diff options
| -rw-r--r-- | drivers/net/tun.c | 48 |
1 files changed, 32 insertions, 16 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 17923a5..20ef14d 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -106,6 +106,31 @@ struct tun_struct { #endif }; +static int tun_attach(struct tun_struct *tun, struct file *file) +{ + const struct cred *cred = current_cred(); + + ASSERT_RTNL(); + + if (file->private_data) + return -EINVAL; + + if (tun->attached) + return -EBUSY; + + /* Check permissions */ + if (((tun->owner != -1 && cred->euid != tun->owner) || + (tun->group != -1 && cred->egid != tun->group)) && + !capable(CAP_NET_ADMIN)) + return -EPERM; + + file->private_data = tun; + tun->attached = 1; + get_net(dev_net(tun->dev)); + + return 0; +} + /* TAP filterting */ static void addr_hash_set(u32 *mask, const u8 *addr) { @@ -695,7 +720,6 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) { struct tun_struct *tun; struct net_device *dev; - const struct cred *cred = current_cred(); int err; dev = __dev_get_by_name(net, ifr->ifr_name); @@ -707,17 +731,9 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) else return -EINVAL; - if (tun->attached) - return -EBUSY; - - /* Check permissions */ - if (((tun->owner != -1 && - cred->euid != tun->owner) || - (tun->group != -1 && - cred->egid != tun->group)) && - !capable(CAP_NET_ADMIN)) { - return -EPERM; - } + err = tun_attach(tun, file); + if (err < 0) + return err; } else { char *name; @@ -766,6 +782,10 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) err = register_netdevice(tun->dev); if (err < 0) goto err_free_dev; + + err = tun_attach(tun, file); + if (err < 0) + goto err_free_dev; } DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name); @@ -785,10 +805,6 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) else tun->flags &= ~TUN_VNET_HDR; - file->private_data = tun; - tun->attached = 1; - get_net(dev_net(tun->dev)); - /* Make sure persistent devices do not get stuck in * xoff state. */ |
