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 // nr of credits provided to remote if credits fall below watermark 65 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK 5 66 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT 5 67 68 // offsets for L2CAP SIGNALING COMMANDS 69 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 70 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 71 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 72 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 73 74 // internal table 75 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL 0 76 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL 1 77 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL 2 78 #define L2CAP_FIXED_CHANNEL_TABLE_SIZE (L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL+1) 79 80 // prototypes 81 static void l2cap_finialize_channel_close(l2cap_channel_t *channel); 82 static inline l2cap_service_t * l2cap_get_service(uint16_t psm); 83 static void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status); 84 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel); 85 static void l2cap_emit_channel_closed(l2cap_channel_t *channel); 86 static void l2cap_emit_connection_request(l2cap_channel_t *channel); 87 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); 88 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); 89 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ); 90 static void l2cap_notify_channel_can_send(void); 91 #ifdef ENABLE_BLE 92 static void l2cap_le_finialize_channel_close(l2cap_channel_t *channel); 93 static inline l2cap_service_t * l2cap_le_get_service(uint16_t psm); 94 #endif 95 96 typedef struct l2cap_fixed_channel { 97 btstack_packet_handler_t callback; 98 uint8_t waiting_for_can_send_now; 99 } l2cap_fixed_channel_t; 100 101 static btstack_linked_list_t l2cap_channels; 102 static btstack_linked_list_t l2cap_services; 103 static btstack_linked_list_t l2cap_le_channels; 104 static btstack_linked_list_t l2cap_le_services; 105 106 // used to cache l2cap rejects, echo, and informational requests 107 static l2cap_signaling_response_t signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; 108 static int signaling_responses_pending; 109 110 static uint8_t require_security_level2_for_outgoing_sdp; 111 112 static btstack_packet_callback_registration_t hci_event_callback_registration; 113 114 static btstack_packet_handler_t l2cap_event_packet_handler; 115 static l2cap_fixed_channel_t fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_SIZE]; 116 117 static uint16_t l2cap_fixed_channel_table_channel_id_for_index(int index){ 118 switch (index){ 119 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL: 120 return L2CAP_CID_ATTRIBUTE_PROTOCOL; 121 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL: 122 return L2CAP_CID_SECURITY_MANAGER_PROTOCOL; 123 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL: 124 return L2CAP_CID_CONNECTIONLESS_CHANNEL; 125 default: 126 return 0; 127 } 128 } 129 static int l2cap_fixed_channel_table_index_for_channel_id(uint16_t channel_id){ 130 switch (channel_id){ 131 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 132 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL; 133 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 134 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL; 135 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 136 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL; 137 default: 138 return -1; 139 } 140 } 141 142 static int l2cap_fixed_channel_table_index_is_le(int index){ 143 if (index == L2CAP_CID_CONNECTIONLESS_CHANNEL) return 0; 144 return 1; 145 } 146 147 void l2cap_init(void){ 148 signaling_responses_pending = 0; 149 150 l2cap_channels = NULL; 151 l2cap_services = NULL; 152 l2cap_le_services = NULL; 153 l2cap_le_channels = NULL; 154 155 l2cap_event_packet_handler = NULL; 156 memset(fixed_channels, 0, sizeof(fixed_channels)); 157 158 require_security_level2_for_outgoing_sdp = 0; 159 160 // 161 // register callback with HCI 162 // 163 hci_event_callback_registration.callback = &l2cap_hci_event_handler; 164 hci_add_event_handler(&hci_event_callback_registration); 165 166 hci_register_acl_packet_handler(&l2cap_acl_handler); 167 168 gap_connectable_control(0); // no services yet 169 } 170 171 void l2cap_register_packet_handler(void (*handler)(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 172 l2cap_event_packet_handler = handler; 173 } 174 175 static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 176 (* (channel->packet_handler))(type, channel->local_cid, data, size); 177 } 178 179 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 180 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", 181 status, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 182 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 183 uint8_t event[23]; 184 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 185 event[1] = sizeof(event) - 2; 186 event[2] = status; 187 reverse_bd_addr(channel->address, &event[3]); 188 little_endian_store_16(event, 9, channel->con_handle); 189 little_endian_store_16(event, 11, channel->psm); 190 little_endian_store_16(event, 13, channel->local_cid); 191 little_endian_store_16(event, 15, channel->remote_cid); 192 little_endian_store_16(event, 17, channel->local_mtu); 193 little_endian_store_16(event, 19, channel->remote_mtu); 194 little_endian_store_16(event, 21, channel->flush_timeout); 195 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 196 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 197 } 198 199 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 200 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 201 uint8_t event[4]; 202 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 203 event[1] = sizeof(event) - 2; 204 little_endian_store_16(event, 2, channel->local_cid); 205 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 206 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 207 } 208 209 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 210 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 211 bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid); 212 uint8_t event[16]; 213 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 214 event[1] = sizeof(event) - 2; 215 reverse_bd_addr(channel->address, &event[2]); 216 little_endian_store_16(event, 8, channel->con_handle); 217 little_endian_store_16(event, 10, channel->psm); 218 little_endian_store_16(event, 12, channel->local_cid); 219 little_endian_store_16(event, 14, channel->remote_cid); 220 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 221 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 222 } 223 224 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel) { 225 log_info("L2CAP_EVENT_CHANNEL_CAN_SEND_NOW local_cid 0x%x", channel); 226 uint8_t event[4]; 227 event[0] = L2CAP_EVENT_CAN_SEND_NOW; 228 event[1] = sizeof(event) - 2; 229 little_endian_store_16(event, 2, channel); 230 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 231 packet_handler(HCI_EVENT_PACKET, channel, event, sizeof(event)); 232 } 233 234 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 235 uint8_t event[6]; 236 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 237 event[1] = 4; 238 little_endian_store_16(event, 2, con_handle); 239 little_endian_store_16(event, 4, result); 240 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 241 if (!l2cap_event_packet_handler) return; 242 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 243 } 244 245 static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 246 btstack_linked_list_iterator_t it; 247 btstack_linked_list_iterator_init(&it, &l2cap_channels); 248 while (btstack_linked_list_iterator_has_next(&it)){ 249 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 250 if ( channel->local_cid == local_cid) { 251 return channel; 252 } 253 } 254 return NULL; 255 } 256 257 #ifdef ENABLE_BLE 258 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 259 btstack_linked_list_iterator_t it; 260 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 261 while (btstack_linked_list_iterator_has_next(&it)){ 262 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 263 if ( channel->local_cid == local_cid) { 264 return channel; 265 } 266 } 267 return NULL; 268 } 269 #endif 270 271 static l2cap_channel_t * l2cap_get_le_channel_for_address_and_addr_type(bd_addr_t address, bd_addr_type_t address_type){ 272 btstack_linked_list_iterator_t it; 273 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 274 while (btstack_linked_list_iterator_has_next(&it)){ 275 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 276 if (channel->address_type != address_type) continue; 277 if (bd_addr_cmp(channel->address, address)) continue; 278 return channel; 279 } 280 return NULL; 281 } 282 283 /// 284 285 void l2cap_request_can_send_now_event(uint16_t local_cid){ 286 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 287 if (!channel) return; 288 channel->waiting_for_can_send_now = 1; 289 l2cap_notify_channel_can_send(); 290 } 291 292 void l2cap_request_can_send_fix_channel_now_event(hci_con_handle_t con_handle, uint16_t channel_id){ 293 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 294 if (index < 0) return; 295 fixed_channels[index].waiting_for_can_send_now = 1; 296 l2cap_notify_channel_can_send(); 297 } 298 299 /// 300 301 int l2cap_can_send_packet_now(uint16_t local_cid){ 302 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 303 if (!channel) return 0; 304 return hci_can_send_acl_packet_now(channel->con_handle); 305 } 306 307 int l2cap_can_send_prepared_packet_now(uint16_t local_cid){ 308 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 309 if (!channel) return 0; 310 return hci_can_send_prepared_acl_packet_now(channel->con_handle); 311 } 312 313 int l2cap_can_send_fixed_channel_packet_now(hci_con_handle_t con_handle, uint16_t channel_id){ 314 return hci_can_send_acl_packet_now(con_handle); 315 } 316 317 /// 318 319 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 320 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 321 if (channel) { 322 return channel->remote_mtu; 323 } 324 return 0; 325 } 326 327 static l2cap_channel_t * l2cap_channel_for_rtx_timer(btstack_timer_source_t * ts){ 328 btstack_linked_list_iterator_t it; 329 btstack_linked_list_iterator_init(&it, &l2cap_channels); 330 while (btstack_linked_list_iterator_has_next(&it)){ 331 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 332 if ( &channel->rtx == ts) { 333 return channel; 334 } 335 } 336 return NULL; 337 } 338 339 static void l2cap_rtx_timeout(btstack_timer_source_t * ts){ 340 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 341 if (!channel) return; 342 343 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 344 345 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 346 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 347 // notify client 348 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 349 350 // discard channel 351 // no need to stop timer here, it is removed from list during timer callback 352 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 353 btstack_memory_l2cap_channel_free(channel); 354 } 355 356 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 357 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 358 btstack_run_loop_remove_timer(&channel->rtx); 359 } 360 361 static void l2cap_start_rtx(l2cap_channel_t * channel){ 362 l2cap_stop_rtx(channel); 363 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 364 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 365 btstack_run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 366 btstack_run_loop_add_timer(&channel->rtx); 367 } 368 369 static void l2cap_start_ertx(l2cap_channel_t * channel){ 370 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 371 l2cap_stop_rtx(channel); 372 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 373 btstack_run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 374 btstack_run_loop_add_timer(&channel->rtx); 375 } 376 377 void l2cap_require_security_level_2_for_outgoing_sdp(void){ 378 require_security_level2_for_outgoing_sdp = 1; 379 } 380 381 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 382 return (psm == PSM_SDP) && (!require_security_level2_for_outgoing_sdp); 383 } 384 385 static int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 386 387 if (!hci_can_send_acl_packet_now(handle)){ 388 log_info("l2cap_send_signaling_packet, cannot send"); 389 return BTSTACK_ACL_BUFFERS_FULL; 390 } 391 392 // log_info("l2cap_send_signaling_packet type %u", cmd); 393 hci_reserve_packet_buffer(); 394 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 395 va_list argptr; 396 va_start(argptr, identifier); 397 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 398 va_end(argptr); 399 // log_info("l2cap_send_signaling_packet con %u!", handle); 400 return hci_send_acl_packet_buffer(len); 401 } 402 403 #ifdef ENABLE_BLE 404 static int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 405 406 if (!hci_can_send_acl_packet_now(handle)){ 407 log_info("l2cap_send_signaling_packet, cannot send"); 408 return BTSTACK_ACL_BUFFERS_FULL; 409 } 410 411 // log_info("l2cap_send_signaling_packet type %u", cmd); 412 hci_reserve_packet_buffer(); 413 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 414 va_list argptr; 415 va_start(argptr, identifier); 416 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 417 va_end(argptr); 418 // log_info("l2cap_send_signaling_packet con %u!", handle); 419 return hci_send_acl_packet_buffer(len); 420 } 421 #endif 422 423 uint8_t *l2cap_get_outgoing_buffer(void){ 424 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 425 } 426 427 int l2cap_reserve_packet_buffer(void){ 428 return hci_reserve_packet_buffer(); 429 } 430 431 void l2cap_release_packet_buffer(void){ 432 hci_release_packet_buffer(); 433 } 434 435 static void l2cap_setup_header(uint8_t * acl_buffer, hci_con_handle_t con_handle, uint16_t remote_cid, uint16_t len){ 436 437 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 438 439 // 0 - Connection handle : PB=pb : BC=00 440 little_endian_store_16(acl_buffer, 0, con_handle | (pb << 12) | (0 << 14)); 441 // 2 - ACL length 442 little_endian_store_16(acl_buffer, 2, len + 4); 443 // 4 - L2CAP packet length 444 little_endian_store_16(acl_buffer, 4, len + 0); 445 // 6 - L2CAP channel DEST 446 little_endian_store_16(acl_buffer, 6, remote_cid); 447 } 448 449 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 450 451 if (!hci_is_packet_buffer_reserved()){ 452 log_error("l2cap_send_prepared called without reserving packet first"); 453 return BTSTACK_ACL_BUFFERS_FULL; 454 } 455 456 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 457 if (!channel) { 458 log_error("l2cap_send_prepared no channel for cid 0x%02x", local_cid); 459 return -1; // TODO: define error 460 } 461 462 if (!hci_can_send_prepared_acl_packet_now(channel->con_handle)){ 463 log_info("l2cap_send_prepared cid 0x%02x, cannot send", local_cid); 464 return BTSTACK_ACL_BUFFERS_FULL; 465 } 466 467 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used", local_cid, channel->con_handle); 468 469 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 470 l2cap_setup_header(acl_buffer, channel->con_handle, channel->remote_cid, len); 471 // send 472 return hci_send_acl_packet_buffer(len+8); 473 } 474 475 int l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len){ 476 477 if (!hci_is_packet_buffer_reserved()){ 478 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 479 return BTSTACK_ACL_BUFFERS_FULL; 480 } 481 482 if (!hci_can_send_prepared_acl_packet_now(con_handle)){ 483 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send", con_handle, cid); 484 return BTSTACK_ACL_BUFFERS_FULL; 485 } 486 487 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x", con_handle, cid); 488 489 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 490 l2cap_setup_header(acl_buffer, con_handle, cid, len); 491 // send 492 return hci_send_acl_packet_buffer(len+8); 493 } 494 495 int l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len){ 496 497 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 498 if (!channel) { 499 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 500 return -1; // TODO: define error 501 } 502 503 if (len > channel->remote_mtu){ 504 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 505 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 506 } 507 508 if (!hci_can_send_acl_packet_now(channel->con_handle)){ 509 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 510 return BTSTACK_ACL_BUFFERS_FULL; 511 } 512 513 hci_reserve_packet_buffer(); 514 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 515 516 memcpy(&acl_buffer[8], data, len); 517 518 return l2cap_send_prepared(local_cid, len); 519 } 520 521 int l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len){ 522 523 if (!hci_can_send_acl_packet_now(con_handle)){ 524 log_info("l2cap_send cid 0x%02x, cannot send", cid); 525 return BTSTACK_ACL_BUFFERS_FULL; 526 } 527 528 hci_reserve_packet_buffer(); 529 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 530 531 memcpy(&acl_buffer[8], data, len); 532 533 return l2cap_send_prepared_connectionless(con_handle, cid, len); 534 } 535 536 int l2cap_send_echo_request(hci_con_handle_t con_handle, uint8_t *data, uint16_t len){ 537 return l2cap_send_signaling_packet(con_handle, ECHO_REQUEST, 0x77, len, data); 538 } 539 540 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 541 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 542 } 543 544 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 545 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 546 } 547 548 549 550 // MARK: L2CAP_RUN 551 // process outstanding signaling tasks 552 static void l2cap_run(void){ 553 554 // log_info("l2cap_run: entered"); 555 556 // check pending signaling responses 557 while (signaling_responses_pending){ 558 559 hci_con_handle_t handle = signaling_responses[0].handle; 560 561 if (!hci_can_send_acl_packet_now(handle)) break; 562 563 uint8_t sig_id = signaling_responses[0].sig_id; 564 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 565 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 566 uint8_t response_code = signaling_responses[0].code; 567 568 // remove first item before sending (to avoid sending response mutliple times) 569 signaling_responses_pending--; 570 int i; 571 for (i=0; i < signaling_responses_pending; i++){ 572 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 573 } 574 575 switch (response_code){ 576 case CONNECTION_REQUEST: 577 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 578 // also disconnect if result is 0x0003 - security blocked 579 if (result == 0x0003){ 580 hci_disconnect_security_block(handle); 581 } 582 break; 583 case ECHO_REQUEST: 584 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 585 break; 586 case INFORMATION_REQUEST: 587 switch (infoType){ 588 case 1: { // Connectionless MTU 589 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 590 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 591 break; 592 } 593 case 2: { // Extended Features Supported 594 // extended features request supported, features: fixed channels, unicast connectionless data reception 595 uint32_t features = 0x280; 596 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 597 break; 598 } 599 case 3: { // Fixed Channels Supported 600 uint8_t map[8]; 601 memset(map, 0, 8); 602 map[0] = 0x06; // L2CAP Signaling Channel (0x02) + Connectionless reception (0x04) 603 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 604 break; 605 } 606 default: 607 // all other types are not supported 608 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 609 break; 610 } 611 break; 612 case COMMAND_REJECT: 613 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 614 #ifdef ENABLE_BLE 615 case COMMAND_REJECT_LE: 616 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 617 break; 618 #endif 619 default: 620 // should not happen 621 break; 622 } 623 } 624 625 uint8_t config_options[4]; 626 btstack_linked_list_iterator_t it; 627 btstack_linked_list_iterator_init(&it, &l2cap_channels); 628 while (btstack_linked_list_iterator_has_next(&it)){ 629 630 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 631 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 632 switch (channel->state){ 633 634 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 635 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 636 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 637 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 638 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 639 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 640 } 641 break; 642 643 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 644 if (!hci_can_send_command_packet_now()) break; 645 // send connection request - set state first 646 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 647 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 648 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 649 break; 650 651 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 652 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 653 channel->state = L2CAP_STATE_INVALID; 654 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 655 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 656 l2cap_stop_rtx(channel); 657 btstack_linked_list_iterator_remove(&it); 658 btstack_memory_l2cap_channel_free(channel); 659 break; 660 661 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 662 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 663 channel->state = L2CAP_STATE_CONFIG; 664 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 665 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 666 break; 667 668 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 669 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 670 // success, start l2cap handshake 671 channel->local_sig_id = l2cap_next_sig_id(); 672 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 673 l2cap_send_signaling_packet( channel->con_handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 674 l2cap_start_rtx(channel); 675 break; 676 677 case L2CAP_STATE_CONFIG: 678 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 679 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 680 uint16_t flags = 0; 681 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 682 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 683 flags = 1; 684 } else { 685 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 686 } 687 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 688 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 689 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 690 config_options[0] = 1; // MTU 691 config_options[1] = 2; // len param 692 little_endian_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 693 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 694 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 695 } else { 696 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 697 } 698 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 699 } 700 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 701 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 702 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 703 channel->local_sig_id = l2cap_next_sig_id(); 704 config_options[0] = 1; // MTU 705 config_options[1] = 2; // len param 706 little_endian_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 707 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 708 l2cap_start_rtx(channel); 709 } 710 if (l2cap_channel_ready_for_open(channel)){ 711 channel->state = L2CAP_STATE_OPEN; 712 l2cap_emit_channel_opened(channel, 0); // success 713 } 714 break; 715 716 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 717 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 718 channel->state = L2CAP_STATE_INVALID; 719 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 720 // 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 :) 721 l2cap_finialize_channel_close(channel); // -- remove from list 722 break; 723 724 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 725 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 726 channel->local_sig_id = l2cap_next_sig_id(); 727 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 728 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 729 break; 730 default: 731 break; 732 } 733 } 734 735 #ifdef ENABLE_BLE 736 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 737 while (btstack_linked_list_iterator_has_next(&it)){ 738 uint8_t * acl_buffer; 739 uint8_t * l2cap_payload; 740 uint16_t pos; 741 uint16_t payload_size; 742 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 743 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 744 switch (channel->state){ 745 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 746 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 747 channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; 748 // le psm, source cid, mtu, mps, initial credits 749 channel->local_sig_id = l2cap_next_sig_id(); 750 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); 751 break; 752 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 753 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 754 // TODO: support larger MPS 755 channel->state = L2CAP_STATE_OPEN; 756 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); 757 // notify client 758 l2cap_emit_channel_opened(channel, 0); 759 break; 760 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 761 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 762 channel->state = L2CAP_STATE_INVALID; 763 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); 764 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 765 l2cap_stop_rtx(channel); 766 btstack_linked_list_iterator_remove(&it); 767 btstack_memory_l2cap_channel_free(channel); 768 break; 769 case L2CAP_STATE_OPEN: 770 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 771 772 // send credits 773 if (channel->new_credits_incoming){ 774 log_info("l2cap: sending %u credits", channel->new_credits_incoming); 775 channel->local_sig_id = l2cap_next_sig_id(); 776 uint16_t new_credits = channel->new_credits_incoming; 777 channel->new_credits_incoming = 0; 778 channel->credits_incoming += new_credits; 779 l2cap_send_le_signaling_packet(channel->con_handle, LE_FLOW_CONTROL_CREDIT, channel->local_sig_id, channel->remote_cid, new_credits); 780 break; 781 } 782 783 // send data 784 if (!channel->send_sdu_buffer) break; 785 if (!channel->credits_outgoing) break; 786 787 // send part of SDU 788 hci_reserve_packet_buffer(); 789 acl_buffer = hci_get_outgoing_packet_buffer(); 790 l2cap_payload = acl_buffer + 8; 791 pos = 0; 792 if (!channel->send_sdu_pos){ 793 // store SDU len 794 channel->send_sdu_pos += 2; 795 little_endian_store_16(l2cap_payload, pos, channel->send_sdu_len); 796 pos += 2; 797 } 798 payload_size = btstack_min(channel->send_sdu_len + 2 - channel->send_sdu_pos, channel->remote_mps - pos); 799 log_info("len %u, pos %u => payload %u, credits %u", channel->send_sdu_len, channel->send_sdu_pos, payload_size, channel->credits_outgoing); 800 memcpy(&l2cap_payload[pos], &channel->send_sdu_buffer[channel->send_sdu_pos-2], payload_size); // -2 for virtual SDU len 801 pos += payload_size; 802 channel->send_sdu_pos += payload_size; 803 l2cap_setup_header(acl_buffer, channel->con_handle, channel->remote_cid, payload_size); 804 // done 805 806 channel->credits_outgoing--; 807 808 if (channel->send_sdu_pos >= channel->send_sdu_len + 2){ 809 channel->send_sdu_buffer = NULL; 810 // TODO: send done event 811 } 812 hci_send_acl_packet_buffer(8 + pos); 813 break; 814 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 815 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 816 channel->local_sig_id = l2cap_next_sig_id(); 817 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 818 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 819 break; 820 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 821 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 822 channel->state = L2CAP_STATE_INVALID; 823 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 824 l2cap_le_finialize_channel_close(channel); // -- remove from list 825 break; 826 default: 827 break; 828 } 829 } 830 831 // send l2cap con paramter update if necessary 832 hci_connections_get_iterator(&it); 833 while(btstack_linked_list_iterator_has_next(&it)){ 834 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 835 if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; 836 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 837 switch (connection->le_con_parameter_update_state){ 838 case CON_PARAMETER_UPDATE_SEND_REQUEST: 839 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 840 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, connection->le_con_param_update_identifier, 841 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 842 break; 843 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 844 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 845 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 846 break; 847 case CON_PARAMETER_UPDATE_DENY: 848 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 849 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 850 break; 851 default: 852 break; 853 } 854 } 855 #endif 856 857 // log_info("l2cap_run: exit"); 858 } 859 860 uint16_t l2cap_max_mtu(void){ 861 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 862 } 863 864 uint16_t l2cap_max_le_mtu(void){ 865 return l2cap_max_mtu(); 866 } 867 868 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 869 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 870 log_info("l2cap_handle_connection_complete expected state"); 871 // success, start l2cap handshake 872 channel->con_handle = con_handle; 873 // check remote SSP feature first 874 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 875 } 876 } 877 878 #ifdef ENABLE_BLE 879 static void l2cap_handle_le_connection_complete(l2cap_channel_t * channel, uint8_t status, hci_con_handle_t con_handle){ 880 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 881 log_info("l2cap_le_handle_connection_complete expected state"); 882 // TODO: bail if status != 0 883 884 // success, start l2cap handshake 885 channel->con_handle = con_handle; 886 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 887 } 888 } 889 #endif 890 891 892 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 893 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 894 895 // we have been waiting for remote supported features, if both support SSP, 896 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)); 897 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 898 // request security level 2 899 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 900 gap_request_security_level(channel->con_handle, LEVEL_2); 901 return; 902 } 903 // fine, go ahead 904 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 905 } 906 907 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 908 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 909 910 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 911 if (!channel) { 912 return NULL; 913 } 914 915 // Init memory (make valgrind happy) 916 memset(channel, 0, sizeof(l2cap_channel_t)); 917 918 // fill in 919 channel->packet_handler = packet_handler; 920 bd_addr_copy(channel->address, address); 921 channel->address_type = address_type; 922 channel->psm = psm; 923 channel->local_mtu = local_mtu; 924 channel->remote_mtu = L2CAP_MINIMAL_MTU; 925 channel->required_security_level = security_level; 926 927 // 928 channel->local_cid = l2cap_next_local_cid(); 929 channel->con_handle = 0; 930 931 // set initial state 932 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 933 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 934 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 935 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 936 return channel; 937 } 938 939 /** 940 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 941 * @param packet_handler 942 * @param address 943 * @param psm 944 * @param mtu 945 * @param local_cid 946 */ 947 948 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){ 949 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, local_mtu); 950 951 if (local_mtu > l2cap_max_mtu()) { 952 local_mtu = l2cap_max_mtu(); 953 } 954 955 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 956 if (!channel) { 957 return BTSTACK_MEMORY_ALLOC_FAILED; 958 } 959 960 // add to connections list 961 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 962 963 // store local_cid 964 if (out_local_cid){ 965 *out_local_cid = channel->local_cid; 966 } 967 968 // check if hci connection is already usable 969 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 970 if (conn){ 971 log_info("l2cap_create_channel, hci connection already exists"); 972 l2cap_handle_connection_complete(conn->con_handle, channel); 973 // check if remote supported fearures are already received 974 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 975 l2cap_handle_remote_supported_features_received(channel); 976 } 977 } 978 979 l2cap_run(); 980 981 return 0; 982 } 983 984 void 985 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 986 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 987 // find channel for local_cid 988 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 989 if (channel) { 990 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 991 } 992 // process 993 l2cap_run(); 994 } 995 996 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 997 btstack_linked_list_iterator_t it; 998 btstack_linked_list_iterator_init(&it, &l2cap_channels); 999 while (btstack_linked_list_iterator_has_next(&it)){ 1000 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1001 if ( bd_addr_cmp( channel->address, address) != 0) continue; 1002 // channel for this address found 1003 switch (channel->state){ 1004 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 1005 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1006 // failure, forward error code 1007 l2cap_emit_channel_opened(channel, status); 1008 // discard channel 1009 l2cap_stop_rtx(channel); 1010 btstack_linked_list_iterator_remove(&it); 1011 btstack_memory_l2cap_channel_free(channel); 1012 break; 1013 default: 1014 break; 1015 } 1016 } 1017 } 1018 1019 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1020 btstack_linked_list_iterator_t it; 1021 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1022 while (btstack_linked_list_iterator_has_next(&it)){ 1023 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1024 if ( ! bd_addr_cmp( channel->address, address) ){ 1025 l2cap_handle_connection_complete(handle, channel); 1026 } 1027 } 1028 // process 1029 l2cap_run(); 1030 } 1031 1032 static void l2cap_notify_channel_can_send(void){ 1033 btstack_linked_list_iterator_t it; 1034 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1035 while (btstack_linked_list_iterator_has_next(&it)){ 1036 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1037 if (!channel->waiting_for_can_send_now) continue; 1038 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1039 channel->waiting_for_can_send_now = 0; 1040 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1041 } 1042 1043 int i; 1044 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1045 if (!fixed_channels[i].callback) continue; 1046 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1047 int can_send; 1048 if (l2cap_fixed_channel_table_index_is_le(i)){ 1049 can_send = hci_can_send_acl_le_packet_now(); 1050 } else { 1051 can_send = hci_can_send_acl_classic_packet_now(); 1052 } 1053 if (!can_send) continue; 1054 fixed_channels[i].waiting_for_can_send_now = 0; 1055 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1056 } 1057 } 1058 1059 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1060 1061 bd_addr_t address; 1062 hci_con_handle_t handle; 1063 btstack_linked_list_iterator_t it; 1064 int hci_con_used; 1065 1066 switch(hci_event_packet_get_type(packet)){ 1067 1068 // handle connection complete events 1069 case HCI_EVENT_CONNECTION_COMPLETE: 1070 reverse_bd_addr(&packet[5], address); 1071 if (packet[2] == 0){ 1072 handle = little_endian_read_16(packet, 3); 1073 l2cap_handle_connection_success_for_addr(address, handle); 1074 } else { 1075 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1076 } 1077 break; 1078 1079 // handle successful create connection cancel command 1080 case HCI_EVENT_COMMAND_COMPLETE: 1081 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1082 if (packet[5] == 0){ 1083 reverse_bd_addr(&packet[6], address); 1084 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1085 l2cap_handle_connection_failed_for_addr(address, 0x16); 1086 } 1087 } 1088 l2cap_run(); // try sending signaling packets first 1089 break; 1090 1091 case HCI_EVENT_COMMAND_STATUS: 1092 l2cap_run(); // try sending signaling packets first 1093 break; 1094 1095 // handle disconnection complete events 1096 case HCI_EVENT_DISCONNECTION_COMPLETE: 1097 // send l2cap disconnect events for all channels on this handle and free them 1098 handle = little_endian_read_16(packet, 3); 1099 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1100 while (btstack_linked_list_iterator_has_next(&it)){ 1101 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1102 if (channel->con_handle != handle) continue; 1103 l2cap_emit_channel_closed(channel); 1104 l2cap_stop_rtx(channel); 1105 btstack_linked_list_iterator_remove(&it); 1106 btstack_memory_l2cap_channel_free(channel); 1107 } 1108 #ifdef ENABLE_BLE 1109 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1110 while (btstack_linked_list_iterator_has_next(&it)){ 1111 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1112 if (channel->con_handle != handle) continue; 1113 l2cap_emit_channel_closed(channel); 1114 btstack_linked_list_iterator_remove(&it); 1115 btstack_memory_l2cap_channel_free(channel); 1116 } 1117 #endif 1118 break; 1119 1120 // Notify channel packet handler if they can send now 1121 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1122 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1123 l2cap_run(); // try sending signaling packets first 1124 l2cap_notify_channel_can_send(); 1125 break; 1126 1127 // HCI Connection Timeouts 1128 case L2CAP_EVENT_TIMEOUT_CHECK: 1129 handle = little_endian_read_16(packet, 2); 1130 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1131 if (hci_authentication_active_for_handle(handle)) break; 1132 hci_con_used = 0; 1133 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1134 while (btstack_linked_list_iterator_has_next(&it)){ 1135 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1136 if (channel->con_handle != handle) continue; 1137 hci_con_used = 1; 1138 break; 1139 } 1140 if (hci_con_used) break; 1141 if (!hci_can_send_command_packet_now()) break; 1142 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1143 break; 1144 1145 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1146 handle = little_endian_read_16(packet, 3); 1147 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1148 while (btstack_linked_list_iterator_has_next(&it)){ 1149 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1150 if (channel->con_handle != handle) continue; 1151 l2cap_handle_remote_supported_features_received(channel); 1152 break; 1153 } 1154 break; 1155 1156 #ifdef ENABLE_BLE 1157 case HCI_EVENT_LE_META: 1158 switch (packet[2]){ 1159 int addr_type; 1160 l2cap_channel_t * channel; 1161 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 1162 // Connection management 1163 reverse_bd_addr(&packet[8], address); 1164 addr_type = (bd_addr_type_t)packet[7]; 1165 log_info("L2CAP - LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(address)); 1166 // get l2cap_channel 1167 // also pass in status 1168 channel = l2cap_get_le_channel_for_address_and_addr_type(address, addr_type); 1169 if (!channel) break; 1170 l2cap_handle_le_connection_complete(channel, packet[3], little_endian_read_16(packet, 4)); 1171 break; 1172 default: 1173 break; 1174 } 1175 break; 1176 #endif 1177 1178 case GAP_EVENT_SECURITY_LEVEL: 1179 handle = little_endian_read_16(packet, 2); 1180 log_info("l2cap - security level update"); 1181 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1182 while (btstack_linked_list_iterator_has_next(&it)){ 1183 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1184 if (channel->con_handle != handle) continue; 1185 1186 log_info("l2cap - state %u", channel->state); 1187 1188 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1189 gap_security_level_t required_level = channel->required_security_level; 1190 1191 switch (channel->state){ 1192 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1193 if (actual_level >= required_level){ 1194 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1195 l2cap_emit_connection_request(channel); 1196 } else { 1197 channel->reason = 0x0003; // security block 1198 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1199 } 1200 break; 1201 1202 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1203 if (actual_level >= required_level){ 1204 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1205 } else { 1206 // disconnnect, authentication not good enough 1207 hci_disconnect_security_block(handle); 1208 } 1209 break; 1210 1211 default: 1212 break; 1213 } 1214 } 1215 break; 1216 1217 default: 1218 break; 1219 } 1220 1221 l2cap_run(); 1222 } 1223 1224 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1225 channel->remote_sig_id = identifier; 1226 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1227 l2cap_run(); 1228 } 1229 1230 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 1231 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1232 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1233 signaling_responses[signaling_responses_pending].handle = handle; 1234 signaling_responses[signaling_responses_pending].code = code; 1235 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1236 signaling_responses[signaling_responses_pending].data = data; 1237 signaling_responses_pending++; 1238 l2cap_run(); 1239 } 1240 } 1241 1242 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1243 1244 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1245 l2cap_service_t *service = l2cap_get_service(psm); 1246 if (!service) { 1247 // 0x0002 PSM not supported 1248 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 1249 return; 1250 } 1251 1252 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1253 if (!hci_connection) { 1254 // 1255 log_error("no hci_connection for handle %u", handle); 1256 return; 1257 } 1258 1259 // alloc structure 1260 // log_info("l2cap_handle_connection_request register channel"); 1261 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 1262 psm, service->mtu, service->required_security_level); 1263 if (!channel){ 1264 // 0x0004 No resources available 1265 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 1266 return; 1267 } 1268 1269 channel->con_handle = handle; 1270 channel->remote_cid = source_cid; 1271 channel->remote_sig_id = sig_id; 1272 1273 // limit local mtu to max acl packet length - l2cap header 1274 if (channel->local_mtu > l2cap_max_mtu()) { 1275 channel->local_mtu = l2cap_max_mtu(); 1276 } 1277 1278 // set initial state 1279 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1280 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 1281 1282 // add to connections list 1283 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1284 1285 // assert security requirements 1286 gap_request_security_level(handle, channel->required_security_level); 1287 } 1288 1289 void l2cap_accept_connection(uint16_t local_cid){ 1290 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1291 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1292 if (!channel) { 1293 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1294 return; 1295 } 1296 1297 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1298 1299 // process 1300 l2cap_run(); 1301 } 1302 1303 void l2cap_decline_connection(uint16_t local_cid){ 1304 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 1305 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1306 if (!channel) { 1307 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1308 return; 1309 } 1310 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1311 channel->reason = 0x04; // no resources available 1312 l2cap_run(); 1313 } 1314 1315 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1316 1317 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1318 1319 uint16_t flags = little_endian_read_16(command, 6); 1320 if (flags & 1) { 1321 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1322 } 1323 1324 // accept the other's configuration options 1325 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1326 uint16_t pos = 8; 1327 while (pos < end_pos){ 1328 uint8_t option_hint = command[pos] >> 7; 1329 uint8_t option_type = command[pos] & 0x7f; 1330 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1331 pos++; 1332 uint8_t length = command[pos++]; 1333 // MTU { type(8): 1, len(8):2, MTU(16) } 1334 if (option_type == 1 && length == 2){ 1335 channel->remote_mtu = little_endian_read_16(command, pos); 1336 // log_info("l2cap cid 0x%02x, remote mtu %u", channel->local_cid, channel->remote_mtu); 1337 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1338 } 1339 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1340 if (option_type == 2 && length == 2){ 1341 channel->flush_timeout = little_endian_read_16(command, pos); 1342 } 1343 // check for unknown options 1344 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1345 log_info("l2cap cid %u, unknown options", channel->local_cid); 1346 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1347 } 1348 pos += length; 1349 } 1350 } 1351 1352 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1353 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1354 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1355 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1356 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 1357 if (channel->state == L2CAP_STATE_OPEN) return 0; 1358 return 1; 1359 } 1360 1361 1362 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1363 1364 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1365 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1366 uint16_t result = 0; 1367 1368 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1369 1370 // handle DISCONNECT REQUESTS seperately 1371 if (code == DISCONNECTION_REQUEST){ 1372 switch (channel->state){ 1373 case L2CAP_STATE_CONFIG: 1374 case L2CAP_STATE_OPEN: 1375 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1376 case L2CAP_STATE_WAIT_DISCONNECT: 1377 l2cap_handle_disconnect_request(channel, identifier); 1378 break; 1379 1380 default: 1381 // ignore in other states 1382 break; 1383 } 1384 return; 1385 } 1386 1387 // @STATEMACHINE(l2cap) 1388 switch (channel->state) { 1389 1390 case L2CAP_STATE_WAIT_CONNECT_RSP: 1391 switch (code){ 1392 case CONNECTION_RESPONSE: 1393 l2cap_stop_rtx(channel); 1394 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1395 switch (result) { 1396 case 0: 1397 // successful connection 1398 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1399 channel->state = L2CAP_STATE_CONFIG; 1400 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1401 break; 1402 case 1: 1403 // connection pending. get some coffee, but start the ERTX 1404 l2cap_start_ertx(channel); 1405 break; 1406 default: 1407 // channel closed 1408 channel->state = L2CAP_STATE_CLOSED; 1409 // map l2cap connection response result to BTstack status enumeration 1410 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1411 1412 // drop link key if security block 1413 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1414 gap_drop_link_key_for_bd_addr(channel->address); 1415 } 1416 1417 // discard channel 1418 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1419 btstack_memory_l2cap_channel_free(channel); 1420 break; 1421 } 1422 break; 1423 1424 default: 1425 //@TODO: implement other signaling packets 1426 break; 1427 } 1428 break; 1429 1430 case L2CAP_STATE_CONFIG: 1431 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1432 switch (code) { 1433 case CONFIGURE_REQUEST: 1434 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1435 l2cap_signaling_handle_configure_request(channel, command); 1436 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1437 // only done if continuation not set 1438 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1439 } 1440 break; 1441 case CONFIGURE_RESPONSE: 1442 l2cap_stop_rtx(channel); 1443 switch (result){ 1444 case 0: // success 1445 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1446 break; 1447 case 4: // pending 1448 l2cap_start_ertx(channel); 1449 break; 1450 default: 1451 // retry on negative result 1452 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1453 break; 1454 } 1455 break; 1456 default: 1457 break; 1458 } 1459 if (l2cap_channel_ready_for_open(channel)){ 1460 // for open: 1461 channel->state = L2CAP_STATE_OPEN; 1462 l2cap_emit_channel_opened(channel, 0); 1463 } 1464 break; 1465 1466 case L2CAP_STATE_WAIT_DISCONNECT: 1467 switch (code) { 1468 case DISCONNECTION_RESPONSE: 1469 l2cap_finialize_channel_close(channel); 1470 break; 1471 default: 1472 //@TODO: implement other signaling packets 1473 break; 1474 } 1475 break; 1476 1477 case L2CAP_STATE_CLOSED: 1478 // @TODO handle incoming requests 1479 break; 1480 1481 case L2CAP_STATE_OPEN: 1482 //@TODO: implement other signaling packets, e.g. re-configure 1483 break; 1484 default: 1485 break; 1486 } 1487 // log_info("new state %u", channel->state); 1488 } 1489 1490 1491 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1492 1493 // get code, signalind identifier and command len 1494 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1495 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1496 1497 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1498 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1499 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1500 return; 1501 } 1502 1503 // general commands without an assigned channel 1504 switch(code) { 1505 1506 case CONNECTION_REQUEST: { 1507 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1508 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1509 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1510 return; 1511 } 1512 1513 case ECHO_REQUEST: 1514 l2cap_register_signaling_response(handle, code, sig_id, 0); 1515 return; 1516 1517 case INFORMATION_REQUEST: { 1518 uint16_t infoType = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1519 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1520 return; 1521 } 1522 1523 default: 1524 break; 1525 } 1526 1527 1528 // Get potential destination CID 1529 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1530 1531 // Find channel for this sig_id and connection handle 1532 btstack_linked_list_iterator_t it; 1533 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1534 while (btstack_linked_list_iterator_has_next(&it)){ 1535 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1536 if (channel->con_handle != handle) continue; 1537 if (code & 1) { 1538 // match odd commands (responses) by previous signaling identifier 1539 if (channel->local_sig_id == sig_id) { 1540 l2cap_signaling_handler_channel(channel, command); 1541 break; 1542 } 1543 } else { 1544 // match even commands (requests) by local channel id 1545 if (channel->local_cid == dest_cid) { 1546 l2cap_signaling_handler_channel(channel, command); 1547 break; 1548 } 1549 } 1550 } 1551 } 1552 1553 #ifdef ENABLE_BLE 1554 // @returns valid 1555 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 1556 hci_connection_t * connection; 1557 uint16_t result; 1558 uint8_t event[10]; 1559 uint16_t le_psm; 1560 uint16_t local_cid; 1561 uint16_t credits; 1562 l2cap_service_t * service; 1563 l2cap_channel_t * channel; 1564 btstack_linked_list_iterator_t it; 1565 1566 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1567 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 1568 1569 switch (code){ 1570 1571 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 1572 result = little_endian_read_16(command, 4); 1573 l2cap_emit_connection_parameter_update_response(handle, result); 1574 break; 1575 1576 case CONNECTION_PARAMETER_UPDATE_REQUEST: 1577 connection = hci_connection_for_handle(handle); 1578 if (connection){ 1579 if (connection->role != HCI_ROLE_MASTER){ 1580 // reject command without notifying upper layer when not in master role 1581 return 0; 1582 } 1583 int update_parameter = 1; 1584 le_connection_parameter_range_t existing_range; 1585 gap_get_connection_parameter_range(&existing_range); 1586 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 1587 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 1588 uint16_t le_conn_latency = little_endian_read_16(command,12); 1589 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 1590 1591 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 1592 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 1593 1594 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 1595 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 1596 1597 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 1598 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 1599 1600 if (update_parameter){ 1601 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 1602 connection->le_conn_interval_min = le_conn_interval_min; 1603 connection->le_conn_interval_max = le_conn_interval_max; 1604 connection->le_conn_latency = le_conn_latency; 1605 connection->le_supervision_timeout = le_supervision_timeout; 1606 } else { 1607 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 1608 } 1609 connection->le_con_param_update_identifier = sig_id; 1610 } 1611 1612 if (!l2cap_event_packet_handler) break; 1613 1614 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 1615 event[1] = 8; 1616 memcpy(&event[2], &command[4], 8); 1617 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1618 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1619 break; 1620 1621 case LE_CREDIT_BASED_CONNECTION_REQUEST: 1622 1623 // get hci connection, bail if not found (must not happen) 1624 connection = hci_connection_for_handle(handle); 1625 if (!connection) return 0; 1626 1627 // check if service registered 1628 le_psm = little_endian_read_16(command, 4); 1629 service = l2cap_le_get_service(le_psm); 1630 1631 if (service){ 1632 1633 uint16_t source_cid = little_endian_read_16(command, 6); 1634 if (source_cid < 0x40){ 1635 // 0x0009 Connection refused - Invalid Source CID 1636 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0009); 1637 return 1; 1638 } 1639 1640 // go through list of channels for this ACL connection and check if we get a match 1641 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1642 while (btstack_linked_list_iterator_has_next(&it)){ 1643 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1644 if (a_channel->con_handle != handle) continue; 1645 if (a_channel->remote_cid != source_cid) continue; 1646 // 0x000a Connection refused - Source CID already allocated 1647 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x000a); 1648 return 1; 1649 } 1650 1651 // TODO: deal with authentication requirements, errors 0x005 - 000x8 1652 1653 // allocate channel 1654 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 1655 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 1656 if (!channel){ 1657 // 0x0004 Connection refused – no resources available 1658 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0004); 1659 return 1; 1660 } 1661 1662 channel->con_handle = handle; 1663 channel->remote_cid = source_cid; 1664 channel->remote_sig_id = sig_id; 1665 channel->remote_mtu = little_endian_read_16(command, 8); 1666 channel->remote_mps = little_endian_read_16(command, 10); 1667 channel->credits_outgoing = little_endian_read_16(command, 12); 1668 1669 // set initial state 1670 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1671 1672 // add to connections list 1673 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1674 1675 // post connection request event 1676 l2cap_emit_connection_request(channel); 1677 1678 } else { 1679 // Connection refused – LE_PSM not supported 1680 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0002); 1681 } 1682 break; 1683 1684 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 1685 // Find channel for this sig_id and connection handle 1686 channel = NULL; 1687 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1688 while (btstack_linked_list_iterator_has_next(&it)){ 1689 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1690 if (a_channel->con_handle != handle) continue; 1691 if (a_channel->local_sig_id != sig_id) continue; 1692 channel = a_channel; 1693 break; 1694 } 1695 if (!channel) break; 1696 1697 // cid + 0 1698 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 1699 if (result){ 1700 channel->state = L2CAP_STATE_CLOSED; 1701 // map l2cap connection response result to BTstack status enumeration 1702 l2cap_emit_channel_opened(channel, result); 1703 1704 // discard channel 1705 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1706 btstack_memory_l2cap_channel_free(channel); 1707 break; 1708 } 1709 1710 // success 1711 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1712 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1713 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 1714 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 1715 channel->state = L2CAP_STATE_OPEN; 1716 l2cap_emit_channel_opened(channel, result); 1717 break; 1718 1719 case LE_FLOW_CONTROL_CREDIT: 1720 // find channel 1721 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1722 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1723 if (!channel) break; 1724 credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1725 channel->credits_outgoing += credits; 1726 log_info("l2cap: %u credits for 0x%02x", credits, local_cid); 1727 break; 1728 1729 case DISCONNECTION_REQUEST: 1730 // find channel 1731 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1732 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1733 if (!channel) break; 1734 channel->remote_sig_id = sig_id; 1735 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1736 break; 1737 1738 default: 1739 // command unknown -> reject command 1740 return 0; 1741 } 1742 return 1; 1743 } 1744 #endif 1745 1746 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 1747 1748 // Get Channel ID 1749 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1750 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1751 1752 switch (channel_id) { 1753 1754 case L2CAP_CID_SIGNALING: { 1755 uint16_t command_offset = 8; 1756 while (command_offset < size) { 1757 // handle signaling commands 1758 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1759 1760 // increment command_offset 1761 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1762 } 1763 break; 1764 } 1765 1766 #ifdef ENABLE_BLE 1767 case L2CAP_CID_SIGNALING_LE: { 1768 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1769 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 1770 if (!valid){ 1771 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1772 } 1773 break; 1774 } 1775 #endif 1776 1777 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1778 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 1779 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1780 } 1781 break; 1782 1783 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1784 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 1785 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1786 } 1787 break; 1788 1789 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 1790 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 1791 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1792 } 1793 break; 1794 1795 default: { 1796 // Find channel for this channel_id and connection handle 1797 l2cap_channel_t * l2cap_channel; 1798 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 1799 if (l2cap_channel) { 1800 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1801 } 1802 #ifdef ENABLE_BLE 1803 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 1804 if (l2cap_channel) { 1805 // credit counting 1806 if (l2cap_channel->credits_incoming == 0){ 1807 log_error("LE Data Channel packet received but no incoming credits"); 1808 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1809 break; 1810 } 1811 l2cap_channel->credits_incoming--; 1812 1813 // automatic credits 1814 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 1815 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 1816 } 1817 1818 // first fragment 1819 uint16_t pos = 0; 1820 if (!l2cap_channel->receive_sdu_len){ 1821 l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 1822 l2cap_channel->receive_sdu_pos = 0; 1823 pos += 2; 1824 size -= 2; 1825 } 1826 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); 1827 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 1828 // done? 1829 log_debug("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 1830 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 1831 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 1832 l2cap_channel->receive_sdu_len = 0; 1833 } 1834 } 1835 #endif 1836 break; 1837 } 1838 } 1839 1840 l2cap_run(); 1841 } 1842 1843 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1844 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 1845 channel->state = L2CAP_STATE_CLOSED; 1846 l2cap_emit_channel_closed(channel); 1847 // discard channel 1848 l2cap_stop_rtx(channel); 1849 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1850 btstack_memory_l2cap_channel_free(channel); 1851 } 1852 1853 #ifdef ENABLE_BLE 1854 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1855 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 1856 channel->state = L2CAP_STATE_CLOSED; 1857 l2cap_emit_channel_closed(channel); 1858 // discard channel 1859 l2cap_stop_rtx(channel); 1860 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1861 btstack_memory_l2cap_channel_free(channel); 1862 } 1863 #endif 1864 1865 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 1866 btstack_linked_list_iterator_t it; 1867 btstack_linked_list_iterator_init(&it, services); 1868 while (btstack_linked_list_iterator_has_next(&it)){ 1869 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 1870 if ( service->psm == psm){ 1871 return service; 1872 }; 1873 } 1874 return NULL; 1875 } 1876 1877 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 1878 return l2cap_get_service_internal(&l2cap_services, psm); 1879 } 1880 1881 1882 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 1883 1884 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1885 1886 // check for alread registered psm 1887 l2cap_service_t *service = l2cap_get_service(psm); 1888 if (service) { 1889 log_error("l2cap_register_service: PSM %u already registered", psm); 1890 return L2CAP_SERVICE_ALREADY_REGISTERED; 1891 } 1892 1893 // alloc structure 1894 service = btstack_memory_l2cap_service_get(); 1895 if (!service) { 1896 log_error("l2cap_register_service: no memory for l2cap_service_t"); 1897 return BTSTACK_MEMORY_ALLOC_FAILED; 1898 } 1899 1900 // fill in 1901 service->psm = psm; 1902 service->mtu = mtu; 1903 service->packet_handler = service_packet_handler; 1904 service->required_security_level = security_level; 1905 1906 // add to services list 1907 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 1908 1909 // enable page scan 1910 gap_connectable_control(1); 1911 1912 return 0; 1913 } 1914 1915 uint8_t l2cap_unregister_service(uint16_t psm){ 1916 1917 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1918 1919 l2cap_service_t *service = l2cap_get_service(psm); 1920 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 1921 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 1922 btstack_memory_l2cap_service_free(service); 1923 1924 // disable page scan when no services registered 1925 if (btstack_linked_list_empty(&l2cap_services)) { 1926 gap_connectable_control(0); 1927 } 1928 return 0; 1929 } 1930 1931 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1932 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 1933 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 1934 if (index < 0) return; 1935 fixed_channels[index].callback = the_packet_handler; 1936 } 1937 1938 #ifdef ENABLE_BLE 1939 1940 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 1941 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 1942 } 1943 1944 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 1945 1946 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 1947 1948 // check for alread registered psm 1949 l2cap_service_t *service = l2cap_le_get_service(psm); 1950 if (service) { 1951 return L2CAP_SERVICE_ALREADY_REGISTERED; 1952 } 1953 1954 // alloc structure 1955 service = btstack_memory_l2cap_service_get(); 1956 if (!service) { 1957 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 1958 return BTSTACK_MEMORY_ALLOC_FAILED; 1959 } 1960 1961 // fill in 1962 service->psm = psm; 1963 service->mtu = 0; 1964 service->packet_handler = packet_handler; 1965 service->required_security_level = security_level; 1966 1967 // add to services list 1968 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 1969 1970 // done 1971 return 0; 1972 } 1973 1974 uint8_t l2cap_le_unregister_service(uint16_t psm) { 1975 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 1976 l2cap_service_t *service = l2cap_le_get_service(psm); 1977 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 1978 1979 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 1980 btstack_memory_l2cap_service_free(service); 1981 return 0; 1982 } 1983 1984 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 1985 // get channel 1986 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 1987 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 1988 1989 // validate state 1990 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 1991 return ERROR_CODE_COMMAND_DISALLOWED; 1992 } 1993 1994 // set state accept connection 1995 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 1996 channel->receive_sdu_buffer = receive_sdu_buffer; 1997 channel->local_mtu = mtu; 1998 channel->new_credits_incoming = initial_credits; 1999 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2000 2001 // test 2002 channel->new_credits_incoming = 1; 2003 2004 // go 2005 l2cap_run(); 2006 return 0; 2007 } 2008 2009 /** 2010 * @brief Deny incoming LE Data Channel connection due to resource constraints 2011 * @param local_cid L2CAP LE Data Channel Identifier 2012 */ 2013 2014 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 2015 // get channel 2016 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2017 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2018 2019 // validate state 2020 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2021 return ERROR_CODE_COMMAND_DISALLOWED; 2022 } 2023 2024 // set state decline connection 2025 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 2026 channel->reason = 0x04; // no resources available 2027 l2cap_run(); 2028 return 0; 2029 } 2030 2031 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 2032 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 2033 uint16_t * out_local_cid) { 2034 2035 log_info("L2CAP_LE_CREATE_CHANNEL addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 2036 2037 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, address, address_type, psm, mtu, security_level); 2038 if (!channel) { 2039 return BTSTACK_MEMORY_ALLOC_FAILED; 2040 } 2041 log_info("l2cap_le_create_channel %p", channel); 2042 2043 // store local_cid 2044 if (out_local_cid){ 2045 *out_local_cid = channel->local_cid; 2046 } 2047 2048 // provdide buffer 2049 channel->receive_sdu_buffer = receive_sdu_buffer; 2050 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 2051 channel->new_credits_incoming = initial_credits; 2052 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2053 2054 // test 2055 channel->new_credits_incoming = 1; 2056 2057 // add to connections list 2058 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2059 2060 // check if hci connection is already usable 2061 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, address_type); 2062 2063 if (conn){ 2064 log_info("l2cap_le_create_channel, hci connection already exists"); 2065 l2cap_handle_le_connection_complete(channel, 0, conn->con_handle); 2066 } else { 2067 2068 // 2069 // TODO: start timer 2070 // .. 2071 2072 // start connection 2073 uint8_t res = gap_auto_connection_start(address_type, address); 2074 if (res){ 2075 // discard channel object 2076 log_info("gap_auto_connection_start failed! 0x%02x", res); 2077 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2078 btstack_memory_l2cap_channel_free(channel); 2079 return res; 2080 } 2081 } 2082 return 0; 2083 } 2084 2085 /** 2086 * @brief Provide credtis for LE Data Channel 2087 * @param local_cid L2CAP LE Data Channel Identifier 2088 * @param credits Number additional credits for peer 2089 */ 2090 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 2091 // get channel 2092 // bail if missing 2093 // check state 2094 // check incoming credits + credits <= 0xffff 2095 // set credits_granted 2096 // l2cap_le_run() 2097 return 0; 2098 } 2099 2100 /** 2101 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 2102 * @param local_cid L2CAP LE Data Channel Identifier 2103 */ 2104 int l2cap_le_can_send_now(uint16_t local_cid){ 2105 // check if data can be sent via le at all 2106 return 0; 2107 } 2108 2109 /** 2110 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 2111 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 2112 * so packet handler should be ready to handle it 2113 * @param local_cid L2CAP LE Data Channel Identifier 2114 */ 2115 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 2116 // same as for non-le 2117 return 0; 2118 } 2119 2120 /** 2121 * @brief Send data via LE Data Channel 2122 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 2123 * @param local_cid L2CAP LE Data Channel Identifier 2124 * @param data data to send 2125 * @param size data size 2126 */ 2127 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 2128 2129 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2130 if (!channel) { 2131 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2132 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2133 } 2134 2135 if (len > channel->remote_mtu){ 2136 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 2137 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 2138 } 2139 2140 if (channel->send_sdu_buffer){ 2141 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 2142 return BTSTACK_ACL_BUFFERS_FULL; 2143 } 2144 2145 channel->send_sdu_buffer = data; 2146 channel->send_sdu_len = len; 2147 channel->send_sdu_pos = 0; 2148 2149 l2cap_run(); 2150 return 0; 2151 } 2152 2153 /** 2154 * @brief Disconnect from LE Data Channel 2155 * @param local_cid L2CAP LE Data Channel Identifier 2156 */ 2157 uint8_t l2cap_le_disconnect(uint16_t local_cid) 2158 { 2159 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2160 if (!channel) { 2161 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2162 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2163 } 2164 2165 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2166 l2cap_run(); 2167 return 0; 2168 } 2169 2170 #endif 2171