# Re: \[PATCH v3 net-next 2/2\] net sched ife action: Introduce skb tcindex metadata encap decap

- From: David Miller \<davem@davemloft.net\>
- Date: 2016-09-20 01:57:23 
- List: netdev
- Page: https://ratatoskr.run/netdev/2016/09/11029567
- Thread: https://ratatoskr.run/netdev/2016/09/11029276/t.md

```text
From: Jamal Hadi Salim <jhs@mojatatu.com>
Date: Sun, 18 Sep 2016 07:31:43 -0400

> From: Jamal Hadi Salim <jhs@mojatatu.com>
> 
> Sample use case of how this is encoded:
> user space via tuntap (or a connected VM/Machine/container)
> encodes the tcindex TLV.
> 
> Sample use case of decoding:
> IFE action decodes it and the skb->tc_index is then used to classify.
> So something like this for encoded ICMP packets:
> 
> .. first decode then reclassify... skb->tcindex will be set
> sudo $TC filter add dev $ETH parent ffff: prio 2 protocol 0xbeef \
> u32 match u32 0 0 flowid 1:1 \
> action ife decode reclassify
> 
> ...next match the decode icmp packet...
> sudo $TC filter add dev $ETH parent ffff: prio 4 protocol ip \
> u32 match ip protocol 1 0xff flowid 1:1 \
> action continue
> 
> ... last classify it using the tcindex classifier and do someaction..
> sudo $TC filter add dev $ETH parent ffff: prio 5 protocol ip \
> handle 0x11 tcindex classid 1:1 \
> action blah..
> 
> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>

Applied.
```