On Tue, Aug 26, 2014 at 03:12:57PM +0200, Arturo Borrero Gonzalez wrote: > On 26 August 2014 14:14, Patrick McHardy <kaber@xxxxxxxxx> wrote: > > On Tue, Aug 26, 2014 at 01:09:54PM +0200, Pablo Neira Ayuso wrote: > >> Renaming the subject to make it to start a new discussion on something > >> related. Cc'ing Patrick too, perhaps he can pull some better idea out > >> of his hat. > >> > >> On Tue, Aug 26, 2014 at 11:57:16AM +0200, Arturo Borrero Gonzalez wrote: > >> > This code examples uses the new NFT_MSG_DELTABLE functionality to replace > >> > an entire ruleset in a single transaction/batch. > >> > >> Thanks for the example but we already have quite a lot of them, and > >> this is yet another almost copy and paste that would need to be > >> maintained. > >> > >> Please, implement this in nft. I think we can probably have an -x > >> option, eg. > > > > Agreed. The naive aproach seems to be something like this: > > > > - add a generation ID to the ruleset > > - dump the entire ruleset > > - generate delete commands for each existing rule/chain/set... > > - generate add commands for each new rule/chain/set... > > - send the entire thing to the kernel, including the generation ID > > - if the generation ID doesn't match, meaning the ruleset has changed > > since the last dump, return an error to userspace, retry > > The approach in my patchset is different: > > - generate a delete command that will flush all the previous ruleset > - generate add commands for each new rule/chain/set/tables > - send the batch to the kernel We're still going to require the generation ID anyway to catch interferences between rule updates and rule dumping. My plan is to make a patch to include this in the nfgenmsg->res_id when dumping the objects to userspace. The NLM_F_DUMP_INTR is partially solving the problem for us, but we really need that generation ID to catch changes between two object dumps. Anyway I think both approaches are compatible. The one Arturo is working should be faster if the kernel supports the flusing from the nfnl mutex. I think nft should make it the way Patrick proposes if the kernel doesn't support this command (ie. if it hits -EBUSY when trying to flush a table). -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
