195624d9c2
This change adds support for not enabling carrier during TUNSETIFF interface creation by specifying the IFF_NO_CARRIER flag. Our tests make heavy use of tun interfaces. In some scenarios, the test process creates the interface but another process brings it up after the interface is discovered via netlink notification. In that case, it is not possible to create a tun/tap interface with carrier off without it racing against the bring up. Immediately setting carrier off via TUNSETCARRIER is still too late. Signed-off-by: Patrick Rohr <prohr@google.com> Cc: Maciej Żenczykowski <maze@google.com> Cc: Lorenzo Colitti <lorenzo@google.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Stephen Hemminger <stephen@networkplumber.org> Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com> Reviewed-by: Maciej Żenczykowski <maze@google.com> Acked-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>