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 static int new_credits_blocked = 0; 75 76 void l2cap_init(){ 77 sig_buffer = malloc( L2CAP_MINIMAL_MTU ); 78 acl_buffer = malloc( HCI_ACL_3DH5_SIZE); 79 80 new_credits_blocked = 0; 81 82 // 83 // register callback with HCI 84 // 85 hci_register_packet_handler(&l2cap_packet_handler); 86 } 87 88 89 /** Register L2CAP packet handlers */ 90 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 91 } 92 void l2cap_register_packet_handler(void (*handler)(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 93 packet_handler = handler; 94 } 95 96 // notify client/protocol handler 97 void l2cap_dispatch(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 98 if (channel->packet_handler) { 99 (* (channel->packet_handler))(type, channel->local_cid, data, size); 100 } else { 101 (*packet_handler)(channel->connection, type, channel->local_cid, data, size); 102 } 103 } 104 105 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 106 uint8_t event[21]; 107 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 108 event[1] = sizeof(event) - 2; 109 event[2] = status; 110 bt_flip_addr(&event[3], channel->address); 111 bt_store_16(event, 9, channel->handle); 112 bt_store_16(event, 11, channel->psm); 113 bt_store_16(event, 13, channel->local_cid); 114 bt_store_16(event, 15, channel->remote_cid); 115 bt_store_16(event, 17, channel->local_mtu); 116 bt_store_16(event, 19, channel->remote_mtu); 117 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 118 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 119 } 120 121 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 122 uint8_t event[4]; 123 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 124 event[1] = sizeof(event) - 2; 125 bt_store_16(event, 2, channel->local_cid); 126 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 127 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 128 } 129 130 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 131 uint8_t event[16]; 132 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 133 event[1] = sizeof(event) - 2; 134 bt_flip_addr(&event[2], channel->address); 135 bt_store_16(event, 8, channel->handle); 136 bt_store_16(event, 10, channel->psm); 137 bt_store_16(event, 12, channel->local_cid); 138 bt_store_16(event, 14, channel->remote_cid); 139 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 140 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 141 } 142 143 void l2cap_emit_credits(l2cap_channel_t *channel, uint8_t credits) { 144 // track credits 145 channel->packets_granted += credits; 146 // log_dbg("l2cap_emit_credits for cid %u, credits given: %u (+%u)\n", channel->local_cid, channel->packets_granted, credits); 147 148 uint8_t event[5]; 149 event[0] = L2CAP_EVENT_CREDITS; 150 event[1] = sizeof(event) - 2; 151 bt_store_16(event, 2, channel->local_cid); 152 event[4] = credits; 153 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 154 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 155 } 156 157 void l2cap_block_new_credits(uint8_t blocked){ 158 new_credits_blocked = blocked; 159 } 160 161 void l2cap_hand_out_credits(void){ 162 163 if (new_credits_blocked) return; // we're told not to. used by daemon 164 165 linked_item_t *it; 166 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 167 if (!hci_number_free_acl_slots()) return; 168 l2cap_channel_t * channel = (l2cap_channel_t *) it; 169 if (channel->state != L2CAP_STATE_OPEN) continue; 170 if (hci_number_outgoing_packets(channel->handle) < NR_BUFFERED_ACL_PACKETS && channel->packets_granted == 0) { 171 l2cap_emit_credits(channel, 1); 172 } 173 } 174 } 175 176 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 177 linked_item_t *it; 178 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 179 l2cap_channel_t * channel = (l2cap_channel_t *) it; 180 if ( channel->local_cid == local_cid) { 181 return channel; 182 } 183 } 184 return NULL; 185 } 186 187 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 188 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 189 if (channel) { 190 return channel->remote_mtu; 191 } 192 return 0; 193 } 194 195 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 196 // log_dbg("l2cap_send_signaling_packet type %u\n", cmd); 197 va_list argptr; 198 va_start(argptr, identifier); 199 uint16_t len = l2cap_create_signaling_internal(sig_buffer, handle, cmd, identifier, argptr); 200 va_end(argptr); 201 // log_dbg("l2cap_send_signaling_packet con %u!\n", handle); 202 return hci_send_acl_packet(sig_buffer, len); 203 } 204 205 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 206 207 // check for free places on BT module 208 if (!hci_number_free_acl_slots()) { 209 log_dbg("l2cap_send_internal cid %u, BT module full <-----\n", local_cid); 210 return BTSTACK_ACL_BUFFERS_FULL; 211 } 212 int err = 0; 213 214 // find channel for local_cid, construct l2cap packet and send 215 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 216 if (channel) { 217 if (channel->packets_granted > 0){ 218 --channel->packets_granted; 219 // log_dbg("l2cap_send_internal cid %u, handle %u, 1 credit used, credits left %u;\n", 220 // local_cid, channel->handle, channel->packets_granted); 221 } else { 222 log_err("l2cap_send_internal cid %u, no credits!\n", local_cid); 223 } 224 225 // 0 - Connection handle : PB=10 : BC=00 226 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 227 // 2 - ACL length 228 bt_store_16(acl_buffer, 2, len + 4); 229 // 4 - L2CAP packet length 230 bt_store_16(acl_buffer, 4, len + 0); 231 // 6 - L2CAP channel DEST 232 bt_store_16(acl_buffer, 6, channel->remote_cid); 233 // 8 - data 234 memcpy(&acl_buffer[8], data, len); 235 236 // send 237 err = hci_send_acl_packet(acl_buffer, len+8); 238 } 239 240 l2cap_hand_out_credits(); 241 242 return err; 243 } 244 245 // process outstanding signaling tasks 246 void l2cap_run(void){ 247 linked_item_t *it; 248 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 249 250 // can send? 251 252 l2cap_channel_t * channel = (l2cap_channel_t *) it; 253 switch (channel->state){ 254 255 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 256 // success, start l2cap handshake 257 channel->sig_id = l2cap_next_sig_id(); 258 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->sig_id, channel->psm, channel->local_cid); 259 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 260 break; 261 262 case L2CAP_STATE_WILL_SEND_DISCONNECT: 263 channel->sig_id = l2cap_next_sig_id(); 264 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 265 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 266 break; 267 default: 268 break; 269 } 270 } 271 } 272 273 // open outgoing L2CAP channel 274 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 275 bd_addr_t address, uint16_t psm, uint16_t mtu){ 276 277 // alloc structure 278 l2cap_channel_t * chan = malloc(sizeof(l2cap_channel_t)); 279 // TODO: emit error event 280 if (!chan) return; 281 282 // limit local mtu to max acl packet length 283 if (mtu > hci_max_acl_data_packet_length()) { 284 mtu = hci_max_acl_data_packet_length(); 285 } 286 287 // fill in 288 BD_ADDR_COPY(chan->address, address); 289 chan->psm = psm; 290 chan->handle = 0; 291 chan->connection = connection; 292 chan->packet_handler = packet_handler; 293 chan->remote_mtu = L2CAP_MINIMAL_MTU; 294 chan->local_mtu = mtu; 295 chan->packets_granted = 0; 296 297 // set initial state 298 chan->state = L2CAP_STATE_CLOSED; 299 chan->sig_id = L2CAP_SIG_ID_INVALID; 300 301 // add to connections list 302 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 303 304 // send connection request 305 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 306 hci_send_cmd(&hci_create_connection, address, 0xcc18, 0, 0, 0, 1); 307 } 308 309 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 310 // find channel for local_cid 311 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 312 if (channel) { 313 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT; 314 } 315 // process 316 l2cap_run(); 317 } 318 319 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 320 linked_item_t *it = (linked_item_t *) &l2cap_channels; 321 while (it->next){ 322 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 323 if ( ! BD_ADDR_CMP( channel->address, address) ){ 324 if (channel->state == L2CAP_STATE_CLOSED) { 325 // failure, forward error code 326 l2cap_emit_channel_opened(channel, status); 327 // discard channel 328 it->next = it->next->next; 329 free (channel); 330 } 331 } else { 332 it = it->next; 333 } 334 } 335 } 336 337 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 338 linked_item_t *it; 339 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 340 l2cap_channel_t * channel = (l2cap_channel_t *) it; 341 if ( ! BD_ADDR_CMP( channel->address, address) ){ 342 if (channel->state == L2CAP_STATE_CLOSED) { 343 // success, start l2cap handshake 344 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 345 channel->handle = handle; 346 channel->local_cid = l2cap_next_local_cid(); 347 } 348 } 349 } 350 // process 351 l2cap_run(); 352 } 353 354 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 355 356 bd_addr_t address; 357 hci_con_handle_t handle; 358 linked_item_t *it; 359 360 switch(packet[0]){ 361 362 // handle connection complete events 363 case HCI_EVENT_CONNECTION_COMPLETE: 364 bt_flip_addr(address, &packet[5]); 365 if (packet[2] == 0){ 366 handle = READ_BT_16(packet, 3); 367 l2cap_handle_connection_success_for_addr(address, handle); 368 } else { 369 l2cap_handle_connection_failed_for_addr(address, packet[2]); 370 } 371 break; 372 373 // handle successful create connection cancel command 374 case HCI_EVENT_COMMAND_COMPLETE: 375 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 376 if (packet[5] == 0){ 377 bt_flip_addr(address, &packet[6]); 378 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 379 l2cap_handle_connection_failed_for_addr(address, 0x16); 380 } 381 } 382 break; 383 384 // handle disconnection complete events 385 case HCI_EVENT_DISCONNECTION_COMPLETE: 386 // send l2cap disconnect events for all channels on this handle 387 handle = READ_BT_16(packet, 3); 388 it = (linked_item_t *) &l2cap_channels; 389 while (it->next){ 390 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 391 if ( channel->handle == handle ){ 392 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 393 it->next = it->next->next; 394 l2cap_emit_channel_closed(channel); 395 free (channel); 396 } else { 397 it = it->next; 398 } 399 } 400 break; 401 402 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 403 l2cap_hand_out_credits(); 404 break; 405 406 // HCI Connection Timeouts 407 case L2CAP_EVENT_TIMEOUT_CHECK: 408 handle = READ_BT_16(packet, 2); 409 if (hci_authentication_active_for_handle(handle)) break; 410 l2cap_channel_t * channel; 411 int used = 0; 412 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 413 channel = (l2cap_channel_t *) it; 414 if (channel->handle == handle) { 415 used = 1; 416 } 417 } 418 if (!used) { 419 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 420 } 421 break; 422 423 default: 424 break; 425 } 426 427 // pass on 428 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 429 } 430 431 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 432 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, identifier, channel->local_cid, channel->remote_cid); 433 l2cap_finialize_channel_close(channel); 434 } 435 436 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 437 438 // log_dbg("l2cap_handle_connection_request for handle %u, psm %u cid %u\n", handle, psm, source_cid); 439 l2cap_service_t *service = l2cap_get_service(psm); 440 if (!service) { 441 // 0x0002 PSM not supported 442 // log_dbg("l2cap_handle_connection_request no PSM for psm %u/n", psm); 443 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, 0x0002, 0); 444 return; 445 } 446 447 hci_connection_t * hci_connection = connection_for_handle( handle ); 448 if (!hci_connection) { 449 log_err("no hci_connection for handle %u\n", handle); 450 // TODO: emit error 451 return; 452 } 453 // alloc structure 454 // log_dbg("l2cap_handle_connection_request register channel\n"); 455 l2cap_channel_t * channel = malloc(sizeof(l2cap_channel_t)); 456 // TODO: emit error event 457 if (!channel) return; 458 459 // fill in 460 BD_ADDR_COPY(channel->address, hci_connection->address); 461 channel->psm = psm; 462 channel->handle = handle; 463 channel->connection = service->connection; 464 channel->packet_handler = service->packet_handler; 465 channel->local_cid = l2cap_next_local_cid(); 466 channel->remote_cid = source_cid; 467 channel->local_mtu = service->mtu; 468 channel->remote_mtu = L2CAP_DEFAULT_MTU; 469 channel->packets_granted = 0; 470 471 // limit local mtu to max acl packet length 472 if (channel->local_mtu > hci_max_acl_data_packet_length()) { 473 channel->local_mtu = hci_max_acl_data_packet_length(); 474 } 475 476 // set initial state 477 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 478 479 // temp. store req sig id 480 channel->sig_id = sig_id; 481 482 // add to connections list 483 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 484 485 // emit incoming connection request 486 l2cap_emit_connection_request(channel); 487 } 488 489 void l2cap_accept_connection_internal(uint16_t local_cid){ 490 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 491 if (!channel) { 492 log_err("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 493 return; 494 } 495 496 // accept connection 497 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, channel->local_cid, channel->remote_cid, 0, 0); 498 499 // set real sig and state and start config 500 channel->sig_id = l2cap_next_sig_id(); 501 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 502 uint8_t config_options[4]; 503 config_options[0] = 1; // MTU 504 config_options[1] = 2; // len param 505 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 506 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 507 508 // log_dbg("new state %u\n", channel->state); 509 } 510 511 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 512 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 513 if (!channel) { 514 log_err( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 515 return; 516 } 517 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, 0, 0, reason, 0); 518 519 // discard channel 520 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 521 free (channel); 522 } 523 524 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 525 // accept the other's configuration options 526 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 527 uint16_t pos = 8; 528 while (pos < end_pos){ 529 uint8_t type = command[pos++]; 530 uint8_t length = command[pos++]; 531 // MTU { type(8): 1, len(8):2, MTU(16) } 532 if ((type & 0x7f) == 1 && length == 2){ 533 channel->remote_mtu = READ_BT_16(command, pos); 534 // log_dbg("l2cap cid %u, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 535 } 536 pos += length; 537 } 538 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 539 // send back OK 540 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->remote_cid, 0, 0, 0, NULL); 541 } 542 543 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 544 545 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 546 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 547 uint16_t result = 0; 548 uint8_t config_options[4]; 549 550 // log_dbg("signaling handler code %u\n", code); 551 552 switch (channel->state) { 553 554 case L2CAP_STATE_WAIT_CONNECT_RSP: 555 switch (code){ 556 case CONNECTION_RESPONSE: 557 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 558 switch (result) { 559 case 0: 560 // successful connection 561 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 562 channel->sig_id = l2cap_next_sig_id(); 563 config_options[0] = 1; // MTU 564 config_options[1] = 2; // len param 565 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 566 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 567 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 568 569 #if 0 570 channel->state = L2CAP_STATE_OPEN; 571 l2cap_emit_channel_opened(channel, 0); // success 572 l2cap_emit_credits(channel, 1); 573 #endif 574 break; 575 case 1: 576 // connection pending. get some coffee 577 break; 578 default: 579 // channel closed 580 channel->state = L2CAP_STATE_CLOSED; 581 582 // map l2cap connection response result to BTstack status enumeration 583 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 584 585 // drop link key if security block 586 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 587 hci_drop_link_key_for_bd_addr(&channel->address); 588 } 589 590 // discard channel 591 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 592 free (channel); 593 break; 594 } 595 break; 596 597 case DISCONNECTION_REQUEST: 598 l2cap_handle_disconnect_request(channel, identifier); 599 break; 600 601 default: 602 //@TODO: implement other signaling packets 603 break; 604 } 605 break; 606 607 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ: 608 switch (code) { 609 case CONFIGURE_RESPONSE: 610 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ; 611 break; 612 case CONFIGURE_REQUEST: 613 l2cap_signaling_handle_configure_request(channel, command); 614 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP; 615 break; 616 case DISCONNECTION_REQUEST: 617 l2cap_handle_disconnect_request(channel, identifier); 618 break; 619 default: 620 //@TODO: implement other signaling packets 621 break; 622 } 623 break; 624 625 case L2CAP_STATE_WAIT_CONFIG_REQ: 626 switch (code) { 627 case CONFIGURE_REQUEST: 628 l2cap_signaling_handle_configure_request(channel, command); 629 channel->state = L2CAP_STATE_OPEN; 630 l2cap_emit_channel_opened(channel, 0); // success 631 l2cap_emit_credits(channel, 1); 632 break; 633 case DISCONNECTION_REQUEST: 634 l2cap_handle_disconnect_request(channel, identifier); 635 break; 636 default: 637 //@TODO: implement other signaling packets 638 break; 639 } 640 break; 641 642 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP: 643 switch (code) { 644 case CONFIGURE_RESPONSE: 645 channel->state = L2CAP_STATE_OPEN; 646 l2cap_emit_channel_opened(channel, 0); // success 647 l2cap_emit_credits(channel, 1); 648 break; 649 case DISCONNECTION_REQUEST: 650 l2cap_handle_disconnect_request(channel, identifier); 651 break; 652 default: 653 //@TODO: implement other signaling packets 654 break; 655 } 656 break; 657 658 case L2CAP_STATE_WAIT_DISCONNECT: 659 switch (code) { 660 case DISCONNECTION_RESPONSE: 661 l2cap_finialize_channel_close(channel); 662 break; 663 case DISCONNECTION_REQUEST: 664 l2cap_handle_disconnect_request(channel, identifier); 665 break; 666 default: 667 //@TODO: implement other signaling packets 668 break; 669 } 670 break; 671 672 case L2CAP_STATE_CLOSED: 673 // @TODO handle incoming requests 674 break; 675 676 case L2CAP_STATE_OPEN: 677 switch (code) { 678 case DISCONNECTION_REQUEST: 679 l2cap_handle_disconnect_request(channel, identifier); 680 break; 681 default: 682 //@TODO: implement other signaling packets, e.g. re-configure 683 break; 684 } 685 break; 686 default: 687 break; 688 } 689 // log_dbg("new state %u\n", channel->state); 690 } 691 692 693 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 694 695 // get code, signalind identifier and command len 696 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 697 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 698 uint16_t len = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 699 700 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 701 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 702 return; 703 } 704 705 // general commands without an assigned channel 706 switch(code) { 707 708 case CONNECTION_REQUEST: { 709 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 710 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 711 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 712 break; 713 } 714 715 case ECHO_REQUEST: { 716 // send back packet 717 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, len, &command[L2CAP_SIGNALING_COMMAND_DATA_OFFSET]); 718 break; 719 } 720 721 case INFORMATION_REQUEST: { 722 // we neither support connectionless L2CAP data nor support any flow control modes yet 723 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 724 if (infoType == 2) { 725 uint32_t features = 0; 726 // extended features request supported, however no features present 727 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, 4, &features); 728 } else { 729 // all other types are not supported 730 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 731 } 732 break;; 733 } 734 735 default: 736 break; 737 } 738 739 740 // Get potential destination CID 741 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 742 743 // Find channel for this sig_id and connection handle 744 linked_item_t *it; 745 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 746 l2cap_channel_t * channel = (l2cap_channel_t *) it; 747 if (channel->handle == handle) { 748 if (code & 1) { 749 // match odd commands by previous signaling identifier 750 if (channel->sig_id == sig_id) { 751 l2cap_signaling_handler_channel(channel, command); 752 break; 753 } 754 } else { 755 // match even commands by local channel id 756 if (channel->local_cid == dest_cid) { 757 l2cap_signaling_handler_channel(channel, command); 758 break; 759 } 760 } 761 } 762 } 763 } 764 765 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 766 767 // Get Channel ID 768 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 769 770 // Signaling Packet? 771 if (channel_id == 1) { 772 773 // Get Connection 774 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 775 776 uint16_t command_offset = 8; 777 while (command_offset < size) { 778 779 // handle signaling commands 780 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 781 782 // increment command_offset 783 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 784 } 785 return; 786 } 787 788 // Find channel for this channel_id and connection handle 789 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 790 if (channel) { 791 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 792 } 793 } 794 795 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 796 switch (packet_type) { 797 case HCI_EVENT_PACKET: 798 l2cap_event_handler(packet, size); 799 break; 800 case HCI_ACL_DATA_PACKET: 801 l2cap_acl_handler(packet, size); 802 break; 803 default: 804 break; 805 } 806 } 807 808 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 809 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 810 channel->state = L2CAP_STATE_CLOSED; 811 l2cap_emit_channel_closed(channel); 812 // discard channel 813 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 814 free (channel); 815 } 816 817 l2cap_service_t * l2cap_get_service(uint16_t psm){ 818 linked_item_t *it; 819 820 // close open channels 821 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 822 l2cap_service_t * service = ((l2cap_service_t *) it); 823 if ( service->psm == psm){ 824 return service; 825 }; 826 } 827 return NULL; 828 } 829 830 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 831 // check for alread registered psm // TODO: emit error event 832 l2cap_service_t *service = l2cap_get_service(psm); 833 if (service) return; 834 835 // alloc structure // TODO: emit error event 836 service = malloc(sizeof(l2cap_service_t)); 837 if (!service) return; 838 839 // fill in 840 service->psm = psm; 841 service->mtu = mtu; 842 service->connection = connection; 843 service->packet_handler = packet_handler; 844 845 // add to services list 846 linked_list_add(&l2cap_services, (linked_item_t *) service); 847 } 848 849 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 850 l2cap_service_t *service = l2cap_get_service(psm); 851 if (!service) return; 852 linked_list_remove(&l2cap_services, (linked_item_t *) service); 853 free(service); 854 } 855 856 // 857 void l2cap_close_connection(void *connection){ 858 linked_item_t *it; 859 860 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 861 l2cap_channel_t * channel; 862 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 863 channel = (l2cap_channel_t *) it; 864 if (channel->connection == connection) { 865 channel->sig_id = l2cap_next_sig_id(); 866 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 867 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 868 } 869 } 870 871 // unregister services 872 it = (linked_item_t *) &l2cap_services; 873 while (it->next) { 874 l2cap_service_t * service = (l2cap_service_t *) it->next; 875 if (service->connection == connection){ 876 it->next = it->next->next; 877 free(service); 878 } else { 879 it = it->next; 880 } 881 } 882 } 883