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 MATTHIAS 24 * RINGWALD 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 "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 #endif 69 70 #ifndef NVN_NUM_GATT_SERVER_CCC 71 #define NVN_NUM_GATT_SERVER_CCC 20 72 #endif 73 74 static void att_run_for_context(att_server_t * att_server); 75 static att_write_callback_t att_server_write_callback_for_handle(uint16_t handle); 76 static btstack_packet_handler_t att_server_packet_handler_for_handle(uint16_t handle); 77 static void att_server_persistent_ccc_restore(att_server_t * att_server); 78 static void att_server_persistent_ccc_clear(att_server_t * att_server); 79 static void att_server_handle_att_pdu(att_server_t * att_server, uint8_t * packet, uint16_t size); 80 81 typedef enum { 82 ATT_SERVER_RUN_PHASE_1_REQUESTS, 83 ATT_SERVER_RUN_PHASE_2_INDICATIONS, 84 ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS, 85 } att_server_run_phase_t; 86 87 // 88 typedef struct { 89 uint32_t seq_nr; 90 uint16_t att_handle; 91 uint8_t value; 92 uint8_t device_index; 93 } persistent_ccc_entry_t; 94 95 // global 96 static btstack_packet_callback_registration_t hci_event_callback_registration; 97 static btstack_packet_callback_registration_t sm_event_callback_registration; 98 static btstack_packet_handler_t att_client_packet_handler = NULL; 99 static btstack_linked_list_t service_handlers; 100 static btstack_context_callback_registration_t att_client_waiting_for_can_send_registration; 101 102 static att_read_callback_t att_server_client_read_callback; 103 static att_write_callback_t att_server_client_write_callback; 104 105 // round robin 106 static hci_con_handle_t att_server_last_can_send_now = HCI_CON_HANDLE_INVALID; 107 108 static att_server_t * att_server_for_handle(hci_con_handle_t con_handle){ 109 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 110 if (!hci_connection) return NULL; 111 return &hci_connection->att_server; 112 } 113 114 #ifdef ENABLE_GATT_OVER_CLASSIC 115 static att_server_t * att_server_for_l2cap_cid(uint16_t l2cap_cid){ 116 btstack_linked_list_iterator_t it; 117 hci_connections_get_iterator(&it); 118 while(btstack_linked_list_iterator_has_next(&it)){ 119 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 120 att_server_t * att_server = &connection->att_server; 121 if (att_server->l2cap_cid == l2cap_cid) return att_server; 122 } 123 return NULL; 124 } 125 #endif 126 127 #ifdef ENABLE_LE_SIGNED_WRITE 128 static att_server_t * att_server_for_state(att_server_state_t state){ 129 btstack_linked_list_iterator_t it; 130 hci_connections_get_iterator(&it); 131 while(btstack_linked_list_iterator_has_next(&it)){ 132 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 133 att_server_t * att_server = &connection->att_server; 134 if (att_server->state == state) return att_server; 135 } 136 return NULL; 137 } 138 #endif 139 140 static void att_server_request_can_send_now(att_server_t * att_server){ 141 #ifdef ENABLE_GATT_OVER_CLASSIC 142 if (att_server->l2cap_cid != 0){ 143 l2cap_request_can_send_now_event(att_server->l2cap_cid); 144 return; 145 } 146 #endif 147 att_dispatch_server_request_can_send_now_event(att_server->connection.con_handle); 148 } 149 150 static int att_server_can_send_packet(att_server_t * att_server){ 151 #ifdef ENABLE_GATT_OVER_CLASSIC 152 if (att_server->l2cap_cid != 0){ 153 return l2cap_can_send_packet_now(att_server->l2cap_cid); 154 } 155 #endif 156 return att_dispatch_server_can_send_now(att_server->connection.con_handle); 157 } 158 159 static void att_handle_value_indication_notify_client(uint8_t status, uint16_t client_handle, uint16_t attribute_handle){ 160 btstack_packet_handler_t packet_handler = att_server_packet_handler_for_handle(attribute_handle); 161 if (!packet_handler) return; 162 163 uint8_t event[7]; 164 int pos = 0; 165 event[pos++] = ATT_EVENT_HANDLE_VALUE_INDICATION_COMPLETE; 166 event[pos++] = sizeof(event) - 2; 167 event[pos++] = status; 168 little_endian_store_16(event, pos, client_handle); 169 pos += 2; 170 little_endian_store_16(event, pos, attribute_handle); 171 (*packet_handler)(HCI_EVENT_PACKET, 0, &event[0], sizeof(event)); 172 } 173 174 static void att_emit_event_to_all(const uint8_t * event, uint16_t size){ 175 // dispatch to app level handler 176 if (att_client_packet_handler){ 177 (*att_client_packet_handler)(HCI_EVENT_PACKET, 0, (uint8_t*) event, size); 178 } 179 180 // dispatch to service handlers 181 btstack_linked_list_iterator_t it; 182 btstack_linked_list_iterator_init(&it, &service_handlers); 183 while (btstack_linked_list_iterator_has_next(&it)){ 184 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 185 if (!handler->packet_handler) continue; 186 (*handler->packet_handler)(HCI_EVENT_PACKET, 0, (uint8_t*) event, size); 187 } 188 } 189 190 static void att_emit_mtu_event(hci_con_handle_t con_handle, uint16_t mtu){ 191 uint8_t event[6]; 192 int pos = 0; 193 event[pos++] = ATT_EVENT_MTU_EXCHANGE_COMPLETE; 194 event[pos++] = sizeof(event) - 2; 195 little_endian_store_16(event, pos, con_handle); 196 pos += 2; 197 little_endian_store_16(event, pos, mtu); 198 199 // also dispatch to GATT Clients 200 att_dispatch_server_mtu_exchanged(con_handle, mtu); 201 202 // dispatch to app level handler and service handlers 203 att_emit_event_to_all(&event[0], sizeof(event)); 204 } 205 206 static void att_emit_can_send_now_event(void * context){ 207 UNUSED(context); 208 if (!att_client_packet_handler) return; 209 210 uint8_t event[] = { ATT_EVENT_CAN_SEND_NOW, 0}; 211 (*att_client_packet_handler)(HCI_EVENT_PACKET, 0, &event[0], sizeof(event)); 212 } 213 214 static void att_emit_connected_event(att_server_t * att_server){ 215 uint8_t event[11]; 216 int pos = 0; 217 event[pos++] = ATT_EVENT_CONNECTED; 218 event[pos++] = sizeof(event) - 2; 219 event[pos++] = att_server->peer_addr_type; 220 reverse_bd_addr(att_server->peer_address, &event[pos]); 221 pos += 6; 222 little_endian_store_16(event, pos, att_server->connection.con_handle); 223 pos += 2; 224 225 // dispatch to app level handler and service handlers 226 att_emit_event_to_all(&event[0], sizeof(event)); 227 } 228 229 230 static void att_emit_disconnected_event(uint16_t con_handle){ 231 uint8_t event[4]; 232 int pos = 0; 233 event[pos++] = ATT_EVENT_DISCONNECTED; 234 event[pos++] = sizeof(event) - 2; 235 little_endian_store_16(event, pos, con_handle); 236 pos += 2; 237 238 // dispatch to app level handler and service handlers 239 att_emit_event_to_all(&event[0], sizeof(event)); 240 } 241 242 static void att_handle_value_indication_timeout(btstack_timer_source_t *ts){ 243 void * context = btstack_run_loop_get_timer_context(ts); 244 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) context; 245 att_server_t * att_server = att_server_for_handle(con_handle); 246 if (!att_server) return; 247 // @note: after a transcation timeout, no more requests shall be sent over this ATT Bearer 248 // (that's why we don't reset the value_indication_handle) 249 uint16_t att_handle = att_server->value_indication_handle; 250 att_handle_value_indication_notify_client(ATT_HANDLE_VALUE_INDICATION_TIMEOUT, att_server->connection.con_handle, att_handle); 251 } 252 253 static void att_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 254 255 UNUSED(channel); // ok: there is no channel 256 UNUSED(size); // ok: handling own l2cap events 257 258 att_server_t * att_server; 259 hci_con_handle_t con_handle; 260 #ifdef ENABLE_GATT_OVER_CLASSIC 261 bd_addr_t address; 262 #endif 263 264 switch (packet_type) { 265 266 case HCI_EVENT_PACKET: 267 switch (hci_event_packet_get_type(packet)) { 268 269 #ifdef ENABLE_GATT_OVER_CLASSIC 270 case L2CAP_EVENT_INCOMING_CONNECTION: 271 l2cap_event_incoming_connection_get_address(packet, address); 272 l2cap_accept_connection(channel); 273 printf("Accept incoming connection from %s\n", bd_addr_to_str(address)); 274 break; 275 case L2CAP_EVENT_CHANNEL_OPENED: 276 con_handle = l2cap_event_channel_opened_get_handle(packet); 277 att_server = att_server_for_handle(con_handle); 278 if (!att_server) break; 279 // store connection info 280 att_server->peer_addr_type = BD_ADDR_TYPE_CLASSIC; 281 l2cap_event_channel_opened_get_address(packet, att_server->peer_address); 282 att_server->connection.con_handle = con_handle; 283 att_server->l2cap_cid = l2cap_event_channel_opened_get_local_cid(packet); 284 // reset connection properties 285 att_server->state = ATT_SERVER_IDLE; 286 att_server->connection.mtu = l2cap_event_channel_opened_get_remote_mtu(packet); 287 att_server->connection.max_mtu = l2cap_max_mtu(); 288 if (att_server->connection.max_mtu > ATT_REQUEST_BUFFER_SIZE){ 289 att_server->connection.max_mtu = ATT_REQUEST_BUFFER_SIZE; 290 } 291 // TODO: use security level from underlying HCI connection 292 att_server->connection.encryption_key_size = 0; 293 att_server->connection.authenticated = 0; 294 att_server->connection.authorized = 0; 295 // TODO: what to do about le device db? 296 att_server->pairing_active = 0; 297 printf("Connection opened %s, l2cap cid %04x, \n", bd_addr_to_str(address), att_server->l2cap_cid); 298 break; 299 #endif 300 case HCI_EVENT_LE_META: 301 switch (packet[2]) { 302 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 303 con_handle = little_endian_read_16(packet, 4); 304 att_server = att_server_for_handle(con_handle); 305 if (!att_server) break; 306 // store connection info 307 att_server->peer_addr_type = packet[7]; 308 reverse_bd_addr(&packet[8], att_server->peer_address); 309 att_server->connection.con_handle = con_handle; 310 // reset connection properties 311 att_server->state = ATT_SERVER_IDLE; 312 att_server->connection.mtu = ATT_DEFAULT_MTU; 313 att_server->connection.max_mtu = l2cap_max_le_mtu(); 314 if (att_server->connection.max_mtu > ATT_REQUEST_BUFFER_SIZE){ 315 att_server->connection.max_mtu = ATT_REQUEST_BUFFER_SIZE; 316 } 317 att_server->connection.encryption_key_size = 0; 318 att_server->connection.authenticated = 0; 319 att_server->connection.authorized = 0; 320 // workaround: identity resolving can already be complete, at least store result 321 att_server->ir_le_device_db_index = sm_le_device_index(con_handle); 322 att_server->ir_lookup_active = 0; 323 att_server->pairing_active = 0; 324 // notify all - old 325 att_emit_event_to_all(packet, size); 326 // notify all - new 327 att_emit_connected_event(att_server); 328 break; 329 330 default: 331 break; 332 } 333 break; 334 335 case HCI_EVENT_ENCRYPTION_CHANGE: 336 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 337 // check handle 338 con_handle = little_endian_read_16(packet, 3); 339 att_server = att_server_for_handle(con_handle); 340 if (!att_server) break; 341 att_server->connection.encryption_key_size = gap_encryption_key_size(con_handle); 342 att_server->connection.authenticated = gap_authenticated(con_handle); 343 att_server->connection.secure_connection = gap_secure_connection(con_handle); 344 log_info("encrypted key size %u, authenticated %u, secure connectipon %u", 345 att_server->connection.encryption_key_size, att_server->connection.authenticated, att_server->connection.secure_connection); 346 if (hci_event_packet_get_type(packet) == HCI_EVENT_ENCRYPTION_CHANGE){ 347 // restore CCC values when encrypted 348 if (hci_event_encryption_change_get_encryption_enabled(packet)){ 349 att_server_persistent_ccc_restore(att_server); 350 } 351 } 352 att_run_for_context(att_server); 353 break; 354 355 case HCI_EVENT_DISCONNECTION_COMPLETE: 356 // check handle 357 con_handle = hci_event_disconnection_complete_get_connection_handle(packet); 358 att_server = att_server_for_handle(con_handle); 359 if (!att_server) break; 360 att_clear_transaction_queue(&att_server->connection); 361 att_server->connection.con_handle = 0; 362 att_server->pairing_active = 0; 363 att_server->state = ATT_SERVER_IDLE; 364 if (att_server->value_indication_handle){ 365 btstack_run_loop_remove_timer(&att_server->value_indication_timer); 366 uint16_t att_handle = att_server->value_indication_handle; 367 att_server->value_indication_handle = 0; // reset error state 368 att_handle_value_indication_notify_client(ATT_HANDLE_VALUE_INDICATION_DISCONNECT, att_server->connection.con_handle, att_handle); 369 } 370 // notify all - new 371 att_emit_disconnected_event(con_handle); 372 // notify all - old 373 att_emit_event_to_all(packet, size); 374 break; 375 376 // Identity Resolving 377 case SM_EVENT_IDENTITY_RESOLVING_STARTED: 378 con_handle = sm_event_identity_resolving_started_get_handle(packet); 379 att_server = att_server_for_handle(con_handle); 380 if (!att_server) break; 381 log_info("SM_EVENT_IDENTITY_RESOLVING_STARTED"); 382 att_server->ir_lookup_active = 1; 383 break; 384 case SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED: 385 con_handle = sm_event_identity_created_get_handle(packet); 386 att_server = att_server_for_handle(con_handle); 387 if (!att_server) return; 388 att_server->ir_lookup_active = 0; 389 att_server->ir_le_device_db_index = sm_event_identity_resolving_succeeded_get_index(packet); 390 log_info("SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED"); 391 att_run_for_context(att_server); 392 break; 393 case SM_EVENT_IDENTITY_RESOLVING_FAILED: 394 con_handle = sm_event_identity_resolving_failed_get_handle(packet); 395 att_server = att_server_for_handle(con_handle); 396 if (!att_server) break; 397 log_info("SM_EVENT_IDENTITY_RESOLVING_FAILED"); 398 att_server->ir_lookup_active = 0; 399 att_server->ir_le_device_db_index = -1; 400 att_run_for_context(att_server); 401 break; 402 403 // Pairing started - delete stored CCC values 404 // - assumes pairing indicates either new device or re-pairing, in both cases there should be no stored CCC values 405 // - assumes that all events have the con handle as the first field 406 case SM_EVENT_JUST_WORKS_REQUEST: 407 case SM_EVENT_PASSKEY_DISPLAY_NUMBER: 408 case SM_EVENT_PASSKEY_INPUT_NUMBER: 409 case SM_EVENT_NUMERIC_COMPARISON_REQUEST: 410 con_handle = sm_event_just_works_request_get_handle(packet); 411 att_server = att_server_for_handle(con_handle); 412 if (!att_server) break; 413 att_server->pairing_active = 1; 414 log_info("SM Pairing started"); 415 if (att_server->ir_le_device_db_index < 0) break; 416 att_server_persistent_ccc_clear(att_server); 417 // index not valid anymore 418 att_server->ir_le_device_db_index = -1; 419 break; 420 421 // Bonding completed 422 case SM_EVENT_IDENTITY_CREATED: 423 con_handle = sm_event_identity_created_get_handle(packet); 424 att_server = att_server_for_handle(con_handle); 425 if (!att_server) return; 426 att_server->pairing_active = 0; 427 att_server->ir_le_device_db_index = sm_event_identity_created_get_index(packet); 428 att_run_for_context(att_server); 429 break; 430 431 // Pairing complete (with/without bonding=storing of pairing information) 432 case SM_EVENT_PAIRING_COMPLETE: 433 con_handle = sm_event_pairing_complete_get_handle(packet); 434 att_server = att_server_for_handle(con_handle); 435 if (!att_server) return; 436 att_server->pairing_active = 0; 437 att_run_for_context(att_server); 438 break; 439 440 // Authorization 441 case SM_EVENT_AUTHORIZATION_RESULT: { 442 con_handle = sm_event_authorization_result_get_handle(packet); 443 att_server = att_server_for_handle(con_handle); 444 if (!att_server) break; 445 att_server->connection.authorized = sm_event_authorization_result_get_authorization_result(packet); 446 att_server_request_can_send_now(att_server); 447 break; 448 } 449 default: 450 break; 451 } 452 break; 453 #ifdef ENABLE_GATT_OVER_CLASSIC 454 case L2CAP_DATA_PACKET: 455 att_server = att_server_for_l2cap_cid(channel); 456 if (!att_server) break; 457 458 att_server_handle_att_pdu(att_server, packet, size); 459 break; 460 #endif 461 462 default: 463 break; 464 } 465 } 466 467 #ifdef ENABLE_LE_SIGNED_WRITE 468 static void att_signed_write_handle_cmac_result(uint8_t hash[8]){ 469 470 att_server_t * att_server = att_server_for_state(ATT_SERVER_W4_SIGNED_WRITE_VALIDATION); 471 if (!att_server) return; 472 473 uint8_t hash_flipped[8]; 474 reverse_64(hash, hash_flipped); 475 if (memcmp(hash_flipped, &att_server->request_buffer[att_server->request_size-8], 8)){ 476 log_info("ATT Signed Write, invalid signature"); 477 att_server->state = ATT_SERVER_IDLE; 478 return; 479 } 480 log_info("ATT Signed Write, valid signature"); 481 482 // update sequence number 483 uint32_t counter_packet = little_endian_read_32(att_server->request_buffer, att_server->request_size-12); 484 le_device_db_remote_counter_set(att_server->ir_le_device_db_index, counter_packet+1); 485 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 486 att_server_request_can_send_now(att_server); 487 } 488 #endif 489 490 // pre: att_server->state == ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED 491 // pre: can send now 492 // returns: 1 if packet was sent 493 static int att_server_process_validated_request(att_server_t * att_server){ 494 495 l2cap_reserve_packet_buffer(); 496 uint8_t * att_response_buffer = l2cap_get_outgoing_buffer(); 497 uint16_t att_response_size = att_handle_request(&att_server->connection, att_server->request_buffer, att_server->request_size, att_response_buffer); 498 499 #ifdef ENABLE_ATT_DELAYED_RESPONSE 500 if (att_response_size == ATT_READ_RESPONSE_PENDING || att_response_size == ATT_INTERNAL_WRITE_RESPONSE_PENDING){ 501 // update state 502 att_server->state = ATT_SERVER_RESPONSE_PENDING; 503 504 // callback with handle ATT_READ_RESPONSE_PENDING for reads 505 if (att_response_size == ATT_READ_RESPONSE_PENDING){ 506 att_server_client_read_callback(att_server->connection.con_handle, ATT_READ_RESPONSE_PENDING, 0, NULL, 0); 507 } 508 509 // free reserved buffer 510 l2cap_release_packet_buffer(); 511 return 0; 512 } 513 #endif 514 515 // intercept "insufficient authorization" for authenticated connections to allow for user authorization 516 if ((att_response_size >= 4) 517 && (att_response_buffer[0] == ATT_ERROR_RESPONSE) 518 && (att_response_buffer[4] == ATT_ERROR_INSUFFICIENT_AUTHORIZATION) 519 && (att_server->connection.authenticated)){ 520 521 switch (gap_authorization_state(att_server->connection.con_handle)){ 522 case AUTHORIZATION_UNKNOWN: 523 l2cap_release_packet_buffer(); 524 sm_request_pairing(att_server->connection.con_handle); 525 return 0; 526 case AUTHORIZATION_PENDING: 527 l2cap_release_packet_buffer(); 528 return 0; 529 default: 530 break; 531 } 532 } 533 534 att_server->state = ATT_SERVER_IDLE; 535 if (att_response_size == 0) { 536 l2cap_release_packet_buffer(); 537 return 0; 538 } 539 540 l2cap_send_prepared_connectionless(att_server->connection.con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, att_response_size); 541 542 // notify client about MTU exchange result 543 if (att_response_buffer[0] == ATT_EXCHANGE_MTU_RESPONSE){ 544 att_emit_mtu_event(att_server->connection.con_handle, att_server->connection.mtu); 545 } 546 return 1; 547 } 548 549 #ifdef ENABLE_ATT_DELAYED_RESPONSE 550 int att_server_response_ready(hci_con_handle_t con_handle){ 551 att_server_t * att_server = att_server_for_handle(con_handle); 552 if (!att_server) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 553 if (att_server->state != ATT_SERVER_RESPONSE_PENDING) return ERROR_CODE_COMMAND_DISALLOWED; 554 555 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 556 att_server_request_can_send_now(att_server); 557 return ERROR_CODE_SUCCESS; 558 } 559 #endif 560 561 static void att_run_for_context(att_server_t * att_server){ 562 switch (att_server->state){ 563 case ATT_SERVER_REQUEST_RECEIVED: 564 565 // wait until re-encryption as central is complete 566 if (gap_reconnect_security_setup_active(att_server->connection.con_handle)) break; 567 568 // wait until pairing is complete 569 if (att_server->pairing_active) break; 570 571 #ifdef ENABLE_LE_SIGNED_WRITE 572 if (att_server->request_buffer[0] == ATT_SIGNED_WRITE_COMMAND){ 573 log_info("ATT Signed Write!"); 574 if (!sm_cmac_ready()) { 575 log_info("ATT Signed Write, sm_cmac engine not ready. Abort"); 576 att_server->state = ATT_SERVER_IDLE; 577 return; 578 } 579 if (att_server->request_size < (3 + 12)) { 580 log_info("ATT Signed Write, request to short. Abort."); 581 att_server->state = ATT_SERVER_IDLE; 582 return; 583 } 584 if (att_server->ir_lookup_active){ 585 return; 586 } 587 if (att_server->ir_le_device_db_index < 0){ 588 log_info("ATT Signed Write, CSRK not available"); 589 att_server->state = ATT_SERVER_IDLE; 590 return; 591 } 592 593 // check counter 594 uint32_t counter_packet = little_endian_read_32(att_server->request_buffer, att_server->request_size-12); 595 uint32_t counter_db = le_device_db_remote_counter_get(att_server->ir_le_device_db_index); 596 log_info("ATT Signed Write, DB counter %"PRIu32", packet counter %"PRIu32, counter_db, counter_packet); 597 if (counter_packet < counter_db){ 598 log_info("ATT Signed Write, db reports higher counter, abort"); 599 att_server->state = ATT_SERVER_IDLE; 600 return; 601 } 602 603 // signature is { sequence counter, secure hash } 604 sm_key_t csrk; 605 le_device_db_remote_csrk_get(att_server->ir_le_device_db_index, csrk); 606 att_server->state = ATT_SERVER_W4_SIGNED_WRITE_VALIDATION; 607 log_info("Orig Signature: "); 608 log_info_hexdump( &att_server->request_buffer[att_server->request_size-8], 8); 609 uint16_t attribute_handle = little_endian_read_16(att_server->request_buffer, 1); 610 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); 611 return; 612 } 613 #endif 614 // move on 615 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 616 att_server_request_can_send_now(att_server); 617 break; 618 619 default: 620 break; 621 } 622 } 623 624 static int att_server_data_ready_for_phase(att_server_t * att_server, att_server_run_phase_t phase){ 625 switch (phase){ 626 case ATT_SERVER_RUN_PHASE_1_REQUESTS: 627 return att_server->state == ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 628 case ATT_SERVER_RUN_PHASE_2_INDICATIONS: 629 return (!btstack_linked_list_empty(&att_server->indication_requests) && att_server->value_indication_handle == 0); 630 case ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS: 631 return (!btstack_linked_list_empty(&att_server->notification_requests)); 632 } 633 // avoid warning 634 return 0; 635 } 636 637 static void att_server_trigger_send_for_phase(att_server_t * att_server, att_server_run_phase_t phase){ 638 btstack_context_callback_registration_t * client; 639 switch (phase){ 640 case ATT_SERVER_RUN_PHASE_1_REQUESTS: 641 att_server_process_validated_request(att_server); 642 break; 643 case ATT_SERVER_RUN_PHASE_2_INDICATIONS: 644 client = (btstack_context_callback_registration_t*) att_server->indication_requests; 645 btstack_linked_list_remove(&att_server->indication_requests, (btstack_linked_item_t *) client); 646 client->callback(client->context); 647 break; 648 case ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS: 649 client = (btstack_context_callback_registration_t*) att_server->notification_requests; 650 btstack_linked_list_remove(&att_server->notification_requests, (btstack_linked_item_t *) client); 651 client->callback(client->context); 652 break; 653 } 654 } 655 656 static void att_server_handle_can_send_now(void){ 657 658 hci_con_handle_t last_send_con_handle = HCI_CON_HANDLE_INVALID; 659 att_server_t * request_att_server = NULL; 660 int can_send_now = 1; 661 int phase_index; 662 663 for (phase_index = ATT_SERVER_RUN_PHASE_1_REQUESTS; phase_index <= ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS; phase_index++){ 664 att_server_run_phase_t phase = (att_server_run_phase_t) phase_index; 665 hci_con_handle_t skip_connections_until = att_server_last_can_send_now; 666 while (1){ 667 btstack_linked_list_iterator_t it; 668 hci_connections_get_iterator(&it); 669 while(btstack_linked_list_iterator_has_next(&it)){ 670 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 671 att_server_t * att_server = &connection->att_server; 672 673 int data_ready = att_server_data_ready_for_phase(att_server, phase); 674 675 // log_debug("phase %u, handle 0x%04x, skip until 0x%04x, data ready %u", phase, att_server->connection.con_handle, skip_connections_until, data_ready); 676 677 // skip until last sender found (which is also skipped) 678 if (skip_connections_until != HCI_CON_HANDLE_INVALID){ 679 if (data_ready && request_att_server == NULL){ 680 request_att_server = att_server; 681 } 682 if (skip_connections_until == att_server->connection.con_handle){ 683 skip_connections_until = HCI_CON_HANDLE_INVALID; 684 } 685 continue; 686 }; 687 688 if (data_ready){ 689 if (can_send_now){ 690 att_server_trigger_send_for_phase(att_server, phase); 691 last_send_con_handle = att_server->connection.con_handle; 692 can_send_now = att_server_can_send_packet(att_server); 693 data_ready = att_server_data_ready_for_phase(att_server, phase); 694 if (data_ready && request_att_server == NULL){ 695 request_att_server = att_server; 696 } 697 } else { 698 request_att_server = att_server; 699 break; 700 } 701 } 702 } 703 704 // stop skipping (handles disconnect by last send connection) 705 skip_connections_until = HCI_CON_HANDLE_INVALID; 706 707 // Exit loop, if we cannot send 708 if (!can_send_now) break; 709 710 // Exit loop, if we can send but there are also no further request 711 if (request_att_server == NULL) break; 712 713 // Finally, if we still can send and there are requests, just try again 714 request_att_server = NULL; 715 } 716 // update last send con handle for round robin 717 if (last_send_con_handle != HCI_CON_HANDLE_INVALID){ 718 att_server_last_can_send_now = last_send_con_handle; 719 } 720 } 721 722 if (request_att_server == NULL) return; 723 att_server_request_can_send_now(request_att_server); 724 } 725 726 static void att_server_handle_att_pdu(att_server_t * att_server, uint8_t * packet, uint16_t size){ 727 728 // handle value indication confirms 729 if (packet[0] == ATT_HANDLE_VALUE_CONFIRMATION && att_server->value_indication_handle){ 730 btstack_run_loop_remove_timer(&att_server->value_indication_timer); 731 uint16_t att_handle = att_server->value_indication_handle; 732 att_server->value_indication_handle = 0; 733 att_handle_value_indication_notify_client(0, att_server->connection.con_handle, att_handle); 734 att_server_request_can_send_now(att_server); 735 return; 736 } 737 738 // directly process command 739 // note: signed write cannot be handled directly as authentication needs to be verified 740 if (packet[0] == ATT_WRITE_COMMAND){ 741 att_handle_request(&att_server->connection, packet, size, 0); 742 return; 743 } 744 745 // check size 746 if (size > sizeof(att_server->request_buffer)) { 747 log_info("drop att pdu 0x%02x as size %u > att_server->request_buffer %u", packet[0], size, (int) sizeof(att_server->request_buffer)); 748 return; 749 } 750 751 #ifdef ENABLE_LE_SIGNED_WRITE 752 // abort signed write validation if a new request comes in (but finish previous signed write if possible) 753 if (att_server->state == ATT_SERVER_W4_SIGNED_WRITE_VALIDATION){ 754 if (packet[0] == ATT_SIGNED_WRITE_COMMAND){ 755 log_info("skip new signed write request as previous is in validation"); 756 return; 757 } else { 758 log_info("abort signed write validation to process new request"); 759 att_server->state = ATT_SERVER_IDLE; 760 } 761 } 762 #endif 763 // last request still in processing? 764 if (att_server->state != ATT_SERVER_IDLE){ 765 log_info("skip att pdu 0x%02x as server not idle (state %u)", packet[0], att_server->state); 766 return; 767 } 768 769 // store request 770 att_server->state = ATT_SERVER_REQUEST_RECEIVED; 771 att_server->request_size = size; 772 memcpy(att_server->request_buffer, packet, size); 773 774 att_run_for_context(att_server); 775 } 776 777 static void att_packet_handler(uint8_t packet_type, uint16_t handle, uint8_t *packet, uint16_t size){ 778 att_server_t * att_server; 779 780 switch (packet_type){ 781 case HCI_EVENT_PACKET: 782 switch (packet[0]){ 783 case L2CAP_EVENT_CAN_SEND_NOW: 784 att_server_handle_can_send_now(); 785 break; 786 case ATT_EVENT_MTU_EXCHANGE_COMPLETE: 787 // GATT client has negotiated the mtu for this connection 788 att_server = att_server_for_handle(handle); 789 if (!att_server) break; 790 att_server->connection.mtu = little_endian_read_16(packet, 4); 791 break; 792 default: 793 break; 794 } 795 break; 796 797 case ATT_DATA_PACKET: 798 log_debug("ATT Packet, handle 0x%04x", handle); 799 att_server = att_server_for_handle(handle); 800 if (!att_server) break; 801 802 att_server_handle_att_pdu(att_server, packet, size); 803 break; 804 } 805 } 806 807 // --------------------- 808 // persistent CCC writes 809 static uint32_t att_server_persistent_ccc_tag_for_index(uint8_t index){ 810 return 'B' << 24 | 'T' << 16 | 'C' << 8 | index; 811 } 812 813 static void att_server_persistent_ccc_write(hci_con_handle_t con_handle, uint16_t att_handle, uint16_t value){ 814 // lookup att_server instance 815 att_server_t * att_server = att_server_for_handle(con_handle); 816 if (!att_server) return; 817 int le_device_index = att_server->ir_le_device_db_index; 818 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); 819 820 // check if bonded 821 if (le_device_index < 0) return; 822 823 // get btstack_tlv 824 const btstack_tlv_t * tlv_impl = NULL; 825 void * tlv_context; 826 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 827 if (!tlv_impl) return; 828 829 // update ccc tag 830 int index; 831 uint32_t highest_seq_nr = 0; 832 uint32_t lowest_seq_nr = 0; 833 uint32_t tag_for_lowest_seq_nr = 0; 834 uint32_t tag_for_empty = 0; 835 persistent_ccc_entry_t entry; 836 for (index=0;index<NVN_NUM_GATT_SERVER_CCC;index++){ 837 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 838 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 839 840 // empty/invalid tag 841 if (len != sizeof(persistent_ccc_entry_t)){ 842 tag_for_empty = tag; 843 continue; 844 } 845 // update highest seq nr 846 if (entry.seq_nr > highest_seq_nr){ 847 highest_seq_nr = entry.seq_nr; 848 } 849 // find entry with lowest seq nr 850 if ((tag_for_lowest_seq_nr == 0) || (entry.seq_nr < lowest_seq_nr)){ 851 tag_for_lowest_seq_nr = tag; 852 lowest_seq_nr = entry.seq_nr; 853 } 854 855 if (entry.device_index != le_device_index) continue; 856 if (entry.att_handle != att_handle) continue; 857 858 // found matching entry 859 if (value){ 860 // update 861 if (entry.value == value) { 862 log_info("CCC Index %u: Up-to-date", index); 863 return; 864 } 865 entry.value = value; 866 entry.seq_nr = highest_seq_nr + 1; 867 log_info("CCC Index %u: Store", index); 868 tlv_impl->store_tag(tlv_context, tag, (const uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 869 } else { 870 // delete 871 log_info("CCC Index %u: Delete", index); 872 tlv_impl->delete_tag(tlv_context, tag); 873 } 874 return; 875 } 876 877 log_info("tag_for_empy %"PRIx32", tag_for_lowest_seq_nr %"PRIx32, tag_for_empty, tag_for_lowest_seq_nr); 878 879 if (value == 0){ 880 // done 881 return; 882 } 883 884 uint32_t tag_to_use = 0; 885 if (tag_for_empty){ 886 tag_to_use = tag_for_empty; 887 } else if (tag_for_lowest_seq_nr){ 888 tag_to_use = tag_for_lowest_seq_nr; 889 } else { 890 // should not happen 891 return; 892 } 893 // store ccc tag 894 entry.seq_nr = highest_seq_nr + 1; 895 entry.device_index = le_device_index; 896 entry.att_handle = att_handle; 897 entry.value = value; 898 tlv_impl->store_tag(tlv_context, tag_to_use, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 899 } 900 901 static void att_server_persistent_ccc_clear(att_server_t * att_server){ 902 if (!att_server) return; 903 int le_device_index = att_server->ir_le_device_db_index; 904 log_info("Clear CCC values of remote %s, le device id %d", bd_addr_to_str(att_server->peer_address), le_device_index); 905 // check if bonded 906 if (le_device_index < 0) return; 907 // get btstack_tlv 908 const btstack_tlv_t * tlv_impl = NULL; 909 void * tlv_context; 910 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 911 if (!tlv_impl) return; 912 // get all ccc tag 913 int index; 914 persistent_ccc_entry_t entry; 915 for (index=0;index<NVN_NUM_GATT_SERVER_CCC;index++){ 916 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 917 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 918 if (len != sizeof(persistent_ccc_entry_t)) continue; 919 if (entry.device_index != le_device_index) continue; 920 // delete entry 921 log_info("CCC Index %u: Delete", index); 922 tlv_impl->delete_tag(tlv_context, tag); 923 } 924 } 925 926 static void att_server_persistent_ccc_restore(att_server_t * att_server){ 927 if (!att_server) return; 928 int le_device_index = att_server->ir_le_device_db_index; 929 log_info("Restore CCC values of remote %s, le device id %d", bd_addr_to_str(att_server->peer_address), le_device_index); 930 // check if bonded 931 if (le_device_index < 0) return; 932 // get btstack_tlv 933 const btstack_tlv_t * tlv_impl = NULL; 934 void * tlv_context; 935 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 936 if (!tlv_impl) return; 937 // get all ccc tag 938 int index; 939 persistent_ccc_entry_t entry; 940 for (index=0;index<NVN_NUM_GATT_SERVER_CCC;index++){ 941 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 942 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 943 if (len != sizeof(persistent_ccc_entry_t)) continue; 944 if (entry.device_index != le_device_index) continue; 945 // simulate write callback 946 uint16_t attribute_handle = entry.att_handle; 947 uint8_t value[2]; 948 little_endian_store_16(value, 0, entry.value); 949 att_write_callback_t callback = att_server_write_callback_for_handle(attribute_handle); 950 if (!callback) continue; 951 log_info("CCC Index %u: Set Attribute handle 0x%04x to value 0x%04x", index, attribute_handle, entry.value ); 952 (*callback)(att_server->connection.con_handle, attribute_handle, ATT_TRANSACTION_MODE_NONE, 0, value, sizeof(value)); 953 } 954 } 955 956 // persistent CCC writes 957 // --------------------- 958 959 // gatt service management 960 static att_service_handler_t * att_service_handler_for_handle(uint16_t handle){ 961 btstack_linked_list_iterator_t it; 962 btstack_linked_list_iterator_init(&it, &service_handlers); 963 while (btstack_linked_list_iterator_has_next(&it)){ 964 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 965 if (handler->start_handle > handle) continue; 966 if (handler->end_handle < handle) continue; 967 return handler; 968 } 969 return NULL; 970 } 971 static att_read_callback_t att_server_read_callback_for_handle(uint16_t handle){ 972 att_service_handler_t * handler = att_service_handler_for_handle(handle); 973 if (handler) return handler->read_callback; 974 return att_server_client_read_callback; 975 } 976 977 static att_write_callback_t att_server_write_callback_for_handle(uint16_t handle){ 978 att_service_handler_t * handler = att_service_handler_for_handle(handle); 979 if (handler) return handler->write_callback; 980 return att_server_client_write_callback; 981 } 982 983 static btstack_packet_handler_t att_server_packet_handler_for_handle(uint16_t handle){ 984 att_service_handler_t * handler = att_service_handler_for_handle(handle); 985 if (handler) return handler->packet_handler; 986 return att_client_packet_handler; 987 } 988 989 static void att_notify_write_callbacks(hci_con_handle_t con_handle, uint16_t transaction_mode){ 990 // notify all callbacks 991 btstack_linked_list_iterator_t it; 992 btstack_linked_list_iterator_init(&it, &service_handlers); 993 while (btstack_linked_list_iterator_has_next(&it)){ 994 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 995 if (!handler->write_callback) continue; 996 (*handler->write_callback)(con_handle, 0, transaction_mode, 0, NULL, 0); 997 } 998 if (!att_server_client_write_callback) return; 999 (*att_server_client_write_callback)(con_handle, 0, transaction_mode, 0, NULL, 0); 1000 } 1001 1002 // returns first reported error or 0 1003 static uint8_t att_validate_prepared_write(hci_con_handle_t con_handle){ 1004 btstack_linked_list_iterator_t it; 1005 btstack_linked_list_iterator_init(&it, &service_handlers); 1006 while (btstack_linked_list_iterator_has_next(&it)){ 1007 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 1008 if (!handler->write_callback) continue; 1009 uint8_t error_code = (*handler->write_callback)(con_handle, 0, ATT_TRANSACTION_MODE_VALIDATE, 0, NULL, 0); 1010 if (error_code) return error_code; 1011 } 1012 if (!att_server_client_write_callback) return 0; 1013 return (*att_server_client_write_callback)(con_handle, 0, ATT_TRANSACTION_MODE_VALIDATE, 0, NULL, 0); 1014 } 1015 1016 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){ 1017 att_read_callback_t callback = att_server_read_callback_for_handle(attribute_handle); 1018 if (!callback) return 0; 1019 return (*callback)(con_handle, attribute_handle, offset, buffer, buffer_size); 1020 } 1021 1022 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){ 1023 switch (transaction_mode){ 1024 case ATT_TRANSACTION_MODE_VALIDATE: 1025 return att_validate_prepared_write(con_handle); 1026 case ATT_TRANSACTION_MODE_EXECUTE: 1027 case ATT_TRANSACTION_MODE_CANCEL: 1028 att_notify_write_callbacks(con_handle, transaction_mode); 1029 return 0; 1030 default: 1031 break; 1032 } 1033 1034 // track CCC writes 1035 if (att_is_persistent_ccc(attribute_handle) && offset == 0 && buffer_size == 2){ 1036 att_server_persistent_ccc_write(con_handle, attribute_handle, little_endian_read_16(buffer, 0)); 1037 } 1038 1039 att_write_callback_t callback = att_server_write_callback_for_handle(attribute_handle); 1040 if (!callback) return 0; 1041 return (*callback)(con_handle, attribute_handle, transaction_mode, offset, buffer, buffer_size); 1042 } 1043 1044 /** 1045 * @brief register read/write callbacks for specific handle range 1046 * @param att_service_handler_t 1047 */ 1048 void att_server_register_service_handler(att_service_handler_t * handler){ 1049 if (att_service_handler_for_handle(handler->start_handle) || 1050 att_service_handler_for_handle(handler->end_handle)){ 1051 log_error("handler for range 0x%04x-0x%04x already registered", handler->start_handle, handler->end_handle); 1052 return; 1053 } 1054 btstack_linked_list_add(&service_handlers, (btstack_linked_item_t*) handler); 1055 } 1056 1057 void att_server_init(uint8_t const * db, att_read_callback_t read_callback, att_write_callback_t write_callback){ 1058 1059 // store callbacks 1060 att_server_client_read_callback = read_callback; 1061 att_server_client_write_callback = write_callback; 1062 1063 // register for HCI Events 1064 hci_event_callback_registration.callback = &att_event_packet_handler; 1065 hci_add_event_handler(&hci_event_callback_registration); 1066 1067 // register for SM events 1068 sm_event_callback_registration.callback = &att_event_packet_handler; 1069 sm_add_event_handler(&sm_event_callback_registration); 1070 1071 // and L2CAP ATT Server PDUs 1072 att_dispatch_register_server(att_packet_handler); 1073 1074 #ifdef ENABLE_GATT_OVER_CLASSIC 1075 // setup l2cap service 1076 l2cap_register_service(&att_event_packet_handler, PSM_ATT, 0xffff, LEVEL_2); 1077 #endif 1078 1079 att_set_db(db); 1080 att_set_read_callback(att_server_read_callback); 1081 att_set_write_callback(att_server_write_callback); 1082 } 1083 1084 void att_server_register_packet_handler(btstack_packet_handler_t handler){ 1085 att_client_packet_handler = handler; 1086 } 1087 1088 1089 // to be deprecated 1090 int att_server_can_send_packet_now(hci_con_handle_t con_handle){ 1091 att_server_t * att_server = att_server_for_handle(con_handle); 1092 if (!att_server) return 0; 1093 return att_server_can_send_packet(att_server); 1094 } 1095 1096 int att_server_register_can_send_now_callback(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 1097 return att_server_request_to_send_notification(callback_registration, con_handle); 1098 } 1099 1100 void att_server_request_can_send_now_event(hci_con_handle_t con_handle){ 1101 att_client_waiting_for_can_send_registration.callback = &att_emit_can_send_now_event; 1102 att_server_request_to_send_notification(&att_client_waiting_for_can_send_registration, con_handle); 1103 } 1104 // end of deprecated 1105 1106 int att_server_request_to_send_notification(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 1107 att_server_t * att_server = att_server_for_handle(con_handle); 1108 if (!att_server) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1109 btstack_linked_list_add_tail(&att_server->notification_requests, (btstack_linked_item_t*) callback_registration); 1110 att_server_request_can_send_now(att_server); 1111 return ERROR_CODE_SUCCESS; 1112 } 1113 1114 int att_server_request_to_send_indication(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 1115 att_server_t * att_server = att_server_for_handle(con_handle); 1116 if (!att_server) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1117 btstack_linked_list_add_tail(&att_server->indication_requests, (btstack_linked_item_t*) callback_registration); 1118 att_server_request_can_send_now(att_server); 1119 return ERROR_CODE_SUCCESS; 1120 } 1121 1122 int att_server_notify(hci_con_handle_t con_handle, uint16_t attribute_handle, const uint8_t *value, uint16_t value_len){ 1123 att_server_t * att_server = att_server_for_handle(con_handle); 1124 if (!att_server) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1125 if (!att_server_can_send_packet(att_server)) return BTSTACK_ACL_BUFFERS_FULL; 1126 1127 l2cap_reserve_packet_buffer(); 1128 uint8_t * packet_buffer = l2cap_get_outgoing_buffer(); 1129 uint16_t size = att_prepare_handle_value_notification(&att_server->connection, attribute_handle, value, value_len, packet_buffer); 1130 return l2cap_send_prepared_connectionless(att_server->connection.con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, size); 1131 } 1132 1133 int att_server_indicate(hci_con_handle_t con_handle, uint16_t attribute_handle, const uint8_t *value, uint16_t value_len){ 1134 att_server_t * att_server = att_server_for_handle(con_handle); 1135 if (!att_server) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1136 1137 if (att_server->value_indication_handle) return ATT_HANDLE_VALUE_INDICATION_IN_PROGRESS; 1138 if (!att_server_can_send_packet(att_server)) return BTSTACK_ACL_BUFFERS_FULL; 1139 1140 // track indication 1141 att_server->value_indication_handle = attribute_handle; 1142 btstack_run_loop_set_timer_handler(&att_server->value_indication_timer, att_handle_value_indication_timeout); 1143 btstack_run_loop_set_timer(&att_server->value_indication_timer, ATT_TRANSACTION_TIMEOUT_MS); 1144 btstack_run_loop_add_timer(&att_server->value_indication_timer); 1145 1146 l2cap_reserve_packet_buffer(); 1147 uint8_t * packet_buffer = l2cap_get_outgoing_buffer(); 1148 uint16_t size = att_prepare_handle_value_indication(&att_server->connection, attribute_handle, value, value_len, packet_buffer); 1149 l2cap_send_prepared_connectionless(att_server->connection.con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, size); 1150 return 0; 1151 } 1152 1153 uint16_t att_server_get_mtu(hci_con_handle_t con_handle){ 1154 att_server_t * att_server = att_server_for_handle(con_handle); 1155 if (!att_server) return 0; 1156 return att_server->connection.mtu; 1157 } 1158