CIFS: Separate SMB2 header structure

In order to support compounding and encryption we need to separate
RFC1001 length field and SMB2 header structure because the protocol
treats them differently. This change will allow to simplify parsing
of such complex SMB2 packets further.

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>

fs/cifs/smb2glob.h

@@ -61,4 +61,9 @@
 /* Maximum buffer size value we can send with 1 credit */
 #define SMB2_MAX_BUFFER_SIZE 65536
 
+static inline struct smb2_sync_hdr *get_sync_hdr(void *buf)
+{
+	return &(((struct smb2_hdr *)buf)->sync_hdr);
+}
+
 #endif	/* _SMB2_GLOB_H */