net/bluetooth/hci_conn.c

/*
   BlueZ - Bluetooth protocol stack for Linux
   Copyright (c) 2000-2001, 2010-2012 Code Aurora Forum.  All rights reserved.

   Written 2000,2001 by Maxim Krasnyansky <maxk@qualcomm.com>

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License version 2 as
   published by the Free Software Foundation;

   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
   OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
   IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
   CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
   ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

   ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
   COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
   SOFTWARE IS DISCLAIMED.
*/

/* Bluetooth HCI connection handling. */

#include <linux/module.h>

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/fcntl.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/interrupt.h>
#include <linux/notifier.h>
#include <net/sock.h>

#include <asm/system.h>
#include <linux/uaccess.h>
#include <asm/unaligned.h>

#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
#include <net/bluetooth/l2cap.h>

struct hci_conn *hci_le_connect(struct hci_dev *hdev, __u16 pkt_type,
				bdaddr_t *dst, __u8 sec_level, __u8 auth_type,
				struct bt_le_params *le_params)
{
	struct hci_conn *le;
	struct hci_cp_le_create_conn cp;
	struct adv_entry *entry;
	struct link_key *key;

	BT_DBG("%p", hdev);

	le = hci_conn_hash_lookup_ba(hdev, LE_LINK, dst);
	if (le) {
		hci_conn_hold(le);
		return le;
	}

	key = hci_find_link_key_type(hdev, dst, KEY_TYPE_LTK);
	if (!key) {
		entry = hci_find_adv_entry(hdev, dst);
		if (entry)
			le = hci_le_conn_add(hdev, dst,
					entry->bdaddr_type);
		else
			le = hci_le_conn_add(hdev, dst, 0);
	} else {
		le = hci_le_conn_add(hdev, dst, key->addr_type);
	}

	if (!le)
		return ERR_PTR(-ENOMEM);

	hci_conn_hold(le);

	le->state = BT_CONNECT;
	le->out = 1;
	le->link_mode |= HCI_LM_MASTER;
	le->sec_level = BT_SECURITY_LOW;
	le->type = LE_LINK;

	memset(&cp, 0, sizeof(cp));
	if (l2cap_sock_le_params_valid(le_params)) {
		cp.supervision_timeout =
				cpu_to_le16(le_params->supervision_timeout);
		cp.scan_interval = cpu_to_le16(le_params->scan_interval);
		cp.scan_window = cpu_to_le16(le_params->scan_window);
		cp.conn_interval_min = cpu_to_le16(le_params->interval_min);
		cp.conn_interval_max = cpu_to_le16(le_params->interval_max);
		cp.conn_latency = cpu_to_le16(le_params->latency);
		cp.min_ce_len = cpu_to_le16(le_params->min_ce_len);
		cp.max_ce_len = cpu_to_le16(le_params->max_ce_len);
		le->conn_timeout = le_params->conn_timeout;
	} else {
		cp.supervision_timeout = cpu_to_le16(BT_LE_SUP_TO_DEFAULT);
		cp.scan_interval = cpu_to_le16(BT_LE_SCAN_INTERVAL_DEF);
		cp.scan_window = cpu_to_le16(BT_LE_SCAN_WINDOW_DEF);
		cp.conn_interval_min = cpu_to_le16(BT_LE_CONN_INTERVAL_MIN_DEF);
		cp.conn_interval_max = cpu_to_le16(BT_LE_CONN_INTERVAL_MAX_DEF);
		cp.conn_latency = cpu_to_le16(BT_LE_LATENCY_DEF);
		le->conn_timeout = 5;
	}
	bacpy(&cp.peer_addr, &le->dst);
	cp.peer_addr_type = le->dst_type;

	hci_send_cmd(hdev, HCI_OP_LE_CREATE_CONN, sizeof(cp), &cp);

	return le;
}
EXPORT_SYMBOL(hci_le_connect);

static void hci_le_connect_cancel(struct hci_conn *conn)
{
	hci_send_cmd(conn->hdev, HCI_OP_LE_CREATE_CONN_CANCEL, 0, NULL);
}

void hci_acl_connect(struct hci_conn *conn)
{
	struct hci_dev *hdev = conn->hdev;
	struct inquiry_entry *ie;
	struct hci_cp_create_conn cp;

	BT_DBG("%p", conn);

	conn->state = BT_CONNECT;
	conn->out = 1;

	conn->link_mode = HCI_LM_MASTER;

	conn->attempt++;

	conn->link_policy = hdev->link_policy;

	memset(&cp, 0, sizeof(cp));
	bacpy(&cp.bdaddr, &conn->dst);
	cp.pscan_rep_mode = 0x02;

	ie = hci_inquiry_cache_lookup(hdev, &conn->dst);
	if (ie) {
		if (inquiry_entry_age(ie) <= INQUIRY_ENTRY_AGE_MAX) {
			cp.pscan_rep_mode = ie->data.pscan_rep_mode;
			cp.pscan_mode     = ie->data.pscan_mode;
			cp.clock_offset   = ie->data.clock_offset |
							cpu_to_le16(0x8000);
		}

		memcpy(conn->dev_class, ie->data.dev_class, 3);
		conn->ssp_mode = ie->data.ssp_mode;
	}

	cp.pkt_type = cpu_to_le16(conn->pkt_type);
	if (lmp_rswitch_capable(hdev) && !(hdev->link_mode & HCI_LM_MASTER))
		cp.role_switch = 0x01;
	else
		cp.role_switch = 0x00;

	hci_send_cmd(hdev, HCI_OP_CREATE_CONN, sizeof(cp), &cp);
}

static void hci_acl_connect_cancel(struct hci_conn *conn)
{
	struct hci_cp_create_conn_cancel cp;

	BT_DBG("%p", conn);

	if (conn->hdev->hci_ver < 2)
		return;

	bacpy(&cp.bdaddr, &conn->dst);
	hci_send_cmd(conn->hdev, HCI_OP_CREATE_CONN_CANCEL, sizeof(cp), &cp);
}

void hci_acl_disconn(struct hci_conn *conn, __u8 reason)
{
	BT_DBG("%p", conn);

	conn->state = BT_DISCONN;

	if (conn->hdev->dev_type == HCI_BREDR) {
		struct hci_cp_disconnect cp;
		cp.handle = cpu_to_le16(conn->handle);
		cp.reason = reason;
		hci_send_cmd(conn->hdev, HCI_OP_DISCONNECT, sizeof(cp), &cp);
	} else {
		struct hci_cp_disconn_phys_link cp;
		cp.phy_handle = (u8) conn->handle;
		cp.reason = reason;
		hci_send_cmd(conn->hdev, HCI_OP_DISCONN_PHYS_LINK,
				sizeof(cp), &cp);
	}
}

void hci_add_sco(struct hci_conn *conn, __u16 handle)
{
	struct hci_dev *hdev = conn->hdev;
	struct hci_cp_add_sco cp;

	BT_DBG("%p", conn);

	conn->state = BT_CONNECT;
	conn->out = 1;

	conn->attempt++;

	cp.handle   = cpu_to_le16(handle);
	cp.pkt_type = cpu_to_le16(conn->pkt_type);

	hci_send_cmd(hdev, HCI_OP_ADD_SCO, sizeof(cp), &cp);
}

void hci_setup_sync(struct hci_conn *conn, __u16 handle)
{
	struct hci_dev *hdev = conn->hdev;
	struct hci_cp_setup_sync_conn cp;

	BT_DBG("%p", conn);

	conn->state = BT_CONNECT;
	conn->out = 1;

	conn->attempt++;

	cp.handle   = cpu_to_le16(handle);

	cp.tx_bandwidth   = cpu_to_le32(0x00001f40);
	cp.rx_bandwidth   = cpu_to_le32(0x00001f40);
	if (conn->hdev->is_wbs) {
		/* Transparent Data */
		uint16_t voice_setting = hdev->voice_setting | ACF_TRANS;
		cp.max_latency    = cpu_to_le16(0x000D);
		cp.pkt_type = cpu_to_le16(ESCO_WBS);
		cp.voice_setting  = cpu_to_le16(voice_setting);
		/* Retransmission Effort */
		cp.retrans_effort = RE_LINK_QUALITY;
	} else {
		cp.max_latency    = cpu_to_le16(0x000A);
		cp.pkt_type = cpu_to_le16(conn->pkt_type);
		cp.voice_setting  = cpu_to_le16(hdev->voice_setting);
		cp.retrans_effort = RE_POWER_CONSUMP;
	}

	hci_send_cmd(hdev, HCI_OP_SETUP_SYNC_CONN, sizeof(cp), &cp);
}

void hci_le_conn_update(struct hci_conn *conn, u16 min, u16 max,
					u16 latency, u16 to_multiplier)
{
	struct hci_cp_le_conn_update cp;
	struct hci_dev *hdev = conn->hdev;

	memset(&cp, 0, sizeof(cp));

	cp.handle		= cpu_to_le16(conn->handle);
	cp.conn_interval_min	= cpu_to_le16(min);
	cp.conn_interval_max	= cpu_to_le16(max);
	cp.conn_latency		= cpu_to_le16(latency);
	cp.supervision_timeout	= cpu_to_le16(to_multiplier);
	cp.min_ce_len		= cpu_to_le16(0x0001);
	cp.max_ce_len		= cpu_to_le16(0x0001);

	hci_send_cmd(hdev, HCI_OP_LE_CONN_UPDATE, sizeof(cp), &cp);
}
EXPORT_SYMBOL(hci_le_conn_update);

void hci_read_rssi(struct hci_conn *conn)
{
	struct hci_cp_read_rssi cp;
	struct hci_dev *hdev = conn->hdev;

	memset(&cp, 0, sizeof(cp));
	cp.handle   = cpu_to_le16(conn->handle);

	hci_send_cmd(hdev, HCI_OP_READ_RSSI, sizeof(cp), &cp);
}
EXPORT_SYMBOL(hci_read_rssi);

void hci_le_start_enc(struct hci_conn *conn, __le16 ediv, __u8 rand[8],
							__u8 ltk[16])
{
	struct hci_dev *hdev = conn->hdev;
	struct hci_cp_le_start_enc cp;

	BT_DBG("%p", conn);

	memset(&cp, 0, sizeof(cp));

	cp.handle = cpu_to_le16(conn->handle);
	memcpy(cp.ltk, ltk, sizeof(cp.ltk));
	cp.ediv = ediv;
	memcpy(cp.rand, rand, sizeof(cp.rand));

	hci_send_cmd(hdev, HCI_OP_LE_START_ENC, sizeof(cp), &cp);
}
EXPORT_SYMBOL(hci_le_start_enc);

void hci_le_ltk_reply(struct hci_conn *conn, u8 ltk[16])
{
	struct hci_dev *hdev = conn->hdev;
	struct hci_cp_le_ltk_reply cp;

	BT_DBG("%p", conn);

	memset(&cp, 0, sizeof(cp));

	cp.handle = cpu_to_le16(conn->handle);
	memcpy(cp.ltk, ltk, sizeof(ltk));

	hci_send_cmd(hdev, HCI_OP_LE_LTK_REPLY, sizeof(cp), &cp);
}
EXPORT_SYMBOL(hci_le_ltk_reply);

void hci_le_ltk_neg_reply(struct hci_conn *conn)
{
	struct hci_dev *hdev = conn->hdev;
	struct hci_cp_le_ltk_neg_reply cp;

	BT_DBG("%p", conn);

	memset(&cp, 0, sizeof(cp));

	cp.handle = cpu_to_le16(conn->handle);

	hci_send_cmd(hdev, HCI_OP_LE_LTK_NEG_REPLY, sizeof(cp), &cp);
}

/* Device _must_ be locked */
void hci_sco_setup(struct hci_conn *conn, __u8 status)
{
	struct hci_conn *sco = conn->link;

	BT_DBG("%p", conn);

	if (!sco)
		return;

	if (!status) {
		if (lmp_esco_capable(conn->hdev))
			hci_setup_sync(sco, conn->handle);
		else
			hci_add_sco(sco, conn->handle);
	} else {
		hci_proto_connect_cfm(sco, status);
		hci_conn_del(sco);
	}
}

static void hci_conn_timeout(unsigned long arg)
{
	struct hci_conn *conn = (void *) arg;
	struct hci_dev *hdev = conn->hdev;
	__u8 reason;

	BT_DBG("conn %p state %d", conn, conn->state);

	hci_dev_lock(hdev);

	switch (conn->state) {
	case BT_CONNECT:
	case BT_CONNECT2:
		if (conn->out) {
			if (conn->type == ACL_LINK)
				hci_acl_connect_cancel(conn);
			else if (conn->type == LE_LINK)
				hci_le_connect_cancel(conn);
		}
		break;
	case BT_CONFIG:
	case BT_CONNECTED:
		if (!atomic_read(&conn->refcnt)) {
			reason = hci_proto_disconn_ind(conn);
			hci_acl_disconn(conn, reason);
		}
		break;
	default:
		if (!atomic_read(&conn->refcnt))
			conn->state = BT_CLOSED;
		break;
	}

	hci_dev_unlock(hdev);
}

static void hci_conn_idle(unsigned long arg)
{
	struct hci_conn *conn = (void *) arg;

	BT_DBG("conn %p mode %d", conn, conn->mode);

	hci_conn_enter_sniff_mode(conn);
}

static void hci_conn_rssi_update(struct work_struct *work)
{
	struct delayed_work *delayed =
		container_of(work, struct delayed_work, work);
	struct hci_conn *conn =
		container_of(delayed, struct hci_conn, rssi_update_work);

	BT_DBG("conn %p mode %d", conn, conn->mode);

	hci_read_rssi(conn);
}

static void encryption_disabled_timeout(unsigned long userdata)
{
	struct hci_conn *conn = (struct hci_conn *)userdata;
	BT_INFO("conn %p Grace Prd Exp ", conn);

	hci_encrypt_cfm(conn, 0, 0);

	if (test_bit(HCI_CONN_ENCRYPT_PEND, &conn->pend)) {
		struct hci_cp_set_conn_encrypt cp;
		BT_INFO("HCI_CONN_ENCRYPT_PEND is set");
		cp.handle  = cpu_to_le16(conn->handle);
		cp.encrypt = 1;
		hci_send_cmd(conn->hdev, HCI_OP_SET_CONN_ENCRYPT,
						sizeof(cp), &cp);
	}

}

struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type,
					__u16 pkt_type, bdaddr_t *dst)
{
	struct hci_conn *conn;

	BT_DBG("%s dst %s", hdev->name, batostr(dst));

	conn = kzalloc(sizeof(struct hci_conn), GFP_ATOMIC);
	if (!conn)
		return NULL;

	bacpy(&conn->dst, dst);
	conn->hdev  = hdev;
	conn->type  = type;
	conn->mode  = HCI_CM_ACTIVE;
	conn->state = BT_OPEN;
	conn->auth_type = HCI_AT_GENERAL_BONDING;
	conn->io_capability = hdev->io_capability;
	conn->remote_auth = 0xff;

	conn->power_save = 1;
	conn->disc_timeout = HCI_DISCONN_TIMEOUT;

	switch (type) {
	case ACL_LINK:
		conn->pkt_type = hdev->pkt_type & ACL_PTYPE_MASK;
		conn->link_policy = hdev->link_policy;
		break;
	case SCO_LINK:
		if (!pkt_type)
			pkt_type = SCO_ESCO_MASK;
	case ESCO_LINK:
		if (!pkt_type)
			pkt_type = ALL_ESCO_MASK;
		if (lmp_esco_capable(hdev)) {
			/* HCI Setup Synchronous Connection Command uses
			   reverse logic on the EDR_ESCO_MASK bits */
			conn->pkt_type = (pkt_type ^ EDR_ESCO_MASK) &
					hdev->esco_type;
		} else {
			/* Legacy HCI Add Sco Connection Command uses a
			   shifted bitmask */
			conn->pkt_type = (pkt_type << 5) & hdev->pkt_type &
					SCO_PTYPE_MASK;
		}
		break;
	}

	skb_queue_head_init(&conn->data_q);

	setup_timer(&conn->disc_timer, hci_conn_timeout, (unsigned long)conn);
	setup_timer(&conn->idle_timer, hci_conn_idle, (unsigned long)conn);
	INIT_DELAYED_WORK(&conn->rssi_update_work, hci_conn_rssi_update);
	setup_timer(&conn->encrypt_pause_timer, encryption_disabled_timeout,
			(unsigned long)conn);

	atomic_set(&conn->refcnt, 0);

	hci_dev_hold(hdev);

	tasklet_disable(&hdev->tx_task);

	hci_conn_hash_add(hdev, conn);
	if (hdev->notify)
		hdev->notify(hdev, HCI_NOTIFY_CONN_ADD);

	atomic_set(&conn->devref, 0);

	hci_conn_init_sysfs(conn);

	tasklet_enable(&hdev->tx_task);

	return conn;
}

struct hci_conn *hci_le_conn_add(struct hci_dev *hdev, bdaddr_t *dst,
							__u8 addr_type)
{
	struct hci_conn *conn = hci_conn_add(hdev, LE_LINK, 0, dst);
	if (!conn)
		return NULL;

	conn->dst_type = addr_type;

	return conn;
}

int hci_conn_del(struct hci_conn *conn)
{
	struct hci_dev *hdev = conn->hdev;

	BT_DBG("%s conn %p handle %d", hdev->name, conn, conn->handle);

	/* Make sure no timers are running */
	del_timer(&conn->idle_timer);
	del_timer(&conn->disc_timer);
	del_timer(&conn->smp_timer);
	__cancel_delayed_work(&conn->rssi_update_work);
	del_timer(&conn->encrypt_pause_timer);

	if (conn->type == ACL_LINK) {
		struct hci_conn *sco = conn->link;
		if (sco)
			sco->link = NULL;

		/* Unacked frames */
		hdev->acl_cnt += conn->sent;
	} else if (conn->type == LE_LINK) {
		if (hdev->le_pkts)
			hdev->le_cnt += conn->sent;
		else
			hdev->acl_cnt += conn->sent;
	} else {
		struct hci_conn *acl = conn->link;
		if (acl) {
			acl->link = NULL;
			hci_conn_put(acl);
		}
	}

	tasklet_disable(&hdev->tx_task);

	hci_conn_hash_del(hdev, conn);
	if (hdev->notify)
		hdev->notify(hdev, HCI_NOTIFY_CONN_DEL);

	tasklet_schedule(&hdev->tx_task);

	tasklet_enable(&hdev->tx_task);

	skb_queue_purge(&conn->data_q);

	hci_conn_put_device(conn);

	hci_dev_put(hdev);

	return 0;
}

struct hci_chan *hci_chan_add(struct hci_dev *hdev)
{
	struct hci_chan *chan;

	BT_DBG("%s", hdev->name);

	chan = kzalloc(sizeof(struct hci_chan), GFP_ATOMIC);
	if (!chan)
		return NULL;

	atomic_set(&chan->refcnt, 0);

	hci_dev_hold(hdev);

	chan->hdev = hdev;

	list_add(&chan->list, &hdev->chan_list.list);

	return chan;
}
EXPORT_SYMBOL(hci_chan_add);

int hci_chan_del(struct hci_chan *chan)
{
	BT_DBG("%s chan %p", chan->hdev->name, chan);

	list_del(&chan->list);

	hci_conn_put(chan->conn);
	hci_dev_put(chan->hdev);

	kfree(chan);

	return 0;
}

int hci_chan_put(struct hci_chan *chan)
{
	struct hci_cp_disconn_logical_link cp;
	struct hci_conn *hcon;
	u16 ll_handle;

	BT_DBG("chan %p refcnt %d", chan, atomic_read(&chan->refcnt));
	if (!atomic_dec_and_test(&chan->refcnt))
		return 0;

	hcon = chan->conn;
	ll_handle = chan->ll_handle;

	hci_chan_del(chan);

	BT_DBG("chan->conn->state %d", hcon->state);
	if (hcon->state == BT_CONNECTED) {
		cp.log_handle = cpu_to_le16(ll_handle);
		hci_send_cmd(hcon->hdev, HCI_OP_DISCONN_LOGICAL_LINK,
				sizeof(cp), &cp);
	}

	return 1;
}
EXPORT_SYMBOL(hci_chan_put);

struct hci_dev *hci_get_route(bdaddr_t *dst, bdaddr_t *src)
{
	int use_src = bacmp(src, BDADDR_ANY);
	struct hci_dev *hdev = NULL;
	struct list_head *p;

	BT_DBG("%s -> %s", batostr(src), batostr(dst));

	read_lock_bh(&hci_dev_list_lock);

	list_for_each(p, &hci_dev_list) {
		struct hci_dev *d = list_entry(p, struct hci_dev, list);

		if (d->dev_type != HCI_BREDR)
			continue;
		if (!test_bit(HCI_UP, &d->flags) || test_bit(HCI_RAW, &d->flags))
			continue;

		/* Simple routing:
		 *   No source address - find interface with bdaddr != dst
		 *   Source address    - find interface with bdaddr == src
		 */

		if (use_src) {
			if (!bacmp(&d->bdaddr, src)) {
				hdev = d; break;
			}
		} else {
			if (bacmp(&d->bdaddr, dst)) {
				hdev = d; break;
			}
		}
	}

	if (hdev)
		hdev = hci_dev_hold(hdev);

	read_unlock_bh(&hci_dev_list_lock);
	return hdev;
}
EXPORT_SYMBOL(hci_get_route);

struct hci_dev *hci_dev_get_type(u8 amp_type)
{
	struct hci_dev *hdev = NULL;
	struct hci_dev *d;

	BT_DBG("amp_type %d", amp_type);

	read_lock_bh(&hci_dev_list_lock);

	list_for_each_entry(d, &hci_dev_list, list) {
		if ((d->amp_type == amp_type) && test_bit(HCI_UP, &d->flags)) {
			hdev = d;
			break;
		}
	}

	if (hdev)
		hdev = hci_dev_hold(hdev);

	read_unlock_bh(&hci_dev_list_lock);
	return hdev;
}
EXPORT_SYMBOL(hci_dev_get_type);

struct hci_dev *hci_dev_get_amp(bdaddr_t *dst)
{
	struct hci_dev *d;
	struct hci_dev *hdev = NULL;

	BT_DBG("%s dst %s", hdev->name, batostr(dst));

	read_lock_bh(&hci_dev_list_lock);

	list_for_each_entry(d, &hci_dev_list, list) {
		struct hci_conn *conn;
		if (d->dev_type == HCI_BREDR)
			continue;
		conn = hci_conn_hash_lookup_ba(d, ACL_LINK, dst);
		if (conn) {
			hdev = d;
			break;
		}
	}

	if (hdev)
		hdev = hci_dev_hold(hdev);

	read_unlock_bh(&hci_dev_list_lock);
	return hdev;
}
EXPORT_SYMBOL(hci_dev_get_amp);

/* Create SCO, ACL or LE connection.
 * Device _must_ be locked */
struct hci_conn *hci_connect(struct hci_dev *hdev, int type,
					__u16 pkt_type, bdaddr_t *dst,
					__u8 sec_level, __u8 auth_type)
{
	struct hci_conn *acl;
	struct hci_conn *sco;

	BT_DBG("%s dst %s", hdev->name, batostr(dst));

	if (type == LE_LINK)
		return hci_le_connect(hdev, pkt_type, dst, sec_level,
							auth_type, NULL);

	acl = hci_conn_hash_lookup_ba(hdev, ACL_LINK, dst);
	if (!acl) {
		acl = hci_conn_add(hdev, ACL_LINK, 0, dst);
		if (!acl)
			return NULL;
	}

	hci_conn_hold(acl);

	if (acl->state == BT_OPEN || acl->state == BT_CLOSED) {
		acl->sec_level = BT_SECURITY_LOW;
		acl->pending_sec_level = sec_level;
		acl->auth_type = auth_type;
		hci_acl_connect(acl);
	}

	if (type == ACL_LINK)
		return acl;

	sco = hci_conn_hash_lookup_ba(hdev, type, dst);
	if (!sco) {
		sco = hci_conn_add(hdev, type, pkt_type, dst);
		if (!sco) {
			hci_conn_put(acl);
			return NULL;
		}
	}

	acl->link = sco;
	sco->link = acl;

	hci_conn_hold(sco);

	if (acl->state == BT_CONNECTED &&
			(sco->state == BT_OPEN || sco->state == BT_CLOSED)) {
		acl->power_save = 1;
		hci_conn_enter_active_mode(acl, 1);

		if (test_bit(HCI_CONN_MODE_CHANGE_PEND, &acl->pend)) {
			/* defer SCO setup until mode change completed */
			set_bit(HCI_CONN_SCO_SETUP_PEND, &acl->pend);
			return sco;
		}

		hci_sco_setup(acl, 0x00);
	}

	return sco;
}
EXPORT_SYMBOL(hci_connect);

void hci_disconnect(struct hci_conn *conn, __u8 reason)
{
	BT_DBG("conn %p", conn);

	hci_proto_disconn_cfm(conn, reason, 0);
}
EXPORT_SYMBOL(hci_disconnect);

void hci_disconnect_amp(struct hci_conn *conn, __u8 reason)
{
	struct hci_dev *hdev = NULL;

	BT_DBG("conn %p", conn);

	read_lock_bh(&hci_dev_list_lock);

	list_for_each_entry(hdev, &hci_dev_list, list) {
		struct hci_conn *c;
		if (hdev == conn->hdev)
			continue;
		if (hdev->amp_type == HCI_BREDR)
			continue;
		c = hci_conn_hash_lookup_ba(hdev, ACL_LINK, &conn->dst);
		if (c)
			hci_disconnect(c, reason);
	}

	read_unlock_bh(&hci_dev_list_lock);
}

/* Check link security requirement */
int hci_conn_check_link_mode(struct hci_conn *conn)
{
	BT_DBG("conn %p", conn);

	if (conn->ssp_mode > 0 && conn->hdev->ssp_mode > 0 &&
					!(conn->link_mode & HCI_LM_ENCRYPT))
		return 0;

	return 1;
}
EXPORT_SYMBOL(hci_conn_check_link_mode);

/* Authenticate remote device */
static int hci_conn_auth(struct hci_conn *conn, __u8 sec_level, __u8 auth_type)
{
	BT_DBG("conn %p", conn);

	if (conn->pending_sec_level > sec_level)
		sec_level = conn->pending_sec_level;

	if (sec_level > conn->sec_level)
		conn->pending_sec_level = sec_level;
	else if (conn->link_mode & HCI_LM_AUTH)
		return 1;

	/* Make sure we preserve an existing MITM requirement*/
	auth_type |= (conn->auth_type & 0x01);
	conn->auth_type = auth_type;
	conn->auth_initiator = 1;

	if (!test_and_set_bit(HCI_CONN_AUTH_PEND, &conn->pend)) {
		struct hci_cp_auth_requested cp;

		/* encrypt must be pending if auth is also pending */
		set_bit(HCI_CONN_ENCRYPT_PEND, &conn->pend);

		cp.handle = cpu_to_le16(conn->handle);
		hci_send_cmd(conn->hdev, HCI_OP_AUTH_REQUESTED,
							sizeof(cp), &cp);
	}

	return 0;
}

/* Enable security */
int hci_conn_security(struct hci_conn *conn, __u8 sec_level, __u8 auth_type)
{
	BT_DBG("conn %p %d %d", conn, sec_level, auth_type);

	if (sec_level == BT_SECURITY_SDP)
		return 1;

	if (sec_level == BT_SECURITY_LOW &&
				(!conn->ssp_mode || !conn->hdev->ssp_mode))
		return 1;

	if (conn->type == LE_LINK) {
		if (conn->pending_sec_level > sec_level)
			sec_level = conn->pending_sec_level;

		if (sec_level > conn->sec_level)
			conn->pending_sec_level = sec_level;
		hci_proto_connect_cfm(conn, 0);
		return 0;
	} else if (conn->link_mode & HCI_LM_ENCRYPT) {
		return hci_conn_auth(conn, sec_level, auth_type);
	} else if (test_bit(HCI_CONN_ENCRYPT_PEND, &conn->pend)) {
		return 0;
	}

	if (hci_conn_auth(conn, sec_level, auth_type)) {
		struct hci_cp_set_conn_encrypt cp;
		if (timer_pending(&conn->encrypt_pause_timer)) {
			BT_INFO("encrypt_pause_timer is pending");
			return 0;
		}
		cp.handle  = cpu_to_le16(conn->handle);
		cp.encrypt = 1;
		hci_send_cmd(conn->hdev, HCI_OP_SET_CONN_ENCRYPT,
							sizeof(cp), &cp);
	}

	return 0;
}
EXPORT_SYMBOL(hci_conn_security);

/* Change link key */
int hci_conn_change_link_key(struct hci_conn *conn)
{
	BT_DBG("conn %p", conn);

	if (!test_and_set_bit(HCI_CONN_AUTH_PEND, &conn->pend)) {
		struct hci_cp_change_conn_link_key cp;
		cp.handle = cpu_to_le16(conn->handle);
		hci_send_cmd(conn->hdev, HCI_OP_CHANGE_CONN_LINK_KEY,
							sizeof(cp), &cp);
	}

	return 0;
}
EXPORT_SYMBOL(hci_conn_change_link_key);

/* Switch role */
int hci_conn_switch_role(struct hci_conn *conn, __u8 role)
{
	BT_DBG("conn %p", conn);

	if (!role && conn->link_mode & HCI_LM_MASTER)
		return 1;

	if (!test_and_set_bit(HCI_CONN_RSWITCH_PEND, &conn->pend)) {
		struct hci_cp_switch_role cp;
		bacpy(&cp.bdaddr, &conn->dst);
		cp.role = role;
		hci_send_cmd(conn->hdev, HCI_OP_SWITCH_ROLE, sizeof(cp), &cp);
	}

	return 0;
}
EXPORT_SYMBOL(hci_conn_switch_role);

/* Enter active mode */
void hci_conn_enter_active_mode(struct hci_conn *conn, __u8 force_active)
{
	struct hci_dev *hdev = conn->hdev;

	BT_DBG("conn %p mode %d", conn, conn->mode);

	if (test_bit(HCI_RAW, &hdev->flags))
		return;

	if (conn->mode != HCI_CM_SNIFF)
		goto timer;

	if (!conn->power_save && !force_active)
		goto timer;

	if (!test_and_set_bit(HCI_CONN_MODE_CHANGE_PEND, &conn->pend)) {
		struct hci_cp_exit_sniff_mode cp;
		cp.handle = cpu_to_le16(conn->handle);
		hci_send_cmd(hdev, HCI_OP_EXIT_SNIFF_MODE, sizeof(cp), &cp);
	}

timer:
	if (hdev->idle_timeout > 0)
		mod_timer(&conn->idle_timer,
			jiffies + msecs_to_jiffies(hdev->idle_timeout));
}

static inline void hci_conn_stop_rssi_timer(struct hci_conn *conn)
{
	BT_DBG("conn %p", conn);
	cancel_delayed_work(&conn->rssi_update_work);
}

static inline void hci_conn_start_rssi_timer(struct hci_conn *conn,
	u16 interval)
{
	struct hci_dev *hdev = conn->hdev;
	BT_DBG("conn %p, pending %d", conn,
			delayed_work_pending(&conn->rssi_update_work));
	if (!delayed_work_pending(&conn->rssi_update_work)) {
		queue_delayed_work(hdev->workqueue, &conn->rssi_update_work,
				msecs_to_jiffies(interval));
	}
}

void hci_conn_set_rssi_reporter(struct hci_conn *conn,
	s8 rssi_threshold, u16 interval, u8 updateOnThreshExceed)
{
	if (conn) {
		conn->rssi_threshold = rssi_threshold;
		conn->rssi_update_interval = interval;
		conn->rssi_update_thresh_exceed = updateOnThreshExceed;
		hci_conn_start_rssi_timer(conn, interval);
	}
}

void hci_conn_unset_rssi_reporter(struct hci_conn *conn)
{
	if (conn) {
		BT_DBG("Deleting the rssi_update_timer");
		hci_conn_stop_rssi_timer(conn);
	}
}

/* Enter sniff mode */
void hci_conn_enter_sniff_mode(struct hci_conn *conn)
{
	struct hci_dev *hdev = conn->hdev;

	BT_DBG("conn %p mode %d", conn, conn->mode);

	if (test_bit(HCI_RAW, &hdev->flags))
		return;

	if (!lmp_sniff_capable(hdev) || !lmp_sniff_capable(conn))
		return;

	if (conn->mode != HCI_CM_ACTIVE ||
		!(conn->link_policy & HCI_LP_SNIFF) ||
		(hci_find_link_key(hdev, &conn->dst) == NULL))
		return;

	if (lmp_sniffsubr_capable(hdev) && lmp_sniffsubr_capable(conn)) {
		struct hci_cp_sniff_subrate cp;
		cp.handle             = cpu_to_le16(conn->handle);
		cp.max_latency        = cpu_to_le16(0);
		cp.min_remote_timeout = cpu_to_le16(0);
		cp.min_local_timeout  = cpu_to_le16(0);
		hci_send_cmd(hdev, HCI_OP_SNIFF_SUBRATE, sizeof(cp), &cp);
	}

	if (!test_and_set_bit(HCI_CONN_MODE_CHANGE_PEND, &conn->pend)) {
		struct hci_cp_sniff_mode cp;
		cp.handle       = cpu_to_le16(conn->handle);
		cp.max_interval = cpu_to_le16(hdev->sniff_max_interval);
		cp.min_interval = cpu_to_le16(hdev->sniff_min_interval);
		cp.attempt      = cpu_to_le16(4);
		cp.timeout      = cpu_to_le16(1);
		hci_send_cmd(hdev, HCI_OP_SNIFF_MODE, sizeof(cp), &cp);
	}
}

struct hci_chan *hci_chan_create(struct hci_chan *chan,
			struct hci_ext_fs *tx_fs, struct hci_ext_fs *rx_fs)
{
	struct hci_cp_create_logical_link cp;

	chan->state = BT_CONNECT;
	chan->tx_fs = *tx_fs;
	chan->rx_fs = *rx_fs;
	cp.phy_handle = chan->conn->handle;
	cp.tx_fs.id = chan->tx_fs.id;
	cp.tx_fs.type = chan->tx_fs.type;
	cp.tx_fs.max_sdu = cpu_to_le16(chan->tx_fs.max_sdu);
	cp.tx_fs.sdu_arr_time = cpu_to_le32(chan->tx_fs.sdu_arr_time);
	cp.tx_fs.acc_latency = cpu_to_le32(chan->tx_fs.acc_latency);
	cp.tx_fs.flush_to = cpu_to_le32(chan->tx_fs.flush_to);
	cp.rx_fs.id = chan->rx_fs.id;
	cp.rx_fs.type = chan->rx_fs.type;
	cp.rx_fs.max_sdu = cpu_to_le16(chan->rx_fs.max_sdu);
	cp.rx_fs.sdu_arr_time = cpu_to_le32(chan->rx_fs.sdu_arr_time);
	cp.rx_fs.acc_latency = cpu_to_le32(chan->rx_fs.acc_latency);
	cp.rx_fs.flush_to = cpu_to_le32(chan->rx_fs.flush_to);
	hci_conn_hold(chan->conn);
	if (chan->conn->out)
		hci_send_cmd(chan->conn->hdev, HCI_OP_CREATE_LOGICAL_LINK,
							sizeof(cp), &cp);
	else
		hci_send_cmd(chan->conn->hdev, HCI_OP_ACCEPT_LOGICAL_LINK,
							sizeof(cp), &cp);
	return chan;
}
EXPORT_SYMBOL(hci_chan_create);

void hci_chan_modify(struct hci_chan *chan,
			struct hci_ext_fs *tx_fs, struct hci_ext_fs *rx_fs)
{
	struct hci_cp_flow_spec_modify cp;

	chan->tx_fs = *tx_fs;
	chan->rx_fs = *rx_fs;
	cp.log_handle = cpu_to_le16(chan->ll_handle);
	cp.tx_fs.id = tx_fs->id;
	cp.tx_fs.type = tx_fs->type;
	cp.tx_fs.max_sdu = cpu_to_le16(tx_fs->max_sdu);
	cp.tx_fs.sdu_arr_time = cpu_to_le32(tx_fs->sdu_arr_time);
	cp.tx_fs.acc_latency = cpu_to_le32(tx_fs->acc_latency);
	cp.tx_fs.flush_to = cpu_to_le32(tx_fs->flush_to);
	cp.rx_fs.id = rx_fs->id;
	cp.rx_fs.type = rx_fs->type;
	cp.rx_fs.max_sdu = cpu_to_le16(rx_fs->max_sdu);
	cp.rx_fs.sdu_arr_time = cpu_to_le32(rx_fs->sdu_arr_time);
	cp.rx_fs.acc_latency = cpu_to_le32(rx_fs->acc_latency);
	cp.rx_fs.flush_to = cpu_to_le32(rx_fs->flush_to);
	hci_conn_hold(chan->conn);
	hci_send_cmd(chan->conn->hdev, HCI_OP_FLOW_SPEC_MODIFY, sizeof(cp),
									&cp);
}
EXPORT_SYMBOL(hci_chan_modify);

/* Drop all connection on the device */
void hci_conn_hash_flush(struct hci_dev *hdev, u8 is_process)
{
	struct hci_conn_hash *h = &hdev->conn_hash;
	struct list_head *p;

	BT_DBG("hdev %s", hdev->name);

	p = h->list.next;
	while (p != &h->list) {
		struct hci_conn *c;

		c = list_entry(p, struct hci_conn, list);
		p = p->next;

		c->state = BT_CLOSED;

		hci_proto_disconn_cfm(c, 0x16, is_process);
		hci_conn_del(c);
	}
}

/* Check pending connect attempts */
void hci_conn_check_pending(struct hci_dev *hdev)
{
	struct hci_conn *conn;

	BT_DBG("hdev %s", hdev->name);

	hci_dev_lock(hdev);

	conn = hci_conn_hash_lookup_state(hdev, ACL_LINK, BT_CONNECT2);
	if (conn)
		hci_acl_connect(conn);

	hci_dev_unlock(hdev);
}

void hci_conn_hold_device(struct hci_conn *conn)
{
	atomic_inc(&conn->devref);
}
EXPORT_SYMBOL(hci_conn_hold_device);

void hci_conn_put_device(struct hci_conn *conn)
{
	if (atomic_dec_and_test(&conn->devref))
		hci_conn_del_sysfs(conn);
}
EXPORT_SYMBOL(hci_conn_put_device);

int hci_get_conn_list(void __user *arg)
{
	struct hci_conn_list_req req, *cl;
	struct hci_conn_info *ci;
	struct hci_dev *hdev;
	struct list_head *p;
	int n = 0, size, err;

	if (copy_from_user(&req, arg, sizeof(req)))
		return -EFAULT;

	if (!req.conn_num || req.conn_num > (PAGE_SIZE * 2) / sizeof(*ci))
		return -EINVAL;

	size = sizeof(req) + req.conn_num * sizeof(*ci);

	cl = kmalloc(size, GFP_KERNEL);
	if (!cl)
		return -ENOMEM;

	hdev = hci_dev_get(req.dev_id);
	if (!hdev) {
		kfree(cl);
		return -ENODEV;
	}

	ci = cl->conn_info;

	hci_dev_lock_bh(hdev);
	list_for_each(p, &hdev->conn_hash.list) {
		register struct hci_conn *c;
		c = list_entry(p, struct hci_conn, list);

		bacpy(&(ci + n)->bdaddr, &c->dst);
		(ci + n)->handle = c->handle;
		(ci + n)->type  = c->type;
		(ci + n)->out   = c->out;
		(ci + n)->state = c->state;
		(ci + n)->link_mode = c->link_mode;
		if (c->type == SCO_LINK) {
			(ci + n)->mtu = hdev->sco_mtu;
			(ci + n)->cnt = hdev->sco_cnt;
			(ci + n)->pkts = hdev->sco_pkts;
		} else {
			(ci + n)->mtu = hdev->acl_mtu;
			(ci + n)->cnt = hdev->acl_cnt;
			(ci + n)->pkts = hdev->acl_pkts;
		}
		if (++n >= req.conn_num)
			break;
	}
	hci_dev_unlock_bh(hdev);

	cl->dev_id = hdev->id;
	cl->conn_num = n;
	size = sizeof(req) + n * sizeof(*ci);

	hci_dev_put(hdev);

	err = copy_to_user(arg, cl, size);
	kfree(cl);

	return err ? -EFAULT : 0;
}

int hci_get_conn_info(struct hci_dev *hdev, void __user *arg)
{
	struct hci_conn_info_req req;
	struct hci_conn_info ci;
	struct hci_conn *conn;
	char __user *ptr = arg + sizeof(req);

	if (copy_from_user(&req, arg, sizeof(req)))
		return -EFAULT;

	hci_dev_lock_bh(hdev);
	conn = hci_conn_hash_lookup_ba(hdev, req.type, &req.bdaddr);
	if (conn) {
		bacpy(&ci.bdaddr, &conn->dst);
		ci.handle = conn->handle;
		ci.type  = conn->type;
		ci.out   = conn->out;
		ci.state = conn->state;
		ci.link_mode = conn->link_mode;
		if (req.type == SCO_LINK) {
			ci.mtu = hdev->sco_mtu;
			ci.cnt = hdev->sco_cnt;
			ci.pkts = hdev->sco_pkts;
		} else {
			ci.mtu = hdev->acl_mtu;
			ci.cnt = hdev->acl_cnt;
			ci.pkts = hdev->acl_pkts;
		}
		ci.pending_sec_level = conn->pending_sec_level;
		ci.ssp_mode = conn->ssp_mode;
	}
	hci_dev_unlock_bh(hdev);

	if (!conn)
		return -ENOENT;

	return copy_to_user(ptr, &ci, sizeof(ci)) ? -EFAULT : 0;
}

int hci_get_auth_info(struct hci_dev *hdev, void __user *arg)
{
	struct hci_auth_info_req req;
	struct hci_conn *conn;

	if (copy_from_user(&req, arg, sizeof(req)))
		return -EFAULT;

	hci_dev_lock_bh(hdev);
	conn = hci_conn_hash_lookup_ba(hdev, ACL_LINK, &req.bdaddr);
	if (conn)
		req.type = conn->auth_type;
	hci_dev_unlock_bh(hdev);

	if (!conn)
		return -ENOENT;

	return copy_to_user(arg, &req, sizeof(req)) ? -EFAULT : 0;
}

int hci_set_auth_info(struct hci_dev *hdev, void __user *arg)
{
	struct hci_auth_info_req req;
	struct hci_conn *conn;

	if (copy_from_user(&req, arg, sizeof(req)))
		return -EFAULT;

	hci_dev_lock_bh(hdev);
	conn = hci_conn_hash_lookup_ba(hdev, ACL_LINK, &req.bdaddr);
	if (conn)
		conn->auth_type = req.type;
	hci_dev_unlock_bh(hdev);

	if (!conn)
		return -ENOENT;

	return copy_to_user(arg, &req, sizeof(req)) ? -EFAULT : 0;
}