in tunopen())
o Change the default device permissions to 0600 root:wheel
(were uucp:dialer)
o Only let root (suser()) change the MTU
This makes it possible for an administrator to open up the
permissions on /dev/tun*, letting non-root programs service
a tun interface. Co-operation is still required with a
priviledged program that will configure the interface side
of things.
8e5db7b9b7