class Peer (object):
def __init__ (self, neighbor, reactor):
try:
self.logger = Logger()
# We only to try to connect via TCP once
self.once = environment.settings().tcp.once
self.bind = True if environment.settings().tcp.bind else False
except RuntimeError:
self.logger = FakeLogger()
self.once = False
self.bind = True
now = time.time()
self.reactor = reactor
self.neighbor = neighbor
# The next restart neighbor definition
self._neighbor = None
self.proto = None
self.fsm = FSM(self,FSM.IDLE)
self.stats = {
'fsm': self.fsm,
'creation': now,
'reset': now,
'complete': 0,
}
self.generator = None
# The peer should restart after a stop
self._restart = True
# The peer was restarted (to know what kind of open to send for graceful restart)
self._restarted = FORCE_GRACEFUL
# We want to remove routes which are not in the configuration anymore after a signal to reload
self._reconfigure = True
# We want to send all the known routes
self._resend_routes = SEND.DONE
# We have been asked to teardown the session with this code
self._teardown = None
self._delay = Delay()
self.recv_timer = None
def id (self):
return 'peer-%s' % self.neighbor.uid
def _reset (self, message='',error=''):
self.fsm.change(FSM.IDLE)
self.stats = {
'fsm': self.fsm,
'creation': self.stats['creation'],
'reset': time.time(),
'complete': 0,
}
if self.proto:
try:
message = u"peer reset, message [{0}] error[{1}]".format(message, error)
except UnicodeDecodeError as msg_err:
message = u"peer reset, message [{0}] error[{1}]".format(message, msg_err)
self.proto.close(message)
self._delay.increase()
self.proto = None
if not self._restart or self.neighbor.generated:
self.generator = False
return
self.generator = None
self._teardown = None
self.neighbor.rib.reset()
# If we are restarting, and the neighbor definition is different, update the neighbor
if self._neighbor:
self.neighbor = self._neighbor
self._neighbor = None
def _stop (self, message):
self.generator = None
if self.proto:
self.proto.close('stop, message [%s]' % message)
self.proto = None
# logging
def me (self, message):
return "peer %s ASN %-7s %s" % (self.neighbor.peer_address,self.neighbor.peer_as,message)
# control
def stop (self):
self._teardown = 3
self._restart = False
self._restarted = False
self._delay.reset()
self.fsm.change(FSM.IDLE)
self.stats = {
'fsm': self.fsm,
'creation': self.stats['creation'],
'reset': time.time(),
}
self.neighbor.rib.uncache()
def remove (self):
self._stop("removed")
self.stop()
def shutdown (self):
self._stop("shutting down")
self.stop()
def resend (self):
self._resend_routes = SEND.NORMAL
self._delay.reset()
def reestablish (self, restart_neighbor=None):
# we want to tear down the session and re-establish it
self._teardown = 3
self._restart = True
self._restarted = True
self._resend_routes = SEND.NORMAL
self._neighbor = restart_neighbor
self._delay.reset()
def reconfigure (self, restart_neighbor=None):
# we want to update the route which were in the configuration file
self._reconfigure = True
self._neighbor = restart_neighbor
self._resend_routes = SEND.NORMAL
self._neighbor = restart_neighbor
def teardown (self, code, restart=True):
self._restart = restart
self._teardown = code
self._delay.reset()
# sockets we must monitor
def sockets (self):
if self.proto:
fd = self.proto.fd()
if fd:
return [fd]
return []
def handle_connection (self, connection):
self.logger.debug("state machine for the peer is %s" % self.fsm.name(), self.id())
# if the other side fails, we go back to idle
if self.fsm == FSM.ESTABLISHED:
self.logger.debug('we already have a peer in state established for %s' % connection.name(),self.id())
return connection.notification(6,7,'could not accept the connection, already established')
# 6.8 The convention is to compare the BGP Identifiers of the peers
# involved in the collision and to retain only the connection initiated
# by the BGP speaker with the higher-valued BGP Identifier.
# FSM.IDLE , FSM.ACTIVE , FSM.CONNECT , FSM.OPENSENT , FSM.OPENCONFIRM , FSM.ESTABLISHED
if self.fsm == FSM.OPENCONFIRM:
# We cheat: we are not really reading the OPEN, we use the data we have instead
# it does not matter as the open message will be the same anyway
local_id = self.neighbor.router_id.pack()
remote_id = self.proto.negotiated.received_open.router_id.pack()
if remote_id < local_id:
self.logger.debug('closing incoming connection as we have an outgoing connection with higher router-id for %s' % connection.name(),self.id())
return connection.notification(6,7,'could not accept the connection, as another connection is already in open-confirm and will go through')
# accept the connection
if self.proto:
self.logger.debug('closing outgoing connection as we have another incoming on with higher router-id for %s' % connection.name(),self.id())
self.proto.close('closing outgoing connection as we have another incoming on with higher router-id')
self.proto = Protocol(self).accept(connection)
self.generator = None
# Let's make sure we do some work with this connection
self._delay.reset()
return None
def established (self):
return self.fsm == FSM.ESTABLISHED
def negotiated_families(self):
if self.proto:
families = ["%s/%s" % (x[0], x[1]) for x in self.proto.negotiated.families]
else:
families = ["%s/%s" % (x[0], x[1]) for x in self.neighbor.families()]
if len(families) > 1:
return "[ %s ]" % " ".join(families)
elif len(families) == 1:
return families[0]
return ''
def _connect (self):
proto = Protocol(self)
generator = proto.connect()
connected = False
try:
for connected in generator:
if connected:
break
if self._teardown:
raise Stop()
# we want to come back as soon as possible
yield ACTION.LATER
self.proto = proto
except Stop:
# Connection failed
if not connected and self.proto:
self.proto.close('connection to %s:%d failed' % (self.neighbor.peer_address,self.neighbor.connect))
# A connection arrived before we could establish !
if not connected or self.proto:
yield ACTION.NOW
raise Interrupted()
def _send_open (self):
message = Message.CODE.NOP
for message in self.proto.new_open():
if ordinal(message.TYPE) == Message.CODE.NOP:
yield ACTION.NOW
yield message
def _read_open (self):
wait = environment.settings().bgp.openwait
opentimer = ReceiveTimer(self.proto.connection.session,wait,1,1,'waited for open too long, we do not like stuck in active')
# Only yield if we have not the open, otherwise the reactor can run the other connection
# which would be bad as we need to do the collission check without going to the other peer
for message in self.proto.read_open(self.neighbor.peer_address.top()):
opentimer.check_ka(message)
# XXX: FIXME: change the whole code to use the ord and not the chr version
# Only yield if we have not the open, otherwise the reactor can run the other connection
# which would be bad as we need to do the collission check
if ordinal(message.TYPE) == Message.CODE.NOP:
# If a peer does not reply to OPEN message, or not enough bytes
# yielding ACTION.NOW can cause ExaBGP to busy spin trying to
# read from peer. See GH #723 .
yield ACTION.LATER
yield message
def _send_ka (self):
for message in self.proto.new_keepalive('OPENCONFIRM'):
yield ACTION.NOW
def _read_ka (self):
# Start keeping keepalive timer
for message in self.proto.read_keepalive():
self.recv_timer.check_ka_timer(message)
yield ACTION.NOW
def _establish (self):
# try to establish the outgoing connection
self.fsm.change(FSM.ACTIVE)
if not self.proto:
for action in self._connect():
if action in ACTION.ALL:
yield action
self.fsm.change(FSM.CONNECT)
# normal sending of OPEN first ...
if self.neighbor.local_as:
for sent_open in self._send_open():
if sent_open in ACTION.ALL:
yield sent_open
self.proto.negotiated.sent(sent_open)
self.fsm.change(FSM.OPENSENT)
# read the peer's open
for received_open in self._read_open():
if received_open in ACTION.ALL:
yield received_open
self.proto.negotiated.received(received_open)
self.proto.connection.msg_size = self.proto.negotiated.msg_size
# if we mirror the ASN, we need to read first and send second
if not self.neighbor.local_as:
for sent_open in self._send_open():
if sent_open in ACTION.ALL:
yield sent_open
self.proto.negotiated.sent(sent_open)
self.fsm.change(FSM.OPENSENT)
self.proto.validate_open()
self.fsm.change(FSM.OPENCONFIRM)
self.recv_timer = ReceiveTimer(self.proto.connection.session,self.proto.negotiated.holdtime,4,0)
for action in self._send_ka():
yield action
for action in self._read_ka():
yield action
self.fsm.change(FSM.ESTABLISHED)
self.stats['complete'] = time.time()
# let the caller know that we were sucesfull
yield ACTION.NOW
def _main (self):
"""yield True if we want to come back to it asap, None if nothing urgent, and False if stopped"""
if self._teardown:
raise Notify(6,3)
self.neighbor.rib.incoming.clear()
include_withdraw = False
# Announce to the process BGP is up
self.logger.notice('connected to %s with %s' % (self.id(),self.proto.connection.name()),'reactor')
self.stats['up'] = self.stats.get('up',0) + 1
if self.neighbor.api['neighbor-changes']:
try:
self.reactor.processes.up(self.neighbor)
except ProcessError:
# Can not find any better error code than 6,0 !
# XXX: We can not restart the program so this will come back again and again - FIX
# XXX: In the main loop we do exit on this kind of error
raise Notify(6,0,'ExaBGP Internal error, sorry.')
send_eor = not self.neighbor.manual_eor
new_routes = None
self._resend_routes = SEND.NORMAL
send_families = []
# Every last asm message should be re-announced on restart
for family in self.neighbor.asm:
if family in self.neighbor.families():
self.neighbor.messages.appendleft(self.neighbor.asm[family])
operational = None
refresh = None
command_eor = None
number = 0
refresh_enhanced = True if self.proto.negotiated.refresh == REFRESH.ENHANCED else False
send_ka = KA(self.proto.connection.session,self.proto)
while not self._teardown:
for message in self.proto.read_message():
self.recv_timer.check_ka(message)
if send_ka() is not False:
# we need and will send a keepalive
while send_ka() is None:
yield ACTION.NOW
# Received update
if message.TYPE == Update.TYPE:
number += 1
self.logger.debug('<< UPDATE #%d' % number,self.id())
for nlri in message.nlris:
self.neighbor.rib.incoming.update_cache(Change(nlri,message.attributes))
self.logger.debug(LazyFormat(' UPDATE #%d nlri ' % number,nlri,str),self.id())
elif message.TYPE == RouteRefresh.TYPE:
if message.reserved == RouteRefresh.request:
self._resend_routes = SEND.REFRESH
send_families.append((message.afi,message.safi))
# SEND OPERATIONAL
if self.neighbor.operational:
if not operational:
new_operational = self.neighbor.messages.popleft() if self.neighbor.messages else None
if new_operational:
operational = self.proto.new_operational(new_operational,self.proto.negotiated)
if operational:
try:
six.next(operational)
except StopIteration:
operational = None
# make sure that if some operational message are received via the API
# that we do not eat memory for nothing
elif self.neighbor.messages:
self.neighbor.messages.popleft()
# SEND REFRESH
if self.neighbor.route_refresh:
if not refresh:
new_refresh = self.neighbor.refresh.popleft() if self.neighbor.refresh else None
if new_refresh:
refresh = self.proto.new_refresh(new_refresh)
if refresh:
try:
six.next(refresh)
except StopIteration:
refresh = None
# Take the routes already sent to that peer and resend them
if self._reconfigure:
self._reconfigure = False
# we are here following a configuration change
if self._neighbor:
# see what changed in the configuration
self.neighbor.rib.outgoing.replace(self._neighbor.backup_changes,self._neighbor.changes)
# do not keep the previous routes in memory as they are not useful anymore
self._neighbor.backup_changes = []
# Take the routes already sent to that peer and resend them
if self._resend_routes != SEND.DONE:
enhanced = True if refresh_enhanced and self._resend_routes == SEND.REFRESH else False
self._resend_routes = SEND.DONE
self.neighbor.rib.outgoing.resend(send_families,enhanced)
send_families = []
# Need to send update
if not new_routes and self.neighbor.rib.outgoing.pending():
# XXX: in proto really. hum to think about ?
new_routes = self.proto.new_update(include_withdraw)
if new_routes:
try:
for _ in range(25):
# This can raise a NetworkError
six.next(new_routes)
except StopIteration:
new_routes = None
include_withdraw = True
elif send_eor:
send_eor = False
for _ in self.proto.new_eors():
yield ACTION.NOW
self.logger.debug('>> EOR(s)',self.id())
# SEND MANUAL KEEPALIVE (only if we have no more routes to send)
elif not command_eor and self.neighbor.eor:
new_eor = self.neighbor.eor.popleft()
command_eor = self.proto.new_eors(new_eor.afi,new_eor.safi)
if command_eor:
try:
six.next(command_eor)
except StopIteration:
command_eor = None
if new_routes or message.TYPE != NOP.TYPE:
yield ACTION.NOW
elif self.neighbor.messages or operational:
yield ACTION.NOW
elif self.neighbor.eor or command_eor:
yield ACTION.NOW
else:
yield ACTION.LATER
# read_message will loop until new message arrives with NOP
if self._teardown:
break
# If graceful restart, silent shutdown
if self.neighbor.graceful_restart and self.proto.negotiated.sent_open.capabilities.announced(Capability.CODE.GRACEFUL_RESTART):
self.logger.error('closing the session without notification',self.id())
self.proto.close('graceful restarted negotiated, closing without sending any notification')
raise NetworkError('closing')
# notify our peer of the shutdown
raise Notify(6,self._teardown)
def _run (self):
"""yield True if we want the reactor to give us back the hand with the same peer loop, None if we do not have any more work to do"""
try:
for action in self._establish():
yield action
for action in self._main():
yield action
# CONNECTION FAILURE
except NetworkError as network:
# we tried to connect once, it failed and it was not a manual request, we stop
if self.once and not self._teardown:
self.logger.debug('only one attempt to connect is allowed, stopping the peer',self.id())
self.stop()
self._reset('closing connection',network)
return
# NOTIFY THE PEER OF AN ERROR
except Notify as notify:
if self.proto:
try:
generator = self.proto.new_notification(notify)
try:
while True:
six.next(generator)
yield ACTION.NOW
except StopIteration:
pass
except (NetworkError,ProcessError):
self.logger.error('Notification not sent',self.id())
self._reset('notification sent (%d,%d)' % (notify.code,notify.subcode),notify)
else:
self._reset()
return
# THE PEER NOTIFIED US OF AN ERROR
except Notification as notification:
# we tried to connect once, it failed and it was not a manual request, we stop
if self.once and not self._teardown:
self.logger.debug('only one attempt to connect is allowed, stopping the peer',self.id())
self.stop()
self._reset(
'notification received (%d,%d)' % (
notification.code,
notification.subcode),
notification
)
return
# RECEIVED a Message TYPE we did not expect
except Message as message:
self._reset('unexpected message received',message)
return
# PROBLEM WRITING TO OUR FORKED PROCESSES
except ProcessError as process:
self._reset('process problem',process)
return
# ....
except Interrupted as interruption:
self._reset('connection received before we could fully establish one')
return
# UNHANDLED PROBLEMS
except Exception as exc:
# Those messages can not be filtered in purpose
self.logger.debug('\n'.join([
NO_PANIC,
'',
'',
str(type(exc)),
str(exc),
trace(),
FOOTER
]),'reactor')
self._reset()
return
# loop
def run (self):
if self.reactor.processes.broken(self.neighbor):
# XXX: we should perhaps try to restart the process ??
self.logger.error('ExaBGP lost the helper process for this peer - stopping','process')
if self.reactor.processes.terminate_on_error:
self.reactor.api_shutdown()
else:
self.stop()
return True
if self.generator:
try:
# This generator only stops when it raises
# otherwise return one of the ACTION
return six.next(self.generator)
except StopIteration:
# Trying to run a closed loop, no point continuing
self.generator = None
if self._restart:
return ACTION.LATER
return ACTION.CLOSE
elif self.generator is None:
if self.fsm in [FSM.OPENCONFIRM,FSM.ESTABLISHED]:
self.logger.debug('stopping, other connection is established',self.id())
self.generator = False
return ACTION.LATER
if self._delay.backoff():
return ACTION.LATER
if self._restart:
self.logger.debug('initialising connection to %s' % self.id(),'reactor')
self.generator = self._run()
return ACTION.LATER # make sure we go through a clean loop
return ACTION.CLOSE
def cli_data (self):
def tri (value):
if value is None:
return None
return True if value else False
peer = defaultdict(lambda: None)
have_peer = self.proto is not None
have_open = self.proto and self.proto.negotiated.received_open
if have_peer:
peer.update({
'multi-session': self.proto.negotiated.multisession,
'operational': self.proto.negotiated.operational,
})
if have_open:
capa = self.proto.negotiated.received_open.capabilities
peer.update({
'router-id': self.proto.negotiated.received_open.router_id,
'hold-time': self.proto.negotiated.received_open.hold_time,
'asn4': self.proto.negotiated.asn4,
'route-refresh': capa.announced(Capability.CODE.ROUTE_REFRESH),
'multi-session': capa.announced(Capability.CODE.MULTISESSION) or capa.announced(Capability.CODE.MULTISESSION_CISCO),
'add-path': capa.announced(Capability.CODE.ADD_PATH),
'extended-message': capa.announced(Capability.CODE.EXTENDED_MESSAGE),
'graceful-restart': capa.announced(Capability.CODE.GRACEFUL_RESTART),
})
capabilities = {
'asn4': (tri(self.neighbor.asn4), tri(peer['asn4'])),
'route-refresh': (tri(self.neighbor.route_refresh),tri(peer['route-refresh'])),
'multi-session': (tri(self.neighbor.multisession), tri(peer['multi-session'])),
'operational': (tri(self.neighbor.operational), tri(peer['operational'])),
'add-path': (tri(self.neighbor.add_path),tri(peer['add-path'])),
'extended-message': (tri(self.neighbor.extended_message),tri(peer['extended-message'])),
'graceful-restart': (tri(self.neighbor.graceful_restart),tri(peer['graceful-restart'])),
}
families = {}
for family in self.neighbor.families():
if have_open:
common = True if family in self.proto.negotiated.families else False
addpath = self.proto.negotiated.addpath.receive(*family) and self.proto.negotiated.addpath.receive(*family)
else:
common = None
addpath = None if family in self.neighbor.addpaths() else False
families[family] = (True,common,addpath)
messages = {}
total_sent = 0
total_rcvd = 0
for message in ('open','notification','keepalive','update','refresh'):
sent = self.stats.get('send-%s' % message,0)
rcvd = self.stats.get('receive-%s' % message,0)
total_sent += sent
total_rcvd += rcvd
messages[message] = (sent, rcvd)
messages['total'] = (total_sent, total_rcvd)
return {
'down': int(self.stats['reset'] - self.stats['creation']),
'duration': int(time.time() - self.stats['complete']) if self.stats['complete'] else 0,
'local-address': str(self.neighbor.local_address),
'peer-address': str(self.neighbor.peer_address),
'local-as': int(self.neighbor.local_as),
'peer-as': int(self.neighbor.peer_as),
'local-id': str(self.neighbor.router_id),
'peer-id': None if peer['peer-id'] is None else str(peer['router-id']),
'local-hold': int(self.neighbor.hold_time),
'peer-hold': None if peer['hold-time'] is None else int(peer['hold-time']),
'state': self.fsm.name(),
'capabilities': capabilities,
'families': families,
'messages': messages,
}
class Connection(object):
direction = 'undefined'
identifier = {}
def __init__(self, afi, peer, local):
self.msg_size = ExtendedMessage.INITIAL_SIZE
# peer and local are strings of the IP
try:
self.defensive = environment.settings().debug.defensive
self.logger = Logger()
except RuntimeError:
self.defensive = True
self.logger = FakeLogger()
self.afi = afi
self.peer = peer
self.local = local
self.io = None
self.established = False
self._rpoller = {}
self._wpoller = {}
self.id = self.identifier.get(self.direction, 1)
def success(self):
identifier = self.identifier.get(self.direction, 1) + 1
self.identifier[self.direction] = identifier
return identifier
# Just in case ..
def __del__(self):
if self.io:
self.close()
self.logger.warning('connection to %s closed' % self.peer,
self.session())
def name(self):
return "%s-%d %s-%s" % (self.direction, self.id, self.local, self.peer)
def session(self):
return "%s-%d" % (self.direction, self.id)
def fd(self):
if self.io:
return self.io.fileno()
# the socket is closed (fileno() == -1) or not open yet (io is None)
return -1
def close(self):
try:
self.logger.warning('%s, closing connection' % self.name(),
source=self.session())
if self.io:
self.io.close()
self.io = None
except KeyboardInterrupt as exc:
raise exc
except Exception:
self.io = None
def reading(self):
poller = self._rpoller.get(self.io, None)
if poller is None:
poller = select.poll()
poller.register(
self.io, select.POLLIN | select.POLLPRI | select.POLLHUP
| select.POLLNVAL | select.POLLERR)
self._rpoller = {self.io: poller}
ready = False
for _, event in poller.poll(0):
if event & select.POLLIN or event & select.POLLPRI:
ready = True
elif event & select.POLLHUP or event & select.POLLERR or event & select.POLLNVAL:
self._rpoller = {}
ready = True
return ready
def writing(self):
poller = self._wpoller.get(self.io, None)
if poller is None:
poller = select.poll()
poller.register(
self.io, select.POLLOUT | select.POLLHUP | select.POLLNVAL
| select.POLLERR)
self._wpoller = {self.io: poller}
ready = False
for _, event in poller.poll(0):
if event & select.POLLOUT:
ready = True
elif event & select.POLLHUP or event & select.POLLERR or event & select.POLLNVAL:
self._wpoller = {}
ready = True
return ready
def _reader(self, number):
# The function must not be called if it does not return with no data with a smaller size as parameter
if not self.io:
self.close()
raise NotConnected('Trying to read on a closed TCP connection')
if number == 0:
yield b''
return
while not self.reading():
yield b''
data = b''
reported = ''
while True:
try:
while True:
if self.defensive and random.randint(0, 2):
raise socket.error(errno.EAGAIN,
'raising network error on purpose')
read = self.io.recv(number)
if not read:
self.close()
self.logger.warning(
'%s %s lost TCP session with peer' %
(self.name(), self.peer), self.session())
raise LostConnection(
'the TCP connection was closed by the remote end')
data += read
number -= len(read)
if not number:
self.logger.debug(
LazyFormat('received TCP payload', data),
self.session())
yield data
return
yield b''
except socket.timeout as exc:
self.close()
self.logger.warning(
'%s %s peer is too slow' % (self.name(), self.peer),
self.session())
raise TooSlowError(
'Timeout while reading data from the network (%s)' %
errstr(exc))
except socket.error as exc:
if exc.args[0] in error.block:
message = '%s %s blocking io problem mid-way through reading a message %s, trying to complete' % (
self.name(), self.peer, errstr(exc))
if message != reported:
reported = message
self.logger.debug(message, self.session())
yield b''
elif exc.args[0] in error.fatal:
self.close()
raise LostConnection('issue reading on the socket: %s' %
errstr(exc))
# what error could it be !
else:
self.logger.critical(
'%s %s undefined error reading on socket' %
(self.name(), self.peer), self.session())
raise NetworkError(
'Problem while reading data from the network (%s)' %
errstr(exc))
def writer(self, data):
if not self.io:
# XXX: FIXME: Make sure it does not hold the cleanup during the closing of the peering session
yield True
return
while not self.writing():
yield False
self.logger.debug(LazyFormat('sending TCP payload', data),
self.session())
# The first while is here to setup the try/catch block once as it is very expensive
while True:
try:
while True:
if self.defensive and random.randint(0, 2):
raise socket.error(errno.EAGAIN,
'raising network error on purpose')
# we can not use sendall as in case of network buffer filling
# it does raise and does not let you know how much was sent
number = self.io.send(data)
if not number:
self.close()
self.logger.warning(
'%s %s lost TCP connection with peer' %
(self.name(), self.peer), self.session())
raise LostConnection('lost the TCP connection')
data = data[number:]
if not data:
yield True
return
yield False
except socket.error as exc:
if exc.args[0] in error.block:
self.logger.debug(
'%s %s blocking io problem mid-way through writing a message %s, trying to complete'
% (self.name(), self.peer, errstr(exc)),
self.session())
yield False
elif exc.errno == errno.EPIPE:
# The TCP connection is gone.
self.close()
raise NetworkError('Broken TCP connection')
elif exc.args[0] in error.fatal:
self.close()
self.logger.critical(
'%s %s problem sending message (%s)' %
(self.name(), self.peer, errstr(exc)), self.session())
raise NetworkError(
'Problem while writing data to the network (%s)' %
errstr(exc))
# what error could it be !
else:
self.logger.critical(
'%s %s undefined error writing on socket' %
(self.name(), self.peer), self.session())
yield False
def reader(self):
# _reader returns the whole number requested or nothing and then stops
for header in self._reader(Message.HEADER_LEN):
if not header:
yield 0, 0, b'', b'', None
if not header.startswith(Message.MARKER):
report = 'The packet received does not contain a BGP marker'
yield 0, 0, header, b'', NotifyError(1, 1, report)
return
msg = ordinal(header[18])
length = unpack('!H', header[16:18])[0]
if length < Message.HEADER_LEN or length > self.msg_size:
report = '%s has an invalid message length of %d' % (
Message.CODE.name(msg), length)
yield length, 0, header, b'', NotifyError(1, 2, report)
return
validator = Message.Length.get(msg, lambda _: _ >= 19)
if not validator(length):
# MUST send the faulty length back
report = '%s has an invalid message length of %d' % (
Message.CODE.name(msg), length)
yield length, 0, header, b'', NotifyError(1, 2, report)
return
number = length - Message.HEADER_LEN
if not number:
yield length, msg, header, b'', None
return
for body in self._reader(number):
if not body:
yield 0, 0, b'', b'', None
yield length, msg, header, body, None
class Peer(object):
def __init__(self, neighbor, reactor):
try:
self.logger = Logger()
# We only to try to connect via TCP once
self.once = environment.settings().tcp.once
self.bind = True if environment.settings().tcp.bind else False
except RuntimeError:
self.logger = FakeLogger()
self.once = False
self.bind = True
now = time.time()
self.reactor = reactor
self.neighbor = neighbor
# The next restart neighbor definition
self._neighbor = None
self.proto = None
self.fsm = FSM(self, FSM.IDLE)
self.stats = {
'fsm': self.fsm,
'creation': now,
'complete': now,
}
self.generator = None
# The peer should restart after a stop
self._restart = True
# The peer was restarted (to know what kind of open to send for graceful restart)
self._restarted = FORCE_GRACEFUL
# We want to remove routes which are not in the configuration anymote afte a signal to reload
self._reconfigure = True
# We want to send all the known routes
self._resend_routes = SEND.DONE
# We have been asked to teardown the session with this code
self._teardown = None
self._delay = Delay()
self.recv_timer = None
def id(self):
return 'peer-%s' % self.neighbor.uid
def _reset(self, message='', error=''):
self.fsm.change(FSM.IDLE)
self.stats = {
'fsm': self.fsm,
'creation': self.stats['creation'],
'complete': self.stats['creation'],
}
if self.proto:
self.proto.close(u"peer reset, message [{0}] error[{1}]".format(
message, error))
self._delay.increase()
self.proto = None
if not self._restart or self.neighbor.generated:
self.generator = False
return
self.generator = None
self._teardown = None
self.neighbor.rib.reset()
# If we are restarting, and the neighbor definition is different, update the neighbor
if self._neighbor:
self.neighbor = self._neighbor
self._neighbor = None
def _stop(self, message):
self.generator = False
self.proto.close('stop, message [%s]' % message)
self.proto = None
# logging
def me(self, message):
return "peer %s ASN %-7s %s" % (self.neighbor.peer_address,
self.neighbor.peer_as, message)
# control
def stop(self):
self._teardown = 3
self._restart = False
self._restarted = False
self._delay.reset()
self.fsm.change(FSM.IDLE)
self.stats = {
'fsm': self.fsm,
'creation': self.stats['creation'],
'reset': time.time(),
}
self.neighbor.rib.uncache()
def resend(self):
self._resend_routes = SEND.NORMAL
self._delay.reset()
def reestablish(self, restart_neighbor=None):
# we want to tear down the session and re-establish it
self._teardown = 3
self._restart = True
self._restarted = True
self._resend_routes = SEND.NORMAL
self._neighbor = restart_neighbor
self._delay.reset()
def reconfigure(self, restart_neighbor=None):
# we want to update the route which were in the configuration file
self._reconfigure = True
self._neighbor = restart_neighbor
self._resend_routes = SEND.NORMAL
self._neighbor = restart_neighbor
def teardown(self, code, restart=True):
self._restart = restart
self._teardown = code
self._delay.reset()
# sockets we must monitor
def sockets(self):
ios = []
if self.proto and self.proto.connection and self.proto.connection.io:
ios.append(self.proto.connection.io)
return ios
def handle_connection(self, connection):
# if the other side fails, we go back to idle
if self.fsm == FSM.ESTABLISHED:
self.logger.debug(
'we already have a peer in state established for %s' %
connection.name(), self.id())
return connection.notification(
6, 7, b'could not accept the connection, already established')
# 6.8 The convention is to compare the BGP Identifiers of the peers
# involved in the collision and to retain only the connection initiated
# by the BGP speaker with the higher-valued BGP Identifier.
# FSM.IDLE , FSM.ACTIVE , FSM.CONNECT , FSM.OPENSENT , FSM.OPENCONFIRM , FSM.ESTABLISHED
if self.fsm == FSM.OPENCONFIRM:
# We cheat: we are not really reading the OPEN, we use the data we have instead
# it does not matter as the open message will be the same anyway
local_id = self.neighbor.router_id.pack()
remote_id = self.proto.negotiated.received_open.router_id.pack()
if remote_id < local_id:
self.logger.debug(
'closing incoming connection as we have an outgoing connection with higher router-id for %s'
% connection.name(), self.id())
return connection.notification(
6, 7,
b'could not accept the connection, as another connection is already in open-confirm and will go through'
)
# accept the connection
if self.proto:
self.proto.close(
'closing outgoing connection as we have another incoming on with higher router-id'
)
self.proto = Protocol(self).accept(connection)
self.generator = None
# Let's make sure we do some work with this connection
self._delay.reset()
return None
def established(self):
return self.fsm == FSM.ESTABLISHED
def negotiated_families(self):
if self.proto:
families = [
"%s/%s" % (x[0], x[1]) for x in self.proto.negotiated.families
]
else:
families = [
"%s/%s" % (x[0], x[1]) for x in self.neighbor.families()
]
if len(families) > 1:
return "[ %s ]" % " ".join(families)
elif len(families) == 1:
return families[0]
return ''
def _connect(self):
proto = Protocol(self)
generator = proto.connect()
connected = False
try:
while not connected:
if self._teardown:
raise StopIteration()
connected = six.next(generator)
# we want to come back as soon as possible
yield ACTION.LATER
self.proto = proto
except StopIteration:
# Connection failed
if not connected and self.proto:
self.proto.close(
'connection to %s:%d failed' %
(self.neighbor.peer_address, self.neighbor.connect))
# A connection arrived before we could establish !
if not connected or self.proto:
yield ACTION.NOW
raise Interrupted()
def _send_open(self):
message = Message.CODE.NOP
for message in self.proto.new_open():
if ordinal(message.TYPE) == Message.CODE.NOP:
yield ACTION.NOW
yield message
def _read_open(self):
wait = environment.settings().bgp.openwait
opentimer = ReceiveTimer(
self.proto.connection.session, wait, 1, 1,
'waited for open too long, we do not like stuck in active')
# Only yield if we have not the open, otherwise the reactor can run the other connection
# which would be bad as we need to do the collission check without going to the other peer
for message in self.proto.read_open(self.neighbor.peer_address.top()):
opentimer.check_ka(message)
# XXX: FIXME: change the whole code to use the ord and not the chr version
# Only yield if we have not the open, otherwise the reactor can run the other connection
# which would be bad as we need to do the collission check
if ordinal(message.TYPE) == Message.CODE.NOP:
# If a peer does not reply to OPEN message, or not enough bytes
# yielding ACTION.NOW can cause ExaBGP to busy spin trying to
# read from peer. See GH #723 .
yield ACTION.LATER
yield message
def _send_ka(self):
for message in self.proto.new_keepalive('OPENCONFIRM'):
yield ACTION.NOW
def _read_ka(self):
# Start keeping keepalive timer
for message in self.proto.read_keepalive():
self.recv_timer.check_ka_timer(message)
yield ACTION.NOW
def _establish(self):
# try to establish the outgoing connection
self.fsm.change(FSM.ACTIVE)
if not self.proto:
for action in self._connect():
if action in ACTION.ALL:
yield action
self.fsm.change(FSM.CONNECT)
# normal sending of OPEN first ...
if self.neighbor.local_as:
for sent_open in self._send_open():
if sent_open in ACTION.ALL:
yield sent_open
self.proto.negotiated.sent(sent_open)
self.fsm.change(FSM.OPENSENT)
# read the peer's open
for received_open in self._read_open():
if received_open in ACTION.ALL:
yield received_open
self.proto.negotiated.received(received_open)
self.proto.connection.msg_size = self.proto.negotiated.msg_size
# if we mirror the ASN, we need to read first and send second
if not self.neighbor.local_as:
for sent_open in self._send_open():
if sent_open in ACTION.ALL:
yield sent_open
self.proto.negotiated.sent(sent_open)
self.fsm.change(FSM.OPENSENT)
self.proto.validate_open()
self.fsm.change(FSM.OPENCONFIRM)
self.recv_timer = ReceiveTimer(self.proto.connection.session,
self.proto.negotiated.holdtime, 4, 0)
for action in self._send_ka():
yield action
for action in self._read_ka():
yield action
self.fsm.change(FSM.ESTABLISHED)
self.stats['complete'] = time.time()
# let the caller know that we were sucesfull
yield ACTION.NOW
def _main(self):
"""yield True if we want to come back to it asap, None if nothing urgent, and False if stopped"""
if self._teardown:
raise Notify(6, 3)
self.neighbor.rib.incoming.clear()
include_withdraw = False
# Announce to the process BGP is up
self.logger.notice(
'connected to %s with %s' %
(self.id(), self.proto.connection.name()), 'reactor')
self.stats['up'] = self.stats.get('up', 0) + 1
if self.neighbor.api['neighbor-changes']:
try:
self.reactor.processes.up(self.neighbor)
except ProcessError:
# Can not find any better error code than 6,0 !
# XXX: We can not restart the program so this will come back again and again - FIX
# XXX: In the main loop we do exit on this kind of error
raise Notify(6, 0, 'ExaBGP Internal error, sorry.')
send_eor = not self.neighbor.manual_eor
new_routes = None
self._resend_routes = SEND.NORMAL
send_families = []
# Every last asm message should be re-announced on restart
for family in self.neighbor.asm:
if family in self.neighbor.families():
self.neighbor.messages.appendleft(self.neighbor.asm[family])
operational = None
refresh = None
command_eor = None
number = 0
refresh_enhanced = True if self.proto.negotiated.refresh == REFRESH.ENHANCED else False
send_ka = KA(self.proto.connection.session, self.proto)
while not self._teardown:
for message in self.proto.read_message():
self.recv_timer.check_ka(message)
if send_ka() is not False:
# we need and will send a keepalive
while send_ka() is None:
yield ACTION.NOW
# Received update
if message.TYPE == Update.TYPE:
number += 1
self.logger.debug('<< UPDATE #%d' % number, self.id())
for nlri in message.nlris:
self.neighbor.rib.incoming.update_cache(
Change(nlri, message.attributes))
self.logger.debug(
LazyFormat(' UPDATE #%d nlri ' % number, nlri,
str), self.id())
elif message.TYPE == RouteRefresh.TYPE:
if message.reserved == RouteRefresh.request:
self._resend_routes = SEND.REFRESH
send_families.append((message.afi, message.safi))
# SEND OPERATIONAL
if self.neighbor.operational:
if not operational:
new_operational = self.neighbor.messages.popleft(
) if self.neighbor.messages else None
if new_operational:
operational = self.proto.new_operational(
new_operational, self.proto.negotiated)
if operational:
try:
six.next(operational)
except StopIteration:
operational = None
# make sure that if some operational message are received via the API
# that we do not eat memory for nothing
elif self.neighbor.messages:
self.neighbor.messages.popleft()
# SEND REFRESH
if self.neighbor.route_refresh:
if not refresh:
new_refresh = self.neighbor.refresh.popleft(
) if self.neighbor.refresh else None
if new_refresh:
refresh = self.proto.new_refresh(new_refresh)
if refresh:
try:
six.next(refresh)
except StopIteration:
refresh = None
# Take the routes already sent to that peer and resend them
if self._reconfigure:
self._reconfigure = False
# we are here following a configuration change
if self._neighbor:
# see what changed in the configuration
self.neighbor.rib.outgoing.replace(
self._neighbor.backup_changes,
self._neighbor.changes)
# do not keep the previous routes in memory as they are not useful anymore
self._neighbor.backup_changes = []
# Take the routes already sent to that peer and resend them
if self._resend_routes != SEND.DONE:
enhanced = True if refresh_enhanced and self._resend_routes == SEND.REFRESH else False
self._resend_routes = SEND.DONE
self.neighbor.rib.outgoing.resend(send_families, enhanced)
send_families = []
# Need to send update
if not new_routes and self.neighbor.rib.outgoing.pending():
# XXX: in proto really. hum to think about ?
new_routes = self.proto.new_update(include_withdraw)
if new_routes:
try:
for _ in range(25):
# This can raise a NetworkError
six.next(new_routes)
except StopIteration:
new_routes = None
include_withdraw = True
elif send_eor:
send_eor = False
for _ in self.proto.new_eors():
yield ACTION.NOW
self.logger.debug('>> EOR(s)', self.id())
# SEND MANUAL KEEPALIVE (only if we have no more routes to send)
elif not command_eor and self.neighbor.eor:
new_eor = self.neighbor.eor.popleft()
command_eor = self.proto.new_eors(new_eor.afi,
new_eor.safi)
if command_eor:
try:
six.next(command_eor)
except StopIteration:
command_eor = None
if new_routes or message.TYPE != NOP.TYPE:
yield ACTION.NOW
elif self.neighbor.messages or operational:
yield ACTION.NOW
elif self.neighbor.eor or command_eor:
yield ACTION.NOW
else:
yield ACTION.LATER
# read_message will loop until new message arrives with NOP
if self._teardown:
break
# If graceful restart, silent shutdown
if self.neighbor.graceful_restart and self.proto.negotiated.sent_open.capabilities.announced(
Capability.CODE.GRACEFUL_RESTART):
self.logger.error('closing the session without notification',
self.id())
self.proto.close(
'graceful restarted negotiated, closing without sending any notification'
)
raise NetworkError('closing')
# notify our peer of the shutdown
raise Notify(6, self._teardown)
def _run(self):
"""yield True if we want the reactor to give us back the hand with the same peer loop, None if we do not have any more work to do"""
try:
for action in self._establish():
yield action
for action in self._main():
yield action
# CONNECTION FAILURE
except NetworkError as network:
# we tried to connect once, it failed and it was not a manual request, we stop
if self.once and not self._teardown:
self.logger.debug(
'only one attempt to connect is allowed, stopping the peer',
self.id())
self.stop()
self._reset('closing connection', network)
return
# NOTIFY THE PEER OF AN ERROR
except Notify as notify:
if self.proto:
try:
generator = self.proto.new_notification(notify)
try:
while True:
six.next(generator)
yield ACTION.NOW
except StopIteration:
pass
except (NetworkError, ProcessError):
self.logger.error('Notification not sent', self.id())
self._reset(
'notification sent (%d,%d)' %
(notify.code, notify.subcode), notify)
else:
self._reset()
return
# THE PEER NOTIFIED US OF AN ERROR
except Notification as notification:
# we tried to connect once, it failed and it was not a manual request, we stop
if self.once and not self._teardown:
self.logger.debug(
'only one attempt to connect is allowed, stopping the peer',
self.id())
self.stop()
self._reset(
'notification received (%d,%d)' %
(notification.code, notification.subcode), notification)
return
# RECEIVED a Message TYPE we did not expect
except Message as message:
self._reset('unexpected message received', message)
return
# PROBLEM WRITING TO OUR FORKED PROCESSES
except ProcessError as process:
self._reset('process problem', process)
return
# ....
except Interrupted as interruption:
self._reset(
'connection received before we could fully establish one')
return
# UNHANDLED PROBLEMS
except Exception as exc:
# Those messages can not be filtered in purpose
self.logger.debug(
'\n'.join([
NO_PANIC, '', '',
str(type(exc)),
str(exc),
trace(), FOOTER
]), 'reactor')
self._reset()
return
# loop
def run(self):
if self.reactor.processes.broken(self.neighbor):
# XXX: we should perhaps try to restart the process ??
self.logger.error(
'ExaBGP lost the helper process for this peer - stopping',
'process')
if self.reactor.processes.terminate_on_error:
self.reactor.api_shutdown()
else:
self.stop()
return True
if self.generator:
try:
# This generator only stops when it raises
# otherwise return one of the ACTION
return six.next(self.generator)
except StopIteration:
# Trying to run a closed loop, no point continuing
self.generator = None
if self._restart:
return ACTION.LATER
return ACTION.CLOSE
elif self.generator is None:
if self.fsm in [FSM.OPENCONFIRM, FSM.ESTABLISHED]:
self.logger.debug('stopping, other connection is established',
self.id())
self.generator = False
return ACTION.LATER
if self._delay.backoff():
return ACTION.LATER
if self._restart:
self.logger.debug('initialising connection to %s' % self.id(),
'reactor')
self.generator = self._run()
return ACTION.LATER # make sure we go through a clean loop
return ACTION.CLOSE
def cli_data(self):
def tri(value):
if value is None:
return None
return True if value else False
peer = defaultdict(lambda: None)
have_peer = self.proto is not None
have_open = self.proto and self.proto.negotiated.received_open
if have_peer:
peer.update({
'multi-session': self.proto.negotiated.multisession,
'operational': self.proto.negotiated.operational,
})
if have_open:
capa = self.proto.negotiated.received_open.capabilities
peer.update({
'router-id':
self.proto.negotiated.received_open.router_id,
'hold-time':
self.proto.negotiated.received_open.hold_time,
'asn4':
self.proto.negotiated.asn4,
'route-refresh':
capa.announced(Capability.CODE.ROUTE_REFRESH),
'multi-session':
capa.announced(Capability.CODE.MULTISESSION)
or capa.announced(Capability.CODE.MULTISESSION_CISCO),
'add-path':
capa.announced(Capability.CODE.ADD_PATH),
'extended-message':
capa.announced(Capability.CODE.EXTENDED_MESSAGE),
'graceful-restart':
capa.announced(Capability.CODE.GRACEFUL_RESTART),
})
capabilities = {
'asn4': (tri(self.neighbor.asn4), tri(peer['asn4'])),
'route-refresh':
(tri(self.neighbor.route_refresh), tri(peer['route-refresh'])),
'multi-session':
(tri(self.neighbor.multisession), tri(peer['multi-session'])),
'operational': (tri(self.neighbor.operational),
tri(peer['operational'])),
'add-path': (tri(self.neighbor.add_path), tri(peer['add-path'])),
'extended-message': (tri(self.neighbor.extended_message),
tri(peer['extended-message'])),
'graceful-restart': (tri(self.neighbor.graceful_restart),
tri(peer['graceful-restart'])),
}
families = {}
for family in self.neighbor.families():
if have_open:
common = True if family in self.proto.negotiated.families else False
addpath = self.proto.negotiated.addpath.receive(
*family) and self.proto.negotiated.addpath.receive(*family)
else:
common = None
addpath = None if family in self.neighbor.addpaths() else False
families[family] = (True, common, addpath)
messages = {}
total_sent = 0
total_rcvd = 0
for message in ('open', 'notification', 'keepalive', 'update',
'refresh'):
sent = self.stats.get('send-%s' % message, 0)
rcvd = self.stats.get('receive-%s' % message, 0)
total_sent += sent
total_rcvd += rcvd
messages[message] = (sent, rcvd)
messages['total'] = (total_sent, total_rcvd)
return {
'duration':
int(time.time() -
self.stats['complete']) if self.stats['complete'] else 0,
'local-address':
str(self.neighbor.local_address),
'peer-address':
str(self.neighbor.peer_address),
'local-as':
int(self.neighbor.local_as),
'peer-as':
int(self.neighbor.peer_as),
'local-id':
str(self.neighbor.router_id),
'peer-id':
None if peer['peer-id'] is None else str(peer['router-id']),
'local-hold':
int(self.neighbor.hold_time),
'peer-hold':
None if peer['hold-time'] is None else int(peer['hold-time']),
'state':
self.fsm.name(),
'capabilities':
capabilities,
'families':
families,
'messages':
messages,
}
class Protocol(object):
decode = True
def __init__(self, peer):
try:
self.logger = Logger()
except RuntimeError:
self.logger = FakeLogger()
self.peer = peer
self.neighbor = peer.neighbor
self.negotiated = Negotiated(self.neighbor)
self.connection = None
if self.neighbor.connect:
self.port = self.neighbor.connect
elif os.environ.get('exabgp.tcp.port', '').isdigit():
self.port = int(os.environ.get('exabgp.tcp.port'))
elif os.environ.get('exabgp_tcp_port', '').isdigit():
self.port = int(os.environ.get('exabgp_tcp_port'))
else:
self.port = 179
from exabgp.configuration.environment import environment
self.log_routes = peer.neighbor.adj_rib_in or environment.settings(
).log.routes
def fd(self):
if self.connection is None:
return None
return self.connection.fd()
# XXX: we use self.peer.neighbor.peer_address when we could use self.neighbor.peer_address
def me(self, message):
return "%s/%s %s" % (self.peer.neighbor.peer_address,
self.peer.neighbor.peer_as, message)
def accept(self, incoming):
self.connection = incoming
if self.peer.neighbor.api['neighbor-changes']:
self.peer.reactor.processes.connected(self.peer.neighbor)
# very important - as we use this function on __init__
return self
def connect(self):
# allows to test the protocol code using modified StringIO with a extra 'pending' function
if not self.connection:
local = self.neighbor.md5_ip.top(
) if not self.neighbor.auto_discovery else None
peer = self.neighbor.peer_address.top()
afi = self.neighbor.peer_address.afi
md5 = self.neighbor.md5_password
md5_base64 = self.neighbor.md5_base64
ttl_out = self.neighbor.ttl_out
self.connection = Outgoing(afi, peer, local, self.port, md5,
md5_base64, ttl_out)
if not self.connection.init:
yield False
return
if not local:
self.neighbor.local_address = IP.create(self.connection.local)
if self.neighbor.router_id is None and self.neighbor.local_address.afi == AFI.ipv4:
self.neighbor.router_id = self.neighbor.local_address
for connected in self.connection.establish():
if not connected:
yield False
continue
if self.peer.neighbor.api['neighbor-changes']:
self.peer.reactor.processes.connected(self.peer.neighbor)
yield True
return
def close(self, reason='protocol closed, reason unspecified'):
if self.connection:
self.logger.debug(reason, self.connection.session())
# must be first otherwise we could have a loop caused by the raise in the below
self.connection.close()
self.connection = None
self.peer.stats['down'] = self.peer.stats.get('down', 0) + 1
try:
if self.peer.neighbor.api['neighbor-changes']:
self.peer.reactor.processes.down(self.peer.neighbor,
reason)
except ProcessError:
self.logger.debug(
'could not send notification of neighbor close to API',
self.connection.session())
def _to_api(self, direction, message, raw):
packets = self.neighbor.api['%s-packets' % direction]
parsed = self.neighbor.api['%s-parsed' % direction]
consolidate = self.neighbor.api['%s-consolidate' % direction]
negotiated = self.negotiated if self.neighbor.api[
'negotiated'] else None
if consolidate:
if packets:
self.peer.reactor.processes.message(self.peer.neighbor,
direction, message,
negotiated, raw[:19],
raw[19:])
else:
self.peer.reactor.processes.message(self.peer.neighbor,
direction, message,
negotiated, b'', b'')
else:
if packets:
self.peer.reactor.processes.packets(self.peer.neighbor,
direction, int(message.ID),
negotiated, raw[:19],
raw[19:])
if parsed:
self.peer.reactor.processes.message(message.ID,
self.peer.neighbor,
direction, message,
negotiated, b'', b'')
def write(self, message, negotiated=None):
raw = message.message(negotiated)
code = 'send-%s' % Message.CODE.short(message.ID)
self.peer.stats[code] = self.peer.stats.get(code, 0) + 1
if self.neighbor.api.get(code, False):
self._to_api('send', message, raw)
for boolean in self.connection.writer(raw):
yield boolean
def send(self, raw):
code = 'send-%s' % Message.CODE.short(ordinal(raw[18]))
self.peer.stats[code] = self.peer.stats.get(code, 0) + 1
if self.neighbor.api.get(code, False):
message = Update.unpack_message(raw[19:], self.negotiated)
self._to_api('send', message, raw)
for boolean in self.connection.writer(raw):
yield boolean
# Read from network .......................................................
def read_message(self):
# This will always be defined by the loop but scope leaking upset scrutinizer/pylint
msg_id = None
packets = self.neighbor.api['receive-packets']
consolidate = self.neighbor.api['receive-consolidate']
parsed = self.neighbor.api['receive-parsed']
body, header = b'', b'' # just because pylint/pylama are getting more clever
for length, msg_id, header, body, notify in self.connection.reader():
# internal issue
if notify:
code = 'receive-%s' % Message.CODE.NOTIFICATION.SHORT
if self.neighbor.api.get(code, False):
if consolidate:
self.peer.reactor.processes.notification(
self.peer.neighbor, 'receive', notify.code,
notify.subcode, str(notify), None, header, body)
elif parsed:
self.peer.reactor.processes.notification(
self.peer.neighbor, 'receive', notify.code,
notify.subcode, str(notify), None, b'', b'')
elif packets:
self.peer.reactor.processes.packets(
self.peer.neighbor, 'receive', msg_id, None,
header, body)
# XXX: is notify not already Notify class ?
raise Notify(notify.code, notify.subcode, str(notify))
if not length:
yield _NOP
continue
self.logger.debug(
'<< message of type %s' % Message.CODE.name(msg_id),
self.connection.session())
code = 'receive-%s' % Message.CODE.short(msg_id)
self.peer.stats[code] = self.peer.stats.get(code, 0) + 1
for_api = self.neighbor.api.get(code, False)
if for_api and packets and not consolidate:
negotiated = self.negotiated if self.neighbor.api.get(
'negotiated', False) else None
self.peer.reactor.processes.packets(self.peer.neighbor,
'receive', msg_id,
negotiated, header, body)
if msg_id == Message.CODE.UPDATE:
if not self.neighbor.adj_rib_in and not (
for_api or self.log_routes) and not (parsed
or consolidate):
yield _UPDATE
return
try:
message = Message.unpack(msg_id, body, self.negotiated)
except (KeyboardInterrupt, SystemExit, Notify):
raise
except Exception as exc:
self.logger.debug('could not decode message "%d"' % msg_id,
self.connection.session())
self.logger.debug('%s' % str(exc), self.connection.session())
self.logger.debug(traceback.format_exc(),
self.connection.session())
raise Notify(
1, 0,
'can not decode update message of type "%d"' % msg_id)
# raise Notify(5,0,'unknown message received')
if message.TYPE == Update.TYPE:
if Attribute.CODE.INTERNAL_TREAT_AS_WITHDRAW in message.attributes:
for nlri in message.nlris:
nlri.action = IN.WITHDRAWN
if for_api:
negotiated = self.negotiated if self.neighbor.api.get(
'negotiated', False) else None
if consolidate:
self.peer.reactor.processes.message(
msg_id, self.neighbor, 'receive', message, negotiated,
header, body)
elif parsed:
self.peer.reactor.processes.message(
msg_id, self.neighbor, 'receive', message, negotiated,
b'', b'')
if message.TYPE == Notification.TYPE:
raise message
if message.TYPE == Update.TYPE and Attribute.CODE.INTERNAL_DISCARD in message.attributes:
yield _NOP
else:
yield message
def validate_open(self):
error = self.negotiated.validate(self.neighbor)
if error is not None:
raise Notify(*error)
if self.neighbor.api['negotiated']:
self.peer.reactor.processes.negotiated(self.peer.neighbor,
self.negotiated)
if self.negotiated.mismatch:
self.logger.warning(
'--------------------------------------------------------------------',
self.connection.session())
self.logger.warning(
'the connection can not carry the following family/families',
self.connection.session())
for reason, (afi, safi) in self.negotiated.mismatch:
self.logger.warning(
' - %s is not configured for %s/%s' % (reason, afi, safi),
self.connection.session())
self.logger.warning(
'therefore no routes of this kind can be announced on the connection',
self.connection.session())
self.logger.warning(
'--------------------------------------------------------------------',
self.connection.session())
def read_open(self, ip):
for received_open in self.read_message():
if received_open.TYPE == NOP.TYPE:
yield received_open
else:
break
if received_open.TYPE != Open.TYPE:
raise Notify(
5, 1, 'The first packet received is not an open message (%s)' %
received_open)
self.logger.debug('<< %s' % received_open, self.connection.session())
yield received_open
def read_keepalive(self):
for message in self.read_message():
if message.TYPE == NOP.TYPE:
yield message
else:
break
if message.TYPE != KeepAlive.TYPE:
raise Notify(5, 2)
yield message
#
# Sending message to peer
#
def new_open(self):
if self.neighbor.local_as:
local_as = self.neighbor.local_as
elif self.negotiated.received_open:
local_as = self.negotiated.received_open.asn
else:
raise RuntimeError('no ASN available for the OPEN message')
sent_open = Open(
Version(4), local_as, self.neighbor.hold_time,
self.neighbor.router_id,
Capabilities().new(self.neighbor, self.peer._restarted))
# we do not buffer open message in purpose
for _ in self.write(sent_open):
yield _NOP
self.logger.debug('>> %s' % sent_open, self.connection.session())
yield sent_open
def new_keepalive(self, comment=''):
keepalive = KeepAlive()
for _ in self.write(keepalive):
yield _NOP
self.logger.debug(
'>> KEEPALIVE%s' % (' (%s)' % comment if comment else ''),
self.connection.session())
yield keepalive
def new_notification(self, notification):
for _ in self.write(notification):
yield _NOP
self.logger.debug(
'>> NOTIFICATION (%d,%d,"%s")' %
(notification.code, notification.subcode, notification.data),
self.connection.session())
yield notification
def new_update(self, include_withdraw):
updates = self.neighbor.rib.outgoing.updates(
self.neighbor.group_updates)
number = 0
for update in updates:
for message in update.messages(self.negotiated, include_withdraw):
number += 1
for boolean in self.send(message):
# boolean is a transient network error we already announced
yield _NOP
if number:
self.logger.debug('>> %d UPDATE(s)' % number,
self.connection.session())
yield _UPDATE
def new_eor(self, afi, safi):
eor = EOR(afi, safi)
for _ in self.write(eor):
yield _NOP
self.logger.debug('>> EOR %s %s' % (afi, safi),
self.connection.session())
yield eor
def new_eors(self, afi=AFI.undefined, safi=SAFI.undefined):
# Send EOR to let our peer know he can perform a RIB update
if self.negotiated.families:
families = self.negotiated.families if (afi, safi) == (
AFI.undefined, SAFI.undefined) else [
(afi, safi),
]
for eor_afi, eor_safi in families:
for _ in self.new_eor(eor_afi, eor_safi):
yield _
else:
# If we are not sending an EOR, send a keepalive as soon as when finished
# So the other routers knows that we have no (more) routes to send ...
# (is that behaviour documented somewhere ??)
for eor in self.new_keepalive('EOR'):
yield _NOP
yield _UPDATE
def new_operational(self, operational, negotiated):
for _ in self.write(operational, negotiated):
yield _NOP
self.logger.debug('>> OPERATIONAL %s' % str(operational),
self.connection.session())
yield operational
def new_refresh(self, refresh):
for _ in self.write(refresh, None):
yield _NOP
self.logger.debug('>> REFRESH %s' % str(refresh),
self.connection.session())
yield refresh
class Protocol (object):
decode = True
def __init__ (self, peer):
try:
self.logger = Logger()
except RuntimeError:
self.logger = FakeLogger()
self.peer = peer
self.neighbor = peer.neighbor
self.negotiated = Negotiated(self.neighbor)
self.connection = None
if self.neighbor.connect:
self.port = self.neighbor.connect
elif os.environ.get('exabgp.tcp.port','').isdigit():
self.port = int(os.environ.get('exabgp.tcp.port'))
elif os.environ.get('exabgp_tcp_port','').isdigit():
self.port = int(os.environ.get('exabgp_tcp_port'))
else:
self.port = 179
# XXX: FIXME: check the the -19 is correct (but it is harmless)
# The message size is the whole BGP message _without_ headers
self.message_size = Message.MAX_LEN-Message.HEADER_LEN
from exabgp.configuration.environment import environment
self.log_routes = peer.neighbor.adj_rib_in or environment.settings().log.routes
# XXX: we use self.peer.neighbor.peer_address when we could use self.neighbor.peer_address
def me (self, message):
return "%s/%s %s" % (self.peer.neighbor.peer_address,self.peer.neighbor.peer_as,message)
def accept (self, incoming):
self.connection = incoming
if self.peer.neighbor.api['neighbor-changes']:
self.peer.reactor.processes.connected(self.peer.neighbor)
# very important - as we use this function on __init__
return self
def connect (self):
# allows to test the protocol code using modified StringIO with a extra 'pending' function
if not self.connection:
local = self.neighbor.md5_ip.top() if not self.neighbor.auto_discovery else None
peer = self.neighbor.peer_address.top()
afi = self.neighbor.peer_address.afi
md5 = self.neighbor.md5_password
md5_base64 = self.neighbor.md5_base64
ttl_out = self.neighbor.ttl_out
self.connection = Outgoing(afi,peer,local,self.port,md5,md5_base64,ttl_out)
if not local and self.connection.init:
self.neighbor.local_address = IP.create(self.connection.local)
if self.neighbor.router_id is None and self.neighbor.local_address.afi == AFI.ipv4:
self.neighbor.router_id = self.neighbor.local_address
try:
generator = self.connection.establish()
while True:
connected = six.next(generator)
if not connected:
yield False
continue
if self.peer.neighbor.api['neighbor-changes']:
self.peer.reactor.processes.connected(self.peer.neighbor)
yield True
return
except StopIteration:
# close called by the caller
# self.close('could not connect to remote end')
yield False
return
def close (self, reason='protocol closed, reason unspecified'):
if self.connection:
self.logger.debug(reason,self.connection.session())
# must be first otherwise we could have a loop caused by the raise in the below
self.connection.close()
self.connection = None
self.peer.stats['down'] = self.peer.stats.get('down',0) + 1
try:
if self.peer.neighbor.api['neighbor-changes']:
self.peer.reactor.processes.down(self.peer.neighbor,reason)
except ProcessError:
self.logger.debug('could not send notification of neighbor close to API',self.connection.session())
def _to_api (self,direction,message,raw):
packets = self.neighbor.api['%s-packets' % direction]
parsed = self.neighbor.api['%s-parsed' % direction]
consolidate = self.neighbor.api['%s-consolidate' % direction]
negotiated = self.negotiated if self.neighbor.api['negotiated'] else None
if consolidate:
if packets:
self.peer.reactor.processes.message(self.peer.neighbor,direction,message,negotiated,raw[:19],raw[19:])
else:
self.peer.reactor.processes.message(self.peer.neighbor,direction,message,negotiated,b'',b'')
else:
if packets:
self.peer.reactor.processes.packets(self.peer.neighbor,direction,int(message.ID),negotiated,raw[:19],raw[19:])
if parsed:
self.peer.reactor.processes.message(message.ID,self.peer.neighbor,direction,message,negotiated,b'',b'')
def write (self, message, negotiated=None):
raw = message.message(negotiated)
code = 'send-%s' % Message.CODE.short(message.ID)
self.peer.stats[code] = self.peer.stats.get(code,0) + 1
if self.neighbor.api.get(code,False):
self._to_api('send',message,raw)
for boolean in self.connection.writer(raw):
yield boolean
def send (self, raw):
code = 'send-%s' % Message.CODE.short(ordinal(raw[18]))
self.peer.stats[code] = self.peer.stats.get(code,0) + 1
if self.neighbor.api.get(code,False):
message = Update.unpack_message(raw[19:],self.negotiated)
self._to_api('send',message,raw)
for boolean in self.connection.writer(raw):
yield boolean
# Read from network .......................................................
def read_message (self):
# This will always be defined by the loop but scope leaking upset scrutinizer/pylint
msg_id = None
packets = self.neighbor.api['receive-packets']
consolidate = self.neighbor.api['receive-consolidate']
parsed = self.neighbor.api['receive-parsed']
body,header = b'',b'' # just because pylint/pylama are getting more clever
for length,msg_id,header,body,notify in self.connection.reader():
# internal issue
if notify:
code = 'receive-%s' % Message.CODE.NOTIFICATION.SHORT
if self.neighbor.api.get(code,False):
if consolidate:
self.peer.reactor.processes.notification(self.peer.neighbor,'receive',notify.code,notify.subcode,str(notify),None,header,body)
elif parsed:
self.peer.reactor.processes.notification(self.peer.neighbor,'receive',notify.code,notify.subcode,str(notify),None,b'',b'')
elif packets:
self.peer.reactor.processes.packets(self.peer.neighbor,'receive',msg_id,None,header,body)
# XXX: is notify not already Notify class ?
raise Notify(notify.code,notify.subcode,str(notify))
if not length:
yield _NOP
continue
self.logger.debug('<< message of type %s' % Message.CODE.name(msg_id),self.connection.session())
code = 'receive-%s' % Message.CODE.short(msg_id)
self.peer.stats[code] = self.peer.stats.get(code,0) + 1
for_api = self.neighbor.api.get(code,False)
if for_api and packets and not consolidate:
negotiated = self.negotiated if self.neighbor.api.get('negotiated',False) else None
self.peer.reactor.processes.packets(self.peer.neighbor,'receive',msg_id,negotiated,header,body)
if msg_id == Message.CODE.UPDATE:
if not self.neighbor.adj_rib_in and not (for_api or self.log_routes) and not (parsed or consolidate):
yield _UPDATE
return
try:
message = Message.unpack(msg_id,body,self.negotiated)
except (KeyboardInterrupt,SystemExit,Notify):
raise
except Exception as exc:
self.logger.debug('could not decode message "%d"' % msg_id,self.connection.session())
self.logger.debug('%s' % str(exc),self.connection.session())
self.logger.debug(traceback.format_exc(),self.connection.session())
raise Notify(1,0,'can not decode update message of type "%d"' % msg_id)
# raise Notify(5,0,'unknown message received')
if message.TYPE == Update.TYPE:
if Attribute.CODE.INTERNAL_TREAT_AS_WITHDRAW in message.attributes:
for nlri in message.nlris:
nlri.action = IN.WITHDRAWN
if for_api:
negotiated = self.negotiated if self.neighbor.api.get('negotiated',False) else None
if consolidate:
self.peer.reactor.processes.message(msg_id,self.neighbor,'receive',message,negotiated,header,body)
elif parsed:
self.peer.reactor.processes.message(msg_id,self.neighbor,'receive',message,negotiated,b'',b'')
if message.TYPE == Notification.TYPE:
raise message
if message.TYPE == Update.TYPE and Attribute.CODE.INTERNAL_DISCARD in message.attributes:
yield _NOP
else:
yield message
def validate_open (self):
error = self.negotiated.validate(self.neighbor)
if error is not None:
raise Notify(*error)
if self.neighbor.api['negotiated']:
self.peer.reactor.processes.negotiated(self.peer.neighbor,self.negotiated)
if self.negotiated.mismatch:
self.logger.warning('--------------------------------------------------------------------',self.connection.session())
self.logger.warning('the connection can not carry the following family/families',self.connection.session())
for reason,(afi,safi) in self.negotiated.mismatch:
self.logger.warning(' - %s is not configured for %s/%s' % (reason,afi,safi),self.connection.session())
self.logger.warning('therefore no routes of this kind can be announced on the connection',self.connection.session())
self.logger.warning('--------------------------------------------------------------------',self.connection.session())
def read_open (self, ip):
for received_open in self.read_message():
if received_open.TYPE == NOP.TYPE:
yield received_open
else:
break
if received_open.TYPE != Open.TYPE:
raise Notify(5,1,'The first packet received is not an open message (%s)' % received_open)
self.logger.debug('<< %s' % received_open,self.connection.session())
yield received_open
def read_keepalive (self):
for message in self.read_message():
if message.TYPE == NOP.TYPE:
yield message
else:
break
if message.TYPE != KeepAlive.TYPE:
raise Notify(5,2)
yield message
#
# Sending message to peer
#
def new_open (self):
if self.neighbor.local_as:
local_as = self.neighbor.local_as
elif self.negotiated.received_open:
local_as = self.negotiated.received_open.asn
else:
raise RuntimeError('no ASN available for the OPEN message')
sent_open = Open(
Version(4),
local_as,
self.neighbor.hold_time,
self.neighbor.router_id,
Capabilities().new(self.neighbor,self.peer._restarted)
)
# we do not buffer open message in purpose
for _ in self.write(sent_open):
yield _NOP
self.logger.debug('>> %s' % sent_open,self.connection.session())
yield sent_open
def new_keepalive (self, comment=''):
keepalive = KeepAlive()
for _ in self.write(keepalive):
yield _NOP
self.logger.debug('>> KEEPALIVE%s' % (' (%s)' % comment if comment else ''),self.connection.session())
yield keepalive
def new_notification (self, notification):
for _ in self.write(notification):
yield _NOP
self.logger.debug('>> NOTIFICATION (%d,%d,"%s")' % (notification.code,notification.subcode,notification.data),self.connection.session())
yield notification
def new_update (self, include_withdraw):
updates = self.neighbor.rib.outgoing.updates(self.neighbor.group_updates)
number = 0
for update in updates:
for message in update.messages(self.negotiated,include_withdraw):
number += 1
for boolean in self.send(message):
# boolean is a transient network error we already announced
yield _NOP
if number:
self.logger.debug('>> %d UPDATE(s)' % number,self.connection.session())
yield _UPDATE
def new_eor (self, afi, safi):
eor = EOR(afi,safi)
for _ in self.write(eor):
yield _NOP
self.logger.debug('>> EOR %s %s' % (afi,safi),self.connection.session())
yield eor
def new_eors (self, afi=AFI.undefined,safi=SAFI.undefined):
# Send EOR to let our peer know he can perform a RIB update
if self.negotiated.families:
families = self.negotiated.families if (afi,safi) == (AFI.undefined,SAFI.undefined) else [(afi,safi),]
for eor_afi,eor_safi in families:
for _ in self.new_eor(eor_afi,eor_safi):
yield _
else:
# If we are not sending an EOR, send a keepalive as soon as when finished
# So the other routers knows that we have no (more) routes to send ...
# (is that behaviour documented somewhere ??)
for eor in self.new_keepalive('EOR'):
yield _NOP
yield _UPDATE
def new_operational (self, operational, negotiated):
for _ in self.write(operational,negotiated):
yield _NOP
self.logger.debug('>> OPERATIONAL %s' % str(operational),self.connection.session())
yield operational
def new_refresh (self, refresh):
for _ in self.write(refresh,None):
yield _NOP
self.logger.debug('>> REFRESH %s' % str(refresh),self.connection.session())
yield refresh
class Connection (object):
direction = 'undefined'
identifier = {}
def __init__ (self, afi, peer, local):
# peer and local are strings of the IP
try:
self.defensive = environment.settings().debug.defensive
self.logger = Logger()
except RuntimeError:
self.defensive = True
self.logger = FakeLogger()
self.afi = afi
self.peer = peer
self.local = local
self.io = None
self.established = False
self.id = self.identifier.get(self.direction,1)
def success (self):
identifier = self.identifier.get(self.direction,1) + 1
self.identifier[self.direction] = identifier
return identifier
# Just in case ..
def __del__ (self):
if self.io:
self.logger.warning('connection to %s closed' % self.peer,self.session())
self.close()
def name (self):
return "%s-%d %s-%s" % (self.direction,self.id,self.local,self.peer)
def session (self):
return "%s-%d" % (self.direction,self.id)
def close (self):
try:
self.logger.warning('%s, closing connection' % self.name(),source=self.session())
if self.io:
self.io.close()
self.io = None
except KeyboardInterrupt as exc:
raise exc
except Exception:
pass
def reading (self):
while True:
try:
r,_,_ = select.select([self.io,],[],[],0)
except select.error as exc:
if exc.args[0] not in error.block:
self.close()
self.logger.warning('%s %s errno %s on socket' % (self.name(),self.peer,errno.errorcode[exc.args[0]]),self.session())
raise NetworkError('errno %s on socket' % errno.errorcode[exc.args[0]])
return False
return r != []
def writing (self):
while True:
try:
_,w,_ = select.select([],[self.io,],[],0)
except select.error as exc:
if exc.args[0] not in error.block:
self.close()
self.logger.warning('%s %s errno %s on socket' % (self.name(),self.peer,errno.errorcode[exc.args[0]]),self.session())
raise NetworkError('errno %s on socket' % errno.errorcode[exc.args[0]])
return False
return w != []
def _reader (self, number):
# The function must not be called if it does not return with no data with a smaller size as parameter
if not self.io:
self.close()
raise NotConnected('Trying to read on a closed TCP connection')
if number == 0:
yield b''
return
while not self.reading():
yield b''
data = b''
reported = ''
while True:
try:
while True:
if self.defensive and random.randint(0,2):
raise socket.error(errno.EAGAIN,'raising network error on purpose')
read = self.io.recv(number)
if not read:
self.close()
self.logger.warning('%s %s lost TCP session with peer' % (self.name(),self.peer),self.session())
raise LostConnection('the TCP connection was closed by the remote end')
data += read
number -= len(read)
if not number:
self.logger.debug(LazyFormat('received TCP payload',data),self.session())
yield data
return
yield b''
except socket.timeout as exc:
self.close()
self.logger.warning('%s %s peer is too slow' % (self.name(),self.peer),self.session())
raise TooSlowError('Timeout while reading data from the network (%s)' % errstr(exc))
except socket.error as exc:
if exc.args[0] in error.block:
message = '%s %s blocking io problem mid-way through reading a message %s, trying to complete' % (self.name(),self.peer,errstr(exc))
if message != reported:
reported = message
self.logger.debug(message,self.session())
yield b''
elif exc.args[0] in error.fatal:
self.close()
raise LostConnection('issue reading on the socket: %s' % errstr(exc))
# what error could it be !
else:
self.logger.critical('%s %s undefined error reading on socket' % (self.name(),self.peer),self.session())
raise NetworkError('Problem while reading data from the network (%s)' % errstr(exc))
def writer (self, data):
if not self.io:
# XXX: FIXME: Make sure it does not hold the cleanup during the closing of the peering session
yield True
return
while not self.writing():
yield False
self.logger.debug(LazyFormat('sending TCP payload',data),self.session())
# The first while is here to setup the try/catch block once as it is very expensive
while True:
try:
while True:
if self.defensive and random.randint(0,2):
raise socket.error(errno.EAGAIN,'raising network error on purpose')
# we can not use sendall as in case of network buffer filling
# it does raise and does not let you know how much was sent
number = self.io.send(data)
if not number:
self.close()
self.logger.warning('%s %s lost TCP connection with peer' % (self.name(),self.peer),self.session())
raise LostConnection('lost the TCP connection')
data = data[number:]
if not data:
yield True
return
yield False
except socket.error as exc:
if exc.args[0] in error.block:
self.logger.debug(
'%s %s blocking io problem mid-way through writing a message %s, trying to complete' % (
self.name(),
self.peer,
errstr(exc)
),
self.session()
)
yield False
elif exc.errno == errno.EPIPE:
# The TCP connection is gone.
self.close()
raise NetworkError('Broken TCP connection')
elif exc.args[0] in error.fatal:
self.close()
self.logger.critical('%s %s problem sending message (%s)' % (self.name(),self.peer,errstr(exc)),self.session())
raise NetworkError('Problem while writing data to the network (%s)' % errstr(exc))
# what error could it be !
else:
self.logger.critical('%s %s undefined error writing on socket' % (self.name(),self.peer),self.session())
yield False
def reader (self):
# _reader returns the whole number requested or nothing and then stops
for header in self._reader(Message.HEADER_LEN):
if not header:
yield 0,0,b'',b'',None
if not header.startswith(Message.MARKER):
report = 'The packet received does not contain a BGP marker'
yield 0,0,header,b'',NotifyError(1,1,report)
return
msg = ordinal(header[18])
length = unpack('!H',header[16:18])[0]
if length < Message.HEADER_LEN or length > Message.MAX_LEN:
report = '%s has an invalid message length of %d' % (Message.CODE.name(msg),length)
yield length,0,header,b'',NotifyError(1,2,report)
return
validator = Message.Length.get(msg,lambda _: _ >= 19)
if not validator(length):
# MUST send the faulty length back
report = '%s has an invalid message length of %d' % (Message.CODE.name(msg),length)
yield length,0,header,b'',NotifyError(1,2,report)
return
number = length - Message.HEADER_LEN
if not number:
yield length,msg,header,b'',None
return
for body in self._reader(number):
if not body:
yield 0,0,b'',b'',None
yield length,msg,header,body,None
