1 files changed, 28 insertions, 26 deletions

diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
index a7cd23f00bde..9d41de1ec90f 100644
--- a/net/bluetooth/6lowpan.c
+++ b/net/bluetooth/6lowpan.c
@@ -1,14 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
    Copyright (c) 2013-2014 Intel Corp.
 
-   This program is free software; you can redistribute it and/or modify
-   it under the terms of the GNU General Public License version 2 and
-   only version 2 as published by the Free Software Foundation.
-
-   This program is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-   GNU General Public License for more details.
 */
 
 #include <linux/if_arp.h>
@@ -167,30 +160,25 @@ static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_btle_dev *dev,
 						  struct in6_addr *daddr,
 						  struct sk_buff *skb)
 {
-	struct lowpan_peer *peer;
-	struct in6_addr *nexthop;
 	struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
 	int count = atomic_read(&dev->peer_count);
+	const struct in6_addr *nexthop;
+	struct lowpan_peer *peer;
+	struct neighbour *neigh;
 
 	BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt);
 
-	/* If we have multiple 6lowpan peers, then check where we should
-	 * send the packet. If only one peer exists, then we can send the
-	 * packet right away.
-	 */
-	if (count == 1) {
-		rcu_read_lock();
-		peer = list_first_or_null_rcu(&dev->peers, struct lowpan_peer,
-					      list);
-		rcu_read_unlock();
-		return peer;
-	}
-
 	if (!rt) {
-		nexthop = &lowpan_cb(skb)->gw;
-
-		if (ipv6_addr_any(nexthop))
-			return NULL;
+		if (ipv6_addr_any(&lowpan_cb(skb)->gw)) {
+			/* There is neither route nor gateway,
+			 * probably the destination is a direct peer.
+			 */
+			nexthop = daddr;
+		} else {
+			/* There is a known gateway
+			 */
+			nexthop = &lowpan_cb(skb)->gw;
+		}
 	} else {
 		nexthop = rt6_nexthop(rt, daddr);
 
@@ -216,6 +204,20 @@ static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_btle_dev *dev,
 		}
 	}
 
+	/* use the neighbour cache for matching addresses assigned by SLAAC
+	*/
+	neigh = __ipv6_neigh_lookup(dev->netdev, nexthop);
+	if (neigh) {
+		list_for_each_entry_rcu(peer, &dev->peers, list) {
+			if (!memcmp(neigh->ha, peer->lladdr, ETH_ALEN)) {
+				neigh_release(neigh);
+				rcu_read_unlock();
+				return peer;
+			}
+		}
+		neigh_release(neigh);
+	}
+
 	rcu_read_unlock();
 
 	return NULL;