[NET]: {get|set}sockopt compatibility layer

This patch extends {get|set}sockopt compatibility layer in order to
move protocol specific parts to their place and avoid huge universal
net/compat.c file in the future.

Signed-off-by: Dmitry Mishin <dim@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index c476488..538ada0 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -880,16 +880,13 @@
 /*
  *	Socket option code for UDP
  */
-static int udpv6_setsockopt(struct sock *sk, int level, int optname, 
+static int do_udpv6_setsockopt(struct sock *sk, int level, int optname,
 			  char __user *optval, int optlen)
 {
 	struct udp_sock *up = udp_sk(sk);
 	int val;
 	int err = 0;
 
-	if (level != SOL_UDP)
-		return ipv6_setsockopt(sk, level, optname, optval, optlen);
-
 	if(optlen<sizeof(int))
 		return -EINVAL;
 
@@ -927,15 +924,31 @@
 	return err;
 }
 
-static int udpv6_getsockopt(struct sock *sk, int level, int optname, 
+static int udpv6_setsockopt(struct sock *sk, int level, int optname,
+			  char __user *optval, int optlen)
+{
+	if (level != SOL_UDP)
+		return ipv6_setsockopt(sk, level, optname, optval, optlen);
+	return do_udpv6_setsockopt(sk, level, optname, optval, optlen);
+}
+
+#ifdef CONFIG_COMPAT
+static int compat_udpv6_setsockopt(struct sock *sk, int level, int optname,
+		char __user *optval, int optlen)
+{
+	if (level != SOL_UDP)
+		return compat_ipv6_setsockopt(sk, level,
+				optname, optval, optlen);
+	return do_udpv6_setsockopt(sk, level, optname, optval, optlen);
+}
+#endif
+
+static int do_udpv6_getsockopt(struct sock *sk, int level, int optname,
 			  char __user *optval, int __user *optlen)
 {
 	struct udp_sock *up = udp_sk(sk);
 	int val, len;
 
-	if (level != SOL_UDP)
-		return ipv6_getsockopt(sk, level, optname, optval, optlen);
-
 	if(get_user(len,optlen))
 		return -EFAULT;
 
@@ -964,6 +977,25 @@
   	return 0;
 }
 
+static int udpv6_getsockopt(struct sock *sk, int level, int optname,
+			  char __user *optval, int __user *optlen)
+{
+	if (level != SOL_UDP)
+		return ipv6_getsockopt(sk, level, optname, optval, optlen);
+	return do_udpv6_getsockopt(sk, level, optname, optval, optlen);
+}
+
+#ifdef CONFIG_COMPAT
+static int compat_udpv6_getsockopt(struct sock *sk, int level, int optname,
+			  char __user *optval, int __user *optlen)
+{
+	if (level != SOL_UDP)
+		return compat_ipv6_getsockopt(sk, level,
+				optname, optval, optlen);
+	return do_udpv6_getsockopt(sk, level, optname, optval, optlen);
+}
+#endif
+
 static struct inet6_protocol udpv6_protocol = {
 	.handler	=	udpv6_rcv,
 	.err_handler	=	udpv6_err,
@@ -1046,6 +1078,10 @@
 	.destroy =	udpv6_destroy_sock,
 	.setsockopt =	udpv6_setsockopt,
 	.getsockopt =	udpv6_getsockopt,
+#ifdef CONFIG_COMPAT
+	.compat_setsockopt =	compat_udpv6_setsockopt,
+	.compat_getsockopt =	compat_udpv6_getsockopt,
+#endif
 	.sendmsg =	udpv6_sendmsg,
 	.recvmsg =	udpv6_recvmsg,
 	.backlog_rcv =	udpv6_queue_rcv_skb,