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 void l2cap_le_finialize_channel_close(l2cap_channel_t *channel); 89 static inline l2cap_service_t * l2cap_le_get_service(uint16_t psm); 90 #endif 91 92 typedef struct l2cap_fixed_channel { 93 btstack_packet_handler_t callback; 94 uint8_t waiting_for_can_send_now; 95 } l2cap_fixed_channel_t; 96 97 static btstack_linked_list_t l2cap_channels; 98 static btstack_linked_list_t l2cap_services; 99 static btstack_linked_list_t l2cap_le_channels; 100 static btstack_linked_list_t l2cap_le_services; 101 102 // used to cache l2cap rejects, echo, and informational requests 103 static l2cap_signaling_response_t signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; 104 static int signaling_responses_pending; 105 106 static uint8_t require_security_level2_for_outgoing_sdp; 107 108 static btstack_packet_callback_registration_t hci_event_callback_registration; 109 110 static btstack_packet_handler_t l2cap_event_packet_handler; 111 static l2cap_fixed_channel_t fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_SIZE]; 112 113 static uint16_t l2cap_fixed_channel_table_channel_id_for_index(int index){ 114 switch (index){ 115 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL: 116 return L2CAP_CID_ATTRIBUTE_PROTOCOL; 117 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL: 118 return L2CAP_CID_SECURITY_MANAGER_PROTOCOL; 119 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL: 120 return L2CAP_CID_CONNECTIONLESS_CHANNEL; 121 default: 122 return 0; 123 } 124 } 125 static int l2cap_fixed_channel_table_index_for_channel_id(uint16_t channel_id){ 126 switch (channel_id){ 127 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 128 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL; 129 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 130 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL; 131 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 132 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL; 133 default: 134 return -1; 135 } 136 } 137 138 static int l2cap_fixed_channel_table_index_is_le(int index){ 139 if (index == L2CAP_CID_CONNECTIONLESS_CHANNEL) return 0; 140 return 1; 141 } 142 143 void l2cap_init(void){ 144 signaling_responses_pending = 0; 145 146 l2cap_channels = NULL; 147 l2cap_services = NULL; 148 l2cap_le_services = NULL; 149 l2cap_le_channels = NULL; 150 151 l2cap_event_packet_handler = NULL; 152 memset(fixed_channels, 0, sizeof(fixed_channels)); 153 154 require_security_level2_for_outgoing_sdp = 0; 155 156 // 157 // register callback with HCI 158 // 159 hci_event_callback_registration.callback = &l2cap_hci_event_handler; 160 hci_add_event_handler(&hci_event_callback_registration); 161 162 hci_register_acl_packet_handler(&l2cap_acl_handler); 163 164 gap_connectable_control(0); // no services yet 165 } 166 167 void l2cap_register_packet_handler(void (*handler)(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 168 l2cap_event_packet_handler = handler; 169 } 170 171 static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 172 (* (channel->packet_handler))(type, channel->local_cid, data, size); 173 } 174 175 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 176 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", 177 status, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 178 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 179 uint8_t event[23]; 180 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 181 event[1] = sizeof(event) - 2; 182 event[2] = status; 183 reverse_bd_addr(channel->address, &event[3]); 184 little_endian_store_16(event, 9, channel->con_handle); 185 little_endian_store_16(event, 11, channel->psm); 186 little_endian_store_16(event, 13, channel->local_cid); 187 little_endian_store_16(event, 15, channel->remote_cid); 188 little_endian_store_16(event, 17, channel->local_mtu); 189 little_endian_store_16(event, 19, channel->remote_mtu); 190 little_endian_store_16(event, 21, channel->flush_timeout); 191 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 192 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 193 } 194 195 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 196 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 197 uint8_t event[4]; 198 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 199 event[1] = sizeof(event) - 2; 200 little_endian_store_16(event, 2, channel->local_cid); 201 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 202 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 203 } 204 205 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 206 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 207 bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid); 208 uint8_t event[16]; 209 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 210 event[1] = sizeof(event) - 2; 211 reverse_bd_addr(channel->address, &event[2]); 212 little_endian_store_16(event, 8, channel->con_handle); 213 little_endian_store_16(event, 10, channel->psm); 214 little_endian_store_16(event, 12, channel->local_cid); 215 little_endian_store_16(event, 14, channel->remote_cid); 216 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 217 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 218 } 219 220 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel) { 221 log_info("L2CAP_EVENT_CHANNEL_CAN_SEND_NOW local_cid 0x%x", channel); 222 uint8_t event[4]; 223 event[0] = L2CAP_EVENT_CAN_SEND_NOW; 224 event[1] = sizeof(event) - 2; 225 little_endian_store_16(event, 2, channel); 226 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 227 packet_handler(HCI_EVENT_PACKET, channel, event, sizeof(event)); 228 } 229 230 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 231 uint8_t event[6]; 232 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 233 event[1] = 4; 234 little_endian_store_16(event, 2, con_handle); 235 little_endian_store_16(event, 4, result); 236 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 237 if (!l2cap_event_packet_handler) return; 238 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 239 } 240 241 static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 242 btstack_linked_list_iterator_t it; 243 btstack_linked_list_iterator_init(&it, &l2cap_channels); 244 while (btstack_linked_list_iterator_has_next(&it)){ 245 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 246 if ( channel->local_cid == local_cid) { 247 return channel; 248 } 249 } 250 return NULL; 251 } 252 253 #ifdef ENABLE_BLE 254 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 255 btstack_linked_list_iterator_t it; 256 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 257 while (btstack_linked_list_iterator_has_next(&it)){ 258 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 259 if ( channel->local_cid == local_cid) { 260 return channel; 261 } 262 } 263 return NULL; 264 } 265 #endif 266 267 static l2cap_channel_t * l2cap_get_le_channel_for_address_and_addr_type(bd_addr_t address, bd_addr_type_t address_type){ 268 btstack_linked_list_iterator_t it; 269 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 270 while (btstack_linked_list_iterator_has_next(&it)){ 271 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 272 if (channel->address_type != address_type) continue; 273 if (bd_addr_cmp(channel->address, address)) continue; 274 return channel; 275 } 276 return NULL; 277 } 278 279 /// 280 281 void l2cap_request_can_send_now_event(uint16_t local_cid){ 282 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 283 if (!channel) return; 284 channel->waiting_for_can_send_now = 1; 285 l2cap_notify_channel_can_send(); 286 } 287 288 void l2cap_request_can_send_fix_channel_now_event(hci_con_handle_t con_handle, uint16_t channel_id){ 289 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 290 if (index < 0) return; 291 fixed_channels[index].waiting_for_can_send_now = 1; 292 l2cap_notify_channel_can_send(); 293 } 294 295 /// 296 297 int l2cap_can_send_packet_now(uint16_t local_cid){ 298 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 299 if (!channel) return 0; 300 return hci_can_send_acl_packet_now(channel->con_handle); 301 } 302 303 int l2cap_can_send_prepared_packet_now(uint16_t local_cid){ 304 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 305 if (!channel) return 0; 306 return hci_can_send_prepared_acl_packet_now(channel->con_handle); 307 } 308 309 int l2cap_can_send_fixed_channel_packet_now(hci_con_handle_t con_handle, uint16_t channel_id){ 310 return hci_can_send_acl_packet_now(con_handle); 311 } 312 313 /// 314 315 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 316 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 317 if (channel) { 318 return channel->remote_mtu; 319 } 320 return 0; 321 } 322 323 static l2cap_channel_t * l2cap_channel_for_rtx_timer(btstack_timer_source_t * ts){ 324 btstack_linked_list_iterator_t it; 325 btstack_linked_list_iterator_init(&it, &l2cap_channels); 326 while (btstack_linked_list_iterator_has_next(&it)){ 327 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 328 if ( &channel->rtx == ts) { 329 return channel; 330 } 331 } 332 return NULL; 333 } 334 335 static void l2cap_rtx_timeout(btstack_timer_source_t * ts){ 336 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 337 if (!channel) return; 338 339 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 340 341 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 342 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 343 // notify client 344 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 345 346 // discard channel 347 // no need to stop timer here, it is removed from list during timer callback 348 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 349 btstack_memory_l2cap_channel_free(channel); 350 } 351 352 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 353 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 354 btstack_run_loop_remove_timer(&channel->rtx); 355 } 356 357 static void l2cap_start_rtx(l2cap_channel_t * channel){ 358 l2cap_stop_rtx(channel); 359 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 360 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 361 btstack_run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 362 btstack_run_loop_add_timer(&channel->rtx); 363 } 364 365 static void l2cap_start_ertx(l2cap_channel_t * channel){ 366 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 367 l2cap_stop_rtx(channel); 368 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 369 btstack_run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 370 btstack_run_loop_add_timer(&channel->rtx); 371 } 372 373 void l2cap_require_security_level_2_for_outgoing_sdp(void){ 374 require_security_level2_for_outgoing_sdp = 1; 375 } 376 377 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 378 return (psm == PSM_SDP) && (!require_security_level2_for_outgoing_sdp); 379 } 380 381 static int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 382 383 if (!hci_can_send_acl_packet_now(handle)){ 384 log_info("l2cap_send_signaling_packet, cannot send"); 385 return BTSTACK_ACL_BUFFERS_FULL; 386 } 387 388 // log_info("l2cap_send_signaling_packet type %u", cmd); 389 hci_reserve_packet_buffer(); 390 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 391 va_list argptr; 392 va_start(argptr, identifier); 393 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 394 va_end(argptr); 395 // log_info("l2cap_send_signaling_packet con %u!", handle); 396 return hci_send_acl_packet_buffer(len); 397 } 398 399 #ifdef ENABLE_BLE 400 static int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 401 402 if (!hci_can_send_acl_packet_now(handle)){ 403 log_info("l2cap_send_signaling_packet, cannot send"); 404 return BTSTACK_ACL_BUFFERS_FULL; 405 } 406 407 // log_info("l2cap_send_signaling_packet type %u", cmd); 408 hci_reserve_packet_buffer(); 409 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 410 va_list argptr; 411 va_start(argptr, identifier); 412 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 413 va_end(argptr); 414 // log_info("l2cap_send_signaling_packet con %u!", handle); 415 return hci_send_acl_packet_buffer(len); 416 } 417 #endif 418 419 uint8_t *l2cap_get_outgoing_buffer(void){ 420 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 421 } 422 423 int l2cap_reserve_packet_buffer(void){ 424 return hci_reserve_packet_buffer(); 425 } 426 427 void l2cap_release_packet_buffer(void){ 428 hci_release_packet_buffer(); 429 } 430 431 432 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 433 434 if (!hci_is_packet_buffer_reserved()){ 435 log_error("l2cap_send_prepared called without reserving packet first"); 436 return BTSTACK_ACL_BUFFERS_FULL; 437 } 438 439 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 440 if (!channel) { 441 log_error("l2cap_send_prepared no channel for cid 0x%02x", local_cid); 442 return -1; // TODO: define error 443 } 444 445 if (!hci_can_send_prepared_acl_packet_now(channel->con_handle)){ 446 log_info("l2cap_send_prepared cid 0x%02x, cannot send", local_cid); 447 return BTSTACK_ACL_BUFFERS_FULL; 448 } 449 450 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used", local_cid, channel->con_handle); 451 452 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 453 454 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 455 456 // 0 - Connection handle : PB=pb : BC=00 457 little_endian_store_16(acl_buffer, 0, channel->con_handle | (pb << 12) | (0 << 14)); 458 // 2 - ACL length 459 little_endian_store_16(acl_buffer, 2, len + 4); 460 // 4 - L2CAP packet length 461 little_endian_store_16(acl_buffer, 4, len + 0); 462 // 6 - L2CAP channel DEST 463 little_endian_store_16(acl_buffer, 6, channel->remote_cid); 464 // send 465 int err = hci_send_acl_packet_buffer(len+8); 466 467 return err; 468 } 469 470 int l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len){ 471 472 if (!hci_is_packet_buffer_reserved()){ 473 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 474 return BTSTACK_ACL_BUFFERS_FULL; 475 } 476 477 if (!hci_can_send_prepared_acl_packet_now(con_handle)){ 478 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send", con_handle, cid); 479 return BTSTACK_ACL_BUFFERS_FULL; 480 } 481 482 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x", con_handle, cid); 483 484 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 485 486 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 487 488 // 0 - Connection handle : PB=pb : BC=00 489 little_endian_store_16(acl_buffer, 0, con_handle | (pb << 12) | (0 << 14)); 490 // 2 - ACL length 491 little_endian_store_16(acl_buffer, 2, len + 4); 492 // 4 - L2CAP packet length 493 little_endian_store_16(acl_buffer, 4, len + 0); 494 // 6 - L2CAP channel DEST 495 little_endian_store_16(acl_buffer, 6, cid); 496 // send 497 int err = hci_send_acl_packet_buffer(len+8); 498 499 return err; 500 } 501 502 int l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len){ 503 504 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 505 if (!channel) { 506 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 507 return -1; // TODO: define error 508 } 509 510 if (len > channel->remote_mtu){ 511 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 512 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 513 } 514 515 if (!hci_can_send_acl_packet_now(channel->con_handle)){ 516 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 517 return BTSTACK_ACL_BUFFERS_FULL; 518 } 519 520 hci_reserve_packet_buffer(); 521 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 522 523 memcpy(&acl_buffer[8], data, len); 524 525 return l2cap_send_prepared(local_cid, len); 526 } 527 528 int l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len){ 529 530 if (!hci_can_send_acl_packet_now(con_handle)){ 531 log_info("l2cap_send cid 0x%02x, cannot send", cid); 532 return BTSTACK_ACL_BUFFERS_FULL; 533 } 534 535 hci_reserve_packet_buffer(); 536 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 537 538 memcpy(&acl_buffer[8], data, len); 539 540 return l2cap_send_prepared_connectionless(con_handle, cid, len); 541 } 542 543 int l2cap_send_echo_request(hci_con_handle_t con_handle, uint8_t *data, uint16_t len){ 544 return l2cap_send_signaling_packet(con_handle, ECHO_REQUEST, 0x77, len, data); 545 } 546 547 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 548 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 549 } 550 551 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 552 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 553 } 554 555 556 557 // MARK: L2CAP_RUN 558 // process outstanding signaling tasks 559 static void l2cap_run(void){ 560 561 // log_info("l2cap_run: entered"); 562 563 // check pending signaling responses 564 while (signaling_responses_pending){ 565 566 hci_con_handle_t handle = signaling_responses[0].handle; 567 568 if (!hci_can_send_acl_packet_now(handle)) break; 569 570 uint8_t sig_id = signaling_responses[0].sig_id; 571 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 572 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 573 uint8_t response_code = signaling_responses[0].code; 574 575 // remove first item before sending (to avoid sending response mutliple times) 576 signaling_responses_pending--; 577 int i; 578 for (i=0; i < signaling_responses_pending; i++){ 579 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 580 } 581 582 switch (response_code){ 583 case CONNECTION_REQUEST: 584 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 585 // also disconnect if result is 0x0003 - security blocked 586 if (result == 0x0003){ 587 hci_disconnect_security_block(handle); 588 } 589 break; 590 case ECHO_REQUEST: 591 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 592 break; 593 case INFORMATION_REQUEST: 594 switch (infoType){ 595 case 1: { // Connectionless MTU 596 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 597 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 598 break; 599 } 600 case 2: { // Extended Features Supported 601 // extended features request supported, features: fixed channels, unicast connectionless data reception 602 uint32_t features = 0x280; 603 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 604 break; 605 } 606 case 3: { // Fixed Channels Supported 607 uint8_t map[8]; 608 memset(map, 0, 8); 609 map[0] = 0x06; // L2CAP Signaling Channel (0x02) + Connectionless reception (0x04) 610 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 611 break; 612 } 613 default: 614 // all other types are not supported 615 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 616 break; 617 } 618 break; 619 case COMMAND_REJECT: 620 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 621 #ifdef ENABLE_BLE 622 case COMMAND_REJECT_LE: 623 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 624 break; 625 #endif 626 default: 627 // should not happen 628 break; 629 } 630 } 631 632 uint8_t config_options[4]; 633 btstack_linked_list_iterator_t it; 634 btstack_linked_list_iterator_init(&it, &l2cap_channels); 635 while (btstack_linked_list_iterator_has_next(&it)){ 636 637 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 638 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 639 switch (channel->state){ 640 641 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 642 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 643 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 644 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 645 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 646 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 647 } 648 break; 649 650 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 651 if (!hci_can_send_command_packet_now()) break; 652 // send connection request - set state first 653 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 654 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 655 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 656 break; 657 658 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 659 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 660 channel->state = L2CAP_STATE_INVALID; 661 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 662 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 663 l2cap_stop_rtx(channel); 664 btstack_linked_list_iterator_remove(&it); 665 btstack_memory_l2cap_channel_free(channel); 666 break; 667 668 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 669 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 670 channel->state = L2CAP_STATE_CONFIG; 671 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 672 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 673 break; 674 675 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 676 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 677 // success, start l2cap handshake 678 channel->local_sig_id = l2cap_next_sig_id(); 679 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 680 l2cap_send_signaling_packet( channel->con_handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 681 l2cap_start_rtx(channel); 682 break; 683 684 case L2CAP_STATE_CONFIG: 685 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 686 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 687 uint16_t flags = 0; 688 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 689 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 690 flags = 1; 691 } else { 692 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 693 } 694 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 695 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 696 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 697 config_options[0] = 1; // MTU 698 config_options[1] = 2; // len param 699 little_endian_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 700 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 701 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 702 } else { 703 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 704 } 705 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 706 } 707 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 708 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 709 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 710 channel->local_sig_id = l2cap_next_sig_id(); 711 config_options[0] = 1; // MTU 712 config_options[1] = 2; // len param 713 little_endian_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 714 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 715 l2cap_start_rtx(channel); 716 } 717 if (l2cap_channel_ready_for_open(channel)){ 718 channel->state = L2CAP_STATE_OPEN; 719 l2cap_emit_channel_opened(channel, 0); // success 720 } 721 break; 722 723 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 724 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 725 channel->state = L2CAP_STATE_INVALID; 726 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 727 // 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 :) 728 l2cap_finialize_channel_close(channel); // -- remove from list 729 break; 730 731 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 732 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 733 channel->local_sig_id = l2cap_next_sig_id(); 734 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 735 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 736 break; 737 default: 738 break; 739 } 740 } 741 742 #ifdef ENABLE_BLE 743 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 744 while (btstack_linked_list_iterator_has_next(&it)){ 745 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 746 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 747 switch (channel->state){ 748 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 749 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 750 channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; 751 // le psm, source cid, mtu, mps, initial credits 752 channel->local_sig_id = l2cap_next_sig_id(); 753 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); 754 break; 755 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 756 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 757 // TODO: support larger MPS 758 channel->state = L2CAP_STATE_OPEN; 759 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); 760 // notify client 761 l2cap_emit_channel_opened(channel, 0); 762 break; 763 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 764 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 765 channel->state = L2CAP_STATE_INVALID; 766 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); 767 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 768 l2cap_stop_rtx(channel); 769 btstack_linked_list_iterator_remove(&it); 770 btstack_memory_l2cap_channel_free(channel); 771 break; 772 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 773 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 774 channel->local_sig_id = l2cap_next_sig_id(); 775 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 776 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 777 break; 778 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 779 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 780 channel->state = L2CAP_STATE_INVALID; 781 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 782 l2cap_le_finialize_channel_close(channel); // -- remove from list 783 break; 784 default: 785 break; 786 } 787 } 788 789 // send l2cap con paramter update if necessary 790 hci_connections_get_iterator(&it); 791 while(btstack_linked_list_iterator_has_next(&it)){ 792 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 793 if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; 794 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 795 switch (connection->le_con_parameter_update_state){ 796 case CON_PARAMETER_UPDATE_SEND_REQUEST: 797 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 798 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, connection->le_con_param_update_identifier, 799 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 800 break; 801 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 802 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 803 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 804 break; 805 case CON_PARAMETER_UPDATE_DENY: 806 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 807 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 808 break; 809 default: 810 break; 811 } 812 #if 0 813 void l2cap_le_run(void){ 814 for all channels 815 switch(state): 816 817 if outgoing transfer active 818 send next chunk 819 if done, notify app 820 } 821 #endif 822 } 823 #endif 824 825 // log_info("l2cap_run: exit"); 826 } 827 828 uint16_t l2cap_max_mtu(void){ 829 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 830 } 831 832 uint16_t l2cap_max_le_mtu(void){ 833 return l2cap_max_mtu(); 834 } 835 836 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 837 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 838 log_info("l2cap_handle_connection_complete expected state"); 839 // success, start l2cap handshake 840 channel->con_handle = con_handle; 841 // check remote SSP feature first 842 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 843 } 844 } 845 846 #ifdef ENABLE_BLE 847 static void l2cap_handle_le_connection_complete(l2cap_channel_t * channel, uint8_t status, hci_con_handle_t con_handle){ 848 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 849 log_info("l2cap_le_handle_connection_complete expected state"); 850 // TODO: bail if status != 0 851 852 // success, start l2cap handshake 853 channel->con_handle = con_handle; 854 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 855 } 856 } 857 #endif 858 859 860 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 861 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 862 863 // we have been waiting for remote supported features, if both support SSP, 864 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)); 865 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 866 // request security level 2 867 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 868 gap_request_security_level(channel->con_handle, LEVEL_2); 869 return; 870 } 871 // fine, go ahead 872 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 873 } 874 875 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 876 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 877 878 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 879 if (!channel) { 880 return NULL; 881 } 882 883 // Init memory (make valgrind happy) 884 memset(channel, 0, sizeof(l2cap_channel_t)); 885 886 // fill in 887 channel->packet_handler = packet_handler; 888 bd_addr_copy(channel->address, address); 889 channel->address_type = address_type; 890 channel->psm = psm; 891 channel->local_mtu = local_mtu; 892 channel->remote_mtu = L2CAP_MINIMAL_MTU; 893 channel->required_security_level = security_level; 894 895 // 896 channel->local_cid = l2cap_next_local_cid(); 897 channel->con_handle = 0; 898 899 // set initial state 900 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 901 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 902 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 903 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 904 return channel; 905 } 906 907 /** 908 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 909 * @param packet_handler 910 * @param address 911 * @param psm 912 * @param mtu 913 * @param local_cid 914 */ 915 916 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){ 917 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, local_mtu); 918 919 if (local_mtu > l2cap_max_mtu()) { 920 local_mtu = l2cap_max_mtu(); 921 } 922 923 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 924 if (!channel) { 925 return BTSTACK_MEMORY_ALLOC_FAILED; 926 } 927 928 // add to connections list 929 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 930 931 // store local_cid 932 if (out_local_cid){ 933 *out_local_cid = channel->local_cid; 934 } 935 936 // check if hci connection is already usable 937 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 938 if (conn){ 939 log_info("l2cap_create_channel, hci connection already exists"); 940 l2cap_handle_connection_complete(conn->con_handle, channel); 941 // check if remote supported fearures are already received 942 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 943 l2cap_handle_remote_supported_features_received(channel); 944 } 945 } 946 947 l2cap_run(); 948 949 return 0; 950 } 951 952 void 953 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 954 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 955 // find channel for local_cid 956 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 957 if (channel) { 958 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 959 } 960 // process 961 l2cap_run(); 962 } 963 964 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 965 btstack_linked_list_iterator_t it; 966 btstack_linked_list_iterator_init(&it, &l2cap_channels); 967 while (btstack_linked_list_iterator_has_next(&it)){ 968 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 969 if ( bd_addr_cmp( channel->address, address) != 0) continue; 970 // channel for this address found 971 switch (channel->state){ 972 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 973 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 974 // failure, forward error code 975 l2cap_emit_channel_opened(channel, status); 976 // discard channel 977 l2cap_stop_rtx(channel); 978 btstack_linked_list_iterator_remove(&it); 979 btstack_memory_l2cap_channel_free(channel); 980 break; 981 default: 982 break; 983 } 984 } 985 } 986 987 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 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 ( ! bd_addr_cmp( channel->address, address) ){ 993 l2cap_handle_connection_complete(handle, channel); 994 } 995 } 996 // process 997 l2cap_run(); 998 } 999 1000 static void l2cap_notify_channel_can_send(void){ 1001 btstack_linked_list_iterator_t it; 1002 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1003 while (btstack_linked_list_iterator_has_next(&it)){ 1004 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1005 if (!channel->waiting_for_can_send_now) continue; 1006 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1007 channel->waiting_for_can_send_now = 0; 1008 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1009 } 1010 1011 int i; 1012 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1013 if (!fixed_channels[i].callback) continue; 1014 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1015 int can_send; 1016 if (l2cap_fixed_channel_table_index_is_le(i)){ 1017 can_send = hci_can_send_acl_le_packet_now(); 1018 } else { 1019 can_send = hci_can_send_acl_classic_packet_now(); 1020 } 1021 if (!can_send) continue; 1022 fixed_channels[i].waiting_for_can_send_now = 0; 1023 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1024 } 1025 } 1026 1027 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1028 1029 bd_addr_t address; 1030 hci_con_handle_t handle; 1031 btstack_linked_list_iterator_t it; 1032 int hci_con_used; 1033 1034 switch(hci_event_packet_get_type(packet)){ 1035 1036 // handle connection complete events 1037 case HCI_EVENT_CONNECTION_COMPLETE: 1038 reverse_bd_addr(&packet[5], address); 1039 if (packet[2] == 0){ 1040 handle = little_endian_read_16(packet, 3); 1041 l2cap_handle_connection_success_for_addr(address, handle); 1042 } else { 1043 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1044 } 1045 break; 1046 1047 // handle successful create connection cancel command 1048 case HCI_EVENT_COMMAND_COMPLETE: 1049 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1050 if (packet[5] == 0){ 1051 reverse_bd_addr(&packet[6], address); 1052 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1053 l2cap_handle_connection_failed_for_addr(address, 0x16); 1054 } 1055 } 1056 l2cap_run(); // try sending signaling packets first 1057 break; 1058 1059 case HCI_EVENT_COMMAND_STATUS: 1060 l2cap_run(); // try sending signaling packets first 1061 break; 1062 1063 // handle disconnection complete events 1064 case HCI_EVENT_DISCONNECTION_COMPLETE: 1065 // send l2cap disconnect events for all channels on this handle and free them 1066 handle = little_endian_read_16(packet, 3); 1067 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1068 while (btstack_linked_list_iterator_has_next(&it)){ 1069 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1070 if (channel->con_handle != handle) continue; 1071 l2cap_emit_channel_closed(channel); 1072 l2cap_stop_rtx(channel); 1073 btstack_linked_list_iterator_remove(&it); 1074 btstack_memory_l2cap_channel_free(channel); 1075 } 1076 #ifdef ENABLE_BLE 1077 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1078 while (btstack_linked_list_iterator_has_next(&it)){ 1079 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1080 if (channel->con_handle != handle) continue; 1081 l2cap_emit_channel_closed(channel); 1082 btstack_linked_list_iterator_remove(&it); 1083 btstack_memory_l2cap_channel_free(channel); 1084 } 1085 #endif 1086 break; 1087 1088 // Notify channel packet handler if they can send now 1089 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1090 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1091 l2cap_run(); // try sending signaling packets first 1092 l2cap_notify_channel_can_send(); 1093 break; 1094 1095 // HCI Connection Timeouts 1096 case L2CAP_EVENT_TIMEOUT_CHECK: 1097 handle = little_endian_read_16(packet, 2); 1098 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1099 if (hci_authentication_active_for_handle(handle)) break; 1100 hci_con_used = 0; 1101 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1102 while (btstack_linked_list_iterator_has_next(&it)){ 1103 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1104 if (channel->con_handle != handle) continue; 1105 hci_con_used = 1; 1106 break; 1107 } 1108 if (hci_con_used) break; 1109 if (!hci_can_send_command_packet_now()) break; 1110 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1111 break; 1112 1113 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1114 handle = little_endian_read_16(packet, 3); 1115 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1116 while (btstack_linked_list_iterator_has_next(&it)){ 1117 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1118 if (channel->con_handle != handle) continue; 1119 l2cap_handle_remote_supported_features_received(channel); 1120 break; 1121 } 1122 break; 1123 1124 #ifdef ENABLE_BLE 1125 case HCI_EVENT_LE_META: 1126 switch (packet[2]){ 1127 int addr_type; 1128 l2cap_channel_t * channel; 1129 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 1130 // Connection management 1131 reverse_bd_addr(&packet[8], address); 1132 addr_type = (bd_addr_type_t)packet[7]; 1133 log_info("L2CAP - LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(address)); 1134 // get l2cap_channel 1135 // also pass in status 1136 channel = l2cap_get_le_channel_for_address_and_addr_type(address, addr_type); 1137 if (!channel) break; 1138 l2cap_handle_le_connection_complete(channel, packet[3], little_endian_read_16(packet, 4)); 1139 break; 1140 default: 1141 break; 1142 } 1143 break; 1144 #endif 1145 1146 case GAP_EVENT_SECURITY_LEVEL: 1147 handle = little_endian_read_16(packet, 2); 1148 log_info("l2cap - security level update"); 1149 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1150 while (btstack_linked_list_iterator_has_next(&it)){ 1151 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1152 if (channel->con_handle != handle) continue; 1153 1154 log_info("l2cap - state %u", channel->state); 1155 1156 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1157 gap_security_level_t required_level = channel->required_security_level; 1158 1159 switch (channel->state){ 1160 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1161 if (actual_level >= required_level){ 1162 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1163 l2cap_emit_connection_request(channel); 1164 } else { 1165 channel->reason = 0x0003; // security block 1166 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1167 } 1168 break; 1169 1170 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1171 if (actual_level >= required_level){ 1172 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1173 } else { 1174 // disconnnect, authentication not good enough 1175 hci_disconnect_security_block(handle); 1176 } 1177 break; 1178 1179 default: 1180 break; 1181 } 1182 } 1183 break; 1184 1185 default: 1186 break; 1187 } 1188 1189 l2cap_run(); 1190 } 1191 1192 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1193 channel->remote_sig_id = identifier; 1194 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1195 l2cap_run(); 1196 } 1197 1198 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 1199 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1200 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1201 signaling_responses[signaling_responses_pending].handle = handle; 1202 signaling_responses[signaling_responses_pending].code = code; 1203 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1204 signaling_responses[signaling_responses_pending].data = data; 1205 signaling_responses_pending++; 1206 l2cap_run(); 1207 } 1208 } 1209 1210 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1211 1212 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1213 l2cap_service_t *service = l2cap_get_service(psm); 1214 if (!service) { 1215 // 0x0002 PSM not supported 1216 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 1217 return; 1218 } 1219 1220 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1221 if (!hci_connection) { 1222 // 1223 log_error("no hci_connection for handle %u", handle); 1224 return; 1225 } 1226 1227 // alloc structure 1228 // log_info("l2cap_handle_connection_request register channel"); 1229 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 1230 psm, service->mtu, service->required_security_level); 1231 if (!channel){ 1232 // 0x0004 No resources available 1233 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 1234 return; 1235 } 1236 1237 channel->con_handle = handle; 1238 channel->remote_cid = source_cid; 1239 channel->remote_sig_id = sig_id; 1240 1241 // limit local mtu to max acl packet length - l2cap header 1242 if (channel->local_mtu > l2cap_max_mtu()) { 1243 channel->local_mtu = l2cap_max_mtu(); 1244 } 1245 1246 // set initial state 1247 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1248 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 1249 1250 // add to connections list 1251 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1252 1253 // assert security requirements 1254 gap_request_security_level(handle, channel->required_security_level); 1255 } 1256 1257 void l2cap_accept_connection(uint16_t local_cid){ 1258 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1259 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1260 if (!channel) { 1261 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1262 return; 1263 } 1264 1265 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1266 1267 // process 1268 l2cap_run(); 1269 } 1270 1271 void l2cap_decline_connection(uint16_t local_cid){ 1272 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 1273 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1274 if (!channel) { 1275 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1276 return; 1277 } 1278 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1279 channel->reason = 0x04; // no resources available 1280 l2cap_run(); 1281 } 1282 1283 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1284 1285 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1286 1287 uint16_t flags = little_endian_read_16(command, 6); 1288 if (flags & 1) { 1289 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1290 } 1291 1292 // accept the other's configuration options 1293 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1294 uint16_t pos = 8; 1295 while (pos < end_pos){ 1296 uint8_t option_hint = command[pos] >> 7; 1297 uint8_t option_type = command[pos] & 0x7f; 1298 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1299 pos++; 1300 uint8_t length = command[pos++]; 1301 // MTU { type(8): 1, len(8):2, MTU(16) } 1302 if (option_type == 1 && length == 2){ 1303 channel->remote_mtu = little_endian_read_16(command, pos); 1304 // log_info("l2cap cid 0x%02x, remote mtu %u", channel->local_cid, channel->remote_mtu); 1305 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1306 } 1307 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1308 if (option_type == 2 && length == 2){ 1309 channel->flush_timeout = little_endian_read_16(command, pos); 1310 } 1311 // check for unknown options 1312 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1313 log_info("l2cap cid %u, unknown options", channel->local_cid); 1314 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1315 } 1316 pos += length; 1317 } 1318 } 1319 1320 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1321 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1322 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1323 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1324 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 1325 if (channel->state == L2CAP_STATE_OPEN) return 0; 1326 return 1; 1327 } 1328 1329 1330 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1331 1332 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1333 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1334 uint16_t result = 0; 1335 1336 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1337 1338 // handle DISCONNECT REQUESTS seperately 1339 if (code == DISCONNECTION_REQUEST){ 1340 switch (channel->state){ 1341 case L2CAP_STATE_CONFIG: 1342 case L2CAP_STATE_OPEN: 1343 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1344 case L2CAP_STATE_WAIT_DISCONNECT: 1345 l2cap_handle_disconnect_request(channel, identifier); 1346 break; 1347 1348 default: 1349 // ignore in other states 1350 break; 1351 } 1352 return; 1353 } 1354 1355 // @STATEMACHINE(l2cap) 1356 switch (channel->state) { 1357 1358 case L2CAP_STATE_WAIT_CONNECT_RSP: 1359 switch (code){ 1360 case CONNECTION_RESPONSE: 1361 l2cap_stop_rtx(channel); 1362 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1363 switch (result) { 1364 case 0: 1365 // successful connection 1366 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1367 channel->state = L2CAP_STATE_CONFIG; 1368 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1369 break; 1370 case 1: 1371 // connection pending. get some coffee, but start the ERTX 1372 l2cap_start_ertx(channel); 1373 break; 1374 default: 1375 // channel closed 1376 channel->state = L2CAP_STATE_CLOSED; 1377 // map l2cap connection response result to BTstack status enumeration 1378 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1379 1380 // drop link key if security block 1381 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1382 gap_drop_link_key_for_bd_addr(channel->address); 1383 } 1384 1385 // discard channel 1386 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1387 btstack_memory_l2cap_channel_free(channel); 1388 break; 1389 } 1390 break; 1391 1392 default: 1393 //@TODO: implement other signaling packets 1394 break; 1395 } 1396 break; 1397 1398 case L2CAP_STATE_CONFIG: 1399 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1400 switch (code) { 1401 case CONFIGURE_REQUEST: 1402 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1403 l2cap_signaling_handle_configure_request(channel, command); 1404 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1405 // only done if continuation not set 1406 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1407 } 1408 break; 1409 case CONFIGURE_RESPONSE: 1410 l2cap_stop_rtx(channel); 1411 switch (result){ 1412 case 0: // success 1413 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1414 break; 1415 case 4: // pending 1416 l2cap_start_ertx(channel); 1417 break; 1418 default: 1419 // retry on negative result 1420 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1421 break; 1422 } 1423 break; 1424 default: 1425 break; 1426 } 1427 if (l2cap_channel_ready_for_open(channel)){ 1428 // for open: 1429 channel->state = L2CAP_STATE_OPEN; 1430 l2cap_emit_channel_opened(channel, 0); 1431 } 1432 break; 1433 1434 case L2CAP_STATE_WAIT_DISCONNECT: 1435 switch (code) { 1436 case DISCONNECTION_RESPONSE: 1437 l2cap_finialize_channel_close(channel); 1438 break; 1439 default: 1440 //@TODO: implement other signaling packets 1441 break; 1442 } 1443 break; 1444 1445 case L2CAP_STATE_CLOSED: 1446 // @TODO handle incoming requests 1447 break; 1448 1449 case L2CAP_STATE_OPEN: 1450 //@TODO: implement other signaling packets, e.g. re-configure 1451 break; 1452 default: 1453 break; 1454 } 1455 // log_info("new state %u", channel->state); 1456 } 1457 1458 1459 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1460 1461 // get code, signalind identifier and command len 1462 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1463 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1464 1465 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1466 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1467 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1468 return; 1469 } 1470 1471 // general commands without an assigned channel 1472 switch(code) { 1473 1474 case CONNECTION_REQUEST: { 1475 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1476 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1477 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1478 return; 1479 } 1480 1481 case ECHO_REQUEST: 1482 l2cap_register_signaling_response(handle, code, sig_id, 0); 1483 return; 1484 1485 case INFORMATION_REQUEST: { 1486 uint16_t infoType = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1487 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1488 return; 1489 } 1490 1491 default: 1492 break; 1493 } 1494 1495 1496 // Get potential destination CID 1497 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1498 1499 // Find channel for this sig_id and connection handle 1500 btstack_linked_list_iterator_t it; 1501 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1502 while (btstack_linked_list_iterator_has_next(&it)){ 1503 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1504 if (channel->con_handle != handle) continue; 1505 if (code & 1) { 1506 // match odd commands (responses) by previous signaling identifier 1507 if (channel->local_sig_id == sig_id) { 1508 l2cap_signaling_handler_channel(channel, command); 1509 break; 1510 } 1511 } else { 1512 // match even commands (requests) by local channel id 1513 if (channel->local_cid == dest_cid) { 1514 l2cap_signaling_handler_channel(channel, command); 1515 break; 1516 } 1517 } 1518 } 1519 } 1520 1521 #ifdef ENABLE_BLE 1522 // @returns valid 1523 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 1524 hci_connection_t * connection; 1525 uint16_t result; 1526 uint8_t event[10]; 1527 uint16_t le_psm; 1528 uint16_t local_cid; 1529 l2cap_service_t * service; 1530 l2cap_channel_t * channel; 1531 btstack_linked_list_iterator_t it; 1532 1533 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1534 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 1535 1536 switch (code){ 1537 1538 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 1539 result = little_endian_read_16(command, 4); 1540 l2cap_emit_connection_parameter_update_response(handle, result); 1541 break; 1542 1543 case CONNECTION_PARAMETER_UPDATE_REQUEST: 1544 connection = hci_connection_for_handle(handle); 1545 if (connection){ 1546 if (connection->role != HCI_ROLE_MASTER){ 1547 // reject command without notifying upper layer when not in master role 1548 return 0; 1549 } 1550 int update_parameter = 1; 1551 le_connection_parameter_range_t existing_range; 1552 gap_get_connection_parameter_range(&existing_range); 1553 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 1554 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 1555 uint16_t le_conn_latency = little_endian_read_16(command,12); 1556 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 1557 1558 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 1559 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 1560 1561 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 1562 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 1563 1564 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 1565 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 1566 1567 if (update_parameter){ 1568 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 1569 connection->le_conn_interval_min = le_conn_interval_min; 1570 connection->le_conn_interval_max = le_conn_interval_max; 1571 connection->le_conn_latency = le_conn_latency; 1572 connection->le_supervision_timeout = le_supervision_timeout; 1573 } else { 1574 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 1575 } 1576 connection->le_con_param_update_identifier = sig_id; 1577 } 1578 1579 if (!l2cap_event_packet_handler) break; 1580 1581 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 1582 event[1] = 8; 1583 memcpy(&event[2], &command[4], 8); 1584 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1585 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1586 break; 1587 1588 case LE_CREDIT_BASED_CONNECTION_REQUEST: 1589 1590 // get hci connection, bail if not found (must not happen) 1591 connection = hci_connection_for_handle(handle); 1592 if (!connection) return 0; 1593 1594 // check if service registered 1595 le_psm = little_endian_read_16(command, 4); 1596 service = l2cap_le_get_service(le_psm); 1597 1598 if (service){ 1599 1600 uint16_t source_cid = little_endian_read_16(command, 6); 1601 if (source_cid < 0x40){ 1602 // 0x0009 Connection refused - Invalid Source CID 1603 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0009); 1604 return 1; 1605 } 1606 1607 // go through list of channels for this ACL connection and check if we get a match 1608 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1609 while (btstack_linked_list_iterator_has_next(&it)){ 1610 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1611 if (a_channel->con_handle != handle) continue; 1612 if (a_channel->remote_cid != source_cid) continue; 1613 // 0x000a Connection refused - Source CID already allocated 1614 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x000a); 1615 return 1; 1616 } 1617 1618 // TODO: deal with authentication requirements, errors 0x005 - 000x8 1619 1620 // allocate channel 1621 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 1622 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 1623 if (!channel){ 1624 // 0x0004 Connection refused – no resources available 1625 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0004); 1626 return 1; 1627 } 1628 1629 channel->con_handle = handle; 1630 channel->remote_cid = source_cid; 1631 channel->remote_sig_id = sig_id; 1632 1633 // limit local mtu to max acl packet length - l2cap header 1634 if (channel->local_mtu > l2cap_max_le_mtu()) { 1635 channel->local_mtu = l2cap_max_le_mtu(); 1636 } 1637 1638 // set initial state 1639 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1640 1641 // add to connections list 1642 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1643 1644 // post connection request event 1645 l2cap_emit_connection_request(channel); 1646 1647 } else { 1648 // Connection refused – LE_PSM not supported 1649 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0002); 1650 } 1651 break; 1652 1653 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 1654 // Find channel for this sig_id and connection handle 1655 channel = NULL; 1656 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1657 while (btstack_linked_list_iterator_has_next(&it)){ 1658 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1659 if (a_channel->con_handle != handle) continue; 1660 if (a_channel->local_sig_id != sig_id) continue; 1661 channel = a_channel; 1662 break; 1663 } 1664 // TODO: send error 1665 if (!channel) break; 1666 1667 // cid + 0 1668 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 1669 if (result){ 1670 channel->state = L2CAP_STATE_CLOSED; 1671 // map l2cap connection response result to BTstack status enumeration 1672 l2cap_emit_channel_opened(channel, result); 1673 1674 // discard channel 1675 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1676 btstack_memory_l2cap_channel_free(channel); 1677 break; 1678 } 1679 1680 // success 1681 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1682 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1683 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 1684 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 1685 channel->state = L2CAP_STATE_OPEN; 1686 l2cap_emit_channel_opened(channel, result); 1687 break; 1688 1689 case DISCONNECTION_REQUEST: 1690 // find channel 1691 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1692 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1693 if (!channel) break; 1694 channel->remote_sig_id = sig_id; 1695 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1696 break; 1697 1698 default: 1699 // command unknown -> reject command 1700 return 0; 1701 } 1702 return 1; 1703 } 1704 #endif 1705 1706 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 1707 1708 // Get Channel ID 1709 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1710 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1711 1712 switch (channel_id) { 1713 1714 case L2CAP_CID_SIGNALING: { 1715 uint16_t command_offset = 8; 1716 while (command_offset < size) { 1717 // handle signaling commands 1718 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1719 1720 // increment command_offset 1721 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1722 } 1723 break; 1724 } 1725 1726 #ifdef ENABLE_BLE 1727 case L2CAP_CID_SIGNALING_LE: { 1728 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1729 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 1730 if (!valid){ 1731 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1732 } 1733 break; 1734 } 1735 #endif 1736 1737 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1738 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 1739 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1740 } 1741 break; 1742 1743 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1744 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 1745 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1746 } 1747 break; 1748 1749 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 1750 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 1751 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1752 } 1753 break; 1754 1755 default: { 1756 // Find channel for this channel_id and connection handle 1757 l2cap_channel_t * l2cap_channel; 1758 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 1759 if (l2cap_channel) { 1760 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1761 } 1762 #ifdef ENABLE_BLE 1763 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 1764 if (l2cap_channel) { 1765 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1766 } 1767 #endif 1768 break; 1769 } 1770 } 1771 1772 l2cap_run(); 1773 } 1774 1775 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1776 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 1777 channel->state = L2CAP_STATE_CLOSED; 1778 l2cap_emit_channel_closed(channel); 1779 // discard channel 1780 l2cap_stop_rtx(channel); 1781 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1782 btstack_memory_l2cap_channel_free(channel); 1783 } 1784 1785 #ifdef ENABLE_BLE 1786 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1787 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 1788 channel->state = L2CAP_STATE_CLOSED; 1789 l2cap_emit_channel_closed(channel); 1790 // discard channel 1791 l2cap_stop_rtx(channel); 1792 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1793 btstack_memory_l2cap_channel_free(channel); 1794 } 1795 #endif 1796 1797 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 1798 btstack_linked_list_iterator_t it; 1799 btstack_linked_list_iterator_init(&it, services); 1800 while (btstack_linked_list_iterator_has_next(&it)){ 1801 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 1802 if ( service->psm == psm){ 1803 return service; 1804 }; 1805 } 1806 return NULL; 1807 } 1808 1809 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 1810 return l2cap_get_service_internal(&l2cap_services, psm); 1811 } 1812 1813 1814 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 1815 1816 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1817 1818 // check for alread registered psm 1819 l2cap_service_t *service = l2cap_get_service(psm); 1820 if (service) { 1821 log_error("l2cap_register_service: PSM %u already registered", psm); 1822 return L2CAP_SERVICE_ALREADY_REGISTERED; 1823 } 1824 1825 // alloc structure 1826 service = btstack_memory_l2cap_service_get(); 1827 if (!service) { 1828 log_error("l2cap_register_service: no memory for l2cap_service_t"); 1829 return BTSTACK_MEMORY_ALLOC_FAILED; 1830 } 1831 1832 // fill in 1833 service->psm = psm; 1834 service->mtu = mtu; 1835 service->packet_handler = service_packet_handler; 1836 service->required_security_level = security_level; 1837 1838 // add to services list 1839 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 1840 1841 // enable page scan 1842 gap_connectable_control(1); 1843 1844 return 0; 1845 } 1846 1847 uint8_t l2cap_unregister_service(uint16_t psm){ 1848 1849 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1850 1851 l2cap_service_t *service = l2cap_get_service(psm); 1852 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 1853 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 1854 btstack_memory_l2cap_service_free(service); 1855 1856 // disable page scan when no services registered 1857 if (btstack_linked_list_empty(&l2cap_services)) { 1858 gap_connectable_control(0); 1859 } 1860 return 0; 1861 } 1862 1863 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1864 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 1865 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 1866 if (index < 0) return; 1867 fixed_channels[index].callback = the_packet_handler; 1868 } 1869 1870 #ifdef ENABLE_BLE 1871 1872 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 1873 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 1874 } 1875 1876 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 1877 1878 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 1879 1880 // check for alread registered psm 1881 l2cap_service_t *service = l2cap_le_get_service(psm); 1882 if (service) { 1883 return L2CAP_SERVICE_ALREADY_REGISTERED; 1884 } 1885 1886 // alloc structure 1887 service = btstack_memory_l2cap_service_get(); 1888 if (!service) { 1889 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 1890 return BTSTACK_MEMORY_ALLOC_FAILED; 1891 } 1892 1893 // fill in 1894 service->psm = psm; 1895 service->mtu = 0; 1896 service->packet_handler = packet_handler; 1897 service->required_security_level = security_level; 1898 1899 // add to services list 1900 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 1901 1902 // done 1903 return 0; 1904 } 1905 1906 uint8_t l2cap_le_unregister_service(uint16_t psm) { 1907 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 1908 l2cap_service_t *service = l2cap_le_get_service(psm); 1909 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 1910 1911 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 1912 btstack_memory_l2cap_service_free(service); 1913 return 0; 1914 } 1915 1916 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 1917 // get channel 1918 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 1919 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 1920 1921 // validate state 1922 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 1923 return ERROR_CODE_COMMAND_DISALLOWED; 1924 } 1925 1926 // set state accept connection 1927 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 1928 channel->receive_sdu_buffer = receive_sdu_buffer; 1929 channel->local_mtu = mtu; 1930 channel->credits_incoming = initial_credits; 1931 1932 // go 1933 l2cap_run(); 1934 return 0; 1935 } 1936 1937 /** 1938 * @brief Deny incoming LE Data Channel connection due to resource constraints 1939 * @param local_cid L2CAP LE Data Channel Identifier 1940 */ 1941 1942 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 1943 // get channel 1944 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 1945 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 1946 1947 // validate state 1948 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 1949 return ERROR_CODE_COMMAND_DISALLOWED; 1950 } 1951 1952 // set state decline connection 1953 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 1954 channel->reason = 0x04; // no resources available 1955 l2cap_run(); 1956 return 0; 1957 } 1958 1959 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 1960 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 1961 uint16_t * out_local_cid) { 1962 1963 log_info("L2CAP_LE_CREATE_CHANNEL addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 1964 1965 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, address, address_type, psm, mtu, LEVEL_0); 1966 if (!channel) { 1967 return BTSTACK_MEMORY_ALLOC_FAILED; 1968 } 1969 log_info("l2cap_le_create_channel %p", channel); 1970 1971 // store local_cid 1972 if (out_local_cid){ 1973 *out_local_cid = channel->local_cid; 1974 } 1975 1976 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 1977 1978 // add to connections list 1979 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1980 1981 // check if hci connection is already usable 1982 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, address_type); 1983 1984 if (conn){ 1985 log_info("l2cap_le_create_channel, hci connection already exists"); 1986 l2cap_handle_le_connection_complete(channel, 0, conn->con_handle); 1987 } else { 1988 1989 // 1990 // TODO: start timer 1991 // .. 1992 1993 // start connection 1994 uint8_t res = gap_auto_connection_start(address_type, address); 1995 if (res){ 1996 // discard channel object 1997 log_info("gap_auto_connection_start failed! 0x%02x", res); 1998 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1999 btstack_memory_l2cap_channel_free(channel); 2000 return res; 2001 } 2002 } 2003 return 0; 2004 } 2005 2006 /** 2007 * @brief Provide credtis for LE Data Channel 2008 * @param local_cid L2CAP LE Data Channel Identifier 2009 * @param credits Number additional credits for peer 2010 */ 2011 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 2012 // get channel 2013 // bail if missing 2014 // check state 2015 // check incoming credits + credits <= 0xffff 2016 // set credits_granted 2017 // l2cap_le_run() 2018 return 0; 2019 } 2020 2021 /** 2022 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 2023 * @param local_cid L2CAP LE Data Channel Identifier 2024 */ 2025 int l2cap_le_can_send_now(uint16_t local_cid){ 2026 // check if data can be sent via le at all 2027 return 0; 2028 } 2029 2030 /** 2031 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 2032 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 2033 * so packet handler should be ready to handle it 2034 * @param local_cid L2CAP LE Data Channel Identifier 2035 */ 2036 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 2037 // same as for non-le 2038 return 0; 2039 } 2040 2041 /** 2042 * @brief Send data via LE Data Channel 2043 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 2044 * @param local_cid L2CAP LE Data Channel Identifier 2045 * @param data data to send 2046 * @param size data size 2047 */ 2048 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 2049 2050 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2051 if (!channel) { 2052 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2053 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2054 } 2055 2056 if (len > channel->remote_mtu){ 2057 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 2058 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 2059 } 2060 2061 if (!hci_can_send_acl_packet_now(channel->con_handle)){ 2062 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 2063 return BTSTACK_ACL_BUFFERS_FULL; 2064 } 2065 2066 hci_reserve_packet_buffer(); 2067 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 2068 2069 memcpy(&acl_buffer[8], data, len); 2070 2071 return l2cap_send_prepared_connectionless(channel->con_handle, local_cid, len); 2072 } 2073 2074 /** 2075 * @brief Disconnect from LE Data Channel 2076 * @param local_cid L2CAP LE Data Channel Identifier 2077 */ 2078 uint8_t l2cap_le_disconnect(uint16_t local_cid) 2079 { 2080 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2081 if (!channel) { 2082 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2083 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2084 } 2085 2086 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2087 l2cap_run(); 2088 return 0; 2089 } 2090 2091 #endif 2092