1 /* Copyright (C) 1998-2023 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18 #include <ctype.h>
19 #include <langinfo.h>
20 #include <limits.h>
21 #include <stdlib.h>
22 #include <stdio.h>
23 #include <string.h>
24
25 #include <locale/localeinfo.h>
26 #include <wcsmbsload.h>
27 #include <libc-lock.h>
28
29
30 /* These are the descriptions for the default conversion functions. */
31 static const struct __gconv_step to_wc =
32 {
33 .__shlib_handle = NULL,
34 .__modname = NULL,
35 .__counter = INT_MAX,
36 .__from_name = (char *) "ANSI_X3.4-1968//TRANSLIT",
37 .__to_name = (char *) "INTERNAL",
38 .__fct = __gconv_transform_ascii_internal,
39 .__btowc_fct = __gconv_btwoc_ascii,
40 .__init_fct = NULL,
41 .__end_fct = NULL,
42 .__min_needed_from = 1,
43 .__max_needed_from = 1,
44 .__min_needed_to = 4,
45 .__max_needed_to = 4,
46 .__stateful = 0,
47 .__data = NULL
48 };
49
50 static const struct __gconv_step to_mb =
51 {
52 .__shlib_handle = NULL,
53 .__modname = NULL,
54 .__counter = INT_MAX,
55 .__from_name = (char *) "INTERNAL",
56 .__to_name = (char *) "ANSI_X3.4-1968//TRANSLIT",
57 .__fct = __gconv_transform_internal_ascii,
58 .__btowc_fct = NULL,
59 .__init_fct = NULL,
60 .__end_fct = NULL,
61 .__min_needed_from = 4,
62 .__max_needed_from = 4,
63 .__min_needed_to = 1,
64 .__max_needed_to = 1,
65 .__stateful = 0,
66 .__data = NULL
67 };
68
69
70 /* For the default locale we only have to handle ANSI_X3.4-1968. */
71 const struct gconv_fcts __wcsmbs_gconv_fcts_c =
72 {
73 .towc = (struct __gconv_step *) &to_wc,
74 .towc_nsteps = 1,
75 .tomb = (struct __gconv_step *) &to_mb,
76 .tomb_nsteps = 1,
77 };
78
79
80 attribute_hidden
81 struct __gconv_step *
82 __wcsmbs_getfct (const char *to, const char *from, size_t *nstepsp)
83 {
84 size_t nsteps;
85 struct __gconv_step *result;
86 #if 0
87 size_t nstateful;
88 size_t cnt;
89 #endif
90
91 if (__gconv_find_transform (to, from, &result, &nsteps, 0) != __GCONV_OK)
92 /* Loading the conversion step is not possible. */
93 return NULL;
94
95 /* Maybe it is someday necessary to allow more than one step.
96 Currently this is not the case since the conversions handled here
97 are from and to INTERNAL and there always is a converted for
98 that. It the directly following code is enabled the libio
99 functions will have to allocate appropriate __gconv_step_data
100 elements instead of only one. */
101 #if 0
102 /* Count the number of stateful conversions. Since we will only
103 have one 'mbstate_t' object available we can only deal with one
104 stateful conversion. */
105 nstateful = 0;
106 for (cnt = 0; cnt < nsteps; ++cnt)
107 if (result[cnt].__stateful)
108 ++nstateful;
109 if (nstateful > 1)
110 #else
111 if (nsteps > 1)
112 #endif
113 {
114 /* We cannot handle this case. */
115 __gconv_close_transform (result, nsteps);
116 result = NULL;
117 }
118 else
119 *nstepsp = nsteps;
120
121 return result;
122 }
123
124
125 /* Extract from the given locale name the character set portion. Since
126 only the XPG form of the name includes this information we don't have
127 to take care for the CEN form. */
128 #define extract_charset_name(str) \
129 ({ \
130 const char *cp = str; \
131 char *result = NULL; \
132 \
133 cp += strcspn (cp, "@.+,"); \
134 if (*cp == '.') \
135 { \
136 const char *endp = ++cp; \
137 while (*endp != '\0' && *endp != '@') \
138 ++endp; \
139 if (endp != cp) \
140 result = strndupa (cp, endp - cp); \
141 } \
142 result; \
143 })
144
145
146 /* Some of the functions here must not be used while setlocale is called. */
147 __libc_rwlock_define (extern, __libc_setlocale_lock attribute_hidden)
148
149 /* Load conversion functions for the currently selected locale. */
150 void
151 __wcsmbs_load_conv (struct __locale_data *new_category)
152 {
153 struct lc_ctype_data *data = new_category->private;
154
155 /* Acquire the lock. */
156 __libc_rwlock_wrlock (__libc_setlocale_lock);
157
158 /* We should repeat the test since while we waited some other thread
159 might have run this function. */
160 if (__glibc_likely (data->fcts == NULL))
161 {
162 /* We must find the real functions. */
163 const char *charset_name;
164 const char *complete_name;
165 struct gconv_fcts *new_fcts;
166 int use_translit;
167
168 /* Allocate the gconv_fcts structure. */
169 new_fcts = calloc (1, sizeof *new_fcts);
170 if (new_fcts == NULL)
171 goto failed;
172
173 /* Get name of charset of the locale. */
174 charset_name = new_category->values[_NL_ITEM_INDEX(CODESET)].string;
175
176 /* Does the user want transliteration? */
177 use_translit = new_category->use_translit;
178
179 /* Normalize the name and add the slashes necessary for a
180 complete lookup. */
181 complete_name = norm_add_slashes (charset_name,
182 use_translit ? "TRANSLIT" : "");
183
184 /* It is not necessary to use transliteration in this direction
185 since the internal character set is supposed to be able to
186 represent all others. */
187 new_fcts->towc = __wcsmbs_getfct ("INTERNAL", complete_name,
188 &new_fcts->towc_nsteps);
189 if (new_fcts->towc != NULL)
190 new_fcts->tomb = __wcsmbs_getfct (complete_name, "INTERNAL",
191 &new_fcts->tomb_nsteps);
192
193 /* If any of the conversion functions is not available we don't
194 use any since this would mean we cannot convert back and
195 forth. NB: NEW_FCTS was allocated with calloc. */
196 if (new_fcts->tomb == NULL)
197 {
198 if (new_fcts->towc != NULL)
199 __gconv_close_transform (new_fcts->towc, new_fcts->towc_nsteps);
200
201 free (new_fcts);
202
203 failed:
204 data->fcts = (void *) &__wcsmbs_gconv_fcts_c;
205 }
206 else
207 data->fcts = new_fcts;
208 }
209
210 __libc_rwlock_unlock (__libc_setlocale_lock);
211 }
212
213
214 /* Clone the current conversion function set. */
215 void
216 __wcsmbs_clone_conv (struct gconv_fcts *copy)
217 {
218 const struct gconv_fcts *orig;
219
220 orig = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
221
222 /* Copy the data. */
223 *copy = *orig;
224
225 /* Now increment the usage counters. Note: This assumes
226 copy->*_nsteps == 1. The current locale holds a reference, so it
227 is still there after acquiring the lock. */
228
229 __libc_lock_lock (__gconv_lock);
230
231 bool overflow = false;
232 if (copy->towc->__shlib_handle != NULL)
233 overflow |= __builtin_add_overflow (copy->towc->__counter, 1,
234 ©->towc->__counter);
235 if (copy->tomb->__shlib_handle != NULL)
236 overflow |= __builtin_add_overflow (copy->tomb->__counter, 1,
237 ©->tomb->__counter);
238
239 __libc_lock_unlock (__gconv_lock);
240
241 if (overflow)
242 __libc_fatal ("\
243 Fatal glibc error: gconv module reference counter overflow\n");
244 }
245
246
247 /* Get converters for named charset. */
248 int
249 __wcsmbs_named_conv (struct gconv_fcts *copy, const char *name)
250 {
251 copy->towc = __wcsmbs_getfct ("INTERNAL", name, ©->towc_nsteps);
252 if (copy->towc == NULL)
253 return 1;
254
255 copy->tomb = __wcsmbs_getfct (name, "INTERNAL", ©->tomb_nsteps);
256 if (copy->tomb == NULL)
257 {
258 __gconv_close_transform (copy->towc, copy->towc_nsteps);
259 return 1;
260 }
261
262 return 0;
263 }
264
265 void
266 _nl_cleanup_ctype (struct __locale_data *locale)
267 {
268 struct lc_ctype_data *data = locale->private;
269 if (data->fcts != NULL && data->fcts != &__wcsmbs_gconv_fcts_c)
270 {
271 /* Free the old conversions. */
272 __gconv_close_transform (data->fcts->tomb, data->fcts->tomb_nsteps);
273 __gconv_close_transform (data->fcts->towc, data->fcts->towc_nsteps);
274
275 free ((void *) data->fcts);
276 data->fcts = NULL;
277 /* data itself is allocated within locale. */
278 }
279 }