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-rw-r--r--fs/udf/unicode.c398
1 files changed, 398 insertions, 0 deletions
diff --git a/fs/udf/unicode.c b/fs/udf/unicode.c
new file mode 100644
index 0000000000..32c7f3d27f
--- /dev/null
+++ b/fs/udf/unicode.c
@@ -0,0 +1,398 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 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
+ *
+ */
+
+#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_SB(sb)->s_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 > 0 && 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_SB(sb)->s_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);
+}
+