error: gconv module reference counter overflow\n");
246}
247
248
249/* Get converters for named charset. */
250int
251__wcsmbs_named_conv (struct gconv_fcts *copy, const char *name)
252{
253 copy->towc = __wcsmbs_getfct ("INTERNAL", name, &copy->towc_nsteps);
254 if (copy->towc == NULL)
255 return 1;
256
257 copy->tomb = __wcsmbs_getfct (name, "INTERNAL", &copy->tomb_nsteps);
258 if (copy->tomb == NULL)
259 {
260 __gconv_close_transform (copy->towc, copy->towc_nsteps);
261 return 1;
262 }
263
264 return 0;
265}
266
267void
268_nl_cleanup_ctype (struct __locale_data *locale)
269{
270 const struct gconv_fcts *const data = locale->private.ctype;
271 if (data != NULL)
272 {
273 locale->private.ctype = NULL;
274 locale->private.cleanup = NULL;
275
276 /* Free the old conversions. */
277 __gconv_close_transform (data->tomb, data->tomb_nsteps);
278 __gconv_close_transform (data->towc, data->towc_nsteps);
279 free ((char *) data);
280 }
281}
282