Hi Pablo, On Thu, Jul 23, 2020 at 02:22:57PM +0200, Pablo Neira Ayuso wrote: > On Sat, Jul 11, 2020 at 12:18:13PM +0200, Phil Sutter wrote: > > Work in this series centered around Harald's complaint about seemingly > > random custom chain ordering in iptables-nft-save output. nftables > > returns chains in the order they were created which differs from > > legacy iptables which sorts by name. > > > > The intuitive approach of simply sorting chains in tables' > > nftnl_chain_lists is problematic since base chains, which shall be > > dumped first, are contained in there as well. Patch 15 solves this by > > introducing a per-table array of nftnl_chain pointers to hold only base > > chains (the hook values determine the array index). The old > > nftnl_chain_list now contains merely non-base chains and is sorted upon > > population by the new nftnl_chain_list_add_sorted() function. > > > > Having dedicated slots for base chains allows for another neat trick, > > namely to create only immediately required base chains. Apart from the > > obvious case, where adding a rule to OUTPUT chain doesn't cause creation > > of INPUT or FORWARD chains, this means ruleset modifications can be > > avoided completely when listing, flushing or zeroing counters (unless > > chains exist). > > Patches from 1 to 7, they look good to me. Would it be possible to > apply these patches independently from this batch or they are a strong > dependency? I just pushed them after making sure they don't break any of the testsuites. Fingers crossed I didn't miss a detail which breaks without the other patches. :) > I think it's better if we go slightly different direction? > > https://patchwork.ozlabs.org/project/netfilter-devel/patch/20200723121553.7400-1-pablo@xxxxxxxxxxxxx/ That's interesting. At least it would allow us to reorganize the cache-related data structures, e.g. move the nft_cache->table array items into nft_cache->table items. > Instead of adding more functions into libnftnl for specific list > handling, which are not used by nft, use linux list native handling. OK. > I think there is not need to cache the full nftnl_table object, > probably it should be even possible to just use it to collect the > attributes from the kernel to populate the nft_table object that I'm > proposing. Yes, for iptables-nft at least we should be completely fine with table name alone. > IIRC embedded people complained on the size of libnftnl, going this > direction I suggest, we can probably deprecated iterators for a number > of objects and get it slimmer in the midrun. OK. I'll keep that in mind. So I'll rework my changes based on your nft_table idea and introduce an nft_chain struct to be organized in a standard list_head list. This will allow me to perform the sorting in iptables-nft itself. Should I base this onto your nft_table patch (and exploit it a bit further) or keep them separate for now? Thanks, Phil
