tipc: refactor message delivery out of tipc_rcv

This is a cosmetic change, separating message delivery from the
link state processing.

Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/link.c

@@ -88,6 +88,8 @@ static void link_print(struct tipc_link *l_ptr, const char *str);
 static int tipc_link_frag_xmit(struct tipc_link *l_ptr, struct sk_buff *buf);
 static void tipc_link_sync_xmit(struct tipc_link *l);
 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf);
+static int tipc_link_input(struct tipc_link *l, struct sk_buff *buf);
+static int tipc_link_prepare_input(struct tipc_link *l, struct sk_buff **buf);
 
 /*
  *  Simple link routines
@@ -1458,54 +1460,14 @@ void tipc_rcv(struct sk_buff *head, struct tipc_bearer *b_ptr)
 		if (unlikely(l_ptr->oldest_deferred_in))
 			head = link_insert_deferred_queue(l_ptr, head);
 
-		/* Deliver packet/message to correct user: */
-		if (unlikely(msg_user(msg) ==  CHANGEOVER_PROTOCOL)) {
-			if (!tipc_link_tunnel_rcv(n_ptr, &buf)) {
-				tipc_node_unlock(n_ptr);
-				continue;
-			}
-			msg = buf_msg(buf);
-		} else if (msg_user(msg) == MSG_FRAGMENTER) {
-			l_ptr->stats.recv_fragments++;
-			if (tipc_buf_append(&l_ptr->reasm_buf, &buf)) {
-				l_ptr->stats.recv_fragmented++;
-				msg = buf_msg(buf);
-			} else {
-				if (!l_ptr->reasm_buf)
-					tipc_link_reset(l_ptr);
-				tipc_node_unlock(n_ptr);
-				continue;
-			}
-		}
-
-		switch (msg_user(msg)) {
-		case TIPC_LOW_IMPORTANCE:
-		case TIPC_MEDIUM_IMPORTANCE:
-		case TIPC_HIGH_IMPORTANCE:
-		case TIPC_CRITICAL_IMPORTANCE:
-		case CONN_MANAGER:
-			tipc_node_unlock(n_ptr);
-			tipc_sk_rcv(buf);
-			continue;
-		case MSG_BUNDLER:
-			l_ptr->stats.recv_bundles++;
-			l_ptr->stats.recv_bundled += msg_msgcnt(msg);
+		if (tipc_link_prepare_input(l_ptr, &buf)) {
 			tipc_node_unlock(n_ptr);
-			tipc_link_bundle_rcv(buf);
 			continue;
-		case NAME_DISTRIBUTOR:
-			n_ptr->bclink.recv_permitted = true;
-			tipc_node_unlock(n_ptr);
-			tipc_named_rcv(buf);
-			continue;
-		case BCAST_PROTOCOL:
-			tipc_link_sync_rcv(n_ptr, buf);
-			break;
-		default:
-			kfree_skb(buf);
-			break;
 		}
 		tipc_node_unlock(n_ptr);
+		msg = buf_msg(buf);
+		if (tipc_link_input(l_ptr, buf) != 0)
+			goto discard;
 		continue;
 unlock_discard:
 		tipc_node_unlock(n_ptr);
@@ -1514,6 +1476,80 @@ void tipc_rcv(struct sk_buff *head, struct tipc_bearer *b_ptr)
 	}
 }
 
+/**
+ * tipc_link_prepare_input - process TIPC link messages
+ *
+ * returns nonzero if the message was consumed
+ *
+ * Node lock must be held
+ */
+static int tipc_link_prepare_input(struct tipc_link *l, struct sk_buff **buf)
+{
+	struct tipc_node *n;
+	struct tipc_msg *msg;
+	int res = -EINVAL;
+
+	n = l->owner;
+	msg = buf_msg(*buf);
+	switch (msg_user(msg)) {
+	case CHANGEOVER_PROTOCOL:
+		if (tipc_link_tunnel_rcv(n, buf))
+			res = 0;
+		break;
+	case MSG_FRAGMENTER:
+		l->stats.recv_fragments++;
+		if (tipc_buf_append(&l->reasm_buf, buf)) {
+			l->stats.recv_fragmented++;
+			res = 0;
+		} else if (!l->reasm_buf) {
+			tipc_link_reset(l);
+		}
+		break;
+	case MSG_BUNDLER:
+		l->stats.recv_bundles++;
+		l->stats.recv_bundled += msg_msgcnt(msg);
+		res = 0;
+		break;
+	case NAME_DISTRIBUTOR:
+		n->bclink.recv_permitted = true;
+		res = 0;
+		break;
+	case BCAST_PROTOCOL:
+		tipc_link_sync_rcv(n, *buf);
+		break;
+	default:
+		res = 0;
+	}
+	return res;
+}
+/**
+ * tipc_link_input - Deliver message too higher layers
+ */
+static int tipc_link_input(struct tipc_link *l, struct sk_buff *buf)
+{
+	struct tipc_msg *msg = buf_msg(buf);
+	int res = 0;
+
+	switch (msg_user(msg)) {
+	case TIPC_LOW_IMPORTANCE:
+	case TIPC_MEDIUM_IMPORTANCE:
+	case TIPC_HIGH_IMPORTANCE:
+	case TIPC_CRITICAL_IMPORTANCE:
+	case CONN_MANAGER:
+		tipc_sk_rcv(buf);
+		break;
+	case NAME_DISTRIBUTOR:
+		tipc_named_rcv(buf);
+		break;
+	case MSG_BUNDLER:
+		tipc_link_bundle_rcv(buf);
+		break;
+	default:
+		res = -EINVAL;
+	}
+	return res;
+}
+
 /**
  * tipc_link_defer_pkt - Add out-of-sequence message to deferred reception queue
  *