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 // MARK: L2CAP_RUN 567 // process outstanding signaling tasks 568 static void l2cap_run(void){ 569 570 // log_info("l2cap_run: entered"); 571 572 // check pending signaling responses 573 while (signaling_responses_pending){ 574 575 hci_con_handle_t handle = signaling_responses[0].handle; 576 577 if (!hci_can_send_acl_packet_now(handle)) break; 578 579 uint8_t sig_id = signaling_responses[0].sig_id; 580 uint8_t response_code = signaling_responses[0].code; 581 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 582 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 583 #ifdef ENABLE_CLASSIC 584 uint16_t source_cid = signaling_responses[0].cid; // CONNECTION_REQUEST 585 #endif 586 UNUSED(infoType); 587 588 // remove first item before sending (to avoid sending response mutliple times) 589 signaling_responses_pending--; 590 int i; 591 for (i=0; i < signaling_responses_pending; i++){ 592 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 593 } 594 595 switch (response_code){ 596 #ifdef ENABLE_CLASSIC 597 case CONNECTION_REQUEST: 598 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, source_cid, 0, result, 0); 599 // also disconnect if result is 0x0003 - security blocked 600 if (result == 0x0003){ 601 hci_disconnect_security_block(handle); 602 } 603 break; 604 case ECHO_REQUEST: 605 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 606 break; 607 case INFORMATION_REQUEST: 608 switch (infoType){ 609 case 1: { // Connectionless MTU 610 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 611 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 612 } 613 break; 614 case 2: { // Extended Features Supported 615 // extended features request supported, features: fixed channels, unicast connectionless data reception 616 uint32_t features = 0x280; 617 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 618 } 619 break; 620 case 3: { // Fixed Channels Supported 621 uint8_t map[8]; 622 memset(map, 0, 8); 623 map[0] = 0x06; // L2CAP Signaling Channel (0x02) + Connectionless reception (0x04) 624 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 625 } 626 break; 627 default: 628 // all other types are not supported 629 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 630 break; 631 } 632 break; 633 case COMMAND_REJECT: 634 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 635 break; 636 #endif 637 #ifdef ENABLE_BLE 638 case LE_CREDIT_BASED_CONNECTION_REQUEST: 639 l2cap_send_le_signaling_packet(handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, sig_id, 0, 0, 0, 0, result); 640 break; 641 case COMMAND_REJECT_LE: 642 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 643 break; 644 #endif 645 default: 646 // should not happen 647 break; 648 } 649 } 650 651 btstack_linked_list_iterator_t it; 652 UNUSED(it); 653 654 #ifdef ENABLE_CLASSIC 655 uint8_t config_options[4]; 656 btstack_linked_list_iterator_init(&it, &l2cap_channels); 657 while (btstack_linked_list_iterator_has_next(&it)){ 658 659 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 660 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 661 switch (channel->state){ 662 663 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 664 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 665 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 666 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 667 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 668 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 669 } 670 break; 671 672 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 673 if (!hci_can_send_command_packet_now()) break; 674 // send connection request - set state first 675 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 676 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 677 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 678 break; 679 680 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 681 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 682 channel->state = L2CAP_STATE_INVALID; 683 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 684 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 685 l2cap_stop_rtx(channel); 686 btstack_linked_list_iterator_remove(&it); 687 btstack_memory_l2cap_channel_free(channel); 688 break; 689 690 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 691 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 692 channel->state = L2CAP_STATE_CONFIG; 693 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 694 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 695 break; 696 697 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 698 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 699 // success, start l2cap handshake 700 channel->local_sig_id = l2cap_next_sig_id(); 701 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 702 l2cap_send_signaling_packet( channel->con_handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 703 l2cap_start_rtx(channel); 704 break; 705 706 case L2CAP_STATE_CONFIG: 707 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 708 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 709 uint16_t flags = 0; 710 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 711 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 712 flags = 1; 713 } else { 714 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 715 } 716 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 717 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 718 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 719 config_options[0] = 1; // MTU 720 config_options[1] = 2; // len param 721 little_endian_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 722 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 723 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 724 } else { 725 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 726 } 727 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 728 } 729 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 730 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 731 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 732 channel->local_sig_id = l2cap_next_sig_id(); 733 config_options[0] = 1; // MTU 734 config_options[1] = 2; // len param 735 little_endian_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 736 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 737 l2cap_start_rtx(channel); 738 } 739 if (l2cap_channel_ready_for_open(channel)){ 740 channel->state = L2CAP_STATE_OPEN; 741 l2cap_emit_channel_opened(channel, 0); // success 742 } 743 break; 744 745 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 746 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 747 channel->state = L2CAP_STATE_INVALID; 748 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 749 // 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 :) 750 l2cap_finialize_channel_close(channel); // -- remove from list 751 break; 752 753 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 754 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 755 channel->local_sig_id = l2cap_next_sig_id(); 756 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 757 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 758 break; 759 default: 760 break; 761 } 762 } 763 #endif 764 765 #ifdef ENABLE_LE_DATA_CHANNELS 766 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 767 while (btstack_linked_list_iterator_has_next(&it)){ 768 uint8_t * acl_buffer; 769 uint8_t * l2cap_payload; 770 uint16_t pos; 771 uint16_t payload_size; 772 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 773 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 774 switch (channel->state){ 775 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 776 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 777 channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; 778 // le psm, source cid, mtu, mps, initial credits 779 channel->local_sig_id = l2cap_next_sig_id(); 780 channel->credits_incoming = channel->new_credits_incoming; 781 channel->new_credits_incoming = 0; 782 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); 783 break; 784 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 785 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 786 // TODO: support larger MPS 787 channel->state = L2CAP_STATE_OPEN; 788 channel->credits_incoming = channel->new_credits_incoming; 789 channel->new_credits_incoming = 0; 790 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); 791 // notify client 792 l2cap_emit_le_channel_opened(channel, 0); 793 break; 794 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 795 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 796 channel->state = L2CAP_STATE_INVALID; 797 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, 0, 0, channel->reason); 798 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 799 l2cap_stop_rtx(channel); 800 btstack_linked_list_iterator_remove(&it); 801 btstack_memory_l2cap_channel_free(channel); 802 break; 803 case L2CAP_STATE_OPEN: 804 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 805 806 // send credits 807 if (channel->new_credits_incoming){ 808 log_info("l2cap: sending %u credits", channel->new_credits_incoming); 809 channel->local_sig_id = l2cap_next_sig_id(); 810 uint16_t new_credits = channel->new_credits_incoming; 811 channel->new_credits_incoming = 0; 812 channel->credits_incoming += new_credits; 813 l2cap_send_le_signaling_packet(channel->con_handle, LE_FLOW_CONTROL_CREDIT, channel->local_sig_id, channel->remote_cid, new_credits); 814 break; 815 } 816 817 // send data 818 if (!channel->send_sdu_buffer) break; 819 if (!channel->credits_outgoing) break; 820 821 // send part of SDU 822 hci_reserve_packet_buffer(); 823 acl_buffer = hci_get_outgoing_packet_buffer(); 824 l2cap_payload = acl_buffer + 8; 825 pos = 0; 826 if (!channel->send_sdu_pos){ 827 // store SDU len 828 channel->send_sdu_pos += 2; 829 little_endian_store_16(l2cap_payload, pos, channel->send_sdu_len); 830 pos += 2; 831 } 832 payload_size = btstack_min(channel->send_sdu_len + 2 - channel->send_sdu_pos, channel->remote_mps - pos); 833 log_info("len %u, pos %u => payload %u, credits %u", channel->send_sdu_len, channel->send_sdu_pos, payload_size, channel->credits_outgoing); 834 memcpy(&l2cap_payload[pos], &channel->send_sdu_buffer[channel->send_sdu_pos-2], payload_size); // -2 for virtual SDU len 835 pos += payload_size; 836 channel->send_sdu_pos += payload_size; 837 l2cap_setup_header(acl_buffer, channel->con_handle, 0, channel->remote_cid, pos); 838 // done 839 840 channel->credits_outgoing--; 841 842 if (channel->send_sdu_pos >= channel->send_sdu_len + 2){ 843 channel->send_sdu_buffer = NULL; 844 // send done event 845 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_PACKET_SENT); 846 // inform about can send now 847 l2cap_le_notify_channel_can_send(channel); 848 } 849 hci_send_acl_packet_buffer(8 + pos); 850 break; 851 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 852 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 853 channel->local_sig_id = l2cap_next_sig_id(); 854 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 855 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 856 break; 857 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 858 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 859 channel->state = L2CAP_STATE_INVALID; 860 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 861 l2cap_le_finialize_channel_close(channel); // -- remove from list 862 break; 863 default: 864 break; 865 } 866 } 867 #endif 868 869 #ifdef ENABLE_BLE 870 // send l2cap con paramter update if necessary 871 hci_connections_get_iterator(&it); 872 while(btstack_linked_list_iterator_has_next(&it)){ 873 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 874 if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; 875 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 876 switch (connection->le_con_parameter_update_state){ 877 case CON_PARAMETER_UPDATE_SEND_REQUEST: 878 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 879 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, connection->le_con_param_update_identifier, 880 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 881 break; 882 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 883 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 884 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 885 break; 886 case CON_PARAMETER_UPDATE_DENY: 887 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 888 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 889 break; 890 default: 891 break; 892 } 893 } 894 #endif 895 896 // log_info("l2cap_run: exit"); 897 } 898 899 #ifdef ENABLE_CLASSIC 900 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 901 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 902 log_info("l2cap_handle_connection_complete expected state"); 903 // success, start l2cap handshake 904 channel->con_handle = con_handle; 905 // check remote SSP feature first 906 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 907 } 908 } 909 910 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 911 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 912 913 // we have been waiting for remote supported features, if both support SSP, 914 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)); 915 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 916 // request security level 2 917 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 918 gap_request_security_level(channel->con_handle, LEVEL_2); 919 return; 920 } 921 // fine, go ahead 922 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 923 } 924 #endif 925 926 #ifdef L2CAP_USES_CHANNELS 927 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 928 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 929 930 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 931 if (!channel) { 932 return NULL; 933 } 934 935 // Init memory (make valgrind happy) 936 memset(channel, 0, sizeof(l2cap_channel_t)); 937 938 // fill in 939 channel->packet_handler = packet_handler; 940 bd_addr_copy(channel->address, address); 941 channel->address_type = address_type; 942 channel->psm = psm; 943 channel->local_mtu = local_mtu; 944 channel->remote_mtu = L2CAP_MINIMAL_MTU; 945 channel->required_security_level = security_level; 946 947 // 948 channel->local_cid = l2cap_next_local_cid(); 949 channel->con_handle = 0; 950 951 // set initial state 952 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 953 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 954 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 955 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 956 return channel; 957 } 958 #endif 959 960 #ifdef ENABLE_CLASSIC 961 962 /** 963 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 964 * @param packet_handler 965 * @param address 966 * @param psm 967 * @param mtu 968 * @param local_cid 969 */ 970 971 uint8_t l2cap_create_channel(btstack_packet_handler_t channel_packet_handler, bd_addr_t address, uint16_t psm, uint16_t local_mtu, uint16_t * out_local_cid){ 972 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, local_mtu); 973 974 if (local_mtu > l2cap_max_mtu()) { 975 local_mtu = l2cap_max_mtu(); 976 } 977 978 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 979 if (!channel) { 980 return BTSTACK_MEMORY_ALLOC_FAILED; 981 } 982 983 // add to connections list 984 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 985 986 // store local_cid 987 if (out_local_cid){ 988 *out_local_cid = channel->local_cid; 989 } 990 991 // check if hci connection is already usable 992 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 993 if (conn){ 994 log_info("l2cap_create_channel, hci connection already exists"); 995 l2cap_handle_connection_complete(conn->con_handle, channel); 996 // check if remote supported fearures are already received 997 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 998 l2cap_handle_remote_supported_features_received(channel); 999 } 1000 } 1001 1002 l2cap_run(); 1003 1004 return 0; 1005 } 1006 1007 void 1008 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 1009 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 1010 // find channel for local_cid 1011 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1012 if (channel) { 1013 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1014 } 1015 // process 1016 l2cap_run(); 1017 } 1018 1019 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 1020 btstack_linked_list_iterator_t it; 1021 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1022 while (btstack_linked_list_iterator_has_next(&it)){ 1023 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1024 if ( bd_addr_cmp( channel->address, address) != 0) continue; 1025 // channel for this address found 1026 switch (channel->state){ 1027 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 1028 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1029 // failure, forward error code 1030 l2cap_emit_channel_opened(channel, status); 1031 // discard channel 1032 l2cap_stop_rtx(channel); 1033 btstack_linked_list_iterator_remove(&it); 1034 btstack_memory_l2cap_channel_free(channel); 1035 break; 1036 default: 1037 break; 1038 } 1039 } 1040 } 1041 1042 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1043 btstack_linked_list_iterator_t it; 1044 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1045 while (btstack_linked_list_iterator_has_next(&it)){ 1046 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1047 if ( ! bd_addr_cmp( channel->address, address) ){ 1048 l2cap_handle_connection_complete(handle, channel); 1049 } 1050 } 1051 // process 1052 l2cap_run(); 1053 } 1054 #endif 1055 1056 static void l2cap_notify_channel_can_send(void){ 1057 1058 #ifdef ENABLE_CLASSIC 1059 btstack_linked_list_iterator_t it; 1060 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1061 while (btstack_linked_list_iterator_has_next(&it)){ 1062 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1063 if (!channel->waiting_for_can_send_now) continue; 1064 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1065 channel->waiting_for_can_send_now = 0; 1066 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1067 } 1068 #endif 1069 1070 int i; 1071 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1072 if (!fixed_channels[i].callback) continue; 1073 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1074 int can_send = 0; 1075 if (l2cap_fixed_channel_table_index_is_le(i)){ 1076 #ifdef ENABLE_BLE 1077 can_send = hci_can_send_acl_le_packet_now(); 1078 #endif 1079 } else { 1080 #ifdef ENABLE_CLASSIC 1081 can_send = hci_can_send_acl_classic_packet_now(); 1082 #endif 1083 } 1084 if (!can_send) continue; 1085 fixed_channels[i].waiting_for_can_send_now = 0; 1086 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1087 } 1088 } 1089 1090 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1091 1092 UNUSED(packet_type); 1093 UNUSED(cid); 1094 UNUSED(size); 1095 1096 bd_addr_t address; 1097 hci_con_handle_t handle; 1098 int hci_con_used; 1099 btstack_linked_list_iterator_t it; 1100 1101 // avoid unused warnings 1102 UNUSED(address); 1103 UNUSED(hci_con_used); 1104 UNUSED(it); 1105 UNUSED(handle); 1106 1107 switch(hci_event_packet_get_type(packet)){ 1108 1109 // Notify channel packet handler if they can send now 1110 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1111 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1112 l2cap_run(); // try sending signaling packets first 1113 l2cap_notify_channel_can_send(); 1114 break; 1115 1116 case HCI_EVENT_COMMAND_STATUS: 1117 l2cap_run(); // try sending signaling packets first 1118 break; 1119 1120 #ifdef ENABLE_CLASSIC 1121 // handle connection complete events 1122 case HCI_EVENT_CONNECTION_COMPLETE: 1123 reverse_bd_addr(&packet[5], address); 1124 if (packet[2] == 0){ 1125 handle = little_endian_read_16(packet, 3); 1126 l2cap_handle_connection_success_for_addr(address, handle); 1127 } else { 1128 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1129 } 1130 break; 1131 1132 // handle successful create connection cancel command 1133 case HCI_EVENT_COMMAND_COMPLETE: 1134 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1135 if (packet[5] == 0){ 1136 reverse_bd_addr(&packet[6], address); 1137 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1138 l2cap_handle_connection_failed_for_addr(address, 0x16); 1139 } 1140 } 1141 l2cap_run(); // try sending signaling packets first 1142 break; 1143 #endif 1144 1145 // handle disconnection complete events 1146 case HCI_EVENT_DISCONNECTION_COMPLETE: 1147 // send l2cap disconnect events for all channels on this handle and free them 1148 #ifdef ENABLE_CLASSIC 1149 handle = little_endian_read_16(packet, 3); 1150 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1151 while (btstack_linked_list_iterator_has_next(&it)){ 1152 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1153 if (channel->con_handle != handle) continue; 1154 l2cap_emit_channel_closed(channel); 1155 l2cap_stop_rtx(channel); 1156 btstack_linked_list_iterator_remove(&it); 1157 btstack_memory_l2cap_channel_free(channel); 1158 } 1159 #endif 1160 #ifdef ENABLE_LE_DATA_CHANNELS 1161 handle = little_endian_read_16(packet, 3); 1162 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1163 while (btstack_linked_list_iterator_has_next(&it)){ 1164 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1165 if (channel->con_handle != handle) continue; 1166 l2cap_emit_channel_closed(channel); 1167 btstack_linked_list_iterator_remove(&it); 1168 btstack_memory_l2cap_channel_free(channel); 1169 } 1170 #endif 1171 break; 1172 1173 // HCI Connection Timeouts 1174 #ifdef ENABLE_CLASSIC 1175 case L2CAP_EVENT_TIMEOUT_CHECK: 1176 handle = little_endian_read_16(packet, 2); 1177 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1178 if (hci_authentication_active_for_handle(handle)) break; 1179 hci_con_used = 0; 1180 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1181 while (btstack_linked_list_iterator_has_next(&it)){ 1182 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1183 if (channel->con_handle != handle) continue; 1184 hci_con_used = 1; 1185 break; 1186 } 1187 if (hci_con_used) break; 1188 if (!hci_can_send_command_packet_now()) break; 1189 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1190 break; 1191 1192 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1193 handle = little_endian_read_16(packet, 3); 1194 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1195 while (btstack_linked_list_iterator_has_next(&it)){ 1196 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1197 if (channel->con_handle != handle) continue; 1198 l2cap_handle_remote_supported_features_received(channel); 1199 break; 1200 } 1201 break; 1202 1203 case GAP_EVENT_SECURITY_LEVEL: 1204 handle = little_endian_read_16(packet, 2); 1205 log_info("l2cap - security level update"); 1206 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1207 while (btstack_linked_list_iterator_has_next(&it)){ 1208 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1209 if (channel->con_handle != handle) continue; 1210 1211 log_info("l2cap - state %u", channel->state); 1212 1213 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1214 gap_security_level_t required_level = channel->required_security_level; 1215 1216 switch (channel->state){ 1217 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1218 if (actual_level >= required_level){ 1219 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1220 l2cap_emit_incoming_connection(channel); 1221 } else { 1222 channel->reason = 0x0003; // security block 1223 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1224 } 1225 break; 1226 1227 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1228 if (actual_level >= required_level){ 1229 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1230 } else { 1231 // disconnnect, authentication not good enough 1232 hci_disconnect_security_block(handle); 1233 } 1234 break; 1235 1236 default: 1237 break; 1238 } 1239 } 1240 break; 1241 #endif 1242 1243 default: 1244 break; 1245 } 1246 1247 l2cap_run(); 1248 } 1249 1250 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t cid, uint16_t data){ 1251 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1252 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1253 signaling_responses[signaling_responses_pending].handle = handle; 1254 signaling_responses[signaling_responses_pending].code = code; 1255 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1256 signaling_responses[signaling_responses_pending].cid = cid; 1257 signaling_responses[signaling_responses_pending].data = data; 1258 signaling_responses_pending++; 1259 l2cap_run(); 1260 } 1261 } 1262 1263 #ifdef ENABLE_CLASSIC 1264 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1265 channel->remote_sig_id = identifier; 1266 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1267 l2cap_run(); 1268 } 1269 1270 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1271 1272 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1273 l2cap_service_t *service = l2cap_get_service(psm); 1274 if (!service) { 1275 // 0x0002 PSM not supported 1276 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 1277 return; 1278 } 1279 1280 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1281 if (!hci_connection) { 1282 // 1283 log_error("no hci_connection for handle %u", handle); 1284 return; 1285 } 1286 1287 // alloc structure 1288 // log_info("l2cap_handle_connection_request register channel"); 1289 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 1290 psm, service->mtu, service->required_security_level); 1291 if (!channel){ 1292 // 0x0004 No resources available 1293 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 1294 return; 1295 } 1296 1297 channel->con_handle = handle; 1298 channel->remote_cid = source_cid; 1299 channel->remote_sig_id = sig_id; 1300 1301 // limit local mtu to max acl packet length - l2cap header 1302 if (channel->local_mtu > l2cap_max_mtu()) { 1303 channel->local_mtu = l2cap_max_mtu(); 1304 } 1305 1306 // set initial state 1307 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1308 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND | L2CAP_CHANNEL_STATE_VAR_INCOMING); 1309 1310 // add to connections list 1311 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1312 1313 // assert security requirements 1314 gap_request_security_level(handle, channel->required_security_level); 1315 } 1316 1317 void l2cap_accept_connection(uint16_t local_cid){ 1318 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1319 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1320 if (!channel) { 1321 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1322 return; 1323 } 1324 1325 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1326 1327 // process 1328 l2cap_run(); 1329 } 1330 1331 void l2cap_decline_connection(uint16_t local_cid){ 1332 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 1333 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1334 if (!channel) { 1335 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1336 return; 1337 } 1338 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1339 channel->reason = 0x04; // no resources available 1340 l2cap_run(); 1341 } 1342 1343 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1344 1345 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1346 1347 uint16_t flags = little_endian_read_16(command, 6); 1348 if (flags & 1) { 1349 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1350 } 1351 1352 // accept the other's configuration options 1353 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1354 uint16_t pos = 8; 1355 while (pos < end_pos){ 1356 uint8_t option_hint = command[pos] >> 7; 1357 uint8_t option_type = command[pos] & 0x7f; 1358 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1359 pos++; 1360 uint8_t length = command[pos++]; 1361 // MTU { type(8): 1, len(8):2, MTU(16) } 1362 if (option_type == 1 && length == 2){ 1363 channel->remote_mtu = little_endian_read_16(command, pos); 1364 // log_info("l2cap cid 0x%02x, remote mtu %u", channel->local_cid, channel->remote_mtu); 1365 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1366 } 1367 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1368 if (option_type == 2 && length == 2){ 1369 channel->flush_timeout = little_endian_read_16(command, pos); 1370 } 1371 // check for unknown options 1372 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1373 log_info("l2cap cid %u, unknown options", channel->local_cid); 1374 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1375 } 1376 pos += length; 1377 } 1378 } 1379 1380 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1381 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1382 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1383 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1384 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 1385 if (channel->state == L2CAP_STATE_OPEN) return 0; 1386 return 1; 1387 } 1388 1389 1390 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1391 1392 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1393 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1394 uint16_t result = 0; 1395 1396 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1397 1398 // handle DISCONNECT REQUESTS seperately 1399 if (code == DISCONNECTION_REQUEST){ 1400 switch (channel->state){ 1401 case L2CAP_STATE_CONFIG: 1402 case L2CAP_STATE_OPEN: 1403 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1404 case L2CAP_STATE_WAIT_DISCONNECT: 1405 l2cap_handle_disconnect_request(channel, identifier); 1406 break; 1407 1408 default: 1409 // ignore in other states 1410 break; 1411 } 1412 return; 1413 } 1414 1415 // @STATEMACHINE(l2cap) 1416 switch (channel->state) { 1417 1418 case L2CAP_STATE_WAIT_CONNECT_RSP: 1419 switch (code){ 1420 case CONNECTION_RESPONSE: 1421 l2cap_stop_rtx(channel); 1422 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1423 switch (result) { 1424 case 0: 1425 // successful connection 1426 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1427 channel->state = L2CAP_STATE_CONFIG; 1428 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1429 break; 1430 case 1: 1431 // connection pending. get some coffee, but start the ERTX 1432 l2cap_start_ertx(channel); 1433 break; 1434 default: 1435 // channel closed 1436 channel->state = L2CAP_STATE_CLOSED; 1437 // map l2cap connection response result to BTstack status enumeration 1438 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1439 1440 // drop link key if security block 1441 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1442 gap_drop_link_key_for_bd_addr(channel->address); 1443 } 1444 1445 // discard channel 1446 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1447 btstack_memory_l2cap_channel_free(channel); 1448 break; 1449 } 1450 break; 1451 1452 default: 1453 //@TODO: implement other signaling packets 1454 break; 1455 } 1456 break; 1457 1458 case L2CAP_STATE_CONFIG: 1459 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1460 switch (code) { 1461 case CONFIGURE_REQUEST: 1462 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1463 l2cap_signaling_handle_configure_request(channel, command); 1464 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1465 // only done if continuation not set 1466 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1467 } 1468 break; 1469 case CONFIGURE_RESPONSE: 1470 l2cap_stop_rtx(channel); 1471 switch (result){ 1472 case 0: // success 1473 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1474 break; 1475 case 4: // pending 1476 l2cap_start_ertx(channel); 1477 break; 1478 default: 1479 // retry on negative result 1480 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1481 break; 1482 } 1483 break; 1484 default: 1485 break; 1486 } 1487 if (l2cap_channel_ready_for_open(channel)){ 1488 // for open: 1489 channel->state = L2CAP_STATE_OPEN; 1490 l2cap_emit_channel_opened(channel, 0); 1491 } 1492 break; 1493 1494 case L2CAP_STATE_WAIT_DISCONNECT: 1495 switch (code) { 1496 case DISCONNECTION_RESPONSE: 1497 l2cap_finialize_channel_close(channel); 1498 break; 1499 default: 1500 //@TODO: implement other signaling packets 1501 break; 1502 } 1503 break; 1504 1505 case L2CAP_STATE_CLOSED: 1506 // @TODO handle incoming requests 1507 break; 1508 1509 case L2CAP_STATE_OPEN: 1510 //@TODO: implement other signaling packets, e.g. re-configure 1511 break; 1512 default: 1513 break; 1514 } 1515 // log_info("new state %u", channel->state); 1516 } 1517 1518 1519 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1520 1521 // get code, signalind identifier and command len 1522 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1523 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1524 1525 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1526 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1527 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 1528 return; 1529 } 1530 1531 // general commands without an assigned channel 1532 switch(code) { 1533 1534 case CONNECTION_REQUEST: { 1535 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1536 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1537 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1538 return; 1539 } 1540 1541 case ECHO_REQUEST: 1542 l2cap_register_signaling_response(handle, code, sig_id, 0, 0); 1543 return; 1544 1545 case INFORMATION_REQUEST: { 1546 uint16_t infoType = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1547 l2cap_register_signaling_response(handle, code, sig_id, 0, infoType); 1548 return; 1549 } 1550 1551 default: 1552 break; 1553 } 1554 1555 1556 // Get potential destination CID 1557 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1558 1559 // Find channel for this sig_id and connection handle 1560 btstack_linked_list_iterator_t it; 1561 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1562 while (btstack_linked_list_iterator_has_next(&it)){ 1563 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1564 if (channel->con_handle != handle) continue; 1565 if (code & 1) { 1566 // match odd commands (responses) by previous signaling identifier 1567 if (channel->local_sig_id == sig_id) { 1568 l2cap_signaling_handler_channel(channel, command); 1569 break; 1570 } 1571 } else { 1572 // match even commands (requests) by local channel id 1573 if (channel->local_cid == dest_cid) { 1574 l2cap_signaling_handler_channel(channel, command); 1575 break; 1576 } 1577 } 1578 } 1579 } 1580 #endif 1581 1582 #ifdef ENABLE_BLE 1583 1584 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 1585 uint8_t event[6]; 1586 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 1587 event[1] = 4; 1588 little_endian_store_16(event, 2, con_handle); 1589 little_endian_store_16(event, 4, result); 1590 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1591 if (!l2cap_event_packet_handler) return; 1592 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 1593 } 1594 1595 // @returns valid 1596 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 1597 hci_connection_t * connection; 1598 uint16_t result; 1599 uint8_t event[10]; 1600 1601 #ifdef ENABLE_LE_DATA_CHANNELS 1602 btstack_linked_list_iterator_t it; 1603 l2cap_channel_t * channel; 1604 uint16_t local_cid; 1605 uint16_t le_psm; 1606 uint16_t new_credits; 1607 uint16_t credits_before; 1608 l2cap_service_t * service; 1609 uint16_t source_cid; 1610 #endif 1611 1612 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1613 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 1614 1615 switch (code){ 1616 1617 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 1618 result = little_endian_read_16(command, 4); 1619 l2cap_emit_connection_parameter_update_response(handle, result); 1620 break; 1621 1622 case CONNECTION_PARAMETER_UPDATE_REQUEST: 1623 connection = hci_connection_for_handle(handle); 1624 if (connection){ 1625 if (connection->role != HCI_ROLE_MASTER){ 1626 // reject command without notifying upper layer when not in master role 1627 return 0; 1628 } 1629 int update_parameter = 1; 1630 le_connection_parameter_range_t existing_range; 1631 gap_get_connection_parameter_range(&existing_range); 1632 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 1633 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 1634 uint16_t le_conn_latency = little_endian_read_16(command,12); 1635 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 1636 1637 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 1638 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 1639 1640 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 1641 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 1642 1643 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 1644 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 1645 1646 if (update_parameter){ 1647 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 1648 connection->le_conn_interval_min = le_conn_interval_min; 1649 connection->le_conn_interval_max = le_conn_interval_max; 1650 connection->le_conn_latency = le_conn_latency; 1651 connection->le_supervision_timeout = le_supervision_timeout; 1652 } else { 1653 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 1654 } 1655 connection->le_con_param_update_identifier = sig_id; 1656 } 1657 1658 if (!l2cap_event_packet_handler) break; 1659 1660 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 1661 event[1] = 8; 1662 memcpy(&event[2], &command[4], 8); 1663 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1664 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1665 break; 1666 1667 #ifdef ENABLE_LE_DATA_CHANNELS 1668 1669 case COMMAND_REJECT: 1670 // Find channel for this sig_id and connection handle 1671 channel = NULL; 1672 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1673 while (btstack_linked_list_iterator_has_next(&it)){ 1674 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1675 if (a_channel->con_handle != handle) continue; 1676 if (a_channel->local_sig_id != sig_id) continue; 1677 channel = a_channel; 1678 break; 1679 } 1680 if (!channel) break; 1681 1682 // if received while waiting for le connection response, assume legacy device 1683 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 1684 channel->state = L2CAP_STATE_CLOSED; 1685 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 1686 l2cap_emit_le_channel_opened(channel, 0x0002); 1687 1688 // discard channel 1689 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1690 btstack_memory_l2cap_channel_free(channel); 1691 break; 1692 } 1693 break; 1694 1695 case LE_CREDIT_BASED_CONNECTION_REQUEST: 1696 1697 // get hci connection, bail if not found (must not happen) 1698 connection = hci_connection_for_handle(handle); 1699 if (!connection) return 0; 1700 1701 // check if service registered 1702 le_psm = little_endian_read_16(command, 4); 1703 service = l2cap_le_get_service(le_psm); 1704 source_cid = little_endian_read_16(command, 6); 1705 1706 if (service){ 1707 if (source_cid < 0x40){ 1708 // 0x0009 Connection refused - Invalid Source CID 1709 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0009); 1710 return 1; 1711 } 1712 1713 // go through list of channels for this ACL connection and check if we get a match 1714 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1715 while (btstack_linked_list_iterator_has_next(&it)){ 1716 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1717 if (a_channel->con_handle != handle) continue; 1718 if (a_channel->remote_cid != source_cid) continue; 1719 // 0x000a Connection refused - Source CID already allocated 1720 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x000a); 1721 return 1; 1722 } 1723 1724 // security: check encryption 1725 if (service->required_security_level >= LEVEL_2){ 1726 if (sm_encryption_key_size(handle) == 0){ 1727 // 0x0008 Connection refused - insufficient encryption 1728 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0008); 1729 return 1; 1730 } 1731 // anything less than 16 byte key size is insufficient 1732 if (sm_encryption_key_size(handle) < 16){ 1733 // 0x0007 Connection refused – insufficient encryption key size 1734 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0007); 1735 return 1; 1736 } 1737 } 1738 1739 // security: check authencation 1740 if (service->required_security_level >= LEVEL_3){ 1741 if (!sm_authenticated(handle)){ 1742 // 0x0005 Connection refused – insufficient authentication 1743 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0005); 1744 return 1; 1745 } 1746 } 1747 1748 // security: check authorization 1749 if (service->required_security_level >= LEVEL_4){ 1750 if (sm_authorization_state(handle) != AUTHORIZATION_GRANTED){ 1751 // 0x0006 Connection refused – insufficient authorization 1752 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0006); 1753 return 1; 1754 } 1755 } 1756 1757 // allocate channel 1758 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 1759 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 1760 if (!channel){ 1761 // 0x0004 Connection refused – no resources available 1762 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 1763 return 1; 1764 } 1765 1766 channel->con_handle = handle; 1767 channel->remote_cid = source_cid; 1768 channel->remote_sig_id = sig_id; 1769 channel->remote_mtu = little_endian_read_16(command, 8); 1770 channel->remote_mps = little_endian_read_16(command, 10); 1771 channel->credits_outgoing = little_endian_read_16(command, 12); 1772 1773 // set initial state 1774 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1775 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_INCOMING; 1776 1777 // add to connections list 1778 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1779 1780 // post connection request event 1781 l2cap_emit_le_incoming_connection(channel); 1782 1783 } else { 1784 // Connection refused – LE_PSM not supported 1785 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 1786 } 1787 break; 1788 1789 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 1790 // Find channel for this sig_id and connection handle 1791 channel = NULL; 1792 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1793 while (btstack_linked_list_iterator_has_next(&it)){ 1794 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1795 if (a_channel->con_handle != handle) continue; 1796 if (a_channel->local_sig_id != sig_id) continue; 1797 channel = a_channel; 1798 break; 1799 } 1800 if (!channel) break; 1801 1802 // cid + 0 1803 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 1804 if (result){ 1805 channel->state = L2CAP_STATE_CLOSED; 1806 // map l2cap connection response result to BTstack status enumeration 1807 l2cap_emit_le_channel_opened(channel, result); 1808 1809 // discard channel 1810 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1811 btstack_memory_l2cap_channel_free(channel); 1812 break; 1813 } 1814 1815 // success 1816 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1817 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1818 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 1819 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 1820 channel->state = L2CAP_STATE_OPEN; 1821 l2cap_emit_le_channel_opened(channel, result); 1822 break; 1823 1824 case LE_FLOW_CONTROL_CREDIT: 1825 // find channel 1826 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1827 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1828 if (!channel) { 1829 log_error("l2cap: no channel for cid 0x%02x", local_cid); 1830 break; 1831 } 1832 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1833 credits_before = channel->credits_outgoing; 1834 channel->credits_outgoing += new_credits; 1835 // check for credit overrun 1836 if (credits_before > channel->credits_outgoing){ 1837 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 1838 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1839 break; 1840 } 1841 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 1842 break; 1843 1844 case DISCONNECTION_REQUEST: 1845 // find channel 1846 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1847 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1848 if (!channel) { 1849 log_error("l2cap: no channel for cid 0x%02x", local_cid); 1850 break; 1851 } 1852 channel->remote_sig_id = sig_id; 1853 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1854 break; 1855 1856 #endif 1857 1858 case DISCONNECTION_RESPONSE: 1859 break; 1860 1861 default: 1862 // command unknown -> reject command 1863 return 0; 1864 } 1865 return 1; 1866 } 1867 #endif 1868 1869 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 1870 UNUSED(packet_type); 1871 UNUSED(channel); 1872 1873 l2cap_channel_t * l2cap_channel; 1874 UNUSED(l2cap_channel); 1875 1876 // Get Channel ID 1877 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1878 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1879 1880 switch (channel_id) { 1881 1882 #ifdef ENABLE_CLASSIC 1883 case L2CAP_CID_SIGNALING: { 1884 uint16_t command_offset = 8; 1885 while (command_offset < size) { 1886 // handle signaling commands 1887 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1888 1889 // increment command_offset 1890 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1891 } 1892 break; 1893 } 1894 #endif 1895 1896 #ifdef ENABLE_BLE 1897 case L2CAP_CID_SIGNALING_LE: { 1898 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1899 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 1900 if (!valid){ 1901 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 1902 } 1903 break; 1904 } 1905 #endif 1906 1907 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1908 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 1909 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1910 } 1911 break; 1912 1913 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1914 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 1915 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1916 } 1917 break; 1918 1919 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 1920 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 1921 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1922 } 1923 break; 1924 1925 default: 1926 #ifdef ENABLE_CLASSIC 1927 // Find channel for this channel_id and connection handle 1928 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 1929 if (l2cap_channel) { 1930 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1931 } 1932 #endif 1933 #ifdef ENABLE_LE_DATA_CHANNELS 1934 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 1935 if (l2cap_channel) { 1936 // credit counting 1937 if (l2cap_channel->credits_incoming == 0){ 1938 log_error("LE Data Channel packet received but no incoming credits"); 1939 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1940 break; 1941 } 1942 l2cap_channel->credits_incoming--; 1943 1944 // automatic credits 1945 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 1946 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 1947 } 1948 1949 // first fragment 1950 uint16_t pos = 0; 1951 if (!l2cap_channel->receive_sdu_len){ 1952 l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 1953 l2cap_channel->receive_sdu_pos = 0; 1954 pos += 2; 1955 size -= 2; 1956 } 1957 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); 1958 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 1959 // done? 1960 log_info("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 1961 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 1962 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 1963 l2cap_channel->receive_sdu_len = 0; 1964 } 1965 } else { 1966 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 1967 } 1968 #endif 1969 break; 1970 } 1971 1972 l2cap_run(); 1973 } 1974 1975 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1976 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 1977 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 1978 if (index < 0) return; 1979 fixed_channels[index].callback = the_packet_handler; 1980 } 1981 1982 #ifdef ENABLE_CLASSIC 1983 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1984 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 1985 channel->state = L2CAP_STATE_CLOSED; 1986 l2cap_emit_channel_closed(channel); 1987 // discard channel 1988 l2cap_stop_rtx(channel); 1989 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1990 btstack_memory_l2cap_channel_free(channel); 1991 } 1992 1993 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 1994 btstack_linked_list_iterator_t it; 1995 btstack_linked_list_iterator_init(&it, services); 1996 while (btstack_linked_list_iterator_has_next(&it)){ 1997 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 1998 if ( service->psm == psm){ 1999 return service; 2000 }; 2001 } 2002 return NULL; 2003 } 2004 2005 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 2006 return l2cap_get_service_internal(&l2cap_services, psm); 2007 } 2008 2009 2010 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 2011 2012 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 2013 2014 // check for alread registered psm 2015 l2cap_service_t *service = l2cap_get_service(psm); 2016 if (service) { 2017 log_error("l2cap_register_service: PSM %u already registered", psm); 2018 return L2CAP_SERVICE_ALREADY_REGISTERED; 2019 } 2020 2021 // alloc structure 2022 service = btstack_memory_l2cap_service_get(); 2023 if (!service) { 2024 log_error("l2cap_register_service: no memory for l2cap_service_t"); 2025 return BTSTACK_MEMORY_ALLOC_FAILED; 2026 } 2027 2028 // fill in 2029 service->psm = psm; 2030 service->mtu = mtu; 2031 service->packet_handler = service_packet_handler; 2032 service->required_security_level = security_level; 2033 2034 // add to services list 2035 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 2036 2037 // enable page scan 2038 gap_connectable_control(1); 2039 2040 return 0; 2041 } 2042 2043 uint8_t l2cap_unregister_service(uint16_t psm){ 2044 2045 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 2046 2047 l2cap_service_t *service = l2cap_get_service(psm); 2048 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2049 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 2050 btstack_memory_l2cap_service_free(service); 2051 2052 // disable page scan when no services registered 2053 if (btstack_linked_list_empty(&l2cap_services)) { 2054 gap_connectable_control(0); 2055 } 2056 return 0; 2057 } 2058 #endif 2059 2060 2061 #ifdef ENABLE_LE_DATA_CHANNELS 2062 2063 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel){ 2064 if (!channel->waiting_for_can_send_now) return; 2065 if (channel->send_sdu_buffer) return; 2066 channel->waiting_for_can_send_now = 0; 2067 log_info("L2CAP_EVENT_CHANNEL_LE_CAN_SEND_NOW local_cid 0x%x", channel->local_cid); 2068 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_CAN_SEND_NOW); 2069 } 2070 2071 // 1BH2222 2072 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel) { 2073 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", 2074 channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->remote_mtu); 2075 uint8_t event[19]; 2076 event[0] = L2CAP_EVENT_LE_INCOMING_CONNECTION; 2077 event[1] = sizeof(event) - 2; 2078 event[2] = channel->address_type; 2079 reverse_bd_addr(channel->address, &event[3]); 2080 little_endian_store_16(event, 9, channel->con_handle); 2081 little_endian_store_16(event, 11, channel->psm); 2082 little_endian_store_16(event, 13, channel->local_cid); 2083 little_endian_store_16(event, 15, channel->remote_cid); 2084 little_endian_store_16(event, 17, channel->remote_mtu); 2085 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2086 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2087 } 2088 // 11BH22222 2089 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status) { 2090 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", 2091 status, channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 2092 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu); 2093 uint8_t event[23]; 2094 event[0] = L2CAP_EVENT_LE_CHANNEL_OPENED; 2095 event[1] = sizeof(event) - 2; 2096 event[2] = status; 2097 event[3] = channel->address_type; 2098 reverse_bd_addr(channel->address, &event[4]); 2099 little_endian_store_16(event, 10, channel->con_handle); 2100 event[12] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 2101 little_endian_store_16(event, 13, channel->psm); 2102 little_endian_store_16(event, 15, channel->local_cid); 2103 little_endian_store_16(event, 17, channel->remote_cid); 2104 little_endian_store_16(event, 19, channel->local_mtu); 2105 little_endian_store_16(event, 21, channel->remote_mtu); 2106 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2107 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2108 } 2109 2110 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 2111 btstack_linked_list_iterator_t it; 2112 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2113 while (btstack_linked_list_iterator_has_next(&it)){ 2114 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2115 if ( channel->local_cid == local_cid) { 2116 return channel; 2117 } 2118 } 2119 return NULL; 2120 } 2121 2122 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 2123 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 2124 channel->state = L2CAP_STATE_CLOSED; 2125 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 2126 // discard channel 2127 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2128 btstack_memory_l2cap_channel_free(channel); 2129 } 2130 2131 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 2132 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 2133 } 2134 2135 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 2136 2137 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 2138 2139 // check for alread registered psm 2140 l2cap_service_t *service = l2cap_le_get_service(psm); 2141 if (service) { 2142 return L2CAP_SERVICE_ALREADY_REGISTERED; 2143 } 2144 2145 // alloc structure 2146 service = btstack_memory_l2cap_service_get(); 2147 if (!service) { 2148 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 2149 return BTSTACK_MEMORY_ALLOC_FAILED; 2150 } 2151 2152 // fill in 2153 service->psm = psm; 2154 service->mtu = 0; 2155 service->packet_handler = packet_handler; 2156 service->required_security_level = security_level; 2157 2158 // add to services list 2159 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 2160 2161 // done 2162 return 0; 2163 } 2164 2165 uint8_t l2cap_le_unregister_service(uint16_t psm) { 2166 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 2167 l2cap_service_t *service = l2cap_le_get_service(psm); 2168 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2169 2170 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 2171 btstack_memory_l2cap_service_free(service); 2172 return 0; 2173 } 2174 2175 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 2176 // get channel 2177 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2178 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2179 2180 // validate state 2181 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2182 return ERROR_CODE_COMMAND_DISALLOWED; 2183 } 2184 2185 // set state accept connection 2186 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 2187 channel->receive_sdu_buffer = receive_sdu_buffer; 2188 channel->local_mtu = mtu; 2189 channel->new_credits_incoming = initial_credits; 2190 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2191 2192 // test 2193 // channel->new_credits_incoming = 1; 2194 2195 // go 2196 l2cap_run(); 2197 return 0; 2198 } 2199 2200 /** 2201 * @brief Deny incoming LE Data Channel connection due to resource constraints 2202 * @param local_cid L2CAP LE Data Channel Identifier 2203 */ 2204 2205 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 2206 // get channel 2207 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2208 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2209 2210 // validate state 2211 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2212 return ERROR_CODE_COMMAND_DISALLOWED; 2213 } 2214 2215 // set state decline connection 2216 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 2217 channel->reason = 0x04; // no resources available 2218 l2cap_run(); 2219 return 0; 2220 } 2221 2222 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 2223 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 2224 uint16_t * out_local_cid) { 2225 2226 log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 2227 2228 2229 hci_connection_t * connection = hci_connection_for_handle(con_handle); 2230 if (!connection) { 2231 log_error("no hci_connection for handle 0x%04x", con_handle); 2232 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 2233 } 2234 2235 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, connection->address, connection->address_type, psm, mtu, security_level); 2236 if (!channel) { 2237 return BTSTACK_MEMORY_ALLOC_FAILED; 2238 } 2239 log_info("l2cap_le_create_channel %p", channel); 2240 2241 // store local_cid 2242 if (out_local_cid){ 2243 *out_local_cid = channel->local_cid; 2244 } 2245 2246 // provide buffer 2247 channel->con_handle = con_handle; 2248 channel->receive_sdu_buffer = receive_sdu_buffer; 2249 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 2250 channel->new_credits_incoming = initial_credits; 2251 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2252 2253 // add to connections list 2254 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2255 2256 // go 2257 l2cap_run(); 2258 return 0; 2259 } 2260 2261 /** 2262 * @brief Provide credtis for LE Data Channel 2263 * @param local_cid L2CAP LE Data Channel Identifier 2264 * @param credits Number additional credits for peer 2265 */ 2266 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 2267 2268 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2269 if (!channel) { 2270 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2271 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2272 } 2273 2274 // check state 2275 if (channel->state != L2CAP_STATE_OPEN){ 2276 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 2277 } 2278 2279 // assert incoming credits + credits <= 0xffff 2280 uint32_t total_credits = channel->credits_incoming; 2281 total_credits += channel->new_credits_incoming; 2282 total_credits += credits; 2283 if (total_credits > 0xffff){ 2284 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 2285 channel->new_credits_incoming, credits); 2286 } 2287 2288 // set credits_granted 2289 channel->new_credits_incoming += credits; 2290 2291 // go 2292 l2cap_run(); 2293 return 0; 2294 } 2295 2296 /** 2297 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 2298 * @param local_cid L2CAP LE Data Channel Identifier 2299 */ 2300 int l2cap_le_can_send_now(uint16_t local_cid){ 2301 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2302 if (!channel) { 2303 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2304 return 0; 2305 } 2306 2307 // check state 2308 if (channel->state != L2CAP_STATE_OPEN) return 0; 2309 2310 // check queue 2311 if (channel->send_sdu_buffer) return 0; 2312 2313 // fine, go ahead 2314 return 1; 2315 } 2316 2317 /** 2318 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 2319 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 2320 * so packet handler should be ready to handle it 2321 * @param local_cid L2CAP LE Data Channel Identifier 2322 */ 2323 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 2324 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2325 if (!channel) { 2326 log_error("l2cap_le_request_can_send_now_event no channel for cid 0x%02x", local_cid); 2327 return 0; 2328 } 2329 channel->waiting_for_can_send_now = 1; 2330 l2cap_le_notify_channel_can_send(channel); 2331 return 0; 2332 } 2333 2334 /** 2335 * @brief Send data via LE Data Channel 2336 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 2337 * @param local_cid L2CAP LE Data Channel Identifier 2338 * @param data data to send 2339 * @param size data size 2340 */ 2341 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 2342 2343 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2344 if (!channel) { 2345 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2346 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2347 } 2348 2349 if (len > channel->remote_mtu){ 2350 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 2351 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 2352 } 2353 2354 if (channel->send_sdu_buffer){ 2355 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 2356 return BTSTACK_ACL_BUFFERS_FULL; 2357 } 2358 2359 channel->send_sdu_buffer = data; 2360 channel->send_sdu_len = len; 2361 channel->send_sdu_pos = 0; 2362 2363 l2cap_run(); 2364 return 0; 2365 } 2366 2367 /** 2368 * @brief Disconnect from LE Data Channel 2369 * @param local_cid L2CAP LE Data Channel Identifier 2370 */ 2371 uint8_t l2cap_le_disconnect(uint16_t local_cid) 2372 { 2373 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2374 if (!channel) { 2375 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2376 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2377 } 2378 2379 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2380 l2cap_run(); 2381 return 0; 2382 } 2383 2384 #endif 2385