fix

apps/dns_proxy/src/dns_handler.erl

@@ -4,23 +4,82 @@
 %%% @doc
 %%%
 %%% @end
-%%% Created : 03. 12月 2025 17:27
+%%% Created : 03. 12月 2025 23:00
 %%%-------------------------------------------------------------------
 -module(dns_handler).
 -author("anlicheng").
 
+-behaviour(gen_server).
+
 -include_lib("dns_erlang/include/dns.hrl").
 -include_lib("dns_erlang/include/dns_records.hrl").
 -include_lib("dns_erlang/include/dns_terms.hrl").
 
--define(RESOLVER_POOL, dns_resolver_pool).
+%% API
+-export([start_link/4]).
 
--export([start_link/4, init/4]).
+%% gen_server callbacks
+-export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
+-export([handle/1]).
+
+-define(SERVER, ?MODULE).
+-define(RESOLVER_POOL, dns_resolver_pool).
+%% 转发的超时设置
+-define(UPSTREAM_TIMEOUT, 1000).
+
+-record(state, {
+    socket,
+    src_ip,
+    src_port,
+    packet,
+    dns_servers = []
+}).
+
+%%%===================================================================
+%%% API
+%%%===================================================================
 
 start_link(Sock, Ip, Port, Packet) ->
-    {ok, proc_lib:spawn(?MODULE, init, [Sock, Ip, Port, Packet])}.
+    gen_server:start_link(?MODULE, [Sock, Ip, Port, Packet], []).
 
-init(Sock, Ip, Port, Packet) ->
+handle(Pid) when is_pid(Pid) ->
+    gen_server:cast(Pid, handle).
+
+%%%===================================================================
+%%% 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([Sock, SrcIp, SrcPort, Packet]) ->
+    {ok, DNSServers} = application:get_env(dns_proxy, public_dns_servers),
+    %% 进程的最大存活时间
+    erlang:start_timer(5000, self(), handler_max_ttl),
+    {ok, #state{dns_servers = DNSServers, socket = Sock, src_ip = SrcIp, src_port = SrcPort, packet = Packet}}.
+
+%% @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(handle, State = #state{socket = Sock, src_ip = SrcIp, src_port = SrcPort, packet = Packet, dns_servers = [{DnsIp, DnsPort}|RestDnsServers]}) ->
     case dns:decode_message(Packet) of
         Msg = #dns_message{qc = 1, questions = [Question|_]} ->
             Qname = Question#dns_query.name,
@@ -28,31 +87,70 @@ init(Sock, Ip, Port, Packet) ->
             case dns_cache:lookup(Qname) of
                 {hit, R} ->
                     Resp = build_response(Msg, R),
-                    gen_udp:send(Sock, Ip, Port, dns:encode_message(Resp));
+                    gen_udp:send(Sock, SrcIp, SrcPort, dns:encode_message(Resp)),
+                    {stop, normal};
                 miss ->
                     lager:debug("[dns_handler] cache is miss"),
-                    forward_to_upstream(Sock, Ip, Port, Packet)
+                    forward_to_upstream(DnsIp, DnsPort, Packet, Msg),
+                    %% 开启定时器，超时后递归请求后面的服务
+                    erlang:start_timer(?UPSTREAM_TIMEOUT, self(), trigger_next),
+                    {noreply, State#state{dns_servers = RestDnsServers}}
             end;
         Other ->
-            lager:warning("decode msg get error: ~p", [Other]),
+            lager:warning("[] decode msg get error: ~p", [Other]),
-            exit(normal)
+            {stop, normal}
     end.
 
-forward_to_upstream(Sock, SrcIp, SrcPort, Request) ->
+%% @private
-    {ok, DNSServers} = application:get_env(dns_proxy, public_dns_servers),
+%% @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{}}).
+%% 处理超时重试
+handle_info({timeout, _, trigger_next}, State = #state{packet = Packet, dns_servers = [{DnsIp, DnsPort}|RestDnsServers]}) ->
+    forward_to_upstream(DnsIp, DnsPort, Packet),
+    erlang:start_timer(?UPSTREAM_TIMEOUT, self(), trigger_next),
+    {noreply, State#state{dns_servers = RestDnsServers}};
+handle_info({timeout, _, trigger_next}, State = #state{dns_servers = []}) ->
+    {stop, normal, State};
 
+handle_info({timeout, _, handler_max_ttl}, State) ->
+    lager:debug("[dns_handler] reach the max ttl"),
+    {stop, normal, State};
+
+%% 收到请求
+handle_info({dns_resolver_reply, Resp}, State = #state{socket = Sock, src_ip = SrcIp, src_port = SrcPort}) ->
+    gen_udp:send(Sock, SrcIp, SrcPort, dns:encode_message(Resp)),
+    {stop, normal, 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
+%%%===================================================================
+
+forward_to_upstream(TargetIp, TargetPort, Request, Msg) ->
     ReceiverPid = self(),
-    Ref = make_ref(),
     poolboy:transaction(?RESOLVER_POOL, fun(Pid) ->
-        dns_resolver:forward(Pid, ReceiverPid, Ref, TargetIp, TargetPort, Request)
+        dns_resolver:forward(Pid, ReceiverPid, TargetIp, TargetPort, Request, Msg)
-                                        end),
+                                        end).
-
-    receive
-        {udp, SendSock, _UIp, _UPort, Resp} ->
-            gen_udp:send(Sock, Ip, Port, Resp)
-    after 2000 ->
-        ok
-    end.
 
 build_response(Req, RR) ->
     Msg = Req,

apps/dns_proxy/src/dns_handler2.erl

@@ -1,151 +0,0 @@
-%%%-------------------------------------------------------------------
-%%% @author anlicheng
-%%% @copyright (C) 2025, <COMPANY>
-%%% @doc
-%%%
-%%% @end
-%%% Created : 03. 12月 2025 23:00
-%%%-------------------------------------------------------------------
--module(dns_handler2).
--author("anlicheng").
-
--behaviour(gen_server).
-
--include_lib("dns_erlang/include/dns.hrl").
--include_lib("dns_erlang/include/dns_records.hrl").
--include_lib("dns_erlang/include/dns_terms.hrl").
-
-%% API
--export([start_link/4]).
-
-%% gen_server callbacks
--export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
--export([handle/1]).
-
--define(SERVER, ?MODULE).
--define(RESOLVER_POOL, dns_resolver_pool).
-%% 转发的超时设置
--define(UPSTREAM_TIMEOUT, 1000).
-
--record(state, {
-    socket,
-    src_ip,
-    src_port,
-    packet,
-    dns_servers = []
-}).
-
-%%%===================================================================
-%%% API
-%%%===================================================================
-
-start_link(Sock, Ip, Port, Packet) ->
-    gen_server:start_link(?MODULE, [Sock, Ip, Port, Packet], []).
-
-handle(Pid) when is_pid(Pid) ->
-    gen_server:cast(Pid, handle).
-
-%%%===================================================================
-%%% 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([Sock, SrcIp, SrcPort, Packet]) ->
-    {ok, DNSServers} = application:get_env(dns_proxy, public_dns_servers),
-    {ok, #state{dns_servers = DNSServers, socket = Sock, src_ip = SrcIp, src_port = SrcPort, packet = Packet}}.
-
-%% @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(handle, State = #state{socket = Sock, src_ip = SrcIp, src_port = SrcPort, packet = Packet, dns_servers = [{DnsIp, DnsPort}|RestDnsServers]}) ->
-    case dns:decode_message(Packet) of
-        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, SrcIp, SrcPort, dns:encode_message(Resp)),
-                    {stop, normal};
-                miss ->
-                    lager:debug("[dns_handler] cache is miss"),
-                    forward_to_upstream(DnsIp, DnsPort, Packet),
-                    %% 开启定时器，超时后递归请求后面的服务
-                    erlang:start_timer(?UPSTREAM_TIMEOUT, self(), trigger_next),
-                    {noreply, State#state{dns_servers = RestDnsServers}}
-            end;
-        Other ->
-            lager:warning("[] decode msg get error: ~p", [Other]),
-            {stop, normal}
-    end.
-
-%% @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{}}).
-%% 处理超时重试
-handle_info({timeout, _, trigger_next}, State = #state{packet = Packet, dns_servers = [{DnsIp, DnsPort}|RestDnsServers]}) ->
-    forward_to_upstream(DnsIp, DnsPort, Packet),
-    erlang:start_timer(?UPSTREAM_TIMEOUT, self(), trigger_next),
-    {noreply, State#state{dns_servers = RestDnsServers}};
-handle_info({timeout, _, trigger_next}, State = #state{dns_servers = []}) ->
-    {stop, normal, State};
-
-%% 收到请求
-handle_info({dns_resolver_reply, Resp}, State = #state{socket = Sock, src_ip = SrcIp, src_port = SrcPort}) ->
-    gen_udp:send(Sock, SrcIp, SrcPort, dns:encode_message(Resp)),
-    {stop, normal, 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
-%%%===================================================================
-
-forward_to_upstream(TargetIp, TargetPort, Request) ->
-    ReceiverPid = self(),
-    poolboy:transaction(?RESOLVER_POOL, fun(Pid) ->
-        dns_resolver:forward(Pid, ReceiverPid, TargetIp, TargetPort, Request)
-                                        end).
-
-build_response(Req, RR) ->
-    Msg = Req,
-    Msg#dns_message{answers=[RR], qr=true, aa=true}.

apps/dns_proxy/src/dns_resolver.erl

@@ -18,9 +18,10 @@
 %% gen_server callbacks
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
 
--export([forward/5]).
+-export([forward/6]).
 
 -define(SERVER, ?MODULE).
+-define(REQUEST_TTL, 5000).
 
 -record(state, {
     socket,
@@ -31,8 +32,8 @@
 %%% API
 %%%===================================================================
 
-forward(Pid, ReceiverPid, TargetIp, TargetPort, Request) ->
+forward(Pid, ReceiverPid, TargetIp, TargetPort, Request, Msg) ->
-    gen_server:cast(Pid, {forward, ReceiverPid, TargetIp, TargetPort, Request}).
+    gen_server:cast(Pid, {forward, ReceiverPid, TargetIp, TargetPort, Request, Msg}).
 
 %% @doc Spawns the server and registers the local name (unique)
 -spec(start_link(Args :: list()) ->
@@ -75,14 +76,14 @@ handle_call(_Request, _From, State = #state{}) ->
     {noreply, NewState :: #state{}} |
     {noreply, NewState :: #state{}, timeout() | hibernate} |
     {stop, Reason :: term(), NewState :: #state{}}).
-handle_cast({forward, ReceiverPid, TargetIp, TargetPort, Request}, State = #state{socket = Socket, tid = Tid}) ->
+handle_cast({forward, ReceiverPid, TargetIp, TargetPort, Request, #dns_message{id = TxId, questions = [#dns_query{name = QName}|_]}}, 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}, ReceiverPid});
+
-        _ ->
+    Key = {TxId, TargetIp, TargetPort, QName},
-            ok
+    ok = ets:insert(Tid, {Key, ReceiverPid}),
-    end,
+
+    erlang:start_timer(?REQUEST_TTL, self(), {clean_ticker, Key}),
+
     {noreply, State}.
 
 %% @private
@@ -109,6 +110,11 @@ handle_info({udp, Socket, TargetIp, TargetPort, Resp}, State = #state{tid = Tid,
         _ ->
             ok
     end,
+    {noreply, State};
+
+handle_info({timeout, _, {clean_ticker, Key}}, State = #state{tid = Tid}) ->
+    true = ets:delete(Tid, Key),
+
     {noreply, State}.
 
 %% @private

apps/dns_proxy/src/dns_server.erl

@@ -16,7 +16,12 @@ init() ->
 loop(Sock) ->
     receive
         {udp, Sock, Ip, Port, Packet} ->
-            Res = dns_handler_sup:start_handler(Sock, Ip, Port, Packet),
+            lager:debug("[dns_server] ip: ~p, get a packet: ~p", [{Ip, Port}, Packet]),
-            lager:debug("[dns_server] ip: ~p, get a packet: ~p, handler res: ~p", [{Ip, Port}, Packet, Res]),
+            case dns_handler_sup:start_handler(Sock, Ip, Port, Packet) of
+                {ok, HandlerPid} ->
+                    dns_handler:handle(HandlerPid);
+                Error ->
+                    lager:debug("[dns_server] start handler get error: ~p", [Error])
+            end,
             loop(Sock)
     end.