Notes

# !/usr/bin/env python
# File name: vlctun_1.0.3.py # Version: 1.0.3 # Author: Mehmet Ayaz # Date created: 13/04/2017 # Date last modified: 28/05/2017
# Begin code
from pytun import TunTapDevice, IFF_TUN, IFF_NO_PI from base64 import b64decode, b64encode import sys import select import signal import serial
class Tun(object): # Tun object is created # --PC1--------------------<><>--------------------PC2- # kernel_1 -> tun -> serial -> serial -> tun -> kernel_2 # <- <- <- <- < def __init__(self, side): self.side = int(side) if self.side not in [1, 2]: print("Side must be 1 or 2") raise Exception("Invalid Side") self.port = serial.Serial(port='/dev/ttyUSB0', baudrate=9600, bytesize=serial.EIGHTBITS, stopbits=serial.STOPBITS_ONE, timeout=None) # Opens serial port self.tun = TunTapDevice(flags=IFF_TUN | IFF_NO_PI, name='vlctun%d' % self.side, dev='/dev/net/tun') # Creates TUN device self.tun.addr = '10.0.8.%d' % self.side self.tun.netmask = '255.255.255.0' self.tun.mtu = 1500 # Maximum Transmission Unit self.epoll = select.epoll() self.epoll.register(self.tun.fileno(), select.EPOLLIN) self.tun.up() self.running = False self.outdata = None # Data from read TUN self.write_buf = None # Data to write serial
27
self.read_buf = None # Data from read serial self.indata = None # Data to write TUN self.olddata = None
def read_tun(self): # Reads a packet from TUN device events = self.epoll.poll(0) if events: self.outdata = self.tun.read(self.tun.mtu) self.debug(self.outdata, 'from TUN: ') return True else: return False
def write_serial(self): # Encodes and sends a packet self.write_buf = str(b64encode(self.outdata), 'utf-8') + 'n' self.debug(self.write_buf, 'to serial: ') self.port.write(self.write_buf.encode('utf-8'))
def read_serial(self): # Reads and decodes incoming packet if not self.port.in_waiting: return False self.read_buf = self.port.readline().decode('utf-8') self.debug(self.read_buf, 'from serial: ') self.indata = b64decode(bytes(self.read_buf.rstrip(), 'utf-8')) self.write_tun()
def write_tun(self): # Writes incoming packet to TUN device if len(self.indata) > 0: if self.indata != self.olddata: self.debug(self.indata, 'to TUN: ') try: self.tun.write(self.indata) self.olddata = self.indata return True except: print('Failed to write TUN!') return False
def run(self): self.running = True while self.running: if not self.port.writable(): self.running = False if self.read_tun(): self.write_serial() self.read_serial()
@staticmethod def debug(data, text): print('Data ' + text, data)
28
print('Size: ', len(data), end=' ') print('Type: ', type(data)) print('n' + '-' * 50 + 'n')
def main(): if len(sys.argv) < 2 or sys.argv[1] not in ['1', '2']: print("Must specify side 1 or 2 of tunnel") sys.exit(0) tun = Tun(sys.argv[1])
def signal_handler(signal, frame): print('Shutting down') tun.running = False signal.signal(signal.SIGINT, signal_handler) signal.signal(signal.SIGTERM, signal_handler)
tun.run() sys.exit(0)
if __name__ == "__main__": main()