[ovs-dev] [PATCH] datapath-windows: OVS_PACKET_ATTR_PROBE

[Eitan Eliahu]

Hi Ben,
In general it doesn't seem that if the datapath does not support an attribute it would fail. (In other words the parsing validation code will not fail if an attribute is not included in the policy array).
I am not sure if the addition of this specific attribute to the policy masks an issue or not.
Perhaps Alin can tell.
Thanks,
Eitan

-----Original Message-----
From: dev [mailto:dev-bounces at openvswitch.org] On Behalf Of Ben Pfaff
Sent: Wednesday, July 01, 2015 2:53 PM
To: Alin Serdean
Cc: dev at openvswitch.org
Subject: Re: [ovs-dev] [PATCH] datapath-windows: OVS_PACKET_ATTR_PROBE

On Wed, Jul 01, 2015 at 06:57:50PM +0000, Alin Serdean wrote:
> Since commit:
> https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_openvs
> witch_ovs_commit_2e460098bff351b9fddcb917447caa3b97a35d86&d=BQIGaQ&c=S
> qcl0Ez6M0X8aeM67LKIiDJAXVeAw-YihVMNtXt-uEs&r=CWsgHUxi6ExLXY798tmo3LJ4e
> 3geGYp56lkcH-5cLCY&m=wSN1s5IDTOoE-dDGQWtmN87LEkQnYq71hKWcn7d3SJk&s=8_A
> Va78P_KXRWsNoVVtFSjNbBrJjyie8OjjjH4U953U&e=
> a new packet attribute was introduced.
> 
> This patch adds OVS_PACKET_ATTR_PROBE to nlPktExecPolicy in 
> datapath-windows and ignores it for the moment to maintain binary compatibility.
> 
> Signed-off-by: Alin Gabriel Serdean <aserdean at cloudbasesolutions.com>
> Acked-by: Eitan Eliahu <eliahue at vmware.com>
> ---
> This patch should be applied on master and branch-2.4
> v2: add acked-by

This patch makes me worry a bit.  The Linux kernel and OVS userspace implementations of Netlink ignore attributes that they do not recognize, which allows for some kinds of compatibility.  To me, this patch implies that the Windows datapath reports an error when it sees an unrecognized attribute.  Is that correct?  If so, then that should be changed, because otherwise it will cause compatibility problems in the future.
_______________________________________________
dev mailing list
dev at openvswitch.org
https://urldefense.proofpoint.com/v2/url?u=http-3A__openvswitch.org_mailman_listinfo_dev&d=BQIGaQ&c=Sqcl0Ez6M0X8aeM67LKIiDJAXVeAw-YihVMNtXt-uEs&r=CWsgHUxi6ExLXY798tmo3LJ4e3geGYp56lkcH-5cLCY&m=wSN1s5IDTOoE-dDGQWtmN87LEkQnYq71hKWcn7d3SJk&s=TZgQzcgvt8NDu-lf_W0nI9BkcWxoExr-9T2PSSonAbk&e=