+------------------------------+
| Mikhail Rezazadeh |
| March 2017 |
| NASA SuperPressure Balloon |
| Project in New Zealand |
+------------------------------+
This is a TCP Server running on port 9999, intended to support
a fixed IP address on a local network (192.168.1.22). The purpose
is to response to ASCII text commands sent from the ground to the
balloon at 100,000 ft using NASA telemetry. Once the main payload
computer (192.168.1.20) receives the text command, it enters the
SYN SENT state and initiates a comnnection with the computer
running this program, which is in the LISTEN state.
The text is then sent to a dispatch table (src/server/handler.c)
where the computer reacts to it (for example by changing the temperature
of the thermocontroller, or by altering the image capture rate of the
infrared cameras).
For "Set" commands, a "*" is sent back to 192.168.1.20 upon success,
and "?" upon failure. For query commands, an ASCII string is returned
and the connection is immediately closed.
This server detaches threads as soon as the TCP "ESTABLISHED" state is
achieved, so it can theoretically make up to 16,384 connections (the
maximum number of threads for Ubuntu 14.04 LTS).
The server_daemon is a wrapper to avoid any unexpected