net module

apps/sdlan/src/net/arp_packet.erl

@@ -4,13 +4,14 @@
 -module(arp_packet).
 
 -export([parse/1, marshal/1, is_broadcast_mac/1, arp_request/3, arp_response/3]).
-
--define(ARP_REQUEST,  1).
--define(ARP_RESPONSE, 2).
+-export([opcode/1]).
 
 -define(ETHERNET, 16#0001).
 -define(IPV4,     16#0800).
 
+-define(ARP_REQUEST,  1).
+-define(ARP_RESPONSE, 2).
+
 -define(BROADCAST_MAC, <<255,255,255,255,255,255>>).
 
 -record(arp_packet, {
@@ -65,6 +66,10 @@ parse(Bin) when is_binary(Bin) ->
             {error, invalid_length}
     end.
 
+-spec opcode(Arp_packet :: #arp_packet{}) -> atom().
+opcode(#arp_packet{opcode = Opcode}) ->
+    Opcode.
+
 %%--------------------------------------------------------------------
 %% Marshal
 %%--------------------------------------------------------------------

apps/sdlan/src/net/layer_packet.erl

@@ -2,8 +2,8 @@
 %%% @doc Ethernet II layer packet parser
 %%%-------------------------------------------------------------------
 -module(layer_packet).
-
 -export([parse/1, marshal/1, is_broadcast_mac/1, is_multicast_mac/1]).
+-export([packet_type/1, payload/1]).
 
 -define(ETH_ARP, 16#0806).
 -define(ETH_IPV4, 16#0800).
@@ -40,6 +40,14 @@ parse(Bin) when is_binary(Bin) ->
             {error, invalid_length}
     end.
 
+-spec packet_type(Layer_packet :: #layer_packet{}) -> atom().
+packet_type(#layer_packet{type = T}) ->
+    T.
+
+-spec payload(Layer_packet :: #layer_packet{}) -> binary().
+payload(#layer_packet{payload = Payload}) ->
+    Payload.
+
 %%--------------------------------------------------------------------
 
 -spec marshal(#layer_packet{}) -> binary().

apps/sdlan/src/sdlan_network.erl

@@ -339,6 +339,31 @@ handle_cast({forward, Sock, SrcMac, DstMac, Packet}, State = #state{network_id =
     %% 广播地址和组播地址，需要转发到整个网络
     case sdlan_util:is_broadcast_mac(DstMac) orelse sdlan_util:is_multicast_mac(DstMac) of
         true ->
+            %% 解析Packet是不是arp请求
+            case layer_packet:parse(Packet) of
+                {ok, LayerPacket} ->
+                    case layer_packet:packet_type(LayerPacket) of
+                        arp ->
+                            case arp_packet:parse(layer_packet:payload(LayerPacket)) of
+                                {ok, ArpPacket} ->
+
+                                    case arp_packet:opcode(ArpPacket) of
+                                        request ->
+                                            %% TODO
+                                            Mac = <<>>,
+                                            Ip = 12,
+                                            ArpResponse = arp_packet:marshal(arp_packet:arp_response(ArpPacket, Mac, Ip)),
+
+                                            #endpoint{hole = #hole{peer = {NatIp, NatPort}}} = maps:get(SrcMac, UsedMap),
+                                            gen_udp:send(Sock, NatIp, NatPort, ArpResponse)
+                                    end;
+
+                                _ ->
+                                    ok
+                            end
+                    end
+            end,
+
             PacketBytes = byte_size(Packet),
             %% 消息广播
             maps:foreach(fun(Mac, #endpoint{hole = Hole}) ->