Re: RFC: configuring net interfaces

[Francois Romieu <romieu@cogenit.fr>]

Krzysztof Halasa <khc@intrepid.pm.waw.pl> écrit :
[...]
> > Comments welcome.  IMHO domain-specific ioctls are a better direction
> > than the current make-sockios.h-huge-with-new-ioctls approach.
> 
> I think we should separate two things there:
> - the place (files) where SIOCxxx values are defined
> - the way we use ioctl call.

(1) and (2) may be related: 
no sub-ioctl (2) + scattered files (1) = *ouch*

[...]
> you have to call it with:
>         proto = malloc();
>         ifreq.name = "qwe0";
>         ifreq.data = proto;
>         (int*)proto = SIOC_SET_FR_PROTO_PARAMETERS;
>         (fr_protocol)(((int*)proto) + 1).fr_protocol.t391 = 20;
>         (fr_protocol)(((int*)proto) + 1).fr_protocol.n393 = 5;
>         ioctl(s, SIOC_FR_PROTO, &ifreq);

Variant:
	struct sub_req sub;

	sub.fr_protocol.t391 = 20;
	sub.fr_protocol.n293 = 5;
	sub.sub_ioctl = SIOC_SET_FR_PROTO_PARAMETERS;
	ifreq.name = "qwe0";
	ifreq.data = &sub;
	ioctl(s, SIOC_FR_PROTO, &ifreq);

At least it avoids digging at a special position in a structure 
to know the expected operation and the underlying structure.

struc sub_req {
	int sub_ioctl;
	union {
		struct fr_protocol fr_prot;
		...
		struct xx_protocol xx_prot;
	}
}

struct if_req {
	int name;

	struct sub_req sub;
}

It could avoid a flat name-space. Opinion anyone ?

-- 
Ueimor