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); 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 // open outgoing L2CAP channel 604 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 605 bd_addr_t address, uint16_t psm, uint16_t mtu){ 606 607 log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 608 609 // alloc structure 610 l2cap_channel_t * chan = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 611 if (!chan) { 612 // emit error event 613 l2cap_channel_t dummy_channel; 614 BD_ADDR_COPY(dummy_channel.address, address); 615 dummy_channel.psm = psm; 616 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 617 return; 618 } 619 // limit local mtu to max acl packet length 620 if (mtu > l2cap_max_mtu()) { 621 mtu = l2cap_max_mtu(); 622 } 623 624 // fill in 625 BD_ADDR_COPY(chan->address, address); 626 chan->psm = psm; 627 chan->handle = 0; 628 chan->connection = connection; 629 chan->packet_handler = packet_handler; 630 chan->remote_mtu = L2CAP_MINIMAL_MTU; 631 chan->local_mtu = mtu; 632 chan->packets_granted = 0; 633 634 // set initial state 635 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 636 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 637 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 638 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 639 640 // add to connections list 641 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 642 643 l2cap_run(); 644 } 645 646 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 647 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 648 // find channel for local_cid 649 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 650 if (channel) { 651 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 652 } 653 // process 654 l2cap_run(); 655 } 656 657 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 658 linked_item_t *it = (linked_item_t *) &l2cap_channels; 659 while (it->next){ 660 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 661 if ( ! BD_ADDR_CMP( channel->address, address) ){ 662 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 663 // failure, forward error code 664 l2cap_emit_channel_opened(channel, status); 665 // discard channel 666 it->next = it->next->next; 667 btstack_memory_l2cap_channel_free(channel); 668 } 669 } else { 670 it = it->next; 671 } 672 } 673 } 674 675 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 676 linked_item_t *it; 677 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 678 l2cap_channel_t * channel = (l2cap_channel_t *) it; 679 if ( ! BD_ADDR_CMP( channel->address, address) ){ 680 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 681 // success, start l2cap handshake 682 channel->handle = handle; 683 channel->local_cid = l2cap_next_local_cid(); 684 // check remote SSP feature first 685 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 686 } 687 } 688 } 689 // process 690 l2cap_run(); 691 } 692 693 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 694 695 bd_addr_t address; 696 hci_con_handle_t handle; 697 l2cap_channel_t * channel; 698 linked_item_t *it; 699 int hci_con_used; 700 701 switch(packet[0]){ 702 703 // handle connection complete events 704 case HCI_EVENT_CONNECTION_COMPLETE: 705 bt_flip_addr(address, &packet[5]); 706 if (packet[2] == 0){ 707 handle = READ_BT_16(packet, 3); 708 l2cap_handle_connection_success_for_addr(address, handle); 709 } else { 710 l2cap_handle_connection_failed_for_addr(address, packet[2]); 711 } 712 break; 713 714 // handle successful create connection cancel command 715 case HCI_EVENT_COMMAND_COMPLETE: 716 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 717 if (packet[5] == 0){ 718 bt_flip_addr(address, &packet[6]); 719 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 720 l2cap_handle_connection_failed_for_addr(address, 0x16); 721 } 722 } 723 l2cap_run(); // try sending signaling packets first 724 break; 725 726 case HCI_EVENT_COMMAND_STATUS: 727 l2cap_run(); // try sending signaling packets first 728 break; 729 730 // handle disconnection complete events 731 case HCI_EVENT_DISCONNECTION_COMPLETE: 732 // send l2cap disconnect events for all channels on this handle 733 handle = READ_BT_16(packet, 3); 734 it = (linked_item_t *) &l2cap_channels; 735 while (it->next){ 736 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 737 if ( channel->handle == handle ){ 738 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 739 it->next = it->next->next; 740 l2cap_emit_channel_closed(channel); 741 btstack_memory_l2cap_channel_free(channel); 742 } else { 743 it = it->next; 744 } 745 } 746 break; 747 748 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 749 l2cap_run(); // try sending signaling packets first 750 l2cap_hand_out_credits(); 751 break; 752 753 // HCI Connection Timeouts 754 case L2CAP_EVENT_TIMEOUT_CHECK: 755 handle = READ_BT_16(packet, 2); 756 if (hci_authentication_active_for_handle(handle)) break; 757 hci_con_used = 0; 758 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 759 channel = (l2cap_channel_t *) it; 760 if (channel->handle == handle) { 761 hci_con_used = 1; 762 } 763 } 764 if (hci_con_used) break; 765 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 766 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 767 break; 768 769 case DAEMON_EVENT_HCI_PACKET_SENT: 770 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 771 channel = (l2cap_channel_t *) it; 772 if (channel->packet_handler) { 773 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 774 } 775 } 776 if (attribute_protocol_packet_handler) { 777 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 778 } 779 if (security_protocol_packet_handler) { 780 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 781 } 782 break; 783 784 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 785 handle = READ_BT_16(packet, 3); 786 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 787 channel = (l2cap_channel_t *) it; 788 if (channel->handle != handle) continue; 789 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) continue; 790 // we have been waiting for remote supported features, if both support SSP, 791 if (hci_ssp_supported_on_both_sides(channel->handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 792 // request security level 2 793 gap_request_security_level(channel->handle, LEVEL_2); 794 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 795 break; 796 } 797 // fine, go ahead 798 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 799 break; 800 } 801 802 case GAP_SECURITY_LEVEL: 803 handle = READ_BT_16(packet, 2); 804 log_info("GAP_SECURITY_LEVEL"); 805 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 806 channel = (l2cap_channel_t *) it; 807 gap_security_level_t actual_level = packet[4]; 808 if (channel->handle != handle) continue; 809 switch (channel->state){ 810 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 811 log_info("gap incoming"); 812 if (actual_level >= channel->required_security_level){ 813 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 814 l2cap_emit_connection_request(channel); 815 } else { 816 channel->reason = 0x03; // security block 817 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 818 } 819 break; 820 821 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 822 log_info("gap outgoing"); 823 if (actual_level >= channel->required_security_level){ 824 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 825 } else { 826 // disconnnect, authentication not good enough 827 hci_disconnect_security_block(handle); 828 } 829 break; 830 831 default: 832 break; 833 } 834 } 835 break; 836 837 default: 838 break; 839 } 840 841 // pass on 842 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 843 } 844 845 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 846 channel->remote_sig_id = identifier; 847 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 848 l2cap_run(); 849 } 850 851 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 852 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 853 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 854 signaling_responses[signaling_responses_pending].handle = handle; 855 signaling_responses[signaling_responses_pending].code = code; 856 signaling_responses[signaling_responses_pending].sig_id = sig_id; 857 signaling_responses[signaling_responses_pending].data = data; 858 signaling_responses_pending++; 859 l2cap_run(); 860 } 861 } 862 863 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 864 865 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x\n", handle, psm, source_cid); 866 l2cap_service_t *service = l2cap_get_service(psm); 867 if (!service) { 868 // 0x0002 PSM not supported 869 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 870 return; 871 } 872 873 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 874 if (!hci_connection) { 875 // 876 log_error("no hci_connection for handle %u\n", handle); 877 return; 878 } 879 880 // reject connection (0x03 security block) and disconnect if both have SSP, connection is not encrypted and PSM != SDP 881 if ( l2cap_security_level_0_allowed_for_PSM(psm) 882 && hci_ssp_supported_on_both_sides(handle) 883 && gap_security_level(handle) == LEVEL_0){ 884 885 // 0x0003 Security Block 886 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0003); 887 return; 888 } 889 890 891 // alloc structure 892 // log_info("l2cap_handle_connection_request register channel\n"); 893 l2cap_channel_t * channel = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 894 if (!channel){ 895 // 0x0004 No resources available 896 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 897 return; 898 } 899 900 // fill in 901 BD_ADDR_COPY(channel->address, hci_connection->address); 902 channel->psm = psm; 903 channel->handle = handle; 904 channel->connection = service->connection; 905 channel->packet_handler = service->packet_handler; 906 channel->local_cid = l2cap_next_local_cid(); 907 channel->remote_cid = source_cid; 908 channel->local_mtu = service->mtu; 909 channel->remote_mtu = L2CAP_DEFAULT_MTU; 910 channel->packets_granted = 0; 911 channel->remote_sig_id = sig_id; 912 channel->required_security_level = service->required_security_level; 913 914 // limit local mtu to max acl packet length 915 if (channel->local_mtu > l2cap_max_mtu()) { 916 channel->local_mtu = l2cap_max_mtu(); 917 } 918 919 // set initial state 920 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 921 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 922 923 // add to connections list 924 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 925 926 // assert security requirements 927 gap_request_security_level(handle, channel->required_security_level); 928 } 929 930 void l2cap_accept_connection_internal(uint16_t local_cid){ 931 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 932 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 933 if (!channel) { 934 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 935 return; 936 } 937 938 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 939 940 // process 941 l2cap_run(); 942 } 943 944 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 945 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); 946 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 947 if (!channel) { 948 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 949 return; 950 } 951 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 952 channel->reason = reason; 953 l2cap_run(); 954 } 955 956 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 957 958 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 959 960 uint16_t flags = READ_BT_16(command, 6); 961 if (flags & 1) { 962 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 963 } 964 965 // accept the other's configuration options 966 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 967 uint16_t pos = 8; 968 while (pos < end_pos){ 969 uint8_t option_hint = command[pos] >> 7; 970 uint8_t option_type = command[pos] & 0x7f; 971 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 972 pos++; 973 uint8_t length = command[pos++]; 974 // MTU { type(8): 1, len(8):2, MTU(16) } 975 if (option_type == 1 && length == 2){ 976 channel->remote_mtu = READ_BT_16(command, pos); 977 // log_info("l2cap cid 0x%02x, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 978 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 979 } 980 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 981 if (option_type == 2 && length == 2){ 982 channel->flush_timeout = READ_BT_16(command, pos); 983 } 984 // check for unknown options 985 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 986 log_info("l2cap cid %u, unknown options", channel->local_cid); 987 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 988 } 989 pos += length; 990 } 991 } 992 993 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 994 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 995 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 996 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 997 return 1; 998 } 999 1000 1001 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1002 1003 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1004 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1005 uint16_t result = 0; 1006 1007 log_info("L2CAP signaling handler code %u, state %u\n", code, channel->state); 1008 1009 // handle DISCONNECT REQUESTS seperately 1010 if (code == DISCONNECTION_REQUEST){ 1011 switch (channel->state){ 1012 case L2CAP_STATE_CONFIG: 1013 case L2CAP_STATE_OPEN: 1014 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1015 case L2CAP_STATE_WAIT_DISCONNECT: 1016 l2cap_handle_disconnect_request(channel, identifier); 1017 break; 1018 1019 default: 1020 // ignore in other states 1021 break; 1022 } 1023 return; 1024 } 1025 1026 // @STATEMACHINE(l2cap) 1027 switch (channel->state) { 1028 1029 case L2CAP_STATE_WAIT_CONNECT_RSP: 1030 switch (code){ 1031 case CONNECTION_RESPONSE: 1032 l2cap_stop_rtx(channel); 1033 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1034 switch (result) { 1035 case 0: 1036 // successful connection 1037 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1038 channel->state = L2CAP_STATE_CONFIG; 1039 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1040 break; 1041 case 1: 1042 // connection pending. get some coffee, but start the ERTX 1043 l2cap_start_ertx(channel); 1044 break; 1045 default: 1046 // channel closed 1047 channel->state = L2CAP_STATE_CLOSED; 1048 // map l2cap connection response result to BTstack status enumeration 1049 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1050 1051 // drop link key if security block 1052 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1053 hci_drop_link_key_for_bd_addr(&channel->address); 1054 } 1055 1056 // discard channel 1057 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1058 btstack_memory_l2cap_channel_free(channel); 1059 break; 1060 } 1061 break; 1062 1063 default: 1064 //@TODO: implement other signaling packets 1065 break; 1066 } 1067 break; 1068 1069 case L2CAP_STATE_CONFIG: 1070 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1071 switch (code) { 1072 case CONFIGURE_REQUEST: 1073 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1074 l2cap_signaling_handle_configure_request(channel, command); 1075 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1076 // only done if continuation not set 1077 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1078 } 1079 break; 1080 case CONFIGURE_RESPONSE: 1081 l2cap_stop_rtx(channel); 1082 switch (result){ 1083 case 0: // success 1084 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1085 break; 1086 case 4: // pending 1087 l2cap_start_ertx(channel); 1088 break; 1089 default: 1090 // retry on negative result 1091 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1092 break; 1093 } 1094 break; 1095 default: 1096 break; 1097 } 1098 if (l2cap_channel_ready_for_open(channel)){ 1099 // for open: 1100 channel->state = L2CAP_STATE_OPEN; 1101 l2cap_emit_channel_opened(channel, 0); 1102 l2cap_emit_credits(channel, 1); 1103 } 1104 break; 1105 1106 case L2CAP_STATE_WAIT_DISCONNECT: 1107 switch (code) { 1108 case DISCONNECTION_RESPONSE: 1109 l2cap_finialize_channel_close(channel); 1110 break; 1111 default: 1112 //@TODO: implement other signaling packets 1113 break; 1114 } 1115 break; 1116 1117 case L2CAP_STATE_CLOSED: 1118 // @TODO handle incoming requests 1119 break; 1120 1121 case L2CAP_STATE_OPEN: 1122 //@TODO: implement other signaling packets, e.g. re-configure 1123 break; 1124 default: 1125 break; 1126 } 1127 // log_info("new state %u\n", channel->state); 1128 } 1129 1130 1131 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1132 1133 // get code, signalind identifier and command len 1134 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1135 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1136 1137 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1138 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1139 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1140 return; 1141 } 1142 1143 // general commands without an assigned channel 1144 switch(code) { 1145 1146 case CONNECTION_REQUEST: { 1147 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1148 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1149 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1150 return; 1151 } 1152 1153 case ECHO_REQUEST: 1154 l2cap_register_signaling_response(handle, code, sig_id, 0); 1155 return; 1156 1157 case INFORMATION_REQUEST: { 1158 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1159 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1160 return; 1161 } 1162 1163 default: 1164 break; 1165 } 1166 1167 1168 // Get potential destination CID 1169 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1170 1171 // Find channel for this sig_id and connection handle 1172 linked_item_t *it; 1173 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1174 l2cap_channel_t * channel = (l2cap_channel_t *) it; 1175 if (channel->handle == handle) { 1176 if (code & 1) { 1177 // match odd commands (responses) by previous signaling identifier 1178 if (channel->local_sig_id == sig_id) { 1179 l2cap_signaling_handler_channel(channel, command); 1180 break; 1181 } 1182 } else { 1183 // match even commands (requests) by local channel id 1184 if (channel->local_cid == dest_cid) { 1185 l2cap_signaling_handler_channel(channel, command); 1186 break; 1187 } 1188 } 1189 } 1190 } 1191 } 1192 1193 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 1194 1195 // Get Channel ID 1196 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1197 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1198 1199 switch (channel_id) { 1200 1201 case L2CAP_CID_SIGNALING: { 1202 1203 uint16_t command_offset = 8; 1204 while (command_offset < size) { 1205 1206 // handle signaling commands 1207 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1208 1209 // increment command_offset 1210 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1211 } 1212 break; 1213 } 1214 1215 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1216 if (attribute_protocol_packet_handler) { 1217 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1218 } 1219 break; 1220 1221 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1222 if (security_protocol_packet_handler) { 1223 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1224 } 1225 break; 1226 1227 default: { 1228 // Find channel for this channel_id and connection handle 1229 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1230 if (channel) { 1231 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1232 } 1233 break; 1234 } 1235 } 1236 } 1237 1238 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1239 switch (packet_type) { 1240 case HCI_EVENT_PACKET: 1241 l2cap_event_handler(packet, size); 1242 break; 1243 case HCI_ACL_DATA_PACKET: 1244 l2cap_acl_handler(packet, size); 1245 break; 1246 default: 1247 break; 1248 } 1249 l2cap_run(); 1250 } 1251 1252 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1253 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1254 channel->state = L2CAP_STATE_CLOSED; 1255 l2cap_emit_channel_closed(channel); 1256 // discard channel 1257 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1258 btstack_memory_l2cap_channel_free(channel); 1259 } 1260 1261 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1262 linked_item_t *it; 1263 1264 // close open channels 1265 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 1266 l2cap_service_t * service = ((l2cap_service_t *) it); 1267 if ( service->psm == psm){ 1268 return service; 1269 }; 1270 } 1271 return NULL; 1272 } 1273 1274 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){ 1275 1276 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1277 1278 // check for alread registered psm 1279 // TODO: emit error event 1280 l2cap_service_t *service = l2cap_get_service(psm); 1281 if (service) { 1282 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 1283 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1284 return; 1285 } 1286 1287 // alloc structure 1288 // TODO: emit error event 1289 service = (l2cap_service_t *) btstack_memory_l2cap_service_get(); 1290 if (!service) { 1291 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 1292 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1293 return; 1294 } 1295 1296 // fill in 1297 service->psm = psm; 1298 service->mtu = mtu; 1299 service->connection = connection; 1300 service->packet_handler = packet_handler; 1301 service->required_security_level = security_level; 1302 1303 // add to services list 1304 linked_list_add(&l2cap_services, (linked_item_t *) service); 1305 1306 // enable page scan 1307 hci_connectable_control(1); 1308 1309 // done 1310 l2cap_emit_service_registered(connection, 0, psm); 1311 } 1312 1313 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1314 1315 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1316 1317 l2cap_service_t *service = l2cap_get_service(psm); 1318 if (!service) return; 1319 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1320 btstack_memory_l2cap_service_free(service); 1321 1322 // disable page scan when no services registered 1323 if (!linked_list_empty(&l2cap_services)) return; 1324 hci_connectable_control(0); 1325 } 1326 1327 // 1328 void l2cap_close_connection(void *connection){ 1329 linked_item_t *it; 1330 1331 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 1332 l2cap_channel_t * channel; 1333 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1334 channel = (l2cap_channel_t *) it; 1335 if (channel->connection == connection) { 1336 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1337 } 1338 } 1339 1340 // unregister services 1341 it = (linked_item_t *) &l2cap_services; 1342 while (it->next) { 1343 l2cap_service_t * service = (l2cap_service_t *) it->next; 1344 if (service->connection == connection){ 1345 it->next = it->next->next; 1346 btstack_memory_l2cap_service_free(service); 1347 } else { 1348 it = it->next; 1349 } 1350 } 1351 1352 // process 1353 l2cap_run(); 1354 } 1355 1356 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1357 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1358 switch(channel_id){ 1359 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1360 attribute_protocol_packet_handler = packet_handler; 1361 break; 1362 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1363 security_protocol_packet_handler = packet_handler; 1364 break; 1365 } 1366 } 1367 1368 #ifdef HAVE_BLE 1369 // Request LE connection parameter update 1370 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){ 1371 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 1372 log_info("l2cap_send_signaling_packet, cannot send\n"); 1373 return BTSTACK_ACL_BUFFERS_FULL; 1374 } 1375 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 1376 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 1377 uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); 1378 return hci_send_acl_packet(acl_buffer, len); 1379 } 1380 #endif 1381 1382