ioctl (TUNSETIFF) : device or resource busy
<p>I am unable to set TUN interface. Everywhere i searched and it says the device should be rooted.
I am setting up proxyserver on my ubuntu 14.04 system </p>

<pre><code>static int get_interface(char *name) {
int interface = open("/dev/net/tun", O_RDWR | O_NONBLOCK);
struct ifreq ifr;
memset(&amp;ifr, 0, sizeof(ifr));
ifr.ifr_flags = IFF_TUN | IFF_NO_PI;   
strncpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));

if (ioctl(interface, TUNSETIFF, (void *)&amp;ifr) &lt; 0) {
    perror("Cannot get TUN interface");
    exit(1);
}

return interface;
</code></pre>

<p>}</p>