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