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 #include <stdarg.h> 54 #include <string.h> 55 56 #include <stdio.h> 57 58 // nr of buffered acl packets in outgoing queue to get max performance 59 #define NR_BUFFERED_ACL_PACKETS 3 60 61 // used to cache l2cap rejects, echo, and informational requests 62 #define NR_PENDING_SIGNALING_RESPONSES 3 63 64 // nr of credits provided to remote if credits fall below watermark 65 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK 5 66 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT 5 67 68 // offsets for L2CAP SIGNALING COMMANDS 69 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 70 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 71 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 72 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 73 74 // internal table 75 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL 0 76 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL 1 77 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL 2 78 #define L2CAP_FIXED_CHANNEL_TABLE_SIZE (L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL+1) 79 80 // prototypes 81 static void l2cap_finialize_channel_close(l2cap_channel_t *channel); 82 static inline l2cap_service_t * l2cap_get_service(uint16_t psm); 83 static void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status); 84 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel); 85 static void l2cap_emit_channel_closed(l2cap_channel_t *channel); 86 static void l2cap_emit_connection_request(l2cap_channel_t *channel); 87 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); 88 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); 89 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ); 90 static void l2cap_notify_channel_can_send(void); 91 #ifdef ENABLE_BLE 92 static void l2cap_le_finialize_channel_close(l2cap_channel_t *channel); 93 static inline l2cap_service_t * l2cap_le_get_service(uint16_t psm); 94 #endif 95 96 typedef struct l2cap_fixed_channel { 97 btstack_packet_handler_t callback; 98 uint8_t waiting_for_can_send_now; 99 } l2cap_fixed_channel_t; 100 101 static btstack_linked_list_t l2cap_channels; 102 static btstack_linked_list_t l2cap_services; 103 static btstack_linked_list_t l2cap_le_channels; 104 static btstack_linked_list_t l2cap_le_services; 105 106 // used to cache l2cap rejects, echo, and informational requests 107 static l2cap_signaling_response_t signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; 108 static int signaling_responses_pending; 109 110 static uint8_t require_security_level2_for_outgoing_sdp; 111 112 static btstack_packet_callback_registration_t hci_event_callback_registration; 113 114 static btstack_packet_handler_t l2cap_event_packet_handler; 115 static l2cap_fixed_channel_t fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_SIZE]; 116 117 static uint16_t l2cap_fixed_channel_table_channel_id_for_index(int index){ 118 switch (index){ 119 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL: 120 return L2CAP_CID_ATTRIBUTE_PROTOCOL; 121 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL: 122 return L2CAP_CID_SECURITY_MANAGER_PROTOCOL; 123 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL: 124 return L2CAP_CID_CONNECTIONLESS_CHANNEL; 125 default: 126 return 0; 127 } 128 } 129 static int l2cap_fixed_channel_table_index_for_channel_id(uint16_t channel_id){ 130 switch (channel_id){ 131 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 132 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL; 133 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 134 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL; 135 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 136 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL; 137 default: 138 return -1; 139 } 140 } 141 142 static int l2cap_fixed_channel_table_index_is_le(int index){ 143 if (index == L2CAP_CID_CONNECTIONLESS_CHANNEL) return 0; 144 return 1; 145 } 146 147 void l2cap_init(void){ 148 signaling_responses_pending = 0; 149 150 l2cap_channels = NULL; 151 l2cap_services = NULL; 152 l2cap_le_services = NULL; 153 l2cap_le_channels = NULL; 154 155 l2cap_event_packet_handler = NULL; 156 memset(fixed_channels, 0, sizeof(fixed_channels)); 157 158 require_security_level2_for_outgoing_sdp = 0; 159 160 // 161 // register callback with HCI 162 // 163 hci_event_callback_registration.callback = &l2cap_hci_event_handler; 164 hci_add_event_handler(&hci_event_callback_registration); 165 166 hci_register_acl_packet_handler(&l2cap_acl_handler); 167 168 gap_connectable_control(0); // no services yet 169 } 170 171 void l2cap_register_packet_handler(void (*handler)(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 172 l2cap_event_packet_handler = handler; 173 } 174 175 static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 176 (* (channel->packet_handler))(type, channel->local_cid, data, size); 177 } 178 179 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 180 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", 181 status, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 182 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 183 uint8_t event[23]; 184 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 185 event[1] = sizeof(event) - 2; 186 event[2] = status; 187 reverse_bd_addr(channel->address, &event[3]); 188 little_endian_store_16(event, 9, channel->con_handle); 189 little_endian_store_16(event, 11, channel->psm); 190 little_endian_store_16(event, 13, channel->local_cid); 191 little_endian_store_16(event, 15, channel->remote_cid); 192 little_endian_store_16(event, 17, channel->local_mtu); 193 little_endian_store_16(event, 19, channel->remote_mtu); 194 little_endian_store_16(event, 21, channel->flush_timeout); 195 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 196 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 197 } 198 199 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 200 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 201 uint8_t event[4]; 202 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 203 event[1] = sizeof(event) - 2; 204 little_endian_store_16(event, 2, channel->local_cid); 205 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 206 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 207 } 208 209 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 210 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 211 bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid); 212 uint8_t event[16]; 213 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 214 event[1] = sizeof(event) - 2; 215 reverse_bd_addr(channel->address, &event[2]); 216 little_endian_store_16(event, 8, channel->con_handle); 217 little_endian_store_16(event, 10, channel->psm); 218 little_endian_store_16(event, 12, channel->local_cid); 219 little_endian_store_16(event, 14, channel->remote_cid); 220 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 221 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 222 } 223 224 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel) { 225 log_info("L2CAP_EVENT_CHANNEL_CAN_SEND_NOW local_cid 0x%x", channel); 226 uint8_t event[4]; 227 event[0] = L2CAP_EVENT_CAN_SEND_NOW; 228 event[1] = sizeof(event) - 2; 229 little_endian_store_16(event, 2, channel); 230 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 231 packet_handler(HCI_EVENT_PACKET, channel, event, sizeof(event)); 232 } 233 234 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 235 uint8_t event[6]; 236 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 237 event[1] = 4; 238 little_endian_store_16(event, 2, con_handle); 239 little_endian_store_16(event, 4, result); 240 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 241 if (!l2cap_event_packet_handler) return; 242 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 243 } 244 245 static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 246 btstack_linked_list_iterator_t it; 247 btstack_linked_list_iterator_init(&it, &l2cap_channels); 248 while (btstack_linked_list_iterator_has_next(&it)){ 249 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 250 if ( channel->local_cid == local_cid) { 251 return channel; 252 } 253 } 254 return NULL; 255 } 256 257 #ifdef ENABLE_BLE 258 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 259 btstack_linked_list_iterator_t it; 260 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 261 while (btstack_linked_list_iterator_has_next(&it)){ 262 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 263 if ( channel->local_cid == local_cid) { 264 return channel; 265 } 266 } 267 return NULL; 268 } 269 #endif 270 271 /// 272 273 void l2cap_request_can_send_now_event(uint16_t local_cid){ 274 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 275 if (!channel) return; 276 channel->waiting_for_can_send_now = 1; 277 l2cap_notify_channel_can_send(); 278 } 279 280 void l2cap_request_can_send_fix_channel_now_event(hci_con_handle_t con_handle, uint16_t channel_id){ 281 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 282 if (index < 0) return; 283 fixed_channels[index].waiting_for_can_send_now = 1; 284 l2cap_notify_channel_can_send(); 285 } 286 287 /// 288 289 int l2cap_can_send_packet_now(uint16_t local_cid){ 290 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 291 if (!channel) return 0; 292 return hci_can_send_acl_packet_now(channel->con_handle); 293 } 294 295 int l2cap_can_send_prepared_packet_now(uint16_t local_cid){ 296 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 297 if (!channel) return 0; 298 return hci_can_send_prepared_acl_packet_now(channel->con_handle); 299 } 300 301 int l2cap_can_send_fixed_channel_packet_now(hci_con_handle_t con_handle, uint16_t channel_id){ 302 return hci_can_send_acl_packet_now(con_handle); 303 } 304 305 /// 306 307 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 308 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 309 if (channel) { 310 return channel->remote_mtu; 311 } 312 return 0; 313 } 314 315 static l2cap_channel_t * l2cap_channel_for_rtx_timer(btstack_timer_source_t * ts){ 316 btstack_linked_list_iterator_t it; 317 btstack_linked_list_iterator_init(&it, &l2cap_channels); 318 while (btstack_linked_list_iterator_has_next(&it)){ 319 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 320 if ( &channel->rtx == ts) { 321 return channel; 322 } 323 } 324 return NULL; 325 } 326 327 static void l2cap_rtx_timeout(btstack_timer_source_t * ts){ 328 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 329 if (!channel) return; 330 331 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 332 333 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 334 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 335 // notify client 336 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 337 338 // discard channel 339 // no need to stop timer here, it is removed from list during timer callback 340 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 341 btstack_memory_l2cap_channel_free(channel); 342 } 343 344 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 345 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 346 btstack_run_loop_remove_timer(&channel->rtx); 347 } 348 349 static void l2cap_start_rtx(l2cap_channel_t * channel){ 350 l2cap_stop_rtx(channel); 351 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 352 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 353 btstack_run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 354 btstack_run_loop_add_timer(&channel->rtx); 355 } 356 357 static void l2cap_start_ertx(l2cap_channel_t * channel){ 358 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 359 l2cap_stop_rtx(channel); 360 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 361 btstack_run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 362 btstack_run_loop_add_timer(&channel->rtx); 363 } 364 365 void l2cap_require_security_level_2_for_outgoing_sdp(void){ 366 require_security_level2_for_outgoing_sdp = 1; 367 } 368 369 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 370 return (psm == PSM_SDP) && (!require_security_level2_for_outgoing_sdp); 371 } 372 373 static int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 374 375 if (!hci_can_send_acl_packet_now(handle)){ 376 log_info("l2cap_send_signaling_packet, cannot send"); 377 return BTSTACK_ACL_BUFFERS_FULL; 378 } 379 380 // log_info("l2cap_send_signaling_packet type %u", cmd); 381 hci_reserve_packet_buffer(); 382 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 383 va_list argptr; 384 va_start(argptr, identifier); 385 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 386 va_end(argptr); 387 // log_info("l2cap_send_signaling_packet con %u!", handle); 388 return hci_send_acl_packet_buffer(len); 389 } 390 391 #ifdef ENABLE_BLE 392 static int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 393 394 if (!hci_can_send_acl_packet_now(handle)){ 395 log_info("l2cap_send_signaling_packet, cannot send"); 396 return BTSTACK_ACL_BUFFERS_FULL; 397 } 398 399 // log_info("l2cap_send_signaling_packet type %u", cmd); 400 hci_reserve_packet_buffer(); 401 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 402 va_list argptr; 403 va_start(argptr, identifier); 404 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 405 va_end(argptr); 406 // log_info("l2cap_send_signaling_packet con %u!", handle); 407 return hci_send_acl_packet_buffer(len); 408 } 409 #endif 410 411 uint8_t *l2cap_get_outgoing_buffer(void){ 412 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 413 } 414 415 int l2cap_reserve_packet_buffer(void){ 416 return hci_reserve_packet_buffer(); 417 } 418 419 void l2cap_release_packet_buffer(void){ 420 hci_release_packet_buffer(); 421 } 422 423 static void l2cap_setup_header(uint8_t * acl_buffer, hci_con_handle_t con_handle, uint16_t remote_cid, uint16_t len){ 424 425 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 426 427 // 0 - Connection handle : PB=pb : BC=00 428 little_endian_store_16(acl_buffer, 0, con_handle | (pb << 12) | (0 << 14)); 429 // 2 - ACL length 430 little_endian_store_16(acl_buffer, 2, len + 4); 431 // 4 - L2CAP packet length 432 little_endian_store_16(acl_buffer, 4, len + 0); 433 // 6 - L2CAP channel DEST 434 little_endian_store_16(acl_buffer, 6, remote_cid); 435 } 436 437 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 438 439 if (!hci_is_packet_buffer_reserved()){ 440 log_error("l2cap_send_prepared called without reserving packet first"); 441 return BTSTACK_ACL_BUFFERS_FULL; 442 } 443 444 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 445 if (!channel) { 446 log_error("l2cap_send_prepared no channel for cid 0x%02x", local_cid); 447 return -1; // TODO: define error 448 } 449 450 if (!hci_can_send_prepared_acl_packet_now(channel->con_handle)){ 451 log_info("l2cap_send_prepared cid 0x%02x, cannot send", local_cid); 452 return BTSTACK_ACL_BUFFERS_FULL; 453 } 454 455 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used", local_cid, channel->con_handle); 456 457 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 458 l2cap_setup_header(acl_buffer, channel->con_handle, channel->remote_cid, len); 459 // send 460 return hci_send_acl_packet_buffer(len+8); 461 } 462 463 int l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len){ 464 465 if (!hci_is_packet_buffer_reserved()){ 466 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 467 return BTSTACK_ACL_BUFFERS_FULL; 468 } 469 470 if (!hci_can_send_prepared_acl_packet_now(con_handle)){ 471 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send", con_handle, cid); 472 return BTSTACK_ACL_BUFFERS_FULL; 473 } 474 475 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x", con_handle, cid); 476 477 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 478 l2cap_setup_header(acl_buffer, con_handle, cid, len); 479 // send 480 return hci_send_acl_packet_buffer(len+8); 481 } 482 483 int l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len){ 484 485 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 486 if (!channel) { 487 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 488 return -1; // TODO: define error 489 } 490 491 if (len > channel->remote_mtu){ 492 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 493 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 494 } 495 496 if (!hci_can_send_acl_packet_now(channel->con_handle)){ 497 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 498 return BTSTACK_ACL_BUFFERS_FULL; 499 } 500 501 hci_reserve_packet_buffer(); 502 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 503 504 memcpy(&acl_buffer[8], data, len); 505 506 return l2cap_send_prepared(local_cid, len); 507 } 508 509 int l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len){ 510 511 if (!hci_can_send_acl_packet_now(con_handle)){ 512 log_info("l2cap_send cid 0x%02x, cannot send", 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_connectionless(con_handle, 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 } 535 536 537 538 // MARK: L2CAP_RUN 539 // process outstanding signaling tasks 540 static void l2cap_run(void){ 541 542 // log_info("l2cap_run: entered"); 543 544 // check pending signaling responses 545 while (signaling_responses_pending){ 546 547 hci_con_handle_t handle = signaling_responses[0].handle; 548 549 if (!hci_can_send_acl_packet_now(handle)) break; 550 551 uint8_t sig_id = signaling_responses[0].sig_id; 552 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 553 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 554 uint8_t response_code = signaling_responses[0].code; 555 556 // remove first item before sending (to avoid sending response mutliple times) 557 signaling_responses_pending--; 558 int i; 559 for (i=0; i < signaling_responses_pending; i++){ 560 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 561 } 562 563 switch (response_code){ 564 case CONNECTION_REQUEST: 565 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 566 // also disconnect if result is 0x0003 - security blocked 567 if (result == 0x0003){ 568 hci_disconnect_security_block(handle); 569 } 570 break; 571 case ECHO_REQUEST: 572 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 573 break; 574 case INFORMATION_REQUEST: 575 switch (infoType){ 576 case 1: { // Connectionless MTU 577 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 578 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 579 break; 580 } 581 case 2: { // Extended Features Supported 582 // extended features request supported, features: fixed channels, unicast connectionless data reception 583 uint32_t features = 0x280; 584 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 585 break; 586 } 587 case 3: { // Fixed Channels Supported 588 uint8_t map[8]; 589 memset(map, 0, 8); 590 map[0] = 0x06; // L2CAP Signaling Channel (0x02) + Connectionless reception (0x04) 591 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 592 break; 593 } 594 default: 595 // all other types are not supported 596 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 597 break; 598 } 599 break; 600 case COMMAND_REJECT: 601 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 602 break; 603 #ifdef ENABLE_BLE 604 case LE_CREDIT_BASED_CONNECTION_REQUEST: 605 l2cap_send_le_signaling_packet(handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, sig_id, 0, 0, 0, 0, result); 606 break; 607 case COMMAND_REJECT_LE: 608 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 609 break; 610 #endif 611 default: 612 // should not happen 613 break; 614 } 615 } 616 617 uint8_t config_options[4]; 618 btstack_linked_list_iterator_t it; 619 btstack_linked_list_iterator_init(&it, &l2cap_channels); 620 while (btstack_linked_list_iterator_has_next(&it)){ 621 622 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 623 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 624 switch (channel->state){ 625 626 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 627 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 628 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 629 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 630 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 631 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 632 } 633 break; 634 635 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 636 if (!hci_can_send_command_packet_now()) break; 637 // send connection request - set state first 638 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 639 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 640 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 641 break; 642 643 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 644 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 645 channel->state = L2CAP_STATE_INVALID; 646 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 647 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 648 l2cap_stop_rtx(channel); 649 btstack_linked_list_iterator_remove(&it); 650 btstack_memory_l2cap_channel_free(channel); 651 break; 652 653 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 654 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 655 channel->state = L2CAP_STATE_CONFIG; 656 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 657 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 658 break; 659 660 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 661 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 662 // success, start l2cap handshake 663 channel->local_sig_id = l2cap_next_sig_id(); 664 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 665 l2cap_send_signaling_packet( channel->con_handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 666 l2cap_start_rtx(channel); 667 break; 668 669 case L2CAP_STATE_CONFIG: 670 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 671 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 672 uint16_t flags = 0; 673 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 674 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 675 flags = 1; 676 } else { 677 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 678 } 679 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 680 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 681 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 682 config_options[0] = 1; // MTU 683 config_options[1] = 2; // len param 684 little_endian_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 685 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 686 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 687 } else { 688 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 689 } 690 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 691 } 692 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 693 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 694 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 695 channel->local_sig_id = l2cap_next_sig_id(); 696 config_options[0] = 1; // MTU 697 config_options[1] = 2; // len param 698 little_endian_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 699 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 700 l2cap_start_rtx(channel); 701 } 702 if (l2cap_channel_ready_for_open(channel)){ 703 channel->state = L2CAP_STATE_OPEN; 704 l2cap_emit_channel_opened(channel, 0); // success 705 } 706 break; 707 708 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 709 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 710 channel->state = L2CAP_STATE_INVALID; 711 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 712 // 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 :) 713 l2cap_finialize_channel_close(channel); // -- remove from list 714 break; 715 716 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 717 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 718 channel->local_sig_id = l2cap_next_sig_id(); 719 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 720 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 721 break; 722 default: 723 break; 724 } 725 } 726 727 #ifdef ENABLE_BLE 728 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 729 while (btstack_linked_list_iterator_has_next(&it)){ 730 uint8_t * acl_buffer; 731 uint8_t * l2cap_payload; 732 uint16_t pos; 733 uint16_t payload_size; 734 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 735 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 736 switch (channel->state){ 737 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 738 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 739 channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; 740 // le psm, source cid, mtu, mps, initial credits 741 channel->local_sig_id = l2cap_next_sig_id(); 742 channel->credits_incoming = channel->new_credits_incoming; 743 channel->new_credits_incoming = 0; 744 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); 745 break; 746 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 747 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 748 // TODO: support larger MPS 749 channel->state = L2CAP_STATE_OPEN; 750 channel->credits_incoming = channel->new_credits_incoming; 751 channel->new_credits_incoming = 0; 752 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); 753 // notify client 754 l2cap_emit_channel_opened(channel, 0); 755 break; 756 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 757 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 758 channel->state = L2CAP_STATE_INVALID; 759 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, 0, 0, channel->reason); 760 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 761 l2cap_stop_rtx(channel); 762 btstack_linked_list_iterator_remove(&it); 763 btstack_memory_l2cap_channel_free(channel); 764 break; 765 case L2CAP_STATE_OPEN: 766 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 767 768 // send credits 769 if (channel->new_credits_incoming){ 770 log_info("l2cap: sending %u credits", channel->new_credits_incoming); 771 channel->local_sig_id = l2cap_next_sig_id(); 772 uint16_t new_credits = channel->new_credits_incoming; 773 channel->new_credits_incoming = 0; 774 channel->credits_incoming += new_credits; 775 l2cap_send_le_signaling_packet(channel->con_handle, LE_FLOW_CONTROL_CREDIT, channel->local_sig_id, channel->remote_cid, new_credits); 776 break; 777 } 778 779 // send data 780 if (!channel->send_sdu_buffer) break; 781 if (!channel->credits_outgoing) break; 782 783 // send part of SDU 784 hci_reserve_packet_buffer(); 785 acl_buffer = hci_get_outgoing_packet_buffer(); 786 l2cap_payload = acl_buffer + 8; 787 pos = 0; 788 if (!channel->send_sdu_pos){ 789 // store SDU len 790 channel->send_sdu_pos += 2; 791 little_endian_store_16(l2cap_payload, pos, channel->send_sdu_len); 792 pos += 2; 793 } 794 payload_size = btstack_min(channel->send_sdu_len + 2 - channel->send_sdu_pos, channel->remote_mps - pos); 795 log_info("len %u, pos %u => payload %u, credits %u", channel->send_sdu_len, channel->send_sdu_pos, payload_size, channel->credits_outgoing); 796 memcpy(&l2cap_payload[pos], &channel->send_sdu_buffer[channel->send_sdu_pos-2], payload_size); // -2 for virtual SDU len 797 pos += payload_size; 798 channel->send_sdu_pos += payload_size; 799 l2cap_setup_header(acl_buffer, channel->con_handle, channel->remote_cid, pos); 800 // done 801 802 channel->credits_outgoing--; 803 804 if (channel->send_sdu_pos >= channel->send_sdu_len + 2){ 805 channel->send_sdu_buffer = NULL; 806 // TODO: send done event 807 } 808 hci_send_acl_packet_buffer(8 + pos); 809 break; 810 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 811 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 812 channel->local_sig_id = l2cap_next_sig_id(); 813 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 814 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 815 break; 816 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 817 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 818 channel->state = L2CAP_STATE_INVALID; 819 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 820 l2cap_le_finialize_channel_close(channel); // -- remove from list 821 break; 822 default: 823 break; 824 } 825 } 826 827 // send l2cap con paramter update if necessary 828 hci_connections_get_iterator(&it); 829 while(btstack_linked_list_iterator_has_next(&it)){ 830 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 831 if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; 832 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 833 switch (connection->le_con_parameter_update_state){ 834 case CON_PARAMETER_UPDATE_SEND_REQUEST: 835 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 836 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, connection->le_con_param_update_identifier, 837 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 838 break; 839 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 840 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 841 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 842 break; 843 case CON_PARAMETER_UPDATE_DENY: 844 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 845 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 846 break; 847 default: 848 break; 849 } 850 } 851 #endif 852 853 // log_info("l2cap_run: exit"); 854 } 855 856 uint16_t l2cap_max_mtu(void){ 857 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 858 } 859 860 uint16_t l2cap_max_le_mtu(void){ 861 return l2cap_max_mtu(); 862 } 863 864 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 865 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 866 log_info("l2cap_handle_connection_complete expected state"); 867 // success, start l2cap handshake 868 channel->con_handle = con_handle; 869 // check remote SSP feature first 870 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 871 } 872 } 873 874 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 875 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 876 877 // we have been waiting for remote supported features, if both support SSP, 878 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)); 879 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 880 // request security level 2 881 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 882 gap_request_security_level(channel->con_handle, LEVEL_2); 883 return; 884 } 885 // fine, go ahead 886 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 887 } 888 889 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 890 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 891 892 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 893 if (!channel) { 894 return NULL; 895 } 896 897 // Init memory (make valgrind happy) 898 memset(channel, 0, sizeof(l2cap_channel_t)); 899 900 // fill in 901 channel->packet_handler = packet_handler; 902 bd_addr_copy(channel->address, address); 903 channel->address_type = address_type; 904 channel->psm = psm; 905 channel->local_mtu = local_mtu; 906 channel->remote_mtu = L2CAP_MINIMAL_MTU; 907 channel->required_security_level = security_level; 908 909 // 910 channel->local_cid = l2cap_next_local_cid(); 911 channel->con_handle = 0; 912 913 // set initial state 914 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 915 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 916 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 917 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 918 return channel; 919 } 920 921 /** 922 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 923 * @param packet_handler 924 * @param address 925 * @param psm 926 * @param mtu 927 * @param local_cid 928 */ 929 930 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){ 931 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, local_mtu); 932 933 if (local_mtu > l2cap_max_mtu()) { 934 local_mtu = l2cap_max_mtu(); 935 } 936 937 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 938 if (!channel) { 939 return BTSTACK_MEMORY_ALLOC_FAILED; 940 } 941 942 // add to connections list 943 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 944 945 // store local_cid 946 if (out_local_cid){ 947 *out_local_cid = channel->local_cid; 948 } 949 950 // check if hci connection is already usable 951 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 952 if (conn){ 953 log_info("l2cap_create_channel, hci connection already exists"); 954 l2cap_handle_connection_complete(conn->con_handle, channel); 955 // check if remote supported fearures are already received 956 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 957 l2cap_handle_remote_supported_features_received(channel); 958 } 959 } 960 961 l2cap_run(); 962 963 return 0; 964 } 965 966 void 967 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 968 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 969 // find channel for local_cid 970 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 971 if (channel) { 972 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 973 } 974 // process 975 l2cap_run(); 976 } 977 978 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 979 btstack_linked_list_iterator_t it; 980 btstack_linked_list_iterator_init(&it, &l2cap_channels); 981 while (btstack_linked_list_iterator_has_next(&it)){ 982 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 983 if ( bd_addr_cmp( channel->address, address) != 0) continue; 984 // channel for this address found 985 switch (channel->state){ 986 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 987 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 988 // failure, forward error code 989 l2cap_emit_channel_opened(channel, status); 990 // discard channel 991 l2cap_stop_rtx(channel); 992 btstack_linked_list_iterator_remove(&it); 993 btstack_memory_l2cap_channel_free(channel); 994 break; 995 default: 996 break; 997 } 998 } 999 } 1000 1001 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1002 btstack_linked_list_iterator_t it; 1003 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1004 while (btstack_linked_list_iterator_has_next(&it)){ 1005 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1006 if ( ! bd_addr_cmp( channel->address, address) ){ 1007 l2cap_handle_connection_complete(handle, channel); 1008 } 1009 } 1010 // process 1011 l2cap_run(); 1012 } 1013 1014 static void l2cap_notify_channel_can_send(void){ 1015 btstack_linked_list_iterator_t it; 1016 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1017 while (btstack_linked_list_iterator_has_next(&it)){ 1018 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1019 if (!channel->waiting_for_can_send_now) continue; 1020 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1021 channel->waiting_for_can_send_now = 0; 1022 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1023 } 1024 1025 int i; 1026 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1027 if (!fixed_channels[i].callback) continue; 1028 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1029 int can_send; 1030 if (l2cap_fixed_channel_table_index_is_le(i)){ 1031 can_send = hci_can_send_acl_le_packet_now(); 1032 } else { 1033 can_send = hci_can_send_acl_classic_packet_now(); 1034 } 1035 if (!can_send) continue; 1036 fixed_channels[i].waiting_for_can_send_now = 0; 1037 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1038 } 1039 } 1040 1041 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1042 1043 bd_addr_t address; 1044 hci_con_handle_t handle; 1045 btstack_linked_list_iterator_t it; 1046 int hci_con_used; 1047 1048 switch(hci_event_packet_get_type(packet)){ 1049 1050 // handle connection complete events 1051 case HCI_EVENT_CONNECTION_COMPLETE: 1052 reverse_bd_addr(&packet[5], address); 1053 if (packet[2] == 0){ 1054 handle = little_endian_read_16(packet, 3); 1055 l2cap_handle_connection_success_for_addr(address, handle); 1056 } else { 1057 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1058 } 1059 break; 1060 1061 // handle successful create connection cancel command 1062 case HCI_EVENT_COMMAND_COMPLETE: 1063 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1064 if (packet[5] == 0){ 1065 reverse_bd_addr(&packet[6], address); 1066 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1067 l2cap_handle_connection_failed_for_addr(address, 0x16); 1068 } 1069 } 1070 l2cap_run(); // try sending signaling packets first 1071 break; 1072 1073 case HCI_EVENT_COMMAND_STATUS: 1074 l2cap_run(); // try sending signaling packets first 1075 break; 1076 1077 // handle disconnection complete events 1078 case HCI_EVENT_DISCONNECTION_COMPLETE: 1079 // send l2cap disconnect events for all channels on this handle and free them 1080 handle = little_endian_read_16(packet, 3); 1081 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1082 while (btstack_linked_list_iterator_has_next(&it)){ 1083 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1084 if (channel->con_handle != handle) continue; 1085 l2cap_emit_channel_closed(channel); 1086 l2cap_stop_rtx(channel); 1087 btstack_linked_list_iterator_remove(&it); 1088 btstack_memory_l2cap_channel_free(channel); 1089 } 1090 #ifdef ENABLE_BLE 1091 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1092 while (btstack_linked_list_iterator_has_next(&it)){ 1093 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1094 if (channel->con_handle != handle) continue; 1095 l2cap_emit_channel_closed(channel); 1096 btstack_linked_list_iterator_remove(&it); 1097 btstack_memory_l2cap_channel_free(channel); 1098 } 1099 #endif 1100 break; 1101 1102 // Notify channel packet handler if they can send now 1103 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1104 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1105 l2cap_run(); // try sending signaling packets first 1106 l2cap_notify_channel_can_send(); 1107 break; 1108 1109 // HCI Connection Timeouts 1110 case L2CAP_EVENT_TIMEOUT_CHECK: 1111 handle = little_endian_read_16(packet, 2); 1112 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1113 if (hci_authentication_active_for_handle(handle)) break; 1114 hci_con_used = 0; 1115 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1116 while (btstack_linked_list_iterator_has_next(&it)){ 1117 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1118 if (channel->con_handle != handle) continue; 1119 hci_con_used = 1; 1120 break; 1121 } 1122 if (hci_con_used) break; 1123 if (!hci_can_send_command_packet_now()) break; 1124 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1125 break; 1126 1127 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1128 handle = little_endian_read_16(packet, 3); 1129 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1130 while (btstack_linked_list_iterator_has_next(&it)){ 1131 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1132 if (channel->con_handle != handle) continue; 1133 l2cap_handle_remote_supported_features_received(channel); 1134 break; 1135 } 1136 break; 1137 1138 case GAP_EVENT_SECURITY_LEVEL: 1139 handle = little_endian_read_16(packet, 2); 1140 log_info("l2cap - security level update"); 1141 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1142 while (btstack_linked_list_iterator_has_next(&it)){ 1143 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1144 if (channel->con_handle != handle) continue; 1145 1146 log_info("l2cap - state %u", channel->state); 1147 1148 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1149 gap_security_level_t required_level = channel->required_security_level; 1150 1151 switch (channel->state){ 1152 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1153 if (actual_level >= required_level){ 1154 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1155 l2cap_emit_connection_request(channel); 1156 } else { 1157 channel->reason = 0x0003; // security block 1158 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1159 } 1160 break; 1161 1162 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1163 if (actual_level >= required_level){ 1164 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1165 } else { 1166 // disconnnect, authentication not good enough 1167 hci_disconnect_security_block(handle); 1168 } 1169 break; 1170 1171 default: 1172 break; 1173 } 1174 } 1175 break; 1176 1177 default: 1178 break; 1179 } 1180 1181 l2cap_run(); 1182 } 1183 1184 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1185 channel->remote_sig_id = identifier; 1186 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1187 l2cap_run(); 1188 } 1189 1190 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 1191 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1192 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1193 signaling_responses[signaling_responses_pending].handle = handle; 1194 signaling_responses[signaling_responses_pending].code = code; 1195 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1196 signaling_responses[signaling_responses_pending].data = data; 1197 signaling_responses_pending++; 1198 l2cap_run(); 1199 } 1200 } 1201 1202 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1203 1204 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1205 l2cap_service_t *service = l2cap_get_service(psm); 1206 if (!service) { 1207 // 0x0002 PSM not supported 1208 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 1209 return; 1210 } 1211 1212 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1213 if (!hci_connection) { 1214 // 1215 log_error("no hci_connection for handle %u", handle); 1216 return; 1217 } 1218 1219 // alloc structure 1220 // log_info("l2cap_handle_connection_request register channel"); 1221 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 1222 psm, service->mtu, service->required_security_level); 1223 if (!channel){ 1224 // 0x0004 No resources available 1225 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 1226 return; 1227 } 1228 1229 channel->con_handle = handle; 1230 channel->remote_cid = source_cid; 1231 channel->remote_sig_id = sig_id; 1232 1233 // limit local mtu to max acl packet length - l2cap header 1234 if (channel->local_mtu > l2cap_max_mtu()) { 1235 channel->local_mtu = l2cap_max_mtu(); 1236 } 1237 1238 // set initial state 1239 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1240 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 1241 1242 // add to connections list 1243 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1244 1245 // assert security requirements 1246 gap_request_security_level(handle, channel->required_security_level); 1247 } 1248 1249 void l2cap_accept_connection(uint16_t local_cid){ 1250 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1251 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1252 if (!channel) { 1253 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1254 return; 1255 } 1256 1257 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1258 1259 // process 1260 l2cap_run(); 1261 } 1262 1263 void l2cap_decline_connection(uint16_t local_cid){ 1264 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 1265 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1266 if (!channel) { 1267 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1268 return; 1269 } 1270 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1271 channel->reason = 0x04; // no resources available 1272 l2cap_run(); 1273 } 1274 1275 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1276 1277 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1278 1279 uint16_t flags = little_endian_read_16(command, 6); 1280 if (flags & 1) { 1281 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1282 } 1283 1284 // accept the other's configuration options 1285 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1286 uint16_t pos = 8; 1287 while (pos < end_pos){ 1288 uint8_t option_hint = command[pos] >> 7; 1289 uint8_t option_type = command[pos] & 0x7f; 1290 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1291 pos++; 1292 uint8_t length = command[pos++]; 1293 // MTU { type(8): 1, len(8):2, MTU(16) } 1294 if (option_type == 1 && length == 2){ 1295 channel->remote_mtu = little_endian_read_16(command, pos); 1296 // log_info("l2cap cid 0x%02x, remote mtu %u", channel->local_cid, channel->remote_mtu); 1297 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1298 } 1299 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1300 if (option_type == 2 && length == 2){ 1301 channel->flush_timeout = little_endian_read_16(command, pos); 1302 } 1303 // check for unknown options 1304 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1305 log_info("l2cap cid %u, unknown options", channel->local_cid); 1306 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1307 } 1308 pos += length; 1309 } 1310 } 1311 1312 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1313 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1314 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1315 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1316 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 1317 if (channel->state == L2CAP_STATE_OPEN) return 0; 1318 return 1; 1319 } 1320 1321 1322 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1323 1324 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1325 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1326 uint16_t result = 0; 1327 1328 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1329 1330 // handle DISCONNECT REQUESTS seperately 1331 if (code == DISCONNECTION_REQUEST){ 1332 switch (channel->state){ 1333 case L2CAP_STATE_CONFIG: 1334 case L2CAP_STATE_OPEN: 1335 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1336 case L2CAP_STATE_WAIT_DISCONNECT: 1337 l2cap_handle_disconnect_request(channel, identifier); 1338 break; 1339 1340 default: 1341 // ignore in other states 1342 break; 1343 } 1344 return; 1345 } 1346 1347 // @STATEMACHINE(l2cap) 1348 switch (channel->state) { 1349 1350 case L2CAP_STATE_WAIT_CONNECT_RSP: 1351 switch (code){ 1352 case CONNECTION_RESPONSE: 1353 l2cap_stop_rtx(channel); 1354 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1355 switch (result) { 1356 case 0: 1357 // successful connection 1358 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1359 channel->state = L2CAP_STATE_CONFIG; 1360 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1361 break; 1362 case 1: 1363 // connection pending. get some coffee, but start the ERTX 1364 l2cap_start_ertx(channel); 1365 break; 1366 default: 1367 // channel closed 1368 channel->state = L2CAP_STATE_CLOSED; 1369 // map l2cap connection response result to BTstack status enumeration 1370 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1371 1372 // drop link key if security block 1373 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1374 gap_drop_link_key_for_bd_addr(channel->address); 1375 } 1376 1377 // discard channel 1378 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1379 btstack_memory_l2cap_channel_free(channel); 1380 break; 1381 } 1382 break; 1383 1384 default: 1385 //@TODO: implement other signaling packets 1386 break; 1387 } 1388 break; 1389 1390 case L2CAP_STATE_CONFIG: 1391 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1392 switch (code) { 1393 case CONFIGURE_REQUEST: 1394 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1395 l2cap_signaling_handle_configure_request(channel, command); 1396 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1397 // only done if continuation not set 1398 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1399 } 1400 break; 1401 case CONFIGURE_RESPONSE: 1402 l2cap_stop_rtx(channel); 1403 switch (result){ 1404 case 0: // success 1405 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1406 break; 1407 case 4: // pending 1408 l2cap_start_ertx(channel); 1409 break; 1410 default: 1411 // retry on negative result 1412 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1413 break; 1414 } 1415 break; 1416 default: 1417 break; 1418 } 1419 if (l2cap_channel_ready_for_open(channel)){ 1420 // for open: 1421 channel->state = L2CAP_STATE_OPEN; 1422 l2cap_emit_channel_opened(channel, 0); 1423 } 1424 break; 1425 1426 case L2CAP_STATE_WAIT_DISCONNECT: 1427 switch (code) { 1428 case DISCONNECTION_RESPONSE: 1429 l2cap_finialize_channel_close(channel); 1430 break; 1431 default: 1432 //@TODO: implement other signaling packets 1433 break; 1434 } 1435 break; 1436 1437 case L2CAP_STATE_CLOSED: 1438 // @TODO handle incoming requests 1439 break; 1440 1441 case L2CAP_STATE_OPEN: 1442 //@TODO: implement other signaling packets, e.g. re-configure 1443 break; 1444 default: 1445 break; 1446 } 1447 // log_info("new state %u", channel->state); 1448 } 1449 1450 1451 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1452 1453 // get code, signalind identifier and command len 1454 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1455 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1456 1457 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1458 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1459 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1460 return; 1461 } 1462 1463 // general commands without an assigned channel 1464 switch(code) { 1465 1466 case CONNECTION_REQUEST: { 1467 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1468 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1469 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1470 return; 1471 } 1472 1473 case ECHO_REQUEST: 1474 l2cap_register_signaling_response(handle, code, sig_id, 0); 1475 return; 1476 1477 case INFORMATION_REQUEST: { 1478 uint16_t infoType = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1479 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1480 return; 1481 } 1482 1483 default: 1484 break; 1485 } 1486 1487 1488 // Get potential destination CID 1489 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1490 1491 // Find channel for this sig_id and connection handle 1492 btstack_linked_list_iterator_t it; 1493 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1494 while (btstack_linked_list_iterator_has_next(&it)){ 1495 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1496 if (channel->con_handle != handle) continue; 1497 if (code & 1) { 1498 // match odd commands (responses) by previous signaling identifier 1499 if (channel->local_sig_id == sig_id) { 1500 l2cap_signaling_handler_channel(channel, command); 1501 break; 1502 } 1503 } else { 1504 // match even commands (requests) by local channel id 1505 if (channel->local_cid == dest_cid) { 1506 l2cap_signaling_handler_channel(channel, command); 1507 break; 1508 } 1509 } 1510 } 1511 } 1512 1513 #ifdef ENABLE_BLE 1514 // @returns valid 1515 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 1516 hci_connection_t * connection; 1517 uint16_t result; 1518 uint8_t event[10]; 1519 uint16_t le_psm; 1520 uint16_t local_cid; 1521 uint16_t new_credits; 1522 uint16_t credits_before; 1523 l2cap_service_t * service; 1524 l2cap_channel_t * channel; 1525 btstack_linked_list_iterator_t it; 1526 1527 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1528 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 1529 1530 switch (code){ 1531 1532 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 1533 result = little_endian_read_16(command, 4); 1534 l2cap_emit_connection_parameter_update_response(handle, result); 1535 break; 1536 1537 case CONNECTION_PARAMETER_UPDATE_REQUEST: 1538 connection = hci_connection_for_handle(handle); 1539 if (connection){ 1540 if (connection->role != HCI_ROLE_MASTER){ 1541 // reject command without notifying upper layer when not in master role 1542 return 0; 1543 } 1544 int update_parameter = 1; 1545 le_connection_parameter_range_t existing_range; 1546 gap_get_connection_parameter_range(&existing_range); 1547 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 1548 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 1549 uint16_t le_conn_latency = little_endian_read_16(command,12); 1550 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 1551 1552 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 1553 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 1554 1555 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 1556 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 1557 1558 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 1559 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 1560 1561 if (update_parameter){ 1562 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 1563 connection->le_conn_interval_min = le_conn_interval_min; 1564 connection->le_conn_interval_max = le_conn_interval_max; 1565 connection->le_conn_latency = le_conn_latency; 1566 connection->le_supervision_timeout = le_supervision_timeout; 1567 } else { 1568 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 1569 } 1570 connection->le_con_param_update_identifier = sig_id; 1571 } 1572 1573 if (!l2cap_event_packet_handler) break; 1574 1575 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 1576 event[1] = 8; 1577 memcpy(&event[2], &command[4], 8); 1578 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1579 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1580 break; 1581 1582 case COMMAND_REJECT: 1583 // Find channel for this sig_id and connection handle 1584 channel = NULL; 1585 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1586 while (btstack_linked_list_iterator_has_next(&it)){ 1587 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1588 if (a_channel->con_handle != handle) continue; 1589 if (a_channel->local_sig_id != sig_id) continue; 1590 channel = a_channel; 1591 break; 1592 } 1593 if (!channel) break; 1594 1595 // if received while waiting for le connection response, assume legacy device 1596 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 1597 channel->state = L2CAP_STATE_CLOSED; 1598 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 1599 l2cap_emit_channel_opened(channel, 0x0002); 1600 1601 // discard channel 1602 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1603 btstack_memory_l2cap_channel_free(channel); 1604 break; 1605 } 1606 break; 1607 1608 case LE_CREDIT_BASED_CONNECTION_REQUEST: 1609 1610 // get hci connection, bail if not found (must not happen) 1611 connection = hci_connection_for_handle(handle); 1612 if (!connection) return 0; 1613 1614 // check if service registered 1615 le_psm = little_endian_read_16(command, 4); 1616 service = l2cap_le_get_service(le_psm); 1617 1618 if (service){ 1619 1620 uint16_t source_cid = little_endian_read_16(command, 6); 1621 if (source_cid < 0x40){ 1622 // 0x0009 Connection refused - Invalid Source CID 1623 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0009); 1624 return 1; 1625 } 1626 1627 // go through list of channels for this ACL connection and check if we get a match 1628 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1629 while (btstack_linked_list_iterator_has_next(&it)){ 1630 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1631 if (a_channel->con_handle != handle) continue; 1632 if (a_channel->remote_cid != source_cid) continue; 1633 // 0x000a Connection refused - Source CID already allocated 1634 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x000a); 1635 return 1; 1636 } 1637 1638 // TODO: deal with authentication requirements, errors 0x005 - 000x8 1639 1640 // allocate channel 1641 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 1642 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 1643 if (!channel){ 1644 // 0x0004 Connection refused – no resources available 1645 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0004); 1646 return 1; 1647 } 1648 1649 channel->con_handle = handle; 1650 channel->remote_cid = source_cid; 1651 channel->remote_sig_id = sig_id; 1652 channel->remote_mtu = little_endian_read_16(command, 8); 1653 channel->remote_mps = little_endian_read_16(command, 10); 1654 channel->credits_outgoing = little_endian_read_16(command, 12); 1655 1656 // set initial state 1657 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1658 1659 // add to connections list 1660 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1661 1662 // post connection request event 1663 l2cap_emit_connection_request(channel); 1664 1665 } else { 1666 // Connection refused – LE_PSM not supported 1667 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0002); 1668 } 1669 break; 1670 1671 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 1672 // Find channel for this sig_id and connection handle 1673 channel = NULL; 1674 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1675 while (btstack_linked_list_iterator_has_next(&it)){ 1676 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1677 if (a_channel->con_handle != handle) continue; 1678 if (a_channel->local_sig_id != sig_id) continue; 1679 channel = a_channel; 1680 break; 1681 } 1682 if (!channel) break; 1683 1684 // cid + 0 1685 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 1686 if (result){ 1687 channel->state = L2CAP_STATE_CLOSED; 1688 // map l2cap connection response result to BTstack status enumeration 1689 l2cap_emit_channel_opened(channel, result); 1690 1691 // discard channel 1692 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1693 btstack_memory_l2cap_channel_free(channel); 1694 break; 1695 } 1696 1697 // success 1698 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1699 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1700 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 1701 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 1702 channel->state = L2CAP_STATE_OPEN; 1703 l2cap_emit_channel_opened(channel, result); 1704 break; 1705 1706 case LE_FLOW_CONTROL_CREDIT: 1707 // find channel 1708 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1709 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1710 if (!channel) { 1711 log_error("l2cap: no channel for cid 0x%02x", local_cid); 1712 break; 1713 } 1714 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1715 credits_before = channel->credits_outgoing; 1716 channel->credits_outgoing += new_credits; 1717 // check for credit overrun 1718 if (credits_before > channel->credits_outgoing){ 1719 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 1720 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1721 break; 1722 } 1723 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 1724 break; 1725 1726 case DISCONNECTION_REQUEST: 1727 // find channel 1728 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1729 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1730 if (!channel) { 1731 log_error("l2cap: no channel for cid 0x%02x", local_cid); 1732 break; 1733 } 1734 channel->remote_sig_id = sig_id; 1735 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1736 break; 1737 1738 case DISCONNECTION_RESPONSE: 1739 break; 1740 1741 default: 1742 // command unknown -> reject command 1743 return 0; 1744 } 1745 return 1; 1746 } 1747 #endif 1748 1749 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 1750 1751 // Get Channel ID 1752 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1753 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1754 1755 switch (channel_id) { 1756 1757 case L2CAP_CID_SIGNALING: { 1758 uint16_t command_offset = 8; 1759 while (command_offset < size) { 1760 // handle signaling commands 1761 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1762 1763 // increment command_offset 1764 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1765 } 1766 break; 1767 } 1768 1769 #ifdef ENABLE_BLE 1770 case L2CAP_CID_SIGNALING_LE: { 1771 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1772 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 1773 if (!valid){ 1774 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1775 } 1776 break; 1777 } 1778 #endif 1779 1780 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1781 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 1782 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1783 } 1784 break; 1785 1786 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1787 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 1788 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1789 } 1790 break; 1791 1792 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 1793 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 1794 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1795 } 1796 break; 1797 1798 default: { 1799 // Find channel for this channel_id and connection handle 1800 l2cap_channel_t * l2cap_channel; 1801 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 1802 if (l2cap_channel) { 1803 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1804 } 1805 #ifdef ENABLE_BLE 1806 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 1807 if (l2cap_channel) { 1808 // credit counting 1809 if (l2cap_channel->credits_incoming == 0){ 1810 log_error("LE Data Channel packet received but no incoming credits"); 1811 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1812 break; 1813 } 1814 l2cap_channel->credits_incoming--; 1815 1816 // automatic credits 1817 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 1818 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 1819 } 1820 1821 // first fragment 1822 uint16_t pos = 0; 1823 if (!l2cap_channel->receive_sdu_len){ 1824 l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 1825 l2cap_channel->receive_sdu_pos = 0; 1826 pos += 2; 1827 size -= 2; 1828 } 1829 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); 1830 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 1831 // done? 1832 log_info("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 1833 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 1834 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 1835 l2cap_channel->receive_sdu_len = 0; 1836 } 1837 } else { 1838 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 1839 } 1840 #endif 1841 break; 1842 } 1843 } 1844 1845 l2cap_run(); 1846 } 1847 1848 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1849 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 1850 channel->state = L2CAP_STATE_CLOSED; 1851 l2cap_emit_channel_closed(channel); 1852 // discard channel 1853 l2cap_stop_rtx(channel); 1854 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1855 btstack_memory_l2cap_channel_free(channel); 1856 } 1857 1858 #ifdef ENABLE_BLE 1859 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1860 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 1861 channel->state = L2CAP_STATE_CLOSED; 1862 l2cap_emit_channel_closed(channel); 1863 // discard channel 1864 l2cap_stop_rtx(channel); 1865 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1866 btstack_memory_l2cap_channel_free(channel); 1867 } 1868 #endif 1869 1870 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 1871 btstack_linked_list_iterator_t it; 1872 btstack_linked_list_iterator_init(&it, services); 1873 while (btstack_linked_list_iterator_has_next(&it)){ 1874 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 1875 if ( service->psm == psm){ 1876 return service; 1877 }; 1878 } 1879 return NULL; 1880 } 1881 1882 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 1883 return l2cap_get_service_internal(&l2cap_services, psm); 1884 } 1885 1886 1887 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 1888 1889 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1890 1891 // check for alread registered psm 1892 l2cap_service_t *service = l2cap_get_service(psm); 1893 if (service) { 1894 log_error("l2cap_register_service: PSM %u already registered", psm); 1895 return L2CAP_SERVICE_ALREADY_REGISTERED; 1896 } 1897 1898 // alloc structure 1899 service = btstack_memory_l2cap_service_get(); 1900 if (!service) { 1901 log_error("l2cap_register_service: no memory for l2cap_service_t"); 1902 return BTSTACK_MEMORY_ALLOC_FAILED; 1903 } 1904 1905 // fill in 1906 service->psm = psm; 1907 service->mtu = mtu; 1908 service->packet_handler = service_packet_handler; 1909 service->required_security_level = security_level; 1910 1911 // add to services list 1912 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 1913 1914 // enable page scan 1915 gap_connectable_control(1); 1916 1917 return 0; 1918 } 1919 1920 uint8_t l2cap_unregister_service(uint16_t psm){ 1921 1922 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1923 1924 l2cap_service_t *service = l2cap_get_service(psm); 1925 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 1926 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 1927 btstack_memory_l2cap_service_free(service); 1928 1929 // disable page scan when no services registered 1930 if (btstack_linked_list_empty(&l2cap_services)) { 1931 gap_connectable_control(0); 1932 } 1933 return 0; 1934 } 1935 1936 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1937 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 1938 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 1939 if (index < 0) return; 1940 fixed_channels[index].callback = the_packet_handler; 1941 } 1942 1943 #ifdef ENABLE_BLE 1944 1945 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 1946 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 1947 } 1948 1949 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 1950 1951 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 1952 1953 // check for alread registered psm 1954 l2cap_service_t *service = l2cap_le_get_service(psm); 1955 if (service) { 1956 return L2CAP_SERVICE_ALREADY_REGISTERED; 1957 } 1958 1959 // alloc structure 1960 service = btstack_memory_l2cap_service_get(); 1961 if (!service) { 1962 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 1963 return BTSTACK_MEMORY_ALLOC_FAILED; 1964 } 1965 1966 // fill in 1967 service->psm = psm; 1968 service->mtu = 0; 1969 service->packet_handler = packet_handler; 1970 service->required_security_level = security_level; 1971 1972 // add to services list 1973 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 1974 1975 // done 1976 return 0; 1977 } 1978 1979 uint8_t l2cap_le_unregister_service(uint16_t psm) { 1980 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 1981 l2cap_service_t *service = l2cap_le_get_service(psm); 1982 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 1983 1984 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 1985 btstack_memory_l2cap_service_free(service); 1986 return 0; 1987 } 1988 1989 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 1990 // get channel 1991 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 1992 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 1993 1994 // validate state 1995 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 1996 return ERROR_CODE_COMMAND_DISALLOWED; 1997 } 1998 1999 // set state accept connection 2000 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 2001 channel->receive_sdu_buffer = receive_sdu_buffer; 2002 channel->local_mtu = mtu; 2003 channel->new_credits_incoming = initial_credits; 2004 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2005 2006 // test 2007 // channel->new_credits_incoming = 1; 2008 2009 // go 2010 l2cap_run(); 2011 return 0; 2012 } 2013 2014 /** 2015 * @brief Deny incoming LE Data Channel connection due to resource constraints 2016 * @param local_cid L2CAP LE Data Channel Identifier 2017 */ 2018 2019 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 2020 // get channel 2021 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2022 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2023 2024 // validate state 2025 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2026 return ERROR_CODE_COMMAND_DISALLOWED; 2027 } 2028 2029 // set state decline connection 2030 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 2031 channel->reason = 0x04; // no resources available 2032 l2cap_run(); 2033 return 0; 2034 } 2035 2036 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 2037 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 2038 uint16_t * out_local_cid) { 2039 2040 log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 2041 2042 2043 hci_connection_t * connection = hci_connection_for_handle(con_handle); 2044 if (!connection) { 2045 log_error("no hci_connection for handle 0x%04x", con_handle); 2046 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 2047 } 2048 2049 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, connection->address, connection->address_type, psm, mtu, security_level); 2050 if (!channel) { 2051 return BTSTACK_MEMORY_ALLOC_FAILED; 2052 } 2053 log_info("l2cap_le_create_channel %p", channel); 2054 2055 // store local_cid 2056 if (out_local_cid){ 2057 *out_local_cid = channel->local_cid; 2058 } 2059 2060 // provide buffer 2061 channel->con_handle = con_handle; 2062 channel->receive_sdu_buffer = receive_sdu_buffer; 2063 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 2064 channel->new_credits_incoming = initial_credits; 2065 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2066 2067 // add to connections list 2068 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2069 2070 // go 2071 l2cap_run(); 2072 return 0; 2073 } 2074 2075 /** 2076 * @brief Provide credtis for LE Data Channel 2077 * @param local_cid L2CAP LE Data Channel Identifier 2078 * @param credits Number additional credits for peer 2079 */ 2080 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 2081 2082 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2083 if (!channel) { 2084 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2085 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2086 } 2087 2088 // check state 2089 if (channel->state != L2CAP_STATE_OPEN){ 2090 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 2091 } 2092 2093 // assert incoming credits + credits <= 0xffff 2094 uint32_t total_credits = channel->credits_incoming; 2095 total_credits += channel->new_credits_incoming; 2096 total_credits += credits; 2097 if (total_credits > 0xffff){ 2098 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 2099 channel->new_credits_incoming, credits); 2100 } 2101 2102 // set credits_granted 2103 channel->new_credits_incoming += credits; 2104 2105 // go 2106 l2cap_run(); 2107 return 0; 2108 } 2109 2110 /** 2111 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 2112 * @param local_cid L2CAP LE Data Channel Identifier 2113 */ 2114 int l2cap_le_can_send_now(uint16_t local_cid){ 2115 // check if data can be sent via le at all 2116 return 0; 2117 } 2118 2119 /** 2120 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 2121 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 2122 * so packet handler should be ready to handle it 2123 * @param local_cid L2CAP LE Data Channel Identifier 2124 */ 2125 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 2126 // same as for non-le 2127 return 0; 2128 } 2129 2130 /** 2131 * @brief Send data via LE Data Channel 2132 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 2133 * @param local_cid L2CAP LE Data Channel Identifier 2134 * @param data data to send 2135 * @param size data size 2136 */ 2137 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 2138 2139 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2140 if (!channel) { 2141 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2142 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2143 } 2144 2145 if (len > channel->remote_mtu){ 2146 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 2147 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 2148 } 2149 2150 if (channel->send_sdu_buffer){ 2151 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 2152 return BTSTACK_ACL_BUFFERS_FULL; 2153 } 2154 2155 channel->send_sdu_buffer = data; 2156 channel->send_sdu_len = len; 2157 channel->send_sdu_pos = 0; 2158 2159 l2cap_run(); 2160 return 0; 2161 } 2162 2163 /** 2164 * @brief Disconnect from LE Data Channel 2165 * @param local_cid L2CAP LE Data Channel Identifier 2166 */ 2167 uint8_t l2cap_le_disconnect(uint16_t local_cid) 2168 { 2169 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2170 if (!channel) { 2171 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2172 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2173 } 2174 2175 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2176 l2cap_run(); 2177 return 0; 2178 } 2179 2180 #endif 2181