Proper way to ipsec filtering

Proper way to ipsec filtering

[Kamil Jońca]

What is the best way to create rules used to ipsec traffic filtering?

So far I have bunch rules created per reqid like that:
table ip filter { # handle 13

chain INPUT { # handle 1
                type filter hook input priority filter; policy drop;
                iif "eth0" ipsec in reqid 1 counter packets 100672 bytes 11492891 jump ipsec-in-1 comment "ed19af3c-f504-11e9-b59d-00e081736ba6/1/in" # handle 326
                [...]

 }

[...]
        chain ipsec-in-1 { # handle 323
                ip saddr yyy ip daddr xxxx/24 counter packets 50871 bytes 5614784 jump c1 # handle 325
                ip protocol ipencap ip daddr zzzz counter packets 49801 bytes 5878107 accept # handle 324
        }

}

And insert / remove rules from INPUT  (and add / delete ipsec-in-*
chains) during connecting disconnecting clients.
This was I configured when I migrated from iptables some time ago.
But I believe this is not the best method for nftables. So has anybody
suggestion what is the best practicte to handle this situation?
I tried to use maps/vmaps but reqid cannot be use as index.

Am I missing something?
KJ

-- 
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Re: Proper way to ipsec filtering

[Florian Westphal]

Kamil Jońca <kjonca@op.pl> wrote:
> What is the best way to create rules used to ipsec traffic filtering?
> 
> So far I have bunch rules created per reqid like that:
> table ip filter { # handle 13
> 
> chain INPUT { # handle 1
>                 type filter hook input priority filter; policy drop;
>                 iif "eth0" ipsec in reqid 1 counter packets 100672 bytes 11492891 jump ipsec-in-1 comment "ed19af3c-f504-11e9-b59d-00e081736ba6/1/in" # handle 326
>                 [...]
[..]

> But I believe this is not the best method for nftables. So has anybody
> suggestion what is the best practicte to handle this situation?
> I tried to use maps/vmaps but reqid cannot be use as index.

Thats a bug / missing feature, it should be possible to use reqid in concatenated keys
too.  I've sent a patch for this:

https://patchwork.ozlabs.org/project/netfilter-devel/patch/20220418100924.5669-2-fw@strlen.de/

Re: Proper way to ipsec filtering

[Kamil Jońca]

Florian Westphal <fw@strlen.de> writes:

[...]
> Thats a bug / missing feature, it should be possible to use reqid in concatenated keys
> too.  I've sent a patch for this:
>
> https://patchwork.ozlabs.org/project/netfilter-devel/patch/20220418100924.5669-2-fw@strlen.de/
>

Well, I cloned repo, and compiled against my debian test sid box. Seems to
work as expected.

Thank you.
So now I have to wait when debian adopt it. :)
Thanks again.

KJ

-- 
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