1 files changed, 44 insertions, 28 deletions

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 26aec84..6666680 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -776,44 +776,60 @@ new_mtu:
 	return rc;
 }
 
-/* tipc_sk_mcast_rcv - Deliver multicast message to all destination sockets
+/**
+ * tipc_sk_mcast_rcv - Deliver multicast messages to all destination sockets
+ * @arrvq: queue with arriving messages, to be cloned after destination lookup
+ * @inputq: queue with cloned messages, delivered to socket after dest lookup
+ *
+ * Multi-threaded: parallel calls with reference to same queues may occur
  */
-void tipc_sk_mcast_rcv(struct net *net, struct sk_buff *skb)
+void tipc_sk_mcast_rcv(struct net *net, struct sk_buff_head *arrvq,
+		       struct sk_buff_head *inputq)
 {
-	struct tipc_msg *msg = buf_msg(skb);
+	struct tipc_msg *msg;
 	struct tipc_plist dports;
-	struct sk_buff *cskb;
 	u32 portid;
 	u32 scope = TIPC_CLUSTER_SCOPE;
-	struct sk_buff_head msgq;
-	uint hsz = skb_headroom(skb) + msg_hdr_sz(msg);
+	struct sk_buff_head tmpq;
+	uint hsz;
+	struct sk_buff *skb, *_skb;
 
-	skb_queue_head_init(&msgq);
+	__skb_queue_head_init(&tmpq);
 	tipc_plist_init(&dports);
 
-	if (in_own_node(net, msg_orignode(msg)))
-		scope = TIPC_NODE_SCOPE;
-
-	if (unlikely(!msg_mcast(msg))) {
-		pr_warn("Received non-multicast msg in multicast\n");
-		goto exit;
-	}
-	/* Create destination port list: */
-	tipc_nametbl_mc_translate(net, msg_nametype(msg), msg_namelower(msg),
-				  msg_nameupper(msg), scope, &dports);
-	portid = tipc_plist_pop(&dports);
-	for (; portid; portid = tipc_plist_pop(&dports)) {
-		cskb = __pskb_copy(skb, hsz, GFP_ATOMIC);
-		if (!cskb) {
-			pr_warn("Failed do clone mcast rcv buffer\n");
-			continue;
+	skb = tipc_skb_peek(arrvq, &inputq->lock);
+	for (; skb; skb = tipc_skb_peek(arrvq, &inputq->lock)) {
+		msg = buf_msg(skb);
+		hsz = skb_headroom(skb) + msg_hdr_sz(msg);
+
+		if (in_own_node(net, msg_orignode(msg)))
+			scope = TIPC_NODE_SCOPE;
+
+		/* Create destination port list and message clones: */
+		tipc_nametbl_mc_translate(net,
+					  msg_nametype(msg), msg_namelower(msg),
+					  msg_nameupper(msg), scope, &dports);
+		portid = tipc_plist_pop(&dports);
+		for (; portid; portid = tipc_plist_pop(&dports)) {
+			_skb = __pskb_copy(skb, hsz, GFP_ATOMIC);
+			if (_skb) {
+				msg_set_destport(buf_msg(_skb), portid);
+				__skb_queue_tail(&tmpq, _skb);
+				continue;
+			}
+			pr_warn("Failed to clone mcast rcv buffer\n");
 		}
-		msg_set_destport(buf_msg(cskb), portid);
-		skb_queue_tail(&msgq, cskb);
+		/* Append to inputq if not already done by other thread */
+		spin_lock_bh(&inputq->lock);
+		if (skb_peek(arrvq) == skb) {
+			skb_queue_splice_tail_init(&tmpq, inputq);
+			kfree_skb(__skb_dequeue(arrvq));
+		}
+		spin_unlock_bh(&inputq->lock);
+		__skb_queue_purge(&tmpq);
+		kfree_skb(skb);
 	}
-	tipc_sk_rcv(net, &msgq);
-exit:
-	kfree_skb(skb);
+	tipc_sk_rcv(net, inputq);
 }
 
 /**