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 // offsets for L2CAP SIGNALING COMMANDS 58 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 59 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 60 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 61 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 62 63 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); 64 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size); 65 66 static uint8_t * sig_buffer = NULL; 67 static linked_list_t l2cap_channels = NULL; 68 static linked_list_t l2cap_services = NULL; 69 static uint8_t * acl_buffer = NULL; 70 static void (*packet_handler) (void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) = null_packet_handler; 71 72 static uint8_t config_options[] = { 1, 2, 150, 0}; // mtu = 48 73 74 void l2cap_init(){ 75 sig_buffer = malloc( L2CAP_MINIMAL_MTU ); 76 acl_buffer = malloc( HCI_ACL_3DH5_SIZE); 77 78 // 79 // register callback with HCI 80 // 81 hci_register_packet_handler(&l2cap_packet_handler); 82 } 83 84 85 /** Register L2CAP packet handlers */ 86 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 87 } 88 void l2cap_register_packet_handler(void (*handler)(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 89 packet_handler = handler; 90 } 91 92 // notify client/protocol handler 93 void l2cap_dispatch(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 94 if (channel->packet_handler) { 95 (* (channel->packet_handler))(type, channel->local_cid, data, size); 96 } else { 97 (*packet_handler)(channel->connection, type, channel->local_cid, data, size); 98 } 99 } 100 101 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 102 uint8_t event[17]; 103 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 104 event[1] = sizeof(event) - 2; 105 event[2] = status; 106 bt_flip_addr(&event[3], channel->address); 107 bt_store_16(event, 9, channel->handle); 108 bt_store_16(event, 11, channel->psm); 109 bt_store_16(event, 13, channel->local_cid); 110 bt_store_16(event, 15, channel->remote_cid); 111 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 112 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 113 } 114 115 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 116 uint8_t event[4]; 117 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 118 event[1] = sizeof(event) - 2; 119 bt_store_16(event, 2, channel->local_cid); 120 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 121 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 122 } 123 124 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 125 uint8_t event[16]; 126 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 127 event[1] = sizeof(event) - 2; 128 bt_flip_addr(&event[2], channel->address); 129 bt_store_16(event, 8, channel->handle); 130 bt_store_16(event, 10, channel->psm); 131 bt_store_16(event, 12, channel->local_cid); 132 bt_store_16(event, 14, channel->remote_cid); 133 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 134 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 135 } 136 137 void l2cap_emit_credits(l2cap_channel_t *channel, uint8_t credits) { 138 // first check if we should hand out credits 139 140 if (!hci_number_free_acl_slots() || hci_number_outgoing_packets(channel->handle) >= 2){ 141 return; // not yet 142 } 143 // track credits 144 channel->packets_granted += credits; 145 log_dbg("l2cap_emit_credits for cid %u, credits now: %u (+%u)\n", channel->local_cid, channel->packets_granted, credits); 146 147 uint8_t event[5]; 148 event[0] = L2CAP_EVENT_CREDITS; 149 event[1] = sizeof(event) - 2; 150 bt_store_16(event, 2, channel->local_cid); 151 event[4] = credits; 152 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 153 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 154 } 155 156 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 157 linked_item_t *it; 158 l2cap_channel_t * channel; 159 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 160 channel = (l2cap_channel_t *) it; 161 if ( channel->local_cid == local_cid) { 162 return channel; 163 } 164 } 165 return NULL; 166 } 167 168 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 169 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 170 if (channel) { 171 return channel->remote_mtu; 172 } 173 return 0; 174 } 175 176 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 177 // printf("l2cap_send_signaling_packet type %u\n", cmd); 178 va_list argptr; 179 va_start(argptr, identifier); 180 uint16_t len = l2cap_create_signaling_internal(sig_buffer, handle, cmd, identifier, argptr); 181 va_end(argptr); 182 return hci_send_acl_packet(sig_buffer, len); 183 } 184 185 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 186 187 // check for free places on BT module 188 if (!hci_number_free_acl_slots()) return -1; 189 190 int err = 0; 191 192 // find channel for local_cid, construct l2cap packet and send 193 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 194 if (channel) { 195 // track sending 196 ++channel->packets_outgoing; 197 if (channel->packets_granted > 0){ 198 --channel->packets_granted; 199 } else { 200 log_err("l2cap_send_internal cid %u, no credits!\n", local_cid); 201 } 202 log_dbg("l2cap_send_internal cid %u, 1 credit used, credits left %u; outgoing count %u\n", 203 local_cid, channel->packets_granted, channel->packets_outgoing); 204 205 // 0 - Connection handle : PB=10 : BC=00 206 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 207 // 2 - ACL length 208 bt_store_16(acl_buffer, 2, len + 4); 209 // 4 - L2CAP packet length 210 bt_store_16(acl_buffer, 4, len + 0); 211 // 6 - L2CAP channel DEST 212 bt_store_16(acl_buffer, 6, channel->remote_cid); 213 // 8 - data 214 memcpy(&acl_buffer[8], data, len); 215 216 // send 217 err = hci_send_acl_packet(acl_buffer, len+8); 218 } 219 return err; 220 } 221 222 // open outgoing L2CAP channel 223 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, bd_addr_t address, uint16_t psm){ 224 225 // alloc structure 226 l2cap_channel_t * chan = malloc(sizeof(l2cap_channel_t)); 227 // TODO: emit error event 228 if (!chan) return; 229 230 // fill in 231 BD_ADDR_COPY(chan->address, address); 232 chan->psm = psm; 233 chan->handle = 0; 234 chan->connection = connection; 235 chan->packet_handler = packet_handler; 236 chan->remote_mtu = L2CAP_MINIMAL_MTU; 237 238 // flow control 239 chan->packets_granted = 0; 240 chan->packets_outgoing = 0; 241 242 // set initial state 243 chan->state = L2CAP_STATE_CLOSED; 244 chan->sig_id = L2CAP_SIG_ID_INVALID; 245 246 // add to connections list 247 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 248 249 // send connection request 250 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 251 hci_send_cmd(&hci_create_connection, address, 0x18, 0, 0, 0, 0); 252 } 253 254 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 255 // find channel for local_cid 256 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 257 if (channel) { 258 channel->sig_id = l2cap_next_sig_id(); 259 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 260 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 261 } 262 } 263 264 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 265 linked_item_t *it; 266 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 267 l2cap_channel_t * channel = (l2cap_channel_t *) it; 268 if ( ! BD_ADDR_CMP( channel->address, address) ){ 269 if (channel->state == L2CAP_STATE_CLOSED) { 270 // failure, forward error code 271 l2cap_emit_channel_opened(channel, status); 272 // discard channel 273 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 274 free (channel); 275 } 276 } 277 } 278 } 279 280 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 281 linked_item_t *it; 282 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 283 l2cap_channel_t * channel = (l2cap_channel_t *) it; 284 if ( ! BD_ADDR_CMP( channel->address, address) ){ 285 if (channel->state == L2CAP_STATE_CLOSED) { 286 // success, start l2cap handshake 287 channel->handle = handle; 288 channel->sig_id = l2cap_next_sig_id(); 289 channel->local_cid = l2cap_next_local_cid(); 290 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 291 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->sig_id, channel->psm, channel->local_cid); 292 } 293 } 294 } 295 } 296 297 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 298 299 bd_addr_t address; 300 hci_con_handle_t handle; 301 linked_item_t *it; 302 int i; 303 304 switch(packet[0]){ 305 306 // handle connection complete events 307 case HCI_EVENT_CONNECTION_COMPLETE: 308 bt_flip_addr(address, &packet[5]); 309 if (packet[2] == 0){ 310 handle = READ_BT_16(packet, 3); 311 l2cap_handle_connection_success_for_addr(address, handle); 312 } else { 313 l2cap_handle_connection_failed_for_addr(address, packet[2]); 314 } 315 break; 316 317 // handle successful create connection cancel command 318 case HCI_EVENT_COMMAND_COMPLETE: 319 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 320 if (packet[5] == 0){ 321 bt_flip_addr(address, &packet[6]); 322 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 323 l2cap_handle_connection_failed_for_addr(address, 0x16); 324 } 325 } 326 break; 327 328 // handle disconnection complete events 329 case HCI_EVENT_DISCONNECTION_COMPLETE: 330 // send l2cap disconnect events for all channels on this handle 331 handle = READ_BT_16(packet, 3); 332 // only access next element to allows for removal 333 for (it = (linked_item_t *) &l2cap_channels; it->next ; it = it->next){ 334 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 335 if ( channel->handle == handle ){ 336 // update prev item before free'ing next element 337 it->next = it->next->next; 338 l2cap_finialize_channel_close(channel); 339 } 340 } 341 break; 342 343 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 344 for (i=0; i<packet[2];i++){ 345 handle = READ_BT_16(packet, 3 + 2*i); 346 uint16_t num_packets = READ_BT_16(packet, 3 + packet[2]*2 + 2*i); 347 while (num_packets) { 348 num_packets--; 349 // pick some slot 350 l2cap_channel_t * oldest_channel = NULL; 351 for (it = (linked_item_t *) &l2cap_channels; it->next ; it = it->next){ 352 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 353 if (channel->packets_outgoing){ 354 oldest_channel = channel; 355 } 356 } 357 // decrease packets and grant new credits 358 if (oldest_channel) { 359 oldest_channel->packets_outgoing--; 360 361 log_dbg("hci_number_completed_packet (l2cap) for cid %u, outgoing count %u\n", 362 oldest_channel->local_cid, oldest_channel->packets_outgoing); 363 364 } else { 365 log_err("hci_number_completed_packet but no outgoing packet in records\n"); 366 } 367 } 368 } 369 break; 370 371 // HCI Connection Timeouts 372 case L2CAP_EVENT_TIMEOUT_CHECK: 373 handle = READ_BT_16(packet, 2); 374 l2cap_channel_t * channel; 375 int used = 0; 376 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 377 channel = (l2cap_channel_t *) it; 378 if (channel->handle == handle) { 379 used = 1; 380 } 381 } 382 if (!used) { 383 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 384 } 385 break; 386 387 default: 388 break; 389 } 390 391 // pass on 392 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 393 } 394 395 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 396 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, identifier, channel->local_cid, channel->remote_cid); 397 l2cap_finialize_channel_close(channel); 398 } 399 400 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 401 402 // printf("l2cap_handle_connection_request for handle %u, psm %u cid %u\n", handle, psm, source_cid); 403 l2cap_service_t *service = l2cap_get_service(psm); 404 if (!service) { 405 // 0x0002 PSM not supported 406 // printf("l2cap_handle_connection_request no PSM for psm %u/n", psm); 407 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, 0x0002, 0); 408 return; 409 } 410 411 hci_connection_t * hci_connection = connection_for_handle( handle ); 412 if (!hci_connection) { 413 fprintf(stderr, "no hci_connection for handle %u\n", handle); 414 // TODO: emit error 415 return; 416 } 417 // alloc structure 418 // printf("l2cap_handle_connection_request register channel\n"); 419 l2cap_channel_t * channel = malloc(sizeof(l2cap_channel_t)); 420 // TODO: emit error event 421 if (!channel) return; 422 423 // fill in 424 BD_ADDR_COPY(channel->address, hci_connection->address); 425 channel->psm = psm; 426 channel->handle = handle; 427 channel->connection = service->connection; 428 channel->packet_handler = service->packet_handler; 429 channel->local_cid = l2cap_next_local_cid(); 430 channel->remote_cid = source_cid; 431 channel->remote_mtu = L2CAP_MINIMAL_MTU; 432 433 // set initial state 434 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 435 436 // temp. store req sig id 437 channel->sig_id = sig_id; 438 439 // add to connections list 440 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 441 442 // emit incoming connection request 443 l2cap_emit_connection_request(channel); 444 } 445 446 void l2cap_accept_connection_internal(uint16_t local_cid){ 447 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 448 if (!channel) { 449 fprintf(stderr, "l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 450 return; 451 } 452 453 // accept connection 454 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, channel->local_cid, channel->remote_cid, 0, 0); 455 456 // set real sig and state and start config 457 channel->sig_id = l2cap_next_sig_id(); 458 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 459 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 460 461 // printf("new state %u\n", channel->state); 462 } 463 464 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 465 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 466 if (!channel) { 467 fprintf(stderr, "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 468 return; 469 } 470 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, 0, 0, reason, 0); 471 472 // discard channel 473 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 474 free (channel); 475 } 476 477 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 478 // accept the other's configuration options 479 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 480 uint16_t pos = 8; 481 while (pos < end_pos){ 482 uint8_t type = command[pos++]; 483 uint8_t length = command[pos++]; 484 // MTU { type(8): 1, len(8):2, MTU(16) } 485 if ((type & 0x7f) == 1 && length == 2){ 486 channel->remote_mtu = READ_BT_16(command, pos); 487 // printf("l2cap cid %u, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 488 } 489 pos += length; 490 } 491 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 492 // send back received options 493 // l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->remote_cid, 0, 0, len-4, &command[8]); 494 // send back OK 495 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->remote_cid, 0, 0, 0, NULL); 496 } 497 498 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 499 500 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 501 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 502 uint16_t result = 0; 503 504 // printf("signaling handler code %u\n", code); 505 506 switch (channel->state) { 507 508 case L2CAP_STATE_WAIT_CONNECT_RSP: 509 switch (code){ 510 case CONNECTION_RESPONSE: 511 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 512 switch (result) { 513 case 0: 514 // successful connection 515 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 516 channel->sig_id = l2cap_next_sig_id(); 517 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 518 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 519 break; 520 case 1: 521 // connection pending. get some coffee 522 break; 523 default: 524 // map l2cap connection response result to BTstack status enumeration 525 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 526 break; 527 } 528 break; 529 530 case DISCONNECTION_REQUEST: 531 l2cap_handle_disconnect_request(channel, identifier); 532 break; 533 534 default: 535 //@TODO: implement other signaling packets 536 break; 537 } 538 break; 539 540 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ: 541 switch (code) { 542 case CONFIGURE_RESPONSE: 543 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ; 544 break; 545 case CONFIGURE_REQUEST: 546 l2cap_signaling_handle_configure_request(channel, command); 547 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP; 548 break; 549 case DISCONNECTION_REQUEST: 550 l2cap_handle_disconnect_request(channel, identifier); 551 break; 552 default: 553 //@TODO: implement other signaling packets 554 break; 555 } 556 break; 557 558 case L2CAP_STATE_WAIT_CONFIG_REQ: 559 switch (code) { 560 case CONFIGURE_REQUEST: 561 l2cap_signaling_handle_configure_request(channel, command); 562 channel->state = L2CAP_STATE_OPEN; 563 l2cap_emit_channel_opened(channel, 0); // success 564 l2cap_emit_credits(channel, 1); 565 break; 566 case DISCONNECTION_REQUEST: 567 l2cap_handle_disconnect_request(channel, identifier); 568 break; 569 default: 570 //@TODO: implement other signaling packets 571 break; 572 } 573 break; 574 575 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP: 576 switch (code) { 577 case CONFIGURE_RESPONSE: 578 channel->state = L2CAP_STATE_OPEN; 579 l2cap_emit_channel_opened(channel, 0); // success 580 l2cap_emit_credits(channel, 1); 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_DISCONNECT: 592 switch (code) { 593 case DISCONNECTION_RESPONSE: 594 l2cap_finialize_channel_close(channel); 595 break; 596 case DISCONNECTION_REQUEST: 597 l2cap_handle_disconnect_request(channel, identifier); 598 break; 599 default: 600 //@TODO: implement other signaling packets 601 break; 602 } 603 break; 604 605 case L2CAP_STATE_CLOSED: 606 // @TODO handle incoming requests 607 break; 608 609 case L2CAP_STATE_OPEN: 610 switch (code) { 611 case DISCONNECTION_REQUEST: 612 l2cap_handle_disconnect_request(channel, identifier); 613 break; 614 default: 615 //@TODO: implement other signaling packets, e.g. re-configure 616 break; 617 } 618 break; 619 default: 620 break; 621 } 622 // printf("new state %u\n", channel->state); 623 } 624 625 626 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 627 628 // get code, signalind identifier and command len 629 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 630 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 631 uint16_t len = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 632 633 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 634 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 635 return; 636 } 637 638 // general commands without an assigned channel 639 switch(code) { 640 641 case CONNECTION_REQUEST: { 642 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 643 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 644 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 645 break; 646 } 647 648 case ECHO_REQUEST: { 649 // send back packet 650 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, len, &command[L2CAP_SIGNALING_COMMAND_DATA_OFFSET]); 651 break; 652 } 653 654 case INFORMATION_REQUEST: { 655 // we neither support connectionless L2CAP data nor support any flow control modes yet 656 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 657 if (infoType == 2) { 658 uint32_t features = 0; 659 // extended features request supported, however no features present 660 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, 4, &features); 661 } else { 662 // all other types are not supported 663 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 664 } 665 break;; 666 } 667 668 default: 669 break; 670 } 671 672 673 // Get potential destination CID 674 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 675 676 // Find channel for this sig_id and connection handle 677 linked_item_t *it; 678 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 679 l2cap_channel_t * channel = (l2cap_channel_t *) it; 680 if (channel->handle == handle) { 681 if (code & 1) { 682 // match odd commands by previous signaling identifier 683 if (channel->sig_id == sig_id) { 684 l2cap_signaling_handler_channel(channel, command); 685 } 686 } else { 687 // match even commands by local channel id 688 if (channel->local_cid == dest_cid) { 689 l2cap_signaling_handler_channel(channel, command); 690 } 691 } 692 } 693 } 694 } 695 696 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 697 698 // Get Channel ID 699 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 700 701 // Signaling Packet? 702 if (channel_id == 1) { 703 704 // Get Connection 705 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 706 707 uint16_t command_offset = 8; 708 while (command_offset < size) { 709 710 // handle signaling commands 711 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 712 713 // increment command_offset 714 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 715 } 716 return; 717 } 718 719 // Find channel for this channel_id and connection handle 720 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 721 if (channel) { 722 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 723 } 724 } 725 726 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 727 switch (packet_type) { 728 case HCI_EVENT_PACKET: 729 l2cap_event_handler(packet, size); 730 break; 731 case HCI_ACL_DATA_PACKET: 732 l2cap_acl_handler(packet, size); 733 break; 734 default: 735 break; 736 } 737 } 738 739 // finalize closed channel 740 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 741 channel->state = L2CAP_STATE_CLOSED; 742 l2cap_emit_channel_closed(channel); 743 744 // discard channel 745 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 746 free (channel); 747 } 748 749 l2cap_service_t * l2cap_get_service(uint16_t psm){ 750 linked_item_t *it; 751 752 // close open channels 753 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 754 l2cap_service_t * service = ((l2cap_service_t *) it); 755 if ( service->psm == psm){ 756 return service; 757 }; 758 } 759 return NULL; 760 } 761 762 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 763 // check for alread registered psm // TODO: emit error event 764 l2cap_service_t *service = l2cap_get_service(psm); 765 if (service) return; 766 767 // alloc structure // TODO: emit error event 768 service = malloc(sizeof(l2cap_service_t)); 769 if (!service) return; 770 771 // fill in 772 service->psm = psm; 773 service->mtu = mtu; 774 service->connection = connection; 775 service->packet_handler = packet_handler; 776 777 // add to services list 778 linked_list_add(&l2cap_services, (linked_item_t *) service); 779 } 780 781 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 782 l2cap_service_t *service = l2cap_get_service(psm); 783 if (!service) return; 784 linked_list_remove(&l2cap_services, (linked_item_t *) service); 785 free(service); 786 } 787 788 // 789 void l2cap_close_connection(void *connection){ 790 linked_item_t *it; 791 792 // close open channels 793 l2cap_channel_t * channel; 794 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 795 channel = (l2cap_channel_t *) it; 796 if (channel->connection == connection) { 797 channel->sig_id = l2cap_next_sig_id(); 798 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 799 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 800 } 801 } 802 803 // unregister services 804 it = (linked_item_t *) &l2cap_services; 805 while (it->next){ 806 l2cap_service_t * service = (l2cap_service_t *) it->next; 807 if (service->connection == connection){ 808 it->next = it->next->next; 809 free(service); 810 } else { 811 it = it->next; 812 } 813 } 814 } 815