hci_conn.c

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

   Written 2000,2001 by Maxim Krasnyansky <[email protected]>

   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/export.h>

#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
#include <net/bluetooth/a2mp.h>
#include <net/bluetooth/smp.h>

static void hci_le_create_connection(struct hci_conn *conn)
{
    struct hci_dev *hdev = conn->hdev;
    struct hci_cp_le_create_conn cp;

    conn->state = BT_CONNECT;
    conn->out = true;
    conn->link_mode |= HCI_LM_MASTER;
    conn->sec_level = BT_SECURITY_LOW;

    memset(&cp, 0, sizeof(cp));
    cp.scan_interval = __constant_cpu_to_le16(0x0060);
    cp.scan_window = __constant_cpu_to_le16(0x0030);
    bacpy(&cp.peer_addr, &conn->dst);
    cp.peer_addr_type = conn->dst_type;
    cp.conn_interval_min = __constant_cpu_to_le16(0x0028);
    cp.conn_interval_max = __constant_cpu_to_le16(0x0038);
    cp.supervision_timeout = __constant_cpu_to_le16(0x002a);
    cp.min_ce_len = __constant_cpu_to_le16(0x0000);
    cp.max_ce_len = __constant_cpu_to_le16(0x0000);

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

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

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

    BT_DBG("hcon %p", conn);

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

    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 |
                        __constant_cpu_to_le16(0x8000);
        }

        memcpy(conn->dev_class, ie->data.dev_class, 3);
        if (ie->data.ssp_mode > 0)
            set_bit(HCI_CONN_SSP_ENABLED, &conn->flags);
    }

    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_create_connection_cancel(struct hci_conn *conn)
{
    struct hci_cp_create_conn_cancel cp;

    BT_DBG("hcon %p", conn);

    if (conn->hdev->hci_ver < BLUETOOTH_VER_1_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)
{
    struct hci_cp_disconnect cp;

    BT_DBG("hcon %p", conn);

    conn->state = BT_DISCONN;

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

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

    BT_DBG("hcon %p", conn);

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

    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("hcon %p", conn);

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

    conn->attempt++;

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

    cp.tx_bandwidth   = __constant_cpu_to_le32(0x00001f40);
    cp.rx_bandwidth   = __constant_cpu_to_le32(0x00001f40);
    cp.max_latency    = __constant_cpu_to_le16(0xffff);
    cp.voice_setting  = cpu_to_le16(hdev->voice_setting);
    cp.retrans_effort = 0xff;

    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       = __constant_cpu_to_le16(0x0001);
    cp.max_ce_len       = __constant_cpu_to_le16(0x0001);

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

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("hcon %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);
}

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

    if (!sco)
        return;

    BT_DBG("hcon %p", conn);

    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(struct work_struct *work)
{
    struct hci_conn *conn = container_of(work, struct hci_conn,
                         disc_work.work);
    __u8 reason;

    BT_DBG("hcon %p state %s", conn, state_to_string(conn->state));

    if (atomic_read(&conn->refcnt))
        return;

    switch (conn->state) {
    case BT_CONNECT:
    case BT_CONNECT2:
        if (conn->out) {
            if (conn->type == ACL_LINK)
                hci_acl_create_connection_cancel(conn);
            else if (conn->type == LE_LINK)
                hci_le_create_connection_cancel(conn);
        }
        break;
    case BT_CONFIG:
    case BT_CONNECTED:
        reason = hci_proto_disconn_ind(conn);
        hci_acl_disconn(conn, reason);
        break;
    default:
        conn->state = BT_CLOSED;
        break;
    }
}

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

    BT_DBG("hcon %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))
        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        = __constant_cpu_to_le16(0);
        cp.min_remote_timeout = __constant_cpu_to_le16(0);
        cp.min_local_timeout  = __constant_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->flags)) {
        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      = __constant_cpu_to_le16(4);
        cp.timeout      = __constant_cpu_to_le16(1);
        hci_send_cmd(hdev, HCI_OP_SNIFF_MODE, sizeof(cp), &cp);
    }
}

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

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

    hci_conn_enter_sniff_mode(conn);
}

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

    hci_send_cmd(hdev, HCI_OP_USER_CONFIRM_REPLY, sizeof(conn->dst),
             &conn->dst);
}

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

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

    conn = kzalloc(sizeof(struct hci_conn), GFP_KERNEL);
    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->key_type = 0xff;

    set_bit(HCI_CONN_POWER_SAVE, &conn->flags);
    conn->disc_timeout = HCI_DISCONN_TIMEOUT;

    switch (type) {
    case ACL_LINK:
        conn->pkt_type = hdev->pkt_type & ACL_PTYPE_MASK;
        break;
    case SCO_LINK:
        if (lmp_esco_capable(hdev))
            conn->pkt_type = (hdev->esco_type & SCO_ESCO_MASK) |
                    (hdev->esco_type & EDR_ESCO_MASK);
        else
            conn->pkt_type = hdev->pkt_type & SCO_PTYPE_MASK;
        break;
    case ESCO_LINK:
        conn->pkt_type = hdev->esco_type & ~EDR_ESCO_MASK;
        break;
    }

    skb_queue_head_init(&conn->data_q);

    INIT_LIST_HEAD(&conn->chan_list);

    INIT_DELAYED_WORK(&conn->disc_work, hci_conn_timeout);
    setup_timer(&conn->idle_timer, hci_conn_idle, (unsigned long)conn);
    setup_timer(&conn->auto_accept_timer, hci_conn_auto_accept,
            (unsigned long) conn);

    atomic_set(&conn->refcnt, 0);

    hci_dev_hold(hdev);

    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);

    return conn;
}

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

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

    del_timer(&conn->idle_timer);

    cancel_delayed_work_sync(&conn->disc_work);

    del_timer(&conn->auto_accept_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);
        }
    }

    hci_chan_list_flush(conn);

    if (conn->amp_mgr)
        amp_mgr_put(conn->amp_mgr);

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

    skb_queue_purge(&conn->data_q);

    hci_conn_put_device(conn);

    hci_dev_put(hdev);

    if (conn->handle == 0)
        kfree(conn);

    return 0;
}

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

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

    read_lock(&hci_dev_list_lock);

    list_for_each_entry(d, &hci_dev_list, list) {
        if (!test_bit(HCI_UP, &d->flags) ||
            test_bit(HCI_RAW, &d->flags) ||
            d->dev_type != HCI_BREDR)
            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(&hci_dev_list_lock);
    return hdev;
}
EXPORT_SYMBOL(hci_get_route);

static struct hci_conn *hci_connect_le(struct hci_dev *hdev, bdaddr_t *dst,
                    u8 dst_type, u8 sec_level, u8 auth_type)
{
    struct hci_conn *le;

    le = hci_conn_hash_lookup_ba(hdev, LE_LINK, dst);
    if (!le) {
        le = hci_conn_hash_lookup_state(hdev, LE_LINK, BT_CONNECT);
        if (le)
            return ERR_PTR(-EBUSY);

        le = hci_conn_add(hdev, LE_LINK, dst);
        if (!le)
            return ERR_PTR(-ENOMEM);

        le->dst_type = bdaddr_to_le(dst_type);
        hci_le_create_connection(le);
    }

    le->pending_sec_level = sec_level;
    le->auth_type = auth_type;

    hci_conn_hold(le);

    return le;
}

static struct hci_conn *hci_connect_acl(struct hci_dev *hdev, bdaddr_t *dst,
                        u8 sec_level, u8 auth_type)
{
    struct hci_conn *acl;

    acl = hci_conn_hash_lookup_ba(hdev, ACL_LINK, dst);
    if (!acl) {
        acl = hci_conn_add(hdev, ACL_LINK, dst);
        if (!acl)
            return ERR_PTR(-ENOMEM);
    }

    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_create_connection(acl);
    }

    return acl;
}

static struct hci_conn *hci_connect_sco(struct hci_dev *hdev, int type,
                bdaddr_t *dst, u8 sec_level, u8 auth_type)
{
    struct hci_conn *acl;
    struct hci_conn *sco;

    acl = hci_connect_acl(hdev, dst, sec_level, auth_type);
    if (IS_ERR(acl))
        return acl;

    sco = hci_conn_hash_lookup_ba(hdev, type, dst);
    if (!sco) {
        sco = hci_conn_add(hdev, type, dst);
        if (!sco) {
            hci_conn_put(acl);
            return ERR_PTR(-ENOMEM);
        }
    }

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

    hci_conn_hold(sco);

    if (acl->state == BT_CONNECTED &&
        (sco->state == BT_OPEN || sco->state == BT_CLOSED)) {
        set_bit(HCI_CONN_POWER_SAVE, &acl->flags);
        hci_conn_enter_active_mode(acl, BT_POWER_FORCE_ACTIVE_ON);

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

        hci_sco_setup(acl, 0x00);
    }

    return sco;
}

/* Create SCO, ACL or LE connection. */
struct hci_conn *hci_connect(struct hci_dev *hdev, int type, bdaddr_t *dst,
                 __u8 dst_type, __u8 sec_level, __u8 auth_type)
{
    BT_DBG("%s dst %s type 0x%x", hdev->name, batostr(dst), type);

    switch (type) {
    case LE_LINK:
        return hci_connect_le(hdev, dst, dst_type, sec_level, auth_type);
    case ACL_LINK:
        return hci_connect_acl(hdev, dst, sec_level, auth_type);
    case SCO_LINK:
    case ESCO_LINK:
        return hci_connect_sco(hdev, type, dst, sec_level, auth_type);
    }

    return ERR_PTR(-EINVAL);
}

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

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

    return 1;
}

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

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

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

        cp.handle = cpu_to_le16(conn->handle);
        hci_send_cmd(conn->hdev, HCI_OP_AUTH_REQUESTED,
                 sizeof(cp), &cp);
        if (conn->key_type != 0xff)
            set_bit(HCI_CONN_REAUTH_PEND, &conn->flags);
    }

    return 0;
}

/* Encrypt the the link */
static void hci_conn_encrypt(struct hci_conn *conn)
{
    BT_DBG("hcon %p", conn);

    if (!test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &conn->flags)) {
        struct hci_cp_set_conn_encrypt cp;
        cp.handle  = cpu_to_le16(conn->handle);
        cp.encrypt = 0x01;
        hci_send_cmd(conn->hdev, HCI_OP_SET_CONN_ENCRYPT, sizeof(cp),
                 &cp);
    }
}

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

    if (conn->type == LE_LINK)
        return smp_conn_security(conn, sec_level);

    /* For sdp we don't need the link key. */
    if (sec_level == BT_SECURITY_SDP)
        return 1;

    /* For non 2.1 devices and low security level we don't need the link
       key. */
    if (sec_level == BT_SECURITY_LOW && !hci_conn_ssp_enabled(conn))
        return 1;

    /* For other security levels we need the link key. */
    if (!(conn->link_mode & HCI_LM_AUTH))
        goto auth;

    /* An authenticated combination key has sufficient security for any
       security level. */
    if (conn->key_type == HCI_LK_AUTH_COMBINATION)
        goto encrypt;

    /* An unauthenticated combination key has sufficient security for
       security level 1 and 2. */
    if (conn->key_type == HCI_LK_UNAUTH_COMBINATION &&
        (sec_level == BT_SECURITY_MEDIUM || sec_level == BT_SECURITY_LOW))
        goto encrypt;

    /* A combination key has always sufficient security for the security
       levels 1 or 2. High security level requires the combination key
       is generated using maximum PIN code length (16).
       For pre 2.1 units. */
    if (conn->key_type == HCI_LK_COMBINATION &&
        (sec_level != BT_SECURITY_HIGH || conn->pin_length == 16))
        goto encrypt;

auth:
    if (test_bit(HCI_CONN_ENCRYPT_PEND, &conn->flags))
        return 0;

    if (!hci_conn_auth(conn, sec_level, auth_type))
        return 0;

encrypt:
    if (conn->link_mode & HCI_LM_ENCRYPT)
        return 1;

    hci_conn_encrypt(conn);
    return 0;
}
EXPORT_SYMBOL(hci_conn_security);

/* Check secure link requirement */
int hci_conn_check_secure(struct hci_conn *conn, __u8 sec_level)
{
    BT_DBG("hcon %p", conn);

    if (sec_level != BT_SECURITY_HIGH)
        return 1; /* Accept if non-secure is required */

    if (conn->sec_level == BT_SECURITY_HIGH)
        return 1;

    return 0; /* Reject not secure link */
}
EXPORT_SYMBOL(hci_conn_check_secure);

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

    if (!test_and_set_bit(HCI_CONN_AUTH_PEND, &conn->flags)) {
        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;
}

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

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

    if (!test_and_set_bit(HCI_CONN_RSWITCH_PEND, &conn->flags)) {
        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("hcon %p mode %d", conn, conn->mode);

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

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

    if (!test_bit(HCI_CONN_POWER_SAVE, &conn->flags) && !force_active)
        goto timer;

    if (!test_and_set_bit(HCI_CONN_MODE_CHANGE_PEND, &conn->flags)) {
        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));
}

/* Drop all connection on the device */
void hci_conn_hash_flush(struct hci_dev *hdev)
{
    struct hci_conn_hash *h = &hdev->conn_hash;
    struct hci_conn *c, *n;

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

    list_for_each_entry_safe(c, n, &h->list, list) {
        c->state = BT_CLOSED;

        hci_proto_disconn_cfm(c, HCI_ERROR_LOCAL_HOST_TERM);
        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_create_connection(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 *c;
    struct hci_conn_list_req req, *cl;
    struct hci_conn_info *ci;
    struct hci_dev *hdev;
    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(hdev);
    list_for_each_entry(c, &hdev->conn_hash.list, 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 (++n >= req.conn_num)
            break;
    }
    hci_dev_unlock(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(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;
    }
    hci_dev_unlock(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(hdev);
    conn = hci_conn_hash_lookup_ba(hdev, ACL_LINK, &req.bdaddr);
    if (conn)
        req.type = conn->auth_type;
    hci_dev_unlock(hdev);

    if (!conn)
        return -ENOENT;

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

struct hci_chan *hci_chan_create(struct hci_conn *conn)
{
    struct hci_dev *hdev = conn->hdev;
    struct hci_chan *chan;

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

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

    chan->conn = conn;
    skb_queue_head_init(&chan->data_q);

    list_add_rcu(&chan->list, &conn->chan_list);

    return chan;
}

void hci_chan_del(struct hci_chan *chan)
{
    struct hci_conn *conn = chan->conn;
    struct hci_dev *hdev = conn->hdev;

    BT_DBG("%s hcon %p chan %p", hdev->name, conn, chan);

    list_del_rcu(&chan->list);

    synchronize_rcu();

    skb_queue_purge(&chan->data_q);
    kfree(chan);
}

void hci_chan_list_flush(struct hci_conn *conn)
{
    struct hci_chan *chan, *n;

    BT_DBG("hcon %p", conn);

    list_for_each_entry_safe(chan, n, &conn->chan_list, list)
        hci_chan_del(chan);
}