Add crc16 verify type

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/crc16.h b/crc16.h
new file mode 100644
index 0000000..841378d
--- /dev/null
+++ b/crc16.h
@@ -0,0 +1,28 @@
+/*
+ *	crc16.h - CRC-16 routine
+ *
+ * Implements the standard CRC-16:
+ *   Width 16
+ *   Poly  0x8005 (x^16 + x^15 + x^2 + 1)
+ *   Init  0
+ *
+ * Copyright (c) 2005 Ben Gardner <bgardner@wabtec.com>
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2. See the file COPYING for more details.
+ */
+
+#ifndef __CRC16_H
+#define __CRC16_H
+
+extern unsigned short const crc16_table[256];
+
+extern unsigned short crc16(const unsigned char *buffer, unsigned int len);
+
+static inline unsigned short crc16_byte(unsigned short crc,
+					const unsigned char data)
+{
+	return (crc >> 8) ^ crc16_table[(crc ^ data) & 0xff];
+}
+
+#endif /* __CRC16_H */