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 uint8_t config_options[4]; 248 linked_item_t *it; 249 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 250 251 // can send? 252 253 l2cap_channel_t * channel = (l2cap_channel_t *) it; 254 switch (channel->state){ 255 256 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 257 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, 0, 0, channel->reason, 0); 258 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 259 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 260 free (channel); 261 break; 262 263 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 264 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, channel->local_cid, channel->remote_cid, 0, 0); 265 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_OR_SEND_CONFIG_REQ; 266 break; 267 268 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 269 // success, start l2cap handshake 270 channel->sig_id = l2cap_next_sig_id(); 271 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->sig_id, channel->psm, channel->local_cid); 272 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 273 break; 274 275 case L2CAP_STATE_WAIT_CONFIG_REQ_OR_SEND_CONFIG_REQ: 276 // after connection response was received 277 channel->sig_id = l2cap_next_sig_id(); 278 config_options[0] = 1; // MTU 279 config_options[1] = 2; // len param 280 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 281 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 282 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 283 break; 284 285 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_WILL_SEND_CONFIG_REQ_RSP: 286 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->sig_id, channel->remote_cid, 0, 0, 0, NULL); 287 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP; 288 break; 289 290 case L2CAP_STATE_WILL_SEND_CONFIG_REQ_RSP: 291 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->sig_id, channel->remote_cid, 0, 0, 0, NULL); 292 channel->state = L2CAP_STATE_OPEN; 293 l2cap_emit_channel_opened(channel, 0); // success 294 l2cap_emit_credits(channel, 1); 295 break; 296 297 case L2CAP_STATE_WILL_SEND_CONFIG_REQ_AND_CONFIG_REQ_RSP: 298 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->sig_id, channel->remote_cid, 0, 0, 0, NULL); 299 channel->state = L2CAP_STATE_WILL_SEND_CONFIG_REQ; 300 break; 301 302 case L2CAP_STATE_WILL_SEND_CONFIG_REQ: 303 channel->sig_id = l2cap_next_sig_id(); 304 config_options[0] = 1; // MTU 305 config_options[1] = 2; // len param 306 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 307 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 308 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP; 309 break; 310 311 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 312 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->sig_id, channel->local_cid, channel->remote_cid); 313 l2cap_finialize_channel_close(channel); 314 break; 315 316 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 317 channel->sig_id = l2cap_next_sig_id(); 318 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 319 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 320 break; 321 default: 322 break; 323 } 324 } 325 } 326 327 // open outgoing L2CAP channel 328 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 329 bd_addr_t address, uint16_t psm, uint16_t mtu){ 330 331 // alloc structure 332 l2cap_channel_t * chan = malloc(sizeof(l2cap_channel_t)); 333 // TODO: emit error event 334 if (!chan) return; 335 336 // limit local mtu to max acl packet length 337 if (mtu > hci_max_acl_data_packet_length()) { 338 mtu = hci_max_acl_data_packet_length(); 339 } 340 341 // fill in 342 BD_ADDR_COPY(chan->address, address); 343 chan->psm = psm; 344 chan->handle = 0; 345 chan->connection = connection; 346 chan->packet_handler = packet_handler; 347 chan->remote_mtu = L2CAP_MINIMAL_MTU; 348 chan->local_mtu = mtu; 349 chan->packets_granted = 0; 350 351 // set initial state 352 chan->state = L2CAP_STATE_CLOSED; 353 chan->sig_id = L2CAP_SIG_ID_INVALID; 354 355 // add to connections list 356 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 357 358 // send connection request 359 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 360 hci_send_cmd(&hci_create_connection, address, 0xcc18, 0, 0, 0, 1); 361 } 362 363 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 364 // find channel for local_cid 365 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 366 if (channel) { 367 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 368 } 369 // process 370 l2cap_run(); 371 } 372 373 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 374 linked_item_t *it = (linked_item_t *) &l2cap_channels; 375 while (it->next){ 376 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 377 if ( ! BD_ADDR_CMP( channel->address, address) ){ 378 if (channel->state == L2CAP_STATE_CLOSED) { 379 // failure, forward error code 380 l2cap_emit_channel_opened(channel, status); 381 // discard channel 382 it->next = it->next->next; 383 free (channel); 384 } 385 } else { 386 it = it->next; 387 } 388 } 389 } 390 391 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 392 linked_item_t *it; 393 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 394 l2cap_channel_t * channel = (l2cap_channel_t *) it; 395 if ( ! BD_ADDR_CMP( channel->address, address) ){ 396 if (channel->state == L2CAP_STATE_CLOSED) { 397 // success, start l2cap handshake 398 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 399 channel->handle = handle; 400 channel->local_cid = l2cap_next_local_cid(); 401 } 402 } 403 } 404 // process 405 l2cap_run(); 406 } 407 408 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 409 410 bd_addr_t address; 411 hci_con_handle_t handle; 412 linked_item_t *it; 413 414 switch(packet[0]){ 415 416 // handle connection complete events 417 case HCI_EVENT_CONNECTION_COMPLETE: 418 bt_flip_addr(address, &packet[5]); 419 if (packet[2] == 0){ 420 handle = READ_BT_16(packet, 3); 421 l2cap_handle_connection_success_for_addr(address, handle); 422 } else { 423 l2cap_handle_connection_failed_for_addr(address, packet[2]); 424 } 425 break; 426 427 // handle successful create connection cancel command 428 case HCI_EVENT_COMMAND_COMPLETE: 429 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 430 if (packet[5] == 0){ 431 bt_flip_addr(address, &packet[6]); 432 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 433 l2cap_handle_connection_failed_for_addr(address, 0x16); 434 } 435 } 436 break; 437 438 // handle disconnection complete events 439 case HCI_EVENT_DISCONNECTION_COMPLETE: 440 // send l2cap disconnect events for all channels on this handle 441 handle = READ_BT_16(packet, 3); 442 it = (linked_item_t *) &l2cap_channels; 443 while (it->next){ 444 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 445 if ( channel->handle == handle ){ 446 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 447 it->next = it->next->next; 448 l2cap_emit_channel_closed(channel); 449 free (channel); 450 } else { 451 it = it->next; 452 } 453 } 454 break; 455 456 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 457 l2cap_hand_out_credits(); 458 break; 459 460 // HCI Connection Timeouts 461 case L2CAP_EVENT_TIMEOUT_CHECK: 462 handle = READ_BT_16(packet, 2); 463 if (hci_authentication_active_for_handle(handle)) break; 464 l2cap_channel_t * channel; 465 int used = 0; 466 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 467 channel = (l2cap_channel_t *) it; 468 if (channel->handle == handle) { 469 used = 1; 470 } 471 } 472 if (!used) { 473 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 474 } 475 break; 476 477 default: 478 break; 479 } 480 481 // pass on 482 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 483 } 484 485 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 486 channel->sig_id = identifier; 487 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 488 l2cap_run(); 489 } 490 491 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 492 493 // log_dbg("l2cap_handle_connection_request for handle %u, psm %u cid %u\n", handle, psm, source_cid); 494 l2cap_service_t *service = l2cap_get_service(psm); 495 if (!service) { 496 // 0x0002 PSM not supported 497 // log_dbg("l2cap_handle_connection_request no PSM for psm %u/n", psm); 498 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, 0x0002, 0); 499 return; 500 } 501 502 hci_connection_t * hci_connection = connection_for_handle( handle ); 503 if (!hci_connection) { 504 log_err("no hci_connection for handle %u\n", handle); 505 // TODO: emit error 506 return; 507 } 508 // alloc structure 509 // log_dbg("l2cap_handle_connection_request register channel\n"); 510 l2cap_channel_t * channel = malloc(sizeof(l2cap_channel_t)); 511 // TODO: emit error event 512 if (!channel) return; 513 514 // fill in 515 BD_ADDR_COPY(channel->address, hci_connection->address); 516 channel->psm = psm; 517 channel->handle = handle; 518 channel->connection = service->connection; 519 channel->packet_handler = service->packet_handler; 520 channel->local_cid = l2cap_next_local_cid(); 521 channel->remote_cid = source_cid; 522 channel->local_mtu = service->mtu; 523 channel->remote_mtu = L2CAP_DEFAULT_MTU; 524 channel->packets_granted = 0; 525 526 // limit local mtu to max acl packet length 527 if (channel->local_mtu > hci_max_acl_data_packet_length()) { 528 channel->local_mtu = hci_max_acl_data_packet_length(); 529 } 530 531 // set initial state 532 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 533 534 // temp. store req sig id 535 channel->sig_id = sig_id; 536 537 // add to connections list 538 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 539 540 // emit incoming connection request 541 l2cap_emit_connection_request(channel); 542 } 543 544 void l2cap_accept_connection_internal(uint16_t local_cid){ 545 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 546 if (!channel) { 547 log_err("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 548 return; 549 } 550 551 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 552 553 // process 554 l2cap_run(); 555 } 556 557 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 558 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 559 if (!channel) { 560 log_err( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 561 return; 562 } 563 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 564 channel->reason = reason; 565 l2cap_run(); 566 } 567 568 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 569 // accept the other's configuration options 570 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 571 uint16_t pos = 8; 572 while (pos < end_pos){ 573 uint8_t type = command[pos++]; 574 uint8_t length = command[pos++]; 575 // MTU { type(8): 1, len(8):2, MTU(16) } 576 if ((type & 0x7f) == 1 && length == 2){ 577 channel->remote_mtu = READ_BT_16(command, pos); 578 // log_dbg("l2cap cid %u, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 579 } 580 pos += length; 581 } 582 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 583 channel->sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 584 } 585 586 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 587 588 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 589 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 590 uint16_t result = 0; 591 592 // log_dbg("signaling handler code %u\n", code); 593 594 switch (channel->state) { 595 596 case L2CAP_STATE_WAIT_CONNECT_RSP: 597 switch (code){ 598 case CONNECTION_RESPONSE: 599 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 600 switch (result) { 601 case 0: 602 // successful connection 603 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 604 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_OR_SEND_CONFIG_REQ; 605 #if 0 606 channel->state = L2CAP_STATE_OPEN; 607 l2cap_emit_channel_opened(channel, 0); // success 608 l2cap_emit_credits(channel, 1); 609 #endif 610 break; 611 case 1: 612 // connection pending. get some coffee 613 break; 614 default: 615 // channel closed 616 channel->state = L2CAP_STATE_CLOSED; 617 618 // map l2cap connection response result to BTstack status enumeration 619 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 620 621 // drop link key if security block 622 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 623 hci_drop_link_key_for_bd_addr(&channel->address); 624 } 625 626 // discard channel 627 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 628 free (channel); 629 break; 630 } 631 break; 632 633 case DISCONNECTION_REQUEST: 634 l2cap_handle_disconnect_request(channel, identifier); 635 break; 636 637 default: 638 //@TODO: implement other signaling packets 639 break; 640 } 641 break; 642 643 case L2CAP_STATE_WAIT_CONFIG_REQ_OR_SEND_CONFIG_REQ: 644 switch (code) { 645 case CONFIGURE_REQUEST: 646 l2cap_signaling_handle_configure_request(channel, command); 647 channel->state = L2CAP_STATE_WILL_SEND_CONFIG_REQ_AND_CONFIG_REQ_RSP; 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_CONFIG_REQ_RSP_OR_CONFIG_REQ: 659 switch (code) { 660 case CONFIGURE_RESPONSE: 661 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ; 662 break; 663 case CONFIGURE_REQUEST: 664 l2cap_signaling_handle_configure_request(channel, command); 665 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_WILL_SEND_CONFIG_REQ_RSP; 666 break; 667 case DISCONNECTION_REQUEST: 668 l2cap_handle_disconnect_request(channel, identifier); 669 break; 670 default: 671 //@TODO: implement other signaling packets 672 break; 673 } 674 break; 675 676 case L2CAP_STATE_WAIT_CONFIG_REQ: 677 switch (code) { 678 case CONFIGURE_REQUEST: 679 l2cap_signaling_handle_configure_request(channel, command); 680 channel->state = L2CAP_STATE_WILL_SEND_CONFIG_REQ_RSP; 681 break; 682 case DISCONNECTION_REQUEST: 683 l2cap_handle_disconnect_request(channel, identifier); 684 break; 685 default: 686 //@TODO: implement other signaling packets 687 break; 688 } 689 break; 690 691 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP: 692 switch (code) { 693 case CONFIGURE_RESPONSE: 694 channel->state = L2CAP_STATE_OPEN; 695 l2cap_emit_channel_opened(channel, 0); // success 696 l2cap_emit_credits(channel, 1); 697 break; 698 case DISCONNECTION_REQUEST: 699 l2cap_handle_disconnect_request(channel, identifier); 700 break; 701 default: 702 //@TODO: implement other signaling packets 703 break; 704 } 705 break; 706 707 case L2CAP_STATE_WAIT_DISCONNECT: 708 switch (code) { 709 case DISCONNECTION_RESPONSE: 710 l2cap_finialize_channel_close(channel); 711 break; 712 case DISCONNECTION_REQUEST: 713 l2cap_handle_disconnect_request(channel, identifier); 714 break; 715 default: 716 //@TODO: implement other signaling packets 717 break; 718 } 719 break; 720 721 case L2CAP_STATE_CLOSED: 722 // @TODO handle incoming requests 723 break; 724 725 case L2CAP_STATE_OPEN: 726 switch (code) { 727 case DISCONNECTION_REQUEST: 728 l2cap_handle_disconnect_request(channel, identifier); 729 break; 730 default: 731 //@TODO: implement other signaling packets, e.g. re-configure 732 break; 733 } 734 break; 735 default: 736 break; 737 } 738 // log_dbg("new state %u\n", channel->state); 739 } 740 741 742 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 743 744 // get code, signalind identifier and command len 745 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 746 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 747 uint16_t len = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 748 749 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 750 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 751 return; 752 } 753 754 // general commands without an assigned channel 755 switch(code) { 756 757 case CONNECTION_REQUEST: { 758 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 759 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 760 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 761 break; 762 } 763 764 case ECHO_REQUEST: { 765 // send back packet 766 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, len, &command[L2CAP_SIGNALING_COMMAND_DATA_OFFSET]); 767 break; 768 } 769 770 case INFORMATION_REQUEST: { 771 // we neither support connectionless L2CAP data nor support any flow control modes yet 772 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 773 if (infoType == 2) { 774 uint32_t features = 0; 775 // extended features request supported, however no features present 776 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, 4, &features); 777 } else { 778 // all other types are not supported 779 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 780 } 781 break;; 782 } 783 784 default: 785 break; 786 } 787 788 789 // Get potential destination CID 790 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 791 792 // Find channel for this sig_id and connection handle 793 linked_item_t *it; 794 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 795 l2cap_channel_t * channel = (l2cap_channel_t *) it; 796 if (channel->handle == handle) { 797 if (code & 1) { 798 // match odd commands by previous signaling identifier 799 if (channel->sig_id == sig_id) { 800 l2cap_signaling_handler_channel(channel, command); 801 break; 802 } 803 } else { 804 // match even commands by local channel id 805 if (channel->local_cid == dest_cid) { 806 l2cap_signaling_handler_channel(channel, command); 807 break; 808 } 809 } 810 } 811 } 812 } 813 814 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 815 816 // Get Channel ID 817 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 818 819 // Signaling Packet? 820 if (channel_id == 1) { 821 822 // Get Connection 823 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 824 825 uint16_t command_offset = 8; 826 while (command_offset < size) { 827 828 // handle signaling commands 829 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 830 831 // increment command_offset 832 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 833 } 834 return; 835 } 836 837 // Find channel for this channel_id and connection handle 838 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 839 if (channel) { 840 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 841 } 842 } 843 844 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 845 switch (packet_type) { 846 case HCI_EVENT_PACKET: 847 l2cap_event_handler(packet, size); 848 break; 849 case HCI_ACL_DATA_PACKET: 850 l2cap_acl_handler(packet, size); 851 break; 852 default: 853 break; 854 } 855 } 856 857 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 858 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 859 channel->state = L2CAP_STATE_CLOSED; 860 l2cap_emit_channel_closed(channel); 861 // discard channel 862 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 863 free (channel); 864 } 865 866 l2cap_service_t * l2cap_get_service(uint16_t psm){ 867 linked_item_t *it; 868 869 // close open channels 870 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 871 l2cap_service_t * service = ((l2cap_service_t *) it); 872 if ( service->psm == psm){ 873 return service; 874 }; 875 } 876 return NULL; 877 } 878 879 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 880 // check for alread registered psm // TODO: emit error event 881 l2cap_service_t *service = l2cap_get_service(psm); 882 if (service) return; 883 884 // alloc structure // TODO: emit error event 885 service = malloc(sizeof(l2cap_service_t)); 886 if (!service) return; 887 888 // fill in 889 service->psm = psm; 890 service->mtu = mtu; 891 service->connection = connection; 892 service->packet_handler = packet_handler; 893 894 // add to services list 895 linked_list_add(&l2cap_services, (linked_item_t *) service); 896 } 897 898 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 899 l2cap_service_t *service = l2cap_get_service(psm); 900 if (!service) return; 901 linked_list_remove(&l2cap_services, (linked_item_t *) service); 902 free(service); 903 } 904 905 // 906 void l2cap_close_connection(void *connection){ 907 linked_item_t *it; 908 909 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 910 l2cap_channel_t * channel; 911 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 912 channel = (l2cap_channel_t *) it; 913 if (channel->connection == connection) { 914 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 915 } 916 } 917 918 // unregister services 919 it = (linked_item_t *) &l2cap_services; 920 while (it->next) { 921 l2cap_service_t * service = (l2cap_service_t *) it->next; 922 if (service->connection == connection){ 923 it->next = it->next->next; 924 free(service); 925 } else { 926 it = it->next; 927 } 928 } 929 930 // process 931 l2cap_run(); 932 } 933