GATE(8)				     Linux			       GATE(8)

NAME
       gate - Stream Gate Action

SYNOPSIS
       tc  ...	action gate
	       [ base-time BASETIME ] [ clockid CLOCKID ]
	       sched-entry <gate state> <interval 1> [ <internal priority>
       <max octets> ]
	       sched-entry <gate state> <interval 2> [ <internal priority>
       <max octets> ]
	       sched-entry <gate state> <interval 3> [ <internal priority>
       <max octets> ]
	       ......
	       sched-entry <gate state> <interval N> [ <internal priority>
       <max octets> ]


DESCRIPTION
       GATE action allows specified ingress frames can be passed at specific
       time slot, or be dropped at specific time slot. Tc filter filters the
       ingress frames, then tc gate action would specify which time slot and
       how many bytes these frames can be passed to device and which time slot
       frames would be dropped.	 Gate action also assign a base-time to tell
       when the entry list start.  Then gate action would start to repeat the
       gate entry list cyclically at the start base-time.  For the software
       simulation, gate action requires the user assign reference time clock
       type.


PARAMETERS
       base-time
	      Specifies the instant in nanoseconds, defining the time when the
	      schedule starts. If 'base-time' is a time in the past, the
	      schedule will start at

	      base-time + (N * cycle-time)

	      where N is the smallest integer so the resulting time is greater
	      than "now", and "cycle-time" is the sum of all the intervals of
	      the entries in the schedule. Without base-time specified, will
	      default to be 0.


       clockid
	      Specifies the clock to be used by qdisc's internal timer for
	      measuring time and scheduling events. Not valid if gate action
	      is used for offloading filter.  For example, tc filter command
	      with skip_sw parameter.


       sched-entry
	      There may multiple sched-entry parameters in a single schedule.
	      Each one has the format:

	      sched-entry <gate state> <interval> [ <internal priority> <max
	      octets> ]

	      <gate state> means gate states. 'open' keep gate open, 'close'
	      keep gate close.
	      <interval> means how much nano seconds for this time slot.
	      <internal priority> means internal priority value. Present of
	      the internal receiving queue for this stream. "-1" means
	      wildcard.	 <internal priority> and <max octets> can be omit
	      default to be "-1" which both
	       value to be "-1" for this <sched-entry>.
	      <max octets> means how many octets size could pass in this time
	      slot. Dropped if overlimited. "-1" means wildcard. <max octets>
	      can be omit default to be "-1" which value to be "-1" for this
	      <sched-entry>.
	      Note that <internal priority> and <max octets> are nothing
	      meaning for gate state is "close" in a "sched-entry". All frames
	      are dropped when "sched-entry" with "close" state.


EXAMPLES
       The following example shows tc filter frames source ip match to the
       192.168.0.20 will keep the gate open for 200ms and limit the traffic to
       8MB in this sched-entry. Then keep the traffic gate to be close for
       100ms.  Frames arrived at gate close state would be dropped. Then the
       cycle would run the gate entries periodically. The schedule will start
       at instant 200.0s using the reference CLOCK_TAI. The schedule is
       composed of two entries each of 300ms duration.

       # tc qdisc add dev eth0 ingress
       # tc filter add dev eth0 parent ffff: protocol ip \
		  flower skip_hw src_ip 192.168.0.20 \
		  action gate index 2 clockid CLOCK_TAI \
		  base-time 200000000000ns \
		  sched-entry open 200000000ns -1 8000000b \
		  sched-entry close 100000000ns


       Following commands is an example to filter a stream source mac match to
       the 10:00:80:00:00:00 icmp frames will be dropped at any time with
       cycle 200ms.  With a default basetime 0 and clockid is CLOCK_TAI as
       default.

       # tc qdisc add dev eth0 ingress
       # tc filter add dev eth0 parent ffff:  protocol ip \
	    flower ip_proto icmp dst_mac 10:00:80:00:00:00 \
	    action gate index 12 sched-entry close 200000000ns



AUTHORS
       Po Liu <Po.Liu@nxp.com>

iproute2			  12 Mar 2020			       GATE(8)