%% Copyright (c) 2016-2019, Loïc Hoguin <[email protected]>
%%
%% 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(gun_http2).
-export([check_options/1]).
-export([name/0]).
-export([init/4]).
-export([handle/2]).
-export([close/2]).
-export([keepalive/1]).
-export([headers/8]).
-export([request/9]).
-export([data/5]).
-export([cancel/3]).
-export([down/1]).
-record(stream, {
id = undefined :: cow_http2:streamid(),
%% Reference used by the user of Gun to refer to this stream.
ref :: reference(),
%% Process to send messages to.
reply_to :: pid(),
%% Content handlers state.
handler_state :: undefined | gun_content_handler:state()
}).
-record(http2_state, {
owner :: pid(),
socket :: inet:socket() | ssl:sslsocket(),
transport :: module(),
opts = #{} :: map(), %% @todo
content_handlers :: gun_content_handler:opt(),
buffer = <<>> :: binary(),
%% HTTP/2 state machine.
http2_machine :: cow_http2_machine:http2_machine(),
%% Currently active HTTP/2 streams. Streams may be initiated either
%% by the client or by the server through PUSH_PROMISE frames.
streams = [] :: [#stream{}]
}).
check_options(Opts) ->
do_check_options(maps:to_list(Opts)).
do_check_options([]) ->
ok;
do_check_options([Opt={content_handlers, Handlers}|Opts]) ->
case gun_content_handler:check_option(Handlers) of
ok -> do_check_options(Opts);
error -> {error, {options, {http, Opt}}}
end;
do_check_options([{keepalive, infinity}|Opts]) ->
do_check_options(Opts);
do_check_options([{keepalive, K}|Opts]) when is_integer(K), K > 0 ->
do_check_options(Opts);
do_check_options([Opt|_]) ->
{error, {options, {http2, Opt}}}.
name() -> http2.
init(Owner, Socket, Transport, Opts) ->
{ok, Preface, HTTP2Machine} = cow_http2_machine:init(client, Opts),
Handlers = maps:get(content_handlers, Opts, [gun_data_h]),
%% @todo Better validate the preface being received.
State = #http2_state{owner=Owner, socket=Socket,
transport=Transport, opts=Opts, content_handlers=Handlers,
http2_machine=HTTP2Machine},
Transport:send(Socket, Preface),
State.
handle(Data, State=#http2_state{buffer=Buffer}) ->
parse(<< Buffer/binary, Data/binary >>, State#http2_state{buffer= <<>>}).
parse(Data, State0=#http2_state{http2_machine=HTTP2Machine}) ->
MaxFrameSize = cow_http2_machine:get_local_setting(max_frame_size, HTTP2Machine),
case cow_http2:parse(Data, MaxFrameSize) of
{ok, Frame, Rest} ->
case frame(State0, Frame) of
close -> close;
State -> parse(Rest, State)
end;
{ignore, Rest} ->
case ignored_frame(State0) of
close -> close;
State -> parse(Rest, State)
end;
{stream_error, StreamID, Reason, Human, Rest} ->
parse(Rest, reset_stream(State0, StreamID, {stream_error, Reason, Human}));
Error = {connection_error, _, _} ->
terminate(State0, Error);
more ->
{state, State0#http2_state{buffer=Data}}
end.
%% Frames received.
frame(State=#http2_state{http2_machine=HTTP2Machine0}, Frame) ->
case cow_http2_machine:frame(Frame, HTTP2Machine0) of
{ok, HTTP2Machine} ->
maybe_ack(State#http2_state{http2_machine=HTTP2Machine}, Frame);
{ok, {data, StreamID, IsFin, Data}, HTTP2Machine} ->
data_frame(State#http2_state{http2_machine=HTTP2Machine}, StreamID, IsFin, Data);
{ok, {headers, StreamID, IsFin, Headers, PseudoHeaders, BodyLen}, HTTP2Machine} ->
headers_frame(State#http2_state{http2_machine=HTTP2Machine},
StreamID, IsFin, Headers, PseudoHeaders, BodyLen);
{ok, {trailers, StreamID, Trailers}, HTTP2Machine} ->
trailers_frame(State#http2_state{http2_machine=HTTP2Machine},
StreamID, Trailers);
{ok, {rst_stream, StreamID, Reason}, HTTP2Machine} ->
rst_stream_frame(State#http2_state{http2_machine=HTTP2Machine}, StreamID, Reason);
{ok, {push_promise, StreamID, PromisedStreamID, Headers, PseudoHeaders}, HTTP2Machine} ->
push_promise_frame(State#http2_state{http2_machine=HTTP2Machine},
StreamID, PromisedStreamID, Headers, PseudoHeaders);
{ok, Frame={goaway, _StreamID, _Reason, _Data}, HTTP2Machine} ->
terminate(State#http2_state{http2_machine=HTTP2Machine},
{stop, Frame, 'Server is going away.'});
{send, SendData, HTTP2Machine} ->
send_data(maybe_ack(State#http2_state{http2_machine=HTTP2Machine}, Frame), SendData);
{error, {stream_error, StreamID, Reason, Human}, HTTP2Machine} ->
reset_stream(State#http2_state{http2_machine=HTTP2Machine},
StreamID, {stream_error, Reason, Human});
{error, Error={connection_error, _, _}, HTTP2Machine} ->
terminate(State#http2_state{http2_machine=HTTP2Machine}, Error)
end.
maybe_ack(State=#http2_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(State=#http2_state{socket=Socket, transport=Transport,
http2_machine=HTTP2Machine0}, StreamID, IsFin, Data) ->
Stream = #stream{handler_state=Handlers0} = get_stream_by_id(State, StreamID),
Handlers = gun_content_handler:handle(IsFin, Data, Handlers0),
Size = byte_size(Data),
HTTP2Machine = case Size of
%% We do not send a WINDOW_UPDATE if the DATA frame was of size 0.
0 ->
HTTP2Machine0;
_ ->
Transport:send(Socket, cow_http2:window_update(Size)),
HTTP2Machine1 = cow_http2_machine:update_window(Size, HTTP2Machine0),
%% We do not send a stream WINDOW_UPDATE if this was the last DATA frame.
case IsFin of
nofin ->
Transport:send(Socket, cow_http2:window_update(StreamID, Size)),
cow_http2_machine:update_window(StreamID, Size, HTTP2Machine1);
fin ->
HTTP2Machine1
end
end,
maybe_delete_stream(store_stream(State#http2_state{http2_machine=HTTP2Machine},
Stream#stream{handler_state=Handlers}), StreamID, remote, IsFin).
headers_frame(State=#http2_state{content_handlers=Handlers0},
StreamID, IsFin, Headers, PseudoHeaders, _BodyLen) ->
Stream = #stream{ref=StreamRef, reply_to=ReplyTo} = get_stream_by_id(State, StreamID),
case PseudoHeaders of
#{status := Status} when Status >= 100, Status =< 199 ->
ReplyTo ! {gun_inform, self(), StreamRef, Status, Headers},
State;
#{status := Status} ->
ReplyTo ! {gun_response, self(), StreamRef, IsFin, Status, Headers},
Handlers = case IsFin of
fin -> undefined;
nofin ->
gun_content_handler:init(ReplyTo, StreamRef,
Status, Headers, Handlers0)
end,
maybe_delete_stream(store_stream(State, Stream#stream{handler_state=Handlers}),
StreamID, remote, IsFin)
end.
trailers_frame(State, StreamID, Trailers) ->
#stream{ref=StreamRef, reply_to=ReplyTo} = get_stream_by_id(State, StreamID),
%% @todo We probably want to pass this to gun_content_handler?
ReplyTo ! {gun_trailers, self(), StreamRef, Trailers},
maybe_delete_stream(State, StreamID, remote, fin).
rst_stream_frame(State=#http2_state{streams=Streams0}, StreamID, Reason) ->
case lists:keytake(StreamID, #stream.id, Streams0) of
{value, #stream{ref=StreamRef, reply_to=ReplyTo}, Streams} ->
ReplyTo ! {gun_error, self(), StreamRef,
{stream_error, Reason, 'Stream reset by server.'}},
State#http2_state{streams=Streams};
false ->
State
end.
push_promise_frame(State=#http2_state{streams=Streams},
StreamID, PromisedStreamID, Headers, #{
method := Method, scheme := Scheme,
authority := Authority, path := Path}) ->
#stream{ref=StreamRef, reply_to=ReplyTo} = get_stream_by_id(State, StreamID),
PromisedStreamRef = make_ref(),
ReplyTo ! {gun_push, self(), StreamRef, PromisedStreamRef, Method,
iolist_to_binary([Scheme, <<"://">>, Authority, Path]), Headers},
NewStream = #stream{id=PromisedStreamID, ref=PromisedStreamRef, reply_to=ReplyTo},
State#http2_state{streams=[NewStream|Streams]}.
ignored_frame(State=#http2_state{http2_machine=HTTP2Machine0}) ->
case cow_http2_machine:ignored_frame(HTTP2Machine0) of
{ok, HTTP2Machine} ->
State#http2_state{http2_machine=HTTP2Machine};
{error, Error={connection_error, _, _}, HTTP2Machine} ->
terminate(State#http2_state{http2_machine=HTTP2Machine}, Error)
end.
%% @todo Use Reason.
close(_, #http2_state{streams=Streams}) ->
close_streams(Streams).
close_streams([]) ->
ok;
close_streams([#stream{ref=StreamRef, reply_to=ReplyTo}|Tail]) ->
ReplyTo ! {gun_error, self(), StreamRef, {closed,
"The connection was lost."}},
close_streams(Tail).
keepalive(State=#http2_state{socket=Socket, transport=Transport}) ->
Transport:send(Socket, cow_http2:ping(0)),
State.
headers(State=#http2_state{socket=Socket, transport=Transport,
http2_machine=HTTP2Machine0, streams=Streams},
StreamRef, ReplyTo, Method, Host, Port, Path, Headers0) ->
{ok, StreamID, HTTP2Machine1} = cow_http2_machine:init_stream(
iolist_to_binary(Method), HTTP2Machine0),
{ok, PseudoHeaders, Headers} = prepare_headers(State, Method, Host, Port, Path, Headers0),
{ok, IsFin, HeaderBlock, HTTP2Machine} = cow_http2_machine:prepare_headers(
StreamID, HTTP2Machine1, nofin, PseudoHeaders, Headers),
Transport:send(Socket, cow_http2:headers(StreamID, IsFin, HeaderBlock)),
Stream = #stream{id=StreamID, ref=StreamRef, reply_to=ReplyTo},
State#http2_state{http2_machine=HTTP2Machine, streams=[Stream|Streams]}.
request(State=#http2_state{socket=Socket, transport=Transport,
http2_machine=HTTP2Machine0, streams=Streams},
StreamRef, ReplyTo, Method, Host, Port, Path, Headers0, Body) ->
Headers1 = lists:keystore(<<"content-length">>, 1, Headers0,
{<<"content-length">>, integer_to_binary(iolist_size(Body))}),
{ok, StreamID, HTTP2Machine1} = cow_http2_machine:init_stream(
iolist_to_binary(Method), HTTP2Machine0),
{ok, PseudoHeaders, Headers} = prepare_headers(State, Method, Host, Port, Path, Headers1),
{ok, IsFin, HeaderBlock, HTTP2Machine} = cow_http2_machine:prepare_headers(
StreamID, HTTP2Machine1, nofin, PseudoHeaders, Headers),
Transport:send(Socket, cow_http2:headers(StreamID, IsFin, HeaderBlock)),
Stream = #stream{id=StreamID, ref=StreamRef, reply_to=ReplyTo},
maybe_send_data(State#http2_state{http2_machine=HTTP2Machine,
streams=[Stream|Streams]}, StreamID, fin, Body).
prepare_headers(#http2_state{transport=Transport}, Method, Host0, Port, Path, Headers0) ->
Authority = case lists:keyfind(<<"host">>, 1, Headers0) of
{_, Host} -> Host;
_ -> gun_http:host_header(Transport, Host0, Port)
end,
%% @todo We also must remove any header found in the connection header.
Headers =
lists:keydelete(<<"host">>, 1,
lists:keydelete(<<"connection">>, 1,
lists:keydelete(<<"keep-alive">>, 1,
lists:keydelete(<<"proxy-connection">>, 1,
lists:keydelete(<<"transfer-encoding">>, 1,
lists:keydelete(<<"upgrade">>, 1, Headers0)))))),
PseudoHeaders = #{
method => Method,
scheme => case Transport of
gun_tls -> <<"https">>;
gun_tcp -> <<"http">>
end,
authority => Authority,
path => Path
},
{ok, PseudoHeaders, Headers}.
data(State=#http2_state{http2_machine=HTTP2Machine}, StreamRef, ReplyTo, IsFin, Data) ->
case get_stream_by_ref(State, StreamRef) of
#stream{id=StreamID} ->
case cow_http2_machine:get_stream_local_state(StreamID, HTTP2Machine) of
{ok, fin, _} ->
error_stream_closed(State, StreamRef, ReplyTo);
{ok, _, fin} ->
error_stream_closed(State, StreamRef, ReplyTo);
{ok, _, _} ->
maybe_send_data(State, StreamID, IsFin, Data)
end;
false ->
error_stream_not_found(State, StreamRef, ReplyTo)
end.
maybe_send_data(State=#http2_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} ->
State#http2_state{http2_machine=HTTP2Machine};
{send, SendData, HTTP2Machine} ->
send_data(State#http2_state{http2_machine=HTTP2Machine}, SendData)
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_delete_stream(State, StreamID, local, 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=#http2_state{socket=Socket, transport=Transport},
StreamID, IsFin, {data, Data}) ->
Transport:send(Socket, cow_http2:data(StreamID, IsFin, Data)),
State;
%% @todo Uncomment this once sendfile is supported.
%send_data_frame(State=#http2_state{socket=Socket, transport=Transport},
% StreamID, IsFin, {sendfile, Offset, Bytes, Path}) ->
% Transport:send(Socket, cow_http2:data_header(StreamID, IsFin, Bytes)),
% Transport:sendfile(Socket, Path, Offset, Bytes),
% State;
%% The stream is terminated in cow_http2_machine:prepare_trailers.
send_data_frame(State=#http2_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#http2_state{http2_machine=HTTP2Machine}.
reset_stream(State=#http2_state{socket=Socket, transport=Transport,
streams=Streams0}, StreamID, StreamError={stream_error, Reason, _}) ->
Transport:send(Socket, cow_http2:rst_stream(StreamID, Reason)),
case lists:keytake(StreamID, #stream.id, Streams0) of
{value, #stream{ref=StreamRef, reply_to=ReplyTo}, Streams} ->
ReplyTo ! {gun_error, self(), StreamRef, StreamError},
State#http2_state{streams=Streams};
false ->
State
end.
cancel(State=#http2_state{socket=Socket, transport=Transport,
http2_machine=HTTP2Machine0}, StreamRef, ReplyTo) ->
case get_stream_by_ref(State, StreamRef) of
#stream{id=StreamID} ->
{ok, HTTP2Machine} = cow_http2_machine:reset_stream(StreamID, HTTP2Machine0),
Transport:send(Socket, cow_http2:rst_stream(StreamID, cancel)),
delete_stream(State#http2_state{http2_machine=HTTP2Machine}, StreamID);
false ->
error_stream_not_found(State, StreamRef, ReplyTo)
end.
%% @todo Add unprocessed streams when GOAWAY handling is done.
down(#http2_state{streams=Streams}) ->
KilledStreams = [Ref || #stream{ref=Ref} <- Streams],
{KilledStreams, []}.
terminate(#http2_state{socket=Socket, transport=Transport,
http2_machine=HTTP2Machine, streams=Streams}, Reason) ->
%% The connection is going away either at the request of the server,
%% or because an error occurred in the protocol. Inform the streams.
%% @todo We should not send duplicate messages to processes.
%% @todo We should probably also inform the owner process.
%% @todo Somehow streams aren't removed on receiving a response.
_ = [ReplyTo ! {gun_error, self(), Reason} || #stream{reply_to=ReplyTo} <- Streams],
Transport:send(Socket, cow_http2:goaway(
cow_http2_machine:get_last_streamid(HTTP2Machine),
terminate_reason(Reason), <<>>)),
close.
terminate_reason({connection_error, Reason, _}) -> Reason;
terminate_reason({stop, _, _}) -> no_error.
%% Stream functions.
error_stream_closed(State, StreamRef, ReplyTo) ->
ReplyTo ! {gun_error, self(), StreamRef, {badstate,
"The stream has already been closed."}},
State.
error_stream_not_found(State, StreamRef, ReplyTo) ->
ReplyTo ! {gun_error, self(), StreamRef, {badstate,
"The stream cannot be found."}},
State.
%% Streams.
%% @todo probably change order of args and have state first? Yes.
get_stream_by_id(#http2_state{streams=Streams}, StreamID) ->
lists:keyfind(StreamID, #stream.id, Streams).
get_stream_by_ref(#http2_state{streams=Streams}, StreamRef) ->
lists:keyfind(StreamRef, #stream.ref, Streams).
store_stream(State=#http2_state{streams=Streams0}, Stream=#stream{id=StreamID}) ->
Streams = lists:keyreplace(StreamID, #stream.id, Streams0, Stream),
State#http2_state{streams=Streams}.
maybe_delete_stream(State=#http2_state{http2_machine=HTTP2Machine}, StreamID, local, fin) ->
case cow_http2_machine:get_stream_remote_state(StreamID, HTTP2Machine) of
{ok, fin} -> delete_stream(State, StreamID);
{error, closed} -> delete_stream(State, StreamID);
_ -> State
end;
maybe_delete_stream(State=#http2_state{http2_machine=HTTP2Machine}, StreamID, remote, fin) ->
case cow_http2_machine:get_stream_local_state(StreamID, HTTP2Machine) of
{ok, fin, _} -> delete_stream(State, StreamID);
{error, closed} -> delete_stream(State, StreamID);
_ -> State
end;
maybe_delete_stream(State, _, _, _) ->
State.
delete_stream(State=#http2_state{streams=Streams}, StreamID) ->
Streams2 = lists:keydelete(StreamID, #stream.id, Streams),
State#http2_state{streams=Streams2}.
