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 /* 39 * l2cap.c 40 * 41 * Logical Link Control and Adaption Protocl (L2CAP) 42 * 43 * Created by Matthias Ringwald on 5/16/09. 44 */ 45 46 #include "l2cap.h" 47 #include "hci.h" 48 #include "hci_dump.h" 49 #include "btstack_debug.h" 50 #include "btstack_event.h" 51 #include "btstack_memory.h" 52 53 #include <stdarg.h> 54 #include <string.h> 55 56 #include <stdio.h> 57 58 // nr of buffered acl packets in outgoing queue to get max performance 59 #define NR_BUFFERED_ACL_PACKETS 3 60 61 // used to cache l2cap rejects, echo, and informational requests 62 #define NR_PENDING_SIGNALING_RESPONSES 3 63 64 // offsets for L2CAP SIGNALING COMMANDS 65 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 66 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 67 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 68 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 69 70 // internal table 71 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL 0 72 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL 1 73 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL 2 74 #define L2CAP_FIXED_CHANNEL_TABLE_SIZE (L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL+1) 75 76 // prototypes 77 static void l2cap_finialize_channel_close(l2cap_channel_t *channel); 78 static inline l2cap_service_t * l2cap_get_service(uint16_t psm); 79 static void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status); 80 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel); 81 static void l2cap_emit_channel_closed(l2cap_channel_t *channel); 82 static void l2cap_emit_connection_request(l2cap_channel_t *channel); 83 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); 84 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); 85 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ); 86 static void l2cap_notify_channel_can_send(void); 87 #ifdef ENABLE_BLE 88 static inline l2cap_service_t * l2cap_le_get_service(uint16_t psm); 89 #endif 90 91 typedef struct l2cap_fixed_channel { 92 btstack_packet_handler_t callback; 93 uint8_t waiting_for_can_send_now; 94 } l2cap_fixed_channel_t; 95 96 static btstack_linked_list_t l2cap_channels; 97 static btstack_linked_list_t l2cap_services; 98 static btstack_linked_list_t l2cap_le_channels; 99 static btstack_linked_list_t l2cap_le_services; 100 101 // used to cache l2cap rejects, echo, and informational requests 102 static l2cap_signaling_response_t signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; 103 static int signaling_responses_pending; 104 105 static uint8_t require_security_level2_for_outgoing_sdp; 106 107 static btstack_packet_callback_registration_t hci_event_callback_registration; 108 109 static btstack_packet_handler_t l2cap_event_packet_handler; 110 static l2cap_fixed_channel_t fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_SIZE]; 111 112 static uint16_t l2cap_fixed_channel_table_channel_id_for_index(int index){ 113 switch (index){ 114 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL: 115 return L2CAP_CID_ATTRIBUTE_PROTOCOL; 116 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL: 117 return L2CAP_CID_SECURITY_MANAGER_PROTOCOL; 118 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL: 119 return L2CAP_CID_CONNECTIONLESS_CHANNEL; 120 default: 121 return 0; 122 } 123 } 124 static int l2cap_fixed_channel_table_index_for_channel_id(uint16_t channel_id){ 125 switch (channel_id){ 126 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 127 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL; 128 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 129 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL; 130 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 131 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL; 132 default: 133 return -1; 134 } 135 } 136 137 static int l2cap_fixed_channel_table_index_is_le(int index){ 138 if (index == L2CAP_CID_CONNECTIONLESS_CHANNEL) return 0; 139 return 1; 140 } 141 142 void l2cap_init(void){ 143 signaling_responses_pending = 0; 144 145 l2cap_channels = NULL; 146 l2cap_services = NULL; 147 l2cap_le_services = NULL; 148 l2cap_le_channels = NULL; 149 150 l2cap_event_packet_handler = NULL; 151 memset(fixed_channels, 0, sizeof(fixed_channels)); 152 153 require_security_level2_for_outgoing_sdp = 0; 154 155 // 156 // register callback with HCI 157 // 158 hci_event_callback_registration.callback = &l2cap_hci_event_handler; 159 hci_add_event_handler(&hci_event_callback_registration); 160 161 hci_register_acl_packet_handler(&l2cap_acl_handler); 162 163 gap_connectable_control(0); // no services yet 164 } 165 166 void l2cap_register_packet_handler(void (*handler)(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 167 l2cap_event_packet_handler = handler; 168 } 169 170 static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 171 (* (channel->packet_handler))(type, channel->local_cid, data, size); 172 } 173 174 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 175 log_info("L2CAP_EVENT_CHANNEL_OPENED status 0x%x addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x local_mtu %u, remote_mtu %u, flush_timeout %u", 176 status, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 177 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 178 uint8_t event[23]; 179 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 180 event[1] = sizeof(event) - 2; 181 event[2] = status; 182 reverse_bd_addr(channel->address, &event[3]); 183 little_endian_store_16(event, 9, channel->con_handle); 184 little_endian_store_16(event, 11, channel->psm); 185 little_endian_store_16(event, 13, channel->local_cid); 186 little_endian_store_16(event, 15, channel->remote_cid); 187 little_endian_store_16(event, 17, channel->local_mtu); 188 little_endian_store_16(event, 19, channel->remote_mtu); 189 little_endian_store_16(event, 21, channel->flush_timeout); 190 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 191 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 192 } 193 194 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 195 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 196 uint8_t event[4]; 197 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 198 event[1] = sizeof(event) - 2; 199 little_endian_store_16(event, 2, channel->local_cid); 200 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 201 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 202 } 203 204 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 205 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 206 bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid); 207 uint8_t event[16]; 208 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 209 event[1] = sizeof(event) - 2; 210 reverse_bd_addr(channel->address, &event[2]); 211 little_endian_store_16(event, 8, channel->con_handle); 212 little_endian_store_16(event, 10, channel->psm); 213 little_endian_store_16(event, 12, channel->local_cid); 214 little_endian_store_16(event, 14, channel->remote_cid); 215 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 216 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 217 } 218 219 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel) { 220 log_info("L2CAP_EVENT_CHANNEL_CAN_SEND_NOW local_cid 0x%x", channel); 221 uint8_t event[4]; 222 event[0] = L2CAP_EVENT_CAN_SEND_NOW; 223 event[1] = sizeof(event) - 2; 224 little_endian_store_16(event, 2, channel); 225 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 226 packet_handler(HCI_EVENT_PACKET, channel, event, sizeof(event)); 227 } 228 229 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 230 uint8_t event[6]; 231 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 232 event[1] = 4; 233 little_endian_store_16(event, 2, con_handle); 234 little_endian_store_16(event, 4, result); 235 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 236 if (!l2cap_event_packet_handler) return; 237 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 238 } 239 240 static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 241 btstack_linked_list_iterator_t it; 242 btstack_linked_list_iterator_init(&it, &l2cap_channels); 243 while (btstack_linked_list_iterator_has_next(&it)){ 244 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 245 if ( channel->local_cid == local_cid) { 246 return channel; 247 } 248 } 249 return NULL; 250 } 251 252 #ifdef ENABLE_BLE 253 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 254 btstack_linked_list_iterator_t it; 255 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 256 while (btstack_linked_list_iterator_has_next(&it)){ 257 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 258 if ( channel->local_cid == local_cid) { 259 return channel; 260 } 261 } 262 return NULL; 263 } 264 #endif 265 266 static l2cap_channel_t * l2cap_get_le_channel_for_address_and_addr_type(bd_addr_t address, bd_addr_type_t address_type){ 267 btstack_linked_list_iterator_t it; 268 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 269 while (btstack_linked_list_iterator_has_next(&it)){ 270 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 271 if (channel->address_type != address_type) continue; 272 if (bd_addr_cmp(channel->address, address)) continue; 273 return channel; 274 } 275 return NULL; 276 } 277 278 /// 279 280 void l2cap_request_can_send_now_event(uint16_t local_cid){ 281 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 282 if (!channel) return; 283 channel->waiting_for_can_send_now = 1; 284 l2cap_notify_channel_can_send(); 285 } 286 287 void l2cap_request_can_send_fix_channel_now_event(hci_con_handle_t con_handle, uint16_t channel_id){ 288 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 289 if (index < 0) return; 290 fixed_channels[index].waiting_for_can_send_now = 1; 291 l2cap_notify_channel_can_send(); 292 } 293 294 /// 295 296 int l2cap_can_send_packet_now(uint16_t local_cid){ 297 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 298 if (!channel) return 0; 299 return hci_can_send_acl_packet_now(channel->con_handle); 300 } 301 302 int l2cap_can_send_prepared_packet_now(uint16_t local_cid){ 303 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 304 if (!channel) return 0; 305 return hci_can_send_prepared_acl_packet_now(channel->con_handle); 306 } 307 308 int l2cap_can_send_fixed_channel_packet_now(hci_con_handle_t con_handle, uint16_t channel_id){ 309 return hci_can_send_acl_packet_now(con_handle); 310 } 311 312 /// 313 314 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 315 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 316 if (channel) { 317 return channel->remote_mtu; 318 } 319 return 0; 320 } 321 322 static l2cap_channel_t * l2cap_channel_for_rtx_timer(btstack_timer_source_t * ts){ 323 btstack_linked_list_iterator_t it; 324 btstack_linked_list_iterator_init(&it, &l2cap_channels); 325 while (btstack_linked_list_iterator_has_next(&it)){ 326 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 327 if ( &channel->rtx == ts) { 328 return channel; 329 } 330 } 331 return NULL; 332 } 333 334 static void l2cap_rtx_timeout(btstack_timer_source_t * ts){ 335 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 336 if (!channel) return; 337 338 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 339 340 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 341 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 342 // notify client 343 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 344 345 // discard channel 346 // no need to stop timer here, it is removed from list during timer callback 347 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 348 btstack_memory_l2cap_channel_free(channel); 349 } 350 351 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 352 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 353 btstack_run_loop_remove_timer(&channel->rtx); 354 } 355 356 static void l2cap_start_rtx(l2cap_channel_t * channel){ 357 l2cap_stop_rtx(channel); 358 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 359 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 360 btstack_run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 361 btstack_run_loop_add_timer(&channel->rtx); 362 } 363 364 static void l2cap_start_ertx(l2cap_channel_t * channel){ 365 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 366 l2cap_stop_rtx(channel); 367 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 368 btstack_run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 369 btstack_run_loop_add_timer(&channel->rtx); 370 } 371 372 void l2cap_require_security_level_2_for_outgoing_sdp(void){ 373 require_security_level2_for_outgoing_sdp = 1; 374 } 375 376 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 377 return (psm == PSM_SDP) && (!require_security_level2_for_outgoing_sdp); 378 } 379 380 static int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 381 382 if (!hci_can_send_acl_packet_now(handle)){ 383 log_info("l2cap_send_signaling_packet, cannot send"); 384 return BTSTACK_ACL_BUFFERS_FULL; 385 } 386 387 // log_info("l2cap_send_signaling_packet type %u", cmd); 388 hci_reserve_packet_buffer(); 389 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 390 va_list argptr; 391 va_start(argptr, identifier); 392 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 393 va_end(argptr); 394 // log_info("l2cap_send_signaling_packet con %u!", handle); 395 return hci_send_acl_packet_buffer(len); 396 } 397 398 #ifdef ENABLE_BLE 399 static int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 400 401 if (!hci_can_send_acl_packet_now(handle)){ 402 log_info("l2cap_send_signaling_packet, cannot send"); 403 return BTSTACK_ACL_BUFFERS_FULL; 404 } 405 406 // log_info("l2cap_send_signaling_packet type %u", cmd); 407 hci_reserve_packet_buffer(); 408 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 409 va_list argptr; 410 va_start(argptr, identifier); 411 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 412 va_end(argptr); 413 // log_info("l2cap_send_signaling_packet con %u!", handle); 414 return hci_send_acl_packet_buffer(len); 415 } 416 #endif 417 418 uint8_t *l2cap_get_outgoing_buffer(void){ 419 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 420 } 421 422 int l2cap_reserve_packet_buffer(void){ 423 return hci_reserve_packet_buffer(); 424 } 425 426 void l2cap_release_packet_buffer(void){ 427 hci_release_packet_buffer(); 428 } 429 430 431 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 432 433 if (!hci_is_packet_buffer_reserved()){ 434 log_error("l2cap_send_prepared called without reserving packet first"); 435 return BTSTACK_ACL_BUFFERS_FULL; 436 } 437 438 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 439 if (!channel) { 440 log_error("l2cap_send_prepared no channel for cid 0x%02x", local_cid); 441 return -1; // TODO: define error 442 } 443 444 if (!hci_can_send_prepared_acl_packet_now(channel->con_handle)){ 445 log_info("l2cap_send_prepared cid 0x%02x, cannot send", local_cid); 446 return BTSTACK_ACL_BUFFERS_FULL; 447 } 448 449 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used", local_cid, channel->con_handle); 450 451 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 452 453 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 454 455 // 0 - Connection handle : PB=pb : BC=00 456 little_endian_store_16(acl_buffer, 0, channel->con_handle | (pb << 12) | (0 << 14)); 457 // 2 - ACL length 458 little_endian_store_16(acl_buffer, 2, len + 4); 459 // 4 - L2CAP packet length 460 little_endian_store_16(acl_buffer, 4, len + 0); 461 // 6 - L2CAP channel DEST 462 little_endian_store_16(acl_buffer, 6, channel->remote_cid); 463 // send 464 int err = hci_send_acl_packet_buffer(len+8); 465 466 return err; 467 } 468 469 int l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len){ 470 471 if (!hci_is_packet_buffer_reserved()){ 472 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 473 return BTSTACK_ACL_BUFFERS_FULL; 474 } 475 476 if (!hci_can_send_prepared_acl_packet_now(con_handle)){ 477 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send", con_handle, cid); 478 return BTSTACK_ACL_BUFFERS_FULL; 479 } 480 481 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x", con_handle, cid); 482 483 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 484 485 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 486 487 // 0 - Connection handle : PB=pb : BC=00 488 little_endian_store_16(acl_buffer, 0, con_handle | (pb << 12) | (0 << 14)); 489 // 2 - ACL length 490 little_endian_store_16(acl_buffer, 2, len + 4); 491 // 4 - L2CAP packet length 492 little_endian_store_16(acl_buffer, 4, len + 0); 493 // 6 - L2CAP channel DEST 494 little_endian_store_16(acl_buffer, 6, cid); 495 // send 496 int err = hci_send_acl_packet_buffer(len+8); 497 498 return err; 499 } 500 501 int l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len){ 502 503 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 504 if (!channel) { 505 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 506 return -1; // TODO: define error 507 } 508 509 if (len > channel->remote_mtu){ 510 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 511 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 512 } 513 514 if (!hci_can_send_acl_packet_now(channel->con_handle)){ 515 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 516 return BTSTACK_ACL_BUFFERS_FULL; 517 } 518 519 hci_reserve_packet_buffer(); 520 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 521 522 memcpy(&acl_buffer[8], data, len); 523 524 return l2cap_send_prepared(local_cid, len); 525 } 526 527 int l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len){ 528 529 if (!hci_can_send_acl_packet_now(con_handle)){ 530 log_info("l2cap_send cid 0x%02x, cannot send", cid); 531 return BTSTACK_ACL_BUFFERS_FULL; 532 } 533 534 hci_reserve_packet_buffer(); 535 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 536 537 memcpy(&acl_buffer[8], data, len); 538 539 return l2cap_send_prepared_connectionless(con_handle, cid, len); 540 } 541 542 int l2cap_send_echo_request(hci_con_handle_t con_handle, uint8_t *data, uint16_t len){ 543 return l2cap_send_signaling_packet(con_handle, ECHO_REQUEST, 0x77, len, data); 544 } 545 546 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 547 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 548 } 549 550 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 551 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 552 } 553 554 555 556 // MARK: L2CAP_RUN 557 // process outstanding signaling tasks 558 static void l2cap_run(void){ 559 560 // log_info("l2cap_run: entered"); 561 562 // check pending signaling responses 563 while (signaling_responses_pending){ 564 565 hci_con_handle_t handle = signaling_responses[0].handle; 566 567 if (!hci_can_send_acl_packet_now(handle)) break; 568 569 uint8_t sig_id = signaling_responses[0].sig_id; 570 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 571 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 572 uint8_t response_code = signaling_responses[0].code; 573 574 // remove first item before sending (to avoid sending response mutliple times) 575 signaling_responses_pending--; 576 int i; 577 for (i=0; i < signaling_responses_pending; i++){ 578 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 579 } 580 581 switch (response_code){ 582 case CONNECTION_REQUEST: 583 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 584 // also disconnect if result is 0x0003 - security blocked 585 if (result == 0x0003){ 586 hci_disconnect_security_block(handle); 587 } 588 break; 589 case ECHO_REQUEST: 590 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 591 break; 592 case INFORMATION_REQUEST: 593 switch (infoType){ 594 case 1: { // Connectionless MTU 595 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 596 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 597 break; 598 } 599 case 2: { // Extended Features Supported 600 // extended features request supported, features: fixed channels, unicast connectionless data reception 601 uint32_t features = 0x280; 602 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 603 break; 604 } 605 case 3: { // Fixed Channels Supported 606 uint8_t map[8]; 607 memset(map, 0, 8); 608 map[0] = 0x06; // L2CAP Signaling Channel (0x02) + Connectionless reception (0x04) 609 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 610 break; 611 } 612 default: 613 // all other types are not supported 614 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 615 break; 616 } 617 break; 618 case COMMAND_REJECT: 619 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 620 #ifdef ENABLE_BLE 621 case COMMAND_REJECT_LE: 622 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 623 break; 624 #endif 625 default: 626 // should not happen 627 break; 628 } 629 } 630 631 uint8_t config_options[4]; 632 btstack_linked_list_iterator_t it; 633 btstack_linked_list_iterator_init(&it, &l2cap_channels); 634 while (btstack_linked_list_iterator_has_next(&it)){ 635 636 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 637 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 638 switch (channel->state){ 639 640 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 641 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 642 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 643 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 644 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 645 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 646 } 647 break; 648 649 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 650 if (!hci_can_send_command_packet_now()) break; 651 // send connection request - set state first 652 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 653 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 654 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 655 break; 656 657 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 658 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 659 channel->state = L2CAP_STATE_INVALID; 660 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 661 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 662 l2cap_stop_rtx(channel); 663 btstack_linked_list_iterator_remove(&it); 664 btstack_memory_l2cap_channel_free(channel); 665 break; 666 667 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 668 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 669 channel->state = L2CAP_STATE_CONFIG; 670 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 671 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 672 break; 673 674 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 675 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 676 // success, start l2cap handshake 677 channel->local_sig_id = l2cap_next_sig_id(); 678 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 679 l2cap_send_signaling_packet( channel->con_handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 680 l2cap_start_rtx(channel); 681 break; 682 683 case L2CAP_STATE_CONFIG: 684 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 685 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 686 uint16_t flags = 0; 687 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 688 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 689 flags = 1; 690 } else { 691 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 692 } 693 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 694 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 695 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 696 config_options[0] = 1; // MTU 697 config_options[1] = 2; // len param 698 little_endian_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 699 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 700 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 701 } else { 702 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 703 } 704 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 705 } 706 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 707 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 708 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 709 channel->local_sig_id = l2cap_next_sig_id(); 710 config_options[0] = 1; // MTU 711 config_options[1] = 2; // len param 712 little_endian_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 713 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 714 l2cap_start_rtx(channel); 715 } 716 if (l2cap_channel_ready_for_open(channel)){ 717 channel->state = L2CAP_STATE_OPEN; 718 l2cap_emit_channel_opened(channel, 0); // success 719 } 720 break; 721 722 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 723 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 724 channel->state = L2CAP_STATE_INVALID; 725 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 726 // we don't start an RTX timer for a disconnect - there's no point in closing the channel if the other side doesn't respond :) 727 l2cap_finialize_channel_close(channel); // -- remove from list 728 break; 729 730 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 731 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 732 channel->local_sig_id = l2cap_next_sig_id(); 733 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 734 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 735 break; 736 default: 737 break; 738 } 739 } 740 741 #ifdef ENABLE_BLE 742 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 743 while (btstack_linked_list_iterator_has_next(&it)){ 744 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 745 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 746 switch (channel->state){ 747 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 748 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 749 channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; 750 // le psm, source cid, mtu, mps, initial credits 751 channel->local_sig_id = l2cap_next_sig_id(); 752 l2cap_send_le_signaling_packet( channel->con_handle, LE_CREDIT_BASED_CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid, 23, 23, 1); 753 break; 754 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 755 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 756 // TODO: support larger MPS 757 channel->state = L2CAP_STATE_OPEN; 758 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, channel->remote_cid, channel->local_mtu, 23, channel->credits_incoming, 0); 759 // notify client 760 l2cap_emit_channel_opened(channel, 0); 761 break; 762 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 763 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 764 channel->state = L2CAP_STATE_INVALID; 765 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, channel->remote_cid, 0, 0, 0, channel->reason); 766 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 767 l2cap_stop_rtx(channel); 768 btstack_linked_list_iterator_remove(&it); 769 btstack_memory_l2cap_channel_free(channel); 770 break; 771 default: 772 break; 773 } 774 } 775 776 // send l2cap con paramter update if necessary 777 hci_connections_get_iterator(&it); 778 while(btstack_linked_list_iterator_has_next(&it)){ 779 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 780 if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; 781 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 782 switch (connection->le_con_parameter_update_state){ 783 case CON_PARAMETER_UPDATE_SEND_REQUEST: 784 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 785 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, connection->le_con_param_update_identifier, 786 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 787 break; 788 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 789 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 790 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 791 break; 792 case CON_PARAMETER_UPDATE_DENY: 793 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 794 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 795 break; 796 default: 797 break; 798 } 799 #if 0 800 void l2cap_le_run(void){ 801 for all channels 802 switch(state): 803 804 if outgoing transfer active 805 send next chunk 806 if done, notify app 807 } 808 #endif 809 } 810 #endif 811 812 // log_info("l2cap_run: exit"); 813 } 814 815 uint16_t l2cap_max_mtu(void){ 816 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 817 } 818 819 uint16_t l2cap_max_le_mtu(void){ 820 return l2cap_max_mtu(); 821 } 822 823 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 824 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 825 log_info("l2cap_handle_connection_complete expected state"); 826 // success, start l2cap handshake 827 channel->con_handle = con_handle; 828 // check remote SSP feature first 829 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 830 } 831 } 832 833 #ifdef ENABLE_BLE 834 static void l2cap_handle_le_connection_complete(l2cap_channel_t * channel, uint8_t status, hci_con_handle_t con_handle){ 835 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 836 log_info("l2cap_le_handle_connection_complete expected state"); 837 // TODO: bail if status != 0 838 839 // success, start l2cap handshake 840 channel->con_handle = con_handle; 841 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 842 } 843 } 844 #endif 845 846 847 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 848 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 849 850 // we have been waiting for remote supported features, if both support SSP, 851 log_info("l2cap received remote supported features, sec_level_0_allowed for psm %u = %u", channel->psm, l2cap_security_level_0_allowed_for_PSM(channel->psm)); 852 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 853 // request security level 2 854 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 855 gap_request_security_level(channel->con_handle, LEVEL_2); 856 return; 857 } 858 // fine, go ahead 859 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 860 } 861 862 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 863 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 864 865 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 866 if (!channel) { 867 return NULL; 868 } 869 870 // Init memory (make valgrind happy) 871 memset(channel, 0, sizeof(l2cap_channel_t)); 872 873 // fill in 874 channel->packet_handler = packet_handler; 875 bd_addr_copy(channel->address, address); 876 channel->address_type = address_type; 877 channel->psm = psm; 878 channel->local_mtu = local_mtu; 879 channel->remote_mtu = L2CAP_MINIMAL_MTU; 880 channel->required_security_level = security_level; 881 882 // 883 channel->local_cid = l2cap_next_local_cid(); 884 channel->con_handle = 0; 885 886 // set initial state 887 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 888 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 889 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 890 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 891 return channel; 892 } 893 894 /** 895 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 896 * @param packet_handler 897 * @param address 898 * @param psm 899 * @param mtu 900 * @param local_cid 901 */ 902 903 uint8_t l2cap_create_channel(btstack_packet_handler_t channel_packet_handler, bd_addr_t address, uint16_t psm, uint16_t local_mtu, uint16_t * out_local_cid){ 904 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, local_mtu); 905 906 if (local_mtu > l2cap_max_mtu()) { 907 local_mtu = l2cap_max_mtu(); 908 } 909 910 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 911 if (!channel) { 912 return BTSTACK_MEMORY_ALLOC_FAILED; 913 } 914 915 // add to connections list 916 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 917 918 // store local_cid 919 if (out_local_cid){ 920 *out_local_cid = channel->local_cid; 921 } 922 923 // check if hci connection is already usable 924 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 925 if (conn){ 926 log_info("l2cap_create_channel, hci connection already exists"); 927 l2cap_handle_connection_complete(conn->con_handle, channel); 928 // check if remote supported fearures are already received 929 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 930 l2cap_handle_remote_supported_features_received(channel); 931 } 932 } 933 934 l2cap_run(); 935 936 return 0; 937 } 938 939 void 940 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 941 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 942 // find channel for local_cid 943 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 944 if (channel) { 945 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 946 } 947 // process 948 l2cap_run(); 949 } 950 951 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 952 btstack_linked_list_iterator_t it; 953 btstack_linked_list_iterator_init(&it, &l2cap_channels); 954 while (btstack_linked_list_iterator_has_next(&it)){ 955 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 956 if ( bd_addr_cmp( channel->address, address) != 0) continue; 957 // channel for this address found 958 switch (channel->state){ 959 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 960 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 961 // failure, forward error code 962 l2cap_emit_channel_opened(channel, status); 963 // discard channel 964 l2cap_stop_rtx(channel); 965 btstack_linked_list_iterator_remove(&it); 966 btstack_memory_l2cap_channel_free(channel); 967 break; 968 default: 969 break; 970 } 971 } 972 } 973 974 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 975 btstack_linked_list_iterator_t it; 976 btstack_linked_list_iterator_init(&it, &l2cap_channels); 977 while (btstack_linked_list_iterator_has_next(&it)){ 978 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 979 if ( ! bd_addr_cmp( channel->address, address) ){ 980 l2cap_handle_connection_complete(handle, channel); 981 } 982 } 983 // process 984 l2cap_run(); 985 } 986 987 static void l2cap_notify_channel_can_send(void){ 988 btstack_linked_list_iterator_t it; 989 btstack_linked_list_iterator_init(&it, &l2cap_channels); 990 while (btstack_linked_list_iterator_has_next(&it)){ 991 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 992 if (!channel->waiting_for_can_send_now) continue; 993 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 994 channel->waiting_for_can_send_now = 0; 995 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 996 } 997 998 int i; 999 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1000 if (!fixed_channels[i].callback) continue; 1001 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1002 int can_send; 1003 if (l2cap_fixed_channel_table_index_is_le(i)){ 1004 can_send = hci_can_send_acl_le_packet_now(); 1005 } else { 1006 can_send = hci_can_send_acl_classic_packet_now(); 1007 } 1008 if (!can_send) continue; 1009 fixed_channels[i].waiting_for_can_send_now = 0; 1010 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1011 } 1012 } 1013 1014 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1015 1016 bd_addr_t address; 1017 hci_con_handle_t handle; 1018 btstack_linked_list_iterator_t it; 1019 int hci_con_used; 1020 1021 switch(hci_event_packet_get_type(packet)){ 1022 1023 // handle connection complete events 1024 case HCI_EVENT_CONNECTION_COMPLETE: 1025 reverse_bd_addr(&packet[5], address); 1026 if (packet[2] == 0){ 1027 handle = little_endian_read_16(packet, 3); 1028 l2cap_handle_connection_success_for_addr(address, handle); 1029 } else { 1030 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1031 } 1032 break; 1033 1034 // handle successful create connection cancel command 1035 case HCI_EVENT_COMMAND_COMPLETE: 1036 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1037 if (packet[5] == 0){ 1038 reverse_bd_addr(&packet[6], address); 1039 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1040 l2cap_handle_connection_failed_for_addr(address, 0x16); 1041 } 1042 } 1043 l2cap_run(); // try sending signaling packets first 1044 break; 1045 1046 case HCI_EVENT_COMMAND_STATUS: 1047 l2cap_run(); // try sending signaling packets first 1048 break; 1049 1050 // handle disconnection complete events 1051 case HCI_EVENT_DISCONNECTION_COMPLETE: 1052 // send l2cap disconnect events for all channels on this handle and free them 1053 handle = little_endian_read_16(packet, 3); 1054 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1055 while (btstack_linked_list_iterator_has_next(&it)){ 1056 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1057 if (channel->con_handle != handle) continue; 1058 l2cap_emit_channel_closed(channel); 1059 l2cap_stop_rtx(channel); 1060 btstack_linked_list_iterator_remove(&it); 1061 btstack_memory_l2cap_channel_free(channel); 1062 } 1063 #ifdef ENABLE_BLE 1064 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1065 while (btstack_linked_list_iterator_has_next(&it)){ 1066 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1067 if (channel->con_handle != handle) continue; 1068 l2cap_emit_channel_closed(channel); 1069 btstack_linked_list_iterator_remove(&it); 1070 btstack_memory_l2cap_channel_free(channel); 1071 } 1072 #endif 1073 break; 1074 1075 // Notify channel packet handler if they can send now 1076 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1077 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1078 l2cap_run(); // try sending signaling packets first 1079 l2cap_notify_channel_can_send(); 1080 break; 1081 1082 // HCI Connection Timeouts 1083 case L2CAP_EVENT_TIMEOUT_CHECK: 1084 handle = little_endian_read_16(packet, 2); 1085 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1086 if (hci_authentication_active_for_handle(handle)) break; 1087 hci_con_used = 0; 1088 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1089 while (btstack_linked_list_iterator_has_next(&it)){ 1090 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1091 if (channel->con_handle != handle) continue; 1092 hci_con_used = 1; 1093 break; 1094 } 1095 if (hci_con_used) break; 1096 if (!hci_can_send_command_packet_now()) break; 1097 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1098 break; 1099 1100 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1101 handle = little_endian_read_16(packet, 3); 1102 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1103 while (btstack_linked_list_iterator_has_next(&it)){ 1104 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1105 if (channel->con_handle != handle) continue; 1106 l2cap_handle_remote_supported_features_received(channel); 1107 break; 1108 } 1109 break; 1110 1111 #ifdef ENABLE_BLE 1112 case HCI_EVENT_LE_META: 1113 switch (packet[2]){ 1114 int addr_type; 1115 l2cap_channel_t * channel; 1116 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 1117 // Connection management 1118 reverse_bd_addr(&packet[8], address); 1119 addr_type = (bd_addr_type_t)packet[7]; 1120 log_info("L2CAP - LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(address)); 1121 // get l2cap_channel 1122 // also pass in status 1123 channel = l2cap_get_le_channel_for_address_and_addr_type(address, addr_type); 1124 if (!channel) break; 1125 l2cap_handle_le_connection_complete(channel, packet[3], little_endian_read_16(packet, 4)); 1126 break; 1127 default: 1128 break; 1129 } 1130 break; 1131 #endif 1132 1133 case GAP_EVENT_SECURITY_LEVEL: 1134 handle = little_endian_read_16(packet, 2); 1135 log_info("l2cap - security level update"); 1136 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1137 while (btstack_linked_list_iterator_has_next(&it)){ 1138 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1139 if (channel->con_handle != handle) continue; 1140 1141 log_info("l2cap - state %u", channel->state); 1142 1143 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1144 gap_security_level_t required_level = channel->required_security_level; 1145 1146 switch (channel->state){ 1147 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1148 if (actual_level >= required_level){ 1149 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1150 l2cap_emit_connection_request(channel); 1151 } else { 1152 channel->reason = 0x0003; // security block 1153 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1154 } 1155 break; 1156 1157 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1158 if (actual_level >= required_level){ 1159 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1160 } else { 1161 // disconnnect, authentication not good enough 1162 hci_disconnect_security_block(handle); 1163 } 1164 break; 1165 1166 default: 1167 break; 1168 } 1169 } 1170 break; 1171 1172 default: 1173 break; 1174 } 1175 1176 l2cap_run(); 1177 } 1178 1179 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1180 channel->remote_sig_id = identifier; 1181 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1182 l2cap_run(); 1183 } 1184 1185 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 1186 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1187 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1188 signaling_responses[signaling_responses_pending].handle = handle; 1189 signaling_responses[signaling_responses_pending].code = code; 1190 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1191 signaling_responses[signaling_responses_pending].data = data; 1192 signaling_responses_pending++; 1193 l2cap_run(); 1194 } 1195 } 1196 1197 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1198 1199 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1200 l2cap_service_t *service = l2cap_get_service(psm); 1201 if (!service) { 1202 // 0x0002 PSM not supported 1203 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 1204 return; 1205 } 1206 1207 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1208 if (!hci_connection) { 1209 // 1210 log_error("no hci_connection for handle %u", handle); 1211 return; 1212 } 1213 1214 // alloc structure 1215 // log_info("l2cap_handle_connection_request register channel"); 1216 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 1217 psm, service->mtu, service->required_security_level); 1218 if (!channel){ 1219 // 0x0004 No resources available 1220 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 1221 return; 1222 } 1223 1224 channel->con_handle = handle; 1225 channel->remote_cid = source_cid; 1226 channel->remote_sig_id = sig_id; 1227 1228 // limit local mtu to max acl packet length - l2cap header 1229 if (channel->local_mtu > l2cap_max_mtu()) { 1230 channel->local_mtu = l2cap_max_mtu(); 1231 } 1232 1233 // set initial state 1234 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1235 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 1236 1237 // add to connections list 1238 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1239 1240 // assert security requirements 1241 gap_request_security_level(handle, channel->required_security_level); 1242 } 1243 1244 void l2cap_accept_connection(uint16_t local_cid){ 1245 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1246 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1247 if (!channel) { 1248 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1249 return; 1250 } 1251 1252 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1253 1254 // process 1255 l2cap_run(); 1256 } 1257 1258 void l2cap_decline_connection(uint16_t local_cid){ 1259 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 1260 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1261 if (!channel) { 1262 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1263 return; 1264 } 1265 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1266 channel->reason = 0x04; // no resources available 1267 l2cap_run(); 1268 } 1269 1270 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1271 1272 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1273 1274 uint16_t flags = little_endian_read_16(command, 6); 1275 if (flags & 1) { 1276 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1277 } 1278 1279 // accept the other's configuration options 1280 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1281 uint16_t pos = 8; 1282 while (pos < end_pos){ 1283 uint8_t option_hint = command[pos] >> 7; 1284 uint8_t option_type = command[pos] & 0x7f; 1285 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1286 pos++; 1287 uint8_t length = command[pos++]; 1288 // MTU { type(8): 1, len(8):2, MTU(16) } 1289 if (option_type == 1 && length == 2){ 1290 channel->remote_mtu = little_endian_read_16(command, pos); 1291 // log_info("l2cap cid 0x%02x, remote mtu %u", channel->local_cid, channel->remote_mtu); 1292 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1293 } 1294 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1295 if (option_type == 2 && length == 2){ 1296 channel->flush_timeout = little_endian_read_16(command, pos); 1297 } 1298 // check for unknown options 1299 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1300 log_info("l2cap cid %u, unknown options", channel->local_cid); 1301 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1302 } 1303 pos += length; 1304 } 1305 } 1306 1307 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1308 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1309 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1310 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1311 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 1312 if (channel->state == L2CAP_STATE_OPEN) return 0; 1313 return 1; 1314 } 1315 1316 1317 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1318 1319 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1320 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1321 uint16_t result = 0; 1322 1323 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1324 1325 // handle DISCONNECT REQUESTS seperately 1326 if (code == DISCONNECTION_REQUEST){ 1327 switch (channel->state){ 1328 case L2CAP_STATE_CONFIG: 1329 case L2CAP_STATE_OPEN: 1330 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1331 case L2CAP_STATE_WAIT_DISCONNECT: 1332 l2cap_handle_disconnect_request(channel, identifier); 1333 break; 1334 1335 default: 1336 // ignore in other states 1337 break; 1338 } 1339 return; 1340 } 1341 1342 // @STATEMACHINE(l2cap) 1343 switch (channel->state) { 1344 1345 case L2CAP_STATE_WAIT_CONNECT_RSP: 1346 switch (code){ 1347 case CONNECTION_RESPONSE: 1348 l2cap_stop_rtx(channel); 1349 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1350 switch (result) { 1351 case 0: 1352 // successful connection 1353 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1354 channel->state = L2CAP_STATE_CONFIG; 1355 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1356 break; 1357 case 1: 1358 // connection pending. get some coffee, but start the ERTX 1359 l2cap_start_ertx(channel); 1360 break; 1361 default: 1362 // channel closed 1363 channel->state = L2CAP_STATE_CLOSED; 1364 // map l2cap connection response result to BTstack status enumeration 1365 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1366 1367 // drop link key if security block 1368 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1369 gap_drop_link_key_for_bd_addr(channel->address); 1370 } 1371 1372 // discard channel 1373 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1374 btstack_memory_l2cap_channel_free(channel); 1375 break; 1376 } 1377 break; 1378 1379 default: 1380 //@TODO: implement other signaling packets 1381 break; 1382 } 1383 break; 1384 1385 case L2CAP_STATE_CONFIG: 1386 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1387 switch (code) { 1388 case CONFIGURE_REQUEST: 1389 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1390 l2cap_signaling_handle_configure_request(channel, command); 1391 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1392 // only done if continuation not set 1393 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1394 } 1395 break; 1396 case CONFIGURE_RESPONSE: 1397 l2cap_stop_rtx(channel); 1398 switch (result){ 1399 case 0: // success 1400 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1401 break; 1402 case 4: // pending 1403 l2cap_start_ertx(channel); 1404 break; 1405 default: 1406 // retry on negative result 1407 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1408 break; 1409 } 1410 break; 1411 default: 1412 break; 1413 } 1414 if (l2cap_channel_ready_for_open(channel)){ 1415 // for open: 1416 channel->state = L2CAP_STATE_OPEN; 1417 l2cap_emit_channel_opened(channel, 0); 1418 } 1419 break; 1420 1421 case L2CAP_STATE_WAIT_DISCONNECT: 1422 switch (code) { 1423 case DISCONNECTION_RESPONSE: 1424 l2cap_finialize_channel_close(channel); 1425 break; 1426 default: 1427 //@TODO: implement other signaling packets 1428 break; 1429 } 1430 break; 1431 1432 case L2CAP_STATE_CLOSED: 1433 // @TODO handle incoming requests 1434 break; 1435 1436 case L2CAP_STATE_OPEN: 1437 //@TODO: implement other signaling packets, e.g. re-configure 1438 break; 1439 default: 1440 break; 1441 } 1442 // log_info("new state %u", channel->state); 1443 } 1444 1445 1446 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1447 1448 // get code, signalind identifier and command len 1449 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1450 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1451 1452 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1453 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1454 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1455 return; 1456 } 1457 1458 // general commands without an assigned channel 1459 switch(code) { 1460 1461 case CONNECTION_REQUEST: { 1462 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1463 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1464 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1465 return; 1466 } 1467 1468 case ECHO_REQUEST: 1469 l2cap_register_signaling_response(handle, code, sig_id, 0); 1470 return; 1471 1472 case INFORMATION_REQUEST: { 1473 uint16_t infoType = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1474 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1475 return; 1476 } 1477 1478 default: 1479 break; 1480 } 1481 1482 1483 // Get potential destination CID 1484 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1485 1486 // Find channel for this sig_id and connection handle 1487 btstack_linked_list_iterator_t it; 1488 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1489 while (btstack_linked_list_iterator_has_next(&it)){ 1490 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1491 if (channel->con_handle != handle) continue; 1492 if (code & 1) { 1493 // match odd commands (responses) by previous signaling identifier 1494 if (channel->local_sig_id == sig_id) { 1495 l2cap_signaling_handler_channel(channel, command); 1496 break; 1497 } 1498 } else { 1499 // match even commands (requests) by local channel id 1500 if (channel->local_cid == dest_cid) { 1501 l2cap_signaling_handler_channel(channel, command); 1502 break; 1503 } 1504 } 1505 } 1506 } 1507 1508 #ifdef ENABLE_BLE 1509 // @returns valid 1510 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 1511 hci_connection_t * connection; 1512 uint16_t result; 1513 uint8_t event[10]; 1514 uint16_t le_psm; 1515 l2cap_service_t * service; 1516 l2cap_channel_t * channel; 1517 btstack_linked_list_iterator_t it; 1518 1519 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1520 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 1521 1522 switch (code){ 1523 1524 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 1525 result = little_endian_read_16(command, 4); 1526 l2cap_emit_connection_parameter_update_response(handle, result); 1527 break; 1528 1529 case CONNECTION_PARAMETER_UPDATE_REQUEST: 1530 connection = hci_connection_for_handle(handle); 1531 if (connection){ 1532 if (connection->role != HCI_ROLE_MASTER){ 1533 // reject command without notifying upper layer when not in master role 1534 return 0; 1535 } 1536 int update_parameter = 1; 1537 le_connection_parameter_range_t existing_range; 1538 gap_get_connection_parameter_range(&existing_range); 1539 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 1540 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 1541 uint16_t le_conn_latency = little_endian_read_16(command,12); 1542 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 1543 1544 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 1545 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 1546 1547 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 1548 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 1549 1550 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 1551 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 1552 1553 if (update_parameter){ 1554 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 1555 connection->le_conn_interval_min = le_conn_interval_min; 1556 connection->le_conn_interval_max = le_conn_interval_max; 1557 connection->le_conn_latency = le_conn_latency; 1558 connection->le_supervision_timeout = le_supervision_timeout; 1559 } else { 1560 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 1561 } 1562 connection->le_con_param_update_identifier = sig_id; 1563 } 1564 1565 if (!l2cap_event_packet_handler) break; 1566 1567 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 1568 event[1] = 8; 1569 memcpy(&event[2], &command[4], 8); 1570 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1571 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1572 break; 1573 1574 case LE_CREDIT_BASED_CONNECTION_REQUEST: 1575 1576 // get hci connection, bail if not found (must not happen) 1577 connection = hci_connection_for_handle(handle); 1578 if (!connection) return 0; 1579 1580 // check if service registered 1581 le_psm = little_endian_read_16(command, 4); 1582 service = l2cap_le_get_service(le_psm); 1583 1584 if (service){ 1585 1586 uint16_t source_cid = little_endian_read_16(command, 6); 1587 if (source_cid < 0x40){ 1588 // 0x0009 Connection refused - Invalid Source CID 1589 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0009); 1590 return 1; 1591 } 1592 1593 // go through list of channels for this ACL connection and check if we get a match 1594 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1595 while (btstack_linked_list_iterator_has_next(&it)){ 1596 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1597 if (a_channel->con_handle != handle) continue; 1598 if (a_channel->remote_cid != source_cid) continue; 1599 // 0x000a Connection refused - Source CID already allocated 1600 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x000a); 1601 return 1; 1602 } 1603 1604 // TODO: deal with authentication requirements, errors 0x005 - 000x8 1605 1606 // allocate channel 1607 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 1608 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 1609 if (!channel){ 1610 // 0x0004 Connection refused – no resources available 1611 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0004); 1612 return 1; 1613 } 1614 1615 channel->con_handle = handle; 1616 channel->remote_cid = source_cid; 1617 channel->remote_sig_id = sig_id; 1618 1619 // limit local mtu to max acl packet length - l2cap header 1620 if (channel->local_mtu > l2cap_max_le_mtu()) { 1621 channel->local_mtu = l2cap_max_le_mtu(); 1622 } 1623 1624 // set initial state 1625 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1626 1627 // add to connections list 1628 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1629 1630 // post connection request event 1631 l2cap_emit_connection_request(channel); 1632 1633 } else { 1634 // Connection refused – LE_PSM not supported 1635 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0002); 1636 } 1637 break; 1638 1639 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 1640 // Find channel for this sig_id and connection handle 1641 channel = NULL; 1642 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1643 while (btstack_linked_list_iterator_has_next(&it)){ 1644 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1645 if (a_channel->con_handle != handle) continue; 1646 if (a_channel->local_sig_id != sig_id) continue; 1647 channel = a_channel; 1648 break; 1649 } 1650 // TODO: send error 1651 if (!channel) break; 1652 1653 // cid + 0 1654 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 1655 if (result){ 1656 channel->state = L2CAP_STATE_CLOSED; 1657 // map l2cap connection response result to BTstack status enumeration 1658 l2cap_emit_channel_opened(channel, result); 1659 1660 // discard channel 1661 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1662 btstack_memory_l2cap_channel_free(channel); 1663 break; 1664 } 1665 1666 // success 1667 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1668 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1669 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 1670 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 1671 channel->state = L2CAP_STATE_OPEN; 1672 l2cap_emit_channel_opened(channel, result); 1673 break; 1674 1675 default: 1676 // command unknown -> reject command 1677 return 0; 1678 } 1679 return 1; 1680 } 1681 #endif 1682 1683 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 1684 1685 // Get Channel ID 1686 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1687 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1688 1689 switch (channel_id) { 1690 1691 case L2CAP_CID_SIGNALING: { 1692 uint16_t command_offset = 8; 1693 while (command_offset < size) { 1694 // handle signaling commands 1695 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1696 1697 // increment command_offset 1698 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1699 } 1700 break; 1701 } 1702 1703 #ifdef ENABLE_BLE 1704 case L2CAP_CID_SIGNALING_LE: { 1705 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1706 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 1707 if (!valid){ 1708 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1709 } 1710 break; 1711 } 1712 #endif 1713 1714 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1715 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 1716 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1717 } 1718 break; 1719 1720 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1721 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 1722 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1723 } 1724 break; 1725 1726 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 1727 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 1728 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1729 } 1730 break; 1731 1732 default: { 1733 // Find channel for this channel_id and connection handle 1734 l2cap_channel_t * l2cap_channel; 1735 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 1736 if (l2cap_channel) { 1737 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1738 } 1739 #ifdef ENABLE_BLE 1740 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 1741 if (l2cap_channel) { 1742 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1743 } 1744 #endif 1745 break; 1746 } 1747 } 1748 1749 l2cap_run(); 1750 } 1751 1752 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1753 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 1754 channel->state = L2CAP_STATE_CLOSED; 1755 l2cap_emit_channel_closed(channel); 1756 // discard channel 1757 l2cap_stop_rtx(channel); 1758 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1759 btstack_memory_l2cap_channel_free(channel); 1760 } 1761 1762 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 1763 btstack_linked_list_iterator_t it; 1764 btstack_linked_list_iterator_init(&it, services); 1765 while (btstack_linked_list_iterator_has_next(&it)){ 1766 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 1767 if ( service->psm == psm){ 1768 return service; 1769 }; 1770 } 1771 return NULL; 1772 } 1773 1774 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 1775 return l2cap_get_service_internal(&l2cap_services, psm); 1776 } 1777 1778 1779 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 1780 1781 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1782 1783 // check for alread registered psm 1784 l2cap_service_t *service = l2cap_get_service(psm); 1785 if (service) { 1786 log_error("l2cap_register_service: PSM %u already registered", psm); 1787 return L2CAP_SERVICE_ALREADY_REGISTERED; 1788 } 1789 1790 // alloc structure 1791 service = btstack_memory_l2cap_service_get(); 1792 if (!service) { 1793 log_error("l2cap_register_service: no memory for l2cap_service_t"); 1794 return BTSTACK_MEMORY_ALLOC_FAILED; 1795 } 1796 1797 // fill in 1798 service->psm = psm; 1799 service->mtu = mtu; 1800 service->packet_handler = service_packet_handler; 1801 service->required_security_level = security_level; 1802 1803 // add to services list 1804 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 1805 1806 // enable page scan 1807 gap_connectable_control(1); 1808 1809 return 0; 1810 } 1811 1812 uint8_t l2cap_unregister_service(uint16_t psm){ 1813 1814 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1815 1816 l2cap_service_t *service = l2cap_get_service(psm); 1817 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 1818 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 1819 btstack_memory_l2cap_service_free(service); 1820 1821 // disable page scan when no services registered 1822 if (btstack_linked_list_empty(&l2cap_services)) { 1823 gap_connectable_control(0); 1824 } 1825 return 0; 1826 } 1827 1828 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1829 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 1830 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 1831 if (index < 0) return; 1832 fixed_channels[index].callback = the_packet_handler; 1833 } 1834 1835 #ifdef ENABLE_BLE 1836 1837 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 1838 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 1839 } 1840 1841 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 1842 1843 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 1844 1845 // check for alread registered psm 1846 l2cap_service_t *service = l2cap_le_get_service(psm); 1847 if (service) { 1848 return L2CAP_SERVICE_ALREADY_REGISTERED; 1849 } 1850 1851 // alloc structure 1852 service = btstack_memory_l2cap_service_get(); 1853 if (!service) { 1854 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 1855 return BTSTACK_MEMORY_ALLOC_FAILED; 1856 } 1857 1858 // fill in 1859 service->psm = psm; 1860 service->mtu = 0; 1861 service->packet_handler = packet_handler; 1862 service->required_security_level = security_level; 1863 1864 // add to services list 1865 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 1866 1867 // done 1868 return 0; 1869 } 1870 1871 uint8_t l2cap_le_unregister_service(uint16_t psm) { 1872 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 1873 l2cap_service_t *service = l2cap_le_get_service(psm); 1874 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 1875 1876 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 1877 btstack_memory_l2cap_service_free(service); 1878 return 0; 1879 } 1880 1881 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 1882 // get channel 1883 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 1884 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 1885 1886 // validate state 1887 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 1888 return ERROR_CODE_COMMAND_DISALLOWED; 1889 } 1890 1891 // set state accept connection 1892 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 1893 channel->receive_sdu_buffer = receive_sdu_buffer; 1894 channel->local_mtu = mtu; 1895 channel->credits_incoming = initial_credits; 1896 1897 // go 1898 l2cap_run(); 1899 return 0; 1900 } 1901 1902 /** 1903 * @brief Deny incoming LE Data Channel connection due to resource constraints 1904 * @param local_cid L2CAP LE Data Channel Identifier 1905 */ 1906 1907 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 1908 // get channel 1909 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 1910 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 1911 1912 // validate state 1913 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 1914 return ERROR_CODE_COMMAND_DISALLOWED; 1915 } 1916 1917 // set state decline connection 1918 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 1919 channel->reason = 0x04; // no resources available 1920 l2cap_run(); 1921 return 0; 1922 } 1923 1924 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 1925 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 1926 uint16_t * out_local_cid) { 1927 1928 log_info("L2CAP_LE_CREATE_CHANNEL addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 1929 1930 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, address, address_type, psm, mtu, LEVEL_0); 1931 if (!channel) { 1932 return BTSTACK_MEMORY_ALLOC_FAILED; 1933 } 1934 log_info("l2cap_le_create_channel %p", channel); 1935 1936 // store local_cid 1937 if (out_local_cid){ 1938 *out_local_cid = channel->local_cid; 1939 } 1940 1941 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 1942 1943 // add to connections list 1944 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1945 1946 // check if hci connection is already usable 1947 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, address_type); 1948 1949 if (conn){ 1950 log_info("l2cap_le_create_channel, hci connection already exists"); 1951 l2cap_handle_le_connection_complete(channel, 0, conn->con_handle); 1952 } else { 1953 1954 // 1955 // TODO: start timer 1956 // .. 1957 1958 // start connection 1959 uint8_t res = gap_auto_connection_start(address_type, address); 1960 if (res){ 1961 // discard channel object 1962 log_info("gap_auto_connection_start failed! 0x%02x", res); 1963 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1964 btstack_memory_l2cap_channel_free(channel); 1965 return res; 1966 } 1967 } 1968 return 0; 1969 } 1970 1971 /** 1972 * @brief Provide credtis for LE Data Channel 1973 * @param local_cid L2CAP LE Data Channel Identifier 1974 * @param credits Number additional credits for peer 1975 */ 1976 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 1977 // get channel 1978 // bail if missing 1979 // check state 1980 // check incoming credits + credits <= 0xffff 1981 // set credits_granted 1982 // l2cap_le_run() 1983 return 0; 1984 } 1985 1986 /** 1987 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 1988 * @param local_cid L2CAP LE Data Channel Identifier 1989 */ 1990 int l2cap_le_can_send_now(uint16_t local_cid){ 1991 // check if data can be sent via le at all 1992 return 0; 1993 } 1994 1995 /** 1996 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 1997 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 1998 * so packet handler should be ready to handle it 1999 * @param local_cid L2CAP LE Data Channel Identifier 2000 */ 2001 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 2002 // same as for non-le 2003 return 0; 2004 } 2005 2006 /** 2007 * @brief Send data via LE Data Channel 2008 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 2009 * @param local_cid L2CAP LE Data Channel Identifier 2010 * @param data data to send 2011 * @param size data size 2012 */ 2013 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 2014 2015 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2016 if (!channel) { 2017 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2018 return -1; // TODO: define error 2019 } 2020 2021 if (len > channel->remote_mtu){ 2022 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 2023 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 2024 } 2025 2026 if (!hci_can_send_acl_packet_now(channel->con_handle)){ 2027 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 2028 return BTSTACK_ACL_BUFFERS_FULL; 2029 } 2030 2031 hci_reserve_packet_buffer(); 2032 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 2033 2034 memcpy(&acl_buffer[8], data, len); 2035 2036 return l2cap_send_prepared_connectionless(channel->con_handle, local_cid, len); 2037 } 2038 2039 /** 2040 * @brief Disconnect from LE Data Channel 2041 * @param local_cid L2CAP LE Data Channel Identifier 2042 */ 2043 uint8_t l2cap_le_disconnect(uint16_t cid) 2044 { 2045 // find channel 2046 // check state 2047 // set state SEND_DISCONNECT 2048 return 0; 2049 } 2050 2051 #endif 2052