fs/cifs/cifs_unicode.c - kernel/mindspeed - Git at Google

 /*
  *   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_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];
 	__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_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];
 	__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_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; /* 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, "strtoUCS: 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_ucs - 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_ucs(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;
 }

 /*
  * 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
 cifsConvertToUCS(__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_strtoUCS(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 ctoUCS_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]);
 	}

 ctoUCS_out:
 	return i;
 }
	/*
	* 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_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];
	__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_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];
	__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_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; /* 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, "strtoUCS: 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_ucs - 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_ucs(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;
	}

	/*
	* 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
	cifsConvertToUCS(__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_strtoUCS(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 ctoUCS_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]);
	}

	ctoUCS_out:
	return i;
	}