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h1. Nftables

h2. Liens

* https://wiki.archlinux.org/index.php/Nftables

* https://home.regit.org/netfilter-en/nftables-quick-howto/

* http://wiki.nftables.org/

* https://lwn.net/Articles/324989/

h2. Pre-requis

* Debian jessie

* Kernel from experimental: https://packages.debian.org/fr/experimental/linux-image-3.14-rc7-amd64

* libnfnl package compiled from https://github.com/aborrero/pkg-libnftnl (bientot dans debian sid: https://ftp-master.debian.org/new/libnftnl_1.0.0+git20140122-1.html)

* nftales package compiled from: http://mentors.debian.net/debian/pool/main/n/nftables/nftables_0.100-1.dsc

h2. Examples

h3. Tools

<pre>

root@h7:~# nft --version

nftables v0.100 (keith-alexander-filter)

root@h7:~# cat /proc/version 

Linux version 3.14-rc7-amd64 (debian-kernel@lists.debian.org) (gcc version 4.8.2 (Debian 4.8.2-16) ) #1 SMP Debian 3.14~rc7-1~exp1 (2014-03-17)

</pre>

h3. UDP counter

<pre>

root@h7:~# nft add rule filter output udp dport 0-65535 ip daddr 91.224.149.151 counter

root@h7:~# nft list chain filter output -a -n

table ip filter {

	chain output {

		 type filter hook output priority 0;

		 ip protocol udp udp dport >= 0 udp dport <= 65535 counter packets 171479 bytes 256167178 # handle 13

		 ip protocol udp udp dport >= 0 udp dport <= 65535 ip daddr 91.224.149.151 counter packets 0 bytes 0 # handle 15

	}

}

root@h7:~# iperf -c 91.224.149.151 -u -b 100M

------------------------------------------------------------

Client connecting to 91.224.149.151, UDP port 5001

Sending 1470 byte datagrams

UDP buffer size:  208 KByte (default)

------------------------------------------------------------

[  3] local 91.224.149.2 port 41909 connected with 91.224.149.151 port 5001

[ ID] Interval       Transfer     Bandwidth

[  3]  0.0-10.0 sec   120 MBytes   100 Mbits/sec

[  3] Sent 85471 datagrams

read failed: Connection refused

[  3] WARNING: did not receive ack of last datagram after 1 tries.

root@h7:~# nft list chain filter output -a -n

table ip filter {

	chain output {

		 type filter hook output priority 0;

		 ip protocol udp udp dport >= 0 udp dport <= 65535 counter packets 256951 bytes 384184664 # handle 13

		 ip protocol udp udp dport >= 0 udp dport <= 65535 ip daddr 91.224.149.151 counter packets 85457 bytes 128014586 # handle 15

	}

}

root@h7:~# nft delete rule filter output handle 15

root@h7:~# nft list chain filter output -a -n

table ip filter {

	chain output {

		 type filter hook output priority 0;

		 ip protocol udp udp dport >= 0 udp dport <= 65535 counter packets 256982 bytes 384190532 # handle 13

	}

</pre>

<pre>

nft add rule filter output udp dport 0-65535 counter

nft add rule filter input ip daddr 91.224.149.2 counter

</pre>

h3. Log

<pre>

root@h7:~# modprobe xt_LOG  

root@h7:~# nft add rule filter output ip daddr 91.224.149.151 counter

root@h7:~# nft add rule filter output ip daddr 91.224.149.151 log

root@h7:~# nft list chain filter output -a -n

table ip filter {

	chain output {

		 type filter hook output priority 0;

		 ip daddr 91.224.149.151 counter packets 0 bytes 0 # handle 16

		 ip daddr 91.224.149.151 log # handle 17

	}

}

root@h7:~# ping -c 1 91.224.149.151

PING 91.224.149.151 (91.224.149.151) 56(84) bytes of data.

64 bytes from 91.224.149.151: icmp_seq=1 ttl=64 time=2.53 ms

--- 91.224.149.151 ping statistics ---

1 packets transmitted, 1 received, 0% packet loss, time 0ms

rtt min/avg/max/mdev = 2.530/2.530/2.530/0.000 ms

Message from syslogd@h7 at Mar 28 14:38:08 ...

 kernel:[ 6797.701781] IN= OUT=eth0.3131 SRC=91.224.149.2 DST=91.224.149.151 LEN=84 TOS=0x00 PREC=0x00 TTL=64 ID=7861 DF PROTO=ICMP TYPE=8 CODE=0 ID=26178 SEQ=1 UID=0 GID=0 

root@h7:~# nft list chain filter output -a -n

table ip filter {

	chain output {

		 type filter hook output priority 0;

		 ip daddr 91.224.149.151 counter packets 1 bytes 84 # handle 16

		 ip daddr 91.224.149.151 log # handle 17

	}

}

root@h7:~# nft delete rule filter output handle 17

root@h7:~# tail -1 /var/log/syslog 

Mar 28 14:38:08 h7 kernel: [ 6797.701781] IN= OUT=eth0.3131 SRC=91.224.149.2 DST=91.224.149.151 LEN=84 TOS=0x00 PREC=0x00 TTL=64 ID=7861 DF PROTO=ICMP TYPE=8 CODE=0 ID=26178 SEQ=1 UID=0 GID=0 

</pre>