Re: [PATCH nftables] include: fix for musl with iptables v1.8.11

[Phil Sutter <phil@nwl.cc>]

On Wed, Feb 11, 2026 at 02:49:42PM +0100, Florian Westphal wrote:
> Phil Sutter <phil@nwl.cc> wrote:
> > On Thu, Jan 09, 2025 at 01:03:25AM +0100, Pablo Neira Ayuso wrote:
> > > Hm. I am looking at include/uapi/linux/netfilter_bridge.h and...
> > > 
> > > #include <linux/in.h>
> > > #include <linux/netfilter.h>
> > > #include <linux/if_ether.h>
> > > #include <linux/if_vlan.h>
> > > #include <linux/if_pppox.h>
> > > 
> > > I don't understand why all those #include need to be there, this
> > > header file contains only defines an enumeration... git annotate takes
> > > me to:
> > > 
> > >   607ca46e97a1 ("UAPI: (Scripted) Disintegrate include/linux")
> > > 
> > > Silly question: Does it break any netfilter userspace software if
> > > #include <linux/if_ether.h> is moved from that kernel header file to
> > > to the non-uapi netfilter_bridge.h header file.
> > 
> > Silly counter question: Does removing an include statement break UAPI?
> 
> Yes, it risks uapi breakage.

I hope this extra include is safe in that regard.

> > BTW: I see only a single UAPI kernel header include from netinet space
> > (include/uapi/linux/mptcp.h) and it's for compat reasons (06e445f740c1
> > ("mptcp: fix conflict with <netinet/in.h>")). Speaking of which, what if
> > we added:
> > 
> > | #ifndef __KERNEL__
> > | #include <netinet/if_ether.h>
> > | #endif
> > 
> > early into include/uapi/linux/if_ether.h? Aside from any header caches,
> > this should fix all of user space at once, no?
> 
> Phil, would you send a formal patch to make this workaround *ONLY* in
> netfilter_bridge.h (06e445f740c1)?

DONE.

> That way the fix can be propagated to nftables.git without having to
> adjust cached headers on every update.

I assume you prefer to keep headers untouched which are
iptables-specific. But why not attempt to patch if_ether.h itself?

Cheers, Phil