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 #include "debug.h" 44 45 #include <stdarg.h> 46 #include <string.h> 47 48 #include <stdio.h> 49 50 // size of HCI ACL + L2CAP Header for regular data packets 51 #define COMPLETE_L2CAP_HEADER 8 52 53 // minimum signaling MTU 54 #define L2CAP_MINIMAL_MTU 48 55 #define L2CAP_DEFAULT_MTU 672 56 57 // nr of buffered acl packets in outgoing queue to get max performance 58 #define NR_BUFFERED_ACL_PACKETS 3 59 60 // offsets for L2CAP SIGNALING COMMANDS 61 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 62 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 63 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 64 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 65 66 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); 67 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size); 68 69 static uint8_t * sig_buffer = NULL; 70 static linked_list_t l2cap_channels = NULL; 71 static linked_list_t l2cap_services = NULL; 72 static uint8_t * acl_buffer = NULL; 73 static void (*packet_handler) (void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) = null_packet_handler; 74 75 void l2cap_init(){ 76 sig_buffer = malloc( L2CAP_MINIMAL_MTU ); 77 acl_buffer = malloc( HCI_ACL_3DH5_SIZE); 78 79 // 80 // register callback with HCI 81 // 82 hci_register_packet_handler(&l2cap_packet_handler); 83 } 84 85 86 /** Register L2CAP packet handlers */ 87 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 88 } 89 void l2cap_register_packet_handler(void (*handler)(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 90 packet_handler = handler; 91 } 92 93 // notify client/protocol handler 94 void l2cap_dispatch(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 95 if (channel->packet_handler) { 96 (* (channel->packet_handler))(type, channel->local_cid, data, size); 97 } else { 98 (*packet_handler)(channel->connection, type, channel->local_cid, data, size); 99 } 100 } 101 102 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 103 uint8_t event[21]; 104 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 105 event[1] = sizeof(event) - 2; 106 event[2] = status; 107 bt_flip_addr(&event[3], channel->address); 108 bt_store_16(event, 9, channel->handle); 109 bt_store_16(event, 11, channel->psm); 110 bt_store_16(event, 13, channel->local_cid); 111 bt_store_16(event, 15, channel->remote_cid); 112 bt_store_16(event, 17, channel->local_mtu); 113 bt_store_16(event, 19, channel->remote_mtu); 114 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 115 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 116 } 117 118 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 119 uint8_t event[4]; 120 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 121 event[1] = sizeof(event) - 2; 122 bt_store_16(event, 2, channel->local_cid); 123 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 124 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 125 } 126 127 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 128 uint8_t event[16]; 129 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 130 event[1] = sizeof(event) - 2; 131 bt_flip_addr(&event[2], channel->address); 132 bt_store_16(event, 8, channel->handle); 133 bt_store_16(event, 10, channel->psm); 134 bt_store_16(event, 12, channel->local_cid); 135 bt_store_16(event, 14, channel->remote_cid); 136 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 137 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 138 } 139 140 void l2cap_emit_credits(l2cap_channel_t *channel, uint8_t credits) { 141 // track credits 142 channel->packets_granted += credits; 143 // log_dbg("l2cap_emit_credits for cid %u, credits now: %u (+%u)\n", channel->local_cid, channel->packets_granted, credits); 144 145 uint8_t event[5]; 146 event[0] = L2CAP_EVENT_CREDITS; 147 event[1] = sizeof(event) - 2; 148 bt_store_16(event, 2, channel->local_cid); 149 event[4] = credits; 150 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 151 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 152 } 153 154 void l2cap_hand_out_credits(void){ 155 linked_item_t *it; 156 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 157 if (!hci_number_free_acl_slots()) return; 158 l2cap_channel_t * channel = (l2cap_channel_t *) it; 159 if (channel->state != L2CAP_STATE_OPEN) continue; 160 if (hci_number_outgoing_packets(channel->handle) < NR_BUFFERED_ACL_PACKETS && channel->packets_granted == 0) { 161 l2cap_emit_credits(channel, 1); 162 } 163 } 164 } 165 166 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 167 linked_item_t *it; 168 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 169 l2cap_channel_t * channel = (l2cap_channel_t *) it; 170 if ( channel->local_cid == local_cid) { 171 return channel; 172 } 173 } 174 return NULL; 175 } 176 177 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 178 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 179 if (channel) { 180 return channel->remote_mtu; 181 } 182 return 0; 183 } 184 185 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 186 // log_dbg("l2cap_send_signaling_packet type %u\n", cmd); 187 va_list argptr; 188 va_start(argptr, identifier); 189 uint16_t len = l2cap_create_signaling_internal(sig_buffer, handle, cmd, identifier, argptr); 190 va_end(argptr); 191 return hci_send_acl_packet(sig_buffer, len); 192 } 193 194 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 195 196 // check for free places on BT module 197 if (!hci_number_free_acl_slots()) { 198 log_dbg("l2cap_send_internal cid %u, BT module full <-----\n", local_cid); 199 return -1; 200 } 201 int err = 0; 202 203 // find channel for local_cid, construct l2cap packet and send 204 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 205 if (channel) { 206 if (channel->packets_granted > 0){ 207 --channel->packets_granted; 208 // log_dbg("l2cap_send_internal cid %u, 1 credit used, credits left %u;\n", 209 // local_cid, channel->packets_granted); 210 } else { 211 log_err("l2cap_send_internal cid %u, no credits!\n", local_cid); 212 } 213 214 // 0 - Connection handle : PB=10 : BC=00 215 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 216 // 2 - ACL length 217 bt_store_16(acl_buffer, 2, len + 4); 218 // 4 - L2CAP packet length 219 bt_store_16(acl_buffer, 4, len + 0); 220 // 6 - L2CAP channel DEST 221 bt_store_16(acl_buffer, 6, channel->remote_cid); 222 // 8 - data 223 memcpy(&acl_buffer[8], data, len); 224 225 // send 226 err = hci_send_acl_packet(acl_buffer, len+8); 227 } 228 229 l2cap_hand_out_credits(); 230 231 return err; 232 } 233 234 // open outgoing L2CAP channel 235 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 236 bd_addr_t address, uint16_t psm, uint16_t mtu){ 237 238 // alloc structure 239 l2cap_channel_t * chan = malloc(sizeof(l2cap_channel_t)); 240 // TODO: emit error event 241 if (!chan) return; 242 243 // limit local mtu to max acl packet length 244 if (mtu > hci_max_acl_data_packet_length()) { 245 mtu = hci_max_acl_data_packet_length(); 246 } 247 248 // fill in 249 BD_ADDR_COPY(chan->address, address); 250 chan->psm = psm; 251 chan->handle = 0; 252 chan->connection = connection; 253 chan->packet_handler = packet_handler; 254 chan->remote_mtu = L2CAP_MINIMAL_MTU; 255 chan->local_mtu = mtu; 256 257 // flow control 258 chan->packets_granted = 0; 259 260 // set initial state 261 chan->state = L2CAP_STATE_CLOSED; 262 chan->sig_id = L2CAP_SIG_ID_INVALID; 263 264 // add to connections list 265 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 266 267 // send connection request 268 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 269 hci_send_cmd(&hci_create_connection, address, 0xcc18, 0, 0, 0, 1); 270 } 271 272 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 273 // find channel for local_cid 274 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 275 if (channel) { 276 channel->sig_id = l2cap_next_sig_id(); 277 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 278 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 279 } 280 } 281 282 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 283 linked_item_t *it = (linked_item_t *) &l2cap_channels; 284 while (it->next){ 285 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 286 if ( ! BD_ADDR_CMP( channel->address, address) ){ 287 if (channel->state == L2CAP_STATE_CLOSED) { 288 // failure, forward error code 289 l2cap_emit_channel_opened(channel, status); 290 // discard channel 291 it->next = it->next->next; 292 free (channel); 293 } 294 } else { 295 it = it->next; 296 } 297 } 298 } 299 300 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 301 linked_item_t *it; 302 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 303 l2cap_channel_t * channel = (l2cap_channel_t *) it; 304 if ( ! BD_ADDR_CMP( channel->address, address) ){ 305 if (channel->state == L2CAP_STATE_CLOSED) { 306 // success, start l2cap handshake 307 channel->handle = handle; 308 channel->sig_id = l2cap_next_sig_id(); 309 channel->local_cid = l2cap_next_local_cid(); 310 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 311 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->sig_id, channel->psm, channel->local_cid); 312 } 313 } 314 } 315 } 316 317 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 318 319 bd_addr_t address; 320 hci_con_handle_t handle; 321 linked_item_t *it; 322 323 switch(packet[0]){ 324 325 // handle connection complete events 326 case HCI_EVENT_CONNECTION_COMPLETE: 327 bt_flip_addr(address, &packet[5]); 328 if (packet[2] == 0){ 329 handle = READ_BT_16(packet, 3); 330 l2cap_handle_connection_success_for_addr(address, handle); 331 } else { 332 l2cap_handle_connection_failed_for_addr(address, packet[2]); 333 } 334 break; 335 336 // handle successful create connection cancel command 337 case HCI_EVENT_COMMAND_COMPLETE: 338 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 339 if (packet[5] == 0){ 340 bt_flip_addr(address, &packet[6]); 341 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 342 l2cap_handle_connection_failed_for_addr(address, 0x16); 343 } 344 } 345 break; 346 347 // handle disconnection complete events 348 case HCI_EVENT_DISCONNECTION_COMPLETE: 349 // send l2cap disconnect events for all channels on this handle 350 handle = READ_BT_16(packet, 3); 351 it = (linked_item_t *) &l2cap_channels; 352 while (it->next){ 353 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 354 if ( channel->handle == handle ){ 355 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 356 it->next = it->next->next; 357 l2cap_emit_channel_closed(channel); 358 free (channel); 359 } else { 360 it = it->next; 361 } 362 } 363 break; 364 365 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 366 l2cap_hand_out_credits(); 367 break; 368 369 // HCI Connection Timeouts 370 case L2CAP_EVENT_TIMEOUT_CHECK: 371 handle = READ_BT_16(packet, 2); 372 if (hci_authentication_active_for_handle(handle)) break; 373 l2cap_channel_t * channel; 374 int used = 0; 375 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 376 channel = (l2cap_channel_t *) it; 377 if (channel->handle == handle) { 378 used = 1; 379 } 380 } 381 if (!used) { 382 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 383 } 384 break; 385 386 default: 387 break; 388 } 389 390 // pass on 391 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 392 } 393 394 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 395 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, identifier, channel->local_cid, channel->remote_cid); 396 l2cap_finialize_channel_close(channel); 397 } 398 399 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 400 401 // log_dbg("l2cap_handle_connection_request for handle %u, psm %u cid %u\n", handle, psm, source_cid); 402 l2cap_service_t *service = l2cap_get_service(psm); 403 if (!service) { 404 // 0x0002 PSM not supported 405 // log_dbg("l2cap_handle_connection_request no PSM for psm %u/n", psm); 406 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, 0x0002, 0); 407 return; 408 } 409 410 hci_connection_t * hci_connection = connection_for_handle( handle ); 411 if (!hci_connection) { 412 log_err("no hci_connection for handle %u\n", handle); 413 // TODO: emit error 414 return; 415 } 416 // alloc structure 417 // log_dbg("l2cap_handle_connection_request register channel\n"); 418 l2cap_channel_t * channel = malloc(sizeof(l2cap_channel_t)); 419 // TODO: emit error event 420 if (!channel) return; 421 422 // fill in 423 BD_ADDR_COPY(channel->address, hci_connection->address); 424 channel->psm = psm; 425 channel->handle = handle; 426 channel->connection = service->connection; 427 channel->packet_handler = service->packet_handler; 428 channel->local_cid = l2cap_next_local_cid(); 429 channel->remote_cid = source_cid; 430 channel->local_mtu = service->mtu; 431 channel->remote_mtu = L2CAP_DEFAULT_MTU; 432 433 // limit local mtu to max acl packet length 434 if (channel->local_mtu > hci_max_acl_data_packet_length()) { 435 channel->local_mtu = hci_max_acl_data_packet_length(); 436 } 437 438 // set initial state 439 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 440 441 // temp. store req sig id 442 channel->sig_id = sig_id; 443 444 // add to connections list 445 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 446 447 // emit incoming connection request 448 l2cap_emit_connection_request(channel); 449 } 450 451 void l2cap_accept_connection_internal(uint16_t local_cid){ 452 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 453 if (!channel) { 454 log_err("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 455 return; 456 } 457 458 // accept connection 459 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, channel->local_cid, channel->remote_cid, 0, 0); 460 461 // set real sig and state and start config 462 channel->sig_id = l2cap_next_sig_id(); 463 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 464 uint8_t config_options[4]; 465 config_options[0] = 1; // MTU 466 config_options[1] = 2; // len param 467 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 468 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 469 470 // log_dbg("new state %u\n", channel->state); 471 } 472 473 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 474 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 475 if (!channel) { 476 log_err( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 477 return; 478 } 479 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, 0, 0, reason, 0); 480 481 // discard channel 482 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 483 free (channel); 484 } 485 486 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 487 // accept the other's configuration options 488 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 489 uint16_t pos = 8; 490 while (pos < end_pos){ 491 uint8_t type = command[pos++]; 492 uint8_t length = command[pos++]; 493 // MTU { type(8): 1, len(8):2, MTU(16) } 494 if ((type & 0x7f) == 1 && length == 2){ 495 channel->remote_mtu = READ_BT_16(command, pos); 496 // log_dbg("l2cap cid %u, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 497 } 498 pos += length; 499 } 500 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 501 // send back OK 502 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->remote_cid, 0, 0, 0, NULL); 503 } 504 505 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 506 507 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 508 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 509 uint16_t result = 0; 510 uint8_t config_options[4]; 511 512 // log_dbg("signaling handler code %u\n", code); 513 514 switch (channel->state) { 515 516 case L2CAP_STATE_WAIT_CONNECT_RSP: 517 switch (code){ 518 case CONNECTION_RESPONSE: 519 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 520 switch (result) { 521 case 0: 522 // successful connection 523 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 524 channel->sig_id = l2cap_next_sig_id(); 525 config_options[0] = 1; // MTU 526 config_options[1] = 2; // len param 527 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 528 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 529 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 530 531 #if 0 532 channel->state = L2CAP_STATE_OPEN; 533 l2cap_emit_channel_opened(channel, 0); // success 534 l2cap_emit_credits(channel, 1); 535 #endif 536 break; 537 case 1: 538 // connection pending. get some coffee 539 break; 540 default: 541 // channel closed 542 channel->state = L2CAP_STATE_CLOSED; 543 544 // map l2cap connection response result to BTstack status enumeration 545 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 546 547 // drop link key if security block 548 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 549 hci_drop_link_key_for_bd_addr(&channel->address); 550 } 551 552 // discard channel 553 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 554 free (channel); 555 break; 556 } 557 break; 558 559 case DISCONNECTION_REQUEST: 560 l2cap_handle_disconnect_request(channel, identifier); 561 break; 562 563 default: 564 //@TODO: implement other signaling packets 565 break; 566 } 567 break; 568 569 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ: 570 switch (code) { 571 case CONFIGURE_RESPONSE: 572 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ; 573 break; 574 case CONFIGURE_REQUEST: 575 l2cap_signaling_handle_configure_request(channel, command); 576 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP; 577 break; 578 case DISCONNECTION_REQUEST: 579 l2cap_handle_disconnect_request(channel, identifier); 580 break; 581 default: 582 //@TODO: implement other signaling packets 583 break; 584 } 585 break; 586 587 case L2CAP_STATE_WAIT_CONFIG_REQ: 588 switch (code) { 589 case CONFIGURE_REQUEST: 590 l2cap_signaling_handle_configure_request(channel, command); 591 channel->state = L2CAP_STATE_OPEN; 592 l2cap_emit_channel_opened(channel, 0); // success 593 l2cap_emit_credits(channel, 1); 594 break; 595 case DISCONNECTION_REQUEST: 596 l2cap_handle_disconnect_request(channel, identifier); 597 break; 598 default: 599 //@TODO: implement other signaling packets 600 break; 601 } 602 break; 603 604 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP: 605 switch (code) { 606 case CONFIGURE_RESPONSE: 607 channel->state = L2CAP_STATE_OPEN; 608 l2cap_emit_channel_opened(channel, 0); // success 609 l2cap_emit_credits(channel, 1); 610 break; 611 case DISCONNECTION_REQUEST: 612 l2cap_handle_disconnect_request(channel, identifier); 613 break; 614 default: 615 //@TODO: implement other signaling packets 616 break; 617 } 618 break; 619 620 case L2CAP_STATE_WAIT_DISCONNECT: 621 switch (code) { 622 case DISCONNECTION_RESPONSE: 623 l2cap_finialize_channel_close(channel); 624 break; 625 case DISCONNECTION_REQUEST: 626 l2cap_handle_disconnect_request(channel, identifier); 627 break; 628 default: 629 //@TODO: implement other signaling packets 630 break; 631 } 632 break; 633 634 case L2CAP_STATE_CLOSED: 635 // @TODO handle incoming requests 636 break; 637 638 case L2CAP_STATE_OPEN: 639 switch (code) { 640 case DISCONNECTION_REQUEST: 641 l2cap_handle_disconnect_request(channel, identifier); 642 break; 643 default: 644 //@TODO: implement other signaling packets, e.g. re-configure 645 break; 646 } 647 break; 648 default: 649 break; 650 } 651 // log_dbg("new state %u\n", channel->state); 652 } 653 654 655 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 656 657 // get code, signalind identifier and command len 658 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 659 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 660 uint16_t len = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 661 662 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 663 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 664 return; 665 } 666 667 // general commands without an assigned channel 668 switch(code) { 669 670 case CONNECTION_REQUEST: { 671 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 672 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 673 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 674 break; 675 } 676 677 case ECHO_REQUEST: { 678 // send back packet 679 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, len, &command[L2CAP_SIGNALING_COMMAND_DATA_OFFSET]); 680 break; 681 } 682 683 case INFORMATION_REQUEST: { 684 // we neither support connectionless L2CAP data nor support any flow control modes yet 685 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 686 if (infoType == 2) { 687 uint32_t features = 0; 688 // extended features request supported, however no features present 689 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, 4, &features); 690 } else { 691 // all other types are not supported 692 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 693 } 694 break;; 695 } 696 697 default: 698 break; 699 } 700 701 702 // Get potential destination CID 703 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 704 705 // Find channel for this sig_id and connection handle 706 linked_item_t *it; 707 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 708 l2cap_channel_t * channel = (l2cap_channel_t *) it; 709 if (channel->handle == handle) { 710 if (code & 1) { 711 // match odd commands by previous signaling identifier 712 if (channel->sig_id == sig_id) { 713 l2cap_signaling_handler_channel(channel, command); 714 break; 715 } 716 } else { 717 // match even commands by local channel id 718 if (channel->local_cid == dest_cid) { 719 l2cap_signaling_handler_channel(channel, command); 720 break; 721 } 722 } 723 } 724 } 725 } 726 727 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 728 729 // Get Channel ID 730 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 731 732 // Signaling Packet? 733 if (channel_id == 1) { 734 735 // Get Connection 736 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 737 738 uint16_t command_offset = 8; 739 while (command_offset < size) { 740 741 // handle signaling commands 742 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 743 744 // increment command_offset 745 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 746 } 747 return; 748 } 749 750 // Find channel for this channel_id and connection handle 751 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 752 if (channel) { 753 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 754 } 755 } 756 757 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 758 switch (packet_type) { 759 case HCI_EVENT_PACKET: 760 l2cap_event_handler(packet, size); 761 break; 762 case HCI_ACL_DATA_PACKET: 763 l2cap_acl_handler(packet, size); 764 break; 765 default: 766 break; 767 } 768 } 769 770 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 771 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 772 channel->state = L2CAP_STATE_CLOSED; 773 l2cap_emit_channel_closed(channel); 774 // discard channel 775 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 776 free (channel); 777 } 778 779 l2cap_service_t * l2cap_get_service(uint16_t psm){ 780 linked_item_t *it; 781 782 // close open channels 783 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 784 l2cap_service_t * service = ((l2cap_service_t *) it); 785 if ( service->psm == psm){ 786 return service; 787 }; 788 } 789 return NULL; 790 } 791 792 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 793 // check for alread registered psm // TODO: emit error event 794 l2cap_service_t *service = l2cap_get_service(psm); 795 if (service) return; 796 797 // alloc structure // TODO: emit error event 798 service = malloc(sizeof(l2cap_service_t)); 799 if (!service) return; 800 801 // fill in 802 service->psm = psm; 803 service->mtu = mtu; 804 service->connection = connection; 805 service->packet_handler = packet_handler; 806 807 // add to services list 808 linked_list_add(&l2cap_services, (linked_item_t *) service); 809 } 810 811 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 812 l2cap_service_t *service = l2cap_get_service(psm); 813 if (!service) return; 814 linked_list_remove(&l2cap_services, (linked_item_t *) service); 815 free(service); 816 } 817 818 // 819 void l2cap_close_connection(void *connection){ 820 linked_item_t *it; 821 822 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 823 l2cap_channel_t * channel; 824 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 825 channel = (l2cap_channel_t *) it; 826 if (channel->connection == connection) { 827 channel->sig_id = l2cap_next_sig_id(); 828 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 829 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 830 } 831 } 832 833 // unregister services 834 it = (linked_item_t *) &l2cap_services; 835 while (it->next) { 836 l2cap_service_t * service = (l2cap_service_t *) it->next; 837 if (service->connection == connection){ 838 it->next = it->next->next; 839 free(service); 840 } else { 841 it = it->next; 842 } 843 } 844 } 845