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Merge branch 'tuntap'
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Pavel Emelyanov says:

====================
tun: Some bits required for tun's checkpoint-restore (v2)

After taking a closer look on tun checkpoint-restore I've found several
issues with the tun's API that make it impossible to dump and restore
the state of tun device and attached tun-files.

The proposed API changes are all about extending the existing ioctl-based
stuff. Patches fit today's net-next.

This v2 has David's comments about patch #1 fixed. All the rest is the same.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
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David S. Miller committed Aug 21, 2013
2 parents 5f1cd20 + 76975e9 commit e2748d7
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Showing 2 changed files with 43 additions and 6 deletions.
46 changes: 40 additions & 6 deletions drivers/net/tun.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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 int ifindex;
};
struct list_head next;
struct tun_struct *detached;
};
Expand Down Expand Up @@ -498,7 +501,7 @@ static void tun_detach_all(struct net_device *dev)
module_put(THIS_MODULE);
}

static int tun_attach(struct tun_struct *tun, struct file *file)
static int tun_attach(struct tun_struct *tun, struct file *file, bool skip_filter)
{
struct tun_file *tfile = file->private_data;
int err;
Expand All @@ -523,7 +526,7 @@ static int tun_attach(struct tun_struct *tun, struct file *file)
err = 0;

/* Re-attach the filter to presist device */
if (tun->filter_attached == true) {
if (!skip_filter && (tun->filter_attached == true)) {
err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
if (!err)
goto out;
Expand Down Expand Up @@ -1554,7 +1557,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
if (err < 0)
return err;

err = tun_attach(tun, file);
err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER);
if (err < 0)
return err;

Expand Down Expand Up @@ -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;
Expand All @@ -1627,7 +1631,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
dev->vlan_features = dev->features;

INIT_LIST_HEAD(&tun->disabled);
err = tun_attach(tun, file);
err = tun_attach(tun, file, false);
if (err < 0)
goto err_free_dev;

Expand Down Expand Up @@ -1791,7 +1795,7 @@ static int tun_set_queue(struct file *file, struct ifreq *ifr)
ret = security_tun_dev_attach_queue(tun->security);
if (ret < 0)
goto unlock;
ret = tun_attach(tun, file);
ret = tun_attach(tun, file, false);
} else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
tun = rtnl_dereference(tfile->tun);
if (!tun || !(tun->flags & TUN_TAP_MQ) || tfile->detached)
Expand All @@ -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 int ifindex;
int ret;

if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == 0x89) {
Expand Down Expand Up @@ -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)
Expand All @@ -1863,6 +1881,11 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
case TUNGETIFF:
tun_get_iff(current->nsproxy->net_ns, tun, &ifr);

if (tfile->detached)
ifr.ifr_flags |= IFF_DETACH_QUEUE;
if (!tfile->socket.sk->sk_filter)
ifr.ifr_flags |= IFF_NOFILTER;

if (copy_to_user(argp, &ifr, ifreq_len))
ret = -EFAULT;
break;
Expand Down Expand Up @@ -2019,6 +2042,16 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
tun_detach_filter(tun, tun->numqueues);
break;

case TUNGETFILTER:
ret = -EINVAL;
if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
break;
ret = -EFAULT;
if (copy_to_user(argp, &tun->fprog, sizeof(tun->fprog)))
break;
ret = 0;
break;

default:
ret = -EINVAL;
break;
Expand Down Expand Up @@ -2099,6 +2132,7 @@ 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);
Expand Down
3 changes: 3 additions & 0 deletions include/uapi/linux/if_tun.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -56,6 +56,8 @@
#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)
#define TUNGETFILTER _IOR('T', 219, struct sock_fprog)

/* TUNSETIFF ifr flags */
#define IFF_TUN 0x0001
Expand All @@ -70,6 +72,7 @@
#define IFF_DETACH_QUEUE 0x0400
/* read-only flag */
#define IFF_PERSIST 0x0800
#define IFF_NOFILTER 0x1000

/* Socket options */
#define TUN_TX_TIMESTAMP 1
Expand Down

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