netdev - Re: [Patch net] wireguard: preserve skb->mark on ingress side

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAM_iQpV-JKrk8vaHDeD0pXaheN0APUxH5Lp+mGCM=_yZQ1hd4w@mail.gmail.com>
Date:   Mon, 27 Sep 2021 20:27:55 -0700
From:   Cong Wang <xiyou.wangcong@...il.com>
To:     "Jason A. Donenfeld" <Jason@...c4.com>
Cc:     Netdev <netdev@...r.kernel.org>,
        WireGuard mailing list <wireguard@...ts.zx2c4.com>,
        Cong Wang <cong.wang@...edance.com>,
        Peilin Ye <peilin.ye@...edance.com>
Subject: Re: [Patch net] wireguard: preserve skb->mark on ingress side

On Mon, Sep 27, 2021 at 8:22 PM Jason A. Donenfeld <Jason@...c4.com> wrote:
>
> Hi Cong,
>
> I'm not so sure this makes sense, as the inner packet is in fact
> totally different. If you want to distinguish the ingress interface,

The contents are definitely different, but skb itself is the same.

Please also take a look at other tunnels, they all preserve this
in similar ways, that is, comparing net namespaces. Any reason
why wireguard is so different from other tunnels?

> can't you just use `iptables -i wg0` or `ip rule add ... iif wg0`?
>

My bad, I forgot to mention we run eBPF on egress side, where
skb->dev is already set to egress device (a non-wireguard device),
and of course skb_iif has been cleared even earlier.

Thanks.