/** * Copyright (c) 2016 - 2020, Nordic Semiconductor ASA * * All rights reserved. * * Redistribution and use in source and binary forms, with or without modification, * are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, this * list of conditions and the following disclaimer. * * 2. Redistributions in binary form, except as embedded into a Nordic * Semiconductor ASA integrated circuit in a product or a software update for * such product, must reproduce the above copyright notice, this list of * conditions and the following disclaimer in the documentation and/or other * materials provided with the distribution. * * 3. Neither the name of Nordic Semiconductor ASA nor the names of its * contributors may be used to endorse or promote products derived from this * software without specific prior written permission. * * 4. This software, with or without modification, must only be used with a * Nordic Semiconductor ASA integrated circuit. * * 5. Any software provided in binary form under this license must not be reverse * engineered, decompiled, modified and/or disassembled. * * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * */ #include "sdk_common.h" #if NRF_MODULE_ENABLED(NRF_BLE_GATT) #include "nrf_ble_gatt.h" #define NRF_LOG_MODULE_NAME nrf_ble_gatt #include "nrf_log.h" NRF_LOG_MODULE_REGISTER(); #include "nrf_strerror.h" #define BLE_GAP_DATA_LENGTH_DEFAULT 27 //!< The stack's default data length. #define BLE_GAP_DATA_LENGTH_MAX 251 //!< Maximum data length. STATIC_ASSERT(NRF_SDH_BLE_GAP_DATA_LENGTH < 252); /**@brief Initialize a link's parameters to defaults. */ static void link_init(nrf_ble_gatt_link_t * p_link) { p_link->att_mtu_desired = NRF_SDH_BLE_GATT_MAX_MTU_SIZE; p_link->att_mtu_effective = BLE_GATT_ATT_MTU_DEFAULT; p_link->att_mtu_exchange_pending = false; p_link->att_mtu_exchange_requested = false; #if !defined (S112) && !defined(S312) && !defined (S122) p_link->data_length_desired = NRF_SDH_BLE_GAP_DATA_LENGTH; p_link->data_length_effective = BLE_GAP_DATA_LENGTH_DEFAULT; #endif // !defined (S112) && !defined(S312) && !defined (S122) } /**@brief Start a data length update request procedure on a given connection. */ #if !defined (S112) && !defined(S312) && !defined(S122) static ret_code_t data_length_update(uint16_t conn_handle, uint16_t data_length) { NRF_LOG_DEBUG("Updating data length to %u on connection 0x%x.", data_length, conn_handle); ble_gap_data_length_params_t const dlp = { .max_rx_octets = data_length, .max_tx_octets = data_length, .max_rx_time_us = BLE_GAP_DATA_LENGTH_AUTO, .max_tx_time_us = BLE_GAP_DATA_LENGTH_AUTO, }; ble_gap_data_length_limitation_t dll = {0}; ret_code_t err_code = sd_ble_gap_data_length_update(conn_handle, &dlp, &dll); if (err_code != NRF_SUCCESS) { NRF_LOG_ERROR("sd_ble_gap_data_length_update() (request) on connection 0x%x returned %s.", conn_handle, nrf_strerror_get(err_code)); if ( (dll.tx_payload_limited_octets != 0) || (dll.rx_payload_limited_octets != 0)) { NRF_LOG_ERROR("The requested TX/RX packet length is too long by %u/%u octets.", dll.tx_payload_limited_octets, dll.rx_payload_limited_octets); } if (dll.tx_rx_time_limited_us != 0) { NRF_LOG_ERROR("The requested combination of TX and RX packet lengths " "is too long by %u microseconds.", dll.tx_rx_time_limited_us); } } return err_code; } #endif // !defined (S112) && !defined(S312) && !defined (S122) /**@brief Handle a connected event. * * Begins an ATT MTU exchange procedure, followed by a data length update request as necessary. * * @param[in] p_gatt GATT structure. * @param[in] p_ble_evt Event received from the BLE stack. */ static void on_connected_evt(nrf_ble_gatt_t * p_gatt, ble_evt_t const * p_ble_evt) { ret_code_t err_code; uint16_t conn_handle = p_ble_evt->evt.common_evt.conn_handle; nrf_ble_gatt_link_t * p_link = &p_gatt->links[conn_handle]; // Update the link desired settings to reflect the current global settings. #if !defined (S112) && !defined(S312) && !defined(S122) p_link->data_length_desired = p_gatt->data_length; #endif // !defined (S112) && !defined(S312) && !defined (S122) switch (p_ble_evt->evt.gap_evt.params.connected.role) { #if !defined (S122) case BLE_GAP_ROLE_PERIPH: p_link->att_mtu_desired = p_gatt->att_mtu_desired_periph; break; #endif // !defined (S122) #if !defined (S112) && !defined(S312) && !defined(S113) case BLE_GAP_ROLE_CENTRAL: p_link->att_mtu_desired = p_gatt->att_mtu_desired_central; break; #endif // !defined (S112) && !defined(S312) && !defined(S113) default: // Ignore. break; } // Begin an ATT MTU exchange if necessary. if (p_link->att_mtu_desired > p_link->att_mtu_effective) { NRF_LOG_DEBUG("Requesting to update ATT MTU to %u bytes on connection 0x%x.", p_link->att_mtu_desired, conn_handle); err_code = sd_ble_gattc_exchange_mtu_request(conn_handle, p_link->att_mtu_desired); if (err_code == NRF_SUCCESS) { p_link->att_mtu_exchange_requested = true; } else if (err_code == NRF_ERROR_BUSY) { p_link->att_mtu_exchange_pending = true; NRF_LOG_DEBUG("sd_ble_gattc_exchange_mtu_request()" " on connection 0x%x returned busy, will retry.", conn_handle); } else { NRF_LOG_ERROR("sd_ble_gattc_exchange_mtu_request() returned %s.", nrf_strerror_get(err_code)); } } #if !defined (S112) && !defined(S312) && !defined (S122) // Send a data length update request if necessary. if (p_link->data_length_desired > p_link->data_length_effective) { (void) data_length_update(conn_handle, p_link->data_length_desired); } #endif // !defined (S112) && !defined(S312) && !defined (S122) } static void on_disconnected_evt(nrf_ble_gatt_t * p_gatt, ble_evt_t const * p_ble_evt) { // Reset connection parameters. link_init(&p_gatt->links[p_ble_evt->evt.gap_evt.conn_handle]); } /**@brief Handle a BLE_GATTC_EVT_EXCHANGE_MTU_RSP event. * * @details The effective ATT MTU is set to the lowest between what we requested and the peer's * response. This events concludes the ATT MTU exchange. An event is sent to the user * and a data length update procedure is started if necessary. * * @param[in] p_gatt GATT structure. * @param[in] p_ble_evt Event received from the BLE stack. */ static void on_exchange_mtu_rsp_evt(nrf_ble_gatt_t * p_gatt, ble_evt_t const * p_ble_evt) { uint16_t conn_handle = p_ble_evt->evt.gattc_evt.conn_handle; uint16_t server_rx_mtu = p_ble_evt->evt.gattc_evt.params.exchange_mtu_rsp.server_rx_mtu; nrf_ble_gatt_link_t * p_link = &p_gatt->links[conn_handle]; // Determine the lowest MTU between our own desired MTU and the peer's. // The MTU may not be less than BLE_GATT_ATT_MTU_DEFAULT. p_link->att_mtu_effective = MIN(server_rx_mtu, p_link->att_mtu_desired); p_link->att_mtu_effective = MAX(p_link->att_mtu_effective, BLE_GATT_ATT_MTU_DEFAULT); NRF_LOG_DEBUG("ATT MTU updated to %u bytes on connection 0x%x (response).", p_link->att_mtu_effective, conn_handle); // Trigger an event indicating that the ATT MTU size has changed. // Send an event to the application only if an ATT MTU exchange was requested. if ((p_gatt->evt_handler != NULL) && (p_link->att_mtu_exchange_requested)) { nrf_ble_gatt_evt_t const evt = { .evt_id = NRF_BLE_GATT_EVT_ATT_MTU_UPDATED, .conn_handle = conn_handle, .params.att_mtu_effective = p_link->att_mtu_effective, }; p_gatt->evt_handler(p_gatt, &evt); } p_link->att_mtu_exchange_requested = false; p_link->att_mtu_exchange_pending = false; } /**@brief Handle a BLE_GATTS_EVT_EXCHANGE_MTU_REQUEST event. * * @param[in] p_gatt GATT structure. * @param[in] p_ble_evt Event received from the BLE stack. */ static void on_exchange_mtu_request_evt(nrf_ble_gatt_t * p_gatt, ble_evt_t const * p_ble_evt) { ret_code_t err_code; uint16_t conn_handle = p_ble_evt->evt.gatts_evt.conn_handle; uint16_t client_mtu = p_ble_evt->evt.gatts_evt.params.exchange_mtu_request.client_rx_mtu; nrf_ble_gatt_link_t * p_link = &p_gatt->links[conn_handle]; NRF_LOG_DEBUG("Peer on connection 0x%x requested an ATT MTU of %u bytes.", conn_handle, client_mtu); client_mtu = MAX(client_mtu, BLE_GATT_ATT_MTU_DEFAULT); p_link->att_mtu_effective = MIN(client_mtu, p_link->att_mtu_desired); p_link->att_mtu_exchange_pending = false; NRF_LOG_DEBUG("Updating ATT MTU to %u bytes (desired: %u) on connection 0x%x.", p_link->att_mtu_effective, p_link->att_mtu_desired, conn_handle); err_code = sd_ble_gatts_exchange_mtu_reply(conn_handle, p_link->att_mtu_desired); if (err_code != NRF_SUCCESS) { NRF_LOG_ERROR("sd_ble_gatts_exchange_mtu_reply() returned %s.", nrf_strerror_get(err_code)); } // If an ATT_MTU exchange was requested to the peer, defer sending // the data length update request and the event to the application until // the response for that request is received. if (p_link->att_mtu_exchange_requested) { return; } // The ATT MTU exchange has finished. Send an event to the application. if (p_gatt->evt_handler != NULL) { nrf_ble_gatt_evt_t const evt = { .evt_id = NRF_BLE_GATT_EVT_ATT_MTU_UPDATED, .conn_handle = conn_handle, .params.att_mtu_effective = p_link->att_mtu_effective, }; p_gatt->evt_handler(p_gatt, &evt); } } /**@brief Handle a BLE_GAP_EVT_DATA_LENGTH_UPDATE event. * * @details Update the connection data length and send an event to the user. * * @param[in] p_gatt GATT structure. * @param[in] p_ble_evt Event received from the BLE stack. */ #if !defined (S112) && !defined(S312) && !defined (S122) static void on_data_length_update_evt(nrf_ble_gatt_t * p_gatt, ble_evt_t const * p_ble_evt) { ble_gap_evt_t const gap_evt = p_ble_evt->evt.gap_evt; uint16_t const conn_handle = gap_evt.conn_handle; // Update the connection data length. // The SoftDevice only supports symmetric RX/TX data length settings. p_gatt->links[conn_handle].data_length_effective = gap_evt.params.data_length_update.effective_params.max_tx_octets; NRF_LOG_DEBUG("Data length updated to %u on connection 0x%0x.", p_gatt->links[conn_handle].data_length_effective, conn_handle); NRF_LOG_DEBUG("max_rx_octets: %u", gap_evt.params.data_length_update.effective_params.max_rx_octets); NRF_LOG_DEBUG("max_tx_octets: %u", gap_evt.params.data_length_update.effective_params.max_tx_octets); NRF_LOG_DEBUG("max_rx_time: %u", gap_evt.params.data_length_update.effective_params.max_rx_time_us); NRF_LOG_DEBUG("max_tx_time: %u", gap_evt.params.data_length_update.effective_params.max_tx_time_us); if (p_gatt->evt_handler != NULL) { nrf_ble_gatt_evt_t const evt = { .evt_id = NRF_BLE_GATT_EVT_DATA_LENGTH_UPDATED, .conn_handle = conn_handle, .params.data_length = p_gatt->links[conn_handle].data_length_effective, }; p_gatt->evt_handler(p_gatt, &evt); } } /**@brief Handle a BLE_GAP_EVT_DATA_LENGTH_UPDATE_REQUEST event. * *@details Reply with a sd_ble_gap_data_length_update() call, using the minimum between the * link's preferred data length, and what requested by the peer. * The link preferred data length is set to the global preferred data length * upon connection and can be overridden by calling nrf_ble_gatt_data_length_set(). * The default is NRF_SDH_BLE_GAP_DATA_LENGTH. * *@note The SoftDevice will not send any BLE_GAP_EVT_DATA_LENGTH_UPDATE events on this side. * Therefore, the connection data length is updated immediately and an event is sent * to the user. * * @param[in] p_gatt GATT structure. * @param[in] p_ble_evt Event received from the BLE stack. */ static void on_data_length_update_request_evt(nrf_ble_gatt_t * p_gatt, ble_evt_t const * p_ble_evt) { ble_gap_evt_t const * p_gap_evt = &p_ble_evt->evt.gap_evt; nrf_ble_gatt_link_t * p_link = &p_gatt->links[p_gap_evt->conn_handle]; // The SoftDevice only supports symmetric RX/TX data length settings. uint8_t const data_length_requested = p_gap_evt->params.data_length_update_request.peer_params.max_tx_octets; NRF_LOG_DEBUG("Peer on connection 0x%x requested a data length of %u bytes.", p_gap_evt->conn_handle, data_length_requested); uint8_t const data_length_effective = MIN(p_link->data_length_desired, data_length_requested); (void) data_length_update(p_gap_evt->conn_handle, data_length_effective); } #endif // !defined (S112) && !defined(S312) && !defined (S122) ret_code_t nrf_ble_gatt_init(nrf_ble_gatt_t * p_gatt, nrf_ble_gatt_evt_handler_t evt_handler) { VERIFY_PARAM_NOT_NULL(p_gatt); p_gatt->evt_handler = evt_handler; p_gatt->att_mtu_desired_periph = NRF_SDH_BLE_GATT_MAX_MTU_SIZE; p_gatt->att_mtu_desired_central = NRF_SDH_BLE_GATT_MAX_MTU_SIZE; p_gatt->data_length = NRF_SDH_BLE_GAP_DATA_LENGTH; for (uint32_t i = 0; i < NRF_BLE_GATT_LINK_COUNT; i++) { link_init(&p_gatt->links[i]); } return NRF_SUCCESS; } ret_code_t nrf_ble_gatt_att_mtu_periph_set(nrf_ble_gatt_t * p_gatt, uint16_t desired_mtu) { VERIFY_PARAM_NOT_NULL(p_gatt); if ((desired_mtu < BLE_GATT_ATT_MTU_DEFAULT) || (desired_mtu > NRF_SDH_BLE_GATT_MAX_MTU_SIZE)) { return NRF_ERROR_INVALID_PARAM; } p_gatt->att_mtu_desired_periph = desired_mtu; return NRF_SUCCESS; } ret_code_t nrf_ble_gatt_att_mtu_central_set(nrf_ble_gatt_t * p_gatt, uint16_t desired_mtu) { VERIFY_PARAM_NOT_NULL(p_gatt); if ((desired_mtu < BLE_GATT_ATT_MTU_DEFAULT) || (desired_mtu > NRF_SDH_BLE_GATT_MAX_MTU_SIZE)) { return NRF_ERROR_INVALID_PARAM; } p_gatt->att_mtu_desired_central = desired_mtu; return NRF_SUCCESS; } uint16_t nrf_ble_gatt_eff_mtu_get(nrf_ble_gatt_t const * p_gatt, uint16_t conn_handle) { if ((p_gatt == NULL) || (conn_handle >= NRF_BLE_GATT_LINK_COUNT)) { return 0; } return p_gatt->links[conn_handle].att_mtu_effective; } #if !defined (S112) && !defined(S312) && !defined (S122) ret_code_t nrf_ble_gatt_data_length_set(nrf_ble_gatt_t * p_gatt, uint16_t conn_handle, uint8_t data_length) { if (p_gatt == NULL) { return NRF_ERROR_NULL; } // Check early to avoid requesting an invalid data length for upcoming connections. if ( (data_length > BLE_GAP_DATA_LENGTH_MAX) || (data_length < BLE_GAP_DATA_LENGTH_DEFAULT)) { return NRF_ERROR_INVALID_PARAM; } if (conn_handle == BLE_CONN_HANDLE_INVALID) { // Save value and request upon connection. p_gatt->data_length = data_length; return NRF_SUCCESS; } if (conn_handle >= NRF_BLE_GATT_LINK_COUNT) { return NRF_ERROR_INVALID_PARAM; } // Request data length on existing link. p_gatt->links[conn_handle].data_length_desired = data_length; return data_length_update(conn_handle, data_length); } ret_code_t nrf_ble_gatt_data_length_get(nrf_ble_gatt_t const * p_gatt, uint16_t conn_handle, uint8_t * p_data_length) { if ((p_gatt == NULL) || (p_data_length == NULL)) { return NRF_ERROR_NULL; } if (conn_handle == BLE_CONN_HANDLE_INVALID) { *p_data_length = p_gatt->data_length; return NRF_SUCCESS; } if (conn_handle >= NRF_BLE_GATT_LINK_COUNT) { return NRF_ERROR_INVALID_PARAM; } *p_data_length = p_gatt->links[conn_handle].data_length_effective; return NRF_SUCCESS; } #endif // !defined (S112) && !defined(S312) && !defined(S122) void nrf_ble_gatt_on_ble_evt(ble_evt_t const * p_ble_evt, void * p_context) { nrf_ble_gatt_t * p_gatt = (nrf_ble_gatt_t *)p_context; uint16_t conn_handle = p_ble_evt->evt.common_evt.conn_handle; if (conn_handle >= NRF_BLE_GATT_LINK_COUNT) { return; } switch (p_ble_evt->header.evt_id) { case BLE_GAP_EVT_CONNECTED: on_connected_evt(p_gatt, p_ble_evt); break; case BLE_GAP_EVT_DISCONNECTED: on_disconnected_evt(p_gatt, p_ble_evt); break; case BLE_GATTC_EVT_EXCHANGE_MTU_RSP: on_exchange_mtu_rsp_evt(p_gatt, p_ble_evt); break; case BLE_GATTS_EVT_EXCHANGE_MTU_REQUEST: on_exchange_mtu_request_evt(p_gatt, p_ble_evt); break; #if !defined (S112) && !defined(S312) && !defined (S122) case BLE_GAP_EVT_DATA_LENGTH_UPDATE: on_data_length_update_evt(p_gatt, p_ble_evt); break; case BLE_GAP_EVT_DATA_LENGTH_UPDATE_REQUEST: on_data_length_update_request_evt(p_gatt, p_ble_evt); break; #endif // !defined (S112) && !defined(S312) && !defined (S122) default: break; } if (p_gatt->links[conn_handle].att_mtu_exchange_pending) { ret_code_t err_code; err_code = sd_ble_gattc_exchange_mtu_request(conn_handle, p_gatt->links[conn_handle].att_mtu_desired); if (err_code == NRF_SUCCESS) { p_gatt->links[conn_handle].att_mtu_exchange_pending = false; p_gatt->links[conn_handle].att_mtu_exchange_requested = true; NRF_LOG_DEBUG("Requesting to update ATT MTU to %u bytes on connection 0x%x (retry).", p_gatt->links[conn_handle].att_mtu_desired, conn_handle); } else if (err_code != NRF_ERROR_BUSY) { NRF_LOG_ERROR("sd_ble_gattc_exchange_mtu_request() returned %s.", nrf_strerror_get(err_code)); } } } #endif //NRF_BLE_GATT_ENABLED