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402 lines
9.2 KiB
402 lines
9.2 KiB
/* |
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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_SB(sb)->s_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_SB(sb)->s_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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/* |
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* Convert CS0 dstring to output charset. Warning: This function may truncate |
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* input string if it is too long as it is used for informational strings only |
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* and it is better to truncate the string than to refuse mounting a media. |
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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_warn("incorrect dstring lengths (%d/%d)," |
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" truncating\n", s_len, i_len); |
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s_len = i_len - 1; |
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/* 2-byte encoding? Need to round properly... */ |
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if (ocu_i[0] == 16) |
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s_len -= (s_len - 1) & 2; |
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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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