Re: [PATCH] netfilter: NFT_SOCKET don't use NF_SOCKET_IPV6 without NF_TABLES_IPV6

["Máté Eckl" <ecklm94@gmail.com>]

On Tue, Jul 10, 2018 at 12:56:05PM +0200, Pablo Neira Ayuso wrote:
> On Tue, Jul 10, 2018 at 11:10:40AM +0200, Arnd Bergmann wrote:
> > On Tue, Jul 10, 2018 at 10:05 AM, Máté Eckl <ecklm94@gmail.com> wrote:
> > > On Tue, Jul 10, 2018 at 10:02:27AM +0200, Máté Eckl wrote:
> > >> On Mon, Jul 09, 2018 at 11:35:09PM +0200, Arnd Bergmann wrote:
> > >> > It is now possible to build the nft_socket module as built-in when
> > >> > NF_TABLES_IPV6 is disabled, and have NF_SOCKET_IPV6=m set manually.
> > >> >
> > >> > In this case, the NF_SOCKET_IPV6 functionality will be useless according
> > >> > to the explanation in commit 35bf1ccecaaa ("netfilter: Kconfig: Change
> > >> > IPv6 select dependencies"), but on top of that it also causes a link
> > >> > error:
> > >> >
> > >> > net/netfilter/nft_socket.o: In function `nft_socket_eval':
> > >> > nft_socket.c:(.text+0x162): undefined reference to `nf_sk_lookup_slow_v6'
> > >> >
> > >> > This changes the compile-time check so we don't attempt to use
> > >> > the NF_SOCKET_IPV6 code when it cannot be used, and make it all
> > >> > compile again. That may lead to unexpected behavior when a user
> > >> > enables NF_SOCKET_IPV6 but cannot use it, but seems to be the
> > >> > logical conclusion of the 35bf1ccecaaa change.
> > >> >
> > >> > Fixes: 35bf1ccecaaa ("netfilter: Kconfig: Change IPv6 select dependencies")
> > >> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> > >>
> > >> I think this should be fixed in the Kconfig rather than inside the module(s).
> > 
> > Should we revert your patch then, or do you have a better idea?
> 
> Máté, would you resubmit a new patch that addresses all the problems
> that Arnd is reporting in one go?

This patch only solves the nf_socket and nft_socket modules problem so I can
only submit a v2 for 'netfilter: Kconfig: Change IPv6 select dependencies' but
you already applied it so it would meen a force push. Should I do this?

I think Arnd's patch solves these problems in case we don't want to force-push
or rebase.

> I think it's better if we toss your original patch in the tree and
> rebase, ie. take the new one that fixes all issues that Arnd is
> reporting. It would be good if we can sort out this before I send the
> next pull request for net-next stuff.
> 
> I was afraid of fallout like this when I saw your original patch,
> kbuild is always tricky.

This patch is not related to the nft_tproxy module (it seems that you refer to
that) as Arnd didn't have that in the tree when doing this. I'll send a v4 fot
the tproxy module, but that cannot be related to this one as it is not in tree
yet.

> Please Cc Arnd, Florian and me for review.
> 
> Thanks!