Bugfix/agilis 4190 limiting management to only selected interfaces

Makefile

@@ -50,6 +50,9 @@ else
 CFLAGS += -std=gnu99
 endif
 
+#We need this for netinet/in.h IN6_* macros
+CFLAGS += -D_GNU_SOURCE
+
 # If not cross-compiling, then run sudo by default
 ifeq ($(origin CROSSCOMPILE), undefined)
 SUDO_ASKPASS ?= /usr/bin/ssh-askpass

config/config.exs

@@ -0,0 +1,9 @@
+use Mix.Config
+
+#config :nerves_network_interface, :managed_interfaces,
+#  ["eth0", "ens38"]
+
+# Other possible configurations:
+# 1. Manage all available interfaces - explicitly said implicit equivalen of no :managed interfaces provided
+# config :nerves_network_interface, :managed_interfaces,
+#   "all"

lib/nerves_network_interface.ex

@@ -34,6 +34,11 @@ defmodule Nerves.NetworkInterface do
   ensure that the port process is running as a privileged user.
   """
 
+  @type interface_name :: String.t
+  @type registration :: 
+    {:ok, pid} |
+    {:error, {:already_registered, pid}}
+
   @doc """
   Return the list of network interfaces on this machine.
   """
@@ -93,4 +98,31 @@ defmodule Nerves.NetworkInterface do
   Returns `:ok` on success or `{:error, reason}` if an error occurs.
   """
   defdelegate setup(ifname, options), to: Nerves.NetworkInterface.Worker
+
+  @doc """
+  Register for Nerves.NetworkInterface events on a specific interface
+
+  The calling process is the process that will be registered for 
+  all events. The events can be handled by implementing a `handle_info\2`.
+
+  `def handle_info({Nerves.NetworkInterface, :ifchanged, ifstate} = event, state)`
+
+  Use :all to register for events from all interfaces.
+
+  The registration registers for messages dispatched out of `Registry`.
+
+  For information on how `Registry` works please see that module's
+  documentation.
+  """
+  @spec register(:all | interface_name) ::
+    registration |
+    [registration] |
+    []
+  def register(:all) do
+    Enum.each(interfaces(), &register/1)
+  end
+
+  def register(ifname) do
+    Registry.register(Nerves.NetworkInterface, ifname, [])
+  end
 end

lib/network_interface/worker.ex

@@ -71,6 +71,7 @@ defmodule Nerves.NetworkInterface.Worker do
     is_broadcast: boolean,
     is_lower_up: boolean,
     is_multicast: boolean,
+    "is_all-multicast": boolean,
     is_up: boolean,
     is_running: boolean,
     mac_address: mac_address,
@@ -125,8 +126,37 @@ defmodule Nerves.NetworkInterface.Worker do
     { :ok, %Nerves.NetworkInterface.Worker{port: port} }
   end
 
+  #Returns intersection of lists a and b
+  defp intersect(a, b), do: a -- (a -- b)
+
+  # Returns list of interfaces to be managed by Nerves.NetworkInterface and Nerves.Network modules
+  # By default this is list of ALL network interfaces available in the system. It can be reduced
+  # by specifying a list of interfaces we want to be managed by Nerves.Network sub-system in the 
+  # .../config/config.exs file.
+  defp get_managed_interfaces(available_interfaces) do
+    managed_interfaces = Application.get_env(:nerves_network_interface, :managed_interfaces, [])
+    Logger.debug "#{__MODULE__}: managed_interfaces = #{inspect managed_interfaces}"
+
+    case managed_interfaces do
+      "all" -> available_interfaces
+      nil -> available_interfaces
+      [] -> available_interfaces
+      _ -> managed_interfaces
+    end
+  end
+
+  def handle_call(:all_interfaces, _from, state) do
+    available_interfaces = call_port(state, :interfaces, [])
+    {:reply, available_interfaces, state }
+  end
+
   def handle_call(:interfaces, _from, state) do
-    response = call_port(state, :interfaces, [])
+    available_interfaces = call_port(state, :interfaces, [])
+    response =
+      get_managed_interfaces(available_interfaces)
+        |> intersect(available_interfaces)
+    Logger.debug "#{__MODULE__}: response: #{inspect response}"
+    IO.puts "#{__MODULE__}: response: #{inspect response}"
     {:reply, response, state }
   end
   def handle_call({:status, ifname}, _from, state) do

src/erlcmd.c

@@ -250,8 +250,21 @@ int erlcmd_encode_errno_error(char *buf, int *index, int err)
     case EROFS:   reason = "erofs"; break;
     case EMLINK:  reason = "emlink"; break;
     case EPIPE:   reason = "epipe"; break;
+    case ENETDOWN:      reason = "enetdown"; break;
+    case ENETUNREACH:   reason = "enetunreach"; break;
+    case ENETRESET:     reason = "enetreset"; break;
+    case ECONNABORTED:  reason = "econnaborted"; break;
+    case ECONNRESET:    reason = "econnreset"; break;
     case EADDRNOTAVAIL: reason = "eaddrnotavail"; break;
-    default:      reason = "unknown"; break;
+    case ENOBUFS:       reason = "enobufs"; break;
+    case EISCONN:       reason = "eisconn"; break;
+    case ENOTCONN:      reason = "enotconn"; break;
+    case ETOOMANYREFS:  reason = "etoomanyrefs"; break;
+    case ETIMEDOUT:     reason = "etimedout"; break;
+    case ECONNREFUSED:  reason = "econnrefused"; break;
+    case EHOSTDOWN:     reason = "ehostdown"; break;
+    case EHOSTUNREACH:  reason = "ehostunreach"; break;
+    default: reason = "unknown"; break;
     }
     return erlcmd_encode_error_tuple(buf, index, reason);
 }