%% Copyright (c) 2011-2012, Loïc Hoguin %% Copyright (c) 2011, Anthony Ramine %% %% Permission to use, copy, modify, and/or distribute this software for any %% purpose with or without fee is hereby granted, provided that the above %% copyright notice and this permission notice appear in all copies. %% %% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES %% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF %% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR %% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES %% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN %% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF %% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. %% @doc HTTP protocol handler. %% %% The available options are: %%
%%
dispatch
The dispatch list for this protocol.
%%
max_empty_lines
Max number of empty lines before a request. %% Defaults to 5.
%%
timeout
Time in milliseconds before an idle %% connection is closed. Defaults to 5000 milliseconds.
%%
urldecode
Function and options argument to use when decoding %% URL encoded strings. Defaults to `{fun cowboy_http:urldecode/2, crash}'. %%
%%
%% %% Note that there is no need to monitor these processes when using Cowboy as %% an application as it already supervises them under the listener supervisor. %% %% @see cowboy_dispatcher %% @see cowboy_http_handler -module(cowboy_protocol). %% API. -export([start_link/4]). %% Internal. -export([init/4]). -export([parse_request/1]). -export([handler_loop/3]). -type onrequest_fun() :: fun((Req) -> Req). -type onresponse_fun() :: fun((cowboy_http:status(), cowboy_http:headers(), Req) -> Req). -export_type([onrequest_fun/0]). -export_type([onresponse_fun/0]). -record(state, { listener :: pid(), socket :: inet:socket(), transport :: module(), dispatch :: cowboy_dispatcher:dispatch_rules(), handler :: {module(), any()}, onrequest :: undefined | onrequest_fun(), onresponse = undefined :: undefined | onresponse_fun(), urldecode :: {fun((binary(), T) -> binary()), T}, req_empty_lines = 0 :: integer(), max_empty_lines :: integer(), req_keepalive = 1 :: integer(), max_keepalive :: integer(), max_request_line_length :: integer(), max_header_name_length :: integer(), max_header_value_length :: integer(), timeout :: timeout(), buffer = <<>> :: binary(), host_tokens = undefined :: undefined | cowboy_dispatcher:tokens(), path_tokens = undefined :: undefined | '*' | cowboy_dispatcher:tokens(), hibernate = false :: boolean(), loop_timeout = infinity :: timeout(), loop_timeout_ref :: undefined | reference() }). %% API. %% @doc Start an HTTP protocol process. -spec start_link(pid(), inet:socket(), module(), any()) -> {ok, pid()}. start_link(ListenerPid, Socket, Transport, Opts) -> Pid = spawn_link(?MODULE, init, [ListenerPid, Socket, Transport, Opts]), {ok, Pid}. %% Internal. %% @doc Faster alternative to proplists:get_value/3. %% @private get_value(Key, Opts, Default) -> case lists:keyfind(Key, 1, Opts) of {_, Value} -> Value; _ -> Default end. %% @private -spec init(pid(), inet:socket(), module(), any()) -> ok. init(ListenerPid, Socket, Transport, Opts) -> Dispatch = get_value(dispatch, Opts, []), MaxEmptyLines = get_value(max_empty_lines, Opts, 5), MaxKeepalive = get_value(max_keepalive, Opts, infinity), MaxRequestLineLength = get_value(max_request_line_length, Opts, 4096), MaxHeaderNameLength = get_value(max_header_name_length, Opts, 64), MaxHeaderValueLength = get_value(max_header_value_length, Opts, 4096), OnRequest = get_value(onrequest, Opts, undefined), OnResponse = get_value(onresponse, Opts, undefined), Timeout = get_value(timeout, Opts, 5000), URLDecDefault = {fun cowboy_http:urldecode/2, crash}, URLDec = get_value(urldecode, Opts, URLDecDefault), ok = ranch:accept_ack(ListenerPid), wait_request(#state{listener=ListenerPid, socket=Socket, transport=Transport, dispatch=Dispatch, max_empty_lines=MaxEmptyLines, max_keepalive=MaxKeepalive, max_request_line_length=MaxRequestLineLength, max_header_name_length=MaxHeaderNameLength, max_header_value_length=MaxHeaderValueLength, timeout=Timeout, onrequest=OnRequest, onresponse=OnResponse, urldecode=URLDec}). -spec wait_request(#state{}) -> ok. wait_request(State=#state{socket=Socket, transport=Transport, timeout=T, buffer=Buffer}) -> case Transport:recv(Socket, 0, T) of {ok, Data} -> parse_request(State#state{ buffer= << Buffer/binary, Data/binary >>}); {error, _Reason} -> terminate(State) end. %% @private -spec parse_request(#state{}) -> ok. %% Empty lines must be using \r\n. parse_request(State=#state{buffer= << "\n", _/binary >>}) -> error_terminate(400, State); %% We limit the length of the Request-line to MaxLength to avoid endlessly %% reading from the socket and eventually crashing. parse_request(State=#state{buffer=Buffer, max_request_line_length=MaxLength, req_empty_lines=ReqEmpty, max_empty_lines=MaxEmpty}) -> case binary:match(Buffer, <<"\r\n">>) of nomatch when byte_size(Buffer) > MaxLength -> error_terminate(413, State); nomatch -> wait_request(State); {0, _} when ReqEmpty =:= MaxEmpty -> error_terminate(400, State); {0, _} -> << _:16, Rest/binary >> = Buffer, parse_request(State#state{ buffer=Rest, req_empty_lines=ReqEmpty + 1}); {Pos, _} -> << RequestLine:Pos/binary, _:16, Rest/binary >> = Buffer, case cowboy_http:request_line(RequestLine) of {Method, AbsPath, Version} -> request(State#state{buffer=Rest}, Method, AbsPath, Version); {error, _} -> error_terminate(400, State) end end. -spec request(#state{}, binary(), binary(), cowboy_http:version()) -> ok. request(State, _, _, Version) when Version =/= {1, 0}, Version =/= {1, 1} -> error_terminate(505, State); request(State=#state{socket=Socket, transport=Transport, onresponse=OnResponse, urldecode=URLDec}, Method, <<"*">>, Version) -> Connection = version_to_connection(State, Version), parse_header(State#state{path_tokens= '*'}, cowboy_req:new(Socket, Transport, Connection, Method, Version, <<"*">>, <<>>, OnResponse, URLDec)); request(State=#state{socket=Socket, transport=Transport, onresponse=OnResponse, urldecode=URLDec={URLDecFun, URLDecArg}}, Method, AbsPath, Version) -> Connection = version_to_connection(State, Version), {PathTokens, Path, Qs} = cowboy_dispatcher:split_path(AbsPath, fun(Bin) -> URLDecFun(Bin, URLDecArg) end), parse_header(State#state{path_tokens=PathTokens}, cowboy_req:new(Socket, Transport, Connection, Method, Version, Path, Qs, OnResponse, URLDec)). -spec parse_header(#state{}, cowboy_req:req()) -> ok. parse_header(State=#state{buffer= << "\r\n", Rest/binary >>}, Req) -> header_end(State#state{buffer=Rest}, Req); parse_header(State=#state{buffer=Buffer, max_header_name_length=MaxLength}, Req) -> case binary:match(Buffer, <<":">>) of nomatch when byte_size(Buffer) > MaxLength -> error_terminate(413, State); nomatch -> wait_header(State, Req, fun parse_header/2); {Pos, _} -> << Name:Pos/binary, _:8, Rest/binary >> = Buffer, Name2 = cowboy_bstr:to_lower(Name), Rest2 = cowboy_http:whitespace(Rest, fun(D) -> D end), parse_header_value(State#state{buffer=Rest2}, Req, Name2, <<>>) end. parse_header_value(State=#state{buffer=Buffer, max_header_value_length=MaxLength}, Req, Name, SoFar) -> case binary:match(Buffer, <<"\r\n">>) of nomatch when byte_size(Buffer) + byte_size(SoFar) > MaxLength -> error_terminate(413, State); nomatch -> wait_header(State, Req, fun(S, R) -> parse_header_value(S, R, Name, SoFar) end); {Pos, _} when Pos + 2 =:= byte_size(Buffer) -> wait_header(State, Req, fun(S, R) -> parse_header_value(S, R, Name, SoFar) end); {Pos, _} -> << Value:Pos/binary, _:16, Rest/binary >> = Buffer, case binary:at(Buffer, Pos + 2) of C when C =:= $\s; C =:= $\t -> parse_header_value(State#state{buffer=Rest}, Req, Name, << SoFar/binary, Value/binary >>); _ -> header(State#state{buffer=Rest}, Req, Name, << SoFar/binary, Value/binary >>) end end. -spec wait_header(#state{}, cowboy_req:req(), fun()) -> ok. wait_header(State=#state{socket=Socket, transport=Transport, timeout=T, buffer=Buffer}, Req, Fun) -> case Transport:recv(Socket, 0, T) of {ok, Data} -> Fun(State#state{ buffer= << Buffer/binary, Data/binary >>}, Req); {error, timeout} -> error_terminate(408, State); {error, closed} -> terminate(State) end. -spec header(#state{}, cowboy_req:req(), binary(), binary()) -> ok. header(State=#state{host_tokens=undefined, transport=Transport}, Req, <<"host">>, RawHost) -> RawHost2 = cowboy_bstr:to_lower(RawHost), case catch cowboy_dispatcher:split_host(RawHost2) of {HostTokens, Host, undefined} -> Port = default_port(Transport:name()), parse_header(State#state{host_tokens=HostTokens}, cowboy_req:set_host(Host, Port, RawHost, Req)); {HostTokens, Host, Port} -> parse_header(State#state{host_tokens=HostTokens}, cowboy_req:set_host(Host, Port, RawHost, Req)); {'EXIT', _Reason} -> error_terminate(400, State) end; %% Ignore Host headers if we already have it. header(State, Req, <<"host">>, _) -> parse_header(State, Req); header(State=#state{req_keepalive=Keepalive, max_keepalive=MaxKeepalive}, Req, <<"connection">>, Connection) when Keepalive < MaxKeepalive -> parse_header(State, cowboy_req:set_connection(Connection, Req)); header(State, Req, Name, Value) -> parse_header(State, cowboy_req:add_header(Name, Value, Req)). %% The Host header is required in HTTP/1.1 and optional in HTTP/1.0. header_end(State=#state{host_tokens=undefined, buffer=Buffer, transport=Transport}, Req) -> case cowboy_req:version(Req) of {{1, 1}, _} -> error_terminate(400, State); {{1, 0}, Req2} -> Port = default_port(Transport:name()), onrequest( cowboy_req:set_buffer(Buffer, cowboy_req:set_host(<<>>, Port, <<>>, Req2)), State#state{buffer= <<>>, host_tokens=[]}) end; header_end(State=#state{buffer=Buffer}, Req) -> onrequest(cowboy_req:set_buffer(Buffer, Req), State#state{buffer= <<>>}). %% Call the global onrequest callback. The callback can send a reply, %% in which case we consider the request handled and move on to the next %% one. Note that since we haven't dispatched yet, we don't know the %% handler, host_info, path_info or bindings yet. -spec onrequest(cowboy_req:req(), #state{}) -> ok. onrequest(Req, State=#state{onrequest=undefined}) -> dispatch(Req, State); onrequest(Req, State=#state{onrequest=OnRequest}) -> Req2 = OnRequest(Req), case cowboy_req:get_resp_state(Req2) of waiting -> dispatch(Req2, State); _ -> next_request(Req2, State, ok) end. -spec dispatch(cowboy_req:req(), #state{}) -> ok. dispatch(Req, State=#state{dispatch=Dispatch, host_tokens=HostTokens, path_tokens=PathTokens}) -> case cowboy_dispatcher:match(HostTokens, PathTokens, Dispatch) of {ok, Handler, Opts, Bindings, HostInfo, PathInfo} -> Req2 = cowboy_req:set_bindings(HostInfo, PathInfo, Bindings, Req), handler_init(Req2, State#state{handler={Handler, Opts}, host_tokens=undefined, path_tokens=undefined}); {error, notfound, host} -> error_terminate(400, State); {error, notfound, path} -> error_terminate(404, State) end. -spec handler_init(cowboy_req:req(), #state{}) -> ok. handler_init(Req, State=#state{transport=Transport, handler={Handler, Opts}}) -> try Handler:init({Transport:name(), http}, Req, Opts) of {ok, Req2, HandlerState} -> handler_handle(HandlerState, Req2, State); {loop, Req2, HandlerState} -> handler_before_loop(HandlerState, Req2, State); {loop, Req2, HandlerState, hibernate} -> handler_before_loop(HandlerState, Req2, State#state{hibernate=true}); {loop, Req2, HandlerState, Timeout} -> handler_before_loop(HandlerState, Req2, State#state{loop_timeout=Timeout}); {loop, Req2, HandlerState, Timeout, hibernate} -> handler_before_loop(HandlerState, Req2, State#state{hibernate=true, loop_timeout=Timeout}); {shutdown, Req2, HandlerState} -> handler_terminate(HandlerState, Req2, State); %% @todo {upgrade, transport, Module} {upgrade, protocol, Module} -> upgrade_protocol(Req, State, Module) catch Class:Reason -> error_terminate(500, State), PLReq = cowboy_req:to_list(Req), error_logger:error_msg( "** Handler ~p terminating in init/3~n" " for the reason ~p:~p~n" "** Options were ~p~n" "** Request was ~p~n** Stacktrace: ~p~n~n", [Handler, Class, Reason, Opts, PLReq, erlang:get_stacktrace()]) end. -spec upgrade_protocol(cowboy_req:req(), #state{}, atom()) -> ok. upgrade_protocol(Req, State=#state{listener=ListenerPid, handler={Handler, Opts}}, Module) -> case Module:upgrade(ListenerPid, Handler, Opts, Req) of {UpgradeRes, Req2} -> next_request(Req2, State, UpgradeRes); _Any -> terminate(State) end. -spec handler_handle(any(), cowboy_req:req(), #state{}) -> ok. handler_handle(HandlerState, Req, State=#state{handler={Handler, Opts}}) -> try Handler:handle(Req, HandlerState) of {ok, Req2, HandlerState2} -> terminate_request(HandlerState2, Req2, State) catch Class:Reason -> PLReq = cowboy_req:to_list(Req), error_logger:error_msg( "** Handler ~p terminating in handle/2~n" " for the reason ~p:~p~n" "** Options were ~p~n** Handler state was ~p~n" "** Request was ~p~n** Stacktrace: ~p~n~n", [Handler, Class, Reason, Opts, HandlerState, PLReq, erlang:get_stacktrace()]), handler_terminate(HandlerState, Req, State), error_terminate(500, State) end. %% We don't listen for Transport closes because that would force us %% to receive data and buffer it indefinitely. -spec handler_before_loop(any(), cowboy_req:req(), #state{}) -> ok. handler_before_loop(HandlerState, Req, State=#state{hibernate=true}) -> State2 = handler_loop_timeout(State), catch erlang:hibernate(?MODULE, handler_loop, [HandlerState, Req, State2#state{hibernate=false}]), ok; handler_before_loop(HandlerState, Req, State) -> State2 = handler_loop_timeout(State), handler_loop(HandlerState, Req, State2). %% Almost the same code can be found in cowboy_websocket. -spec handler_loop_timeout(#state{}) -> #state{}. handler_loop_timeout(State=#state{loop_timeout=infinity}) -> State#state{loop_timeout_ref=undefined}; handler_loop_timeout(State=#state{loop_timeout=Timeout, loop_timeout_ref=PrevRef}) -> _ = case PrevRef of undefined -> ignore; PrevRef -> erlang:cancel_timer(PrevRef) end, TRef = erlang:start_timer(Timeout, self(), ?MODULE), State#state{loop_timeout_ref=TRef}. -spec handler_loop(any(), cowboy_req:req(), #state{}) -> ok. handler_loop(HandlerState, Req, State=#state{loop_timeout_ref=TRef}) -> receive {timeout, TRef, ?MODULE} -> terminate_request(HandlerState, Req, State); {timeout, OlderTRef, ?MODULE} when is_reference(OlderTRef) -> handler_loop(HandlerState, Req, State); Message -> handler_call(HandlerState, Req, State, Message) end. -spec handler_call(any(), cowboy_req:req(), #state{}, any()) -> ok. handler_call(HandlerState, Req, State=#state{handler={Handler, Opts}}, Message) -> try Handler:info(Message, Req, HandlerState) of {ok, Req2, HandlerState2} -> terminate_request(HandlerState2, Req2, State); {loop, Req2, HandlerState2} -> handler_before_loop(HandlerState2, Req2, State); {loop, Req2, HandlerState2, hibernate} -> handler_before_loop(HandlerState2, Req2, State#state{hibernate=true}) catch Class:Reason -> PLReq = cowboy_req:to_list(Req), error_logger:error_msg( "** Handler ~p terminating in info/3~n" " for the reason ~p:~p~n" "** Options were ~p~n** Handler state was ~p~n" "** Request was ~p~n** Stacktrace: ~p~n~n", [Handler, Class, Reason, Opts, HandlerState, PLReq, erlang:get_stacktrace()]), handler_terminate(HandlerState, Req, State), error_terminate(500, State) end. -spec handler_terminate(any(), cowboy_req:req(), #state{}) -> ok. handler_terminate(HandlerState, Req, #state{handler={Handler, Opts}}) -> try Handler:terminate(cowboy_req:lock(Req), HandlerState) catch Class:Reason -> PLReq = cowboy_req:to_list(Req), error_logger:error_msg( "** Handler ~p terminating in terminate/2~n" " for the reason ~p:~p~n" "** Options were ~p~n** Handler state was ~p~n" "** Request was ~p~n** Stacktrace: ~p~n~n", [Handler, Class, Reason, Opts, HandlerState, PLReq, erlang:get_stacktrace()]) end. -spec terminate_request(any(), cowboy_req:req(), #state{}) -> ok. terminate_request(HandlerState, Req, State) -> HandlerRes = handler_terminate(HandlerState, Req, State), next_request(Req, State, HandlerRes). -spec next_request(cowboy_req:req(), #state{}, any()) -> ok. next_request(Req, State=#state{ req_keepalive=Keepalive}, HandlerRes) -> cowboy_req:ensure_response(Req, 204), {BodyRes, Buffer} = case cowboy_req:skip_body(Req) of {ok, Req2} -> {ok, cowboy_req:get_buffer(Req2)}; {error, _} -> {close, <<>>} end, %% Flush the resp_sent message before moving on. receive {cowboy_req, resp_sent} -> ok after 0 -> ok end, case {HandlerRes, BodyRes, cowboy_req:get_connection(Req)} of {ok, ok, keepalive} -> ?MODULE:parse_request(State#state{ buffer=Buffer, host_tokens=undefined, path_tokens=undefined, req_empty_lines=0, req_keepalive=Keepalive + 1}); _Closed -> terminate(State) end. %% Only send an error reply if there is no resp_sent message. -spec error_terminate(cowboy_http:status(), #state{}) -> ok. error_terminate(Code, State=#state{socket=Socket, transport=Transport, onresponse=OnResponse}) -> receive {cowboy_req, resp_sent} -> ok after 0 -> _ = cowboy_req:reply(Code, cowboy_req:new(Socket, Transport, close, <<"GET">>, {1, 1}, <<>>, <<>>, OnResponse, undefined)), ok end, terminate(State). -spec terminate(#state{}) -> ok. terminate(#state{socket=Socket, transport=Transport}) -> Transport:close(Socket), ok. %% Internal. -spec version_to_connection(#state{}, cowboy_http:version()) -> keepalive | close. version_to_connection(#state{req_keepalive=Keepalive, max_keepalive=MaxKeepalive}, _) when Keepalive >= MaxKeepalive -> close; version_to_connection(_, {1, 1}) -> keepalive; version_to_connection(_, _) -> close. -spec default_port(atom()) -> 80 | 443. default_port(ssl) -> 443; default_port(_) -> 80.