1/* Copyright (C) 1998-2022 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. */
31static 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
50static 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. */
71const 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
80attribute_hidden
81struct __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. */
150void
151__wcsmbs_load_conv (struct __locale_data *new_category)
152{
153 /* Acquire the lock. */
154 __libc_rwlock_wrlock (__libc_setlocale_lock);
155
156 /* We should repeat the test since while we waited some other thread
157 might have run this function. */
158 if (__glibc_likely (new_category->private.ctype == NULL))
159 {
160 /* We must find the real functions. */
161 const char *charset_name;
162 const char *complete_name;
163 struct gconv_fcts *new_fcts;
164 int use_translit;
165
166 /* Allocate the gconv_fcts structure. */
167 new_fcts = calloc (1, sizeof *new_fcts);
168 if (new_fcts == NULL)
169 goto failed;
170
171 /* Get name of charset of the locale. */
172 charset_name = new_category->values[_NL_ITEM_INDEX(CODESET)].string;
173
174 /* Does the user want transliteration? */
175 use_translit = new_category->use_translit;
176
177 /* Normalize the name and add the slashes necessary for a
178 complete lookup. */
179 complete_name = norm_add_slashes (charset_name,
180 use_translit ? "TRANSLIT" : "");
181
182 /* It is not necessary to use transliteration in this direction
183 since the internal character set is supposed to be able to
184 represent all others. */
185 new_fcts->towc = __wcsmbs_getfct ("INTERNAL", complete_name,
186 &new_fcts->towc_nsteps);
187 if (new_fcts->towc != NULL)
188 new_fcts->tomb = __wcsmbs_getfct (complete_name, "INTERNAL",
189 &new_fcts->tomb_nsteps);
190
191 /* If any of the conversion functions is not available we don't
192 use any since this would mean we cannot convert back and
193 forth. NB: NEW_FCTS was allocated with calloc. */
194 if (new_fcts->tomb == NULL)
195 {
196 if (new_fcts->towc != NULL)
197 __gconv_close_transform (new_fcts->towc, new_fcts->towc_nsteps);
198
199 free (new_fcts);
200
201 failed:
202 new_category->private.ctype = &__wcsmbs_gconv_fcts_c;
203 }
204 else
205 {
206 new_category->private.ctype = new_fcts;
207 new_category->private.cleanup = &_nl_cleanup_ctype;
208 }
209 }
210
211 __libc_rwlock_unlock (__libc_setlocale_lock);
212}
213
214
215/* Clone the current conversion function set. */
216void
217__wcsmbs_clone_conv (struct gconv_fcts *copy)
218{
219 const struct gconv_fcts *orig;
220
221 orig = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
222
223 /* Copy the data. */
224 *copy = *orig;
225
226 /* Now increment the usage counters. Note: This assumes
227 copy->*_nsteps == 1. The current locale holds a reference, so it
228 is still there after acquiring the lock. */
229
230 __libc_lock_lock (__gconv_lock);
231
232 bool overflow = false;
233 if (copy->towc->__shlib_handle != NULL)
234 overflow |= __builtin_add_overflow (copy->towc->__counter, 1,
235 &copy->towc->__counter);
236 if (copy->tomb->__shlib_handle != NULL)
237 overflow |= __builtin_add_overflow (copy->tomb->__counter, 1,
238 &copy->tomb->__counter);
239
240 __libc_lock_unlock (__gconv_lock);
241
242 if (overflow)
243 __libc_fatal ("\
244Fatal glibc error: gconv module reference counter overflow\n");
245}
246
247
248/* Get converters for named charset. */
249int
250__wcsmbs_named_conv (struct gconv_fcts *copy, const char *name)
251{
252 copy->towc = __wcsmbs_getfct ("INTERNAL", name, &copy->towc_nsteps);
253 if (copy->towc == NULL)
254 return 1;
255
256 copy->tomb = __wcsmbs_getfct (name, "INTERNAL", &copy->tomb_nsteps);
257 if (copy->tomb == NULL)
258 {
259 __gconv_close_transform (copy->towc, copy->towc_nsteps);
260 return 1;
261 }
262
263 return 0;
264}
265
266void
267_nl_cleanup_ctype (struct __locale_data *locale)
268{
269 const struct gconv_fcts *const data = locale->private.ctype;
270 if (data != NULL)
271 {
272 locale->private.ctype = NULL;
273 locale->private.cleanup = NULL;
274
275 /* Free the old conversions. */
276 __gconv_close_transform (data->tomb, data->tomb_nsteps);
277 __gconv_close_transform (data->towc, data->towc_nsteps);
278 free ((char *) data);
279 }
280}
281