Subject: Re: [v3,iproute2 1/2] iproute2:tc:action: add a gate control action

From: Stephen Hemminger <[email-masked]>
Date: Mon, 4 May 2020 17:05:12 -0700

On Sun,  3 May 2020 14:32:50 +0800
Po Liu <[email-masked]> wrote:

> Introduce a ingress frame gate control flow action.
> Tc gate action does the work like this:
> Assume there is a gate allow specified ingress frames can pass at
> specific time slot, and also drop at specific time slot. Tc filter
> chooses the ingress frames, and tc gate action would specify what slot
> does these frames can be passed to device and what time slot would be
> dropped.
> Tc gate action would provide an entry list to tell how much time gate
> keep open and how much time gate keep state close. Gate action also
> assign a start time to tell when the entry list start. Then driver would
> repeat the gate entry list cyclically.
> For the software simulation, gate action require the user assign a time
> clock type.
> 
> Below is the setting example in user space. Tc filter a stream source ip
> address is 192.168.0.20 and gate action own two time slots. One is last
> 200ms gate open let frame pass another is last 100ms gate close let
> frames dropped.
> 
>  # tc qdisc add dev eth0 ingress
>  # tc filter add dev eth0 parent ffff: protocol ip \
> 
>             flower src_ip 192.168.0.20 \
>             action gate index 2 clockid CLOCK_TAI \
>             sched-entry open 200000000 -1 -1 \
>             sched-entry close 100000000
> 
>  # tc chain del dev eth0 ingress chain 0
> 
> "sched-entry" follow the name taprio style. Gate state is
> "open"/"close". Follow the period nanosecond. Then next -1 is internal
> priority value means which ingress queue should put to. "-1" means
> wildcard. The last value optional specifies the maximum number of
> MSDU octets that are permitted to pass the gate during the specified
> time interval.
> 
> Below example shows filtering a stream with destination mac address is
> 10:00:80:00:00:00 and ip type is ICMP, follow the action gate. The gate
> action would run with one close time slot which means always keep close.
> The time cycle is total 200000000ns. The base-time would calculate by:
> 
>      1357000000000 + (N + 1) * cycletime
> 
> When the total value is the future time, it will be the start time.
> The cycletime here would be 200000000ns for this case.
> 
>  #tc filter add dev eth0 parent ffff:  protocol ip \
>            flower skip_hw ip_proto icmp dst_mac 10:00:80:00:00:00 \
>            action gate index 12 base-time 1357000000000 \
>            sched-entry CLOSE 200000000 \
>            clockid CLOCK_TAI
> 
> Signed-off-by: Po Liu <[email-masked]>

These changes are specific to net-next should be assigned to iproute2-next.
Will change delegation.