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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 2/3] bluetooth: 6lowpan: check neighbour table for SLAAC
Date: Tue, 12 Mar 2019 20:16:24 +0100
Message-ID: <20190312191626.20634-3-josua.mayer@jm0.eu> (raw)
In-Reply-To: <20190312191626.20634-1-josua.mayer@jm0.eu>

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.

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 | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
index 50530561da98..29a4f3d65348 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 +223,20 @@ 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;
-- 
2.21.0


  parent reply index

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-08 15:25 [PATCH 0/3] bluetooth: 6lowpan: multiple peers and addresses Josua Mayer
2019-02-08 15:25 ` [PATCH 1/3] bluetooth: 6lowpan: search for destination address in all peers Josua Mayer
2019-02-08 15:25 ` [PATCH 2/3] bluetooth: 6lowpan: check neighbour table for SLAAC Josua Mayer
2019-03-07 10:41   ` Johan Hedberg
2019-03-12 16:23     ` Josua Mayer
2019-02-08 15:25 ` [PATCH 3/3] bluetooth: 6lowpan: always check destination address Josua Mayer
2019-02-28 20:00 ` [PATCH 0/3] bluetooth: 6lowpan: multiple peers and addresses Josua Mayer
2019-02-28 20:30   ` Michael Scott
2019-03-06 18:10     ` Michael Scott
2019-03-07  9:16       ` Jukka Rissanen
2019-03-12 19:16 ` [PATCH v2 " Josua Mayer
2019-03-12 19:16   ` [PATCH v2 1/3] bluetooth: 6lowpan: search for destination address in all peers Josua Mayer
2019-03-12 19:16   ` Josua Mayer [this message]
2019-03-12 19:16   ` [PATCH v2 3/3] bluetooth: 6lowpan: always check destination address Josua Mayer
2019-03-30 15:51   ` [PATCH v2 0/3] bluetooth: 6lowpan: multiple peers and addresses Josua Mayer
2019-05-13 10:11   ` [PATCH RESEND v2 1/3] bluetooth: 6lowpan: search for destination address in all peers Josua Mayer
2019-05-13 10:12   ` [PATCH RESEND v2 3/3] bluetooth: 6lowpan: always check destination address Josua Mayer
2019-05-13 10:12   ` [PATCH RESEND v2 2/3] bluetooth: 6lowpan: check neighbour table for SLAAC Josua Mayer
2019-05-13 10:11 ` [PATCH RESEND v2 0/3] bluetooth: 6lowpan: multiple peers and addresses Josua Mayer

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