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; 76 static linked_list_t l2cap_services; 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; 81 static btstack_packet_handler_t security_protocol_packet_handler; 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 attribute_protocol_packet_handler = NULL; 101 security_protocol_packet_handler = NULL; 102 103 // 104 // register callback with HCI 105 // 106 hci_register_packet_handler(&l2cap_packet_handler); 107 hci_connectable_control(0); // no services yet 108 } 109 110 111 /** Register L2CAP packet handlers */ 112 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 113 } 114 void l2cap_register_packet_handler(void (*handler)(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 115 packet_handler = handler; 116 } 117 118 // notify client/protocol handler 119 void l2cap_dispatch(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 120 if (channel->packet_handler) { 121 (* (channel->packet_handler))(type, channel->local_cid, data, size); 122 } else { 123 (*packet_handler)(channel->connection, type, channel->local_cid, data, size); 124 } 125 } 126 127 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 128 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", 129 status, bd_addr_to_str(channel->address), channel->handle, channel->psm, 130 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 131 uint8_t event[23]; 132 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 133 event[1] = sizeof(event) - 2; 134 event[2] = status; 135 bt_flip_addr(&event[3], channel->address); 136 bt_store_16(event, 9, channel->handle); 137 bt_store_16(event, 11, channel->psm); 138 bt_store_16(event, 13, channel->local_cid); 139 bt_store_16(event, 15, channel->remote_cid); 140 bt_store_16(event, 17, channel->local_mtu); 141 bt_store_16(event, 19, channel->remote_mtu); 142 bt_store_16(event, 19, channel->flush_timeout); 143 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 144 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 145 } 146 147 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 148 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 149 uint8_t event[4]; 150 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 151 event[1] = sizeof(event) - 2; 152 bt_store_16(event, 2, channel->local_cid); 153 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 154 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 155 } 156 157 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 158 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 159 bd_addr_to_str(channel->address), channel->handle, channel->psm, channel->local_cid, channel->remote_cid); 160 uint8_t event[16]; 161 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 162 event[1] = sizeof(event) - 2; 163 bt_flip_addr(&event[2], channel->address); 164 bt_store_16(event, 8, channel->handle); 165 bt_store_16(event, 10, channel->psm); 166 bt_store_16(event, 12, channel->local_cid); 167 bt_store_16(event, 14, channel->remote_cid); 168 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 169 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 170 } 171 172 static void l2cap_emit_service_registered(void *connection, uint8_t status, uint16_t psm){ 173 log_info("L2CAP_EVENT_SERVICE_REGISTERED status 0x%x psm 0x%x", status, psm); 174 uint8_t event[5]; 175 event[0] = L2CAP_EVENT_SERVICE_REGISTERED; 176 event[1] = sizeof(event) - 2; 177 event[2] = status; 178 bt_store_16(event, 3, psm); 179 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 180 (*packet_handler)(connection, HCI_EVENT_PACKET, 0, event, sizeof(event)); 181 } 182 183 void l2cap_emit_credits(l2cap_channel_t *channel, uint8_t credits) { 184 185 log_info("L2CAP_EVENT_CREDITS local_cid 0x%x credits %u", channel->local_cid, credits); 186 // track credits 187 channel->packets_granted += credits; 188 189 uint8_t event[5]; 190 event[0] = L2CAP_EVENT_CREDITS; 191 event[1] = sizeof(event) - 2; 192 bt_store_16(event, 2, channel->local_cid); 193 event[4] = credits; 194 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 195 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 196 } 197 198 void l2cap_block_new_credits(uint8_t blocked){ 199 new_credits_blocked = blocked; 200 } 201 202 void l2cap_hand_out_credits(void){ 203 204 if (new_credits_blocked) return; // we're told not to. used by daemon 205 206 linked_item_t *it; 207 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 208 if (!hci_number_free_acl_slots()) return; 209 l2cap_channel_t * channel = (l2cap_channel_t *) it; 210 if (channel->state != L2CAP_STATE_OPEN) continue; 211 if (hci_number_outgoing_packets(channel->handle) < NR_BUFFERED_ACL_PACKETS && channel->packets_granted == 0) { 212 l2cap_emit_credits(channel, 1); 213 } 214 } 215 } 216 217 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 218 linked_item_t *it; 219 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 220 l2cap_channel_t * channel = (l2cap_channel_t *) it; 221 if ( channel->local_cid == local_cid) { 222 return channel; 223 } 224 } 225 return NULL; 226 } 227 228 int l2cap_can_send_packet_now(uint16_t local_cid){ 229 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 230 if (!channel) return 0; 231 if (!channel->packets_granted) return 0; 232 return hci_can_send_packet_now(HCI_ACL_DATA_PACKET); 233 } 234 235 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 236 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 237 if (channel) { 238 return channel->remote_mtu; 239 } 240 return 0; 241 } 242 243 static l2cap_channel_t * l2cap_channel_for_rtx_timer(timer_source_t * ts){ 244 linked_item_t *it; 245 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 246 l2cap_channel_t * channel = (l2cap_channel_t *) it; 247 if ( &channel->rtx == ts) { 248 return channel; 249 } 250 } 251 return NULL; 252 } 253 254 static void l2cap_rtx_timeout(timer_source_t * ts){ 255 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 256 if (!ts) return; 257 258 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 259 260 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 261 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 262 // notify client 263 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 264 265 // discard channel 266 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 267 btstack_memory_l2cap_channel_free(channel); 268 } 269 270 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 271 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 272 run_loop_remove_timer(&channel->rtx); 273 } 274 275 static void l2cap_start_rtx(l2cap_channel_t * channel){ 276 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 277 l2cap_stop_rtx(channel); 278 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 279 run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 280 run_loop_add_timer(&channel->rtx); 281 } 282 283 static void l2cap_start_ertx(l2cap_channel_t * channel){ 284 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 285 l2cap_stop_rtx(channel); 286 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 287 run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 288 run_loop_add_timer(&channel->rtx); 289 } 290 291 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 292 return psm != PSM_SDP; 293 } 294 295 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 296 297 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 298 log_info("l2cap_send_signaling_packet, cannot send\n"); 299 return BTSTACK_ACL_BUFFERS_FULL; 300 } 301 302 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 303 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 304 va_list argptr; 305 va_start(argptr, identifier); 306 uint16_t len = l2cap_create_signaling_internal(acl_buffer, handle, cmd, identifier, argptr); 307 va_end(argptr); 308 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 309 return hci_send_acl_packet(acl_buffer, len); 310 } 311 312 uint8_t *l2cap_get_outgoing_buffer(void){ 313 return hci_get_outgoing_acl_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 314 } 315 316 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 317 318 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 319 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", local_cid); 320 return BTSTACK_ACL_BUFFERS_FULL; 321 } 322 323 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 324 if (!channel) { 325 log_error("l2cap_send_internal no channel for cid 0x%02x\n", local_cid); 326 return -1; // TODO: define error 327 } 328 329 if (channel->packets_granted == 0){ 330 log_error("l2cap_send_internal cid 0x%02x, no credits!\n", local_cid); 331 return -1; // TODO: define error 332 } 333 334 --channel->packets_granted; 335 336 log_debug("l2cap_send_internal cid 0x%02x, handle %u, 1 credit used, credits left %u;\n", 337 local_cid, channel->handle, channel->packets_granted); 338 339 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 340 341 // 0 - Connection handle : PB=10 : BC=00 342 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 343 // 2 - ACL length 344 bt_store_16(acl_buffer, 2, len + 4); 345 // 4 - L2CAP packet length 346 bt_store_16(acl_buffer, 4, len + 0); 347 // 6 - L2CAP channel DEST 348 bt_store_16(acl_buffer, 6, channel->remote_cid); 349 // send 350 int err = hci_send_acl_packet(acl_buffer, len+8); 351 352 l2cap_hand_out_credits(); 353 354 return err; 355 } 356 357 int l2cap_send_prepared_connectionless(uint16_t handle, uint16_t cid, uint16_t len){ 358 359 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 360 log_info("l2cap_send_prepared_to_handle cid 0x%02x, cannot send\n", cid); 361 return BTSTACK_ACL_BUFFERS_FULL; 362 } 363 364 log_debug("l2cap_send_prepared_to_handle cid 0x%02x, handle %u\n", cid, handle); 365 366 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 367 368 // 0 - Connection handle : PB=10 : BC=00 369 bt_store_16(acl_buffer, 0, handle | (2 << 12) | (0 << 14)); 370 // 2 - ACL length 371 bt_store_16(acl_buffer, 2, len + 4); 372 // 4 - L2CAP packet length 373 bt_store_16(acl_buffer, 4, len + 0); 374 // 6 - L2CAP channel DEST 375 bt_store_16(acl_buffer, 6, cid); 376 // send 377 int err = hci_send_acl_packet(acl_buffer, len+8); 378 379 l2cap_hand_out_credits(); 380 381 return err; 382 } 383 384 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 385 386 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 387 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", local_cid); 388 return BTSTACK_ACL_BUFFERS_FULL; 389 } 390 391 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 392 393 memcpy(&acl_buffer[8], data, len); 394 395 return l2cap_send_prepared(local_cid, len); 396 } 397 398 int l2cap_send_connectionless(uint16_t handle, uint16_t cid, uint8_t *data, uint16_t len){ 399 400 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 401 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", cid); 402 return BTSTACK_ACL_BUFFERS_FULL; 403 } 404 405 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 406 407 memcpy(&acl_buffer[8], data, len); 408 409 return l2cap_send_prepared_connectionless(handle, cid, len); 410 } 411 412 int l2cap_send_echo_request(uint16_t handle, uint8_t *data, uint16_t len){ 413 return l2cap_send_signaling_packet(handle, ECHO_REQUEST, 0x77, len, data); 414 } 415 416 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 417 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 418 } 419 420 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 421 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 422 } 423 424 425 426 // MARK: L2CAP_RUN 427 // process outstanding signaling tasks 428 void l2cap_run(void){ 429 430 // check pending signaling responses 431 while (signaling_responses_pending){ 432 433 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)) break; 434 435 hci_con_handle_t handle = signaling_responses[0].handle; 436 uint8_t sig_id = signaling_responses[0].sig_id; 437 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 438 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 439 440 switch (signaling_responses[0].code){ 441 case CONNECTION_REQUEST: 442 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 443 // also disconnect if result is 0x0003 - security blocked 444 hci_disconnect_security_block(handle); 445 break; 446 case ECHO_REQUEST: 447 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 448 break; 449 case INFORMATION_REQUEST: 450 switch (infoType){ 451 case 1: { // Connectionless MTU 452 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 453 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 454 break; 455 } 456 case 2: { // Extended Features Supported 457 // extended features request supported, only supporing fixed channel map 458 uint32_t features = 0x80; 459 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 460 break; 461 } 462 case 3: { // Fixed Channels Supported 463 uint8_t map[8]; 464 memset(map, 0, 8); 465 map[0] = 0x01; // L2CAP Signaling Channel 466 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 467 break; 468 } 469 default: 470 // all other types are not supported 471 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 472 break; 473 } 474 break; 475 case COMMAND_REJECT: 476 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 477 break; 478 default: 479 // should not happen 480 break; 481 } 482 483 // remove first item 484 signaling_responses_pending--; 485 int i; 486 for (i=0; i < signaling_responses_pending; i++){ 487 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 488 } 489 } 490 491 uint8_t config_options[4]; 492 linked_item_t *it; 493 linked_item_t *next; 494 for (it = (linked_item_t *) l2cap_channels; it ; it = next){ 495 next = it->next; // cache next item as current item might get freed 496 497 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 498 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)) break; 499 500 l2cap_channel_t * channel = (l2cap_channel_t *) it; 501 502 // log_info("l2cap_run: state %u, var 0x%02x\n", channel->state, channel->state_var); 503 504 505 switch (channel->state){ 506 507 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 508 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 509 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 510 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 511 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 512 } 513 break; 514 515 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 516 // send connection request - set state first 517 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 518 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 519 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 520 break; 521 522 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 523 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 524 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 525 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); // -- remove from list 526 btstack_memory_l2cap_channel_free(channel); 527 break; 528 529 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 530 channel->state = L2CAP_STATE_CONFIG; 531 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 532 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 533 break; 534 535 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 536 // success, start l2cap handshake 537 channel->local_sig_id = l2cap_next_sig_id(); 538 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 539 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 540 l2cap_start_rtx(channel); 541 break; 542 543 case L2CAP_STATE_CONFIG: 544 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 545 uint16_t flags = 0; 546 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 547 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 548 flags = 1; 549 } else { 550 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 551 } 552 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 553 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 554 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 555 config_options[0] = 1; // MTU 556 config_options[1] = 2; // len param 557 bt_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 558 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 559 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 560 } else { 561 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 562 } 563 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 564 } 565 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 566 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 567 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 568 channel->local_sig_id = l2cap_next_sig_id(); 569 config_options[0] = 1; // MTU 570 config_options[1] = 2; // len param 571 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 572 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 573 l2cap_start_rtx(channel); 574 } 575 if (l2cap_channel_ready_for_open(channel)){ 576 channel->state = L2CAP_STATE_OPEN; 577 l2cap_emit_channel_opened(channel, 0); // success 578 l2cap_emit_credits(channel, 1); 579 } 580 break; 581 582 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 583 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 584 // 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 :) 585 l2cap_finialize_channel_close(channel); // -- remove from list 586 break; 587 588 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 589 channel->local_sig_id = l2cap_next_sig_id(); 590 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 591 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 592 break; 593 default: 594 break; 595 } 596 } 597 } 598 599 uint16_t l2cap_max_mtu(void){ 600 return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE; 601 } 602 603 static void l2cap_handle_connection_complete(uint16_t handle, l2cap_channel_t * channel){ 604 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 605 log_info("l2cap_handle_connection_complete expected state"); 606 // success, start l2cap handshake 607 channel->handle = handle; 608 channel->local_cid = l2cap_next_local_cid(); 609 // check remote SSP feature first 610 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 611 } 612 } 613 614 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 615 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 616 617 // we have been waiting for remote supported features, if both support SSP, 618 if (hci_ssp_supported_on_both_sides(channel->handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 619 // request security level 2 620 gap_request_security_level(channel->handle, LEVEL_2); 621 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 622 return; 623 } 624 // fine, go ahead 625 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 626 } 627 628 // open outgoing L2CAP channel 629 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 630 bd_addr_t address, uint16_t psm, uint16_t mtu){ 631 632 log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 633 634 // alloc structure 635 l2cap_channel_t * chan = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 636 if (!chan) { 637 // emit error event 638 l2cap_channel_t dummy_channel; 639 BD_ADDR_COPY(dummy_channel.address, address); 640 dummy_channel.psm = psm; 641 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 642 return; 643 } 644 // limit local mtu to max acl packet length 645 if (mtu > l2cap_max_mtu()) { 646 mtu = l2cap_max_mtu(); 647 } 648 649 // fill in 650 BD_ADDR_COPY(chan->address, address); 651 chan->psm = psm; 652 chan->handle = 0; 653 chan->connection = connection; 654 chan->packet_handler = packet_handler; 655 chan->remote_mtu = L2CAP_MINIMAL_MTU; 656 chan->local_mtu = mtu; 657 chan->packets_granted = 0; 658 659 // set initial state 660 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 661 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 662 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 663 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 664 chan->required_security_level = LEVEL_0; 665 666 // add to connections list 667 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 668 669 // check if hci connection is already usable 670 hci_connection_t * conn = hci_connection_for_bd_addr((bd_addr_t*)address); 671 if (conn){ 672 log_info("l2cap_create_channel_internal, hci connection already exists"); 673 l2cap_handle_connection_complete(conn->con_handle, chan); 674 // check ir remote supported fearures are already received 675 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 676 l2cap_handle_remote_supported_features_received(chan); 677 } 678 } 679 680 l2cap_run(); 681 } 682 683 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 684 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 685 // find channel for local_cid 686 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 687 if (channel) { 688 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 689 } 690 // process 691 l2cap_run(); 692 } 693 694 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 695 linked_item_t *it = (linked_item_t *) &l2cap_channels; 696 while (it->next){ 697 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 698 if ( ! BD_ADDR_CMP( channel->address, address) ){ 699 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 700 // failure, forward error code 701 l2cap_emit_channel_opened(channel, status); 702 // discard channel 703 it->next = it->next->next; 704 btstack_memory_l2cap_channel_free(channel); 705 } 706 } else { 707 it = it->next; 708 } 709 } 710 } 711 712 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 713 linked_item_t *it; 714 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 715 l2cap_channel_t * channel = (l2cap_channel_t *) it; 716 if ( ! BD_ADDR_CMP( channel->address, address) ){ 717 l2cap_handle_connection_complete(handle, channel); 718 } 719 } 720 // process 721 l2cap_run(); 722 } 723 724 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 725 726 bd_addr_t address; 727 hci_con_handle_t handle; 728 l2cap_channel_t * channel; 729 linked_item_t *it; 730 int hci_con_used; 731 732 switch(packet[0]){ 733 734 // handle connection complete events 735 case HCI_EVENT_CONNECTION_COMPLETE: 736 bt_flip_addr(address, &packet[5]); 737 if (packet[2] == 0){ 738 handle = READ_BT_16(packet, 3); 739 l2cap_handle_connection_success_for_addr(address, handle); 740 } else { 741 l2cap_handle_connection_failed_for_addr(address, packet[2]); 742 } 743 break; 744 745 // handle successful create connection cancel command 746 case HCI_EVENT_COMMAND_COMPLETE: 747 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 748 if (packet[5] == 0){ 749 bt_flip_addr(address, &packet[6]); 750 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 751 l2cap_handle_connection_failed_for_addr(address, 0x16); 752 } 753 } 754 l2cap_run(); // try sending signaling packets first 755 break; 756 757 case HCI_EVENT_COMMAND_STATUS: 758 l2cap_run(); // try sending signaling packets first 759 break; 760 761 // handle disconnection complete events 762 case HCI_EVENT_DISCONNECTION_COMPLETE: 763 // send l2cap disconnect events for all channels on this handle 764 handle = READ_BT_16(packet, 3); 765 it = (linked_item_t *) &l2cap_channels; 766 while (it->next){ 767 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 768 if ( channel->handle == handle ){ 769 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 770 it->next = it->next->next; 771 l2cap_emit_channel_closed(channel); 772 btstack_memory_l2cap_channel_free(channel); 773 } else { 774 it = it->next; 775 } 776 } 777 break; 778 779 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 780 l2cap_run(); // try sending signaling packets first 781 l2cap_hand_out_credits(); 782 break; 783 784 // HCI Connection Timeouts 785 case L2CAP_EVENT_TIMEOUT_CHECK: 786 handle = READ_BT_16(packet, 2); 787 if (hci_authentication_active_for_handle(handle)) break; 788 hci_con_used = 0; 789 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 790 channel = (l2cap_channel_t *) it; 791 if (channel->handle == handle) { 792 hci_con_used = 1; 793 } 794 } 795 if (hci_con_used) break; 796 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 797 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 798 break; 799 800 case DAEMON_EVENT_HCI_PACKET_SENT: 801 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 802 channel = (l2cap_channel_t *) it; 803 if (channel->packet_handler) { 804 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 805 } 806 } 807 if (attribute_protocol_packet_handler) { 808 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 809 } 810 if (security_protocol_packet_handler) { 811 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 812 } 813 break; 814 815 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 816 handle = READ_BT_16(packet, 3); 817 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 818 channel = (l2cap_channel_t *) it; 819 if (channel->handle != handle) continue; 820 l2cap_handle_remote_supported_features_received(channel); 821 break; 822 } 823 824 case GAP_SECURITY_LEVEL: 825 handle = READ_BT_16(packet, 2); 826 log_info("GAP_SECURITY_LEVEL"); 827 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 828 channel = (l2cap_channel_t *) it; 829 if (channel->handle != handle) continue; 830 831 gap_security_level_t actual_level = packet[4]; 832 gap_security_level_t required_level = channel->required_security_level; 833 log_info("gap outgoing - security level update %u, required %u", actual_level, required_level); 834 835 switch (channel->state){ 836 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 837 log_info("gap incoming"); 838 if (actual_level >= required_level){ 839 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 840 l2cap_emit_connection_request(channel); 841 } else { 842 channel->reason = 0x03; // security block 843 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 844 } 845 break; 846 847 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 848 if (actual_level >= required_level){ 849 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 850 } else { 851 // disconnnect, authentication not good enough 852 hci_disconnect_security_block(handle); 853 } 854 break; 855 856 default: 857 break; 858 } 859 } 860 break; 861 862 default: 863 break; 864 } 865 866 // pass on 867 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 868 } 869 870 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 871 channel->remote_sig_id = identifier; 872 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 873 l2cap_run(); 874 } 875 876 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 877 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 878 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 879 signaling_responses[signaling_responses_pending].handle = handle; 880 signaling_responses[signaling_responses_pending].code = code; 881 signaling_responses[signaling_responses_pending].sig_id = sig_id; 882 signaling_responses[signaling_responses_pending].data = data; 883 signaling_responses_pending++; 884 l2cap_run(); 885 } 886 } 887 888 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 889 890 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x\n", handle, psm, source_cid); 891 l2cap_service_t *service = l2cap_get_service(psm); 892 if (!service) { 893 // 0x0002 PSM not supported 894 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 895 return; 896 } 897 898 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 899 if (!hci_connection) { 900 // 901 log_error("no hci_connection for handle %u\n", handle); 902 return; 903 } 904 905 // reject connection (0x03 security block) and disconnect if both have SSP, connection is not encrypted and PSM != SDP 906 if ( l2cap_security_level_0_allowed_for_PSM(psm) 907 && hci_ssp_supported_on_both_sides(handle) 908 && gap_security_level(handle) == LEVEL_0){ 909 910 // 0x0003 Security Block 911 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0003); 912 return; 913 } 914 915 916 // alloc structure 917 // log_info("l2cap_handle_connection_request register channel\n"); 918 l2cap_channel_t * channel = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 919 if (!channel){ 920 // 0x0004 No resources available 921 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 922 return; 923 } 924 925 // fill in 926 BD_ADDR_COPY(channel->address, hci_connection->address); 927 channel->psm = psm; 928 channel->handle = handle; 929 channel->connection = service->connection; 930 channel->packet_handler = service->packet_handler; 931 channel->local_cid = l2cap_next_local_cid(); 932 channel->remote_cid = source_cid; 933 channel->local_mtu = service->mtu; 934 channel->remote_mtu = L2CAP_DEFAULT_MTU; 935 channel->packets_granted = 0; 936 channel->remote_sig_id = sig_id; 937 channel->required_security_level = service->required_security_level; 938 939 // limit local mtu to max acl packet length 940 if (channel->local_mtu > l2cap_max_mtu()) { 941 channel->local_mtu = l2cap_max_mtu(); 942 } 943 944 // set initial state 945 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 946 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 947 948 // add to connections list 949 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 950 951 // assert security requirements 952 gap_request_security_level(handle, channel->required_security_level); 953 } 954 955 void l2cap_accept_connection_internal(uint16_t local_cid){ 956 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 957 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 958 if (!channel) { 959 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 960 return; 961 } 962 963 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 964 965 // process 966 l2cap_run(); 967 } 968 969 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 970 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); 971 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 972 if (!channel) { 973 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 974 return; 975 } 976 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 977 channel->reason = reason; 978 l2cap_run(); 979 } 980 981 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 982 983 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 984 985 uint16_t flags = READ_BT_16(command, 6); 986 if (flags & 1) { 987 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 988 } 989 990 // accept the other's configuration options 991 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 992 uint16_t pos = 8; 993 while (pos < end_pos){ 994 uint8_t option_hint = command[pos] >> 7; 995 uint8_t option_type = command[pos] & 0x7f; 996 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 997 pos++; 998 uint8_t length = command[pos++]; 999 // MTU { type(8): 1, len(8):2, MTU(16) } 1000 if (option_type == 1 && length == 2){ 1001 channel->remote_mtu = READ_BT_16(command, pos); 1002 // log_info("l2cap cid 0x%02x, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 1003 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1004 } 1005 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1006 if (option_type == 2 && length == 2){ 1007 channel->flush_timeout = READ_BT_16(command, pos); 1008 } 1009 // check for unknown options 1010 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1011 log_info("l2cap cid %u, unknown options", channel->local_cid); 1012 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1013 } 1014 pos += length; 1015 } 1016 } 1017 1018 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1019 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 1020 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1021 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1022 return 1; 1023 } 1024 1025 1026 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1027 1028 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1029 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1030 uint16_t result = 0; 1031 1032 log_info("L2CAP signaling handler code %u, state %u\n", code, channel->state); 1033 1034 // handle DISCONNECT REQUESTS seperately 1035 if (code == DISCONNECTION_REQUEST){ 1036 switch (channel->state){ 1037 case L2CAP_STATE_CONFIG: 1038 case L2CAP_STATE_OPEN: 1039 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1040 case L2CAP_STATE_WAIT_DISCONNECT: 1041 l2cap_handle_disconnect_request(channel, identifier); 1042 break; 1043 1044 default: 1045 // ignore in other states 1046 break; 1047 } 1048 return; 1049 } 1050 1051 // @STATEMACHINE(l2cap) 1052 switch (channel->state) { 1053 1054 case L2CAP_STATE_WAIT_CONNECT_RSP: 1055 switch (code){ 1056 case CONNECTION_RESPONSE: 1057 l2cap_stop_rtx(channel); 1058 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1059 switch (result) { 1060 case 0: 1061 // successful connection 1062 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1063 channel->state = L2CAP_STATE_CONFIG; 1064 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1065 break; 1066 case 1: 1067 // connection pending. get some coffee, but start the ERTX 1068 l2cap_start_ertx(channel); 1069 break; 1070 default: 1071 // channel closed 1072 channel->state = L2CAP_STATE_CLOSED; 1073 // map l2cap connection response result to BTstack status enumeration 1074 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1075 1076 // drop link key if security block 1077 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1078 hci_drop_link_key_for_bd_addr(&channel->address); 1079 } 1080 1081 // discard channel 1082 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1083 btstack_memory_l2cap_channel_free(channel); 1084 break; 1085 } 1086 break; 1087 1088 default: 1089 //@TODO: implement other signaling packets 1090 break; 1091 } 1092 break; 1093 1094 case L2CAP_STATE_CONFIG: 1095 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1096 switch (code) { 1097 case CONFIGURE_REQUEST: 1098 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1099 l2cap_signaling_handle_configure_request(channel, command); 1100 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1101 // only done if continuation not set 1102 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1103 } 1104 break; 1105 case CONFIGURE_RESPONSE: 1106 l2cap_stop_rtx(channel); 1107 switch (result){ 1108 case 0: // success 1109 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1110 break; 1111 case 4: // pending 1112 l2cap_start_ertx(channel); 1113 break; 1114 default: 1115 // retry on negative result 1116 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1117 break; 1118 } 1119 break; 1120 default: 1121 break; 1122 } 1123 if (l2cap_channel_ready_for_open(channel)){ 1124 // for open: 1125 channel->state = L2CAP_STATE_OPEN; 1126 l2cap_emit_channel_opened(channel, 0); 1127 l2cap_emit_credits(channel, 1); 1128 } 1129 break; 1130 1131 case L2CAP_STATE_WAIT_DISCONNECT: 1132 switch (code) { 1133 case DISCONNECTION_RESPONSE: 1134 l2cap_finialize_channel_close(channel); 1135 break; 1136 default: 1137 //@TODO: implement other signaling packets 1138 break; 1139 } 1140 break; 1141 1142 case L2CAP_STATE_CLOSED: 1143 // @TODO handle incoming requests 1144 break; 1145 1146 case L2CAP_STATE_OPEN: 1147 //@TODO: implement other signaling packets, e.g. re-configure 1148 break; 1149 default: 1150 break; 1151 } 1152 // log_info("new state %u\n", channel->state); 1153 } 1154 1155 1156 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1157 1158 // get code, signalind identifier and command len 1159 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1160 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1161 1162 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1163 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1164 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1165 return; 1166 } 1167 1168 // general commands without an assigned channel 1169 switch(code) { 1170 1171 case CONNECTION_REQUEST: { 1172 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1173 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1174 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1175 return; 1176 } 1177 1178 case ECHO_REQUEST: 1179 l2cap_register_signaling_response(handle, code, sig_id, 0); 1180 return; 1181 1182 case INFORMATION_REQUEST: { 1183 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1184 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1185 return; 1186 } 1187 1188 default: 1189 break; 1190 } 1191 1192 1193 // Get potential destination CID 1194 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1195 1196 // Find channel for this sig_id and connection handle 1197 linked_item_t *it; 1198 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1199 l2cap_channel_t * channel = (l2cap_channel_t *) it; 1200 if (channel->handle == handle) { 1201 if (code & 1) { 1202 // match odd commands (responses) by previous signaling identifier 1203 if (channel->local_sig_id == sig_id) { 1204 l2cap_signaling_handler_channel(channel, command); 1205 break; 1206 } 1207 } else { 1208 // match even commands (requests) by local channel id 1209 if (channel->local_cid == dest_cid) { 1210 l2cap_signaling_handler_channel(channel, command); 1211 break; 1212 } 1213 } 1214 } 1215 } 1216 } 1217 1218 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 1219 1220 // Get Channel ID 1221 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1222 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1223 1224 switch (channel_id) { 1225 1226 case L2CAP_CID_SIGNALING: { 1227 1228 uint16_t command_offset = 8; 1229 while (command_offset < size) { 1230 1231 // handle signaling commands 1232 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1233 1234 // increment command_offset 1235 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1236 } 1237 break; 1238 } 1239 1240 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1241 if (attribute_protocol_packet_handler) { 1242 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1243 } 1244 break; 1245 1246 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1247 if (security_protocol_packet_handler) { 1248 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1249 } 1250 break; 1251 1252 default: { 1253 // Find channel for this channel_id and connection handle 1254 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1255 if (channel) { 1256 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1257 } 1258 break; 1259 } 1260 } 1261 } 1262 1263 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1264 switch (packet_type) { 1265 case HCI_EVENT_PACKET: 1266 l2cap_event_handler(packet, size); 1267 break; 1268 case HCI_ACL_DATA_PACKET: 1269 l2cap_acl_handler(packet, size); 1270 break; 1271 default: 1272 break; 1273 } 1274 l2cap_run(); 1275 } 1276 1277 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1278 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1279 channel->state = L2CAP_STATE_CLOSED; 1280 l2cap_emit_channel_closed(channel); 1281 // discard channel 1282 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1283 btstack_memory_l2cap_channel_free(channel); 1284 } 1285 1286 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1287 linked_item_t *it; 1288 1289 // close open channels 1290 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 1291 l2cap_service_t * service = ((l2cap_service_t *) it); 1292 if ( service->psm == psm){ 1293 return service; 1294 }; 1295 } 1296 return NULL; 1297 } 1298 1299 void l2cap_register_service_internal(void *connection, btstack_packet_handler_t packet_handler, uint16_t psm, uint16_t mtu, gap_security_level_t security_level){ 1300 1301 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1302 1303 // check for alread registered psm 1304 // TODO: emit error event 1305 l2cap_service_t *service = l2cap_get_service(psm); 1306 if (service) { 1307 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 1308 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1309 return; 1310 } 1311 1312 // alloc structure 1313 // TODO: emit error event 1314 service = (l2cap_service_t *) btstack_memory_l2cap_service_get(); 1315 if (!service) { 1316 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 1317 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1318 return; 1319 } 1320 1321 // fill in 1322 service->psm = psm; 1323 service->mtu = mtu; 1324 service->connection = connection; 1325 service->packet_handler = packet_handler; 1326 service->required_security_level = security_level; 1327 1328 // add to services list 1329 linked_list_add(&l2cap_services, (linked_item_t *) service); 1330 1331 // enable page scan 1332 hci_connectable_control(1); 1333 1334 // done 1335 l2cap_emit_service_registered(connection, 0, psm); 1336 } 1337 1338 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1339 1340 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1341 1342 l2cap_service_t *service = l2cap_get_service(psm); 1343 if (!service) return; 1344 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1345 btstack_memory_l2cap_service_free(service); 1346 1347 // disable page scan when no services registered 1348 if (!linked_list_empty(&l2cap_services)) return; 1349 hci_connectable_control(0); 1350 } 1351 1352 // 1353 void l2cap_close_connection(void *connection){ 1354 linked_item_t *it; 1355 1356 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 1357 l2cap_channel_t * channel; 1358 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1359 channel = (l2cap_channel_t *) it; 1360 if (channel->connection == connection) { 1361 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1362 } 1363 } 1364 1365 // unregister services 1366 it = (linked_item_t *) &l2cap_services; 1367 while (it->next) { 1368 l2cap_service_t * service = (l2cap_service_t *) it->next; 1369 if (service->connection == connection){ 1370 it->next = it->next->next; 1371 btstack_memory_l2cap_service_free(service); 1372 } else { 1373 it = it->next; 1374 } 1375 } 1376 1377 // process 1378 l2cap_run(); 1379 } 1380 1381 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1382 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1383 switch(channel_id){ 1384 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1385 attribute_protocol_packet_handler = packet_handler; 1386 break; 1387 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1388 security_protocol_packet_handler = packet_handler; 1389 break; 1390 } 1391 } 1392 1393 #ifdef HAVE_BLE 1394 // Request LE connection parameter update 1395 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){ 1396 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 1397 log_info("l2cap_send_signaling_packet, cannot send\n"); 1398 return BTSTACK_ACL_BUFFERS_FULL; 1399 } 1400 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 1401 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 1402 uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); 1403 return hci_send_acl_packet(acl_buffer, len); 1404 } 1405 #endif 1406 1407