GATE

NAME
SYNOPSIS
DESCRIPTION
PARAMETERS
EXAMPLES
AUTHORS

NAME

gate − Stream Gate Action

SYNOPSIS

tc … action gate
[ base-time BASETIME ] [ clockid CLOCKID ]
sched-entry [ ]
sched-entry [ ]
sched-entry [ ]
……
sched-entry [ ]

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 bodies manpages.csv script_extrae_body.sh script.sh usr 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 [ ]

means gate states. ’open’ keep gate open, ’close’ keep gate close.
means how much nano seconds for this time slot.
means internal priority value. Present of the internal receiving queue for this stream. “-1” means wildcard. and can be omit default to be “-1” which both
value to be “-1” for this .
means how many octets size could pass in this time slot. Dropped if overlimited. “-1” means wildcard. can be omit default to be “-1” which value to be “-1” for this .
Note that and 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

AUTHORS

Po Liu