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 void l2cap_init(){ 73 sig_buffer = malloc( L2CAP_MINIMAL_MTU ); 74 acl_buffer = malloc( HCI_ACL_3DH5_SIZE); 75 76 // 77 // register callback with HCI 78 // 79 hci_register_packet_handler(&l2cap_packet_handler); 80 } 81 82 83 /** Register L2CAP packet handlers */ 84 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 85 } 86 void l2cap_register_packet_handler(void (*handler)(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 87 packet_handler = handler; 88 } 89 90 // notify client/protocol handler 91 void l2cap_dispatch(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 92 if (channel->packet_handler) { 93 (* (channel->packet_handler))(type, channel->local_cid, data, size); 94 } else { 95 (*packet_handler)(channel->connection, type, channel->local_cid, data, size); 96 } 97 } 98 99 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 100 uint8_t event[17]; 101 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 102 event[1] = sizeof(event) - 2; 103 event[2] = status; 104 bt_flip_addr(&event[3], channel->address); 105 bt_store_16(event, 9, channel->handle); 106 bt_store_16(event, 11, channel->psm); 107 bt_store_16(event, 13, channel->local_cid); 108 bt_store_16(event, 15, channel->remote_cid); 109 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 110 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 111 } 112 113 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 114 uint8_t event[4]; 115 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 116 event[1] = sizeof(event) - 2; 117 bt_store_16(event, 2, channel->local_cid); 118 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 119 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 120 } 121 122 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 123 uint8_t event[16]; 124 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 125 event[1] = sizeof(event) - 2; 126 bt_flip_addr(&event[2], channel->address); 127 bt_store_16(event, 8, channel->handle); 128 bt_store_16(event, 10, channel->psm); 129 bt_store_16(event, 12, channel->local_cid); 130 bt_store_16(event, 14, channel->remote_cid); 131 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 132 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 133 } 134 135 void l2cap_emit_credits(l2cap_channel_t *channel, uint8_t credits) { 136 // track credits 137 channel->packets_granted += credits; 138 // log_dbg("l2cap_emit_credits for cid %u, credits now: %u (+%u)\n", channel->local_cid, channel->packets_granted, credits); 139 140 uint8_t event[5]; 141 event[0] = L2CAP_EVENT_CREDITS; 142 event[1] = sizeof(event) - 2; 143 bt_store_16(event, 2, channel->local_cid); 144 event[4] = credits; 145 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 146 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 147 } 148 149 void l2cap_hand_out_credits(){ 150 linked_item_t *it; 151 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 152 if (!hci_number_free_acl_slots()) return; 153 l2cap_channel_t * channel = (l2cap_channel_t *) it; 154 if (channel->state != L2CAP_STATE_OPEN) continue; 155 if (hci_number_outgoing_packets(channel->handle) < 2 && channel->packets_granted == 0) { 156 l2cap_emit_credits(channel, 1); 157 } 158 } 159 } 160 161 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 162 linked_item_t *it; 163 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 164 l2cap_channel_t * channel = (l2cap_channel_t *) it; 165 if ( channel->local_cid == local_cid) { 166 return channel; 167 } 168 } 169 return NULL; 170 } 171 172 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 173 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 174 if (channel) { 175 return channel->remote_mtu; 176 } 177 return 0; 178 } 179 180 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 181 // log_dbg("l2cap_send_signaling_packet type %u\n", cmd); 182 va_list argptr; 183 va_start(argptr, identifier); 184 uint16_t len = l2cap_create_signaling_internal(sig_buffer, handle, cmd, identifier, argptr); 185 va_end(argptr); 186 return hci_send_acl_packet(sig_buffer, len); 187 } 188 189 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 190 191 // check for free places on BT module 192 if (!hci_number_free_acl_slots()) { 193 log_dbg("l2cap_send_internal cid %u, BT module full <-----\n", local_cid); 194 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 // log_dbg("l2cap_send_internal cid %u, 1 credit used, credits left %u; outgoing count %u\n", 206 // local_cid, channel->packets_granted, channel->packets_outgoing); 207 } else { 208 log_err("l2cap_send_internal cid %u, no credits!\n", local_cid); 209 } 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 } 225 226 l2cap_hand_out_credits(); 227 228 return err; 229 } 230 231 // open outgoing L2CAP channel 232 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 233 bd_addr_t address, uint16_t psm, uint16_t mtu){ 234 235 // alloc structure 236 l2cap_channel_t * chan = malloc(sizeof(l2cap_channel_t)); 237 // TODO: emit error event 238 if (!chan) return; 239 240 // fill in 241 BD_ADDR_COPY(chan->address, address); 242 chan->psm = psm; 243 chan->handle = 0; 244 chan->connection = connection; 245 chan->packet_handler = packet_handler; 246 chan->remote_mtu = L2CAP_MINIMAL_MTU; 247 chan->local_mtu = mtu; 248 249 // flow control 250 chan->packets_granted = 0; 251 chan->packets_outgoing = 0; 252 253 // set initial state 254 chan->state = L2CAP_STATE_CLOSED; 255 chan->sig_id = L2CAP_SIG_ID_INVALID; 256 257 // add to connections list 258 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 259 260 // send connection request 261 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 262 hci_send_cmd(&hci_create_connection, address, 0x18, 0, 0, 0, 0); 263 } 264 265 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 266 // find channel for local_cid 267 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 268 if (channel) { 269 channel->sig_id = l2cap_next_sig_id(); 270 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 271 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 272 } 273 } 274 275 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 276 linked_item_t *it; 277 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 278 l2cap_channel_t * channel = (l2cap_channel_t *) it; 279 if ( ! BD_ADDR_CMP( channel->address, address) ){ 280 if (channel->state == L2CAP_STATE_CLOSED) { 281 // failure, forward error code 282 l2cap_emit_channel_opened(channel, status); 283 // discard channel 284 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 285 free (channel); 286 } 287 } 288 } 289 } 290 291 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 292 linked_item_t *it; 293 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 294 l2cap_channel_t * channel = (l2cap_channel_t *) it; 295 if ( ! BD_ADDR_CMP( channel->address, address) ){ 296 if (channel->state == L2CAP_STATE_CLOSED) { 297 // success, start l2cap handshake 298 channel->handle = handle; 299 channel->sig_id = l2cap_next_sig_id(); 300 channel->local_cid = l2cap_next_local_cid(); 301 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 302 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->sig_id, channel->psm, channel->local_cid); 303 } 304 } 305 } 306 } 307 308 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 309 310 bd_addr_t address; 311 hci_con_handle_t handle; 312 linked_item_t *it; 313 int i; 314 315 switch(packet[0]){ 316 317 // handle connection complete events 318 case HCI_EVENT_CONNECTION_COMPLETE: 319 bt_flip_addr(address, &packet[5]); 320 if (packet[2] == 0){ 321 handle = READ_BT_16(packet, 3); 322 l2cap_handle_connection_success_for_addr(address, handle); 323 } else { 324 l2cap_handle_connection_failed_for_addr(address, packet[2]); 325 } 326 break; 327 328 // handle successful create connection cancel command 329 case HCI_EVENT_COMMAND_COMPLETE: 330 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 331 if (packet[5] == 0){ 332 bt_flip_addr(address, &packet[6]); 333 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 334 l2cap_handle_connection_failed_for_addr(address, 0x16); 335 } 336 } 337 break; 338 339 // handle disconnection complete events 340 case HCI_EVENT_DISCONNECTION_COMPLETE: 341 // send l2cap disconnect events for all channels on this handle 342 handle = READ_BT_16(packet, 3); 343 // only access next element to allows for removal 344 for (it = (linked_item_t *) &l2cap_channels; it->next ; it = it->next){ 345 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 346 if ( channel->handle == handle ){ 347 // update prev item before free'ing next element 348 it->next = it->next->next; 349 l2cap_finialize_channel_close(channel); 350 } 351 } 352 break; 353 354 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 355 for (i=0; i<packet[2];i++){ 356 handle = READ_BT_16(packet, 3 + 2*i); 357 uint16_t num_packets = READ_BT_16(packet, 3 + packet[2]*2 + 2*i); 358 while (num_packets) { 359 360 // find channels with max nr of pending outgoing packets 361 l2cap_channel_t * fullest_channel = NULL; 362 int max_nr_pending = 0; 363 for (it = (linked_item_t *) &l2cap_channels; it->next ; it = it->next){ 364 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 365 if (channel->packets_outgoing > max_nr_pending){ 366 fullest_channel = channel; 367 max_nr_pending = channel->packets_outgoing; 368 } 369 } 370 371 // decrease packets 372 if (fullest_channel) { 373 fullest_channel->packets_outgoing--; 374 // log_dbg("hci_number_completed_packet (l2cap) for cid %u, outgoing count %u\n", 375 // fullest_channel->local_cid, fullest_channel->packets_outgoing); 376 } else { 377 log_err("hci_number_completed_packet but no outgoing packet in records\n"); 378 } 379 380 // handled! 381 num_packets--; 382 } 383 } 384 l2cap_hand_out_credits(); 385 break; 386 387 // HCI Connection Timeouts 388 case L2CAP_EVENT_TIMEOUT_CHECK: 389 handle = READ_BT_16(packet, 2); 390 l2cap_channel_t * channel; 391 int used = 0; 392 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 393 channel = (l2cap_channel_t *) it; 394 if (channel->handle == handle) { 395 used = 1; 396 } 397 } 398 if (!used) { 399 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 400 } 401 break; 402 403 default: 404 break; 405 } 406 407 // pass on 408 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 409 } 410 411 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 412 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, identifier, channel->local_cid, channel->remote_cid); 413 l2cap_finialize_channel_close(channel); 414 } 415 416 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 417 418 // log_dbg("l2cap_handle_connection_request for handle %u, psm %u cid %u\n", handle, psm, source_cid); 419 l2cap_service_t *service = l2cap_get_service(psm); 420 if (!service) { 421 // 0x0002 PSM not supported 422 // log_dbg("l2cap_handle_connection_request no PSM for psm %u/n", psm); 423 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, 0x0002, 0); 424 return; 425 } 426 427 hci_connection_t * hci_connection = connection_for_handle( handle ); 428 if (!hci_connection) { 429 log_err("no hci_connection for handle %u\n", handle); 430 // TODO: emit error 431 return; 432 } 433 // alloc structure 434 // log_dbg("l2cap_handle_connection_request register channel\n"); 435 l2cap_channel_t * channel = malloc(sizeof(l2cap_channel_t)); 436 // TODO: emit error event 437 if (!channel) return; 438 439 // fill in 440 BD_ADDR_COPY(channel->address, hci_connection->address); 441 channel->psm = psm; 442 channel->handle = handle; 443 channel->connection = service->connection; 444 channel->packet_handler = service->packet_handler; 445 channel->local_cid = l2cap_next_local_cid(); 446 channel->remote_cid = source_cid; 447 channel->local_mtu = service->mtu; 448 channel->remote_mtu = L2CAP_MINIMAL_MTU; 449 450 // set initial state 451 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 452 453 // temp. store req sig id 454 channel->sig_id = sig_id; 455 456 // add to connections list 457 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 458 459 // emit incoming connection request 460 l2cap_emit_connection_request(channel); 461 } 462 463 void l2cap_accept_connection_internal(uint16_t local_cid){ 464 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 465 if (!channel) { 466 log_err("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 467 return; 468 } 469 470 // accept connection 471 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, channel->local_cid, channel->remote_cid, 0, 0); 472 473 // set real sig and state and start config 474 channel->sig_id = l2cap_next_sig_id(); 475 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 476 uint8_t config_options[4]; 477 config_options[0] = 1; // MTU 478 config_options[1] = 2; // len param 479 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 480 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 481 482 // log_dbg("new state %u\n", channel->state); 483 } 484 485 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 486 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 487 if (!channel) { 488 log_err( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 489 return; 490 } 491 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, 0, 0, reason, 0); 492 493 // discard channel 494 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 495 free (channel); 496 } 497 498 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 499 // accept the other's configuration options 500 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 501 uint16_t pos = 8; 502 while (pos < end_pos){ 503 uint8_t type = command[pos++]; 504 uint8_t length = command[pos++]; 505 // MTU { type(8): 1, len(8):2, MTU(16) } 506 if ((type & 0x7f) == 1 && length == 2){ 507 channel->remote_mtu = READ_BT_16(command, pos); 508 // log_dbg("l2cap cid %u, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 509 } 510 pos += length; 511 } 512 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 513 // send back received options 514 // l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->remote_cid, 0, 0, len-4, &command[8]); 515 // send back OK 516 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->remote_cid, 0, 0, 0, NULL); 517 } 518 519 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 520 521 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 522 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 523 uint16_t result = 0; 524 uint8_t config_options[4]; 525 526 // log_dbg("signaling handler code %u\n", code); 527 528 switch (channel->state) { 529 530 case L2CAP_STATE_WAIT_CONNECT_RSP: 531 switch (code){ 532 case CONNECTION_RESPONSE: 533 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 534 switch (result) { 535 case 0: 536 // successful connection 537 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 538 channel->sig_id = l2cap_next_sig_id(); 539 config_options[0] = 1; // MTU 540 config_options[1] = 2; // len param 541 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 542 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 543 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 544 break; 545 case 1: 546 // connection pending. get some coffee 547 break; 548 default: 549 // map l2cap connection response result to BTstack status enumeration 550 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 551 break; 552 } 553 break; 554 555 case DISCONNECTION_REQUEST: 556 l2cap_handle_disconnect_request(channel, identifier); 557 break; 558 559 default: 560 //@TODO: implement other signaling packets 561 break; 562 } 563 break; 564 565 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ: 566 switch (code) { 567 case CONFIGURE_RESPONSE: 568 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ; 569 break; 570 case CONFIGURE_REQUEST: 571 l2cap_signaling_handle_configure_request(channel, command); 572 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP; 573 break; 574 case DISCONNECTION_REQUEST: 575 l2cap_handle_disconnect_request(channel, identifier); 576 break; 577 default: 578 //@TODO: implement other signaling packets 579 break; 580 } 581 break; 582 583 case L2CAP_STATE_WAIT_CONFIG_REQ: 584 switch (code) { 585 case CONFIGURE_REQUEST: 586 l2cap_signaling_handle_configure_request(channel, command); 587 channel->state = L2CAP_STATE_OPEN; 588 l2cap_emit_channel_opened(channel, 0); // success 589 l2cap_emit_credits(channel, 1); 590 break; 591 case DISCONNECTION_REQUEST: 592 l2cap_handle_disconnect_request(channel, identifier); 593 break; 594 default: 595 //@TODO: implement other signaling packets 596 break; 597 } 598 break; 599 600 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP: 601 switch (code) { 602 case CONFIGURE_RESPONSE: 603 channel->state = L2CAP_STATE_OPEN; 604 l2cap_emit_channel_opened(channel, 0); // success 605 l2cap_emit_credits(channel, 1); 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_WAIT_DISCONNECT: 617 switch (code) { 618 case DISCONNECTION_RESPONSE: 619 l2cap_finialize_channel_close(channel); 620 break; 621 case DISCONNECTION_REQUEST: 622 l2cap_handle_disconnect_request(channel, identifier); 623 break; 624 default: 625 //@TODO: implement other signaling packets 626 break; 627 } 628 break; 629 630 case L2CAP_STATE_CLOSED: 631 // @TODO handle incoming requests 632 break; 633 634 case L2CAP_STATE_OPEN: 635 switch (code) { 636 case DISCONNECTION_REQUEST: 637 l2cap_handle_disconnect_request(channel, identifier); 638 break; 639 default: 640 //@TODO: implement other signaling packets, e.g. re-configure 641 break; 642 } 643 break; 644 default: 645 break; 646 } 647 // log_dbg("new state %u\n", channel->state); 648 } 649 650 651 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 652 653 // get code, signalind identifier and command len 654 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 655 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 656 uint16_t len = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 657 658 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 659 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 660 return; 661 } 662 663 // general commands without an assigned channel 664 switch(code) { 665 666 case CONNECTION_REQUEST: { 667 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 668 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 669 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 670 break; 671 } 672 673 case ECHO_REQUEST: { 674 // send back packet 675 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, len, &command[L2CAP_SIGNALING_COMMAND_DATA_OFFSET]); 676 break; 677 } 678 679 case INFORMATION_REQUEST: { 680 // we neither support connectionless L2CAP data nor support any flow control modes yet 681 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 682 if (infoType == 2) { 683 uint32_t features = 0; 684 // extended features request supported, however no features present 685 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, 4, &features); 686 } else { 687 // all other types are not supported 688 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 689 } 690 break;; 691 } 692 693 default: 694 break; 695 } 696 697 698 // Get potential destination CID 699 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 700 701 // Find channel for this sig_id and connection handle 702 linked_item_t *it; 703 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 704 l2cap_channel_t * channel = (l2cap_channel_t *) it; 705 if (channel->handle == handle) { 706 if (code & 1) { 707 // match odd commands by previous signaling identifier 708 if (channel->sig_id == sig_id) { 709 l2cap_signaling_handler_channel(channel, command); 710 } 711 } else { 712 // match even commands by local channel id 713 if (channel->local_cid == dest_cid) { 714 l2cap_signaling_handler_channel(channel, command); 715 } 716 } 717 } 718 } 719 } 720 721 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 722 723 // Get Channel ID 724 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 725 726 // Signaling Packet? 727 if (channel_id == 1) { 728 729 // Get Connection 730 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 731 732 uint16_t command_offset = 8; 733 while (command_offset < size) { 734 735 // handle signaling commands 736 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 737 738 // increment command_offset 739 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 740 } 741 return; 742 } 743 744 // Find channel for this channel_id and connection handle 745 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 746 if (channel) { 747 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 748 } 749 } 750 751 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 752 switch (packet_type) { 753 case HCI_EVENT_PACKET: 754 l2cap_event_handler(packet, size); 755 break; 756 case HCI_ACL_DATA_PACKET: 757 l2cap_acl_handler(packet, size); 758 break; 759 default: 760 break; 761 } 762 } 763 764 // finalize closed channel 765 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 766 channel->state = L2CAP_STATE_CLOSED; 767 l2cap_emit_channel_closed(channel); 768 769 // discard channel 770 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 771 free (channel); 772 } 773 774 l2cap_service_t * l2cap_get_service(uint16_t psm){ 775 linked_item_t *it; 776 777 // close open channels 778 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 779 l2cap_service_t * service = ((l2cap_service_t *) it); 780 if ( service->psm == psm){ 781 return service; 782 }; 783 } 784 return NULL; 785 } 786 787 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 788 // check for alread registered psm // TODO: emit error event 789 l2cap_service_t *service = l2cap_get_service(psm); 790 if (service) return; 791 792 // alloc structure // TODO: emit error event 793 service = malloc(sizeof(l2cap_service_t)); 794 if (!service) return; 795 796 // fill in 797 service->psm = psm; 798 service->mtu = mtu; 799 service->connection = connection; 800 service->packet_handler = packet_handler; 801 802 // add to services list 803 linked_list_add(&l2cap_services, (linked_item_t *) service); 804 } 805 806 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 807 l2cap_service_t *service = l2cap_get_service(psm); 808 if (!service) return; 809 linked_list_remove(&l2cap_services, (linked_item_t *) service); 810 free(service); 811 } 812 813 // 814 void l2cap_close_connection(void *connection){ 815 linked_item_t *it; 816 817 // close open channels 818 l2cap_channel_t * channel; 819 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 820 channel = (l2cap_channel_t *) it; 821 if (channel->connection == connection) { 822 channel->sig_id = l2cap_next_sig_id(); 823 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 824 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 825 } 826 } 827 828 // unregister services 829 it = (linked_item_t *) &l2cap_services; 830 while (it->next){ 831 l2cap_service_t * service = (l2cap_service_t *) it->next; 832 if (service->connection == connection){ 833 it->next = it->next->next; 834 free(service); 835 } else { 836 it = it->next; 837 } 838 } 839 } 840