1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at 34 * [email protected] 35 * 36 */ 37 38 /* 39 * l2cap.c 40 * 41 * Logical Link Control and Adaption Protocl (L2CAP) 42 * 43 * Created by Matthias Ringwald on 5/16/09. 44 */ 45 46 #include "l2cap.h" 47 #include "hci.h" 48 #include "hci_dump.h" 49 #include "btstack_debug.h" 50 #include "btstack_event.h" 51 #include "btstack_memory.h" 52 53 #include <stdarg.h> 54 #include <string.h> 55 56 #include <stdio.h> 57 58 // nr of buffered acl packets in outgoing queue to get max performance 59 #define NR_BUFFERED_ACL_PACKETS 3 60 61 // used to cache l2cap rejects, echo, and informational requests 62 #define NR_PENDING_SIGNALING_RESPONSES 3 63 64 // nr of credits provided to remote if credits fall below watermark 65 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK 5 66 #define L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT 5 67 68 // offsets for L2CAP SIGNALING COMMANDS 69 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 70 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 71 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 72 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 73 74 // internal table 75 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL 0 76 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL 1 77 #define L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL 2 78 #define L2CAP_FIXED_CHANNEL_TABLE_SIZE (L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL+1) 79 80 // prototypes 81 static void l2cap_finialize_channel_close(l2cap_channel_t *channel); 82 static inline l2cap_service_t * l2cap_get_service(uint16_t psm); 83 static void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status); 84 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel); 85 static void l2cap_emit_channel_closed(l2cap_channel_t *channel); 86 static void l2cap_emit_connection_request(l2cap_channel_t *channel); 87 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); 88 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); 89 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ); 90 static void l2cap_notify_channel_can_send(void); 91 #ifdef ENABLE_BLE 92 static void l2cap_le_finialize_channel_close(l2cap_channel_t *channel); 93 static inline l2cap_service_t * l2cap_le_get_service(uint16_t psm); 94 #endif 95 96 typedef struct l2cap_fixed_channel { 97 btstack_packet_handler_t callback; 98 uint8_t waiting_for_can_send_now; 99 } l2cap_fixed_channel_t; 100 101 static btstack_linked_list_t l2cap_channels; 102 static btstack_linked_list_t l2cap_services; 103 static btstack_linked_list_t l2cap_le_channels; 104 static btstack_linked_list_t l2cap_le_services; 105 106 // used to cache l2cap rejects, echo, and informational requests 107 static l2cap_signaling_response_t signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; 108 static int signaling_responses_pending; 109 110 static uint8_t require_security_level2_for_outgoing_sdp; 111 112 static btstack_packet_callback_registration_t hci_event_callback_registration; 113 114 static btstack_packet_handler_t l2cap_event_packet_handler; 115 static l2cap_fixed_channel_t fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_SIZE]; 116 117 static uint16_t l2cap_fixed_channel_table_channel_id_for_index(int index){ 118 switch (index){ 119 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL: 120 return L2CAP_CID_ATTRIBUTE_PROTOCOL; 121 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL: 122 return L2CAP_CID_SECURITY_MANAGER_PROTOCOL; 123 case L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL: 124 return L2CAP_CID_CONNECTIONLESS_CHANNEL; 125 default: 126 return 0; 127 } 128 } 129 static int l2cap_fixed_channel_table_index_for_channel_id(uint16_t channel_id){ 130 switch (channel_id){ 131 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 132 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL; 133 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 134 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL; 135 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 136 return L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL; 137 default: 138 return -1; 139 } 140 } 141 142 static int l2cap_fixed_channel_table_index_is_le(int index){ 143 if (index == L2CAP_CID_CONNECTIONLESS_CHANNEL) return 0; 144 return 1; 145 } 146 147 void l2cap_init(void){ 148 signaling_responses_pending = 0; 149 150 l2cap_channels = NULL; 151 l2cap_services = NULL; 152 l2cap_le_services = NULL; 153 l2cap_le_channels = NULL; 154 155 l2cap_event_packet_handler = NULL; 156 memset(fixed_channels, 0, sizeof(fixed_channels)); 157 158 require_security_level2_for_outgoing_sdp = 0; 159 160 // 161 // register callback with HCI 162 // 163 hci_event_callback_registration.callback = &l2cap_hci_event_handler; 164 hci_add_event_handler(&hci_event_callback_registration); 165 166 hci_register_acl_packet_handler(&l2cap_acl_handler); 167 168 gap_connectable_control(0); // no services yet 169 } 170 171 void l2cap_register_packet_handler(void (*handler)(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 172 l2cap_event_packet_handler = handler; 173 } 174 175 static void l2cap_dispatch_to_channel(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 176 (* (channel->packet_handler))(type, channel->local_cid, data, size); 177 } 178 179 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 180 log_info("L2CAP_EVENT_CHANNEL_OPENED status 0x%x addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x local_mtu %u, remote_mtu %u, flush_timeout %u", 181 status, bd_addr_to_str(channel->address), channel->con_handle, channel->psm, 182 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 183 uint8_t event[23]; 184 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 185 event[1] = sizeof(event) - 2; 186 event[2] = status; 187 reverse_bd_addr(channel->address, &event[3]); 188 little_endian_store_16(event, 9, channel->con_handle); 189 little_endian_store_16(event, 11, channel->psm); 190 little_endian_store_16(event, 13, channel->local_cid); 191 little_endian_store_16(event, 15, channel->remote_cid); 192 little_endian_store_16(event, 17, channel->local_mtu); 193 little_endian_store_16(event, 19, channel->remote_mtu); 194 little_endian_store_16(event, 21, channel->flush_timeout); 195 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 196 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 197 } 198 199 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 200 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 201 uint8_t event[4]; 202 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 203 event[1] = sizeof(event) - 2; 204 little_endian_store_16(event, 2, channel->local_cid); 205 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 206 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 207 } 208 209 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 210 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 211 bd_addr_to_str(channel->address), channel->con_handle, channel->psm, channel->local_cid, channel->remote_cid); 212 uint8_t event[16]; 213 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 214 event[1] = sizeof(event) - 2; 215 reverse_bd_addr(channel->address, &event[2]); 216 little_endian_store_16(event, 8, channel->con_handle); 217 little_endian_store_16(event, 10, channel->psm); 218 little_endian_store_16(event, 12, channel->local_cid); 219 little_endian_store_16(event, 14, channel->remote_cid); 220 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 221 l2cap_dispatch_to_channel(channel, HCI_EVENT_PACKET, event, sizeof(event)); 222 } 223 224 static void l2cap_emit_can_send_now(btstack_packet_handler_t packet_handler, uint16_t channel) { 225 log_info("L2CAP_EVENT_CHANNEL_CAN_SEND_NOW local_cid 0x%x", channel); 226 uint8_t event[4]; 227 event[0] = L2CAP_EVENT_CAN_SEND_NOW; 228 event[1] = sizeof(event) - 2; 229 little_endian_store_16(event, 2, channel); 230 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 231 packet_handler(HCI_EVENT_PACKET, channel, event, sizeof(event)); 232 } 233 234 static void l2cap_emit_connection_parameter_update_response(hci_con_handle_t con_handle, uint16_t result){ 235 uint8_t event[6]; 236 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 237 event[1] = 4; 238 little_endian_store_16(event, 2, con_handle); 239 little_endian_store_16(event, 4, result); 240 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 241 if (!l2cap_event_packet_handler) return; 242 (*l2cap_event_packet_handler)(HCI_EVENT_PACKET, 0, event, sizeof(event)); 243 } 244 245 static l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 246 btstack_linked_list_iterator_t it; 247 btstack_linked_list_iterator_init(&it, &l2cap_channels); 248 while (btstack_linked_list_iterator_has_next(&it)){ 249 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 250 if ( channel->local_cid == local_cid) { 251 return channel; 252 } 253 } 254 return NULL; 255 } 256 257 #ifdef ENABLE_BLE 258 static l2cap_channel_t * l2cap_le_get_channel_for_local_cid(uint16_t local_cid){ 259 btstack_linked_list_iterator_t it; 260 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 261 while (btstack_linked_list_iterator_has_next(&it)){ 262 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 263 if ( channel->local_cid == local_cid) { 264 return channel; 265 } 266 } 267 return NULL; 268 } 269 #endif 270 271 static l2cap_channel_t * l2cap_get_le_channel_for_address_and_addr_type(bd_addr_t address, bd_addr_type_t address_type){ 272 btstack_linked_list_iterator_t it; 273 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 274 while (btstack_linked_list_iterator_has_next(&it)){ 275 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 276 if (channel->address_type != address_type) continue; 277 if (bd_addr_cmp(channel->address, address)) continue; 278 return channel; 279 } 280 return NULL; 281 } 282 283 /// 284 285 void l2cap_request_can_send_now_event(uint16_t local_cid){ 286 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 287 if (!channel) return; 288 channel->waiting_for_can_send_now = 1; 289 l2cap_notify_channel_can_send(); 290 } 291 292 void l2cap_request_can_send_fix_channel_now_event(hci_con_handle_t con_handle, uint16_t channel_id){ 293 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 294 if (index < 0) return; 295 fixed_channels[index].waiting_for_can_send_now = 1; 296 l2cap_notify_channel_can_send(); 297 } 298 299 /// 300 301 int l2cap_can_send_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_acl_packet_now(channel->con_handle); 305 } 306 307 int l2cap_can_send_prepared_packet_now(uint16_t local_cid){ 308 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 309 if (!channel) return 0; 310 return hci_can_send_prepared_acl_packet_now(channel->con_handle); 311 } 312 313 int l2cap_can_send_fixed_channel_packet_now(hci_con_handle_t con_handle, uint16_t channel_id){ 314 return hci_can_send_acl_packet_now(con_handle); 315 } 316 317 /// 318 319 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 320 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 321 if (channel) { 322 return channel->remote_mtu; 323 } 324 return 0; 325 } 326 327 static l2cap_channel_t * l2cap_channel_for_rtx_timer(btstack_timer_source_t * ts){ 328 btstack_linked_list_iterator_t it; 329 btstack_linked_list_iterator_init(&it, &l2cap_channels); 330 while (btstack_linked_list_iterator_has_next(&it)){ 331 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 332 if ( &channel->rtx == ts) { 333 return channel; 334 } 335 } 336 return NULL; 337 } 338 339 static void l2cap_rtx_timeout(btstack_timer_source_t * ts){ 340 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 341 if (!channel) return; 342 343 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 344 345 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 346 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 347 // notify client 348 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 349 350 // discard channel 351 // no need to stop timer here, it is removed from list during timer callback 352 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 353 btstack_memory_l2cap_channel_free(channel); 354 } 355 356 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 357 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 358 btstack_run_loop_remove_timer(&channel->rtx); 359 } 360 361 static void l2cap_start_rtx(l2cap_channel_t * channel){ 362 l2cap_stop_rtx(channel); 363 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 364 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 365 btstack_run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 366 btstack_run_loop_add_timer(&channel->rtx); 367 } 368 369 static void l2cap_start_ertx(l2cap_channel_t * channel){ 370 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 371 l2cap_stop_rtx(channel); 372 btstack_run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 373 btstack_run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 374 btstack_run_loop_add_timer(&channel->rtx); 375 } 376 377 void l2cap_require_security_level_2_for_outgoing_sdp(void){ 378 require_security_level2_for_outgoing_sdp = 1; 379 } 380 381 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 382 return (psm == PSM_SDP) && (!require_security_level2_for_outgoing_sdp); 383 } 384 385 static int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 386 387 if (!hci_can_send_acl_packet_now(handle)){ 388 log_info("l2cap_send_signaling_packet, cannot send"); 389 return BTSTACK_ACL_BUFFERS_FULL; 390 } 391 392 // log_info("l2cap_send_signaling_packet type %u", cmd); 393 hci_reserve_packet_buffer(); 394 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 395 va_list argptr; 396 va_start(argptr, identifier); 397 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 398 va_end(argptr); 399 // log_info("l2cap_send_signaling_packet con %u!", handle); 400 return hci_send_acl_packet_buffer(len); 401 } 402 403 #ifdef ENABLE_BLE 404 static int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 405 406 if (!hci_can_send_acl_packet_now(handle)){ 407 log_info("l2cap_send_signaling_packet, cannot send"); 408 return BTSTACK_ACL_BUFFERS_FULL; 409 } 410 411 // log_info("l2cap_send_signaling_packet type %u", cmd); 412 hci_reserve_packet_buffer(); 413 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 414 va_list argptr; 415 va_start(argptr, identifier); 416 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 417 va_end(argptr); 418 // log_info("l2cap_send_signaling_packet con %u!", handle); 419 return hci_send_acl_packet_buffer(len); 420 } 421 #endif 422 423 uint8_t *l2cap_get_outgoing_buffer(void){ 424 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 425 } 426 427 int l2cap_reserve_packet_buffer(void){ 428 return hci_reserve_packet_buffer(); 429 } 430 431 void l2cap_release_packet_buffer(void){ 432 hci_release_packet_buffer(); 433 } 434 435 static void l2cap_setup_header(uint8_t * acl_buffer, hci_con_handle_t con_handle, uint16_t remote_cid, uint16_t len){ 436 437 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 438 439 // 0 - Connection handle : PB=pb : BC=00 440 little_endian_store_16(acl_buffer, 0, con_handle | (pb << 12) | (0 << 14)); 441 // 2 - ACL length 442 little_endian_store_16(acl_buffer, 2, len + 4); 443 // 4 - L2CAP packet length 444 little_endian_store_16(acl_buffer, 4, len + 0); 445 // 6 - L2CAP channel DEST 446 little_endian_store_16(acl_buffer, 6, remote_cid); 447 } 448 449 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 450 451 if (!hci_is_packet_buffer_reserved()){ 452 log_error("l2cap_send_prepared called without reserving packet first"); 453 return BTSTACK_ACL_BUFFERS_FULL; 454 } 455 456 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 457 if (!channel) { 458 log_error("l2cap_send_prepared no channel for cid 0x%02x", local_cid); 459 return -1; // TODO: define error 460 } 461 462 if (!hci_can_send_prepared_acl_packet_now(channel->con_handle)){ 463 log_info("l2cap_send_prepared cid 0x%02x, cannot send", local_cid); 464 return BTSTACK_ACL_BUFFERS_FULL; 465 } 466 467 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used", local_cid, channel->con_handle); 468 469 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 470 l2cap_setup_header(acl_buffer, channel->con_handle, channel->remote_cid, len); 471 // send 472 return hci_send_acl_packet_buffer(len+8); 473 } 474 475 int l2cap_send_prepared_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint16_t len){ 476 477 if (!hci_is_packet_buffer_reserved()){ 478 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 479 return BTSTACK_ACL_BUFFERS_FULL; 480 } 481 482 if (!hci_can_send_prepared_acl_packet_now(con_handle)){ 483 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send", con_handle, cid); 484 return BTSTACK_ACL_BUFFERS_FULL; 485 } 486 487 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x", con_handle, cid); 488 489 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 490 l2cap_setup_header(acl_buffer, con_handle, cid, len); 491 // send 492 return hci_send_acl_packet_buffer(len+8); 493 } 494 495 int l2cap_send(uint16_t local_cid, uint8_t *data, uint16_t len){ 496 497 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 498 if (!channel) { 499 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 500 return -1; // TODO: define error 501 } 502 503 if (len > channel->remote_mtu){ 504 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 505 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 506 } 507 508 if (!hci_can_send_acl_packet_now(channel->con_handle)){ 509 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 510 return BTSTACK_ACL_BUFFERS_FULL; 511 } 512 513 hci_reserve_packet_buffer(); 514 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 515 516 memcpy(&acl_buffer[8], data, len); 517 518 return l2cap_send_prepared(local_cid, len); 519 } 520 521 int l2cap_send_connectionless(hci_con_handle_t con_handle, uint16_t cid, uint8_t *data, uint16_t len){ 522 523 if (!hci_can_send_acl_packet_now(con_handle)){ 524 log_info("l2cap_send cid 0x%02x, cannot send", cid); 525 return BTSTACK_ACL_BUFFERS_FULL; 526 } 527 528 hci_reserve_packet_buffer(); 529 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 530 531 memcpy(&acl_buffer[8], data, len); 532 533 return l2cap_send_prepared_connectionless(con_handle, cid, len); 534 } 535 536 int l2cap_send_echo_request(hci_con_handle_t con_handle, uint8_t *data, uint16_t len){ 537 return l2cap_send_signaling_packet(con_handle, ECHO_REQUEST, 0x77, len, data); 538 } 539 540 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 541 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 542 } 543 544 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 545 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 546 } 547 548 549 550 // MARK: L2CAP_RUN 551 // process outstanding signaling tasks 552 static void l2cap_run(void){ 553 554 // log_info("l2cap_run: entered"); 555 556 // check pending signaling responses 557 while (signaling_responses_pending){ 558 559 hci_con_handle_t handle = signaling_responses[0].handle; 560 561 if (!hci_can_send_acl_packet_now(handle)) break; 562 563 uint8_t sig_id = signaling_responses[0].sig_id; 564 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 565 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 566 uint8_t response_code = signaling_responses[0].code; 567 568 // remove first item before sending (to avoid sending response mutliple times) 569 signaling_responses_pending--; 570 int i; 571 for (i=0; i < signaling_responses_pending; i++){ 572 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 573 } 574 575 switch (response_code){ 576 case CONNECTION_REQUEST: 577 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 578 // also disconnect if result is 0x0003 - security blocked 579 if (result == 0x0003){ 580 hci_disconnect_security_block(handle); 581 } 582 break; 583 case ECHO_REQUEST: 584 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 585 break; 586 case INFORMATION_REQUEST: 587 switch (infoType){ 588 case 1: { // Connectionless MTU 589 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 590 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 591 break; 592 } 593 case 2: { // Extended Features Supported 594 // extended features request supported, features: fixed channels, unicast connectionless data reception 595 uint32_t features = 0x280; 596 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 597 break; 598 } 599 case 3: { // Fixed Channels Supported 600 uint8_t map[8]; 601 memset(map, 0, 8); 602 map[0] = 0x06; // L2CAP Signaling Channel (0x02) + Connectionless reception (0x04) 603 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 604 break; 605 } 606 default: 607 // all other types are not supported 608 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 609 break; 610 } 611 break; 612 case COMMAND_REJECT: 613 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 614 break; 615 #ifdef ENABLE_BLE 616 case LE_CREDIT_BASED_CONNECTION_REQUEST: 617 l2cap_send_le_signaling_packet(handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, sig_id, 0, 0, 0, 0, result); 618 break; 619 case COMMAND_REJECT_LE: 620 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 621 break; 622 #endif 623 default: 624 // should not happen 625 break; 626 } 627 } 628 629 uint8_t config_options[4]; 630 btstack_linked_list_iterator_t it; 631 btstack_linked_list_iterator_init(&it, &l2cap_channels); 632 while (btstack_linked_list_iterator_has_next(&it)){ 633 634 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 635 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 636 switch (channel->state){ 637 638 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 639 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 640 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 641 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 642 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 643 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 644 } 645 break; 646 647 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 648 if (!hci_can_send_command_packet_now()) break; 649 // send connection request - set state first 650 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 651 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 652 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 653 break; 654 655 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 656 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 657 channel->state = L2CAP_STATE_INVALID; 658 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 659 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 660 l2cap_stop_rtx(channel); 661 btstack_linked_list_iterator_remove(&it); 662 btstack_memory_l2cap_channel_free(channel); 663 break; 664 665 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 666 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 667 channel->state = L2CAP_STATE_CONFIG; 668 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 669 l2cap_send_signaling_packet(channel->con_handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 670 break; 671 672 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 673 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 674 // success, start l2cap handshake 675 channel->local_sig_id = l2cap_next_sig_id(); 676 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 677 l2cap_send_signaling_packet( channel->con_handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 678 l2cap_start_rtx(channel); 679 break; 680 681 case L2CAP_STATE_CONFIG: 682 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 683 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 684 uint16_t flags = 0; 685 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 686 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 687 flags = 1; 688 } else { 689 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 690 } 691 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 692 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 693 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 694 config_options[0] = 1; // MTU 695 config_options[1] = 2; // len param 696 little_endian_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 697 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 698 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 699 } else { 700 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 701 } 702 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 703 } 704 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 705 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 706 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 707 channel->local_sig_id = l2cap_next_sig_id(); 708 config_options[0] = 1; // MTU 709 config_options[1] = 2; // len param 710 little_endian_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 711 l2cap_send_signaling_packet(channel->con_handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 712 l2cap_start_rtx(channel); 713 } 714 if (l2cap_channel_ready_for_open(channel)){ 715 channel->state = L2CAP_STATE_OPEN; 716 l2cap_emit_channel_opened(channel, 0); // success 717 } 718 break; 719 720 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 721 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 722 channel->state = L2CAP_STATE_INVALID; 723 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 724 // 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 :) 725 l2cap_finialize_channel_close(channel); // -- remove from list 726 break; 727 728 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 729 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 730 channel->local_sig_id = l2cap_next_sig_id(); 731 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 732 l2cap_send_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 733 break; 734 default: 735 break; 736 } 737 } 738 739 #ifdef ENABLE_BLE 740 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 741 while (btstack_linked_list_iterator_has_next(&it)){ 742 uint8_t * acl_buffer; 743 uint8_t * l2cap_payload; 744 uint16_t pos; 745 uint16_t payload_size; 746 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 747 // log_info("l2cap_run: channel %p, state %u, var 0x%02x", channel, channel->state, channel->state_var); 748 switch (channel->state){ 749 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST: 750 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 751 channel->state = L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE; 752 // le psm, source cid, mtu, mps, initial credits 753 channel->local_sig_id = l2cap_next_sig_id(); 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_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid, channel->local_mtu, 23, channel->credits_incoming); 757 break; 758 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT: 759 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 760 // TODO: support larger MPS 761 channel->state = L2CAP_STATE_OPEN; 762 channel->credits_incoming = channel->new_credits_incoming; 763 channel->new_credits_incoming = 0; 764 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); 765 // notify client 766 l2cap_emit_channel_opened(channel, 0); 767 break; 768 case L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE: 769 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 770 channel->state = L2CAP_STATE_INVALID; 771 l2cap_send_le_signaling_packet(channel->con_handle, LE_CREDIT_BASED_CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, 0, 0, channel->reason); 772 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 773 l2cap_stop_rtx(channel); 774 btstack_linked_list_iterator_remove(&it); 775 btstack_memory_l2cap_channel_free(channel); 776 break; 777 case L2CAP_STATE_OPEN: 778 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 779 780 // send credits 781 if (channel->new_credits_incoming){ 782 log_info("l2cap: sending %u credits", channel->new_credits_incoming); 783 channel->local_sig_id = l2cap_next_sig_id(); 784 uint16_t new_credits = channel->new_credits_incoming; 785 channel->new_credits_incoming = 0; 786 channel->credits_incoming += new_credits; 787 l2cap_send_le_signaling_packet(channel->con_handle, LE_FLOW_CONTROL_CREDIT, channel->local_sig_id, channel->remote_cid, new_credits); 788 break; 789 } 790 791 // send data 792 if (!channel->send_sdu_buffer) break; 793 if (!channel->credits_outgoing) break; 794 795 // send part of SDU 796 hci_reserve_packet_buffer(); 797 acl_buffer = hci_get_outgoing_packet_buffer(); 798 l2cap_payload = acl_buffer + 8; 799 pos = 0; 800 if (!channel->send_sdu_pos){ 801 // store SDU len 802 channel->send_sdu_pos += 2; 803 little_endian_store_16(l2cap_payload, pos, channel->send_sdu_len); 804 pos += 2; 805 } 806 payload_size = btstack_min(channel->send_sdu_len + 2 - channel->send_sdu_pos, channel->remote_mps - pos); 807 log_info("len %u, pos %u => payload %u, credits %u", channel->send_sdu_len, channel->send_sdu_pos, payload_size, channel->credits_outgoing); 808 memcpy(&l2cap_payload[pos], &channel->send_sdu_buffer[channel->send_sdu_pos-2], payload_size); // -2 for virtual SDU len 809 pos += payload_size; 810 channel->send_sdu_pos += payload_size; 811 l2cap_setup_header(acl_buffer, channel->con_handle, channel->remote_cid, pos); 812 // done 813 814 channel->credits_outgoing--; 815 816 if (channel->send_sdu_pos >= channel->send_sdu_len + 2){ 817 channel->send_sdu_buffer = NULL; 818 // TODO: send done event 819 } 820 hci_send_acl_packet_buffer(8 + pos); 821 break; 822 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 823 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 824 channel->local_sig_id = l2cap_next_sig_id(); 825 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 826 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 827 break; 828 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 829 if (!hci_can_send_acl_packet_now(channel->con_handle)) break; 830 channel->state = L2CAP_STATE_INVALID; 831 l2cap_send_le_signaling_packet( channel->con_handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 832 l2cap_le_finialize_channel_close(channel); // -- remove from list 833 break; 834 default: 835 break; 836 } 837 } 838 839 // send l2cap con paramter update if necessary 840 hci_connections_get_iterator(&it); 841 while(btstack_linked_list_iterator_has_next(&it)){ 842 hci_connection_t * connection = (hci_connection_t *) btstack_linked_list_iterator_next(&it); 843 if (connection->address_type != BD_ADDR_TYPE_LE_PUBLIC && connection->address_type != BD_ADDR_TYPE_LE_RANDOM) continue; 844 if (!hci_can_send_acl_packet_now(connection->con_handle)) continue; 845 switch (connection->le_con_parameter_update_state){ 846 case CON_PARAMETER_UPDATE_SEND_REQUEST: 847 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 848 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_REQUEST, connection->le_con_param_update_identifier, 849 connection->le_conn_interval_min, connection->le_conn_interval_max, connection->le_conn_latency, connection->le_supervision_timeout); 850 break; 851 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 852 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 853 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 0); 854 break; 855 case CON_PARAMETER_UPDATE_DENY: 856 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_NONE; 857 l2cap_send_le_signaling_packet(connection->con_handle, CONNECTION_PARAMETER_UPDATE_RESPONSE, connection->le_con_param_update_identifier, 1); 858 break; 859 default: 860 break; 861 } 862 } 863 #endif 864 865 // log_info("l2cap_run: exit"); 866 } 867 868 uint16_t l2cap_max_mtu(void){ 869 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 870 } 871 872 uint16_t l2cap_max_le_mtu(void){ 873 return l2cap_max_mtu(); 874 } 875 876 static void l2cap_handle_connection_complete(hci_con_handle_t con_handle, l2cap_channel_t * channel){ 877 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 878 log_info("l2cap_handle_connection_complete expected state"); 879 // success, start l2cap handshake 880 channel->con_handle = con_handle; 881 // check remote SSP feature first 882 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 883 } 884 } 885 886 #ifdef ENABLE_BLE 887 static void l2cap_handle_le_connection_complete(l2cap_channel_t * channel, uint8_t status, hci_con_handle_t con_handle){ 888 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 889 log_info("l2cap_le_handle_connection_complete expected state"); 890 // TODO: bail if status != 0 891 892 // success, start l2cap handshake 893 channel->con_handle = con_handle; 894 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_REQUEST; 895 } 896 } 897 #endif 898 899 900 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 901 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 902 903 // we have been waiting for remote supported features, if both support SSP, 904 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)); 905 if (gap_ssp_supported_on_both_sides(channel->con_handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 906 // request security level 2 907 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 908 gap_request_security_level(channel->con_handle, LEVEL_2); 909 return; 910 } 911 // fine, go ahead 912 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 913 } 914 915 static l2cap_channel_t * l2cap_create_channel_entry(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 916 uint16_t psm, uint16_t local_mtu, gap_security_level_t security_level){ 917 918 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 919 if (!channel) { 920 return NULL; 921 } 922 923 // Init memory (make valgrind happy) 924 memset(channel, 0, sizeof(l2cap_channel_t)); 925 926 // fill in 927 channel->packet_handler = packet_handler; 928 bd_addr_copy(channel->address, address); 929 channel->address_type = address_type; 930 channel->psm = psm; 931 channel->local_mtu = local_mtu; 932 channel->remote_mtu = L2CAP_MINIMAL_MTU; 933 channel->required_security_level = security_level; 934 935 // 936 channel->local_cid = l2cap_next_local_cid(); 937 channel->con_handle = 0; 938 939 // set initial state 940 channel->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 941 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 942 channel->remote_sig_id = L2CAP_SIG_ID_INVALID; 943 channel->local_sig_id = L2CAP_SIG_ID_INVALID; 944 return channel; 945 } 946 947 /** 948 * @brief Creates L2CAP channel to the PSM of a remote device with baseband address. A new baseband connection will be initiated if necessary. 949 * @param packet_handler 950 * @param address 951 * @param psm 952 * @param mtu 953 * @param local_cid 954 */ 955 956 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){ 957 log_info("L2CAP_CREATE_CHANNEL addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, local_mtu); 958 959 if (local_mtu > l2cap_max_mtu()) { 960 local_mtu = l2cap_max_mtu(); 961 } 962 963 l2cap_channel_t * channel = l2cap_create_channel_entry(channel_packet_handler, address, BD_ADDR_TYPE_CLASSIC, psm, local_mtu, LEVEL_0); 964 if (!channel) { 965 return BTSTACK_MEMORY_ALLOC_FAILED; 966 } 967 968 // add to connections list 969 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 970 971 // store local_cid 972 if (out_local_cid){ 973 *out_local_cid = channel->local_cid; 974 } 975 976 // check if hci connection is already usable 977 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, BD_ADDR_TYPE_CLASSIC); 978 if (conn){ 979 log_info("l2cap_create_channel, hci connection already exists"); 980 l2cap_handle_connection_complete(conn->con_handle, channel); 981 // check if remote supported fearures are already received 982 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 983 l2cap_handle_remote_supported_features_received(channel); 984 } 985 } 986 987 l2cap_run(); 988 989 return 0; 990 } 991 992 void 993 l2cap_disconnect(uint16_t local_cid, uint8_t reason){ 994 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 995 // find channel for local_cid 996 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 997 if (channel) { 998 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 999 } 1000 // process 1001 l2cap_run(); 1002 } 1003 1004 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 1005 btstack_linked_list_iterator_t it; 1006 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1007 while (btstack_linked_list_iterator_has_next(&it)){ 1008 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1009 if ( bd_addr_cmp( channel->address, address) != 0) continue; 1010 // channel for this address found 1011 switch (channel->state){ 1012 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 1013 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 1014 // failure, forward error code 1015 l2cap_emit_channel_opened(channel, status); 1016 // discard channel 1017 l2cap_stop_rtx(channel); 1018 btstack_linked_list_iterator_remove(&it); 1019 btstack_memory_l2cap_channel_free(channel); 1020 break; 1021 default: 1022 break; 1023 } 1024 } 1025 } 1026 1027 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 1028 btstack_linked_list_iterator_t it; 1029 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1030 while (btstack_linked_list_iterator_has_next(&it)){ 1031 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1032 if ( ! bd_addr_cmp( channel->address, address) ){ 1033 l2cap_handle_connection_complete(handle, channel); 1034 } 1035 } 1036 // process 1037 l2cap_run(); 1038 } 1039 1040 static void l2cap_notify_channel_can_send(void){ 1041 btstack_linked_list_iterator_t it; 1042 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1043 while (btstack_linked_list_iterator_has_next(&it)){ 1044 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1045 if (!channel->waiting_for_can_send_now) continue; 1046 if (!hci_can_send_acl_packet_now(channel->con_handle)) continue; 1047 channel->waiting_for_can_send_now = 0; 1048 l2cap_emit_can_send_now(channel->packet_handler, channel->local_cid); 1049 } 1050 1051 int i; 1052 for (i=0;i<L2CAP_FIXED_CHANNEL_TABLE_SIZE;i++){ 1053 if (!fixed_channels[i].callback) continue; 1054 if (!fixed_channels[i].waiting_for_can_send_now) continue; 1055 int can_send; 1056 if (l2cap_fixed_channel_table_index_is_le(i)){ 1057 can_send = hci_can_send_acl_le_packet_now(); 1058 } else { 1059 can_send = hci_can_send_acl_classic_packet_now(); 1060 } 1061 if (!can_send) continue; 1062 fixed_channels[i].waiting_for_can_send_now = 0; 1063 l2cap_emit_can_send_now(fixed_channels[i].callback, l2cap_fixed_channel_table_channel_id_for_index(i)); 1064 } 1065 } 1066 1067 static void l2cap_hci_event_handler(uint8_t packet_type, uint16_t cid, uint8_t *packet, uint16_t size){ 1068 1069 bd_addr_t address; 1070 hci_con_handle_t handle; 1071 btstack_linked_list_iterator_t it; 1072 int hci_con_used; 1073 1074 switch(hci_event_packet_get_type(packet)){ 1075 1076 // handle connection complete events 1077 case HCI_EVENT_CONNECTION_COMPLETE: 1078 reverse_bd_addr(&packet[5], address); 1079 if (packet[2] == 0){ 1080 handle = little_endian_read_16(packet, 3); 1081 l2cap_handle_connection_success_for_addr(address, handle); 1082 } else { 1083 l2cap_handle_connection_failed_for_addr(address, packet[2]); 1084 } 1085 break; 1086 1087 // handle successful create connection cancel command 1088 case HCI_EVENT_COMMAND_COMPLETE: 1089 if (HCI_EVENT_IS_COMMAND_COMPLETE(packet, hci_create_connection_cancel)) { 1090 if (packet[5] == 0){ 1091 reverse_bd_addr(&packet[6], address); 1092 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 1093 l2cap_handle_connection_failed_for_addr(address, 0x16); 1094 } 1095 } 1096 l2cap_run(); // try sending signaling packets first 1097 break; 1098 1099 case HCI_EVENT_COMMAND_STATUS: 1100 l2cap_run(); // try sending signaling packets first 1101 break; 1102 1103 // handle disconnection complete events 1104 case HCI_EVENT_DISCONNECTION_COMPLETE: 1105 // send l2cap disconnect events for all channels on this handle and free them 1106 handle = little_endian_read_16(packet, 3); 1107 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1108 while (btstack_linked_list_iterator_has_next(&it)){ 1109 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1110 if (channel->con_handle != handle) continue; 1111 l2cap_emit_channel_closed(channel); 1112 l2cap_stop_rtx(channel); 1113 btstack_linked_list_iterator_remove(&it); 1114 btstack_memory_l2cap_channel_free(channel); 1115 } 1116 #ifdef ENABLE_BLE 1117 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1118 while (btstack_linked_list_iterator_has_next(&it)){ 1119 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1120 if (channel->con_handle != handle) continue; 1121 l2cap_emit_channel_closed(channel); 1122 btstack_linked_list_iterator_remove(&it); 1123 btstack_memory_l2cap_channel_free(channel); 1124 } 1125 #endif 1126 break; 1127 1128 // Notify channel packet handler if they can send now 1129 case HCI_EVENT_TRANSPORT_PACKET_SENT: 1130 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 1131 l2cap_run(); // try sending signaling packets first 1132 l2cap_notify_channel_can_send(); 1133 break; 1134 1135 // HCI Connection Timeouts 1136 case L2CAP_EVENT_TIMEOUT_CHECK: 1137 handle = little_endian_read_16(packet, 2); 1138 if (gap_get_connection_type(handle) != GAP_CONNECTION_ACL) break; 1139 if (hci_authentication_active_for_handle(handle)) break; 1140 hci_con_used = 0; 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 hci_con_used = 1; 1146 break; 1147 } 1148 if (hci_con_used) break; 1149 if (!hci_can_send_command_packet_now()) break; 1150 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 1151 break; 1152 1153 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 1154 handle = little_endian_read_16(packet, 3); 1155 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1156 while (btstack_linked_list_iterator_has_next(&it)){ 1157 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1158 if (channel->con_handle != handle) continue; 1159 l2cap_handle_remote_supported_features_received(channel); 1160 break; 1161 } 1162 break; 1163 1164 #ifdef ENABLE_BLE 1165 case HCI_EVENT_LE_META: 1166 switch (packet[2]){ 1167 int addr_type; 1168 l2cap_channel_t * channel; 1169 case HCI_SUBEVENT_LE_CONNECTION_COMPLETE: 1170 // Connection management 1171 reverse_bd_addr(&packet[8], address); 1172 addr_type = (bd_addr_type_t)packet[7]; 1173 log_info("L2CAP - LE Connection_complete (status=%u) type %u, %s", packet[3], addr_type, bd_addr_to_str(address)); 1174 // get l2cap_channel 1175 // also pass in status 1176 channel = l2cap_get_le_channel_for_address_and_addr_type(address, addr_type); 1177 if (!channel) break; 1178 l2cap_handle_le_connection_complete(channel, packet[3], little_endian_read_16(packet, 4)); 1179 break; 1180 default: 1181 break; 1182 } 1183 break; 1184 #endif 1185 1186 case GAP_EVENT_SECURITY_LEVEL: 1187 handle = little_endian_read_16(packet, 2); 1188 log_info("l2cap - security level update"); 1189 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1190 while (btstack_linked_list_iterator_has_next(&it)){ 1191 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1192 if (channel->con_handle != handle) continue; 1193 1194 log_info("l2cap - state %u", channel->state); 1195 1196 gap_security_level_t actual_level = (gap_security_level_t) packet[4]; 1197 gap_security_level_t required_level = channel->required_security_level; 1198 1199 switch (channel->state){ 1200 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 1201 if (actual_level >= required_level){ 1202 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 1203 l2cap_emit_connection_request(channel); 1204 } else { 1205 channel->reason = 0x0003; // security block 1206 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1207 } 1208 break; 1209 1210 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 1211 if (actual_level >= required_level){ 1212 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 1213 } else { 1214 // disconnnect, authentication not good enough 1215 hci_disconnect_security_block(handle); 1216 } 1217 break; 1218 1219 default: 1220 break; 1221 } 1222 } 1223 break; 1224 1225 default: 1226 break; 1227 } 1228 1229 l2cap_run(); 1230 } 1231 1232 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1233 channel->remote_sig_id = identifier; 1234 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1235 l2cap_run(); 1236 } 1237 1238 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 1239 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1240 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1241 signaling_responses[signaling_responses_pending].handle = handle; 1242 signaling_responses[signaling_responses_pending].code = code; 1243 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1244 signaling_responses[signaling_responses_pending].data = data; 1245 signaling_responses_pending++; 1246 l2cap_run(); 1247 } 1248 } 1249 1250 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1251 1252 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1253 l2cap_service_t *service = l2cap_get_service(psm); 1254 if (!service) { 1255 // 0x0002 PSM not supported 1256 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 1257 return; 1258 } 1259 1260 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1261 if (!hci_connection) { 1262 // 1263 log_error("no hci_connection for handle %u", handle); 1264 return; 1265 } 1266 1267 // alloc structure 1268 // log_info("l2cap_handle_connection_request register channel"); 1269 l2cap_channel_t * channel = l2cap_create_channel_entry(service->packet_handler, hci_connection->address, BD_ADDR_TYPE_CLASSIC, 1270 psm, service->mtu, service->required_security_level); 1271 if (!channel){ 1272 // 0x0004 No resources available 1273 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 1274 return; 1275 } 1276 1277 channel->con_handle = handle; 1278 channel->remote_cid = source_cid; 1279 channel->remote_sig_id = sig_id; 1280 1281 // limit local mtu to max acl packet length - l2cap header 1282 if (channel->local_mtu > l2cap_max_mtu()) { 1283 channel->local_mtu = l2cap_max_mtu(); 1284 } 1285 1286 // set initial state 1287 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1288 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 1289 1290 // add to connections list 1291 btstack_linked_list_add(&l2cap_channels, (btstack_linked_item_t *) channel); 1292 1293 // assert security requirements 1294 gap_request_security_level(handle, channel->required_security_level); 1295 } 1296 1297 void l2cap_accept_connection(uint16_t local_cid){ 1298 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1299 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1300 if (!channel) { 1301 log_error("l2cap_accept_connection called but local_cid 0x%x not found", local_cid); 1302 return; 1303 } 1304 1305 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1306 1307 // process 1308 l2cap_run(); 1309 } 1310 1311 void l2cap_decline_connection(uint16_t local_cid){ 1312 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x", local_cid); 1313 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1314 if (!channel) { 1315 log_error( "l2cap_decline_connection called but local_cid 0x%x not found", local_cid); 1316 return; 1317 } 1318 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1319 channel->reason = 0x04; // no resources available 1320 l2cap_run(); 1321 } 1322 1323 static void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1324 1325 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1326 1327 uint16_t flags = little_endian_read_16(command, 6); 1328 if (flags & 1) { 1329 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1330 } 1331 1332 // accept the other's configuration options 1333 uint16_t end_pos = 4 + little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1334 uint16_t pos = 8; 1335 while (pos < end_pos){ 1336 uint8_t option_hint = command[pos] >> 7; 1337 uint8_t option_type = command[pos] & 0x7f; 1338 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1339 pos++; 1340 uint8_t length = command[pos++]; 1341 // MTU { type(8): 1, len(8):2, MTU(16) } 1342 if (option_type == 1 && length == 2){ 1343 channel->remote_mtu = little_endian_read_16(command, pos); 1344 // log_info("l2cap cid 0x%02x, remote mtu %u", channel->local_cid, channel->remote_mtu); 1345 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1346 } 1347 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1348 if (option_type == 2 && length == 2){ 1349 channel->flush_timeout = little_endian_read_16(command, pos); 1350 } 1351 // check for unknown options 1352 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1353 log_info("l2cap cid %u, unknown options", channel->local_cid); 1354 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1355 } 1356 pos += length; 1357 } 1358 } 1359 1360 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1361 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1362 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1363 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1364 // addition check that fixes re-entrance issue causing l2cap event channel opened twice 1365 if (channel->state == L2CAP_STATE_OPEN) return 0; 1366 return 1; 1367 } 1368 1369 1370 static void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1371 1372 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1373 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1374 uint16_t result = 0; 1375 1376 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1377 1378 // handle DISCONNECT REQUESTS seperately 1379 if (code == DISCONNECTION_REQUEST){ 1380 switch (channel->state){ 1381 case L2CAP_STATE_CONFIG: 1382 case L2CAP_STATE_OPEN: 1383 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1384 case L2CAP_STATE_WAIT_DISCONNECT: 1385 l2cap_handle_disconnect_request(channel, identifier); 1386 break; 1387 1388 default: 1389 // ignore in other states 1390 break; 1391 } 1392 return; 1393 } 1394 1395 // @STATEMACHINE(l2cap) 1396 switch (channel->state) { 1397 1398 case L2CAP_STATE_WAIT_CONNECT_RSP: 1399 switch (code){ 1400 case CONNECTION_RESPONSE: 1401 l2cap_stop_rtx(channel); 1402 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1403 switch (result) { 1404 case 0: 1405 // successful connection 1406 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1407 channel->state = L2CAP_STATE_CONFIG; 1408 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1409 break; 1410 case 1: 1411 // connection pending. get some coffee, but start the ERTX 1412 l2cap_start_ertx(channel); 1413 break; 1414 default: 1415 // channel closed 1416 channel->state = L2CAP_STATE_CLOSED; 1417 // map l2cap connection response result to BTstack status enumeration 1418 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1419 1420 // drop link key if security block 1421 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1422 gap_drop_link_key_for_bd_addr(channel->address); 1423 } 1424 1425 // discard channel 1426 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1427 btstack_memory_l2cap_channel_free(channel); 1428 break; 1429 } 1430 break; 1431 1432 default: 1433 //@TODO: implement other signaling packets 1434 break; 1435 } 1436 break; 1437 1438 case L2CAP_STATE_CONFIG: 1439 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1440 switch (code) { 1441 case CONFIGURE_REQUEST: 1442 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1443 l2cap_signaling_handle_configure_request(channel, command); 1444 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1445 // only done if continuation not set 1446 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1447 } 1448 break; 1449 case CONFIGURE_RESPONSE: 1450 l2cap_stop_rtx(channel); 1451 switch (result){ 1452 case 0: // success 1453 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1454 break; 1455 case 4: // pending 1456 l2cap_start_ertx(channel); 1457 break; 1458 default: 1459 // retry on negative result 1460 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1461 break; 1462 } 1463 break; 1464 default: 1465 break; 1466 } 1467 if (l2cap_channel_ready_for_open(channel)){ 1468 // for open: 1469 channel->state = L2CAP_STATE_OPEN; 1470 l2cap_emit_channel_opened(channel, 0); 1471 } 1472 break; 1473 1474 case L2CAP_STATE_WAIT_DISCONNECT: 1475 switch (code) { 1476 case DISCONNECTION_RESPONSE: 1477 l2cap_finialize_channel_close(channel); 1478 break; 1479 default: 1480 //@TODO: implement other signaling packets 1481 break; 1482 } 1483 break; 1484 1485 case L2CAP_STATE_CLOSED: 1486 // @TODO handle incoming requests 1487 break; 1488 1489 case L2CAP_STATE_OPEN: 1490 //@TODO: implement other signaling packets, e.g. re-configure 1491 break; 1492 default: 1493 break; 1494 } 1495 // log_info("new state %u", channel->state); 1496 } 1497 1498 1499 static void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1500 1501 // get code, signalind identifier and command len 1502 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1503 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1504 1505 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1506 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1507 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1508 return; 1509 } 1510 1511 // general commands without an assigned channel 1512 switch(code) { 1513 1514 case CONNECTION_REQUEST: { 1515 uint16_t psm = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1516 uint16_t source_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1517 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1518 return; 1519 } 1520 1521 case ECHO_REQUEST: 1522 l2cap_register_signaling_response(handle, code, sig_id, 0); 1523 return; 1524 1525 case INFORMATION_REQUEST: { 1526 uint16_t infoType = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1527 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1528 return; 1529 } 1530 1531 default: 1532 break; 1533 } 1534 1535 1536 // Get potential destination CID 1537 uint16_t dest_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1538 1539 // Find channel for this sig_id and connection handle 1540 btstack_linked_list_iterator_t it; 1541 btstack_linked_list_iterator_init(&it, &l2cap_channels); 1542 while (btstack_linked_list_iterator_has_next(&it)){ 1543 l2cap_channel_t * channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1544 if (channel->con_handle != handle) continue; 1545 if (code & 1) { 1546 // match odd commands (responses) by previous signaling identifier 1547 if (channel->local_sig_id == sig_id) { 1548 l2cap_signaling_handler_channel(channel, command); 1549 break; 1550 } 1551 } else { 1552 // match even commands (requests) by local channel id 1553 if (channel->local_cid == dest_cid) { 1554 l2cap_signaling_handler_channel(channel, command); 1555 break; 1556 } 1557 } 1558 } 1559 } 1560 1561 #ifdef ENABLE_BLE 1562 // @returns valid 1563 static int l2cap_le_signaling_handler_dispatch(hci_con_handle_t handle, uint8_t * command, uint8_t sig_id){ 1564 hci_connection_t * connection; 1565 uint16_t result; 1566 uint8_t event[10]; 1567 uint16_t le_psm; 1568 uint16_t local_cid; 1569 uint16_t new_credits; 1570 uint16_t credits_before; 1571 l2cap_service_t * service; 1572 l2cap_channel_t * channel; 1573 btstack_linked_list_iterator_t it; 1574 1575 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1576 log_info("l2cap_le_signaling_handler_dispatch: command 0x%02x, sig id %u", code, sig_id); 1577 1578 switch (code){ 1579 1580 case CONNECTION_PARAMETER_UPDATE_RESPONSE: 1581 result = little_endian_read_16(command, 4); 1582 l2cap_emit_connection_parameter_update_response(handle, result); 1583 break; 1584 1585 case CONNECTION_PARAMETER_UPDATE_REQUEST: 1586 connection = hci_connection_for_handle(handle); 1587 if (connection){ 1588 if (connection->role != HCI_ROLE_MASTER){ 1589 // reject command without notifying upper layer when not in master role 1590 return 0; 1591 } 1592 int update_parameter = 1; 1593 le_connection_parameter_range_t existing_range; 1594 gap_get_connection_parameter_range(&existing_range); 1595 uint16_t le_conn_interval_min = little_endian_read_16(command,8); 1596 uint16_t le_conn_interval_max = little_endian_read_16(command,10); 1597 uint16_t le_conn_latency = little_endian_read_16(command,12); 1598 uint16_t le_supervision_timeout = little_endian_read_16(command,14); 1599 1600 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 1601 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 1602 1603 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 1604 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 1605 1606 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 1607 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 1608 1609 if (update_parameter){ 1610 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 1611 connection->le_conn_interval_min = le_conn_interval_min; 1612 connection->le_conn_interval_max = le_conn_interval_max; 1613 connection->le_conn_latency = le_conn_latency; 1614 connection->le_supervision_timeout = le_supervision_timeout; 1615 } else { 1616 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 1617 } 1618 connection->le_con_param_update_identifier = sig_id; 1619 } 1620 1621 if (!l2cap_event_packet_handler) break; 1622 1623 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 1624 event[1] = 8; 1625 memcpy(&event[2], &command[4], 8); 1626 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1627 (*l2cap_event_packet_handler)( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1628 break; 1629 1630 case COMMAND_REJECT: 1631 // Find channel for this sig_id and connection handle 1632 channel = NULL; 1633 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1634 while (btstack_linked_list_iterator_has_next(&it)){ 1635 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1636 if (a_channel->con_handle != handle) continue; 1637 if (a_channel->local_sig_id != sig_id) continue; 1638 channel = a_channel; 1639 break; 1640 } 1641 if (!channel) break; 1642 1643 // if received while waiting for le connection response, assume legacy device 1644 if (channel->state == L2CAP_STATE_WAIT_LE_CONNECTION_RESPONSE){ 1645 channel->state = L2CAP_STATE_CLOSED; 1646 // no official value for this, use: Connection refused – LE_PSM not supported - 0x0002 1647 l2cap_emit_channel_opened(channel, 0x0002); 1648 1649 // discard channel 1650 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1651 btstack_memory_l2cap_channel_free(channel); 1652 break; 1653 } 1654 break; 1655 1656 case LE_CREDIT_BASED_CONNECTION_REQUEST: 1657 1658 // get hci connection, bail if not found (must not happen) 1659 connection = hci_connection_for_handle(handle); 1660 if (!connection) return 0; 1661 1662 // check if service registered 1663 le_psm = little_endian_read_16(command, 4); 1664 service = l2cap_le_get_service(le_psm); 1665 1666 if (service){ 1667 1668 uint16_t source_cid = little_endian_read_16(command, 6); 1669 if (source_cid < 0x40){ 1670 // 0x0009 Connection refused - Invalid Source CID 1671 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0009); 1672 return 1; 1673 } 1674 1675 // go through list of channels for this ACL connection and check if we get a match 1676 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1677 while (btstack_linked_list_iterator_has_next(&it)){ 1678 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1679 if (a_channel->con_handle != handle) continue; 1680 if (a_channel->remote_cid != source_cid) continue; 1681 // 0x000a Connection refused - Source CID already allocated 1682 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x000a); 1683 return 1; 1684 } 1685 1686 // TODO: deal with authentication requirements, errors 0x005 - 000x8 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 1707 // add to connections list 1708 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1709 1710 // post connection request event 1711 l2cap_emit_connection_request(channel); 1712 1713 } else { 1714 // Connection refused – LE_PSM not supported 1715 l2cap_register_signaling_response(handle, LE_CREDIT_BASED_CONNECTION_REQUEST, sig_id, 0x0002); 1716 } 1717 break; 1718 1719 case LE_CREDIT_BASED_CONNECTION_RESPONSE: 1720 // Find channel for this sig_id and connection handle 1721 channel = NULL; 1722 btstack_linked_list_iterator_init(&it, &l2cap_le_channels); 1723 while (btstack_linked_list_iterator_has_next(&it)){ 1724 l2cap_channel_t * a_channel = (l2cap_channel_t *) btstack_linked_list_iterator_next(&it); 1725 if (a_channel->con_handle != handle) continue; 1726 if (a_channel->local_sig_id != sig_id) continue; 1727 channel = a_channel; 1728 break; 1729 } 1730 if (!channel) break; 1731 1732 // cid + 0 1733 result = little_endian_read_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+8); 1734 if (result){ 1735 channel->state = L2CAP_STATE_CLOSED; 1736 // map l2cap connection response result to BTstack status enumeration 1737 l2cap_emit_channel_opened(channel, result); 1738 1739 // discard channel 1740 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1741 btstack_memory_l2cap_channel_free(channel); 1742 break; 1743 } 1744 1745 // success 1746 channel->remote_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1747 channel->remote_mtu = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1748 channel->remote_mps = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 4); 1749 channel->credits_outgoing = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 6); 1750 channel->state = L2CAP_STATE_OPEN; 1751 l2cap_emit_channel_opened(channel, result); 1752 break; 1753 1754 case LE_FLOW_CONTROL_CREDIT: 1755 // find channel 1756 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1757 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1758 if (!channel) { 1759 log_error("l2cap: no channel for cid 0x%02x", local_cid); 1760 break; 1761 } 1762 new_credits = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 2); 1763 credits_before = channel->credits_outgoing; 1764 channel->credits_outgoing += new_credits; 1765 // check for credit overrun 1766 if (credits_before > channel->credits_outgoing){ 1767 log_error("l2cap: new credits caused overrrun for cid 0x%02x, disconnecting", local_cid); 1768 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1769 break; 1770 } 1771 log_info("l2cap: %u credits for 0x%02x, now %u", new_credits, local_cid, channel->credits_outgoing); 1772 break; 1773 1774 case DISCONNECTION_REQUEST: 1775 // find channel 1776 local_cid = little_endian_read_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET + 0); 1777 channel = l2cap_le_get_channel_for_local_cid(local_cid); 1778 if (!channel) break; 1779 channel->remote_sig_id = sig_id; 1780 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1781 break; 1782 1783 case DISCONNECTION_RESPONSE: 1784 break; 1785 1786 default: 1787 // command unknown -> reject command 1788 return 0; 1789 } 1790 return 1; 1791 } 1792 #endif 1793 1794 static void l2cap_acl_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size ){ 1795 1796 // Get Channel ID 1797 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1798 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1799 1800 switch (channel_id) { 1801 1802 case L2CAP_CID_SIGNALING: { 1803 uint16_t command_offset = 8; 1804 while (command_offset < size) { 1805 // handle signaling commands 1806 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1807 1808 // increment command_offset 1809 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + little_endian_read_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1810 } 1811 break; 1812 } 1813 1814 #ifdef ENABLE_BLE 1815 case L2CAP_CID_SIGNALING_LE: { 1816 uint16_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1817 int valid = l2cap_le_signaling_handler_dispatch(handle, &packet[COMPLETE_L2CAP_HEADER], sig_id); 1818 if (!valid){ 1819 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1820 } 1821 break; 1822 } 1823 #endif 1824 1825 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1826 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback) { 1827 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_ATTRIBUTE_PROTOCOL].callback)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1828 } 1829 break; 1830 1831 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1832 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback) { 1833 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_SECURITY_MANAGER_PROTOCOL].callback)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1834 } 1835 break; 1836 1837 case L2CAP_CID_CONNECTIONLESS_CHANNEL: 1838 if (fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback) { 1839 (*fixed_channels[L2CAP_FIXED_CHANNEL_TABLE_INDEX_CONNECTIONLESS_CHANNEL].callback)(UCD_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1840 } 1841 break; 1842 1843 default: { 1844 // Find channel for this channel_id and connection handle 1845 l2cap_channel_t * l2cap_channel; 1846 l2cap_channel = l2cap_get_channel_for_local_cid(channel_id); 1847 if (l2cap_channel) { 1848 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1849 } 1850 #ifdef ENABLE_BLE 1851 l2cap_channel = l2cap_le_get_channel_for_local_cid(channel_id); 1852 if (l2cap_channel) { 1853 // credit counting 1854 if (l2cap_channel->credits_incoming == 0){ 1855 log_error("LE Data Channel packet received but no incoming credits"); 1856 l2cap_channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1857 break; 1858 } 1859 l2cap_channel->credits_incoming--; 1860 1861 // automatic credits 1862 if (l2cap_channel->credits_incoming < L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_WATERMARK && l2cap_channel->automatic_credits){ 1863 l2cap_channel->new_credits_incoming = L2CAP_LE_DATA_CHANNELS_AUTOMATIC_CREDITS_INCREMENT; 1864 } 1865 1866 // first fragment 1867 uint16_t pos = 0; 1868 if (!l2cap_channel->receive_sdu_len){ 1869 l2cap_channel->receive_sdu_len = little_endian_read_16(packet, COMPLETE_L2CAP_HEADER); 1870 l2cap_channel->receive_sdu_pos = 0; 1871 pos += 2; 1872 size -= 2; 1873 } 1874 memcpy(&l2cap_channel->receive_sdu_buffer[l2cap_channel->receive_sdu_pos], &packet[COMPLETE_L2CAP_HEADER+pos], size-COMPLETE_L2CAP_HEADER); 1875 l2cap_channel->receive_sdu_pos += size - COMPLETE_L2CAP_HEADER; 1876 // done? 1877 log_info("le packet pos %u, len %u", l2cap_channel->receive_sdu_pos, l2cap_channel->receive_sdu_len); 1878 if (l2cap_channel->receive_sdu_pos >= l2cap_channel->receive_sdu_len){ 1879 l2cap_dispatch_to_channel(l2cap_channel, L2CAP_DATA_PACKET, l2cap_channel->receive_sdu_buffer, l2cap_channel->receive_sdu_len); 1880 l2cap_channel->receive_sdu_len = 0; 1881 } 1882 } else { 1883 log_error("LE Data Channel packet received but no channel found for cid 0x%02x", channel_id); 1884 } 1885 #endif 1886 break; 1887 } 1888 } 1889 1890 l2cap_run(); 1891 } 1892 1893 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1894 void l2cap_finialize_channel_close(l2cap_channel_t * channel){ 1895 channel->state = L2CAP_STATE_CLOSED; 1896 l2cap_emit_channel_closed(channel); 1897 // discard channel 1898 l2cap_stop_rtx(channel); 1899 btstack_linked_list_remove(&l2cap_channels, (btstack_linked_item_t *) channel); 1900 btstack_memory_l2cap_channel_free(channel); 1901 } 1902 1903 #ifdef ENABLE_BLE 1904 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1905 void l2cap_le_finialize_channel_close(l2cap_channel_t * channel){ 1906 channel->state = L2CAP_STATE_CLOSED; 1907 l2cap_emit_channel_closed(channel); 1908 // discard channel 1909 l2cap_stop_rtx(channel); 1910 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 1911 btstack_memory_l2cap_channel_free(channel); 1912 } 1913 #endif 1914 1915 static l2cap_service_t * l2cap_get_service_internal(btstack_linked_list_t * services, uint16_t psm){ 1916 btstack_linked_list_iterator_t it; 1917 btstack_linked_list_iterator_init(&it, services); 1918 while (btstack_linked_list_iterator_has_next(&it)){ 1919 l2cap_service_t * service = (l2cap_service_t *) btstack_linked_list_iterator_next(&it); 1920 if ( service->psm == psm){ 1921 return service; 1922 }; 1923 } 1924 return NULL; 1925 } 1926 1927 static inline l2cap_service_t * l2cap_get_service(uint16_t psm){ 1928 return l2cap_get_service_internal(&l2cap_services, psm); 1929 } 1930 1931 1932 uint8_t l2cap_register_service(btstack_packet_handler_t service_packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 1933 1934 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1935 1936 // check for alread registered psm 1937 l2cap_service_t *service = l2cap_get_service(psm); 1938 if (service) { 1939 log_error("l2cap_register_service: PSM %u already registered", psm); 1940 return L2CAP_SERVICE_ALREADY_REGISTERED; 1941 } 1942 1943 // alloc structure 1944 service = btstack_memory_l2cap_service_get(); 1945 if (!service) { 1946 log_error("l2cap_register_service: no memory for l2cap_service_t"); 1947 return BTSTACK_MEMORY_ALLOC_FAILED; 1948 } 1949 1950 // fill in 1951 service->psm = psm; 1952 service->mtu = mtu; 1953 service->packet_handler = service_packet_handler; 1954 service->required_security_level = security_level; 1955 1956 // add to services list 1957 btstack_linked_list_add(&l2cap_services, (btstack_linked_item_t *) service); 1958 1959 // enable page scan 1960 gap_connectable_control(1); 1961 1962 return 0; 1963 } 1964 1965 uint8_t l2cap_unregister_service(uint16_t psm){ 1966 1967 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1968 1969 l2cap_service_t *service = l2cap_get_service(psm); 1970 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 1971 btstack_linked_list_remove(&l2cap_services, (btstack_linked_item_t *) service); 1972 btstack_memory_l2cap_service_free(service); 1973 1974 // disable page scan when no services registered 1975 if (btstack_linked_list_empty(&l2cap_services)) { 1976 gap_connectable_control(0); 1977 } 1978 return 0; 1979 } 1980 1981 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1982 void l2cap_register_fixed_channel(btstack_packet_handler_t the_packet_handler, uint16_t channel_id) { 1983 int index = l2cap_fixed_channel_table_index_for_channel_id(channel_id); 1984 if (index < 0) return; 1985 fixed_channels[index].callback = the_packet_handler; 1986 } 1987 1988 #ifdef ENABLE_BLE 1989 1990 static inline l2cap_service_t * l2cap_le_get_service(uint16_t le_psm){ 1991 return l2cap_get_service_internal(&l2cap_le_services, le_psm); 1992 } 1993 1994 uint8_t l2cap_le_register_service(btstack_packet_handler_t packet_handler, uint16_t psm, gap_security_level_t security_level){ 1995 1996 log_info("L2CAP_LE_REGISTER_SERVICE psm 0x%x", psm); 1997 1998 // check for alread registered psm 1999 l2cap_service_t *service = l2cap_le_get_service(psm); 2000 if (service) { 2001 return L2CAP_SERVICE_ALREADY_REGISTERED; 2002 } 2003 2004 // alloc structure 2005 service = btstack_memory_l2cap_service_get(); 2006 if (!service) { 2007 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 2008 return BTSTACK_MEMORY_ALLOC_FAILED; 2009 } 2010 2011 // fill in 2012 service->psm = psm; 2013 service->mtu = 0; 2014 service->packet_handler = packet_handler; 2015 service->required_security_level = security_level; 2016 2017 // add to services list 2018 btstack_linked_list_add(&l2cap_le_services, (btstack_linked_item_t *) service); 2019 2020 // done 2021 return 0; 2022 } 2023 2024 uint8_t l2cap_le_unregister_service(uint16_t psm) { 2025 log_info("L2CAP_LE_UNREGISTER_SERVICE psm 0x%x", psm); 2026 l2cap_service_t *service = l2cap_le_get_service(psm); 2027 if (!service) return L2CAP_SERVICE_DOES_NOT_EXIST; 2028 2029 btstack_linked_list_remove(&l2cap_le_services, (btstack_linked_item_t *) service); 2030 btstack_memory_l2cap_service_free(service); 2031 return 0; 2032 } 2033 2034 uint8_t l2cap_le_accept_connection(uint16_t local_cid, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits){ 2035 // get channel 2036 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2037 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2038 2039 // validate state 2040 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2041 return ERROR_CODE_COMMAND_DISALLOWED; 2042 } 2043 2044 // set state accept connection 2045 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_ACCEPT; 2046 channel->receive_sdu_buffer = receive_sdu_buffer; 2047 channel->local_mtu = mtu; 2048 channel->new_credits_incoming = initial_credits; 2049 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2050 2051 // test 2052 // channel->new_credits_incoming = 1; 2053 2054 // go 2055 l2cap_run(); 2056 return 0; 2057 } 2058 2059 /** 2060 * @brief Deny incoming LE Data Channel connection due to resource constraints 2061 * @param local_cid L2CAP LE Data Channel Identifier 2062 */ 2063 2064 uint8_t l2cap_le_decline_connection(uint16_t local_cid){ 2065 // get channel 2066 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2067 if (!channel) return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2068 2069 // validate state 2070 if (channel->state != L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT){ 2071 return ERROR_CODE_COMMAND_DISALLOWED; 2072 } 2073 2074 // set state decline connection 2075 channel->state = L2CAP_STATE_WILL_SEND_LE_CONNECTION_RESPONSE_DECLINE; 2076 channel->reason = 0x04; // no resources available 2077 l2cap_run(); 2078 return 0; 2079 } 2080 2081 uint8_t l2cap_le_create_channel(btstack_packet_handler_t packet_handler, bd_addr_t address, bd_addr_type_t address_type, 2082 uint16_t psm, uint8_t * receive_sdu_buffer, uint16_t mtu, uint16_t initial_credits, gap_security_level_t security_level, 2083 uint16_t * out_local_cid) { 2084 2085 log_info("L2CAP_LE_CREATE_CHANNEL addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 2086 2087 l2cap_channel_t * channel = l2cap_create_channel_entry(packet_handler, address, address_type, psm, mtu, security_level); 2088 if (!channel) { 2089 return BTSTACK_MEMORY_ALLOC_FAILED; 2090 } 2091 log_info("l2cap_le_create_channel %p", channel); 2092 2093 // store local_cid 2094 if (out_local_cid){ 2095 *out_local_cid = channel->local_cid; 2096 } 2097 2098 // provdide buffer 2099 channel->receive_sdu_buffer = receive_sdu_buffer; 2100 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 2101 channel->new_credits_incoming = initial_credits; 2102 channel->automatic_credits = initial_credits == L2CAP_LE_AUTOMATIC_CREDITS; 2103 2104 // test 2105 // channel->new_credits_incoming = 1; 2106 2107 // add to connections list 2108 btstack_linked_list_add(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2109 2110 // check if hci connection is already usable 2111 hci_connection_t * conn = hci_connection_for_bd_addr_and_type(address, address_type); 2112 2113 if (conn){ 2114 log_info("l2cap_le_create_channel, hci connection already exists"); 2115 l2cap_handle_le_connection_complete(channel, 0, conn->con_handle); 2116 l2cap_run(); 2117 } else { 2118 2119 // 2120 // TODO: start timer 2121 // .. 2122 2123 // start connection 2124 uint8_t res = gap_auto_connection_start(address_type, address); 2125 if (res){ 2126 // discard channel object 2127 log_info("gap_auto_connection_start failed! 0x%02x", res); 2128 btstack_linked_list_remove(&l2cap_le_channels, (btstack_linked_item_t *) channel); 2129 btstack_memory_l2cap_channel_free(channel); 2130 return res; 2131 } 2132 } 2133 return 0; 2134 } 2135 2136 /** 2137 * @brief Provide credtis for LE Data Channel 2138 * @param local_cid L2CAP LE Data Channel Identifier 2139 * @param credits Number additional credits for peer 2140 */ 2141 uint8_t l2cap_le_provide_credits(uint16_t local_cid, uint16_t credits){ 2142 2143 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2144 if (!channel) { 2145 log_error("l2cap_le_provide_credits no channel for cid 0x%02x", local_cid); 2146 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2147 } 2148 2149 // check state 2150 if (channel->state != L2CAP_STATE_OPEN){ 2151 log_error("l2cap_le_provide_credits but channel 0x%02x not open yet", local_cid); 2152 } 2153 2154 // assert incoming credits + credits <= 0xffff 2155 uint32_t total_credits = channel->credits_incoming; 2156 total_credits += channel->new_credits_incoming; 2157 total_credits += credits; 2158 if (total_credits > 0xffff){ 2159 log_error("l2cap_le_provide_credits overrun: current %u, scheduled %u, additional %u", channel->credits_incoming, 2160 channel->new_credits_incoming, credits); 2161 } 2162 2163 // set credits_granted 2164 channel->new_credits_incoming += credits; 2165 2166 // go 2167 l2cap_run(); 2168 return 0; 2169 } 2170 2171 /** 2172 * @brief Check if outgoing buffer is available and that there's space on the Bluetooth module 2173 * @param local_cid L2CAP LE Data Channel Identifier 2174 */ 2175 int l2cap_le_can_send_now(uint16_t local_cid){ 2176 // check if data can be sent via le at all 2177 return 0; 2178 } 2179 2180 /** 2181 * @brief Request emission of L2CAP_EVENT_CAN_SEND_NOW as soon as possible 2182 * @note L2CAP_EVENT_CAN_SEND_NOW might be emitted during call to this function 2183 * so packet handler should be ready to handle it 2184 * @param local_cid L2CAP LE Data Channel Identifier 2185 */ 2186 uint8_t l2cap_le_request_can_send_now_event(uint16_t local_cid){ 2187 // same as for non-le 2188 return 0; 2189 } 2190 2191 /** 2192 * @brief Send data via LE Data Channel 2193 * @note Since data larger then the maximum PDU needs to be segmented into multiple PDUs, data needs to stay valid until ... event 2194 * @param local_cid L2CAP LE Data Channel Identifier 2195 * @param data data to send 2196 * @param size data size 2197 */ 2198 uint8_t l2cap_le_send_data(uint16_t local_cid, uint8_t * data, uint16_t len){ 2199 2200 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2201 if (!channel) { 2202 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2203 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2204 } 2205 2206 if (len > channel->remote_mtu){ 2207 log_error("l2cap_send cid 0x%02x, data length exceeds remote MTU.", local_cid); 2208 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 2209 } 2210 2211 if (channel->send_sdu_buffer){ 2212 log_info("l2cap_send cid 0x%02x, cannot send", local_cid); 2213 return BTSTACK_ACL_BUFFERS_FULL; 2214 } 2215 2216 channel->send_sdu_buffer = data; 2217 channel->send_sdu_len = len; 2218 channel->send_sdu_pos = 0; 2219 2220 l2cap_run(); 2221 return 0; 2222 } 2223 2224 /** 2225 * @brief Disconnect from LE Data Channel 2226 * @param local_cid L2CAP LE Data Channel Identifier 2227 */ 2228 uint8_t l2cap_le_disconnect(uint16_t local_cid) 2229 { 2230 l2cap_channel_t * channel = l2cap_le_get_channel_for_local_cid(local_cid); 2231 if (!channel) { 2232 log_error("l2cap_send no channel for cid 0x%02x", local_cid); 2233 return L2CAP_LOCAL_CID_DOES_NOT_EXIST; 2234 } 2235 2236 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 2237 l2cap_run(); 2238 return 0; 2239 } 2240 2241 #endif 2242