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 // track credits 139 channel->packets_granted += credits; 140 log_dbg("l2cap_emit_credits for cid %u, credits now: %u (+%u)\n", channel->local_cid, channel->packets_granted, credits); 141 142 uint8_t event[5]; 143 event[0] = L2CAP_EVENT_CREDITS; 144 event[1] = sizeof(event) - 2; 145 bt_store_16(event, 2, channel->local_cid); 146 event[4] = credits; 147 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 148 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 149 } 150 151 void l2cap_hand_out_credits(){ 152 linked_item_t *it; 153 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 154 if (!hci_number_free_acl_slots()) return; 155 l2cap_channel_t * channel = (l2cap_channel_t *) it; 156 if (channel->state != L2CAP_STATE_OPEN) continue; 157 if (hci_number_outgoing_packets(channel->handle) < 2 && channel->packets_granted == 0) { 158 l2cap_emit_credits(channel, 1); 159 } 160 } 161 } 162 163 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 164 linked_item_t *it; 165 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 166 l2cap_channel_t * channel = (l2cap_channel_t *) it; 167 if ( channel->local_cid == local_cid) { 168 return channel; 169 } 170 } 171 return NULL; 172 } 173 174 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 175 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 176 if (channel) { 177 return channel->remote_mtu; 178 } 179 return 0; 180 } 181 182 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 183 // printf("l2cap_send_signaling_packet type %u\n", cmd); 184 va_list argptr; 185 va_start(argptr, identifier); 186 uint16_t len = l2cap_create_signaling_internal(sig_buffer, handle, cmd, identifier, argptr); 187 va_end(argptr); 188 return hci_send_acl_packet(sig_buffer, len); 189 } 190 191 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 192 193 // check for free places on BT module 194 if (!hci_number_free_acl_slots()) { 195 log_dbg("l2cap_send_internal cid %u, BT module full <-----\n", local_cid); 196 return -1; 197 } 198 int err = 0; 199 200 // find channel for local_cid, construct l2cap packet and send 201 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 202 if (channel) { 203 // track sending 204 ++channel->packets_outgoing; 205 if (channel->packets_granted > 0){ 206 --channel->packets_granted; 207 // log_dbg("l2cap_send_internal cid %u, 1 credit used, credits left %u; outgoing count %u\n", 208 // local_cid, channel->packets_granted, channel->packets_outgoing); 209 } else { 210 log_err("l2cap_send_internal cid %u, no credits!\n", local_cid); 211 } 212 213 // 0 - Connection handle : PB=10 : BC=00 214 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 215 // 2 - ACL length 216 bt_store_16(acl_buffer, 2, len + 4); 217 // 4 - L2CAP packet length 218 bt_store_16(acl_buffer, 4, len + 0); 219 // 6 - L2CAP channel DEST 220 bt_store_16(acl_buffer, 6, channel->remote_cid); 221 // 8 - data 222 memcpy(&acl_buffer[8], data, len); 223 224 // send 225 err = hci_send_acl_packet(acl_buffer, len+8); 226 } 227 return err; 228 } 229 230 // open outgoing L2CAP channel 231 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, bd_addr_t address, uint16_t psm){ 232 233 // alloc structure 234 l2cap_channel_t * chan = malloc(sizeof(l2cap_channel_t)); 235 // TODO: emit error event 236 if (!chan) return; 237 238 // fill in 239 BD_ADDR_COPY(chan->address, address); 240 chan->psm = psm; 241 chan->handle = 0; 242 chan->connection = connection; 243 chan->packet_handler = packet_handler; 244 chan->remote_mtu = L2CAP_MINIMAL_MTU; 245 246 // flow control 247 chan->packets_granted = 0; 248 chan->packets_outgoing = 0; 249 250 // set initial state 251 chan->state = L2CAP_STATE_CLOSED; 252 chan->sig_id = L2CAP_SIG_ID_INVALID; 253 254 // add to connections list 255 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 256 257 // send connection request 258 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 259 hci_send_cmd(&hci_create_connection, address, 0x18, 0, 0, 0, 0); 260 } 261 262 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 263 // find channel for local_cid 264 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 265 if (channel) { 266 channel->sig_id = l2cap_next_sig_id(); 267 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 268 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 269 } 270 } 271 272 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 273 linked_item_t *it; 274 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 275 l2cap_channel_t * channel = (l2cap_channel_t *) it; 276 if ( ! BD_ADDR_CMP( channel->address, address) ){ 277 if (channel->state == L2CAP_STATE_CLOSED) { 278 // failure, forward error code 279 l2cap_emit_channel_opened(channel, status); 280 // discard channel 281 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 282 free (channel); 283 } 284 } 285 } 286 } 287 288 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 289 linked_item_t *it; 290 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 291 l2cap_channel_t * channel = (l2cap_channel_t *) it; 292 if ( ! BD_ADDR_CMP( channel->address, address) ){ 293 if (channel->state == L2CAP_STATE_CLOSED) { 294 // success, start l2cap handshake 295 channel->handle = handle; 296 channel->sig_id = l2cap_next_sig_id(); 297 channel->local_cid = l2cap_next_local_cid(); 298 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 299 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->sig_id, channel->psm, channel->local_cid); 300 } 301 } 302 } 303 } 304 305 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 306 307 bd_addr_t address; 308 hci_con_handle_t handle; 309 linked_item_t *it; 310 int i; 311 312 switch(packet[0]){ 313 314 // handle connection complete events 315 case HCI_EVENT_CONNECTION_COMPLETE: 316 bt_flip_addr(address, &packet[5]); 317 if (packet[2] == 0){ 318 handle = READ_BT_16(packet, 3); 319 l2cap_handle_connection_success_for_addr(address, handle); 320 } else { 321 l2cap_handle_connection_failed_for_addr(address, packet[2]); 322 } 323 break; 324 325 // handle successful create connection cancel command 326 case HCI_EVENT_COMMAND_COMPLETE: 327 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 328 if (packet[5] == 0){ 329 bt_flip_addr(address, &packet[6]); 330 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 331 l2cap_handle_connection_failed_for_addr(address, 0x16); 332 } 333 } 334 break; 335 336 // handle disconnection complete events 337 case HCI_EVENT_DISCONNECTION_COMPLETE: 338 // send l2cap disconnect events for all channels on this handle 339 handle = READ_BT_16(packet, 3); 340 // only access next element to allows for removal 341 for (it = (linked_item_t *) &l2cap_channels; it->next ; it = it->next){ 342 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 343 if ( channel->handle == handle ){ 344 // update prev item before free'ing next element 345 it->next = it->next->next; 346 l2cap_finialize_channel_close(channel); 347 } 348 } 349 break; 350 351 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 352 for (i=0; i<packet[2];i++){ 353 handle = READ_BT_16(packet, 3 + 2*i); 354 uint16_t num_packets = READ_BT_16(packet, 3 + packet[2]*2 + 2*i); 355 while (num_packets) { 356 357 // find channels with max nr of pending outgoing packets 358 l2cap_channel_t * fullest_channel = NULL; 359 int max_nr_pending = 0; 360 for (it = (linked_item_t *) &l2cap_channels; it->next ; it = it->next){ 361 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 362 if (channel->packets_outgoing > max_nr_pending){ 363 fullest_channel = channel; 364 max_nr_pending = channel->packets_outgoing; 365 } 366 } 367 368 // decrease packets 369 if (fullest_channel) { 370 fullest_channel->packets_outgoing--; 371 // log_dbg("hci_number_completed_packet (l2cap) for cid %u, outgoing count %u\n", 372 // fullest_channel->local_cid, fullest_channel->packets_outgoing); 373 } else { 374 log_err("hci_number_completed_packet but no outgoing packet in records\n"); 375 } 376 377 // handled! 378 num_packets--; 379 } 380 } 381 l2cap_hand_out_credits(); 382 break; 383 384 // HCI Connection Timeouts 385 case L2CAP_EVENT_TIMEOUT_CHECK: 386 handle = READ_BT_16(packet, 2); 387 l2cap_channel_t * channel; 388 int used = 0; 389 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 390 channel = (l2cap_channel_t *) it; 391 if (channel->handle == handle) { 392 used = 1; 393 } 394 } 395 if (!used) { 396 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 397 } 398 break; 399 400 default: 401 break; 402 } 403 404 // pass on 405 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 406 } 407 408 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 409 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, identifier, channel->local_cid, channel->remote_cid); 410 l2cap_finialize_channel_close(channel); 411 } 412 413 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 414 415 // printf("l2cap_handle_connection_request for handle %u, psm %u cid %u\n", handle, psm, source_cid); 416 l2cap_service_t *service = l2cap_get_service(psm); 417 if (!service) { 418 // 0x0002 PSM not supported 419 // printf("l2cap_handle_connection_request no PSM for psm %u/n", psm); 420 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, 0x0002, 0); 421 return; 422 } 423 424 hci_connection_t * hci_connection = connection_for_handle( handle ); 425 if (!hci_connection) { 426 fprintf(stderr, "no hci_connection for handle %u\n", handle); 427 // TODO: emit error 428 return; 429 } 430 // alloc structure 431 // printf("l2cap_handle_connection_request register channel\n"); 432 l2cap_channel_t * channel = malloc(sizeof(l2cap_channel_t)); 433 // TODO: emit error event 434 if (!channel) return; 435 436 // fill in 437 BD_ADDR_COPY(channel->address, hci_connection->address); 438 channel->psm = psm; 439 channel->handle = handle; 440 channel->connection = service->connection; 441 channel->packet_handler = service->packet_handler; 442 channel->local_cid = l2cap_next_local_cid(); 443 channel->remote_cid = source_cid; 444 channel->remote_mtu = L2CAP_MINIMAL_MTU; 445 446 // set initial state 447 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 448 449 // temp. store req sig id 450 channel->sig_id = sig_id; 451 452 // add to connections list 453 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 454 455 // emit incoming connection request 456 l2cap_emit_connection_request(channel); 457 } 458 459 void l2cap_accept_connection_internal(uint16_t local_cid){ 460 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 461 if (!channel) { 462 fprintf(stderr, "l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 463 return; 464 } 465 466 // accept connection 467 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, channel->local_cid, channel->remote_cid, 0, 0); 468 469 // set real sig and state and start config 470 channel->sig_id = l2cap_next_sig_id(); 471 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 472 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 473 474 // printf("new state %u\n", channel->state); 475 } 476 477 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 478 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 479 if (!channel) { 480 fprintf(stderr, "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 481 return; 482 } 483 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, 0, 0, reason, 0); 484 485 // discard channel 486 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 487 free (channel); 488 } 489 490 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 491 // accept the other's configuration options 492 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 493 uint16_t pos = 8; 494 while (pos < end_pos){ 495 uint8_t type = command[pos++]; 496 uint8_t length = command[pos++]; 497 // MTU { type(8): 1, len(8):2, MTU(16) } 498 if ((type & 0x7f) == 1 && length == 2){ 499 channel->remote_mtu = READ_BT_16(command, pos); 500 // printf("l2cap cid %u, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 501 } 502 pos += length; 503 } 504 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 505 // send back received options 506 // l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->remote_cid, 0, 0, len-4, &command[8]); 507 // send back OK 508 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->remote_cid, 0, 0, 0, NULL); 509 } 510 511 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 512 513 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 514 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 515 uint16_t result = 0; 516 517 // printf("signaling handler code %u\n", code); 518 519 switch (channel->state) { 520 521 case L2CAP_STATE_WAIT_CONNECT_RSP: 522 switch (code){ 523 case CONNECTION_RESPONSE: 524 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 525 switch (result) { 526 case 0: 527 // successful connection 528 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 529 channel->sig_id = l2cap_next_sig_id(); 530 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 531 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 532 break; 533 case 1: 534 // connection pending. get some coffee 535 break; 536 default: 537 // map l2cap connection response result to BTstack status enumeration 538 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 539 break; 540 } 541 break; 542 543 case DISCONNECTION_REQUEST: 544 l2cap_handle_disconnect_request(channel, identifier); 545 break; 546 547 default: 548 //@TODO: implement other signaling packets 549 break; 550 } 551 break; 552 553 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ: 554 switch (code) { 555 case CONFIGURE_RESPONSE: 556 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ; 557 break; 558 case CONFIGURE_REQUEST: 559 l2cap_signaling_handle_configure_request(channel, command); 560 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP; 561 break; 562 case DISCONNECTION_REQUEST: 563 l2cap_handle_disconnect_request(channel, identifier); 564 break; 565 default: 566 //@TODO: implement other signaling packets 567 break; 568 } 569 break; 570 571 case L2CAP_STATE_WAIT_CONFIG_REQ: 572 switch (code) { 573 case CONFIGURE_REQUEST: 574 l2cap_signaling_handle_configure_request(channel, command); 575 channel->state = L2CAP_STATE_OPEN; 576 l2cap_emit_channel_opened(channel, 0); // success 577 l2cap_emit_credits(channel, 1); 578 break; 579 case DISCONNECTION_REQUEST: 580 l2cap_handle_disconnect_request(channel, identifier); 581 break; 582 default: 583 //@TODO: implement other signaling packets 584 break; 585 } 586 break; 587 588 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP: 589 switch (code) { 590 case CONFIGURE_RESPONSE: 591 channel->state = L2CAP_STATE_OPEN; 592 l2cap_emit_channel_opened(channel, 0); // success 593 l2cap_emit_credits(channel, 1); 594 break; 595 case DISCONNECTION_REQUEST: 596 l2cap_handle_disconnect_request(channel, identifier); 597 break; 598 default: 599 //@TODO: implement other signaling packets 600 break; 601 } 602 break; 603 604 case L2CAP_STATE_WAIT_DISCONNECT: 605 switch (code) { 606 case DISCONNECTION_RESPONSE: 607 l2cap_finialize_channel_close(channel); 608 break; 609 case DISCONNECTION_REQUEST: 610 l2cap_handle_disconnect_request(channel, identifier); 611 break; 612 default: 613 //@TODO: implement other signaling packets 614 break; 615 } 616 break; 617 618 case L2CAP_STATE_CLOSED: 619 // @TODO handle incoming requests 620 break; 621 622 case L2CAP_STATE_OPEN: 623 switch (code) { 624 case DISCONNECTION_REQUEST: 625 l2cap_handle_disconnect_request(channel, identifier); 626 break; 627 default: 628 //@TODO: implement other signaling packets, e.g. re-configure 629 break; 630 } 631 break; 632 default: 633 break; 634 } 635 // printf("new state %u\n", channel->state); 636 } 637 638 639 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 640 641 // get code, signalind identifier and command len 642 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 643 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 644 uint16_t len = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 645 646 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 647 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 648 return; 649 } 650 651 // general commands without an assigned channel 652 switch(code) { 653 654 case CONNECTION_REQUEST: { 655 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 656 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 657 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 658 break; 659 } 660 661 case ECHO_REQUEST: { 662 // send back packet 663 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, len, &command[L2CAP_SIGNALING_COMMAND_DATA_OFFSET]); 664 break; 665 } 666 667 case INFORMATION_REQUEST: { 668 // we neither support connectionless L2CAP data nor support any flow control modes yet 669 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 670 if (infoType == 2) { 671 uint32_t features = 0; 672 // extended features request supported, however no features present 673 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, 4, &features); 674 } else { 675 // all other types are not supported 676 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 677 } 678 break;; 679 } 680 681 default: 682 break; 683 } 684 685 686 // Get potential destination CID 687 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 688 689 // Find channel for this sig_id and connection handle 690 linked_item_t *it; 691 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 692 l2cap_channel_t * channel = (l2cap_channel_t *) it; 693 if (channel->handle == handle) { 694 if (code & 1) { 695 // match odd commands by previous signaling identifier 696 if (channel->sig_id == sig_id) { 697 l2cap_signaling_handler_channel(channel, command); 698 } 699 } else { 700 // match even commands by local channel id 701 if (channel->local_cid == dest_cid) { 702 l2cap_signaling_handler_channel(channel, command); 703 } 704 } 705 } 706 } 707 } 708 709 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 710 711 // Get Channel ID 712 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 713 714 // Signaling Packet? 715 if (channel_id == 1) { 716 717 // Get Connection 718 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 719 720 uint16_t command_offset = 8; 721 while (command_offset < size) { 722 723 // handle signaling commands 724 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 725 726 // increment command_offset 727 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 728 } 729 return; 730 } 731 732 // Find channel for this channel_id and connection handle 733 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 734 if (channel) { 735 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 736 } 737 } 738 739 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 740 switch (packet_type) { 741 case HCI_EVENT_PACKET: 742 l2cap_event_handler(packet, size); 743 break; 744 case HCI_ACL_DATA_PACKET: 745 l2cap_acl_handler(packet, size); 746 break; 747 default: 748 break; 749 } 750 } 751 752 // finalize closed channel 753 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 754 channel->state = L2CAP_STATE_CLOSED; 755 l2cap_emit_channel_closed(channel); 756 757 // discard channel 758 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 759 free (channel); 760 } 761 762 l2cap_service_t * l2cap_get_service(uint16_t psm){ 763 linked_item_t *it; 764 765 // close open channels 766 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 767 l2cap_service_t * service = ((l2cap_service_t *) it); 768 if ( service->psm == psm){ 769 return service; 770 }; 771 } 772 return NULL; 773 } 774 775 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 776 // check for alread registered psm // TODO: emit error event 777 l2cap_service_t *service = l2cap_get_service(psm); 778 if (service) return; 779 780 // alloc structure // TODO: emit error event 781 service = malloc(sizeof(l2cap_service_t)); 782 if (!service) return; 783 784 // fill in 785 service->psm = psm; 786 service->mtu = mtu; 787 service->connection = connection; 788 service->packet_handler = packet_handler; 789 790 // add to services list 791 linked_list_add(&l2cap_services, (linked_item_t *) service); 792 } 793 794 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 795 l2cap_service_t *service = l2cap_get_service(psm); 796 if (!service) return; 797 linked_list_remove(&l2cap_services, (linked_item_t *) service); 798 free(service); 799 } 800 801 // 802 void l2cap_close_connection(void *connection){ 803 linked_item_t *it; 804 805 // close open channels 806 l2cap_channel_t * channel; 807 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 808 channel = (l2cap_channel_t *) it; 809 if (channel->connection == connection) { 810 channel->sig_id = l2cap_next_sig_id(); 811 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 812 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 813 } 814 } 815 816 // unregister services 817 it = (linked_item_t *) &l2cap_services; 818 while (it->next){ 819 l2cap_service_t * service = (l2cap_service_t *) it->next; 820 if (service->connection == connection){ 821 it->next = it->next->next; 822 free(service); 823 } else { 824 it = it->next; 825 } 826 } 827 } 828