Bringing down ethernet

[Charles Steaderman]

Is there a simple function for bringing down and ethernet port? I tried 
using something like:

short flags = ~IFF_UP;
rtems_bsdnet_ifconfig ("eth0", SIOCGIFFLAGS, &flags);

but when I traced throught the rtems_bsdnet_ifconfig source it appears 
that you can only ADD flags, but never DELETE them. Is this correct? I 
ended up copying a source snippet from rtems_bsdnet_ifconfig which looks 
as follows:

int ifDown(const char* sIfName)
{
   int           status = 0;
   int           s, r = 0;
   struct ifreq  ifreq;

   s = socket (AF_INET, SOCK_DGRAM, 0);
   if (s < 0)
       return(-1);

   strncpy (ifreq.ifr_name, sIfName, IFNAMSIZ);

   rtems_bsdnet_semaphore_obtain ();

   if ((r = ioctl (s, SIOCGIFFLAGS, &ifreq)) < 0)
           status = -1;

   if(status == 0)
   {
       ifreq.ifr_flags &= ~IFF_UP;
       r = ioctl (s, SIOCSIFFLAGS, &ifreq);
   }

   rtems_bsdnet_semaphore_release ();

   close (s);
     return status;
}

but I didn't like having to expose myself to such low level code. Any 
comments would be appreciated.

- Charlie