%% Copyright (c) 2016-2018, 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/1]).
-export([keepalive/1]).
-export([request/8]).
-export([request/9]).
-export([data/5]).
-export([cancel/3]).
-export([down/1]).
-record(stream, {
id :: non_neg_integer(),
ref :: reference(),
reply_to :: pid(),
%% Whether we finished sending data.
local = nofin :: fin | nofin,
%% Local flow control window (how much we can send).
local_window :: integer(),
%% Buffered data waiting for the flow control window to increase.
local_buffer = queue:new() :: queue:queue(
{fin | nofin, non_neg_integer(), iolist()}),
local_buffer_size = 0 :: non_neg_integer(),
local_trailers = undefined :: undefined | cow_http:headers(),
%% Whether we finished receiving data.
remote = nofin :: fin | nofin,
%% Remote flow control window (how much we accept to receive).
remote_window :: integer(),
%% 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(),
local_settings = #{
initial_window_size => 65535,
max_frame_size => 16384
} :: map(),
remote_settings = #{
initial_window_size => 65535
} :: map(),
%% Connection-wide flow control window.
local_window = 65535 :: integer(), %% How much we can send.
remote_window = 65535 :: integer(), %% How much we accept to receive.
streams = [] :: [#stream{}],
stream_id = 1 :: non_neg_integer(),
%% The client starts by sending a sequence of bytes as a preface,
%% followed by a potentially empty SETTINGS frame. Then the connection
%% is established and continues normally. An exception is when a HEADERS
%% frame is sent followed by CONTINUATION frames: no other frame can be
%% sent in between.
parse_state = undefined :: normal
| {continuation, cowboy_stream:streamid(), cowboy_stream:fin(), binary()},
%% HPACK decoding and encoding state.
decode_state = cow_hpack:init() :: cow_hpack:state(),
encode_state = cow_hpack:init() :: cow_hpack:state()
}).
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);
%% @todo max_frame_size_sent
do_check_options([Opt|_]) ->
{error, {options, {http2, Opt}}}.
name() -> http2.
init(Owner, Socket, Transport, Opts) ->
Handlers = maps:get(content_handlers, Opts, [gun_data_h]),
State = #http2_state{owner=Owner, socket=Socket,
transport=Transport, opts=Opts, content_handlers=Handlers,
parse_state=normal}, %% @todo Have a special parse state for preface.
#http2_state{local_settings=Settings} = State,
%% Send the HTTP/2 preface.
Transport:send(Socket, [
<< "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n">>,
cow_http2:settings(Settings)
]),
State.
handle(Data, State=#http2_state{buffer=Buffer}) ->
parse(<< Buffer/binary, Data/binary >>, State#http2_state{buffer= <<>>}).
parse(Data0, State0=#http2_state{buffer=Buffer, parse_state=PS}) ->
%% @todo Parse states: Preface. Continuation.
Data = << Buffer/binary, Data0/binary >>,
case cow_http2:parse(Data) of
{ok, Frame, Rest} when PS =:= normal ->
case frame(Frame, State0) of
close -> close;
State1 -> parse(Rest, State1)
end;
{ok, Frame, Rest} when element(1, PS) =:= continuation ->
case continuation_frame(Frame, State0) of
close -> close;
State1 -> parse(Rest, State1)
end;
{ignore, _} when element(1, PS) =:= continuation ->
terminate(State0, {connection_error, protocol_error,
'An invalid frame was received in the middle of a header block. (RFC7540 6.2)'});
{ignore, Rest} ->
parse(Rest, State0);
{stream_error, StreamID, Reason, Human, Rest} ->
parse(Rest, stream_reset(State0, StreamID, {stream_error, Reason, Human}));
Error = {connection_error, _, _} ->
terminate(State0, Error);
more ->
{state, State0#http2_state{buffer=Data}}
end.
%% DATA frame.
frame({data, StreamID, IsFin, Data}, State0=#http2_state{remote_window=ConnWindow}) ->
case get_stream_by_id(StreamID, State0) of
Stream0 = #stream{remote=nofin, remote_window=StreamWindow, handler_state=Handlers0} ->
Handlers = gun_content_handler:handle(IsFin, Data, Handlers0),
{Stream, State} = send_window_update(
Stream0#stream{remote_window=StreamWindow - byte_size(Data),
handler_state=Handlers},
State0#http2_state{remote_window=ConnWindow - byte_size(Data)}),
remote_fin(Stream, State, IsFin);
_ ->
%% @todo protocol_error if not existing
stream_reset(State0, StreamID, {stream_error, stream_closed,
'DATA frame received for a closed or non-existent stream. (RFC7540 6.1)'})
end;
%% Single HEADERS frame headers block.
frame({headers, StreamID, IsFin, head_fin, HeaderBlock}, State) ->
stream_decode_init(State, StreamID, IsFin, HeaderBlock);
%% HEADERS frame starting a headers block. Enter continuation mode.
frame({headers, StreamID, IsFin, head_nofin, HeaderBlockFragment}, State) ->
State#http2_state{parse_state={continuation, StreamID, IsFin, HeaderBlockFragment}};
%% Single HEADERS frame headers block with priority.
frame({headers, StreamID, IsFin, head_fin,
_IsExclusive, _DepStreamID, _Weight, HeaderBlock}, State) ->
stream_decode_init(State, StreamID, IsFin, HeaderBlock);
%% @todo HEADERS frame starting a headers block. Enter continuation mode.
%frame(State, {headers, StreamID, IsFin, head_nofin,
% _IsExclusive, _DepStreamID, _Weight, HeaderBlockFragment}) ->
% %% @todo Handle priority.
% State#http2_state{parse_state={continuation, StreamID, IsFin, HeaderBlockFragment}};
%% @todo PRIORITY frame.
%frame(State, {priority, _StreamID, _IsExclusive, _DepStreamID, _Weight}) ->
% %% @todo Validate StreamID?
% %% @todo Handle priority.
% State;
%% @todo RST_STREAM frame.
frame({rst_stream, StreamID, Reason}, State) ->
stream_reset(State, StreamID, {stream_error, Reason, 'Stream reset by server.'});
%% SETTINGS frame.
frame({settings, Settings}, State=#http2_state{socket=Socket, transport=Transport,
remote_settings=Settings0}) ->
Transport:send(Socket, cow_http2:settings_ack()),
State#http2_state{remote_settings=maps:merge(Settings0, Settings)};
%% Ack for a previously sent SETTINGS frame.
frame(settings_ack, State) -> %% @todo =#http2_state{next_settings=_NextSettings}) ->
%% @todo Apply SETTINGS that require synchronization.
State;
%% PUSH_PROMISE frame.
%% @todo Continuation.
frame({push_promise, StreamID, head_fin, PromisedStreamID, HeaderBlock},
State=#http2_state{streams=Streams, decode_state=DecodeState0}) ->
case get_stream_by_id(PromisedStreamID, State) of
false ->
case get_stream_by_id(StreamID, State) of
#stream{ref=StreamRef, reply_to=ReplyTo} ->
try cow_hpack:decode(HeaderBlock, DecodeState0) of
{Headers0, DecodeState} ->
{Method, Scheme, Authority, Path, Headers} = try
{value, {_, Method0}, Headers1} = lists:keytake(<<":method">>, 1, Headers0),
{value, {_, Scheme0}, Headers2} = lists:keytake(<<":scheme">>, 1, Headers1),
{value, {_, Authority0}, Headers3} = lists:keytake(<<":authority">>, 1, Headers2),
{value, {_, Path0}, Headers4} = lists:keytake(<<":path">>, 1, Headers3),
{Method0, Scheme0, Authority0, Path0, Headers4}
catch error:badmatch ->
stream_reset(State, StreamID, {stream_error, protocol_error,
'Malformed push promise; missing pseudo-header field. (RFC7540 8.1.2.3)'})
end,
NewStreamRef = make_ref(),
ReplyTo ! {gun_push, self(), StreamRef, NewStreamRef, Method,
iolist_to_binary([Scheme, <<"://">>, Authority, Path]), Headers},
NewStream = new_stream(PromisedStreamID, NewStreamRef, ReplyTo,
nofin, fin, State),
State#http2_state{streams=[NewStream|Streams], decode_state=DecodeState}
catch _:_ ->
terminate(State, {connection_error, compression_error,
'Error while trying to decode HPACK-encoded header block. (RFC7540 4.3)'})
end;
_ ->
stream_reset(State, StreamID, {stream_error, stream_closed,
'DATA frame received for a closed or non-existent stream. (RFC7540 6.1)'})
end;
_ ->
stream_reset(State, StreamID, {stream_error, todo, ''})
end;
%% PING frame.
frame({ping, Opaque}, State=#http2_state{socket=Socket, transport=Transport}) ->
Transport:send(Socket, cow_http2:ping_ack(Opaque)),
State;
%% Ack for a previously sent PING frame.
%%
%% @todo Might want to check contents but probably a waste of time.
frame({ping_ack, _Opaque}, State) ->
State;
%% GOAWAY frame.
frame(Frame={goaway, StreamID, _, _}, State) ->
terminate(State, StreamID, {stop, Frame, 'Client is going away.'});
%% Connection-wide WINDOW_UPDATE frame.
frame({window_update, Increment}, State=#http2_state{local_window=ConnWindow})
when ConnWindow + Increment > 16#7fffffff ->
terminate(State, {connection_error, flow_control_error,
'The flow control window must not be greater than 2^31-1. (RFC7540 6.9.1)'});
frame({window_update, Increment}, State=#http2_state{local_window=ConnWindow}) ->
send_data(State#http2_state{local_window=ConnWindow + Increment});
%% Stream-specific WINDOW_UPDATE frame.
frame({window_update, StreamID, Increment}, State0=#http2_state{streams=Streams0}) ->
case lists:keyfind(StreamID, #stream.id, Streams0) of
#stream{local_window=StreamWindow} when StreamWindow + Increment > 16#7fffffff ->
stream_reset(State0, StreamID, {stream_error, flow_control_error,
'The flow control window must not be greater than 2^31-1. (RFC7540 6.9.1)'});
Stream0 = #stream{local_window=StreamWindow} ->
{State, Stream} = send_data(State0,
Stream0#stream{local_window=StreamWindow + Increment}),
Streams = lists:keystore(StreamID, #stream.id, Streams0, Stream),
State#http2_state{streams=Streams};
false ->
%% @todo Receiving this frame on a stream in the idle state is an error.
%% WINDOW_UPDATE frames may be received for a short period of time
%% after a stream is closed. They must be ignored.
State0
end;
%% Unexpected CONTINUATION frame.
frame({continuation, StreamID, _, _}, State) ->
terminate(State, StreamID, {connection_error, protocol_error,
'CONTINUATION frames MUST be preceded by a HEADERS frame. (RFC7540 6.10)'}).
continuation_frame({continuation, StreamID, head_fin, HeaderBlockFragment1},
State=#http2_state{parse_state={continuation, StreamID, IsFin, HeaderBlockFragment0}}) ->
HeaderBlock = << HeaderBlockFragment0/binary, HeaderBlockFragment1/binary >>,
stream_decode_init(State#http2_state{parse_state=normal}, StreamID, IsFin, HeaderBlock);
continuation_frame({continuation, StreamID, head_nofin, HeaderBlockFragment1},
State=#http2_state{parse_state=
{continuation, StreamID, IsFin, HeaderBlockFragment0}}) ->
State#http2_state{parse_state={continuation, StreamID, IsFin,
<< HeaderBlockFragment0/binary, HeaderBlockFragment1/binary >>}};
continuation_frame(_, State) ->
terminate(State, {connection_error, protocol_error,
'An invalid frame was received in the middle of a header block. (RFC7540 6.2)'}).
send_window_update(Stream=#stream{id=StreamID, remote_window=StreamWindow0},
State=#http2_state{socket=Socket, transport=Transport, remote_window=ConnWindow0}) ->
%% @todo We should make the windows configurable.
MinConnWindow = 8000000,
MinStreamWindow = 1000000,
ConnWindow = if
ConnWindow0 =< MinConnWindow ->
Transport:send(Socket, cow_http2:window_update(MinConnWindow)),
ConnWindow0 + MinConnWindow;
true ->
ConnWindow0
end,
StreamWindow = if
StreamWindow0 =< MinStreamWindow ->
Transport:send(Socket, cow_http2:window_update(StreamID, MinStreamWindow)),
StreamWindow0 + MinStreamWindow;
true ->
StreamWindow0
end,
{Stream#stream{remote_window=StreamWindow},
State#http2_state{remote_window=ConnWindow}}.
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.
request(State=#http2_state{socket=Socket, transport=Transport, encode_state=EncodeState0,
streams=Streams, stream_id=StreamID}, StreamRef, ReplyTo,
Method, Host, Port, Path, Headers) ->
{HeaderBlock, EncodeState} = prepare_headers(EncodeState0, Transport, Method, Host, Port, Path, Headers),
IsFin = case (false =/= lists:keyfind(<<"content-type">>, 1, Headers))
orelse (false =/= lists:keyfind(<<"content-length">>, 1, Headers)) of
true -> nofin;
false -> fin
end,
Transport:send(Socket, cow_http2:headers(StreamID, IsFin, HeaderBlock)),
Stream = new_stream(StreamID, StreamRef, ReplyTo, nofin, IsFin, State),
State#http2_state{streams=[Stream|Streams], stream_id=StreamID + 2, encode_state=EncodeState}.
%% @todo Handle Body > 16MB. (split it out into many frames)
request(State0=#http2_state{socket=Socket, transport=Transport, encode_state=EncodeState0,
streams=Streams, stream_id=StreamID}, StreamRef, ReplyTo,
Method, Host, Port, Path, Headers0, Body) ->
Headers = lists:keystore(<<"content-length">>, 1, Headers0,
{<<"content-length">>, integer_to_binary(iolist_size(Body))}),
{HeaderBlock, EncodeState} = prepare_headers(EncodeState0, Transport, Method, Host, Port, Path, Headers),
Transport:send(Socket, cow_http2:headers(StreamID, nofin, HeaderBlock)),
Stream0 = new_stream(StreamID, StreamRef, ReplyTo, nofin, nofin, State0),
{State, Stream} = send_data(State0, Stream0, fin, Body),
State#http2_state{streams=[Stream|Streams], stream_id=StreamID + 2, encode_state=EncodeState}.
prepare_headers(EncodeState, Transport, Method, Host0, Port, Path, Headers0) ->
Host2 = case Host0 of
{local, _SocketPath} -> <<>>;
Tuple when is_tuple(Tuple) -> inet:ntoa(Tuple);
_ -> Host0
end,
Authority = case lists:keyfind(<<"host">>, 1, Headers0) of
{_, Host} -> Host;
_ -> [Host2, $:, integer_to_binary(Port)]
end,
%% @todo We also must remove any header found in the connection header.
Headers1 =
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)))))),
Headers = [
{<<":method">>, Method},
{<<":scheme">>, case Transport of
gun_tls -> <<"https">>;
gun_tcp -> <<"http">>
end},
{<<":authority">>, Authority},
{<<":path">>, Path}
|Headers1],
cow_hpack:encode(Headers, EncodeState).
data(State0, StreamRef, ReplyTo, IsFin, Data) ->
case get_stream_by_ref(StreamRef, State0) of
#stream{local=fin} ->
error_stream_closed(State0, StreamRef, ReplyTo);
Stream0 = #stream{} ->
{State, Stream} = send_data(State0, Stream0, IsFin, Data),
maybe_delete_stream(State, Stream);
false ->
error_stream_not_found(State0, StreamRef, ReplyTo)
end.
%% @todo Should we ever want to implement the PRIORITY mechanism,
%% this would be the place to do it. Right now, we just go over
%% all streams and send what we can until either everything is
%% sent or we run out of space in the window.
send_data(State=#http2_state{streams=Streams}) ->
resume_streams(State, Streams, []).
%% When SETTINGS_INITIAL_WINDOW_SIZE changes we need to update
%% the local stream windows for all active streams and perhaps
%% resume sending data.
%update_streams_local_window(State=#http2_state{streams=Streams0}, Increment) ->
% Streams = [
% S#stream{local_window=StreamWindow + Increment}
% || S=#stream{local_window=StreamWindow} <- Streams0],
% resume_streams(State, Streams, []).
%% When we receive an ack to a SETTINGS frame we sent we need to update
%% the remote stream windows for all active streams.
%update_streams_remote_window(State=#http2_state{streams=Streams0}, Increment) ->
% Streams = [
% S#stream{remote_window=StreamWindow + Increment}
% || S=#stream{remote_window=StreamWindow} <- Streams0],
% State#http2_state{streams=Streams}.
resume_streams(State, [], Acc) ->
State#http2_state{streams=lists:reverse(Acc)};
%% While technically we should never get < 0 here, let's be on the safe side.
resume_streams(State=#http2_state{local_window=ConnWindow}, Streams, Acc)
when ConnWindow =< 0 ->
State#http2_state{streams=lists:reverse(Acc, Streams)};
%% We rely on send_data/2 to do all the necessary checks about the stream.
resume_streams(State0, [Stream0|Tail], Acc) ->
{State1, Stream} = send_data(State0, Stream0),
resume_streams(State1, Tail, [Stream|Acc]).
send_data(State, Stream=#stream{local=Local, local_buffer_size=0, local_trailers=Trailers})
when (Trailers =/= undefined) andalso ((Local =:= idle) orelse (Local =:= nofin)) ->
send_trailers(State, Stream#stream{local_trailers=undefined}, Trailers);
%% @todo It's possible that the stream terminates. We must remove it.
send_data(State=#http2_state{local_window=ConnWindow},
Stream=#stream{local=IsFin, local_window=StreamWindow, local_buffer_size=BufferSize})
when ConnWindow =< 0; IsFin =:= fin; StreamWindow =< 0; BufferSize =:= 0 ->
{State, Stream};
send_data(State0, Stream0=#stream{local_buffer=Q0, local_buffer_size=BufferSize}) ->
%% We know there is an item in the queue.
{{value, {IsFin, DataSize, Data}}, Q} = queue:out(Q0),
{State, Stream} = send_data(State0,
Stream0#stream{local_buffer=Q, local_buffer_size=BufferSize - DataSize},
IsFin, Data, in_r),
send_data(State, Stream).
send_data(State, Stream, IsFin, Data) ->
send_data(State, Stream, IsFin, Data, in).
%% We can send trailers immediately if the queue is empty, otherwise we queue.
%% We always send trailer frames even if the window is empty.
send_data(State, Stream=#stream{local_buffer_size=0}, fin, {trailers, Trailers}, _) ->
send_trailers(State, Stream, Trailers);
send_data(State, Stream, fin, {trailers, Trailers}, _) ->
{State, Stream#stream{local_trailers=Trailers}};
%% Send data immediately if we can, buffer otherwise.
send_data(State=#http2_state{local_window=ConnWindow},
Stream=#stream{local_window=StreamWindow}, IsFin, Data, In)
when ConnWindow =< 0; StreamWindow =< 0 ->
{State, queue_data(Stream, IsFin, Data, In)};
send_data(State=#http2_state{socket=Socket, transport=Transport, opts=Opts,
remote_settings=RemoteSettings, local_window=ConnWindow},
Stream=#stream{id=StreamID, local_window=StreamWindow}, IsFin, Data, In) ->
RemoteMaxFrameSize = maps:get(max_frame_size, RemoteSettings, 16384),
ConfiguredMaxFrameSize = maps:get(max_frame_size_sent, Opts, infinity),
MaxSendSize = min(
min(ConnWindow, StreamWindow),
min(RemoteMaxFrameSize, ConfiguredMaxFrameSize)
),
case Data of
% {sendfile, Offset, Bytes, Path} when Bytes =< MaxSendSize ->
% Transport:send(Socket, cow_http2:data_header(StreamID, IsFin, Bytes)),
% Transport:sendfile(Socket, Path, Offset, Bytes),
% {State#http2_state{local_window=ConnWindow - Bytes},
% Stream#stream{local=IsFin, local_window=StreamWindow - Bytes}};
% {sendfile, Offset, Bytes, Path} ->
% Transport:send(Socket, cow_http2:data_header(StreamID, nofin, MaxSendSize)),
% Transport:sendfile(Socket, Path, Offset, MaxSendSize),
% send_data(State#http2_state{local_window=ConnWindow - MaxSendSize},
% Stream#stream{local_window=StreamWindow - MaxSendSize},
% IsFin, {sendfile, Offset + MaxSendSize, Bytes - MaxSendSize, Path}, In);
Iolist0 ->
IolistSize = iolist_size(Iolist0),
if
IolistSize =< MaxSendSize ->
Transport:send(Socket, cow_http2:data(StreamID, IsFin, Iolist0)),
{State#http2_state{local_window=ConnWindow - IolistSize},
Stream#stream{local=IsFin, local_window=StreamWindow - IolistSize}};
true ->
{Iolist, More} = cow_iolists:split(MaxSendSize, Iolist0),
Transport:send(Socket, cow_http2:data(StreamID, nofin, Iolist)),
send_data(State#http2_state{local_window=ConnWindow - MaxSendSize},
Stream#stream{local_window=StreamWindow - MaxSendSize},
IsFin, More, In)
end
end.
send_trailers(State=#http2_state{socket=Socket, transport=Transport, encode_state=EncodeState0},
Stream=#stream{id=StreamID}, Trailers) ->
{HeaderBlock, EncodeState} = cow_hpack:encode(Trailers, EncodeState0),
Transport:send(Socket, cow_http2:headers(StreamID, fin, HeaderBlock)),
{State#http2_state{encode_state=EncodeState}, Stream#stream{local=fin}}.
queue_data(Stream=#stream{local_buffer=Q0, local_buffer_size=Size0}, IsFin, Data, In) ->
DataSize = case Data of
% {sendfile, _, Bytes, _} -> Bytes;
Iolist -> iolist_size(Iolist)
end,
Q = queue:In({IsFin, DataSize, Data}, Q0),
Stream#stream{local_buffer=Q, local_buffer_size=Size0 + DataSize}.
cancel(State=#http2_state{socket=Socket, transport=Transport},
StreamRef, ReplyTo) ->
case get_stream_by_ref(StreamRef, State) of
#stream{id=StreamID} ->
Transport:send(Socket, cow_http2:rst_stream(StreamID, cancel)),
delete_stream(StreamID, State);
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, streams=Streams}, Reason) ->
%% Because a particular stream is unknown,
%% we're sending the error message to all streams.
%% @todo We should not send duplicate messages to processes.
%% @todo We should probably also inform the owner process.
_ = [ReplyTo ! {gun_error, self(), Reason} || #stream{reply_to=ReplyTo} <- Streams],
%% @todo LastGoodStreamID
Transport:send(Socket, cow_http2:goaway(0, terminate_reason(Reason), <<>>)),
close.
terminate(State=#http2_state{socket=Socket, transport=Transport}, StreamID, Reason) ->
case get_stream_by_id(StreamID, State) of
#stream{reply_to=ReplyTo} ->
ReplyTo ! {gun_error, self(), Reason},
%% @todo LastGoodStreamID
Transport:send(Socket, cow_http2:goaway(0, terminate_reason(Reason), <<>>)),
close;
_ ->
terminate(State, Reason)
end.
terminate_reason({connection_error, Reason, _}) -> Reason;
terminate_reason({stop, _, _}) -> no_error.
%% Stream functions.
stream_decode_init(State=#http2_state{decode_state=DecodeState0}, StreamID, IsFin, HeaderBlock) ->
try cow_hpack:decode(HeaderBlock, DecodeState0) of
{Headers, DecodeState} ->
stream_pseudo_headers_init(State#http2_state{decode_state=DecodeState},
StreamID, IsFin, Headers)
catch _:_ ->
terminate(State, {connection_error, compression_error,
'Error while trying to decode HPACK-encoded header block. (RFC7540 4.3)'})
end.
stream_pseudo_headers_init(State, StreamID, IsFin, Headers0) ->
case pseudo_headers(Headers0, #{}) of
{ok, PseudoHeaders, Headers} ->
stream_resp_init(State, StreamID, IsFin, Headers, PseudoHeaders);
%% @todo When we handle trailers properly:
% {ok, _, _} ->
% stream_malformed(State, StreamID,
% 'A required pseudo-header was not found. (RFC7540 8.1.2.3)');
%% Or:
% {ok, _, _} ->
% stream_reset(State, StreamID, {stream_error, protocol_error,
% 'Malformed response; missing :status in HEADERS frame. (RFC7540 8.1.2.4)'})
{error, HumanReadable} ->
stream_reset(State, StreamID, {stream_error, protocol_error, HumanReadable})
end.
pseudo_headers([{<<":status">>, _}|_], #{status := _}) ->
{error, 'Multiple :status pseudo-headers were found. (RFC7540 8.1.2.3)'};
pseudo_headers([{<<":status">>, Status}|Tail], PseudoHeaders) ->
try cow_http:status_to_integer(Status) of
IntStatus ->
pseudo_headers(Tail, PseudoHeaders#{status => IntStatus})
catch _:_ ->
{error, 'The :status pseudo-header value is invalid. (RFC7540 8.1.2.4)'}
end;
pseudo_headers([{<<":", _/bits>>, _}|_], _) ->
{error, 'An unknown or invalid pseudo-header was found. (RFC7540 8.1.2.1)'};
pseudo_headers(Headers, PseudoHeaders) ->
{ok, PseudoHeaders, Headers}.
stream_resp_init(State=#http2_state{content_handlers=Handlers0},
StreamID, IsFin, Headers, PseudoHeaders) ->
case get_stream_by_id(StreamID, State) of
Stream = #stream{ref=StreamRef, reply_to=ReplyTo, remote=nofin} ->
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,
remote_fin(Stream#stream{handler_state=Handlers}, State, IsFin);
%% @todo For now we assume that it's a trailer if there's no :status.
%% A better state machine is needed to distinguish between that and errors.
_ ->
%% @todo We probably want to pass this to gun_content_handler?
ReplyTo ! {gun_trailers, self(), StreamRef, Headers},
remote_fin(Stream, State, fin)
end;
_ ->
stream_reset(State, StreamID, {stream_error, stream_closed,
'HEADERS frame received for a closed or non-existent stream. (RFC7540 6.1)'})
end.
stream_reset(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 ->
%% @todo Unknown stream. Not sure what to do here. Check again once all
%% terminate calls have been written.
State
end.
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?
new_stream(StreamID, StreamRef, ReplyTo, Remote, Local, #http2_state{
local_settings=#{initial_window_size := RemoteWindow},
remote_settings=#{initial_window_size := LocalWindow}}) ->
#stream{id=StreamID, ref=StreamRef, reply_to=ReplyTo,
remote=Remote, remote_window=RemoteWindow,
local=Local, local_window=LocalWindow}.
get_stream_by_id(StreamID, #http2_state{streams=Streams}) ->
lists:keyfind(StreamID, #stream.id, Streams).
get_stream_by_ref(StreamRef, #http2_state{streams=Streams}) ->
lists:keyfind(StreamRef, #stream.ref, Streams).
delete_stream(StreamID, State=#http2_state{streams=Streams}) ->
Streams2 = lists:keydelete(StreamID, #stream.id, Streams),
State#http2_state{streams=Streams2}.
remote_fin(S=#stream{local=fin}, State, fin) ->
delete_stream(S#stream.id, State);
%% We always replace the stream in the state because
%% the content handler state has changed.
remote_fin(S, State=#http2_state{streams=Streams}, IsFin) ->
Streams2 = lists:keyreplace(S#stream.id, #stream.id, Streams,
S#stream{remote=IsFin}),
State#http2_state{streams=Streams2}.
maybe_delete_stream(State, Stream=#stream{local=fin, remote=fin}) ->
delete_stream(Stream#stream.id, State);
maybe_delete_stream(State=#http2_state{streams=Streams}, Stream) ->
State#http2_state{streams=
lists:keyreplace(Stream#stream.id, #stream.id, Streams, Stream)}.
