%% Copyright (c) 2015-2017, Loïc Hoguin %% %% 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. -module(cowboy_http2). -ifdef(OTP_RELEASE). -compile({nowarn_deprecated_function, [{erlang, get_stacktrace, 0}]}). -endif. -export([init/6]). -export([init/10]). -export([init/12]). -export([system_continue/3]). -export([system_terminate/4]). -export([system_code_change/4]). -type opts() :: #{ compress_buffering => boolean(), compress_threshold => non_neg_integer(), connection_type => worker | supervisor, connection_window_margin_size => 0..16#7fffffff, connection_window_update_threshold => 0..16#7fffffff, enable_connect_protocol => boolean(), env => cowboy_middleware:env(), idle_timeout => timeout(), inactivity_timeout => timeout(), initial_connection_window_size => 65535..16#7fffffff, initial_stream_window_size => 0..16#7fffffff, logger => module(), max_concurrent_streams => non_neg_integer() | infinity, max_connection_buffer_size => non_neg_integer(), max_connection_window_size => 0..16#7fffffff, max_decode_table_size => non_neg_integer(), max_encode_table_size => non_neg_integer(), max_frame_size_received => 16384..16777215, max_frame_size_sent => 16384..16777215 | infinity, max_received_frame_rate => {pos_integer(), timeout()}, max_reset_stream_rate => {pos_integer(), timeout()}, max_stream_buffer_size => non_neg_integer(), max_stream_window_size => 0..16#7fffffff, metrics_callback => cowboy_metrics_h:metrics_callback(), middlewares => [module()], preface_timeout => timeout(), proxy_header => boolean(), sendfile => boolean(), settings_timeout => timeout(), shutdown_timeout => timeout(), stream_handlers => [module()], stream_window_data_threshold => 0..16#7fffffff, stream_window_margin_size => 0..16#7fffffff, stream_window_update_threshold => 0..16#7fffffff, tracer_callback => cowboy_tracer_h:tracer_callback(), tracer_match_specs => cowboy_tracer_h:tracer_match_specs(), %% Open ended because configured stream handlers might add options. _ => _ }. -export_type([opts/0]). -record(stream, { %% Whether the stream is currently stopping. status = running :: running | stopping, %% Flow requested for this stream. flow = 0 :: non_neg_integer(), %% Stream state. state :: {module, any()} }). -record(state, { parent = undefined :: pid(), ref :: ranch:ref(), socket = undefined :: inet:socket(), transport :: module(), proxy_header :: undefined | ranch_proxy_header:proxy_info(), opts = #{} :: opts(), %% Timer for idle_timeout. timer = undefined :: undefined | reference(), %% Remote address and port for the connection. peer = undefined :: {inet:ip_address(), inet:port_number()}, %% Local address and port for the connection. sock = undefined :: {inet:ip_address(), inet:port_number()}, %% Client certificate (TLS only). cert :: undefined | binary(), %% HTTP/2 state machine. http2_status :: sequence | settings | upgrade | connected | closing, http2_machine :: cow_http2_machine:http2_machine(), %% HTTP/2 frame rate flood protection. frame_rate_num :: undefined | pos_integer(), frame_rate_time :: undefined | integer(), %% HTTP/2 reset stream flood protection. reset_rate_num :: undefined | pos_integer(), reset_rate_time :: undefined | integer(), %% Flow requested for all streams. flow = 0 :: non_neg_integer(), %% Currently active HTTP/2 streams. Streams may be initiated either %% by the client or by the server through PUSH_PROMISE frames. streams = #{} :: #{cow_http2:streamid() => #stream{}}, %% Streams can spawn zero or more children which are then managed %% by this module if operating as a supervisor. children = cowboy_children:init() :: cowboy_children:children() }). -spec init(pid(), ranch:ref(), inet:socket(), module(), ranch_proxy_header:proxy_info() | undefined, cowboy:opts()) -> ok. init(Parent, Ref, Socket, Transport, ProxyHeader, Opts) -> Peer0 = Transport:peername(Socket), Sock0 = Transport:sockname(Socket), Cert1 = case Transport:name() of ssl -> case ssl:peercert(Socket) of {error, no_peercert} -> {ok, undefined}; Cert0 -> Cert0 end; _ -> {ok, undefined} end, case {Peer0, Sock0, Cert1} of {{ok, Peer}, {ok, Sock}, {ok, Cert}} -> init(Parent, Ref, Socket, Transport, ProxyHeader, Opts, Peer, Sock, Cert, <<>>); {{error, Reason}, _, _} -> terminate(undefined, {socket_error, Reason, 'A socket error occurred when retrieving the peer name.'}); {_, {error, Reason}, _} -> terminate(undefined, {socket_error, Reason, 'A socket error occurred when retrieving the sock name.'}); {_, _, {error, Reason}} -> terminate(undefined, {socket_error, Reason, 'A socket error occurred when retrieving the client TLS certificate.'}) end. -spec init(pid(), ranch:ref(), inet:socket(), module(), ranch_proxy_header:proxy_info() | undefined, cowboy:opts(), {inet:ip_address(), inet:port_number()}, {inet:ip_address(), inet:port_number()}, binary() | undefined, binary()) -> ok. init(Parent, Ref, Socket, Transport, ProxyHeader, Opts, Peer, Sock, Cert, Buffer) -> {ok, Preface, HTTP2Machine} = cow_http2_machine:init(server, Opts), State = set_timeout(init_rate_limiting(#state{parent=Parent, ref=Ref, socket=Socket, transport=Transport, proxy_header=ProxyHeader, opts=Opts, peer=Peer, sock=Sock, cert=Cert, http2_status=sequence, http2_machine=HTTP2Machine})), Transport:send(Socket, Preface), case Buffer of <<>> -> loop(State, Buffer); _ -> parse(State, Buffer) end. init_rate_limiting(State=#state{opts=Opts}) -> {FrameRateNum, FrameRatePeriod} = maps:get(max_received_frame_rate, Opts, {1000, 10000}), {ResetRateNum, ResetRatePeriod} = maps:get(max_reset_stream_rate, Opts, {10, 10000}), CurrentTime = erlang:monotonic_time(millisecond), State#state{ frame_rate_num=FrameRateNum, frame_rate_time=add_period(CurrentTime, FrameRatePeriod), reset_rate_num=ResetRateNum, reset_rate_time=add_period(CurrentTime, ResetRatePeriod) }. add_period(_, infinity) -> infinity; add_period(Time, Period) -> Time + Period. %% @todo Add an argument for the request body. -spec init(pid(), ranch:ref(), inet:socket(), module(), ranch_proxy_header:proxy_info() | undefined, cowboy:opts(), {inet:ip_address(), inet:port_number()}, {inet:ip_address(), inet:port_number()}, binary() | undefined, binary(), map() | undefined, cowboy_req:req()) -> ok. init(Parent, Ref, Socket, Transport, ProxyHeader, Opts, Peer, Sock, Cert, Buffer, _Settings, Req=#{method := Method}) -> {ok, Preface, HTTP2Machine0} = cow_http2_machine:init(server, Opts), {ok, StreamID, HTTP2Machine} = cow_http2_machine:init_upgrade_stream(Method, HTTP2Machine0), State0 = #state{parent=Parent, ref=Ref, socket=Socket, transport=Transport, proxy_header=ProxyHeader, opts=Opts, peer=Peer, sock=Sock, cert=Cert, http2_status=upgrade, http2_machine=HTTP2Machine}, State1 = headers_frame(State0#state{ http2_machine=HTTP2Machine}, StreamID, Req), %% We assume that the upgrade will be applied. A stream handler %% must not prevent the normal operations of the server. State2 = info(State1, 1, {switch_protocol, #{ <<"connection">> => <<"Upgrade">>, <<"upgrade">> => <<"h2c">> }, ?MODULE, undefined}), %% @todo undefined or #{}? State = set_timeout(init_rate_limiting(State2#state{http2_status=sequence})), Transport:send(Socket, Preface), case Buffer of <<>> -> loop(State, Buffer); _ -> parse(State, Buffer) end. loop(State=#state{parent=Parent, socket=Socket, transport=Transport, opts=Opts, timer=TimerRef, children=Children}, Buffer) -> %% @todo This should only be called when data was read. Transport:setopts(Socket, [{active, once}]), Messages = Transport:messages(), InactivityTimeout = maps:get(inactivity_timeout, Opts, 300000), receive %% Socket messages. {OK, Socket, Data} when OK =:= element(1, Messages) -> parse(set_timeout(State), << Buffer/binary, Data/binary >>); {Closed, Socket} when Closed =:= element(2, Messages) -> terminate(State, {socket_error, closed, 'The socket has been closed.'}); {Error, Socket, Reason} when Error =:= element(3, Messages) -> terminate(State, {socket_error, Reason, 'An error has occurred on the socket.'}); %% System messages. {'EXIT', Parent, Reason} -> %% @todo Graceful shutdown here as well? terminate(State, {stop, {exit, Reason}, 'Parent process terminated.'}); {system, From, Request} -> sys:handle_system_msg(Request, From, Parent, ?MODULE, [], {State, Buffer}); %% Timeouts. {timeout, TimerRef, idle_timeout} -> terminate(State, {stop, timeout, 'Connection idle longer than configuration allows.'}); {timeout, Ref, {shutdown, Pid}} -> cowboy_children:shutdown_timeout(Children, Ref, Pid), loop(State, Buffer); {timeout, TRef, {cow_http2_machine, Name}} -> loop(timeout(State, Name, TRef), Buffer); %% Messages pertaining to a stream. {{Pid, StreamID}, Msg} when Pid =:= self() -> loop(info(State, StreamID, Msg), Buffer); %% Exit signal from children. Msg = {'EXIT', Pid, _} -> loop(down(State, Pid, Msg), Buffer); %% Calls from supervisor module. {'$gen_call', From, Call} -> cowboy_children:handle_supervisor_call(Call, From, Children, ?MODULE), loop(State, Buffer); Msg -> cowboy:log(warning, "Received stray message ~p.", [Msg], Opts), loop(State, Buffer) after InactivityTimeout -> terminate(State, {internal_error, timeout, 'No message or data received before timeout.'}) end. set_timeout(State=#state{opts=Opts, timer=TimerRef0}) -> ok = case TimerRef0 of undefined -> ok; _ -> erlang:cancel_timer(TimerRef0, [{async, true}, {info, false}]) end, TimerRef = case maps:get(idle_timeout, Opts, 60000) of infinity -> undefined; Timeout -> erlang:start_timer(Timeout, self(), idle_timeout) end, State#state{timer=TimerRef}. %% HTTP/2 protocol parsing. parse(State=#state{http2_status=sequence}, Data) -> case cow_http2:parse_sequence(Data) of {ok, Rest} -> parse(State#state{http2_status=settings}, Rest); more -> loop(State, Data); Error = {connection_error, _, _} -> terminate(State, Error) end; parse(State=#state{http2_status=Status, http2_machine=HTTP2Machine, streams=Streams}, Data) -> MaxFrameSize = cow_http2_machine:get_local_setting(max_frame_size, HTTP2Machine), case cow_http2:parse(Data, MaxFrameSize) of {ok, Frame, Rest} -> parse(frame_rate(State, Frame), Rest); {ignore, Rest} -> parse(frame_rate(State, ignore), Rest); {stream_error, StreamID, Reason, Human, Rest} -> parse(reset_stream(State, StreamID, {stream_error, Reason, Human}), Rest); Error = {connection_error, _, _} -> terminate(State, Error); %% Terminate the connection if we are closing and all streams have completed. more when Status =:= closing, Streams =:= #{} -> terminate(State, {stop, normal, 'The connection is going away.'}); more -> loop(State, Data) end. %% Frame rate flood protection. frame_rate(State0=#state{opts=Opts, frame_rate_num=Num0, frame_rate_time=Time}, Frame) -> {Result, State} = case Num0 - 1 of 0 -> CurrentTime = erlang:monotonic_time(millisecond), if CurrentTime < Time -> {error, State0}; true -> %% When the option has a period of infinity we cannot reach this clause. {Num, Period} = maps:get(max_received_frame_rate, Opts, {1000, 10000}), {ok, State0#state{frame_rate_num=Num, frame_rate_time=CurrentTime + Period}} end; Num -> {ok, State0#state{frame_rate_num=Num}} end, case {Result, Frame} of {ok, ignore} -> ignored_frame(State); {ok, _} -> frame(State, Frame); {error, _} -> terminate(State, {connection_error, enhance_your_calm, 'Frame rate larger than configuration allows. Flood? (CVE-2019-9512, CVE-2019-9515, CVE-2019-9518)'}) end. %% Frames received. %% We do nothing when receiving a lingering DATA frame. %% We already removed the stream flow from the connection %% flow and are therefore already accounting for the window %% being reduced by these frames. frame(State=#state{http2_machine=HTTP2Machine0}, Frame) -> case cow_http2_machine:frame(Frame, HTTP2Machine0) of {ok, HTTP2Machine} -> maybe_ack(State#state{http2_machine=HTTP2Machine}, Frame); {ok, {data, StreamID, IsFin, Data}, HTTP2Machine} -> data_frame(State#state{http2_machine=HTTP2Machine}, StreamID, IsFin, Data); {ok, {headers, StreamID, IsFin, Headers, PseudoHeaders, BodyLen}, HTTP2Machine} -> headers_frame(State#state{http2_machine=HTTP2Machine}, StreamID, IsFin, Headers, PseudoHeaders, BodyLen); {ok, {trailers, _StreamID, _Trailers}, HTTP2Machine} -> %% @todo Propagate trailers. State#state{http2_machine=HTTP2Machine}; {ok, {rst_stream, StreamID, Reason}, HTTP2Machine} -> rst_stream_frame(State#state{http2_machine=HTTP2Machine}, StreamID, Reason); {ok, GoAway={goaway, _, _, _}, HTTP2Machine} -> goaway(State#state{http2_machine=HTTP2Machine}, GoAway); {send, SendData, HTTP2Machine} -> %% We may need to send an alarm for each of the streams sending data. lists:foldl( fun({StreamID, _, _}, S) -> maybe_send_data_alarm(S, HTTP2Machine0, StreamID) end, send_data(maybe_ack(State#state{http2_machine=HTTP2Machine}, Frame), SendData), SendData); {error, {stream_error, StreamID, Reason, Human}, HTTP2Machine} -> reset_stream(State#state{http2_machine=HTTP2Machine}, StreamID, {stream_error, Reason, Human}); {error, Error={connection_error, _, _}, HTTP2Machine} -> terminate(State#state{http2_machine=HTTP2Machine}, Error) end. %% We use this opportunity to mark the HTTP/2 status as connected %% if we were still waiting for a SETTINGS frame. maybe_ack(State=#state{http2_status=settings}, Frame) -> maybe_ack(State#state{http2_status=connected}, Frame); maybe_ack(State=#state{socket=Socket, transport=Transport}, Frame) -> case Frame of {settings, _} -> Transport:send(Socket, cow_http2:settings_ack()); {ping, Opaque} -> Transport:send(Socket, cow_http2:ping_ack(Opaque)); _ -> ok end, State. data_frame(State0=#state{opts=Opts, flow=Flow, streams=Streams}, StreamID, IsFin, Data) -> case Streams of #{StreamID := Stream=#stream{status=running, flow=StreamFlow, state=StreamState0}} -> try cowboy_stream:data(StreamID, IsFin, Data, StreamState0) of {Commands, StreamState} -> %% Remove the amount of data received from the flow. %% We may receive more data than we requested. We ensure %% that the flow value doesn't go lower than 0. Size = byte_size(Data), State = update_window(State0#state{flow=max(0, Flow - Size), streams=Streams#{StreamID => Stream#stream{ flow=max(0, StreamFlow - Size), state=StreamState}}}, StreamID), commands(State, StreamID, Commands) catch Class:Exception -> cowboy:log(cowboy_stream:make_error_log(data, [StreamID, IsFin, Data, StreamState0], Class, Exception, erlang:get_stacktrace()), Opts), reset_stream(State0, StreamID, {internal_error, {Class, Exception}, 'Unhandled exception in cowboy_stream:data/4.'}) end; %% We ignore DATA frames for streams that are stopping. #{} -> State0 end. headers_frame(State, StreamID, IsFin, Headers, PseudoHeaders=#{method := <<"CONNECT">>}, _) when map_size(PseudoHeaders) =:= 2 -> early_error(State, StreamID, IsFin, Headers, PseudoHeaders, 501, 'The CONNECT method is currently not implemented. (RFC7231 4.3.6)'); headers_frame(State, StreamID, IsFin, Headers, PseudoHeaders=#{method := <<"TRACE">>}, _) -> early_error(State, StreamID, IsFin, Headers, PseudoHeaders, 501, 'The TRACE method is currently not implemented. (RFC7231 4.3.8)'); headers_frame(State, StreamID, IsFin, Headers, PseudoHeaders=#{authority := Authority}, BodyLen) -> headers_frame_parse_host(State, StreamID, IsFin, Headers, PseudoHeaders, BodyLen, Authority); headers_frame(State, StreamID, IsFin, Headers, PseudoHeaders, BodyLen) -> case lists:keyfind(<<"host">>, 1, Headers) of {_, Authority} -> headers_frame_parse_host(State, StreamID, IsFin, Headers, PseudoHeaders, BodyLen, Authority); _ -> reset_stream(State, StreamID, {stream_error, protocol_error, 'Requests translated from HTTP/1.1 must include a host header. (RFC7540 8.1.2.3, RFC7230 5.4)'}) end. headers_frame_parse_host(State=#state{ref=Ref, peer=Peer, sock=Sock, cert=Cert, proxy_header=ProxyHeader}, StreamID, IsFin, Headers, PseudoHeaders=#{method := Method, scheme := Scheme, path := PathWithQs}, BodyLen, Authority) -> try cow_http_hd:parse_host(Authority) of {Host, Port0} -> Port = ensure_port(Scheme, Port0), try cow_http:parse_fullpath(PathWithQs) of {<<>>, _} -> reset_stream(State, StreamID, {stream_error, protocol_error, 'The path component must not be empty. (RFC7540 8.1.2.3)'}); {Path, Qs} -> Req0 = #{ ref => Ref, pid => self(), streamid => StreamID, peer => Peer, sock => Sock, cert => Cert, method => Method, scheme => Scheme, host => Host, port => Port, path => Path, qs => Qs, version => 'HTTP/2', headers => headers_to_map(Headers, #{}), has_body => IsFin =:= nofin, body_length => BodyLen }, %% We add the PROXY header information if any. Req1 = case ProxyHeader of undefined -> Req0; _ -> Req0#{proxy_header => ProxyHeader} end, %% We add the protocol information for extended CONNECTs. Req = case PseudoHeaders of #{protocol := Protocol} -> Req1#{protocol => Protocol}; _ -> Req1 end, headers_frame(State, StreamID, Req) catch _:_ -> reset_stream(State, StreamID, {stream_error, protocol_error, 'The :path pseudo-header is invalid. (RFC7540 8.1.2.3)'}) end catch _:_ -> reset_stream(State, StreamID, {stream_error, protocol_error, 'The :authority pseudo-header is invalid. (RFC7540 8.1.2.3)'}) end. ensure_port(<<"http">>, undefined) -> 80; ensure_port(<<"https">>, undefined) -> 443; ensure_port(_, Port) -> Port. %% This function is necessary to properly handle duplicate headers %% and the special-case cookie header. headers_to_map([], Acc) -> Acc; headers_to_map([{Name, Value}|Tail], Acc0) -> Acc = case Acc0 of %% The cookie header does not use proper HTTP header lists. #{Name := Value0} when Name =:= <<"cookie">> -> Acc0#{Name => << Value0/binary, "; ", Value/binary >>}; #{Name := Value0} -> Acc0#{Name => << Value0/binary, ", ", Value/binary >>}; _ -> Acc0#{Name => Value} end, headers_to_map(Tail, Acc). headers_frame(State=#state{opts=Opts, streams=Streams}, StreamID, Req) -> try cowboy_stream:init(StreamID, Req, Opts) of {Commands, StreamState} -> commands(State#state{ streams=Streams#{StreamID => #stream{state=StreamState}}}, StreamID, Commands) catch Class:Exception -> cowboy:log(cowboy_stream:make_error_log(init, [StreamID, Req, Opts], Class, Exception, erlang:get_stacktrace()), Opts), reset_stream(State, StreamID, {internal_error, {Class, Exception}, 'Unhandled exception in cowboy_stream:init/3.'}) end. early_error(State0=#state{ref=Ref, opts=Opts, peer=Peer}, StreamID, _IsFin, _Headers, #{method := Method}, StatusCode0, HumanReadable) -> %% We automatically terminate the stream but it is not an error %% per se (at least not in the first implementation). Reason = {stream_error, no_error, HumanReadable}, %% The partial Req is minimal for now. We only have one case %% where it can be called (when a method is completely disabled). %% @todo Fill in the other elements. PartialReq = #{ ref => Ref, peer => Peer, method => Method }, Resp = {response, StatusCode0, RespHeaders0=#{<<"content-length">> => <<"0">>}, <<>>}, try cowboy_stream:early_error(StreamID, Reason, PartialReq, Resp, Opts) of {response, StatusCode, RespHeaders, RespBody} -> send_response(State0, StreamID, StatusCode, RespHeaders, RespBody) catch Class:Exception -> cowboy:log(cowboy_stream:make_error_log(early_error, [StreamID, Reason, PartialReq, Resp, Opts], Class, Exception, erlang:get_stacktrace()), Opts), %% We still need to send an error response, so send what we initially %% wanted to send. It's better than nothing. send_headers(State0, StreamID, fin, StatusCode0, RespHeaders0) end. rst_stream_frame(State=#state{streams=Streams0, children=Children0}, StreamID, Reason) -> case maps:take(StreamID, Streams0) of {#stream{state=StreamState}, Streams} -> terminate_stream_handler(State, StreamID, Reason, StreamState), Children = cowboy_children:shutdown(Children0, StreamID), State#state{streams=Streams, children=Children}; error -> State end. ignored_frame(State=#state{http2_machine=HTTP2Machine0}) -> case cow_http2_machine:ignored_frame(HTTP2Machine0) of {ok, HTTP2Machine} -> State#state{http2_machine=HTTP2Machine}; {error, Error={connection_error, _, _}, HTTP2Machine} -> terminate(State#state{http2_machine=HTTP2Machine}, Error) end. %% HTTP/2 timeouts. timeout(State=#state{http2_machine=HTTP2Machine0}, Name, TRef) -> case cow_http2_machine:timeout(Name, TRef, HTTP2Machine0) of {ok, HTTP2Machine} -> State#state{http2_machine=HTTP2Machine}; {error, Error={connection_error, _, _}, HTTP2Machine} -> terminate(State#state{http2_machine=HTTP2Machine}, Error) end. %% Erlang messages. down(State=#state{opts=Opts, children=Children0}, Pid, Msg) -> case cowboy_children:down(Children0, Pid) of %% The stream was terminated already. {ok, undefined, Children} -> State#state{children=Children}; %% The stream is still running. {ok, StreamID, Children} -> info(State#state{children=Children}, StreamID, Msg); %% The process was unknown. error -> cowboy:log(warning, "Received EXIT signal ~p for unknown process ~p.~n", [Msg, Pid], Opts), State end. info(State=#state{opts=Opts, streams=Streams}, StreamID, Msg) -> case Streams of #{StreamID := Stream=#stream{state=StreamState0}} -> try cowboy_stream:info(StreamID, Msg, StreamState0) of {Commands, StreamState} -> commands(State#state{streams=Streams#{StreamID => Stream#stream{state=StreamState}}}, StreamID, Commands) catch Class:Exception -> cowboy:log(cowboy_stream:make_error_log(info, [StreamID, Msg, StreamState0], Class, Exception, erlang:get_stacktrace()), Opts), reset_stream(State, StreamID, {internal_error, {Class, Exception}, 'Unhandled exception in cowboy_stream:info/3.'}) end; _ -> cowboy:log(warning, "Received message ~p for unknown or terminated stream ~p.", [Msg, StreamID], Opts), State end. %% Stream handler commands. %% %% @todo Kill the stream if it tries to send a response, headers, %% data or push promise when the stream is closed or half-closed. commands(State, _, []) -> State; %% Error responses are sent only if a response wasn't sent already. commands(State=#state{http2_machine=HTTP2Machine}, StreamID, [{error_response, StatusCode, Headers, Body}|Tail]) -> case cow_http2_machine:get_stream_local_state(StreamID, HTTP2Machine) of {ok, idle, _} -> commands(State, StreamID, [{response, StatusCode, Headers, Body}|Tail]); _ -> commands(State, StreamID, Tail) end; %% Send an informational response. commands(State0, StreamID, [{inform, StatusCode, Headers}|Tail]) -> State = send_headers(State0, StreamID, idle, StatusCode, Headers), commands(State, StreamID, Tail); %% Send response headers. commands(State0, StreamID, [{response, StatusCode, Headers, Body}|Tail]) -> State = send_response(State0, StreamID, StatusCode, Headers, Body), commands(State, StreamID, Tail); %% Send response headers. commands(State0, StreamID, [{headers, StatusCode, Headers}|Tail]) -> State = send_headers(State0, StreamID, nofin, StatusCode, Headers), commands(State, StreamID, Tail); %% Send a response body chunk. commands(State0, StreamID, [{data, IsFin, Data}|Tail]) -> State = maybe_send_data(State0, StreamID, IsFin, Data), commands(State, StreamID, Tail); %% Send trailers. commands(State0, StreamID, [{trailers, Trailers}|Tail]) -> State = maybe_send_data(State0, StreamID, fin, {trailers, maps:to_list(Trailers)}), commands(State, StreamID, Tail); %% Send a push promise. %% %% @todo Responses sent as a result of a push_promise request %% must not send push_promise frames themselves. %% %% @todo We should not send push_promise frames when we are %% in the closing http2_status. commands(State0=#state{socket=Socket, transport=Transport, http2_machine=HTTP2Machine0}, StreamID, [{push, Method, Scheme, Host, Port, Path, Qs, Headers0}|Tail]) -> Authority = case {Scheme, Port} of {<<"http">>, 80} -> Host; {<<"https">>, 443} -> Host; _ -> iolist_to_binary([Host, $:, integer_to_binary(Port)]) end, PathWithQs = iolist_to_binary(case Qs of <<>> -> Path; _ -> [Path, $?, Qs] end), PseudoHeaders = #{ method => Method, scheme => Scheme, authority => Authority, path => PathWithQs }, %% We need to make sure the header value is binary before we can %% create the Req object, as it expects them to be flat. Headers = maps:to_list(maps:map(fun(_, V) -> iolist_to_binary(V) end, Headers0)), State = case cow_http2_machine:prepare_push_promise(StreamID, HTTP2Machine0, PseudoHeaders, Headers) of {ok, PromisedStreamID, HeaderBlock, HTTP2Machine} -> Transport:send(Socket, cow_http2:push_promise( StreamID, PromisedStreamID, HeaderBlock)), headers_frame(State0#state{http2_machine=HTTP2Machine}, PromisedStreamID, fin, Headers, PseudoHeaders, 0); {error, no_push} -> State0 end, commands(State, StreamID, Tail); %% Read the request body. commands(State0=#state{flow=Flow, streams=Streams}, StreamID, [{flow, Size}|Tail]) -> #{StreamID := Stream=#stream{flow=StreamFlow}} = Streams, State = update_window(State0#state{flow=Flow + Size, streams=Streams#{StreamID => Stream#stream{flow=StreamFlow + Size}}}, StreamID), commands(State, StreamID, Tail); %% Supervise a child process. commands(State=#state{children=Children}, StreamID, [{spawn, Pid, Shutdown}|Tail]) -> commands(State#state{children=cowboy_children:up(Children, Pid, StreamID, Shutdown)}, StreamID, Tail); %% Error handling. commands(State, StreamID, [Error = {internal_error, _, _}|_Tail]) -> %% @todo Do we want to run the commands after an internal_error? %% @todo Do we even allow commands after? %% @todo Only reset when the stream still exists. reset_stream(State, StreamID, Error); %% Upgrade to HTTP/2. This is triggered by cowboy_http2 itself. commands(State=#state{socket=Socket, transport=Transport, http2_status=upgrade}, StreamID, [{switch_protocol, Headers, ?MODULE, _}|Tail]) -> %% @todo This 101 response needs to be passed through stream handlers. Transport:send(Socket, cow_http:response(101, 'HTTP/1.1', maps:to_list(Headers))), commands(State, StreamID, Tail); %% Use a different protocol within the stream (CONNECT :protocol). %% @todo Make sure we error out when the feature is disabled. commands(State0, StreamID, [{switch_protocol, Headers, _Mod, _ModState}|Tail]) -> State = info(State0, StreamID, {headers, 200, Headers}), commands(State, StreamID, Tail); %% Set options dynamically. commands(State, StreamID, [{set_options, _Opts}|Tail]) -> commands(State, StreamID, Tail); commands(State, StreamID, [stop|_Tail]) -> %% @todo Do we want to run the commands after a stop? %% @todo Do we even allow commands after? stop_stream(State, StreamID); %% Log event. commands(State=#state{opts=Opts}, StreamID, [Log={log, _, _, _}|Tail]) -> cowboy:log(Log, Opts), commands(State, StreamID, Tail). %% Tentatively update the window after the flow was updated. update_window(State=#state{socket=Socket, transport=Transport, http2_machine=HTTP2Machine0, flow=Flow, streams=Streams}, StreamID) -> #{StreamID := #stream{flow=StreamFlow}} = Streams, {Data1, HTTP2Machine2} = case cow_http2_machine:ensure_window(Flow, HTTP2Machine0) of ok -> {<<>>, HTTP2Machine0}; {ok, Increment1, HTTP2Machine1} -> {cow_http2:window_update(Increment1), HTTP2Machine1} end, {Data2, HTTP2Machine} = case cow_http2_machine:ensure_window(StreamID, StreamFlow, HTTP2Machine2) of ok -> {<<>>, HTTP2Machine2}; {ok, Increment2, HTTP2Machine3} -> {cow_http2:window_update(StreamID, Increment2), HTTP2Machine3} end, case {Data1, Data2} of {<<>>, <<>>} -> ok; _ -> Transport:send(Socket, [Data1, Data2]) end, State#state{http2_machine=HTTP2Machine}. %% Send the response, trailers or data. send_response(State0, StreamID, StatusCode, Headers, Body) -> Size = case Body of {sendfile, _, Bytes, _} -> Bytes; _ -> iolist_size(Body) end, case Size of 0 -> State = send_headers(State0, StreamID, fin, StatusCode, Headers), maybe_terminate_stream(State, StreamID, fin); _ -> State = send_headers(State0, StreamID, nofin, StatusCode, Headers), maybe_send_data(State, StreamID, fin, Body) end. send_headers(State=#state{socket=Socket, transport=Transport, http2_machine=HTTP2Machine0}, StreamID, IsFin0, StatusCode, Headers) -> {ok, IsFin, HeaderBlock, HTTP2Machine} = cow_http2_machine:prepare_headers(StreamID, HTTP2Machine0, IsFin0, #{status => cow_http:status_to_integer(StatusCode)}, headers_to_list(Headers)), Transport:send(Socket, cow_http2:headers(StreamID, IsFin, HeaderBlock)), State#state{http2_machine=HTTP2Machine}. %% The set-cookie header is special; we can only send one cookie per header. headers_to_list(Headers0=#{<<"set-cookie">> := SetCookies}) -> Headers = maps:to_list(maps:remove(<<"set-cookie">>, Headers0)), Headers ++ [{<<"set-cookie">>, Value} || Value <- SetCookies]; headers_to_list(Headers) -> maps:to_list(Headers). maybe_send_data(State0=#state{http2_machine=HTTP2Machine0}, StreamID, IsFin, Data0) -> Data = case is_tuple(Data0) of false -> {data, Data0}; true -> Data0 end, case cow_http2_machine:send_or_queue_data(StreamID, HTTP2Machine0, IsFin, Data) of {ok, HTTP2Machine} -> maybe_send_data_alarm(State0#state{http2_machine=HTTP2Machine}, HTTP2Machine0, StreamID); {send, SendData, HTTP2Machine} -> State = #state{http2_status=Status, streams=Streams} = send_data(State0#state{http2_machine=HTTP2Machine}, SendData), %% Terminate the connection if we are closing and all streams have completed. if Status =:= closing, Streams =:= #{} -> terminate(State, {stop, normal, 'The connection is going away.'}); true -> maybe_send_data_alarm(State, HTTP2Machine0, StreamID) end end. send_data(State, []) -> State; send_data(State0, [{StreamID, IsFin, SendData}|Tail]) -> State = send_data(State0, StreamID, IsFin, SendData), send_data(State, Tail). send_data(State0, StreamID, IsFin, [Data]) -> State = send_data_frame(State0, StreamID, IsFin, Data), maybe_terminate_stream(State, StreamID, IsFin); send_data(State0, StreamID, IsFin, [Data|Tail]) -> State = send_data_frame(State0, StreamID, nofin, Data), send_data(State, StreamID, IsFin, Tail). send_data_frame(State=#state{socket=Socket, transport=Transport}, StreamID, IsFin, {data, Data}) -> Transport:send(Socket, cow_http2:data(StreamID, IsFin, Data)), State; send_data_frame(State=#state{socket=Socket, transport=Transport, opts=Opts}, StreamID, IsFin, {sendfile, Offset, Bytes, Path}) -> Transport:send(Socket, cow_http2:data_header(StreamID, IsFin, Bytes)), %% When sendfile is disabled we explicitly use the fallback. _ = case maps:get(sendfile, Opts, true) of true -> Transport:sendfile(Socket, Path, Offset, Bytes); false -> ranch_transport:sendfile(Transport, Socket, Path, Offset, Bytes, []) end, State; %% The stream is terminated in cow_http2_machine:prepare_trailers. send_data_frame(State=#state{socket=Socket, transport=Transport, http2_machine=HTTP2Machine0}, StreamID, nofin, {trailers, Trailers}) -> {ok, HeaderBlock, HTTP2Machine} = cow_http2_machine:prepare_trailers(StreamID, HTTP2Machine0, Trailers), Transport:send(Socket, cow_http2:headers(StreamID, fin, HeaderBlock)), State#state{http2_machine=HTTP2Machine}. %% After we have sent or queued data we may need to set or clear an alarm. %% We do this by comparing the HTTP2Machine buffer state before/after for %% the relevant streams. maybe_send_data_alarm(State=#state{opts=Opts, http2_machine=HTTP2Machine}, HTTP2Machine0, StreamID) -> ConnBufferSizeBefore = cow_http2_machine:get_connection_local_buffer_size(HTTP2Machine0), ConnBufferSizeAfter = cow_http2_machine:get_connection_local_buffer_size(HTTP2Machine), {ok, StreamBufferSizeBefore} = cow_http2_machine:get_stream_local_buffer_size(StreamID, HTTP2Machine0), %% When the stream ends up closed after it finished sending data, %% we do not want to trigger an alarm. We act as if the buffer %% size did not change. StreamBufferSizeAfter = case cow_http2_machine:get_stream_local_buffer_size(StreamID, HTTP2Machine) of {ok, BSA} -> BSA; {error, closed} -> StreamBufferSizeBefore end, MaxConnBufferSize = maps:get(max_connection_buffer_size, Opts, 16000000), MaxStreamBufferSize = maps:get(max_stream_buffer_size, Opts, 8000000), %% I do not want to document these internal events yet. I am not yet %% convinced it should be {alarm, Name, on|off} and not {internal_event, E} %% or something else entirely. Though alarms are probably right. if ConnBufferSizeBefore >= MaxConnBufferSize, ConnBufferSizeAfter < MaxConnBufferSize -> connection_alarm(State, connection_buffer_full, off); ConnBufferSizeBefore < MaxConnBufferSize, ConnBufferSizeAfter >= MaxConnBufferSize -> connection_alarm(State, connection_buffer_full, on); StreamBufferSizeBefore >= MaxStreamBufferSize, StreamBufferSizeAfter < MaxStreamBufferSize -> stream_alarm(State, StreamID, stream_buffer_full, off); StreamBufferSizeBefore < MaxStreamBufferSize, StreamBufferSizeAfter >= MaxStreamBufferSize -> stream_alarm(State, StreamID, stream_buffer_full, on); true -> State end. connection_alarm(State0=#state{streams=Streams}, Name, Value) -> lists:foldl(fun(StreamID, State) -> stream_alarm(State, StreamID, Name, Value) end, State0, maps:keys(Streams)). stream_alarm(State, StreamID, Name, Value) -> info(State, StreamID, {alarm, Name, Value}). %% Terminate a stream or the connection. %% We may have to cancel streams even if we receive multiple %% GOAWAY frames as the LastStreamID value may be lower than %% the one previously received. goaway(State0=#state{socket=Socket, transport=Transport, http2_machine=HTTP2Machine, http2_status=Status, streams=Streams0}, {goaway, LastStreamID, Reason, _}) when Status =:= connected; Status =:= closing -> Streams = goaway_streams(State0, maps:to_list(Streams0), LastStreamID, {stop, {goaway, Reason}, 'The connection is going away.'}, []), State = State0#state{streams=maps:from_list(Streams)}, case Status of connected -> Transport:send(Socket, cow_http2:goaway( cow_http2_machine:get_last_streamid(HTTP2Machine), no_error, <<>>)), State#state{http2_status=closing}; _ -> State end; %% We terminate the connection immediately if it hasn't fully been initialized. goaway(State, {goaway, _, Reason, _}) -> terminate(State, {stop, {goaway, Reason}, 'The connection is going away.'}). %% Cancel client-initiated streams that are above LastStreamID. goaway_streams(_, [], _, _, Acc) -> Acc; goaway_streams(State, [{StreamID, #stream{state=StreamState}}|Tail], LastStreamID, Reason, Acc) when StreamID > LastStreamID, (StreamID rem 2) =:= 0 -> terminate_stream_handler(State, StreamID, Reason, StreamState), goaway_streams(State, Tail, LastStreamID, Reason, Acc); goaway_streams(State, [Stream|Tail], LastStreamID, Reason, Acc) -> goaway_streams(State, Tail, LastStreamID, Reason, [Stream|Acc]). -spec terminate(#state{}, _) -> no_return(). terminate(undefined, Reason) -> exit({shutdown, Reason}); terminate(State=#state{socket=Socket, transport=Transport, http2_status=Status, http2_machine=HTTP2Machine, streams=Streams, children=Children}, Reason) when Status =:= connected; Status =:= closing -> %% @todo We might want to optionally send the Reason value %% as debug data in the GOAWAY frame here. Perhaps more. case Status of connected -> Transport:send(Socket, cow_http2:goaway( cow_http2_machine:get_last_streamid(HTTP2Machine), terminate_reason(Reason), <<>>)); %% We already sent the GOAWAY frame. closing -> ok end, terminate_all_streams(State, maps:to_list(Streams), Reason), cowboy_children:terminate(Children), Transport:close(Socket), exit({shutdown, Reason}); terminate(#state{socket=Socket, transport=Transport}, Reason) -> Transport:close(Socket), exit({shutdown, Reason}). terminate_reason({connection_error, Reason, _}) -> Reason; terminate_reason({stop, _, _}) -> no_error; terminate_reason({socket_error, _, _}) -> internal_error; terminate_reason({internal_error, _, _}) -> internal_error. terminate_all_streams(_, [], _) -> ok; terminate_all_streams(State, [{StreamID, #stream{state=StreamState}}|Tail], Reason) -> terminate_stream_handler(State, StreamID, Reason, StreamState), terminate_all_streams(State, Tail, Reason). %% @todo Don't send an RST_STREAM if one was already sent. reset_stream(State0=#state{socket=Socket, transport=Transport, http2_machine=HTTP2Machine0}, StreamID, Error) -> Reason = case Error of {internal_error, _, _} -> internal_error; {stream_error, Reason0, _} -> Reason0 end, Transport:send(Socket, cow_http2:rst_stream(StreamID, Reason)), State1 = case cow_http2_machine:reset_stream(StreamID, HTTP2Machine0) of {ok, HTTP2Machine} -> terminate_stream(State0#state{http2_machine=HTTP2Machine}, StreamID, Error); {error, not_found} -> terminate_stream(State0, StreamID, Error) end, case reset_rate(State1) of {ok, State} -> State; error -> terminate(State1, {connection_error, enhance_your_calm, 'Stream reset rate larger than configuration allows. Flood? (CVE-2019-9514)'}) end. reset_rate(State0=#state{opts=Opts, reset_rate_num=Num0, reset_rate_time=Time}) -> case Num0 - 1 of 0 -> CurrentTime = erlang:monotonic_time(millisecond), if CurrentTime < Time -> error; true -> %% When the option has a period of infinity we cannot reach this clause. {Num, Period} = maps:get(max_reset_stream_rate, Opts, {10, 10000}), {ok, State0#state{reset_rate_num=Num, reset_rate_time=CurrentTime + Period}} end; Num -> {ok, State0#state{reset_rate_num=Num}} end. stop_stream(State=#state{http2_machine=HTTP2Machine}, StreamID) -> case cow_http2_machine:get_stream_local_state(StreamID, HTTP2Machine) of %% When the stream terminates normally (without sending RST_STREAM) %% and no response was sent, we need to send a proper response back to the client. %% We delay the termination of the stream until the response is fully sent. {ok, idle, _} -> info(stopping(State, StreamID), StreamID, {response, 204, #{}, <<>>}); %% When a response was sent but not terminated, we need to close the stream. %% We delay the termination of the stream until the response is fully sent. {ok, nofin, fin} -> stopping(State, StreamID); %% We only send a final DATA frame if there isn't one queued yet. {ok, nofin, _} -> info(stopping(State, StreamID), StreamID, {data, fin, <<>>}); %% When a response was sent fully we can terminate the stream, %% regardless of the stream being in half-closed or closed state. _ -> terminate_stream(State, StreamID) end. stopping(State=#state{streams=Streams}, StreamID) -> #{StreamID := Stream} = Streams, State#state{streams=Streams#{StreamID => Stream#stream{status=stopping}}}. %% If we finished sending data and the stream is stopping, terminate it. maybe_terminate_stream(State=#state{streams=Streams}, StreamID, fin) -> case Streams of #{StreamID := #stream{status=stopping}} -> terminate_stream(State, StreamID); _ -> State end; maybe_terminate_stream(State, _, _) -> State. %% When the stream stops normally without reading the request %% body fully we need to tell the client to stop sending it. %% We do this by sending an RST_STREAM with reason NO_ERROR. (RFC7540 8.1.0) terminate_stream(State0=#state{socket=Socket, transport=Transport, http2_machine=HTTP2Machine0}, StreamID) -> State = case cow_http2_machine:get_stream_local_state(StreamID, HTTP2Machine0) of {ok, fin, _} -> Transport:send(Socket, cow_http2:rst_stream(StreamID, no_error)), {ok, HTTP2Machine} = cow_http2_machine:reset_stream(StreamID, HTTP2Machine0), State0#state{http2_machine=HTTP2Machine}; {error, closed} -> State0 end, terminate_stream(State, StreamID, normal). %% We remove the stream flow from the connection flow. Any further %% data received for this stream is therefore fully contained within %% the extra window we allocated for this stream. terminate_stream(State=#state{flow=Flow, streams=Streams0, children=Children0}, StreamID, Reason) -> case maps:take(StreamID, Streams0) of {#stream{flow=StreamFlow, state=StreamState}, Streams} -> terminate_stream_handler(State, StreamID, Reason, StreamState), Children = cowboy_children:shutdown(Children0, StreamID), State#state{flow=Flow - StreamFlow, streams=Streams, children=Children}; error -> State end. terminate_stream_handler(#state{opts=Opts}, StreamID, Reason, StreamState) -> try cowboy_stream:terminate(StreamID, Reason, StreamState) catch Class:Exception -> cowboy:log(cowboy_stream:make_error_log(terminate, [StreamID, Reason, StreamState], Class, Exception, erlang:get_stacktrace()), Opts) end. %% System callbacks. -spec system_continue(_, _, {#state{}, binary()}) -> ok. system_continue(_, _, {State, Buffer}) -> loop(State, Buffer). -spec system_terminate(any(), _, _, {#state{}, binary()}) -> no_return(). system_terminate(Reason, _, _, {State, _}) -> %% @todo Graceful shutdown here as well? terminate(State, {stop, {exit, Reason}, 'sys:terminate/2,3 was called.'}). -spec system_code_change(Misc, _, _, _) -> {ok, Misc} when Misc::{#state{}, binary()}. system_code_change(Misc, _, _, _) -> {ok, Misc}.