[RFCv2 bluetooth-next 2/2] 6lowpan: add generic 6lowpan netdev private data

[Alexander Aring <alex.aring@gmail.com>]

This patch introduced the 6lowpan netdev private data struct. We name it
lowpan_priv and it's placed at the beginning of netdev private data. All
lowpan interfaces should allocate this room at first of netdev private
data. 6LoWPAN LL private data can be allocate by additional netdev private
data, e.g. dev->priv_size should be "sizeof(struct lowpan_priv) +
sizeof(LL_LOWPAN_PRIVATE_DATA)".

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
---
 include/net/6lowpan.h              | 18 ++++++++++++++++++
 net/bluetooth/6lowpan.c            |  7 +++++--
 net/ieee802154/6lowpan/6lowpan_i.h |  3 ++-
 net/ieee802154/6lowpan/core.c      |  5 ++++-
 4 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/include/net/6lowpan.h b/include/net/6lowpan.h
index dc03d77..a955be2 100644
--- a/include/net/6lowpan.h
+++ b/include/net/6lowpan.h
@@ -197,6 +197,24 @@
 #define LOWPAN_NHC_UDP_CS_P_11	0xF3 /* source & dest = 0xF0B + 4bit inline */
 #define LOWPAN_NHC_UDP_CS_C	0x04 /* checksum elided */
 
+enum lowpan_ll_types {
+	LOWPAN_LL_TYPE_BTLE,
+	LOWPAN_LL_TYPE_IEEE802154,
+};
+
+struct lowpan_priv {
+	enum lowpan_ll_types ll_type;
+
+	/* must be last */
+	u8 priv[0] __aligned(sizeof(void *));
+};
+
+static inline
+struct lowpan_priv *lowpan_priv(const struct net_device *dev)
+{
+	return netdev_priv(dev);
+}
+
 #ifdef DEBUG
 /* print data in line */
 static inline void raw_dump_inline(const char *caller, char *msg,
diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
index 24ed5b0..eb61121 100644
--- a/net/bluetooth/6lowpan.c
+++ b/net/bluetooth/6lowpan.c
@@ -85,7 +85,7 @@ struct lowpan_dev {
 
 static inline struct lowpan_dev *lowpan_dev(const struct net_device *netdev)
 {
-	return netdev_priv(netdev);
+	return (struct lowpan_dev *)lowpan_priv(netdev)->priv;
 }
 
 static inline void peer_add(struct lowpan_dev *dev, struct lowpan_peer *peer)
@@ -848,7 +848,8 @@ static int setup_netdev(struct l2cap_chan *chan, struct lowpan_dev **dev)
 	struct net_device *netdev;
 	int err = 0;
 
-	netdev = alloc_netdev(sizeof(struct lowpan_dev), IFACE_NAME_TEMPLATE,
+	netdev = alloc_netdev(sizeof(struct lowpan_priv) +
+			      sizeof(struct lowpan_dev), IFACE_NAME_TEMPLATE,
 			      NET_NAME_UNKNOWN, netdev_setup);
 	if (!netdev)
 		return -ENOMEM;
@@ -869,6 +870,8 @@ static int setup_netdev(struct l2cap_chan *chan, struct lowpan_dev **dev)
 	list_add_rcu(&(*dev)->list, &bt_6lowpan_devices);
 	spin_unlock(&devices_lock);
 
+	lowpan_priv(netdev)->ll_type = LOWPAN_LL_TYPE_BTLE;
+
 	err = register_netdev(netdev);
 	if (err < 0) {
 		BT_INFO("register_netdev failed %d", err);
diff --git a/net/ieee802154/6lowpan/6lowpan_i.h b/net/ieee802154/6lowpan/6lowpan_i.h
index e50f69d..0dd4e46 100644
--- a/net/ieee802154/6lowpan/6lowpan_i.h
+++ b/net/ieee802154/6lowpan/6lowpan_i.h
@@ -5,6 +5,7 @@
 
 #include <net/ieee802154_netdev.h>
 #include <net/inet_frag.h>
+#include <net/6lowpan.h>
 
 struct lowpan_create_arg {
 	u16 tag;
@@ -52,7 +53,7 @@ struct lowpan_dev_info {
 static inline struct
 lowpan_dev_info *lowpan_dev_info(const struct net_device *dev)
 {
-	return netdev_priv(dev);
+	return (struct lowpan_dev_info *)lowpan_priv(dev)->priv;
 }
 
 extern struct list_head lowpan_devices;
diff --git a/net/ieee802154/6lowpan/core.c b/net/ieee802154/6lowpan/core.c
index f20a387..ede602c 100644
--- a/net/ieee802154/6lowpan/core.c
+++ b/net/ieee802154/6lowpan/core.c
@@ -153,6 +153,8 @@ static int lowpan_newlink(struct net *src_net, struct net_device *dev,
 	list_add_tail(&entry->list, &lowpan_devices);
 	mutex_unlock(&lowpan_dev_info(dev)->dev_list_mtx);
 
+	lowpan_priv(dev)->ll_type = LOWPAN_LL_TYPE_IEEE802154;
+
 	ret = register_netdevice(dev);
 	if (ret >= 0) {
 		if (!lowpan_open_count)
@@ -193,7 +195,8 @@ static void lowpan_dellink(struct net_device *dev, struct list_head *head)
 
 static struct rtnl_link_ops lowpan_link_ops __read_mostly = {
 	.kind		= "lowpan",
-	.priv_size	= sizeof(struct lowpan_dev_info),
+	.priv_size	= sizeof(struct lowpan_priv) +
+			  sizeof(struct lowpan_dev_info),
 	.setup		= lowpan_setup,
 	.newlink	= lowpan_newlink,
 	.dellink	= lowpan_dellink,
-- 
2.5.0