2 * fs/cifs/cifs_unicode.c
4 * Copyright (c) International Business Machines Corp., 2000,2009
5 * Modified by Steve French (sfrench@us.ibm.com)
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.
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.
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
22 #include <linux/slab.h>
23 #include "cifs_unicode.h"
24 #include "cifs_uniupr.h"
27 #include "cifs_debug.h"
30 * cifs_utf16_bytes - how long will a string be after conversion?
31 * @utf16 - pointer to input string
32 * @maxbytes - don't go past this many bytes of input string
33 * @codepage - destination codepage
35 * Walk a utf16le 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.
40 cifs_utf16_bytes(const __le16
*from
, int maxbytes
,
41 const struct nls_table
*codepage
)
44 int charlen
, outlen
= 0;
45 int maxwords
= maxbytes
/ 2;
46 char tmp
[NLS_MAX_CHARSET_SIZE
];
49 for (i
= 0; i
< maxwords
; i
++) {
50 ftmp
= get_unaligned_le16(&from
[i
]);
54 charlen
= codepage
->uni2char(ftmp
, tmp
, NLS_MAX_CHARSET_SIZE
);
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?
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).
76 cifs_mapchar(char *target
, const __u16 src_char
, const struct nls_table
*cp
,
85 * BB: Cannot handle remapping UNI_SLASH until all the calls to
86 * build_path_from_dentry are modified, as they use slash as
116 len
= cp
->uni2char(src_char
, target
, NLS_MAX_CHARSET_SIZE
);
125 * cifs_from_utf16 - 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?
133 * Convert a little-endian utf16le 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
141 * Note that some windows versions actually send multiword UTF-16 characters
142 * instead of straight UTF16-2. 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.
147 cifs_from_utf16(char *to
, const __le16
*from
, int tolen
, int fromlen
,
148 const struct nls_table
*codepage
, bool mapchar
)
150 int i
, charlen
, safelen
;
152 int nullsize
= nls_nullsize(codepage
);
153 int fromwords
= fromlen
/ 2;
154 char tmp
[NLS_MAX_CHARSET_SIZE
];
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.
163 safelen
= tolen
- (NLS_MAX_CHARSET_SIZE
+ nullsize
);
165 for (i
= 0; i
< fromwords
; i
++) {
166 ftmp
= get_unaligned_le16(&from
[i
]);
171 * check to see if converting this character might make the
172 * conversion bleed into the null terminator
174 if (outlen
>= safelen
) {
175 charlen
= cifs_mapchar(tmp
, ftmp
, codepage
, mapchar
);
176 if ((outlen
+ charlen
) > (tolen
- nullsize
))
180 /* put converted char into 'to' buffer */
181 charlen
= cifs_mapchar(&to
[outlen
], ftmp
, codepage
, mapchar
);
185 /* properly null-terminate string */
186 for (i
= 0; i
< nullsize
; i
++)
193 * NAME: cifs_strtoUTF16()
195 * FUNCTION: Convert character string to unicode string
199 cifs_strtoUTF16(__le16
*to
, const char *from
, int len
,
200 const struct nls_table
*codepage
)
204 wchar_t wchar_to
; /* needed to quiet sparse */
206 /* special case for utf8 to handle no plane0 chars */
207 if (!strcmp(codepage
->charset
, "utf8")) {
209 * convert utf8 -> utf16, we assume we have enough space
210 * as caller should have assumed conversion does not overflow
211 * in destination len is length in wchar_t units (16bits)
213 i
= utf8s_to_utf16s(from
, len
, UTF16_LITTLE_ENDIAN
,
214 (wchar_t *) to
, len
);
216 /* if success terminate and exit */
220 * if fails fall back to UCS encoding as this
221 * function should not return negative values
222 * currently can fail only if source contains
223 * invalid encoded characters
227 for (i
= 0; len
&& *from
; i
++, from
+= charlen
, len
-= charlen
) {
228 charlen
= codepage
->char2uni(from
, len
, &wchar_to
);
230 cifs_dbg(VFS
, "strtoUTF16: char2uni of 0x%x returned %d\n",
232 /* A question mark */
236 put_unaligned_le16(wchar_to
, &to
[i
]);
240 put_unaligned_le16(0, &to
[i
]);
245 * cifs_strndup_from_utf16 - copy a string from wire format to the local
247 * @src - source string
248 * @maxlen - don't walk past this many bytes in the source string
249 * @is_unicode - is this a unicode string?
250 * @codepage - destination codepage
252 * Take a string given by the server, convert it to the local codepage and
253 * put it in a new buffer. Returns a pointer to the new string or NULL on
257 cifs_strndup_from_utf16(const char *src
, const int maxlen
,
258 const bool is_unicode
, const struct nls_table
*codepage
)
264 len
= cifs_utf16_bytes((__le16
*) src
, maxlen
, codepage
);
265 len
+= nls_nullsize(codepage
);
266 dst
= kmalloc(len
, GFP_KERNEL
);
269 cifs_from_utf16(dst
, (__le16
*) src
, len
, maxlen
, codepage
,
272 len
= strnlen(src
, maxlen
);
274 dst
= kmalloc(len
, GFP_KERNEL
);
277 strlcpy(dst
, src
, len
);
284 * Convert 16 bit Unicode pathname to wire format from string in current code
285 * page. Conversion may involve remapping up the six characters that are
286 * only legal in POSIX-like OS (if they are present in the string). Path
287 * names are little endian 16 bit Unicode on the wire
290 cifsConvertToUTF16(__le16
*target
, const char *source
, int srclen
,
291 const struct nls_table
*cp
, int mapChars
)
299 return cifs_strtoUTF16(target
, source
, PATH_MAX
, cp
);
301 for (i
= 0, j
= 0; i
< srclen
; j
++) {
302 src_char
= source
[i
];
306 put_unaligned(0, &target
[j
]);
309 dst_char
= cpu_to_le16(UNI_COLON
);
312 dst_char
= cpu_to_le16(UNI_ASTERISK
);
315 dst_char
= cpu_to_le16(UNI_QUESTION
);
318 dst_char
= cpu_to_le16(UNI_LESSTHAN
);
321 dst_char
= cpu_to_le16(UNI_GRTRTHAN
);
324 dst_char
= cpu_to_le16(UNI_PIPE
);
327 * FIXME: We can not handle remapping backslash (UNI_SLASH)
328 * until all the calls to build_path_from_dentry are modified,
329 * as they use backslash as separator.
332 charlen
= cp
->char2uni(source
+ i
, srclen
- i
, &tmp
);
333 dst_char
= cpu_to_le16(tmp
);
336 * if no match, use question mark, which at least in
337 * some cases serves as wild card
340 dst_char
= cpu_to_le16(0x003f);
345 * character may take more than one byte in the source string,
346 * but will take exactly two bytes in the target string
349 put_unaligned(dst_char
, &target
[j
]);
356 #ifdef CONFIG_CIFS_SMB2
358 * cifs_local_to_utf16_bytes - how long will a string be after conversion?
359 * @from - pointer to input string
360 * @maxbytes - don't go past this many bytes of input string
361 * @codepage - source codepage
363 * Walk a string and return the number of bytes that the string will
364 * be after being converted to the given charset, not including any null
365 * termination required. Don't walk past maxbytes in the source buffer.
369 cifs_local_to_utf16_bytes(const char *from
, int len
,
370 const struct nls_table
*codepage
)
376 for (i
= 0; len
&& *from
; i
++, from
+= charlen
, len
-= charlen
) {
377 charlen
= codepage
->char2uni(from
, len
, &wchar_to
);
378 /* Failed conversion defaults to a question mark */
382 return 2 * i
; /* UTF16 characters are two bytes */
386 * cifs_strndup_to_utf16 - copy a string to wire format from the local codepage
387 * @src - source string
388 * @maxlen - don't walk past this many bytes in the source string
389 * @utf16_len - the length of the allocated string in bytes (including null)
390 * @cp - source codepage
391 * @remap - map special chars
393 * Take a string convert it from the local codepage to UTF16 and
394 * put it in a new buffer. Returns a pointer to the new string or NULL on
398 cifs_strndup_to_utf16(const char *src
, const int maxlen
, int *utf16_len
,
399 const struct nls_table
*cp
, int remap
)
404 len
= cifs_local_to_utf16_bytes(src
, maxlen
, cp
);
406 dst
= kmalloc(len
, GFP_KERNEL
);
411 cifsConvertToUTF16(dst
, src
, strlen(src
), cp
, remap
);
415 #endif /* CONFIG_CIFS_SMB2 */
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