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 "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 #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 #ifdef ENABLE_GATT_OVER_CLASSIC 124 att_server_t * att_server = &hci_connection->att_server; 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_connection_t * att_connection = &hci_connection->att_connection; 131 att_dispatch_server_request_can_send_now_event(att_connection->con_handle); 132 } 133 134 static bool att_server_can_send_packet(hci_connection_t * hci_connection){ 135 #ifdef ENABLE_GATT_OVER_CLASSIC 136 att_server_t * att_server = &hci_connection->att_server; 137 if (att_server->l2cap_cid != 0){ 138 return l2cap_can_send_packet_now(att_server->l2cap_cid) != 0; 139 } 140 #endif 141 att_connection_t * att_connection = &hci_connection->att_connection; 142 return att_dispatch_server_can_send_now(att_connection->con_handle) != 0; 143 } 144 145 static void att_handle_value_indication_notify_client(uint8_t status, uint16_t client_handle, uint16_t attribute_handle){ 146 btstack_packet_handler_t packet_handler = att_server_packet_handler_for_handle(attribute_handle); 147 if (!packet_handler) return; 148 149 uint8_t event[7]; 150 int pos = 0; 151 event[pos++] = ATT_EVENT_HANDLE_VALUE_INDICATION_COMPLETE; 152 event[pos++] = sizeof(event) - 2u; 153 event[pos++] = status; 154 little_endian_store_16(event, pos, client_handle); 155 pos += 2; 156 little_endian_store_16(event, pos, attribute_handle); 157 (*packet_handler)(HCI_EVENT_PACKET, 0, &event[0], sizeof(event)); 158 } 159 160 static void att_emit_event_to_all(const uint8_t * event, uint16_t size){ 161 // dispatch to app level handler 162 if (att_client_packet_handler != NULL){ 163 (*att_client_packet_handler)(HCI_EVENT_PACKET, 0, (uint8_t*) event, size); 164 } 165 166 // dispatch to service handlers 167 btstack_linked_list_iterator_t it; 168 btstack_linked_list_iterator_init(&it, &service_handlers); 169 while (btstack_linked_list_iterator_has_next(&it)){ 170 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 171 if (!handler->packet_handler) continue; 172 (*handler->packet_handler)(HCI_EVENT_PACKET, 0, (uint8_t*) event, size); 173 } 174 } 175 176 static void att_emit_mtu_event(hci_con_handle_t con_handle, uint16_t mtu){ 177 uint8_t event[6]; 178 int pos = 0; 179 event[pos++] = ATT_EVENT_MTU_EXCHANGE_COMPLETE; 180 event[pos++] = sizeof(event) - 2u; 181 little_endian_store_16(event, pos, con_handle); 182 pos += 2; 183 little_endian_store_16(event, pos, mtu); 184 185 // also dispatch to GATT Clients 186 att_dispatch_server_mtu_exchanged(con_handle, mtu); 187 188 // dispatch to app level handler and service handlers 189 att_emit_event_to_all(&event[0], sizeof(event)); 190 } 191 192 static void att_emit_can_send_now_event(void * context){ 193 UNUSED(context); 194 if (!att_client_packet_handler) return; 195 196 uint8_t event[] = { ATT_EVENT_CAN_SEND_NOW, 0}; 197 (*att_client_packet_handler)(HCI_EVENT_PACKET, 0, &event[0], sizeof(event)); 198 } 199 200 static void att_emit_connected_event(hci_connection_t * hci_connection){ 201 att_server_t * att_server = &hci_connection->att_server; 202 att_connection_t * att_connection = &hci_connection->att_connection; 203 uint8_t event[11]; 204 int pos = 0; 205 event[pos++] = ATT_EVENT_CONNECTED; 206 event[pos++] = sizeof(event) - 2u; 207 event[pos++] = att_server->peer_addr_type; 208 reverse_bd_addr(att_server->peer_address, &event[pos]); 209 pos += 6; 210 little_endian_store_16(event, pos, att_connection->con_handle); 211 pos += 2; 212 213 // dispatch to app level handler and service handlers 214 att_emit_event_to_all(&event[0], sizeof(event)); 215 } 216 217 218 static void att_emit_disconnected_event(uint16_t con_handle){ 219 uint8_t event[4]; 220 int pos = 0; 221 event[pos++] = ATT_EVENT_DISCONNECTED; 222 event[pos++] = sizeof(event) - 2u; 223 little_endian_store_16(event, pos, con_handle); 224 pos += 2; 225 226 // dispatch to app level handler and service handlers 227 att_emit_event_to_all(&event[0], sizeof(event)); 228 } 229 230 static void att_handle_value_indication_timeout(btstack_timer_source_t *ts){ 231 void * context = btstack_run_loop_get_timer_context(ts); 232 hci_con_handle_t con_handle = (hci_con_handle_t) (uintptr_t) context; 233 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 234 if (!hci_connection) return; 235 // @note: after a transaction timeout, no more requests shall be sent over this ATT Bearer 236 // (that's why we don't reset the value_indication_handle) 237 att_server_t * att_server = &hci_connection->att_server; 238 uint16_t att_handle = att_server->value_indication_handle; 239 att_connection_t * att_connection = &hci_connection->att_connection; 240 att_handle_value_indication_notify_client(ATT_HANDLE_VALUE_INDICATION_TIMEOUT, att_connection->con_handle, att_handle); 241 } 242 243 static void att_event_packet_handler (uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 244 245 UNUSED(channel); // ok: there is no channel 246 UNUSED(size); // ok: handling own l2cap events 247 248 att_server_t * att_server; 249 att_connection_t * att_connection; 250 hci_con_handle_t con_handle; 251 hci_connection_t * hci_connection; 252 #ifdef ENABLE_GATT_OVER_CLASSIC 253 bd_addr_t address; 254 btstack_linked_list_iterator_t it; 255 #endif 256 257 switch (packet_type) { 258 259 case HCI_EVENT_PACKET: 260 switch (hci_event_packet_get_type(packet)) { 261 262 #ifdef ENABLE_GATT_OVER_CLASSIC 263 case L2CAP_EVENT_INCOMING_CONNECTION: 264 l2cap_event_incoming_connection_get_address(packet, address); 265 l2cap_accept_connection(channel); 266 log_info("Accept incoming connection from %s", bd_addr_to_str(address)); 267 break; 268 case L2CAP_EVENT_CHANNEL_OPENED: 269 con_handle = l2cap_event_channel_opened_get_handle(packet); 270 hci_connection = hci_connection_for_handle(con_handle); 271 if (!hci_connection) break; 272 att_server = &hci_connection->att_server; 273 // store connection info 274 att_server->peer_addr_type = BD_ADDR_TYPE_ACL; 275 l2cap_event_channel_opened_get_address(packet, att_server->peer_address); 276 att_connection = &hci_connection->att_connection; 277 att_connection->con_handle = con_handle; 278 att_server->l2cap_cid = l2cap_event_channel_opened_get_local_cid(packet); 279 // reset connection properties 280 att_server->state = ATT_SERVER_IDLE; 281 att_connection->mtu = l2cap_event_channel_opened_get_remote_mtu(packet); 282 att_connection->max_mtu = l2cap_max_mtu(); 283 if (att_connection->max_mtu > ATT_REQUEST_BUFFER_SIZE){ 284 att_connection->max_mtu = ATT_REQUEST_BUFFER_SIZE; 285 } 286 287 log_info("Connection opened %s, l2cap cid %04x, mtu %u", bd_addr_to_str(address), att_server->l2cap_cid, att_connection->mtu); 288 289 // update security params 290 att_connection->encryption_key_size = gap_encryption_key_size(con_handle); 291 att_connection->authenticated = gap_authenticated(con_handle); 292 att_connection->secure_connection = gap_secure_connection(con_handle); 293 log_info("encrypted key size %u, authenticated %u, secure connection %u", 294 att_connection->encryption_key_size, att_connection->authenticated, att_connection->secure_connection); 295 296 // notify connection opened 297 att_emit_connected_event(hci_connection); 298 299 // restore persisten ccc if encrypted 300 if ( gap_security_level(con_handle) >= LEVEL_2){ 301 att_server_persistent_ccc_restore(hci_connection); 302 } 303 // TODO: what to do about le device db? 304 att_server->pairing_active = 0; 305 break; 306 case L2CAP_EVENT_CAN_SEND_NOW: 307 att_server_handle_can_send_now(); 308 break; 309 310 #endif 311 case HCI_EVENT_LE_META: 312 switch (packet[2]) { 313 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 314 con_handle = little_endian_read_16(packet, 4); 315 hci_connection = hci_connection_for_handle(con_handle); 316 if (!hci_connection) break; 317 att_server = &hci_connection->att_server; 318 // store connection info 319 att_server->peer_addr_type = packet[7]; 320 reverse_bd_addr(&packet[8], att_server->peer_address); 321 att_connection = &hci_connection->att_connection; 322 att_connection->con_handle = con_handle; 323 // reset connection properties 324 att_server->state = ATT_SERVER_IDLE; 325 att_connection->mtu = ATT_DEFAULT_MTU; 326 att_connection->max_mtu = l2cap_max_le_mtu(); 327 if (att_connection->max_mtu > ATT_REQUEST_BUFFER_SIZE){ 328 att_connection->max_mtu = ATT_REQUEST_BUFFER_SIZE; 329 } 330 att_connection->encryption_key_size = 0; 331 att_connection->authenticated = 0; 332 att_connection->authorized = 0; 333 // workaround: identity resolving can already be complete, at least store result 334 att_server->ir_le_device_db_index = sm_le_device_index(con_handle); 335 att_server->ir_lookup_active = 0; 336 att_server->pairing_active = 0; 337 // notify all - old 338 att_emit_event_to_all(packet, size); 339 // notify all - new 340 att_emit_connected_event(hci_connection); 341 break; 342 343 default: 344 break; 345 } 346 break; 347 348 case HCI_EVENT_ENCRYPTION_CHANGE: 349 case HCI_EVENT_ENCRYPTION_KEY_REFRESH_COMPLETE: 350 // check handle 351 con_handle = little_endian_read_16(packet, 3); 352 hci_connection = hci_connection_for_handle(con_handle); 353 if (!hci_connection) break; 354 if (gap_get_connection_type(con_handle) != GAP_CONNECTION_LE) break; 355 // update security params 356 att_server = &hci_connection->att_server; 357 att_connection = &hci_connection->att_connection; 358 att_connection->encryption_key_size = gap_encryption_key_size(con_handle); 359 att_connection->authenticated = gap_authenticated(con_handle); 360 att_connection->secure_connection = gap_secure_connection(con_handle); 361 log_info("encrypted key size %u, authenticated %u, secure connection %u", 362 att_connection->encryption_key_size, att_connection->authenticated, att_connection->secure_connection); 363 if (hci_event_packet_get_type(packet) == HCI_EVENT_ENCRYPTION_CHANGE){ 364 // restore CCC values when encrypted for LE Connections 365 if (hci_event_encryption_change_get_encryption_enabled(packet)){ 366 att_server_persistent_ccc_restore(hci_connection); 367 } 368 } 369 att_run_for_context(hci_connection); 370 break; 371 372 case HCI_EVENT_DISCONNECTION_COMPLETE: 373 // check handle 374 con_handle = hci_event_disconnection_complete_get_connection_handle(packet); 375 hci_connection = hci_connection_for_handle(con_handle); 376 if (!hci_connection) break; 377 att_server = &hci_connection->att_server; 378 att_connection = &hci_connection->att_connection; 379 att_clear_transaction_queue(att_connection); 380 att_connection->con_handle = 0; 381 att_server->pairing_active = 0; 382 att_server->state = ATT_SERVER_IDLE; 383 if (att_server->value_indication_handle){ 384 btstack_run_loop_remove_timer(&att_server->value_indication_timer); 385 uint16_t att_handle = att_server->value_indication_handle; 386 att_server->value_indication_handle = 0; // reset error state 387 att_handle_value_indication_notify_client(ATT_HANDLE_VALUE_INDICATION_DISCONNECT, att_connection->con_handle, att_handle); 388 } 389 // notify all - new 390 att_emit_disconnected_event(con_handle); 391 // notify all - old 392 att_emit_event_to_all(packet, size); 393 break; 394 395 // Identity Resolving 396 case SM_EVENT_IDENTITY_RESOLVING_STARTED: 397 con_handle = sm_event_identity_resolving_started_get_handle(packet); 398 hci_connection = hci_connection_for_handle(con_handle); 399 if (!hci_connection) break; 400 att_server = &hci_connection->att_server; 401 log_info("SM_EVENT_IDENTITY_RESOLVING_STARTED"); 402 att_server->ir_lookup_active = 1; 403 break; 404 case SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED: 405 con_handle = sm_event_identity_created_get_handle(packet); 406 hci_connection = hci_connection_for_handle(con_handle); 407 if (!hci_connection) return; 408 att_server = &hci_connection->att_server; 409 att_server->ir_lookup_active = 0; 410 att_server->ir_le_device_db_index = sm_event_identity_resolving_succeeded_get_index(packet); 411 log_info("SM_EVENT_IDENTITY_RESOLVING_SUCCEEDED"); 412 att_run_for_context(hci_connection); 413 break; 414 case SM_EVENT_IDENTITY_RESOLVING_FAILED: 415 con_handle = sm_event_identity_resolving_failed_get_handle(packet); 416 hci_connection = hci_connection_for_handle(con_handle); 417 if (!hci_connection) break; 418 att_server = &hci_connection->att_server; 419 log_info("SM_EVENT_IDENTITY_RESOLVING_FAILED"); 420 att_server->ir_lookup_active = 0; 421 att_server->ir_le_device_db_index = -1; 422 att_run_for_context(hci_connection); 423 break; 424 425 // Pairing started - delete stored CCC values 426 // - assumes pairing indicates either new device or re-pairing, in both cases there should be no stored CCC values 427 // - assumes that all events have the con handle as the first field 428 case SM_EVENT_JUST_WORKS_REQUEST: 429 case SM_EVENT_PASSKEY_DISPLAY_NUMBER: 430 case SM_EVENT_PASSKEY_INPUT_NUMBER: 431 case SM_EVENT_NUMERIC_COMPARISON_REQUEST: 432 con_handle = sm_event_just_works_request_get_handle(packet); 433 hci_connection = hci_connection_for_handle(con_handle); 434 if (!hci_connection) break; 435 att_server = &hci_connection->att_server; 436 att_server->pairing_active = 1; 437 log_info("SM Pairing started"); 438 if (att_server->ir_le_device_db_index < 0) break; 439 att_server_persistent_ccc_clear(hci_connection); 440 // index not valid anymore 441 att_server->ir_le_device_db_index = -1; 442 break; 443 444 // Bonding completed 445 case SM_EVENT_IDENTITY_CREATED: 446 con_handle = sm_event_identity_created_get_handle(packet); 447 hci_connection = hci_connection_for_handle(con_handle); 448 if (!hci_connection) return; 449 att_server = &hci_connection->att_server; 450 att_server->pairing_active = 0; 451 att_server->ir_le_device_db_index = sm_event_identity_created_get_index(packet); 452 att_run_for_context(hci_connection); 453 break; 454 455 // Pairing complete (with/without bonding=storing of pairing information) 456 case SM_EVENT_PAIRING_COMPLETE: 457 con_handle = sm_event_pairing_complete_get_handle(packet); 458 hci_connection = hci_connection_for_handle(con_handle); 459 if (!hci_connection) return; 460 att_server = &hci_connection->att_server; 461 att_server->pairing_active = 0; 462 att_run_for_context(hci_connection); 463 break; 464 465 // Authorization 466 case SM_EVENT_AUTHORIZATION_RESULT: { 467 con_handle = sm_event_authorization_result_get_handle(packet); 468 hci_connection = hci_connection_for_handle(con_handle); 469 if (!hci_connection) break; 470 att_server = &hci_connection->att_server; 471 att_connection = &hci_connection->att_connection; 472 att_connection->authorized = sm_event_authorization_result_get_authorization_result(packet); 473 att_server_request_can_send_now(hci_connection); 474 break; 475 } 476 default: 477 break; 478 } 479 break; 480 #ifdef ENABLE_GATT_OVER_CLASSIC 481 case L2CAP_DATA_PACKET: 482 hci_connections_get_iterator(&it); 483 while(btstack_linked_list_iterator_has_next(&it)){ 484 hci_connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 485 att_server = &hci_connection->att_server; 486 if (att_server->l2cap_cid == channel) { 487 att_server_handle_att_pdu(hci_connection, packet, size); 488 break; 489 } 490 } 491 break; 492 #endif 493 494 default: 495 break; 496 } 497 } 498 499 #ifdef ENABLE_LE_SIGNED_WRITE 500 static void att_signed_write_handle_cmac_result(uint8_t hash[8]){ 501 502 hci_connection_t * hci_connection = hci_connection_for_state(ATT_SERVER_W4_SIGNED_WRITE_VALIDATION); 503 if (!hci_connection) return; 504 att_server_t * att_server = &hci_connection->att_server; 505 506 uint8_t hash_flipped[8]; 507 reverse_64(hash, hash_flipped); 508 if (memcmp(hash_flipped, &att_server->request_buffer[att_server->request_size-8], 8)){ 509 log_info("ATT Signed Write, invalid signature"); 510 att_server->state = ATT_SERVER_IDLE; 511 return; 512 } 513 log_info("ATT Signed Write, valid signature"); 514 515 // update sequence number 516 uint32_t counter_packet = little_endian_read_32(att_server->request_buffer, att_server->request_size-12); 517 le_device_db_remote_counter_set(att_server->ir_le_device_db_index, counter_packet+1); 518 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 519 att_server_request_can_send_now(hci_connection); 520 } 521 #endif 522 523 // pre: att_server->state == ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED 524 // pre: can send now 525 // returns: 1 if packet was sent 526 static int att_server_process_validated_request(hci_connection_t * hci_connection){ 527 att_server_t * att_server = & hci_connection->att_server; 528 att_connection_t * att_connection = &hci_connection->att_connection; 529 530 l2cap_reserve_packet_buffer(); 531 uint8_t * att_response_buffer = l2cap_get_outgoing_buffer(); 532 uint16_t att_response_size = att_handle_request(att_connection, att_server->request_buffer, att_server->request_size, att_response_buffer); 533 534 #ifdef ENABLE_ATT_DELAYED_RESPONSE 535 if ((att_response_size == ATT_READ_RESPONSE_PENDING) || (att_response_size == ATT_INTERNAL_WRITE_RESPONSE_PENDING)){ 536 // update state 537 att_server->state = ATT_SERVER_RESPONSE_PENDING; 538 539 // callback with handle ATT_READ_RESPONSE_PENDING for reads 540 if (att_response_size == ATT_READ_RESPONSE_PENDING){ 541 att_server_client_read_callback(att_connection->con_handle, ATT_READ_RESPONSE_PENDING, 0, NULL, 0); 542 } 543 544 // free reserved buffer 545 l2cap_release_packet_buffer(); 546 return 0; 547 } 548 #endif 549 550 // intercept "insufficient authorization" for authenticated connections to allow for user authorization 551 if ((att_response_size >= 4u) 552 && (att_response_buffer[0] == ATT_ERROR_RESPONSE) 553 && (att_response_buffer[4] == ATT_ERROR_INSUFFICIENT_AUTHORIZATION) 554 && (att_connection->authenticated)){ 555 556 switch (gap_authorization_state(att_connection->con_handle)){ 557 case AUTHORIZATION_UNKNOWN: 558 l2cap_release_packet_buffer(); 559 sm_request_pairing(att_connection->con_handle); 560 return 0; 561 case AUTHORIZATION_PENDING: 562 l2cap_release_packet_buffer(); 563 return 0; 564 default: 565 break; 566 } 567 } 568 569 att_server->state = ATT_SERVER_IDLE; 570 if (att_response_size == 0u) { 571 l2cap_release_packet_buffer(); 572 return 0; 573 } 574 575 #ifdef ENABLE_GATT_OVER_CLASSIC 576 if (att_server->l2cap_cid != 0){ 577 l2cap_send_prepared(att_server->l2cap_cid, att_response_size); 578 } else 579 #endif 580 { 581 l2cap_send_prepared_connectionless(att_connection->con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, att_response_size); 582 } 583 584 // notify client about MTU exchange result 585 if (att_response_buffer[0] == ATT_EXCHANGE_MTU_RESPONSE){ 586 att_emit_mtu_event(att_connection->con_handle, att_connection->mtu); 587 } 588 return 1; 589 } 590 591 #ifdef ENABLE_ATT_DELAYED_RESPONSE 592 int att_server_response_ready(hci_con_handle_t con_handle){ 593 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 594 if (!hci_connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 595 att_server_t * att_server = &hci_connection->att_server; 596 597 if (att_server->state != ATT_SERVER_RESPONSE_PENDING) return ERROR_CODE_COMMAND_DISALLOWED; 598 599 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 600 att_server_request_can_send_now(hci_connection); 601 return ERROR_CODE_SUCCESS; 602 } 603 #endif 604 605 static void att_run_for_context(hci_connection_t * hci_connection){ 606 att_server_t * att_server = &hci_connection->att_server; 607 att_connection_t * att_connection = &hci_connection->att_connection; 608 switch (att_server->state){ 609 case ATT_SERVER_REQUEST_RECEIVED: 610 611 #ifdef ENABLE_GATT_OVER_CLASSIC 612 if (att_server->l2cap_cid != 0){ 613 // ok 614 } else 615 #endif 616 { 617 // wait until re-encryption as central is complete 618 if (gap_reconnect_security_setup_active(att_connection->con_handle)) break; 619 } 620 621 // wait until pairing is complete 622 if (att_server->pairing_active) break; 623 624 #ifdef ENABLE_LE_SIGNED_WRITE 625 if (att_server->request_buffer[0] == ATT_SIGNED_WRITE_COMMAND){ 626 log_info("ATT Signed Write!"); 627 if (!sm_cmac_ready()) { 628 log_info("ATT Signed Write, sm_cmac engine not ready. Abort"); 629 att_server->state = ATT_SERVER_IDLE; 630 return; 631 } 632 if (att_server->request_size < (3 + 12)) { 633 log_info("ATT Signed Write, request to short. Abort."); 634 att_server->state = ATT_SERVER_IDLE; 635 return; 636 } 637 if (att_server->ir_lookup_active){ 638 return; 639 } 640 if (att_server->ir_le_device_db_index < 0){ 641 log_info("ATT Signed Write, CSRK not available"); 642 att_server->state = ATT_SERVER_IDLE; 643 return; 644 } 645 646 // check counter 647 uint32_t counter_packet = little_endian_read_32(att_server->request_buffer, att_server->request_size-12); 648 uint32_t counter_db = le_device_db_remote_counter_get(att_server->ir_le_device_db_index); 649 log_info("ATT Signed Write, DB counter %"PRIu32", packet counter %"PRIu32, counter_db, counter_packet); 650 if (counter_packet < counter_db){ 651 log_info("ATT Signed Write, db reports higher counter, abort"); 652 att_server->state = ATT_SERVER_IDLE; 653 return; 654 } 655 656 // signature is { sequence counter, secure hash } 657 sm_key_t csrk; 658 le_device_db_remote_csrk_get(att_server->ir_le_device_db_index, csrk); 659 att_server->state = ATT_SERVER_W4_SIGNED_WRITE_VALIDATION; 660 log_info("Orig Signature: "); 661 log_info_hexdump( &att_server->request_buffer[att_server->request_size-8], 8); 662 uint16_t attribute_handle = little_endian_read_16(att_server->request_buffer, 1); 663 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); 664 return; 665 } 666 #endif 667 // move on 668 att_server->state = ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 669 att_server_request_can_send_now(hci_connection); 670 break; 671 672 default: 673 break; 674 } 675 } 676 677 static bool att_server_data_ready_for_phase(att_server_t * att_server, att_server_run_phase_t phase){ 678 switch (phase){ 679 case ATT_SERVER_RUN_PHASE_1_REQUESTS: 680 return att_server->state == ATT_SERVER_REQUEST_RECEIVED_AND_VALIDATED; 681 case ATT_SERVER_RUN_PHASE_2_INDICATIONS: 682 return (!btstack_linked_list_empty(&att_server->indication_requests) && (att_server->value_indication_handle == 0)); 683 case ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS: 684 return (!btstack_linked_list_empty(&att_server->notification_requests)); 685 default: 686 btstack_assert(false); 687 return false; 688 } 689 } 690 691 static void att_server_trigger_send_for_phase(hci_connection_t * hci_connection, att_server_run_phase_t phase){ 692 btstack_context_callback_registration_t * client; 693 att_server_t * att_server = &hci_connection->att_server; 694 switch (phase){ 695 case ATT_SERVER_RUN_PHASE_1_REQUESTS: 696 att_server_process_validated_request(hci_connection); 697 break; 698 case ATT_SERVER_RUN_PHASE_2_INDICATIONS: 699 client = (btstack_context_callback_registration_t*) att_server->indication_requests; 700 btstack_linked_list_remove(&att_server->indication_requests, (btstack_linked_item_t *) client); 701 client->callback(client->context); 702 break; 703 case ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS: 704 client = (btstack_context_callback_registration_t*) att_server->notification_requests; 705 btstack_linked_list_remove(&att_server->notification_requests, (btstack_linked_item_t *) client); 706 client->callback(client->context); 707 break; 708 default: 709 btstack_assert(false); 710 break; 711 } 712 } 713 714 static void att_server_handle_can_send_now(void){ 715 716 hci_con_handle_t last_send_con_handle = HCI_CON_HANDLE_INVALID; 717 hci_connection_t * request_hci_connection = NULL; 718 bool can_send_now = true; 719 int phase_index; 720 721 for (phase_index = ATT_SERVER_RUN_PHASE_1_REQUESTS; phase_index <= ATT_SERVER_RUN_PHASE_3_NOTIFICATIONS; phase_index++){ 722 att_server_run_phase_t phase = (att_server_run_phase_t) phase_index; 723 hci_con_handle_t skip_connections_until = att_server_last_can_send_now; 724 while (true){ 725 btstack_linked_list_iterator_t it; 726 hci_connections_get_iterator(&it); 727 while(btstack_linked_list_iterator_has_next(&it)){ 728 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 729 att_server_t * att_server = &connection->att_server; 730 att_connection_t * att_connection = &connection->att_connection; 731 732 bool data_ready = att_server_data_ready_for_phase(att_server, phase); 733 734 // log_debug("phase %u, handle 0x%04x, skip until 0x%04x, data ready %u", phase, att_connection->con_handle, skip_connections_until, data_ready); 735 736 // skip until last sender found (which is also skipped) 737 if (skip_connections_until != HCI_CON_HANDLE_INVALID){ 738 if (data_ready && (request_hci_connection == NULL)){ 739 request_hci_connection = connection; 740 } 741 if (skip_connections_until == att_connection->con_handle){ 742 skip_connections_until = HCI_CON_HANDLE_INVALID; 743 } 744 continue; 745 }; 746 747 if (data_ready){ 748 if (can_send_now){ 749 att_server_trigger_send_for_phase(connection, phase); 750 last_send_con_handle = att_connection->con_handle; 751 can_send_now = att_server_can_send_packet(connection); 752 data_ready = att_server_data_ready_for_phase(att_server, phase); 753 if (data_ready && (request_hci_connection == NULL)){ 754 request_hci_connection = connection; 755 } 756 } else { 757 request_hci_connection = connection; 758 break; 759 } 760 } 761 } 762 763 // stop skipping (handles disconnect by last send connection) 764 skip_connections_until = HCI_CON_HANDLE_INVALID; 765 766 // Exit loop, if we cannot send 767 if (!can_send_now) break; 768 769 // Exit loop, if we can send but there are also no further request 770 if (request_hci_connection == NULL) break; 771 772 // Finally, if we still can send and there are requests, just try again 773 request_hci_connection = NULL; 774 } 775 // update last send con handle for round robin 776 if (last_send_con_handle != HCI_CON_HANDLE_INVALID){ 777 att_server_last_can_send_now = last_send_con_handle; 778 } 779 } 780 781 if (request_hci_connection == NULL) return; 782 att_server_request_can_send_now(request_hci_connection); 783 } 784 785 static void att_server_handle_att_pdu(hci_connection_t * hci_connection, uint8_t * packet, uint16_t size){ 786 att_server_t * att_server = &hci_connection->att_server; 787 att_connection_t * att_connection = &hci_connection->att_connection; 788 789 uint8_t opcode = packet[0u]; 790 uint8_t method = opcode & 0x03f; 791 bool invalid = method > ATT_MULTIPLE_HANDLE_VALUE_NTF; 792 bool command = (opcode & 0x40) != 0; 793 794 // ignore invalid commands 795 if (invalid && command){ 796 return; 797 } 798 799 // handle value indication confirms 800 if ((opcode == ATT_HANDLE_VALUE_CONFIRMATION) && att_server->value_indication_handle){ 801 btstack_run_loop_remove_timer(&att_server->value_indication_timer); 802 uint16_t att_handle = att_server->value_indication_handle; 803 att_server->value_indication_handle = 0; 804 att_handle_value_indication_notify_client(0, att_connection->con_handle, att_handle); 805 att_server_request_can_send_now(hci_connection); 806 return; 807 } 808 809 // directly process command 810 // note: signed write cannot be handled directly as authentication needs to be verified 811 if (opcode == ATT_WRITE_COMMAND){ 812 att_handle_request(att_connection, packet, size, NULL); 813 return; 814 } 815 816 // check size 817 if (size > sizeof(att_server->request_buffer)) { 818 log_info("drop att pdu 0x%02x as size %u > att_server->request_buffer %u", packet[0], size, (int) sizeof(att_server->request_buffer)); 819 return; 820 } 821 822 #ifdef ENABLE_LE_SIGNED_WRITE 823 // abort signed write validation if a new request comes in (but finish previous signed write if possible) 824 if (att_server->state == ATT_SERVER_W4_SIGNED_WRITE_VALIDATION){ 825 if (packet[0] == ATT_SIGNED_WRITE_COMMAND){ 826 log_info("skip new signed write request as previous is in validation"); 827 return; 828 } else { 829 log_info("abort signed write validation to process new request"); 830 att_server->state = ATT_SERVER_IDLE; 831 } 832 } 833 #endif 834 // last request still in processing? 835 if (att_server->state != ATT_SERVER_IDLE){ 836 log_info("skip att pdu 0x%02x as server not idle (state %u)", packet[0], att_server->state); 837 return; 838 } 839 840 // store request 841 att_server->state = ATT_SERVER_REQUEST_RECEIVED; 842 att_server->request_size = size; 843 (void)memcpy(att_server->request_buffer, packet, size); 844 845 att_run_for_context(hci_connection); 846 } 847 848 static void att_packet_handler(uint8_t packet_type, uint16_t handle, uint8_t *packet, uint16_t size){ 849 hci_connection_t * hci_connection; 850 att_connection_t * att_connection; 851 852 switch (packet_type){ 853 case HCI_EVENT_PACKET: 854 switch (packet[0]){ 855 case L2CAP_EVENT_CAN_SEND_NOW: 856 att_server_handle_can_send_now(); 857 break; 858 case ATT_EVENT_MTU_EXCHANGE_COMPLETE: 859 // GATT client has negotiated the mtu for this connection 860 hci_connection = hci_connection_for_handle(handle); 861 if (!hci_connection) break; 862 att_connection = &hci_connection->att_connection; 863 att_connection->mtu = little_endian_read_16(packet, 4); 864 break; 865 default: 866 break; 867 } 868 break; 869 870 case ATT_DATA_PACKET: 871 log_debug("ATT Packet, handle 0x%04x", handle); 872 hci_connection = hci_connection_for_handle(handle); 873 if (!hci_connection) break; 874 875 att_server_handle_att_pdu(hci_connection, packet, size); 876 break; 877 878 default: 879 break; 880 } 881 } 882 883 // --------------------- 884 // persistent CCC writes 885 static uint32_t att_server_persistent_ccc_tag_for_index(uint8_t index){ 886 return ('B' << 24u) | ('T' << 16u) | ('C' << 8u) | index; 887 } 888 889 static void att_server_persistent_ccc_write(hci_con_handle_t con_handle, uint16_t att_handle, uint16_t value){ 890 // lookup att_server instance 891 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 892 if (!hci_connection) return; 893 att_server_t * att_server = &hci_connection->att_server; 894 int le_device_index = att_server->ir_le_device_db_index; 895 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); 896 897 // check if bonded 898 if (le_device_index < 0) return; 899 900 // get btstack_tlv 901 const btstack_tlv_t * tlv_impl = NULL; 902 void * tlv_context; 903 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 904 if (!tlv_impl) return; 905 906 // update ccc tag 907 int index; 908 uint32_t highest_seq_nr = 0; 909 uint32_t lowest_seq_nr = 0; 910 uint32_t tag_for_lowest_seq_nr = 0; 911 uint32_t tag_for_empty = 0; 912 persistent_ccc_entry_t entry; 913 for (index=0;index<NVN_NUM_GATT_SERVER_CCC;index++){ 914 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 915 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 916 917 // empty/invalid tag 918 if (len != sizeof(persistent_ccc_entry_t)){ 919 tag_for_empty = tag; 920 continue; 921 } 922 // update highest seq nr 923 if (entry.seq_nr > highest_seq_nr){ 924 highest_seq_nr = entry.seq_nr; 925 } 926 // find entry with lowest seq nr 927 if ((tag_for_lowest_seq_nr == 0u) || (entry.seq_nr < lowest_seq_nr)){ 928 tag_for_lowest_seq_nr = tag; 929 lowest_seq_nr = entry.seq_nr; 930 } 931 932 if (entry.device_index != le_device_index) continue; 933 if (entry.att_handle != att_handle) continue; 934 935 // found matching entry 936 if (value != 0){ 937 // update 938 if (entry.value == value) { 939 log_info("CCC Index %u: Up-to-date", index); 940 return; 941 } 942 entry.value = value; 943 entry.seq_nr = highest_seq_nr + 1u; 944 log_info("CCC Index %u: Store", index); 945 int result = tlv_impl->store_tag(tlv_context, tag, (const uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 946 if (result != 0){ 947 log_error("Store tag index %u failed", index); 948 } 949 } else { 950 // delete 951 log_info("CCC Index %u: Delete", index); 952 tlv_impl->delete_tag(tlv_context, tag); 953 } 954 return; 955 } 956 957 log_info("tag_for_empty %"PRIx32", tag_for_lowest_seq_nr %"PRIx32, tag_for_empty, tag_for_lowest_seq_nr); 958 959 if (value == 0u){ 960 // done 961 return; 962 } 963 964 uint32_t tag_to_use = 0; 965 if (tag_for_empty != 0){ 966 tag_to_use = tag_for_empty; 967 } else if (tag_for_lowest_seq_nr){ 968 tag_to_use = tag_for_lowest_seq_nr; 969 } else { 970 // should not happen 971 return; 972 } 973 // store ccc tag 974 entry.seq_nr = highest_seq_nr + 1u; 975 entry.device_index = le_device_index; 976 entry.att_handle = att_handle; 977 entry.value = value; 978 int result = tlv_impl->store_tag(tlv_context, tag_to_use, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 979 if (result != 0){ 980 log_error("Store tag index %u failed", index); 981 } 982 } 983 984 static void att_server_persistent_ccc_clear(hci_connection_t * hci_connection){ 985 if (!hci_connection) return; 986 att_server_t * att_server = &hci_connection->att_server; 987 988 int le_device_index = att_server->ir_le_device_db_index; 989 log_info("Clear CCC values of remote %s, le device id %d", bd_addr_to_str(att_server->peer_address), le_device_index); 990 // check if bonded 991 if (le_device_index < 0) return; 992 // get btstack_tlv 993 const btstack_tlv_t * tlv_impl = NULL; 994 void * tlv_context; 995 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 996 if (!tlv_impl) return; 997 // get all ccc tag 998 int index; 999 persistent_ccc_entry_t entry; 1000 for (index=0;index<NVN_NUM_GATT_SERVER_CCC;index++){ 1001 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 1002 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 1003 if (len != sizeof(persistent_ccc_entry_t)) continue; 1004 if (entry.device_index != le_device_index) continue; 1005 // delete entry 1006 log_info("CCC Index %u: Delete", index); 1007 tlv_impl->delete_tag(tlv_context, tag); 1008 } 1009 } 1010 1011 static void att_server_persistent_ccc_restore(hci_connection_t * hci_connection){ 1012 if (!hci_connection) return; 1013 att_server_t * att_server = &hci_connection->att_server; 1014 att_connection_t * att_connection = &hci_connection->att_connection; 1015 1016 int le_device_index = att_server->ir_le_device_db_index; 1017 log_info("Restore CCC values of remote %s, le device id %d", bd_addr_to_str(att_server->peer_address), le_device_index); 1018 // check if bonded 1019 if (le_device_index < 0) return; 1020 // get btstack_tlv 1021 const btstack_tlv_t * tlv_impl = NULL; 1022 void * tlv_context; 1023 btstack_tlv_get_instance(&tlv_impl, &tlv_context); 1024 if (!tlv_impl) return; 1025 // get all ccc tag 1026 int index; 1027 persistent_ccc_entry_t entry; 1028 for (index=0;index<NVN_NUM_GATT_SERVER_CCC;index++){ 1029 uint32_t tag = att_server_persistent_ccc_tag_for_index(index); 1030 int len = tlv_impl->get_tag(tlv_context, tag, (uint8_t *) &entry, sizeof(persistent_ccc_entry_t)); 1031 if (len != sizeof(persistent_ccc_entry_t)) continue; 1032 if (entry.device_index != le_device_index) continue; 1033 // simulate write callback 1034 uint16_t attribute_handle = entry.att_handle; 1035 uint8_t value[2]; 1036 little_endian_store_16(value, 0, entry.value); 1037 att_write_callback_t callback = att_server_write_callback_for_handle(attribute_handle); 1038 if (!callback) continue; 1039 log_info("CCC Index %u: Set Attribute handle 0x%04x to value 0x%04x", index, attribute_handle, entry.value ); 1040 (*callback)(att_connection->con_handle, attribute_handle, ATT_TRANSACTION_MODE_NONE, 0, value, sizeof(value)); 1041 } 1042 } 1043 1044 // persistent CCC writes 1045 // --------------------- 1046 1047 // gatt service management 1048 static att_service_handler_t * att_service_handler_for_handle(uint16_t handle){ 1049 btstack_linked_list_iterator_t it; 1050 btstack_linked_list_iterator_init(&it, &service_handlers); 1051 while (btstack_linked_list_iterator_has_next(&it)){ 1052 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 1053 if (handler->start_handle > handle) continue; 1054 if (handler->end_handle < handle) continue; 1055 return handler; 1056 } 1057 return NULL; 1058 } 1059 static att_read_callback_t att_server_read_callback_for_handle(uint16_t handle){ 1060 att_service_handler_t * handler = att_service_handler_for_handle(handle); 1061 if (handler != NULL) return handler->read_callback; 1062 return att_server_client_read_callback; 1063 } 1064 1065 static att_write_callback_t att_server_write_callback_for_handle(uint16_t handle){ 1066 att_service_handler_t * handler = att_service_handler_for_handle(handle); 1067 if (handler != NULL) return handler->write_callback; 1068 return att_server_client_write_callback; 1069 } 1070 1071 static btstack_packet_handler_t att_server_packet_handler_for_handle(uint16_t handle){ 1072 att_service_handler_t * handler = att_service_handler_for_handle(handle); 1073 if (handler != NULL) return handler->packet_handler; 1074 return att_client_packet_handler; 1075 } 1076 1077 static void att_notify_write_callbacks(hci_con_handle_t con_handle, uint16_t transaction_mode){ 1078 // notify all callbacks 1079 btstack_linked_list_iterator_t it; 1080 btstack_linked_list_iterator_init(&it, &service_handlers); 1081 while (btstack_linked_list_iterator_has_next(&it)){ 1082 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 1083 if (!handler->write_callback) continue; 1084 (*handler->write_callback)(con_handle, 0, transaction_mode, 0, NULL, 0); 1085 } 1086 if (!att_server_client_write_callback) return; 1087 (*att_server_client_write_callback)(con_handle, 0, transaction_mode, 0, NULL, 0); 1088 } 1089 1090 // returns first reported error or 0 1091 static uint8_t att_validate_prepared_write(hci_con_handle_t con_handle){ 1092 btstack_linked_list_iterator_t it; 1093 btstack_linked_list_iterator_init(&it, &service_handlers); 1094 while (btstack_linked_list_iterator_has_next(&it)){ 1095 att_service_handler_t * handler = (att_service_handler_t*) btstack_linked_list_iterator_next(&it); 1096 if (!handler->write_callback) continue; 1097 uint8_t error_code = (*handler->write_callback)(con_handle, 0, ATT_TRANSACTION_MODE_VALIDATE, 0, NULL, 0); 1098 if (error_code != 0) return error_code; 1099 } 1100 if (!att_server_client_write_callback) return 0; 1101 return (*att_server_client_write_callback)(con_handle, 0, ATT_TRANSACTION_MODE_VALIDATE, 0, NULL, 0); 1102 } 1103 1104 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){ 1105 att_read_callback_t callback = att_server_read_callback_for_handle(attribute_handle); 1106 if (!callback) return 0; 1107 return (*callback)(con_handle, attribute_handle, offset, buffer, buffer_size); 1108 } 1109 1110 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){ 1111 switch (transaction_mode){ 1112 case ATT_TRANSACTION_MODE_VALIDATE: 1113 return att_validate_prepared_write(con_handle); 1114 case ATT_TRANSACTION_MODE_EXECUTE: 1115 case ATT_TRANSACTION_MODE_CANCEL: 1116 att_notify_write_callbacks(con_handle, transaction_mode); 1117 return 0; 1118 default: 1119 break; 1120 } 1121 1122 // track CCC writes 1123 if (att_is_persistent_ccc(attribute_handle) && (offset == 0u) && (buffer_size == 2u)){ 1124 att_server_persistent_ccc_write(con_handle, attribute_handle, little_endian_read_16(buffer, 0)); 1125 } 1126 1127 att_write_callback_t callback = att_server_write_callback_for_handle(attribute_handle); 1128 if (!callback) return 0; 1129 return (*callback)(con_handle, attribute_handle, transaction_mode, offset, buffer, buffer_size); 1130 } 1131 1132 /** 1133 * @brief register read/write callbacks for specific handle range 1134 * @param att_service_handler_t 1135 */ 1136 void att_server_register_service_handler(att_service_handler_t * handler){ 1137 if (att_service_handler_for_handle(handler->start_handle) || 1138 att_service_handler_for_handle(handler->end_handle)){ 1139 log_error("handler for range 0x%04x-0x%04x already registered", handler->start_handle, handler->end_handle); 1140 return; 1141 } 1142 btstack_linked_list_add(&service_handlers, (btstack_linked_item_t*) handler); 1143 } 1144 1145 void att_server_init(uint8_t const * db, att_read_callback_t read_callback, att_write_callback_t write_callback){ 1146 1147 // store callbacks 1148 att_server_client_read_callback = read_callback; 1149 att_server_client_write_callback = write_callback; 1150 1151 // register for HCI Events 1152 hci_event_callback_registration.callback = &att_event_packet_handler; 1153 hci_add_event_handler(&hci_event_callback_registration); 1154 1155 // register for SM events 1156 sm_event_callback_registration.callback = &att_event_packet_handler; 1157 sm_add_event_handler(&sm_event_callback_registration); 1158 1159 // and L2CAP ATT Server PDUs 1160 att_dispatch_register_server(att_packet_handler); 1161 1162 #ifdef ENABLE_GATT_OVER_CLASSIC 1163 // setup l2cap service 1164 l2cap_register_service(&att_event_packet_handler, PSM_ATT, 0xffff, gap_get_security_level()); 1165 #endif 1166 1167 att_set_db(db); 1168 att_set_read_callback(att_server_read_callback); 1169 att_set_write_callback(att_server_write_callback); 1170 } 1171 1172 void att_server_register_packet_handler(btstack_packet_handler_t handler){ 1173 att_client_packet_handler = handler; 1174 } 1175 1176 1177 // to be deprecated 1178 int att_server_can_send_packet_now(hci_con_handle_t con_handle){ 1179 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 1180 if (!hci_connection) return 0; 1181 return att_server_can_send_packet(hci_connection); 1182 } 1183 1184 int att_server_register_can_send_now_callback(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 1185 return att_server_request_to_send_notification(callback_registration, con_handle); 1186 } 1187 1188 void att_server_request_can_send_now_event(hci_con_handle_t con_handle){ 1189 att_client_waiting_for_can_send_registration.callback = &att_emit_can_send_now_event; 1190 att_server_request_to_send_notification(&att_client_waiting_for_can_send_registration, con_handle); 1191 } 1192 // end of deprecated 1193 1194 int att_server_request_to_send_notification(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 1195 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 1196 if (!hci_connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1197 att_server_t * att_server = &hci_connection->att_server; 1198 bool added = btstack_linked_list_add_tail(&att_server->notification_requests, (btstack_linked_item_t*) callback_registration); 1199 att_server_request_can_send_now(hci_connection); 1200 if (added){ 1201 return ERROR_CODE_SUCCESS; 1202 } else { 1203 return ERROR_CODE_COMMAND_DISALLOWED; 1204 } 1205 } 1206 1207 int att_server_request_to_send_indication(btstack_context_callback_registration_t * callback_registration, hci_con_handle_t con_handle){ 1208 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 1209 if (!hci_connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1210 att_server_t * att_server = &hci_connection->att_server; 1211 bool added = btstack_linked_list_add_tail(&att_server->indication_requests, (btstack_linked_item_t*) callback_registration); 1212 att_server_request_can_send_now(hci_connection); 1213 if (added){ 1214 return ERROR_CODE_SUCCESS; 1215 } else { 1216 return ERROR_CODE_COMMAND_DISALLOWED; 1217 } 1218 } 1219 1220 int att_server_notify(hci_con_handle_t con_handle, uint16_t attribute_handle, const uint8_t *value, uint16_t value_len){ 1221 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 1222 if (!hci_connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1223 att_connection_t * att_connection = &hci_connection->att_connection; 1224 1225 if (!att_server_can_send_packet(hci_connection)) return BTSTACK_ACL_BUFFERS_FULL; 1226 1227 l2cap_reserve_packet_buffer(); 1228 uint8_t * packet_buffer = l2cap_get_outgoing_buffer(); 1229 uint16_t size = att_prepare_handle_value_notification(att_connection, attribute_handle, value, value_len, packet_buffer); 1230 #ifdef ENABLE_GATT_OVER_CLASSIC 1231 att_server_t * att_server = &hci_connection->att_server; 1232 if (att_server->l2cap_cid != 0){ 1233 return l2cap_send_prepared(att_server->l2cap_cid, size);; 1234 } 1235 #endif 1236 return l2cap_send_prepared_connectionless(att_connection->con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, size); 1237 } 1238 1239 int att_server_indicate(hci_con_handle_t con_handle, uint16_t attribute_handle, const uint8_t *value, uint16_t value_len){ 1240 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 1241 if (!hci_connection) return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 1242 att_server_t * att_server = &hci_connection->att_server; 1243 att_connection_t * att_connection = &hci_connection->att_connection; 1244 1245 if (att_server->value_indication_handle) return ATT_HANDLE_VALUE_INDICATION_IN_PROGRESS; 1246 if (!att_server_can_send_packet(hci_connection)) return BTSTACK_ACL_BUFFERS_FULL; 1247 1248 // track indication 1249 att_server->value_indication_handle = attribute_handle; 1250 btstack_run_loop_set_timer_handler(&att_server->value_indication_timer, att_handle_value_indication_timeout); 1251 btstack_run_loop_set_timer(&att_server->value_indication_timer, ATT_TRANSACTION_TIMEOUT_MS); 1252 btstack_run_loop_add_timer(&att_server->value_indication_timer); 1253 1254 l2cap_reserve_packet_buffer(); 1255 uint8_t * packet_buffer = l2cap_get_outgoing_buffer(); 1256 uint16_t size = att_prepare_handle_value_indication(att_connection, attribute_handle, value, value_len, packet_buffer); 1257 #ifdef ENABLE_GATT_OVER_CLASSIC 1258 if (att_server->l2cap_cid != 0){ 1259 return l2cap_send_prepared(att_server->l2cap_cid, size);; 1260 } 1261 #endif 1262 l2cap_send_prepared_connectionless(att_connection->con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, size); 1263 return 0; 1264 } 1265 1266 uint16_t att_server_get_mtu(hci_con_handle_t con_handle){ 1267 hci_connection_t * hci_connection = hci_connection_for_handle(con_handle); 1268 if (!hci_connection) return 0; 1269 att_connection_t * att_connection = &hci_connection->att_connection; 1270 return att_connection->mtu; 1271 } 1272