bt/stack/btm/btm_dev.cc

/******************************************************************************
 *
 *  Copyright (C) 1999-2012 Broadcom Corporation
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at:
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 ******************************************************************************/

/******************************************************************************
 *
 *  This file contains functions for the Bluetooth Device Manager
 *
 ******************************************************************************/

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <stddef.h>

#include "bt_types.h"
#include "device/include/controller.h"
#include "bt_common.h"
#include "hcimsgs.h"
#include "btu.h"
#include "btm_api.h"
#include "btm_int.h"
#include "hcidefs.h"
#include "l2c_api.h"

/*******************************************************************************
**
** Function         BTM_SecAddDevice
**
** Description      Add/modify device.  This function will be normally called
**                  during host startup to restore all required information
**                  stored in the NVRAM.
**
** Parameters:      bd_addr          - BD address of the peer
**                  dev_class        - Device Class
**                  bd_name          - Name of the peer device.  NULL if unknown.
**                  features         - Remote device's features (up to 3 pages). NULL if not known
**                  trusted_mask     - Bitwise OR of services that do not
**                                     require authorization. (array of uint32_t)
**                  link_key         - Connection link key. NULL if unknown.
**
** Returns          true if added OK, else false
**
*******************************************************************************/
bool    BTM_SecAddDevice (BD_ADDR bd_addr, DEV_CLASS dev_class, BD_NAME bd_name,
                          uint8_t *features, uint32_t trusted_mask[],
                          LINK_KEY link_key, uint8_t key_type, tBTM_IO_CAP io_cap,
                          uint8_t pin_length)
{
    BTM_TRACE_API("%s: link key type:%x", __func__, key_type);

    tBTM_SEC_DEV_REC *p_dev_rec = btm_find_dev (bd_addr);
    if (!p_dev_rec)
    {
        p_dev_rec = btm_sec_allocate_dev_rec();

        memcpy (p_dev_rec->bd_addr, bd_addr, BD_ADDR_LEN);
        p_dev_rec->hci_handle = BTM_GetHCIConnHandle (bd_addr, BT_TRANSPORT_BR_EDR);

#if (BLE_INCLUDED == TRUE)
        /* use default value for background connection params */
        /* update conn params, use default value for background connection params */
        memset(&p_dev_rec->conn_params, 0xff, sizeof(tBTM_LE_CONN_PRAMS));
#endif
    } else {
        /* "Bump" timestamp for existing record */
        p_dev_rec->timestamp = btm_cb.dev_rec_count++;

        /* TODO(eisenbach):
         * Small refactor, but leaving original logic for now.
         * On the surface, this does not make any sense at all. Why change the
         * bond state for an existing device here? This logic should be verified
         * as part of a larger refactor.
         */
        p_dev_rec->bond_type = BOND_TYPE_UNKNOWN;
    }

    if (dev_class)
        memcpy (p_dev_rec->dev_class, dev_class, DEV_CLASS_LEN);

    memset(p_dev_rec->sec_bd_name, 0, sizeof(tBTM_BD_NAME));

    if (bd_name && bd_name[0])
    {
        p_dev_rec->sec_flags |= BTM_SEC_NAME_KNOWN;
        strlcpy ((char *)p_dev_rec->sec_bd_name,
                 (char *)bd_name, BTM_MAX_REM_BD_NAME_LEN);
    }

    p_dev_rec->num_read_pages = 0;
    if (features)
    {
        bool found = false;
        memcpy (p_dev_rec->features, features, sizeof (p_dev_rec->features));
        for (int i = HCI_EXT_FEATURES_PAGE_MAX; !found && i >= 0; i--)
        {
            for (int j = 0; j < HCI_FEATURE_BYTES_PER_PAGE; j++)
            {
                if (p_dev_rec->features[i][j] != 0)
                {
                    found = true;
                    p_dev_rec->num_read_pages = i + 1;
                    break;
                }
            }
        }
    } else {
        memset (p_dev_rec->features, 0, sizeof (p_dev_rec->features));
    }

    BTM_SEC_COPY_TRUSTED_DEVICE(trusted_mask, p_dev_rec->trusted_mask);

    if (link_key)
    {
        BTM_TRACE_EVENT ("%s: BDA: %02x:%02x:%02x:%02x:%02x:%02x", __func__,
                          bd_addr[0], bd_addr[1], bd_addr[2],
                          bd_addr[3], bd_addr[4], bd_addr[5]);
        p_dev_rec->sec_flags |= BTM_SEC_LINK_KEY_KNOWN;
        memcpy (p_dev_rec->link_key, link_key, LINK_KEY_LEN);
        p_dev_rec->link_key_type = key_type;
        p_dev_rec->pin_code_length = pin_length;

        if (pin_length >= 16 ||
            key_type == BTM_LKEY_TYPE_AUTH_COMB ||
            key_type == BTM_LKEY_TYPE_AUTH_COMB_P_256) {
            // Set the flag if the link key was made by using either a 16 digit
            // pin or MITM.
            p_dev_rec->sec_flags |= BTM_SEC_16_DIGIT_PIN_AUTHED | BTM_SEC_LINK_KEY_AUTHED;
        }
    }

#if (BTIF_MIXED_MODE_INCLUDED == TRUE)
    if (key_type  < BTM_MAX_PRE_SM4_LKEY_TYPE)
        p_dev_rec->sm4 = BTM_SM4_KNOWN;
    else
        p_dev_rec->sm4 = BTM_SM4_TRUE;
#endif

    p_dev_rec->rmt_io_caps = io_cap;
    p_dev_rec->device_type |= BT_DEVICE_TYPE_BREDR;

    return true;
}


/*******************************************************************************
**
** Function         BTM_SecDeleteDevice
**
** Description      Free resources associated with the device.
**
** Parameters:      bd_addr          - BD address of the peer
**
** Returns          true if removed OK, false if not found or ACL link is active
**
*******************************************************************************/
bool    BTM_SecDeleteDevice (BD_ADDR bd_addr)
{
    if (BTM_IsAclConnectionUp(bd_addr, BT_TRANSPORT_LE) ||
        BTM_IsAclConnectionUp(bd_addr, BT_TRANSPORT_BR_EDR))
    {
        BTM_TRACE_WARNING("%s FAILED: Cannot Delete when connection is active", __func__);
        return false;
    }

    tBTM_SEC_DEV_REC *p_dev_rec = btm_find_dev(bd_addr);
    if (p_dev_rec != NULL)
    {
        btm_sec_free_dev(p_dev_rec);
        /* Tell controller to get rid of the link key, if it has one stored */
        BTM_DeleteStoredLinkKey (p_dev_rec->bd_addr, NULL);
    }

    return true;
}

/*******************************************************************************
**
** Function         BTM_SecClearSecurityFlags
**
** Description      Reset the security flags (mark as not-paired) for a given
**                  remove device.
**
*******************************************************************************/
extern void BTM_SecClearSecurityFlags (BD_ADDR bd_addr)
{
    tBTM_SEC_DEV_REC *p_dev_rec = btm_find_dev(bd_addr);
    if (p_dev_rec == NULL)
        return;

    p_dev_rec->sec_flags = 0;
    p_dev_rec->sec_state = BTM_SEC_STATE_IDLE;
    p_dev_rec->sm4 = BTM_SM4_UNKNOWN;
}

/*******************************************************************************
**
** Function         BTM_SecReadDevName
**
** Description      Looks for the device name in the security database for the
**                  specified BD address.
**
** Returns          Pointer to the name or NULL
**
*******************************************************************************/
char *BTM_SecReadDevName (BD_ADDR bd_addr)
{
    char *p_name = NULL;
    tBTM_SEC_DEV_REC *p_srec;

    if ((p_srec = btm_find_dev(bd_addr)) != NULL)
        p_name = (char *)p_srec->sec_bd_name;

    return(p_name);
}

bool is_bd_addr_equal(void *data, void *context)
{
    tBTM_SEC_DEV_REC *p_dev_rec = static_cast<tBTM_SEC_DEV_REC *>(data);
    BD_ADDR *bd_addr = static_cast<BD_ADDR *>(context);

    if (!memcmp(p_dev_rec->bd_addr, bd_addr, BD_ADDR_LEN))
        return false;

    return true;
}

/*******************************************************************************
**
** Function         btm_sec_alloc_dev
**
** Description      Look for the record in the device database for the record
**                  with specified address
**
** Returns          Pointer to the record or NULL
**
*******************************************************************************/
tBTM_SEC_DEV_REC *btm_sec_alloc_dev (BD_ADDR bd_addr)
{
    tBTM_INQ_INFO    *p_inq_info;
    BTM_TRACE_EVENT ("btm_sec_alloc_dev");

    tBTM_SEC_DEV_REC *p_dev_rec = btm_sec_allocate_dev_rec();

    /* Check with the BT manager if details about remote device are known */
    /* outgoing connection */
    if ((p_inq_info = BTM_InqDbRead(bd_addr)) != NULL)
    {
        memcpy (p_dev_rec->dev_class, p_inq_info->results.dev_class, DEV_CLASS_LEN);

#if (BLE_INCLUDED == TRUE)
        p_dev_rec->device_type = p_inq_info->results.device_type;
        p_dev_rec->ble.ble_addr_type = p_inq_info->results.ble_addr_type;
#endif
    }
    else if (!memcmp (bd_addr, btm_cb.connecting_bda, BD_ADDR_LEN))
            memcpy (p_dev_rec->dev_class, btm_cb.connecting_dc, DEV_CLASS_LEN);

#if (BLE_INCLUDED == TRUE)
    /* update conn params, use default value for background connection params */
    memset(&p_dev_rec->conn_params, 0xff, sizeof(tBTM_LE_CONN_PRAMS));
#endif

    memcpy (p_dev_rec->bd_addr, bd_addr, BD_ADDR_LEN);

#if (BLE_INCLUDED == TRUE)
    p_dev_rec->ble_hci_handle = BTM_GetHCIConnHandle (bd_addr, BT_TRANSPORT_LE);
#endif
    p_dev_rec->hci_handle = BTM_GetHCIConnHandle (bd_addr, BT_TRANSPORT_BR_EDR);

    return(p_dev_rec);
}


/*******************************************************************************
**
** Function         btm_sec_free_dev
**
** Description      Mark device record as not used
**
*******************************************************************************/
void btm_sec_free_dev (tBTM_SEC_DEV_REC *p_dev_rec)
{
#if (BLE_INCLUDED == TRUE)
    /* Clear out any saved BLE keys */
    btm_sec_clear_ble_keys (p_dev_rec);
#endif
    list_remove(btm_cb.sec_dev_rec, p_dev_rec);
}

/*******************************************************************************
**
** Function         btm_dev_support_switch
**
** Description      This function is called by the L2CAP to check if remote
**                  device supports role switch
**
** Parameters:      bd_addr       - Address of the peer device
**
** Returns          true if device is known and role switch is supported
**
*******************************************************************************/
bool    btm_dev_support_switch (BD_ADDR bd_addr)
{
    tBTM_SEC_DEV_REC  *p_dev_rec;
    uint8_t xx;
    bool    feature_empty = true;

#if (BTM_SCO_INCLUDED == TRUE)
    /* Role switch is not allowed if a SCO is up */
    if (btm_is_sco_active_by_bdaddr(bd_addr))
        return(false);
#endif
    p_dev_rec = btm_find_dev (bd_addr);
    if (p_dev_rec && controller_get_interface()->supports_master_slave_role_switch())
    {
        if (HCI_SWITCH_SUPPORTED(p_dev_rec->features[HCI_EXT_FEATURES_PAGE_0]))
        {
            BTM_TRACE_DEBUG("btm_dev_support_switch return true (feature found)");
            return (true);
        }

        /* If the feature field is all zero, we never received them */
        for (xx = 0 ; xx < BD_FEATURES_LEN ; xx++)
        {
            if (p_dev_rec->features[HCI_EXT_FEATURES_PAGE_0][xx] != 0x00)
            {
                feature_empty = false; /* at least one is != 0 */
                break;
            }
        }

        /* If we don't know peer's capabilities, assume it supports Role-switch */
        if (feature_empty)
        {
            BTM_TRACE_DEBUG("btm_dev_support_switch return true (feature empty)");
            return (true);
        }
    }

    BTM_TRACE_DEBUG("btm_dev_support_switch return false");
    return(false);
}

bool is_handle_equal(void *data, void *context)
{
    tBTM_SEC_DEV_REC *p_dev_rec = static_cast<tBTM_SEC_DEV_REC *>(data);
    uint16_t *handle = static_cast<uint16_t *>(context);

    if (p_dev_rec->hci_handle == *handle
#if (BLE_INCLUDED == TRUE)
     || p_dev_rec->ble_hci_handle == *handle
#endif
     )
        return false;

    return true;
}

/*******************************************************************************
**
** Function         btm_find_dev_by_handle
**
** Description      Look for the record in the device database for the record
**                  with specified handle
**
** Returns          Pointer to the record or NULL
**
*******************************************************************************/
tBTM_SEC_DEV_REC *btm_find_dev_by_handle (uint16_t handle)
{
    list_node_t *n = list_foreach(btm_cb.sec_dev_rec, is_handle_equal, &handle);
    if (n)
        return static_cast<tBTM_SEC_DEV_REC *>(list_node(n));

    return NULL;
}

bool is_address_equal(void *data, void *context)
{
    tBTM_SEC_DEV_REC *p_dev_rec = static_cast<tBTM_SEC_DEV_REC *>(data);
    BD_ADDR *bd_addr = static_cast<BD_ADDR *>(context);

    if (!memcmp (p_dev_rec->bd_addr, *bd_addr, BD_ADDR_LEN))
        return false;
#if (BLE_INCLUDED == TRUE)
    // If a LE random address is looking for device record
    if (!memcmp(p_dev_rec->ble.pseudo_addr, *bd_addr, BD_ADDR_LEN))
        return false;

    if (btm_ble_addr_resolvable(*bd_addr, p_dev_rec))
        return false;
#endif
    return true;
}

/*******************************************************************************
**
** Function         btm_find_dev
**
** Description      Look for the record in the device database for the record
**                  with specified BD address
**
** Returns          Pointer to the record or NULL
**
*******************************************************************************/
tBTM_SEC_DEV_REC *btm_find_dev(const BD_ADDR bd_addr)
{
    if (!bd_addr)
        return NULL;

    list_node_t *n = list_foreach(btm_cb.sec_dev_rec, is_address_equal, (void*)bd_addr);
    if (n)
        return static_cast<tBTM_SEC_DEV_REC *>(list_node(n));

    return NULL;
}

/*******************************************************************************
**
** Function         btm_consolidate_dev
5**
** Description      combine security records if identified as same peer
**
** Returns          none
**
*******************************************************************************/
void btm_consolidate_dev(tBTM_SEC_DEV_REC *p_target_rec)
{
#if (BLE_INCLUDED == TRUE)
    tBTM_SEC_DEV_REC temp_rec = *p_target_rec;

    BTM_TRACE_DEBUG("%s", __func__);

    list_node_t *end = list_end(btm_cb.sec_dev_rec);
    for (list_node_t *node = list_begin(btm_cb.sec_dev_rec); node != end; node = list_next(node)) {
        tBTM_SEC_DEV_REC *p_dev_rec =
            static_cast<tBTM_SEC_DEV_REC *>(list_node(node));

        if (p_target_rec == p_dev_rec)
            continue;

        if (!memcmp (p_dev_rec->bd_addr, p_target_rec->bd_addr, BD_ADDR_LEN))
        {
            memcpy(p_target_rec, p_dev_rec, sizeof(tBTM_SEC_DEV_REC));
            p_target_rec->ble = temp_rec.ble;
            p_target_rec->ble_hci_handle = temp_rec.ble_hci_handle;
            p_target_rec->enc_key_size = temp_rec.enc_key_size;
            p_target_rec->conn_params = temp_rec.conn_params;
            p_target_rec->device_type |= temp_rec.device_type;
            p_target_rec->sec_flags |= temp_rec.sec_flags;

            p_target_rec->new_encryption_key_is_p256 = temp_rec.new_encryption_key_is_p256;
            p_target_rec->no_smp_on_br = temp_rec.no_smp_on_br;
            p_target_rec->bond_type = temp_rec.bond_type;

            /* remove the combined record */
            list_remove(btm_cb.sec_dev_rec, p_dev_rec);
            break;
        }

        /* an RPA device entry is a duplicate of the target record */
        if (btm_ble_addr_resolvable(p_dev_rec->bd_addr, p_target_rec))
        {
            if (memcmp(p_target_rec->ble.pseudo_addr, p_dev_rec->bd_addr, BD_ADDR_LEN) == 0)
            {
                p_target_rec->ble.ble_addr_type = p_dev_rec->ble.ble_addr_type;
                p_target_rec->device_type |= p_dev_rec->device_type;

                /* remove the combined record */
                list_remove(btm_cb.sec_dev_rec, p_dev_rec);
            }
            break;
        }
    }
#endif
}

/*******************************************************************************
**
** Function         btm_find_or_alloc_dev
**
** Description      Look for the record in the device database for the record
**                  with specified BD address
**
** Returns          Pointer to the record or NULL
**
*******************************************************************************/
tBTM_SEC_DEV_REC *btm_find_or_alloc_dev (BD_ADDR bd_addr)
{
    tBTM_SEC_DEV_REC *p_dev_rec;
    BTM_TRACE_EVENT ("btm_find_or_alloc_dev");
    if ((p_dev_rec = btm_find_dev (bd_addr)) == NULL)
    {

        /* Allocate a new device record or reuse the oldest one */
        p_dev_rec = btm_sec_alloc_dev (bd_addr);
    }
    return(p_dev_rec);
}

/*******************************************************************************
**
** Function         btm_find_oldest_dev_rec
**
** Description      Locates the oldest device in use. It first looks for
**                  the oldest non-paired device.  If all devices are paired it
**                  returns the oldest paired device.
**
** Returns          Pointer to the record or NULL
**
*******************************************************************************/
static tBTM_SEC_DEV_REC* btm_find_oldest_dev_rec (void)
{
    tBTM_SEC_DEV_REC *p_oldest = NULL;
    uint32_t ts_oldest = 0xFFFFFFFF;
    tBTM_SEC_DEV_REC *p_oldest_paired = NULL;
    uint32_t ts_oldest_paired = 0xFFFFFFFF;

    list_node_t *end = list_end(btm_cb.sec_dev_rec);
    for (list_node_t *node = list_begin(btm_cb.sec_dev_rec); node != end; node = list_next(node)) {
        tBTM_SEC_DEV_REC *p_dev_rec =
            static_cast<tBTM_SEC_DEV_REC *>(list_node(node));

        if ((p_dev_rec->sec_flags & (BTM_SEC_LINK_KEY_KNOWN | BTM_SEC_LE_LINK_KEY_KNOWN)) == 0) {
            // Device is not paired
            if (p_dev_rec->timestamp < ts_oldest) {
                p_oldest = p_dev_rec;
                ts_oldest = p_dev_rec->timestamp;
            }
        } else {
            // Paired device
            if (p_dev_rec->timestamp < ts_oldest_paired) {
                p_oldest_paired = p_dev_rec;
                ts_oldest_paired = p_dev_rec->timestamp;
            }
        }
    }

    // If we did not find any non-paired devices, use the oldest paired one...
    if (ts_oldest == 0xFFFFFFFF)
        p_oldest = p_oldest_paired;

    return p_oldest;
}

/*******************************************************************************
**
** Function         btm_sec_allocate_dev_rec
**
** Description      Attempts to allocate a new device record. If we have
**                  exceeded the maximum number of allowable records to
**                  allocate, the oldest record will be deleted to make room
**                  for the new record.
**
** Returns          Pointer to the newly allocated record
**
*******************************************************************************/
tBTM_SEC_DEV_REC* btm_sec_allocate_dev_rec(void)
{
    tBTM_SEC_DEV_REC *p_dev_rec = NULL;

    if (list_length(btm_cb.sec_dev_rec) > BTM_SEC_MAX_DEVICE_RECORDS)
    {
        p_dev_rec = btm_find_oldest_dev_rec();
        list_remove(btm_cb.sec_dev_rec, p_dev_rec);
    }

    p_dev_rec =
        static_cast<tBTM_SEC_DEV_REC *>(osi_calloc(sizeof(tBTM_SEC_DEV_REC)));
    list_append(btm_cb.sec_dev_rec, p_dev_rec);

    // Initialize defaults
    p_dev_rec->sec_flags = BTM_SEC_IN_USE;
    p_dev_rec->bond_type = BOND_TYPE_UNKNOWN;
    p_dev_rec->timestamp = btm_cb.dev_rec_count++;

    return p_dev_rec;
}

/*******************************************************************************
**
** Function         btm_get_bond_type_dev
**
** Description      Get the bond type for a device in the device database
**                  with specified BD address
**
** Returns          The device bond type if known, otherwise BOND_TYPE_UNKNOWN
**
*******************************************************************************/
tBTM_BOND_TYPE btm_get_bond_type_dev(BD_ADDR bd_addr)
{
    tBTM_SEC_DEV_REC *p_dev_rec = btm_find_dev(bd_addr);

    if (p_dev_rec == NULL)
        return BOND_TYPE_UNKNOWN;

    return p_dev_rec->bond_type;
}

/*******************************************************************************
**
** Function         btm_set_bond_type_dev
**
** Description      Set the bond type for a device in the device database
**                  with specified BD address
**
** Returns          true on success, otherwise false
**
*******************************************************************************/
bool    btm_set_bond_type_dev(BD_ADDR bd_addr, tBTM_BOND_TYPE bond_type)
{
    tBTM_SEC_DEV_REC *p_dev_rec = btm_find_dev(bd_addr);

    if (p_dev_rec == NULL)
        return false;

    p_dev_rec->bond_type = bond_type;
    return true;
}