# -*- coding: utf-8 -*-
$LOAD_PATH.unshift File.expand_path('../../../../../trema/ruby', __FILE__)

require 'net/dhcp'
require 'eventmachine'
require 'trema'
require 'racket'

class IPAddr
  def to_short
    [(@addr >> 24) & 0xff, (@addr >> 16) & 0xff, (@addr >> 8) & 0xff, @addr & 0xff]
  end
end

module Dcmgr
  module NodeModules

    class OpenFlowController < Trema::Controller
      include Dcmgr::Logger

      attr_reader :ports
      attr_reader :ovs_ofctl
      attr_reader :local_hw

      @@route_directly = 3
      @@load_dest_table = 4
      @@send_src_table = 5

      @@virtual_src = 6
      @@virtual_dest = 7

      # Re-number these...
      @@arp_antispoof_table = 10
      @@arp_route_table = 11
      @@metadata_outgoing_table = 12
      @@metadata_incoming_table = 13

      @@mac_route_table = 14

      def initialize service_openflow
        @ports = {}
        @service_openflow = service_openflow
        @ovs_ofctl = OvsOfctl.new service_openflow.node.manifest.config
      end

      def start
        logger.info "starting OpenFlow controller."
      end

      def switch_ready datapath_id
        logger.info "switch_ready from %#x." % datapath_id
        ports.clear

        # There's a short period of time between the switch being
        # activated and features_reply installing flow.
        send_message datapath_id, Trema::FeaturesRequest.new
      end

      def features_reply message
        logger.info  "features_reply from %#x." % message.datapath_id
        logger.debug "datapath_id: %#x" % message.datapath_id
        logger.debug "transaction_id: %#x" % message.transaction_id
        logger.debug "n_buffers: %u" % message.n_buffers
        logger.debug "n_tables: %u" % message.n_tables
        logger.debug "capabilities: %u" % message.capabilities
        logger.debug "actions: %u" % message.actions
        logger.info  "ports: %s" % message.ports.collect { | each | each.number }.sort.join( ", " )

        message.ports.each do | each |
          if each.number == OFPP_LOCAL
            @local_hw = each.hw_addr
            logger.debug "OFPP_LOCAL: hw_addr:#{@local_hw.to_s}"
          end
        end

        message.ports.each do | each |
          port = OpenFlowPort.new(each)
          port.is_active = true
          ports[each.number] = port

          if each.number >= OFPP_MAX
            # Do nothing...
          elsif each.name =~ /^eth/
            @service_openflow.add_eth port
          elsif each.name =~ /^vif-/
            @service_openflow.add_instance port
          elsif each.name =~ /^gre-/
            @service_openflow.add_tunnel port
          else
          end
        end

        # Build the routing flow table and some other flows using
        # ovs-ofctl due to the lack of multiple tables support, which
        # was introduced in of-spec 1.1.

        #
        # Classification
        #
        flows = []

        # DHCP queries from instances and network should always go to
        # local host, while queries from local host should go to the
        # network.
        flows << ["priority=#{5},udp,dl_dst=ff:ff:ff:ff:ff:ff,nw_src=0.0.0.0,nw_dst=255.255.255.255,tp_src=68,tp_dst=67", "local"]

        flows << ["priority=#{3},arp", "resubmit(,#{@@arp_antispoof_table})"]
        flows << ["priority=#{3},icmp", "resubmit(,#{@@load_dest_table})"]
        flows << ["priority=#{3},tcp", "resubmit(,#{@@load_dest_table})"]
        flows << ["priority=#{3},udp", "resubmit(,#{@@load_dest_table})"]

        flows << ["priority=#{2},in_port=local", "resubmit(,#{@@route_directly})"]

        #
        # MAC address routing
        #

        flows << ["priority=#{1},table=#{@@mac_route_table},dl_dst=#{@local_hw.to_s}", "local"]
        flows << ["priority=#{1},table=#{@@route_directly},dl_dst=#{@local_hw.to_s}", "local"]
        flows << ["priority=#{1},table=#{@@load_dest_table},dl_dst=#{@local_hw.to_s}", "load:#{OFPP_LOCAL}->NXM_NX_REG0[],resubmit(,#{@@send_src_table})"]

        # Some flows depend on only local being able to send packets
        # with the local mac and ip address, so drop those.
        flows << ["priority=#{6},table=#{@@send_src_table},in_port=local", "output:NXM_NX_REG0[]"]
        flows << ["priority=#{5},table=#{@@send_src_table},dl_src=#{@local_hw.to_s}", "drop"]
        flows << ["priority=#{5},table=#{@@send_src_table},ip,nw_src=#{Isono::Util.default_gw_ipaddr}", "drop"]

        #
        # ARP routing table
        #

        # ARP anti-spoofing flows.
        flows << ["priority=#{1},table=#{@@arp_antispoof_table},arp,in_port=local", "resubmit(,#{@@arp_route_table})"]

        # Replace drop actions with table default action.
        flows << ["priority=#{0},table=#{@@arp_antispoof_table},arp", "drop"]

        # TODO: How will this handle packets from host or eth0 that
        # spoof the mac of an instance?
        flows << ["priority=#{1},table=#{@@arp_route_table},arp,dl_dst=#{@local_hw.to_s}", "local"]

        #
        # Meta-data connections
        #
        flows << ["priority=#{5},tcp,nw_dst=169.254.169.254,tp_dst=80", "resubmit(,#{@@metadata_outgoing_table})"]
        flows << ["priority=#{5},tcp,nw_src=#{Isono::Util.default_gw_ipaddr},tp_src=#{9002}", "resubmit(,#{@@metadata_incoming_table})"]

        flows << ["priority=#{4},table=#{@@metadata_outgoing_table},in_port=local", "drop"]
        flows << ["priority=#{0},table=#{@@metadata_outgoing_table}", "controller"]

        @ovs_ofctl.add_flows_from_list flows        
        @service_openflow.networks.each { |network| update_network network[1] }
      end

      def delete_port port
        port.lock.synchronize {
          return unless port.is_active
          port.is_active = false

          @ovs_ofctl.del_flows_from_list port.active_flows
          port.active_flows.clear
          port.queued_flows.clear
          ports.delete port.port_info.number
        }
      end

      def port_status message
        logger.info "port_status from %#x." % message.datapath_id
        logger.debug "datapath_id: %#x" % message.datapath_id
        logger.debug "reason: #{message.reason}"
        logger.debug "in_port: #{message.phy_port.number}"
        logger.debug "hw_addr: #{message.phy_port.hw_addr}"
        logger.debug "state: %#x" % message.phy_port.state

        case message.reason
        when OFPPR_ADD
          logger.info "Adding port: port:#{message.phy_port.number} name:#{message.phy_port.name}."
          raise "OpenFlowPort" if ports.has_key? message.phy_port.number

          delete_port ports[message.phy_port.number] if ports.has_key? message.phy_port.number

          port = OpenFlowPort.new(message.phy_port)
          port.is_active = true
          ports[message.phy_port.number] = port

          @service_openflow.add_eth port if message.phy_port.name =~ /^eth/
          @service_openflow.add_instance port if message.phy_port.name =~ /^vif-/
          @service_openflow.add_tunnel port if message.phy_port.name =~ /^gre-/

        when OFPPR_DELETE
          logger.info "Deleting instance port: port:#{message.phy_port.number}."
          raise "UnknownOpenflowPort" if not ports.has_key? message.phy_port.number

          delete_port ports[message.phy_port.number] if ports.has_key? message.phy_port.number

        when OFPPR_MODIFY
          logger.info "Ignoring port modify..."
        end
      end

      def packet_in datapath_id, message
        port = ports[message.in_port]

        if port.nil?
          logger.debug "Dropping processing of packet, unknown port."
          return
        end

        if message.arp?
          logger.debug "Got ARP packet; port:#{message.in_port} source:#{message.arp_sha.to_s}:#{message.arp_spa.to_s} dest:#{message.arp_tha.to_s}:#{message.arp_tpa.to_s}."
          return if port.network.nil?

          if message.arp_oper == Racket::L3::ARP::ARPOP_REQUEST and message.arp_tpa.to_i == port.network.dhcp_ip.to_i
            send_arp(datapath_id, message.in_port, Racket::L3::ARP::ARPOP_REPLY,
                     port.network.dhcp_hw.to_s, port.network.dhcp_ip.to_s,
                     message.macsa.to_s, message.arp_spa.to_s)
          end

          return
        end

        if message.ipv4? and message.tcp?
          logger.debug "Got IPv4/TCP packet; port:#{message.in_port} source:#{message.ipv4_saddr.to_s}:#{message.tcp_src_port} dest:#{message.ipv4_daddr.to_s}:#{message.tcp_dst_port}."

          # Add dynamic NAT flows for meta-data connections.
          if message.ipv4_daddr.to_s == "169.254.169.254" and message.tcp_dst_port == 80
            install_dnat_entry datapath_id, message, @@metadata_outgoing_table, @@metadata_incoming_table, OFPP_LOCAL, @local_hw, Isono::Util.default_gw_ipaddr, 9002
            send_packet_out(datapath_id, :packet_in => message, :actions => Trema::ActionOutput.new( :port => OFPP_TABLE ) )
            return
          end

        end

        if message.ipv4? and message.udp?
          logger.debug "Got IPv4/UDP packet; port:#{message.in_port} source:#{message.ipv4_saddr.to_s}:#{message.udp_src_port} dest:#{message.ipv4_daddr.to_s}:#{message.udp_dst_port}."

          return if port.network.nil?

          if message.udp_src_port == 68 and message.udp_dst_port == 67
            dhcp_in = DHCP::Message.from_udp_payload(message.udp_payload)

            logger.debug "DHCP: message:#{dhcp_in.to_s}."

            if port.network.dhcp_ip.nil?
              logger.debug "DHCP: Port has no dhcp_ip: port:#{port.inspect}"
              return
            end

            # Check incoming type...
            message_type = dhcp_in.options.select { |each| each.type == $DHCP_MESSAGETYPE }
            return if message_type.empty? or message_type[0].payload.empty?

            # Verify dhcp_in values...

            if message_type[0].payload[0] == $DHCP_MSG_DISCOVER
              logger.debug "DHCP send: DHCP_MSG_OFFER."
              dhcp_out = DHCP::Offer.new(:options => [DHCP::MessageTypeOption.new(:payload => [$DHCP_MSG_OFFER])])
            elsif message_type[0].payload[0] == $DHCP_MSG_REQUEST
              logger.debug "DHCP send: DHCP_MSG_ACK."
              dhcp_out = DHCP::ACK.new(:options => [DHCP::MessageTypeOption.new(:payload => [$DHCP_MSG_ACK])])
            else
              logger.debug "DHCP send: no handler."
              return
            end

            dhcp_out.xid = dhcp_in.xid
            dhcp_out.yiaddr = Trema::IP.new(port.ip).to_i
            # Verify instead that discover has the right mac address.
            dhcp_out.chaddr = Trema::Mac.new(port.mac).to_short
            dhcp_out.siaddr = port.network.dhcp_ip.to_i

            subnet_mask = IPAddr.new(IPAddr::IN4MASK, Socket::AF_INET).mask(port.network.prefix)

            dhcp_out.options << DHCP::ServerIdentifierOption.new(:payload => port.network.dhcp_ip.to_short)
            dhcp_out.options << DHCP::IPAddressLeaseTimeOption.new(:payload => [ 0xff, 0xff, 0xff, 0xff ])
            dhcp_out.options << DHCP::BroadcastAddressOption.new(:payload => (port.network.ipv4_network | ~subnet_mask).to_short)
            # Host name 'abcdefgh'.
            # Domain name 'foo.local'
            # Domain name server
            # dhcp_out.options << DHCP::RouterOption.new(:payload => port.network.dhcp_ip.split('.').collect { | each | each.to_i })
            dhcp_out.options << DHCP::SubnetMaskOption.new(:payload => subnet_mask.to_short)

            logger.debug "DHCP send: output:#{dhcp_out.to_s}."
            send_udp(datapath_id, message.in_port, port.network.dhcp_hw.to_s, port.network.dhcp_ip.to_s, 67, port.mac.to_s, port.ip, 68, dhcp_out.pack)
          end
        end
      end

      def vendor message
        logger.debug "vendor message from #{message.datapath_id.to_hex}."
        logger.debug "transaction_id: #{message.transaction_id.to_hex}"
        logger.debug "data: #{message.buffer.unpack('H*')}"
      end

      #
      # Public functions
      #

      def install_dnat_entry datapath_id, message, outgoing_table, incoming_table, dest_port, dest_hw, dest_ip, dest_tp
        logger.info "Installing DNAT entry: #{dest_port} #{dest_hw} #{dest_ip}:#{dest_tp}"

        msg_nw_src = message.ipv4_saddr.to_s
        msg_nw_dst = message.ipv4_daddr.to_s

        # We don't need to match against the IP or port used by the
        # classifier to pass the flow to these tables.

        prefix = "priority=3,idle_timeout=#{300},tcp"

        prefix_outgoing = "#{prefix},table=#{outgoing_table},#{@ovs_ofctl.arg_in_port message.in_port}"
        # classifier_outgoing = "nw_dst=#{msg_nw_dst},tp_dst=#{message.tcp_dst_port}"
        match_outgoing = "dl_src=#{message.macsa.to_s},dl_dst=#{message.macda.to_s},nw_src=#{msg_nw_src},tp_src=#{message.tcp_src_port}"
        action_outgoing = "mod_dl_dst:#{dest_hw},mod_nw_dst:#{dest_ip},mod_tp_dst:#{dest_tp},#{@ovs_ofctl.arg_output dest_port}"

        prefix_incoming = "#{prefix},table=#{incoming_table},#{@ovs_ofctl.arg_in_port dest_port}"
        # classifier_incoming = "nw_src=#{dest_ip},tp_src=#{dest_tp}"
        match_incoming = "dl_src=#{dest_hw.to_s},dl_dst=#{message.macsa.to_s},nw_dst=#{msg_nw_src},tp_dst=#{message.tcp_src_port}"
        action_incoming = "mod_dl_src:#{message.macda.to_s},mod_nw_src:#{msg_nw_dst},mod_tp_src:#{message.tcp_dst_port},#{@ovs_ofctl.arg_output message.in_port}"

        @ovs_ofctl.add_flow "#{prefix_outgoing},#{match_outgoing}", action_outgoing
        @ovs_ofctl.add_flow "#{prefix_incoming},#{match_incoming}", action_incoming
      end

      def install_route port, hw, ip
        # MAC address based routing to instance.
        port.queue_flow "priority=#{1}", "table=#{@@mac_route_table},dl_dst=#{hw}", "output:#{port.port_info.number}"

        port.queue_flow "priority=#{2}", "table=#{0},in_port=#{port.port_info.number},dl_src=#{hw}", "resubmit(,#{@@route_directly})"
        port.queue_flow "priority=#{1}", "table=#{@@route_directly},dl_dst=#{hw}", "output:#{port.port_info.number}"

        # @ovs_ofctl.add_flow "priority=#{1},table=#{@@load_dest_table},dl_dst=#{hw}", "load:#{port.port_info.number}->NXM_NX_REG0[],resubmit(,#{@@send_src_table})"
        port.queue_flow "priority=#{1}", "table=#{@@load_dest_table},dl_dst=#{hw}", "drop"
      end

      def install_virtual_route network, port, hw, ip
        port.queue_flow "priority=#{7}", "table=#{0},in_port=#{port.port_info.number}", "load:#{network.id}->NXM_NX_REG1[],resubmit(,#{@@virtual_src})"
        port.queue_flow "priority=#{2}", "table=#{@@virtual_dest},reg1=#{network.id},dl_dst=#{hw}", "output:#{port.port_info.number}"
      end

      def install_arp_antispoof port, hw, ip
        # Require correct ARP source IP/MAC from instance, and protect the instance IP from ARP spoofing.
        port.queue_flow "priority=#{3}", "table=#{@@arp_antispoof_table},arp,in_port=#{port.port_info.number},arp_sha=#{hw},nw_src=#{ip}", "resubmit(,#{@@arp_route_table})"
        port.queue_flow "priority=#{2}", "table=#{@@arp_antispoof_table},arp,arp_sha=#{hw}", "drop"
        port.queue_flow "priority=#{2}", "table=#{@@arp_antispoof_table},arp,nw_src=#{ip}", "drop"

        # Routing of ARP packets to instance.
        port.queue_flow "priority=#{2}", "table=#{@@arp_route_table},arp,dl_dst=#{hw},nw_dst=#{ip}", "output:#{port.port_info.number}"
      end

      def install_virtual_arp_route network, in_port, hw, ip, out_port, remote_hw, remote_ip
        # Require correct ARP source IP/MAC from instance, and protect the instance IP from ARP spoofing.
        # port.queue_flow "priority=#{4}", "table=#{@@virtual_dest},arp,reg1=#{network.id},arp_sha=#{hw},nw_src=#{ip},dl_dst=#{remote_hw},nw_dst=#{remote_ip}", "output:#{out_port}"
        # port.queue_flow "priority=#{3}", "table=#{@@virtual_dest},arp,arp_sha=#{hw}", "drop"
        # port.queue_flow "priority=#{3}", "table=#{@@virtual_dest},arp,nw_src=#{ip}", "drop"

        # Make generic...
        add_flow in_port, "priority=#{4}", "table=#{@@virtual_dest},arp,reg1=#{network.id},dl_dst=#{remote_hw},nw_dst=#{remote_ip}", "output:#{out_port}"

        # Routing of ARP packets to instance.
        add_flow in_port, "priority=#{2}", "table=#{@@arp_route_table},in_port=#{out_port},arp,dl_dst=#{hw},nw_dst=#{ip}", "output:#{in_port}"
      end

      def install_static_icmp icmp_type, icmp_code, port, local_hw, local_ip, src_ip
        match_type = "dl_type=0x0800,nw_proto=1"
        match_type << ",icmp_type=#{icmp_type}" if icmp_type >= 0
        match_type << ",icmp_code=#{icmp_code}" if icmp_code >= 0

        src_ip_match = ""
        src_ip_match << ",nw_src=#{src_ip}" if not src_ip =~ /\/0$/

        incoming_match = "table=#{@@load_dest_table},#{match_type},dl_dst=#{local_hw},nw_dst=#{local_ip}#{src_ip_match}"
        incoming_actions = "load:#{port.port_info.number}->NXM_NX_REG0[],resubmit(,#{@@send_src_table})"
        port.queue_flow "priority=#{3}", incoming_match, incoming_actions

        outgoing_match = "table=#{@@send_src_table},#{match_type},in_port=#{port.port_info.number},dl_src=#{local_hw},nw_src=#{local_ip}#{src_ip_match},"
        outgoing_actions = "output:NXM_NX_REG0[]"
        port.queue_flow "priority=#{3}", outgoing_match, outgoing_actions
      end

      def install_static_transport nw_proto, port, local_hw, local_ip, local_port, remote_ip
        match_type = "dl_type=0x0800,nw_proto=#{nw_proto}"

        src_match = ""
        src_match << ",nw_src=#{remote_ip}" if not remote_ip =~ /\/0$/
        src_match << ",tp_dst=#{local_port}" if local_port != 0
        dst_match = ""
        dst_match << ",nw_dst=#{remote_ip}" if not remote_ip =~ /\/0$/
        dst_match << ",tp_src=#{local_port}" if local_port != 0

        incoming_match = "table=#{@@load_dest_table},#{match_type},dl_dst=#{local_hw},nw_dst=#{local_ip}#{src_match}"
        incoming_actions = "load:#{port.port_info.number}->NXM_NX_REG0[],resubmit(,#{@@send_src_table})"
        port.queue_flow "priority=#{3}", incoming_match, incoming_actions

        outgoing_match = "table=#{@@send_src_table},#{match_type},in_port=#{port.port_info.number},dl_src=#{local_hw},nw_src=#{local_ip}#{dst_match}"
        outgoing_actions = "output:NXM_NX_REG0[]"
        port.queue_flow "priority=#{3}", outgoing_match, outgoing_actions
      end

      def install_static_d_transport nw_proto, port, local_hw, local_ip, remote_ip, remote_port
        match_type = "dl_type=0x0800,nw_proto=#{nw_proto}"

        src_match = ""
        src_match << ",nw_src=#{remote_ip}" if not remote_ip =~ /\/0$/
        src_match << ",tp_src=#{remote_port}" if remote_port != 0
        dst_match = ""
        dst_match << ",nw_dst=#{remote_ip}" if not remote_ip =~ /\/0$/
        dst_match << ",tp_dst=#{remote_port}" if remote_port != 0

        incoming_match = "table=#{@@load_dest_table},#{match_type},dl_dst=#{local_hw},nw_dst=#{local_ip}#{src_match}"
        incoming_actions = "load:#{port.port_info.number}->NXM_NX_REG0[],resubmit(,#{@@send_src_table})"
        port.queue_flow "priority=#{3}", incoming_match, incoming_actions

        outgoing_match = "table=#{@@send_src_table},#{match_type},in_port=#{port.port_info.number},dl_src=#{local_hw},nw_src=#{local_ip}#{dst_match}"
        outgoing_actions = "output:NXM_NX_REG0[]"
        port.queue_flow "priority=#{3}", outgoing_match, outgoing_actions
      end

      def install_virtual_static_d_transport network, nw_proto, in_port, local_hw, local_ip, out_port, remote_ip, remote_port
        match_type = "dl_type=0x0800,nw_proto=#{nw_proto}"

        src_match = ""
        src_match << ",nw_src=#{remote_ip}" if not remote_ip =~ /\/0$/
        src_match << ",tp_src=#{remote_port}" if remote_port != 0
        dst_match = ""
        dst_match << ",nw_dst=#{remote_ip}" if not remote_ip =~ /\/0$/
        dst_match << ",tp_dst=#{remote_port}" if remote_port != 0

        incoming_match = "table=#{@@load_dest_table},#{match_type},dl_dst=#{local_hw},nw_dst=#{local_ip}#{src_match}"
        incoming_actions = "output:#{in_port}"
        add_flow in_port, "priority=#{3}", incoming_match, incoming_actions

        outgoing_match = "table=#{@@virtual_src},reg1=#{network.id},#{match_type},dl_src=#{local_hw},nw_src=#{local_ip}#{dst_match}"
        outgoing_actions = "output:#{out_port}"
        add_flow in_port, "priority=#{3}", outgoing_match, outgoing_actions
      end

      def install_local_icmp port, hw, ip
        match_type = "dl_type=0x0800,nw_proto=1"

        learn_outgoing_match = "priority=#{2},idle_timeout=#{60},table=#{@@load_dest_table},#{match_type},NXM_OF_IN_PORT[],NXM_OF_ETH_SRC[],NXM_OF_ETH_DST[],NXM_OF_IP_SRC[],NXM_OF_IP_DST[]"
        learn_outgoing_actions = "output:NXM_NX_REG0[]"

        learn_incoming_match = "priority=#{2},idle_timeout=#{60},table=#{@@load_dest_table},#{match_type},NXM_OF_IN_PORT[]=NXM_NX_REG0[0..15],NXM_OF_ETH_SRC[]=NXM_OF_ETH_DST[],NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[],NXM_OF_IP_SRC[]=NXM_OF_IP_DST[],NXM_OF_IP_DST[]=NXM_OF_IP_SRC[]"
        learn_incoming_actions = "output:NXM_OF_IN_PORT[]"

        actions = "learn(#{learn_outgoing_match},#{learn_outgoing_actions}),learn(#{learn_incoming_match},#{learn_incoming_actions}),output:NXM_NX_REG0[]"

        port.queue_flow "priority=#{1}", "table=#{@@send_src_table},#{match_type},in_port=#{port.port_info.number},dl_src=#{hw},nw_src=#{ip}", actions
      end

      def install_local_transport nw_proto, port, hw, ip
        case nw_proto
        when 6
          transport_name = "TCP"
          idle_timeout = 7200
        when 17
          transport_name = "UDP"
          idle_timeout = 600
        end

        match_type = "dl_type=0x0800,nw_proto=#{nw_proto}"

        learn_outgoing_match = "priority=#{2},idle_timeout=#{idle_timeout},table=#{@@load_dest_table},#{match_type},NXM_OF_IN_PORT[],NXM_OF_ETH_SRC[],NXM_OF_ETH_DST[],NXM_OF_IP_SRC[],NXM_OF_IP_DST[],NXM_OF_#{transport_name}_SRC[],NXM_OF_#{transport_name}_DST[]"
        learn_outgoing_actions = "output:NXM_NX_REG0[]"

        learn_incoming_match = "priority=#{2},idle_timeout=#{idle_timeout},table=#{@@load_dest_table},#{match_type},NXM_OF_IN_PORT[]=NXM_NX_REG0[0..15],NXM_OF_ETH_SRC[]=NXM_OF_ETH_DST[],NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[],NXM_OF_IP_SRC[]=NXM_OF_IP_DST[],NXM_OF_IP_DST[]=NXM_OF_IP_SRC[],NXM_OF_#{transport_name}_SRC[]=NXM_OF_#{transport_name}_DST[],NXM_OF_#{transport_name}_DST[]=NXM_OF_#{transport_name}_SRC[]"
        learn_incoming_actions = "output:NXM_OF_IN_PORT[]"

        actions = "learn(#{learn_outgoing_match},#{learn_outgoing_actions}),learn(#{learn_incoming_match},#{learn_incoming_actions}),output:NXM_NX_REG0[]"

        port.queue_flow "priority=#{1}", "table=#{@@send_src_table},#{match_type},in_port=#{port.port_info.number},dl_src=#{hw},nw_src=#{ip}", actions
      end

      def install_virtual_network network
        network.flood_flows       << ["priority=#{1},table=#{@@virtual_dest},reg1=#{network.id},reg2=#{0},dl_dst=ff:ff:ff:ff:ff:ff", "", "output:<>", ""]
        network.flood_local_flows << ["priority=#{0},table=#{@@virtual_dest},reg1=#{network.id},dl_dst=ff:ff:ff:ff:ff:ff", "", "output:<>", ""]

        learn_arp_match = "priority=#{1},idle_timeout=#{3600*10},table=#{@@virtual_dest},reg1=#{network.id},reg2=#{0},NXM_OF_ETH_DST[]=NXM_OF_ETH_SRC[]"
        learn_arp_actions = "output:NXM_NX_REG2[]"

        @ovs_ofctl.add_flow "priority=#{2},table=#{@@virtual_src},reg1=#{network.id},reg2=#{0}", "resubmit\\(,#{@@virtual_dest}\\)"
        @ovs_ofctl.add_flow "priority=#{1},table=#{@@virtual_src},reg1=#{network.id},arp", "learn\\(#{learn_arp_match},#{learn_arp_actions}\\),resubmit\\(,#{@@virtual_dest}\\)"
        @ovs_ofctl.add_flow "priority=#{0},table=#{@@virtual_src},reg1=#{network.id}", "resubmit\\(,#{@@virtual_dest}\\)"

        # Catch ARP for the DHCP server.
        @ovs_ofctl.add_flow "priority=#{3},table=#{@@virtual_dest},reg1=#{network.id},arp,nw_dst=#{network.dhcp_ip.to_s}", "controller"

        # Catch DHCP requests.
        @ovs_ofctl.add_flow "priority=#{3},table=#{@@virtual_dest},reg1=#{network.id},udp,dl_dst=#{network.dhcp_hw},nw_dst=#{network.dhcp_ip.to_s},tp_src=68,tp_dst=67", "controller"
        @ovs_ofctl.add_flow "priority=#{3},table=#{@@virtual_dest},reg1=#{network.id},udp,dl_dst=ff:ff:ff:ff:ff:ff,nw_dst=255.255.255.255,tp_src=68,tp_dst=67", "controller"

        logger.info "installed virtual network: id:#{network.id} dhcp_hw:#{network.dhcp_hw} dhcp_ip:#{network.dhcp_ip.to_s}."
      end

      def install_physical_network network
        network.flood_flows << ["priority=#{1},table=#{@@mac_route_table},dl_dst=FF:FF:FF:FF:FF:FF", "", "output:<>", ""]
        network.flood_flows << ["priority=#{1},table=#{@@route_directly},dl_dst=FF:FF:FF:FF:FF:FF", "", "output:<>", ""]
        network.flood_flows << ["priority=#{1},table=#{@@load_dest_table},dl_dst=FF:FF:FF:FF:FF:FF", "", "load:<>->NXM_NX_REG0[],resubmit(,#{@@send_src_table})", ""]
        network.flood_flows << ["priority=#{1},table=#{@@arp_route_table},arp,dl_dst=FF:FF:FF:FF:FF:FF,arp_tha=00:00:00:00:00:00", "", "output:<>", ""]
      end

      def install_gre_tunnel network_id, port
        port.is_tunnel = true
        port.queue_flow "priority=#{7}", "table=#{0},in_port=#{port.port_info.number}", "load:#{network_id}->NXM_NX_REG1[],load:#{port.port_info.number}->NXM_NX_REG2[],resubmit(,#{@@virtual_src})"
      end

      def install_eth port
        port_number = port.port_info.number

        port.queue_flow "priority=#{6}", "udp,in_port=local,dl_dst=ff:ff:ff:ff:ff:ff,nw_src=0.0.0.0,nw_dst=255.255.255.255,tp_src=68,tp_dst=67", "output:#{port_number}"
        port.queue_flow "priority=#{2}", "in_port=#{port_number}",  "resubmit(,#{@@route_directly})"
        port.queue_flow "priority=#{0}", "table=#{@@mac_route_table}", "output:#{port_number}"
        port.queue_flow "priority=#{0}", "table=#{@@route_directly}", "output:#{port_number}"
        port.queue_flow "priority=#{0}", "table=#{@@load_dest_table}", "load:#{port_number}->NXM_NX_REG0[],resubmit(,#{@@send_src_table})"
        port.queue_flow "priority=#{4}", "table=#{@@send_src_table},in_port=#{port_number}", "output:NXM_NX_REG0[]"
        port.queue_flow "priority=#{1}", "table=#{@@arp_antispoof_table},arp,in_port=#{port_number}", "resubmit(,#{@@arp_route_table})"
        port.queue_flow "priority=#{0}", "table=#{@@arp_route_table},arp", "output:#{port_number}"
        port.queue_flow "priority=#{4}", "table=#{@@metadata_outgoing_table},in_port=#{port_number}", "drop"
      end

      def update_network network
        @ovs_ofctl.add_flows_from_list network.generate_flood_flows
      end

      def send_udp datapath_id, out_port, src_hw, src_ip, src_port, dst_hw, dst_ip, dst_port, payload
        raw_out = Racket::Racket.new
        raw_out.l2 = Racket::L2::Ethernet.new
        raw_out.l2.src_mac = src_hw
        raw_out.l2.dst_mac = dst_hw
        
        raw_out.l3 = Racket::L3::IPv4.new
        raw_out.l3.src_ip = src_ip
        raw_out.l3.dst_ip = dst_ip
        raw_out.l3.protocol = 0x11

        raw_out.l4 = Racket::L4::UDP.new
        raw_out.l4.src_port = src_port
        raw_out.l4.dst_port = dst_port
        raw_out.l4.payload = payload

        raw_out.l4.fix!(raw_out.l3.src_ip, raw_out.l3.dst_ip)

        raw_out.layers.compact.each { |l|
          logger.debug "send udp: layer:#{l.pretty}."
        }

        send_packet_out(datapath_id, :data => raw_out.pack, :actions => Trema::ActionOutput.new( :port => out_port ) )
      end

      def send_arp datapath_id, out_port, op_code, src_hw, src_ip, dst_hw, dst_ip
        raw_out = Racket::Racket.new
        raw_out.l2 = Racket::L2::Ethernet.new
        raw_out.l2.ethertype = Racket::L2::Ethernet::ETHERTYPE_ARP
        raw_out.l2.src_mac = src_hw
        raw_out.l2.dst_mac = dst_hw
        
        raw_out.l3 = Racket::L3::ARP.new
        raw_out.l3.opcode = op_code
        raw_out.l3.sha = src_hw
        raw_out.l3.spa = src_ip
        raw_out.l3.tha = dst_hw
        raw_out.l3.tpa = dst_ip

        raw_out.layers.compact.each { |l|
          logger.debug "ARP packet: layer:#{l.pretty}."
        }

        send_packet_out(datapath_id, :data => raw_out.pack, :actions => Trema::ActionOutput.new( :port => out_port ) )
      end

    end


    class OvsOfctl
      include Dcmgr::Logger
      attr_accessor :ovs_ofctl
      attr_accessor :verbose

      def initialize config
        # TODO: Make ovs_vsctl use a real config option.
        @ovs_ofctl = config.ovs_ofctl_path
        @ovs_vsctl = config.ovs_ofctl_path.dup
        @ovs_vsctl[/ovs-ofctl/] = 'ovs-vsctl'

        @switch = config.bridge_novlan
        @verbose = config.verbose_openflow
      end

      def add_flow flow_match, actions
        command = "#{@ovs_ofctl} add-flow #{@switch} #{flow_match},actions=#{actions}"
        logger.debug "'#{command}' => #{system(command)}."
      end

      def del_flow flow_match
        command = "#{@ovs_ofctl} del-flows #{@switch} #{flow_match}"
        logger.debug "'#{command}' => #{system(command)}."
      end

      def add_flows_from_list(flows)
        recmds = []

        eos = "__EOS_#{Isono::Util.gen_id}___"
        recmds << "#{@ovs_ofctl} add-flow #{@switch} - <<'#{eos}'"
        flows.each { |flow|
          full_flow = "#{flow[0]},actions=#{flow[1]}"
          puts "ovs-ofctl add-flow #{@switch} #{full_flow}" if verbose == true
          recmds << full_flow
        }
        recmds << "#{eos}"

        logger.debug("applying flow(s): #{recmds.size - 2}")
        system(recmds.join("\n"))
      end

      def del_flows_from_list(flows)
        recmds = []

        eos = "__EOS_#{Isono::Util.gen_id}___"
        recmds << "#{@ovs_ofctl} del-flows #{@switch} - <<'#{eos}'"
        flows.each { |flow|
          puts "ovs-ofctl del-flows #{@switch} #{flow}" if verbose == true
          recmds << flow
        }
        recmds << "#{eos}"

        logger.debug("removing flow(s): #{recmds.size - 2}")
        system(recmds.join("\n"))
      end

      def arg_in_port port_number
        case port_number
        when OpenFlowController::OFPP_LOCAL
          return "in_port=local"
        else
          return "in_port=#{port_number}" if port_number < OpenFlowController::OFPP_MAX
        end
      end

      def arg_output port_number
        case port_number
        when OpenFlowController::OFPP_LOCAL
          return "local"
        else
          return "output:#{port_number}" if port_number < OpenFlowController::OFPP_MAX
        end
      end

      def add_gre_tunnel tunnel_name, remote_ip, key
        system("#{@ovs_vsctl} add-port #{@switch} #{tunnel_name} -- set interface #{tunnel_name} type=gre options:remote_ip=#{remote_ip} options:key=#{key}")
      end

    end

    class OpenFlowPort
      attr_reader :port_info
      attr_reader :lock
      attr_accessor :has_instance
      attr_accessor :is_active
      attr_accessor :is_tunnel
      attr_accessor :ip
      attr_accessor :mac
      attr_accessor :network

      def initialize port_info
        @port_info = port_info
        @lock = Mutex.new
        @has_instance = false
        @is_active = false
        @is_tunnel = false
      end

      def active_flows
        @active_flows ||= Array.new
      end

      def queued_flows
        @queued_flows ||= Array.new
      end

      def queue_flow prefix, match, actions
        active_flows << match
        queued_flows << ["#{prefix},#{match}", actions]
      end
    end

    class OpenFlowForwardingEntry
      attr_reader :mac
      attr_reader :port_no

      def initialize mac, port_no
        @mac = mac
        @port_no = port_no
      end

      def update port_no
        @port_no = port_no
      end
    end
      
    class OpenFlowForwardingDatabase
      def initialize
        @db = {}
      end

      def port_no_of mac
        dest = @db[mac]

        if dest
          dest.port_no
        else
          nil
        end
      end

      def learn mac, port_no
        entry = @db[mac]

        if entry
          entry.update port_no
        else
          @db[new_entry.mac] = ForwardingEntry.new(mac, port_no)
        end
      end
    end

    class OpenFlowNetwork
      attr_reader :id
      attr_reader :ports
      attr_reader :local_ports
      attr_accessor :virtual
      attr_accessor :dhcp_hw
      attr_accessor :dhcp_ip
      attr_accessor :ipv4_network
      attr_accessor :prefix

      def initialize id
        @id = id
        @ports = []
        @local_ports = []
        @virtual = false
        @prefix = 0
      end

      def add_port port, is_local
        ports << port
        local_ports << port if is_local
      end

      def remove_port port
        ports.delete port
        local_ports.delete port
      end

      def generate_flood_flows
        flows = []
        flood_flows.each { |flow|
          flows << [flow[0], "#{flow[1]}#{generate_flood_actions(flow[2], ports)}#{flow[3]}"]
        }
        flood_local_flows.each { |flow|
          flows << [flow[0], "#{flow[1]}#{generate_flood_actions(flow[2], local_ports)}#{flow[3]}"]
        }
        flows
      end

      def generate_flood_actions template, use_ports
        actions = ""
        use_ports.each { |port|
          actions << ",#{template.gsub('<>', port.to_s)}"
        }
        actions
      end

      def flood_flows
        @flood_flows ||= Array.new
      end

      def flood_local_flows
        @flood_local_flows ||= Array.new
      end

    end

  end
end