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, channel->local_mtu, 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 // TODO: enable credit counting 789 // channel->credits_outgoing--; 790 791 if (channel->send_sdu_pos >= channel->send_sdu_len + 2){ 792 channel->send_sdu_buffer = NULL; 793 // TODO: send done event 794 } 795 hci_send_acl_packet_buffer(8 + pos); 796 break; 797 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 798 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 799 channel->local_sig_id = l2cap_next_sig_id(); 800 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 801 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 802 break; 803 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 804 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 805 channel->state = L2CAP_STATE_INVALID; 806 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 807 l2cap_le_finialize_channel_close(channel); // -- remove from list 808 break; 809 default: 810 break; 811 } 812 } 813 814 // send l2cap con paramter update if necessary 815 hci_connections_get_iterator(&it); 816 while(btstack_linked_list_iterator_has_next(&it)){ 817 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 818 if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; 819 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 820 switch (connection->le_con_parameter_update_state){ 821 case CON_PARAMETER_UPDATE_SEND_REQUEST: 822 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 823 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, connection->le_con_param_update_identifier, 824 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 825 break; 826 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 827 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 828 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 829 break; 830 case CON_PARAMETER_UPDATE_DENY: 831 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 832 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 833 break; 834 default: 835 break; 836 } 837 } 838 #endif 839 840 // log_info("l2cap_run: exit"); 841 } 842 843 uint16_t l2cap_max_mtu(void){ 844 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 845 } 846 847 uint16_t l2cap_max_le_mtu(void){ 848 return l2cap_max_mtu(); 849 } 850 851 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 852 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 853 log_info("l2cap_handle_connection_complete expected state"); 854 // success, start l2cap handshake 855 channel->con_handle = con_handle; 856 // check remote SSP feature first 857 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 858 } 859 } 860 861 #ifdef ENABLE_BLE 862 static void l2cap_handle_le_connection_complete(l2cap_channel_t * channel, uint8_t status, hci_con_handle_t con_handle){ 863 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 864 log_info("l2cap_le_handle_connection_complete expected state"); 865 // TODO: bail if status != 0 866 867 // success, start l2cap handshake 868 channel->con_handle = con_handle; 869 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 870 } 871 } 872 #endif 873 874 875 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 876 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 877 878 // we have been waiting for remote supported features, if both support SSP, 879 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)); 880 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 881 // request security level 2 882 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 883 gap_request_security_level(channel->con_handle, LEVEL_2); 884 return; 885 } 886 // fine, go ahead 887 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 888 } 889 890 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 891 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 892 893 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 894 if (!channel) { 895 return NULL; 896 } 897 898 // Init memory (make valgrind happy) 899 memset(channel, 0, sizeof(l2cap_channel_t)); 900 901 // fill in 902 channel->packet_handler = packet_handler; 903 bd_addr_copy(channel->address, address); 904 channel->address_type = address_type; 905 channel->psm = psm; 906 channel->local_mtu = local_mtu; 907 channel->remote_mtu = L2CAP_MINIMAL_MTU; 908 channel->required_security_level = security_level; 909 910 // 911 channel->local_cid = l2cap_next_local_cid(); 912 channel->con_handle = 0; 913 914 // set initial state 915 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 916 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 917 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 918 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 919 return channel; 920 } 921 922 /** 923 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 924 * @param packet_handler 925 * @param address 926 * @param psm 927 * @param mtu 928 * @param local_cid 929 */ 930 931 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){ 932 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, local_mtu); 933 934 if (local_mtu > l2cap_max_mtu()) { 935 local_mtu = l2cap_max_mtu(); 936 } 937 938 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 939 if (!channel) { 940 return BTSTACK_MEMORY_ALLOC_FAILED; 941 } 942 943 // add to connections list 944 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 945 946 // store local_cid 947 if (out_local_cid){ 948 *out_local_cid = channel->local_cid; 949 } 950 951 // check if hci connection is already usable 952 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 953 if (conn){ 954 log_info("l2cap_create_channel, hci connection already exists"); 955 l2cap_handle_connection_complete(conn->con_handle, channel); 956 // check if remote supported fearures are already received 957 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 958 l2cap_handle_remote_supported_features_received(channel); 959 } 960 } 961 962 l2cap_run(); 963 964 return 0; 965 } 966 967 void 968 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 969 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 970 // find channel for local_cid 971 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 972 if (channel) { 973 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 974 } 975 // process 976 l2cap_run(); 977 } 978 979 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 980 btstack_linked_list_iterator_t it; 981 btstack_linked_list_iterator_init(&it, &l2cap_channels); 982 while (btstack_linked_list_iterator_has_next(&it)){ 983 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 984 if ( bd_addr_cmp( channel->address, address) != 0) continue; 985 // channel for this address found 986 switch (channel->state){ 987 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 988 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 989 // failure, forward error code 990 l2cap_emit_channel_opened(channel, status); 991 // discard channel 992 l2cap_stop_rtx(channel); 993 btstack_linked_list_iterator_remove(&it); 994 btstack_memory_l2cap_channel_free(channel); 995 break; 996 default: 997 break; 998 } 999 } 1000 } 1001 1002 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1003 btstack_linked_list_iterator_t it; 1004 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1005 while (btstack_linked_list_iterator_has_next(&it)){ 1006 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1007 if ( ! bd_addr_cmp( channel->address, address) ){ 1008 l2cap_handle_connection_complete(handle, channel); 1009 } 1010 } 1011 // process 1012 l2cap_run(); 1013 } 1014 1015 static void l2cap_notify_channel_can_send(void){ 1016 btstack_linked_list_iterator_t it; 1017 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1018 while (btstack_linked_list_iterator_has_next(&it)){ 1019 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1020 if (!channel->waiting_for_can_send_now) continue; 1021 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1022 channel->waiting_for_can_send_now = 0; 1023 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1024 } 1025 1026 int i; 1027 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1028 if (!fixed_channels[i].callback) continue; 1029 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1030 int can_send; 1031 if (l2cap_fixed_channel_table_index_is_le(i)){ 1032 can_send = hci_can_send_acl_le_packet_now(); 1033 } else { 1034 can_send = hci_can_send_acl_classic_packet_now(); 1035 } 1036 if (!can_send) continue; 1037 fixed_channels[i].waiting_for_can_send_now = 0; 1038 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1039 } 1040 } 1041 1042 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1043 1044 bd_addr_t address; 1045 hci_con_handle_t handle; 1046 btstack_linked_list_iterator_t it; 1047 int hci_con_used; 1048 1049 switch(hci_event_packet_get_type(packet)){ 1050 1051 // handle connection complete events 1052 case HCI_EVENT_CONNECTION_COMPLETE: 1053 reverse_bd_addr(&packet[5], address); 1054 if (packet[2] == 0){ 1055 handle = little_endian_read_16(packet, 3); 1056 l2cap_handle_connection_success_for_addr(address, handle); 1057 } else { 1058 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1059 } 1060 break; 1061 1062 // handle successful create connection cancel command 1063 case HCI_EVENT_COMMAND_COMPLETE: 1064 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1065 if (packet[5] == 0){ 1066 reverse_bd_addr(&packet[6], address); 1067 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1068 l2cap_handle_connection_failed_for_addr(address, 0x16); 1069 } 1070 } 1071 l2cap_run(); // try sending signaling packets first 1072 break; 1073 1074 case HCI_EVENT_COMMAND_STATUS: 1075 l2cap_run(); // try sending signaling packets first 1076 break; 1077 1078 // handle disconnection complete events 1079 case HCI_EVENT_DISCONNECTION_COMPLETE: 1080 // send l2cap disconnect events for all channels on this handle and free them 1081 handle = little_endian_read_16(packet, 3); 1082 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1083 while (btstack_linked_list_iterator_has_next(&it)){ 1084 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1085 if (channel->con_handle != handle) continue; 1086 l2cap_emit_channel_closed(channel); 1087 l2cap_stop_rtx(channel); 1088 btstack_linked_list_iterator_remove(&it); 1089 btstack_memory_l2cap_channel_free(channel); 1090 } 1091 #ifdef ENABLE_BLE 1092 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1093 while (btstack_linked_list_iterator_has_next(&it)){ 1094 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1095 if (channel->con_handle != handle) continue; 1096 l2cap_emit_channel_closed(channel); 1097 btstack_linked_list_iterator_remove(&it); 1098 btstack_memory_l2cap_channel_free(channel); 1099 } 1100 #endif 1101 break; 1102 1103 // Notify channel packet handler if they can send now 1104 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1105 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1106 l2cap_run(); // try sending signaling packets first 1107 l2cap_notify_channel_can_send(); 1108 break; 1109 1110 // HCI Connection Timeouts 1111 case L2CAP_EVENT_TIMEOUT_CHECK: 1112 handle = little_endian_read_16(packet, 2); 1113 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1114 if (hci_authentication_active_for_handle(handle)) break; 1115 hci_con_used = 0; 1116 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1117 while (btstack_linked_list_iterator_has_next(&it)){ 1118 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1119 if (channel->con_handle != handle) continue; 1120 hci_con_used = 1; 1121 break; 1122 } 1123 if (hci_con_used) break; 1124 if (!hci_can_send_command_packet_now()) break; 1125 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1126 break; 1127 1128 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1129 handle = little_endian_read_16(packet, 3); 1130 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1131 while (btstack_linked_list_iterator_has_next(&it)){ 1132 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1133 if (channel->con_handle != handle) continue; 1134 l2cap_handle_remote_supported_features_received(channel); 1135 break; 1136 } 1137 break; 1138 1139 #ifdef ENABLE_BLE 1140 case HCI_EVENT_LE_META: 1141 switch (packet[2]){ 1142 int addr_type; 1143 l2cap_channel_t * channel; 1144 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 1145 // Connection management 1146 reverse_bd_addr(&packet[8], address); 1147 addr_type = (bd_addr_type_t)packet[7]; 1148 log_info("L2CAP - LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(address)); 1149 // get l2cap_channel 1150 // also pass in status 1151 channel = l2cap_get_le_channel_for_address_and_addr_type(address, addr_type); 1152 if (!channel) break; 1153 l2cap_handle_le_connection_complete(channel, packet[3], little_endian_read_16(packet, 4)); 1154 break; 1155 default: 1156 break; 1157 } 1158 break; 1159 #endif 1160 1161 case GAP_EVENT_SECURITY_LEVEL: 1162 handle = little_endian_read_16(packet, 2); 1163 log_info("l2cap - security level update"); 1164 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1165 while (btstack_linked_list_iterator_has_next(&it)){ 1166 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1167 if (channel->con_handle != handle) continue; 1168 1169 log_info("l2cap - state %u", channel->state); 1170 1171 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1172 gap_security_level_t required_level = channel->required_security_level; 1173 1174 switch (channel->state){ 1175 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1176 if (actual_level >= required_level){ 1177 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1178 l2cap_emit_connection_request(channel); 1179 } else { 1180 channel->reason = 0x0003; // security block 1181 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1182 } 1183 break; 1184 1185 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1186 if (actual_level >= required_level){ 1187 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1188 } else { 1189 // disconnnect, authentication not good enough 1190 hci_disconnect_security_block(handle); 1191 } 1192 break; 1193 1194 default: 1195 break; 1196 } 1197 } 1198 break; 1199 1200 default: 1201 break; 1202 } 1203 1204 l2cap_run(); 1205 } 1206 1207 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1208 channel->remote_sig_id = identifier; 1209 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1210 l2cap_run(); 1211 } 1212 1213 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 1214 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1215 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1216 signaling_responses[signaling_responses_pending].handle = handle; 1217 signaling_responses[signaling_responses_pending].code = code; 1218 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1219 signaling_responses[signaling_responses_pending].data = data; 1220 signaling_responses_pending++; 1221 l2cap_run(); 1222 } 1223 } 1224 1225 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1226 1227 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1228 l2cap_service_t *service = l2cap_get_service(psm); 1229 if (!service) { 1230 // 0x0002 PSM not supported 1231 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 1232 return; 1233 } 1234 1235 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1236 if (!hci_connection) { 1237 // 1238 log_error("no hci_connection for handle %u", handle); 1239 return; 1240 } 1241 1242 // alloc structure 1243 // log_info("l2cap_handle_connection_request register channel"); 1244 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 1245 psm, service->mtu, service->required_security_level); 1246 if (!channel){ 1247 // 0x0004 No resources available 1248 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 1249 return; 1250 } 1251 1252 channel->con_handle = handle; 1253 channel->remote_cid = source_cid; 1254 channel->remote_sig_id = sig_id; 1255 1256 // limit local mtu to max acl packet length - l2cap header 1257 if (channel->local_mtu > l2cap_max_mtu()) { 1258 channel->local_mtu = l2cap_max_mtu(); 1259 } 1260 1261 // set initial state 1262 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1263 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 1264 1265 // add to connections list 1266 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1267 1268 // assert security requirements 1269 gap_request_security_level(handle, channel->required_security_level); 1270 } 1271 1272 void l2cap_accept_connection(uint16_t local_cid){ 1273 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1274 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1275 if (!channel) { 1276 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1277 return; 1278 } 1279 1280 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1281 1282 // process 1283 l2cap_run(); 1284 } 1285 1286 void l2cap_decline_connection(uint16_t local_cid){ 1287 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 1288 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1289 if (!channel) { 1290 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1291 return; 1292 } 1293 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1294 channel->reason = 0x04; // no resources available 1295 l2cap_run(); 1296 } 1297 1298 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1299 1300 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1301 1302 uint16_t flags = little_endian_read_16(command, 6); 1303 if (flags & 1) { 1304 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1305 } 1306 1307 // accept the other's configuration options 1308 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1309 uint16_t pos = 8; 1310 while (pos < end_pos){ 1311 uint8_t option_hint = command[pos] >> 7; 1312 uint8_t option_type = command[pos] & 0x7f; 1313 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1314 pos++; 1315 uint8_t length = command[pos++]; 1316 // MTU { type(8): 1, len(8):2, MTU(16) } 1317 if (option_type == 1 && length == 2){ 1318 channel->remote_mtu = little_endian_read_16(command, pos); 1319 // log_info("l2cap cid 0x%02x, remote mtu %u", channel->local_cid, channel->remote_mtu); 1320 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1321 } 1322 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1323 if (option_type == 2 && length == 2){ 1324 channel->flush_timeout = little_endian_read_16(command, pos); 1325 } 1326 // check for unknown options 1327 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1328 log_info("l2cap cid %u, unknown options", channel->local_cid); 1329 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1330 } 1331 pos += length; 1332 } 1333 } 1334 1335 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1336 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1337 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1338 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1339 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 1340 if (channel->state == L2CAP_STATE_OPEN) return 0; 1341 return 1; 1342 } 1343 1344 1345 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1346 1347 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1348 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1349 uint16_t result = 0; 1350 1351 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1352 1353 // handle DISCONNECT REQUESTS seperately 1354 if (code == DISCONNECTION_REQUEST){ 1355 switch (channel->state){ 1356 case L2CAP_STATE_CONFIG: 1357 case L2CAP_STATE_OPEN: 1358 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1359 case L2CAP_STATE_WAIT_DISCONNECT: 1360 l2cap_handle_disconnect_request(channel, identifier); 1361 break; 1362 1363 default: 1364 // ignore in other states 1365 break; 1366 } 1367 return; 1368 } 1369 1370 // @STATEMACHINE(l2cap) 1371 switch (channel->state) { 1372 1373 case L2CAP_STATE_WAIT_CONNECT_RSP: 1374 switch (code){ 1375 case CONNECTION_RESPONSE: 1376 l2cap_stop_rtx(channel); 1377 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1378 switch (result) { 1379 case 0: 1380 // successful connection 1381 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1382 channel->state = L2CAP_STATE_CONFIG; 1383 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1384 break; 1385 case 1: 1386 // connection pending. get some coffee, but start the ERTX 1387 l2cap_start_ertx(channel); 1388 break; 1389 default: 1390 // channel closed 1391 channel->state = L2CAP_STATE_CLOSED; 1392 // map l2cap connection response result to BTstack status enumeration 1393 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1394 1395 // drop link key if security block 1396 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1397 gap_drop_link_key_for_bd_addr(channel->address); 1398 } 1399 1400 // discard channel 1401 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1402 btstack_memory_l2cap_channel_free(channel); 1403 break; 1404 } 1405 break; 1406 1407 default: 1408 //@TODO: implement other signaling packets 1409 break; 1410 } 1411 break; 1412 1413 case L2CAP_STATE_CONFIG: 1414 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1415 switch (code) { 1416 case CONFIGURE_REQUEST: 1417 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1418 l2cap_signaling_handle_configure_request(channel, command); 1419 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1420 // only done if continuation not set 1421 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1422 } 1423 break; 1424 case CONFIGURE_RESPONSE: 1425 l2cap_stop_rtx(channel); 1426 switch (result){ 1427 case 0: // success 1428 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1429 break; 1430 case 4: // pending 1431 l2cap_start_ertx(channel); 1432 break; 1433 default: 1434 // retry on negative result 1435 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1436 break; 1437 } 1438 break; 1439 default: 1440 break; 1441 } 1442 if (l2cap_channel_ready_for_open(channel)){ 1443 // for open: 1444 channel->state = L2CAP_STATE_OPEN; 1445 l2cap_emit_channel_opened(channel, 0); 1446 } 1447 break; 1448 1449 case L2CAP_STATE_WAIT_DISCONNECT: 1450 switch (code) { 1451 case DISCONNECTION_RESPONSE: 1452 l2cap_finialize_channel_close(channel); 1453 break; 1454 default: 1455 //@TODO: implement other signaling packets 1456 break; 1457 } 1458 break; 1459 1460 case L2CAP_STATE_CLOSED: 1461 // @TODO handle incoming requests 1462 break; 1463 1464 case L2CAP_STATE_OPEN: 1465 //@TODO: implement other signaling packets, e.g. re-configure 1466 break; 1467 default: 1468 break; 1469 } 1470 // log_info("new state %u", channel->state); 1471 } 1472 1473 1474 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1475 1476 // get code, signalind identifier and command len 1477 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1478 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1479 1480 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1481 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1482 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1483 return; 1484 } 1485 1486 // general commands without an assigned channel 1487 switch(code) { 1488 1489 case CONNECTION_REQUEST: { 1490 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1491 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1492 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1493 return; 1494 } 1495 1496 case ECHO_REQUEST: 1497 l2cap_register_signaling_response(handle, code, sig_id, 0); 1498 return; 1499 1500 case INFORMATION_REQUEST: { 1501 uint16_t infoType = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1502 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1503 return; 1504 } 1505 1506 default: 1507 break; 1508 } 1509 1510 1511 // Get potential destination CID 1512 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1513 1514 // Find channel for this sig_id and connection handle 1515 btstack_linked_list_iterator_t it; 1516 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1517 while (btstack_linked_list_iterator_has_next(&it)){ 1518 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1519 if (channel->con_handle != handle) continue; 1520 if (code & 1) { 1521 // match odd commands (responses) by previous signaling identifier 1522 if (channel->local_sig_id == sig_id) { 1523 l2cap_signaling_handler_channel(channel, command); 1524 break; 1525 } 1526 } else { 1527 // match even commands (requests) by local channel id 1528 if (channel->local_cid == dest_cid) { 1529 l2cap_signaling_handler_channel(channel, command); 1530 break; 1531 } 1532 } 1533 } 1534 } 1535 1536 #ifdef ENABLE_BLE 1537 // @returns valid 1538 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 1539 hci_connection_t * connection; 1540 uint16_t result; 1541 uint8_t event[10]; 1542 uint16_t le_psm; 1543 uint16_t local_cid; 1544 l2cap_service_t * service; 1545 l2cap_channel_t * channel; 1546 btstack_linked_list_iterator_t it; 1547 1548 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1549 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 1550 1551 switch (code){ 1552 1553 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 1554 result = little_endian_read_16(command, 4); 1555 l2cap_emit_connection_parameter_update_response(handle, result); 1556 break; 1557 1558 case CONNECTION_PARAMETER_UPDATE_REQUEST: 1559 connection = hci_connection_for_handle(handle); 1560 if (connection){ 1561 if (connection->role != HCI_ROLE_MASTER){ 1562 // reject command without notifying upper layer when not in master role 1563 return 0; 1564 } 1565 int update_parameter = 1; 1566 le_connection_parameter_range_t existing_range; 1567 gap_get_connection_parameter_range(&existing_range); 1568 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 1569 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 1570 uint16_t le_conn_latency = little_endian_read_16(command,12); 1571 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 1572 1573 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 1574 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 1575 1576 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 1577 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 1578 1579 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 1580 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 1581 1582 if (update_parameter){ 1583 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 1584 connection->le_conn_interval_min = le_conn_interval_min; 1585 connection->le_conn_interval_max = le_conn_interval_max; 1586 connection->le_conn_latency = le_conn_latency; 1587 connection->le_supervision_timeout = le_supervision_timeout; 1588 } else { 1589 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 1590 } 1591 connection->le_con_param_update_identifier = sig_id; 1592 } 1593 1594 if (!l2cap_event_packet_handler) break; 1595 1596 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 1597 event[1] = 8; 1598 memcpy(&event[2], &command[4], 8); 1599 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1600 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1601 break; 1602 1603 case LE_CREDIT_BASED_CONNECTION_REQUEST: 1604 1605 // get hci connection, bail if not found (must not happen) 1606 connection = hci_connection_for_handle(handle); 1607 if (!connection) return 0; 1608 1609 // check if service registered 1610 le_psm = little_endian_read_16(command, 4); 1611 service = l2cap_le_get_service(le_psm); 1612 1613 if (service){ 1614 1615 uint16_t source_cid = little_endian_read_16(command, 6); 1616 if (source_cid < 0x40){ 1617 // 0x0009 Connection refused - Invalid Source CID 1618 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0009); 1619 return 1; 1620 } 1621 1622 // go through list of channels for this ACL connection and check if we get a match 1623 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1624 while (btstack_linked_list_iterator_has_next(&it)){ 1625 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1626 if (a_channel->con_handle != handle) continue; 1627 if (a_channel->remote_cid != source_cid) continue; 1628 // 0x000a Connection refused - Source CID already allocated 1629 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x000a); 1630 return 1; 1631 } 1632 1633 // TODO: deal with authentication requirements, errors 0x005 - 000x8 1634 1635 // allocate channel 1636 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 1637 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 1638 if (!channel){ 1639 // 0x0004 Connection refused – no resources available 1640 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0004); 1641 return 1; 1642 } 1643 1644 channel->con_handle = handle; 1645 channel->remote_cid = source_cid; 1646 channel->remote_sig_id = sig_id; 1647 channel->remote_mtu = little_endian_read_16(command, 8); 1648 channel->remote_mps = little_endian_read_16(command, 10); 1649 channel->credits_outgoing = little_endian_read_16(command, 12); 1650 1651 // set initial state 1652 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1653 1654 // add to connections list 1655 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1656 1657 // post connection request event 1658 l2cap_emit_connection_request(channel); 1659 1660 } else { 1661 // Connection refused – LE_PSM not supported 1662 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0002); 1663 } 1664 break; 1665 1666 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 1667 // Find channel for this sig_id and connection handle 1668 channel = NULL; 1669 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1670 while (btstack_linked_list_iterator_has_next(&it)){ 1671 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1672 if (a_channel->con_handle != handle) continue; 1673 if (a_channel->local_sig_id != sig_id) continue; 1674 channel = a_channel; 1675 break; 1676 } 1677 // TODO: send error 1678 if (!channel) break; 1679 1680 // cid + 0 1681 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 1682 if (result){ 1683 channel->state = L2CAP_STATE_CLOSED; 1684 // map l2cap connection response result to BTstack status enumeration 1685 l2cap_emit_channel_opened(channel, result); 1686 1687 // discard channel 1688 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1689 btstack_memory_l2cap_channel_free(channel); 1690 break; 1691 } 1692 1693 // success 1694 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1695 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1696 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 1697 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 1698 channel->state = L2CAP_STATE_OPEN; 1699 l2cap_emit_channel_opened(channel, result); 1700 break; 1701 1702 case DISCONNECTION_REQUEST: 1703 // find channel 1704 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1705 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1706 if (!channel) break; 1707 channel->remote_sig_id = sig_id; 1708 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1709 break; 1710 1711 default: 1712 // command unknown -> reject command 1713 return 0; 1714 } 1715 return 1; 1716 } 1717 #endif 1718 1719 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 1720 1721 // Get Channel ID 1722 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1723 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1724 1725 switch (channel_id) { 1726 1727 case L2CAP_CID_SIGNALING: { 1728 uint16_t command_offset = 8; 1729 while (command_offset < size) { 1730 // handle signaling commands 1731 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1732 1733 // increment command_offset 1734 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1735 } 1736 break; 1737 } 1738 1739 #ifdef ENABLE_BLE 1740 case L2CAP_CID_SIGNALING_LE: { 1741 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1742 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 1743 if (!valid){ 1744 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1745 } 1746 break; 1747 } 1748 #endif 1749 1750 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1751 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 1752 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1753 } 1754 break; 1755 1756 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1757 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 1758 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1759 } 1760 break; 1761 1762 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 1763 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 1764 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1765 } 1766 break; 1767 1768 default: { 1769 // Find channel for this channel_id and connection handle 1770 l2cap_channel_t * l2cap_channel; 1771 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 1772 if (l2cap_channel) { 1773 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1774 } 1775 #ifdef ENABLE_BLE 1776 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 1777 if (l2cap_channel) { 1778 // first fragment 1779 uint16_t pos = 0; 1780 if (!l2cap_channel->receive_sdu_len){ 1781 l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 1782 l2cap_channel->receive_sdu_pos = 0; 1783 pos += 2; 1784 size -= 2; 1785 } 1786 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); 1787 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 1788 // done? 1789 log_debug("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 1790 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 1791 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 1792 l2cap_channel->receive_sdu_len = 0; 1793 } 1794 } 1795 #endif 1796 break; 1797 } 1798 } 1799 1800 l2cap_run(); 1801 } 1802 1803 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1804 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 1805 channel->state = L2CAP_STATE_CLOSED; 1806 l2cap_emit_channel_closed(channel); 1807 // discard channel 1808 l2cap_stop_rtx(channel); 1809 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1810 btstack_memory_l2cap_channel_free(channel); 1811 } 1812 1813 #ifdef ENABLE_BLE 1814 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1815 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 1816 channel->state = L2CAP_STATE_CLOSED; 1817 l2cap_emit_channel_closed(channel); 1818 // discard channel 1819 l2cap_stop_rtx(channel); 1820 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1821 btstack_memory_l2cap_channel_free(channel); 1822 } 1823 #endif 1824 1825 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 1826 btstack_linked_list_iterator_t it; 1827 btstack_linked_list_iterator_init(&it, services); 1828 while (btstack_linked_list_iterator_has_next(&it)){ 1829 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 1830 if ( service->psm == psm){ 1831 return service; 1832 }; 1833 } 1834 return NULL; 1835 } 1836 1837 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 1838 return l2cap_get_service_internal(&l2cap_services, psm); 1839 } 1840 1841 1842 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 1843 1844 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1845 1846 // check for alread registered psm 1847 l2cap_service_t *service = l2cap_get_service(psm); 1848 if (service) { 1849 log_error("l2cap_register_service: PSM %u already registered", psm); 1850 return L2CAP_SERVICE_ALREADY_REGISTERED; 1851 } 1852 1853 // alloc structure 1854 service = btstack_memory_l2cap_service_get(); 1855 if (!service) { 1856 log_error("l2cap_register_service: no memory for l2cap_service_t"); 1857 return BTSTACK_MEMORY_ALLOC_FAILED; 1858 } 1859 1860 // fill in 1861 service->psm = psm; 1862 service->mtu = mtu; 1863 service->packet_handler = service_packet_handler; 1864 service->required_security_level = security_level; 1865 1866 // add to services list 1867 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 1868 1869 // enable page scan 1870 gap_connectable_control(1); 1871 1872 return 0; 1873 } 1874 1875 uint8_t l2cap_unregister_service(uint16_t psm){ 1876 1877 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1878 1879 l2cap_service_t *service = l2cap_get_service(psm); 1880 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 1881 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 1882 btstack_memory_l2cap_service_free(service); 1883 1884 // disable page scan when no services registered 1885 if (btstack_linked_list_empty(&l2cap_services)) { 1886 gap_connectable_control(0); 1887 } 1888 return 0; 1889 } 1890 1891 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1892 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 1893 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 1894 if (index < 0) return; 1895 fixed_channels[index].callback = the_packet_handler; 1896 } 1897 1898 #ifdef ENABLE_BLE 1899 1900 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 1901 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 1902 } 1903 1904 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 1905 1906 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 1907 1908 // check for alread registered psm 1909 l2cap_service_t *service = l2cap_le_get_service(psm); 1910 if (service) { 1911 return L2CAP_SERVICE_ALREADY_REGISTERED; 1912 } 1913 1914 // alloc structure 1915 service = btstack_memory_l2cap_service_get(); 1916 if (!service) { 1917 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 1918 return BTSTACK_MEMORY_ALLOC_FAILED; 1919 } 1920 1921 // fill in 1922 service->psm = psm; 1923 service->mtu = 0; 1924 service->packet_handler = packet_handler; 1925 service->required_security_level = security_level; 1926 1927 // add to services list 1928 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 1929 1930 // done 1931 return 0; 1932 } 1933 1934 uint8_t l2cap_le_unregister_service(uint16_t psm) { 1935 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 1936 l2cap_service_t *service = l2cap_le_get_service(psm); 1937 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 1938 1939 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 1940 btstack_memory_l2cap_service_free(service); 1941 return 0; 1942 } 1943 1944 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 1945 // get channel 1946 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 1947 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 1948 1949 // validate state 1950 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 1951 return ERROR_CODE_COMMAND_DISALLOWED; 1952 } 1953 1954 // set state accept connection 1955 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 1956 channel->receive_sdu_buffer = receive_sdu_buffer; 1957 channel->local_mtu = mtu; 1958 channel->credits_incoming = initial_credits; 1959 1960 // go 1961 l2cap_run(); 1962 return 0; 1963 } 1964 1965 /** 1966 * @brief Deny incoming LE Data Channel connection due to resource constraints 1967 * @param local_cid L2CAP LE Data Channel Identifier 1968 */ 1969 1970 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 1971 // get channel 1972 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 1973 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 1974 1975 // validate state 1976 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 1977 return ERROR_CODE_COMMAND_DISALLOWED; 1978 } 1979 1980 // set state decline connection 1981 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 1982 channel->reason = 0x04; // no resources available 1983 l2cap_run(); 1984 return 0; 1985 } 1986 1987 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 1988 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 1989 uint16_t * out_local_cid) { 1990 1991 log_info("L2CAP_LE_CREATE_CHANNEL addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 1992 1993 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, address, address_type, psm, mtu, security_level); 1994 if (!channel) { 1995 return BTSTACK_MEMORY_ALLOC_FAILED; 1996 } 1997 log_info("l2cap_le_create_channel %p", channel); 1998 1999 // store local_cid 2000 if (out_local_cid){ 2001 *out_local_cid = channel->local_cid; 2002 } 2003 2004 // provdide buffer 2005 channel->receive_sdu_buffer = receive_sdu_buffer; 2006 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 2007 2008 // add to connections list 2009 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2010 2011 // check if hci connection is already usable 2012 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, address_type); 2013 2014 if (conn){ 2015 log_info("l2cap_le_create_channel, hci connection already exists"); 2016 l2cap_handle_le_connection_complete(channel, 0, conn->con_handle); 2017 } else { 2018 2019 // 2020 // TODO: start timer 2021 // .. 2022 2023 // start connection 2024 uint8_t res = gap_auto_connection_start(address_type, address); 2025 if (res){ 2026 // discard channel object 2027 log_info("gap_auto_connection_start failed! 0x%02x", res); 2028 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2029 btstack_memory_l2cap_channel_free(channel); 2030 return res; 2031 } 2032 } 2033 return 0; 2034 } 2035 2036 /** 2037 * @brief Provide credtis for LE Data Channel 2038 * @param local_cid L2CAP LE Data Channel Identifier 2039 * @param credits Number additional credits for peer 2040 */ 2041 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 2042 // get channel 2043 // bail if missing 2044 // check state 2045 // check incoming credits + credits <= 0xffff 2046 // set credits_granted 2047 // l2cap_le_run() 2048 return 0; 2049 } 2050 2051 /** 2052 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 2053 * @param local_cid L2CAP LE Data Channel Identifier 2054 */ 2055 int l2cap_le_can_send_now(uint16_t local_cid){ 2056 // check if data can be sent via le at all 2057 return 0; 2058 } 2059 2060 /** 2061 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 2062 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 2063 * so packet handler should be ready to handle it 2064 * @param local_cid L2CAP LE Data Channel Identifier 2065 */ 2066 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 2067 // same as for non-le 2068 return 0; 2069 } 2070 2071 /** 2072 * @brief Send data via LE Data Channel 2073 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 2074 * @param local_cid L2CAP LE Data Channel Identifier 2075 * @param data data to send 2076 * @param size data size 2077 */ 2078 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 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 if (len > channel->remote_mtu){ 2087 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 2088 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 2089 } 2090 2091 if (channel->send_sdu_buffer){ 2092 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 2093 return BTSTACK_ACL_BUFFERS_FULL; 2094 } 2095 2096 channel->send_sdu_buffer = data; 2097 channel->send_sdu_len = len; 2098 channel->send_sdu_pos = 0; 2099 2100 l2cap_run(); 2101 return 0; 2102 } 2103 2104 /** 2105 * @brief Disconnect from LE Data Channel 2106 * @param local_cid L2CAP LE Data Channel Identifier 2107 */ 2108 uint8_t l2cap_le_disconnect(uint16_t local_cid) 2109 { 2110 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2111 if (!channel) { 2112 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2113 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2114 } 2115 2116 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2117 l2cap_run(); 2118 return 0; 2119 } 2120 2121 #endif 2122