On Fri, Apr 25, 2014 at 1:06 AM, YAMAMOTO Takashi <yamam...@valinux.co.jp> wrote: >> On Thu, Apr 24, 2014 at 05:57:29PM +0900, YAMAMOTO Takashi wrote: >>> hi, >>> >>> > + * Due to the sample action there may be multiple possible eth types. >>> > + * In order to correctly validate actions all possible types are tracked >>> > + * and verified. This is done using struct eth_types. >>> >>> is there any real-world use cases of these actions inside a sample? >>> otherwise, how about just rejecting such combinations? >>> it doesn't seem to worth the code complexity to me. >>> (sorry if it has been already discussed. it's the first time for me >>> to seriously read this long-lived patch.) >> >> Good point, the code is rather complex. >> >> My understanding is that it comes into effect in the case >> of sflow or ipfix being configured on the bridge. I tend >> to think these are real-world use-cases, though that thinking >> is by no means fixed. >> >> My reading of the code is that in the case of sflow and ipfix a single >> sample rule appears at the beginning of the flow. And that it may be >> possible to replace the code that you are referring to with something >> simpler to handle these cases. > > it seems that they put only a userland action inside a sample. > it's what i expected from its name "sample".
Yes, that's the only current use case. In theory, this could be used more generally although nothing has come up yet. In retrospect, I regret the design of the sample action - not the part that allows it to handle different actions but the fact that the results can affect things outside of the sample action list. I think that if we had made it more like a subroutine then that would have retained all of the functionality but none of the complexity here. Perhaps if we can find a clean way to restructure it without breaking compatibility then that would simplify the validation here. >> >> My understanding is that the code you are referring to also comes into >> effect when a sample action (a Nicira extension) is used directly in a >> rule. I am less sure that this is a real-world case but the complex logic >> you are referring to should to handle this use-case. > > probably nicira folks can clarify? It's the same set of use cases, just extending it to OpenFlow to enable building sampling into different situations. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
