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(){ 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 // validate mtu 244 if (hci_max_acl_data_packet_length() < mtu) { 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, 0); 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_MINIMAL_MTU; 463 464 // validate mtu 465 if (hci_max_acl_data_packet_length() < channel->local_mtu) { 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 received options 533 // l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->remote_cid, 0, 0, len-4, &command[8]); 534 // send back OK 535 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, identifier, channel->remote_cid, 0, 0, 0, NULL); 536 } 537 538 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 539 540 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 541 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 542 uint16_t result = 0; 543 uint8_t config_options[4]; 544 545 // log_dbg("signaling handler code %u\n", code); 546 547 switch (channel->state) { 548 549 case L2CAP_STATE_WAIT_CONNECT_RSP: 550 switch (code){ 551 case CONNECTION_RESPONSE: 552 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 553 switch (result) { 554 case 0: 555 // successful connection 556 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 557 channel->sig_id = l2cap_next_sig_id(); 558 config_options[0] = 1; // MTU 559 config_options[1] = 2; // len param 560 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 561 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->sig_id, channel->remote_cid, 0, 4, &config_options); 562 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ; 563 break; 564 case 1: 565 // connection pending. get some coffee 566 break; 567 default: 568 // channel closed 569 channel->state = L2CAP_STATE_CLOSED; 570 571 // map l2cap connection response result to BTstack status enumeration 572 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 573 574 // drop link key if security block 575 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 576 hci_drop_link_key_for_bd_addr(&channel->address); 577 } 578 579 // discard channel 580 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 581 free (channel); 582 break; 583 } 584 break; 585 586 case DISCONNECTION_REQUEST: 587 l2cap_handle_disconnect_request(channel, identifier); 588 break; 589 590 default: 591 //@TODO: implement other signaling packets 592 break; 593 } 594 break; 595 596 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP_OR_CONFIG_REQ: 597 switch (code) { 598 case CONFIGURE_RESPONSE: 599 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ; 600 break; 601 case CONFIGURE_REQUEST: 602 l2cap_signaling_handle_configure_request(channel, command); 603 channel->state = L2CAP_STATE_WAIT_CONFIG_REQ_RSP; 604 break; 605 case DISCONNECTION_REQUEST: 606 l2cap_handle_disconnect_request(channel, identifier); 607 break; 608 default: 609 //@TODO: implement other signaling packets 610 break; 611 } 612 break; 613 614 case L2CAP_STATE_WAIT_CONFIG_REQ: 615 switch (code) { 616 case CONFIGURE_REQUEST: 617 l2cap_signaling_handle_configure_request(channel, command); 618 channel->state = L2CAP_STATE_OPEN; 619 l2cap_emit_channel_opened(channel, 0); // success 620 l2cap_emit_credits(channel, 1); 621 break; 622 case DISCONNECTION_REQUEST: 623 l2cap_handle_disconnect_request(channel, identifier); 624 break; 625 default: 626 //@TODO: implement other signaling packets 627 break; 628 } 629 break; 630 631 case L2CAP_STATE_WAIT_CONFIG_REQ_RSP: 632 switch (code) { 633 case CONFIGURE_RESPONSE: 634 channel->state = L2CAP_STATE_OPEN; 635 l2cap_emit_channel_opened(channel, 0); // success 636 l2cap_emit_credits(channel, 1); 637 break; 638 case DISCONNECTION_REQUEST: 639 l2cap_handle_disconnect_request(channel, identifier); 640 break; 641 default: 642 //@TODO: implement other signaling packets 643 break; 644 } 645 break; 646 647 case L2CAP_STATE_WAIT_DISCONNECT: 648 switch (code) { 649 case DISCONNECTION_RESPONSE: 650 l2cap_finialize_channel_close(channel); 651 break; 652 case DISCONNECTION_REQUEST: 653 l2cap_handle_disconnect_request(channel, identifier); 654 break; 655 default: 656 //@TODO: implement other signaling packets 657 break; 658 } 659 break; 660 661 case L2CAP_STATE_CLOSED: 662 // @TODO handle incoming requests 663 break; 664 665 case L2CAP_STATE_OPEN: 666 switch (code) { 667 case DISCONNECTION_REQUEST: 668 l2cap_handle_disconnect_request(channel, identifier); 669 break; 670 default: 671 //@TODO: implement other signaling packets, e.g. re-configure 672 break; 673 } 674 break; 675 default: 676 break; 677 } 678 // log_dbg("new state %u\n", channel->state); 679 } 680 681 682 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 683 684 // get code, signalind identifier and command len 685 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 686 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 687 uint16_t len = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 688 689 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 690 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 691 return; 692 } 693 694 // general commands without an assigned channel 695 switch(code) { 696 697 case CONNECTION_REQUEST: { 698 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 699 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 700 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 701 break; 702 } 703 704 case ECHO_REQUEST: { 705 // send back packet 706 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, len, &command[L2CAP_SIGNALING_COMMAND_DATA_OFFSET]); 707 break; 708 } 709 710 case INFORMATION_REQUEST: { 711 // we neither support connectionless L2CAP data nor support any flow control modes yet 712 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 713 if (infoType == 2) { 714 uint32_t features = 0; 715 // extended features request supported, however no features present 716 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, 4, &features); 717 } else { 718 // all other types are not supported 719 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 720 } 721 break;; 722 } 723 724 default: 725 break; 726 } 727 728 729 // Get potential destination CID 730 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 731 732 // Find channel for this sig_id and connection handle 733 linked_item_t *it; 734 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 735 l2cap_channel_t * channel = (l2cap_channel_t *) it; 736 if (channel->handle == handle) { 737 if (code & 1) { 738 // match odd commands by previous signaling identifier 739 if (channel->sig_id == sig_id) { 740 l2cap_signaling_handler_channel(channel, command); 741 break; 742 } 743 } else { 744 // match even commands by local channel id 745 if (channel->local_cid == dest_cid) { 746 l2cap_signaling_handler_channel(channel, command); 747 break; 748 } 749 } 750 } 751 } 752 } 753 754 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 755 756 // Get Channel ID 757 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 758 759 // Signaling Packet? 760 if (channel_id == 1) { 761 762 // Get Connection 763 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 764 765 uint16_t command_offset = 8; 766 while (command_offset < size) { 767 768 // handle signaling commands 769 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 770 771 // increment command_offset 772 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 773 } 774 return; 775 } 776 777 // Find channel for this channel_id and connection handle 778 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 779 if (channel) { 780 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 781 } 782 } 783 784 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 785 switch (packet_type) { 786 case HCI_EVENT_PACKET: 787 l2cap_event_handler(packet, size); 788 break; 789 case HCI_ACL_DATA_PACKET: 790 l2cap_acl_handler(packet, size); 791 break; 792 default: 793 break; 794 } 795 } 796 797 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 798 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 799 channel->state = L2CAP_STATE_CLOSED; 800 l2cap_emit_channel_closed(channel); 801 // discard channel 802 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 803 free (channel); 804 } 805 806 l2cap_service_t * l2cap_get_service(uint16_t psm){ 807 linked_item_t *it; 808 809 // close open channels 810 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 811 l2cap_service_t * service = ((l2cap_service_t *) it); 812 if ( service->psm == psm){ 813 return service; 814 }; 815 } 816 return NULL; 817 } 818 819 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 820 // check for alread registered psm // TODO: emit error event 821 l2cap_service_t *service = l2cap_get_service(psm); 822 if (service) return; 823 824 // alloc structure // TODO: emit error event 825 service = malloc(sizeof(l2cap_service_t)); 826 if (!service) return; 827 828 // fill in 829 service->psm = psm; 830 service->mtu = mtu; 831 service->connection = connection; 832 service->packet_handler = packet_handler; 833 834 // add to services list 835 linked_list_add(&l2cap_services, (linked_item_t *) service); 836 } 837 838 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 839 l2cap_service_t *service = l2cap_get_service(psm); 840 if (!service) return; 841 linked_list_remove(&l2cap_services, (linked_item_t *) service); 842 free(service); 843 } 844 845 // 846 void l2cap_close_connection(void *connection){ 847 linked_item_t *it; 848 849 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 850 l2cap_channel_t * channel; 851 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 852 channel = (l2cap_channel_t *) it; 853 if (channel->connection == connection) { 854 channel->sig_id = l2cap_next_sig_id(); 855 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->sig_id, channel->remote_cid, channel->local_cid); 856 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 857 } 858 } 859 860 // unregister services 861 it = (linked_item_t *) &l2cap_services; 862 while (it->next) { 863 l2cap_service_t * service = (l2cap_service_t *) it->next; 864 if (service->connection == connection){ 865 it->next = it->next->next; 866 free(service); 867 } else { 868 it = it->next; 869 } 870 } 871 } 872