af_unix: Move CINQ/COUTQ code to helpers

Currently tcp diag reports rqlen and wqlen values similar to how
the CINQ/COUTQ iotcls do. To make unix diag report these values
in the same way move the respective code into helpers.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/af_unix.h

@@ -66,6 +66,9 @@ struct unix_sock {
 
 #define peer_wait peer_wq.wait
 
+long unix_inq_len(struct sock *sk);
+long unix_outq_len(struct sock *sk);
+
 #ifdef CONFIG_SYSCTL
 extern int unix_sysctl_register(struct net *net);
 extern void unix_sysctl_unregister(struct net *net);

net/unix/af_unix.c

@@ -2065,25 +2065,13 @@ static int unix_shutdown(struct socket *sock, int mode)
 	return 0;
 }
 
-static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
+long unix_inq_len(struct sock *sk)
 {
-	struct sock *sk = sock->sk;
-	long amount = 0;
-	int err;
-
-	switch (cmd) {
-	case SIOCOUTQ:
-		amount = sk_wmem_alloc_get(sk);
-		err = put_user(amount, (int __user *)arg);
-		break;
-	case SIOCINQ:
-		{
 	struct sk_buff *skb;
+	long amount = 0;
 
-			if (sk->sk_state == TCP_LISTEN) {
-				err = -EINVAL;
-				break;
-			}
+	if (sk->sk_state == TCP_LISTEN)
+		return -EINVAL;
 
 	spin_lock(&sk->sk_receive_queue.lock);
 	if (sk->sk_type == SOCK_STREAM ||
@@ -2096,10 +2084,35 @@ static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 			amount = skb->len;
 	}
 	spin_unlock(&sk->sk_receive_queue.lock);
+
+	return amount;
+}
+EXPORT_SYMBOL_GPL(unix_inq_len);
+
+long unix_outq_len(struct sock *sk)
+{
+	return sk_wmem_alloc_get(sk);
+}
+EXPORT_SYMBOL_GPL(unix_outq_len);
+
+static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
+{
+	struct sock *sk = sock->sk;
+	long amount = 0;
+	int err;
+
+	switch (cmd) {
+	case SIOCOUTQ:
+		amount = unix_outq_len(sk);
+		err = put_user(amount, (int __user *)arg);
+		break;
+	case SIOCINQ:
+		amount = unix_inq_len(sk);
+		if (amount < 0)
+			err = amount;
+		else
 			err = put_user(amount, (int __user *)arg);
 		break;
-		}
-
 	default:
 		err = -ENOIOCTLCMD;
 		break;