1 files changed, 264 insertions, 0 deletions
diff --git a/src/cow_spdy.erl b/src/cow_spdy.erl
new file mode 100644
index 0000000..4856afd
--- /dev/null
+++ b/src/cow_spdy.erl
@@ -0,0 +1,264 @@
+%% Copyright (c) 2013, 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(cow_spdy).
+
+%% Zstream.
+-export([deflate_init/0]).
+-export([inflate_init/0]).
+
+%% Parse.
+-export([split/1]).
+-export([parse/2]).
+
+%% Build.
+-export([data/3]).
+-export([syn_stream/12]).
+-export([syn_reply/6]).
+-export([rst_stream/2]).
+%% @todo settings
+-export([ping/1]).
+-export([goaway/2]).
+%% @todo headers
+%% @todo window_update
+
+-include("cow_spdy.hrl").
+
+%% Zstream.
+
+deflate_init() ->
+	Zdef = zlib:open(),
+	ok = zlib:deflateInit(Zdef),
+	_ = zlib:deflateSetDictionary(Zdef, ?ZDICT),
+	Zdef.
+
+inflate_init() ->
+	Zinf = zlib:open(),
+	ok = zlib:inflateInit(Zinf),
+	Zinf.
+
+%% Parse.
+
+split(Data = << _:40, Length:24, _/bits >>)
+		when byte_size(Data) >= Length + 8 ->
+	Length2 = Length + 8,
+	<< Frame:Length2/binary, Rest/bits >> = Data,
+	{true, Frame, Rest};
+split(Data) ->
+	{false, Data}.
+
+parse(<< 0:1, StreamID:31, 0:7, IsFinFlag:1, _:24, Data/bits >>, _) ->
+	{data, StreamID, from_flag(IsFinFlag), Data};
+parse(<< 1:1, 3:15, 1:16, 0:6, IsUnidirectionalFlag:1, IsFinFlag:1,
+		_:25, StreamID:31, _:1, AssocToStreamID:31, Priority:3, _:5,
+		0:8, Rest/bits >>, Zinf) ->
+	case parse_headers(Rest, Zinf) of
+		{ok, Headers, [{<<":host">>, Host}, {<<":method">>, Method},
+				{<<":path">>, Path}, {<<":scheme">>, Scheme},
+				{<<":version">>, Version}]} ->
+			{syn_stream, StreamID, AssocToStreamID, from_flag(IsFinFlag),
+				from_flag(IsUnidirectionalFlag), Priority, Method,
+				Scheme, Host, Path, Version, Headers};
+		_ ->
+			{error, badprotocol}
+	end;
+parse(<< 1:1, 3:15, 2:16, 0:7, IsFinFlag:1, _:25,
+		StreamID:31, Rest/bits >>, Zinf) ->
+	case parse_headers(Rest, Zinf) of
+		{ok, Headers, [{<<":status">>, Status}, {<<":version">>, Version}]} ->
+			{syn_reply, StreamID, from_flag(IsFinFlag),
+				Status, Version, Headers};
+		_ ->
+			{error, badprotocol}
+	end;
+parse(<< 1:1, 3:15, 3:16, 0:8, _:56, StatusCode:32 >>, _)
+		when StatusCode =:= 0; StatusCode > 11 ->
+	{error, badprotocol};
+parse(<< 1:1, 3:15, 3:16, 0:8, _:25, StreamID:31, StatusCode:32 >>, _) ->
+	Status = case StatusCode of
+		1 -> protocol_error;
+		2 -> invalid_stream;
+		3 -> refused_stream;
+		4 -> unsupported_version;
+		5 -> cancel;
+		6 -> internal_error;
+		7 -> flow_control_error;
+		8 -> stream_in_use;
+		9 -> stream_already_closed;
+		10 -> invalid_credentials;
+		11 -> frame_too_large
+	end,
+	{rst_stream, StreamID, Status};
+parse(<< 1:1, 3:15, 4:16, 0:7, ClearSettingsFlag:1, _:24,
+		NbEntries:32, Rest/bits >>, _) ->
+	try
+		Settings = [begin
+			Is0 = 0,
+			Key = case ID of
+				1 -> upload_bandwidth;
+				2 -> download_bandwidth;
+				3 -> round_trip_time;
+				4 -> max_concurrent_streams;
+				5 -> current_cwnd;
+				6 -> download_retrans_rate;
+				7 -> initial_window_size;
+				8 -> client_certificate_vector_size
+			end,
+			{Key, Value, from_flag(PersistFlag), from_flag(WasPersistedFlag)}
+		end || << Is0:6, WasPersistedFlag:1, PersistFlag:1,
+			ID:24, Value:32 >> <= Rest],
+		NbEntries = length(Settings),
+		{settings, from_flag(ClearSettingsFlag), Settings}
+	catch _:_ ->
+		{error, badprotocol}
+	end;
+parse(<< 1:1, 3:15, 6:16, 0:8, _:24, PingID:32 >>, _) ->
+	{ping, PingID};
+parse(<< 1:1, 3:15, 7:16, 0:8, _:56, StatusCode:32 >>, _)
+		when StatusCode > 2 ->
+	{error, badprotocol};
+parse(<< 1:1, 3:15, 7:16, 0:8, _:25, LastGoodStreamID:31,
+		StatusCode:32 >>, _) ->
+	Status = case StatusCode of
+		0 -> ok;
+		1 -> protocol_error;
+		2 -> internal_error
+	end,
+	{goaway, LastGoodStreamID, Status};
+parse(<< 1:1, 3:15, 8:16, 0:7, IsFinFlag:1, _:25, StreamID:31,
+		Rest/bits >>, Zinf) ->
+	case parse_headers(Rest, Zinf) of
+		{ok, Headers, []} ->
+			{headers, StreamID, from_flag(IsFinFlag), Headers};
+		_ ->
+			{error, badprotocol}
+	end;
+parse(<< 1:1, 3:15, 9:16, 0:8, _:57, 0:31 >>, _) ->
+	{error, badprotocol};
+parse(<< 1:1, 3:15, 9:16, 0:8, _:25, StreamID:31,
+		_:1, DeltaWindowSize:31 >>, _) ->
+	{window_update, StreamID, DeltaWindowSize};
+parse(_, _) ->
+	{error, badprotocol}.
+
+parse_headers(Data, Zinf) ->
+	[<< NbHeaders:32, Rest/bits >>] = inflate(Zinf, Data),
+	parse_headers(Rest, NbHeaders, [], []).
+
+parse_headers(<<>>, 0, Headers, SpHeaders) ->
+	{ok, lists:reverse(Headers), lists:sort(SpHeaders)};
+parse_headers(<<>>, _, _, _) ->
+	error;
+parse_headers(_, 0, _, _) ->
+	error;
+parse_headers(<< 0:32, _/bits >>, _, _, _) ->
+	error;
+parse_headers(<< L1:32, Key:L1/binary, L2:32, Value:L2/binary, Rest/bits >>,
+		NbHeaders, Acc, SpAcc) ->
+	case Key of
+		<< $:, _/bits >> ->
+			parse_headers(Rest, NbHeaders - 1, Acc, [{Key, Value}|SpAcc]);
+		_ ->
+			parse_headers(Rest, NbHeaders - 1, [{Key, Value}|Acc], SpAcc)
+	end.
+
+inflate(Zinf, Data) ->
+	try
+		zlib:inflate(Zinf, Data)
+	catch _:_ ->
+		ok = zlib:inflateSetDictionary(Zinf, ?ZDICT),
+		zlib:inflate(Zinf, <<>>)
+	end.
+
+from_flag(0) -> false;
+from_flag(1) -> true.
+
+%% Build.
+
+data(StreamID, IsFin, Data) ->
+	IsFinFlag = to_flag(IsFin),
+	Length = iolist_size(Data),
+	[<< 0:1, StreamID:31, 0:7, IsFinFlag:1, Length:24 >>, Data].
+
+syn_stream(Zdef, StreamID, AssocToStreamID, IsFin, IsUnidirectional,
+		Priority, Method, Scheme, Host, Path, Version, Headers) ->
+	IsFinFlag = to_flag(IsFin),
+	IsUnidirectionalFlag = to_flag(IsUnidirectional),
+	HeaderBlock = build_headers(Zdef, [
+		{<<":method">>, Method},
+		{<<":scheme">>, Scheme},
+		{<<":host">>, Host},
+		{<<":path">>, Path},
+		{<<":version">>, Version}
+		|Headers]),
+	Length = 10 + iolist_size(HeaderBlock),
+	[<< 1:1, 3:15, 1:16, 0:6, IsUnidirectionalFlag:1, IsFinFlag:1,
+		Length:24, 0:1, StreamID:31, 0:1, AssocToStreamID:31,
+		Priority:3, 0:5, 0:8 >>, HeaderBlock].
+
+syn_reply(Zdef, StreamID, IsFin, Status, Version, Headers) ->
+	IsFinFlag = to_flag(IsFin),
+	HeaderBlock = build_headers(Zdef, [
+		{<<":status">>, Status},
+		{<<":version">>, Version}
+		|Headers]),
+	Length = 4 + iolist_size(HeaderBlock),
+	[<< 1:1, 3:15, 2:16, 0:7, IsFinFlag:1, Length:24,
+		0:1, StreamID:31 >>, HeaderBlock].
+
+rst_stream(StreamID, Status) ->
+	StatusCode = case Status of
+		protocol_error -> 1;
+		invalid_stream -> 2;
+		refused_stream -> 3;
+		unsupported_version -> 4;
+		cancel -> 5;
+		internal_error -> 6;
+		flow_control_error -> 7;
+		stream_in_use -> 8;
+		stream_already_closed -> 9;
+		invalid_credentials -> 10;
+		frame_too_large -> 11
+	end,
+	<< 1:1, 3:15, 3:16, 0:8, 8:24,
+		0:1, StreamID:31, StatusCode:32 >>.
+
+%% @todo settings
+
+ping(PingID) ->
+	<< 1:1, 3:15, 6:16, 0:8, 4:24, PingID:32 >>.
+
+goaway(LastGoodStreamID, Status) ->
+	StatusCode = case Status of
+		ok -> 0;
+		protocol_error -> 1;
+		internal_error -> 2
+	end,
+	<< 1:1, 3:15, 7:16, 0:8, 8:24,
+		0:1, LastGoodStreamID:31, StatusCode:32 >>.
+
+%% @todo headers
+%% @todo window_update
+
+build_headers(Zdef, Headers) ->
+	NbHeaders = length(Headers),
+	Headers2 = [begin
+		L1 = iolist_size(Key),
+		L2 = iolist_size(Value),
+		[<< L1:32 >>, Key, << L2:32 >>, Value]
+	end || {Key, Value} <- Headers],
+	zlib:deflate(Zdef, [<< NbHeaders:32 >>, Headers2], full).
+
+to_flag(false) -> 0;
+to_flag(true) -> 1.