%% 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 keep-alive %% connection is closed. Defaults to 5000 milliseconds.
%%
%% %% 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). -export([start_link/3]). %% API. -export([init/3, parse_request/1]). %% FSM. -include("include/http.hrl"). -record(state, { socket :: inet:socket(), transport :: module(), dispatch :: cowboy_dispatcher:dispatch_rules(), handler :: {module(), any()}, req_empty_lines = 0 :: integer(), max_empty_lines :: integer(), timeout :: timeout(), connection = keepalive :: keepalive | close, buffer = <<>> :: binary() }). %% API. %% @doc Start an HTTP protocol process. -spec start_link(inet:socket(), module(), any()) -> {ok, pid()}. start_link(Socket, Transport, Opts) -> Pid = spawn_link(?MODULE, init, [Socket, Transport, Opts]), {ok, Pid}. %% FSM. %% @private -spec init(inet:socket(), module(), any()) -> ok. init(Socket, Transport, Opts) -> Dispatch = proplists:get_value(dispatch, Opts, []), MaxEmptyLines = proplists:get_value(max_empty_lines, Opts, 5), Timeout = proplists:get_value(timeout, Opts, 5000), wait_request(#state{socket=Socket, transport=Transport, dispatch=Dispatch, max_empty_lines=MaxEmptyLines, timeout=Timeout}). %% @private -spec parse_request(#state{}) -> ok. %% @todo Use decode_packet options to limit length? parse_request(State=#state{buffer=Buffer}) -> case erlang:decode_packet(http_bin, Buffer, []) of {ok, Request, Rest} -> request(Request, State#state{buffer=Rest}); {more, _Length} -> wait_request(State); {error, _Reason} -> error_response(400, State) end. -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, timeout} -> error_terminate(408, State); {error, closed} -> terminate(State) end. -spec request({http_request, http_method(), http_uri(), http_version()}, #state{}) -> ok. %% @todo We probably want to handle some things differently between versions. request({http_request, _Method, _URI, Version}, State) when Version =/= {1, 0}, Version =/= {1, 1} -> error_terminate(505, State); %% @todo We need to cleanup the URI properly. request({http_request, Method, {abs_path, AbsPath}, Version}, State=#state{socket=Socket, transport=Transport}) -> {Path, RawPath, Qs} = cowboy_dispatcher:split_path(AbsPath), 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}, State#state{connection=ConnAtom}); request({http_request, Method, '*', Version}, State=#state{socket=Socket, transport=Transport}) -> ConnAtom = version_to_connection(Version), parse_header(#http_req{socket=Socket, transport=Transport, connection=ConnAtom, method=Method, version=Version, path='*', raw_path= <<"*">>, raw_qs= <<>>}, State#state{connection=ConnAtom}); 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({http_error, _Any}, State) -> error_terminate(400, State). -spec parse_header(#http_req{}, #state{}) -> ok. parse_header(Req, State=#state{buffer=Buffer}) -> case erlang:decode_packet(httph_bin, Buffer, []) of {ok, Header, Rest} -> header(Header, Req, State#state{buffer=Rest}); {more, _Length} -> wait_header(Req, State); {error, _Reason} -> error_response(400, State) end. -spec wait_header(#http_req{}, #state{}) -> ok. 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. header({http_header, _I, 'Host', _R, RawHost}, Req=#http_req{ transport=Transport, host=undefined}, State) -> RawHost2 = binary_to_lower(RawHost), case catch cowboy_dispatcher:split_host(RawHost2) of {Host, RawHost3, undefined} -> Port = default_port(Transport:name()), dispatch(Req#http_req{host=Host, raw_host=RawHost3, port=Port, headers=[{'Host', RawHost3}|Req#http_req.headers]}, State); {Host, RawHost3, Port} -> dispatch(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, State) -> ConnAtom = connection_to_atom(Connection), parse_header(Req#http_req{connection=ConnAtom, headers=[{'Connection', Connection}|Req#http_req.headers]}, State#state{connection=ConnAtom}); header({http_header, _I, Field, _R, Value}, Req, State) -> parse_header(Req#http_req{headers=[{Field, Value}|Req#http_req.headers]}, State); %% The Host header is required. header(http_eoh, #http_req{host=undefined}, State) -> error_terminate(400, State); header(http_eoh, Req, State=#state{buffer=Buffer}) -> handler_init(Req#http_req{buffer=Buffer}, State#state{buffer= <<>>}); header({http_error, _Bin}, _Req, State) -> error_terminate(500, State). -spec dispatch(#http_req{}, #state{}) -> ok. dispatch(Req=#http_req{host=Host, path=Path}, State=#state{dispatch=Dispatch}) -> %% @todo We probably want to filter the Host and Path here to allow %% things like url rewriting. case cowboy_dispatcher:match(Host, Path, Dispatch) of {ok, Handler, Opts, Binds, HostInfo, PathInfo} -> parse_header(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. handler_init(Req, State=#state{ transport=Transport, handler={Handler, Opts}}) -> try Handler:init({Transport:name(), http}, Req, Opts) of {ok, Req2, HandlerState} -> handler_loop(HandlerState, Req2, State); %% @todo {upgrade, transport, Module} {upgrade, protocol, Module} -> Module:upgrade(Handler, Opts, Req) catch Class:Reason -> error_terminate(500, State), error_logger:error_msg( "** Handler ~p terminating in init/3 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 handler_loop(any(), #http_req{}, #state{}) -> ok. handler_loop(HandlerState, Req, State=#state{handler={Handler, Opts}}) -> try Handler:handle(Req#http_req{resp_state=waiting}, HandlerState) of {ok, Req2, HandlerState2} -> next_request(HandlerState2, Req2, State) catch Class:Reason -> error_logger:error_msg( "** Handler ~p terminating in handle/2 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. -spec handler_terminate(any(), #http_req{}, #state{}) -> ok | error. 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 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()]), error end. -spec next_request(any(), #http_req{}, #state{}) -> ok. next_request(HandlerState, Req=#http_req{buffer=Buffer}, State) -> HandlerRes = handler_terminate(HandlerState, Req, State), BodyRes = ensure_body_processed(Req), RespRes = ensure_response(Req, State), case {HandlerRes, BodyRes, RespRes, State#state.connection} of {ok, ok, ok, keepalive} -> ?MODULE:parse_request(State#state{buffer=Buffer}); _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{}, #state{}) -> ok. %% The handler has already fully replied to the client. ensure_response(#http_req{resp_state=done}, _State) -> ok; %% No response has been sent but everything apparently went fine. %% Reply with 204 No Content to indicate this. ensure_response(#http_req{resp_state=waiting}, State) -> error_response(204, State); %% Close the chunked reply. ensure_response(#http_req{socket=Socket, transport=Transport, resp_state=chunks}, _State) -> Transport:send(Socket, <<"0\r\n\r\n">>), close. -spec error_response(http_status(), #state{}) -> ok. error_response(Code, #state{socket=Socket, transport=Transport, connection=Connection}) -> _ = cowboy_http_req:reply(Code, [], [], #http_req{ socket=Socket, transport=Transport, connection=Connection, resp_state=waiting}), ok. -spec error_terminate(http_status(), #state{}) -> ok. error_terminate(Code, State) -> error_response(Code, State#state{connection=close}), 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 connection_to_atom(binary()) -> keepalive | close. connection_to_atom(<<"keep-alive">>) -> keepalive; connection_to_atom(<<"close">>) -> close; connection_to_atom(Connection) -> case binary_to_lower(Connection) of <<"close">> -> close; _Any -> keepalive end. -spec default_port(atom()) -> 80 | 443. default_port(ssl) -> 443; default_port(_) -> 80. %% We are excluding a few characters on purpose. -spec binary_to_lower(binary()) -> binary(). binary_to_lower(L) -> << << (char_to_lower(C)) >> || << C >> <= L >>. %% We gain noticeable speed by matching each value directly. -spec char_to_lower(char()) -> char(). char_to_lower($A) -> $a; char_to_lower($B) -> $b; char_to_lower($C) -> $c; char_to_lower($D) -> $d; char_to_lower($E) -> $e; char_to_lower($F) -> $f; char_to_lower($G) -> $g; char_to_lower($H) -> $h; char_to_lower($I) -> $i; char_to_lower($J) -> $j; char_to_lower($K) -> $k; char_to_lower($L) -> $l; char_to_lower($M) -> $m; char_to_lower($N) -> $n; char_to_lower($O) -> $o; char_to_lower($P) -> $p; char_to_lower($Q) -> $q; char_to_lower($R) -> $r; char_to_lower($S) -> $s; char_to_lower($T) -> $t; char_to_lower($U) -> $u; char_to_lower($V) -> $v; char_to_lower($W) -> $w; char_to_lower($X) -> $x; char_to_lower($Y) -> $y; char_to_lower($Z) -> $z; char_to_lower(Ch) -> Ch.