Websocket disconnects randomly

[cacharrin]

Hi David,

I'm having problems with the library, i'm using it on CoronaSDK, but socket disconnects randomly. I just enable some logs on the library. I will tell you what I think is causing the error, but really I don't know what is causing it. But maybe my info could be useful.

I'm testing with a server which I send data to it, then it returns the same data many times (about 1500 times)... so if I send "1", it returns "111111..." ("1" character 1500 times).

I saw on the logs that sometimes the "data" comes "splitted" in many parts... when the library finally receive all parts, an ONCLOSE is fired. When data is fully available and received "complete" ONCLOSE is not fired.

A little explanation here:

Can you check it please? What is causing this problem?

Thank you

PD: I attached the full log files log.txt

You can see for example

• On 18:36:16.484 data es received and its complete, 1111..., 2222... and 3333 finishes with "], below is the binary data, and below no ONCLOSE is fired
• That works ok about other 3 times but...
• On 18:36:28.533 the 1111... are not complete (its only part of the message), and below is the same in binary, then below, it receives the rest of the 1111 data, and 2222 and 33333, show its binary data and then an ONCLOSE is fired. (Exactly on 18:36:28.971)

Every time a message is received partially, and then the second part, below the binary data there is an ONCLOSE.

[dmccuskey]

hello cacharrin,

the websocket protocol allows a sent message to be split up into different packets and recombined later. for some reason, the recombination part is failing.

this process starts in function handleWSFrame():

        if fcode == ws_types.continuation then
            if not self:_insertFrameData( data ) then

it would appear that inside of _insertFrameData() one of those conditionals is evaluating to true which causes the function to return nil, and that causes handleWSFrame() to close the connection.

    -- there is no type for this frame and none from previous
    if ftype == nil and #frame.data == 0 then
        return nil
    end
    -- we already have a type/data from previous frame
    if ftype ~= nil and #frame.data > 0 then
        return nil
    end

please look and see which part is returning nil.

what websocket server are you using ?

also, looking around, i can't see where the frame is reset in case of error. (by calling self:_createNewFrame()). maybe a good place would be in self:_onOpen() which is called when the socket is connected.

[cacharrin]

Hi David, sorry for the late response.

After some research, we found that the CLOSE event is generated by this conditional (Red square in the image) This is on "dmc_corona/dmc_websockets/frame.lua" file.

Do you have any ideas why this could be happening?

[cacharrin]

David?

[dmccuskey]

hmm, not sure about that part. seems like the conditional may be incorrect given the error message listed.

https://tools.ietf.org/html/rfc6455#section-5.5 "All control frames MUST have a payload length of 125 bytes or less and MUST NOT be fragmented""

what happens when you comment-out that area in the red box ?

[cacharrin]

Thank you David, commenting those lines improves the connection stability :)

Now we have few disconnections... we will investigate further.

Thank you.

[dmccuskey]

it's been awhile since i researched the protocol ; i'm rather surprised that the Autobahn tests didn't catch that.

i'm curious, what websocket server are you using ?

[cacharrin]

Im using nodeJs + SocketIO

[arash9900]

@cacharrin @dmccuskey I encountered the same problem, Did you solve this?

[arash9900]

I commented the above red square, but now i got "Received reserved control frame" I checked that opcode value is 11 and fin is false in this condition. So whats the problem? I am using nodejs as server

[arash9900]

I did not find any answer , so i switched to socket in corona with this library:

https://github.com/Overtorment/NoobHub