On Tue, 19 Aug 2008, Luigi Rizzo wrote: > On Tue, Aug 19, 2008 at 11:12:04PM +1000, Ian Smith wrote: > > On Thu, 31 Jul 2008, Julian Elischer wrote: > ... > > > ipfw add 1000 skipto tablearg ip from any to table(31) > ... > > > see attached patch... (hopefully not stripped) > > > > > > Of course it is hoped that the rules you are skipping to are nearby > > > as it iterates through the rules following the skipto to find the > > > target, > > > > Until $someone adds a direct skipto target jump at the virtual machine > > code level - big recalc hit when adding/deleting rules/sets I suppose - > > it's still the fastest way to get from a to b, where b > a > > you mean with tables-based skipto targets ? Because the regular > skipto has been a constant-time op forever, even in ipfw1 i believe, > invalidating the target cache on a change and recomputing it the > fly at the first request.
Thanks; I'd completely missed the caching of skipto targets before, and it's all so well commented too. blushing, but glad for the good news. But yes I was pondering Julian's patch, which has to lookup_next_rule every time, and also Mike's bending of divert reentry rule number in ipfw-classifyd with similar intent, which also has to hunt forward in linear time for its target rule - or am I missing something else here? > > Speaking of which, should ipfw whinge when asked to skip backwards, > > which it can't, confirmed on a recent browse re Mike's ipfw-classifyd > > and a local test months ago. > > right... but the error can only be reliably detected in the kernel, > as the rule number is not always known when the rule is added. Yes I meant at run-time. On second thoughts, it'd be too easy a way to spam syslogd in the general case, but maybe reporting target < current rule for such dynamic forms of skipto might highlight config errors? I should STFU and resume lurking unless I can contribute code, I know. cheers, Ian _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "[EMAIL PROTECTED]"
