1 /* 2 * Copyright (C) 2009-2012 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 * 4. Any redistribution, use, or modification is done solely for 17 * personal benefit and not for any commercial purpose or for 18 * monetary gain. 19 * 20 * THIS SOFTWARE IS PROVIDED BY MATTHIAS RINGWALD AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS 24 * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 27 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 30 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * Please inquire about commercial licensing options at [email protected] 34 * 35 */ 36 37 /* 38 * l2cap.c 39 * 40 * Logical Link Control and Adaption Protocl (L2CAP) 41 * 42 * Created by Matthias Ringwald on 5/16/09. 43 */ 44 45 #include "l2cap.h" 46 #include "hci.h" 47 #include "hci_dump.h" 48 #include "debug.h" 49 #include "btstack_memory.h" 50 51 #include <stdarg.h> 52 #include <string.h> 53 54 #include <stdio.h> 55 56 // nr of buffered acl packets in outgoing queue to get max performance 57 #define NR_BUFFERED_ACL_PACKETS 3 58 59 // used to cache l2cap rejects, echo, and informational requests 60 #define NR_PENDING_SIGNALING_RESPONSES 3 61 62 // offsets for L2CAP SIGNALING COMMANDS 63 #define L2CAP_SIGNALING_COMMAND_CODE_OFFSET 0 64 #define L2CAP_SIGNALING_COMMAND_SIGID_OFFSET 1 65 #define L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET 2 66 #define L2CAP_SIGNALING_COMMAND_DATA_OFFSET 4 67 68 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size); 69 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size); 70 71 // used to cache l2cap rejects, echo, and informational requests 72 static l2cap_signaling_response_t signaling_responses[NR_PENDING_SIGNALING_RESPONSES]; 73 static int signaling_responses_pending; 74 75 static linked_list_t l2cap_channels = NULL; 76 static linked_list_t l2cap_services = NULL; 77 static void (*packet_handler) (void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size) = null_packet_handler; 78 static int new_credits_blocked = 0; 79 80 static btstack_packet_handler_t attribute_protocol_packet_handler = NULL; 81 static btstack_packet_handler_t security_protocol_packet_handler = NULL; 82 83 // prototypes 84 static void l2cap_finialize_channel_close(l2cap_channel_t *channel); 85 static l2cap_service_t * l2cap_get_service(uint16_t psm); 86 static void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status); 87 static void l2cap_emit_channel_closed(l2cap_channel_t *channel); 88 static void l2cap_emit_connection_request(l2cap_channel_t *channel); 89 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); 90 91 92 void l2cap_init(){ 93 new_credits_blocked = 0; 94 signaling_responses_pending = 0; 95 96 l2cap_channels = NULL; 97 l2cap_services = NULL; 98 99 packet_handler = null_packet_handler; 100 101 // 102 // register callback with HCI 103 // 104 hci_register_packet_handler(&l2cap_packet_handler); 105 hci_connectable_control(0); // no services yet 106 } 107 108 109 /** Register L2CAP packet handlers */ 110 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 111 } 112 void l2cap_register_packet_handler(void (*handler)(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 113 packet_handler = handler; 114 } 115 116 // notify client/protocol handler 117 void l2cap_dispatch(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 118 if (channel->packet_handler) { 119 (* (channel->packet_handler))(type, channel->local_cid, data, size); 120 } else { 121 (*packet_handler)(channel->connection, type, channel->local_cid, data, size); 122 } 123 } 124 125 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 126 log_info("L2CAP_EVENT_CHANNEL_OPENED status 0x%x addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x local_mtu %u, remote_mtu %u, flush_timeout %u", 127 status, bd_addr_to_str(channel->address), channel->handle, channel->psm, 128 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 129 uint8_t event[23]; 130 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 131 event[1] = sizeof(event) - 2; 132 event[2] = status; 133 bt_flip_addr(&event[3], channel->address); 134 bt_store_16(event, 9, channel->handle); 135 bt_store_16(event, 11, channel->psm); 136 bt_store_16(event, 13, channel->local_cid); 137 bt_store_16(event, 15, channel->remote_cid); 138 bt_store_16(event, 17, channel->local_mtu); 139 bt_store_16(event, 19, channel->remote_mtu); 140 bt_store_16(event, 19, channel->flush_timeout); 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_channel_closed(l2cap_channel_t *channel) { 146 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 147 uint8_t event[4]; 148 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 149 event[1] = sizeof(event) - 2; 150 bt_store_16(event, 2, channel->local_cid); 151 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 152 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 153 } 154 155 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 156 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 157 bd_addr_to_str(channel->address), channel->handle, channel->psm, channel->local_cid, channel->remote_cid); 158 uint8_t event[16]; 159 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 160 event[1] = sizeof(event) - 2; 161 bt_flip_addr(&event[2], channel->address); 162 bt_store_16(event, 8, channel->handle); 163 bt_store_16(event, 10, channel->psm); 164 bt_store_16(event, 12, channel->local_cid); 165 bt_store_16(event, 14, channel->remote_cid); 166 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 167 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 168 } 169 170 static void l2cap_emit_service_registered(void *connection, uint8_t status, uint16_t psm){ 171 log_info("L2CAP_EVENT_SERVICE_REGISTERED status 0x%x psm 0x%x", status, psm); 172 uint8_t event[5]; 173 event[0] = L2CAP_EVENT_SERVICE_REGISTERED; 174 event[1] = sizeof(event) - 2; 175 event[2] = status; 176 bt_store_16(event, 3, psm); 177 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 178 (*packet_handler)(connection, HCI_EVENT_PACKET, 0, event, sizeof(event)); 179 } 180 181 void l2cap_emit_credits(l2cap_channel_t *channel, uint8_t credits) { 182 183 log_info("L2CAP_EVENT_CREDITS local_cid 0x%x credits %u", channel->local_cid, credits); 184 // track credits 185 channel->packets_granted += credits; 186 187 uint8_t event[5]; 188 event[0] = L2CAP_EVENT_CREDITS; 189 event[1] = sizeof(event) - 2; 190 bt_store_16(event, 2, channel->local_cid); 191 event[4] = credits; 192 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 193 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 194 } 195 196 void l2cap_block_new_credits(uint8_t blocked){ 197 new_credits_blocked = blocked; 198 } 199 200 void l2cap_hand_out_credits(void){ 201 202 if (new_credits_blocked) return; // we're told not to. used by daemon 203 204 linked_item_t *it; 205 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 206 if (!hci_number_free_acl_slots()) return; 207 l2cap_channel_t * channel = (l2cap_channel_t *) it; 208 if (channel->state != L2CAP_STATE_OPEN) continue; 209 if (hci_number_outgoing_packets(channel->handle) < NR_BUFFERED_ACL_PACKETS && channel->packets_granted == 0) { 210 l2cap_emit_credits(channel, 1); 211 } 212 } 213 } 214 215 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 216 linked_item_t *it; 217 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 218 l2cap_channel_t * channel = (l2cap_channel_t *) it; 219 if ( channel->local_cid == local_cid) { 220 return channel; 221 } 222 } 223 return NULL; 224 } 225 226 int l2cap_can_send_packet_now(uint16_t local_cid){ 227 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 228 if (!channel) return 0; 229 if (!channel->packets_granted) return 0; 230 return hci_can_send_packet_now(HCI_ACL_DATA_PACKET); 231 } 232 233 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 234 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 235 if (channel) { 236 return channel->remote_mtu; 237 } 238 return 0; 239 } 240 241 static l2cap_channel_t * l2cap_channel_for_rtx_timer(timer_source_t * ts){ 242 linked_item_t *it; 243 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 244 l2cap_channel_t * channel = (l2cap_channel_t *) it; 245 if ( &channel->rtx == ts) { 246 return channel; 247 } 248 } 249 return NULL; 250 } 251 252 static void l2cap_rtx_timeout(timer_source_t * ts){ 253 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 254 if (!ts) return; 255 256 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 257 258 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 259 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 260 // notify client 261 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 262 263 // discard channel 264 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 265 btstack_memory_l2cap_channel_free(channel); 266 } 267 268 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 269 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 270 run_loop_remove_timer(&channel->rtx); 271 } 272 273 static void l2cap_start_rtx(l2cap_channel_t * channel){ 274 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 275 l2cap_stop_rtx(channel); 276 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 277 run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 278 run_loop_add_timer(&channel->rtx); 279 } 280 281 static void l2cap_start_ertx(l2cap_channel_t * channel){ 282 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 283 l2cap_stop_rtx(channel); 284 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 285 run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 286 run_loop_add_timer(&channel->rtx); 287 } 288 289 290 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 291 292 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 293 log_info("l2cap_send_signaling_packet, cannot send\n"); 294 return BTSTACK_ACL_BUFFERS_FULL; 295 } 296 297 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 298 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 299 va_list argptr; 300 va_start(argptr, identifier); 301 uint16_t len = l2cap_create_signaling_internal(acl_buffer, handle, cmd, identifier, argptr); 302 va_end(argptr); 303 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 304 return hci_send_acl_packet(acl_buffer, len); 305 } 306 307 uint8_t *l2cap_get_outgoing_buffer(void){ 308 return hci_get_outgoing_acl_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 309 } 310 311 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 312 313 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 314 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", local_cid); 315 return BTSTACK_ACL_BUFFERS_FULL; 316 } 317 318 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 319 if (!channel) { 320 log_error("l2cap_send_internal no channel for cid 0x%02x\n", local_cid); 321 return -1; // TODO: define error 322 } 323 324 if (channel->packets_granted == 0){ 325 log_error("l2cap_send_internal cid 0x%02x, no credits!\n", local_cid); 326 return -1; // TODO: define error 327 } 328 329 --channel->packets_granted; 330 331 log_debug("l2cap_send_internal cid 0x%02x, handle %u, 1 credit used, credits left %u;\n", 332 local_cid, channel->handle, channel->packets_granted); 333 334 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 335 336 // 0 - Connection handle : PB=10 : BC=00 337 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 338 // 2 - ACL length 339 bt_store_16(acl_buffer, 2, len + 4); 340 // 4 - L2CAP packet length 341 bt_store_16(acl_buffer, 4, len + 0); 342 // 6 - L2CAP channel DEST 343 bt_store_16(acl_buffer, 6, channel->remote_cid); 344 // send 345 int err = hci_send_acl_packet(acl_buffer, len+8); 346 347 l2cap_hand_out_credits(); 348 349 return err; 350 } 351 352 int l2cap_send_prepared_connectionless(uint16_t handle, uint16_t cid, uint16_t len){ 353 354 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 355 log_info("l2cap_send_prepared_to_handle cid 0x%02x, cannot send\n", cid); 356 return BTSTACK_ACL_BUFFERS_FULL; 357 } 358 359 log_debug("l2cap_send_prepared_to_handle cid 0x%02x, handle %u\n", cid, handle); 360 361 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 362 363 // 0 - Connection handle : PB=10 : BC=00 364 bt_store_16(acl_buffer, 0, handle | (2 << 12) | (0 << 14)); 365 // 2 - ACL length 366 bt_store_16(acl_buffer, 2, len + 4); 367 // 4 - L2CAP packet length 368 bt_store_16(acl_buffer, 4, len + 0); 369 // 6 - L2CAP channel DEST 370 bt_store_16(acl_buffer, 6, cid); 371 // send 372 int err = hci_send_acl_packet(acl_buffer, len+8); 373 374 l2cap_hand_out_credits(); 375 376 return err; 377 } 378 379 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 380 381 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 382 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", local_cid); 383 return BTSTACK_ACL_BUFFERS_FULL; 384 } 385 386 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 387 388 memcpy(&acl_buffer[8], data, len); 389 390 return l2cap_send_prepared(local_cid, len); 391 } 392 393 int l2cap_send_connectionless(uint16_t handle, uint16_t cid, uint8_t *data, uint16_t len){ 394 395 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 396 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", cid); 397 return BTSTACK_ACL_BUFFERS_FULL; 398 } 399 400 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 401 402 memcpy(&acl_buffer[8], data, len); 403 404 return l2cap_send_prepared_connectionless(handle, cid, len); 405 } 406 407 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 408 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 409 } 410 411 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 412 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 413 } 414 415 416 417 // MARK: L2CAP_RUN 418 // process outstanding signaling tasks 419 void l2cap_run(void){ 420 421 // check pending signaling responses 422 while (signaling_responses_pending){ 423 424 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)) break; 425 426 hci_con_handle_t handle = signaling_responses[0].handle; 427 uint8_t sig_id = signaling_responses[0].sig_id; 428 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 429 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 430 431 switch (signaling_responses[0].code){ 432 case CONNECTION_REQUEST: 433 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 434 break; 435 case ECHO_REQUEST: 436 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 437 break; 438 case INFORMATION_REQUEST: 439 switch (infoType){ 440 case 1: { // Connectionless MTU 441 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 442 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 443 break; 444 } 445 case 2: { // Extended Features Supported 446 // extended features request supported, only supporing fixed channel map 447 uint32_t features = 0x80; 448 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 449 break; 450 } 451 case 3: { // Fixed Channels Supported 452 uint8_t map[8]; 453 memset(map, 0, 8); 454 map[0] = 0x01; // L2CAP Signaling Channel 455 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 456 break; 457 } 458 default: 459 // all other types are not supported 460 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 461 break; 462 } 463 break; 464 case COMMAND_REJECT: 465 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result); 466 break; 467 default: 468 // should not happen 469 break; 470 } 471 472 // remove first item 473 signaling_responses_pending--; 474 int i; 475 for (i=0; i < signaling_responses_pending; i++){ 476 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 477 } 478 } 479 480 uint8_t config_options[4]; 481 linked_item_t *it; 482 linked_item_t *next; 483 for (it = (linked_item_t *) l2cap_channels; it ; it = next){ 484 next = it->next; // cache next item as current item might get freed 485 486 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 487 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)) break; 488 489 l2cap_channel_t * channel = (l2cap_channel_t *) it; 490 491 // log_info("l2cap_run: state %u, var 0x%02x\n", channel->state, channel->state_var); 492 493 494 switch (channel->state){ 495 496 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 497 // send connection request - set state first 498 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 499 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 500 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 501 break; 502 503 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 504 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, channel->reason, 0); 505 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 506 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); // -- remove from list 507 btstack_memory_l2cap_channel_free(channel); 508 break; 509 510 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_PENDING: 511 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 512 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1 , 0); 513 break; 514 515 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 516 channel->state = L2CAP_STATE_CONFIG; 517 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 518 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 519 break; 520 521 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 522 // success, start l2cap handshake 523 channel->local_sig_id = l2cap_next_sig_id(); 524 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 525 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 526 l2cap_start_rtx(channel); 527 break; 528 529 case L2CAP_STATE_CONFIG: 530 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 531 uint16_t flags = 0; 532 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 533 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 534 flags = 1; 535 } else { 536 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 537 } 538 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 539 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 540 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 541 config_options[0] = 1; // MTU 542 config_options[1] = 2; // len param 543 bt_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 544 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 545 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 546 } else { 547 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 548 } 549 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 550 } 551 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 552 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 553 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 554 channel->local_sig_id = l2cap_next_sig_id(); 555 config_options[0] = 1; // MTU 556 config_options[1] = 2; // len param 557 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 558 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 559 l2cap_start_rtx(channel); 560 } 561 if (l2cap_channel_ready_for_open(channel)){ 562 channel->state = L2CAP_STATE_OPEN; 563 l2cap_emit_channel_opened(channel, 0); // success 564 l2cap_emit_credits(channel, 1); 565 } 566 break; 567 568 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 569 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 570 // we don't start an RTX timer for a disconnect - there's no point in closing the channel if the other side doesn't respond :) 571 l2cap_finialize_channel_close(channel); // -- remove from list 572 break; 573 574 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 575 channel->local_sig_id = l2cap_next_sig_id(); 576 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 577 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 578 break; 579 default: 580 break; 581 } 582 } 583 } 584 585 uint16_t l2cap_max_mtu(void){ 586 return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE; 587 } 588 589 // open outgoing L2CAP channel 590 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 591 bd_addr_t address, uint16_t psm, uint16_t mtu){ 592 593 log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 594 595 // alloc structure 596 l2cap_channel_t * chan = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 597 if (!chan) { 598 // emit error event 599 l2cap_channel_t dummy_channel; 600 BD_ADDR_COPY(dummy_channel.address, address); 601 dummy_channel.psm = psm; 602 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 603 return; 604 } 605 // limit local mtu to max acl packet length 606 if (mtu > l2cap_max_mtu()) { 607 mtu = l2cap_max_mtu(); 608 } 609 610 // fill in 611 BD_ADDR_COPY(chan->address, address); 612 chan->psm = psm; 613 chan->handle = 0; 614 chan->connection = connection; 615 chan->packet_handler = packet_handler; 616 chan->remote_mtu = L2CAP_MINIMAL_MTU; 617 chan->local_mtu = mtu; 618 chan->packets_granted = 0; 619 620 // set initial state 621 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 622 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 623 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 624 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 625 626 // add to connections list 627 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 628 629 l2cap_run(); 630 } 631 632 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 633 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 634 // find channel for local_cid 635 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 636 if (channel) { 637 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 638 } 639 // process 640 l2cap_run(); 641 } 642 643 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 644 linked_item_t *it = (linked_item_t *) &l2cap_channels; 645 while (it->next){ 646 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 647 if ( ! BD_ADDR_CMP( channel->address, address) ){ 648 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 649 // failure, forward error code 650 l2cap_emit_channel_opened(channel, status); 651 // discard channel 652 it->next = it->next->next; 653 btstack_memory_l2cap_channel_free(channel); 654 } 655 } else { 656 it = it->next; 657 } 658 } 659 } 660 661 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 662 linked_item_t *it; 663 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 664 l2cap_channel_t * channel = (l2cap_channel_t *) it; 665 if ( ! BD_ADDR_CMP( channel->address, address) ){ 666 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 667 // success, start l2cap handshake 668 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 669 channel->handle = handle; 670 channel->local_cid = l2cap_next_local_cid(); 671 } 672 } 673 } 674 // process 675 l2cap_run(); 676 } 677 678 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 679 680 bd_addr_t address; 681 hci_con_handle_t handle; 682 l2cap_channel_t * channel; 683 linked_item_t *it; 684 int hci_con_used; 685 686 switch(packet[0]){ 687 688 // handle connection complete events 689 case HCI_EVENT_CONNECTION_COMPLETE: 690 bt_flip_addr(address, &packet[5]); 691 if (packet[2] == 0){ 692 handle = READ_BT_16(packet, 3); 693 l2cap_handle_connection_success_for_addr(address, handle); 694 } else { 695 l2cap_handle_connection_failed_for_addr(address, packet[2]); 696 } 697 break; 698 699 // handle successful create connection cancel command 700 case HCI_EVENT_COMMAND_COMPLETE: 701 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 702 if (packet[5] == 0){ 703 bt_flip_addr(address, &packet[6]); 704 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 705 l2cap_handle_connection_failed_for_addr(address, 0x16); 706 } 707 } 708 l2cap_run(); // try sending signaling packets first 709 break; 710 711 case HCI_EVENT_COMMAND_STATUS: 712 l2cap_run(); // try sending signaling packets first 713 break; 714 715 // handle disconnection complete events 716 case HCI_EVENT_DISCONNECTION_COMPLETE: 717 // send l2cap disconnect events for all channels on this handle 718 handle = READ_BT_16(packet, 3); 719 it = (linked_item_t *) &l2cap_channels; 720 while (it->next){ 721 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 722 if ( channel->handle == handle ){ 723 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 724 it->next = it->next->next; 725 l2cap_emit_channel_closed(channel); 726 btstack_memory_l2cap_channel_free(channel); 727 } else { 728 it = it->next; 729 } 730 } 731 break; 732 733 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 734 l2cap_run(); // try sending signaling packets first 735 l2cap_hand_out_credits(); 736 break; 737 738 // HCI Connection Timeouts 739 case L2CAP_EVENT_TIMEOUT_CHECK: 740 handle = READ_BT_16(packet, 2); 741 if (hci_authentication_active_for_handle(handle)) break; 742 hci_con_used = 0; 743 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 744 channel = (l2cap_channel_t *) it; 745 if (channel->handle == handle) { 746 hci_con_used = 1; 747 } 748 } 749 if (hci_con_used) break; 750 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 751 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 752 break; 753 754 case DAEMON_EVENT_HCI_PACKET_SENT: 755 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 756 channel = (l2cap_channel_t *) it; 757 if (channel->packet_handler) { 758 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 759 } 760 } 761 if (attribute_protocol_packet_handler) { 762 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 763 } 764 if (security_protocol_packet_handler) { 765 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 766 } 767 break; 768 769 default: 770 break; 771 } 772 773 // pass on 774 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 775 } 776 777 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 778 channel->remote_sig_id = identifier; 779 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 780 l2cap_run(); 781 } 782 783 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 784 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 785 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 786 signaling_responses[signaling_responses_pending].handle = handle; 787 signaling_responses[signaling_responses_pending].code = code; 788 signaling_responses[signaling_responses_pending].sig_id = sig_id; 789 signaling_responses[signaling_responses_pending].data = data; 790 signaling_responses_pending++; 791 l2cap_run(); 792 } 793 } 794 795 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 796 797 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x\n", handle, psm, source_cid); 798 l2cap_service_t *service = l2cap_get_service(psm); 799 if (!service) { 800 // 0x0002 PSM not supported 801 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 802 return; 803 } 804 805 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 806 if (!hci_connection) { 807 // 808 log_error("no hci_connection for handle %u\n", handle); 809 return; 810 } 811 // alloc structure 812 // log_info("l2cap_handle_connection_request register channel\n"); 813 l2cap_channel_t * channel = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 814 if (!channel){ 815 // 0x0004 No resources available 816 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 817 return; 818 } 819 820 // fill in 821 BD_ADDR_COPY(channel->address, hci_connection->address); 822 channel->psm = psm; 823 channel->handle = handle; 824 channel->connection = service->connection; 825 channel->packet_handler = service->packet_handler; 826 channel->local_cid = l2cap_next_local_cid(); 827 channel->remote_cid = source_cid; 828 channel->local_mtu = service->mtu; 829 channel->remote_mtu = L2CAP_DEFAULT_MTU; 830 channel->packets_granted = 0; 831 channel->remote_sig_id = sig_id; 832 833 // limit local mtu to max acl packet length 834 if (channel->local_mtu > l2cap_max_mtu()) { 835 channel->local_mtu = l2cap_max_mtu(); 836 } 837 838 // set initial state 839 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_PENDING; 840 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 841 842 // add to connections list 843 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 844 845 // emit incoming connection request 846 l2cap_emit_connection_request(channel); 847 } 848 849 void l2cap_accept_connection_internal(uint16_t local_cid){ 850 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 851 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 852 if (!channel) { 853 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 854 return; 855 } 856 857 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 858 859 // process 860 l2cap_run(); 861 } 862 863 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 864 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); 865 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 866 if (!channel) { 867 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 868 return; 869 } 870 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 871 channel->reason = reason; 872 l2cap_run(); 873 } 874 875 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 876 877 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 878 879 uint16_t flags = READ_BT_16(command, 6); 880 if (flags & 1) { 881 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 882 } 883 884 // accept the other's configuration options 885 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 886 uint16_t pos = 8; 887 while (pos < end_pos){ 888 uint8_t option_hint = command[pos] >> 7; 889 uint8_t option_type = command[pos] & 0x7f; 890 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 891 pos++; 892 uint8_t length = command[pos++]; 893 // MTU { type(8): 1, len(8):2, MTU(16) } 894 if (option_type == 1 && length == 2){ 895 channel->remote_mtu = READ_BT_16(command, pos); 896 // log_info("l2cap cid 0x%02x, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 897 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 898 } 899 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 900 if (option_type == 2 && length == 2){ 901 channel->flush_timeout = READ_BT_16(command, pos); 902 } 903 // check for unknown options 904 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 905 log_info("l2cap cid %u, unknown options", channel->local_cid); 906 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 907 } 908 pos += length; 909 } 910 } 911 912 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 913 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 914 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 915 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 916 return 1; 917 } 918 919 920 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 921 922 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 923 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 924 uint16_t result = 0; 925 926 log_info("L2CAP signaling handler code %u, state %u\n", code, channel->state); 927 928 // handle DISCONNECT REQUESTS seperately 929 if (code == DISCONNECTION_REQUEST){ 930 switch (channel->state){ 931 case L2CAP_STATE_CONFIG: 932 case L2CAP_STATE_OPEN: 933 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 934 case L2CAP_STATE_WAIT_DISCONNECT: 935 l2cap_handle_disconnect_request(channel, identifier); 936 break; 937 938 default: 939 // ignore in other states 940 break; 941 } 942 return; 943 } 944 945 // @STATEMACHINE(l2cap) 946 switch (channel->state) { 947 948 case L2CAP_STATE_WAIT_CONNECT_RSP: 949 switch (code){ 950 case CONNECTION_RESPONSE: 951 l2cap_stop_rtx(channel); 952 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 953 switch (result) { 954 case 0: 955 // successful connection 956 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 957 channel->state = L2CAP_STATE_CONFIG; 958 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 959 break; 960 case 1: 961 // connection pending. get some coffee, but start the ERTX 962 l2cap_start_ertx(channel); 963 break; 964 default: 965 // channel closed 966 channel->state = L2CAP_STATE_CLOSED; 967 // map l2cap connection response result to BTstack status enumeration 968 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 969 970 // drop link key if security block 971 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 972 hci_drop_link_key_for_bd_addr(&channel->address); 973 } 974 975 // discard channel 976 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 977 btstack_memory_l2cap_channel_free(channel); 978 break; 979 } 980 break; 981 982 default: 983 //@TODO: implement other signaling packets 984 break; 985 } 986 break; 987 988 case L2CAP_STATE_CONFIG: 989 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 990 switch (code) { 991 case CONFIGURE_REQUEST: 992 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 993 l2cap_signaling_handle_configure_request(channel, command); 994 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 995 // only done if continuation not set 996 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 997 } 998 break; 999 case CONFIGURE_RESPONSE: 1000 l2cap_stop_rtx(channel); 1001 switch (result){ 1002 case 0: // success 1003 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1004 break; 1005 case 4: // pending 1006 l2cap_start_ertx(channel); 1007 break; 1008 default: 1009 // retry on negative result 1010 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1011 break; 1012 } 1013 break; 1014 default: 1015 break; 1016 } 1017 if (l2cap_channel_ready_for_open(channel)){ 1018 // for open: 1019 channel->state = L2CAP_STATE_OPEN; 1020 l2cap_emit_channel_opened(channel, 0); 1021 l2cap_emit_credits(channel, 1); 1022 } 1023 break; 1024 1025 case L2CAP_STATE_WAIT_DISCONNECT: 1026 switch (code) { 1027 case DISCONNECTION_RESPONSE: 1028 l2cap_finialize_channel_close(channel); 1029 break; 1030 default: 1031 //@TODO: implement other signaling packets 1032 break; 1033 } 1034 break; 1035 1036 case L2CAP_STATE_CLOSED: 1037 // @TODO handle incoming requests 1038 break; 1039 1040 case L2CAP_STATE_OPEN: 1041 //@TODO: implement other signaling packets, e.g. re-configure 1042 break; 1043 default: 1044 break; 1045 } 1046 // log_info("new state %u\n", channel->state); 1047 } 1048 1049 1050 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1051 1052 // get code, signalind identifier and command len 1053 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1054 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1055 1056 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1057 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1058 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1059 return; 1060 } 1061 1062 // general commands without an assigned channel 1063 switch(code) { 1064 1065 case CONNECTION_REQUEST: { 1066 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1067 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1068 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1069 return; 1070 } 1071 1072 case ECHO_REQUEST: 1073 l2cap_register_signaling_response(handle, code, sig_id, 0); 1074 return; 1075 1076 case INFORMATION_REQUEST: { 1077 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1078 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1079 return; 1080 } 1081 1082 default: 1083 break; 1084 } 1085 1086 1087 // Get potential destination CID 1088 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1089 1090 // Find channel for this sig_id and connection handle 1091 linked_item_t *it; 1092 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1093 l2cap_channel_t * channel = (l2cap_channel_t *) it; 1094 if (channel->handle == handle) { 1095 if (code & 1) { 1096 // match odd commands (responses) by previous signaling identifier 1097 if (channel->local_sig_id == sig_id) { 1098 l2cap_signaling_handler_channel(channel, command); 1099 break; 1100 } 1101 } else { 1102 // match even commands (requests) by local channel id 1103 if (channel->local_cid == dest_cid) { 1104 l2cap_signaling_handler_channel(channel, command); 1105 break; 1106 } 1107 } 1108 } 1109 } 1110 } 1111 1112 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 1113 1114 // Get Channel ID 1115 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1116 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1117 1118 switch (channel_id) { 1119 1120 case L2CAP_CID_SIGNALING: { 1121 1122 uint16_t command_offset = 8; 1123 while (command_offset < size) { 1124 1125 // handle signaling commands 1126 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1127 1128 // increment command_offset 1129 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1130 } 1131 break; 1132 } 1133 1134 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1135 if (attribute_protocol_packet_handler) { 1136 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1137 } 1138 break; 1139 1140 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1141 if (security_protocol_packet_handler) { 1142 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1143 } 1144 break; 1145 1146 default: { 1147 // Find channel for this channel_id and connection handle 1148 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1149 if (channel) { 1150 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1151 } 1152 break; 1153 } 1154 } 1155 1156 l2cap_run(); 1157 } 1158 1159 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1160 switch (packet_type) { 1161 case HCI_EVENT_PACKET: 1162 l2cap_event_handler(packet, size); 1163 break; 1164 case HCI_ACL_DATA_PACKET: 1165 l2cap_acl_handler(packet, size); 1166 break; 1167 default: 1168 break; 1169 } 1170 } 1171 1172 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1173 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1174 channel->state = L2CAP_STATE_CLOSED; 1175 l2cap_emit_channel_closed(channel); 1176 // discard channel 1177 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1178 btstack_memory_l2cap_channel_free(channel); 1179 } 1180 1181 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1182 linked_item_t *it; 1183 1184 // close open channels 1185 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 1186 l2cap_service_t * service = ((l2cap_service_t *) it); 1187 if ( service->psm == psm){ 1188 return service; 1189 }; 1190 } 1191 return NULL; 1192 } 1193 1194 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 1195 1196 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1197 1198 // check for alread registered psm 1199 // TODO: emit error event 1200 l2cap_service_t *service = l2cap_get_service(psm); 1201 if (service) { 1202 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 1203 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1204 return; 1205 } 1206 1207 // alloc structure 1208 // TODO: emit error event 1209 service = (l2cap_service_t *) btstack_memory_l2cap_service_get(); 1210 if (!service) { 1211 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 1212 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1213 return; 1214 } 1215 1216 // fill in 1217 service->psm = psm; 1218 service->mtu = mtu; 1219 service->connection = connection; 1220 service->packet_handler = packet_handler; 1221 1222 // add to services list 1223 linked_list_add(&l2cap_services, (linked_item_t *) service); 1224 1225 // enable page scan 1226 hci_connectable_control(1); 1227 1228 // done 1229 l2cap_emit_service_registered(connection, 0, psm); 1230 } 1231 1232 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1233 1234 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1235 1236 l2cap_service_t *service = l2cap_get_service(psm); 1237 if (!service) return; 1238 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1239 btstack_memory_l2cap_service_free(service); 1240 1241 // disable page scan when no services registered 1242 if (!linked_list_empty(&l2cap_services)) return; 1243 hci_connectable_control(0); 1244 } 1245 1246 // 1247 void l2cap_close_connection(void *connection){ 1248 linked_item_t *it; 1249 1250 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 1251 l2cap_channel_t * channel; 1252 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1253 channel = (l2cap_channel_t *) it; 1254 if (channel->connection == connection) { 1255 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1256 } 1257 } 1258 1259 // unregister services 1260 it = (linked_item_t *) &l2cap_services; 1261 while (it->next) { 1262 l2cap_service_t * service = (l2cap_service_t *) it->next; 1263 if (service->connection == connection){ 1264 it->next = it->next->next; 1265 btstack_memory_l2cap_service_free(service); 1266 } else { 1267 it = it->next; 1268 } 1269 } 1270 1271 // process 1272 l2cap_run(); 1273 } 1274 1275 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1276 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1277 switch(channel_id){ 1278 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1279 attribute_protocol_packet_handler = packet_handler; 1280 break; 1281 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1282 security_protocol_packet_handler = packet_handler; 1283 break; 1284 } 1285 } 1286 1287 #ifdef HAVE_BLE 1288 // Request LE connection parameter update 1289 int l2cap_le_request_connection_parameter_update(uint16_t handle, uint16_t interval_min, uint16_t interval_max, uint16_t slave_latency, uint16_t timeout_multiplier){ 1290 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 1291 log_info("l2cap_send_signaling_packet, cannot send\n"); 1292 return BTSTACK_ACL_BUFFERS_FULL; 1293 } 1294 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 1295 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 1296 uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); 1297 return hci_send_acl_packet(acl_buffer, len); 1298 } 1299 #endif 1300 1301