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path: root/drivers/net/tun.c
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Diffstat (limited to 'drivers/net/tun.c')
-rw-r--r--drivers/net/tun.c373
1 files changed, 229 insertions, 144 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index d7b81e4fdd5..15d67635bb1 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -63,6 +63,7 @@
#include <linux/virtio_net.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
+#include <net/rtnetlink.h>
#include <asm/system.h>
#include <asm/uaccess.h>
@@ -87,14 +88,19 @@ struct tap_filter {
unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
};
+struct tun_file {
+ atomic_t count;
+ struct tun_struct *tun;
+ struct net *net;
+ wait_queue_head_t read_wait;
+};
+
struct tun_struct {
- struct list_head list;
+ struct tun_file *tfile;
unsigned int flags;
- int attached;
uid_t owner;
gid_t group;
- wait_queue_head_t read_wait;
struct sk_buff_head readq;
struct net_device *dev;
@@ -107,6 +113,88 @@ struct tun_struct {
#endif
};
+static int tun_attach(struct tun_struct *tun, struct file *file)
+{
+ struct tun_file *tfile = file->private_data;
+ const struct cred *cred = current_cred();
+ int err;
+
+ ASSERT_RTNL();
+
+ /* Check permissions */
+ if (((tun->owner != -1 && cred->euid != tun->owner) ||
+ (tun->group != -1 && !in_egroup_p(tun->group))) &&
+ !capable(CAP_NET_ADMIN))
+ return -EPERM;
+
+ netif_tx_lock_bh(tun->dev);
+
+ err = -EINVAL;
+ if (tfile->tun)
+ goto out;
+
+ err = -EBUSY;
+ if (tun->tfile)
+ goto out;
+
+ err = 0;
+ tfile->tun = tun;
+ tun->tfile = tfile;
+ dev_hold(tun->dev);
+ atomic_inc(&tfile->count);
+
+out:
+ netif_tx_unlock_bh(tun->dev);
+ return err;
+}
+
+static void __tun_detach(struct tun_struct *tun)
+{
+ struct tun_file *tfile = tun->tfile;
+
+ /* Detach from net device */
+ netif_tx_lock_bh(tun->dev);
+ tfile->tun = NULL;
+ tun->tfile = NULL;
+ netif_tx_unlock_bh(tun->dev);
+
+ /* Drop read queue */
+ skb_queue_purge(&tun->readq);
+
+ /* Drop the extra count on the net device */
+ dev_put(tun->dev);
+}
+
+static void tun_detach(struct tun_struct *tun)
+{
+ rtnl_lock();
+ __tun_detach(tun);
+ rtnl_unlock();
+}
+
+static struct tun_struct *__tun_get(struct tun_file *tfile)
+{
+ struct tun_struct *tun = NULL;
+
+ if (atomic_inc_not_zero(&tfile->count))
+ tun = tfile->tun;
+
+ return tun;
+}
+
+static struct tun_struct *tun_get(struct file *file)
+{
+ return __tun_get(file->private_data);
+}
+
+static void tun_put(struct tun_struct *tun)
+{
+ struct tun_file *tfile = tun->tfile;
+
+ if (atomic_dec_and_test(&tfile->count))
+ tun_detach(tfile->tun);
+}
+
/* TAP filterting */
static void addr_hash_set(u32 *mask, const u8 *addr)
{
@@ -213,13 +301,23 @@ static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
/* Network device part of the driver */
-static int tun_net_id;
-struct tun_net {
- struct list_head dev_list;
-};
-
static const struct ethtool_ops tun_ethtool_ops;
+/* Net device detach from fd. */
+static void tun_net_uninit(struct net_device *dev)
+{
+ struct tun_struct *tun = netdev_priv(dev);
+ struct tun_file *tfile = tun->tfile;
+
+ /* Inform the methods they need to stop using the dev.
+ */
+ if (tfile) {
+ wake_up_all(&tfile->read_wait);
+ if (atomic_dec_and_test(&tfile->count))
+ __tun_detach(tun);
+ }
+}
+
/* Net device open. */
static int tun_net_open(struct net_device *dev)
{
@@ -242,7 +340,7 @@ 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.
@@ -274,7 +372,7 @@ static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
/* Notify and wake up reader process */
if (tun->flags & TUN_FASYNC)
kill_fasync(&tun->fasync, SIGIO, POLL_IN);
- wake_up_interruptible(&tun->read_wait);
+ wake_up_interruptible(&tun->tfile->read_wait);
return 0;
drop:
@@ -306,6 +404,7 @@ tun_net_change_mtu(struct net_device *dev, int new_mtu)
}
static const struct net_device_ops tun_netdev_ops = {
+ .ndo_uninit = tun_net_uninit,
.ndo_open = tun_net_open,
.ndo_stop = tun_net_close,
.ndo_start_xmit = tun_net_xmit,
@@ -313,6 +412,7 @@ static const struct net_device_ops tun_netdev_ops = {
};
static const struct net_device_ops tap_netdev_ops = {
+ .ndo_uninit = tun_net_uninit,
.ndo_open = tun_net_open,
.ndo_stop = tun_net_close,
.ndo_start_xmit = tun_net_xmit,
@@ -359,19 +459,24 @@ 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_file *tfile = file->private_data;
+ struct tun_struct *tun = __tun_get(tfile);
unsigned int mask = POLLOUT | POLLWRNORM;
if (!tun)
- return -EBADFD;
+ return POLLERR;
DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
- poll_wait(file, &tun->read_wait, wait);
+ poll_wait(file, &tfile->read_wait, wait);
if (!skb_queue_empty(&tun->readq))
mask |= POLLIN | POLLRDNORM;
+ if (tun->dev->reg_state != NETREG_REGISTERED)
+ mask = POLLERR;
+
+ tun_put(tun);
return mask;
}
@@ -438,7 +543,7 @@ static struct sk_buff *tun_alloc_skb(size_t prepad, size_t len, size_t linear,
/* Get packet from user space buffer */
static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
{
- struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
+ struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
struct sk_buff *skb;
size_t len = count, align = 0;
struct virtio_net_hdr gso = { 0 };
@@ -556,14 +661,18 @@ 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 */
@@ -636,7 +745,8 @@ 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_file *tfile = file->private_data;
+ struct tun_struct *tun = __tun_get(tfile);
DECLARE_WAITQUEUE(wait, current);
struct sk_buff *skb;
ssize_t len, ret = 0;
@@ -647,10 +757,12 @@ 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);
+ add_wait_queue(&tfile->read_wait, &wait);
while (len) {
current->state = TASK_INTERRUPTIBLE;
@@ -664,6 +776,10 @@ static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv,
ret = -ERESTARTSYS;
break;
}
+ if (tun->dev->reg_state != NETREG_REGISTERED) {
+ ret = -EIO;
+ break;
+ }
/* Nothing to read, let's sleep */
schedule();
@@ -677,8 +793,10 @@ 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);
+ remove_wait_queue(&tfile->read_wait, &wait);
+out:
+ tun_put(tun);
return ret;
}
@@ -687,54 +805,49 @@ static void tun_setup(struct net_device *dev)
struct tun_struct *tun = netdev_priv(dev);
skb_queue_head_init(&tun->readq);
- init_waitqueue_head(&tun->read_wait);
tun->owner = -1;
tun->group = -1;
dev->ethtool_ops = &tun_ethtool_ops;
dev->destructor = free_netdev;
- dev->features |= NETIF_F_NETNS_LOCAL;
}
-static struct tun_struct *tun_get_by_name(struct tun_net *tn, const char *name)
+/* Trivial set of netlink ops to allow deleting tun or tap
+ * device with netlink.
+ */
+static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
{
- struct tun_struct *tun;
+ return -EINVAL;
+}
- ASSERT_RTNL();
- list_for_each_entry(tun, &tn->dev_list, list) {
- if (!strncmp(tun->dev->name, name, IFNAMSIZ))
- return tun;
- }
+static struct rtnl_link_ops tun_link_ops __read_mostly = {
+ .kind = DRV_NAME,
+ .priv_size = sizeof(struct tun_struct),
+ .setup = tun_setup,
+ .validate = tun_validate,
+};
- return NULL;
-}
static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
{
- struct tun_net *tn;
struct tun_struct *tun;
struct net_device *dev;
- const struct cred *cred = current_cred();
int err;
- tn = net_generic(net, tun_net_id);
- tun = tun_get_by_name(tn, ifr->ifr_name);
- if (tun) {
- 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;
- }
+ dev = __dev_get_by_name(net, ifr->ifr_name);
+ if (dev) {
+ if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
+ tun = netdev_priv(dev);
+ else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
+ tun = netdev_priv(dev);
+ else
+ return -EINVAL;
+
+ err = tun_attach(tun, file);
+ if (err < 0)
+ return err;
}
- else if (__dev_get_by_name(net, ifr->ifr_name))
- return -EINVAL;
else {
char *name;
unsigned long flags = 0;
@@ -765,6 +878,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
return -ENOMEM;
dev_net_set(dev, net);
+ dev->rtnl_link_ops = &tun_link_ops;
tun = netdev_priv(dev);
tun->dev = dev;
@@ -783,7 +897,9 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
if (err < 0)
goto err_free_dev;
- list_add(&tun->list, &tn->dev_list);
+ err = tun_attach(tun, file);
+ if (err < 0)
+ goto err_free_dev;
}
DBG(KERN_INFO "%s: tun_set_iff\n", tun->dev->name);
@@ -803,10 +919,6 @@ 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.
*/
@@ -824,7 +936,7 @@ 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;
@@ -849,6 +961,7 @@ 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;
}
@@ -895,7 +1008,8 @@ 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_file *tfile = file->private_data;
+ struct tun_struct *tun;
void __user* argp = (void __user*)arg;
struct ifreq ifr;
int ret;
@@ -904,13 +1018,23 @@ 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(tfile);
if (cmd == TUNSETIFF && !tun) {
int err;
ifr.ifr_name[IFNAMSIZ-1] = '\0';
rtnl_lock();
- err = tun_set_iff(current->nsproxy->net_ns, file, &ifr);
+ err = tun_set_iff(tfile->net, file, &ifr);
rtnl_unlock();
if (err)
@@ -921,28 +1045,21 @@ 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:
@@ -994,7 +1111,7 @@ static int tun_chr_ioctl(struct inode *inode, struct file *file,
ret = 0;
}
rtnl_unlock();
- return ret;
+ break;
#ifdef TUN_DEBUG
case TUNSETDEBUG:
@@ -1005,24 +1122,25 @@ 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 */
@@ -1032,18 +1150,19 @@ 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)
@@ -1065,42 +1184,48 @@ 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;
+ atomic_set(&tfile->count, 0);
+ tfile->tun = NULL;
+ tfile->net = get_net(current->nsproxy->net_ns);
+ init_waitqueue_head(&tfile->read_wait);
+ file->private_data = tfile;
return 0;
}
static int tun_chr_close(struct inode *inode, struct file *file)
{
- struct tun_struct *tun = file->private_data;
+ struct tun_file *tfile = file->private_data;
+ struct tun_struct *tun = __tun_get(tfile);
- if (!tun)
- return 0;
-
- 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)) {
- list_del(&tun->list);
- unregister_netdevice(tun->dev);
+ rtnl_unlock();
}
- rtnl_unlock();
+ put_net(tfile->net);
+ kfree(tfile);
return 0;
}
@@ -1181,7 +1306,7 @@ 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)
@@ -1210,45 +1335,6 @@ static const struct ethtool_ops tun_ethtool_ops = {
.set_rx_csum = tun_set_rx_csum
};
-static int tun_init_net(struct net *net)
-{
- struct tun_net *tn;
-
- tn = kmalloc(sizeof(*tn), GFP_KERNEL);
- if (tn == NULL)
- return -ENOMEM;
-
- INIT_LIST_HEAD(&tn->dev_list);
-
- if (net_assign_generic(net, tun_net_id, tn)) {
- kfree(tn);
- return -ENOMEM;
- }
-
- return 0;
-}
-
-static void tun_exit_net(struct net *net)
-{
- struct tun_net *tn;
- struct tun_struct *tun, *nxt;
-
- tn = net_generic(net, tun_net_id);
-
- rtnl_lock();
- list_for_each_entry_safe(tun, nxt, &tn->dev_list, list) {
- DBG(KERN_INFO "%s cleaned up\n", tun->dev->name);
- unregister_netdevice(tun->dev);
- }
- rtnl_unlock();
-
- kfree(tn);
-}
-
-static struct pernet_operations tun_net_ops = {
- .init = tun_init_net,
- .exit = tun_exit_net,
-};
static int __init tun_init(void)
{
@@ -1257,10 +1343,10 @@ static int __init tun_init(void)
printk(KERN_INFO "tun: %s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
printk(KERN_INFO "tun: %s\n", DRV_COPYRIGHT);
- ret = register_pernet_gen_device(&tun_net_id, &tun_net_ops);
+ ret = rtnl_link_register(&tun_link_ops);
if (ret) {
- printk(KERN_ERR "tun: Can't register pernet ops\n");
- goto err_pernet;
+ printk(KERN_ERR "tun: Can't register link_ops\n");
+ goto err_linkops;
}
ret = misc_register(&tun_miscdev);
@@ -1268,18 +1354,17 @@ static int __init tun_init(void)
printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);
goto err_misc;
}
- return 0;
-
+ return 0;
err_misc:
- unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
-err_pernet:
+ rtnl_link_unregister(&tun_link_ops);
+err_linkops:
return ret;
}
static void tun_cleanup(void)
{
misc_deregister(&tun_miscdev);
- unregister_pernet_gen_device(tun_net_id, &tun_net_ops);
+ rtnl_link_unregister(&tun_link_ops);
}
module_init(tun_init);
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-15 10:37:38 +0000