Hi,
> Den 11. mai 2014 kl. 04:19 skrev Ben Pfaff <b...@nicira.com>:
>
>> On Sat, May 10, 2014 at 06:11:29PM +0200, Christian Stigen Larsen wrote:
>>
>> Ben Pfaff <b...@nicira.com>:
>>>> Is do_xlate_actions ("translate actions"?) the wrong place for this kind of
>>>> stuff? How can I get a pointer to the raw packet data?
>>>
>>> Usually, ofproto-dpif-xlate should not actually implement the OpenFlow
>>> actions.
>>
>> Sorry for being trigger-happy, but even if I chose to implement datapath
>> actions, how can I inspect the packet data? For some reason I get a
>> NULL-pointer in ctx->xin->packet, while, e.g., OFPACT_OUTPUT in
>> do_xlate_actions gets the full packet.
>
> Often the packet data is not available because userspace is not
> processing a particular packet. Instead, it is deciding what to do with
> the entire class of packets specified by the flow data. You are only
> guaranteed to get full packets if during processing you add a flag for
> "slow" processing as I described earlier.
Quick question: In odp-execute I call set_ether_type (cant remember the exact
name at the moment) on the ofpbuf packet. In my example this buffer has size=81.
That is all I do in my action, and I can clearly see that it's working -- it
sets the correct place under offset 12 in packet->l2 w/right number of bytes.
The action after mine is a simple output:1 action, and works too.
However, wireshark reports that the packet is now 67 bytes (from l2 and up) --
and my testing shows it indeed is. Strangely enough, data is capped from L3,
i.e. its tail is truncated. And 81-67=14, which is too much of a coincidence as
the eth hdr is exactly 14 bytes.
Again, all I do is set the ether type. Do you find this strange, or do you
immediately know that I must have forgotten setting any magic flags or fields?
If you can't think of anythinh it could be my code, but I've gone through it
several times, and I don't do any bad memmoves or stuff like that.
Regards,
Christian
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