> I want to add a packet or byte counter to the connection tracking module > in netfilter. That is, I want to track how many packets and bytes having > been sent through one connection. Where should I start? 1) Get the kernel source code. 2) Get enough RAM to hold the full kernel source code, and your normal apps. To test whether you have enough RAM, use 'vmstat' to see whether you start swapping on this command: find /usr/src/linux -type f | grep -l 'struct ip_conntrack' 3) you are set up for work with the kernel. "grep for this" is the basic navigation aid. Now that you have found the include file (they end in '.h') where 'struct ip_conntrack' is defined, add the neccessary counter fields to it. 4) Study the other files the find/grep above found, especially the files with 'conntrack' in their names. Add the counter updates to the relevant files. 5) Provide ways for userlevel to access those counters. I would be interested to hear about the access methods you imagine. 6) Test. Test. Test. > Any examples will be very helpful! A concrete example, would mean writing the code. I hope you persist and implement and share your code, because if you do, we will have an example. I hope my six step program, above, helps you along a bit. > btw, is there a search engine on netfilter's web page? I think that's > really helpful if people want to search for previous work and discussions. I'm sure that google has it indexed fully; use the advanced search features, there, to restrict any search to a particular domain. An example URL, searching for "byte counters" on www.netfilter.org, would be: http://www.google.com/search?q=+site%3Awww.netfilter.org+byte+counters best regards Patrick
