NLS: improve UTF8 -> UTF16 string conversion routine

[pandora-kernel.git] / fs / nls / nls_base.c

diff --git a/fs/nls/nls_base.c b/fs/nls/nls_base.c
index 44a88a9..0eb059e 100644 (file)
--- a/fs/nls/nls_base.c
+++ b/fs/nls/nls_base.c
@@ -114,34 +114,57 @@ int utf32_to_utf8(unicode_t u, u8 *s, int maxlen)
 }
 EXPORT_SYMBOL(utf32_to_utf8);
 
 }
 EXPORT_SYMBOL(utf32_to_utf8);
 

-int utf8s_to_utf16s(const u8 *s, int len, wchar_t *pwcs)
+static inline void put_utf16(wchar_t *s, unsigned c, enum utf16_endian endian)
+{
+       switch (endian) {
+       default:
+               *s = (wchar_t) c;
+               break;
+       case UTF16_LITTLE_ENDIAN:
+               *s = __cpu_to_le16(c);
+               break;
+       case UTF16_BIG_ENDIAN:
+               *s = __cpu_to_be16(c);
+               break;
+       }
+}
+
+int utf8s_to_utf16s(const u8 *s, int len, enum utf16_endian endian,
+               wchar_t *pwcs, int maxlen)

 {
        u16 *op;
        int size;
        unicode_t u;
 
        op = pwcs;
 {
        u16 *op;
        int size;
        unicode_t u;
 
        op = pwcs;

-       while (*s && len > 0) {
+       while (len > 0 && maxlen > 0 && *s) {

                if (*s & 0x80) {
                        size = utf8_to_utf32(s, len, &u);
                        if (size < 0)
                                return -EINVAL;
                if (*s & 0x80) {
                        size = utf8_to_utf32(s, len, &u);
                        if (size < 0)
                                return -EINVAL;

+                       s += size;
+                       len -= size;

 
                        if (u >= PLANE_SIZE) {
 
                        if (u >= PLANE_SIZE) {

+                               if (maxlen < 2)
+                                       break;

                                u -= PLANE_SIZE;
                                u -= PLANE_SIZE;

-                               *op++ = (wchar_t) (SURROGATE_PAIR |
-                                               ((u >> 10) & SURROGATE_BITS));
-                               *op++ = (wchar_t) (SURROGATE_PAIR |
+                               put_utf16(op++, SURROGATE_PAIR |
+                                               ((u >> 10) & SURROGATE_BITS),
+                                               endian);
+                               put_utf16(op++, SURROGATE_PAIR |

                                                SURROGATE_LOW |
                                                SURROGATE_LOW |

-                                               (u & SURROGATE_BITS));
+                                               (u & SURROGATE_BITS),
+                                               endian);
+                               maxlen -= 2;

                        } else {
                        } else {

-                               *op++ = (wchar_t) u;
+                               put_utf16(op++, u, endian);
+                               maxlen--;

                        }
                        }

-                       s += size;
-                       len -= size;

                } else {
                } else {

-                       *op++ = *s++;
+                       put_utf16(op++, *s++, endian);

                        len--;
                        len--;

+                       maxlen--;

                }
        }
        return op - pwcs;
                }
        }
        return op - pwcs;