Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 1469 insertions, 0 deletions

diff --git a/kernel/net/bluetooth/6lowpan.c b/kernel/net/bluetooth/6lowpan.c
new file mode 100644
index 000000000..1742b849f
--- /dev/null
+++ b/kernel/net/bluetooth/6lowpan.c
@@ -0,0 +1,1469 @@
+/*
+   Copyright (c) 2013-2014 Intel Corp.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License version 2 and
+   only version 2 as published by the Free Software Foundation.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+*/
+
+#include <linux/if_arp.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/module.h>
+#include <linux/debugfs.h>
+
+#include <net/ipv6.h>
+#include <net/ip6_route.h>
+#include <net/addrconf.h>
+
+#include <net/af_ieee802154.h> /* to get the address type */
+
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+#include <net/bluetooth/l2cap.h>
+
+#include <net/6lowpan.h> /* for the compression support */
+
+#define VERSION "0.1"
+
+static struct dentry *lowpan_enable_debugfs;
+static struct dentry *lowpan_control_debugfs;
+
+#define IFACE_NAME_TEMPLATE "bt%d"
+#define EUI64_ADDR_LEN 8
+
+struct skb_cb {
+	struct in6_addr addr;
+	struct in6_addr gw;
+	struct l2cap_chan *chan;
+	int status;
+};
+#define lowpan_cb(skb) ((struct skb_cb *)((skb)->cb))
+
+/* The devices list contains those devices that we are acting
+ * as a proxy. The BT 6LoWPAN device is a virtual device that
+ * connects to the Bluetooth LE device. The real connection to
+ * BT device is done via l2cap layer. There exists one
+ * virtual device / one BT 6LoWPAN network (=hciX device).
+ * The list contains struct lowpan_dev elements.
+ */
+static LIST_HEAD(bt_6lowpan_devices);
+static DEFINE_SPINLOCK(devices_lock);
+
+static bool enable_6lowpan;
+
+/* We are listening incoming connections via this channel
+ */
+static struct l2cap_chan *listen_chan;
+
+struct lowpan_peer {
+	struct list_head list;
+	struct rcu_head rcu;
+	struct l2cap_chan *chan;
+
+	/* peer addresses in various formats */
+	unsigned char eui64_addr[EUI64_ADDR_LEN];
+	struct in6_addr peer_addr;
+};
+
+struct lowpan_dev {
+	struct list_head list;
+
+	struct hci_dev *hdev;
+	struct net_device *netdev;
+	struct list_head peers;
+	atomic_t peer_count; /* number of items in peers list */
+
+	struct work_struct delete_netdev;
+	struct delayed_work notify_peers;
+};
+
+static inline struct lowpan_dev *lowpan_dev(const struct net_device *netdev)
+{
+	return netdev_priv(netdev);
+}
+
+static inline void peer_add(struct lowpan_dev *dev, struct lowpan_peer *peer)
+{
+	list_add_rcu(&peer->list, &dev->peers);
+	atomic_inc(&dev->peer_count);
+}
+
+static inline bool peer_del(struct lowpan_dev *dev, struct lowpan_peer *peer)
+{
+	list_del_rcu(&peer->list);
+	kfree_rcu(peer, rcu);
+
+	module_put(THIS_MODULE);
+
+	if (atomic_dec_and_test(&dev->peer_count)) {
+		BT_DBG("last peer");
+		return true;
+	}
+
+	return false;
+}
+
+static inline struct lowpan_peer *peer_lookup_ba(struct lowpan_dev *dev,
+						 bdaddr_t *ba, __u8 type)
+{
+	struct lowpan_peer *peer;
+
+	BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count),
+	       ba, type);
+
+	rcu_read_lock();
+
+	list_for_each_entry_rcu(peer, &dev->peers, list) {
+		BT_DBG("dst addr %pMR dst type %d",
+		       &peer->chan->dst, peer->chan->dst_type);
+
+		if (bacmp(&peer->chan->dst, ba))
+			continue;
+
+		if (type == peer->chan->dst_type) {
+			rcu_read_unlock();
+			return peer;
+		}
+	}
+
+	rcu_read_unlock();
+
+	return NULL;
+}
+
+static inline struct lowpan_peer *__peer_lookup_chan(struct lowpan_dev *dev,
+						     struct l2cap_chan *chan)
+{
+	struct lowpan_peer *peer;
+
+	list_for_each_entry_rcu(peer, &dev->peers, list) {
+		if (peer->chan == chan)
+			return peer;
+	}
+
+	return NULL;
+}
+
+static inline struct lowpan_peer *__peer_lookup_conn(struct lowpan_dev *dev,
+						     struct l2cap_conn *conn)
+{
+	struct lowpan_peer *peer;
+
+	list_for_each_entry_rcu(peer, &dev->peers, list) {
+		if (peer->chan->conn == conn)
+			return peer;
+	}
+
+	return NULL;
+}
+
+static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_dev *dev,
+						  struct in6_addr *daddr,
+						  struct sk_buff *skb)
+{
+	struct lowpan_peer *peer;
+	struct in6_addr *nexthop;
+	struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
+	int count = atomic_read(&dev->peer_count);
+
+	BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt);
+
+	/* If we have multiple 6lowpan peers, then check where we should
+	 * send the packet. If only one peer exists, then we can send the
+	 * packet right away.
+	 */
+	if (count == 1) {
+		rcu_read_lock();
+		peer = list_first_or_null_rcu(&dev->peers, struct lowpan_peer,
+					      list);
+		rcu_read_unlock();
+		return peer;
+	}
+
+	if (!rt) {
+		nexthop = &lowpan_cb(skb)->gw;
+
+		if (ipv6_addr_any(nexthop))
+			return NULL;
+	} else {
+		nexthop = rt6_nexthop(rt);
+
+		/* We need to remember the address because it is needed
+		 * by bt_xmit() when sending the packet. In bt_xmit(), the
+		 * destination routing info is not set.
+		 */
+		memcpy(&lowpan_cb(skb)->gw, nexthop, sizeof(struct in6_addr));
+	}
+
+	BT_DBG("gw %pI6c", nexthop);
+
+	rcu_read_lock();
+
+	list_for_each_entry_rcu(peer, &dev->peers, list) {
+		BT_DBG("dst addr %pMR dst type %d ip %pI6c",
+		       &peer->chan->dst, peer->chan->dst_type,
+		       &peer->peer_addr);
+
+		if (!ipv6_addr_cmp(&peer->peer_addr, nexthop)) {
+			rcu_read_unlock();
+			return peer;
+		}
+	}
+
+	rcu_read_unlock();
+
+	return NULL;
+}
+
+static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn)
+{
+	struct lowpan_dev *entry;
+	struct lowpan_peer *peer = NULL;
+
+	rcu_read_lock();
+
+	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
+		peer = __peer_lookup_conn(entry, conn);
+		if (peer)
+			break;
+	}
+
+	rcu_read_unlock();
+
+	return peer;
+}
+
+static struct lowpan_dev *lookup_dev(struct l2cap_conn *conn)
+{
+	struct lowpan_dev *entry;
+	struct lowpan_dev *dev = NULL;
+
+	rcu_read_lock();
+
+	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
+		if (conn->hcon->hdev == entry->hdev) {
+			dev = entry;
+			break;
+		}
+	}
+
+	rcu_read_unlock();
+
+	return dev;
+}
+
+static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev)
+{
+	struct sk_buff *skb_cp;
+
+	skb_cp = skb_copy(skb, GFP_ATOMIC);
+	if (!skb_cp)
+		return NET_RX_DROP;
+
+	return netif_rx(skb_cp);
+}
+
+static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev,
+			   struct l2cap_chan *chan)
+{
+	const u8 *saddr, *daddr;
+	u8 iphc0, iphc1;
+	struct lowpan_dev *dev;
+	struct lowpan_peer *peer;
+
+	dev = lowpan_dev(netdev);
+
+	rcu_read_lock();
+	peer = __peer_lookup_chan(dev, chan);
+	rcu_read_unlock();
+	if (!peer)
+		return -EINVAL;
+
+	saddr = peer->eui64_addr;
+	daddr = dev->netdev->dev_addr;
+
+	/* at least two bytes will be used for the encoding */
+	if (skb->len < 2)
+		return -EINVAL;
+
+	if (lowpan_fetch_skb_u8(skb, &iphc0))
+		return -EINVAL;
+
+	if (lowpan_fetch_skb_u8(skb, &iphc1))
+		return -EINVAL;
+
+	return lowpan_header_decompress(skb, netdev,
+					saddr, IEEE802154_ADDR_LONG,
+					EUI64_ADDR_LEN, daddr,
+					IEEE802154_ADDR_LONG, EUI64_ADDR_LEN,
+					iphc0, iphc1);
+
+}
+
+static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
+		    struct l2cap_chan *chan)
+{
+	struct sk_buff *local_skb;
+	int ret;
+
+	if (!netif_running(dev))
+		goto drop;
+
+	if (dev->type != ARPHRD_6LOWPAN)
+		goto drop;
+
+	skb = skb_share_check(skb, GFP_ATOMIC);
+	if (!skb)
+		goto drop;
+
+	/* check that it's our buffer */
+	if (skb->data[0] == LOWPAN_DISPATCH_IPV6) {
+		/* Copy the packet so that the IPv6 header is
+		 * properly aligned.
+		 */
+		local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
+					    skb_tailroom(skb), GFP_ATOMIC);
+		if (!local_skb)
+			goto drop;
+
+		local_skb->protocol = htons(ETH_P_IPV6);
+		local_skb->pkt_type = PACKET_HOST;
+
+		skb_reset_network_header(local_skb);
+		skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
+
+		if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) {
+			kfree_skb(local_skb);
+			goto drop;
+		}
+
+		dev->stats.rx_bytes += skb->len;
+		dev->stats.rx_packets++;
+
+		consume_skb(local_skb);
+		consume_skb(skb);
+	} else {
+		switch (skb->data[0] & 0xe0) {
+		case LOWPAN_DISPATCH_IPHC:	/* ipv6 datagram */
+			local_skb = skb_clone(skb, GFP_ATOMIC);
+			if (!local_skb)
+				goto drop;
+
+			ret = iphc_decompress(local_skb, dev, chan);
+			if (ret < 0) {
+				kfree_skb(local_skb);
+				goto drop;
+			}
+
+			local_skb->protocol = htons(ETH_P_IPV6);
+			local_skb->pkt_type = PACKET_HOST;
+			local_skb->dev = dev;
+
+			if (give_skb_to_upper(local_skb, dev)
+					!= NET_RX_SUCCESS) {
+				kfree_skb(local_skb);
+				goto drop;
+			}
+
+			dev->stats.rx_bytes += skb->len;
+			dev->stats.rx_packets++;
+
+			consume_skb(local_skb);
+			consume_skb(skb);
+			break;
+		default:
+			break;
+		}
+	}
+
+	return NET_RX_SUCCESS;
+
+drop:
+	dev->stats.rx_dropped++;
+	return NET_RX_DROP;
+}
+
+/* Packet from BT LE device */
+static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
+{
+	struct lowpan_dev *dev;
+	struct lowpan_peer *peer;
+	int err;
+
+	peer = lookup_peer(chan->conn);
+	if (!peer)
+		return -ENOENT;
+
+	dev = lookup_dev(chan->conn);
+	if (!dev || !dev->netdev)
+		return -ENOENT;
+
+	err = recv_pkt(skb, dev->netdev, chan);
+	if (err) {
+		BT_DBG("recv pkt %d", err);
+		err = -EAGAIN;
+	}
+
+	return err;
+}
+
+static u8 get_addr_type_from_eui64(u8 byte)
+{
+	/* Is universal(0) or local(1) bit */
+	return ((byte & 0x02) ? BDADDR_LE_RANDOM : BDADDR_LE_PUBLIC);
+}
+
+static void copy_to_bdaddr(struct in6_addr *ip6_daddr, bdaddr_t *addr)
+{
+	u8 *eui64 = ip6_daddr->s6_addr + 8;
+
+	addr->b[0] = eui64[7];
+	addr->b[1] = eui64[6];
+	addr->b[2] = eui64[5];
+	addr->b[3] = eui64[2];
+	addr->b[4] = eui64[1];
+	addr->b[5] = eui64[0];
+}
+
+static void convert_dest_bdaddr(struct in6_addr *ip6_daddr,
+				bdaddr_t *addr, u8 *addr_type)
+{
+	copy_to_bdaddr(ip6_daddr, addr);
+
+	/* We need to toggle the U/L bit that we got from IPv6 address
+	 * so that we get the proper address and type of the BD address.
+	 */
+	addr->b[5] ^= 0x02;
+
+	*addr_type = get_addr_type_from_eui64(addr->b[5]);
+}
+
+static int setup_header(struct sk_buff *skb, struct net_device *netdev,
+			bdaddr_t *peer_addr, u8 *peer_addr_type)
+{
+	struct in6_addr ipv6_daddr;
+	struct lowpan_dev *dev;
+	struct lowpan_peer *peer;
+	bdaddr_t addr, *any = BDADDR_ANY;
+	u8 *daddr = any->b;
+	int err, status = 0;
+
+	dev = lowpan_dev(netdev);
+
+	memcpy(&ipv6_daddr, &lowpan_cb(skb)->addr, sizeof(ipv6_daddr));
+
+	if (ipv6_addr_is_multicast(&ipv6_daddr)) {
+		lowpan_cb(skb)->chan = NULL;
+	} else {
+		u8 addr_type;
+
+		/* Get destination BT device from skb.
+		 * If there is no such peer then discard the packet.
+		 */
+		convert_dest_bdaddr(&ipv6_daddr, &addr, &addr_type);
+
+		BT_DBG("dest addr %pMR type %d IP %pI6c", &addr,
+		       addr_type, &ipv6_daddr);
+
+		peer = peer_lookup_ba(dev, &addr, addr_type);
+		if (!peer) {
+			/* The packet might be sent to 6lowpan interface
+			 * because of routing (either via default route
+			 * or user set route) so get peer according to
+			 * the destination address.
+			 */
+			peer = peer_lookup_dst(dev, &ipv6_daddr, skb);
+			if (!peer) {
+				BT_DBG("no such peer %pMR found", &addr);
+				return -ENOENT;
+			}
+		}
+
+		daddr = peer->eui64_addr;
+		*peer_addr = addr;
+		*peer_addr_type = addr_type;
+		lowpan_cb(skb)->chan = peer->chan;
+
+		status = 1;
+	}
+
+	lowpan_header_compress(skb, netdev, ETH_P_IPV6, daddr,
+			       dev->netdev->dev_addr, skb->len);
+
+	err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0);
+	if (err < 0)
+		return err;
+
+	return status;
+}
+
+static int header_create(struct sk_buff *skb, struct net_device *netdev,
+			 unsigned short type, const void *_daddr,
+			 const void *_saddr, unsigned int len)
+{
+	struct ipv6hdr *hdr;
+
+	if (type != ETH_P_IPV6)
+		return -EINVAL;
+
+	hdr = ipv6_hdr(skb);
+
+	memcpy(&lowpan_cb(skb)->addr, &hdr->daddr, sizeof(struct in6_addr));
+
+	return 0;
+}
+
+/* Packet to BT LE device */
+static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb,
+		    struct net_device *netdev)
+{
+	struct msghdr msg;
+	struct kvec iv;
+	int err;
+
+	/* Remember the skb so that we can send EAGAIN to the caller if
+	 * we run out of credits.
+	 */
+	chan->data = skb;
+
+	iv.iov_base = skb->data;
+	iv.iov_len = skb->len;
+
+	memset(&msg, 0, sizeof(msg));
+	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, &iv, 1, skb->len);
+
+	err = l2cap_chan_send(chan, &msg, skb->len);
+	if (err > 0) {
+		netdev->stats.tx_bytes += err;
+		netdev->stats.tx_packets++;
+		return 0;
+	}
+
+	if (!err)
+		err = lowpan_cb(skb)->status;
+
+	if (err < 0) {
+		if (err == -EAGAIN)
+			netdev->stats.tx_dropped++;
+		else
+			netdev->stats.tx_errors++;
+	}
+
+	return err;
+}
+
+static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev)
+{
+	struct sk_buff *local_skb;
+	struct lowpan_dev *entry;
+	int err = 0;
+
+	rcu_read_lock();
+
+	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
+		struct lowpan_peer *pentry;
+		struct lowpan_dev *dev;
+
+		if (entry->netdev != netdev)
+			continue;
+
+		dev = lowpan_dev(entry->netdev);
+
+		list_for_each_entry_rcu(pentry, &dev->peers, list) {
+			int ret;
+
+			local_skb = skb_clone(skb, GFP_ATOMIC);
+
+			BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
+			       netdev->name,
+			       &pentry->chan->dst, pentry->chan->dst_type,
+			       &pentry->peer_addr, pentry->chan);
+			ret = send_pkt(pentry->chan, local_skb, netdev);
+			if (ret < 0)
+				err = ret;
+
+			kfree_skb(local_skb);
+		}
+	}
+
+	rcu_read_unlock();
+
+	return err;
+}
+
+static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev)
+{
+	int err = 0;
+	bdaddr_t addr;
+	u8 addr_type;
+
+	/* We must take a copy of the skb before we modify/replace the ipv6
+	 * header as the header could be used elsewhere
+	 */
+	skb = skb_unshare(skb, GFP_ATOMIC);
+	if (!skb)
+		return NET_XMIT_DROP;
+
+	/* Return values from setup_header()
+	 *  <0 - error, packet is dropped
+	 *   0 - this is a multicast packet
+	 *   1 - this is unicast packet
+	 */
+	err = setup_header(skb, netdev, &addr, &addr_type);
+	if (err < 0) {
+		kfree_skb(skb);
+		return NET_XMIT_DROP;
+	}
+
+	if (err) {
+		if (lowpan_cb(skb)->chan) {
+			BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
+			       netdev->name, &addr, addr_type,
+			       &lowpan_cb(skb)->addr, lowpan_cb(skb)->chan);
+			err = send_pkt(lowpan_cb(skb)->chan, skb, netdev);
+		} else {
+			err = -ENOENT;
+		}
+	} else {
+		/* We need to send the packet to every device behind this
+		 * interface.
+		 */
+		err = send_mcast_pkt(skb, netdev);
+	}
+
+	dev_kfree_skb(skb);
+
+	if (err)
+		BT_DBG("ERROR: xmit failed (%d)", err);
+
+	return err < 0 ? NET_XMIT_DROP : err;
+}
+
+static struct lock_class_key bt_tx_busylock;
+static struct lock_class_key bt_netdev_xmit_lock_key;
+
+static void bt_set_lockdep_class_one(struct net_device *dev,
+				     struct netdev_queue *txq,
+				     void *_unused)
+{
+	lockdep_set_class(&txq->_xmit_lock, &bt_netdev_xmit_lock_key);
+}
+
+static int bt_dev_init(struct net_device *dev)
+{
+	netdev_for_each_tx_queue(dev, bt_set_lockdep_class_one, NULL);
+	dev->qdisc_tx_busylock = &bt_tx_busylock;
+
+	return 0;
+}
+
+static const struct net_device_ops netdev_ops = {
+	.ndo_init		= bt_dev_init,
+	.ndo_start_xmit		= bt_xmit,
+};
+
+static struct header_ops header_ops = {
+	.create	= header_create,
+};
+
+static void netdev_setup(struct net_device *dev)
+{
+	dev->addr_len		= EUI64_ADDR_LEN;
+	dev->type		= ARPHRD_6LOWPAN;
+
+	dev->hard_header_len	= 0;
+	dev->needed_tailroom	= 0;
+	dev->mtu		= IPV6_MIN_MTU;
+	dev->tx_queue_len	= 0;
+	dev->flags		= IFF_RUNNING | IFF_POINTOPOINT |
+				  IFF_MULTICAST;
+	dev->watchdog_timeo	= 0;
+
+	dev->netdev_ops		= &netdev_ops;
+	dev->header_ops		= &header_ops;
+	dev->destructor		= free_netdev;
+}
+
+static struct device_type bt_type = {
+	.name	= "bluetooth",
+};
+
+static void set_addr(u8 *eui, u8 *addr, u8 addr_type)
+{
+	/* addr is the BT address in little-endian format */
+	eui[0] = addr[5];
+	eui[1] = addr[4];
+	eui[2] = addr[3];
+	eui[3] = 0xFF;
+	eui[4] = 0xFE;
+	eui[5] = addr[2];
+	eui[6] = addr[1];
+	eui[7] = addr[0];
+
+	/* Universal/local bit set, BT 6lowpan draft ch. 3.2.1 */
+	if (addr_type == BDADDR_LE_PUBLIC)
+		eui[0] &= ~0x02;
+	else
+		eui[0] |= 0x02;
+
+	BT_DBG("type %d addr %*phC", addr_type, 8, eui);
+}
+
+static void set_dev_addr(struct net_device *netdev, bdaddr_t *addr,
+		         u8 addr_type)
+{
+	netdev->addr_assign_type = NET_ADDR_PERM;
+	set_addr(netdev->dev_addr, addr->b, addr_type);
+}
+
+static void ifup(struct net_device *netdev)
+{
+	int err;
+
+	rtnl_lock();
+	err = dev_open(netdev);
+	if (err < 0)
+		BT_INFO("iface %s cannot be opened (%d)", netdev->name, err);
+	rtnl_unlock();
+}
+
+static void ifdown(struct net_device *netdev)
+{
+	int err;
+
+	rtnl_lock();
+	err = dev_close(netdev);
+	if (err < 0)
+		BT_INFO("iface %s cannot be closed (%d)", netdev->name, err);
+	rtnl_unlock();
+}
+
+static void do_notify_peers(struct work_struct *work)
+{
+	struct lowpan_dev *dev = container_of(work, struct lowpan_dev,
+					      notify_peers.work);
+
+	netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */
+}
+
+static bool is_bt_6lowpan(struct hci_conn *hcon)
+{
+	if (hcon->type != LE_LINK)
+		return false;
+
+	if (!enable_6lowpan)
+		return false;
+
+	return true;
+}
+
+static struct l2cap_chan *chan_create(void)
+{
+	struct l2cap_chan *chan;
+
+	chan = l2cap_chan_create();
+	if (!chan)
+		return NULL;
+
+	l2cap_chan_set_defaults(chan);
+
+	chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
+	chan->mode = L2CAP_MODE_LE_FLOWCTL;
+	chan->omtu = 65535;
+	chan->imtu = chan->omtu;
+
+	return chan;
+}
+
+static struct l2cap_chan *chan_open(struct l2cap_chan *pchan)
+{
+	struct l2cap_chan *chan;
+
+	chan = chan_create();
+	if (!chan)
+		return NULL;
+
+	chan->remote_mps = chan->omtu;
+	chan->mps = chan->omtu;
+
+	chan->state = BT_CONNECTED;
+
+	return chan;
+}
+
+static void set_ip_addr_bits(u8 addr_type, u8 *addr)
+{
+	if (addr_type == BDADDR_LE_PUBLIC)
+		*addr |= 0x02;
+	else
+		*addr &= ~0x02;
+}
+
+static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
+					struct lowpan_dev *dev)
+{
+	struct lowpan_peer *peer;
+
+	peer = kzalloc(sizeof(*peer), GFP_ATOMIC);
+	if (!peer)
+		return NULL;
+
+	peer->chan = chan;
+	memset(&peer->peer_addr, 0, sizeof(struct in6_addr));
+
+	/* RFC 2464 ch. 5 */
+	peer->peer_addr.s6_addr[0] = 0xFE;
+	peer->peer_addr.s6_addr[1] = 0x80;
+	set_addr((u8 *)&peer->peer_addr.s6_addr + 8, chan->dst.b,
+		 chan->dst_type);
+
+	memcpy(&peer->eui64_addr, (u8 *)&peer->peer_addr.s6_addr + 8,
+	       EUI64_ADDR_LEN);
+
+	/* IPv6 address needs to have the U/L bit set properly so toggle
+	 * it back here.
+	 */
+	set_ip_addr_bits(chan->dst_type, (u8 *)&peer->peer_addr.s6_addr + 8);
+
+	spin_lock(&devices_lock);
+	INIT_LIST_HEAD(&peer->list);
+	peer_add(dev, peer);
+	spin_unlock(&devices_lock);
+
+	/* Notifying peers about us needs to be done without locks held */
+	INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers);
+	schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100));
+
+	return peer->chan;
+}
+
+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,
+			      NET_NAME_UNKNOWN, netdev_setup);
+	if (!netdev)
+		return -ENOMEM;
+
+	set_dev_addr(netdev, &chan->src, chan->src_type);
+
+	netdev->netdev_ops = &netdev_ops;
+	SET_NETDEV_DEV(netdev, &chan->conn->hcon->dev);
+	SET_NETDEV_DEVTYPE(netdev, &bt_type);
+
+	err = register_netdev(netdev);
+	if (err < 0) {
+		BT_INFO("register_netdev failed %d", err);
+		free_netdev(netdev);
+		goto out;
+	}
+
+	BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d",
+	       netdev->ifindex, &chan->dst, chan->dst_type,
+	       &chan->src, chan->src_type);
+	set_bit(__LINK_STATE_PRESENT, &netdev->state);
+
+	*dev = netdev_priv(netdev);
+	(*dev)->netdev = netdev;
+	(*dev)->hdev = chan->conn->hcon->hdev;
+	INIT_LIST_HEAD(&(*dev)->peers);
+
+	spin_lock(&devices_lock);
+	INIT_LIST_HEAD(&(*dev)->list);
+	list_add_rcu(&(*dev)->list, &bt_6lowpan_devices);
+	spin_unlock(&devices_lock);
+
+	return 0;
+
+out:
+	return err;
+}
+
+static inline void chan_ready_cb(struct l2cap_chan *chan)
+{
+	struct lowpan_dev *dev;
+
+	dev = lookup_dev(chan->conn);
+
+	BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev);
+
+	if (!dev) {
+		if (setup_netdev(chan, &dev) < 0) {
+			l2cap_chan_del(chan, -ENOENT);
+			return;
+		}
+	}
+
+	if (!try_module_get(THIS_MODULE))
+		return;
+
+	add_peer_chan(chan, dev);
+	ifup(dev->netdev);
+}
+
+static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan)
+{
+	struct l2cap_chan *chan;
+
+	chan = chan_open(pchan);
+	chan->ops = pchan->ops;
+
+	BT_DBG("chan %p pchan %p", chan, pchan);
+
+	return chan;
+}
+
+static void delete_netdev(struct work_struct *work)
+{
+	struct lowpan_dev *entry = container_of(work, struct lowpan_dev,
+						delete_netdev);
+
+	unregister_netdev(entry->netdev);
+
+	/* The entry pointer is deleted in device_event() */
+}
+
+static void chan_close_cb(struct l2cap_chan *chan)
+{
+	struct lowpan_dev *entry;
+	struct lowpan_dev *dev = NULL;
+	struct lowpan_peer *peer;
+	int err = -ENOENT;
+	bool last = false, removed = true;
+
+	BT_DBG("chan %p conn %p", chan, chan->conn);
+
+	if (chan->conn && chan->conn->hcon) {
+		if (!is_bt_6lowpan(chan->conn->hcon))
+			return;
+
+		/* If conn is set, then the netdev is also there and we should
+		 * not remove it.
+		 */
+		removed = false;
+	}
+
+	spin_lock(&devices_lock);
+
+	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
+		dev = lowpan_dev(entry->netdev);
+		peer = __peer_lookup_chan(dev, chan);
+		if (peer) {
+			last = peer_del(dev, peer);
+			err = 0;
+
+			BT_DBG("dev %p removing %speer %p", dev,
+			       last ? "last " : "1 ", peer);
+			BT_DBG("chan %p orig refcnt %d", chan,
+			       atomic_read(&chan->kref.refcount));
+
+			l2cap_chan_put(chan);
+			break;
+		}
+	}
+
+	if (!err && last && dev && !atomic_read(&dev->peer_count)) {
+		spin_unlock(&devices_lock);
+
+		cancel_delayed_work_sync(&dev->notify_peers);
+
+		ifdown(dev->netdev);
+
+		if (!removed) {
+			INIT_WORK(&entry->delete_netdev, delete_netdev);
+			schedule_work(&entry->delete_netdev);
+		}
+	} else {
+		spin_unlock(&devices_lock);
+	}
+
+	return;
+}
+
+static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err)
+{
+	BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn,
+	       state_to_string(state), err);
+}
+
+static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan,
+					 unsigned long hdr_len,
+					 unsigned long len, int nb)
+{
+	/* Note that we must allocate using GFP_ATOMIC here as
+	 * this function is called originally from netdev hard xmit
+	 * function in atomic context.
+	 */
+	return bt_skb_alloc(hdr_len + len, GFP_ATOMIC);
+}
+
+static void chan_suspend_cb(struct l2cap_chan *chan)
+{
+	struct sk_buff *skb = chan->data;
+
+	BT_DBG("chan %p conn %p skb %p", chan, chan->conn, skb);
+
+	if (!skb)
+		return;
+
+	lowpan_cb(skb)->status = -EAGAIN;
+}
+
+static void chan_resume_cb(struct l2cap_chan *chan)
+{
+	struct sk_buff *skb = chan->data;
+
+	BT_DBG("chan %p conn %p skb %p", chan, chan->conn, skb);
+
+	if (!skb)
+		return;
+
+	lowpan_cb(skb)->status = 0;
+}
+
+static long chan_get_sndtimeo_cb(struct l2cap_chan *chan)
+{
+	return L2CAP_CONN_TIMEOUT;
+}
+
+static const struct l2cap_ops bt_6lowpan_chan_ops = {
+	.name			= "L2CAP 6LoWPAN channel",
+	.new_connection		= chan_new_conn_cb,
+	.recv			= chan_recv_cb,
+	.close			= chan_close_cb,
+	.state_change		= chan_state_change_cb,
+	.ready			= chan_ready_cb,
+	.resume			= chan_resume_cb,
+	.suspend		= chan_suspend_cb,
+	.get_sndtimeo		= chan_get_sndtimeo_cb,
+	.alloc_skb		= chan_alloc_skb_cb,
+
+	.teardown		= l2cap_chan_no_teardown,
+	.defer			= l2cap_chan_no_defer,
+	.set_shutdown		= l2cap_chan_no_set_shutdown,
+};
+
+static inline __u8 bdaddr_type(__u8 type)
+{
+	if (type == ADDR_LE_DEV_PUBLIC)
+		return BDADDR_LE_PUBLIC;
+	else
+		return BDADDR_LE_RANDOM;
+}
+
+static struct l2cap_chan *chan_get(void)
+{
+	struct l2cap_chan *pchan;
+
+	pchan = chan_create();
+	if (!pchan)
+		return NULL;
+
+	pchan->ops = &bt_6lowpan_chan_ops;
+
+	return pchan;
+}
+
+static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type)
+{
+	struct l2cap_chan *pchan;
+	int err;
+
+	pchan = chan_get();
+	if (!pchan)
+		return -EINVAL;
+
+	err = l2cap_chan_connect(pchan, cpu_to_le16(L2CAP_PSM_IPSP), 0,
+				 addr, dst_type);
+
+	BT_DBG("chan %p err %d", pchan, err);
+	if (err < 0)
+		l2cap_chan_put(pchan);
+
+	return err;
+}
+
+static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type)
+{
+	struct lowpan_peer *peer;
+
+	BT_DBG("conn %p dst type %d", conn, dst_type);
+
+	peer = lookup_peer(conn);
+	if (!peer)
+		return -ENOENT;
+
+	BT_DBG("peer %p chan %p", peer, peer->chan);
+
+	l2cap_chan_close(peer->chan, ENOENT);
+
+	return 0;
+}
+
+static struct l2cap_chan *bt_6lowpan_listen(void)
+{
+	bdaddr_t *addr = BDADDR_ANY;
+	struct l2cap_chan *pchan;
+	int err;
+
+	if (!enable_6lowpan)
+		return NULL;
+
+	pchan = chan_get();
+	if (!pchan)
+		return NULL;
+
+	pchan->state = BT_LISTEN;
+	pchan->src_type = BDADDR_LE_PUBLIC;
+
+	atomic_set(&pchan->nesting, L2CAP_NESTING_PARENT);
+
+	BT_DBG("chan %p src type %d", pchan, pchan->src_type);
+
+	err = l2cap_add_psm(pchan, addr, cpu_to_le16(L2CAP_PSM_IPSP));
+	if (err) {
+		l2cap_chan_put(pchan);
+		BT_ERR("psm cannot be added err %d", err);
+		return NULL;
+	}
+
+	return pchan;
+}
+
+static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type,
+			  struct l2cap_conn **conn)
+{
+	struct hci_conn *hcon;
+	struct hci_dev *hdev;
+	bdaddr_t *src = BDADDR_ANY;
+	int n;
+
+	n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu",
+		   &addr->b[5], &addr->b[4], &addr->b[3],
+		   &addr->b[2], &addr->b[1], &addr->b[0],
+		   addr_type);
+
+	if (n < 7)
+		return -EINVAL;
+
+	hdev = hci_get_route(addr, src);
+	if (!hdev)
+		return -ENOENT;
+
+	hci_dev_lock(hdev);
+	hcon = hci_conn_hash_lookup_ba(hdev, LE_LINK, addr);
+	hci_dev_unlock(hdev);
+
+	if (!hcon)
+		return -ENOENT;
+
+	*conn = (struct l2cap_conn *)hcon->l2cap_data;
+
+	BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type);
+
+	return 0;
+}
+
+static void disconnect_all_peers(void)
+{
+	struct lowpan_dev *entry;
+	struct lowpan_peer *peer, *tmp_peer, *new_peer;
+	struct list_head peers;
+
+	INIT_LIST_HEAD(&peers);
+
+	/* We make a separate list of peers as the close_cb() will
+	 * modify the device peers list so it is better not to mess
+	 * with the same list at the same time.
+	 */
+
+	rcu_read_lock();
+
+	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
+		list_for_each_entry_rcu(peer, &entry->peers, list) {
+			new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC);
+			if (!new_peer)
+				break;
+
+			new_peer->chan = peer->chan;
+			INIT_LIST_HEAD(&new_peer->list);
+
+			list_add(&new_peer->list, &peers);
+		}
+	}
+
+	rcu_read_unlock();
+
+	spin_lock(&devices_lock);
+	list_for_each_entry_safe(peer, tmp_peer, &peers, list) {
+		l2cap_chan_close(peer->chan, ENOENT);
+
+		list_del_rcu(&peer->list);
+		kfree_rcu(peer, rcu);
+
+		module_put(THIS_MODULE);
+	}
+	spin_unlock(&devices_lock);
+}
+
+struct set_enable {
+	struct work_struct work;
+	bool flag;
+};
+
+static void do_enable_set(struct work_struct *work)
+{
+	struct set_enable *set_enable = container_of(work,
+						     struct set_enable, work);
+
+	if (!set_enable->flag || enable_6lowpan != set_enable->flag)
+		/* Disconnect existing connections if 6lowpan is
+		 * disabled
+		 */
+		disconnect_all_peers();
+
+	enable_6lowpan = set_enable->flag;
+
+	if (listen_chan) {
+		l2cap_chan_close(listen_chan, 0);
+		l2cap_chan_put(listen_chan);
+	}
+
+	listen_chan = bt_6lowpan_listen();
+
+	kfree(set_enable);
+}
+
+static int lowpan_enable_set(void *data, u64 val)
+{
+	struct set_enable *set_enable;
+
+	set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL);
+	if (!set_enable)
+		return -ENOMEM;
+
+	set_enable->flag = !!val;
+	INIT_WORK(&set_enable->work, do_enable_set);
+
+	schedule_work(&set_enable->work);
+
+	return 0;
+}
+
+static int lowpan_enable_get(void *data, u64 *val)
+{
+	*val = enable_6lowpan;
+	return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get,
+			lowpan_enable_set, "%llu\n");
+
+static ssize_t lowpan_control_write(struct file *fp,
+				    const char __user *user_buffer,
+				    size_t count,
+				    loff_t *position)
+{
+	char buf[32];
+	size_t buf_size = min(count, sizeof(buf) - 1);
+	int ret;
+	bdaddr_t addr;
+	u8 addr_type;
+	struct l2cap_conn *conn = NULL;
+
+	if (copy_from_user(buf, user_buffer, buf_size))
+		return -EFAULT;
+
+	buf[buf_size] = '\0';
+
+	if (memcmp(buf, "connect ", 8) == 0) {
+		ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn);
+		if (ret == -EINVAL)
+			return ret;
+
+		if (listen_chan) {
+			l2cap_chan_close(listen_chan, 0);
+			l2cap_chan_put(listen_chan);
+			listen_chan = NULL;
+		}
+
+		if (conn) {
+			struct lowpan_peer *peer;
+
+			if (!is_bt_6lowpan(conn->hcon))
+				return -EINVAL;
+
+			peer = lookup_peer(conn);
+			if (peer) {
+				BT_DBG("6LoWPAN connection already exists");
+				return -EALREADY;
+			}
+
+			BT_DBG("conn %p dst %pMR type %d user %d", conn,
+			       &conn->hcon->dst, conn->hcon->dst_type,
+			       addr_type);
+		}
+
+		ret = bt_6lowpan_connect(&addr, addr_type);
+		if (ret < 0)
+			return ret;
+
+		return count;
+	}
+
+	if (memcmp(buf, "disconnect ", 11) == 0) {
+		ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn);
+		if (ret < 0)
+			return ret;
+
+		ret = bt_6lowpan_disconnect(conn, addr_type);
+		if (ret < 0)
+			return ret;
+
+		return count;
+	}
+
+	return count;
+}
+
+static int lowpan_control_show(struct seq_file *f, void *ptr)
+{
+	struct lowpan_dev *entry;
+	struct lowpan_peer *peer;
+
+	spin_lock(&devices_lock);
+
+	list_for_each_entry(entry, &bt_6lowpan_devices, list) {
+		list_for_each_entry(peer, &entry->peers, list)
+			seq_printf(f, "%pMR (type %u)\n",
+				   &peer->chan->dst, peer->chan->dst_type);
+	}
+
+	spin_unlock(&devices_lock);
+
+	return 0;
+}
+
+static int lowpan_control_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, lowpan_control_show, inode->i_private);
+}
+
+static const struct file_operations lowpan_control_fops = {
+	.open		= lowpan_control_open,
+	.read		= seq_read,
+	.write		= lowpan_control_write,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static void disconnect_devices(void)
+{
+	struct lowpan_dev *entry, *tmp, *new_dev;
+	struct list_head devices;
+
+	INIT_LIST_HEAD(&devices);
+
+	/* We make a separate list of devices because the unregister_netdev()
+	 * will call device_event() which will also want to modify the same
+	 * devices list.
+	 */
+
+	rcu_read_lock();
+
+	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
+		new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC);
+		if (!new_dev)
+			break;
+
+		new_dev->netdev = entry->netdev;
+		INIT_LIST_HEAD(&new_dev->list);
+
+		list_add_rcu(&new_dev->list, &devices);
+	}
+
+	rcu_read_unlock();
+
+	list_for_each_entry_safe(entry, tmp, &devices, list) {
+		ifdown(entry->netdev);
+		BT_DBG("Unregistering netdev %s %p",
+		       entry->netdev->name, entry->netdev);
+		unregister_netdev(entry->netdev);
+		kfree(entry);
+	}
+}
+
+static int device_event(struct notifier_block *unused,
+			unsigned long event, void *ptr)
+{
+	struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
+	struct lowpan_dev *entry;
+
+	if (netdev->type != ARPHRD_6LOWPAN)
+		return NOTIFY_DONE;
+
+	switch (event) {
+	case NETDEV_UNREGISTER:
+		spin_lock(&devices_lock);
+		list_for_each_entry(entry, &bt_6lowpan_devices, list) {
+			if (entry->netdev == netdev) {
+				BT_DBG("Unregistered netdev %s %p",
+				       netdev->name, netdev);
+				list_del(&entry->list);
+				kfree(entry);
+				break;
+			}
+		}
+		spin_unlock(&devices_lock);
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block bt_6lowpan_dev_notifier = {
+	.notifier_call = device_event,
+};
+
+static int __init bt_6lowpan_init(void)
+{
+	lowpan_enable_debugfs = debugfs_create_file("6lowpan_enable", 0644,
+						    bt_debugfs, NULL,
+						    &lowpan_enable_fops);
+	lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644,
+						     bt_debugfs, NULL,
+						     &lowpan_control_fops);
+
+	return register_netdevice_notifier(&bt_6lowpan_dev_notifier);
+}
+
+static void __exit bt_6lowpan_exit(void)
+{
+	debugfs_remove(lowpan_enable_debugfs);
+	debugfs_remove(lowpan_control_debugfs);
+
+	if (listen_chan) {
+		l2cap_chan_close(listen_chan, 0);
+		l2cap_chan_put(listen_chan);
+	}
+
+	disconnect_devices();
+
+	unregister_netdevice_notifier(&bt_6lowpan_dev_notifier);
+}
+
+module_init(bt_6lowpan_init);
+module_exit(bt_6lowpan_exit);
+
+MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>");
+MODULE_DESCRIPTION("Bluetooth 6LoWPAN");
+MODULE_VERSION(VERSION);
+MODULE_LICENSE("GPL");