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