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_RESPONSE_DECLINE: 256 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, 0, 0, channel->reason, 0); 257 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 258 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 259 free (channel); 260 break; 261 262 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 263 // success, start l2cap handshake 264 channel->sig_id = l2cap_next_sig_id(); 265 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->sig_id, channel->psm, channel->local_cid); 266 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 267 break; 268 269 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 270 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->sig_id, channel->local_cid, channel->remote_cid); 271 l2cap_finialize_channel_close(channel); 272 break; 273 274 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 275 channel->sig_id = l2cap_next_sig_id(); 276 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 277 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 278 break; 279 default: 280 break; 281 } 282 } 283 } 284 285 // open outgoing L2CAP channel 286 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 287 bd_addr_t address, uint16_t psm, uint16_t mtu){ 288 289 // alloc structure 290 l2cap_channel_t * chan = malloc(sizeof(l2cap_channel_t)); 291 // TODO: emit error event 292 if (!chan) return; 293 294 // limit local mtu to max acl packet length 295 if (mtu > hci_max_acl_data_packet_length()) { 296 mtu = hci_max_acl_data_packet_length(); 297 } 298 299 // fill in 300 BD_ADDR_COPY(chan->address, address); 301 chan->psm = psm; 302 chan->handle = 0; 303 chan->connection = connection; 304 chan->packet_handler = packet_handler; 305 chan->remote_mtu = L2CAP_MINIMAL_MTU; 306 chan->local_mtu = mtu; 307 chan->packets_granted = 0; 308 309 // set initial state 310 chan->state = L2CAP_STATE_CLOSED; 311 chan->sig_id = L2CAP_SIG_ID_INVALID; 312 313 // add to connections list 314 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 315 316 // send connection request 317 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 318 hci_send_cmd(&hci_create_connection, address, 0xcc18, 0, 0, 0, 1); 319 } 320 321 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 322 // find channel for local_cid 323 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 324 if (channel) { 325 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 326 } 327 // process 328 l2cap_run(); 329 } 330 331 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 332 linked_item_t *it = (linked_item_t *) &l2cap_channels; 333 while (it->next){ 334 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 335 if ( ! BD_ADDR_CMP( channel->address, address) ){ 336 if (channel->state == L2CAP_STATE_CLOSED) { 337 // failure, forward error code 338 l2cap_emit_channel_opened(channel, status); 339 // discard channel 340 it->next = it->next->next; 341 free (channel); 342 } 343 } else { 344 it = it->next; 345 } 346 } 347 } 348 349 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 350 linked_item_t *it; 351 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 352 l2cap_channel_t * channel = (l2cap_channel_t *) it; 353 if ( ! BD_ADDR_CMP( channel->address, address) ){ 354 if (channel->state == L2CAP_STATE_CLOSED) { 355 // success, start l2cap handshake 356 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 357 channel->handle = handle; 358 channel->local_cid = l2cap_next_local_cid(); 359 } 360 } 361 } 362 // process 363 l2cap_run(); 364 } 365 366 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 367 368 bd_addr_t address; 369 hci_con_handle_t handle; 370 linked_item_t *it; 371 372 switch(packet[0]){ 373 374 // handle connection complete events 375 case HCI_EVENT_CONNECTION_COMPLETE: 376 bt_flip_addr(address, &packet[5]); 377 if (packet[2] == 0){ 378 handle = READ_BT_16(packet, 3); 379 l2cap_handle_connection_success_for_addr(address, handle); 380 } else { 381 l2cap_handle_connection_failed_for_addr(address, packet[2]); 382 } 383 break; 384 385 // handle successful create connection cancel command 386 case HCI_EVENT_COMMAND_COMPLETE: 387 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 388 if (packet[5] == 0){ 389 bt_flip_addr(address, &packet[6]); 390 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 391 l2cap_handle_connection_failed_for_addr(address, 0x16); 392 } 393 } 394 break; 395 396 // handle disconnection complete events 397 case HCI_EVENT_DISCONNECTION_COMPLETE: 398 // send l2cap disconnect events for all channels on this handle 399 handle = READ_BT_16(packet, 3); 400 it = (linked_item_t *) &l2cap_channels; 401 while (it->next){ 402 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 403 if ( channel->handle == handle ){ 404 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 405 it->next = it->next->next; 406 l2cap_emit_channel_closed(channel); 407 free (channel); 408 } else { 409 it = it->next; 410 } 411 } 412 break; 413 414 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 415 l2cap_hand_out_credits(); 416 break; 417 418 // HCI Connection Timeouts 419 case L2CAP_EVENT_TIMEOUT_CHECK: 420 handle = READ_BT_16(packet, 2); 421 if (hci_authentication_active_for_handle(handle)) break; 422 l2cap_channel_t * channel; 423 int used = 0; 424 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 425 channel = (l2cap_channel_t *) it; 426 if (channel->handle == handle) { 427 used = 1; 428 } 429 } 430 if (!used) { 431 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 432 } 433 break; 434 435 default: 436 break; 437 } 438 439 // pass on 440 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 441 } 442 443 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 444 channel->sig_id = identifier; 445 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 446 l2cap_run(); 447 } 448 449 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 450 451 // log_dbg("l2cap_handle_connection_request for handle %u, psm %u cid %u\n", handle, psm, source_cid); 452 l2cap_service_t *service = l2cap_get_service(psm); 453 if (!service) { 454 // 0x0002 PSM not supported 455 // log_dbg("l2cap_handle_connection_request no PSM for psm %u/n", psm); 456 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, 0x0002, 0); 457 return; 458 } 459 460 hci_connection_t * hci_connection = connection_for_handle( handle ); 461 if (!hci_connection) { 462 log_err("no hci_connection for handle %u\n", handle); 463 // TODO: emit error 464 return; 465 } 466 // alloc structure 467 // log_dbg("l2cap_handle_connection_request register channel\n"); 468 l2cap_channel_t * channel = malloc(sizeof(l2cap_channel_t)); 469 // TODO: emit error event 470 if (!channel) return; 471 472 // fill in 473 BD_ADDR_COPY(channel->address, hci_connection->address); 474 channel->psm = psm; 475 channel->handle = handle; 476 channel->connection = service->connection; 477 channel->packet_handler = service->packet_handler; 478 channel->local_cid = l2cap_next_local_cid(); 479 channel->remote_cid = source_cid; 480 channel->local_mtu = service->mtu; 481 channel->remote_mtu = L2CAP_DEFAULT_MTU; 482 channel->packets_granted = 0; 483 484 // limit local mtu to max acl packet length 485 if (channel->local_mtu > hci_max_acl_data_packet_length()) { 486 channel->local_mtu = hci_max_acl_data_packet_length(); 487 } 488 489 // set initial state 490 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 491 492 // temp. store req sig id 493 channel->sig_id = sig_id; 494 495 // add to connections list 496 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 497 498 // emit incoming connection request 499 l2cap_emit_connection_request(channel); 500 } 501 502 void l2cap_accept_connection_internal(uint16_t local_cid){ 503 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 504 if (!channel) { 505 log_err("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 506 return; 507 } 508 509 // accept connection 510 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, channel->local_cid, channel->remote_cid, 0, 0); 511 512 // set real sig and state and start config 513 channel->sig_id = l2cap_next_sig_id(); 514 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 515 uint8_t config_options[4]; 516 config_options[0] = 1; // MTU 517 config_options[1] = 2; // len param 518 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 519 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 520 521 // log_dbg("new state %u\n", channel->state); 522 } 523 524 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 525 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 526 if (!channel) { 527 log_err( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 528 return; 529 } 530 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 531 channel->reason = reason; 532 l2cap_run(); 533 } 534 535 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 536 // accept the other's configuration options 537 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 538 uint16_t pos = 8; 539 while (pos < end_pos){ 540 uint8_t type = command[pos++]; 541 uint8_t length = command[pos++]; 542 // MTU { type(8): 1, len(8):2, MTU(16) } 543 if ((type & 0x7f) == 1 && length == 2){ 544 channel->remote_mtu = READ_BT_16(command, pos); 545 // log_dbg("l2cap cid %u, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 546 } 547 pos += length; 548 } 549 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 550 // send back OK 551 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->remote_cid, 0, 0, 0, NULL); 552 } 553 554 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 555 556 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 557 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 558 uint16_t result = 0; 559 uint8_t config_options[4]; 560 561 // log_dbg("signaling handler code %u\n", code); 562 563 switch (channel->state) { 564 565 case L2CAP_STATE_WAIT_CONNECT_RSP: 566 switch (code){ 567 case CONNECTION_RESPONSE: 568 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 569 switch (result) { 570 case 0: 571 // successful connection 572 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 573 574 575 channel->sig_id = l2cap_next_sig_id(); 576 config_options[0] = 1; // MTU 577 config_options[1] = 2; // len param 578 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 579 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 580 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 581 582 #if 0 583 channel->state = L2CAP_STATE_OPEN; 584 l2cap_emit_channel_opened(channel, 0); // success 585 l2cap_emit_credits(channel, 1); 586 #endif 587 break; 588 case 1: 589 // connection pending. get some coffee 590 break; 591 default: 592 // channel closed 593 channel->state = L2CAP_STATE_CLOSED; 594 595 // map l2cap connection response result to BTstack status enumeration 596 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 597 598 // drop link key if security block 599 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 600 hci_drop_link_key_for_bd_addr(&channel->address); 601 } 602 603 // discard channel 604 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 605 free (channel); 606 break; 607 } 608 break; 609 610 case DISCONNECTION_REQUEST: 611 l2cap_handle_disconnect_request(channel, identifier); 612 break; 613 614 default: 615 //@TODO: implement other signaling packets 616 break; 617 } 618 break; 619 620 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ: 621 switch (code) { 622 case CONFIGURE_RESPONSE: 623 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ; 624 break; 625 case CONFIGURE_REQUEST: 626 l2cap_signaling_handle_configure_request(channel, command); 627 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP; 628 break; 629 case DISCONNECTION_REQUEST: 630 l2cap_handle_disconnect_request(channel, identifier); 631 break; 632 default: 633 //@TODO: implement other signaling packets 634 break; 635 } 636 break; 637 638 case L2CAP_STATE_WAIT_CONFIG_REQ: 639 switch (code) { 640 case CONFIGURE_REQUEST: 641 l2cap_signaling_handle_configure_request(channel, command); 642 channel->state = L2CAP_STATE_OPEN; 643 l2cap_emit_channel_opened(channel, 0); // success 644 l2cap_emit_credits(channel, 1); 645 break; 646 case DISCONNECTION_REQUEST: 647 l2cap_handle_disconnect_request(channel, identifier); 648 break; 649 default: 650 //@TODO: implement other signaling packets 651 break; 652 } 653 break; 654 655 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP: 656 switch (code) { 657 case CONFIGURE_RESPONSE: 658 channel->state = L2CAP_STATE_OPEN; 659 l2cap_emit_channel_opened(channel, 0); // success 660 l2cap_emit_credits(channel, 1); 661 break; 662 case DISCONNECTION_REQUEST: 663 l2cap_handle_disconnect_request(channel, identifier); 664 break; 665 default: 666 //@TODO: implement other signaling packets 667 break; 668 } 669 break; 670 671 case L2CAP_STATE_WAIT_DISCONNECT: 672 switch (code) { 673 case DISCONNECTION_RESPONSE: 674 l2cap_finialize_channel_close(channel); 675 break; 676 case DISCONNECTION_REQUEST: 677 l2cap_handle_disconnect_request(channel, identifier); 678 break; 679 default: 680 //@TODO: implement other signaling packets 681 break; 682 } 683 break; 684 685 case L2CAP_STATE_CLOSED: 686 // @TODO handle incoming requests 687 break; 688 689 case L2CAP_STATE_OPEN: 690 switch (code) { 691 case DISCONNECTION_REQUEST: 692 l2cap_handle_disconnect_request(channel, identifier); 693 break; 694 default: 695 //@TODO: implement other signaling packets, e.g. re-configure 696 break; 697 } 698 break; 699 default: 700 break; 701 } 702 // log_dbg("new state %u\n", channel->state); 703 } 704 705 706 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 707 708 // get code, signalind identifier and command len 709 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 710 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 711 uint16_t len = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 712 713 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 714 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 715 return; 716 } 717 718 // general commands without an assigned channel 719 switch(code) { 720 721 case CONNECTION_REQUEST: { 722 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 723 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 724 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 725 break; 726 } 727 728 case ECHO_REQUEST: { 729 // send back packet 730 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, len, &command[L2CAP_SIGNALING_COMMAND_DATA_OFFSET]); 731 break; 732 } 733 734 case INFORMATION_REQUEST: { 735 // we neither support connectionless L2CAP data nor support any flow control modes yet 736 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 737 if (infoType == 2) { 738 uint32_t features = 0; 739 // extended features request supported, however no features present 740 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, 4, &features); 741 } else { 742 // all other types are not supported 743 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 744 } 745 break;; 746 } 747 748 default: 749 break; 750 } 751 752 753 // Get potential destination CID 754 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 755 756 // Find channel for this sig_id and connection handle 757 linked_item_t *it; 758 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 759 l2cap_channel_t * channel = (l2cap_channel_t *) it; 760 if (channel->handle == handle) { 761 if (code & 1) { 762 // match odd commands by previous signaling identifier 763 if (channel->sig_id == sig_id) { 764 l2cap_signaling_handler_channel(channel, command); 765 break; 766 } 767 } else { 768 // match even commands by local channel id 769 if (channel->local_cid == dest_cid) { 770 l2cap_signaling_handler_channel(channel, command); 771 break; 772 } 773 } 774 } 775 } 776 } 777 778 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 779 780 // Get Channel ID 781 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 782 783 // Signaling Packet? 784 if (channel_id == 1) { 785 786 // Get Connection 787 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 788 789 uint16_t command_offset = 8; 790 while (command_offset < size) { 791 792 // handle signaling commands 793 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 794 795 // increment command_offset 796 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 797 } 798 return; 799 } 800 801 // Find channel for this channel_id and connection handle 802 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 803 if (channel) { 804 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 805 } 806 } 807 808 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 809 switch (packet_type) { 810 case HCI_EVENT_PACKET: 811 l2cap_event_handler(packet, size); 812 break; 813 case HCI_ACL_DATA_PACKET: 814 l2cap_acl_handler(packet, size); 815 break; 816 default: 817 break; 818 } 819 } 820 821 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 822 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 823 channel->state = L2CAP_STATE_CLOSED; 824 l2cap_emit_channel_closed(channel); 825 // discard channel 826 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 827 free (channel); 828 } 829 830 l2cap_service_t * l2cap_get_service(uint16_t psm){ 831 linked_item_t *it; 832 833 // close open channels 834 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 835 l2cap_service_t * service = ((l2cap_service_t *) it); 836 if ( service->psm == psm){ 837 return service; 838 }; 839 } 840 return NULL; 841 } 842 843 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 844 // check for alread registered psm // TODO: emit error event 845 l2cap_service_t *service = l2cap_get_service(psm); 846 if (service) return; 847 848 // alloc structure // TODO: emit error event 849 service = malloc(sizeof(l2cap_service_t)); 850 if (!service) return; 851 852 // fill in 853 service->psm = psm; 854 service->mtu = mtu; 855 service->connection = connection; 856 service->packet_handler = packet_handler; 857 858 // add to services list 859 linked_list_add(&l2cap_services, (linked_item_t *) service); 860 } 861 862 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 863 l2cap_service_t *service = l2cap_get_service(psm); 864 if (!service) return; 865 linked_list_remove(&l2cap_services, (linked_item_t *) service); 866 free(service); 867 } 868 869 // 870 void l2cap_close_connection(void *connection){ 871 linked_item_t *it; 872 873 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 874 l2cap_channel_t * channel; 875 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 876 channel = (l2cap_channel_t *) it; 877 if (channel->connection == connection) { 878 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 879 } 880 } 881 882 // unregister services 883 it = (linked_item_t *) &l2cap_services; 884 while (it->next) { 885 l2cap_service_t * service = (l2cap_service_t *) it->next; 886 if (service->connection == connection){ 887 it->next = it->next->next; 888 free(service); 889 } else { 890 it = it->next; 891 } 892 } 893 894 // process 895 l2cap_run(); 896 } 897