def handle_session(self):
Logger.debug(7, 'Session loop running')
self.incoming_message('<?xml version="1.0" encoding="UTF-8"?><hello xmlns="parrot"/>')
while True:
try:
Logger.debug(5,'NETCONF server ready, waiting for next message')
msg = self.read_msg()
except EOFError:
Logger.debug(5,'EOF -- end of session')
return
except Exception as e:
verdict = self.handle_read_exception(e)
if verdict == "kill-session":
return
if verdict == "kill-server":
Logger.info('Server terminating')
sys.exit(1)
# Else keep going
try:
if("" == msg):
Logger.debug(5,'EOF ++ end of session')
return
if self.incoming_message(msg) == True:
return
except Exception as e:
Logger.error('Exception in server processing: ' + str(e))
def run(self, host, port, parrot_file):
Logger.info(f"Parroting {parrot_file}")
try:
parrot_path = pathlib.Path(parrot_file)
env = Environment(loader=FileSystemLoader([parrot_path.parent],
followlinks=True),
autoescape=select_autoescape(['xml']))
self.server.set_template(env.get_template(str(parrot_path.name)))
self.server.set_host_port(host, port)
self.server.serve()
except Exception as e:
traceback.print_exc()
Logger.fatal(f"Top level exception: {str(e)}")
def build(self):
if self.target_filename.exists():
source_stat = self.source_filename.stat()
target_stat = self.target_filename.stat()
if source_stat.st_mtime <= target_stat.st_mtime:
Logger.info(
f"Parrot Builder, {self.target_filename} up to date")
return str(self.target_filename)
with open(self.source_filename, "r") as source_file:
with open(self.target_filename, "w") as target_file:
self._make_messages(source_file)
self._emit_messages(target_file)
return str(self.target_filename)
def process_instructions(self, reply_msg):
def split_processing_instructions(reply_msg):
instructions = []
pi_start_marker = '<?parrot '
pi_end_marker = '?>'
while True:
pi_start = reply_msg.find(pi_start_marker)
if pi_start < 0:
break
pi_end = reply_msg[pi_start:].find(pi_end_marker)
if pi_end < 0:
return ('bad-processing-instruction', reply_msg[pi_start:pi_start+20])
pi = reply_msg[pi_start+len(pi_start_marker):pi_end]
if pi_start:
instructions += [('send', reply_msg[:pi_start])]
reply_msg = reply_msg[pi_end+len(pi_end_marker):]
cmd = pi.split(" ")[0]
data = pi[len(cmd)+1:]
instructions += [(cmd, data)]
if reply_msg:
instructions += [('send', reply_msg)]
if not instructions:
instructions = [('empty-response', None)]
return instructions
instructions = split_processing_instructions(reply_msg)
end_session = False
for (cmd, data) in instructions:
if cmd == "send":
Logger.debug(6, f'Sending {len(data)} bytes', payload=data)
self.send_message(data)
elif cmd == "ignore":
Logger.debug(5, f'Not sending any response')
elif cmd == "netconf11":
Logger.debug(5, f'Switching to NETCONF 1.1')
self.choose_netconf_ver([11])
elif cmd == "netconf10":
Logger.debug(5, f'Switching to NETCONF 1.0')
self.choose_netconf_ver([10])
elif cmd == "empty-response":
Logger.warning(f'Template did not provide any response. Ending the session.')
end_session = True
elif cmd == "end-session":
Logger.info(f'Ending session')
end_session = True
else:
Logger.error(f'Unknown processing instruction "{cmd}" in template. Ending the session.')
end_session = True
return end_session
def send_msg(self, msg, netconf_ver=0):
chunk_size = 10000
if netconf_ver == 0:
netconf_ver = self.netconf_ver
msg_len = len(msg)
while msg != "":
chunk = msg[:chunk_size].encode('utf-8')
chunk_len = len(chunk)
if netconf_ver == 11:
header = f"\n#{chunk_len}\n".encode('utf-8')
Logger.debug(10, f'Sending NC11 header', payload=header)
self.channel.send(header)
Logger.debug(9, f'Sending {chunk_len} bytes chunk', payload=chunk)
self.channel.send(chunk)
msg = msg[chunk_size:]
if netconf_ver == 11:
Logger.debug(10, f'Sending NC11 delimiter', payload=self.delimiter11)
self.channel.send(self.delimiter11)
if netconf_ver == 10:
Logger.debug(10, f'Sending NC10 delimiter', payload=self.delimiter10b)
self.channel.send(self.delimiter10b)
Logger.info(f"Sent {msg_len} bytes in NC{netconf_ver} message", payload=msg)
def handle_connection(self, host_key):
try:
DoGSSAPIKeyExchange = False
t = Transport(self.sock, gss_kex=DoGSSAPIKeyExchange)
t.set_subsystem_handler('netconf', self.subsys)
t.set_gss_host(socket.getfqdn(""))
try:
t.load_server_moduli()
except:
Logger.warning('Failed to load moduli -- gex will be unsupported.')
t.add_server_key(host_key)
server = Server()
t.start_server(server=server)
# wait for auth
self.channel = t.accept(20)
if self.channel is None:
Logger.error('No SSH channel')
return
Logger.info('Waiting for message')
server.event.wait(10)
Logger.info('Closing')
##self.channel.close()
Logger.info('Client connection closed')
except ConnectionResetError as e:
Logger.debug(5,'Connection reset by peer')
except SSHException:
Logger.error('SSH negotiation failed, client connection dropped')
except Exception as e:
Logger.error('Caught exception: ' + str(e.__class__) + ': ' + str(e))
traceback.print_exc()
try:
t.close()
except:
pass
def listen(self):
NETCONF_Server.set_instance(self)
try:
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
#sock.bind(('', self.port))
sock.bind((self.host, self.port))
except Exception as e:
Logger.fatal('Bind failed: ' + str(e))
try:
sock.listen(100)
except Exception as e:
Logger.fatal('Listen failed: ' + str(e))
Logger.info(f'Listening for connections on port {self.port}...')
host_key = None
try:
host_key = RSAKey(filename=self.host_key_filename)
except:
pass
if not host_key:
Logger.info(f'Generating new host key')
host_key = RSAKey.generate(2048)
if self.host_key_filename:
host_key.write_private_key_file(self.host_key_filename, password=None)
Logger.info(f"Wrote host key to file, '{self.host_key_filename}'")
while True:
try:
Logger.info(f'Waiting for client to connect')
client, addr = sock.accept()
except Exception as e:
Logger.fatal('Accept failed: ' + str(e))
self.sock = client
(ip, port) = addr
Logger.info(f'Client {ip}:{port} connected')
self.handle_connection(host_key)
Logger.info(f'Client {ip}:{port} disconnected')
