ipv6: avoid dev_hold()/dev_put() in rawv6_bind()
Using RCU helps not touching device refcount in rawv6_bind()
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index 818ef21b..926ce8e 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -249,7 +249,7 @@
/* Raw sockets are IPv6 only */
if (addr_type == IPV6_ADDR_MAPPED)
- return(-EADDRNOTAVAIL);
+ return -EADDRNOTAVAIL;
lock_sock(sk);
@@ -257,6 +257,7 @@
if (sk->sk_state != TCP_CLOSE)
goto out;
+ rcu_read_lock();
/* Check if the address belongs to the host. */
if (addr_type != IPV6_ADDR_ANY) {
struct net_device *dev = NULL;
@@ -272,13 +273,13 @@
/* Binding to link-local address requires an interface */
if (!sk->sk_bound_dev_if)
- goto out;
+ goto out_unlock;
- dev = dev_get_by_index(sock_net(sk), sk->sk_bound_dev_if);
- if (!dev) {
- err = -ENODEV;
- goto out;
- }
+ err = -ENODEV;
+ dev = dev_get_by_index_rcu(sock_net(sk),
+ sk->sk_bound_dev_if);
+ if (!dev)
+ goto out_unlock;
}
/* ipv4 addr of the socket is invalid. Only the
@@ -289,13 +290,9 @@
err = -EADDRNOTAVAIL;
if (!ipv6_chk_addr(sock_net(sk), &addr->sin6_addr,
dev, 0)) {
- if (dev)
- dev_put(dev);
- goto out;
+ goto out_unlock;
}
}
- if (dev)
- dev_put(dev);
}
inet->inet_rcv_saddr = inet->inet_saddr = v4addr;
@@ -303,6 +300,8 @@
if (!(addr_type & IPV6_ADDR_MULTICAST))
ipv6_addr_copy(&np->saddr, &addr->sin6_addr);
err = 0;
+out_unlock:
+ rcu_read_unlock();
out:
release_sock(sk);
return err;