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", 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); 129 uint8_t event[21]; 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 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 141 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 142 } 143 144 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 145 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 146 uint8_t event[4]; 147 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 148 event[1] = sizeof(event) - 2; 149 bt_store_16(event, 2, channel->local_cid); 150 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 151 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 152 } 153 154 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 155 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 156 bd_addr_to_str(channel->address), channel->handle, channel->psm, channel->local_cid, channel->remote_cid); 157 uint8_t event[16]; 158 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 159 event[1] = sizeof(event) - 2; 160 bt_flip_addr(&event[2], channel->address); 161 bt_store_16(event, 8, channel->handle); 162 bt_store_16(event, 10, channel->psm); 163 bt_store_16(event, 12, channel->local_cid); 164 bt_store_16(event, 14, channel->remote_cid); 165 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 166 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 167 } 168 169 static void l2cap_emit_service_registered(void *connection, uint8_t status, uint16_t psm){ 170 log_info("L2CAP_EVENT_SERVICE_REGISTERED status 0x%x psm 0x%x", status, psm); 171 uint8_t event[5]; 172 event[0] = L2CAP_EVENT_SERVICE_REGISTERED; 173 event[1] = sizeof(event) - 2; 174 event[2] = status; 175 bt_store_16(event, 3, psm); 176 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 177 (*packet_handler)(connection, HCI_EVENT_PACKET, 0, event, sizeof(event)); 178 } 179 180 void l2cap_emit_credits(l2cap_channel_t *channel, uint8_t credits) { 181 182 log_info("L2CAP_EVENT_CREDITS local_cid 0x%x credits %u", channel->local_cid, credits); 183 // track credits 184 channel->packets_granted += credits; 185 186 uint8_t event[5]; 187 event[0] = L2CAP_EVENT_CREDITS; 188 event[1] = sizeof(event) - 2; 189 bt_store_16(event, 2, channel->local_cid); 190 event[4] = credits; 191 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 192 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 193 } 194 195 void l2cap_block_new_credits(uint8_t blocked){ 196 new_credits_blocked = blocked; 197 } 198 199 void l2cap_hand_out_credits(void){ 200 201 if (new_credits_blocked) return; // we're told not to. used by daemon 202 203 linked_item_t *it; 204 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 205 if (!hci_number_free_acl_slots()) return; 206 l2cap_channel_t * channel = (l2cap_channel_t *) it; 207 if (channel->state != L2CAP_STATE_OPEN) continue; 208 if (hci_number_outgoing_packets(channel->handle) < NR_BUFFERED_ACL_PACKETS && channel->packets_granted == 0) { 209 l2cap_emit_credits(channel, 1); 210 } 211 } 212 } 213 214 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 215 linked_item_t *it; 216 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 217 l2cap_channel_t * channel = (l2cap_channel_t *) it; 218 if ( channel->local_cid == local_cid) { 219 return channel; 220 } 221 } 222 return NULL; 223 } 224 225 int l2cap_can_send_packet_now(uint16_t local_cid){ 226 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 227 if (!channel) return 0; 228 if (!channel->packets_granted) return 0; 229 return hci_can_send_packet_now(HCI_ACL_DATA_PACKET); 230 } 231 232 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 233 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 234 if (channel) { 235 return channel->remote_mtu; 236 } 237 return 0; 238 } 239 240 static l2cap_channel_t * l2cap_channel_for_rtx_timer(timer_source_t * ts){ 241 linked_item_t *it; 242 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 243 l2cap_channel_t * channel = (l2cap_channel_t *) it; 244 if ( &channel->rtx == ts) { 245 return channel; 246 } 247 } 248 return NULL; 249 } 250 251 static void l2cap_rtx_timeout(timer_source_t * ts){ 252 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 253 if (!ts) return; 254 255 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 256 257 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 258 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 259 // notify client 260 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 261 262 // discard channel 263 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 264 btstack_memory_l2cap_channel_free(channel); 265 } 266 267 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 268 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 269 run_loop_remove_timer(&channel->rtx); 270 } 271 272 static void l2cap_start_rtx(l2cap_channel_t * channel){ 273 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 274 l2cap_stop_rtx(channel); 275 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 276 run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 277 run_loop_add_timer(&channel->rtx); 278 } 279 280 static void l2cap_start_ertx(l2cap_channel_t * channel){ 281 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 282 l2cap_stop_rtx(channel); 283 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 284 run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 285 run_loop_add_timer(&channel->rtx); 286 } 287 288 289 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 290 291 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 292 log_info("l2cap_send_signaling_packet, cannot send\n"); 293 return BTSTACK_ACL_BUFFERS_FULL; 294 } 295 296 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 297 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 298 va_list argptr; 299 va_start(argptr, identifier); 300 uint16_t len = l2cap_create_signaling_internal(acl_buffer, handle, cmd, identifier, argptr); 301 va_end(argptr); 302 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 303 return hci_send_acl_packet(acl_buffer, len); 304 } 305 306 uint8_t *l2cap_get_outgoing_buffer(void){ 307 return hci_get_outgoing_acl_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 308 } 309 310 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 311 312 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 313 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", local_cid); 314 return BTSTACK_ACL_BUFFERS_FULL; 315 } 316 317 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 318 if (!channel) { 319 log_error("l2cap_send_internal no channel for cid 0x%02x\n", local_cid); 320 return -1; // TODO: define error 321 } 322 323 if (channel->packets_granted == 0){ 324 log_error("l2cap_send_internal cid 0x%02x, no credits!\n", local_cid); 325 return -1; // TODO: define error 326 } 327 328 --channel->packets_granted; 329 330 log_debug("l2cap_send_internal cid 0x%02x, handle %u, 1 credit used, credits left %u;\n", 331 local_cid, channel->handle, channel->packets_granted); 332 333 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 334 335 // 0 - Connection handle : PB=10 : BC=00 336 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 337 // 2 - ACL length 338 bt_store_16(acl_buffer, 2, len + 4); 339 // 4 - L2CAP packet length 340 bt_store_16(acl_buffer, 4, len + 0); 341 // 6 - L2CAP channel DEST 342 bt_store_16(acl_buffer, 6, channel->remote_cid); 343 // send 344 int err = hci_send_acl_packet(acl_buffer, len+8); 345 346 l2cap_hand_out_credits(); 347 348 return err; 349 } 350 351 int l2cap_send_prepared_connectionless(uint16_t handle, uint16_t cid, uint16_t len){ 352 353 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 354 log_info("l2cap_send_prepared_to_handle cid 0x%02x, cannot send\n", cid); 355 return BTSTACK_ACL_BUFFERS_FULL; 356 } 357 358 log_debug("l2cap_send_prepared_to_handle cid 0x%02x, handle %u\n", cid, handle); 359 360 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 361 362 // 0 - Connection handle : PB=10 : BC=00 363 bt_store_16(acl_buffer, 0, handle | (2 << 12) | (0 << 14)); 364 // 2 - ACL length 365 bt_store_16(acl_buffer, 2, len + 4); 366 // 4 - L2CAP packet length 367 bt_store_16(acl_buffer, 4, len + 0); 368 // 6 - L2CAP channel DEST 369 bt_store_16(acl_buffer, 6, cid); 370 // send 371 int err = hci_send_acl_packet(acl_buffer, len+8); 372 373 l2cap_hand_out_credits(); 374 375 return err; 376 } 377 378 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 379 380 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 381 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", local_cid); 382 return BTSTACK_ACL_BUFFERS_FULL; 383 } 384 385 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 386 387 memcpy(&acl_buffer[8], data, len); 388 389 return l2cap_send_prepared(local_cid, len); 390 } 391 392 int l2cap_send_connectionless(uint16_t handle, uint16_t cid, uint8_t *data, uint16_t len){ 393 394 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 395 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", cid); 396 return BTSTACK_ACL_BUFFERS_FULL; 397 } 398 399 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 400 401 memcpy(&acl_buffer[8], data, len); 402 403 return l2cap_send_prepared_connectionless(handle, cid, len); 404 } 405 406 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 407 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 408 } 409 410 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 411 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 412 } 413 414 415 416 // MARK: L2CAP_RUN 417 // process outstanding signaling tasks 418 void l2cap_run(void){ 419 420 // check pending signaling responses 421 while (signaling_responses_pending){ 422 423 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)) break; 424 425 hci_con_handle_t handle = signaling_responses[0].handle; 426 uint8_t sig_id = signaling_responses[0].sig_id; 427 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 428 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 429 430 switch (signaling_responses[0].code){ 431 case CONNECTION_REQUEST: 432 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 433 break; 434 case ECHO_REQUEST: 435 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 436 break; 437 case INFORMATION_REQUEST: 438 switch (infoType){ 439 case 1: { // Connectionless MTU 440 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 441 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 442 break; 443 } 444 case 2: { // Extended Features Supported 445 // extended features request supported, only supporing fixed channel map 446 uint32_t features = 0x80; 447 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 448 break; 449 } 450 case 3: { // Fixed Channels Supported 451 uint8_t map[8]; 452 memset(map, 0, 8); 453 map[0] = 0x01; // L2CAP Signaling Channel 454 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 455 break; 456 } 457 default: 458 // all other types are not supported 459 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 460 break; 461 } 462 break; 463 case COMMAND_REJECT: 464 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result); 465 break; 466 default: 467 // should not happen 468 break; 469 } 470 471 // remove first item 472 signaling_responses_pending--; 473 int i; 474 for (i=0; i < signaling_responses_pending; i++){ 475 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 476 } 477 } 478 479 uint8_t config_options[4]; 480 linked_item_t *it; 481 linked_item_t *next; 482 for (it = (linked_item_t *) l2cap_channels; it ; it = next){ 483 next = it->next; // cache next item as current item might get freed 484 485 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 486 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)) break; 487 488 l2cap_channel_t * channel = (l2cap_channel_t *) it; 489 490 // log_info("l2cap_run: state %u, var 0x%02x\n", channel->state, channel->state_var); 491 492 493 switch (channel->state){ 494 495 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 496 // send connection request - set state first 497 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 498 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 499 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 500 break; 501 502 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 503 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, channel->reason, 0); 504 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 505 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); // -- remove from list 506 btstack_memory_l2cap_channel_free(channel); 507 break; 508 509 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 510 channel->state = L2CAP_STATE_CONFIG; 511 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 512 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 513 break; 514 515 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 516 // success, start l2cap handshake 517 channel->local_sig_id = l2cap_next_sig_id(); 518 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 519 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 520 l2cap_start_rtx(channel); 521 break; 522 523 case L2CAP_STATE_CONFIG: 524 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 525 uint16_t flags = 0; 526 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 527 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 528 flags = 1; 529 } else { 530 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 531 } 532 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 533 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 534 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 535 config_options[0] = 1; // MTU 536 config_options[1] = 2; // len param 537 bt_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 538 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 539 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 540 } else { 541 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 542 } 543 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 544 } 545 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 546 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 547 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 548 channel->local_sig_id = l2cap_next_sig_id(); 549 config_options[0] = 1; // MTU 550 config_options[1] = 2; // len param 551 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 552 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 553 l2cap_start_rtx(channel); 554 } 555 if (l2cap_channel_ready_for_open(channel)){ 556 channel->state = L2CAP_STATE_OPEN; 557 l2cap_emit_channel_opened(channel, 0); // success 558 l2cap_emit_credits(channel, 1); 559 } 560 break; 561 562 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 563 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 564 // 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 :) 565 l2cap_finialize_channel_close(channel); // -- remove from list 566 break; 567 568 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 569 channel->local_sig_id = l2cap_next_sig_id(); 570 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 571 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 572 break; 573 default: 574 break; 575 } 576 } 577 } 578 579 uint16_t l2cap_max_mtu(void){ 580 return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE; 581 } 582 583 // open outgoing L2CAP channel 584 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 585 bd_addr_t address, uint16_t psm, uint16_t mtu){ 586 587 log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 588 589 // alloc structure 590 l2cap_channel_t * chan = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 591 if (!chan) { 592 // emit error event 593 l2cap_channel_t dummy_channel; 594 BD_ADDR_COPY(dummy_channel.address, address); 595 dummy_channel.psm = psm; 596 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 597 return; 598 } 599 // limit local mtu to max acl packet length 600 if (mtu > l2cap_max_mtu()) { 601 mtu = l2cap_max_mtu(); 602 } 603 604 // fill in 605 BD_ADDR_COPY(chan->address, address); 606 chan->psm = psm; 607 chan->handle = 0; 608 chan->connection = connection; 609 chan->packet_handler = packet_handler; 610 chan->remote_mtu = L2CAP_MINIMAL_MTU; 611 chan->local_mtu = mtu; 612 chan->packets_granted = 0; 613 614 // set initial state 615 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 616 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 617 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 618 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 619 620 // add to connections list 621 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 622 623 l2cap_run(); 624 } 625 626 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 627 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 628 // find channel for local_cid 629 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 630 if (channel) { 631 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 632 } 633 // process 634 l2cap_run(); 635 } 636 637 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 638 linked_item_t *it = (linked_item_t *) &l2cap_channels; 639 while (it->next){ 640 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 641 if ( ! BD_ADDR_CMP( channel->address, address) ){ 642 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 643 // failure, forward error code 644 l2cap_emit_channel_opened(channel, status); 645 // discard channel 646 it->next = it->next->next; 647 btstack_memory_l2cap_channel_free(channel); 648 } 649 } else { 650 it = it->next; 651 } 652 } 653 } 654 655 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 656 linked_item_t *it; 657 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 658 l2cap_channel_t * channel = (l2cap_channel_t *) it; 659 if ( ! BD_ADDR_CMP( channel->address, address) ){ 660 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 661 // success, start l2cap handshake 662 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 663 channel->handle = handle; 664 channel->local_cid = l2cap_next_local_cid(); 665 } 666 } 667 } 668 // process 669 l2cap_run(); 670 } 671 672 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 673 674 bd_addr_t address; 675 hci_con_handle_t handle; 676 l2cap_channel_t * channel; 677 linked_item_t *it; 678 int hci_con_used; 679 680 switch(packet[0]){ 681 682 // handle connection complete events 683 case HCI_EVENT_CONNECTION_COMPLETE: 684 bt_flip_addr(address, &packet[5]); 685 if (packet[2] == 0){ 686 handle = READ_BT_16(packet, 3); 687 l2cap_handle_connection_success_for_addr(address, handle); 688 } else { 689 l2cap_handle_connection_failed_for_addr(address, packet[2]); 690 } 691 break; 692 693 // handle successful create connection cancel command 694 case HCI_EVENT_COMMAND_COMPLETE: 695 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 696 if (packet[5] == 0){ 697 bt_flip_addr(address, &packet[6]); 698 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 699 l2cap_handle_connection_failed_for_addr(address, 0x16); 700 } 701 } 702 l2cap_run(); // try sending signaling packets first 703 break; 704 705 case HCI_EVENT_COMMAND_STATUS: 706 l2cap_run(); // try sending signaling packets first 707 break; 708 709 // handle disconnection complete events 710 case HCI_EVENT_DISCONNECTION_COMPLETE: 711 // send l2cap disconnect events for all channels on this handle 712 handle = READ_BT_16(packet, 3); 713 it = (linked_item_t *) &l2cap_channels; 714 while (it->next){ 715 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 716 if ( channel->handle == handle ){ 717 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 718 it->next = it->next->next; 719 l2cap_emit_channel_closed(channel); 720 btstack_memory_l2cap_channel_free(channel); 721 } else { 722 it = it->next; 723 } 724 } 725 break; 726 727 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 728 l2cap_run(); // try sending signaling packets first 729 l2cap_hand_out_credits(); 730 break; 731 732 // HCI Connection Timeouts 733 case L2CAP_EVENT_TIMEOUT_CHECK: 734 handle = READ_BT_16(packet, 2); 735 if (hci_authentication_active_for_handle(handle)) break; 736 hci_con_used = 0; 737 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 738 channel = (l2cap_channel_t *) it; 739 if (channel->handle == handle) { 740 hci_con_used = 1; 741 } 742 } 743 if (hci_con_used) break; 744 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 745 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 746 break; 747 748 case DAEMON_EVENT_HCI_PACKET_SENT: 749 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 750 channel = (l2cap_channel_t *) it; 751 if (channel->packet_handler) { 752 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 753 } 754 } 755 if (attribute_protocol_packet_handler) { 756 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 757 } 758 if (security_protocol_packet_handler) { 759 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 760 } 761 break; 762 763 default: 764 break; 765 } 766 767 // pass on 768 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 769 } 770 771 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 772 channel->remote_sig_id = identifier; 773 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 774 l2cap_run(); 775 } 776 777 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 778 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 779 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 780 signaling_responses[signaling_responses_pending].handle = handle; 781 signaling_responses[signaling_responses_pending].code = code; 782 signaling_responses[signaling_responses_pending].sig_id = sig_id; 783 signaling_responses[signaling_responses_pending].data = data; 784 signaling_responses_pending++; 785 l2cap_run(); 786 } 787 } 788 789 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 790 791 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x\n", handle, psm, source_cid); 792 l2cap_service_t *service = l2cap_get_service(psm); 793 if (!service) { 794 // 0x0002 PSM not supported 795 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 796 return; 797 } 798 799 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 800 if (!hci_connection) { 801 // 802 log_error("no hci_connection for handle %u\n", handle); 803 return; 804 } 805 // alloc structure 806 // log_info("l2cap_handle_connection_request register channel\n"); 807 l2cap_channel_t * channel = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 808 if (!channel){ 809 // 0x0004 No resources available 810 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 811 return; 812 } 813 814 // fill in 815 BD_ADDR_COPY(channel->address, hci_connection->address); 816 channel->psm = psm; 817 channel->handle = handle; 818 channel->connection = service->connection; 819 channel->packet_handler = service->packet_handler; 820 channel->local_cid = l2cap_next_local_cid(); 821 channel->remote_cid = source_cid; 822 channel->local_mtu = service->mtu; 823 channel->remote_mtu = L2CAP_DEFAULT_MTU; 824 channel->packets_granted = 0; 825 channel->remote_sig_id = sig_id; 826 827 // limit local mtu to max acl packet length 828 if (channel->local_mtu > l2cap_max_mtu()) { 829 channel->local_mtu = l2cap_max_mtu(); 830 } 831 832 // set initial state 833 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 834 channel->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 835 836 // add to connections list 837 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 838 839 // emit incoming connection request 840 l2cap_emit_connection_request(channel); 841 } 842 843 void l2cap_accept_connection_internal(uint16_t local_cid){ 844 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 845 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 846 if (!channel) { 847 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 848 return; 849 } 850 851 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 852 853 // process 854 l2cap_run(); 855 } 856 857 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 858 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); 859 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 860 if (!channel) { 861 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 862 return; 863 } 864 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 865 channel->reason = reason; 866 l2cap_run(); 867 } 868 869 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 870 871 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 872 873 uint16_t flags = READ_BT_16(command, 6); 874 if (flags & 1) { 875 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 876 } 877 878 // accept the other's configuration options 879 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 880 uint16_t pos = 8; 881 while (pos < end_pos){ 882 uint8_t option_hint = command[pos] >> 7; 883 uint8_t option_type = command[pos] & 0x7f; 884 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 885 pos++; 886 uint8_t length = command[pos++]; 887 // MTU { type(8): 1, len(8):2, MTU(16) } 888 if (option_type == 1 && length == 2){ 889 channel->remote_mtu = READ_BT_16(command, pos); 890 // log_info("l2cap cid 0x%02x, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 891 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 892 } 893 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 894 if (option_type == 2 && length == 2){ 895 channel->flush_timeout = READ_BT_16(command, pos); 896 } 897 // check for unknown options 898 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 899 log_info("l2cap cid %u, unknown options", channel->local_cid); 900 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 901 } 902 pos += length; 903 } 904 } 905 906 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 907 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 908 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 909 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 910 return 1; 911 } 912 913 914 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 915 916 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 917 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 918 uint16_t result = 0; 919 920 log_info("L2CAP signaling handler code %u, state %u\n", code, channel->state); 921 922 // handle DISCONNECT REQUESTS seperately 923 if (code == DISCONNECTION_REQUEST){ 924 switch (channel->state){ 925 case L2CAP_STATE_CONFIG: 926 case L2CAP_STATE_OPEN: 927 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 928 case L2CAP_STATE_WAIT_DISCONNECT: 929 l2cap_handle_disconnect_request(channel, identifier); 930 break; 931 932 default: 933 // ignore in other states 934 break; 935 } 936 return; 937 } 938 939 // @STATEMACHINE(l2cap) 940 switch (channel->state) { 941 942 case L2CAP_STATE_WAIT_CONNECT_RSP: 943 switch (code){ 944 case CONNECTION_RESPONSE: 945 l2cap_stop_rtx(channel); 946 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 947 switch (result) { 948 case 0: 949 // successful connection 950 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 951 channel->state = L2CAP_STATE_CONFIG; 952 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 953 break; 954 case 1: 955 // connection pending. get some coffee, but start the ERTX 956 l2cap_start_ertx(channel); 957 break; 958 default: 959 // channel closed 960 channel->state = L2CAP_STATE_CLOSED; 961 // map l2cap connection response result to BTstack status enumeration 962 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 963 964 // drop link key if security block 965 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 966 hci_drop_link_key_for_bd_addr(&channel->address); 967 } 968 969 // discard channel 970 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 971 btstack_memory_l2cap_channel_free(channel); 972 break; 973 } 974 break; 975 976 default: 977 //@TODO: implement other signaling packets 978 break; 979 } 980 break; 981 982 case L2CAP_STATE_CONFIG: 983 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 984 switch (code) { 985 case CONFIGURE_REQUEST: 986 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 987 l2cap_signaling_handle_configure_request(channel, command); 988 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 989 // only done if continuation not set 990 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 991 } 992 break; 993 case CONFIGURE_RESPONSE: 994 l2cap_stop_rtx(channel); 995 switch (result){ 996 case 0: // success 997 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 998 break; 999 case 4: // pending 1000 l2cap_start_ertx(channel); 1001 break; 1002 default: 1003 // retry on negative result 1004 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1005 break; 1006 } 1007 break; 1008 default: 1009 break; 1010 } 1011 if (l2cap_channel_ready_for_open(channel)){ 1012 // for open: 1013 channel->state = L2CAP_STATE_OPEN; 1014 l2cap_emit_channel_opened(channel, 0); 1015 l2cap_emit_credits(channel, 1); 1016 } 1017 break; 1018 1019 case L2CAP_STATE_WAIT_DISCONNECT: 1020 switch (code) { 1021 case DISCONNECTION_RESPONSE: 1022 l2cap_finialize_channel_close(channel); 1023 break; 1024 default: 1025 //@TODO: implement other signaling packets 1026 break; 1027 } 1028 break; 1029 1030 case L2CAP_STATE_CLOSED: 1031 // @TODO handle incoming requests 1032 break; 1033 1034 case L2CAP_STATE_OPEN: 1035 //@TODO: implement other signaling packets, e.g. re-configure 1036 break; 1037 default: 1038 break; 1039 } 1040 // log_info("new state %u\n", channel->state); 1041 } 1042 1043 1044 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1045 1046 // get code, signalind identifier and command len 1047 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1048 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1049 1050 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1051 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1052 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1053 return; 1054 } 1055 1056 // general commands without an assigned channel 1057 switch(code) { 1058 1059 case CONNECTION_REQUEST: { 1060 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1061 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1062 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1063 return; 1064 } 1065 1066 case ECHO_REQUEST: 1067 l2cap_register_signaling_response(handle, code, sig_id, 0); 1068 return; 1069 1070 case INFORMATION_REQUEST: { 1071 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1072 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1073 return; 1074 } 1075 1076 default: 1077 break; 1078 } 1079 1080 1081 // Get potential destination CID 1082 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1083 1084 // Find channel for this sig_id and connection handle 1085 linked_item_t *it; 1086 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1087 l2cap_channel_t * channel = (l2cap_channel_t *) it; 1088 if (channel->handle == handle) { 1089 if (code & 1) { 1090 // match odd commands (responses) by previous signaling identifier 1091 if (channel->local_sig_id == sig_id) { 1092 l2cap_signaling_handler_channel(channel, command); 1093 break; 1094 } 1095 } else { 1096 // match even commands (requests) by local channel id 1097 if (channel->local_cid == dest_cid) { 1098 l2cap_signaling_handler_channel(channel, command); 1099 break; 1100 } 1101 } 1102 } 1103 } 1104 } 1105 1106 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 1107 1108 // Get Channel ID 1109 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1110 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1111 1112 switch (channel_id) { 1113 1114 case L2CAP_CID_SIGNALING: { 1115 1116 uint16_t command_offset = 8; 1117 while (command_offset < size) { 1118 1119 // handle signaling commands 1120 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1121 1122 // increment command_offset 1123 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1124 } 1125 break; 1126 } 1127 1128 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1129 if (attribute_protocol_packet_handler) { 1130 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1131 } 1132 break; 1133 1134 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1135 if (security_protocol_packet_handler) { 1136 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1137 } 1138 break; 1139 1140 default: { 1141 // Find channel for this channel_id and connection handle 1142 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1143 if (channel) { 1144 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1145 } 1146 break; 1147 } 1148 } 1149 1150 l2cap_run(); 1151 } 1152 1153 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1154 switch (packet_type) { 1155 case HCI_EVENT_PACKET: 1156 l2cap_event_handler(packet, size); 1157 break; 1158 case HCI_ACL_DATA_PACKET: 1159 l2cap_acl_handler(packet, size); 1160 break; 1161 default: 1162 break; 1163 } 1164 } 1165 1166 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1167 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1168 channel->state = L2CAP_STATE_CLOSED; 1169 l2cap_emit_channel_closed(channel); 1170 // discard channel 1171 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1172 btstack_memory_l2cap_channel_free(channel); 1173 } 1174 1175 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1176 linked_item_t *it; 1177 1178 // close open channels 1179 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 1180 l2cap_service_t * service = ((l2cap_service_t *) it); 1181 if ( service->psm == psm){ 1182 return service; 1183 }; 1184 } 1185 return NULL; 1186 } 1187 1188 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 1189 1190 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1191 1192 // check for alread registered psm 1193 // TODO: emit error event 1194 l2cap_service_t *service = l2cap_get_service(psm); 1195 if (service) { 1196 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 1197 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1198 return; 1199 } 1200 1201 // alloc structure 1202 // TODO: emit error event 1203 service = (l2cap_service_t *) btstack_memory_l2cap_service_get(); 1204 if (!service) { 1205 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 1206 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1207 return; 1208 } 1209 1210 // fill in 1211 service->psm = psm; 1212 service->mtu = mtu; 1213 service->connection = connection; 1214 service->packet_handler = packet_handler; 1215 1216 // add to services list 1217 linked_list_add(&l2cap_services, (linked_item_t *) service); 1218 1219 // enable page scan 1220 hci_connectable_control(1); 1221 1222 // done 1223 l2cap_emit_service_registered(connection, 0, psm); 1224 } 1225 1226 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1227 1228 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1229 1230 l2cap_service_t *service = l2cap_get_service(psm); 1231 if (!service) return; 1232 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1233 btstack_memory_l2cap_service_free(service); 1234 1235 // disable page scan when no services registered 1236 if (!linked_list_empty(&l2cap_services)) return; 1237 hci_connectable_control(0); 1238 } 1239 1240 // 1241 void l2cap_close_connection(void *connection){ 1242 linked_item_t *it; 1243 1244 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 1245 l2cap_channel_t * channel; 1246 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1247 channel = (l2cap_channel_t *) it; 1248 if (channel->connection == connection) { 1249 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1250 } 1251 } 1252 1253 // unregister services 1254 it = (linked_item_t *) &l2cap_services; 1255 while (it->next) { 1256 l2cap_service_t * service = (l2cap_service_t *) it->next; 1257 if (service->connection == connection){ 1258 it->next = it->next->next; 1259 btstack_memory_l2cap_service_free(service); 1260 } else { 1261 it = it->next; 1262 } 1263 } 1264 1265 // process 1266 l2cap_run(); 1267 } 1268 1269 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1270 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1271 switch(channel_id){ 1272 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1273 attribute_protocol_packet_handler = packet_handler; 1274 break; 1275 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1276 security_protocol_packet_handler = packet_handler; 1277 break; 1278 } 1279 } 1280 1281 #ifdef HAVE_BLE 1282 // Request LE connection parameter update 1283 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){ 1284 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 1285 log_info("l2cap_send_signaling_packet, cannot send\n"); 1286 return BTSTACK_ACL_BUFFERS_FULL; 1287 } 1288 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 1289 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 1290 uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); 1291 return hci_send_acl_packet(acl_buffer, len); 1292 } 1293 #endif 1294 1295