On Tue, Dec 13, 2016 at 05:14:09PM +0100, Michal Miroslaw wrote: > On Tue, Dec 13, 2016 at 03:13:42PM +0000, Ananyev, Konstantin wrote: [...] > > > Dear Konstantin, > > > > > > Can you describe how the ACL code treats zero specially? I could not find > > > anything, really. The only thing I found is that iff I use zero userdata > > > in a rule I won't be able to differentiate a case where it matched from > > > a case where no rule matched. > > > > Yes, that's what I am talking about. > > > > > If I all my rules have non-zero userdata, > > > then this patch changes nothing. > > > > Ok, then why do you remove a code that does checking for invalid > > userdata==0? > > That supposed to prevent user to setup invalid value by mistake. > > > > But if I have a table where 0 means drop > > > (default-drop policy) then being able to use zero userdata in DROP rules > > > makes the ACLs just that more useful. > > > > Ok, and what prevents you from do +1 to your policy values before > > you insert it into the ACL table and -1 after you retrieved it via > > rte_acl_classify()? > > The check is enforcing an assumption that all users want to distinguish > the cases whether any rule matched and whether no rules matched. Not all > users do, hence the assumption is invalid and this patch removes it. > > Yes, people can work around it by loosing 1 of 2^32 useful values and > convoluting their code. > > You seem to argue that 0 is somehow an invalid value, but I can't find > anything in the ACL that would require it to be so. Could you point me > to the code in DPDK where this actually matters?
I just noticed that it's probably you who wrote most of the ACLs code, so I guest you're the right person to ask the question above. Nice work, BTW. :-) Best Regards, Michał Mirosław
