[Linux] iptables extension module -string

iptable比對string的Config和Function

●相對應的Kconfig

linux-4.xx/net/netfilter/Kconfig

config NETFILTER_XT_MATCH_STRING
	tristate '"string" match support'
	depends on NETFILTER_ADVANCED
	select TEXTSEARCH
	select TEXTSEARCH_KMP
	select TEXTSEARCH_BM
	select TEXTSEARCH_FSM
	help
	  This option adds a `string' match, which allows you to look for
	  pattern matchings in packets.

	  To compile it as a module, choose M here.  If unsure, say N.

●BM(Boyer-Moore)和 KMP(Knuth-Morris-Pratt)是字串匹配的演算法

相對應的程式位置:

TEXTSEARCH → linux-4.xx/lib/textsearch.c

TEXTSEARCH_KMP → linux-4.xx/lib/ts_kmp.c

TEXTSEARCH_BM → linux-4.xx/lib/ts_bm.c

●比對url的位置

xt_string.c → textsearch_prepare(…)