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, bd_addr_t address, uint16_t psm){ 233 234 // alloc structure 235 l2cap_channel_t * chan = malloc(sizeof(l2cap_channel_t)); 236 // TODO: emit error event 237 if (!chan) return; 238 239 // fill in 240 BD_ADDR_COPY(chan->address, address); 241 chan->psm = psm; 242 chan->handle = 0; 243 chan->connection = connection; 244 chan->packet_handler = packet_handler; 245 chan->remote_mtu = L2CAP_MINIMAL_MTU; 246 chan->local_mtu = 150; // TODO allow to specify this 247 248 // flow control 249 chan->packets_granted = 0; 250 chan->packets_outgoing = 0; 251 252 // set initial state 253 chan->state = L2CAP_STATE_CLOSED; 254 chan->sig_id = L2CAP_SIG_ID_INVALID; 255 256 // add to connections list 257 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 258 259 // send connection request 260 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 261 hci_send_cmd(&hci_create_connection, address, 0x18, 0, 0, 0, 0); 262 } 263 264 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 265 // find channel for local_cid 266 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 267 if (channel) { 268 channel->sig_id = l2cap_next_sig_id(); 269 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 270 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 271 } 272 } 273 274 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 275 linked_item_t *it; 276 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 277 l2cap_channel_t * channel = (l2cap_channel_t *) it; 278 if ( ! BD_ADDR_CMP( channel->address, address) ){ 279 if (channel->state == L2CAP_STATE_CLOSED) { 280 // failure, forward error code 281 l2cap_emit_channel_opened(channel, status); 282 // discard channel 283 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 284 free (channel); 285 } 286 } 287 } 288 } 289 290 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 291 linked_item_t *it; 292 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 293 l2cap_channel_t * channel = (l2cap_channel_t *) it; 294 if ( ! BD_ADDR_CMP( channel->address, address) ){ 295 if (channel->state == L2CAP_STATE_CLOSED) { 296 // success, start l2cap handshake 297 channel->handle = handle; 298 channel->sig_id = l2cap_next_sig_id(); 299 channel->local_cid = l2cap_next_local_cid(); 300 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 301 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->sig_id, channel->psm, channel->local_cid); 302 } 303 } 304 } 305 } 306 307 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 308 309 bd_addr_t address; 310 hci_con_handle_t handle; 311 linked_item_t *it; 312 int i; 313 314 switch(packet[0]){ 315 316 // handle connection complete events 317 case HCI_EVENT_CONNECTION_COMPLETE: 318 bt_flip_addr(address, &packet[5]); 319 if (packet[2] == 0){ 320 handle = READ_BT_16(packet, 3); 321 l2cap_handle_connection_success_for_addr(address, handle); 322 } else { 323 l2cap_handle_connection_failed_for_addr(address, packet[2]); 324 } 325 break; 326 327 // handle successful create connection cancel command 328 case HCI_EVENT_COMMAND_COMPLETE: 329 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 330 if (packet[5] == 0){ 331 bt_flip_addr(address, &packet[6]); 332 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 333 l2cap_handle_connection_failed_for_addr(address, 0x16); 334 } 335 } 336 break; 337 338 // handle disconnection complete events 339 case HCI_EVENT_DISCONNECTION_COMPLETE: 340 // send l2cap disconnect events for all channels on this handle 341 handle = READ_BT_16(packet, 3); 342 // only access next element to allows for removal 343 for (it = (linked_item_t *) &l2cap_channels; it->next ; it = it->next){ 344 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 345 if ( channel->handle == handle ){ 346 // update prev item before free'ing next element 347 it->next = it->next->next; 348 l2cap_finialize_channel_close(channel); 349 } 350 } 351 break; 352 353 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 354 for (i=0; i<packet[2];i++){ 355 handle = READ_BT_16(packet, 3 + 2*i); 356 uint16_t num_packets = READ_BT_16(packet, 3 + packet[2]*2 + 2*i); 357 while (num_packets) { 358 359 // find channels with max nr of pending outgoing packets 360 l2cap_channel_t * fullest_channel = NULL; 361 int max_nr_pending = 0; 362 for (it = (linked_item_t *) &l2cap_channels; it->next ; it = it->next){ 363 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 364 if (channel->packets_outgoing > max_nr_pending){ 365 fullest_channel = channel; 366 max_nr_pending = channel->packets_outgoing; 367 } 368 } 369 370 // decrease packets 371 if (fullest_channel) { 372 fullest_channel->packets_outgoing--; 373 // log_dbg("hci_number_completed_packet (l2cap) for cid %u, outgoing count %u\n", 374 // fullest_channel->local_cid, fullest_channel->packets_outgoing); 375 } else { 376 log_err("hci_number_completed_packet but no outgoing packet in records\n"); 377 } 378 379 // handled! 380 num_packets--; 381 } 382 } 383 l2cap_hand_out_credits(); 384 break; 385 386 // HCI Connection Timeouts 387 case L2CAP_EVENT_TIMEOUT_CHECK: 388 handle = READ_BT_16(packet, 2); 389 l2cap_channel_t * channel; 390 int used = 0; 391 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 392 channel = (l2cap_channel_t *) it; 393 if (channel->handle == handle) { 394 used = 1; 395 } 396 } 397 if (!used) { 398 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 399 } 400 break; 401 402 default: 403 break; 404 } 405 406 // pass on 407 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 408 } 409 410 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 411 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, identifier, channel->local_cid, channel->remote_cid); 412 l2cap_finialize_channel_close(channel); 413 } 414 415 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 416 417 // log_dbg("l2cap_handle_connection_request for handle %u, psm %u cid %u\n", handle, psm, source_cid); 418 l2cap_service_t *service = l2cap_get_service(psm); 419 if (!service) { 420 // 0x0002 PSM not supported 421 // log_dbg("l2cap_handle_connection_request no PSM for psm %u/n", psm); 422 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, 0x0002, 0); 423 return; 424 } 425 426 hci_connection_t * hci_connection = connection_for_handle( handle ); 427 if (!hci_connection) { 428 log_err("no hci_connection for handle %u\n", handle); 429 // TODO: emit error 430 return; 431 } 432 // alloc structure 433 // log_dbg("l2cap_handle_connection_request register channel\n"); 434 l2cap_channel_t * channel = malloc(sizeof(l2cap_channel_t)); 435 // TODO: emit error event 436 if (!channel) return; 437 438 // fill in 439 BD_ADDR_COPY(channel->address, hci_connection->address); 440 channel->psm = psm; 441 channel->handle = handle; 442 channel->connection = service->connection; 443 channel->packet_handler = service->packet_handler; 444 channel->local_cid = l2cap_next_local_cid(); 445 channel->remote_cid = source_cid; 446 channel->local_mtu = service->mtu; 447 channel->remote_mtu = L2CAP_MINIMAL_MTU; 448 449 // set initial state 450 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 451 452 // temp. store req sig id 453 channel->sig_id = sig_id; 454 455 // add to connections list 456 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 457 458 // emit incoming connection request 459 l2cap_emit_connection_request(channel); 460 } 461 462 void l2cap_accept_connection_internal(uint16_t local_cid){ 463 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 464 if (!channel) { 465 log_err("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 466 return; 467 } 468 469 // accept connection 470 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, channel->local_cid, channel->remote_cid, 0, 0); 471 472 // set real sig and state and start config 473 channel->sig_id = l2cap_next_sig_id(); 474 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 475 uint8_t config_options[4]; 476 config_options[0] = 1; // MTU 477 config_options[1] = 2; // len param 478 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 479 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 480 481 // log_dbg("new state %u\n", channel->state); 482 } 483 484 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 485 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 486 if (!channel) { 487 log_err( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 488 return; 489 } 490 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, 0, 0, reason, 0); 491 492 // discard channel 493 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 494 free (channel); 495 } 496 497 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 498 // accept the other's configuration options 499 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 500 uint16_t pos = 8; 501 while (pos < end_pos){ 502 uint8_t type = command[pos++]; 503 uint8_t length = command[pos++]; 504 // MTU { type(8): 1, len(8):2, MTU(16) } 505 if ((type & 0x7f) == 1 && length == 2){ 506 channel->remote_mtu = READ_BT_16(command, pos); 507 // log_dbg("l2cap cid %u, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 508 } 509 pos += length; 510 } 511 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 512 // send back received options 513 // l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->remote_cid, 0, 0, len-4, &command[8]); 514 // send back OK 515 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->remote_cid, 0, 0, 0, NULL); 516 } 517 518 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 519 520 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 521 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 522 uint16_t result = 0; 523 uint8_t config_options[4]; 524 525 // log_dbg("signaling handler code %u\n", code); 526 527 switch (channel->state) { 528 529 case L2CAP_STATE_WAIT_CONNECT_RSP: 530 switch (code){ 531 case CONNECTION_RESPONSE: 532 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 533 switch (result) { 534 case 0: 535 // successful connection 536 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 537 channel->sig_id = l2cap_next_sig_id(); 538 config_options[0] = 1; // MTU 539 config_options[1] = 2; // len param 540 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 541 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 542 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 543 break; 544 case 1: 545 // connection pending. get some coffee 546 break; 547 default: 548 // map l2cap connection response result to BTstack status enumeration 549 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 550 break; 551 } 552 break; 553 554 case DISCONNECTION_REQUEST: 555 l2cap_handle_disconnect_request(channel, identifier); 556 break; 557 558 default: 559 //@TODO: implement other signaling packets 560 break; 561 } 562 break; 563 564 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ: 565 switch (code) { 566 case CONFIGURE_RESPONSE: 567 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ; 568 break; 569 case CONFIGURE_REQUEST: 570 l2cap_signaling_handle_configure_request(channel, command); 571 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP; 572 break; 573 case DISCONNECTION_REQUEST: 574 l2cap_handle_disconnect_request(channel, identifier); 575 break; 576 default: 577 //@TODO: implement other signaling packets 578 break; 579 } 580 break; 581 582 case L2CAP_STATE_WAIT_CONFIG_REQ: 583 switch (code) { 584 case CONFIGURE_REQUEST: 585 l2cap_signaling_handle_configure_request(channel, command); 586 channel->state = L2CAP_STATE_OPEN; 587 l2cap_emit_channel_opened(channel, 0); // success 588 l2cap_emit_credits(channel, 1); 589 break; 590 case DISCONNECTION_REQUEST: 591 l2cap_handle_disconnect_request(channel, identifier); 592 break; 593 default: 594 //@TODO: implement other signaling packets 595 break; 596 } 597 break; 598 599 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP: 600 switch (code) { 601 case CONFIGURE_RESPONSE: 602 channel->state = L2CAP_STATE_OPEN; 603 l2cap_emit_channel_opened(channel, 0); // success 604 l2cap_emit_credits(channel, 1); 605 break; 606 case DISCONNECTION_REQUEST: 607 l2cap_handle_disconnect_request(channel, identifier); 608 break; 609 default: 610 //@TODO: implement other signaling packets 611 break; 612 } 613 break; 614 615 case L2CAP_STATE_WAIT_DISCONNECT: 616 switch (code) { 617 case DISCONNECTION_RESPONSE: 618 l2cap_finialize_channel_close(channel); 619 break; 620 case DISCONNECTION_REQUEST: 621 l2cap_handle_disconnect_request(channel, identifier); 622 break; 623 default: 624 //@TODO: implement other signaling packets 625 break; 626 } 627 break; 628 629 case L2CAP_STATE_CLOSED: 630 // @TODO handle incoming requests 631 break; 632 633 case L2CAP_STATE_OPEN: 634 switch (code) { 635 case DISCONNECTION_REQUEST: 636 l2cap_handle_disconnect_request(channel, identifier); 637 break; 638 default: 639 //@TODO: implement other signaling packets, e.g. re-configure 640 break; 641 } 642 break; 643 default: 644 break; 645 } 646 // log_dbg("new state %u\n", channel->state); 647 } 648 649 650 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 651 652 // get code, signalind identifier and command len 653 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 654 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 655 uint16_t len = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 656 657 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 658 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 659 return; 660 } 661 662 // general commands without an assigned channel 663 switch(code) { 664 665 case CONNECTION_REQUEST: { 666 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 667 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 668 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 669 break; 670 } 671 672 case ECHO_REQUEST: { 673 // send back packet 674 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, len, &command[L2CAP_SIGNALING_COMMAND_DATA_OFFSET]); 675 break; 676 } 677 678 case INFORMATION_REQUEST: { 679 // we neither support connectionless L2CAP data nor support any flow control modes yet 680 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 681 if (infoType == 2) { 682 uint32_t features = 0; 683 // extended features request supported, however no features present 684 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, 4, &features); 685 } else { 686 // all other types are not supported 687 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 688 } 689 break;; 690 } 691 692 default: 693 break; 694 } 695 696 697 // Get potential destination CID 698 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 699 700 // Find channel for this sig_id and connection handle 701 linked_item_t *it; 702 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 703 l2cap_channel_t * channel = (l2cap_channel_t *) it; 704 if (channel->handle == handle) { 705 if (code & 1) { 706 // match odd commands by previous signaling identifier 707 if (channel->sig_id == sig_id) { 708 l2cap_signaling_handler_channel(channel, command); 709 } 710 } else { 711 // match even commands by local channel id 712 if (channel->local_cid == dest_cid) { 713 l2cap_signaling_handler_channel(channel, command); 714 } 715 } 716 } 717 } 718 } 719 720 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 721 722 // Get Channel ID 723 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 724 725 // Signaling Packet? 726 if (channel_id == 1) { 727 728 // Get Connection 729 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 730 731 uint16_t command_offset = 8; 732 while (command_offset < size) { 733 734 // handle signaling commands 735 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 736 737 // increment command_offset 738 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 739 } 740 return; 741 } 742 743 // Find channel for this channel_id and connection handle 744 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 745 if (channel) { 746 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 747 } 748 } 749 750 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 751 switch (packet_type) { 752 case HCI_EVENT_PACKET: 753 l2cap_event_handler(packet, size); 754 break; 755 case HCI_ACL_DATA_PACKET: 756 l2cap_acl_handler(packet, size); 757 break; 758 default: 759 break; 760 } 761 } 762 763 // finalize closed channel 764 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 765 channel->state = L2CAP_STATE_CLOSED; 766 l2cap_emit_channel_closed(channel); 767 768 // discard channel 769 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 770 free (channel); 771 } 772 773 l2cap_service_t * l2cap_get_service(uint16_t psm){ 774 linked_item_t *it; 775 776 // close open channels 777 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 778 l2cap_service_t * service = ((l2cap_service_t *) it); 779 if ( service->psm == psm){ 780 return service; 781 }; 782 } 783 return NULL; 784 } 785 786 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 787 // check for alread registered psm // TODO: emit error event 788 l2cap_service_t *service = l2cap_get_service(psm); 789 if (service) return; 790 791 // alloc structure // TODO: emit error event 792 service = malloc(sizeof(l2cap_service_t)); 793 if (!service) return; 794 795 // fill in 796 service->psm = psm; 797 service->mtu = mtu; 798 service->connection = connection; 799 service->packet_handler = packet_handler; 800 801 // add to services list 802 linked_list_add(&l2cap_services, (linked_item_t *) service); 803 } 804 805 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 806 l2cap_service_t *service = l2cap_get_service(psm); 807 if (!service) return; 808 linked_list_remove(&l2cap_services, (linked_item_t *) service); 809 free(service); 810 } 811 812 // 813 void l2cap_close_connection(void *connection){ 814 linked_item_t *it; 815 816 // close open channels 817 l2cap_channel_t * channel; 818 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 819 channel = (l2cap_channel_t *) it; 820 if (channel->connection == connection) { 821 channel->sig_id = l2cap_next_sig_id(); 822 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 823 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 824 } 825 } 826 827 // unregister services 828 it = (linked_item_t *) &l2cap_services; 829 while (it->next){ 830 l2cap_service_t * service = (l2cap_service_t *) it->next; 831 if (service->connection == connection){ 832 it->next = it->next->next; 833 free(service); 834 } else { 835 it = it->next; 836 } 837 } 838 } 839