HBLink/hblink.py
Cort Buffington cce709832b SECURITY! and cleanups
comprehensive checking to see packets are received from the IP and port
that match the Radio ID, or master. HB Protocol has some weaknesses
without this. More cleanup and documentation.
2016-07-26 20:51:04 -05:00

408 lines
21 KiB
Python
Executable File

#!/usr/bin/env python
#
# This work is licensed under the Creative Attribution-NonCommercial-ShareAlike
# 3.0 Unported License.To view a copy of this license, visit
# http://creativecommons.org/licenses/by-nc-sa/3.0/ or send a letter to
# Creative Commons, 444 Castro Street, Suite 900, Mountain View,
# California, 94041, USA.
from __future__ import print_function
# Python modules we need
import argparse
import sys
import os
import signal
# Specifig functions from modules we need
from binascii import b2a_hex as h
from binascii import a2b_hex as a
from socket import gethostbyname
from random import randint
from hashlib import sha256
from time import time
# Debugging functions
from pprint import pprint
# Twisted is pretty important, so I keep it separate
from twisted.internet.protocol import DatagramProtocol
from twisted.internet import reactor
from twisted.internet import task
# Other files we pull from -- this is mostly for readability and segmentation
import hb_log
import hb_config
# Does anybody read this stuff? There's a PEP somewhere that says I should do this.
__author__ = 'Cortney T. Buffington, N0MJS'
__copyright__ = 'Copyright (c) 2013 - 2016 Cortney T. Buffington, N0MJS and the K0USY Group'
__credits__ = 'Colin Durbridge, G4EML, Steve Zingman, N4IRS; Mike Zingman, N4IRR; Jonathan Naylor, G4KLX; Hans Barthen, DL5DI; Torsten Shultze, DG1HT'
__license__ = 'Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported'
__maintainer__ = 'Cort Buffington, N0MJS'
__email__ = 'n0mjs@me.com'
__status__ = 'pre-alpha'
# Change the current directory to the location of the application
os.chdir(os.path.dirname(os.path.realpath(sys.argv[0])))
# CLI argument parser - handles picking up the config file from the command line, and sending a "help" message
parser = argparse.ArgumentParser()
parser.add_argument('-c', '--config', action='store', dest='CONFIG_FILE', help='/full/path/to/config.file (usually hblink.cfg)')
parser.add_argument('-l', '--logging', action='store', dest='LOG_LEVEL', help='Override config file logging level.')
cli_args = parser.parse_args()
# Ensure we have a path for the config file, if one wasn't specified, then use the execution directory
if not cli_args.CONFIG_FILE:
cli_args.CONFIG_FILE = os.path.dirname(os.path.abspath(__file__))+'/hblink.cfg'
# Call the external routine to build the configuration dictionary
CONFIG = hb_config.build_config(cli_args.CONFIG_FILE)
# Call the external routing to start the system logger
if cli_args.LOG_LEVEL:
CONFIG['LOGGER']['LOG_LEVEL'] = cli_args.LOG_LEVEL
logger = hb_log.config_logging(CONFIG['LOGGER'])
logger.debug('Logging system started, anything from here on gets logged')
# Shut ourselves down gracefully by disconnecting from the masters and clients.
def handler(_signal, _frame):
logger.info('*** HBLINK IS TERMINATING WITH SIGNAL %s ***', str(_signal))
for client in clients:
this_client = clients[client]
this_client.send_packet('RPTCL'+CONFIG['CLIENTS'][client]['RADIO_ID'])
logger.info('(%s) De-Registering From the Master', client)
for master in masters:
this_master = masters[master]
for client in CONFIG['MASTERS'][master]['CLIENTS']:
this_master.send_packet(client, 'MSTCL'+client)
print(CONFIG['MASTERS'][master]['CLIENTS'][client]['RADIO_ID'])
logger.info('(%s) Sending De-Registration to Client: %s', master, CONFIG['MASTERS'][master]['CLIENTS'][client]['RADIO_ID'])
reactor.stop()
# Set signal handers so that we can gracefully exit if need be
for sig in [signal.SIGTERM, signal.SIGINT, signal.SIGQUIT]:
signal.signal(sig, handler)
#************************************************
# UTILITY FUNCTIONS
#************************************************
# Create a 4 byte hex string from an integer
def hex_str_4(_int_id):
try:
return hex(_int_id)[2:].rjust(8,'0').decode('hex')
except TypeError:
logger.error('hex_str_4: invalid integer length')
#************************************************
# HB MASTER CLASS
#************************************************
class HBMASTER(DatagramProtocol):
def __init__(self, *args, **kwargs):
if len(args) == 1:
# Define a few shortcuts to make the rest of the class more readable
self._master = args[0]
self._config = CONFIG['MASTERS'][self._master]
self._clients = CONFIG['MASTERS'][self._master]['CLIENTS']
else:
# If we didn't get called correctly, log it and quit.
logger.error('(%s) HBMASTER was not called with an argument. Terminating', self._master)
sys.exit()
def startProtocol(self):
# Set up periodic loop for tracking pings from clients. Run every 'PING_TIME' seconds
self._master_maintenance = task.LoopingCall(self.master_maintenance_loop)
self._master_maintenance_loop = self._master_maintenance.start(CONFIG['GLOBAL']['PING_TIME'])
def master_maintenance_loop(self):
logger.debug('(%s) Master maintenance loop started', self._master)
for client in self._clients.keys():
_this_client = self._clients[client]
# Check to see if any of the clients have been quiet (no ping) longer than allowed
if _this_client['LAST_PING']+CONFIG['GLOBAL']['PING_TIME']*CONFIG['GLOBAL']['MAX_MISSED'] < time():
logger.info('(%s) Client %s has timed out', self._master, _this_client['RADIO_ID'])
# Remove any timed out clients from the configuration
del CONFIG['MASTERS'][self._master]['CLIENTS'][client]
def send_packet(self, _client, _packet):
self.transport.write(_packet, (self._clients[_client]['IP'], self._clients[_client]['PORT']))
# KEEP THE FOLLOWING COMMENTED OUT UNLESS YOU'RE DEBUGGING DEEPLY!!!!
#logger.debug('(%s) TX Packet to %s on port %s: %s', self._client, self._config['MASTER_IP'], self._config['MASTER_PORT'], h(_packet))
def dmrd_received(self, _radio_id, _data):
pass
def datagramReceived(self, _data, (_host, _port)):
# Extract the command, which is various length, but only 4 significant characters
_command = _data[:4]
if _command == 'DMRD': # DMRData -- encapsulated DMR data frame
_radio_id = _data[4:8]
if _radio_id in self._clients \
and self._clients[_radio_id]['IP'] == _host \
and self._clients[_radio_id]['PORT'] == _port:
logger.debug('(%s) DMRD Received', self._master)
self.dmrd_received(_radio_id, _data)
else:
logger.warning('(%s) DMRD packet recieved from an invalid client')
elif _command == 'RPTL': # RPTLogin -- a repeater wants to login
_radio_id = _data[4:8]
if _radio_id: # Future check here for valid Radio ID
self._clients.update({_radio_id: { # Build the configuration data strcuture for the client
'CONNECTION': 'RPTL-RECEIVED',
'PINGS_RECEIVED': 0,
'LAST_PING': time(),
'IP': _host,
'PORT': _port,
'SALT': randint(0,0xFFFFFFFF),
'RADIO_ID': str(int(h(_radio_id), 16)),
'CALLSIGN': '',
'RX_FREQ': '',
'TX_FREQ': '',
'TX_POWER': '',
'COLORCODE': '',
'LATITUDE': '',
'LONGITUDE': '',
'HEIGHT': '',
'LOCATION': '',
'DESCRIPTION': '',
'SLOTS': '',
'URL': '',
'SOFTWARE_ID': '',
'PACKAGE_ID': '',
}})
logger.info('(%s) Repeater Logging in with Radio ID: %s', self._master, h(_radio_id))
_salt_str = hex_str_4(self._clients[_radio_id]['SALT'])
self.send_packet(_radio_id, 'RPTACK'+_salt_str)
self._clients[_radio_id]['CONNECTION'] = 'CHALLENGE_SENT'
logger.info('(%s) Sent Challenge Response to %s for login: %s', self._master, h(_radio_id), self._clients[_radio_id]['SALT'])
else:
self.transport.write('MSTNAK'+_radio_id, (_host, _port))
logger.warning('(%s) Invalid Login from Radio ID: %s', self._master, h(_radio_id))
elif _command == 'RPTK': # Repeater has answered our login challenge
_radio_id = _data[4:8]
if _radio_id in self._clients \
and self._clients[_radio_id]['CONNECTION'] == 'CHALLENGE_SENT' \
and self._clients[_radio_id]['IP'] == _host \
and self._clients[_radio_id]['PORT'] == _port:
_this_client = self._clients[_radio_id]
_this_client['LAST_PING'] = time()
_sent_hash = _data[8:]
_salt_str = hex_str_4(_this_client['SALT'])
_calc_hash = a(sha256(_salt_str+self._config['PASSPHRASE']).hexdigest())
if _sent_hash == _calc_hash:
_this_client['CONNECTION'] = 'WAITING_CONFIG'
self.send_packet(_radio_id, 'RPTACK'+_radio_id)
logger.info('(%s) Client %s has completed the login exchange successfully', self._master, _this_client['RADIO_ID'])
else:
logger.info('(%s) Client %s has FAILED the login exchange successfully', self._master, _this_client['RADIO_ID'])
self.transport.write('MSTNAK'+_radio_id, (_host, _port))
del self._clients[_radio_id]
else:
self.transport.write('MSTNAK'+_radio_id, (_host, _port))
logger.warning('(%s) Login challenge from Radio ID that has not logged in: %s', self._master, h(_radio_id))
elif _command == 'RPTC': # Repeater is sending it's configuraiton information
_radio_id = _data[4:8]
if _radio_id in self._clients \
and self._clients[_radio_id]['CONNECTION'] == 'WAITING_CONFIG' \
and self._clients[_radio_id]['IP'] == _host \
and self._clients[_radio_id]['PORT'] == _port:
_this_client = self._clients[_radio_id]
_this_client['CONNECTION'] = 'YES'
_this_client['LAST_PING'] = time()
_this_client['CALLSIGN'] = _data[8:16]
_this_client['RX_FREQ'] = _data[16:25]
_this_client['TX_FREQ'] = _data[25:34]
_this_client['TX_POWER'] = _data[34:36]
_this_client['COLORCODE'] = _data[36:38]
_this_client['LATITUDE'] = _data[38:47]
_this_client['LONGITUDE'] = _data[47:57]
_this_client['HEIGHT'] = _data[57:60]
_this_client['LOCATION'] = _data[60:80]
_this_client['DESCRIPTION'] = _data[80:99]
_this_client['SLOTS'] = _data[99:100]
_this_client['URL'] = _data[100:224]
_this_client['SOFTWARE_ID'] = _data[224:264]
_this_client['PACKAGE_ID'] = _data[264:304]
self.send_packet(_radio_id, 'RPTACK'+_radio_id)
logger.info('(%s) Client %s has sent repeater configuration', self._master, _this_client['RADIO_ID'])
else:
self.transport.write('MSTNAK'+_radio_id, (_host, _port))
logger.warning('(%s) Client info from Radio ID that has not logged in: %s', self._master, h(_radio_id))
elif _command == 'RPTP': # RPTPing -- client is pinging us
_radio_id = _data[7:11]
if _radio_id in self._clients \
and self._clients[_radio_id]['CONNECTION'] == "YES" \
and self._clients[_radio_id]['IP'] == _host \
and self._clients[_radio_id]['PORT'] == _port:
self._clients['LAST_PING'] = time()
self.send_packet(_radio_id, 'MSTPONG'+_radio_id)
logger.info('(%s) Received and answered RPTPING from client %s', self._master, h(_radio_id))
else:
self.transport.write('MSTNAK'+_radio_id, (_host, _port))
logger.warning('(%s) Client info from Radio ID that has not logged in: %s', self._master, h(_radio_id))
else:
logger.error('(%s) Unrecognized command from: %s. Packet: %s', self._master, h(_radio_id), h(_data))
#************************************************
# HB CLIENT CLASS
#************************************************
class HBCLIENT(DatagramProtocol):
def __init__(self, *args, **kwargs):
if len(args) == 1:
self._client = args[0]
self._config = CONFIG['CLIENTS'][self._client]
self._stats = self._config['STATS']
else:
# If we didn't get called correctly, log it!
logger.error('(%s) HBCLIENT was not called with an argument. Terminating', self._client)
sys.exit()
def startProtocol(self):
# Set up periodic loop for sending pings to the master. Run every 'PING_TIME' seconds
self._client_maintenance = task.LoopingCall(self.client_maintenance_loop)
self._client_maintenance_loop = self._client_maintenance.start(CONFIG['GLOBAL']['PING_TIME'])
def client_maintenance_loop(self):
logger.debug('(%s) Client maintenance loop started', self._client)
# If we're not connected, zero out the stats and send a login request RPTL
if self._stats['CONNECTION'] == 'NO':
self._stats['PINGS_SENT'] = 0
self._stats['PINGS_ACKD'] = 0
self._stats['CONNECTION'] = 'RTPL_SENT'
self.send_packet('RPTL'+self._config['RADIO_ID'])
logger.info('(%s) Sending login request to master', self._client)
# If we are connected, sent a ping to the master and increment the counter
if self._stats['CONNECTION'] == 'YES':
self.send_packet('RPTPING'+self._config['RADIO_ID'])
self._stats['PINGS_SENT'] += 1
logger.info('(%s) RPTPING Sent to Master. Pings Since Connected: %s', self._client, self._stats['PINGS_SENT'])
def send_packet(self, _packet):
self.transport.write(_packet, (self._config['MASTER_IP'], self._config['MASTER_PORT']))
# KEEP THE FOLLOWING COMMENTED OUT UNLESS YOU'RE DEBUGGING DEEPLY!!!!
#logger.debug('(%s) TX Packet to %s on port %s: %s', self._client, self._config['MASTER_IP'], self._config['MASTER_PORT'], h(_packet))
def dmrd_received(self, _radio_id, _data):
pass
def datagramReceived(self, _data, (_host, _port)):
# Validate that we receveived this packet from the master - security check!
if self._config['MASTER_IP'] == _host and self._config['MASTER_PORT'] == _port:
# Extract the command, which is various length, but only 4 significant characters
_command = _data[:4]
if _command == 'DMRD': # DMRData -- encapsulated DMR data frame
_radio_id = _data[4:8]
if self._config['RADIO_ID'] == _radio_id: # Check to ensure this packet is meant for us
logger.debug('(%s) DMRD Received', self._client)
self.dmrd_received(_radio_id, _data)
elif _command == 'MSTN': # Actually MSTNAK -- a NACK from the master
if self._config['RADIO_ID'] == _radio_id: # Check to ensure this packet is meant for us
print('(%s) MSTNAK Received', self._client)
self._stats['CONNECTION'] = 'NO' # Disconnect ourselves and re-register
elif _command == 'RPTA': # Actually RPTACK -- an ACK from the master
# Depending on the state, an RPTACK means different things, in each clause, we check and/or set the state
if self._stats['CONNECTION'] == 'RTPL_SENT': # If we've sent a login request...
_login_int32 = _data[6:10]
logger.info('(%s) Repeater Login ACK Received with 32bit ID: %s', self._client, h(_login_int32))
_pass_hash = sha256(_login_int32+self._config['PASSPHRASE']).hexdigest()
_pass_hash = a(_pass_hash)
self.send_packet('RPTK'+self._config['RADIO_ID']+_pass_hash)
self._stats['CONNECTION'] = 'AUTHENTICATED'
elif self._stats['CONNECTION'] == 'AUTHENTICATED': # If we've sent the login challenge...
if _data[6:10] == self._config['RADIO_ID']:
logger.info('(%s) Repeater Authentication Accepted', self._client)
_config_packet = self._config['RADIO_ID']+\
self._config['CALLSIGN']+\
self._config['RX_FREQ']+\
self._config['TX_FREQ']+\
self._config['TX_POWER']+\
self._config['COLORCODE']+\
self._config['LATITUDE']+\
self._config['LONGITUDE']+\
self._config['HEIGHT']+\
self._config['LOCATION']+\
self._config['DESCRIPTION']+\
self._config['SLOTS']+\
self._config['URL']+\
self._config['SOFTWARE_ID']+\
self._config['PACKAGE_ID']
self.send_packet('RPTC'+_config_packet)
self._stats['CONNECTION'] = 'CONFIG-SENT'
logger.info('(%s) Repeater Configuration Sent', self._client)
else:
self._stats['CONNECTION'] = 'NO'
logger.error('(%s) Master ACK Contained wrong ID - Connection Reset', self._client)
elif self._stats['CONNECTION'] == 'CONFIG-SENT': # If we've sent out configuration to the master
if _data[6:10] == self._config['RADIO_ID']:
logger.info('(%s) Repeater Configuration Accepted', self._client)
self._stats['CONNECTION'] = 'YES'
logger.info('(%s) Connection to Master Completed', self._client)
else:
self._stats['CONNECTION'] = 'NO'
logger.error('(%s) Master ACK Contained wrong ID - Connection Reset', self._client)
elif _command == 'MSTP': # Actually MSTPONG -- a reply to RPTPING (send by client)
if _data [7:11] == self._config['RADIO_ID']:
self._stats['PINGS_ACKD'] += 1
logger.info('(%s) MSTPONG Received. Total Pongs Since Connected: %s', self._client, self._stats['PINGS_ACKD'])
elif _command == 'MSTC': # Actually MSTCL -- notify us the master is closing down
if _data[5:9] == self._config['RADIO_ID']:
self._stats['CONNECTION'] = 'NO'
logger.info('(%s) MSTCL Recieved', self._client)
else:
logger.error('(%s) Received an invalid command in packet: %s', self._client, h(_data))
# Keep This Line Commented Unless HEAVILY Debugging!
#logger.debug('(%s) Received Packet: %s', self._client, h(_data))
#************************************************
# MAIN PROGRAM LOOP STARTS HERE
#************************************************
if __name__ == '__main__':
logger.info('HBlink \'HBlink.py\' (c) 2016 N0MJS & the K0USY Group - SYSTEM STARTING...')
# HBlink Master
masters = {}
for master in CONFIG['MASTERS']:
if CONFIG['MASTERS'][master]['ENABLED']:
masters[master] = HBMASTER(master)
reactor.listenUDP(CONFIG['MASTERS'][master]['PORT'], masters[master], interface=CONFIG['MASTERS'][master]['IP'])
logger.debug('MASTER instance created: %s, %s', master, masters[master])
clients = {}
for client in CONFIG['CLIENTS']:
if CONFIG['CLIENTS'][client]['ENABLED']:
clients[client] = HBCLIENT(client)
reactor.listenUDP(CONFIG['CLIENTS'][client]['PORT'], clients[client], interface=CONFIG['CLIENTS'][client]['IP'])
logger.debug('CLIENT instance created: %s, %s', client, clients[client])
reactor.run()