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('::'))