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Diffstat (limited to 'drivers/net')
-rw-r--r--drivers/net/tun.c156
1 files changed, 104 insertions, 52 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 8743de9d2572..d3a665d2f7b8 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -87,9 +87,13 @@ struct tap_filter {
unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
};
+struct tun_file {
+ struct tun_struct *tun;
+};
+
struct tun_struct {
+ struct tun_file *tfile;
unsigned int flags;
- int attached;
uid_t owner;
gid_t group;
@@ -108,14 +112,15 @@ struct tun_struct {
static int tun_attach(struct tun_struct *tun, struct file *file)
{
+ struct tun_file *tfile = file->private_data;
const struct cred *cred = current_cred();
ASSERT_RTNL();
- if (file->private_data)
+ if (tfile->tun)
return -EINVAL;
- if (tun->attached)
+ if (tun->tfile)
return -EBUSY;
/* Check permissions */
@@ -124,13 +129,41 @@ static int tun_attach(struct tun_struct *tun, struct file *file)
!capable(CAP_NET_ADMIN))
return -EPERM;
- file->private_data = tun;
- tun->attached = 1;
+ tfile->tun = tun;
+ tun->tfile = tfile;
get_net(dev_net(tun->dev));
return 0;
}
+static void __tun_detach(struct tun_struct *tun)
+{
+ struct tun_file *tfile = tun->tfile;
+
+ /* Detach from net device */
+ tfile->tun = NULL;
+ tun->tfile = NULL;
+ put_net(dev_net(tun->dev));
+
+ /* Drop read queue */
+ skb_queue_purge(&tun->readq);
+}
+
+static struct tun_struct *__tun_get(struct tun_file *tfile)
+{
+ return tfile->tun;
+}
+
+static struct tun_struct *tun_get(struct file *file)
+{
+ return __tun_get(file->private_data);
+}
+
+static void tun_put(struct tun_struct *tun)
+{
+ /* Noop for now */
+}
+
/* TAP filterting */
static void addr_hash_set(u32 *mask, const u8 *addr)
{
@@ -261,7 +294,7 @@ static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->dev->name, skb->len);
/* Drop packet if interface is not attached */
- if (!tun->attached)
+ if (!tun->tfile)
goto drop;
/* Drop if the filter does not like it.
@@ -378,7 +411,7 @@ static void tun_net_init(struct net_device *dev)
/* Poll */
static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
{
- struct tun_struct *tun = file->private_data;
+ struct tun_struct *tun = tun_get(file);
unsigned int mask = POLLOUT | POLLWRNORM;
if (!tun)
@@ -391,6 +424,7 @@ static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
if (!skb_queue_empty(&tun->readq))
mask |= POLLIN | POLLRDNORM;
+ tun_put(tun);
return mask;
}
@@ -575,14 +609,18 @@ static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv,
static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
unsigned long count, loff_t pos)
{
- struct tun_struct *tun = iocb->ki_filp->private_data;
+ struct tun_struct *tun = tun_get(iocb->ki_filp);
+ ssize_t result;
if (!tun)
return -EBADFD;
DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
- return tun_get_user(tun, (struct iovec *) iv, iov_length(iv, count));
+ result = tun_get_user(tun, (struct iovec *) iv, iov_length(iv, count));
+
+ tun_put(tun);
+ return result;
}
/* Put packet to the user space buffer */
@@ -655,7 +693,7 @@ static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
unsigned long count, loff_t pos)
{
struct file *file = iocb->ki_filp;
- struct tun_struct *tun = file->private_data;
+ struct tun_struct *tun = tun_get(file);
DECLARE_WAITQUEUE(wait, current);
struct sk_buff *skb;
ssize_t len, ret = 0;
@@ -666,8 +704,10 @@ static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
len = iov_length(iv, count);
- if (len < 0)
- return -EINVAL;
+ if (len < 0) {
+ ret = -EINVAL;
+ goto out;
+ }
add_wait_queue(&tun->read_wait, &wait);
while (len) {
@@ -698,6 +738,8 @@ static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
current->state = TASK_RUNNING;
remove_wait_queue(&tun->read_wait, &wait);
+out:
+ tun_put(tun);
return ret;
}
@@ -822,7 +864,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
static int tun_get_iff(struct net *net, struct file *file, struct ifreq *ifr)
{
- struct tun_struct *tun = file->private_data;
+ struct tun_struct *tun = tun_get(file);
if (!tun)
return -EBADFD;
@@ -847,6 +889,7 @@ static int tun_get_iff(struct net *net, struct file *file, struct ifreq *ifr)
if (tun->flags & TUN_VNET_HDR)
ifr->ifr_flags |= IFF_VNET_HDR;
+ tun_put(tun);
return 0;
}
@@ -893,7 +936,7 @@ static int set_offload(struct net_device *dev, unsigned long arg)
static int tun_chr_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
- struct tun_struct *tun = file->private_data;
+ struct tun_struct *tun;
void __user* argp = (void __user*)arg;
struct ifreq ifr;
int ret;
@@ -902,6 +945,16 @@ static int tun_chr_ioctl(struct inode *inode, struct file *file,
if (copy_from_user(&ifr, argp, sizeof ifr))
return -EFAULT;
+ if (cmd == TUNGETFEATURES) {
+ /* Currently this just means: "what IFF flags are valid?".
+ * 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,
+ (unsigned int __user*)argp);
+ }
+
+ tun = tun_get(file);
if (cmd == TUNSETIFF && !tun) {
int err;
@@ -919,28 +972,21 @@ static int tun_chr_ioctl(struct inode *inode, struct file *file,
return 0;
}
- if (cmd == TUNGETFEATURES) {
- /* Currently this just means: "what IFF flags are valid?".
- * 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,
- (unsigned int __user*)argp);
- }
if (!tun)
return -EBADFD;
DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->dev->name, cmd);
+ ret = 0;
switch (cmd) {
case TUNGETIFF:
ret = tun_get_iff(current->nsproxy->net_ns, file, &ifr);
if (ret)
- return ret;
+ break;
if (copy_to_user(argp, &ifr, sizeof(ifr)))
- return -EFAULT;
+ ret = -EFAULT;
break;
case TUNSETNOCSUM:
@@ -992,7 +1038,7 @@ static int tun_chr_ioctl(struct inode *inode, struct file *file,
ret = 0;
}
rtnl_unlock();
- return ret;
+ break;
#ifdef TUN_DEBUG
case TUNSETDEBUG:
@@ -1003,24 +1049,25 @@ static int tun_chr_ioctl(struct inode *inode, struct file *file,
rtnl_lock();
ret = set_offload(tun->dev, arg);
rtnl_unlock();
- return ret;
+ break;
case TUNSETTXFILTER:
/* Can be set only for TAPs */
+ ret = -EINVAL;
if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV)
- return -EINVAL;
+ break;
rtnl_lock();
ret = update_filter(&tun->txflt, (void __user *)arg);
rtnl_unlock();
- return ret;
+ break;
case SIOCGIFHWADDR:
/* Get hw addres */
memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
ifr.ifr_hwaddr.sa_family = tun->dev->type;
if (copy_to_user(argp, &ifr, sizeof ifr))
- return -EFAULT;
- return 0;
+ ret = -EFAULT;
+ break;
case SIOCSIFHWADDR:
/* Set hw address */
@@ -1030,18 +1077,19 @@ static int tun_chr_ioctl(struct inode *inode, struct file *file,
rtnl_lock();
ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
rtnl_unlock();
- return ret;
-
+ break;
default:
- return -EINVAL;
+ ret = -EINVAL;
+ break;
};
- return 0;
+ tun_put(tun);
+ return ret;
}
static int tun_chr_fasync(int fd, struct file *file, int on)
{
- struct tun_struct *tun = file->private_data;
+ struct tun_struct *tun = tun_get(file);
int ret;
if (!tun)
@@ -1063,40 +1111,44 @@ static int tun_chr_fasync(int fd, struct file *file, int on)
ret = 0;
out:
unlock_kernel();
+ tun_put(tun);
return ret;
}
static int tun_chr_open(struct inode *inode, struct file * file)
{
+ struct tun_file *tfile;
cycle_kernel_lock();
DBG1(KERN_INFO "tunX: tun_chr_open\n");
- file->private_data = NULL;
+
+ tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
+ if (!tfile)
+ return -ENOMEM;
+ tfile->tun = NULL;
+ file->private_data = tfile;
return 0;
}
static int tun_chr_close(struct inode *inode, struct file *file)
{
- struct tun_struct *tun = file->private_data;
-
- if (!tun)
- return 0;
+ struct tun_file *tfile = file->private_data;
+ struct tun_struct *tun = __tun_get(tfile);
- DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
- rtnl_lock();
+ if (tun) {
+ DBG(KERN_INFO "%s: tun_chr_close\n", tun->dev->name);
- /* Detach from net device */
- file->private_data = NULL;
- tun->attached = 0;
- put_net(dev_net(tun->dev));
+ rtnl_lock();
+ __tun_detach(tun);
- /* Drop read queue */
- skb_queue_purge(&tun->readq);
+ /* If desireable, unregister the netdevice. */
+ if (!(tun->flags & TUN_PERSIST))
+ unregister_netdevice(tun->dev);
- if (!(tun->flags & TUN_PERSIST))
- unregister_netdevice(tun->dev);
+ rtnl_unlock();
+ }
- rtnl_unlock();
+ kfree(tfile);
return 0;
}
@@ -1177,7 +1229,7 @@ static void tun_set_msglevel(struct net_device *dev, u32 value)
static u32 tun_get_link(struct net_device *dev)
{
struct tun_struct *tun = netdev_priv(dev);
- return tun->attached;
+ return !!tun->tfile;
}
static u32 tun_get_rx_csum(struct net_device *dev)
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.