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