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 static btstack_packet_handler_t attribute_protocol_packet_handler = NULL; 76 static btstack_packet_handler_t security_protocol_packet_handler = NULL; 77 78 // prototypes 79 static void l2cap_finialize_channel_close(l2cap_channel_t *channel); 80 static l2cap_service_t * l2cap_get_service(uint16_t psm); 81 static void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status); 82 static void l2cap_emit_channel_closed(l2cap_channel_t *channel); 83 static void l2cap_emit_connection_request(l2cap_channel_t *channel); 84 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); 85 86 87 void l2cap_init(){ 88 new_credits_blocked = 0; 89 signaling_responses_pending = 0; 90 91 l2cap_channels = NULL; 92 l2cap_services = NULL; 93 94 packet_handler = null_packet_handler; 95 96 // 97 // register callback with HCI 98 // 99 hci_register_packet_handler(&l2cap_packet_handler); 100 hci_connectable_control(0); // no services yet 101 } 102 103 104 /** Register L2CAP packet handlers */ 105 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 106 } 107 void l2cap_register_packet_handler(void (*handler)(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 108 packet_handler = handler; 109 } 110 111 // notify client/protocol handler 112 void l2cap_dispatch(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 113 if (channel->packet_handler) { 114 (* (channel->packet_handler))(type, channel->local_cid, data, size); 115 } else { 116 (*packet_handler)(channel->connection, type, channel->local_cid, data, size); 117 } 118 } 119 120 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 121 uint8_t event[21]; 122 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 123 event[1] = sizeof(event) - 2; 124 event[2] = status; 125 bt_flip_addr(&event[3], channel->address); 126 bt_store_16(event, 9, channel->handle); 127 bt_store_16(event, 11, channel->psm); 128 bt_store_16(event, 13, channel->local_cid); 129 bt_store_16(event, 15, channel->remote_cid); 130 bt_store_16(event, 17, channel->local_mtu); 131 bt_store_16(event, 19, channel->remote_mtu); 132 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 133 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 134 } 135 136 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 137 uint8_t event[4]; 138 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 139 event[1] = sizeof(event) - 2; 140 bt_store_16(event, 2, channel->local_cid); 141 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 142 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 143 } 144 145 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 146 uint8_t event[16]; 147 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 148 event[1] = sizeof(event) - 2; 149 bt_flip_addr(&event[2], channel->address); 150 bt_store_16(event, 8, channel->handle); 151 bt_store_16(event, 10, channel->psm); 152 bt_store_16(event, 12, channel->local_cid); 153 bt_store_16(event, 14, channel->remote_cid); 154 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 155 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 156 } 157 158 static void l2cap_emit_service_registered(void *connection, uint8_t status, uint16_t psm){ 159 uint8_t event[5]; 160 event[0] = L2CAP_EVENT_SERVICE_REGISTERED; 161 event[1] = sizeof(event) - 2; 162 event[2] = status; 163 bt_store_16(event, 3, psm); 164 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 165 (*packet_handler)(connection, HCI_EVENT_PACKET, 0, event, sizeof(event)); 166 } 167 168 void l2cap_emit_credits(l2cap_channel_t *channel, uint8_t credits) { 169 // track credits 170 channel->packets_granted += credits; 171 // log_info("l2cap_emit_credits for cid %u, credits given: %u (+%u)\n", channel->local_cid, channel->packets_granted, credits); 172 173 uint8_t event[5]; 174 event[0] = L2CAP_EVENT_CREDITS; 175 event[1] = sizeof(event) - 2; 176 bt_store_16(event, 2, channel->local_cid); 177 event[4] = credits; 178 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 179 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 180 } 181 182 void l2cap_block_new_credits(uint8_t blocked){ 183 new_credits_blocked = blocked; 184 } 185 186 void l2cap_hand_out_credits(void){ 187 188 if (new_credits_blocked) return; // we're told not to. used by daemon 189 190 linked_item_t *it; 191 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 192 if (!hci_number_free_acl_slots()) return; 193 l2cap_channel_t * channel = (l2cap_channel_t *) it; 194 if (channel->state != L2CAP_STATE_OPEN) continue; 195 if (hci_number_outgoing_packets(channel->handle) < NR_BUFFERED_ACL_PACKETS && channel->packets_granted == 0) { 196 l2cap_emit_credits(channel, 1); 197 } 198 } 199 } 200 201 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 202 linked_item_t *it; 203 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 204 l2cap_channel_t * channel = (l2cap_channel_t *) it; 205 if ( channel->local_cid == local_cid) { 206 return channel; 207 } 208 } 209 return NULL; 210 } 211 212 int l2cap_can_send_packet_now(uint16_t local_cid){ 213 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 214 if (!channel) return 0; 215 if (!channel->packets_granted) return 0; 216 return hci_can_send_packet_now(HCI_ACL_DATA_PACKET); 217 } 218 219 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 220 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 221 if (channel) { 222 return channel->remote_mtu; 223 } 224 return 0; 225 } 226 227 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 228 229 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 230 log_info("l2cap_send_signaling_packet, cannot send\n"); 231 return BTSTACK_ACL_BUFFERS_FULL; 232 } 233 234 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 235 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 236 va_list argptr; 237 va_start(argptr, identifier); 238 uint16_t len = l2cap_create_signaling_internal(acl_buffer, handle, cmd, identifier, argptr); 239 va_end(argptr); 240 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 241 return hci_send_acl_packet(acl_buffer, len); 242 } 243 244 uint8_t *l2cap_get_outgoing_buffer(void){ 245 return hci_get_outgoing_acl_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 246 } 247 248 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 249 250 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 251 log_info("l2cap_send_internal cid %u, cannot send\n", local_cid); 252 return BTSTACK_ACL_BUFFERS_FULL; 253 } 254 255 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 256 if (!channel) { 257 log_error("l2cap_send_internal no channel for cid %u\n", local_cid); 258 return -1; // TODO: define error 259 } 260 261 if (channel->packets_granted == 0){ 262 log_error("l2cap_send_internal cid %u, no credits!\n", local_cid); 263 return -1; // TODO: define error 264 } 265 266 --channel->packets_granted; 267 268 log_debug("l2cap_send_internal cid %u, handle %u, 1 credit used, credits left %u;\n", 269 local_cid, channel->handle, channel->packets_granted); 270 271 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 272 273 // 0 - Connection handle : PB=10 : BC=00 274 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 275 // 2 - ACL length 276 bt_store_16(acl_buffer, 2, len + 4); 277 // 4 - L2CAP packet length 278 bt_store_16(acl_buffer, 4, len + 0); 279 // 6 - L2CAP channel DEST 280 bt_store_16(acl_buffer, 6, channel->remote_cid); 281 // send 282 int err = hci_send_acl_packet(acl_buffer, len+8); 283 284 l2cap_hand_out_credits(); 285 286 return err; 287 } 288 289 int l2cap_send_prepared_connectionless(uint16_t handle, uint16_t cid, uint16_t len){ 290 291 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 292 log_info("l2cap_send_prepared_to_handle cid %u, cannot send\n", cid); 293 return BTSTACK_ACL_BUFFERS_FULL; 294 } 295 296 log_debug("l2cap_send_prepared_to_handle cid %u, handle %u\n", cid, handle); 297 298 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 299 300 // 0 - Connection handle : PB=10 : BC=00 301 bt_store_16(acl_buffer, 0, handle | (2 << 12) | (0 << 14)); 302 // 2 - ACL length 303 bt_store_16(acl_buffer, 2, len + 4); 304 // 4 - L2CAP packet length 305 bt_store_16(acl_buffer, 4, len + 0); 306 // 6 - L2CAP channel DEST 307 bt_store_16(acl_buffer, 6, cid); 308 // send 309 int err = hci_send_acl_packet(acl_buffer, len+8); 310 311 l2cap_hand_out_credits(); 312 313 return err; 314 } 315 316 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 317 318 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 319 log_info("l2cap_send_internal cid %u, cannot send\n", local_cid); 320 return BTSTACK_ACL_BUFFERS_FULL; 321 } 322 323 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 324 325 memcpy(&acl_buffer[8], data, len); 326 327 return l2cap_send_prepared(local_cid, len); 328 } 329 330 int l2cap_send_connectionless(uint16_t handle, uint16_t cid, uint8_t *data, uint16_t len){ 331 332 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 333 log_info("l2cap_send_internal cid %u, cannot send\n", cid); 334 return BTSTACK_ACL_BUFFERS_FULL; 335 } 336 337 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 338 339 memcpy(&acl_buffer[8], data, len); 340 341 return l2cap_send_prepared_connectionless(handle, cid, len); 342 } 343 344 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 345 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 346 } 347 348 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 349 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 350 } 351 352 353 354 // MARK: L2CAP_RUN 355 // process outstanding signaling tasks 356 void l2cap_run(void){ 357 358 // check pending signaling responses 359 while (signaling_responses_pending){ 360 361 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)) break; 362 363 hci_con_handle_t handle = signaling_responses[0].handle; 364 uint8_t sig_id = signaling_responses[0].sig_id; 365 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 366 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST 367 368 switch (signaling_responses[0].code){ 369 case CONNECTION_REQUEST: 370 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 371 break; 372 case ECHO_REQUEST: 373 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 374 break; 375 case INFORMATION_REQUEST: 376 if (infoType == 2) { 377 uint32_t features = 0; 378 // extended features request supported, however no features present 379 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, 4, &features); 380 } else { 381 // all other types are not supported 382 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 383 } 384 break; 385 default: 386 // should not happen 387 break; 388 } 389 390 // remove first item 391 signaling_responses_pending--; 392 int i; 393 for (i=0; i < signaling_responses_pending; i++){ 394 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 395 } 396 } 397 398 uint8_t config_options[4]; 399 linked_item_t *it; 400 linked_item_t *next; 401 for (it = (linked_item_t *) l2cap_channels; it ; it = next){ 402 next = it->next; // cache next item as current item might get freed 403 404 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 405 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)) break; 406 407 l2cap_channel_t * channel = (l2cap_channel_t *) it; 408 409 // log_info("l2cap_run: state %u, var 0x%02x\n", channel->state, channel->state_var); 410 411 412 switch (channel->state){ 413 414 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 415 // send connection request - set state first 416 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 417 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 418 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 419 break; 420 421 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 422 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, channel->reason, 0); 423 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 424 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); // -- remove from list 425 btstack_memory_l2cap_channel_free(channel); 426 break; 427 428 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 429 channel->state = L2CAP_STATE_CONFIG; 430 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 431 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 432 break; 433 434 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 435 // success, start l2cap handshake 436 channel->local_sig_id = l2cap_next_sig_id(); 437 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 438 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 439 break; 440 441 case L2CAP_STATE_CONFIG: 442 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 443 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 444 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 445 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, 0, 0, 0, NULL); 446 } 447 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 448 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 449 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 450 channel->local_sig_id = l2cap_next_sig_id(); 451 config_options[0] = 1; // MTU 452 config_options[1] = 2; // len param 453 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 454 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 455 } 456 if (l2cap_channel_ready_for_open(channel)){ 457 channel->state = L2CAP_STATE_OPEN; 458 l2cap_emit_channel_opened(channel, 0); // success 459 l2cap_emit_credits(channel, 1); 460 } 461 break; 462 463 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 464 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 465 l2cap_finialize_channel_close(channel); // -- remove from list 466 break; 467 468 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 469 channel->local_sig_id = l2cap_next_sig_id(); 470 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 471 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 472 break; 473 default: 474 break; 475 } 476 } 477 } 478 479 uint16_t l2cap_max_mtu(void){ 480 return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE; 481 } 482 483 // open outgoing L2CAP channel 484 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 485 bd_addr_t address, uint16_t psm, uint16_t mtu){ 486 487 // alloc structure 488 l2cap_channel_t * chan = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 489 if (!chan) { 490 // emit error event 491 l2cap_channel_t dummy_channel; 492 BD_ADDR_COPY(dummy_channel.address, address); 493 dummy_channel.psm = psm; 494 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 495 return; 496 } 497 // limit local mtu to max acl packet length 498 if (mtu > l2cap_max_mtu()) { 499 mtu = l2cap_max_mtu(); 500 } 501 502 // fill in 503 BD_ADDR_COPY(chan->address, address); 504 chan->psm = psm; 505 chan->handle = 0; 506 chan->connection = connection; 507 chan->packet_handler = packet_handler; 508 chan->remote_mtu = L2CAP_MINIMAL_MTU; 509 chan->local_mtu = mtu; 510 chan->packets_granted = 0; 511 512 // set initial state 513 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 514 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 515 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 516 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 517 518 // add to connections list 519 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 520 521 l2cap_run(); 522 } 523 524 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 525 // find channel for local_cid 526 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 527 if (channel) { 528 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 529 } 530 // process 531 l2cap_run(); 532 } 533 534 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 535 linked_item_t *it = (linked_item_t *) &l2cap_channels; 536 while (it->next){ 537 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 538 if ( ! BD_ADDR_CMP( channel->address, address) ){ 539 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 540 // failure, forward error code 541 l2cap_emit_channel_opened(channel, status); 542 // discard channel 543 it->next = it->next->next; 544 btstack_memory_l2cap_channel_free(channel); 545 } 546 } else { 547 it = it->next; 548 } 549 } 550 } 551 552 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 553 linked_item_t *it; 554 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 555 l2cap_channel_t * channel = (l2cap_channel_t *) it; 556 if ( ! BD_ADDR_CMP( channel->address, address) ){ 557 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 558 // success, start l2cap handshake 559 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 560 channel->handle = handle; 561 channel->local_cid = l2cap_next_local_cid(); 562 } 563 } 564 } 565 // process 566 l2cap_run(); 567 } 568 569 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 570 571 bd_addr_t address; 572 hci_con_handle_t handle; 573 l2cap_channel_t * channel; 574 linked_item_t *it; 575 int hci_con_used; 576 577 switch(packet[0]){ 578 579 // handle connection complete events 580 case HCI_EVENT_CONNECTION_COMPLETE: 581 bt_flip_addr(address, &packet[5]); 582 if (packet[2] == 0){ 583 handle = READ_BT_16(packet, 3); 584 l2cap_handle_connection_success_for_addr(address, handle); 585 } else { 586 l2cap_handle_connection_failed_for_addr(address, packet[2]); 587 } 588 break; 589 590 // handle successful create connection cancel command 591 case HCI_EVENT_COMMAND_COMPLETE: 592 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 593 if (packet[5] == 0){ 594 bt_flip_addr(address, &packet[6]); 595 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 596 l2cap_handle_connection_failed_for_addr(address, 0x16); 597 } 598 } 599 l2cap_run(); // try sending signaling packets first 600 break; 601 602 case HCI_EVENT_COMMAND_STATUS: 603 l2cap_run(); // try sending signaling packets first 604 break; 605 606 // handle disconnection complete events 607 case HCI_EVENT_DISCONNECTION_COMPLETE: 608 // send l2cap disconnect events for all channels on this handle 609 handle = READ_BT_16(packet, 3); 610 it = (linked_item_t *) &l2cap_channels; 611 while (it->next){ 612 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 613 if ( channel->handle == handle ){ 614 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 615 it->next = it->next->next; 616 l2cap_emit_channel_closed(channel); 617 btstack_memory_l2cap_channel_free(channel); 618 } else { 619 it = it->next; 620 } 621 } 622 break; 623 624 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 625 l2cap_run(); // try sending signaling packets first 626 l2cap_hand_out_credits(); 627 break; 628 629 // HCI Connection Timeouts 630 case L2CAP_EVENT_TIMEOUT_CHECK: 631 handle = READ_BT_16(packet, 2); 632 if (hci_authentication_active_for_handle(handle)) break; 633 hci_con_used = 0; 634 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 635 channel = (l2cap_channel_t *) it; 636 if (channel->handle == handle) { 637 hci_con_used = 1; 638 } 639 } 640 if (hci_con_used) break; 641 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 642 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 643 break; 644 645 case DAEMON_EVENT_HCI_PACKET_SENT: 646 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 647 channel = (l2cap_channel_t *) it; 648 if (channel->packet_handler) { 649 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 650 } 651 } 652 if (attribute_protocol_packet_handler) { 653 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 654 } 655 if (security_protocol_packet_handler) { 656 (*security_protocol_packet_handler)(SM_DATA_PACKET, 0, packet, size); 657 } 658 break; 659 660 default: 661 break; 662 } 663 664 // pass on 665 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 666 } 667 668 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 669 channel->remote_sig_id = identifier; 670 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 671 l2cap_run(); 672 } 673 674 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 675 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 676 signaling_responses[signaling_responses_pending].handle = handle; 677 signaling_responses[signaling_responses_pending].code = code; 678 signaling_responses[signaling_responses_pending].sig_id = sig_id; 679 signaling_responses[signaling_responses_pending].data = data; 680 signaling_responses_pending++; 681 l2cap_run(); 682 } 683 } 684 685 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 686 687 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid %u\n", handle, psm, source_cid); 688 l2cap_service_t *service = l2cap_get_service(psm); 689 if (!service) { 690 // 0x0002 PSM not supported 691 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 692 return; 693 } 694 695 hci_connection_t * hci_connection = connection_for_handle( handle ); 696 if (!hci_connection) { 697 // 698 log_error("no hci_connection for handle %u\n", handle); 699 return; 700 } 701 // alloc structure 702 // log_info("l2cap_handle_connection_request register channel\n"); 703 l2cap_channel_t * channel = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 704 if (!channel){ 705 // 0x0004 No resources available 706 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 707 return; 708 } 709 710 // fill in 711 BD_ADDR_COPY(channel->address, hci_connection->address); 712 channel->psm = psm; 713 channel->handle = handle; 714 channel->connection = service->connection; 715 channel->packet_handler = service->packet_handler; 716 channel->local_cid = l2cap_next_local_cid(); 717 channel->remote_cid = source_cid; 718 channel->local_mtu = service->mtu; 719 channel->remote_mtu = L2CAP_DEFAULT_MTU; 720 channel->packets_granted = 0; 721 channel->remote_sig_id = sig_id; 722 723 // limit local mtu to max acl packet length 724 if (channel->local_mtu > l2cap_max_mtu()) { 725 channel->local_mtu = l2cap_max_mtu(); 726 } 727 728 // set initial state 729 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 730 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 731 732 // add to connections list 733 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 734 735 // emit incoming connection request 736 l2cap_emit_connection_request(channel); 737 } 738 739 void l2cap_accept_connection_internal(uint16_t local_cid){ 740 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 741 if (!channel) { 742 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 743 return; 744 } 745 746 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 747 748 // process 749 l2cap_run(); 750 } 751 752 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 753 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 754 if (!channel) { 755 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 756 return; 757 } 758 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 759 channel->reason = reason; 760 l2cap_run(); 761 } 762 763 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 764 765 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 766 767 // accept the other's configuration options 768 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 769 uint16_t pos = 8; 770 while (pos < end_pos){ 771 uint8_t type = command[pos++]; 772 uint8_t length = command[pos++]; 773 // MTU { type(8): 1, len(8):2, MTU(16) } 774 if ((type & 0x7f) == 1 && length == 2){ 775 channel->remote_mtu = READ_BT_16(command, pos); 776 // log_info("l2cap cid %u, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 777 } 778 pos += length; 779 } 780 } 781 782 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 783 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 784 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 785 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 786 return 1; 787 } 788 789 790 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 791 792 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 793 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 794 uint16_t result = 0; 795 796 log_info("L2CAP signaling handler code %u, state %u\n", code, channel->state); 797 798 // handle DISCONNECT REQUESTS seperately 799 if (code == DISCONNECTION_REQUEST){ 800 switch (channel->state){ 801 case L2CAP_STATE_CONFIG: 802 case L2CAP_STATE_OPEN: 803 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 804 case L2CAP_STATE_WAIT_DISCONNECT: 805 l2cap_handle_disconnect_request(channel, identifier); 806 break; 807 808 default: 809 // ignore in other states 810 break; 811 } 812 return; 813 } 814 815 // @STATEMACHINE(l2cap) 816 switch (channel->state) { 817 818 case L2CAP_STATE_WAIT_CONNECT_RSP: 819 switch (code){ 820 case CONNECTION_RESPONSE: 821 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 822 switch (result) { 823 case 0: 824 // successful connection 825 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 826 channel->state = L2CAP_STATE_CONFIG; 827 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 828 break; 829 case 1: 830 // connection pending. get some coffee 831 break; 832 default: 833 // channel closed 834 channel->state = L2CAP_STATE_CLOSED; 835 836 // map l2cap connection response result to BTstack status enumeration 837 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 838 839 // drop link key if security block 840 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 841 hci_drop_link_key_for_bd_addr(&channel->address); 842 } 843 844 // discard channel 845 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 846 btstack_memory_l2cap_channel_free(channel); 847 break; 848 } 849 break; 850 851 default: 852 //@TODO: implement other signaling packets 853 break; 854 } 855 break; 856 857 case L2CAP_STATE_CONFIG: 858 switch (code) { 859 case CONFIGURE_REQUEST: 860 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 861 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 862 l2cap_signaling_handle_configure_request(channel, command); 863 break; 864 case CONFIGURE_RESPONSE: 865 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 866 break; 867 default: 868 break; 869 } 870 if (l2cap_channel_ready_for_open(channel)){ 871 // for open: 872 channel->state = L2CAP_STATE_OPEN; 873 l2cap_emit_channel_opened(channel, 0); 874 l2cap_emit_credits(channel, 1); 875 } 876 break; 877 878 case L2CAP_STATE_WAIT_DISCONNECT: 879 switch (code) { 880 case DISCONNECTION_RESPONSE: 881 l2cap_finialize_channel_close(channel); 882 break; 883 default: 884 //@TODO: implement other signaling packets 885 break; 886 } 887 break; 888 889 case L2CAP_STATE_CLOSED: 890 // @TODO handle incoming requests 891 break; 892 893 case L2CAP_STATE_OPEN: 894 //@TODO: implement other signaling packets, e.g. re-configure 895 break; 896 default: 897 break; 898 } 899 // log_info("new state %u\n", channel->state); 900 } 901 902 903 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 904 905 // get code, signalind identifier and command len 906 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 907 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 908 909 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 910 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 911 return; 912 } 913 914 // general commands without an assigned channel 915 switch(code) { 916 917 case CONNECTION_REQUEST: { 918 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 919 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 920 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 921 return; 922 } 923 924 case ECHO_REQUEST: 925 l2cap_register_signaling_response(handle, code, sig_id, 0); 926 return; 927 928 case INFORMATION_REQUEST: { 929 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 930 l2cap_register_signaling_response(handle, code, sig_id, infoType); 931 return; 932 } 933 934 default: 935 break; 936 } 937 938 939 // Get potential destination CID 940 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 941 942 // Find channel for this sig_id and connection handle 943 linked_item_t *it; 944 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 945 l2cap_channel_t * channel = (l2cap_channel_t *) it; 946 if (channel->handle == handle) { 947 if (code & 1) { 948 // match odd commands (responses) by previous signaling identifier 949 if (channel->local_sig_id == sig_id) { 950 l2cap_signaling_handler_channel(channel, command); 951 break; 952 } 953 } else { 954 // match even commands (requests) by local channel id 955 if (channel->local_cid == dest_cid) { 956 l2cap_signaling_handler_channel(channel, command); 957 break; 958 } 959 } 960 } 961 } 962 } 963 964 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 965 966 // Get Channel ID 967 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 968 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 969 970 switch (channel_id) { 971 972 case L2CAP_CID_SIGNALING: { 973 974 uint16_t command_offset = 8; 975 while (command_offset < size) { 976 977 // handle signaling commands 978 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 979 980 // increment command_offset 981 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 982 } 983 break; 984 } 985 986 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 987 if (attribute_protocol_packet_handler) { 988 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 989 } 990 break; 991 992 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 993 if (security_protocol_packet_handler) { 994 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 995 } 996 break; 997 998 default: { 999 // Find channel for this channel_id and connection handle 1000 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1001 if (channel) { 1002 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1003 } 1004 break; 1005 } 1006 } 1007 1008 l2cap_run(); 1009 } 1010 1011 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1012 switch (packet_type) { 1013 case HCI_EVENT_PACKET: 1014 l2cap_event_handler(packet, size); 1015 break; 1016 case HCI_ACL_DATA_PACKET: 1017 l2cap_acl_handler(packet, size); 1018 break; 1019 default: 1020 break; 1021 } 1022 } 1023 1024 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1025 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1026 channel->state = L2CAP_STATE_CLOSED; 1027 l2cap_emit_channel_closed(channel); 1028 // discard channel 1029 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1030 btstack_memory_l2cap_channel_free(channel); 1031 } 1032 1033 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1034 linked_item_t *it; 1035 1036 // close open channels 1037 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 1038 l2cap_service_t * service = ((l2cap_service_t *) it); 1039 if ( service->psm == psm){ 1040 return service; 1041 }; 1042 } 1043 return NULL; 1044 } 1045 1046 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 1047 // check for alread registered psm 1048 // TODO: emit error event 1049 l2cap_service_t *service = l2cap_get_service(psm); 1050 if (service) { 1051 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 1052 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1053 return; 1054 } 1055 1056 // alloc structure 1057 // TODO: emit error event 1058 service = (l2cap_service_t *) btstack_memory_l2cap_service_get(); 1059 if (!service) { 1060 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 1061 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1062 return; 1063 } 1064 1065 // fill in 1066 service->psm = psm; 1067 service->mtu = mtu; 1068 service->connection = connection; 1069 service->packet_handler = packet_handler; 1070 1071 // add to services list 1072 linked_list_add(&l2cap_services, (linked_item_t *) service); 1073 1074 // enable page scan 1075 hci_connectable_control(1); 1076 1077 // done 1078 l2cap_emit_service_registered(connection, 0, psm); 1079 } 1080 1081 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1082 l2cap_service_t *service = l2cap_get_service(psm); 1083 if (!service) return; 1084 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1085 btstack_memory_l2cap_service_free(service); 1086 1087 // disable page scan when no services registered 1088 if (!linked_list_empty(&l2cap_services)) return; 1089 hci_connectable_control(0); 1090 } 1091 1092 // 1093 void l2cap_close_connection(void *connection){ 1094 linked_item_t *it; 1095 1096 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 1097 l2cap_channel_t * channel; 1098 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1099 channel = (l2cap_channel_t *) it; 1100 if (channel->connection == connection) { 1101 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1102 } 1103 } 1104 1105 // unregister services 1106 it = (linked_item_t *) &l2cap_services; 1107 while (it->next) { 1108 l2cap_service_t * service = (l2cap_service_t *) it->next; 1109 if (service->connection == connection){ 1110 it->next = it->next->next; 1111 btstack_memory_l2cap_service_free(service); 1112 } else { 1113 it = it->next; 1114 } 1115 } 1116 1117 // process 1118 l2cap_run(); 1119 } 1120 1121 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1122 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1123 switch(channel_id){ 1124 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1125 attribute_protocol_packet_handler = packet_handler; 1126 break; 1127 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1128 security_protocol_packet_handler = packet_handler; 1129 break; 1130 } 1131 } 1132 1133