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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.c89
1 files changed, 54 insertions, 35 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index fbd106edbe59..cc09b67c23bc 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -109,11 +109,11 @@ struct tap_filter {
unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
};
-/* 1024 is probably a high enough limit: modern hypervisors seem to support on
- * the order of 100-200 CPUs so this leaves us some breathing space if we want
- * to match a queue per guest CPU.
- */
-#define MAX_TAP_QUEUES 1024
+/* DEFAULT_MAX_NUM_RSS_QUEUES were choosed to let the rx/tx queues allocated for
+ * the netdevice to be fit in one page. So we can make sure the success of
+ * memory allocation. TODO: increase the limit. */
+#define MAX_TAP_QUEUES DEFAULT_MAX_NUM_RSS_QUEUES
+#define MAX_TAP_FLOWS 4096
#define TUN_FLOW_EXPIRE (3 * HZ)
@@ -185,6 +185,8 @@ struct tun_struct {
unsigned long ageing_time;
unsigned int numdisabled;
struct list_head disabled;
+ void *security;
+ u32 flow_count;
};
static inline u32 tun_hashfn(u32 rxhash)
@@ -218,6 +220,7 @@ static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
e->queue_index = queue_index;
e->tun = tun;
hlist_add_head_rcu(&e->hash_link, head);
+ ++tun->flow_count;
}
return e;
}
@@ -228,6 +231,7 @@ static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
e->rxhash, e->queue_index);
hlist_del_rcu(&e->hash_link);
kfree_rcu(e, rcu);
+ --tun->flow_count;
}
static void tun_flow_flush(struct tun_struct *tun)
@@ -317,7 +321,8 @@ static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
e->updated = jiffies;
} else {
spin_lock_bh(&tun->lock);
- if (!tun_flow_find(head, rxhash))
+ if (!tun_flow_find(head, rxhash) &&
+ tun->flow_count < MAX_TAP_FLOWS)
tun_flow_create(tun, head, rxhash, queue_index);
if (!timer_pending(&tun->flow_gc_timer))
@@ -404,8 +409,8 @@ static void __tun_detach(struct tun_file *tfile, bool clean)
struct tun_struct *tun;
struct net_device *dev;
- tun = rcu_dereference_protected(tfile->tun,
- lockdep_rtnl_is_held());
+ tun = rtnl_dereference(tfile->tun);
+
if (tun) {
u16 index = tfile->queue_index;
BUG_ON(index >= tun->numqueues);
@@ -414,8 +419,7 @@ static void __tun_detach(struct tun_file *tfile, bool clean)
rcu_assign_pointer(tun->tfiles[index],
tun->tfiles[tun->numqueues - 1]);
rcu_assign_pointer(tfile->tun, NULL);
- ntfile = rcu_dereference_protected(tun->tfiles[index],
- lockdep_rtnl_is_held());
+ ntfile = rtnl_dereference(tun->tfiles[index]);
ntfile->queue_index = index;
--tun->numqueues;
@@ -429,8 +433,10 @@ static void __tun_detach(struct tun_file *tfile, bool clean)
/* Drop read queue */
skb_queue_purge(&tfile->sk.sk_receive_queue);
tun_set_real_num_queues(tun);
- } else if (tfile->detached && clean)
+ } else if (tfile->detached && clean) {
tun = tun_enable_queue(tfile);
+ sock_put(&tfile->sk);
+ }
if (clean) {
if (tun && tun->numqueues == 0 && tun->numdisabled == 0 &&
@@ -458,8 +464,7 @@ static void tun_detach_all(struct net_device *dev)
int i, n = tun->numqueues;
for (i = 0; i < n; i++) {
- tfile = rcu_dereference_protected(tun->tfiles[i],
- lockdep_rtnl_is_held());
+ tfile = rtnl_dereference(tun->tfiles[i]);
BUG_ON(!tfile);
wake_up_all(&tfile->wq.wait);
rcu_assign_pointer(tfile->tun, NULL);
@@ -469,8 +474,7 @@ static void tun_detach_all(struct net_device *dev)
synchronize_net();
for (i = 0; i < n; i++) {
- tfile = rcu_dereference_protected(tun->tfiles[i],
- lockdep_rtnl_is_held());
+ tfile = rtnl_dereference(tun->tfiles[i]);
/* Drop read queue */
skb_queue_purge(&tfile->sk.sk_receive_queue);
sock_put(&tfile->sk);
@@ -481,6 +485,9 @@ static void tun_detach_all(struct net_device *dev)
sock_put(&tfile->sk);
}
BUG_ON(tun->numdisabled != 0);
+
+ if (tun->flags & TUN_PERSIST)
+ module_put(THIS_MODULE);
}
static int tun_attach(struct tun_struct *tun, struct file *file)
@@ -488,8 +495,12 @@ static int tun_attach(struct tun_struct *tun, struct file *file)
struct tun_file *tfile = file->private_data;
int err;
+ err = security_tun_dev_attach(tfile->socket.sk, tun->security);
+ if (err < 0)
+ goto out;
+
err = -EINVAL;
- if (rcu_dereference_protected(tfile->tun, lockdep_rtnl_is_held()))
+ if (rtnl_dereference(tfile->tun))
goto out;
err = -EBUSY;
@@ -1371,6 +1382,7 @@ static void tun_free_netdev(struct net_device *dev)
BUG_ON(!(list_empty(&tun->disabled)));
tun_flow_uninit(tun);
+ security_tun_dev_free_security(tun->security);
free_netdev(dev);
}
@@ -1544,6 +1556,9 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
struct net_device *dev;
int err;
+ if (tfile->detached)
+ return -EINVAL;
+
dev = __dev_get_by_name(net, ifr->ifr_name);
if (dev) {
if (ifr->ifr_flags & IFF_TUN_EXCL)
@@ -1557,7 +1572,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
if (tun_not_capable(tun))
return -EPERM;
- err = security_tun_dev_attach(tfile->socket.sk);
+ err = security_tun_dev_open(tun->security);
if (err < 0)
return err;
@@ -1572,6 +1587,8 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
else {
char *name;
unsigned long flags = 0;
+ int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
+ MAX_TAP_QUEUES : 1;
if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
return -EPERM;
@@ -1595,8 +1612,8 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
name = ifr->ifr_name;
dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
- tun_setup,
- MAX_TAP_QUEUES, MAX_TAP_QUEUES);
+ tun_setup, queues, queues);
+
if (!dev)
return -ENOMEM;
@@ -1614,7 +1631,9 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
spin_lock_init(&tun->lock);
- security_tun_dev_post_create(&tfile->sk);
+ err = security_tun_dev_alloc_security(&tun->security);
+ if (err < 0)
+ goto err_free_dev;
tun_net_init(dev);
@@ -1738,8 +1757,7 @@ static void tun_detach_filter(struct tun_struct *tun, int n)
struct tun_file *tfile;
for (i = 0; i < n; i++) {
- tfile = rcu_dereference_protected(tun->tfiles[i],
- lockdep_rtnl_is_held());
+ tfile = rtnl_dereference(tun->tfiles[i]);
sk_detach_filter(tfile->socket.sk);
}
@@ -1752,8 +1770,7 @@ static int tun_attach_filter(struct tun_struct *tun)
struct tun_file *tfile;
for (i = 0; i < tun->numqueues; i++) {
- tfile = rcu_dereference_protected(tun->tfiles[i],
- lockdep_rtnl_is_held());
+ tfile = rtnl_dereference(tun->tfiles[i]);
ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
if (ret) {
tun_detach_filter(tun, i);
@@ -1771,8 +1788,7 @@ static void tun_set_sndbuf(struct tun_struct *tun)
int i;
for (i = 0; i < tun->numqueues; i++) {
- tfile = rcu_dereference_protected(tun->tfiles[i],
- lockdep_rtnl_is_held());
+ tfile = rtnl_dereference(tun->tfiles[i]);
tfile->socket.sk->sk_sndbuf = tun->sndbuf;
}
}
@@ -1787,15 +1803,16 @@ static int tun_set_queue(struct file *file, struct ifreq *ifr)
if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
tun = tfile->detached;
- if (!tun)
+ if (!tun) {
ret = -EINVAL;
- else if (tun_not_capable(tun))
- ret = -EPERM;
- else
- ret = tun_attach(tun, file);
+ goto unlock;
+ }
+ ret = security_tun_dev_attach_queue(tun->security);
+ if (ret < 0)
+ goto unlock;
+ ret = tun_attach(tun, file);
} else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
- tun = rcu_dereference_protected(tfile->tun,
- lockdep_rtnl_is_held());
+ tun = rtnl_dereference(tfile->tun);
if (!tun || !(tun->flags & TUN_TAP_MQ))
ret = -EINVAL;
else
@@ -1803,6 +1820,7 @@ static int tun_set_queue(struct file *file, struct ifreq *ifr)
} else
ret = -EINVAL;
+unlock:
rtnl_unlock();
return ret;
}
@@ -1880,10 +1898,11 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
/* Disable/Enable persist mode. Keep an extra reference to the
* module to prevent the module being unprobed.
*/
- if (arg) {
+ if (arg && !(tun->flags & TUN_PERSIST)) {
tun->flags |= TUN_PERSIST;
__module_get(THIS_MODULE);
- } else {
+ }
+ if (!arg && (tun->flags & TUN_PERSIST)) {
tun->flags &= ~TUN_PERSIST;
module_put(THIS_MODULE);
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-03-19 22:53:09 +0000