Netfilter

http://www.netfilter.org/

http://www.iptables.org/

http://phrack.org/issues/61/13.html

http://inai.de/documents/Netfilter_Modules.pdf

https://people.cs.clemson.edu/~westall/853/notes/netfilter.pdf

http://www.free-it.org/archiv/LT_History/2002/talks/Welte/lt-690870524.pdf

Linux的Netfilter框架深度思考-对比Cisco的ACL-

nftables相比iptables到底改变了什么