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_SECURITY_LEVEL_UPDATE: 499 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 500 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 501 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 502 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 503 } 504 break; 505 506 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 507 // send connection request - set state first 508 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 509 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 510 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 511 break; 512 513 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 514 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, 0, 0, channel->reason, 0); 515 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 516 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); // -- remove from list 517 btstack_memory_l2cap_channel_free(channel); 518 break; 519 520 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 521 channel->state = L2CAP_STATE_CONFIG; 522 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 523 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 524 break; 525 526 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 527 // success, start l2cap handshake 528 channel->local_sig_id = l2cap_next_sig_id(); 529 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 530 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 531 l2cap_start_rtx(channel); 532 break; 533 534 case L2CAP_STATE_CONFIG: 535 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 536 uint16_t flags = 0; 537 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 538 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 539 flags = 1; 540 } else { 541 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 542 } 543 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 544 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 545 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 546 config_options[0] = 1; // MTU 547 config_options[1] = 2; // len param 548 bt_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 549 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 550 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 551 } else { 552 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 553 } 554 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 555 } 556 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 557 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 558 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 559 channel->local_sig_id = l2cap_next_sig_id(); 560 config_options[0] = 1; // MTU 561 config_options[1] = 2; // len param 562 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 563 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 564 l2cap_start_rtx(channel); 565 } 566 if (l2cap_channel_ready_for_open(channel)){ 567 channel->state = L2CAP_STATE_OPEN; 568 l2cap_emit_channel_opened(channel, 0); // success 569 l2cap_emit_credits(channel, 1); 570 } 571 break; 572 573 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 574 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 575 // 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 :) 576 l2cap_finialize_channel_close(channel); // -- remove from list 577 break; 578 579 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 580 channel->local_sig_id = l2cap_next_sig_id(); 581 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 582 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 583 break; 584 default: 585 break; 586 } 587 } 588 } 589 590 uint16_t l2cap_max_mtu(void){ 591 return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE; 592 } 593 594 // open outgoing L2CAP channel 595 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 596 bd_addr_t address, uint16_t psm, uint16_t mtu){ 597 598 log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 599 600 // alloc structure 601 l2cap_channel_t * chan = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 602 if (!chan) { 603 // emit error event 604 l2cap_channel_t dummy_channel; 605 BD_ADDR_COPY(dummy_channel.address, address); 606 dummy_channel.psm = psm; 607 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 608 return; 609 } 610 // limit local mtu to max acl packet length 611 if (mtu > l2cap_max_mtu()) { 612 mtu = l2cap_max_mtu(); 613 } 614 615 // fill in 616 BD_ADDR_COPY(chan->address, address); 617 chan->psm = psm; 618 chan->handle = 0; 619 chan->connection = connection; 620 chan->packet_handler = packet_handler; 621 chan->remote_mtu = L2CAP_MINIMAL_MTU; 622 chan->local_mtu = mtu; 623 chan->packets_granted = 0; 624 625 // set initial state 626 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 627 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 628 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 629 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 630 631 // add to connections list 632 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 633 634 l2cap_run(); 635 } 636 637 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 638 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 639 // find channel for local_cid 640 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 641 if (channel) { 642 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 643 } 644 // process 645 l2cap_run(); 646 } 647 648 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 649 linked_item_t *it = (linked_item_t *) &l2cap_channels; 650 while (it->next){ 651 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 652 if ( ! BD_ADDR_CMP( channel->address, address) ){ 653 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 654 // failure, forward error code 655 l2cap_emit_channel_opened(channel, status); 656 // discard channel 657 it->next = it->next->next; 658 btstack_memory_l2cap_channel_free(channel); 659 } 660 } else { 661 it = it->next; 662 } 663 } 664 } 665 666 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 667 linked_item_t *it; 668 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 669 l2cap_channel_t * channel = (l2cap_channel_t *) it; 670 if ( ! BD_ADDR_CMP( channel->address, address) ){ 671 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 672 // success, start l2cap handshake 673 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 674 channel->handle = handle; 675 channel->local_cid = l2cap_next_local_cid(); 676 } 677 } 678 } 679 // process 680 l2cap_run(); 681 } 682 683 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 684 685 bd_addr_t address; 686 hci_con_handle_t handle; 687 l2cap_channel_t * channel; 688 linked_item_t *it; 689 int hci_con_used; 690 691 switch(packet[0]){ 692 693 // handle connection complete events 694 case HCI_EVENT_CONNECTION_COMPLETE: 695 bt_flip_addr(address, &packet[5]); 696 if (packet[2] == 0){ 697 handle = READ_BT_16(packet, 3); 698 l2cap_handle_connection_success_for_addr(address, handle); 699 } else { 700 l2cap_handle_connection_failed_for_addr(address, packet[2]); 701 } 702 break; 703 704 // handle successful create connection cancel command 705 case HCI_EVENT_COMMAND_COMPLETE: 706 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 707 if (packet[5] == 0){ 708 bt_flip_addr(address, &packet[6]); 709 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 710 l2cap_handle_connection_failed_for_addr(address, 0x16); 711 } 712 } 713 l2cap_run(); // try sending signaling packets first 714 break; 715 716 case HCI_EVENT_COMMAND_STATUS: 717 l2cap_run(); // try sending signaling packets first 718 break; 719 720 // handle disconnection complete events 721 case HCI_EVENT_DISCONNECTION_COMPLETE: 722 // send l2cap disconnect events for all channels on this handle 723 handle = READ_BT_16(packet, 3); 724 it = (linked_item_t *) &l2cap_channels; 725 while (it->next){ 726 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 727 if ( channel->handle == handle ){ 728 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 729 it->next = it->next->next; 730 l2cap_emit_channel_closed(channel); 731 btstack_memory_l2cap_channel_free(channel); 732 } else { 733 it = it->next; 734 } 735 } 736 break; 737 738 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 739 l2cap_run(); // try sending signaling packets first 740 l2cap_hand_out_credits(); 741 break; 742 743 // HCI Connection Timeouts 744 case L2CAP_EVENT_TIMEOUT_CHECK: 745 handle = READ_BT_16(packet, 2); 746 if (hci_authentication_active_for_handle(handle)) break; 747 hci_con_used = 0; 748 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 749 channel = (l2cap_channel_t *) it; 750 if (channel->handle == handle) { 751 hci_con_used = 1; 752 } 753 } 754 if (hci_con_used) break; 755 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 756 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 757 break; 758 759 case DAEMON_EVENT_HCI_PACKET_SENT: 760 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 761 channel = (l2cap_channel_t *) it; 762 if (channel->packet_handler) { 763 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 764 } 765 } 766 if (attribute_protocol_packet_handler) { 767 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 768 } 769 if (security_protocol_packet_handler) { 770 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 771 } 772 break; 773 774 case GAP_SECURITY_LEVEL: 775 handle = READ_BT_16(packet, 2); 776 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 777 channel = (l2cap_channel_t *) it; 778 if (channel->handle != handle) continue; 779 if (channel->state != L2CAP_STATE_WAIT_SECURITY_LEVEL_UPDATE) continue; 780 // @todo check security level again 781 // channel->reason = 0x03; // security block 782 // channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 783 // success 784 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 785 l2cap_emit_connection_request(channel); 786 } 787 break; 788 789 default: 790 break; 791 } 792 793 // pass on 794 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 795 } 796 797 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 798 channel->remote_sig_id = identifier; 799 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 800 l2cap_run(); 801 } 802 803 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 804 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 805 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 806 signaling_responses[signaling_responses_pending].handle = handle; 807 signaling_responses[signaling_responses_pending].code = code; 808 signaling_responses[signaling_responses_pending].sig_id = sig_id; 809 signaling_responses[signaling_responses_pending].data = data; 810 signaling_responses_pending++; 811 l2cap_run(); 812 } 813 } 814 815 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 816 817 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x\n", handle, psm, source_cid); 818 l2cap_service_t *service = l2cap_get_service(psm); 819 if (!service) { 820 // 0x0002 PSM not supported 821 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 822 return; 823 } 824 825 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 826 if (!hci_connection) { 827 // 828 log_error("no hci_connection for handle %u\n", handle); 829 return; 830 } 831 832 // reject connection (0x03 security block) and disconnect if both have SSP, connection is not encrypted and PSM != SDP 833 if (psm != PSM_SDP 834 && hci_local_ssp_activated() 835 && hci_remote_ssp_supported(handle) 836 && gap_security_level(handle) == LEVEL_0){ 837 838 // 0x0003 Security Block 839 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0003); 840 return; 841 } 842 843 844 // alloc structure 845 // log_info("l2cap_handle_connection_request register channel\n"); 846 l2cap_channel_t * channel = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 847 if (!channel){ 848 // 0x0004 No resources available 849 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 850 return; 851 } 852 853 // fill in 854 BD_ADDR_COPY(channel->address, hci_connection->address); 855 channel->psm = psm; 856 channel->handle = handle; 857 channel->connection = service->connection; 858 channel->packet_handler = service->packet_handler; 859 channel->local_cid = l2cap_next_local_cid(); 860 channel->remote_cid = source_cid; 861 channel->local_mtu = service->mtu; 862 channel->remote_mtu = L2CAP_DEFAULT_MTU; 863 channel->packets_granted = 0; 864 channel->remote_sig_id = sig_id; 865 866 // limit local mtu to max acl packet length 867 if (channel->local_mtu > l2cap_max_mtu()) { 868 channel->local_mtu = l2cap_max_mtu(); 869 } 870 871 // set initial state 872 channel->state = L2CAP_STATE_WAIT_SECURITY_LEVEL_UPDATE; 873 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 874 875 // add to connections list 876 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 877 878 // assert security requirements 879 gap_security_level_t required_level = LEVEL_0; 880 gap_request_security_level(handle, required_level); 881 } 882 883 void l2cap_accept_connection_internal(uint16_t local_cid){ 884 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 885 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 886 if (!channel) { 887 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 888 return; 889 } 890 891 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 892 893 // process 894 l2cap_run(); 895 } 896 897 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 898 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); 899 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 900 if (!channel) { 901 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 902 return; 903 } 904 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 905 channel->reason = reason; 906 l2cap_run(); 907 } 908 909 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 910 911 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 912 913 uint16_t flags = READ_BT_16(command, 6); 914 if (flags & 1) { 915 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 916 } 917 918 // accept the other's configuration options 919 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 920 uint16_t pos = 8; 921 while (pos < end_pos){ 922 uint8_t option_hint = command[pos] >> 7; 923 uint8_t option_type = command[pos] & 0x7f; 924 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 925 pos++; 926 uint8_t length = command[pos++]; 927 // MTU { type(8): 1, len(8):2, MTU(16) } 928 if (option_type == 1 && length == 2){ 929 channel->remote_mtu = READ_BT_16(command, pos); 930 // log_info("l2cap cid 0x%02x, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 931 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 932 } 933 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 934 if (option_type == 2 && length == 2){ 935 channel->flush_timeout = READ_BT_16(command, pos); 936 } 937 // check for unknown options 938 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 939 log_info("l2cap cid %u, unknown options", channel->local_cid); 940 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 941 } 942 pos += length; 943 } 944 } 945 946 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 947 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 948 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 949 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 950 return 1; 951 } 952 953 954 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 955 956 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 957 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 958 uint16_t result = 0; 959 960 log_info("L2CAP signaling handler code %u, state %u\n", code, channel->state); 961 962 // handle DISCONNECT REQUESTS seperately 963 if (code == DISCONNECTION_REQUEST){ 964 switch (channel->state){ 965 case L2CAP_STATE_CONFIG: 966 case L2CAP_STATE_OPEN: 967 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 968 case L2CAP_STATE_WAIT_DISCONNECT: 969 l2cap_handle_disconnect_request(channel, identifier); 970 break; 971 972 default: 973 // ignore in other states 974 break; 975 } 976 return; 977 } 978 979 // @STATEMACHINE(l2cap) 980 switch (channel->state) { 981 982 case L2CAP_STATE_WAIT_CONNECT_RSP: 983 switch (code){ 984 case CONNECTION_RESPONSE: 985 l2cap_stop_rtx(channel); 986 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 987 switch (result) { 988 case 0: 989 // successful connection 990 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 991 channel->state = L2CAP_STATE_CONFIG; 992 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 993 break; 994 case 1: 995 // connection pending. get some coffee, but start the ERTX 996 l2cap_start_ertx(channel); 997 break; 998 default: 999 // channel closed 1000 channel->state = L2CAP_STATE_CLOSED; 1001 // map l2cap connection response result to BTstack status enumeration 1002 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1003 1004 // drop link key if security block 1005 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1006 hci_drop_link_key_for_bd_addr(&channel->address); 1007 } 1008 1009 // discard channel 1010 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1011 btstack_memory_l2cap_channel_free(channel); 1012 break; 1013 } 1014 break; 1015 1016 default: 1017 //@TODO: implement other signaling packets 1018 break; 1019 } 1020 break; 1021 1022 case L2CAP_STATE_CONFIG: 1023 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1024 switch (code) { 1025 case CONFIGURE_REQUEST: 1026 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1027 l2cap_signaling_handle_configure_request(channel, command); 1028 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1029 // only done if continuation not set 1030 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1031 } 1032 break; 1033 case CONFIGURE_RESPONSE: 1034 l2cap_stop_rtx(channel); 1035 switch (result){ 1036 case 0: // success 1037 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1038 break; 1039 case 4: // pending 1040 l2cap_start_ertx(channel); 1041 break; 1042 default: 1043 // retry on negative result 1044 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1045 break; 1046 } 1047 break; 1048 default: 1049 break; 1050 } 1051 if (l2cap_channel_ready_for_open(channel)){ 1052 // for open: 1053 channel->state = L2CAP_STATE_OPEN; 1054 l2cap_emit_channel_opened(channel, 0); 1055 l2cap_emit_credits(channel, 1); 1056 } 1057 break; 1058 1059 case L2CAP_STATE_WAIT_DISCONNECT: 1060 switch (code) { 1061 case DISCONNECTION_RESPONSE: 1062 l2cap_finialize_channel_close(channel); 1063 break; 1064 default: 1065 //@TODO: implement other signaling packets 1066 break; 1067 } 1068 break; 1069 1070 case L2CAP_STATE_CLOSED: 1071 // @TODO handle incoming requests 1072 break; 1073 1074 case L2CAP_STATE_OPEN: 1075 //@TODO: implement other signaling packets, e.g. re-configure 1076 break; 1077 default: 1078 break; 1079 } 1080 // log_info("new state %u\n", channel->state); 1081 } 1082 1083 1084 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1085 1086 // get code, signalind identifier and command len 1087 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1088 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1089 1090 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1091 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1092 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1093 return; 1094 } 1095 1096 // general commands without an assigned channel 1097 switch(code) { 1098 1099 case CONNECTION_REQUEST: { 1100 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1101 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1102 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1103 return; 1104 } 1105 1106 case ECHO_REQUEST: 1107 l2cap_register_signaling_response(handle, code, sig_id, 0); 1108 return; 1109 1110 case INFORMATION_REQUEST: { 1111 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1112 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1113 return; 1114 } 1115 1116 default: 1117 break; 1118 } 1119 1120 1121 // Get potential destination CID 1122 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1123 1124 // Find channel for this sig_id and connection handle 1125 linked_item_t *it; 1126 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1127 l2cap_channel_t * channel = (l2cap_channel_t *) it; 1128 if (channel->handle == handle) { 1129 if (code & 1) { 1130 // match odd commands (responses) by previous signaling identifier 1131 if (channel->local_sig_id == sig_id) { 1132 l2cap_signaling_handler_channel(channel, command); 1133 break; 1134 } 1135 } else { 1136 // match even commands (requests) by local channel id 1137 if (channel->local_cid == dest_cid) { 1138 l2cap_signaling_handler_channel(channel, command); 1139 break; 1140 } 1141 } 1142 } 1143 } 1144 } 1145 1146 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 1147 1148 // Get Channel ID 1149 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1150 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1151 1152 switch (channel_id) { 1153 1154 case L2CAP_CID_SIGNALING: { 1155 1156 uint16_t command_offset = 8; 1157 while (command_offset < size) { 1158 1159 // handle signaling commands 1160 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1161 1162 // increment command_offset 1163 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1164 } 1165 break; 1166 } 1167 1168 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1169 if (attribute_protocol_packet_handler) { 1170 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1171 } 1172 break; 1173 1174 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1175 if (security_protocol_packet_handler) { 1176 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1177 } 1178 break; 1179 1180 default: { 1181 // Find channel for this channel_id and connection handle 1182 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1183 if (channel) { 1184 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1185 } 1186 break; 1187 } 1188 } 1189 1190 l2cap_run(); 1191 } 1192 1193 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1194 switch (packet_type) { 1195 case HCI_EVENT_PACKET: 1196 l2cap_event_handler(packet, size); 1197 break; 1198 case HCI_ACL_DATA_PACKET: 1199 l2cap_acl_handler(packet, size); 1200 break; 1201 default: 1202 break; 1203 } 1204 } 1205 1206 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1207 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1208 channel->state = L2CAP_STATE_CLOSED; 1209 l2cap_emit_channel_closed(channel); 1210 // discard channel 1211 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1212 btstack_memory_l2cap_channel_free(channel); 1213 } 1214 1215 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1216 linked_item_t *it; 1217 1218 // close open channels 1219 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 1220 l2cap_service_t * service = ((l2cap_service_t *) it); 1221 if ( service->psm == psm){ 1222 return service; 1223 }; 1224 } 1225 return NULL; 1226 } 1227 1228 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu){ 1229 1230 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1231 1232 // check for alread registered psm 1233 // TODO: emit error event 1234 l2cap_service_t *service = l2cap_get_service(psm); 1235 if (service) { 1236 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 1237 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1238 return; 1239 } 1240 1241 // alloc structure 1242 // TODO: emit error event 1243 service = (l2cap_service_t *) btstack_memory_l2cap_service_get(); 1244 if (!service) { 1245 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 1246 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1247 return; 1248 } 1249 1250 // fill in 1251 service->psm = psm; 1252 service->mtu = mtu; 1253 service->connection = connection; 1254 service->packet_handler = packet_handler; 1255 1256 // add to services list 1257 linked_list_add(&l2cap_services, (linked_item_t *) service); 1258 1259 // enable page scan 1260 hci_connectable_control(1); 1261 1262 // done 1263 l2cap_emit_service_registered(connection, 0, psm); 1264 } 1265 1266 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1267 1268 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1269 1270 l2cap_service_t *service = l2cap_get_service(psm); 1271 if (!service) return; 1272 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1273 btstack_memory_l2cap_service_free(service); 1274 1275 // disable page scan when no services registered 1276 if (!linked_list_empty(&l2cap_services)) return; 1277 hci_connectable_control(0); 1278 } 1279 1280 // 1281 void l2cap_close_connection(void *connection){ 1282 linked_item_t *it; 1283 1284 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 1285 l2cap_channel_t * channel; 1286 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1287 channel = (l2cap_channel_t *) it; 1288 if (channel->connection == connection) { 1289 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1290 } 1291 } 1292 1293 // unregister services 1294 it = (linked_item_t *) &l2cap_services; 1295 while (it->next) { 1296 l2cap_service_t * service = (l2cap_service_t *) it->next; 1297 if (service->connection == connection){ 1298 it->next = it->next->next; 1299 btstack_memory_l2cap_service_free(service); 1300 } else { 1301 it = it->next; 1302 } 1303 } 1304 1305 // process 1306 l2cap_run(); 1307 } 1308 1309 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1310 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1311 switch(channel_id){ 1312 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1313 attribute_protocol_packet_handler = packet_handler; 1314 break; 1315 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1316 security_protocol_packet_handler = packet_handler; 1317 break; 1318 } 1319 } 1320 1321 #ifdef HAVE_BLE 1322 // Request LE connection parameter update 1323 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){ 1324 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 1325 log_info("l2cap_send_signaling_packet, cannot send\n"); 1326 return BTSTACK_ACL_BUFFERS_FULL; 1327 } 1328 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 1329 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 1330 uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); 1331 return hci_send_acl_packet(acl_buffer, len); 1332 } 1333 #endif 1334 1335