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