[PATCHv4 net-next 01/12] 6lowpan: add private neighbour data

[Alexander Aring]

This patch will introduce a 6lowpan neighbour private data. Like the
interface private data we handle private data for generic 6lowpan and
for link-layer specific 6lowpan.

The current first use case if to save the short address for a 802.15.4
6lowpan neighbour.

Cc: David S. Miller <da...@davemloft.net>
Reviewed-by: Stefan Schmidt <ste...@osg.samsung.com>
Acked-by: YOSHIFUJI Hideaki <yoshf...@linux-ipv6.org>
Signed-off-by: Alexander Aring <a...@pengutronix.de>
---
 include/linux/netdevice.h     |  3 +--
 include/net/6lowpan.h         | 10 ++++++++++
 net/ieee802154/6lowpan/core.c | 12 ++++++++++++
 3 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index d101e4d..36e43bd 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1483,8 +1483,7 @@ enum netdev_priv_flags {
  *     @perm_addr:             Permanent hw address
  *     @addr_assign_type:      Hw address assignment type
  *     @addr_len:              Hardware address length
- *     @neigh_priv_len;        Used in neigh_alloc(),
- *                             initialized only in atm/clip.c
+ *     @neigh_priv_len:        Used in neigh_alloc()
  *     @dev_id:                Used to differentiate devices that share
  *                             the same link layer address
  *     @dev_port:              Used to differentiate devices that share
diff --git a/include/net/6lowpan.h b/include/net/6lowpan.h
index da84cf9..2d9b9d3 100644
--- a/include/net/6lowpan.h
+++ b/include/net/6lowpan.h
@@ -141,6 +141,16 @@ struct lowpan_dev {
        u8 priv[0] __aligned(sizeof(void *));
 };
 
+struct lowpan_802154_neigh {
+       __le16 short_addr;
+};
+
+static inline
+struct lowpan_802154_neigh *lowpan_802154_neigh(void *neigh_priv)
+{
+       return neigh_priv;
+}
+
 static inline
 struct lowpan_dev *lowpan_dev(const struct net_device *dev)
 {
diff --git a/net/ieee802154/6lowpan/core.c b/net/ieee802154/6lowpan/core.c
index 4e2b308..8c004a0 100644
--- a/net/ieee802154/6lowpan/core.c
+++ b/net/ieee802154/6lowpan/core.c
@@ -81,11 +81,21 @@ static int lowpan_stop(struct net_device *dev)
        return 0;
 }
 
+static int lowpan_neigh_construct(struct neighbour *n)
+{
+       struct lowpan_802154_neigh *neigh = 
lowpan_802154_neigh(neighbour_priv(n));
+
+       /* default no short_addr is available for a neighbour */
+       neigh->short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC);
+       return 0;
+}
+
 static const struct net_device_ops lowpan_netdev_ops = {
        .ndo_init               = lowpan_dev_init,
        .ndo_start_xmit         = lowpan_xmit,
        .ndo_open               = lowpan_open,
        .ndo_stop               = lowpan_stop,
+       .ndo_neigh_construct    = lowpan_neigh_construct,
 };
 
 static void lowpan_setup(struct net_device *ldev)
@@ -150,6 +160,8 @@ static int lowpan_newlink(struct net *src_net, struct 
net_device *ldev,
                                wdev->needed_headroom;
        ldev->needed_tailroom = wdev->needed_tailroom;
 
+       ldev->neigh_priv_len = sizeof(struct lowpan_802154_neigh);
+
        ret = lowpan_register_netdevice(ldev, LOWPAN_LLTYPE_IEEE802154);
        if (ret < 0) {
                dev_put(wdev);
-- 
2.8.3