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 69 #ifndef GATT_SERVER_NUM_PERSISTENT_CCC 70 #define GATT_SERVER_NUM_PERSISTENT_CCC 20 71 #endif 72 73 static void att_run_for_context(att_server_t * att_server); 74 static att_write_callback_t att_server_write_callback_for_handle(uint16_t handle); 75 static void att_server_persistent_ccc_restore(att_server_t * att_server); 76 static void att_server_persistent_ccc_clear(att_server_t * att_server); 77 78 // global 79 static btstack_packet_callback_registration_t hci_event_callback_registration; 80 static btstack_packet_callback_registration_t sm_event_callback_registration; 81 static btstack_packet_handler_t att_client_packet_handler = NULL; 82 static btstack_linked_list_t can_send_now_clients; 83 static btstack_linked_list_t service_handlers; 84 static uint8_t att_client_waiting_for_can_send; 85 86 static att_read_callback_t att_server_client_read_callback; 87 static att_write_callback_t att_server_client_write_callback; 88 89 // track CCC 1-entry cache 90 // static att_server_t * att_persistent_ccc_server; 91 // static hci_con_handle_t att_persistent_ccc_con_handle; 92 93 static att_server_t * att_server_for_handle(hci_con_handle_t con_handle){ 94 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 95 if (!hci_connection) return NULL; 96 return &hci_connection->att_server; 97 } 98 99 #ifdef ENABLE_LE_SIGNED_WRITE 100 static att_server_t * att_server_for_state(att_server_state_t state){ 101 btstack_linked_list_iterator_t it; 102 hci_connections_get_iterator(&it); 103 while(btstack_linked_list_iterator_has_next(&it)){ 104 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 105 att_server_t * att_server = &connection->att_server; 106 if (att_server->state == state) return att_server; 107 } 108 return NULL; 109 } 110 #endif 111 112 static void att_handle_value_indication_notify_client(uint8_t status, uint16_t client_handle, uint16_t attribute_handle){ 113 if (!att_client_packet_handler) return; 114 115 uint8_t event[7]; 116 int pos = 0; 117 event[pos++] = ATT_EVENT_HANDLE_VALUE_INDICATION_COMPLETE; 118 event[pos++] = sizeof(event) - 2; 119 event[pos++] = status; 120 little_endian_store_16(event, pos, client_handle); 121 pos += 2; 122 little_endian_store_16(event, pos, attribute_handle); 123 (*att_client_packet_handler)(HCI_EVENT_PACKET, 0, &event[0], sizeof(event)); 124 } 125 126 static void att_emit_mtu_event(hci_con_handle_t con_handle, uint16_t mtu){ 127 if (!att_client_packet_handler) return; 128 129 uint8_t event[6]; 130 int pos = 0; 131 event[pos++] = ATT_EVENT_MTU_EXCHANGE_COMPLETE; 132 event[pos++] = sizeof(event) - 2; 133 little_endian_store_16(event, pos, con_handle); 134 pos += 2; 135 little_endian_store_16(event, pos, mtu); 136 (*att_client_packet_handler)(HCI_EVENT_PACKET, 0, &event[0], sizeof(event)); 137 } 138 139 static void att_emit_can_send_now_event(void){ 140 if (!att_client_packet_handler) return; 141 142 uint8_t event[] = { ATT_EVENT_CAN_SEND_NOW, 0}; 143 (*att_client_packet_handler)(HCI_EVENT_PACKET, 0, &event[0], sizeof(event)); 144 } 145 146 static void att_handle_value_indication_timeout(btstack_timer_source_t *ts){ 147 void * context = btstack_run_loop_get_timer_context(ts); 148 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) context; 149 att_server_t * att_server = att_server_for_handle(con_handle); 150 if (!att_server) return; 151 uint16_t att_handle = att_server->value_indication_handle; 152 att_handle_value_indication_notify_client(ATT_HANDLE_VALUE_INDICATION_TIMEOUT, att_server->connection.con_handle, att_handle); 153 } 154 155 static void att_device_identified(att_server_t * att_server, uint8_t index){ 156 att_server->ir_lookup_active = 0; 157 att_server->ir_le_device_db_index = index; 158 log_info("Remote device with conn 0%04x registered with index id %u", (int) att_server->connection.con_handle, att_server->ir_le_device_db_index); 159 att_run_for_context(att_server); 160 } 161 162 static void att_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 163 164 UNUSED(channel); // ok: there is no channel 165 UNUSED(size); // ok: handling own l2cap events 166 167 att_server_t * att_server; 168 hci_con_handle_t con_handle; 169 170 switch (packet_type) { 171 172 case HCI_EVENT_PACKET: 173 switch (hci_event_packet_get_type(packet)) { 174 175 case HCI_EVENT_LE_META: 176 switch (packet[2]) { 177 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 178 con_handle = little_endian_read_16(packet, 4); 179 att_server = att_server_for_handle(con_handle); 180 if (!att_server) break; 181 // store connection info 182 att_server->peer_addr_type = packet[7]; 183 reverse_bd_addr(&packet[8], att_server->peer_address); 184 att_server->connection.con_handle = con_handle; 185 // reset connection properties 186 att_server->state = ATT_SERVER_IDLE; 187 att_server->connection.mtu = ATT_DEFAULT_MTU; 188 att_server->connection.max_mtu = l2cap_max_le_mtu(); 189 if (att_server->connection.max_mtu > ATT_REQUEST_BUFFER_SIZE){ 190 att_server->connection.max_mtu = ATT_REQUEST_BUFFER_SIZE; 191 } 192 att_server->connection.encryption_key_size = 0; 193 att_server->connection.authenticated = 0; 194 att_server->connection.authorized = 0; 195 att_server->ir_le_device_db_index = -1; 196 att_server->pairing_active = 0; 197 break; 198 199 default: 200 break; 201 } 202 break; 203 204 case HCI_EVENT_ENCRYPTION_CHANGE: 205 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 206 // check handle 207 con_handle = little_endian_read_16(packet, 3); 208 att_server = att_server_for_handle(con_handle); 209 if (!att_server) break; 210 att_server->connection.encryption_key_size = sm_encryption_key_size(con_handle); 211 att_server->connection.authenticated = sm_authenticated(con_handle); 212 if (hci_event_packet_get_type(packet) == HCI_EVENT_ENCRYPTION_CHANGE){ 213 // restore CCC values when encrypted 214 if (hci_event_encryption_change_get_encryption_enabled(packet)){ 215 att_server_persistent_ccc_restore(att_server); 216 } 217 } 218 break; 219 220 case HCI_EVENT_DISCONNECTION_COMPLETE: 221 // check handle 222 con_handle = hci_event_disconnection_complete_get_connection_handle(packet); 223 att_server = att_server_for_handle(con_handle); 224 if (!att_server) break; 225 att_clear_transaction_queue(&att_server->connection); 226 att_server->connection.con_handle = 0; 227 att_server->value_indication_handle = 0; // reset error state 228 att_server->pairing_active = 0; 229 att_server->state = ATT_SERVER_IDLE; 230 break; 231 232 // Identity Resolving 233 case SM_EVENT_IDENTITY_RESOLVING_STARTED: 234 con_handle = sm_event_identity_resolving_started_get_handle(packet); 235 att_server = att_server_for_handle(con_handle); 236 if (!att_server) break; 237 log_info("SM_EVENT_IDENTITY_RESOLVING_STARTED"); 238 att_server->ir_lookup_active = 1; 239 break; 240 case SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED: 241 con_handle = sm_event_identity_created_get_handle(packet); 242 att_server = att_server_for_handle(con_handle); 243 if (!att_server) return; 244 att_device_identified(att_server, sm_event_identity_resolving_succeeded_get_index(packet)); 245 break; 246 case SM_EVENT_IDENTITY_RESOLVING_FAILED: 247 con_handle = sm_event_identity_resolving_failed_get_handle(packet); 248 att_server = att_server_for_handle(con_handle); 249 if (!att_server) break; 250 log_info("SM_EVENT_IDENTITY_RESOLVING_FAILED"); 251 att_server->ir_lookup_active = 0; 252 att_server->ir_le_device_db_index = -1; 253 att_run_for_context(att_server); 254 break; 255 256 // Pairing started - delete stored CCC values 257 // - assumes pairing indicates either new device or re-pairing, in both cases there should be no stored CCC values 258 // - assumes that all events have the con handle as the first field 259 case SM_EVENT_JUST_WORKS_REQUEST: 260 case SM_EVENT_PASSKEY_DISPLAY_NUMBER: 261 case SM_EVENT_PASSKEY_INPUT_NUMBER: 262 case SM_EVENT_NUMERIC_COMPARISON_REQUEST: 263 con_handle = sm_event_just_works_request_get_handle(packet); 264 att_server = att_server_for_handle(con_handle); 265 if (!att_server) break; 266 att_server->pairing_active = 1; 267 log_info("SM Pairing started"); 268 if (att_server->ir_le_device_db_index < 0) break; 269 att_server_persistent_ccc_clear(att_server); 270 // index not valid anymore 271 att_server->ir_le_device_db_index = -1; 272 break; 273 274 // Pairing completed 275 case SM_EVENT_IDENTITY_CREATED: 276 con_handle = sm_event_identity_created_get_handle(packet); 277 att_server = att_server_for_handle(con_handle); 278 if (!att_server) return; 279 att_server->pairing_active = 0; 280 att_device_identified(att_server, sm_event_identity_created_get_index(packet)); 281 break; 282 283 // Authorization 284 case SM_EVENT_AUTHORIZATION_RESULT: { 285 con_handle = sm_event_authorization_result_get_handle(packet); 286 att_server = att_server_for_handle(con_handle); 287 if (!att_server) break; 288 att_server->connection.authorized = sm_event_authorization_result_get_authorization_result(packet); 289 att_dispatch_server_request_can_send_now_event(con_handle); 290 break; 291 } 292 default: 293 break; 294 } 295 break; 296 default: 297 break; 298 } 299 } 300 301 #ifdef ENABLE_LE_SIGNED_WRITE 302 static void att_signed_write_handle_cmac_result(uint8_t hash[8]){ 303 304 att_server_t * att_server = att_server_for_state(ATT_SERVER_W4_SIGNED_WRITE_VALIDATION); 305 if (!att_server) return; 306 307 uint8_t hash_flipped[8]; 308 reverse_64(hash, hash_flipped); 309 if (memcmp(hash_flipped, &att_server->request_buffer[att_server->request_size-8], 8)){ 310 log_info("ATT Signed Write, invalid signature"); 311 att_server->state = ATT_SERVER_IDLE; 312 return; 313 } 314 log_info("ATT Signed Write, valid signature"); 315 316 // update sequence number 317 uint32_t counter_packet = little_endian_read_32(att_server->request_buffer, att_server->request_size-12); 318 le_device_db_remote_counter_set(att_server->ir_le_device_db_index, counter_packet+1); 319 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 320 att_dispatch_server_request_can_send_now_event(att_server->connection.con_handle); 321 } 322 #endif 323 324 // pre: att_server->state == ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED 325 // pre: can send now 326 // returns: 1 if packet was sent 327 static int att_server_process_validated_request(att_server_t * att_server){ 328 329 l2cap_reserve_packet_buffer(); 330 uint8_t * att_response_buffer = l2cap_get_outgoing_buffer(); 331 uint16_t att_response_size = att_handle_request(&att_server->connection, att_server->request_buffer, att_server->request_size, att_response_buffer); 332 333 // intercept "insufficient authorization" for authenticated connections to allow for user authorization 334 if ((att_response_size >= 4) 335 && (att_response_buffer[0] == ATT_ERROR_RESPONSE) 336 && (att_response_buffer[4] == ATT_ERROR_INSUFFICIENT_AUTHORIZATION) 337 && (att_server->connection.authenticated)){ 338 339 switch (sm_authorization_state(att_server->connection.con_handle)){ 340 case AUTHORIZATION_UNKNOWN: 341 l2cap_release_packet_buffer(); 342 sm_request_pairing(att_server->connection.con_handle); 343 return 0; 344 case AUTHORIZATION_PENDING: 345 l2cap_release_packet_buffer(); 346 return 0; 347 default: 348 break; 349 } 350 } 351 352 att_server->state = ATT_SERVER_IDLE; 353 if (att_response_size == 0) { 354 l2cap_release_packet_buffer(); 355 return 0; 356 } 357 358 l2cap_send_prepared_connectionless(att_server->connection.con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, att_response_size); 359 360 // notify client about MTU exchange result 361 if (att_response_buffer[0] == ATT_EXCHANGE_MTU_RESPONSE){ 362 att_emit_mtu_event(att_server->connection.con_handle, att_server->connection.mtu); 363 } 364 return 1; 365 } 366 367 static void att_run_for_context(att_server_t * att_server){ 368 switch (att_server->state){ 369 case ATT_SERVER_REQUEST_RECEIVED: 370 371 // wait until pairing is complete 372 if (att_server->pairing_active) break; 373 374 #ifdef ENABLE_LE_SIGNED_WRITE 375 if (att_server->request_buffer[0] == ATT_SIGNED_WRITE_COMMAND){ 376 log_info("ATT Signed Write!"); 377 if (!sm_cmac_ready()) { 378 log_info("ATT Signed Write, sm_cmac engine not ready. Abort"); 379 att_server->state = ATT_SERVER_IDLE; 380 return; 381 } 382 if (att_server->request_size < (3 + 12)) { 383 log_info("ATT Signed Write, request to short. Abort."); 384 att_server->state = ATT_SERVER_IDLE; 385 return; 386 } 387 if (att_server->ir_lookup_active){ 388 return; 389 } 390 if (att_server->ir_le_device_db_index < 0){ 391 log_info("ATT Signed Write, CSRK not available"); 392 att_server->state = ATT_SERVER_IDLE; 393 return; 394 } 395 396 // check counter 397 uint32_t counter_packet = little_endian_read_32(att_server->request_buffer, att_server->request_size-12); 398 uint32_t counter_db = le_device_db_remote_counter_get(att_server->ir_le_device_db_index); 399 log_info("ATT Signed Write, DB counter %"PRIu32", packet counter %"PRIu32, counter_db, counter_packet); 400 if (counter_packet < counter_db){ 401 log_info("ATT Signed Write, db reports higher counter, abort"); 402 att_server->state = ATT_SERVER_IDLE; 403 return; 404 } 405 406 // signature is { sequence counter, secure hash } 407 sm_key_t csrk; 408 le_device_db_remote_csrk_get(att_server->ir_le_device_db_index, csrk); 409 att_server->state = ATT_SERVER_W4_SIGNED_WRITE_VALIDATION; 410 log_info("Orig Signature: "); 411 log_info_hexdump( &att_server->request_buffer[att_server->request_size-8], 8); 412 uint16_t attribute_handle = little_endian_read_16(att_server->request_buffer, 1); 413 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); 414 return; 415 } 416 #endif 417 // move on 418 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 419 att_dispatch_server_request_can_send_now_event(att_server->connection.con_handle); 420 break; 421 422 default: 423 break; 424 } 425 } 426 427 static void att_server_handle_can_send_now(void){ 428 429 // NOTE: we get l2cap fixed channel instead of con_handle 430 431 btstack_linked_list_iterator_t it; 432 hci_connections_get_iterator(&it); 433 while(btstack_linked_list_iterator_has_next(&it)){ 434 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 435 att_server_t * att_server = &connection->att_server; 436 if (att_server->state == ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED){ 437 int sent = att_server_process_validated_request(att_server); 438 if (sent && (att_client_waiting_for_can_send || !btstack_linked_list_empty(&can_send_now_clients))){ 439 att_dispatch_server_request_can_send_now_event(att_server->connection.con_handle); 440 return; 441 } 442 } 443 } 444 445 while (!btstack_linked_list_empty(&can_send_now_clients)){ 446 // handle first client 447 btstack_context_callback_registration_t * client = (btstack_context_callback_registration_t*) can_send_now_clients; 448 hci_con_handle_t con_handle = (uintptr_t) client->context; 449 btstack_linked_list_remove(&can_send_now_clients, (btstack_linked_item_t *) client); 450 client->callback(client->context); 451 452 // request again if needed 453 if (!att_dispatch_server_can_send_now(con_handle)){ 454 if (!btstack_linked_list_empty(&can_send_now_clients) || att_client_waiting_for_can_send){ 455 att_dispatch_server_request_can_send_now_event(con_handle); 456 } 457 return; 458 } 459 } 460 461 if (att_client_waiting_for_can_send){ 462 att_client_waiting_for_can_send = 0; 463 att_emit_can_send_now_event(); 464 } 465 } 466 467 static void att_packet_handler(uint8_t packet_type, uint16_t handle, uint8_t *packet, uint16_t size){ 468 469 att_server_t * att_server; 470 471 switch (packet_type){ 472 473 case HCI_EVENT_PACKET: 474 if (packet[0] != L2CAP_EVENT_CAN_SEND_NOW) break; 475 att_server_handle_can_send_now(); 476 break; 477 478 case ATT_DATA_PACKET: 479 log_info("ATT Packet, handle 0x%04x", handle); 480 att_server = att_server_for_handle(handle); 481 if (!att_server) break; 482 483 // handle value indication confirms 484 if (packet[0] == ATT_HANDLE_VALUE_CONFIRMATION && att_server->value_indication_handle){ 485 btstack_run_loop_remove_timer(&att_server->value_indication_timer); 486 uint16_t att_handle = att_server->value_indication_handle; 487 att_server->value_indication_handle = 0; 488 att_handle_value_indication_notify_client(0, att_server->connection.con_handle, att_handle); 489 return; 490 } 491 492 // directly process command 493 // note: signed write cannot be handled directly as authentication needs to be verified 494 if (packet[0] == ATT_WRITE_COMMAND){ 495 att_handle_request(&att_server->connection, packet, size, 0); 496 return; 497 } 498 499 // check size 500 if (size > sizeof(att_server->request_buffer)) { 501 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)); 502 return; 503 } 504 505 // last request still in processing? 506 if (att_server->state != ATT_SERVER_IDLE){ 507 log_info("att_packet_handler: skipping att pdu 0x%02x as server not idle (state %u)", packet[0], att_server->state); 508 return; 509 } 510 511 // store request 512 att_server->state = ATT_SERVER_REQUEST_RECEIVED; 513 att_server->request_size = size; 514 memcpy(att_server->request_buffer, packet, size); 515 516 att_run_for_context(att_server); 517 break; 518 } 519 } 520 521 // --------------------- 522 // persistent CCC writes 523 // TLV value format: le_device_index(8), attribute_handle(16), value (8) 524 static uint32_t att_server_persistent_ccc_tag_for_index(uint8_t index){ 525 return 'B' << 24 | 'T' << 16 | 'C' << 8 | index; 526 } 527 528 static void att_server_persistent_ccc_write(hci_con_handle_t con_handle, uint16_t att_handle, uint16_t value){ 529 // lookup att_server instance 530 att_server_t * att_server = att_server_for_handle(con_handle); 531 if (!att_server) return; 532 int le_device_index = att_server->ir_le_device_db_index; 533 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); 534 // check if bonded 535 if (le_device_index < 0) return; 536 // get btstack_tlv 537 const btstack_tlv_t * tlv_impl = NULL; 538 void * tlv_context; 539 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 540 if (!tlv_impl) return; 541 // update ccc tag 542 int index; 543 uint8_t buffer[4]; 544 int free_index = -1; 545 for (index=0;index<GATT_SERVER_NUM_PERSISTENT_CCC;index++){ 546 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 547 int len = tlv_impl->get_tag(tlv_context, tag, buffer, sizeof(buffer)); 548 if (len == 0){ 549 free_index = index; 550 continue; 551 } 552 if (len != sizeof(buffer)) continue; 553 if (buffer[0] != le_device_index) continue; 554 if (little_endian_read_16(buffer, 1) != att_handle) continue; 555 if (value){ 556 // update 557 if (buffer[3] == value) { 558 log_info("CCC Index %u: Up-to-date", index); 559 return; 560 } 561 buffer[3] = value; 562 log_info("CCC Index %u: Store", index); 563 tlv_impl->store_tag(tlv_context, tag, buffer, sizeof(buffer)); 564 } else { 565 // delete 566 log_info("CCC Index %u: Delete", index); 567 tlv_impl->delete_tag(tlv_context, tag); 568 } 569 return; 570 } 571 if (free_index < 0) return; 572 // store ccc tag 573 buffer[0] = le_device_index; 574 little_endian_store_16(buffer, 1, att_handle); 575 buffer[3] = value; 576 uint32_t tag = att_server_persistent_ccc_tag_for_index(free_index); 577 tlv_impl->store_tag(tlv_context, tag, buffer, sizeof(buffer)); 578 } 579 580 static void att_server_persistent_ccc_clear(att_server_t * att_server){ 581 if (!att_server) return; 582 int le_device_index = att_server->ir_le_device_db_index; 583 log_info("Clear CCC values of remote %s, le device id %d", bd_addr_to_str(att_server->peer_address), le_device_index); 584 // check if bonded 585 if (le_device_index < 0) return; 586 // get btstack_tlv 587 const btstack_tlv_t * tlv_impl = NULL; 588 void * tlv_context; 589 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 590 if (!tlv_impl) return; 591 // get all ccc tag 592 int index; 593 uint8_t buffer[4]; 594 for (index=0;index<GATT_SERVER_NUM_PERSISTENT_CCC;index++){ 595 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 596 int len = tlv_impl->get_tag(tlv_context, tag, buffer, sizeof(buffer)); 597 if (len != sizeof(buffer)) continue; 598 if (buffer[0] != le_device_index) continue; 599 // delete entry 600 log_info("CCC Index %u: Delete", index); 601 tlv_impl->delete_tag(tlv_context, tag); 602 } 603 } 604 605 static void att_server_persistent_ccc_restore(att_server_t * att_server){ 606 if (!att_server) return; 607 int le_device_index = att_server->ir_le_device_db_index; 608 log_info("Restore CCC values of remote %s, le device id %d", bd_addr_to_str(att_server->peer_address), le_device_index); 609 // get btstack_tlv 610 const btstack_tlv_t * tlv_impl = NULL; 611 void * tlv_context; 612 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 613 if (!tlv_impl) return; 614 // get all ccc tag 615 int index; 616 uint8_t buffer[4]; 617 for (index=0;index<GATT_SERVER_NUM_PERSISTENT_CCC;index++){ 618 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 619 int len = tlv_impl->get_tag(tlv_context, tag, buffer, sizeof(buffer)); 620 if (len != sizeof(buffer)) continue; 621 if (buffer[0] != le_device_index) continue; 622 // simulate write callback 623 uint16_t attribute_handle = little_endian_read_16(buffer, 1); 624 uint8_t value[2]; 625 little_endian_store_16(value, 0, buffer[3]); 626 att_write_callback_t callback = att_server_write_callback_for_handle(attribute_handle); 627 if (!callback) continue; 628 log_info("CCC Index %u: Set Attribute handle 0x%04x to value 0x%04x", index, attribute_handle, buffer[3]); 629 (*callback)(att_server->connection.con_handle, attribute_handle, ATT_TRANSACTION_MODE_NONE, 0, value, sizeof(value)); 630 } 631 } 632 633 // persistent CCC writes 634 // --------------------- 635 636 // gatt service management 637 static att_service_handler_t * att_service_handler_for_handle(uint16_t handle){ 638 btstack_linked_list_iterator_t it; 639 btstack_linked_list_iterator_init(&it, &service_handlers); 640 while (btstack_linked_list_iterator_has_next(&it)){ 641 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 642 if (handler->start_handle > handle) continue; 643 if (handler->end_handle < handle) continue; 644 return handler; 645 } 646 return NULL; 647 } 648 static att_read_callback_t att_server_read_callback_for_handle(uint16_t handle){ 649 att_service_handler_t * handler = att_service_handler_for_handle(handle); 650 if (handler) return handler->read_callback; 651 return att_server_client_read_callback; 652 } 653 654 static att_write_callback_t att_server_write_callback_for_handle(uint16_t handle){ 655 att_service_handler_t * handler = att_service_handler_for_handle(handle); 656 if (handler) return handler->write_callback; 657 return att_server_client_write_callback; 658 } 659 660 static void att_notify_write_callbacks(hci_con_handle_t con_handle, uint16_t transaction_mode){ 661 // notify all callbacks 662 btstack_linked_list_iterator_t it; 663 btstack_linked_list_iterator_init(&it, &service_handlers); 664 while (btstack_linked_list_iterator_has_next(&it)){ 665 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 666 if (!handler->write_callback) continue; 667 (*handler->write_callback)(con_handle, 0, transaction_mode, 0, NULL, 0); 668 } 669 if (!att_server_client_write_callback) return; 670 (*att_server_client_write_callback)(con_handle, 0, transaction_mode, 0, NULL, 0); 671 } 672 673 // returns first reported error or 0 674 static uint8_t att_validate_prepared_write(hci_con_handle_t con_handle){ 675 btstack_linked_list_iterator_t it; 676 btstack_linked_list_iterator_init(&it, &service_handlers); 677 while (btstack_linked_list_iterator_has_next(&it)){ 678 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 679 if (!handler->write_callback) continue; 680 uint8_t error_code = (*handler->write_callback)(con_handle, 0, ATT_TRANSACTION_MODE_VALIDATE, 0, NULL, 0); 681 if (error_code) return error_code; 682 } 683 if (!att_server_client_write_callback) return 0; 684 return (*att_server_client_write_callback)(con_handle, 0, ATT_TRANSACTION_MODE_VALIDATE, 0, NULL, 0); 685 } 686 687 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){ 688 att_read_callback_t callback = att_server_read_callback_for_handle(attribute_handle); 689 if (!callback) return 0; 690 return (*callback)(con_handle, attribute_handle, offset, buffer, buffer_size); 691 } 692 693 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){ 694 switch (transaction_mode){ 695 case ATT_TRANSACTION_MODE_VALIDATE: 696 return att_validate_prepared_write(con_handle); 697 case ATT_TRANSACTION_MODE_EXECUTE: 698 case ATT_TRANSACTION_MODE_CANCEL: 699 att_notify_write_callbacks(con_handle, transaction_mode); 700 return 0; 701 default: 702 break; 703 } 704 705 // track CCC writes 706 if (att_is_persistent_ccc(attribute_handle) && offset == 0 && buffer_size == 2){ 707 att_server_persistent_ccc_write(con_handle, attribute_handle, little_endian_read_16(buffer, 0)); 708 } 709 710 att_write_callback_t callback = att_server_write_callback_for_handle(attribute_handle); 711 if (!callback) return 0; 712 return (*callback)(con_handle, attribute_handle, transaction_mode, offset, buffer, buffer_size); 713 } 714 715 /** 716 * @brief register read/write callbacks for specific handle range 717 * @param att_service_handler_t 718 */ 719 void att_server_register_service_handler(att_service_handler_t * handler){ 720 if (att_service_handler_for_handle(handler->start_handle) || 721 att_service_handler_for_handle(handler->end_handle)){ 722 log_error("handler for range 0x%04x-0x%04x already registered", handler->start_handle, handler->end_handle); 723 return; 724 } 725 btstack_linked_list_add(&service_handlers, (btstack_linked_item_t*) handler); 726 } 727 728 void att_server_init(uint8_t const * db, att_read_callback_t read_callback, att_write_callback_t write_callback){ 729 730 // store callbacks 731 att_server_client_read_callback = read_callback; 732 att_server_client_write_callback = write_callback; 733 734 // register for HCI Events 735 hci_event_callback_registration.callback = &att_event_packet_handler; 736 hci_add_event_handler(&hci_event_callback_registration); 737 738 // register for SM events 739 sm_event_callback_registration.callback = &att_event_packet_handler; 740 sm_add_event_handler(&sm_event_callback_registration); 741 742 // and L2CAP ATT Server PDUs 743 att_dispatch_register_server(att_packet_handler); 744 745 att_set_db(db); 746 att_set_read_callback(att_server_read_callback); 747 att_set_write_callback(att_server_write_callback); 748 749 } 750 751 void att_server_register_packet_handler(btstack_packet_handler_t handler){ 752 att_client_packet_handler = handler; 753 } 754 755 int att_server_can_send_packet_now(hci_con_handle_t con_handle){ 756 return att_dispatch_server_can_send_now(con_handle); 757 } 758 759 void att_server_request_can_send_now_event(hci_con_handle_t con_handle){ 760 log_debug("att_server_request_can_send_now_event 0x%04x", con_handle); 761 att_client_waiting_for_can_send = 1; 762 att_dispatch_server_request_can_send_now_event(con_handle); 763 } 764 765 void att_server_register_can_send_now_callback(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 766 // check if can send already 767 if (att_dispatch_server_can_send_now(con_handle)){ 768 callback_registration->callback(callback_registration->context); 769 return; 770 } 771 callback_registration->context = (void*)(uintptr_t) con_handle; 772 btstack_linked_list_add_tail(&can_send_now_clients, (btstack_linked_item_t*) callback_registration); 773 att_dispatch_server_request_can_send_now_event(con_handle); 774 } 775 776 777 int att_server_notify(hci_con_handle_t con_handle, uint16_t attribute_handle, uint8_t *value, uint16_t value_len){ 778 att_server_t * att_server = att_server_for_handle(con_handle); 779 if (!att_server) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 780 781 if (!att_dispatch_server_can_send_now(con_handle)) return BTSTACK_ACL_BUFFERS_FULL; 782 783 l2cap_reserve_packet_buffer(); 784 uint8_t * packet_buffer = l2cap_get_outgoing_buffer(); 785 uint16_t size = att_prepare_handle_value_notification(&att_server->connection, attribute_handle, value, value_len, packet_buffer); 786 return l2cap_send_prepared_connectionless(att_server->connection.con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, size); 787 } 788 789 int att_server_indicate(hci_con_handle_t con_handle, uint16_t attribute_handle, uint8_t *value, uint16_t value_len){ 790 att_server_t * att_server = att_server_for_handle(con_handle); 791 if (!att_server) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 792 793 if (att_server->value_indication_handle) return ATT_HANDLE_VALUE_INDICATION_IN_PROGRESS; 794 if (!att_dispatch_server_can_send_now(con_handle)) return BTSTACK_ACL_BUFFERS_FULL; 795 796 // track indication 797 att_server->value_indication_handle = attribute_handle; 798 btstack_run_loop_set_timer_handler(&att_server->value_indication_timer, att_handle_value_indication_timeout); 799 btstack_run_loop_set_timer(&att_server->value_indication_timer, ATT_TRANSACTION_TIMEOUT_MS); 800 btstack_run_loop_add_timer(&att_server->value_indication_timer); 801 802 l2cap_reserve_packet_buffer(); 803 uint8_t * packet_buffer = l2cap_get_outgoing_buffer(); 804 uint16_t size = att_prepare_handle_value_indication(&att_server->connection, attribute_handle, value, value_len, packet_buffer); 805 l2cap_send_prepared_connectionless(att_server->connection.con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, size); 806 return 0; 807 } 808