import json
from ryu.app import simple_switch_13
from ryu.controller import ofp_event
from ryu.controller.handler import CONFIG_DISPATCHER
from ryu.controller.handler import set_ev_cls
from ryu.app.wsgi import ControllerBase
from ryu.app.wsgi import Response
from ryu.app.wsgi import route
from ryu.app.wsgi import WSGIApplication
from ryu.lib import dpid as dpid_lib

simple_switch_instance_name = ‘simple_switch_api_app‘
url = ‘/simpleswitch/mactable/{dpid}‘


class SimpleSwitchRest13(simple_switch_13.SimpleSwitch13):
    _CONTEXTS = {‘wsgi‘: WSGIApplication}

    def __init__(self, *args, **kwargs):
        super(SimpleSwitchRest13, self).__init__(*args, **kwargs)
        self.switches = {}
        wsgi = kwargs[‘wsgi‘]
        wsgi.register(SimpleSwitchController,
                      {simple_switch_instance_name: self})

    @set_ev_cls(ofp_event.EventOFPSwitchFeatures, CONFIG_DISPATCHER)
    def switch_features_handler(self, ev):
        super(SimpleSwitchRest13, self).switch_features_handler(ev)
        datapath = ev.msg.datapath
        self.switches[datapath.id] = datapath
        self.mac_to_port.setdefault(datapath.id, {})

    def set_mac_to_port(self, dpid, entry):
        mac_table = self.mac_to_port.setdefault(dpid, {})
        datapath = self.switches.get(dpid)

        entry_port = entry[‘port‘]
        entry_mac = entry[‘mac‘]

        if datapath is not None:
            parser = datapath.ofproto_parser
            if entry_port not in mac_table.values():
                for mac, port in mac_table.items():
                    # from known device to new device
                    actions = [parser.OFPActionOutput(entry_port)]
                    match = parser.OFPMatch(in_port=port, eth_dst=entry_mac)
                    self.add_flow(datapath, 1, match, actions)

                    # from new device to known device
                    actions = [parser.OFPActionOutput(port)]
                    match = parser.OFPMatch(in_port=entry_port, eth_dst=mac)
                    self.add_flow(datapath, 1, match, actions)

                mac_table.update({entry_mac: entry_port})
        return mac_table


class SimpleSwitchController(ControllerBase):
    def __init__(self, req, link, data, **config):
        super(SimpleSwitchController, self).__init__(req, link, data, **config)
        self.simple_switch_app = data[simple_switch_instance_name]

    @route(‘simpleswitch‘, url, methods=[‘GET‘], requirements={‘dpid‘: dpid_lib.DPID_PATTERN})
    def list_mac_table(self, req, **kwargs):

        simple_switch = self.simple_switch_app
        dpid = kwargs[‘dpid‘]

        if dpid not in simple_switch.mac_to_port:
            return Response(status=404)

        mac_table = simple_switch.mac_to_port.get(dpid, {})
        body = json.dumps(mac_table)
        return Response(content_type=‘application/json‘, text=body)

    @route(‘simpleswitch‘, url, methods=[‘PUT‘], requirements={‘dpid‘: dpid_lib.DPID_PATTERN})
    def put_mac_table(self, req, **kwargs):

        simple_switch = self.simple_switch_app
        dpid = kwargs[‘dpid‘]
        try:
            new_entry = req.json if req.body else {}
        except ValueError:
            raise Response(status=400)

        if dpid not in simple_switch.mac_to_port:
            return Response(status=404)

        try:
            mac_table = simple_switch.set_mac_to_port(dpid, new_entry)
            body = json.dumps(mac_table)
            return Response(content_type=‘application/json‘, text=body)
        except Exception as e:
            return Response(status=500)

# --topo sigle,3: 单个交换机，3个主机
# --mac: 自动设置主机的MAC地址
# --switch ovsk: 使用 ovs
# --controller remote: 使用外部OpenFlow控制器
# -x: 启动xterm
$ sudo mn --topo single,3 --mac --switch ovsk --controller remote -x

# ovs-vsctl set Bridge s1 protocols=OpenFlow13

# ryu-manager --verbose ryu/app/simple_switch_rest_13.py

mininet> h1 ping -c1 h2

$ curl -X GET http://127.0.0.1:8080/simpleswitch/mactable/0000000000000001

$ curl -X PUT -d ‘{"mac" : "00:00:00:00:00:01", "port" : 1}‘ http://127.0.0.1:8080/simpleswitch/mactable/0000000000000001
$ curl -X PUT -d ‘{"mac" : "00:00:00:00:00:02", "port" : 2}‘ http://127.0.0.1:8080/simpleswitch/mactable/0000000000000001