On Thu, Mar 26, 2020 at 07:16:16AM -0700, Maciej Żenczykowski wrote: > I guess maybe we could wrap it in a > > #ifdef BPF_F_RDONLY > attr.file_flags = BPF_F_RDONLY; > #endif > > if we want to continue supporting building against pre-4.15 kernel headers... You can probably add a cached copy of this header file to the iptables tree via your patch like. This is done in other existing extensions to not rely on the available kernel headers. There is no parity between userspace iptables and kernel version, it is good if you make sure this compiles for older kernels are still supported. Thank you.