diff options
Diffstat (limited to 'src/cowboy_websocket.erl')
| -rw-r--r-- | src/cowboy_websocket.erl | 162 |
1 files changed, 30 insertions, 132 deletions
diff --git a/src/cowboy_websocket.erl b/src/cowboy_websocket.erl index 51fed54..bffffd8 100644 --- a/src/cowboy_websocket.erl +++ b/src/cowboy_websocket.erl @@ -12,7 +12,10 @@ %% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF %% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. -%% @doc WebSocket protocol implementation. +%% @doc Websocket protocol implementation. +%% +%% Cowboy supports versions 7 through 17 of the Websocket drafts. +%% It also supports RFC6455, the proposed standard for Websocket. -module(cowboy_websocket). %% API. @@ -41,22 +44,19 @@ env :: cowboy_middleware:env(), socket = undefined :: inet:socket(), transport = undefined :: module(), - version :: 0 | 7 | 8 | 13, handler :: module(), handler_opts :: any(), - challenge = undefined :: undefined | binary() | {binary(), binary()}, + key = undefined :: undefined | binary(), timeout = infinity :: timeout(), timeout_ref = undefined :: undefined | reference(), messages = undefined :: undefined | {atom(), atom(), atom()}, hibernate = false :: boolean(), - eop :: undefined | tuple(), %% hixie-76 specific. - origin = undefined :: undefined | binary(), %% hixie-76 specific. frag_state = undefined :: frag_state() }). -%% @doc Upgrade a HTTP request to the WebSocket protocol. +%% @doc Upgrade an HTTP request to the Websocket protocol. %% -%% You do not need to call this function manually. To upgrade to the WebSocket +%% You do not need to call this function manually. To upgrade to the Websocket %% protocol, you simply need to return <em>{upgrade, protocol, {@module}}</em> %% in your <em>cowboy_http_handler:init/3</em> handler function. -spec upgrade(Req, Env, module(), any()) @@ -84,36 +84,13 @@ websocket_upgrade(State, Req) -> {ok, [<<"websocket">>], Req3} = cowboy_req:parse_header(<<"upgrade">>, Req2), {Version, Req4} = cowboy_req:header(<<"sec-websocket-version">>, Req3), - websocket_upgrade(Version, State, Req4). - -%% @todo Handle the Sec-Websocket-Protocol header. -%% @todo Reply a proper error, don't die, if a required header is undefined. --spec websocket_upgrade(undefined | <<_:8>>, #state{}, Req) - -> {ok, #state{}, Req} when Req::cowboy_req:req(). -%% No version given. Assuming hixie-76 draft. -%% -%% We need to wait to send a reply back before trying to read the -%% third part of the challenge key, because proxies will wait for -%% a reply before sending it. Therefore we calculate the challenge -%% key only in websocket_handshake/3. -websocket_upgrade(undefined, State, Req) -> - {Origin, Req2} = cowboy_req:header(<<"origin">>, Req), - {Key1, Req3} = cowboy_req:header(<<"sec-websocket-key1">>, Req2), - {Key2, Req4} = cowboy_req:header(<<"sec-websocket-key2">>, Req3), - false = lists:member(undefined, [Origin, Key1, Key2]), - EOP = binary:compile_pattern(<< 255 >>), - {ok, State#state{version=0, origin=Origin, challenge={Key1, Key2}, - eop=EOP}, cowboy_req:set_meta(websocket_version, 0, Req4)}; -%% Versions 7 and 8. Implementation follows the hybi 7 through 17 drafts. -websocket_upgrade(Version, State, Req) - when Version =:= <<"7">>; Version =:= <<"8">>; - Version =:= <<"13">> -> - {Key, Req2} = cowboy_req:header(<<"sec-websocket-key">>, Req), - false = Key =:= undefined, - Challenge = hybi_challenge(Key), IntVersion = list_to_integer(binary_to_list(Version)), - {ok, State#state{version=IntVersion, challenge=Challenge}, - cowboy_req:set_meta(websocket_version, IntVersion, Req2)}. + true = (IntVersion =:= 7) orelse (IntVersion =:= 8) + orelse (IntVersion =:= 13), + {Key, Req5} = cowboy_req:header(<<"sec-websocket-key">>, Req4), + false = Key =:= undefined, + {ok, State#state{key=Key}, + cowboy_req:set_meta(websocket_version, IntVersion, Req5)}. -spec handler_init(#state{}, Req) -> {ok, Req, cowboy_middleware:env()} | {error, 400, Req} @@ -160,39 +137,10 @@ upgrade_error(Req, Env) -> -> {ok, Req, cowboy_middleware:env()} | {suspend, module(), atom(), [any()]} when Req::cowboy_req:req(). -websocket_handshake(State=#state{socket=Socket, transport=Transport, - version=0, origin=Origin, challenge={Key1, Key2}}, - Req, HandlerState) -> - {<< "http", Location/binary >>, Req1} = cowboy_req:url(Req), - {ok, Req2} = cowboy_req:upgrade_reply( - <<"101 WebSocket Protocol Handshake">>, - [{<<"upgrade">>, <<"WebSocket">>}, - {<<"sec-websocket-location">>, << "ws", Location/binary >>}, - {<<"sec-websocket-origin">>, Origin}], - Req1), - %% Flush the resp_sent message before moving on. - receive {cowboy_req, resp_sent} -> ok after 0 -> ok end, - %% We replied with a proper response. Proxies should be happy enough, - %% we can now read the 8 last bytes of the challenge keys and send - %% the challenge response directly to the socket. - %% - %% We use a trick here to read exactly 8 bytes of the body regardless - %% of what's in the buffer. - {ok, Req3} = cowboy_req:init_stream( - fun cowboy_http:te_identity/2, {0, 8}, - fun cowboy_http:ce_identity/1, Req2), - case cowboy_req:body(Req3) of - {ok, Key3, Req4} -> - Challenge = hixie76_challenge(Key1, Key2, Key3), - Transport:send(Socket, Challenge), - handler_before_loop(State#state{messages=Transport:messages()}, - Req4, HandlerState, <<>>); - _Any -> - %% If an error happened reading the body, stop there. - handler_terminate(State, Req3, HandlerState, {error, closed}) - end; -websocket_handshake(State=#state{transport=Transport, challenge=Challenge}, +websocket_handshake(State=#state{transport=Transport, key=Key}, Req, HandlerState) -> + Challenge = base64:encode(crypto:sha( + << Key/binary, "258EAFA5-E914-47DA-95CA-C5AB0DC85B11" >>)), {ok, Req2} = cowboy_req:upgrade_reply( 101, [{<<"upgrade">>, <<"websocket">>}, @@ -201,8 +149,8 @@ websocket_handshake(State=#state{transport=Transport, challenge=Challenge}, %% Flush the resp_sent message before moving on. receive {cowboy_req, resp_sent} -> ok after 0 -> ok end, State2 = handler_loop_timeout(State), - handler_before_loop(State2#state{messages=Transport:messages()}, - Req2, HandlerState, <<>>). + handler_before_loop(State2#state{key=undefined, + messages=Transport:messages()}, Req2, HandlerState, <<>>). -spec handler_before_loop(#state{}, Req, any(), binary()) -> {ok, Req, cowboy_middleware:env()} @@ -261,26 +209,8 @@ handler_loop(State=#state{ %% No more data. websocket_data(State, Req, HandlerState, <<>>) -> handler_before_loop(State, Req, HandlerState, <<>>); -%% hixie-76 close frame. -websocket_data(State=#state{version=0}, Req, HandlerState, - << 255, 0, _Rest/binary >>) -> - websocket_close(State, Req, HandlerState, {normal, closed}); -%% hixie-76 data frame. We only support the frame type 0, same as the specs. -websocket_data(State=#state{version=0, eop=EOP}, Req, HandlerState, - Data = << 0, _/binary >>) -> - case binary:match(Data, EOP) of - {Pos, 1} -> - Pos2 = Pos - 1, - << 0, Payload:Pos2/binary, 255, Rest/bits >> = Data, - handler_call(State, Req, HandlerState, - Rest, websocket_handle, {text, Payload}, fun websocket_data/4); - nomatch -> - %% @todo We probably should allow limiting frame length. - handler_before_loop(State, Req, HandlerState, Data) - end; -%% incomplete hybi data frame. -websocket_data(State=#state{version=Version}, Req, HandlerState, Data) - when Version =/= 0, byte_size(Data) =:= 1 -> +%% Incomplete. +websocket_data(State, Req, HandlerState, Data) when byte_size(Data) =:= 1 -> handler_before_loop(State, Req, HandlerState, Data); %% 7 bit payload length prefix exists websocket_data(State, Req, HandlerState, @@ -361,8 +291,8 @@ websocket_data(State, Req, HandlerState, _Fin, _Rsv, Opcode, _Mask, PayloadLen, _Rest, _Data) when Opcode >= 8, PayloadLen > 125 -> websocket_close(State, Req, HandlerState, {error, badframe}); %% unfragmented message. unmask and dispatch the message. -websocket_data(State=#state{version=Version}, Req, HandlerState, _Fin=1, _Rsv=0, - Opcode, Mask, PayloadLen, Rest, Data) when Version =/= 0 -> +websocket_data(State, Req, HandlerState, _Fin=1, _Rsv=0, + Opcode, Mask, PayloadLen, Rest, Data) -> websocket_before_unmask( State, Req, HandlerState, Data, Rest, Opcode, Mask, PayloadLen); %% Something was wrong with the frame. Close the connection. @@ -370,7 +300,7 @@ websocket_data(State, Req, HandlerState, _Fin, _Rsv, _Opcode, _Mask, _PayloadLen, _Rest, _Data) -> websocket_close(State, Req, HandlerState, {error, badframe}). -%% hybi routing depending on whether unmasking is needed. +%% Routing depending on whether unmasking is needed. -spec websocket_before_unmask(#state{}, Req, any(), binary(), binary(), opcode(), 0 | 1, non_neg_integer() | undefined) -> {ok, Req, cowboy_middleware:env()} @@ -390,7 +320,7 @@ websocket_before_unmask(State, Req, HandlerState, Data, Opcode, Payload, MaskKey) end. -%% hybi unmasking. +%% Unmasking. -spec websocket_unmask(#state{}, Req, any(), binary(), opcode(), binary(), mask_key()) -> {ok, Req, cowboy_middleware:env()} @@ -434,7 +364,7 @@ websocket_unmask(State, Req, HandlerState, RemainingData, websocket_dispatch(State, Req, HandlerState, RemainingData, Opcode, Acc). -%% hybi dispatching. +%% Dispatching. -spec websocket_dispatch(#state{}, Req, any(), binary(), opcode(), binary()) -> {ok, Req, cowboy_middleware:env()} | {suspend, module(), atom(), [any()]} @@ -470,7 +400,7 @@ websocket_dispatch(State, Req, HandlerState, _RemainingData, 8, _Payload) -> %% Ping control frame. Send a pong back and forward the ping to the handler. websocket_dispatch(State=#state{socket=Socket, transport=Transport}, Req, HandlerState, RemainingData, 9, Payload) -> - Len = hybi_payload_length(byte_size(Payload)), + Len = payload_length_to_binary(byte_size(Payload)), Transport:send(Socket, << 1:1, 0:3, 10:4, 0:1, Len/bits, Payload/binary >>), handler_call(State, Req, HandlerState, RemainingData, websocket_handle, {ping, Payload}, fun websocket_data/4); @@ -563,13 +493,6 @@ websocket_opcode(pong) -> 10. -spec websocket_send(frame(), #state{}) -> ok | shutdown | {error, atom()}. -%% hixie-76 text frame. -websocket_send({text, Payload}, #state{ - socket=Socket, transport=Transport, version=0}) -> - Transport:send(Socket, [0, Payload, 255]); -%% Ignore all unknown frame types for compatibility with hixie 76. -websocket_send(_Any, #state{version=0}) -> - ok; websocket_send(Type, #state{socket=Socket, transport=Transport}) when Type =:= close -> Opcode = websocket_opcode(Type), @@ -589,7 +512,7 @@ websocket_send({Type = close, StatusCode, Payload}, #state{ Len = 2 + iolist_size(Payload), %% Control packets must not be > 125 in length. true = Len =< 125, - BinLen = hybi_payload_length(Len), + BinLen = payload_length_to_binary(Len), Transport:send(Socket, [<< 1:1, 0:3, Opcode:4, 0:1, BinLen/bits, StatusCode:16 >>, Payload]), shutdown; @@ -602,7 +525,7 @@ websocket_send({Type, Payload}, #state{socket=Socket, transport=Transport}) -> true -> true end, - BinLen = hybi_payload_length(Len), + BinLen = payload_length_to_binary(Len), Transport:send(Socket, [<< 1:1, 0:3, Opcode:4, 0:1, BinLen/bits >>, Payload]). @@ -620,10 +543,6 @@ websocket_send_many([Frame|Tail], State) -> -spec websocket_close(#state{}, Req, any(), {atom(), atom()}) -> {ok, Req, cowboy_middleware:env()} when Req::cowboy_req:req(). -websocket_close(State=#state{socket=Socket, transport=Transport, version=0}, - Req, HandlerState, Reason) -> - Transport:send(Socket, << 255, 0 >>), - handler_terminate(State, Req, HandlerState, Reason); websocket_close(State=#state{socket=Socket, transport=Transport}, Req, HandlerState, Reason) -> Transport:send(Socket, << 1:1, 0:3, 8:4, 0:8 >>), @@ -648,30 +567,9 @@ handler_terminate(#state{env=Env, handler=Handler, handler_opts=HandlerOpts}, end, {ok, Req, [{result, closed}|Env]}. -%% hixie-76 specific. - --spec hixie76_challenge(binary(), binary(), binary()) -> binary(). -hixie76_challenge(Key1, Key2, Key3) -> - IntKey1 = hixie76_key_to_integer(Key1), - IntKey2 = hixie76_key_to_integer(Key2), - erlang:md5(<< IntKey1:32, IntKey2:32, Key3/binary >>). - --spec hixie76_key_to_integer(binary()) -> integer(). -hixie76_key_to_integer(Key) -> - Number = list_to_integer([C || << C >> <= Key, C >= $0, C =< $9]), - Spaces = length([C || << C >> <= Key, C =:= 32]), - Number div Spaces. - -%% hybi specific. - --spec hybi_challenge(binary()) -> binary(). -hybi_challenge(Key) -> - Bin = << Key/binary, "258EAFA5-E914-47DA-95CA-C5AB0DC85B11" >>, - base64:encode(crypto:sha(Bin)). - --spec hybi_payload_length(0..16#7fffffffffffffff) +-spec payload_length_to_binary(0..16#7fffffffffffffff) -> << _:7 >> | << _:23 >> | << _:71 >>. -hybi_payload_length(N) -> +payload_length_to_binary(N) -> case N of N when N =< 125 -> << N:7 >>; N when N =< 16#ffff -> << 126:7, N:16 >>; |