1 This modules matches a given string by using some pattern matching strategy. It requires a linux kernel >= 2.6.14. 2 .TP 3 \fB\-\-algo\fP {\fBbm\fP|\fBkmp\fP} 4 Select the pattern matching strategy. (bm = Boyer-Moore, kmp = Knuth-Pratt-Morris) 5 .TP 6 \fB\-\-from\fP \fIoffset\fP 7 Set the offset from which it starts looking for any matching. If not passed, default is 0. 8 .TP 9 \fB\-\-to\fP \fIoffset\fP 10 Set the offset up to which should be scanned. That is, byte \fIoffset\fP-1 11 (counting from 0) is the last one that is scanned. 12 If not passed, default is the packet size. 13 .TP 14 [\fB!\fP] \fB\-\-string\fP \fIpattern\fP 15 Matches the given pattern. 16 .TP 17 [\fB!\fP] \fB\-\-hex\-string\fP \fIpattern\fP 18 Matches the given pattern in hex notation. 19 .TP 20 \fB\-\-icase\fP 21 Ignore case when searching. 22 .TP 23 Examples: 24 .IP 25 # The string pattern can be used for simple text characters. 26 .br 27 iptables \-A INPUT \-p tcp \-\-dport 80 \-m string \-\-algo bm \-\-string 'GET /index.html' \-j LOG 28 .IP 29 # The hex string pattern can be used for non-printable characters, like |0D 0A| or |0D0A|. 30 .br 31 iptables \-p udp \-\-dport 53 \-m string \-\-algo bm \-\-from 40 \-\-to 57 \-\-hex\-string '|03|www|09|netfilter|03|org|00|' 32
