path: root/net/bluetooth/6lowpan.c

// SPDX-License-Identifier: GPL-2.0-only
/*
   Copyright (c) 2013-2014 Intel Corp.

*/

#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/pkt_sched.h>

#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"

struct skb_cb {
	struct in6_addr addr;
	struct in6_addr gw;
	struct l2cap_chan *chan;
};
#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;
static DEFINE_MUTEX(set_lock);

struct lowpan_peer {
	struct list_head list;
	struct rcu_head rcu;
	struct l2cap_chan *chan;

	/* peer addresses in various formats */
	unsigned char lladdr[ETH_ALEN];
	struct in6_addr peer_addr;
};

struct lowpan_btle_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_btle_dev *
lowpan_btle_dev(const struct net_device *netdev)
{
	return (struct lowpan_btle_dev *)lowpan_dev(netdev)->priv;
}

static inline void peer_add(struct lowpan_btle_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_btle_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_chan(struct lowpan_btle_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_btle_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;
	}