1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 #define __BTSTACK_FILE__ "l2cap.c" 39 40 /* 41 * l2cap.c 42 * 43 * Logical Link Control and Adaption Protocl (L2CAP) 44 * 45 * Created by Matthias Ringwald on 5/16/09. 46 */ 47 48 #include "l2cap.h" 49 #include "hci.h" 50 #include "hci_dump.h" 51 #include "bluetooth_sdp.h" 52 #include "btstack_debug.h" 53 #include "btstack_event.h" 54 #include "btstack_memory.h" 55 56 #ifdef ENABLE_LE_DATA_CHANNELS 57 #include "ble/sm.h" 58 #endif 59 60 #include <stdarg.h> 61 #include <string.h> 62 63 #include <stdio.h> 64 65 // nr of buffered acl packets in outgoing queue to get max performance 66 #define NR_BUFFERED_ACL_PACKETS 3 67 68 // used to cache l2cap rejects, echo, and informational requests 69 #define NR_PENDING_SIGNALING_RESPONSES 3 70 71 // nr of credits provided to remote if credits fall below watermark 72 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK 5 73 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT 5 74 75 // offsets for L2CAP SIGNALING COMMANDS 76 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 77 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 78 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 79 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 80 81 // internal table 82 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL 0 83 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL 1 84 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL 2 85 #define L2CAP_FIXED_CHANNEL_TABLE_SIZE (L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL+1) 86 87 #if defined(ENABLE_LE_DATA_CHANNELS) || defined(ENABLE_CLASSIC) 88 #define L2CAP_USES_CHANNELS 89 #endif 90 91 // prototypes 92 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); 93 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ); 94 static void l2cap_notify_channel_can_send(void); 95 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel); 96 #ifdef ENABLE_CLASSIC 97 static void l2cap_finialize_channel_close(l2cap_channel_t *channel); 98 static inline l2cap_service_t * l2cap_get_service(uint16_t psm); 99 static void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status); 100 static void l2cap_emit_channel_closed(l2cap_channel_t *channel); 101 static void l2cap_emit_incoming_connection(l2cap_channel_t *channel); 102 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); 103 #endif 104 #ifdef ENABLE_LE_DATA_CHANNELS 105 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status); 106 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel); 107 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid); 108 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel); 109 static void l2cap_le_finialize_channel_close(l2cap_channel_t *channel); 110 static inline l2cap_service_t * l2cap_le_get_service(uint16_t psm); 111 #endif 112 113 typedef struct l2cap_fixed_channel { 114 btstack_packet_handler_t callback; 115 uint8_t waiting_for_can_send_now; 116 } l2cap_fixed_channel_t; 117 118 #ifdef ENABLE_CLASSIC 119 static btstack_linked_list_t l2cap_channels; 120 static btstack_linked_list_t l2cap_services; 121 static uint8_t require_security_level2_for_outgoing_sdp; 122 #endif 123 124 #ifdef ENABLE_LE_DATA_CHANNELS 125 static btstack_linked_list_t l2cap_le_channels; 126 static btstack_linked_list_t l2cap_le_services; 127 #endif 128 129 // used to cache l2cap rejects, echo, and informational requests 130 static l2cap_signaling_response_t signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; 131 static int signaling_responses_pending; 132 133 static btstack_packet_callback_registration_t hci_event_callback_registration; 134 static l2cap_fixed_channel_t fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_SIZE]; 135 136 #ifdef ENABLE_BLE 137 // only used for connection parameter update events 138 static btstack_packet_handler_t l2cap_event_packet_handler; 139 #endif 140 141 static uint16_t l2cap_fixed_channel_table_channel_id_for_index(int index){ 142 switch (index){ 143 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL: 144 return L2CAP_CID_ATTRIBUTE_PROTOCOL; 145 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL: 146 return L2CAP_CID_SECURITY_MANAGER_PROTOCOL; 147 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL: 148 return L2CAP_CID_CONNECTIONLESS_CHANNEL; 149 default: 150 return 0; 151 } 152 } 153 static int l2cap_fixed_channel_table_index_for_channel_id(uint16_t channel_id){ 154 switch (channel_id){ 155 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 156 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL; 157 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 158 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL; 159 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 160 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL; 161 default: 162 return -1; 163 } 164 } 165 166 static int l2cap_fixed_channel_table_index_is_le(int index){ 167 if (index == L2CAP_CID_CONNECTIONLESS_CHANNEL) return 0; 168 return 1; 169 } 170 171 void l2cap_init(void){ 172 signaling_responses_pending = 0; 173 174 #ifdef ENABLE_CLASSIC 175 l2cap_channels = NULL; 176 l2cap_services = NULL; 177 require_security_level2_for_outgoing_sdp = 0; 178 #endif 179 180 #ifdef ENABLE_LE_DATA_CHANNELS 181 l2cap_le_services = NULL; 182 l2cap_le_channels = NULL; 183 #endif 184 185 #ifdef ENABLE_BLE 186 l2cap_event_packet_handler = NULL; 187 #endif 188 memset(fixed_channels, 0, sizeof(fixed_channels)); 189 190 // 191 // register callback with HCI 192 // 193 hci_event_callback_registration.callback = &l2cap_hci_event_handler; 194 hci_add_event_handler(&hci_event_callback_registration); 195 196 hci_register_acl_packet_handler(&l2cap_acl_handler); 197 198 #ifdef ENABLE_CLASSIC 199 gap_connectable_control(0); // no services yet 200 #endif 201 } 202 203 void l2cap_register_packet_handler(void (*handler)(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 204 #ifdef ENABLE_BLE 205 l2cap_event_packet_handler = handler; 206 #else 207 UNUSED(handler); 208 #endif 209 } 210 211 void l2cap_request_can_send_fix_channel_now_event(hci_con_handle_t con_handle, uint16_t channel_id){ 212 UNUSED(con_handle); 213 214 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 215 if (index < 0) return; 216 fixed_channels[index].waiting_for_can_send_now = 1; 217 l2cap_notify_channel_can_send(); 218 } 219 220 int l2cap_can_send_fixed_channel_packet_now(hci_con_handle_t con_handle, uint16_t channel_id){ 221 UNUSED(channel_id); 222 223 return hci_can_send_acl_packet_now(con_handle); 224 } 225 226 uint8_t *l2cap_get_outgoing_buffer(void){ 227 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 228 } 229 230 int l2cap_reserve_packet_buffer(void){ 231 return hci_reserve_packet_buffer(); 232 } 233 234 void l2cap_release_packet_buffer(void){ 235 hci_release_packet_buffer(); 236 } 237 238 static void l2cap_setup_header(uint8_t * acl_buffer, hci_con_handle_t con_handle, uint8_t packet_boundary, uint16_t remote_cid, uint16_t len){ 239 // 0 - Connection handle : PB=pb : BC=00 240 little_endian_store_16(acl_buffer, 0, con_handle | (packet_boundary << 12) | (0 << 14)); 241 // 2 - ACL length 242 little_endian_store_16(acl_buffer, 2, len + 4); 243 // 4 - L2CAP packet length 244 little_endian_store_16(acl_buffer, 4, len + 0); 245 // 6 - L2CAP channel DEST 246 little_endian_store_16(acl_buffer, 6, remote_cid); 247 } 248 249 // assumption - only on LE connections 250 int l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len){ 251 252 if (!hci_is_packet_buffer_reserved()){ 253 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 254 return BTSTACK_ACL_BUFFERS_FULL; 255 } 256 257 if (!hci_can_send_prepared_acl_packet_now(con_handle)){ 258 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send", con_handle, cid); 259 return BTSTACK_ACL_BUFFERS_FULL; 260 } 261 262 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x", con_handle, cid); 263 264 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 265 l2cap_setup_header(acl_buffer, con_handle, 0, cid, len); 266 // send 267 return hci_send_acl_packet_buffer(len+8); 268 } 269 270 // assumption - only on LE connections 271 int l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len){ 272 273 if (!hci_can_send_acl_packet_now(con_handle)){ 274 log_info("l2cap_send cid 0x%02x, cannot send", cid); 275 return BTSTACK_ACL_BUFFERS_FULL; 276 } 277 278 hci_reserve_packet_buffer(); 279 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 280 281 memcpy(&acl_buffer[8], data, len); 282 283 return l2cap_send_prepared_connectionless(con_handle, cid, len); 284 } 285 286 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel) { 287 log_debug("L2CAP_EVENT_CHANNEL_CAN_SEND_NOW local_cid 0x%x", channel); 288 uint8_t event[4]; 289 event[0] = L2CAP_EVENT_CAN_SEND_NOW; 290 event[1] = sizeof(event) - 2; 291 little_endian_store_16(event, 2, channel); 292 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 293 packet_handler(HCI_EVENT_PACKET, channel, event, sizeof(event)); 294 } 295 296 #ifdef L2CAP_USES_CHANNELS 297 static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 298 (* (channel->packet_handler))(type, channel->local_cid, data, size); 299 } 300 301 static void l2cap_emit_simple_event_with_cid(l2cap_channel_t * channel, uint8_t event_code){ 302 uint8_t event[4]; 303 event[0] = event_code; 304 event[1] = sizeof(event) - 2; 305 little_endian_store_16(event, 2, channel->local_cid); 306 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 307 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 308 } 309 #endif 310 311 #ifdef ENABLE_CLASSIC 312 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 313 log_info("L2CAP_EVENT_CHANNEL_OPENED status 0x%x addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x local_mtu %u, remote_mtu %u, flush_timeout %u", 314 status, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 315 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 316 uint8_t event[24]; 317 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 318 event[1] = sizeof(event) - 2; 319 event[2] = status; 320 reverse_bd_addr(channel->address, &event[3]); 321 little_endian_store_16(event, 9, channel->con_handle); 322 little_endian_store_16(event, 11, channel->psm); 323 little_endian_store_16(event, 13, channel->local_cid); 324 little_endian_store_16(event, 15, channel->remote_cid); 325 little_endian_store_16(event, 17, channel->local_mtu); 326 little_endian_store_16(event, 19, channel->remote_mtu); 327 little_endian_store_16(event, 21, channel->flush_timeout); 328 event[23] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 329 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 330 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 331 } 332 333 static void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 334 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 335 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 336 } 337 338 static void l2cap_emit_incoming_connection(l2cap_channel_t *channel) { 339 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 340 bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid); 341 uint8_t event[16]; 342 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 343 event[1] = sizeof(event) - 2; 344 reverse_bd_addr(channel->address, &event[2]); 345 little_endian_store_16(event, 8, channel->con_handle); 346 little_endian_store_16(event, 10, channel->psm); 347 little_endian_store_16(event, 12, channel->local_cid); 348 little_endian_store_16(event, 14, channel->remote_cid); 349 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 350 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 351 } 352 353 static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 354 btstack_linked_list_iterator_t it; 355 btstack_linked_list_iterator_init(&it, &l2cap_channels); 356 while (btstack_linked_list_iterator_has_next(&it)){ 357 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 358 if ( channel->local_cid == local_cid) { 359 return channel; 360 } 361 } 362 return NULL; 363 } 364 365 /// 366 367 void l2cap_request_can_send_now_event(uint16_t local_cid){ 368 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 369 if (!channel) return; 370 channel->waiting_for_can_send_now = 1; 371 l2cap_notify_channel_can_send(); 372 } 373 374 int l2cap_can_send_packet_now(uint16_t local_cid){ 375 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 376 if (!channel) return 0; 377 return hci_can_send_acl_packet_now(channel->con_handle); 378 } 379 380 int l2cap_can_send_prepared_packet_now(uint16_t local_cid){ 381 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 382 if (!channel) return 0; 383 return hci_can_send_prepared_acl_packet_now(channel->con_handle); 384 } 385 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 386 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 387 if (channel) { 388 return channel->remote_mtu; 389 } 390 return 0; 391 } 392 393 static l2cap_channel_t * l2cap_channel_for_rtx_timer(btstack_timer_source_t * ts){ 394 btstack_linked_list_iterator_t it; 395 btstack_linked_list_iterator_init(&it, &l2cap_channels); 396 while (btstack_linked_list_iterator_has_next(&it)){ 397 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 398 if ( &channel->rtx == ts) { 399 return channel; 400 } 401 } 402 return NULL; 403 } 404 405 static void l2cap_rtx_timeout(btstack_timer_source_t * ts){ 406 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 407 if (!channel) return; 408 409 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 410 411 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 412 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 413 // notify client 414 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 415 416 // discard channel 417 // no need to stop timer here, it is removed from list during timer callback 418 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 419 btstack_memory_l2cap_channel_free(channel); 420 } 421 422 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 423 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 424 btstack_run_loop_remove_timer(&channel->rtx); 425 } 426 427 static void l2cap_start_rtx(l2cap_channel_t * channel){ 428 l2cap_stop_rtx(channel); 429 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 430 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 431 btstack_run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 432 btstack_run_loop_add_timer(&channel->rtx); 433 } 434 435 static void l2cap_start_ertx(l2cap_channel_t * channel){ 436 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 437 l2cap_stop_rtx(channel); 438 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 439 btstack_run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 440 btstack_run_loop_add_timer(&channel->rtx); 441 } 442 443 void l2cap_require_security_level_2_for_outgoing_sdp(void){ 444 require_security_level2_for_outgoing_sdp = 1; 445 } 446 447 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 448 return (psm == BLUETOOTH_PROTOCOL_SDP) && (!require_security_level2_for_outgoing_sdp); 449 } 450 451 static int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 452 if (!hci_can_send_acl_packet_now(handle)){ 453 log_info("l2cap_send_signaling_packet, cannot send"); 454 return BTSTACK_ACL_BUFFERS_FULL; 455 } 456 457 // log_info("l2cap_send_signaling_packet type %u", cmd); 458 hci_reserve_packet_buffer(); 459 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 460 va_list argptr; 461 va_start(argptr, identifier); 462 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 463 va_end(argptr); 464 // log_info("l2cap_send_signaling_packet con %u!", handle); 465 return hci_send_acl_packet_buffer(len); 466 } 467 468 // assumption - only on Classic connections 469 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 470 471 if (!hci_is_packet_buffer_reserved()){ 472 log_error("l2cap_send_prepared called without reserving packet first"); 473 return BTSTACK_ACL_BUFFERS_FULL; 474 } 475 476 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 477 if (!channel) { 478 log_error("l2cap_send_prepared no channel for cid 0x%02x", local_cid); 479 return -1; // TODO: define error 480 } 481 482 if (!hci_can_send_prepared_acl_packet_now(channel->con_handle)){ 483 log_info("l2cap_send_prepared cid 0x%02x, cannot send", local_cid); 484 return BTSTACK_ACL_BUFFERS_FULL; 485 } 486 487 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used", local_cid, channel->con_handle); 488 489 // set non-flushable packet boundary flag if supported on Controller 490 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 491 uint8_t packet_boundary_flag = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 492 l2cap_setup_header(acl_buffer, channel->con_handle, packet_boundary_flag, channel->remote_cid, len); 493 // send 494 return hci_send_acl_packet_buffer(len+8); 495 } 496 497 // assumption - only on Classic connections 498 int l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len){ 499 500 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 501 if (!channel) { 502 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 503 return -1; // TODO: define error 504 } 505 506 if (len > channel->remote_mtu){ 507 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 508 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 509 } 510 511 if (!hci_can_send_acl_packet_now(channel->con_handle)){ 512 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 513 return BTSTACK_ACL_BUFFERS_FULL; 514 } 515 516 hci_reserve_packet_buffer(); 517 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 518 519 memcpy(&acl_buffer[8], data, len); 520 521 return l2cap_send_prepared(local_cid, len); 522 } 523 524 int l2cap_send_echo_request(hci_con_handle_t con_handle, uint8_t *data, uint16_t len){ 525 return l2cap_send_signaling_packet(con_handle, ECHO_REQUEST, 0x77, len, data); 526 } 527 528 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 529 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 530 } 531 532 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 533 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 534 } 535 #endif 536 537 538 #ifdef ENABLE_BLE 539 static int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 540 541 if (!hci_can_send_acl_packet_now(handle)){ 542 log_info("l2cap_send_le_signaling_packet, cannot send"); 543 return BTSTACK_ACL_BUFFERS_FULL; 544 } 545 546 // log_info("l2cap_send_le_signaling_packet type %u", cmd); 547 hci_reserve_packet_buffer(); 548 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 549 va_list argptr; 550 va_start(argptr, identifier); 551 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 552 va_end(argptr); 553 // log_info("l2cap_send_le_signaling_packet con %u!", handle); 554 return hci_send_acl_packet_buffer(len); 555 } 556 #endif 557 558 uint16_t l2cap_max_mtu(void){ 559 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 560 } 561 562 uint16_t l2cap_max_le_mtu(void){ 563 return l2cap_max_mtu(); 564 } 565 566 static uint16_t l2cap_setup_options(l2cap_channel_t * channel, uint8_t * config_options){ 567 int send_retransmission_and_flow_control_option = 0; 568 int options_size; 569 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 570 if (channel->mode == L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION){ 571 send_retransmission_and_flow_control_option = 1; 572 } 573 #endif 574 if (send_retransmission_and_flow_control_option){ 575 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 576 config_options[0] = 0x04; // RETRANSMISSION AND FLOW CONTROL OPTION 577 config_options[1] = 9; // length 578 config_options[2] = (uint8_t) channel->mode; 579 config_options[3] = 1; // TxWindows size 580 config_options[4] = 1; // max retransmit 581 little_endian_store_16( config_options, 5, 100); // Retransmission timeout: 100 ms 582 little_endian_store_16( config_options, 7, 300); // Monitor timeout: 300 ms 583 little_endian_store_16( config_options, 9, channel->local_mtu); // Max PDU size // TODO: use real MTU 584 options_size = 11; 585 #endif 586 } else { 587 config_options[0] = 1; // MTU 588 config_options[1] = 2; // len param 589 little_endian_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 590 options_size = 4; 591 } 592 return options_size; 593 } 594 595 // MARK: L2CAP_RUN 596 // process outstanding signaling tasks 597 static void l2cap_run(void){ 598 599 // log_info("l2cap_run: entered"); 600 601 // check pending signaling responses 602 while (signaling_responses_pending){ 603 604 hci_con_handle_t handle = signaling_responses[0].handle; 605 606 if (!hci_can_send_acl_packet_now(handle)) break; 607 608 uint8_t sig_id = signaling_responses[0].sig_id; 609 uint8_t response_code = signaling_responses[0].code; 610 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 611 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 612 #ifdef ENABLE_CLASSIC 613 uint16_t source_cid = signaling_responses[0].cid; // CONNECTION_REQUEST 614 #endif 615 UNUSED(infoType); 616 617 // remove first item before sending (to avoid sending response mutliple times) 618 signaling_responses_pending--; 619 int i; 620 for (i=0; i < signaling_responses_pending; i++){ 621 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 622 } 623 624 switch (response_code){ 625 #ifdef ENABLE_CLASSIC 626 case CONNECTION_REQUEST: 627 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, source_cid, 0, result, 0); 628 // also disconnect if result is 0x0003 - security blocked 629 if (result == 0x0003){ 630 hci_disconnect_security_block(handle); 631 } 632 break; 633 case ECHO_REQUEST: 634 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 635 break; 636 case INFORMATION_REQUEST: 637 switch (infoType){ 638 case 1: { // Connectionless MTU 639 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 640 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 641 } 642 break; 643 case 2: { // Extended Features Supported 644 // extended features request supported, features: fixed channels, unicast connectionless data reception 645 uint32_t features = 0x280; 646 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 647 features |= 0x0008; 648 #endif 649 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 650 } 651 break; 652 case 3: { // Fixed Channels Supported 653 uint8_t map[8]; 654 memset(map, 0, 8); 655 map[0] = 0x06; // L2CAP Signaling Channel (0x02) + Connectionless reception (0x04) 656 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 657 } 658 break; 659 default: 660 // all other types are not supported 661 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 662 break; 663 } 664 break; 665 case COMMAND_REJECT: 666 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 667 break; 668 #endif 669 #ifdef ENABLE_BLE 670 case LE_CREDIT_BASED_CONNECTION_REQUEST: 671 l2cap_send_le_signaling_packet(handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, sig_id, 0, 0, 0, 0, result); 672 break; 673 case COMMAND_REJECT_LE: 674 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 675 break; 676 #endif 677 default: 678 // should not happen 679 break; 680 } 681 } 682 683 btstack_linked_list_iterator_t it; 684 UNUSED(it); 685 686 #ifdef ENABLE_CLASSIC 687 uint8_t config_options[10]; 688 btstack_linked_list_iterator_init(&it, &l2cap_channels); 689 while (btstack_linked_list_iterator_has_next(&it)){ 690 691 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 692 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 693 switch (channel->state){ 694 695 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 696 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 697 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 698 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 699 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 700 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 701 } 702 break; 703 704 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 705 if (!hci_can_send_command_packet_now()) break; 706 // send connection request - set state first 707 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 708 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 709 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 710 break; 711 712 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 713 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 714 channel->state = L2CAP_STATE_INVALID; 715 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 716 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 717 l2cap_stop_rtx(channel); 718 btstack_linked_list_iterator_remove(&it); 719 btstack_memory_l2cap_channel_free(channel); 720 break; 721 722 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 723 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 724 channel->state = L2CAP_STATE_CONFIG; 725 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 726 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 727 break; 728 729 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 730 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 731 // success, start l2cap handshake 732 channel->local_sig_id = l2cap_next_sig_id(); 733 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 734 l2cap_send_signaling_packet( channel->con_handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 735 l2cap_start_rtx(channel); 736 break; 737 738 case L2CAP_STATE_CONFIG: 739 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 740 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 741 uint16_t flags = 0; 742 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 743 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 744 flags = 1; 745 } else { 746 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 747 } 748 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 749 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 750 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 751 uint16_t options_size = l2cap_setup_options(channel, config_options); 752 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, options_size, &config_options); 753 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 754 } else { 755 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 756 } 757 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 758 } 759 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 760 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 761 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 762 channel->local_sig_id = l2cap_next_sig_id(); 763 uint16_t options_size = l2cap_setup_options(channel, config_options); 764 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, options_size, &config_options); 765 l2cap_start_rtx(channel); 766 } 767 if (l2cap_channel_ready_for_open(channel)){ 768 channel->state = L2CAP_STATE_OPEN; 769 l2cap_emit_channel_opened(channel, 0); // success 770 } 771 break; 772 773 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 774 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 775 channel->state = L2CAP_STATE_INVALID; 776 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 777 // 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 :) 778 l2cap_finialize_channel_close(channel); // -- remove from list 779 break; 780 781 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 782 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 783 channel->local_sig_id = l2cap_next_sig_id(); 784 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 785 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 786 break; 787 default: 788 break; 789 } 790 } 791 #endif 792 793 #ifdef ENABLE_LE_DATA_CHANNELS 794 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 795 while (btstack_linked_list_iterator_has_next(&it)){ 796 uint8_t * acl_buffer; 797 uint8_t * l2cap_payload; 798 uint16_t pos; 799 uint16_t payload_size; 800 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 801 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 802 switch (channel->state){ 803 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 804 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 805 channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; 806 // le psm, source cid, mtu, mps, initial credits 807 channel->local_sig_id = l2cap_next_sig_id(); 808 channel->credits_incoming = channel->new_credits_incoming; 809 channel->new_credits_incoming = 0; 810 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); 811 break; 812 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 813 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 814 // TODO: support larger MPS 815 channel->state = L2CAP_STATE_OPEN; 816 channel->credits_incoming = channel->new_credits_incoming; 817 channel->new_credits_incoming = 0; 818 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); 819 // notify client 820 l2cap_emit_le_channel_opened(channel, 0); 821 break; 822 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 823 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 824 channel->state = L2CAP_STATE_INVALID; 825 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, 0, 0, channel->reason); 826 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 827 l2cap_stop_rtx(channel); 828 btstack_linked_list_iterator_remove(&it); 829 btstack_memory_l2cap_channel_free(channel); 830 break; 831 case L2CAP_STATE_OPEN: 832 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 833 834 // send credits 835 if (channel->new_credits_incoming){ 836 log_info("l2cap: sending %u credits", channel->new_credits_incoming); 837 channel->local_sig_id = l2cap_next_sig_id(); 838 uint16_t new_credits = channel->new_credits_incoming; 839 channel->new_credits_incoming = 0; 840 channel->credits_incoming += new_credits; 841 l2cap_send_le_signaling_packet(channel->con_handle, LE_FLOW_CONTROL_CREDIT, channel->local_sig_id, channel->remote_cid, new_credits); 842 break; 843 } 844 845 // send data 846 if (!channel->send_sdu_buffer) break; 847 if (!channel->credits_outgoing) break; 848 849 // send part of SDU 850 hci_reserve_packet_buffer(); 851 acl_buffer = hci_get_outgoing_packet_buffer(); 852 l2cap_payload = acl_buffer + 8; 853 pos = 0; 854 if (!channel->send_sdu_pos){ 855 // store SDU len 856 channel->send_sdu_pos += 2; 857 little_endian_store_16(l2cap_payload, pos, channel->send_sdu_len); 858 pos += 2; 859 } 860 payload_size = btstack_min(channel->send_sdu_len + 2 - channel->send_sdu_pos, channel->remote_mps - pos); 861 log_info("len %u, pos %u => payload %u, credits %u", channel->send_sdu_len, channel->send_sdu_pos, payload_size, channel->credits_outgoing); 862 memcpy(&l2cap_payload[pos], &channel->send_sdu_buffer[channel->send_sdu_pos-2], payload_size); // -2 for virtual SDU len 863 pos += payload_size; 864 channel->send_sdu_pos += payload_size; 865 l2cap_setup_header(acl_buffer, channel->con_handle, 0, channel->remote_cid, pos); 866 // done 867 868 channel->credits_outgoing--; 869 870 if (channel->send_sdu_pos >= channel->send_sdu_len + 2){ 871 channel->send_sdu_buffer = NULL; 872 // send done event 873 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_PACKET_SENT); 874 // inform about can send now 875 l2cap_le_notify_channel_can_send(channel); 876 } 877 hci_send_acl_packet_buffer(8 + pos); 878 break; 879 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 880 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 881 channel->local_sig_id = l2cap_next_sig_id(); 882 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 883 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 884 break; 885 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 886 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 887 channel->state = L2CAP_STATE_INVALID; 888 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 889 l2cap_le_finialize_channel_close(channel); // -- remove from list 890 break; 891 default: 892 break; 893 } 894 } 895 #endif 896 897 #ifdef ENABLE_BLE 898 // send l2cap con paramter update if necessary 899 hci_connections_get_iterator(&it); 900 while(btstack_linked_list_iterator_has_next(&it)){ 901 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 902 if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; 903 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 904 switch (connection->le_con_parameter_update_state){ 905 case CON_PARAMETER_UPDATE_SEND_REQUEST: 906 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 907 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, connection->le_con_param_update_identifier, 908 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 909 break; 910 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 911 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 912 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 913 break; 914 case CON_PARAMETER_UPDATE_DENY: 915 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 916 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 917 break; 918 default: 919 break; 920 } 921 } 922 #endif 923 924 // log_info("l2cap_run: exit"); 925 } 926 927 #ifdef ENABLE_CLASSIC 928 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 929 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 930 log_info("l2cap_handle_connection_complete expected state"); 931 // success, start l2cap handshake 932 channel->con_handle = con_handle; 933 // check remote SSP feature first 934 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 935 } 936 } 937 938 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 939 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 940 941 // we have been waiting for remote supported features, if both support SSP, 942 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)); 943 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 944 // request security level 2 945 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 946 gap_request_security_level(channel->con_handle, LEVEL_2); 947 return; 948 } 949 // fine, go ahead 950 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 951 } 952 #endif 953 954 #ifdef L2CAP_USES_CHANNELS 955 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 956 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 957 958 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 959 if (!channel) { 960 return NULL; 961 } 962 963 // Init memory (make valgrind happy) 964 memset(channel, 0, sizeof(l2cap_channel_t)); 965 966 // fill in 967 channel->packet_handler = packet_handler; 968 bd_addr_copy(channel->address, address); 969 channel->address_type = address_type; 970 channel->psm = psm; 971 channel->local_mtu = local_mtu; 972 channel->remote_mtu = L2CAP_MINIMAL_MTU; 973 channel->required_security_level = security_level; 974 975 // 976 channel->local_cid = l2cap_next_local_cid(); 977 channel->con_handle = 0; 978 979 // set initial state 980 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 981 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 982 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 983 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 984 return channel; 985 } 986 #endif 987 988 #ifdef ENABLE_CLASSIC 989 990 /** 991 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 992 * @param packet_handler 993 * @param address 994 * @param psm 995 * @param mtu 996 * @param local_cid 997 */ 998 999 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){ 1000 // limit MTU to the size of our outtgoing HCI buffer 1001 uint16_t local_mtu = btstack_min(mtu, l2cap_max_mtu()); 1002 1003 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u -> local mtu %u", bd_addr_to_str(address), psm, mtu, local_mtu); 1004 1005 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 1006 if (!channel) { 1007 return BTSTACK_MEMORY_ALLOC_FAILED; 1008 } 1009 1010 // add to connections list 1011 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1012 1013 // store local_cid 1014 if (out_local_cid){ 1015 *out_local_cid = channel->local_cid; 1016 } 1017 1018 // check if hci connection is already usable 1019 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 1020 if (conn){ 1021 log_info("l2cap_create_channel, hci connection already exists"); 1022 l2cap_handle_connection_complete(conn->con_handle, channel); 1023 // check if remote supported fearures are already received 1024 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 1025 l2cap_handle_remote_supported_features_received(channel); 1026 } 1027 } 1028 1029 l2cap_run(); 1030 1031 return 0; 1032 } 1033 1034 void 1035 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 1036 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 1037 // find channel for local_cid 1038 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1039 if (channel) { 1040 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1041 } 1042 // process 1043 l2cap_run(); 1044 } 1045 1046 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 1047 btstack_linked_list_iterator_t it; 1048 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1049 while (btstack_linked_list_iterator_has_next(&it)){ 1050 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1051 if ( bd_addr_cmp( channel->address, address) != 0) continue; 1052 // channel for this address found 1053 switch (channel->state){ 1054 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 1055 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1056 // failure, forward error code 1057 l2cap_emit_channel_opened(channel, status); 1058 // discard channel 1059 l2cap_stop_rtx(channel); 1060 btstack_linked_list_iterator_remove(&it); 1061 btstack_memory_l2cap_channel_free(channel); 1062 break; 1063 default: 1064 break; 1065 } 1066 } 1067 } 1068 1069 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1070 btstack_linked_list_iterator_t it; 1071 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1072 while (btstack_linked_list_iterator_has_next(&it)){ 1073 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1074 if ( ! bd_addr_cmp( channel->address, address) ){ 1075 l2cap_handle_connection_complete(handle, channel); 1076 } 1077 } 1078 // process 1079 l2cap_run(); 1080 } 1081 #endif 1082 1083 static void l2cap_notify_channel_can_send(void){ 1084 1085 #ifdef ENABLE_CLASSIC 1086 btstack_linked_list_iterator_t it; 1087 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1088 while (btstack_linked_list_iterator_has_next(&it)){ 1089 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1090 if (!channel->waiting_for_can_send_now) continue; 1091 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1092 channel->waiting_for_can_send_now = 0; 1093 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1094 } 1095 #endif 1096 1097 int i; 1098 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1099 if (!fixed_channels[i].callback) continue; 1100 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1101 int can_send = 0; 1102 if (l2cap_fixed_channel_table_index_is_le(i)){ 1103 #ifdef ENABLE_BLE 1104 can_send = hci_can_send_acl_le_packet_now(); 1105 #endif 1106 } else { 1107 #ifdef ENABLE_CLASSIC 1108 can_send = hci_can_send_acl_classic_packet_now(); 1109 #endif 1110 } 1111 if (!can_send) continue; 1112 fixed_channels[i].waiting_for_can_send_now = 0; 1113 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1114 } 1115 } 1116 1117 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1118 1119 UNUSED(packet_type); 1120 UNUSED(cid); 1121 UNUSED(size); 1122 1123 bd_addr_t address; 1124 hci_con_handle_t handle; 1125 int hci_con_used; 1126 btstack_linked_list_iterator_t it; 1127 1128 // avoid unused warnings 1129 UNUSED(address); 1130 UNUSED(hci_con_used); 1131 UNUSED(it); 1132 UNUSED(handle); 1133 1134 switch(hci_event_packet_get_type(packet)){ 1135 1136 // Notify channel packet handler if they can send now 1137 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1138 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1139 l2cap_run(); // try sending signaling packets first 1140 l2cap_notify_channel_can_send(); 1141 break; 1142 1143 case HCI_EVENT_COMMAND_STATUS: 1144 l2cap_run(); // try sending signaling packets first 1145 break; 1146 1147 #ifdef ENABLE_CLASSIC 1148 // handle connection complete events 1149 case HCI_EVENT_CONNECTION_COMPLETE: 1150 reverse_bd_addr(&packet[5], address); 1151 if (packet[2] == 0){ 1152 handle = little_endian_read_16(packet, 3); 1153 l2cap_handle_connection_success_for_addr(address, handle); 1154 } else { 1155 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1156 } 1157 break; 1158 1159 // handle successful create connection cancel command 1160 case HCI_EVENT_COMMAND_COMPLETE: 1161 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1162 if (packet[5] == 0){ 1163 reverse_bd_addr(&packet[6], address); 1164 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1165 l2cap_handle_connection_failed_for_addr(address, 0x16); 1166 } 1167 } 1168 l2cap_run(); // try sending signaling packets first 1169 break; 1170 #endif 1171 1172 // handle disconnection complete events 1173 case HCI_EVENT_DISCONNECTION_COMPLETE: 1174 // send l2cap disconnect events for all channels on this handle and free them 1175 #ifdef ENABLE_CLASSIC 1176 handle = little_endian_read_16(packet, 3); 1177 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1178 while (btstack_linked_list_iterator_has_next(&it)){ 1179 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1180 if (channel->con_handle != handle) continue; 1181 l2cap_emit_channel_closed(channel); 1182 l2cap_stop_rtx(channel); 1183 btstack_linked_list_iterator_remove(&it); 1184 btstack_memory_l2cap_channel_free(channel); 1185 } 1186 #endif 1187 #ifdef ENABLE_LE_DATA_CHANNELS 1188 handle = little_endian_read_16(packet, 3); 1189 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1190 while (btstack_linked_list_iterator_has_next(&it)){ 1191 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1192 if (channel->con_handle != handle) continue; 1193 l2cap_emit_channel_closed(channel); 1194 btstack_linked_list_iterator_remove(&it); 1195 btstack_memory_l2cap_channel_free(channel); 1196 } 1197 #endif 1198 break; 1199 1200 // HCI Connection Timeouts 1201 #ifdef ENABLE_CLASSIC 1202 case L2CAP_EVENT_TIMEOUT_CHECK: 1203 handle = little_endian_read_16(packet, 2); 1204 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1205 if (hci_authentication_active_for_handle(handle)) break; 1206 hci_con_used = 0; 1207 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1208 while (btstack_linked_list_iterator_has_next(&it)){ 1209 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1210 if (channel->con_handle != handle) continue; 1211 hci_con_used = 1; 1212 break; 1213 } 1214 if (hci_con_used) break; 1215 if (!hci_can_send_command_packet_now()) break; 1216 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1217 break; 1218 1219 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1220 handle = little_endian_read_16(packet, 3); 1221 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1222 while (btstack_linked_list_iterator_has_next(&it)){ 1223 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1224 if (channel->con_handle != handle) continue; 1225 l2cap_handle_remote_supported_features_received(channel); 1226 break; 1227 } 1228 break; 1229 1230 case GAP_EVENT_SECURITY_LEVEL: 1231 handle = little_endian_read_16(packet, 2); 1232 log_info("l2cap - security level update"); 1233 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1234 while (btstack_linked_list_iterator_has_next(&it)){ 1235 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1236 if (channel->con_handle != handle) continue; 1237 1238 log_info("l2cap - state %u", channel->state); 1239 1240 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1241 gap_security_level_t required_level = channel->required_security_level; 1242 1243 switch (channel->state){ 1244 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1245 if (actual_level >= required_level){ 1246 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1247 l2cap_emit_incoming_connection(channel); 1248 } else { 1249 channel->reason = 0x0003; // security block 1250 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1251 } 1252 break; 1253 1254 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1255 if (actual_level >= required_level){ 1256 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1257 } else { 1258 // disconnnect, authentication not good enough 1259 hci_disconnect_security_block(handle); 1260 } 1261 break; 1262 1263 default: 1264 break; 1265 } 1266 } 1267 break; 1268 #endif 1269 1270 default: 1271 break; 1272 } 1273 1274 l2cap_run(); 1275 } 1276 1277 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t cid, uint16_t data){ 1278 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1279 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1280 signaling_responses[signaling_responses_pending].handle = handle; 1281 signaling_responses[signaling_responses_pending].code = code; 1282 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1283 signaling_responses[signaling_responses_pending].cid = cid; 1284 signaling_responses[signaling_responses_pending].data = data; 1285 signaling_responses_pending++; 1286 l2cap_run(); 1287 } 1288 } 1289 1290 #ifdef ENABLE_CLASSIC 1291 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1292 channel->remote_sig_id = identifier; 1293 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1294 l2cap_run(); 1295 } 1296 1297 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1298 1299 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1300 l2cap_service_t *service = l2cap_get_service(psm); 1301 if (!service) { 1302 // 0x0002 PSM not supported 1303 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 1304 return; 1305 } 1306 1307 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1308 if (!hci_connection) { 1309 // 1310 log_error("no hci_connection for handle %u", handle); 1311 return; 1312 } 1313 1314 // alloc structure 1315 // log_info("l2cap_handle_connection_request register channel"); 1316 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 1317 psm, service->mtu, service->required_security_level); 1318 if (!channel){ 1319 // 0x0004 No resources available 1320 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 1321 return; 1322 } 1323 1324 channel->con_handle = handle; 1325 channel->remote_cid = source_cid; 1326 channel->remote_sig_id = sig_id; 1327 1328 // limit local mtu to max acl packet length - l2cap header 1329 if (channel->local_mtu > l2cap_max_mtu()) { 1330 channel->local_mtu = l2cap_max_mtu(); 1331 } 1332 1333 // set initial state 1334 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1335 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND | L2CAP_CHANNEL_STATE_VAR_INCOMING); 1336 1337 // add to connections list 1338 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1339 1340 // assert security requirements 1341 gap_request_security_level(handle, channel->required_security_level); 1342 } 1343 1344 void l2cap_accept_connection(uint16_t local_cid){ 1345 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1346 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1347 if (!channel) { 1348 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1349 return; 1350 } 1351 1352 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1353 // configure L2CAP Basic mode 1354 channel->mode = L2CAP_CHANNEL_MODE_BASIC; 1355 #endif 1356 1357 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1358 1359 // process 1360 l2cap_run(); 1361 } 1362 1363 1364 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1365 void l2cap_accept_ertm_connection(uint16_t local_cid){ 1366 log_info("L2CAP_ACCEPT_ERTM_CONNECTION local_cid 0x%x", local_cid); 1367 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1368 if (!channel) { 1369 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1370 return; 1371 } 1372 1373 // configure L2CAP ERTM 1374 channel->mode = L2CAP_CHANNEL_MODE_ENHANCED_RETRANSMISSION; 1375 1376 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1377 1378 // process 1379 l2cap_run(); 1380 } 1381 #endif 1382 1383 1384 void l2cap_decline_connection(uint16_t local_cid){ 1385 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 1386 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1387 if (!channel) { 1388 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1389 return; 1390 } 1391 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1392 channel->reason = 0x04; // no resources available 1393 l2cap_run(); 1394 } 1395 1396 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1397 1398 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1399 1400 uint16_t flags = little_endian_read_16(command, 6); 1401 if (flags & 1) { 1402 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1403 } 1404 1405 // accept the other's configuration options 1406 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1407 uint16_t pos = 8; 1408 while (pos < end_pos){ 1409 uint8_t option_hint = command[pos] >> 7; 1410 uint8_t option_type = command[pos] & 0x7f; 1411 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1412 pos++; 1413 uint8_t length = command[pos++]; 1414 // MTU { type(8): 1, len(8):2, MTU(16) } 1415 if (option_type == 1 && length == 2){ 1416 channel->remote_mtu = little_endian_read_16(command, pos); 1417 if (channel->remote_mtu > l2cap_max_mtu()){ 1418 log_info("Remote MTU %u larger than outgoing buffer, only using MTU = %u", channel->remote_mtu, l2cap_max_mtu()); 1419 channel->remote_mtu = l2cap_max_mtu(); 1420 } 1421 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1422 } 1423 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1424 if (option_type == 2 && length == 2){ 1425 channel->flush_timeout = little_endian_read_16(command, pos); 1426 } 1427 #ifdef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 1428 // Retransmission and Flow Control Option 1429 if (option_type == 4 && length == 9){ 1430 // TODO store and evaluate configuration 1431 // TODO Use different enum name 1432 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1433 } 1434 #endif 1435 // check for unknown options 1436 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1437 log_info("l2cap cid %u, unknown options", channel->local_cid); 1438 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1439 } 1440 pos += length; 1441 } 1442 } 1443 1444 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1445 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1446 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1447 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1448 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 1449 if (channel->state == L2CAP_STATE_OPEN) return 0; 1450 return 1; 1451 } 1452 1453 1454 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1455 1456 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1457 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1458 uint16_t result = 0; 1459 1460 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1461 1462 // handle DISCONNECT REQUESTS seperately 1463 if (code == DISCONNECTION_REQUEST){ 1464 switch (channel->state){ 1465 case L2CAP_STATE_CONFIG: 1466 case L2CAP_STATE_OPEN: 1467 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1468 case L2CAP_STATE_WAIT_DISCONNECT: 1469 l2cap_handle_disconnect_request(channel, identifier); 1470 break; 1471 1472 default: 1473 // ignore in other states 1474 break; 1475 } 1476 return; 1477 } 1478 1479 // @STATEMACHINE(l2cap) 1480 switch (channel->state) { 1481 1482 case L2CAP_STATE_WAIT_CONNECT_RSP: 1483 switch (code){ 1484 case CONNECTION_RESPONSE: 1485 l2cap_stop_rtx(channel); 1486 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1487 switch (result) { 1488 case 0: 1489 // successful connection 1490 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1491 channel->state = L2CAP_STATE_CONFIG; 1492 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1493 break; 1494 case 1: 1495 // connection pending. get some coffee, but start the ERTX 1496 l2cap_start_ertx(channel); 1497 break; 1498 default: 1499 // channel closed 1500 channel->state = L2CAP_STATE_CLOSED; 1501 // map l2cap connection response result to BTstack status enumeration 1502 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1503 1504 // drop link key if security block 1505 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1506 gap_drop_link_key_for_bd_addr(channel->address); 1507 } 1508 1509 // discard channel 1510 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1511 btstack_memory_l2cap_channel_free(channel); 1512 break; 1513 } 1514 break; 1515 1516 default: 1517 //@TODO: implement other signaling packets 1518 break; 1519 } 1520 break; 1521 1522 case L2CAP_STATE_CONFIG: 1523 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1524 switch (code) { 1525 case CONFIGURE_REQUEST: 1526 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1527 l2cap_signaling_handle_configure_request(channel, command); 1528 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1529 // only done if continuation not set 1530 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1531 } 1532 break; 1533 case CONFIGURE_RESPONSE: 1534 l2cap_stop_rtx(channel); 1535 switch (result){ 1536 case 0: // success 1537 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1538 break; 1539 case 4: // pending 1540 l2cap_start_ertx(channel); 1541 break; 1542 default: 1543 // retry on negative result 1544 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1545 break; 1546 } 1547 break; 1548 default: 1549 break; 1550 } 1551 if (l2cap_channel_ready_for_open(channel)){ 1552 // for open: 1553 channel->state = L2CAP_STATE_OPEN; 1554 l2cap_emit_channel_opened(channel, 0); 1555 } 1556 break; 1557 1558 case L2CAP_STATE_WAIT_DISCONNECT: 1559 switch (code) { 1560 case DISCONNECTION_RESPONSE: 1561 l2cap_finialize_channel_close(channel); 1562 break; 1563 default: 1564 //@TODO: implement other signaling packets 1565 break; 1566 } 1567 break; 1568 1569 case L2CAP_STATE_CLOSED: 1570 // @TODO handle incoming requests 1571 break; 1572 1573 case L2CAP_STATE_OPEN: 1574 //@TODO: implement other signaling packets, e.g. re-configure 1575 break; 1576 default: 1577 break; 1578 } 1579 // log_info("new state %u", channel->state); 1580 } 1581 1582 1583 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1584 1585 // get code, signalind identifier and command len 1586 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1587 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1588 1589 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1590 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1591 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 1592 return; 1593 } 1594 1595 // general commands without an assigned channel 1596 switch(code) { 1597 1598 case CONNECTION_REQUEST: { 1599 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1600 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1601 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1602 return; 1603 } 1604 1605 case ECHO_REQUEST: 1606 l2cap_register_signaling_response(handle, code, sig_id, 0, 0); 1607 return; 1608 1609 case INFORMATION_REQUEST: { 1610 uint16_t infoType = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1611 l2cap_register_signaling_response(handle, code, sig_id, 0, infoType); 1612 return; 1613 } 1614 1615 default: 1616 break; 1617 } 1618 1619 1620 // Get potential destination CID 1621 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1622 1623 // Find channel for this sig_id and connection handle 1624 btstack_linked_list_iterator_t it; 1625 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1626 while (btstack_linked_list_iterator_has_next(&it)){ 1627 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1628 if (channel->con_handle != handle) continue; 1629 if (code & 1) { 1630 // match odd commands (responses) by previous signaling identifier 1631 if (channel->local_sig_id == sig_id) { 1632 l2cap_signaling_handler_channel(channel, command); 1633 break; 1634 } 1635 } else { 1636 // match even commands (requests) by local channel id 1637 if (channel->local_cid == dest_cid) { 1638 l2cap_signaling_handler_channel(channel, command); 1639 break; 1640 } 1641 } 1642 } 1643 } 1644 #endif 1645 1646 #ifdef ENABLE_BLE 1647 1648 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 1649 uint8_t event[6]; 1650 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 1651 event[1] = 4; 1652 little_endian_store_16(event, 2, con_handle); 1653 little_endian_store_16(event, 4, result); 1654 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1655 if (!l2cap_event_packet_handler) return; 1656 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 1657 } 1658 1659 // @returns valid 1660 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 1661 hci_connection_t * connection; 1662 uint16_t result; 1663 uint8_t event[10]; 1664 1665 #ifdef ENABLE_LE_DATA_CHANNELS 1666 btstack_linked_list_iterator_t it; 1667 l2cap_channel_t * channel; 1668 uint16_t local_cid; 1669 uint16_t le_psm; 1670 uint16_t new_credits; 1671 uint16_t credits_before; 1672 l2cap_service_t * service; 1673 uint16_t source_cid; 1674 #endif 1675 1676 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1677 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 1678 1679 switch (code){ 1680 1681 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 1682 result = little_endian_read_16(command, 4); 1683 l2cap_emit_connection_parameter_update_response(handle, result); 1684 break; 1685 1686 case CONNECTION_PARAMETER_UPDATE_REQUEST: 1687 connection = hci_connection_for_handle(handle); 1688 if (connection){ 1689 if (connection->role != HCI_ROLE_MASTER){ 1690 // reject command without notifying upper layer when not in master role 1691 return 0; 1692 } 1693 int update_parameter = 1; 1694 le_connection_parameter_range_t existing_range; 1695 gap_get_connection_parameter_range(&existing_range); 1696 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 1697 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 1698 uint16_t le_conn_latency = little_endian_read_16(command,12); 1699 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 1700 1701 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 1702 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 1703 1704 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 1705 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 1706 1707 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 1708 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 1709 1710 if (update_parameter){ 1711 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 1712 connection->le_conn_interval_min = le_conn_interval_min; 1713 connection->le_conn_interval_max = le_conn_interval_max; 1714 connection->le_conn_latency = le_conn_latency; 1715 connection->le_supervision_timeout = le_supervision_timeout; 1716 } else { 1717 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 1718 } 1719 connection->le_con_param_update_identifier = sig_id; 1720 } 1721 1722 if (!l2cap_event_packet_handler) break; 1723 1724 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 1725 event[1] = 8; 1726 memcpy(&event[2], &command[4], 8); 1727 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1728 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1729 break; 1730 1731 #ifdef ENABLE_LE_DATA_CHANNELS 1732 1733 case COMMAND_REJECT: 1734 // Find channel for this sig_id and connection handle 1735 channel = NULL; 1736 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1737 while (btstack_linked_list_iterator_has_next(&it)){ 1738 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1739 if (a_channel->con_handle != handle) continue; 1740 if (a_channel->local_sig_id != sig_id) continue; 1741 channel = a_channel; 1742 break; 1743 } 1744 if (!channel) break; 1745 1746 // if received while waiting for le connection response, assume legacy device 1747 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 1748 channel->state = L2CAP_STATE_CLOSED; 1749 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 1750 l2cap_emit_le_channel_opened(channel, 0x0002); 1751 1752 // discard channel 1753 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1754 btstack_memory_l2cap_channel_free(channel); 1755 break; 1756 } 1757 break; 1758 1759 case LE_CREDIT_BASED_CONNECTION_REQUEST: 1760 1761 // get hci connection, bail if not found (must not happen) 1762 connection = hci_connection_for_handle(handle); 1763 if (!connection) return 0; 1764 1765 // check if service registered 1766 le_psm = little_endian_read_16(command, 4); 1767 service = l2cap_le_get_service(le_psm); 1768 source_cid = little_endian_read_16(command, 6); 1769 1770 if (service){ 1771 if (source_cid < 0x40){ 1772 // 0x0009 Connection refused - Invalid Source CID 1773 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0009); 1774 return 1; 1775 } 1776 1777 // go through list of channels for this ACL connection and check if we get a match 1778 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1779 while (btstack_linked_list_iterator_has_next(&it)){ 1780 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1781 if (a_channel->con_handle != handle) continue; 1782 if (a_channel->remote_cid != source_cid) continue; 1783 // 0x000a Connection refused - Source CID already allocated 1784 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x000a); 1785 return 1; 1786 } 1787 1788 // security: check encryption 1789 if (service->required_security_level >= LEVEL_2){ 1790 if (sm_encryption_key_size(handle) == 0){ 1791 // 0x0008 Connection refused - insufficient encryption 1792 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0008); 1793 return 1; 1794 } 1795 // anything less than 16 byte key size is insufficient 1796 if (sm_encryption_key_size(handle) < 16){ 1797 // 0x0007 Connection refused – insufficient encryption key size 1798 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0007); 1799 return 1; 1800 } 1801 } 1802 1803 // security: check authencation 1804 if (service->required_security_level >= LEVEL_3){ 1805 if (!sm_authenticated(handle)){ 1806 // 0x0005 Connection refused – insufficient authentication 1807 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0005); 1808 return 1; 1809 } 1810 } 1811 1812 // security: check authorization 1813 if (service->required_security_level >= LEVEL_4){ 1814 if (sm_authorization_state(handle) != AUTHORIZATION_GRANTED){ 1815 // 0x0006 Connection refused – insufficient authorization 1816 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0006); 1817 return 1; 1818 } 1819 } 1820 1821 // allocate channel 1822 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 1823 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 1824 if (!channel){ 1825 // 0x0004 Connection refused – no resources available 1826 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0004); 1827 return 1; 1828 } 1829 1830 channel->con_handle = handle; 1831 channel->remote_cid = source_cid; 1832 channel->remote_sig_id = sig_id; 1833 channel->remote_mtu = little_endian_read_16(command, 8); 1834 channel->remote_mps = little_endian_read_16(command, 10); 1835 channel->credits_outgoing = little_endian_read_16(command, 12); 1836 1837 // set initial state 1838 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1839 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_INCOMING; 1840 1841 // add to connections list 1842 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1843 1844 // post connection request event 1845 l2cap_emit_le_incoming_connection(channel); 1846 1847 } else { 1848 // Connection refused – LE_PSM not supported 1849 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, source_cid, 0x0002); 1850 } 1851 break; 1852 1853 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 1854 // Find channel for this sig_id and connection handle 1855 channel = NULL; 1856 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1857 while (btstack_linked_list_iterator_has_next(&it)){ 1858 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1859 if (a_channel->con_handle != handle) continue; 1860 if (a_channel->local_sig_id != sig_id) continue; 1861 channel = a_channel; 1862 break; 1863 } 1864 if (!channel) break; 1865 1866 // cid + 0 1867 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 1868 if (result){ 1869 channel->state = L2CAP_STATE_CLOSED; 1870 // map l2cap connection response result to BTstack status enumeration 1871 l2cap_emit_le_channel_opened(channel, result); 1872 1873 // discard channel 1874 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1875 btstack_memory_l2cap_channel_free(channel); 1876 break; 1877 } 1878 1879 // success 1880 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1881 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1882 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 1883 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 1884 channel->state = L2CAP_STATE_OPEN; 1885 l2cap_emit_le_channel_opened(channel, result); 1886 break; 1887 1888 case LE_FLOW_CONTROL_CREDIT: 1889 // find channel 1890 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1891 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1892 if (!channel) { 1893 log_error("l2cap: no channel for cid 0x%02x", local_cid); 1894 break; 1895 } 1896 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1897 credits_before = channel->credits_outgoing; 1898 channel->credits_outgoing += new_credits; 1899 // check for credit overrun 1900 if (credits_before > channel->credits_outgoing){ 1901 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 1902 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1903 break; 1904 } 1905 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 1906 break; 1907 1908 case DISCONNECTION_REQUEST: 1909 // find channel 1910 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1911 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1912 if (!channel) { 1913 log_error("l2cap: no channel for cid 0x%02x", local_cid); 1914 break; 1915 } 1916 channel->remote_sig_id = sig_id; 1917 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1918 break; 1919 1920 #endif 1921 1922 case DISCONNECTION_RESPONSE: 1923 break; 1924 1925 default: 1926 // command unknown -> reject command 1927 return 0; 1928 } 1929 return 1; 1930 } 1931 #endif 1932 1933 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 1934 UNUSED(packet_type); 1935 UNUSED(channel); 1936 1937 l2cap_channel_t * l2cap_channel; 1938 UNUSED(l2cap_channel); 1939 1940 // Get Channel ID 1941 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1942 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1943 1944 switch (channel_id) { 1945 1946 #ifdef ENABLE_CLASSIC 1947 case L2CAP_CID_SIGNALING: { 1948 uint16_t command_offset = 8; 1949 while (command_offset < size) { 1950 // handle signaling commands 1951 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1952 1953 // increment command_offset 1954 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1955 } 1956 break; 1957 } 1958 #endif 1959 1960 #ifdef ENABLE_BLE 1961 case L2CAP_CID_SIGNALING_LE: { 1962 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1963 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 1964 if (!valid){ 1965 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, 0, L2CAP_REJ_CMD_UNKNOWN); 1966 } 1967 break; 1968 } 1969 #endif 1970 1971 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1972 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 1973 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1974 } 1975 break; 1976 1977 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1978 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 1979 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1980 } 1981 break; 1982 1983 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 1984 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 1985 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1986 } 1987 break; 1988 1989 default: 1990 #ifdef ENABLE_CLASSIC 1991 // Find channel for this channel_id and connection handle 1992 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 1993 if (l2cap_channel) { 1994 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1995 } 1996 #endif 1997 #ifdef ENABLE_LE_DATA_CHANNELS 1998 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 1999 if (l2cap_channel) { 2000 // credit counting 2001 if (l2cap_channel->credits_incoming == 0){ 2002 log_error("LE Data Channel packet received but no incoming credits"); 2003 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2004 break; 2005 } 2006 l2cap_channel->credits_incoming--; 2007 2008 // automatic credits 2009 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 2010 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 2011 } 2012 2013 // first fragment 2014 uint16_t pos = 0; 2015 if (!l2cap_channel->receive_sdu_len){ 2016 l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 2017 l2cap_channel->receive_sdu_pos = 0; 2018 pos += 2; 2019 size -= 2; 2020 } 2021 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); 2022 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 2023 // done? 2024 log_info("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 2025 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 2026 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 2027 l2cap_channel->receive_sdu_len = 0; 2028 } 2029 } else { 2030 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 2031 } 2032 #endif 2033 break; 2034 } 2035 2036 l2cap_run(); 2037 } 2038 2039 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 2040 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 2041 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 2042 if (index < 0) return; 2043 fixed_channels[index].callback = the_packet_handler; 2044 } 2045 2046 #ifdef ENABLE_CLASSIC 2047 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 2048 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 2049 channel->state = L2CAP_STATE_CLOSED; 2050 l2cap_emit_channel_closed(channel); 2051 // discard channel 2052 l2cap_stop_rtx(channel); 2053 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 2054 btstack_memory_l2cap_channel_free(channel); 2055 } 2056 2057 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 2058 btstack_linked_list_iterator_t it; 2059 btstack_linked_list_iterator_init(&it, services); 2060 while (btstack_linked_list_iterator_has_next(&it)){ 2061 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 2062 if ( service->psm == psm){ 2063 return service; 2064 }; 2065 } 2066 return NULL; 2067 } 2068 2069 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 2070 return l2cap_get_service_internal(&l2cap_services, psm); 2071 } 2072 2073 2074 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 2075 2076 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 2077 2078 // check for alread registered psm 2079 l2cap_service_t *service = l2cap_get_service(psm); 2080 if (service) { 2081 log_error("l2cap_register_service: PSM %u already registered", psm); 2082 return L2CAP_SERVICE_ALREADY_REGISTERED; 2083 } 2084 2085 // alloc structure 2086 service = btstack_memory_l2cap_service_get(); 2087 if (!service) { 2088 log_error("l2cap_register_service: no memory for l2cap_service_t"); 2089 return BTSTACK_MEMORY_ALLOC_FAILED; 2090 } 2091 2092 // fill in 2093 service->psm = psm; 2094 service->mtu = mtu; 2095 service->packet_handler = service_packet_handler; 2096 service->required_security_level = security_level; 2097 2098 // add to services list 2099 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 2100 2101 // enable page scan 2102 gap_connectable_control(1); 2103 2104 return 0; 2105 } 2106 2107 uint8_t l2cap_unregister_service(uint16_t psm){ 2108 2109 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 2110 2111 l2cap_service_t *service = l2cap_get_service(psm); 2112 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2113 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 2114 btstack_memory_l2cap_service_free(service); 2115 2116 // disable page scan when no services registered 2117 if (btstack_linked_list_empty(&l2cap_services)) { 2118 gap_connectable_control(0); 2119 } 2120 return 0; 2121 } 2122 #endif 2123 2124 2125 #ifdef ENABLE_LE_DATA_CHANNELS 2126 2127 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel){ 2128 if (!channel->waiting_for_can_send_now) return; 2129 if (channel->send_sdu_buffer) return; 2130 channel->waiting_for_can_send_now = 0; 2131 log_info("L2CAP_EVENT_CHANNEL_LE_CAN_SEND_NOW local_cid 0x%x", channel->local_cid); 2132 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_CAN_SEND_NOW); 2133 } 2134 2135 // 1BH2222 2136 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel) { 2137 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", 2138 channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->remote_mtu); 2139 uint8_t event[19]; 2140 event[0] = L2CAP_EVENT_LE_INCOMING_CONNECTION; 2141 event[1] = sizeof(event) - 2; 2142 event[2] = channel->address_type; 2143 reverse_bd_addr(channel->address, &event[3]); 2144 little_endian_store_16(event, 9, channel->con_handle); 2145 little_endian_store_16(event, 11, channel->psm); 2146 little_endian_store_16(event, 13, channel->local_cid); 2147 little_endian_store_16(event, 15, channel->remote_cid); 2148 little_endian_store_16(event, 17, channel->remote_mtu); 2149 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2150 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2151 } 2152 // 11BH22222 2153 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status) { 2154 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", 2155 status, channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 2156 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu); 2157 uint8_t event[23]; 2158 event[0] = L2CAP_EVENT_LE_CHANNEL_OPENED; 2159 event[1] = sizeof(event) - 2; 2160 event[2] = status; 2161 event[3] = channel->address_type; 2162 reverse_bd_addr(channel->address, &event[4]); 2163 little_endian_store_16(event, 10, channel->con_handle); 2164 event[12] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 2165 little_endian_store_16(event, 13, channel->psm); 2166 little_endian_store_16(event, 15, channel->local_cid); 2167 little_endian_store_16(event, 17, channel->remote_cid); 2168 little_endian_store_16(event, 19, channel->local_mtu); 2169 little_endian_store_16(event, 21, channel->remote_mtu); 2170 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2171 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2172 } 2173 2174 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 2175 btstack_linked_list_iterator_t it; 2176 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2177 while (btstack_linked_list_iterator_has_next(&it)){ 2178 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2179 if ( channel->local_cid == local_cid) { 2180 return channel; 2181 } 2182 } 2183 return NULL; 2184 } 2185 2186 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 2187 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 2188 channel->state = L2CAP_STATE_CLOSED; 2189 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 2190 // discard channel 2191 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2192 btstack_memory_l2cap_channel_free(channel); 2193 } 2194 2195 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 2196 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 2197 } 2198 2199 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 2200 2201 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 2202 2203 // check for alread registered psm 2204 l2cap_service_t *service = l2cap_le_get_service(psm); 2205 if (service) { 2206 return L2CAP_SERVICE_ALREADY_REGISTERED; 2207 } 2208 2209 // alloc structure 2210 service = btstack_memory_l2cap_service_get(); 2211 if (!service) { 2212 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 2213 return BTSTACK_MEMORY_ALLOC_FAILED; 2214 } 2215 2216 // fill in 2217 service->psm = psm; 2218 service->mtu = 0; 2219 service->packet_handler = packet_handler; 2220 service->required_security_level = security_level; 2221 2222 // add to services list 2223 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 2224 2225 // done 2226 return 0; 2227 } 2228 2229 uint8_t l2cap_le_unregister_service(uint16_t psm) { 2230 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 2231 l2cap_service_t *service = l2cap_le_get_service(psm); 2232 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2233 2234 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 2235 btstack_memory_l2cap_service_free(service); 2236 return 0; 2237 } 2238 2239 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 2240 // get channel 2241 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2242 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2243 2244 // validate state 2245 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2246 return ERROR_CODE_COMMAND_DISALLOWED; 2247 } 2248 2249 // set state accept connection 2250 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 2251 channel->receive_sdu_buffer = receive_sdu_buffer; 2252 channel->local_mtu = mtu; 2253 channel->new_credits_incoming = initial_credits; 2254 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2255 2256 // test 2257 // channel->new_credits_incoming = 1; 2258 2259 // go 2260 l2cap_run(); 2261 return 0; 2262 } 2263 2264 /** 2265 * @brief Deny incoming LE Data Channel connection due to resource constraints 2266 * @param local_cid L2CAP LE Data Channel Identifier 2267 */ 2268 2269 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 2270 // get channel 2271 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2272 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2273 2274 // validate state 2275 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2276 return ERROR_CODE_COMMAND_DISALLOWED; 2277 } 2278 2279 // set state decline connection 2280 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 2281 channel->reason = 0x04; // no resources available 2282 l2cap_run(); 2283 return 0; 2284 } 2285 2286 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 2287 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 2288 uint16_t * out_local_cid) { 2289 2290 log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 2291 2292 2293 hci_connection_t * connection = hci_connection_for_handle(con_handle); 2294 if (!connection) { 2295 log_error("no hci_connection for handle 0x%04x", con_handle); 2296 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 2297 } 2298 2299 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, connection->address, connection->address_type, psm, mtu, security_level); 2300 if (!channel) { 2301 return BTSTACK_MEMORY_ALLOC_FAILED; 2302 } 2303 log_info("l2cap_le_create_channel %p", channel); 2304 2305 // store local_cid 2306 if (out_local_cid){ 2307 *out_local_cid = channel->local_cid; 2308 } 2309 2310 // provide buffer 2311 channel->con_handle = con_handle; 2312 channel->receive_sdu_buffer = receive_sdu_buffer; 2313 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 2314 channel->new_credits_incoming = initial_credits; 2315 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2316 2317 // add to connections list 2318 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2319 2320 // go 2321 l2cap_run(); 2322 return 0; 2323 } 2324 2325 /** 2326 * @brief Provide credtis for LE Data Channel 2327 * @param local_cid L2CAP LE Data Channel Identifier 2328 * @param credits Number additional credits for peer 2329 */ 2330 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 2331 2332 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2333 if (!channel) { 2334 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2335 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2336 } 2337 2338 // check state 2339 if (channel->state != L2CAP_STATE_OPEN){ 2340 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 2341 } 2342 2343 // assert incoming credits + credits <= 0xffff 2344 uint32_t total_credits = channel->credits_incoming; 2345 total_credits += channel->new_credits_incoming; 2346 total_credits += credits; 2347 if (total_credits > 0xffff){ 2348 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 2349 channel->new_credits_incoming, credits); 2350 } 2351 2352 // set credits_granted 2353 channel->new_credits_incoming += credits; 2354 2355 // go 2356 l2cap_run(); 2357 return 0; 2358 } 2359 2360 /** 2361 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 2362 * @param local_cid L2CAP LE Data Channel Identifier 2363 */ 2364 int l2cap_le_can_send_now(uint16_t local_cid){ 2365 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2366 if (!channel) { 2367 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2368 return 0; 2369 } 2370 2371 // check state 2372 if (channel->state != L2CAP_STATE_OPEN) return 0; 2373 2374 // check queue 2375 if (channel->send_sdu_buffer) return 0; 2376 2377 // fine, go ahead 2378 return 1; 2379 } 2380 2381 /** 2382 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 2383 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 2384 * so packet handler should be ready to handle it 2385 * @param local_cid L2CAP LE Data Channel Identifier 2386 */ 2387 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 2388 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2389 if (!channel) { 2390 log_error("l2cap_le_request_can_send_now_event no channel for cid 0x%02x", local_cid); 2391 return 0; 2392 } 2393 channel->waiting_for_can_send_now = 1; 2394 l2cap_le_notify_channel_can_send(channel); 2395 return 0; 2396 } 2397 2398 /** 2399 * @brief Send data via LE Data Channel 2400 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 2401 * @param local_cid L2CAP LE Data Channel Identifier 2402 * @param data data to send 2403 * @param size data size 2404 */ 2405 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 2406 2407 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2408 if (!channel) { 2409 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2410 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2411 } 2412 2413 if (len > channel->remote_mtu){ 2414 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 2415 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 2416 } 2417 2418 if (channel->send_sdu_buffer){ 2419 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 2420 return BTSTACK_ACL_BUFFERS_FULL; 2421 } 2422 2423 channel->send_sdu_buffer = data; 2424 channel->send_sdu_len = len; 2425 channel->send_sdu_pos = 0; 2426 2427 l2cap_run(); 2428 return 0; 2429 } 2430 2431 /** 2432 * @brief Disconnect from LE Data Channel 2433 * @param local_cid L2CAP LE Data Channel Identifier 2434 */ 2435 uint8_t l2cap_le_disconnect(uint16_t local_cid) 2436 { 2437 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2438 if (!channel) { 2439 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2440 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2441 } 2442 2443 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2444 l2cap_run(); 2445 return 0; 2446 } 2447 2448 #endif 2449