%% 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.
%%
max_header_name_length
Max length allowed for header names. %% Defaults to 64.
%%
max_header_value_length
Max length allowed for header values. %% Defaults to 4096.
%%
max_headers
Max number of headers allowed. %% Defaults to 100.
%%
max_keepalive
Max number of requests allowed in a single %% keep-alive session. Defaults to infinity.
%%
max_request_line_length
Max length allowed for the request %% line. Defaults to 4096.
%%
onrequest
Optional fun that allows Req interaction before %% any dispatching is done. Host info, path info and bindings are thus %% not available at this point.
%%
onresponse
Optional fun that allows replacing a response %% sent by the application.
%%
timeout
Time in milliseconds before an idle %% 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_protocol). %% API. -export([start_link/4]). %% Internal. -export([init/4]). -export([parse_request/3]). -export([handler_loop/4]). -type onrequest_fun() :: fun((Req) -> Req). -type onresponse_fun() :: fun((cowboy_http:status(), cowboy_http:headers(), iodata(), 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(), onrequest :: undefined | onrequest_fun(), onresponse = undefined :: undefined | onresponse_fun(), max_empty_lines :: non_neg_integer(), req_keepalive = 1 :: non_neg_integer(), max_keepalive :: non_neg_integer(), max_request_line_length :: non_neg_integer(), max_header_name_length :: non_neg_integer(), max_header_value_length :: non_neg_integer(), max_headers :: non_neg_integer(), timeout :: timeout(), 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), MaxHeaderNameLength = get_value(max_header_name_length, Opts, 64), MaxHeaderValueLength = get_value(max_header_value_length, Opts, 4096), MaxHeaders = get_value(max_headers, Opts, 100), MaxKeepalive = get_value(max_keepalive, Opts, infinity), MaxRequestLineLength = get_value(max_request_line_length, Opts, 4096), OnRequest = get_value(onrequest, Opts, undefined), OnResponse = get_value(onresponse, Opts, undefined), Timeout = get_value(timeout, Opts, 5000), 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, max_headers=MaxHeaders, timeout=Timeout, onrequest=OnRequest, onresponse=OnResponse}, 0). %% Request parsing. %% %% The next set of functions is the request parsing code. All of it %% runs using a single binary match context. This optimization ends %% right after the header parsing is finished and the code becomes %% more interesting past that point. -spec wait_request(binary(), #state{}, non_neg_integer()) -> ok. wait_request(Buffer, State=#state{socket=Socket, transport=Transport, timeout=Timeout}, ReqEmpty) -> case Transport:recv(Socket, 0, Timeout) of {ok, Data} -> parse_request(<< Buffer/binary, Data/binary >>, State, ReqEmpty); {error, _} -> terminate(State) end. %% @private -spec parse_request(binary(), #state{}, non_neg_integer()) -> ok. %% Empty lines must be using \r\n. parse_request(<< $\n, _/binary >>, State, _) -> 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(Buffer, State=#state{max_request_line_length=MaxLength, max_empty_lines=MaxEmpty}, ReqEmpty) -> case binary:match(Buffer, <<"\n">>) of nomatch when byte_size(Buffer) > MaxLength -> error_terminate(414, State); nomatch -> wait_request(Buffer, State, ReqEmpty); {1, _} when ReqEmpty =:= MaxEmpty -> error_terminate(400, State); {1, _} -> << _:16, Rest/binary >> = Buffer, parse_request(Rest, State, ReqEmpty + 1); {_, _} -> parse_method(Buffer, State, <<>>) end. parse_method(<< C, Rest/bits >>, State, SoFar) -> case C of $\r -> error_terminate(400, State); $\s -> parse_uri(Rest, State, SoFar); _ -> parse_method(Rest, State, << SoFar/binary, C >>) end. parse_uri(<< $\r, _/bits >>, State, _) -> error_terminate(400, State); parse_uri(<< "* ", Rest/bits >>, State, Method) -> parse_version(Rest, State, Method, <<"*">>, <<>>, <<>>); parse_uri(<< "http://", Rest/bits >>, State, Method) -> parse_uri_skip_host(Rest, State, Method); parse_uri(<< "https://", Rest/bits >>, State, Method) -> parse_uri_skip_host(Rest, State, Method); parse_uri(Buffer, State, Method) -> parse_uri_path(Buffer, State, Method, <<>>). parse_uri_skip_host(<< C, Rest/bits >>, State, Method) -> case C of $\r -> error_terminate(400, State); $/ -> parse_uri_path(Rest, State, Method, <<"/">>); _ -> parse_uri_skip_host(Rest, State, Method) end. parse_uri_path(<< C, Rest/bits >>, State, Method, SoFar) -> case C of $\r -> error_terminate(400, State); $\s -> parse_version(Rest, State, Method, SoFar, <<>>, <<>>); $? -> parse_uri_query(Rest, State, Method, SoFar, <<>>); $# -> parse_uri_fragment(Rest, State, Method, SoFar, <<>>, <<>>); _ -> parse_uri_path(Rest, State, Method, << SoFar/binary, C >>) end. parse_uri_query(<< C, Rest/bits >>, S, M, P, SoFar) -> case C of $\r -> error_terminate(400, S); $\s -> parse_version(Rest, S, M, P, SoFar, <<>>); $# -> parse_uri_fragment(Rest, S, M, P, SoFar, <<>>); _ -> parse_uri_query(Rest, S, M, P, << SoFar/binary, C >>) end. parse_uri_fragment(<< C, Rest/bits >>, S, M, P, Q, SoFar) -> case C of $\r -> error_terminate(400, S); $\s -> parse_version(Rest, S, M, P, Q, SoFar); _ -> parse_uri_fragment(Rest, S, M, P, Q, << SoFar/binary, C >>) end. parse_version(<< "HTTP/1.1\r\n", Rest/bits >>, S, M, P, Q, F) -> parse_header(Rest, S, M, P, Q, F, {1, 1}, []); parse_version(<< "HTTP/1.0\r\n", Rest/bits >>, S, M, P, Q, F) -> parse_header(Rest, S, M, P, Q, F, {1, 0}, []); parse_version(_, State, _, _, _, _) -> error_terminate(505, State). %% Stop receiving data if we have more than allowed number of headers. wait_header(_, State=#state{max_headers=MaxHeaders}, _, _, _, _, _, Headers) when length(Headers) >= MaxHeaders -> error_terminate(400, State); wait_header(Buffer, State=#state{socket=Socket, transport=Transport, timeout=Timeout}, M, P, Q, F, V, H) -> case Transport:recv(Socket, 0, Timeout) of {ok, Data} -> parse_header(<< Buffer/binary, Data/binary >>, State, M, P, Q, F, V, H); {error, timeout} -> error_terminate(408, State); {error, _} -> terminate(State) end. parse_header(<< $\r, $\n, Rest/bits >>, S, M, P, Q, F, V, Headers) -> request(Rest, S, M, P, Q, F, V, lists:reverse(Headers)); parse_header(Buffer, State=#state{max_header_name_length=MaxLength}, M, P, Q, F, V, H) -> case binary:match(Buffer, <<":">>) of nomatch when byte_size(Buffer) > MaxLength -> error_terminate(400, State); nomatch -> wait_header(Buffer, State, M, P, Q, F, V, H); {_, _} -> parse_hd_name(Buffer, State, M, P, Q, F, V, H, <<>>) end. %% I know, this isn't exactly pretty. But this is the most critical %% code path and as such needs to be optimized to death. %% %% ... Sorry for your eyes. %% %% But let's be honest, that's still pretty readable. parse_hd_name(<< C, Rest/bits >>, S, M, P, Q, F, V, H, SoFar) -> case C of $: -> parse_hd_before_value(Rest, S, M, P, Q, F, V, H, SoFar); $\s -> parse_hd_name_ws(Rest, S, M, P, Q, F, V, H, SoFar); $\t -> parse_hd_name_ws(Rest, S, M, P, Q, F, V, H, SoFar); $A -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $a >>); $B -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $b >>); $C -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $c >>); $D -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $d >>); $E -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $e >>); $F -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $f >>); $G -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $g >>); $H -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $h >>); $I -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $i >>); $J -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $j >>); $K -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $k >>); $L -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $l >>); $M -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $m >>); $N -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $n >>); $O -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $o >>); $P -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $p >>); $Q -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $q >>); $R -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $r >>); $S -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $s >>); $T -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $t >>); $U -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $u >>); $V -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $v >>); $W -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $w >>); $X -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $x >>); $Y -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $y >>); $Z -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, $z >>); C -> parse_hd_name(Rest, S, M, P, Q, F, V, H, << SoFar/binary, C >>) end. parse_hd_name_ws(<< C, Rest/bits >>, S, M, P, Q, F, V, H, Name) -> case C of $\s -> parse_hd_name_ws(Rest, S, M, P, Q, F, V, H, Name); $\t -> parse_hd_name_ws(Rest, S, M, P, Q, F, V, H, Name); $: -> parse_hd_before_value(Rest, S, M, P, Q, F, V, H, Name) end. wait_hd_before_value(Buffer, State=#state{ socket=Socket, transport=Transport, timeout=Timeout}, M, P, Q, F, V, H, N) -> case Transport:recv(Socket, 0, Timeout) of {ok, Data} -> parse_hd_before_value(<< Buffer/binary, Data/binary >>, State, M, P, Q, F, V, H, N); {error, timeout} -> error_terminate(408, State); {error, _} -> terminate(State) end. parse_hd_before_value(<< $\s, Rest/bits >>, S, M, P, Q, F, V, H, N) -> parse_hd_before_value(Rest, S, M, P, Q, F, V, H, N); parse_hd_before_value(<< $\t, Rest/bits >>, S, M, P, Q, F, V, H, N) -> parse_hd_before_value(Rest, S, M, P, Q, F, V, H, N); parse_hd_before_value(Buffer, State=#state{ max_header_value_length=MaxLength}, M, P, Q, F, V, H, N) -> case binary:match(Buffer, <<"\n">>) of nomatch when byte_size(Buffer) > MaxLength -> error_terminate(400, State); nomatch -> wait_hd_before_value(Buffer, State, M, P, Q, F, V, H, N); {_, _} -> parse_hd_value(Buffer, State, M, P, Q, F, V, H, N, <<>>) end. %% We completely ignore the first argument which is always %% the empty binary. We keep it there because we don't want %% to change the other arguments' position and trigger costy %% operations for no reasons. wait_hd_value(_, State=#state{ socket=Socket, transport=Transport, timeout=Timeout}, M, P, Q, F, V, H, N, SoFar) -> case Transport:recv(Socket, 0, Timeout) of {ok, Data} -> parse_hd_value(Data, State, M, P, Q, F, V, H, N, SoFar); {error, timeout} -> error_terminate(408, State); {error, _} -> terminate(State) end. %% Pushing back as much as we could the retrieval of new data %% to check for multilines allows us to avoid a few tests in %% the critical path, but forces us to have a special function. wait_hd_value_nl(_, State=#state{ socket=Socket, transport=Transport, timeout=Timeout}, M, P, Q, F, V, Headers, Name, SoFar) -> case Transport:recv(Socket, 0, Timeout) of {ok, << C, Data/bits >>} when C =:= $\s; C =:= $\t -> parse_hd_value(Data, State, M, P, Q, F, V, Headers, Name, SoFar); {ok, Data} -> parse_header(Data, State, M, P, Q, F, V, [{Name, SoFar}|Headers]); {error, timeout} -> error_terminate(408, State); {error, _} -> terminate(State) end. parse_hd_value(<< $\r, Rest/bits >>, S, M, P, Q, F, V, Headers, Name, SoFar) -> case Rest of << $\n >> -> wait_hd_value_nl(<<>>, S, M, P, Q, F, V, Headers, Name, SoFar); << $\n, C, Rest2/bits >> when C =:= $\s; C =:= $\t -> parse_hd_value(Rest2, S, M, P, Q, F, V, Headers, Name, SoFar); << $\n, Rest2/bits >> -> parse_header(Rest2, S, M, P, Q, F, V, [{Name, SoFar}|Headers]) end; parse_hd_value(<< C, Rest/bits >>, S, M, P, Q, F, V, H, N, SoFar) -> parse_hd_value(Rest, S, M, P, Q, F, V, H, N, << SoFar/binary, C >>); parse_hd_value(<<>>, State=#state{max_header_value_length=MaxLength}, _, _, _, _, _, _, _, SoFar) when byte_size(SoFar) > MaxLength -> error_terminate(400, State); parse_hd_value(<<>>, S, M, P, Q, F, V, H, N, SoFar) -> wait_hd_value(<<>>, S, M, P, Q, F, V, H, N, SoFar). request(B, State=#state{transport=Transport}, M, P, Q, F, Version, Headers) -> case lists:keyfind(<<"host">>, 1, Headers) of false when Version =:= {1, 1} -> error_terminate(400, State); false -> request(B, State, M, P, Q, F, Version, Headers, <<>>, default_port(Transport:name())); {_, RawHost} -> case parse_host(RawHost, <<>>) of {Host, undefined} -> request(B, State, M, P, Q, F, Version, Headers, Host, default_port(Transport:name())); {Host, Port} -> request(B, State, M, P, Q, F, Version, Headers, Host, Port) end end. -spec default_port(atom()) -> 80 | 443. default_port(ssl) -> 443; default_port(_) -> 80. %% Another hurtful block of code. :) parse_host(<<>>, Acc) -> {Acc, undefined}; parse_host(<< $:, Rest/bits >>, Acc) -> {Acc, list_to_integer(binary_to_list(Rest))}; parse_host(<< C, Rest/bits >>, Acc) -> case C of $A -> parse_host(Rest, << Acc/binary, $a >>); $B -> parse_host(Rest, << Acc/binary, $b >>); $C -> parse_host(Rest, << Acc/binary, $c >>); $D -> parse_host(Rest, << Acc/binary, $d >>); $E -> parse_host(Rest, << Acc/binary, $e >>); $F -> parse_host(Rest, << Acc/binary, $f >>); $G -> parse_host(Rest, << Acc/binary, $g >>); $H -> parse_host(Rest, << Acc/binary, $h >>); $I -> parse_host(Rest, << Acc/binary, $i >>); $J -> parse_host(Rest, << Acc/binary, $j >>); $K -> parse_host(Rest, << Acc/binary, $k >>); $L -> parse_host(Rest, << Acc/binary, $l >>); $M -> parse_host(Rest, << Acc/binary, $m >>); $N -> parse_host(Rest, << Acc/binary, $n >>); $O -> parse_host(Rest, << Acc/binary, $o >>); $P -> parse_host(Rest, << Acc/binary, $p >>); $Q -> parse_host(Rest, << Acc/binary, $q >>); $R -> parse_host(Rest, << Acc/binary, $r >>); $S -> parse_host(Rest, << Acc/binary, $s >>); $T -> parse_host(Rest, << Acc/binary, $t >>); $U -> parse_host(Rest, << Acc/binary, $u >>); $V -> parse_host(Rest, << Acc/binary, $v >>); $W -> parse_host(Rest, << Acc/binary, $w >>); $X -> parse_host(Rest, << Acc/binary, $x >>); $Y -> parse_host(Rest, << Acc/binary, $y >>); $Z -> parse_host(Rest, << Acc/binary, $z >>); _ -> parse_host(Rest, << Acc/binary, C >>) end. %% End of request parsing. %% %% We create the Req object and start handling the request. request(Buffer, State=#state{socket=Socket, transport=Transport, req_keepalive=ReqKeepalive, max_keepalive=MaxKeepalive, onresponse=OnResponse}, Method, Path, Query, Fragment, Version, Headers, Host, Port) -> Req = cowboy_req:new(Socket, Transport, Method, Path, Query, Fragment, Version, Headers, Host, Port, Buffer, ReqKeepalive < MaxKeepalive, OnResponse), onrequest(Req, State, Host). %% 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{}, binary()) -> ok. onrequest(Req, State=#state{onrequest=undefined}, Host) -> dispatch(Req, State, Host, cowboy_req:get(path, Req)); onrequest(Req, State=#state{onrequest=OnRequest}, Host) -> Req2 = OnRequest(Req), case cowboy_req:get(resp_state, Req2) of waiting -> dispatch(Req2, State, Host, cowboy_req:get(path, Req2)); _ -> next_request(Req2, State, ok) end. -spec dispatch(cowboy_req:req(), #state{}, binary(), binary()) -> ok. dispatch(Req, State=#state{dispatch=Dispatch}, Host, Path) -> case cowboy_dispatcher:match(Dispatch, Host, Path) of {ok, Handler, Opts, Bindings, HostInfo, PathInfo} -> Req2 = cowboy_req:set_bindings(HostInfo, PathInfo, Bindings, Req), handler_init(Req2, State, Handler, Opts); {error, notfound, host} -> error_terminate(400, State); {error, badrequest, path} -> error_terminate(400, State); {error, notfound, path} -> error_terminate(404, State) end. -spec handler_init(cowboy_req:req(), #state{}, module(), any()) -> ok. handler_init(Req, State=#state{transport=Transport}, Handler, Opts) -> try Handler:init({Transport:name(), http}, Req, Opts) of {ok, Req2, HandlerState} -> handler_handle(Req2, State, Handler, HandlerState); {loop, Req2, HandlerState} -> handler_before_loop(Req2, State#state{hibernate=false}, Handler, HandlerState); {loop, Req2, HandlerState, hibernate} -> handler_before_loop(Req2, State#state{hibernate=true}, Handler, HandlerState); {loop, Req2, HandlerState, Timeout} -> handler_before_loop(Req2, State#state{loop_timeout=Timeout}, Handler, HandlerState); {loop, Req2, HandlerState, Timeout, hibernate} -> handler_before_loop(Req2, State#state{ hibernate=true, loop_timeout=Timeout}, Handler, HandlerState); {shutdown, Req2, HandlerState} -> handler_terminate(Req2, Handler, HandlerState); %% @todo {upgrade, transport, Module} {upgrade, protocol, Module} -> upgrade_protocol(Req, State, Handler, Opts, Module); {upgrade, protocol, Module, Req2, Opts2} -> upgrade_protocol(Req2, State, Handler, Opts2, Module) catch Class:Reason -> error_terminate(500, State), error_logger:error_msg( "** Cowboy handler ~p terminating in ~p/~p~n" " for the reason ~p:~p~n" "** Options were ~p~n" "** Request was ~p~n" "** Stacktrace: ~p~n~n", [Handler, init, 3, Class, Reason, Opts, cowboy_req:to_list(Req), erlang:get_stacktrace()]) end. -spec upgrade_protocol(cowboy_req:req(), #state{}, module(), any(), module()) -> ok. upgrade_protocol(Req, State=#state{listener=ListenerPid}, 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(cowboy_req:req(), #state{}, module(), any()) -> ok. handler_handle(Req, State, Handler, HandlerState) -> try Handler:handle(Req, HandlerState) of {ok, Req2, HandlerState2} -> terminate_request(Req2, State, Handler, HandlerState2) catch Class:Reason -> error_logger:error_msg( "** Cowboy handler ~p terminating in ~p/~p~n" " for the reason ~p:~p~n" "** Handler state was ~p~n" "** Request was ~p~n" "** Stacktrace: ~p~n~n", [Handler, handle, 2, Class, Reason, HandlerState, cowboy_req:to_list(Req), erlang:get_stacktrace()]), handler_terminate(Req, Handler, HandlerState), 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(cowboy_req:req(), #state{}, module(), any()) -> ok. handler_before_loop(Req, State=#state{hibernate=true}, Handler, HandlerState) -> State2 = handler_loop_timeout(State), catch erlang:hibernate(?MODULE, handler_loop, [Req, State2#state{hibernate=false}, Handler, HandlerState]), ok; handler_before_loop(Req, State, Handler, HandlerState) -> State2 = handler_loop_timeout(State), handler_loop(Req, State2, Handler, HandlerState). %% 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}. %% @private -spec handler_loop(cowboy_req:req(), #state{}, module(), any()) -> ok. handler_loop(Req, State=#state{loop_timeout_ref=TRef}, Handler, HandlerState) -> receive {timeout, TRef, ?MODULE} -> terminate_request(Req, State, Handler, HandlerState); {timeout, OlderTRef, ?MODULE} when is_reference(OlderTRef) -> handler_loop(Req, State, Handler, HandlerState); Message -> handler_call(Req, State, Handler, HandlerState, Message) end. -spec handler_call(cowboy_req:req(), #state{}, module(), any(), any()) -> ok. handler_call(Req, State, Handler, HandlerState, Message) -> try Handler:info(Message, Req, HandlerState) of {ok, Req2, HandlerState2} -> terminate_request(Req2, State, Handler, HandlerState2); {loop, Req2, HandlerState2} -> handler_before_loop(Req2, State, Handler, HandlerState2); {loop, Req2, HandlerState2, hibernate} -> handler_before_loop(Req2, State#state{hibernate=true}, Handler, HandlerState2) catch Class:Reason -> error_logger:error_msg( "** Cowboy handler ~p terminating in ~p/~p~n" " for the reason ~p:~p~n" "** Handler state was ~p~n" "** Request was ~p~n" "** Stacktrace: ~p~n~n", [Handler, info, 3, Class, Reason, HandlerState, cowboy_req:to_list(Req), erlang:get_stacktrace()]), handler_terminate(Req, Handler, HandlerState), error_terminate(500, State) end. -spec handler_terminate(cowboy_req:req(), module(), any()) -> ok. handler_terminate(Req, Handler, HandlerState) -> try Handler:terminate(cowboy_req:lock(Req), HandlerState) catch Class:Reason -> error_logger:error_msg( "** Cowboy handler ~p terminating in ~p/~p~n" " for the reason ~p:~p~n" "** Handler state was ~p~n" "** Request was ~p~n" "** Stacktrace: ~p~n~n", [Handler, terminate, 2, Class, Reason, HandlerState, cowboy_req:to_list(Req), erlang:get_stacktrace()]) end. -spec terminate_request(cowboy_req:req(), #state{}, module(), any()) -> ok. terminate_request(Req, State, Handler, HandlerState) -> HandlerRes = handler_terminate(Req, Handler, HandlerState), 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, Connection]} = case cowboy_req:skip_body(Req) of {ok, Req2} -> {ok, cowboy_req:get([buffer, connection], Req2)}; {error, _} -> {close, [<<>>, close]} end, %% Flush the resp_sent message before moving on. receive {cowboy_req, resp_sent} -> ok after 0 -> ok end, case {HandlerRes, BodyRes, Connection} of {ok, ok, keepalive} -> ?MODULE:parse_request(Buffer, State#state{ req_keepalive=Keepalive + 1}, 0); _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, <<"GET">>, <<>>, <<>>, <<>>, {1, 1}, [], <<>>, undefined, <<>>, false, OnResponse)), ok end, terminate(State). -spec terminate(#state{}) -> ok. terminate(#state{socket=Socket, transport=Transport}) -> Transport:close(Socket), ok.