Hi, I am trying to extend the ssdp user helper in conntrackd to handle event subscriptions on a UPnP control point. The flow looks like this: 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 connection to control point's web server - Once this is complete, the subscription should work So, all of the port numbers except 1900 are dynamic, and thus each stage depends on the result of the previous stage. Therefore I need the callback to inspect the traffic for stages (1)-(3). Currently, ssdp_helper_cb() only gets called for stage (1). Is there something I can do when creating the expectation to tell netfilter that I would like to receive callbacks when the unicast reply from (2) is received? Alternatively, is there an iptables rule that I should be creating for this purpose? I tried this: iptables -t raw -I INPUT -m helper --helper ssdp -j CT --helper ssdp but `-m helper` did not work in the raw table, and `-j CT` did not work in the filter table. `-m state --state RELATED` also did not work in the raw table. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
