[ovs-discuss] Added new field in flow.h. But the xlate_actions gives mask value zero.

Ben Pfaff blp at nicira.com
Tue Aug 4 04:19:18 UTC 2015

On Tue, Aug 04, 2015 at 12:46:32AM +0000, jimson chacko wrote:
> Hi Ben,
> Thanks for the quick response.
> I am not sure whether the flow matches. But a few observations.
> 1. There are two flows seen in ofctl dump-flows output before the
> traffic starts. First one is a default rule with action as "NORMAL"
> (hub mode ?). Second one is the new flow which I added with ofctl
> (output is port 2).
> There is no flow in dpctl output at this stage.
> 2. When traffic is started, dpctl output shows only one entry with
> action 2,3. (traffic is entering via port 1). I can see the new field
> also in the dpctl output with mask as zero. As per my understanding,
> this is an evidence that the flow is matched in ovs-vswitchd. But why
> is the mask value zero and also why is the action set as 2,3 instead
> of 2 alone ?
> The packet counters in dpctl and the counters on the added flow in
> ofctl match. So statistics part seems to be fine.
> 3. I added one more flow with a different value for the new field
> using ofctl. Started traffic with both the previous value and new
> value simultaneously. I still observe that there is only one flow in
> dpctl output with the earlier entry. kernel is not able to distinguish
> the flows and the counters are incremented on the existing flow. There
> is no new flow seen in dpctl output.
> 4. Suppose the switch has only the "NORMAL" rule. I started the
> traffic. The hub mode rule is seen in dpctl. Then a flow is added with
> the new field using ofctl. Observed that the dpctl output is updated
> with the new field value and the mask still is zero. No change in the
> actions part.
> I put debug logs just after xlate_actions in the hadle_upcalls
> function. The mask value for other fields are printed along with the
> new field. Mask is as expected for other fields except the new field.
> I suspect the miniflow part. What are the changes required in miniflow
> when a new field is introduced in flow ?

Normally, no changes at all.

I guess your code has a bug.

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