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 <stdio.h> 47 #include <stdlib.h> 48 #include <string.h> 49 #include <inttypes.h> 50 51 #include "btstack_config.h" 52 53 #include "att_dispatch.h" 54 #include "ble/att_db.h" 55 #include "ble/att_server.h" 56 #include "ble/core.h" 57 #include "ble/le_device_db.h" 58 #include "ble/sm.h" 59 #include "btstack_debug.h" 60 #include "btstack_event.h" 61 #include "btstack_memory.h" 62 #include "btstack_run_loop.h" 63 #include "gap.h" 64 #include "hci.h" 65 #include "hci_dump.h" 66 #include "l2cap.h" 67 #include "btstack_tlv.h" 68 #ifdef ENABLE_LE_SIGNED_WRITE 69 #include "ble/sm.h" 70 #endif 71 72 #ifndef NVN_NUM_GATT_SERVER_CCC 73 #define NVN_NUM_GATT_SERVER_CCC 20 74 #endif 75 76 static void att_run_for_context(att_server_t * att_server); 77 static att_write_callback_t att_server_write_callback_for_handle(uint16_t handle); 78 static btstack_packet_handler_t att_server_packet_handler_for_handle(uint16_t handle); 79 static void att_server_persistent_ccc_restore(att_server_t * att_server); 80 static void att_server_persistent_ccc_clear(att_server_t * att_server); 81 82 typedef enum { 83 ATT_SERVER_RUN_PHASE_1_REQUESTS, 84 ATT_SERVER_RUN_PHASE_2_INDICATIONS, 85 ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS, 86 } att_server_run_phase_t; 87 88 // 89 typedef struct { 90 uint32_t seq_nr; 91 uint16_t att_handle; 92 uint8_t value; 93 uint8_t device_index; 94 } persistent_ccc_entry_t; 95 96 // global 97 static btstack_packet_callback_registration_t hci_event_callback_registration; 98 static btstack_packet_callback_registration_t sm_event_callback_registration; 99 static btstack_packet_handler_t att_client_packet_handler = NULL; 100 static btstack_linked_list_t service_handlers; 101 static btstack_context_callback_registration_t att_client_waiting_for_can_send_registration; 102 103 static att_read_callback_t att_server_client_read_callback; 104 static att_write_callback_t att_server_client_write_callback; 105 106 // round robin 107 static hci_con_handle_t att_server_last_can_send_now = HCI_CON_HANDLE_INVALID; 108 109 static att_server_t * att_server_for_handle(hci_con_handle_t con_handle){ 110 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 111 if (!hci_connection) return NULL; 112 return &hci_connection->att_server; 113 } 114 115 #ifdef ENABLE_LE_SIGNED_WRITE 116 static att_server_t * att_server_for_state(att_server_state_t state){ 117 btstack_linked_list_iterator_t it; 118 hci_connections_get_iterator(&it); 119 while(btstack_linked_list_iterator_has_next(&it)){ 120 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 121 att_server_t * att_server = &connection->att_server; 122 if (att_server->state == state) return att_server; 123 } 124 return NULL; 125 } 126 #endif 127 128 static void att_handle_value_indication_notify_client(uint8_t status, uint16_t client_handle, uint16_t attribute_handle){ 129 btstack_packet_handler_t packet_handler = att_server_packet_handler_for_handle(attribute_handle); 130 if (!packet_handler) return; 131 132 uint8_t event[7]; 133 int pos = 0; 134 event[pos++] = ATT_EVENT_HANDLE_VALUE_INDICATION_COMPLETE; 135 event[pos++] = sizeof(event) - 2; 136 event[pos++] = status; 137 little_endian_store_16(event, pos, client_handle); 138 pos += 2; 139 little_endian_store_16(event, pos, attribute_handle); 140 (*att_client_packet_handler)(HCI_EVENT_PACKET, 0, &event[0], sizeof(event)); 141 } 142 143 static void att_emit_event_to_all(const uint8_t * event, uint16_t size){ 144 // dispatch to app level handler 145 if (att_client_packet_handler){ 146 (*att_client_packet_handler)(HCI_EVENT_PACKET, 0, (uint8_t*) event, size); 147 } 148 149 // dispatch to service handlers 150 btstack_linked_list_iterator_t it; 151 btstack_linked_list_iterator_init(&it, &service_handlers); 152 while (btstack_linked_list_iterator_has_next(&it)){ 153 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 154 if (!handler->packet_handler) continue; 155 (*handler->packet_handler)(HCI_EVENT_PACKET, 0, (uint8_t*) event, size); 156 } 157 } 158 159 static void att_emit_mtu_event(hci_con_handle_t con_handle, uint16_t mtu){ 160 uint8_t event[6]; 161 int pos = 0; 162 event[pos++] = ATT_EVENT_MTU_EXCHANGE_COMPLETE; 163 event[pos++] = sizeof(event) - 2; 164 little_endian_store_16(event, pos, con_handle); 165 pos += 2; 166 little_endian_store_16(event, pos, mtu); 167 168 // also dispatch to GATT Clients 169 att_dispatch_server_mtu_exchanged(con_handle, mtu); 170 171 // dispatch to app level handler and service handlers 172 att_emit_event_to_all(&event[0], sizeof(event)); 173 } 174 175 static void att_emit_can_send_now_event(void * context){ 176 UNUSED(context); 177 if (!att_client_packet_handler) return; 178 179 uint8_t event[] = { ATT_EVENT_CAN_SEND_NOW, 0}; 180 (*att_client_packet_handler)(HCI_EVENT_PACKET, 0, &event[0], sizeof(event)); 181 } 182 183 static void att_handle_value_indication_timeout(btstack_timer_source_t *ts){ 184 void * context = btstack_run_loop_get_timer_context(ts); 185 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) context; 186 att_server_t * att_server = att_server_for_handle(con_handle); 187 if (!att_server) return; 188 // @note: after a transcation timeout, no more requests shall be sent over this ATT Bearer 189 // (that's why we don't reset the value_indication_handle) 190 uint16_t att_handle = att_server->value_indication_handle; 191 att_handle_value_indication_notify_client(ATT_HANDLE_VALUE_INDICATION_TIMEOUT, att_server->connection.con_handle, att_handle); 192 } 193 194 static void att_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 195 196 UNUSED(channel); // ok: there is no channel 197 UNUSED(size); // ok: handling own l2cap events 198 199 att_server_t * att_server; 200 hci_con_handle_t con_handle; 201 202 switch (packet_type) { 203 204 case HCI_EVENT_PACKET: 205 switch (hci_event_packet_get_type(packet)) { 206 207 case HCI_EVENT_LE_META: 208 switch (packet[2]) { 209 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 210 con_handle = little_endian_read_16(packet, 4); 211 att_server = att_server_for_handle(con_handle); 212 if (!att_server) break; 213 // store connection info 214 att_server->peer_addr_type = packet[7]; 215 reverse_bd_addr(&packet[8], att_server->peer_address); 216 att_server->connection.con_handle = con_handle; 217 // reset connection properties 218 att_server->state = ATT_SERVER_IDLE; 219 att_server->connection.mtu = ATT_DEFAULT_MTU; 220 att_server->connection.max_mtu = l2cap_max_le_mtu(); 221 if (att_server->connection.max_mtu > ATT_REQUEST_BUFFER_SIZE){ 222 att_server->connection.max_mtu = ATT_REQUEST_BUFFER_SIZE; 223 } 224 att_server->connection.encryption_key_size = 0; 225 att_server->connection.authenticated = 0; 226 att_server->connection.authorized = 0; 227 // workaround: identity resolving can already be complete, at least store result 228 att_server->ir_le_device_db_index = sm_le_device_index(con_handle); 229 att_server->pairing_active = 0; 230 // notify all 231 att_emit_event_to_all(packet, size); 232 break; 233 234 default: 235 break; 236 } 237 break; 238 239 case HCI_EVENT_ENCRYPTION_CHANGE: 240 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 241 // check handle 242 con_handle = little_endian_read_16(packet, 3); 243 att_server = att_server_for_handle(con_handle); 244 if (!att_server) break; 245 att_server->connection.encryption_key_size = gap_encryption_key_size(con_handle); 246 att_server->connection.authenticated = gap_authenticated(con_handle); 247 if (hci_event_packet_get_type(packet) == HCI_EVENT_ENCRYPTION_CHANGE){ 248 // restore CCC values when encrypted 249 if (hci_event_encryption_change_get_encryption_enabled(packet)){ 250 att_server_persistent_ccc_restore(att_server); 251 } 252 } 253 att_run_for_context(att_server); 254 break; 255 256 case HCI_EVENT_DISCONNECTION_COMPLETE: 257 // check handle 258 con_handle = hci_event_disconnection_complete_get_connection_handle(packet); 259 att_server = att_server_for_handle(con_handle); 260 if (!att_server) break; 261 att_clear_transaction_queue(&att_server->connection); 262 att_server->connection.con_handle = 0; 263 att_server->pairing_active = 0; 264 att_server->state = ATT_SERVER_IDLE; 265 if (att_server->value_indication_handle){ 266 btstack_run_loop_remove_timer(&att_server->value_indication_timer); 267 uint16_t att_handle = att_server->value_indication_handle; 268 att_server->value_indication_handle = 0; // reset error state 269 att_handle_value_indication_notify_client(ATT_HANDLE_VALUE_INDICATION_DISCONNECT, att_server->connection.con_handle, att_handle); 270 } 271 // notify all 272 att_emit_event_to_all(packet, size); 273 break; 274 275 // Identity Resolving 276 case SM_EVENT_IDENTITY_RESOLVING_STARTED: 277 con_handle = sm_event_identity_resolving_started_get_handle(packet); 278 att_server = att_server_for_handle(con_handle); 279 if (!att_server) break; 280 log_info("SM_EVENT_IDENTITY_RESOLVING_STARTED"); 281 att_server->ir_lookup_active = 1; 282 break; 283 case SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED: 284 con_handle = sm_event_identity_created_get_handle(packet); 285 att_server = att_server_for_handle(con_handle); 286 if (!att_server) return; 287 att_server->ir_lookup_active = 0; 288 att_server->ir_le_device_db_index = sm_event_identity_resolving_succeeded_get_index(packet); 289 log_info("SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED"); 290 att_run_for_context(att_server); 291 break; 292 case SM_EVENT_IDENTITY_RESOLVING_FAILED: 293 con_handle = sm_event_identity_resolving_failed_get_handle(packet); 294 att_server = att_server_for_handle(con_handle); 295 if (!att_server) break; 296 log_info("SM_EVENT_IDENTITY_RESOLVING_FAILED"); 297 att_server->ir_lookup_active = 0; 298 att_server->ir_le_device_db_index = -1; 299 att_run_for_context(att_server); 300 break; 301 302 // Pairing started - delete stored CCC values 303 // - assumes pairing indicates either new device or re-pairing, in both cases there should be no stored CCC values 304 // - assumes that all events have the con handle as the first field 305 case SM_EVENT_JUST_WORKS_REQUEST: 306 case SM_EVENT_PASSKEY_DISPLAY_NUMBER: 307 case SM_EVENT_PASSKEY_INPUT_NUMBER: 308 case SM_EVENT_NUMERIC_COMPARISON_REQUEST: 309 con_handle = sm_event_just_works_request_get_handle(packet); 310 att_server = att_server_for_handle(con_handle); 311 if (!att_server) break; 312 att_server->pairing_active = 1; 313 log_info("SM Pairing started"); 314 if (att_server->ir_le_device_db_index < 0) break; 315 att_server_persistent_ccc_clear(att_server); 316 // index not valid anymore 317 att_server->ir_le_device_db_index = -1; 318 break; 319 320 // Bonding completed 321 case SM_EVENT_IDENTITY_CREATED: 322 con_handle = sm_event_identity_created_get_handle(packet); 323 att_server = att_server_for_handle(con_handle); 324 if (!att_server) return; 325 att_server->pairing_active = 0; 326 att_server->ir_le_device_db_index = sm_event_identity_created_get_index(packet); 327 att_run_for_context(att_server); 328 break; 329 330 // Pairing complete (with/without bonding=storing of pairing information) 331 case SM_EVENT_PAIRING_COMPLETE: 332 con_handle = sm_event_pairing_complete_get_handle(packet); 333 att_server = att_server_for_handle(con_handle); 334 if (!att_server) return; 335 att_server->pairing_active = 0; 336 att_run_for_context(att_server); 337 break; 338 339 // Authorization 340 case SM_EVENT_AUTHORIZATION_RESULT: { 341 con_handle = sm_event_authorization_result_get_handle(packet); 342 att_server = att_server_for_handle(con_handle); 343 if (!att_server) break; 344 att_server->connection.authorized = sm_event_authorization_result_get_authorization_result(packet); 345 att_dispatch_server_request_can_send_now_event(con_handle); 346 break; 347 } 348 default: 349 break; 350 } 351 break; 352 default: 353 break; 354 } 355 } 356 357 #ifdef ENABLE_LE_SIGNED_WRITE 358 static void att_signed_write_handle_cmac_result(uint8_t hash[8]){ 359 360 att_server_t * att_server = att_server_for_state(ATT_SERVER_W4_SIGNED_WRITE_VALIDATION); 361 if (!att_server) return; 362 363 uint8_t hash_flipped[8]; 364 reverse_64(hash, hash_flipped); 365 if (memcmp(hash_flipped, &att_server->request_buffer[att_server->request_size-8], 8)){ 366 log_info("ATT Signed Write, invalid signature"); 367 att_server->state = ATT_SERVER_IDLE; 368 return; 369 } 370 log_info("ATT Signed Write, valid signature"); 371 372 // update sequence number 373 uint32_t counter_packet = little_endian_read_32(att_server->request_buffer, att_server->request_size-12); 374 le_device_db_remote_counter_set(att_server->ir_le_device_db_index, counter_packet+1); 375 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 376 att_dispatch_server_request_can_send_now_event(att_server->connection.con_handle); 377 } 378 #endif 379 380 // pre: att_server->state == ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED 381 // pre: can send now 382 // returns: 1 if packet was sent 383 static int att_server_process_validated_request(att_server_t * att_server){ 384 385 l2cap_reserve_packet_buffer(); 386 uint8_t * att_response_buffer = l2cap_get_outgoing_buffer(); 387 uint16_t att_response_size = att_handle_request(&att_server->connection, att_server->request_buffer, att_server->request_size, att_response_buffer); 388 389 #ifdef ENABLE_ATT_DELAYED_READ_RESPONSE 390 if (att_response_size == ATT_READ_RESPONSE_PENDING){ 391 // update state 392 att_server->state = ATT_SERVER_READ_RESPONSE_PENDING; 393 394 // callback with handle ATT_READ_RESPONSE_PENDING 395 att_server_client_read_callback(att_server->connection.con_handle, ATT_READ_RESPONSE_PENDING, 0, NULL, 0); 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_READ_RESPONSE 438 int att_server_read_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_READ_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; 550 551 for (phase = ATT_SERVER_RUN_PHASE_1_REQUESTS; phase <= ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS; phase++){ 552 hci_con_handle_t skip_connections_until = att_server_last_can_send_now; 553 while (1){ 554 btstack_linked_list_iterator_t it; 555 hci_connections_get_iterator(&it); 556 while(btstack_linked_list_iterator_has_next(&it)){ 557 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 558 att_server_t * att_server = &connection->att_server; 559 560 int data_ready = att_server_data_ready_for_phase(att_server, phase); 561 562 // 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); 563 564 // skip until last sender found (which is also skipped) 565 if (skip_connections_until != HCI_CON_HANDLE_INVALID){ 566 if (data_ready && request_con_handle == HCI_CON_HANDLE_INVALID){ 567 request_con_handle = att_server->connection.con_handle; 568 } 569 if (skip_connections_until == att_server->connection.con_handle){ 570 skip_connections_until = HCI_CON_HANDLE_INVALID; 571 } 572 continue; 573 }; 574 575 if (data_ready){ 576 if (can_send_now){ 577 att_server_trigger_send_for_phase(att_server, phase); 578 last_send_con_handle = att_server->connection.con_handle; 579 can_send_now = att_dispatch_server_can_send_now(att_server->connection.con_handle); 580 data_ready = att_server_data_ready_for_phase(att_server, phase); 581 if (data_ready && request_con_handle == HCI_CON_HANDLE_INVALID){ 582 request_con_handle = att_server->connection.con_handle; 583 } 584 } else { 585 request_con_handle = att_server->connection.con_handle; 586 break; 587 } 588 } 589 } 590 591 // stop skipping (handles disconnect by last send connection) 592 skip_connections_until = HCI_CON_HANDLE_INVALID; 593 594 // Exit loop, if we cannot send 595 if (!can_send_now) break; 596 597 // Exit loop, if we can send but there are also no further request 598 if (request_con_handle == HCI_CON_HANDLE_INVALID) break; 599 600 // Finally, if we still can send and there are requests, just try again 601 request_con_handle = HCI_CON_HANDLE_INVALID; 602 } 603 // update last send con handle for round robin 604 if (last_send_con_handle != HCI_CON_HANDLE_INVALID){ 605 att_server_last_can_send_now = last_send_con_handle; 606 } 607 } 608 609 if (request_con_handle == HCI_CON_HANDLE_INVALID) return; 610 att_dispatch_server_request_can_send_now_event(request_con_handle); 611 } 612 613 static void att_packet_handler(uint8_t packet_type, uint16_t handle, uint8_t *packet, uint16_t size){ 614 615 att_server_t * att_server; 616 617 switch (packet_type){ 618 619 case HCI_EVENT_PACKET: 620 switch (packet[0]){ 621 case L2CAP_EVENT_CAN_SEND_NOW: 622 att_server_handle_can_send_now(); 623 break; 624 case ATT_EVENT_MTU_EXCHANGE_COMPLETE: 625 // GATT client has negotiated the mtu for this connection 626 att_server = att_server_for_handle(handle); 627 if (!att_server) break; 628 att_server->connection.mtu = little_endian_read_16(packet, 4); 629 break; 630 default: 631 break; 632 } 633 break; 634 635 case ATT_DATA_PACKET: 636 log_debug("ATT Packet, handle 0x%04x", handle); 637 att_server = att_server_for_handle(handle); 638 if (!att_server) break; 639 640 // handle value indication confirms 641 if (packet[0] == ATT_HANDLE_VALUE_CONFIRMATION && att_server->value_indication_handle){ 642 btstack_run_loop_remove_timer(&att_server->value_indication_timer); 643 uint16_t att_handle = att_server->value_indication_handle; 644 att_server->value_indication_handle = 0; 645 att_handle_value_indication_notify_client(0, att_server->connection.con_handle, att_handle); 646 att_dispatch_server_request_can_send_now_event(att_server->connection.con_handle); 647 return; 648 } 649 650 // directly process command 651 // note: signed write cannot be handled directly as authentication needs to be verified 652 if (packet[0] == ATT_WRITE_COMMAND){ 653 att_handle_request(&att_server->connection, packet, size, 0); 654 return; 655 } 656 657 // check size 658 if (size > sizeof(att_server->request_buffer)) { 659 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)); 660 return; 661 } 662 663 // last request still in processing? 664 if (att_server->state != ATT_SERVER_IDLE){ 665 log_info("att_packet_handler: skipping att pdu 0x%02x as server not idle (state %u)", packet[0], att_server->state); 666 return; 667 } 668 669 // store request 670 att_server->state = ATT_SERVER_REQUEST_RECEIVED; 671 att_server->request_size = size; 672 memcpy(att_server->request_buffer, packet, size); 673 674 att_run_for_context(att_server); 675 break; 676 } 677 } 678 679 // --------------------- 680 // persistent CCC writes 681 static uint32_t att_server_persistent_ccc_tag_for_index(uint8_t index){ 682 return 'B' << 24 | 'T' << 16 | 'C' << 8 | index; 683 } 684 685 static void att_server_persistent_ccc_write(hci_con_handle_t con_handle, uint16_t att_handle, uint16_t value){ 686 // lookup att_server instance 687 att_server_t * att_server = att_server_for_handle(con_handle); 688 if (!att_server) return; 689 int le_device_index = att_server->ir_le_device_db_index; 690 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); 691 692 // check if bonded 693 if (le_device_index < 0) return; 694 695 // get btstack_tlv 696 const btstack_tlv_t * tlv_impl = NULL; 697 void * tlv_context; 698 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 699 if (!tlv_impl) return; 700 701 // update ccc tag 702 int index; 703 uint32_t highest_seq_nr = 0; 704 uint32_t lowest_seq_nr = 0; 705 uint32_t tag_for_lowest_seq_nr = 0; 706 uint32_t tag_for_empty = 0; 707 persistent_ccc_entry_t entry; 708 for (index=0;index<NVN_NUM_GATT_SERVER_CCC;index++){ 709 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 710 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 711 712 // empty/invalid tag 713 if (len != sizeof(persistent_ccc_entry_t)){ 714 tag_for_empty = tag; 715 continue; 716 } 717 // update highest seq nr 718 if (entry.seq_nr > highest_seq_nr){ 719 highest_seq_nr = entry.seq_nr; 720 } 721 // find entry with lowest seq nr 722 if ((tag_for_lowest_seq_nr == 0) || (entry.seq_nr < lowest_seq_nr)){ 723 tag_for_lowest_seq_nr = tag; 724 lowest_seq_nr = entry.seq_nr; 725 } 726 727 if (entry.device_index != le_device_index) continue; 728 if (entry.att_handle != att_handle) continue; 729 730 // found matching entry 731 if (value){ 732 // update 733 if (entry.value == value) { 734 log_info("CCC Index %u: Up-to-date", index); 735 return; 736 } 737 entry.value = value; 738 entry.seq_nr = highest_seq_nr + 1; 739 log_info("CCC Index %u: Store", index); 740 tlv_impl->store_tag(tlv_context, tag, (const uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 741 } else { 742 // delete 743 log_info("CCC Index %u: Delete", index); 744 tlv_impl->delete_tag(tlv_context, tag); 745 } 746 return; 747 } 748 749 log_info("tag_for_empy %"PRIx32", tag_for_lowest_seq_nr %"PRIx32, tag_for_empty, tag_for_lowest_seq_nr); 750 751 if (value == 0){ 752 // done 753 return; 754 } 755 756 uint32_t tag_to_use = 0; 757 if (tag_for_empty){ 758 tag_to_use = tag_for_empty; 759 } else if (tag_for_lowest_seq_nr){ 760 tag_to_use = tag_for_lowest_seq_nr; 761 } else { 762 // should not happen 763 return; 764 } 765 // store ccc tag 766 entry.seq_nr = highest_seq_nr + 1; 767 entry.device_index = le_device_index; 768 entry.att_handle = att_handle; 769 entry.value = value; 770 tlv_impl->store_tag(tlv_context, tag_to_use, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 771 } 772 773 static void att_server_persistent_ccc_clear(att_server_t * att_server){ 774 if (!att_server) return; 775 int le_device_index = att_server->ir_le_device_db_index; 776 log_info("Clear CCC values of remote %s, le device id %d", bd_addr_to_str(att_server->peer_address), le_device_index); 777 // check if bonded 778 if (le_device_index < 0) return; 779 // get btstack_tlv 780 const btstack_tlv_t * tlv_impl = NULL; 781 void * tlv_context; 782 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 783 if (!tlv_impl) return; 784 // get all ccc tag 785 int index; 786 persistent_ccc_entry_t entry; 787 for (index=0;index<NVN_NUM_GATT_SERVER_CCC;index++){ 788 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 789 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 790 if (len != sizeof(persistent_ccc_entry_t)) continue; 791 if (entry.device_index != le_device_index) continue; 792 // delete entry 793 log_info("CCC Index %u: Delete", index); 794 tlv_impl->delete_tag(tlv_context, tag); 795 } 796 } 797 798 static void att_server_persistent_ccc_restore(att_server_t * att_server){ 799 if (!att_server) return; 800 int le_device_index = att_server->ir_le_device_db_index; 801 log_info("Restore CCC values of remote %s, le device id %d", bd_addr_to_str(att_server->peer_address), le_device_index); 802 // check if bonded 803 if (le_device_index < 0) return; 804 // get btstack_tlv 805 const btstack_tlv_t * tlv_impl = NULL; 806 void * tlv_context; 807 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 808 if (!tlv_impl) return; 809 // get all ccc tag 810 int index; 811 persistent_ccc_entry_t entry; 812 for (index=0;index<NVN_NUM_GATT_SERVER_CCC;index++){ 813 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 814 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 815 if (len != sizeof(persistent_ccc_entry_t)) continue; 816 if (entry.device_index != le_device_index) continue; 817 // simulate write callback 818 uint16_t attribute_handle = entry.att_handle; 819 uint8_t value[2]; 820 little_endian_store_16(value, 0, entry.value); 821 att_write_callback_t callback = att_server_write_callback_for_handle(attribute_handle); 822 if (!callback) continue; 823 log_info("CCC Index %u: Set Attribute handle 0x%04x to value 0x%04x", index, attribute_handle, entry.value ); 824 (*callback)(att_server->connection.con_handle, attribute_handle, ATT_TRANSACTION_MODE_NONE, 0, value, sizeof(value)); 825 } 826 } 827 828 // persistent CCC writes 829 // --------------------- 830 831 // gatt service management 832 static att_service_handler_t * att_service_handler_for_handle(uint16_t handle){ 833 btstack_linked_list_iterator_t it; 834 btstack_linked_list_iterator_init(&it, &service_handlers); 835 while (btstack_linked_list_iterator_has_next(&it)){ 836 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 837 if (handler->start_handle > handle) continue; 838 if (handler->end_handle < handle) continue; 839 return handler; 840 } 841 return NULL; 842 } 843 static att_read_callback_t att_server_read_callback_for_handle(uint16_t handle){ 844 att_service_handler_t * handler = att_service_handler_for_handle(handle); 845 if (handler) return handler->read_callback; 846 return att_server_client_read_callback; 847 } 848 849 static att_write_callback_t att_server_write_callback_for_handle(uint16_t handle){ 850 att_service_handler_t * handler = att_service_handler_for_handle(handle); 851 if (handler) return handler->write_callback; 852 return att_server_client_write_callback; 853 } 854 855 static btstack_packet_handler_t att_server_packet_handler_for_handle(uint16_t handle){ 856 att_service_handler_t * handler = att_service_handler_for_handle(handle); 857 if (handler) return handler->packet_handler; 858 return att_client_packet_handler; 859 } 860 861 static void att_notify_write_callbacks(hci_con_handle_t con_handle, uint16_t transaction_mode){ 862 // notify all callbacks 863 btstack_linked_list_iterator_t it; 864 btstack_linked_list_iterator_init(&it, &service_handlers); 865 while (btstack_linked_list_iterator_has_next(&it)){ 866 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 867 if (!handler->write_callback) continue; 868 (*handler->write_callback)(con_handle, 0, transaction_mode, 0, NULL, 0); 869 } 870 if (!att_server_client_write_callback) return; 871 (*att_server_client_write_callback)(con_handle, 0, transaction_mode, 0, NULL, 0); 872 } 873 874 // returns first reported error or 0 875 static uint8_t att_validate_prepared_write(hci_con_handle_t con_handle){ 876 btstack_linked_list_iterator_t it; 877 btstack_linked_list_iterator_init(&it, &service_handlers); 878 while (btstack_linked_list_iterator_has_next(&it)){ 879 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 880 if (!handler->write_callback) continue; 881 uint8_t error_code = (*handler->write_callback)(con_handle, 0, ATT_TRANSACTION_MODE_VALIDATE, 0, NULL, 0); 882 if (error_code) return error_code; 883 } 884 if (!att_server_client_write_callback) return 0; 885 return (*att_server_client_write_callback)(con_handle, 0, ATT_TRANSACTION_MODE_VALIDATE, 0, NULL, 0); 886 } 887 888 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){ 889 att_read_callback_t callback = att_server_read_callback_for_handle(attribute_handle); 890 if (!callback) return 0; 891 return (*callback)(con_handle, attribute_handle, offset, buffer, buffer_size); 892 } 893 894 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){ 895 switch (transaction_mode){ 896 case ATT_TRANSACTION_MODE_VALIDATE: 897 return att_validate_prepared_write(con_handle); 898 case ATT_TRANSACTION_MODE_EXECUTE: 899 case ATT_TRANSACTION_MODE_CANCEL: 900 att_notify_write_callbacks(con_handle, transaction_mode); 901 return 0; 902 default: 903 break; 904 } 905 906 // track CCC writes 907 if (att_is_persistent_ccc(attribute_handle) && offset == 0 && buffer_size == 2){ 908 att_server_persistent_ccc_write(con_handle, attribute_handle, little_endian_read_16(buffer, 0)); 909 } 910 911 att_write_callback_t callback = att_server_write_callback_for_handle(attribute_handle); 912 if (!callback) return 0; 913 return (*callback)(con_handle, attribute_handle, transaction_mode, offset, buffer, buffer_size); 914 } 915 916 /** 917 * @brief register read/write callbacks for specific handle range 918 * @param att_service_handler_t 919 */ 920 void att_server_register_service_handler(att_service_handler_t * handler){ 921 if (att_service_handler_for_handle(handler->start_handle) || 922 att_service_handler_for_handle(handler->end_handle)){ 923 log_error("handler for range 0x%04x-0x%04x already registered", handler->start_handle, handler->end_handle); 924 return; 925 } 926 btstack_linked_list_add(&service_handlers, (btstack_linked_item_t*) handler); 927 } 928 929 void att_server_init(uint8_t const * db, att_read_callback_t read_callback, att_write_callback_t write_callback){ 930 931 // store callbacks 932 att_server_client_read_callback = read_callback; 933 att_server_client_write_callback = write_callback; 934 935 // register for HCI Events 936 hci_event_callback_registration.callback = &att_event_packet_handler; 937 hci_add_event_handler(&hci_event_callback_registration); 938 939 // register for SM events 940 sm_event_callback_registration.callback = &att_event_packet_handler; 941 sm_add_event_handler(&sm_event_callback_registration); 942 943 // and L2CAP ATT Server PDUs 944 att_dispatch_register_server(att_packet_handler); 945 946 att_set_db(db); 947 att_set_read_callback(att_server_read_callback); 948 att_set_write_callback(att_server_write_callback); 949 950 } 951 952 void att_server_register_packet_handler(btstack_packet_handler_t handler){ 953 att_client_packet_handler = handler; 954 } 955 956 957 // to be deprecated 958 int att_server_can_send_packet_now(hci_con_handle_t con_handle){ 959 return att_dispatch_server_can_send_now(con_handle); 960 } 961 962 int att_server_register_can_send_now_callback(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 963 return att_server_request_to_send_notification(callback_registration, con_handle); 964 } 965 966 void att_server_request_can_send_now_event(hci_con_handle_t con_handle){ 967 att_client_waiting_for_can_send_registration.callback = &att_emit_can_send_now_event; 968 att_server_request_to_send_notification(&att_client_waiting_for_can_send_registration, con_handle); 969 } 970 // end of deprecated 971 972 int att_server_request_to_send_notification(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 973 att_server_t * att_server = att_server_for_handle(con_handle); 974 if (!att_server) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 975 btstack_linked_list_add_tail(&att_server->notification_requests, (btstack_linked_item_t*) callback_registration); 976 att_dispatch_server_request_can_send_now_event(con_handle); 977 return ERROR_CODE_SUCCESS; 978 } 979 980 int att_server_request_to_send_indication(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 981 att_server_t * att_server = att_server_for_handle(con_handle); 982 if (!att_server) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 983 btstack_linked_list_add_tail(&att_server->indication_requests, (btstack_linked_item_t*) callback_registration); 984 att_dispatch_server_request_can_send_now_event(con_handle); 985 return ERROR_CODE_SUCCESS; 986 } 987 988 int att_server_notify(hci_con_handle_t con_handle, uint16_t attribute_handle, uint8_t *value, uint16_t value_len){ 989 att_server_t * att_server = att_server_for_handle(con_handle); 990 if (!att_server) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 991 992 if (!att_dispatch_server_can_send_now(con_handle)) return BTSTACK_ACL_BUFFERS_FULL; 993 994 l2cap_reserve_packet_buffer(); 995 uint8_t * packet_buffer = l2cap_get_outgoing_buffer(); 996 uint16_t size = att_prepare_handle_value_notification(&att_server->connection, attribute_handle, value, value_len, packet_buffer); 997 return l2cap_send_prepared_connectionless(att_server->connection.con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, size); 998 } 999 1000 int att_server_indicate(hci_con_handle_t con_handle, uint16_t attribute_handle, uint8_t *value, uint16_t value_len){ 1001 att_server_t * att_server = att_server_for_handle(con_handle); 1002 if (!att_server) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1003 1004 if (att_server->value_indication_handle) return ATT_HANDLE_VALUE_INDICATION_IN_PROGRESS; 1005 if (!att_dispatch_server_can_send_now(con_handle)) return BTSTACK_ACL_BUFFERS_FULL; 1006 1007 // track indication 1008 att_server->value_indication_handle = attribute_handle; 1009 btstack_run_loop_set_timer_handler(&att_server->value_indication_timer, att_handle_value_indication_timeout); 1010 btstack_run_loop_set_timer(&att_server->value_indication_timer, ATT_TRANSACTION_TIMEOUT_MS); 1011 btstack_run_loop_add_timer(&att_server->value_indication_timer); 1012 1013 l2cap_reserve_packet_buffer(); 1014 uint8_t * packet_buffer = l2cap_get_outgoing_buffer(); 1015 uint16_t size = att_prepare_handle_value_indication(&att_server->connection, attribute_handle, value, value_len, packet_buffer); 1016 l2cap_send_prepared_connectionless(att_server->connection.con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, size); 1017 return 0; 1018 } 1019