130 lines
4.5 KiB
Erlang
130 lines
4.5 KiB
Erlang
%%%-------------------------------------------------------------------
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%%% @author anlicheng
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%%% @copyright (C) 2024, <COMPANY>
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%%% @doc
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%%%
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%%% @end
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%%% Created : 09. 4月 2024 17:37
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%%%-------------------------------------------------------------------
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-module(dns_server).
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-author("anlicheng").
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-include("sdlan.hrl").
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-include("sdlan_pb.hrl").
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-behaviour(gen_server).
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%% API
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-export([start_link/2]).
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-export([get_name/1]).
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%% gen_server callbacks
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-export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
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-define(SERVER, ?MODULE).
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-record(state, {
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socket
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}).
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%%%===================================================================
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%%% API
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%%%===================================================================
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-spec get_name(Id :: integer()) -> atom().
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get_name(Id) when is_integer(Id) ->
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list_to_atom("dns_server:" ++ integer_to_list(Id)).
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%% @doc Spawns the server and registers the local name (unique)
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-spec(start_link(Name :: atom(), Port :: integer()) ->
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{ok, Pid :: pid()} | ignore | {error, Reason :: term()}).
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start_link(Name, Port) when is_atom(Name), is_integer(Port) ->
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gen_server:start_link({local, Name}, ?MODULE, [Port], []).
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%%%===================================================================
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%%% gen_server callbacks
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%%%===================================================================
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%% @private
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%% @doc Initializes the server
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-spec(init(Args :: term()) ->
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{ok, State :: #state{}} | {ok, State :: #state{}, timeout() | hibernate} |
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{stop, Reason :: term()} | ignore).
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init([Port]) ->
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%% 需要提高进程的调度优先级
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erlang:process_flag(priority, high),
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Opts = [
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binary,
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{reuseaddr, true},
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{reuseport, true},
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{active, true},
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{recbuf, 5 * 1024 * 1024},
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{sndbuf, 5 * 1024 * 1024}
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],
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{ok, Socket} = gen_udp:open(Port, Opts),
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inet_udp:controlling_process(Socket, self()),
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logger:debug("[sdlan_stun] start at port: ~p", [Port]),
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{ok, #state{socket = Socket}}.
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%% @private
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%% @doc Handling call messages
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-spec(handle_call(Request :: term(), From :: {pid(), Tag :: term()},
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State :: #state{}) ->
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{reply, Reply :: term(), NewState :: #state{}} |
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{reply, Reply :: term(), NewState :: #state{}, timeout() | hibernate} |
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{noreply, NewState :: #state{}} |
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{noreply, NewState :: #state{}, timeout() | hibernate} |
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{stop, Reason :: term(), Reply :: term(), NewState :: #state{}} |
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{stop, Reason :: term(), NewState :: #state{}}).
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handle_call(_Request, _From, State = #state{}) ->
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{reply, ok, State}.
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%% @private
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%% @doc Handling cast messages
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-spec(handle_cast(Request :: term(), State :: #state{}) ->
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{noreply, NewState :: #state{}} |
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{noreply, NewState :: #state{}, timeout() | hibernate} |
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{stop, Reason :: term(), NewState :: #state{}}).
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%% 当前node下的转发，基于进程间的通讯
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handle_cast(_Request, State) ->
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{noreply, State}.
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%% @private
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%% @doc Handling all non call/cast messages
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-spec(handle_info(Info :: timeout() | term(), State :: #state{}) ->
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{noreply, NewState :: #state{}} |
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{noreply, NewState :: #state{}, timeout() | hibernate} |
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{stop, Reason :: term(), NewState :: #state{}}).
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handle_info({udp, Sock, Ip, Port, IpPacket}, State = #state{socket = Sock}) ->
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case dns_resolver:resolve(IpPacket) of
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{ok, RespIpPacket} ->
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gen_udp:send(Sock, Ip, Port, RespIpPacket);
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{error, Reason} ->
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logger:debug("[dns_server] resolve dns query error: ~p", [Reason])
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end,
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{noreply, State};
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handle_info(Info, State) ->
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logger:error("[sdlan_stun] get a unknown message: ~p, channel will closed", [Info]),
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{noreply, State}.
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%% @private
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%% @doc This function is called by a gen_server when it is about to
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%% terminate. It should be the opposite of Module:init/1 and do any
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%% necessary cleaning up. When it returns, the gen_server terminates
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%% with Reason. The return value is ignored.
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-spec(terminate(Reason :: (normal | shutdown | {shutdown, term()} | term()),
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State :: #state{}) -> term()).
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terminate(_Reason, _State = #state{}) ->
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ok.
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%% @private
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%% @doc Convert process state when code is changed
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-spec(code_change(OldVsn :: term() | {down, term()}, State :: #state{},
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Extra :: term()) ->
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{ok, NewState :: #state{}} | {error, Reason :: term()}).
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code_change(_OldVsn, State = #state{}, _Extra) ->
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{ok, State}.
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%%%===================================================================
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%%% Internal functions
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%%%=================================================================== |