From: Cong Wang <xiyou.wangcong@gmail.com>
To: Eli Britstein <elibr@mellanox.com>
Cc: Davide Caratti <dcaratti@redhat.com>,
Eric Dumazet <eric.dumazet@gmail.com>,
Jiri Pirko <jiri@resnulli.us>,
Jamal Hadi Salim <jhs@mojatatu.com>,
"David S . Miller" <davem@davemloft.net>,
Linux Kernel Network Developers <netdev@vger.kernel.org>,
Shuang Li <shuali@redhat.com>,
Stephen Hemminger <stephen@networkplumber.org>
Subject: Re: [PATCH net v3 0/3] net/sched: fix actions reading the network header in case of QinQ packets
Date: Tue, 4 Jun 2019 10:55:13 -0700 [thread overview]
Message-ID: <CAM_iQpXsGc2EpGkLq_3tcgiD+Mshe1GvGuURwcmeBEqpmQaiTw@mail.gmail.com> (raw)
In-Reply-To: <82ec3877-8026-67f7-90d8-6e9988513fef@mellanox.com>
On Sat, Jun 1, 2019 at 9:22 PM Eli Britstein <elibr@mellanox.com> wrote:
>
> I think that's because QinQ, or VLAN is not an encapsulation. There is
> no outer/inner packets, and if you want to mangle fields in the packet
> you can do it and the result is well-defined.
Sort of, perhaps VLAN tags are too short to be called as an
encapsulation, my point is that it still needs some endpoints to push
or pop the tags, in a similar way we do encap/decap.
>
> BTW, the motivation for my fix was a use case were 2 VGT VMs
> communicating by OVS failed. Since OVS sees the same VLAN tag, it
> doesn't add explicit VLAN pop/push actions (i.e pop, mangle, push). If
> you force explicit pop/mangle/push you will break such applications.
From what you said, it seems act_csum is in the middle of packet
receive/transmit path. So, which is the one pops the VLAN tags in
this scenario? If the VM's are the endpoints, why not use act_csum
there?
Thanks.
next prev parent reply other threads:[~2019-06-04 17:55 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-31 17:26 [PATCH net v3 0/3] net/sched: fix actions reading the network header in case of QinQ packets Davide Caratti
2019-05-31 17:26 ` [PATCH net v3 1/3] net/sched: act_csum: pull all VLAN headers before checksumming Davide Caratti
2019-05-31 18:38 ` Cong Wang
2019-05-31 22:01 ` Davide Caratti
2019-05-31 22:50 ` Cong Wang
2019-06-02 4:22 ` Eli Britstein
2019-06-04 17:41 ` Cong Wang
2019-05-31 17:26 ` [PATCH net v3 2/3] net/sched: act_pedit: fix 'ex munge' on network header in case of QinQ packet Davide Caratti
2019-05-31 17:26 ` [PATCH net v3 3/3] net/sched: act_skbedit: fix 'inheritdsfield' " Davide Caratti
2019-05-31 18:42 ` [PATCH net v3 0/3] net/sched: fix actions reading the network header in case of QinQ packets Cong Wang
2019-05-31 22:01 ` Davide Caratti
2019-05-31 22:29 ` Cong Wang
2019-06-02 4:22 ` Eli Britstein
2019-06-04 17:55 ` Cong Wang [this message]
2019-06-04 18:19 ` Eli Britstein
2019-06-06 1:42 ` Cong Wang
2019-06-06 5:37 ` Eli Britstein
2019-06-11 0:52 ` Cong Wang
2019-06-11 4:43 ` Eli Britstein
2019-06-07 18:20 ` Davide Caratti
2019-06-08 11:19 ` Eli Britstein
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