RPi-LoRa-KISS-TNC/TCPServer.py

#!/usr/bin/python
# -*- coding: utf-8 -*-
from __future__ import print_function

RECV_BUFFER_LENGTH = 1024
import sys
from threading import Thread
import socket
from KissHelper import SerialParser
import KissHelper


def logf(message):
    print(message, file=sys.stderr)


class KissServer(Thread):
    '''TCP Server to be connected by the APRS digipeater'''

    txQueue = None

    # host and port as configured in aprx/aprx.conf.lora-aprs < interface > section
    def __init__(self, txQueue, host="127.0.0.1", port=10001):
        Thread.__init__(self)
        self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        self.socket.bind((host, port))
        self.socket.listen(1)
        self.data = str()
        self.txQueue = txQueue
        self.connection = None

    def run(self):
        parser = SerialParser(self.queue_frame)
        while True:
            self.connection = None
            self.connection, client_address = self.socket.accept()
            parser.reset()
            logf("KISS-Server: Connection from %s" % client_address[0])
            while True:
                data = self.connection.recv(RECV_BUFFER_LENGTH)
                if data:
                    parser.parse(data)
                else:
                    self.connection.close()
                    break

    def queue_frame(self, frame):
        print("KISS frame:", repr(frame))
        decoded_data = KissHelper.decode_kiss(frame)
        print("Decoded:", decoded_data)
        
        self.txQueue.put(decoded_data, block=False)

    def __del__(self):
        self.socket.shutdown()

    def send(self, data, metadata):
        try:
            encoded_data = KissHelper.encode_kiss(data)
        except Exception as e:
            print("KISS encoding went wrong (exception while parsing)")
            traceback.print_tb(e.__traceback__)
            encoded_data = None

        if encoded_data != None:
            print("To Server: " + repr(encoded_data))
            if self.connection:
                self.connection.sendall(encoded_data)
        else:
            print("KISS encoding went wrong")
        


if __name__ == '__main__':
    '''Test program'''
    import time
    from multiprocessing import Queue

    TCP_HOST = "0.0.0.0"
    TCP_PORT = 10001

    # frames to be sent go here
    KissQueue = Queue()

    server = KissServer(TCP_HOST, TCP_PORT, KissQueue)
    server.setDaemon(True)
    server.start()

    while True:
        server.send(
            "\xc0\x00\x82\xa0\xa4\xa6@@`\x9e\x8ar\xa8\x96\x90q\x03\xf0!4725.51N/00939.86E[322/002/A=001306 Batt=3.99V\xc0")
        data = KissQueue.get()
        print("Received KISS frame:" + repr(data))