Swift Pairing for custom gatt service

[bscdb]

Hi,

I am using custom gatt service & I have included some of the code which supports swift pairing from ble_hid_mouse example. Here is my sniffer log -

mtu_log.pcapng

& the jlink rtt log -

paired - Copy.txt

For my application, the MTU size is 32 & data length is 36.

Windows keeps negotiating the size to be 512.

After I pair to the peripheral by connecting through the Windows bluetooth menu, it takes 1 minute to establish the ble connection & start data communication. If I dont pair, then the connection is quick. Now I know you will tell me the app has to make a connection. But I would also like to support manual pairing. Our device gets bricked if someone accidentally pairs with the device through Windows bluetooth menu. To avoid this I had to add the swift pairing support.

How do I expedite the connection on Windows for swift pairing? (note the same firmware without swift pairing feature works on Android OS perfectly fine with or without pairing.)

[Simonr]

Hi

Can you try adding a small delay in nrf_ble_gatt.c as shown below? This is supposed to avoid an LMP_RESPONSE_TIMEOUT, which your issue might be a variant of.

static void on_connected_evt(nrf_ble_gatt_t * p_gatt, ble_evt_t const * p_ble_evt)

{

…

        nrf_delay_ms(100); // #include "nrf_delay.h"

        err_code = sd_ble_gattc_exchange_mtu_request(conn_handle, p_link->att_mtu_desired);

…

}

Best regards,

Simon

[bscdb]

Now it takes more than a minute to connect.  Behavior is still the same..

Here are the logs - 

1. Added delay along with the above 4 lines

with_delay_and_4_lines.pcapng

RTT_with_delay_and_4_lines.txt

2. Added delay only

with_delay.pcapng

RTT_with_delay.txt

In both cases, the peripheral connects to Windows OS but it takes more than a minute.

I also tried increasing/decreasing the time in these 2 lines, but no luck

opt.gap_opt.auth_payload_timeout.auth_payload_timeout = 3000;

nrf_delay_ms(100);

[Kenneth]

Have you done any changes to peer_manager_handler.c or the modules it is using? I don't expect you have, but ask anyways.

Have you set PM_HANDLER_SEC_DELAY_MS to anything beside 0?

Can you confirm you are using S132v6.1.1?

Are you somehow initiating security procedure on connected event manually by for instance calling pm_handler_secure_on_connection() in your application?

From the log of "with_delay_and_4_lines.pcapng" I can see that the LL_LENGTH_REQ is sent from the peripheral after ~20ms. This means that the 100ms delay was not run, so I suggest to add the 100ms delay in the start of on_connected_evt(), e.g.:

static void on_connected_evt(nrf_ble_gatt_t * p_gatt, ble_evt_t const * p_ble_evt)
{
nrf_delay_ms(100); // Place it in the start of function, #include "nrf_delay.h"
…
…
}

I assume the real problem here is the LL_PING_RSP that is always sent from the master without any preceding LL_PING_REQ. What details can you provide about the Windows 10 version you are using? https://en.wikipedia.org/wiki/Template:Windows_10_versions 

Have you tried updating Windows 10 to the latest version? Are all BT drivers updated?

Best regards,
Kenneth

[bscdb]

Hi Kenneth,

Answers to your questions -

I did not make any changes to peer_manager_handler.c.

PM_HANDLER_SEC_DELAY_MS is set to 0 in sdk_config.h

I'm using S132 from SDK16.0, dont know the version though.

Security procedure is not initiated manually.

Here are the new logs-

https://www.dropbox.com/s/nyj104bcryw8cg4/log_4th_may.pcapng?dl=0

https://www.dropbox.com/s/jlq7o3u5ei37t6r/rtt_log_4th_may.txt?dl=0

The sniffer trace looks different. I think you are right about LL_PING_RSP.

My Windows Specifications-

& now I have updated to 

Logs after updating -

https://www.dropbox.com/s/suasjwkssatsqkt/log_after_update.pcapng?dl=0

https://www.dropbox.com/s/yx0opw4vu4guvh7/rt_log_after_update.txt?dl=0

[Kenneth]

I think the main problem here is that the slave seem to always send a "Security Request: AuthReq: Bonding", which should not be necessary, since the link is already encrypted or in the process of being encrypted. I think that is what is causing the master to misbehave by sending a LL_PING_RSP later.

If you open any of the other SDK examples as-is that support bonding, you will see that it is not sending a "Security Request: AuthReq: Bonding". So we need to try to find out what is causing this in your application.

Can you provide the source for peer_manager_init(), sys_evt_dispatch(), ble_evt_dispatch(),  and pm_evt_handler()?

Is it possible that you are deleting bonds here somewhere?

*maybe check this first* Is it possible you are calling pm_conn_secure() somewhere?

Can you provide your defines of FDS*/FSTORAGE* in sdk_config.h?

What security level have you set for your various characteristics and services? For instance have you set BLE_GAP_CONN_SEC_MODE_SET_ENC_NO_MITM() or other? See ble_gap.h for a list of available BLE_GAP_CONN_SEC_MODE_SET_MACROS.

Best regards,
Kenneth

[bscdb]

Ahh I see, do you need the code snippets for peer_manager_init(), sys_evt_dispatch() and pm_evt_handler() or do you need the location where these are being called?

static void peer_manager_init()
{
    ble_gap_sec_params_t sec_param;
    ret_code_t           err_code;
    err_code = pm_init();
    APP_ERROR_CHECK(err_code);
    memset(&sec_param, 0, sizeof(ble_gap_sec_params_t));
    // Security parameters to be used for all security procedures.
    sec_param.bond           = SEC_PARAM_BOND;
    sec_param.mitm           = SEC_PARAM_MITM;
    sec_param.lesc           = SEC_PARAM_LESC;
    sec_param.keypress       = SEC_PARAM_KEYPRESS;
    sec_param.io_caps        = SEC_PARAM_IO_CAPABILITIES;
    sec_param.oob            = SEC_PARAM_OOB;
    sec_param.min_key_size   = SEC_PARAM_MIN_KEY_SIZE;
    sec_param.max_key_size   = SEC_PARAM_MAX_KEY_SIZE;
    sec_param.kdist_own.enc  = 1;
    sec_param.kdist_own.id   = 1;
    sec_param.kdist_peer.enc = 1;
    sec_param.kdist_peer.id  = 1;
    err_code = pm_sec_params_set(&sec_param);
    APP_ERROR_CHECK(err_code);
    err_code = pm_register(pm_evt_handler);
    APP_ERROR_CHECK(err_code);
}

#define SEC_PARAM_BOND                  1                              /**< Perform bonding. */
#define SEC_PARAM_MITM                  0                                           /**< Man In The Middle protection not required. */
#define SEC_PARAM_LESC                  0                                           /**< LE Secure Connections not enabled. */
#define SEC_PARAM_KEYPRESS              0                                           /**< Keypress notifications not enabled. */
#define SEC_PARAM_IO_CAPABILITIES       BLE_GAP_IO_CAPS_NONE                        /**< No I/O capabilities. */
#define SEC_PARAM_OOB                   0                                           /**< Out Of Band data not available. */
#define SEC_PARAM_MIN_KEY_SIZE          7                                           /**< Minimum encryption key size. */
#define SEC_PARAM_MAX_KEY_SIZE          16                                          /**< Maximum encryption key size. */

I couldnt find sys_evt_dispatch() in my project.

static void pm_evt_handler(pm_evt_t const * p_evt)
{
	ret_code_t err_code;
    pm_handler_on_pm_evt(p_evt);
    pm_handler_flash_clean(p_evt);
	/*not included*/
	switch (p_evt->evt_id)
    {
		case PM_EVT_BONDED_PEER_CONNECTED:
        {
            NRF_LOG_INFO("PM_EVT_BONDED_PEER_CONNECTED - Connected to a previously bonded device.");
        } break;
		case PM_EVT_CONN_SEC_START:
			NRF_LOG_INFO("PM_EVT_CONN_SEC_START");
		break;
		case PM_EVT_CONN_SEC_SUCCEEDED:
        {
            NRF_LOG_INFO("PM_EVT_CONN_SEC_SUCCEEDED - Connection secured: role: %d, conn_handle: 0x%x, procedure: %d.", ble_conn_state_role(p_evt->conn_handle),
                         p_evt->conn_handle, p_evt->params.conn_sec_succeeded.procedure);
        } break;
		case PM_EVT_CONN_SEC_FAILED:
        {
			NRF_LOG_INFO("PM_EVT_CONN_SEC_FAILED");
            /* Often, when securing fails, it shouldn't be restarted, for security reasons. Other times, it can be restarted directly.
             * Sometimes it can be restarted, but only after changing some Security Parameters. Sometimes, it cannot be restarted until the link is disconnected and reconnected.
             * Sometimes it is impossible, to secure the link, or the peer device does not support it. How to handle this error is highly application dependent. */
        } break;
		case PM_EVT_CONN_SEC_CONFIG_REQ:
        {
			NRF_LOG_INFO("PM_EVT_CONN_SEC_CONFIG_REQ");
            // Reject pairing request from an already bonded peer.
            pm_conn_sec_config_t conn_sec_config = {.allow_repairing = true};
            pm_conn_sec_config_reply(p_evt->conn_handle, &conn_sec_config);
        } break;
		case PM_EVT_CONN_SEC_PARAMS_REQ:
			NRF_LOG_INFO("PM_EVT_CONN_SEC_PARAMS_REQ");
		break;
		case PM_EVT_STORAGE_FULL:
        {
			NRF_LOG_INFO("PM_EVT_STORAGE_FULL");
            // Run garbage collection on the flash.
            err_code = fds_gc();
            if (err_code == FDS_ERR_NO_SPACE_IN_QUEUES)
            {
                // Retry.
            }
            else
            {
                APP_ERROR_CHECK(err_code);
            }
        } break;
		case PM_EVT_ERROR_UNEXPECTED:
        {
			NRF_LOG_INFO("PM_EVT_ERROR_UNEXPECTED");
            // Assert.
            APP_ERROR_CHECK(p_evt->params.error_unexpected.error);
        } break;
		case PM_EVT_PEER_DATA_UPDATE_SUCCEEDED:
			NRF_LOG_INFO("PM_EVT_PEER_DATA_UPDATE_SUCCEEDED");
			if (p_evt->params.peer_data_update_succeeded.flash_changed && (p_evt->params.peer_data_update_succeeded.data_id == PM_PEER_DATA_ID_BONDING))
            {
                NRF_LOG_INFO("New Bond, add the peer to the whitelist if possible");
				// Note: You should check on what kind of white list policy your application should use.
                whitelist_set(PM_PEER_ID_LIST_SKIP_NO_ID_ADDR);	/*For Quest*/
            }
        break;
		case PM_EVT_PEER_DATA_UPDATE_FAILED:
        {
			NRF_LOG_INFO("PM_EVT_PEER_DATA_UPDATE_FAILED");
            // Assert.
            APP_ERROR_CHECK(p_evt->params.peer_data_update_failed.error);
        } break;		
		case PM_EVT_PEER_DELETE_SUCCEEDED:
			NRF_LOG_INFO("PM_EVT_PEER_DELETE_SUCCEEDED");
		break;
        case PM_EVT_PEERS_DELETE_SUCCEEDED:
			NRF_LOG_INFO("PM_EVT_PEERS_DELETE_SUCCEEDED");
            advertising_start(false);
        break;		
		case PM_EVT_PEER_DELETE_FAILED:
        {
			NRF_LOG_INFO("PM_EVT_PEER_DELETE_FAILED");
            // Assert.
            APP_ERROR_CHECK(p_evt->params.peer_delete_failed.error);
        } break;
		case PM_EVT_PEERS_DELETE_FAILED:
        {
			NRF_LOG_INFO("PM_EVT_PEERS_DELETE_FAILED");
            // Assert.
            APP_ERROR_CHECK(p_evt->params.peers_delete_failed_evt.error);
        } break;
        case PM_EVT_LOCAL_DB_CACHE_APPLIED:
			NRF_LOG_INFO("PM_EVT_LOCAL_DB_CACHE_APPLIED");
		break;
        case PM_EVT_LOCAL_DB_CACHE_APPLY_FAILED:
			NRF_LOG_INFO("PM_EVT_LOCAL_DB_CACHE_APPLY_FAILED");
		break;
            // This can happen when the local DB has changed.
        case PM_EVT_SERVICE_CHANGED_IND_SENT:
			NRF_LOG_INFO("PM_EVT_SERVICE_CHANGED_IND_SENT");
		break;
        case PM_EVT_SERVICE_CHANGED_IND_CONFIRMED:
			NRF_LOG_INFO("PM_EVT_SERVICE_CHANGED_IND_CONFIRMED");
		break;
		case PM_EVT_SLAVE_SECURITY_REQ:
			NRF_LOG_INFO("PM_EVT_SLAVE_SECURITY_REQ");
		break;
		case PM_EVT_FLASH_GARBAGE_COLLECTED:
			NRF_LOG_INFO("PM_EVT_FLASH_GARBAGE_COLLECTED");
		break;
		case PM_EVT_FLASH_GARBAGE_COLLECTION_FAILED:
			NRF_LOG_INFO("PM_EVT_FLASH_GARBAGE_COLLECTION_FAILED");
		break;
        default:
            break;
	}
}

FDS defines -

// <e> FDS_ENABLED - fds - Flash data storage module
//==========================================================
#ifndef FDS_ENABLED
#define FDS_ENABLED 1
#endif
// <h> Pages - Virtual page settings

// <i> Configure the number of virtual pages to use and their size.
//==========================================================
// <o> FDS_VIRTUAL_PAGES - Number of virtual flash pages to use. 
// <i> One of the virtual pages is reserved by the system for garbage collection.
// <i> Therefore, the minimum is two virtual pages: one page to store data and one page to be used by the system for garbage collection.
// <i> The total amount of flash memory that is used by FDS amounts to @ref FDS_VIRTUAL_PAGES * @ref FDS_VIRTUAL_PAGE_SIZE * 4 bytes.

#ifndef FDS_VIRTUAL_PAGES
#define FDS_VIRTUAL_PAGES 3
#endif

// <o> FDS_VIRTUAL_PAGE_SIZE  - The size of a virtual flash page.
 

// <i> Expressed in number of 4-byte words.
// <i> By default, a virtual page is the same size as a physical page.
// <i> The size of a virtual page must be a multiple of the size of a physical page.
// <1024=> 1024 
// <2048=> 2048 

#ifndef FDS_VIRTUAL_PAGE_SIZE
#define FDS_VIRTUAL_PAGE_SIZE 1024
#endif

// <o> FDS_VIRTUAL_PAGES_RESERVED - The number of virtual flash pages that are used by other modules. 
// <i> FDS module stores its data in the last pages of the flash memory.
// <i> By setting this value, you can move flash end address used by the FDS.
// <i> As a result the reserved space can be used by other modules.

#ifndef FDS_VIRTUAL_PAGES_RESERVED
#define FDS_VIRTUAL_PAGES_RESERVED 0
#endif

// </h> 
//==========================================================

// <h> Backend - Backend configuration

// <i> Configure which nrf_fstorage backend is used by FDS to write to flash.
//==========================================================
// <o> FDS_BACKEND  - FDS flash backend.
 

// <i> NRF_FSTORAGE_SD uses the nrf_fstorage_sd backend implementation using the SoftDevice API. Use this if you have a SoftDevice present.
// <i> NRF_FSTORAGE_NVMC uses the nrf_fstorage_nvmc implementation. Use this setting if you don't use the SoftDevice.
// <1=> NRF_FSTORAGE_NVMC 
// <2=> NRF_FSTORAGE_SD 

#ifndef FDS_BACKEND
#define FDS_BACKEND 2
#endif

// </h> 
//==========================================================

// <h> Queue - Queue settings

//==========================================================
// <o> FDS_OP_QUEUE_SIZE - Size of the internal queue. 
// <i> Increase this value if you frequently get synchronous FDS_ERR_NO_SPACE_IN_QUEUES errors.

#ifndef FDS_OP_QUEUE_SIZE
#define FDS_OP_QUEUE_SIZE 4
#endif

// </h> 
//==========================================================

// <h> CRC - CRC functionality

//==========================================================
// <e> FDS_CRC_CHECK_ON_READ - Enable CRC checks.

// <i> Save a record's CRC when it is written to flash and check it when the record is opened.
// <i> Records with an incorrect CRC can still be 'seen' by the user using FDS functions, but they cannot be opened.
// <i> Additionally, they will not be garbage collected until they are deleted.
//==========================================================
#ifndef FDS_CRC_CHECK_ON_READ
#define FDS_CRC_CHECK_ON_READ 0
#endif
// <o> FDS_CRC_CHECK_ON_WRITE  - Perform a CRC check on newly written records.
 

// <i> Perform a CRC check on newly written records.
// <i> This setting can be used to make sure that the record data was not altered while being written to flash.
// <1=> Enabled 
// <0=> Disabled 

#ifndef FDS_CRC_CHECK_ON_WRITE
#define FDS_CRC_CHECK_ON_WRITE 0
#endif

// </e>

// </h> 
//==========================================================

// <h> Users - Number of users

//==========================================================
// <o> FDS_MAX_USERS - Maximum number of callbacks that can be registered. 
#ifndef FDS_MAX_USERS
#define FDS_MAX_USERS 4
#endif

FSTORAGE defines -

// <e> NRF_FSTORAGE_ENABLED - nrf_fstorage - Flash abstraction library
//==========================================================
#ifndef NRF_FSTORAGE_ENABLED
#define NRF_FSTORAGE_ENABLED 1
#endif
// <h> nrf_fstorage - Common settings

// <i> Common settings to all fstorage implementations
//==========================================================
// <q> NRF_FSTORAGE_PARAM_CHECK_DISABLED  - Disable user input validation
 

// <i> If selected, use ASSERT to validate user input.
// <i> This effectively removes user input validation in production code.
// <i> Recommended setting: OFF, only enable this setting if size is a major concern.

#ifndef NRF_FSTORAGE_PARAM_CHECK_DISABLED
#define NRF_FSTORAGE_PARAM_CHECK_DISABLED 0
#endif

// </h> 
//==========================================================

// <h> nrf_fstorage_sd - Implementation using the SoftDevice

// <i> Configuration options for the fstorage implementation using the SoftDevice
//==========================================================
// <o> NRF_FSTORAGE_SD_QUEUE_SIZE - Size of the internal queue of operations 
// <i> Increase this value if API calls frequently return the error @ref NRF_ERROR_NO_MEM.

#ifndef NRF_FSTORAGE_SD_QUEUE_SIZE
#define NRF_FSTORAGE_SD_QUEUE_SIZE 4
#endif

// <o> NRF_FSTORAGE_SD_MAX_RETRIES - Maximum number of attempts at executing an operation when the SoftDevice is busy 
// <i> Increase this value if events frequently return the @ref NRF_ERROR_TIMEOUT error.
// <i> The SoftDevice might fail to schedule flash access due to high BLE activity.

#ifndef NRF_FSTORAGE_SD_MAX_RETRIES
#define NRF_FSTORAGE_SD_MAX_RETRIES 8
#endif

// <o> NRF_FSTORAGE_SD_MAX_WRITE_SIZE - Maximum number of bytes to be written to flash in a single operation 
// <i> This value must be a multiple of four.
// <i> Lowering this value can increase the chances of the SoftDevice being able to execute flash operations in between radio activity.
// <i> This value is bound by the maximum number of bytes that can be written to flash in a single call to @ref sd_flash_write.
// <i> That is 1024 bytes for nRF51 ICs and 4096 bytes for nRF52 ICs.

#ifndef NRF_FSTORAGE_SD_MAX_WRITE_SIZE
#define NRF_FSTORAGE_SD_MAX_WRITE_SIZE 4096
#endif

pm_conn_secure() is not called in main.c

I never use the delete_bonds() function & I also dont use BLE_GAP_CONN_SEC_MODE_SET_ENC_NO_MITM().