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 /* 39 * l2cap.c 40 * 41 * Logical Link Control and Adaption Protocl (L2CAP) 42 * 43 * Created by Matthias Ringwald on 5/16/09. 44 */ 45 46 #include "l2cap.h" 47 #include "hci.h" 48 #include "hci_dump.h" 49 #include "btstack_debug.h" 50 #include "btstack_event.h" 51 #include "btstack_memory.h" 52 53 #ifdef ENABLE_LE_DATA_CHANNEL 54 #include "ble/sm.h" 55 #endif 56 57 #include <stdarg.h> 58 #include <string.h> 59 60 #include <stdio.h> 61 62 // nr of buffered acl packets in outgoing queue to get max performance 63 #define NR_BUFFERED_ACL_PACKETS 3 64 65 // used to cache l2cap rejects, echo, and informational requests 66 #define NR_PENDING_SIGNALING_RESPONSES 3 67 68 // nr of credits provided to remote if credits fall below watermark 69 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK 5 70 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT 5 71 72 // offsets for L2CAP SIGNALING COMMANDS 73 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 74 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 75 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 76 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 77 78 // internal table 79 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL 0 80 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL 1 81 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL 2 82 #define L2CAP_FIXED_CHANNEL_TABLE_SIZE (L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL+1) 83 84 // prototypes 85 static void l2cap_finialize_channel_close(l2cap_channel_t *channel); 86 static inline l2cap_service_t * l2cap_get_service(uint16_t psm); 87 static void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status); 88 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel); 89 static void l2cap_emit_channel_closed(l2cap_channel_t *channel); 90 static void l2cap_emit_connection_request(l2cap_channel_t *channel); 91 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); 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 #ifdef ENABLE_BLE 96 static void l2cap_le_finialize_channel_close(l2cap_channel_t *channel); 97 static inline l2cap_service_t * l2cap_le_get_service(uint16_t psm); 98 #endif 99 100 typedef struct l2cap_fixed_channel { 101 btstack_packet_handler_t callback; 102 uint8_t waiting_for_can_send_now; 103 } l2cap_fixed_channel_t; 104 105 static btstack_linked_list_t l2cap_channels; 106 static btstack_linked_list_t l2cap_services; 107 static btstack_linked_list_t l2cap_le_channels; 108 static btstack_linked_list_t l2cap_le_services; 109 110 // used to cache l2cap rejects, echo, and informational requests 111 static l2cap_signaling_response_t signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; 112 static int signaling_responses_pending; 113 114 static uint8_t require_security_level2_for_outgoing_sdp; 115 116 static btstack_packet_callback_registration_t hci_event_callback_registration; 117 118 static btstack_packet_handler_t l2cap_event_packet_handler; 119 static l2cap_fixed_channel_t fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_SIZE]; 120 121 static uint16_t l2cap_fixed_channel_table_channel_id_for_index(int index){ 122 switch (index){ 123 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL: 124 return L2CAP_CID_ATTRIBUTE_PROTOCOL; 125 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL: 126 return L2CAP_CID_SECURITY_MANAGER_PROTOCOL; 127 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL: 128 return L2CAP_CID_CONNECTIONLESS_CHANNEL; 129 default: 130 return 0; 131 } 132 } 133 static int l2cap_fixed_channel_table_index_for_channel_id(uint16_t channel_id){ 134 switch (channel_id){ 135 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 136 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL; 137 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 138 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL; 139 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 140 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL; 141 default: 142 return -1; 143 } 144 } 145 146 static int l2cap_fixed_channel_table_index_is_le(int index){ 147 if (index == L2CAP_CID_CONNECTIONLESS_CHANNEL) return 0; 148 return 1; 149 } 150 151 void l2cap_init(void){ 152 signaling_responses_pending = 0; 153 154 l2cap_channels = NULL; 155 l2cap_services = NULL; 156 l2cap_le_services = NULL; 157 l2cap_le_channels = NULL; 158 159 l2cap_event_packet_handler = NULL; 160 memset(fixed_channels, 0, sizeof(fixed_channels)); 161 162 require_security_level2_for_outgoing_sdp = 0; 163 164 // 165 // register callback with HCI 166 // 167 hci_event_callback_registration.callback = &l2cap_hci_event_handler; 168 hci_add_event_handler(&hci_event_callback_registration); 169 170 hci_register_acl_packet_handler(&l2cap_acl_handler); 171 172 gap_connectable_control(0); // no services yet 173 } 174 175 void l2cap_register_packet_handler(void (*handler)(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 176 l2cap_event_packet_handler = handler; 177 } 178 179 static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 180 (* (channel->packet_handler))(type, channel->local_cid, data, size); 181 } 182 183 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 184 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", 185 status, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 186 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 187 uint8_t event[23]; 188 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 189 event[1] = sizeof(event) - 2; 190 event[2] = status; 191 reverse_bd_addr(channel->address, &event[3]); 192 little_endian_store_16(event, 9, channel->con_handle); 193 little_endian_store_16(event, 11, channel->psm); 194 little_endian_store_16(event, 13, channel->local_cid); 195 little_endian_store_16(event, 15, channel->remote_cid); 196 little_endian_store_16(event, 17, channel->local_mtu); 197 little_endian_store_16(event, 19, channel->remote_mtu); 198 little_endian_store_16(event, 21, channel->flush_timeout); 199 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 200 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 201 } 202 203 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 204 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 205 uint8_t event[4]; 206 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 207 event[1] = sizeof(event) - 2; 208 little_endian_store_16(event, 2, channel->local_cid); 209 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 210 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 211 } 212 213 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 214 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 215 bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid); 216 uint8_t event[16]; 217 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 218 event[1] = sizeof(event) - 2; 219 reverse_bd_addr(channel->address, &event[2]); 220 little_endian_store_16(event, 8, channel->con_handle); 221 little_endian_store_16(event, 10, channel->psm); 222 little_endian_store_16(event, 12, channel->local_cid); 223 little_endian_store_16(event, 14, channel->remote_cid); 224 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 225 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 226 } 227 228 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel) { 229 log_info("L2CAP_EVENT_CHANNEL_CAN_SEND_NOW local_cid 0x%x", channel); 230 uint8_t event[4]; 231 event[0] = L2CAP_EVENT_CAN_SEND_NOW; 232 event[1] = sizeof(event) - 2; 233 little_endian_store_16(event, 2, channel); 234 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 235 packet_handler(HCI_EVENT_PACKET, channel, event, sizeof(event)); 236 } 237 238 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 239 uint8_t event[6]; 240 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 241 event[1] = 4; 242 little_endian_store_16(event, 2, con_handle); 243 little_endian_store_16(event, 4, result); 244 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 245 if (!l2cap_event_packet_handler) return; 246 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 247 } 248 249 static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 250 btstack_linked_list_iterator_t it; 251 btstack_linked_list_iterator_init(&it, &l2cap_channels); 252 while (btstack_linked_list_iterator_has_next(&it)){ 253 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 254 if ( channel->local_cid == local_cid) { 255 return channel; 256 } 257 } 258 return NULL; 259 } 260 261 #ifdef ENABLE_BLE 262 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 263 btstack_linked_list_iterator_t it; 264 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 265 while (btstack_linked_list_iterator_has_next(&it)){ 266 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 267 if ( channel->local_cid == local_cid) { 268 return channel; 269 } 270 } 271 return NULL; 272 } 273 #endif 274 275 /// 276 277 void l2cap_request_can_send_now_event(uint16_t local_cid){ 278 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 279 if (!channel) return; 280 channel->waiting_for_can_send_now = 1; 281 l2cap_notify_channel_can_send(); 282 } 283 284 void l2cap_request_can_send_fix_channel_now_event(hci_con_handle_t con_handle, uint16_t channel_id){ 285 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 286 if (index < 0) return; 287 fixed_channels[index].waiting_for_can_send_now = 1; 288 l2cap_notify_channel_can_send(); 289 } 290 291 /// 292 293 int l2cap_can_send_packet_now(uint16_t local_cid){ 294 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 295 if (!channel) return 0; 296 return hci_can_send_acl_packet_now(channel->con_handle); 297 } 298 299 int l2cap_can_send_prepared_packet_now(uint16_t local_cid){ 300 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 301 if (!channel) return 0; 302 return hci_can_send_prepared_acl_packet_now(channel->con_handle); 303 } 304 305 int l2cap_can_send_fixed_channel_packet_now(hci_con_handle_t con_handle, uint16_t channel_id){ 306 return hci_can_send_acl_packet_now(con_handle); 307 } 308 309 /// 310 311 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 312 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 313 if (channel) { 314 return channel->remote_mtu; 315 } 316 return 0; 317 } 318 319 static l2cap_channel_t * l2cap_channel_for_rtx_timer(btstack_timer_source_t * ts){ 320 btstack_linked_list_iterator_t it; 321 btstack_linked_list_iterator_init(&it, &l2cap_channels); 322 while (btstack_linked_list_iterator_has_next(&it)){ 323 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 324 if ( &channel->rtx == ts) { 325 return channel; 326 } 327 } 328 return NULL; 329 } 330 331 static void l2cap_rtx_timeout(btstack_timer_source_t * ts){ 332 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 333 if (!channel) return; 334 335 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 336 337 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 338 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 339 // notify client 340 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 341 342 // discard channel 343 // no need to stop timer here, it is removed from list during timer callback 344 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 345 btstack_memory_l2cap_channel_free(channel); 346 } 347 348 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 349 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 350 btstack_run_loop_remove_timer(&channel->rtx); 351 } 352 353 static void l2cap_start_rtx(l2cap_channel_t * channel){ 354 l2cap_stop_rtx(channel); 355 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 356 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 357 btstack_run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 358 btstack_run_loop_add_timer(&channel->rtx); 359 } 360 361 static void l2cap_start_ertx(l2cap_channel_t * channel){ 362 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 363 l2cap_stop_rtx(channel); 364 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 365 btstack_run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 366 btstack_run_loop_add_timer(&channel->rtx); 367 } 368 369 void l2cap_require_security_level_2_for_outgoing_sdp(void){ 370 require_security_level2_for_outgoing_sdp = 1; 371 } 372 373 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 374 return (psm == PSM_SDP) && (!require_security_level2_for_outgoing_sdp); 375 } 376 377 static int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 378 379 if (!hci_can_send_acl_packet_now(handle)){ 380 log_info("l2cap_send_signaling_packet, cannot send"); 381 return BTSTACK_ACL_BUFFERS_FULL; 382 } 383 384 // log_info("l2cap_send_signaling_packet type %u", cmd); 385 hci_reserve_packet_buffer(); 386 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 387 va_list argptr; 388 va_start(argptr, identifier); 389 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 390 va_end(argptr); 391 // log_info("l2cap_send_signaling_packet con %u!", handle); 392 return hci_send_acl_packet_buffer(len); 393 } 394 395 #ifdef ENABLE_BLE 396 static int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 397 398 if (!hci_can_send_acl_packet_now(handle)){ 399 log_info("l2cap_send_signaling_packet, cannot send"); 400 return BTSTACK_ACL_BUFFERS_FULL; 401 } 402 403 // log_info("l2cap_send_signaling_packet type %u", cmd); 404 hci_reserve_packet_buffer(); 405 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 406 va_list argptr; 407 va_start(argptr, identifier); 408 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 409 va_end(argptr); 410 // log_info("l2cap_send_signaling_packet con %u!", handle); 411 return hci_send_acl_packet_buffer(len); 412 } 413 #endif 414 415 uint8_t *l2cap_get_outgoing_buffer(void){ 416 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 417 } 418 419 int l2cap_reserve_packet_buffer(void){ 420 return hci_reserve_packet_buffer(); 421 } 422 423 void l2cap_release_packet_buffer(void){ 424 hci_release_packet_buffer(); 425 } 426 427 static void l2cap_setup_header(uint8_t * acl_buffer, hci_con_handle_t con_handle, uint16_t remote_cid, uint16_t len){ 428 429 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 430 431 // 0 - Connection handle : PB=pb : BC=00 432 little_endian_store_16(acl_buffer, 0, con_handle | (pb << 12) | (0 << 14)); 433 // 2 - ACL length 434 little_endian_store_16(acl_buffer, 2, len + 4); 435 // 4 - L2CAP packet length 436 little_endian_store_16(acl_buffer, 4, len + 0); 437 // 6 - L2CAP channel DEST 438 little_endian_store_16(acl_buffer, 6, remote_cid); 439 } 440 441 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 442 443 if (!hci_is_packet_buffer_reserved()){ 444 log_error("l2cap_send_prepared called without reserving packet first"); 445 return BTSTACK_ACL_BUFFERS_FULL; 446 } 447 448 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 449 if (!channel) { 450 log_error("l2cap_send_prepared no channel for cid 0x%02x", local_cid); 451 return -1; // TODO: define error 452 } 453 454 if (!hci_can_send_prepared_acl_packet_now(channel->con_handle)){ 455 log_info("l2cap_send_prepared cid 0x%02x, cannot send", local_cid); 456 return BTSTACK_ACL_BUFFERS_FULL; 457 } 458 459 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used", local_cid, channel->con_handle); 460 461 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 462 l2cap_setup_header(acl_buffer, channel->con_handle, channel->remote_cid, len); 463 // send 464 return hci_send_acl_packet_buffer(len+8); 465 } 466 467 int l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len){ 468 469 if (!hci_is_packet_buffer_reserved()){ 470 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 471 return BTSTACK_ACL_BUFFERS_FULL; 472 } 473 474 if (!hci_can_send_prepared_acl_packet_now(con_handle)){ 475 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send", con_handle, cid); 476 return BTSTACK_ACL_BUFFERS_FULL; 477 } 478 479 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x", con_handle, cid); 480 481 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 482 l2cap_setup_header(acl_buffer, con_handle, cid, len); 483 // send 484 return hci_send_acl_packet_buffer(len+8); 485 } 486 487 int l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len){ 488 489 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 490 if (!channel) { 491 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 492 return -1; // TODO: define error 493 } 494 495 if (len > channel->remote_mtu){ 496 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 497 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 498 } 499 500 if (!hci_can_send_acl_packet_now(channel->con_handle)){ 501 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 502 return BTSTACK_ACL_BUFFERS_FULL; 503 } 504 505 hci_reserve_packet_buffer(); 506 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 507 508 memcpy(&acl_buffer[8], data, len); 509 510 return l2cap_send_prepared(local_cid, len); 511 } 512 513 int l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len){ 514 515 if (!hci_can_send_acl_packet_now(con_handle)){ 516 log_info("l2cap_send cid 0x%02x, cannot send", cid); 517 return BTSTACK_ACL_BUFFERS_FULL; 518 } 519 520 hci_reserve_packet_buffer(); 521 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 522 523 memcpy(&acl_buffer[8], data, len); 524 525 return l2cap_send_prepared_connectionless(con_handle, cid, len); 526 } 527 528 int l2cap_send_echo_request(hci_con_handle_t con_handle, uint8_t *data, uint16_t len){ 529 return l2cap_send_signaling_packet(con_handle, ECHO_REQUEST, 0x77, len, data); 530 } 531 532 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 533 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 534 } 535 536 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 537 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 538 } 539 540 541 542 // MARK: L2CAP_RUN 543 // process outstanding signaling tasks 544 static void l2cap_run(void){ 545 546 // log_info("l2cap_run: entered"); 547 548 // check pending signaling responses 549 while (signaling_responses_pending){ 550 551 hci_con_handle_t handle = signaling_responses[0].handle; 552 553 if (!hci_can_send_acl_packet_now(handle)) break; 554 555 uint8_t sig_id = signaling_responses[0].sig_id; 556 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 557 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 558 uint8_t response_code = signaling_responses[0].code; 559 560 // remove first item before sending (to avoid sending response mutliple times) 561 signaling_responses_pending--; 562 int i; 563 for (i=0; i < signaling_responses_pending; i++){ 564 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 565 } 566 567 switch (response_code){ 568 case CONNECTION_REQUEST: 569 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 570 // also disconnect if result is 0x0003 - security blocked 571 if (result == 0x0003){ 572 hci_disconnect_security_block(handle); 573 } 574 break; 575 case ECHO_REQUEST: 576 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 577 break; 578 case INFORMATION_REQUEST: 579 switch (infoType){ 580 case 1: { // Connectionless MTU 581 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 582 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 583 break; 584 } 585 case 2: { // Extended Features Supported 586 // extended features request supported, features: fixed channels, unicast connectionless data reception 587 uint32_t features = 0x280; 588 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 589 break; 590 } 591 case 3: { // Fixed Channels Supported 592 uint8_t map[8]; 593 memset(map, 0, 8); 594 map[0] = 0x06; // L2CAP Signaling Channel (0x02) + Connectionless reception (0x04) 595 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 596 break; 597 } 598 default: 599 // all other types are not supported 600 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 601 break; 602 } 603 break; 604 case COMMAND_REJECT: 605 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 606 break; 607 #ifdef ENABLE_BLE 608 case LE_CREDIT_BASED_CONNECTION_REQUEST: 609 l2cap_send_le_signaling_packet(handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, sig_id, 0, 0, 0, 0, result); 610 break; 611 case COMMAND_REJECT_LE: 612 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 613 break; 614 #endif 615 default: 616 // should not happen 617 break; 618 } 619 } 620 621 uint8_t config_options[4]; 622 btstack_linked_list_iterator_t it; 623 btstack_linked_list_iterator_init(&it, &l2cap_channels); 624 while (btstack_linked_list_iterator_has_next(&it)){ 625 626 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 627 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 628 switch (channel->state){ 629 630 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 631 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 632 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 633 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 634 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 635 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 636 } 637 break; 638 639 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 640 if (!hci_can_send_command_packet_now()) break; 641 // send connection request - set state first 642 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 643 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 644 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 645 break; 646 647 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 648 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 649 channel->state = L2CAP_STATE_INVALID; 650 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 651 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 652 l2cap_stop_rtx(channel); 653 btstack_linked_list_iterator_remove(&it); 654 btstack_memory_l2cap_channel_free(channel); 655 break; 656 657 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 658 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 659 channel->state = L2CAP_STATE_CONFIG; 660 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 661 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 662 break; 663 664 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 665 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 666 // success, start l2cap handshake 667 channel->local_sig_id = l2cap_next_sig_id(); 668 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 669 l2cap_send_signaling_packet( channel->con_handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 670 l2cap_start_rtx(channel); 671 break; 672 673 case L2CAP_STATE_CONFIG: 674 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 675 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 676 uint16_t flags = 0; 677 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 678 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 679 flags = 1; 680 } else { 681 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 682 } 683 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 684 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 685 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 686 config_options[0] = 1; // MTU 687 config_options[1] = 2; // len param 688 little_endian_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 689 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 690 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 691 } else { 692 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 693 } 694 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 695 } 696 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 697 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 698 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 699 channel->local_sig_id = l2cap_next_sig_id(); 700 config_options[0] = 1; // MTU 701 config_options[1] = 2; // len param 702 little_endian_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 703 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 704 l2cap_start_rtx(channel); 705 } 706 if (l2cap_channel_ready_for_open(channel)){ 707 channel->state = L2CAP_STATE_OPEN; 708 l2cap_emit_channel_opened(channel, 0); // success 709 } 710 break; 711 712 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 713 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 714 channel->state = L2CAP_STATE_INVALID; 715 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 716 // 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 :) 717 l2cap_finialize_channel_close(channel); // -- remove from list 718 break; 719 720 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 721 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 722 channel->local_sig_id = l2cap_next_sig_id(); 723 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 724 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 725 break; 726 default: 727 break; 728 } 729 } 730 731 #ifdef ENABLE_BLE 732 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 733 while (btstack_linked_list_iterator_has_next(&it)){ 734 uint8_t * acl_buffer; 735 uint8_t * l2cap_payload; 736 uint16_t pos; 737 uint16_t payload_size; 738 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 739 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 740 switch (channel->state){ 741 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 742 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 743 channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; 744 // le psm, source cid, mtu, mps, initial credits 745 channel->local_sig_id = l2cap_next_sig_id(); 746 channel->credits_incoming = channel->new_credits_incoming; 747 channel->new_credits_incoming = 0; 748 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); 749 break; 750 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 751 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 752 // TODO: support larger MPS 753 channel->state = L2CAP_STATE_OPEN; 754 channel->credits_incoming = channel->new_credits_incoming; 755 channel->new_credits_incoming = 0; 756 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); 757 // notify client 758 l2cap_emit_channel_opened(channel, 0); 759 break; 760 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 761 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 762 channel->state = L2CAP_STATE_INVALID; 763 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, 0, 0, channel->reason); 764 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 765 l2cap_stop_rtx(channel); 766 btstack_linked_list_iterator_remove(&it); 767 btstack_memory_l2cap_channel_free(channel); 768 break; 769 case L2CAP_STATE_OPEN: 770 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 771 772 // send credits 773 if (channel->new_credits_incoming){ 774 log_info("l2cap: sending %u credits", channel->new_credits_incoming); 775 channel->local_sig_id = l2cap_next_sig_id(); 776 uint16_t new_credits = channel->new_credits_incoming; 777 channel->new_credits_incoming = 0; 778 channel->credits_incoming += new_credits; 779 l2cap_send_le_signaling_packet(channel->con_handle, LE_FLOW_CONTROL_CREDIT, channel->local_sig_id, channel->remote_cid, new_credits); 780 break; 781 } 782 783 // send data 784 if (!channel->send_sdu_buffer) break; 785 if (!channel->credits_outgoing) break; 786 787 // send part of SDU 788 hci_reserve_packet_buffer(); 789 acl_buffer = hci_get_outgoing_packet_buffer(); 790 l2cap_payload = acl_buffer + 8; 791 pos = 0; 792 if (!channel->send_sdu_pos){ 793 // store SDU len 794 channel->send_sdu_pos += 2; 795 little_endian_store_16(l2cap_payload, pos, channel->send_sdu_len); 796 pos += 2; 797 } 798 payload_size = btstack_min(channel->send_sdu_len + 2 - channel->send_sdu_pos, channel->remote_mps - pos); 799 log_info("len %u, pos %u => payload %u, credits %u", channel->send_sdu_len, channel->send_sdu_pos, payload_size, channel->credits_outgoing); 800 memcpy(&l2cap_payload[pos], &channel->send_sdu_buffer[channel->send_sdu_pos-2], payload_size); // -2 for virtual SDU len 801 pos += payload_size; 802 channel->send_sdu_pos += payload_size; 803 l2cap_setup_header(acl_buffer, channel->con_handle, channel->remote_cid, pos); 804 // done 805 806 channel->credits_outgoing--; 807 808 if (channel->send_sdu_pos >= channel->send_sdu_len + 2){ 809 channel->send_sdu_buffer = NULL; 810 // TODO: send done event 811 } 812 hci_send_acl_packet_buffer(8 + pos); 813 break; 814 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 815 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 816 channel->local_sig_id = l2cap_next_sig_id(); 817 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 818 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 819 break; 820 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 821 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 822 channel->state = L2CAP_STATE_INVALID; 823 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 824 l2cap_le_finialize_channel_close(channel); // -- remove from list 825 break; 826 default: 827 break; 828 } 829 } 830 831 // send l2cap con paramter update if necessary 832 hci_connections_get_iterator(&it); 833 while(btstack_linked_list_iterator_has_next(&it)){ 834 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 835 if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; 836 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 837 switch (connection->le_con_parameter_update_state){ 838 case CON_PARAMETER_UPDATE_SEND_REQUEST: 839 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 840 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, connection->le_con_param_update_identifier, 841 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 842 break; 843 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 844 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 845 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 846 break; 847 case CON_PARAMETER_UPDATE_DENY: 848 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 849 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 850 break; 851 default: 852 break; 853 } 854 } 855 #endif 856 857 // log_info("l2cap_run: exit"); 858 } 859 860 uint16_t l2cap_max_mtu(void){ 861 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 862 } 863 864 uint16_t l2cap_max_le_mtu(void){ 865 return l2cap_max_mtu(); 866 } 867 868 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 869 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 870 log_info("l2cap_handle_connection_complete expected state"); 871 // success, start l2cap handshake 872 channel->con_handle = con_handle; 873 // check remote SSP feature first 874 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 875 } 876 } 877 878 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 879 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 880 881 // we have been waiting for remote supported features, if both support SSP, 882 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)); 883 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 884 // request security level 2 885 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 886 gap_request_security_level(channel->con_handle, LEVEL_2); 887 return; 888 } 889 // fine, go ahead 890 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 891 } 892 893 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 894 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 895 896 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 897 if (!channel) { 898 return NULL; 899 } 900 901 // Init memory (make valgrind happy) 902 memset(channel, 0, sizeof(l2cap_channel_t)); 903 904 // fill in 905 channel->packet_handler = packet_handler; 906 bd_addr_copy(channel->address, address); 907 channel->address_type = address_type; 908 channel->psm = psm; 909 channel->local_mtu = local_mtu; 910 channel->remote_mtu = L2CAP_MINIMAL_MTU; 911 channel->required_security_level = security_level; 912 913 // 914 channel->local_cid = l2cap_next_local_cid(); 915 channel->con_handle = 0; 916 917 // set initial state 918 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 919 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 920 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 921 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 922 return channel; 923 } 924 925 /** 926 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 927 * @param packet_handler 928 * @param address 929 * @param psm 930 * @param mtu 931 * @param local_cid 932 */ 933 934 uint8_t l2cap_create_channel(btstack_packet_handler_t channel_packet_handler, bd_addr_t address, uint16_t psm, uint16_t local_mtu, uint16_t * out_local_cid){ 935 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, local_mtu); 936 937 if (local_mtu > l2cap_max_mtu()) { 938 local_mtu = l2cap_max_mtu(); 939 } 940 941 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 942 if (!channel) { 943 return BTSTACK_MEMORY_ALLOC_FAILED; 944 } 945 946 // add to connections list 947 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 948 949 // store local_cid 950 if (out_local_cid){ 951 *out_local_cid = channel->local_cid; 952 } 953 954 // check if hci connection is already usable 955 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 956 if (conn){ 957 log_info("l2cap_create_channel, hci connection already exists"); 958 l2cap_handle_connection_complete(conn->con_handle, channel); 959 // check if remote supported fearures are already received 960 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 961 l2cap_handle_remote_supported_features_received(channel); 962 } 963 } 964 965 l2cap_run(); 966 967 return 0; 968 } 969 970 void 971 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 972 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 973 // find channel for local_cid 974 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 975 if (channel) { 976 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 977 } 978 // process 979 l2cap_run(); 980 } 981 982 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 983 btstack_linked_list_iterator_t it; 984 btstack_linked_list_iterator_init(&it, &l2cap_channels); 985 while (btstack_linked_list_iterator_has_next(&it)){ 986 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 987 if ( bd_addr_cmp( channel->address, address) != 0) continue; 988 // channel for this address found 989 switch (channel->state){ 990 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 991 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 992 // failure, forward error code 993 l2cap_emit_channel_opened(channel, status); 994 // discard channel 995 l2cap_stop_rtx(channel); 996 btstack_linked_list_iterator_remove(&it); 997 btstack_memory_l2cap_channel_free(channel); 998 break; 999 default: 1000 break; 1001 } 1002 } 1003 } 1004 1005 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1006 btstack_linked_list_iterator_t it; 1007 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1008 while (btstack_linked_list_iterator_has_next(&it)){ 1009 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1010 if ( ! bd_addr_cmp( channel->address, address) ){ 1011 l2cap_handle_connection_complete(handle, channel); 1012 } 1013 } 1014 // process 1015 l2cap_run(); 1016 } 1017 1018 static void l2cap_notify_channel_can_send(void){ 1019 btstack_linked_list_iterator_t it; 1020 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1021 while (btstack_linked_list_iterator_has_next(&it)){ 1022 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1023 if (!channel->waiting_for_can_send_now) continue; 1024 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1025 channel->waiting_for_can_send_now = 0; 1026 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1027 } 1028 1029 int i; 1030 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1031 if (!fixed_channels[i].callback) continue; 1032 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1033 int can_send; 1034 if (l2cap_fixed_channel_table_index_is_le(i)){ 1035 can_send = hci_can_send_acl_le_packet_now(); 1036 } else { 1037 can_send = hci_can_send_acl_classic_packet_now(); 1038 } 1039 if (!can_send) continue; 1040 fixed_channels[i].waiting_for_can_send_now = 0; 1041 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1042 } 1043 } 1044 1045 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1046 1047 bd_addr_t address; 1048 hci_con_handle_t handle; 1049 btstack_linked_list_iterator_t it; 1050 int hci_con_used; 1051 1052 switch(hci_event_packet_get_type(packet)){ 1053 1054 // handle connection complete events 1055 case HCI_EVENT_CONNECTION_COMPLETE: 1056 reverse_bd_addr(&packet[5], address); 1057 if (packet[2] == 0){ 1058 handle = little_endian_read_16(packet, 3); 1059 l2cap_handle_connection_success_for_addr(address, handle); 1060 } else { 1061 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1062 } 1063 break; 1064 1065 // handle successful create connection cancel command 1066 case HCI_EVENT_COMMAND_COMPLETE: 1067 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1068 if (packet[5] == 0){ 1069 reverse_bd_addr(&packet[6], address); 1070 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1071 l2cap_handle_connection_failed_for_addr(address, 0x16); 1072 } 1073 } 1074 l2cap_run(); // try sending signaling packets first 1075 break; 1076 1077 case HCI_EVENT_COMMAND_STATUS: 1078 l2cap_run(); // try sending signaling packets first 1079 break; 1080 1081 // handle disconnection complete events 1082 case HCI_EVENT_DISCONNECTION_COMPLETE: 1083 // send l2cap disconnect events for all channels on this handle and free them 1084 handle = little_endian_read_16(packet, 3); 1085 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1086 while (btstack_linked_list_iterator_has_next(&it)){ 1087 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1088 if (channel->con_handle != handle) continue; 1089 l2cap_emit_channel_closed(channel); 1090 l2cap_stop_rtx(channel); 1091 btstack_linked_list_iterator_remove(&it); 1092 btstack_memory_l2cap_channel_free(channel); 1093 } 1094 #ifdef ENABLE_BLE 1095 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1096 while (btstack_linked_list_iterator_has_next(&it)){ 1097 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1098 if (channel->con_handle != handle) continue; 1099 l2cap_emit_channel_closed(channel); 1100 btstack_linked_list_iterator_remove(&it); 1101 btstack_memory_l2cap_channel_free(channel); 1102 } 1103 #endif 1104 break; 1105 1106 // Notify channel packet handler if they can send now 1107 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1108 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1109 l2cap_run(); // try sending signaling packets first 1110 l2cap_notify_channel_can_send(); 1111 break; 1112 1113 // HCI Connection Timeouts 1114 case L2CAP_EVENT_TIMEOUT_CHECK: 1115 handle = little_endian_read_16(packet, 2); 1116 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1117 if (hci_authentication_active_for_handle(handle)) break; 1118 hci_con_used = 0; 1119 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1120 while (btstack_linked_list_iterator_has_next(&it)){ 1121 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1122 if (channel->con_handle != handle) continue; 1123 hci_con_used = 1; 1124 break; 1125 } 1126 if (hci_con_used) break; 1127 if (!hci_can_send_command_packet_now()) break; 1128 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1129 break; 1130 1131 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1132 handle = little_endian_read_16(packet, 3); 1133 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1134 while (btstack_linked_list_iterator_has_next(&it)){ 1135 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1136 if (channel->con_handle != handle) continue; 1137 l2cap_handle_remote_supported_features_received(channel); 1138 break; 1139 } 1140 break; 1141 1142 case GAP_EVENT_SECURITY_LEVEL: 1143 handle = little_endian_read_16(packet, 2); 1144 log_info("l2cap - security level update"); 1145 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1146 while (btstack_linked_list_iterator_has_next(&it)){ 1147 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1148 if (channel->con_handle != handle) continue; 1149 1150 log_info("l2cap - state %u", channel->state); 1151 1152 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1153 gap_security_level_t required_level = channel->required_security_level; 1154 1155 switch (channel->state){ 1156 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1157 if (actual_level >= required_level){ 1158 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1159 l2cap_emit_connection_request(channel); 1160 } else { 1161 channel->reason = 0x0003; // security block 1162 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1163 } 1164 break; 1165 1166 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1167 if (actual_level >= required_level){ 1168 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1169 } else { 1170 // disconnnect, authentication not good enough 1171 hci_disconnect_security_block(handle); 1172 } 1173 break; 1174 1175 default: 1176 break; 1177 } 1178 } 1179 break; 1180 1181 default: 1182 break; 1183 } 1184 1185 l2cap_run(); 1186 } 1187 1188 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1189 channel->remote_sig_id = identifier; 1190 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1191 l2cap_run(); 1192 } 1193 1194 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 1195 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1196 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1197 signaling_responses[signaling_responses_pending].handle = handle; 1198 signaling_responses[signaling_responses_pending].code = code; 1199 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1200 signaling_responses[signaling_responses_pending].data = data; 1201 signaling_responses_pending++; 1202 l2cap_run(); 1203 } 1204 } 1205 1206 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1207 1208 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1209 l2cap_service_t *service = l2cap_get_service(psm); 1210 if (!service) { 1211 // 0x0002 PSM not supported 1212 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 1213 return; 1214 } 1215 1216 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1217 if (!hci_connection) { 1218 // 1219 log_error("no hci_connection for handle %u", handle); 1220 return; 1221 } 1222 1223 // alloc structure 1224 // log_info("l2cap_handle_connection_request register channel"); 1225 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 1226 psm, service->mtu, service->required_security_level); 1227 if (!channel){ 1228 // 0x0004 No resources available 1229 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 1230 return; 1231 } 1232 1233 channel->con_handle = handle; 1234 channel->remote_cid = source_cid; 1235 channel->remote_sig_id = sig_id; 1236 1237 // limit local mtu to max acl packet length - l2cap header 1238 if (channel->local_mtu > l2cap_max_mtu()) { 1239 channel->local_mtu = l2cap_max_mtu(); 1240 } 1241 1242 // set initial state 1243 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1244 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 1245 1246 // add to connections list 1247 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1248 1249 // assert security requirements 1250 gap_request_security_level(handle, channel->required_security_level); 1251 } 1252 1253 void l2cap_accept_connection(uint16_t local_cid){ 1254 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1255 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1256 if (!channel) { 1257 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1258 return; 1259 } 1260 1261 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1262 1263 // process 1264 l2cap_run(); 1265 } 1266 1267 void l2cap_decline_connection(uint16_t local_cid){ 1268 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 1269 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1270 if (!channel) { 1271 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1272 return; 1273 } 1274 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1275 channel->reason = 0x04; // no resources available 1276 l2cap_run(); 1277 } 1278 1279 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1280 1281 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1282 1283 uint16_t flags = little_endian_read_16(command, 6); 1284 if (flags & 1) { 1285 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1286 } 1287 1288 // accept the other's configuration options 1289 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1290 uint16_t pos = 8; 1291 while (pos < end_pos){ 1292 uint8_t option_hint = command[pos] >> 7; 1293 uint8_t option_type = command[pos] & 0x7f; 1294 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1295 pos++; 1296 uint8_t length = command[pos++]; 1297 // MTU { type(8): 1, len(8):2, MTU(16) } 1298 if (option_type == 1 && length == 2){ 1299 channel->remote_mtu = little_endian_read_16(command, pos); 1300 // log_info("l2cap cid 0x%02x, remote mtu %u", channel->local_cid, channel->remote_mtu); 1301 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1302 } 1303 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1304 if (option_type == 2 && length == 2){ 1305 channel->flush_timeout = little_endian_read_16(command, pos); 1306 } 1307 // check for unknown options 1308 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1309 log_info("l2cap cid %u, unknown options", channel->local_cid); 1310 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1311 } 1312 pos += length; 1313 } 1314 } 1315 1316 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1317 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1318 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1319 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1320 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 1321 if (channel->state == L2CAP_STATE_OPEN) return 0; 1322 return 1; 1323 } 1324 1325 1326 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1327 1328 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1329 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1330 uint16_t result = 0; 1331 1332 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1333 1334 // handle DISCONNECT REQUESTS seperately 1335 if (code == DISCONNECTION_REQUEST){ 1336 switch (channel->state){ 1337 case L2CAP_STATE_CONFIG: 1338 case L2CAP_STATE_OPEN: 1339 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1340 case L2CAP_STATE_WAIT_DISCONNECT: 1341 l2cap_handle_disconnect_request(channel, identifier); 1342 break; 1343 1344 default: 1345 // ignore in other states 1346 break; 1347 } 1348 return; 1349 } 1350 1351 // @STATEMACHINE(l2cap) 1352 switch (channel->state) { 1353 1354 case L2CAP_STATE_WAIT_CONNECT_RSP: 1355 switch (code){ 1356 case CONNECTION_RESPONSE: 1357 l2cap_stop_rtx(channel); 1358 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1359 switch (result) { 1360 case 0: 1361 // successful connection 1362 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1363 channel->state = L2CAP_STATE_CONFIG; 1364 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1365 break; 1366 case 1: 1367 // connection pending. get some coffee, but start the ERTX 1368 l2cap_start_ertx(channel); 1369 break; 1370 default: 1371 // channel closed 1372 channel->state = L2CAP_STATE_CLOSED; 1373 // map l2cap connection response result to BTstack status enumeration 1374 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1375 1376 // drop link key if security block 1377 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1378 gap_drop_link_key_for_bd_addr(channel->address); 1379 } 1380 1381 // discard channel 1382 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1383 btstack_memory_l2cap_channel_free(channel); 1384 break; 1385 } 1386 break; 1387 1388 default: 1389 //@TODO: implement other signaling packets 1390 break; 1391 } 1392 break; 1393 1394 case L2CAP_STATE_CONFIG: 1395 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1396 switch (code) { 1397 case CONFIGURE_REQUEST: 1398 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1399 l2cap_signaling_handle_configure_request(channel, command); 1400 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1401 // only done if continuation not set 1402 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1403 } 1404 break; 1405 case CONFIGURE_RESPONSE: 1406 l2cap_stop_rtx(channel); 1407 switch (result){ 1408 case 0: // success 1409 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1410 break; 1411 case 4: // pending 1412 l2cap_start_ertx(channel); 1413 break; 1414 default: 1415 // retry on negative result 1416 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1417 break; 1418 } 1419 break; 1420 default: 1421 break; 1422 } 1423 if (l2cap_channel_ready_for_open(channel)){ 1424 // for open: 1425 channel->state = L2CAP_STATE_OPEN; 1426 l2cap_emit_channel_opened(channel, 0); 1427 } 1428 break; 1429 1430 case L2CAP_STATE_WAIT_DISCONNECT: 1431 switch (code) { 1432 case DISCONNECTION_RESPONSE: 1433 l2cap_finialize_channel_close(channel); 1434 break; 1435 default: 1436 //@TODO: implement other signaling packets 1437 break; 1438 } 1439 break; 1440 1441 case L2CAP_STATE_CLOSED: 1442 // @TODO handle incoming requests 1443 break; 1444 1445 case L2CAP_STATE_OPEN: 1446 //@TODO: implement other signaling packets, e.g. re-configure 1447 break; 1448 default: 1449 break; 1450 } 1451 // log_info("new state %u", channel->state); 1452 } 1453 1454 1455 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1456 1457 // get code, signalind identifier and command len 1458 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1459 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1460 1461 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1462 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1463 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1464 return; 1465 } 1466 1467 // general commands without an assigned channel 1468 switch(code) { 1469 1470 case CONNECTION_REQUEST: { 1471 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1472 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1473 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1474 return; 1475 } 1476 1477 case ECHO_REQUEST: 1478 l2cap_register_signaling_response(handle, code, sig_id, 0); 1479 return; 1480 1481 case INFORMATION_REQUEST: { 1482 uint16_t infoType = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1483 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1484 return; 1485 } 1486 1487 default: 1488 break; 1489 } 1490 1491 1492 // Get potential destination CID 1493 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1494 1495 // Find channel for this sig_id and connection handle 1496 btstack_linked_list_iterator_t it; 1497 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1498 while (btstack_linked_list_iterator_has_next(&it)){ 1499 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1500 if (channel->con_handle != handle) continue; 1501 if (code & 1) { 1502 // match odd commands (responses) by previous signaling identifier 1503 if (channel->local_sig_id == sig_id) { 1504 l2cap_signaling_handler_channel(channel, command); 1505 break; 1506 } 1507 } else { 1508 // match even commands (requests) by local channel id 1509 if (channel->local_cid == dest_cid) { 1510 l2cap_signaling_handler_channel(channel, command); 1511 break; 1512 } 1513 } 1514 } 1515 } 1516 1517 #ifdef ENABLE_BLE 1518 // @returns valid 1519 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 1520 hci_connection_t * connection; 1521 uint16_t result; 1522 uint8_t event[10]; 1523 uint16_t local_cid; 1524 l2cap_channel_t * channel; 1525 btstack_linked_list_iterator_t it; 1526 1527 #ifdef ENABLE_LE_DATA_CHANNEL 1528 uint16_t le_psm; 1529 uint16_t new_credits; 1530 uint16_t credits_before; 1531 l2cap_service_t * service; 1532 #endif 1533 1534 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1535 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 1536 1537 switch (code){ 1538 1539 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 1540 result = little_endian_read_16(command, 4); 1541 l2cap_emit_connection_parameter_update_response(handle, result); 1542 break; 1543 1544 case CONNECTION_PARAMETER_UPDATE_REQUEST: 1545 connection = hci_connection_for_handle(handle); 1546 if (connection){ 1547 if (connection->role != HCI_ROLE_MASTER){ 1548 // reject command without notifying upper layer when not in master role 1549 return 0; 1550 } 1551 int update_parameter = 1; 1552 le_connection_parameter_range_t existing_range; 1553 gap_get_connection_parameter_range(&existing_range); 1554 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 1555 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 1556 uint16_t le_conn_latency = little_endian_read_16(command,12); 1557 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 1558 1559 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 1560 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 1561 1562 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 1563 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 1564 1565 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 1566 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 1567 1568 if (update_parameter){ 1569 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 1570 connection->le_conn_interval_min = le_conn_interval_min; 1571 connection->le_conn_interval_max = le_conn_interval_max; 1572 connection->le_conn_latency = le_conn_latency; 1573 connection->le_supervision_timeout = le_supervision_timeout; 1574 } else { 1575 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 1576 } 1577 connection->le_con_param_update_identifier = sig_id; 1578 } 1579 1580 if (!l2cap_event_packet_handler) break; 1581 1582 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 1583 event[1] = 8; 1584 memcpy(&event[2], &command[4], 8); 1585 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1586 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1587 break; 1588 1589 case COMMAND_REJECT: 1590 // Find channel for this sig_id and connection handle 1591 channel = NULL; 1592 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1593 while (btstack_linked_list_iterator_has_next(&it)){ 1594 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1595 if (a_channel->con_handle != handle) continue; 1596 if (a_channel->local_sig_id != sig_id) continue; 1597 channel = a_channel; 1598 break; 1599 } 1600 if (!channel) break; 1601 1602 // if received while waiting for le connection response, assume legacy device 1603 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 1604 channel->state = L2CAP_STATE_CLOSED; 1605 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 1606 l2cap_emit_channel_opened(channel, 0x0002); 1607 1608 // discard channel 1609 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1610 btstack_memory_l2cap_channel_free(channel); 1611 break; 1612 } 1613 break; 1614 1615 #ifdef ENABLE_LE_DATA_CHANNEL 1616 case LE_CREDIT_BASED_CONNECTION_REQUEST: 1617 1618 // get hci connection, bail if not found (must not happen) 1619 connection = hci_connection_for_handle(handle); 1620 if (!connection) return 0; 1621 1622 // check if service registered 1623 le_psm = little_endian_read_16(command, 4); 1624 service = l2cap_le_get_service(le_psm); 1625 1626 if (service){ 1627 1628 uint16_t source_cid = little_endian_read_16(command, 6); 1629 if (source_cid < 0x40){ 1630 // 0x0009 Connection refused - Invalid Source CID 1631 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0009); 1632 return 1; 1633 } 1634 1635 // go through list of channels for this ACL connection and check if we get a match 1636 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1637 while (btstack_linked_list_iterator_has_next(&it)){ 1638 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1639 if (a_channel->con_handle != handle) continue; 1640 if (a_channel->remote_cid != source_cid) continue; 1641 // 0x000a Connection refused - Source CID already allocated 1642 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x000a); 1643 return 1; 1644 } 1645 1646 // security: check encryption 1647 if (service->required_security_level >= LEVEL_2){ 1648 if (sm_encryption_key_size(handle) == 0){ 1649 // 0x0008 Connection refused - insufficient encryption 1650 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0008); 1651 return 1; 1652 } 1653 // anything less than 16 byte key size is insufficient 1654 if (sm_encryption_key_size(handle) < 16){ 1655 // 0x0007 Connection refused – insufficient encryption key size 1656 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0007); 1657 return 1; 1658 } 1659 } 1660 1661 // security: check authencation 1662 if (service->required_security_level >= LEVEL_3){ 1663 if (!sm_authenticated(handle)){ 1664 // 0x0005 Connection refused – insufficient authentication 1665 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0005); 1666 return 1; 1667 } 1668 } 1669 1670 // security: check authorization 1671 if (service->required_security_level >= LEVEL_4){ 1672 if (sm_authorization_state(handle) != AUTHORIZATION_GRANTED){ 1673 // 0x0006 Connection refused – insufficient authorization 1674 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0006); 1675 return 1; 1676 } 1677 } 1678 1679 // allocate channel 1680 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 1681 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 1682 if (!channel){ 1683 // 0x0004 Connection refused – no resources available 1684 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0004); 1685 return 1; 1686 } 1687 1688 channel->con_handle = handle; 1689 channel->remote_cid = source_cid; 1690 channel->remote_sig_id = sig_id; 1691 channel->remote_mtu = little_endian_read_16(command, 8); 1692 channel->remote_mps = little_endian_read_16(command, 10); 1693 channel->credits_outgoing = little_endian_read_16(command, 12); 1694 1695 // set initial state 1696 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1697 1698 // add to connections list 1699 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1700 1701 // post connection request event 1702 l2cap_emit_connection_request(channel); 1703 1704 } else { 1705 // Connection refused – LE_PSM not supported 1706 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0002); 1707 } 1708 break; 1709 1710 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 1711 // Find channel for this sig_id and connection handle 1712 channel = NULL; 1713 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1714 while (btstack_linked_list_iterator_has_next(&it)){ 1715 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1716 if (a_channel->con_handle != handle) continue; 1717 if (a_channel->local_sig_id != sig_id) continue; 1718 channel = a_channel; 1719 break; 1720 } 1721 if (!channel) break; 1722 1723 // cid + 0 1724 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 1725 if (result){ 1726 channel->state = L2CAP_STATE_CLOSED; 1727 // map l2cap connection response result to BTstack status enumeration 1728 l2cap_emit_channel_opened(channel, result); 1729 1730 // discard channel 1731 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1732 btstack_memory_l2cap_channel_free(channel); 1733 break; 1734 } 1735 1736 // success 1737 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1738 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1739 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 1740 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 1741 channel->state = L2CAP_STATE_OPEN; 1742 l2cap_emit_channel_opened(channel, result); 1743 break; 1744 1745 case LE_FLOW_CONTROL_CREDIT: 1746 // find channel 1747 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1748 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1749 if (!channel) { 1750 log_error("l2cap: no channel for cid 0x%02x", local_cid); 1751 break; 1752 } 1753 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1754 credits_before = channel->credits_outgoing; 1755 channel->credits_outgoing += new_credits; 1756 // check for credit overrun 1757 if (credits_before > channel->credits_outgoing){ 1758 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 1759 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1760 break; 1761 } 1762 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 1763 break; 1764 #endif 1765 1766 case DISCONNECTION_REQUEST: 1767 // find channel 1768 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1769 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1770 if (!channel) { 1771 log_error("l2cap: no channel for cid 0x%02x", local_cid); 1772 break; 1773 } 1774 channel->remote_sig_id = sig_id; 1775 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1776 break; 1777 1778 case DISCONNECTION_RESPONSE: 1779 break; 1780 1781 default: 1782 // command unknown -> reject command 1783 return 0; 1784 } 1785 return 1; 1786 } 1787 #endif 1788 1789 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 1790 1791 // Get Channel ID 1792 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1793 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1794 1795 switch (channel_id) { 1796 1797 case L2CAP_CID_SIGNALING: { 1798 uint16_t command_offset = 8; 1799 while (command_offset < size) { 1800 // handle signaling commands 1801 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1802 1803 // increment command_offset 1804 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1805 } 1806 break; 1807 } 1808 1809 #ifdef ENABLE_BLE 1810 case L2CAP_CID_SIGNALING_LE: { 1811 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1812 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 1813 if (!valid){ 1814 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1815 } 1816 break; 1817 } 1818 #endif 1819 1820 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1821 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 1822 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1823 } 1824 break; 1825 1826 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1827 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 1828 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1829 } 1830 break; 1831 1832 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 1833 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 1834 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1835 } 1836 break; 1837 1838 default: { 1839 // Find channel for this channel_id and connection handle 1840 l2cap_channel_t * l2cap_channel; 1841 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 1842 if (l2cap_channel) { 1843 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1844 } 1845 #ifdef ENABLE_BLE 1846 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 1847 if (l2cap_channel) { 1848 // credit counting 1849 if (l2cap_channel->credits_incoming == 0){ 1850 log_error("LE Data Channel packet received but no incoming credits"); 1851 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1852 break; 1853 } 1854 l2cap_channel->credits_incoming--; 1855 1856 // automatic credits 1857 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 1858 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 1859 } 1860 1861 // first fragment 1862 uint16_t pos = 0; 1863 if (!l2cap_channel->receive_sdu_len){ 1864 l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 1865 l2cap_channel->receive_sdu_pos = 0; 1866 pos += 2; 1867 size -= 2; 1868 } 1869 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); 1870 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 1871 // done? 1872 log_info("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 1873 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 1874 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 1875 l2cap_channel->receive_sdu_len = 0; 1876 } 1877 } else { 1878 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 1879 } 1880 #endif 1881 break; 1882 } 1883 } 1884 1885 l2cap_run(); 1886 } 1887 1888 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1889 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 1890 channel->state = L2CAP_STATE_CLOSED; 1891 l2cap_emit_channel_closed(channel); 1892 // discard channel 1893 l2cap_stop_rtx(channel); 1894 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1895 btstack_memory_l2cap_channel_free(channel); 1896 } 1897 1898 #ifdef ENABLE_BLE 1899 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1900 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 1901 channel->state = L2CAP_STATE_CLOSED; 1902 l2cap_emit_channel_closed(channel); 1903 // discard channel 1904 l2cap_stop_rtx(channel); 1905 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1906 btstack_memory_l2cap_channel_free(channel); 1907 } 1908 #endif 1909 1910 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 1911 btstack_linked_list_iterator_t it; 1912 btstack_linked_list_iterator_init(&it, services); 1913 while (btstack_linked_list_iterator_has_next(&it)){ 1914 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 1915 if ( service->psm == psm){ 1916 return service; 1917 }; 1918 } 1919 return NULL; 1920 } 1921 1922 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 1923 return l2cap_get_service_internal(&l2cap_services, psm); 1924 } 1925 1926 1927 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 1928 1929 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1930 1931 // check for alread registered psm 1932 l2cap_service_t *service = l2cap_get_service(psm); 1933 if (service) { 1934 log_error("l2cap_register_service: PSM %u already registered", psm); 1935 return L2CAP_SERVICE_ALREADY_REGISTERED; 1936 } 1937 1938 // alloc structure 1939 service = btstack_memory_l2cap_service_get(); 1940 if (!service) { 1941 log_error("l2cap_register_service: no memory for l2cap_service_t"); 1942 return BTSTACK_MEMORY_ALLOC_FAILED; 1943 } 1944 1945 // fill in 1946 service->psm = psm; 1947 service->mtu = mtu; 1948 service->packet_handler = service_packet_handler; 1949 service->required_security_level = security_level; 1950 1951 // add to services list 1952 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 1953 1954 // enable page scan 1955 gap_connectable_control(1); 1956 1957 return 0; 1958 } 1959 1960 uint8_t l2cap_unregister_service(uint16_t psm){ 1961 1962 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1963 1964 l2cap_service_t *service = l2cap_get_service(psm); 1965 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 1966 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 1967 btstack_memory_l2cap_service_free(service); 1968 1969 // disable page scan when no services registered 1970 if (btstack_linked_list_empty(&l2cap_services)) { 1971 gap_connectable_control(0); 1972 } 1973 return 0; 1974 } 1975 1976 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1977 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 1978 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 1979 if (index < 0) return; 1980 fixed_channels[index].callback = the_packet_handler; 1981 } 1982 1983 #ifdef ENABLE_BLE 1984 1985 #ifdef ENABLE_LE_DATA_CHANNEL 1986 1987 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 1988 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 1989 } 1990 1991 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 1992 1993 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 1994 1995 // check for alread registered psm 1996 l2cap_service_t *service = l2cap_le_get_service(psm); 1997 if (service) { 1998 return L2CAP_SERVICE_ALREADY_REGISTERED; 1999 } 2000 2001 // alloc structure 2002 service = btstack_memory_l2cap_service_get(); 2003 if (!service) { 2004 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 2005 return BTSTACK_MEMORY_ALLOC_FAILED; 2006 } 2007 2008 // fill in 2009 service->psm = psm; 2010 service->mtu = 0; 2011 service->packet_handler = packet_handler; 2012 service->required_security_level = security_level; 2013 2014 // add to services list 2015 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 2016 2017 // done 2018 return 0; 2019 } 2020 2021 uint8_t l2cap_le_unregister_service(uint16_t psm) { 2022 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 2023 l2cap_service_t *service = l2cap_le_get_service(psm); 2024 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2025 2026 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 2027 btstack_memory_l2cap_service_free(service); 2028 return 0; 2029 } 2030 2031 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 2032 // get channel 2033 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2034 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2035 2036 // validate state 2037 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2038 return ERROR_CODE_COMMAND_DISALLOWED; 2039 } 2040 2041 // set state accept connection 2042 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 2043 channel->receive_sdu_buffer = receive_sdu_buffer; 2044 channel->local_mtu = mtu; 2045 channel->new_credits_incoming = initial_credits; 2046 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2047 2048 // test 2049 // channel->new_credits_incoming = 1; 2050 2051 // go 2052 l2cap_run(); 2053 return 0; 2054 } 2055 2056 /** 2057 * @brief Deny incoming LE Data Channel connection due to resource constraints 2058 * @param local_cid L2CAP LE Data Channel Identifier 2059 */ 2060 2061 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 2062 // get channel 2063 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2064 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2065 2066 // validate state 2067 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2068 return ERROR_CODE_COMMAND_DISALLOWED; 2069 } 2070 2071 // set state decline connection 2072 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 2073 channel->reason = 0x04; // no resources available 2074 l2cap_run(); 2075 return 0; 2076 } 2077 2078 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 2079 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 2080 uint16_t * out_local_cid) { 2081 2082 log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 2083 2084 2085 hci_connection_t * connection = hci_connection_for_handle(con_handle); 2086 if (!connection) { 2087 log_error("no hci_connection for handle 0x%04x", con_handle); 2088 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 2089 } 2090 2091 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, connection->address, connection->address_type, psm, mtu, security_level); 2092 if (!channel) { 2093 return BTSTACK_MEMORY_ALLOC_FAILED; 2094 } 2095 log_info("l2cap_le_create_channel %p", channel); 2096 2097 // store local_cid 2098 if (out_local_cid){ 2099 *out_local_cid = channel->local_cid; 2100 } 2101 2102 // provide buffer 2103 channel->con_handle = con_handle; 2104 channel->receive_sdu_buffer = receive_sdu_buffer; 2105 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 2106 channel->new_credits_incoming = initial_credits; 2107 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2108 2109 // add to connections list 2110 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2111 2112 // go 2113 l2cap_run(); 2114 return 0; 2115 } 2116 2117 /** 2118 * @brief Provide credtis for LE Data Channel 2119 * @param local_cid L2CAP LE Data Channel Identifier 2120 * @param credits Number additional credits for peer 2121 */ 2122 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 2123 2124 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2125 if (!channel) { 2126 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2127 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2128 } 2129 2130 // check state 2131 if (channel->state != L2CAP_STATE_OPEN){ 2132 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 2133 } 2134 2135 // assert incoming credits + credits <= 0xffff 2136 uint32_t total_credits = channel->credits_incoming; 2137 total_credits += channel->new_credits_incoming; 2138 total_credits += credits; 2139 if (total_credits > 0xffff){ 2140 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 2141 channel->new_credits_incoming, credits); 2142 } 2143 2144 // set credits_granted 2145 channel->new_credits_incoming += credits; 2146 2147 // go 2148 l2cap_run(); 2149 return 0; 2150 } 2151 2152 /** 2153 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 2154 * @param local_cid L2CAP LE Data Channel Identifier 2155 */ 2156 int l2cap_le_can_send_now(uint16_t local_cid){ 2157 // check if data can be sent via le at all 2158 return 0; 2159 } 2160 2161 /** 2162 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 2163 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 2164 * so packet handler should be ready to handle it 2165 * @param local_cid L2CAP LE Data Channel Identifier 2166 */ 2167 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 2168 // same as for non-le 2169 return 0; 2170 } 2171 2172 /** 2173 * @brief Send data via LE Data Channel 2174 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 2175 * @param local_cid L2CAP LE Data Channel Identifier 2176 * @param data data to send 2177 * @param size data size 2178 */ 2179 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 2180 2181 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2182 if (!channel) { 2183 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2184 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2185 } 2186 2187 if (len > channel->remote_mtu){ 2188 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 2189 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 2190 } 2191 2192 if (channel->send_sdu_buffer){ 2193 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 2194 return BTSTACK_ACL_BUFFERS_FULL; 2195 } 2196 2197 channel->send_sdu_buffer = data; 2198 channel->send_sdu_len = len; 2199 channel->send_sdu_pos = 0; 2200 2201 l2cap_run(); 2202 return 0; 2203 } 2204 2205 /** 2206 * @brief Disconnect from LE Data Channel 2207 * @param local_cid L2CAP LE Data Channel Identifier 2208 */ 2209 uint8_t l2cap_le_disconnect(uint16_t local_cid) 2210 { 2211 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2212 if (!channel) { 2213 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2214 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2215 } 2216 2217 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2218 l2cap_run(); 2219 return 0; 2220 } 2221 2222 #endif 2223 2224 #endif 2225