def setUp(self):
self.bundle = TransactionBundle(relayed_solicit_message, True)
self.ia_bundle = TransactionBundle(SolicitMessage(options=[
IANAOption(b'0001'),
IANAOption(b'0002'),
IATAOption(b'0003'),
IATAOption(b'0004'),
IAPDOption(b'0005'),
IAPDOption(b'0006'),
]), False)
self.option_handlers = [
InterfaceIdOptionHandler(),
]
def post(self, bundle: TransactionBundle):
"""
Upgrade the response from a AdvertiseMessage to a ReplyMessage if appropriate
:param bundle: The transaction bundle
"""
# Does this transaction even allow rapid commit?
if not bundle.allow_rapid_commit:
return
# We only look for SolicitMessages that have a RapidCommitOption
if not isinstance(bundle.request, SolicitMessage) or not bundle.request.get_option_of_type(RapidCommitOption):
return
# And only if the current response is an AdvertiseMessage
if not isinstance(bundle.response, AdvertiseMessage):
return
# Ok, this looks promising, do extra checks if requested
if not self.rapid_commit_rejections:
# Ok, we don't want to rapid-commit rejections. Check for them.
if bundle.get_unanswered_ia_options() or bundle.get_unanswered_iapd_options():
# Unhandled options. We are post-processing, so they are not going to be answered anymore
return
# Did we already refuse anything?
ia_options = [option for option in bundle.response.options if isinstance(option, (IANAOption, IATAOption))]
for option in ia_options:
status = option.get_option_of_type(StatusCodeOption)
if status and status.status_code == STATUS_NOADDRSAVAIL:
# Refusal: don't do anything
return
iapd_options = [option for option in bundle.response.options if isinstance(option, IAPDOption)]
for option in iapd_options:
status = option.get_option_of_type(StatusCodeOption)
if status and status.status_code == STATUS_NOPREFIXAVAIL:
# Refusal: don't do anything
return
# It seems the request and response qualify: upgrade to ReplyMessage
bundle.response = ReplyMessage(bundle.response.transaction_id, [RapidCommitOption()] + bundle.response.options)
def handle_confirm(self, bundle: TransactionBundle):
"""
Handle a client requesting confirmation
:param bundle: The request bundle
"""
# Make sure we are responsible for this link
link_address = bundle.get_link_address()
if not address_in_prefixes(link_address, self.responsible_for_links):
logger.debug("Not confirming to link {}: "
"doesn't match {}".format(link_address, ', '.join(map(str, self.responsible_for_links))))
return
# Get the assignment
assignment = self.get_assignment(bundle)
# Collect unanswered options
unanswered_iana_options = bundle.get_unanswered_iana_options()
# See if there are any addresses on a link that I am responsible for
for option in unanswered_iana_options:
for suboption in option.get_options_of_type(IAAddressOption):
if suboption.address == assignment.address:
# This is the address from the assignment: it's ok
bundle.mark_handled(option)
continue
if address_in_prefixes(suboption.address, self.responsible_for_links):
# Oops, an address on a link that I am responsible for, but it's the wrong one...
force_status(bundle.response.options,
StatusCodeOption(STATUS_NOTONLINK,
"{} is not assigned to you".format(suboption.address)))
bundle.mark_handled(option)
return
def handle_renew_rebind(self, bundle: TransactionBundle):
"""
Handle a client renewing/rebinding addresses
:param bundle: The request bundle
"""
# Get the assignment
assignment = self.get_assignment(bundle)
# Client ID for logging
client_id_option = bundle.request.get_option_of_type(ClientIdOption)
# Collect unanswered options
unanswered_iana_options = bundle.get_unanswered_iana_options()
unanswered_iapd_options = bundle.get_unanswered_iapd_options()
for option in unanswered_iapd_options:
if assignment.prefix and prefix_overlaps_prefixes(assignment.prefix, option.get_prefixes()):
# Overlap with our assigned prefix: take responsibility
response_suboptions = []
for suboption in option.get_options_of_type(IAPrefixOption):
if suboption.prefix == assignment.prefix:
# This is the correct option, renew it
logger.info("Renewing {} for {!r}".format(assignment.prefix, client_id_option.duid))
response_suboptions.append(IAPrefixOption(prefix=assignment.prefix,
preferred_lifetime=self.prefix_preferred_lifetime,
valid_lifetime=self.prefix_valid_lifetime))
else:
# This isn't right
logger.info("Withdrawing {} from {!r}".format(suboption.prefix, client_id_option.duid))
response_suboptions.append(IAPrefixOption(prefix=suboption.prefix,
preferred_lifetime=0, valid_lifetime=0))
response_option = IAPDOption(option.iaid, options=response_suboptions)
bundle.response.options.append(response_option)
bundle.mark_handled(option)
for option in unanswered_iana_options:
if any([address_in_prefixes(address, self.responsible_for_links) for address in option.get_addresses()]):
# Overlap with our addresses: take responsibility
response_suboptions = []
for suboption in option.get_options_of_type(IAAddressOption):
if suboption.address == assignment.address:
# This is the correct option, renew it
logger.info("Renewing {} for {!r}".format(assignment.address, client_id_option.duid))
response_suboptions.append(IAAddressOption(address=assignment.address,
preferred_lifetime=self.address_preferred_lifetime,
valid_lifetime=self.address_valid_lifetime))
else:
# This isn't right
logger.info("Withdrawing {} from {!r}".format(suboption.address, client_id_option.duid))
response_suboptions.append(IAAddressOption(address=suboption.address,
preferred_lifetime=0, valid_lifetime=0))
response_option = IANAOption(option.iaid, options=response_suboptions)
bundle.response.options.append(response_option)
bundle.mark_handled(option)
def handle_request(self, bundle: TransactionBundle):
"""
Handle a client requesting addresses (also handles SolicitMessage)
:param bundle: The request bundle
"""
# Get the assignment
assignment = self.get_assignment(bundle)
# Collect unanswered options
unanswered_iana_options = bundle.get_unanswered_iana_options()
unanswered_iapd_options = bundle.get_unanswered_iapd_options()
# Try to assign the prefix first: it's not dependent on the link
if assignment.prefix:
found_option = self.find_iapd_option_for_prefix(unanswered_iapd_options, assignment.prefix)
if found_option:
# Answer to this option
logger.info("Assigning {} to {!r}".format(assignment.prefix,
bundle.request.get_option_of_type(ClientIdOption).duid))
response_option = IAPDOption(found_option.iaid, options=[
IAPrefixOption(prefix=assignment.prefix,
preferred_lifetime=self.prefix_preferred_lifetime,
valid_lifetime=self.prefix_valid_lifetime)
])
bundle.response.options.append(response_option)
bundle.mark_handled(found_option)
# Make sure we are responsible for this link
link_address = bundle.get_link_address()
if not address_in_prefixes(link_address, self.responsible_for_links):
logger.debug("Not assigning to link {}: "
"doesn't match {}".format(link_address, ', '.join(map(str, self.responsible_for_links))))
return
if assignment.address:
found_option = self.find_iana_option_for_address(unanswered_iana_options, assignment.address)
if found_option:
# Answer to this option
logger.info("Assigning {} to {!r}".format(assignment.address,
bundle.request.get_option_of_type(ClientIdOption).duid))
response_option = IANAOption(found_option.iaid, options=[
IAAddressOption(address=assignment.address,
preferred_lifetime=self.address_preferred_lifetime,
valid_lifetime=self.address_valid_lifetime)
])
bundle.response.options.append(response_option)
bundle.mark_handled(found_option)
def handle_release_decline(self, bundle: TransactionBundle):
"""
Handle a client releasing or declining resources. Doesn't really need to do anything because assignments are
fixed. Just mark the right options as handled.
:param bundle: The request bundle
"""
# Get the assignment
assignment = self.get_assignment(bundle)
# Collect unanswered options
unanswered_iana_options = bundle.get_unanswered_iana_options()
unanswered_iapd_options = bundle.get_unanswered_iapd_options()
for option in unanswered_iapd_options:
if assignment.prefix and prefix_overlaps_prefixes(assignment.prefix, option.get_prefixes()):
# Overlap with our assigned prefix: take responsibility
bundle.mark_handled(option)
for option in unanswered_iana_options:
if any([address_in_prefixes(address, self.responsible_for_links) for address in option.get_addresses()]):
# Overlap with our addresses: take responsibility
bundle.mark_handled(option)
def handle(self, bundle: TransactionBundle):
"""
Make sure that every :class:`.IANAOption` and :class:`.IATAOption` is answered.
:param bundle: The transaction bundle
"""
for option in bundle.get_unanswered_ia_options():
ia_class = type(option)
if isinstance(bundle.request, (SolicitMessage, RequestMessage)):
# If the server will not assign any addresses to any IAs in a subsequent Request from the client, the
# server MUST send an Advertise message to the client that includes only a Status Code option with code
# NoAddrsAvail and a status message for the user
#
# We do the same for unanswered requests
bundle.response.options.append(ia_class(option.iaid, options=[
StatusCodeOption(STATUS_NOADDRSAVAIL, "No addresses available")
]))
elif isinstance(bundle.request, ConfirmMessage):
# When the server receives a Confirm message, the server determines whether the addresses in the
# Confirm message are appropriate for the link to which the client is attached. If all of the
# addresses in the Confirm message pass this test, the server returns a status of Success. If any of
# the addresses do not pass this test, the server returns a status of NotOnLink. If the server is
# unable to perform this test (for example, the server does not have information about prefixes on the
# link to which the client is connected), or there were no addresses in any of the IAs sent by the
# client, the server MUST NOT send a reply to the client.
#
# The "there were no addresses in any of the IAs sent by the client" check is done by the message
# handler.
if not self.authoritative:
raise CannotRespondError
addresses = ', '.join([str(suboption.address)
for suboption in option.get_options_of_type(IAAddressOption)])
logger.warning("No handler confirmed {} for {}: "
"sending NotOnLink status".format(addresses, bundle.get_link_address()))
force_status(bundle.response.options,
StatusCodeOption(STATUS_NOTONLINK, "Those addresses are not appropriate on this link"))
elif isinstance(bundle.request, RenewMessage):
# If the server cannot find a client entry for the IA the server returns the IA containing no addresses
# with a Status Code option set to NoBinding in the Reply message.
#
# If the server finds that any of the addresses are not appropriate for the link to which the client is
# attached, the server returns the address to the client with lifetimes of 0.
addresses = ', '.join([str(suboption.address)
for suboption in option.get_options_of_type(IAAddressOption)])
if self.authoritative:
logger.warning("No handler renewed {} for {}: "
"withdrawing addresses".format(addresses, bundle.get_link_address()))
reply_suboptions = []
for suboption in option.get_options_of_type(IAAddressOption):
reply_suboptions.append(IAAddressOption(suboption.address,
preferred_lifetime=0, valid_lifetime=0))
bundle.response.options.append(ia_class(option.iaid, options=reply_suboptions))
else:
logger.warning("No handler renewed {} for {}: "
"sending NoBinding status".format(addresses, bundle.get_link_address()))
bundle.response.options.append(ia_class(option.iaid, options=[
StatusCodeOption(STATUS_NOBINDING, "No addresses assigned to you")
]))
elif isinstance(bundle.request, RebindMessage):
# If the server cannot find a client entry for the IA and the server determines that the addresses in
# the IA are not appropriate for the link to which the client's interface is attached according to the
# server's explicit configuration information, the server MAY send a Reply message to the client
# containing the client's IA, with the lifetimes for the addresses in the IA set to zero. This Reply
# constitutes an explicit notification to the client that the addresses in the IA are no longer valid.
# In this situation, if the server does not send a Reply message it silently discards the Rebind
# message.
#
# If the server finds that any of the addresses are no longer appropriate for the link to which the
# client is attached, the server returns the address to the client with lifetimes of 0.
if not self.authoritative:
raise CannotRespondError
addresses = ', '.join([str(suboption.address)
for suboption in option.get_options_of_type(IAAddressOption)])
logger.warning("No handler answered rebind of {} for {}: "
"withdrawing addresses".format(addresses, bundle.get_link_address()))
reply_suboptions = []
for suboption in option.get_options_of_type(IAAddressOption):
reply_suboptions.append(IAAddressOption(suboption.address, preferred_lifetime=0, valid_lifetime=0))
bundle.response.options.append(ia_class(option.iaid, options=reply_suboptions))
elif isinstance(bundle.request, DeclineMessage):
# For each IA in the Decline message for which the server has no binding information, the server adds
# an IA option using the IAID from the Release message and includes a Status Code option with the value
# NoBinding in the IA option. No other options are included in the IA option.
bundle.response.options.append(ia_class(option.iaid, options=[
StatusCodeOption(STATUS_NOBINDING, "No addresses assigned to you")
]))
elif isinstance(bundle.request, ReleaseMessage):
# For each IA in the Release message for which the server has no binding information, the server adds an
# IA option using the IAID from the Release message, and includes a Status Code option with the value
# NoBinding in the IA option. No other options are included in the IA option.
bundle.response.options.append(ia_class(option.iaid, options=[
StatusCodeOption(STATUS_NOBINDING, "No addresses assigned to you")
]))
def handle(self, bundle: TransactionBundle):
"""
Make sure that every :class:`.IAPDOption` is answered.
:param bundle: The transaction bundle
"""
for option in bundle.get_unanswered_iapd_options():
if isinstance(bundle.request, (SolicitMessage, RequestMessage)):
# If the delegating router will not assign any prefixes to any IA_PDs in a subsequent Request from the
# requesting router, the delegating router MUST send an Advertise message to the requesting router that
# includes the IA_PD with no prefixes in the IA_PD and a Status Code option in the IA_PD containing
# status code NoPrefixAvail and a status message for the user
#
# We do the same for unanswered requests
bundle.response.options.append(IAPDOption(option.iaid, options=[
StatusCodeOption(STATUS_NOPREFIXAVAIL, "No prefixes available")
]))
elif isinstance(bundle.request, RenewMessage):
# Renew message: If the delegating router cannot find a binding for the requesting router's IA_PD the
# delegating router returns the IA_PD containing no prefixes with a Status Code option set to
# NoBinding in the Reply message.
prefixes = ', '.join([str(suboption.prefix)
for suboption in option.get_options_of_type(IAPrefixOption)])
logger.warning("No handler renewed {} for {}: "
"sending NoBinding status".format(prefixes, bundle.get_link_address()))
bundle.response.options.append(IAPDOption(option.iaid, options=[
StatusCodeOption(STATUS_NOBINDING, "No prefixes assigned to you")
]))
elif isinstance(bundle.request, RebindMessage):
# Rebind message: If the delegating router cannot find a binding for the requesting router's IA_PD and
# the delegating router determines that the prefixes in the IA_PD are not appropriate for the link to
# which the requesting router's interface is attached according to the delegating routers explicit
# configuration, the delegating router MAY send a Reply message to the requesting router containing
# the IA_PD with the lifetimes of the prefixes in the IA_PD set to zero. This Reply constitutes an
# explicit notification to the requesting router that the prefixes in the IA_PD are no longer valid.
#
# If the delegating router is unable to determine if the prefix is not appropriate for the link, the
# Rebind message is discarded.
#
# The authoritative flag indicates whether this option may claim whether it is able to determine if a
# prefix is appropriate for the link.
if not self.authoritative:
raise CannotRespondError
prefixes = ', '.join([str(suboption.prefix)
for suboption in option.get_options_of_type(IAPrefixOption)])
logger.warning("No handler answered rebind of {} for {}: "
"withdrawing prefixes".format(prefixes, bundle.get_link_address()))
reply_suboptions = []
for suboption in option.get_options_of_type(IAPrefixOption):
reply_suboptions.append(IAPrefixOption(suboption.prefix, preferred_lifetime=0, valid_lifetime=0))
bundle.response.options.append(IAPDOption(option.iaid, options=reply_suboptions))
elif isinstance(bundle.request, ReleaseMessage):
# For each IA in the Release message for which the server has no binding information, the server adds an
# IA option using the IAID from the Release message, and includes a Status Code option with the value
# NoBinding in the IA option. No other options are included in the IA option.
bundle.response.options.append(IAPDOption(option.iaid, options=[
StatusCodeOption(STATUS_NOBINDING, "No prefixes assigned to you")
]))
class TransactionBundleTestCase(unittest.TestCase):
def setUp(self):
self.bundle = TransactionBundle(relayed_solicit_message, True)
self.ia_bundle = TransactionBundle(SolicitMessage(options=[
IANAOption(b'0001'),
IANAOption(b'0002'),
IATAOption(b'0003'),
IATAOption(b'0004'),
IAPDOption(b'0005'),
IAPDOption(b'0006'),
]), False)
self.option_handlers = [
InterfaceIdOptionHandler(),
]
def test_request(self):
self.assertEqual(self.bundle.request, solicit_message)
def test_incoming_relay_messages(self):
self.assertEqual(len(self.bundle.incoming_relay_messages), 2)
self.assertEqual(self.bundle.incoming_relay_messages[0].hop_count, 0)
self.assertEqual(self.bundle.incoming_relay_messages[1].hop_count, 1)
def test_no_response(self):
self.assertRaisesRegex(ValueError, 'Cannot create outgoing',
self.bundle.create_outgoing_relay_messages)
def test_bad_response(self):
self.bundle.response = SolicitMessage()
with self.assertLogs() as cm:
self.assertIsNone(self.bundle.outgoing_message)
self.assertEqual(len(cm.output), 1)
self.assertRegex(cm.output[0], 'server should not send')
def test_outgoing_message(self):
# Set the response and let the option handlers do their work
# Which in this case is copy the InterfaceId to the response
self.bundle.response = advertise_message
self.bundle.create_outgoing_relay_messages()
for option_handler in self.option_handlers:
option_handler.handle(self.bundle)
self.assertEqual(self.bundle.outgoing_message, relayed_advertise_message)
def test_direct_outgoing_message(self):
self.ia_bundle.response = advertise_message
self.assertEqual(self.ia_bundle.outgoing_message, advertise_message)
def test_auto_create_outgoing_relay_messages(self):
self.bundle.response = advertise_message
self.assertIsInstance(self.bundle.outgoing_message, RelayReplyMessage)
def test_no_outgoing_message(self):
self.assertIsNone(self.bundle.outgoing_message)
def test_unanswered_ia_options(self):
unanswered_options = self.ia_bundle.get_unanswered_ia_options()
self.assertEqual(len(unanswered_options), 4)
self.assertIn(IANAOption(b'0001'), unanswered_options)
self.assertIn(IANAOption(b'0002'), unanswered_options)
self.assertIn(IATAOption(b'0003'), unanswered_options)
self.assertIn(IATAOption(b'0004'), unanswered_options)
def test_mark_handled(self):
self.ia_bundle.mark_handled(IANAOption(b'0001'))
self.ia_bundle.mark_handled(IATAOption(b'0004'))
unanswered_options = self.ia_bundle.get_unanswered_ia_options()
self.assertEqual(len(unanswered_options), 2)
self.assertIn(IANAOption(b'0002'), unanswered_options)
self.assertIn(IATAOption(b'0003'), unanswered_options)
def test_unanswered_iana_options(self):
unanswered_options = self.ia_bundle.get_unanswered_iana_options()
self.assertEqual(len(unanswered_options), 2)
self.assertIn(IANAOption(b'0001'), unanswered_options)
self.assertIn(IANAOption(b'0002'), unanswered_options)
def test_unanswered_iata_options(self):
unanswered_options = self.ia_bundle.get_unanswered_iata_options()
self.assertEqual(len(unanswered_options), 2)
self.assertIn(IATAOption(b'0003'), unanswered_options)
self.assertIn(IATAOption(b'0004'), unanswered_options)
def test_unanswered_iapd_options(self):
unanswered_options = self.ia_bundle.get_unanswered_iapd_options()
self.assertEqual(len(unanswered_options), 2)
self.assertIn(IAPDOption(b'0005'), unanswered_options)
self.assertIn(IAPDOption(b'0006'), unanswered_options)
def test_unknown_message(self):
with self.assertLogs() as cm:
TransactionBundle(UnknownMessage(1608, b'Unknown'), False)
self.assertEqual(len(cm.output), 1)
self.assertRegex(cm.output[0], 'unrecognised message')
def test_wrong_way(self):
with self.assertLogs() as cm:
TransactionBundle(ReplyMessage(), False)
self.assertEqual(len(cm.output), 1)
self.assertRegex(cm.output[0], 'server should not receive')
def test_link_address(self):
self.assertEqual(self.bundle.get_link_address(), IPv6Address('2001:db8:ffff:1::1'))
self.assertEqual(self.ia_bundle.get_link_address(), IPv6Address('::'))