@@ -138,7 +138,10 @@ struct tun_file {
struct fasync_struct *fasync;
/* only used for fasnyc */
unsigned int flags;
- u16 queue_index;
+ union {
+ u16 queue_index;
+ unsigned ifindex;
+ };
struct list_head next;
struct tun_struct *detached;
};
@@ -1601,6 +1604,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
dev_net_set(dev, net);
dev->rtnl_link_ops = &tun_link_ops;
+ dev->ifindex = tfile->ifindex;
tun = netdev_priv(dev);
tun->dev = dev;
@@ -1817,6 +1821,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
kgid_t group;
int sndbuf;
int vnet_hdr_sz;
+ unsigned ifindex;
int ret;
if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == 0x89) {
@@ -1851,6 +1856,19 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
ret = -EFAULT;
goto unlock;
}
+ if (cmd == TUNSETIFINDEX) {
+ ret = -EPERM;
+ if (tun)
+ goto unlock;
+
+ ret = -EFAULT;
+ if (copy_from_user(&ifindex, argp, sizeof(ifindex)))
+ goto unlock;
+
+ ret = 0;
+ tfile->ifindex = ifindex;
+ goto unlock;
+ }
ret = -EBADFD;
if (!tun)
@@ -2099,6 +2117,7 @@ static int tun_chr_open(struct inode *inode, struct file * file)
rcu_assign_pointer(tfile->tun, NULL);
tfile->net = get_net(current->nsproxy->net_ns);
tfile->flags = 0;
+ tfile->ifindex = 0;
rcu_assign_pointer(tfile->socket.wq, &tfile->wq);
init_waitqueue_head(&tfile->wq.wait);
@@ -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
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 <xemul@parallels.com> --- drivers/net/tun.c | 21 ++++++++++++++++++++- include/uapi/linux/if_tun.h | 1 + 2 files changed, 21 insertions(+), 1 deletions(-)