[sr-dev] WebSocket (RFC 6455) and draft-ibc-sipcore-sip-websocket on Kamailio

[Klaus Darilion]

See how this function works:

http://www.kamailio.org/dokuwiki/doku.php/core-cookbook:3.1.x#set_forward_close

It might help you

On 17.06.2012 15:11, Peter Dunkley wrote:
> Hi,
>
> One of the things I need to be able to do from the WebSocket module is to
> cleanly close TCP/TLS connections when I receive/send a Close() frame.
>
> Is there an easy way to do this from a Kamailio module?
>
> Regards,
>
> Peter
>
>> Hello,
>>
>> On 6/15/12 11:33 AM, Peter Dunkley wrote:
>>> Hi Daniel,
>>>
>>> Thanks for the encouragement.
>>>
>>> I could do with a guide here.  I think there is only a few hours work
>>> left to finish off the handshake and basic module stuff. After that I
>>> think the next step needs to be:
>>> - Getting the module to register with core to receive WS frames (which
>>> may arrive over TCP or TLS)
>>> - Giving the module/core the ability to "change" the connection the
>>> handshake came in on from SIP/HTTP to WS (so that new messages go
>>> straight to the handler in the new module)
>>> - In the module adding handling for Close, Ping, and Pong
>>> - To do the handling for Ping the module needs to be able to send WS
>>> frames out (over TCP or TLS)
>>> - In the module "printing" received binary and text frames (which will
>>> contain SIP requests)
>>>
>>> The bits I need help with here the most are the registering the module
>>> to receive the WS frames and sending WS frames (over TCP or TLS), and
>>> adding the ability for the module/core to "upgrade" the connection
>>> from SIP/HTTP to WS after successful handshake.
>>
>> I think of doing it like:
>> - when WS handshake is completed, mark the tcp connection as being WS
>> from the module (a new flag or so)
>> - then in the TCP read function (iirc, tcp_read.{c,h} in core) if the
>> connection is marked WS, then execute a callback that is registered by
>> the module
>> - this is pretty much how http and msrp work, but there the detection is
>> on the content, not on the socket type. HTTP is using so called no-SIP
>> content callback, while MSRP is using a dedicated core event
>>
>> For sending, using tcp_send(...) (looking at msrp module will give the
>> right directions) should do it -- the function takes the tcp connection
>> as parameter as well as the outgoing buffer and encrypts the content if
>> actually is over TLS. The send operation may become transparent as soon
>> as the algorithm for finding the connection can grep on WS/WSS protocol.
>>
>> Cheers,
>> Daniel
>>
>>>
>> --
>> Daniel-Constantin Mierla - http://www.asipto.com
>> http://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda
>> Kamailio Advanced Training, Seattle, USA, Sep 23-26, 2012 -
>> http://asipto.com/u/katu
>> Kamailio Practical Workshop, Netherlands, Sep 10-12, 2012 -
>> http://asipto.com/u/kpw
>>
>>
>
>