diff options
Diffstat (limited to 'fs/cifs/cifs_unicode.c')
| -rw-r--r-- | fs/cifs/cifs_unicode.c | 333 |
1 files changed, 333 insertions, 0 deletions
diff --git a/fs/cifs/cifs_unicode.c b/fs/cifs/cifs_unicode.c new file mode 100644 index 00000000..fbb9da95 --- /dev/null +++ b/fs/cifs/cifs_unicode.c @@ -0,0 +1,333 @@ +/* + * fs/cifs/cifs_unicode.c + * + * Copyright (c) International Business Machines Corp., 2000,2009 + * Modified by Steve French (sfrench@us.ibm.com) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See + * the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ +#include <linux/fs.h> +#include <linux/slab.h> +#include "cifs_unicode.h" +#include "cifs_uniupr.h" +#include "cifspdu.h" +#include "cifsglob.h" +#include "cifs_debug.h" + +/* + * cifs_utf16_bytes - how long will a string be after conversion? + * @utf16 - pointer to input string + * @maxbytes - don't go past this many bytes of input string + * @codepage - destination codepage + * + * Walk a utf16le string and return the number of bytes that the string will + * be after being converted to the given charset, not including any null + * termination required. Don't walk past maxbytes in the source buffer. + */ +int +cifs_utf16_bytes(const __le16 *from, int maxbytes, + const struct nls_table *codepage) +{ + int i; + int charlen, outlen = 0; + int maxwords = maxbytes / 2; + char tmp[NLS_MAX_CHARSET_SIZE]; + __u16 ftmp; + + for (i = 0; i < maxwords; i++) { + ftmp = get_unaligned_le16(&from[i]); + if (ftmp == 0) + break; + + charlen = codepage->uni2char(ftmp, tmp, NLS_MAX_CHARSET_SIZE); + if (charlen > 0) + outlen += charlen; + else + outlen++; + } + + return outlen; +} + +/* + * cifs_mapchar - convert a host-endian char to proper char in codepage + * @target - where converted character should be copied + * @src_char - 2 byte host-endian source character + * @cp - codepage to which character should be converted + * @mapchar - should character be mapped according to mapchars mount option? + * + * This function handles the conversion of a single character. It is the + * responsibility of the caller to ensure that the target buffer is large + * enough to hold the result of the conversion (at least NLS_MAX_CHARSET_SIZE). + */ +static int +cifs_mapchar(char *target, const __u16 src_char, const struct nls_table *cp, + bool mapchar) +{ + int len = 1; + + if (!mapchar) + goto cp_convert; + + /* + * BB: Cannot handle remapping UNI_SLASH until all the calls to + * build_path_from_dentry are modified, as they use slash as + * separator. + */ + switch (src_char) { + case UNI_COLON: + *target = ':'; + break; + case UNI_ASTERISK: + *target = '*'; + break; + case UNI_QUESTION: + *target = '?'; + break; + case UNI_PIPE: + *target = '|'; + break; + case UNI_GRTRTHAN: + *target = '>'; + break; + case UNI_LESSTHAN: + *target = '<'; + break; + default: + goto cp_convert; + } + +out: + return len; + +cp_convert: + len = cp->uni2char(src_char, target, NLS_MAX_CHARSET_SIZE); + if (len <= 0) { + *target = '?'; + len = 1; + } + goto out; +} + +/* + * cifs_from_utf16 - convert utf16le string to local charset + * @to - destination buffer + * @from - source buffer + * @tolen - destination buffer size (in bytes) + * @fromlen - source buffer size (in bytes) + * @codepage - codepage to which characters should be converted + * @mapchar - should characters be remapped according to the mapchars option? + * + * Convert a little-endian utf16le string (as sent by the server) to a string + * in the provided codepage. The tolen and fromlen parameters are to ensure + * that the code doesn't walk off of the end of the buffer (which is always + * a danger if the alignment of the source buffer is off). The destination + * string is always properly null terminated and fits in the destination + * buffer. Returns the length of the destination string in bytes (including + * null terminator). + * + * Note that some windows versions actually send multiword UTF-16 characters + * instead of straight UTF16-2. The linux nls routines however aren't able to + * deal with those characters properly. In the event that we get some of + * those characters, they won't be translated properly. + */ +int +cifs_from_utf16(char *to, const __le16 *from, int tolen, int fromlen, + const struct nls_table *codepage, bool mapchar) +{ + int i, charlen, safelen; + int outlen = 0; + int nullsize = nls_nullsize(codepage); + int fromwords = fromlen / 2; + char tmp[NLS_MAX_CHARSET_SIZE]; + __u16 ftmp; + + /* + * because the chars can be of varying widths, we need to take care + * not to overflow the destination buffer when we get close to the + * end of it. Until we get to this offset, we don't need to check + * for overflow however. + */ + safelen = tolen - (NLS_MAX_CHARSET_SIZE + nullsize); + + for (i = 0; i < fromwords; i++) { + ftmp = get_unaligned_le16(&from[i]); + if (ftmp == 0) + break; + + /* + * check to see if converting this character might make the + * conversion bleed into the null terminator + */ + if (outlen >= safelen) { + charlen = cifs_mapchar(tmp, ftmp, codepage, mapchar); + if ((outlen + charlen) > (tolen - nullsize)) + break; + } + + /* put converted char into 'to' buffer */ + charlen = cifs_mapchar(&to[outlen], ftmp, codepage, mapchar); + outlen += charlen; + } + + /* properly null-terminate string */ + for (i = 0; i < nullsize; i++) + to[outlen++] = 0; + + return outlen; +} + +/* + * NAME: cifs_strtoUTF16() + * + * FUNCTION: Convert character string to unicode string + * + */ +int +cifs_strtoUTF16(__le16 *to, const char *from, int len, + const struct nls_table *codepage) +{ + int charlen; + int i; + wchar_t wchar_to; /* needed to quiet sparse */ + + for (i = 0; len && *from; i++, from += charlen, len -= charlen) { + charlen = codepage->char2uni(from, len, &wchar_to); + if (charlen < 1) { + cERROR(1, "strtoUTF16: char2uni of 0x%x returned %d", + *from, charlen); + /* A question mark */ + wchar_to = 0x003f; + charlen = 1; + } + put_unaligned_le16(wchar_to, &to[i]); + } + + put_unaligned_le16(0, &to[i]); + return i; +} + +/* + * cifs_strndup_from_utf16 - copy a string from wire format to the local + * codepage + * @src - source string + * @maxlen - don't walk past this many bytes in the source string + * @is_unicode - is this a unicode string? + * @codepage - destination codepage + * + * Take a string given by the server, convert it to the local codepage and + * put it in a new buffer. Returns a pointer to the new string or NULL on + * error. + */ +char * +cifs_strndup_from_utf16(const char *src, const int maxlen, + const bool is_unicode, const struct nls_table *codepage) +{ + int len; + char *dst; + + if (is_unicode) { + len = cifs_utf16_bytes((__le16 *) src, maxlen, codepage); + len += nls_nullsize(codepage); + dst = kmalloc(len, GFP_KERNEL); + if (!dst) + return NULL; + cifs_from_utf16(dst, (__le16 *) src, len, maxlen, codepage, + false); + } else { + len = strnlen(src, maxlen); + len++; + dst = kmalloc(len, GFP_KERNEL); + if (!dst) + return NULL; + strlcpy(dst, src, len); + } + + return dst; +} + +/* + * Convert 16 bit Unicode pathname to wire format from string in current code + * page. Conversion may involve remapping up the six characters that are + * only legal in POSIX-like OS (if they are present in the string). Path + * names are little endian 16 bit Unicode on the wire + */ +int +cifsConvertToUTF16(__le16 *target, const char *source, int srclen, + const struct nls_table *cp, int mapChars) +{ + int i, j, charlen; + char src_char; + __le16 dst_char; + wchar_t tmp; + + if (!mapChars) + return cifs_strtoUTF16(target, source, PATH_MAX, cp); + + for (i = 0, j = 0; i < srclen; j++) { + src_char = source[i]; + charlen = 1; + switch (src_char) { + case 0: + put_unaligned(0, &target[j]); + goto ctoUTF16_out; + case ':': + dst_char = cpu_to_le16(UNI_COLON); + break; + case '*': + dst_char = cpu_to_le16(UNI_ASTERISK); + break; + case '?': + dst_char = cpu_to_le16(UNI_QUESTION); + break; + case '<': + dst_char = cpu_to_le16(UNI_LESSTHAN); + break; + case '>': + dst_char = cpu_to_le16(UNI_GRTRTHAN); + break; + case '|': + dst_char = cpu_to_le16(UNI_PIPE); + break; + /* + * FIXME: We can not handle remapping backslash (UNI_SLASH) + * until all the calls to build_path_from_dentry are modified, + * as they use backslash as separator. + */ + default: + charlen = cp->char2uni(source + i, srclen - i, &tmp); + dst_char = cpu_to_le16(tmp); + + /* + * if no match, use question mark, which at least in + * some cases serves as wild card + */ + if (charlen < 1) { + dst_char = cpu_to_le16(0x003f); + charlen = 1; + } + } + /* + * character may take more than one byte in the source string, + * but will take exactly two bytes in the target string + */ + i += charlen; + put_unaligned(dst_char, &target[j]); + } + +ctoUTF16_out: + return i; +} + |