def as_flow_mod(self, flow_type=FlowModCommand.OFPFC_ADD):
"""Transform a Flow object into a flow_mod message.
Args:
flow_type (|flow_mod_command|):
type of flow_mod to be converted.
Returns:
|flow_mod|: Instance of FlowMod with Flow attributes.
"""
flow_mod = FlowMod()
flow_mod.command = flow_type
flow_mod_attributes = [
'buffer_id', 'idle_timeout', 'hard_timeout', 'priority'
]
for attribute_name in flow_mod_attributes:
value = getattr(self, attribute_name)
if value is not None:
setattr(flow_mod, attribute_name, value)
flow_mod.match = Match()
match_attributes = [
'in_port', 'dl_src', 'dl_dst', 'dl_vlan', 'dl_type', 'nw_src',
'nw_dst', 'tp_dst'
]
for attribute_name in match_attributes:
value = getattr(self, attribute_name)
if value is not None:
setattr(flow_mod.match, attribute_name, value)
if self.actions is not None:
for action in self.actions:
flow_mod.actions.append(action.as_of_action())
return flow_mod
def handle_packet_in(self, event):
"""Handle PacketIn Event.
Install flows allowing communication between switch ports.
Args:
event (KytosPacketIn): Received Event
"""
log.debug("PacketIn Received")
packet_in = event.content['message']
ethernet = Ethernet()
ethernet.unpack(packet_in.data.value)
# Ignore LLDP packets or packets not generated by table-miss flows
if (ethernet.destination in settings.lldp_macs
or packet_in.reason != PacketInReason.OFPR_NO_MATCH):
return
# Learn the port where the sender is connected
in_port = packet_in.in_port.value
switch = event.source.switch
switch.update_mac_table(ethernet.source, in_port)
ports = switch.where_is_mac(ethernet.destination)
# Add a flow to the switch if the destination is known
if ports:
flow_mod = FlowMod()
flow_mod.command = FlowModCommand.OFPFC_ADD
flow_mod.match = Match()
flow_mod.match.dl_src = ethernet.source.value
flow_mod.match.dl_dst = ethernet.destination.value
flow_mod.match.dl_type = ethernet.ether_type
flow_mod.actions.append(ActionOutput(port=ports[0]))
event_out = KytosEvent(name=('kytos/of_l2ls.messages.out.'
'ofpt_flow_mod'),
content={
'destination': event.source,
'message': flow_mod
})
self.controller.buffers.msg_out.put(event_out)
# Send the packet to correct destination or flood it
packet_out = PacketOut()
packet_out.buffer_id = packet_in.buffer_id
packet_out.in_port = packet_in.in_port
packet_out.data = packet_in.data
port = ports[0] if ports else Port.OFPP_FLOOD
packet_out.actions.append(ActionOutput(port=port))
event_out = KytosEvent(name=('kytos/of_l2ls.messages.out.'
'ofpt_packet_out'),
content={
'destination': event.source,
'message': packet_out
})
self.controller.buffers.msg_out.put(event_out)
def ipv6_drop(self, event):
"""Install a flow on the switch that drop all incoming ipv6 packets."""
switch = event.content['switch']
if switch.connection.protocol.version is not 0x01:
return
flow_mod = FlowMod()
flow_mod.command = FlowModCommand.OFPFC_ADD
flow_mod.match = Match()
flow_mod.match.dl_type = 0x86dd # ipv6
event_out = KytosEvent(name=('kytos/of_ipv6drop.messages.out.'
'ofpt_flow_mod'),
content={'destination': switch.connection,
'message': flow_mod})
log.info('Sending "IPv6 DROP" flow to switch %s', switch.id)
self.controller.buffers.msg_out.put(event_out)