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_ACCEPT: 511 channel->state = L2CAP_STATE_CONFIG; 512 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 513 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 514 break; 515 516 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 517 // success, start l2cap handshake 518 channel->local_sig_id = l2cap_next_sig_id(); 519 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 520 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 521 l2cap_start_rtx(channel); 522 break; 523 524 case L2CAP_STATE_CONFIG: 525 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 526 uint16_t flags = 0; 527 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 528 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 529 flags = 1; 530 } else { 531 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 532 } 533 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 534 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 535 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 536 config_options[0] = 1; // MTU 537 config_options[1] = 2; // len param 538 bt_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 539 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 540 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 541 } else { 542 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 543 } 544 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 545 } 546 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 547 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 548 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 549 channel->local_sig_id = l2cap_next_sig_id(); 550 config_options[0] = 1; // MTU 551 config_options[1] = 2; // len param 552 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 553 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 554 l2cap_start_rtx(channel); 555 } 556 if (l2cap_channel_ready_for_open(channel)){ 557 channel->state = L2CAP_STATE_OPEN; 558 l2cap_emit_channel_opened(channel, 0); // success 559 l2cap_emit_credits(channel, 1); 560 } 561 break; 562 563 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 564 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 565 // 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 :) 566 l2cap_finialize_channel_close(channel); // -- remove from list 567 break; 568 569 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 570 channel->local_sig_id = l2cap_next_sig_id(); 571 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 572 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 573 break; 574 default: 575 break; 576 } 577 } 578 } 579 580 uint16_t l2cap_max_mtu(void){ 581 return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE; 582 } 583 584 // open outgoing L2CAP channel 585 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 586 bd_addr_t address, uint16_t psm, uint16_t mtu){ 587 588 log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 589 590 // alloc structure 591 l2cap_channel_t * chan = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 592 if (!chan) { 593 // emit error event 594 l2cap_channel_t dummy_channel; 595 BD_ADDR_COPY(dummy_channel.address, address); 596 dummy_channel.psm = psm; 597 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 598 return; 599 } 600 // limit local mtu to max acl packet length 601 if (mtu > l2cap_max_mtu()) { 602 mtu = l2cap_max_mtu(); 603 } 604 605 // fill in 606 BD_ADDR_COPY(chan->address, address); 607 chan->psm = psm; 608 chan->handle = 0; 609 chan->connection = connection; 610 chan->packet_handler = packet_handler; 611 chan->remote_mtu = L2CAP_MINIMAL_MTU; 612 chan->local_mtu = mtu; 613 chan->packets_granted = 0; 614 615 // set initial state 616 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 617 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 618 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 619 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 620 621 // add to connections list 622 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 623 624 l2cap_run(); 625 } 626 627 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 628 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 629 // find channel for local_cid 630 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 631 if (channel) { 632 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 633 } 634 // process 635 l2cap_run(); 636 } 637 638 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 639 linked_item_t *it = (linked_item_t *) &l2cap_channels; 640 while (it->next){ 641 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 642 if ( ! BD_ADDR_CMP( channel->address, address) ){ 643 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 644 // failure, forward error code 645 l2cap_emit_channel_opened(channel, status); 646 // discard channel 647 it->next = it->next->next; 648 btstack_memory_l2cap_channel_free(channel); 649 } 650 } else { 651 it = it->next; 652 } 653 } 654 } 655 656 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 657 linked_item_t *it; 658 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 659 l2cap_channel_t * channel = (l2cap_channel_t *) it; 660 if ( ! BD_ADDR_CMP( channel->address, address) ){ 661 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 662 // success, start l2cap handshake 663 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 664 channel->handle = handle; 665 channel->local_cid = l2cap_next_local_cid(); 666 } 667 } 668 } 669 // process 670 l2cap_run(); 671 } 672 673 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 674 675 bd_addr_t address; 676 hci_con_handle_t handle; 677 l2cap_channel_t * channel; 678 linked_item_t *it; 679 int hci_con_used; 680 681 switch(packet[0]){ 682 683 // handle connection complete events 684 case HCI_EVENT_CONNECTION_COMPLETE: 685 bt_flip_addr(address, &packet[5]); 686 if (packet[2] == 0){ 687 handle = READ_BT_16(packet, 3); 688 l2cap_handle_connection_success_for_addr(address, handle); 689 } else { 690 l2cap_handle_connection_failed_for_addr(address, packet[2]); 691 } 692 break; 693 694 // handle successful create connection cancel command 695 case HCI_EVENT_COMMAND_COMPLETE: 696 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 697 if (packet[5] == 0){ 698 bt_flip_addr(address, &packet[6]); 699 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 700 l2cap_handle_connection_failed_for_addr(address, 0x16); 701 } 702 } 703 l2cap_run(); // try sending signaling packets first 704 break; 705 706 case HCI_EVENT_COMMAND_STATUS: 707 l2cap_run(); // try sending signaling packets first 708 break; 709 710 // handle disconnection complete events 711 case HCI_EVENT_DISCONNECTION_COMPLETE: 712 // send l2cap disconnect events for all channels on this handle 713 handle = READ_BT_16(packet, 3); 714 it = (linked_item_t *) &l2cap_channels; 715 while (it->next){ 716 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 717 if ( channel->handle == handle ){ 718 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 719 it->next = it->next->next; 720 l2cap_emit_channel_closed(channel); 721 btstack_memory_l2cap_channel_free(channel); 722 } else { 723 it = it->next; 724 } 725 } 726 break; 727 728 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 729 l2cap_run(); // try sending signaling packets first 730 l2cap_hand_out_credits(); 731 break; 732 733 // HCI Connection Timeouts 734 case L2CAP_EVENT_TIMEOUT_CHECK: 735 handle = READ_BT_16(packet, 2); 736 if (hci_authentication_active_for_handle(handle)) break; 737 hci_con_used = 0; 738 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 739 channel = (l2cap_channel_t *) it; 740 if (channel->handle == handle) { 741 hci_con_used = 1; 742 } 743 } 744 if (hci_con_used) break; 745 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 746 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 747 break; 748 749 case DAEMON_EVENT_HCI_PACKET_SENT: 750 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 751 channel = (l2cap_channel_t *) it; 752 if (channel->packet_handler) { 753 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 754 } 755 } 756 if (attribute_protocol_packet_handler) { 757 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 758 } 759 if (security_protocol_packet_handler) { 760 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 761 } 762 break; 763 764 default: 765 break; 766 } 767 768 // pass on 769 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 770 } 771 772 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 773 channel->remote_sig_id = identifier; 774 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 775 l2cap_run(); 776 } 777 778 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 779 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 780 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 781 signaling_responses[signaling_responses_pending].handle = handle; 782 signaling_responses[signaling_responses_pending].code = code; 783 signaling_responses[signaling_responses_pending].sig_id = sig_id; 784 signaling_responses[signaling_responses_pending].data = data; 785 signaling_responses_pending++; 786 l2cap_run(); 787 } 788 } 789 790 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 791 792 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x\n", handle, psm, source_cid); 793 l2cap_service_t *service = l2cap_get_service(psm); 794 if (!service) { 795 // 0x0002 PSM not supported 796 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 797 return; 798 } 799 800 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 801 if (!hci_connection) { 802 // 803 log_error("no hci_connection for handle %u\n", handle); 804 return; 805 } 806 // alloc structure 807 // log_info("l2cap_handle_connection_request register channel\n"); 808 l2cap_channel_t * channel = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 809 if (!channel){ 810 // 0x0004 No resources available 811 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 812 return; 813 } 814 815 // fill in 816 BD_ADDR_COPY(channel->address, hci_connection->address); 817 channel->psm = psm; 818 channel->handle = handle; 819 channel->connection = service->connection; 820 channel->packet_handler = service->packet_handler; 821 channel->local_cid = l2cap_next_local_cid(); 822 channel->remote_cid = source_cid; 823 channel->local_mtu = service->mtu; 824 channel->remote_mtu = L2CAP_DEFAULT_MTU; 825 channel->packets_granted = 0; 826 channel->remote_sig_id = sig_id; 827 828 // limit local mtu to max acl packet length 829 if (channel->local_mtu > l2cap_max_mtu()) { 830 channel->local_mtu = l2cap_max_mtu(); 831 } 832 833 // set initial state 834 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 835 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 836 837 // add to connections list 838 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 839 840 // emit incoming connection request 841 l2cap_emit_connection_request(channel); 842 } 843 844 void l2cap_accept_connection_internal(uint16_t local_cid){ 845 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 846 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 847 if (!channel) { 848 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 849 return; 850 } 851 852 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 853 854 // process 855 l2cap_run(); 856 } 857 858 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 859 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); 860 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 861 if (!channel) { 862 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 863 return; 864 } 865 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 866 channel->reason = reason; 867 l2cap_run(); 868 } 869 870 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 871 872 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 873 874 uint16_t flags = READ_BT_16(command, 6); 875 if (flags & 1) { 876 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 877 } 878 879 // accept the other's configuration options 880 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 881 uint16_t pos = 8; 882 while (pos < end_pos){ 883 uint8_t option_hint = command[pos] >> 7; 884 uint8_t option_type = command[pos] & 0x7f; 885 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 886 pos++; 887 uint8_t length = command[pos++]; 888 // MTU { type(8): 1, len(8):2, MTU(16) } 889 if (option_type == 1 && length == 2){ 890 channel->remote_mtu = READ_BT_16(command, pos); 891 // log_info("l2cap cid 0x%02x, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 892 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 893 } 894 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 895 if (option_type == 2 && length == 2){ 896 channel->flush_timeout = READ_BT_16(command, pos); 897 } 898 // check for unknown options 899 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 900 log_info("l2cap cid %u, unknown options", channel->local_cid); 901 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 902 } 903 pos += length; 904 } 905 } 906 907 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 908 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 909 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 910 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 911 return 1; 912 } 913 914 915 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 916 917 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 918 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 919 uint16_t result = 0; 920 921 log_info("L2CAP signaling handler code %u, state %u\n", code, channel->state); 922 923 // handle DISCONNECT REQUESTS seperately 924 if (code == DISCONNECTION_REQUEST){ 925 switch (channel->state){ 926 case L2CAP_STATE_CONFIG: 927 case L2CAP_STATE_OPEN: 928 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 929 case L2CAP_STATE_WAIT_DISCONNECT: 930 l2cap_handle_disconnect_request(channel, identifier); 931 break; 932 933 default: 934 // ignore in other states 935 break; 936 } 937 return; 938 } 939 940 // @STATEMACHINE(l2cap) 941 switch (channel->state) { 942 943 case L2CAP_STATE_WAIT_CONNECT_RSP: 944 switch (code){ 945 case CONNECTION_RESPONSE: 946 l2cap_stop_rtx(channel); 947 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 948 switch (result) { 949 case 0: 950 // successful connection 951 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 952 channel->state = L2CAP_STATE_CONFIG; 953 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 954 break; 955 case 1: 956 // connection pending. get some coffee, but start the ERTX 957 l2cap_start_ertx(channel); 958 break; 959 default: 960 // channel closed 961 channel->state = L2CAP_STATE_CLOSED; 962 // map l2cap connection response result to BTstack status enumeration 963 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 964 965 // drop link key if security block 966 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 967 hci_drop_link_key_for_bd_addr(&channel->address); 968 } 969 970 // discard channel 971 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 972 btstack_memory_l2cap_channel_free(channel); 973 break; 974 } 975 break; 976 977 default: 978 //@TODO: implement other signaling packets 979 break; 980 } 981 break; 982 983 case L2CAP_STATE_CONFIG: 984 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 985 switch (code) { 986 case CONFIGURE_REQUEST: 987 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 988 l2cap_signaling_handle_configure_request(channel, command); 989 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 990 // only done if continuation not set 991 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 992 } 993 break; 994 case CONFIGURE_RESPONSE: 995 l2cap_stop_rtx(channel); 996 switch (result){ 997 case 0: // success 998 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 999 break; 1000 case 4: // pending 1001 l2cap_start_ertx(channel); 1002 break; 1003 default: 1004 // retry on negative result 1005 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1006 break; 1007 } 1008 break; 1009 default: 1010 break; 1011 } 1012 if (l2cap_channel_ready_for_open(channel)){ 1013 // for open: 1014 channel->state = L2CAP_STATE_OPEN; 1015 l2cap_emit_channel_opened(channel, 0); 1016 l2cap_emit_credits(channel, 1); 1017 } 1018 break; 1019 1020 case L2CAP_STATE_WAIT_DISCONNECT: 1021 switch (code) { 1022 case DISCONNECTION_RESPONSE: 1023 l2cap_finialize_channel_close(channel); 1024 break; 1025 default: 1026 //@TODO: implement other signaling packets 1027 break; 1028 } 1029 break; 1030 1031 case L2CAP_STATE_CLOSED: 1032 // @TODO handle incoming requests 1033 break; 1034 1035 case L2CAP_STATE_OPEN: 1036 //@TODO: implement other signaling packets, e.g. re-configure 1037 break; 1038 default: 1039 break; 1040 } 1041 // log_info("new state %u\n", channel->state); 1042 } 1043 1044 1045 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1046 1047 // get code, signalind identifier and command len 1048 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1049 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1050 1051 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1052 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1053 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1054 return; 1055 } 1056 1057 // general commands without an assigned channel 1058 switch(code) { 1059 1060 case CONNECTION_REQUEST: { 1061 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1062 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1063 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1064 return; 1065 } 1066 1067 case ECHO_REQUEST: 1068 l2cap_register_signaling_response(handle, code, sig_id, 0); 1069 return; 1070 1071 case INFORMATION_REQUEST: { 1072 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1073 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1074 return; 1075 } 1076 1077 default: 1078 break; 1079 } 1080 1081 1082 // Get potential destination CID 1083 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1084 1085 // Find channel for this sig_id and connection handle 1086 linked_item_t *it; 1087 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1088 l2cap_channel_t * channel = (l2cap_channel_t *) it; 1089 if (channel->handle == handle) { 1090 if (code & 1) { 1091 // match odd commands (responses) by previous signaling identifier 1092 if (channel->local_sig_id == sig_id) { 1093 l2cap_signaling_handler_channel(channel, command); 1094 break; 1095 } 1096 } else { 1097 // match even commands (requests) by local channel id 1098 if (channel->local_cid == dest_cid) { 1099 l2cap_signaling_handler_channel(channel, command); 1100 break; 1101 } 1102 } 1103 } 1104 } 1105 } 1106 1107 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 1108 1109 // Get Channel ID 1110 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1111 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1112 1113 switch (channel_id) { 1114 1115 case L2CAP_CID_SIGNALING: { 1116 1117 uint16_t command_offset = 8; 1118 while (command_offset < size) { 1119 1120 // handle signaling commands 1121 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1122 1123 // increment command_offset 1124 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1125 } 1126 break; 1127 } 1128 1129 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1130 if (attribute_protocol_packet_handler) { 1131 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1132 } 1133 break; 1134 1135 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1136 if (security_protocol_packet_handler) { 1137 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1138 } 1139 break; 1140 1141 default: { 1142 // Find channel for this channel_id and connection handle 1143 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1144 if (channel) { 1145 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1146 } 1147 break; 1148 } 1149 } 1150 1151 l2cap_run(); 1152 } 1153 1154 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1155 switch (packet_type) { 1156 case HCI_EVENT_PACKET: 1157 l2cap_event_handler(packet, size); 1158 break; 1159 case HCI_ACL_DATA_PACKET: 1160 l2cap_acl_handler(packet, size); 1161 break; 1162 default: 1163 break; 1164 } 1165 } 1166 1167 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1168 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1169 channel->state = L2CAP_STATE_CLOSED; 1170 l2cap_emit_channel_closed(channel); 1171 // discard channel 1172 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1173 btstack_memory_l2cap_channel_free(channel); 1174 } 1175 1176 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1177 linked_item_t *it; 1178 1179 // close open channels 1180 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 1181 l2cap_service_t * service = ((l2cap_service_t *) it); 1182 if ( service->psm == psm){ 1183 return service; 1184 }; 1185 } 1186 return NULL; 1187 } 1188 1189 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 1190 1191 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1192 1193 // check for alread registered psm 1194 // TODO: emit error event 1195 l2cap_service_t *service = l2cap_get_service(psm); 1196 if (service) { 1197 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 1198 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1199 return; 1200 } 1201 1202 // alloc structure 1203 // TODO: emit error event 1204 service = (l2cap_service_t *) btstack_memory_l2cap_service_get(); 1205 if (!service) { 1206 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 1207 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1208 return; 1209 } 1210 1211 // fill in 1212 service->psm = psm; 1213 service->mtu = mtu; 1214 service->connection = connection; 1215 service->packet_handler = packet_handler; 1216 1217 // add to services list 1218 linked_list_add(&l2cap_services, (linked_item_t *) service); 1219 1220 // enable page scan 1221 hci_connectable_control(1); 1222 1223 // done 1224 l2cap_emit_service_registered(connection, 0, psm); 1225 } 1226 1227 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1228 1229 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1230 1231 l2cap_service_t *service = l2cap_get_service(psm); 1232 if (!service) return; 1233 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1234 btstack_memory_l2cap_service_free(service); 1235 1236 // disable page scan when no services registered 1237 if (!linked_list_empty(&l2cap_services)) return; 1238 hci_connectable_control(0); 1239 } 1240 1241 // 1242 void l2cap_close_connection(void *connection){ 1243 linked_item_t *it; 1244 1245 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 1246 l2cap_channel_t * channel; 1247 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1248 channel = (l2cap_channel_t *) it; 1249 if (channel->connection == connection) { 1250 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1251 } 1252 } 1253 1254 // unregister services 1255 it = (linked_item_t *) &l2cap_services; 1256 while (it->next) { 1257 l2cap_service_t * service = (l2cap_service_t *) it->next; 1258 if (service->connection == connection){ 1259 it->next = it->next->next; 1260 btstack_memory_l2cap_service_free(service); 1261 } else { 1262 it = it->next; 1263 } 1264 } 1265 1266 // process 1267 l2cap_run(); 1268 } 1269 1270 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1271 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1272 switch(channel_id){ 1273 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1274 attribute_protocol_packet_handler = packet_handler; 1275 break; 1276 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1277 security_protocol_packet_handler = packet_handler; 1278 break; 1279 } 1280 } 1281 1282 #ifdef HAVE_BLE 1283 // Request LE connection parameter update 1284 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){ 1285 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 1286 log_info("l2cap_send_signaling_packet, cannot send\n"); 1287 return BTSTACK_ACL_BUFFERS_FULL; 1288 } 1289 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 1290 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 1291 uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); 1292 return hci_send_acl_packet(acl_buffer, len); 1293 } 1294 #endif 1295 1296