Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit cde8b15f authored by Jason Wang's avatar Jason Wang Committed by David S. Miller
Browse files

tuntap: add ioctl to attach or detach a file form tuntap device 



Sometimes usespace may need to active/deactive a queue, this could be done by
detaching and attaching a file from tuntap device.

This patch introduces a new ioctls - TUNSETQUEUE which could be used to do
this. Flag IFF_ATTACH_QUEUE were introduced to do attaching while
IFF_DETACH_QUEUE were introduced to do the detaching.

Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c8d68e6b

drivers/net/tun.c

+48 −8
Original line number Diff line number Diff line
@@ -195,6 +195,15 @@ static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb) 
	return txq;

}



static inline bool tun_not_capable(struct tun_struct *tun)

{

	const struct cred *cred = current_cred();



	return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||

		  (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&

		!capable(CAP_NET_ADMIN);

}



static void tun_set_real_num_queues(struct tun_struct *tun)

{

	netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
@@ -1310,8 +1319,6 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) 


	dev = __dev_get_by_name(net, ifr->ifr_name);

	if (dev) {

		const struct cred *cred = current_cred();



		if (ifr->ifr_flags & IFF_TUN_EXCL)

			return -EBUSY;

		if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
@@ -1321,9 +1328,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) 
		else

			return -EINVAL;



		if (((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||

		     (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&

		    !capable(CAP_NET_ADMIN))

		if (tun_not_capable(tun))

			return -EPERM;

		err = security_tun_dev_attach(tfile->socket.sk);

		if (err < 0)
@@ -1530,6 +1535,40 @@ static void tun_set_sndbuf(struct tun_struct *tun) 
	}

}



static int tun_set_queue(struct file *file, struct ifreq *ifr)

{

	struct tun_file *tfile = file->private_data;

	struct tun_struct *tun;

	struct net_device *dev;

	int ret = 0;



	rtnl_lock();



	if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {

		dev = __dev_get_by_name(tfile->net, ifr->ifr_name);

		if (!dev) {

			ret = -EINVAL;

			goto unlock;

		}



		tun = netdev_priv(dev);

		if (dev->netdev_ops != &tap_netdev_ops &&

			dev->netdev_ops != &tun_netdev_ops)

			ret = -EINVAL;

		else if (tun_not_capable(tun))

			ret = -EPERM;

		else

			ret = tun_attach(tun, file);

	} else if (ifr->ifr_flags & IFF_DETACH_QUEUE)

		__tun_detach(tfile, false);

	else

		ret = -EINVAL;



unlock:

	rtnl_unlock();

	return ret;

}



static long __tun_chr_ioctl(struct file *file, unsigned int cmd,

			    unsigned long arg, int ifreq_len)

{
@@ -1543,7 +1582,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd, 
	int vnet_hdr_sz;

	int ret;



	if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89) {

	if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == 0x89) {

		if (copy_from_user(&ifr, argp, ifreq_len))

			return -EFAULT;

	} else {
@@ -1554,9 +1593,10 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd, 
		 * This is needed because we never checked for invalid flags on

		 * TUNSETIFF. */

		return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE |

				IFF_VNET_HDR,

				IFF_VNET_HDR | IFF_MULTI_QUEUE,

				(unsigned int __user*)argp);

	}

	} else if (cmd == TUNSETQUEUE)

		return tun_set_queue(file, &ifr);



	ret = 0;

	rtnl_lock();

include/uapi/linux/if_tun.h

+3 −0
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@ 
#define TUNDETACHFILTER _IOW('T', 214, struct sock_fprog)

#define TUNGETVNETHDRSZ _IOR('T', 215, int)

#define TUNSETVNETHDRSZ _IOW('T', 216, int)

#define TUNSETQUEUE  _IOW('T', 217, int)



/* TUNSETIFF ifr flags */

#define IFF_TUN		0x0001
@@ -63,6 +64,8 @@ 
#define IFF_VNET_HDR	0x4000

#define IFF_TUN_EXCL	0x8000

#define IFF_MULTI_QUEUE 0x0100

#define IFF_ATTACH_QUEUE 0x0200

#define IFF_DETACH_QUEUE 0x0400



/* Features for GSO (TUNSETOFFLOAD). */

#define TUN_F_CSUM	0x01	/* You can hand me unchecksummed packets. */