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 BLUEKITCHEN 24 * GMBH 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 "ble/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 #ifdef ENABLE_TESTING_SUPPORT 71 #include <stdio.h> 72 #endif 73 74 #ifndef NVN_NUM_GATT_SERVER_CCC 75 #define NVN_NUM_GATT_SERVER_CCC 20 76 #endif 77 78 static void att_run_for_context(hci_connection_t * hci_connection); 79 static att_write_callback_t att_server_write_callback_for_handle(uint16_t handle); 80 static btstack_packet_handler_t att_server_packet_handler_for_handle(uint16_t handle); 81 static void att_server_handle_can_send_now(void); 82 static void att_server_persistent_ccc_restore(hci_connection_t * hci_connection); 83 static void att_server_persistent_ccc_clear(hci_connection_t * hci_connection); 84 static void att_server_handle_att_pdu(hci_connection_t * hci_connection, uint8_t * packet, uint16_t size); 85 86 typedef enum { 87 ATT_SERVER_RUN_PHASE_1_REQUESTS = 0, 88 ATT_SERVER_RUN_PHASE_2_INDICATIONS, 89 ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS, 90 } att_server_run_phase_t; 91 92 // 93 typedef struct { 94 uint32_t seq_nr; 95 uint16_t att_handle; 96 uint8_t value; 97 uint8_t device_index; 98 } persistent_ccc_entry_t; 99 100 // global 101 static btstack_packet_callback_registration_t hci_event_callback_registration; 102 static btstack_packet_callback_registration_t sm_event_callback_registration; 103 static btstack_packet_handler_t att_client_packet_handler = NULL; 104 static btstack_linked_list_t service_handlers; 105 static btstack_context_callback_registration_t att_client_waiting_for_can_send_registration; 106 107 static att_read_callback_t att_server_client_read_callback; 108 static att_write_callback_t att_server_client_write_callback; 109 110 // round robin 111 static hci_con_handle_t att_server_last_can_send_now = HCI_CON_HANDLE_INVALID; 112 113 #ifdef ENABLE_LE_SIGNED_WRITE 114 static hci_connection_t * hci_connection_for_state(att_server_state_t state){ 115 btstack_linked_list_iterator_t it; 116 hci_connections_get_iterator(&it); 117 while(btstack_linked_list_iterator_has_next(&it)){ 118 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 119 att_server_t * att_server = &connection->att_server; 120 if (att_server->state == state) return connection; 121 } 122 return NULL; 123 } 124 #endif 125 126 static void att_server_request_can_send_now(hci_connection_t * hci_connection){ 127 #ifdef ENABLE_GATT_OVER_CLASSIC 128 att_server_t * att_server = &hci_connection->att_server; 129 if (att_server->l2cap_cid != 0){ 130 l2cap_request_can_send_now_event(att_server->l2cap_cid); 131 return; 132 } 133 #endif 134 att_connection_t * att_connection = &hci_connection->att_connection; 135 att_dispatch_server_request_can_send_now_event(att_connection->con_handle); 136 } 137 138 static bool att_server_can_send_packet(hci_connection_t * hci_connection){ 139 #ifdef ENABLE_GATT_OVER_CLASSIC 140 att_server_t * att_server = &hci_connection->att_server; 141 if (att_server->l2cap_cid != 0){ 142 return l2cap_can_send_packet_now(att_server->l2cap_cid) != 0; 143 } 144 #endif 145 att_connection_t * att_connection = &hci_connection->att_connection; 146 return att_dispatch_server_can_send_now(att_connection->con_handle) != 0; 147 } 148 149 static void att_handle_value_indication_notify_client(uint8_t status, uint16_t client_handle, uint16_t attribute_handle){ 150 btstack_packet_handler_t packet_handler = att_server_packet_handler_for_handle(attribute_handle); 151 if (!packet_handler) return; 152 153 uint8_t event[7]; 154 int pos = 0; 155 event[pos++] = ATT_EVENT_HANDLE_VALUE_INDICATION_COMPLETE; 156 event[pos++] = sizeof(event) - 2u; 157 event[pos++] = status; 158 little_endian_store_16(event, pos, client_handle); 159 pos += 2; 160 little_endian_store_16(event, pos, attribute_handle); 161 (*packet_handler)(HCI_EVENT_PACKET, 0, &event[0], sizeof(event)); 162 } 163 164 static void att_emit_event_to_all(const uint8_t * event, uint16_t size){ 165 // dispatch to app level handler 166 if (att_client_packet_handler != NULL){ 167 (*att_client_packet_handler)(HCI_EVENT_PACKET, 0, (uint8_t*) event, size); 168 } 169 170 // dispatch to service handlers 171 btstack_linked_list_iterator_t it; 172 btstack_linked_list_iterator_init(&it, &service_handlers); 173 while (btstack_linked_list_iterator_has_next(&it)){ 174 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 175 if (!handler->packet_handler) continue; 176 (*handler->packet_handler)(HCI_EVENT_PACKET, 0, (uint8_t*) event, size); 177 } 178 } 179 180 static void att_emit_mtu_event(hci_con_handle_t con_handle, uint16_t mtu){ 181 uint8_t event[6]; 182 int pos = 0; 183 event[pos++] = ATT_EVENT_MTU_EXCHANGE_COMPLETE; 184 event[pos++] = sizeof(event) - 2u; 185 little_endian_store_16(event, pos, con_handle); 186 pos += 2; 187 little_endian_store_16(event, pos, mtu); 188 189 // also dispatch to GATT Clients 190 att_dispatch_server_mtu_exchanged(con_handle, mtu); 191 192 // dispatch to app level handler and service handlers 193 att_emit_event_to_all(&event[0], sizeof(event)); 194 } 195 196 static void att_emit_can_send_now_event(void * context){ 197 UNUSED(context); 198 if (!att_client_packet_handler) return; 199 200 uint8_t event[] = { ATT_EVENT_CAN_SEND_NOW, 0}; 201 (*att_client_packet_handler)(HCI_EVENT_PACKET, 0, &event[0], sizeof(event)); 202 } 203 204 static void att_emit_connected_event(hci_connection_t * hci_connection){ 205 att_server_t * att_server = &hci_connection->att_server; 206 att_connection_t * att_connection = &hci_connection->att_connection; 207 uint8_t event[11]; 208 int pos = 0; 209 event[pos++] = ATT_EVENT_CONNECTED; 210 event[pos++] = sizeof(event) - 2u; 211 event[pos++] = att_server->peer_addr_type; 212 reverse_bd_addr(att_server->peer_address, &event[pos]); 213 pos += 6; 214 little_endian_store_16(event, pos, att_connection->con_handle); 215 pos += 2; 216 217 // dispatch to app level handler and service handlers 218 att_emit_event_to_all(&event[0], sizeof(event)); 219 } 220 221 222 static void att_emit_disconnected_event(uint16_t con_handle){ 223 uint8_t event[4]; 224 int pos = 0; 225 event[pos++] = ATT_EVENT_DISCONNECTED; 226 event[pos++] = sizeof(event) - 2u; 227 little_endian_store_16(event, pos, con_handle); 228 pos += 2; 229 230 // dispatch to app level handler and service handlers 231 att_emit_event_to_all(&event[0], sizeof(event)); 232 } 233 234 static void att_handle_value_indication_timeout(btstack_timer_source_t *ts){ 235 void * context = btstack_run_loop_get_timer_context(ts); 236 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) context; 237 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 238 if (!hci_connection) return; 239 // @note: after a transaction timeout, no more requests shall be sent over this ATT Bearer 240 // (that's why we don't reset the value_indication_handle) 241 att_server_t * att_server = &hci_connection->att_server; 242 uint16_t att_handle = att_server->value_indication_handle; 243 att_connection_t * att_connection = &hci_connection->att_connection; 244 att_handle_value_indication_notify_client((uint8_t)ATT_HANDLE_VALUE_INDICATION_TIMEOUT, att_connection->con_handle, att_handle); 245 } 246 247 static void att_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 248 249 UNUSED(channel); // ok: there is no channel 250 UNUSED(size); // ok: handling own l2cap events 251 252 att_server_t * att_server; 253 att_connection_t * att_connection; 254 hci_con_handle_t con_handle; 255 hci_connection_t * hci_connection; 256 #ifdef ENABLE_GATT_OVER_CLASSIC 257 bd_addr_t address; 258 btstack_linked_list_iterator_t it; 259 #endif 260 261 switch (packet_type) { 262 263 case HCI_EVENT_PACKET: 264 switch (hci_event_packet_get_type(packet)) { 265 266 #ifdef ENABLE_GATT_OVER_CLASSIC 267 case L2CAP_EVENT_INCOMING_CONNECTION: 268 l2cap_event_incoming_connection_get_address(packet, address); 269 l2cap_accept_connection(channel); 270 log_info("Accept incoming connection from %s", bd_addr_to_str(address)); 271 break; 272 case L2CAP_EVENT_CHANNEL_OPENED: 273 con_handle = l2cap_event_channel_opened_get_handle(packet); 274 hci_connection = hci_connection_for_handle(con_handle); 275 if (!hci_connection) break; 276 att_server = &hci_connection->att_server; 277 // store connection info 278 att_server->peer_addr_type = BD_ADDR_TYPE_ACL; 279 l2cap_event_channel_opened_get_address(packet, att_server->peer_address); 280 att_connection = &hci_connection->att_connection; 281 att_connection->con_handle = con_handle; 282 att_server->l2cap_cid = l2cap_event_channel_opened_get_local_cid(packet); 283 // reset connection properties 284 att_server->state = ATT_SERVER_IDLE; 285 att_connection->mtu = l2cap_event_channel_opened_get_remote_mtu(packet); 286 att_connection->max_mtu = l2cap_max_mtu(); 287 if (att_connection->max_mtu > ATT_REQUEST_BUFFER_SIZE){ 288 att_connection->max_mtu = ATT_REQUEST_BUFFER_SIZE; 289 } 290 291 log_info("Connection opened %s, l2cap cid %04x, mtu %u", bd_addr_to_str(address), att_server->l2cap_cid, att_connection->mtu); 292 293 // update security params 294 att_connection->encryption_key_size = gap_encryption_key_size(con_handle); 295 att_connection->authenticated = gap_authenticated(con_handle); 296 att_connection->secure_connection = gap_secure_connection(con_handle); 297 log_info("encrypted key size %u, authenticated %u, secure connection %u", 298 att_connection->encryption_key_size, att_connection->authenticated, att_connection->secure_connection); 299 300 // notify connection opened 301 att_emit_connected_event(hci_connection); 302 303 // restore persisten ccc if encrypted 304 if ( gap_security_level(con_handle) >= LEVEL_2){ 305 att_server_persistent_ccc_restore(hci_connection); 306 } 307 // TODO: what to do about le device db? 308 att_server->pairing_active = 0; 309 break; 310 case L2CAP_EVENT_CAN_SEND_NOW: 311 att_server_handle_can_send_now(); 312 break; 313 314 #endif 315 case HCI_EVENT_LE_META: 316 switch (packet[2]) { 317 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 318 con_handle = little_endian_read_16(packet, 4); 319 hci_connection = hci_connection_for_handle(con_handle); 320 if (!hci_connection) break; 321 att_server = &hci_connection->att_server; 322 // store connection info 323 att_server->peer_addr_type = packet[7]; 324 reverse_bd_addr(&packet[8], att_server->peer_address); 325 att_connection = &hci_connection->att_connection; 326 att_connection->con_handle = con_handle; 327 // reset connection properties 328 att_server->state = ATT_SERVER_IDLE; 329 att_connection->mtu = ATT_DEFAULT_MTU; 330 att_connection->max_mtu = l2cap_max_le_mtu(); 331 if (att_connection->max_mtu > ATT_REQUEST_BUFFER_SIZE){ 332 att_connection->max_mtu = ATT_REQUEST_BUFFER_SIZE; 333 } 334 att_connection->encryption_key_size = 0u; 335 att_connection->authenticated = 0u; 336 att_connection->authorized = 0u; 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 = 0u; 340 att_server->pairing_active = 0u; 341 // notify all - old 342 att_emit_event_to_all(packet, size); 343 // notify all - new 344 att_emit_connected_event(hci_connection); 345 break; 346 347 default: 348 break; 349 } 350 break; 351 352 case HCI_EVENT_ENCRYPTION_CHANGE: 353 case HCI_EVENT_ENCRYPTION_CHANGE_V2: 354 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 355 // check handle 356 con_handle = little_endian_read_16(packet, 3); 357 hci_connection = hci_connection_for_handle(con_handle); 358 if (!hci_connection) break; 359 if (gap_get_connection_type(con_handle) != GAP_CONNECTION_LE) break; 360 // update security params 361 att_server = &hci_connection->att_server; 362 att_connection = &hci_connection->att_connection; 363 att_connection->encryption_key_size = gap_encryption_key_size(con_handle); 364 att_connection->authenticated = gap_authenticated(con_handle) ? 1 : 0; 365 att_connection->secure_connection = gap_secure_connection(con_handle) ? 1 : 0; 366 log_info("encrypted key size %u, authenticated %u, secure connection %u", 367 att_connection->encryption_key_size, att_connection->authenticated, att_connection->secure_connection); 368 if (hci_event_packet_get_type(packet) == HCI_EVENT_ENCRYPTION_CHANGE){ 369 // restore CCC values when encrypted for LE Connections 370 if (hci_event_encryption_change_get_encryption_enabled(packet)){ 371 att_server_persistent_ccc_restore(hci_connection); 372 } 373 } 374 att_run_for_context(hci_connection); 375 break; 376 377 case HCI_EVENT_DISCONNECTION_COMPLETE: 378 // check handle 379 con_handle = hci_event_disconnection_complete_get_connection_handle(packet); 380 hci_connection = hci_connection_for_handle(con_handle); 381 if (!hci_connection) break; 382 att_server = &hci_connection->att_server; 383 att_connection = &hci_connection->att_connection; 384 att_clear_transaction_queue(att_connection); 385 att_connection->con_handle = 0; 386 att_server->pairing_active = 0; 387 att_server->state = ATT_SERVER_IDLE; 388 if (att_server->value_indication_handle != 0u){ 389 btstack_run_loop_remove_timer(&att_server->value_indication_timer); 390 uint16_t att_handle = att_server->value_indication_handle; 391 att_server->value_indication_handle = 0u; // reset error state 392 att_handle_value_indication_notify_client((uint8_t)ATT_HANDLE_VALUE_INDICATION_DISCONNECT, att_connection->con_handle, att_handle); 393 } 394 // notify all - new 395 att_emit_disconnected_event(con_handle); 396 // notify all - old 397 att_emit_event_to_all(packet, size); 398 break; 399 400 // Identity Resolving 401 case SM_EVENT_IDENTITY_RESOLVING_STARTED: 402 con_handle = sm_event_identity_resolving_started_get_handle(packet); 403 hci_connection = hci_connection_for_handle(con_handle); 404 if (!hci_connection) break; 405 att_server = &hci_connection->att_server; 406 log_info("SM_EVENT_IDENTITY_RESOLVING_STARTED"); 407 att_server->ir_lookup_active = 1; 408 break; 409 case SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED: 410 con_handle = sm_event_identity_created_get_handle(packet); 411 hci_connection = hci_connection_for_handle(con_handle); 412 if (!hci_connection) return; 413 att_server = &hci_connection->att_server; 414 att_server->ir_lookup_active = 0; 415 att_server->ir_le_device_db_index = sm_event_identity_resolving_succeeded_get_index(packet); 416 log_info("SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED"); 417 att_run_for_context(hci_connection); 418 break; 419 case SM_EVENT_IDENTITY_RESOLVING_FAILED: 420 con_handle = sm_event_identity_resolving_failed_get_handle(packet); 421 hci_connection = hci_connection_for_handle(con_handle); 422 if (!hci_connection) break; 423 att_server = &hci_connection->att_server; 424 log_info("SM_EVENT_IDENTITY_RESOLVING_FAILED"); 425 att_server->ir_lookup_active = 0; 426 att_server->ir_le_device_db_index = -1; 427 att_run_for_context(hci_connection); 428 break; 429 430 // Pairing started - delete stored CCC values 431 // - assumes pairing indicates either new device or re-pairing, in both cases there should be no stored CCC values 432 // - assumes that all events have the con handle as the first field 433 case SM_EVENT_JUST_WORKS_REQUEST: 434 case SM_EVENT_PASSKEY_DISPLAY_NUMBER: 435 case SM_EVENT_PASSKEY_INPUT_NUMBER: 436 case SM_EVENT_NUMERIC_COMPARISON_REQUEST: 437 con_handle = sm_event_just_works_request_get_handle(packet); 438 hci_connection = hci_connection_for_handle(con_handle); 439 if (!hci_connection) break; 440 att_server = &hci_connection->att_server; 441 att_server->pairing_active = 1; 442 log_info("SM Pairing started"); 443 if (att_server->ir_le_device_db_index < 0) break; 444 att_server_persistent_ccc_clear(hci_connection); 445 // index not valid anymore 446 att_server->ir_le_device_db_index = -1; 447 break; 448 449 // Bonding completed 450 case SM_EVENT_IDENTITY_CREATED: 451 con_handle = sm_event_identity_created_get_handle(packet); 452 hci_connection = hci_connection_for_handle(con_handle); 453 if (!hci_connection) return; 454 att_server = &hci_connection->att_server; 455 att_server->pairing_active = 0; 456 att_server->ir_le_device_db_index = sm_event_identity_created_get_index(packet); 457 att_run_for_context(hci_connection); 458 break; 459 460 // Pairing complete (with/without bonding=storing of pairing information) 461 case SM_EVENT_PAIRING_COMPLETE: 462 con_handle = sm_event_pairing_complete_get_handle(packet); 463 hci_connection = hci_connection_for_handle(con_handle); 464 if (!hci_connection) return; 465 att_server = &hci_connection->att_server; 466 att_server->pairing_active = 0; 467 att_run_for_context(hci_connection); 468 break; 469 470 // Authorization 471 case SM_EVENT_AUTHORIZATION_RESULT: { 472 con_handle = sm_event_authorization_result_get_handle(packet); 473 hci_connection = hci_connection_for_handle(con_handle); 474 if (!hci_connection) break; 475 att_server = &hci_connection->att_server; 476 att_connection = &hci_connection->att_connection; 477 att_connection->authorized = sm_event_authorization_result_get_authorization_result(packet); 478 att_server_request_can_send_now(hci_connection); 479 break; 480 } 481 default: 482 break; 483 } 484 break; 485 #ifdef ENABLE_GATT_OVER_CLASSIC 486 case L2CAP_DATA_PACKET: 487 hci_connections_get_iterator(&it); 488 while(btstack_linked_list_iterator_has_next(&it)){ 489 hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 490 att_server = &hci_connection->att_server; 491 if (att_server->l2cap_cid == channel) { 492 att_server_handle_att_pdu(hci_connection, packet, size); 493 break; 494 } 495 } 496 break; 497 #endif 498 499 default: 500 break; 501 } 502 } 503 504 #ifdef ENABLE_LE_SIGNED_WRITE 505 static void att_signed_write_handle_cmac_result(uint8_t hash[8]){ 506 507 hci_connection_t * hci_connection = hci_connection_for_state(ATT_SERVER_W4_SIGNED_WRITE_VALIDATION); 508 if (!hci_connection) return; 509 att_server_t * att_server = &hci_connection->att_server; 510 511 uint8_t hash_flipped[8]; 512 reverse_64(hash, hash_flipped); 513 if (memcmp(hash_flipped, &att_server->request_buffer[att_server->request_size-8], 8)){ 514 log_info("ATT Signed Write, invalid signature"); 515 #ifdef ENABLE_TESTING_SUPPORT 516 printf("ATT Signed Write, invalid signature\n"); 517 #endif 518 att_server->state = ATT_SERVER_IDLE; 519 return; 520 } 521 log_info("ATT Signed Write, valid signature"); 522 #ifdef ENABLE_TESTING_SUPPORT 523 printf("ATT Signed Write, valid signature\n"); 524 #endif 525 526 // update sequence number 527 uint32_t counter_packet = little_endian_read_32(att_server->request_buffer, att_server->request_size-12); 528 le_device_db_remote_counter_set(att_server->ir_le_device_db_index, counter_packet+1); 529 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 530 att_server_request_can_send_now(hci_connection); 531 } 532 #endif 533 534 // pre: att_server->state == ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED 535 // pre: can send now 536 // returns: 1 if packet was sent 537 static int att_server_process_validated_request(hci_connection_t * hci_connection){ 538 att_server_t * att_server = & hci_connection->att_server; 539 att_connection_t * att_connection = &hci_connection->att_connection; 540 541 l2cap_reserve_packet_buffer(); 542 uint8_t * att_response_buffer = l2cap_get_outgoing_buffer(); 543 uint16_t att_response_size = att_handle_request(att_connection, att_server->request_buffer, att_server->request_size, att_response_buffer); 544 545 #ifdef ENABLE_ATT_DELAYED_RESPONSE 546 if ((att_response_size == ATT_READ_RESPONSE_PENDING) || (att_response_size == ATT_INTERNAL_WRITE_RESPONSE_PENDING)){ 547 // update state 548 att_server->state = ATT_SERVER_RESPONSE_PENDING; 549 550 // callback with handle ATT_READ_RESPONSE_PENDING for reads 551 if (att_response_size == ATT_READ_RESPONSE_PENDING){ 552 att_server_client_read_callback(att_connection->con_handle, ATT_READ_RESPONSE_PENDING, 0, NULL, 0); 553 } 554 555 // free reserved buffer 556 l2cap_release_packet_buffer(); 557 return 0; 558 } 559 #endif 560 561 // intercept "insufficient authorization" for authenticated connections to allow for user authorization 562 if ((att_response_size >= 4u) 563 && (att_response_buffer[0] == ATT_ERROR_RESPONSE) 564 && (att_response_buffer[4] == ATT_ERROR_INSUFFICIENT_AUTHORIZATION) 565 && (att_connection->authenticated != 0u)){ 566 567 switch (gap_authorization_state(att_connection->con_handle)){ 568 case AUTHORIZATION_UNKNOWN: 569 l2cap_release_packet_buffer(); 570 sm_request_pairing(att_connection->con_handle); 571 return 0; 572 case AUTHORIZATION_PENDING: 573 l2cap_release_packet_buffer(); 574 return 0; 575 default: 576 break; 577 } 578 } 579 580 att_server->state = ATT_SERVER_IDLE; 581 if (att_response_size == 0u) { 582 l2cap_release_packet_buffer(); 583 return 0; 584 } 585 586 #ifdef ENABLE_GATT_OVER_CLASSIC 587 if (att_server->l2cap_cid != 0u){ 588 l2cap_send_prepared(att_server->l2cap_cid, att_response_size); 589 } else 590 #endif 591 { 592 l2cap_send_prepared_connectionless(att_connection->con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, att_response_size); 593 } 594 595 // notify client about MTU exchange result 596 if (att_response_buffer[0] == ATT_EXCHANGE_MTU_RESPONSE){ 597 att_emit_mtu_event(att_connection->con_handle, att_connection->mtu); 598 } 599 return 1; 600 } 601 602 #ifdef ENABLE_ATT_DELAYED_RESPONSE 603 uint8_t att_server_response_ready(hci_con_handle_t con_handle){ 604 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 605 if (!hci_connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 606 att_server_t * att_server = &hci_connection->att_server; 607 608 if (att_server->state != ATT_SERVER_RESPONSE_PENDING) return ERROR_CODE_COMMAND_DISALLOWED; 609 610 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 611 att_server_request_can_send_now(hci_connection); 612 return ERROR_CODE_SUCCESS; 613 } 614 #endif 615 616 static void att_run_for_context(hci_connection_t * hci_connection){ 617 att_server_t * att_server = &hci_connection->att_server; 618 att_connection_t * att_connection = &hci_connection->att_connection; 619 switch (att_server->state){ 620 case ATT_SERVER_REQUEST_RECEIVED: 621 622 #ifdef ENABLE_GATT_OVER_CLASSIC 623 if (att_server->l2cap_cid != 0){ 624 // ok 625 } else 626 #endif 627 { 628 // wait until re-encryption as central is complete 629 if (gap_reconnect_security_setup_active(att_connection->con_handle)) break; 630 } 631 632 // wait until pairing is complete 633 if (att_server->pairing_active) break; 634 635 #ifdef ENABLE_LE_SIGNED_WRITE 636 if (att_server->request_buffer[0] == ATT_SIGNED_WRITE_COMMAND){ 637 log_info("ATT Signed Write!"); 638 if (!sm_cmac_ready()) { 639 log_info("ATT Signed Write, sm_cmac engine not ready. Abort"); 640 att_server->state = ATT_SERVER_IDLE; 641 return; 642 } 643 if (att_server->request_size < (3 + 12)) { 644 log_info("ATT Signed Write, request to short. Abort."); 645 att_server->state = ATT_SERVER_IDLE; 646 return; 647 } 648 if (att_server->ir_lookup_active){ 649 return; 650 } 651 if (att_server->ir_le_device_db_index < 0){ 652 log_info("ATT Signed Write, CSRK not available"); 653 att_server->state = ATT_SERVER_IDLE; 654 return; 655 } 656 657 // check counter 658 uint32_t counter_packet = little_endian_read_32(att_server->request_buffer, att_server->request_size-12); 659 uint32_t counter_db = le_device_db_remote_counter_get(att_server->ir_le_device_db_index); 660 log_info("ATT Signed Write, DB counter %"PRIu32", packet counter %"PRIu32, counter_db, counter_packet); 661 if (counter_packet < counter_db){ 662 log_info("ATT Signed Write, db reports higher counter, abort"); 663 att_server->state = ATT_SERVER_IDLE; 664 return; 665 } 666 667 // signature is { sequence counter, secure hash } 668 sm_key_t csrk; 669 le_device_db_remote_csrk_get(att_server->ir_le_device_db_index, csrk); 670 att_server->state = ATT_SERVER_W4_SIGNED_WRITE_VALIDATION; 671 log_info("Orig Signature: "); 672 log_info_hexdump( &att_server->request_buffer[att_server->request_size-8], 8); 673 uint16_t attribute_handle = little_endian_read_16(att_server->request_buffer, 1); 674 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); 675 return; 676 } 677 #endif 678 // move on 679 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 680 att_server_request_can_send_now(hci_connection); 681 break; 682 683 default: 684 break; 685 } 686 } 687 688 static bool att_server_data_ready_for_phase(att_server_t * att_server, att_server_run_phase_t phase){ 689 switch (phase){ 690 case ATT_SERVER_RUN_PHASE_1_REQUESTS: 691 return att_server->state == ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 692 case ATT_SERVER_RUN_PHASE_2_INDICATIONS: 693 return (!btstack_linked_list_empty(&att_server->indication_requests) && (att_server->value_indication_handle == 0u)); 694 case ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS: 695 return (!btstack_linked_list_empty(&att_server->notification_requests)); 696 default: 697 btstack_assert(false); 698 return false; 699 } 700 } 701 702 static void att_server_trigger_send_for_phase(hci_connection_t * hci_connection, att_server_run_phase_t phase){ 703 btstack_context_callback_registration_t * client; 704 att_server_t * att_server = &hci_connection->att_server; 705 switch (phase){ 706 case ATT_SERVER_RUN_PHASE_1_REQUESTS: 707 att_server_process_validated_request(hci_connection); 708 break; 709 case ATT_SERVER_RUN_PHASE_2_INDICATIONS: 710 client = (btstack_context_callback_registration_t*) att_server->indication_requests; 711 btstack_linked_list_remove(&att_server->indication_requests, (btstack_linked_item_t *) client); 712 client->callback(client->context); 713 break; 714 case ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS: 715 client = (btstack_context_callback_registration_t*) att_server->notification_requests; 716 btstack_linked_list_remove(&att_server->notification_requests, (btstack_linked_item_t *) client); 717 client->callback(client->context); 718 break; 719 default: 720 btstack_assert(false); 721 break; 722 } 723 } 724 725 static void att_server_handle_can_send_now(void){ 726 727 hci_con_handle_t last_send_con_handle = HCI_CON_HANDLE_INVALID; 728 hci_connection_t * request_hci_connection = NULL; 729 bool can_send_now = true; 730 uint8_t phase_index; 731 732 for (phase_index = ATT_SERVER_RUN_PHASE_1_REQUESTS; phase_index <= ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS; phase_index++){ 733 att_server_run_phase_t phase = (att_server_run_phase_t) phase_index; 734 hci_con_handle_t skip_connections_until = att_server_last_can_send_now; 735 while (true){ 736 btstack_linked_list_iterator_t it; 737 hci_connections_get_iterator(&it); 738 while(btstack_linked_list_iterator_has_next(&it)){ 739 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 740 att_server_t * att_server = &connection->att_server; 741 att_connection_t * att_connection = &connection->att_connection; 742 743 bool data_ready = att_server_data_ready_for_phase(att_server, phase); 744 745 // log_debug("phase %u, handle 0x%04x, skip until 0x%04x, data ready %u", phase, att_connection->con_handle, skip_connections_until, data_ready); 746 747 // skip until last sender found (which is also skipped) 748 if (skip_connections_until != HCI_CON_HANDLE_INVALID){ 749 if (data_ready && (request_hci_connection == NULL)){ 750 request_hci_connection = connection; 751 } 752 if (skip_connections_until == att_connection->con_handle){ 753 skip_connections_until = HCI_CON_HANDLE_INVALID; 754 } 755 continue; 756 }; 757 758 if (data_ready){ 759 if (can_send_now){ 760 att_server_trigger_send_for_phase(connection, phase); 761 last_send_con_handle = att_connection->con_handle; 762 can_send_now = att_server_can_send_packet(connection); 763 data_ready = att_server_data_ready_for_phase(att_server, phase); 764 if (data_ready && (request_hci_connection == NULL)){ 765 request_hci_connection = connection; 766 } 767 } else { 768 request_hci_connection = connection; 769 break; 770 } 771 } 772 } 773 774 // stop skipping (handles disconnect by last send connection) 775 skip_connections_until = HCI_CON_HANDLE_INVALID; 776 777 // Exit loop, if we cannot send 778 if (!can_send_now) break; 779 780 // Exit loop, if we can send but there are also no further request 781 if (request_hci_connection == NULL) break; 782 783 // Finally, if we still can send and there are requests, just try again 784 request_hci_connection = NULL; 785 } 786 // update last send con handle for round robin 787 if (last_send_con_handle != HCI_CON_HANDLE_INVALID){ 788 att_server_last_can_send_now = last_send_con_handle; 789 } 790 } 791 792 if (request_hci_connection == NULL) return; 793 att_server_request_can_send_now(request_hci_connection); 794 } 795 796 static void att_server_handle_att_pdu(hci_connection_t * hci_connection, uint8_t * packet, uint16_t size){ 797 att_server_t * att_server = &hci_connection->att_server; 798 att_connection_t * att_connection = &hci_connection->att_connection; 799 800 uint8_t opcode = packet[0u]; 801 uint8_t method = opcode & 0x03fu; 802 bool invalid = method > ATT_MULTIPLE_HANDLE_VALUE_NTF; 803 bool command = (opcode & 0x40u) != 0u; 804 805 // ignore invalid commands 806 if (invalid && command){ 807 return; 808 } 809 810 // handle value indication confirms 811 if ((opcode == ATT_HANDLE_VALUE_CONFIRMATION) && (att_server->value_indication_handle != 0u)){ 812 btstack_run_loop_remove_timer(&att_server->value_indication_timer); 813 uint16_t att_handle = att_server->value_indication_handle; 814 att_server->value_indication_handle = 0u; 815 att_handle_value_indication_notify_client(0u, att_connection->con_handle, att_handle); 816 att_server_request_can_send_now(hci_connection); 817 return; 818 } 819 820 // directly process command 821 // note: signed write cannot be handled directly as authentication needs to be verified 822 if (opcode == ATT_WRITE_COMMAND){ 823 att_handle_request(att_connection, packet, size, NULL); 824 return; 825 } 826 827 // check size 828 if (size > sizeof(att_server->request_buffer)) { 829 log_info("drop att pdu 0x%02x as size %u > att_server->request_buffer %u", packet[0], size, (int) sizeof(att_server->request_buffer)); 830 return; 831 } 832 833 #ifdef ENABLE_LE_SIGNED_WRITE 834 // abort signed write validation if a new request comes in (but finish previous signed write if possible) 835 if (att_server->state == ATT_SERVER_W4_SIGNED_WRITE_VALIDATION){ 836 if (packet[0] == ATT_SIGNED_WRITE_COMMAND){ 837 log_info("skip new signed write request as previous is in validation"); 838 return; 839 } else { 840 log_info("abort signed write validation to process new request"); 841 att_server->state = ATT_SERVER_IDLE; 842 } 843 } 844 #endif 845 // last request still in processing? 846 if (att_server->state != ATT_SERVER_IDLE){ 847 log_info("skip att pdu 0x%02x as server not idle (state %u)", packet[0], att_server->state); 848 return; 849 } 850 851 // store request 852 att_server->state = ATT_SERVER_REQUEST_RECEIVED; 853 att_server->request_size = size; 854 (void)memcpy(att_server->request_buffer, packet, size); 855 856 att_run_for_context(hci_connection); 857 } 858 859 static void att_packet_handler(uint8_t packet_type, uint16_t handle, uint8_t *packet, uint16_t size){ 860 hci_connection_t * hci_connection; 861 att_connection_t * att_connection; 862 863 switch (packet_type){ 864 case HCI_EVENT_PACKET: 865 switch (packet[0]){ 866 case L2CAP_EVENT_CAN_SEND_NOW: 867 att_server_handle_can_send_now(); 868 break; 869 case ATT_EVENT_MTU_EXCHANGE_COMPLETE: 870 // GATT client has negotiated the mtu for this connection 871 hci_connection = hci_connection_for_handle(handle); 872 if (!hci_connection) break; 873 att_connection = &hci_connection->att_connection; 874 att_connection->mtu = little_endian_read_16(packet, 4); 875 break; 876 default: 877 break; 878 } 879 break; 880 881 case ATT_DATA_PACKET: 882 log_debug("ATT Packet, handle 0x%04x", handle); 883 hci_connection = hci_connection_for_handle(handle); 884 if (!hci_connection) break; 885 886 att_server_handle_att_pdu(hci_connection, packet, size); 887 break; 888 889 default: 890 break; 891 } 892 } 893 894 // --------------------- 895 // persistent CCC writes 896 static uint32_t att_server_persistent_ccc_tag_for_index(uint8_t index){ 897 return ('B' << 24u) | ('T' << 16u) | ('C' << 8u) | index; 898 } 899 900 static void att_server_persistent_ccc_write(hci_con_handle_t con_handle, uint16_t att_handle, uint16_t value){ 901 // lookup att_server instance 902 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 903 if (!hci_connection) return; 904 att_server_t * att_server = &hci_connection->att_server; 905 int le_device_index = att_server->ir_le_device_db_index; 906 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); 907 908 // check if bonded 909 if (le_device_index < 0) return; 910 911 // get btstack_tlv 912 const btstack_tlv_t * tlv_impl = NULL; 913 void * tlv_context; 914 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 915 if (!tlv_impl) return; 916 917 // update ccc tag 918 int index; 919 uint32_t highest_seq_nr = 0; 920 uint32_t lowest_seq_nr = 0; 921 uint32_t tag_for_lowest_seq_nr = 0; 922 uint32_t tag_for_empty = 0; 923 persistent_ccc_entry_t entry; 924 for (index=0; index<NVN_NUM_GATT_SERVER_CCC; index++){ 925 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 926 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 927 928 // empty/invalid tag 929 if (len != sizeof(persistent_ccc_entry_t)){ 930 tag_for_empty = tag; 931 continue; 932 } 933 // update highest seq nr 934 if (entry.seq_nr > highest_seq_nr){ 935 highest_seq_nr = entry.seq_nr; 936 } 937 // find entry with lowest seq nr 938 if ((tag_for_lowest_seq_nr == 0u) || (entry.seq_nr < lowest_seq_nr)){ 939 tag_for_lowest_seq_nr = tag; 940 lowest_seq_nr = entry.seq_nr; 941 } 942 943 if (entry.device_index != le_device_index) continue; 944 if (entry.att_handle != att_handle) continue; 945 946 // found matching entry 947 if (value != 0){ 948 // update 949 if (entry.value == value) { 950 log_info("CCC Index %u: Up-to-date", index); 951 return; 952 } 953 entry.value = (uint8_t) value; 954 entry.seq_nr = highest_seq_nr + 1u; 955 log_info("CCC Index %u: Store", index); 956 int result = tlv_impl->store_tag(tlv_context, tag, (const uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 957 if (result != 0){ 958 log_error("Store tag index %u failed", index); 959 } 960 } else { 961 // delete 962 log_info("CCC Index %u: Delete", index); 963 tlv_impl->delete_tag(tlv_context, tag); 964 } 965 return; 966 } 967 968 log_info("tag_for_empty %"PRIx32", tag_for_lowest_seq_nr %"PRIx32, tag_for_empty, tag_for_lowest_seq_nr); 969 970 if (value == 0u){ 971 // done 972 return; 973 } 974 975 uint32_t tag_to_use = 0u; 976 if (tag_for_empty != 0u){ 977 tag_to_use = tag_for_empty; 978 } else if (tag_for_lowest_seq_nr){ 979 tag_to_use = tag_for_lowest_seq_nr; 980 } else { 981 // should not happen 982 return; 983 } 984 // store ccc tag 985 entry.seq_nr = highest_seq_nr + 1u; 986 entry.device_index = le_device_index; 987 entry.att_handle = att_handle; 988 entry.value = (uint8_t) value; 989 int result = tlv_impl->store_tag(tlv_context, tag_to_use, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 990 if (result != 0){ 991 log_error("Store tag index %u failed", index); 992 } 993 } 994 995 static void att_server_persistent_ccc_clear(hci_connection_t * hci_connection){ 996 if (!hci_connection) return; 997 att_server_t * att_server = &hci_connection->att_server; 998 999 int le_device_index = att_server->ir_le_device_db_index; 1000 log_info("Clear CCC values of remote %s, le device id %d", bd_addr_to_str(att_server->peer_address), le_device_index); 1001 // check if bonded 1002 if (le_device_index < 0) return; 1003 // get btstack_tlv 1004 const btstack_tlv_t * tlv_impl = NULL; 1005 void * tlv_context; 1006 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 1007 if (!tlv_impl) return; 1008 // get all ccc tag 1009 int index; 1010 persistent_ccc_entry_t entry; 1011 for (index=0;index<NVN_NUM_GATT_SERVER_CCC;index++){ 1012 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 1013 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 1014 if (len != sizeof(persistent_ccc_entry_t)) continue; 1015 if (entry.device_index != le_device_index) continue; 1016 // delete entry 1017 log_info("CCC Index %u: Delete", index); 1018 tlv_impl->delete_tag(tlv_context, tag); 1019 } 1020 } 1021 1022 static void att_server_persistent_ccc_restore(hci_connection_t * hci_connection){ 1023 if (!hci_connection) return; 1024 att_server_t * att_server = &hci_connection->att_server; 1025 att_connection_t * att_connection = &hci_connection->att_connection; 1026 1027 int le_device_index = att_server->ir_le_device_db_index; 1028 log_info("Restore CCC values of remote %s, le device id %d", bd_addr_to_str(att_server->peer_address), le_device_index); 1029 // check if bonded 1030 if (le_device_index < 0) return; 1031 // get btstack_tlv 1032 const btstack_tlv_t * tlv_impl = NULL; 1033 void * tlv_context; 1034 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 1035 if (!tlv_impl) return; 1036 // get all ccc tag 1037 int index; 1038 persistent_ccc_entry_t entry; 1039 for (index=0;index<NVN_NUM_GATT_SERVER_CCC;index++){ 1040 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 1041 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 1042 if (len != sizeof(persistent_ccc_entry_t)) continue; 1043 if (entry.device_index != le_device_index) continue; 1044 // simulate write callback 1045 uint16_t attribute_handle = entry.att_handle; 1046 uint8_t value[2]; 1047 little_endian_store_16(value, 0, entry.value); 1048 att_write_callback_t callback = att_server_write_callback_for_handle(attribute_handle); 1049 if (!callback) continue; 1050 log_info("CCC Index %u: Set Attribute handle 0x%04x to value 0x%04x", index, attribute_handle, entry.value ); 1051 (*callback)(att_connection->con_handle, attribute_handle, ATT_TRANSACTION_MODE_NONE, 0, value, sizeof(value)); 1052 } 1053 } 1054 1055 // persistent CCC writes 1056 // --------------------- 1057 1058 // gatt service management 1059 static att_service_handler_t * att_service_handler_for_handle(uint16_t handle){ 1060 btstack_linked_list_iterator_t it; 1061 btstack_linked_list_iterator_init(&it, &service_handlers); 1062 while (btstack_linked_list_iterator_has_next(&it)){ 1063 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 1064 if (handler->start_handle > handle) continue; 1065 if (handler->end_handle < handle) continue; 1066 return handler; 1067 } 1068 return NULL; 1069 } 1070 static att_read_callback_t att_server_read_callback_for_handle(uint16_t handle){ 1071 att_service_handler_t * handler = att_service_handler_for_handle(handle); 1072 if (handler != NULL) return handler->read_callback; 1073 return att_server_client_read_callback; 1074 } 1075 1076 static att_write_callback_t att_server_write_callback_for_handle(uint16_t handle){ 1077 att_service_handler_t * handler = att_service_handler_for_handle(handle); 1078 if (handler != NULL) return handler->write_callback; 1079 return att_server_client_write_callback; 1080 } 1081 1082 static btstack_packet_handler_t att_server_packet_handler_for_handle(uint16_t handle){ 1083 att_service_handler_t * handler = att_service_handler_for_handle(handle); 1084 if (handler != NULL) return handler->packet_handler; 1085 return att_client_packet_handler; 1086 } 1087 1088 static void att_notify_write_callbacks(hci_con_handle_t con_handle, uint16_t transaction_mode){ 1089 // notify all callbacks 1090 btstack_linked_list_iterator_t it; 1091 btstack_linked_list_iterator_init(&it, &service_handlers); 1092 while (btstack_linked_list_iterator_has_next(&it)){ 1093 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 1094 if (!handler->write_callback) continue; 1095 (*handler->write_callback)(con_handle, 0, transaction_mode, 0, NULL, 0); 1096 } 1097 if (!att_server_client_write_callback) return; 1098 (*att_server_client_write_callback)(con_handle, 0, transaction_mode, 0, NULL, 0); 1099 } 1100 1101 // returns first reported error or 0 1102 static uint8_t att_validate_prepared_write(hci_con_handle_t con_handle){ 1103 btstack_linked_list_iterator_t it; 1104 btstack_linked_list_iterator_init(&it, &service_handlers); 1105 while (btstack_linked_list_iterator_has_next(&it)){ 1106 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 1107 if (!handler->write_callback) continue; 1108 uint8_t error_code = (*handler->write_callback)(con_handle, 0, ATT_TRANSACTION_MODE_VALIDATE, 0, NULL, 0); 1109 if (error_code != 0u) return error_code; 1110 } 1111 if (!att_server_client_write_callback) return 0; 1112 return (*att_server_client_write_callback)(con_handle, 0, ATT_TRANSACTION_MODE_VALIDATE, 0, NULL, 0); 1113 } 1114 1115 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){ 1116 att_read_callback_t callback = att_server_read_callback_for_handle(attribute_handle); 1117 if (!callback) return 0; 1118 return (*callback)(con_handle, attribute_handle, offset, buffer, buffer_size); 1119 } 1120 1121 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){ 1122 switch (transaction_mode){ 1123 case ATT_TRANSACTION_MODE_VALIDATE: 1124 return att_validate_prepared_write(con_handle); 1125 case ATT_TRANSACTION_MODE_EXECUTE: 1126 case ATT_TRANSACTION_MODE_CANCEL: 1127 att_notify_write_callbacks(con_handle, transaction_mode); 1128 return 0; 1129 default: 1130 break; 1131 } 1132 1133 // track CCC writes 1134 if (att_is_persistent_ccc(attribute_handle) && (offset == 0u) && (buffer_size == 2u)){ 1135 att_server_persistent_ccc_write(con_handle, attribute_handle, little_endian_read_16(buffer, 0)); 1136 } 1137 1138 att_write_callback_t callback = att_server_write_callback_for_handle(attribute_handle); 1139 if (!callback) return 0; 1140 return (*callback)(con_handle, attribute_handle, transaction_mode, offset, buffer, buffer_size); 1141 } 1142 1143 /** 1144 * @brief register read/write callbacks for specific handle range 1145 * @param att_service_handler_t 1146 */ 1147 void att_server_register_service_handler(att_service_handler_t * handler){ 1148 if (att_service_handler_for_handle(handler->start_handle) || 1149 att_service_handler_for_handle(handler->end_handle)){ 1150 log_error("handler for range 0x%04x-0x%04x already registered", handler->start_handle, handler->end_handle); 1151 return; 1152 } 1153 btstack_linked_list_add(&service_handlers, (btstack_linked_item_t*) handler); 1154 } 1155 1156 void att_server_init(uint8_t const * db, att_read_callback_t read_callback, att_write_callback_t write_callback){ 1157 1158 // store callbacks 1159 att_server_client_read_callback = read_callback; 1160 att_server_client_write_callback = write_callback; 1161 1162 // register for HCI Events 1163 hci_event_callback_registration.callback = &att_event_packet_handler; 1164 hci_add_event_handler(&hci_event_callback_registration); 1165 1166 // register for SM events 1167 sm_event_callback_registration.callback = &att_event_packet_handler; 1168 sm_add_event_handler(&sm_event_callback_registration); 1169 1170 // and L2CAP ATT Server PDUs 1171 att_dispatch_register_server(att_packet_handler); 1172 1173 #ifdef ENABLE_GATT_OVER_CLASSIC 1174 // setup l2cap service 1175 l2cap_register_service(&att_event_packet_handler, PSM_ATT, 0xffff, gap_get_security_level()); 1176 #endif 1177 1178 att_set_db(db); 1179 att_set_read_callback(att_server_read_callback); 1180 att_set_write_callback(att_server_write_callback); 1181 } 1182 1183 void att_server_register_packet_handler(btstack_packet_handler_t handler){ 1184 att_client_packet_handler = handler; 1185 } 1186 1187 1188 // to be deprecated 1189 int att_server_can_send_packet_now(hci_con_handle_t con_handle){ 1190 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 1191 if (!hci_connection) return 0; 1192 return att_server_can_send_packet(hci_connection); 1193 } 1194 1195 uint8_t att_server_register_can_send_now_callback(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 1196 return att_server_request_to_send_notification(callback_registration, con_handle); 1197 } 1198 1199 void att_server_request_can_send_now_event(hci_con_handle_t con_handle){ 1200 att_client_waiting_for_can_send_registration.callback = &att_emit_can_send_now_event; 1201 att_server_request_to_send_notification(&att_client_waiting_for_can_send_registration, con_handle); 1202 } 1203 // end of deprecated 1204 1205 uint8_t att_server_request_to_send_notification(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 1206 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 1207 if (!hci_connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1208 att_server_t * att_server = &hci_connection->att_server; 1209 bool added = btstack_linked_list_add_tail(&att_server->notification_requests, (btstack_linked_item_t*) callback_registration); 1210 att_server_request_can_send_now(hci_connection); 1211 if (added){ 1212 return ERROR_CODE_SUCCESS; 1213 } else { 1214 return ERROR_CODE_COMMAND_DISALLOWED; 1215 } 1216 } 1217 1218 uint8_t att_server_request_to_send_indication(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 1219 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 1220 if (!hci_connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1221 att_server_t * att_server = &hci_connection->att_server; 1222 bool added = btstack_linked_list_add_tail(&att_server->indication_requests, (btstack_linked_item_t*) callback_registration); 1223 att_server_request_can_send_now(hci_connection); 1224 if (added){ 1225 return ERROR_CODE_SUCCESS; 1226 } else { 1227 return ERROR_CODE_COMMAND_DISALLOWED; 1228 } 1229 } 1230 1231 uint8_t att_server_notify(hci_con_handle_t con_handle, uint16_t attribute_handle, const uint8_t *value, uint16_t value_len){ 1232 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 1233 if (!hci_connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1234 att_connection_t * att_connection = &hci_connection->att_connection; 1235 1236 if (!att_server_can_send_packet(hci_connection)) return BTSTACK_ACL_BUFFERS_FULL; 1237 1238 l2cap_reserve_packet_buffer(); 1239 uint8_t * packet_buffer = l2cap_get_outgoing_buffer(); 1240 uint16_t size = att_prepare_handle_value_notification(att_connection, attribute_handle, value, value_len, packet_buffer); 1241 #ifdef ENABLE_GATT_OVER_CLASSIC 1242 att_server_t * att_server = &hci_connection->att_server; 1243 if (att_server->l2cap_cid != 0){ 1244 return l2cap_send_prepared(att_server->l2cap_cid, size);; 1245 } 1246 #endif 1247 return l2cap_send_prepared_connectionless(att_connection->con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, size); 1248 } 1249 1250 uint8_t att_server_indicate(hci_con_handle_t con_handle, uint16_t attribute_handle, const uint8_t *value, uint16_t value_len){ 1251 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 1252 if (!hci_connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1253 att_server_t * att_server = &hci_connection->att_server; 1254 att_connection_t * att_connection = &hci_connection->att_connection; 1255 1256 if (att_server->value_indication_handle != 0u) return ATT_HANDLE_VALUE_INDICATION_IN_PROGRESS; 1257 if (!att_server_can_send_packet(hci_connection)) return BTSTACK_ACL_BUFFERS_FULL; 1258 1259 // track indication 1260 att_server->value_indication_handle = attribute_handle; 1261 btstack_run_loop_set_timer_handler(&att_server->value_indication_timer, att_handle_value_indication_timeout); 1262 btstack_run_loop_set_timer(&att_server->value_indication_timer, ATT_TRANSACTION_TIMEOUT_MS); 1263 btstack_run_loop_add_timer(&att_server->value_indication_timer); 1264 1265 l2cap_reserve_packet_buffer(); 1266 uint8_t * packet_buffer = l2cap_get_outgoing_buffer(); 1267 uint16_t size = att_prepare_handle_value_indication(att_connection, attribute_handle, value, value_len, packet_buffer); 1268 #ifdef ENABLE_GATT_OVER_CLASSIC 1269 if (att_server->l2cap_cid != 0){ 1270 return l2cap_send_prepared(att_server->l2cap_cid, size);; 1271 } 1272 #endif 1273 l2cap_send_prepared_connectionless(att_connection->con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, size); 1274 return 0; 1275 } 1276 1277 uint16_t att_server_get_mtu(hci_con_handle_t con_handle){ 1278 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 1279 if (!hci_connection) return 0; 1280 att_connection_t * att_connection = &hci_connection->att_connection; 1281 return att_connection->mtu; 1282 } 1283