Userspace logging daemon for netfilter/iptables Project Homepage: https://netfilter.org/projects/ulogd/index.html Mailinglist: http://lists.gnumonks.org/mailman/listinfo/ulogd/ This is just a short README, pleaes see the more extensive documentation in the doc/ subdirectory. ===> IDEA This packages is intended for doing all netfilter related logging inside a userspace process. This includes - logging of ruleset violations via ipt_ULOG (kernel 2.4.18+) - logging of ruleset violations via nfnetlink_log (kernel 2.6.14+) - logging of connection startup/teardown (kernel 2.6.14+) - connection-based accounting (kernel 2.6.14+) ===> CONTENTS = ulogd daemon (ulogd) A sophisticated logging daemon core which uses a plugin for about anything. The daemon provides a plugin API for - input plugins - filter plugins - output plugins = documentation (doc) A quite verbose documentation of this package and it's configuration exists, please actually make use of it and read it :) ===> USAGE To be able to build ulogd, you need to have working developement files and and libraries for: - libnfnetlink - libmnl - libnetfilter_log [optional] - libnetfilter_conntrack [optional] - libnetfilter_acct [optional] Output plugins are build if the needed library and headers are found. This includes: - PCAP: libpcap - PGSQL: libpq - MySQL: libmysqlclient - SQLITE3: libsqlite3 - DBI: libdbi The build procedure is standard: $ ./configure $ make $ sudo make install After build, you need to edit the ulogd.conf file to define a stack or more to use. ===> EXAMPLES = NFLOG usage At first a simple example, which passes every outgoing packet to the userspace logging, using nfnetlink group 3. iptables -A OUTPUT -j NFLOG --nflog-group 3 A more advanced one, passing all incoming tcp packets with destination port 80 to the userspace logging daemon listening on netlink multicast group 32. All packets get tagged with the ulog prefix "inp" iptables -A INPUT -j NFLOG -p tcp --dport 80 --nflog-group 32 --nflog-prefix inp See iptables -j NFLOG -h for complete information about NFLOG. = NFCT usage To use connection logging, simply activate in ulogd.conf one stack using the NFCT plugin. For example, the following stack will do flow-based logging via LOGEMU: stack=ct1:NFCT,ip2str1:IP2STR,print1:PRINTFLOW,emu1:LOGEMU = NFACCT usage On ulogd side, activate a stack using the NFACCT module. You then need to create counters: # nfacct add ipv4.tcp # nfacct add ipv6.tcp.443 Once this is done, you can then create iptables matching rule that will increment each time a packet hit them: # iptables -A FORWARD -p tcp -m nfacct --nfacct-name ipv4.tcp # ip6tables -A FORWARD -p tcp --dport 443 -m nfacct --nfacct-name ipv6.tcp.443 # ip6tables -A FORWARD -p tcp --sport 443 -m nfacct --nfacct-name ipv6.tcp.443 NFACCT plugin will then dump periodically the counters and trigger an update of the output corresponding to the active stacks. ===> COPYRIGHT + CREDITS The code and documentation is (C) 2000-2006 by Harald Welte <laforge@gnumonks.org> (C) 2008-2012 Pablo Neira Ayuso <pablo@netfilter.org> (C) 2008-2013 Eric Leblond <eric@regit.org> Thanks also to the valuable contributions of Daniel Stone, Alexander Janssen, Michael Stolovitzsky and Jozsef Kadlecsik. Credits to Rusty Russell, James Morris, Marc Boucher and all the other netfilter hackers.

This is a companion discussion topic for the original entry at https://copr.fedorainfracloud.org/coprs/ryoh/ulogd/