[PATCH 2/8] Add some UTF-16 functions for convenience

[Vladimir 'φ-coder/phcoder' Serbinenko <phcoder@xxxxxxxxx>]

Signed-off-by: Vladimir Serbinenko <phcoder@xxxxxxxxx>
---
 fs/nls/nls_base.c   |   63 +++++++++++++++++++++++++++++++++++++++++++++++++++
 fs/nls/nls_utf8.c   |    2 +-
 include/linux/nls.h |    6 +++++
 3 files changed, 70 insertions(+), 1 deletion(-)

diff --git a/fs/nls/nls_base.c b/fs/nls/nls_base.c
index 4f6d1ae..0c1ad5b 100644
--- a/fs/nls/nls_base.c
+++ b/fs/nls/nls_base.c
@@ -171,6 +171,32 @@ int utf8s_to_utf16s(const u8 *s, int inlen, enum utf16_endian endian,
 }
 EXPORT_SYMBOL(utf8s_to_utf16s);
 
+int unicode_to_utf16s(unicode_t u, enum utf16_endian endian,
+		      wchar_t *pwcs, int maxout)
+{
+	u16 *op = pwcs;
+
+	op = pwcs;
+
+	if (u >= PLANE_SIZE) {
+		if (maxout < 2)
+			return -1;
+		u -= PLANE_SIZE;
+		put_utf16(op++, SURROGATE_PAIR |
+			  ((u >> 10) & SURROGATE_BITS),
+			  endian);
+		put_utf16(op++, SURROGATE_PAIR |
+			  SURROGATE_LOW |
+			  (u & SURROGATE_BITS),
+			  endian);
+		return 2;
+	} else {
+		put_utf16(op++, u, endian);
+		return 1;
+	}
+}
+EXPORT_SYMBOL(unicode_to_utf16s);
+
 static inline unsigned long get_utf16(unsigned c, enum utf16_endian endian)
 {
 	switch (endian) {
@@ -232,6 +258,43 @@ int utf16s_to_utf8s(const wchar_t *pwcs, int inlen, enum utf16_endian endian,
 }
 EXPORT_SYMBOL(utf16s_to_utf8s);
 
+int utf16s_to_unicode(const wchar_t *pwcs, int inlen, enum utf16_endian endian,
+		      unicode_t *uni)
+{
+	unsigned long u, v;
+	const wchar_t *pwcs0 = pwcs;
+
+	while (inlen > 0) {
+		u = get_utf16(*pwcs, endian);
+		if (!u)
+			break;
+		pwcs++;
+		inlen--;
+		if ((u & SURROGATE_MASK) == SURROGATE_PAIR) {
+			if (u & SURROGATE_LOW) {
+				/* Ignore character and move on */
+				continue;
+			}
+			if (inlen <= 0)
+				break;
+			v = get_utf16(*pwcs, endian);
+			if ((v & SURROGATE_MASK) != SURROGATE_PAIR ||
+			    !(v & SURROGATE_LOW)) {
+				/* Ignore character and move on */
+				continue;
+			}
+			u = PLANE_SIZE + ((u & SURROGATE_BITS) << 10)
+				+ (v & SURROGATE_BITS);
+			pwcs++;
+			inlen--;
+		}
+		*uni = u;
+		return pwcs - pwcs0;
+	}
+	return 0;
+}
+EXPORT_SYMBOL(utf16s_to_unicode);
+
 int register_nls(struct nls_table * nls)
 {
 	struct nls_table ** tmp = &tables;
diff --git a/fs/nls/nls_utf8.c b/fs/nls/nls_utf8.c
index eb6392e..a3b3de0 100644
--- a/fs/nls/nls_utf8.c
+++ b/fs/nls/nls_utf8.c
@@ -37,7 +37,7 @@ static int char2uni(const unsigned char *rawstring, int boundlen,
 		*uni = 0x003f;	/* ? */
 		return -EINVAL;
 	}
-	*uni = (wchar_t) u;
+	*uni = u;
 	return n;
 }
 
diff --git a/include/linux/nls.h b/include/linux/nls.h
index c0292dd..7de1765 100644
--- a/include/linux/nls.h
+++ b/include/linux/nls.h
@@ -50,12 +50,18 @@ extern struct nls_table *load_nls(char *);
 extern void unload_nls(struct nls_table *);
 extern struct nls_table *load_nls_default(void);
 
+#define MAX_UTF16_PER_UNICODE 2
+
 extern int utf8_to_utf32(const u8 *s, int len, unicode_t *pu);
 extern int utf32_to_utf8(unicode_t u, u8 *s, int maxlen);
 extern int utf8s_to_utf16s(const u8 *s, int len,
 		enum utf16_endian endian, wchar_t *pwcs, int maxlen);
 extern int utf16s_to_utf8s(const wchar_t *pwcs, int len,
 		enum utf16_endian endian, u8 *s, int maxlen);
+int unicode_to_utf16s(unicode_t u, enum utf16_endian endian,
+		      wchar_t *pwcs, int maxout);
+int utf16s_to_unicode(const wchar_t *pwcs, int inlen, enum utf16_endian endian,
+		      unicode_t *uni);
 
 static inline unsigned char nls_tolower(struct nls_table *t, unsigned char c)
 {
-- 
1.7.10


-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko

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