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 #include "btstack_memory.h" 45 46 #include <stdarg.h> 47 #include <string.h> 48 49 #include <stdio.h> 50 51 // size of HCI ACL + L2CAP Header for regular data packets (8) 52 #define COMPLETE_L2CAP_HEADER (HCI_ACL_HEADER_SIZE + L2CAP_HEADER_SIZE) 53 54 // minimum signaling MTU 55 #define L2CAP_MINIMAL_MTU 48 56 #define L2CAP_DEFAULT_MTU 672 57 58 // nr of buffered acl packets in outgoing queue to get max performance 59 #define NR_BUFFERED_ACL_PACKETS 3 60 61 // used to cache l2cap rejects, echo, and informational requests 62 #define NR_PENDING_SIGNALING_RESPONSES 5 63 64 // offsets for L2CAP SIGNALING COMMANDS 65 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 66 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 67 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 68 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 69 70 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); 71 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size); 72 73 // used to cache l2cap rejects, echo, and informational requests 74 static l2cap_signaling_response_t signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; 75 static int signaling_responses_pending; 76 77 static linked_list_t l2cap_channels = NULL; 78 static linked_list_t l2cap_services = NULL; 79 static void (*packet_handler) (void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) = null_packet_handler; 80 static int new_credits_blocked = 0; 81 82 // prototypes 83 static void l2cap_finialize_channel_close(l2cap_channel_t *channel); 84 static l2cap_service_t * l2cap_get_service(uint16_t psm); 85 static void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status); 86 static void l2cap_emit_channel_closed(l2cap_channel_t *channel); 87 static void l2cap_emit_connection_request(l2cap_channel_t *channel); 88 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); 89 90 91 void l2cap_init(){ 92 93 new_credits_blocked = 0; 94 signaling_responses_pending = 0; 95 96 // 97 // register callback with HCI 98 // 99 hci_register_packet_handler(&l2cap_packet_handler); 100 } 101 102 103 /** Register L2CAP packet handlers */ 104 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 105 } 106 void l2cap_register_packet_handler(void (*handler)(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 107 packet_handler = handler; 108 } 109 110 // notify client/protocol handler 111 void l2cap_dispatch(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 112 if (channel->packet_handler) { 113 (* (channel->packet_handler))(type, channel->local_cid, data, size); 114 } else { 115 (*packet_handler)(channel->connection, type, channel->local_cid, data, size); 116 } 117 } 118 119 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 120 uint8_t event[21]; 121 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 122 event[1] = sizeof(event) - 2; 123 event[2] = status; 124 bt_flip_addr(&event[3], channel->address); 125 bt_store_16(event, 9, channel->handle); 126 bt_store_16(event, 11, channel->psm); 127 bt_store_16(event, 13, channel->local_cid); 128 bt_store_16(event, 15, channel->remote_cid); 129 bt_store_16(event, 17, channel->local_mtu); 130 bt_store_16(event, 19, channel->remote_mtu); 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_channel_closed(l2cap_channel_t *channel) { 136 uint8_t event[4]; 137 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 138 event[1] = sizeof(event) - 2; 139 bt_store_16(event, 2, channel->local_cid); 140 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 141 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 142 } 143 144 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 145 uint8_t event[16]; 146 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 147 event[1] = sizeof(event) - 2; 148 bt_flip_addr(&event[2], channel->address); 149 bt_store_16(event, 8, channel->handle); 150 bt_store_16(event, 10, channel->psm); 151 bt_store_16(event, 12, channel->local_cid); 152 bt_store_16(event, 14, channel->remote_cid); 153 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 154 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 155 } 156 157 void l2cap_emit_credits(l2cap_channel_t *channel, uint8_t credits) { 158 // track credits 159 channel->packets_granted += credits; 160 // log_info("l2cap_emit_credits for cid %u, credits given: %u (+%u)\n", channel->local_cid, channel->packets_granted, credits); 161 162 uint8_t event[5]; 163 event[0] = L2CAP_EVENT_CREDITS; 164 event[1] = sizeof(event) - 2; 165 bt_store_16(event, 2, channel->local_cid); 166 event[4] = credits; 167 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 168 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 169 } 170 171 void l2cap_block_new_credits(uint8_t blocked){ 172 new_credits_blocked = blocked; 173 } 174 175 void l2cap_hand_out_credits(void){ 176 177 if (new_credits_blocked) return; // we're told not to. used by daemon 178 179 linked_item_t *it; 180 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 181 if (!hci_number_free_acl_slots()) return; 182 l2cap_channel_t * channel = (l2cap_channel_t *) it; 183 if (channel->state != L2CAP_STATE_OPEN) continue; 184 if (hci_number_outgoing_packets(channel->handle) < NR_BUFFERED_ACL_PACKETS && channel->packets_granted == 0) { 185 l2cap_emit_credits(channel, 1); 186 } 187 } 188 } 189 190 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 191 linked_item_t *it; 192 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 193 l2cap_channel_t * channel = (l2cap_channel_t *) it; 194 if ( channel->local_cid == local_cid) { 195 return channel; 196 } 197 } 198 return NULL; 199 } 200 201 int l2cap_can_send_packet_now(uint16_t local_cid){ 202 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 203 if (!channel) return 0; 204 if (!channel->packets_granted) return 0; 205 return hci_can_send_packet_now(HCI_ACL_DATA_PACKET); 206 } 207 208 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 209 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 210 if (channel) { 211 return channel->remote_mtu; 212 } 213 return 0; 214 } 215 216 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 217 218 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 219 log_info("l2cap_send_signaling_packet, cannot send\n"); 220 return BTSTACK_ACL_BUFFERS_FULL; 221 } 222 223 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 224 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 225 va_list argptr; 226 va_start(argptr, identifier); 227 uint16_t len = l2cap_create_signaling_internal(acl_buffer, handle, cmd, identifier, argptr); 228 va_end(argptr); 229 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 230 return hci_send_acl_packet(acl_buffer, len); 231 } 232 233 uint8_t *l2cap_get_outgoing_buffer(void){ 234 return hci_get_outgoing_acl_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 235 } 236 237 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 238 239 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 240 log_info("l2cap_send_internal cid %u, cannot send\n", local_cid); 241 return BTSTACK_ACL_BUFFERS_FULL; 242 } 243 244 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 245 if (!channel) { 246 log_error("l2cap_send_internal no channel for cid %u\n", local_cid); 247 return -1; // TODO: define error 248 } 249 250 if (channel->packets_granted == 0){ 251 log_error("l2cap_send_internal cid %u, no credits!\n", local_cid); 252 return -1; // TODO: define error 253 } 254 255 --channel->packets_granted; 256 257 log_debug("l2cap_send_internal cid %u, handle %u, 1 credit used, credits left %u;\n", 258 local_cid, channel->handle, channel->packets_granted); 259 260 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 261 262 // 0 - Connection handle : PB=10 : BC=00 263 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 264 // 2 - ACL length 265 bt_store_16(acl_buffer, 2, len + 4); 266 // 4 - L2CAP packet length 267 bt_store_16(acl_buffer, 4, len + 0); 268 // 6 - L2CAP channel DEST 269 bt_store_16(acl_buffer, 6, channel->remote_cid); 270 // send 271 int err = hci_send_acl_packet(acl_buffer, len+8); 272 273 l2cap_hand_out_credits(); 274 275 return err; 276 } 277 278 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 279 280 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 281 log_info("l2cap_send_internal cid %u, cannot send\n", local_cid); 282 return BTSTACK_ACL_BUFFERS_FULL; 283 } 284 285 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 286 287 memcpy(&acl_buffer[8], data, len); 288 289 return l2cap_send_prepared(local_cid, len); 290 } 291 292 293 // MARK: L2CAP_RUN 294 // process outstanding signaling tasks 295 void l2cap_run(void){ 296 297 // check pending signaling responses 298 while (signaling_responses_pending){ 299 300 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)) break; 301 302 hci_con_handle_t handle = signaling_responses[0].handle; 303 uint8_t sig_id = signaling_responses[0].sig_id; 304 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 305 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST 306 307 switch (signaling_responses[0].code){ 308 case CONNECTION_REQUEST: 309 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 310 break; 311 case ECHO_REQUEST: 312 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 313 break; 314 case INFORMATION_REQUEST: 315 if (infoType == 2) { 316 uint32_t features = 0; 317 // extended features request supported, however no features present 318 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, 4, &features); 319 } else { 320 // all other types are not supported 321 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 322 } 323 break; 324 default: 325 // should not happen 326 break; 327 } 328 329 // remove first item 330 signaling_responses_pending--; 331 int i; 332 for (i=0; i < signaling_responses_pending; i++){ 333 signaling_responses[i] = signaling_responses[i+1]; 334 } 335 } 336 337 uint8_t config_options[4]; 338 linked_item_t *it; 339 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 340 341 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 342 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)) break; 343 344 l2cap_channel_t * channel = (l2cap_channel_t *) it; 345 346 // log_info("l2cap_run: state %u, var 0x%02x\n", channel->state, channel->state_var); 347 348 switch (channel->state){ 349 350 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 351 // send connection request - set state first 352 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 353 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 354 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 355 break; 356 357 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 358 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, channel->reason, 0); 359 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 360 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 361 btstack_memory_l2cap_channel_free(channel); 362 break; 363 364 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 365 channel->state = L2CAP_STATE_CONFIG; 366 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ; 367 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 368 break; 369 370 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 371 // success, start l2cap handshake 372 channel->local_sig_id = l2cap_next_sig_id(); 373 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 374 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 375 break; 376 377 case L2CAP_STATE_CONFIG: 378 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 379 channel->state_var &= ~L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP; 380 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP; 381 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, 0, 0, 0, NULL); 382 } 383 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 384 channel->state_var &= ~L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ; 385 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ; 386 channel->local_sig_id = l2cap_next_sig_id(); 387 config_options[0] = 1; // MTU 388 config_options[1] = 2; // len param 389 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 390 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 391 } 392 if (l2cap_channel_ready_for_open(channel)){ 393 channel->state = L2CAP_STATE_OPEN; 394 l2cap_emit_channel_opened(channel, 0); // success 395 l2cap_emit_credits(channel, 1); 396 } 397 break; 398 399 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 400 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 401 l2cap_finialize_channel_close(channel); 402 break; 403 404 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 405 channel->local_sig_id = l2cap_next_sig_id(); 406 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 407 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 408 break; 409 default: 410 break; 411 } 412 } 413 } 414 415 static uint16_t l2cap_max_l2cap_mtu(void){ 416 return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE; 417 } 418 419 // open outgoing L2CAP channel 420 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 421 bd_addr_t address, uint16_t psm, uint16_t mtu){ 422 423 // alloc structure 424 l2cap_channel_t * chan = btstack_memory_l2cap_channel_get(); 425 if (!chan) { 426 // emit error event 427 l2cap_channel_t dummy_channel; 428 BD_ADDR_COPY(dummy_channel.address, address); 429 dummy_channel.psm = psm; 430 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 431 return; 432 } 433 // limit local mtu to max acl packet length 434 if (mtu > l2cap_max_l2cap_mtu()) { 435 mtu = l2cap_max_l2cap_mtu(); 436 } 437 438 // fill in 439 BD_ADDR_COPY(chan->address, address); 440 chan->psm = psm; 441 chan->handle = 0; 442 chan->connection = connection; 443 chan->packet_handler = packet_handler; 444 chan->remote_mtu = L2CAP_MINIMAL_MTU; 445 chan->local_mtu = mtu; 446 chan->packets_granted = 0; 447 448 // set initial state 449 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 450 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 451 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 452 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 453 454 // add to connections list 455 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 456 457 l2cap_run(); 458 } 459 460 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 461 // find channel for local_cid 462 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 463 if (channel) { 464 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 465 } 466 // process 467 l2cap_run(); 468 } 469 470 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 471 linked_item_t *it = (linked_item_t *) &l2cap_channels; 472 while (it->next){ 473 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 474 if ( ! BD_ADDR_CMP( channel->address, address) ){ 475 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 476 // failure, forward error code 477 l2cap_emit_channel_opened(channel, status); 478 // discard channel 479 it->next = it->next->next; 480 btstack_memory_l2cap_channel_free(channel); 481 } 482 } else { 483 it = it->next; 484 } 485 } 486 } 487 488 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 489 linked_item_t *it; 490 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 491 l2cap_channel_t * channel = (l2cap_channel_t *) it; 492 if ( ! BD_ADDR_CMP( channel->address, address) ){ 493 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 494 // success, start l2cap handshake 495 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 496 channel->handle = handle; 497 channel->local_cid = l2cap_next_local_cid(); 498 } 499 } 500 } 501 // process 502 l2cap_run(); 503 } 504 505 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 506 507 bd_addr_t address; 508 hci_con_handle_t handle; 509 l2cap_channel_t * channel; 510 linked_item_t *it; 511 int hci_con_used; 512 513 switch(packet[0]){ 514 515 // handle connection complete events 516 case HCI_EVENT_CONNECTION_COMPLETE: 517 bt_flip_addr(address, &packet[5]); 518 if (packet[2] == 0){ 519 handle = READ_BT_16(packet, 3); 520 l2cap_handle_connection_success_for_addr(address, handle); 521 } else { 522 l2cap_handle_connection_failed_for_addr(address, packet[2]); 523 } 524 break; 525 526 // handle successful create connection cancel command 527 case HCI_EVENT_COMMAND_COMPLETE: 528 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 529 if (packet[5] == 0){ 530 bt_flip_addr(address, &packet[6]); 531 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 532 l2cap_handle_connection_failed_for_addr(address, 0x16); 533 } 534 } 535 l2cap_run(); // try sending signaling packets first 536 break; 537 538 case HCI_EVENT_COMMAND_STATUS: 539 l2cap_run(); // try sending signaling packets first 540 break; 541 542 // handle disconnection complete events 543 case HCI_EVENT_DISCONNECTION_COMPLETE: 544 // send l2cap disconnect events for all channels on this handle 545 handle = READ_BT_16(packet, 3); 546 it = (linked_item_t *) &l2cap_channels; 547 while (it->next){ 548 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 549 if ( channel->handle == handle ){ 550 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 551 it->next = it->next->next; 552 l2cap_emit_channel_closed(channel); 553 btstack_memory_l2cap_channel_free(channel); 554 } else { 555 it = it->next; 556 } 557 } 558 break; 559 560 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 561 l2cap_run(); // try sending signaling packets first 562 l2cap_hand_out_credits(); 563 break; 564 565 // HCI Connection Timeouts 566 case L2CAP_EVENT_TIMEOUT_CHECK: 567 handle = READ_BT_16(packet, 2); 568 if (hci_authentication_active_for_handle(handle)) break; 569 hci_con_used = 0; 570 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 571 channel = (l2cap_channel_t *) it; 572 if (channel->handle == handle) { 573 hci_con_used = 1; 574 } 575 } 576 if (hci_con_used) break; 577 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 578 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 579 break; 580 581 case DAEMON_EVENT_HCI_PACKET_SENT: 582 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 583 channel = (l2cap_channel_t *) it; 584 if (channel->packet_handler) { 585 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 586 } 587 } 588 break; 589 590 default: 591 break; 592 } 593 594 // pass on 595 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 596 } 597 598 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 599 channel->remote_sig_id = identifier; 600 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 601 l2cap_run(); 602 } 603 604 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 605 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 606 signaling_responses[signaling_responses_pending].handle = handle; 607 signaling_responses[signaling_responses_pending].code = code; 608 signaling_responses[signaling_responses_pending].sig_id = sig_id; 609 signaling_responses[signaling_responses_pending].data = data; 610 signaling_responses_pending++; 611 l2cap_run(); 612 } 613 } 614 615 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 616 617 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid %u\n", handle, psm, source_cid); 618 l2cap_service_t *service = l2cap_get_service(psm); 619 if (!service) { 620 // 0x0002 PSM not supported 621 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 622 return; 623 } 624 625 hci_connection_t * hci_connection = connection_for_handle( handle ); 626 if (!hci_connection) { 627 // 628 log_error("no hci_connection for handle %u\n", handle); 629 return; 630 } 631 // alloc structure 632 // log_info("l2cap_handle_connection_request register channel\n"); 633 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 634 if (!channel){ 635 // 0x0004 No resources available 636 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 637 return; 638 } 639 640 // fill in 641 BD_ADDR_COPY(channel->address, hci_connection->address); 642 channel->psm = psm; 643 channel->handle = handle; 644 channel->connection = service->connection; 645 channel->packet_handler = service->packet_handler; 646 channel->local_cid = l2cap_next_local_cid(); 647 channel->remote_cid = source_cid; 648 channel->local_mtu = service->mtu; 649 channel->remote_mtu = L2CAP_DEFAULT_MTU; 650 channel->packets_granted = 0; 651 channel->remote_sig_id = sig_id; 652 653 // limit local mtu to max acl packet length 654 if (channel->local_mtu > l2cap_max_l2cap_mtu()) { 655 channel->local_mtu = l2cap_max_l2cap_mtu(); 656 } 657 658 // set initial state 659 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 660 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 661 662 // add to connections list 663 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 664 665 // emit incoming connection request 666 l2cap_emit_connection_request(channel); 667 } 668 669 void l2cap_accept_connection_internal(uint16_t local_cid){ 670 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 671 if (!channel) { 672 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 673 return; 674 } 675 676 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 677 678 // process 679 l2cap_run(); 680 } 681 682 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 683 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 684 if (!channel) { 685 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 686 return; 687 } 688 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 689 channel->reason = reason; 690 l2cap_run(); 691 } 692 693 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 694 695 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 696 697 // accept the other's configuration options 698 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 699 uint16_t pos = 8; 700 while (pos < end_pos){ 701 uint8_t type = command[pos++]; 702 uint8_t length = command[pos++]; 703 // MTU { type(8): 1, len(8):2, MTU(16) } 704 if ((type & 0x7f) == 1 && length == 2){ 705 channel->remote_mtu = READ_BT_16(command, pos); 706 // log_info("l2cap cid %u, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 707 } 708 pos += length; 709 } 710 } 711 712 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 713 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 714 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 715 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 716 return 1; 717 } 718 719 720 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 721 722 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 723 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 724 uint16_t result = 0; 725 726 log_info("signaling handler code %u, state %u\n", code, channel->state); 727 728 // handle DISCONNECT REQUESTS seperately 729 if (code == DISCONNECTION_REQUEST){ 730 switch (channel->state){ 731 case L2CAP_STATE_CONFIG: 732 case L2CAP_STATE_OPEN: 733 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 734 case L2CAP_STATE_WAIT_DISCONNECT: 735 l2cap_handle_disconnect_request(channel, identifier); 736 break; 737 738 default: 739 // ignore in other states 740 break; 741 } 742 return; 743 } 744 745 switch (channel->state) { 746 747 case L2CAP_STATE_WAIT_CONNECT_RSP: 748 switch (code){ 749 case CONNECTION_RESPONSE: 750 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 751 switch (result) { 752 case 0: 753 // successful connection 754 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 755 channel->state = L2CAP_STATE_CONFIG; 756 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ; 757 break; 758 case 1: 759 // connection pending. get some coffee 760 break; 761 default: 762 // channel closed 763 channel->state = L2CAP_STATE_CLOSED; 764 765 // map l2cap connection response result to BTstack status enumeration 766 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 767 768 // drop link key if security block 769 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 770 hci_drop_link_key_for_bd_addr(&channel->address); 771 } 772 773 // discard channel 774 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 775 btstack_memory_l2cap_channel_free(channel); 776 break; 777 } 778 break; 779 780 default: 781 //@TODO: implement other signaling packets 782 break; 783 } 784 break; 785 786 case L2CAP_STATE_CONFIG: 787 switch (code) { 788 case CONFIGURE_REQUEST: 789 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ; 790 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP; 791 l2cap_signaling_handle_configure_request(channel, command); 792 break; 793 case CONFIGURE_RESPONSE: 794 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP; 795 break; 796 default: 797 break; 798 } 799 if (l2cap_channel_ready_for_open(channel)){ 800 // for open: 801 channel->state = L2CAP_STATE_OPEN; 802 l2cap_emit_channel_opened(channel, 0); 803 l2cap_emit_credits(channel, 1); 804 } 805 break; 806 807 case L2CAP_STATE_WAIT_DISCONNECT: 808 switch (code) { 809 case DISCONNECTION_RESPONSE: 810 l2cap_finialize_channel_close(channel); 811 break; 812 default: 813 //@TODO: implement other signaling packets 814 break; 815 } 816 break; 817 818 case L2CAP_STATE_CLOSED: 819 // @TODO handle incoming requests 820 break; 821 822 case L2CAP_STATE_OPEN: 823 //@TODO: implement other signaling packets, e.g. re-configure 824 break; 825 default: 826 break; 827 } 828 // log_info("new state %u\n", channel->state); 829 } 830 831 832 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 833 834 // get code, signalind identifier and command len 835 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 836 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 837 838 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 839 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 840 return; 841 } 842 843 // general commands without an assigned channel 844 switch(code) { 845 846 case CONNECTION_REQUEST: { 847 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 848 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 849 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 850 return; 851 } 852 853 case ECHO_REQUEST: 854 l2cap_register_signaling_response(handle, code, sig_id, 0); 855 return; 856 857 case INFORMATION_REQUEST: { 858 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 859 l2cap_register_signaling_response(handle, code, sig_id, infoType); 860 return; 861 } 862 863 default: 864 break; 865 } 866 867 868 // Get potential destination CID 869 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 870 871 // Find channel for this sig_id and connection handle 872 linked_item_t *it; 873 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 874 l2cap_channel_t * channel = (l2cap_channel_t *) it; 875 if (channel->handle == handle) { 876 if (code & 1) { 877 // match odd commands (responses) by previous signaling identifier 878 if (channel->local_sig_id == sig_id) { 879 l2cap_signaling_handler_channel(channel, command); 880 break; 881 } 882 } else { 883 // match even commands (requests) by local channel id 884 if (channel->local_cid == dest_cid) { 885 l2cap_signaling_handler_channel(channel, command); 886 break; 887 } 888 } 889 } 890 } 891 } 892 893 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 894 895 // Get Channel ID 896 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 897 898 // Signaling Packet? 899 if (channel_id == 1) { 900 901 // Get Connection 902 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 903 904 uint16_t command_offset = 8; 905 while (command_offset < size) { 906 907 // handle signaling commands 908 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 909 910 // increment command_offset 911 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 912 } 913 914 l2cap_run(); 915 916 return; 917 } 918 919 // Find channel for this channel_id and connection handle 920 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 921 if (channel) { 922 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 923 } 924 } 925 926 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 927 switch (packet_type) { 928 case HCI_EVENT_PACKET: 929 l2cap_event_handler(packet, size); 930 break; 931 case HCI_ACL_DATA_PACKET: 932 l2cap_acl_handler(packet, size); 933 break; 934 default: 935 break; 936 } 937 } 938 939 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 940 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 941 channel->state = L2CAP_STATE_CLOSED; 942 l2cap_emit_channel_closed(channel); 943 // discard channel 944 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 945 btstack_memory_l2cap_channel_free(channel); 946 } 947 948 l2cap_service_t * l2cap_get_service(uint16_t psm){ 949 linked_item_t *it; 950 951 // close open channels 952 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 953 l2cap_service_t * service = ((l2cap_service_t *) it); 954 if ( service->psm == psm){ 955 return service; 956 }; 957 } 958 return NULL; 959 } 960 961 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 962 // check for alread registered psm 963 // TODO: emit error event 964 l2cap_service_t *service = l2cap_get_service(psm); 965 if (service) { 966 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 967 return; 968 } 969 970 // alloc structure 971 // TODO: emit error event 972 service = btstack_memory_l2cap_service_get(); 973 if (!service) { 974 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 975 return; 976 } 977 978 // fill in 979 service->psm = psm; 980 service->mtu = mtu; 981 service->connection = connection; 982 service->packet_handler = packet_handler; 983 984 // add to services list 985 linked_list_add(&l2cap_services, (linked_item_t *) service); 986 } 987 988 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 989 l2cap_service_t *service = l2cap_get_service(psm); 990 if (!service) return; 991 linked_list_remove(&l2cap_services, (linked_item_t *) service); 992 btstack_memory_l2cap_service_free(service); 993 } 994 995 // 996 void l2cap_close_connection(void *connection){ 997 linked_item_t *it; 998 999 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 1000 l2cap_channel_t * channel; 1001 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1002 channel = (l2cap_channel_t *) it; 1003 if (channel->connection == connection) { 1004 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1005 } 1006 } 1007 1008 // unregister services 1009 it = (linked_item_t *) &l2cap_services; 1010 while (it->next) { 1011 l2cap_service_t * service = (l2cap_service_t *) it->next; 1012 if (service->connection == connection){ 1013 it->next = it->next->next; 1014 btstack_memory_l2cap_service_free(service); 1015 } else { 1016 it = it->next; 1017 } 1018 } 1019 1020 // process 1021 l2cap_run(); 1022 } 1023