Tunnel metadata manipulation action in tc(8)				 Linux



NAME
       tunnel_key - Tunnel metadata manipulation

SYNOPSIS
       tc ... action tunnel_key { unset |  SET }

       SET :=  set src_ip ADDRESS dst_ip ADDRESS id KEY_ID dst_port UDP_PORT
	       tos TOS ttl TTL [ csum | nocsum ]


DESCRIPTION
       The tunnel_key action combined with a shared IP tunnel device, allows
       one to perform IP tunnel en- or decapsulation on a packet, reflected by
       the operation modes UNSET and SET.  The UNSET mode is optional - even
       without using it, the metadata information will be released
       automatically when packet processing will be finished.  UNSET function
       could be used in cases when traffic is forwarded between two tunnels,
       where the metadata from the first tunnel will be used for encapsulation
       done by the second tunnel.  SET mode requires the source and
       destination ip ADDRESS and the tunnel key id KEY_ID which will be used
       by the ip tunnel shared device to create the tunnel header. The
       tunnel_key action is useful only in combination with a mirred redirect
       action to a shared IP tunnel device which will use the metadata (for
       SET ) and unset the metadata created by it (for UNSET ).


OPTIONS
       unset  Unset the tunnel metadata created by the IP tunnel device.  This
	      function is not mandatory and might be used only in some
	      specific use cases (as explained above).

       set    Set tunnel metadata to be used by the IP tunnel device. Requires
	      src_ip and dst_ip options.  id , dst_port , geneve_opts ,
	      vxlan_opts and erspan_opts are optional.

	      id     Tunnel ID (for example VNI in VXLAN tunnel)

	      src_ip Outer header source IP address (IPv4 or IPv6)

	      dst_ip Outer header destination IP address (IPv4 or IPv6)

	      dst_port
		     Outer header destination UDP port

	      geneve_opts
		     Geneve variable length options.  geneve_opts is specified
		     in the form CLASS:TYPE:DATA, where CLASS is represented
		     as a 16bit hexadecimal value, TYPE as an 8bit hexadecimal
		     value and DATA as a variable length hexadecimal value.
		     Additionally multiple options may be listed using a comma
		     delimiter.

	      vxlan_opts
		     Vxlan metadata options.  vxlan_opts is specified in the
		     form GBP, as a 32bit number. Multiple options is not
		     supported.

	      erspan_opts
		     Erspan metadata options.  erspan_opts is specified in the
		     form VERSION:INDEX:DIR:HWID, where VERSION is represented
		     as a 8bit number, INDEX as an 32bit number, DIR and HWID
		     as a 8bit number.	Multiple options is not supported.
		     Note INDEX is used when VERSION is 1, and DIR and HWID
		     are used when VERSION is 2.

	      tos    Outer header TOS

	      ttl    Outer header TTL

	      [no]csum
		     Controls outer UDP checksum. When set to csum (which is
		     default), the outer UDP checksum is calculated and
		     included in the packets. When set to nocsum, outer UDP
		     checksum is zero. Note that when using zero UDP checksums
		     with IPv6, the other tunnel endpoint must be configured
		     to accept such packets.  In Linux, this would be the
		     udp6zerocsumrx option for the VXLAN tunnel interface.

		     If using nocsum with IPv6, be sure you know what you are
		     doing. Zero UDP checksums provide weaker protection
		     against corrupted packets. See RFC6935 for details.

	      nofrag disallow IP fragmentation.

EXAMPLES
       The following example encapsulates incoming ICMP packets on eth0 into a
       vxlan tunnel, by setting metadata to VNI 11, source IP 11.11.0.1 and
       destination IP 11.11.0.2, and by redirecting the packet with the
       metadata to device vxlan0, which will do the actual encapsulation using
       the metadata:

	      #tc qdisc add dev eth0 handle ffff: ingress
	      #tc filter add dev eth0 protocol ip parent ffff: \
		flower \
		  ip_proto icmp \
		action tunnel_key set \
		  src_ip 11.11.0.1 \
		  dst_ip 11.11.0.2 \
		  id 11 \
		action mirred egress redirect dev vxlan0

       Here is an example of the unset function: Incoming VXLAN traffic with
       outer IP's and VNI 11 is decapsulated by vxlan0 and metadata is unset
       before redirecting to tunl1 device:

	      #tc qdisc add dev eth0 handle ffff: ingress
	      #tc filter add dev vxlan0 protocol ip parent ffff:   flower \
		     enc_src_ip 11.11.0.2 enc_dst_ip 11.11.0.1 enc_key_id 11   action tunnel_key unset	action mirred egress redirect dev tunl1


SEE ALSO
       tc(8)

iproute2			  10 Nov 2016
				  Tunnel metadata manipulation action in tc(8)