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#
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you 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.
#
from data import MessageRA, MessageLSU, MessageLSR
from time import time
try:
from dispatch import *
except ImportError:
from stubs import *
class LinkStateEngine(object):
"""
This module is responsible for running the Link State protocol and maintaining the set
of link states that are gathered from the domain. It notifies outbound when changes to
the link-state-collection are detected.
"""
def __init__(self, container):
self.container = container
self.id = self.container.id
self.area = self.container.area
self.ra_interval = self.container.config.ra_interval
self.remote_ls_max_age = self.container.config.remote_ls_max_age
self.last_ra_time = 0
self.collection = {}
self.collection_changed = False
self.mobile_seq = 0
self.needed_lsrs = {}
def tick(self, now):
self._expire_ls(now)
self._send_lsrs()
if now - self.last_ra_time >= self.ra_interval:
self.last_ra_time = now
self._send_ra()
if self.collection_changed:
self.collection_changed = False
self.container.log(LOG_INFO, "New Link-State Collection:")
for a,b in self.collection.items():
self.container.log(LOG_INFO, " %s => %r" % (a, b.peers))
self.container.ls_collection_changed(self.collection)
def handle_ra(self, msg, now):
if msg.id == self.id:
return
if msg.id in self.collection:
ls = self.collection[msg.id]
ls.last_seen = now
if ls.ls_seq < msg.ls_seq:
self.needed_lsrs[(msg.area, msg.id)] = None
else:
self.needed_lsrs[(msg.area, msg.id)] = None
def handle_lsu(self, msg, now):
if msg.id == self.id:
return
if msg.id in self.collection:
ls = self.collection[msg.id]
if ls.ls_seq < msg.ls_seq:
ls = msg.ls
self.collection[msg.id] = ls
self.collection_changed = True
ls.last_seen = now
else:
ls = msg.ls
self.collection[msg.id] = ls
self.collection_changed = True
ls.last_seen = now
self.container.new_node(msg.id)
self.container.log(LOG_INFO, "Learned link-state from new router: %s" % msg.id)
# Schedule LSRs for any routers referenced in this LS that we don't know about
for _id in msg.ls.peers:
if _id not in self.collection:
self.needed_lsrs[(msg.area, _id)] = None
def handle_lsr(self, msg, now):
if msg.id == self.id:
return
if self.id not in self.collection:
return
my_ls = self.collection[self.id]
self.container.send('_topo/%s/%s' % (msg.area, msg.id), MessageLSU(None, self.id, self.area, my_ls.ls_seq, my_ls))
def new_local_link_state(self, link_state):
self.collection[self.id] = link_state
self.collection_changed = True
self._send_ra()
def set_mobile_sequence(self, seq):
self.mobile_seq = seq
def get_collection(self):
return self.collection
def _expire_ls(self, now):
to_delete = []
for key, ls in self.collection.items():
if key != self.id and now - ls.last_seen > self.remote_ls_max_age:
to_delete.append(key)
for key in to_delete:
ls = self.collection.pop(key)
self.collection_changed = True
self.container.lost_node(key)
self.container.log(LOG_INFO, "Expired link-state from router: %s" % key)
def _send_lsrs(self):
for (_area, _id) in self.needed_lsrs.keys():
self.container.send('_topo/%s/%s' % (_area, _id), MessageLSR(None, self.id, self.area))
self.needed_lsrs = {}
def _send_ra(self):
ls_seq = 0
if self.id in self.collection:
ls_seq = self.collection[self.id].ls_seq
self.container.send('_topo/%s/all' % self.area, MessageRA(None, self.id, self.area, ls_seq, self.mobile_seq))
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