1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BLUEKITCHEN 24 * GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 #define BTSTACK_FILE__ "att_server.c" 39 40 41 // 42 // ATT Server Globals 43 // 44 45 #include <stdint.h> 46 #include <string.h> 47 #include <inttypes.h> 48 49 #include "btstack_config.h" 50 51 #include "ble/att_dispatch.h" 52 #include "ble/att_db.h" 53 #include "ble/att_server.h" 54 #include "ble/core.h" 55 #include "ble/le_device_db.h" 56 #include "ble/sm.h" 57 #include "btstack_debug.h" 58 #include "btstack_event.h" 59 #include "btstack_memory.h" 60 #include "btstack_run_loop.h" 61 #include "gap.h" 62 #include "hci.h" 63 #include "hci_dump.h" 64 #include "l2cap.h" 65 #include "btstack_tlv.h" 66 #ifdef ENABLE_LE_SIGNED_WRITE 67 #include "ble/sm.h" 68 #include "bluetooth_psm.h" 69 70 #endif 71 72 #ifdef ENABLE_TESTING_SUPPORT 73 #include <stdio.h> 74 #endif 75 76 #ifndef NVN_NUM_GATT_SERVER_CCC 77 #define NVN_NUM_GATT_SERVER_CCC 20 78 #endif 79 80 static void att_run_for_context(att_server_t * att_server, att_connection_t * att_connection); 81 static att_write_callback_t att_server_write_callback_for_handle(uint16_t handle); 82 static btstack_packet_handler_t att_server_packet_handler_for_handle(uint16_t handle); 83 static void att_server_handle_can_send_now(void); 84 static void att_server_persistent_ccc_restore(att_server_t * att_server, att_connection_t * att_connection); 85 static void att_server_persistent_ccc_clear(att_server_t * att_server); 86 static void att_server_handle_att_pdu(att_server_t * att_server, att_connection_t * att_connection, uint8_t * packet, uint16_t size); 87 88 typedef enum { 89 ATT_SERVER_RUN_PHASE_1_REQUESTS = 0, 90 ATT_SERVER_RUN_PHASE_2_INDICATIONS, 91 ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS, 92 } att_server_run_phase_t; 93 94 // 95 typedef struct { 96 uint32_t seq_nr; 97 uint16_t att_handle; 98 uint8_t value; 99 uint8_t device_index; 100 } persistent_ccc_entry_t; 101 102 // global 103 static btstack_packet_callback_registration_t hci_event_callback_registration; 104 static btstack_packet_callback_registration_t sm_event_callback_registration; 105 static btstack_packet_handler_t att_client_packet_handler; 106 static btstack_linked_list_t service_handlers; 107 static btstack_context_callback_registration_t att_client_waiting_for_can_send_registration; 108 109 static att_read_callback_t att_server_client_read_callback; 110 static att_write_callback_t att_server_client_write_callback; 111 112 // round robin 113 static hci_con_handle_t att_server_last_can_send_now = HCI_CON_HANDLE_INVALID; 114 115 #ifdef ENABLE_GATT_OVER_EATT 116 typedef struct { 117 btstack_linked_item_t item; 118 att_server_t att_server; 119 att_connection_t att_connection; 120 uint8_t * receive_buffer; 121 uint8_t * send_buffer; 122 } att_server_eatt_bearer_t; 123 static att_server_eatt_bearer_t * att_server_eatt_bearer_for_con_handle(hci_con_handle_t con_handle); 124 static btstack_linked_list_t att_server_eatt_bearer_pool; 125 static btstack_linked_list_t att_server_eatt_bearer_active; 126 #endif 127 128 #ifdef ENABLE_LE_SIGNED_WRITE 129 static bool att_server_connections_for_state(att_server_state_t state, att_server_t ** att_server_out, att_connection_t ** att_connection_out){ 130 btstack_linked_list_iterator_t it; 131 hci_connections_get_iterator(&it); 132 while(btstack_linked_list_iterator_has_next(&it)){ 133 hci_connection_t * hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 134 if (hci_connection->att_server.state == state) { 135 *att_server_out = &hci_connection->att_server; 136 *att_connection_out = &hci_connection->att_connection; 137 return true; 138 } 139 } 140 141 #ifdef ENABLE_GATT_OVER_EATT 142 btstack_linked_list_iterator_init(&it, &att_server_eatt_bearer_active); 143 while(btstack_linked_list_iterator_has_next(&it)){ 144 att_server_eatt_bearer_t * eatt_bearer = (att_server_eatt_bearer_t *) btstack_linked_list_iterator_next(&it); 145 if (eatt_bearer->att_server.state == state) { 146 *att_server_out = &eatt_bearer->att_server; 147 *att_connection_out = &eatt_bearer->att_connection; 148 return true; 149 } 150 } 151 #endif 152 153 return false; 154 } 155 #endif 156 157 static void att_server_request_can_send_now(att_server_t * att_server, att_connection_t * att_connection ){ 158 switch (att_server->bearer_type){ 159 case ATT_BEARER_UNENHANCED_LE: 160 #ifdef ENABLE_GATT_OVER_CLASSIC 161 case ATT_BEARER_UNENHANCED_CLASSIC: 162 /* fall through */ 163 #endif 164 att_dispatch_server_request_can_send_now_event(att_connection->con_handle); 165 break; 166 #ifdef ENABLE_GATT_OVER_EATT 167 case ATT_BEARER_ENHANCED_LE: 168 l2cap_request_can_send_now_event(att_server->l2cap_cid); 169 break; 170 #endif 171 default: 172 btstack_unreachable(); 173 break; 174 } 175 } 176 177 static bool att_server_can_send_packet(att_server_t * att_server, att_connection_t * att_connection){ 178 switch (att_server->bearer_type) { 179 case ATT_BEARER_UNENHANCED_LE: 180 #ifdef ENABLE_GATT_OVER_CLASSIC 181 case ATT_BEARER_UNENHANCED_CLASSIC: 182 /* fall through */ 183 #endif 184 return att_dispatch_server_can_send_now(att_connection->con_handle); 185 #ifdef ENABLE_GATT_OVER_EATT 186 case ATT_BEARER_ENHANCED_LE: 187 return l2cap_can_send_packet_now(att_server->l2cap_cid); 188 #endif 189 default: 190 btstack_unreachable(); 191 break; 192 } 193 return false; 194 } 195 196 static void att_handle_value_indication_notify_client(uint8_t status, uint16_t client_handle, uint16_t attribute_handle){ 197 btstack_packet_handler_t packet_handler = att_server_packet_handler_for_handle(attribute_handle); 198 if (!packet_handler) return; 199 200 uint8_t event[7]; 201 int pos = 0; 202 event[pos++] = ATT_EVENT_HANDLE_VALUE_INDICATION_COMPLETE; 203 event[pos++] = sizeof(event) - 2u; 204 event[pos++] = status; 205 little_endian_store_16(event, pos, client_handle); 206 pos += 2; 207 little_endian_store_16(event, pos, attribute_handle); 208 (*packet_handler)(HCI_EVENT_PACKET, 0, &event[0], sizeof(event)); 209 } 210 211 static void att_emit_event_to_all(const uint8_t * event, uint16_t size){ 212 // dispatch to app level handler 213 if (att_client_packet_handler != NULL){ 214 (*att_client_packet_handler)(HCI_EVENT_PACKET, 0, (uint8_t*) event, size); 215 } 216 217 // dispatch to service handlers 218 btstack_linked_list_iterator_t it; 219 btstack_linked_list_iterator_init(&it, &service_handlers); 220 while (btstack_linked_list_iterator_has_next(&it)){ 221 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 222 if (!handler->packet_handler) continue; 223 (*handler->packet_handler)(HCI_EVENT_PACKET, 0, (uint8_t*) event, size); 224 } 225 } 226 227 static void att_emit_mtu_event(hci_con_handle_t con_handle, uint16_t mtu){ 228 uint8_t event[6]; 229 int pos = 0; 230 event[pos++] = ATT_EVENT_MTU_EXCHANGE_COMPLETE; 231 event[pos++] = sizeof(event) - 2u; 232 little_endian_store_16(event, pos, con_handle); 233 pos += 2; 234 little_endian_store_16(event, pos, mtu); 235 236 // also dispatch to GATT Clients 237 att_dispatch_server_mtu_exchanged(con_handle, mtu); 238 239 // dispatch to app level handler and service handlers 240 att_emit_event_to_all(&event[0], sizeof(event)); 241 } 242 243 static void att_emit_can_send_now_event(void * context){ 244 UNUSED(context); 245 if (!att_client_packet_handler) return; 246 247 uint8_t event[] = { ATT_EVENT_CAN_SEND_NOW, 0}; 248 (*att_client_packet_handler)(HCI_EVENT_PACKET, 0, &event[0], sizeof(event)); 249 } 250 251 static void att_emit_connected_event(att_server_t * att_server, att_connection_t * att_connection){ 252 uint8_t event[11]; 253 int pos = 0; 254 event[pos++] = ATT_EVENT_CONNECTED; 255 event[pos++] = sizeof(event) - 2u; 256 event[pos++] = att_server->peer_addr_type; 257 reverse_bd_addr(att_server->peer_address, &event[pos]); 258 pos += 6; 259 little_endian_store_16(event, pos, att_connection->con_handle); 260 pos += 2; 261 262 // dispatch to app level handler and service handlers 263 att_emit_event_to_all(&event[0], sizeof(event)); 264 } 265 266 267 static void att_emit_disconnected_event(uint16_t con_handle){ 268 uint8_t event[4]; 269 int pos = 0; 270 event[pos++] = ATT_EVENT_DISCONNECTED; 271 event[pos++] = sizeof(event) - 2u; 272 little_endian_store_16(event, pos, con_handle); 273 pos += 2; 274 275 // dispatch to app level handler and service handlers 276 att_emit_event_to_all(&event[0], sizeof(event)); 277 } 278 279 static void att_handle_value_indication_timeout(btstack_timer_source_t *ts){ 280 void * context = btstack_run_loop_get_timer_context(ts); 281 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) context; 282 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 283 if (!hci_connection) return; 284 // @note: after a transaction timeout, no more requests shall be sent over this ATT Bearer 285 // (that's why we don't reset the value_indication_handle) 286 att_server_t * att_server = &hci_connection->att_server; 287 uint16_t att_handle = att_server->value_indication_handle; 288 att_connection_t * att_connection = &hci_connection->att_connection; 289 att_handle_value_indication_notify_client((uint8_t)ATT_HANDLE_VALUE_INDICATION_TIMEOUT, att_connection->con_handle, att_handle); 290 } 291 292 static void att_server_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 293 294 UNUSED(channel); // ok: there is no channel 295 UNUSED(size); // ok: handling own l2cap events 296 297 att_server_t * att_server; 298 att_connection_t * att_connection; 299 hci_con_handle_t con_handle; 300 hci_connection_t * hci_connection; 301 302 switch (packet_type) { 303 304 case HCI_EVENT_PACKET: 305 switch (hci_event_packet_get_type(packet)) { 306 case HCI_EVENT_META_GAP: 307 switch (hci_event_gap_meta_get_subevent_code(packet)) { 308 case GAP_SUBEVENT_LE_CONNECTION_COMPLETE: 309 con_handle = gap_subevent_le_connection_complete_get_connection_handle(packet); 310 hci_connection = hci_connection_for_handle(con_handle); 311 if (!hci_connection) break; 312 att_server = &hci_connection->att_server; 313 // store connection info 314 att_server->peer_addr_type = gap_subevent_le_connection_complete_get_peer_address_type(packet); 315 gap_subevent_le_connection_complete_get_peer_address(packet, att_server->peer_address); 316 att_connection = &hci_connection->att_connection; 317 att_connection->con_handle = con_handle; 318 // reset connection properties 319 att_server->state = ATT_SERVER_IDLE; 320 att_server->bearer_type = ATT_BEARER_UNENHANCED_LE; 321 att_connection->mtu = ATT_DEFAULT_MTU; 322 att_connection->max_mtu = l2cap_max_le_mtu(); 323 if (att_connection->max_mtu > ATT_REQUEST_BUFFER_SIZE){ 324 att_connection->max_mtu = ATT_REQUEST_BUFFER_SIZE; 325 } 326 att_connection->encryption_key_size = 0u; 327 att_connection->authenticated = 0u; 328 att_connection->authorized = 0u; 329 // workaround: identity resolving can already be complete, at least store result 330 att_server->ir_le_device_db_index = sm_le_device_index(con_handle); 331 att_server->ir_lookup_active = 0u; 332 att_server->pairing_active = 0u; 333 // notify all - old 334 att_emit_event_to_all(packet, size); 335 // notify all - new 336 att_emit_connected_event(att_server, att_connection); 337 break; 338 default: 339 break; 340 } 341 break; 342 343 case HCI_EVENT_ENCRYPTION_CHANGE: 344 case HCI_EVENT_ENCRYPTION_CHANGE_V2: 345 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 346 // check handle 347 con_handle = little_endian_read_16(packet, 3); 348 hci_connection = hci_connection_for_handle(con_handle); 349 if (!hci_connection) break; 350 if (gap_get_connection_type(con_handle) != GAP_CONNECTION_LE) break; 351 // update security params 352 att_server = &hci_connection->att_server; 353 att_connection = &hci_connection->att_connection; 354 att_connection->encryption_key_size = gap_encryption_key_size(con_handle); 355 att_connection->authenticated = gap_authenticated(con_handle) ? 1 : 0; 356 att_connection->secure_connection = gap_secure_connection(con_handle) ? 1 : 0; 357 log_info("encrypted key size %u, authenticated %u, secure connection %u", 358 att_connection->encryption_key_size, att_connection->authenticated, att_connection->secure_connection); 359 if (hci_event_packet_get_type(packet) == HCI_EVENT_ENCRYPTION_CHANGE){ 360 // restore CCC values when encrypted for LE Connections 361 if (hci_event_encryption_change_get_encryption_enabled(packet) != 0){ 362 att_server_persistent_ccc_restore(att_server, att_connection); 363 } 364 } 365 att_run_for_context(att_server, att_connection); 366 break; 367 368 case HCI_EVENT_DISCONNECTION_COMPLETE: 369 // check handle 370 con_handle = hci_event_disconnection_complete_get_connection_handle(packet); 371 hci_connection = hci_connection_for_handle(con_handle); 372 if (!hci_connection) break; 373 att_server = &hci_connection->att_server; 374 att_connection = &hci_connection->att_connection; 375 att_clear_transaction_queue(att_connection); 376 att_connection->con_handle = 0; 377 att_server->pairing_active = 0; 378 att_server->state = ATT_SERVER_IDLE; 379 if (att_server->value_indication_handle != 0u){ 380 btstack_run_loop_remove_timer(&att_server->value_indication_timer); 381 uint16_t att_handle = att_server->value_indication_handle; 382 att_server->value_indication_handle = 0u; // reset error state 383 att_handle_value_indication_notify_client((uint8_t)ATT_HANDLE_VALUE_INDICATION_DISCONNECT, att_connection->con_handle, att_handle); 384 } 385 // notify all - new 386 att_emit_disconnected_event(con_handle); 387 // notify all - old 388 att_emit_event_to_all(packet, size); 389 break; 390 391 // Identity Resolving 392 case SM_EVENT_IDENTITY_RESOLVING_STARTED: 393 con_handle = sm_event_identity_resolving_started_get_handle(packet); 394 hci_connection = hci_connection_for_handle(con_handle); 395 if (!hci_connection) break; 396 att_server = &hci_connection->att_server; 397 log_info("SM_EVENT_IDENTITY_RESOLVING_STARTED"); 398 att_server->ir_lookup_active = 1; 399 break; 400 case SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED: 401 con_handle = sm_event_identity_created_get_handle(packet); 402 hci_connection = hci_connection_for_handle(con_handle); 403 if (!hci_connection) return; 404 att_connection = &hci_connection->att_connection; 405 att_server = &hci_connection->att_server; 406 att_server->ir_lookup_active = 0; 407 att_server->ir_le_device_db_index = sm_event_identity_resolving_succeeded_get_index(packet); 408 log_info("SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED"); 409 att_run_for_context(att_server, att_connection); 410 break; 411 case SM_EVENT_IDENTITY_RESOLVING_FAILED: 412 con_handle = sm_event_identity_resolving_failed_get_handle(packet); 413 hci_connection = hci_connection_for_handle(con_handle); 414 if (!hci_connection) break; 415 att_connection = &hci_connection->att_connection; 416 att_server = &hci_connection->att_server; 417 log_info("SM_EVENT_IDENTITY_RESOLVING_FAILED"); 418 att_server->ir_lookup_active = 0; 419 att_server->ir_le_device_db_index = -1; 420 att_run_for_context(att_server, att_connection); 421 break; 422 423 // Pairing started - delete stored CCC values 424 // - assumes pairing indicates either new device or re-pairing, in both cases there should be no stored CCC values 425 // - assumes that all events have the con handle as the first field 426 case SM_EVENT_JUST_WORKS_REQUEST: 427 case SM_EVENT_PASSKEY_DISPLAY_NUMBER: 428 case SM_EVENT_PASSKEY_INPUT_NUMBER: 429 case SM_EVENT_NUMERIC_COMPARISON_REQUEST: 430 con_handle = sm_event_just_works_request_get_handle(packet); 431 hci_connection = hci_connection_for_handle(con_handle); 432 if (!hci_connection) break; 433 att_server = &hci_connection->att_server; 434 log_info("SM Pairing started"); 435 att_server->pairing_active = 1; 436 if (att_server->ir_le_device_db_index < 0) break; 437 att_server_persistent_ccc_clear(att_server); 438 // index not valid anymore 439 att_server->ir_le_device_db_index = -1; 440 break; 441 442 // Bonding completed 443 case SM_EVENT_IDENTITY_CREATED: 444 con_handle = sm_event_identity_created_get_handle(packet); 445 hci_connection = hci_connection_for_handle(con_handle); 446 if (!hci_connection) return; 447 att_connection = &hci_connection->att_connection; 448 att_server = &hci_connection->att_server; 449 att_server->pairing_active = 0; 450 att_server->ir_le_device_db_index = sm_event_identity_created_get_index(packet); 451 att_run_for_context(att_server, att_connection); 452 break; 453 454 // Pairing complete (with/without bonding=storing of pairing information) 455 case SM_EVENT_PAIRING_COMPLETE: 456 con_handle = sm_event_pairing_complete_get_handle(packet); 457 hci_connection = hci_connection_for_handle(con_handle); 458 if (!hci_connection) return; 459 att_connection = &hci_connection->att_connection; 460 att_server = &hci_connection->att_server; 461 att_server->pairing_active = 0; 462 att_run_for_context(att_server, att_connection); 463 break; 464 465 // Authorization 466 case SM_EVENT_AUTHORIZATION_RESULT: { 467 con_handle = sm_event_authorization_result_get_handle(packet); 468 hci_connection = hci_connection_for_handle(con_handle); 469 if (!hci_connection) break; 470 att_connection = &hci_connection->att_connection; 471 att_server = &hci_connection->att_server; 472 att_connection->authorized = sm_event_authorization_result_get_authorization_result(packet); 473 att_server_request_can_send_now(att_server, att_connection); 474 break; 475 } 476 default: 477 break; 478 } 479 break; 480 default: 481 break; 482 } 483 } 484 485 static uint8_t 486 att_server_send_prepared(const att_server_t *att_server, const att_connection_t *att_connection, uint8_t *buffer, 487 uint16_t size) { 488 uint8_t status = ERROR_CODE_SUCCESS; 489 switch (att_server->bearer_type) { 490 case ATT_BEARER_UNENHANCED_LE: 491 status = l2cap_send_prepared_connectionless(att_connection->con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, size); 492 break; 493 #ifdef ENABLE_GATT_OVER_CLASSIC 494 case ATT_BEARER_UNENHANCED_CLASSIC: 495 status = l2cap_send_prepared(att_server->l2cap_cid, size); 496 break; 497 #endif 498 #ifdef ENABLE_GATT_OVER_EATT 499 case ATT_BEARER_ENHANCED_LE: 500 btstack_assert(buffer != NULL); 501 status = l2cap_send(att_server->l2cap_cid, buffer, size); 502 break; 503 #endif 504 default: 505 btstack_unreachable(); 506 break; 507 } 508 return status; 509 } 510 511 #ifdef ENABLE_LE_SIGNED_WRITE 512 static void att_signed_write_handle_cmac_result(uint8_t hash[8]){ 513 att_server_t * att_server = NULL; 514 att_connection_t * att_connection = NULL; 515 bool found = att_server_connections_for_state(ATT_SERVER_W4_SIGNED_WRITE_VALIDATION, &att_server, &att_connection); 516 517 if (found == false){ 518 return; 519 } 520 521 uint8_t hash_flipped[8]; 522 reverse_64(hash, hash_flipped); 523 if (memcmp(hash_flipped, &att_server->request_buffer[att_server->request_size-8], 8) != 0){ 524 log_info("ATT Signed Write, invalid signature"); 525 #ifdef ENABLE_TESTING_SUPPORT 526 printf("ATT Signed Write, invalid signature\n"); 527 #endif 528 att_server->state = ATT_SERVER_IDLE; 529 return; 530 } 531 log_info("ATT Signed Write, valid signature"); 532 #ifdef ENABLE_TESTING_SUPPORT 533 printf("ATT Signed Write, valid signature\n"); 534 #endif 535 536 // update sequence number 537 uint32_t counter_packet = little_endian_read_32(att_server->request_buffer, att_server->request_size-12); 538 le_device_db_remote_counter_set(att_server->ir_le_device_db_index, counter_packet+1); 539 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 540 att_server_request_can_send_now(att_server, att_connection); 541 } 542 #endif 543 544 // pre: att_server->state == ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED 545 // pre: can send now 546 // uses l2cap outgoing buffer if no eatt_buffer provided 547 // returns: 1 if packet was sent 548 static int 549 att_server_process_validated_request(att_server_t *att_server, att_connection_t *att_connection, uint8_t *eatt_buffer) { 550 551 uint8_t * att_response_buffer; 552 if (eatt_buffer != NULL){ 553 att_response_buffer = eatt_buffer; 554 } else { 555 l2cap_reserve_packet_buffer(); 556 att_response_buffer = l2cap_get_outgoing_buffer(); 557 } 558 559 uint16_t att_response_size = 0; 560 // Send Error Response for MTU Request over connection-oriented channel 561 if ((att_server->bearer_type != ATT_BEARER_UNENHANCED_LE) && (att_server->request_buffer[0] == ATT_EXCHANGE_MTU_REQUEST)){ 562 att_response_size = 5; 563 att_response_buffer[0] = ATT_ERROR_RESPONSE; 564 att_response_buffer[1] = ATT_EXCHANGE_MTU_REQUEST; 565 att_response_buffer[2] = 0; 566 att_response_buffer[3] = 0; 567 att_response_buffer[4] = ATT_ERROR_REQUEST_NOT_SUPPORTED; 568 } else { 569 att_response_size = att_handle_request(att_connection, att_server->request_buffer, att_server->request_size, att_response_buffer); 570 } 571 572 #ifdef ENABLE_ATT_DELAYED_RESPONSE 573 if ((att_response_size == ATT_READ_RESPONSE_PENDING) || (att_response_size == ATT_INTERNAL_WRITE_RESPONSE_PENDING)){ 574 // update state 575 att_server->state = ATT_SERVER_RESPONSE_PENDING; 576 577 // callback with handle ATT_READ_RESPONSE_PENDING for reads 578 if (att_response_size == ATT_READ_RESPONSE_PENDING){ 579 att_server_client_read_callback(att_connection->con_handle, ATT_READ_RESPONSE_PENDING, 0, NULL, 0); 580 } 581 582 // free reserved buffer 583 if (eatt_buffer == NULL){ 584 l2cap_release_packet_buffer(); 585 } 586 return 0; 587 } 588 #endif 589 590 // intercept "insufficient authorization" for authenticated connections to allow for user authorization 591 if ((att_response_size >= 4u) 592 && (att_response_buffer[0] == ATT_ERROR_RESPONSE) 593 && (att_response_buffer[4] == ATT_ERROR_INSUFFICIENT_AUTHORIZATION) 594 && (att_connection->authenticated != 0u)){ 595 596 switch (gap_authorization_state(att_connection->con_handle)){ 597 case AUTHORIZATION_UNKNOWN: 598 if (eatt_buffer == NULL){ 599 l2cap_release_packet_buffer(); 600 } 601 sm_request_pairing(att_connection->con_handle); 602 return 0; 603 case AUTHORIZATION_PENDING: 604 if (eatt_buffer == NULL){ 605 l2cap_release_packet_buffer(); 606 } 607 return 0; 608 default: 609 break; 610 } 611 } 612 613 att_server->state = ATT_SERVER_IDLE; 614 if (att_response_size == 0u) { 615 if (eatt_buffer == NULL){ 616 l2cap_release_packet_buffer(); 617 } 618 return 0; 619 } 620 621 (void) att_server_send_prepared(att_server, att_connection, eatt_buffer, att_response_size); 622 623 // notify client about MTU exchange result 624 if (att_response_buffer[0] == ATT_EXCHANGE_MTU_RESPONSE){ 625 att_emit_mtu_event(att_connection->con_handle, att_connection->mtu); 626 } 627 return 1; 628 } 629 630 #ifdef ENABLE_ATT_DELAYED_RESPONSE 631 uint8_t att_server_response_ready(hci_con_handle_t con_handle){ 632 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 633 if (!hci_connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 634 att_server_t * att_server = &hci_connection->att_server; 635 att_connection_t * att_connection = &hci_connection->att_connection; 636 if (att_server->state != ATT_SERVER_RESPONSE_PENDING) return ERROR_CODE_COMMAND_DISALLOWED; 637 638 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 639 att_server_request_can_send_now(att_server, att_connection); 640 return ERROR_CODE_SUCCESS; 641 } 642 #endif 643 644 static void att_run_for_context(att_server_t * att_server, att_connection_t * att_connection){ 645 switch (att_server->state){ 646 case ATT_SERVER_REQUEST_RECEIVED: 647 switch (att_server->bearer_type){ 648 case ATT_BEARER_UNENHANCED_LE: 649 // wait until re-encryption as central is complete 650 if (gap_reconnect_security_setup_active(att_connection->con_handle)) { 651 return; 652 }; 653 break; 654 #if defined(ENABLE_GATT_OVER_CLASSIC) || defined (ENABLE_GATT_OVER_EATT) 655 #ifdef ENABLE_GATT_OVER_CLASSIC 656 case ATT_BEARER_UNENHANCED_CLASSIC: 657 /* fall through */ 658 #endif 659 #ifdef ENABLE_GATT_OVER_EATT 660 case ATT_BEARER_ENHANCED_LE: 661 #endif 662 // ok 663 break; 664 #endif 665 default: 666 btstack_unreachable(); 667 break; 668 } 669 670 // wait until pairing is complete 671 if (att_server->pairing_active) break; 672 673 #ifdef ENABLE_LE_SIGNED_WRITE 674 if (att_server->request_buffer[0] == ATT_SIGNED_WRITE_COMMAND){ 675 log_info("ATT Signed Write!"); 676 if (!sm_cmac_ready()) { 677 log_info("ATT Signed Write, sm_cmac engine not ready. Abort"); 678 att_server->state = ATT_SERVER_IDLE; 679 return; 680 } 681 if (att_server->request_size < (3 + 12)) { 682 log_info("ATT Signed Write, request to short. Abort."); 683 att_server->state = ATT_SERVER_IDLE; 684 return; 685 } 686 if (att_server->ir_lookup_active){ 687 return; 688 } 689 if (att_server->ir_le_device_db_index < 0){ 690 log_info("ATT Signed Write, CSRK not available"); 691 att_server->state = ATT_SERVER_IDLE; 692 return; 693 } 694 695 // check counter 696 uint32_t counter_packet = little_endian_read_32(att_server->request_buffer, att_server->request_size-12); 697 uint32_t counter_db = le_device_db_remote_counter_get(att_server->ir_le_device_db_index); 698 log_info("ATT Signed Write, DB counter %"PRIu32", packet counter %"PRIu32, counter_db, counter_packet); 699 if (counter_packet < counter_db){ 700 log_info("ATT Signed Write, db reports higher counter, abort"); 701 att_server->state = ATT_SERVER_IDLE; 702 return; 703 } 704 705 // signature is { sequence counter, secure hash } 706 sm_key_t csrk; 707 le_device_db_remote_csrk_get(att_server->ir_le_device_db_index, csrk); 708 att_server->state = ATT_SERVER_W4_SIGNED_WRITE_VALIDATION; 709 log_info("Orig Signature: "); 710 log_info_hexdump( &att_server->request_buffer[att_server->request_size-8], 8); 711 uint16_t attribute_handle = little_endian_read_16(att_server->request_buffer, 1); 712 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); 713 return; 714 } 715 #endif 716 // move on 717 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 718 att_server_request_can_send_now(att_server, att_connection); 719 break; 720 721 default: 722 break; 723 } 724 } 725 726 static bool att_server_data_ready_for_phase(att_server_t * att_server, att_server_run_phase_t phase){ 727 switch (phase){ 728 case ATT_SERVER_RUN_PHASE_1_REQUESTS: 729 return att_server->state == ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 730 case ATT_SERVER_RUN_PHASE_2_INDICATIONS: 731 return (!btstack_linked_list_empty(&att_server->indication_requests) && (att_server->value_indication_handle == 0u)); 732 case ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS: 733 return (!btstack_linked_list_empty(&att_server->notification_requests)); 734 default: 735 btstack_assert(false); 736 return false; 737 } 738 } 739 740 static void att_server_trigger_send_for_phase(att_server_t * att_server, att_connection_t * att_connection, att_server_run_phase_t phase){ 741 btstack_context_callback_registration_t * client; 742 switch (phase){ 743 case ATT_SERVER_RUN_PHASE_1_REQUESTS: 744 att_server_process_validated_request(att_server, att_connection, NULL); 745 break; 746 case ATT_SERVER_RUN_PHASE_2_INDICATIONS: 747 client = (btstack_context_callback_registration_t*) att_server->indication_requests; 748 btstack_linked_list_remove(&att_server->indication_requests, (btstack_linked_item_t *) client); 749 client->callback(client->context); 750 break; 751 case ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS: 752 client = (btstack_context_callback_registration_t*) att_server->notification_requests; 753 btstack_linked_list_remove(&att_server->notification_requests, (btstack_linked_item_t *) client); 754 client->callback(client->context); 755 break; 756 default: 757 btstack_assert(false); 758 break; 759 } 760 } 761 762 static void att_server_handle_can_send_now(void){ 763 764 hci_con_handle_t last_send_con_handle = HCI_CON_HANDLE_INVALID; 765 hci_connection_t * request_hci_connection = NULL; 766 bool can_send_now = true; 767 uint8_t phase_index; 768 769 for (phase_index = ATT_SERVER_RUN_PHASE_1_REQUESTS; phase_index <= ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS; phase_index++){ 770 att_server_run_phase_t phase = (att_server_run_phase_t) phase_index; 771 hci_con_handle_t skip_connections_until = att_server_last_can_send_now; 772 while (true){ 773 btstack_linked_list_iterator_t it; 774 hci_connections_get_iterator(&it); 775 while(btstack_linked_list_iterator_has_next(&it)){ 776 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 777 att_server_t * att_server = &connection->att_server; 778 att_connection_t * att_connection = &connection->att_connection; 779 780 bool data_ready = att_server_data_ready_for_phase(att_server, phase); 781 782 // log_debug("phase %u, handle 0x%04x, skip until 0x%04x, data ready %u", phase, att_connection->con_handle, skip_connections_until, data_ready); 783 784 // skip until last sender found (which is also skipped) 785 if (skip_connections_until != HCI_CON_HANDLE_INVALID){ 786 if (data_ready && (request_hci_connection == NULL)){ 787 request_hci_connection = connection; 788 } 789 if (skip_connections_until == att_connection->con_handle){ 790 skip_connections_until = HCI_CON_HANDLE_INVALID; 791 } 792 continue; 793 }; 794 795 if (data_ready){ 796 if (can_send_now){ 797 att_server_trigger_send_for_phase(att_server, att_connection, phase); 798 last_send_con_handle = att_connection->con_handle; 799 can_send_now = att_server_can_send_packet(att_server, att_connection); 800 data_ready = att_server_data_ready_for_phase(att_server, phase); 801 if (data_ready && (request_hci_connection == NULL)){ 802 request_hci_connection = connection; 803 } 804 } else { 805 request_hci_connection = connection; 806 break; 807 } 808 } 809 } 810 811 // stop skipping (handles disconnect by last send connection) 812 skip_connections_until = HCI_CON_HANDLE_INVALID; 813 814 // Exit loop, if we cannot send 815 if (!can_send_now) break; 816 817 // Exit loop, if we can send but there are also no further request 818 if (request_hci_connection == NULL) break; 819 820 // Finally, if we still can send and there are requests, just try again 821 request_hci_connection = NULL; 822 } 823 // update last send con handle for round robin 824 if (last_send_con_handle != HCI_CON_HANDLE_INVALID){ 825 att_server_last_can_send_now = last_send_con_handle; 826 } 827 } 828 829 if (request_hci_connection == NULL) return; 830 831 att_server_t * att_server = &request_hci_connection->att_server; 832 att_connection_t * att_connection = &request_hci_connection->att_connection; 833 att_server_request_can_send_now(att_server, att_connection); 834 } 835 836 static void att_server_handle_att_pdu(att_server_t * att_server, att_connection_t * att_connection, uint8_t * packet, uint16_t size){ 837 838 uint8_t opcode = packet[0u]; 839 uint8_t method = opcode & 0x03fu; 840 bool invalid = method > ATT_MULTIPLE_HANDLE_VALUE_NTF; 841 bool command = (opcode & 0x40u) != 0u; 842 843 // ignore invalid commands 844 if (invalid && command){ 845 return; 846 } 847 848 // handle value indication confirms 849 if ((opcode == ATT_HANDLE_VALUE_CONFIRMATION) && (att_server->value_indication_handle != 0u)){ 850 btstack_run_loop_remove_timer(&att_server->value_indication_timer); 851 uint16_t att_handle = att_server->value_indication_handle; 852 att_server->value_indication_handle = 0u; 853 att_handle_value_indication_notify_client(0u, att_connection->con_handle, att_handle); 854 att_server_request_can_send_now(att_server, att_connection); 855 return; 856 } 857 858 // directly process command 859 // note: signed write cannot be handled directly as authentication needs to be verified 860 if (opcode == ATT_WRITE_COMMAND){ 861 att_handle_request(att_connection, packet, size, NULL); 862 return; 863 } 864 865 // check size 866 if (size > sizeof(att_server->request_buffer)) { 867 log_info("drop att pdu 0x%02x as size %u > att_server->request_buffer %u", packet[0], size, (int) sizeof(att_server->request_buffer)); 868 return; 869 } 870 871 #ifdef ENABLE_LE_SIGNED_WRITE 872 // abort signed write validation if a new request comes in (but finish previous signed write if possible) 873 if (att_server->state == ATT_SERVER_W4_SIGNED_WRITE_VALIDATION){ 874 if (packet[0] == ATT_SIGNED_WRITE_COMMAND){ 875 log_info("skip new signed write request as previous is in validation"); 876 return; 877 } else { 878 log_info("abort signed write validation to process new request"); 879 att_server->state = ATT_SERVER_IDLE; 880 } 881 } 882 #endif 883 // last request still in processing? 884 if (att_server->state != ATT_SERVER_IDLE){ 885 log_info("skip att pdu 0x%02x as server not idle (state %u)", packet[0], att_server->state); 886 return; 887 } 888 889 // store request 890 att_server->state = ATT_SERVER_REQUEST_RECEIVED; 891 att_server->request_size = size; 892 (void)memcpy(att_server->request_buffer, packet, size); 893 894 att_run_for_context(att_server, att_connection); 895 } 896 897 static void att_server_dispatch_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 898 hci_connection_t * hci_connection; 899 att_connection_t * att_connection; 900 att_server_t * att_server; 901 #ifdef ENABLE_GATT_OVER_CLASSIC 902 hci_con_handle_t con_handle; 903 bd_addr_t address; 904 btstack_linked_list_iterator_t it; 905 #endif 906 907 switch (packet_type){ 908 case HCI_EVENT_PACKET: 909 switch (packet[0]){ 910 #ifdef ENABLE_GATT_OVER_CLASSIC 911 case L2CAP_EVENT_CHANNEL_OPENED: 912 con_handle = l2cap_event_channel_opened_get_handle(packet); 913 hci_connection = hci_connection_for_handle(con_handle); 914 if (!hci_connection) break; 915 att_server = &hci_connection->att_server; 916 // store connection info 917 att_server->bearer_type = ATT_BEARER_UNENHANCED_CLASSIC; 918 att_server->peer_addr_type = BD_ADDR_TYPE_ACL; 919 l2cap_event_channel_opened_get_address(packet, att_server->peer_address); 920 att_connection = &hci_connection->att_connection; 921 att_connection->con_handle = con_handle; 922 // reset connection properties 923 att_server->state = ATT_SERVER_IDLE; 924 att_connection->mtu = l2cap_event_channel_opened_get_remote_mtu(packet); 925 att_connection->max_mtu = l2cap_max_mtu(); 926 if (att_connection->max_mtu > ATT_REQUEST_BUFFER_SIZE){ 927 att_connection->max_mtu = ATT_REQUEST_BUFFER_SIZE; 928 } 929 930 log_info("Connection opened %s, l2cap cid %04x, mtu %u", bd_addr_to_str(address), att_server->l2cap_cid, att_connection->mtu); 931 932 // update security params 933 att_connection->encryption_key_size = gap_encryption_key_size(con_handle); 934 att_connection->authenticated = gap_authenticated(con_handle); 935 att_connection->secure_connection = gap_secure_connection(con_handle); 936 log_info("encrypted key size %u, authenticated %u, secure connection %u", 937 att_connection->encryption_key_size, att_connection->authenticated, att_connection->secure_connection); 938 939 // notify connection opened 940 att_emit_connected_event(att_server, att_connection); 941 942 // restore persisten ccc if encrypted 943 if ( gap_security_level(con_handle) >= LEVEL_2){ 944 att_server_persistent_ccc_restore(att_server, att_connection); 945 } 946 // TODO: what to do about le device db? 947 att_server->pairing_active = 0; 948 break; 949 #endif 950 case L2CAP_EVENT_CAN_SEND_NOW: 951 att_server_handle_can_send_now(); 952 break; 953 case ATT_EVENT_MTU_EXCHANGE_COMPLETE: 954 // GATT client has negotiated the mtu for this connection 955 hci_connection = hci_connection_for_handle(channel); 956 if (!hci_connection) break; 957 att_connection = &hci_connection->att_connection; 958 att_connection->mtu = little_endian_read_16(packet, 4); 959 break; 960 default: 961 break; 962 } 963 break; 964 965 case ATT_DATA_PACKET: 966 log_debug("ATT Packet, handle 0x%04x", channel); 967 hci_connection = hci_connection_for_handle(channel); 968 if (!hci_connection) break; 969 970 att_server = &hci_connection->att_server; 971 att_connection = &hci_connection->att_connection; 972 att_server_handle_att_pdu(att_server, att_connection, packet, size); 973 break; 974 975 #ifdef ENABLE_GATT_OVER_CLASSIC 976 case L2CAP_DATA_PACKET: 977 hci_connections_get_iterator(&it); 978 while(btstack_linked_list_iterator_has_next(&it)){ 979 hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 980 att_server = &hci_connection->att_server; 981 att_connection = &hci_connection->att_connection; 982 if (att_server->l2cap_cid == channel) { 983 att_server_handle_att_pdu(att_server, att_connection, packet, size); 984 break; 985 } 986 } 987 break; 988 #endif 989 990 default: 991 break; 992 } 993 } 994 995 // --------------------- 996 // persistent CCC writes 997 static uint32_t att_server_persistent_ccc_tag_for_index(uint8_t index){ 998 return ('B' << 24u) | ('T' << 16u) | ('C' << 8u) | index; 999 } 1000 1001 static void att_server_persistent_ccc_write(hci_con_handle_t con_handle, uint16_t att_handle, uint16_t value){ 1002 // lookup att_server instance 1003 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 1004 if (!hci_connection) return; 1005 att_server_t * att_server = &hci_connection->att_server; 1006 int le_device_index = att_server->ir_le_device_db_index; 1007 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); 1008 1009 // check if bonded 1010 if (le_device_index < 0) return; 1011 1012 // get btstack_tlv 1013 const btstack_tlv_t * tlv_impl = NULL; 1014 void * tlv_context; 1015 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 1016 if (!tlv_impl) return; 1017 1018 // update ccc tag 1019 int index; 1020 uint32_t highest_seq_nr = 0; 1021 uint32_t lowest_seq_nr = 0; 1022 uint32_t tag_for_lowest_seq_nr = 0; 1023 uint32_t tag_for_empty = 0; 1024 persistent_ccc_entry_t entry; 1025 for (index=0; index<NVN_NUM_GATT_SERVER_CCC; index++){ 1026 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 1027 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 1028 1029 // empty/invalid tag 1030 if (len != sizeof(persistent_ccc_entry_t)){ 1031 tag_for_empty = tag; 1032 continue; 1033 } 1034 // update highest seq nr 1035 if (entry.seq_nr > highest_seq_nr){ 1036 highest_seq_nr = entry.seq_nr; 1037 } 1038 // find entry with lowest seq nr 1039 if ((tag_for_lowest_seq_nr == 0u) || (entry.seq_nr < lowest_seq_nr)){ 1040 tag_for_lowest_seq_nr = tag; 1041 lowest_seq_nr = entry.seq_nr; 1042 } 1043 1044 if (entry.device_index != le_device_index) continue; 1045 if (entry.att_handle != att_handle) continue; 1046 1047 // found matching entry 1048 if (value != 0){ 1049 // update 1050 if (entry.value == value) { 1051 log_info("CCC Index %u: Up-to-date", index); 1052 return; 1053 } 1054 entry.value = (uint8_t) value; 1055 entry.seq_nr = highest_seq_nr + 1u; 1056 log_info("CCC Index %u: Store", index); 1057 int result = tlv_impl->store_tag(tlv_context, tag, (const uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 1058 if (result != 0){ 1059 log_error("Store tag index %u failed", index); 1060 } 1061 } else { 1062 // delete 1063 log_info("CCC Index %u: Delete", index); 1064 tlv_impl->delete_tag(tlv_context, tag); 1065 } 1066 return; 1067 } 1068 1069 log_info("tag_for_empty %"PRIx32", tag_for_lowest_seq_nr %"PRIx32, tag_for_empty, tag_for_lowest_seq_nr); 1070 1071 if (value == 0u){ 1072 // done 1073 return; 1074 } 1075 1076 uint32_t tag_to_use = 0u; 1077 if (tag_for_empty != 0u){ 1078 tag_to_use = tag_for_empty; 1079 } else if (tag_for_lowest_seq_nr){ 1080 tag_to_use = tag_for_lowest_seq_nr; 1081 } else { 1082 // should not happen 1083 return; 1084 } 1085 // store ccc tag 1086 entry.seq_nr = highest_seq_nr + 1u; 1087 entry.device_index = le_device_index; 1088 entry.att_handle = att_handle; 1089 entry.value = (uint8_t) value; 1090 int result = tlv_impl->store_tag(tlv_context, tag_to_use, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 1091 if (result != 0){ 1092 log_error("Store tag index %u failed", index); 1093 } 1094 } 1095 1096 static void att_server_persistent_ccc_clear(att_server_t * att_server){ 1097 int le_device_index = att_server->ir_le_device_db_index; 1098 log_info("Clear CCC values of remote %s, le device id %d", bd_addr_to_str(att_server->peer_address), le_device_index); 1099 // check if bonded 1100 if (le_device_index < 0) return; 1101 // get btstack_tlv 1102 const btstack_tlv_t * tlv_impl = NULL; 1103 void * tlv_context; 1104 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 1105 if (!tlv_impl) return; 1106 // get all ccc tag 1107 int index; 1108 persistent_ccc_entry_t entry; 1109 for (index=0;index<NVN_NUM_GATT_SERVER_CCC;index++){ 1110 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 1111 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 1112 if (len != sizeof(persistent_ccc_entry_t)) continue; 1113 if (entry.device_index != le_device_index) continue; 1114 // delete entry 1115 log_info("CCC Index %u: Delete", index); 1116 tlv_impl->delete_tag(tlv_context, tag); 1117 } 1118 } 1119 1120 static void att_server_persistent_ccc_restore(att_server_t * att_server, att_connection_t * att_connection){ 1121 int le_device_index = att_server->ir_le_device_db_index; 1122 log_info("Restore CCC values of remote %s, le device id %d", bd_addr_to_str(att_server->peer_address), le_device_index); 1123 // check if bonded 1124 if (le_device_index < 0) return; 1125 // get btstack_tlv 1126 const btstack_tlv_t * tlv_impl = NULL; 1127 void * tlv_context; 1128 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 1129 if (!tlv_impl) return; 1130 // get all ccc tag 1131 int index; 1132 persistent_ccc_entry_t entry; 1133 for (index=0;index<NVN_NUM_GATT_SERVER_CCC;index++){ 1134 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 1135 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 1136 if (len != sizeof(persistent_ccc_entry_t)) continue; 1137 if (entry.device_index != le_device_index) continue; 1138 // simulate write callback 1139 uint16_t attribute_handle = entry.att_handle; 1140 uint8_t value[2]; 1141 little_endian_store_16(value, 0, entry.value); 1142 att_write_callback_t callback = att_server_write_callback_for_handle(attribute_handle); 1143 if (!callback) continue; 1144 log_info("CCC Index %u: Set Attribute handle 0x%04x to value 0x%04x", index, attribute_handle, entry.value ); 1145 (*callback)(att_connection->con_handle, attribute_handle, ATT_TRANSACTION_MODE_NONE, 0, value, sizeof(value)); 1146 } 1147 } 1148 1149 // persistent CCC writes 1150 // --------------------- 1151 1152 // gatt service management 1153 static att_service_handler_t * att_service_handler_for_handle(uint16_t handle){ 1154 btstack_linked_list_iterator_t it; 1155 btstack_linked_list_iterator_init(&it, &service_handlers); 1156 while (btstack_linked_list_iterator_has_next(&it)){ 1157 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 1158 if (handler->start_handle > handle) continue; 1159 if (handler->end_handle < handle) continue; 1160 return handler; 1161 } 1162 return NULL; 1163 } 1164 static att_read_callback_t att_server_read_callback_for_handle(uint16_t handle){ 1165 att_service_handler_t * handler = att_service_handler_for_handle(handle); 1166 if (handler != NULL) return handler->read_callback; 1167 return att_server_client_read_callback; 1168 } 1169 1170 static att_write_callback_t att_server_write_callback_for_handle(uint16_t handle){ 1171 att_service_handler_t * handler = att_service_handler_for_handle(handle); 1172 if (handler != NULL) return handler->write_callback; 1173 return att_server_client_write_callback; 1174 } 1175 1176 static btstack_packet_handler_t att_server_packet_handler_for_handle(uint16_t handle){ 1177 att_service_handler_t * handler = att_service_handler_for_handle(handle); 1178 if (handler != NULL) return handler->packet_handler; 1179 return att_client_packet_handler; 1180 } 1181 1182 static void att_notify_write_callbacks(hci_con_handle_t con_handle, uint16_t transaction_mode){ 1183 // notify all callbacks 1184 btstack_linked_list_iterator_t it; 1185 btstack_linked_list_iterator_init(&it, &service_handlers); 1186 while (btstack_linked_list_iterator_has_next(&it)){ 1187 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 1188 if (!handler->write_callback) continue; 1189 (*handler->write_callback)(con_handle, 0, transaction_mode, 0, NULL, 0); 1190 } 1191 if (!att_server_client_write_callback) return; 1192 (*att_server_client_write_callback)(con_handle, 0, transaction_mode, 0, NULL, 0); 1193 } 1194 1195 // returns first reported error or 0 1196 static uint8_t att_validate_prepared_write(hci_con_handle_t con_handle){ 1197 btstack_linked_list_iterator_t it; 1198 btstack_linked_list_iterator_init(&it, &service_handlers); 1199 while (btstack_linked_list_iterator_has_next(&it)){ 1200 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 1201 if (!handler->write_callback) continue; 1202 uint8_t error_code = (*handler->write_callback)(con_handle, 0, ATT_TRANSACTION_MODE_VALIDATE, 0, NULL, 0); 1203 if (error_code != 0u) return error_code; 1204 } 1205 if (!att_server_client_write_callback) return 0; 1206 return (*att_server_client_write_callback)(con_handle, 0, ATT_TRANSACTION_MODE_VALIDATE, 0, NULL, 0); 1207 } 1208 1209 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){ 1210 att_read_callback_t callback = att_server_read_callback_for_handle(attribute_handle); 1211 if (!callback) return 0; 1212 return (*callback)(con_handle, attribute_handle, offset, buffer, buffer_size); 1213 } 1214 1215 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){ 1216 switch (transaction_mode){ 1217 case ATT_TRANSACTION_MODE_VALIDATE: 1218 return att_validate_prepared_write(con_handle); 1219 case ATT_TRANSACTION_MODE_EXECUTE: 1220 case ATT_TRANSACTION_MODE_CANCEL: 1221 att_notify_write_callbacks(con_handle, transaction_mode); 1222 return 0; 1223 default: 1224 break; 1225 } 1226 1227 // track CCC writes 1228 if (att_is_persistent_ccc(attribute_handle) && (offset == 0u) && (buffer_size == 2u)){ 1229 att_server_persistent_ccc_write(con_handle, attribute_handle, little_endian_read_16(buffer, 0)); 1230 } 1231 1232 att_write_callback_t callback = att_server_write_callback_for_handle(attribute_handle); 1233 if (!callback) return 0; 1234 return (*callback)(con_handle, attribute_handle, transaction_mode, offset, buffer, buffer_size); 1235 } 1236 1237 /** 1238 * @brief register read/write callbacks for specific handle range 1239 * @param att_service_handler_t 1240 */ 1241 void att_server_register_service_handler(att_service_handler_t * handler){ 1242 bool att_server_registered = false; 1243 if (att_service_handler_for_handle(handler->start_handle)){ 1244 att_server_registered = true; 1245 } 1246 1247 if (att_service_handler_for_handle(handler->end_handle)){ 1248 att_server_registered = true; 1249 } 1250 1251 if (att_server_registered){ 1252 log_error("handler for range 0x%04x-0x%04x already registered", handler->start_handle, handler->end_handle); 1253 return; 1254 } 1255 btstack_linked_list_add(&service_handlers, (btstack_linked_item_t*) handler); 1256 } 1257 1258 void att_server_init(uint8_t const * db, att_read_callback_t read_callback, att_write_callback_t write_callback){ 1259 1260 // store callbacks 1261 att_server_client_read_callback = read_callback; 1262 att_server_client_write_callback = write_callback; 1263 1264 // register for HCI Events 1265 hci_event_callback_registration.callback = &att_server_event_packet_handler; 1266 hci_add_event_handler(&hci_event_callback_registration); 1267 1268 // register for SM events 1269 sm_event_callback_registration.callback = &att_server_event_packet_handler; 1270 sm_add_event_handler(&sm_event_callback_registration); 1271 1272 // and L2CAP ATT Server PDUs 1273 att_dispatch_register_server(att_server_dispatch_packet_handler); 1274 1275 #ifdef ENABLE_GATT_OVER_CLASSIC 1276 // setup l2cap service 1277 att_dispatch_classic_register_service(); 1278 #endif 1279 1280 att_set_db(db); 1281 att_set_read_callback(att_server_read_callback); 1282 att_set_write_callback(att_server_write_callback); 1283 } 1284 1285 void att_server_register_packet_handler(btstack_packet_handler_t handler){ 1286 att_client_packet_handler = handler; 1287 } 1288 1289 1290 // to be deprecated 1291 int att_server_can_send_packet_now(hci_con_handle_t con_handle){ 1292 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 1293 if (!hci_connection) return 0; 1294 att_server_t * att_server = &hci_connection->att_server; 1295 att_connection_t * att_connection = &hci_connection->att_connection; 1296 return att_server_can_send_packet(att_server, att_connection); 1297 } 1298 1299 uint8_t att_server_register_can_send_now_callback(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 1300 return att_server_request_to_send_notification(callback_registration, con_handle); 1301 } 1302 1303 void att_server_request_can_send_now_event(hci_con_handle_t con_handle){ 1304 att_client_waiting_for_can_send_registration.callback = &att_emit_can_send_now_event; 1305 att_server_request_to_send_notification(&att_client_waiting_for_can_send_registration, con_handle); 1306 } 1307 // end of deprecated 1308 1309 uint8_t att_server_request_to_send_notification(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 1310 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 1311 if (!hci_connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1312 att_server_t * att_server = &hci_connection->att_server; 1313 att_connection_t * att_connection = &hci_connection->att_connection; 1314 bool added = btstack_linked_list_add_tail(&att_server->notification_requests, (btstack_linked_item_t*) callback_registration); 1315 att_server_request_can_send_now(att_server, att_connection); 1316 if (added){ 1317 return ERROR_CODE_SUCCESS; 1318 } else { 1319 return ERROR_CODE_COMMAND_DISALLOWED; 1320 } 1321 } 1322 1323 uint8_t att_server_request_to_send_indication(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 1324 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 1325 if (!hci_connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1326 att_server_t * att_server = &hci_connection->att_server; 1327 att_connection_t * att_connection = &hci_connection->att_connection; 1328 bool added = btstack_linked_list_add_tail(&att_server->indication_requests, (btstack_linked_item_t*) callback_registration); 1329 att_server_request_can_send_now(att_server, att_connection); 1330 if (added){ 1331 return ERROR_CODE_SUCCESS; 1332 } else { 1333 return ERROR_CODE_COMMAND_DISALLOWED; 1334 } 1335 } 1336 1337 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){ 1338 1339 att_server_t * att_server = NULL; 1340 att_connection_t * att_connection = NULL; 1341 uint8_t * packet_buffer = NULL; 1342 1343 // prefer enhanced bearer 1344 #ifdef ENABLE_GATT_OVER_EATT 1345 att_server_eatt_bearer_t * eatt_bearer = att_server_eatt_bearer_for_con_handle(con_handle); 1346 if (eatt_bearer != NULL){ 1347 att_server = &eatt_bearer->att_server; 1348 att_connection = &eatt_bearer->att_connection; 1349 packet_buffer = eatt_bearer->send_buffer; 1350 } else 1351 #endif 1352 { 1353 hci_connection_t *hci_connection = hci_connection_for_handle(con_handle); 1354 if (hci_connection != NULL) { 1355 att_server = &hci_connection->att_server; 1356 att_connection = &hci_connection->att_connection; 1357 } 1358 } 1359 1360 if (att_server == NULL) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1361 if (!att_server_can_send_packet(att_server, att_connection)) return BTSTACK_ACL_BUFFERS_FULL; 1362 1363 if (packet_buffer == NULL){ 1364 l2cap_reserve_packet_buffer(); 1365 packet_buffer = l2cap_get_outgoing_buffer(); 1366 } 1367 1368 *out_att_connection = att_connection; 1369 *out_att_server = att_server; 1370 *out_packet_buffer = packet_buffer; 1371 return ERROR_CODE_SUCCESS; 1372 } 1373 1374 uint8_t att_server_notify(hci_con_handle_t con_handle, uint16_t attribute_handle, const uint8_t *value, uint16_t value_len){ 1375 att_server_t * att_server = NULL; 1376 att_connection_t * att_connection = NULL; 1377 uint8_t * packet_buffer = NULL; 1378 1379 uint8_t status = att_server_prepare_server_message(con_handle, &att_server, &att_connection, &packet_buffer); 1380 if (status != ERROR_CODE_SUCCESS){ 1381 return status; 1382 } 1383 1384 uint16_t size = att_prepare_handle_value_notification(att_connection, attribute_handle, value, value_len, packet_buffer); 1385 1386 return att_server_send_prepared(att_server, att_connection, NULL, size); 1387 } 1388 1389 /** 1390 * @brief notify client about multiple attribute value changes 1391 * @param con_handle 1392 * @param num_attributes 1393 * @param attribute_handles[] 1394 * @param values_data[] 1395 * @param values_len[] 1396 * @return 0 if ok, error otherwise 1397 */ 1398 uint8_t att_server_multiple_notify(hci_con_handle_t con_handle, uint8_t num_attributes, 1399 const uint16_t * attribute_handles, const uint8_t ** values_data, const uint16_t * values_len){ 1400 1401 att_server_t * att_server = NULL; 1402 att_connection_t * att_connection = NULL; 1403 uint8_t * packet_buffer = NULL; 1404 1405 uint8_t status = att_server_prepare_server_message(con_handle, &att_server, &att_connection, &packet_buffer); 1406 if (status != ERROR_CODE_SUCCESS){ 1407 return status; 1408 } 1409 1410 uint16_t size = att_prepare_handle_value_multiple_notification(att_connection, num_attributes, attribute_handles, values_data, values_len, packet_buffer); 1411 1412 return att_server_send_prepared(att_server, att_connection, packet_buffer, size); 1413 } 1414 1415 uint8_t att_server_indicate(hci_con_handle_t con_handle, uint16_t attribute_handle, const uint8_t *value, uint16_t value_len){ 1416 1417 att_server_t * att_server = NULL; 1418 att_connection_t * att_connection = NULL; 1419 uint8_t * packet_buffer = NULL; 1420 1421 uint8_t status = att_server_prepare_server_message(con_handle, &att_server, &att_connection, &packet_buffer); 1422 if (status != ERROR_CODE_SUCCESS){ 1423 return status; 1424 } 1425 1426 if (att_server->value_indication_handle != 0u) { 1427 // free reserved packet buffer 1428 if (att_server->bearer_type == ATT_BEARER_ENHANCED_LE){ 1429 l2cap_release_packet_buffer(); 1430 } 1431 return ATT_HANDLE_VALUE_INDICATION_IN_PROGRESS; 1432 } 1433 1434 // track indication 1435 att_server->value_indication_handle = attribute_handle; 1436 btstack_run_loop_set_timer_handler(&att_server->value_indication_timer, att_handle_value_indication_timeout); 1437 btstack_run_loop_set_timer(&att_server->value_indication_timer, ATT_TRANSACTION_TIMEOUT_MS); 1438 btstack_run_loop_add_timer(&att_server->value_indication_timer); 1439 1440 uint16_t size = att_prepare_handle_value_indication(att_connection, attribute_handle, value, value_len, packet_buffer); 1441 1442 return att_server_send_prepared(att_server, att_connection, NULL, size); 1443 } 1444 1445 uint16_t att_server_get_mtu(hci_con_handle_t con_handle){ 1446 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 1447 if (!hci_connection) return 0; 1448 att_connection_t * att_connection = &hci_connection->att_connection; 1449 return att_connection->mtu; 1450 } 1451 1452 void att_server_deinit(void){ 1453 att_server_client_read_callback = NULL; 1454 att_server_client_write_callback = NULL; 1455 att_client_packet_handler = NULL; 1456 service_handlers = NULL; 1457 } 1458 1459 #ifdef ENABLE_GATT_OVER_EATT 1460 1461 #define MAX_NR_EATT_CHANNELS 5 1462 1463 static uint16_t att_server_eatt_receive_buffer_size; 1464 static uint16_t att_server_eatt_send_buffer_size; 1465 1466 static att_server_eatt_bearer_t * att_server_eatt_bearer_for_cid(uint16_t cid){ 1467 btstack_linked_list_iterator_t it; 1468 btstack_linked_list_iterator_init(&it, &att_server_eatt_bearer_active); 1469 while(btstack_linked_list_iterator_has_next(&it)){ 1470 att_server_eatt_bearer_t * eatt_bearer = (att_server_eatt_bearer_t *) btstack_linked_list_iterator_next(&it); 1471 if (eatt_bearer->att_server.l2cap_cid == cid) { 1472 return eatt_bearer; 1473 } 1474 } 1475 return NULL; 1476 } 1477 1478 static att_server_eatt_bearer_t * att_server_eatt_bearer_for_con_handle(hci_con_handle_t con_handle){ 1479 btstack_linked_list_iterator_t it; 1480 btstack_linked_list_iterator_init(&it, &att_server_eatt_bearer_active); 1481 while(btstack_linked_list_iterator_has_next(&it)){ 1482 att_server_eatt_bearer_t * eatt_bearer = (att_server_eatt_bearer_t *) btstack_linked_list_iterator_next(&it); 1483 if (eatt_bearer->att_connection.con_handle == con_handle) { 1484 return eatt_bearer; 1485 } 1486 } 1487 return NULL; 1488 } 1489 1490 static void att_server_eatt_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 1491 uint16_t cid; 1492 uint8_t status; 1493 uint16_t remote_mtu; 1494 1495 uint8_t i; 1496 uint8_t num_requested_bearers; 1497 uint8_t num_accepted_bearers; 1498 uint16_t initial_credits = L2CAP_LE_AUTOMATIC_CREDITS; 1499 uint8_t * receive_buffers[MAX_NR_EATT_CHANNELS]; 1500 uint16_t cids[MAX_NR_EATT_CHANNELS]; 1501 att_server_eatt_bearer_t * eatt_bearers[MAX_NR_EATT_CHANNELS]; 1502 att_server_eatt_bearer_t * eatt_bearer; 1503 att_server_t * att_server; 1504 att_connection_t * att_connection; 1505 hci_con_handle_t con_handle; 1506 hci_connection_t * hci_connection; 1507 1508 switch (packet_type) { 1509 1510 case L2CAP_DATA_PACKET: 1511 eatt_bearer = att_server_eatt_bearer_for_cid(channel); 1512 btstack_assert(eatt_bearer != NULL); 1513 att_server = &eatt_bearer->att_server; 1514 att_connection = &eatt_bearer->att_connection; 1515 att_server_handle_att_pdu(att_server, att_connection, packet, size); 1516 break; 1517 1518 case HCI_EVENT_PACKET: 1519 switch (packet[0]) { 1520 1521 case L2CAP_EVENT_CAN_SEND_NOW: 1522 cid = l2cap_event_packet_sent_get_local_cid(packet); 1523 eatt_bearer = att_server_eatt_bearer_for_cid(cid); 1524 btstack_assert(eatt_bearer != NULL); 1525 att_server = &eatt_bearer->att_server; 1526 att_connection = &eatt_bearer->att_connection; 1527 // only used for EATT request responses 1528 btstack_assert(att_server->state == ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED); 1529 att_server_process_validated_request(att_server, att_connection, eatt_bearer->send_buffer); 1530 break; 1531 1532 case L2CAP_EVENT_PACKET_SENT: 1533 cid = l2cap_event_packet_sent_get_local_cid(packet); 1534 eatt_bearer = att_server_eatt_bearer_for_cid(cid); 1535 btstack_assert(eatt_bearer != NULL); 1536 att_server = &eatt_bearer->att_server; 1537 att_connection = &eatt_bearer->att_connection; 1538 att_server_handle_att_pdu(att_server, att_connection, packet, size); 1539 break; 1540 1541 case L2CAP_EVENT_ECBM_INCOMING_CONNECTION: 1542 cid = l2cap_event_ecbm_incoming_connection_get_local_cid(packet); 1543 1544 // reject if outgoing l2cap connection active, L2CAP/TIM/BV-01-C 1545 con_handle = l2cap_event_ecbm_incoming_connection_get_handle(packet); 1546 hci_connection = hci_connection_for_handle(con_handle); 1547 btstack_assert(hci_connection != NULL); 1548 if (hci_connection->att_server.eatt_outgoing_active) { 1549 hci_connection->att_server.incoming_connection_request = true; 1550 l2cap_ecbm_decline_channels(cid, L2CAP_ECBM_CONNECTION_RESULT_SOME_REFUSED_INSUFFICIENT_RESOURCES_AVAILABLE ); 1551 log_info("Decline incoming connection from %s", bd_addr_to_str(hci_connection->address)); 1552 } else { 1553 num_requested_bearers = l2cap_event_ecbm_incoming_connection_get_num_channels(packet); 1554 for (i = 0; i < num_requested_bearers; i++){ 1555 eatt_bearers[i] = (att_server_eatt_bearer_t *) btstack_linked_list_pop(&att_server_eatt_bearer_pool); 1556 if (eatt_bearers[i] == NULL) { 1557 break; 1558 } 1559 eatt_bearers[i]->att_connection.con_handle = l2cap_event_ecbm_incoming_connection_get_handle(packet); 1560 eatt_bearers[i]->att_server.bearer_type = ATT_BEARER_ENHANCED_LE; 1561 receive_buffers[i] = eatt_bearers[i]->receive_buffer; 1562 btstack_linked_list_add(&att_server_eatt_bearer_active, (btstack_linked_item_t *) eatt_bearers[i]); 1563 } 1564 num_accepted_bearers = i; 1565 status = l2cap_ecbm_accept_channels(cid, num_accepted_bearers, initial_credits, att_server_eatt_receive_buffer_size, receive_buffers, cids); 1566 btstack_assert(status == ERROR_CODE_SUCCESS); 1567 log_info("requested %u, accepted %u", num_requested_bearers, num_accepted_bearers); 1568 for (i=0;i<num_accepted_bearers;i++){ 1569 log_info("eatt l2cap cid: 0x%04x", cids[i]); 1570 eatt_bearers[i]->att_server.l2cap_cid = cids[i]; 1571 } 1572 } 1573 break; 1574 1575 case L2CAP_EVENT_ECBM_CHANNEL_OPENED: 1576 cid = l2cap_event_ecbm_channel_opened_get_local_cid(packet); 1577 status = l2cap_event_ecbm_channel_opened_get_status(packet); 1578 remote_mtu = l2cap_event_ecbm_channel_opened_get_remote_mtu(packet); 1579 eatt_bearer = att_server_eatt_bearer_for_cid(cid); 1580 btstack_assert(eatt_bearer != NULL); 1581 eatt_bearer->att_connection.mtu_exchanged = true; 1582 eatt_bearer->att_connection.mtu = remote_mtu; 1583 eatt_bearer->att_connection.max_mtu = remote_mtu; 1584 log_info("L2CAP_EVENT_ECBM_CHANNEL_OPENED - cid 0x%04x mtu %u, status 0x%02x", cid, remote_mtu, status); 1585 break; 1586 1587 case L2CAP_EVENT_ECBM_RECONFIGURED: 1588 break; 1589 1590 case L2CAP_EVENT_CHANNEL_CLOSED: 1591 eatt_bearer = att_server_eatt_bearer_for_cid(l2cap_event_channel_closed_get_local_cid(packet)); 1592 btstack_assert(eatt_bearers != NULL); 1593 1594 // TODO: finalize - abort queued writes 1595 1596 btstack_linked_list_remove(&att_server_eatt_bearer_active, (btstack_linked_item_t *) eatt_bearer); 1597 btstack_linked_list_add(&att_server_eatt_bearer_pool, (btstack_linked_item_t *) eatt_bearer); 1598 break; 1599 default: 1600 break; 1601 } 1602 break; 1603 default: 1604 btstack_unreachable(); 1605 break; 1606 } 1607 } 1608 1609 // create eatt bearers 1610 uint8_t att_server_eatt_init(uint8_t num_eatt_bearers, uint8_t * storage_buffer, uint16_t storage_size){ 1611 uint16_t size_for_structs = num_eatt_bearers * sizeof(att_server_eatt_bearer_t); 1612 if (storage_size < size_for_structs) { 1613 return ERROR_CODE_MEMORY_CAPACITY_EXCEEDED; 1614 } 1615 1616 // TODO: The minimum ATT_MTU for an Enhanced ATT bearer is 64 octets. 1617 1618 memset(storage_buffer, 0, storage_size); 1619 uint16_t buffer_size_per_bearer = ((storage_size - size_for_structs) / num_eatt_bearers); 1620 att_server_eatt_receive_buffer_size = buffer_size_per_bearer / 2; 1621 att_server_eatt_send_buffer_size = buffer_size_per_bearer / 2; 1622 uint8_t * bearer_buffer = &storage_buffer[size_for_structs]; 1623 uint8_t i; 1624 att_server_eatt_bearer_t * eatt_bearer = (att_server_eatt_bearer_t *) storage_buffer; 1625 log_info("%u EATT bearers with receive buffer size %u", 1626 num_eatt_bearers, att_server_eatt_receive_buffer_size); 1627 for (i=0;i<num_eatt_bearers;i++){ 1628 eatt_bearer->att_connection.con_handle = HCI_CON_HANDLE_INVALID; 1629 eatt_bearer->receive_buffer = bearer_buffer; 1630 bearer_buffer += att_server_eatt_receive_buffer_size; 1631 eatt_bearer->send_buffer = bearer_buffer; 1632 bearer_buffer += att_server_eatt_send_buffer_size; 1633 btstack_linked_list_add(&att_server_eatt_bearer_pool, (btstack_linked_item_t *) eatt_bearer); 1634 eatt_bearer++; 1635 } 1636 // TODO: define minimum EATT MTU 1637 l2cap_ecbm_register_service(att_server_eatt_handler, BLUETOOTH_PSM_EATT, 64, 0, false); 1638 1639 return 0; 1640 } 1641 #endif