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 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 618 features |= 0x0008; 619 #endif 620 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 621 } 622 break; 623 case 3: { // Fixed Channels Supported 624 uint8_t map[8]; 625 memset(map, 0, 8); 626 map[0] = 0x06; // L2CAP Signaling Channel (0x02) + Connectionless reception (0x04) 627 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 628 } 629 break; 630 default: 631 // all other types are not supported 632 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 633 break; 634 } 635 break; 636 case COMMAND_REJECT: 637 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 638 break; 639 #endif 640 #ifdef ENABLE_BLE 641 case LE_CREDIT_BASED_CONNECTION_REQUEST: 642 l2cap_send_le_signaling_packet(handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, sig_id, 0, 0, 0, 0, result); 643 break; 644 case COMMAND_REJECT_LE: 645 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 646 break; 647 #endif 648 default: 649 // should not happen 650 break; 651 } 652 } 653 654 btstack_linked_list_iterator_t it; 655 UNUSED(it); 656 657 #ifdef ENABLE_CLASSIC 658 uint8_t config_options[10]; 659 btstack_linked_list_iterator_init(&it, &l2cap_channels); 660 while (btstack_linked_list_iterator_has_next(&it)){ 661 662 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 663 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 664 switch (channel->state){ 665 666 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 667 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 668 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 669 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 670 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 671 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 672 } 673 break; 674 675 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 676 if (!hci_can_send_command_packet_now()) break; 677 // send connection request - set state first 678 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 679 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 680 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 681 break; 682 683 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 684 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 685 channel->state = L2CAP_STATE_INVALID; 686 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 687 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 688 l2cap_stop_rtx(channel); 689 btstack_linked_list_iterator_remove(&it); 690 btstack_memory_l2cap_channel_free(channel); 691 break; 692 693 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 694 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 695 channel->state = L2CAP_STATE_CONFIG; 696 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 697 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 698 break; 699 700 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 701 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 702 // success, start l2cap handshake 703 channel->local_sig_id = l2cap_next_sig_id(); 704 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 705 l2cap_send_signaling_packet( channel->con_handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 706 l2cap_start_rtx(channel); 707 break; 708 709 case L2CAP_STATE_CONFIG: 710 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 711 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 712 uint16_t flags = 0; 713 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 714 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 715 flags = 1; 716 } else { 717 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 718 } 719 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 720 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 721 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 722 config_options[0] = 1; // MTU 723 config_options[1] = 2; // len param 724 little_endian_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 725 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 726 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 727 } else { 728 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 729 } 730 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 731 } 732 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 733 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 734 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 735 channel->local_sig_id = l2cap_next_sig_id(); 736 int send_retransmission_and_flow_control_option = 0; 737 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 738 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 739 send_retransmission_and_flow_control_option = 1; 740 } 741 #endif 742 if (send_retransmission_and_flow_control_option){ 743 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 744 config_options[0] = 0x04; // RETRANSMISSION AND FLOW CONTROL OPTION 745 config_options[1] = 9; // length 746 config_options[2] = (uint8_t) channel->mode; 747 config_options[3] = 1; // TxWindows size 748 config_options[4] = 1; // max retransmit 749 little_endian_store_16( config_options, 5, 100); // Retransmission timeout: 100 ms 750 little_endian_store_16( config_options, 5, 300); // Monitor timeout: 300 ms 751 little_endian_store_16( config_options, 7, channel->local_mtu); // Max PDU size 752 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 10, &config_options); 753 #endif 754 } else { 755 config_options[0] = 1; // MTU 756 config_options[1] = 2; // len param 757 little_endian_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 758 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 759 } 760 l2cap_start_rtx(channel); 761 } 762 if (l2cap_channel_ready_for_open(channel)){ 763 channel->state = L2CAP_STATE_OPEN; 764 l2cap_emit_channel_opened(channel, 0); // success 765 } 766 break; 767 768 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 769 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 770 channel->state = L2CAP_STATE_INVALID; 771 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 772 // 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 :) 773 l2cap_finialize_channel_close(channel); // -- remove from list 774 break; 775 776 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 777 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 778 channel->local_sig_id = l2cap_next_sig_id(); 779 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 780 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 781 break; 782 default: 783 break; 784 } 785 } 786 #endif 787 788 #ifdef ENABLE_LE_DATA_CHANNELS 789 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 790 while (btstack_linked_list_iterator_has_next(&it)){ 791 uint8_t * acl_buffer; 792 uint8_t * l2cap_payload; 793 uint16_t pos; 794 uint16_t payload_size; 795 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 796 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 797 switch (channel->state){ 798 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 799 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 800 channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; 801 // le psm, source cid, mtu, mps, initial credits 802 channel->local_sig_id = l2cap_next_sig_id(); 803 channel->credits_incoming = channel->new_credits_incoming; 804 channel->new_credits_incoming = 0; 805 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); 806 break; 807 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 808 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 809 // TODO: support larger MPS 810 channel->state = L2CAP_STATE_OPEN; 811 channel->credits_incoming = channel->new_credits_incoming; 812 channel->new_credits_incoming = 0; 813 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); 814 // notify client 815 l2cap_emit_le_channel_opened(channel, 0); 816 break; 817 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 818 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 819 channel->state = L2CAP_STATE_INVALID; 820 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, 0, 0, channel->reason); 821 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 822 l2cap_stop_rtx(channel); 823 btstack_linked_list_iterator_remove(&it); 824 btstack_memory_l2cap_channel_free(channel); 825 break; 826 case L2CAP_STATE_OPEN: 827 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 828 829 // send credits 830 if (channel->new_credits_incoming){ 831 log_info("l2cap: sending %u credits", channel->new_credits_incoming); 832 channel->local_sig_id = l2cap_next_sig_id(); 833 uint16_t new_credits = channel->new_credits_incoming; 834 channel->new_credits_incoming = 0; 835 channel->credits_incoming += new_credits; 836 l2cap_send_le_signaling_packet(channel->con_handle, LE_FLOW_CONTROL_CREDIT, channel->local_sig_id, channel->remote_cid, new_credits); 837 break; 838 } 839 840 // send data 841 if (!channel->send_sdu_buffer) break; 842 if (!channel->credits_outgoing) break; 843 844 // send part of SDU 845 hci_reserve_packet_buffer(); 846 acl_buffer = hci_get_outgoing_packet_buffer(); 847 l2cap_payload = acl_buffer + 8; 848 pos = 0; 849 if (!channel->send_sdu_pos){ 850 // store SDU len 851 channel->send_sdu_pos += 2; 852 little_endian_store_16(l2cap_payload, pos, channel->send_sdu_len); 853 pos += 2; 854 } 855 payload_size = btstack_min(channel->send_sdu_len + 2 - channel->send_sdu_pos, channel->remote_mps - pos); 856 log_info("len %u, pos %u => payload %u, credits %u", channel->send_sdu_len, channel->send_sdu_pos, payload_size, channel->credits_outgoing); 857 memcpy(&l2cap_payload[pos], &channel->send_sdu_buffer[channel->send_sdu_pos-2], payload_size); // -2 for virtual SDU len 858 pos += payload_size; 859 channel->send_sdu_pos += payload_size; 860 l2cap_setup_header(acl_buffer, channel->con_handle, 0, channel->remote_cid, pos); 861 // done 862 863 channel->credits_outgoing--; 864 865 if (channel->send_sdu_pos >= channel->send_sdu_len + 2){ 866 channel->send_sdu_buffer = NULL; 867 // send done event 868 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_PACKET_SENT); 869 // inform about can send now 870 l2cap_le_notify_channel_can_send(channel); 871 } 872 hci_send_acl_packet_buffer(8 + pos); 873 break; 874 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 875 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 876 channel->local_sig_id = l2cap_next_sig_id(); 877 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 878 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 879 break; 880 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 881 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 882 channel->state = L2CAP_STATE_INVALID; 883 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 884 l2cap_le_finialize_channel_close(channel); // -- remove from list 885 break; 886 default: 887 break; 888 } 889 } 890 #endif 891 892 #ifdef ENABLE_BLE 893 // send l2cap con paramter update if necessary 894 hci_connections_get_iterator(&it); 895 while(btstack_linked_list_iterator_has_next(&it)){ 896 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 897 if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; 898 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 899 switch (connection->le_con_parameter_update_state){ 900 case CON_PARAMETER_UPDATE_SEND_REQUEST: 901 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 902 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, connection->le_con_param_update_identifier, 903 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 904 break; 905 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 906 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 907 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 908 break; 909 case CON_PARAMETER_UPDATE_DENY: 910 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 911 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 912 break; 913 default: 914 break; 915 } 916 } 917 #endif 918 919 // log_info("l2cap_run: exit"); 920 } 921 922 #ifdef ENABLE_CLASSIC 923 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 924 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 925 log_info("l2cap_handle_connection_complete expected state"); 926 // success, start l2cap handshake 927 channel->con_handle = con_handle; 928 // check remote SSP feature first 929 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 930 } 931 } 932 933 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 934 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 935 936 // we have been waiting for remote supported features, if both support SSP, 937 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)); 938 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 939 // request security level 2 940 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 941 gap_request_security_level(channel->con_handle, LEVEL_2); 942 return; 943 } 944 // fine, go ahead 945 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 946 } 947 #endif 948 949 #ifdef L2CAP_USES_CHANNELS 950 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 951 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 952 953 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 954 if (!channel) { 955 return NULL; 956 } 957 958 // Init memory (make valgrind happy) 959 memset(channel, 0, sizeof(l2cap_channel_t)); 960 961 // fill in 962 channel->packet_handler = packet_handler; 963 bd_addr_copy(channel->address, address); 964 channel->address_type = address_type; 965 channel->psm = psm; 966 channel->local_mtu = local_mtu; 967 channel->remote_mtu = L2CAP_MINIMAL_MTU; 968 channel->required_security_level = security_level; 969 970 // 971 channel->local_cid = l2cap_next_local_cid(); 972 channel->con_handle = 0; 973 974 // set initial state 975 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 976 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 977 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 978 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 979 return channel; 980 } 981 #endif 982 983 #ifdef ENABLE_CLASSIC 984 985 /** 986 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 987 * @param packet_handler 988 * @param address 989 * @param psm 990 * @param mtu 991 * @param local_cid 992 */ 993 994 uint8_t l2cap_create_channel(btstack_packet_handler_t channel_packet_handler, bd_addr_t address, uint16_t psm, uint16_t mtu, uint16_t * out_local_cid){ 995 // limit MTU to the size of our outtgoing HCI buffer 996 uint16_t local_mtu = btstack_min(mtu, l2cap_max_mtu()); 997 998 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u -> local mtu %u", bd_addr_to_str(address), psm, mtu, local_mtu); 999 1000 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 1001 if (!channel) { 1002 return BTSTACK_MEMORY_ALLOC_FAILED; 1003 } 1004 1005 // add to connections list 1006 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1007 1008 // store local_cid 1009 if (out_local_cid){ 1010 *out_local_cid = channel->local_cid; 1011 } 1012 1013 // check if hci connection is already usable 1014 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 1015 if (conn){ 1016 log_info("l2cap_create_channel, hci connection already exists"); 1017 l2cap_handle_connection_complete(conn->con_handle, channel); 1018 // check if remote supported fearures are already received 1019 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 1020 l2cap_handle_remote_supported_features_received(channel); 1021 } 1022 } 1023 1024 l2cap_run(); 1025 1026 return 0; 1027 } 1028 1029 void 1030 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 1031 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 1032 // find channel for local_cid 1033 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1034 if (channel) { 1035 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1036 } 1037 // process 1038 l2cap_run(); 1039 } 1040 1041 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 1042 btstack_linked_list_iterator_t it; 1043 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1044 while (btstack_linked_list_iterator_has_next(&it)){ 1045 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1046 if ( bd_addr_cmp( channel->address, address) != 0) continue; 1047 // channel for this address found 1048 switch (channel->state){ 1049 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 1050 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1051 // failure, forward error code 1052 l2cap_emit_channel_opened(channel, status); 1053 // discard channel 1054 l2cap_stop_rtx(channel); 1055 btstack_linked_list_iterator_remove(&it); 1056 btstack_memory_l2cap_channel_free(channel); 1057 break; 1058 default: 1059 break; 1060 } 1061 } 1062 } 1063 1064 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1065 btstack_linked_list_iterator_t it; 1066 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1067 while (btstack_linked_list_iterator_has_next(&it)){ 1068 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1069 if ( ! bd_addr_cmp( channel->address, address) ){ 1070 l2cap_handle_connection_complete(handle, channel); 1071 } 1072 } 1073 // process 1074 l2cap_run(); 1075 } 1076 #endif 1077 1078 static void l2cap_notify_channel_can_send(void){ 1079 1080 #ifdef ENABLE_CLASSIC 1081 btstack_linked_list_iterator_t it; 1082 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1083 while (btstack_linked_list_iterator_has_next(&it)){ 1084 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1085 if (!channel->waiting_for_can_send_now) continue; 1086 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1087 channel->waiting_for_can_send_now = 0; 1088 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1089 } 1090 #endif 1091 1092 int i; 1093 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1094 if (!fixed_channels[i].callback) continue; 1095 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1096 int can_send = 0; 1097 if (l2cap_fixed_channel_table_index_is_le(i)){ 1098 #ifdef ENABLE_BLE 1099 can_send = hci_can_send_acl_le_packet_now(); 1100 #endif 1101 } else { 1102 #ifdef ENABLE_CLASSIC 1103 can_send = hci_can_send_acl_classic_packet_now(); 1104 #endif 1105 } 1106 if (!can_send) continue; 1107 fixed_channels[i].waiting_for_can_send_now = 0; 1108 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1109 } 1110 } 1111 1112 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1113 1114 UNUSED(packet_type); 1115 UNUSED(cid); 1116 UNUSED(size); 1117 1118 bd_addr_t address; 1119 hci_con_handle_t handle; 1120 int hci_con_used; 1121 btstack_linked_list_iterator_t it; 1122 1123 // avoid unused warnings 1124 UNUSED(address); 1125 UNUSED(hci_con_used); 1126 UNUSED(it); 1127 UNUSED(handle); 1128 1129 switch(hci_event_packet_get_type(packet)){ 1130 1131 // Notify channel packet handler if they can send now 1132 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1133 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1134 l2cap_run(); // try sending signaling packets first 1135 l2cap_notify_channel_can_send(); 1136 break; 1137 1138 case HCI_EVENT_COMMAND_STATUS: 1139 l2cap_run(); // try sending signaling packets first 1140 break; 1141 1142 #ifdef ENABLE_CLASSIC 1143 // handle connection complete events 1144 case HCI_EVENT_CONNECTION_COMPLETE: 1145 reverse_bd_addr(&packet[5], address); 1146 if (packet[2] == 0){ 1147 handle = little_endian_read_16(packet, 3); 1148 l2cap_handle_connection_success_for_addr(address, handle); 1149 } else { 1150 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1151 } 1152 break; 1153 1154 // handle successful create connection cancel command 1155 case HCI_EVENT_COMMAND_COMPLETE: 1156 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1157 if (packet[5] == 0){ 1158 reverse_bd_addr(&packet[6], address); 1159 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1160 l2cap_handle_connection_failed_for_addr(address, 0x16); 1161 } 1162 } 1163 l2cap_run(); // try sending signaling packets first 1164 break; 1165 #endif 1166 1167 // handle disconnection complete events 1168 case HCI_EVENT_DISCONNECTION_COMPLETE: 1169 // send l2cap disconnect events for all channels on this handle and free them 1170 #ifdef ENABLE_CLASSIC 1171 handle = little_endian_read_16(packet, 3); 1172 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1173 while (btstack_linked_list_iterator_has_next(&it)){ 1174 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1175 if (channel->con_handle != handle) continue; 1176 l2cap_emit_channel_closed(channel); 1177 l2cap_stop_rtx(channel); 1178 btstack_linked_list_iterator_remove(&it); 1179 btstack_memory_l2cap_channel_free(channel); 1180 } 1181 #endif 1182 #ifdef ENABLE_LE_DATA_CHANNELS 1183 handle = little_endian_read_16(packet, 3); 1184 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1185 while (btstack_linked_list_iterator_has_next(&it)){ 1186 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1187 if (channel->con_handle != handle) continue; 1188 l2cap_emit_channel_closed(channel); 1189 btstack_linked_list_iterator_remove(&it); 1190 btstack_memory_l2cap_channel_free(channel); 1191 } 1192 #endif 1193 break; 1194 1195 // HCI Connection Timeouts 1196 #ifdef ENABLE_CLASSIC 1197 case L2CAP_EVENT_TIMEOUT_CHECK: 1198 handle = little_endian_read_16(packet, 2); 1199 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1200 if (hci_authentication_active_for_handle(handle)) break; 1201 hci_con_used = 0; 1202 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1203 while (btstack_linked_list_iterator_has_next(&it)){ 1204 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1205 if (channel->con_handle != handle) continue; 1206 hci_con_used = 1; 1207 break; 1208 } 1209 if (hci_con_used) break; 1210 if (!hci_can_send_command_packet_now()) break; 1211 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1212 break; 1213 1214 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1215 handle = little_endian_read_16(packet, 3); 1216 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1217 while (btstack_linked_list_iterator_has_next(&it)){ 1218 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1219 if (channel->con_handle != handle) continue; 1220 l2cap_handle_remote_supported_features_received(channel); 1221 break; 1222 } 1223 break; 1224 1225 case GAP_EVENT_SECURITY_LEVEL: 1226 handle = little_endian_read_16(packet, 2); 1227 log_info("l2cap - security level update"); 1228 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1229 while (btstack_linked_list_iterator_has_next(&it)){ 1230 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1231 if (channel->con_handle != handle) continue; 1232 1233 log_info("l2cap - state %u", channel->state); 1234 1235 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1236 gap_security_level_t required_level = channel->required_security_level; 1237 1238 switch (channel->state){ 1239 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1240 if (actual_level >= required_level){ 1241 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1242 l2cap_emit_incoming_connection(channel); 1243 } else { 1244 channel->reason = 0x0003; // security block 1245 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1246 } 1247 break; 1248 1249 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1250 if (actual_level >= required_level){ 1251 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1252 } else { 1253 // disconnnect, authentication not good enough 1254 hci_disconnect_security_block(handle); 1255 } 1256 break; 1257 1258 default: 1259 break; 1260 } 1261 } 1262 break; 1263 #endif 1264 1265 default: 1266 break; 1267 } 1268 1269 l2cap_run(); 1270 } 1271 1272 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t cid, uint16_t data){ 1273 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1274 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1275 signaling_responses[signaling_responses_pending].handle = handle; 1276 signaling_responses[signaling_responses_pending].code = code; 1277 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1278 signaling_responses[signaling_responses_pending].cid = cid; 1279 signaling_responses[signaling_responses_pending].data = data; 1280 signaling_responses_pending++; 1281 l2cap_run(); 1282 } 1283 } 1284 1285 #ifdef ENABLE_CLASSIC 1286 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1287 channel->remote_sig_id = identifier; 1288 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1289 l2cap_run(); 1290 } 1291 1292 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1293 1294 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1295 l2cap_service_t *service = l2cap_get_service(psm); 1296 if (!service) { 1297 // 0x0002 PSM not supported 1298 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 1299 return; 1300 } 1301 1302 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1303 if (!hci_connection) { 1304 // 1305 log_error("no hci_connection for handle %u", handle); 1306 return; 1307 } 1308 1309 // alloc structure 1310 // log_info("l2cap_handle_connection_request register channel"); 1311 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 1312 psm, service->mtu, service->required_security_level); 1313 if (!channel){ 1314 // 0x0004 No resources available 1315 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 1316 return; 1317 } 1318 1319 channel->con_handle = handle; 1320 channel->remote_cid = source_cid; 1321 channel->remote_sig_id = sig_id; 1322 1323 // limit local mtu to max acl packet length - l2cap header 1324 if (channel->local_mtu > l2cap_max_mtu()) { 1325 channel->local_mtu = l2cap_max_mtu(); 1326 } 1327 1328 // set initial state 1329 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1330 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND | L2CAP_CHANNEL_STATE_VAR_INCOMING); 1331 1332 // add to connections list 1333 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1334 1335 // assert security requirements 1336 gap_request_security_level(handle, channel->required_security_level); 1337 } 1338 1339 void l2cap_accept_connection(uint16_t local_cid){ 1340 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1341 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1342 if (!channel) { 1343 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1344 return; 1345 } 1346 1347 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1348 // configure L2CAP Basic mode 1349 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1350 #endif 1351 1352 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1353 1354 // process 1355 l2cap_run(); 1356 } 1357 1358 1359 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1360 void l2cap_accept_ertm_connection(uint16_t local_cid){ 1361 log_info("L2CAP_ACCEPT_ERTM_CONNECTION local_cid 0x%x", local_cid); 1362 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1363 if (!channel) { 1364 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1365 return; 1366 } 1367 1368 // configure L2CAP ERTM 1369 channel->mode = L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION; 1370 1371 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1372 1373 // process 1374 l2cap_run(); 1375 } 1376 #endif 1377 1378 1379 void l2cap_decline_connection(uint16_t local_cid){ 1380 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 1381 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1382 if (!channel) { 1383 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1384 return; 1385 } 1386 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1387 channel->reason = 0x04; // no resources available 1388 l2cap_run(); 1389 } 1390 1391 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1392 1393 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1394 1395 uint16_t flags = little_endian_read_16(command, 6); 1396 if (flags & 1) { 1397 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1398 } 1399 1400 // accept the other's configuration options 1401 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1402 uint16_t pos = 8; 1403 while (pos < end_pos){ 1404 uint8_t option_hint = command[pos] >> 7; 1405 uint8_t option_type = command[pos] & 0x7f; 1406 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1407 pos++; 1408 uint8_t length = command[pos++]; 1409 // MTU { type(8): 1, len(8):2, MTU(16) } 1410 if (option_type == 1 && length == 2){ 1411 channel->remote_mtu = little_endian_read_16(command, pos); 1412 if (channel->remote_mtu > l2cap_max_mtu()){ 1413 log_info("Remote MTU %u larger than outgoing buffer, only using MTU = %u", channel->remote_mtu, l2cap_max_mtu()); 1414 channel->remote_mtu = l2cap_max_mtu(); 1415 } 1416 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1417 } 1418 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1419 if (option_type == 2 && length == 2){ 1420 channel->flush_timeout = little_endian_read_16(command, pos); 1421 } 1422 // check for unknown options 1423 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1424 log_info("l2cap cid %u, unknown options", channel->local_cid); 1425 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1426 } 1427 pos += length; 1428 } 1429 } 1430 1431 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1432 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1433 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1434 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1435 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 1436 if (channel->state == L2CAP_STATE_OPEN) return 0; 1437 return 1; 1438 } 1439 1440 1441 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1442 1443 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1444 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1445 uint16_t result = 0; 1446 1447 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1448 1449 // handle DISCONNECT REQUESTS seperately 1450 if (code == DISCONNECTION_REQUEST){ 1451 switch (channel->state){ 1452 case L2CAP_STATE_CONFIG: 1453 case L2CAP_STATE_OPEN: 1454 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1455 case L2CAP_STATE_WAIT_DISCONNECT: 1456 l2cap_handle_disconnect_request(channel, identifier); 1457 break; 1458 1459 default: 1460 // ignore in other states 1461 break; 1462 } 1463 return; 1464 } 1465 1466 // @STATEMACHINE(l2cap) 1467 switch (channel->state) { 1468 1469 case L2CAP_STATE_WAIT_CONNECT_RSP: 1470 switch (code){ 1471 case CONNECTION_RESPONSE: 1472 l2cap_stop_rtx(channel); 1473 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1474 switch (result) { 1475 case 0: 1476 // successful connection 1477 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1478 channel->state = L2CAP_STATE_CONFIG; 1479 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1480 break; 1481 case 1: 1482 // connection pending. get some coffee, but start the ERTX 1483 l2cap_start_ertx(channel); 1484 break; 1485 default: 1486 // channel closed 1487 channel->state = L2CAP_STATE_CLOSED; 1488 // map l2cap connection response result to BTstack status enumeration 1489 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1490 1491 // drop link key if security block 1492 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1493 gap_drop_link_key_for_bd_addr(channel->address); 1494 } 1495 1496 // discard channel 1497 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1498 btstack_memory_l2cap_channel_free(channel); 1499 break; 1500 } 1501 break; 1502 1503 default: 1504 //@TODO: implement other signaling packets 1505 break; 1506 } 1507 break; 1508 1509 case L2CAP_STATE_CONFIG: 1510 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1511 switch (code) { 1512 case CONFIGURE_REQUEST: 1513 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1514 l2cap_signaling_handle_configure_request(channel, command); 1515 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1516 // only done if continuation not set 1517 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1518 } 1519 break; 1520 case CONFIGURE_RESPONSE: 1521 l2cap_stop_rtx(channel); 1522 switch (result){ 1523 case 0: // success 1524 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1525 break; 1526 case 4: // pending 1527 l2cap_start_ertx(channel); 1528 break; 1529 default: 1530 // retry on negative result 1531 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1532 break; 1533 } 1534 break; 1535 default: 1536 break; 1537 } 1538 if (l2cap_channel_ready_for_open(channel)){ 1539 // for open: 1540 channel->state = L2CAP_STATE_OPEN; 1541 l2cap_emit_channel_opened(channel, 0); 1542 } 1543 break; 1544 1545 case L2CAP_STATE_WAIT_DISCONNECT: 1546 switch (code) { 1547 case DISCONNECTION_RESPONSE: 1548 l2cap_finialize_channel_close(channel); 1549 break; 1550 default: 1551 //@TODO: implement other signaling packets 1552 break; 1553 } 1554 break; 1555 1556 case L2CAP_STATE_CLOSED: 1557 // @TODO handle incoming requests 1558 break; 1559 1560 case L2CAP_STATE_OPEN: 1561 //@TODO: implement other signaling packets, e.g. re-configure 1562 break; 1563 default: 1564 break; 1565 } 1566 // log_info("new state %u", channel->state); 1567 } 1568 1569 1570 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1571 1572 // get code, signalind identifier and command len 1573 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1574 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1575 1576 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1577 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1578 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 1579 return; 1580 } 1581 1582 // general commands without an assigned channel 1583 switch(code) { 1584 1585 case CONNECTION_REQUEST: { 1586 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1587 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1588 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1589 return; 1590 } 1591 1592 case ECHO_REQUEST: 1593 l2cap_register_signaling_response(handle, code, sig_id, 0, 0); 1594 return; 1595 1596 case INFORMATION_REQUEST: { 1597 uint16_t infoType = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1598 l2cap_register_signaling_response(handle, code, sig_id, 0, infoType); 1599 return; 1600 } 1601 1602 default: 1603 break; 1604 } 1605 1606 1607 // Get potential destination CID 1608 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1609 1610 // Find channel for this sig_id and connection handle 1611 btstack_linked_list_iterator_t it; 1612 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1613 while (btstack_linked_list_iterator_has_next(&it)){ 1614 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1615 if (channel->con_handle != handle) continue; 1616 if (code & 1) { 1617 // match odd commands (responses) by previous signaling identifier 1618 if (channel->local_sig_id == sig_id) { 1619 l2cap_signaling_handler_channel(channel, command); 1620 break; 1621 } 1622 } else { 1623 // match even commands (requests) by local channel id 1624 if (channel->local_cid == dest_cid) { 1625 l2cap_signaling_handler_channel(channel, command); 1626 break; 1627 } 1628 } 1629 } 1630 } 1631 #endif 1632 1633 #ifdef ENABLE_BLE 1634 1635 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 1636 uint8_t event[6]; 1637 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 1638 event[1] = 4; 1639 little_endian_store_16(event, 2, con_handle); 1640 little_endian_store_16(event, 4, result); 1641 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1642 if (!l2cap_event_packet_handler) return; 1643 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 1644 } 1645 1646 // @returns valid 1647 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 1648 hci_connection_t * connection; 1649 uint16_t result; 1650 uint8_t event[10]; 1651 1652 #ifdef ENABLE_LE_DATA_CHANNELS 1653 btstack_linked_list_iterator_t it; 1654 l2cap_channel_t * channel; 1655 uint16_t local_cid; 1656 uint16_t le_psm; 1657 uint16_t new_credits; 1658 uint16_t credits_before; 1659 l2cap_service_t * service; 1660 uint16_t source_cid; 1661 #endif 1662 1663 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1664 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 1665 1666 switch (code){ 1667 1668 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 1669 result = little_endian_read_16(command, 4); 1670 l2cap_emit_connection_parameter_update_response(handle, result); 1671 break; 1672 1673 case CONNECTION_PARAMETER_UPDATE_REQUEST: 1674 connection = hci_connection_for_handle(handle); 1675 if (connection){ 1676 if (connection->role != HCI_ROLE_MASTER){ 1677 // reject command without notifying upper layer when not in master role 1678 return 0; 1679 } 1680 int update_parameter = 1; 1681 le_connection_parameter_range_t existing_range; 1682 gap_get_connection_parameter_range(&existing_range); 1683 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 1684 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 1685 uint16_t le_conn_latency = little_endian_read_16(command,12); 1686 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 1687 1688 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 1689 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 1690 1691 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 1692 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 1693 1694 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 1695 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 1696 1697 if (update_parameter){ 1698 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 1699 connection->le_conn_interval_min = le_conn_interval_min; 1700 connection->le_conn_interval_max = le_conn_interval_max; 1701 connection->le_conn_latency = le_conn_latency; 1702 connection->le_supervision_timeout = le_supervision_timeout; 1703 } else { 1704 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 1705 } 1706 connection->le_con_param_update_identifier = sig_id; 1707 } 1708 1709 if (!l2cap_event_packet_handler) break; 1710 1711 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 1712 event[1] = 8; 1713 memcpy(&event[2], &command[4], 8); 1714 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1715 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1716 break; 1717 1718 #ifdef ENABLE_LE_DATA_CHANNELS 1719 1720 case COMMAND_REJECT: 1721 // Find channel for this sig_id and connection handle 1722 channel = NULL; 1723 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1724 while (btstack_linked_list_iterator_has_next(&it)){ 1725 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1726 if (a_channel->con_handle != handle) continue; 1727 if (a_channel->local_sig_id != sig_id) continue; 1728 channel = a_channel; 1729 break; 1730 } 1731 if (!channel) break; 1732 1733 // if received while waiting for le connection response, assume legacy device 1734 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 1735 channel->state = L2CAP_STATE_CLOSED; 1736 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 1737 l2cap_emit_le_channel_opened(channel, 0x0002); 1738 1739 // discard channel 1740 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1741 btstack_memory_l2cap_channel_free(channel); 1742 break; 1743 } 1744 break; 1745 1746 case LE_CREDIT_BASED_CONNECTION_REQUEST: 1747 1748 // get hci connection, bail if not found (must not happen) 1749 connection = hci_connection_for_handle(handle); 1750 if (!connection) return 0; 1751 1752 // check if service registered 1753 le_psm = little_endian_read_16(command, 4); 1754 service = l2cap_le_get_service(le_psm); 1755 source_cid = little_endian_read_16(command, 6); 1756 1757 if (service){ 1758 if (source_cid < 0x40){ 1759 // 0x0009 Connection refused - Invalid Source CID 1760 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0009); 1761 return 1; 1762 } 1763 1764 // go through list of channels for this ACL connection and check if we get a match 1765 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1766 while (btstack_linked_list_iterator_has_next(&it)){ 1767 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1768 if (a_channel->con_handle != handle) continue; 1769 if (a_channel->remote_cid != source_cid) continue; 1770 // 0x000a Connection refused - Source CID already allocated 1771 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x000a); 1772 return 1; 1773 } 1774 1775 // security: check encryption 1776 if (service->required_security_level >= LEVEL_2){ 1777 if (sm_encryption_key_size(handle) == 0){ 1778 // 0x0008 Connection refused - insufficient encryption 1779 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0008); 1780 return 1; 1781 } 1782 // anything less than 16 byte key size is insufficient 1783 if (sm_encryption_key_size(handle) < 16){ 1784 // 0x0007 Connection refused – insufficient encryption key size 1785 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0007); 1786 return 1; 1787 } 1788 } 1789 1790 // security: check authencation 1791 if (service->required_security_level >= LEVEL_3){ 1792 if (!sm_authenticated(handle)){ 1793 // 0x0005 Connection refused – insufficient authentication 1794 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0005); 1795 return 1; 1796 } 1797 } 1798 1799 // security: check authorization 1800 if (service->required_security_level >= LEVEL_4){ 1801 if (sm_authorization_state(handle) != AUTHORIZATION_GRANTED){ 1802 // 0x0006 Connection refused – insufficient authorization 1803 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0006); 1804 return 1; 1805 } 1806 } 1807 1808 // allocate channel 1809 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 1810 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 1811 if (!channel){ 1812 // 0x0004 Connection refused – no resources available 1813 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 1814 return 1; 1815 } 1816 1817 channel->con_handle = handle; 1818 channel->remote_cid = source_cid; 1819 channel->remote_sig_id = sig_id; 1820 channel->remote_mtu = little_endian_read_16(command, 8); 1821 channel->remote_mps = little_endian_read_16(command, 10); 1822 channel->credits_outgoing = little_endian_read_16(command, 12); 1823 1824 // set initial state 1825 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1826 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_INCOMING; 1827 1828 // add to connections list 1829 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1830 1831 // post connection request event 1832 l2cap_emit_le_incoming_connection(channel); 1833 1834 } else { 1835 // Connection refused – LE_PSM not supported 1836 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 1837 } 1838 break; 1839 1840 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 1841 // Find channel for this sig_id and connection handle 1842 channel = NULL; 1843 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1844 while (btstack_linked_list_iterator_has_next(&it)){ 1845 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1846 if (a_channel->con_handle != handle) continue; 1847 if (a_channel->local_sig_id != sig_id) continue; 1848 channel = a_channel; 1849 break; 1850 } 1851 if (!channel) break; 1852 1853 // cid + 0 1854 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 1855 if (result){ 1856 channel->state = L2CAP_STATE_CLOSED; 1857 // map l2cap connection response result to BTstack status enumeration 1858 l2cap_emit_le_channel_opened(channel, result); 1859 1860 // discard channel 1861 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1862 btstack_memory_l2cap_channel_free(channel); 1863 break; 1864 } 1865 1866 // success 1867 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1868 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1869 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 1870 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 1871 channel->state = L2CAP_STATE_OPEN; 1872 l2cap_emit_le_channel_opened(channel, result); 1873 break; 1874 1875 case LE_FLOW_CONTROL_CREDIT: 1876 // find channel 1877 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1878 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1879 if (!channel) { 1880 log_error("l2cap: no channel for cid 0x%02x", local_cid); 1881 break; 1882 } 1883 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1884 credits_before = channel->credits_outgoing; 1885 channel->credits_outgoing += new_credits; 1886 // check for credit overrun 1887 if (credits_before > channel->credits_outgoing){ 1888 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 1889 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1890 break; 1891 } 1892 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 1893 break; 1894 1895 case DISCONNECTION_REQUEST: 1896 // find channel 1897 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1898 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1899 if (!channel) { 1900 log_error("l2cap: no channel for cid 0x%02x", local_cid); 1901 break; 1902 } 1903 channel->remote_sig_id = sig_id; 1904 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1905 break; 1906 1907 #endif 1908 1909 case DISCONNECTION_RESPONSE: 1910 break; 1911 1912 default: 1913 // command unknown -> reject command 1914 return 0; 1915 } 1916 return 1; 1917 } 1918 #endif 1919 1920 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 1921 UNUSED(packet_type); 1922 UNUSED(channel); 1923 1924 l2cap_channel_t * l2cap_channel; 1925 UNUSED(l2cap_channel); 1926 1927 // Get Channel ID 1928 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1929 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1930 1931 switch (channel_id) { 1932 1933 #ifdef ENABLE_CLASSIC 1934 case L2CAP_CID_SIGNALING: { 1935 uint16_t command_offset = 8; 1936 while (command_offset < size) { 1937 // handle signaling commands 1938 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1939 1940 // increment command_offset 1941 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1942 } 1943 break; 1944 } 1945 #endif 1946 1947 #ifdef ENABLE_BLE 1948 case L2CAP_CID_SIGNALING_LE: { 1949 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1950 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 1951 if (!valid){ 1952 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 1953 } 1954 break; 1955 } 1956 #endif 1957 1958 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1959 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 1960 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1961 } 1962 break; 1963 1964 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1965 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 1966 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1967 } 1968 break; 1969 1970 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 1971 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 1972 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1973 } 1974 break; 1975 1976 default: 1977 #ifdef ENABLE_CLASSIC 1978 // Find channel for this channel_id and connection handle 1979 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 1980 if (l2cap_channel) { 1981 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1982 } 1983 #endif 1984 #ifdef ENABLE_LE_DATA_CHANNELS 1985 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 1986 if (l2cap_channel) { 1987 // credit counting 1988 if (l2cap_channel->credits_incoming == 0){ 1989 log_error("LE Data Channel packet received but no incoming credits"); 1990 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1991 break; 1992 } 1993 l2cap_channel->credits_incoming--; 1994 1995 // automatic credits 1996 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 1997 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 1998 } 1999 2000 // first fragment 2001 uint16_t pos = 0; 2002 if (!l2cap_channel->receive_sdu_len){ 2003 l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 2004 l2cap_channel->receive_sdu_pos = 0; 2005 pos += 2; 2006 size -= 2; 2007 } 2008 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); 2009 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 2010 // done? 2011 log_info("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 2012 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 2013 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 2014 l2cap_channel->receive_sdu_len = 0; 2015 } 2016 } else { 2017 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 2018 } 2019 #endif 2020 break; 2021 } 2022 2023 l2cap_run(); 2024 } 2025 2026 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 2027 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 2028 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 2029 if (index < 0) return; 2030 fixed_channels[index].callback = the_packet_handler; 2031 } 2032 2033 #ifdef ENABLE_CLASSIC 2034 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 2035 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 2036 channel->state = L2CAP_STATE_CLOSED; 2037 l2cap_emit_channel_closed(channel); 2038 // discard channel 2039 l2cap_stop_rtx(channel); 2040 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2041 btstack_memory_l2cap_channel_free(channel); 2042 } 2043 2044 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 2045 btstack_linked_list_iterator_t it; 2046 btstack_linked_list_iterator_init(&it, services); 2047 while (btstack_linked_list_iterator_has_next(&it)){ 2048 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 2049 if ( service->psm == psm){ 2050 return service; 2051 }; 2052 } 2053 return NULL; 2054 } 2055 2056 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 2057 return l2cap_get_service_internal(&l2cap_services, psm); 2058 } 2059 2060 2061 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 2062 2063 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 2064 2065 // check for alread registered psm 2066 l2cap_service_t *service = l2cap_get_service(psm); 2067 if (service) { 2068 log_error("l2cap_register_service: PSM %u already registered", psm); 2069 return L2CAP_SERVICE_ALREADY_REGISTERED; 2070 } 2071 2072 // alloc structure 2073 service = btstack_memory_l2cap_service_get(); 2074 if (!service) { 2075 log_error("l2cap_register_service: no memory for l2cap_service_t"); 2076 return BTSTACK_MEMORY_ALLOC_FAILED; 2077 } 2078 2079 // fill in 2080 service->psm = psm; 2081 service->mtu = mtu; 2082 service->packet_handler = service_packet_handler; 2083 service->required_security_level = security_level; 2084 2085 // add to services list 2086 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 2087 2088 // enable page scan 2089 gap_connectable_control(1); 2090 2091 return 0; 2092 } 2093 2094 uint8_t l2cap_unregister_service(uint16_t psm){ 2095 2096 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 2097 2098 l2cap_service_t *service = l2cap_get_service(psm); 2099 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2100 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 2101 btstack_memory_l2cap_service_free(service); 2102 2103 // disable page scan when no services registered 2104 if (btstack_linked_list_empty(&l2cap_services)) { 2105 gap_connectable_control(0); 2106 } 2107 return 0; 2108 } 2109 #endif 2110 2111 2112 #ifdef ENABLE_LE_DATA_CHANNELS 2113 2114 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel){ 2115 if (!channel->waiting_for_can_send_now) return; 2116 if (channel->send_sdu_buffer) return; 2117 channel->waiting_for_can_send_now = 0; 2118 log_info("L2CAP_EVENT_CHANNEL_LE_CAN_SEND_NOW local_cid 0x%x", channel->local_cid); 2119 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_CAN_SEND_NOW); 2120 } 2121 2122 // 1BH2222 2123 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel) { 2124 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", 2125 channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->remote_mtu); 2126 uint8_t event[19]; 2127 event[0] = L2CAP_EVENT_LE_INCOMING_CONNECTION; 2128 event[1] = sizeof(event) - 2; 2129 event[2] = channel->address_type; 2130 reverse_bd_addr(channel->address, &event[3]); 2131 little_endian_store_16(event, 9, channel->con_handle); 2132 little_endian_store_16(event, 11, channel->psm); 2133 little_endian_store_16(event, 13, channel->local_cid); 2134 little_endian_store_16(event, 15, channel->remote_cid); 2135 little_endian_store_16(event, 17, channel->remote_mtu); 2136 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2137 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2138 } 2139 // 11BH22222 2140 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status) { 2141 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", 2142 status, channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 2143 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu); 2144 uint8_t event[23]; 2145 event[0] = L2CAP_EVENT_LE_CHANNEL_OPENED; 2146 event[1] = sizeof(event) - 2; 2147 event[2] = status; 2148 event[3] = channel->address_type; 2149 reverse_bd_addr(channel->address, &event[4]); 2150 little_endian_store_16(event, 10, channel->con_handle); 2151 event[12] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 2152 little_endian_store_16(event, 13, channel->psm); 2153 little_endian_store_16(event, 15, channel->local_cid); 2154 little_endian_store_16(event, 17, channel->remote_cid); 2155 little_endian_store_16(event, 19, channel->local_mtu); 2156 little_endian_store_16(event, 21, channel->remote_mtu); 2157 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2158 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2159 } 2160 2161 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 2162 btstack_linked_list_iterator_t it; 2163 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2164 while (btstack_linked_list_iterator_has_next(&it)){ 2165 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2166 if ( channel->local_cid == local_cid) { 2167 return channel; 2168 } 2169 } 2170 return NULL; 2171 } 2172 2173 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 2174 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 2175 channel->state = L2CAP_STATE_CLOSED; 2176 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 2177 // discard channel 2178 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2179 btstack_memory_l2cap_channel_free(channel); 2180 } 2181 2182 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 2183 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 2184 } 2185 2186 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 2187 2188 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 2189 2190 // check for alread registered psm 2191 l2cap_service_t *service = l2cap_le_get_service(psm); 2192 if (service) { 2193 return L2CAP_SERVICE_ALREADY_REGISTERED; 2194 } 2195 2196 // alloc structure 2197 service = btstack_memory_l2cap_service_get(); 2198 if (!service) { 2199 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 2200 return BTSTACK_MEMORY_ALLOC_FAILED; 2201 } 2202 2203 // fill in 2204 service->psm = psm; 2205 service->mtu = 0; 2206 service->packet_handler = packet_handler; 2207 service->required_security_level = security_level; 2208 2209 // add to services list 2210 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 2211 2212 // done 2213 return 0; 2214 } 2215 2216 uint8_t l2cap_le_unregister_service(uint16_t psm) { 2217 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 2218 l2cap_service_t *service = l2cap_le_get_service(psm); 2219 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2220 2221 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 2222 btstack_memory_l2cap_service_free(service); 2223 return 0; 2224 } 2225 2226 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 2227 // get channel 2228 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2229 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2230 2231 // validate state 2232 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2233 return ERROR_CODE_COMMAND_DISALLOWED; 2234 } 2235 2236 // set state accept connection 2237 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 2238 channel->receive_sdu_buffer = receive_sdu_buffer; 2239 channel->local_mtu = mtu; 2240 channel->new_credits_incoming = initial_credits; 2241 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2242 2243 // test 2244 // channel->new_credits_incoming = 1; 2245 2246 // go 2247 l2cap_run(); 2248 return 0; 2249 } 2250 2251 /** 2252 * @brief Deny incoming LE Data Channel connection due to resource constraints 2253 * @param local_cid L2CAP LE Data Channel Identifier 2254 */ 2255 2256 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 2257 // get channel 2258 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2259 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2260 2261 // validate state 2262 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2263 return ERROR_CODE_COMMAND_DISALLOWED; 2264 } 2265 2266 // set state decline connection 2267 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 2268 channel->reason = 0x04; // no resources available 2269 l2cap_run(); 2270 return 0; 2271 } 2272 2273 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 2274 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 2275 uint16_t * out_local_cid) { 2276 2277 log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 2278 2279 2280 hci_connection_t * connection = hci_connection_for_handle(con_handle); 2281 if (!connection) { 2282 log_error("no hci_connection for handle 0x%04x", con_handle); 2283 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 2284 } 2285 2286 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, connection->address, connection->address_type, psm, mtu, security_level); 2287 if (!channel) { 2288 return BTSTACK_MEMORY_ALLOC_FAILED; 2289 } 2290 log_info("l2cap_le_create_channel %p", channel); 2291 2292 // store local_cid 2293 if (out_local_cid){ 2294 *out_local_cid = channel->local_cid; 2295 } 2296 2297 // provide buffer 2298 channel->con_handle = con_handle; 2299 channel->receive_sdu_buffer = receive_sdu_buffer; 2300 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 2301 channel->new_credits_incoming = initial_credits; 2302 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2303 2304 // add to connections list 2305 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2306 2307 // go 2308 l2cap_run(); 2309 return 0; 2310 } 2311 2312 /** 2313 * @brief Provide credtis for LE Data Channel 2314 * @param local_cid L2CAP LE Data Channel Identifier 2315 * @param credits Number additional credits for peer 2316 */ 2317 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 2318 2319 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2320 if (!channel) { 2321 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2322 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2323 } 2324 2325 // check state 2326 if (channel->state != L2CAP_STATE_OPEN){ 2327 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 2328 } 2329 2330 // assert incoming credits + credits <= 0xffff 2331 uint32_t total_credits = channel->credits_incoming; 2332 total_credits += channel->new_credits_incoming; 2333 total_credits += credits; 2334 if (total_credits > 0xffff){ 2335 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 2336 channel->new_credits_incoming, credits); 2337 } 2338 2339 // set credits_granted 2340 channel->new_credits_incoming += credits; 2341 2342 // go 2343 l2cap_run(); 2344 return 0; 2345 } 2346 2347 /** 2348 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 2349 * @param local_cid L2CAP LE Data Channel Identifier 2350 */ 2351 int l2cap_le_can_send_now(uint16_t local_cid){ 2352 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2353 if (!channel) { 2354 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2355 return 0; 2356 } 2357 2358 // check state 2359 if (channel->state != L2CAP_STATE_OPEN) return 0; 2360 2361 // check queue 2362 if (channel->send_sdu_buffer) return 0; 2363 2364 // fine, go ahead 2365 return 1; 2366 } 2367 2368 /** 2369 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 2370 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 2371 * so packet handler should be ready to handle it 2372 * @param local_cid L2CAP LE Data Channel Identifier 2373 */ 2374 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 2375 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2376 if (!channel) { 2377 log_error("l2cap_le_request_can_send_now_event no channel for cid 0x%02x", local_cid); 2378 return 0; 2379 } 2380 channel->waiting_for_can_send_now = 1; 2381 l2cap_le_notify_channel_can_send(channel); 2382 return 0; 2383 } 2384 2385 /** 2386 * @brief Send data via LE Data Channel 2387 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 2388 * @param local_cid L2CAP LE Data Channel Identifier 2389 * @param data data to send 2390 * @param size data size 2391 */ 2392 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 2393 2394 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2395 if (!channel) { 2396 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2397 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2398 } 2399 2400 if (len > channel->remote_mtu){ 2401 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 2402 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 2403 } 2404 2405 if (channel->send_sdu_buffer){ 2406 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 2407 return BTSTACK_ACL_BUFFERS_FULL; 2408 } 2409 2410 channel->send_sdu_buffer = data; 2411 channel->send_sdu_len = len; 2412 channel->send_sdu_pos = 0; 2413 2414 l2cap_run(); 2415 return 0; 2416 } 2417 2418 /** 2419 * @brief Disconnect from LE Data Channel 2420 * @param local_cid L2CAP LE Data Channel Identifier 2421 */ 2422 uint8_t l2cap_le_disconnect(uint16_t local_cid) 2423 { 2424 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2425 if (!channel) { 2426 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2427 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2428 } 2429 2430 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2431 l2cap_run(); 2432 return 0; 2433 } 2434 2435 #endif 2436