[klibc] Allow ipconfig to bring down interfaces

[Karl O. Pinc]

On 07/09/2013 10:53:15 AM, Karl O. Pinc wrote:
> On 07/09/2013 09:27:58 AM, Karl O. Pinc wrote:
> 
> > Attached and on the "ipconfig_down" branch at github
> > (https://github.com/kpinc/klibc.git) you will find 4 patches
> > which let ipconfig bring down interfaces.  Please consider
> > them for inclusion.

There's a bug.  Setting the down socket flag with ioctl
via the netdev_down call brings the interface down
but is not enough to de-configure
the interface.  The system still responds to the initramfs's
IP after a new IP is brought up, at least with linux 3.2.0.

(But the initramfs's IP does not show in ifconfig.  I'll
investigate further with ip.)

Help figuring out what needs to be done with the kernel's
socket ioctl calls is appreciated.  Near as I can tell
from the kernel's code the IFF_DYNAMIC flag is not useful....
I can poke the ioctls with a stick but I'd rather
understand the model and do the right thing and I'm not
sure where to look to understand this.

Regards,

Karl <kop at meme.com>
Free Software:  "You don't pay back, you pay forward."
                 -- Robert A. Heinlein