Include some examples in the nftables tarball on using the ct helper infraestructure, inspired from wiki.nftables.org. Signed-off-by: Arturo Borrero Gonzalez <arturo@xxxxxxxxxxxxx> --- v2: fix some typos v3: fix typo in shebang reported by Florian files/examples/ct_helpers.nft | 43 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100755 files/examples/ct_helpers.nft diff --git a/files/examples/ct_helpers.nft b/files/examples/ct_helpers.nft new file mode 100755 index 0000000..07ebb2a --- /dev/null +++ b/files/examples/ct_helpers.nft @@ -0,0 +1,43 @@ +#!/usr/sbin/nft -f + +# This example file shows how to use ct helpers in the nftables framework. +# Note that nftables includes interesting improvements compared to how this +# was done with iptables, such as loading multiple helpers with a single rule +# This script is meant to be loaded with `nft -f <file>` +# You require linux kernel >= 4.12 and nft >= 0.8 +# For up-to-date information please visit https://wiki.nftables.org + +# Using ct helpers is an important security feature when doing stateful +# firewalling, since it mitigate certain networking attacks. +# More info at: https://home.regit.org/netfilter-en/secure-use-of-helpers/ + + +flush ruleset +table inet filter { + # declare helpers of this table + ct helper ftp-standard { + type "ftp" protocol tcp; + l3proto inet + } + ct helper sip-5060 { + type "sip" protocol udp; + l3proto inet + } + ct helper tftp-69 { + type "tftp" protocol udp + l3proto inet + } + + chain input { + type filter hook input priority 0; policy drop; + ct state established,related accept + + # assign a single helper in a single rule + tcp dport 21 ct helper set "ftp-standard" + + # assign multiple helpers in a single rule + ct helper set udp dport map { + 69 : "tftp-69", \ + 5060 : "sip-5060" } + } +} -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
