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_WAIT_CLIENT_ACCEPT_OR_REJECT: 497 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 498 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 499 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, 1, 0); 500 } 501 break; 502 503 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 504 // send connection request - set state first 505 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 506 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 507 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 508 break; 509 510 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 511 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, channel->reason, 0); 512 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 513 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); // -- remove from list 514 btstack_memory_l2cap_channel_free(channel); 515 break; 516 517 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 518 channel->state = L2CAP_STATE_CONFIG; 519 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 520 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 521 break; 522 523 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 524 // success, start l2cap handshake 525 channel->local_sig_id = l2cap_next_sig_id(); 526 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 527 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 528 l2cap_start_rtx(channel); 529 break; 530 531 case L2CAP_STATE_CONFIG: 532 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 533 uint16_t flags = 0; 534 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 535 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 536 flags = 1; 537 } else { 538 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 539 } 540 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 541 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 542 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 543 config_options[0] = 1; // MTU 544 config_options[1] = 2; // len param 545 bt_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 546 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 547 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 548 } else { 549 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 550 } 551 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 552 } 553 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 554 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 555 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 556 channel->local_sig_id = l2cap_next_sig_id(); 557 config_options[0] = 1; // MTU 558 config_options[1] = 2; // len param 559 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 560 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 561 l2cap_start_rtx(channel); 562 } 563 if (l2cap_channel_ready_for_open(channel)){ 564 channel->state = L2CAP_STATE_OPEN; 565 l2cap_emit_channel_opened(channel, 0); // success 566 l2cap_emit_credits(channel, 1); 567 } 568 break; 569 570 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 571 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 572 // 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 :) 573 l2cap_finialize_channel_close(channel); // -- remove from list 574 break; 575 576 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 577 channel->local_sig_id = l2cap_next_sig_id(); 578 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 579 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 580 break; 581 default: 582 break; 583 } 584 } 585 } 586 587 uint16_t l2cap_max_mtu(void){ 588 return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE; 589 } 590 591 // open outgoing L2CAP channel 592 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 593 bd_addr_t address, uint16_t psm, uint16_t mtu){ 594 595 log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 596 597 // alloc structure 598 l2cap_channel_t * chan = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 599 if (!chan) { 600 // emit error event 601 l2cap_channel_t dummy_channel; 602 BD_ADDR_COPY(dummy_channel.address, address); 603 dummy_channel.psm = psm; 604 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 605 return; 606 } 607 // limit local mtu to max acl packet length 608 if (mtu > l2cap_max_mtu()) { 609 mtu = l2cap_max_mtu(); 610 } 611 612 // fill in 613 BD_ADDR_COPY(chan->address, address); 614 chan->psm = psm; 615 chan->handle = 0; 616 chan->connection = connection; 617 chan->packet_handler = packet_handler; 618 chan->remote_mtu = L2CAP_MINIMAL_MTU; 619 chan->local_mtu = mtu; 620 chan->packets_granted = 0; 621 622 // set initial state 623 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 624 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 625 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 626 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 627 628 // add to connections list 629 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 630 631 l2cap_run(); 632 } 633 634 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 635 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 636 // find channel for local_cid 637 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 638 if (channel) { 639 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 640 } 641 // process 642 l2cap_run(); 643 } 644 645 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 646 linked_item_t *it = (linked_item_t *) &l2cap_channels; 647 while (it->next){ 648 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 649 if ( ! BD_ADDR_CMP( channel->address, address) ){ 650 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 651 // failure, forward error code 652 l2cap_emit_channel_opened(channel, status); 653 // discard channel 654 it->next = it->next->next; 655 btstack_memory_l2cap_channel_free(channel); 656 } 657 } else { 658 it = it->next; 659 } 660 } 661 } 662 663 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 664 linked_item_t *it; 665 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 666 l2cap_channel_t * channel = (l2cap_channel_t *) it; 667 if ( ! BD_ADDR_CMP( channel->address, address) ){ 668 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 669 // success, start l2cap handshake 670 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 671 channel->handle = handle; 672 channel->local_cid = l2cap_next_local_cid(); 673 } 674 } 675 } 676 // process 677 l2cap_run(); 678 } 679 680 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 681 682 bd_addr_t address; 683 hci_con_handle_t handle; 684 l2cap_channel_t * channel; 685 linked_item_t *it; 686 int hci_con_used; 687 688 switch(packet[0]){ 689 690 // handle connection complete events 691 case HCI_EVENT_CONNECTION_COMPLETE: 692 bt_flip_addr(address, &packet[5]); 693 if (packet[2] == 0){ 694 handle = READ_BT_16(packet, 3); 695 l2cap_handle_connection_success_for_addr(address, handle); 696 } else { 697 l2cap_handle_connection_failed_for_addr(address, packet[2]); 698 } 699 break; 700 701 // handle successful create connection cancel command 702 case HCI_EVENT_COMMAND_COMPLETE: 703 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 704 if (packet[5] == 0){ 705 bt_flip_addr(address, &packet[6]); 706 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 707 l2cap_handle_connection_failed_for_addr(address, 0x16); 708 } 709 } 710 l2cap_run(); // try sending signaling packets first 711 break; 712 713 case HCI_EVENT_COMMAND_STATUS: 714 l2cap_run(); // try sending signaling packets first 715 break; 716 717 // handle disconnection complete events 718 case HCI_EVENT_DISCONNECTION_COMPLETE: 719 // send l2cap disconnect events for all channels on this handle 720 handle = READ_BT_16(packet, 3); 721 it = (linked_item_t *) &l2cap_channels; 722 while (it->next){ 723 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 724 if ( channel->handle == handle ){ 725 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 726 it->next = it->next->next; 727 l2cap_emit_channel_closed(channel); 728 btstack_memory_l2cap_channel_free(channel); 729 } else { 730 it = it->next; 731 } 732 } 733 break; 734 735 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 736 l2cap_run(); // try sending signaling packets first 737 l2cap_hand_out_credits(); 738 break; 739 740 // HCI Connection Timeouts 741 case L2CAP_EVENT_TIMEOUT_CHECK: 742 handle = READ_BT_16(packet, 2); 743 if (hci_authentication_active_for_handle(handle)) break; 744 hci_con_used = 0; 745 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 746 channel = (l2cap_channel_t *) it; 747 if (channel->handle == handle) { 748 hci_con_used = 1; 749 } 750 } 751 if (hci_con_used) break; 752 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 753 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 754 break; 755 756 case DAEMON_EVENT_HCI_PACKET_SENT: 757 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 758 channel = (l2cap_channel_t *) it; 759 if (channel->packet_handler) { 760 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 761 } 762 } 763 if (attribute_protocol_packet_handler) { 764 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 765 } 766 if (security_protocol_packet_handler) { 767 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 768 } 769 break; 770 771 default: 772 break; 773 } 774 775 // pass on 776 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 777 } 778 779 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 780 channel->remote_sig_id = identifier; 781 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 782 l2cap_run(); 783 } 784 785 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 786 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 787 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 788 signaling_responses[signaling_responses_pending].handle = handle; 789 signaling_responses[signaling_responses_pending].code = code; 790 signaling_responses[signaling_responses_pending].sig_id = sig_id; 791 signaling_responses[signaling_responses_pending].data = data; 792 signaling_responses_pending++; 793 l2cap_run(); 794 } 795 } 796 797 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 798 799 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x\n", handle, psm, source_cid); 800 l2cap_service_t *service = l2cap_get_service(psm); 801 if (!service) { 802 // 0x0002 PSM not supported 803 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 804 return; 805 } 806 807 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 808 if (!hci_connection) { 809 // 810 log_error("no hci_connection for handle %u\n", handle); 811 return; 812 } 813 // alloc structure 814 // log_info("l2cap_handle_connection_request register channel\n"); 815 l2cap_channel_t * channel = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 816 if (!channel){ 817 // 0x0004 No resources available 818 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 819 return; 820 } 821 822 // fill in 823 BD_ADDR_COPY(channel->address, hci_connection->address); 824 channel->psm = psm; 825 channel->handle = handle; 826 channel->connection = service->connection; 827 channel->packet_handler = service->packet_handler; 828 channel->local_cid = l2cap_next_local_cid(); 829 channel->remote_cid = source_cid; 830 channel->local_mtu = service->mtu; 831 channel->remote_mtu = L2CAP_DEFAULT_MTU; 832 channel->packets_granted = 0; 833 channel->remote_sig_id = sig_id; 834 835 // limit local mtu to max acl packet length 836 if (channel->local_mtu > l2cap_max_mtu()) { 837 channel->local_mtu = l2cap_max_mtu(); 838 } 839 840 // set initial state 841 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 842 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 843 844 // add to connections list 845 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 846 847 // 848 // gap_security_level_t current_level = gap_security_level(handle); 849 // gap_security_level_t required_level = LEVEL_2; 850 // if (current_level < required_level){ 851 // gap_request_security_level(handle, required_level); 852 // return; 853 // } 854 855 // emit incoming connection request 856 l2cap_emit_connection_request(channel); 857 } 858 859 void l2cap_accept_connection_internal(uint16_t local_cid){ 860 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 861 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 862 if (!channel) { 863 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 864 return; 865 } 866 867 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 868 869 // process 870 l2cap_run(); 871 } 872 873 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 874 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); 875 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 876 if (!channel) { 877 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 878 return; 879 } 880 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 881 channel->reason = reason; 882 l2cap_run(); 883 } 884 885 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 886 887 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 888 889 uint16_t flags = READ_BT_16(command, 6); 890 if (flags & 1) { 891 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 892 } 893 894 // accept the other's configuration options 895 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 896 uint16_t pos = 8; 897 while (pos < end_pos){ 898 uint8_t option_hint = command[pos] >> 7; 899 uint8_t option_type = command[pos] & 0x7f; 900 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 901 pos++; 902 uint8_t length = command[pos++]; 903 // MTU { type(8): 1, len(8):2, MTU(16) } 904 if (option_type == 1 && length == 2){ 905 channel->remote_mtu = READ_BT_16(command, pos); 906 // log_info("l2cap cid 0x%02x, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 907 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 908 } 909 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 910 if (option_type == 2 && length == 2){ 911 channel->flush_timeout = READ_BT_16(command, pos); 912 } 913 // check for unknown options 914 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 915 log_info("l2cap cid %u, unknown options", channel->local_cid); 916 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 917 } 918 pos += length; 919 } 920 } 921 922 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 923 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 924 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 925 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 926 return 1; 927 } 928 929 930 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 931 932 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 933 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 934 uint16_t result = 0; 935 936 log_info("L2CAP signaling handler code %u, state %u\n", code, channel->state); 937 938 // handle DISCONNECT REQUESTS seperately 939 if (code == DISCONNECTION_REQUEST){ 940 switch (channel->state){ 941 case L2CAP_STATE_CONFIG: 942 case L2CAP_STATE_OPEN: 943 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 944 case L2CAP_STATE_WAIT_DISCONNECT: 945 l2cap_handle_disconnect_request(channel, identifier); 946 break; 947 948 default: 949 // ignore in other states 950 break; 951 } 952 return; 953 } 954 955 // @STATEMACHINE(l2cap) 956 switch (channel->state) { 957 958 case L2CAP_STATE_WAIT_CONNECT_RSP: 959 switch (code){ 960 case CONNECTION_RESPONSE: 961 l2cap_stop_rtx(channel); 962 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 963 switch (result) { 964 case 0: 965 // successful connection 966 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 967 channel->state = L2CAP_STATE_CONFIG; 968 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 969 break; 970 case 1: 971 // connection pending. get some coffee, but start the ERTX 972 l2cap_start_ertx(channel); 973 break; 974 default: 975 // channel closed 976 channel->state = L2CAP_STATE_CLOSED; 977 // map l2cap connection response result to BTstack status enumeration 978 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 979 980 // drop link key if security block 981 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 982 hci_drop_link_key_for_bd_addr(&channel->address); 983 } 984 985 // discard channel 986 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 987 btstack_memory_l2cap_channel_free(channel); 988 break; 989 } 990 break; 991 992 default: 993 //@TODO: implement other signaling packets 994 break; 995 } 996 break; 997 998 case L2CAP_STATE_CONFIG: 999 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1000 switch (code) { 1001 case CONFIGURE_REQUEST: 1002 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1003 l2cap_signaling_handle_configure_request(channel, command); 1004 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1005 // only done if continuation not set 1006 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1007 } 1008 break; 1009 case CONFIGURE_RESPONSE: 1010 l2cap_stop_rtx(channel); 1011 switch (result){ 1012 case 0: // success 1013 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1014 break; 1015 case 4: // pending 1016 l2cap_start_ertx(channel); 1017 break; 1018 default: 1019 // retry on negative result 1020 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1021 break; 1022 } 1023 break; 1024 default: 1025 break; 1026 } 1027 if (l2cap_channel_ready_for_open(channel)){ 1028 // for open: 1029 channel->state = L2CAP_STATE_OPEN; 1030 l2cap_emit_channel_opened(channel, 0); 1031 l2cap_emit_credits(channel, 1); 1032 } 1033 break; 1034 1035 case L2CAP_STATE_WAIT_DISCONNECT: 1036 switch (code) { 1037 case DISCONNECTION_RESPONSE: 1038 l2cap_finialize_channel_close(channel); 1039 break; 1040 default: 1041 //@TODO: implement other signaling packets 1042 break; 1043 } 1044 break; 1045 1046 case L2CAP_STATE_CLOSED: 1047 // @TODO handle incoming requests 1048 break; 1049 1050 case L2CAP_STATE_OPEN: 1051 //@TODO: implement other signaling packets, e.g. re-configure 1052 break; 1053 default: 1054 break; 1055 } 1056 // log_info("new state %u\n", channel->state); 1057 } 1058 1059 1060 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1061 1062 // get code, signalind identifier and command len 1063 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1064 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1065 1066 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1067 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1068 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1069 return; 1070 } 1071 1072 // general commands without an assigned channel 1073 switch(code) { 1074 1075 case CONNECTION_REQUEST: { 1076 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1077 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1078 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1079 return; 1080 } 1081 1082 case ECHO_REQUEST: 1083 l2cap_register_signaling_response(handle, code, sig_id, 0); 1084 return; 1085 1086 case INFORMATION_REQUEST: { 1087 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1088 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1089 return; 1090 } 1091 1092 default: 1093 break; 1094 } 1095 1096 1097 // Get potential destination CID 1098 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1099 1100 // Find channel for this sig_id and connection handle 1101 linked_item_t *it; 1102 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1103 l2cap_channel_t * channel = (l2cap_channel_t *) it; 1104 if (channel->handle == handle) { 1105 if (code & 1) { 1106 // match odd commands (responses) by previous signaling identifier 1107 if (channel->local_sig_id == sig_id) { 1108 l2cap_signaling_handler_channel(channel, command); 1109 break; 1110 } 1111 } else { 1112 // match even commands (requests) by local channel id 1113 if (channel->local_cid == dest_cid) { 1114 l2cap_signaling_handler_channel(channel, command); 1115 break; 1116 } 1117 } 1118 } 1119 } 1120 } 1121 1122 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 1123 1124 // Get Channel ID 1125 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1126 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1127 1128 switch (channel_id) { 1129 1130 case L2CAP_CID_SIGNALING: { 1131 1132 uint16_t command_offset = 8; 1133 while (command_offset < size) { 1134 1135 // handle signaling commands 1136 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1137 1138 // increment command_offset 1139 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1140 } 1141 break; 1142 } 1143 1144 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1145 if (attribute_protocol_packet_handler) { 1146 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1147 } 1148 break; 1149 1150 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1151 if (security_protocol_packet_handler) { 1152 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1153 } 1154 break; 1155 1156 default: { 1157 // Find channel for this channel_id and connection handle 1158 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1159 if (channel) { 1160 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1161 } 1162 break; 1163 } 1164 } 1165 1166 l2cap_run(); 1167 } 1168 1169 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1170 switch (packet_type) { 1171 case HCI_EVENT_PACKET: 1172 l2cap_event_handler(packet, size); 1173 break; 1174 case HCI_ACL_DATA_PACKET: 1175 l2cap_acl_handler(packet, size); 1176 break; 1177 default: 1178 break; 1179 } 1180 } 1181 1182 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1183 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1184 channel->state = L2CAP_STATE_CLOSED; 1185 l2cap_emit_channel_closed(channel); 1186 // discard channel 1187 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1188 btstack_memory_l2cap_channel_free(channel); 1189 } 1190 1191 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1192 linked_item_t *it; 1193 1194 // close open channels 1195 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 1196 l2cap_service_t * service = ((l2cap_service_t *) it); 1197 if ( service->psm == psm){ 1198 return service; 1199 }; 1200 } 1201 return NULL; 1202 } 1203 1204 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 1205 1206 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1207 1208 // check for alread registered psm 1209 // TODO: emit error event 1210 l2cap_service_t *service = l2cap_get_service(psm); 1211 if (service) { 1212 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 1213 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1214 return; 1215 } 1216 1217 // alloc structure 1218 // TODO: emit error event 1219 service = (l2cap_service_t *) btstack_memory_l2cap_service_get(); 1220 if (!service) { 1221 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 1222 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1223 return; 1224 } 1225 1226 // fill in 1227 service->psm = psm; 1228 service->mtu = mtu; 1229 service->connection = connection; 1230 service->packet_handler = packet_handler; 1231 1232 // add to services list 1233 linked_list_add(&l2cap_services, (linked_item_t *) service); 1234 1235 // enable page scan 1236 hci_connectable_control(1); 1237 1238 // done 1239 l2cap_emit_service_registered(connection, 0, psm); 1240 } 1241 1242 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1243 1244 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1245 1246 l2cap_service_t *service = l2cap_get_service(psm); 1247 if (!service) return; 1248 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1249 btstack_memory_l2cap_service_free(service); 1250 1251 // disable page scan when no services registered 1252 if (!linked_list_empty(&l2cap_services)) return; 1253 hci_connectable_control(0); 1254 } 1255 1256 // 1257 void l2cap_close_connection(void *connection){ 1258 linked_item_t *it; 1259 1260 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 1261 l2cap_channel_t * channel; 1262 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1263 channel = (l2cap_channel_t *) it; 1264 if (channel->connection == connection) { 1265 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1266 } 1267 } 1268 1269 // unregister services 1270 it = (linked_item_t *) &l2cap_services; 1271 while (it->next) { 1272 l2cap_service_t * service = (l2cap_service_t *) it->next; 1273 if (service->connection == connection){ 1274 it->next = it->next->next; 1275 btstack_memory_l2cap_service_free(service); 1276 } else { 1277 it = it->next; 1278 } 1279 } 1280 1281 // process 1282 l2cap_run(); 1283 } 1284 1285 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1286 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1287 switch(channel_id){ 1288 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1289 attribute_protocol_packet_handler = packet_handler; 1290 break; 1291 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1292 security_protocol_packet_handler = packet_handler; 1293 break; 1294 } 1295 } 1296 1297 #ifdef HAVE_BLE 1298 // Request LE connection parameter update 1299 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){ 1300 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 1301 log_info("l2cap_send_signaling_packet, cannot send\n"); 1302 return BTSTACK_ACL_BUFFERS_FULL; 1303 } 1304 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 1305 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 1306 uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); 1307 return hci_send_acl_packet(acl_buffer, len); 1308 } 1309 #endif 1310 1311