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 // nr of buffered acl packets in outgoing queue to get max performance 52 #define NR_BUFFERED_ACL_PACKETS 3 53 54 // used to cache l2cap rejects, echo, and informational requests 55 #define NR_PENDING_SIGNALING_RESPONSES 3 56 57 // offsets for L2CAP SIGNALING COMMANDS 58 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 59 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 60 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 61 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 62 63 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); 64 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size); 65 66 // used to cache l2cap rejects, echo, and informational requests 67 static l2cap_signaling_response_t signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; 68 static int signaling_responses_pending; 69 70 static linked_list_t l2cap_channels = NULL; 71 static linked_list_t l2cap_services = NULL; 72 static void (*packet_handler) (void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) = null_packet_handler; 73 static int new_credits_blocked = 0; 74 75 // prototypes 76 static void l2cap_finialize_channel_close(l2cap_channel_t *channel); 77 static l2cap_service_t * l2cap_get_service(uint16_t psm); 78 static void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status); 79 static void l2cap_emit_channel_closed(l2cap_channel_t *channel); 80 static void l2cap_emit_connection_request(l2cap_channel_t *channel); 81 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); 82 83 84 void l2cap_init(){ 85 new_credits_blocked = 0; 86 signaling_responses_pending = 0; 87 88 l2cap_channels = NULL; 89 l2cap_services = NULL; 90 91 packet_handler = null_packet_handler; 92 93 // 94 // register callback with HCI 95 // 96 hci_register_packet_handler(&l2cap_packet_handler); 97 hci_connectable_control(0); // no services yet 98 } 99 100 101 /** Register L2CAP packet handlers */ 102 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 103 } 104 void l2cap_register_packet_handler(void (*handler)(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 105 packet_handler = handler; 106 } 107 108 // notify client/protocol handler 109 void l2cap_dispatch(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 110 if (channel->packet_handler) { 111 (* (channel->packet_handler))(type, channel->local_cid, data, size); 112 } else { 113 (*packet_handler)(channel->connection, type, channel->local_cid, data, size); 114 } 115 } 116 117 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 118 uint8_t event[21]; 119 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 120 event[1] = sizeof(event) - 2; 121 event[2] = status; 122 bt_flip_addr(&event[3], channel->address); 123 bt_store_16(event, 9, channel->handle); 124 bt_store_16(event, 11, channel->psm); 125 bt_store_16(event, 13, channel->local_cid); 126 bt_store_16(event, 15, channel->remote_cid); 127 bt_store_16(event, 17, channel->local_mtu); 128 bt_store_16(event, 19, channel->remote_mtu); 129 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 130 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 131 } 132 133 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 134 uint8_t event[4]; 135 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 136 event[1] = sizeof(event) - 2; 137 bt_store_16(event, 2, channel->local_cid); 138 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 139 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 140 } 141 142 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 143 uint8_t event[16]; 144 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 145 event[1] = sizeof(event) - 2; 146 bt_flip_addr(&event[2], channel->address); 147 bt_store_16(event, 8, channel->handle); 148 bt_store_16(event, 10, channel->psm); 149 bt_store_16(event, 12, channel->local_cid); 150 bt_store_16(event, 14, channel->remote_cid); 151 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 152 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 153 } 154 155 static void l2cap_emit_service_registered(void *connection, uint8_t status, uint16_t psm){ 156 uint8_t event[5]; 157 event[0] = L2CAP_EVENT_SERVICE_REGISTERED; 158 event[1] = sizeof(event) - 2; 159 event[2] = status; 160 bt_store_16(event, 3, psm); 161 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 162 (*packet_handler)(connection, HCI_EVENT_PACKET, 0, event, sizeof(event)); 163 } 164 165 void l2cap_emit_credits(l2cap_channel_t *channel, uint8_t credits) { 166 // track credits 167 channel->packets_granted += credits; 168 // log_info("l2cap_emit_credits for cid %u, credits given: %u (+%u)\n", channel->local_cid, channel->packets_granted, credits); 169 170 uint8_t event[5]; 171 event[0] = L2CAP_EVENT_CREDITS; 172 event[1] = sizeof(event) - 2; 173 bt_store_16(event, 2, channel->local_cid); 174 event[4] = credits; 175 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 176 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 177 } 178 179 void l2cap_block_new_credits(uint8_t blocked){ 180 new_credits_blocked = blocked; 181 } 182 183 void l2cap_hand_out_credits(void){ 184 185 if (new_credits_blocked) return; // we're told not to. used by daemon 186 187 linked_item_t *it; 188 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 189 if (!hci_number_free_acl_slots()) return; 190 l2cap_channel_t * channel = (l2cap_channel_t *) it; 191 if (channel->state != L2CAP_STATE_OPEN) continue; 192 if (hci_number_outgoing_packets(channel->handle) < NR_BUFFERED_ACL_PACKETS && channel->packets_granted == 0) { 193 l2cap_emit_credits(channel, 1); 194 } 195 } 196 } 197 198 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 199 linked_item_t *it; 200 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 201 l2cap_channel_t * channel = (l2cap_channel_t *) it; 202 if ( channel->local_cid == local_cid) { 203 return channel; 204 } 205 } 206 return NULL; 207 } 208 209 int l2cap_can_send_packet_now(uint16_t local_cid){ 210 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 211 if (!channel) return 0; 212 if (!channel->packets_granted) return 0; 213 return hci_can_send_packet_now(HCI_ACL_DATA_PACKET); 214 } 215 216 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 217 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 218 if (channel) { 219 return channel->remote_mtu; 220 } 221 return 0; 222 } 223 224 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 225 226 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 227 log_info("l2cap_send_signaling_packet, cannot send\n"); 228 return BTSTACK_ACL_BUFFERS_FULL; 229 } 230 231 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 232 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 233 va_list argptr; 234 va_start(argptr, identifier); 235 uint16_t len = l2cap_create_signaling_internal(acl_buffer, handle, cmd, identifier, argptr); 236 va_end(argptr); 237 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 238 return hci_send_acl_packet(acl_buffer, len); 239 } 240 241 uint8_t *l2cap_get_outgoing_buffer(void){ 242 return hci_get_outgoing_acl_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 243 } 244 245 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 246 247 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 248 log_info("l2cap_send_internal cid %u, cannot send\n", local_cid); 249 return BTSTACK_ACL_BUFFERS_FULL; 250 } 251 252 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 253 if (!channel) { 254 log_error("l2cap_send_internal no channel for cid %u\n", local_cid); 255 return -1; // TODO: define error 256 } 257 258 if (channel->packets_granted == 0){ 259 log_error("l2cap_send_internal cid %u, no credits!\n", local_cid); 260 return -1; // TODO: define error 261 } 262 263 --channel->packets_granted; 264 265 log_debug("l2cap_send_internal cid %u, handle %u, 1 credit used, credits left %u;\n", 266 local_cid, channel->handle, channel->packets_granted); 267 268 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 269 270 // 0 - Connection handle : PB=10 : BC=00 271 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 272 // 2 - ACL length 273 bt_store_16(acl_buffer, 2, len + 4); 274 // 4 - L2CAP packet length 275 bt_store_16(acl_buffer, 4, len + 0); 276 // 6 - L2CAP channel DEST 277 bt_store_16(acl_buffer, 6, channel->remote_cid); 278 // send 279 int err = hci_send_acl_packet(acl_buffer, len+8); 280 281 l2cap_hand_out_credits(); 282 283 return err; 284 } 285 286 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 287 288 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 289 log_info("l2cap_send_internal cid %u, cannot send\n", local_cid); 290 return BTSTACK_ACL_BUFFERS_FULL; 291 } 292 293 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 294 295 memcpy(&acl_buffer[8], data, len); 296 297 return l2cap_send_prepared(local_cid, len); 298 } 299 300 301 // MARK: L2CAP_RUN 302 // process outstanding signaling tasks 303 void l2cap_run(void){ 304 305 // check pending signaling responses 306 while (signaling_responses_pending){ 307 308 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)) break; 309 310 hci_con_handle_t handle = signaling_responses[0].handle; 311 uint8_t sig_id = signaling_responses[0].sig_id; 312 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 313 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST 314 315 switch (signaling_responses[0].code){ 316 case CONNECTION_REQUEST: 317 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 318 break; 319 case ECHO_REQUEST: 320 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 321 break; 322 case INFORMATION_REQUEST: 323 if (infoType == 2) { 324 uint32_t features = 0; 325 // extended features request supported, however no features present 326 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, 4, &features); 327 } else { 328 // all other types are not supported 329 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 330 } 331 break; 332 default: 333 // should not happen 334 break; 335 } 336 337 // remove first item 338 signaling_responses_pending--; 339 int i; 340 for (i=0; i < signaling_responses_pending; i++){ 341 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 342 } 343 } 344 345 uint8_t config_options[4]; 346 linked_item_t *it; 347 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 348 349 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 350 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)) break; 351 352 l2cap_channel_t * channel = (l2cap_channel_t *) it; 353 354 // log_info("l2cap_run: state %u, var 0x%02x\n", channel->state, channel->state_var); 355 356 357 switch (channel->state){ 358 359 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 360 // send connection request - set state first 361 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 362 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 363 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 364 break; 365 366 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 367 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, channel->reason, 0); 368 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 369 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 370 btstack_memory_l2cap_channel_free(channel); 371 break; 372 373 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 374 channel->state = L2CAP_STATE_CONFIG; 375 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ; 376 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 377 break; 378 379 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 380 // success, start l2cap handshake 381 channel->local_sig_id = l2cap_next_sig_id(); 382 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 383 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 384 break; 385 386 case L2CAP_STATE_CONFIG: 387 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 388 channel->state_var &= ~L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP; 389 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP; 390 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, 0, 0, 0, NULL); 391 } 392 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 393 channel->state_var &= ~L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ; 394 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ; 395 channel->local_sig_id = l2cap_next_sig_id(); 396 config_options[0] = 1; // MTU 397 config_options[1] = 2; // len param 398 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 399 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 400 } 401 if (l2cap_channel_ready_for_open(channel)){ 402 channel->state = L2CAP_STATE_OPEN; 403 l2cap_emit_channel_opened(channel, 0); // success 404 l2cap_emit_credits(channel, 1); 405 } 406 break; 407 408 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 409 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 410 l2cap_finialize_channel_close(channel); 411 break; 412 413 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 414 channel->local_sig_id = l2cap_next_sig_id(); 415 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 416 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 417 break; 418 default: 419 break; 420 } 421 } 422 } 423 424 uint16_t l2cap_max_mtu(void){ 425 return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE; 426 } 427 428 // open outgoing L2CAP channel 429 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 430 bd_addr_t address, uint16_t psm, uint16_t mtu){ 431 432 // alloc structure 433 l2cap_channel_t * chan = btstack_memory_l2cap_channel_get(); 434 if (!chan) { 435 // emit error event 436 l2cap_channel_t dummy_channel; 437 BD_ADDR_COPY(dummy_channel.address, address); 438 dummy_channel.psm = psm; 439 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 440 return; 441 } 442 // limit local mtu to max acl packet length 443 if (mtu > l2cap_max_mtu()) { 444 mtu = l2cap_max_mtu(); 445 } 446 447 // fill in 448 BD_ADDR_COPY(chan->address, address); 449 chan->psm = psm; 450 chan->handle = 0; 451 chan->connection = connection; 452 chan->packet_handler = packet_handler; 453 chan->remote_mtu = L2CAP_MINIMAL_MTU; 454 chan->local_mtu = mtu; 455 chan->packets_granted = 0; 456 457 // set initial state 458 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 459 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 460 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 461 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 462 463 // add to connections list 464 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 465 466 l2cap_run(); 467 } 468 469 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 470 // find channel for local_cid 471 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 472 if (channel) { 473 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 474 } 475 // process 476 l2cap_run(); 477 } 478 479 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 480 linked_item_t *it = (linked_item_t *) &l2cap_channels; 481 while (it->next){ 482 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 483 if ( ! BD_ADDR_CMP( channel->address, address) ){ 484 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 485 // failure, forward error code 486 l2cap_emit_channel_opened(channel, status); 487 // discard channel 488 it->next = it->next->next; 489 btstack_memory_l2cap_channel_free(channel); 490 } 491 } else { 492 it = it->next; 493 } 494 } 495 } 496 497 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 498 linked_item_t *it; 499 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 500 l2cap_channel_t * channel = (l2cap_channel_t *) it; 501 if ( ! BD_ADDR_CMP( channel->address, address) ){ 502 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 503 // success, start l2cap handshake 504 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 505 channel->handle = handle; 506 channel->local_cid = l2cap_next_local_cid(); 507 } 508 } 509 } 510 // process 511 l2cap_run(); 512 } 513 514 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 515 516 bd_addr_t address; 517 hci_con_handle_t handle; 518 l2cap_channel_t * channel; 519 linked_item_t *it; 520 int hci_con_used; 521 522 switch(packet[0]){ 523 524 // handle connection complete events 525 case HCI_EVENT_CONNECTION_COMPLETE: 526 bt_flip_addr(address, &packet[5]); 527 if (packet[2] == 0){ 528 handle = READ_BT_16(packet, 3); 529 l2cap_handle_connection_success_for_addr(address, handle); 530 } else { 531 l2cap_handle_connection_failed_for_addr(address, packet[2]); 532 } 533 break; 534 535 // handle successful create connection cancel command 536 case HCI_EVENT_COMMAND_COMPLETE: 537 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 538 if (packet[5] == 0){ 539 bt_flip_addr(address, &packet[6]); 540 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 541 l2cap_handle_connection_failed_for_addr(address, 0x16); 542 } 543 } 544 l2cap_run(); // try sending signaling packets first 545 break; 546 547 case HCI_EVENT_COMMAND_STATUS: 548 l2cap_run(); // try sending signaling packets first 549 break; 550 551 // handle disconnection complete events 552 case HCI_EVENT_DISCONNECTION_COMPLETE: 553 // send l2cap disconnect events for all channels on this handle 554 handle = READ_BT_16(packet, 3); 555 it = (linked_item_t *) &l2cap_channels; 556 while (it->next){ 557 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 558 if ( channel->handle == handle ){ 559 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 560 it->next = it->next->next; 561 l2cap_emit_channel_closed(channel); 562 btstack_memory_l2cap_channel_free(channel); 563 } else { 564 it = it->next; 565 } 566 } 567 break; 568 569 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 570 l2cap_run(); // try sending signaling packets first 571 l2cap_hand_out_credits(); 572 break; 573 574 // HCI Connection Timeouts 575 case L2CAP_EVENT_TIMEOUT_CHECK: 576 handle = READ_BT_16(packet, 2); 577 if (hci_authentication_active_for_handle(handle)) break; 578 hci_con_used = 0; 579 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 580 channel = (l2cap_channel_t *) it; 581 if (channel->handle == handle) { 582 hci_con_used = 1; 583 } 584 } 585 if (hci_con_used) break; 586 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 587 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 588 break; 589 590 case DAEMON_EVENT_HCI_PACKET_SENT: 591 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 592 channel = (l2cap_channel_t *) it; 593 if (channel->packet_handler) { 594 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 595 } 596 } 597 break; 598 599 default: 600 break; 601 } 602 603 // pass on 604 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 605 } 606 607 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 608 channel->remote_sig_id = identifier; 609 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 610 l2cap_run(); 611 } 612 613 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 614 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 615 signaling_responses[signaling_responses_pending].handle = handle; 616 signaling_responses[signaling_responses_pending].code = code; 617 signaling_responses[signaling_responses_pending].sig_id = sig_id; 618 signaling_responses[signaling_responses_pending].data = data; 619 signaling_responses_pending++; 620 l2cap_run(); 621 } 622 } 623 624 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 625 626 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid %u\n", handle, psm, source_cid); 627 l2cap_service_t *service = l2cap_get_service(psm); 628 if (!service) { 629 // 0x0002 PSM not supported 630 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 631 return; 632 } 633 634 hci_connection_t * hci_connection = connection_for_handle( handle ); 635 if (!hci_connection) { 636 // 637 log_error("no hci_connection for handle %u\n", handle); 638 return; 639 } 640 // alloc structure 641 // log_info("l2cap_handle_connection_request register channel\n"); 642 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 643 if (!channel){ 644 // 0x0004 No resources available 645 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 646 return; 647 } 648 649 // fill in 650 BD_ADDR_COPY(channel->address, hci_connection->address); 651 channel->psm = psm; 652 channel->handle = handle; 653 channel->connection = service->connection; 654 channel->packet_handler = service->packet_handler; 655 channel->local_cid = l2cap_next_local_cid(); 656 channel->remote_cid = source_cid; 657 channel->local_mtu = service->mtu; 658 channel->remote_mtu = L2CAP_DEFAULT_MTU; 659 channel->packets_granted = 0; 660 channel->remote_sig_id = sig_id; 661 662 // limit local mtu to max acl packet length 663 if (channel->local_mtu > l2cap_max_mtu()) { 664 channel->local_mtu = l2cap_max_mtu(); 665 } 666 667 // set initial state 668 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 669 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 670 671 // add to connections list 672 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 673 674 // emit incoming connection request 675 l2cap_emit_connection_request(channel); 676 } 677 678 void l2cap_accept_connection_internal(uint16_t local_cid){ 679 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 680 if (!channel) { 681 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 682 return; 683 } 684 685 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 686 687 // process 688 l2cap_run(); 689 } 690 691 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 692 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 693 if (!channel) { 694 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 695 return; 696 } 697 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 698 channel->reason = reason; 699 l2cap_run(); 700 } 701 702 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 703 704 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 705 706 // accept the other's configuration options 707 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 708 uint16_t pos = 8; 709 while (pos < end_pos){ 710 uint8_t type = command[pos++]; 711 uint8_t length = command[pos++]; 712 // MTU { type(8): 1, len(8):2, MTU(16) } 713 if ((type & 0x7f) == 1 && length == 2){ 714 channel->remote_mtu = READ_BT_16(command, pos); 715 // log_info("l2cap cid %u, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 716 } 717 pos += length; 718 } 719 } 720 721 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 722 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 723 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 724 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 725 return 1; 726 } 727 728 729 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 730 731 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 732 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 733 uint16_t result = 0; 734 735 log_info("L2CAP signaling handler code %u, state %u\n", code, channel->state); 736 737 // handle DISCONNECT REQUESTS seperately 738 if (code == DISCONNECTION_REQUEST){ 739 switch (channel->state){ 740 case L2CAP_STATE_CONFIG: 741 case L2CAP_STATE_OPEN: 742 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 743 case L2CAP_STATE_WAIT_DISCONNECT: 744 l2cap_handle_disconnect_request(channel, identifier); 745 break; 746 747 default: 748 // ignore in other states 749 break; 750 } 751 return; 752 } 753 754 // @STATEMACHINE(l2cap) 755 switch (channel->state) { 756 757 case L2CAP_STATE_WAIT_CONNECT_RSP: 758 switch (code){ 759 case CONNECTION_RESPONSE: 760 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 761 switch (result) { 762 case 0: 763 // successful connection 764 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 765 channel->state = L2CAP_STATE_CONFIG; 766 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ; 767 break; 768 case 1: 769 // connection pending. get some coffee 770 break; 771 default: 772 // channel closed 773 channel->state = L2CAP_STATE_CLOSED; 774 775 // map l2cap connection response result to BTstack status enumeration 776 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 777 778 // drop link key if security block 779 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 780 hci_drop_link_key_for_bd_addr(&channel->address); 781 } 782 783 // discard channel 784 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 785 btstack_memory_l2cap_channel_free(channel); 786 break; 787 } 788 break; 789 790 default: 791 //@TODO: implement other signaling packets 792 break; 793 } 794 break; 795 796 case L2CAP_STATE_CONFIG: 797 switch (code) { 798 case CONFIGURE_REQUEST: 799 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ; 800 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP; 801 l2cap_signaling_handle_configure_request(channel, command); 802 break; 803 case CONFIGURE_RESPONSE: 804 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP; 805 break; 806 default: 807 break; 808 } 809 if (l2cap_channel_ready_for_open(channel)){ 810 // for open: 811 channel->state = L2CAP_STATE_OPEN; 812 l2cap_emit_channel_opened(channel, 0); 813 l2cap_emit_credits(channel, 1); 814 } 815 break; 816 817 case L2CAP_STATE_WAIT_DISCONNECT: 818 switch (code) { 819 case DISCONNECTION_RESPONSE: 820 l2cap_finialize_channel_close(channel); 821 break; 822 default: 823 //@TODO: implement other signaling packets 824 break; 825 } 826 break; 827 828 case L2CAP_STATE_CLOSED: 829 // @TODO handle incoming requests 830 break; 831 832 case L2CAP_STATE_OPEN: 833 //@TODO: implement other signaling packets, e.g. re-configure 834 break; 835 default: 836 break; 837 } 838 // log_info("new state %u\n", channel->state); 839 } 840 841 842 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 843 844 // get code, signalind identifier and command len 845 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 846 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 847 848 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 849 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 850 return; 851 } 852 853 // general commands without an assigned channel 854 switch(code) { 855 856 case CONNECTION_REQUEST: { 857 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 858 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 859 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 860 return; 861 } 862 863 case ECHO_REQUEST: 864 l2cap_register_signaling_response(handle, code, sig_id, 0); 865 return; 866 867 case INFORMATION_REQUEST: { 868 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 869 l2cap_register_signaling_response(handle, code, sig_id, infoType); 870 return; 871 } 872 873 default: 874 break; 875 } 876 877 878 // Get potential destination CID 879 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 880 881 // Find channel for this sig_id and connection handle 882 linked_item_t *it; 883 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 884 l2cap_channel_t * channel = (l2cap_channel_t *) it; 885 if (channel->handle == handle) { 886 if (code & 1) { 887 // match odd commands (responses) by previous signaling identifier 888 if (channel->local_sig_id == sig_id) { 889 l2cap_signaling_handler_channel(channel, command); 890 break; 891 } 892 } else { 893 // match even commands (requests) by local channel id 894 if (channel->local_cid == dest_cid) { 895 l2cap_signaling_handler_channel(channel, command); 896 break; 897 } 898 } 899 } 900 } 901 } 902 903 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 904 905 // Get Channel ID 906 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 907 908 // Signaling Packet? 909 if (channel_id == 1) { 910 911 // Get Connection 912 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 913 914 uint16_t command_offset = 8; 915 while (command_offset < size) { 916 917 // handle signaling commands 918 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 919 920 // increment command_offset 921 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 922 } 923 924 l2cap_run(); 925 926 return; 927 } 928 929 // Find channel for this channel_id and connection handle 930 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 931 if (channel) { 932 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 933 } 934 } 935 936 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 937 switch (packet_type) { 938 case HCI_EVENT_PACKET: 939 l2cap_event_handler(packet, size); 940 break; 941 case HCI_ACL_DATA_PACKET: 942 l2cap_acl_handler(packet, size); 943 break; 944 default: 945 break; 946 } 947 } 948 949 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 950 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 951 channel->state = L2CAP_STATE_CLOSED; 952 l2cap_emit_channel_closed(channel); 953 // discard channel 954 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 955 btstack_memory_l2cap_channel_free(channel); 956 } 957 958 l2cap_service_t * l2cap_get_service(uint16_t psm){ 959 linked_item_t *it; 960 961 // close open channels 962 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 963 l2cap_service_t * service = ((l2cap_service_t *) it); 964 if ( service->psm == psm){ 965 return service; 966 }; 967 } 968 return NULL; 969 } 970 971 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 972 // check for alread registered psm 973 // TODO: emit error event 974 l2cap_service_t *service = l2cap_get_service(psm); 975 if (service) { 976 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 977 l2cap_emit_service_registered(connection, L2CAP_CHANNEL_ALREADY_REGISTERED, psm); 978 return; 979 } 980 981 // alloc structure 982 // TODO: emit error event 983 service = btstack_memory_l2cap_service_get(); 984 if (!service) { 985 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 986 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 987 return; 988 } 989 990 // fill in 991 service->psm = psm; 992 service->mtu = mtu; 993 service->connection = connection; 994 service->packet_handler = packet_handler; 995 996 // add to services list 997 linked_list_add(&l2cap_services, (linked_item_t *) service); 998 999 // enable page scan 1000 hci_connectable_control(1); 1001 1002 // done 1003 l2cap_emit_service_registered(connection, 0, psm); 1004 } 1005 1006 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1007 l2cap_service_t *service = l2cap_get_service(psm); 1008 if (!service) return; 1009 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1010 btstack_memory_l2cap_service_free(service); 1011 1012 // disable page scan when no services registered 1013 if (!linked_list_empty(&l2cap_services)) return; 1014 hci_connectable_control(0); 1015 } 1016 1017 // 1018 void l2cap_close_connection(void *connection){ 1019 linked_item_t *it; 1020 1021 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 1022 l2cap_channel_t * channel; 1023 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1024 channel = (l2cap_channel_t *) it; 1025 if (channel->connection == connection) { 1026 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1027 } 1028 } 1029 1030 // unregister services 1031 it = (linked_item_t *) &l2cap_services; 1032 while (it->next) { 1033 l2cap_service_t * service = (l2cap_service_t *) it->next; 1034 if (service->connection == connection){ 1035 it->next = it->next->next; 1036 btstack_memory_l2cap_service_free(service); 1037 } else { 1038 it = it->next; 1039 } 1040 } 1041 1042 // process 1043 l2cap_run(); 1044 } 1045