1 /* 2 * Copyright (C) 2009 by Matthias Ringwald 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the copyright holders nor the names of 14 * contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY MATTHIAS RINGWALD AND CONTRIBUTORS 18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 20 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 21 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 23 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 24 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 25 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 26 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 27 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 */ 31 32 /* 33 * l2cap.c 34 * 35 * Logical Link Control and Adaption Protocl (L2CAP) 36 * 37 * Created by Matthias Ringwald on 5/16/09. 38 */ 39 40 #include "l2cap.h" 41 #include "hci.h" 42 #include "hci_dump.h" 43 #include "debug.h" 44 #include "btstack_memory.h" 45 46 #include <stdarg.h> 47 #include <string.h> 48 49 #include <stdio.h> 50 51 // size of HCI ACL + L2CAP Header for regular data packets 52 #define COMPLETE_L2CAP_HEADER 8 53 54 // minimum signaling MTU 55 #define L2CAP_MINIMAL_MTU 48 56 #define L2CAP_DEFAULT_MTU 672 57 58 // nr of buffered acl packets in outgoing queue to get max performance 59 #define NR_BUFFERED_ACL_PACKETS 3 60 61 // used to cache l2cap rejects, echo, and informational requests 62 #define NR_PENDING_SIGNALING_RESPONSES 10 63 64 // offsets for L2CAP SIGNALING COMMANDS 65 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 66 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 67 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 68 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 69 70 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); 71 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size); 72 73 // used to cache l2cap rejects, echo, and informational requests 74 static l2cap_signaling_response_t signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; 75 static int signaling_responses_pending; 76 77 // static buffers 78 static uint8_t sig_buffer[L2CAP_MINIMAL_MTU]; 79 static uint8_t acl_buffer[HCI_ACL_3DH5_SIZE]; 80 81 static linked_list_t l2cap_channels = NULL; 82 static linked_list_t l2cap_services = NULL; 83 static void (*packet_handler) (void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) = null_packet_handler; 84 static int new_credits_blocked = 0; 85 86 // prototypes 87 static void l2cap_finialize_channel_close(l2cap_channel_t *channel); 88 static l2cap_service_t * l2cap_get_service(uint16_t psm); 89 static void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status); 90 static void l2cap_emit_channel_closed(l2cap_channel_t *channel); 91 static void l2cap_emit_connection_request(l2cap_channel_t *channel); 92 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); 93 94 95 void l2cap_init(){ 96 97 new_credits_blocked = 0; 98 signaling_responses_pending = 0; 99 100 // 101 // register callback with HCI 102 // 103 hci_register_packet_handler(&l2cap_packet_handler); 104 } 105 106 107 /** Register L2CAP packet handlers */ 108 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 109 } 110 void l2cap_register_packet_handler(void (*handler)(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 111 packet_handler = handler; 112 } 113 114 // notify client/protocol handler 115 void l2cap_dispatch(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 116 if (channel->packet_handler) { 117 (* (channel->packet_handler))(type, channel->local_cid, data, size); 118 } else { 119 (*packet_handler)(channel->connection, type, channel->local_cid, data, size); 120 } 121 } 122 123 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 124 uint8_t event[21]; 125 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 126 event[1] = sizeof(event) - 2; 127 event[2] = status; 128 bt_flip_addr(&event[3], channel->address); 129 bt_store_16(event, 9, channel->handle); 130 bt_store_16(event, 11, channel->psm); 131 bt_store_16(event, 13, channel->local_cid); 132 bt_store_16(event, 15, channel->remote_cid); 133 bt_store_16(event, 17, channel->local_mtu); 134 bt_store_16(event, 19, channel->remote_mtu); 135 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 136 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 137 } 138 139 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 140 uint8_t event[4]; 141 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 142 event[1] = sizeof(event) - 2; 143 bt_store_16(event, 2, channel->local_cid); 144 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 145 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 146 } 147 148 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 149 uint8_t event[16]; 150 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 151 event[1] = sizeof(event) - 2; 152 bt_flip_addr(&event[2], channel->address); 153 bt_store_16(event, 8, channel->handle); 154 bt_store_16(event, 10, channel->psm); 155 bt_store_16(event, 12, channel->local_cid); 156 bt_store_16(event, 14, channel->remote_cid); 157 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 158 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 159 } 160 161 void l2cap_emit_credits(l2cap_channel_t *channel, uint8_t credits) { 162 // track credits 163 channel->packets_granted += credits; 164 // log_info("l2cap_emit_credits for cid %u, credits given: %u (+%u)\n", channel->local_cid, channel->packets_granted, credits); 165 166 uint8_t event[5]; 167 event[0] = L2CAP_EVENT_CREDITS; 168 event[1] = sizeof(event) - 2; 169 bt_store_16(event, 2, channel->local_cid); 170 event[4] = credits; 171 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 172 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 173 } 174 175 void l2cap_block_new_credits(uint8_t blocked){ 176 new_credits_blocked = blocked; 177 } 178 179 void l2cap_hand_out_credits(void){ 180 181 if (new_credits_blocked) return; // we're told not to. used by daemon 182 183 linked_item_t *it; 184 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 185 if (!hci_number_free_acl_slots()) return; 186 l2cap_channel_t * channel = (l2cap_channel_t *) it; 187 if (channel->state != L2CAP_STATE_OPEN) continue; 188 if (hci_number_outgoing_packets(channel->handle) < NR_BUFFERED_ACL_PACKETS && channel->packets_granted == 0) { 189 l2cap_emit_credits(channel, 1); 190 } 191 } 192 } 193 194 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 195 linked_item_t *it; 196 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 197 l2cap_channel_t * channel = (l2cap_channel_t *) it; 198 if ( channel->local_cid == local_cid) { 199 return channel; 200 } 201 } 202 return NULL; 203 } 204 205 int l2cap_can_send_packet_now(uint16_t local_cid){ 206 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 207 if (!channel) return 0; 208 if (!channel->packets_granted) return 0; 209 return hci_can_send_packet_now(HCI_ACL_DATA_PACKET); 210 } 211 212 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 213 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 214 if (channel) { 215 return channel->remote_mtu; 216 } 217 return 0; 218 } 219 220 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 221 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 222 va_list argptr; 223 va_start(argptr, identifier); 224 uint16_t len = l2cap_create_signaling_internal(sig_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(sig_buffer, len); 228 } 229 230 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 231 232 // check for free places on BT module 233 if (!hci_number_free_acl_slots()) { 234 log_info("l2cap_send_internal cid %u, BT module full <-----\n", local_cid); 235 return BTSTACK_ACL_BUFFERS_FULL; 236 } 237 int err = 0; 238 239 // find channel for local_cid, construct l2cap packet and send 240 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 241 if (channel) { 242 if (channel->packets_granted > 0){ 243 --channel->packets_granted; 244 // log_info("l2cap_send_internal cid %u, handle %u, 1 credit used, credits left %u;\n", 245 // local_cid, channel->handle, channel->packets_granted); 246 } else { 247 log_error("l2cap_send_internal cid %u, no credits!\n", local_cid); 248 } 249 250 // 0 - Connection handle : PB=10 : BC=00 251 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 252 // 2 - ACL length 253 bt_store_16(acl_buffer, 2, len + 4); 254 // 4 - L2CAP packet length 255 bt_store_16(acl_buffer, 4, len + 0); 256 // 6 - L2CAP channel DEST 257 bt_store_16(acl_buffer, 6, channel->remote_cid); 258 // 8 - data 259 memcpy(&acl_buffer[8], data, len); 260 261 // send 262 err = hci_send_acl_packet(acl_buffer, len+8); 263 } 264 265 l2cap_hand_out_credits(); 266 267 return err; 268 } 269 270 // MARK: L2CAP_RUN 271 // process outstanding signaling tasks 272 void l2cap_run(void){ 273 274 // check pending signaling responses 275 while (signaling_responses_pending){ 276 277 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)) break; 278 279 hci_con_handle_t handle = signaling_responses[0].handle; 280 uint8_t sig_id = signaling_responses[0].sig_id; 281 uint8_t infoType = signaling_responses[0].infoType; 282 283 switch (signaling_responses[0].code){ 284 case ECHO_REQUEST: 285 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 286 break; 287 case INFORMATION_REQUEST: 288 if (infoType == 2) { 289 uint32_t features = 0; 290 // extended features request supported, however no features present 291 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, 4, &features); 292 } else { 293 // all other types are not supported 294 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 295 } 296 break; 297 default: 298 // should not happen 299 break; 300 } 301 302 // remove first item 303 signaling_responses_pending--; 304 int i; 305 for (i=0; i < signaling_responses_pending; i++){ 306 signaling_responses[i] = signaling_responses[i+1]; 307 } 308 } 309 310 uint8_t config_options[4]; 311 linked_item_t *it; 312 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 313 314 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 315 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)) break; 316 317 l2cap_channel_t * channel = (l2cap_channel_t *) it; 318 319 // log_info("l2cap_run: state %u, var 0x%02x\n", channel->state, channel->state_var); 320 321 switch (channel->state){ 322 323 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 324 // send connection request - set state first 325 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 326 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 327 hci_send_cmd(&hci_create_connection, channel->address, 0xcc18, 0, 0, 0, 1); 328 break; 329 330 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 331 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, channel->reason, 0); 332 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 333 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 334 btstack_memory_l2cap_channel_free(channel); 335 break; 336 337 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 338 channel->state = L2CAP_STATE_CONFIG; 339 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ; 340 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 341 break; 342 343 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 344 // success, start l2cap handshake 345 channel->local_sig_id = l2cap_next_sig_id(); 346 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 347 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 348 break; 349 350 case L2CAP_STATE_CONFIG: 351 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 352 channel->state_var &= ~L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP; 353 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP; 354 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, 0, 0, 0, NULL); 355 } 356 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 357 channel->state_var &= ~L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ; 358 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ; 359 channel->local_sig_id = l2cap_next_sig_id(); 360 config_options[0] = 1; // MTU 361 config_options[1] = 2; // len param 362 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 363 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 364 } 365 if (l2cap_channel_ready_for_open(channel)){ 366 channel->state = L2CAP_STATE_OPEN; 367 l2cap_emit_channel_opened(channel, 0); // success 368 l2cap_emit_credits(channel, 1); 369 } 370 break; 371 372 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 373 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 374 l2cap_finialize_channel_close(channel); 375 break; 376 377 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 378 channel->local_sig_id = l2cap_next_sig_id(); 379 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 380 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 381 break; 382 default: 383 break; 384 } 385 } 386 } 387 388 static uint16_t l2cap_max_l2cap_mtu(void){ 389 return hci_max_acl_data_packet_length()-4; // 4 bytes for L2CAP header 390 } 391 392 // open outgoing L2CAP channel 393 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 394 bd_addr_t address, uint16_t psm, uint16_t mtu){ 395 396 // alloc structure 397 l2cap_channel_t * chan = btstack_memory_l2cap_channel_get(); 398 // TODO: emit error event 399 if (!chan) return; 400 401 // limit local mtu to max acl packet length 402 if (mtu > l2cap_max_l2cap_mtu()) { 403 mtu = l2cap_max_l2cap_mtu(); 404 } 405 406 // fill in 407 BD_ADDR_COPY(chan->address, address); 408 chan->psm = psm; 409 chan->handle = 0; 410 chan->connection = connection; 411 chan->packet_handler = packet_handler; 412 chan->remote_mtu = L2CAP_MINIMAL_MTU; 413 chan->local_mtu = mtu; 414 chan->packets_granted = 0; 415 416 // set initial state 417 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 418 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 419 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 420 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 421 422 // add to connections list 423 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 424 425 l2cap_run(); 426 } 427 428 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 429 // find channel for local_cid 430 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 431 if (channel) { 432 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 433 } 434 // process 435 l2cap_run(); 436 } 437 438 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 439 linked_item_t *it = (linked_item_t *) &l2cap_channels; 440 while (it->next){ 441 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 442 if ( ! BD_ADDR_CMP( channel->address, address) ){ 443 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 444 // failure, forward error code 445 l2cap_emit_channel_opened(channel, status); 446 // discard channel 447 it->next = it->next->next; 448 btstack_memory_l2cap_channel_free(channel); 449 } 450 } else { 451 it = it->next; 452 } 453 } 454 } 455 456 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 457 linked_item_t *it; 458 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 459 l2cap_channel_t * channel = (l2cap_channel_t *) it; 460 if ( ! BD_ADDR_CMP( channel->address, address) ){ 461 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 462 // success, start l2cap handshake 463 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 464 channel->handle = handle; 465 channel->local_cid = l2cap_next_local_cid(); 466 } 467 } 468 } 469 // process 470 l2cap_run(); 471 } 472 473 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 474 475 bd_addr_t address; 476 hci_con_handle_t handle; 477 l2cap_channel_t * channel; 478 linked_item_t *it; 479 int hci_con_used; 480 481 switch(packet[0]){ 482 483 // handle connection complete events 484 case HCI_EVENT_CONNECTION_COMPLETE: 485 bt_flip_addr(address, &packet[5]); 486 if (packet[2] == 0){ 487 handle = READ_BT_16(packet, 3); 488 l2cap_handle_connection_success_for_addr(address, handle); 489 } else { 490 l2cap_handle_connection_failed_for_addr(address, packet[2]); 491 } 492 break; 493 494 // handle successful create connection cancel command 495 case HCI_EVENT_COMMAND_COMPLETE: 496 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 497 if (packet[5] == 0){ 498 bt_flip_addr(address, &packet[6]); 499 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 500 l2cap_handle_connection_failed_for_addr(address, 0x16); 501 } 502 } 503 l2cap_run(); // try sending signaling packets first 504 break; 505 506 case HCI_EVENT_COMMAND_STATUS: 507 l2cap_run(); // try sending signaling packets first 508 break; 509 510 // handle disconnection complete events 511 case HCI_EVENT_DISCONNECTION_COMPLETE: 512 // send l2cap disconnect events for all channels on this handle 513 handle = READ_BT_16(packet, 3); 514 it = (linked_item_t *) &l2cap_channels; 515 while (it->next){ 516 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 517 if ( channel->handle == handle ){ 518 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 519 it->next = it->next->next; 520 l2cap_emit_channel_closed(channel); 521 btstack_memory_l2cap_channel_free(channel); 522 } else { 523 it = it->next; 524 } 525 } 526 break; 527 528 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 529 l2cap_run(); // try sending signaling packets first 530 l2cap_hand_out_credits(); 531 break; 532 533 // HCI Connection Timeouts 534 case L2CAP_EVENT_TIMEOUT_CHECK: 535 handle = READ_BT_16(packet, 2); 536 if (hci_authentication_active_for_handle(handle)) break; 537 hci_con_used = 0; 538 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 539 channel = (l2cap_channel_t *) it; 540 if (channel->handle == handle) { 541 hci_con_used = 1; 542 } 543 } 544 if (hci_con_used) break; 545 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 546 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 547 break; 548 549 case DAEMON_EVENT_HCI_PACKET_SENT: 550 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 551 channel = (l2cap_channel_t *) it; 552 if (channel->packet_handler) { 553 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 554 } 555 } 556 break; 557 558 default: 559 break; 560 } 561 562 // pass on 563 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 564 } 565 566 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 567 channel->remote_sig_id = identifier; 568 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 569 l2cap_run(); 570 } 571 572 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 573 574 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid %u\n", handle, psm, source_cid); 575 l2cap_service_t *service = l2cap_get_service(psm); 576 if (!service) { 577 // 0x0002 PSM not supported 578 // log_info("l2cap_handle_connection_request no PSM for psm %u/n", psm); 579 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, 0x0002, 0); 580 return; 581 } 582 583 hci_connection_t * hci_connection = connection_for_handle( handle ); 584 if (!hci_connection) { 585 log_error("no hci_connection for handle %u\n", handle); 586 // TODO: emit error 587 return; 588 } 589 // alloc structure 590 // log_info("l2cap_handle_connection_request register channel\n"); 591 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 592 // TODO: emit error event 593 if (!channel) return; 594 595 // fill in 596 BD_ADDR_COPY(channel->address, hci_connection->address); 597 channel->psm = psm; 598 channel->handle = handle; 599 channel->connection = service->connection; 600 channel->packet_handler = service->packet_handler; 601 channel->local_cid = l2cap_next_local_cid(); 602 channel->remote_cid = source_cid; 603 channel->local_mtu = service->mtu; 604 channel->remote_mtu = L2CAP_DEFAULT_MTU; 605 channel->packets_granted = 0; 606 channel->remote_sig_id = sig_id; 607 608 // limit local mtu to max acl packet length 609 if (channel->local_mtu > l2cap_max_l2cap_mtu()) { 610 channel->local_mtu = l2cap_max_l2cap_mtu(); 611 } 612 613 // set initial state 614 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 615 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 616 617 // add to connections list 618 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 619 620 // emit incoming connection request 621 l2cap_emit_connection_request(channel); 622 } 623 624 void l2cap_accept_connection_internal(uint16_t local_cid){ 625 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 626 if (!channel) { 627 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 628 return; 629 } 630 631 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 632 633 // process 634 l2cap_run(); 635 } 636 637 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 638 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 639 if (!channel) { 640 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 641 return; 642 } 643 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 644 channel->reason = reason; 645 l2cap_run(); 646 } 647 648 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 649 650 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 651 652 // accept the other's configuration options 653 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 654 uint16_t pos = 8; 655 while (pos < end_pos){ 656 uint8_t type = command[pos++]; 657 uint8_t length = command[pos++]; 658 // MTU { type(8): 1, len(8):2, MTU(16) } 659 if ((type & 0x7f) == 1 && length == 2){ 660 channel->remote_mtu = READ_BT_16(command, pos); 661 // log_info("l2cap cid %u, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 662 } 663 pos += length; 664 } 665 } 666 667 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 668 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 669 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 670 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 671 return 1; 672 } 673 674 675 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 676 677 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 678 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 679 uint16_t result = 0; 680 681 log_info("signaling handler code %u, state %u\n", code, channel->state); 682 683 // handle DISCONNECT REQUESTS seperately 684 if (code == DISCONNECTION_REQUEST){ 685 switch (channel->state){ 686 case L2CAP_STATE_CONFIG: 687 case L2CAP_STATE_OPEN: 688 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 689 case L2CAP_STATE_WAIT_DISCONNECT: 690 l2cap_handle_disconnect_request(channel, identifier); 691 break; 692 693 default: 694 // ignore in other states 695 break; 696 } 697 return; 698 } 699 700 switch (channel->state) { 701 702 case L2CAP_STATE_WAIT_CONNECT_RSP: 703 switch (code){ 704 case CONNECTION_RESPONSE: 705 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 706 switch (result) { 707 case 0: 708 // successful connection 709 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 710 channel->state = L2CAP_STATE_CONFIG; 711 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ; 712 break; 713 case 1: 714 // connection pending. get some coffee 715 break; 716 default: 717 // channel closed 718 channel->state = L2CAP_STATE_CLOSED; 719 720 // map l2cap connection response result to BTstack status enumeration 721 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 722 723 // drop link key if security block 724 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 725 hci_drop_link_key_for_bd_addr(&channel->address); 726 } 727 728 // discard channel 729 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 730 btstack_memory_l2cap_channel_free(channel); 731 break; 732 } 733 break; 734 735 default: 736 //@TODO: implement other signaling packets 737 break; 738 } 739 break; 740 741 case L2CAP_STATE_CONFIG: 742 switch (code) { 743 case CONFIGURE_REQUEST: 744 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ; 745 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP; 746 l2cap_signaling_handle_configure_request(channel, command); 747 break; 748 case CONFIGURE_RESPONSE: 749 channel->state_var |= L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP; 750 break; 751 default: 752 break; 753 } 754 if (l2cap_channel_ready_for_open(channel)){ 755 // for open: 756 channel->state = L2CAP_STATE_OPEN; 757 l2cap_emit_channel_opened(channel, 0); 758 l2cap_emit_credits(channel, 1); 759 } 760 break; 761 762 case L2CAP_STATE_WAIT_DISCONNECT: 763 switch (code) { 764 case DISCONNECTION_RESPONSE: 765 l2cap_finialize_channel_close(channel); 766 break; 767 default: 768 //@TODO: implement other signaling packets 769 break; 770 } 771 break; 772 773 case L2CAP_STATE_CLOSED: 774 // @TODO handle incoming requests 775 break; 776 777 case L2CAP_STATE_OPEN: 778 //@TODO: implement other signaling packets, e.g. re-configure 779 break; 780 default: 781 break; 782 } 783 // log_info("new state %u\n", channel->state); 784 } 785 786 787 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 788 789 // get code, signalind identifier and command len 790 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 791 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 792 793 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 794 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 795 return; 796 } 797 798 // general commands without an assigned channel 799 switch(code) { 800 801 case CONNECTION_REQUEST: { 802 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 803 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 804 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 805 return; 806 } 807 808 case ECHO_REQUEST: { 809 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 810 signaling_responses[signaling_responses_pending].handle = handle; 811 signaling_responses[signaling_responses_pending].code = code; 812 signaling_responses[signaling_responses_pending].sig_id = sig_id; 813 signaling_responses_pending++; 814 } 815 l2cap_run(); 816 return; 817 } 818 819 case INFORMATION_REQUEST: { 820 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 821 // we neither support connectionless L2CAP data nor support any flow control modes yet 822 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 823 signaling_responses[signaling_responses_pending].handle = handle; 824 signaling_responses[signaling_responses_pending].code = code; 825 signaling_responses[signaling_responses_pending].sig_id = sig_id; 826 signaling_responses[signaling_responses_pending].infoType = infoType; 827 signaling_responses_pending++; 828 } 829 l2cap_run(); 830 return; 831 } 832 833 default: 834 break; 835 } 836 837 838 // Get potential destination CID 839 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 840 841 // Find channel for this sig_id and connection handle 842 linked_item_t *it; 843 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 844 l2cap_channel_t * channel = (l2cap_channel_t *) it; 845 if (channel->handle == handle) { 846 if (code & 1) { 847 // match odd commands (responses) by previous signaling identifier 848 if (channel->local_sig_id == sig_id) { 849 l2cap_signaling_handler_channel(channel, command); 850 break; 851 } 852 } else { 853 // match even commands (requests) by local channel id 854 if (channel->local_cid == dest_cid) { 855 l2cap_signaling_handler_channel(channel, command); 856 break; 857 } 858 } 859 } 860 } 861 } 862 863 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 864 865 // Get Channel ID 866 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 867 868 // Signaling Packet? 869 if (channel_id == 1) { 870 871 // Get Connection 872 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 873 874 uint16_t command_offset = 8; 875 while (command_offset < size) { 876 877 // handle signaling commands 878 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 879 880 // increment command_offset 881 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 882 } 883 884 l2cap_run(); 885 886 return; 887 } 888 889 // Find channel for this channel_id and connection handle 890 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 891 if (channel) { 892 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 893 } 894 } 895 896 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 897 switch (packet_type) { 898 case HCI_EVENT_PACKET: 899 l2cap_event_handler(packet, size); 900 break; 901 case HCI_ACL_DATA_PACKET: 902 l2cap_acl_handler(packet, size); 903 break; 904 default: 905 break; 906 } 907 } 908 909 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 910 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 911 channel->state = L2CAP_STATE_CLOSED; 912 l2cap_emit_channel_closed(channel); 913 // discard channel 914 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 915 btstack_memory_l2cap_channel_free(channel); 916 } 917 918 l2cap_service_t * l2cap_get_service(uint16_t psm){ 919 linked_item_t *it; 920 921 // close open channels 922 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 923 l2cap_service_t * service = ((l2cap_service_t *) it); 924 if ( service->psm == psm){ 925 return service; 926 }; 927 } 928 return NULL; 929 } 930 931 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 932 // check for alread registered psm // TODO: emit error event 933 l2cap_service_t *service = l2cap_get_service(psm); 934 if (service) return; 935 936 // alloc structure // TODO: emit error event 937 service = btstack_memory_l2cap_service_get(); 938 if (!service) return; 939 940 // fill in 941 service->psm = psm; 942 service->mtu = mtu; 943 service->connection = connection; 944 service->packet_handler = packet_handler; 945 946 // add to services list 947 linked_list_add(&l2cap_services, (linked_item_t *) service); 948 } 949 950 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 951 l2cap_service_t *service = l2cap_get_service(psm); 952 if (!service) return; 953 linked_list_remove(&l2cap_services, (linked_item_t *) service); 954 btstack_memory_l2cap_service_free(service); 955 } 956 957 // 958 void l2cap_close_connection(void *connection){ 959 linked_item_t *it; 960 961 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 962 l2cap_channel_t * channel; 963 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 964 channel = (l2cap_channel_t *) it; 965 if (channel->connection == connection) { 966 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 967 } 968 } 969 970 // unregister services 971 it = (linked_item_t *) &l2cap_services; 972 while (it->next) { 973 l2cap_service_t * service = (l2cap_service_t *) it->next; 974 if (service->connection == connection){ 975 it->next = it->next->next; 976 btstack_memory_l2cap_service_free(service); 977 } else { 978 it = it->next; 979 } 980 } 981 982 // process 983 l2cap_run(); 984 } 985