syntax = "proto2"; enum MessageStatus { FAIL = 0; OK = 1; }; message MessageInfo { required fixed32 msg_id = 1; optional fixed32 interface_id = 2; } message MessageResponseInfo { required fixed64 interface_id = 1; required fixed32 seq = 2; required fixed32 msg_id = 3; } message MessageHeader { required MessageInfo info = 1; optional MessageResponseInfo response_info = 2; optional MessageResponse response = 3; } message MessageResponse { required MessageStatus status = 1; required fixed32 seq = 2; }