%% Copyright (c) 2011, 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_http_protocol). -behaviour(cowboy_protocol). -export([start_link/4]). %% API. -export([init/4, parse_request/1, handler_loop/3]). %% FSM. -include("include/http.hrl"). -include_lib("eunit/include/eunit.hrl"). -record(state, { listener :: pid(), socket :: inet:socket(), transport :: module(), dispatch :: cowboy_dispatcher:dispatch_rules(), handler :: {module(), any()}, urldecode :: {fun((binary(), T) -> binary()), T}, req_empty_lines = 0 :: integer(), max_empty_lines :: integer(), req_keepalive = 1 :: integer(), max_keepalive :: integer(), max_line_length :: integer(), timeout :: timeout(), buffer = <<>> :: binary(), 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}. %% FSM. %% @private -spec init(pid(), inet:socket(), module(), any()) -> ok | none(). init(ListenerPid, Socket, Transport, Opts) -> Dispatch = proplists:get_value(dispatch, Opts, []), MaxEmptyLines = proplists:get_value(max_empty_lines, Opts, 5), MaxKeepalive = proplists:get_value(max_keepalive, Opts, infinity), MaxLineLength = proplists:get_value(max_line_length, Opts, 4096), Timeout = proplists:get_value(timeout, Opts, 5000), URLDecDefault = {fun cowboy_http:urldecode/2, crash}, URLDec = proplists:get_value(urldecode, Opts, URLDecDefault), ok = cowboy:accept_ack(ListenerPid), wait_request(#state{listener=ListenerPid, socket=Socket, transport=Transport, dispatch=Dispatch, max_empty_lines=MaxEmptyLines, max_keepalive=MaxKeepalive, max_line_length=MaxLineLength, timeout=Timeout, urldecode=URLDec}). %% @private -spec parse_request(#state{}) -> ok | none(). %% 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_line_length=MaxLength}) -> case erlang:decode_packet(http_bin, Buffer, []) of {ok, Request, Rest} -> request(Request, State#state{buffer=Rest}); {more, _Length} when byte_size(Buffer) > MaxLength -> error_terminate(413, State); {more, _Length} -> wait_request(State); {error, _Reason} -> error_terminate(400, State) end. -spec wait_request(#state{}) -> ok | none(). 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. -spec request({http_request, http_method(), http_uri(), http_version()}, #state{}) -> ok | none(). request({http_request, _Method, _URI, Version}, State) when Version =/= {1, 0}, Version =/= {1, 1} -> error_terminate(505, State); request({http_request, Method, {abs_path, AbsPath}, Version}, State=#state{socket=Socket, transport=Transport, urldecode={URLDecFun, URLDecArg}=URLDec}) -> URLDecode = fun(Bin) -> URLDecFun(Bin, URLDecArg) end, {Path, RawPath, Qs} = cowboy_dispatcher:split_path(AbsPath, URLDecode), ConnAtom = version_to_connection(Version), parse_header(#http_req{socket=Socket, transport=Transport, connection=ConnAtom, method=Method, version=Version, path=Path, raw_path=RawPath, raw_qs=Qs, urldecode=URLDec}, State); request({http_request, Method, '*', Version}, State=#state{socket=Socket, transport=Transport, urldecode=URLDec}) -> ConnAtom = version_to_connection(Version), parse_header(#http_req{socket=Socket, transport=Transport, connection=ConnAtom, method=Method, version=Version, path='*', raw_path= <<"*">>, raw_qs= <<>>, urldecode=URLDec}, State); request({http_request, _Method, _URI, _Version}, State) -> error_terminate(501, State); request({http_error, <<"\r\n">>}, State=#state{req_empty_lines=N, max_empty_lines=N}) -> error_terminate(400, State); request({http_error, <<"\r\n">>}, State=#state{req_empty_lines=N}) -> parse_request(State#state{req_empty_lines=N + 1}); request(_Any, State) -> error_terminate(400, State). -spec parse_header(#http_req{}, #state{}) -> ok | none(). parse_header(Req, State=#state{buffer=Buffer, max_line_length=MaxLength}) -> case erlang:decode_packet(httph_bin, Buffer, []) of {ok, Header, Rest} -> header(Header, Req, State#state{buffer=Rest}); {more, _Length} when byte_size(Buffer) > MaxLength -> error_terminate(413, State); {more, _Length} -> wait_header(Req, State); {error, _Reason} -> error_terminate(400, State) end. -spec wait_header(#http_req{}, #state{}) -> ok | none(). wait_header(Req, State=#state{socket=Socket, transport=Transport, timeout=T, buffer=Buffer}) -> case Transport:recv(Socket, 0, T) of {ok, Data} -> parse_header(Req, State#state{ buffer= << Buffer/binary, Data/binary >>}); {error, timeout} -> error_terminate(408, State); {error, closed} -> terminate(State) end. -spec header({http_header, integer(), http_header(), any(), binary()} | http_eoh, #http_req{}, #state{}) -> ok | none(). header({http_header, _I, 'Host', _R, RawHost}, Req=#http_req{ transport=Transport, host=undefined}, State) -> RawHost2 = cowboy_bstr:to_lower(RawHost), case catch cowboy_dispatcher:split_host(RawHost2) of {Host, RawHost3, undefined} -> Port = default_port(Transport:name()), dispatch(fun parse_header/2, Req#http_req{ host=Host, raw_host=RawHost3, port=Port, headers=[{'Host', RawHost3}|Req#http_req.headers]}, State); {Host, RawHost3, Port} -> dispatch(fun parse_header/2, Req#http_req{ host=Host, raw_host=RawHost3, port=Port, headers=[{'Host', RawHost3}|Req#http_req.headers]}, State); {'EXIT', _Reason} -> error_terminate(400, State) end; %% Ignore Host headers if we already have it. header({http_header, _I, 'Host', _R, _V}, Req, State) -> parse_header(Req, State); header({http_header, _I, 'Connection', _R, Connection}, Req=#http_req{headers=Headers}, State) -> Req2 = Req#http_req{headers=[{'Connection', Connection}|Headers]}, {ConnTokens, Req3} = cowboy_http_req:parse_header('Connection', Req2), ConnAtom = cowboy_http:connection_to_atom(ConnTokens), parse_header(Req3#http_req{connection=ConnAtom}, State); header({http_header, _I, Field, _R, Value}, Req, State) -> Field2 = format_header(Field), parse_header(Req#http_req{headers=[{Field2, Value}|Req#http_req.headers]}, State); %% The Host header is required in HTTP/1.1. header(http_eoh, #http_req{version={1, 1}, host=undefined}, State) -> error_terminate(400, State); %% It is however optional in HTTP/1.0. header(http_eoh, Req=#http_req{version={1, 0}, transport=Transport, host=undefined}, State=#state{buffer=Buffer}) -> Port = default_port(Transport:name()), dispatch(fun handler_init/2, Req#http_req{host=[], raw_host= <<>>, port=Port, buffer=Buffer}, State#state{buffer= <<>>}); header(http_eoh, Req, State=#state{buffer=Buffer}) -> handler_init(Req#http_req{buffer=Buffer}, State#state{buffer= <<>>}); header(_Any, _Req, State) -> error_terminate(400, State). -spec dispatch(fun((#http_req{}, #state{}) -> ok), #http_req{}, #state{}) -> ok | none(). dispatch(Next, Req=#http_req{host=Host, path=Path}, State=#state{dispatch=Dispatch}) -> %% @todo We should allow a configurable chain of handlers here to %% allow things like url rewriting, site-wide authentication, %% optional dispatching, and more. It would default to what %% we are doing so far. case cowboy_dispatcher:match(Host, Path, Dispatch) of {ok, Handler, Opts, Binds, HostInfo, PathInfo} -> Next(Req#http_req{host_info=HostInfo, path_info=PathInfo, bindings=Binds}, State#state{handler={Handler, Opts}}); {error, notfound, host} -> error_terminate(400, State); {error, notfound, path} -> error_terminate(404, State) end. -spec handler_init(#http_req{}, #state{}) -> ok | none(). 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), 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, Req, erlang:get_stacktrace()]) end. -spec upgrade_protocol(#http_req{}, #state{}, atom()) -> ok | none(). 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(), #http_req{}, #state{}) -> ok | none(). 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 -> 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, Req, erlang:get_stacktrace()]), handler_terminate(HandlerState, Req, State), terminate(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(), #http_req{}, #state{}) -> ok | none(). handler_before_loop(HandlerState, Req, State=#state{hibernate=true}) -> State2 = handler_loop_timeout(State), erlang:hibernate(?MODULE, handler_loop, [HandlerState, Req, State2#state{hibernate=false}]); 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_http_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 = make_ref(), erlang:send_after(Timeout, self(), {?MODULE, timeout, TRef}), State#state{loop_timeout_ref=TRef}. -spec handler_loop(any(), #http_req{}, #state{}) -> ok | none(). handler_loop(HandlerState, Req, State=#state{loop_timeout_ref=TRef}) -> receive {?MODULE, timeout, TRef} -> terminate_request(HandlerState, Req, State); {?MODULE, timeout, OlderTRef} when is_reference(OlderTRef) -> handler_loop(HandlerState, Req, State); Message -> handler_call(HandlerState, Req, State, Message) end. -spec handler_call(any(), #http_req{}, #state{}, any()) -> ok | none(). 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 -> 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, Req, erlang:get_stacktrace()]) end. -spec handler_terminate(any(), #http_req{}, #state{}) -> ok. handler_terminate(HandlerState, Req, #state{handler={Handler, Opts}}) -> try Handler:terminate(Req#http_req{resp_state=locked}, HandlerState) catch Class:Reason -> 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, Req, erlang:get_stacktrace()]) end. -spec terminate_request(any(), #http_req{}, #state{}) -> ok | none(). terminate_request(HandlerState, Req, State) -> HandlerRes = handler_terminate(HandlerState, Req, State), next_request(Req, State, HandlerRes). -spec next_request(#http_req{}, #state{}, any()) -> ok | none(). next_request(Req=#http_req{connection=Conn, buffer=Buffer}, State=#state{req_keepalive=Keepalive, max_keepalive=MaxKeepalive}, HandlerRes) -> BodyRes = ensure_body_processed(Req), RespRes = ensure_response(Req), case {HandlerRes, BodyRes, RespRes, Conn} of {ok, ok, ok, keepalive} when Keepalive < MaxKeepalive -> ?MODULE:parse_request(State#state{ buffer=Buffer, req_empty_lines=0, req_keepalive=Keepalive + 1}); _Closed -> terminate(State) end. -spec ensure_body_processed(#http_req{}) -> ok | close. ensure_body_processed(#http_req{body_state=done}) -> ok; ensure_body_processed(Req=#http_req{body_state=waiting}) -> case cowboy_http_req:body(Req) of {error, badarg} -> ok; %% No body. {error, _Reason} -> close; _Any -> ok end. -spec ensure_response(#http_req{}) -> ok. %% The handler has already fully replied to the client. ensure_response(#http_req{resp_state=done}) -> ok; %% No response has been sent but everything apparently went fine. %% Reply with 204 No Content to indicate this. ensure_response(Req=#http_req{resp_state=waiting}) -> _ = cowboy_http_req:reply(204, [], [], Req), ok; %% Close the chunked reply. ensure_response(#http_req{method='HEAD', resp_state=chunks}) -> close; ensure_response(#http_req{socket=Socket, transport=Transport, resp_state=chunks}) -> Transport:send(Socket, <<"0\r\n\r\n">>), close. -spec error_terminate(http_status(), #state{}) -> ok. error_terminate(Code, State=#state{socket=Socket, transport=Transport}) -> _ = cowboy_http_req:reply(Code, [], [], #http_req{ socket=Socket, transport=Transport, connection=close, resp_state=waiting}), terminate(State). -spec terminate(#state{}) -> ok. terminate(#state{socket=Socket, transport=Transport}) -> Transport:close(Socket), ok. %% Internal. -spec version_to_connection(http_version()) -> keepalive | close. version_to_connection({1, 1}) -> keepalive; version_to_connection(_Any) -> close. -spec default_port(atom()) -> 80 | 443. default_port(ssl) -> 443; default_port(_) -> 80. %% @todo While 32 should be enough for everybody, we should probably make %% this configurable or something. -spec format_header(atom()) -> atom(); (binary()) -> binary(). format_header(Field) when is_atom(Field) -> Field; format_header(Field) when byte_size(Field) =< 20; byte_size(Field) > 32 -> Field; format_header(Field) -> format_header(Field, true, <<>>). -spec format_header(binary(), boolean(), binary()) -> binary(). format_header(<<>>, _Any, Acc) -> Acc; %% Replicate a bug in OTP for compatibility reasons when there's a - right %% after another. Proper use should always be 'true' instead of 'not Bool'. format_header(<< $-, Rest/bits >>, Bool, Acc) -> format_header(Rest, not Bool, << Acc/binary, $- >>); format_header(<< C, Rest/bits >>, true, Acc) -> format_header(Rest, false, << Acc/binary, (cowboy_bstr:char_to_upper(C)) >>); format_header(<< C, Rest/bits >>, false, Acc) -> format_header(Rest, false, << Acc/binary, (cowboy_bstr:char_to_lower(C)) >>). %% Tests. -ifdef(TEST). format_header_test_() -> %% {Header, Result} Tests = [ {<<"Sec-Websocket-Version">>, <<"Sec-Websocket-Version">>}, {<<"Sec-WebSocket-Version">>, <<"Sec-Websocket-Version">>}, {<<"sec-websocket-version">>, <<"Sec-Websocket-Version">>}, {<<"SEC-WEBSOCKET-VERSION">>, <<"Sec-Websocket-Version">>}, %% These last tests ensures we're formatting headers exactly like OTP. %% Even though it's dumb, it's better for compatibility reasons. {<<"Sec-WebSocket--Version">>, <<"Sec-Websocket--version">>}, {<<"Sec-WebSocket---Version">>, <<"Sec-Websocket---Version">>} ], [{H, fun() -> R = format_header(H) end} || {H, R} <- Tests]. -endif.