3 exFAT file system implementation library.
5 Free exFAT implementation.
6 Copyright (C) 2010-2023 Andrew Nayenko
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation, either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License along
19 with this program; if not, write to the Free Software Foundation, Inc.,
20 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
26 static char* wchar_to_utf8(char* output, wchar_t wc, size_t outsize)
32 *output++ = (char) wc;
38 *output++ = 0xc0 | (wc >> 6);
39 *output++ = 0x80 | (wc & 0x3f);
41 else if (wc <= 0xffff)
45 *output++ = 0xe0 | (wc >> 12);
46 *output++ = 0x80 | ((wc >> 6) & 0x3f);
47 *output++ = 0x80 | (wc & 0x3f);
49 else if (wc <= 0x1fffff)
53 *output++ = 0xf0 | (wc >> 18);
54 *output++ = 0x80 | ((wc >> 12) & 0x3f);
55 *output++ = 0x80 | ((wc >> 6) & 0x3f);
56 *output++ = 0x80 | (wc & 0x3f);
58 else if (wc <= 0x3ffffff)
62 *output++ = 0xf8 | (wc >> 24);
63 *output++ = 0x80 | ((wc >> 18) & 0x3f);
64 *output++ = 0x80 | ((wc >> 12) & 0x3f);
65 *output++ = 0x80 | ((wc >> 6) & 0x3f);
66 *output++ = 0x80 | (wc & 0x3f);
68 else if (wc <= 0x7fffffff)
72 *output++ = 0xfc | (wc >> 30);
73 *output++ = 0x80 | ((wc >> 24) & 0x3f);
74 *output++ = 0x80 | ((wc >> 18) & 0x3f);
75 *output++ = 0x80 | ((wc >> 12) & 0x3f);
76 *output++ = 0x80 | ((wc >> 6) & 0x3f);
77 *output++ = 0x80 | (wc & 0x3f);
85 static const le16_t* utf16_to_wchar(const le16_t* input, wchar_t* wc,
88 if ((le16_to_cpu(input[0]) & 0xfc00) == 0xd800)
90 if (insize < 2 || (le16_to_cpu(input[1]) & 0xfc00) != 0xdc00)
92 *wc = ((wchar_t) (le16_to_cpu(input[0]) & 0x3ff) << 10);
93 *wc |= (le16_to_cpu(input[1]) & 0x3ff);
99 *wc = le16_to_cpu(*input);
104 int exfat_utf16_to_utf8(char* output, const le16_t* input, size_t outsize,
107 const le16_t* iptr = input;
108 const le16_t* iend = input + insize;
110 const char* oend = output + outsize;
115 iptr = utf16_to_wchar(iptr, &wc, iend - iptr);
118 exfat_error("illegal UTF-16 sequence");
121 optr = wchar_to_utf8(optr, wc, oend - optr);
124 exfat_error("name is too long");
125 return -ENAMETOOLONG;
132 exfat_error("name is too long");
133 return -ENAMETOOLONG;
139 static const char* utf8_to_wchar(const char* input, wchar_t* wc,
146 exfat_bug("no input for utf8_to_wchar");
148 if ((input[0] & 0x80) == 0)
150 *wc = (wchar_t) input[0];
153 else if ((input[0] & 0xe0) == 0xc0)
155 *wc = ((wchar_t) input[0] & 0x1f) << 6;
158 else if ((input[0] & 0xf0) == 0xe0)
160 *wc = ((wchar_t) input[0] & 0x0f) << 12;
163 else if ((input[0] & 0xf8) == 0xf0)
165 *wc = ((wchar_t) input[0] & 0x07) << 18;
168 else if ((input[0] & 0xfc) == 0xf8)
170 *wc = ((wchar_t) input[0] & 0x03) << 24;
173 else if ((input[0] & 0xfe) == 0xfc)
175 *wc = ((wchar_t) input[0] & 0x01) << 30;
184 /* the first byte is handled above */
185 for (i = 1; i < size; i++)
187 if ((input[i] & 0xc0) != 0x80)
189 *wc |= (input[i] & 0x3f) << ((size - i - 1) * 6);
195 static le16_t* wchar_to_utf16(le16_t* output, wchar_t wc, size_t outsize)
197 if (wc <= 0xffff) /* if character is from BMP */
201 output[0] = cpu_to_le16(wc);
207 output[0] = cpu_to_le16(0xd800 | ((wc >> 10) & 0x3ff));
208 output[1] = cpu_to_le16(0xdc00 | (wc & 0x3ff));
212 int exfat_utf8_to_utf16(le16_t* output, const char* input, size_t outsize,
215 const char* iptr = input;
216 const char* iend = input + insize;
217 le16_t* optr = output;
218 const le16_t* oend = output + outsize;
223 iptr = utf8_to_wchar(iptr, &wc, iend - iptr);
226 exfat_error("illegal UTF-8 sequence");
229 optr = wchar_to_utf16(optr, wc, oend - optr);
232 exfat_error("name is too long");
233 return -ENAMETOOLONG;
240 exfat_error("name is too long");
241 return -ENAMETOOLONG;
243 *optr = cpu_to_le16(0);
247 size_t exfat_utf16_length(const le16_t* str)
251 while (le16_to_cpu(str[i]))