From fb7589a162162223e6bb6422dde3fb1ce07d9a78 Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Wed, 21 Aug 2013 14:31:38 +0400 Subject: tun: Add ability to create tun device with given index Tun devices cannot be created with ifidex user wants, but it's required by checkpoint-restore project. Long time ago such ability was implemented for rtnl_ops-based interface for creating links (9c7dafbf net: Allow to create links with given ifindex), but the only API for creating and managing tuntap devices is ioctl-based and is evolving with adding new ones (cde8b15f tuntap: add ioctl to attach or detach a file form tuntap device). Following that trend, here's how a new ioctl that sets the ifindex for device, that _will_ be created by TUNSETIFF ioctl looks like. So those who want a tuntap device with the ifindex N, should open the tun device, call ioctl(fd, TUNSETIFINDEX, &N), then call TUNSETIFF. If the index N is busy, then the register_netdev will find this out and the ioctl would be failed with -EBUSY. If setifindex is not called, then it will be generated as before. Signed-off-by: Pavel Emelyanov Signed-off-by: David S. Miller --- include/uapi/linux/if_tun.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/uapi') diff --git a/include/uapi/linux/if_tun.h b/include/uapi/linux/if_tun.h index 1870ee2..c58d023 100644 --- a/include/uapi/linux/if_tun.h +++ b/include/uapi/linux/if_tun.h @@ -56,6 +56,7 @@ #define TUNGETVNETHDRSZ _IOR('T', 215, int) #define TUNSETVNETHDRSZ _IOW('T', 216, int) #define TUNSETQUEUE _IOW('T', 217, int) +#define TUNSETIFINDEX _IOW('T', 218, unsigned int) /* TUNSETIFF ifr flags */ #define IFF_TUN 0x0001 -- cgit v1.1