traffic shaping with tc and nft

traffic shaping with tc and nft

[Lars Noodén]

Hello,

I'm working on traffic shaping with tc and have some old iptables rules
with which I've tried to use iptables-translate to convert legacy
instructions to nftables.  For example, I have the following:

     iptables -t mangle -A OUTPUT -p tcp --match multiport \
	--sports 22,1965 -j MARK --set-mark 100

and the result is,

     nft add rule ip mangle OUTPUT ip protocol tcp \
	tcp sport {22,1965} counter meta mark set 0x64

However, nftables does not like that as-is and responds with an error:

     "Error: Could not process rule: No such file or directory"

I've obviously missed or misinterpreted something there.  What would be
the correct nft instruction(s) including any prerequisites?  Or what
traffic shaping guides are there for nftables with concrete examples?
I've pored over the wiki and it is great for the aspects which have
already become familiar but it is far too abstract for me for new areas.

$ uname -sr
Linux 5.10.63-v7l+

$ apt-cache policy nftables | head -n 2
nftables:
   Installed: 0.9.8-3.1

Thanks.
Lars

Re: traffic shaping with tc and nft

[Kamil Jońca]

Lars Noodén <lars.nooden@gmx.com> writes:

> Hello,
>
> I'm working on traffic shaping with tc and have some old iptables rules
> with which I've tried to use iptables-translate to convert legacy
> instructions to nftables.  For example, I have the following:
>
>     iptables -t mangle -A OUTPUT -p tcp --match multiport \
> 	--sports 22,1965 -j MARK --set-mark 100
>
> and the result is,
>
>     nft add rule ip mangle OUTPUT ip protocol tcp \
> 	tcp sport {22,1965} counter meta mark set 0x64

Blind shot: in nftables you have no OUTPUT chain by default so I suspect
you have to create it manually.

nft add chain ip mangle  OUTPUT ...

KJ


-- 
http://wolnelektury.pl/wesprzyj/teraz/

Re: traffic shaping with tc and nft

[Lars Noodén]

On 5/28/22 13:20, Kamil Jońca wrote:
> Lars Noodén <lars.nooden@gmx.com> writes:
>
>> Hello,
>>
>> I'm working on traffic shaping with tc and have some old iptables rules
>> with which I've tried to use iptables-translate to convert legacy
>> instructions to nftables.  For example, I have the following:
>>
>>      iptables -t mangle -A OUTPUT -p tcp --match multiport \
>> 	--sports 22,1965 -j MARK --set-mark 100
>>
>> and the result is,
>>
>>      nft add rule ip mangle OUTPUT ip protocol tcp \
>> 	tcp sport {22,1965} counter meta mark set 0x64
>
> Blind shot: in nftables you have no OUTPUT chain by default so I suspect
> you have to create it manually.
>
> nft add chain ip mangle  OUTPUT ...
>
> KJ

Thanks.  I think that was it.  I had to create both the table and the
chain first.

/Lars