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