Commit 8a0cdef1 authored by Jan Kara's avatar Jan Kara
Browse files

udf: Add support for decoding UTF-16 characters 



Add support to decode characters outside of Base Multilingual Plane of
UTF-16 encoded in CS0 charset of UDF.

Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent ef2e18f1

fs/udf/unicode.c

+68 −35
Original line number Diff line number Diff line
@@ -36,25 +36,6 @@ 
#define SURROGATE_CHAR_BITS 10

#define SURROGATE_CHAR_MASK ((1 << SURROGATE_CHAR_BITS) - 1)



static int udf_uni2char_utf8(wchar_t uni,

			     unsigned char *out,

			     int boundlen)

{

	int u_len = 0;



	if (boundlen <= 0)

		return -ENAMETOOLONG;



	u_len = utf32_to_utf8(uni, out, boundlen);

	if (u_len < 0) {

		if (uni > UNICODE_MAX ||

		    (uni & SURROGATE_MASK) == SURROGATE_PAIR)

			return -EINVAL;

		return -ENAMETOOLONG;

	}

	return u_len;

}



#define ILLEGAL_CHAR_MARK	'_'

#define EXT_MARK		'.'

#define CRC_MARK		'#'
@@ -62,6 +43,50 @@ static int udf_uni2char_utf8(wchar_t uni, 
/* 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,
@@ -70,27 +95,29 @@ static int udf_name_conv_char(uint8_t *str_o, int str_o_max_len, 
			      int (*conv_f)(wchar_t, unsigned char *, int),

			      int translate)

{

	uint32_t c;

	unicode_t c;

	int illChar = 0;

	int len, gotch = 0;



	for (; (!gotch) && (*str_i_idx < str_i_max_len); *str_i_idx += u_ch) {

	while (!gotch && *str_i_idx < str_i_max_len) {

		if (*str_o_idx >= str_o_max_len) {

			*needsCRC = 1;

			return gotch;

		}



		/* Expand OSTA compressed Unicode to Unicode */

		c = str_i[*str_i_idx];

		if (u_ch > 1)

			c = (c << 8) | str_i[*str_i_idx + 1];



		if (translate && (c == '/' || c == 0))

		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;

		else if (illChar)

			if (!translate)

				gotch = 1;

		} else if (illChar)

			break;

		else

			gotch = 1;

		*str_i_idx += len;

	}

	if (illChar) {

		*needsCRC = 1;
@@ -98,7 +125,15 @@ static int udf_name_conv_char(uint8_t *str_o, int str_o_max_len, 
		gotch = 1;

	}

	if (gotch) {

		len = conv_f(c, &str_o[*str_o_idx], str_o_max_len - *str_o_idx);

		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;
@@ -106,7 +141,7 @@ static int udf_name_conv_char(uint8_t *str_o, int str_o_max_len, 
			*needsCRC = 1;

			gotch = 0;

		} else {

			str_o[(*str_o_idx)++] = '?';

			str_o[(*str_o_idx)++] = ILLEGAL_CHAR_MARK;

			*needsCRC = 1;

		}

	}
@@ -142,12 +177,10 @@ static int udf_name_from_CS0(struct super_block *sb, 
		return 0;

	}



	if (UDF_QUERY_FLAG(sb, UDF_FLAG_UTF8)) {

		conv_f = udf_uni2char_utf8;

	} else if (UDF_QUERY_FLAG(sb, UDF_FLAG_NLS_MAP)) {

	if (UDF_QUERY_FLAG(sb, UDF_FLAG_NLS_MAP))

		conv_f = UDF_SB(sb)->s_nls_map->uni2char;

	} else

		BUG();

	else

		conv_f = NULL;



	cmp_id = ocu[0];

	if (cmp_id != 8 && cmp_id != 16) {