support arp request

apps/sdlan/include/sdlan.hrl

@@ -60,6 +60,10 @@
 %% 欢迎消息
 -define(PACKET_WELCOME, 16#4F).
 
+%% ARP查询
+-define(PACKET_ARP_REQUEST, 16#50).
+-define(PACKET_ARP_RESPONSE, 16#51).
+
 %% 数据转发
 -define(PACKET_STUN_DATA, 16#FF).
 

apps/sdlan/src/quic/sdlan_quic_channel.erl

@@ -159,7 +159,7 @@ handle_event(internal, {frame, <<?PACKET_REGISTER_SUPER, Body/binary>>}, initial
     true = not (sdlan_util:is_multicast_mac(Mac) orelse sdlan_util:is_broadcast_mac(Mac)),
 
     MacBinStr = sdlan_util:format_mac(Mac),
-    IpAddr = sdlan_ipaddr:int_to_ipv4(Ip),
+    IpAddr = sdlan_util:int_to_ipv4(Ip),
     Params = #{
         <<"network_id">> => NetworkId,
         <<"client_id">> => ClientId,
@@ -251,6 +251,28 @@ handle_event(internal, {frame, <<?PACKET_QUERY_INFO, Body/binary>>}, registered,
             keep_state_and_data
     end;
 
+%% arp查询
+handle_event(internal, {frame, <<?PACKET_ARP_REQUEST, Body/binary>>}, registered, #state{stream = Stream, network_id = NetworkId, network_pid = NetworkPid, mac = SrcMac}) when is_pid(NetworkPid) ->
+    #sdl_arp_request{pkt_id = PktId, target_ip = TargetIp} = sdlan_pb:decode_msg(Body, sdl_arp_request),
+    case sdlan_network:arp_request(NetworkPid, TargetIp) of
+        error ->
+            logger:debug("[sdlan_channel] network: ~p, arp_request target_ip: ~p, mac not found", [NetworkId, TargetIp]),
+            EmptyResponse = sdlan_pb:encode_msg(#sdl_empty{
+                pkt_id = PktId
+            }),
+            quic_send(Stream, <<?PACKET_ARP_RESPONSE, EmptyResponse/binary>>),
+            keep_state_and_data;
+        {ok, Mac} ->
+            logger:debug("[sdlan_channel] network: ~p, arp_request target_ip: ~p, mac: ~p", [NetworkId, sdlan_util:int_to_ipv4(TargetIp), sdlan_util:format_mac(Mac)]),
+            PeerInfo = sdlan_pb:encode_msg(#sdl_arp_response{
+                pkt_id = PktId,
+                target_ip = TargetIp,
+                target_mac = Mac
+            }),
+            quic_send(Stream, <<?PACKET_PEER_INFO, PeerInfo/binary>>),
+            keep_state_and_data
+    end;
+
 handle_event(internal, {frame, <<?PACKET_POLICY_REQUEST, Body/binary>>}, registered, #state{stream = Stream, network_pid = NetworkPid}) when is_pid(NetworkPid) ->
     maybe
         PolicyRequest = catch sdlan_pb:decode_msg(Body, sdl_policy_request),

apps/sdlan/src/sdlan_ipaddr.erl

@@ -1,55 +0,0 @@
-%%%-------------------------------------------------------------------
-%%% @author anlicheng
-%%% @copyright (C) 2024, <COMPANY>
-%%% @doc
-%%%
-%%% @end
-%%% Created : 27. 3月 2024 17:43
-%%%-------------------------------------------------------------------
--module(sdlan_ipaddr).
--author("anlicheng").
-
-%% API
--export([ipv4_to_int/1, int_to_ipv4/1, ips/2, format_ip/1]).
--export([ipv6_bytes_to_binary/1]).
-
-format_ip(Ip) when is_integer(Ip) ->
-    int_to_ipv4(Ip);
-format_ip(Ip) ->
-    Ip.
-
--spec ipv4_to_int(Ip :: integer() | binary() | inet:ip4_address()) -> integer().
-ipv4_to_int(Ip) when is_integer(Ip) ->
-    Ip;
-ipv4_to_int({Ip0, Ip1, Ip2, Ip3}) ->
-    <<Ip:32>> = <<Ip0, Ip1, Ip2, Ip3>>,
-    Ip;
-ipv4_to_int(Ip) when is_binary(Ip) ->
-    Parts0 = binary:split(Ip, <<".">>, [global]),
-    Parts = lists:map(fun binary_to_integer/1, Parts0),
-    <<IpInt:32>> = iolist_to_binary(Parts),
-    IpInt.
-
--spec int_to_ipv4(Ip :: integer()) -> binary().
-int_to_ipv4(Ip) when is_integer(Ip) ->
-    <<Ip0, Ip1, Ip2, Ip3>> = <<Ip:32>>,
-    <<(integer_to_binary(Ip0))/binary, $., (integer_to_binary(Ip1))/binary, $., (integer_to_binary(Ip2))/binary, $., (integer_to_binary(Ip3))/binary>>.
-
--spec ips(NetAddr :: binary(), MaskLen :: integer()) -> [Ip :: integer()].
-ips(NetAddr, MaskLen) when is_binary(NetAddr), is_integer(MaskLen) ->
-    Mask = 16#FFFFFFFF bsr MaskLen,
-    Net0 = ipv4_to_int(NetAddr),
-    %% 防止网络地址给得不对，比如: "192.168.1.101",
-    L = 32 - MaskLen,
-    Net = (Net0 bsr L) bsl L,
-    lists:map(fun(V) -> Net + V end, lists:seq(1, Mask - 1)).
-
--spec ipv6_bytes_to_binary(Bytes :: binary()) -> Bin :: binary().
-ipv6_bytes_to_binary(<<A:16, B:16, C:16, D:16, E:16, F:16, G:16, H:16>>) ->
-    Segments = [integer_to_list(X, 16) || X <- [A, B, C, D, E, F, G, H]],
-    % 填充每个段以确保是4位
-    Padded = [string:pad(S, 4, leading, $0) || S <- Segments],
-    % 合并成IPv6地址格式，这里没有处理最简化形式的缩写
-    iolist_to_binary(lists:flatten(string:join(Padded, ":")));
-ipv6_bytes_to_binary(_) ->
-    <<"">>.

apps/sdlan/src/sdlan_network.erl

@@ -20,7 +20,7 @@
 
 %% API
 -export([start_link/2]).
--export([get_name/1, get_pid/1, lookup_pid/1, peer_info/3, unregister/3, debug_info/1, get_network_id/1, attach/6]).
+-export([get_name/1, get_pid/1, lookup_pid/1, peer_info/3, unregister/3, debug_info/1, get_network_id/1, attach/6, arp_request/2]).
 -export([forward/5, update_hole/7, disable_client/2, get_channel/2]).
 -export([test_event/1]).
 
@@ -109,6 +109,10 @@ unregister(Pid, ClientId, Mac) when is_pid(Pid), is_binary(ClientId), is_binary(
 peer_info(Pid, SrcMac, DstMac) when is_pid(Pid), is_binary(SrcMac), is_binary(DstMac) ->
     gen_server:call(Pid, {peer_info, SrcMac, DstMac}).
 
+-spec arp_request(Pid :: pid(), TargetIp :: integer()) -> error | {ok, Mac :: binary()}.
+arp_request(Pid, TargetIp) when is_pid(Pid), is_integer(TargetIp) ->
+    gen_server:call(Pid, {arp_request, TargetIp}).
+
 -spec forward(pid(), Sock :: any(), SrcMac :: binary(), DstMac :: binary(), Packet :: binary()) -> no_return().
 forward(Pid, Sock, SrcMac, DstMac, Packet) when is_pid(Pid), is_binary(SrcMac), is_binary(DstMac), is_binary(Packet) ->
     gen_server:cast(Pid, {forward, Sock, SrcMac, DstMac, Packet}).
@@ -183,7 +187,7 @@ handle_call({attach, ChannelPid, ClientId, Mac, Ip, Hostname}, _From,
     State = #state{network_id = NetworkId, domain = Domain, endpoints = Endpoints, aes_key = AesKey}) ->
     %% 分配ip地址的时候，以mac地址为唯一基准
     logger:debug("[sdlan_network] alloc_ip, network_id: ~p, client_id: ~p, mac: ~p, ip_addr: ~p",
-        [NetworkId, ClientId, sdlan_util:format_mac(Mac), sdlan_ipaddr:int_to_ipv4(Ip)]),
+        [NetworkId, ClientId, sdlan_util:format_mac(Mac), sdlan_util:int_to_ipv4(Ip)]),
     %% 添加域名->ip的映射关系
     sdlan_hostname_regedit:insert(Hostname, Domain, Ip),
 
@@ -246,7 +250,7 @@ handle_call({peer_info, SrcMac, DstMac}, _From, State = #state{endpoints = Endpo
                 {ok, #endpoint{hole = #hole{peer = {SrcNatIp, SrcNatPort}, nat_type = SrcNatType}, v6_info = SrcV6Info}} ?= maps:find(SrcMac, Endpoints),
                 RegisterEvent = sdlan_pb:encode_msg(#sdl_send_register_event {
                     dst_mac = SrcMac,
-                    nat_ip = sdlan_ipaddr:ipv4_to_int(SrcNatIp),
+                    nat_ip = sdlan_util:ipv4_to_int(SrcNatIp),
                     nat_type = SrcNatType,
                     nat_port = SrcNatPort,
                     v6_info = SrcV6Info
@@ -258,6 +262,15 @@ handle_call({peer_info, SrcMac, DstMac}, _From, State = #state{endpoints = Endpo
             {reply, error, State}
     end;
 
+%% arp查询
+handle_call({arp_request, TargetIp}, _From, State = #state{endpoints = Endpoints}) ->
+    case search_endpoint(fun(_, #endpoint{ip = Ip0}) -> Ip0 =:= TargetIp end, Endpoints) of
+        error ->
+            {reply, error, State};
+        {ok, Mac, _} ->
+            {reply, {ok, Mac}, State}
+    end;
+
 handle_call(debug_info, _From, State = #state{network_id = NetworkId, ipaddr = IpAddr, mask_len = MaskLen, owner_id = OwnerId, endpoints = Endpoints}) ->
     Reply = #{
         <<"network_id">> => NetworkId,
@@ -467,7 +480,7 @@ format_endpoint({Mac, #endpoint{client_id = ClientId, ip = Ip, hole = #hole{peer
     #{
         client_id => ClientId,
         mac => sdlan_util:format_mac(Mac),
-        ip => sdlan_ipaddr:int_to_ipv4(Ip),
+        ip => sdlan_util:int_to_ipv4(Ip),
         hole_map => HoleMap,
         v6_info => V6InfoMap
     }.

apps/sdlan/src/sdlan_util.erl

@@ -13,6 +13,8 @@
 -export([rand_byte/1, md5/1, format_mac/1, assert_call/2]).
 -export([json_data/1, json_error/2]).
 -export([is_broadcast_mac/1, is_multicast_mac/1]).
+-export([ipv4_to_int/1, int_to_ipv4/1, ips/2, format_ip/1]).
+-export([ipv6_bytes_to_binary/1]).
 
 -spec format_mac(Mac :: binary()) -> binary().
 format_mac(Mac) when is_binary(Mac) ->
@@ -71,4 +73,46 @@ is_broadcast_mac(Mac) when is_binary(Mac) ->
 
 -spec is_multicast_mac(Mac :: binary()) -> boolean().
 is_multicast_mac(Mac) when is_binary(Mac) ->
-    binary:part(Mac, 0, 3) =:= <<16#01,16#00,16#5E>>.
+    binary:part(Mac, 0, 3) =:= <<16#01,16#00,16#5E>>.
+
+
+format_ip(Ip) when is_integer(Ip) ->
+    int_to_ipv4(Ip);
+format_ip(Ip) ->
+    Ip.
+
+-spec ipv4_to_int(Ip :: integer() | binary() | inet:ip4_address()) -> integer().
+ipv4_to_int(Ip) when is_integer(Ip) ->
+    Ip;
+ipv4_to_int({Ip0, Ip1, Ip2, Ip3}) ->
+    <<Ip:32>> = <<Ip0, Ip1, Ip2, Ip3>>,
+    Ip;
+ipv4_to_int(Ip) when is_binary(Ip) ->
+    Parts0 = binary:split(Ip, <<".">>, [global]),
+    Parts = lists:map(fun binary_to_integer/1, Parts0),
+    <<IpInt:32>> = iolist_to_binary(Parts),
+    IpInt.
+
+-spec int_to_ipv4(Ip :: integer()) -> binary().
+int_to_ipv4(Ip) when is_integer(Ip) ->
+    <<Ip0, Ip1, Ip2, Ip3>> = <<Ip:32>>,
+    <<(integer_to_binary(Ip0))/binary, $., (integer_to_binary(Ip1))/binary, $., (integer_to_binary(Ip2))/binary, $., (integer_to_binary(Ip3))/binary>>.
+
+-spec ips(NetAddr :: binary(), MaskLen :: integer()) -> [Ip :: integer()].
+ips(NetAddr, MaskLen) when is_binary(NetAddr), is_integer(MaskLen) ->
+    Mask = 16#FFFFFFFF bsr MaskLen,
+    Net0 = ipv4_to_int(NetAddr),
+    %% 防止网络地址给得不对，比如: "192.168.1.101",
+    L = 32 - MaskLen,
+    Net = (Net0 bsr L) bsl L,
+    lists:map(fun(V) -> Net + V end, lists:seq(1, Mask - 1)).
+
+-spec ipv6_bytes_to_binary(Bytes :: binary()) -> Bin :: binary().
+ipv6_bytes_to_binary(<<A:16, B:16, C:16, D:16, E:16, F:16, G:16, H:16>>) ->
+    Segments = [integer_to_list(X, 16) || X <- [A, B, C, D, E, F, G, H]],
+    % 填充每个段以确保是4位
+    Padded = [string:pad(S, 4, leading, $0) || S <- Segments],
+    % 合并成IPv6地址格式，这里没有处理最简化形式的缩写
+    iolist_to_binary(lists:flatten(string:join(Padded, ":")));
+ipv6_bytes_to_binary(_) ->
+    <<"">>.