1 /* Conversion module for UTF-32.
2 Copyright (C) 1999-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
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 <byteswap.h>
20 #include <dlfcn.h>
21 #include <gconv.h>
22 #include <stddef.h>
23 #include <stdint.h>
24 #include <stdlib.h>
25 #include <string.h>
26
27 /* This is the Byte Order Mark character (BOM). */
28 #define BOM 0x0000feffu
29 /* And in the other byte order. */
30 #define BOM_OE 0xfffe0000u
31
32
33 /* Definitions used in the body of the `gconv' function. */
34 #define FROM_LOOP from_utf32_loop
35 #define TO_LOOP to_utf32_loop
36 #define DEFINE_INIT 0
37 #define DEFINE_FINI 0
38 #define MIN_NEEDED_FROM 4
39 #define MIN_NEEDED_TO 4
40 #define ONE_DIRECTION 0
41 #define FROM_DIRECTION (dir == from_utf32)
42 #define PREPARE_LOOP \
43 enum direction dir = ((struct utf32_data *) step->__data)->dir; \
44 enum variant var = ((struct utf32_data *) step->__data)->var; \
45 int swap; \
46 if (FROM_DIRECTION && var == UTF_32) \
47 { \
48 if (__glibc_unlikely (data->__invocation_counter == 0)) \
49 { \
50 /* We have to find out which byte order the file is encoded in. */ \
51 if (inptr + 4 > inend) \
52 return (inptr == inend \
53 ? __GCONV_EMPTY_INPUT : __GCONV_INCOMPLETE_INPUT); \
54 \
55 if (get32 (inptr) == BOM) \
56 /* Simply ignore the BOM character. */ \
57 *inptrp = inptr += 4; \
58 else if (get32 (inptr) == BOM_OE) \
59 { \
60 data->__flags |= __GCONV_SWAP; \
61 *inptrp = inptr += 4; \
62 } \
63 } \
64 } \
65 else if (!FROM_DIRECTION && var == UTF_32 && !data->__internal_use \
66 && data->__invocation_counter == 0) \
67 { \
68 /* Emit the Byte Order Mark. */ \
69 if (__glibc_unlikely (outbuf + 4 > outend)) \
70 return __GCONV_FULL_OUTPUT; \
71 \
72 put32 (outbuf, BOM); \
73 outbuf += 4; \
74 } \
75 else if (__builtin_expect (data->__invocation_counter == 0, 0) \
76 && ((var == UTF_32LE && BYTE_ORDER == BIG_ENDIAN) \
77 || (var == UTF_32BE && BYTE_ORDER == LITTLE_ENDIAN))) \
78 data->__flags |= __GCONV_SWAP; \
79 swap = data->__flags & __GCONV_SWAP;
80 #define EXTRA_LOOP_ARGS , var, swap
81
82
83 /* Direction of the transformation. */
84 enum direction
85 {
86 illegal_dir,
87 to_utf32,
88 from_utf32
89 };
90
91 enum variant
92 {
93 illegal_var,
94 UTF_32,
95 UTF_32LE,
96 UTF_32BE
97 };
98
99 struct utf32_data
100 {
101 enum direction dir;
102 enum variant var;
103 };
104
105
106 extern int gconv_init (struct __gconv_step *step);
107 int
108 gconv_init (struct __gconv_step *step)
109 {
110 /* Determine which direction. */
111 struct utf32_data *new_data;
112 enum direction dir = illegal_dir;
113 enum variant var = illegal_var;
114 int result;
115
116 if (__strcasecmp (step->__from_name, "UTF-32//") == 0)
117 {
118 dir = from_utf32;
119 var = UTF_32;
120 }
121 else if (__strcasecmp (step->__to_name, "UTF-32//") == 0)
122 {
123 dir = to_utf32;
124 var = UTF_32;
125 }
126 else if (__strcasecmp (step->__from_name, "UTF-32BE//") == 0)
127 {
128 dir = from_utf32;
129 var = UTF_32BE;
130 }
131 else if (__strcasecmp (step->__to_name, "UTF-32BE//") == 0)
132 {
133 dir = to_utf32;
134 var = UTF_32BE;
135 }
136 else if (__strcasecmp (step->__from_name, "UTF-32LE//") == 0)
137 {
138 dir = from_utf32;
139 var = UTF_32LE;
140 }
141 else if (__strcasecmp (step->__to_name, "UTF-32LE//") == 0)
142 {
143 dir = to_utf32;
144 var = UTF_32LE;
145 }
146
147 result = __GCONV_NOCONV;
148 if (__builtin_expect (dir, to_utf32) != illegal_dir)
149 {
150 new_data = (struct utf32_data *) malloc (sizeof (struct utf32_data));
151
152 result = __GCONV_NOMEM;
153 if (new_data != NULL)
154 {
155 new_data->dir = dir;
156 new_data->var = var;
157 step->__data = new_data;
158
159 if (dir == from_utf32)
160 {
161 step->__min_needed_from = MIN_NEEDED_FROM;
162 step->__max_needed_from = MIN_NEEDED_FROM;
163 step->__min_needed_to = MIN_NEEDED_TO;
164 step->__max_needed_to = MIN_NEEDED_TO;
165 }
166 else
167 {
168 step->__min_needed_from = MIN_NEEDED_TO;
169 step->__max_needed_from = MIN_NEEDED_TO;
170 step->__min_needed_to = MIN_NEEDED_FROM;
171 step->__max_needed_to = MIN_NEEDED_FROM;
172 }
173
174 step->__stateful = 0;
175
176 result = __GCONV_OK;
177 }
178 }
179
180 return result;
181 }
182
183
184 extern void gconv_end (struct __gconv_step *data);
185 void
186 gconv_end (struct __gconv_step *data)
187 {
188 free (data->__data);
189 }
190
191
192 /* Convert from the internal (UCS4-like) format to UTF-32. */
193 #define MIN_NEEDED_INPUT MIN_NEEDED_TO
194 #define MIN_NEEDED_OUTPUT MIN_NEEDED_FROM
195 #define LOOPFCT TO_LOOP
196 #define BODY \
197 { \
198 uint32_t c = get32 (inptr); \
199 \
200 if (__glibc_unlikely (c >= 0x110000)) \
201 { \
202 STANDARD_TO_LOOP_ERR_HANDLER (4); \
203 } \
204 else if (__glibc_unlikely (c >= 0xd800 && c < 0xe000)) \
205 { \
206 /* Surrogate characters in UCS-4 input are not valid. \
207 We must catch this. If we let surrogates pass through, \
208 attackers could make a security hole exploit by \
209 generating "irregular UTF-32" sequences. */ \
210 result = __GCONV_ILLEGAL_INPUT; \
211 if (! ignore_errors_p ()) \
212 break; \
213 inptr += 4; \
214 ++*irreversible; \
215 continue; \
216 } \
217 \
218 if (swap) \
219 c = bswap_32 (c); \
220 put32 (outptr, c); \
221 \
222 outptr += 4; \
223 inptr += 4; \
224 }
225 #define LOOP_NEED_FLAGS
226 #define EXTRA_LOOP_DECLS \
227 , enum variant var, int swap
228 #include <iconv/loop.c>
229
230
231 /* Convert from UTF-32 to the internal (UCS4-like) format. */
232 #define MIN_NEEDED_INPUT MIN_NEEDED_FROM
233 #define MIN_NEEDED_OUTPUT MIN_NEEDED_TO
234 #define LOOPFCT FROM_LOOP
235 #define BODY \
236 { \
237 uint32_t u1 = get32 (inptr); \
238 \
239 if (swap) \
240 u1 = bswap_32 (u1); \
241 \
242 if (__glibc_unlikely (u1 >= 0x110000 || (u1 >= 0xd800 && u1 < 0xe000))) \
243 { \
244 /* This is illegal. */ \
245 STANDARD_FROM_LOOP_ERR_HANDLER (4); \
246 } \
247 \
248 put32 (outptr, u1); \
249 inptr += 4; \
250 outptr += 4; \
251 }
252 #define LOOP_NEED_FLAGS
253 #define EXTRA_LOOP_DECLS \
254 , enum variant var, int swap
255 #include <iconv/loop.c>
256
257
258 /* Now define the toplevel functions. */
259 #include <iconv/skeleton.c>