- 根目录:
- fs
- ntfs
- unistr.c
/*
* unistr.c - NTFS Unicode string handling. Part of the Linux-NTFS project.
*
* Copyright (c) 2001-2006 Anton Altaparmakov
*
* This program/include file 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/include file 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 (in the main directory of the Linux-NTFS
* distribution in the file COPYING); if not, write to the Free Software
* Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/slab.h>
#include "types.h"
#include "debug.h"
#include "ntfs.h"
/*
* IMPORTANT
* =========
*
* All these routines assume that the Unicode characters are in little endian
* encoding inside the strings!!!
*/
/*
* This is used by the name collation functions to quickly determine what
* characters are (in)valid.
*/
static const u8 legal_ansi_char_array[0x40] = {
0x00, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
0x17, 0x07, 0x18, 0x17, 0x17, 0x17, 0x17, 0x17,
0x17, 0x17, 0x18, 0x16, 0x16, 0x17, 0x07, 0x00,
0x17, 0x17, 0x17, 0x17, 0x17, 0x17, 0x17, 0x17,
0x17, 0x17, 0x04, 0x16, 0x18, 0x16, 0x18, 0x18,
};
/**
* ntfs_are_names_equal - compare two Unicode names for equality
* @s1: name to compare to @s2
* @s1_len: length in Unicode characters of @s1
* @s2: name to compare to @s1
* @s2_len: length in Unicode characters of @s2
* @ic: ignore case bool
* @upcase: upcase table (only if @ic == IGNORE_CASE)
* @upcase_size: length in Unicode characters of @upcase (if present)
*
* Compare the names @s1 and @s2 and return 'true' (1) if the names are
* identical, or 'false' (0) if they are not identical. If @ic is IGNORE_CASE,
* the @upcase table is used to performa a case insensitive comparison.
*/
bool ntfs_are_names_equal(const ntfschar *s1, size_t s1_len,
const ntfschar *s2, size_t s2_len, const IGNORE_CASE_BOOL ic,
const ntfschar *upcase, const u32 upcase_size)
{
if (s1_len != s2_len)
return false;
if (ic == CASE_SENSITIVE)
return !ntfs_ucsncmp(s1, s2, s1_len);
return !ntfs_ucsncasecmp(s1, s2, s1_len, upcase, upcase_size);
}
/**
* ntfs_collate_names - collate two Unicode names
* @name1: first Unicode name to compare
* @name2: second Unicode name to compare
* @err_val: if @name1 contains an invalid character return this value
* @ic: either CASE_SENSITIVE or IGNORE_CASE
* @upcase: upcase table (ignored if @ic is CASE_SENSITIVE)
* @upcase_len: upcase table size (ignored if @ic is CASE_SENSITIVE)
*
* ntfs_collate_names collates two Unicode names and returns:
*
* -1 if the first name collates before the second one,
* 0 if the names match,
* 1 if the second name collates before the first one, or
* @err_val if an invalid character is found in @name1 during the comparison.
*
* The following characters are considered invalid: '"', '*', '<', '>' and '?'.
*/
int ntfs_collate_names(const ntfschar *name1, const u32 name1_len,
const ntfschar *name2, const u32 name2_len,
const int err_val, const IGNORE_CASE_BOOL ic,
const ntfschar *upcase, const u32 upcase_len)
{
u32 cnt, min_len;
u16 c1, c2;
min_len = name1_len;
if (name1_len > name2_len)
min_len = name2_len;
for (cnt = 0; cnt < min_len; ++cnt) {
c1 = le16_to_cpu(*name1++);
c2 = le16_to_cpu(*name2++);
if (ic) {
if (c1 < upcase_len)
c1 = le16_to_cpu(upcase[c1]);
if (c2 < upcase_len)
c2 = le16_to_cpu(upcase[c2]);
}
if (c1 < 64 && legal_ansi_char_array[c1] & 8)
return err_val;
if (c1 < c2)
return -1;
if (c1 > c2)
return 1;
}
if (name1_len < name2_len)
return -1;
if (name1_len == name2_len)
return 0;
/* name1_len > name2_len */
c1 = le16_to_cpu(*name1);
if (c1 < 64 && legal_ansi_char_array[c1] & 8)
return err_val;
return 1;
}
/**
* ntfs_ucsncmp - compare two little endian Unicode strings
* @s1: first string
* @s2: second string
* @n: maximum unicode characters to compare
*
* Compare the first @n characters of the Unicode strings @s1 and @s2,
* The strings in little endian format and appropriate le16_to_cpu()
* conversion is performed on non-little endian machines.
*
* The function returns an integer less than, equal to, or greater than zero
* if @s1 (or the first @n Unicode characters thereof) is found, respectively,
* to be less than, to match, or be greater than @s2.
*/
int ntfs_ucsncmp(const ntfschar *s1, const ntfschar *s2, size_t n)
{
u16 c1, c2;
size_t i;
for (i = 0; i < n; ++i) {
c1 = le16_to_cpu(s1[i]);
c2 = le16_to_cpu(s2[i]);
if (c1 < c2)
return -1;
if (c1 > c2)
return 1;
if (!c1)
break;
}
return 0;
}
/**
* ntfs_ucsncasecmp - compare two little endian Unicode strings, ignoring case
* @s1: first string
* @s2: second string
* @n: maximum unicode characters to compare
* @upcase: upcase table
* @upcase_size: upcase table size in Unicode characters
*
* Compare the first @n characters of the Unicode strings @s1 and @s2,
* ignoring case. The strings in little endian format and appropriate
* le16_to_cpu() conversion is performed on non-little endian machines.
*
* Each character is uppercased using the @upcase table before the comparison.
*
* The function returns an integer less than, equal to, or greater than zero
* if @s1 (or the first @n Unicode characters thereof) is found, respectively,
* to be less than, to match, or be greater than @s2.
*/
int ntfs_ucsncasecmp(const ntfschar *s1, const ntfschar *s2, size_t n,
const ntfschar *upcase, const u32 upcase_size)
{
size_t i;
u16 c1, c2;
for (i = 0; i < n; ++i) {
if ((c1 = le16_to_cpu(s1[i])) < upcase_size)
c1 = le16_to_cpu(upcase[c1]);
if ((c2 = le16_to_cpu(s2[i])) < upcase_size)
c2 = le16_to_cpu(upcase[c2]);
if (c1 < c2)
return -1;
if (c1 > c2)
return 1;
if (!c1)
break;
}
return 0;
}
void ntfs_upcase_name(ntfschar *name, u32 name_len, const ntfschar *upcase,
const u32 upcase_len)
{
u32 i;
u16 u;
for (i = 0; i < name_len; i++)
if ((u = le16_to_cpu(name[i])) < upcase_len)
name[i] = upcase[u];
}
void ntfs_file_upcase_value(FILE_NAME_ATTR *file_name_attr,
const ntfschar *upcase, const u32 upcase_len)
{
ntfs_upcase_name((ntfschar*)&file_name_attr->file_name,
file_name_attr->file_name_length, upcase, upcase_len);
}
int ntfs_file_compare_values(FILE_NAME_ATTR *file_name_attr1,
FILE_NAME_ATTR *file_name_attr2,
const int err_val, const IGNORE_CASE_BOOL ic,
const ntfschar *upcase, const u32 upcase_len)
{
return ntfs_collate_names((ntfschar*)&file_name_attr1->file_name,
file_name_attr1->file_name_length,
(ntfschar*)&file_name_attr2->file_name,
file_name_attr2->file_name_length,
err_val, ic, upcase, upcase_len);
}
/**
* ntfs_nlstoucs - convert NLS string to little endian Unicode string
* @vol: ntfs volume which we are working with
* @ins: input NLS string buffer
* @ins_len: length of input string in bytes
* @outs: on return contains the allocated output Unicode string buffer
*
* Convert the input string @ins, which is in whatever format the loaded NLS
* map dictates, into a little endian, 2-byte Unicode string.
*
* This function allocates the string and the caller is responsible for
* calling kmem_cache_free(ntfs_name_cache, *@outs); when finished with it.
*
* On success the function returns the number of Unicode characters written to
* the output string *@outs (>= 0), not counting the terminating Unicode NULL
* character. *@outs is set to the allocated output string buffer.
*
* On error, a negative number corresponding to the error code is returned. In
* that case the output string is not allocated. Both *@outs and *@outs_len
* are then undefined.
*
* This might look a bit odd due to fast path optimization...
*/
int ntfs_nlstoucs(const ntfs_volume *vol, const char *ins,
const int ins_len, ntfschar **outs)
{
struct nls_table *nls = vol->nls_map;
ntfschar *ucs;
wchar_t wc;
int i, o, wc_len;
/* We do not trust outside sources. */
if (likely(ins)) {
ucs = kmem_cache_alloc(ntfs_name_cache, GFP_NOFS);
if (likely(ucs)) {
for (i = o = 0; i < ins_len; i += wc_len) {
wc_len = nls->char2uni(ins + i, ins_len - i,
&wc);
if (likely(wc_len >= 0 &&
o < NTFS_MAX_NAME_LEN)) {
if (likely(wc)) {
ucs[o++] = cpu_to_le16(wc);
continue;
} /* else if (!wc) */
break;
} /* else if (wc_len < 0 ||
o >= NTFS_MAX_NAME_LEN) */
goto name_err;
}
ucs[o] = 0;
*outs = ucs;
return o;
} /* else if (!ucs) */
ntfs_error(vol->sb, "Failed to allocate buffer for converted "
"name from ntfs_name_cache.");
return -ENOMEM;
} /* else if (!ins) */
ntfs_error(vol->sb, "Received NULL pointer.");
return -EINVAL;
name_err:
kmem_cache_free(ntfs_name_cache, ucs);
if (wc_len < 0) {
ntfs_error(vol->sb, "Name using character set %s contains "
"characters that cannot be converted to "
"Unicode.", nls->charset);
i = -EILSEQ;
} else /* if (o >= NTFS_MAX_NAME_LEN) */ {
ntfs_error(vol->sb, "Name is too long (maximum length for a "
"name on NTFS is %d Unicode characters.",
NTFS_MAX_NAME_LEN);
i = -ENAMETOOLONG;
}
return i;
}
/**
* ntfs_ucstonls - convert little endian Unicode string to NLS string
* @vol: ntfs volume which we are working with
* @ins: input Unicode string buffer
* @ins_len: length of input string in Unicode characters
* @outs: on return contains the (allocated) output NLS string buffer
* @outs_len: length of output string buffer in bytes
*
* Convert the input little endian, 2-byte Unicode string @ins, of length
* @ins_len into the string format dictated by the loaded NLS.
*
* If *@outs is NULL, this function allocates the string and the caller is
* responsible for calling kfree(*@outs); when finished with it. In this case
* @outs_len is ignored and can be 0.
*
* On success the function returns the number of bytes written to the output
* string *@outs (>= 0), not counting the terminating NULL byte. If the output
* string buffer was allocated, *@outs is set to it.
*
* On error, a negative number corresponding to the error code is returned. In
* that case the output string is not allocated. The contents of *@outs are
* then undefined.
*
* This might look a bit odd due to fast path optimization...
*/
int ntfs_ucstonls(const ntfs_volume *vol, const ntfschar *ins,
const int ins_len, unsigned char **outs, int outs_len)
{
struct nls_table *nls = vol->nls_map;
unsigned char *ns;
int i, o, ns_len, wc;
/* We don't trust outside sources. */
if (ins) {
ns = *outs;
ns_len = outs_len;
if (ns && !ns_len) {
wc = -ENAMETOOLONG;
goto conversion_err;
}
if (!ns) {
ns_len = ins_len * NLS_MAX_CHARSET_SIZE;
ns = kmalloc(ns_len + 1, GFP_NOFS);
if (!ns)
goto mem_err_out;
}
for (i = o = 0; i < ins_len; i++) {
retry: wc = nls->uni2char(le16_to_cpu(ins[i]), ns + o,
ns_len - o);
if (wc > 0) {
o += wc;
continue;
} else if (!wc)
break;
else if (wc == -ENAMETOOLONG && ns != *outs) {
unsigned char *tc;
/* Grow in multiples of 64 bytes. */
tc = kmalloc((ns_len + 64) &
~63, GFP_NOFS);
if (tc) {
memcpy(tc, ns, ns_len);
ns_len = ((ns_len + 64) & ~63) - 1;
kfree(ns);
ns = tc;
goto retry;
} /* No memory so goto conversion_error; */
} /* wc < 0, real error. */
goto conversion_err;
}
ns[o] = 0;
*outs = ns;
return o;
} /* else (!ins) */
ntfs_error(vol->sb, "Received NULL pointer.");
return -EINVAL;
conversion_err:
ntfs_error(vol->sb, "Unicode name contains characters that cannot be "
"converted to character set %s. You might want to "
"try to use the mount option nls=utf8.", nls->charset);
if (ns != *outs)
kfree(ns);
if (wc != -ENAMETOOLONG)
wc = -EILSEQ;
return wc;
mem_err_out:
ntfs_error(vol->sb, "Failed to allocate name!");
return -ENOMEM;
}