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 #include "hci_dump.h" 43 44 #include <stdarg.h> 45 #include <string.h> 46 47 #include <stdio.h> 48 49 // size of HCI ACL + L2CAP Header for regular data packets 50 #define COMPLETE_L2CAP_HEADER 8 51 52 // minimum signaling MTU 53 #define L2CAP_MINIMAL_MTU 48 54 55 // offsets for L2CAP SIGNALING COMMANDS 56 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 57 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 58 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 59 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 60 61 static void null_event_handler(connection_t * connection, uint8_t *packet, uint16_t size); 62 static void null_data_handler(connection_t * connection, uint16_t local_cid, uint8_t *packet, uint16_t size); 63 64 static uint8_t * sig_buffer = NULL; 65 static linked_list_t l2cap_channels = NULL; 66 static linked_list_t l2cap_services = NULL; 67 static uint8_t * acl_buffer = NULL; 68 static void (*event_packet_handler) (connection_t * connection, uint8_t *packet, uint16_t size) = null_event_handler; 69 static void (*data_packet_handler) (connection_t * connection, uint16_t local_cid, uint8_t *packet, uint16_t size) = null_data_handler; 70 static connection_t * capture_connection = NULL; 71 72 static uint8_t config_options[] = { 1, 2, 150, 0}; // mtu = 48 73 74 void l2cap_init(){ 75 sig_buffer = malloc( L2CAP_MINIMAL_MTU ); 76 // acl_buffer = malloc( 255 + 8 ); 77 acl_buffer = malloc( 400 + 8 ); 78 79 // 80 // register callbacks with HCI 81 // 82 hci_register_event_packet_handler(&l2cap_event_handler); 83 hci_register_acl_packet_handler(&l2cap_acl_handler); 84 } 85 86 87 /** Register L2CAP packet handlers */ 88 static void null_event_handler(connection_t * connection, uint8_t *packet, uint16_t size){ 89 } 90 static void null_data_handler(connection_t * connection, uint16_t local_cid, uint8_t *packet, uint16_t size){ 91 } 92 void l2cap_register_event_packet_handler(void (*handler)(connection_t * connection, uint8_t *packet, uint16_t size)){ 93 event_packet_handler = handler; 94 } 95 void l2cap_register_data_packet_handler (void (*handler)(connection_t * connection, uint16_t local_cid, uint8_t *packet, uint16_t size)){ 96 data_packet_handler = handler; 97 } 98 99 // notify client/protocol handler 100 void l2cap_dispatch(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 101 if (channel->packet_handler) { 102 (* (channel->packet_handler))(type, channel->local_cid, data, size); 103 } else { 104 switch (type){ 105 case HCI_EVENT_PACKET: 106 (*event_packet_handler)(channel->connection, data, size); 107 break; 108 case L2CAP_DATA_PACKET: 109 (*data_packet_handler)(channel->connection, channel->local_cid, data, size); 110 break; 111 default: 112 // ?? 113 break; 114 } 115 } 116 } 117 118 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 119 uint8_t event[17]; 120 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 121 event[1] = sizeof(event) - 2; 122 event[2] = status; 123 bt_flip_addr(&event[3], channel->address); 124 bt_store_16(event, 9, channel->handle); 125 bt_store_16(event, 11, channel->psm); 126 bt_store_16(event, 13, channel->local_cid); 127 bt_store_16(event, 15, channel->remote_cid); 128 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 129 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 130 } 131 132 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 133 uint8_t event[4]; 134 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 135 event[1] = sizeof(event) - 2; 136 bt_store_16(event, 2, channel->local_cid); 137 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 138 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 139 } 140 141 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 142 uint8_t event[16]; 143 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 144 event[1] = sizeof(event) - 2; 145 bt_flip_addr(&event[2], channel->address); 146 bt_store_16(event, 8, channel->handle); 147 bt_store_16(event, 10, channel->psm); 148 bt_store_16(event, 12, channel->local_cid); 149 bt_store_16(event, 14, channel->remote_cid); 150 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 151 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 152 } 153 154 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 155 linked_item_t *it; 156 l2cap_channel_t * channel; 157 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 158 channel = (l2cap_channel_t *) it; 159 if ( channel->local_cid == local_cid) { 160 return channel; 161 } 162 } 163 return NULL; 164 } 165 166 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 167 // printf("l2cap_send_signaling_packet type %u\n", cmd); 168 va_list argptr; 169 va_start(argptr, identifier); 170 uint16_t len = l2cap_create_signaling_internal(sig_buffer, handle, cmd, identifier, argptr); 171 va_end(argptr); 172 return hci_send_acl_packet(sig_buffer, len); 173 } 174 175 void l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 176 // find channel for local_cid, construct l2cap packet and send 177 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 178 if (channel) { 179 // 0 - Connection handle : PB=10 : BC=00 180 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 181 // 2 - ACL length 182 bt_store_16(acl_buffer, 2, len + 4); 183 // 4 - L2CAP packet length 184 bt_store_16(acl_buffer, 4, len + 0); 185 // 6 - L2CAP channel DEST 186 bt_store_16(acl_buffer, 6, channel->remote_cid); 187 // 8 - data 188 memcpy(&acl_buffer[8], data, len); 189 // send 190 hci_send_acl_packet(acl_buffer, len+8); 191 } 192 } 193 194 // open outgoing L2CAP channel 195 void l2cap_create_channel_internal(connection_t * connection, bd_addr_t address, uint16_t psm){ 196 197 // alloc structure 198 l2cap_channel_t * chan = malloc(sizeof(l2cap_channel_t)); 199 // TODO: emit error event 200 if (!chan) return; 201 202 // fill in 203 BD_ADDR_COPY(chan->address, address); 204 chan->psm = psm; 205 chan->handle = 0; 206 chan->connection = connection; 207 chan->packet_handler = NULL; 208 chan->remote_mtu = L2CAP_MINIMAL_MTU; 209 210 // set initial state 211 chan->state = L2CAP_STATE_CLOSED; 212 chan->sig_id = L2CAP_SIG_ID_INVALID; 213 214 // add to connections list 215 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 216 217 // send connection request 218 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 219 hci_send_cmd(&hci_create_connection, address, 0x18, 0, 0, 0, 0); 220 } 221 222 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 223 // find channel for local_cid 224 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 225 if (channel) { 226 channel->sig_id = l2cap_next_sig_id(); 227 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 228 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 229 } 230 } 231 232 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 233 linked_item_t *it; 234 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 235 l2cap_channel_t * channel = (l2cap_channel_t *) it; 236 if ( ! BD_ADDR_CMP( channel->address, address) ){ 237 if (channel->state == L2CAP_STATE_CLOSED) { 238 // failure, forward error code 239 l2cap_emit_channel_opened(channel, status); 240 // discard channel 241 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 242 free (channel); 243 } 244 } 245 } 246 } 247 248 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 249 linked_item_t *it; 250 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 251 l2cap_channel_t * channel = (l2cap_channel_t *) it; 252 if ( ! BD_ADDR_CMP( channel->address, address) ){ 253 if (channel->state == L2CAP_STATE_CLOSED) { 254 // success, start l2cap handshake 255 channel->handle = handle; 256 channel->sig_id = l2cap_next_sig_id(); 257 channel->local_cid = l2cap_next_local_cid(); 258 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 259 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->sig_id, channel->psm, channel->local_cid); 260 } 261 } 262 } 263 } 264 265 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 266 267 bd_addr_t address; 268 hci_con_handle_t handle; 269 270 switch(packet[0]){ 271 272 // handle connection complete events 273 case HCI_EVENT_CONNECTION_COMPLETE: 274 bt_flip_addr(address, &packet[5]); 275 if (packet[2] == 0){ 276 handle = READ_BT_16(packet, 3); 277 l2cap_handle_connection_success_for_addr(address, handle); 278 } else { 279 l2cap_handle_connection_failed_for_addr(address, packet[2]); 280 } 281 break; 282 283 // handle successful create connection cancel command 284 case HCI_EVENT_COMMAND_COMPLETE: 285 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 286 if (packet[5] == 0){ 287 bt_flip_addr(address, &packet[6]); 288 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 289 l2cap_handle_connection_failed_for_addr(address, 0x16); 290 } 291 } 292 break; 293 294 // handle disconnection complete events 295 case HCI_EVENT_DISCONNECTION_COMPLETE: 296 // send l2cap disconnect events for all channels on this handle 297 handle = READ_BT_16(packet, 3); 298 linked_item_t *it; 299 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 300 l2cap_channel_t * channel = (l2cap_channel_t *) it; 301 if ( channel->handle == handle ){ 302 l2cap_finialize_channel_close(channel); 303 } 304 } 305 break; 306 307 // HCI Connection Timeouts 308 case L2CAP_EVENT_TIMEOUT_CHECK: 309 if (!capture_connection){ 310 hci_con_handle_t handle = READ_BT_16(packet, 2); 311 linked_item_t *it; 312 l2cap_channel_t * channel; 313 int used = 0; 314 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 315 channel = (l2cap_channel_t *) it; 316 if (channel->handle == handle) { 317 used = 1; 318 } 319 } 320 if (!used) { 321 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 322 } 323 } 324 break; 325 326 default: 327 break; 328 } 329 330 // pass on 331 (*event_packet_handler)(NULL, packet, size); 332 } 333 334 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 335 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, identifier, channel->local_cid, channel->remote_cid); 336 l2cap_finialize_channel_close(channel); 337 } 338 339 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 340 341 // printf("l2cap_handle_connection_request for handle %u, psm %u cid %u\n", handle, psm, source_cid); 342 l2cap_service_t *service = l2cap_get_service(psm); 343 if (!service) { 344 // 0x0002 PSM not supported 345 // printf("l2cap_handle_connection_request no PSM for psm %u/n", psm); 346 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, 0x0002, 0); 347 return; 348 } 349 350 hci_connection_t * hci_connection = connection_for_handle( handle ); 351 if (!hci_connection) { 352 fprintf(stderr, "no hci_connection for handle %u\n", handle); 353 // TODO: emit error 354 return; 355 } 356 // alloc structure 357 // printf("l2cap_handle_connection_request register channel\n"); 358 l2cap_channel_t * channel = malloc(sizeof(l2cap_channel_t)); 359 // TODO: emit error event 360 if (!channel) return; 361 362 // fill in 363 BD_ADDR_COPY(channel->address, hci_connection->address); 364 channel->psm = psm; 365 channel->handle = handle; 366 channel->connection = service->connection; 367 channel->packet_handler = service->packet_handler; 368 channel->local_cid = l2cap_next_local_cid(); 369 channel->remote_cid = source_cid; 370 channel->remote_mtu = L2CAP_MINIMAL_MTU; 371 372 // set initial state 373 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 374 375 // temp. store req sig id 376 channel->sig_id = sig_id; 377 378 // add to connections list 379 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 380 381 // emit incoming connection request 382 l2cap_emit_connection_request(channel); 383 } 384 385 void l2cap_accept_connection_internal(uint16_t local_cid){ 386 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 387 if (!channel) { 388 fprintf(stderr, "l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 389 return; 390 } 391 392 // accept connection 393 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, channel->local_cid, channel->remote_cid, 0, 0); 394 395 // set real sig and state and start config 396 channel->sig_id = l2cap_next_sig_id(); 397 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 398 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 399 400 // printf("new state %u\n", channel->state); 401 } 402 403 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 404 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 405 if (!channel) { 406 fprintf(stderr, "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid,reason); 407 return; 408 } 409 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, 0, 0, reason, 0); 410 411 // discard channel 412 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 413 free (channel); 414 } 415 416 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 417 // accept the other's configuration options 418 uint16_t len = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 419 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 420 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->remote_cid, 0, 0, len-4, &command[8]); 421 } 422 423 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 424 425 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 426 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 427 uint16_t result = 0; 428 429 // printf("signaling handler code %u\n", code); 430 431 switch (channel->state) { 432 433 case L2CAP_STATE_WAIT_CONNECT_RSP: 434 switch (code){ 435 case CONNECTION_RESPONSE: 436 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 437 switch (result) { 438 case 0: 439 // successful connection 440 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 441 channel->sig_id = l2cap_next_sig_id(); 442 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 443 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 444 break; 445 case 1: 446 // connection pending. get some coffee 447 break; 448 default: 449 // map l2cap connection response result to BTstack status enumeration 450 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 451 break; 452 } 453 break; 454 455 case DISCONNECTION_REQUEST: 456 l2cap_handle_disconnect_request(channel, identifier); 457 break; 458 459 default: 460 //@TODO: implement other signaling packets 461 break; 462 } 463 break; 464 465 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ: 466 switch (code) { 467 case CONFIGURE_RESPONSE: 468 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ; 469 break; 470 case CONFIGURE_REQUEST: 471 l2cap_signaling_handle_configure_request(channel, command); 472 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP; 473 break; 474 case DISCONNECTION_REQUEST: 475 l2cap_handle_disconnect_request(channel, identifier); 476 break; 477 default: 478 //@TODO: implement other signaling packets 479 break; 480 } 481 break; 482 483 case L2CAP_STATE_WAIT_CONFIG_REQ: 484 switch (code) { 485 case CONFIGURE_REQUEST: 486 l2cap_signaling_handle_configure_request(channel, command); 487 channel->state = L2CAP_STATE_OPEN; 488 l2cap_emit_channel_opened(channel, 0); // success 489 break; 490 case DISCONNECTION_REQUEST: 491 l2cap_handle_disconnect_request(channel, identifier); 492 break; 493 default: 494 //@TODO: implement other signaling packets 495 break; 496 } 497 break; 498 499 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP: 500 switch (code) { 501 case CONFIGURE_RESPONSE: 502 channel->state = L2CAP_STATE_OPEN; 503 l2cap_emit_channel_opened(channel, 0); // success 504 break; 505 case DISCONNECTION_REQUEST: 506 l2cap_handle_disconnect_request(channel, identifier); 507 break; 508 default: 509 //@TODO: implement other signaling packets 510 break; 511 } 512 break; 513 514 case L2CAP_STATE_WAIT_DISCONNECT: 515 switch (code) { 516 case DISCONNECTION_RESPONSE: 517 l2cap_finialize_channel_close(channel); 518 break; 519 case DISCONNECTION_REQUEST: 520 l2cap_handle_disconnect_request(channel, identifier); 521 break; 522 default: 523 //@TODO: implement other signaling packets 524 break; 525 } 526 break; 527 528 case L2CAP_STATE_CLOSED: 529 // @TODO handle incoming requests 530 break; 531 532 case L2CAP_STATE_OPEN: 533 switch (code) { 534 case DISCONNECTION_REQUEST: 535 l2cap_handle_disconnect_request(channel, identifier); 536 break; 537 default: 538 //@TODO: implement other signaling packets, e.g. re-configure 539 break; 540 } 541 break; 542 } 543 // printf("new state %u\n", channel->state); 544 } 545 546 547 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 548 549 // get code, signalind identifier and command len 550 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 551 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 552 uint16_t len = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 553 554 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 555 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 556 return; 557 } 558 559 // general commands without an assigned channel 560 switch(code) { 561 562 case CONNECTION_REQUEST: { 563 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 564 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 565 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 566 break; 567 } 568 569 case ECHO_REQUEST: { 570 // send back packet 571 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, len, &command[L2CAP_SIGNALING_COMMAND_DATA_OFFSET]); 572 break; 573 } 574 575 case INFORMATION_REQUEST: { 576 // we neither support connectionless L2CAP data nor support any flow control modes yet 577 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 578 if (infoType == 2) { 579 uint32_t features = 0; 580 // extended features request supported, however no features present 581 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, 4, &features); 582 } else { 583 // all other types are not supported 584 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 585 } 586 break;; 587 } 588 589 default: 590 break; 591 } 592 593 594 // Get potential destination CID 595 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 596 597 // Find channel for this sig_id and connection handle 598 linked_item_t *it; 599 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 600 l2cap_channel_t * channel = (l2cap_channel_t *) it; 601 if (channel->handle == handle) { 602 if (code & 1) { 603 // match odd commands by previous signaling identifier 604 if (channel->sig_id == sig_id) { 605 l2cap_signaling_handler_channel(channel, command); 606 } 607 } else { 608 // match even commands by local channel id 609 if (channel->local_cid == dest_cid) { 610 l2cap_signaling_handler_channel(channel, command); 611 } 612 } 613 } 614 } 615 } 616 617 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 618 619 // Capturing? 620 if (capture_connection) { 621 (*data_packet_handler)(capture_connection, 0, packet, size); 622 return; 623 } 624 625 // Get Channel ID 626 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 627 628 // Signaling Packet? 629 if (channel_id == 1) { 630 631 // Get Connection 632 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 633 634 uint16_t command_offset = 8; 635 while (command_offset < size) { 636 637 // handle signaling commands 638 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 639 640 // increment command_offset 641 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 642 } 643 return; 644 } 645 646 // Find channel for this channel_id and connection handle 647 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 648 if (channel) { 649 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 650 } 651 } 652 653 654 // finalize closed channel 655 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 656 channel->state = L2CAP_STATE_CLOSED; 657 l2cap_emit_channel_closed(channel); 658 659 // discard channel 660 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 661 free (channel); 662 } 663 664 l2cap_service_t * l2cap_get_service(uint16_t psm){ 665 linked_item_t *it; 666 667 // close open channels 668 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 669 l2cap_service_t * service = ((l2cap_service_t *) it); 670 if ( service->psm == psm){ 671 return service; 672 }; 673 } 674 return NULL; 675 } 676 677 void l2cap_register_service_internal(connection_t *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 678 // check for alread registered psm // TODO: emit error event 679 l2cap_service_t *service = l2cap_get_service(psm); 680 if (service) return; 681 682 // alloc structure // TODO: emit error event 683 service = malloc(sizeof(l2cap_service_t)); 684 if (!service) return; 685 686 // fill in 687 service->psm = psm; 688 service->mtu = mtu; 689 service->connection = connection; 690 service->packet_handler = packet_handler; 691 692 // add to services list 693 linked_list_add(&l2cap_services, (linked_item_t *) service); 694 } 695 696 void l2cap_unregister_service_internal(connection_t *connection, uint16_t psm){ 697 l2cap_service_t *service = l2cap_get_service(psm); 698 if (!service) return; 699 linked_list_remove(&l2cap_services, (linked_item_t *) service); 700 free(service); 701 } 702 703 // 704 void l2cap_close_connection(connection_t *connection){ 705 linked_item_t *it; 706 707 // close open channels 708 l2cap_channel_t * channel; 709 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 710 channel = (l2cap_channel_t *) it; 711 if (channel->connection == connection) { 712 channel->sig_id = l2cap_next_sig_id(); 713 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 714 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 715 } 716 } 717 718 // unregister services 719 it = (linked_item_t *) &l2cap_services; 720 while (it->next){ 721 l2cap_service_t * service = (l2cap_service_t *) it->next; 722 if (service->connection == connection){ 723 it->next = it->next->next; 724 free(service); 725 } else { 726 it = it->next; 727 } 728 } 729 } 730 731 732 void l2cap_set_capture_connection(connection_t * connection){ 733 capture_connection = connection; 734 } 735 736