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_incoming_connection(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 96 #ifdef ENABLE_LE_DATA_CHANNELS 97 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status); 98 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel); 99 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid); 100 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel); 101 static void l2cap_le_finialize_channel_close(l2cap_channel_t *channel); 102 static inline l2cap_service_t * l2cap_le_get_service(uint16_t psm); 103 #endif 104 105 typedef struct l2cap_fixed_channel { 106 btstack_packet_handler_t callback; 107 uint8_t waiting_for_can_send_now; 108 } l2cap_fixed_channel_t; 109 110 static btstack_linked_list_t l2cap_channels; 111 static btstack_linked_list_t l2cap_services; 112 113 #ifdef ENABLE_LE_DATA_CHANNELS 114 static btstack_linked_list_t l2cap_le_channels; 115 static btstack_linked_list_t l2cap_le_services; 116 #endif 117 118 // used to cache l2cap rejects, echo, and informational requests 119 static l2cap_signaling_response_t signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; 120 static int signaling_responses_pending; 121 122 static uint8_t require_security_level2_for_outgoing_sdp; 123 124 static btstack_packet_callback_registration_t hci_event_callback_registration; 125 126 static btstack_packet_handler_t l2cap_event_packet_handler; 127 static l2cap_fixed_channel_t fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_SIZE]; 128 129 static uint16_t l2cap_fixed_channel_table_channel_id_for_index(int index){ 130 switch (index){ 131 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL: 132 return L2CAP_CID_ATTRIBUTE_PROTOCOL; 133 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL: 134 return L2CAP_CID_SECURITY_MANAGER_PROTOCOL; 135 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL: 136 return L2CAP_CID_CONNECTIONLESS_CHANNEL; 137 default: 138 return 0; 139 } 140 } 141 static int l2cap_fixed_channel_table_index_for_channel_id(uint16_t channel_id){ 142 switch (channel_id){ 143 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 144 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL; 145 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 146 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL; 147 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 148 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL; 149 default: 150 return -1; 151 } 152 } 153 154 static int l2cap_fixed_channel_table_index_is_le(int index){ 155 if (index == L2CAP_CID_CONNECTIONLESS_CHANNEL) return 0; 156 return 1; 157 } 158 159 void l2cap_init(void){ 160 signaling_responses_pending = 0; 161 162 l2cap_channels = NULL; 163 l2cap_services = NULL; 164 l2cap_le_services = NULL; 165 l2cap_le_channels = NULL; 166 167 l2cap_event_packet_handler = NULL; 168 memset(fixed_channels, 0, sizeof(fixed_channels)); 169 170 require_security_level2_for_outgoing_sdp = 0; 171 172 // 173 // register callback with HCI 174 // 175 hci_event_callback_registration.callback = &l2cap_hci_event_handler; 176 hci_add_event_handler(&hci_event_callback_registration); 177 178 hci_register_acl_packet_handler(&l2cap_acl_handler); 179 180 gap_connectable_control(0); // no services yet 181 } 182 183 void l2cap_register_packet_handler(void (*handler)(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 184 l2cap_event_packet_handler = handler; 185 } 186 187 static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 188 (* (channel->packet_handler))(type, channel->local_cid, data, size); 189 } 190 191 static void l2cap_emit_simple_event_with_cid(l2cap_channel_t * channel, uint8_t event_code){ 192 uint8_t event[4]; 193 event[0] = event_code; 194 event[1] = sizeof(event) - 2; 195 little_endian_store_16(event, 2, channel->local_cid); 196 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 197 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 198 } 199 200 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 201 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", 202 status, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 203 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 204 uint8_t event[23]; 205 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 206 event[1] = sizeof(event) - 2; 207 event[2] = status; 208 reverse_bd_addr(channel->address, &event[3]); 209 little_endian_store_16(event, 9, channel->con_handle); 210 little_endian_store_16(event, 11, channel->psm); 211 little_endian_store_16(event, 13, channel->local_cid); 212 little_endian_store_16(event, 15, channel->remote_cid); 213 little_endian_store_16(event, 17, channel->local_mtu); 214 little_endian_store_16(event, 19, channel->remote_mtu); 215 little_endian_store_16(event, 21, channel->flush_timeout); 216 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 217 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 218 } 219 220 static void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 221 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 222 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 223 } 224 225 226 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel) { 227 log_info("L2CAP_EVENT_CHANNEL_CAN_SEND_NOW local_cid 0x%x", channel); 228 uint8_t event[4]; 229 event[0] = L2CAP_EVENT_CAN_SEND_NOW; 230 event[1] = sizeof(event) - 2; 231 little_endian_store_16(event, 2, channel); 232 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 233 packet_handler(HCI_EVENT_PACKET, channel, event, sizeof(event)); 234 } 235 236 static void l2cap_emit_incoming_connection(l2cap_channel_t *channel) { 237 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 238 bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid); 239 uint8_t event[16]; 240 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 241 event[1] = sizeof(event) - 2; 242 reverse_bd_addr(channel->address, &event[2]); 243 little_endian_store_16(event, 8, channel->con_handle); 244 little_endian_store_16(event, 10, channel->psm); 245 little_endian_store_16(event, 12, channel->local_cid); 246 little_endian_store_16(event, 14, channel->remote_cid); 247 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 248 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 249 } 250 251 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 252 uint8_t event[6]; 253 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 254 event[1] = 4; 255 little_endian_store_16(event, 2, con_handle); 256 little_endian_store_16(event, 4, result); 257 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 258 if (!l2cap_event_packet_handler) return; 259 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 260 } 261 262 static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 263 btstack_linked_list_iterator_t it; 264 btstack_linked_list_iterator_init(&it, &l2cap_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 } 273 274 /// 275 276 void l2cap_request_can_send_now_event(uint16_t local_cid){ 277 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 278 if (!channel) return; 279 channel->waiting_for_can_send_now = 1; 280 l2cap_notify_channel_can_send(); 281 } 282 283 void l2cap_request_can_send_fix_channel_now_event(hci_con_handle_t con_handle, uint16_t channel_id){ 284 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 285 if (index < 0) return; 286 fixed_channels[index].waiting_for_can_send_now = 1; 287 l2cap_notify_channel_can_send(); 288 } 289 290 /// 291 292 int l2cap_can_send_packet_now(uint16_t local_cid){ 293 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 294 if (!channel) return 0; 295 return hci_can_send_acl_packet_now(channel->con_handle); 296 } 297 298 int l2cap_can_send_prepared_packet_now(uint16_t local_cid){ 299 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 300 if (!channel) return 0; 301 return hci_can_send_prepared_acl_packet_now(channel->con_handle); 302 } 303 304 int l2cap_can_send_fixed_channel_packet_now(hci_con_handle_t con_handle, uint16_t channel_id){ 305 return hci_can_send_acl_packet_now(con_handle); 306 } 307 308 /// 309 310 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 311 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 312 if (channel) { 313 return channel->remote_mtu; 314 } 315 return 0; 316 } 317 318 static l2cap_channel_t * l2cap_channel_for_rtx_timer(btstack_timer_source_t * ts){ 319 btstack_linked_list_iterator_t it; 320 btstack_linked_list_iterator_init(&it, &l2cap_channels); 321 while (btstack_linked_list_iterator_has_next(&it)){ 322 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 323 if ( &channel->rtx == ts) { 324 return channel; 325 } 326 } 327 return NULL; 328 } 329 330 static void l2cap_rtx_timeout(btstack_timer_source_t * ts){ 331 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 332 if (!channel) return; 333 334 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 335 336 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 337 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 338 // notify client 339 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 340 341 // discard channel 342 // no need to stop timer here, it is removed from list during timer callback 343 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 344 btstack_memory_l2cap_channel_free(channel); 345 } 346 347 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 348 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 349 btstack_run_loop_remove_timer(&channel->rtx); 350 } 351 352 static void l2cap_start_rtx(l2cap_channel_t * channel){ 353 l2cap_stop_rtx(channel); 354 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 355 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 356 btstack_run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 357 btstack_run_loop_add_timer(&channel->rtx); 358 } 359 360 static void l2cap_start_ertx(l2cap_channel_t * channel){ 361 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 362 l2cap_stop_rtx(channel); 363 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 364 btstack_run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 365 btstack_run_loop_add_timer(&channel->rtx); 366 } 367 368 void l2cap_require_security_level_2_for_outgoing_sdp(void){ 369 require_security_level2_for_outgoing_sdp = 1; 370 } 371 372 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 373 return (psm == PSM_SDP) && (!require_security_level2_for_outgoing_sdp); 374 } 375 376 static int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 377 378 if (!hci_can_send_acl_packet_now(handle)){ 379 log_info("l2cap_send_signaling_packet, cannot send"); 380 return BTSTACK_ACL_BUFFERS_FULL; 381 } 382 383 // log_info("l2cap_send_signaling_packet type %u", cmd); 384 hci_reserve_packet_buffer(); 385 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 386 va_list argptr; 387 va_start(argptr, identifier); 388 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 389 va_end(argptr); 390 // log_info("l2cap_send_signaling_packet con %u!", handle); 391 return hci_send_acl_packet_buffer(len); 392 } 393 394 #ifdef ENABLE_BLE 395 static int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 396 397 if (!hci_can_send_acl_packet_now(handle)){ 398 log_info("l2cap_send_signaling_packet, cannot send"); 399 return BTSTACK_ACL_BUFFERS_FULL; 400 } 401 402 // log_info("l2cap_send_signaling_packet type %u", cmd); 403 hci_reserve_packet_buffer(); 404 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 405 va_list argptr; 406 va_start(argptr, identifier); 407 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 408 va_end(argptr); 409 // log_info("l2cap_send_signaling_packet con %u!", handle); 410 return hci_send_acl_packet_buffer(len); 411 } 412 #endif 413 414 uint8_t *l2cap_get_outgoing_buffer(void){ 415 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 416 } 417 418 int l2cap_reserve_packet_buffer(void){ 419 return hci_reserve_packet_buffer(); 420 } 421 422 void l2cap_release_packet_buffer(void){ 423 hci_release_packet_buffer(); 424 } 425 426 static void l2cap_setup_header(uint8_t * acl_buffer, hci_con_handle_t con_handle, uint16_t remote_cid, uint16_t len){ 427 428 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 429 430 // 0 - Connection handle : PB=pb : BC=00 431 little_endian_store_16(acl_buffer, 0, con_handle | (pb << 12) | (0 << 14)); 432 // 2 - ACL length 433 little_endian_store_16(acl_buffer, 2, len + 4); 434 // 4 - L2CAP packet length 435 little_endian_store_16(acl_buffer, 4, len + 0); 436 // 6 - L2CAP channel DEST 437 little_endian_store_16(acl_buffer, 6, remote_cid); 438 } 439 440 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 441 442 if (!hci_is_packet_buffer_reserved()){ 443 log_error("l2cap_send_prepared called without reserving packet first"); 444 return BTSTACK_ACL_BUFFERS_FULL; 445 } 446 447 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 448 if (!channel) { 449 log_error("l2cap_send_prepared no channel for cid 0x%02x", local_cid); 450 return -1; // TODO: define error 451 } 452 453 if (!hci_can_send_prepared_acl_packet_now(channel->con_handle)){ 454 log_info("l2cap_send_prepared cid 0x%02x, cannot send", local_cid); 455 return BTSTACK_ACL_BUFFERS_FULL; 456 } 457 458 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used", local_cid, channel->con_handle); 459 460 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 461 l2cap_setup_header(acl_buffer, channel->con_handle, channel->remote_cid, len); 462 // send 463 return hci_send_acl_packet_buffer(len+8); 464 } 465 466 int l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len){ 467 468 if (!hci_is_packet_buffer_reserved()){ 469 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 470 return BTSTACK_ACL_BUFFERS_FULL; 471 } 472 473 if (!hci_can_send_prepared_acl_packet_now(con_handle)){ 474 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send", con_handle, cid); 475 return BTSTACK_ACL_BUFFERS_FULL; 476 } 477 478 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x", con_handle, cid); 479 480 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 481 l2cap_setup_header(acl_buffer, con_handle, cid, len); 482 // send 483 return hci_send_acl_packet_buffer(len+8); 484 } 485 486 int l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len){ 487 488 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 489 if (!channel) { 490 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 491 return -1; // TODO: define error 492 } 493 494 if (len > channel->remote_mtu){ 495 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 496 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 497 } 498 499 if (!hci_can_send_acl_packet_now(channel->con_handle)){ 500 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 501 return BTSTACK_ACL_BUFFERS_FULL; 502 } 503 504 hci_reserve_packet_buffer(); 505 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 506 507 memcpy(&acl_buffer[8], data, len); 508 509 return l2cap_send_prepared(local_cid, len); 510 } 511 512 int l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len){ 513 514 if (!hci_can_send_acl_packet_now(con_handle)){ 515 log_info("l2cap_send cid 0x%02x, cannot send", cid); 516 return BTSTACK_ACL_BUFFERS_FULL; 517 } 518 519 hci_reserve_packet_buffer(); 520 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 521 522 memcpy(&acl_buffer[8], data, len); 523 524 return l2cap_send_prepared_connectionless(con_handle, cid, len); 525 } 526 527 int l2cap_send_echo_request(hci_con_handle_t con_handle, uint8_t *data, uint16_t len){ 528 return l2cap_send_signaling_packet(con_handle, ECHO_REQUEST, 0x77, len, data); 529 } 530 531 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 532 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 533 } 534 535 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 536 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 537 } 538 539 540 541 // MARK: L2CAP_RUN 542 // process outstanding signaling tasks 543 static void l2cap_run(void){ 544 545 // log_info("l2cap_run: entered"); 546 547 // check pending signaling responses 548 while (signaling_responses_pending){ 549 550 hci_con_handle_t handle = signaling_responses[0].handle; 551 552 if (!hci_can_send_acl_packet_now(handle)) break; 553 554 uint8_t sig_id = signaling_responses[0].sig_id; 555 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 556 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 557 uint8_t response_code = signaling_responses[0].code; 558 559 // remove first item before sending (to avoid sending response mutliple times) 560 signaling_responses_pending--; 561 int i; 562 for (i=0; i < signaling_responses_pending; i++){ 563 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 564 } 565 566 switch (response_code){ 567 case CONNECTION_REQUEST: 568 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 569 // also disconnect if result is 0x0003 - security blocked 570 if (result == 0x0003){ 571 hci_disconnect_security_block(handle); 572 } 573 break; 574 case ECHO_REQUEST: 575 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 576 break; 577 case INFORMATION_REQUEST: 578 switch (infoType){ 579 case 1: { // Connectionless MTU 580 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 581 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 582 break; 583 } 584 case 2: { // Extended Features Supported 585 // extended features request supported, features: fixed channels, unicast connectionless data reception 586 uint32_t features = 0x280; 587 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 588 break; 589 } 590 case 3: { // Fixed Channels Supported 591 uint8_t map[8]; 592 memset(map, 0, 8); 593 map[0] = 0x06; // L2CAP Signaling Channel (0x02) + Connectionless reception (0x04) 594 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 595 break; 596 } 597 default: 598 // all other types are not supported 599 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 600 break; 601 } 602 break; 603 case COMMAND_REJECT: 604 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 605 break; 606 #ifdef ENABLE_BLE 607 case LE_CREDIT_BASED_CONNECTION_REQUEST: 608 l2cap_send_le_signaling_packet(handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, sig_id, 0, 0, 0, 0, result); 609 break; 610 case COMMAND_REJECT_LE: 611 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 612 break; 613 #endif 614 default: 615 // should not happen 616 break; 617 } 618 } 619 620 uint8_t config_options[4]; 621 btstack_linked_list_iterator_t it; 622 btstack_linked_list_iterator_init(&it, &l2cap_channels); 623 while (btstack_linked_list_iterator_has_next(&it)){ 624 625 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 626 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 627 switch (channel->state){ 628 629 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 630 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 631 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 632 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 633 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 634 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 635 } 636 break; 637 638 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 639 if (!hci_can_send_command_packet_now()) break; 640 // send connection request - set state first 641 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 642 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 643 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 644 break; 645 646 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 647 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 648 channel->state = L2CAP_STATE_INVALID; 649 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 650 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 651 l2cap_stop_rtx(channel); 652 btstack_linked_list_iterator_remove(&it); 653 btstack_memory_l2cap_channel_free(channel); 654 break; 655 656 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 657 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 658 channel->state = L2CAP_STATE_CONFIG; 659 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 660 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 661 break; 662 663 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 664 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 665 // success, start l2cap handshake 666 channel->local_sig_id = l2cap_next_sig_id(); 667 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 668 l2cap_send_signaling_packet( channel->con_handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 669 l2cap_start_rtx(channel); 670 break; 671 672 case L2CAP_STATE_CONFIG: 673 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 674 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 675 uint16_t flags = 0; 676 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 677 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 678 flags = 1; 679 } else { 680 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 681 } 682 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 683 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 684 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 685 config_options[0] = 1; // MTU 686 config_options[1] = 2; // len param 687 little_endian_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 688 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 689 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 690 } else { 691 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 692 } 693 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 694 } 695 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 696 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 697 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 698 channel->local_sig_id = l2cap_next_sig_id(); 699 config_options[0] = 1; // MTU 700 config_options[1] = 2; // len param 701 little_endian_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 702 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 703 l2cap_start_rtx(channel); 704 } 705 if (l2cap_channel_ready_for_open(channel)){ 706 channel->state = L2CAP_STATE_OPEN; 707 l2cap_emit_channel_opened(channel, 0); // success 708 } 709 break; 710 711 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 712 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 713 channel->state = L2CAP_STATE_INVALID; 714 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 715 // 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 :) 716 l2cap_finialize_channel_close(channel); // -- remove from list 717 break; 718 719 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 720 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 721 channel->local_sig_id = l2cap_next_sig_id(); 722 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 723 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 724 break; 725 default: 726 break; 727 } 728 } 729 730 #ifdef ENABLE_BLE 731 #ifdef ENABLE_LE_DATA_CHANNELS 732 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 733 while (btstack_linked_list_iterator_has_next(&it)){ 734 uint8_t * acl_buffer; 735 uint8_t * l2cap_payload; 736 uint16_t pos; 737 uint16_t payload_size; 738 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 739 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 740 switch (channel->state){ 741 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 742 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 743 channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; 744 // le psm, source cid, mtu, mps, initial credits 745 channel->local_sig_id = l2cap_next_sig_id(); 746 channel->credits_incoming = channel->new_credits_incoming; 747 channel->new_credits_incoming = 0; 748 l2cap_send_le_signaling_packet( channel->con_handle, LE_CREDIT_BASED_CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid, channel->local_mtu, 23, channel->credits_incoming); 749 break; 750 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 751 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 752 // TODO: support larger MPS 753 channel->state = L2CAP_STATE_OPEN; 754 channel->credits_incoming = channel->new_credits_incoming; 755 channel->new_credits_incoming = 0; 756 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->local_mtu, 23, channel->credits_incoming, 0); 757 // notify client 758 l2cap_emit_le_channel_opened(channel, 0); 759 break; 760 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 761 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 762 channel->state = L2CAP_STATE_INVALID; 763 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, 0, 0, channel->reason); 764 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 765 l2cap_stop_rtx(channel); 766 btstack_linked_list_iterator_remove(&it); 767 btstack_memory_l2cap_channel_free(channel); 768 break; 769 case L2CAP_STATE_OPEN: 770 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 771 772 // send credits 773 if (channel->new_credits_incoming){ 774 log_info("l2cap: sending %u credits", channel->new_credits_incoming); 775 channel->local_sig_id = l2cap_next_sig_id(); 776 uint16_t new_credits = channel->new_credits_incoming; 777 channel->new_credits_incoming = 0; 778 channel->credits_incoming += new_credits; 779 l2cap_send_le_signaling_packet(channel->con_handle, LE_FLOW_CONTROL_CREDIT, channel->local_sig_id, channel->remote_cid, new_credits); 780 break; 781 } 782 783 // send data 784 if (!channel->send_sdu_buffer) break; 785 if (!channel->credits_outgoing) break; 786 787 // send part of SDU 788 hci_reserve_packet_buffer(); 789 acl_buffer = hci_get_outgoing_packet_buffer(); 790 l2cap_payload = acl_buffer + 8; 791 pos = 0; 792 if (!channel->send_sdu_pos){ 793 // store SDU len 794 channel->send_sdu_pos += 2; 795 little_endian_store_16(l2cap_payload, pos, channel->send_sdu_len); 796 pos += 2; 797 } 798 payload_size = btstack_min(channel->send_sdu_len + 2 - channel->send_sdu_pos, channel->remote_mps - pos); 799 log_info("len %u, pos %u => payload %u, credits %u", channel->send_sdu_len, channel->send_sdu_pos, payload_size, channel->credits_outgoing); 800 memcpy(&l2cap_payload[pos], &channel->send_sdu_buffer[channel->send_sdu_pos-2], payload_size); // -2 for virtual SDU len 801 pos += payload_size; 802 channel->send_sdu_pos += payload_size; 803 l2cap_setup_header(acl_buffer, channel->con_handle, channel->remote_cid, pos); 804 // done 805 806 channel->credits_outgoing--; 807 808 if (channel->send_sdu_pos >= channel->send_sdu_len + 2){ 809 channel->send_sdu_buffer = NULL; 810 // send done event 811 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_PACKET_SENT); 812 // inform about can send now 813 l2cap_le_notify_channel_can_send(channel); 814 } 815 hci_send_acl_packet_buffer(8 + pos); 816 break; 817 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 818 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 819 channel->local_sig_id = l2cap_next_sig_id(); 820 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 821 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 822 break; 823 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 824 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 825 channel->state = L2CAP_STATE_INVALID; 826 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 827 l2cap_le_finialize_channel_close(channel); // -- remove from list 828 break; 829 default: 830 break; 831 } 832 } 833 834 // send l2cap con paramter update if necessary 835 hci_connections_get_iterator(&it); 836 while(btstack_linked_list_iterator_has_next(&it)){ 837 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 838 if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; 839 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 840 switch (connection->le_con_parameter_update_state){ 841 case CON_PARAMETER_UPDATE_SEND_REQUEST: 842 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 843 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, connection->le_con_param_update_identifier, 844 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 845 break; 846 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 847 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 848 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 849 break; 850 case CON_PARAMETER_UPDATE_DENY: 851 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 852 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 853 break; 854 default: 855 break; 856 } 857 } 858 #endif 859 #endif 860 861 // log_info("l2cap_run: exit"); 862 } 863 864 uint16_t l2cap_max_mtu(void){ 865 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 866 } 867 868 uint16_t l2cap_max_le_mtu(void){ 869 return l2cap_max_mtu(); 870 } 871 872 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 873 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 874 log_info("l2cap_handle_connection_complete expected state"); 875 // success, start l2cap handshake 876 channel->con_handle = con_handle; 877 // check remote SSP feature first 878 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 879 } 880 } 881 882 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 883 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 884 885 // we have been waiting for remote supported features, if both support SSP, 886 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)); 887 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 888 // request security level 2 889 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 890 gap_request_security_level(channel->con_handle, LEVEL_2); 891 return; 892 } 893 // fine, go ahead 894 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 895 } 896 897 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 898 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 899 900 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 901 if (!channel) { 902 return NULL; 903 } 904 905 // Init memory (make valgrind happy) 906 memset(channel, 0, sizeof(l2cap_channel_t)); 907 908 // fill in 909 channel->packet_handler = packet_handler; 910 bd_addr_copy(channel->address, address); 911 channel->address_type = address_type; 912 channel->psm = psm; 913 channel->local_mtu = local_mtu; 914 channel->remote_mtu = L2CAP_MINIMAL_MTU; 915 channel->required_security_level = security_level; 916 917 // 918 channel->local_cid = l2cap_next_local_cid(); 919 channel->con_handle = 0; 920 921 // set initial state 922 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 923 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 924 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 925 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 926 return channel; 927 } 928 929 /** 930 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 931 * @param packet_handler 932 * @param address 933 * @param psm 934 * @param mtu 935 * @param local_cid 936 */ 937 938 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){ 939 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, local_mtu); 940 941 if (local_mtu > l2cap_max_mtu()) { 942 local_mtu = l2cap_max_mtu(); 943 } 944 945 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 946 if (!channel) { 947 return BTSTACK_MEMORY_ALLOC_FAILED; 948 } 949 950 // add to connections list 951 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 952 953 // store local_cid 954 if (out_local_cid){ 955 *out_local_cid = channel->local_cid; 956 } 957 958 // check if hci connection is already usable 959 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 960 if (conn){ 961 log_info("l2cap_create_channel, hci connection already exists"); 962 l2cap_handle_connection_complete(conn->con_handle, channel); 963 // check if remote supported fearures are already received 964 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 965 l2cap_handle_remote_supported_features_received(channel); 966 } 967 } 968 969 l2cap_run(); 970 971 return 0; 972 } 973 974 void 975 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 976 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 977 // find channel for local_cid 978 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 979 if (channel) { 980 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 981 } 982 // process 983 l2cap_run(); 984 } 985 986 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 987 btstack_linked_list_iterator_t it; 988 btstack_linked_list_iterator_init(&it, &l2cap_channels); 989 while (btstack_linked_list_iterator_has_next(&it)){ 990 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 991 if ( bd_addr_cmp( channel->address, address) != 0) continue; 992 // channel for this address found 993 switch (channel->state){ 994 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 995 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 996 // failure, forward error code 997 l2cap_emit_channel_opened(channel, status); 998 // discard channel 999 l2cap_stop_rtx(channel); 1000 btstack_linked_list_iterator_remove(&it); 1001 btstack_memory_l2cap_channel_free(channel); 1002 break; 1003 default: 1004 break; 1005 } 1006 } 1007 } 1008 1009 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1010 btstack_linked_list_iterator_t it; 1011 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1012 while (btstack_linked_list_iterator_has_next(&it)){ 1013 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1014 if ( ! bd_addr_cmp( channel->address, address) ){ 1015 l2cap_handle_connection_complete(handle, channel); 1016 } 1017 } 1018 // process 1019 l2cap_run(); 1020 } 1021 1022 static void l2cap_notify_channel_can_send(void){ 1023 btstack_linked_list_iterator_t it; 1024 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1025 while (btstack_linked_list_iterator_has_next(&it)){ 1026 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1027 if (!channel->waiting_for_can_send_now) continue; 1028 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1029 channel->waiting_for_can_send_now = 0; 1030 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1031 } 1032 1033 1034 int i; 1035 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1036 if (!fixed_channels[i].callback) continue; 1037 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1038 int can_send; 1039 if (l2cap_fixed_channel_table_index_is_le(i)){ 1040 can_send = hci_can_send_acl_le_packet_now(); 1041 } else { 1042 can_send = hci_can_send_acl_classic_packet_now(); 1043 } 1044 if (!can_send) continue; 1045 fixed_channels[i].waiting_for_can_send_now = 0; 1046 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1047 } 1048 } 1049 1050 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1051 1052 bd_addr_t address; 1053 hci_con_handle_t handle; 1054 btstack_linked_list_iterator_t it; 1055 int hci_con_used; 1056 1057 switch(hci_event_packet_get_type(packet)){ 1058 1059 // handle connection complete events 1060 case HCI_EVENT_CONNECTION_COMPLETE: 1061 reverse_bd_addr(&packet[5], address); 1062 if (packet[2] == 0){ 1063 handle = little_endian_read_16(packet, 3); 1064 l2cap_handle_connection_success_for_addr(address, handle); 1065 } else { 1066 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1067 } 1068 break; 1069 1070 // handle successful create connection cancel command 1071 case HCI_EVENT_COMMAND_COMPLETE: 1072 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1073 if (packet[5] == 0){ 1074 reverse_bd_addr(&packet[6], address); 1075 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1076 l2cap_handle_connection_failed_for_addr(address, 0x16); 1077 } 1078 } 1079 l2cap_run(); // try sending signaling packets first 1080 break; 1081 1082 case HCI_EVENT_COMMAND_STATUS: 1083 l2cap_run(); // try sending signaling packets first 1084 break; 1085 1086 // handle disconnection complete events 1087 case HCI_EVENT_DISCONNECTION_COMPLETE: 1088 // send l2cap disconnect events for all channels on this handle and free them 1089 handle = little_endian_read_16(packet, 3); 1090 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1091 while (btstack_linked_list_iterator_has_next(&it)){ 1092 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1093 if (channel->con_handle != handle) continue; 1094 l2cap_emit_channel_closed(channel); 1095 l2cap_stop_rtx(channel); 1096 btstack_linked_list_iterator_remove(&it); 1097 btstack_memory_l2cap_channel_free(channel); 1098 } 1099 #ifdef ENABLE_BLE 1100 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1101 while (btstack_linked_list_iterator_has_next(&it)){ 1102 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1103 if (channel->con_handle != handle) continue; 1104 l2cap_emit_channel_closed(channel); 1105 btstack_linked_list_iterator_remove(&it); 1106 btstack_memory_l2cap_channel_free(channel); 1107 } 1108 #endif 1109 break; 1110 1111 // Notify channel packet handler if they can send now 1112 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1113 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1114 l2cap_run(); // try sending signaling packets first 1115 l2cap_notify_channel_can_send(); 1116 break; 1117 1118 // HCI Connection Timeouts 1119 case L2CAP_EVENT_TIMEOUT_CHECK: 1120 handle = little_endian_read_16(packet, 2); 1121 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1122 if (hci_authentication_active_for_handle(handle)) break; 1123 hci_con_used = 0; 1124 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1125 while (btstack_linked_list_iterator_has_next(&it)){ 1126 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1127 if (channel->con_handle != handle) continue; 1128 hci_con_used = 1; 1129 break; 1130 } 1131 if (hci_con_used) break; 1132 if (!hci_can_send_command_packet_now()) break; 1133 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1134 break; 1135 1136 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1137 handle = little_endian_read_16(packet, 3); 1138 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1139 while (btstack_linked_list_iterator_has_next(&it)){ 1140 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1141 if (channel->con_handle != handle) continue; 1142 l2cap_handle_remote_supported_features_received(channel); 1143 break; 1144 } 1145 break; 1146 1147 case GAP_EVENT_SECURITY_LEVEL: 1148 handle = little_endian_read_16(packet, 2); 1149 log_info("l2cap - security level update"); 1150 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1151 while (btstack_linked_list_iterator_has_next(&it)){ 1152 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1153 if (channel->con_handle != handle) continue; 1154 1155 log_info("l2cap - state %u", channel->state); 1156 1157 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1158 gap_security_level_t required_level = channel->required_security_level; 1159 1160 switch (channel->state){ 1161 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1162 if (actual_level >= required_level){ 1163 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1164 l2cap_emit_incoming_connection(channel); 1165 } else { 1166 channel->reason = 0x0003; // security block 1167 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1168 } 1169 break; 1170 1171 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1172 if (actual_level >= required_level){ 1173 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1174 } else { 1175 // disconnnect, authentication not good enough 1176 hci_disconnect_security_block(handle); 1177 } 1178 break; 1179 1180 default: 1181 break; 1182 } 1183 } 1184 break; 1185 1186 default: 1187 break; 1188 } 1189 1190 l2cap_run(); 1191 } 1192 1193 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1194 channel->remote_sig_id = identifier; 1195 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1196 l2cap_run(); 1197 } 1198 1199 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 1200 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1201 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1202 signaling_responses[signaling_responses_pending].handle = handle; 1203 signaling_responses[signaling_responses_pending].code = code; 1204 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1205 signaling_responses[signaling_responses_pending].data = data; 1206 signaling_responses_pending++; 1207 l2cap_run(); 1208 } 1209 } 1210 1211 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1212 1213 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1214 l2cap_service_t *service = l2cap_get_service(psm); 1215 if (!service) { 1216 // 0x0002 PSM not supported 1217 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 1218 return; 1219 } 1220 1221 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1222 if (!hci_connection) { 1223 // 1224 log_error("no hci_connection for handle %u", handle); 1225 return; 1226 } 1227 1228 // alloc structure 1229 // log_info("l2cap_handle_connection_request register channel"); 1230 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 1231 psm, service->mtu, service->required_security_level); 1232 if (!channel){ 1233 // 0x0004 No resources available 1234 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 1235 return; 1236 } 1237 1238 channel->con_handle = handle; 1239 channel->remote_cid = source_cid; 1240 channel->remote_sig_id = sig_id; 1241 1242 // limit local mtu to max acl packet length - l2cap header 1243 if (channel->local_mtu > l2cap_max_mtu()) { 1244 channel->local_mtu = l2cap_max_mtu(); 1245 } 1246 1247 // set initial state 1248 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1249 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 1250 1251 // add to connections list 1252 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1253 1254 // assert security requirements 1255 gap_request_security_level(handle, channel->required_security_level); 1256 } 1257 1258 void l2cap_accept_connection(uint16_t local_cid){ 1259 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1260 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1261 if (!channel) { 1262 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1263 return; 1264 } 1265 1266 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1267 1268 // process 1269 l2cap_run(); 1270 } 1271 1272 void l2cap_decline_connection(uint16_t local_cid){ 1273 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 1274 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1275 if (!channel) { 1276 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1277 return; 1278 } 1279 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1280 channel->reason = 0x04; // no resources available 1281 l2cap_run(); 1282 } 1283 1284 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1285 1286 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1287 1288 uint16_t flags = little_endian_read_16(command, 6); 1289 if (flags & 1) { 1290 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1291 } 1292 1293 // accept the other's configuration options 1294 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1295 uint16_t pos = 8; 1296 while (pos < end_pos){ 1297 uint8_t option_hint = command[pos] >> 7; 1298 uint8_t option_type = command[pos] & 0x7f; 1299 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1300 pos++; 1301 uint8_t length = command[pos++]; 1302 // MTU { type(8): 1, len(8):2, MTU(16) } 1303 if (option_type == 1 && length == 2){ 1304 channel->remote_mtu = little_endian_read_16(command, pos); 1305 // log_info("l2cap cid 0x%02x, remote mtu %u", channel->local_cid, channel->remote_mtu); 1306 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1307 } 1308 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1309 if (option_type == 2 && length == 2){ 1310 channel->flush_timeout = little_endian_read_16(command, pos); 1311 } 1312 // check for unknown options 1313 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1314 log_info("l2cap cid %u, unknown options", channel->local_cid); 1315 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1316 } 1317 pos += length; 1318 } 1319 } 1320 1321 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1322 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1323 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1324 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1325 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 1326 if (channel->state == L2CAP_STATE_OPEN) return 0; 1327 return 1; 1328 } 1329 1330 1331 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1332 1333 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1334 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1335 uint16_t result = 0; 1336 1337 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1338 1339 // handle DISCONNECT REQUESTS seperately 1340 if (code == DISCONNECTION_REQUEST){ 1341 switch (channel->state){ 1342 case L2CAP_STATE_CONFIG: 1343 case L2CAP_STATE_OPEN: 1344 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1345 case L2CAP_STATE_WAIT_DISCONNECT: 1346 l2cap_handle_disconnect_request(channel, identifier); 1347 break; 1348 1349 default: 1350 // ignore in other states 1351 break; 1352 } 1353 return; 1354 } 1355 1356 // @STATEMACHINE(l2cap) 1357 switch (channel->state) { 1358 1359 case L2CAP_STATE_WAIT_CONNECT_RSP: 1360 switch (code){ 1361 case CONNECTION_RESPONSE: 1362 l2cap_stop_rtx(channel); 1363 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1364 switch (result) { 1365 case 0: 1366 // successful connection 1367 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1368 channel->state = L2CAP_STATE_CONFIG; 1369 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1370 break; 1371 case 1: 1372 // connection pending. get some coffee, but start the ERTX 1373 l2cap_start_ertx(channel); 1374 break; 1375 default: 1376 // channel closed 1377 channel->state = L2CAP_STATE_CLOSED; 1378 // map l2cap connection response result to BTstack status enumeration 1379 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1380 1381 // drop link key if security block 1382 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1383 gap_drop_link_key_for_bd_addr(channel->address); 1384 } 1385 1386 // discard channel 1387 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1388 btstack_memory_l2cap_channel_free(channel); 1389 break; 1390 } 1391 break; 1392 1393 default: 1394 //@TODO: implement other signaling packets 1395 break; 1396 } 1397 break; 1398 1399 case L2CAP_STATE_CONFIG: 1400 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1401 switch (code) { 1402 case CONFIGURE_REQUEST: 1403 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1404 l2cap_signaling_handle_configure_request(channel, command); 1405 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1406 // only done if continuation not set 1407 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1408 } 1409 break; 1410 case CONFIGURE_RESPONSE: 1411 l2cap_stop_rtx(channel); 1412 switch (result){ 1413 case 0: // success 1414 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1415 break; 1416 case 4: // pending 1417 l2cap_start_ertx(channel); 1418 break; 1419 default: 1420 // retry on negative result 1421 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1422 break; 1423 } 1424 break; 1425 default: 1426 break; 1427 } 1428 if (l2cap_channel_ready_for_open(channel)){ 1429 // for open: 1430 channel->state = L2CAP_STATE_OPEN; 1431 l2cap_emit_channel_opened(channel, 0); 1432 } 1433 break; 1434 1435 case L2CAP_STATE_WAIT_DISCONNECT: 1436 switch (code) { 1437 case DISCONNECTION_RESPONSE: 1438 l2cap_finialize_channel_close(channel); 1439 break; 1440 default: 1441 //@TODO: implement other signaling packets 1442 break; 1443 } 1444 break; 1445 1446 case L2CAP_STATE_CLOSED: 1447 // @TODO handle incoming requests 1448 break; 1449 1450 case L2CAP_STATE_OPEN: 1451 //@TODO: implement other signaling packets, e.g. re-configure 1452 break; 1453 default: 1454 break; 1455 } 1456 // log_info("new state %u", channel->state); 1457 } 1458 1459 1460 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1461 1462 // get code, signalind identifier and command len 1463 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1464 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1465 1466 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1467 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1468 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1469 return; 1470 } 1471 1472 // general commands without an assigned channel 1473 switch(code) { 1474 1475 case CONNECTION_REQUEST: { 1476 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1477 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1478 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1479 return; 1480 } 1481 1482 case ECHO_REQUEST: 1483 l2cap_register_signaling_response(handle, code, sig_id, 0); 1484 return; 1485 1486 case INFORMATION_REQUEST: { 1487 uint16_t infoType = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1488 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1489 return; 1490 } 1491 1492 default: 1493 break; 1494 } 1495 1496 1497 // Get potential destination CID 1498 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1499 1500 // Find channel for this sig_id and connection handle 1501 btstack_linked_list_iterator_t it; 1502 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1503 while (btstack_linked_list_iterator_has_next(&it)){ 1504 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1505 if (channel->con_handle != handle) continue; 1506 if (code & 1) { 1507 // match odd commands (responses) by previous signaling identifier 1508 if (channel->local_sig_id == sig_id) { 1509 l2cap_signaling_handler_channel(channel, command); 1510 break; 1511 } 1512 } else { 1513 // match even commands (requests) by local channel id 1514 if (channel->local_cid == dest_cid) { 1515 l2cap_signaling_handler_channel(channel, command); 1516 break; 1517 } 1518 } 1519 } 1520 } 1521 1522 #ifdef ENABLE_BLE 1523 // @returns valid 1524 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 1525 hci_connection_t * connection; 1526 uint16_t result; 1527 uint8_t event[10]; 1528 uint16_t local_cid; 1529 l2cap_channel_t * channel; 1530 btstack_linked_list_iterator_t it; 1531 1532 #ifdef ENABLE_LE_DATA_CHANNELS 1533 uint16_t le_psm; 1534 uint16_t new_credits; 1535 uint16_t credits_before; 1536 l2cap_service_t * service; 1537 #endif 1538 1539 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1540 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 1541 1542 switch (code){ 1543 1544 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 1545 result = little_endian_read_16(command, 4); 1546 l2cap_emit_connection_parameter_update_response(handle, result); 1547 break; 1548 1549 case CONNECTION_PARAMETER_UPDATE_REQUEST: 1550 connection = hci_connection_for_handle(handle); 1551 if (connection){ 1552 if (connection->role != HCI_ROLE_MASTER){ 1553 // reject command without notifying upper layer when not in master role 1554 return 0; 1555 } 1556 int update_parameter = 1; 1557 le_connection_parameter_range_t existing_range; 1558 gap_get_connection_parameter_range(&existing_range); 1559 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 1560 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 1561 uint16_t le_conn_latency = little_endian_read_16(command,12); 1562 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 1563 1564 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 1565 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 1566 1567 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 1568 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 1569 1570 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 1571 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 1572 1573 if (update_parameter){ 1574 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 1575 connection->le_conn_interval_min = le_conn_interval_min; 1576 connection->le_conn_interval_max = le_conn_interval_max; 1577 connection->le_conn_latency = le_conn_latency; 1578 connection->le_supervision_timeout = le_supervision_timeout; 1579 } else { 1580 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 1581 } 1582 connection->le_con_param_update_identifier = sig_id; 1583 } 1584 1585 if (!l2cap_event_packet_handler) break; 1586 1587 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 1588 event[1] = 8; 1589 memcpy(&event[2], &command[4], 8); 1590 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1591 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1592 break; 1593 1594 case COMMAND_REJECT: 1595 // Find channel for this sig_id and connection handle 1596 channel = NULL; 1597 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1598 while (btstack_linked_list_iterator_has_next(&it)){ 1599 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1600 if (a_channel->con_handle != handle) continue; 1601 if (a_channel->local_sig_id != sig_id) continue; 1602 channel = a_channel; 1603 break; 1604 } 1605 if (!channel) break; 1606 1607 // if received while waiting for le connection response, assume legacy device 1608 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 1609 channel->state = L2CAP_STATE_CLOSED; 1610 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 1611 l2cap_emit_le_channel_opened(channel, 0x0002); 1612 1613 // discard channel 1614 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1615 btstack_memory_l2cap_channel_free(channel); 1616 break; 1617 } 1618 break; 1619 1620 #ifdef ENABLE_LE_DATA_CHANNELS 1621 case LE_CREDIT_BASED_CONNECTION_REQUEST: 1622 1623 // get hci connection, bail if not found (must not happen) 1624 connection = hci_connection_for_handle(handle); 1625 if (!connection) return 0; 1626 1627 // check if service registered 1628 le_psm = little_endian_read_16(command, 4); 1629 service = l2cap_le_get_service(le_psm); 1630 1631 if (service){ 1632 1633 uint16_t source_cid = little_endian_read_16(command, 6); 1634 if (source_cid < 0x40){ 1635 // 0x0009 Connection refused - Invalid Source CID 1636 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0009); 1637 return 1; 1638 } 1639 1640 // go through list of channels for this ACL connection and check if we get a match 1641 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1642 while (btstack_linked_list_iterator_has_next(&it)){ 1643 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1644 if (a_channel->con_handle != handle) continue; 1645 if (a_channel->remote_cid != source_cid) continue; 1646 // 0x000a Connection refused - Source CID already allocated 1647 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x000a); 1648 return 1; 1649 } 1650 1651 // security: check encryption 1652 if (service->required_security_level >= LEVEL_2){ 1653 if (sm_encryption_key_size(handle) == 0){ 1654 // 0x0008 Connection refused - insufficient encryption 1655 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0008); 1656 return 1; 1657 } 1658 // anything less than 16 byte key size is insufficient 1659 if (sm_encryption_key_size(handle) < 16){ 1660 // 0x0007 Connection refused – insufficient encryption key size 1661 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0007); 1662 return 1; 1663 } 1664 } 1665 1666 // security: check authencation 1667 if (service->required_security_level >= LEVEL_3){ 1668 if (!sm_authenticated(handle)){ 1669 // 0x0005 Connection refused – insufficient authentication 1670 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0005); 1671 return 1; 1672 } 1673 } 1674 1675 // security: check authorization 1676 if (service->required_security_level >= LEVEL_4){ 1677 if (sm_authorization_state(handle) != AUTHORIZATION_GRANTED){ 1678 // 0x0006 Connection refused – insufficient authorization 1679 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0006); 1680 return 1; 1681 } 1682 } 1683 1684 // allocate channel 1685 channel = l2cap_create_channel_entry(service->packet_handler, connection->address, 1686 BD_ADDR_TYPE_LE_RANDOM, le_psm, service->mtu, service->required_security_level); 1687 if (!channel){ 1688 // 0x0004 Connection refused – no resources available 1689 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0004); 1690 return 1; 1691 } 1692 1693 channel->con_handle = handle; 1694 channel->remote_cid = source_cid; 1695 channel->remote_sig_id = sig_id; 1696 channel->remote_mtu = little_endian_read_16(command, 8); 1697 channel->remote_mps = little_endian_read_16(command, 10); 1698 channel->credits_outgoing = little_endian_read_16(command, 12); 1699 1700 // set initial state 1701 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1702 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_INCOMING; 1703 1704 // add to connections list 1705 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1706 1707 // post connection request event 1708 l2cap_emit_le_incoming_connection(channel); 1709 1710 } else { 1711 // Connection refused – LE_PSM not supported 1712 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0002); 1713 } 1714 break; 1715 1716 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 1717 // Find channel for this sig_id and connection handle 1718 channel = NULL; 1719 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1720 while (btstack_linked_list_iterator_has_next(&it)){ 1721 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1722 if (a_channel->con_handle != handle) continue; 1723 if (a_channel->local_sig_id != sig_id) continue; 1724 channel = a_channel; 1725 break; 1726 } 1727 if (!channel) break; 1728 1729 // cid + 0 1730 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 1731 if (result){ 1732 channel->state = L2CAP_STATE_CLOSED; 1733 // map l2cap connection response result to BTstack status enumeration 1734 l2cap_emit_le_channel_opened(channel, result); 1735 1736 // discard channel 1737 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1738 btstack_memory_l2cap_channel_free(channel); 1739 break; 1740 } 1741 1742 // success 1743 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1744 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1745 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 1746 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 1747 channel->state = L2CAP_STATE_OPEN; 1748 l2cap_emit_le_channel_opened(channel, result); 1749 break; 1750 1751 case LE_FLOW_CONTROL_CREDIT: 1752 // find channel 1753 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1754 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1755 if (!channel) { 1756 log_error("l2cap: no channel for cid 0x%02x", local_cid); 1757 break; 1758 } 1759 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1760 credits_before = channel->credits_outgoing; 1761 channel->credits_outgoing += new_credits; 1762 // check for credit overrun 1763 if (credits_before > channel->credits_outgoing){ 1764 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 1765 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1766 break; 1767 } 1768 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 1769 break; 1770 #endif 1771 1772 case DISCONNECTION_REQUEST: 1773 // find channel 1774 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1775 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1776 if (!channel) { 1777 log_error("l2cap: no channel for cid 0x%02x", local_cid); 1778 break; 1779 } 1780 channel->remote_sig_id = sig_id; 1781 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1782 break; 1783 1784 case DISCONNECTION_RESPONSE: 1785 break; 1786 1787 default: 1788 // command unknown -> reject command 1789 return 0; 1790 } 1791 return 1; 1792 } 1793 #endif 1794 1795 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 1796 1797 // Get Channel ID 1798 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1799 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1800 1801 switch (channel_id) { 1802 1803 case L2CAP_CID_SIGNALING: { 1804 uint16_t command_offset = 8; 1805 while (command_offset < size) { 1806 // handle signaling commands 1807 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1808 1809 // increment command_offset 1810 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1811 } 1812 break; 1813 } 1814 1815 #ifdef ENABLE_BLE 1816 case L2CAP_CID_SIGNALING_LE: { 1817 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1818 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 1819 if (!valid){ 1820 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1821 } 1822 break; 1823 } 1824 #endif 1825 1826 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1827 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 1828 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1829 } 1830 break; 1831 1832 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1833 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 1834 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1835 } 1836 break; 1837 1838 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 1839 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 1840 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1841 } 1842 break; 1843 1844 default: { 1845 // Find channel for this channel_id and connection handle 1846 l2cap_channel_t * l2cap_channel; 1847 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 1848 if (l2cap_channel) { 1849 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1850 } 1851 #ifdef ENABLE_BLE 1852 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 1853 if (l2cap_channel) { 1854 // credit counting 1855 if (l2cap_channel->credits_incoming == 0){ 1856 log_error("LE Data Channel packet received but no incoming credits"); 1857 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1858 break; 1859 } 1860 l2cap_channel->credits_incoming--; 1861 1862 // automatic credits 1863 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 1864 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 1865 } 1866 1867 // first fragment 1868 uint16_t pos = 0; 1869 if (!l2cap_channel->receive_sdu_len){ 1870 l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 1871 l2cap_channel->receive_sdu_pos = 0; 1872 pos += 2; 1873 size -= 2; 1874 } 1875 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); 1876 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 1877 // done? 1878 log_info("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 1879 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 1880 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 1881 l2cap_channel->receive_sdu_len = 0; 1882 } 1883 } else { 1884 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 1885 } 1886 #endif 1887 break; 1888 } 1889 } 1890 1891 l2cap_run(); 1892 } 1893 1894 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1895 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 1896 channel->state = L2CAP_STATE_CLOSED; 1897 l2cap_emit_channel_closed(channel); 1898 // discard channel 1899 l2cap_stop_rtx(channel); 1900 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1901 btstack_memory_l2cap_channel_free(channel); 1902 } 1903 1904 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 1905 btstack_linked_list_iterator_t it; 1906 btstack_linked_list_iterator_init(&it, services); 1907 while (btstack_linked_list_iterator_has_next(&it)){ 1908 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 1909 if ( service->psm == psm){ 1910 return service; 1911 }; 1912 } 1913 return NULL; 1914 } 1915 1916 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 1917 return l2cap_get_service_internal(&l2cap_services, psm); 1918 } 1919 1920 1921 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 1922 1923 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1924 1925 // check for alread registered psm 1926 l2cap_service_t *service = l2cap_get_service(psm); 1927 if (service) { 1928 log_error("l2cap_register_service: PSM %u already registered", psm); 1929 return L2CAP_SERVICE_ALREADY_REGISTERED; 1930 } 1931 1932 // alloc structure 1933 service = btstack_memory_l2cap_service_get(); 1934 if (!service) { 1935 log_error("l2cap_register_service: no memory for l2cap_service_t"); 1936 return BTSTACK_MEMORY_ALLOC_FAILED; 1937 } 1938 1939 // fill in 1940 service->psm = psm; 1941 service->mtu = mtu; 1942 service->packet_handler = service_packet_handler; 1943 service->required_security_level = security_level; 1944 1945 // add to services list 1946 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 1947 1948 // enable page scan 1949 gap_connectable_control(1); 1950 1951 return 0; 1952 } 1953 1954 uint8_t l2cap_unregister_service(uint16_t psm){ 1955 1956 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1957 1958 l2cap_service_t *service = l2cap_get_service(psm); 1959 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 1960 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 1961 btstack_memory_l2cap_service_free(service); 1962 1963 // disable page scan when no services registered 1964 if (btstack_linked_list_empty(&l2cap_services)) { 1965 gap_connectable_control(0); 1966 } 1967 return 0; 1968 } 1969 1970 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1971 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 1972 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 1973 if (index < 0) return; 1974 fixed_channels[index].callback = the_packet_handler; 1975 } 1976 1977 #ifdef ENABLE_BLE 1978 1979 #ifdef ENABLE_LE_DATA_CHANNELS 1980 1981 static void l2cap_le_notify_channel_can_send(l2cap_channel_t *channel){ 1982 if (!channel->waiting_for_can_send_now) return; 1983 if (channel->send_sdu_buffer) return; 1984 channel->waiting_for_can_send_now = 0; 1985 log_info("L2CAP_EVENT_CHANNEL_LE_CAN_SEND_NOW local_cid 0x%x", channel->local_cid); 1986 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_LE_CAN_SEND_NOW); 1987 } 1988 1989 // 1BH2222 1990 static void l2cap_emit_le_incoming_connection(l2cap_channel_t *channel) { 1991 log_info("L2CAP_EVENT_LE_INCOMING_CONNECTION addr_type %u, addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x, remote_mtu %u", 1992 channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid, channel->remote_mtu); 1993 uint8_t event[19]; 1994 event[0] = L2CAP_EVENT_LE_INCOMING_CONNECTION; 1995 event[1] = sizeof(event) - 2; 1996 event[2] = channel->address_type; 1997 reverse_bd_addr(channel->address, &event[3]); 1998 little_endian_store_16(event, 9, channel->con_handle); 1999 little_endian_store_16(event, 11, channel->psm); 2000 little_endian_store_16(event, 13, channel->local_cid); 2001 little_endian_store_16(event, 15, channel->remote_cid); 2002 little_endian_store_16(event, 17, channel->remote_mtu); 2003 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2004 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2005 } 2006 // 11BH22222 2007 static void l2cap_emit_le_channel_opened(l2cap_channel_t *channel, uint8_t status) { 2008 log_info("L2CAP_EVENT_LE_CHANNEL_OPENED status 0x%x addr_type %u addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x local_mtu %u, remote_mtu %u", 2009 status, channel->address_type, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 2010 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu); 2011 uint8_t event[23]; 2012 event[0] = L2CAP_EVENT_LE_CHANNEL_OPENED; 2013 event[1] = sizeof(event) - 2; 2014 event[2] = status; 2015 event[3] = channel->address_type; 2016 reverse_bd_addr(channel->address, &event[4]); 2017 little_endian_store_16(event, 10, channel->con_handle); 2018 event[12] = channel->state_var & L2CAP_CHANNEL_STATE_VAR_INCOMING ? 1 : 0; 2019 little_endian_store_16(event, 13, channel->psm); 2020 little_endian_store_16(event, 15, channel->local_cid); 2021 little_endian_store_16(event, 17, channel->remote_cid); 2022 little_endian_store_16(event, 19, channel->local_mtu); 2023 little_endian_store_16(event, 21, channel->remote_mtu); 2024 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 2025 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 2026 } 2027 2028 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 2029 btstack_linked_list_iterator_t it; 2030 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 2031 while (btstack_linked_list_iterator_has_next(&it)){ 2032 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 2033 if ( channel->local_cid == local_cid) { 2034 return channel; 2035 } 2036 } 2037 return NULL; 2038 } 2039 2040 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 2041 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 2042 channel->state = L2CAP_STATE_CLOSED; 2043 l2cap_emit_simple_event_with_cid(channel, L2CAP_EVENT_CHANNEL_CLOSED); 2044 // discard channel 2045 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2046 btstack_memory_l2cap_channel_free(channel); 2047 } 2048 2049 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 2050 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 2051 } 2052 2053 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 2054 2055 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 2056 2057 // check for alread registered psm 2058 l2cap_service_t *service = l2cap_le_get_service(psm); 2059 if (service) { 2060 return L2CAP_SERVICE_ALREADY_REGISTERED; 2061 } 2062 2063 // alloc structure 2064 service = btstack_memory_l2cap_service_get(); 2065 if (!service) { 2066 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 2067 return BTSTACK_MEMORY_ALLOC_FAILED; 2068 } 2069 2070 // fill in 2071 service->psm = psm; 2072 service->mtu = 0; 2073 service->packet_handler = packet_handler; 2074 service->required_security_level = security_level; 2075 2076 // add to services list 2077 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 2078 2079 // done 2080 return 0; 2081 } 2082 2083 uint8_t l2cap_le_unregister_service(uint16_t psm) { 2084 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 2085 l2cap_service_t *service = l2cap_le_get_service(psm); 2086 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2087 2088 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 2089 btstack_memory_l2cap_service_free(service); 2090 return 0; 2091 } 2092 2093 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 2094 // get channel 2095 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2096 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2097 2098 // validate state 2099 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2100 return ERROR_CODE_COMMAND_DISALLOWED; 2101 } 2102 2103 // set state accept connection 2104 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 2105 channel->receive_sdu_buffer = receive_sdu_buffer; 2106 channel->local_mtu = mtu; 2107 channel->new_credits_incoming = initial_credits; 2108 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2109 2110 // test 2111 // channel->new_credits_incoming = 1; 2112 2113 // go 2114 l2cap_run(); 2115 return 0; 2116 } 2117 2118 /** 2119 * @brief Deny incoming LE Data Channel connection due to resource constraints 2120 * @param local_cid L2CAP LE Data Channel Identifier 2121 */ 2122 2123 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 2124 // get channel 2125 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2126 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2127 2128 // validate state 2129 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2130 return ERROR_CODE_COMMAND_DISALLOWED; 2131 } 2132 2133 // set state decline connection 2134 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 2135 channel->reason = 0x04; // no resources available 2136 l2cap_run(); 2137 return 0; 2138 } 2139 2140 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, hci_con_handle_t con_handle, 2141 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 2142 uint16_t * out_local_cid) { 2143 2144 log_info("L2CAP_LE_CREATE_CHANNEL handle 0x%04x psm 0x%x mtu %u", con_handle, psm, mtu); 2145 2146 2147 hci_connection_t * connection = hci_connection_for_handle(con_handle); 2148 if (!connection) { 2149 log_error("no hci_connection for handle 0x%04x", con_handle); 2150 return ERROR_CODE_UNKNOWN_CONNECTION_IDENTIFIER; 2151 } 2152 2153 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, connection->address, connection->address_type, psm, mtu, security_level); 2154 if (!channel) { 2155 return BTSTACK_MEMORY_ALLOC_FAILED; 2156 } 2157 log_info("l2cap_le_create_channel %p", channel); 2158 2159 // store local_cid 2160 if (out_local_cid){ 2161 *out_local_cid = channel->local_cid; 2162 } 2163 2164 // provide buffer 2165 channel->con_handle = con_handle; 2166 channel->receive_sdu_buffer = receive_sdu_buffer; 2167 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 2168 channel->new_credits_incoming = initial_credits; 2169 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2170 2171 // add to connections list 2172 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2173 2174 // go 2175 l2cap_run(); 2176 return 0; 2177 } 2178 2179 /** 2180 * @brief Provide credtis for LE Data Channel 2181 * @param local_cid L2CAP LE Data Channel Identifier 2182 * @param credits Number additional credits for peer 2183 */ 2184 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 2185 2186 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2187 if (!channel) { 2188 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2189 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2190 } 2191 2192 // check state 2193 if (channel->state != L2CAP_STATE_OPEN){ 2194 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 2195 } 2196 2197 // assert incoming credits + credits <= 0xffff 2198 uint32_t total_credits = channel->credits_incoming; 2199 total_credits += channel->new_credits_incoming; 2200 total_credits += credits; 2201 if (total_credits > 0xffff){ 2202 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 2203 channel->new_credits_incoming, credits); 2204 } 2205 2206 // set credits_granted 2207 channel->new_credits_incoming += credits; 2208 2209 // go 2210 l2cap_run(); 2211 return 0; 2212 } 2213 2214 /** 2215 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 2216 * @param local_cid L2CAP LE Data Channel Identifier 2217 */ 2218 int l2cap_le_can_send_now(uint16_t local_cid){ 2219 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2220 if (!channel) { 2221 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2222 return 0; 2223 } 2224 2225 // check state 2226 if (channel->state != L2CAP_STATE_OPEN) return 0; 2227 2228 // check queue 2229 if (channel->send_sdu_buffer) return 0; 2230 2231 // fine, go ahead 2232 return 1; 2233 } 2234 2235 /** 2236 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 2237 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 2238 * so packet handler should be ready to handle it 2239 * @param local_cid L2CAP LE Data Channel Identifier 2240 */ 2241 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 2242 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2243 if (!channel) { 2244 log_error("l2cap_le_request_can_send_now_event no channel for cid 0x%02x", local_cid); 2245 return 0; 2246 } 2247 channel->waiting_for_can_send_now = 1; 2248 l2cap_le_notify_channel_can_send(channel); 2249 return 0; 2250 } 2251 2252 /** 2253 * @brief Send data via LE Data Channel 2254 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 2255 * @param local_cid L2CAP LE Data Channel Identifier 2256 * @param data data to send 2257 * @param size data size 2258 */ 2259 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 2260 2261 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2262 if (!channel) { 2263 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2264 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2265 } 2266 2267 if (len > channel->remote_mtu){ 2268 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 2269 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 2270 } 2271 2272 if (channel->send_sdu_buffer){ 2273 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 2274 return BTSTACK_ACL_BUFFERS_FULL; 2275 } 2276 2277 channel->send_sdu_buffer = data; 2278 channel->send_sdu_len = len; 2279 channel->send_sdu_pos = 0; 2280 2281 l2cap_run(); 2282 return 0; 2283 } 2284 2285 /** 2286 * @brief Disconnect from LE Data Channel 2287 * @param local_cid L2CAP LE Data Channel Identifier 2288 */ 2289 uint8_t l2cap_le_disconnect(uint16_t local_cid) 2290 { 2291 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2292 if (!channel) { 2293 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2294 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2295 } 2296 2297 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2298 l2cap_run(); 2299 return 0; 2300 } 2301 2302 #endif 2303 2304 #endif 2305