Putting hosts in vlan using Ryu controller

Question

I have used the following commands to put four hosts h1 h2 h3 h4 connected to a single switch s1 in two vlan with vlan tag 10 and 20,

First start mininet.

sudo mn --topo single,4 --controller remote --mac -i 10.0.0.1/24

then using ovs commands

first delete s1 as a shortcut to remove the ports sudo ovs-vsctl del-br s1

then adding switch s1 and adding same ports with tags

sudo ovs-vsctl add-br s1
sudo ovs-vsctl add-port s1 s1-eth1 tag=10
sudo ovs-vsctl add-port s1 s1-eth2 tag=20
sudo ovs-vsctl add-port s1 s1-eth3 tag=10
sudo ovs-vsctl add-port s1 s1-eth4 tag=20

now h1 and h3 will be on the same vlan ; h2 and h4 will be on the same v lan.

Now my question is how to do the same using ryu controller not using ovs commands but using programming.

Answer 1

I have done it not exactly using vlan but a list. Here it is.

In simple_switch_13.py

Add this line as global variable

port_to_vlan = {1: 10, 2: 20, 3: 10, 4: 20}

And in packet in handler add this after the actions = [parser.OFPActionOutput(out_port)]:

    if out_port != ofproto.OFPP_FLOOD:
        if port_to_vlan[in_port] != port_to_vlan[out_port]:
            actions = []

The final code is:

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.lib.packet.ether_types import ETH_TYPE_8021Q
from ryu.ofproto import ofproto_v1_3
from ryu.lib.packet import packet, vlan
from ryu.lib.packet import ethernet
from ryu.lib.packet import ether_types

port_to_vlan = {1: 10, 2: 20, 3: 10, 4: 20}


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)

    @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 = format(datapath.id, "d").zfill(16)
        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)]
        if out_port != ofproto.OFPP_FLOOD:
            if port_to_vlan[in_port] != port_to_vlan[out_port]:
                actions = []



        # 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)

The output is: