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 // nr of buffered acl packets in outgoing queue to get max performance 58 #define NR_BUFFERED_ACL_PACKETS 3 59 60 // offsets for L2CAP SIGNALING COMMANDS 61 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 62 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 63 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 64 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 65 66 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); 67 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size); 68 69 static uint8_t * sig_buffer = NULL; 70 static linked_list_t l2cap_channels = NULL; 71 static linked_list_t l2cap_services = NULL; 72 static uint8_t * acl_buffer = NULL; 73 static void (*packet_handler) (void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) = null_packet_handler; 74 75 void l2cap_init(){ 76 sig_buffer = malloc( L2CAP_MINIMAL_MTU ); 77 acl_buffer = malloc( HCI_ACL_3DH5_SIZE); 78 79 // 80 // register callback with HCI 81 // 82 hci_register_packet_handler(&l2cap_packet_handler); 83 } 84 85 86 /** Register L2CAP packet handlers */ 87 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 88 } 89 void l2cap_register_packet_handler(void (*handler)(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 90 packet_handler = handler; 91 } 92 93 // notify client/protocol handler 94 void l2cap_dispatch(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 95 if (channel->packet_handler) { 96 (* (channel->packet_handler))(type, channel->local_cid, data, size); 97 } else { 98 (*packet_handler)(channel->connection, type, channel->local_cid, data, size); 99 } 100 } 101 102 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 103 uint8_t event[17]; 104 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 105 event[1] = sizeof(event) - 2; 106 event[2] = status; 107 bt_flip_addr(&event[3], channel->address); 108 bt_store_16(event, 9, channel->handle); 109 bt_store_16(event, 11, channel->psm); 110 bt_store_16(event, 13, channel->local_cid); 111 bt_store_16(event, 15, channel->remote_cid); 112 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 113 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 114 } 115 116 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 117 uint8_t event[4]; 118 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 119 event[1] = sizeof(event) - 2; 120 bt_store_16(event, 2, channel->local_cid); 121 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 122 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 123 } 124 125 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 126 uint8_t event[16]; 127 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 128 event[1] = sizeof(event) - 2; 129 bt_flip_addr(&event[2], channel->address); 130 bt_store_16(event, 8, channel->handle); 131 bt_store_16(event, 10, channel->psm); 132 bt_store_16(event, 12, channel->local_cid); 133 bt_store_16(event, 14, channel->remote_cid); 134 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 135 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 136 } 137 138 void l2cap_emit_credits(l2cap_channel_t *channel, uint8_t credits) { 139 // track credits 140 channel->packets_granted += credits; 141 // log_dbg("l2cap_emit_credits for cid %u, credits now: %u (+%u)\n", channel->local_cid, channel->packets_granted, credits); 142 143 uint8_t event[5]; 144 event[0] = L2CAP_EVENT_CREDITS; 145 event[1] = sizeof(event) - 2; 146 bt_store_16(event, 2, channel->local_cid); 147 event[4] = credits; 148 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 149 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 150 } 151 152 void l2cap_hand_out_credits(void){ 153 linked_item_t *it; 154 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 155 if (!hci_number_free_acl_slots()) return; 156 l2cap_channel_t * channel = (l2cap_channel_t *) it; 157 if (channel->state != L2CAP_STATE_OPEN) continue; 158 if (hci_number_outgoing_packets(channel->handle) < NR_BUFFERED_ACL_PACKETS && channel->packets_granted == 0) { 159 l2cap_emit_credits(channel, 1); 160 } 161 } 162 } 163 164 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 165 linked_item_t *it; 166 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 167 l2cap_channel_t * channel = (l2cap_channel_t *) it; 168 if ( channel->local_cid == local_cid) { 169 return channel; 170 } 171 } 172 return NULL; 173 } 174 175 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 176 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 177 if (channel) { 178 return channel->remote_mtu; 179 } 180 return 0; 181 } 182 183 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 184 // log_dbg("l2cap_send_signaling_packet type %u\n", cmd); 185 va_list argptr; 186 va_start(argptr, identifier); 187 uint16_t len = l2cap_create_signaling_internal(sig_buffer, handle, cmd, identifier, argptr); 188 va_end(argptr); 189 return hci_send_acl_packet(sig_buffer, len); 190 } 191 192 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 193 194 // check for free places on BT module 195 if (!hci_number_free_acl_slots()) { 196 log_dbg("l2cap_send_internal cid %u, BT module full <-----\n", local_cid); 197 return -1; 198 } 199 int err = 0; 200 201 // find channel for local_cid, construct l2cap packet and send 202 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 203 if (channel) { 204 // track sending 205 ++channel->packets_outgoing; 206 if (channel->packets_granted > 0){ 207 --channel->packets_granted; 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 } else { 211 log_err("l2cap_send_internal cid %u, no credits!\n", local_cid); 212 } 213 214 // 0 - Connection handle : PB=10 : BC=00 215 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 216 // 2 - ACL length 217 bt_store_16(acl_buffer, 2, len + 4); 218 // 4 - L2CAP packet length 219 bt_store_16(acl_buffer, 4, len + 0); 220 // 6 - L2CAP channel DEST 221 bt_store_16(acl_buffer, 6, channel->remote_cid); 222 // 8 - data 223 memcpy(&acl_buffer[8], data, len); 224 225 // send 226 err = hci_send_acl_packet(acl_buffer, len+8); 227 } 228 229 l2cap_hand_out_credits(); 230 231 return err; 232 } 233 234 // open outgoing L2CAP channel 235 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 236 bd_addr_t address, uint16_t psm, uint16_t mtu){ 237 238 // alloc structure 239 l2cap_channel_t * chan = malloc(sizeof(l2cap_channel_t)); 240 // TODO: emit error event 241 if (!chan) return; 242 243 // limit local mtu to max acl packet length 244 if (mtu > hci_max_acl_data_packet_length()) { 245 mtu = hci_max_acl_data_packet_length(); 246 } 247 248 // fill in 249 BD_ADDR_COPY(chan->address, address); 250 chan->psm = psm; 251 chan->handle = 0; 252 chan->connection = connection; 253 chan->packet_handler = packet_handler; 254 chan->remote_mtu = L2CAP_MINIMAL_MTU; 255 chan->local_mtu = mtu; 256 257 // flow control 258 chan->packets_granted = 0; 259 chan->packets_outgoing = 0; 260 261 // set initial state 262 chan->state = L2CAP_STATE_CLOSED; 263 chan->sig_id = L2CAP_SIG_ID_INVALID; 264 265 // add to connections list 266 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 267 268 // send connection request 269 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 270 hci_send_cmd(&hci_create_connection, address, 0xcc18, 0, 0, 0, 1); 271 } 272 273 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 274 // find channel for local_cid 275 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 276 if (channel) { 277 channel->sig_id = l2cap_next_sig_id(); 278 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 279 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 280 } 281 } 282 283 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 284 linked_item_t *it = (linked_item_t *) &l2cap_channels; 285 while (it->next){ 286 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 287 if ( ! BD_ADDR_CMP( channel->address, address) ){ 288 if (channel->state == L2CAP_STATE_CLOSED) { 289 // failure, forward error code 290 l2cap_emit_channel_opened(channel, status); 291 // discard channel 292 it->next = it->next->next; 293 free (channel); 294 } 295 } else { 296 it = it->next; 297 } 298 } 299 } 300 301 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 302 linked_item_t *it; 303 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 304 l2cap_channel_t * channel = (l2cap_channel_t *) it; 305 if ( ! BD_ADDR_CMP( channel->address, address) ){ 306 if (channel->state == L2CAP_STATE_CLOSED) { 307 // success, start l2cap handshake 308 channel->handle = handle; 309 channel->sig_id = l2cap_next_sig_id(); 310 channel->local_cid = l2cap_next_local_cid(); 311 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 312 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->sig_id, channel->psm, channel->local_cid); 313 } 314 } 315 } 316 } 317 318 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 319 320 bd_addr_t address; 321 hci_con_handle_t handle; 322 linked_item_t *it; 323 int i; 324 325 switch(packet[0]){ 326 327 // handle connection complete events 328 case HCI_EVENT_CONNECTION_COMPLETE: 329 bt_flip_addr(address, &packet[5]); 330 if (packet[2] == 0){ 331 handle = READ_BT_16(packet, 3); 332 l2cap_handle_connection_success_for_addr(address, handle); 333 } else { 334 l2cap_handle_connection_failed_for_addr(address, packet[2]); 335 } 336 break; 337 338 // handle successful create connection cancel command 339 case HCI_EVENT_COMMAND_COMPLETE: 340 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 341 if (packet[5] == 0){ 342 bt_flip_addr(address, &packet[6]); 343 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 344 l2cap_handle_connection_failed_for_addr(address, 0x16); 345 } 346 } 347 break; 348 349 // handle disconnection complete events 350 case HCI_EVENT_DISCONNECTION_COMPLETE: 351 // send l2cap disconnect events for all channels on this handle 352 handle = READ_BT_16(packet, 3); 353 it = (linked_item_t *) &l2cap_channels; 354 while (it->next){ 355 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 356 if ( channel->handle == handle ){ 357 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 358 it->next = it->next->next; 359 l2cap_emit_channel_closed(channel); 360 free (channel); 361 } else { 362 it = it->next; 363 } 364 } 365 break; 366 367 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 368 for (i=0; i<packet[2];i++){ 369 handle = READ_BT_16(packet, 3 + 2*i); 370 uint16_t num_packets = READ_BT_16(packet, 3 + packet[2]*2 + 2*i); 371 while (num_packets) { 372 373 // find channels with max nr of pending outgoing packets 374 l2cap_channel_t * fullest_channel = NULL; 375 int max_nr_pending = 0; 376 for (it = (linked_item_t *) &l2cap_channels; it->next ; it = it->next){ 377 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 378 if (channel->packets_outgoing > max_nr_pending){ 379 fullest_channel = channel; 380 max_nr_pending = channel->packets_outgoing; 381 } 382 } 383 384 // decrease packets 385 if (fullest_channel) { 386 fullest_channel->packets_outgoing--; 387 // log_dbg("hci_number_completed_packet (l2cap) for cid %u, outgoing count %u\n", 388 // fullest_channel->local_cid, fullest_channel->packets_outgoing); 389 } else { 390 log_err("hci_number_completed_packet but no outgoing packet in records\n"); 391 } 392 393 // handled! 394 num_packets--; 395 } 396 } 397 l2cap_hand_out_credits(); 398 break; 399 400 // HCI Connection Timeouts 401 case L2CAP_EVENT_TIMEOUT_CHECK: 402 handle = READ_BT_16(packet, 2); 403 if (hci_authentication_active_for_handle(handle)) break; 404 l2cap_channel_t * channel; 405 int used = 0; 406 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 407 channel = (l2cap_channel_t *) it; 408 if (channel->handle == handle) { 409 used = 1; 410 } 411 } 412 if (!used) { 413 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 414 } 415 break; 416 417 default: 418 break; 419 } 420 421 // pass on 422 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 423 } 424 425 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 426 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, identifier, channel->local_cid, channel->remote_cid); 427 l2cap_finialize_channel_close(channel); 428 } 429 430 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 431 432 // log_dbg("l2cap_handle_connection_request for handle %u, psm %u cid %u\n", handle, psm, source_cid); 433 l2cap_service_t *service = l2cap_get_service(psm); 434 if (!service) { 435 // 0x0002 PSM not supported 436 // log_dbg("l2cap_handle_connection_request no PSM for psm %u/n", psm); 437 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, 0x0002, 0); 438 return; 439 } 440 441 hci_connection_t * hci_connection = connection_for_handle( handle ); 442 if (!hci_connection) { 443 log_err("no hci_connection for handle %u\n", handle); 444 // TODO: emit error 445 return; 446 } 447 // alloc structure 448 // log_dbg("l2cap_handle_connection_request register channel\n"); 449 l2cap_channel_t * channel = malloc(sizeof(l2cap_channel_t)); 450 // TODO: emit error event 451 if (!channel) return; 452 453 // fill in 454 BD_ADDR_COPY(channel->address, hci_connection->address); 455 channel->psm = psm; 456 channel->handle = handle; 457 channel->connection = service->connection; 458 channel->packet_handler = service->packet_handler; 459 channel->local_cid = l2cap_next_local_cid(); 460 channel->remote_cid = source_cid; 461 channel->local_mtu = service->mtu; 462 channel->remote_mtu = L2CAP_DEFAULT_MTU; 463 464 // limit local mtu to max acl packet length 465 if (channel->local_mtu > hci_max_acl_data_packet_length()) { 466 channel->local_mtu = hci_max_acl_data_packet_length(); 467 } 468 469 // set initial state 470 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 471 472 // temp. store req sig id 473 channel->sig_id = sig_id; 474 475 // add to connections list 476 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 477 478 // emit incoming connection request 479 l2cap_emit_connection_request(channel); 480 } 481 482 void l2cap_accept_connection_internal(uint16_t local_cid){ 483 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 484 if (!channel) { 485 log_err("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 486 return; 487 } 488 489 // accept connection 490 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, channel->local_cid, channel->remote_cid, 0, 0); 491 492 // set real sig and state and start config 493 channel->sig_id = l2cap_next_sig_id(); 494 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 495 uint8_t config_options[4]; 496 config_options[0] = 1; // MTU 497 config_options[1] = 2; // len param 498 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 499 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 500 501 // log_dbg("new state %u\n", channel->state); 502 } 503 504 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 505 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 506 if (!channel) { 507 log_err( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 508 return; 509 } 510 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->sig_id, 0, 0, reason, 0); 511 512 // discard channel 513 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 514 free (channel); 515 } 516 517 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 518 // accept the other's configuration options 519 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 520 uint16_t pos = 8; 521 while (pos < end_pos){ 522 uint8_t type = command[pos++]; 523 uint8_t length = command[pos++]; 524 // MTU { type(8): 1, len(8):2, MTU(16) } 525 if ((type & 0x7f) == 1 && length == 2){ 526 channel->remote_mtu = READ_BT_16(command, pos); 527 // log_dbg("l2cap cid %u, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 528 } 529 pos += length; 530 } 531 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 532 // send back OK 533 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->remote_cid, 0, 0, 0, NULL); 534 } 535 536 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 537 538 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 539 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 540 uint16_t result = 0; 541 uint8_t config_options[4]; 542 543 // log_dbg("signaling handler code %u\n", code); 544 545 switch (channel->state) { 546 547 case L2CAP_STATE_WAIT_CONNECT_RSP: 548 switch (code){ 549 case CONNECTION_RESPONSE: 550 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 551 switch (result) { 552 case 0: 553 // successful connection 554 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 555 channel->sig_id = l2cap_next_sig_id(); 556 config_options[0] = 1; // MTU 557 config_options[1] = 2; // len param 558 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 559 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 560 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 561 562 #if 0 563 channel->state = L2CAP_STATE_OPEN; 564 l2cap_emit_channel_opened(channel, 0); // success 565 l2cap_emit_credits(channel, 1); 566 #endif 567 break; 568 case 1: 569 // connection pending. get some coffee 570 break; 571 default: 572 // channel closed 573 channel->state = L2CAP_STATE_CLOSED; 574 575 // map l2cap connection response result to BTstack status enumeration 576 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 577 578 // drop link key if security block 579 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 580 hci_drop_link_key_for_bd_addr(&channel->address); 581 } 582 583 // discard channel 584 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 585 free (channel); 586 break; 587 } 588 break; 589 590 case DISCONNECTION_REQUEST: 591 l2cap_handle_disconnect_request(channel, identifier); 592 break; 593 594 default: 595 //@TODO: implement other signaling packets 596 break; 597 } 598 break; 599 600 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ: 601 switch (code) { 602 case CONFIGURE_RESPONSE: 603 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ; 604 break; 605 case CONFIGURE_REQUEST: 606 l2cap_signaling_handle_configure_request(channel, command); 607 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP; 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_WAIT_CONFIG_REQ: 619 switch (code) { 620 case CONFIGURE_REQUEST: 621 l2cap_signaling_handle_configure_request(channel, command); 622 channel->state = L2CAP_STATE_OPEN; 623 l2cap_emit_channel_opened(channel, 0); // success 624 l2cap_emit_credits(channel, 1); 625 break; 626 case DISCONNECTION_REQUEST: 627 l2cap_handle_disconnect_request(channel, identifier); 628 break; 629 default: 630 //@TODO: implement other signaling packets 631 break; 632 } 633 break; 634 635 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP: 636 switch (code) { 637 case CONFIGURE_RESPONSE: 638 channel->state = L2CAP_STATE_OPEN; 639 l2cap_emit_channel_opened(channel, 0); // success 640 l2cap_emit_credits(channel, 1); 641 break; 642 case DISCONNECTION_REQUEST: 643 l2cap_handle_disconnect_request(channel, identifier); 644 break; 645 default: 646 //@TODO: implement other signaling packets 647 break; 648 } 649 break; 650 651 case L2CAP_STATE_WAIT_DISCONNECT: 652 switch (code) { 653 case DISCONNECTION_RESPONSE: 654 l2cap_finialize_channel_close(channel); 655 break; 656 case DISCONNECTION_REQUEST: 657 l2cap_handle_disconnect_request(channel, identifier); 658 break; 659 default: 660 //@TODO: implement other signaling packets 661 break; 662 } 663 break; 664 665 case L2CAP_STATE_CLOSED: 666 // @TODO handle incoming requests 667 break; 668 669 case L2CAP_STATE_OPEN: 670 switch (code) { 671 case DISCONNECTION_REQUEST: 672 l2cap_handle_disconnect_request(channel, identifier); 673 break; 674 default: 675 //@TODO: implement other signaling packets, e.g. re-configure 676 break; 677 } 678 break; 679 default: 680 break; 681 } 682 // log_dbg("new state %u\n", channel->state); 683 } 684 685 686 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 687 688 // get code, signalind identifier and command len 689 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 690 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 691 uint16_t len = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 692 693 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 694 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 695 return; 696 } 697 698 // general commands without an assigned channel 699 switch(code) { 700 701 case CONNECTION_REQUEST: { 702 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 703 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 704 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 705 break; 706 } 707 708 case ECHO_REQUEST: { 709 // send back packet 710 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, len, &command[L2CAP_SIGNALING_COMMAND_DATA_OFFSET]); 711 break; 712 } 713 714 case INFORMATION_REQUEST: { 715 // we neither support connectionless L2CAP data nor support any flow control modes yet 716 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 717 if (infoType == 2) { 718 uint32_t features = 0; 719 // extended features request supported, however no features present 720 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, 4, &features); 721 } else { 722 // all other types are not supported 723 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 724 } 725 break;; 726 } 727 728 default: 729 break; 730 } 731 732 733 // Get potential destination CID 734 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 735 736 // Find channel for this sig_id and connection handle 737 linked_item_t *it; 738 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 739 l2cap_channel_t * channel = (l2cap_channel_t *) it; 740 if (channel->handle == handle) { 741 if (code & 1) { 742 // match odd commands by previous signaling identifier 743 if (channel->sig_id == sig_id) { 744 l2cap_signaling_handler_channel(channel, command); 745 break; 746 } 747 } else { 748 // match even commands by local channel id 749 if (channel->local_cid == dest_cid) { 750 l2cap_signaling_handler_channel(channel, command); 751 break; 752 } 753 } 754 } 755 } 756 } 757 758 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 759 760 // Get Channel ID 761 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 762 763 // Signaling Packet? 764 if (channel_id == 1) { 765 766 // Get Connection 767 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 768 769 uint16_t command_offset = 8; 770 while (command_offset < size) { 771 772 // handle signaling commands 773 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 774 775 // increment command_offset 776 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 777 } 778 return; 779 } 780 781 // Find channel for this channel_id and connection handle 782 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 783 if (channel) { 784 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 785 } 786 } 787 788 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 789 switch (packet_type) { 790 case HCI_EVENT_PACKET: 791 l2cap_event_handler(packet, size); 792 break; 793 case HCI_ACL_DATA_PACKET: 794 l2cap_acl_handler(packet, size); 795 break; 796 default: 797 break; 798 } 799 } 800 801 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 802 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 803 channel->state = L2CAP_STATE_CLOSED; 804 l2cap_emit_channel_closed(channel); 805 // discard channel 806 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 807 free (channel); 808 } 809 810 l2cap_service_t * l2cap_get_service(uint16_t psm){ 811 linked_item_t *it; 812 813 // close open channels 814 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 815 l2cap_service_t * service = ((l2cap_service_t *) it); 816 if ( service->psm == psm){ 817 return service; 818 }; 819 } 820 return NULL; 821 } 822 823 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 824 // check for alread registered psm // TODO: emit error event 825 l2cap_service_t *service = l2cap_get_service(psm); 826 if (service) return; 827 828 // alloc structure // TODO: emit error event 829 service = malloc(sizeof(l2cap_service_t)); 830 if (!service) return; 831 832 // fill in 833 service->psm = psm; 834 service->mtu = mtu; 835 service->connection = connection; 836 service->packet_handler = packet_handler; 837 838 // add to services list 839 linked_list_add(&l2cap_services, (linked_item_t *) service); 840 } 841 842 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 843 l2cap_service_t *service = l2cap_get_service(psm); 844 if (!service) return; 845 linked_list_remove(&l2cap_services, (linked_item_t *) service); 846 free(service); 847 } 848 849 // 850 void l2cap_close_connection(void *connection){ 851 linked_item_t *it; 852 853 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 854 l2cap_channel_t * channel; 855 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 856 channel = (l2cap_channel_t *) it; 857 if (channel->connection == connection) { 858 channel->sig_id = l2cap_next_sig_id(); 859 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 860 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 861 } 862 } 863 864 // unregister services 865 it = (linked_item_t *) &l2cap_services; 866 while (it->next) { 867 l2cap_service_t * service = (l2cap_service_t *) it->next; 868 if (service->connection == connection){ 869 it->next = it->next->next; 870 free(service); 871 } else { 872 it = it->next; 873 } 874 } 875 } 876