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(hci_connection_t * hci_connection); 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(hci_connection_t * hci_connection); 79 static void att_server_persistent_ccc_clear(hci_connection_t * hci_connection); 80 static void att_server_handle_att_pdu(hci_connection_t * hci_connection, 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 #ifdef ENABLE_LE_SIGNED_WRITE 110 static hci_connection_t * hci_connection_for_state(att_server_state_t state){ 111 btstack_linked_list_iterator_t it; 112 hci_connections_get_iterator(&it); 113 while(btstack_linked_list_iterator_has_next(&it)){ 114 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 115 att_server_t * att_server = &connection->att_server; 116 if (att_server->state == state) return connection; 117 } 118 return NULL; 119 } 120 #endif 121 122 static void att_server_request_can_send_now(hci_connection_t * hci_connection){ 123 att_server_t * att_server = &hci_connection->att_server; 124 #ifdef ENABLE_GATT_OVER_CLASSIC 125 if (att_server->l2cap_cid != 0){ 126 l2cap_request_can_send_now_event(att_server->l2cap_cid); 127 return; 128 } 129 #endif 130 att_dispatch_server_request_can_send_now_event(att_server->connection.con_handle); 131 } 132 133 static int att_server_can_send_packet(hci_connection_t * hci_connection){ 134 att_server_t * att_server = &hci_connection->att_server; 135 #ifdef ENABLE_GATT_OVER_CLASSIC 136 if (att_server->l2cap_cid != 0){ 137 return l2cap_can_send_packet_now(att_server->l2cap_cid); 138 } 139 #endif 140 return att_dispatch_server_can_send_now(att_server->connection.con_handle); 141 } 142 143 static void att_handle_value_indication_notify_client(uint8_t status, uint16_t client_handle, uint16_t attribute_handle){ 144 btstack_packet_handler_t packet_handler = att_server_packet_handler_for_handle(attribute_handle); 145 if (!packet_handler) return; 146 147 uint8_t event[7]; 148 int pos = 0; 149 event[pos++] = ATT_EVENT_HANDLE_VALUE_INDICATION_COMPLETE; 150 event[pos++] = sizeof(event) - 2u; 151 event[pos++] = status; 152 little_endian_store_16(event, pos, client_handle); 153 pos += 2; 154 little_endian_store_16(event, pos, attribute_handle); 155 (*packet_handler)(HCI_EVENT_PACKET, 0, &event[0], sizeof(event)); 156 } 157 158 static void att_emit_event_to_all(const uint8_t * event, uint16_t size){ 159 // dispatch to app level handler 160 if (att_client_packet_handler){ 161 (*att_client_packet_handler)(HCI_EVENT_PACKET, 0, (uint8_t*) event, size); 162 } 163 164 // dispatch to service handlers 165 btstack_linked_list_iterator_t it; 166 btstack_linked_list_iterator_init(&it, &service_handlers); 167 while (btstack_linked_list_iterator_has_next(&it)){ 168 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 169 if (!handler->packet_handler) continue; 170 (*handler->packet_handler)(HCI_EVENT_PACKET, 0, (uint8_t*) event, size); 171 } 172 } 173 174 static void att_emit_mtu_event(hci_con_handle_t con_handle, uint16_t mtu){ 175 uint8_t event[6]; 176 int pos = 0; 177 event[pos++] = ATT_EVENT_MTU_EXCHANGE_COMPLETE; 178 event[pos++] = sizeof(event) - 2u; 179 little_endian_store_16(event, pos, con_handle); 180 pos += 2; 181 little_endian_store_16(event, pos, mtu); 182 183 // also dispatch to GATT Clients 184 att_dispatch_server_mtu_exchanged(con_handle, mtu); 185 186 // dispatch to app level handler and service handlers 187 att_emit_event_to_all(&event[0], sizeof(event)); 188 } 189 190 static void att_emit_can_send_now_event(void * context){ 191 UNUSED(context); 192 if (!att_client_packet_handler) return; 193 194 uint8_t event[] = { ATT_EVENT_CAN_SEND_NOW, 0}; 195 (*att_client_packet_handler)(HCI_EVENT_PACKET, 0, &event[0], sizeof(event)); 196 } 197 198 static void att_emit_connected_event(hci_connection_t * hci_connection){ 199 att_server_t * att_server = &hci_connection->att_server; 200 uint8_t event[11]; 201 int pos = 0; 202 event[pos++] = ATT_EVENT_CONNECTED; 203 event[pos++] = sizeof(event) - 2u; 204 event[pos++] = att_server->peer_addr_type; 205 reverse_bd_addr(att_server->peer_address, &event[pos]); 206 pos += 6; 207 little_endian_store_16(event, pos, att_server->connection.con_handle); 208 pos += 2; 209 210 // dispatch to app level handler and service handlers 211 att_emit_event_to_all(&event[0], sizeof(event)); 212 } 213 214 215 static void att_emit_disconnected_event(uint16_t con_handle){ 216 uint8_t event[4]; 217 int pos = 0; 218 event[pos++] = ATT_EVENT_DISCONNECTED; 219 event[pos++] = sizeof(event) - 2u; 220 little_endian_store_16(event, pos, con_handle); 221 pos += 2; 222 223 // dispatch to app level handler and service handlers 224 att_emit_event_to_all(&event[0], sizeof(event)); 225 } 226 227 static void att_handle_value_indication_timeout(btstack_timer_source_t *ts){ 228 void * context = btstack_run_loop_get_timer_context(ts); 229 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) context; 230 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 231 if (!hci_connection) return; 232 att_server_t * att_server = &hci_connection->att_server; 233 // @note: after a transaction timeout, no more requests shall be sent over this ATT Bearer 234 // (that's why we don't reset the value_indication_handle) 235 uint16_t att_handle = att_server->value_indication_handle; 236 att_handle_value_indication_notify_client(ATT_HANDLE_VALUE_INDICATION_TIMEOUT, att_server->connection.con_handle, att_handle); 237 } 238 239 static void att_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 240 241 UNUSED(channel); // ok: there is no channel 242 UNUSED(size); // ok: handling own l2cap events 243 244 att_server_t * att_server; 245 hci_con_handle_t con_handle; 246 hci_connection_t * hci_connection; 247 #ifdef ENABLE_GATT_OVER_CLASSIC 248 bd_addr_t address; 249 btstack_linked_list_iterator_t it; 250 #endif 251 252 switch (packet_type) { 253 254 case HCI_EVENT_PACKET: 255 switch (hci_event_packet_get_type(packet)) { 256 257 #ifdef ENABLE_GATT_OVER_CLASSIC 258 case L2CAP_EVENT_INCOMING_CONNECTION: 259 l2cap_event_incoming_connection_get_address(packet, address); 260 l2cap_accept_connection(channel); 261 log_info("Accept incoming connection from %s", bd_addr_to_str(address)); 262 break; 263 case L2CAP_EVENT_CHANNEL_OPENED: 264 con_handle = l2cap_event_channel_opened_get_handle(packet); 265 hci_connection = hci_connection_for_handle(con_handle); 266 if (!hci_connection) break; 267 att_server = &hci_connection->att_server; 268 // store connection info 269 att_server->peer_addr_type = BD_ADDR_TYPE_ACL; 270 l2cap_event_channel_opened_get_address(packet, att_server->peer_address); 271 att_server->connection.con_handle = con_handle; 272 att_server->l2cap_cid = l2cap_event_channel_opened_get_local_cid(packet); 273 // reset connection properties 274 att_server->state = ATT_SERVER_IDLE; 275 att_server->connection.mtu = l2cap_event_channel_opened_get_remote_mtu(packet); 276 att_server->connection.max_mtu = l2cap_max_mtu(); 277 if (att_server->connection.max_mtu > ATT_REQUEST_BUFFER_SIZE){ 278 att_server->connection.max_mtu = ATT_REQUEST_BUFFER_SIZE; 279 } 280 281 log_info("Connection opened %s, l2cap cid %04x, mtu %u", bd_addr_to_str(address), att_server->l2cap_cid, att_server->connection.mtu); 282 283 // update security params 284 att_server->connection.encryption_key_size = gap_encryption_key_size(con_handle); 285 att_server->connection.authenticated = gap_authenticated(con_handle); 286 att_server->connection.secure_connection = gap_secure_connection(con_handle); 287 log_info("encrypted key size %u, authenticated %u, secure connection %u", 288 att_server->connection.encryption_key_size, att_server->connection.authenticated, att_server->connection.secure_connection); 289 290 // notify connection opened 291 att_emit_connected_event(hci_connection); 292 293 // restore persisten ccc if encrypted 294 if ( gap_security_level(con_handle) >= LEVEL_2){ 295 att_server_persistent_ccc_restore(hci_connection); 296 } 297 // TODO: what to do about le device db? 298 att_server->pairing_active = 0; 299 break; 300 case L2CAP_EVENT_CAN_SEND_NOW: 301 att_server_handle_can_send_now(); 302 break; 303 304 #endif 305 case HCI_EVENT_LE_META: 306 switch (packet[2]) { 307 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 308 con_handle = little_endian_read_16(packet, 4); 309 hci_connection = hci_connection_for_handle(con_handle); 310 if (!hci_connection) break; 311 att_server = &hci_connection->att_server; 312 // store connection info 313 att_server->peer_addr_type = packet[7]; 314 reverse_bd_addr(&packet[8], att_server->peer_address); 315 att_server->connection.con_handle = con_handle; 316 // reset connection properties 317 att_server->state = ATT_SERVER_IDLE; 318 att_server->connection.mtu = ATT_DEFAULT_MTU; 319 att_server->connection.max_mtu = l2cap_max_le_mtu(); 320 if (att_server->connection.max_mtu > ATT_REQUEST_BUFFER_SIZE){ 321 att_server->connection.max_mtu = ATT_REQUEST_BUFFER_SIZE; 322 } 323 att_server->connection.encryption_key_size = 0; 324 att_server->connection.authenticated = 0; 325 att_server->connection.authorized = 0; 326 // workaround: identity resolving can already be complete, at least store result 327 att_server->ir_le_device_db_index = sm_le_device_index(con_handle); 328 att_server->ir_lookup_active = 0; 329 att_server->pairing_active = 0; 330 // notify all - old 331 att_emit_event_to_all(packet, size); 332 // notify all - new 333 att_emit_connected_event(hci_connection); 334 break; 335 336 default: 337 break; 338 } 339 break; 340 341 case HCI_EVENT_ENCRYPTION_CHANGE: 342 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 343 // check handle 344 con_handle = little_endian_read_16(packet, 3); 345 hci_connection = hci_connection_for_handle(con_handle); 346 if (!hci_connection) break; 347 if (gap_get_connection_type(con_handle) != GAP_CONNECTION_LE) break; 348 // update security params 349 att_server = &hci_connection->att_server; 350 att_server->connection.encryption_key_size = gap_encryption_key_size(con_handle); 351 att_server->connection.authenticated = gap_authenticated(con_handle); 352 att_server->connection.secure_connection = gap_secure_connection(con_handle); 353 log_info("encrypted key size %u, authenticated %u, secure connection %u", 354 att_server->connection.encryption_key_size, att_server->connection.authenticated, att_server->connection.secure_connection); 355 if (hci_event_packet_get_type(packet) == HCI_EVENT_ENCRYPTION_CHANGE){ 356 // restore CCC values when encrypted for LE Connections 357 if (hci_event_encryption_change_get_encryption_enabled(packet)){ 358 att_server_persistent_ccc_restore(hci_connection); 359 } 360 } 361 att_run_for_context(hci_connection); 362 break; 363 364 case HCI_EVENT_DISCONNECTION_COMPLETE: 365 // check handle 366 con_handle = hci_event_disconnection_complete_get_connection_handle(packet); 367 hci_connection = hci_connection_for_handle(con_handle); 368 if (!hci_connection) break; 369 att_server = &hci_connection->att_server; 370 att_clear_transaction_queue(&att_server->connection); 371 att_server->connection.con_handle = 0; 372 att_server->pairing_active = 0; 373 att_server->state = ATT_SERVER_IDLE; 374 if (att_server->value_indication_handle){ 375 btstack_run_loop_remove_timer(&att_server->value_indication_timer); 376 uint16_t att_handle = att_server->value_indication_handle; 377 att_server->value_indication_handle = 0; // reset error state 378 att_handle_value_indication_notify_client(ATT_HANDLE_VALUE_INDICATION_DISCONNECT, att_server->connection.con_handle, att_handle); 379 } 380 // notify all - new 381 att_emit_disconnected_event(con_handle); 382 // notify all - old 383 att_emit_event_to_all(packet, size); 384 break; 385 386 // Identity Resolving 387 case SM_EVENT_IDENTITY_RESOLVING_STARTED: 388 con_handle = sm_event_identity_resolving_started_get_handle(packet); 389 hci_connection = hci_connection_for_handle(con_handle); 390 if (!hci_connection) break; 391 att_server = &hci_connection->att_server; 392 log_info("SM_EVENT_IDENTITY_RESOLVING_STARTED"); 393 att_server->ir_lookup_active = 1; 394 break; 395 case SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED: 396 con_handle = sm_event_identity_created_get_handle(packet); 397 hci_connection = hci_connection_for_handle(con_handle); 398 if (!hci_connection) return; 399 att_server = &hci_connection->att_server; 400 att_server->ir_lookup_active = 0; 401 att_server->ir_le_device_db_index = sm_event_identity_resolving_succeeded_get_index(packet); 402 log_info("SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED"); 403 att_run_for_context(hci_connection); 404 break; 405 case SM_EVENT_IDENTITY_RESOLVING_FAILED: 406 con_handle = sm_event_identity_resolving_failed_get_handle(packet); 407 hci_connection = hci_connection_for_handle(con_handle); 408 if (!hci_connection) break; 409 att_server = &hci_connection->att_server; 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(hci_connection); 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 hci_connection = hci_connection_for_handle(con_handle); 425 if (!hci_connection) break; 426 att_server = &hci_connection->att_server; 427 att_server->pairing_active = 1; 428 log_info("SM Pairing started"); 429 if (att_server->ir_le_device_db_index < 0) break; 430 att_server_persistent_ccc_clear(hci_connection); 431 // index not valid anymore 432 att_server->ir_le_device_db_index = -1; 433 break; 434 435 // Bonding completed 436 case SM_EVENT_IDENTITY_CREATED: 437 con_handle = sm_event_identity_created_get_handle(packet); 438 hci_connection = hci_connection_for_handle(con_handle); 439 if (!hci_connection) return; 440 att_server = &hci_connection->att_server; 441 att_server->pairing_active = 0; 442 att_server->ir_le_device_db_index = sm_event_identity_created_get_index(packet); 443 att_run_for_context(hci_connection); 444 break; 445 446 // Pairing complete (with/without bonding=storing of pairing information) 447 case SM_EVENT_PAIRING_COMPLETE: 448 con_handle = sm_event_pairing_complete_get_handle(packet); 449 hci_connection = hci_connection_for_handle(con_handle); 450 if (!hci_connection) return; 451 att_server = &hci_connection->att_server; 452 att_server->pairing_active = 0; 453 att_run_for_context(hci_connection); 454 break; 455 456 // Authorization 457 case SM_EVENT_AUTHORIZATION_RESULT: { 458 con_handle = sm_event_authorization_result_get_handle(packet); 459 hci_connection = hci_connection_for_handle(con_handle); 460 if (!hci_connection) break; 461 att_server = &hci_connection->att_server; 462 att_server->connection.authorized = sm_event_authorization_result_get_authorization_result(packet); 463 att_server_request_can_send_now(hci_connection); 464 break; 465 } 466 default: 467 break; 468 } 469 break; 470 #ifdef ENABLE_GATT_OVER_CLASSIC 471 case L2CAP_DATA_PACKET: 472 hci_connections_get_iterator(&it); 473 while(btstack_linked_list_iterator_has_next(&it)){ 474 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 475 att_server = &connection->att_server; 476 if (att_server->l2cap_cid == channel) { 477 att_server_handle_att_pdu(connection, packet, size); 478 break; 479 } 480 } 481 break; 482 #endif 483 484 default: 485 break; 486 } 487 } 488 489 #ifdef ENABLE_LE_SIGNED_WRITE 490 static void att_signed_write_handle_cmac_result(uint8_t hash[8]){ 491 492 hci_connection_t * hci_connection = hci_connection_for_state(ATT_SERVER_W4_SIGNED_WRITE_VALIDATION); 493 if (!hci_connection) return; 494 att_server_t * att_server = &hci_connection->att_server; 495 496 uint8_t hash_flipped[8]; 497 reverse_64(hash, hash_flipped); 498 if (memcmp(hash_flipped, &att_server->request_buffer[att_server->request_size-8], 8)){ 499 log_info("ATT Signed Write, invalid signature"); 500 att_server->state = ATT_SERVER_IDLE; 501 return; 502 } 503 log_info("ATT Signed Write, valid signature"); 504 505 // update sequence number 506 uint32_t counter_packet = little_endian_read_32(att_server->request_buffer, att_server->request_size-12); 507 le_device_db_remote_counter_set(att_server->ir_le_device_db_index, counter_packet+1); 508 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 509 att_server_request_can_send_now(hci_connection); 510 } 511 #endif 512 513 // pre: att_server->state == ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED 514 // pre: can send now 515 // returns: 1 if packet was sent 516 static int att_server_process_validated_request(hci_connection_t * hci_connection){ 517 att_server_t * att_server = & hci_connection->att_server; 518 519 l2cap_reserve_packet_buffer(); 520 uint8_t * att_response_buffer = l2cap_get_outgoing_buffer(); 521 uint16_t att_response_size = att_handle_request(&att_server->connection, att_server->request_buffer, att_server->request_size, att_response_buffer); 522 523 #ifdef ENABLE_ATT_DELAYED_RESPONSE 524 if ((att_response_size == ATT_READ_RESPONSE_PENDING) || (att_response_size == ATT_INTERNAL_WRITE_RESPONSE_PENDING)){ 525 // update state 526 att_server->state = ATT_SERVER_RESPONSE_PENDING; 527 528 // callback with handle ATT_READ_RESPONSE_PENDING for reads 529 if (att_response_size == ATT_READ_RESPONSE_PENDING){ 530 att_server_client_read_callback(att_server->connection.con_handle, ATT_READ_RESPONSE_PENDING, 0, NULL, 0); 531 } 532 533 // free reserved buffer 534 l2cap_release_packet_buffer(); 535 return 0; 536 } 537 #endif 538 539 // intercept "insufficient authorization" for authenticated connections to allow for user authorization 540 if ((att_response_size >= 4u) 541 && (att_response_buffer[0] == ATT_ERROR_RESPONSE) 542 && (att_response_buffer[4] == ATT_ERROR_INSUFFICIENT_AUTHORIZATION) 543 && (att_server->connection.authenticated)){ 544 545 switch (gap_authorization_state(att_server->connection.con_handle)){ 546 case AUTHORIZATION_UNKNOWN: 547 l2cap_release_packet_buffer(); 548 sm_request_pairing(att_server->connection.con_handle); 549 return 0; 550 case AUTHORIZATION_PENDING: 551 l2cap_release_packet_buffer(); 552 return 0; 553 default: 554 break; 555 } 556 } 557 558 att_server->state = ATT_SERVER_IDLE; 559 if (att_response_size == 0u) { 560 l2cap_release_packet_buffer(); 561 return 0; 562 } 563 564 #ifdef ENABLE_GATT_OVER_CLASSIC 565 if (att_server->l2cap_cid != 0){ 566 l2cap_send_prepared(att_server->l2cap_cid, att_response_size); 567 } else 568 #endif 569 { 570 l2cap_send_prepared_connectionless(att_server->connection.con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, att_response_size); 571 } 572 573 // notify client about MTU exchange result 574 if (att_response_buffer[0] == ATT_EXCHANGE_MTU_RESPONSE){ 575 att_emit_mtu_event(att_server->connection.con_handle, att_server->connection.mtu); 576 } 577 return 1; 578 } 579 580 #ifdef ENABLE_ATT_DELAYED_RESPONSE 581 int att_server_response_ready(hci_con_handle_t con_handle){ 582 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 583 if (!hci_connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 584 att_server_t * att_server = &hci_connection->att_server; 585 586 if (att_server->state != ATT_SERVER_RESPONSE_PENDING) return ERROR_CODE_COMMAND_DISALLOWED; 587 588 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 589 att_server_request_can_send_now(hci_connection); 590 return ERROR_CODE_SUCCESS; 591 } 592 #endif 593 594 static void att_run_for_context(hci_connection_t * hci_connection){ 595 att_server_t * att_server = &hci_connection->att_server; 596 switch (att_server->state){ 597 case ATT_SERVER_REQUEST_RECEIVED: 598 599 #ifdef ENABLE_GATT_OVER_CLASSIC 600 if (att_server->l2cap_cid != 0){ 601 // ok 602 } else 603 #endif 604 { 605 // wait until re-encryption as central is complete 606 if (gap_reconnect_security_setup_active(att_server->connection.con_handle)) break; 607 } 608 609 // wait until pairing is complete 610 if (att_server->pairing_active) break; 611 612 #ifdef ENABLE_LE_SIGNED_WRITE 613 if (att_server->request_buffer[0] == ATT_SIGNED_WRITE_COMMAND){ 614 log_info("ATT Signed Write!"); 615 if (!sm_cmac_ready()) { 616 log_info("ATT Signed Write, sm_cmac engine not ready. Abort"); 617 att_server->state = ATT_SERVER_IDLE; 618 return; 619 } 620 if (att_server->request_size < (3 + 12)) { 621 log_info("ATT Signed Write, request to short. Abort."); 622 att_server->state = ATT_SERVER_IDLE; 623 return; 624 } 625 if (att_server->ir_lookup_active){ 626 return; 627 } 628 if (att_server->ir_le_device_db_index < 0){ 629 log_info("ATT Signed Write, CSRK not available"); 630 att_server->state = ATT_SERVER_IDLE; 631 return; 632 } 633 634 // check counter 635 uint32_t counter_packet = little_endian_read_32(att_server->request_buffer, att_server->request_size-12); 636 uint32_t counter_db = le_device_db_remote_counter_get(att_server->ir_le_device_db_index); 637 log_info("ATT Signed Write, DB counter %"PRIu32", packet counter %"PRIu32, counter_db, counter_packet); 638 if (counter_packet < counter_db){ 639 log_info("ATT Signed Write, db reports higher counter, abort"); 640 att_server->state = ATT_SERVER_IDLE; 641 return; 642 } 643 644 // signature is { sequence counter, secure hash } 645 sm_key_t csrk; 646 le_device_db_remote_csrk_get(att_server->ir_le_device_db_index, csrk); 647 att_server->state = ATT_SERVER_W4_SIGNED_WRITE_VALIDATION; 648 log_info("Orig Signature: "); 649 log_info_hexdump( &att_server->request_buffer[att_server->request_size-8], 8); 650 uint16_t attribute_handle = little_endian_read_16(att_server->request_buffer, 1); 651 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); 652 return; 653 } 654 #endif 655 // move on 656 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 657 att_server_request_can_send_now(hci_connection); 658 break; 659 660 default: 661 break; 662 } 663 } 664 665 static int att_server_data_ready_for_phase(att_server_t * att_server, att_server_run_phase_t phase){ 666 switch (phase){ 667 case ATT_SERVER_RUN_PHASE_1_REQUESTS: 668 return att_server->state == ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 669 case ATT_SERVER_RUN_PHASE_2_INDICATIONS: 670 return (!btstack_linked_list_empty(&att_server->indication_requests) && (att_server->value_indication_handle == 0)); 671 case ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS: 672 return (!btstack_linked_list_empty(&att_server->notification_requests)); 673 default: 674 btstack_assert(false); 675 return 0; 676 } 677 } 678 679 static void att_server_trigger_send_for_phase(hci_connection_t * hci_connection, att_server_run_phase_t phase){ 680 btstack_context_callback_registration_t * client; 681 att_server_t * att_server = &hci_connection->att_server; 682 switch (phase){ 683 case ATT_SERVER_RUN_PHASE_1_REQUESTS: 684 att_server_process_validated_request(hci_connection); 685 break; 686 case ATT_SERVER_RUN_PHASE_2_INDICATIONS: 687 client = (btstack_context_callback_registration_t*) att_server->indication_requests; 688 btstack_linked_list_remove(&att_server->indication_requests, (btstack_linked_item_t *) client); 689 client->callback(client->context); 690 break; 691 case ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS: 692 client = (btstack_context_callback_registration_t*) att_server->notification_requests; 693 btstack_linked_list_remove(&att_server->notification_requests, (btstack_linked_item_t *) client); 694 client->callback(client->context); 695 break; 696 default: 697 btstack_assert(false); 698 break; 699 } 700 } 701 702 static void att_server_handle_can_send_now(void){ 703 704 hci_con_handle_t last_send_con_handle = HCI_CON_HANDLE_INVALID; 705 hci_connection_t * request_hci_connection = NULL; 706 int can_send_now = 1; 707 int phase_index; 708 709 for (phase_index = ATT_SERVER_RUN_PHASE_1_REQUESTS; phase_index <= ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS; phase_index++){ 710 att_server_run_phase_t phase = (att_server_run_phase_t) phase_index; 711 hci_con_handle_t skip_connections_until = att_server_last_can_send_now; 712 while (true){ 713 btstack_linked_list_iterator_t it; 714 hci_connections_get_iterator(&it); 715 while(btstack_linked_list_iterator_has_next(&it)){ 716 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 717 att_server_t * att_server = &connection->att_server; 718 719 int data_ready = att_server_data_ready_for_phase(att_server, phase); 720 721 // 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); 722 723 // skip until last sender found (which is also skipped) 724 if (skip_connections_until != HCI_CON_HANDLE_INVALID){ 725 if (data_ready && (request_hci_connection == NULL)){ 726 request_hci_connection = connection; 727 } 728 if (skip_connections_until == att_server->connection.con_handle){ 729 skip_connections_until = HCI_CON_HANDLE_INVALID; 730 } 731 continue; 732 }; 733 734 if (data_ready){ 735 if (can_send_now){ 736 att_server_trigger_send_for_phase(connection, phase); 737 last_send_con_handle = att_server->connection.con_handle; 738 can_send_now = att_server_can_send_packet(connection); 739 data_ready = att_server_data_ready_for_phase(att_server, phase); 740 if (data_ready && (request_hci_connection == NULL)){ 741 request_hci_connection = connection; 742 } 743 } else { 744 request_hci_connection = connection; 745 break; 746 } 747 } 748 } 749 750 // stop skipping (handles disconnect by last send connection) 751 skip_connections_until = HCI_CON_HANDLE_INVALID; 752 753 // Exit loop, if we cannot send 754 if (!can_send_now) break; 755 756 // Exit loop, if we can send but there are also no further request 757 if (request_hci_connection == NULL) break; 758 759 // Finally, if we still can send and there are requests, just try again 760 request_hci_connection = NULL; 761 } 762 // update last send con handle for round robin 763 if (last_send_con_handle != HCI_CON_HANDLE_INVALID){ 764 att_server_last_can_send_now = last_send_con_handle; 765 } 766 } 767 768 if (request_hci_connection == NULL) return; 769 att_server_request_can_send_now(request_hci_connection); 770 } 771 772 static void att_server_handle_att_pdu(hci_connection_t * hci_connection, uint8_t * packet, uint16_t size){ 773 att_server_t * att_server = &hci_connection->att_server; 774 775 // handle value indication confirms 776 if ((packet[0] == ATT_HANDLE_VALUE_CONFIRMATION) && att_server->value_indication_handle){ 777 btstack_run_loop_remove_timer(&att_server->value_indication_timer); 778 uint16_t att_handle = att_server->value_indication_handle; 779 att_server->value_indication_handle = 0; 780 att_handle_value_indication_notify_client(0, att_server->connection.con_handle, att_handle); 781 att_server_request_can_send_now(hci_connection); 782 return; 783 } 784 785 // directly process command 786 // note: signed write cannot be handled directly as authentication needs to be verified 787 if (packet[0] == ATT_WRITE_COMMAND){ 788 att_handle_request(&att_server->connection, packet, size, NULL); 789 return; 790 } 791 792 // check size 793 if (size > sizeof(att_server->request_buffer)) { 794 log_info("drop att pdu 0x%02x as size %u > att_server->request_buffer %u", packet[0], size, (int) sizeof(att_server->request_buffer)); 795 return; 796 } 797 798 #ifdef ENABLE_LE_SIGNED_WRITE 799 // abort signed write validation if a new request comes in (but finish previous signed write if possible) 800 if (att_server->state == ATT_SERVER_W4_SIGNED_WRITE_VALIDATION){ 801 if (packet[0] == ATT_SIGNED_WRITE_COMMAND){ 802 log_info("skip new signed write request as previous is in validation"); 803 return; 804 } else { 805 log_info("abort signed write validation to process new request"); 806 att_server->state = ATT_SERVER_IDLE; 807 } 808 } 809 #endif 810 // last request still in processing? 811 if (att_server->state != ATT_SERVER_IDLE){ 812 log_info("skip att pdu 0x%02x as server not idle (state %u)", packet[0], att_server->state); 813 return; 814 } 815 816 // store request 817 att_server->state = ATT_SERVER_REQUEST_RECEIVED; 818 att_server->request_size = size; 819 (void)memcpy(att_server->request_buffer, packet, size); 820 821 att_run_for_context(hci_connection); 822 } 823 824 static void att_packet_handler(uint8_t packet_type, uint16_t handle, uint8_t *packet, uint16_t size){ 825 att_server_t * att_server; 826 hci_connection_t * hci_connection; 827 828 switch (packet_type){ 829 case HCI_EVENT_PACKET: 830 switch (packet[0]){ 831 case L2CAP_EVENT_CAN_SEND_NOW: 832 att_server_handle_can_send_now(); 833 break; 834 case ATT_EVENT_MTU_EXCHANGE_COMPLETE: 835 // GATT client has negotiated the mtu for this connection 836 hci_connection = hci_connection_for_handle(handle); 837 if (!hci_connection) break; 838 att_server = &hci_connection->att_server; 839 att_server->connection.mtu = little_endian_read_16(packet, 4); 840 break; 841 default: 842 break; 843 } 844 break; 845 846 case ATT_DATA_PACKET: 847 log_debug("ATT Packet, handle 0x%04x", handle); 848 hci_connection = hci_connection_for_handle(handle); 849 if (!hci_connection) break; 850 851 att_server_handle_att_pdu(hci_connection, packet, size); 852 break; 853 854 default: 855 break; 856 } 857 } 858 859 // --------------------- 860 // persistent CCC writes 861 static uint32_t att_server_persistent_ccc_tag_for_index(uint8_t index){ 862 return ('B' << 24u) | ('T' << 16u) | ('C' << 8u) | index; 863 } 864 865 static void att_server_persistent_ccc_write(hci_con_handle_t con_handle, uint16_t att_handle, uint16_t value){ 866 // lookup att_server instance 867 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 868 if (!hci_connection) return; 869 att_server_t * att_server = &hci_connection->att_server; 870 int le_device_index = att_server->ir_le_device_db_index; 871 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); 872 873 // check if bonded 874 if (le_device_index < 0) return; 875 876 // get btstack_tlv 877 const btstack_tlv_t * tlv_impl = NULL; 878 void * tlv_context; 879 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 880 if (!tlv_impl) return; 881 882 // update ccc tag 883 int index; 884 uint32_t highest_seq_nr = 0; 885 uint32_t lowest_seq_nr = 0; 886 uint32_t tag_for_lowest_seq_nr = 0; 887 uint32_t tag_for_empty = 0; 888 persistent_ccc_entry_t entry; 889 for (index=0;index<NVN_NUM_GATT_SERVER_CCC;index++){ 890 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 891 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 892 893 // empty/invalid tag 894 if (len != sizeof(persistent_ccc_entry_t)){ 895 tag_for_empty = tag; 896 continue; 897 } 898 // update highest seq nr 899 if (entry.seq_nr > highest_seq_nr){ 900 highest_seq_nr = entry.seq_nr; 901 } 902 // find entry with lowest seq nr 903 if ((tag_for_lowest_seq_nr == 0u) || (entry.seq_nr < lowest_seq_nr)){ 904 tag_for_lowest_seq_nr = tag; 905 lowest_seq_nr = entry.seq_nr; 906 } 907 908 if (entry.device_index != le_device_index) continue; 909 if (entry.att_handle != att_handle) continue; 910 911 // found matching entry 912 if (value){ 913 // update 914 if (entry.value == value) { 915 log_info("CCC Index %u: Up-to-date", index); 916 return; 917 } 918 entry.value = value; 919 entry.seq_nr = highest_seq_nr + 1u; 920 log_info("CCC Index %u: Store", index); 921 int result = tlv_impl->store_tag(tlv_context, tag, (const uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 922 if (result != 0){ 923 log_error("Store tag index %u failed", index); 924 } 925 } else { 926 // delete 927 log_info("CCC Index %u: Delete", index); 928 tlv_impl->delete_tag(tlv_context, tag); 929 } 930 return; 931 } 932 933 log_info("tag_for_empty %"PRIx32", tag_for_lowest_seq_nr %"PRIx32, tag_for_empty, tag_for_lowest_seq_nr); 934 935 if (value == 0u){ 936 // done 937 return; 938 } 939 940 uint32_t tag_to_use = 0; 941 if (tag_for_empty){ 942 tag_to_use = tag_for_empty; 943 } else if (tag_for_lowest_seq_nr){ 944 tag_to_use = tag_for_lowest_seq_nr; 945 } else { 946 // should not happen 947 return; 948 } 949 // store ccc tag 950 entry.seq_nr = highest_seq_nr + 1u; 951 entry.device_index = le_device_index; 952 entry.att_handle = att_handle; 953 entry.value = value; 954 int result = tlv_impl->store_tag(tlv_context, tag_to_use, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 955 if (result != 0){ 956 log_error("Store tag index %u failed", index); 957 } 958 } 959 960 static void att_server_persistent_ccc_clear(hci_connection_t * hci_connection){ 961 if (!hci_connection) return; 962 att_server_t * att_server = &hci_connection->att_server; 963 964 int le_device_index = att_server->ir_le_device_db_index; 965 log_info("Clear CCC values of remote %s, le device id %d", bd_addr_to_str(att_server->peer_address), le_device_index); 966 // check if bonded 967 if (le_device_index < 0) return; 968 // get btstack_tlv 969 const btstack_tlv_t * tlv_impl = NULL; 970 void * tlv_context; 971 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 972 if (!tlv_impl) return; 973 // get all ccc tag 974 int index; 975 persistent_ccc_entry_t entry; 976 for (index=0;index<NVN_NUM_GATT_SERVER_CCC;index++){ 977 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 978 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 979 if (len != sizeof(persistent_ccc_entry_t)) continue; 980 if (entry.device_index != le_device_index) continue; 981 // delete entry 982 log_info("CCC Index %u: Delete", index); 983 tlv_impl->delete_tag(tlv_context, tag); 984 } 985 } 986 987 static void att_server_persistent_ccc_restore(hci_connection_t * hci_connection){ 988 if (!hci_connection) return; 989 att_server_t * att_server = &hci_connection->att_server; 990 991 int le_device_index = att_server->ir_le_device_db_index; 992 log_info("Restore CCC values of remote %s, le device id %d", bd_addr_to_str(att_server->peer_address), le_device_index); 993 // check if bonded 994 if (le_device_index < 0) return; 995 // get btstack_tlv 996 const btstack_tlv_t * tlv_impl = NULL; 997 void * tlv_context; 998 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 999 if (!tlv_impl) return; 1000 // get all ccc tag 1001 int index; 1002 persistent_ccc_entry_t entry; 1003 for (index=0;index<NVN_NUM_GATT_SERVER_CCC;index++){ 1004 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 1005 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 1006 if (len != sizeof(persistent_ccc_entry_t)) continue; 1007 if (entry.device_index != le_device_index) continue; 1008 // simulate write callback 1009 uint16_t attribute_handle = entry.att_handle; 1010 uint8_t value[2]; 1011 little_endian_store_16(value, 0, entry.value); 1012 att_write_callback_t callback = att_server_write_callback_for_handle(attribute_handle); 1013 if (!callback) continue; 1014 log_info("CCC Index %u: Set Attribute handle 0x%04x to value 0x%04x", index, attribute_handle, entry.value ); 1015 (*callback)(att_server->connection.con_handle, attribute_handle, ATT_TRANSACTION_MODE_NONE, 0, value, sizeof(value)); 1016 } 1017 } 1018 1019 // persistent CCC writes 1020 // --------------------- 1021 1022 // gatt service management 1023 static att_service_handler_t * att_service_handler_for_handle(uint16_t handle){ 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->start_handle > handle) continue; 1029 if (handler->end_handle < handle) continue; 1030 return handler; 1031 } 1032 return NULL; 1033 } 1034 static att_read_callback_t att_server_read_callback_for_handle(uint16_t handle){ 1035 att_service_handler_t * handler = att_service_handler_for_handle(handle); 1036 if (handler) return handler->read_callback; 1037 return att_server_client_read_callback; 1038 } 1039 1040 static att_write_callback_t att_server_write_callback_for_handle(uint16_t handle){ 1041 att_service_handler_t * handler = att_service_handler_for_handle(handle); 1042 if (handler) return handler->write_callback; 1043 return att_server_client_write_callback; 1044 } 1045 1046 static btstack_packet_handler_t att_server_packet_handler_for_handle(uint16_t handle){ 1047 att_service_handler_t * handler = att_service_handler_for_handle(handle); 1048 if (handler) return handler->packet_handler; 1049 return att_client_packet_handler; 1050 } 1051 1052 static void att_notify_write_callbacks(hci_con_handle_t con_handle, uint16_t transaction_mode){ 1053 // notify all callbacks 1054 btstack_linked_list_iterator_t it; 1055 btstack_linked_list_iterator_init(&it, &service_handlers); 1056 while (btstack_linked_list_iterator_has_next(&it)){ 1057 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 1058 if (!handler->write_callback) continue; 1059 (*handler->write_callback)(con_handle, 0, transaction_mode, 0, NULL, 0); 1060 } 1061 if (!att_server_client_write_callback) return; 1062 (*att_server_client_write_callback)(con_handle, 0, transaction_mode, 0, NULL, 0); 1063 } 1064 1065 // returns first reported error or 0 1066 static uint8_t att_validate_prepared_write(hci_con_handle_t con_handle){ 1067 btstack_linked_list_iterator_t it; 1068 btstack_linked_list_iterator_init(&it, &service_handlers); 1069 while (btstack_linked_list_iterator_has_next(&it)){ 1070 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 1071 if (!handler->write_callback) continue; 1072 uint8_t error_code = (*handler->write_callback)(con_handle, 0, ATT_TRANSACTION_MODE_VALIDATE, 0, NULL, 0); 1073 if (error_code) return error_code; 1074 } 1075 if (!att_server_client_write_callback) return 0; 1076 return (*att_server_client_write_callback)(con_handle, 0, ATT_TRANSACTION_MODE_VALIDATE, 0, NULL, 0); 1077 } 1078 1079 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){ 1080 att_read_callback_t callback = att_server_read_callback_for_handle(attribute_handle); 1081 if (!callback) return 0; 1082 return (*callback)(con_handle, attribute_handle, offset, buffer, buffer_size); 1083 } 1084 1085 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){ 1086 switch (transaction_mode){ 1087 case ATT_TRANSACTION_MODE_VALIDATE: 1088 return att_validate_prepared_write(con_handle); 1089 case ATT_TRANSACTION_MODE_EXECUTE: 1090 case ATT_TRANSACTION_MODE_CANCEL: 1091 att_notify_write_callbacks(con_handle, transaction_mode); 1092 return 0; 1093 default: 1094 break; 1095 } 1096 1097 // track CCC writes 1098 if (att_is_persistent_ccc(attribute_handle) && (offset == 0u) && (buffer_size == 2u)){ 1099 att_server_persistent_ccc_write(con_handle, attribute_handle, little_endian_read_16(buffer, 0)); 1100 } 1101 1102 att_write_callback_t callback = att_server_write_callback_for_handle(attribute_handle); 1103 if (!callback) return 0; 1104 return (*callback)(con_handle, attribute_handle, transaction_mode, offset, buffer, buffer_size); 1105 } 1106 1107 /** 1108 * @brief register read/write callbacks for specific handle range 1109 * @param att_service_handler_t 1110 */ 1111 void att_server_register_service_handler(att_service_handler_t * handler){ 1112 if (att_service_handler_for_handle(handler->start_handle) || 1113 att_service_handler_for_handle(handler->end_handle)){ 1114 log_error("handler for range 0x%04x-0x%04x already registered", handler->start_handle, handler->end_handle); 1115 return; 1116 } 1117 btstack_linked_list_add(&service_handlers, (btstack_linked_item_t*) handler); 1118 } 1119 1120 void att_server_init(uint8_t const * db, att_read_callback_t read_callback, att_write_callback_t write_callback){ 1121 1122 // store callbacks 1123 att_server_client_read_callback = read_callback; 1124 att_server_client_write_callback = write_callback; 1125 1126 // register for HCI Events 1127 hci_event_callback_registration.callback = &att_event_packet_handler; 1128 hci_add_event_handler(&hci_event_callback_registration); 1129 1130 // register for SM events 1131 sm_event_callback_registration.callback = &att_event_packet_handler; 1132 sm_add_event_handler(&sm_event_callback_registration); 1133 1134 // and L2CAP ATT Server PDUs 1135 att_dispatch_register_server(att_packet_handler); 1136 1137 #ifdef ENABLE_GATT_OVER_CLASSIC 1138 // setup l2cap service 1139 l2cap_register_service(&att_event_packet_handler, PSM_ATT, 0xffff, LEVEL_2); 1140 #endif 1141 1142 att_set_db(db); 1143 att_set_read_callback(att_server_read_callback); 1144 att_set_write_callback(att_server_write_callback); 1145 } 1146 1147 void att_server_register_packet_handler(btstack_packet_handler_t handler){ 1148 att_client_packet_handler = handler; 1149 } 1150 1151 1152 // to be deprecated 1153 int att_server_can_send_packet_now(hci_con_handle_t con_handle){ 1154 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 1155 if (!hci_connection) return 0; 1156 return att_server_can_send_packet(hci_connection); 1157 } 1158 1159 int att_server_register_can_send_now_callback(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 1160 return att_server_request_to_send_notification(callback_registration, con_handle); 1161 } 1162 1163 void att_server_request_can_send_now_event(hci_con_handle_t con_handle){ 1164 att_client_waiting_for_can_send_registration.callback = &att_emit_can_send_now_event; 1165 att_server_request_to_send_notification(&att_client_waiting_for_can_send_registration, con_handle); 1166 } 1167 // end of deprecated 1168 1169 int att_server_request_to_send_notification(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 1170 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 1171 if (!hci_connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1172 att_server_t * att_server = &hci_connection->att_server; 1173 bool added = btstack_linked_list_add_tail(&att_server->notification_requests, (btstack_linked_item_t*) callback_registration); 1174 att_server_request_can_send_now(hci_connection); 1175 if (added){ 1176 return ERROR_CODE_SUCCESS; 1177 } else { 1178 return ERROR_CODE_COMMAND_DISALLOWED; 1179 } 1180 } 1181 1182 int att_server_request_to_send_indication(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 1183 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 1184 if (!hci_connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1185 att_server_t * att_server = &hci_connection->att_server; 1186 bool added = btstack_linked_list_add_tail(&att_server->indication_requests, (btstack_linked_item_t*) callback_registration); 1187 att_server_request_can_send_now(hci_connection); 1188 if (added){ 1189 return ERROR_CODE_SUCCESS; 1190 } else { 1191 return ERROR_CODE_COMMAND_DISALLOWED; 1192 } 1193 } 1194 1195 int att_server_notify(hci_con_handle_t con_handle, uint16_t attribute_handle, const uint8_t *value, uint16_t value_len){ 1196 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 1197 if (!hci_connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1198 att_server_t * att_server = &hci_connection->att_server; 1199 1200 if (!att_server_can_send_packet(hci_connection)) return BTSTACK_ACL_BUFFERS_FULL; 1201 1202 l2cap_reserve_packet_buffer(); 1203 uint8_t * packet_buffer = l2cap_get_outgoing_buffer(); 1204 uint16_t size = att_prepare_handle_value_notification(&att_server->connection, attribute_handle, value, value_len, packet_buffer); 1205 return l2cap_send_prepared_connectionless(att_server->connection.con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, size); 1206 } 1207 1208 int att_server_indicate(hci_con_handle_t con_handle, uint16_t attribute_handle, const uint8_t *value, uint16_t value_len){ 1209 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 1210 if (!hci_connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1211 att_server_t * att_server = &hci_connection->att_server; 1212 1213 if (att_server->value_indication_handle) return ATT_HANDLE_VALUE_INDICATION_IN_PROGRESS; 1214 if (!att_server_can_send_packet(hci_connection)) return BTSTACK_ACL_BUFFERS_FULL; 1215 1216 // track indication 1217 att_server->value_indication_handle = attribute_handle; 1218 btstack_run_loop_set_timer_handler(&att_server->value_indication_timer, att_handle_value_indication_timeout); 1219 btstack_run_loop_set_timer(&att_server->value_indication_timer, ATT_TRANSACTION_TIMEOUT_MS); 1220 btstack_run_loop_add_timer(&att_server->value_indication_timer); 1221 1222 l2cap_reserve_packet_buffer(); 1223 uint8_t * packet_buffer = l2cap_get_outgoing_buffer(); 1224 uint16_t size = att_prepare_handle_value_indication(&att_server->connection, attribute_handle, value, value_len, packet_buffer); 1225 l2cap_send_prepared_connectionless(att_server->connection.con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, size); 1226 return 0; 1227 } 1228 1229 uint16_t att_server_get_mtu(hci_con_handle_t con_handle){ 1230 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 1231 if (!hci_connection) return 0; 1232 att_server_t * att_server = &hci_connection->att_server; 1233 return att_server->connection.mtu; 1234 } 1235