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e2f34481 NJ |
1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* | |
3 | * Some of the source code in this file came from fs/cifs/cifs_unicode.c | |
4 | * | |
5 | * Copyright (c) International Business Machines Corp., 2000,2009 | |
6 | * Modified by Steve French (sfrench@us.ibm.com) | |
7 | * Modified by Namjae Jeon (linkinjeon@kernel.org) | |
8 | */ | |
9 | #include <linux/fs.h> | |
10 | #include <linux/slab.h> | |
11 | #include <asm/unaligned.h> | |
12 | #include "glob.h" | |
13 | #include "unicode.h" | |
14 | #include "uniupr.h" | |
15 | #include "smb_common.h" | |
16 | ||
17 | /* | |
18 | * smb_utf16_bytes() - how long will a string be after conversion? | |
19 | * @from: pointer to input string | |
20 | * @maxbytes: don't go past this many bytes of input string | |
21 | * @codepage: destination codepage | |
22 | * | |
23 | * Walk a utf16le string and return the number of bytes that the string will | |
24 | * be after being converted to the given charset, not including any null | |
25 | * termination required. Don't walk past maxbytes in the source buffer. | |
26 | * | |
27 | * Return: string length after conversion | |
28 | */ | |
64b39f4a | 29 | static int smb_utf16_bytes(const __le16 *from, int maxbytes, |
070fb21e | 30 | const struct nls_table *codepage) |
e2f34481 NJ |
31 | { |
32 | int i; | |
33 | int charlen, outlen = 0; | |
34 | int maxwords = maxbytes / 2; | |
35 | char tmp[NLS_MAX_CHARSET_SIZE]; | |
36 | __u16 ftmp; | |
37 | ||
38 | for (i = 0; i < maxwords; i++) { | |
39 | ftmp = get_unaligned_le16(&from[i]); | |
40 | if (ftmp == 0) | |
41 | break; | |
42 | ||
43 | charlen = codepage->uni2char(ftmp, tmp, NLS_MAX_CHARSET_SIZE); | |
44 | if (charlen > 0) | |
45 | outlen += charlen; | |
46 | else | |
47 | outlen++; | |
48 | } | |
49 | ||
50 | return outlen; | |
51 | } | |
52 | ||
53 | /* | |
54 | * cifs_mapchar() - convert a host-endian char to proper char in codepage | |
55 | * @target: where converted character should be copied | |
56 | * @src_char: 2 byte host-endian source character | |
57 | * @cp: codepage to which character should be converted | |
58 | * @mapchar: should character be mapped according to mapchars mount option? | |
59 | * | |
60 | * This function handles the conversion of a single character. It is the | |
61 | * responsibility of the caller to ensure that the target buffer is large | |
62 | * enough to hold the result of the conversion (at least NLS_MAX_CHARSET_SIZE). | |
63 | * | |
64 | * Return: string length after conversion | |
65 | */ | |
66 | static int | |
67 | cifs_mapchar(char *target, const __u16 src_char, const struct nls_table *cp, | |
070fb21e | 68 | bool mapchar) |
e2f34481 NJ |
69 | { |
70 | int len = 1; | |
71 | ||
72 | if (!mapchar) | |
73 | goto cp_convert; | |
74 | ||
75 | /* | |
76 | * BB: Cannot handle remapping UNI_SLASH until all the calls to | |
77 | * build_path_from_dentry are modified, as they use slash as | |
78 | * separator. | |
79 | */ | |
80 | switch (src_char) { | |
81 | case UNI_COLON: | |
82 | *target = ':'; | |
83 | break; | |
84 | case UNI_ASTERISK: | |
85 | *target = '*'; | |
86 | break; | |
87 | case UNI_QUESTION: | |
88 | *target = '?'; | |
89 | break; | |
90 | case UNI_PIPE: | |
91 | *target = '|'; | |
92 | break; | |
93 | case UNI_GRTRTHAN: | |
94 | *target = '>'; | |
95 | break; | |
96 | case UNI_LESSTHAN: | |
97 | *target = '<'; | |
98 | break; | |
99 | default: | |
100 | goto cp_convert; | |
101 | } | |
102 | ||
103 | out: | |
104 | return len; | |
105 | ||
106 | cp_convert: | |
107 | len = cp->uni2char(src_char, target, NLS_MAX_CHARSET_SIZE); | |
108 | if (len <= 0) { | |
109 | *target = '?'; | |
110 | len = 1; | |
111 | } | |
112 | ||
113 | goto out; | |
114 | } | |
115 | ||
e2f34481 NJ |
116 | /* |
117 | * smb_from_utf16() - convert utf16le string to local charset | |
118 | * @to: destination buffer | |
119 | * @from: source buffer | |
120 | * @tolen: destination buffer size (in bytes) | |
121 | * @fromlen: source buffer size (in bytes) | |
122 | * @codepage: codepage to which characters should be converted | |
123 | * @mapchar: should characters be remapped according to the mapchars option? | |
124 | * | |
125 | * Convert a little-endian utf16le string (as sent by the server) to a string | |
126 | * in the provided codepage. The tolen and fromlen parameters are to ensure | |
127 | * that the code doesn't walk off of the end of the buffer (which is always | |
128 | * a danger if the alignment of the source buffer is off). The destination | |
129 | * string is always properly null terminated and fits in the destination | |
130 | * buffer. Returns the length of the destination string in bytes (including | |
131 | * null terminator). | |
132 | * | |
133 | * Note that some windows versions actually send multiword UTF-16 characters | |
134 | * instead of straight UTF16-2. The linux nls routines however aren't able to | |
135 | * deal with those characters properly. In the event that we get some of | |
136 | * those characters, they won't be translated properly. | |
137 | * | |
138 | * Return: string length after conversion | |
139 | */ | |
64b39f4a | 140 | static int smb_from_utf16(char *to, const __le16 *from, int tolen, int fromlen, |
070fb21e | 141 | const struct nls_table *codepage, bool mapchar) |
e2f34481 NJ |
142 | { |
143 | int i, charlen, safelen; | |
144 | int outlen = 0; | |
145 | int nullsize = nls_nullsize(codepage); | |
146 | int fromwords = fromlen / 2; | |
147 | char tmp[NLS_MAX_CHARSET_SIZE]; | |
148 | __u16 ftmp; | |
149 | ||
150 | /* | |
151 | * because the chars can be of varying widths, we need to take care | |
152 | * not to overflow the destination buffer when we get close to the | |
153 | * end of it. Until we get to this offset, we don't need to check | |
154 | * for overflow however. | |
155 | */ | |
156 | safelen = tolen - (NLS_MAX_CHARSET_SIZE + nullsize); | |
157 | ||
158 | for (i = 0; i < fromwords; i++) { | |
159 | ftmp = get_unaligned_le16(&from[i]); | |
160 | if (ftmp == 0) | |
161 | break; | |
162 | ||
163 | /* | |
164 | * check to see if converting this character might make the | |
165 | * conversion bleed into the null terminator | |
166 | */ | |
167 | if (outlen >= safelen) { | |
168 | charlen = cifs_mapchar(tmp, ftmp, codepage, mapchar); | |
169 | if ((outlen + charlen) > (tolen - nullsize)) | |
170 | break; | |
171 | } | |
172 | ||
173 | /* put converted char into 'to' buffer */ | |
174 | charlen = cifs_mapchar(&to[outlen], ftmp, codepage, mapchar); | |
175 | outlen += charlen; | |
176 | } | |
177 | ||
178 | /* properly null-terminate string */ | |
179 | for (i = 0; i < nullsize; i++) | |
180 | to[outlen++] = 0; | |
181 | ||
182 | return outlen; | |
183 | } | |
184 | ||
185 | /* | |
186 | * smb_strtoUTF16() - Convert character string to unicode string | |
187 | * @to: destination buffer | |
188 | * @from: source buffer | |
189 | * @len: destination buffer size (in bytes) | |
190 | * @codepage: codepage to which characters should be converted | |
191 | * | |
192 | * Return: string length after conversion | |
193 | */ | |
64b39f4a | 194 | int smb_strtoUTF16(__le16 *to, const char *from, int len, |
070fb21e | 195 | const struct nls_table *codepage) |
e2f34481 NJ |
196 | { |
197 | int charlen; | |
198 | int i; | |
199 | wchar_t wchar_to; /* needed to quiet sparse */ | |
200 | ||
201 | /* special case for utf8 to handle no plane0 chars */ | |
202 | if (!strcmp(codepage->charset, "utf8")) { | |
203 | /* | |
204 | * convert utf8 -> utf16, we assume we have enough space | |
205 | * as caller should have assumed conversion does not overflow | |
206 | * in destination len is length in wchar_t units (16bits) | |
207 | */ | |
208 | i = utf8s_to_utf16s(from, len, UTF16_LITTLE_ENDIAN, | |
070fb21e | 209 | (wchar_t *)to, len); |
e2f34481 NJ |
210 | |
211 | /* if success terminate and exit */ | |
212 | if (i >= 0) | |
213 | goto success; | |
214 | /* | |
215 | * if fails fall back to UCS encoding as this | |
216 | * function should not return negative values | |
217 | * currently can fail only if source contains | |
218 | * invalid encoded characters | |
219 | */ | |
220 | } | |
221 | ||
222 | for (i = 0; len > 0 && *from; i++, from += charlen, len -= charlen) { | |
223 | charlen = codepage->char2uni(from, len, &wchar_to); | |
224 | if (charlen < 1) { | |
225 | /* A question mark */ | |
226 | wchar_to = 0x003f; | |
227 | charlen = 1; | |
228 | } | |
229 | put_unaligned_le16(wchar_to, &to[i]); | |
230 | } | |
231 | ||
232 | success: | |
233 | put_unaligned_le16(0, &to[i]); | |
234 | return i; | |
235 | } | |
236 | ||
237 | /* | |
238 | * smb_strndup_from_utf16() - copy a string from wire format to the local | |
239 | * codepage | |
240 | * @src: source string | |
241 | * @maxlen: don't walk past this many bytes in the source string | |
242 | * @is_unicode: is this a unicode string? | |
243 | * @codepage: destination codepage | |
244 | * | |
245 | * Take a string given by the server, convert it to the local codepage and | |
246 | * put it in a new buffer. Returns a pointer to the new string or NULL on | |
247 | * error. | |
248 | * | |
249 | * Return: destination string buffer or error ptr | |
250 | */ | |
64b39f4a | 251 | char *smb_strndup_from_utf16(const char *src, const int maxlen, |
070fb21e NJ |
252 | const bool is_unicode, |
253 | const struct nls_table *codepage) | |
e2f34481 NJ |
254 | { |
255 | int len, ret; | |
256 | char *dst; | |
257 | ||
258 | if (is_unicode) { | |
64b39f4a | 259 | len = smb_utf16_bytes((__le16 *)src, maxlen, codepage); |
e2f34481 NJ |
260 | len += nls_nullsize(codepage); |
261 | dst = kmalloc(len, GFP_KERNEL); | |
262 | if (!dst) | |
263 | return ERR_PTR(-ENOMEM); | |
64b39f4a | 264 | ret = smb_from_utf16(dst, (__le16 *)src, len, maxlen, codepage, |
070fb21e | 265 | false); |
e2f34481 NJ |
266 | if (ret < 0) { |
267 | kfree(dst); | |
268 | return ERR_PTR(-EINVAL); | |
269 | } | |
270 | } else { | |
271 | len = strnlen(src, maxlen); | |
272 | len++; | |
273 | dst = kmalloc(len, GFP_KERNEL); | |
274 | if (!dst) | |
275 | return ERR_PTR(-ENOMEM); | |
276 | strscpy(dst, src, len); | |
277 | } | |
278 | ||
279 | return dst; | |
280 | } | |
281 | ||
282 | /* | |
283 | * Convert 16 bit Unicode pathname to wire format from string in current code | |
284 | * page. Conversion may involve remapping up the six characters that are | |
285 | * only legal in POSIX-like OS (if they are present in the string). Path | |
286 | * names are little endian 16 bit Unicode on the wire | |
287 | */ | |
288 | /* | |
289 | * smbConvertToUTF16() - convert string from local charset to utf16 | |
290 | * @target: destination buffer | |
291 | * @source: source buffer | |
292 | * @srclen: source buffer size (in bytes) | |
293 | * @cp: codepage to which characters should be converted | |
294 | * @mapchar: should characters be remapped according to the mapchars option? | |
295 | * | |
296 | * Convert 16 bit Unicode pathname to wire format from string in current code | |
297 | * page. Conversion may involve remapping up the six characters that are | |
298 | * only legal in POSIX-like OS (if they are present in the string). Path | |
299 | * names are little endian 16 bit Unicode on the wire | |
300 | * | |
301 | * Return: char length after conversion | |
302 | */ | |
64b39f4a | 303 | int smbConvertToUTF16(__le16 *target, const char *source, int srclen, |
070fb21e | 304 | const struct nls_table *cp, int mapchars) |
e2f34481 NJ |
305 | { |
306 | int i, j, charlen; | |
307 | char src_char; | |
308 | __le16 dst_char; | |
309 | wchar_t tmp; | |
310 | ||
311 | if (!mapchars) | |
312 | return smb_strtoUTF16(target, source, srclen, cp); | |
313 | ||
314 | for (i = 0, j = 0; i < srclen; j++) { | |
315 | src_char = source[i]; | |
316 | charlen = 1; | |
317 | switch (src_char) { | |
318 | case 0: | |
319 | put_unaligned(0, &target[j]); | |
320 | return j; | |
321 | case ':': | |
322 | dst_char = cpu_to_le16(UNI_COLON); | |
323 | break; | |
324 | case '*': | |
325 | dst_char = cpu_to_le16(UNI_ASTERISK); | |
326 | break; | |
327 | case '?': | |
328 | dst_char = cpu_to_le16(UNI_QUESTION); | |
329 | break; | |
330 | case '<': | |
331 | dst_char = cpu_to_le16(UNI_LESSTHAN); | |
332 | break; | |
333 | case '>': | |
334 | dst_char = cpu_to_le16(UNI_GRTRTHAN); | |
335 | break; | |
336 | case '|': | |
337 | dst_char = cpu_to_le16(UNI_PIPE); | |
338 | break; | |
339 | /* | |
340 | * FIXME: We can not handle remapping backslash (UNI_SLASH) | |
341 | * until all the calls to build_path_from_dentry are modified, | |
342 | * as they use backslash as separator. | |
343 | */ | |
344 | default: | |
345 | charlen = cp->char2uni(source + i, srclen - i, &tmp); | |
346 | dst_char = cpu_to_le16(tmp); | |
347 | ||
348 | /* | |
349 | * if no match, use question mark, which at least in | |
350 | * some cases serves as wild card | |
351 | */ | |
352 | if (charlen < 1) { | |
353 | dst_char = cpu_to_le16(0x003f); | |
354 | charlen = 1; | |
355 | } | |
356 | } | |
357 | /* | |
358 | * character may take more than one byte in the source string, | |
359 | * but will take exactly two bytes in the target string | |
360 | */ | |
361 | i += charlen; | |
362 | put_unaligned(dst_char, &target[j]); | |
363 | } | |
364 | ||
365 | return j; | |
366 | } |