On Wed, 26 Sep 2018 08:54:43 -0600 David Ahern <dsah...@gmail.com> wrote:
> On 9/25/18 11:51 PM, Jiri Benc wrote: > > On Tue, 25 Sep 2018 09:37:41 -0600, David Ahern wrote: > >> For ifaddrmsg ifa_flags aligns with ifi_type which is set by kernel side > >> so this should be ok. > > > > Does the existing user space set ifi_type to anything? Does it zero out > > the field? > > > > Are we able to find a flag value that is not going to be set by unaware > > user space? I.e., a bit that is unused by the current ARPHRD values on > > both little and big endian? (ARPHRD_NONE might be a problem, though...) > > The goal is for userpsace to pass something to the kernel to > definitively state which header is used. > You can not safely assume anything about older code. iproute2 is not the only thing using the API, others include Quagga, and other tools. Sorry, this API is frozen.
