class DtnAbstractDuct(Simulable, metaclass=abc.ABCMeta):
""" An abstract duct. It operates 2 queues:
1) in_queue: Queue where all bundles to be sent are placed.
2) to_limbo: Queue where bundles that fail to be sent by the
convergence layer are placed. The ``fail_manager``
function in this class takes them an puts them in
the node's limbo queue for re-routing.
"""
duct_type = None
def __init__(self, env, name, parent, neighbor):
super(DtnAbstractDuct, self).__init__(env)
self.base_name = name # See network architecture file (xml)
self.parent = parent # DtnNode
self.neighbor = neighbor # A string with the name of the neighbor
self.monitor = self.env.monitor
# Connection through which data is sent
#self.conn = env.connections[parent.nid, neighbor]
# Add the queue for the convergence layer. DTN does not control it and
# therefore it is assumed to be plain FIFO
self.in_queue = DtnQueue(env)
# Queue to store messages that were not successfully sent by the duct
# and thus must be sent to the node's limbo
self.to_limbo = DtnQueue(self.env)
# Queue to store messages that were successfully sent by the duct
self.success_queue = DtnQueue(self.env)
def initialize(self, peer, **kwargs):
# Peer duct (for an outduct it is an induct and vice versa)
self.peer = peer
# Activate the process for this convergence layer
self.env.process(self.run())
# Run the fail manager that returns bundles that failed to be sent for
# re-routers
self.env.process(self.fail_manager())
# Run the success manager
self.env.process(self.success_manager())
@property
def is_alive(self):
return self.parent.is_alive
@abc.abstractmethod
def total_datarate(self, dest):
pass
@property
def transmit_mode(self):
return 'fwd' if self.duct_type == 'outduct' else 'ack'
@property
def name(self):
return '{} {} ({}-{})'.format(self.__class__.__name__, self.base_name,
self.parent.nid, self.neighbor)
@property
def stored(self):
return self.in_queue.stored
@property
@abc.abstractmethod
def radios(self):
""" Returns a dictionary with the radios for this duct """
pass
def send(self, message):
""" Pass a message to the duct for transmission
This is a non-blocking call.
"""
self.env.process(self.do_send(message))
def do_send(self, message):
# Add to the queue
self.disp('{} delivered to {}', message, self.__class__.__name__)
yield from self.in_queue.put(message)
@abc.abstractmethod
def run(self):
pass
def ack(self, message):
""" This is called by a DtnConnection if you transmit something an specify direction
equals "ack". It is more general than LTP, it is a generic mechanism to communicate
"backwards" between two ducts (from rx's induct to tx's outduct) and no go through
the in_queue (that takes message from the upper layer)
"""
self.env.process(self.do_ack(message))
def do_ack(self, message):
""" A duct, by default should not be able to perform ack. See DtnOutductLTP for an example
of implementation
"""
# Fake yield to ensure this is a coroutine
yield self.env.timeout(0)
# This is not allowed unless this function is re-implemented
# See DtnOutductLTP and DtnInductLTP for an example of how to use it
raise RuntimeError('You cannot ACK in this convergence layer')
def notify_success(self, message):
self.env.process(self.do_notify_success(message))
def do_notify_success(self, message):
yield from self.success_queue.put(message)
def success_manager(self):
while self.is_alive:
# Wait for a block that was successfully transmitted
# Do nothing in the default implementation. Just here to
# prevent the queue from filling indefinitely
yield from self.success_queue.get()
@abc.abstractmethod
def radio_error(self, message):
""" This function signals an LTP session that it needs to terminate because an error
has occurred in the radio. The ``fail_manager`` will then be responsible to put
the corresponding bundles to the node's limbo.
"""
pass
def fail_manager(self):
while self.is_alive:
# Wait for a block that was not successfully transmitted
# by an LTP session
bundle = yield from self.to_limbo.get()
# Get the cid that needs to be excluded. This is not very neat, but
# essentially reaches into the current DtnNeighborManager for this
# neighbor and pulls the contact id
cid = self.parent.queues[self.neighbor].current_cid
# Send to node's limbo for re-routers
self.parent.limbo(bundle, cid)
class DtnEpidemicManager(Simulable):
def __init__(self, env, parent, params):
# Call parent constructor
super().__init__(env)
# Store the node that contains this manager, it is a DtnNode
self.parent = parent
# Create a queue that can be locked and set the capacity to the specified value
self.queue = DtnMaxCapacityQueue(env, parent, params.max_buffer_size)
# Handshake queue
self.handshake_queue = DtnQueue(env)
# Lock to ensure that all operations related to putting one bundle in
# the queue are "atomic"
self.put_lock = DtnLock(env)
# Get all connections possible for this node
self.cons = {
d: c
for (o, d), c in self.env.connections.items()
if o == self.parent.nid
}
# Create an engine for each connection in the system
for dest, con in self.cons.items():
# Process to get elements out of the queue to transmit
env.process(self.queue_extractor(dest, con))
@property
def is_alive(self):
return self.parent.is_alive
def put(self, rt_record, priority):
self.env.process(self.do_put(rt_record, priority))
def do_put(self, rt_record, priority):
# Only one bundle can be put into the queue at a time. Otherwise, you
# have race conditions (e.g. you make room for a bundle but before you
# actually get put in queue someone else takes your room)
yield self.put_lock.acquire()
# Put the bundle in the queue. Bundles that where used to make ro
to_drop = yield from self.queue.put(rt_record, priority, where='left')
# Drop bundles
for rt_record in to_drop:
self.parent.drop(rt_record.bundle,
drop_reason='Opportunistic queue full')
# Release the lock to signal that another bundle can start the process
# of getting added to the queue
self.put_lock.release()
def queue_extractor(self, dest, conn):
while self.is_alive:
# Wait until the next connection starts
if conn.is_red: yield conn.green
# Handshake with other node see which data is missing on other node
# NOTE: This is a blocking call since you cannot do the rest until
# this is completed.
to_send = yield from self.do_handshake(dest, conn)
# If the connection red again, continue
if conn.is_red: continue
# Send all data that was flagged as missing in the other node
for rt_record in to_send:
# Log and monitor exit of bundle
self.disp('{} departs from the manager', rt_record.bundle)
# Send this bundle towards the convergence layer
self.send(dest, rt_record)
# If the connection red again, continue
if conn.is_red: continue
# Wait until connection ends
if conn.is_green: yield conn.red
def send(self, dest, rt_record):
self.parent.forward_to_outduct(dest, rt_record)
def do_handshake(self, dest, conn):
# Gather list of all bundles you have
bids = tuple(self.queue.keys())
# Create a bundle
bnd = Bundle(self.env,
self.parent.nid,
dest,
'telemetry',
16 + 8 * len(bids),
1,
False,
eid=1)
# Add the data to this bundle
bnd.data = bids
# Get a new routing record. 1 = critical priority
rt_record = self.parent.router.new_record(bnd, 1)
# Send this record
self.send(dest, rt_record)
# Wait until either the connection ends or you receive the response
# of the handshaking mechanism
yield conn.red | self.handshake_queue.is_empty()
# If the connections is red, then the handshake has failed
if conn.is_red: return
# Get the bundle from the peer
bnd = yield from self.handshake_queue.get()
print('hola')
class DtnBasicRadio(DtnAbstractRadio):
def __init__(self, env, parent, shared=True):
# Call parent constructor
super(DtnBasicRadio, self).__init__(env, parent, shared)
# Create input queue
self.in_queue = DtnQueue(env)
@property
def stored(self):
df = self.in_queue.stored
df['where'] = 'radio'
return df
def initialize(self, rate=0, BER=0, J_bit=0, **kwargs):
# Store configuration parameters
self.datarate = rate
self.BER = BER
self.J_bit = J_bit
# Call parent initializer
super(DtnBasicRadio, self).initialize()
def do_put(self, neighbor, message, peer, direction):
# Create item to send
item = (neighbor, message, peer, direction)
# Add it to the queue
yield from self.in_queue.put(item)
def run(self, **kwargs):
while self.is_alive:
# Get the next segment to transmit
item = yield from self.in_queue.get()
# Depack item
neighbor, message, peer, direction = item
# Get the connection to send this message through
conn = self.outcons[neighbor]
# Compute total transmission time
Ttx = message.num_bits/self.datarate
# Apply delay for radio to transmit entire segment
yield self.env.timeout(Ttx)
# Count the energy consumed
self.energy += message.num_bits * self.J_bit
# Transmit the message through the connection.
self.send_through_connection(message, conn, peer, direction)
def send_through_connection(self, message, conn, peer, direction):
""" Send a message through a connection
:param Message message: The message to send
:param conn: The connection to send the message through
:param peer: The peer duct that will receive the message
:param str direction: 'fwd' vs. 'ack'. By default 'fwd', use 'ack'
for the acknowledgement messages of protocols
like LTP (from dest to origin).
"""
# This is a non-blocking call since the bundle is out in transit
conn.transmit(peer, message, self.BER, direction=direction)
class DtnNode(Simulable):
def __init__(self, env, nid, props):
super().__init__(env)
# Initialize node properties
self.nid = nid
self.type = env.config['network'].nodes[nid].type
self.alias = env.config['network'].nodes[nid].alias
self.props = props
# Initialize variables
self.generators = {} # Map: {generator type: Generator class}
self.queues = {} # Map: {neighbor id: DtnNeighborManager}
self.neighbors = [] # List of neighbors as specified in config file
self.radios = {} # Map: {radio id: Radio class}
self.endpoints = {} # Map: {eid: Endpoint class}
# Convergence layers. This is a map of map of maps of the following form
# {neighbor id: duct id: induct/ouduct: DtnAbstractDuct subclass}
self.ducts = defaultdict(lambda: defaultdict(dict))
# Queue to store all bundles that are waiting to be forwarded
self.in_queue = DtnQueue(env)
# Queue for the limbo
self.limbo_queue = DtnQueue(env)
# Create variables to store results
self.dropped = []
def reset(self):
# Reset node elements
self.router.reset()
self.selector.reset()
for _, gen in self.generators.items():
gen.reset()
for _, radio in self.radios.items():
radio.reset()
@property
def available_radios(self):
return self.radios
def initialize(self):
""" Initialize the node. Note that his can only be done after the connections
have been created.
"""
self.mobility_model = self.env.mobility_models[
self.props.mobility_model]
# Initialize bundle generators for this node
self.initialize_bundle_generators()
# Initialize the band selector
self.initialize_outduct_selector()
# Initialize radios. Note: This must be done prior to initializing
# the ducts since ducts require radios. Ducts are initialized in the
# environment.
self.initialize_radios()
# Now that you have created everything, start the forward and limbo managers
self.env.process(self.forward_manager())
self.env.process(self.limbo_manager())
def initialize_bundle_generators(self):
# Initialize variables
config = self.env.config
# Get the list of generators for this node
gens = config[self.type].generators
# Instantiate generators dynamically based on class name
for gen in gens:
clazz = getattr(config[gen], 'class')
module = importlib.import_module(f'simulator.generators.{clazz}')
clazz = getattr(module, clazz)
# Create the generator
self.generators[gen] = clazz(self.env, self, config[gen])
# Initialize the generator
self.generators[gen].initialize()
def initialize_router(self):
# Initialize variables
config = self.env.config
# Get type of router for this node
router_type = config[self.type].router
# Instantiate generators dynamically based on class name
clazz = load_class_dynamically('simulator.routers',
getattr(config[router_type], 'class'))
self.router = clazz(self.env, self)
# Initialize this router
self.router.initialize()
# If this router is not opportunistic, you are done
if not self.router.opportunistic: return
# If this is an opportunistic router, then a specialized queue
# manager is needed.
clazz = load_class_dynamically('simulator.nodes',
config[router_type].manager)
self.queues['opportunistic'] = clazz(self.env, self,
config[router_type])
def initialize_outduct_selector(self):
# Initialize variables
config = self.env.config
# Get type of router for this node
selector_type = config[self.type].selector
# Instantiate generators dynamically based on class name
clazz = getattr(config[selector_type], 'class')
module = importlib.import_module(f'simulator.selectors.{clazz}')
clazz = getattr(module, clazz)
self.selector = clazz(self.env, self)
# Initialize this router
self.selector.initialize()
def initialize_radios(self):
# Iterate over the radios
for radio in self.props.radios:
# Create the radio for this duct
class_name = getattr(self.config[radio], 'class')
clazz = load_class_dynamically('simulator.radios', class_name)
# Get properties
radio_props = dict(self.config[radio])
# Store the new radio
self.radios[radio] = clazz(self.env, self)
# Initialize the radio
self.radios[radio].initialize(**radio_props)
def initialize_neighbors_and_ducts(self):
# Iterate over all neighbors
for orig, neighbor in self.env.connections.keys():
# If this is not the right origin, continue
if orig != self.nid: continue
# Store this neighbor
self.neighbors.append(neighbor)
# Create and store the priority queue for this neighbor
self.queues[neighbor] = DtnCgrNeighborManager(
self.env, self, neighbor)
# Get the neighbor node and the connection between them
other = self.env.nodes[neighbor]
conn = self.env.connections[self.nid, neighbor]
# Iterate over defined ducts and create them
for duct_id, duct_name in self.env.config[conn.type].ducts.items():
# Get the properties of this duct
props = self.env.config[duct_name]
# Initialize variables
iduct, oduct = None, None
# Create the induct and outduct
for class_name in getattr(props, 'class'):
# Load class type. Since you can't know if it is an induct or outduct,
# try both.
try:
clazz = load_class_dynamically(
'simulator.ducts.inducts', class_name)
except ModuleNotFoundError:
clazz = load_class_dynamically(
'simulator.ducts.outducts', class_name)
# Construct depending on whether it is an induct or outduct
if clazz.duct_type == None:
raise RuntimeError(
f'{clazz} has no duct_type defined. Is it an induct or outduct?'
)
elif clazz.duct_type == 'outduct':
oduct = clazz(self.env, duct_id, self, neighbor)
elif clazz.duct_type == 'induct':
iduct = clazz(self.env, duct_id, other, orig)
else:
raise RuntimeError(
'f{clazz} has duct_type = {clazz.duct_type}. Valid options are "induct" and '
'"outduct"')
# If either the ouduct or induct are not set, throw error
if iduct == None or oduct == None:
raise RuntimeError('Could not create duct f{duct_id}')
# Store the newly created ducts
self.ducts[neighbor][duct_id]['outduct'] = oduct
other.ducts[orig][duct_id]['induct'] = iduct
# Iterate over defined ducts and initialize them. This is done separately
# since you need to have created all ducts to initialize them for ParallelLTP
for duct_id, duct_name in self.env.config[conn.type].ducts.items():
# Get the properties of this duct
props = self.env.config[duct_name]
oduct = self.ducts[neighbor][duct_id]['outduct']
iduct = other.ducts[orig][duct_id]['induct']
# Initialize duct parameters. Initialization must happen after creating the ducts
# since they must point to each other.
oduct.initialize(iduct, **dict(props))
iduct.initialize(oduct, **dict(props))
# For now, assume that there is no need for an opportunistic queue.
# If so, it will be initialized with the router.
self.queues['opportunistic'] = None
def initialize_endpoints(self):
# Add any additional endpoints
for eid, ept_class in self.props.endpoints.items():
# Handle special case for default endpoint
if eid == 0:
self.endpoints[eid] = DtnDefaultEndpoint(self.env, self)
self.endpoints[eid].initialize()
continue
# Find the endpoint type
clazz = load_class_dynamically('simulator.endpoints', ept_class)
# Store the new endpoint
self.endpoints[eid] = clazz(self.env, self)
# Initialize endpoint
if eid in self.config:
self.endpoints[eid].initialize(**dict(self.config[eid]))
else:
self.endpoints[eid].initialize()
def initialize_neighbor_managers(self):
for neighbor, mgr in self.queues.items():
if neighbor.lower() == 'opportunistic':
continue
mgr.initialize()
def forward_manager(self):
""" This agent pulls bundles from the node incoming queue for processing.
It ensures that this happens one at a time following the order in which
they are added to the queue. Note that both new bundles and bundles awaiting
re-routers will be directed to the ``in_queue`` (see ``forward`` vs ``limbo``)
"""
# Iterate forever looking for new bundles to forward
while self.is_alive:
# Wait until there is a bundle to process
item = yield from self.in_queue.get()
# Depack item
bundle, first_time = item[0], item[1]
# Trigger forwarding mechanism. If you add a delay in the forwarding mechanism,
# this delay will be preserved here. To have non-blocking behavior, use
# ``self.env.process(self.process_bundle(item[0], first_time=item[1])``
self.process_bundle(bundle, first_time=first_time)
def process_bundle(self, bundle, first_time=True):
""" Process this bundle in the node. This entails:
1) If this node is the destination, you are done
2) Otherwise, route the bundle
3) If no routes are available, drop
4) Otherwise, put the bundle into one or more neighbor queues to await transmission by
the corresponding convergence layer
:param bundle: The bundle to forward
:param first_time: True if this is the first time this node sees this bundle
"""
# If this bundle has errors, drop immediately
if bundle.has_errors:
self.drop(bundle, 'error')
return
# It this bundle exceeds the TTL, drop
if self.check_bundle_TTL(bundle):
return
# Add this node in the list of visited nodes (NOTE: must be done before ``find_routes``)
if first_time: bundle.visited.append(self.nid)
# Reset the list of excluded contacts
if first_time: bundle.excluded = []
# If bundle has reached destination, simply store
if bundle.dest == self.nid:
self.arrive(bundle)
return
# Get contacts for this bundle
records_to_fwd, cids_to_exclude = self.router.find_routes(
bundle, first_time)
# If router asks for limbo, send this bundle there
if records_to_fwd == 'limbo':
self.limbo(bundle, cids_to_exclude)
return
# If you can neither forward nor re-route, then drop
if not records_to_fwd and not cids_to_exclude:
self.drop(bundle, 'unroutable')
return
# If the router has indicated to drop, do it
if records_to_fwd == 'drop':
self.drop(bundle, 'router_drops')
return
for record in records_to_fwd:
# Log this successful routers event
self.disp('{} is routed towards {}', record.bundle,
record.contact['dest'])
# Get the record to forward. If critical and first time, deepcopy it
to_fwd = deepcopy(
record) if bundle.critical and first_time else record
# Pass the bundle to the appropriate neighbor manager
self.store_routed_bundle(to_fwd)
# If you have forwarded at least once, you are done
if records_to_fwd: return
# Trigger re-routers excluding the appropriate contacts
self.limbo(bundle, cids_to_exclude)
def store_routed_bundle(self, rt_record):
# Get the neighbor node to send to
neighbor = rt_record.neighbor
# Put in the queue
self.queues[neighbor].put(rt_record, rt_record.priority)
def forward_to_outduct(self, neighbor, rt_record):
""" Called whenever a bundle successfully exits a DtnNeighborManager """
# Initialize variables
bundle = rt_record.bundle
# Get the outduct for this bundle
duct = self.selector.select_duct(neighbor, bundle)
# If bundle TTL is exceeded, do not forward
if self.check_bundle_TTL(bundle):
return
# Put bundle in the convergence layer
duct['outduct'].send(bundle)
def forward(self, bundle):
""" Put a bundle in the queue of bundles to route. Forward should be used
the first time that you route a bundle. For bundles that are being
re-routed, use ``limbo`` instead
.. Tip:: This function never blocks despite the ``yield from`` because
the input queue has infinite capacity
"""
self.env.process(self.do_forward(bundle))
def do_forward(self, bundle):
yield from self.in_queue.put((bundle, True))
def limbo(self, bundle, contact_ids):
""" Put a bundle in the queue of bundles to route (this bundle is re-routed
and thus this is equivalent to ION's limbo). Add the provided contacts
as excluded since you already tried to send this bundle through them
.. Tip:: This function never blocks despite the ``yield from`` because
the input queue has infinite capacity
"""
# HACK: If contact_ids is None, try re-routing again
if contact_ids is not None:
if not isinstance(contact_ids, (list, tuple)):
contact_ids = (contact_ids, )
bundle.excluded.extend(contact_ids)
self.env.process(self.do_limbo(bundle))
def do_limbo(self, bundle):
# If you do not have a limbo wait finite, wait for a second here.
# Otherwise you will try to re-route the bundle at the same instant
# in time, thus creating an infinite loop
if self.props.limbo_wait == float('inf'):
yield self.env.timeout(1)
# Add to the limbo queue
yield from self.limbo_queue.put((bundle, False))
def limbo_manager(self):
# Initialize variables
dt = self.props.limbo_wait
# if dt = inf, then you want to pause the limbo until there
# is something in it
check_empty = dt == float('inf')
while self.is_alive:
# Wait for a while. Only do this if you specified a rate at
# which to pull from the queue
if not check_empty: yield self.env.timeout(dt)
# Get everything from the queue
items = yield from self.limbo_queue.get_all(
check_empty=check_empty)
# Put all items in the input queue
for item in items:
yield from self.in_queue.put(item)
def check_bundle_TTL(self, bundle):
if self.t - bundle.creation_time < bundle.TTL:
return False
# Drop the bundle
self.drop(bundle, f'TTL (t={self.t})')
return True
def arrive(self, bundle):
# If node is not alive, delete
if not self.is_alive:
self.drop(bundle, 'dead_node')
# Mark arrival
self.disp('{} arrives at destination', bundle)
bundle.arrived = True
bundle.arrival_time = self.t
bundle.latency = bundle.arrival_time - bundle.creation_time
# Dispatch bundle to the appropriate endpoint depending on the bundle EID
self.endpoints[bundle.eid].put(bundle)
def drop(self, bundle, drop_reason):
self.disp('{} is dropped at node {}', bundle, self.nid)
bundle.dropped = True
bundle.drop_reason = drop_reason
self.dropped.append(bundle)
def radio_error(self, message):
self.disp('Error in radio')
def __str__(self):
return '<DtnNode {}>'.format(self.nid)