dosfs: UTF-8 Support: Multibyte conversions

Add optional conversion methods for multibyte strings. With these
conversions which make use of iconv and utf8proc it becomes possible to
use strings from any language (Czech, Chinese, Arabian, Hebrew, Corean,
...) for file names and directory names.

NOTE: Iconv support must be activated during the build of the tool chain
for these conversion methods (options --enable-newlib-iconv
--enable-newlib-iconv-encodings=[ENCODINGS_YOU_WANT]).  Alternatively
you can provide your own conversion methods.

1 files changed, 15 insertions, 9 deletions

diff --git a/cpukit/libfs/src/dosfs/msdos_misc.c b/cpukit/libfs/src/dosfs/msdos_misc.c
index 56b58c85f7..959768c286 100644
--- a/cpukit/libfs/src/dosfs/msdos_misc.c
+++ b/cpukit/libfs/src/dosfs/msdos_misc.c
@@ -42,6 +42,13 @@
 
 #include <stdio.h>
 
+#define MSDOS_LFN_ENTRY_SIZE \
+  (MSDOS_LFN_LEN_PER_ENTRY * MSDOS_NAME_LFN_BYTES_PER_CHAR)
+
+#define MSDOS_LFN_ENTRY_SIZE_UTF8 \
+  ((MSDOS_LFN_LEN_PER_ENTRY + 1 ) * MSDOS_NAME_LFN_BYTES_PER_CHAR \
+    * MSDOS_NAME_MAX_UTF8_BYTES_PER_CHAR)
+
 /*
  * External strings. Saves space this way.
  */
@@ -1019,7 +1026,7 @@ msdos_get_utf16_string_from_long_entry (
 {
     ssize_t chars_in_entry;
 
-    if (buf_size >= MSDOS_LFN_LEN_PER_ENTRY * MSDOS_NAME_LFN_BYTES_PER_CHAR) {
+    if (buf_size >= MSDOS_LFN_ENTRY_SIZE) {
         memcpy (&entry_string_buf[0],  &entry[1],  10 );
         memcpy (&entry_string_buf[5],  &entry[14], 12 );
         memcpy (&entry_string_buf[11], &entry[28],  4 );
@@ -1195,7 +1202,7 @@ msdos_compare_entry_against_filename (
 {
   ssize_t      size_remaining = filename_size_remaining;
   int          eno            = 0;
-  uint8_t      entry_normalized[( MSDOS_LFN_LEN_PER_ENTRY + 1 ) * MSDOS_NAME_LFN_BYTES_PER_CHAR * MSDOS_NAME_MAX_UTF8_BYTES_PER_CHAR];
+  uint8_t      entry_normalized[MSDOS_LFN_ENTRY_SIZE_UTF8];
   size_t       bytes_in_entry_normalized = sizeof ( entry_normalized );
 
   eno = (*converter->handler->utf8_normalize_and_fold) (
@@ -1263,7 +1270,7 @@ msdos_find_file_in_directory (
     bool              empty_space_found = false;
     uint32_t          entries_per_block = bts2rd / MSDOS_DIRECTORY_ENTRY_STRUCT_SIZE;
     int               lfn_entry         = 0;
-    uint8_t           entry_utf8_normalized[(MSDOS_LFN_LEN_PER_ENTRY + 1 ) * MSDOS_NAME_LFN_BYTES_PER_CHAR * MSDOS_NAME_MAX_UTF8_BYTES_PER_CHAR/*MSDOS_ENTRY_LFN_UTF8_BYTES*/];
+    uint8_t           entry_utf8_normalized[MSDOS_LFN_ENTRY_SIZE_UTF8];
     size_t            bytes_in_entry;
     bool              filename_matched  = false;
     ssize_t           filename_size_remaining = name_len_for_compare;
@@ -1800,7 +1807,7 @@ msdos_add_file (
             *MSDOS_DIR_LFN_CHECKSUM(entry) = lfn_checksum;
 
             p = entry + 1;
-            n = name_converted + (fat_entries - lfn_entry) * MSDOS_LFN_LEN_PER_ENTRY * MSDOS_NAME_LFN_BYTES_PER_CHAR;
+            n = name_converted + (fat_entries - lfn_entry) * MSDOS_LFN_ENTRY_SIZE;
 
 #if MSDOS_FIND_PRINT
             printf ("MSFS:[11] ");
@@ -1919,8 +1926,8 @@ msdos_find_name_in_fat_file (
                 buffer,
                 buffer_size);
             if (name_len_for_save > 0) {
-                fat_entries = (name_len_for_save -1
-                               + (MSDOS_LFN_LEN_PER_ENTRY * MSDOS_NAME_LFN_BYTES_PER_CHAR)) / (MSDOS_LFN_LEN_PER_ENTRY * MSDOS_NAME_LFN_BYTES_PER_CHAR);
+                fat_entries = (name_len_for_save + MSDOS_LFN_ENTRY_SIZE - 1)
+                    / MSDOS_LFN_ENTRY_SIZE;
                 name_len_for_compare = msdos_filename_utf8_to_long_name_for_compare (
                   converter,
                   name_utf8,
@@ -1984,9 +1991,8 @@ msdos_find_name_in_fat_file (
                   buffer,
                   buffer_size);
               if (name_len_for_save > 0) {
-                fat_entries = (name_len_for_save -1
-                               + (MSDOS_LFN_LEN_PER_ENTRY * MSDOS_NAME_LFN_BYTES_PER_CHAR)) / (MSDOS_LFN_LEN_PER_ENTRY * MSDOS_NAME_LFN_BYTES_PER_CHAR);
-
+                  fat_entries = (name_len_for_save + MSDOS_LFN_ENTRY_SIZE - 1)
+                    / MSDOS_LFN_ENTRY_SIZE;
               }
               else
                   retval = -1;