udf: Merge linux specific translation into CS0 conversion function
authorAndrew Gabbasov <andrew_gabbasov@mentor.com>
Fri, 15 Jan 2016 08:44:23 +0000 (02:44 -0600)
committerJan Kara <jack@suse.cz>
Tue, 9 Feb 2016 12:05:23 +0000 (13:05 +0100)
Current implementation of udf_translate_to_linux function does not
support multi-bytes characters at all: it counts bytes while calculating
extension length, when inserting CRC inside the name it doesn't
take into account inter-character boundaries and can break into
the middle of the character.

The most efficient way to properly support multi-bytes characters is
merging of translation operations directly into conversion function.
This can help to avoid extra passes along the string or parsing
the multi-bytes character back into unicode to find out it's length.

Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Signed-off-by: Jan Kara <jack@suse.cz>
fs/udf/unicode.c

index dc5990f..3ff42f4 100644 (file)
@@ -28,9 +28,6 @@
 
 #include "udf_sb.h"
 
-static int udf_translate_to_linux(uint8_t *, int, const uint8_t *, int,
-                                 const uint8_t *, int);
-
 static int udf_uni2char_utf8(wchar_t uni,
                             unsigned char *out,
                             int boundlen)
@@ -114,13 +111,83 @@ static int udf_char2uni_utf8(const unsigned char *in,
        return u_len;
 }
 
+#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 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)
+{
+       uint32_t c;
+       int illChar = 0;
+       int len, gotch = 0;
+
+       for (; (!gotch) && (*str_i_idx < str_i_max_len); *str_i_idx += u_ch) {
+               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))
+                       illChar = 1;
+               else if (illChar)
+                       break;
+               else
+                       gotch = 1;
+       }
+       if (illChar) {
+               *needsCRC = 1;
+               c = ILLEGAL_CHAR_MARK;
+               gotch = 1;
+       }
+       if (gotch) {
+               len = conv_f(c, &str_o[*str_o_idx], str_o_max_len - *str_o_idx);
+               /* Valid character? */
+               if (len >= 0)
+                       *str_o_idx += len;
+               else if (len == -ENAMETOOLONG) {
+                       *needsCRC = 1;
+                       gotch = 0;
+               } else {
+                       str_o[(*str_o_idx)++] = '?';
+                       *needsCRC = 1;
+               }
+       }
+       return gotch;
+}
+
 static int udf_name_from_CS0(uint8_t *str_o, int str_max_len,
                             const uint8_t *ocu, int ocu_len,
-                            int (*conv_f)(wchar_t, unsigned char *, int))
+                            int (*conv_f)(wchar_t, unsigned char *, int),
+                            int translate)
 {
+       uint32_t c;
        uint8_t cmp_id;
-       int i, len;
-       int str_o_len = 0;
+       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];
 
        if (str_max_len <= 0)
                return 0;
@@ -133,24 +200,88 @@ static int udf_name_from_CS0(uint8_t *str_o, int str_max_len,
        cmp_id = ocu[0];
        if (cmp_id != 8 && cmp_id != 16) {
                memset(str_o, 0, str_max_len);
-               pr_err("unknown compression code (%d) stri=%s\n", cmp_id, ocu);
+               pr_err("unknown compression code (%d)\n", cmp_id);
                return -EINVAL;
        }
+       u_ch = cmp_id >> 3;
 
-       for (i = 1; (i < ocu_len) && (str_o_len < str_max_len);) {
-               /* Expand OSTA compressed Unicode to Unicode */
-               uint32_t c = ocu[i++];
-               if (cmp_id == 16)
-                       c = (c << 8) | ocu[i++];
+       ocu++;
+       ocu_len--;
 
-               len = conv_f(c, &str_o[str_o_len], str_max_len - str_o_len);
-               /* Valid character? */
-               if (len >= 0)
-                       str_o_len += len;
-               else if (len == -ENAMETOOLONG)
+       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;
-               else
-                       str_o[str_o_len++] = '?';
+               }
+
+               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;
@@ -207,13 +338,12 @@ try_again:
 int udf_CS0toUTF8(uint8_t *utf_o, int o_len, const uint8_t *ocu_i, int i_len)
 {
        return udf_name_from_CS0(utf_o, o_len, ocu_i, i_len,
-                                udf_uni2char_utf8);
+                                udf_uni2char_utf8, 0);
 }
 
 int udf_get_filename(struct super_block *sb, const uint8_t *sname, int slen,
                     uint8_t *dname, int dlen)
 {
-       uint8_t *filename;
        int (*conv_f)(wchar_t, unsigned char *, int);
        int ret;
 
@@ -223,10 +353,6 @@ int udf_get_filename(struct super_block *sb, const uint8_t *sname, int slen,
        if (dlen <= 0)
                return 0;
 
-       filename = kmalloc(dlen, GFP_NOFS);
-       if (!filename)
-               return -ENOMEM;
-
        if (UDF_QUERY_FLAG(sb, UDF_FLAG_UTF8)) {
                conv_f = udf_uni2char_utf8;
        } else if (UDF_QUERY_FLAG(sb, UDF_FLAG_NLS_MAP)) {
@@ -234,19 +360,10 @@ int udf_get_filename(struct super_block *sb, const uint8_t *sname, int slen,
        } else
                BUG();
 
-       ret = udf_name_from_CS0(filename, dlen, sname, slen, conv_f);
-       if (ret < 0) {
-               udf_debug("Failed in udf_get_filename: sname = %s\n", sname);
-               goto out2;
-       }
-
-       ret = udf_translate_to_linux(dname, dlen, filename, dlen,
-                                    sname + 1, slen - 1);
+       ret = udf_name_from_CS0(dname, dlen, sname, slen, conv_f, 1);
        /* Zero length filename isn't valid... */
        if (ret == 0)
                ret = -EINVAL;
-out2:
-       kfree(filename);
        return ret;
 }
 
@@ -265,96 +382,3 @@ int udf_put_filename(struct super_block *sb, const uint8_t *sname, int slen,
        return udf_name_to_CS0(dname, dlen, sname, slen, conv_f);
 }
 
-#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 int udf_translate_to_linux(uint8_t *newName, int newLen,
-                                 const uint8_t *udfName, int udfLen,
-                                 const uint8_t *fidName, int fidNameLen)
-{
-       int index, newIndex = 0, needsCRC = 0;
-       int extIndex = 0, newExtIndex = 0, hasExt = 0;
-       unsigned short valueCRC;
-       uint8_t curr;
-
-       if (udfName[0] == '.' &&
-           (udfLen == 1 || (udfLen == 2 && udfName[1] == '.'))) {
-               needsCRC = 1;
-               newIndex = udfLen;
-               memcpy(newName, udfName, udfLen);
-       } else {
-               for (index = 0; index < udfLen; index++) {
-                       curr = udfName[index];
-                       if (curr == '/' || curr == 0) {
-                               needsCRC = 1;
-                               curr = ILLEGAL_CHAR_MARK;
-                               while (index + 1 < udfLen &&
-                                               (udfName[index + 1] == '/' ||
-                                                udfName[index + 1] == 0))
-                                       index++;
-                       }
-                       if (curr == EXT_MARK &&
-                                       (udfLen - index - 1) <= EXT_SIZE) {
-                               if (udfLen == index + 1)
-                                       hasExt = 0;
-                               else {
-                                       hasExt = 1;
-                                       extIndex = index;
-                                       newExtIndex = newIndex;
-                               }
-                       }
-                       if (newIndex < newLen)
-                               newName[newIndex++] = curr;
-                       else
-                               needsCRC = 1;
-               }
-       }
-       if (needsCRC) {
-               uint8_t ext[EXT_SIZE];
-               int localExtIndex = 0;
-
-               if (hasExt) {
-                       int maxFilenameLen;
-                       for (index = 0;
-                            index < EXT_SIZE && extIndex + index + 1 < udfLen;
-                            index++) {
-                               curr = udfName[extIndex + index + 1];
-
-                               if (curr == '/' || curr == 0) {
-                                       needsCRC = 1;
-                                       curr = ILLEGAL_CHAR_MARK;
-                                       while (extIndex + index + 2 < udfLen &&
-                                             (index + 1 < EXT_SIZE &&
-                                               (udfName[extIndex + index + 2] == '/' ||
-                                                udfName[extIndex + index + 2] == 0)))
-                                               index++;
-                               }
-                               ext[localExtIndex++] = curr;
-                       }
-                       maxFilenameLen = newLen - CRC_LEN - localExtIndex;
-                       if (newIndex > maxFilenameLen)
-                               newIndex = maxFilenameLen;
-                       else
-                               newIndex = newExtIndex;
-               } else if (newIndex > newLen - CRC_LEN)
-                       newIndex = newLen - CRC_LEN;
-               newName[newIndex++] = CRC_MARK;
-               valueCRC = crc_itu_t(0, fidName, fidNameLen);
-               newName[newIndex++] = hex_asc_upper_hi(valueCRC >> 8);
-               newName[newIndex++] = hex_asc_upper_lo(valueCRC >> 8);
-               newName[newIndex++] = hex_asc_upper_hi(valueCRC);
-               newName[newIndex++] = hex_asc_upper_lo(valueCRC);
-
-               if (hasExt) {
-                       newName[newIndex++] = EXT_MARK;
-                       for (index = 0; index < localExtIndex; index++)
-                               newName[newIndex++] = ext[index];
-               }
-       }
-
-       return newIndex;
-}