[UDP(-Lite)]: consolidate v4 and v6 get|setsockopt code

This patch consolidates set/getsockopt code between UDP(-Lite) v4 and 6. The
justification is that UDP(-Lite) is a transport-layer protocol and therefore
the socket option code (at least in theory) should be AF-independent.

Furthermore, there is the following code reduplication:
 * do_udp{,v6}_getsockopt is 100% identical between v4 and v6
 * do_udp{,v6}_setsockopt is identical up to the following differerence
	--v4 in contrast to v4 additionally allows the experimental encapsulation
          types  UDP_ENCAP_ESPINUDP and UDP_ENCAP_ESPINUDP_NON_IKE
	--the remainder is identical between v4 and v6
   I believe that this difference is of little relevance.

The advantages in not duplicating twice almost completely identical code.

The patch further simplifies the interface of udp{,v6}_push_pending_frames,
since for the second argument (struct udp_sock *up) it always holds that
up = udp_sk(sk); where sk is the first function argument.
Signed-off-by: Gerrit Renker  <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/udp.h

@@ -134,6 +134,11 @@ extern int	udp_ioctl(struct sock *sk, int cmd, unsigned long arg);
 extern int	udp_disconnect(struct sock *sk, int flags);
 extern unsigned int udp_poll(struct file *file, struct socket *sock,
 			     poll_table *wait);
+extern int 	udp_lib_getsockopt(struct sock *sk, int level, int optname,
+			           char __user *optval, int __user *optlen);
+extern int 	udp_lib_setsockopt(struct sock *sk, int level, int optname,
+				   char __user *optval, int optlen,
+				   int (*push_pending_frames)(struct sock *));
 
 DECLARE_SNMP_STAT(struct udp_mib, udp_statistics);
 /*

net/ipv4/udp.c

@@ -448,8 +448,9 @@ static void udp4_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
 /*
  * Push out all pending data as one UDP datagram. Socket is locked.
  */
-static int udp_push_pending_frames(struct sock *sk, struct udp_sock *up)
+static int udp_push_pending_frames(struct sock *sk)
 {
+	struct udp_sock  *up = udp_sk(sk);
 	struct inet_sock *inet = inet_sk(sk);
 	struct flowi *fl = &inet->cork.fl;
 	struct sk_buff *skb;
@@ -673,7 +674,7 @@ do_append_data:
 	if (err)
 		udp_flush_pending_frames(sk);
 	else if (!corkreq)
-		err = udp_push_pending_frames(sk, up);
+		err = udp_push_pending_frames(sk);
 	else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
 		up->pending = 0;
 	release_sock(sk);
@@ -746,7 +747,7 @@ int udp_sendpage(struct sock *sk, struct page *page, int offset,
 
 	up->len += size;
 	if (!(up->corkflag || (flags&MSG_MORE)))
-		ret = udp_push_pending_frames(sk, up);
+		ret = udp_push_pending_frames(sk);
 	if (!ret)
 		ret = size;
 out:
@@ -1299,8 +1300,9 @@ int udp_destroy_sock(struct sock *sk)
 /*
  *	Socket option code for UDP
  */
-static int do_udp_setsockopt(struct sock *sk, int level, int optname,
-			  char __user *optval, int optlen)
+int udp_lib_setsockopt(struct sock *sk, int level, int optname,
+		       char __user *optval, int optlen,
+		       int (*push_pending_frames)(struct sock *))
 {
 	struct udp_sock *up = udp_sk(sk);
 	int val;
@@ -1319,7 +1321,7 @@ static int do_udp_setsockopt(struct sock *sk, int level, int optname,
 		} else {
 			up->corkflag = 0;
 			lock_sock(sk);
-			udp_push_pending_frames(sk, up);
+			(*push_pending_frames)(sk);
 			release_sock(sk);
 		}
 		break;
@@ -1375,7 +1377,8 @@ int udp_setsockopt(struct sock *sk, int level, int optname,
 		   char __user *optval, int optlen)
 {
 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
-		return do_udp_setsockopt(sk, level, optname, optval, optlen);
+		return udp_lib_setsockopt(sk, level, optname, optval, optlen,
+					  udp_push_pending_frames);
 	return ip_setsockopt(sk, level, optname, optval, optlen);
 }
 
@@ -1384,13 +1387,14 @@ int compat_udp_setsockopt(struct sock *sk, int level, int optname,
 			  char __user *optval, int optlen)
 {
 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
-		return do_udp_setsockopt(sk, level, optname, optval, optlen);
+		return udp_lib_setsockopt(sk, level, optname, optval, optlen,
+					  udp_push_pending_frames);
 	return compat_ip_setsockopt(sk, level, optname, optval, optlen);
 }
 #endif
 
-static int do_udp_getsockopt(struct sock *sk, int level, int optname,
-			  char __user *optval, int __user *optlen)
+int udp_lib_getsockopt(struct sock *sk, int level, int optname,
+		       char __user *optval, int __user *optlen)
 {
 	struct udp_sock *up = udp_sk(sk);
 	int val, len;
@@ -1437,7 +1441,7 @@ int udp_getsockopt(struct sock *sk, int level, int optname,
 		   char __user *optval, int __user *optlen)
 {
 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
-		return do_udp_getsockopt(sk, level, optname, optval, optlen);
+		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
 	return ip_getsockopt(sk, level, optname, optval, optlen);
 }
 
@@ -1446,7 +1450,7 @@ int compat_udp_getsockopt(struct sock *sk, int level, int optname,
 				 char __user *optval, int __user *optlen)
 {
 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
-		return do_udp_getsockopt(sk, level, optname, optval, optlen);
+		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
 	return compat_ip_getsockopt(sk, level, optname, optval, optlen);
 }
 #endif
@@ -1716,6 +1720,8 @@ EXPORT_SYMBOL(udp_ioctl);
 EXPORT_SYMBOL(udp_get_port);
 EXPORT_SYMBOL(udp_prot);
 EXPORT_SYMBOL(udp_sendmsg);
+EXPORT_SYMBOL(udp_lib_getsockopt);
+EXPORT_SYMBOL(udp_lib_setsockopt);
 EXPORT_SYMBOL(udp_poll);
 
 #ifdef CONFIG_PROC_FS

net/ipv6/udp.c

@@ -505,10 +505,11 @@ static void udp_v6_flush_pending_frames(struct sock *sk)
  *	Sending
  */
 
-static int udp_v6_push_pending_frames(struct sock *sk, struct udp_sock *up)
+static int udp_v6_push_pending_frames(struct sock *sk)
 {
 	struct sk_buff *skb;
 	struct udphdr *uh;
+	struct udp_sock  *up = udp_sk(sk);
 	struct inet_sock *inet = inet_sk(sk);
 	struct flowi *fl = &inet->cork.fl;
 	int err = 0;
@@ -782,7 +783,7 @@ do_append_data:
 	if (err)
 		udp_v6_flush_pending_frames(sk);
 	else if (!corkreq)
-		err = udp_v6_push_pending_frames(sk, up);
+		err = udp_v6_push_pending_frames(sk);
 	else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
 		up->pending = 0;
 
@@ -844,72 +845,12 @@ int udpv6_destroy_sock(struct sock *sk)
 /*
  *	Socket option code for UDP
  */
-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(optlen<sizeof(int))
-		return -EINVAL;
-
-	if (get_user(val, (int __user *)optval))
-		return -EFAULT;
-
-	switch(optname) {
-	case UDP_CORK:
-		if (val != 0) {
-			up->corkflag = 1;
-		} else {
-			up->corkflag = 0;
-			lock_sock(sk);
-			udp_v6_push_pending_frames(sk, up);
-			release_sock(sk);
-		}
-		break;
-	case UDP_ENCAP:
-		switch (val) {
-		case 0:
-			up->encap_type = val;
-			break;
-		default:
-			err = -ENOPROTOOPT;
-			break;
-		}
-		break;
-
-	case UDPLITE_SEND_CSCOV:
-		if (!up->pcflag)         /* Disable the option on UDP sockets */
-			return -ENOPROTOOPT;
-		if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
-			val = 8;
-		up->pcslen = val;
-		up->pcflag |= UDPLITE_SEND_CC;
-		break;
-
-	case UDPLITE_RECV_CSCOV:
-		if (!up->pcflag)         /* Disable the option on UDP sockets */
-			return -ENOPROTOOPT;
-		if (val != 0 && val < 8) /* Avoid silly minimal values.       */
-			val = 8;
-		up->pcrlen = val;
-		up->pcflag |= UDPLITE_RECV_CC;
-		break;
-
-	default:
-		err = -ENOPROTOOPT;
-		break;
-	};
-
-	return err;
-}
-
 int udpv6_setsockopt(struct sock *sk, int level, int optname,
 		     char __user *optval, int optlen)
 {
 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
-		return do_udpv6_setsockopt(sk, level, optname, optval, optlen);
+		return udp_lib_setsockopt(sk, level, optname, optval, optlen,
+					  udp_v6_push_pending_frames);
 	return ipv6_setsockopt(sk, level, optname, optval, optlen);
 }
 
@@ -918,58 +859,17 @@ int compat_udpv6_setsockopt(struct sock *sk, int level, int optname,
 			    char __user *optval, int optlen)
 {
 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
-		return do_udpv6_setsockopt(sk, level, optname, optval, optlen);
+		return udp_lib_setsockopt(sk, level, optname, optval, optlen,
+					  udp_v6_push_pending_frames);
 	return compat_ipv6_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(get_user(len,optlen))
-		return -EFAULT;
-
-	len = min_t(unsigned int, len, sizeof(int));
-	
-	if(len < 0)
-		return -EINVAL;
-
-	switch(optname) {
-	case UDP_CORK:
-		val = up->corkflag;
-		break;
-
-	case UDP_ENCAP:
-		val = up->encap_type;
-		break;
-
-	case UDPLITE_SEND_CSCOV:
-		val = up->pcslen;
-		break;
-
-	case UDPLITE_RECV_CSCOV:
-		val = up->pcrlen;
-		break;
-
-	default:
-		return -ENOPROTOOPT;
-	};
-
-  	if(put_user(len, optlen))
-  		return -EFAULT;
-	if(copy_to_user(optval, &val,len))
-		return -EFAULT;
-  	return 0;
-}
-
 int udpv6_getsockopt(struct sock *sk, int level, int optname,
 		     char __user *optval, int __user *optlen)
 {
 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
-		return do_udpv6_getsockopt(sk, level, optname, optval, optlen);
+		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
 	return ipv6_getsockopt(sk, level, optname, optval, optlen);
 }
 
@@ -978,7 +878,7 @@ int compat_udpv6_getsockopt(struct sock *sk, int level, int optname,
 			    char __user *optval, int __user *optlen)
 {
 	if (level == SOL_UDP  ||  level == SOL_UDPLITE)
-		return do_udpv6_getsockopt(sk, level, optname, optval, optlen);
+		return udp_lib_getsockopt(sk, level, optname, optval, optlen);
 	return compat_ipv6_getsockopt(sk, level, optname, optval, optlen);
 }
 #endif