+# Copyright (C) 2011 Nippon Telegraph and Telephone Corporation.
+#
+# Licensed 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 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
+from ryu.topology.event import EventSwitchEnter, EventSwitchLeave, EventSwitchReconnected
+
+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
+ #
+ # We specify NO BUFFER to max_len of the output action due to
+ # OVS bug. At this moment, if we specify a lesser number, e.g.,
+ # 128, OVS will send Packet-In with invalid buffer_id and
+ # truncated packet data. In that case, we cannot output packets
+ # correctly. The bug has been fixed in OVS v2.1.0.
+ match = parser.OFPMatch()
+ actions = [parser.OFPActionOutput(ofproto.OFPP_CONTROLLER,
+ ofproto.OFPCML_NO_BUFFER)]
+ self.add_flow(datapath, 0, 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)
+
+ # new switch detected
+
+ @set_ev_cls([EventSwitchEnter, EventSwitchReconnected])
+ def _ev_switch_enter_handler(self, ev):
+ datapath = ev.switch.dp
+ self.logger.info('registered OF switch id: %s' % datapath.id)
+ ofproto = datapath.ofproto
+ self.logger.info('OF version: {0}'.format(ofproto))
+ # send NORMAL action for all undefined flows
+ ofp_parser = datapath.ofproto_parser
+ actions = [ofp_parser.OFPActionOutput(ofproto_v1_3.OFPP_NORMAL)]
+ self.add_flow(datapath, 0, None, actions)
+
+
+ @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
+ 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)
+ # 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)