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Diffstat (limited to 'netmodel/network/router.py')
| -rw-r--r-- | netmodel/network/router.py | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/netmodel/network/router.py b/netmodel/network/router.py new file mode 100644 index 00000000..84d69dca --- /dev/null +++ b/netmodel/network/router.py @@ -0,0 +1,257 @@ +#!/usr/bin/env python3 +# -*- coding: utf-8 -*- +# +# Copyright (c) 2017 Cisco and/or its affiliates. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at: +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +# + +import asyncio +import logging +import random +import string +import traceback + +from netmodel.network.interface import Interface, InterfaceState +from netmodel.network.fib import FIB +from netmodel.network.flow_table import FlowTable +from netmodel.network.packet import Packet, ErrorPacket + +log = logging.getLogger(__name__) + +class Router: + + #-------------------------------------------------------------------------- + # Constructor, destructor, accessors + #-------------------------------------------------------------------------- + + def __init__(self, vicn_callback = None): + """ + Constructor. + Args: + allowed_capabilities: A Capabilities instance which defines which + operation can be performed by this Router. Pass None if there + is no restriction. + """ + # FIB + self._fib = FIB() + + # Per-interface flow table + self._flow_table = FlowTable() + + # interface_uuid -> interface + self._interfaces = dict() + + self._vicn_callback = vicn_callback + + def terminate(self): + for interface in self._interfaces.values(): + interface.terminate() + + # Accessors + + def get_fib(self): + return self._fib + + #-------------------------------------------------------------------------- + # Collection management + #-------------------------------------------------------------------------- + + def register_local_collection(self, cls): + self.get_interface(LOCAL_NAMESPACE).register_collection(cls, + LOCAL_NAMESPACE) + + def register_collection(self, cls, namespace=None): + self.get_interface(LOCAL_NAMESPACE).register_collection(cls, namespace) + + #-------------------------------------------------------------------------- + # Interface management + #-------------------------------------------------------------------------- + + def _register_interface(self, interface, name=None): + if not name: + name = 'interface-' + ''.join(random.choice(string.ascii_uppercase + + string.digits) for _ in range(3)) + interface.name = name + self._interfaces[name] = interface + + # Populate interface callbacks + interface.add_up_callback(self.on_interface_up) + interface.add_down_callback(self.on_interface_down) + interface.add_spawn_callback(self.on_interface_spawn) + interface.add_delete_callback(self.on_interface_delete) + + log.info('Successfully created interface {} with name {}'.format( + interface.__interface__, name)) + + interface.set_state(InterfaceState.PendingUp) + + for prefix in interface.get_prefixes(): + self._fib.add(prefix, [interface]) + + return interface + + def _unregister_interface(self, interface): + del self._interfaces[interface.name] + + # Interface events + + #-------------------------------------------------------------------------- + # Interface management + #-------------------------------------------------------------------------- + + def on_interface_up(self, interface): + """ + This callback is triggered when an interface becomes up. + + The router will request metadata. + The flow table is notified. + """ + self._flow_table._on_interface_up(interface) + + def on_interface_down(self, interface): + # We need to remove corresponding FIB entries + log.info("Router interface is now down") + + def on_interface_spawn(self, interface): + self._register_interface(interface) + + def on_interface_delete(self, interface): + """Callback : an interface has been deleted. + + - TODO : purge the FIB + - inform the flow table for managing pending subscriptions. + """ + self._unregister_interface(interface) + self._flow_table._on_interface_delete(interface) + + #--------------------------------------------------------------------------- + # Public API + #--------------------------------------------------------------------------- + + def add_interface(self, interface_type, name=None, namespace=None, + **platform_config): + """ + namespace is used to force appending of a namespace to the tables. + existing namespaces are thus ignored. + + # This is the public facing interface, which internally uses + # _register_interface. + """ + interface_cls = Interface.get(interface_type) + if interface_cls is None: + log.warning("Could not create a %(interface_type)s interface" % \ + locals()) + return None + + try: + # passes a callback to the Interface + # no hook + platform_config['callback'] = self._on_receive + interface = interface_cls(self, **platform_config) + except Exception as e: + traceback.print_exc() + raise Exception("Cannot create interface %s of type %s with parameters %r: %s" + % (name, interface_type, + platform_config, e)) + self._register_interface(interface, name) + return interface + + def is_interface_up(self, interface_name): + interface = self._interfaces.get(interface_name) + if not interface: + return False + return self._interfaces[interface_name].is_up() + + def del_platform(self, platform_name, rebuild = True): + """ + Remove a platform from this Router. This platform is no more + registered. The corresponding Announces are also removed. + Args: + platform_name: A String containing a platform name. + rebuild: True if the DbGraph must be rebuild. + Returns: + True if it altered this Router. + """ + ret = False + try: + del self._interfaces[platform_name] + ret = True + except KeyError: + pass + + self.disable_platform(platform_name, rebuild) + return ret + + def get_interface(self, platform_name): + """ + Retrieve the Interface instance corresponding to a platform. + Args: + platform_name: A String containing the name of the platform. + Raises: + ValueError: if platform_name is invalid. + RuntimeError: in case of failure. + Returns: + The corresponding Interface if found, None otherwise. + """ + if platform_name.lower() != platform_name: + raise ValueError("Invalid platform_name = %s, must be lower case" \ + % platform_name) + + if platform_name in self._interfaces: + return self._interfaces[platform_name] + + raise RuntimeError("%s is not yet registered" % platform_name) + + def get_interface_names(self): + return self._interfaces.keys() + + def get_interfaces(self): + return self._interfaces.values() + + #-------------------------------------------------------------------------- + # Packet operations + #-------------------------------------------------------------------------- + + def _on_receive(self, packet, ingress_interface): + """Handles reception of a new packet. + + An incoming packet is forwarder either: + - using the reverse path is there is a match with the ingress + interface flow table + - using the FIB if no match is found + """ + orig_interface = self._flow_table.match(packet, ingress_interface) + if orig_interface: + orig_interface.send(packet) + return + + if isinstance(packet, str): + # Workaround : internal command + if self._vicn_callback: + self._vicn_callback(packet) + return + + if packet.source is None and packet.destination is None: + log.warning('TODO: handle NULL packet, need source on all packets') + return + + # Get route from FIB + interface = self._fib.get(packet.destination.object_name) + if not interface: + return + + # Update flow table before sending + self._flow_table.add(packet, ingress_interface, interface) + + interface.send(packet) |