def __init__(self, configurations): self._ips = environment.settings().tcp.bind self._port = environment.settings().tcp.port self._stopping = environment.settings().tcp.once self.exit_code = self.Exit.unknown self.max_loop_time = environment.settings().reactor.speed self._sleep_time = self.max_loop_time / 100 self._busyspin = {} self._ratelimit = {} self.early_drop = environment.settings().daemon.drop self.processes = None self.configuration = Configuration(configurations) self.logger = Logger() self.asynchronous = ASYNC() self.signal = Signal() self.daemon = Daemon(self) self.listener = Listener(self) self.api = API(self) self._peers = {} self._reload_processes = False self._saved_pid = False self._poller = select.poll()
def __init__ (self, configurations): self._ips = environment.settings().tcp.bind self._port = environment.settings().tcp.port self._stopping = environment.settings().tcp.once self.exit_code = self.Exit.unknown self.max_loop_time = environment.settings().reactor.speed self._sleep_time = self.max_loop_time / 100 self._busyspin = {} self.early_drop = environment.settings().daemon.drop self.processes = None self.configuration = Configuration(configurations) self.logger = Logger() self.asynchronous = ASYNC() self.signal = Signal() self.daemon = Daemon(self) self.listener = Listener(self) self.api = API(self) self.peers = {} self._reload_processes = False self._saved_pid = False
def signal(self, neighbor, signal): return self._header( self._neighbor(neighbor, None, self._kv({'code': '%d' % signal, 'name': Signal.name(signal),})), '', '', neighbor, message_type='signal', )
def __init__(self, configurations): self._ips = environment.settings().tcp.bind self._port = environment.settings().tcp.port self._stopping = environment.settings().tcp.once self.max_loop_time = environment.settings().reactor.speed self.early_drop = environment.settings().daemon.drop self.processes = None self.configuration = Configuration(configurations) self.logger = Logger() self. async = ASYNC() self.signal = Signal() self.daemon = Daemon(self) self.listener = Listener(self) self.api = API(self) self.peers = {} self._reload_processes = False self._saved_pid = False
class Reactor(object): class Exit(object): normal = 0 validate = 0 listening = 1 configuration = 1 privileges = 1 log = 1 pid = 1 socket = 1 io_error = 1 process = 1 select = 1 unknown = 1 # [hex(ord(c)) for c in os.popen('clear').read()] clear = concat_bytes_i( character(int(c, 16)) for c in ['0x1b', '0x5b', '0x48', '0x1b', '0x5b', '0x32', '0x4a']) def __init__(self, configurations): self._ips = environment.settings().tcp.bind self._port = environment.settings().tcp.port self._stopping = environment.settings().tcp.once self.exit_code = self.Exit.unknown self.max_loop_time = environment.settings().reactor.speed self._sleep_time = self.max_loop_time / 100 self._busyspin = {} self._ratelimit = {} self.early_drop = environment.settings().daemon.drop self.processes = None self.configuration = Configuration(configurations) self.logger = Logger() self.asynchronous = ASYNC() self.signal = Signal() self.daemon = Daemon(self) self.listener = Listener(self) self.api = API(self) self._peers = {} self._reload_processes = False self._saved_pid = False self._poller = select.poll() def _termination(self, reason, exit_code): self.exit_code = exit_code self.signal.received = Signal.SHUTDOWN self.logger.critical(reason, 'reactor') def _prevent_spin(self): second = int(time.time()) if not second in self._busyspin: self._busyspin = {second: 0} self._busyspin[second] += 1 if self._busyspin[second] > self.max_loop_time: time.sleep(self._sleep_time) return True return False def _rate_limited(self, peer, rate): if rate <= 0: return False second = int(time.time()) ratelimit = self._ratelimit.get(peer, {}) if not second in ratelimit: self._ratelimit[peer] = {second: rate - 1} return False if self._ratelimit[peer][second] > 0: self._ratelimit[peer][second] -= 1 return False return True def _wait_for_io(self, sleeptime): spin_prevention = False try: for fd, event in self._poller.poll(sleeptime): if event & select.POLLIN or event & select.POLLPRI: yield fd continue elif event & select.POLLHUP or event & select.POLLERR or event & select.POLLNVAL: spin_prevention = True continue if spin_prevention: self._prevent_spin() except KeyboardInterrupt: self._termination('^C received', self.Exit.normal) return except Exception: self._prevent_spin() return # peer related functions def active_peers(self): peers = set() for key, peer in self._peers.items(): if not peer.neighbor.passive or peer.proto: peers.add(key) return peers def established_peers(self): peers = set() for key, peer in self._peers.items(): if peer.fsm == FSM.ESTABLISHED: peers.add(key) return peers def peers(self): return list(self._peers) def handle_connection(self, peer_name, connection): peer = self._peers.get(peer_name, None) if not peer: self.logger.critical('could not find referenced peer', 'reactor') return peer.handle_connection(connection) def neighbor(self, peer_name): peer = self._peers.get(peer_name, None) if not peer: self.logger.critical('could not find referenced peer', 'reactor') return return peer.neighbor def neighbor_name(self, peer_name): peer = self._peers.get(peer_name, None) if not peer: self.logger.critical('could not find referenced peer', 'reactor') return "" return peer.neighbor.name() def neighbor_ip(self, peer_name): peer = self._peers.get(peer_name, None) if not peer: self.logger.critical('could not find referenced peer', 'reactor') return "" return str(peer.neighbor.peer_address) def neighbor_cli_data(self, peer_name): peer = self._peers.get(peer_name, None) if not peer: self.logger.critical('could not find referenced peer', 'reactor') return "" return peer.cli_data() def neighor_rib(self, peer_name, rib_name, advertised=False): peer = self._peers.get(peer_name, None) if not peer: self.logger.critical('could not find referenced peer', 'reactor') return [] families = None if advertised: families = peer.proto.negotiated.families if peer.proto else [] rib = peer.neighbor.rib.outgoing if rib_name == 'out' else peer.neighbor.rib.incoming return list(rib.cached_changes(families)) def neighbor_rib_resend(self, peer_name): peer = self._peers.get(peer_name, None) if not peer: self.logger.critical('could not find referenced peer', 'reactor') return peer.neighbor.rib.outgoing.resend(None, peer.neighbor.route_refresh) def neighbor_rib_out_withdraw(self, peer_name): peer = self._peers.get(peer_name, None) if not peer: self.logger.critical('could not find referenced peer', 'reactor') return peer.neighbor.rib.outgoing.withdraw(None, peer.neighbor.route_refresh) def neighbor_rib_in_clear(self, peer_name): peer = self._peers.get(peer_name, None) if not peer: self.logger.critical('could not find referenced peer', 'reactor') return peer.neighbor.rib.incoming.clear() # ... def _completed(self, peers): for peer in peers: if self._peers[peer].neighbor.rib.outgoing.pending(): return False return True def run(self, validate, root): self.daemon.daemonise() # Make sure we create processes once we have closed file descriptor # unfortunately, this must be done before reading the configuration file # so we can not do it with dropped privileges self.processes = Processes() # we have to read the configuration possibly with root privileges # as we need the MD5 information when we bind, and root is needed # to bind to a port < 1024 # this is undesirable as : # - handling user generated data as root should be avoided # - we may not be able to reload the configuration once the privileges are dropped # but I can not see any way to avoid it for ip in self._ips: if not self.listener.listen_on(ip, None, self._port, None, False, None): return self.Exit.listening if not self.load(): return self.Exit.configuration if validate: # only validate configuration self.logger.warning('', 'configuration') self.logger.warning('parsed Neighbors, un-templated', 'configuration') self.logger.warning('------------------------------', 'configuration') self.logger.warning('', 'configuration') for key in self._peers: self.logger.warning(str(self._peers[key].neighbor), 'configuration') self.logger.warning('', 'configuration') return self.Exit.validate for neighbor in self.configuration.neighbors.values(): if neighbor.listen: if not self.listener.listen_on( neighbor.md5_ip, neighbor.peer_address, neighbor.listen, neighbor.md5_password, neighbor.md5_base64, neighbor.ttl_in): return self.Exit.listening if not self.early_drop: self.processes.start(self.configuration.processes) if not self.daemon.drop_privileges(): self.logger.critical( 'could not drop privileges to \'%s\' refusing to run as root' % self.daemon.user, 'reactor') self.logger.critical( 'set the environmemnt value exabgp.daemon.user to change the unprivileged user', 'reactor') return self.Exit.privileges if self.early_drop: self.processes.start(self.configuration.processes) # This is required to make sure we can write in the log location as we now have dropped root privileges if not self.logger.restart(): self.logger.critical('could not setup the logger, aborting', 'reactor') return self.Exit.log if not self.daemon.savepid(): return self.Exit.pid # did we complete the run of updates caused by the last SIGUSR1/SIGUSR2 ? reload_completed = False wait = environment.settings().tcp.delay if wait: sleeptime = (wait * 60) - int(time.time()) % (wait * 60) self.logger.debug( 'waiting for %d seconds before connecting' % sleeptime, 'reactor') time.sleep(float(sleeptime)) workers = {} peers = set() api_fds = [] ms_sleep = int(self._sleep_time * 1000) while True: try: if self.signal.received: for key in self._peers: if self._peers[key].neighbor.api['signal']: self._peers[key].reactor.processes.signal( self._peers[key].neighbor, self.signal.number) signaled = self.signal.received self.signal.rearm() if signaled == Signal.SHUTDOWN: self.exit_code = self.Exit.normal self.shutdown() break if signaled == Signal.RESTART: self.restart() continue if not reload_completed: continue if signaled == Signal.FULL_RELOAD: self._reload_processes = True if signaled in (Signal.RELOAD, Signal.FULL_RELOAD): self.load() self.processes.start(self.configuration.processes, self._reload_processes) self._reload_processes = False continue if self.listener.incoming(): # check all incoming connection self.asynchronous.schedule( str(uuid.uuid1()), 'checking for new connection(s)', self.listener.new_connections()) peers = self.active_peers() if self._completed(peers): reload_completed = True sleep = ms_sleep # do not attempt to listen on closed sockets even if the peer is still here for io in list(workers.keys()): if io == -1: self._poller.unregister(io) del workers[io] # give a turn to all the peers for key in list(peers): peer = self._peers[key] # limit the number of message handling per second if self._rate_limited(key, peer.neighbor.rate_limit): peers.discard(key) continue # handle the peer action = peer.run() # .run() returns an ACTION enum: # * immediate if it wants to be called again # * later if it should be called again but has no work atm # * close if it is finished and is closing down, or restarting if action == ACTION.CLOSE: if key in self._peers: del self._peers[key] peers.discard(key) # we are loosing this peer, not point to schedule more process work elif action == ACTION.LATER: io = peer.socket() if io != -1: self._poller.register( io, select.POLLIN | select.POLLPRI | select.POLLHUP | select.POLLNVAL | select.POLLERR) workers[io] = key # no need to come back to it before a a full cycle peers.discard(key) elif action == ACTION.NOW: sleep = 0 if not peers: break # read at least on message per process if there is some and parse it for service, command in self.processes.received(): self.api.text(self, service, command) sleep = 0 self.asynchronous.run() if api_fds != self.processes.fds: for fd in api_fds: if fd == -1: continue if fd not in self.processes.fds: self._poller.unregister(fd) for fd in self.processes.fds: if fd == -1: continue if fd not in api_fds: self._poller.register( fd, select.POLLIN | select.POLLPRI | select.POLLHUP | select.POLLNVAL | select.POLLERR) api_fds = self.processes.fds for io in self._wait_for_io(sleep): if io not in api_fds: peers.add(workers[io]) if self._stopping and not self._peers.keys(): self._termination('exiting on peer termination', self.Exit.normal) except KeyboardInterrupt: self._termination('^C received', self.Exit.normal) except SystemExit: self._termination('exiting', self.Exit.normal) # socket.error is a subclass of IOError (so catch it first) except socket.error: self._termination('socket error received', self.Exit.socket) except IOError: self._termination( 'I/O Error received, most likely ^C during IO', self.Exit.io_error) except ProcessError: self._termination( 'Problem when sending message(s) to helper program, stopping', self.Exit.process) except select.error: self._termination('problem using select, stopping', self.Exit.select) return self.exit_code def register_peer(self, name, peer): self._peers[name] = peer def teardown_peer(self, name, code): self._peers[name].teardown(code) def shutdown(self): """Terminate all the current BGP connections""" self.logger.critical('performing shutdown', 'reactor') if self.listener: self.listener.stop() self.listener = None for key in self._peers.keys(): self._peers[key].shutdown() self.asynchronous.clear() self.processes.terminate() self.daemon.removepid() self._stopping = True def load(self): """Reload the configuration and send to the peer the route which changed""" self.logger.notice('performing reload of exabgp %s' % version, 'configuration') reloaded = self.configuration.reload() if not reloaded: # # Careful the string below is used but the QA code to check for sucess of failure self.logger.error( 'not reloaded, no change found in the configuration', 'configuration') # Careful the string above is used but the QA code to check for sucess of failure # self.logger.error(str(self.configuration.error), 'configuration') return False for key, peer in self._peers.items(): if key not in self.configuration.neighbors: self.logger.debug('removing peer: %s' % peer.neighbor.name(), 'reactor') peer.remove() for key, neighbor in self.configuration.neighbors.items(): # new peer if key not in self._peers: self.logger.debug('new peer: %s' % neighbor.name(), 'reactor') peer = Peer(neighbor, self) self._peers[key] = peer # modified peer elif self._peers[key].neighbor != neighbor: self.logger.debug( 'peer definition change, establishing a new connection for %s' % str(key), 'reactor') self._peers[key].reestablish(neighbor) # same peer but perhaps not the routes else: # finding what route changed and sending the delta is not obvious self.logger.debug( 'peer definition identical, updating peer routes if required for %s' % str(key), 'reactor') self._peers[key].reconfigure(neighbor) for ip in self._ips: if ip.afi == neighbor.peer_address.afi: self.listener.listen_on(ip, neighbor.peer_address, self._port, neighbor.md5_password, neighbor.md5_base64, None) self.logger.notice('loaded new configuration successfully', 'reactor') return True def restart(self): """Kill the BGP session and restart it""" self.logger.notice('performing restart of exabgp %s' % version, 'reactor') # XXX: FIXME: Could return False, in case there is interference with old config... reloaded = self.configuration.reload() for key in self._peers.keys(): if key not in self.configuration.neighbors.keys(): peer = self._peers[key] self.logger.debug('removing peer %s' % peer.neighbor.name(), 'reactor') self._peers[key].remove() else: self._peers[key].reestablish() self.processes.start(self.configuration.processes, True)
class Reactor (object): class Exit (object): normal = 0 validate = 0 listening = 1 configuration = 1 privileges = 1 log = 1 pid = 1 socket = 1 io_error = 1 process = 1 select = 1 unknown = 1 # [hex(ord(c)) for c in os.popen('clear').read()] clear = concat_bytes_i(character(int(c,16)) for c in ['0x1b', '0x5b', '0x48', '0x1b', '0x5b', '0x32', '0x4a']) def __init__ (self, configurations): self._ips = environment.settings().tcp.bind self._port = environment.settings().tcp.port self._stopping = environment.settings().tcp.once self.exit_code = self.Exit.unknown self.max_loop_time = environment.settings().reactor.speed self._sleep_time = self.max_loop_time / 100 self._busyspin = {} self.early_drop = environment.settings().daemon.drop self.processes = None self.configuration = Configuration(configurations) self.logger = Logger() self.asynchronous = ASYNC() self.signal = Signal() self.daemon = Daemon(self) self.listener = Listener(self) self.api = API(self) self.peers = {} self._reload_processes = False self._saved_pid = False def _termination (self,reason, exit_code): self.exit_code = exit_code self.signal.received = Signal.SHUTDOWN self.logger.critical(reason,'reactor') def _prevent_spin(self): second = int(time.time()) if not second in self._busyspin: self._busyspin = {second: 0} self._busyspin[second] += 1 if self._busyspin[second] > self.max_loop_time: time.sleep(self._sleep_time) return True return False def _api_ready (self,sockets,sleeptime): fds = self.processes.fds() ios = fds + sockets try: read,_,_ = select.select(ios,[],[],sleeptime) for fd in fds: if fd in read: read.remove(fd) return read except select.error as exc: err_no,message = exc.args # pylint: disable=W0633 if err_no not in error.block: raise exc self._prevent_spin() return [] except socket.error as exc: # python 3 does not raise on closed FD, but python2 does # we have lost a peer and it is causing the select # to complain, the code will self-heal, ignore the issue # (EBADF from python2 must be ignored if when checkign error.fatal) # otherwise sending notification causes TCP to drop and cause # this code to kill ExaBGP self._prevent_spin() return [] except ValueError as exc: # The peer closing the TCP connection lead to a negative file descritor self._prevent_spin() return [] except KeyboardInterrupt: self._termination('^C received',self.Exit.normal) return [] def _active_peers (self): peers = set() for key,peer in self.peers.items(): if not peer.neighbor.passive or peer.proto: peers.add(key) return peers def _completed (self,peers): for peer in peers: if self.peers[peer].neighbor.rib.outgoing.pending(): return False return True def run (self, validate, root): self.daemon.daemonise() # Make sure we create processes once we have closed file descriptor # unfortunately, this must be done before reading the configuration file # so we can not do it with dropped privileges self.processes = Processes() # we have to read the configuration possibly with root privileges # as we need the MD5 information when we bind, and root is needed # to bind to a port < 1024 # this is undesirable as : # - handling user generated data as root should be avoided # - we may not be able to reload the configuration once the privileges are dropped # but I can not see any way to avoid it for ip in self._ips: if not self.listener.listen_on(ip, None, self._port, None, False, None): return self.Exit.listening if not self.load(): return self.Exit.configuration if validate: # only validate configuration self.logger.warning('','configuration') self.logger.warning('parsed Neighbors, un-templated','configuration') self.logger.warning('------------------------------','configuration') self.logger.warning('','configuration') for key in self.peers: self.logger.warning(str(self.peers[key].neighbor),'configuration') self.logger.warning('','configuration') return self.Exit.validate for neighbor in self.configuration.neighbors.values(): if neighbor.listen: if not self.listener.listen_on(neighbor.md5_ip, neighbor.peer_address, neighbor.listen, neighbor.md5_password, neighbor.md5_base64, neighbor.ttl_in): return self.Exit.listening if not self.early_drop: self.processes.start(self.configuration.processes) if not self.daemon.drop_privileges(): self.logger.critical('could not drop privileges to \'%s\' refusing to run as root' % self.daemon.user,'reactor') self.logger.critical('set the environmemnt value exabgp.daemon.user to change the unprivileged user','reactor') return self.Exit.privileges if self.early_drop: self.processes.start(self.configuration.processes) # This is required to make sure we can write in the log location as we now have dropped root privileges if not self.logger.restart(): self.logger.critical('could not setup the logger, aborting','reactor') return self.Exit.log if not self.daemon.savepid(): return self.Exit.pid # did we complete the run of updates caused by the last SIGUSR1/SIGUSR2 ? reload_completed = False wait = environment.settings().tcp.delay if wait: sleeptime = (wait * 60) - int(time.time()) % (wait * 60) self.logger.debug('waiting for %d seconds before connecting' % sleeptime,'reactor') time.sleep(float(sleeptime)) workers = {} peers = set() while True: try: if self.signal.received: for key in self.peers: if self.peers[key].neighbor.api['signal']: self.peers[key].reactor.processes.signal(self.peers[key].neighbor,self.signal.number) signaled = self.signal.received self.signal.rearm() if signaled == Signal.SHUTDOWN: self.shutdown() break if signaled == Signal.RESTART: self.restart() continue if not reload_completed: continue if signaled == Signal.FULL_RELOAD: self._reload_processes = True if signaled in (Signal.RELOAD, Signal.FULL_RELOAD): self.load() self.processes.start(self.configuration.processes,self._reload_processes) self._reload_processes = False continue if self.listener.incoming(): # check all incoming connection self.asynchronous.schedule(str(uuid.uuid1()),'checking for new connection(s)',self.listener.new_connections()) peers = self._active_peers() if self._completed(peers): reload_completed = True sleep = self._sleep_time # do not attempt to listen on closed sockets even if the peer is still here for io in list(workers.keys()): if io.fileno() == -1: del workers[io] # give a turn to all the peers for key in list(peers): peer = self.peers[key] action = peer.run() # .run() returns an ACTION enum: # * immediate if it wants to be called again # * later if it should be called again but has no work atm # * close if it is finished and is closing down, or restarting if action == ACTION.CLOSE: if key in self.peers: del self.peers[key] peers.discard(key) # we are loosing this peer, not point to schedule more process work elif action == ACTION.LATER: for io in peer.sockets(): workers[io] = key # no need to come back to it before a a full cycle peers.discard(key) elif action == ACTION.NOW: sleep = 0 if not peers: break # read at least on message per process if there is some and parse it for service,command in self.processes.received(): self.api.text(self,service,command) sleep = 0 self.asynchronous.run() for io in self._api_ready(list(workers),sleep): peers.add(workers[io]) del workers[io] if self._stopping and not self.peers.keys(): self._termination('exiting on peer termination',self.Exit.normal) except KeyboardInterrupt: self._termination('^C received',self.Exit.normal) except SystemExit: self._termination('exiting', self.Exit.normal) # socket.error is a subclass of IOError (so catch it first) except socket.error: self._termination('socket error received',self.Exit.socket) except IOError: self._termination('I/O Error received, most likely ^C during IO',self.Exit.io_error) except ProcessError: self._termination('Problem when sending message(s) to helper program, stopping',self.Exit.process) except select.error: self._termination('problem using select, stopping',self.Exit.select) return self.exit_code def shutdown (self): """Terminate all the current BGP connections""" self.logger.critical('performing shutdown','reactor') if self.listener: self.listener.stop() self.listener = None for key in self.peers.keys(): self.peers[key].shutdown() self.asynchronous.clear() self.processes.terminate() self.daemon.removepid() self._stopping = True def load (self): """Reload the configuration and send to the peer the route which changed""" self.logger.notice('performing reload of exabgp %s' % version,'configuration') reloaded = self.configuration.reload() if not reloaded: # # Careful the string below is used but the QA code to check for sucess of failure self.logger.error('problem with the configuration file, no change done','configuration') # Careful the string above is used but the QA code to check for sucess of failure # self.logger.error(str(self.configuration.error),'configuration') return False for key, peer in self.peers.items(): if key not in self.configuration.neighbors: self.logger.debug('removing peer: %s' % peer.neighbor.name(),'reactor') peer.remove() for key, neighbor in self.configuration.neighbors.items(): # new peer if key not in self.peers: self.logger.debug('new peer: %s' % neighbor.name(),'reactor') peer = Peer(neighbor,self) self.peers[key] = peer # modified peer elif self.peers[key].neighbor != neighbor: self.logger.debug('peer definition change, establishing a new connection for %s' % str(key),'reactor') self.peers[key].reestablish(neighbor) # same peer but perhaps not the routes else: # finding what route changed and sending the delta is not obvious self.logger.debug('peer definition identical, updating peer routes if required for %s' % str(key),'reactor') self.peers[key].reconfigure(neighbor) for ip in self._ips: if ip.afi == neighbor.peer_address.afi: self.listener.listen_on(ip, neighbor.peer_address, self._port, neighbor.md5_password, neighbor.md5_base64, None) self.logger.notice('loaded new configuration successfully','reactor') return True def restart (self): """Kill the BGP session and restart it""" self.logger.notice('performing restart of exabgp %s' % version,'reactor') self.configuration.reload() for key in self.peers.keys(): if key not in self.configuration.neighbors.keys(): neighbor = self.configuration.neighbors[key] self.logger.debug('removing Peer %s' % neighbor.name(),'reactor') self.peers[key].remove() else: self.peers[key].reestablish() self.processes.start(self.configuration.processes,True)
class Reactor(object): class Exit(object): normal = 0 validate = 0 listening = 1 configuration = 1 privileges = 1 log = 1 pid = 1 socket = 1 io_error = 1 process = 1 select = 1 unknown = 1 # [hex(ord(c)) for c in os.popen('clear').read()] clear = concat_bytes_i( character(int(c, 16)) for c in ['0x1b', '0x5b', '0x48', '0x1b', '0x5b', '0x32', '0x4a']) def __init__(self, configurations): self._ips = environment.settings().tcp.bind self._port = environment.settings().tcp.port self._stopping = environment.settings().tcp.once self.exit_code = self.Exit.unknown self.max_loop_time = environment.settings().reactor.speed self._sleep_time = self.max_loop_time / 100 self._busyspin = {} self.early_drop = environment.settings().daemon.drop self.processes = None self.configuration = Configuration(configurations) self.logger = Logger() self.asynchronous = ASYNC() self.signal = Signal() self.daemon = Daemon(self) self.listener = Listener(self) self.api = API(self) self.peers = {} self._reload_processes = False self._saved_pid = False def _termination(self, reason, exit_code): self.exit_code = exit_code self.signal.received = Signal.SHUTDOWN self.logger.critical(reason, 'reactor') def _prevent_spin(self): second = int(time.time()) if not second in self._busyspin: self._busyspin = {second: 0} self._busyspin[second] += 1 if self._busyspin[second] > self.max_loop_time: time.sleep(self._sleep_time) return True return False def _api_ready(self, sockets, sleeptime): fds = self.processes.fds() ios = fds + sockets try: read, _, _ = select.select(ios, [], [], sleeptime) for fd in fds: if fd in read: read.remove(fd) return read except select.error as exc: err_no, message = exc.args # pylint: disable=W0633 if err_no not in error.block: raise exc self._prevent_spin() return [] except socket.error as exc: # python 3 does not raise on closed FD, but python2 does # we have lost a peer and it is causing the select # to complain, the code will self-heal, ignore the issue # (EBADF from python2 must be ignored if when checkign error.fatal) # otherwise sending notification causes TCP to drop and cause # this code to kill ExaBGP self._prevent_spin() return [] except ValueError as exc: # The peer closing the TCP connection lead to a negative file descritor self._prevent_spin() return [] except KeyboardInterrupt: self._termination('^C received', self.Exit.normal) return [] def _active_peers(self): peers = set() for key, peer in self.peers.items(): if not peer.neighbor.passive or peer.proto: peers.add(key) return peers def _completed(self, peers): for peer in peers: if self.peers[peer].neighbor.rib.outgoing.pending(): return False return True def run(self, validate, root): self.daemon.daemonise() # Make sure we create processes once we have closed file descriptor # unfortunately, this must be done before reading the configuration file # so we can not do it with dropped privileges self.processes = Processes() # we have to read the configuration possibly with root privileges # as we need the MD5 information when we bind, and root is needed # to bind to a port < 1024 # this is undesirable as : # - handling user generated data as root should be avoided # - we may not be able to reload the configuration once the privileges are dropped # but I can not see any way to avoid it for ip in self._ips: if not self.listener.listen_on(ip, None, self._port, None, False, None): return self.Exit.listening if not self.load(): return self.Exit.configuration if validate: # only validate configuration self.logger.warning('', 'configuration') self.logger.warning('parsed Neighbors, un-templated', 'configuration') self.logger.warning('------------------------------', 'configuration') self.logger.warning('', 'configuration') for key in self.peers: self.logger.warning(str(self.peers[key].neighbor), 'configuration') self.logger.warning('', 'configuration') return self.Exit.validate for neighbor in self.configuration.neighbors.values(): if neighbor.listen: if not self.listener.listen_on( neighbor.md5_ip, neighbor.peer_address, neighbor.listen, neighbor.md5_password, neighbor.md5_base64, neighbor.ttl_in): return self.Exit.listening if not self.early_drop: self.processes.start(self.configuration.processes) if not self.daemon.drop_privileges(): self.logger.critical( 'could not drop privileges to \'%s\' refusing to run as root' % self.daemon.user, 'reactor') self.logger.critical( 'set the environmemnt value exabgp.daemon.user to change the unprivileged user', 'reactor') return self.Exit.privileges if self.early_drop: self.processes.start(self.configuration.processes) # This is required to make sure we can write in the log location as we now have dropped root privileges if not self.logger.restart(): self.logger.critical('could not setup the logger, aborting', 'reactor') return self.Exit.log if not self.daemon.savepid(): return self.Exit.pid # did we complete the run of updates caused by the last SIGUSR1/SIGUSR2 ? reload_completed = False wait = environment.settings().tcp.delay if wait: sleeptime = (wait * 60) - int(time.time()) % (wait * 60) self.logger.debug( 'waiting for %d seconds before connecting' % sleeptime, 'reactor') time.sleep(float(sleeptime)) workers = {} peers = set() while True: try: if self.signal.received: for key in self.peers: if self.peers[key].neighbor.api['signal']: self.peers[key].reactor.processes.signal( self.peers[key].neighbor, self.signal.number) signaled = self.signal.received self.signal.rearm() if signaled == Signal.SHUTDOWN: self.shutdown() break if signaled == Signal.RESTART: self.restart() continue if not reload_completed: continue if signaled == Signal.FULL_RELOAD: self._reload_processes = True if signaled in (Signal.RELOAD, Signal.FULL_RELOAD): self.load() self.processes.start(self.configuration.processes, self._reload_processes) self._reload_processes = False continue if self.listener.incoming(): # check all incoming connection self.asynchronous.schedule( str(uuid.uuid1()), 'checking for new connection(s)', self.listener.new_connections()) peers = self._active_peers() if self._completed(peers): reload_completed = True sleep = self._sleep_time # do not attempt to listen on closed sockets even if the peer is still here for io in list(workers.keys()): if io.fileno() == -1: del workers[io] # give a turn to all the peers for key in list(peers): peer = self.peers[key] action = peer.run() # .run() returns an ACTION enum: # * immediate if it wants to be called again # * later if it should be called again but has no work atm # * close if it is finished and is closing down, or restarting if action == ACTION.CLOSE: if key in self.peers: del self.peers[key] peers.discard(key) # we are loosing this peer, not point to schedule more process work elif action == ACTION.LATER: for io in peer.sockets(): workers[io] = key # no need to come back to it before a a full cycle peers.discard(key) elif action == ACTION.NOW: sleep = 0 if not peers: break # read at least on message per process if there is some and parse it for service, command in self.processes.received(): self.api.text(self, service, command) sleep = 0 self.asynchronous.run() for io in self._api_ready(list(workers), sleep): peers.add(workers[io]) del workers[io] if self._stopping and not self.peers.keys(): self._termination('exiting on peer termination', self.Exit.normal) except KeyboardInterrupt: self._termination('^C received', self.Exit.normal) except SystemExit: self._termination('exiting', self.Exit.normal) # socket.error is a subclass of IOError (so catch it first) except socket.error: self._termination('socket error received', self.Exit.socket) except IOError: self._termination( 'I/O Error received, most likely ^C during IO', self.Exit.io_error) except ProcessError: self._termination( 'Problem when sending message(s) to helper program, stopping', self.Exit.process) except select.error: self._termination('problem using select, stopping', self.Exit.select) return self.exit_code def shutdown(self): """Terminate all the current BGP connections""" self.logger.critical('performing shutdown', 'reactor') if self.listener: self.listener.stop() self.listener = None for key in self.peers.keys(): self.peers[key].shutdown() self.asynchronous.clear() self.processes.terminate() self.daemon.removepid() self._stopping = True def load(self): """Reload the configuration and send to the peer the route which changed""" self.logger.notice('performing reload of exabgp %s' % version, 'configuration') reloaded = self.configuration.reload() if not reloaded: # # Careful the string below is used but the QA code to check for sucess of failure self.logger.error( 'problem with the configuration file, no change done', 'configuration') # Careful the string above is used but the QA code to check for sucess of failure # self.logger.error(str(self.configuration.error), 'configuration') return False for key, peer in self.peers.items(): if key not in self.configuration.neighbors: self.logger.debug('removing peer: %s' % peer.neighbor.name(), 'reactor') peer.remove() for key, neighbor in self.configuration.neighbors.items(): # new peer if key not in self.peers: self.logger.debug('new peer: %s' % neighbor.name(), 'reactor') peer = Peer(neighbor, self) self.peers[key] = peer # modified peer elif self.peers[key].neighbor != neighbor: self.logger.debug( 'peer definition change, establishing a new connection for %s' % str(key), 'reactor') self.peers[key].reestablish(neighbor) # same peer but perhaps not the routes else: # finding what route changed and sending the delta is not obvious self.logger.debug( 'peer definition identical, updating peer routes if required for %s' % str(key), 'reactor') self.peers[key].reconfigure(neighbor) for ip in self._ips: if ip.afi == neighbor.peer_address.afi: self.listener.listen_on(ip, neighbor.peer_address, self._port, neighbor.md5_password, neighbor.md5_base64, None) self.logger.notice('loaded new configuration successfully', 'reactor') return True def restart(self): """Kill the BGP session and restart it""" self.logger.notice('performing restart of exabgp %s' % version, 'reactor') self.configuration.reload() for key in self.peers.keys(): if key not in self.configuration.neighbors.keys(): neighbor = self.configuration.neighbors[key] self.logger.debug('removing Peer %s' % neighbor.name(), 'reactor') self.peers[key].remove() else: self.peers[key].reestablish() self.processes.start(self.configuration.processes, True)