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@xxxxxxxx> I think this should be fixed in the Kconfig rather than inside the module(s). I did some investigation and it turns out that you missed a circumstance. This link error occures only if NFT_SOCKET=y && NF_SOCKET_IPV6=m && NF_TABLES_IPV6=y (cannot be m here if NFT_SOCKET is y). And probably the same with iptables-related modules. Probably this possibility should be eliminated. -- 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