Like any IPv6 capable device, 6LNs can have multiple addresses assigned
using SLAAC and made known through neighbour advertisements.
After checking the destination address against all peers link-local
addresses, consult the neighbour cache for additional known addresses.
RFC7668 defines the scope of Neighbor Advertisements in Section 3.2.3:
1. "A Bluetooth LE 6LN MUST NOT register its link-local address"
2. "A Bluetooth LE 6LN MUST register its non-link-local addresses with
the 6LBR by sending Neighbor Solicitation (NS) messages ..."
Due to these constranits both the link-local addresses tracked in the
list of 6lowpan peers, and the neighbour cache have to be used when
identifying the 6lowpan peer for a destination address.
Signed-off-by: Josua Mayer <josua.mayer@xxxxxx>
---
net/bluetooth/6lowpan.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
index 553dc719afde..4e14db230793 100644
--- a/net/bluetooth/6lowpan.c
+++ b/net/bluetooth/6lowpan.c
@@ -171,6 +171,7 @@ static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_btle_dev *dev,
struct in6_addr *nexthop;
struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
int count = atomic_read(&dev->peer_count);
+ struct neighbour *neigh;
BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt);
@@ -222,6 +223,19 @@ static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_btle_dev *dev,
}
}
+ // use the neighbout 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;
--
2.20.1
