add udp pool

apps/dns_proxy/src/dns_handler.erl

@@ -13,22 +13,27 @@
 -include_lib("dns_erlang/include/dns_records.hrl").
 -include_lib("dns_erlang/include/dns_terms.hrl").
 
--export([handle_request/4]).
+-export([start_link/4, init/4]).
 
-handle_request(Sock, Ip, Port, Packet) ->
+start_link(Sock, Ip, Port, Packet) ->
+    {ok, proc_lib:spawn(?MODULE, init, [Sock, Ip, Port, Packet])}.
+
+init(Sock, Ip, Port, Packet) ->
     case dns:decode_message(Packet) of
-        {ok, Msg} ->
-            %Qname = (Msg#dns_message.questions)#dns_question.qname,
-            Qname = <<"www.baidu.com">>,
+        Msg = #dns_message{qc = 1, questions = [Question|_]} ->
+            Qname = Question#dns_query.name,
+            lager:debug("[dns_handler] qname: ~p", [Qname]),
             case dns_cache:lookup(Qname) of
                 {hit, R} ->
                     Resp = build_response(Msg, R),
                     gen_udp:send(Sock, Ip, Port, dns:encode_message(Resp));
                 miss ->
+                    lager:debug("[dns_handler] cache is miss"),
                     forward_to_upstream(Sock, Ip, Port, Packet)
             end;
-        _ ->
-            ok
+        Other ->
+            lager:warning("decode msg get error: ~p", [Other]),
+            exit(normal)
     end.
 
 forward_to_upstream(Sock, Ip, Port, Packet) ->

apps/dns_proxy/src/dns_handler_sup.erl

@@ -47,7 +47,7 @@ init([]) ->
     SupFlags = #{strategy => simple_one_for_one, intensity => 0, period => 1},
     Spec = #{
         id => dns_handler,
-        start => {'dns_handler', dns_handler, []},
+        start => {'dns_handler', start_link, []},
         restart => temporary,
         shutdown => 2000,
         type => worker,

apps/dns_proxy/src/dns_proxy.app.src

@@ -8,6 +8,7 @@
     sync,
     lager,
     dns_erlang,
+    poolboy,
     kernel,
     stdlib
    ]},

apps/dns_proxy/src/dns_proxy_sup.erl

@@ -27,6 +27,10 @@ start_link() ->
 %%                  modules => modules()}   % optional
 init([]) ->
     SupFlags = #{strategy => one_for_one, intensity => 1000, period => 3600},
+
+    {ok, PoolArgs} = application:get_env(dns_proxy, dns_resolver_pool),
+    ResolverPoolSpec = poolboy:child_spec(dns_resolver_pool, [{name, {local, dns_resolver_pool}}|PoolArgs], []),
+
     ChildSpecs = [
         #{
             id => dns_handler_sup,
@@ -45,6 +49,6 @@ init([]) ->
             modules => ['dns_server']
         }
     ],
-    {ok, {SupFlags, ChildSpecs}}.
+    {ok, {SupFlags, [ResolverPoolSpec|ChildSpecs]}}.
 
 %% internal functions

apps/dns_proxy/src/dns_resolver.erl

@@ -0,0 +1,130 @@
+%%%-------------------------------------------------------------------
+%%% @author anlicheng
+%%% @copyright (C) 2025, <COMPANY>
+%%% @doc
+%%%
+%%% @end
+%%% Created : 03. 12月 2025 18:26
+%%%-------------------------------------------------------------------
+-module(dns_resolver).
+-author("anlicheng").
+-include_lib("dns_erlang/include/dns.hrl").
+
+-behaviour(gen_server).
+
+%% API
+-export([start_link/0]).
+
+%% gen_server callbacks
+-export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
+
+-export([forward/6]).
+
+-define(SERVER, ?MODULE).
+
+-record(state, {
+    socket,
+    tid
+}).
+
+%%%===================================================================
+%%% API
+%%%===================================================================
+
+forward(Pid, ReceiverPid, Ref, TargetIp, TargetPort, Request) ->
+    gen_server:cast(Pid, {forward, ReceiverPid, Ref, TargetIp, TargetPort, Request}).
+
+%% @doc Spawns the server and registers the local name (unique)
+-spec(start_link() ->
+    {ok, Pid :: pid()} | ignore | {error, Reason :: term()}).
+start_link() ->
+    gen_server:start_link({local, ?SERVER}, ?MODULE, [], []).
+
+%%%===================================================================
+%%% gen_server callbacks
+%%%===================================================================
+
+%% @private
+%% @doc Initializes the server
+-spec(init(Args :: term()) ->
+    {ok, State :: #state{}} | {ok, State :: #state{}, timeout() | hibernate} |
+    {stop, Reason :: term()} | ignore).
+init([]) ->
+    {ok, Sock} = gen_udp:open(0, [binary, {active, true}]),
+    %% 通过ets来保存映射关系
+    Table = list_to_atom("udp_ets:" ++ erlang:unique_integer([monotonic, positive])),
+    Tid = ets:new(Table, [set, {read_concurrency, true}, {write_concurrency, true}, private]),
+
+    {ok, #state{socket = Sock, tid = Tid}}.
+
+%% @private
+%% @doc Handling call messages
+-spec(handle_call(Request :: term(), From :: {pid(), Tag :: term()},
+    State :: #state{}) ->
+    {reply, Reply :: term(), NewState :: #state{}} |
+    {reply, Reply :: term(), NewState :: #state{}, timeout() | hibernate} |
+    {noreply, NewState :: #state{}} |
+    {noreply, NewState :: #state{}, timeout() | hibernate} |
+    {stop, Reason :: term(), Reply :: term(), NewState :: #state{}} |
+    {stop, Reason :: term(), NewState :: #state{}}).
+handle_call(_Request, _From, State = #state{}) ->
+    {reply, ok, State}.
+
+%% @private
+%% @doc Handling cast messages
+-spec(handle_cast(Request :: term(), State :: #state{}) ->
+    {noreply, NewState :: #state{}} |
+    {noreply, NewState :: #state{}, timeout() | hibernate} |
+    {stop, Reason :: term(), NewState :: #state{}}).
+handle_cast({forward, ReceiverPid, Ref, TargetIp, TargetPort, Request}, State = #state{socket = Socket, tid = Tid}) ->
+    case dns:decode_message(Request) of
+        #dns_message{id = TxId, questions = [#dns_query{name = QName}|_]} ->
+            ok = gen_udp:send(Socket, TargetIp, TargetPort, Request),
+            ok = ets:insert(Tid, {{TxId, TargetIp, TargetPort, QName}, {Ref, ReceiverPid}});
+        _ ->
+            ok
+    end,
+    {noreply, State}.
+
+%% @private
+%% @doc Handling all non call/cast messages
+-spec(handle_info(Info :: timeout() | term(), State :: #state{}) ->
+    {noreply, NewState :: #state{}} |
+    {noreply, NewState :: #state{}, timeout() | hibernate} |
+    {stop, Reason :: term(), NewState :: #state{}}).
+handle_info({udp, Socket, TargetIp, TargetPort, Resp}, State = #state{tid = Tid, socket = Socket}) ->
+    case dns:decode_message(Resp) of
+        #dns_message{id = TxId, questions = [#dns_query{name = QName}|_]} ->
+            Key = {TxId, TargetIp, TargetPort, QName},
+            case ets:take(Tid, Key) of
+                [{_, {Ref, ReceiverPid}}] ->
+                    ReceiverPid ! {xyz, Ref, Resp};
+                [] ->
+                    ok
+            end;
+        _ ->
+            ok
+    end,
+    {noreply, State}.
+
+%% @private
+%% @doc This function is called by a gen_server when it is about to
+%% terminate. It should be the opposite of Module:init/1 and do any
+%% necessary cleaning up. When it returns, the gen_server terminates
+%% with Reason. The return value is ignored.
+-spec(terminate(Reason :: (normal | shutdown | {shutdown, term()} | term()),
+    State :: #state{}) -> term()).
+terminate(_Reason, _State = #state{}) ->
+    ok.
+
+%% @private
+%% @doc Convert process state when code is changed
+-spec(code_change(OldVsn :: term() | {down, term()}, State :: #state{},
+    Extra :: term()) ->
+    {ok, NewState :: #state{}} | {error, Reason :: term()}).
+code_change(_OldVsn, State = #state{}, _Extra) ->
+    {ok, State}.
+
+%%%===================================================================
+%%% Internal functions
+%%%===================================================================

apps/dns_proxy/src/dns_server.erl

@@ -24,6 +24,7 @@ init() ->
 loop(Sock) ->
     receive
         {udp, Sock, Ip, Port, Packet} ->
-            dns_handler_sup:start_handler(Sock, Ip, Port, Packet),
+            Res = dns_handler_sup:start_handler(Sock, Ip, Port, Packet),
+            lager:debug("ip: ~p, get a packet: ~p, handler res: ~p", [{Ip, Port}, Packet, Res]),
             loop(Sock)
     end.

config/sys.config

@@ -4,7 +4,13 @@
     %% 公共的dns域名解析服务
     {public_dns_servers, [
       {{8,8,8,8}, 53},
-      {{1,1,1,1}, 53}
+      {{8,8,8,8}, 53}
+    ]},
+
+    {dns_resolver_pool, [
+      {size, 200},
+      {max_overflow, 1000},
+      {worker_module, dns_resolver}
     ]}
 
   ]},

rebar.config

@@ -1,6 +1,7 @@
 {erl_opts, [debug_info]}.
 {deps, [
     {dns_erlang, ".*", {git, "https://github.com/dnsimple/dns_erlang.git", {tag, "v4.4.0"}}},
+    {poolboy, ".*", {git, "https://github.com/devinus/poolboy.git", {tag, "1.5.1"}}},
     {sync, ".*", {git, "https://github.com/rustyio/sync.git", {branch, "master"}}},
     {parse_trans, ".*", {git, "https://github.com/uwiger/parse_trans", {tag, "3.0.0"}}},
     {lager, ".*", {git,"https://github.com/erlang-lager/lager.git", {tag, "3.9.2"}}}