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_CHANNELS 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_LE_DATA_CHANNELS 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 #ifdef ENABLE_LE_DATA_CHANNELS 733 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 734 while (btstack_linked_list_iterator_has_next(&it)){ 735 uint8_t * acl_buffer; 736 uint8_t * l2cap_payload; 737 uint16_t pos; 738 uint16_t payload_size; 739 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 740 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 741 switch (channel->state){ 742 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 743 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 744 channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; 745 // le psm, source cid, mtu, mps, initial credits 746 channel->local_sig_id = l2cap_next_sig_id(); 747 channel->credits_incoming = channel->new_credits_incoming; 748 channel->new_credits_incoming = 0; 749 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); 750 break; 751 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 752 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 753 // TODO: support larger MPS 754 channel->state = L2CAP_STATE_OPEN; 755 channel->credits_incoming = channel->new_credits_incoming; 756 channel->new_credits_incoming = 0; 757 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); 758 // notify client 759 l2cap_emit_channel_opened(channel, 0); 760 break; 761 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 762 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 763 channel->state = L2CAP_STATE_INVALID; 764 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, 0, 0, channel->reason); 765 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 766 l2cap_stop_rtx(channel); 767 btstack_linked_list_iterator_remove(&it); 768 btstack_memory_l2cap_channel_free(channel); 769 break; 770 case L2CAP_STATE_OPEN: 771 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 772 773 // send credits 774 if (channel->new_credits_incoming){ 775 log_info("l2cap: sending %u credits", channel->new_credits_incoming); 776 channel->local_sig_id = l2cap_next_sig_id(); 777 uint16_t new_credits = channel->new_credits_incoming; 778 channel->new_credits_incoming = 0; 779 channel->credits_incoming += new_credits; 780 l2cap_send_le_signaling_packet(channel->con_handle, LE_FLOW_CONTROL_CREDIT, channel->local_sig_id, channel->remote_cid, new_credits); 781 break; 782 } 783 784 // send data 785 if (!channel->send_sdu_buffer) break; 786 if (!channel->credits_outgoing) break; 787 788 // send part of SDU 789 hci_reserve_packet_buffer(); 790 acl_buffer = hci_get_outgoing_packet_buffer(); 791 l2cap_payload = acl_buffer + 8; 792 pos = 0; 793 if (!channel->send_sdu_pos){ 794 // store SDU len 795 channel->send_sdu_pos += 2; 796 little_endian_store_16(l2cap_payload, pos, channel->send_sdu_len); 797 pos += 2; 798 } 799 payload_size = btstack_min(channel->send_sdu_len + 2 - channel->send_sdu_pos, channel->remote_mps - pos); 800 log_info("len %u, pos %u => payload %u, credits %u", channel->send_sdu_len, channel->send_sdu_pos, payload_size, channel->credits_outgoing); 801 memcpy(&l2cap_payload[pos], &channel->send_sdu_buffer[channel->send_sdu_pos-2], payload_size); // -2 for virtual SDU len 802 pos += payload_size; 803 channel->send_sdu_pos += payload_size; 804 l2cap_setup_header(acl_buffer, channel->con_handle, channel->remote_cid, pos); 805 // done 806 807 channel->credits_outgoing--; 808 809 if (channel->send_sdu_pos >= channel->send_sdu_len + 2){ 810 channel->send_sdu_buffer = NULL; 811 // TODO: send done event 812 } 813 hci_send_acl_packet_buffer(8 + pos); 814 break; 815 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 816 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 817 channel->local_sig_id = l2cap_next_sig_id(); 818 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 819 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 820 break; 821 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 822 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 823 channel->state = L2CAP_STATE_INVALID; 824 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 825 l2cap_le_finialize_channel_close(channel); // -- remove from list 826 break; 827 default: 828 break; 829 } 830 } 831 832 // send l2cap con paramter update if necessary 833 hci_connections_get_iterator(&it); 834 while(btstack_linked_list_iterator_has_next(&it)){ 835 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 836 if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; 837 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 838 switch (connection->le_con_parameter_update_state){ 839 case CON_PARAMETER_UPDATE_SEND_REQUEST: 840 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 841 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, connection->le_con_param_update_identifier, 842 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 843 break; 844 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 845 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 846 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 847 break; 848 case CON_PARAMETER_UPDATE_DENY: 849 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 850 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 851 break; 852 default: 853 break; 854 } 855 } 856 #endif 857 #endif 858 859 // log_info("l2cap_run: exit"); 860 } 861 862 uint16_t l2cap_max_mtu(void){ 863 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 864 } 865 866 uint16_t l2cap_max_le_mtu(void){ 867 return l2cap_max_mtu(); 868 } 869 870 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 871 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 872 log_info("l2cap_handle_connection_complete expected state"); 873 // success, start l2cap handshake 874 channel->con_handle = con_handle; 875 // check remote SSP feature first 876 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 877 } 878 } 879 880 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 881 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 882 883 // we have been waiting for remote supported features, if both support SSP, 884 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)); 885 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 886 // request security level 2 887 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 888 gap_request_security_level(channel->con_handle, LEVEL_2); 889 return; 890 } 891 // fine, go ahead 892 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 893 } 894 895 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 896 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 897 898 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 899 if (!channel) { 900 return NULL; 901 } 902 903 // Init memory (make valgrind happy) 904 memset(channel, 0, sizeof(l2cap_channel_t)); 905 906 // fill in 907 channel->packet_handler = packet_handler; 908 bd_addr_copy(channel->address, address); 909 channel->address_type = address_type; 910 channel->psm = psm; 911 channel->local_mtu = local_mtu; 912 channel->remote_mtu = L2CAP_MINIMAL_MTU; 913 channel->required_security_level = security_level; 914 915 // 916 channel->local_cid = l2cap_next_local_cid(); 917 channel->con_handle = 0; 918 919 // set initial state 920 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 921 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 922 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 923 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 924 return channel; 925 } 926 927 /** 928 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 929 * @param packet_handler 930 * @param address 931 * @param psm 932 * @param mtu 933 * @param local_cid 934 */ 935 936 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){ 937 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, local_mtu); 938 939 if (local_mtu > l2cap_max_mtu()) { 940 local_mtu = l2cap_max_mtu(); 941 } 942 943 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 944 if (!channel) { 945 return BTSTACK_MEMORY_ALLOC_FAILED; 946 } 947 948 // add to connections list 949 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 950 951 // store local_cid 952 if (out_local_cid){ 953 *out_local_cid = channel->local_cid; 954 } 955 956 // check if hci connection is already usable 957 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 958 if (conn){ 959 log_info("l2cap_create_channel, hci connection already exists"); 960 l2cap_handle_connection_complete(conn->con_handle, channel); 961 // check if remote supported fearures are already received 962 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 963 l2cap_handle_remote_supported_features_received(channel); 964 } 965 } 966 967 l2cap_run(); 968 969 return 0; 970 } 971 972 void 973 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 974 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 975 // find channel for local_cid 976 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 977 if (channel) { 978 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 979 } 980 // process 981 l2cap_run(); 982 } 983 984 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 985 btstack_linked_list_iterator_t it; 986 btstack_linked_list_iterator_init(&it, &l2cap_channels); 987 while (btstack_linked_list_iterator_has_next(&it)){ 988 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 989 if ( bd_addr_cmp( channel->address, address) != 0) continue; 990 // channel for this address found 991 switch (channel->state){ 992 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 993 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 994 // failure, forward error code 995 l2cap_emit_channel_opened(channel, status); 996 // discard channel 997 l2cap_stop_rtx(channel); 998 btstack_linked_list_iterator_remove(&it); 999 btstack_memory_l2cap_channel_free(channel); 1000 break; 1001 default: 1002 break; 1003 } 1004 } 1005 } 1006 1007 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1008 btstack_linked_list_iterator_t it; 1009 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1010 while (btstack_linked_list_iterator_has_next(&it)){ 1011 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1012 if ( ! bd_addr_cmp( channel->address, address) ){ 1013 l2cap_handle_connection_complete(handle, channel); 1014 } 1015 } 1016 // process 1017 l2cap_run(); 1018 } 1019 1020 static void l2cap_notify_channel_can_send(void){ 1021 btstack_linked_list_iterator_t it; 1022 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1023 while (btstack_linked_list_iterator_has_next(&it)){ 1024 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1025 if (!channel->waiting_for_can_send_now) continue; 1026 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1027 channel->waiting_for_can_send_now = 0; 1028 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1029 } 1030 1031 int i; 1032 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1033 if (!fixed_channels[i].callback) continue; 1034 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1035 int can_send; 1036 if (l2cap_fixed_channel_table_index_is_le(i)){ 1037 can_send = hci_can_send_acl_le_packet_now(); 1038 } else { 1039 can_send = hci_can_send_acl_classic_packet_now(); 1040 } 1041 if (!can_send) continue; 1042 fixed_channels[i].waiting_for_can_send_now = 0; 1043 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1044 } 1045 } 1046 1047 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1048 1049 bd_addr_t address; 1050 hci_con_handle_t handle; 1051 btstack_linked_list_iterator_t it; 1052 int hci_con_used; 1053 1054 switch(hci_event_packet_get_type(packet)){ 1055 1056 // handle connection complete events 1057 case HCI_EVENT_CONNECTION_COMPLETE: 1058 reverse_bd_addr(&packet[5], address); 1059 if (packet[2] == 0){ 1060 handle = little_endian_read_16(packet, 3); 1061 l2cap_handle_connection_success_for_addr(address, handle); 1062 } else { 1063 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1064 } 1065 break; 1066 1067 // handle successful create connection cancel command 1068 case HCI_EVENT_COMMAND_COMPLETE: 1069 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1070 if (packet[5] == 0){ 1071 reverse_bd_addr(&packet[6], address); 1072 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1073 l2cap_handle_connection_failed_for_addr(address, 0x16); 1074 } 1075 } 1076 l2cap_run(); // try sending signaling packets first 1077 break; 1078 1079 case HCI_EVENT_COMMAND_STATUS: 1080 l2cap_run(); // try sending signaling packets first 1081 break; 1082 1083 // handle disconnection complete events 1084 case HCI_EVENT_DISCONNECTION_COMPLETE: 1085 // send l2cap disconnect events for all channels on this handle and free them 1086 handle = little_endian_read_16(packet, 3); 1087 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1088 while (btstack_linked_list_iterator_has_next(&it)){ 1089 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1090 if (channel->con_handle != handle) continue; 1091 l2cap_emit_channel_closed(channel); 1092 l2cap_stop_rtx(channel); 1093 btstack_linked_list_iterator_remove(&it); 1094 btstack_memory_l2cap_channel_free(channel); 1095 } 1096 #ifdef ENABLE_BLE 1097 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1098 while (btstack_linked_list_iterator_has_next(&it)){ 1099 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1100 if (channel->con_handle != handle) continue; 1101 l2cap_emit_channel_closed(channel); 1102 btstack_linked_list_iterator_remove(&it); 1103 btstack_memory_l2cap_channel_free(channel); 1104 } 1105 #endif 1106 break; 1107 1108 // Notify channel packet handler if they can send now 1109 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1110 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1111 l2cap_run(); // try sending signaling packets first 1112 l2cap_notify_channel_can_send(); 1113 break; 1114 1115 // HCI Connection Timeouts 1116 case L2CAP_EVENT_TIMEOUT_CHECK: 1117 handle = little_endian_read_16(packet, 2); 1118 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1119 if (hci_authentication_active_for_handle(handle)) break; 1120 hci_con_used = 0; 1121 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1122 while (btstack_linked_list_iterator_has_next(&it)){ 1123 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1124 if (channel->con_handle != handle) continue; 1125 hci_con_used = 1; 1126 break; 1127 } 1128 if (hci_con_used) break; 1129 if (!hci_can_send_command_packet_now()) break; 1130 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1131 break; 1132 1133 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1134 handle = little_endian_read_16(packet, 3); 1135 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1136 while (btstack_linked_list_iterator_has_next(&it)){ 1137 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1138 if (channel->con_handle != handle) continue; 1139 l2cap_handle_remote_supported_features_received(channel); 1140 break; 1141 } 1142 break; 1143 1144 case GAP_EVENT_SECURITY_LEVEL: 1145 handle = little_endian_read_16(packet, 2); 1146 log_info("l2cap - security level update"); 1147 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1148 while (btstack_linked_list_iterator_has_next(&it)){ 1149 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1150 if (channel->con_handle != handle) continue; 1151 1152 log_info("l2cap - state %u", channel->state); 1153 1154 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1155 gap_security_level_t required_level = channel->required_security_level; 1156 1157 switch (channel->state){ 1158 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1159 if (actual_level >= required_level){ 1160 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1161 l2cap_emit_connection_request(channel); 1162 } else { 1163 channel->reason = 0x0003; // security block 1164 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1165 } 1166 break; 1167 1168 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1169 if (actual_level >= required_level){ 1170 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1171 } else { 1172 // disconnnect, authentication not good enough 1173 hci_disconnect_security_block(handle); 1174 } 1175 break; 1176 1177 default: 1178 break; 1179 } 1180 } 1181 break; 1182 1183 default: 1184 break; 1185 } 1186 1187 l2cap_run(); 1188 } 1189 1190 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1191 channel->remote_sig_id = identifier; 1192 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1193 l2cap_run(); 1194 } 1195 1196 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 1197 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1198 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1199 signaling_responses[signaling_responses_pending].handle = handle; 1200 signaling_responses[signaling_responses_pending].code = code; 1201 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1202 signaling_responses[signaling_responses_pending].data = data; 1203 signaling_responses_pending++; 1204 l2cap_run(); 1205 } 1206 } 1207 1208 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1209 1210 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1211 l2cap_service_t *service = l2cap_get_service(psm); 1212 if (!service) { 1213 // 0x0002 PSM not supported 1214 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 1215 return; 1216 } 1217 1218 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1219 if (!hci_connection) { 1220 // 1221 log_error("no hci_connection for handle %u", handle); 1222 return; 1223 } 1224 1225 // alloc structure 1226 // log_info("l2cap_handle_connection_request register channel"); 1227 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 1228 psm, service->mtu, service->required_security_level); 1229 if (!channel){ 1230 // 0x0004 No resources available 1231 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 1232 return; 1233 } 1234 1235 channel->con_handle = handle; 1236 channel->remote_cid = source_cid; 1237 channel->remote_sig_id = sig_id; 1238 1239 // limit local mtu to max acl packet length - l2cap header 1240 if (channel->local_mtu > l2cap_max_mtu()) { 1241 channel->local_mtu = l2cap_max_mtu(); 1242 } 1243 1244 // set initial state 1245 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1246 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 1247 1248 // add to connections list 1249 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1250 1251 // assert security requirements 1252 gap_request_security_level(handle, channel->required_security_level); 1253 } 1254 1255 void l2cap_accept_connection(uint16_t local_cid){ 1256 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1257 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1258 if (!channel) { 1259 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1260 return; 1261 } 1262 1263 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1264 1265 // process 1266 l2cap_run(); 1267 } 1268 1269 void l2cap_decline_connection(uint16_t local_cid){ 1270 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 1271 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1272 if (!channel) { 1273 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1274 return; 1275 } 1276 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1277 channel->reason = 0x04; // no resources available 1278 l2cap_run(); 1279 } 1280 1281 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1282 1283 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1284 1285 uint16_t flags = little_endian_read_16(command, 6); 1286 if (flags & 1) { 1287 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1288 } 1289 1290 // accept the other's configuration options 1291 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1292 uint16_t pos = 8; 1293 while (pos < end_pos){ 1294 uint8_t option_hint = command[pos] >> 7; 1295 uint8_t option_type = command[pos] & 0x7f; 1296 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1297 pos++; 1298 uint8_t length = command[pos++]; 1299 // MTU { type(8): 1, len(8):2, MTU(16) } 1300 if (option_type == 1 && length == 2){ 1301 channel->remote_mtu = little_endian_read_16(command, pos); 1302 // log_info("l2cap cid 0x%02x, remote mtu %u", channel->local_cid, channel->remote_mtu); 1303 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1304 } 1305 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1306 if (option_type == 2 && length == 2){ 1307 channel->flush_timeout = little_endian_read_16(command, pos); 1308 } 1309 // check for unknown options 1310 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1311 log_info("l2cap cid %u, unknown options", channel->local_cid); 1312 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1313 } 1314 pos += length; 1315 } 1316 } 1317 1318 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1319 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1320 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1321 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1322 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 1323 if (channel->state == L2CAP_STATE_OPEN) return 0; 1324 return 1; 1325 } 1326 1327 1328 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1329 1330 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1331 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1332 uint16_t result = 0; 1333 1334 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1335 1336 // handle DISCONNECT REQUESTS seperately 1337 if (code == DISCONNECTION_REQUEST){ 1338 switch (channel->state){ 1339 case L2CAP_STATE_CONFIG: 1340 case L2CAP_STATE_OPEN: 1341 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1342 case L2CAP_STATE_WAIT_DISCONNECT: 1343 l2cap_handle_disconnect_request(channel, identifier); 1344 break; 1345 1346 default: 1347 // ignore in other states 1348 break; 1349 } 1350 return; 1351 } 1352 1353 // @STATEMACHINE(l2cap) 1354 switch (channel->state) { 1355 1356 case L2CAP_STATE_WAIT_CONNECT_RSP: 1357 switch (code){ 1358 case CONNECTION_RESPONSE: 1359 l2cap_stop_rtx(channel); 1360 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1361 switch (result) { 1362 case 0: 1363 // successful connection 1364 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1365 channel->state = L2CAP_STATE_CONFIG; 1366 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1367 break; 1368 case 1: 1369 // connection pending. get some coffee, but start the ERTX 1370 l2cap_start_ertx(channel); 1371 break; 1372 default: 1373 // channel closed 1374 channel->state = L2CAP_STATE_CLOSED; 1375 // map l2cap connection response result to BTstack status enumeration 1376 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1377 1378 // drop link key if security block 1379 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1380 gap_drop_link_key_for_bd_addr(channel->address); 1381 } 1382 1383 // discard channel 1384 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1385 btstack_memory_l2cap_channel_free(channel); 1386 break; 1387 } 1388 break; 1389 1390 default: 1391 //@TODO: implement other signaling packets 1392 break; 1393 } 1394 break; 1395 1396 case L2CAP_STATE_CONFIG: 1397 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1398 switch (code) { 1399 case CONFIGURE_REQUEST: 1400 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1401 l2cap_signaling_handle_configure_request(channel, command); 1402 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1403 // only done if continuation not set 1404 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1405 } 1406 break; 1407 case CONFIGURE_RESPONSE: 1408 l2cap_stop_rtx(channel); 1409 switch (result){ 1410 case 0: // success 1411 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1412 break; 1413 case 4: // pending 1414 l2cap_start_ertx(channel); 1415 break; 1416 default: 1417 // retry on negative result 1418 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1419 break; 1420 } 1421 break; 1422 default: 1423 break; 1424 } 1425 if (l2cap_channel_ready_for_open(channel)){ 1426 // for open: 1427 channel->state = L2CAP_STATE_OPEN; 1428 l2cap_emit_channel_opened(channel, 0); 1429 } 1430 break; 1431 1432 case L2CAP_STATE_WAIT_DISCONNECT: 1433 switch (code) { 1434 case DISCONNECTION_RESPONSE: 1435 l2cap_finialize_channel_close(channel); 1436 break; 1437 default: 1438 //@TODO: implement other signaling packets 1439 break; 1440 } 1441 break; 1442 1443 case L2CAP_STATE_CLOSED: 1444 // @TODO handle incoming requests 1445 break; 1446 1447 case L2CAP_STATE_OPEN: 1448 //@TODO: implement other signaling packets, e.g. re-configure 1449 break; 1450 default: 1451 break; 1452 } 1453 // log_info("new state %u", channel->state); 1454 } 1455 1456 1457 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1458 1459 // get code, signalind identifier and command len 1460 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1461 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1462 1463 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1464 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1465 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1466 return; 1467 } 1468 1469 // general commands without an assigned channel 1470 switch(code) { 1471 1472 case CONNECTION_REQUEST: { 1473 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1474 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1475 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1476 return; 1477 } 1478 1479 case ECHO_REQUEST: 1480 l2cap_register_signaling_response(handle, code, sig_id, 0); 1481 return; 1482 1483 case INFORMATION_REQUEST: { 1484 uint16_t infoType = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1485 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1486 return; 1487 } 1488 1489 default: 1490 break; 1491 } 1492 1493 1494 // Get potential destination CID 1495 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1496 1497 // Find channel for this sig_id and connection handle 1498 btstack_linked_list_iterator_t it; 1499 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1500 while (btstack_linked_list_iterator_has_next(&it)){ 1501 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1502 if (channel->con_handle != handle) continue; 1503 if (code & 1) { 1504 // match odd commands (responses) by previous signaling identifier 1505 if (channel->local_sig_id == sig_id) { 1506 l2cap_signaling_handler_channel(channel, command); 1507 break; 1508 } 1509 } else { 1510 // match even commands (requests) by local channel id 1511 if (channel->local_cid == dest_cid) { 1512 l2cap_signaling_handler_channel(channel, command); 1513 break; 1514 } 1515 } 1516 } 1517 } 1518 1519 #ifdef ENABLE_BLE 1520 // @returns valid 1521 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 1522 hci_connection_t * connection; 1523 uint16_t result; 1524 uint8_t event[10]; 1525 uint16_t local_cid; 1526 l2cap_channel_t * channel; 1527 btstack_linked_list_iterator_t it; 1528 1529 #ifdef ENABLE_LE_DATA_CHANNELS 1530 uint16_t le_psm; 1531 uint16_t new_credits; 1532 uint16_t credits_before; 1533 l2cap_service_t * service; 1534 #endif 1535 1536 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1537 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 1538 1539 switch (code){ 1540 1541 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 1542 result = little_endian_read_16(command, 4); 1543 l2cap_emit_connection_parameter_update_response(handle, result); 1544 break; 1545 1546 case CONNECTION_PARAMETER_UPDATE_REQUEST: 1547 connection = hci_connection_for_handle(handle); 1548 if (connection){ 1549 if (connection->role != HCI_ROLE_MASTER){ 1550 // reject command without notifying upper layer when not in master role 1551 return 0; 1552 } 1553 int update_parameter = 1; 1554 le_connection_parameter_range_t existing_range; 1555 gap_get_connection_parameter_range(&existing_range); 1556 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 1557 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 1558 uint16_t le_conn_latency = little_endian_read_16(command,12); 1559 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 1560 1561 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 1562 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 1563 1564 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 1565 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 1566 1567 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 1568 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 1569 1570 if (update_parameter){ 1571 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 1572 connection->le_conn_interval_min = le_conn_interval_min; 1573 connection->le_conn_interval_max = le_conn_interval_max; 1574 connection->le_conn_latency = le_conn_latency; 1575 connection->le_supervision_timeout = le_supervision_timeout; 1576 } else { 1577 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 1578 } 1579 connection->le_con_param_update_identifier = sig_id; 1580 } 1581 1582 if (!l2cap_event_packet_handler) break; 1583 1584 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 1585 event[1] = 8; 1586 memcpy(&event[2], &command[4], 8); 1587 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1588 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1589 break; 1590 1591 case COMMAND_REJECT: 1592 // Find channel for this sig_id and connection handle 1593 channel = NULL; 1594 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1595 while (btstack_linked_list_iterator_has_next(&it)){ 1596 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1597 if (a_channel->con_handle != handle) continue; 1598 if (a_channel->local_sig_id != sig_id) continue; 1599 channel = a_channel; 1600 break; 1601 } 1602 if (!channel) break; 1603 1604 // if received while waiting for le connection response, assume legacy device 1605 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 1606 channel->state = L2CAP_STATE_CLOSED; 1607 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 1608 l2cap_emit_channel_opened(channel, 0x0002); 1609 1610 // discard channel 1611 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1612 btstack_memory_l2cap_channel_free(channel); 1613 break; 1614 } 1615 break; 1616 1617 #ifdef ENABLE_LE_DATA_CHANNELS 1618 case LE_CREDIT_BASED_CONNECTION_REQUEST: 1619 1620 // get hci connection, bail if not found (must not happen) 1621 connection = hci_connection_for_handle(handle); 1622 if (!connection) return 0; 1623 1624 // check if service registered 1625 le_psm = little_endian_read_16(command, 4); 1626 service = l2cap_le_get_service(le_psm); 1627 1628 if (service){ 1629 1630 uint16_t source_cid = little_endian_read_16(command, 6); 1631 if (source_cid < 0x40){ 1632 // 0x0009 Connection refused - Invalid Source CID 1633 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0009); 1634 return 1; 1635 } 1636 1637 // go through list of channels for this ACL connection and check if we get a match 1638 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1639 while (btstack_linked_list_iterator_has_next(&it)){ 1640 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1641 if (a_channel->con_handle != handle) continue; 1642 if (a_channel->remote_cid != source_cid) continue; 1643 // 0x000a Connection refused - Source CID already allocated 1644 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x000a); 1645 return 1; 1646 } 1647 1648 // security: check encryption 1649 if (service->required_security_level >= LEVEL_2){ 1650 if (sm_encryption_key_size(handle) == 0){ 1651 // 0x0008 Connection refused - insufficient encryption 1652 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0008); 1653 return 1; 1654 } 1655 // anything less than 16 byte key size is insufficient 1656 if (sm_encryption_key_size(handle) < 16){ 1657 // 0x0007 Connection refused – insufficient encryption key size 1658 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0007); 1659 return 1; 1660 } 1661 } 1662 1663 // security: check authencation 1664 if (service->required_security_level >= LEVEL_3){ 1665 if (!sm_authenticated(handle)){ 1666 // 0x0005 Connection refused – insufficient authentication 1667 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0005); 1668 return 1; 1669 } 1670 } 1671 1672 // security: check authorization 1673 if (service->required_security_level >= LEVEL_4){ 1674 if (sm_authorization_state(handle) != AUTHORIZATION_GRANTED){ 1675 // 0x0006 Connection refused – insufficient authorization 1676 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0006); 1677 return 1; 1678 } 1679 } 1680 1681 // allocate channel 1682 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 1683 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 1684 if (!channel){ 1685 // 0x0004 Connection refused – no resources available 1686 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0004); 1687 return 1; 1688 } 1689 1690 channel->con_handle = handle; 1691 channel->remote_cid = source_cid; 1692 channel->remote_sig_id = sig_id; 1693 channel->remote_mtu = little_endian_read_16(command, 8); 1694 channel->remote_mps = little_endian_read_16(command, 10); 1695 channel->credits_outgoing = little_endian_read_16(command, 12); 1696 1697 // set initial state 1698 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1699 1700 // add to connections list 1701 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1702 1703 // post connection request event 1704 l2cap_emit_connection_request(channel); 1705 1706 } else { 1707 // Connection refused – LE_PSM not supported 1708 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0002); 1709 } 1710 break; 1711 1712 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 1713 // Find channel for this sig_id and connection handle 1714 channel = NULL; 1715 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1716 while (btstack_linked_list_iterator_has_next(&it)){ 1717 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1718 if (a_channel->con_handle != handle) continue; 1719 if (a_channel->local_sig_id != sig_id) continue; 1720 channel = a_channel; 1721 break; 1722 } 1723 if (!channel) break; 1724 1725 // cid + 0 1726 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 1727 if (result){ 1728 channel->state = L2CAP_STATE_CLOSED; 1729 // map l2cap connection response result to BTstack status enumeration 1730 l2cap_emit_channel_opened(channel, result); 1731 1732 // discard channel 1733 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1734 btstack_memory_l2cap_channel_free(channel); 1735 break; 1736 } 1737 1738 // success 1739 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1740 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1741 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 1742 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 1743 channel->state = L2CAP_STATE_OPEN; 1744 l2cap_emit_channel_opened(channel, result); 1745 break; 1746 1747 case LE_FLOW_CONTROL_CREDIT: 1748 // find channel 1749 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1750 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1751 if (!channel) { 1752 log_error("l2cap: no channel for cid 0x%02x", local_cid); 1753 break; 1754 } 1755 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1756 credits_before = channel->credits_outgoing; 1757 channel->credits_outgoing += new_credits; 1758 // check for credit overrun 1759 if (credits_before > channel->credits_outgoing){ 1760 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 1761 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1762 break; 1763 } 1764 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 1765 break; 1766 #endif 1767 1768 case DISCONNECTION_REQUEST: 1769 // find channel 1770 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1771 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1772 if (!channel) { 1773 log_error("l2cap: no channel for cid 0x%02x", local_cid); 1774 break; 1775 } 1776 channel->remote_sig_id = sig_id; 1777 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1778 break; 1779 1780 case DISCONNECTION_RESPONSE: 1781 break; 1782 1783 default: 1784 // command unknown -> reject command 1785 return 0; 1786 } 1787 return 1; 1788 } 1789 #endif 1790 1791 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 1792 1793 // Get Channel ID 1794 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1795 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1796 1797 switch (channel_id) { 1798 1799 case L2CAP_CID_SIGNALING: { 1800 uint16_t command_offset = 8; 1801 while (command_offset < size) { 1802 // handle signaling commands 1803 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1804 1805 // increment command_offset 1806 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1807 } 1808 break; 1809 } 1810 1811 #ifdef ENABLE_BLE 1812 case L2CAP_CID_SIGNALING_LE: { 1813 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1814 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 1815 if (!valid){ 1816 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1817 } 1818 break; 1819 } 1820 #endif 1821 1822 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1823 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 1824 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1825 } 1826 break; 1827 1828 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1829 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 1830 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1831 } 1832 break; 1833 1834 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 1835 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 1836 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1837 } 1838 break; 1839 1840 default: { 1841 // Find channel for this channel_id and connection handle 1842 l2cap_channel_t * l2cap_channel; 1843 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 1844 if (l2cap_channel) { 1845 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1846 } 1847 #ifdef ENABLE_BLE 1848 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 1849 if (l2cap_channel) { 1850 // credit counting 1851 if (l2cap_channel->credits_incoming == 0){ 1852 log_error("LE Data Channel packet received but no incoming credits"); 1853 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1854 break; 1855 } 1856 l2cap_channel->credits_incoming--; 1857 1858 // automatic credits 1859 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 1860 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 1861 } 1862 1863 // first fragment 1864 uint16_t pos = 0; 1865 if (!l2cap_channel->receive_sdu_len){ 1866 l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 1867 l2cap_channel->receive_sdu_pos = 0; 1868 pos += 2; 1869 size -= 2; 1870 } 1871 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); 1872 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 1873 // done? 1874 log_info("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 1875 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 1876 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 1877 l2cap_channel->receive_sdu_len = 0; 1878 } 1879 } else { 1880 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 1881 } 1882 #endif 1883 break; 1884 } 1885 } 1886 1887 l2cap_run(); 1888 } 1889 1890 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1891 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 1892 channel->state = L2CAP_STATE_CLOSED; 1893 l2cap_emit_channel_closed(channel); 1894 // discard channel 1895 l2cap_stop_rtx(channel); 1896 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1897 btstack_memory_l2cap_channel_free(channel); 1898 } 1899 1900 #ifdef ENABLE_LE_DATA_CHANNELS 1901 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1902 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 1903 channel->state = L2CAP_STATE_CLOSED; 1904 l2cap_emit_channel_closed(channel); 1905 // discard channel 1906 l2cap_stop_rtx(channel); 1907 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1908 btstack_memory_l2cap_channel_free(channel); 1909 } 1910 #endif 1911 1912 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 1913 btstack_linked_list_iterator_t it; 1914 btstack_linked_list_iterator_init(&it, services); 1915 while (btstack_linked_list_iterator_has_next(&it)){ 1916 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 1917 if ( service->psm == psm){ 1918 return service; 1919 }; 1920 } 1921 return NULL; 1922 } 1923 1924 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 1925 return l2cap_get_service_internal(&l2cap_services, psm); 1926 } 1927 1928 1929 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 1930 1931 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1932 1933 // check for alread registered psm 1934 l2cap_service_t *service = l2cap_get_service(psm); 1935 if (service) { 1936 log_error("l2cap_register_service: PSM %u already registered", psm); 1937 return L2CAP_SERVICE_ALREADY_REGISTERED; 1938 } 1939 1940 // alloc structure 1941 service = btstack_memory_l2cap_service_get(); 1942 if (!service) { 1943 log_error("l2cap_register_service: no memory for l2cap_service_t"); 1944 return BTSTACK_MEMORY_ALLOC_FAILED; 1945 } 1946 1947 // fill in 1948 service->psm = psm; 1949 service->mtu = mtu; 1950 service->packet_handler = service_packet_handler; 1951 service->required_security_level = security_level; 1952 1953 // add to services list 1954 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 1955 1956 // enable page scan 1957 gap_connectable_control(1); 1958 1959 return 0; 1960 } 1961 1962 uint8_t l2cap_unregister_service(uint16_t psm){ 1963 1964 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1965 1966 l2cap_service_t *service = l2cap_get_service(psm); 1967 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 1968 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 1969 btstack_memory_l2cap_service_free(service); 1970 1971 // disable page scan when no services registered 1972 if (btstack_linked_list_empty(&l2cap_services)) { 1973 gap_connectable_control(0); 1974 } 1975 return 0; 1976 } 1977 1978 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1979 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 1980 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 1981 if (index < 0) return; 1982 fixed_channels[index].callback = the_packet_handler; 1983 } 1984 1985 #ifdef ENABLE_BLE 1986 1987 #ifdef ENABLE_LE_DATA_CHANNELS 1988 1989 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 1990 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 1991 } 1992 1993 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 1994 1995 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 1996 1997 // check for alread registered psm 1998 l2cap_service_t *service = l2cap_le_get_service(psm); 1999 if (service) { 2000 return L2CAP_SERVICE_ALREADY_REGISTERED; 2001 } 2002 2003 // alloc structure 2004 service = btstack_memory_l2cap_service_get(); 2005 if (!service) { 2006 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 2007 return BTSTACK_MEMORY_ALLOC_FAILED; 2008 } 2009 2010 // fill in 2011 service->psm = psm; 2012 service->mtu = 0; 2013 service->packet_handler = packet_handler; 2014 service->required_security_level = security_level; 2015 2016 // add to services list 2017 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 2018 2019 // done 2020 return 0; 2021 } 2022 2023 uint8_t l2cap_le_unregister_service(uint16_t psm) { 2024 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 2025 l2cap_service_t *service = l2cap_le_get_service(psm); 2026 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2027 2028 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 2029 btstack_memory_l2cap_service_free(service); 2030 return 0; 2031 } 2032 2033 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 2034 // get channel 2035 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2036 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2037 2038 // validate state 2039 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2040 return ERROR_CODE_COMMAND_DISALLOWED; 2041 } 2042 2043 // set state accept connection 2044 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 2045 channel->receive_sdu_buffer = receive_sdu_buffer; 2046 channel->local_mtu = mtu; 2047 channel->new_credits_incoming = initial_credits; 2048 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2049 2050 // test 2051 // channel->new_credits_incoming = 1; 2052 2053 // go 2054 l2cap_run(); 2055 return 0; 2056 } 2057 2058 /** 2059 * @brief Deny incoming LE Data Channel connection due to resource constraints 2060 * @param local_cid L2CAP LE Data Channel Identifier 2061 */ 2062 2063 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 2064 // get channel 2065 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2066 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2067 2068 // validate state 2069 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2070 return ERROR_CODE_COMMAND_DISALLOWED; 2071 } 2072 2073 // set state decline connection 2074 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 2075 channel->reason = 0x04; // no resources available 2076 l2cap_run(); 2077 return 0; 2078 } 2079 2080 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 2081 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 2082 uint16_t * out_local_cid) { 2083 2084 log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 2085 2086 2087 hci_connection_t * connection = hci_connection_for_handle(con_handle); 2088 if (!connection) { 2089 log_error("no hci_connection for handle 0x%04x", con_handle); 2090 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 2091 } 2092 2093 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, connection->address, connection->address_type, psm, mtu, security_level); 2094 if (!channel) { 2095 return BTSTACK_MEMORY_ALLOC_FAILED; 2096 } 2097 log_info("l2cap_le_create_channel %p", channel); 2098 2099 // store local_cid 2100 if (out_local_cid){ 2101 *out_local_cid = channel->local_cid; 2102 } 2103 2104 // provide buffer 2105 channel->con_handle = con_handle; 2106 channel->receive_sdu_buffer = receive_sdu_buffer; 2107 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 2108 channel->new_credits_incoming = initial_credits; 2109 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2110 2111 // add to connections list 2112 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2113 2114 // go 2115 l2cap_run(); 2116 return 0; 2117 } 2118 2119 /** 2120 * @brief Provide credtis for LE Data Channel 2121 * @param local_cid L2CAP LE Data Channel Identifier 2122 * @param credits Number additional credits for peer 2123 */ 2124 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 2125 2126 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2127 if (!channel) { 2128 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2129 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2130 } 2131 2132 // check state 2133 if (channel->state != L2CAP_STATE_OPEN){ 2134 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 2135 } 2136 2137 // assert incoming credits + credits <= 0xffff 2138 uint32_t total_credits = channel->credits_incoming; 2139 total_credits += channel->new_credits_incoming; 2140 total_credits += credits; 2141 if (total_credits > 0xffff){ 2142 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 2143 channel->new_credits_incoming, credits); 2144 } 2145 2146 // set credits_granted 2147 channel->new_credits_incoming += credits; 2148 2149 // go 2150 l2cap_run(); 2151 return 0; 2152 } 2153 2154 /** 2155 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 2156 * @param local_cid L2CAP LE Data Channel Identifier 2157 */ 2158 int l2cap_le_can_send_now(uint16_t local_cid){ 2159 // check if data can be sent via le at all 2160 return 0; 2161 } 2162 2163 /** 2164 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 2165 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 2166 * so packet handler should be ready to handle it 2167 * @param local_cid L2CAP LE Data Channel Identifier 2168 */ 2169 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 2170 // same as for non-le 2171 return 0; 2172 } 2173 2174 /** 2175 * @brief Send data via LE Data Channel 2176 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 2177 * @param local_cid L2CAP LE Data Channel Identifier 2178 * @param data data to send 2179 * @param size data size 2180 */ 2181 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 2182 2183 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2184 if (!channel) { 2185 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2186 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2187 } 2188 2189 if (len > channel->remote_mtu){ 2190 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 2191 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 2192 } 2193 2194 if (channel->send_sdu_buffer){ 2195 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 2196 return BTSTACK_ACL_BUFFERS_FULL; 2197 } 2198 2199 channel->send_sdu_buffer = data; 2200 channel->send_sdu_len = len; 2201 channel->send_sdu_pos = 0; 2202 2203 l2cap_run(); 2204 return 0; 2205 } 2206 2207 /** 2208 * @brief Disconnect from LE Data Channel 2209 * @param local_cid L2CAP LE Data Channel Identifier 2210 */ 2211 uint8_t l2cap_le_disconnect(uint16_t local_cid) 2212 { 2213 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2214 if (!channel) { 2215 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2216 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2217 } 2218 2219 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2220 l2cap_run(); 2221 return 0; 2222 } 2223 2224 #endif 2225 2226 #endif 2227