Jan Engelhardt wrote: > On Thursday 2010-04-01 15:48, Patrick McHardy wrote: >> Jan Engelhardt wrote: >>> On Thursday 2010-04-01 15:22, Patrick McHardy wrote: >>>>>>> Conntrack loops are prevented by using a dummy conntrack, just as >>>>>>> NOTRACK does. >>>>>> [...] >>>>>>> - When the cloned packets gets XFRMed or tunneled, its status switches >>>>>>> from "special" to "plain". Doing policy routing on them does not seem >>>>>>> so far-fetched. >>>>>> My question was about the case without conntrack. >>>>> Hm. Do you have any suggestion in countering a case whereby a user >>>>> does -I OUTPUT -j TEE without conntrack? >>>>> >>>>> Perhaps making nesting a feature that requires conntrack, such that the >>>>> non-CT case can't loop? >>>> If we drop the reentrancy thing, what should work is to prevent >>>> using loopback as output device and using something similar to >>>> the recursion counters tunnel devices used to have. >>> Nah. I'm going to pick a bit from struct skbuff to indicate the >>> packet was teed so as to avoid that loop. >> That's a bad idea, we shouldn't be adding new skb members for something >> as peripheral as this module. > > I would have done this, which does not add a member: > > IP6CB(skb)->flags |= IPSKB_CLONED; This doesn't work, the CB is not preserved across layers (which f.i. matters if you allow loopback destinations). Its also not preserved for clones. >> What's wrong with adding a reentrancy counter? > > Sounds like a plan. -- 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
