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