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_ACL; 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 } 292 293 log_info("Connection opened %s, l2cap cid %04x, mtu %u", bd_addr_to_str(address), att_server->l2cap_cid, att_server->connection.mtu); 294 295 // update security params 296 att_server->connection.encryption_key_size = gap_encryption_key_size(con_handle); 297 att_server->connection.authenticated = gap_authenticated(con_handle); 298 att_server->connection.secure_connection = gap_secure_connection(con_handle); 299 log_info("encrypted key size %u, authenticated %u, secure connection %u", 300 att_server->connection.encryption_key_size, att_server->connection.authenticated, att_server->connection.secure_connection); 301 302 // notify connection opened 303 att_emit_connected_event(att_server); 304 305 // restore persisten ccc if encrypted 306 if ( gap_security_level(con_handle) >= LEVEL_2){ 307 att_server_persistent_ccc_restore(att_server); 308 } 309 // TODO: what to do about le device db? 310 att_server->pairing_active = 0; 311 break; 312 case L2CAP_EVENT_CAN_SEND_NOW: 313 att_server_handle_can_send_now(); 314 break; 315 316 #endif 317 case HCI_EVENT_LE_META: 318 switch (packet[2]) { 319 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 320 con_handle = little_endian_read_16(packet, 4); 321 att_server = att_server_for_handle(con_handle); 322 if (!att_server) break; 323 // store connection info 324 att_server->peer_addr_type = packet[7]; 325 reverse_bd_addr(&packet[8], att_server->peer_address); 326 att_server->connection.con_handle = con_handle; 327 // reset connection properties 328 att_server->state = ATT_SERVER_IDLE; 329 att_server->connection.mtu = ATT_DEFAULT_MTU; 330 att_server->connection.max_mtu = l2cap_max_le_mtu(); 331 if (att_server->connection.max_mtu > ATT_REQUEST_BUFFER_SIZE){ 332 att_server->connection.max_mtu = ATT_REQUEST_BUFFER_SIZE; 333 } 334 att_server->connection.encryption_key_size = 0; 335 att_server->connection.authenticated = 0; 336 att_server->connection.authorized = 0; 337 // workaround: identity resolving can already be complete, at least store result 338 att_server->ir_le_device_db_index = sm_le_device_index(con_handle); 339 att_server->ir_lookup_active = 0; 340 att_server->pairing_active = 0; 341 // notify all - old 342 att_emit_event_to_all(packet, size); 343 // notify all - new 344 att_emit_connected_event(att_server); 345 break; 346 347 default: 348 break; 349 } 350 break; 351 352 case HCI_EVENT_ENCRYPTION_CHANGE: 353 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 354 // check handle 355 con_handle = little_endian_read_16(packet, 3); 356 att_server = att_server_for_handle(con_handle); 357 if (!att_server) break; 358 if (gap_get_connection_type(con_handle) != GAP_CONNECTION_LE) break; 359 // update security params 360 att_server->connection.encryption_key_size = gap_encryption_key_size(con_handle); 361 att_server->connection.authenticated = gap_authenticated(con_handle); 362 att_server->connection.secure_connection = gap_secure_connection(con_handle); 363 log_info("encrypted key size %u, authenticated %u, secure connection %u", 364 att_server->connection.encryption_key_size, att_server->connection.authenticated, att_server->connection.secure_connection); 365 if (hci_event_packet_get_type(packet) == HCI_EVENT_ENCRYPTION_CHANGE){ 366 // restore CCC values when encrypted for LE Connections 367 if (hci_event_encryption_change_get_encryption_enabled(packet)){ 368 att_server_persistent_ccc_restore(att_server); 369 } 370 } 371 att_run_for_context(att_server); 372 break; 373 374 case HCI_EVENT_DISCONNECTION_COMPLETE: 375 // check handle 376 con_handle = hci_event_disconnection_complete_get_connection_handle(packet); 377 att_server = att_server_for_handle(con_handle); 378 if (!att_server) break; 379 att_clear_transaction_queue(&att_server->connection); 380 att_server->connection.con_handle = 0; 381 att_server->pairing_active = 0; 382 att_server->state = ATT_SERVER_IDLE; 383 if (att_server->value_indication_handle){ 384 btstack_run_loop_remove_timer(&att_server->value_indication_timer); 385 uint16_t att_handle = att_server->value_indication_handle; 386 att_server->value_indication_handle = 0; // reset error state 387 att_handle_value_indication_notify_client(ATT_HANDLE_VALUE_INDICATION_DISCONNECT, att_server->connection.con_handle, att_handle); 388 } 389 // notify all - new 390 att_emit_disconnected_event(con_handle); 391 // notify all - old 392 att_emit_event_to_all(packet, size); 393 break; 394 395 // Identity Resolving 396 case SM_EVENT_IDENTITY_RESOLVING_STARTED: 397 con_handle = sm_event_identity_resolving_started_get_handle(packet); 398 att_server = att_server_for_handle(con_handle); 399 if (!att_server) break; 400 log_info("SM_EVENT_IDENTITY_RESOLVING_STARTED"); 401 att_server->ir_lookup_active = 1; 402 break; 403 case SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED: 404 con_handle = sm_event_identity_created_get_handle(packet); 405 att_server = att_server_for_handle(con_handle); 406 if (!att_server) return; 407 att_server->ir_lookup_active = 0; 408 att_server->ir_le_device_db_index = sm_event_identity_resolving_succeeded_get_index(packet); 409 log_info("SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED"); 410 att_run_for_context(att_server); 411 break; 412 case SM_EVENT_IDENTITY_RESOLVING_FAILED: 413 con_handle = sm_event_identity_resolving_failed_get_handle(packet); 414 att_server = att_server_for_handle(con_handle); 415 if (!att_server) break; 416 log_info("SM_EVENT_IDENTITY_RESOLVING_FAILED"); 417 att_server->ir_lookup_active = 0; 418 att_server->ir_le_device_db_index = -1; 419 att_run_for_context(att_server); 420 break; 421 422 // Pairing started - delete stored CCC values 423 // - assumes pairing indicates either new device or re-pairing, in both cases there should be no stored CCC values 424 // - assumes that all events have the con handle as the first field 425 case SM_EVENT_JUST_WORKS_REQUEST: 426 case SM_EVENT_PASSKEY_DISPLAY_NUMBER: 427 case SM_EVENT_PASSKEY_INPUT_NUMBER: 428 case SM_EVENT_NUMERIC_COMPARISON_REQUEST: 429 con_handle = sm_event_just_works_request_get_handle(packet); 430 att_server = att_server_for_handle(con_handle); 431 if (!att_server) break; 432 att_server->pairing_active = 1; 433 log_info("SM Pairing started"); 434 if (att_server->ir_le_device_db_index < 0) break; 435 att_server_persistent_ccc_clear(att_server); 436 // index not valid anymore 437 att_server->ir_le_device_db_index = -1; 438 break; 439 440 // Bonding completed 441 case SM_EVENT_IDENTITY_CREATED: 442 con_handle = sm_event_identity_created_get_handle(packet); 443 att_server = att_server_for_handle(con_handle); 444 if (!att_server) return; 445 att_server->pairing_active = 0; 446 att_server->ir_le_device_db_index = sm_event_identity_created_get_index(packet); 447 att_run_for_context(att_server); 448 break; 449 450 // Pairing complete (with/without bonding=storing of pairing information) 451 case SM_EVENT_PAIRING_COMPLETE: 452 con_handle = sm_event_pairing_complete_get_handle(packet); 453 att_server = att_server_for_handle(con_handle); 454 if (!att_server) return; 455 att_server->pairing_active = 0; 456 att_run_for_context(att_server); 457 break; 458 459 // Authorization 460 case SM_EVENT_AUTHORIZATION_RESULT: { 461 con_handle = sm_event_authorization_result_get_handle(packet); 462 att_server = att_server_for_handle(con_handle); 463 if (!att_server) break; 464 att_server->connection.authorized = sm_event_authorization_result_get_authorization_result(packet); 465 att_server_request_can_send_now(att_server); 466 break; 467 } 468 default: 469 break; 470 } 471 break; 472 #ifdef ENABLE_GATT_OVER_CLASSIC 473 case L2CAP_DATA_PACKET: 474 att_server = att_server_for_l2cap_cid(channel); 475 if (!att_server) break; 476 477 att_server_handle_att_pdu(att_server, packet, size); 478 break; 479 #endif 480 481 default: 482 break; 483 } 484 } 485 486 #ifdef ENABLE_LE_SIGNED_WRITE 487 static void att_signed_write_handle_cmac_result(uint8_t hash[8]){ 488 489 att_server_t * att_server = att_server_for_state(ATT_SERVER_W4_SIGNED_WRITE_VALIDATION); 490 if (!att_server) return; 491 492 uint8_t hash_flipped[8]; 493 reverse_64(hash, hash_flipped); 494 if (memcmp(hash_flipped, &att_server->request_buffer[att_server->request_size-8], 8)){ 495 log_info("ATT Signed Write, invalid signature"); 496 att_server->state = ATT_SERVER_IDLE; 497 return; 498 } 499 log_info("ATT Signed Write, valid signature"); 500 501 // update sequence number 502 uint32_t counter_packet = little_endian_read_32(att_server->request_buffer, att_server->request_size-12); 503 le_device_db_remote_counter_set(att_server->ir_le_device_db_index, counter_packet+1); 504 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 505 att_server_request_can_send_now(att_server); 506 } 507 #endif 508 509 // pre: att_server->state == ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED 510 // pre: can send now 511 // returns: 1 if packet was sent 512 static int att_server_process_validated_request(att_server_t * att_server){ 513 514 l2cap_reserve_packet_buffer(); 515 uint8_t * att_response_buffer = l2cap_get_outgoing_buffer(); 516 uint16_t att_response_size = att_handle_request(&att_server->connection, att_server->request_buffer, att_server->request_size, att_response_buffer); 517 518 #ifdef ENABLE_ATT_DELAYED_RESPONSE 519 if ((att_response_size == ATT_READ_RESPONSE_PENDING) || (att_response_size == ATT_INTERNAL_WRITE_RESPONSE_PENDING)){ 520 // update state 521 att_server->state = ATT_SERVER_RESPONSE_PENDING; 522 523 // callback with handle ATT_READ_RESPONSE_PENDING for reads 524 if (att_response_size == ATT_READ_RESPONSE_PENDING){ 525 att_server_client_read_callback(att_server->connection.con_handle, ATT_READ_RESPONSE_PENDING, 0, NULL, 0); 526 } 527 528 // free reserved buffer 529 l2cap_release_packet_buffer(); 530 return 0; 531 } 532 #endif 533 534 // intercept "insufficient authorization" for authenticated connections to allow for user authorization 535 if ((att_response_size >= 4) 536 && (att_response_buffer[0] == ATT_ERROR_RESPONSE) 537 && (att_response_buffer[4] == ATT_ERROR_INSUFFICIENT_AUTHORIZATION) 538 && (att_server->connection.authenticated)){ 539 540 switch (gap_authorization_state(att_server->connection.con_handle)){ 541 case AUTHORIZATION_UNKNOWN: 542 l2cap_release_packet_buffer(); 543 sm_request_pairing(att_server->connection.con_handle); 544 return 0; 545 case AUTHORIZATION_PENDING: 546 l2cap_release_packet_buffer(); 547 return 0; 548 default: 549 break; 550 } 551 } 552 553 att_server->state = ATT_SERVER_IDLE; 554 if (att_response_size == 0) { 555 l2cap_release_packet_buffer(); 556 return 0; 557 } 558 559 #ifdef ENABLE_GATT_OVER_CLASSIC 560 if (att_server->l2cap_cid != 0){ 561 l2cap_send_prepared(att_server->l2cap_cid, att_response_size); 562 } else 563 #endif 564 { 565 l2cap_send_prepared_connectionless(att_server->connection.con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, att_response_size); 566 } 567 568 // notify client about MTU exchange result 569 if (att_response_buffer[0] == ATT_EXCHANGE_MTU_RESPONSE){ 570 att_emit_mtu_event(att_server->connection.con_handle, att_server->connection.mtu); 571 } 572 return 1; 573 } 574 575 #ifdef ENABLE_ATT_DELAYED_RESPONSE 576 int att_server_response_ready(hci_con_handle_t con_handle){ 577 att_server_t * att_server = att_server_for_handle(con_handle); 578 if (!att_server) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 579 if (att_server->state != ATT_SERVER_RESPONSE_PENDING) return ERROR_CODE_COMMAND_DISALLOWED; 580 581 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 582 att_server_request_can_send_now(att_server); 583 return ERROR_CODE_SUCCESS; 584 } 585 #endif 586 587 static void att_run_for_context(att_server_t * att_server){ 588 switch (att_server->state){ 589 case ATT_SERVER_REQUEST_RECEIVED: 590 591 #ifdef ENABLE_GATT_OVER_CLASSIC 592 if (att_server->l2cap_cid != 0){ 593 // ok 594 } else 595 #endif 596 { 597 // wait until re-encryption as central is complete 598 if (gap_reconnect_security_setup_active(att_server->connection.con_handle)) break; 599 } 600 601 // wait until pairing is complete 602 if (att_server->pairing_active) break; 603 604 #ifdef ENABLE_LE_SIGNED_WRITE 605 if (att_server->request_buffer[0] == ATT_SIGNED_WRITE_COMMAND){ 606 log_info("ATT Signed Write!"); 607 if (!sm_cmac_ready()) { 608 log_info("ATT Signed Write, sm_cmac engine not ready. Abort"); 609 att_server->state = ATT_SERVER_IDLE; 610 return; 611 } 612 if (att_server->request_size < (3 + 12)) { 613 log_info("ATT Signed Write, request to short. Abort."); 614 att_server->state = ATT_SERVER_IDLE; 615 return; 616 } 617 if (att_server->ir_lookup_active){ 618 return; 619 } 620 if (att_server->ir_le_device_db_index < 0){ 621 log_info("ATT Signed Write, CSRK not available"); 622 att_server->state = ATT_SERVER_IDLE; 623 return; 624 } 625 626 // check counter 627 uint32_t counter_packet = little_endian_read_32(att_server->request_buffer, att_server->request_size-12); 628 uint32_t counter_db = le_device_db_remote_counter_get(att_server->ir_le_device_db_index); 629 log_info("ATT Signed Write, DB counter %"PRIu32", packet counter %"PRIu32, counter_db, counter_packet); 630 if (counter_packet < counter_db){ 631 log_info("ATT Signed Write, db reports higher counter, abort"); 632 att_server->state = ATT_SERVER_IDLE; 633 return; 634 } 635 636 // signature is { sequence counter, secure hash } 637 sm_key_t csrk; 638 le_device_db_remote_csrk_get(att_server->ir_le_device_db_index, csrk); 639 att_server->state = ATT_SERVER_W4_SIGNED_WRITE_VALIDATION; 640 log_info("Orig Signature: "); 641 log_info_hexdump( &att_server->request_buffer[att_server->request_size-8], 8); 642 uint16_t attribute_handle = little_endian_read_16(att_server->request_buffer, 1); 643 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); 644 return; 645 } 646 #endif 647 // move on 648 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 649 att_server_request_can_send_now(att_server); 650 break; 651 652 default: 653 break; 654 } 655 } 656 657 static int att_server_data_ready_for_phase(att_server_t * att_server, att_server_run_phase_t phase){ 658 switch (phase){ 659 case ATT_SERVER_RUN_PHASE_1_REQUESTS: 660 return att_server->state == ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 661 case ATT_SERVER_RUN_PHASE_2_INDICATIONS: 662 return (!btstack_linked_list_empty(&att_server->indication_requests) && (att_server->value_indication_handle == 0)); 663 case ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS: 664 return (!btstack_linked_list_empty(&att_server->notification_requests)); 665 } 666 // avoid warning 667 return 0; 668 } 669 670 static void att_server_trigger_send_for_phase(att_server_t * att_server, att_server_run_phase_t phase){ 671 btstack_context_callback_registration_t * client; 672 switch (phase){ 673 case ATT_SERVER_RUN_PHASE_1_REQUESTS: 674 att_server_process_validated_request(att_server); 675 break; 676 case ATT_SERVER_RUN_PHASE_2_INDICATIONS: 677 client = (btstack_context_callback_registration_t*) att_server->indication_requests; 678 btstack_linked_list_remove(&att_server->indication_requests, (btstack_linked_item_t *) client); 679 client->callback(client->context); 680 break; 681 case ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS: 682 client = (btstack_context_callback_registration_t*) att_server->notification_requests; 683 btstack_linked_list_remove(&att_server->notification_requests, (btstack_linked_item_t *) client); 684 client->callback(client->context); 685 break; 686 } 687 } 688 689 static void att_server_handle_can_send_now(void){ 690 691 hci_con_handle_t last_send_con_handle = HCI_CON_HANDLE_INVALID; 692 att_server_t * request_att_server = NULL; 693 int can_send_now = 1; 694 int phase_index; 695 696 for (phase_index = ATT_SERVER_RUN_PHASE_1_REQUESTS; phase_index <= ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS; phase_index++){ 697 att_server_run_phase_t phase = (att_server_run_phase_t) phase_index; 698 hci_con_handle_t skip_connections_until = att_server_last_can_send_now; 699 while (1){ 700 btstack_linked_list_iterator_t it; 701 hci_connections_get_iterator(&it); 702 while(btstack_linked_list_iterator_has_next(&it)){ 703 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 704 att_server_t * att_server = &connection->att_server; 705 706 int data_ready = att_server_data_ready_for_phase(att_server, phase); 707 708 // 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); 709 710 // skip until last sender found (which is also skipped) 711 if (skip_connections_until != HCI_CON_HANDLE_INVALID){ 712 if (data_ready && (request_att_server == NULL)){ 713 request_att_server = att_server; 714 } 715 if (skip_connections_until == att_server->connection.con_handle){ 716 skip_connections_until = HCI_CON_HANDLE_INVALID; 717 } 718 continue; 719 }; 720 721 if (data_ready){ 722 if (can_send_now){ 723 att_server_trigger_send_for_phase(att_server, phase); 724 last_send_con_handle = att_server->connection.con_handle; 725 can_send_now = att_server_can_send_packet(att_server); 726 data_ready = att_server_data_ready_for_phase(att_server, phase); 727 if (data_ready && (request_att_server == NULL)){ 728 request_att_server = att_server; 729 } 730 } else { 731 request_att_server = att_server; 732 break; 733 } 734 } 735 } 736 737 // stop skipping (handles disconnect by last send connection) 738 skip_connections_until = HCI_CON_HANDLE_INVALID; 739 740 // Exit loop, if we cannot send 741 if (!can_send_now) break; 742 743 // Exit loop, if we can send but there are also no further request 744 if (request_att_server == NULL) break; 745 746 // Finally, if we still can send and there are requests, just try again 747 request_att_server = NULL; 748 } 749 // update last send con handle for round robin 750 if (last_send_con_handle != HCI_CON_HANDLE_INVALID){ 751 att_server_last_can_send_now = last_send_con_handle; 752 } 753 } 754 755 if (request_att_server == NULL) return; 756 att_server_request_can_send_now(request_att_server); 757 } 758 759 static void att_server_handle_att_pdu(att_server_t * att_server, uint8_t * packet, uint16_t size){ 760 761 // handle value indication confirms 762 if ((packet[0] == ATT_HANDLE_VALUE_CONFIRMATION) && att_server->value_indication_handle){ 763 btstack_run_loop_remove_timer(&att_server->value_indication_timer); 764 uint16_t att_handle = att_server->value_indication_handle; 765 att_server->value_indication_handle = 0; 766 att_handle_value_indication_notify_client(0, att_server->connection.con_handle, att_handle); 767 att_server_request_can_send_now(att_server); 768 return; 769 } 770 771 // directly process command 772 // note: signed write cannot be handled directly as authentication needs to be verified 773 if (packet[0] == ATT_WRITE_COMMAND){ 774 att_handle_request(&att_server->connection, packet, size, 0); 775 return; 776 } 777 778 // check size 779 if (size > sizeof(att_server->request_buffer)) { 780 log_info("drop att pdu 0x%02x as size %u > att_server->request_buffer %u", packet[0], size, (int) sizeof(att_server->request_buffer)); 781 return; 782 } 783 784 #ifdef ENABLE_LE_SIGNED_WRITE 785 // abort signed write validation if a new request comes in (but finish previous signed write if possible) 786 if (att_server->state == ATT_SERVER_W4_SIGNED_WRITE_VALIDATION){ 787 if (packet[0] == ATT_SIGNED_WRITE_COMMAND){ 788 log_info("skip new signed write request as previous is in validation"); 789 return; 790 } else { 791 log_info("abort signed write validation to process new request"); 792 att_server->state = ATT_SERVER_IDLE; 793 } 794 } 795 #endif 796 // last request still in processing? 797 if (att_server->state != ATT_SERVER_IDLE){ 798 log_info("skip att pdu 0x%02x as server not idle (state %u)", packet[0], att_server->state); 799 return; 800 } 801 802 // store request 803 att_server->state = ATT_SERVER_REQUEST_RECEIVED; 804 att_server->request_size = size; 805 memcpy(att_server->request_buffer, packet, size); 806 807 att_run_for_context(att_server); 808 } 809 810 static void att_packet_handler(uint8_t packet_type, uint16_t handle, uint8_t *packet, uint16_t size){ 811 att_server_t * att_server; 812 813 switch (packet_type){ 814 case HCI_EVENT_PACKET: 815 switch (packet[0]){ 816 case L2CAP_EVENT_CAN_SEND_NOW: 817 att_server_handle_can_send_now(); 818 break; 819 case ATT_EVENT_MTU_EXCHANGE_COMPLETE: 820 // GATT client has negotiated the mtu for this connection 821 att_server = att_server_for_handle(handle); 822 if (!att_server) break; 823 att_server->connection.mtu = little_endian_read_16(packet, 4); 824 break; 825 default: 826 break; 827 } 828 break; 829 830 case ATT_DATA_PACKET: 831 log_debug("ATT Packet, handle 0x%04x", handle); 832 att_server = att_server_for_handle(handle); 833 if (!att_server) break; 834 835 att_server_handle_att_pdu(att_server, packet, size); 836 break; 837 } 838 } 839 840 // --------------------- 841 // persistent CCC writes 842 static uint32_t att_server_persistent_ccc_tag_for_index(uint8_t index){ 843 return ('B' << 24) | ('T' << 16) | ('C' << 8) | index; 844 } 845 846 static void att_server_persistent_ccc_write(hci_con_handle_t con_handle, uint16_t att_handle, uint16_t value){ 847 // lookup att_server instance 848 att_server_t * att_server = att_server_for_handle(con_handle); 849 if (!att_server) return; 850 int le_device_index = att_server->ir_le_device_db_index; 851 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); 852 853 // check if bonded 854 if (le_device_index < 0) return; 855 856 // get btstack_tlv 857 const btstack_tlv_t * tlv_impl = NULL; 858 void * tlv_context; 859 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 860 if (!tlv_impl) return; 861 862 // update ccc tag 863 int index; 864 uint32_t highest_seq_nr = 0; 865 uint32_t lowest_seq_nr = 0; 866 uint32_t tag_for_lowest_seq_nr = 0; 867 uint32_t tag_for_empty = 0; 868 persistent_ccc_entry_t entry; 869 for (index=0;index<NVN_NUM_GATT_SERVER_CCC;index++){ 870 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 871 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 872 873 // empty/invalid tag 874 if (len != sizeof(persistent_ccc_entry_t)){ 875 tag_for_empty = tag; 876 continue; 877 } 878 // update highest seq nr 879 if (entry.seq_nr > highest_seq_nr){ 880 highest_seq_nr = entry.seq_nr; 881 } 882 // find entry with lowest seq nr 883 if ((tag_for_lowest_seq_nr == 0) || (entry.seq_nr < lowest_seq_nr)){ 884 tag_for_lowest_seq_nr = tag; 885 lowest_seq_nr = entry.seq_nr; 886 } 887 888 if (entry.device_index != le_device_index) continue; 889 if (entry.att_handle != att_handle) continue; 890 891 // found matching entry 892 if (value){ 893 // update 894 if (entry.value == value) { 895 log_info("CCC Index %u: Up-to-date", index); 896 return; 897 } 898 entry.value = value; 899 entry.seq_nr = highest_seq_nr + 1; 900 log_info("CCC Index %u: Store", index); 901 tlv_impl->store_tag(tlv_context, tag, (const uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 902 } else { 903 // delete 904 log_info("CCC Index %u: Delete", index); 905 tlv_impl->delete_tag(tlv_context, tag); 906 } 907 return; 908 } 909 910 log_info("tag_for_empy %"PRIx32", tag_for_lowest_seq_nr %"PRIx32, tag_for_empty, tag_for_lowest_seq_nr); 911 912 if (value == 0){ 913 // done 914 return; 915 } 916 917 uint32_t tag_to_use = 0; 918 if (tag_for_empty){ 919 tag_to_use = tag_for_empty; 920 } else if (tag_for_lowest_seq_nr){ 921 tag_to_use = tag_for_lowest_seq_nr; 922 } else { 923 // should not happen 924 return; 925 } 926 // store ccc tag 927 entry.seq_nr = highest_seq_nr + 1; 928 entry.device_index = le_device_index; 929 entry.att_handle = att_handle; 930 entry.value = value; 931 tlv_impl->store_tag(tlv_context, tag_to_use, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 932 } 933 934 static void att_server_persistent_ccc_clear(att_server_t * att_server){ 935 if (!att_server) return; 936 int le_device_index = att_server->ir_le_device_db_index; 937 log_info("Clear CCC values of remote %s, le device id %d", bd_addr_to_str(att_server->peer_address), le_device_index); 938 // check if bonded 939 if (le_device_index < 0) return; 940 // get btstack_tlv 941 const btstack_tlv_t * tlv_impl = NULL; 942 void * tlv_context; 943 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 944 if (!tlv_impl) return; 945 // get all ccc tag 946 int index; 947 persistent_ccc_entry_t entry; 948 for (index=0;index<NVN_NUM_GATT_SERVER_CCC;index++){ 949 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 950 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 951 if (len != sizeof(persistent_ccc_entry_t)) continue; 952 if (entry.device_index != le_device_index) continue; 953 // delete entry 954 log_info("CCC Index %u: Delete", index); 955 tlv_impl->delete_tag(tlv_context, tag); 956 } 957 } 958 959 static void att_server_persistent_ccc_restore(att_server_t * att_server){ 960 if (!att_server) return; 961 int le_device_index = att_server->ir_le_device_db_index; 962 log_info("Restore CCC values of remote %s, le device id %d", bd_addr_to_str(att_server->peer_address), le_device_index); 963 // check if bonded 964 if (le_device_index < 0) return; 965 // get btstack_tlv 966 const btstack_tlv_t * tlv_impl = NULL; 967 void * tlv_context; 968 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 969 if (!tlv_impl) return; 970 // get all ccc tag 971 int index; 972 persistent_ccc_entry_t entry; 973 for (index=0;index<NVN_NUM_GATT_SERVER_CCC;index++){ 974 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 975 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 976 if (len != sizeof(persistent_ccc_entry_t)) continue; 977 if (entry.device_index != le_device_index) continue; 978 // simulate write callback 979 uint16_t attribute_handle = entry.att_handle; 980 uint8_t value[2]; 981 little_endian_store_16(value, 0, entry.value); 982 att_write_callback_t callback = att_server_write_callback_for_handle(attribute_handle); 983 if (!callback) continue; 984 log_info("CCC Index %u: Set Attribute handle 0x%04x to value 0x%04x", index, attribute_handle, entry.value ); 985 (*callback)(att_server->connection.con_handle, attribute_handle, ATT_TRANSACTION_MODE_NONE, 0, value, sizeof(value)); 986 } 987 } 988 989 // persistent CCC writes 990 // --------------------- 991 992 // gatt service management 993 static att_service_handler_t * att_service_handler_for_handle(uint16_t handle){ 994 btstack_linked_list_iterator_t it; 995 btstack_linked_list_iterator_init(&it, &service_handlers); 996 while (btstack_linked_list_iterator_has_next(&it)){ 997 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 998 if (handler->start_handle > handle) continue; 999 if (handler->end_handle < handle) continue; 1000 return handler; 1001 } 1002 return NULL; 1003 } 1004 static att_read_callback_t att_server_read_callback_for_handle(uint16_t handle){ 1005 att_service_handler_t * handler = att_service_handler_for_handle(handle); 1006 if (handler) return handler->read_callback; 1007 return att_server_client_read_callback; 1008 } 1009 1010 static att_write_callback_t att_server_write_callback_for_handle(uint16_t handle){ 1011 att_service_handler_t * handler = att_service_handler_for_handle(handle); 1012 if (handler) return handler->write_callback; 1013 return att_server_client_write_callback; 1014 } 1015 1016 static btstack_packet_handler_t att_server_packet_handler_for_handle(uint16_t handle){ 1017 att_service_handler_t * handler = att_service_handler_for_handle(handle); 1018 if (handler) return handler->packet_handler; 1019 return att_client_packet_handler; 1020 } 1021 1022 static void att_notify_write_callbacks(hci_con_handle_t con_handle, uint16_t transaction_mode){ 1023 // notify all callbacks 1024 btstack_linked_list_iterator_t it; 1025 btstack_linked_list_iterator_init(&it, &service_handlers); 1026 while (btstack_linked_list_iterator_has_next(&it)){ 1027 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 1028 if (!handler->write_callback) continue; 1029 (*handler->write_callback)(con_handle, 0, transaction_mode, 0, NULL, 0); 1030 } 1031 if (!att_server_client_write_callback) return; 1032 (*att_server_client_write_callback)(con_handle, 0, transaction_mode, 0, NULL, 0); 1033 } 1034 1035 // returns first reported error or 0 1036 static uint8_t att_validate_prepared_write(hci_con_handle_t con_handle){ 1037 btstack_linked_list_iterator_t it; 1038 btstack_linked_list_iterator_init(&it, &service_handlers); 1039 while (btstack_linked_list_iterator_has_next(&it)){ 1040 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 1041 if (!handler->write_callback) continue; 1042 uint8_t error_code = (*handler->write_callback)(con_handle, 0, ATT_TRANSACTION_MODE_VALIDATE, 0, NULL, 0); 1043 if (error_code) return error_code; 1044 } 1045 if (!att_server_client_write_callback) return 0; 1046 return (*att_server_client_write_callback)(con_handle, 0, ATT_TRANSACTION_MODE_VALIDATE, 0, NULL, 0); 1047 } 1048 1049 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){ 1050 att_read_callback_t callback = att_server_read_callback_for_handle(attribute_handle); 1051 if (!callback) return 0; 1052 return (*callback)(con_handle, attribute_handle, offset, buffer, buffer_size); 1053 } 1054 1055 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){ 1056 switch (transaction_mode){ 1057 case ATT_TRANSACTION_MODE_VALIDATE: 1058 return att_validate_prepared_write(con_handle); 1059 case ATT_TRANSACTION_MODE_EXECUTE: 1060 case ATT_TRANSACTION_MODE_CANCEL: 1061 att_notify_write_callbacks(con_handle, transaction_mode); 1062 return 0; 1063 default: 1064 break; 1065 } 1066 1067 // track CCC writes 1068 if (att_is_persistent_ccc(attribute_handle) && (offset == 0) && (buffer_size == 2)){ 1069 att_server_persistent_ccc_write(con_handle, attribute_handle, little_endian_read_16(buffer, 0)); 1070 } 1071 1072 att_write_callback_t callback = att_server_write_callback_for_handle(attribute_handle); 1073 if (!callback) return 0; 1074 return (*callback)(con_handle, attribute_handle, transaction_mode, offset, buffer, buffer_size); 1075 } 1076 1077 /** 1078 * @brief register read/write callbacks for specific handle range 1079 * @param att_service_handler_t 1080 */ 1081 void att_server_register_service_handler(att_service_handler_t * handler){ 1082 if (att_service_handler_for_handle(handler->start_handle) || 1083 att_service_handler_for_handle(handler->end_handle)){ 1084 log_error("handler for range 0x%04x-0x%04x already registered", handler->start_handle, handler->end_handle); 1085 return; 1086 } 1087 btstack_linked_list_add(&service_handlers, (btstack_linked_item_t*) handler); 1088 } 1089 1090 void att_server_init(uint8_t const * db, att_read_callback_t read_callback, att_write_callback_t write_callback){ 1091 1092 // store callbacks 1093 att_server_client_read_callback = read_callback; 1094 att_server_client_write_callback = write_callback; 1095 1096 // register for HCI Events 1097 hci_event_callback_registration.callback = &att_event_packet_handler; 1098 hci_add_event_handler(&hci_event_callback_registration); 1099 1100 // register for SM events 1101 sm_event_callback_registration.callback = &att_event_packet_handler; 1102 sm_add_event_handler(&sm_event_callback_registration); 1103 1104 // and L2CAP ATT Server PDUs 1105 att_dispatch_register_server(att_packet_handler); 1106 1107 #ifdef ENABLE_GATT_OVER_CLASSIC 1108 // setup l2cap service 1109 l2cap_register_service(&att_event_packet_handler, PSM_ATT, 0xffff, LEVEL_2); 1110 #endif 1111 1112 att_set_db(db); 1113 att_set_read_callback(att_server_read_callback); 1114 att_set_write_callback(att_server_write_callback); 1115 } 1116 1117 void att_server_register_packet_handler(btstack_packet_handler_t handler){ 1118 att_client_packet_handler = handler; 1119 } 1120 1121 1122 // to be deprecated 1123 int att_server_can_send_packet_now(hci_con_handle_t con_handle){ 1124 att_server_t * att_server = att_server_for_handle(con_handle); 1125 if (!att_server) return 0; 1126 return att_server_can_send_packet(att_server); 1127 } 1128 1129 int att_server_register_can_send_now_callback(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 1130 return att_server_request_to_send_notification(callback_registration, con_handle); 1131 } 1132 1133 void att_server_request_can_send_now_event(hci_con_handle_t con_handle){ 1134 att_client_waiting_for_can_send_registration.callback = &att_emit_can_send_now_event; 1135 att_server_request_to_send_notification(&att_client_waiting_for_can_send_registration, con_handle); 1136 } 1137 // end of deprecated 1138 1139 int att_server_request_to_send_notification(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 1140 att_server_t * att_server = att_server_for_handle(con_handle); 1141 if (!att_server) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1142 btstack_linked_list_add_tail(&att_server->notification_requests, (btstack_linked_item_t*) callback_registration); 1143 att_server_request_can_send_now(att_server); 1144 return ERROR_CODE_SUCCESS; 1145 } 1146 1147 int att_server_request_to_send_indication(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 1148 att_server_t * att_server = att_server_for_handle(con_handle); 1149 if (!att_server) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1150 btstack_linked_list_add_tail(&att_server->indication_requests, (btstack_linked_item_t*) callback_registration); 1151 att_server_request_can_send_now(att_server); 1152 return ERROR_CODE_SUCCESS; 1153 } 1154 1155 int att_server_notify(hci_con_handle_t con_handle, uint16_t attribute_handle, const uint8_t *value, uint16_t value_len){ 1156 att_server_t * att_server = att_server_for_handle(con_handle); 1157 if (!att_server) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1158 if (!att_server_can_send_packet(att_server)) return BTSTACK_ACL_BUFFERS_FULL; 1159 1160 l2cap_reserve_packet_buffer(); 1161 uint8_t * packet_buffer = l2cap_get_outgoing_buffer(); 1162 uint16_t size = att_prepare_handle_value_notification(&att_server->connection, attribute_handle, value, value_len, packet_buffer); 1163 return l2cap_send_prepared_connectionless(att_server->connection.con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, size); 1164 } 1165 1166 int att_server_indicate(hci_con_handle_t con_handle, uint16_t attribute_handle, const uint8_t *value, uint16_t value_len){ 1167 att_server_t * att_server = att_server_for_handle(con_handle); 1168 if (!att_server) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1169 1170 if (att_server->value_indication_handle) return ATT_HANDLE_VALUE_INDICATION_IN_PROGRESS; 1171 if (!att_server_can_send_packet(att_server)) return BTSTACK_ACL_BUFFERS_FULL; 1172 1173 // track indication 1174 att_server->value_indication_handle = attribute_handle; 1175 btstack_run_loop_set_timer_handler(&att_server->value_indication_timer, att_handle_value_indication_timeout); 1176 btstack_run_loop_set_timer(&att_server->value_indication_timer, ATT_TRANSACTION_TIMEOUT_MS); 1177 btstack_run_loop_add_timer(&att_server->value_indication_timer); 1178 1179 l2cap_reserve_packet_buffer(); 1180 uint8_t * packet_buffer = l2cap_get_outgoing_buffer(); 1181 uint16_t size = att_prepare_handle_value_indication(&att_server->connection, attribute_handle, value, value_len, packet_buffer); 1182 l2cap_send_prepared_connectionless(att_server->connection.con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, size); 1183 return 0; 1184 } 1185 1186 uint16_t att_server_get_mtu(hci_con_handle_t con_handle){ 1187 att_server_t * att_server = att_server_for_handle(con_handle); 1188 if (!att_server) return 0; 1189 return att_server->connection.mtu; 1190 } 1191