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
logfunc.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()
log.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:
log.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()
log.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:
log.critical(
'%s %s undefined error writing on socket' %
(self.name(), self.peer), self.session())
yield False
def unpack_nlri(cls, afi, safi, data, action, addpath):
a, s = AFI.create(afi), SAFI.create(safi)
logfunc.debug(lazynlri(a, s, addpath, data), 'parser')
key = '%s/%s' % (a, s)
if key in cls.registered_nlri:
return cls.registered_nlri[key].unpack_nlri(
a, s, data, action, addpath)
raise Notify(3, 0, 'trying to decode unknown family %s/%s' % (a, s))
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()
log.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:
logfunc.debug(lazyformat('received TCP payload', data), self.session())
yield data
return
yield b''
except socket.timeout as exc:
self.close()
log.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
log.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:
log.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 parse(self, data, direction, negotiated):
if not data:
return self
try:
# We do not care if the attribute are transitive or not as we do not redistribute
flag = Attribute.Flag(data[0])
aid = Attribute.CODE(data[1])
except IndexError:
self.add(TreatAsWithdraw())
return self
try:
offset = 3
length = data[2]
if flag & Attribute.Flag.EXTENDED_LENGTH:
offset = 4
length = (length << 8) + data[3]
except IndexError:
self.add(TreatAsWithdraw(aid))
return self
data = data[offset:]
left = data[length:]
attribute = data[:length]
logfunc.debug(lazyattribute(flag, aid, length, data[:length]), 'parser')
# remove the PARTIAL bit before comparaison if the attribute is optional
if aid in Attribute.attributes_optional:
flag &= Attribute.Flag.MASK_PARTIAL & 0xFF
# flag &= ~Attribute.Flag.PARTIAL & 0xFF # cleaner than above (python use signed integer for ~)
if aid in self:
if aid in self.NO_DUPLICATE:
raise Notify(3, 1, 'multiple attribute for %s' % str(Attribute.CODE(attribute.ID)))
log.debug(
'duplicate attribute %s (flag 0x%02X, aid 0x%02X) skipping'
% (Attribute.CODE.names.get(aid, 'unset'), flag, aid),
'parser',
)
return self.parse(left, direction, negotiated)
# handle the attribute if we know it
if Attribute.registered(aid, flag):
if length == 0 and aid not in self.VALID_ZERO:
self.add(TreatAsWithdraw(aid))
return self.parse(left, direction, negotiated)
try:
decoded = Attribute.unpack(aid, flag, attribute, direction, negotiated)
except IndexError as exc:
if aid in self.TREAT_AS_WITHDRAW:
decoded = TreatAsWithdraw(aid)
else:
raise exc
except Notify as exc:
if aid in self.TREAT_AS_WITHDRAW:
decoded = TreatAsWithdraw()
elif aid in self.DISCARD:
decoded = Discard()
else:
raise exc
self.add(decoded)
return self.parse(left, direction, negotiated)
# XXX: FIXME: we could use a fallback function here like capability
# if we know the attribute but the flag is not what the RFC says.
if aid in Attribute.attributes_known:
if aid in self.TREAT_AS_WITHDRAW:
log.debug(
'invalid flag for attribute %s (flag 0x%02X, aid 0x%02X) treat as withdraw'
% (Attribute.CODE.names.get(aid, 'unset'), flag, aid),
'parser',
)
self.add(TreatAsWithdraw())
if aid in self.DISCARD:
log.debug(
'invalid flag for attribute %s (flag 0x%02X, aid 0x%02X) discard'
% (Attribute.CODE.names.get(aid, 'unset'), flag, aid),
'parser',
)
return self.parse(left, direction, negotiated)
# XXX: Check if we are missing any
log.debug(
'invalid flag for attribute %s (flag 0x%02X, aid 0x%02X) unspecified (should not happen)'
% (Attribute.CODE.names.get(aid, 'unset'), flag, aid),
'parser',
)
return self.parse(left, direction, negotiated)
# it is an unknown transitive attribute we need to pass on
if flag & Attribute.Flag.TRANSITIVE:
log.debug('unknown transitive attribute (flag 0x%02X, aid 0x%02X)' % (flag, aid), 'parser')
try:
decoded = GenericAttribute(aid, flag | Attribute.Flag.PARTIAL, attribute)
except IndexError:
decoded = TreatAsWithdraw(aid)
self.add(decoded, attribute)
return self.parse(left, direction, negotiated)
# it is an unknown non-transitive attribute we can ignore.
log.debug('ignoring unknown non-transitive attribute (flag 0x%02X, aid 0x%02X)' % (flag, aid), 'parser')
return self.parse(left, direction, negotiated)
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
log.info('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
log.debug('<< UPDATE #%d' % number, self.id())
for nlri in message.nlris:
self.neighbor.rib.incoming.update_cache(Change(nlri, message.attributes))
logfunc.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['capability']['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:
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['capability']['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:
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:
count = 1 if self.neighbor['rate-limit'] > 0 else 25
try:
for _ in range(count):
# This can raise a NetworkError
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
log.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:
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['capability']['graceful-restart'] and self.proto.negotiated.sent_open.capabilities.announced(
Capability.CODE.GRACEFUL_RESTART
):
log.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 unpack_message(cls, data, direction, negotiated):
logfunc.debug(lazyformat('parsing UPDATE', data), 'parser')
length = len(data)
# This could be speed up massively by changing the order of the IF
if length == 4 and data == b'\x00\x00\x00\x00':
return EOR(AFI.ipv4, SAFI.unicast) # pylint: disable=E1101
if length == 11 and data.startswith(EOR.NLRI.PREFIX):
return EOR.unpack_message(data, direction, negotiated)
withdrawn, _attributes, announced = cls.split(data)
if not withdrawn:
log.debug('withdrawn NLRI none', 'routes')
attributes = Attributes.unpack(_attributes, direction, negotiated)
if not announced:
log.debug('announced NLRI none', 'routes')
# Is the peer going to send us some Path Information with the route (AddPath)
if direction == Direction.IN:
addpath = negotiated.addpath.receive(AFI.ipv4, SAFI.unicast)
else:
addpath = negotiated.addpath.send(AFI.ipv4, SAFI.unicast)
# empty string for NoNextHop, the packed IP otherwise (without the 3/4 bytes of attributes headers)
nexthop = attributes.get(Attribute.CODE.NEXT_HOP, NoNextHop)
# nexthop = NextHop.unpack(_nexthop.ton())
# XXX: NEXTHOP MUST NOT be the IP address of the receiving speaker.
nlris = []
while withdrawn:
nlri, left = NLRI.unpack_nlri(AFI.ipv4, SAFI.unicast, withdrawn, IN.WITHDRAWN, addpath)
log.debug('withdrawn NLRI %s' % nlri, 'routes')
withdrawn = left
nlris.append(nlri)
while announced:
nlri, left = NLRI.unpack_nlri(AFI.ipv4, SAFI.unicast, announced, IN.ANNOUNCED, addpath)
nlri.nexthop = nexthop
log.debug('announced NLRI %s' % nlri, 'routes')
announced = left
nlris.append(nlri)
unreach = attributes.pop(MPURNLRI.ID, None)
reach = attributes.pop(MPRNLRI.ID, None)
if unreach is not None:
nlris.extend(unreach.nlris)
if reach is not None:
nlris.extend(reach.nlris)
if not attributes and not nlris:
# Careful do not use == or != as the comparaison does not work
if unreach is None and reach is None:
return EOR(AFI.ipv4, SAFI.unicast)
if unreach is not None:
return EOR(unreach.afi, unreach.safi)
if reach is not None:
return EOR(reach.afi, reach.safi)
raise RuntimeError('This was not expected')
update = Update(nlris, attributes)
def parsed(_):
# we need the import in the function as otherwise we have an cyclic loop
# as this function currently uses Update..
from exabgp.reactor.api.response import Response
from exabgp.version import json as json_version
return 'json %s' % Response.JSON(json_version).update(negotiated.neighbor, 'receive', update, None, '', '')
logfunc.debug(lazyformat('decoded UPDATE', '', parsed), 'parser')
return update
