ryu/build/lib.linux-armv7l-2.7/ryu/app/example_switch_13.py

   1 # Copyright (C) 2016 Nippon Telegraph and Telephone Corporation.
   2 #
   3 # Licensed under the Apache License, Version 2.0 (the "License");
   4 # you may not use this file except in compliance with the License.
   5 # You may obtain a copy of the License at
   6 #
   7 #    http://www.apache.org/licenses/LICENSE-2.0
   8 #
   9 # Unless required by applicable law or agreed to in writing, software
  10 # distributed under the License is distributed on an "AS IS" BASIS,
  11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
  12 # implied.
  13 # See the License for the specific language governing permissions and
  14 # limitations under the License.
  15
  16 from ryu.base import app_manager
  17 from ryu.controller import ofp_event
  18 from ryu.controller.handler import CONFIG_DISPATCHER, MAIN_DISPATCHER
  19 from ryu.controller.handler import set_ev_cls
  20 from ryu.ofproto import ofproto_v1_3
  21 from ryu.lib.packet import packet
  22 from ryu.lib.packet import ethernet
  23
  24
  25 class ExampleSwitch13(app_manager.RyuApp):
  26     OFP_VERSIONS = [ofproto_v1_3.OFP_VERSION]
  27
  28     def __init__(self, *args, **kwargs):
  29         super(ExampleSwitch13, self).__init__(*args, **kwargs)
  30         # initialize mac address table.
  31         self.mac_to_port = {}
  32
  33     @set_ev_cls(ofp_event.EventOFPSwitchFeatures, CONFIG_DISPATCHER)
  34     def switch_features_handler(self, ev):
  35         datapath = ev.msg.datapath
  36         ofproto = datapath.ofproto
  37         parser = datapath.ofproto_parser
  38
  39         # install the table-miss flow entry.
  40         match = parser.OFPMatch()
  41         actions = [parser.OFPActionOutput(ofproto.OFPP_CONTROLLER,
  42                                           ofproto.OFPCML_NO_BUFFER)]
  43         self.add_flow(datapath, 0, match, actions)
  44
  45     def add_flow(self, datapath, priority, match, actions):
  46         ofproto = datapath.ofproto
  47         parser = datapath.ofproto_parser
  48
  49         # construct flow_mod message and send it.
  50         inst = [parser.OFPInstructionActions(ofproto.OFPIT_APPLY_ACTIONS,
  51                                              actions)]
  52         mod = parser.OFPFlowMod(datapath=datapath, priority=priority,
  53                                 match=match, instructions=inst)
  54         datapath.send_msg(mod)
  55
  56     @set_ev_cls(ofp_event.EventOFPPacketIn, MAIN_DISPATCHER)
  57     def _packet_in_handler(self, ev):
  58         msg = ev.msg
  59         datapath = msg.datapath
  60         ofproto = datapath.ofproto
  61         parser = datapath.ofproto_parser
  62
  63         # get Datapath ID to identify OpenFlow switches.
  64         dpid = datapath.id
  65         self.mac_to_port.setdefault(dpid, {})
  66
  67         # analyse the received packets using the packet library.
  68         pkt = packet.Packet(msg.data)
  69         eth_pkt = pkt.get_protocol(ethernet.ethernet)
  70         dst = eth_pkt.dst
  71         src = eth_pkt.src
  72
  73         # get the received port number from packet_in message.
  74         in_port = msg.match['in_port']
  75
  76         self.logger.info("packet in %s %s %s %s", dpid, src, dst, in_port)
  77
  78         # learn a mac address to avoid FLOOD next time.
  79         self.mac_to_port[dpid][src] = in_port
  80
  81         # if the destination mac address is already learned,
  82         # decide which port to output the packet, otherwise FLOOD.
  83         if dst in self.mac_to_port[dpid]:
  84             out_port = self.mac_to_port[dpid][dst]
  85         else:
  86             out_port = ofproto.OFPP_FLOOD
  87
  88         # construct action list.
  89         actions = [parser.OFPActionOutput(out_port)]
  90
  91         # install a flow to avoid packet_in next time.
  92         if out_port != ofproto.OFPP_FLOOD:
  93             match = parser.OFPMatch(in_port=in_port, eth_dst=dst)
  94             self.add_flow(datapath, 1, match, actions)
  95
  96         # construct packet_out message and send it.
  97         out = parser.OFPPacketOut(datapath=datapath,
  98                                   buffer_id=ofproto.OFP_NO_BUFFER,
  99                                   in_port=in_port, actions=actions,
 100                                   data=msg.data)
 101         datapath.send_msg(out)