class ARPTable(object):
MAX_ENTRIES = 1024
MAX_PENDING = 5
MAX_PENDING_TIME = 2
def __init__(self):
self.by_ip = {} # ip -> entry
self.pending = [] # Packets waiting to be sent (ip,(send_args))
self.timer = Timer(self.MAX_PENDING_TIME, self._timer_proc)
def __str__(self):
sending = set(x for x, y in self.pending)
r = []
for ip, e in sorted(self.by_ip.items()):
m = "%-15s %16s" % (ip, e.mac)
if ip in sending: m += " p"
r.append(m)
return "\n".join(r)
def add_entry(self, ip, mac=None):
"""
Add an entry
The entry can't already exist.
It will definitely exist after returning.
"""
assert ip not in self.by_ip
if len(self.by_ip) >= self.MAX_ENTRIES:
# Sloppy, but simple.
# Get ones with lowest age
entries = sorted(self.by_ip.values(), key=lambda entry: entry.age)
del entries[self.MAX_ENTRIES:]
self.by_ip = {e.mac: e for e in entries}
new_entry = ARPEntry(ip=ip, mac=mac)
self.by_ip[ip] = new_entry
return new_entry
def send(self,
eth_packet,
router_ip=None,
src_eth=None,
src_ip=None,
send_function=None):
"""
Try to send a packet
eth_packet is an ethernet object.
src_eth is the source for any ARPs sent.
src_ip is the source for any ARPs sent.
If the above two are not specified, they are taken from eth_packet.
send_function is a function which takes raw bytes to send.
If send_function is unset, it is taken from a send_function attribute.
"""
if send_function is None: send_function = self.send_function
ipp = eth_packet.find("ipv4")
if not ipp and eth_packet.type == eth_packet.IP_TYPE:
if isinstance(eth_packet.payload, bytes):
# Hm! Try harder...
ipp = pkt.ipv4(raw=eth_packet.payload)
if not ipp or eth_packet.dst.is_multicast:
send_function(eth_packet.pack())
return
if ipp.dstip == pkt.IPV4.IP_BROADCAST:
#ipp.dstip = router_ip # Not sure what this was about
eth_packet.dst = pkt.ETHERNET.ETHER_BROADCAST
send_function(eth_packet.pack())
return
if ipp.dstip.is_multicast:
eth_packet.dst = ipp.dstip.multicast_ethernet_address
send_function(eth_packet.pack())
return
if src_ip is None: src_ip = ipp.srcip
if src_eth is None: src_eth = eth_packet.src
if router_ip is not None: dstip = router_ip
else: dstip = ipp.dstip
if dstip not in self.by_ip: self.add_entry(dstip)
e = self.by_ip[dstip]
if e.maybe_refresh():
# Send ARP
self._send_arp(dstip, src_eth, src_ip, send_function)
if e.mac is not None:
eth_packet.dst = e.mac
send_function(eth_packet.pack())
else:
if len(self.pending) < self.MAX_PENDING:
self.pending.append((dstip, (eth_packet, router_ip, src_eth,
src_ip, send_function)))
def _timer_proc(self):
# We just blow away all the entries every interval, so on average, they
# live for half the interval.
del self.pending[:]
def __del__(self):
if self.timer:
self.timer.cancel()
self.timer = None
def _send_arp(self, dstip, src_eth, src_ip, send_function):
r = pkt.arp()
r.opcode = r.REQUEST
r.hwdst = pkt.ETHERNET.ETHER_BROADCAST
r.protodst = dstip
r.hwsrc = src_eth
r.protosrc = src_ip
e = pkt.ethernet(type=pkt.ethernet.ARP_TYPE, src=r.hwsrc, dst=r.hwdst)
e.payload = r
log.debug("Sending ARP for %s", dstip)
send_function(e.pack())
def rx_arp_reply(self, arp):
assert arp.opcode == arp.REPLY
self.rx_arp(arp)
def rx_arp(self, arp):
if arp.protosrc not in self.by_ip:
self.add_entry(mac=arp.hwsrc, ip=arp.protosrc)
else:
self.by_ip[arp.protosrc].confirm(arp.hwsrc)
# Send any pending packets
for index, (ip, args) in reversed(list(enumerate(self.pending))):
if ip == arp.protosrc:
del self.pending[index]
log.debug("ARP reply allows sending pending packet")
self.send(*args)
class AbstractRemoteDomainManager(AbstractDomainManager):
"""
Abstract class for different remote domain managers.
Implement polling mechanism for remote domains.
"""
# Polling interval
POLL_INTERVAL = 3
"""Polling interval"""
# Request formats
DEFAULT_DIFF_VALUE = False
"""Request formats"""
def __init__(self, domain_name=None, adapters=None, **kwargs):
"""
Init.
:param domain_name: domain name
:type domain_name: str
:param adapters: config of adapters
:type adapters: dict
:param kwargs: optional params
:type kwargs: dict
:return: None
"""
super(AbstractRemoteDomainManager,
self).__init__(domain_name=domain_name,
adapters=adapters,
**kwargs)
# Timer for polling function
self.__timer = None
if 'poll' in kwargs:
self._poll = bool(kwargs['poll'])
else:
self._poll = False
if 'diff' in kwargs:
self._diff = bool(kwargs['diff'])
else:
self._diff = self.DEFAULT_DIFF_VALUE
self.log.debug("Enforced configuration for %s: poll: %s, diff: %s" %
(self.__class__.__name__, self._poll, self._diff))
@property
def detected(self):
"""
Return True if the Manager has detected the domain.
:return: domain status
:rtype: bool
"""
return self._detected
def get_domain_url(self):
if isinstance(self.topoAdapter, AbstractRESTAdapter):
return self.topoAdapter.URL
##############################################################################
# Abstract functions for component control
##############################################################################
def init(self, configurator, **kwargs):
"""
Abstract function for component initialization.
:param configurator: component configurator for configuring adapters
:type configurator: :any:`ComponentConfigurator`
:param kwargs: optional parameters
:type kwargs: dict
:return: None
"""
# Load and initiate adapters using the initiate_adapters() template func
self._load_adapters(configurator=configurator, **kwargs)
# Skip to start polling if it's set
if not self._poll:
# Try to request/parse/update Mininet topology
if not self._detect_topology():
self.log.warning("%s domain not confirmed during init!" %
self.domain_name)
else:
# Notify all components for topology change --> this event causes
# the DoV updating
self.raiseEventNoErrors(
DomainChangedEvent,
domain=self.domain_name,
data=self.internal_topo,
cause=DomainChangedEvent.TYPE.DOMAIN_UP)
else:
self.log.info("Start polling %s domain..." % self.domain_name)
self.start_polling(self.POLL_INTERVAL)
def initiate_adapters(self, configurator):
"""
Initiate Adapters for DomainManager.
Must override in inherited classes.
Follows the Factory Method design pattern.
:param configurator: component configurator for configuring adapters
:type configurator: :any:`ComponentConfigurator`
:return: None
"""
raise NotImplementedError
def finit(self):
"""
Abstract function for starting component.
:return: None
"""
self.stop_polling()
super(AbstractRemoteDomainManager, self).finit()
##############################################################################
# Common functions for polling
##############################################################################
def start_polling(self, interval=1):
"""
Initialize and start a Timer co-op task for polling.
:param interval: polling period (default: 1)
:type interval: int
:return: None
"""
if self.__timer:
# Already timing
return
self.__timer = Timer(interval,
self.poll,
recurring=True,
started=True,
selfStoppable=True)
def restart_polling(self, interval=POLL_INTERVAL):
"""
Reinitialize and start a Timer co-op task for polling.
:param interval: polling period (default: 3)
:type interval: int
:return: None
"""
if self.__timer:
self.__timer.cancel()
self.__timer = Timer(interval,
self.poll,
recurring=True,
started=True,
selfStoppable=True)
def stop_polling(self):
"""
Stop timer.
:return: None
"""
if self.__timer:
self.__timer.cancel()
self.__timer = None
@property
def polling(self):
return self._poll
def poll(self):
"""
Poll the defined domain agent. Handle different connection errors and go
to slow/rapid poll. When an agent is (re)detected update the current
resource information.
:return: None
"""
# If domain is not detected
if not self._detected:
# Check the topology is reachable
if self._detect_topology():
# Domain is detected and topology is updated -> restart domain polling
self.restart_polling()
# Notify all components for topology change --> this event causes
# the DoV updating
self.raiseEventNoErrors(
DomainChangedEvent,
domain=self.domain_name,
data=self.internal_topo,
cause=DomainChangedEvent.TYPE.DOMAIN_UP)
return
# If domain has already detected
else:
# Check the domain is still reachable
changed = self.topoAdapter.check_topology_changed()
# No changes
if changed is False:
# Nothing to do
self.log.log(
VERBOSE,
"Remote domain: %s has not changed!" % self.domain_name)
return
# Domain has changed
elif isinstance(changed, NFFG):
self.log.info("Remote domain: %s has changed! "
"Update global domain view..." %
self.domain_name)
self.log.debug("Save changed topology: %s" % changed)
# Update the received new topo
self.internal_topo = changed
# Notify all components for topology change --> this event causes
# the DoV updating
self.raiseEventNoErrors(
DomainChangedEvent,
domain=self.domain_name,
data=self.internal_topo,
cause=DomainChangedEvent.TYPE.DOMAIN_CHANGED)
return
# If changed is None something went wrong, probably remote domain is not
# reachable. Step to the other half of the function
elif changed is None:
self.log.warning("Lost connection with %s agent! "
"Going to slow poll..." % self.domain_name)
# Clear internal topology
self.log.debug("Clear topology from domain: %s" %
self.domain_name)
self.internal_topo = None
self.raiseEventNoErrors(
DomainChangedEvent,
domain=self.domain_name,
cause=DomainChangedEvent.TYPE.DOMAIN_DOWN)
else:
self.log.warning(
"Got unexpected return value from check_topology_changed(): %s"
% type(changed))
return
# If this is the first call of poll()
if self._detected is None:
self.log.warning("Local agent in domain: %s is not detected! "
"Keep trying..." % self.domain_name)
self._detected = False
elif self._detected:
# Detected before -> lost connection = big Problem
self._detected = False
self.restart_polling()
else:
# No success but not for the first try -> keep trying silently
pass
##############################################################################
# ESCAPE specific functions
##############################################################################
def install_nffg(self, nffg_part):
"""
Install an :class:`NFFG` related to the specific domain.
:raise: :any:`exceptions.NotImplementedError`
:param nffg_part: NF-FG need to be deployed
:type nffg_part: :class:`NFFG`
:return: status if the install process was success
:rtype: bool
"""
raise NotImplementedError
def clear_domain(self):
"""
Clear the Domain according to the first received config.
:raise: :any:`exceptions.NotImplementedError`
:return: None
"""
raise NotImplementedError
class MulticastPath(object):
"""Manages multicast route calculation and installation for a single pair of multicast group and multicast sender."""
def __init__(self, src_ip, src_router_dpid, ingress_port, dst_mcast_address, groupflow_manager, groupflow_trace_event = None):
self.src_ip = src_ip
self.ingress_port = ingress_port
self.src_router_dpid = src_router_dpid
self.dst_mcast_address = dst_mcast_address
self.path_tree_map = defaultdict(lambda : None) # self.path_tree_map[router_dpid] = Complete path from receiver router_dpid to src
self.weighted_topo_graph = []
self.node_list = [] # List of all managed router dpids
self.installed_node_list = [] # List of all router dpids with rules currently installed
self.receivers = [] # Tuples of (router_dpid, port)
self.groupflow_manager = groupflow_manager
self.flow_cookie = self.groupflow_manager.get_new_mcast_group_cookie()
self.calc_path_tree_dijkstras(groupflow_trace_event)
self._last_flow_replacement_time = None
self._flow_replacement_timer = None
def calc_path_tree_dijkstras(self, groupflow_trace_event = None):
"""Calculates a shortest path tree from the group sender to all network switches, and caches the resulting tree.
Note that this function does not install any flow modifications."""
if not groupflow_trace_event is None:
groupflow_trace_event.set_tree_calc_start_time(self.dst_mcast_address, self.src_ip)
self._last_flow_replacement_time = time.time()
self._calc_link_weights()
nodes = set(self.node_list)
edges = self.weighted_topo_graph
graph = defaultdict(list)
for src,dst,cost in edges:
graph[src].append((cost, dst))
path_tree_map = defaultdict(lambda : None)
queue, seen = [(0,self.src_router_dpid,())], set()
while queue:
(cost,node1,path) = heappop(queue)
if node1 not in seen:
seen.add(node1)
path = (node1, path)
path_tree_map[node1] = path
for next_cost, node2 in graph.get(node1, ()):
if node2 not in seen:
new_path_cost = cost + next_cost
heappush(queue, (new_path_cost, node2, path))
self.path_tree_map = path_tree_map
log.debug('Calculated shortest path tree for source at router_dpid: ' + dpid_to_str(self.src_router_dpid))
for node in self.path_tree_map:
log.debug('Path to Node ' + dpid_to_str(node) + ': ' + str(self.path_tree_map[node]))
if not groupflow_trace_event is None:
groupflow_trace_event.set_tree_calc_end_time()
def _calc_link_weights(self):
"""Calculates link weights for all links in the network to be used by calc_path_tree_dijkstras().
The cost assigned to each link is based on the link's current utilization (as determined by the FlowTracker
module), and the exact manner in which utilization is converted to a link wieght is determined by
groupflow_manager.link_weight_type. Valid options are LINK_WEIGHT_LINEAR and LINK_WEIGHT_EXPONENTIAL. Both options
include a static weight which is always assigned to all links (determined by groupflow_manager.static_link_weight),
and a dynamic weight which is based on the current utilization (determined by
groupflow_manager.utilization_link_weight). Setting groupflow_manager.utilization_link_weight to 0 will always
results in shortest hop routing.
"""
curr_topo_graph = self.groupflow_manager.topology_graph
self.node_list = list(self.groupflow_manager.node_set)
weighted_topo_graph = []
current_util = core.openflow_flow_tracker.get_max_flow_utilization(self.flow_cookie) / core.openflow_flow_tracker.link_max_bw
log.info('Current utilization of flow ' + str(self.flow_cookie) + ': ' + str(current_util * core.openflow_flow_tracker.link_max_bw) + ' Mbps')
for edge in curr_topo_graph:
output_port = self.groupflow_manager.adjacency[edge[0]][edge[1]]
raw_link_util = core.openflow_flow_tracker.get_link_utilization_normalized(edge[0], output_port);
link_util_mcast_flow = core.openflow_flow_tracker.get_flow_utilization_normalized(edge[0], output_port, self.flow_cookie)
link_util = max(0, (raw_link_util * (1 - link_util_mcast_flow)))
# link_util = raw_link_util # Uncommenting this line will cause flows to reroute around their own traffic, good for testing
# Current utilization here is doubled as a simple attempt to handle variability in flow rates
if link_util + (current_util * 2) > 1:
link_util = 1
link_weight = 1
if self.groupflow_manager.util_link_weight == 0:
link_weight = self.groupflow_manager.static_link_weight
else:
if self.groupflow_manager.link_weight_type == LINK_WEIGHT_LINEAR:
if link_util >= 1:
link_weight = sys.float_info.max / core.openflow_flow_tracker.get_num_tracked_links()
else:
link_weight = min(self.groupflow_manager.static_link_weight + (self.groupflow_manager.util_link_weight * link_util),
sys.float_info.max / core.openflow_flow_tracker.get_num_tracked_links())
elif self.groupflow_manager.link_weight_type == LINK_WEIGHT_EXPONENTIAL:
if link_util >= 1:
link_weight = sys.float_info.max / core.openflow_flow_tracker.get_num_tracked_links()
else:
link_weight = min(self.groupflow_manager.static_link_weight + (self.groupflow_manager.util_link_weight * ((1 / (1 - link_util)) - 1)),
sys.float_info.max / core.openflow_flow_tracker.get_num_tracked_links())
log.debug('Router DPID: ' + dpid_to_str(edge[0]) + ' Port: ' + str(output_port) +
' TotalUtil: ' + str(raw_link_util) + ' FlowUtil: ' + str(link_util_mcast_flow) + ' OtherFlowUtil: ' + str(link_util)
+ ' Weight: ' + str(link_weight))
weighted_topo_graph.append([edge[0], edge[1], link_weight])
self.weighted_topo_graph = weighted_topo_graph
log.debug('Calculated link weights for source at router_dpid: ' + dpid_to_str(self.src_router_dpid))
for edge in self.weighted_topo_graph:
log.debug(dpid_to_str(edge[0]) + ' -> ' + dpid_to_str(edge[1]) + ' W: ' + str(edge[2]))
def install_openflow_rules(self, groupflow_trace_event = None):
"""Selects routes for active receivers from the cached shortest path tree, and installs/removes OpenFlow rules accordingly."""
reception_state = self.groupflow_manager.get_reception_state(self.dst_mcast_address, self.src_ip)
log.debug('Reception state for ' + str(self.dst_mcast_address) + ': ' + str(reception_state))
outgoing_rules = defaultdict(lambda : None)
if not groupflow_trace_event is None:
groupflow_trace_event.set_route_processing_start_time(self.dst_mcast_address, self.src_ip)
# Calculate the paths for the specific receivers that are currently active from the previously
# calculated mst
edges_to_install = []
calculated_path_router_dpids = []
for receiver in reception_state:
if receiver[0] == self.src_router_dpid:
continue
if receiver[0] in calculated_path_router_dpids:
continue
# log.debug('Building path for receiver on router: ' + dpid_to_str(receiver[0]))
receiver_path = self.path_tree_map[receiver[0]]
log.debug('Receiver path for receiver ' + str(receiver[0]) + ': ' + str(receiver_path))
if receiver_path is None:
log.warn('Path could not be determined for receiver ' + dpid_to_str(receiver[0]) + ' (network is not fully connected)')
continue
while receiver_path[1]:
edges_to_install.append((receiver_path[1][0], receiver_path[0]))
receiver_path = receiver_path[1]
calculated_path_router_dpids.append(receiver[0])
# Get rid of duplicates in the edge list (must be a more efficient way to do this, find it eventually)
edges_to_install = list(Set(edges_to_install))
if not edges_to_install is None:
# log.info('Installing edges:')
for edge in edges_to_install:
log.debug('Installing: ' + str(edge[0]) + ' -> ' + str(edge[1]))
if not groupflow_trace_event is None:
groupflow_trace_event.set_route_processing_end_time()
groupflow_trace_event.set_flow_installation_start_time()
for edge in edges_to_install:
if edge[0] in outgoing_rules:
# Add the output action to an existing rule if it has already been generated
output_port = self.groupflow_manager.adjacency[edge[0]][edge[1]]
outgoing_rules[edge[0]].actions.append(of.ofp_action_output(port = output_port))
#log.debug('ER: Configured router ' + dpid_to_str(edge[0]) + ' to forward group ' + \
# str(self.dst_mcast_address) + ' to next router ' + \
# dpid_to_str(edge[1]) + ' over port: ' + str(output_port))
else:
# Otherwise, generate a new flow mod
msg = of.ofp_flow_mod()
msg.hard_timeout = 0
msg.idle_timeout = 0
if edge[0] in self.installed_node_list:
msg.command = of.OFPFC_MODIFY
else:
msg.command = of.OFPFC_ADD
msg.match.dl_type = 0x800 # IPV4
msg.match.nw_dst = self.dst_mcast_address
msg.match.nw_src = self.src_ip
msg.cookie = self.flow_cookie
output_port = self.groupflow_manager.adjacency[edge[0]][edge[1]]
msg.actions.append(of.ofp_action_output(port = output_port))
outgoing_rules[edge[0]] = msg
#log.debug('NR: Configured router ' + dpid_to_str(edge[0]) + ' to forward group ' + \
# str(self.dst_mcast_address) + ' to next router ' + \
# dpid_to_str(edge[1]) + ' over port: ' + str(output_port))
for receiver in reception_state:
if receiver[0] in outgoing_rules:
# Add the output action to an existing rule if it has already been generated
output_port = receiver[1]
outgoing_rules[receiver[0]].actions.append(of.ofp_action_output(port = output_port))
#log.debug('ER: Configured router ' + dpid_to_str(receiver[0]) + ' to forward group ' + \
# str(self.dst_mcast_address) + ' to network over port: ' + str(output_port))
else:
# Otherwise, generate a new flow mod
msg = of.ofp_flow_mod()
msg.hard_timeout = 0
msg.idle_timeout = 0
if receiver[0] in self.installed_node_list:
msg.command = of.OFPFC_MODIFY
else:
msg.command = of.OFPFC_ADD
msg.cookie = self.flow_cookie
msg.match.dl_type = 0x800 # IPV4
msg.match.nw_dst = self.dst_mcast_address
msg.match.nw_src = self.src_ip
output_port = receiver[1]
msg.actions.append(of.ofp_action_output(port = output_port))
outgoing_rules[receiver[0]] = msg
#log.debug('NR: Configured router ' + dpid_to_str(receiver[0]) + ' to forward group ' + \
# str(self.dst_mcast_address) + ' to network over port: ' + str(output_port))
# Setup empty rules for any router not involved in this path
for router_dpid in self.node_list:
if not router_dpid in outgoing_rules and router_dpid in self.installed_node_list:
msg = of.ofp_flow_mod()
msg.cookie = self.flow_cookie
msg.match.dl_type = 0x800 # IPV4
msg.match.nw_dst = self.dst_mcast_address
msg.match.nw_src = self.src_ip
msg.command = of.OFPFC_DELETE
outgoing_rules[router_dpid] = msg
#log.debug('Removed rule on router ' + dpid_to_str(router_dpid) + ' for group ' + str(self.dst_mcast_address))
for router_dpid in outgoing_rules:
connection = core.openflow.getConnection(router_dpid)
if connection is not None:
connection.send(outgoing_rules[router_dpid])
if not outgoing_rules[router_dpid].command == of.OFPFC_DELETE:
self.installed_node_list.append(router_dpid)
else:
self.installed_node_list.remove(router_dpid)
else:
log.warn('Could not get connection for router: ' + dpid_to_str(router_dpid))
log.debug('New flows installed for Group: ' + str(self.dst_mcast_address) + ' Source: ' + str(self.src_ip) + ' FlowCookie: ' + str(self.flow_cookie))
if self.groupflow_manager.flow_replacement_mode == PERIODIC_FLOW_REPLACEMENT and self._flow_replacement_timer is None:
log.debug('Starting flow replacement timer for Group: ' + str(self.dst_mcast_address) + ' Source: ' + str(self.src_ip) + ' FlowCookie: ' + str(self.flow_cookie))
self._flow_replacement_timer = Timer(self.groupflow_manager.flow_replacement_interval, self.update_flow_placement, recurring=True)
if not groupflow_trace_event is None:
groupflow_trace_event.set_flow_installation_end_time()
core.groupflow_event_tracer.archive_trace_event(groupflow_trace_event)
def remove_openflow_rules(self):
"""Removes all OpenFlow rules associated with this multicast group / sender pair.
This should be used when the group has no active receivers."""
log.info('Removing rules on all routers for Group: ' + str(self.dst_mcast_address) + ' Source: ' + str(self.src_ip))
for router_dpid in self.node_list:
msg = of.ofp_flow_mod()
msg.cookie = self.flow_cookie
msg.match.dl_type = 0x800 # IPV4
msg.match.nw_dst = self.dst_mcast_address
msg.match.nw_src = self.src_ip
msg.match.in_port = None
msg.command = of.OFPFC_DELETE
connection = core.openflow.getConnection(router_dpid)
if connection is not None:
connection.send(msg)
else:
log.warn('Could not get connection for router: ' + dpid_to_str(router_dpid))
self.installed_node_list = []
if self._flow_replacement_timer is not None:
self._flow_replacement_timer.cancel()
self._flow_replacement_timer = None
def update_flow_placement(self, groupflow_trace_event = None):
"""Replaces the existing flows by recalculating the cached shortest path tree, and installing new OpenFlow rules."""
self.calc_path_tree_dijkstras(groupflow_trace_event)
self.install_openflow_rules(groupflow_trace_event)
log.info('Replaced flows for Group: ' + str(self.dst_mcast_address) + ' Source: ' + str(self.src_ip) + ' FlowCookie: ' + str(self.flow_cookie))
class MulticastPath(object):
"""Manages multicast route calculation and installation for a single pair of multicast group and multicast sender."""
def __init__(self, src_ip, src_router_dpid, ingress_port, dst_mcast_address, groupflow_manager, groupflow_trace_event = None):
self.src_ip = src_ip
self.ingress_port = ingress_port
self.src_router_dpid = src_router_dpid
self.dst_mcast_address = dst_mcast_address
self.path_tree_map = defaultdict(lambda : None) # self.path_tree_map[router_dpid] = Complete path from receiver router_dpid to src
self.weighted_topo_graph = []
self.node_list = [] # List of all managed router dpids
self.installed_node_list = [] # List of all router dpids with rules currently installed
self.receivers = [] # Tuples of (router_dpid, port)
self.groupflow_manager = groupflow_manager
self.flow_cookie = self.groupflow_manager.get_new_mcast_group_cookie()
self.calc_path_tree_dijkstras(groupflow_trace_event)
self._last_flow_replacement_time = None
self._flow_replacement_timer = None
def calc_path_tree_dijkstras(self, groupflow_trace_event = None):
"""Calculates a shortest path tree from the group sender to all network switches, and caches the resulting tree.
Note that this function does not install any flow modifications."""
if not groupflow_trace_event is None:
groupflow_trace_event.set_tree_calc_start_time(self.dst_mcast_address, self.src_ip)
self._last_flow_replacement_time = time.time()
self._calc_link_weights()
nodes = set(self.node_list)
edges = self.weighted_topo_graph
graph = defaultdict(list)
for src,dst,cost in edges:
graph[src].append((cost, dst))
path_tree_map = defaultdict(lambda : None)
queue, seen = [(0,self.src_router_dpid,())], set()
while queue:
(cost,node1,path) = heappop(queue)
if node1 not in seen:
seen.add(node1)
path = (node1, path)
path_tree_map[node1] = path
for next_cost, node2 in graph.get(node1, ()):
if node2 not in seen:
new_path_cost = cost + next_cost
heappush(queue, (new_path_cost, node2, path))
self.path_tree_map = path_tree_map
log.debug('Calculated shortest path tree for source at router_dpid: ' + dpid_to_str(self.src_router_dpid))
for node in self.path_tree_map:
log.debug('Path to Node ' + dpid_to_str(node) + ': ' + str(self.path_tree_map[node]))
if not groupflow_trace_event is None:
groupflow_trace_event.set_tree_calc_end_time()
def _calc_link_weights(self):
"""Calculates link weights for all links in the network to be used by calc_path_tree_dijkstras().
The cost assigned to each link is based on the link's current utilization (as determined by the FlowTracker
module), and the exact manner in which utilization is converted to a link wieght is determined by
groupflow_manager.link_weight_type. Valid options are LINK_WEIGHT_LINEAR and LINK_WEIGHT_EXPONENTIAL. Both options
include a static weight which is always assigned to all links (determined by groupflow_manager.static_link_weight),
and a dynamic weight which is based on the current utilization (determined by
groupflow_manager.utilization_link_weight). Setting groupflow_manager.utilization_link_weight to 0 will always
results in shortest hop routing.
"""
curr_topo_graph = self.groupflow_manager.topology_graph
self.node_list = list(self.groupflow_manager.node_set)
weighted_topo_graph = []
current_util = core.openflow_flow_tracker.get_max_flow_utilization(self.flow_cookie) / core.openflow_flow_tracker.link_max_bw
log.info('Current utilization of flow ' + str(self.flow_cookie) + ': ' + str(current_util * core.openflow_flow_tracker.link_max_bw) + ' Mbps')
for edge in curr_topo_graph:
output_port = self.groupflow_manager.adjacency[edge[0]][edge[1]]
raw_link_util = core.openflow_flow_tracker.get_link_utilization_normalized(edge[0], output_port);
link_util_mcast_flow = core.openflow_flow_tracker.get_flow_utilization_normalized(edge[0], output_port, self.flow_cookie)
link_util = max(0, (raw_link_util * (1 - link_util_mcast_flow)))
# link_util = raw_link_util # Uncommenting this line will cause flows to reroute around their own traffic, good for testing
# Current utilization here is doubled as a simple attempt to handle variability in flow rates
if link_util + (current_util * 2) > 1:
link_util = 1
link_weight = 1
if self.groupflow_manager.util_link_weight == 0:
link_weight = self.groupflow_manager.static_link_weight
else:
if self.groupflow_manager.link_weight_type == LINK_WEIGHT_LINEAR:
if link_util >= 1:
link_weight = sys.float_info.max / core.openflow_flow_tracker.get_num_tracked_links()
else:
link_weight = min(self.groupflow_manager.static_link_weight + (self.groupflow_manager.util_link_weight * link_util),
sys.float_info.max / core.openflow_flow_tracker.get_num_tracked_links())
elif self.groupflow_manager.link_weight_type == LINK_WEIGHT_EXPONENTIAL:
if link_util >= 1:
link_weight = sys.float_info.max / core.openflow_flow_tracker.get_num_tracked_links()
else:
link_weight = min(self.groupflow_manager.static_link_weight + (self.groupflow_manager.util_link_weight * ((1 / (1 - link_util)) - 1)),
sys.float_info.max / core.openflow_flow_tracker.get_num_tracked_links())
log.debug('Router DPID: ' + dpid_to_str(edge[0]) + ' Port: ' + str(output_port) +
' TotalUtil: ' + str(raw_link_util) + ' FlowUtil: ' + str(link_util_mcast_flow) + ' OtherFlowUtil: ' + str(link_util)
+ ' Weight: ' + str(link_weight))
weighted_topo_graph.append([edge[0], edge[1], link_weight])
self.weighted_topo_graph = weighted_topo_graph
log.debug('Calculated link weights for source at router_dpid: ' + dpid_to_str(self.src_router_dpid))
for edge in self.weighted_topo_graph:
log.debug(dpid_to_str(edge[0]) + ' -> ' + dpid_to_str(edge[1]) + ' W: ' + str(edge[2]))
def install_openflow_rules(self, groupflow_trace_event = None):
"""Selects routes for active receivers from the cached shortest path tree, and installs/removes OpenFlow rules accordingly."""
reception_state = self.groupflow_manager.get_reception_state(self.dst_mcast_address, self.src_ip)
log.debug('Reception state for ' + str(self.dst_mcast_address) + ': ' + str(reception_state))
outgoing_rules = defaultdict(lambda : None)
if not groupflow_trace_event is None:
groupflow_trace_event.set_route_processing_start_time(self.dst_mcast_address, self.src_ip)
# Calculate the paths for the specific receivers that are currently active from the previously
# calculated mst
edges_to_install = []
calculated_path_router_dpids = []
for receiver in reception_state:
if receiver[0] == self.src_router_dpid:
continue
if receiver[0] in calculated_path_router_dpids:
continue
# log.debug('Building path for receiver on router: ' + dpid_to_str(receiver[0]))
receiver_path = self.path_tree_map[receiver[0]]
log.debug('Receiver path for receiver ' + str(receiver[0]) + ': ' + str(receiver_path))
if receiver_path is None:
log.warn('Path could not be determined for receiver ' + dpid_to_str(receiver[0]) + ' (network is not fully connected)')
continue
while receiver_path[1]:
edges_to_install.append((receiver_path[1][0], receiver_path[0]))
receiver_path = receiver_path[1]
calculated_path_router_dpids.append(receiver[0])
# Get rid of duplicates in the edge list (must be a more efficient way to do this, find it eventually)
edges_to_install = list(Set(edges_to_install))
if not edges_to_install is None:
# log.info('Installing edges:')
for edge in edges_to_install:
log.debug('Installing: ' + str(edge[0]) + ' -> ' + str(edge[1]))
if not groupflow_trace_event is None:
groupflow_trace_event.set_route_processing_end_time()
groupflow_trace_event.set_flow_installation_start_time()
for edge in edges_to_install:
if edge[0] in outgoing_rules:
# Add the output action to an existing rule if it has already been generated
output_port = self.groupflow_manager.adjacency[edge[0]][edge[1]]
outgoing_rules[edge[0]].actions.append(of.ofp_action_output(port = output_port))
#log.debug('ER: Configured router ' + dpid_to_str(edge[0]) + ' to forward group ' + \
# str(self.dst_mcast_address) + ' to next router ' + \
# dpid_to_str(edge[1]) + ' over port: ' + str(output_port))
else:
# Otherwise, generate a new flow mod
msg = of.ofp_flow_mod()
msg.hard_timeout = 0
msg.idle_timeout = 0
if edge[0] in self.installed_node_list:
msg.command = of.OFPFC_MODIFY
else:
msg.command = of.OFPFC_ADD
msg.match.dl_type = 0x800 # IPV4
msg.match.nw_dst = self.dst_mcast_address
msg.match.nw_src = self.src_ip
msg.cookie = self.flow_cookie
output_port = self.groupflow_manager.adjacency[edge[0]][edge[1]]
msg.actions.append(of.ofp_action_output(port = output_port))
outgoing_rules[edge[0]] = msg
#log.debug('NR: Configured router ' + dpid_to_str(edge[0]) + ' to forward group ' + \
# str(self.dst_mcast_address) + ' to next router ' + \
# dpid_to_str(edge[1]) + ' over port: ' + str(output_port))
for receiver in reception_state:
if receiver[0] in outgoing_rules:
# Add the output action to an existing rule if it has already been generated
output_port = receiver[1]
outgoing_rules[receiver[0]].actions.append(of.ofp_action_output(port = output_port))
#log.debug('ER: Configured router ' + dpid_to_str(receiver[0]) + ' to forward group ' + \
# str(self.dst_mcast_address) + ' to network over port: ' + str(output_port))
else:
# Otherwise, generate a new flow mod
msg = of.ofp_flow_mod()
msg.hard_timeout = 0
msg.idle_timeout = 0
if receiver[0] in self.installed_node_list:
msg.command = of.OFPFC_MODIFY
else:
msg.command = of.OFPFC_ADD
msg.cookie = self.flow_cookie
msg.match.dl_type = 0x800 # IPV4
msg.match.nw_dst = self.dst_mcast_address
msg.match.nw_src = self.src_ip
output_port = receiver[1]
msg.actions.append(of.ofp_action_output(port = output_port))
outgoing_rules[receiver[0]] = msg
#log.debug('NR: Configured router ' + dpid_to_str(receiver[0]) + ' to forward group ' + \
# str(self.dst_mcast_address) + ' to network over port: ' + str(output_port))
# Setup empty rules for any router not involved in this path
for router_dpid in self.node_list:
if not router_dpid in outgoing_rules and router_dpid in self.installed_node_list:
msg = of.ofp_flow_mod()
msg.cookie = self.flow_cookie
msg.match.dl_type = 0x800 # IPV4
msg.match.nw_dst = self.dst_mcast_address
msg.match.nw_src = self.src_ip
msg.command = of.OFPFC_DELETE
outgoing_rules[router_dpid] = msg
#log.debug('Removed rule on router ' + dpid_to_str(router_dpid) + ' for group ' + str(self.dst_mcast_address))
for router_dpid in outgoing_rules:
connection = core.openflow.getConnection(router_dpid)
if connection is not None:
connection.send(outgoing_rules[router_dpid])
if not outgoing_rules[router_dpid].command == of.OFPFC_DELETE:
self.installed_node_list.append(router_dpid)
else:
self.installed_node_list.remove(router_dpid)
else:
log.warn('Could not get connection for router: ' + dpid_to_str(router_dpid))
log.debug('New flows installed for Group: ' + str(self.dst_mcast_address) + ' Source: ' + str(self.src_ip) + ' FlowCookie: ' + str(self.flow_cookie))
if self.groupflow_manager.flow_replacement_mode == PERIODIC_FLOW_REPLACEMENT and self._flow_replacement_timer is None:
log.debug('Starting flow replacement timer for Group: ' + str(self.dst_mcast_address) + ' Source: ' + str(self.src_ip) + ' FlowCookie: ' + str(self.flow_cookie))
self._flow_replacement_timer = Timer(self.groupflow_manager.flow_replacement_interval, self.update_flow_placement, recurring=True)
if not groupflow_trace_event is None:
groupflow_trace_event.set_flow_installation_end_time()
core.groupflow_event_tracer.archive_trace_event(groupflow_trace_event)
def remove_openflow_rules(self):
"""Removes all OpenFlow rules associated with this multicast group / sender pair.
This should be used when the group has no active receivers."""
log.info('Removing rules on all routers for Group: ' + str(self.dst_mcast_address) + ' Source: ' + str(self.src_ip))
for router_dpid in self.node_list:
msg = of.ofp_flow_mod()
msg.cookie = self.flow_cookie
msg.match.dl_type = 0x800 # IPV4
msg.match.nw_dst = self.dst_mcast_address
msg.match.nw_src = self.src_ip
msg.match.in_port = None
msg.command = of.OFPFC_DELETE
connection = core.openflow.getConnection(router_dpid)
if connection is not None:
connection.send(msg)
else:
log.warn('Could not get connection for router: ' + dpid_to_str(router_dpid))
self.installed_node_list = []
if self._flow_replacement_timer is not None:
self._flow_replacement_timer.cancel()
self._flow_replacement_timer = None
def update_flow_placement(self, groupflow_trace_event = None):
"""Replaces the existing flows by recalculating the cached shortest path tree, and installing new OpenFlow rules."""
self.calc_path_tree_dijkstras(groupflow_trace_event)
self.install_openflow_rules(groupflow_trace_event)
log.info('Replaced flows for Group: ' + str(self.dst_mcast_address) + ' Source: ' + str(self.src_ip) + ' FlowCookie: ' + str(self.flow_cookie))
class TestController(object):
def __init__(self, connection):
self.connected = True
self.connection = connection
self.counter = 0
self.listeners = []
log.debug('connection: ')
log.debug(self.connection)
self.listeners = connection.addListeners(self)
def _send_random_flow():
if not self.connected:
return False
log.debug('-- Sending random flow --')
# Creates an open flow rule which should send PILO broadcast messages
# to our handler
delete_msg = of.ofp_flow_mod()
delete_msg.command = of.OFPFC_DELETE
delete_msg.match.priority = self.counter
delete_msg.match.dl_type = pkt.ethernet.IP_TYPE
delete_msg.match.nw_proto = pkt.ipv4.UDP_PROTOCOL
delete_msg.match.nw_dst = IPAddr('100.100.100.100')
self.connection.send(delete_msg)
self.counter += 1
random_flow = of.ofp_flow_mod()
random_flow.priority = self.counter
random_flow.match.dl_type = pkt.ethernet.IP_TYPE
random_flow.match.nw_proto = pkt.ipv4.UDP_PROTOCOL
random_flow.match.nw_dst = IPAddr('100.100.100.100')
random_flow.actions.append(
of.ofp_action_output(port=of.OFPP_CONTROLLER))
self.connection.send(random_flow)
self.timer = Timer(10, _send_random_flow, recurring=True)
_send_random_flow()
def _handle_PacketIn(self, event):
"""
Handles packet in messages from a remote pilo switch.
"""
log.debug(' -- Received Packet in in test controller -- \n\n')
log.debug(event)
packet = event.parsed # This is the parsed packet data.
log.debug(packet)
if not packet.parsed:
log.warning("Ignoring incomplete packet")
return
packet_in = event.ofp # The actual ofp_packet_in message.
log.debug(packet_in)
log.debug(' -- Received Packet in in test controller -- \n\n')
def _handle_ConnectionDown(self, event):
log.debug('test controller handle connection down')
self.connected = False
self.timer.cancel()
self.connection.removeListeners(self.listeners)
