linux/fs/cifs/cifs_unicode.c
Jeff Layton 066ce68994 cifs: rename cifs_strlcpy_to_host and make it use new functions
Rename cifs_strlcpy_to_host to cifs_strndup since that better describes
what this function really does. Then, convert it to use the new string
conversion and measurement functions that work in units of bytes rather
than wide chars.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2009-04-30 15:45:00 +00:00

284 lines
7.5 KiB
C

/*
* fs/cifs/cifs_unicode.c
*
* Copyright (c) International Business Machines Corp., 2000,2005
* 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 "cifs_unicode.h"
#include "cifs_uniupr.h"
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifs_debug.h"
/*
* cifs_ucs2_bytes - how long will a string be after conversion?
* @ucs - pointer to input string
* @maxbytes - don't go past this many bytes of input string
* @codepage - destination codepage
*
* Walk a ucs2le 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_ucs2_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];
for (i = 0; from[i] && i < maxwords; i++) {
charlen = codepage->uni2char(le16_to_cpu(from[i]), tmp,
NLS_MAX_CHARSET_SIZE);
if (charlen > 0)
outlen += charlen;
else
outlen++;
}
return outlen;
}
/*
* cifs_mapchar - convert a little-endian char to proper char in codepage
* @target - where converted character should be copied
* @src_char - 2 byte little-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 __le16 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 (le16_to_cpu(src_char)) {
case UNI_COLON:
*target = ':';
break;
case UNI_ASTERIK:
*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(le16_to_cpu(src_char), target,
NLS_MAX_CHARSET_SIZE);
if (len <= 0) {
*target = '?';
len = 1;
}
goto out;
}
/*
* cifs_from_ucs2 - 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 ucs2le 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 UCS-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_ucs2(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];
/*
* 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 && from[i]; i++) {
/*
* check to see if converting this character might make the
* conversion bleed into the null terminator
*/
if (outlen >= safelen) {
charlen = cifs_mapchar(tmp, from[i], codepage, mapchar);
if ((outlen + charlen) > (tolen - nullsize))
break;
}
/* put converted char into 'to' buffer */
charlen = cifs_mapchar(&to[outlen], from[i], codepage, mapchar);
outlen += charlen;
}
/* properly null-terminate string */
for (i = 0; i < nullsize; i++)
to[outlen++] = 0;
return outlen;
}
/*
* NAME: cifs_strfromUCS()
*
* FUNCTION: Convert little-endian unicode string to character string
*
*/
int
cifs_strfromUCS_le(char *to, const __le16 *from,
int len, const struct nls_table *codepage)
{
int i;
int outlen = 0;
for (i = 0; (i < len) && from[i]; i++) {
int charlen;
/* 2.4.0 kernel or greater */
charlen =
codepage->uni2char(le16_to_cpu(from[i]), &to[outlen],
NLS_MAX_CHARSET_SIZE);
if (charlen > 0) {
outlen += charlen;
} else {
to[outlen++] = '?';
}
}
to[outlen] = 0;
return outlen;
}
/*
* NAME: cifs_strtoUCS()
*
* FUNCTION: Convert character string to unicode string
*
*/
int
cifs_strtoUCS(__le16 *to, const char *from, int len,
const struct nls_table *codepage)
{
int charlen;
int i;
wchar_t *wchar_to = (wchar_t *)to; /* needed to quiet sparse */
for (i = 0; len && *from; i++, from += charlen, len -= charlen) {
/* works for 2.4.0 kernel or later */
charlen = codepage->char2uni(from, len, &wchar_to[i]);
if (charlen < 1) {
cERROR(1,
("strtoUCS: char2uni of %d returned %d",
(int)*from, charlen));
/* A question mark */
to[i] = cpu_to_le16(0x003f);
charlen = 1;
} else
to[i] = cpu_to_le16(wchar_to[i]);
}
to[i] = 0;
return i;
}
/*
* cifs_strndup - 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(const char *src, const int maxlen, const bool is_unicode,
const struct nls_table *codepage)
{
int len;
char *dst;
if (is_unicode) {
len = cifs_ucs2_bytes((__le16 *) src, maxlen, codepage);
len += nls_nullsize(codepage);
dst = kmalloc(len, GFP_KERNEL);
if (!dst)
return NULL;
cifs_from_ucs2(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;
}