/* * Copyright (C) 2014 BlueKitchen GmbH * * 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 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 the copyright holders nor the names of * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * 4. Any redistribution, use, or modification is done solely for * personal benefit and not for any commercial purpose or for * monetary gain. * * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BLUEKITCHEN * GMBH 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. * * Please inquire about commercial licensing options at * contact@bluekitchen-gmbh.com * */ #define BTSTACK_FILE__ "att_server.c" // // ATT Server Globals // #include #include #include #include "btstack_config.h" #include "ble/att_dispatch.h" #include "ble/att_db.h" #include "ble/att_server.h" #include "ble/core.h" #include "ble/le_device_db.h" #include "ble/sm.h" #include "btstack_debug.h" #include "btstack_event.h" #include "btstack_memory.h" #include "btstack_run_loop.h" #include "gap.h" #include "hci.h" #include "hci_dump.h" #include "l2cap.h" #include "btstack_tlv.h" #ifdef ENABLE_LE_SIGNED_WRITE #include "ble/sm.h" #include "bluetooth_psm.h" #endif #ifdef ENABLE_TESTING_SUPPORT #include #endif #ifndef NVN_NUM_GATT_SERVER_CCC #define NVN_NUM_GATT_SERVER_CCC 20 #endif #define ATT_SERVICE_FLAGS_DELAYED_RESPONSE (1<<0u) static void att_run_for_context(att_server_t * att_server, att_connection_t * att_connection); static att_write_callback_t att_server_write_callback_for_handle(uint16_t handle); static btstack_packet_handler_t att_server_packet_handler_for_handle(uint16_t handle); static void att_server_handle_can_send_now(void); static void att_server_persistent_ccc_restore(att_server_t * att_server, att_connection_t * att_connection); static void att_server_persistent_ccc_clear(att_server_t * att_server); static void att_server_handle_att_pdu(att_server_t * att_server, att_connection_t * att_connection, uint8_t * packet, uint16_t size); typedef enum { ATT_SERVER_RUN_PHASE_1_REQUESTS = 0, ATT_SERVER_RUN_PHASE_2_INDICATIONS, ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS, } att_server_run_phase_t; // typedef struct { uint32_t seq_nr; uint16_t att_handle; uint8_t value; uint8_t device_index; } persistent_ccc_entry_t; // global static btstack_packet_callback_registration_t hci_event_callback_registration; static btstack_packet_callback_registration_t sm_event_callback_registration; static btstack_packet_handler_t att_client_packet_handler; static btstack_linked_list_t service_handlers; static btstack_context_callback_registration_t att_client_waiting_for_can_send_registration; static att_read_callback_t att_server_client_read_callback; static att_write_callback_t att_server_client_write_callback; // round robin static hci_con_handle_t att_server_last_can_send_now = HCI_CON_HANDLE_INVALID; static uint8_t att_server_flags; #ifdef ENABLE_GATT_OVER_EATT typedef struct { btstack_linked_item_t item; att_server_t att_server; att_connection_t att_connection; uint8_t * receive_buffer; uint8_t * send_buffer; } att_server_eatt_bearer_t; static att_server_eatt_bearer_t * att_server_eatt_bearer_for_con_handle(hci_con_handle_t con_handle); static btstack_linked_list_t att_server_eatt_bearer_pool; static btstack_linked_list_t att_server_eatt_bearer_active; #endif #ifdef ENABLE_LE_SIGNED_WRITE static bool att_server_connections_for_state(att_server_state_t state, att_server_t ** att_server_out, att_connection_t ** att_connection_out){ btstack_linked_list_iterator_t it; hci_connections_get_iterator(&it); while(btstack_linked_list_iterator_has_next(&it)){ hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); if (hci_connection->att_server.state == state) { *att_server_out = &hci_connection->att_server; *att_connection_out = &hci_connection->att_connection; return true; } } #ifdef ENABLE_GATT_OVER_EATT btstack_linked_list_iterator_init(&it, &att_server_eatt_bearer_active); while(btstack_linked_list_iterator_has_next(&it)){ att_server_eatt_bearer_t * eatt_bearer = (att_server_eatt_bearer_t *) btstack_linked_list_iterator_next(&it); if (eatt_bearer->att_server.state == state) { *att_server_out = &eatt_bearer->att_server; *att_connection_out = &eatt_bearer->att_connection; return true; } } #endif return false; } #endif static void att_server_request_can_send_now(att_server_t * att_server, att_connection_t * att_connection ){ switch (att_server->bearer_type){ case ATT_BEARER_UNENHANCED_LE: #ifdef ENABLE_GATT_OVER_CLASSIC case ATT_BEARER_UNENHANCED_CLASSIC: /* fall through */ #endif att_dispatch_server_request_can_send_now_event(att_connection->con_handle); break; #ifdef ENABLE_GATT_OVER_EATT case ATT_BEARER_ENHANCED_LE: l2cap_request_can_send_now_event(att_server->l2cap_cid); break; #endif default: btstack_unreachable(); break; } } static bool att_server_can_send_packet(att_server_t * att_server, att_connection_t * att_connection){ switch (att_server->bearer_type) { case ATT_BEARER_UNENHANCED_LE: #ifdef ENABLE_GATT_OVER_CLASSIC case ATT_BEARER_UNENHANCED_CLASSIC: /* fall through */ #endif return att_dispatch_server_can_send_now(att_connection->con_handle); #ifdef ENABLE_GATT_OVER_EATT case ATT_BEARER_ENHANCED_LE: return l2cap_can_send_packet_now(att_server->l2cap_cid); #endif default: btstack_unreachable(); break; } return false; } static void att_handle_value_indication_notify_client(uint8_t status, uint16_t client_handle, uint16_t attribute_handle){ btstack_packet_handler_t packet_handler = att_server_packet_handler_for_handle(attribute_handle); if (!packet_handler) return; uint8_t event[7]; int pos = 0; event[pos++] = ATT_EVENT_HANDLE_VALUE_INDICATION_COMPLETE; event[pos++] = sizeof(event) - 2u; event[pos++] = status; little_endian_store_16(event, pos, client_handle); pos += 2; little_endian_store_16(event, pos, attribute_handle); (*packet_handler)(HCI_EVENT_PACKET, 0, &event[0], sizeof(event)); } static void att_emit_event_to_all(const uint8_t * event, uint16_t size){ // dispatch to app level handler if (att_client_packet_handler != NULL){ (*att_client_packet_handler)(HCI_EVENT_PACKET, 0, (uint8_t*) event, size); } // dispatch to service handlers btstack_linked_list_iterator_t it; btstack_linked_list_iterator_init(&it, &service_handlers); while (btstack_linked_list_iterator_has_next(&it)){ att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); if (!handler->packet_handler) continue; (*handler->packet_handler)(HCI_EVENT_PACKET, 0, (uint8_t*) event, size); } } static void att_emit_mtu_event(hci_con_handle_t con_handle, uint16_t mtu){ uint8_t event[6]; int pos = 0; event[pos++] = ATT_EVENT_MTU_EXCHANGE_COMPLETE; event[pos++] = sizeof(event) - 2u; little_endian_store_16(event, pos, con_handle); pos += 2; little_endian_store_16(event, pos, mtu); // also dispatch to GATT Clients att_dispatch_server_mtu_exchanged(con_handle, mtu); // dispatch to app level handler and service handlers att_emit_event_to_all(&event[0], sizeof(event)); } static void att_emit_can_send_now_event(void * context){ UNUSED(context); if (!att_client_packet_handler) return; uint8_t event[] = { ATT_EVENT_CAN_SEND_NOW, 0}; (*att_client_packet_handler)(HCI_EVENT_PACKET, 0, &event[0], sizeof(event)); } static void att_emit_connected_event(att_server_t * att_server, att_connection_t * att_connection){ uint8_t event[11]; int pos = 0; event[pos++] = ATT_EVENT_CONNECTED; event[pos++] = sizeof(event) - 2u; event[pos++] = att_server->peer_addr_type; reverse_bd_addr(att_server->peer_address, &event[pos]); pos += 6; little_endian_store_16(event, pos, att_connection->con_handle); pos += 2; // dispatch to app level handler and service handlers att_emit_event_to_all(&event[0], sizeof(event)); } static void att_emit_disconnected_event(uint16_t con_handle){ uint8_t event[4]; int pos = 0; event[pos++] = ATT_EVENT_DISCONNECTED; event[pos++] = sizeof(event) - 2u; little_endian_store_16(event, pos, con_handle); pos += 2; // dispatch to app level handler and service handlers att_emit_event_to_all(&event[0], sizeof(event)); } static void att_handle_value_indication_timeout(btstack_timer_source_t *ts){ void * context = btstack_run_loop_get_timer_context(ts); hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) context; hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); if (!hci_connection) return; // @note: after a transaction timeout, no more requests shall be sent over this ATT Bearer // (that's why we don't reset the value_indication_handle) att_server_t * att_server = &hci_connection->att_server; uint16_t att_handle = att_server->value_indication_handle; att_connection_t * att_connection = &hci_connection->att_connection; att_handle_value_indication_notify_client((uint8_t)ATT_HANDLE_VALUE_INDICATION_TIMEOUT, att_connection->con_handle, att_handle); } static void att_server_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ UNUSED(channel); // ok: there is no channel UNUSED(size); // ok: handling own l2cap events att_server_t * att_server; att_connection_t * att_connection; hci_con_handle_t con_handle; hci_connection_t * hci_connection; switch (packet_type) { case HCI_EVENT_PACKET: switch (hci_event_packet_get_type(packet)) { case HCI_EVENT_META_GAP: switch (hci_event_gap_meta_get_subevent_code(packet)) { case GAP_SUBEVENT_LE_CONNECTION_COMPLETE: con_handle = gap_subevent_le_connection_complete_get_connection_handle(packet); hci_connection = hci_connection_for_handle(con_handle); if (!hci_connection) break; att_server = &hci_connection->att_server; // store connection info att_server->peer_addr_type = gap_subevent_le_connection_complete_get_peer_address_type(packet); gap_subevent_le_connection_complete_get_peer_address(packet, att_server->peer_address); att_connection = &hci_connection->att_connection; att_connection->con_handle = con_handle; // reset connection properties att_server->state = ATT_SERVER_IDLE; att_server->bearer_type = ATT_BEARER_UNENHANCED_LE; att_connection->mtu = ATT_DEFAULT_MTU; att_connection->max_mtu = l2cap_max_le_mtu(); if (att_connection->max_mtu > ATT_REQUEST_BUFFER_SIZE){ att_connection->max_mtu = ATT_REQUEST_BUFFER_SIZE; } att_connection->encryption_key_size = 0u; att_connection->authenticated = 0u; att_connection->authorized = 0u; // workaround: identity resolving can already be complete, at least store result att_server->ir_le_device_db_index = sm_le_device_index(con_handle); att_server->ir_lookup_active = false; att_server->pairing_active = false; // notify all - new att_emit_connected_event(att_server, att_connection); break; default: break; } break; case HCI_EVENT_LE_META: switch (hci_event_le_meta_get_subevent_code(packet)) { case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: // forward LE Connection Complete event to keep backward compatibility // deprecated: please register hci handler with hci_add_event_handler or handle ATT_EVENT_CONNECTED att_emit_event_to_all(packet, size); break; default: break; } break; case HCI_EVENT_ENCRYPTION_CHANGE: case HCI_EVENT_ENCRYPTION_CHANGE_V2: case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: // check handle con_handle = little_endian_read_16(packet, 3); hci_connection = hci_connection_for_handle(con_handle); if (!hci_connection) break; if (gap_get_connection_type(con_handle) != GAP_CONNECTION_LE) break; // update security params att_server = &hci_connection->att_server; att_connection = &hci_connection->att_connection; att_connection->encryption_key_size = gap_encryption_key_size(con_handle); att_connection->authenticated = gap_authenticated(con_handle) ? 1 : 0; att_connection->secure_connection = gap_secure_connection(con_handle) ? 1 : 0; log_info("encrypted key size %u, authenticated %u, secure connection %u", att_connection->encryption_key_size, att_connection->authenticated, att_connection->secure_connection); if (hci_event_packet_get_type(packet) == HCI_EVENT_ENCRYPTION_CHANGE){ // restore CCC values when encrypted for LE Connections if (hci_event_encryption_change_get_encryption_enabled(packet) != 0){ att_server_persistent_ccc_restore(att_server, att_connection); } } att_run_for_context(att_server, att_connection); break; case HCI_EVENT_DISCONNECTION_COMPLETE: // check handle con_handle = hci_event_disconnection_complete_get_connection_handle(packet); hci_connection = hci_connection_for_handle(con_handle); if (!hci_connection) break; att_server = &hci_connection->att_server; att_connection = &hci_connection->att_connection; att_clear_transaction_queue(att_connection); att_connection->con_handle = 0; att_server->pairing_active = false; att_server->state = ATT_SERVER_IDLE; if (att_server->value_indication_handle != 0u){ btstack_run_loop_remove_timer(&att_server->value_indication_timer); uint16_t att_handle = att_server->value_indication_handle; att_server->value_indication_handle = 0u; // reset error state att_handle_value_indication_notify_client((uint8_t)ATT_HANDLE_VALUE_INDICATION_DISCONNECT, att_connection->con_handle, att_handle); } // notify all - new att_emit_disconnected_event(con_handle); // notify all - old att_emit_event_to_all(packet, size); break; // Identity Resolving case SM_EVENT_IDENTITY_RESOLVING_STARTED: con_handle = sm_event_identity_resolving_started_get_handle(packet); hci_connection = hci_connection_for_handle(con_handle); if (!hci_connection) break; att_server = &hci_connection->att_server; log_info("SM_EVENT_IDENTITY_RESOLVING_STARTED"); att_server->ir_lookup_active = true; break; case SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED: con_handle = sm_event_identity_created_get_handle(packet); hci_connection = hci_connection_for_handle(con_handle); if (!hci_connection) return; att_connection = &hci_connection->att_connection; att_server = &hci_connection->att_server; att_server->ir_lookup_active = false; att_server->ir_le_device_db_index = sm_event_identity_resolving_succeeded_get_index(packet); log_info("SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED"); att_run_for_context(att_server, att_connection); break; case SM_EVENT_IDENTITY_RESOLVING_FAILED: con_handle = sm_event_identity_resolving_failed_get_handle(packet); hci_connection = hci_connection_for_handle(con_handle); if (!hci_connection) break; att_connection = &hci_connection->att_connection; att_server = &hci_connection->att_server; log_info("SM_EVENT_IDENTITY_RESOLVING_FAILED"); att_server->ir_lookup_active = false; att_server->ir_le_device_db_index = -1; att_run_for_context(att_server, att_connection); break; // Pairing started - delete stored CCC values // - assumes pairing indicates either new device or re-pairing, in both cases there should be no stored CCC values // - assumes that all events have the con handle as the first field case SM_EVENT_JUST_WORKS_REQUEST: case SM_EVENT_PASSKEY_DISPLAY_NUMBER: case SM_EVENT_PASSKEY_INPUT_NUMBER: case SM_EVENT_NUMERIC_COMPARISON_REQUEST: con_handle = sm_event_just_works_request_get_handle(packet); hci_connection = hci_connection_for_handle(con_handle); if (!hci_connection) break; att_server = &hci_connection->att_server; log_info("SM Pairing started"); att_server->pairing_active = true; if (att_server->ir_le_device_db_index < 0) break; att_server_persistent_ccc_clear(att_server); // index not valid anymore att_server->ir_le_device_db_index = -1; break; // Bonding completed case SM_EVENT_IDENTITY_CREATED: con_handle = sm_event_identity_created_get_handle(packet); hci_connection = hci_connection_for_handle(con_handle); if (!hci_connection) return; att_connection = &hci_connection->att_connection; att_server = &hci_connection->att_server; att_server->pairing_active = false; att_server->ir_le_device_db_index = sm_event_identity_created_get_index(packet); att_run_for_context(att_server, att_connection); break; // Pairing complete (with/without bonding=storing of pairing information) case SM_EVENT_PAIRING_COMPLETE: con_handle = sm_event_pairing_complete_get_handle(packet); hci_connection = hci_connection_for_handle(con_handle); if (!hci_connection) return; att_connection = &hci_connection->att_connection; att_server = &hci_connection->att_server; att_server->pairing_active = false; att_run_for_context(att_server, att_connection); break; // Authorization case SM_EVENT_AUTHORIZATION_RESULT: { con_handle = sm_event_authorization_result_get_handle(packet); hci_connection = hci_connection_for_handle(con_handle); if (!hci_connection) break; att_connection = &hci_connection->att_connection; att_server = &hci_connection->att_server; att_connection->authorized = sm_event_authorization_result_get_authorization_result(packet); att_server_request_can_send_now(att_server, att_connection); break; } default: break; } break; default: break; } } static uint8_t att_server_send_prepared(const att_server_t *att_server, const att_connection_t *att_connection, uint8_t *buffer, uint16_t size) { UNUSED(buffer); uint8_t status = ERROR_CODE_SUCCESS; switch (att_server->bearer_type) { case ATT_BEARER_UNENHANCED_LE: status = l2cap_send_prepared_connectionless(att_connection->con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, size); break; #ifdef ENABLE_GATT_OVER_CLASSIC case ATT_BEARER_UNENHANCED_CLASSIC: status = l2cap_send_prepared(att_server->l2cap_cid, size); break; #endif #ifdef ENABLE_GATT_OVER_EATT case ATT_BEARER_ENHANCED_LE: btstack_assert(buffer != NULL); status = l2cap_send(att_server->l2cap_cid, buffer, size); break; #endif default: btstack_unreachable(); break; } return status; } #ifdef ENABLE_LE_SIGNED_WRITE static void att_signed_write_handle_cmac_result(uint8_t hash[8]){ att_server_t * att_server = NULL; att_connection_t * att_connection = NULL; bool found = att_server_connections_for_state(ATT_SERVER_W4_SIGNED_WRITE_VALIDATION, &att_server, &att_connection); if (found == false){ return; } uint8_t hash_flipped[8]; reverse_64(hash, hash_flipped); if (memcmp(hash_flipped, &att_server->request_buffer[att_server->request_size-8], 8) != 0){ log_info("ATT Signed Write, invalid signature"); #ifdef ENABLE_TESTING_SUPPORT printf("ATT Signed Write, invalid signature\n"); #endif att_server->state = ATT_SERVER_IDLE; return; } log_info("ATT Signed Write, valid signature"); #ifdef ENABLE_TESTING_SUPPORT printf("ATT Signed Write, valid signature\n"); #endif // update sequence number uint32_t counter_packet = little_endian_read_32(att_server->request_buffer, att_server->request_size-12); le_device_db_remote_counter_set(att_server->ir_le_device_db_index, counter_packet+1); att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; att_server_request_can_send_now(att_server, att_connection); } #endif // pre: att_server->state == ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED // pre: can send now // uses l2cap outgoing buffer if no eatt_buffer provided // returns: 1 if packet was sent static int att_server_process_validated_request(att_server_t *att_server, att_connection_t *att_connection, uint8_t *eatt_buffer) { uint8_t * att_response_buffer; if (eatt_buffer != NULL){ att_response_buffer = eatt_buffer; } else { l2cap_reserve_packet_buffer(); att_response_buffer = l2cap_get_outgoing_buffer(); } uint16_t att_response_size = 0; // Send Error Response for MTU Request over connection-oriented channel if ((att_server->bearer_type != ATT_BEARER_UNENHANCED_LE) && (att_server->request_buffer[0] == ATT_EXCHANGE_MTU_REQUEST)){ att_response_size = 5; att_response_buffer[0] = ATT_ERROR_RESPONSE; att_response_buffer[1] = ATT_EXCHANGE_MTU_REQUEST; att_response_buffer[2] = 0; att_response_buffer[3] = 0; att_response_buffer[4] = ATT_ERROR_REQUEST_NOT_SUPPORTED; } else { att_response_size = att_handle_request(att_connection, att_server->request_buffer, att_server->request_size, att_response_buffer); } #ifdef ENABLE_ATT_DELAYED_RESPONSE if ((att_response_size == ATT_READ_RESPONSE_PENDING) || (att_response_size == ATT_INTERNAL_WRITE_RESPONSE_PENDING)){ // free reserved buffer if (eatt_buffer == NULL){ l2cap_release_packet_buffer(); } // update state att_server->state = ATT_SERVER_RESPONSE_PENDING; // callback with handle ATT_READ_RESPONSE_PENDING for reads if (att_response_size == ATT_READ_RESPONSE_PENDING){ // notify services that returned response pending btstack_linked_list_iterator_t it; btstack_linked_list_iterator_init(&it, &service_handlers); while (btstack_linked_list_iterator_has_next(&it)) { att_service_handler_t *handler = (att_service_handler_t *) btstack_linked_list_iterator_next(&it); if ((handler->flags & ATT_SERVICE_FLAGS_DELAYED_RESPONSE) != 0){ handler->flags &= ~ATT_SERVICE_FLAGS_DELAYED_RESPONSE; handler->read_callback(att_connection->con_handle, ATT_READ_RESPONSE_PENDING, 0, NULL, 0); } } // notify main read callback if it returned response pending if ((att_server_flags & ATT_SERVICE_FLAGS_DELAYED_RESPONSE) != 0){ // flag was set by read callback btstack_assert(att_server_client_read_callback != NULL); (*att_server_client_read_callback)(att_connection->con_handle, ATT_READ_RESPONSE_PENDING, 0, NULL, 0); } } return 0; } #endif // intercept "insufficient authorization" for authenticated connections to allow for user authorization if ((att_response_size >= 4u) && (att_response_buffer[0] == ATT_ERROR_RESPONSE) && (att_response_buffer[4] == ATT_ERROR_INSUFFICIENT_AUTHORIZATION) && (att_connection->authenticated != 0u)){ switch (gap_authorization_state(att_connection->con_handle)){ case AUTHORIZATION_UNKNOWN: if (eatt_buffer == NULL){ l2cap_release_packet_buffer(); } sm_request_pairing(att_connection->con_handle); return 0; case AUTHORIZATION_PENDING: if (eatt_buffer == NULL){ l2cap_release_packet_buffer(); } return 0; default: break; } } att_server->state = ATT_SERVER_IDLE; if (att_response_size == 0u) { if (eatt_buffer == NULL){ l2cap_release_packet_buffer(); } return 0; } (void) att_server_send_prepared(att_server, att_connection, eatt_buffer, att_response_size); // notify client about MTU exchange result if (att_response_buffer[0] == ATT_EXCHANGE_MTU_RESPONSE){ att_emit_mtu_event(att_connection->con_handle, att_connection->mtu); } return 1; } #ifdef ENABLE_ATT_DELAYED_RESPONSE uint8_t att_server_response_ready(hci_con_handle_t con_handle){ hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); if (!hci_connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; att_server_t * att_server = &hci_connection->att_server; att_connection_t * att_connection = &hci_connection->att_connection; if (att_server->state != ATT_SERVER_RESPONSE_PENDING) return ERROR_CODE_COMMAND_DISALLOWED; att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; att_server_request_can_send_now(att_server, att_connection); return ERROR_CODE_SUCCESS; } #endif static void att_run_for_context(att_server_t * att_server, att_connection_t * att_connection){ switch (att_server->state){ case ATT_SERVER_REQUEST_RECEIVED: switch (att_server->bearer_type){ case ATT_BEARER_UNENHANCED_LE: // wait until re-encryption as central is complete if (gap_reconnect_security_setup_active(att_connection->con_handle)) { return; }; break; #if defined(ENABLE_GATT_OVER_CLASSIC) || defined (ENABLE_GATT_OVER_EATT) #ifdef ENABLE_GATT_OVER_CLASSIC case ATT_BEARER_UNENHANCED_CLASSIC: /* fall through */ #endif #ifdef ENABLE_GATT_OVER_EATT case ATT_BEARER_ENHANCED_LE: #endif // ok break; #endif default: btstack_unreachable(); break; } // wait until pairing is complete if (att_server->pairing_active) break; #ifdef ENABLE_LE_SIGNED_WRITE if (att_server->request_buffer[0] == ATT_SIGNED_WRITE_COMMAND){ log_info("ATT Signed Write!"); if (!sm_cmac_ready()) { log_info("ATT Signed Write, sm_cmac engine not ready. Abort"); att_server->state = ATT_SERVER_IDLE; return; } if (att_server->request_size < (3 + 12)) { log_info("ATT Signed Write, request to short. Abort."); att_server->state = ATT_SERVER_IDLE; return; } if (att_server->ir_lookup_active){ return; } if (att_server->ir_le_device_db_index < 0){ log_info("ATT Signed Write, CSRK not available"); att_server->state = ATT_SERVER_IDLE; return; } // check counter uint32_t counter_packet = little_endian_read_32(att_server->request_buffer, att_server->request_size-12); uint32_t counter_db = le_device_db_remote_counter_get(att_server->ir_le_device_db_index); log_info("ATT Signed Write, DB counter %"PRIu32", packet counter %"PRIu32, counter_db, counter_packet); if (counter_packet < counter_db){ log_info("ATT Signed Write, db reports higher counter, abort"); att_server->state = ATT_SERVER_IDLE; return; } // signature is { sequence counter, secure hash } sm_key_t csrk; le_device_db_remote_csrk_get(att_server->ir_le_device_db_index, csrk); att_server->state = ATT_SERVER_W4_SIGNED_WRITE_VALIDATION; log_info("Orig Signature: "); log_info_hexdump( &att_server->request_buffer[att_server->request_size-8], 8); uint16_t attribute_handle = little_endian_read_16(att_server->request_buffer, 1); sm_cmac_signed_write_start(csrk, att_server->request_buffer[0], attribute_handle, att_server->request_size - 15, &att_server->request_buffer[3], counter_packet, att_signed_write_handle_cmac_result); return; } #endif // move on att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; att_server_request_can_send_now(att_server, att_connection); break; default: break; } } static bool att_server_data_ready_for_phase(att_server_t * att_server, att_server_run_phase_t phase){ switch (phase){ case ATT_SERVER_RUN_PHASE_1_REQUESTS: return att_server->state == ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; case ATT_SERVER_RUN_PHASE_2_INDICATIONS: return (!btstack_linked_list_empty(&att_server->indication_requests) && (att_server->value_indication_handle == 0u)); case ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS: return (!btstack_linked_list_empty(&att_server->notification_requests)); default: btstack_assert(false); return false; } } static void att_server_trigger_send_for_phase(att_server_t * att_server, att_connection_t * att_connection, att_server_run_phase_t phase){ btstack_context_callback_registration_t * client; switch (phase){ case ATT_SERVER_RUN_PHASE_1_REQUESTS: att_server_process_validated_request(att_server, att_connection, NULL); break; case ATT_SERVER_RUN_PHASE_2_INDICATIONS: client = (btstack_context_callback_registration_t*) att_server->indication_requests; btstack_linked_list_remove(&att_server->indication_requests, (btstack_linked_item_t *) client); client->callback(client->context); break; case ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS: client = (btstack_context_callback_registration_t*) att_server->notification_requests; btstack_linked_list_remove(&att_server->notification_requests, (btstack_linked_item_t *) client); client->callback(client->context); break; default: btstack_assert(false); break; } } static void att_server_handle_can_send_now(void){ hci_con_handle_t last_send_con_handle = HCI_CON_HANDLE_INVALID; hci_connection_t * request_hci_connection = NULL; bool can_send_now = true; uint8_t phase_index; for (phase_index = ATT_SERVER_RUN_PHASE_1_REQUESTS; phase_index <= ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS; phase_index++){ att_server_run_phase_t phase = (att_server_run_phase_t) phase_index; hci_con_handle_t skip_connections_until = att_server_last_can_send_now; while (true){ btstack_linked_list_iterator_t it; hci_connections_get_iterator(&it); while(btstack_linked_list_iterator_has_next(&it)){ hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); att_server_t * att_server = &connection->att_server; att_connection_t * att_connection = &connection->att_connection; bool data_ready = att_server_data_ready_for_phase(att_server, phase); // log_debug("phase %u, handle 0x%04x, skip until 0x%04x, data ready %u", phase, att_connection->con_handle, skip_connections_until, data_ready); // skip until last sender found (which is also skipped) if (skip_connections_until != HCI_CON_HANDLE_INVALID){ if (data_ready && (request_hci_connection == NULL)){ request_hci_connection = connection; } if (skip_connections_until == att_connection->con_handle){ skip_connections_until = HCI_CON_HANDLE_INVALID; } continue; }; if (data_ready){ if (can_send_now){ att_server_trigger_send_for_phase(att_server, att_connection, phase); last_send_con_handle = att_connection->con_handle; can_send_now = att_server_can_send_packet(att_server, att_connection); data_ready = att_server_data_ready_for_phase(att_server, phase); if (data_ready && (request_hci_connection == NULL)){ request_hci_connection = connection; } } else { request_hci_connection = connection; break; } } } // stop skipping (handles disconnect by last send connection) skip_connections_until = HCI_CON_HANDLE_INVALID; // Exit loop, if we cannot send if (!can_send_now) break; // Exit loop, if we can send but there are also no further request if (request_hci_connection == NULL) break; // Finally, if we still can send and there are requests, just try again request_hci_connection = NULL; } // update last send con handle for round robin if (last_send_con_handle != HCI_CON_HANDLE_INVALID){ att_server_last_can_send_now = last_send_con_handle; } } if (request_hci_connection == NULL) return; att_server_t * att_server = &request_hci_connection->att_server; att_connection_t * att_connection = &request_hci_connection->att_connection; att_server_request_can_send_now(att_server, att_connection); } static void att_server_handle_att_pdu(att_server_t * att_server, att_connection_t * att_connection, uint8_t * packet, uint16_t size){ uint8_t opcode = packet[0u]; uint8_t method = opcode & 0x03fu; bool invalid = method > ATT_MULTIPLE_HANDLE_VALUE_NTF; bool command = (opcode & 0x40u) != 0u; // ignore invalid commands if (invalid && command){ return; } // handle value indication confirms if ((opcode == ATT_HANDLE_VALUE_CONFIRMATION) && (att_server->value_indication_handle != 0u)){ btstack_run_loop_remove_timer(&att_server->value_indication_timer); uint16_t att_handle = att_server->value_indication_handle; att_server->value_indication_handle = 0u; att_handle_value_indication_notify_client(0u, att_connection->con_handle, att_handle); att_server_request_can_send_now(att_server, att_connection); return; } // directly process command // note: signed write cannot be handled directly as authentication needs to be verified if (opcode == ATT_WRITE_COMMAND){ att_handle_request(att_connection, packet, size, NULL); return; } // check size if (size > sizeof(att_server->request_buffer)) { log_info("drop att pdu 0x%02x as size %u > att_server->request_buffer %u", packet[0], size, (int) sizeof(att_server->request_buffer)); return; } #ifdef ENABLE_LE_SIGNED_WRITE // abort signed write validation if a new request comes in (but finish previous signed write if possible) if (att_server->state == ATT_SERVER_W4_SIGNED_WRITE_VALIDATION){ if (packet[0] == ATT_SIGNED_WRITE_COMMAND){ log_info("skip new signed write request as previous is in validation"); return; } else { log_info("abort signed write validation to process new request"); att_server->state = ATT_SERVER_IDLE; } } #endif // last request still in processing? if (att_server->state != ATT_SERVER_IDLE){ log_info("skip att pdu 0x%02x as server not idle (state %u)", packet[0], att_server->state); return; } // store request att_server->state = ATT_SERVER_REQUEST_RECEIVED; att_server->request_size = size; (void)memcpy(att_server->request_buffer, packet, size); att_run_for_context(att_server, att_connection); } static void att_server_dispatch_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ hci_connection_t * hci_connection; att_connection_t * att_connection; att_server_t * att_server; #ifdef ENABLE_GATT_OVER_CLASSIC hci_con_handle_t con_handle; bd_addr_t address; btstack_linked_list_iterator_t it; #endif switch (packet_type){ case HCI_EVENT_PACKET: switch (packet[0]){ #ifdef ENABLE_GATT_OVER_CLASSIC case L2CAP_EVENT_CHANNEL_OPENED: con_handle = l2cap_event_channel_opened_get_handle(packet); hci_connection = hci_connection_for_handle(con_handle); if (!hci_connection) break; att_server = &hci_connection->att_server; // store connection info att_server->bearer_type = ATT_BEARER_UNENHANCED_CLASSIC; att_server->peer_addr_type = BD_ADDR_TYPE_ACL; l2cap_event_channel_opened_get_address(packet, att_server->peer_address); att_connection = &hci_connection->att_connection; att_connection->con_handle = con_handle; // reset connection properties att_server->state = ATT_SERVER_IDLE; att_connection->mtu = l2cap_event_channel_opened_get_remote_mtu(packet); att_connection->max_mtu = l2cap_max_mtu(); if (att_connection->max_mtu > ATT_REQUEST_BUFFER_SIZE){ att_connection->max_mtu = ATT_REQUEST_BUFFER_SIZE; } log_info("Connection opened %s, l2cap cid %04x, mtu %u", bd_addr_to_str(address), att_server->l2cap_cid, att_connection->mtu); // update security params att_connection->encryption_key_size = gap_encryption_key_size(con_handle); att_connection->authenticated = gap_authenticated(con_handle); att_connection->secure_connection = gap_secure_connection(con_handle); log_info("encrypted key size %u, authenticated %u, secure connection %u", att_connection->encryption_key_size, att_connection->authenticated, att_connection->secure_connection); // notify connection opened att_emit_connected_event(att_server, att_connection); // restore persisten ccc if encrypted if ( gap_security_level(con_handle) >= LEVEL_2){ att_server_persistent_ccc_restore(att_server, att_connection); } // TODO: what to do about le device db? att_server->pairing_active = 0; break; #endif case L2CAP_EVENT_CAN_SEND_NOW: att_server_handle_can_send_now(); break; case ATT_EVENT_MTU_EXCHANGE_COMPLETE: // GATT client has negotiated the mtu for this connection hci_connection = hci_connection_for_handle(channel); if (!hci_connection) break; att_connection = &hci_connection->att_connection; att_connection->mtu = little_endian_read_16(packet, 4); break; default: break; } break; case ATT_DATA_PACKET: log_debug("ATT Packet, handle 0x%04x", channel); hci_connection = hci_connection_for_handle(channel); if (!hci_connection) break; att_server = &hci_connection->att_server; att_connection = &hci_connection->att_connection; att_server_handle_att_pdu(att_server, att_connection, packet, size); break; #ifdef ENABLE_GATT_OVER_CLASSIC case L2CAP_DATA_PACKET: hci_connections_get_iterator(&it); while(btstack_linked_list_iterator_has_next(&it)){ hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); att_server = &hci_connection->att_server; att_connection = &hci_connection->att_connection; if (att_server->l2cap_cid == channel) { att_server_handle_att_pdu(att_server, att_connection, packet, size); break; } } break; #endif default: break; } } // --------------------- // persistent CCC writes static uint32_t att_server_persistent_ccc_tag_for_index(uint8_t index){ return ('B' << 24u) | ('T' << 16u) | ('C' << 8u) | index; } static void att_server_persistent_ccc_write(hci_con_handle_t con_handle, uint16_t att_handle, uint16_t value){ // lookup att_server instance hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); if (!hci_connection) return; att_server_t * att_server = &hci_connection->att_server; int le_device_index = att_server->ir_le_device_db_index; log_info("Store CCC value 0x%04x for handle 0x%04x of remote %s, le device id %d", value, att_handle, bd_addr_to_str(att_server->peer_address), le_device_index); // check if bonded if (le_device_index < 0) return; // get btstack_tlv const btstack_tlv_t * tlv_impl = NULL; void * tlv_context; btstack_tlv_get_instance(&tlv_impl, &tlv_context); if (!tlv_impl) return; // update ccc tag int index; uint32_t highest_seq_nr = 0; uint32_t lowest_seq_nr = 0; uint32_t tag_for_lowest_seq_nr = 0; uint32_t tag_for_empty = 0; persistent_ccc_entry_t entry; for (index=0; indexget_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); // empty/invalid tag if (len != sizeof(persistent_ccc_entry_t)){ tag_for_empty = tag; continue; } // update highest seq nr if (entry.seq_nr > highest_seq_nr){ highest_seq_nr = entry.seq_nr; } // find entry with lowest seq nr if ((tag_for_lowest_seq_nr == 0u) || (entry.seq_nr < lowest_seq_nr)){ tag_for_lowest_seq_nr = tag; lowest_seq_nr = entry.seq_nr; } if (entry.device_index != le_device_index) continue; if (entry.att_handle != att_handle) continue; // found matching entry if (value != 0){ // update if (entry.value == value) { log_info("CCC Index %u: Up-to-date", index); return; } entry.value = (uint8_t) value; entry.seq_nr = highest_seq_nr + 1u; log_info("CCC Index %u: Store", index); int result = tlv_impl->store_tag(tlv_context, tag, (const uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); if (result != 0){ log_error("Store tag index %u failed", index); } } else { // delete log_info("CCC Index %u: Delete", index); tlv_impl->delete_tag(tlv_context, tag); } return; } log_info("tag_for_empty %"PRIx32", tag_for_lowest_seq_nr %"PRIx32, tag_for_empty, tag_for_lowest_seq_nr); if (value == 0u){ // done return; } uint32_t tag_to_use = 0u; if (tag_for_empty != 0u){ tag_to_use = tag_for_empty; } else if (tag_for_lowest_seq_nr != 0){ tag_to_use = tag_for_lowest_seq_nr; } else { // should not happen return; } // store ccc tag entry.seq_nr = highest_seq_nr + 1u; entry.device_index = le_device_index; entry.att_handle = att_handle; entry.value = (uint8_t) value; int result = tlv_impl->store_tag(tlv_context, tag_to_use, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); if (result != 0){ log_error("Store tag index %u failed", index); } } static void att_server_persistent_ccc_clear(att_server_t * att_server){ int le_device_index = att_server->ir_le_device_db_index; log_info("Clear CCC values of remote %s, le device id %d", bd_addr_to_str(att_server->peer_address), le_device_index); // check if bonded if (le_device_index < 0) return; // get btstack_tlv const btstack_tlv_t * tlv_impl = NULL; void * tlv_context; btstack_tlv_get_instance(&tlv_impl, &tlv_context); if (!tlv_impl) return; // get all ccc tag int index; persistent_ccc_entry_t entry; for (index=0;indexget_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); if (len != sizeof(persistent_ccc_entry_t)) continue; if (entry.device_index != le_device_index) continue; // delete entry log_info("CCC Index %u: Delete", index); tlv_impl->delete_tag(tlv_context, tag); } } static void att_server_persistent_ccc_restore(att_server_t * att_server, att_connection_t * att_connection){ int le_device_index = att_server->ir_le_device_db_index; log_info("Restore CCC values of remote %s, le device id %d", bd_addr_to_str(att_server->peer_address), le_device_index); // check if bonded if (le_device_index < 0) return; // get btstack_tlv const btstack_tlv_t * tlv_impl = NULL; void * tlv_context; btstack_tlv_get_instance(&tlv_impl, &tlv_context); if (!tlv_impl) return; // get all ccc tag int index; persistent_ccc_entry_t entry; for (index=0;indexget_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); if (len != sizeof(persistent_ccc_entry_t)) continue; if (entry.device_index != le_device_index) continue; // simulate write callback uint16_t attribute_handle = entry.att_handle; uint8_t value[2]; little_endian_store_16(value, 0, entry.value); att_write_callback_t callback = att_server_write_callback_for_handle(attribute_handle); if (!callback) continue; log_info("CCC Index %u: Set Attribute handle 0x%04x to value 0x%04x", index, attribute_handle, entry.value ); (*callback)(att_connection->con_handle, attribute_handle, ATT_TRANSACTION_MODE_NONE, 0, value, sizeof(value)); } } // persistent CCC writes // --------------------- // gatt service management static att_service_handler_t * att_service_handler_for_handle(uint16_t handle){ btstack_linked_list_iterator_t it; btstack_linked_list_iterator_init(&it, &service_handlers); while (btstack_linked_list_iterator_has_next(&it)){ att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); if (handler->start_handle > handle) continue; if (handler->end_handle < handle) continue; return handler; } return NULL; } static att_write_callback_t att_server_write_callback_for_handle(uint16_t handle){ att_service_handler_t * handler = att_service_handler_for_handle(handle); if (handler != NULL) return handler->write_callback; return att_server_client_write_callback; } static btstack_packet_handler_t att_server_packet_handler_for_handle(uint16_t handle){ att_service_handler_t * handler = att_service_handler_for_handle(handle); if (handler != NULL) return handler->packet_handler; return att_client_packet_handler; } static void att_notify_write_callbacks(hci_con_handle_t con_handle, uint16_t transaction_mode){ // notify all callbacks btstack_linked_list_iterator_t it; btstack_linked_list_iterator_init(&it, &service_handlers); while (btstack_linked_list_iterator_has_next(&it)){ att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); if (!handler->write_callback) continue; (*handler->write_callback)(con_handle, 0, transaction_mode, 0, NULL, 0); } if (!att_server_client_write_callback) return; (*att_server_client_write_callback)(con_handle, 0, transaction_mode, 0, NULL, 0); } // returns first reported error or 0 static uint8_t att_validate_prepared_write(hci_con_handle_t con_handle){ btstack_linked_list_iterator_t it; btstack_linked_list_iterator_init(&it, &service_handlers); while (btstack_linked_list_iterator_has_next(&it)){ att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); if (!handler->write_callback) continue; uint8_t error_code = (*handler->write_callback)(con_handle, 0, ATT_TRANSACTION_MODE_VALIDATE, 0, NULL, 0); if (error_code != 0u) return error_code; } if (!att_server_client_write_callback) return 0; return (*att_server_client_write_callback)(con_handle, 0, ATT_TRANSACTION_MODE_VALIDATE, 0, NULL, 0); } static uint16_t att_server_read_callback(hci_con_handle_t con_handle, uint16_t attribute_handle, uint16_t offset, uint8_t * buffer, uint16_t buffer_size){ att_service_handler_t * service = att_service_handler_for_handle(attribute_handle); att_read_callback_t read_callback = (service != NULL) ? service->read_callback : att_server_client_read_callback; uint16_t result = 0; if (read_callback != NULL){ result = (*read_callback)(con_handle, attribute_handle, offset, buffer, buffer_size); #ifdef ENABLE_ATT_DELAYED_RESPONSE if (result == ATT_READ_RESPONSE_PENDING){ if (service == NULL){ att_server_flags |= ATT_SERVICE_FLAGS_DELAYED_RESPONSE; } else { service->flags |= ATT_SERVICE_FLAGS_DELAYED_RESPONSE; } } #endif } return result; } static int att_server_write_callback(hci_con_handle_t con_handle, uint16_t attribute_handle, uint16_t transaction_mode, uint16_t offset, uint8_t *buffer, uint16_t buffer_size){ switch (transaction_mode){ case ATT_TRANSACTION_MODE_VALIDATE: return att_validate_prepared_write(con_handle); case ATT_TRANSACTION_MODE_EXECUTE: case ATT_TRANSACTION_MODE_CANCEL: att_notify_write_callbacks(con_handle, transaction_mode); return 0; default: break; } // track CCC writes if (att_is_persistent_ccc(attribute_handle) && (offset == 0u) && (buffer_size == 2u)){ att_server_persistent_ccc_write(con_handle, attribute_handle, little_endian_read_16(buffer, 0)); } att_write_callback_t callback = att_server_write_callback_for_handle(attribute_handle); if (!callback) return 0; return (*callback)(con_handle, attribute_handle, transaction_mode, offset, buffer, buffer_size); } /** * @brief register read/write callbacks for specific handle range * @param att_service_handler_t */ void att_server_register_service_handler(att_service_handler_t * handler){ bool att_server_registered = false; if (att_service_handler_for_handle(handler->start_handle) != NULL){ att_server_registered = true; } if (att_service_handler_for_handle(handler->end_handle) != NULL){ att_server_registered = true; } if (att_server_registered){ log_error("handler for range 0x%04x-0x%04x already registered", handler->start_handle, handler->end_handle); return; } handler->flags = 0; btstack_linked_list_add(&service_handlers, (btstack_linked_item_t*) handler); } void att_server_init(uint8_t const * db, att_read_callback_t read_callback, att_write_callback_t write_callback){ // store callbacks att_server_client_read_callback = read_callback; att_server_client_write_callback = write_callback; // register for HCI Events hci_event_callback_registration.callback = &att_server_event_packet_handler; hci_add_event_handler(&hci_event_callback_registration); // register for SM events sm_event_callback_registration.callback = &att_server_event_packet_handler; sm_add_event_handler(&sm_event_callback_registration); // and L2CAP ATT Server PDUs att_dispatch_register_server(att_server_dispatch_packet_handler); #ifdef ENABLE_GATT_OVER_CLASSIC // setup l2cap service att_dispatch_classic_register_service(); #endif att_set_db(db); att_set_read_callback(att_server_read_callback); att_set_write_callback(att_server_write_callback); } void att_server_register_packet_handler(btstack_packet_handler_t handler){ att_client_packet_handler = handler; } // to be deprecated int att_server_can_send_packet_now(hci_con_handle_t con_handle){ hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); if (!hci_connection) return 0; att_server_t * att_server = &hci_connection->att_server; att_connection_t * att_connection = &hci_connection->att_connection; return att_server_can_send_packet(att_server, att_connection); } uint8_t att_server_register_can_send_now_callback(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ return att_server_request_to_send_notification(callback_registration, con_handle); } void att_server_request_can_send_now_event(hci_con_handle_t con_handle){ att_client_waiting_for_can_send_registration.callback = &att_emit_can_send_now_event; att_server_request_to_send_notification(&att_client_waiting_for_can_send_registration, con_handle); } // end of deprecated uint8_t att_server_request_to_send_notification(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); if (!hci_connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; att_server_t * att_server = &hci_connection->att_server; att_connection_t * att_connection = &hci_connection->att_connection; bool added = btstack_linked_list_add_tail(&att_server->notification_requests, (btstack_linked_item_t*) callback_registration); att_server_request_can_send_now(att_server, att_connection); if (added){ return ERROR_CODE_SUCCESS; } else { return ERROR_CODE_COMMAND_DISALLOWED; } } uint8_t att_server_request_to_send_indication(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); if (!hci_connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; att_server_t * att_server = &hci_connection->att_server; att_connection_t * att_connection = &hci_connection->att_connection; bool added = btstack_linked_list_add_tail(&att_server->indication_requests, (btstack_linked_item_t*) callback_registration); att_server_request_can_send_now(att_server, att_connection); if (added){ return ERROR_CODE_SUCCESS; } else { return ERROR_CODE_COMMAND_DISALLOWED; } } static uint8_t att_server_prepare_server_message(hci_con_handle_t con_handle, att_server_t ** out_att_server, att_connection_t ** out_att_connection, uint8_t ** out_packet_buffer){ att_server_t * att_server = NULL; att_connection_t * att_connection = NULL; uint8_t * packet_buffer = NULL; // prefer enhanced bearer #ifdef ENABLE_GATT_OVER_EATT att_server_eatt_bearer_t * eatt_bearer = att_server_eatt_bearer_for_con_handle(con_handle); if (eatt_bearer != NULL){ att_server = &eatt_bearer->att_server; att_connection = &eatt_bearer->att_connection; packet_buffer = eatt_bearer->send_buffer; } else #endif { hci_connection_t *hci_connection = hci_connection_for_handle(con_handle); if (hci_connection != NULL) { att_server = &hci_connection->att_server; att_connection = &hci_connection->att_connection; } } if (att_server == NULL) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; if (!att_server_can_send_packet(att_server, att_connection)) return BTSTACK_ACL_BUFFERS_FULL; if (packet_buffer == NULL){ l2cap_reserve_packet_buffer(); packet_buffer = l2cap_get_outgoing_buffer(); } *out_att_connection = att_connection; *out_att_server = att_server; *out_packet_buffer = packet_buffer; return ERROR_CODE_SUCCESS; } uint8_t att_server_notify(hci_con_handle_t con_handle, uint16_t attribute_handle, const uint8_t *value, uint16_t value_len){ att_server_t * att_server = NULL; att_connection_t * att_connection = NULL; uint8_t * packet_buffer = NULL; uint8_t status = att_server_prepare_server_message(con_handle, &att_server, &att_connection, &packet_buffer); if (status != ERROR_CODE_SUCCESS){ return status; } uint16_t size = att_prepare_handle_value_notification(att_connection, attribute_handle, value, value_len, packet_buffer); return att_server_send_prepared(att_server, att_connection, NULL, size); } /** * @brief notify client about multiple attribute value changes * @param con_handle * @param num_attributes * @param attribute_handles[] * @param values_data[] * @param values_len[] * @return 0 if ok, error otherwise */ uint8_t att_server_multiple_notify(hci_con_handle_t con_handle, uint8_t num_attributes, const uint16_t * attribute_handles, const uint8_t ** values_data, const uint16_t * values_len){ att_server_t * att_server = NULL; att_connection_t * att_connection = NULL; uint8_t * packet_buffer = NULL; uint8_t status = att_server_prepare_server_message(con_handle, &att_server, &att_connection, &packet_buffer); if (status != ERROR_CODE_SUCCESS){ return status; } uint16_t size = att_prepare_handle_value_multiple_notification(att_connection, num_attributes, attribute_handles, values_data, values_len, packet_buffer); return att_server_send_prepared(att_server, att_connection, packet_buffer, size); } uint8_t att_server_indicate(hci_con_handle_t con_handle, uint16_t attribute_handle, const uint8_t *value, uint16_t value_len){ att_server_t * att_server = NULL; att_connection_t * att_connection = NULL; uint8_t * packet_buffer = NULL; uint8_t status = att_server_prepare_server_message(con_handle, &att_server, &att_connection, &packet_buffer); if (status != ERROR_CODE_SUCCESS){ return status; } if (att_server->value_indication_handle != 0u) { // free reserved packet buffer if (att_server->bearer_type == ATT_BEARER_ENHANCED_LE){ l2cap_release_packet_buffer(); } return ATT_HANDLE_VALUE_INDICATION_IN_PROGRESS; } // track indication att_server->value_indication_handle = attribute_handle; btstack_run_loop_set_timer_handler(&att_server->value_indication_timer, att_handle_value_indication_timeout); btstack_run_loop_set_timer(&att_server->value_indication_timer, ATT_TRANSACTION_TIMEOUT_MS); btstack_run_loop_add_timer(&att_server->value_indication_timer); uint16_t size = att_prepare_handle_value_indication(att_connection, attribute_handle, value, value_len, packet_buffer); return att_server_send_prepared(att_server, att_connection, NULL, size); } uint16_t att_server_get_mtu(hci_con_handle_t con_handle){ hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); if (!hci_connection) return 0; att_connection_t * att_connection = &hci_connection->att_connection; return att_connection->mtu; } void att_server_deinit(void){ att_server_client_read_callback = NULL; att_server_client_write_callback = NULL; att_client_packet_handler = NULL; service_handlers = NULL; att_server_flags = 0; } #ifdef ENABLE_GATT_OVER_EATT #define MAX_NR_EATT_CHANNELS 5 static uint16_t att_server_eatt_receive_buffer_size; static uint16_t att_server_eatt_send_buffer_size; static att_server_eatt_bearer_t * att_server_eatt_bearer_for_cid(uint16_t cid){ btstack_linked_list_iterator_t it; btstack_linked_list_iterator_init(&it, &att_server_eatt_bearer_active); while(btstack_linked_list_iterator_has_next(&it)){ att_server_eatt_bearer_t * eatt_bearer = (att_server_eatt_bearer_t *) btstack_linked_list_iterator_next(&it); if (eatt_bearer->att_server.l2cap_cid == cid) { return eatt_bearer; } } return NULL; } static att_server_eatt_bearer_t * att_server_eatt_bearer_for_con_handle(hci_con_handle_t con_handle){ btstack_linked_list_iterator_t it; btstack_linked_list_iterator_init(&it, &att_server_eatt_bearer_active); while(btstack_linked_list_iterator_has_next(&it)){ att_server_eatt_bearer_t * eatt_bearer = (att_server_eatt_bearer_t *) btstack_linked_list_iterator_next(&it); if (eatt_bearer->att_connection.con_handle == con_handle) { return eatt_bearer; } } return NULL; } static void att_server_eatt_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ uint16_t cid; uint8_t status; uint16_t remote_mtu; uint8_t i; uint8_t num_requested_bearers; uint8_t num_accepted_bearers; uint16_t initial_credits = L2CAP_LE_AUTOMATIC_CREDITS; uint8_t * receive_buffers[MAX_NR_EATT_CHANNELS]; uint16_t cids[MAX_NR_EATT_CHANNELS]; att_server_eatt_bearer_t * eatt_bearers[MAX_NR_EATT_CHANNELS]; att_server_eatt_bearer_t * eatt_bearer; att_server_t * att_server; att_connection_t * att_connection; hci_con_handle_t con_handle; hci_connection_t * hci_connection; switch (packet_type) { case L2CAP_DATA_PACKET: eatt_bearer = att_server_eatt_bearer_for_cid(channel); btstack_assert(eatt_bearer != NULL); att_server = &eatt_bearer->att_server; att_connection = &eatt_bearer->att_connection; att_server_handle_att_pdu(att_server, att_connection, packet, size); break; case HCI_EVENT_PACKET: switch (packet[0]) { case L2CAP_EVENT_CAN_SEND_NOW: cid = l2cap_event_packet_sent_get_local_cid(packet); eatt_bearer = att_server_eatt_bearer_for_cid(cid); btstack_assert(eatt_bearer != NULL); att_server = &eatt_bearer->att_server; att_connection = &eatt_bearer->att_connection; // only used for EATT request responses btstack_assert(att_server->state == ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED); att_server_process_validated_request(att_server, att_connection, eatt_bearer->send_buffer); break; case L2CAP_EVENT_PACKET_SENT: cid = l2cap_event_packet_sent_get_local_cid(packet); eatt_bearer = att_server_eatt_bearer_for_cid(cid); btstack_assert(eatt_bearer != NULL); att_server = &eatt_bearer->att_server; att_connection = &eatt_bearer->att_connection; att_server_handle_att_pdu(att_server, att_connection, packet, size); break; case L2CAP_EVENT_ECBM_INCOMING_CONNECTION: cid = l2cap_event_ecbm_incoming_connection_get_local_cid(packet); // reject if outgoing l2cap connection active, L2CAP/TIM/BV-01-C con_handle = l2cap_event_ecbm_incoming_connection_get_handle(packet); hci_connection = hci_connection_for_handle(con_handle); btstack_assert(hci_connection != NULL); if (hci_connection->att_server.eatt_outgoing_active) { hci_connection->att_server.incoming_connection_request = true; l2cap_ecbm_decline_channels(cid, L2CAP_ECBM_CONNECTION_RESULT_SOME_REFUSED_INSUFFICIENT_RESOURCES_AVAILABLE ); log_info("Decline incoming connection from %s", bd_addr_to_str(hci_connection->address)); } else { num_requested_bearers = l2cap_event_ecbm_incoming_connection_get_num_channels(packet); for (i = 0; i < num_requested_bearers; i++){ eatt_bearers[i] = (att_server_eatt_bearer_t *) btstack_linked_list_pop(&att_server_eatt_bearer_pool); if (eatt_bearers[i] == NULL) { break; } eatt_bearers[i]->att_connection.con_handle = l2cap_event_ecbm_incoming_connection_get_handle(packet); eatt_bearers[i]->att_server.bearer_type = ATT_BEARER_ENHANCED_LE; receive_buffers[i] = eatt_bearers[i]->receive_buffer; btstack_linked_list_add(&att_server_eatt_bearer_active, (btstack_linked_item_t *) eatt_bearers[i]); } num_accepted_bearers = i; status = l2cap_ecbm_accept_channels(cid, num_accepted_bearers, initial_credits, att_server_eatt_receive_buffer_size, receive_buffers, cids); btstack_assert(status == ERROR_CODE_SUCCESS); log_info("requested %u, accepted %u", num_requested_bearers, num_accepted_bearers); for (i=0;iatt_server.l2cap_cid = cids[i]; } } break; case L2CAP_EVENT_ECBM_CHANNEL_OPENED: cid = l2cap_event_ecbm_channel_opened_get_local_cid(packet); status = l2cap_event_ecbm_channel_opened_get_status(packet); remote_mtu = l2cap_event_ecbm_channel_opened_get_remote_mtu(packet); eatt_bearer = att_server_eatt_bearer_for_cid(cid); btstack_assert(eatt_bearer != NULL); eatt_bearer->att_connection.mtu_exchanged = true; eatt_bearer->att_connection.mtu = remote_mtu; eatt_bearer->att_connection.max_mtu = remote_mtu; log_info("L2CAP_EVENT_ECBM_CHANNEL_OPENED - cid 0x%04x mtu %u, status 0x%02x", cid, remote_mtu, status); break; case L2CAP_EVENT_ECBM_RECONFIGURED: break; case L2CAP_EVENT_CHANNEL_CLOSED: eatt_bearer = att_server_eatt_bearer_for_cid(l2cap_event_channel_closed_get_local_cid(packet)); btstack_assert(eatt_bearers != NULL); // TODO: finalize - abort queued writes btstack_linked_list_remove(&att_server_eatt_bearer_active, (btstack_linked_item_t *) eatt_bearer); btstack_linked_list_add(&att_server_eatt_bearer_pool, (btstack_linked_item_t *) eatt_bearer); break; default: break; } break; default: btstack_unreachable(); break; } } // create eatt bearers uint8_t att_server_eatt_init(uint8_t num_eatt_bearers, uint8_t * storage_buffer, uint16_t storage_size){ uint16_t size_for_structs = num_eatt_bearers * sizeof(att_server_eatt_bearer_t); if (storage_size < size_for_structs) { return ERROR_CODE_MEMORY_CAPACITY_EXCEEDED; } // TODO: The minimum ATT_MTU for an Enhanced ATT bearer is 64 octets. memset(storage_buffer, 0, storage_size); uint16_t buffer_size_per_bearer = ((storage_size - size_for_structs) / num_eatt_bearers); att_server_eatt_receive_buffer_size = buffer_size_per_bearer / 2; att_server_eatt_send_buffer_size = buffer_size_per_bearer / 2; uint8_t * bearer_buffer = &storage_buffer[size_for_structs]; uint8_t i; att_server_eatt_bearer_t * eatt_bearer = (att_server_eatt_bearer_t *) storage_buffer; log_info("%u EATT bearers with receive buffer size %u", num_eatt_bearers, att_server_eatt_receive_buffer_size); for (i=0;iatt_connection.con_handle = HCI_CON_HANDLE_INVALID; eatt_bearer->receive_buffer = bearer_buffer; bearer_buffer += att_server_eatt_receive_buffer_size; eatt_bearer->send_buffer = bearer_buffer; bearer_buffer += att_server_eatt_send_buffer_size; btstack_linked_list_add(&att_server_eatt_bearer_pool, (btstack_linked_item_t *) eatt_bearer); eatt_bearer++; } // TODO: define minimum EATT MTU l2cap_ecbm_register_service(att_server_eatt_handler, BLUETOOTH_PSM_EATT, 64, 0, false); return 0; } #endif