1 /* 2 * Copyright (C) 2009 by Matthias Ringwald 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 * 17 * THIS SOFTWARE IS PROVIDED BY MATTHIAS RINGWALD AND CONTRIBUTORS 18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 20 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 21 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 23 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 24 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 25 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 26 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 27 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 */ 31 32 /* 33 * l2cap.c 34 * 35 * Logical Link Control and Adaption Protocl (L2CAP) 36 * 37 * Created by Matthias Ringwald on 5/16/09. 38 */ 39 40 #include "l2cap.h" 41 #include "hci.h" 42 43 #include <stdarg.h> 44 #include <string.h> 45 46 #include <stdio.h> 47 48 // size of HCI ACL + L2CAP Header for regular data packets 49 #define COMPLETE_L2CAP_HEADER 8 50 51 static void null_event_handler(uint8_t *packet, uint16_t size); 52 static void null_data_handler(uint16_t source_cid, uint8_t *packet, uint16_t size); 53 54 static uint8_t * sig_buffer = NULL; 55 static linked_list_t l2cap_channels = NULL; 56 static linked_list_t l2cap_services = NULL; 57 static uint8_t * acl_buffer = NULL; 58 static void (*event_packet_handler) (uint8_t *packet, uint16_t size) = null_event_handler; 59 static void (*data_packet_handler) (uint16_t source_cid, uint8_t *packet, uint16_t size) = null_data_handler; 60 static connection_t * capture_connection = NULL; 61 62 static uint8_t config_options[] = { 1, 2, 150, 0}; // mtu = 48 63 64 void l2cap_init(){ 65 sig_buffer = malloc( 48 ); 66 acl_buffer = malloc( 255 + 8 ); 67 68 // 69 // register callbacks with HCI 70 // 71 hci_register_event_packet_handler(&l2cap_event_handler); 72 hci_register_acl_packet_handler(&l2cap_acl_handler); 73 } 74 75 76 /** Register L2CAP packet handlers */ 77 static void null_event_handler(uint8_t *packet, uint16_t size){ 78 } 79 static void null_data_handler(uint16_t source_cid, uint8_t *packet, uint16_t size){ 80 } 81 void l2cap_register_event_packet_handler(void (*handler)(uint8_t *packet, uint16_t size)){ 82 event_packet_handler = handler; 83 } 84 void l2cap_register_data_packet_handler (void (*handler)(uint16_t source_cid, uint8_t *packet, uint16_t size)){ 85 data_packet_handler = handler; 86 } 87 88 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 89 va_list argptr; 90 va_start(argptr, identifier); 91 uint16_t len = l2cap_create_signaling_internal(sig_buffer, handle, cmd, identifier, argptr); 92 va_end(argptr); 93 return hci_send_acl_packet(sig_buffer, len); 94 } 95 96 l2cap_channel_t * l2cap_get_channel_for_source_cid(uint16_t source_cid){ 97 linked_item_t *it; 98 l2cap_channel_t * channel; 99 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 100 channel = (l2cap_channel_t *) it; 101 if ( channel->source_cid == source_cid) { 102 return channel; 103 } 104 } 105 return NULL; 106 } 107 108 // open outgoing L2CAP channel 109 void l2cap_create_channel_internal(connection_t * connection, bd_addr_t address, uint16_t psm){ 110 111 // alloc structure 112 l2cap_channel_t * chan = malloc(sizeof(l2cap_channel_t)); 113 // TODO: emit error event 114 if (!chan) return; 115 116 // fill in 117 BD_ADDR_COPY(chan->address, address); 118 chan->psm = psm; 119 chan->handle = 0; 120 chan->connection = connection; 121 122 // set initial state 123 chan->state = L2CAP_STATE_CLOSED; 124 chan->sig_id = L2CAP_SIG_ID_INVALID; 125 126 // add to connections list 127 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 128 129 // send connection request 130 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 131 hci_send_cmd(&hci_create_connection, address, 0x18, 0, 0, 0, 0); 132 } 133 134 void l2cap_disconnect_internal(uint16_t source_cid, uint8_t reason){ 135 // find channel for source_cid 136 l2cap_channel_t * channel = l2cap_get_channel_for_source_cid(source_cid); 137 if (channel) { 138 channel->sig_id = l2cap_next_sig_id(); 139 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->dest_cid, channel->source_cid); 140 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 141 } 142 } 143 144 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 145 linked_item_t *it; 146 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 147 l2cap_channel_t * channel = (l2cap_channel_t *) it; 148 if ( ! BD_ADDR_CMP( channel->address, address) ){ 149 if (channel->state == L2CAP_STATE_CLOSED) { 150 // failure, forward error code 151 l2cap_emit_channel_opened(channel, status); 152 // discard channel 153 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 154 free (channel); 155 } 156 } 157 } 158 } 159 160 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 161 linked_item_t *it; 162 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 163 l2cap_channel_t * channel = (l2cap_channel_t *) it; 164 if ( ! BD_ADDR_CMP( channel->address, address) ){ 165 if (channel->state == L2CAP_STATE_CLOSED) { 166 // success, start l2cap handshake 167 channel->handle = handle; 168 channel->sig_id = l2cap_next_sig_id(); 169 channel->source_cid = l2cap_next_source_cid(); 170 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 171 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->sig_id, channel->psm, channel->source_cid); 172 } 173 } 174 } 175 } 176 177 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 178 179 bd_addr_t address; 180 hci_con_handle_t handle; 181 182 switch(packet[0]){ 183 184 // handle connection complete events 185 case HCI_EVENT_CONNECTION_COMPLETE: 186 bt_flip_addr(address, &packet[5]); 187 if (packet[2] == 0){ 188 handle = READ_BT_16(packet, 3); 189 l2cap_handle_connection_success_for_addr(address, handle); 190 } else { 191 l2cap_handle_connection_failed_for_addr(address, packet[2]); 192 } 193 break; 194 195 // handle successful create connection cancel command 196 case HCI_EVENT_COMMAND_COMPLETE: 197 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 198 if (packet[5] == 0){ 199 bt_flip_addr(address, &packet[6]); 200 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 201 l2cap_handle_connection_failed_for_addr(address, 0x16); 202 } 203 } 204 break; 205 206 // handle disconnection complete events 207 case HCI_EVENT_DISCONNECTION_COMPLETE: 208 // send l2cap disconnect events for all channels on this handle 209 handle = READ_BT_16(packet, 3); 210 linked_item_t *it; 211 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 212 l2cap_channel_t * channel = (l2cap_channel_t *) it; 213 if ( channel->handle == handle ){ 214 l2cap_finialize_channel_close(channel); 215 } 216 } 217 break; 218 219 // HCI Connection Timeouts 220 case L2CAP_EVENT_TIMEOUT_CHECK: 221 if (!capture_connection){ 222 hci_con_handle_t handle = READ_BT_16(packet, 2); 223 linked_item_t *it; 224 l2cap_channel_t * channel; 225 int used = 0; 226 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 227 channel = (l2cap_channel_t *) it; 228 if (channel->handle == handle) { 229 used = 1; 230 } 231 } 232 if (!used) { 233 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 234 } 235 } 236 break; 237 238 default: 239 break; 240 } 241 242 // pass on 243 (*event_packet_handler)(packet, size); 244 } 245 246 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 247 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, identifier, channel->dest_cid, channel->source_cid); 248 l2cap_finialize_channel_close(channel); 249 } 250 251 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t dest_cid){ 252 253 // printf("l2cap_handle_connection_request for handle %u, psm %u cid %u\n", handle, psm, dest_cid); 254 l2cap_service_t *service = l2cap_get_service(psm); 255 if (!service) { 256 // 0x0002 PSM not supported 257 // printf("l2cap_handle_connection_request no PSM for psm %u/n", psm); 258 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, 0x0002, 0); 259 return; 260 } 261 262 hci_connection_t * hci_connection = connection_for_handle( handle ); 263 if (!hci_connection) { 264 fprintf(stderr, "no hci_connection for handle %u\n", handle); 265 // TODO: emit error 266 return; 267 } 268 // alloc structure 269 // printf("l2cap_handle_connection_request register channel\n"); 270 l2cap_channel_t * channel = malloc(sizeof(l2cap_channel_t)); 271 // TODO: emit error event 272 if (!channel) return; 273 274 // fill in 275 BD_ADDR_COPY(channel->address, hci_connection->address); 276 channel->psm = psm; 277 channel->handle = handle; 278 channel->connection = service->connection; 279 channel->source_cid = l2cap_next_source_cid(); 280 channel->dest_cid = dest_cid; 281 282 // set initial state 283 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 284 285 // temp. store req sig id 286 channel->sig_id = sig_id; 287 288 // add to connections list 289 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 290 291 // emit incoming connection request 292 l2cap_emit_connection_request(channel); 293 } 294 295 void l2cap_accept_connection_internal(uint16_t source_cid){ 296 l2cap_channel_t * channel = l2cap_get_channel_for_source_cid(source_cid); 297 if (!channel) { 298 fprintf(stderr, "l2cap_accept_connection_internal called but source_cid 0x%x not found", source_cid); 299 return; 300 } 301 302 // accept connection 303 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, channel->dest_cid, channel->source_cid, 0, 0); 304 305 // set real sig and state and start config 306 channel->sig_id = l2cap_next_sig_id(); 307 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 308 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->dest_cid, 0, 4, &config_options); 309 } 310 311 void l2cap_decline_connection_internal(uint16_t source_cid, uint8_t reason){ 312 l2cap_channel_t * channel = l2cap_get_channel_for_source_cid( source_cid); 313 if (!channel) { 314 fprintf(stderr, "l2cap_decline_connection_internal called but source_cid 0x%x not found", source_cid,reason); 315 return; 316 } 317 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, 0, 0, reason, 0); 318 319 // discard channel 320 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 321 free (channel); 322 } 323 324 void l2cap_signaling_handler(l2cap_channel_t *channel, uint8_t *packet, uint16_t size){ 325 326 uint8_t code = READ_L2CAP_SIGNALING_CODE( packet ); 327 uint8_t identifier = READ_L2CAP_SIGNALING_IDENTIFIER( packet ); 328 uint16_t result = 0; 329 330 switch (channel->state) { 331 332 case L2CAP_STATE_WAIT_CONNECT_RSP: 333 switch (code){ 334 case CONNECTION_RESPONSE: 335 result = READ_BT_16 (packet, L2CAP_SIGNALING_DATA_OFFSET+4); 336 switch (result) { 337 case 0: 338 // successful connection 339 channel->dest_cid = READ_BT_16(packet, L2CAP_SIGNALING_DATA_OFFSET); 340 channel->sig_id = l2cap_next_sig_id(); 341 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->dest_cid, 0, 4, &config_options); 342 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 343 break; 344 case 1: 345 // connection pending. get some coffee 346 break; 347 default: 348 // map l2cap connection response result to BTstack status enumeration 349 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 350 break; 351 } 352 break; 353 354 case DISCONNECTION_REQUEST: 355 l2cap_handle_disconnect_request(channel, identifier); 356 break; 357 358 default: 359 //@TODO: implement other signaling packets 360 break; 361 } 362 break; 363 364 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ: 365 switch (code) { 366 case CONFIGURE_RESPONSE: 367 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ; 368 break; 369 case CONFIGURE_REQUEST: 370 // accept the other's configuration options 371 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->dest_cid, 0, 0, size - 16, &packet[16]); 372 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP; 373 break; 374 case DISCONNECTION_REQUEST: 375 l2cap_handle_disconnect_request(channel, identifier); 376 break; 377 default: 378 //@TODO: implement other signaling packets 379 break; 380 } 381 break; 382 383 case L2CAP_STATE_WAIT_CONFIG_REQ: 384 switch (code) { 385 case CONFIGURE_REQUEST: 386 // accept the other's configuration options 387 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->dest_cid, 0, 0, size - 16, &packet[16]); 388 channel->state = L2CAP_STATE_OPEN; 389 l2cap_emit_channel_opened(channel, 0); // success 390 break; 391 case DISCONNECTION_REQUEST: 392 l2cap_handle_disconnect_request(channel, identifier); 393 break; 394 default: 395 //@TODO: implement other signaling packets 396 break; 397 } 398 break; 399 400 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP: 401 switch (code) { 402 case CONFIGURE_RESPONSE: 403 channel->state = L2CAP_STATE_OPEN; 404 l2cap_emit_channel_opened(channel, 0); // success 405 break; 406 case DISCONNECTION_REQUEST: 407 l2cap_handle_disconnect_request(channel, identifier); 408 break; 409 default: 410 //@TODO: implement other signaling packets 411 break; 412 } 413 break; 414 415 case L2CAP_STATE_WAIT_DISCONNECT: 416 switch (code) { 417 case DISCONNECTION_RESPONSE: 418 l2cap_finialize_channel_close(channel); 419 break; 420 case DISCONNECTION_REQUEST: 421 l2cap_handle_disconnect_request(channel, identifier); 422 break; 423 default: 424 //@TODO: implement other signaling packets 425 break; 426 } 427 break; 428 429 case L2CAP_STATE_CLOSED: 430 // @TODO handle incoming requests 431 break; 432 433 case L2CAP_STATE_OPEN: 434 switch (code) { 435 case DISCONNECTION_REQUEST: 436 l2cap_handle_disconnect_request(channel, identifier); 437 break; 438 default: 439 //@TODO: implement other signaling packets, e.g. re-configure 440 break; 441 } 442 break; 443 } 444 } 445 446 // finalize closed channel 447 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 448 channel->state = L2CAP_STATE_CLOSED; 449 l2cap_emit_channel_closed(channel); 450 451 // discard channel 452 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 453 free (channel); 454 } 455 456 l2cap_service_t * l2cap_get_service(uint16_t psm){ 457 linked_item_t *it; 458 459 // close open channels 460 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 461 l2cap_service_t * service = ((l2cap_service_t *) it); 462 if ( service->psm == psm){ 463 return service; 464 }; 465 } 466 return NULL; 467 } 468 469 void l2cap_register_service_internal(connection_t *connection, uint16_t psm, uint16_t mtu){ 470 // check for alread registered psm // TODO: emit error event 471 l2cap_service_t *service = l2cap_get_service(psm); 472 if (service) return; 473 474 // alloc structure // TODO: emit error event 475 service = malloc(sizeof(l2cap_service_t)); 476 if (!service) return; 477 478 // fill in 479 service->psm = psm; 480 service->mtu = mtu; 481 service->connection = connection; 482 483 // add to services list 484 linked_list_add(&l2cap_services, (linked_item_t *) service); 485 } 486 487 void l2cap_unregister_service_internal(connection_t *connection, uint16_t psm){ 488 l2cap_service_t *service = l2cap_get_service(psm); 489 if (service) return; 490 linked_list_remove(&l2cap_services, (linked_item_t *) service); 491 free( service ); 492 } 493 494 // 495 void l2cap_close_connection(connection_t *connection){ 496 linked_item_t *it; 497 498 // close open channels 499 l2cap_channel_t * channel; 500 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 501 channel = (l2cap_channel_t *) it; 502 if (channel->connection == connection) { 503 channel->sig_id = l2cap_next_sig_id(); 504 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->dest_cid, channel->source_cid); 505 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 506 } 507 } 508 509 // unregister services 510 l2cap_service_t *service; 511 for (it = (linked_item_t *) &l2cap_services; it ; it = it->next){ 512 channel = (l2cap_channel_t *) it->next; 513 if (service->connection == connection){ 514 it->next = it->next->next; 515 return; 516 } 517 } 518 } 519 520 // notify client 521 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 522 uint8_t event[17]; 523 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 524 event[1] = sizeof(event) - 2; 525 event[2] = status; 526 bt_flip_addr(&event[3], channel->address); 527 bt_store_16(event, 9, channel->handle); 528 bt_store_16(event, 11, channel->psm); 529 bt_store_16(event, 13, channel->source_cid); 530 bt_store_16(event, 15, channel->dest_cid); 531 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 532 socket_connection_send_packet(channel->connection, HCI_EVENT_PACKET, 0, event, sizeof(event)); 533 } 534 535 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 536 uint8_t event[4]; 537 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 538 event[1] = sizeof(event) - 2; 539 bt_store_16(event, 2, channel->source_cid); 540 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 541 socket_connection_send_packet(channel->connection, HCI_EVENT_PACKET, 0, event, sizeof(event)); 542 } 543 544 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 545 uint8_t event[16]; 546 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 547 event[1] = sizeof(event) - 2; 548 bt_flip_addr(&event[2], channel->address); 549 bt_store_16(event, 8, channel->handle); 550 bt_store_16(event, 10, channel->psm); 551 bt_store_16(event, 12, channel->source_cid); 552 bt_store_16(event, 14, channel->dest_cid); 553 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 554 socket_connection_send_packet(channel->connection, HCI_EVENT_PACKET, 0, event, sizeof(event)); 555 } 556 557 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 558 559 // Capturing? 560 if (capture_connection) { 561 socket_connection_send_packet(capture_connection, HCI_ACL_DATA_PACKET, 0, packet, size); 562 return; 563 } 564 565 // forward to higher layers - not needed yet 566 // (*data_packet_handler)(channel_id, packet, size); 567 568 // Get Channel ID and command code 569 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 570 uint8_t code = READ_L2CAP_SIGNALING_CODE( packet ); 571 572 // Get Connection 573 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 574 575 // printf("l2cap_acl_handler channel %u, code %u\n", channel_id, code); 576 577 // Signaling Packet? 578 if (channel_id == 1) { 579 580 if (code < 1 || code >= 8){ 581 // not for a particular channel, and not CONNECTION_REQUEST 582 return; 583 } 584 585 // Get Signaling Identifier 586 uint8_t sig_id = READ_L2CAP_SIGNALING_IDENTIFIER(packet); 587 588 // CONNECTION_REQUEST 589 if (code == CONNECTION_REQUEST){ 590 uint16_t psm = READ_BT_16(packet, L2CAP_SIGNALING_DATA_OFFSET); 591 uint16_t dest_cid = READ_BT_16(packet, L2CAP_SIGNALING_DATA_OFFSET+2); 592 l2cap_handle_connection_request(handle, sig_id, psm, dest_cid); 593 return; 594 } 595 596 // Get potential destination CID 597 uint16_t dest_cid = READ_BT_16(packet, L2CAP_SIGNALING_DATA_OFFSET); 598 599 // Find channel for this sig_id and connection handle 600 linked_item_t *it; 601 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 602 l2cap_channel_t * channel = (l2cap_channel_t *) it; 603 if (channel->handle == handle) { 604 if (code & 1) { 605 // match odd commands by previous signaling identifier 606 if (channel->sig_id == sig_id) { 607 l2cap_signaling_handler( channel, packet, size); 608 } 609 } else { 610 // match even commands by source channel id 611 if (channel->source_cid == dest_cid) { 612 l2cap_signaling_handler( channel, packet, size); 613 } 614 } 615 } 616 } 617 return; 618 } 619 620 // Find channel for this channel_id and connection handle 621 l2cap_channel_t * channel = l2cap_get_channel_for_source_cid(channel_id); 622 if (channel) { 623 socket_connection_send_packet(channel->connection, L2CAP_DATA_PACKET, channel_id, 624 &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 625 } 626 } 627 628 629 void l2cap_send_internal(uint16_t source_cid, uint8_t *data, uint16_t len){ 630 // find channel for source_cid, construct l2cap packet and send 631 l2cap_channel_t * channel = l2cap_get_channel_for_source_cid(source_cid); 632 if (channel) { 633 // 0 - Connection handle : PB=10 : BC=00 634 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 635 // 2 - ACL length 636 bt_store_16(acl_buffer, 2, len + 4); 637 // 4 - L2CAP packet length 638 bt_store_16(acl_buffer, 4, len + 0); 639 // 6 - L2CAP channel DEST 640 bt_store_16(acl_buffer, 6, channel->dest_cid); 641 // 8 - data 642 memcpy(&acl_buffer[8], data, len); 643 // send 644 hci_send_acl_packet(acl_buffer, len+8); 645 } 646 } 647 648 void l2cap_set_capture_connection(connection_t * connection){ 649 capture_connection = connection; 650 } 651 652