У меня есть исходный код на Python, и я работаю в поле SDN, используя контроллер Ryu и mininet в качестве программы эмулятора. Тем не менее, я хочу установить правила потока в каждом переключателе. Таким образом, если пакет вставлен в s1, он будет перенаправлен через несколько коммутаторов на хост назначения в другом коммутаторе. Вопрос в том, как установить правила потока на основе алгоритмов маршрутизации?
У меня есть исходный код статической маршрутизации, скажите мне, где и что я должен изменить, чтобы применить разные алгоритмы маршрутизации через настройку правил потока в каждомswitch?
Любая помощь будет высоко оценена.
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> from ryu.base import app_manager from ryu.controller import ofp_event
> from ryu.controller.handler import CONFIG_DISPATCHER, MAIN_DISPATCHER
> from ryu.controller.handler import set_ev_cls from ryu.ofproto import
> ofproto_v1_3 from ryu.lib.packet import packet from ryu.lib.packet
> import ethernet from ryu.lib.packet import ether_types
class SimpleSwitch13(app_manager.RyuApp):
OFP_VERSIONS = [ofproto_v1_3.OFP_VERSION]
def __init__(self, *args, **kwargs):
super(SimpleSwitch13, self).__init__(*args, **kwargs)
self.mac_to_port = {}
@set_ev_cls(ofp_event.EventOFPSwitchFeatures, CONFIG_DISPATCHER)
def switch_features_handler(self, ev):
datapath = ev.msg.datapath
ofproto = datapath.ofproto
parser = datapath.ofproto_parser
# install table-miss flow entry
'''
match = parser.OFPMatch()
actions = [parser.OFPActionOutput(ofproto.OFPP_CONTROLLER,
ofproto.OFPCML_NO_BUFFER)]
self.add_flow(datapath, 0, match, actions)
'''
# switch s1
if datapath.id == 1:
# add group tables
self.send_group_mod(datapath)
actions = [parser.OFPActionGroup(group_id=50)]
match = parser.OFPMatch(in_port=3)
self.add_flow(datapath, 10, match, actions)
#add the return flow for h1 in s1.
# h1 is connected to port 3.
actions = [parser.OFPActionOutput(3)]
match = parser.OFPMatch(in_port=1)
self.add_flow(datapath, 10, match, actions)
actions = [parser.OFPActionOutput(3)]
match = parser.OFPMatch(in_port=2)
self.add_flow(datapath, 10, match, actions)
# switch s4
if datapath.id == 4:
# add group tables
self.send_group_mod(datapath)
actions = [parser.OFPActionGroup(group_id=50)]
match = parser.OFPMatch(in_port=3)
self.add_flow(datapath, 10, match, actions)
#add the return flow for h2 in s4.
# h2 is connected to port 3.
actions = [parser.OFPActionOutput(3)]
match = parser.OFPMatch(in_port=1)
self.add_flow(datapath, 10, match, actions)
actions = [parser.OFPActionOutput(3)]
match = parser.OFPMatch(in_port=2)
self.add_flow(datapath, 10, match, actions)
# switch s2
if datapath.id == 2:
# h1 is connected to port 3.
actions = [parser.OFPActionOutput(2)]
match = parser.OFPMatch(in_port=1)
self.add_flow(datapath, 10, match, actions)
actions = [parser.OFPActionOutput(1)]
match = parser.OFPMatch(in_port=2)
self.add_flow(datapath, 10, match, actions)
# switch s3
if datapath.id == 3:
# h1 is connected to port 3.
actions = [parser.OFPActionOutput(2)]
match = parser.OFPMatch(in_port=1)
self.add_flow(datapath, 10, match, actions)
actions = [parser.OFPActionOutput(1)]
match = parser.OFPMatch(in_port=2)
self.add_flow(datapath, 10, match, actions)
def add_flow(self, datapath, priority, match, actions, buffer_id=None):
ofproto = datapath.ofproto
parser = datapath.ofproto_parser
inst = [parser.OFPInstructionActions(ofproto.OFPIT_APPLY_ACTIONS,
actions)]
if buffer_id:
mod = parser.OFPFlowMod(datapath=datapath, buffer_id=buffer_id,
priority=priority, match=match,
instructions=inst)
else:
mod = parser.OFPFlowMod(datapath=datapath, priority=priority,
match=match, instructions=inst)
datapath.send_msg(mod)
@set_ev_cls(ofp_event.EventOFPPacketIn, MAIN_DISPATCHER)
def _packet_in_handler(self, ev):
# If you hit this you might want to increase
# the "miss_send_length" of your switch
if ev.msg.msg_len < ev.msg.total_len:
self.logger.debug("packet truncated: only %s of %s bytes",
ev.msg.msg_len, ev.msg.total_len)
msg = ev.msg
datapath = msg.datapath
ofproto = datapath.ofproto
parser = datapath.ofproto_parser
in_port = msg.match['in_port']
pkt = packet.Packet(msg.data)
eth = pkt.get_protocols(ethernet.ethernet)[0]
if eth.ethertype == ether_types.ETH_TYPE_LLDP:
# ignore lldp packet
return
dst = eth.dst
src = eth.src
dpid = datapath.id
if dst[:5] == "33:33":
self.logger.info("drop ipv6 multicast packet %s", dst)
return
self.mac_to_port.setdefault(dpid, {})
self.logger.info("packet in %s %s %s %s", dpid, src, dst, in_port)
# learn a mac address to avoid FLOOD next time.
self.mac_to_port[dpid][src] = in_port
if dst in self.mac_to_port[dpid]:
out_port = self.mac_to_port[dpid][dst]
else:
out_port = ofproto.OFPP_FLOOD
actions = [parser.OFPActionOutput(out_port)]
# install a flow to avoid packet_in next time
if out_port != ofproto.OFPP_FLOOD:
match = parser.OFPMatch(in_port=in_port, eth_dst=dst, eth_src=src)
# verify if we have a valid buffer_id, if yes avoid to send both
# flow_mod & packet_out
if msg.buffer_id != ofproto.OFP_NO_BUFFER:
self.add_flow(datapath, 1, match, actions, msg.buffer_id)
return
else:
self.add_flow(datapath, 1, match, actions)
data = None
if msg.buffer_id == ofproto.OFP_NO_BUFFER:
data = msg.data
out = parser.OFPPacketOut(datapath=datapath, buffer_id=msg.buffer_id,
in_port=in_port, actions=actions, data=data)
datapath.send_msg(out)
def send_group_mod(self, datapath):
ofproto = datapath.ofproto
parser = datapath.ofproto_parser
# Hardcoding the stuff, as we already know the topology diagram.
# Group table1
# Receiver port3 (host connected), forward it to port1(switch) and Port2(switch)
LB_WEIGHT1 = 30 #percentage
LB_WEIGHT2 = 70 #percentage
watch_port = ofproto_v1_3.OFPP_ANY
watch_group = ofproto_v1_3.OFPQ_ALL
actions1 = [parser.OFPActionOutput(1)]
actions2 = [parser.OFPActionOutput(2)]
buckets = [parser.OFPBucket(LB_WEIGHT1, watch_port, watch_group, actions=actions1),
parser.OFPBucket(LB_WEIGHT2, watch_port, watch_group, actions=actions2)]
req = parser.OFPGroupMod(datapath, ofproto.OFPGC_ADD,
ofproto.OFPGT_SELECT, 50, buckets)
datapath.send_msg(req)
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