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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> | |
5f60d5f6 | 11 | #include <linux/unaligned.h> |
e2f34481 NJ |
12 | #include "glob.h" |
13 | #include "unicode.h" | |
e2f34481 NJ |
14 | #include "smb_common.h" |
15 | ||
e2f34481 NJ |
16 | /* |
17 | * cifs_mapchar() - convert a host-endian char to proper char in codepage | |
18 | * @target: where converted character should be copied | |
0c180317 | 19 | * @from: host-endian source string |
e2f34481 NJ |
20 | * @cp: codepage to which character should be converted |
21 | * @mapchar: should character be mapped according to mapchars mount option? | |
22 | * | |
23 | * This function handles the conversion of a single character. It is the | |
24 | * responsibility of the caller to ensure that the target buffer is large | |
25 | * enough to hold the result of the conversion (at least NLS_MAX_CHARSET_SIZE). | |
26 | * | |
27 | * Return: string length after conversion | |
28 | */ | |
29 | static int | |
0c180317 | 30 | cifs_mapchar(char *target, const __u16 *from, const struct nls_table *cp, |
070fb21e | 31 | bool mapchar) |
e2f34481 NJ |
32 | { |
33 | int len = 1; | |
0c180317 NJ |
34 | __u16 src_char; |
35 | ||
36 | src_char = *from; | |
e2f34481 NJ |
37 | |
38 | if (!mapchar) | |
39 | goto cp_convert; | |
40 | ||
41 | /* | |
42 | * BB: Cannot handle remapping UNI_SLASH until all the calls to | |
43 | * build_path_from_dentry are modified, as they use slash as | |
44 | * separator. | |
45 | */ | |
46 | switch (src_char) { | |
47 | case UNI_COLON: | |
48 | *target = ':'; | |
49 | break; | |
50 | case UNI_ASTERISK: | |
51 | *target = '*'; | |
52 | break; | |
53 | case UNI_QUESTION: | |
54 | *target = '?'; | |
55 | break; | |
56 | case UNI_PIPE: | |
57 | *target = '|'; | |
58 | break; | |
59 | case UNI_GRTRTHAN: | |
60 | *target = '>'; | |
61 | break; | |
62 | case UNI_LESSTHAN: | |
63 | *target = '<'; | |
64 | break; | |
65 | default: | |
66 | goto cp_convert; | |
67 | } | |
68 | ||
69 | out: | |
70 | return len; | |
71 | ||
72 | cp_convert: | |
73 | len = cp->uni2char(src_char, target, NLS_MAX_CHARSET_SIZE); | |
0c180317 NJ |
74 | if (len <= 0) |
75 | goto surrogate_pair; | |
e2f34481 NJ |
76 | |
77 | goto out; | |
0c180317 NJ |
78 | |
79 | surrogate_pair: | |
80 | /* convert SURROGATE_PAIR and IVS */ | |
81 | if (strcmp(cp->charset, "utf8")) | |
82 | goto unknown; | |
83 | len = utf16s_to_utf8s(from, 3, UTF16_LITTLE_ENDIAN, target, 6); | |
84 | if (len <= 0) | |
85 | goto unknown; | |
86 | return len; | |
87 | ||
88 | unknown: | |
89 | *target = '?'; | |
90 | len = 1; | |
91 | goto out; | |
92 | } | |
93 | ||
94 | /* | |
95 | * smb_utf16_bytes() - compute converted string length | |
96 | * @from: pointer to input string | |
97 | * @maxbytes: input string length | |
98 | * @codepage: destination codepage | |
99 | * | |
100 | * Walk a utf16le string and return the number of bytes that the string will | |
101 | * be after being converted to the given charset, not including any null | |
102 | * termination required. Don't walk past maxbytes in the source buffer. | |
103 | * | |
104 | * Return: string length after conversion | |
105 | */ | |
106 | static int smb_utf16_bytes(const __le16 *from, int maxbytes, | |
107 | const struct nls_table *codepage) | |
108 | { | |
109 | int i, j; | |
110 | int charlen, outlen = 0; | |
111 | int maxwords = maxbytes / 2; | |
112 | char tmp[NLS_MAX_CHARSET_SIZE]; | |
113 | __u16 ftmp[3]; | |
114 | ||
115 | for (i = 0; i < maxwords; i++) { | |
116 | ftmp[0] = get_unaligned_le16(&from[i]); | |
117 | if (ftmp[0] == 0) | |
118 | break; | |
119 | for (j = 1; j <= 2; j++) { | |
120 | if (i + j < maxwords) | |
121 | ftmp[j] = get_unaligned_le16(&from[i + j]); | |
122 | else | |
123 | ftmp[j] = 0; | |
124 | } | |
125 | ||
126 | charlen = cifs_mapchar(tmp, ftmp, codepage, 0); | |
127 | if (charlen > 0) | |
128 | outlen += charlen; | |
129 | else | |
130 | outlen++; | |
131 | } | |
132 | ||
133 | return outlen; | |
e2f34481 NJ |
134 | } |
135 | ||
e2f34481 NJ |
136 | /* |
137 | * smb_from_utf16() - convert utf16le string to local charset | |
138 | * @to: destination buffer | |
139 | * @from: source buffer | |
140 | * @tolen: destination buffer size (in bytes) | |
141 | * @fromlen: source buffer size (in bytes) | |
142 | * @codepage: codepage to which characters should be converted | |
143 | * @mapchar: should characters be remapped according to the mapchars option? | |
144 | * | |
145 | * Convert a little-endian utf16le string (as sent by the server) to a string | |
146 | * in the provided codepage. The tolen and fromlen parameters are to ensure | |
147 | * that the code doesn't walk off of the end of the buffer (which is always | |
148 | * a danger if the alignment of the source buffer is off). The destination | |
149 | * string is always properly null terminated and fits in the destination | |
150 | * buffer. Returns the length of the destination string in bytes (including | |
151 | * null terminator). | |
152 | * | |
153 | * Note that some windows versions actually send multiword UTF-16 characters | |
154 | * instead of straight UTF16-2. The linux nls routines however aren't able to | |
155 | * deal with those characters properly. In the event that we get some of | |
156 | * those characters, they won't be translated properly. | |
157 | * | |
158 | * Return: string length after conversion | |
159 | */ | |
64b39f4a | 160 | static int smb_from_utf16(char *to, const __le16 *from, int tolen, int fromlen, |
070fb21e | 161 | const struct nls_table *codepage, bool mapchar) |
e2f34481 | 162 | { |
0c180317 | 163 | int i, j, charlen, safelen; |
e2f34481 NJ |
164 | int outlen = 0; |
165 | int nullsize = nls_nullsize(codepage); | |
166 | int fromwords = fromlen / 2; | |
167 | char tmp[NLS_MAX_CHARSET_SIZE]; | |
0c180317 | 168 | __u16 ftmp[3]; /* ftmp[3] = 3array x 2bytes = 6bytes UTF-16 */ |
e2f34481 NJ |
169 | |
170 | /* | |
171 | * because the chars can be of varying widths, we need to take care | |
172 | * not to overflow the destination buffer when we get close to the | |
173 | * end of it. Until we get to this offset, we don't need to check | |
174 | * for overflow however. | |
175 | */ | |
176 | safelen = tolen - (NLS_MAX_CHARSET_SIZE + nullsize); | |
177 | ||
178 | for (i = 0; i < fromwords; i++) { | |
0c180317 NJ |
179 | ftmp[0] = get_unaligned_le16(&from[i]); |
180 | if (ftmp[0] == 0) | |
e2f34481 | 181 | break; |
0c180317 NJ |
182 | for (j = 1; j <= 2; j++) { |
183 | if (i + j < fromwords) | |
184 | ftmp[j] = get_unaligned_le16(&from[i + j]); | |
185 | else | |
186 | ftmp[j] = 0; | |
187 | } | |
e2f34481 NJ |
188 | |
189 | /* | |
190 | * check to see if converting this character might make the | |
191 | * conversion bleed into the null terminator | |
192 | */ | |
193 | if (outlen >= safelen) { | |
194 | charlen = cifs_mapchar(tmp, ftmp, codepage, mapchar); | |
195 | if ((outlen + charlen) > (tolen - nullsize)) | |
196 | break; | |
197 | } | |
198 | ||
199 | /* put converted char into 'to' buffer */ | |
200 | charlen = cifs_mapchar(&to[outlen], ftmp, codepage, mapchar); | |
201 | outlen += charlen; | |
0c180317 NJ |
202 | |
203 | /* | |
204 | * charlen (=bytes of UTF-8 for 1 character) | |
205 | * 4bytes UTF-8(surrogate pair) is charlen=4 | |
206 | * (4bytes UTF-16 code) | |
207 | * 7-8bytes UTF-8(IVS) is charlen=3+4 or 4+4 | |
208 | * (2 UTF-8 pairs divided to 2 UTF-16 pairs) | |
209 | */ | |
210 | if (charlen == 4) | |
211 | i++; | |
212 | else if (charlen >= 5) | |
213 | /* 5-6bytes UTF-8 */ | |
214 | i += 2; | |
e2f34481 NJ |
215 | } |
216 | ||
217 | /* properly null-terminate string */ | |
218 | for (i = 0; i < nullsize; i++) | |
219 | to[outlen++] = 0; | |
220 | ||
221 | return outlen; | |
222 | } | |
223 | ||
224 | /* | |
225 | * smb_strtoUTF16() - Convert character string to unicode string | |
226 | * @to: destination buffer | |
227 | * @from: source buffer | |
228 | * @len: destination buffer size (in bytes) | |
229 | * @codepage: codepage to which characters should be converted | |
230 | * | |
231 | * Return: string length after conversion | |
232 | */ | |
64b39f4a | 233 | int smb_strtoUTF16(__le16 *to, const char *from, int len, |
070fb21e | 234 | const struct nls_table *codepage) |
e2f34481 NJ |
235 | { |
236 | int charlen; | |
237 | int i; | |
238 | wchar_t wchar_to; /* needed to quiet sparse */ | |
239 | ||
240 | /* special case for utf8 to handle no plane0 chars */ | |
241 | if (!strcmp(codepage->charset, "utf8")) { | |
242 | /* | |
243 | * convert utf8 -> utf16, we assume we have enough space | |
244 | * as caller should have assumed conversion does not overflow | |
245 | * in destination len is length in wchar_t units (16bits) | |
246 | */ | |
247 | i = utf8s_to_utf16s(from, len, UTF16_LITTLE_ENDIAN, | |
070fb21e | 248 | (wchar_t *)to, len); |
e2f34481 NJ |
249 | |
250 | /* if success terminate and exit */ | |
251 | if (i >= 0) | |
252 | goto success; | |
253 | /* | |
254 | * if fails fall back to UCS encoding as this | |
255 | * function should not return negative values | |
256 | * currently can fail only if source contains | |
257 | * invalid encoded characters | |
258 | */ | |
259 | } | |
260 | ||
261 | for (i = 0; len > 0 && *from; i++, from += charlen, len -= charlen) { | |
262 | charlen = codepage->char2uni(from, len, &wchar_to); | |
263 | if (charlen < 1) { | |
264 | /* A question mark */ | |
265 | wchar_to = 0x003f; | |
266 | charlen = 1; | |
267 | } | |
268 | put_unaligned_le16(wchar_to, &to[i]); | |
269 | } | |
270 | ||
271 | success: | |
272 | put_unaligned_le16(0, &to[i]); | |
273 | return i; | |
274 | } | |
275 | ||
276 | /* | |
277 | * smb_strndup_from_utf16() - copy a string from wire format to the local | |
278 | * codepage | |
279 | * @src: source string | |
280 | * @maxlen: don't walk past this many bytes in the source string | |
281 | * @is_unicode: is this a unicode string? | |
282 | * @codepage: destination codepage | |
283 | * | |
284 | * Take a string given by the server, convert it to the local codepage and | |
285 | * put it in a new buffer. Returns a pointer to the new string or NULL on | |
286 | * error. | |
287 | * | |
288 | * Return: destination string buffer or error ptr | |
289 | */ | |
64b39f4a | 290 | char *smb_strndup_from_utf16(const char *src, const int maxlen, |
070fb21e NJ |
291 | const bool is_unicode, |
292 | const struct nls_table *codepage) | |
e2f34481 NJ |
293 | { |
294 | int len, ret; | |
295 | char *dst; | |
296 | ||
297 | if (is_unicode) { | |
64b39f4a | 298 | len = smb_utf16_bytes((__le16 *)src, maxlen, codepage); |
e2f34481 NJ |
299 | len += nls_nullsize(codepage); |
300 | dst = kmalloc(len, GFP_KERNEL); | |
301 | if (!dst) | |
302 | return ERR_PTR(-ENOMEM); | |
64b39f4a | 303 | ret = smb_from_utf16(dst, (__le16 *)src, len, maxlen, codepage, |
070fb21e | 304 | false); |
e2f34481 NJ |
305 | if (ret < 0) { |
306 | kfree(dst); | |
307 | return ERR_PTR(-EINVAL); | |
308 | } | |
309 | } else { | |
310 | len = strnlen(src, maxlen); | |
311 | len++; | |
312 | dst = kmalloc(len, GFP_KERNEL); | |
313 | if (!dst) | |
314 | return ERR_PTR(-ENOMEM); | |
315 | strscpy(dst, src, len); | |
316 | } | |
317 | ||
318 | return dst; | |
319 | } | |
320 | ||
321 | /* | |
322 | * Convert 16 bit Unicode pathname to wire format from string in current code | |
323 | * page. Conversion may involve remapping up the six characters that are | |
324 | * only legal in POSIX-like OS (if they are present in the string). Path | |
325 | * names are little endian 16 bit Unicode on the wire | |
326 | */ | |
327 | /* | |
328 | * smbConvertToUTF16() - convert string from local charset to utf16 | |
329 | * @target: destination buffer | |
330 | * @source: source buffer | |
331 | * @srclen: source buffer size (in bytes) | |
332 | * @cp: codepage to which characters should be converted | |
333 | * @mapchar: should characters be remapped according to the mapchars option? | |
334 | * | |
335 | * Convert 16 bit Unicode pathname to wire format from string in current code | |
336 | * page. Conversion may involve remapping up the six characters that are | |
337 | * only legal in POSIX-like OS (if they are present in the string). Path | |
338 | * names are little endian 16 bit Unicode on the wire | |
339 | * | |
340 | * Return: char length after conversion | |
341 | */ | |
64b39f4a | 342 | int smbConvertToUTF16(__le16 *target, const char *source, int srclen, |
070fb21e | 343 | const struct nls_table *cp, int mapchars) |
e2f34481 NJ |
344 | { |
345 | int i, j, charlen; | |
346 | char src_char; | |
347 | __le16 dst_char; | |
348 | wchar_t tmp; | |
0c180317 NJ |
349 | wchar_t wchar_to[6]; /* UTF-16 */ |
350 | int ret; | |
351 | unicode_t u; | |
e2f34481 NJ |
352 | |
353 | if (!mapchars) | |
354 | return smb_strtoUTF16(target, source, srclen, cp); | |
355 | ||
356 | for (i = 0, j = 0; i < srclen; j++) { | |
357 | src_char = source[i]; | |
358 | charlen = 1; | |
359 | switch (src_char) { | |
360 | case 0: | |
361 | put_unaligned(0, &target[j]); | |
362 | return j; | |
363 | case ':': | |
364 | dst_char = cpu_to_le16(UNI_COLON); | |
365 | break; | |
366 | case '*': | |
367 | dst_char = cpu_to_le16(UNI_ASTERISK); | |
368 | break; | |
369 | case '?': | |
370 | dst_char = cpu_to_le16(UNI_QUESTION); | |
371 | break; | |
372 | case '<': | |
373 | dst_char = cpu_to_le16(UNI_LESSTHAN); | |
374 | break; | |
375 | case '>': | |
376 | dst_char = cpu_to_le16(UNI_GRTRTHAN); | |
377 | break; | |
378 | case '|': | |
379 | dst_char = cpu_to_le16(UNI_PIPE); | |
380 | break; | |
381 | /* | |
382 | * FIXME: We can not handle remapping backslash (UNI_SLASH) | |
383 | * until all the calls to build_path_from_dentry are modified, | |
384 | * as they use backslash as separator. | |
385 | */ | |
386 | default: | |
387 | charlen = cp->char2uni(source + i, srclen - i, &tmp); | |
388 | dst_char = cpu_to_le16(tmp); | |
389 | ||
390 | /* | |
391 | * if no match, use question mark, which at least in | |
392 | * some cases serves as wild card | |
393 | */ | |
0c180317 NJ |
394 | if (charlen > 0) |
395 | goto ctoUTF16; | |
396 | ||
397 | /* convert SURROGATE_PAIR */ | |
398 | if (strcmp(cp->charset, "utf8")) | |
399 | goto unknown; | |
400 | if (*(source + i) & 0x80) { | |
401 | charlen = utf8_to_utf32(source + i, 6, &u); | |
402 | if (charlen < 0) | |
403 | goto unknown; | |
404 | } else | |
405 | goto unknown; | |
406 | ret = utf8s_to_utf16s(source + i, charlen, | |
407 | UTF16_LITTLE_ENDIAN, | |
408 | wchar_to, 6); | |
409 | if (ret < 0) | |
410 | goto unknown; | |
411 | ||
412 | i += charlen; | |
413 | dst_char = cpu_to_le16(*wchar_to); | |
414 | if (charlen <= 3) | |
415 | /* 1-3bytes UTF-8 to 2bytes UTF-16 */ | |
416 | put_unaligned(dst_char, &target[j]); | |
417 | else if (charlen == 4) { | |
418 | /* | |
419 | * 4bytes UTF-8(surrogate pair) to 4bytes UTF-16 | |
420 | * 7-8bytes UTF-8(IVS) divided to 2 UTF-16 | |
421 | * (charlen=3+4 or 4+4) | |
422 | */ | |
423 | put_unaligned(dst_char, &target[j]); | |
424 | dst_char = cpu_to_le16(*(wchar_to + 1)); | |
425 | j++; | |
426 | put_unaligned(dst_char, &target[j]); | |
427 | } else if (charlen >= 5) { | |
428 | /* 5-6bytes UTF-8 to 6bytes UTF-16 */ | |
429 | put_unaligned(dst_char, &target[j]); | |
430 | dst_char = cpu_to_le16(*(wchar_to + 1)); | |
431 | j++; | |
432 | put_unaligned(dst_char, &target[j]); | |
433 | dst_char = cpu_to_le16(*(wchar_to + 2)); | |
434 | j++; | |
435 | put_unaligned(dst_char, &target[j]); | |
e2f34481 | 436 | } |
0c180317 NJ |
437 | continue; |
438 | ||
439 | unknown: | |
440 | dst_char = cpu_to_le16(0x003f); | |
441 | charlen = 1; | |
e2f34481 | 442 | } |
0c180317 NJ |
443 | |
444 | ctoUTF16: | |
e2f34481 NJ |
445 | /* |
446 | * character may take more than one byte in the source string, | |
447 | * but will take exactly two bytes in the target string | |
448 | */ | |
449 | i += charlen; | |
450 | put_unaligned(dst_char, &target[j]); | |
451 | } | |
452 | ||
453 | return j; | |
454 | } |