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_DISCONNECT: 256 channel->sig_id = l2cap_next_sig_id(); 257 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 258 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 259 break; 260 261 default: 262 break; 263 } 264 } 265 } 266 267 // open outgoing L2CAP channel 268 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 269 bd_addr_t address, uint16_t psm, uint16_t mtu){ 270 271 // alloc structure 272 l2cap_channel_t * chan = malloc(sizeof(l2cap_channel_t)); 273 // TODO: emit error event 274 if (!chan) return; 275 276 // limit local mtu to max acl packet length 277 if (mtu > hci_max_acl_data_packet_length()) { 278 mtu = hci_max_acl_data_packet_length(); 279 } 280 281 // fill in 282 BD_ADDR_COPY(chan->address, address); 283 chan->psm = psm; 284 chan->handle = 0; 285 chan->connection = connection; 286 chan->packet_handler = packet_handler; 287 chan->remote_mtu = L2CAP_MINIMAL_MTU; 288 chan->local_mtu = mtu; 289 chan->packets_granted = 0; 290 291 // set initial state 292 chan->state = L2CAP_STATE_CLOSED; 293 chan->sig_id = L2CAP_SIG_ID_INVALID; 294 295 // add to connections list 296 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 297 298 // send connection request 299 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 300 hci_send_cmd(&hci_create_connection, address, 0xcc18, 0, 0, 0, 1); 301 } 302 303 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 304 // find channel for local_cid 305 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 306 if (channel) { 307 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT; 308 } 309 // process 310 l2cap_run(); 311 } 312 313 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 314 linked_item_t *it = (linked_item_t *) &l2cap_channels; 315 while (it->next){ 316 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 317 if ( ! BD_ADDR_CMP( channel->address, address) ){ 318 if (channel->state == L2CAP_STATE_CLOSED) { 319 // failure, forward error code 320 l2cap_emit_channel_opened(channel, status); 321 // discard channel 322 it->next = it->next->next; 323 free (channel); 324 } 325 } else { 326 it = it->next; 327 } 328 } 329 } 330 331 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 332 linked_item_t *it; 333 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 334 l2cap_channel_t * channel = (l2cap_channel_t *) it; 335 if ( ! BD_ADDR_CMP( channel->address, address) ){ 336 if (channel->state == L2CAP_STATE_CLOSED) { 337 // success, start l2cap handshake 338 channel->handle = handle; 339 channel->sig_id = l2cap_next_sig_id(); 340 channel->local_cid = l2cap_next_local_cid(); 341 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 342 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->sig_id, channel->psm, channel->local_cid); 343 } 344 } 345 } 346 } 347 348 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 349 350 bd_addr_t address; 351 hci_con_handle_t handle; 352 linked_item_t *it; 353 354 switch(packet[0]){ 355 356 // handle connection complete events 357 case HCI_EVENT_CONNECTION_COMPLETE: 358 bt_flip_addr(address, &packet[5]); 359 if (packet[2] == 0){ 360 handle = READ_BT_16(packet, 3); 361 l2cap_handle_connection_success_for_addr(address, handle); 362 } else { 363 l2cap_handle_connection_failed_for_addr(address, packet[2]); 364 } 365 break; 366 367 // handle successful create connection cancel command 368 case HCI_EVENT_COMMAND_COMPLETE: 369 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 370 if (packet[5] == 0){ 371 bt_flip_addr(address, &packet[6]); 372 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 373 l2cap_handle_connection_failed_for_addr(address, 0x16); 374 } 375 } 376 break; 377 378 // handle disconnection complete events 379 case HCI_EVENT_DISCONNECTION_COMPLETE: 380 // send l2cap disconnect events for all channels on this handle 381 handle = READ_BT_16(packet, 3); 382 it = (linked_item_t *) &l2cap_channels; 383 while (it->next){ 384 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 385 if ( channel->handle == handle ){ 386 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 387 it->next = it->next->next; 388 l2cap_emit_channel_closed(channel); 389 free (channel); 390 } else { 391 it = it->next; 392 } 393 } 394 break; 395 396 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 397 l2cap_hand_out_credits(); 398 break; 399 400 // HCI Connection Timeouts 401 case L2CAP_EVENT_TIMEOUT_CHECK: 402 handle = READ_BT_16(packet, 2); 403 if (hci_authentication_active_for_handle(handle)) break; 404 l2cap_channel_t * channel; 405 int used = 0; 406 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 407 channel = (l2cap_channel_t *) it; 408 if (channel->handle == handle) { 409 used = 1; 410 } 411 } 412 if (!used) { 413 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 414 } 415 break; 416 417 default: 418 break; 419 } 420 421 // pass on 422 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 423 } 424 425 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 426 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, identifier, channel->local_cid, channel->remote_cid); 427 l2cap_finialize_channel_close(channel); 428 } 429 430 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 431 432 // log_dbg("l2cap_handle_connection_request for handle %u, psm %u cid %u\n", handle, psm, source_cid); 433 l2cap_service_t *service = l2cap_get_service(psm); 434 if (!service) { 435 // 0x0002 PSM not supported 436 // log_dbg("l2cap_handle_connection_request no PSM for psm %u/n", psm); 437 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, 0x0002, 0); 438 return; 439 } 440 441 hci_connection_t * hci_connection = connection_for_handle( handle ); 442 if (!hci_connection) { 443 log_err("no hci_connection for handle %u\n", handle); 444 // TODO: emit error 445 return; 446 } 447 // alloc structure 448 // log_dbg("l2cap_handle_connection_request register channel\n"); 449 l2cap_channel_t * channel = malloc(sizeof(l2cap_channel_t)); 450 // TODO: emit error event 451 if (!channel) return; 452 453 // fill in 454 BD_ADDR_COPY(channel->address, hci_connection->address); 455 channel->psm = psm; 456 channel->handle = handle; 457 channel->connection = service->connection; 458 channel->packet_handler = service->packet_handler; 459 channel->local_cid = l2cap_next_local_cid(); 460 channel->remote_cid = source_cid; 461 channel->local_mtu = service->mtu; 462 channel->remote_mtu = L2CAP_DEFAULT_MTU; 463 channel->packets_granted = 0; 464 465 // limit local mtu to max acl packet length 466 if (channel->local_mtu > hci_max_acl_data_packet_length()) { 467 channel->local_mtu = hci_max_acl_data_packet_length(); 468 } 469 470 // set initial state 471 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 472 473 // temp. store req sig id 474 channel->sig_id = sig_id; 475 476 // add to connections list 477 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 478 479 // emit incoming connection request 480 l2cap_emit_connection_request(channel); 481 } 482 483 void l2cap_accept_connection_internal(uint16_t local_cid){ 484 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 485 if (!channel) { 486 log_err("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 487 return; 488 } 489 490 // accept connection 491 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, channel->local_cid, channel->remote_cid, 0, 0); 492 493 // set real sig and state and start config 494 channel->sig_id = l2cap_next_sig_id(); 495 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 496 uint8_t config_options[4]; 497 config_options[0] = 1; // MTU 498 config_options[1] = 2; // len param 499 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 500 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 501 502 // log_dbg("new state %u\n", channel->state); 503 } 504 505 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 506 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 507 if (!channel) { 508 log_err( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 509 return; 510 } 511 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, 0, 0, reason, 0); 512 513 // discard channel 514 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 515 free (channel); 516 } 517 518 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 519 // accept the other's configuration options 520 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 521 uint16_t pos = 8; 522 while (pos < end_pos){ 523 uint8_t type = command[pos++]; 524 uint8_t length = command[pos++]; 525 // MTU { type(8): 1, len(8):2, MTU(16) } 526 if ((type & 0x7f) == 1 && length == 2){ 527 channel->remote_mtu = READ_BT_16(command, pos); 528 // log_dbg("l2cap cid %u, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 529 } 530 pos += length; 531 } 532 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 533 // send back OK 534 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->remote_cid, 0, 0, 0, NULL); 535 } 536 537 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 538 539 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 540 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 541 uint16_t result = 0; 542 uint8_t config_options[4]; 543 544 // log_dbg("signaling handler code %u\n", code); 545 546 switch (channel->state) { 547 548 case L2CAP_STATE_WAIT_CONNECT_RSP: 549 switch (code){ 550 case CONNECTION_RESPONSE: 551 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 552 switch (result) { 553 case 0: 554 // successful connection 555 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 556 channel->sig_id = l2cap_next_sig_id(); 557 config_options[0] = 1; // MTU 558 config_options[1] = 2; // len param 559 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 560 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 561 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 562 563 #if 0 564 channel->state = L2CAP_STATE_OPEN; 565 l2cap_emit_channel_opened(channel, 0); // success 566 l2cap_emit_credits(channel, 1); 567 #endif 568 break; 569 case 1: 570 // connection pending. get some coffee 571 break; 572 default: 573 // channel closed 574 channel->state = L2CAP_STATE_CLOSED; 575 576 // map l2cap connection response result to BTstack status enumeration 577 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 578 579 // drop link key if security block 580 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 581 hci_drop_link_key_for_bd_addr(&channel->address); 582 } 583 584 // discard channel 585 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 586 free (channel); 587 break; 588 } 589 break; 590 591 case DISCONNECTION_REQUEST: 592 l2cap_handle_disconnect_request(channel, identifier); 593 break; 594 595 default: 596 //@TODO: implement other signaling packets 597 break; 598 } 599 break; 600 601 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ: 602 switch (code) { 603 case CONFIGURE_RESPONSE: 604 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ; 605 break; 606 case CONFIGURE_REQUEST: 607 l2cap_signaling_handle_configure_request(channel, command); 608 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP; 609 break; 610 case DISCONNECTION_REQUEST: 611 l2cap_handle_disconnect_request(channel, identifier); 612 break; 613 default: 614 //@TODO: implement other signaling packets 615 break; 616 } 617 break; 618 619 case L2CAP_STATE_WAIT_CONFIG_REQ: 620 switch (code) { 621 case CONFIGURE_REQUEST: 622 l2cap_signaling_handle_configure_request(channel, command); 623 channel->state = L2CAP_STATE_OPEN; 624 l2cap_emit_channel_opened(channel, 0); // success 625 l2cap_emit_credits(channel, 1); 626 break; 627 case DISCONNECTION_REQUEST: 628 l2cap_handle_disconnect_request(channel, identifier); 629 break; 630 default: 631 //@TODO: implement other signaling packets 632 break; 633 } 634 break; 635 636 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP: 637 switch (code) { 638 case CONFIGURE_RESPONSE: 639 channel->state = L2CAP_STATE_OPEN; 640 l2cap_emit_channel_opened(channel, 0); // success 641 l2cap_emit_credits(channel, 1); 642 break; 643 case DISCONNECTION_REQUEST: 644 l2cap_handle_disconnect_request(channel, identifier); 645 break; 646 default: 647 //@TODO: implement other signaling packets 648 break; 649 } 650 break; 651 652 case L2CAP_STATE_WAIT_DISCONNECT: 653 switch (code) { 654 case DISCONNECTION_RESPONSE: 655 l2cap_finialize_channel_close(channel); 656 break; 657 case DISCONNECTION_REQUEST: 658 l2cap_handle_disconnect_request(channel, identifier); 659 break; 660 default: 661 //@TODO: implement other signaling packets 662 break; 663 } 664 break; 665 666 case L2CAP_STATE_CLOSED: 667 // @TODO handle incoming requests 668 break; 669 670 case L2CAP_STATE_OPEN: 671 switch (code) { 672 case DISCONNECTION_REQUEST: 673 l2cap_handle_disconnect_request(channel, identifier); 674 break; 675 default: 676 //@TODO: implement other signaling packets, e.g. re-configure 677 break; 678 } 679 break; 680 default: 681 break; 682 } 683 // log_dbg("new state %u\n", channel->state); 684 } 685 686 687 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 688 689 // get code, signalind identifier and command len 690 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 691 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 692 uint16_t len = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 693 694 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 695 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 696 return; 697 } 698 699 // general commands without an assigned channel 700 switch(code) { 701 702 case CONNECTION_REQUEST: { 703 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 704 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 705 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 706 break; 707 } 708 709 case ECHO_REQUEST: { 710 // send back packet 711 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, len, &command[L2CAP_SIGNALING_COMMAND_DATA_OFFSET]); 712 break; 713 } 714 715 case INFORMATION_REQUEST: { 716 // we neither support connectionless L2CAP data nor support any flow control modes yet 717 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 718 if (infoType == 2) { 719 uint32_t features = 0; 720 // extended features request supported, however no features present 721 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, 4, &features); 722 } else { 723 // all other types are not supported 724 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 725 } 726 break;; 727 } 728 729 default: 730 break; 731 } 732 733 734 // Get potential destination CID 735 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 736 737 // Find channel for this sig_id and connection handle 738 linked_item_t *it; 739 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 740 l2cap_channel_t * channel = (l2cap_channel_t *) it; 741 if (channel->handle == handle) { 742 if (code & 1) { 743 // match odd commands by previous signaling identifier 744 if (channel->sig_id == sig_id) { 745 l2cap_signaling_handler_channel(channel, command); 746 break; 747 } 748 } else { 749 // match even commands by local channel id 750 if (channel->local_cid == dest_cid) { 751 l2cap_signaling_handler_channel(channel, command); 752 break; 753 } 754 } 755 } 756 } 757 } 758 759 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 760 761 // Get Channel ID 762 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 763 764 // Signaling Packet? 765 if (channel_id == 1) { 766 767 // Get Connection 768 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 769 770 uint16_t command_offset = 8; 771 while (command_offset < size) { 772 773 // handle signaling commands 774 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 775 776 // increment command_offset 777 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 778 } 779 return; 780 } 781 782 // Find channel for this channel_id and connection handle 783 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 784 if (channel) { 785 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 786 } 787 } 788 789 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 790 switch (packet_type) { 791 case HCI_EVENT_PACKET: 792 l2cap_event_handler(packet, size); 793 break; 794 case HCI_ACL_DATA_PACKET: 795 l2cap_acl_handler(packet, size); 796 break; 797 default: 798 break; 799 } 800 } 801 802 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 803 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 804 channel->state = L2CAP_STATE_CLOSED; 805 l2cap_emit_channel_closed(channel); 806 // discard channel 807 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 808 free (channel); 809 } 810 811 l2cap_service_t * l2cap_get_service(uint16_t psm){ 812 linked_item_t *it; 813 814 // close open channels 815 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 816 l2cap_service_t * service = ((l2cap_service_t *) it); 817 if ( service->psm == psm){ 818 return service; 819 }; 820 } 821 return NULL; 822 } 823 824 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 825 // check for alread registered psm // TODO: emit error event 826 l2cap_service_t *service = l2cap_get_service(psm); 827 if (service) return; 828 829 // alloc structure // TODO: emit error event 830 service = malloc(sizeof(l2cap_service_t)); 831 if (!service) return; 832 833 // fill in 834 service->psm = psm; 835 service->mtu = mtu; 836 service->connection = connection; 837 service->packet_handler = packet_handler; 838 839 // add to services list 840 linked_list_add(&l2cap_services, (linked_item_t *) service); 841 } 842 843 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 844 l2cap_service_t *service = l2cap_get_service(psm); 845 if (!service) return; 846 linked_list_remove(&l2cap_services, (linked_item_t *) service); 847 free(service); 848 } 849 850 // 851 void l2cap_close_connection(void *connection){ 852 linked_item_t *it; 853 854 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 855 l2cap_channel_t * channel; 856 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 857 channel = (l2cap_channel_t *) it; 858 if (channel->connection == connection) { 859 channel->sig_id = l2cap_next_sig_id(); 860 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 861 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 862 } 863 } 864 865 // unregister services 866 it = (linked_item_t *) &l2cap_services; 867 while (it->next) { 868 l2cap_service_t * service = (l2cap_service_t *) it->next; 869 if (service->connection == connection){ 870 it->next = it->next->next; 871 free(service); 872 } else { 873 it = it->next; 874 } 875 } 876 } 877