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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_unicode.h"
24#include "cifs_uniupr.h"
25#include "cifspdu.h"
26#include "cifsglob.h"
27#include "cifs_debug.h"
28
29/*
30 * cifs_ucs2_bytes - how long will a string be after conversion?
31 * @ucs - pointer to input string
32 * @maxbytes - don't go past this many bytes of input string
33 * @codepage - destination codepage
34 *
35 * Walk a ucs2le string and return the number of bytes that the string will
36 * be after being converted to the given charset, not including any null
37 * termination required. Don't walk past maxbytes in the source buffer.
38 */
39int
40cifs_ucs2_bytes(const __le16 *from, int maxbytes,
41 const struct nls_table *codepage)
42{
43 int i;
44 int charlen, outlen = 0;
45 int maxwords = maxbytes / 2;
46 char tmp[NLS_MAX_CHARSET_SIZE];
47 __u16 ftmp;
48
49 for (i = 0; i < maxwords; i++) {
50 ftmp = get_unaligned_le16(&from[i]);
51 if (ftmp == 0)
52 break;
53
54 charlen = codepage->uni2char(ftmp, tmp, NLS_MAX_CHARSET_SIZE);
55 if (charlen > 0)
56 outlen += charlen;
57 else
58 outlen++;
59 }
60
61 return outlen;
62}
63
64/*
65 * cifs_mapchar - convert a host-endian char to proper char in codepage
66 * @target - where converted character should be copied
67 * @src_char - 2 byte host-endian source character
68 * @cp - codepage to which character should be converted
69 * @mapchar - should character be mapped according to mapchars mount option?
70 *
71 * This function handles the conversion of a single character. It is the
72 * responsibility of the caller to ensure that the target buffer is large
73 * enough to hold the result of the conversion (at least NLS_MAX_CHARSET_SIZE).
74 */
75static int
76cifs_mapchar(char *target, const __u16 src_char, const struct nls_table *cp,
77 bool mapchar)
78{
79 int len = 1;
80
81 if (!mapchar)
82 goto cp_convert;
83
84 /*
85 * BB: Cannot handle remapping UNI_SLASH until all the calls to
86 * build_path_from_dentry are modified, as they use slash as
87 * separator.
88 */
89 switch (src_char) {
90 case UNI_COLON:
91 *target = ':';
92 break;
93 case UNI_ASTERISK:
94 *target = '*';
95 break;
96 case UNI_QUESTION:
97 *target = '?';
98 break;
99 case UNI_PIPE:
100 *target = '|';
101 break;
102 case UNI_GRTRTHAN:
103 *target = '>';
104 break;
105 case UNI_LESSTHAN:
106 *target = '<';
107 break;
108 default:
109 goto cp_convert;
110 }
111
112out:
113 return len;
114
115cp_convert:
116 len = cp->uni2char(src_char, target, NLS_MAX_CHARSET_SIZE);
117 if (len <= 0) {
118 *target = '?';
119 len = 1;
120 }
121 goto out;
122}
123
124/*
125 * cifs_from_ucs2 - convert utf16le string to local charset
126 * @to - destination buffer
127 * @from - source buffer
128 * @tolen - destination buffer size (in bytes)
129 * @fromlen - source buffer size (in bytes)
130 * @codepage - codepage to which characters should be converted
131 * @mapchar - should characters be remapped according to the mapchars option?
132 *
133 * Convert a little-endian ucs2le string (as sent by the server) to a string
134 * in the provided codepage. The tolen and fromlen parameters are to ensure
135 * that the code doesn't walk off of the end of the buffer (which is always
136 * a danger if the alignment of the source buffer is off). The destination
137 * string is always properly null terminated and fits in the destination
138 * buffer. Returns the length of the destination string in bytes (including
139 * null terminator).
140 *
141 * Note that some windows versions actually send multiword UTF-16 characters
142 * instead of straight UCS-2. The linux nls routines however aren't able to
143 * deal with those characters properly. In the event that we get some of
144 * those characters, they won't be translated properly.
145 */
146int
147cifs_from_ucs2(char *to, const __le16 *from, int tolen, int fromlen,
148 const struct nls_table *codepage, bool mapchar)
149{
150 int i, charlen, safelen;
151 int outlen = 0;
152 int nullsize = nls_nullsize(codepage);
153 int fromwords = fromlen / 2;
154 char tmp[NLS_MAX_CHARSET_SIZE];
155 __u16 ftmp;
156
157 /*
158 * because the chars can be of varying widths, we need to take care
159 * not to overflow the destination buffer when we get close to the
160 * end of it. Until we get to this offset, we don't need to check
161 * for overflow however.
162 */
163 safelen = tolen - (NLS_MAX_CHARSET_SIZE + nullsize);
164
165 for (i = 0; i < fromwords; i++) {
166 ftmp = get_unaligned_le16(&from[i]);
167 if (ftmp == 0)
168 break;
169
170 /*
171 * check to see if converting this character might make the
172 * conversion bleed into the null terminator
173 */
174 if (outlen >= safelen) {
175 charlen = cifs_mapchar(tmp, ftmp, codepage, mapchar);
176 if ((outlen + charlen) > (tolen - nullsize))
177 break;
178 }
179
180 /* put converted char into 'to' buffer */
181 charlen = cifs_mapchar(&to[outlen], ftmp, codepage, mapchar);
182 outlen += charlen;
183 }
184
185 /* properly null-terminate string */
186 for (i = 0; i < nullsize; i++)
187 to[outlen++] = 0;
188
189 return outlen;
190}
191
192/*
193 * NAME: cifs_strtoUCS()
194 *
195 * FUNCTION: Convert character string to unicode string
196 *
197 */
198int
199cifs_strtoUCS(__le16 *to, const char *from, int len,
200 const struct nls_table *codepage)
201{
202 int charlen;
203 int i;
204 wchar_t wchar_to; /* needed to quiet sparse */
205
206 for (i = 0; len && *from; i++, from += charlen, len -= charlen) {
207 charlen = codepage->char2uni(from, len, &wchar_to);
208 if (charlen < 1) {
209 cERROR(1, "strtoUCS: char2uni of 0x%x returned %d",
210 *from, charlen);
211 /* A question mark */
212 wchar_to = 0x003f;
213 charlen = 1;
214 }
215 put_unaligned_le16(wchar_to, &to[i]);
216 }
217
218 put_unaligned_le16(0, &to[i]);
219 return i;
220}
221
222/*
223 * cifs_strndup_from_ucs - copy a string from wire format to the local codepage
224 * @src - source string
225 * @maxlen - don't walk past this many bytes in the source string
226 * @is_unicode - is this a unicode string?
227 * @codepage - destination codepage
228 *
229 * Take a string given by the server, convert it to the local codepage and
230 * put it in a new buffer. Returns a pointer to the new string or NULL on
231 * error.
232 */
233char *
234cifs_strndup_from_ucs(const char *src, const int maxlen, const bool is_unicode,
235 const struct nls_table *codepage)
236{
237 int len;
238 char *dst;
239
240 if (is_unicode) {
241 len = cifs_ucs2_bytes((__le16 *) src, maxlen, codepage);
242 len += nls_nullsize(codepage);
243 dst = kmalloc(len, GFP_KERNEL);
244 if (!dst)
245 return NULL;
246 cifs_from_ucs2(dst, (__le16 *) src, len, maxlen, codepage,
247 false);
248 } else {
249 len = strnlen(src, maxlen);
250 len++;
251 dst = kmalloc(len, GFP_KERNEL);
252 if (!dst)
253 return NULL;
254 strlcpy(dst, src, len);
255 }
256
257 return dst;
258}
259
260/*
261 * Convert 16 bit Unicode pathname to wire format from string in current code
262 * page. Conversion may involve remapping up the six characters that are
263 * only legal in POSIX-like OS (if they are present in the string). Path
264 * names are little endian 16 bit Unicode on the wire
265 */
266int
267cifsConvertToUCS(__le16 *target, const char *source, int srclen,
268 const struct nls_table *cp, int mapChars)
269{
270 int i, j, charlen;
271 char src_char;
272 __le16 dst_char;
273 wchar_t tmp;
274
275 if (!mapChars)
276 return cifs_strtoUCS(target, source, PATH_MAX, cp);
277
278 for (i = 0, j = 0; i < srclen; j++) {
279 src_char = source[i];
280 charlen = 1;
281 switch (src_char) {
282 case 0:
283 put_unaligned(0, &target[j]);
284 goto ctoUCS_out;
285 case ':':
286 dst_char = cpu_to_le16(UNI_COLON);
287 break;
288 case '*':
289 dst_char = cpu_to_le16(UNI_ASTERISK);
290 break;
291 case '?':
292 dst_char = cpu_to_le16(UNI_QUESTION);
293 break;
294 case '<':
295 dst_char = cpu_to_le16(UNI_LESSTHAN);
296 break;
297 case '>':
298 dst_char = cpu_to_le16(UNI_GRTRTHAN);
299 break;
300 case '|':
301 dst_char = cpu_to_le16(UNI_PIPE);
302 break;
303 /*
304 * FIXME: We can not handle remapping backslash (UNI_SLASH)
305 * until all the calls to build_path_from_dentry are modified,
306 * as they use backslash as separator.
307 */
308 default:
309 charlen = cp->char2uni(source + i, srclen - i, &tmp);
310 dst_char = cpu_to_le16(tmp);
311
312 /*
313 * if no match, use question mark, which at least in
314 * some cases serves as wild card
315 */
316 if (charlen < 1) {
317 dst_char = cpu_to_le16(0x003f);
318 charlen = 1;
319 }
320 }
321 /*
322 * character may take more than one byte in the source string,
323 * but will take exactly two bytes in the target string
324 */
325 i += charlen;
326 put_unaligned(dst_char, &target[j]);
327 }
328
329ctoUCS_out:
330 return i;
331}
332
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * 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 */
8#include <linux/fs.h>
9#include <linux/slab.h>
10#include "cifs_fs_sb.h"
11#include "cifs_unicode.h"
12#include "cifs_uniupr.h"
13#include "cifspdu.h"
14#include "cifsglob.h"
15#include "cifs_debug.h"
16
17int cifs_remap(struct cifs_sb_info *cifs_sb)
18{
19 int map_type;
20
21 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SFM_CHR)
22 map_type = SFM_MAP_UNI_RSVD;
23 else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR)
24 map_type = SFU_MAP_UNI_RSVD;
25 else
26 map_type = NO_MAP_UNI_RSVD;
27
28 return map_type;
29}
30
31/* Convert character using the SFU - "Services for Unix" remapping range */
32static bool
33convert_sfu_char(const __u16 src_char, char *target)
34{
35 /*
36 * BB: Cannot handle remapping UNI_SLASH until all the calls to
37 * build_path_from_dentry are modified, as they use slash as
38 * separator.
39 */
40 switch (src_char) {
41 case UNI_COLON:
42 *target = ':';
43 break;
44 case UNI_ASTERISK:
45 *target = '*';
46 break;
47 case UNI_QUESTION:
48 *target = '?';
49 break;
50 case UNI_PIPE:
51 *target = '|';
52 break;
53 case UNI_GRTRTHAN:
54 *target = '>';
55 break;
56 case UNI_LESSTHAN:
57 *target = '<';
58 break;
59 default:
60 return false;
61 }
62 return true;
63}
64
65/* Convert character using the SFM - "Services for Mac" remapping range */
66static bool
67convert_sfm_char(const __u16 src_char, char *target)
68{
69 if (src_char >= 0xF001 && src_char <= 0xF01F) {
70 *target = src_char - 0xF000;
71 return true;
72 }
73 switch (src_char) {
74 case SFM_COLON:
75 *target = ':';
76 break;
77 case SFM_DOUBLEQUOTE:
78 *target = '"';
79 break;
80 case SFM_ASTERISK:
81 *target = '*';
82 break;
83 case SFM_QUESTION:
84 *target = '?';
85 break;
86 case SFM_PIPE:
87 *target = '|';
88 break;
89 case SFM_GRTRTHAN:
90 *target = '>';
91 break;
92 case SFM_LESSTHAN:
93 *target = '<';
94 break;
95 case SFM_SPACE:
96 *target = ' ';
97 break;
98 case SFM_PERIOD:
99 *target = '.';
100 break;
101 default:
102 return false;
103 }
104 return true;
105}
106
107
108/*
109 * cifs_mapchar - convert a host-endian char to proper char in codepage
110 * @target - where converted character should be copied
111 * @src_char - 2 byte host-endian source character
112 * @cp - codepage to which character should be converted
113 * @map_type - How should the 7 NTFS/SMB reserved characters be mapped to UCS2?
114 *
115 * This function handles the conversion of a single character. It is the
116 * responsibility of the caller to ensure that the target buffer is large
117 * enough to hold the result of the conversion (at least NLS_MAX_CHARSET_SIZE).
118 */
119static int
120cifs_mapchar(char *target, const __u16 *from, const struct nls_table *cp,
121 int maptype)
122{
123 int len = 1;
124 __u16 src_char;
125
126 src_char = *from;
127
128 if ((maptype == SFM_MAP_UNI_RSVD) && convert_sfm_char(src_char, target))
129 return len;
130 else if ((maptype == SFU_MAP_UNI_RSVD) &&
131 convert_sfu_char(src_char, target))
132 return len;
133
134 /* if character not one of seven in special remap set */
135 len = cp->uni2char(src_char, target, NLS_MAX_CHARSET_SIZE);
136 if (len <= 0)
137 goto surrogate_pair;
138
139 return len;
140
141surrogate_pair:
142 /* convert SURROGATE_PAIR and IVS */
143 if (strcmp(cp->charset, "utf8"))
144 goto unknown;
145 len = utf16s_to_utf8s(from, 3, UTF16_LITTLE_ENDIAN, target, 6);
146 if (len <= 0)
147 goto unknown;
148 return len;
149
150unknown:
151 *target = '?';
152 len = 1;
153 return len;
154}
155
156/*
157 * cifs_from_utf16 - convert utf16le string to local charset
158 * @to - destination buffer
159 * @from - source buffer
160 * @tolen - destination buffer size (in bytes)
161 * @fromlen - source buffer size (in bytes)
162 * @codepage - codepage to which characters should be converted
163 * @mapchar - should characters be remapped according to the mapchars option?
164 *
165 * Convert a little-endian utf16le string (as sent by the server) to a string
166 * in the provided codepage. The tolen and fromlen parameters are to ensure
167 * that the code doesn't walk off of the end of the buffer (which is always
168 * a danger if the alignment of the source buffer is off). The destination
169 * string is always properly null terminated and fits in the destination
170 * buffer. Returns the length of the destination string in bytes (including
171 * null terminator).
172 *
173 * Note that some windows versions actually send multiword UTF-16 characters
174 * instead of straight UTF16-2. The linux nls routines however aren't able to
175 * deal with those characters properly. In the event that we get some of
176 * those characters, they won't be translated properly.
177 */
178int
179cifs_from_utf16(char *to, const __le16 *from, int tolen, int fromlen,
180 const struct nls_table *codepage, int map_type)
181{
182 int i, charlen, safelen;
183 int outlen = 0;
184 int nullsize = nls_nullsize(codepage);
185 int fromwords = fromlen / 2;
186 char tmp[NLS_MAX_CHARSET_SIZE];
187 __u16 ftmp[3]; /* ftmp[3] = 3array x 2bytes = 6bytes UTF-16 */
188
189 /*
190 * because the chars can be of varying widths, we need to take care
191 * not to overflow the destination buffer when we get close to the
192 * end of it. Until we get to this offset, we don't need to check
193 * for overflow however.
194 */
195 safelen = tolen - (NLS_MAX_CHARSET_SIZE + nullsize);
196
197 for (i = 0; i < fromwords; i++) {
198 ftmp[0] = get_unaligned_le16(&from[i]);
199 if (ftmp[0] == 0)
200 break;
201 if (i + 1 < fromwords)
202 ftmp[1] = get_unaligned_le16(&from[i + 1]);
203 else
204 ftmp[1] = 0;
205 if (i + 2 < fromwords)
206 ftmp[2] = get_unaligned_le16(&from[i + 2]);
207 else
208 ftmp[2] = 0;
209
210 /*
211 * check to see if converting this character might make the
212 * conversion bleed into the null terminator
213 */
214 if (outlen >= safelen) {
215 charlen = cifs_mapchar(tmp, ftmp, codepage, map_type);
216 if ((outlen + charlen) > (tolen - nullsize))
217 break;
218 }
219
220 /* put converted char into 'to' buffer */
221 charlen = cifs_mapchar(&to[outlen], ftmp, codepage, map_type);
222 outlen += charlen;
223
224 /* charlen (=bytes of UTF-8 for 1 character)
225 * 4bytes UTF-8(surrogate pair) is charlen=4
226 * (4bytes UTF-16 code)
227 * 7-8bytes UTF-8(IVS) is charlen=3+4 or 4+4
228 * (2 UTF-8 pairs divided to 2 UTF-16 pairs) */
229 if (charlen == 4)
230 i++;
231 else if (charlen >= 5)
232 /* 5-6bytes UTF-8 */
233 i += 2;
234 }
235
236 /* properly null-terminate string */
237 for (i = 0; i < nullsize; i++)
238 to[outlen++] = 0;
239
240 return outlen;
241}
242
243/*
244 * NAME: cifs_strtoUTF16()
245 *
246 * FUNCTION: Convert character string to unicode string
247 *
248 */
249int
250cifs_strtoUTF16(__le16 *to, const char *from, int len,
251 const struct nls_table *codepage)
252{
253 int charlen;
254 int i;
255 wchar_t wchar_to; /* needed to quiet sparse */
256
257 /* special case for utf8 to handle no plane0 chars */
258 if (!strcmp(codepage->charset, "utf8")) {
259 /*
260 * convert utf8 -> utf16, we assume we have enough space
261 * as caller should have assumed conversion does not overflow
262 * in destination len is length in wchar_t units (16bits)
263 */
264 i = utf8s_to_utf16s(from, len, UTF16_LITTLE_ENDIAN,
265 (wchar_t *) to, len);
266
267 /* if success terminate and exit */
268 if (i >= 0)
269 goto success;
270 /*
271 * if fails fall back to UCS encoding as this
272 * function should not return negative values
273 * currently can fail only if source contains
274 * invalid encoded characters
275 */
276 }
277
278 for (i = 0; len && *from; i++, from += charlen, len -= charlen) {
279 charlen = codepage->char2uni(from, len, &wchar_to);
280 if (charlen < 1) {
281 cifs_dbg(VFS, "strtoUTF16: char2uni of 0x%x returned %d\n",
282 *from, charlen);
283 /* A question mark */
284 wchar_to = 0x003f;
285 charlen = 1;
286 }
287 put_unaligned_le16(wchar_to, &to[i]);
288 }
289
290success:
291 put_unaligned_le16(0, &to[i]);
292 return i;
293}
294
295/*
296 * cifs_utf16_bytes - how long will a string be after conversion?
297 * @utf16 - pointer to input string
298 * @maxbytes - don't go past this many bytes of input string
299 * @codepage - destination codepage
300 *
301 * Walk a utf16le string and return the number of bytes that the string will
302 * be after being converted to the given charset, not including any null
303 * termination required. Don't walk past maxbytes in the source buffer.
304 */
305int
306cifs_utf16_bytes(const __le16 *from, int maxbytes,
307 const struct nls_table *codepage)
308{
309 int i;
310 int charlen, outlen = 0;
311 int maxwords = maxbytes / 2;
312 char tmp[NLS_MAX_CHARSET_SIZE];
313 __u16 ftmp[3];
314
315 for (i = 0; i < maxwords; i++) {
316 ftmp[0] = get_unaligned_le16(&from[i]);
317 if (ftmp[0] == 0)
318 break;
319 if (i + 1 < maxwords)
320 ftmp[1] = get_unaligned_le16(&from[i + 1]);
321 else
322 ftmp[1] = 0;
323 if (i + 2 < maxwords)
324 ftmp[2] = get_unaligned_le16(&from[i + 2]);
325 else
326 ftmp[2] = 0;
327
328 charlen = cifs_mapchar(tmp, ftmp, codepage, NO_MAP_UNI_RSVD);
329 outlen += charlen;
330 }
331
332 return outlen;
333}
334
335/*
336 * cifs_strndup_from_utf16 - copy a string from wire format to the local
337 * codepage
338 * @src - source string
339 * @maxlen - don't walk past this many bytes in the source string
340 * @is_unicode - is this a unicode string?
341 * @codepage - destination codepage
342 *
343 * Take a string given by the server, convert it to the local codepage and
344 * put it in a new buffer. Returns a pointer to the new string or NULL on
345 * error.
346 */
347char *
348cifs_strndup_from_utf16(const char *src, const int maxlen,
349 const bool is_unicode, const struct nls_table *codepage)
350{
351 int len;
352 char *dst;
353
354 if (is_unicode) {
355 len = cifs_utf16_bytes((__le16 *) src, maxlen, codepage);
356 len += nls_nullsize(codepage);
357 dst = kmalloc(len, GFP_KERNEL);
358 if (!dst)
359 return NULL;
360 cifs_from_utf16(dst, (__le16 *) src, len, maxlen, codepage,
361 NO_MAP_UNI_RSVD);
362 } else {
363 dst = kstrndup(src, maxlen, GFP_KERNEL);
364 }
365
366 return dst;
367}
368
369static __le16 convert_to_sfu_char(char src_char)
370{
371 __le16 dest_char;
372
373 switch (src_char) {
374 case ':':
375 dest_char = cpu_to_le16(UNI_COLON);
376 break;
377 case '*':
378 dest_char = cpu_to_le16(UNI_ASTERISK);
379 break;
380 case '?':
381 dest_char = cpu_to_le16(UNI_QUESTION);
382 break;
383 case '<':
384 dest_char = cpu_to_le16(UNI_LESSTHAN);
385 break;
386 case '>':
387 dest_char = cpu_to_le16(UNI_GRTRTHAN);
388 break;
389 case '|':
390 dest_char = cpu_to_le16(UNI_PIPE);
391 break;
392 default:
393 dest_char = 0;
394 }
395
396 return dest_char;
397}
398
399static __le16 convert_to_sfm_char(char src_char, bool end_of_string)
400{
401 __le16 dest_char;
402
403 if (src_char >= 0x01 && src_char <= 0x1F) {
404 dest_char = cpu_to_le16(src_char + 0xF000);
405 return dest_char;
406 }
407 switch (src_char) {
408 case ':':
409 dest_char = cpu_to_le16(SFM_COLON);
410 break;
411 case '"':
412 dest_char = cpu_to_le16(SFM_DOUBLEQUOTE);
413 break;
414 case '*':
415 dest_char = cpu_to_le16(SFM_ASTERISK);
416 break;
417 case '?':
418 dest_char = cpu_to_le16(SFM_QUESTION);
419 break;
420 case '<':
421 dest_char = cpu_to_le16(SFM_LESSTHAN);
422 break;
423 case '>':
424 dest_char = cpu_to_le16(SFM_GRTRTHAN);
425 break;
426 case '|':
427 dest_char = cpu_to_le16(SFM_PIPE);
428 break;
429 case '.':
430 if (end_of_string)
431 dest_char = cpu_to_le16(SFM_PERIOD);
432 else
433 dest_char = 0;
434 break;
435 case ' ':
436 if (end_of_string)
437 dest_char = cpu_to_le16(SFM_SPACE);
438 else
439 dest_char = 0;
440 break;
441 default:
442 dest_char = 0;
443 }
444
445 return dest_char;
446}
447
448/*
449 * Convert 16 bit Unicode pathname to wire format from string in current code
450 * page. Conversion may involve remapping up the six characters that are
451 * only legal in POSIX-like OS (if they are present in the string). Path
452 * names are little endian 16 bit Unicode on the wire
453 */
454int
455cifsConvertToUTF16(__le16 *target, const char *source, int srclen,
456 const struct nls_table *cp, int map_chars)
457{
458 int i, charlen;
459 int j = 0;
460 char src_char;
461 __le16 dst_char;
462 wchar_t tmp;
463 wchar_t *wchar_to; /* UTF-16 */
464 int ret;
465 unicode_t u;
466
467 if (map_chars == NO_MAP_UNI_RSVD)
468 return cifs_strtoUTF16(target, source, PATH_MAX, cp);
469
470 wchar_to = kzalloc(6, GFP_KERNEL);
471
472 for (i = 0; i < srclen; j++) {
473 src_char = source[i];
474 charlen = 1;
475
476 /* check if end of string */
477 if (src_char == 0)
478 goto ctoUTF16_out;
479
480 /* see if we must remap this char */
481 if (map_chars == SFU_MAP_UNI_RSVD)
482 dst_char = convert_to_sfu_char(src_char);
483 else if (map_chars == SFM_MAP_UNI_RSVD) {
484 bool end_of_string;
485
486 /**
487 * Remap spaces and periods found at the end of every
488 * component of the path. The special cases of '.' and
489 * '..' do not need to be dealt with explicitly because
490 * they are addressed in namei.c:link_path_walk().
491 **/
492 if ((i == srclen - 1) || (source[i+1] == '\\'))
493 end_of_string = true;
494 else
495 end_of_string = false;
496
497 dst_char = convert_to_sfm_char(src_char, end_of_string);
498 } else
499 dst_char = 0;
500 /*
501 * FIXME: We can not handle remapping backslash (UNI_SLASH)
502 * until all the calls to build_path_from_dentry are modified,
503 * as they use backslash as separator.
504 */
505 if (dst_char == 0) {
506 charlen = cp->char2uni(source + i, srclen - i, &tmp);
507 dst_char = cpu_to_le16(tmp);
508
509 /*
510 * if no match, use question mark, which at least in
511 * some cases serves as wild card
512 */
513 if (charlen > 0)
514 goto ctoUTF16;
515
516 /* convert SURROGATE_PAIR */
517 if (strcmp(cp->charset, "utf8") || !wchar_to)
518 goto unknown;
519 if (*(source + i) & 0x80) {
520 charlen = utf8_to_utf32(source + i, 6, &u);
521 if (charlen < 0)
522 goto unknown;
523 } else
524 goto unknown;
525 ret = utf8s_to_utf16s(source + i, charlen,
526 UTF16_LITTLE_ENDIAN,
527 wchar_to, 6);
528 if (ret < 0)
529 goto unknown;
530
531 i += charlen;
532 dst_char = cpu_to_le16(*wchar_to);
533 if (charlen <= 3)
534 /* 1-3bytes UTF-8 to 2bytes UTF-16 */
535 put_unaligned(dst_char, &target[j]);
536 else if (charlen == 4) {
537 /* 4bytes UTF-8(surrogate pair) to 4bytes UTF-16
538 * 7-8bytes UTF-8(IVS) divided to 2 UTF-16
539 * (charlen=3+4 or 4+4) */
540 put_unaligned(dst_char, &target[j]);
541 dst_char = cpu_to_le16(*(wchar_to + 1));
542 j++;
543 put_unaligned(dst_char, &target[j]);
544 } else if (charlen >= 5) {
545 /* 5-6bytes UTF-8 to 6bytes UTF-16 */
546 put_unaligned(dst_char, &target[j]);
547 dst_char = cpu_to_le16(*(wchar_to + 1));
548 j++;
549 put_unaligned(dst_char, &target[j]);
550 dst_char = cpu_to_le16(*(wchar_to + 2));
551 j++;
552 put_unaligned(dst_char, &target[j]);
553 }
554 continue;
555
556unknown:
557 dst_char = cpu_to_le16(0x003f);
558 charlen = 1;
559 }
560
561ctoUTF16:
562 /*
563 * character may take more than one byte in the source string,
564 * but will take exactly two bytes in the target string
565 */
566 i += charlen;
567 put_unaligned(dst_char, &target[j]);
568 }
569
570ctoUTF16_out:
571 put_unaligned(0, &target[j]); /* Null terminate target unicode string */
572 kfree(wchar_to);
573 return j;
574}
575
576/*
577 * cifs_local_to_utf16_bytes - how long will a string be after conversion?
578 * @from - pointer to input string
579 * @maxbytes - don't go past this many bytes of input string
580 * @codepage - source codepage
581 *
582 * Walk a string and return the number of bytes that the string will
583 * be after being converted to the given charset, not including any null
584 * termination required. Don't walk past maxbytes in the source buffer.
585 */
586
587static int
588cifs_local_to_utf16_bytes(const char *from, int len,
589 const struct nls_table *codepage)
590{
591 int charlen;
592 int i;
593 wchar_t wchar_to;
594
595 for (i = 0; len && *from; i++, from += charlen, len -= charlen) {
596 charlen = codepage->char2uni(from, len, &wchar_to);
597 /* Failed conversion defaults to a question mark */
598 if (charlen < 1)
599 charlen = 1;
600 }
601 return 2 * i; /* UTF16 characters are two bytes */
602}
603
604/*
605 * cifs_strndup_to_utf16 - copy a string to wire format from the local codepage
606 * @src - source string
607 * @maxlen - don't walk past this many bytes in the source string
608 * @utf16_len - the length of the allocated string in bytes (including null)
609 * @cp - source codepage
610 * @remap - map special chars
611 *
612 * Take a string convert it from the local codepage to UTF16 and
613 * put it in a new buffer. Returns a pointer to the new string or NULL on
614 * error.
615 */
616__le16 *
617cifs_strndup_to_utf16(const char *src, const int maxlen, int *utf16_len,
618 const struct nls_table *cp, int remap)
619{
620 int len;
621 __le16 *dst;
622
623 len = cifs_local_to_utf16_bytes(src, maxlen, cp);
624 len += 2; /* NULL */
625 dst = kmalloc(len, GFP_KERNEL);
626 if (!dst) {
627 *utf16_len = 0;
628 return NULL;
629 }
630 cifsConvertToUTF16(dst, src, strlen(src), cp, remap);
631 *utf16_len = len;
632 return dst;
633}