import os import shutil import socket from twisted.internet import reactor from twisted.logger import Logger import psutil try: # psutil < 2.0.0 from psutil.error import AccessDenied as psutil_AccessDenied PSUTIL_2 = False except ImportError: # psutil >= 2.0.0 from psutil import AccessDenied as psutil_AccessDenied PSUTIL_2 = True from leap.bitmask.vpn._telnet import UDSTelnet class OpenVPNAlreadyRunning(Exception): message = ("Another openvpn instance is already running, and could " "not be stopped.") class AlienOpenVPNAlreadyRunning(Exception): message = ("Another openvpn instance is already running, and could " "not be stopped because it was not launched by LEAP.") class ImproperlyConfigured(Exception): pass class VPNManagement(object): """ This is a mixin that we use in the VPNProcess class. Here we get together all methods related with the openvpn management interface. For more info about management methods:: zcat `dpkg -L openvpn | grep management` """ log = Logger() # Timers, in secs CONNECTION_RETRY_TIME = 1 def __init__(self): self._tn = None self.aborted = False self._host = None self._port = None self._last_state = None self._last_status = None self._status = None self._logs = {} def set_connection(self, host, port): """ :param host: either socket path (unix) or socket IP :type host: str :param port: either string "unix" if it's a unix socket, or port otherwise """ self._host = host self._port = port def set_watcher(self, watcher): self._watcher = watcher def is_connected(self): return bool(self._tn) def connect(self): if not self._host or not self._port: raise ImproperlyConfigured('Connection is not configured') if self.is_connected(): self._close_management_socket() try: self._tn = UDSTelnet(self._host, self._port) self._tn.read_eager() except Exception as e: self.log.warn('Could not connect to OpenVPN yet: %r' % (e,)) self._tn = None if self._tn: return True else: self.log.error('Error while connecting to management!') return False def connect_retry(self, retry=0, max_retries=None): """ Attempts to connect to a management interface, and retries after CONNECTION_RETRY_TIME if not successful. :param retry: number of the retry :type retry: int """ if max_retries and retry > max_retries: self.log.warn( 'Max retries reached while attempting to connect ' 'to management. Aborting.') self.aborted = True return if not self.aborted and not self.is_connected(): self.connect() reactor.callLater( self.CONNECTION_RETRY_TIME, self.connect_retry, retry + 1) def process_log(self): if not self._watcher: return lines = self._send_command('log 20') for line in lines: try: splitted = line.split(',') ts = splitted[0] msg = ','.join(splitted[2:]) if ts not in self._logs: self._watcher.watch(msg) self.log.info('VPN: %s' % msg) self._logs[ts] = msg except Exception: pass def _seek_to_eof(self): """ Read as much as available. Position seek pointer to end of stream """ try: self._tn.read_eager() except EOFError: self.log.debug('Could not read from socket. Assuming it died.') return def _send_command(self, command, until=b"END"): """ Sends a command to the telnet connection and reads until END is reached. :param command: command to send :type command: str :param until: byte delimiter string for reading command output :type until: byte str :return: response read :rtype: list """ try: self._tn.write("%s\n" % (command,)) buf = self._tn.read_until(until, 2) self._seek_to_eof() blist = buf.split('\r\n') if blist[-1].startswith(until): del blist[-1] return blist else: return [] except socket.error: # XXX should get a counter and repeat only # after mod X times. self.log.warn('Socket error (command was: "%s")' % (command,)) self._close_management_socket(announce=False) self.log.debug('Trying to connect to management again') self.connect_retry(max_retries=5) return [] except Exception as e: self.log.warn("Error sending command %s: %r" % (command, e)) return [] def _close_management_socket(self, announce=True): """ Close connection to openvpn management interface. """ if announce: self._tn.write("quit\n") self._tn.read_all() self._tn.get_socket().close() self._tn = None def _parse_state_and_notify(self, output): """ Parses the output of the state command, and trigger a state transition when the state changes. :param output: list of lines that the state command printed as its output :type output: list """ for line in output: stripped = line.strip() if stripped == "END": continue parts = stripped.split(",") if len(parts) < 5: continue try: ts, status_step, ok, ip, remote, port, _, _, _ = parts except ValueError: ts, status_step, ok, ip, remote, port, _, _ = parts state = status_step if state != self._last_state: # XXX this status object is the vpn status observer if self._status: self._status.set_status(state, None) self._last_state = state def _parse_status_and_notify(self, output): """ Parses the output of the status command and emits status_changed signal when the status changes. :param output: list of lines that the status command printed as its output :type output: list """ tun_tap_read = "" tun_tap_write = "" for line in output: stripped = line.strip() if stripped.endswith("STATISTICS") or stripped == "END": continue parts = stripped.split(",") if len(parts) < 2: continue try: text, value = parts except ValueError: self.log.debug('Could not parse %s' % parts) return # text can be: # "TUN/TAP read bytes" # "TUN/TAP write bytes" # "TCP/UDP read bytes" # "TCP/UDP write bytes" # "Auth read bytes" if text == "TUN/TAP read bytes": tun_tap_read = value # download elif text == "TUN/TAP write bytes": tun_tap_write = value # upload traffic_status = (tun_tap_read, tun_tap_write) if traffic_status != self._last_status: if self._status: self._status.set_traffic_status(traffic_status) self._last_status = traffic_status def get_state(self): """ Notifies the gui of the output of the state command over the openvpn management interface. """ if self.is_connected(): return self._parse_state_and_notify(self._send_command("state")) def get_status(self): """ Notifies the gui of the output of the status command over the openvpn management interface. """ if self.is_connected(): return self._parse_status_and_notify(self._send_command("status")) def terminate_openvpn(self, shutdown=False): """ Attempts to terminate openvpn by sending a SIGTERM. """ if self.is_connected(): self._send_command("signal SIGTERM") if shutdown: self._cleanup_tempfiles() def _cleanup_tempfiles(self): """ Remove all temporal files we might have left behind. Iif self.port is 'unix', we have created a temporal socket path that, under normal circumstances, we should be able to delete. """ if self._socket_port == "unix": tempfolder = _first(os.path.split(self._host)) if tempfolder and os.path.isdir(tempfolder): try: shutil.rmtree(tempfolder) except OSError: self.log.error( 'Could not delete tmpfolder %s' % tempfolder) def get_openvpn_process(self): """ Looks for openvpn instances running. :rtype: process """ openvpn_process = None for p in psutil.process_iter(): try: # XXX Not exact! # Will give false positives. # we should check that cmdline BEGINS # with openvpn or with our wrapper # (pkexec / osascript / whatever) # This needs more work, see #3268, but for the moment # we need to be able to filter out arguments in the form # --openvpn-foo, since otherwise we are shooting ourselves # in the feet. if PSUTIL_2: cmdline = p.cmdline() else: cmdline = p.cmdline if any(map(lambda s: s.find( "LEAPOPENVPN") != -1, cmdline)): openvpn_process = p break except psutil_AccessDenied: pass return openvpn_process def stop_if_already_running(self): """ Checks if VPN is already running and tries to stop it. Might raise OpenVPNAlreadyRunning. :return: True if stopped, False otherwise """ process = self.get_openvpn_process() if not process: self.log.debug('Could not find openvpn process while ' 'trying to stop it.') return self.log.debug('OpenVPN is already running, trying to stop it...') cmdline = process.cmdline manag_flag = "--management" if isinstance(cmdline, list) and manag_flag in cmdline: # we know that our invocation has this distinctive fragment, so # we use this fingerprint to tell other invocations apart. # this might break if we change the configuration path in the # launchers def smellslikeleap(s): return "leap" in s and "providers" in s if not any(map(smellslikeleap, cmdline)): self.log.debug("We cannot stop this instance since we do not " "recognise it as a leap invocation.") raise AlienOpenVPNAlreadyRunning try: index = cmdline.index(manag_flag) host = cmdline[index + 1] port = cmdline[index + 2] self.log.debug("Trying to connect to %s:%s" % (host, port)) self.connect() # XXX this has a problem with connections to different # remotes. So the reconnection will only work when we are # terminating instances left running for the same provider. # If we are killing an openvpn instance configured for another # provider, we will get: # TLS Error: local/remote TLS keys are out of sync # However, that should be a rare case right now. self._send_command("signal SIGTERM") self._close_management_socket(announce=True) except (Exception, AssertionError): self.log.failure('Problem trying to terminate OpenVPN') else: self.log.debug('Could not find the expected openvpn command line.') process = self.get_openvpn_process() if process is None: self.log.debug('Successfully finished already running ' 'openvpn process.') return True else: self.log.warn('Unable to terminate OpenVPN') raise OpenVPNAlreadyRunning def _first(things): try: return things[0] except (IndexError, TypeError): return None