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._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)
