[v3,iproute2 2/2] iproute2: add gate action man page

[Po Liu]

This patch is to add the man page for the tc gate action.

Signed-off-by: Po Liu <Po.Liu@xxxxxxx>
---
 man/man8/tc-gate.8 | 123 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 123 insertions(+)
 create mode 100644 man/man8/tc-gate.8

diff --git a/man/man8/tc-gate.8 b/man/man8/tc-gate.8
new file mode 100644
index 00000000..0f48d7f3
--- /dev/null
+++ b/man/man8/tc-gate.8
@@ -0,0 +1,123 @@
+.TH GATE 8 "12 Mar 2020" "iproute2" "Linux"
+.SH NAME
+gate \- Stream Gate Action
+.SH SYNOPSIS
+.B tc " ... " action gate
+.ti +8
+.B [ base-time
+BASETIME ]
+.B [ clockid
+CLOCKID ]
+.ti +8
+.B sched-entry
+<gate state> <interval 1> [ <internal priority> <max octets> ]
+.ti +8
+.B sched-entry
+<gate state> <interval 2> [ <internal priority> <max octets> ]
+.ti +8
+.B sched-entry
+<gate state> <interval 3> [ <internal priority> <max octets> ]
+.ti +8
+.B ......
+.ti +8
+.B sched-entry
+<gate state> <interval N> [ <internal priority> <max octets> ]
+
+.SH 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.
+
+.SH PARAMETERS
+
+.TP
+base-time
+.br
+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.
+
+.TP
+clockid
+.br
+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
+.B skip_sw
+parameter.
+
+.TP
+sched-entry
+.br
+There may multiple
+.B sched-entry
+parameters in a single schedule. Each one has the format:
+
+sched-entry <gate state> <interval> [ <internal priority> <max octets> ]
+
+.br
+<gate state> means gate states. 'open' keep gate open, 'close' keep gate close.
+.br
+<interval> means how much nano seconds for this time slot.
+.br
+<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>.
+.br
+<max octets> means how many octets size for 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>.
+.br
+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.
+
+.SH 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.
+
+.EX
+# 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 200000000000 \\
+           sched-entry open 200000000 -1 8000000 \\
+           sched-entry close 100000000
+
+.EE
+
+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.
+
+.EX
+# 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 200000000
+
+.EE
+
+.SH AUTHORS
+Po Liu <Po.Liu@xxxxxxx>
-- 
2.17.1