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 linked_item_t *next; 348 for (it = (linked_item_t *) l2cap_channels; it ; it = next){ 349 next = it->next; // cache next item as current item might get freed 350 351 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 352 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)) break; 353 354 l2cap_channel_t * channel = (l2cap_channel_t *) it; 355 356 // log_info("l2cap_run: state %u, var 0x%02x\n", channel->state, channel->state_var); 357 358 359 switch (channel->state){ 360 361 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 362 // send connection request - set state first 363 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 364 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 365 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 366 break; 367 368 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 369 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, channel->reason, 0); 370 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 371 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); // -- remove from list 372 btstack_memory_l2cap_channel_free(channel); 373 break; 374 375 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 376 channel->state = L2CAP_STATE_CONFIG; 377 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ; 378 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 379 break; 380 381 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 382 // success, start l2cap handshake 383 channel->local_sig_id = l2cap_next_sig_id(); 384 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 385 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 386 break; 387 388 case L2CAP_STATE_CONFIG: 389 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 390 channel->state_var &= ~L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP; 391 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP; 392 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, 0, 0, 0, NULL); 393 } 394 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 395 channel->state_var &= ~L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ; 396 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ; 397 channel->local_sig_id = l2cap_next_sig_id(); 398 config_options[0] = 1; // MTU 399 config_options[1] = 2; // len param 400 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 401 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 402 } 403 if (l2cap_channel_ready_for_open(channel)){ 404 channel->state = L2CAP_STATE_OPEN; 405 l2cap_emit_channel_opened(channel, 0); // success 406 l2cap_emit_credits(channel, 1); 407 } 408 break; 409 410 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 411 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 412 l2cap_finialize_channel_close(channel); // -- remove from list 413 break; 414 415 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 416 channel->local_sig_id = l2cap_next_sig_id(); 417 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 418 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 419 break; 420 default: 421 break; 422 } 423 } 424 } 425 426 uint16_t l2cap_max_mtu(void){ 427 return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE; 428 } 429 430 // open outgoing L2CAP channel 431 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 432 bd_addr_t address, uint16_t psm, uint16_t mtu){ 433 434 // alloc structure 435 l2cap_channel_t * chan = btstack_memory_l2cap_channel_get(); 436 if (!chan) { 437 // emit error event 438 l2cap_channel_t dummy_channel; 439 BD_ADDR_COPY(dummy_channel.address, address); 440 dummy_channel.psm = psm; 441 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 442 return; 443 } 444 // limit local mtu to max acl packet length 445 if (mtu > l2cap_max_mtu()) { 446 mtu = l2cap_max_mtu(); 447 } 448 449 // fill in 450 BD_ADDR_COPY(chan->address, address); 451 chan->psm = psm; 452 chan->handle = 0; 453 chan->connection = connection; 454 chan->packet_handler = packet_handler; 455 chan->remote_mtu = L2CAP_MINIMAL_MTU; 456 chan->local_mtu = mtu; 457 chan->packets_granted = 0; 458 459 // set initial state 460 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 461 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 462 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 463 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 464 465 // add to connections list 466 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 467 468 l2cap_run(); 469 } 470 471 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 472 // find channel for local_cid 473 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 474 if (channel) { 475 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 476 } 477 // process 478 l2cap_run(); 479 } 480 481 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 482 linked_item_t *it = (linked_item_t *) &l2cap_channels; 483 while (it->next){ 484 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 485 if ( ! BD_ADDR_CMP( channel->address, address) ){ 486 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 487 // failure, forward error code 488 l2cap_emit_channel_opened(channel, status); 489 // discard channel 490 it->next = it->next->next; 491 btstack_memory_l2cap_channel_free(channel); 492 } 493 } else { 494 it = it->next; 495 } 496 } 497 } 498 499 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 500 linked_item_t *it; 501 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 502 l2cap_channel_t * channel = (l2cap_channel_t *) it; 503 if ( ! BD_ADDR_CMP( channel->address, address) ){ 504 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 505 // success, start l2cap handshake 506 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 507 channel->handle = handle; 508 channel->local_cid = l2cap_next_local_cid(); 509 } 510 } 511 } 512 // process 513 l2cap_run(); 514 } 515 516 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 517 518 bd_addr_t address; 519 hci_con_handle_t handle; 520 l2cap_channel_t * channel; 521 linked_item_t *it; 522 int hci_con_used; 523 524 switch(packet[0]){ 525 526 // handle connection complete events 527 case HCI_EVENT_CONNECTION_COMPLETE: 528 bt_flip_addr(address, &packet[5]); 529 if (packet[2] == 0){ 530 handle = READ_BT_16(packet, 3); 531 l2cap_handle_connection_success_for_addr(address, handle); 532 } else { 533 l2cap_handle_connection_failed_for_addr(address, packet[2]); 534 } 535 break; 536 537 // handle successful create connection cancel command 538 case HCI_EVENT_COMMAND_COMPLETE: 539 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 540 if (packet[5] == 0){ 541 bt_flip_addr(address, &packet[6]); 542 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 543 l2cap_handle_connection_failed_for_addr(address, 0x16); 544 } 545 } 546 l2cap_run(); // try sending signaling packets first 547 break; 548 549 case HCI_EVENT_COMMAND_STATUS: 550 l2cap_run(); // try sending signaling packets first 551 break; 552 553 // handle disconnection complete events 554 case HCI_EVENT_DISCONNECTION_COMPLETE: 555 // send l2cap disconnect events for all channels on this handle 556 handle = READ_BT_16(packet, 3); 557 it = (linked_item_t *) &l2cap_channels; 558 while (it->next){ 559 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 560 if ( channel->handle == handle ){ 561 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 562 it->next = it->next->next; 563 l2cap_emit_channel_closed(channel); 564 btstack_memory_l2cap_channel_free(channel); 565 } else { 566 it = it->next; 567 } 568 } 569 break; 570 571 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 572 l2cap_run(); // try sending signaling packets first 573 l2cap_hand_out_credits(); 574 break; 575 576 // HCI Connection Timeouts 577 case L2CAP_EVENT_TIMEOUT_CHECK: 578 handle = READ_BT_16(packet, 2); 579 if (hci_authentication_active_for_handle(handle)) break; 580 hci_con_used = 0; 581 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 582 channel = (l2cap_channel_t *) it; 583 if (channel->handle == handle) { 584 hci_con_used = 1; 585 } 586 } 587 if (hci_con_used) break; 588 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 589 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 590 break; 591 592 case DAEMON_EVENT_HCI_PACKET_SENT: 593 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 594 channel = (l2cap_channel_t *) it; 595 if (channel->packet_handler) { 596 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 597 } 598 } 599 break; 600 601 default: 602 break; 603 } 604 605 // pass on 606 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 607 } 608 609 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 610 channel->remote_sig_id = identifier; 611 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 612 l2cap_run(); 613 } 614 615 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 616 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 617 signaling_responses[signaling_responses_pending].handle = handle; 618 signaling_responses[signaling_responses_pending].code = code; 619 signaling_responses[signaling_responses_pending].sig_id = sig_id; 620 signaling_responses[signaling_responses_pending].data = data; 621 signaling_responses_pending++; 622 l2cap_run(); 623 } 624 } 625 626 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 627 628 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid %u\n", handle, psm, source_cid); 629 l2cap_service_t *service = l2cap_get_service(psm); 630 if (!service) { 631 // 0x0002 PSM not supported 632 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 633 return; 634 } 635 636 hci_connection_t * hci_connection = connection_for_handle( handle ); 637 if (!hci_connection) { 638 // 639 log_error("no hci_connection for handle %u\n", handle); 640 return; 641 } 642 // alloc structure 643 // log_info("l2cap_handle_connection_request register channel\n"); 644 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 645 if (!channel){ 646 // 0x0004 No resources available 647 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 648 return; 649 } 650 651 // fill in 652 BD_ADDR_COPY(channel->address, hci_connection->address); 653 channel->psm = psm; 654 channel->handle = handle; 655 channel->connection = service->connection; 656 channel->packet_handler = service->packet_handler; 657 channel->local_cid = l2cap_next_local_cid(); 658 channel->remote_cid = source_cid; 659 channel->local_mtu = service->mtu; 660 channel->remote_mtu = L2CAP_DEFAULT_MTU; 661 channel->packets_granted = 0; 662 channel->remote_sig_id = sig_id; 663 664 // limit local mtu to max acl packet length 665 if (channel->local_mtu > l2cap_max_mtu()) { 666 channel->local_mtu = l2cap_max_mtu(); 667 } 668 669 // set initial state 670 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 671 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 672 673 // add to connections list 674 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 675 676 // emit incoming connection request 677 l2cap_emit_connection_request(channel); 678 } 679 680 void l2cap_accept_connection_internal(uint16_t local_cid){ 681 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 682 if (!channel) { 683 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 684 return; 685 } 686 687 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 688 689 // process 690 l2cap_run(); 691 } 692 693 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 694 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 695 if (!channel) { 696 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 697 return; 698 } 699 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 700 channel->reason = reason; 701 l2cap_run(); 702 } 703 704 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 705 706 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 707 708 // accept the other's configuration options 709 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 710 uint16_t pos = 8; 711 while (pos < end_pos){ 712 uint8_t type = command[pos++]; 713 uint8_t length = command[pos++]; 714 // MTU { type(8): 1, len(8):2, MTU(16) } 715 if ((type & 0x7f) == 1 && length == 2){ 716 channel->remote_mtu = READ_BT_16(command, pos); 717 // log_info("l2cap cid %u, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 718 } 719 pos += length; 720 } 721 } 722 723 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 724 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 725 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 726 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 727 return 1; 728 } 729 730 731 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 732 733 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 734 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 735 uint16_t result = 0; 736 737 log_info("L2CAP signaling handler code %u, state %u\n", code, channel->state); 738 739 // handle DISCONNECT REQUESTS seperately 740 if (code == DISCONNECTION_REQUEST){ 741 switch (channel->state){ 742 case L2CAP_STATE_CONFIG: 743 case L2CAP_STATE_OPEN: 744 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 745 case L2CAP_STATE_WAIT_DISCONNECT: 746 l2cap_handle_disconnect_request(channel, identifier); 747 break; 748 749 default: 750 // ignore in other states 751 break; 752 } 753 return; 754 } 755 756 // @STATEMACHINE(l2cap) 757 switch (channel->state) { 758 759 case L2CAP_STATE_WAIT_CONNECT_RSP: 760 switch (code){ 761 case CONNECTION_RESPONSE: 762 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 763 switch (result) { 764 case 0: 765 // successful connection 766 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 767 channel->state = L2CAP_STATE_CONFIG; 768 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ; 769 break; 770 case 1: 771 // connection pending. get some coffee 772 break; 773 default: 774 // channel closed 775 channel->state = L2CAP_STATE_CLOSED; 776 777 // map l2cap connection response result to BTstack status enumeration 778 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 779 780 // drop link key if security block 781 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 782 hci_drop_link_key_for_bd_addr(&channel->address); 783 } 784 785 // discard channel 786 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 787 btstack_memory_l2cap_channel_free(channel); 788 break; 789 } 790 break; 791 792 default: 793 //@TODO: implement other signaling packets 794 break; 795 } 796 break; 797 798 case L2CAP_STATE_CONFIG: 799 switch (code) { 800 case CONFIGURE_REQUEST: 801 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ; 802 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP; 803 l2cap_signaling_handle_configure_request(channel, command); 804 break; 805 case CONFIGURE_RESPONSE: 806 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP; 807 break; 808 default: 809 break; 810 } 811 if (l2cap_channel_ready_for_open(channel)){ 812 // for open: 813 channel->state = L2CAP_STATE_OPEN; 814 l2cap_emit_channel_opened(channel, 0); 815 l2cap_emit_credits(channel, 1); 816 } 817 break; 818 819 case L2CAP_STATE_WAIT_DISCONNECT: 820 switch (code) { 821 case DISCONNECTION_RESPONSE: 822 l2cap_finialize_channel_close(channel); 823 break; 824 default: 825 //@TODO: implement other signaling packets 826 break; 827 } 828 break; 829 830 case L2CAP_STATE_CLOSED: 831 // @TODO handle incoming requests 832 break; 833 834 case L2CAP_STATE_OPEN: 835 //@TODO: implement other signaling packets, e.g. re-configure 836 break; 837 default: 838 break; 839 } 840 // log_info("new state %u\n", channel->state); 841 } 842 843 844 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 845 846 // get code, signalind identifier and command len 847 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 848 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 849 850 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 851 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 852 return; 853 } 854 855 // general commands without an assigned channel 856 switch(code) { 857 858 case CONNECTION_REQUEST: { 859 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 860 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 861 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 862 return; 863 } 864 865 case ECHO_REQUEST: 866 l2cap_register_signaling_response(handle, code, sig_id, 0); 867 return; 868 869 case INFORMATION_REQUEST: { 870 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 871 l2cap_register_signaling_response(handle, code, sig_id, infoType); 872 return; 873 } 874 875 default: 876 break; 877 } 878 879 880 // Get potential destination CID 881 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 882 883 // Find channel for this sig_id and connection handle 884 linked_item_t *it; 885 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 886 l2cap_channel_t * channel = (l2cap_channel_t *) it; 887 if (channel->handle == handle) { 888 if (code & 1) { 889 // match odd commands (responses) by previous signaling identifier 890 if (channel->local_sig_id == sig_id) { 891 l2cap_signaling_handler_channel(channel, command); 892 break; 893 } 894 } else { 895 // match even commands (requests) by local channel id 896 if (channel->local_cid == dest_cid) { 897 l2cap_signaling_handler_channel(channel, command); 898 break; 899 } 900 } 901 } 902 } 903 } 904 905 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 906 907 // Get Channel ID 908 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 909 910 // Signaling Packet? 911 if (channel_id == 1) { 912 913 // Get Connection 914 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 915 916 uint16_t command_offset = 8; 917 while (command_offset < size) { 918 919 // handle signaling commands 920 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 921 922 // increment command_offset 923 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 924 } 925 926 l2cap_run(); 927 928 return; 929 } 930 931 // Find channel for this channel_id and connection handle 932 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 933 if (channel) { 934 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 935 } 936 } 937 938 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 939 switch (packet_type) { 940 case HCI_EVENT_PACKET: 941 l2cap_event_handler(packet, size); 942 break; 943 case HCI_ACL_DATA_PACKET: 944 l2cap_acl_handler(packet, size); 945 break; 946 default: 947 break; 948 } 949 } 950 951 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 952 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 953 channel->state = L2CAP_STATE_CLOSED; 954 l2cap_emit_channel_closed(channel); 955 // discard channel 956 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 957 btstack_memory_l2cap_channel_free(channel); 958 } 959 960 l2cap_service_t * l2cap_get_service(uint16_t psm){ 961 linked_item_t *it; 962 963 // close open channels 964 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 965 l2cap_service_t * service = ((l2cap_service_t *) it); 966 if ( service->psm == psm){ 967 return service; 968 }; 969 } 970 return NULL; 971 } 972 973 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 974 // check for alread registered psm 975 // TODO: emit error event 976 l2cap_service_t *service = l2cap_get_service(psm); 977 if (service) { 978 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 979 l2cap_emit_service_registered(connection, L2CAP_CHANNEL_ALREADY_REGISTERED, psm); 980 return; 981 } 982 983 // alloc structure 984 // TODO: emit error event 985 service = btstack_memory_l2cap_service_get(); 986 if (!service) { 987 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 988 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 989 return; 990 } 991 992 // fill in 993 service->psm = psm; 994 service->mtu = mtu; 995 service->connection = connection; 996 service->packet_handler = packet_handler; 997 998 // add to services list 999 linked_list_add(&l2cap_services, (linked_item_t *) service); 1000 1001 // enable page scan 1002 hci_connectable_control(1); 1003 1004 // done 1005 l2cap_emit_service_registered(connection, 0, psm); 1006 } 1007 1008 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1009 l2cap_service_t *service = l2cap_get_service(psm); 1010 if (!service) return; 1011 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1012 btstack_memory_l2cap_service_free(service); 1013 1014 // disable page scan when no services registered 1015 if (!linked_list_empty(&l2cap_services)) return; 1016 hci_connectable_control(0); 1017 } 1018 1019 // 1020 void l2cap_close_connection(void *connection){ 1021 linked_item_t *it; 1022 1023 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 1024 l2cap_channel_t * channel; 1025 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1026 channel = (l2cap_channel_t *) it; 1027 if (channel->connection == connection) { 1028 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1029 } 1030 } 1031 1032 // unregister services 1033 it = (linked_item_t *) &l2cap_services; 1034 while (it->next) { 1035 l2cap_service_t * service = (l2cap_service_t *) it->next; 1036 if (service->connection == connection){ 1037 it->next = it->next->next; 1038 btstack_memory_l2cap_service_free(service); 1039 } else { 1040 it = it->next; 1041 } 1042 } 1043 1044 // process 1045 l2cap_run(); 1046 } 1047