dosfs: UTF-8 Support: UI, backwards compatibility

User interface and backwards compatibility for UTF-8 support in the FAT
file system.  Purpose of UTF-8 support is to permit file names and
directory names with characters from all kinds of languages (Czech,
Chinese, Arabian, Hebrew, Korean, ...).  This commit does not yet
support multibyte characters. It only contains the user interface and
the backwards compatibility.

1 files changed, 188 insertions, 0 deletions

diff --git a/cpukit/libfs/src/dosfs/msdos_conv_default.c b/cpukit/libfs/src/dosfs/msdos_conv_default.c
new file mode 100644
index 0000000000..baf83208f5
--- /dev/null
+++ b/cpukit/libfs/src/dosfs/msdos_conv_default.c
@@ -0,0 +1,188 @@
+/**
+ * @file
+ *
+ * @ingroup DOSFS
+ *
+ * @brief Default Converter
+ */
+
+/*
+ * Copyright (c) 2013 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Dornierstr. 4
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.com/license/LICENSE.
+ */
+
+#include <string.h>
+#include <errno.h>
+#include <ctype.h>
+#include <assert.h>
+#include <rtems/endian.h>
+#include <rtems/dosfs.h>
+#include "fat.h"
+#include "msdos.h"
+
+static int msdos_default_utf8_to_codepage(
+  rtems_dosfs_convert_control *super,
+  const uint8_t               *src,
+  const size_t                 src_size,
+  char                        *dst,
+  size_t                      *dst_size
+)
+{
+  int    eno = 0;
+  size_t bytes_to_copy = MIN( src_size, *dst_size );
+
+  (void) super;
+
+  *dst_size = bytes_to_copy;
+
+  memcpy( dst, src, bytes_to_copy );
+
+  return eno;
+}
+
+static int msdos_default_codepage_to_utf8(
+  rtems_dosfs_convert_control *super,
+  const char                  *src,
+  const size_t                 src_size,
+  uint8_t                     *dst,
+  size_t                      *dst_size
+)
+{
+  int    eno = 0;
+  size_t bytes_to_copy = MIN( src_size, *dst_size );
+
+  (void) super;
+
+  *dst_size = bytes_to_copy;
+
+  memcpy( dst, src, bytes_to_copy );
+
+  return eno;
+}
+
+static int msdos_default_utf8_to_utf16(
+  rtems_dosfs_convert_control *super,
+  const uint8_t               *src,
+  const size_t                 src_size,
+  uint16_t                    *dst,
+  size_t                      *dst_size
+)
+{
+  int    eno = 0;
+  size_t bytes_to_copy = MIN( src_size, *dst_size / 2);
+  size_t i;
+
+  (void) super;
+
+  *dst_size = 2 * bytes_to_copy;
+
+  for ( i = 0; eno == 0 && i < bytes_to_copy; ++i ) {
+    uint16_t utf16_native = src[i];
+
+    if ( utf16_native <= 127 ) {
+      dst[i] = CT_LE_W( utf16_native );
+    } else {
+      eno = EINVAL;
+    }
+  }
+
+  return eno;
+}
+
+static int msdos_default_utf16_to_utf8(
+  rtems_dosfs_convert_control *super,
+  const uint16_t              *src,
+  const size_t                 src_size,
+  uint8_t                     *dst,
+  size_t                      *dst_size
+)
+{
+  int    eno = 0;
+  size_t bytes_to_copy = MIN( src_size / 2, *dst_size );
+  size_t i;
+
+  (void) super;
+
+  *dst_size = bytes_to_copy;
+
+  for ( i = 0; eno == 0 && i < bytes_to_copy; ++i ) {
+    uint16_t utf16_le = src[i];
+    uint16_t utf16_native  = CF_LE_W( utf16_le );
+
+    if ( utf16_native <= 127 ) {
+      dst[i] = (uint8_t) utf16_native;
+    } else {
+      eno = EINVAL;
+    }
+  }
+
+  return eno;
+}
+
+static int msdos_default_normalize_and_fold(
+  rtems_dosfs_convert_control *super,
+  const uint8_t               *src,
+  const size_t                 src_size,
+  uint8_t                     *dst,
+  size_t                      *dst_size
+)
+{
+  int    eno = 0;
+  size_t bytes_to_copy = MIN( src_size, *dst_size );
+  size_t i;
+
+  (void) super;
+
+  *dst_size = bytes_to_copy;
+
+  for ( i = 0; i < bytes_to_copy; ++i ) {
+    dst[i] = tolower( src[i] );
+  }
+
+  return eno;
+}
+
+static void msdos_default_destroy(
+  rtems_dosfs_convert_control *super
+)
+{
+  free( super );
+}
+
+static const rtems_dosfs_convert_handler msdos_default_convert_handler = {
+  .utf8_to_codepage = msdos_default_utf8_to_codepage,
+  .codepage_to_utf8 = msdos_default_codepage_to_utf8,
+  .utf8_to_utf16 = msdos_default_utf8_to_utf16,
+  .utf16_to_utf8 = msdos_default_utf16_to_utf8,
+  .utf8_normalize_and_fold = msdos_default_normalize_and_fold,
+  .destroy = msdos_default_destroy
+};
+
+typedef struct {
+  rtems_dosfs_convert_control super;
+  uint8_t buffer[MSDOS_NAME_MAX_LFN_BYTES];
+} msdos_default_convert_control;
+
+rtems_dosfs_convert_control *rtems_dosfs_create_default_converter(void)
+{
+  msdos_default_convert_control *self = malloc( sizeof( *self ) );
+
+  if ( self != NULL ) {
+    rtems_dosfs_convert_control *super = &self->super;
+
+    super->handler = &msdos_default_convert_handler;
+    super->buffer.data = &self->buffer;
+    super->buffer.size = sizeof( self->buffer );
+  }
+
+  return &self->super;
+}