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-rw-r--r--include/linux/netdevice.h2
-rw-r--r--net/core/dev.c21
-rw-r--r--net/core/sock.c64
3 files changed, 81 insertions, 6 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index e46c830..e9929ab 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1567,6 +1567,8 @@ extern int call_netdevice_notifiers(unsigned long val, struct net_device *dev);
extern rwlock_t dev_base_lock; /* Device list lock */
+extern seqlock_t devnet_rename_seq; /* Device rename lock */
+
#define for_each_netdev(net, d) \
list_for_each_entry(d, &(net)->dev_base_head, dev_list)
diff --git a/net/core/dev.c b/net/core/dev.c
index 7304ea8..2a5f5586 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -203,6 +203,8 @@ static struct list_head offload_base __read_mostly;
DEFINE_RWLOCK(dev_base_lock);
EXPORT_SYMBOL(dev_base_lock);
+DEFINE_SEQLOCK(devnet_rename_seq);
+
static inline void dev_base_seq_inc(struct net *net)
{
while (++net->dev_base_seq == 0);
@@ -1091,22 +1093,31 @@ int dev_change_name(struct net_device *dev, const char *newname)
if (dev->flags & IFF_UP)
return -EBUSY;
- if (strncmp(newname, dev->name, IFNAMSIZ) == 0)
+ write_seqlock(&devnet_rename_seq);
+
+ if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
+ write_sequnlock(&devnet_rename_seq);
return 0;
+ }
memcpy(oldname, dev->name, IFNAMSIZ);
err = dev_get_valid_name(net, dev, newname);
- if (err < 0)
+ if (err < 0) {
+ write_sequnlock(&devnet_rename_seq);
return err;
+ }
rollback:
ret = device_rename(&dev->dev, dev->name);
if (ret) {
memcpy(dev->name, oldname, IFNAMSIZ);
+ write_sequnlock(&devnet_rename_seq);
return ret;
}
+ write_sequnlock(&devnet_rename_seq);
+
write_lock_bh(&dev_base_lock);
hlist_del_rcu(&dev->name_hlist);
write_unlock_bh(&dev_base_lock);
@@ -1124,6 +1135,7 @@ rollback:
/* err >= 0 after dev_alloc_name() or stores the first errno */
if (err >= 0) {
err = ret;
+ write_seqlock(&devnet_rename_seq);
memcpy(dev->name, oldname, IFNAMSIZ);
goto rollback;
} else {
@@ -4148,6 +4160,7 @@ static int dev_ifname(struct net *net, struct ifreq __user *arg)
{
struct net_device *dev;
struct ifreq ifr;
+ unsigned seq;
/*
* Fetch the caller's info block.
@@ -4156,6 +4169,8 @@ static int dev_ifname(struct net *net, struct ifreq __user *arg)
if (copy_from_user(&ifr, arg, sizeof(struct ifreq)))
return -EFAULT;
+retry:
+ seq = read_seqbegin(&devnet_rename_seq);
rcu_read_lock();
dev = dev_get_by_index_rcu(net, ifr.ifr_ifindex);
if (!dev) {
@@ -4165,6 +4180,8 @@ static int dev_ifname(struct net *net, struct ifreq __user *arg)
strcpy(ifr.ifr_name, dev->name);
rcu_read_unlock();
+ if (read_seqretry(&devnet_rename_seq, seq))
+ goto retry;
if (copy_to_user(arg, &ifr, sizeof(struct ifreq)))
return -EFAULT;
diff --git a/net/core/sock.c b/net/core/sock.c
index d4f7b58..a692ef4 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -505,7 +505,8 @@ struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
}
EXPORT_SYMBOL(sk_dst_check);
-static int sock_bindtodevice(struct sock *sk, char __user *optval, int optlen)
+static int sock_setbindtodevice(struct sock *sk, char __user *optval,
+ int optlen)
{
int ret = -ENOPROTOOPT;
#ifdef CONFIG_NETDEVICES
@@ -562,6 +563,59 @@ out:
return ret;
}
+static int sock_getbindtodevice(struct sock *sk, char __user *optval,
+ int __user *optlen, int len)
+{
+ int ret = -ENOPROTOOPT;
+#ifdef CONFIG_NETDEVICES
+ struct net *net = sock_net(sk);
+ struct net_device *dev;
+ char devname[IFNAMSIZ];
+ unsigned seq;
+
+ if (sk->sk_bound_dev_if == 0) {
+ len = 0;
+ goto zero;
+ }
+
+ ret = -EINVAL;
+ if (len < IFNAMSIZ)
+ goto out;
+
+retry:
+ seq = read_seqbegin(&devnet_rename_seq);
+ rcu_read_lock();
+ dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
+ ret = -ENODEV;
+ if (!dev) {
+ rcu_read_unlock();
+ goto out;
+ }
+
+ strcpy(devname, dev->name);
+ rcu_read_unlock();
+ if (read_seqretry(&devnet_rename_seq, seq))
+ goto retry;
+
+ len = strlen(devname) + 1;
+
+ ret = -EFAULT;
+ if (copy_to_user(optval, devname, len))
+ goto out;
+
+zero:
+ ret = -EFAULT;
+ if (put_user(len, optlen))
+ goto out;
+
+ ret = 0;
+
+out:
+#endif
+
+ return ret;
+}
+
static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
{
if (valbool)
@@ -589,7 +643,7 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
*/
if (optname == SO_BINDTODEVICE)
- return sock_bindtodevice(sk, optval, optlen);
+ return sock_setbindtodevice(sk, optval, optlen);
if (optlen < sizeof(int))
return -EINVAL;
@@ -1075,15 +1129,17 @@ int sock_getsockopt(struct socket *sock, int level, int optname,
case SO_NOFCS:
v.val = sock_flag(sk, SOCK_NOFCS);
break;
+
case SO_BINDTODEVICE:
- v.val = sk->sk_bound_dev_if;
- break;
+ return sock_getbindtodevice(sk, optval, optlen, len);
+
case SO_GET_FILTER:
len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
if (len < 0)
return len;
goto lenout;
+
default:
return -ENOPROTOOPT;
}
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