inet_diag: Split inet_diag_get_exact into parts

Similar to previous patch: the 1st part locks the inet handler
and will get generalized and the 2nd one dumps icsk-s and will
be used by TCP and DCCP handlers.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/inet_diag.c

@@ -709,19 +709,11 @@ static int inet_diag_dump_reqs(struct sk_buff *skb, struct sock *sk,
 	return err;
 }
 
-static int __inet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
-		struct inet_diag_req *r, struct nlattr *bc)
+static void inet_diag_dump_icsk(struct inet_hashinfo *hashinfo, struct sk_buff *skb,
+		struct netlink_callback *cb, struct inet_diag_req *r, struct nlattr *bc)
 {
 	int i, num;
 	int s_i, s_num;
-	const struct inet_diag_handler *handler;
-	struct inet_hashinfo *hashinfo;
-
-	handler = inet_diag_lock_handler(r->sdiag_protocol);
-	if (IS_ERR(handler))
-		goto unlock;
-
-	hashinfo = handler->idiag_hashinfo;
 
 	s_i = cb->args[1];
 	s_num = num = cb->args[2];
@@ -790,7 +782,7 @@ static int __inet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 	}
 
 	if (!(r->idiag_states & ~(TCPF_LISTEN | TCPF_SYN_RECV)))
-		goto unlock;
+		goto out;
 
 	for (i = s_i; i <= hashinfo->ehash_mask; i++) {
 		struct inet_ehash_bucket *head = &hashinfo->ehash[i];
@@ -863,8 +855,20 @@ static int __inet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 done:
 	cb->args[1] = i;
 	cb->args[2] = num;
-unlock:
+out:
+	;
+}
+
+static int __inet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
+		struct inet_diag_req *r, struct nlattr *bc)
+{
+	const struct inet_diag_handler *handler;
+
+	handler = inet_diag_lock_handler(r->sdiag_protocol);
+	if (!IS_ERR(handler))
+		inet_diag_dump_icsk(handler->idiag_hashinfo, skb, cb, r, bc);
 	inet_diag_unlock_handler(handler);
+
 	return skb->len;
 }