net: add sock_bindtoindex

Add a helper to directly set the SO_BINDTOIFINDEX sockopt from kernel
space without going through a fake uaccess.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/sock.h b/include/net/sock.h
index 9a7b9e98685acc69c3fda42f84b2bce1c39befe3..cdec7bc055d5ba50f0e11dcd09d7c735515c8c72 100644 (file)
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2688,6 +2688,7 @@ static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif)
 
 void sock_def_readable(struct sock *sk);
 
+int sock_bindtoindex(struct sock *sk, int ifindex);
 void sock_no_linger(struct sock *sk);
 void sock_set_priority(struct sock *sk, u32 priority);
 void sock_set_reuseaddr(struct sock *sk);

diff --git a/net/core/sock.c b/net/core/sock.c
index d3b1d61e4f768dcbfbe0a61a29e5c4e90aa8dba7..23f80880fbb2c472f3f7167b4b97eddff2c3409b 100644 (file)
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -566,7 +566,7 @@ struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
 }
 EXPORT_SYMBOL(sk_dst_check);
 
-static int sock_setbindtodevice_locked(struct sock *sk, int ifindex)
+static int sock_bindtoindex_locked(struct sock *sk, int ifindex)
 {
        int ret = -ENOPROTOOPT;
 #ifdef CONFIG_NETDEVICES
@@ -594,6 +594,18 @@ out:
        return ret;
 }
 
+int sock_bindtoindex(struct sock *sk, int ifindex)
+{
+       int ret;
+
+       lock_sock(sk);
+       ret = sock_bindtoindex_locked(sk, ifindex);
+       release_sock(sk);
+
+       return ret;
+}
+EXPORT_SYMBOL(sock_bindtoindex);
+
 static int sock_setbindtodevice(struct sock *sk, char __user *optval,
                                int optlen)
 {
@@ -634,10 +646,7 @@ static int sock_setbindtodevice(struct sock *sk, char __user *optval,
                        goto out;
        }
 
-       lock_sock(sk);
-       ret = sock_setbindtodevice_locked(sk, index);
-       release_sock(sk);
-
+       return sock_bindtoindex(sk, index);
 out:
 #endif
 
@@ -1216,7 +1225,7 @@ set_rcvbuf:
                break;
 
        case SO_BINDTOIFINDEX:
-               ret = sock_setbindtodevice_locked(sk, val);
+               ret = sock_bindtoindex_locked(sk, val);
                break;
 
        default:

diff --git a/net/ipv4/udp_tunnel.c b/net/ipv4/udp_tunnel.c
index 150e6f0fdbf59ee98a80203a40f865fad8e5b737..2158e8bddf41c7fd500de67c9d3e891ace03321c 100644 (file)
--- a/net/ipv4/udp_tunnel.c
+++ b/net/ipv4/udp_tunnel.c
@@ -22,9 +22,7 @@ int udp_sock_create4(struct net *net, struct udp_port_cfg *cfg,
                goto error;
 
        if (cfg->bind_ifindex) {
-               err = kernel_setsockopt(sock, SOL_SOCKET, SO_BINDTOIFINDEX,
-                                       (void *)&cfg->bind_ifindex,
-                                       sizeof(cfg->bind_ifindex));
+               err = sock_bindtoindex(sock->sk, cfg->bind_ifindex);
                if (err < 0)
                        goto error;
        }

diff --git a/net/ipv6/ip6_udp_tunnel.c b/net/ipv6/ip6_udp_tunnel.c
index 58956a6b66a21568cb4709191b458f82490615cb..6523609516d25a8748a6886587ce06b91ca80d46 100644 (file)
--- a/net/ipv6/ip6_udp_tunnel.c
+++ b/net/ipv6/ip6_udp_tunnel.c
@@ -33,9 +33,7 @@ int udp_sock_create6(struct net *net, struct udp_port_cfg *cfg,
                        goto error;
        }
        if (cfg->bind_ifindex) {
-               err = kernel_setsockopt(sock, SOL_SOCKET, SO_BINDTOIFINDEX,
-                                       (void *)&cfg->bind_ifindex,
-                                       sizeof(cfg->bind_ifindex));
+               err = sock_bindtoindex(sock->sk, cfg->bind_ifindex);
                if (err < 0)
                        goto error;
        }