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 // open outgoing L2CAP channel 246 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 247 bd_addr_t address, uint16_t psm, uint16_t mtu){ 248 249 // alloc structure 250 l2cap_channel_t * chan = malloc(sizeof(l2cap_channel_t)); 251 // TODO: emit error event 252 if (!chan) return; 253 254 // limit local mtu to max acl packet length 255 if (mtu > hci_max_acl_data_packet_length()) { 256 mtu = hci_max_acl_data_packet_length(); 257 } 258 259 // fill in 260 BD_ADDR_COPY(chan->address, address); 261 chan->psm = psm; 262 chan->handle = 0; 263 chan->connection = connection; 264 chan->packet_handler = packet_handler; 265 chan->remote_mtu = L2CAP_MINIMAL_MTU; 266 chan->local_mtu = mtu; 267 chan->packets_granted = 0; 268 269 // set initial state 270 chan->state = L2CAP_STATE_CLOSED; 271 chan->sig_id = L2CAP_SIG_ID_INVALID; 272 273 // add to connections list 274 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 275 276 // send connection request 277 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 278 hci_send_cmd(&hci_create_connection, address, 0xcc18, 0, 0, 0, 1); 279 } 280 281 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 282 // find channel for local_cid 283 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 284 if (channel) { 285 channel->sig_id = l2cap_next_sig_id(); 286 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 287 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 288 } 289 } 290 291 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 292 linked_item_t *it = (linked_item_t *) &l2cap_channels; 293 while (it->next){ 294 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 295 if ( ! BD_ADDR_CMP( channel->address, address) ){ 296 if (channel->state == L2CAP_STATE_CLOSED) { 297 // failure, forward error code 298 l2cap_emit_channel_opened(channel, status); 299 // discard channel 300 it->next = it->next->next; 301 free (channel); 302 } 303 } else { 304 it = it->next; 305 } 306 } 307 } 308 309 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 310 linked_item_t *it; 311 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 312 l2cap_channel_t * channel = (l2cap_channel_t *) it; 313 if ( ! BD_ADDR_CMP( channel->address, address) ){ 314 if (channel->state == L2CAP_STATE_CLOSED) { 315 // success, start l2cap handshake 316 channel->handle = handle; 317 channel->sig_id = l2cap_next_sig_id(); 318 channel->local_cid = l2cap_next_local_cid(); 319 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 320 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->sig_id, channel->psm, channel->local_cid); 321 } 322 } 323 } 324 } 325 326 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 327 328 bd_addr_t address; 329 hci_con_handle_t handle; 330 linked_item_t *it; 331 332 switch(packet[0]){ 333 334 // handle connection complete events 335 case HCI_EVENT_CONNECTION_COMPLETE: 336 bt_flip_addr(address, &packet[5]); 337 if (packet[2] == 0){ 338 handle = READ_BT_16(packet, 3); 339 l2cap_handle_connection_success_for_addr(address, handle); 340 } else { 341 l2cap_handle_connection_failed_for_addr(address, packet[2]); 342 } 343 break; 344 345 // handle successful create connection cancel command 346 case HCI_EVENT_COMMAND_COMPLETE: 347 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 348 if (packet[5] == 0){ 349 bt_flip_addr(address, &packet[6]); 350 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 351 l2cap_handle_connection_failed_for_addr(address, 0x16); 352 } 353 } 354 break; 355 356 // handle disconnection complete events 357 case HCI_EVENT_DISCONNECTION_COMPLETE: 358 // send l2cap disconnect events for all channels on this handle 359 handle = READ_BT_16(packet, 3); 360 it = (linked_item_t *) &l2cap_channels; 361 while (it->next){ 362 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 363 if ( channel->handle == handle ){ 364 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 365 it->next = it->next->next; 366 l2cap_emit_channel_closed(channel); 367 free (channel); 368 } else { 369 it = it->next; 370 } 371 } 372 break; 373 374 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 375 l2cap_hand_out_credits(); 376 break; 377 378 // HCI Connection Timeouts 379 case L2CAP_EVENT_TIMEOUT_CHECK: 380 handle = READ_BT_16(packet, 2); 381 if (hci_authentication_active_for_handle(handle)) break; 382 l2cap_channel_t * channel; 383 int used = 0; 384 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 385 channel = (l2cap_channel_t *) it; 386 if (channel->handle == handle) { 387 used = 1; 388 } 389 } 390 if (!used) { 391 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 392 } 393 break; 394 395 default: 396 break; 397 } 398 399 // pass on 400 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 401 } 402 403 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 404 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, identifier, channel->local_cid, channel->remote_cid); 405 l2cap_finialize_channel_close(channel); 406 } 407 408 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 409 410 // log_dbg("l2cap_handle_connection_request for handle %u, psm %u cid %u\n", handle, psm, source_cid); 411 l2cap_service_t *service = l2cap_get_service(psm); 412 if (!service) { 413 // 0x0002 PSM not supported 414 // log_dbg("l2cap_handle_connection_request no PSM for psm %u/n", psm); 415 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, 0x0002, 0); 416 return; 417 } 418 419 hci_connection_t * hci_connection = connection_for_handle( handle ); 420 if (!hci_connection) { 421 log_err("no hci_connection for handle %u\n", handle); 422 // TODO: emit error 423 return; 424 } 425 // alloc structure 426 // log_dbg("l2cap_handle_connection_request register channel\n"); 427 l2cap_channel_t * channel = malloc(sizeof(l2cap_channel_t)); 428 // TODO: emit error event 429 if (!channel) return; 430 431 // fill in 432 BD_ADDR_COPY(channel->address, hci_connection->address); 433 channel->psm = psm; 434 channel->handle = handle; 435 channel->connection = service->connection; 436 channel->packet_handler = service->packet_handler; 437 channel->local_cid = l2cap_next_local_cid(); 438 channel->remote_cid = source_cid; 439 channel->local_mtu = service->mtu; 440 channel->remote_mtu = L2CAP_DEFAULT_MTU; 441 channel->packets_granted = 0; 442 443 // limit local mtu to max acl packet length 444 if (channel->local_mtu > hci_max_acl_data_packet_length()) { 445 channel->local_mtu = hci_max_acl_data_packet_length(); 446 } 447 448 // set initial state 449 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 450 451 // temp. store req sig id 452 channel->sig_id = sig_id; 453 454 // add to connections list 455 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 456 457 // emit incoming connection request 458 l2cap_emit_connection_request(channel); 459 } 460 461 void l2cap_accept_connection_internal(uint16_t local_cid){ 462 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 463 if (!channel) { 464 log_err("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 465 return; 466 } 467 468 // accept connection 469 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, channel->local_cid, channel->remote_cid, 0, 0); 470 471 // set real sig and state and start config 472 channel->sig_id = l2cap_next_sig_id(); 473 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 474 uint8_t config_options[4]; 475 config_options[0] = 1; // MTU 476 config_options[1] = 2; // len param 477 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 478 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 479 480 // log_dbg("new state %u\n", channel->state); 481 } 482 483 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 484 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 485 if (!channel) { 486 log_err( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 487 return; 488 } 489 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, 0, 0, reason, 0); 490 491 // discard channel 492 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 493 free (channel); 494 } 495 496 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 497 // accept the other's configuration options 498 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 499 uint16_t pos = 8; 500 while (pos < end_pos){ 501 uint8_t type = command[pos++]; 502 uint8_t length = command[pos++]; 503 // MTU { type(8): 1, len(8):2, MTU(16) } 504 if ((type & 0x7f) == 1 && length == 2){ 505 channel->remote_mtu = READ_BT_16(command, pos); 506 // log_dbg("l2cap cid %u, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 507 } 508 pos += length; 509 } 510 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 511 // send back OK 512 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->remote_cid, 0, 0, 0, NULL); 513 } 514 515 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 516 517 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 518 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 519 uint16_t result = 0; 520 uint8_t config_options[4]; 521 522 // log_dbg("signaling handler code %u\n", code); 523 524 switch (channel->state) { 525 526 case L2CAP_STATE_WAIT_CONNECT_RSP: 527 switch (code){ 528 case CONNECTION_RESPONSE: 529 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 530 switch (result) { 531 case 0: 532 // successful connection 533 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 534 channel->sig_id = l2cap_next_sig_id(); 535 config_options[0] = 1; // MTU 536 config_options[1] = 2; // len param 537 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 538 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 539 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 540 541 #if 0 542 channel->state = L2CAP_STATE_OPEN; 543 l2cap_emit_channel_opened(channel, 0); // success 544 l2cap_emit_credits(channel, 1); 545 #endif 546 break; 547 case 1: 548 // connection pending. get some coffee 549 break; 550 default: 551 // channel closed 552 channel->state = L2CAP_STATE_CLOSED; 553 554 // map l2cap connection response result to BTstack status enumeration 555 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 556 557 // drop link key if security block 558 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 559 hci_drop_link_key_for_bd_addr(&channel->address); 560 } 561 562 // discard channel 563 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 564 free (channel); 565 break; 566 } 567 break; 568 569 case DISCONNECTION_REQUEST: 570 l2cap_handle_disconnect_request(channel, identifier); 571 break; 572 573 default: 574 //@TODO: implement other signaling packets 575 break; 576 } 577 break; 578 579 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ: 580 switch (code) { 581 case CONFIGURE_RESPONSE: 582 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ; 583 break; 584 case CONFIGURE_REQUEST: 585 l2cap_signaling_handle_configure_request(channel, command); 586 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP; 587 break; 588 case DISCONNECTION_REQUEST: 589 l2cap_handle_disconnect_request(channel, identifier); 590 break; 591 default: 592 //@TODO: implement other signaling packets 593 break; 594 } 595 break; 596 597 case L2CAP_STATE_WAIT_CONFIG_REQ: 598 switch (code) { 599 case CONFIGURE_REQUEST: 600 l2cap_signaling_handle_configure_request(channel, command); 601 channel->state = L2CAP_STATE_OPEN; 602 l2cap_emit_channel_opened(channel, 0); // success 603 l2cap_emit_credits(channel, 1); 604 break; 605 case DISCONNECTION_REQUEST: 606 l2cap_handle_disconnect_request(channel, identifier); 607 break; 608 default: 609 //@TODO: implement other signaling packets 610 break; 611 } 612 break; 613 614 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP: 615 switch (code) { 616 case CONFIGURE_RESPONSE: 617 channel->state = L2CAP_STATE_OPEN; 618 l2cap_emit_channel_opened(channel, 0); // success 619 l2cap_emit_credits(channel, 1); 620 break; 621 case DISCONNECTION_REQUEST: 622 l2cap_handle_disconnect_request(channel, identifier); 623 break; 624 default: 625 //@TODO: implement other signaling packets 626 break; 627 } 628 break; 629 630 case L2CAP_STATE_WAIT_DISCONNECT: 631 switch (code) { 632 case DISCONNECTION_RESPONSE: 633 l2cap_finialize_channel_close(channel); 634 break; 635 case DISCONNECTION_REQUEST: 636 l2cap_handle_disconnect_request(channel, identifier); 637 break; 638 default: 639 //@TODO: implement other signaling packets 640 break; 641 } 642 break; 643 644 case L2CAP_STATE_CLOSED: 645 // @TODO handle incoming requests 646 break; 647 648 case L2CAP_STATE_OPEN: 649 switch (code) { 650 case DISCONNECTION_REQUEST: 651 l2cap_handle_disconnect_request(channel, identifier); 652 break; 653 default: 654 //@TODO: implement other signaling packets, e.g. re-configure 655 break; 656 } 657 break; 658 default: 659 break; 660 } 661 // log_dbg("new state %u\n", channel->state); 662 } 663 664 665 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 666 667 // get code, signalind identifier and command len 668 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 669 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 670 uint16_t len = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 671 672 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 673 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 674 return; 675 } 676 677 // general commands without an assigned channel 678 switch(code) { 679 680 case CONNECTION_REQUEST: { 681 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 682 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 683 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 684 break; 685 } 686 687 case ECHO_REQUEST: { 688 // send back packet 689 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, len, &command[L2CAP_SIGNALING_COMMAND_DATA_OFFSET]); 690 break; 691 } 692 693 case INFORMATION_REQUEST: { 694 // we neither support connectionless L2CAP data nor support any flow control modes yet 695 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 696 if (infoType == 2) { 697 uint32_t features = 0; 698 // extended features request supported, however no features present 699 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, 4, &features); 700 } else { 701 // all other types are not supported 702 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 703 } 704 break;; 705 } 706 707 default: 708 break; 709 } 710 711 712 // Get potential destination CID 713 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 714 715 // Find channel for this sig_id and connection handle 716 linked_item_t *it; 717 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 718 l2cap_channel_t * channel = (l2cap_channel_t *) it; 719 if (channel->handle == handle) { 720 if (code & 1) { 721 // match odd commands by previous signaling identifier 722 if (channel->sig_id == sig_id) { 723 l2cap_signaling_handler_channel(channel, command); 724 break; 725 } 726 } else { 727 // match even commands by local channel id 728 if (channel->local_cid == dest_cid) { 729 l2cap_signaling_handler_channel(channel, command); 730 break; 731 } 732 } 733 } 734 } 735 } 736 737 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 738 739 // Get Channel ID 740 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 741 742 // Signaling Packet? 743 if (channel_id == 1) { 744 745 // Get Connection 746 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 747 748 uint16_t command_offset = 8; 749 while (command_offset < size) { 750 751 // handle signaling commands 752 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 753 754 // increment command_offset 755 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 756 } 757 return; 758 } 759 760 // Find channel for this channel_id and connection handle 761 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 762 if (channel) { 763 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 764 } 765 } 766 767 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 768 switch (packet_type) { 769 case HCI_EVENT_PACKET: 770 l2cap_event_handler(packet, size); 771 break; 772 case HCI_ACL_DATA_PACKET: 773 l2cap_acl_handler(packet, size); 774 break; 775 default: 776 break; 777 } 778 } 779 780 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 781 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 782 channel->state = L2CAP_STATE_CLOSED; 783 l2cap_emit_channel_closed(channel); 784 // discard channel 785 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 786 free (channel); 787 } 788 789 l2cap_service_t * l2cap_get_service(uint16_t psm){ 790 linked_item_t *it; 791 792 // close open channels 793 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 794 l2cap_service_t * service = ((l2cap_service_t *) it); 795 if ( service->psm == psm){ 796 return service; 797 }; 798 } 799 return NULL; 800 } 801 802 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 803 // check for alread registered psm // TODO: emit error event 804 l2cap_service_t *service = l2cap_get_service(psm); 805 if (service) return; 806 807 // alloc structure // TODO: emit error event 808 service = malloc(sizeof(l2cap_service_t)); 809 if (!service) return; 810 811 // fill in 812 service->psm = psm; 813 service->mtu = mtu; 814 service->connection = connection; 815 service->packet_handler = packet_handler; 816 817 // add to services list 818 linked_list_add(&l2cap_services, (linked_item_t *) service); 819 } 820 821 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 822 l2cap_service_t *service = l2cap_get_service(psm); 823 if (!service) return; 824 linked_list_remove(&l2cap_services, (linked_item_t *) service); 825 free(service); 826 } 827 828 // 829 void l2cap_close_connection(void *connection){ 830 linked_item_t *it; 831 832 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 833 l2cap_channel_t * channel; 834 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 835 channel = (l2cap_channel_t *) it; 836 if (channel->connection == connection) { 837 channel->sig_id = l2cap_next_sig_id(); 838 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 839 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 840 } 841 } 842 843 // unregister services 844 it = (linked_item_t *) &l2cap_services; 845 while (it->next) { 846 l2cap_service_t * service = (l2cap_service_t *) it->next; 847 if (service->connection == connection){ 848 it->next = it->next->next; 849 free(service); 850 } else { 851 it = it->next; 852 } 853 } 854 } 855