variables to run gptp ipc thread
- ipcthread -> thread variable
- ipcstop -> used to stop ipc thread.
- pname -> ipc socket node suffix
- query_interval -> issue IPC requests in this interval time(msec). if 0, no request.
- printdata -> if true, print the IPC data on cosole
- ipcfd -> socket descriptor for IPC. if 0, open new socket.
- cb -> callback function
- cbdata -> callback data
- udpport -> udp port number to use UDP for IPC. if 0, use domain socket.
- udpaddr -> udp address to use local UDP for IPC. if NULL, use 127.0.0.1