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 #define __BTSTACK_FILE__ "l2cap.c" 39 40 /* 41 * l2cap.c 42 * 43 * Logical Link Control and Adaption Protocl (L2CAP) 44 * 45 * Created by Matthias Ringwald on 5/16/09. 46 */ 47 48 #include "l2cap.h" 49 #include "hci.h" 50 #include "hci_dump.h" 51 #include "bluetooth_sdp.h" 52 #include "btstack_debug.h" 53 #include "btstack_event.h" 54 #include "btstack_memory.h" 55 56 #ifdef ENABLE_LE_DATA_CHANNELS 57 #include "ble/sm.h" 58 #endif 59 60 #include <stdarg.h> 61 #include <string.h> 62 63 #include <stdio.h> 64 65 // nr of buffered acl packets in outgoing queue to get max performance 66 #define NR_BUFFERED_ACL_PACKETS 3 67 68 // used to cache l2cap rejects, echo, and informational requests 69 #define NR_PENDING_SIGNALING_RESPONSES 3 70 71 // nr of credits provided to remote if credits fall below watermark 72 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK 5 73 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT 5 74 75 // offsets for L2CAP SIGNALING COMMANDS 76 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 77 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 78 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 79 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 80 81 // internal table 82 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL 0 83 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL 1 84 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL 2 85 #define L2CAP_FIXED_CHANNEL_TABLE_SIZE (L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL+1) 86 87 #if defined(ENABLE_LE_DATA_CHANNELS) || defined(ENABLE_CLASSIC) 88 #define L2CAP_USES_CHANNELS 89 #endif 90 91 // prototypes 92 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); 93 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ); 94 static void l2cap_notify_channel_can_send(void); 95 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel); 96 #ifdef ENABLE_CLASSIC 97 static void l2cap_finialize_channel_close(l2cap_channel_t *channel); 98 static inline l2cap_service_t * l2cap_get_service(uint16_t psm); 99 static void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status); 100 static void l2cap_emit_channel_closed(l2cap_channel_t *channel); 101 static void l2cap_emit_incoming_connection(l2cap_channel_t *channel); 102 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); 103 #endif 104 #ifdef ENABLE_LE_DATA_CHANNELS 105 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status); 106 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel); 107 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid); 108 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel); 109 static void l2cap_le_finialize_channel_close(l2cap_channel_t *channel); 110 static inline l2cap_service_t * l2cap_le_get_service(uint16_t psm); 111 #endif 112 113 typedef struct l2cap_fixed_channel { 114 btstack_packet_handler_t callback; 115 uint8_t waiting_for_can_send_now; 116 } l2cap_fixed_channel_t; 117 118 #ifdef ENABLE_CLASSIC 119 static btstack_linked_list_t l2cap_channels; 120 static btstack_linked_list_t l2cap_services; 121 static uint8_t require_security_level2_for_outgoing_sdp; 122 #endif 123 124 #ifdef ENABLE_LE_DATA_CHANNELS 125 static btstack_linked_list_t l2cap_le_channels; 126 static btstack_linked_list_t l2cap_le_services; 127 #endif 128 129 // used to cache l2cap rejects, echo, and informational requests 130 static l2cap_signaling_response_t signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; 131 static int signaling_responses_pending; 132 133 static btstack_packet_callback_registration_t hci_event_callback_registration; 134 static l2cap_fixed_channel_t fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_SIZE]; 135 136 #ifdef ENABLE_BLE 137 // only used for connection parameter update events 138 static btstack_packet_handler_t l2cap_event_packet_handler; 139 #endif 140 141 static uint16_t l2cap_fixed_channel_table_channel_id_for_index(int index){ 142 switch (index){ 143 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL: 144 return L2CAP_CID_ATTRIBUTE_PROTOCOL; 145 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL: 146 return L2CAP_CID_SECURITY_MANAGER_PROTOCOL; 147 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL: 148 return L2CAP_CID_CONNECTIONLESS_CHANNEL; 149 default: 150 return 0; 151 } 152 } 153 static int l2cap_fixed_channel_table_index_for_channel_id(uint16_t channel_id){ 154 switch (channel_id){ 155 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 156 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL; 157 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 158 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL; 159 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 160 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL; 161 default: 162 return -1; 163 } 164 } 165 166 static int l2cap_fixed_channel_table_index_is_le(int index){ 167 if (index == L2CAP_CID_CONNECTIONLESS_CHANNEL) return 0; 168 return 1; 169 } 170 171 void l2cap_init(void){ 172 signaling_responses_pending = 0; 173 174 #ifdef ENABLE_CLASSIC 175 l2cap_channels = NULL; 176 l2cap_services = NULL; 177 require_security_level2_for_outgoing_sdp = 0; 178 #endif 179 180 #ifdef ENABLE_LE_DATA_CHANNELS 181 l2cap_le_services = NULL; 182 l2cap_le_channels = NULL; 183 #endif 184 185 #ifdef ENABLE_BLE 186 l2cap_event_packet_handler = NULL; 187 #endif 188 memset(fixed_channels, 0, sizeof(fixed_channels)); 189 190 // 191 // register callback with HCI 192 // 193 hci_event_callback_registration.callback = &l2cap_hci_event_handler; 194 hci_add_event_handler(&hci_event_callback_registration); 195 196 hci_register_acl_packet_handler(&l2cap_acl_handler); 197 198 #ifdef ENABLE_CLASSIC 199 gap_connectable_control(0); // no services yet 200 #endif 201 } 202 203 void l2cap_register_packet_handler(void (*handler)(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 204 #ifdef ENABLE_BLE 205 l2cap_event_packet_handler = handler; 206 #else 207 UNUSED(handler); 208 #endif 209 } 210 211 void l2cap_request_can_send_fix_channel_now_event(hci_con_handle_t con_handle, uint16_t channel_id){ 212 UNUSED(con_handle); 213 214 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 215 if (index < 0) return; 216 fixed_channels[index].waiting_for_can_send_now = 1; 217 l2cap_notify_channel_can_send(); 218 } 219 220 int l2cap_can_send_fixed_channel_packet_now(hci_con_handle_t con_handle, uint16_t channel_id){ 221 UNUSED(channel_id); 222 223 return hci_can_send_acl_packet_now(con_handle); 224 } 225 226 uint8_t *l2cap_get_outgoing_buffer(void){ 227 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 228 } 229 230 int l2cap_reserve_packet_buffer(void){ 231 return hci_reserve_packet_buffer(); 232 } 233 234 void l2cap_release_packet_buffer(void){ 235 hci_release_packet_buffer(); 236 } 237 238 static void l2cap_setup_header(uint8_t * acl_buffer, hci_con_handle_t con_handle, uint8_t packet_boundary, uint16_t remote_cid, uint16_t len){ 239 // 0 - Connection handle : PB=pb : BC=00 240 little_endian_store_16(acl_buffer, 0, con_handle | (packet_boundary << 12) | (0 << 14)); 241 // 2 - ACL length 242 little_endian_store_16(acl_buffer, 2, len + 4); 243 // 4 - L2CAP packet length 244 little_endian_store_16(acl_buffer, 4, len + 0); 245 // 6 - L2CAP channel DEST 246 little_endian_store_16(acl_buffer, 6, remote_cid); 247 } 248 249 // assumption - only on LE connections 250 int l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len){ 251 252 if (!hci_is_packet_buffer_reserved()){ 253 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 254 return BTSTACK_ACL_BUFFERS_FULL; 255 } 256 257 if (!hci_can_send_prepared_acl_packet_now(con_handle)){ 258 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send", con_handle, cid); 259 return BTSTACK_ACL_BUFFERS_FULL; 260 } 261 262 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x", con_handle, cid); 263 264 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 265 l2cap_setup_header(acl_buffer, con_handle, 0, cid, len); 266 // send 267 return hci_send_acl_packet_buffer(len+8); 268 } 269 270 // assumption - only on LE connections 271 int l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len){ 272 273 if (!hci_can_send_acl_packet_now(con_handle)){ 274 log_info("l2cap_send cid 0x%02x, cannot send", cid); 275 return BTSTACK_ACL_BUFFERS_FULL; 276 } 277 278 hci_reserve_packet_buffer(); 279 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 280 281 memcpy(&acl_buffer[8], data, len); 282 283 return l2cap_send_prepared_connectionless(con_handle, cid, len); 284 } 285 286 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel) { 287 log_debug("L2CAP_EVENT_CHANNEL_CAN_SEND_NOW local_cid 0x%x", channel); 288 uint8_t event[4]; 289 event[0] = L2CAP_EVENT_CAN_SEND_NOW; 290 event[1] = sizeof(event) - 2; 291 little_endian_store_16(event, 2, channel); 292 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 293 packet_handler(HCI_EVENT_PACKET, channel, event, sizeof(event)); 294 } 295 296 #ifdef L2CAP_USES_CHANNELS 297 static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 298 (* (channel->packet_handler))(type, channel->local_cid, data, size); 299 } 300 301 static void l2cap_emit_simple_event_with_cid(l2cap_channel_t * channel, uint8_t event_code){ 302 uint8_t event[4]; 303 event[0] = event_code; 304 event[1] = sizeof(event) - 2; 305 little_endian_store_16(event, 2, channel->local_cid); 306 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 307 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 308 } 309 #endif 310 311 #ifdef ENABLE_CLASSIC 312 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 313 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", 314 status, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 315 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 316 uint8_t event[24]; 317 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 318 event[1] = sizeof(event) - 2; 319 event[2] = status; 320 reverse_bd_addr(channel->address, &event[3]); 321 little_endian_store_16(event, 9, channel->con_handle); 322 little_endian_store_16(event, 11, channel->psm); 323 little_endian_store_16(event, 13, channel->local_cid); 324 little_endian_store_16(event, 15, channel->remote_cid); 325 little_endian_store_16(event, 17, channel->local_mtu); 326 little_endian_store_16(event, 19, channel->remote_mtu); 327 little_endian_store_16(event, 21, channel->flush_timeout); 328 event[23] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 329 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 330 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 331 } 332 333 static void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 334 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 335 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 336 } 337 338 static void l2cap_emit_incoming_connection(l2cap_channel_t *channel) { 339 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 340 bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid); 341 uint8_t event[16]; 342 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 343 event[1] = sizeof(event) - 2; 344 reverse_bd_addr(channel->address, &event[2]); 345 little_endian_store_16(event, 8, channel->con_handle); 346 little_endian_store_16(event, 10, channel->psm); 347 little_endian_store_16(event, 12, channel->local_cid); 348 little_endian_store_16(event, 14, channel->remote_cid); 349 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 350 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 351 } 352 353 static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 354 btstack_linked_list_iterator_t it; 355 btstack_linked_list_iterator_init(&it, &l2cap_channels); 356 while (btstack_linked_list_iterator_has_next(&it)){ 357 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 358 if ( channel->local_cid == local_cid) { 359 return channel; 360 } 361 } 362 return NULL; 363 } 364 365 /// 366 367 void l2cap_request_can_send_now_event(uint16_t local_cid){ 368 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 369 if (!channel) return; 370 channel->waiting_for_can_send_now = 1; 371 l2cap_notify_channel_can_send(); 372 } 373 374 int l2cap_can_send_packet_now(uint16_t local_cid){ 375 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 376 if (!channel) return 0; 377 return hci_can_send_acl_packet_now(channel->con_handle); 378 } 379 380 int l2cap_can_send_prepared_packet_now(uint16_t local_cid){ 381 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 382 if (!channel) return 0; 383 return hci_can_send_prepared_acl_packet_now(channel->con_handle); 384 } 385 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 386 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 387 if (channel) { 388 return channel->remote_mtu; 389 } 390 return 0; 391 } 392 393 static l2cap_channel_t * l2cap_channel_for_rtx_timer(btstack_timer_source_t * ts){ 394 btstack_linked_list_iterator_t it; 395 btstack_linked_list_iterator_init(&it, &l2cap_channels); 396 while (btstack_linked_list_iterator_has_next(&it)){ 397 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 398 if ( &channel->rtx == ts) { 399 return channel; 400 } 401 } 402 return NULL; 403 } 404 405 static void l2cap_rtx_timeout(btstack_timer_source_t * ts){ 406 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 407 if (!channel) return; 408 409 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 410 411 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 412 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 413 // notify client 414 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 415 416 // discard channel 417 // no need to stop timer here, it is removed from list during timer callback 418 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 419 btstack_memory_l2cap_channel_free(channel); 420 } 421 422 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 423 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 424 btstack_run_loop_remove_timer(&channel->rtx); 425 } 426 427 static void l2cap_start_rtx(l2cap_channel_t * channel){ 428 l2cap_stop_rtx(channel); 429 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 430 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 431 btstack_run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 432 btstack_run_loop_add_timer(&channel->rtx); 433 } 434 435 static void l2cap_start_ertx(l2cap_channel_t * channel){ 436 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 437 l2cap_stop_rtx(channel); 438 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 439 btstack_run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 440 btstack_run_loop_add_timer(&channel->rtx); 441 } 442 443 void l2cap_require_security_level_2_for_outgoing_sdp(void){ 444 require_security_level2_for_outgoing_sdp = 1; 445 } 446 447 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 448 return (psm == BLUETOOTH_PROTOCOL_SDP) && (!require_security_level2_for_outgoing_sdp); 449 } 450 451 static int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 452 if (!hci_can_send_acl_packet_now(handle)){ 453 log_info("l2cap_send_signaling_packet, cannot send"); 454 return BTSTACK_ACL_BUFFERS_FULL; 455 } 456 457 // log_info("l2cap_send_signaling_packet type %u", cmd); 458 hci_reserve_packet_buffer(); 459 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 460 va_list argptr; 461 va_start(argptr, identifier); 462 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 463 va_end(argptr); 464 // log_info("l2cap_send_signaling_packet con %u!", handle); 465 return hci_send_acl_packet_buffer(len); 466 } 467 468 // assumption - only on Classic connections 469 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 470 471 if (!hci_is_packet_buffer_reserved()){ 472 log_error("l2cap_send_prepared called without reserving packet first"); 473 return BTSTACK_ACL_BUFFERS_FULL; 474 } 475 476 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 477 if (!channel) { 478 log_error("l2cap_send_prepared no channel for cid 0x%02x", local_cid); 479 return -1; // TODO: define error 480 } 481 482 if (!hci_can_send_prepared_acl_packet_now(channel->con_handle)){ 483 log_info("l2cap_send_prepared cid 0x%02x, cannot send", local_cid); 484 return BTSTACK_ACL_BUFFERS_FULL; 485 } 486 487 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used", local_cid, channel->con_handle); 488 489 // set non-flushable packet boundary flag if supported on Controller 490 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 491 uint8_t packet_boundary_flag = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 492 l2cap_setup_header(acl_buffer, channel->con_handle, packet_boundary_flag, channel->remote_cid, len); 493 // send 494 return hci_send_acl_packet_buffer(len+8); 495 } 496 497 // assumption - only on Classic connections 498 int l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len){ 499 500 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 501 if (!channel) { 502 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 503 return -1; // TODO: define error 504 } 505 506 if (len > channel->remote_mtu){ 507 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 508 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 509 } 510 511 if (!hci_can_send_acl_packet_now(channel->con_handle)){ 512 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 513 return BTSTACK_ACL_BUFFERS_FULL; 514 } 515 516 hci_reserve_packet_buffer(); 517 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 518 519 memcpy(&acl_buffer[8], data, len); 520 521 return l2cap_send_prepared(local_cid, len); 522 } 523 524 int l2cap_send_echo_request(hci_con_handle_t con_handle, uint8_t *data, uint16_t len){ 525 return l2cap_send_signaling_packet(con_handle, ECHO_REQUEST, 0x77, len, data); 526 } 527 528 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 529 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 530 } 531 532 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 533 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 534 } 535 #endif 536 537 538 #ifdef ENABLE_BLE 539 static int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 540 541 if (!hci_can_send_acl_packet_now(handle)){ 542 log_info("l2cap_send_le_signaling_packet, cannot send"); 543 return BTSTACK_ACL_BUFFERS_FULL; 544 } 545 546 // log_info("l2cap_send_le_signaling_packet type %u", cmd); 547 hci_reserve_packet_buffer(); 548 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 549 va_list argptr; 550 va_start(argptr, identifier); 551 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 552 va_end(argptr); 553 // log_info("l2cap_send_le_signaling_packet con %u!", handle); 554 return hci_send_acl_packet_buffer(len); 555 } 556 #endif 557 558 uint16_t l2cap_max_mtu(void){ 559 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 560 } 561 562 uint16_t l2cap_max_le_mtu(void){ 563 return l2cap_max_mtu(); 564 } 565 566 static uint16_t l2cap_setup_options(l2cap_channel_t * channel, uint8_t * config_options){ 567 int send_retransmission_and_flow_control_option = 0; 568 int options_size; 569 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 570 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 571 send_retransmission_and_flow_control_option = 1; 572 } 573 #endif 574 if (send_retransmission_and_flow_control_option){ 575 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 576 config_options[0] = 0x04; // RETRANSMISSION AND FLOW CONTROL OPTION 577 config_options[1] = 9; // length 578 config_options[2] = (uint8_t) channel->mode; 579 config_options[3] = 1; // TxWindows size 580 config_options[4] = 1; // max retransmit 581 little_endian_store_16( config_options, 5, 100); // Retransmission timeout: 100 ms 582 little_endian_store_16( config_options, 7, 300); // Monitor timeout: 300 ms 583 little_endian_store_16( config_options, 9, channel->local_mtu); // Max PDU size // TODO: use real MTU 584 options_size = 11; 585 #endif 586 } else { 587 config_options[0] = 1; // MTU 588 config_options[1] = 2; // len param 589 little_endian_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 590 options_size = 4; 591 } 592 return options_size; 593 } 594 595 static uint32_t l2cap_extended_features_mask(void){ 596 // extended features request supported, features: fixed channels, unicast connectionless data reception 597 uint32_t features = 0x280; 598 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 599 features |= 0x0008; 600 #endif 601 return features; 602 } 603 604 // MARK: L2CAP_RUN 605 // process outstanding signaling tasks 606 static void l2cap_run(void){ 607 608 // log_info("l2cap_run: entered"); 609 610 // check pending signaling responses 611 while (signaling_responses_pending){ 612 613 hci_con_handle_t handle = signaling_responses[0].handle; 614 615 if (!hci_can_send_acl_packet_now(handle)) break; 616 617 uint8_t sig_id = signaling_responses[0].sig_id; 618 uint8_t response_code = signaling_responses[0].code; 619 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 620 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 621 #ifdef ENABLE_CLASSIC 622 uint16_t source_cid = signaling_responses[0].cid; // CONNECTION_REQUEST 623 #endif 624 UNUSED(infoType); 625 626 // remove first item before sending (to avoid sending response mutliple times) 627 signaling_responses_pending--; 628 int i; 629 for (i=0; i < signaling_responses_pending; i++){ 630 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 631 } 632 633 switch (response_code){ 634 #ifdef ENABLE_CLASSIC 635 case CONNECTION_REQUEST: 636 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, source_cid, 0, result, 0); 637 // also disconnect if result is 0x0003 - security blocked 638 if (result == 0x0003){ 639 hci_disconnect_security_block(handle); 640 } 641 break; 642 case ECHO_REQUEST: 643 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 644 break; 645 case INFORMATION_REQUEST: 646 switch (infoType){ 647 case 1: { // Connectionless MTU 648 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 649 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 650 } 651 break; 652 case 2: { // Extended Features Supported 653 uint32_t features = l2cap_extended_features_mask(); 654 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 655 } 656 break; 657 case 3: { // Fixed Channels Supported 658 uint8_t map[8]; 659 memset(map, 0, 8); 660 map[0] = 0x06; // L2CAP Signaling Channel (0x02) + Connectionless reception (0x04) 661 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 662 } 663 break; 664 default: 665 // all other types are not supported 666 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 667 break; 668 } 669 break; 670 case COMMAND_REJECT: 671 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 672 break; 673 #endif 674 #ifdef ENABLE_BLE 675 case LE_CREDIT_BASED_CONNECTION_REQUEST: 676 l2cap_send_le_signaling_packet(handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, sig_id, 0, 0, 0, 0, result); 677 break; 678 case COMMAND_REJECT_LE: 679 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 680 break; 681 #endif 682 default: 683 // should not happen 684 break; 685 } 686 } 687 688 btstack_linked_list_iterator_t it; 689 UNUSED(it); 690 691 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 692 // send l2cap information request if neccessary 693 hci_connections_get_iterator(&it); 694 while(btstack_linked_list_iterator_has_next(&it)){ 695 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 696 if (connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST){ 697 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W4_EXTENDED_FEATURE_RESPONSE; 698 // send information request for extended features 699 uint8_t sig_id = l2cap_next_sig_id(); 700 uint8_t info_type = 2; 701 l2cap_send_signaling_packet(connection->con_handle, INFORMATION_REQUEST, sig_id, info_type); 702 return; 703 } 704 } 705 #endif 706 707 #ifdef ENABLE_CLASSIC 708 uint8_t config_options[10]; 709 btstack_linked_list_iterator_init(&it, &l2cap_channels); 710 while (btstack_linked_list_iterator_has_next(&it)){ 711 712 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 713 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 714 switch (channel->state){ 715 716 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 717 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 718 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 719 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 720 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 721 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 722 } 723 break; 724 725 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 726 if (!hci_can_send_command_packet_now()) break; 727 // send connection request - set state first 728 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 729 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 730 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 731 break; 732 733 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 734 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 735 channel->state = L2CAP_STATE_INVALID; 736 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 737 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 738 l2cap_stop_rtx(channel); 739 btstack_linked_list_iterator_remove(&it); 740 btstack_memory_l2cap_channel_free(channel); 741 break; 742 743 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 744 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 745 channel->state = L2CAP_STATE_CONFIG; 746 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 747 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 748 break; 749 750 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 751 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 752 // success, start l2cap handshake 753 channel->local_sig_id = l2cap_next_sig_id(); 754 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 755 l2cap_send_signaling_packet( channel->con_handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 756 l2cap_start_rtx(channel); 757 break; 758 759 case L2CAP_STATE_CONFIG: 760 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 761 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 762 uint16_t flags = 0; 763 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 764 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 765 flags = 1; 766 } else { 767 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 768 } 769 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 770 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 771 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 772 uint16_t options_size = l2cap_setup_options(channel, config_options); 773 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, options_size, &config_options); 774 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 775 } else { 776 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 777 } 778 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 779 } 780 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 781 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 782 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 783 channel->local_sig_id = l2cap_next_sig_id(); 784 uint16_t options_size = l2cap_setup_options(channel, config_options); 785 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, options_size, &config_options); 786 l2cap_start_rtx(channel); 787 } 788 if (l2cap_channel_ready_for_open(channel)){ 789 channel->state = L2CAP_STATE_OPEN; 790 l2cap_emit_channel_opened(channel, 0); // success 791 } 792 break; 793 794 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 795 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 796 channel->state = L2CAP_STATE_INVALID; 797 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 798 // 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 :) 799 l2cap_finialize_channel_close(channel); // -- remove from list 800 break; 801 802 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 803 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 804 channel->local_sig_id = l2cap_next_sig_id(); 805 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 806 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 807 break; 808 default: 809 break; 810 } 811 } 812 #endif 813 814 #ifdef ENABLE_LE_DATA_CHANNELS 815 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 816 while (btstack_linked_list_iterator_has_next(&it)){ 817 uint8_t * acl_buffer; 818 uint8_t * l2cap_payload; 819 uint16_t pos; 820 uint16_t payload_size; 821 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 822 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 823 switch (channel->state){ 824 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 825 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 826 channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; 827 // le psm, source cid, mtu, mps, initial credits 828 channel->local_sig_id = l2cap_next_sig_id(); 829 channel->credits_incoming = channel->new_credits_incoming; 830 channel->new_credits_incoming = 0; 831 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, channel->credits_incoming); 832 break; 833 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 834 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 835 // TODO: support larger MPS 836 channel->state = L2CAP_STATE_OPEN; 837 channel->credits_incoming = channel->new_credits_incoming; 838 channel->new_credits_incoming = 0; 839 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->local_mtu, 23, channel->credits_incoming, 0); 840 // notify client 841 l2cap_emit_le_channel_opened(channel, 0); 842 break; 843 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 844 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 845 channel->state = L2CAP_STATE_INVALID; 846 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, 0, 0, channel->reason); 847 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 848 l2cap_stop_rtx(channel); 849 btstack_linked_list_iterator_remove(&it); 850 btstack_memory_l2cap_channel_free(channel); 851 break; 852 case L2CAP_STATE_OPEN: 853 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 854 855 // send credits 856 if (channel->new_credits_incoming){ 857 log_info("l2cap: sending %u credits", channel->new_credits_incoming); 858 channel->local_sig_id = l2cap_next_sig_id(); 859 uint16_t new_credits = channel->new_credits_incoming; 860 channel->new_credits_incoming = 0; 861 channel->credits_incoming += new_credits; 862 l2cap_send_le_signaling_packet(channel->con_handle, LE_FLOW_CONTROL_CREDIT, channel->local_sig_id, channel->remote_cid, new_credits); 863 break; 864 } 865 866 // send data 867 if (!channel->send_sdu_buffer) break; 868 if (!channel->credits_outgoing) break; 869 870 // send part of SDU 871 hci_reserve_packet_buffer(); 872 acl_buffer = hci_get_outgoing_packet_buffer(); 873 l2cap_payload = acl_buffer + 8; 874 pos = 0; 875 if (!channel->send_sdu_pos){ 876 // store SDU len 877 channel->send_sdu_pos += 2; 878 little_endian_store_16(l2cap_payload, pos, channel->send_sdu_len); 879 pos += 2; 880 } 881 payload_size = btstack_min(channel->send_sdu_len + 2 - channel->send_sdu_pos, channel->remote_mps - pos); 882 log_info("len %u, pos %u => payload %u, credits %u", channel->send_sdu_len, channel->send_sdu_pos, payload_size, channel->credits_outgoing); 883 memcpy(&l2cap_payload[pos], &channel->send_sdu_buffer[channel->send_sdu_pos-2], payload_size); // -2 for virtual SDU len 884 pos += payload_size; 885 channel->send_sdu_pos += payload_size; 886 l2cap_setup_header(acl_buffer, channel->con_handle, 0, channel->remote_cid, pos); 887 // done 888 889 channel->credits_outgoing--; 890 891 if (channel->send_sdu_pos >= channel->send_sdu_len + 2){ 892 channel->send_sdu_buffer = NULL; 893 // send done event 894 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_PACKET_SENT); 895 // inform about can send now 896 l2cap_le_notify_channel_can_send(channel); 897 } 898 hci_send_acl_packet_buffer(8 + pos); 899 break; 900 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 901 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 902 channel->local_sig_id = l2cap_next_sig_id(); 903 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 904 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 905 break; 906 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 907 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 908 channel->state = L2CAP_STATE_INVALID; 909 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 910 l2cap_le_finialize_channel_close(channel); // -- remove from list 911 break; 912 default: 913 break; 914 } 915 } 916 #endif 917 918 #ifdef ENABLE_BLE 919 // send l2cap con paramter update if necessary 920 hci_connections_get_iterator(&it); 921 while(btstack_linked_list_iterator_has_next(&it)){ 922 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 923 if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; 924 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 925 switch (connection->le_con_parameter_update_state){ 926 case CON_PARAMETER_UPDATE_SEND_REQUEST: 927 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 928 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, connection->le_con_param_update_identifier, 929 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 930 break; 931 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 932 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 933 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 934 break; 935 case CON_PARAMETER_UPDATE_DENY: 936 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 937 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 938 break; 939 default: 940 break; 941 } 942 } 943 #endif 944 945 // log_info("l2cap_run: exit"); 946 } 947 948 #ifdef ENABLE_CLASSIC 949 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 950 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 951 log_info("l2cap_handle_connection_complete expected state"); 952 // success, start l2cap handshake 953 channel->con_handle = con_handle; 954 // check remote SSP feature first 955 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 956 } 957 } 958 959 static void l2cap_ready_to_connect(l2cap_channel_t * channel){ 960 961 962 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 963 // TODO: we assume outgoing connection 964 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 965 // get hci_connection 966 hci_connection_t * connection = hci_connection_for_handle(channel->con_handle); 967 if (connection->l2cap_state.information_state == L2CAP_INFORMATION_STATE_IDLE){ 968 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_W2_SEND_EXTENDED_FEATURE_REQUEST; 969 channel->state = L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES; 970 return; 971 } 972 } 973 #endif 974 975 // fine, go ahead 976 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 977 } 978 979 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 980 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 981 982 // we have been waiting for remote supported features, if both support SSP, 983 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)); 984 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 985 // request security level 2 986 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 987 gap_request_security_level(channel->con_handle, LEVEL_2); 988 return; 989 } 990 991 l2cap_ready_to_connect(channel); 992 } 993 #endif 994 995 #ifdef L2CAP_USES_CHANNELS 996 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 997 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 998 999 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 1000 if (!channel) { 1001 return NULL; 1002 } 1003 1004 // Init memory (make valgrind happy) 1005 memset(channel, 0, sizeof(l2cap_channel_t)); 1006 1007 // fill in 1008 channel->packet_handler = packet_handler; 1009 bd_addr_copy(channel->address, address); 1010 channel->address_type = address_type; 1011 channel->psm = psm; 1012 channel->local_mtu = local_mtu; 1013 channel->remote_mtu = L2CAP_MINIMAL_MTU; 1014 channel->required_security_level = security_level; 1015 1016 // 1017 channel->local_cid = l2cap_next_local_cid(); 1018 channel->con_handle = 0; 1019 1020 // set initial state 1021 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 1022 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 1023 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 1024 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 1025 return channel; 1026 } 1027 #endif 1028 1029 #ifdef ENABLE_CLASSIC 1030 1031 /** 1032 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 1033 * @param packet_handler 1034 * @param address 1035 * @param psm 1036 * @param mtu 1037 * @param local_cid 1038 */ 1039 1040 uint8_t l2cap_create_channel(btstack_packet_handler_t channel_packet_handler, bd_addr_t address, uint16_t psm, uint16_t mtu, uint16_t * out_local_cid){ 1041 // limit MTU to the size of our outtgoing HCI buffer 1042 uint16_t local_mtu = btstack_min(mtu, l2cap_max_mtu()); 1043 1044 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u -> local mtu %u", bd_addr_to_str(address), psm, mtu, local_mtu); 1045 1046 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 1047 if (!channel) { 1048 return BTSTACK_MEMORY_ALLOC_FAILED; 1049 } 1050 1051 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1052 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1053 #endif 1054 1055 // add to connections list 1056 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1057 1058 // store local_cid 1059 if (out_local_cid){ 1060 *out_local_cid = channel->local_cid; 1061 } 1062 1063 // check if hci connection is already usable 1064 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 1065 if (conn){ 1066 log_info("l2cap_create_channel, hci connection already exists"); 1067 l2cap_handle_connection_complete(conn->con_handle, channel); 1068 // check if remote supported fearures are already received 1069 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 1070 l2cap_handle_remote_supported_features_received(channel); 1071 } 1072 } 1073 1074 l2cap_run(); 1075 1076 return 0; 1077 } 1078 1079 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1080 uint8_t l2cap_create_ertm_channel(btstack_packet_handler_t channel_packet_handler, bd_addr_t address, uint16_t psm, uint16_t mtu, int ertm_mandatory, uint16_t * out_local_cid){ 1081 // limit MTU to the size of our outtgoing HCI buffer 1082 uint16_t local_mtu = btstack_min(mtu, l2cap_max_mtu()); 1083 1084 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u -> local mtu %u", bd_addr_to_str(address), psm, mtu, local_mtu); 1085 1086 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 1087 if (!channel) { 1088 return BTSTACK_MEMORY_ALLOC_FAILED; 1089 } 1090 1091 channel->mode = L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION; 1092 channel->ertm_mandatory = ertm_mandatory; 1093 1094 // add to connections list 1095 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1096 1097 // store local_cid 1098 if (out_local_cid){ 1099 *out_local_cid = channel->local_cid; 1100 } 1101 1102 // check if hci connection is already usable 1103 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 1104 if (conn){ 1105 log_info("l2cap_create_channel, hci connection already exists"); 1106 l2cap_handle_connection_complete(conn->con_handle, channel); 1107 // check if remote supported fearures are already received 1108 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 1109 l2cap_handle_remote_supported_features_received(channel); 1110 } 1111 } 1112 1113 l2cap_run(); 1114 1115 return 0; 1116 } 1117 #endif 1118 1119 void 1120 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 1121 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 1122 // find channel for local_cid 1123 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1124 if (channel) { 1125 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1126 } 1127 // process 1128 l2cap_run(); 1129 } 1130 1131 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 1132 btstack_linked_list_iterator_t it; 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 ( bd_addr_cmp( channel->address, address) != 0) continue; 1137 // channel for this address found 1138 switch (channel->state){ 1139 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 1140 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1141 // failure, forward error code 1142 l2cap_emit_channel_opened(channel, status); 1143 // discard channel 1144 l2cap_stop_rtx(channel); 1145 btstack_linked_list_iterator_remove(&it); 1146 btstack_memory_l2cap_channel_free(channel); 1147 break; 1148 default: 1149 break; 1150 } 1151 } 1152 } 1153 1154 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1155 btstack_linked_list_iterator_t it; 1156 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1157 while (btstack_linked_list_iterator_has_next(&it)){ 1158 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1159 if ( ! bd_addr_cmp( channel->address, address) ){ 1160 l2cap_handle_connection_complete(handle, channel); 1161 } 1162 } 1163 // process 1164 l2cap_run(); 1165 } 1166 #endif 1167 1168 static void l2cap_notify_channel_can_send(void){ 1169 1170 #ifdef ENABLE_CLASSIC 1171 btstack_linked_list_iterator_t it; 1172 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1173 while (btstack_linked_list_iterator_has_next(&it)){ 1174 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1175 if (!channel->waiting_for_can_send_now) continue; 1176 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1177 channel->waiting_for_can_send_now = 0; 1178 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1179 } 1180 #endif 1181 1182 int i; 1183 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1184 if (!fixed_channels[i].callback) continue; 1185 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1186 int can_send = 0; 1187 if (l2cap_fixed_channel_table_index_is_le(i)){ 1188 #ifdef ENABLE_BLE 1189 can_send = hci_can_send_acl_le_packet_now(); 1190 #endif 1191 } else { 1192 #ifdef ENABLE_CLASSIC 1193 can_send = hci_can_send_acl_classic_packet_now(); 1194 #endif 1195 } 1196 if (!can_send) continue; 1197 fixed_channels[i].waiting_for_can_send_now = 0; 1198 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1199 } 1200 } 1201 1202 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1203 1204 UNUSED(packet_type); 1205 UNUSED(cid); 1206 UNUSED(size); 1207 1208 bd_addr_t address; 1209 hci_con_handle_t handle; 1210 int hci_con_used; 1211 btstack_linked_list_iterator_t it; 1212 1213 // avoid unused warnings 1214 UNUSED(address); 1215 UNUSED(hci_con_used); 1216 UNUSED(it); 1217 UNUSED(handle); 1218 1219 switch(hci_event_packet_get_type(packet)){ 1220 1221 // Notify channel packet handler if they can send now 1222 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1223 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1224 l2cap_run(); // try sending signaling packets first 1225 l2cap_notify_channel_can_send(); 1226 break; 1227 1228 case HCI_EVENT_COMMAND_STATUS: 1229 l2cap_run(); // try sending signaling packets first 1230 break; 1231 1232 #ifdef ENABLE_CLASSIC 1233 // handle connection complete events 1234 case HCI_EVENT_CONNECTION_COMPLETE: 1235 reverse_bd_addr(&packet[5], address); 1236 if (packet[2] == 0){ 1237 handle = little_endian_read_16(packet, 3); 1238 l2cap_handle_connection_success_for_addr(address, handle); 1239 } else { 1240 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1241 } 1242 break; 1243 1244 // handle successful create connection cancel command 1245 case HCI_EVENT_COMMAND_COMPLETE: 1246 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1247 if (packet[5] == 0){ 1248 reverse_bd_addr(&packet[6], address); 1249 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1250 l2cap_handle_connection_failed_for_addr(address, 0x16); 1251 } 1252 } 1253 l2cap_run(); // try sending signaling packets first 1254 break; 1255 #endif 1256 1257 // handle disconnection complete events 1258 case HCI_EVENT_DISCONNECTION_COMPLETE: 1259 // send l2cap disconnect events for all channels on this handle and free them 1260 #ifdef ENABLE_CLASSIC 1261 handle = little_endian_read_16(packet, 3); 1262 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1263 while (btstack_linked_list_iterator_has_next(&it)){ 1264 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1265 if (channel->con_handle != handle) continue; 1266 l2cap_emit_channel_closed(channel); 1267 l2cap_stop_rtx(channel); 1268 btstack_linked_list_iterator_remove(&it); 1269 btstack_memory_l2cap_channel_free(channel); 1270 } 1271 #endif 1272 #ifdef ENABLE_LE_DATA_CHANNELS 1273 handle = little_endian_read_16(packet, 3); 1274 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1275 while (btstack_linked_list_iterator_has_next(&it)){ 1276 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1277 if (channel->con_handle != handle) continue; 1278 l2cap_emit_channel_closed(channel); 1279 btstack_linked_list_iterator_remove(&it); 1280 btstack_memory_l2cap_channel_free(channel); 1281 } 1282 #endif 1283 break; 1284 1285 // HCI Connection Timeouts 1286 #ifdef ENABLE_CLASSIC 1287 case L2CAP_EVENT_TIMEOUT_CHECK: 1288 handle = little_endian_read_16(packet, 2); 1289 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1290 if (hci_authentication_active_for_handle(handle)) break; 1291 hci_con_used = 0; 1292 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1293 while (btstack_linked_list_iterator_has_next(&it)){ 1294 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1295 if (channel->con_handle != handle) continue; 1296 hci_con_used = 1; 1297 break; 1298 } 1299 if (hci_con_used) break; 1300 if (!hci_can_send_command_packet_now()) break; 1301 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1302 break; 1303 1304 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1305 handle = little_endian_read_16(packet, 3); 1306 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1307 while (btstack_linked_list_iterator_has_next(&it)){ 1308 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1309 if (channel->con_handle != handle) continue; 1310 l2cap_handle_remote_supported_features_received(channel); 1311 break; 1312 } 1313 break; 1314 1315 case GAP_EVENT_SECURITY_LEVEL: 1316 handle = little_endian_read_16(packet, 2); 1317 log_info("l2cap - security level update"); 1318 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1319 while (btstack_linked_list_iterator_has_next(&it)){ 1320 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1321 if (channel->con_handle != handle) continue; 1322 1323 log_info("l2cap - state %u", channel->state); 1324 1325 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1326 gap_security_level_t required_level = channel->required_security_level; 1327 1328 switch (channel->state){ 1329 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1330 if (actual_level >= required_level){ 1331 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1332 l2cap_emit_incoming_connection(channel); 1333 } else { 1334 channel->reason = 0x0003; // security block 1335 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1336 } 1337 break; 1338 1339 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1340 if (actual_level >= required_level){ 1341 l2cap_ready_to_connect(channel); 1342 } else { 1343 // disconnnect, authentication not good enough 1344 hci_disconnect_security_block(handle); 1345 } 1346 break; 1347 1348 default: 1349 break; 1350 } 1351 } 1352 break; 1353 #endif 1354 1355 default: 1356 break; 1357 } 1358 1359 l2cap_run(); 1360 } 1361 1362 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t cid, uint16_t data){ 1363 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1364 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1365 signaling_responses[signaling_responses_pending].handle = handle; 1366 signaling_responses[signaling_responses_pending].code = code; 1367 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1368 signaling_responses[signaling_responses_pending].cid = cid; 1369 signaling_responses[signaling_responses_pending].data = data; 1370 signaling_responses_pending++; 1371 l2cap_run(); 1372 } 1373 } 1374 1375 #ifdef ENABLE_CLASSIC 1376 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1377 channel->remote_sig_id = identifier; 1378 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1379 l2cap_run(); 1380 } 1381 1382 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1383 1384 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1385 l2cap_service_t *service = l2cap_get_service(psm); 1386 if (!service) { 1387 // 0x0002 PSM not supported 1388 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 1389 return; 1390 } 1391 1392 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1393 if (!hci_connection) { 1394 // 1395 log_error("no hci_connection for handle %u", handle); 1396 return; 1397 } 1398 1399 // alloc structure 1400 // log_info("l2cap_handle_connection_request register channel"); 1401 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 1402 psm, service->mtu, service->required_security_level); 1403 if (!channel){ 1404 // 0x0004 No resources available 1405 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 1406 return; 1407 } 1408 1409 channel->con_handle = handle; 1410 channel->remote_cid = source_cid; 1411 channel->remote_sig_id = sig_id; 1412 1413 // limit local mtu to max acl packet length - l2cap header 1414 if (channel->local_mtu > l2cap_max_mtu()) { 1415 channel->local_mtu = l2cap_max_mtu(); 1416 } 1417 1418 // set initial state 1419 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1420 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND | L2CAP_CHANNEL_STATE_VAR_INCOMING); 1421 1422 // add to connections list 1423 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1424 1425 // assert security requirements 1426 gap_request_security_level(handle, channel->required_security_level); 1427 } 1428 1429 void l2cap_accept_connection(uint16_t local_cid){ 1430 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1431 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1432 if (!channel) { 1433 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1434 return; 1435 } 1436 1437 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1438 // configure L2CAP Basic mode 1439 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1440 #endif 1441 1442 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1443 1444 // process 1445 l2cap_run(); 1446 } 1447 1448 1449 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1450 void l2cap_accept_ertm_connection(uint16_t local_cid, int ertm_mandatory){ 1451 log_info("L2CAP_ACCEPT_ERTM_CONNECTION local_cid 0x%x", local_cid); 1452 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1453 if (!channel) { 1454 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1455 return; 1456 } 1457 1458 // configure L2CAP ERTM 1459 channel->mode = L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION; 1460 channel->ertm_mandatory = ertm_mandatory; 1461 1462 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1463 1464 // process 1465 l2cap_run(); 1466 } 1467 #endif 1468 1469 1470 void l2cap_decline_connection(uint16_t local_cid){ 1471 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 1472 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1473 if (!channel) { 1474 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1475 return; 1476 } 1477 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1478 channel->reason = 0x04; // no resources available 1479 l2cap_run(); 1480 } 1481 1482 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1483 1484 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1485 1486 uint16_t flags = little_endian_read_16(command, 6); 1487 if (flags & 1) { 1488 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1489 } 1490 1491 // accept the other's configuration options 1492 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1493 uint16_t pos = 8; 1494 while (pos < end_pos){ 1495 uint8_t option_hint = command[pos] >> 7; 1496 uint8_t option_type = command[pos] & 0x7f; 1497 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1498 pos++; 1499 uint8_t length = command[pos++]; 1500 // MTU { type(8): 1, len(8):2, MTU(16) } 1501 if (option_type == 1 && length == 2){ 1502 channel->remote_mtu = little_endian_read_16(command, pos); 1503 if (channel->remote_mtu > l2cap_max_mtu()){ 1504 log_info("Remote MTU %u larger than outgoing buffer, only using MTU = %u", channel->remote_mtu, l2cap_max_mtu()); 1505 channel->remote_mtu = l2cap_max_mtu(); 1506 } 1507 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1508 } 1509 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1510 if (option_type == 2 && length == 2){ 1511 channel->flush_timeout = little_endian_read_16(command, pos); 1512 } 1513 1514 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1515 // Retransmission and Flow Control Option 1516 if (option_type == 4 && length == 9){ 1517 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION && channel->ertm_mandatory){ 1518 // ertm mandatory, but remote doens't offer ERTM -> disconnect 1519 l2cap_channel_mode_t mode = (l2cap_channel_mode_t) command[pos]; 1520 if (mode != L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1521 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1522 } 1523 } else { 1524 // TODO store and evaluate configuration 1525 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1526 } 1527 } 1528 #endif 1529 // check for unknown options 1530 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1531 log_info("l2cap cid %u, unknown options", channel->local_cid); 1532 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1533 } 1534 pos += length; 1535 } 1536 } 1537 1538 static void l2cap_signaling_handle_configure_response(l2cap_channel_t *channel, uint8_t result, uint8_t *command){ 1539 log_info("l2cap_signaling_handle_configure_response"); 1540 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1541 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1542 uint16_t pos = 10; 1543 while (pos < end_pos){ 1544 uint8_t option_hint = command[pos] >> 7; 1545 uint8_t option_type = command[pos] & 0x7f; 1546 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1547 pos++; 1548 uint8_t length = command[pos++]; 1549 1550 // Retransmission and Flow Control Option 1551 if (option_type == 4 && length == 9){ 1552 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 1553 if (channel->ertm_mandatory){ 1554 // 1555 } else { 1556 // On 'Reject - Unacceptable Parameters', fall back to BASIC mode 1557 if (result == 1){ 1558 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1559 } 1560 } 1561 } 1562 } 1563 1564 // check for unknown options 1565 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1566 log_info("l2cap cid %u, unknown options", channel->local_cid); 1567 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1568 } 1569 1570 pos += length; 1571 } 1572 #endif 1573 } 1574 1575 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1576 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1577 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1578 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1579 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 1580 if (channel->state == L2CAP_STATE_OPEN) return 0; 1581 return 1; 1582 } 1583 1584 1585 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1586 1587 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1588 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1589 uint16_t result = 0; 1590 1591 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1592 1593 // handle DISCONNECT REQUESTS seperately 1594 if (code == DISCONNECTION_REQUEST){ 1595 switch (channel->state){ 1596 case L2CAP_STATE_CONFIG: 1597 case L2CAP_STATE_OPEN: 1598 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1599 case L2CAP_STATE_WAIT_DISCONNECT: 1600 l2cap_handle_disconnect_request(channel, identifier); 1601 break; 1602 1603 default: 1604 // ignore in other states 1605 break; 1606 } 1607 return; 1608 } 1609 1610 // @STATEMACHINE(l2cap) 1611 switch (channel->state) { 1612 1613 case L2CAP_STATE_WAIT_CONNECT_RSP: 1614 switch (code){ 1615 case CONNECTION_RESPONSE: 1616 l2cap_stop_rtx(channel); 1617 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1618 switch (result) { 1619 case 0: 1620 // successful connection 1621 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1622 channel->state = L2CAP_STATE_CONFIG; 1623 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1624 break; 1625 case 1: 1626 // connection pending. get some coffee, but start the ERTX 1627 l2cap_start_ertx(channel); 1628 break; 1629 default: 1630 // channel closed 1631 channel->state = L2CAP_STATE_CLOSED; 1632 // map l2cap connection response result to BTstack status enumeration 1633 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1634 1635 // drop link key if security block 1636 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1637 gap_drop_link_key_for_bd_addr(channel->address); 1638 } 1639 1640 // discard channel 1641 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1642 btstack_memory_l2cap_channel_free(channel); 1643 break; 1644 } 1645 break; 1646 1647 default: 1648 //@TODO: implement other signaling packets 1649 break; 1650 } 1651 break; 1652 1653 case L2CAP_STATE_CONFIG: 1654 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1655 switch (code) { 1656 case CONFIGURE_REQUEST: 1657 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1658 l2cap_signaling_handle_configure_request(channel, command); 1659 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1660 // only done if continuation not set 1661 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1662 } 1663 break; 1664 case CONFIGURE_RESPONSE: 1665 l2cap_stop_rtx(channel); 1666 l2cap_signaling_handle_configure_response(channel, result, command); 1667 switch (result){ 1668 case 0: // success 1669 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1670 break; 1671 case 4: // pending 1672 l2cap_start_ertx(channel); 1673 break; 1674 default: 1675 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1676 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION && channel->ertm_mandatory){ 1677 // remote does not offer ertm but it's required 1678 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1679 break; 1680 } 1681 #endif 1682 // retry on negative result 1683 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1684 break; 1685 } 1686 break; 1687 default: 1688 break; 1689 } 1690 if (l2cap_channel_ready_for_open(channel)){ 1691 // for open: 1692 channel->state = L2CAP_STATE_OPEN; 1693 l2cap_emit_channel_opened(channel, 0); 1694 } 1695 break; 1696 1697 case L2CAP_STATE_WAIT_DISCONNECT: 1698 switch (code) { 1699 case DISCONNECTION_RESPONSE: 1700 l2cap_finialize_channel_close(channel); 1701 break; 1702 default: 1703 //@TODO: implement other signaling packets 1704 break; 1705 } 1706 break; 1707 1708 case L2CAP_STATE_CLOSED: 1709 // @TODO handle incoming requests 1710 break; 1711 1712 case L2CAP_STATE_OPEN: 1713 //@TODO: implement other signaling packets, e.g. re-configure 1714 break; 1715 default: 1716 break; 1717 } 1718 // log_info("new state %u", channel->state); 1719 } 1720 1721 1722 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1723 1724 btstack_linked_list_iterator_t it; 1725 1726 // get code, signalind identifier and command len 1727 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1728 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1729 1730 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_RESPONSE 1731 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_RESPONSE){ 1732 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 1733 return; 1734 } 1735 1736 // general commands without an assigned channel 1737 switch(code) { 1738 1739 case CONNECTION_REQUEST: { 1740 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1741 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1742 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1743 return; 1744 } 1745 1746 case ECHO_REQUEST: 1747 l2cap_register_signaling_response(handle, code, sig_id, 0, 0); 1748 return; 1749 1750 case INFORMATION_REQUEST: { 1751 uint16_t infoType = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1752 l2cap_register_signaling_response(handle, code, sig_id, 0, infoType); 1753 return; 1754 } 1755 1756 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1757 case INFORMATION_RESPONSE: { 1758 hci_connection_t * connection = hci_connection_for_handle(handle); 1759 if (!connection) return; 1760 uint16_t info_type = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1761 uint16_t result = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1762 if (result != 0) return; 1763 if (info_type != 0x02) return; 1764 connection->l2cap_state.information_state = L2CAP_INFORMATION_STATE_DONE; 1765 connection->l2cap_state.extended_feature_mask = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1766 log_info("extended features mask 0x%02x", connection->l2cap_state.extended_feature_mask); 1767 // trigger connection request 1768 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1769 while (btstack_linked_list_iterator_has_next(&it)){ 1770 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1771 if (channel->con_handle != handle) continue; 1772 // bail if ERTM was requested but is not supported 1773 if ((channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION) && ((connection->l2cap_state.extended_feature_mask & 0x08) == 0)){ 1774 // channel closed 1775 channel->state = L2CAP_STATE_CLOSED; 1776 // map l2cap connection response result to BTstack status enumeration 1777 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_ERTM_NOT_SUPPORTD); 1778 // discard channel 1779 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1780 btstack_memory_l2cap_channel_free(channel); 1781 continue; 1782 } 1783 // start connecting 1784 if (channel->state == L2CAP_STATE_WAIT_OUTGOING_EXTENDED_FEATURES){ 1785 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1786 } 1787 } 1788 return; 1789 } 1790 #endif 1791 1792 default: 1793 break; 1794 } 1795 1796 1797 // Get potential destination CID 1798 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1799 1800 // Find channel for this sig_id and connection handle 1801 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1802 while (btstack_linked_list_iterator_has_next(&it)){ 1803 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1804 if (channel->con_handle != handle) continue; 1805 if (code & 1) { 1806 // match odd commands (responses) by previous signaling identifier 1807 if (channel->local_sig_id == sig_id) { 1808 l2cap_signaling_handler_channel(channel, command); 1809 break; 1810 } 1811 } else { 1812 // match even commands (requests) by local channel id 1813 if (channel->local_cid == dest_cid) { 1814 l2cap_signaling_handler_channel(channel, command); 1815 break; 1816 } 1817 } 1818 } 1819 } 1820 #endif 1821 1822 #ifdef ENABLE_BLE 1823 1824 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 1825 uint8_t event[6]; 1826 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 1827 event[1] = 4; 1828 little_endian_store_16(event, 2, con_handle); 1829 little_endian_store_16(event, 4, result); 1830 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1831 if (!l2cap_event_packet_handler) return; 1832 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 1833 } 1834 1835 // @returns valid 1836 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 1837 hci_connection_t * connection; 1838 uint16_t result; 1839 uint8_t event[10]; 1840 1841 #ifdef ENABLE_LE_DATA_CHANNELS 1842 btstack_linked_list_iterator_t it; 1843 l2cap_channel_t * channel; 1844 uint16_t local_cid; 1845 uint16_t le_psm; 1846 uint16_t new_credits; 1847 uint16_t credits_before; 1848 l2cap_service_t * service; 1849 uint16_t source_cid; 1850 #endif 1851 1852 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1853 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 1854 1855 switch (code){ 1856 1857 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 1858 result = little_endian_read_16(command, 4); 1859 l2cap_emit_connection_parameter_update_response(handle, result); 1860 break; 1861 1862 case CONNECTION_PARAMETER_UPDATE_REQUEST: 1863 connection = hci_connection_for_handle(handle); 1864 if (connection){ 1865 if (connection->role != HCI_ROLE_MASTER){ 1866 // reject command without notifying upper layer when not in master role 1867 return 0; 1868 } 1869 int update_parameter = 1; 1870 le_connection_parameter_range_t existing_range; 1871 gap_get_connection_parameter_range(&existing_range); 1872 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 1873 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 1874 uint16_t le_conn_latency = little_endian_read_16(command,12); 1875 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 1876 1877 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 1878 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 1879 1880 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 1881 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 1882 1883 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 1884 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 1885 1886 if (update_parameter){ 1887 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 1888 connection->le_conn_interval_min = le_conn_interval_min; 1889 connection->le_conn_interval_max = le_conn_interval_max; 1890 connection->le_conn_latency = le_conn_latency; 1891 connection->le_supervision_timeout = le_supervision_timeout; 1892 } else { 1893 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 1894 } 1895 connection->le_con_param_update_identifier = sig_id; 1896 } 1897 1898 if (!l2cap_event_packet_handler) break; 1899 1900 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 1901 event[1] = 8; 1902 memcpy(&event[2], &command[4], 8); 1903 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1904 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1905 break; 1906 1907 #ifdef ENABLE_LE_DATA_CHANNELS 1908 1909 case COMMAND_REJECT: 1910 // Find channel for this sig_id and connection handle 1911 channel = NULL; 1912 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1913 while (btstack_linked_list_iterator_has_next(&it)){ 1914 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1915 if (a_channel->con_handle != handle) continue; 1916 if (a_channel->local_sig_id != sig_id) continue; 1917 channel = a_channel; 1918 break; 1919 } 1920 if (!channel) break; 1921 1922 // if received while waiting for le connection response, assume legacy device 1923 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 1924 channel->state = L2CAP_STATE_CLOSED; 1925 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 1926 l2cap_emit_le_channel_opened(channel, 0x0002); 1927 1928 // discard channel 1929 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1930 btstack_memory_l2cap_channel_free(channel); 1931 break; 1932 } 1933 break; 1934 1935 case LE_CREDIT_BASED_CONNECTION_REQUEST: 1936 1937 // get hci connection, bail if not found (must not happen) 1938 connection = hci_connection_for_handle(handle); 1939 if (!connection) return 0; 1940 1941 // check if service registered 1942 le_psm = little_endian_read_16(command, 4); 1943 service = l2cap_le_get_service(le_psm); 1944 source_cid = little_endian_read_16(command, 6); 1945 1946 if (service){ 1947 if (source_cid < 0x40){ 1948 // 0x0009 Connection refused - Invalid Source CID 1949 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0009); 1950 return 1; 1951 } 1952 1953 // go through list of channels for this ACL connection and check if we get a match 1954 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1955 while (btstack_linked_list_iterator_has_next(&it)){ 1956 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1957 if (a_channel->con_handle != handle) continue; 1958 if (a_channel->remote_cid != source_cid) continue; 1959 // 0x000a Connection refused - Source CID already allocated 1960 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x000a); 1961 return 1; 1962 } 1963 1964 // security: check encryption 1965 if (service->required_security_level >= LEVEL_2){ 1966 if (sm_encryption_key_size(handle) == 0){ 1967 // 0x0008 Connection refused - insufficient encryption 1968 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0008); 1969 return 1; 1970 } 1971 // anything less than 16 byte key size is insufficient 1972 if (sm_encryption_key_size(handle) < 16){ 1973 // 0x0007 Connection refused – insufficient encryption key size 1974 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0007); 1975 return 1; 1976 } 1977 } 1978 1979 // security: check authencation 1980 if (service->required_security_level >= LEVEL_3){ 1981 if (!sm_authenticated(handle)){ 1982 // 0x0005 Connection refused – insufficient authentication 1983 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0005); 1984 return 1; 1985 } 1986 } 1987 1988 // security: check authorization 1989 if (service->required_security_level >= LEVEL_4){ 1990 if (sm_authorization_state(handle) != AUTHORIZATION_GRANTED){ 1991 // 0x0006 Connection refused – insufficient authorization 1992 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0006); 1993 return 1; 1994 } 1995 } 1996 1997 // allocate channel 1998 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 1999 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 2000 if (!channel){ 2001 // 0x0004 Connection refused – no resources available 2002 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 2003 return 1; 2004 } 2005 2006 channel->con_handle = handle; 2007 channel->remote_cid = source_cid; 2008 channel->remote_sig_id = sig_id; 2009 channel->remote_mtu = little_endian_read_16(command, 8); 2010 channel->remote_mps = little_endian_read_16(command, 10); 2011 channel->credits_outgoing = little_endian_read_16(command, 12); 2012 2013 // set initial state 2014 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 2015 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_INCOMING; 2016 2017 // add to connections list 2018 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2019 2020 // post connection request event 2021 l2cap_emit_le_incoming_connection(channel); 2022 2023 } else { 2024 // Connection refused – LE_PSM not supported 2025 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 2026 } 2027 break; 2028 2029 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 2030 // Find channel for this sig_id and connection handle 2031 channel = NULL; 2032 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2033 while (btstack_linked_list_iterator_has_next(&it)){ 2034 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2035 if (a_channel->con_handle != handle) continue; 2036 if (a_channel->local_sig_id != sig_id) continue; 2037 channel = a_channel; 2038 break; 2039 } 2040 if (!channel) break; 2041 2042 // cid + 0 2043 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 2044 if (result){ 2045 channel->state = L2CAP_STATE_CLOSED; 2046 // map l2cap connection response result to BTstack status enumeration 2047 l2cap_emit_le_channel_opened(channel, result); 2048 2049 // discard channel 2050 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2051 btstack_memory_l2cap_channel_free(channel); 2052 break; 2053 } 2054 2055 // success 2056 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2057 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2058 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 2059 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 2060 channel->state = L2CAP_STATE_OPEN; 2061 l2cap_emit_le_channel_opened(channel, result); 2062 break; 2063 2064 case LE_FLOW_CONTROL_CREDIT: 2065 // find channel 2066 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2067 channel = l2cap_le_get_channel_for_local_cid(local_cid); 2068 if (!channel) { 2069 log_error("l2cap: no channel for cid 0x%02x", local_cid); 2070 break; 2071 } 2072 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 2073 credits_before = channel->credits_outgoing; 2074 channel->credits_outgoing += new_credits; 2075 // check for credit overrun 2076 if (credits_before > channel->credits_outgoing){ 2077 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 2078 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2079 break; 2080 } 2081 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 2082 break; 2083 2084 case DISCONNECTION_REQUEST: 2085 // find channel 2086 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 2087 channel = l2cap_le_get_channel_for_local_cid(local_cid); 2088 if (!channel) { 2089 log_error("l2cap: no channel for cid 0x%02x", local_cid); 2090 break; 2091 } 2092 channel->remote_sig_id = sig_id; 2093 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 2094 break; 2095 2096 #endif 2097 2098 case DISCONNECTION_RESPONSE: 2099 break; 2100 2101 default: 2102 // command unknown -> reject command 2103 return 0; 2104 } 2105 return 1; 2106 } 2107 #endif 2108 2109 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 2110 UNUSED(packet_type); 2111 UNUSED(channel); 2112 2113 l2cap_channel_t * l2cap_channel; 2114 UNUSED(l2cap_channel); 2115 2116 // Get Channel ID 2117 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 2118 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 2119 2120 switch (channel_id) { 2121 2122 #ifdef ENABLE_CLASSIC 2123 case L2CAP_CID_SIGNALING: { 2124 uint16_t command_offset = 8; 2125 while (command_offset < size) { 2126 // handle signaling commands 2127 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 2128 2129 // increment command_offset 2130 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 2131 } 2132 break; 2133 } 2134 #endif 2135 2136 #ifdef ENABLE_BLE 2137 case L2CAP_CID_SIGNALING_LE: { 2138 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 2139 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 2140 if (!valid){ 2141 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 2142 } 2143 break; 2144 } 2145 #endif 2146 2147 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 2148 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 2149 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2150 } 2151 break; 2152 2153 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 2154 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 2155 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2156 } 2157 break; 2158 2159 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 2160 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 2161 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2162 } 2163 break; 2164 2165 default: 2166 #ifdef ENABLE_CLASSIC 2167 // Find channel for this channel_id and connection handle 2168 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 2169 if (l2cap_channel) { 2170 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 2171 } 2172 #endif 2173 #ifdef ENABLE_LE_DATA_CHANNELS 2174 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 2175 if (l2cap_channel) { 2176 // credit counting 2177 if (l2cap_channel->credits_incoming == 0){ 2178 log_error("LE Data Channel packet received but no incoming credits"); 2179 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2180 break; 2181 } 2182 l2cap_channel->credits_incoming--; 2183 2184 // automatic credits 2185 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 2186 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 2187 } 2188 2189 // first fragment 2190 uint16_t pos = 0; 2191 if (!l2cap_channel->receive_sdu_len){ 2192 l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 2193 l2cap_channel->receive_sdu_pos = 0; 2194 pos += 2; 2195 size -= 2; 2196 } 2197 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); 2198 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 2199 // done? 2200 log_info("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 2201 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 2202 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 2203 l2cap_channel->receive_sdu_len = 0; 2204 } 2205 } else { 2206 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 2207 } 2208 #endif 2209 break; 2210 } 2211 2212 l2cap_run(); 2213 } 2214 2215 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 2216 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 2217 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 2218 if (index < 0) return; 2219 fixed_channels[index].callback = the_packet_handler; 2220 } 2221 2222 #ifdef ENABLE_CLASSIC 2223 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 2224 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 2225 channel->state = L2CAP_STATE_CLOSED; 2226 l2cap_emit_channel_closed(channel); 2227 // discard channel 2228 l2cap_stop_rtx(channel); 2229 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2230 btstack_memory_l2cap_channel_free(channel); 2231 } 2232 2233 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 2234 btstack_linked_list_iterator_t it; 2235 btstack_linked_list_iterator_init(&it, services); 2236 while (btstack_linked_list_iterator_has_next(&it)){ 2237 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 2238 if ( service->psm == psm){ 2239 return service; 2240 }; 2241 } 2242 return NULL; 2243 } 2244 2245 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 2246 return l2cap_get_service_internal(&l2cap_services, psm); 2247 } 2248 2249 2250 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 2251 2252 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 2253 2254 // check for alread registered psm 2255 l2cap_service_t *service = l2cap_get_service(psm); 2256 if (service) { 2257 log_error("l2cap_register_service: PSM %u already registered", psm); 2258 return L2CAP_SERVICE_ALREADY_REGISTERED; 2259 } 2260 2261 // alloc structure 2262 service = btstack_memory_l2cap_service_get(); 2263 if (!service) { 2264 log_error("l2cap_register_service: no memory for l2cap_service_t"); 2265 return BTSTACK_MEMORY_ALLOC_FAILED; 2266 } 2267 2268 // fill in 2269 service->psm = psm; 2270 service->mtu = mtu; 2271 service->packet_handler = service_packet_handler; 2272 service->required_security_level = security_level; 2273 2274 // add to services list 2275 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 2276 2277 // enable page scan 2278 gap_connectable_control(1); 2279 2280 return 0; 2281 } 2282 2283 uint8_t l2cap_unregister_service(uint16_t psm){ 2284 2285 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 2286 2287 l2cap_service_t *service = l2cap_get_service(psm); 2288 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2289 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 2290 btstack_memory_l2cap_service_free(service); 2291 2292 // disable page scan when no services registered 2293 if (btstack_linked_list_empty(&l2cap_services)) { 2294 gap_connectable_control(0); 2295 } 2296 return 0; 2297 } 2298 #endif 2299 2300 2301 #ifdef ENABLE_LE_DATA_CHANNELS 2302 2303 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel){ 2304 if (!channel->waiting_for_can_send_now) return; 2305 if (channel->send_sdu_buffer) return; 2306 channel->waiting_for_can_send_now = 0; 2307 log_info("L2CAP_EVENT_CHANNEL_LE_CAN_SEND_NOW local_cid 0x%x", channel->local_cid); 2308 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_CAN_SEND_NOW); 2309 } 2310 2311 // 1BH2222 2312 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel) { 2313 log_info("L2CAP_EVENT_LE_INCOMING_CONNECTION addr_type %u, addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x, remote_mtu %u", 2314 channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->remote_mtu); 2315 uint8_t event[19]; 2316 event[0] = L2CAP_EVENT_LE_INCOMING_CONNECTION; 2317 event[1] = sizeof(event) - 2; 2318 event[2] = channel->address_type; 2319 reverse_bd_addr(channel->address, &event[3]); 2320 little_endian_store_16(event, 9, channel->con_handle); 2321 little_endian_store_16(event, 11, channel->psm); 2322 little_endian_store_16(event, 13, channel->local_cid); 2323 little_endian_store_16(event, 15, channel->remote_cid); 2324 little_endian_store_16(event, 17, channel->remote_mtu); 2325 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2326 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2327 } 2328 // 11BH22222 2329 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status) { 2330 log_info("L2CAP_EVENT_LE_CHANNEL_OPENED status 0x%x addr_type %u addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x local_mtu %u, remote_mtu %u", 2331 status, channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 2332 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu); 2333 uint8_t event[23]; 2334 event[0] = L2CAP_EVENT_LE_CHANNEL_OPENED; 2335 event[1] = sizeof(event) - 2; 2336 event[2] = status; 2337 event[3] = channel->address_type; 2338 reverse_bd_addr(channel->address, &event[4]); 2339 little_endian_store_16(event, 10, channel->con_handle); 2340 event[12] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 2341 little_endian_store_16(event, 13, channel->psm); 2342 little_endian_store_16(event, 15, channel->local_cid); 2343 little_endian_store_16(event, 17, channel->remote_cid); 2344 little_endian_store_16(event, 19, channel->local_mtu); 2345 little_endian_store_16(event, 21, channel->remote_mtu); 2346 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2347 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2348 } 2349 2350 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 2351 btstack_linked_list_iterator_t it; 2352 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2353 while (btstack_linked_list_iterator_has_next(&it)){ 2354 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2355 if ( channel->local_cid == local_cid) { 2356 return channel; 2357 } 2358 } 2359 return NULL; 2360 } 2361 2362 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 2363 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 2364 channel->state = L2CAP_STATE_CLOSED; 2365 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 2366 // discard channel 2367 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2368 btstack_memory_l2cap_channel_free(channel); 2369 } 2370 2371 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 2372 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 2373 } 2374 2375 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 2376 2377 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 2378 2379 // check for alread registered psm 2380 l2cap_service_t *service = l2cap_le_get_service(psm); 2381 if (service) { 2382 return L2CAP_SERVICE_ALREADY_REGISTERED; 2383 } 2384 2385 // alloc structure 2386 service = btstack_memory_l2cap_service_get(); 2387 if (!service) { 2388 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 2389 return BTSTACK_MEMORY_ALLOC_FAILED; 2390 } 2391 2392 // fill in 2393 service->psm = psm; 2394 service->mtu = 0; 2395 service->packet_handler = packet_handler; 2396 service->required_security_level = security_level; 2397 2398 // add to services list 2399 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 2400 2401 // done 2402 return 0; 2403 } 2404 2405 uint8_t l2cap_le_unregister_service(uint16_t psm) { 2406 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 2407 l2cap_service_t *service = l2cap_le_get_service(psm); 2408 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2409 2410 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 2411 btstack_memory_l2cap_service_free(service); 2412 return 0; 2413 } 2414 2415 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 2416 // get channel 2417 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2418 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2419 2420 // validate state 2421 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2422 return ERROR_CODE_COMMAND_DISALLOWED; 2423 } 2424 2425 // set state accept connection 2426 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 2427 channel->receive_sdu_buffer = receive_sdu_buffer; 2428 channel->local_mtu = mtu; 2429 channel->new_credits_incoming = initial_credits; 2430 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2431 2432 // test 2433 // channel->new_credits_incoming = 1; 2434 2435 // go 2436 l2cap_run(); 2437 return 0; 2438 } 2439 2440 /** 2441 * @brief Deny incoming LE Data Channel connection due to resource constraints 2442 * @param local_cid L2CAP LE Data Channel Identifier 2443 */ 2444 2445 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 2446 // get channel 2447 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2448 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2449 2450 // validate state 2451 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2452 return ERROR_CODE_COMMAND_DISALLOWED; 2453 } 2454 2455 // set state decline connection 2456 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 2457 channel->reason = 0x04; // no resources available 2458 l2cap_run(); 2459 return 0; 2460 } 2461 2462 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 2463 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 2464 uint16_t * out_local_cid) { 2465 2466 log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 2467 2468 2469 hci_connection_t * connection = hci_connection_for_handle(con_handle); 2470 if (!connection) { 2471 log_error("no hci_connection for handle 0x%04x", con_handle); 2472 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 2473 } 2474 2475 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, connection->address, connection->address_type, psm, mtu, security_level); 2476 if (!channel) { 2477 return BTSTACK_MEMORY_ALLOC_FAILED; 2478 } 2479 log_info("l2cap_le_create_channel %p", channel); 2480 2481 // store local_cid 2482 if (out_local_cid){ 2483 *out_local_cid = channel->local_cid; 2484 } 2485 2486 // provide buffer 2487 channel->con_handle = con_handle; 2488 channel->receive_sdu_buffer = receive_sdu_buffer; 2489 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 2490 channel->new_credits_incoming = initial_credits; 2491 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2492 2493 // add to connections list 2494 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2495 2496 // go 2497 l2cap_run(); 2498 return 0; 2499 } 2500 2501 /** 2502 * @brief Provide credtis for LE Data Channel 2503 * @param local_cid L2CAP LE Data Channel Identifier 2504 * @param credits Number additional credits for peer 2505 */ 2506 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 2507 2508 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2509 if (!channel) { 2510 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2511 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2512 } 2513 2514 // check state 2515 if (channel->state != L2CAP_STATE_OPEN){ 2516 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 2517 } 2518 2519 // assert incoming credits + credits <= 0xffff 2520 uint32_t total_credits = channel->credits_incoming; 2521 total_credits += channel->new_credits_incoming; 2522 total_credits += credits; 2523 if (total_credits > 0xffff){ 2524 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 2525 channel->new_credits_incoming, credits); 2526 } 2527 2528 // set credits_granted 2529 channel->new_credits_incoming += credits; 2530 2531 // go 2532 l2cap_run(); 2533 return 0; 2534 } 2535 2536 /** 2537 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 2538 * @param local_cid L2CAP LE Data Channel Identifier 2539 */ 2540 int l2cap_le_can_send_now(uint16_t local_cid){ 2541 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2542 if (!channel) { 2543 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2544 return 0; 2545 } 2546 2547 // check state 2548 if (channel->state != L2CAP_STATE_OPEN) return 0; 2549 2550 // check queue 2551 if (channel->send_sdu_buffer) return 0; 2552 2553 // fine, go ahead 2554 return 1; 2555 } 2556 2557 /** 2558 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 2559 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 2560 * so packet handler should be ready to handle it 2561 * @param local_cid L2CAP LE Data Channel Identifier 2562 */ 2563 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 2564 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2565 if (!channel) { 2566 log_error("l2cap_le_request_can_send_now_event no channel for cid 0x%02x", local_cid); 2567 return 0; 2568 } 2569 channel->waiting_for_can_send_now = 1; 2570 l2cap_le_notify_channel_can_send(channel); 2571 return 0; 2572 } 2573 2574 /** 2575 * @brief Send data via LE Data Channel 2576 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 2577 * @param local_cid L2CAP LE Data Channel Identifier 2578 * @param data data to send 2579 * @param size data size 2580 */ 2581 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 2582 2583 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2584 if (!channel) { 2585 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2586 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2587 } 2588 2589 if (len > channel->remote_mtu){ 2590 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 2591 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 2592 } 2593 2594 if (channel->send_sdu_buffer){ 2595 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 2596 return BTSTACK_ACL_BUFFERS_FULL; 2597 } 2598 2599 channel->send_sdu_buffer = data; 2600 channel->send_sdu_len = len; 2601 channel->send_sdu_pos = 0; 2602 2603 l2cap_run(); 2604 return 0; 2605 } 2606 2607 /** 2608 * @brief Disconnect from LE Data Channel 2609 * @param local_cid L2CAP LE Data Channel Identifier 2610 */ 2611 uint8_t l2cap_le_disconnect(uint16_t local_cid) 2612 { 2613 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2614 if (!channel) { 2615 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2616 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2617 } 2618 2619 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2620 l2cap_run(); 2621 return 0; 2622 } 2623 2624 #endif 2625