[ovs-dev] [PATCH v4] netdev-linux: do not send packets to down tap ifaces.

Ben Pfaff blp at ovn.org
Tue Jan 23 20:31:53 UTC 2018


On Wed, Jan 17, 2018 at 10:09:58PM -0200, Flavio Leitner wrote:
> Today OVS pushes packets to the TAP interface ignoring its
> current state. That works because the kernel will return -EIO
> when it's not UP and OVS will just ignore that as it is not
> an OVS issue.
> 
> However, it causes a huge impact when broadcasts happen when
> using userspace datapath accelerated with DPDK (e.g.: action
> NORMAL).  This patch improves the situation by checking the
> TAP's interface state before issueing any syscall.
> 
> However, there might be use-cases moving interfaces to other
> networking namespaces and in that case, OVS can't retrieve
> the iface state (sets it to DOWN). That would stop the traffic
> breaking the use-case. This patch relies on netlink notifications
> to find out if the device is local or not. When it's local, the
> device state is checked otherwise it will behave as before.
> 
> Signed-off-by: Flavio Leitner <fbl at sysclose.org>

I applied this to master yesterday.  (It looks like I forgot to send an
email about it at the time.)  Thanks!


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