9 files changed, 52 insertions, 10 deletions
diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h
index 065fb372e355..b1c9b542c021 100644
--- a/arch/alpha/include/uapi/asm/socket.h
+++ b/arch/alpha/include/uapi/asm/socket.h
@@ -115,4 +115,6 @@
 #define SO_TXTIME		61
 #define SCM_TXTIME		SO_TXTIME
 
+#define SO_BINDTOIFINDEX	62
+
 #endif /* _UAPI_ASM_SOCKET_H */
diff --git a/arch/ia64/include/uapi/asm/socket.h b/arch/ia64/include/uapi/asm/socket.h
index c872c4e6bafb..ba0d245f9576 100644
--- a/arch/ia64/include/uapi/asm/socket.h
+++ b/arch/ia64/include/uapi/asm/socket.h
@@ -117,4 +117,6 @@
 #define SO_TXTIME		61
 #define SCM_TXTIME		SO_TXTIME
 
+#define SO_BINDTOIFINDEX	62
+
 #endif /* _ASM_IA64_SOCKET_H */
diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h
index 71370fb3ceef..73e25e35d803 100644
--- a/arch/mips/include/uapi/asm/socket.h
+++ b/arch/mips/include/uapi/asm/socket.h
@@ -126,4 +126,6 @@
 #define SO_TXTIME		61
 #define SCM_TXTIME		SO_TXTIME
 
+#define SO_BINDTOIFINDEX	62
+
 #endif /* _UAPI_ASM_SOCKET_H */
diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h
index 061b9cf2a779..52bed5976cbe 100644
--- a/arch/parisc/include/uapi/asm/socket.h
+++ b/arch/parisc/include/uapi/asm/socket.h
@@ -107,4 +107,6 @@
 #define SO_TXTIME		0x4036
 #define SCM_TXTIME		SO_TXTIME
 
+#define SO_BINDTOIFINDEX	0x4037
+
 #endif /* _UAPI_ASM_SOCKET_H */
diff --git a/arch/s390/include/uapi/asm/socket.h b/arch/s390/include/uapi/asm/socket.h
index 39d901476ee5..49c971587087 100644
--- a/arch/s390/include/uapi/asm/socket.h
+++ b/arch/s390/include/uapi/asm/socket.h
@@ -114,4 +114,6 @@
 #define SO_TXTIME		61
 #define SCM_TXTIME		SO_TXTIME
 
+#define SO_BINDTOIFINDEX	62
+
 #endif /* _ASM_SOCKET_H */
diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h
index 7ea35e5601b6..bbdb81594dd4 100644
--- a/arch/sparc/include/uapi/asm/socket.h
+++ b/arch/sparc/include/uapi/asm/socket.h
@@ -104,6 +104,8 @@
 #define SO_TXTIME		0x003f
 #define SCM_TXTIME		SO_TXTIME
 
+#define SO_BINDTOIFINDEX	0x0041
+
 /* Security levels - as per NRL IPv6 - don't actually do anything */
 #define SO_SECURITY_AUTHENTICATION		0x5001
 #define SO_SECURITY_ENCRYPTION_TRANSPORT	0x5002
diff --git a/arch/xtensa/include/uapi/asm/socket.h b/arch/xtensa/include/uapi/asm/socket.h
index 1de07a7f7680..b434217783d0 100644
--- a/arch/xtensa/include/uapi/asm/socket.h
+++ b/arch/xtensa/include/uapi/asm/socket.h
@@ -119,4 +119,6 @@
 #define SO_TXTIME		61
 #define SCM_TXTIME		SO_TXTIME
 
+#define SO_BINDTOIFINDEX	62
+
 #endif	/* _XTENSA_SOCKET_H */
diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h
index a12692e5f7a8..3066ab3853a8 100644
--- a/include/uapi/asm-generic/socket.h
+++ b/include/uapi/asm-generic/socket.h
@@ -110,4 +110,6 @@
 #define SO_TXTIME		61
 #define SCM_TXTIME		SO_TXTIME
 
+#define SO_BINDTOIFINDEX	62
+
 #endif /* __ASM_GENERIC_SOCKET_H */
diff --git a/net/core/sock.c b/net/core/sock.c
index 6aa2e7e0b4fb..b53764ebb973 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -520,14 +520,11 @@ struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
 }
 EXPORT_SYMBOL(sk_dst_check);
 
-static int sock_setbindtodevice(struct sock *sk, char __user *optval,
-				int optlen)
+static int sock_setbindtodevice_locked(struct sock *sk, int ifindex)
 {
 	int ret = -ENOPROTOOPT;
 #ifdef CONFIG_NETDEVICES
 	struct net *net = sock_net(sk);
-	char devname[IFNAMSIZ];
-	int index;
 
 	/* Sorry... */
 	ret = -EPERM;
@@ -535,6 +532,32 @@ static int sock_setbindtodevice(struct sock *sk, char __user *optval,
 		goto out;
 
 	ret = -EINVAL;
+	if (ifindex < 0)
+		goto out;
+
+	sk->sk_bound_dev_if = ifindex;
+	if (sk->sk_prot->rehash)
+		sk->sk_prot->rehash(sk);
+	sk_dst_reset(sk);
+
+	ret = 0;
+
+out:
+#endif
+
+	return ret;
+}
+
+static int sock_setbindtodevice(struct sock *sk, char __user *optval,
+				int optlen)
+{
+	int ret = -ENOPROTOOPT;
+#ifdef CONFIG_NETDEVICES
+	struct net *net = sock_net(sk);
+	char devname[IFNAMSIZ];
+	int index;
+
+	ret = -EINVAL;
 	if (optlen < 0)
 		goto out;
 
@@ -566,14 +589,9 @@ static int sock_setbindtodevice(struct sock *sk, char __user *optval,
 	}
 
 	lock_sock(sk);
-	sk->sk_bound_dev_if = index;
-	if (sk->sk_prot->rehash)
-		sk->sk_prot->rehash(sk);
-	sk_dst_reset(sk);
+	ret = sock_setbindtodevice_locked(sk, index);
 	release_sock(sk);
 
-	ret = 0;
-
 out:
 #endif
 
@@ -1055,6 +1073,10 @@ set_rcvbuf:
 		}
 		break;
 
+	case SO_BINDTOIFINDEX:
+		ret = sock_setbindtodevice_locked(sk, val);
+		break;
+
 	default:
 		ret = -ENOPROTOOPT;
 		break;
@@ -1399,6 +1421,10 @@ int sock_getsockopt(struct socket *sock, int level, int optname,
 				  SOF_TXTIME_REPORT_ERRORS : 0;
 		break;
 
+	case SO_BINDTOIFINDEX:
+		v.val = sk->sk_bound_dev_if;
+		break;
+
 	default:
 		/* We implement the SO_SNDLOWAT etc to not be settable
 		 * (1003.1g 7).