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_handle_can_send_now(void); 78 static void att_server_persistent_ccc_restore(att_server_t * att_server); 79 static void att_server_persistent_ccc_clear(att_server_t * att_server); 80 static void att_server_handle_att_pdu(att_server_t * att_server, uint8_t * packet, uint16_t size); 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_GATT_OVER_CLASSIC 116 static att_server_t * att_server_for_l2cap_cid(uint16_t l2cap_cid){ 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->l2cap_cid == l2cap_cid) return att_server; 123 } 124 return NULL; 125 } 126 #endif 127 128 #ifdef ENABLE_LE_SIGNED_WRITE 129 static att_server_t * att_server_for_state(att_server_state_t state){ 130 btstack_linked_list_iterator_t it; 131 hci_connections_get_iterator(&it); 132 while(btstack_linked_list_iterator_has_next(&it)){ 133 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 134 att_server_t * att_server = &connection->att_server; 135 if (att_server->state == state) return att_server; 136 } 137 return NULL; 138 } 139 #endif 140 141 static void att_server_request_can_send_now(att_server_t * att_server){ 142 #ifdef ENABLE_GATT_OVER_CLASSIC 143 if (att_server->l2cap_cid != 0){ 144 l2cap_request_can_send_now_event(att_server->l2cap_cid); 145 return; 146 } 147 #endif 148 att_dispatch_server_request_can_send_now_event(att_server->connection.con_handle); 149 } 150 151 static int att_server_can_send_packet(att_server_t * att_server){ 152 #ifdef ENABLE_GATT_OVER_CLASSIC 153 if (att_server->l2cap_cid != 0){ 154 return l2cap_can_send_packet_now(att_server->l2cap_cid); 155 } 156 #endif 157 return att_dispatch_server_can_send_now(att_server->connection.con_handle); 158 } 159 160 static void att_handle_value_indication_notify_client(uint8_t status, uint16_t client_handle, uint16_t attribute_handle){ 161 btstack_packet_handler_t packet_handler = att_server_packet_handler_for_handle(attribute_handle); 162 if (!packet_handler) return; 163 164 uint8_t event[7]; 165 int pos = 0; 166 event[pos++] = ATT_EVENT_HANDLE_VALUE_INDICATION_COMPLETE; 167 event[pos++] = sizeof(event) - 2; 168 event[pos++] = status; 169 little_endian_store_16(event, pos, client_handle); 170 pos += 2; 171 little_endian_store_16(event, pos, attribute_handle); 172 (*packet_handler)(HCI_EVENT_PACKET, 0, &event[0], sizeof(event)); 173 } 174 175 static void att_emit_event_to_all(const uint8_t * event, uint16_t size){ 176 // dispatch to app level handler 177 if (att_client_packet_handler){ 178 (*att_client_packet_handler)(HCI_EVENT_PACKET, 0, (uint8_t*) event, size); 179 } 180 181 // dispatch to service handlers 182 btstack_linked_list_iterator_t it; 183 btstack_linked_list_iterator_init(&it, &service_handlers); 184 while (btstack_linked_list_iterator_has_next(&it)){ 185 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 186 if (!handler->packet_handler) continue; 187 (*handler->packet_handler)(HCI_EVENT_PACKET, 0, (uint8_t*) event, size); 188 } 189 } 190 191 static void att_emit_mtu_event(hci_con_handle_t con_handle, uint16_t mtu){ 192 uint8_t event[6]; 193 int pos = 0; 194 event[pos++] = ATT_EVENT_MTU_EXCHANGE_COMPLETE; 195 event[pos++] = sizeof(event) - 2; 196 little_endian_store_16(event, pos, con_handle); 197 pos += 2; 198 little_endian_store_16(event, pos, mtu); 199 200 // also dispatch to GATT Clients 201 att_dispatch_server_mtu_exchanged(con_handle, mtu); 202 203 // dispatch to app level handler and service handlers 204 att_emit_event_to_all(&event[0], sizeof(event)); 205 } 206 207 static void att_emit_can_send_now_event(void * context){ 208 UNUSED(context); 209 if (!att_client_packet_handler) return; 210 211 uint8_t event[] = { ATT_EVENT_CAN_SEND_NOW, 0}; 212 (*att_client_packet_handler)(HCI_EVENT_PACKET, 0, &event[0], sizeof(event)); 213 } 214 215 static void att_emit_connected_event(att_server_t * att_server){ 216 uint8_t event[11]; 217 int pos = 0; 218 event[pos++] = ATT_EVENT_CONNECTED; 219 event[pos++] = sizeof(event) - 2; 220 event[pos++] = att_server->peer_addr_type; 221 reverse_bd_addr(att_server->peer_address, &event[pos]); 222 pos += 6; 223 little_endian_store_16(event, pos, att_server->connection.con_handle); 224 pos += 2; 225 226 // dispatch to app level handler and service handlers 227 att_emit_event_to_all(&event[0], sizeof(event)); 228 } 229 230 231 static void att_emit_disconnected_event(uint16_t con_handle){ 232 uint8_t event[4]; 233 int pos = 0; 234 event[pos++] = ATT_EVENT_DISCONNECTED; 235 event[pos++] = sizeof(event) - 2; 236 little_endian_store_16(event, pos, con_handle); 237 pos += 2; 238 239 // dispatch to app level handler and service handlers 240 att_emit_event_to_all(&event[0], sizeof(event)); 241 } 242 243 static void att_handle_value_indication_timeout(btstack_timer_source_t *ts){ 244 void * context = btstack_run_loop_get_timer_context(ts); 245 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) context; 246 att_server_t * att_server = att_server_for_handle(con_handle); 247 if (!att_server) return; 248 // @note: after a transcation timeout, no more requests shall be sent over this ATT Bearer 249 // (that's why we don't reset the value_indication_handle) 250 uint16_t att_handle = att_server->value_indication_handle; 251 att_handle_value_indication_notify_client(ATT_HANDLE_VALUE_INDICATION_TIMEOUT, att_server->connection.con_handle, att_handle); 252 } 253 254 static void att_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 255 256 UNUSED(channel); // ok: there is no channel 257 UNUSED(size); // ok: handling own l2cap events 258 259 att_server_t * att_server; 260 hci_con_handle_t con_handle; 261 #ifdef ENABLE_GATT_OVER_CLASSIC 262 bd_addr_t address; 263 #endif 264 265 switch (packet_type) { 266 267 case HCI_EVENT_PACKET: 268 switch (hci_event_packet_get_type(packet)) { 269 270 #ifdef ENABLE_GATT_OVER_CLASSIC 271 case L2CAP_EVENT_INCOMING_CONNECTION: 272 l2cap_event_incoming_connection_get_address(packet, address); 273 l2cap_accept_connection(channel); 274 log_info("Accept incoming connection from %s", bd_addr_to_str(address)); 275 break; 276 case L2CAP_EVENT_CHANNEL_OPENED: 277 con_handle = l2cap_event_channel_opened_get_handle(packet); 278 att_server = att_server_for_handle(con_handle); 279 if (!att_server) break; 280 // store connection info 281 att_server->peer_addr_type = BD_ADDR_TYPE_CLASSIC; 282 l2cap_event_channel_opened_get_address(packet, att_server->peer_address); 283 att_server->connection.con_handle = con_handle; 284 att_server->l2cap_cid = l2cap_event_channel_opened_get_local_cid(packet); 285 // reset connection properties 286 att_server->state = ATT_SERVER_IDLE; 287 att_server->connection.mtu = l2cap_event_channel_opened_get_remote_mtu(packet); 288 att_server->connection.max_mtu = l2cap_max_mtu(); 289 if (att_server->connection.max_mtu > ATT_REQUEST_BUFFER_SIZE){ 290 att_server->connection.max_mtu = ATT_REQUEST_BUFFER_SIZE; 291 } 292 // update security params 293 att_server->connection.encryption_key_size = gap_encryption_key_size(con_handle); 294 att_server->connection.authenticated = gap_authenticated(con_handle); 295 att_server->connection.secure_connection = gap_secure_connection(con_handle); 296 log_info("encrypted key size %u, authenticated %u, secure connection %u", 297 att_server->connection.encryption_key_size, att_server->connection.authenticated, att_server->connection.secure_connection); 298 // restore persisten ccc if encrypted 299 if ( gap_security_level(con_handle) >= LEVEL_2){ 300 att_server_persistent_ccc_restore(att_server); 301 } 302 // TODO: what to do about le device db? 303 att_server->pairing_active = 0; 304 log_info("Connection opened %s, l2cap cid %04x", bd_addr_to_str(address), att_server->l2cap_cid); 305 break; 306 case L2CAP_EVENT_CAN_SEND_NOW: 307 att_server_handle_can_send_now(); 308 break; 309 310 #endif 311 case HCI_EVENT_LE_META: 312 switch (packet[2]) { 313 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 314 con_handle = little_endian_read_16(packet, 4); 315 att_server = att_server_for_handle(con_handle); 316 if (!att_server) break; 317 // store connection info 318 att_server->peer_addr_type = packet[7]; 319 reverse_bd_addr(&packet[8], att_server->peer_address); 320 att_server->connection.con_handle = con_handle; 321 // reset connection properties 322 att_server->state = ATT_SERVER_IDLE; 323 att_server->connection.mtu = ATT_DEFAULT_MTU; 324 att_server->connection.max_mtu = l2cap_max_le_mtu(); 325 if (att_server->connection.max_mtu > ATT_REQUEST_BUFFER_SIZE){ 326 att_server->connection.max_mtu = ATT_REQUEST_BUFFER_SIZE; 327 } 328 att_server->connection.encryption_key_size = 0; 329 att_server->connection.authenticated = 0; 330 att_server->connection.authorized = 0; 331 // workaround: identity resolving can already be complete, at least store result 332 att_server->ir_le_device_db_index = sm_le_device_index(con_handle); 333 att_server->ir_lookup_active = 0; 334 att_server->pairing_active = 0; 335 // notify all - old 336 att_emit_event_to_all(packet, size); 337 // notify all - new 338 att_emit_connected_event(att_server); 339 break; 340 341 default: 342 break; 343 } 344 break; 345 346 case HCI_EVENT_ENCRYPTION_CHANGE: 347 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 348 // check handle 349 con_handle = little_endian_read_16(packet, 3); 350 att_server = att_server_for_handle(con_handle); 351 if (!att_server) break; 352 if (gap_get_connection_type(con_handle) != GAP_CONNECTION_LE) break; 353 // update security params 354 att_server->connection.encryption_key_size = gap_encryption_key_size(con_handle); 355 att_server->connection.authenticated = gap_authenticated(con_handle); 356 att_server->connection.secure_connection = gap_secure_connection(con_handle); 357 log_info("encrypted key size %u, authenticated %u, secure connection %u", 358 att_server->connection.encryption_key_size, att_server->connection.authenticated, att_server->connection.secure_connection); 359 if (hci_event_packet_get_type(packet) == HCI_EVENT_ENCRYPTION_CHANGE){ 360 // restore CCC values when encrypted for LE Connections 361 if (hci_event_encryption_change_get_encryption_enabled(packet)){ 362 att_server_persistent_ccc_restore(att_server); 363 } 364 } 365 att_run_for_context(att_server); 366 break; 367 368 case HCI_EVENT_DISCONNECTION_COMPLETE: 369 // check handle 370 con_handle = hci_event_disconnection_complete_get_connection_handle(packet); 371 att_server = att_server_for_handle(con_handle); 372 if (!att_server) break; 373 att_clear_transaction_queue(&att_server->connection); 374 att_server->connection.con_handle = 0; 375 att_server->pairing_active = 0; 376 att_server->state = ATT_SERVER_IDLE; 377 if (att_server->value_indication_handle){ 378 btstack_run_loop_remove_timer(&att_server->value_indication_timer); 379 uint16_t att_handle = att_server->value_indication_handle; 380 att_server->value_indication_handle = 0; // reset error state 381 att_handle_value_indication_notify_client(ATT_HANDLE_VALUE_INDICATION_DISCONNECT, att_server->connection.con_handle, att_handle); 382 } 383 // notify all - new 384 att_emit_disconnected_event(con_handle); 385 // notify all - old 386 att_emit_event_to_all(packet, size); 387 break; 388 389 // Identity Resolving 390 case SM_EVENT_IDENTITY_RESOLVING_STARTED: 391 con_handle = sm_event_identity_resolving_started_get_handle(packet); 392 att_server = att_server_for_handle(con_handle); 393 if (!att_server) break; 394 log_info("SM_EVENT_IDENTITY_RESOLVING_STARTED"); 395 att_server->ir_lookup_active = 1; 396 break; 397 case SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED: 398 con_handle = sm_event_identity_created_get_handle(packet); 399 att_server = att_server_for_handle(con_handle); 400 if (!att_server) return; 401 att_server->ir_lookup_active = 0; 402 att_server->ir_le_device_db_index = sm_event_identity_resolving_succeeded_get_index(packet); 403 log_info("SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED"); 404 att_run_for_context(att_server); 405 break; 406 case SM_EVENT_IDENTITY_RESOLVING_FAILED: 407 con_handle = sm_event_identity_resolving_failed_get_handle(packet); 408 att_server = att_server_for_handle(con_handle); 409 if (!att_server) break; 410 log_info("SM_EVENT_IDENTITY_RESOLVING_FAILED"); 411 att_server->ir_lookup_active = 0; 412 att_server->ir_le_device_db_index = -1; 413 att_run_for_context(att_server); 414 break; 415 416 // Pairing started - delete stored CCC values 417 // - assumes pairing indicates either new device or re-pairing, in both cases there should be no stored CCC values 418 // - assumes that all events have the con handle as the first field 419 case SM_EVENT_JUST_WORKS_REQUEST: 420 case SM_EVENT_PASSKEY_DISPLAY_NUMBER: 421 case SM_EVENT_PASSKEY_INPUT_NUMBER: 422 case SM_EVENT_NUMERIC_COMPARISON_REQUEST: 423 con_handle = sm_event_just_works_request_get_handle(packet); 424 att_server = att_server_for_handle(con_handle); 425 if (!att_server) break; 426 att_server->pairing_active = 1; 427 log_info("SM Pairing started"); 428 if (att_server->ir_le_device_db_index < 0) break; 429 att_server_persistent_ccc_clear(att_server); 430 // index not valid anymore 431 att_server->ir_le_device_db_index = -1; 432 break; 433 434 // Bonding completed 435 case SM_EVENT_IDENTITY_CREATED: 436 con_handle = sm_event_identity_created_get_handle(packet); 437 att_server = att_server_for_handle(con_handle); 438 if (!att_server) return; 439 att_server->pairing_active = 0; 440 att_server->ir_le_device_db_index = sm_event_identity_created_get_index(packet); 441 att_run_for_context(att_server); 442 break; 443 444 // Pairing complete (with/without bonding=storing of pairing information) 445 case SM_EVENT_PAIRING_COMPLETE: 446 con_handle = sm_event_pairing_complete_get_handle(packet); 447 att_server = att_server_for_handle(con_handle); 448 if (!att_server) return; 449 att_server->pairing_active = 0; 450 att_run_for_context(att_server); 451 break; 452 453 // Authorization 454 case SM_EVENT_AUTHORIZATION_RESULT: { 455 con_handle = sm_event_authorization_result_get_handle(packet); 456 att_server = att_server_for_handle(con_handle); 457 if (!att_server) break; 458 att_server->connection.authorized = sm_event_authorization_result_get_authorization_result(packet); 459 att_server_request_can_send_now(att_server); 460 break; 461 } 462 default: 463 break; 464 } 465 break; 466 #ifdef ENABLE_GATT_OVER_CLASSIC 467 case L2CAP_DATA_PACKET: 468 att_server = att_server_for_l2cap_cid(channel); 469 if (!att_server) break; 470 471 att_server_handle_att_pdu(att_server, packet, size); 472 break; 473 #endif 474 475 default: 476 break; 477 } 478 } 479 480 #ifdef ENABLE_LE_SIGNED_WRITE 481 static void att_signed_write_handle_cmac_result(uint8_t hash[8]){ 482 483 att_server_t * att_server = att_server_for_state(ATT_SERVER_W4_SIGNED_WRITE_VALIDATION); 484 if (!att_server) return; 485 486 uint8_t hash_flipped[8]; 487 reverse_64(hash, hash_flipped); 488 if (memcmp(hash_flipped, &att_server->request_buffer[att_server->request_size-8], 8)){ 489 log_info("ATT Signed Write, invalid signature"); 490 att_server->state = ATT_SERVER_IDLE; 491 return; 492 } 493 log_info("ATT Signed Write, valid signature"); 494 495 // update sequence number 496 uint32_t counter_packet = little_endian_read_32(att_server->request_buffer, att_server->request_size-12); 497 le_device_db_remote_counter_set(att_server->ir_le_device_db_index, counter_packet+1); 498 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 499 att_server_request_can_send_now(att_server); 500 } 501 #endif 502 503 // pre: att_server->state == ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED 504 // pre: can send now 505 // returns: 1 if packet was sent 506 static int att_server_process_validated_request(att_server_t * att_server){ 507 508 l2cap_reserve_packet_buffer(); 509 uint8_t * att_response_buffer = l2cap_get_outgoing_buffer(); 510 uint16_t att_response_size = att_handle_request(&att_server->connection, att_server->request_buffer, att_server->request_size, att_response_buffer); 511 512 #ifdef ENABLE_ATT_DELAYED_RESPONSE 513 if (att_response_size == ATT_READ_RESPONSE_PENDING || att_response_size == ATT_INTERNAL_WRITE_RESPONSE_PENDING){ 514 // update state 515 att_server->state = ATT_SERVER_RESPONSE_PENDING; 516 517 // callback with handle ATT_READ_RESPONSE_PENDING for reads 518 if (att_response_size == ATT_READ_RESPONSE_PENDING){ 519 att_server_client_read_callback(att_server->connection.con_handle, ATT_READ_RESPONSE_PENDING, 0, NULL, 0); 520 } 521 522 // free reserved buffer 523 l2cap_release_packet_buffer(); 524 return 0; 525 } 526 #endif 527 528 // intercept "insufficient authorization" for authenticated connections to allow for user authorization 529 if ((att_response_size >= 4) 530 && (att_response_buffer[0] == ATT_ERROR_RESPONSE) 531 && (att_response_buffer[4] == ATT_ERROR_INSUFFICIENT_AUTHORIZATION) 532 && (att_server->connection.authenticated)){ 533 534 switch (gap_authorization_state(att_server->connection.con_handle)){ 535 case AUTHORIZATION_UNKNOWN: 536 l2cap_release_packet_buffer(); 537 sm_request_pairing(att_server->connection.con_handle); 538 return 0; 539 case AUTHORIZATION_PENDING: 540 l2cap_release_packet_buffer(); 541 return 0; 542 default: 543 break; 544 } 545 } 546 547 att_server->state = ATT_SERVER_IDLE; 548 if (att_response_size == 0) { 549 l2cap_release_packet_buffer(); 550 return 0; 551 } 552 553 #ifdef ENABLE_GATT_OVER_CLASSIC 554 if (att_server->l2cap_cid != 0){ 555 l2cap_send_prepared(att_server->l2cap_cid, att_response_size); 556 } else 557 #endif 558 { 559 l2cap_send_prepared_connectionless(att_server->connection.con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, att_response_size); 560 } 561 562 // notify client about MTU exchange result 563 if (att_response_buffer[0] == ATT_EXCHANGE_MTU_RESPONSE){ 564 att_emit_mtu_event(att_server->connection.con_handle, att_server->connection.mtu); 565 } 566 return 1; 567 } 568 569 #ifdef ENABLE_ATT_DELAYED_RESPONSE 570 int att_server_response_ready(hci_con_handle_t con_handle){ 571 att_server_t * att_server = att_server_for_handle(con_handle); 572 if (!att_server) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 573 if (att_server->state != ATT_SERVER_RESPONSE_PENDING) return ERROR_CODE_COMMAND_DISALLOWED; 574 575 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 576 att_server_request_can_send_now(att_server); 577 return ERROR_CODE_SUCCESS; 578 } 579 #endif 580 581 static void att_run_for_context(att_server_t * att_server){ 582 switch (att_server->state){ 583 case ATT_SERVER_REQUEST_RECEIVED: 584 585 #ifdef ENABLE_GATT_OVER_CLASSIC 586 if (att_server->l2cap_cid != 0){ 587 // ok 588 } else 589 #endif 590 { 591 // wait until re-encryption as central is complete 592 if (gap_reconnect_security_setup_active(att_server->connection.con_handle)) break; 593 } 594 595 // wait until pairing is complete 596 if (att_server->pairing_active) break; 597 598 #ifdef ENABLE_LE_SIGNED_WRITE 599 if (att_server->request_buffer[0] == ATT_SIGNED_WRITE_COMMAND){ 600 log_info("ATT Signed Write!"); 601 if (!sm_cmac_ready()) { 602 log_info("ATT Signed Write, sm_cmac engine not ready. Abort"); 603 att_server->state = ATT_SERVER_IDLE; 604 return; 605 } 606 if (att_server->request_size < (3 + 12)) { 607 log_info("ATT Signed Write, request to short. Abort."); 608 att_server->state = ATT_SERVER_IDLE; 609 return; 610 } 611 if (att_server->ir_lookup_active){ 612 return; 613 } 614 if (att_server->ir_le_device_db_index < 0){ 615 log_info("ATT Signed Write, CSRK not available"); 616 att_server->state = ATT_SERVER_IDLE; 617 return; 618 } 619 620 // check counter 621 uint32_t counter_packet = little_endian_read_32(att_server->request_buffer, att_server->request_size-12); 622 uint32_t counter_db = le_device_db_remote_counter_get(att_server->ir_le_device_db_index); 623 log_info("ATT Signed Write, DB counter %"PRIu32", packet counter %"PRIu32, counter_db, counter_packet); 624 if (counter_packet < counter_db){ 625 log_info("ATT Signed Write, db reports higher counter, abort"); 626 att_server->state = ATT_SERVER_IDLE; 627 return; 628 } 629 630 // signature is { sequence counter, secure hash } 631 sm_key_t csrk; 632 le_device_db_remote_csrk_get(att_server->ir_le_device_db_index, csrk); 633 att_server->state = ATT_SERVER_W4_SIGNED_WRITE_VALIDATION; 634 log_info("Orig Signature: "); 635 log_info_hexdump( &att_server->request_buffer[att_server->request_size-8], 8); 636 uint16_t attribute_handle = little_endian_read_16(att_server->request_buffer, 1); 637 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); 638 return; 639 } 640 #endif 641 // move on 642 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 643 att_server_request_can_send_now(att_server); 644 break; 645 646 default: 647 break; 648 } 649 } 650 651 static int att_server_data_ready_for_phase(att_server_t * att_server, att_server_run_phase_t phase){ 652 switch (phase){ 653 case ATT_SERVER_RUN_PHASE_1_REQUESTS: 654 return att_server->state == ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 655 case ATT_SERVER_RUN_PHASE_2_INDICATIONS: 656 return (!btstack_linked_list_empty(&att_server->indication_requests) && att_server->value_indication_handle == 0); 657 case ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS: 658 return (!btstack_linked_list_empty(&att_server->notification_requests)); 659 } 660 // avoid warning 661 return 0; 662 } 663 664 static void att_server_trigger_send_for_phase(att_server_t * att_server, att_server_run_phase_t phase){ 665 btstack_context_callback_registration_t * client; 666 switch (phase){ 667 case ATT_SERVER_RUN_PHASE_1_REQUESTS: 668 att_server_process_validated_request(att_server); 669 break; 670 case ATT_SERVER_RUN_PHASE_2_INDICATIONS: 671 client = (btstack_context_callback_registration_t*) att_server->indication_requests; 672 btstack_linked_list_remove(&att_server->indication_requests, (btstack_linked_item_t *) client); 673 client->callback(client->context); 674 break; 675 case ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS: 676 client = (btstack_context_callback_registration_t*) att_server->notification_requests; 677 btstack_linked_list_remove(&att_server->notification_requests, (btstack_linked_item_t *) client); 678 client->callback(client->context); 679 break; 680 } 681 } 682 683 static void att_server_handle_can_send_now(void){ 684 685 hci_con_handle_t last_send_con_handle = HCI_CON_HANDLE_INVALID; 686 att_server_t * request_att_server = NULL; 687 int can_send_now = 1; 688 int phase_index; 689 690 for (phase_index = ATT_SERVER_RUN_PHASE_1_REQUESTS; phase_index <= ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS; phase_index++){ 691 att_server_run_phase_t phase = (att_server_run_phase_t) phase_index; 692 hci_con_handle_t skip_connections_until = att_server_last_can_send_now; 693 while (1){ 694 btstack_linked_list_iterator_t it; 695 hci_connections_get_iterator(&it); 696 while(btstack_linked_list_iterator_has_next(&it)){ 697 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 698 att_server_t * att_server = &connection->att_server; 699 700 int data_ready = att_server_data_ready_for_phase(att_server, phase); 701 702 // 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); 703 704 // skip until last sender found (which is also skipped) 705 if (skip_connections_until != HCI_CON_HANDLE_INVALID){ 706 if (data_ready && request_att_server == NULL){ 707 request_att_server = att_server; 708 } 709 if (skip_connections_until == att_server->connection.con_handle){ 710 skip_connections_until = HCI_CON_HANDLE_INVALID; 711 } 712 continue; 713 }; 714 715 if (data_ready){ 716 if (can_send_now){ 717 att_server_trigger_send_for_phase(att_server, phase); 718 last_send_con_handle = att_server->connection.con_handle; 719 can_send_now = att_server_can_send_packet(att_server); 720 data_ready = att_server_data_ready_for_phase(att_server, phase); 721 if (data_ready && request_att_server == NULL){ 722 request_att_server = att_server; 723 } 724 } else { 725 request_att_server = att_server; 726 break; 727 } 728 } 729 } 730 731 // stop skipping (handles disconnect by last send connection) 732 skip_connections_until = HCI_CON_HANDLE_INVALID; 733 734 // Exit loop, if we cannot send 735 if (!can_send_now) break; 736 737 // Exit loop, if we can send but there are also no further request 738 if (request_att_server == NULL) break; 739 740 // Finally, if we still can send and there are requests, just try again 741 request_att_server = NULL; 742 } 743 // update last send con handle for round robin 744 if (last_send_con_handle != HCI_CON_HANDLE_INVALID){ 745 att_server_last_can_send_now = last_send_con_handle; 746 } 747 } 748 749 if (request_att_server == NULL) return; 750 att_server_request_can_send_now(request_att_server); 751 } 752 753 static void att_server_handle_att_pdu(att_server_t * att_server, uint8_t * packet, uint16_t size){ 754 755 // handle value indication confirms 756 if (packet[0] == ATT_HANDLE_VALUE_CONFIRMATION && att_server->value_indication_handle){ 757 btstack_run_loop_remove_timer(&att_server->value_indication_timer); 758 uint16_t att_handle = att_server->value_indication_handle; 759 att_server->value_indication_handle = 0; 760 att_handle_value_indication_notify_client(0, att_server->connection.con_handle, att_handle); 761 att_server_request_can_send_now(att_server); 762 return; 763 } 764 765 // directly process command 766 // note: signed write cannot be handled directly as authentication needs to be verified 767 if (packet[0] == ATT_WRITE_COMMAND){ 768 att_handle_request(&att_server->connection, packet, size, 0); 769 return; 770 } 771 772 // check size 773 if (size > sizeof(att_server->request_buffer)) { 774 log_info("drop att pdu 0x%02x as size %u > att_server->request_buffer %u", packet[0], size, (int) sizeof(att_server->request_buffer)); 775 return; 776 } 777 778 #ifdef ENABLE_LE_SIGNED_WRITE 779 // abort signed write validation if a new request comes in (but finish previous signed write if possible) 780 if (att_server->state == ATT_SERVER_W4_SIGNED_WRITE_VALIDATION){ 781 if (packet[0] == ATT_SIGNED_WRITE_COMMAND){ 782 log_info("skip new signed write request as previous is in validation"); 783 return; 784 } else { 785 log_info("abort signed write validation to process new request"); 786 att_server->state = ATT_SERVER_IDLE; 787 } 788 } 789 #endif 790 // last request still in processing? 791 if (att_server->state != ATT_SERVER_IDLE){ 792 log_info("skip att pdu 0x%02x as server not idle (state %u)", packet[0], att_server->state); 793 return; 794 } 795 796 // store request 797 att_server->state = ATT_SERVER_REQUEST_RECEIVED; 798 att_server->request_size = size; 799 memcpy(att_server->request_buffer, packet, size); 800 801 att_run_for_context(att_server); 802 } 803 804 static void att_packet_handler(uint8_t packet_type, uint16_t handle, uint8_t *packet, uint16_t size){ 805 att_server_t * att_server; 806 807 switch (packet_type){ 808 case HCI_EVENT_PACKET: 809 switch (packet[0]){ 810 case L2CAP_EVENT_CAN_SEND_NOW: 811 att_server_handle_can_send_now(); 812 break; 813 case ATT_EVENT_MTU_EXCHANGE_COMPLETE: 814 // GATT client has negotiated the mtu for this connection 815 att_server = att_server_for_handle(handle); 816 if (!att_server) break; 817 att_server->connection.mtu = little_endian_read_16(packet, 4); 818 break; 819 default: 820 break; 821 } 822 break; 823 824 case ATT_DATA_PACKET: 825 log_debug("ATT Packet, handle 0x%04x", handle); 826 att_server = att_server_for_handle(handle); 827 if (!att_server) break; 828 829 att_server_handle_att_pdu(att_server, packet, size); 830 break; 831 } 832 } 833 834 // --------------------- 835 // persistent CCC writes 836 static uint32_t att_server_persistent_ccc_tag_for_index(uint8_t index){ 837 return 'B' << 24 | 'T' << 16 | 'C' << 8 | index; 838 } 839 840 static void att_server_persistent_ccc_write(hci_con_handle_t con_handle, uint16_t att_handle, uint16_t value){ 841 // lookup att_server instance 842 att_server_t * att_server = att_server_for_handle(con_handle); 843 if (!att_server) return; 844 int le_device_index = att_server->ir_le_device_db_index; 845 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); 846 847 // check if bonded 848 if (le_device_index < 0) return; 849 850 // get btstack_tlv 851 const btstack_tlv_t * tlv_impl = NULL; 852 void * tlv_context; 853 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 854 if (!tlv_impl) return; 855 856 // update ccc tag 857 int index; 858 uint32_t highest_seq_nr = 0; 859 uint32_t lowest_seq_nr = 0; 860 uint32_t tag_for_lowest_seq_nr = 0; 861 uint32_t tag_for_empty = 0; 862 persistent_ccc_entry_t entry; 863 for (index=0;index<NVN_NUM_GATT_SERVER_CCC;index++){ 864 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 865 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 866 867 // empty/invalid tag 868 if (len != sizeof(persistent_ccc_entry_t)){ 869 tag_for_empty = tag; 870 continue; 871 } 872 // update highest seq nr 873 if (entry.seq_nr > highest_seq_nr){ 874 highest_seq_nr = entry.seq_nr; 875 } 876 // find entry with lowest seq nr 877 if ((tag_for_lowest_seq_nr == 0) || (entry.seq_nr < lowest_seq_nr)){ 878 tag_for_lowest_seq_nr = tag; 879 lowest_seq_nr = entry.seq_nr; 880 } 881 882 if (entry.device_index != le_device_index) continue; 883 if (entry.att_handle != att_handle) continue; 884 885 // found matching entry 886 if (value){ 887 // update 888 if (entry.value == value) { 889 log_info("CCC Index %u: Up-to-date", index); 890 return; 891 } 892 entry.value = value; 893 entry.seq_nr = highest_seq_nr + 1; 894 log_info("CCC Index %u: Store", index); 895 tlv_impl->store_tag(tlv_context, tag, (const uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 896 } else { 897 // delete 898 log_info("CCC Index %u: Delete", index); 899 tlv_impl->delete_tag(tlv_context, tag); 900 } 901 return; 902 } 903 904 log_info("tag_for_empy %"PRIx32", tag_for_lowest_seq_nr %"PRIx32, tag_for_empty, tag_for_lowest_seq_nr); 905 906 if (value == 0){ 907 // done 908 return; 909 } 910 911 uint32_t tag_to_use = 0; 912 if (tag_for_empty){ 913 tag_to_use = tag_for_empty; 914 } else if (tag_for_lowest_seq_nr){ 915 tag_to_use = tag_for_lowest_seq_nr; 916 } else { 917 // should not happen 918 return; 919 } 920 // store ccc tag 921 entry.seq_nr = highest_seq_nr + 1; 922 entry.device_index = le_device_index; 923 entry.att_handle = att_handle; 924 entry.value = value; 925 tlv_impl->store_tag(tlv_context, tag_to_use, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 926 } 927 928 static void att_server_persistent_ccc_clear(att_server_t * att_server){ 929 if (!att_server) return; 930 int le_device_index = att_server->ir_le_device_db_index; 931 log_info("Clear CCC values of remote %s, le device id %d", bd_addr_to_str(att_server->peer_address), le_device_index); 932 // check if bonded 933 if (le_device_index < 0) return; 934 // get btstack_tlv 935 const btstack_tlv_t * tlv_impl = NULL; 936 void * tlv_context; 937 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 938 if (!tlv_impl) return; 939 // get all ccc tag 940 int index; 941 persistent_ccc_entry_t entry; 942 for (index=0;index<NVN_NUM_GATT_SERVER_CCC;index++){ 943 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 944 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 945 if (len != sizeof(persistent_ccc_entry_t)) continue; 946 if (entry.device_index != le_device_index) continue; 947 // delete entry 948 log_info("CCC Index %u: Delete", index); 949 tlv_impl->delete_tag(tlv_context, tag); 950 } 951 } 952 953 static void att_server_persistent_ccc_restore(att_server_t * att_server){ 954 if (!att_server) return; 955 int le_device_index = att_server->ir_le_device_db_index; 956 log_info("Restore CCC values of remote %s, le device id %d", bd_addr_to_str(att_server->peer_address), le_device_index); 957 // check if bonded 958 if (le_device_index < 0) return; 959 // get btstack_tlv 960 const btstack_tlv_t * tlv_impl = NULL; 961 void * tlv_context; 962 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 963 if (!tlv_impl) return; 964 // get all ccc tag 965 int index; 966 persistent_ccc_entry_t entry; 967 for (index=0;index<NVN_NUM_GATT_SERVER_CCC;index++){ 968 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 969 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 970 if (len != sizeof(persistent_ccc_entry_t)) continue; 971 if (entry.device_index != le_device_index) continue; 972 // simulate write callback 973 uint16_t attribute_handle = entry.att_handle; 974 uint8_t value[2]; 975 little_endian_store_16(value, 0, entry.value); 976 att_write_callback_t callback = att_server_write_callback_for_handle(attribute_handle); 977 if (!callback) continue; 978 log_info("CCC Index %u: Set Attribute handle 0x%04x to value 0x%04x", index, attribute_handle, entry.value ); 979 (*callback)(att_server->connection.con_handle, attribute_handle, ATT_TRANSACTION_MODE_NONE, 0, value, sizeof(value)); 980 } 981 } 982 983 // persistent CCC writes 984 // --------------------- 985 986 // gatt service management 987 static att_service_handler_t * att_service_handler_for_handle(uint16_t handle){ 988 btstack_linked_list_iterator_t it; 989 btstack_linked_list_iterator_init(&it, &service_handlers); 990 while (btstack_linked_list_iterator_has_next(&it)){ 991 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 992 if (handler->start_handle > handle) continue; 993 if (handler->end_handle < handle) continue; 994 return handler; 995 } 996 return NULL; 997 } 998 static att_read_callback_t att_server_read_callback_for_handle(uint16_t handle){ 999 att_service_handler_t * handler = att_service_handler_for_handle(handle); 1000 if (handler) return handler->read_callback; 1001 return att_server_client_read_callback; 1002 } 1003 1004 static att_write_callback_t att_server_write_callback_for_handle(uint16_t handle){ 1005 att_service_handler_t * handler = att_service_handler_for_handle(handle); 1006 if (handler) return handler->write_callback; 1007 return att_server_client_write_callback; 1008 } 1009 1010 static btstack_packet_handler_t att_server_packet_handler_for_handle(uint16_t handle){ 1011 att_service_handler_t * handler = att_service_handler_for_handle(handle); 1012 if (handler) return handler->packet_handler; 1013 return att_client_packet_handler; 1014 } 1015 1016 static void att_notify_write_callbacks(hci_con_handle_t con_handle, uint16_t transaction_mode){ 1017 // notify all callbacks 1018 btstack_linked_list_iterator_t it; 1019 btstack_linked_list_iterator_init(&it, &service_handlers); 1020 while (btstack_linked_list_iterator_has_next(&it)){ 1021 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 1022 if (!handler->write_callback) continue; 1023 (*handler->write_callback)(con_handle, 0, transaction_mode, 0, NULL, 0); 1024 } 1025 if (!att_server_client_write_callback) return; 1026 (*att_server_client_write_callback)(con_handle, 0, transaction_mode, 0, NULL, 0); 1027 } 1028 1029 // returns first reported error or 0 1030 static uint8_t att_validate_prepared_write(hci_con_handle_t con_handle){ 1031 btstack_linked_list_iterator_t it; 1032 btstack_linked_list_iterator_init(&it, &service_handlers); 1033 while (btstack_linked_list_iterator_has_next(&it)){ 1034 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 1035 if (!handler->write_callback) continue; 1036 uint8_t error_code = (*handler->write_callback)(con_handle, 0, ATT_TRANSACTION_MODE_VALIDATE, 0, NULL, 0); 1037 if (error_code) return error_code; 1038 } 1039 if (!att_server_client_write_callback) return 0; 1040 return (*att_server_client_write_callback)(con_handle, 0, ATT_TRANSACTION_MODE_VALIDATE, 0, NULL, 0); 1041 } 1042 1043 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){ 1044 att_read_callback_t callback = att_server_read_callback_for_handle(attribute_handle); 1045 if (!callback) return 0; 1046 return (*callback)(con_handle, attribute_handle, offset, buffer, buffer_size); 1047 } 1048 1049 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){ 1050 switch (transaction_mode){ 1051 case ATT_TRANSACTION_MODE_VALIDATE: 1052 return att_validate_prepared_write(con_handle); 1053 case ATT_TRANSACTION_MODE_EXECUTE: 1054 case ATT_TRANSACTION_MODE_CANCEL: 1055 att_notify_write_callbacks(con_handle, transaction_mode); 1056 return 0; 1057 default: 1058 break; 1059 } 1060 1061 // track CCC writes 1062 if (att_is_persistent_ccc(attribute_handle) && offset == 0 && buffer_size == 2){ 1063 att_server_persistent_ccc_write(con_handle, attribute_handle, little_endian_read_16(buffer, 0)); 1064 } 1065 1066 att_write_callback_t callback = att_server_write_callback_for_handle(attribute_handle); 1067 if (!callback) return 0; 1068 return (*callback)(con_handle, attribute_handle, transaction_mode, offset, buffer, buffer_size); 1069 } 1070 1071 /** 1072 * @brief register read/write callbacks for specific handle range 1073 * @param att_service_handler_t 1074 */ 1075 void att_server_register_service_handler(att_service_handler_t * handler){ 1076 if (att_service_handler_for_handle(handler->start_handle) || 1077 att_service_handler_for_handle(handler->end_handle)){ 1078 log_error("handler for range 0x%04x-0x%04x already registered", handler->start_handle, handler->end_handle); 1079 return; 1080 } 1081 btstack_linked_list_add(&service_handlers, (btstack_linked_item_t*) handler); 1082 } 1083 1084 void att_server_init(uint8_t const * db, att_read_callback_t read_callback, att_write_callback_t write_callback){ 1085 1086 // store callbacks 1087 att_server_client_read_callback = read_callback; 1088 att_server_client_write_callback = write_callback; 1089 1090 // register for HCI Events 1091 hci_event_callback_registration.callback = &att_event_packet_handler; 1092 hci_add_event_handler(&hci_event_callback_registration); 1093 1094 // register for SM events 1095 sm_event_callback_registration.callback = &att_event_packet_handler; 1096 sm_add_event_handler(&sm_event_callback_registration); 1097 1098 // and L2CAP ATT Server PDUs 1099 att_dispatch_register_server(att_packet_handler); 1100 1101 #ifdef ENABLE_GATT_OVER_CLASSIC 1102 // setup l2cap service 1103 l2cap_register_service(&att_event_packet_handler, PSM_ATT, 0xffff, LEVEL_2); 1104 #endif 1105 1106 att_set_db(db); 1107 att_set_read_callback(att_server_read_callback); 1108 att_set_write_callback(att_server_write_callback); 1109 } 1110 1111 void att_server_register_packet_handler(btstack_packet_handler_t handler){ 1112 att_client_packet_handler = handler; 1113 } 1114 1115 1116 // to be deprecated 1117 int att_server_can_send_packet_now(hci_con_handle_t con_handle){ 1118 att_server_t * att_server = att_server_for_handle(con_handle); 1119 if (!att_server) return 0; 1120 return att_server_can_send_packet(att_server); 1121 } 1122 1123 int att_server_register_can_send_now_callback(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 1124 return att_server_request_to_send_notification(callback_registration, con_handle); 1125 } 1126 1127 void att_server_request_can_send_now_event(hci_con_handle_t con_handle){ 1128 att_client_waiting_for_can_send_registration.callback = &att_emit_can_send_now_event; 1129 att_server_request_to_send_notification(&att_client_waiting_for_can_send_registration, con_handle); 1130 } 1131 // end of deprecated 1132 1133 int att_server_request_to_send_notification(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 1134 att_server_t * att_server = att_server_for_handle(con_handle); 1135 if (!att_server) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1136 btstack_linked_list_add_tail(&att_server->notification_requests, (btstack_linked_item_t*) callback_registration); 1137 att_server_request_can_send_now(att_server); 1138 return ERROR_CODE_SUCCESS; 1139 } 1140 1141 int att_server_request_to_send_indication(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 1142 att_server_t * att_server = att_server_for_handle(con_handle); 1143 if (!att_server) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1144 btstack_linked_list_add_tail(&att_server->indication_requests, (btstack_linked_item_t*) callback_registration); 1145 att_server_request_can_send_now(att_server); 1146 return ERROR_CODE_SUCCESS; 1147 } 1148 1149 int att_server_notify(hci_con_handle_t con_handle, uint16_t attribute_handle, const uint8_t *value, uint16_t value_len){ 1150 att_server_t * att_server = att_server_for_handle(con_handle); 1151 if (!att_server) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1152 if (!att_server_can_send_packet(att_server)) return BTSTACK_ACL_BUFFERS_FULL; 1153 1154 l2cap_reserve_packet_buffer(); 1155 uint8_t * packet_buffer = l2cap_get_outgoing_buffer(); 1156 uint16_t size = att_prepare_handle_value_notification(&att_server->connection, attribute_handle, value, value_len, packet_buffer); 1157 return l2cap_send_prepared_connectionless(att_server->connection.con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, size); 1158 } 1159 1160 int att_server_indicate(hci_con_handle_t con_handle, uint16_t attribute_handle, const uint8_t *value, uint16_t value_len){ 1161 att_server_t * att_server = att_server_for_handle(con_handle); 1162 if (!att_server) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1163 1164 if (att_server->value_indication_handle) return ATT_HANDLE_VALUE_INDICATION_IN_PROGRESS; 1165 if (!att_server_can_send_packet(att_server)) return BTSTACK_ACL_BUFFERS_FULL; 1166 1167 // track indication 1168 att_server->value_indication_handle = attribute_handle; 1169 btstack_run_loop_set_timer_handler(&att_server->value_indication_timer, att_handle_value_indication_timeout); 1170 btstack_run_loop_set_timer(&att_server->value_indication_timer, ATT_TRANSACTION_TIMEOUT_MS); 1171 btstack_run_loop_add_timer(&att_server->value_indication_timer); 1172 1173 l2cap_reserve_packet_buffer(); 1174 uint8_t * packet_buffer = l2cap_get_outgoing_buffer(); 1175 uint16_t size = att_prepare_handle_value_indication(&att_server->connection, attribute_handle, value, value_len, packet_buffer); 1176 l2cap_send_prepared_connectionless(att_server->connection.con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, size); 1177 return 0; 1178 } 1179 1180 uint16_t att_server_get_mtu(hci_con_handle_t con_handle){ 1181 att_server_t * att_server = att_server_for_handle(con_handle); 1182 if (!att_server) return 0; 1183 return att_server->connection.mtu; 1184 } 1185