[ovs-discuss] GRE interface packet receive procedure

Gregory Rose gvrose8192 at gmail.com
Tue Mar 19 20:18:17 UTC 2019

On 3/19/2019 6:29 AM, pei Jikui wrote:
> hi,
> 1) I am reading the OVS source code about how a GRE interface in OVS 
> receives packets into OVS bridge.
>      I found there are two places that the GRE packets will possibly 
> be received into OVS bridge.
>     a) . The first place is when we create a gre interface with 
> gre_create->ovs_netdev_link->netdev_rx_handler_register
>           The register rx_handler is netdev_frame_hook which will 
> receive the packets into the ovs bridge.
>      b) The second place is located at the dp_init which will register 
> a packet handler function gre_rcv for GRE protocol packets.
>          gre_rcv will also receive the packets to OVS bridge.
> 2) My questions are,
>      a)  Which is the real receive handler for the GRE packets?
>      b) Is it possible that the packets could be received by both of 
> the two cases. If yes, for which scenarios will be match to each one?

OVS supports a user space datapath and a kernel datapath so it depends 
on whether you're using the user space datapath or the kernel datapath.

- Greg

> Thanks much.
> Jikui
> _______________________________________________
> discuss mailing list
> discuss at openvswitch.org
> https://mail.openvswitch.org/mailman/listinfo/ovs-discuss

More information about the discuss mailing list