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1/*
2 * fs/cifs/cifs_unicode.c
3 *
4 * Copyright (c) International Business Machines Corp., 2000,2009
5 * Modified by Steve French (sfrench@us.ibm.com)
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
15 * the GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21#include <linux/fs.h>
22#include <linux/slab.h>
23#include "cifs_fs_sb.h"
24#include "cifs_unicode.h"
25#include "cifs_uniupr.h"
26#include "cifspdu.h"
27#include "cifsglob.h"
28#include "cifs_debug.h"
29
30int cifs_remap(struct cifs_sb_info *cifs_sb)
31{
32 int map_type;
33
34 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SFM_CHR)
35 map_type = SFM_MAP_UNI_RSVD;
36 else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR)
37 map_type = SFU_MAP_UNI_RSVD;
38 else
39 map_type = NO_MAP_UNI_RSVD;
40
41 return map_type;
42}
43
44/* Convert character using the SFU - "Services for Unix" remapping range */
45static bool
46convert_sfu_char(const __u16 src_char, char *target)
47{
48 /*
49 * BB: Cannot handle remapping UNI_SLASH until all the calls to
50 * build_path_from_dentry are modified, as they use slash as
51 * separator.
52 */
53 switch (src_char) {
54 case UNI_COLON:
55 *target = ':';
56 break;
57 case UNI_ASTERISK:
58 *target = '*';
59 break;
60 case UNI_QUESTION:
61 *target = '?';
62 break;
63 case UNI_PIPE:
64 *target = '|';
65 break;
66 case UNI_GRTRTHAN:
67 *target = '>';
68 break;
69 case UNI_LESSTHAN:
70 *target = '<';
71 break;
72 default:
73 return false;
74 }
75 return true;
76}
77
78/* Convert character using the SFM - "Services for Mac" remapping range */
79static bool
80convert_sfm_char(const __u16 src_char, char *target)
81{
82 if (src_char >= 0xF001 && src_char <= 0xF01F) {
83 *target = src_char - 0xF000;
84 return true;
85 }
86 switch (src_char) {
87 case SFM_COLON:
88 *target = ':';
89 break;
90 case SFM_DOUBLEQUOTE:
91 *target = '"';
92 break;
93 case SFM_ASTERISK:
94 *target = '*';
95 break;
96 case SFM_QUESTION:
97 *target = '?';
98 break;
99 case SFM_PIPE:
100 *target = '|';
101 break;
102 case SFM_GRTRTHAN:
103 *target = '>';
104 break;
105 case SFM_LESSTHAN:
106 *target = '<';
107 break;
108 case SFM_SLASH:
109 *target = '\\';
110 break;
111 case SFM_SPACE:
112 *target = ' ';
113 break;
114 case SFM_PERIOD:
115 *target = '.';
116 break;
117 default:
118 return false;
119 }
120 return true;
121}
122
123
124/*
125 * cifs_mapchar - convert a host-endian char to proper char in codepage
126 * @target - where converted character should be copied
127 * @src_char - 2 byte host-endian source character
128 * @cp - codepage to which character should be converted
129 * @map_type - How should the 7 NTFS/SMB reserved characters be mapped to UCS2?
130 *
131 * This function handles the conversion of a single character. It is the
132 * responsibility of the caller to ensure that the target buffer is large
133 * enough to hold the result of the conversion (at least NLS_MAX_CHARSET_SIZE).
134 */
135static int
136cifs_mapchar(char *target, const __u16 *from, const struct nls_table *cp,
137 int maptype)
138{
139 int len = 1;
140 __u16 src_char;
141
142 src_char = *from;
143
144 if ((maptype == SFM_MAP_UNI_RSVD) && convert_sfm_char(src_char, target))
145 return len;
146 else if ((maptype == SFU_MAP_UNI_RSVD) &&
147 convert_sfu_char(src_char, target))
148 return len;
149
150 /* if character not one of seven in special remap set */
151 len = cp->uni2char(src_char, target, NLS_MAX_CHARSET_SIZE);
152 if (len <= 0)
153 goto surrogate_pair;
154
155 return len;
156
157surrogate_pair:
158 /* convert SURROGATE_PAIR and IVS */
159 if (strcmp(cp->charset, "utf8"))
160 goto unknown;
161 len = utf16s_to_utf8s(from, 3, UTF16_LITTLE_ENDIAN, target, 6);
162 if (len <= 0)
163 goto unknown;
164 return len;
165
166unknown:
167 *target = '?';
168 len = 1;
169 return len;
170}
171
172/*
173 * cifs_from_utf16 - convert utf16le string to local charset
174 * @to - destination buffer
175 * @from - source buffer
176 * @tolen - destination buffer size (in bytes)
177 * @fromlen - source buffer size (in bytes)
178 * @codepage - codepage to which characters should be converted
179 * @mapchar - should characters be remapped according to the mapchars option?
180 *
181 * Convert a little-endian utf16le string (as sent by the server) to a string
182 * in the provided codepage. The tolen and fromlen parameters are to ensure
183 * that the code doesn't walk off of the end of the buffer (which is always
184 * a danger if the alignment of the source buffer is off). The destination
185 * string is always properly null terminated and fits in the destination
186 * buffer. Returns the length of the destination string in bytes (including
187 * null terminator).
188 *
189 * Note that some windows versions actually send multiword UTF-16 characters
190 * instead of straight UTF16-2. The linux nls routines however aren't able to
191 * deal with those characters properly. In the event that we get some of
192 * those characters, they won't be translated properly.
193 */
194int
195cifs_from_utf16(char *to, const __le16 *from, int tolen, int fromlen,
196 const struct nls_table *codepage, int map_type)
197{
198 int i, charlen, safelen;
199 int outlen = 0;
200 int nullsize = nls_nullsize(codepage);
201 int fromwords = fromlen / 2;
202 char tmp[NLS_MAX_CHARSET_SIZE];
203 __u16 ftmp[3]; /* ftmp[3] = 3array x 2bytes = 6bytes UTF-16 */
204
205 /*
206 * because the chars can be of varying widths, we need to take care
207 * not to overflow the destination buffer when we get close to the
208 * end of it. Until we get to this offset, we don't need to check
209 * for overflow however.
210 */
211 safelen = tolen - (NLS_MAX_CHARSET_SIZE + nullsize);
212
213 for (i = 0; i < fromwords; i++) {
214 ftmp[0] = get_unaligned_le16(&from[i]);
215 if (ftmp[0] == 0)
216 break;
217 if (i + 1 < fromwords)
218 ftmp[1] = get_unaligned_le16(&from[i + 1]);
219 else
220 ftmp[1] = 0;
221 if (i + 2 < fromwords)
222 ftmp[2] = get_unaligned_le16(&from[i + 2]);
223 else
224 ftmp[2] = 0;
225
226 /*
227 * check to see if converting this character might make the
228 * conversion bleed into the null terminator
229 */
230 if (outlen >= safelen) {
231 charlen = cifs_mapchar(tmp, ftmp, codepage, map_type);
232 if ((outlen + charlen) > (tolen - nullsize))
233 break;
234 }
235
236 /* put converted char into 'to' buffer */
237 charlen = cifs_mapchar(&to[outlen], ftmp, codepage, map_type);
238 outlen += charlen;
239
240 /* charlen (=bytes of UTF-8 for 1 character)
241 * 4bytes UTF-8(surrogate pair) is charlen=4
242 * (4bytes UTF-16 code)
243 * 7-8bytes UTF-8(IVS) is charlen=3+4 or 4+4
244 * (2 UTF-8 pairs divided to 2 UTF-16 pairs) */
245 if (charlen == 4)
246 i++;
247 else if (charlen >= 5)
248 /* 5-6bytes UTF-8 */
249 i += 2;
250 }
251
252 /* properly null-terminate string */
253 for (i = 0; i < nullsize; i++)
254 to[outlen++] = 0;
255
256 return outlen;
257}
258
259/*
260 * NAME: cifs_strtoUTF16()
261 *
262 * FUNCTION: Convert character string to unicode string
263 *
264 */
265int
266cifs_strtoUTF16(__le16 *to, const char *from, int len,
267 const struct nls_table *codepage)
268{
269 int charlen;
270 int i;
271 wchar_t wchar_to; /* needed to quiet sparse */
272
273 /* special case for utf8 to handle no plane0 chars */
274 if (!strcmp(codepage->charset, "utf8")) {
275 /*
276 * convert utf8 -> utf16, we assume we have enough space
277 * as caller should have assumed conversion does not overflow
278 * in destination len is length in wchar_t units (16bits)
279 */
280 i = utf8s_to_utf16s(from, len, UTF16_LITTLE_ENDIAN,
281 (wchar_t *) to, len);
282
283 /* if success terminate and exit */
284 if (i >= 0)
285 goto success;
286 /*
287 * if fails fall back to UCS encoding as this
288 * function should not return negative values
289 * currently can fail only if source contains
290 * invalid encoded characters
291 */
292 }
293
294 for (i = 0; len && *from; i++, from += charlen, len -= charlen) {
295 charlen = codepage->char2uni(from, len, &wchar_to);
296 if (charlen < 1) {
297 cifs_dbg(VFS, "strtoUTF16: char2uni of 0x%x returned %d\n",
298 *from, charlen);
299 /* A question mark */
300 wchar_to = 0x003f;
301 charlen = 1;
302 }
303 put_unaligned_le16(wchar_to, &to[i]);
304 }
305
306success:
307 put_unaligned_le16(0, &to[i]);
308 return i;
309}
310
311/*
312 * cifs_utf16_bytes - how long will a string be after conversion?
313 * @utf16 - pointer to input string
314 * @maxbytes - don't go past this many bytes of input string
315 * @codepage - destination codepage
316 *
317 * Walk a utf16le string and return the number of bytes that the string will
318 * be after being converted to the given charset, not including any null
319 * termination required. Don't walk past maxbytes in the source buffer.
320 */
321int
322cifs_utf16_bytes(const __le16 *from, int maxbytes,
323 const struct nls_table *codepage)
324{
325 int i;
326 int charlen, outlen = 0;
327 int maxwords = maxbytes / 2;
328 char tmp[NLS_MAX_CHARSET_SIZE];
329 __u16 ftmp[3];
330
331 for (i = 0; i < maxwords; i++) {
332 ftmp[0] = get_unaligned_le16(&from[i]);
333 if (ftmp[0] == 0)
334 break;
335 if (i + 1 < maxwords)
336 ftmp[1] = get_unaligned_le16(&from[i + 1]);
337 else
338 ftmp[1] = 0;
339 if (i + 2 < maxwords)
340 ftmp[2] = get_unaligned_le16(&from[i + 2]);
341 else
342 ftmp[2] = 0;
343
344 charlen = cifs_mapchar(tmp, ftmp, codepage, NO_MAP_UNI_RSVD);
345 outlen += charlen;
346 }
347
348 return outlen;
349}
350
351/*
352 * cifs_strndup_from_utf16 - copy a string from wire format to the local
353 * codepage
354 * @src - source string
355 * @maxlen - don't walk past this many bytes in the source string
356 * @is_unicode - is this a unicode string?
357 * @codepage - destination codepage
358 *
359 * Take a string given by the server, convert it to the local codepage and
360 * put it in a new buffer. Returns a pointer to the new string or NULL on
361 * error.
362 */
363char *
364cifs_strndup_from_utf16(const char *src, const int maxlen,
365 const bool is_unicode, const struct nls_table *codepage)
366{
367 int len;
368 char *dst;
369
370 if (is_unicode) {
371 len = cifs_utf16_bytes((__le16 *) src, maxlen, codepage);
372 len += nls_nullsize(codepage);
373 dst = kmalloc(len, GFP_KERNEL);
374 if (!dst)
375 return NULL;
376 cifs_from_utf16(dst, (__le16 *) src, len, maxlen, codepage,
377 NO_MAP_UNI_RSVD);
378 } else {
379 len = strnlen(src, maxlen);
380 len++;
381 dst = kmalloc(len, GFP_KERNEL);
382 if (!dst)
383 return NULL;
384 strlcpy(dst, src, len);
385 }
386
387 return dst;
388}
389
390static __le16 convert_to_sfu_char(char src_char)
391{
392 __le16 dest_char;
393
394 switch (src_char) {
395 case ':':
396 dest_char = cpu_to_le16(UNI_COLON);
397 break;
398 case '*':
399 dest_char = cpu_to_le16(UNI_ASTERISK);
400 break;
401 case '?':
402 dest_char = cpu_to_le16(UNI_QUESTION);
403 break;
404 case '<':
405 dest_char = cpu_to_le16(UNI_LESSTHAN);
406 break;
407 case '>':
408 dest_char = cpu_to_le16(UNI_GRTRTHAN);
409 break;
410 case '|':
411 dest_char = cpu_to_le16(UNI_PIPE);
412 break;
413 default:
414 dest_char = 0;
415 }
416
417 return dest_char;
418}
419
420static __le16 convert_to_sfm_char(char src_char, bool end_of_string)
421{
422 __le16 dest_char;
423
424 if (src_char >= 0x01 && src_char <= 0x1F) {
425 dest_char = cpu_to_le16(src_char + 0xF000);
426 return dest_char;
427 }
428 switch (src_char) {
429 case ':':
430 dest_char = cpu_to_le16(SFM_COLON);
431 break;
432 case '"':
433 dest_char = cpu_to_le16(SFM_DOUBLEQUOTE);
434 break;
435 case '*':
436 dest_char = cpu_to_le16(SFM_ASTERISK);
437 break;
438 case '?':
439 dest_char = cpu_to_le16(SFM_QUESTION);
440 break;
441 case '<':
442 dest_char = cpu_to_le16(SFM_LESSTHAN);
443 break;
444 case '>':
445 dest_char = cpu_to_le16(SFM_GRTRTHAN);
446 break;
447 case '|':
448 dest_char = cpu_to_le16(SFM_PIPE);
449 break;
450 case '.':
451 if (end_of_string)
452 dest_char = cpu_to_le16(SFM_PERIOD);
453 else
454 dest_char = 0;
455 break;
456 case ' ':
457 if (end_of_string)
458 dest_char = cpu_to_le16(SFM_SPACE);
459 else
460 dest_char = 0;
461 break;
462 default:
463 dest_char = 0;
464 }
465
466 return dest_char;
467}
468
469/*
470 * Convert 16 bit Unicode pathname to wire format from string in current code
471 * page. Conversion may involve remapping up the six characters that are
472 * only legal in POSIX-like OS (if they are present in the string). Path
473 * names are little endian 16 bit Unicode on the wire
474 */
475int
476cifsConvertToUTF16(__le16 *target, const char *source, int srclen,
477 const struct nls_table *cp, int map_chars)
478{
479 int i, charlen;
480 int j = 0;
481 char src_char;
482 __le16 dst_char;
483 wchar_t tmp;
484 wchar_t *wchar_to; /* UTF-16 */
485 int ret;
486 unicode_t u;
487
488 if (map_chars == NO_MAP_UNI_RSVD)
489 return cifs_strtoUTF16(target, source, PATH_MAX, cp);
490
491 wchar_to = kzalloc(6, GFP_KERNEL);
492
493 for (i = 0; i < srclen; j++) {
494 src_char = source[i];
495 charlen = 1;
496
497 /* check if end of string */
498 if (src_char == 0)
499 goto ctoUTF16_out;
500
501 /* see if we must remap this char */
502 if (map_chars == SFU_MAP_UNI_RSVD)
503 dst_char = convert_to_sfu_char(src_char);
504 else if (map_chars == SFM_MAP_UNI_RSVD) {
505 bool end_of_string;
506
507 if (i == srclen - 1)
508 end_of_string = true;
509 else
510 end_of_string = false;
511
512 dst_char = convert_to_sfm_char(src_char, end_of_string);
513 } else
514 dst_char = 0;
515 /*
516 * FIXME: We can not handle remapping backslash (UNI_SLASH)
517 * until all the calls to build_path_from_dentry are modified,
518 * as they use backslash as separator.
519 */
520 if (dst_char == 0) {
521 charlen = cp->char2uni(source + i, srclen - i, &tmp);
522 dst_char = cpu_to_le16(tmp);
523
524 /*
525 * if no match, use question mark, which at least in
526 * some cases serves as wild card
527 */
528 if (charlen > 0)
529 goto ctoUTF16;
530
531 /* convert SURROGATE_PAIR */
532 if (strcmp(cp->charset, "utf8") || !wchar_to)
533 goto unknown;
534 if (*(source + i) & 0x80) {
535 charlen = utf8_to_utf32(source + i, 6, &u);
536 if (charlen < 0)
537 goto unknown;
538 } else
539 goto unknown;
540 ret = utf8s_to_utf16s(source + i, charlen,
541 UTF16_LITTLE_ENDIAN,
542 wchar_to, 6);
543 if (ret < 0)
544 goto unknown;
545
546 i += charlen;
547 dst_char = cpu_to_le16(*wchar_to);
548 if (charlen <= 3)
549 /* 1-3bytes UTF-8 to 2bytes UTF-16 */
550 put_unaligned(dst_char, &target[j]);
551 else if (charlen == 4) {
552 /* 4bytes UTF-8(surrogate pair) to 4bytes UTF-16
553 * 7-8bytes UTF-8(IVS) divided to 2 UTF-16
554 * (charlen=3+4 or 4+4) */
555 put_unaligned(dst_char, &target[j]);
556 dst_char = cpu_to_le16(*(wchar_to + 1));
557 j++;
558 put_unaligned(dst_char, &target[j]);
559 } else if (charlen >= 5) {
560 /* 5-6bytes UTF-8 to 6bytes UTF-16 */
561 put_unaligned(dst_char, &target[j]);
562 dst_char = cpu_to_le16(*(wchar_to + 1));
563 j++;
564 put_unaligned(dst_char, &target[j]);
565 dst_char = cpu_to_le16(*(wchar_to + 2));
566 j++;
567 put_unaligned(dst_char, &target[j]);
568 }
569 continue;
570
571unknown:
572 dst_char = cpu_to_le16(0x003f);
573 charlen = 1;
574 }
575
576ctoUTF16:
577 /*
578 * character may take more than one byte in the source string,
579 * but will take exactly two bytes in the target string
580 */
581 i += charlen;
582 put_unaligned(dst_char, &target[j]);
583 }
584
585ctoUTF16_out:
586 put_unaligned(0, &target[j]); /* Null terminate target unicode string */
587 kfree(wchar_to);
588 return j;
589}
590
591/*
592 * cifs_local_to_utf16_bytes - how long will a string be after conversion?
593 * @from - pointer to input string
594 * @maxbytes - don't go past this many bytes of input string
595 * @codepage - source codepage
596 *
597 * Walk a string and return the number of bytes that the string will
598 * be after being converted to the given charset, not including any null
599 * termination required. Don't walk past maxbytes in the source buffer.
600 */
601
602static int
603cifs_local_to_utf16_bytes(const char *from, int len,
604 const struct nls_table *codepage)
605{
606 int charlen;
607 int i;
608 wchar_t wchar_to;
609
610 for (i = 0; len && *from; i++, from += charlen, len -= charlen) {
611 charlen = codepage->char2uni(from, len, &wchar_to);
612 /* Failed conversion defaults to a question mark */
613 if (charlen < 1)
614 charlen = 1;
615 }
616 return 2 * i; /* UTF16 characters are two bytes */
617}
618
619/*
620 * cifs_strndup_to_utf16 - copy a string to wire format from the local codepage
621 * @src - source string
622 * @maxlen - don't walk past this many bytes in the source string
623 * @utf16_len - the length of the allocated string in bytes (including null)
624 * @cp - source codepage
625 * @remap - map special chars
626 *
627 * Take a string convert it from the local codepage to UTF16 and
628 * put it in a new buffer. Returns a pointer to the new string or NULL on
629 * error.
630 */
631__le16 *
632cifs_strndup_to_utf16(const char *src, const int maxlen, int *utf16_len,
633 const struct nls_table *cp, int remap)
634{
635 int len;
636 __le16 *dst;
637
638 len = cifs_local_to_utf16_bytes(src, maxlen, cp);
639 len += 2; /* NULL */
640 dst = kmalloc(len, GFP_KERNEL);
641 if (!dst) {
642 *utf16_len = 0;
643 return NULL;
644 }
645 cifsConvertToUTF16(dst, src, strlen(src), cp, remap);
646 *utf16_len = len;
647 return dst;
648}