[PATCH AUTOSEL 5.1 207/219] Bluetooth: 6lowpan: search for destination address in all peers

Sasha Levin
2019-07-15T14:16:48Z

From: Josua Mayer <josua.mayer@jm0.eu>

[ Upstream commit b188b03270b7f8568fc714101ce82fbf5e811c5a ]

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>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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);

--
2.20.1