Changeset b06414f in mainline

Timestamp:

2017-05-19T14:04:36Z (7 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

e540bc87

Parents:

2628642

Message:

Use proper sizes for buffers holding conversions from/to UTF-16 LFN's

FAT uses UTF-16 for encoding long file names. HelenOS needs to convert
these strings into and from its native UTF-8 encoding. The size of the
UTF-8 buffer in bytes needs to be at least 4 times the number of
characters in a LFN.

Location:

uspace

Files:

• lib/c/generic/str.c (modified) (3 diffs)
• lib/c/include/str.h (modified) (1 diff)
• srv/fs/fat/fat_dentry.h (modified) (1 diff)
• srv/fs/fat/fat_directory.c (modified) (2 diffs)

uspace/lib/c/generic/str.c

@@ -951 +951 @@
 }
 
-int str_to_utf16(uint16_t *dest, size_t size, const char *src)
+/** Convert string to UTF16 string.
+ *
+ * Convert string @a src to utf16 string. The output is written to the buffer
+ * specified by @a dest and @a dlen. @a dlen must be non-zero and the string
+ * written will always be well-formed. Surrogate pairs also supported.
+ *
+ * @param dest  Destination buffer.
+ * @param dlen  Number of utf16 characters that fit in the destination buffer.
+ * @param src   Source string.
+ *
+ * @return EOK, if success, negative otherwise.
+ */
+int str_to_utf16(uint16_t *dest, size_t dlen, const char *src)
 {
         int rc = EOK;
@@ -958 +970 @@
         wchar_t c;
 
-        assert(size > 0);
+        assert(dlen > 0);
         
         while ((c = str_decode(src, &offset, STR_NO_LIMIT)) != 0) {
                 if (c > 0x10000) {
-                        if (idx + 2 >= size - 1) {
+                        if (idx + 2 >= dlen - 1) {
                                 rc = EOVERFLOW;
                                 break;
@@ -975 +987 @@
 
                 idx++;
-                if (idx >= size - 1) {
+                if (idx >= dlen - 1) {
                         rc = EOVERFLOW;
                         break;

uspace/lib/c/include/str.h

@@ -98 +98 @@
 extern wchar_t *str_to_awstr(const char *src);
 extern int utf16_to_str(char *dest, size_t size, const uint16_t *src);
-extern int str_to_utf16(uint16_t *dest, size_t size, const char *src);
+extern int str_to_utf16(uint16_t *dest, size_t dlen, const char *src);
 
 extern char *str_chr(const char *str, wchar_t ch);

uspace/srv/fs/fat/fat_dentry.h

@@ -83 +83 @@
 #define FAT_LFN_CHKSUM(d) ((d)->lfn.check_sum)
 
-#define FAT_LFN_NAME_SIZE   260
+#define FAT_LFN_NAME_LEN    260                           /* characters */
+#define FAT_LFN_NAME_SIZE   STR_BOUNDS(FAT_LFN_NAME_LEN)  /* bytes */
 #define FAT_LFN_MAX_COUNT   20
 #define FAT_LFN_PART1_SIZE  5

uspace/srv/fs/fat/fat_directory.c

@@ -155 +155 @@
 {
         fat_dentry_t *d = NULL;
-        uint16_t wname[FAT_LFN_NAME_SIZE];
+        uint16_t wname[FAT_LFN_NAME_LEN];
         size_t lfn_offset, lfn_size;
         bool long_entry = false;
@@ -293 +293 @@
                 int long_entry_count;
                 uint8_t checksum;
-                uint16_t wname[FAT_LFN_NAME_SIZE];
+                uint16_t wname[FAT_LFN_NAME_LEN];
                 size_t lfn_size, lfn_offset;
                 
-                rc = str_to_utf16(wname, FAT_LFN_NAME_SIZE, name);
+                rc = str_to_utf16(wname, FAT_LFN_NAME_LEN, name);
                 if (rc != EOK)
                         return rc;