'index out of range' when central tries to unsubscribe

[empinator]

Hi,

I wrote a notifier service based on the given examples, but when noble is trying to unsubscribe from bleno's with this command:
characteristic.notify(false, notify._notifyDisable);

bleno is crashing with an 'index out of range'

buffer.js:604
    throw new RangeError('index out of range');
          ^
RangeError: index out of range
    at checkInt (buffer.js:604:11)

Peripheral:
Machine: Raspberry PI, Kernel 3.6.11+, Bluez 5.8, GBU521 Dongle
code: http://pastebin.com/bpUBihb5
console output: http://pastebin.com/2qwBY91p

Central:
Machine: Thinkpad T400s, Kernel 3.5.0-45-generic, Bluez 5.8, GBU521 Dongle
code: http://pastebin.com/Esa5xhvz
console output: http://pastebin.com/jZ81CgMM

any idea?
Thanks.

[empinator]

not being able to figure out the deeper reason behind to that issue, I at least modified a piece of code which removes the symptom

in lib/linux/l2cap-ble.js around line 650. When data is not of type Buffer I am converting it

...
    var data = this._handles[valueHandle].value;

    if(typeof data != "object"){
        console.log('data', data);
        var tdata = new Buffer(4);
        tdata.writeUInt32LE(data);
        data = tdata;
    }
    var dataLength = Math.min(data.length, this._mtu - 4);
...

[sandeepmistry]

@empinator sorry I haven't had a chance to look at your sample code, it's on my list of things to look at.

Can you console.log: data, data.length, and this._mtu here - one of them is causing the Buffer to be smaller than it should be (maybe a negative value).

[empinator]

        console.log('data', data);
        console.log('data.length', data.length);
        console.log('this._mtu', this._mtu);

->

data 1
data.length undefined
this._mtu 256

I know how it is having a project on the side which is fun but still not your day job :-)
Don't worry about not answering immediately, I am glad you do though.

[sandeepmistry]

I think I found the problem, when notify is enabled/disabled, the value is not stored as a Buffer.

Try changing, l2cap-ble.js line 820:

handle.value = value;

to

handle.value = data;

[sandeepmistry]

@empinator this should be fixed now, with the commit above, let me know if you have any issues.

[empinator]

awesome, thank you

[paixaop]

I also faced a similar problem but in my case the error was in my code the call to writeUInt32LE needs 4 bytes and I had initialized the value to a single byte buffer with Buffer.alloc(1).

Changing it to value: Buffer.alloc(4) in the appropriate characteristic class solved the issue.

new Bleno.Descriptor({
     // Client Characteristic Configuration
     uuid: '2902',
     value: Buffer.alloc(4)
}),