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 static void l2cap_setup_header(uint8_t * acl_buffer, hci_con_handle_t con_handle, uint16_t remote_cid, uint16_t len){ 432 433 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 434 435 // 0 - Connection handle : PB=pb : BC=00 436 little_endian_store_16(acl_buffer, 0, con_handle | (pb << 12) | (0 << 14)); 437 // 2 - ACL length 438 little_endian_store_16(acl_buffer, 2, len + 4); 439 // 4 - L2CAP packet length 440 little_endian_store_16(acl_buffer, 4, len + 0); 441 // 6 - L2CAP channel DEST 442 little_endian_store_16(acl_buffer, 6, remote_cid); 443 } 444 445 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 446 447 if (!hci_is_packet_buffer_reserved()){ 448 log_error("l2cap_send_prepared called without reserving packet first"); 449 return BTSTACK_ACL_BUFFERS_FULL; 450 } 451 452 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 453 if (!channel) { 454 log_error("l2cap_send_prepared no channel for cid 0x%02x", local_cid); 455 return -1; // TODO: define error 456 } 457 458 if (!hci_can_send_prepared_acl_packet_now(channel->con_handle)){ 459 log_info("l2cap_send_prepared cid 0x%02x, cannot send", local_cid); 460 return BTSTACK_ACL_BUFFERS_FULL; 461 } 462 463 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used", local_cid, channel->con_handle); 464 465 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 466 l2cap_setup_header(acl_buffer, channel->con_handle, channel->remote_cid, len); 467 // send 468 return hci_send_acl_packet_buffer(len+8); 469 } 470 471 int l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len){ 472 473 if (!hci_is_packet_buffer_reserved()){ 474 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 475 return BTSTACK_ACL_BUFFERS_FULL; 476 } 477 478 if (!hci_can_send_prepared_acl_packet_now(con_handle)){ 479 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send", con_handle, cid); 480 return BTSTACK_ACL_BUFFERS_FULL; 481 } 482 483 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x", con_handle, cid); 484 485 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 486 l2cap_setup_header(acl_buffer, con_handle, cid, len); 487 // send 488 return hci_send_acl_packet_buffer(len+8); 489 } 490 491 int l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len){ 492 493 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 494 if (!channel) { 495 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 496 return -1; // TODO: define error 497 } 498 499 if (len > channel->remote_mtu){ 500 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 501 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 502 } 503 504 if (!hci_can_send_acl_packet_now(channel->con_handle)){ 505 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 506 return BTSTACK_ACL_BUFFERS_FULL; 507 } 508 509 hci_reserve_packet_buffer(); 510 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 511 512 memcpy(&acl_buffer[8], data, len); 513 514 return l2cap_send_prepared(local_cid, len); 515 } 516 517 int l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len){ 518 519 if (!hci_can_send_acl_packet_now(con_handle)){ 520 log_info("l2cap_send cid 0x%02x, cannot send", cid); 521 return BTSTACK_ACL_BUFFERS_FULL; 522 } 523 524 hci_reserve_packet_buffer(); 525 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 526 527 memcpy(&acl_buffer[8], data, len); 528 529 return l2cap_send_prepared_connectionless(con_handle, cid, len); 530 } 531 532 int l2cap_send_echo_request(hci_con_handle_t con_handle, uint8_t *data, uint16_t len){ 533 return l2cap_send_signaling_packet(con_handle, ECHO_REQUEST, 0x77, len, data); 534 } 535 536 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 537 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 538 } 539 540 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 541 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 542 } 543 544 545 546 // MARK: L2CAP_RUN 547 // process outstanding signaling tasks 548 static void l2cap_run(void){ 549 550 // log_info("l2cap_run: entered"); 551 552 // check pending signaling responses 553 while (signaling_responses_pending){ 554 555 hci_con_handle_t handle = signaling_responses[0].handle; 556 557 if (!hci_can_send_acl_packet_now(handle)) break; 558 559 uint8_t sig_id = signaling_responses[0].sig_id; 560 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 561 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 562 uint8_t response_code = signaling_responses[0].code; 563 564 // remove first item before sending (to avoid sending response mutliple times) 565 signaling_responses_pending--; 566 int i; 567 for (i=0; i < signaling_responses_pending; i++){ 568 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 569 } 570 571 switch (response_code){ 572 case CONNECTION_REQUEST: 573 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 574 // also disconnect if result is 0x0003 - security blocked 575 if (result == 0x0003){ 576 hci_disconnect_security_block(handle); 577 } 578 break; 579 case ECHO_REQUEST: 580 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 581 break; 582 case INFORMATION_REQUEST: 583 switch (infoType){ 584 case 1: { // Connectionless MTU 585 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 586 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 587 break; 588 } 589 case 2: { // Extended Features Supported 590 // extended features request supported, features: fixed channels, unicast connectionless data reception 591 uint32_t features = 0x280; 592 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 593 break; 594 } 595 case 3: { // Fixed Channels Supported 596 uint8_t map[8]; 597 memset(map, 0, 8); 598 map[0] = 0x06; // L2CAP Signaling Channel (0x02) + Connectionless reception (0x04) 599 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 600 break; 601 } 602 default: 603 // all other types are not supported 604 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 605 break; 606 } 607 break; 608 case COMMAND_REJECT: 609 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 610 #ifdef ENABLE_BLE 611 case COMMAND_REJECT_LE: 612 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 613 break; 614 #endif 615 default: 616 // should not happen 617 break; 618 } 619 } 620 621 uint8_t config_options[4]; 622 btstack_linked_list_iterator_t it; 623 btstack_linked_list_iterator_init(&it, &l2cap_channels); 624 while (btstack_linked_list_iterator_has_next(&it)){ 625 626 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 627 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 628 switch (channel->state){ 629 630 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 631 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 632 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 633 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 634 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 635 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 636 } 637 break; 638 639 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 640 if (!hci_can_send_command_packet_now()) break; 641 // send connection request - set state first 642 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 643 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 644 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 645 break; 646 647 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 648 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 649 channel->state = L2CAP_STATE_INVALID; 650 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 651 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 652 l2cap_stop_rtx(channel); 653 btstack_linked_list_iterator_remove(&it); 654 btstack_memory_l2cap_channel_free(channel); 655 break; 656 657 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 658 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 659 channel->state = L2CAP_STATE_CONFIG; 660 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 661 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 662 break; 663 664 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 665 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 666 // success, start l2cap handshake 667 channel->local_sig_id = l2cap_next_sig_id(); 668 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 669 l2cap_send_signaling_packet( channel->con_handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 670 l2cap_start_rtx(channel); 671 break; 672 673 case L2CAP_STATE_CONFIG: 674 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 675 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 676 uint16_t flags = 0; 677 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 678 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 679 flags = 1; 680 } else { 681 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 682 } 683 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 684 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 685 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 686 config_options[0] = 1; // MTU 687 config_options[1] = 2; // len param 688 little_endian_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 689 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 690 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 691 } else { 692 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 693 } 694 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 695 } 696 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 697 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 698 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 699 channel->local_sig_id = l2cap_next_sig_id(); 700 config_options[0] = 1; // MTU 701 config_options[1] = 2; // len param 702 little_endian_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 703 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 704 l2cap_start_rtx(channel); 705 } 706 if (l2cap_channel_ready_for_open(channel)){ 707 channel->state = L2CAP_STATE_OPEN; 708 l2cap_emit_channel_opened(channel, 0); // success 709 } 710 break; 711 712 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 713 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 714 channel->state = L2CAP_STATE_INVALID; 715 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 716 // 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 :) 717 l2cap_finialize_channel_close(channel); // -- remove from list 718 break; 719 720 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 721 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 722 channel->local_sig_id = l2cap_next_sig_id(); 723 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 724 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 725 break; 726 default: 727 break; 728 } 729 } 730 731 #ifdef ENABLE_BLE 732 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 733 while (btstack_linked_list_iterator_has_next(&it)){ 734 uint8_t * acl_buffer; 735 uint8_t * l2cap_payload; 736 uint16_t pos; 737 uint16_t payload_size; 738 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 739 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 740 switch (channel->state){ 741 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 742 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 743 channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; 744 // le psm, source cid, mtu, mps, initial credits 745 channel->local_sig_id = l2cap_next_sig_id(); 746 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); 747 break; 748 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 749 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 750 // TODO: support larger MPS 751 channel->state = L2CAP_STATE_OPEN; 752 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); 753 // notify client 754 l2cap_emit_channel_opened(channel, 0); 755 break; 756 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 757 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 758 channel->state = L2CAP_STATE_INVALID; 759 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); 760 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 761 l2cap_stop_rtx(channel); 762 btstack_linked_list_iterator_remove(&it); 763 btstack_memory_l2cap_channel_free(channel); 764 break; 765 case L2CAP_STATE_OPEN: 766 if (!channel->send_sdu_buffer) break; 767 if (!channel->credits_outgoing) break; 768 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 769 // send part of SDU 770 hci_reserve_packet_buffer(); 771 acl_buffer = hci_get_outgoing_packet_buffer(); 772 l2cap_payload = acl_buffer + 8; 773 pos = 0; 774 if (!channel->send_sdu_pos){ 775 // store SDU len 776 channel->send_sdu_pos += 2; 777 little_endian_store_16(l2cap_payload, pos, channel->send_sdu_len); 778 pos += 2; 779 } 780 payload_size = btstack_min(channel->send_sdu_len + 2 - channel->send_sdu_pos, channel->remote_mps - pos); 781 log_info("len %u, pos %u => payload %u", channel->send_sdu_len, channel->send_sdu_pos, payload_size); 782 memcpy(&l2cap_payload[pos], &channel->send_sdu_buffer[channel->send_sdu_pos-2], payload_size); // -2 for virtual SDU len 783 pos += payload_size; 784 channel->send_sdu_pos += payload_size; 785 l2cap_setup_header(acl_buffer, channel->con_handle, channel->remote_cid, payload_size); 786 // done 787 788 // channel->credits_outgoing--; 789 790 if (channel->send_sdu_pos >= channel->send_sdu_len + 2){ 791 channel->send_sdu_buffer = NULL; 792 // TODO: send done event 793 } 794 hci_send_acl_packet_buffer(8 + pos); 795 break; 796 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 797 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 798 channel->local_sig_id = l2cap_next_sig_id(); 799 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 800 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 801 break; 802 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 803 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 804 channel->state = L2CAP_STATE_INVALID; 805 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 806 l2cap_le_finialize_channel_close(channel); // -- remove from list 807 break; 808 default: 809 break; 810 } 811 } 812 813 // send l2cap con paramter update if necessary 814 hci_connections_get_iterator(&it); 815 while(btstack_linked_list_iterator_has_next(&it)){ 816 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 817 if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; 818 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 819 switch (connection->le_con_parameter_update_state){ 820 case CON_PARAMETER_UPDATE_SEND_REQUEST: 821 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 822 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, connection->le_con_param_update_identifier, 823 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 824 break; 825 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 826 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 827 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 828 break; 829 case CON_PARAMETER_UPDATE_DENY: 830 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 831 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 832 break; 833 default: 834 break; 835 } 836 #if 0 837 void l2cap_le_run(void){ 838 for all channels 839 switch(state): 840 841 if outgoing transfer active 842 send next chunk 843 if done, notify app 844 } 845 #endif 846 } 847 #endif 848 849 // log_info("l2cap_run: exit"); 850 } 851 852 uint16_t l2cap_max_mtu(void){ 853 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 854 } 855 856 uint16_t l2cap_max_le_mtu(void){ 857 return l2cap_max_mtu(); 858 } 859 860 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 861 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 862 log_info("l2cap_handle_connection_complete expected state"); 863 // success, start l2cap handshake 864 channel->con_handle = con_handle; 865 // check remote SSP feature first 866 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 867 } 868 } 869 870 #ifdef ENABLE_BLE 871 static void l2cap_handle_le_connection_complete(l2cap_channel_t * channel, uint8_t status, hci_con_handle_t con_handle){ 872 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 873 log_info("l2cap_le_handle_connection_complete expected state"); 874 // TODO: bail if status != 0 875 876 // success, start l2cap handshake 877 channel->con_handle = con_handle; 878 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 879 } 880 } 881 #endif 882 883 884 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 885 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 886 887 // we have been waiting for remote supported features, if both support SSP, 888 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)); 889 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 890 // request security level 2 891 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 892 gap_request_security_level(channel->con_handle, LEVEL_2); 893 return; 894 } 895 // fine, go ahead 896 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 897 } 898 899 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 900 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 901 902 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 903 if (!channel) { 904 return NULL; 905 } 906 907 // Init memory (make valgrind happy) 908 memset(channel, 0, sizeof(l2cap_channel_t)); 909 910 // fill in 911 channel->packet_handler = packet_handler; 912 bd_addr_copy(channel->address, address); 913 channel->address_type = address_type; 914 channel->psm = psm; 915 channel->local_mtu = local_mtu; 916 channel->remote_mtu = L2CAP_MINIMAL_MTU; 917 channel->required_security_level = security_level; 918 919 // 920 channel->local_cid = l2cap_next_local_cid(); 921 channel->con_handle = 0; 922 923 // set initial state 924 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 925 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 926 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 927 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 928 return channel; 929 } 930 931 /** 932 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 933 * @param packet_handler 934 * @param address 935 * @param psm 936 * @param mtu 937 * @param local_cid 938 */ 939 940 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){ 941 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, local_mtu); 942 943 if (local_mtu > l2cap_max_mtu()) { 944 local_mtu = l2cap_max_mtu(); 945 } 946 947 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 948 if (!channel) { 949 return BTSTACK_MEMORY_ALLOC_FAILED; 950 } 951 952 // add to connections list 953 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 954 955 // store local_cid 956 if (out_local_cid){ 957 *out_local_cid = channel->local_cid; 958 } 959 960 // check if hci connection is already usable 961 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 962 if (conn){ 963 log_info("l2cap_create_channel, hci connection already exists"); 964 l2cap_handle_connection_complete(conn->con_handle, channel); 965 // check if remote supported fearures are already received 966 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 967 l2cap_handle_remote_supported_features_received(channel); 968 } 969 } 970 971 l2cap_run(); 972 973 return 0; 974 } 975 976 void 977 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 978 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 979 // find channel for local_cid 980 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 981 if (channel) { 982 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 983 } 984 // process 985 l2cap_run(); 986 } 987 988 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 989 btstack_linked_list_iterator_t it; 990 btstack_linked_list_iterator_init(&it, &l2cap_channels); 991 while (btstack_linked_list_iterator_has_next(&it)){ 992 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 993 if ( bd_addr_cmp( channel->address, address) != 0) continue; 994 // channel for this address found 995 switch (channel->state){ 996 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 997 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 998 // failure, forward error code 999 l2cap_emit_channel_opened(channel, status); 1000 // discard channel 1001 l2cap_stop_rtx(channel); 1002 btstack_linked_list_iterator_remove(&it); 1003 btstack_memory_l2cap_channel_free(channel); 1004 break; 1005 default: 1006 break; 1007 } 1008 } 1009 } 1010 1011 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1012 btstack_linked_list_iterator_t it; 1013 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1014 while (btstack_linked_list_iterator_has_next(&it)){ 1015 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1016 if ( ! bd_addr_cmp( channel->address, address) ){ 1017 l2cap_handle_connection_complete(handle, channel); 1018 } 1019 } 1020 // process 1021 l2cap_run(); 1022 } 1023 1024 static void l2cap_notify_channel_can_send(void){ 1025 btstack_linked_list_iterator_t it; 1026 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1027 while (btstack_linked_list_iterator_has_next(&it)){ 1028 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1029 if (!channel->waiting_for_can_send_now) continue; 1030 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1031 channel->waiting_for_can_send_now = 0; 1032 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1033 } 1034 1035 int i; 1036 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1037 if (!fixed_channels[i].callback) continue; 1038 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1039 int can_send; 1040 if (l2cap_fixed_channel_table_index_is_le(i)){ 1041 can_send = hci_can_send_acl_le_packet_now(); 1042 } else { 1043 can_send = hci_can_send_acl_classic_packet_now(); 1044 } 1045 if (!can_send) continue; 1046 fixed_channels[i].waiting_for_can_send_now = 0; 1047 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1048 } 1049 } 1050 1051 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1052 1053 bd_addr_t address; 1054 hci_con_handle_t handle; 1055 btstack_linked_list_iterator_t it; 1056 int hci_con_used; 1057 1058 switch(hci_event_packet_get_type(packet)){ 1059 1060 // handle connection complete events 1061 case HCI_EVENT_CONNECTION_COMPLETE: 1062 reverse_bd_addr(&packet[5], address); 1063 if (packet[2] == 0){ 1064 handle = little_endian_read_16(packet, 3); 1065 l2cap_handle_connection_success_for_addr(address, handle); 1066 } else { 1067 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1068 } 1069 break; 1070 1071 // handle successful create connection cancel command 1072 case HCI_EVENT_COMMAND_COMPLETE: 1073 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1074 if (packet[5] == 0){ 1075 reverse_bd_addr(&packet[6], address); 1076 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1077 l2cap_handle_connection_failed_for_addr(address, 0x16); 1078 } 1079 } 1080 l2cap_run(); // try sending signaling packets first 1081 break; 1082 1083 case HCI_EVENT_COMMAND_STATUS: 1084 l2cap_run(); // try sending signaling packets first 1085 break; 1086 1087 // handle disconnection complete events 1088 case HCI_EVENT_DISCONNECTION_COMPLETE: 1089 // send l2cap disconnect events for all channels on this handle and free them 1090 handle = little_endian_read_16(packet, 3); 1091 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1092 while (btstack_linked_list_iterator_has_next(&it)){ 1093 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1094 if (channel->con_handle != handle) continue; 1095 l2cap_emit_channel_closed(channel); 1096 l2cap_stop_rtx(channel); 1097 btstack_linked_list_iterator_remove(&it); 1098 btstack_memory_l2cap_channel_free(channel); 1099 } 1100 #ifdef ENABLE_BLE 1101 btstack_linked_list_iterator_init(&it, &l2cap_le_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 l2cap_emit_channel_closed(channel); 1106 btstack_linked_list_iterator_remove(&it); 1107 btstack_memory_l2cap_channel_free(channel); 1108 } 1109 #endif 1110 break; 1111 1112 // Notify channel packet handler if they can send now 1113 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1114 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1115 l2cap_run(); // try sending signaling packets first 1116 l2cap_notify_channel_can_send(); 1117 break; 1118 1119 // HCI Connection Timeouts 1120 case L2CAP_EVENT_TIMEOUT_CHECK: 1121 handle = little_endian_read_16(packet, 2); 1122 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1123 if (hci_authentication_active_for_handle(handle)) break; 1124 hci_con_used = 0; 1125 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1126 while (btstack_linked_list_iterator_has_next(&it)){ 1127 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1128 if (channel->con_handle != handle) continue; 1129 hci_con_used = 1; 1130 break; 1131 } 1132 if (hci_con_used) break; 1133 if (!hci_can_send_command_packet_now()) break; 1134 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1135 break; 1136 1137 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1138 handle = little_endian_read_16(packet, 3); 1139 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1140 while (btstack_linked_list_iterator_has_next(&it)){ 1141 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1142 if (channel->con_handle != handle) continue; 1143 l2cap_handle_remote_supported_features_received(channel); 1144 break; 1145 } 1146 break; 1147 1148 #ifdef ENABLE_BLE 1149 case HCI_EVENT_LE_META: 1150 switch (packet[2]){ 1151 int addr_type; 1152 l2cap_channel_t * channel; 1153 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 1154 // Connection management 1155 reverse_bd_addr(&packet[8], address); 1156 addr_type = (bd_addr_type_t)packet[7]; 1157 log_info("L2CAP - LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(address)); 1158 // get l2cap_channel 1159 // also pass in status 1160 channel = l2cap_get_le_channel_for_address_and_addr_type(address, addr_type); 1161 if (!channel) break; 1162 l2cap_handle_le_connection_complete(channel, packet[3], little_endian_read_16(packet, 4)); 1163 break; 1164 default: 1165 break; 1166 } 1167 break; 1168 #endif 1169 1170 case GAP_EVENT_SECURITY_LEVEL: 1171 handle = little_endian_read_16(packet, 2); 1172 log_info("l2cap - security level update"); 1173 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1174 while (btstack_linked_list_iterator_has_next(&it)){ 1175 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1176 if (channel->con_handle != handle) continue; 1177 1178 log_info("l2cap - state %u", channel->state); 1179 1180 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1181 gap_security_level_t required_level = channel->required_security_level; 1182 1183 switch (channel->state){ 1184 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1185 if (actual_level >= required_level){ 1186 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1187 l2cap_emit_connection_request(channel); 1188 } else { 1189 channel->reason = 0x0003; // security block 1190 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1191 } 1192 break; 1193 1194 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1195 if (actual_level >= required_level){ 1196 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1197 } else { 1198 // disconnnect, authentication not good enough 1199 hci_disconnect_security_block(handle); 1200 } 1201 break; 1202 1203 default: 1204 break; 1205 } 1206 } 1207 break; 1208 1209 default: 1210 break; 1211 } 1212 1213 l2cap_run(); 1214 } 1215 1216 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1217 channel->remote_sig_id = identifier; 1218 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1219 l2cap_run(); 1220 } 1221 1222 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 1223 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1224 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1225 signaling_responses[signaling_responses_pending].handle = handle; 1226 signaling_responses[signaling_responses_pending].code = code; 1227 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1228 signaling_responses[signaling_responses_pending].data = data; 1229 signaling_responses_pending++; 1230 l2cap_run(); 1231 } 1232 } 1233 1234 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1235 1236 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1237 l2cap_service_t *service = l2cap_get_service(psm); 1238 if (!service) { 1239 // 0x0002 PSM not supported 1240 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 1241 return; 1242 } 1243 1244 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1245 if (!hci_connection) { 1246 // 1247 log_error("no hci_connection for handle %u", handle); 1248 return; 1249 } 1250 1251 // alloc structure 1252 // log_info("l2cap_handle_connection_request register channel"); 1253 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 1254 psm, service->mtu, service->required_security_level); 1255 if (!channel){ 1256 // 0x0004 No resources available 1257 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 1258 return; 1259 } 1260 1261 channel->con_handle = handle; 1262 channel->remote_cid = source_cid; 1263 channel->remote_sig_id = sig_id; 1264 1265 // limit local mtu to max acl packet length - l2cap header 1266 if (channel->local_mtu > l2cap_max_mtu()) { 1267 channel->local_mtu = l2cap_max_mtu(); 1268 } 1269 1270 // set initial state 1271 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1272 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 1273 1274 // add to connections list 1275 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1276 1277 // assert security requirements 1278 gap_request_security_level(handle, channel->required_security_level); 1279 } 1280 1281 void l2cap_accept_connection(uint16_t local_cid){ 1282 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1283 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1284 if (!channel) { 1285 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1286 return; 1287 } 1288 1289 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1290 1291 // process 1292 l2cap_run(); 1293 } 1294 1295 void l2cap_decline_connection(uint16_t local_cid){ 1296 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 1297 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1298 if (!channel) { 1299 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1300 return; 1301 } 1302 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1303 channel->reason = 0x04; // no resources available 1304 l2cap_run(); 1305 } 1306 1307 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1308 1309 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1310 1311 uint16_t flags = little_endian_read_16(command, 6); 1312 if (flags & 1) { 1313 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1314 } 1315 1316 // accept the other's configuration options 1317 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1318 uint16_t pos = 8; 1319 while (pos < end_pos){ 1320 uint8_t option_hint = command[pos] >> 7; 1321 uint8_t option_type = command[pos] & 0x7f; 1322 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1323 pos++; 1324 uint8_t length = command[pos++]; 1325 // MTU { type(8): 1, len(8):2, MTU(16) } 1326 if (option_type == 1 && length == 2){ 1327 channel->remote_mtu = little_endian_read_16(command, pos); 1328 // log_info("l2cap cid 0x%02x, remote mtu %u", channel->local_cid, channel->remote_mtu); 1329 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1330 } 1331 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1332 if (option_type == 2 && length == 2){ 1333 channel->flush_timeout = little_endian_read_16(command, pos); 1334 } 1335 // check for unknown options 1336 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1337 log_info("l2cap cid %u, unknown options", channel->local_cid); 1338 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1339 } 1340 pos += length; 1341 } 1342 } 1343 1344 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1345 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1346 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1347 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1348 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 1349 if (channel->state == L2CAP_STATE_OPEN) return 0; 1350 return 1; 1351 } 1352 1353 1354 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1355 1356 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1357 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1358 uint16_t result = 0; 1359 1360 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1361 1362 // handle DISCONNECT REQUESTS seperately 1363 if (code == DISCONNECTION_REQUEST){ 1364 switch (channel->state){ 1365 case L2CAP_STATE_CONFIG: 1366 case L2CAP_STATE_OPEN: 1367 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1368 case L2CAP_STATE_WAIT_DISCONNECT: 1369 l2cap_handle_disconnect_request(channel, identifier); 1370 break; 1371 1372 default: 1373 // ignore in other states 1374 break; 1375 } 1376 return; 1377 } 1378 1379 // @STATEMACHINE(l2cap) 1380 switch (channel->state) { 1381 1382 case L2CAP_STATE_WAIT_CONNECT_RSP: 1383 switch (code){ 1384 case CONNECTION_RESPONSE: 1385 l2cap_stop_rtx(channel); 1386 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1387 switch (result) { 1388 case 0: 1389 // successful connection 1390 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1391 channel->state = L2CAP_STATE_CONFIG; 1392 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1393 break; 1394 case 1: 1395 // connection pending. get some coffee, but start the ERTX 1396 l2cap_start_ertx(channel); 1397 break; 1398 default: 1399 // channel closed 1400 channel->state = L2CAP_STATE_CLOSED; 1401 // map l2cap connection response result to BTstack status enumeration 1402 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1403 1404 // drop link key if security block 1405 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1406 gap_drop_link_key_for_bd_addr(channel->address); 1407 } 1408 1409 // discard channel 1410 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1411 btstack_memory_l2cap_channel_free(channel); 1412 break; 1413 } 1414 break; 1415 1416 default: 1417 //@TODO: implement other signaling packets 1418 break; 1419 } 1420 break; 1421 1422 case L2CAP_STATE_CONFIG: 1423 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1424 switch (code) { 1425 case CONFIGURE_REQUEST: 1426 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1427 l2cap_signaling_handle_configure_request(channel, command); 1428 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1429 // only done if continuation not set 1430 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1431 } 1432 break; 1433 case CONFIGURE_RESPONSE: 1434 l2cap_stop_rtx(channel); 1435 switch (result){ 1436 case 0: // success 1437 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1438 break; 1439 case 4: // pending 1440 l2cap_start_ertx(channel); 1441 break; 1442 default: 1443 // retry on negative result 1444 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1445 break; 1446 } 1447 break; 1448 default: 1449 break; 1450 } 1451 if (l2cap_channel_ready_for_open(channel)){ 1452 // for open: 1453 channel->state = L2CAP_STATE_OPEN; 1454 l2cap_emit_channel_opened(channel, 0); 1455 } 1456 break; 1457 1458 case L2CAP_STATE_WAIT_DISCONNECT: 1459 switch (code) { 1460 case DISCONNECTION_RESPONSE: 1461 l2cap_finialize_channel_close(channel); 1462 break; 1463 default: 1464 //@TODO: implement other signaling packets 1465 break; 1466 } 1467 break; 1468 1469 case L2CAP_STATE_CLOSED: 1470 // @TODO handle incoming requests 1471 break; 1472 1473 case L2CAP_STATE_OPEN: 1474 //@TODO: implement other signaling packets, e.g. re-configure 1475 break; 1476 default: 1477 break; 1478 } 1479 // log_info("new state %u", channel->state); 1480 } 1481 1482 1483 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1484 1485 // get code, signalind identifier and command len 1486 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1487 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1488 1489 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1490 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1491 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1492 return; 1493 } 1494 1495 // general commands without an assigned channel 1496 switch(code) { 1497 1498 case CONNECTION_REQUEST: { 1499 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1500 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1501 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1502 return; 1503 } 1504 1505 case ECHO_REQUEST: 1506 l2cap_register_signaling_response(handle, code, sig_id, 0); 1507 return; 1508 1509 case INFORMATION_REQUEST: { 1510 uint16_t infoType = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1511 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1512 return; 1513 } 1514 1515 default: 1516 break; 1517 } 1518 1519 1520 // Get potential destination CID 1521 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1522 1523 // Find channel for this sig_id and connection handle 1524 btstack_linked_list_iterator_t it; 1525 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1526 while (btstack_linked_list_iterator_has_next(&it)){ 1527 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1528 if (channel->con_handle != handle) continue; 1529 if (code & 1) { 1530 // match odd commands (responses) by previous signaling identifier 1531 if (channel->local_sig_id == sig_id) { 1532 l2cap_signaling_handler_channel(channel, command); 1533 break; 1534 } 1535 } else { 1536 // match even commands (requests) by local channel id 1537 if (channel->local_cid == dest_cid) { 1538 l2cap_signaling_handler_channel(channel, command); 1539 break; 1540 } 1541 } 1542 } 1543 } 1544 1545 #ifdef ENABLE_BLE 1546 // @returns valid 1547 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 1548 hci_connection_t * connection; 1549 uint16_t result; 1550 uint8_t event[10]; 1551 uint16_t le_psm; 1552 uint16_t local_cid; 1553 l2cap_service_t * service; 1554 l2cap_channel_t * channel; 1555 btstack_linked_list_iterator_t it; 1556 1557 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1558 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 1559 1560 switch (code){ 1561 1562 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 1563 result = little_endian_read_16(command, 4); 1564 l2cap_emit_connection_parameter_update_response(handle, result); 1565 break; 1566 1567 case CONNECTION_PARAMETER_UPDATE_REQUEST: 1568 connection = hci_connection_for_handle(handle); 1569 if (connection){ 1570 if (connection->role != HCI_ROLE_MASTER){ 1571 // reject command without notifying upper layer when not in master role 1572 return 0; 1573 } 1574 int update_parameter = 1; 1575 le_connection_parameter_range_t existing_range; 1576 gap_get_connection_parameter_range(&existing_range); 1577 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 1578 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 1579 uint16_t le_conn_latency = little_endian_read_16(command,12); 1580 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 1581 1582 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 1583 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 1584 1585 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 1586 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 1587 1588 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 1589 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 1590 1591 if (update_parameter){ 1592 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 1593 connection->le_conn_interval_min = le_conn_interval_min; 1594 connection->le_conn_interval_max = le_conn_interval_max; 1595 connection->le_conn_latency = le_conn_latency; 1596 connection->le_supervision_timeout = le_supervision_timeout; 1597 } else { 1598 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 1599 } 1600 connection->le_con_param_update_identifier = sig_id; 1601 } 1602 1603 if (!l2cap_event_packet_handler) break; 1604 1605 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 1606 event[1] = 8; 1607 memcpy(&event[2], &command[4], 8); 1608 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1609 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1610 break; 1611 1612 case LE_CREDIT_BASED_CONNECTION_REQUEST: 1613 1614 // get hci connection, bail if not found (must not happen) 1615 connection = hci_connection_for_handle(handle); 1616 if (!connection) return 0; 1617 1618 // check if service registered 1619 le_psm = little_endian_read_16(command, 4); 1620 service = l2cap_le_get_service(le_psm); 1621 1622 if (service){ 1623 1624 uint16_t source_cid = little_endian_read_16(command, 6); 1625 if (source_cid < 0x40){ 1626 // 0x0009 Connection refused - Invalid Source CID 1627 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0009); 1628 return 1; 1629 } 1630 1631 // go through list of channels for this ACL connection and check if we get a match 1632 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1633 while (btstack_linked_list_iterator_has_next(&it)){ 1634 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1635 if (a_channel->con_handle != handle) continue; 1636 if (a_channel->remote_cid != source_cid) continue; 1637 // 0x000a Connection refused - Source CID already allocated 1638 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x000a); 1639 return 1; 1640 } 1641 1642 // TODO: deal with authentication requirements, errors 0x005 - 000x8 1643 1644 // allocate channel 1645 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 1646 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 1647 if (!channel){ 1648 // 0x0004 Connection refused – no resources available 1649 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0004); 1650 return 1; 1651 } 1652 1653 channel->con_handle = handle; 1654 channel->remote_cid = source_cid; 1655 channel->remote_sig_id = sig_id; 1656 channel->remote_mtu = little_endian_read_16(command, 8); 1657 channel->remote_mps = little_endian_read_16(command, 10); 1658 channel->credits_outgoing = little_endian_read_16(command, 12); 1659 1660 // set initial state 1661 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1662 1663 // add to connections list 1664 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1665 1666 // post connection request event 1667 l2cap_emit_connection_request(channel); 1668 1669 } else { 1670 // Connection refused – LE_PSM not supported 1671 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0002); 1672 } 1673 break; 1674 1675 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 1676 // Find channel for this sig_id and connection handle 1677 channel = NULL; 1678 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1679 while (btstack_linked_list_iterator_has_next(&it)){ 1680 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1681 if (a_channel->con_handle != handle) continue; 1682 if (a_channel->local_sig_id != sig_id) continue; 1683 channel = a_channel; 1684 break; 1685 } 1686 // TODO: send error 1687 if (!channel) break; 1688 1689 // cid + 0 1690 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 1691 if (result){ 1692 channel->state = L2CAP_STATE_CLOSED; 1693 // map l2cap connection response result to BTstack status enumeration 1694 l2cap_emit_channel_opened(channel, result); 1695 1696 // discard channel 1697 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1698 btstack_memory_l2cap_channel_free(channel); 1699 break; 1700 } 1701 1702 // success 1703 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1704 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1705 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 1706 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 1707 channel->state = L2CAP_STATE_OPEN; 1708 l2cap_emit_channel_opened(channel, result); 1709 break; 1710 1711 case DISCONNECTION_REQUEST: 1712 // find channel 1713 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1714 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1715 if (!channel) break; 1716 channel->remote_sig_id = sig_id; 1717 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1718 break; 1719 1720 default: 1721 // command unknown -> reject command 1722 return 0; 1723 } 1724 return 1; 1725 } 1726 #endif 1727 1728 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 1729 1730 // Get Channel ID 1731 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1732 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1733 1734 switch (channel_id) { 1735 1736 case L2CAP_CID_SIGNALING: { 1737 uint16_t command_offset = 8; 1738 while (command_offset < size) { 1739 // handle signaling commands 1740 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1741 1742 // increment command_offset 1743 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1744 } 1745 break; 1746 } 1747 1748 #ifdef ENABLE_BLE 1749 case L2CAP_CID_SIGNALING_LE: { 1750 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1751 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 1752 if (!valid){ 1753 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1754 } 1755 break; 1756 } 1757 #endif 1758 1759 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1760 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 1761 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1762 } 1763 break; 1764 1765 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1766 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 1767 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1768 } 1769 break; 1770 1771 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 1772 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 1773 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1774 } 1775 break; 1776 1777 default: { 1778 // Find channel for this channel_id and connection handle 1779 l2cap_channel_t * l2cap_channel; 1780 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 1781 if (l2cap_channel) { 1782 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1783 } 1784 #ifdef ENABLE_BLE 1785 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 1786 if (l2cap_channel) { 1787 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1788 } 1789 #endif 1790 break; 1791 } 1792 } 1793 1794 l2cap_run(); 1795 } 1796 1797 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1798 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 1799 channel->state = L2CAP_STATE_CLOSED; 1800 l2cap_emit_channel_closed(channel); 1801 // discard channel 1802 l2cap_stop_rtx(channel); 1803 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1804 btstack_memory_l2cap_channel_free(channel); 1805 } 1806 1807 #ifdef ENABLE_BLE 1808 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1809 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 1810 channel->state = L2CAP_STATE_CLOSED; 1811 l2cap_emit_channel_closed(channel); 1812 // discard channel 1813 l2cap_stop_rtx(channel); 1814 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1815 btstack_memory_l2cap_channel_free(channel); 1816 } 1817 #endif 1818 1819 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 1820 btstack_linked_list_iterator_t it; 1821 btstack_linked_list_iterator_init(&it, services); 1822 while (btstack_linked_list_iterator_has_next(&it)){ 1823 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 1824 if ( service->psm == psm){ 1825 return service; 1826 }; 1827 } 1828 return NULL; 1829 } 1830 1831 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 1832 return l2cap_get_service_internal(&l2cap_services, psm); 1833 } 1834 1835 1836 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 1837 1838 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1839 1840 // check for alread registered psm 1841 l2cap_service_t *service = l2cap_get_service(psm); 1842 if (service) { 1843 log_error("l2cap_register_service: PSM %u already registered", psm); 1844 return L2CAP_SERVICE_ALREADY_REGISTERED; 1845 } 1846 1847 // alloc structure 1848 service = btstack_memory_l2cap_service_get(); 1849 if (!service) { 1850 log_error("l2cap_register_service: no memory for l2cap_service_t"); 1851 return BTSTACK_MEMORY_ALLOC_FAILED; 1852 } 1853 1854 // fill in 1855 service->psm = psm; 1856 service->mtu = mtu; 1857 service->packet_handler = service_packet_handler; 1858 service->required_security_level = security_level; 1859 1860 // add to services list 1861 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 1862 1863 // enable page scan 1864 gap_connectable_control(1); 1865 1866 return 0; 1867 } 1868 1869 uint8_t l2cap_unregister_service(uint16_t psm){ 1870 1871 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1872 1873 l2cap_service_t *service = l2cap_get_service(psm); 1874 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 1875 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 1876 btstack_memory_l2cap_service_free(service); 1877 1878 // disable page scan when no services registered 1879 if (btstack_linked_list_empty(&l2cap_services)) { 1880 gap_connectable_control(0); 1881 } 1882 return 0; 1883 } 1884 1885 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1886 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 1887 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 1888 if (index < 0) return; 1889 fixed_channels[index].callback = the_packet_handler; 1890 } 1891 1892 #ifdef ENABLE_BLE 1893 1894 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 1895 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 1896 } 1897 1898 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 1899 1900 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 1901 1902 // check for alread registered psm 1903 l2cap_service_t *service = l2cap_le_get_service(psm); 1904 if (service) { 1905 return L2CAP_SERVICE_ALREADY_REGISTERED; 1906 } 1907 1908 // alloc structure 1909 service = btstack_memory_l2cap_service_get(); 1910 if (!service) { 1911 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 1912 return BTSTACK_MEMORY_ALLOC_FAILED; 1913 } 1914 1915 // fill in 1916 service->psm = psm; 1917 service->mtu = 0; 1918 service->packet_handler = packet_handler; 1919 service->required_security_level = security_level; 1920 1921 // add to services list 1922 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 1923 1924 // done 1925 return 0; 1926 } 1927 1928 uint8_t l2cap_le_unregister_service(uint16_t psm) { 1929 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 1930 l2cap_service_t *service = l2cap_le_get_service(psm); 1931 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 1932 1933 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 1934 btstack_memory_l2cap_service_free(service); 1935 return 0; 1936 } 1937 1938 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 1939 // get channel 1940 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 1941 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 1942 1943 // validate state 1944 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 1945 return ERROR_CODE_COMMAND_DISALLOWED; 1946 } 1947 1948 // set state accept connection 1949 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 1950 channel->receive_sdu_buffer = receive_sdu_buffer; 1951 channel->local_mtu = mtu; 1952 channel->credits_incoming = initial_credits; 1953 1954 // go 1955 l2cap_run(); 1956 return 0; 1957 } 1958 1959 /** 1960 * @brief Deny incoming LE Data Channel connection due to resource constraints 1961 * @param local_cid L2CAP LE Data Channel Identifier 1962 */ 1963 1964 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 1965 // get channel 1966 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 1967 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 1968 1969 // validate state 1970 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 1971 return ERROR_CODE_COMMAND_DISALLOWED; 1972 } 1973 1974 // set state decline connection 1975 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 1976 channel->reason = 0x04; // no resources available 1977 l2cap_run(); 1978 return 0; 1979 } 1980 1981 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 1982 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 1983 uint16_t * out_local_cid) { 1984 1985 log_info("L2CAP_LE_CREATE_CHANNEL addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 1986 1987 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, address, address_type, psm, mtu, LEVEL_0); 1988 if (!channel) { 1989 return BTSTACK_MEMORY_ALLOC_FAILED; 1990 } 1991 log_info("l2cap_le_create_channel %p", channel); 1992 1993 // store local_cid 1994 if (out_local_cid){ 1995 *out_local_cid = channel->local_cid; 1996 } 1997 1998 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 1999 2000 // add to connections list 2001 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2002 2003 // check if hci connection is already usable 2004 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, address_type); 2005 2006 if (conn){ 2007 log_info("l2cap_le_create_channel, hci connection already exists"); 2008 l2cap_handle_le_connection_complete(channel, 0, conn->con_handle); 2009 } else { 2010 2011 // 2012 // TODO: start timer 2013 // .. 2014 2015 // start connection 2016 uint8_t res = gap_auto_connection_start(address_type, address); 2017 if (res){ 2018 // discard channel object 2019 log_info("gap_auto_connection_start failed! 0x%02x", res); 2020 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2021 btstack_memory_l2cap_channel_free(channel); 2022 return res; 2023 } 2024 } 2025 return 0; 2026 } 2027 2028 /** 2029 * @brief Provide credtis for LE Data Channel 2030 * @param local_cid L2CAP LE Data Channel Identifier 2031 * @param credits Number additional credits for peer 2032 */ 2033 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 2034 // get channel 2035 // bail if missing 2036 // check state 2037 // check incoming credits + credits <= 0xffff 2038 // set credits_granted 2039 // l2cap_le_run() 2040 return 0; 2041 } 2042 2043 /** 2044 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 2045 * @param local_cid L2CAP LE Data Channel Identifier 2046 */ 2047 int l2cap_le_can_send_now(uint16_t local_cid){ 2048 // check if data can be sent via le at all 2049 return 0; 2050 } 2051 2052 /** 2053 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 2054 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 2055 * so packet handler should be ready to handle it 2056 * @param local_cid L2CAP LE Data Channel Identifier 2057 */ 2058 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 2059 // same as for non-le 2060 return 0; 2061 } 2062 2063 /** 2064 * @brief Send data via LE Data Channel 2065 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 2066 * @param local_cid L2CAP LE Data Channel Identifier 2067 * @param data data to send 2068 * @param size data size 2069 */ 2070 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 2071 2072 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2073 if (!channel) { 2074 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2075 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2076 } 2077 2078 if (len > channel->remote_mtu){ 2079 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 2080 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 2081 } 2082 2083 if (channel->send_sdu_buffer){ 2084 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 2085 return BTSTACK_ACL_BUFFERS_FULL; 2086 } 2087 2088 channel->send_sdu_buffer = data; 2089 channel->send_sdu_len = len; 2090 channel->send_sdu_pos = 0; 2091 2092 l2cap_run(); 2093 return 0; 2094 } 2095 2096 /** 2097 * @brief Disconnect from LE Data Channel 2098 * @param local_cid L2CAP LE Data Channel Identifier 2099 */ 2100 uint8_t l2cap_le_disconnect(uint16_t local_cid) 2101 { 2102 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2103 if (!channel) { 2104 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2105 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2106 } 2107 2108 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2109 l2cap_run(); 2110 return 0; 2111 } 2112 2113 #endif 2114