Cc'ing Jozsef. On Fri, Oct 09, 2020 at 10:29:53AM +0200, Phil Sutter wrote: > Hi Pablo, > > On Thu, Oct 08, 2020 at 07:31:56PM +0200, Pablo Neira Ayuso wrote: > > On Fri, Oct 02, 2020 at 01:44:36PM +0200, Arturo Borrero Gonzalez wrote: > > > From: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> > > > > > > Previous to this patch, the basechain policy could not be properly configured if it wasn't > > > explictly set when loading the ruleset, leading to iptables-nft-restore (and ip6tables-nft-restore) > > > trying to send an invalid ruleset to the kernel. > > > > I have applied this with some amendments to the test file to cover > > the --noflush case. I think this is a real problem there, where you > > can combine to apply incremental updates to the ruleset. > > Yes, at least I can imagine people relying upon this behaviour. > > > For the --flush case, I still have doubts how to use this feature, not > > sure it is worth the effort to actually fix it. > > I even find it unintuitive as it retains state despite flushing. So am I. > But that is a significant divergence between legacy and nft: > > | # iptables -P FORWARD DROP > | # iptables-restore <<EOF > | *filter > | COMMIT > | EOF > | # iptables-save > > With legacy, the output is: > > | *filter > | :INPUT ACCEPT [0:0] > | :FORWARD DROP [0:0] > | :OUTPUT ACCEPT [0:0] > | COMMIT > > With nft, there's no output at all. What do you think, should we fix > that? If so, which side? Looks like a variant of the same usecase. So if basechains are not specified, then basechains policies are left as is, but ruleset is flushed. Semantics for this are: Flush out _everything_ (existing rules and non-chains) but only leave existing basechain policies in place as is. I wonder if this is intentional or a side effect of the --noflush support. I'm Cc'ing Jozsef, maybe he remembers. Because you're reaching my boundaries on the netfilter history for this one :-) > > We can revisit later, you can rewrite this later Phil. > > Sure, no problem. Thanks.
