esp-nimble-cpp/src/NimBLERemoteDescriptor.cpp

/*
 * NimBLERemoteDescriptor.cpp
 *
 *  Created: on Jan 27 2020
 *      Author H2zero
 *
 * Originally:
 *
 * BLERemoteDescriptor.cpp
 *
 *  Created on: Jul 8, 2017
 *      Author: kolban
 */

#include "nimconfig.h"
#if defined(CONFIG_BT_ENABLED) && defined(CONFIG_BT_NIMBLE_ROLE_CENTRAL)

#include "NimBLERemoteDescriptor.h"
#include "NimBLEUtils.h"
#include "NimBLELog.h"

#include <climits>

static const char* LOG_TAG = "NimBLERemoteDescriptor";

/**
 * @brief Remote descriptor constructor.
 * @param [in] pRemoteCharacteristic A pointer to the Characteristic that this belongs to.
 * @param [in] dsc A pointer to the struct that contains the descriptor information.
 */
NimBLERemoteDescriptor::NimBLERemoteDescriptor(NimBLERemoteCharacteristic* pRemoteCharacteristic,
                                               const struct ble_gatt_dsc *dsc)
{
    NIMBLE_LOGD(LOG_TAG, ">> NimBLERemoteDescriptor()");
    switch (dsc->uuid.u.type) {
        case BLE_UUID_TYPE_16:
            m_uuid = NimBLEUUID(dsc->uuid.u16.value);
            break;
        case BLE_UUID_TYPE_32:
            m_uuid = NimBLEUUID(dsc->uuid.u32.value);
            break;
        case BLE_UUID_TYPE_128:
            m_uuid = NimBLEUUID(const_cast<ble_uuid128_t*>(&dsc->uuid.u128));
            break;
        default:
            break;
    }

    m_handle                = dsc->handle;
    m_pRemoteCharacteristic = pRemoteCharacteristic;

    NIMBLE_LOGD(LOG_TAG, "<< NimBLERemoteDescriptor(): %s", m_uuid.toString().c_str());
}


/**
 * @brief Retrieve the handle associated with this remote descriptor.
 * @return The handle associated with this remote descriptor.
 */
uint16_t NimBLERemoteDescriptor::getHandle() {
    return m_handle;
} // getHandle


/**
 * @brief Get the characteristic that owns this descriptor.
 * @return The characteristic that owns this descriptor.
 */
NimBLERemoteCharacteristic* NimBLERemoteDescriptor::getRemoteCharacteristic() {
    return m_pRemoteCharacteristic;
} // getRemoteCharacteristic


/**
 * @brief Retrieve the UUID associated this remote descriptor.
 * @return The UUID associated this remote descriptor.
 */
NimBLEUUID NimBLERemoteDescriptor::getUUID() {
    return m_uuid;
} // getUUID


/**
 * @brief Read the value of the remote descriptor.
 * @return The value of the remote descriptor.
 */
NimBLEAttValue NimBLERemoteDescriptor::readValue() {
    NIMBLE_LOGD(LOG_TAG, ">> Descriptor readValue: %s", toString().c_str());

    NimBLEClient* pClient = getRemoteCharacteristic()->getRemoteService()->getClient();
    NimBLEAttValue value;

    if (!pClient->isConnected()) {
        NIMBLE_LOGE(LOG_TAG, "Disconnected");
        return value;
    }

    int rc = 0;
    int retryCount = 1;
    TaskHandle_t cur_task = xTaskGetCurrentTaskHandle();
    ble_task_data_t taskData = {this, cur_task, 0, &value};

    do {
        rc = ble_gattc_read_long(pClient->getConnId(), m_handle, 0,
                                 NimBLERemoteDescriptor::onReadCB,
                                 &taskData);
        if (rc != 0) {
            NIMBLE_LOGE(LOG_TAG, "Error: Failed to read descriptor; rc=%d, %s",
                                  rc, NimBLEUtils::returnCodeToString(rc));
            return value;
        }

#ifdef ulTaskNotifyValueClear
        // Clear the task notification value to ensure we block
        ulTaskNotifyValueClear(cur_task, ULONG_MAX);
#endif
        ulTaskNotifyTake(pdTRUE, portMAX_DELAY);
        rc = taskData.rc;

        switch(rc){
            case 0:
            case BLE_HS_EDONE:
                rc = 0;
                break;
            // Descriptor is not long-readable, return with what we have.
            case BLE_HS_ATT_ERR(BLE_ATT_ERR_ATTR_NOT_LONG):
                NIMBLE_LOGI(LOG_TAG, "Attribute not long");
                rc = 0;
                break;
            case BLE_HS_ATT_ERR(BLE_ATT_ERR_INSUFFICIENT_AUTHEN):
            case BLE_HS_ATT_ERR(BLE_ATT_ERR_INSUFFICIENT_AUTHOR):
            case BLE_HS_ATT_ERR(BLE_ATT_ERR_INSUFFICIENT_ENC):
                if (retryCount && pClient->secureConnection())
                    break;
            /* Else falls through. */
            default:
                return value;
        }
    } while(rc != 0 && retryCount--);

    NIMBLE_LOGD(LOG_TAG, "<< Descriptor readValue(): length: %u rc=%d", value.length(), rc);
    return value;
} // readValue


/**
 * @brief Callback for Descriptor read operation.
 * @return success == 0 or error code.
 */
int NimBLERemoteDescriptor::onReadCB(uint16_t conn_handle,
                const struct ble_gatt_error *error,
                struct ble_gatt_attr *attr, void *arg)
{
    (void)attr;
    ble_task_data_t *pTaskData = (ble_task_data_t*)arg;
    NimBLERemoteDescriptor* desc = (NimBLERemoteDescriptor*)pTaskData->pATT;
    uint16_t conn_id = desc->getRemoteCharacteristic()->getRemoteService()->getClient()->getConnId();

    if(conn_id != conn_handle){
        return 0;
    }

    NIMBLE_LOGD(LOG_TAG, "Read complete; status=%d conn_handle=%d", error->status, conn_handle);

    NimBLEAttValue *valBuf = (NimBLEAttValue*)pTaskData->buf;
    int rc = error->status;

    if(rc == 0) {
        if(attr) {
            uint16_t data_len = OS_MBUF_PKTLEN(attr->om);
            if((valBuf->size() + data_len) > BLE_ATT_ATTR_MAX_LEN) {
                rc = BLE_ATT_ERR_INVALID_ATTR_VALUE_LEN;
            } else {
                NIMBLE_LOGD(LOG_TAG, "Got %u bytes", data_len);
                valBuf->append(attr->om->om_data, data_len);
                return 0;
            }
        }
    }

    pTaskData->rc = rc;
    xTaskNotifyGive(pTaskData->task);

    return rc;
}


/**
 * @brief Return a string representation of this Remote Descriptor.
 * @return A string representation of this Remote Descriptor.
 */
std::string NimBLERemoteDescriptor::toString() {
    std::string res = "Descriptor: uuid: " + getUUID().toString();
    char val[6];
    res += ", handle: ";
    snprintf(val, sizeof(val), "%d", getHandle());
    res += val;

    return res;
} // toString


/**
 * @brief Callback for descriptor write operation.
 * @return success == 0 or error code.
 */
int NimBLERemoteDescriptor::onWriteCB(uint16_t conn_handle,
                const struct ble_gatt_error *error,
                struct ble_gatt_attr *attr, void *arg)
{
    ble_task_data_t *pTaskData = (ble_task_data_t*)arg;
    NimBLERemoteDescriptor* descriptor = (NimBLERemoteDescriptor*)pTaskData->pATT;

    if(descriptor->getRemoteCharacteristic()->getRemoteService()->getClient()->getConnId() != conn_handle){
        return 0;
    }

    NIMBLE_LOGI(LOG_TAG, "Write complete; status=%d conn_handle=%d", error->status, conn_handle);

    pTaskData->rc = error->status;
    xTaskNotifyGive(pTaskData->task);

    return 0;
}


/**
 * @brief Write a new value to a remote descriptor from a std::vector<uint8_t>.
 * @param [in] vec A std::vector<uint8_t> value to write to the remote descriptor.
 * @param [in] response Whether we require a response from the write.
 * @return false if not connected or otherwise cannot perform write.
 */
bool NimBLERemoteDescriptor::writeValue(const std::vector<uint8_t>& vec, bool response) {
    return writeValue((uint8_t*)&vec[0], vec.size(), response);
} // writeValue


/**
 * @brief Write a new value to the remote descriptor from a const char*.
 * @param [in] char_s A character string to write to the remote descriptor.
 * @param [in] response Whether we require a response from the write.
 * @return false if not connected or otherwise cannot perform write.
 */
bool NimBLERemoteDescriptor::writeValue(const char* char_s, bool response) {
    return writeValue((uint8_t*)char_s, strlen(char_s), response);
} // writeValue


/**
 * @brief Write a new value to a remote descriptor.
 * @param [in] data The data to send to the remote descriptor.
 * @param [in] length The length of the data to send.
 * @param [in] response True if we expect a write response.
 * @return false if not connected or otherwise cannot perform write.
 */
bool NimBLERemoteDescriptor::writeValue(const uint8_t* data, size_t length, bool response) {

    NIMBLE_LOGD(LOG_TAG, ">> Descriptor writeValue: %s", toString().c_str());

    NimBLEClient* pClient = getRemoteCharacteristic()->getRemoteService()->getClient();

    // Check to see that we are connected.
    if (!pClient->isConnected()) {
        NIMBLE_LOGE(LOG_TAG, "Disconnected");
        return false;
    }

    int rc = 0;
    int retryCount = 1;
    uint16_t mtu = ble_att_mtu(pClient->getConnId()) - 3;

    // Check if the data length is longer than we can write in 1 connection event.
    // If so we must do a long write which requires a response.
    if(length <= mtu && !response) {
        rc =  ble_gattc_write_no_rsp_flat(pClient->getConnId(), m_handle, data, length);
        return (rc == 0);
    }

    TaskHandle_t cur_task = xTaskGetCurrentTaskHandle();
    ble_task_data_t taskData = {this, cur_task, 0, nullptr};

    do {
        if(length > mtu) {
            NIMBLE_LOGI(LOG_TAG,"long write %d bytes", length);
            os_mbuf *om = ble_hs_mbuf_from_flat(data, length);
            rc = ble_gattc_write_long(pClient->getConnId(), m_handle, 0, om,
                                      NimBLERemoteDescriptor::onWriteCB,
                                      &taskData);
        } else {
            rc = ble_gattc_write_flat(pClient->getConnId(), m_handle,
                                      data, length,
                                      NimBLERemoteDescriptor::onWriteCB,
                                      &taskData);
        }

        if (rc != 0) {
            NIMBLE_LOGE(LOG_TAG, "Error: Failed to write descriptor; rc=%d", rc);
            return false;
        }

#ifdef ulTaskNotifyValueClear
        // Clear the task notification value to ensure we block
        ulTaskNotifyValueClear(cur_task, ULONG_MAX);
#endif
        ulTaskNotifyTake(pdTRUE, portMAX_DELAY);
        rc = taskData.rc;

        switch(rc) {
            case 0:
            case BLE_HS_EDONE:
                rc = 0;
                break;
            case BLE_HS_ATT_ERR(BLE_ATT_ERR_ATTR_NOT_LONG):
                NIMBLE_LOGE(LOG_TAG, "Long write not supported by peer; Truncating length to %d", mtu);
                retryCount++;
                length = mtu;
                break;

            case BLE_HS_ATT_ERR(BLE_ATT_ERR_INSUFFICIENT_AUTHEN):
            case BLE_HS_ATT_ERR(BLE_ATT_ERR_INSUFFICIENT_AUTHOR):
            case BLE_HS_ATT_ERR(BLE_ATT_ERR_INSUFFICIENT_ENC):
                if (retryCount && pClient->secureConnection())
                    break;
            /* Else falls through. */
            default:
                return false;
        }
    } while(rc != 0 && retryCount--);

    NIMBLE_LOGD(LOG_TAG, "<< Descriptor writeValue, rc: %d",rc);
    return (rc == 0);
} // writeValue


#endif /* CONFIG_BT_ENABLED && CONFIG_BT_NIMBLE_ROLE_CENTRAL */