Appendix A. C Snippet to Determine STUN Message Types

Given a 16-bit STUN message type value in host byte order in the msg_type parameter, the following are C macros for determining the STUN message type:

#define IS_REQUEST(msg_type)       (((msg_type) & 0x0110) == 0x0000)
#define IS_INDICATION(msg_type)    (((msg_type) & 0x0110) == 0x0010)
#define IS_SUCCESS_RESP(msg_type)  (((msg_type) & 0x0110) == 0x0100)
#define IS_ERR_RESP(msg_type)      (((msg_type) & 0x0110) == 0x0110)