[systemd-devel] [PATCH 1/3] sd-rtnl: Always enable IFA_FLAGS

[Alexander Sverdlin]

Hi!

On 07/04/15 20:49, Lennart Poettering wrote:
>>>>>> IFA_FLAGS seems to appear in kernel ~3.13 and the kernel requirements
>>>>>>>>> > >>>> >> > from README state 3.8/3.7 at the moment.
>>>>>>>>> > >>>> >> > 
>>>>>>>>> > >>>> >> > One could let the sd_rtnl_message_append_u32 for IFA_FLAGS fail in patch
>>>>>>>>> > >>>> >> > 2/3, but then user space has to play tricks with IPv6 DHCPv6 routes as
>>>>>>>>> > >>>> >> > before this patch and needs to re-add the code just removed because of
>>>>>>>>> > >>>> >> > this nice feature. Oh well...
>>>>> > >> > I'm building against 3.19 at the moment. Just had no chance to check what's
>>> > > Oh, sorry, the headers are from 3.12, but that's still newer than 3.8 in the doc...
>>> > > 
>>>>> > >> > actually wrong, but your patch actually brakes compilation for me. Toolchain
>>>>> > >> > is gcc 4.9 custombuilt from buildroot.
>> > 
>> > Got it, we just need documentation update or fallback define as Lennart proposed :)
> We usually try to support the kernels from the last two years in
> systemd. That means 3.8 or 3.9 or so., right now. 
> 
> Hence we really should add the fallback define to missing.h.

But if the backend code for this flag appears first in Linux 3.14
(https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=479840ffdbe4),
working around the compilation issue (against older uapi headers) will not help with
the fact that networkd will fail in 851c9f82736 (systemd-networkd: Use IFA_F_NOPREFIXROUTE with IPv6 addresses)?

Alex.