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8a0cdef161
Add support to decode characters outside of Base Multilingual Plane of UTF-16 encoded in CS0 charset of UDF. Signed-off-by: Jan Kara <jack@suse.cz>
395 lines
8.9 KiB
C
395 lines
8.9 KiB
C
/*
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* unicode.c
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*
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* PURPOSE
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* Routines for converting between UTF-8 and OSTA Compressed Unicode.
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* Also handles filename mangling
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*
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* DESCRIPTION
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* OSTA Compressed Unicode is explained in the OSTA UDF specification.
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* http://www.osta.org/
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* UTF-8 is explained in the IETF RFC XXXX.
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* ftp://ftp.internic.net/rfc/rfcxxxx.txt
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*
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* COPYRIGHT
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* This file is distributed under the terms of the GNU General Public
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* License (GPL). Copies of the GPL can be obtained from:
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* ftp://prep.ai.mit.edu/pub/gnu/GPL
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* Each contributing author retains all rights to their own work.
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*/
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#include "udfdecl.h"
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#include <linux/kernel.h>
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#include <linux/string.h> /* for memset */
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#include <linux/nls.h>
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#include <linux/crc-itu-t.h>
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#include <linux/slab.h>
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#include "udf_sb.h"
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#define PLANE_SIZE 0x10000
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#define UNICODE_MAX 0x10ffff
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#define SURROGATE_MASK 0xfffff800
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#define SURROGATE_PAIR 0x0000d800
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#define SURROGATE_LOW 0x00000400
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#define SURROGATE_CHAR_BITS 10
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#define SURROGATE_CHAR_MASK ((1 << SURROGATE_CHAR_BITS) - 1)
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#define ILLEGAL_CHAR_MARK '_'
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#define EXT_MARK '.'
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#define CRC_MARK '#'
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#define EXT_SIZE 5
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/* Number of chars we need to store generated CRC to make filename unique */
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#define CRC_LEN 5
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static unicode_t get_utf16_char(const uint8_t *str_i, int str_i_max_len,
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int str_i_idx, int u_ch, unicode_t *ret)
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{
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unicode_t c;
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int start_idx = str_i_idx;
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/* Expand OSTA compressed Unicode to Unicode */
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c = str_i[str_i_idx++];
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if (u_ch > 1)
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c = (c << 8) | str_i[str_i_idx++];
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if ((c & SURROGATE_MASK) == SURROGATE_PAIR) {
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unicode_t next;
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/* Trailing surrogate char */
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if (str_i_idx >= str_i_max_len) {
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c = UNICODE_MAX + 1;
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goto out;
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}
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/* Low surrogate must follow the high one... */
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if (c & SURROGATE_LOW) {
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c = UNICODE_MAX + 1;
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goto out;
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}
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WARN_ON_ONCE(u_ch != 2);
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next = str_i[str_i_idx++] << 8;
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next |= str_i[str_i_idx++];
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if ((next & SURROGATE_MASK) != SURROGATE_PAIR ||
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!(next & SURROGATE_LOW)) {
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c = UNICODE_MAX + 1;
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goto out;
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}
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c = PLANE_SIZE +
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((c & SURROGATE_CHAR_MASK) << SURROGATE_CHAR_BITS) +
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(next & SURROGATE_CHAR_MASK);
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}
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out:
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*ret = c;
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return str_i_idx - start_idx;
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}
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static int udf_name_conv_char(uint8_t *str_o, int str_o_max_len,
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int *str_o_idx,
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const uint8_t *str_i, int str_i_max_len,
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int *str_i_idx,
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int u_ch, int *needsCRC,
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int (*conv_f)(wchar_t, unsigned char *, int),
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int translate)
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{
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unicode_t c;
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int illChar = 0;
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int len, gotch = 0;
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while (!gotch && *str_i_idx < str_i_max_len) {
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if (*str_o_idx >= str_o_max_len) {
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*needsCRC = 1;
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return gotch;
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}
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len = get_utf16_char(str_i, str_i_max_len, *str_i_idx, u_ch,
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&c);
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/* These chars cannot be converted. Replace them. */
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if (c == 0 || c > UNICODE_MAX || (conv_f && c > MAX_WCHAR_T) ||
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(translate && c == '/')) {
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illChar = 1;
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if (!translate)
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gotch = 1;
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} else if (illChar)
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break;
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else
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gotch = 1;
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*str_i_idx += len;
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}
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if (illChar) {
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*needsCRC = 1;
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c = ILLEGAL_CHAR_MARK;
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gotch = 1;
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}
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if (gotch) {
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if (conv_f) {
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len = conv_f(c, &str_o[*str_o_idx],
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str_o_max_len - *str_o_idx);
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} else {
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len = utf32_to_utf8(c, &str_o[*str_o_idx],
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str_o_max_len - *str_o_idx);
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if (len < 0)
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len = -ENAMETOOLONG;
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}
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/* Valid character? */
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if (len >= 0)
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*str_o_idx += len;
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else if (len == -ENAMETOOLONG) {
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*needsCRC = 1;
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gotch = 0;
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} else {
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str_o[(*str_o_idx)++] = ILLEGAL_CHAR_MARK;
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*needsCRC = 1;
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}
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}
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return gotch;
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}
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static int udf_name_from_CS0(struct super_block *sb,
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uint8_t *str_o, int str_max_len,
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const uint8_t *ocu, int ocu_len,
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int translate)
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{
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uint32_t c;
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uint8_t cmp_id;
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int idx, len;
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int u_ch;
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int needsCRC = 0;
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int ext_i_len, ext_max_len;
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int str_o_len = 0; /* Length of resulting output */
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int ext_o_len = 0; /* Extension output length */
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int ext_crc_len = 0; /* Extension output length if used with CRC */
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int i_ext = -1; /* Extension position in input buffer */
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int o_crc = 0; /* Rightmost possible output pos for CRC+ext */
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unsigned short valueCRC;
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uint8_t ext[EXT_SIZE * NLS_MAX_CHARSET_SIZE + 1];
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uint8_t crc[CRC_LEN];
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int (*conv_f)(wchar_t, unsigned char *, int);
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if (str_max_len <= 0)
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return 0;
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if (ocu_len == 0) {
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memset(str_o, 0, str_max_len);
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return 0;
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}
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if (UDF_QUERY_FLAG(sb, UDF_FLAG_NLS_MAP))
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conv_f = UDF_SB(sb)->s_nls_map->uni2char;
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else
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conv_f = NULL;
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cmp_id = ocu[0];
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if (cmp_id != 8 && cmp_id != 16) {
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memset(str_o, 0, str_max_len);
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pr_err("unknown compression code (%u)\n", cmp_id);
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return -EINVAL;
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}
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u_ch = cmp_id >> 3;
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ocu++;
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ocu_len--;
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if (ocu_len % u_ch) {
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pr_err("incorrect filename length (%d)\n", ocu_len + 1);
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return -EINVAL;
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}
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if (translate) {
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/* Look for extension */
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for (idx = ocu_len - u_ch, ext_i_len = 0;
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(idx >= 0) && (ext_i_len < EXT_SIZE);
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idx -= u_ch, ext_i_len++) {
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c = ocu[idx];
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if (u_ch > 1)
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c = (c << 8) | ocu[idx + 1];
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if (c == EXT_MARK) {
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if (ext_i_len)
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i_ext = idx;
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break;
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}
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}
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if (i_ext >= 0) {
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/* Convert extension */
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ext_max_len = min_t(int, sizeof(ext), str_max_len);
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ext[ext_o_len++] = EXT_MARK;
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idx = i_ext + u_ch;
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while (udf_name_conv_char(ext, ext_max_len, &ext_o_len,
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ocu, ocu_len, &idx,
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u_ch, &needsCRC,
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conv_f, translate)) {
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if ((ext_o_len + CRC_LEN) < str_max_len)
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ext_crc_len = ext_o_len;
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}
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}
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}
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idx = 0;
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while (1) {
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if (translate && (idx == i_ext)) {
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if (str_o_len > (str_max_len - ext_o_len))
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needsCRC = 1;
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break;
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}
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if (!udf_name_conv_char(str_o, str_max_len, &str_o_len,
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ocu, ocu_len, &idx,
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u_ch, &needsCRC, conv_f, translate))
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break;
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if (translate &&
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(str_o_len <= (str_max_len - ext_o_len - CRC_LEN)))
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o_crc = str_o_len;
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}
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if (translate) {
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if (str_o_len <= 2 && str_o[0] == '.' &&
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(str_o_len == 1 || str_o[1] == '.'))
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needsCRC = 1;
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if (needsCRC) {
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str_o_len = o_crc;
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valueCRC = crc_itu_t(0, ocu, ocu_len);
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crc[0] = CRC_MARK;
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crc[1] = hex_asc_upper_hi(valueCRC >> 8);
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crc[2] = hex_asc_upper_lo(valueCRC >> 8);
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crc[3] = hex_asc_upper_hi(valueCRC);
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crc[4] = hex_asc_upper_lo(valueCRC);
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len = min_t(int, CRC_LEN, str_max_len - str_o_len);
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memcpy(&str_o[str_o_len], crc, len);
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str_o_len += len;
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ext_o_len = ext_crc_len;
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}
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if (ext_o_len > 0) {
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memcpy(&str_o[str_o_len], ext, ext_o_len);
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str_o_len += ext_o_len;
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}
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}
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return str_o_len;
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}
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static int udf_name_to_CS0(struct super_block *sb,
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uint8_t *ocu, int ocu_max_len,
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const uint8_t *str_i, int str_len)
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{
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int i, len;
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unsigned int max_val;
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int u_len, u_ch;
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unicode_t uni_char;
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int (*conv_f)(const unsigned char *, int, wchar_t *);
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if (ocu_max_len <= 0)
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return 0;
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if (UDF_QUERY_FLAG(sb, UDF_FLAG_NLS_MAP))
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conv_f = UDF_SB(sb)->s_nls_map->char2uni;
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else
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conv_f = NULL;
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memset(ocu, 0, ocu_max_len);
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ocu[0] = 8;
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max_val = 0xff;
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u_ch = 1;
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try_again:
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u_len = 1;
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for (i = 0; i < str_len; i += len) {
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/* Name didn't fit? */
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if (u_len + u_ch > ocu_max_len)
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return 0;
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if (conv_f) {
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wchar_t wchar;
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len = conv_f(&str_i[i], str_len - i, &wchar);
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if (len > 0)
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uni_char = wchar;
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} else {
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len = utf8_to_utf32(&str_i[i], str_len - i,
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&uni_char);
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}
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/* Invalid character, deal with it */
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if (len <= 0 || uni_char > UNICODE_MAX) {
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len = 1;
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uni_char = '?';
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}
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if (uni_char > max_val) {
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unicode_t c;
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if (max_val == 0xff) {
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max_val = 0xffff;
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ocu[0] = 0x10;
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u_ch = 2;
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goto try_again;
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}
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/*
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* Use UTF-16 encoding for chars outside we
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* cannot encode directly.
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*/
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if (u_len + 2 * u_ch > ocu_max_len)
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return 0;
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uni_char -= PLANE_SIZE;
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c = SURROGATE_PAIR |
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((uni_char >> SURROGATE_CHAR_BITS) &
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SURROGATE_CHAR_MASK);
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ocu[u_len++] = (uint8_t)(c >> 8);
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ocu[u_len++] = (uint8_t)(c & 0xff);
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uni_char = SURROGATE_PAIR | SURROGATE_LOW |
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(uni_char & SURROGATE_CHAR_MASK);
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}
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if (max_val == 0xffff)
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ocu[u_len++] = (uint8_t)(uni_char >> 8);
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ocu[u_len++] = (uint8_t)(uni_char & 0xff);
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}
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return u_len;
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}
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int udf_dstrCS0toChar(struct super_block *sb, uint8_t *utf_o, int o_len,
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const uint8_t *ocu_i, int i_len)
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{
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int s_len = 0;
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if (i_len > 0) {
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s_len = ocu_i[i_len - 1];
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if (s_len >= i_len) {
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pr_err("incorrect dstring lengths (%d/%d)\n",
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s_len, i_len);
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return -EINVAL;
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}
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}
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return udf_name_from_CS0(sb, utf_o, o_len, ocu_i, s_len, 0);
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}
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int udf_get_filename(struct super_block *sb, const uint8_t *sname, int slen,
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uint8_t *dname, int dlen)
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{
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int ret;
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if (!slen)
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return -EIO;
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if (dlen <= 0)
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return 0;
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ret = udf_name_from_CS0(sb, dname, dlen, sname, slen, 1);
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/* Zero length filename isn't valid... */
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if (ret == 0)
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ret = -EINVAL;
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return ret;
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}
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int udf_put_filename(struct super_block *sb, const uint8_t *sname, int slen,
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uint8_t *dname, int dlen)
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{
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return udf_name_to_CS0(sb, dname, dlen, sname, slen);
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}
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