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 // also disconnect if result is 0x0003 - security blocked 435 hci_disconnect_security_block(handle); 436 break; 437 case ECHO_REQUEST: 438 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 439 break; 440 case INFORMATION_REQUEST: 441 switch (infoType){ 442 case 1: { // Connectionless MTU 443 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 444 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 445 break; 446 } 447 case 2: { // Extended Features Supported 448 // extended features request supported, only supporing fixed channel map 449 uint32_t features = 0x80; 450 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 451 break; 452 } 453 case 3: { // Fixed Channels Supported 454 uint8_t map[8]; 455 memset(map, 0, 8); 456 map[0] = 0x01; // L2CAP Signaling Channel 457 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 458 break; 459 } 460 default: 461 // all other types are not supported 462 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 463 break; 464 } 465 break; 466 case COMMAND_REJECT: 467 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result); 468 break; 469 default: 470 // should not happen 471 break; 472 } 473 474 // remove first item 475 signaling_responses_pending--; 476 int i; 477 for (i=0; i < signaling_responses_pending; i++){ 478 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 479 } 480 } 481 482 uint8_t config_options[4]; 483 linked_item_t *it; 484 linked_item_t *next; 485 for (it = (linked_item_t *) l2cap_channels; it ; it = next){ 486 next = it->next; // cache next item as current item might get freed 487 488 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 489 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)) break; 490 491 l2cap_channel_t * channel = (l2cap_channel_t *) it; 492 493 // log_info("l2cap_run: state %u, var 0x%02x\n", channel->state, channel->state_var); 494 495 496 switch (channel->state){ 497 498 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 499 if (channel->state_var & L2CAP_STATE_WAIT_AUTHENTICATION_RESULT) { 500 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 501 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, 1, 0); 502 } 503 break; 504 505 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 506 // send connection request - set state first 507 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 508 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 509 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 510 break; 511 512 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 513 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, channel->reason, 0); 514 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 515 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); // -- remove from list 516 btstack_memory_l2cap_channel_free(channel); 517 break; 518 519 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 520 channel->state = L2CAP_STATE_CONFIG; 521 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 522 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 523 break; 524 525 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 526 // success, start l2cap handshake 527 channel->local_sig_id = l2cap_next_sig_id(); 528 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 529 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 530 l2cap_start_rtx(channel); 531 break; 532 533 case L2CAP_STATE_CONFIG: 534 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 535 uint16_t flags = 0; 536 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 537 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 538 flags = 1; 539 } else { 540 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 541 } 542 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 543 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 544 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 545 config_options[0] = 1; // MTU 546 config_options[1] = 2; // len param 547 bt_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 548 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 549 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 550 } else { 551 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 552 } 553 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 554 } 555 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 556 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 557 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 558 channel->local_sig_id = l2cap_next_sig_id(); 559 config_options[0] = 1; // MTU 560 config_options[1] = 2; // len param 561 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 562 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 563 l2cap_start_rtx(channel); 564 } 565 if (l2cap_channel_ready_for_open(channel)){ 566 channel->state = L2CAP_STATE_OPEN; 567 l2cap_emit_channel_opened(channel, 0); // success 568 l2cap_emit_credits(channel, 1); 569 } 570 break; 571 572 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 573 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 574 // 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 :) 575 l2cap_finialize_channel_close(channel); // -- remove from list 576 break; 577 578 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 579 channel->local_sig_id = l2cap_next_sig_id(); 580 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 581 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 582 break; 583 default: 584 break; 585 } 586 } 587 } 588 589 uint16_t l2cap_max_mtu(void){ 590 return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE; 591 } 592 593 // open outgoing L2CAP channel 594 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 595 bd_addr_t address, uint16_t psm, uint16_t mtu){ 596 597 log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 598 599 // alloc structure 600 l2cap_channel_t * chan = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 601 if (!chan) { 602 // emit error event 603 l2cap_channel_t dummy_channel; 604 BD_ADDR_COPY(dummy_channel.address, address); 605 dummy_channel.psm = psm; 606 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 607 return; 608 } 609 // limit local mtu to max acl packet length 610 if (mtu > l2cap_max_mtu()) { 611 mtu = l2cap_max_mtu(); 612 } 613 614 // fill in 615 BD_ADDR_COPY(chan->address, address); 616 chan->psm = psm; 617 chan->handle = 0; 618 chan->connection = connection; 619 chan->packet_handler = packet_handler; 620 chan->remote_mtu = L2CAP_MINIMAL_MTU; 621 chan->local_mtu = mtu; 622 chan->packets_granted = 0; 623 624 // set initial state 625 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 626 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 627 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 628 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 629 630 // add to connections list 631 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 632 633 l2cap_run(); 634 } 635 636 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 637 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 638 // find channel for local_cid 639 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 640 if (channel) { 641 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 642 } 643 // process 644 l2cap_run(); 645 } 646 647 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 648 linked_item_t *it = (linked_item_t *) &l2cap_channels; 649 while (it->next){ 650 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 651 if ( ! BD_ADDR_CMP( channel->address, address) ){ 652 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 653 // failure, forward error code 654 l2cap_emit_channel_opened(channel, status); 655 // discard channel 656 it->next = it->next->next; 657 btstack_memory_l2cap_channel_free(channel); 658 } 659 } else { 660 it = it->next; 661 } 662 } 663 } 664 665 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 666 linked_item_t *it; 667 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 668 l2cap_channel_t * channel = (l2cap_channel_t *) it; 669 if ( ! BD_ADDR_CMP( channel->address, address) ){ 670 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 671 // success, start l2cap handshake 672 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 673 channel->handle = handle; 674 channel->local_cid = l2cap_next_local_cid(); 675 } 676 } 677 } 678 // process 679 l2cap_run(); 680 } 681 682 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 683 684 bd_addr_t address; 685 hci_con_handle_t handle; 686 l2cap_channel_t * channel; 687 linked_item_t *it; 688 int hci_con_used; 689 690 switch(packet[0]){ 691 692 // handle connection complete events 693 case HCI_EVENT_CONNECTION_COMPLETE: 694 bt_flip_addr(address, &packet[5]); 695 if (packet[2] == 0){ 696 handle = READ_BT_16(packet, 3); 697 l2cap_handle_connection_success_for_addr(address, handle); 698 } else { 699 l2cap_handle_connection_failed_for_addr(address, packet[2]); 700 } 701 break; 702 703 // handle successful create connection cancel command 704 case HCI_EVENT_COMMAND_COMPLETE: 705 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 706 if (packet[5] == 0){ 707 bt_flip_addr(address, &packet[6]); 708 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 709 l2cap_handle_connection_failed_for_addr(address, 0x16); 710 } 711 } 712 l2cap_run(); // try sending signaling packets first 713 break; 714 715 case HCI_EVENT_COMMAND_STATUS: 716 l2cap_run(); // try sending signaling packets first 717 break; 718 719 // handle disconnection complete events 720 case HCI_EVENT_DISCONNECTION_COMPLETE: 721 // send l2cap disconnect events for all channels on this handle 722 handle = READ_BT_16(packet, 3); 723 it = (linked_item_t *) &l2cap_channels; 724 while (it->next){ 725 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 726 if ( channel->handle == handle ){ 727 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 728 it->next = it->next->next; 729 l2cap_emit_channel_closed(channel); 730 btstack_memory_l2cap_channel_free(channel); 731 } else { 732 it = it->next; 733 } 734 } 735 break; 736 737 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 738 l2cap_run(); // try sending signaling packets first 739 l2cap_hand_out_credits(); 740 break; 741 742 // HCI Connection Timeouts 743 case L2CAP_EVENT_TIMEOUT_CHECK: 744 handle = READ_BT_16(packet, 2); 745 if (hci_authentication_active_for_handle(handle)) break; 746 hci_con_used = 0; 747 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 748 channel = (l2cap_channel_t *) it; 749 if (channel->handle == handle) { 750 hci_con_used = 1; 751 } 752 } 753 if (hci_con_used) break; 754 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 755 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 756 break; 757 758 case DAEMON_EVENT_HCI_PACKET_SENT: 759 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 760 channel = (l2cap_channel_t *) it; 761 if (channel->packet_handler) { 762 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 763 } 764 } 765 if (attribute_protocol_packet_handler) { 766 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 767 } 768 if (security_protocol_packet_handler) { 769 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 770 } 771 break; 772 773 case GAP_AUTHENTICATION_RESULT: 774 handle = READ_BT_16(packet, 3); 775 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 776 channel = (l2cap_channel_t *) it; 777 if (channel->handle != handle) continue; 778 if (channel->state != L2CAP_STATE_WAIT_AUTHENTICATION_RESULT) continue; 779 if (packet[2]){ 780 // fail 781 channel->reason = 0x03; // security block 782 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 783 } else { 784 // success 785 // @todo check sercurity level again 786 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 787 l2cap_emit_connection_request(channel); 788 } 789 } 790 break; 791 792 default: 793 break; 794 } 795 796 // pass on 797 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 798 } 799 800 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 801 channel->remote_sig_id = identifier; 802 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 803 l2cap_run(); 804 } 805 806 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 807 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 808 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 809 signaling_responses[signaling_responses_pending].handle = handle; 810 signaling_responses[signaling_responses_pending].code = code; 811 signaling_responses[signaling_responses_pending].sig_id = sig_id; 812 signaling_responses[signaling_responses_pending].data = data; 813 signaling_responses_pending++; 814 l2cap_run(); 815 } 816 } 817 818 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 819 820 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x\n", handle, psm, source_cid); 821 l2cap_service_t *service = l2cap_get_service(psm); 822 if (!service) { 823 // 0x0002 PSM not supported 824 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 825 return; 826 } 827 828 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 829 if (!hci_connection) { 830 // 831 log_error("no hci_connection for handle %u\n", handle); 832 return; 833 } 834 835 // reject connection (0x03 security block) and disconnect if both have SSP, connection is not encrypted and PSM != SDP 836 if (psm != PSM_SDP 837 && hci_local_ssp_activated() 838 && hci_remote_ssp_supported(handle) 839 && gap_security_level(handle) == LEVEL_0){ 840 841 // 0x0003 Security Block 842 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0003); 843 return; 844 } 845 846 847 // alloc structure 848 // log_info("l2cap_handle_connection_request register channel\n"); 849 l2cap_channel_t * channel = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 850 if (!channel){ 851 // 0x0004 No resources available 852 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 853 return; 854 } 855 856 // fill in 857 BD_ADDR_COPY(channel->address, hci_connection->address); 858 channel->psm = psm; 859 channel->handle = handle; 860 channel->connection = service->connection; 861 channel->packet_handler = service->packet_handler; 862 channel->local_cid = l2cap_next_local_cid(); 863 channel->remote_cid = source_cid; 864 channel->local_mtu = service->mtu; 865 channel->remote_mtu = L2CAP_DEFAULT_MTU; 866 channel->packets_granted = 0; 867 channel->remote_sig_id = sig_id; 868 869 // limit local mtu to max acl packet length 870 if (channel->local_mtu > l2cap_max_mtu()) { 871 channel->local_mtu = l2cap_max_mtu(); 872 } 873 874 // set initial state 875 channel->state = L2CAP_STATE_WAIT_AUTHENTICATION_RESULT; 876 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 877 878 // add to connections list 879 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 880 881 // assert security requirements 882 gap_security_level_t required_level = LEVEL_0; 883 gap_request_security_level(handle, required_level); 884 } 885 886 void l2cap_accept_connection_internal(uint16_t local_cid){ 887 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 888 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 889 if (!channel) { 890 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 891 return; 892 } 893 894 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 895 896 // process 897 l2cap_run(); 898 } 899 900 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 901 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); 902 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 903 if (!channel) { 904 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 905 return; 906 } 907 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 908 channel->reason = reason; 909 l2cap_run(); 910 } 911 912 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 913 914 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 915 916 uint16_t flags = READ_BT_16(command, 6); 917 if (flags & 1) { 918 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 919 } 920 921 // accept the other's configuration options 922 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 923 uint16_t pos = 8; 924 while (pos < end_pos){ 925 uint8_t option_hint = command[pos] >> 7; 926 uint8_t option_type = command[pos] & 0x7f; 927 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 928 pos++; 929 uint8_t length = command[pos++]; 930 // MTU { type(8): 1, len(8):2, MTU(16) } 931 if (option_type == 1 && length == 2){ 932 channel->remote_mtu = READ_BT_16(command, pos); 933 // log_info("l2cap cid 0x%02x, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 934 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 935 } 936 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 937 if (option_type == 2 && length == 2){ 938 channel->flush_timeout = READ_BT_16(command, pos); 939 } 940 // check for unknown options 941 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 942 log_info("l2cap cid %u, unknown options", channel->local_cid); 943 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 944 } 945 pos += length; 946 } 947 } 948 949 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 950 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 951 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 952 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 953 return 1; 954 } 955 956 957 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 958 959 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 960 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 961 uint16_t result = 0; 962 963 log_info("L2CAP signaling handler code %u, state %u\n", code, channel->state); 964 965 // handle DISCONNECT REQUESTS seperately 966 if (code == DISCONNECTION_REQUEST){ 967 switch (channel->state){ 968 case L2CAP_STATE_CONFIG: 969 case L2CAP_STATE_OPEN: 970 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 971 case L2CAP_STATE_WAIT_DISCONNECT: 972 l2cap_handle_disconnect_request(channel, identifier); 973 break; 974 975 default: 976 // ignore in other states 977 break; 978 } 979 return; 980 } 981 982 // @STATEMACHINE(l2cap) 983 switch (channel->state) { 984 985 case L2CAP_STATE_WAIT_CONNECT_RSP: 986 switch (code){ 987 case CONNECTION_RESPONSE: 988 l2cap_stop_rtx(channel); 989 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 990 switch (result) { 991 case 0: 992 // successful connection 993 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 994 channel->state = L2CAP_STATE_CONFIG; 995 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 996 break; 997 case 1: 998 // connection pending. get some coffee, but start the ERTX 999 l2cap_start_ertx(channel); 1000 break; 1001 default: 1002 // channel closed 1003 channel->state = L2CAP_STATE_CLOSED; 1004 // map l2cap connection response result to BTstack status enumeration 1005 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1006 1007 // drop link key if security block 1008 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1009 hci_drop_link_key_for_bd_addr(&channel->address); 1010 } 1011 1012 // discard channel 1013 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1014 btstack_memory_l2cap_channel_free(channel); 1015 break; 1016 } 1017 break; 1018 1019 default: 1020 //@TODO: implement other signaling packets 1021 break; 1022 } 1023 break; 1024 1025 case L2CAP_STATE_CONFIG: 1026 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1027 switch (code) { 1028 case CONFIGURE_REQUEST: 1029 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1030 l2cap_signaling_handle_configure_request(channel, command); 1031 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1032 // only done if continuation not set 1033 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1034 } 1035 break; 1036 case CONFIGURE_RESPONSE: 1037 l2cap_stop_rtx(channel); 1038 switch (result){ 1039 case 0: // success 1040 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1041 break; 1042 case 4: // pending 1043 l2cap_start_ertx(channel); 1044 break; 1045 default: 1046 // retry on negative result 1047 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1048 break; 1049 } 1050 break; 1051 default: 1052 break; 1053 } 1054 if (l2cap_channel_ready_for_open(channel)){ 1055 // for open: 1056 channel->state = L2CAP_STATE_OPEN; 1057 l2cap_emit_channel_opened(channel, 0); 1058 l2cap_emit_credits(channel, 1); 1059 } 1060 break; 1061 1062 case L2CAP_STATE_WAIT_DISCONNECT: 1063 switch (code) { 1064 case DISCONNECTION_RESPONSE: 1065 l2cap_finialize_channel_close(channel); 1066 break; 1067 default: 1068 //@TODO: implement other signaling packets 1069 break; 1070 } 1071 break; 1072 1073 case L2CAP_STATE_CLOSED: 1074 // @TODO handle incoming requests 1075 break; 1076 1077 case L2CAP_STATE_OPEN: 1078 //@TODO: implement other signaling packets, e.g. re-configure 1079 break; 1080 default: 1081 break; 1082 } 1083 // log_info("new state %u\n", channel->state); 1084 } 1085 1086 1087 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1088 1089 // get code, signalind identifier and command len 1090 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1091 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1092 1093 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1094 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1095 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1096 return; 1097 } 1098 1099 // general commands without an assigned channel 1100 switch(code) { 1101 1102 case CONNECTION_REQUEST: { 1103 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1104 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1105 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1106 return; 1107 } 1108 1109 case ECHO_REQUEST: 1110 l2cap_register_signaling_response(handle, code, sig_id, 0); 1111 return; 1112 1113 case INFORMATION_REQUEST: { 1114 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1115 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1116 return; 1117 } 1118 1119 default: 1120 break; 1121 } 1122 1123 1124 // Get potential destination CID 1125 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1126 1127 // Find channel for this sig_id and connection handle 1128 linked_item_t *it; 1129 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1130 l2cap_channel_t * channel = (l2cap_channel_t *) it; 1131 if (channel->handle == handle) { 1132 if (code & 1) { 1133 // match odd commands (responses) by previous signaling identifier 1134 if (channel->local_sig_id == sig_id) { 1135 l2cap_signaling_handler_channel(channel, command); 1136 break; 1137 } 1138 } else { 1139 // match even commands (requests) by local channel id 1140 if (channel->local_cid == dest_cid) { 1141 l2cap_signaling_handler_channel(channel, command); 1142 break; 1143 } 1144 } 1145 } 1146 } 1147 } 1148 1149 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 1150 1151 // Get Channel ID 1152 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1153 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1154 1155 switch (channel_id) { 1156 1157 case L2CAP_CID_SIGNALING: { 1158 1159 uint16_t command_offset = 8; 1160 while (command_offset < size) { 1161 1162 // handle signaling commands 1163 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1164 1165 // increment command_offset 1166 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1167 } 1168 break; 1169 } 1170 1171 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1172 if (attribute_protocol_packet_handler) { 1173 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1174 } 1175 break; 1176 1177 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1178 if (security_protocol_packet_handler) { 1179 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1180 } 1181 break; 1182 1183 default: { 1184 // Find channel for this channel_id and connection handle 1185 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1186 if (channel) { 1187 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1188 } 1189 break; 1190 } 1191 } 1192 1193 l2cap_run(); 1194 } 1195 1196 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1197 switch (packet_type) { 1198 case HCI_EVENT_PACKET: 1199 l2cap_event_handler(packet, size); 1200 break; 1201 case HCI_ACL_DATA_PACKET: 1202 l2cap_acl_handler(packet, size); 1203 break; 1204 default: 1205 break; 1206 } 1207 } 1208 1209 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1210 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1211 channel->state = L2CAP_STATE_CLOSED; 1212 l2cap_emit_channel_closed(channel); 1213 // discard channel 1214 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1215 btstack_memory_l2cap_channel_free(channel); 1216 } 1217 1218 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1219 linked_item_t *it; 1220 1221 // close open channels 1222 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 1223 l2cap_service_t * service = ((l2cap_service_t *) it); 1224 if ( service->psm == psm){ 1225 return service; 1226 }; 1227 } 1228 return NULL; 1229 } 1230 1231 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 1232 1233 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1234 1235 // check for alread registered psm 1236 // TODO: emit error event 1237 l2cap_service_t *service = l2cap_get_service(psm); 1238 if (service) { 1239 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 1240 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1241 return; 1242 } 1243 1244 // alloc structure 1245 // TODO: emit error event 1246 service = (l2cap_service_t *) btstack_memory_l2cap_service_get(); 1247 if (!service) { 1248 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 1249 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1250 return; 1251 } 1252 1253 // fill in 1254 service->psm = psm; 1255 service->mtu = mtu; 1256 service->connection = connection; 1257 service->packet_handler = packet_handler; 1258 1259 // add to services list 1260 linked_list_add(&l2cap_services, (linked_item_t *) service); 1261 1262 // enable page scan 1263 hci_connectable_control(1); 1264 1265 // done 1266 l2cap_emit_service_registered(connection, 0, psm); 1267 } 1268 1269 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1270 1271 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1272 1273 l2cap_service_t *service = l2cap_get_service(psm); 1274 if (!service) return; 1275 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1276 btstack_memory_l2cap_service_free(service); 1277 1278 // disable page scan when no services registered 1279 if (!linked_list_empty(&l2cap_services)) return; 1280 hci_connectable_control(0); 1281 } 1282 1283 // 1284 void l2cap_close_connection(void *connection){ 1285 linked_item_t *it; 1286 1287 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 1288 l2cap_channel_t * channel; 1289 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1290 channel = (l2cap_channel_t *) it; 1291 if (channel->connection == connection) { 1292 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1293 } 1294 } 1295 1296 // unregister services 1297 it = (linked_item_t *) &l2cap_services; 1298 while (it->next) { 1299 l2cap_service_t * service = (l2cap_service_t *) it->next; 1300 if (service->connection == connection){ 1301 it->next = it->next->next; 1302 btstack_memory_l2cap_service_free(service); 1303 } else { 1304 it = it->next; 1305 } 1306 } 1307 1308 // process 1309 l2cap_run(); 1310 } 1311 1312 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1313 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1314 switch(channel_id){ 1315 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1316 attribute_protocol_packet_handler = packet_handler; 1317 break; 1318 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1319 security_protocol_packet_handler = packet_handler; 1320 break; 1321 } 1322 } 1323 1324 #ifdef HAVE_BLE 1325 // Request LE connection parameter update 1326 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){ 1327 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 1328 log_info("l2cap_send_signaling_packet, cannot send\n"); 1329 return BTSTACK_ACL_BUFFERS_FULL; 1330 } 1331 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 1332 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 1333 uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); 1334 return hci_send_acl_packet(acl_buffer, len); 1335 } 1336 #endif 1337 1338