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