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 75 void l2cap_init(){ 76 sig_buffer = malloc( L2CAP_MINIMAL_MTU ); 77 acl_buffer = malloc( HCI_ACL_3DH5_SIZE); 78 79 // 80 // register callback with HCI 81 // 82 hci_register_packet_handler(&l2cap_packet_handler); 83 } 84 85 86 /** Register L2CAP packet handlers */ 87 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 88 } 89 void l2cap_register_packet_handler(void (*handler)(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 90 packet_handler = handler; 91 } 92 93 // notify client/protocol handler 94 void l2cap_dispatch(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 95 if (channel->packet_handler) { 96 (* (channel->packet_handler))(type, channel->local_cid, data, size); 97 } else { 98 (*packet_handler)(channel->connection, type, channel->local_cid, data, size); 99 } 100 } 101 102 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 103 uint8_t event[17]; 104 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 105 event[1] = sizeof(event) - 2; 106 event[2] = status; 107 bt_flip_addr(&event[3], channel->address); 108 bt_store_16(event, 9, channel->handle); 109 bt_store_16(event, 11, channel->psm); 110 bt_store_16(event, 13, channel->local_cid); 111 bt_store_16(event, 15, channel->remote_cid); 112 bt_store_16(event, 17, channel->local_mtu); 113 bt_store_16(event, 19, channel->remote_mtu); 114 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 115 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 116 } 117 118 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 119 uint8_t event[4]; 120 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 121 event[1] = sizeof(event) - 2; 122 bt_store_16(event, 2, channel->local_cid); 123 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 124 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 125 } 126 127 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 128 uint8_t event[16]; 129 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 130 event[1] = sizeof(event) - 2; 131 bt_flip_addr(&event[2], channel->address); 132 bt_store_16(event, 8, channel->handle); 133 bt_store_16(event, 10, channel->psm); 134 bt_store_16(event, 12, channel->local_cid); 135 bt_store_16(event, 14, channel->remote_cid); 136 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 137 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 138 } 139 140 void l2cap_emit_credits(l2cap_channel_t *channel, uint8_t credits) { 141 // track credits 142 channel->packets_granted += credits; 143 // log_dbg("l2cap_emit_credits for cid %u, credits now: %u (+%u)\n", channel->local_cid, channel->packets_granted, credits); 144 145 uint8_t event[5]; 146 event[0] = L2CAP_EVENT_CREDITS; 147 event[1] = sizeof(event) - 2; 148 bt_store_16(event, 2, channel->local_cid); 149 event[4] = credits; 150 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 151 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 152 } 153 154 void l2cap_hand_out_credits(void){ 155 linked_item_t *it; 156 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 157 if (!hci_number_free_acl_slots()) return; 158 l2cap_channel_t * channel = (l2cap_channel_t *) it; 159 if (channel->state != L2CAP_STATE_OPEN) continue; 160 if (hci_number_outgoing_packets(channel->handle) < NR_BUFFERED_ACL_PACKETS && channel->packets_granted == 0) { 161 l2cap_emit_credits(channel, 1); 162 } 163 } 164 } 165 166 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 167 linked_item_t *it; 168 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 169 l2cap_channel_t * channel = (l2cap_channel_t *) it; 170 if ( channel->local_cid == local_cid) { 171 return channel; 172 } 173 } 174 return NULL; 175 } 176 177 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 178 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 179 if (channel) { 180 return channel->remote_mtu; 181 } 182 return 0; 183 } 184 185 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 186 // log_dbg("l2cap_send_signaling_packet type %u\n", cmd); 187 va_list argptr; 188 va_start(argptr, identifier); 189 uint16_t len = l2cap_create_signaling_internal(sig_buffer, handle, cmd, identifier, argptr); 190 va_end(argptr); 191 return hci_send_acl_packet(sig_buffer, len); 192 } 193 194 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 195 196 // check for free places on BT module 197 if (!hci_number_free_acl_slots()) { 198 log_dbg("l2cap_send_internal cid %u, BT module full <-----\n", local_cid); 199 return -1; 200 } 201 int err = 0; 202 203 // find channel for local_cid, construct l2cap packet and send 204 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 205 if (channel) { 206 // track sending 207 ++channel->packets_outgoing; 208 if (channel->packets_granted > 0){ 209 --channel->packets_granted; 210 // log_dbg("l2cap_send_internal cid %u, 1 credit used, credits left %u; outgoing count %u\n", 211 // local_cid, channel->packets_granted, channel->packets_outgoing); 212 } else { 213 log_err("l2cap_send_internal cid %u, no credits!\n", local_cid); 214 } 215 216 // 0 - Connection handle : PB=10 : BC=00 217 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 218 // 2 - ACL length 219 bt_store_16(acl_buffer, 2, len + 4); 220 // 4 - L2CAP packet length 221 bt_store_16(acl_buffer, 4, len + 0); 222 // 6 - L2CAP channel DEST 223 bt_store_16(acl_buffer, 6, channel->remote_cid); 224 // 8 - data 225 memcpy(&acl_buffer[8], data, len); 226 227 // send 228 err = hci_send_acl_packet(acl_buffer, len+8); 229 } 230 231 l2cap_hand_out_credits(); 232 233 return err; 234 } 235 236 // open outgoing L2CAP channel 237 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 238 bd_addr_t address, uint16_t psm, uint16_t mtu){ 239 240 // alloc structure 241 l2cap_channel_t * chan = malloc(sizeof(l2cap_channel_t)); 242 // TODO: emit error event 243 if (!chan) return; 244 245 // limit local mtu to max acl packet length 246 if (mtu > hci_max_acl_data_packet_length()) { 247 mtu = hci_max_acl_data_packet_length(); 248 } 249 250 // fill in 251 BD_ADDR_COPY(chan->address, address); 252 chan->psm = psm; 253 chan->handle = 0; 254 chan->connection = connection; 255 chan->packet_handler = packet_handler; 256 chan->remote_mtu = L2CAP_MINIMAL_MTU; 257 chan->local_mtu = mtu; 258 259 // flow control 260 chan->packets_granted = 0; 261 chan->packets_outgoing = 0; 262 263 // set initial state 264 chan->state = L2CAP_STATE_CLOSED; 265 chan->sig_id = L2CAP_SIG_ID_INVALID; 266 267 // add to connections list 268 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 269 270 // send connection request 271 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 272 hci_send_cmd(&hci_create_connection, address, 0xcc18, 0, 0, 0, 1); 273 } 274 275 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 276 // find channel for local_cid 277 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 278 if (channel) { 279 channel->sig_id = l2cap_next_sig_id(); 280 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 281 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 282 } 283 } 284 285 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 286 linked_item_t *it = (linked_item_t *) &l2cap_channels; 287 while (it->next){ 288 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 289 if ( ! BD_ADDR_CMP( channel->address, address) ){ 290 if (channel->state == L2CAP_STATE_CLOSED) { 291 // failure, forward error code 292 l2cap_emit_channel_opened(channel, status); 293 // discard channel 294 it->next = it->next->next; 295 free (channel); 296 } 297 } else { 298 it = it->next; 299 } 300 } 301 } 302 303 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 304 linked_item_t *it; 305 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 306 l2cap_channel_t * channel = (l2cap_channel_t *) it; 307 if ( ! BD_ADDR_CMP( channel->address, address) ){ 308 if (channel->state == L2CAP_STATE_CLOSED) { 309 // success, start l2cap handshake 310 channel->handle = handle; 311 channel->sig_id = l2cap_next_sig_id(); 312 channel->local_cid = l2cap_next_local_cid(); 313 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 314 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->sig_id, channel->psm, channel->local_cid); 315 } 316 } 317 } 318 } 319 320 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 321 322 bd_addr_t address; 323 hci_con_handle_t handle; 324 linked_item_t *it; 325 int i; 326 327 switch(packet[0]){ 328 329 // handle connection complete events 330 case HCI_EVENT_CONNECTION_COMPLETE: 331 bt_flip_addr(address, &packet[5]); 332 if (packet[2] == 0){ 333 handle = READ_BT_16(packet, 3); 334 l2cap_handle_connection_success_for_addr(address, handle); 335 } else { 336 l2cap_handle_connection_failed_for_addr(address, packet[2]); 337 } 338 break; 339 340 // handle successful create connection cancel command 341 case HCI_EVENT_COMMAND_COMPLETE: 342 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 343 if (packet[5] == 0){ 344 bt_flip_addr(address, &packet[6]); 345 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 346 l2cap_handle_connection_failed_for_addr(address, 0x16); 347 } 348 } 349 break; 350 351 // handle disconnection complete events 352 case HCI_EVENT_DISCONNECTION_COMPLETE: 353 // send l2cap disconnect events for all channels on this handle 354 handle = READ_BT_16(packet, 3); 355 it = (linked_item_t *) &l2cap_channels; 356 while (it->next){ 357 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 358 if ( channel->handle == handle ){ 359 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 360 it->next = it->next->next; 361 l2cap_emit_channel_closed(channel); 362 free (channel); 363 } else { 364 it = it->next; 365 } 366 } 367 break; 368 369 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 370 for (i=0; i<packet[2];i++){ 371 handle = READ_BT_16(packet, 3 + 2*i); 372 uint16_t num_packets = READ_BT_16(packet, 3 + packet[2]*2 + 2*i); 373 while (num_packets) { 374 375 // find channels with max nr of pending outgoing packets 376 l2cap_channel_t * fullest_channel = NULL; 377 int max_nr_pending = 0; 378 for (it = (linked_item_t *) &l2cap_channels; it->next ; it = it->next){ 379 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 380 if (channel->packets_outgoing > max_nr_pending){ 381 fullest_channel = channel; 382 max_nr_pending = channel->packets_outgoing; 383 } 384 } 385 386 // decrease packets 387 if (fullest_channel) { 388 fullest_channel->packets_outgoing--; 389 // log_dbg("hci_number_completed_packet (l2cap) for cid %u, outgoing count %u\n", 390 // fullest_channel->local_cid, fullest_channel->packets_outgoing); 391 } else { 392 log_err("hci_number_completed_packet but no outgoing packet in records\n"); 393 } 394 395 // handled! 396 num_packets--; 397 } 398 } 399 l2cap_hand_out_credits(); 400 break; 401 402 // HCI Connection Timeouts 403 case L2CAP_EVENT_TIMEOUT_CHECK: 404 handle = READ_BT_16(packet, 2); 405 if (hci_authentication_active_for_handle(handle)) break; 406 l2cap_channel_t * channel; 407 int used = 0; 408 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 409 channel = (l2cap_channel_t *) it; 410 if (channel->handle == handle) { 411 used = 1; 412 } 413 } 414 if (!used) { 415 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 416 } 417 break; 418 419 default: 420 break; 421 } 422 423 // pass on 424 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 425 } 426 427 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 428 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, identifier, channel->local_cid, channel->remote_cid); 429 l2cap_finialize_channel_close(channel); 430 } 431 432 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 433 434 // log_dbg("l2cap_handle_connection_request for handle %u, psm %u cid %u\n", handle, psm, source_cid); 435 l2cap_service_t *service = l2cap_get_service(psm); 436 if (!service) { 437 // 0x0002 PSM not supported 438 // log_dbg("l2cap_handle_connection_request no PSM for psm %u/n", psm); 439 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, 0x0002, 0); 440 return; 441 } 442 443 hci_connection_t * hci_connection = connection_for_handle( handle ); 444 if (!hci_connection) { 445 log_err("no hci_connection for handle %u\n", handle); 446 // TODO: emit error 447 return; 448 } 449 // alloc structure 450 // log_dbg("l2cap_handle_connection_request register channel\n"); 451 l2cap_channel_t * channel = malloc(sizeof(l2cap_channel_t)); 452 // TODO: emit error event 453 if (!channel) return; 454 455 // fill in 456 BD_ADDR_COPY(channel->address, hci_connection->address); 457 channel->psm = psm; 458 channel->handle = handle; 459 channel->connection = service->connection; 460 channel->packet_handler = service->packet_handler; 461 channel->local_cid = l2cap_next_local_cid(); 462 channel->remote_cid = source_cid; 463 channel->local_mtu = service->mtu; 464 channel->remote_mtu = L2CAP_DEFAULT_MTU; 465 466 // limit local mtu to max acl packet length 467 if (channel->local_mtu > hci_max_acl_data_packet_length()) { 468 channel->local_mtu = hci_max_acl_data_packet_length(); 469 } 470 471 // set initial state 472 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 473 474 // temp. store req sig id 475 channel->sig_id = sig_id; 476 477 // add to connections list 478 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 479 480 // emit incoming connection request 481 l2cap_emit_connection_request(channel); 482 } 483 484 void l2cap_accept_connection_internal(uint16_t local_cid){ 485 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 486 if (!channel) { 487 log_err("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 488 return; 489 } 490 491 // accept connection 492 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, channel->local_cid, channel->remote_cid, 0, 0); 493 494 // set real sig and state and start config 495 channel->sig_id = l2cap_next_sig_id(); 496 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 497 uint8_t config_options[4]; 498 config_options[0] = 1; // MTU 499 config_options[1] = 2; // len param 500 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 501 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 502 503 // log_dbg("new state %u\n", channel->state); 504 } 505 506 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 507 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 508 if (!channel) { 509 log_err( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 510 return; 511 } 512 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, 0, 0, reason, 0); 513 514 // discard channel 515 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 516 free (channel); 517 } 518 519 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 520 // accept the other's configuration options 521 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 522 uint16_t pos = 8; 523 while (pos < end_pos){ 524 uint8_t type = command[pos++]; 525 uint8_t length = command[pos++]; 526 // MTU { type(8): 1, len(8):2, MTU(16) } 527 if ((type & 0x7f) == 1 && length == 2){ 528 channel->remote_mtu = READ_BT_16(command, pos); 529 // log_dbg("l2cap cid %u, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 530 } 531 pos += length; 532 } 533 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 534 // send back OK 535 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->remote_cid, 0, 0, 0, NULL); 536 } 537 538 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 539 540 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 541 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 542 uint16_t result = 0; 543 uint8_t config_options[4]; 544 545 // log_dbg("signaling handler code %u\n", code); 546 547 switch (channel->state) { 548 549 case L2CAP_STATE_WAIT_CONNECT_RSP: 550 switch (code){ 551 case CONNECTION_RESPONSE: 552 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 553 switch (result) { 554 case 0: 555 // successful connection 556 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 557 channel->sig_id = l2cap_next_sig_id(); 558 config_options[0] = 1; // MTU 559 config_options[1] = 2; // len param 560 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 561 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 562 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 563 564 #if 0 565 channel->state = L2CAP_STATE_OPEN; 566 l2cap_emit_channel_opened(channel, 0); // success 567 l2cap_emit_credits(channel, 1); 568 #endif 569 break; 570 case 1: 571 // connection pending. get some coffee 572 break; 573 default: 574 // channel closed 575 channel->state = L2CAP_STATE_CLOSED; 576 577 // map l2cap connection response result to BTstack status enumeration 578 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 579 580 // drop link key if security block 581 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 582 hci_drop_link_key_for_bd_addr(&channel->address); 583 } 584 585 // discard channel 586 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 587 free (channel); 588 break; 589 } 590 break; 591 592 case DISCONNECTION_REQUEST: 593 l2cap_handle_disconnect_request(channel, identifier); 594 break; 595 596 default: 597 //@TODO: implement other signaling packets 598 break; 599 } 600 break; 601 602 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ: 603 switch (code) { 604 case CONFIGURE_RESPONSE: 605 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ; 606 break; 607 case CONFIGURE_REQUEST: 608 l2cap_signaling_handle_configure_request(channel, command); 609 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP; 610 break; 611 case DISCONNECTION_REQUEST: 612 l2cap_handle_disconnect_request(channel, identifier); 613 break; 614 default: 615 //@TODO: implement other signaling packets 616 break; 617 } 618 break; 619 620 case L2CAP_STATE_WAIT_CONFIG_REQ: 621 switch (code) { 622 case CONFIGURE_REQUEST: 623 l2cap_signaling_handle_configure_request(channel, command); 624 channel->state = L2CAP_STATE_OPEN; 625 l2cap_emit_channel_opened(channel, 0); // success 626 l2cap_emit_credits(channel, 1); 627 break; 628 case DISCONNECTION_REQUEST: 629 l2cap_handle_disconnect_request(channel, identifier); 630 break; 631 default: 632 //@TODO: implement other signaling packets 633 break; 634 } 635 break; 636 637 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP: 638 switch (code) { 639 case CONFIGURE_RESPONSE: 640 channel->state = L2CAP_STATE_OPEN; 641 l2cap_emit_channel_opened(channel, 0); // success 642 l2cap_emit_credits(channel, 1); 643 break; 644 case DISCONNECTION_REQUEST: 645 l2cap_handle_disconnect_request(channel, identifier); 646 break; 647 default: 648 //@TODO: implement other signaling packets 649 break; 650 } 651 break; 652 653 case L2CAP_STATE_WAIT_DISCONNECT: 654 switch (code) { 655 case DISCONNECTION_RESPONSE: 656 l2cap_finialize_channel_close(channel); 657 break; 658 case DISCONNECTION_REQUEST: 659 l2cap_handle_disconnect_request(channel, identifier); 660 break; 661 default: 662 //@TODO: implement other signaling packets 663 break; 664 } 665 break; 666 667 case L2CAP_STATE_CLOSED: 668 // @TODO handle incoming requests 669 break; 670 671 case L2CAP_STATE_OPEN: 672 switch (code) { 673 case DISCONNECTION_REQUEST: 674 l2cap_handle_disconnect_request(channel, identifier); 675 break; 676 default: 677 //@TODO: implement other signaling packets, e.g. re-configure 678 break; 679 } 680 break; 681 default: 682 break; 683 } 684 // log_dbg("new state %u\n", channel->state); 685 } 686 687 688 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 689 690 // get code, signalind identifier and command len 691 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 692 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 693 uint16_t len = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 694 695 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 696 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 697 return; 698 } 699 700 // general commands without an assigned channel 701 switch(code) { 702 703 case CONNECTION_REQUEST: { 704 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 705 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 706 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 707 break; 708 } 709 710 case ECHO_REQUEST: { 711 // send back packet 712 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, len, &command[L2CAP_SIGNALING_COMMAND_DATA_OFFSET]); 713 break; 714 } 715 716 case INFORMATION_REQUEST: { 717 // we neither support connectionless L2CAP data nor support any flow control modes yet 718 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 719 if (infoType == 2) { 720 uint32_t features = 0; 721 // extended features request supported, however no features present 722 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, 4, &features); 723 } else { 724 // all other types are not supported 725 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 726 } 727 break;; 728 } 729 730 default: 731 break; 732 } 733 734 735 // Get potential destination CID 736 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 737 738 // Find channel for this sig_id and connection handle 739 linked_item_t *it; 740 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 741 l2cap_channel_t * channel = (l2cap_channel_t *) it; 742 if (channel->handle == handle) { 743 if (code & 1) { 744 // match odd commands by previous signaling identifier 745 if (channel->sig_id == sig_id) { 746 l2cap_signaling_handler_channel(channel, command); 747 break; 748 } 749 } else { 750 // match even commands by local channel id 751 if (channel->local_cid == dest_cid) { 752 l2cap_signaling_handler_channel(channel, command); 753 break; 754 } 755 } 756 } 757 } 758 } 759 760 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 761 762 // Get Channel ID 763 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 764 765 // Signaling Packet? 766 if (channel_id == 1) { 767 768 // Get Connection 769 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 770 771 uint16_t command_offset = 8; 772 while (command_offset < size) { 773 774 // handle signaling commands 775 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 776 777 // increment command_offset 778 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 779 } 780 return; 781 } 782 783 // Find channel for this channel_id and connection handle 784 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 785 if (channel) { 786 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 787 } 788 } 789 790 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 791 switch (packet_type) { 792 case HCI_EVENT_PACKET: 793 l2cap_event_handler(packet, size); 794 break; 795 case HCI_ACL_DATA_PACKET: 796 l2cap_acl_handler(packet, size); 797 break; 798 default: 799 break; 800 } 801 } 802 803 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 804 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 805 channel->state = L2CAP_STATE_CLOSED; 806 l2cap_emit_channel_closed(channel); 807 // discard channel 808 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 809 free (channel); 810 } 811 812 l2cap_service_t * l2cap_get_service(uint16_t psm){ 813 linked_item_t *it; 814 815 // close open channels 816 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 817 l2cap_service_t * service = ((l2cap_service_t *) it); 818 if ( service->psm == psm){ 819 return service; 820 }; 821 } 822 return NULL; 823 } 824 825 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 826 // check for alread registered psm // TODO: emit error event 827 l2cap_service_t *service = l2cap_get_service(psm); 828 if (service) return; 829 830 // alloc structure // TODO: emit error event 831 service = malloc(sizeof(l2cap_service_t)); 832 if (!service) return; 833 834 // fill in 835 service->psm = psm; 836 service->mtu = mtu; 837 service->connection = connection; 838 service->packet_handler = packet_handler; 839 840 // add to services list 841 linked_list_add(&l2cap_services, (linked_item_t *) service); 842 } 843 844 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 845 l2cap_service_t *service = l2cap_get_service(psm); 846 if (!service) return; 847 linked_list_remove(&l2cap_services, (linked_item_t *) service); 848 free(service); 849 } 850 851 // 852 void l2cap_close_connection(void *connection){ 853 linked_item_t *it; 854 855 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 856 l2cap_channel_t * channel; 857 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 858 channel = (l2cap_channel_t *) it; 859 if (channel->connection == connection) { 860 channel->sig_id = l2cap_next_sig_id(); 861 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 862 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 863 } 864 } 865 866 // unregister services 867 it = (linked_item_t *) &l2cap_services; 868 while (it->next) { 869 l2cap_service_t * service = (l2cap_service_t *) it->next; 870 if (service->connection == connection){ 871 it->next = it->next->next; 872 free(service); 873 } else { 874 it = it->next; 875 } 876 } 877 } 878