From:   Josua Mayer <josua.mayer@jm0.eu>
To:     linux-bluetooth@vger.kernel.org
Cc:     Josua Mayer <josua.mayer@jm0.eu>,
        Jukka Rissanen <jukka.rissanen@linux.intel.com>,
        Michael Scott <mike@foundries.io>,
        Marcel Holtmann <marcel@holtmann.org>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        "David S. Miller" <davem@davemloft.net>
Subject: [PATCH v2 1/3] bluetooth: 6lowpan: search for destination address in all peers
Date:   Tue, 12 Mar 2019 20:16:23 +0100
Message-Id: <20190312191626.20634-2-josua.mayer@jm0.eu>
In-Reply-To: <20190312191626.20634-1-josua.mayer@jm0.eu>
References: <20190208152519.16181-1-josua.mayer@jm0.eu>
 <20190312191626.20634-1-josua.mayer@jm0.eu>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-bluetooth-owner@vger.kernel.org
Precedence: bulk

Handle overlooked case where the target address is assigned to a peer
and neither route nor gateway exist.

For one peer, no checks are performed to see if it is meant to receive
packets for a given address.

As soon as there is a second peer however, checks are performed
to deal with routes and gateways for handling complex setups with
multiple hops to a target address.
This logic assumed that no route and no gateway imply that the
destination address can not be reached, which is false in case of a
direct peer.

Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Tested-by: Michael Scott <mike@foundries.io>
Signed-off-by: Josua Mayer <josua.mayer@jm0.eu>
---
 net/bluetooth/6lowpan.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
index a7cd23f00bde..50530561da98 100644
--- a/net/bluetooth/6lowpan.c
+++ b/net/bluetooth/6lowpan.c
@@ -187,10 +187,16 @@ static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_btle_dev *dev,
 	}
 
 	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);
 
-- 
2.21.0