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OpenCloudOS-Kernel/fs/udf/unicode.c

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/*
* unicode.c
*
* PURPOSE
* Routines for converting between UTF-8 and OSTA Compressed Unicode.
* Also handles filename mangling
*
* DESCRIPTION
* OSTA Compressed Unicode is explained in the OSTA UDF specification.
* http://www.osta.org/
* UTF-8 is explained in the IETF RFC XXXX.
* ftp://ftp.internic.net/rfc/rfcxxxx.txt
*
* COPYRIGHT
* This file is distributed under the terms of the GNU General Public
* License (GPL). Copies of the GPL can be obtained from:
* ftp://prep.ai.mit.edu/pub/gnu/GPL
* Each contributing author retains all rights to their own work.
*/
#include "udfdecl.h"
#include <linux/kernel.h>
#include <linux/string.h> /* for memset */
#include <linux/nls.h>
#include <linux/crc-itu-t.h>
#include <linux/slab.h>
#include "udf_sb.h"
#define PLANE_SIZE 0x10000
#define UNICODE_MAX 0x10ffff
#define SURROGATE_MASK 0xfffff800
#define SURROGATE_PAIR 0x0000d800
#define SURROGATE_LOW 0x00000400
#define SURROGATE_CHAR_BITS 10
#define SURROGATE_CHAR_MASK ((1 << SURROGATE_CHAR_BITS) - 1)
#define ILLEGAL_CHAR_MARK '_'
#define EXT_MARK '.'
#define CRC_MARK '#'
#define EXT_SIZE 5
/* Number of chars we need to store generated CRC to make filename unique */
#define CRC_LEN 5
static unicode_t get_utf16_char(const uint8_t *str_i, int str_i_max_len,
int str_i_idx, int u_ch, unicode_t *ret)
{
unicode_t c;
int start_idx = str_i_idx;
/* Expand OSTA compressed Unicode to Unicode */
c = str_i[str_i_idx++];
if (u_ch > 1)
c = (c << 8) | str_i[str_i_idx++];
if ((c & SURROGATE_MASK) == SURROGATE_PAIR) {
unicode_t next;
/* Trailing surrogate char */
if (str_i_idx >= str_i_max_len) {
c = UNICODE_MAX + 1;
goto out;
}
/* Low surrogate must follow the high one... */
if (c & SURROGATE_LOW) {
c = UNICODE_MAX + 1;
goto out;
}
WARN_ON_ONCE(u_ch != 2);
next = str_i[str_i_idx++] << 8;
next |= str_i[str_i_idx++];
if ((next & SURROGATE_MASK) != SURROGATE_PAIR ||
!(next & SURROGATE_LOW)) {
c = UNICODE_MAX + 1;
goto out;
}
c = PLANE_SIZE +
((c & SURROGATE_CHAR_MASK) << SURROGATE_CHAR_BITS) +
(next & SURROGATE_CHAR_MASK);
}
out:
*ret = c;
return str_i_idx - start_idx;
}
static int udf_name_conv_char(uint8_t *str_o, int str_o_max_len,
int *str_o_idx,
const uint8_t *str_i, int str_i_max_len,
int *str_i_idx,
int u_ch, int *needsCRC,
int (*conv_f)(wchar_t, unsigned char *, int),
int translate)
{
unicode_t c;
int illChar = 0;
int len, gotch = 0;
while (!gotch && *str_i_idx < str_i_max_len) {
if (*str_o_idx >= str_o_max_len) {
*needsCRC = 1;
return gotch;
}
len = get_utf16_char(str_i, str_i_max_len, *str_i_idx, u_ch,
&c);
/* These chars cannot be converted. Replace them. */
if (c == 0 || c > UNICODE_MAX || (conv_f && c > MAX_WCHAR_T) ||
(translate && c == '/')) {
illChar = 1;
if (!translate)
gotch = 1;
} else if (illChar)
break;
else
gotch = 1;
*str_i_idx += len;
}
if (illChar) {
*needsCRC = 1;
c = ILLEGAL_CHAR_MARK;
gotch = 1;
}
if (gotch) {
if (conv_f) {
len = conv_f(c, &str_o[*str_o_idx],
str_o_max_len - *str_o_idx);
} else {
len = utf32_to_utf8(c, &str_o[*str_o_idx],
str_o_max_len - *str_o_idx);
if (len < 0)
len = -ENAMETOOLONG;
}
/* Valid character? */
if (len >= 0)
*str_o_idx += len;
else if (len == -ENAMETOOLONG) {
*needsCRC = 1;
gotch = 0;
} else {
str_o[(*str_o_idx)++] = ILLEGAL_CHAR_MARK;
*needsCRC = 1;
}
}
return gotch;
}
static int udf_name_from_CS0(struct super_block *sb,
uint8_t *str_o, int str_max_len,
const uint8_t *ocu, int ocu_len,
int translate)
{
uint32_t c;
uint8_t cmp_id;
int idx, len;
int u_ch;
int needsCRC = 0;
int ext_i_len, ext_max_len;
int str_o_len = 0; /* Length of resulting output */
int ext_o_len = 0; /* Extension output length */
int ext_crc_len = 0; /* Extension output length if used with CRC */
int i_ext = -1; /* Extension position in input buffer */
int o_crc = 0; /* Rightmost possible output pos for CRC+ext */
unsigned short valueCRC;
uint8_t ext[EXT_SIZE * NLS_MAX_CHARSET_SIZE + 1];
uint8_t crc[CRC_LEN];
int (*conv_f)(wchar_t, unsigned char *, int);
if (str_max_len <= 0)
return 0;
if (ocu_len == 0) {
memset(str_o, 0, str_max_len);
return 0;
}
if (UDF_QUERY_FLAG(sb, UDF_FLAG_NLS_MAP))
conv_f = UDF_SB(sb)->s_nls_map->uni2char;
else
conv_f = NULL;
cmp_id = ocu[0];
if (cmp_id != 8 && cmp_id != 16) {
memset(str_o, 0, str_max_len);
pr_err("unknown compression code (%u)\n", cmp_id);
return -EINVAL;
}
u_ch = cmp_id >> 3;
ocu++;
ocu_len--;
if (ocu_len % u_ch) {
pr_err("incorrect filename length (%d)\n", ocu_len + 1);
return -EINVAL;
}
if (translate) {
/* Look for extension */
for (idx = ocu_len - u_ch, ext_i_len = 0;
(idx >= 0) && (ext_i_len < EXT_SIZE);
idx -= u_ch, ext_i_len++) {
c = ocu[idx];
if (u_ch > 1)
c = (c << 8) | ocu[idx + 1];
if (c == EXT_MARK) {
if (ext_i_len)
i_ext = idx;
break;
}
}
if (i_ext >= 0) {
/* Convert extension */
ext_max_len = min_t(int, sizeof(ext), str_max_len);
ext[ext_o_len++] = EXT_MARK;
idx = i_ext + u_ch;
while (udf_name_conv_char(ext, ext_max_len, &ext_o_len,
ocu, ocu_len, &idx,
u_ch, &needsCRC,
conv_f, translate)) {
if ((ext_o_len + CRC_LEN) < str_max_len)
ext_crc_len = ext_o_len;
}
}
}
idx = 0;
while (1) {
if (translate && (idx == i_ext)) {
if (str_o_len > (str_max_len - ext_o_len))
needsCRC = 1;
break;
}
if (!udf_name_conv_char(str_o, str_max_len, &str_o_len,
ocu, ocu_len, &idx,
u_ch, &needsCRC, conv_f, translate))
break;
if (translate &&
(str_o_len <= (str_max_len - ext_o_len - CRC_LEN)))
o_crc = str_o_len;
}
if (translate) {
if (str_o_len <= 2 && str_o[0] == '.' &&
(str_o_len == 1 || str_o[1] == '.'))
needsCRC = 1;
if (needsCRC) {
str_o_len = o_crc;
valueCRC = crc_itu_t(0, ocu, ocu_len);
crc[0] = CRC_MARK;
crc[1] = hex_asc_upper_hi(valueCRC >> 8);
crc[2] = hex_asc_upper_lo(valueCRC >> 8);
crc[3] = hex_asc_upper_hi(valueCRC);
crc[4] = hex_asc_upper_lo(valueCRC);
len = min_t(int, CRC_LEN, str_max_len - str_o_len);
memcpy(&str_o[str_o_len], crc, len);
str_o_len += len;
ext_o_len = ext_crc_len;
}
if (ext_o_len > 0) {
memcpy(&str_o[str_o_len], ext, ext_o_len);
str_o_len += ext_o_len;
}
}
return str_o_len;
}
static int udf_name_to_CS0(struct super_block *sb,
uint8_t *ocu, int ocu_max_len,
const uint8_t *str_i, int str_len)
{
int i, len;
unsigned int max_val;
int u_len, u_ch;
unicode_t uni_char;
int (*conv_f)(const unsigned char *, int, wchar_t *);
if (ocu_max_len <= 0)
return 0;
if (UDF_QUERY_FLAG(sb, UDF_FLAG_NLS_MAP))
conv_f = UDF_SB(sb)->s_nls_map->char2uni;
else
conv_f = NULL;
memset(ocu, 0, ocu_max_len);
ocu[0] = 8;
max_val = 0xff;
u_ch = 1;
try_again:
u_len = 1;
for (i = 0; i < str_len; i += len) {
/* Name didn't fit? */
if (u_len + u_ch > ocu_max_len)
return 0;
if (conv_f) {
wchar_t wchar;
len = conv_f(&str_i[i], str_len - i, &wchar);
if (len > 0)
uni_char = wchar;
} else {
len = utf8_to_utf32(&str_i[i], str_len - i,
&uni_char);
}
/* Invalid character, deal with it */
if (len <= 0 || uni_char > UNICODE_MAX) {
len = 1;
uni_char = '?';
}
if (uni_char > max_val) {
unicode_t c;
if (max_val == 0xff) {
max_val = 0xffff;
ocu[0] = 0x10;
u_ch = 2;
goto try_again;
}
/*
* Use UTF-16 encoding for chars outside we
* cannot encode directly.
*/
if (u_len + 2 * u_ch > ocu_max_len)
return 0;
uni_char -= PLANE_SIZE;
c = SURROGATE_PAIR |
((uni_char >> SURROGATE_CHAR_BITS) &
SURROGATE_CHAR_MASK);
ocu[u_len++] = (uint8_t)(c >> 8);
ocu[u_len++] = (uint8_t)(c & 0xff);
uni_char = SURROGATE_PAIR | SURROGATE_LOW |
(uni_char & SURROGATE_CHAR_MASK);
}
if (max_val == 0xffff)
ocu[u_len++] = (uint8_t)(uni_char >> 8);
ocu[u_len++] = (uint8_t)(uni_char & 0xff);
}
return u_len;
}
/*
* Convert CS0 dstring to output charset. Warning: This function may truncate
* input string if it is too long as it is used for informational strings only
* and it is better to truncate the string than to refuse mounting a media.
*/
int udf_dstrCS0toChar(struct super_block *sb, uint8_t *utf_o, int o_len,
const uint8_t *ocu_i, int i_len)
{
int s_len = 0;
if (i_len > 0) {
s_len = ocu_i[i_len - 1];
if (s_len >= i_len) {
pr_warn("incorrect dstring lengths (%d/%d),"
" truncating\n", s_len, i_len);
s_len = i_len - 1;
/* 2-byte encoding? Need to round properly... */
if (ocu_i[0] == 16)
s_len -= (s_len - 1) & 2;
}
}
return udf_name_from_CS0(sb, utf_o, o_len, ocu_i, s_len, 0);
}
int udf_get_filename(struct super_block *sb, const uint8_t *sname, int slen,
uint8_t *dname, int dlen)
{
int ret;
if (!slen)
return -EIO;
if (dlen <= 0)
return 0;
ret = udf_name_from_CS0(sb, dname, dlen, sname, slen, 1);
/* Zero length filename isn't valid... */
if (ret == 0)
ret = -EINVAL;
return ret;
}
int udf_put_filename(struct super_block *sb, const uint8_t *sname, int slen,
uint8_t *dname, int dlen)
{
return udf_name_to_CS0(sb, dname, dlen, sname, slen);
}
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