Re: [PATCH V2 conntrack-tools] conntrackd: cthelper: ssdp: Track UPnP eventing

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Thu, Jan 05, 2017 at 01:42:20PM -0800, Kevin Cernekee wrote:
> The UPnP Device Architecture spec provides a way for devices to connect
> back to control points, called "Eventing" (chapter 4).  This sequence can
> look something like:
> 
> 1) Outbound multicast M-SEARCH packet (dst: 1900/udp)
>  - Create expectation for unicast reply from <any host> to source port
> 
> 2) Inbound unicast reply (there may be several of these from different devices)
>  - Find the device's URL, e.g.
>    LOCATION: http://192.168.1.123:1400/xml/device_description.xml
>  - Create expectation to track connections to this host:port (tcp)
> 
> 3) Outbound connection to device's web server (there will be several of these)
>  - Watch for a SUBSCRIBE request
>  - Find the control point's callback URL, e.g.
>    CALLBACK: <http://192.168.1.124:3500/notify>
>  - Create expectation to open up inbound connections to this host:port
> 
> 4) Inbound connections to control point's web server
>  - The device will send NOTIFY HTTP requests to inform the control point
>    of new events.  These can continue indefinitely.  Each NOTIFY
>    request arrives on a new TCP connection and may have a different
>    source port.
> 
> Add the necessary code to create expectations for each of these
> connections and rewrite the IP in the CALLBACK URL.  Tested with and
> without NAT.

I'm going to place this in the tree. Just follow up with fixes if
required.

Thanks Kevin.