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 #define L2CAP_DEFAULT_MTU 672 55 56 // offsets for L2CAP SIGNALING COMMANDS 57 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 58 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 59 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 60 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 61 62 static void null_event_handler(connection_t * connection, uint8_t *packet, uint16_t size); 63 static void null_data_handler(connection_t * connection, uint16_t local_cid, uint8_t *packet, uint16_t size); 64 65 static uint8_t * sig_buffer = NULL; 66 static linked_list_t l2cap_channels = NULL; 67 static linked_list_t l2cap_services = NULL; 68 static uint8_t * acl_buffer = NULL; 69 static void (*event_packet_handler) (connection_t * connection, uint8_t *packet, uint16_t size) = null_event_handler; 70 static void (*data_packet_handler) (connection_t * connection, uint16_t local_cid, uint8_t *packet, uint16_t size) = null_data_handler; 71 static connection_t * capture_connection = NULL; 72 73 static uint8_t config_options[] = { 1, 2, 150, 0}; // mtu = 48 74 75 void l2cap_init(){ 76 sig_buffer = malloc( L2CAP_MINIMAL_MTU ); 77 // acl_buffer = malloc( 255 + 8 ); 78 acl_buffer = malloc( 400 + 8 ); 79 80 // 81 // register callbacks with HCI 82 // 83 hci_register_event_packet_handler(&l2cap_event_handler); 84 hci_register_acl_packet_handler(&l2cap_acl_handler); 85 } 86 87 88 /** Register L2CAP packet handlers */ 89 static void null_event_handler(connection_t * connection, uint8_t *packet, uint16_t size){ 90 } 91 static void null_data_handler(connection_t * connection, uint16_t local_cid, uint8_t *packet, uint16_t size){ 92 } 93 void l2cap_register_event_packet_handler(void (*handler)(connection_t * connection, uint8_t *packet, uint16_t size)){ 94 event_packet_handler = handler; 95 } 96 void l2cap_register_data_packet_handler (void (*handler)(connection_t * connection, uint16_t local_cid, uint8_t *packet, uint16_t size)){ 97 data_packet_handler = handler; 98 } 99 100 // notify client/protocol handler 101 void l2cap_dispatch(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 102 if (channel->packet_handler) { 103 (* (channel->packet_handler))(type, channel->local_cid, data, size); 104 } else { 105 switch (type){ 106 case HCI_EVENT_PACKET: 107 (*event_packet_handler)(channel->connection, data, size); 108 break; 109 case L2CAP_DATA_PACKET: 110 (*data_packet_handler)(channel->connection, channel->local_cid, data, size); 111 break; 112 default: 113 // ?? 114 break; 115 } 116 } 117 } 118 119 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 120 uint8_t event[17]; 121 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 122 event[1] = sizeof(event) - 2; 123 event[2] = status; 124 bt_flip_addr(&event[3], channel->address); 125 bt_store_16(event, 9, channel->handle); 126 bt_store_16(event, 11, channel->psm); 127 bt_store_16(event, 13, channel->local_cid); 128 bt_store_16(event, 15, channel->remote_cid); 129 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 130 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 131 } 132 133 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 134 uint8_t event[4]; 135 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 136 event[1] = sizeof(event) - 2; 137 bt_store_16(event, 2, channel->local_cid); 138 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 139 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 140 } 141 142 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 143 uint8_t event[16]; 144 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 145 event[1] = sizeof(event) - 2; 146 bt_flip_addr(&event[2], channel->address); 147 bt_store_16(event, 8, channel->handle); 148 bt_store_16(event, 10, channel->psm); 149 bt_store_16(event, 12, channel->local_cid); 150 bt_store_16(event, 14, channel->remote_cid); 151 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 152 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 153 } 154 155 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 156 linked_item_t *it; 157 l2cap_channel_t * channel; 158 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 159 channel = (l2cap_channel_t *) it; 160 if ( channel->local_cid == local_cid) { 161 return channel; 162 } 163 } 164 return NULL; 165 } 166 167 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 168 // printf("l2cap_send_signaling_packet type %u\n", cmd); 169 va_list argptr; 170 va_start(argptr, identifier); 171 uint16_t len = l2cap_create_signaling_internal(sig_buffer, handle, cmd, identifier, argptr); 172 va_end(argptr); 173 return hci_send_acl_packet(sig_buffer, len); 174 } 175 176 void l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 177 // find channel for local_cid, construct l2cap packet and send 178 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 179 if (channel) { 180 // 0 - Connection handle : PB=10 : BC=00 181 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 182 // 2 - ACL length 183 bt_store_16(acl_buffer, 2, len + 4); 184 // 4 - L2CAP packet length 185 bt_store_16(acl_buffer, 4, len + 0); 186 // 6 - L2CAP channel DEST 187 bt_store_16(acl_buffer, 6, channel->remote_cid); 188 // 8 - data 189 memcpy(&acl_buffer[8], data, len); 190 // send 191 hci_send_acl_packet(acl_buffer, len+8); 192 } 193 } 194 195 // open outgoing L2CAP channel 196 void l2cap_create_channel_internal(connection_t * connection, bd_addr_t address, uint16_t psm){ 197 198 // alloc structure 199 l2cap_channel_t * chan = malloc(sizeof(l2cap_channel_t)); 200 // TODO: emit error event 201 if (!chan) return; 202 203 // fill in 204 BD_ADDR_COPY(chan->address, address); 205 chan->psm = psm; 206 chan->handle = 0; 207 chan->connection = connection; 208 chan->packet_handler = NULL; 209 chan->remote_mtu = L2CAP_MINIMAL_MTU; 210 211 // set initial state 212 chan->state = L2CAP_STATE_CLOSED; 213 chan->sig_id = L2CAP_SIG_ID_INVALID; 214 215 // add to connections list 216 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 217 218 // send connection request 219 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 220 hci_send_cmd(&hci_create_connection, address, 0x18, 0, 0, 0, 0); 221 } 222 223 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 224 // find channel for local_cid 225 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 226 if (channel) { 227 channel->sig_id = l2cap_next_sig_id(); 228 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 229 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 230 } 231 } 232 233 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 234 linked_item_t *it; 235 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 236 l2cap_channel_t * channel = (l2cap_channel_t *) it; 237 if ( ! BD_ADDR_CMP( channel->address, address) ){ 238 if (channel->state == L2CAP_STATE_CLOSED) { 239 // failure, forward error code 240 l2cap_emit_channel_opened(channel, status); 241 // discard channel 242 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 243 free (channel); 244 } 245 } 246 } 247 } 248 249 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 250 linked_item_t *it; 251 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 252 l2cap_channel_t * channel = (l2cap_channel_t *) it; 253 if ( ! BD_ADDR_CMP( channel->address, address) ){ 254 if (channel->state == L2CAP_STATE_CLOSED) { 255 // success, start l2cap handshake 256 channel->handle = handle; 257 channel->sig_id = l2cap_next_sig_id(); 258 channel->local_cid = l2cap_next_local_cid(); 259 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 260 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->sig_id, channel->psm, channel->local_cid); 261 } 262 } 263 } 264 } 265 266 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 267 268 bd_addr_t address; 269 hci_con_handle_t handle; 270 271 switch(packet[0]){ 272 273 // handle connection complete events 274 case HCI_EVENT_CONNECTION_COMPLETE: 275 bt_flip_addr(address, &packet[5]); 276 if (packet[2] == 0){ 277 handle = READ_BT_16(packet, 3); 278 l2cap_handle_connection_success_for_addr(address, handle); 279 } else { 280 l2cap_handle_connection_failed_for_addr(address, packet[2]); 281 } 282 break; 283 284 // handle successful create connection cancel command 285 case HCI_EVENT_COMMAND_COMPLETE: 286 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 287 if (packet[5] == 0){ 288 bt_flip_addr(address, &packet[6]); 289 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 290 l2cap_handle_connection_failed_for_addr(address, 0x16); 291 } 292 } 293 break; 294 295 // handle disconnection complete events 296 case HCI_EVENT_DISCONNECTION_COMPLETE: 297 // send l2cap disconnect events for all channels on this handle 298 handle = READ_BT_16(packet, 3); 299 linked_item_t *it; 300 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 301 l2cap_channel_t * channel = (l2cap_channel_t *) it; 302 if ( channel->handle == handle ){ 303 l2cap_finialize_channel_close(channel); 304 } 305 } 306 break; 307 308 // HCI Connection Timeouts 309 case L2CAP_EVENT_TIMEOUT_CHECK: 310 if (!capture_connection){ 311 hci_con_handle_t handle = READ_BT_16(packet, 2); 312 linked_item_t *it; 313 l2cap_channel_t * channel; 314 int used = 0; 315 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 316 channel = (l2cap_channel_t *) it; 317 if (channel->handle == handle) { 318 used = 1; 319 } 320 } 321 if (!used) { 322 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 323 } 324 } 325 break; 326 327 default: 328 break; 329 } 330 331 // pass on 332 (*event_packet_handler)(NULL, packet, size); 333 } 334 335 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 336 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, identifier, channel->local_cid, channel->remote_cid); 337 l2cap_finialize_channel_close(channel); 338 } 339 340 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 341 342 // printf("l2cap_handle_connection_request for handle %u, psm %u cid %u\n", handle, psm, source_cid); 343 l2cap_service_t *service = l2cap_get_service(psm); 344 if (!service) { 345 // 0x0002 PSM not supported 346 // printf("l2cap_handle_connection_request no PSM for psm %u/n", psm); 347 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, 0x0002, 0); 348 return; 349 } 350 351 hci_connection_t * hci_connection = connection_for_handle( handle ); 352 if (!hci_connection) { 353 fprintf(stderr, "no hci_connection for handle %u\n", handle); 354 // TODO: emit error 355 return; 356 } 357 // alloc structure 358 // printf("l2cap_handle_connection_request register channel\n"); 359 l2cap_channel_t * channel = malloc(sizeof(l2cap_channel_t)); 360 // TODO: emit error event 361 if (!channel) return; 362 363 // fill in 364 BD_ADDR_COPY(channel->address, hci_connection->address); 365 channel->psm = psm; 366 channel->handle = handle; 367 channel->connection = service->connection; 368 channel->packet_handler = service->packet_handler; 369 channel->local_cid = l2cap_next_local_cid(); 370 channel->remote_cid = source_cid; 371 channel->remote_mtu = L2CAP_MINIMAL_MTU; 372 373 // set initial state 374 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 375 376 // temp. store req sig id 377 channel->sig_id = sig_id; 378 379 // add to connections list 380 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 381 382 // emit incoming connection request 383 l2cap_emit_connection_request(channel); 384 } 385 386 void l2cap_accept_connection_internal(uint16_t local_cid){ 387 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 388 if (!channel) { 389 fprintf(stderr, "l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 390 return; 391 } 392 393 // accept connection 394 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, channel->local_cid, channel->remote_cid, 0, 0); 395 396 // set real sig and state and start config 397 channel->sig_id = l2cap_next_sig_id(); 398 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 399 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 400 401 // printf("new state %u\n", channel->state); 402 } 403 404 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 405 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 406 if (!channel) { 407 fprintf(stderr, "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid,reason); 408 return; 409 } 410 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, 0, 0, reason, 0); 411 412 // discard channel 413 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 414 free (channel); 415 } 416 417 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 418 // accept the other's configuration options 419 uint16_t len = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 420 uint16_t pos = 4; 421 while (pos < len){ 422 uint8_t type = command[pos++]; 423 uint8_t length = command[pos++]; 424 // MTU { type(8): 1, len(8):2, MTU(16) } 425 if ((type & 0x7f) == 1 && length == 2){ 426 channel->remote_mtu = READ_BT_16(command, pos); 427 } 428 pos += length; 429 } 430 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 431 // send back received options 432 // l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->remote_cid, 0, 0, len-4, &command[8]); 433 // send back OK 434 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->remote_cid, 0, 0, 0, NULL); 435 } 436 437 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 438 439 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 440 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 441 uint16_t result = 0; 442 443 // printf("signaling handler code %u\n", code); 444 445 switch (channel->state) { 446 447 case L2CAP_STATE_WAIT_CONNECT_RSP: 448 switch (code){ 449 case CONNECTION_RESPONSE: 450 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 451 switch (result) { 452 case 0: 453 // successful connection 454 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 455 channel->sig_id = l2cap_next_sig_id(); 456 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 457 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 458 break; 459 case 1: 460 // connection pending. get some coffee 461 break; 462 default: 463 // map l2cap connection response result to BTstack status enumeration 464 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 465 break; 466 } 467 break; 468 469 case DISCONNECTION_REQUEST: 470 l2cap_handle_disconnect_request(channel, identifier); 471 break; 472 473 default: 474 //@TODO: implement other signaling packets 475 break; 476 } 477 break; 478 479 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ: 480 switch (code) { 481 case CONFIGURE_RESPONSE: 482 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ; 483 break; 484 case CONFIGURE_REQUEST: 485 l2cap_signaling_handle_configure_request(channel, command); 486 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP; 487 break; 488 case DISCONNECTION_REQUEST: 489 l2cap_handle_disconnect_request(channel, identifier); 490 break; 491 default: 492 //@TODO: implement other signaling packets 493 break; 494 } 495 break; 496 497 case L2CAP_STATE_WAIT_CONFIG_REQ: 498 switch (code) { 499 case CONFIGURE_REQUEST: 500 l2cap_signaling_handle_configure_request(channel, command); 501 channel->state = L2CAP_STATE_OPEN; 502 l2cap_emit_channel_opened(channel, 0); // success 503 break; 504 case DISCONNECTION_REQUEST: 505 l2cap_handle_disconnect_request(channel, identifier); 506 break; 507 default: 508 //@TODO: implement other signaling packets 509 break; 510 } 511 break; 512 513 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP: 514 switch (code) { 515 case CONFIGURE_RESPONSE: 516 channel->state = L2CAP_STATE_OPEN; 517 l2cap_emit_channel_opened(channel, 0); // success 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_WAIT_DISCONNECT: 529 switch (code) { 530 case DISCONNECTION_RESPONSE: 531 l2cap_finialize_channel_close(channel); 532 break; 533 case DISCONNECTION_REQUEST: 534 l2cap_handle_disconnect_request(channel, identifier); 535 break; 536 default: 537 //@TODO: implement other signaling packets 538 break; 539 } 540 break; 541 542 case L2CAP_STATE_CLOSED: 543 // @TODO handle incoming requests 544 break; 545 546 case L2CAP_STATE_OPEN: 547 switch (code) { 548 case DISCONNECTION_REQUEST: 549 l2cap_handle_disconnect_request(channel, identifier); 550 break; 551 default: 552 //@TODO: implement other signaling packets, e.g. re-configure 553 break; 554 } 555 break; 556 } 557 // printf("new state %u\n", channel->state); 558 } 559 560 561 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 562 563 // get code, signalind identifier and command len 564 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 565 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 566 uint16_t len = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 567 568 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 569 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 570 return; 571 } 572 573 // general commands without an assigned channel 574 switch(code) { 575 576 case CONNECTION_REQUEST: { 577 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 578 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 579 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 580 break; 581 } 582 583 case ECHO_REQUEST: { 584 // send back packet 585 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, len, &command[L2CAP_SIGNALING_COMMAND_DATA_OFFSET]); 586 break; 587 } 588 589 case INFORMATION_REQUEST: { 590 // we neither support connectionless L2CAP data nor support any flow control modes yet 591 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 592 if (infoType == 2) { 593 uint32_t features = 0; 594 // extended features request supported, however no features present 595 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, 4, &features); 596 } else { 597 // all other types are not supported 598 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 599 } 600 break;; 601 } 602 603 default: 604 break; 605 } 606 607 608 // Get potential destination CID 609 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 610 611 // Find channel for this sig_id and connection handle 612 linked_item_t *it; 613 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 614 l2cap_channel_t * channel = (l2cap_channel_t *) it; 615 if (channel->handle == handle) { 616 if (code & 1) { 617 // match odd commands by previous signaling identifier 618 if (channel->sig_id == sig_id) { 619 l2cap_signaling_handler_channel(channel, command); 620 } 621 } else { 622 // match even commands by local channel id 623 if (channel->local_cid == dest_cid) { 624 l2cap_signaling_handler_channel(channel, command); 625 } 626 } 627 } 628 } 629 } 630 631 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 632 633 // Capturing? 634 if (capture_connection) { 635 (*data_packet_handler)(capture_connection, 0, packet, size); 636 return; 637 } 638 639 // Get Channel ID 640 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 641 642 // Signaling Packet? 643 if (channel_id == 1) { 644 645 // Get Connection 646 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 647 648 uint16_t command_offset = 8; 649 while (command_offset < size) { 650 651 // handle signaling commands 652 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 653 654 // increment command_offset 655 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 656 } 657 return; 658 } 659 660 // Find channel for this channel_id and connection handle 661 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 662 if (channel) { 663 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 664 } 665 } 666 667 668 // finalize closed channel 669 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 670 channel->state = L2CAP_STATE_CLOSED; 671 l2cap_emit_channel_closed(channel); 672 673 // discard channel 674 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 675 free (channel); 676 } 677 678 l2cap_service_t * l2cap_get_service(uint16_t psm){ 679 linked_item_t *it; 680 681 // close open channels 682 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 683 l2cap_service_t * service = ((l2cap_service_t *) it); 684 if ( service->psm == psm){ 685 return service; 686 }; 687 } 688 return NULL; 689 } 690 691 void l2cap_register_service_internal(connection_t *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 692 // check for alread registered psm // TODO: emit error event 693 l2cap_service_t *service = l2cap_get_service(psm); 694 if (service) return; 695 696 // alloc structure // TODO: emit error event 697 service = malloc(sizeof(l2cap_service_t)); 698 if (!service) return; 699 700 // fill in 701 service->psm = psm; 702 service->mtu = mtu; 703 service->connection = connection; 704 service->packet_handler = packet_handler; 705 706 // add to services list 707 linked_list_add(&l2cap_services, (linked_item_t *) service); 708 } 709 710 void l2cap_unregister_service_internal(connection_t *connection, uint16_t psm){ 711 l2cap_service_t *service = l2cap_get_service(psm); 712 if (!service) return; 713 linked_list_remove(&l2cap_services, (linked_item_t *) service); 714 free(service); 715 } 716 717 // 718 void l2cap_close_connection(connection_t *connection){ 719 linked_item_t *it; 720 721 // close open channels 722 l2cap_channel_t * channel; 723 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 724 channel = (l2cap_channel_t *) it; 725 if (channel->connection == connection) { 726 channel->sig_id = l2cap_next_sig_id(); 727 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 728 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 729 } 730 } 731 732 // unregister services 733 it = (linked_item_t *) &l2cap_services; 734 while (it->next){ 735 l2cap_service_t * service = (l2cap_service_t *) it->next; 736 if (service->connection == connection){ 737 it->next = it->next->next; 738 free(service); 739 } else { 740 it = it->next; 741 } 742 } 743 } 744 745 746 void l2cap_set_capture_connection(connection_t * connection){ 747 capture_connection = connection; 748 } 749 750