Add patch_panel example

examples/patch_panel/lib/patch_panel/openflow/controller.ex

@@ -0,0 +1,81 @@
+defmodule PatchPanel.Openflow.Controller do
+  use GenServer
+  use Tres.Controller
+
+  import Logger
+
+  defmodule State do
+    defstruct [:datapath_id]
+  end
+
+  def create_patch(datapath_id, port_a, port_b) do
+    case PatchPanel.Openflow.Registry.lookup_pid(datapath_id) do
+      nil ->
+        {:error, :not_found}
+      pid when is_pid(pid) ->
+        GenServer.call(pid, {:create, port_a, port_b})
+    end
+  end
+
+  def delete_patch(datapath_id, port_a, port_b) do
+    case PatchPanel.Openflow.Registry.lookup_pid(datapath_id) do
+      nil ->
+        {:error, :not_found}
+      pid when is_pid(pid) ->
+        GenServer.call(pid, {:delete, port_a, port_b})
+    end
+  end
+
+  def start_link({datapath_id, _aux_id}, _start_args) do
+    GenServer.start_link(__MODULE__, [datapath_id])
+  end
+
+  def init([datapath_id]) do
+    :ok = info("Switch Connected: datapath_id = #{datapath_id}")
+    {:ok, _} = PatchPanel.Openflow.Registry.register(datapath_id)
+    {:ok, %State{datapath_id: datapath_id}}
+  end
+
+  def handle_call({:create, port_a, port_b}, _from, %State{datapath_id: datapath_id} = state) do
+    :ok = add_flow_entries(datapath_id, port_a, port_b)
+    {:reply, :ok, state}
+  end
+  def handle_call({:delete, port_a, port_b}, _from, %State{datapath_id: datapath_id} = state) do
+    :ok = del_flow_entries(datapath_id, port_a, port_b)
+    {:reply, :ok, state}
+  end
+
+  def handle_info({:switch_disconnected, reason}, %State{datapath_id: datapath_id} = state) do
+    :ok = warn("#{datapath_id} disconnected: reason = #{inspect(reason)}")
+    :ok = PatchPanel.Openflow.Registry.unregister(datapath_id)
+    {:stop, :normal, state}
+  end
+  def handle_info(_info, state) do
+    {:noreply, state}
+  end
+
+  def terminate(reason, state) do
+    {reason, state}
+  end
+
+  # private functions
+
+  defp add_flow_entries(datapath_id, port_a, port_b) do
+    :ok = send_flow_mod_add(
+      datapath_id,
+      match: Match.new(in_port: port_a),
+      instructions: [ApplyActions.new(Output.new(port_b))]
+    )
+
+    :ok = send_flow_mod_add(
+      datapath_id,
+      match: Match.new(in_port: port_b),
+      instructions: [ApplyActions.new(Output.new(port_a))]
+    )
+  end
+
+  defp del_flow_entries(datapath_id, port_a, port_b) do
+    :ok = send_flow_mod_delete(datapath_id, match: Match.new(in_port: port_a))
+    :ok = send_flow_mod_delete(datapath_id, match: Match.new(in_port: port_b))
+  end
+end

examples/patch_panel/lib/patch_panel/openflow/registry.ex

@@ -0,0 +1,16 @@
+defmodule PatchPanel.Openflow.Registry do
+  def register(datapath_id) do
+    {:ok, _} = Registry.register(__MODULE__, datapath_id, [])
+  end
+
+  def unregister(datapath_id) do
+    :ok = Registry.unregister(__MODULE__, datapath_id)
+  end
+
+  def lookup_pid(datapath_id) do
+    case Registry.lookup(__MODULE__, datapath_id) do
+      [{pid, _}] -> pid
+      [] -> nil
+    end
+  end
+end