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 static uint8_t require_security_level2_for_outgoing_sdp; 83 84 // prototypes 85 static void l2cap_finialize_channel_close(l2cap_channel_t *channel); 86 static l2cap_service_t * l2cap_get_service(uint16_t psm); 87 static void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status); 88 static void l2cap_emit_channel_closed(l2cap_channel_t *channel); 89 static void l2cap_emit_connection_request(l2cap_channel_t *channel); 90 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); 91 92 93 void l2cap_init(){ 94 new_credits_blocked = 0; 95 signaling_responses_pending = 0; 96 97 l2cap_channels = NULL; 98 l2cap_services = NULL; 99 100 packet_handler = null_packet_handler; 101 attribute_protocol_packet_handler = NULL; 102 security_protocol_packet_handler = NULL; 103 104 require_security_level2_for_outgoing_sdp = 0; 105 106 // 107 // register callback with HCI 108 // 109 hci_register_packet_handler(&l2cap_packet_handler); 110 hci_connectable_control(0); // no services yet 111 } 112 113 114 /** Register L2CAP packet handlers */ 115 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 116 } 117 void l2cap_register_packet_handler(void (*handler)(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 118 packet_handler = handler; 119 } 120 121 // notify client/protocol handler 122 void l2cap_dispatch(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 123 if (channel->packet_handler) { 124 (* (channel->packet_handler))(type, channel->local_cid, data, size); 125 } else { 126 (*packet_handler)(channel->connection, type, channel->local_cid, data, size); 127 } 128 } 129 130 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 131 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", 132 status, bd_addr_to_str(channel->address), channel->handle, channel->psm, 133 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 134 uint8_t event[23]; 135 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 136 event[1] = sizeof(event) - 2; 137 event[2] = status; 138 bt_flip_addr(&event[3], channel->address); 139 bt_store_16(event, 9, channel->handle); 140 bt_store_16(event, 11, channel->psm); 141 bt_store_16(event, 13, channel->local_cid); 142 bt_store_16(event, 15, channel->remote_cid); 143 bt_store_16(event, 17, channel->local_mtu); 144 bt_store_16(event, 19, channel->remote_mtu); 145 bt_store_16(event, 21, channel->flush_timeout); 146 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 147 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 148 } 149 150 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 151 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 152 uint8_t event[4]; 153 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 154 event[1] = sizeof(event) - 2; 155 bt_store_16(event, 2, channel->local_cid); 156 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 157 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 158 } 159 160 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 161 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 162 bd_addr_to_str(channel->address), channel->handle, channel->psm, channel->local_cid, channel->remote_cid); 163 uint8_t event[16]; 164 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 165 event[1] = sizeof(event) - 2; 166 bt_flip_addr(&event[2], channel->address); 167 bt_store_16(event, 8, channel->handle); 168 bt_store_16(event, 10, channel->psm); 169 bt_store_16(event, 12, channel->local_cid); 170 bt_store_16(event, 14, channel->remote_cid); 171 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 172 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 173 } 174 175 void l2cap_emit_connection_parameter_update_response(uint16_t handle, uint16_t result){ 176 uint8_t event[6]; 177 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_RESPONSE; 178 event[1] = 4; 179 bt_store_16(event, 2, handle); 180 bt_store_16(event, 4, result); 181 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 182 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, event, sizeof(event)); 183 } 184 185 static void l2cap_emit_service_registered(void *connection, uint8_t status, uint16_t psm){ 186 log_info("L2CAP_EVENT_SERVICE_REGISTERED status 0x%x psm 0x%x", status, psm); 187 uint8_t event[5]; 188 event[0] = L2CAP_EVENT_SERVICE_REGISTERED; 189 event[1] = sizeof(event) - 2; 190 event[2] = status; 191 bt_store_16(event, 3, psm); 192 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 193 (*packet_handler)(connection, HCI_EVENT_PACKET, 0, event, sizeof(event)); 194 } 195 196 void l2cap_emit_credits(l2cap_channel_t *channel, uint8_t credits) { 197 198 log_info("L2CAP_EVENT_CREDITS local_cid 0x%x credits %u", channel->local_cid, credits); 199 // track credits 200 channel->packets_granted += credits; 201 202 uint8_t event[5]; 203 event[0] = L2CAP_EVENT_CREDITS; 204 event[1] = sizeof(event) - 2; 205 bt_store_16(event, 2, channel->local_cid); 206 event[4] = credits; 207 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 208 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 209 } 210 211 void l2cap_block_new_credits(uint8_t blocked){ 212 new_credits_blocked = blocked; 213 } 214 215 void l2cap_hand_out_credits(void){ 216 217 if (new_credits_blocked) return; // we're told not to. used by daemon 218 219 linked_list_iterator_t it; 220 linked_list_iterator_init(&it, &l2cap_channels); 221 while (linked_list_iterator_has_next(&it)){ 222 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 223 if (!hci_number_free_acl_slots_for_handle(channel->handle)) return; 224 if (channel->state != L2CAP_STATE_OPEN) continue; 225 if (hci_number_outgoing_packets(channel->handle) < NR_BUFFERED_ACL_PACKETS && channel->packets_granted == 0) { 226 l2cap_emit_credits(channel, 1); 227 } 228 } 229 } 230 231 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 232 linked_list_iterator_t it; 233 linked_list_iterator_init(&it, &l2cap_channels); 234 while (linked_list_iterator_has_next(&it)){ 235 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 236 if ( channel->local_cid == local_cid) { 237 return channel; 238 } 239 } 240 return NULL; 241 } 242 243 int l2cap_can_send_packet_now(uint16_t local_cid){ 244 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 245 if (!channel) return 0; 246 if (!channel->packets_granted) return 0; 247 return hci_can_send_acl_packet_now(channel->handle); 248 } 249 250 // @deprecated 251 int l2cap_can_send_connectionless_packet_now(void){ 252 // TODO provide real handle 253 return l2cap_can_send_fixed_channel_packet_now(0x1234); 254 } 255 256 int l2cap_can_send_fixed_channel_packet_now(uint16_t handle){ 257 return hci_can_send_acl_packet_now(handle); 258 } 259 260 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 261 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 262 if (channel) { 263 return channel->remote_mtu; 264 } 265 return 0; 266 } 267 268 static l2cap_channel_t * l2cap_channel_for_rtx_timer(timer_source_t * ts){ 269 linked_list_iterator_t it; 270 linked_list_iterator_init(&it, &l2cap_channels); 271 while (linked_list_iterator_has_next(&it)){ 272 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 273 if ( &channel->rtx == ts) { 274 return channel; 275 } 276 } 277 return NULL; 278 } 279 280 static void l2cap_rtx_timeout(timer_source_t * ts){ 281 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 282 if (!ts) return; 283 284 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 285 286 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 287 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 288 // notify client 289 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 290 291 // discard channel 292 // no need to stop timer here, it is removed from list during timer callback 293 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 294 btstack_memory_l2cap_channel_free(channel); 295 } 296 297 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 298 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 299 run_loop_remove_timer(&channel->rtx); 300 } 301 302 static void l2cap_start_rtx(l2cap_channel_t * channel){ 303 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 304 l2cap_stop_rtx(channel); 305 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 306 run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 307 run_loop_add_timer(&channel->rtx); 308 } 309 310 static void l2cap_start_ertx(l2cap_channel_t * channel){ 311 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 312 l2cap_stop_rtx(channel); 313 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 314 run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 315 run_loop_add_timer(&channel->rtx); 316 } 317 318 void l2cap_require_security_level_2_for_outgoing_sdp(){ 319 require_security_level2_for_outgoing_sdp = 1; 320 } 321 322 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 323 return (psm == PSM_SDP) && (!require_security_level2_for_outgoing_sdp); 324 } 325 326 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 327 328 if (!hci_can_send_acl_packet_now(handle)){ 329 log_info("l2cap_send_signaling_packet, cannot send"); 330 return BTSTACK_ACL_BUFFERS_FULL; 331 } 332 333 // log_info("l2cap_send_signaling_packet type %u", cmd); 334 hci_reserve_packet_buffer(); 335 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 336 va_list argptr; 337 va_start(argptr, identifier); 338 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 339 va_end(argptr); 340 // log_info("l2cap_send_signaling_packet con %u!", handle); 341 return hci_send_acl_packet_buffer(len); 342 } 343 344 #ifdef HAVE_BLE 345 int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 346 347 if (!hci_can_send_acl_packet_now(handle)){ 348 log_info("l2cap_send_signaling_packet, cannot send"); 349 return BTSTACK_ACL_BUFFERS_FULL; 350 } 351 352 // log_info("l2cap_send_signaling_packet type %u", cmd); 353 hci_reserve_packet_buffer(); 354 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 355 va_list argptr; 356 va_start(argptr, identifier); 357 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 358 va_end(argptr); 359 // log_info("l2cap_send_signaling_packet con %u!", handle); 360 return hci_send_acl_packet_buffer(len); 361 } 362 #endif 363 364 uint8_t *l2cap_get_outgoing_buffer(void){ 365 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 366 } 367 368 int l2cap_reserve_packet_buffer(void){ 369 return hci_reserve_packet_buffer(); 370 } 371 372 void l2cap_release_packet_buffer(void){ 373 hci_release_packet_buffer(); 374 } 375 376 377 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 378 379 if (!hci_is_packet_buffer_reserved()){ 380 log_error("l2cap_send_prepared called without reserving packet first"); 381 return BTSTACK_ACL_BUFFERS_FULL; 382 } 383 384 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 385 if (!channel) { 386 log_error("l2cap_send_prepared no channel for cid 0x%02x", local_cid); 387 return -1; // TODO: define error 388 } 389 390 if (channel->packets_granted == 0){ 391 log_error("l2cap_send_prepared cid 0x%02x, no credits!", local_cid); 392 return -1; // TODO: define error 393 } 394 395 if (!hci_can_send_prepared_acl_packet_now(channel->handle)){ 396 log_info("l2cap_send_prepared cid 0x%02x, cannot send", local_cid); 397 return BTSTACK_ACL_BUFFERS_FULL; 398 } 399 400 --channel->packets_granted; 401 402 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used, credits left %u;", 403 local_cid, channel->handle, channel->packets_granted); 404 405 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 406 407 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 408 409 // 0 - Connection handle : PB=pb : BC=00 410 bt_store_16(acl_buffer, 0, channel->handle | (pb << 12) | (0 << 14)); 411 // 2 - ACL length 412 bt_store_16(acl_buffer, 2, len + 4); 413 // 4 - L2CAP packet length 414 bt_store_16(acl_buffer, 4, len + 0); 415 // 6 - L2CAP channel DEST 416 bt_store_16(acl_buffer, 6, channel->remote_cid); 417 // send 418 int err = hci_send_acl_packet_buffer(len+8); 419 420 l2cap_hand_out_credits(); 421 422 return err; 423 } 424 425 int l2cap_send_prepared_connectionless(uint16_t handle, uint16_t cid, uint16_t len){ 426 427 if (!hci_is_packet_buffer_reserved()){ 428 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 429 return BTSTACK_ACL_BUFFERS_FULL; 430 } 431 432 if (!hci_can_send_prepared_acl_packet_now(handle)){ 433 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send", handle, cid); 434 return BTSTACK_ACL_BUFFERS_FULL; 435 } 436 437 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x", handle, cid); 438 439 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 440 441 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 442 443 // 0 - Connection handle : PB=pb : BC=00 444 bt_store_16(acl_buffer, 0, handle | (pb << 12) | (0 << 14)); 445 // 2 - ACL length 446 bt_store_16(acl_buffer, 2, len + 4); 447 // 4 - L2CAP packet length 448 bt_store_16(acl_buffer, 4, len + 0); 449 // 6 - L2CAP channel DEST 450 bt_store_16(acl_buffer, 6, cid); 451 // send 452 int err = hci_send_acl_packet_buffer(len+8); 453 454 l2cap_hand_out_credits(); 455 456 return err; 457 } 458 459 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 460 461 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 462 if (!channel) { 463 log_error("l2cap_send_internal no channel for cid 0x%02x", local_cid); 464 return -1; // TODO: define error 465 } 466 467 if (len > channel->remote_mtu){ 468 log_error("l2cap_send_internal cid 0x%02x, data length exceeds remote MTU.", local_cid); 469 return L2CAP_DATA_LEN_EXCEEDS_REMOTE_MTU; 470 } 471 472 if (!hci_can_send_acl_packet_now(channel->handle)){ 473 log_info("l2cap_send_internal cid 0x%02x, cannot send", local_cid); 474 return BTSTACK_ACL_BUFFERS_FULL; 475 } 476 477 hci_reserve_packet_buffer(); 478 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 479 480 memcpy(&acl_buffer[8], data, len); 481 482 return l2cap_send_prepared(local_cid, len); 483 } 484 485 int l2cap_send_connectionless(uint16_t handle, uint16_t cid, uint8_t *data, uint16_t len){ 486 487 if (!hci_can_send_acl_packet_now(handle)){ 488 log_info("l2cap_send_internal cid 0x%02x, cannot send", cid); 489 return BTSTACK_ACL_BUFFERS_FULL; 490 } 491 492 hci_reserve_packet_buffer(); 493 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 494 495 memcpy(&acl_buffer[8], data, len); 496 497 return l2cap_send_prepared_connectionless(handle, cid, len); 498 } 499 500 int l2cap_send_echo_request(uint16_t handle, uint8_t *data, uint16_t len){ 501 return l2cap_send_signaling_packet(handle, ECHO_REQUEST, 0x77, len, data); 502 } 503 504 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 505 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 506 } 507 508 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 509 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 510 } 511 512 513 514 // MARK: L2CAP_RUN 515 // process outstanding signaling tasks 516 void l2cap_run(void){ 517 518 // check pending signaling responses 519 while (signaling_responses_pending){ 520 521 hci_con_handle_t handle = signaling_responses[0].handle; 522 523 if (!hci_can_send_acl_packet_now(handle)) break; 524 525 uint8_t sig_id = signaling_responses[0].sig_id; 526 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 527 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 528 529 switch (signaling_responses[0].code){ 530 case CONNECTION_REQUEST: 531 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 532 // also disconnect if result is 0x0003 - security blocked 533 if (result == 0x0003){ 534 hci_disconnect_security_block(handle); 535 } 536 break; 537 case ECHO_REQUEST: 538 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 539 break; 540 case INFORMATION_REQUEST: 541 switch (infoType){ 542 case 1: { // Connectionless MTU 543 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 544 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 545 break; 546 } 547 case 2: { // Extended Features Supported 548 // extended features request supported, only supporing fixed channel map 549 uint32_t features = 0x80; 550 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 551 break; 552 } 553 case 3: { // Fixed Channels Supported 554 uint8_t map[8]; 555 memset(map, 0, 8); 556 map[0] = 0x01; // L2CAP Signaling Channel 557 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 558 break; 559 } 560 default: 561 // all other types are not supported 562 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 563 break; 564 } 565 break; 566 case COMMAND_REJECT: 567 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 568 #ifdef HAVE_BLE 569 case COMMAND_REJECT_LE: 570 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 571 break; 572 #endif 573 default: 574 // should not happen 575 break; 576 } 577 578 // remove first item 579 signaling_responses_pending--; 580 int i; 581 for (i=0; i < signaling_responses_pending; i++){ 582 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 583 } 584 } 585 586 uint8_t config_options[4]; 587 linked_list_iterator_t it; 588 linked_list_iterator_init(&it, &l2cap_channels); 589 while (linked_list_iterator_has_next(&it)){ 590 591 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 592 // log_info("l2cap_run: state %u, var 0x%02x", channel->state, channel->state_var); 593 switch (channel->state){ 594 595 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 596 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 597 if (!hci_can_send_acl_packet_now(channel->handle)) break; 598 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 599 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 600 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 601 } 602 break; 603 604 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 605 if (!hci_can_send_command_packet_now()) break; 606 // send connection request - set state first 607 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 608 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 609 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 610 break; 611 612 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 613 if (!hci_can_send_acl_packet_now(channel->handle)) break; 614 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 615 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 616 l2cap_stop_rtx(channel); 617 linked_list_iterator_remove(&it); 618 btstack_memory_l2cap_channel_free(channel); 619 break; 620 621 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 622 if (!hci_can_send_acl_packet_now(channel->handle)) break; 623 channel->state = L2CAP_STATE_CONFIG; 624 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 625 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 626 break; 627 628 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 629 if (!hci_can_send_acl_packet_now(channel->handle)) break; 630 // success, start l2cap handshake 631 channel->local_sig_id = l2cap_next_sig_id(); 632 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 633 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 634 l2cap_start_rtx(channel); 635 break; 636 637 case L2CAP_STATE_CONFIG: 638 if (!hci_can_send_acl_packet_now(channel->handle)) break; 639 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 640 uint16_t flags = 0; 641 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 642 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 643 flags = 1; 644 } else { 645 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 646 } 647 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 648 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 649 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 650 config_options[0] = 1; // MTU 651 config_options[1] = 2; // len param 652 bt_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 653 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 654 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 655 } else { 656 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 657 } 658 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 659 } 660 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 661 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 662 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 663 channel->local_sig_id = l2cap_next_sig_id(); 664 config_options[0] = 1; // MTU 665 config_options[1] = 2; // len param 666 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 667 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 668 l2cap_start_rtx(channel); 669 } 670 if (l2cap_channel_ready_for_open(channel)){ 671 channel->state = L2CAP_STATE_OPEN; 672 l2cap_emit_channel_opened(channel, 0); // success 673 l2cap_emit_credits(channel, 1); 674 } 675 break; 676 677 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 678 if (!hci_can_send_acl_packet_now(channel->handle)) break; 679 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 680 // 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 :) 681 l2cap_finialize_channel_close(channel); // -- remove from list 682 break; 683 684 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 685 if (!hci_can_send_acl_packet_now(channel->handle)) break; 686 channel->local_sig_id = l2cap_next_sig_id(); 687 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 688 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 689 break; 690 default: 691 break; 692 } 693 } 694 695 #ifdef HAVE_BLE 696 // send l2cap con paramter update if necessary 697 hci_connections_get_iterator(&it); 698 while(linked_list_iterator_has_next(&it)){ 699 hci_connection_t * connection = (hci_connection_t *) linked_list_iterator_next(&it); 700 int result; 701 702 switch (connection->le_con_parameter_update_state){ 703 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 704 result = 0; 705 break; 706 case CON_PARAMETER_UPDATE_DENY: 707 result = 1; 708 break; 709 default: 710 result = -1; 711 break; 712 } 713 if (result < 0) break; 714 715 if (!hci_can_send_acl_packet_now(connection->con_handle)) break; 716 hci_reserve_packet_buffer(); 717 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 718 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 719 uint16_t len = l2cap_le_create_connection_parameter_update_response(acl_buffer, connection->con_handle, 0); 720 hci_send_acl_packet_buffer(len); 721 } 722 #endif 723 724 } 725 726 uint16_t l2cap_max_mtu(void){ 727 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 728 } 729 730 uint16_t l2cap_max_le_mtu(){ 731 return l2cap_max_mtu(); 732 } 733 734 static void l2cap_handle_connection_complete(uint16_t handle, l2cap_channel_t * channel){ 735 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 736 log_info("l2cap_handle_connection_complete expected state"); 737 // success, start l2cap handshake 738 channel->handle = handle; 739 channel->local_cid = l2cap_next_local_cid(); 740 // check remote SSP feature first 741 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 742 } 743 } 744 745 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 746 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 747 748 // we have been waiting for remote supported features, if both support SSP, 749 log_info("l2cap received remote supported features, sec_level_0_allowed for psm %u = %u", channel->psm, l2cap_security_level_0_allowed_for_PSM(channel->psm)); 750 if (hci_ssp_supported_on_both_sides(channel->handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 751 // request security level 2 752 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 753 gap_request_security_level(channel->handle, LEVEL_2); 754 return; 755 } 756 // fine, go ahead 757 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 758 } 759 760 // open outgoing L2CAP channel 761 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 762 bd_addr_t address, uint16_t psm, uint16_t mtu){ 763 764 log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 765 766 // alloc structure 767 l2cap_channel_t * chan = btstack_memory_l2cap_channel_get(); 768 if (!chan) { 769 // emit error event 770 l2cap_channel_t dummy_channel; 771 BD_ADDR_COPY(dummy_channel.address, address); 772 dummy_channel.psm = psm; 773 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 774 return; 775 } 776 // limit local mtu to max acl packet length 777 if (mtu > l2cap_max_mtu()) { 778 mtu = l2cap_max_mtu(); 779 } 780 781 // fill in 782 BD_ADDR_COPY(chan->address, address); 783 chan->psm = psm; 784 chan->handle = 0; 785 chan->connection = connection; 786 chan->packet_handler = packet_handler; 787 chan->remote_mtu = L2CAP_MINIMAL_MTU; 788 chan->local_mtu = mtu; 789 chan->packets_granted = 0; 790 791 // set initial state 792 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 793 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 794 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 795 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 796 chan->required_security_level = LEVEL_0; 797 798 // add to connections list 799 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 800 801 // check if hci connection is already usable 802 hci_connection_t * conn = hci_connection_for_bd_addr_and_type((bd_addr_t*)address, BD_ADDR_TYPE_CLASSIC); 803 if (conn){ 804 log_info("l2cap_create_channel_internal, hci connection already exists"); 805 l2cap_handle_connection_complete(conn->con_handle, chan); 806 // check ir remote supported fearures are already received 807 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 808 l2cap_handle_remote_supported_features_received(chan); 809 } 810 } 811 812 l2cap_run(); 813 } 814 815 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 816 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 817 // find channel for local_cid 818 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 819 if (channel) { 820 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 821 } 822 // process 823 l2cap_run(); 824 } 825 826 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 827 linked_list_iterator_t it; 828 linked_list_iterator_init(&it, &l2cap_channels); 829 while (linked_list_iterator_has_next(&it)){ 830 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 831 if ( BD_ADDR_CMP( channel->address, address) != 0) continue; 832 // channel for this address found 833 switch (channel->state){ 834 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 835 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 836 // failure, forward error code 837 l2cap_emit_channel_opened(channel, status); 838 // discard channel 839 l2cap_stop_rtx(channel); 840 linked_list_iterator_remove(&it); 841 btstack_memory_l2cap_channel_free(channel); 842 break; 843 default: 844 break; 845 } 846 } 847 } 848 849 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 850 linked_list_iterator_t it; 851 linked_list_iterator_init(&it, &l2cap_channels); 852 while (linked_list_iterator_has_next(&it)){ 853 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 854 if ( ! BD_ADDR_CMP( channel->address, address) ){ 855 l2cap_handle_connection_complete(handle, channel); 856 } 857 } 858 // process 859 l2cap_run(); 860 } 861 862 void l2cap_event_handler(uint8_t *packet, uint16_t size){ 863 864 bd_addr_t address; 865 hci_con_handle_t handle; 866 linked_list_iterator_t it; 867 int hci_con_used; 868 869 switch(packet[0]){ 870 871 // handle connection complete events 872 case HCI_EVENT_CONNECTION_COMPLETE: 873 bt_flip_addr(address, &packet[5]); 874 if (packet[2] == 0){ 875 handle = READ_BT_16(packet, 3); 876 l2cap_handle_connection_success_for_addr(address, handle); 877 } else { 878 l2cap_handle_connection_failed_for_addr(address, packet[2]); 879 } 880 break; 881 882 // handle successful create connection cancel command 883 case HCI_EVENT_COMMAND_COMPLETE: 884 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 885 if (packet[5] == 0){ 886 bt_flip_addr(address, &packet[6]); 887 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 888 l2cap_handle_connection_failed_for_addr(address, 0x16); 889 } 890 } 891 l2cap_run(); // try sending signaling packets first 892 break; 893 894 case HCI_EVENT_COMMAND_STATUS: 895 l2cap_run(); // try sending signaling packets first 896 break; 897 898 // handle disconnection complete events 899 case HCI_EVENT_DISCONNECTION_COMPLETE: 900 // send l2cap disconnect events for all channels on this handle and free them 901 handle = READ_BT_16(packet, 3); 902 linked_list_iterator_init(&it, &l2cap_channels); 903 while (linked_list_iterator_has_next(&it)){ 904 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 905 if (channel->handle != handle) continue; 906 l2cap_emit_channel_closed(channel); 907 l2cap_stop_rtx(channel); 908 linked_list_iterator_remove(&it); 909 btstack_memory_l2cap_channel_free(channel); 910 } 911 break; 912 913 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 914 l2cap_run(); // try sending signaling packets first 915 l2cap_hand_out_credits(); 916 break; 917 918 // HCI Connection Timeouts 919 case L2CAP_EVENT_TIMEOUT_CHECK: 920 handle = READ_BT_16(packet, 2); 921 if (hci_authentication_active_for_handle(handle)) break; 922 hci_con_used = 0; 923 linked_list_iterator_init(&it, &l2cap_channels); 924 while (linked_list_iterator_has_next(&it)){ 925 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 926 if (channel->handle != handle) continue; 927 hci_con_used = 1; 928 break; 929 } 930 if (hci_con_used) break; 931 if (!hci_can_send_command_packet_now()) break; 932 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 933 break; 934 935 case DAEMON_EVENT_HCI_PACKET_SENT: 936 linked_list_iterator_init(&it, &l2cap_channels); 937 while (linked_list_iterator_has_next(&it)){ 938 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 939 if (!channel->packet_handler) continue; 940 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 941 } 942 if (attribute_protocol_packet_handler) { 943 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 944 } 945 if (security_protocol_packet_handler) { 946 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 947 } 948 break; 949 950 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 951 handle = READ_BT_16(packet, 3); 952 linked_list_iterator_init(&it, &l2cap_channels); 953 while (linked_list_iterator_has_next(&it)){ 954 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 955 if (channel->handle != handle) continue; 956 l2cap_handle_remote_supported_features_received(channel); 957 break; 958 } 959 break; 960 961 case GAP_SECURITY_LEVEL: 962 handle = READ_BT_16(packet, 2); 963 log_info("l2cap - security level update"); 964 linked_list_iterator_init(&it, &l2cap_channels); 965 while (linked_list_iterator_has_next(&it)){ 966 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 967 if (channel->handle != handle) continue; 968 969 log_info("l2cap - state %u", channel->state); 970 971 gap_security_level_t actual_level = packet[4]; 972 gap_security_level_t required_level = channel->required_security_level; 973 974 switch (channel->state){ 975 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 976 if (actual_level >= required_level){ 977 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 978 l2cap_emit_connection_request(channel); 979 } else { 980 channel->reason = 0x03; // security block 981 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 982 } 983 break; 984 985 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 986 if (actual_level >= required_level){ 987 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 988 } else { 989 // disconnnect, authentication not good enough 990 hci_disconnect_security_block(handle); 991 } 992 break; 993 994 default: 995 break; 996 } 997 } 998 break; 999 1000 default: 1001 break; 1002 } 1003 1004 // pass on: main packet handler, att and sm packet handlers 1005 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 1006 if (attribute_protocol_packet_handler){ 1007 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 1008 } 1009 if (security_protocol_packet_handler) { 1010 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 1011 } 1012 1013 l2cap_run(); 1014 } 1015 1016 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1017 channel->remote_sig_id = identifier; 1018 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1019 l2cap_run(); 1020 } 1021 1022 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 1023 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1024 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1025 signaling_responses[signaling_responses_pending].handle = handle; 1026 signaling_responses[signaling_responses_pending].code = code; 1027 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1028 signaling_responses[signaling_responses_pending].data = data; 1029 signaling_responses_pending++; 1030 l2cap_run(); 1031 } 1032 } 1033 1034 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1035 1036 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1037 l2cap_service_t *service = l2cap_get_service(psm); 1038 if (!service) { 1039 // 0x0002 PSM not supported 1040 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 1041 return; 1042 } 1043 1044 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1045 if (!hci_connection) { 1046 // 1047 log_error("no hci_connection for handle %u", handle); 1048 return; 1049 } 1050 1051 // reject connection (0x03 security block) and disconnect if both have SSP, connection is not encrypted and PSM != SDP 1052 if ( hci_ssp_supported_on_both_sides(handle) 1053 && gap_security_level(handle) == LEVEL_0 1054 && !l2cap_security_level_0_allowed_for_PSM(psm)){ 1055 1056 // 0x0003 Security Block 1057 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0003); 1058 return; 1059 } 1060 1061 1062 // alloc structure 1063 // log_info("l2cap_handle_connection_request register channel"); 1064 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 1065 if (!channel){ 1066 // 0x0004 No resources available 1067 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 1068 return; 1069 } 1070 1071 // fill in 1072 BD_ADDR_COPY(channel->address, hci_connection->address); 1073 channel->psm = psm; 1074 channel->handle = handle; 1075 channel->connection = service->connection; 1076 channel->packet_handler = service->packet_handler; 1077 channel->local_cid = l2cap_next_local_cid(); 1078 channel->remote_cid = source_cid; 1079 channel->local_mtu = service->mtu; 1080 channel->remote_mtu = L2CAP_DEFAULT_MTU; 1081 channel->packets_granted = 0; 1082 channel->remote_sig_id = sig_id; 1083 channel->required_security_level = service->required_security_level; 1084 1085 // limit local mtu to max acl packet length 1086 if (channel->local_mtu > l2cap_max_mtu()) { 1087 channel->local_mtu = l2cap_max_mtu(); 1088 } 1089 1090 // set initial state 1091 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1092 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 1093 1094 // add to connections list 1095 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 1096 1097 // assert security requirements 1098 gap_request_security_level(handle, channel->required_security_level); 1099 } 1100 1101 void l2cap_accept_connection_internal(uint16_t local_cid){ 1102 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1103 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1104 if (!channel) { 1105 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 1106 return; 1107 } 1108 1109 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1110 1111 // process 1112 l2cap_run(); 1113 } 1114 1115 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 1116 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); 1117 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1118 if (!channel) { 1119 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 1120 return; 1121 } 1122 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1123 channel->reason = reason; 1124 l2cap_run(); 1125 } 1126 1127 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1128 1129 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1130 1131 uint16_t flags = READ_BT_16(command, 6); 1132 if (flags & 1) { 1133 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1134 } 1135 1136 // accept the other's configuration options 1137 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1138 uint16_t pos = 8; 1139 while (pos < end_pos){ 1140 uint8_t option_hint = command[pos] >> 7; 1141 uint8_t option_type = command[pos] & 0x7f; 1142 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1143 pos++; 1144 uint8_t length = command[pos++]; 1145 // MTU { type(8): 1, len(8):2, MTU(16) } 1146 if (option_type == 1 && length == 2){ 1147 channel->remote_mtu = READ_BT_16(command, pos); 1148 // log_info("l2cap cid 0x%02x, remote mtu %u", channel->local_cid, channel->remote_mtu); 1149 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1150 } 1151 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1152 if (option_type == 2 && length == 2){ 1153 channel->flush_timeout = READ_BT_16(command, pos); 1154 } 1155 // check for unknown options 1156 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1157 log_info("l2cap cid %u, unknown options", channel->local_cid); 1158 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1159 } 1160 pos += length; 1161 } 1162 } 1163 1164 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1165 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1166 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1167 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1168 return 1; 1169 } 1170 1171 1172 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1173 1174 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1175 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1176 uint16_t result = 0; 1177 1178 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1179 1180 // handle DISCONNECT REQUESTS seperately 1181 if (code == DISCONNECTION_REQUEST){ 1182 switch (channel->state){ 1183 case L2CAP_STATE_CONFIG: 1184 case L2CAP_STATE_OPEN: 1185 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1186 case L2CAP_STATE_WAIT_DISCONNECT: 1187 l2cap_handle_disconnect_request(channel, identifier); 1188 break; 1189 1190 default: 1191 // ignore in other states 1192 break; 1193 } 1194 return; 1195 } 1196 1197 // @STATEMACHINE(l2cap) 1198 switch (channel->state) { 1199 1200 case L2CAP_STATE_WAIT_CONNECT_RSP: 1201 switch (code){ 1202 case CONNECTION_RESPONSE: 1203 l2cap_stop_rtx(channel); 1204 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1205 switch (result) { 1206 case 0: 1207 // successful connection 1208 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1209 channel->state = L2CAP_STATE_CONFIG; 1210 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1211 break; 1212 case 1: 1213 // connection pending. get some coffee, but start the ERTX 1214 l2cap_start_ertx(channel); 1215 break; 1216 default: 1217 // channel closed 1218 channel->state = L2CAP_STATE_CLOSED; 1219 // map l2cap connection response result to BTstack status enumeration 1220 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1221 1222 // drop link key if security block 1223 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1224 hci_drop_link_key_for_bd_addr(&channel->address); 1225 } 1226 1227 // discard channel 1228 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1229 btstack_memory_l2cap_channel_free(channel); 1230 break; 1231 } 1232 break; 1233 1234 default: 1235 //@TODO: implement other signaling packets 1236 break; 1237 } 1238 break; 1239 1240 case L2CAP_STATE_CONFIG: 1241 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1242 switch (code) { 1243 case CONFIGURE_REQUEST: 1244 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1245 l2cap_signaling_handle_configure_request(channel, command); 1246 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1247 // only done if continuation not set 1248 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1249 } 1250 break; 1251 case CONFIGURE_RESPONSE: 1252 l2cap_stop_rtx(channel); 1253 switch (result){ 1254 case 0: // success 1255 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1256 break; 1257 case 4: // pending 1258 l2cap_start_ertx(channel); 1259 break; 1260 default: 1261 // retry on negative result 1262 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1263 break; 1264 } 1265 break; 1266 default: 1267 break; 1268 } 1269 if (l2cap_channel_ready_for_open(channel)){ 1270 // for open: 1271 channel->state = L2CAP_STATE_OPEN; 1272 l2cap_emit_channel_opened(channel, 0); 1273 l2cap_emit_credits(channel, 1); 1274 } 1275 break; 1276 1277 case L2CAP_STATE_WAIT_DISCONNECT: 1278 switch (code) { 1279 case DISCONNECTION_RESPONSE: 1280 l2cap_finialize_channel_close(channel); 1281 break; 1282 default: 1283 //@TODO: implement other signaling packets 1284 break; 1285 } 1286 break; 1287 1288 case L2CAP_STATE_CLOSED: 1289 // @TODO handle incoming requests 1290 break; 1291 1292 case L2CAP_STATE_OPEN: 1293 //@TODO: implement other signaling packets, e.g. re-configure 1294 break; 1295 default: 1296 break; 1297 } 1298 // log_info("new state %u", channel->state); 1299 } 1300 1301 1302 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1303 1304 // get code, signalind identifier and command len 1305 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1306 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1307 1308 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1309 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1310 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1311 return; 1312 } 1313 1314 // general commands without an assigned channel 1315 switch(code) { 1316 1317 case CONNECTION_REQUEST: { 1318 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1319 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1320 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1321 return; 1322 } 1323 1324 case ECHO_REQUEST: 1325 l2cap_register_signaling_response(handle, code, sig_id, 0); 1326 return; 1327 1328 case INFORMATION_REQUEST: { 1329 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1330 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1331 return; 1332 } 1333 1334 default: 1335 break; 1336 } 1337 1338 1339 // Get potential destination CID 1340 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1341 1342 // Find channel for this sig_id and connection handle 1343 linked_list_iterator_t it; 1344 linked_list_iterator_init(&it, &l2cap_channels); 1345 while (linked_list_iterator_has_next(&it)){ 1346 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 1347 if (channel->handle != handle) continue; 1348 if (code & 1) { 1349 // match odd commands (responses) by previous signaling identifier 1350 if (channel->local_sig_id == sig_id) { 1351 l2cap_signaling_handler_channel(channel, command); 1352 break; 1353 } 1354 } else { 1355 // match even commands (requests) by local channel id 1356 if (channel->local_cid == dest_cid) { 1357 l2cap_signaling_handler_channel(channel, command); 1358 break; 1359 } 1360 } 1361 } 1362 } 1363 1364 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 1365 1366 // Get Channel ID 1367 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1368 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1369 1370 switch (channel_id) { 1371 1372 case L2CAP_CID_SIGNALING: { 1373 1374 uint16_t command_offset = 8; 1375 while (command_offset < size) { 1376 1377 // handle signaling commands 1378 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1379 1380 // increment command_offset 1381 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1382 } 1383 break; 1384 } 1385 1386 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1387 if (attribute_protocol_packet_handler) { 1388 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1389 } 1390 break; 1391 1392 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1393 if (security_protocol_packet_handler) { 1394 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1395 } 1396 break; 1397 1398 case L2CAP_CID_SIGNALING_LE: { 1399 switch (packet[8]){ 1400 case CONNECTION_PARAMETER_UPDATE_RESPONSE: { 1401 uint16_t result = READ_BT_16(packet, 12); 1402 l2cap_emit_connection_parameter_update_response(handle, result); 1403 break; 1404 } 1405 case CONNECTION_PARAMETER_UPDATE_REQUEST: { 1406 uint8_t event[10]; 1407 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 1408 event[1] = 8; 1409 memcpy(&event[2], &packet[12], 8); 1410 1411 hci_connection_t * connection = hci_connection_for_handle(handle); 1412 if (connection){ 1413 int update_parameter = 1; 1414 le_connection_parameter_range_t existing_range = gap_le_get_connection_parameter_range(); 1415 uint16_t le_conn_interval_min = READ_BT_16(packet,12); 1416 uint16_t le_conn_interval_max = READ_BT_16(packet,14); 1417 uint16_t le_conn_latency = READ_BT_16(packet,16); 1418 uint16_t le_supervision_timeout = READ_BT_16(packet,18); 1419 1420 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 1421 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 1422 1423 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 1424 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 1425 1426 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 1427 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 1428 1429 if (update_parameter){ 1430 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 1431 connection->le_conn_interval_min = le_conn_interval_min; 1432 connection->le_conn_interval_max = le_conn_interval_max; 1433 connection->le_conn_latency = le_conn_latency; 1434 connection->le_supervision_timeout = le_supervision_timeout; 1435 } else { 1436 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 1437 } 1438 } 1439 1440 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1441 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, event, sizeof(event)); 1442 1443 break; 1444 } 1445 default: { 1446 uint8_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1447 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1448 break; 1449 } 1450 } 1451 break; 1452 } 1453 1454 default: { 1455 // Find channel for this channel_id and connection handle 1456 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1457 if (channel) { 1458 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1459 } 1460 break; 1461 } 1462 } 1463 } 1464 1465 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1466 switch (packet_type) { 1467 case HCI_EVENT_PACKET: 1468 l2cap_event_handler(packet, size); 1469 break; 1470 case HCI_ACL_DATA_PACKET: 1471 l2cap_acl_handler(packet, size); 1472 break; 1473 default: 1474 break; 1475 } 1476 l2cap_run(); 1477 } 1478 1479 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1480 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1481 channel->state = L2CAP_STATE_CLOSED; 1482 l2cap_emit_channel_closed(channel); 1483 // discard channel 1484 l2cap_stop_rtx(channel); 1485 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1486 btstack_memory_l2cap_channel_free(channel); 1487 } 1488 1489 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1490 linked_list_iterator_t it; 1491 linked_list_iterator_init(&it, &l2cap_services); 1492 while (linked_list_iterator_has_next(&it)){ 1493 l2cap_service_t * service = (l2cap_service_t *) linked_list_iterator_next(&it); 1494 if ( service->psm == psm){ 1495 return service; 1496 }; 1497 } 1498 return NULL; 1499 } 1500 1501 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){ 1502 1503 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u connection %p", psm, mtu, connection); 1504 1505 // check for alread registered psm 1506 // TODO: emit error event 1507 l2cap_service_t *service = l2cap_get_service(psm); 1508 if (service) { 1509 log_error("l2cap_register_service_internal: PSM %u already registered", psm); 1510 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1511 return; 1512 } 1513 1514 // alloc structure 1515 // TODO: emit error event 1516 service = btstack_memory_l2cap_service_get(); 1517 if (!service) { 1518 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 1519 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1520 return; 1521 } 1522 1523 // fill in 1524 service->psm = psm; 1525 service->mtu = mtu; 1526 service->connection = connection; 1527 service->packet_handler = packet_handler; 1528 service->required_security_level = security_level; 1529 1530 // add to services list 1531 linked_list_add(&l2cap_services, (linked_item_t *) service); 1532 1533 // enable page scan 1534 hci_connectable_control(1); 1535 1536 // done 1537 l2cap_emit_service_registered(connection, 0, psm); 1538 } 1539 1540 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1541 1542 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1543 1544 l2cap_service_t *service = l2cap_get_service(psm); 1545 if (!service) return; 1546 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1547 btstack_memory_l2cap_service_free(service); 1548 1549 // disable page scan when no services registered 1550 if (!linked_list_empty(&l2cap_services)) return; 1551 hci_connectable_control(0); 1552 } 1553 1554 1555 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1556 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1557 switch(channel_id){ 1558 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1559 attribute_protocol_packet_handler = packet_handler; 1560 break; 1561 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1562 security_protocol_packet_handler = packet_handler; 1563 break; 1564 } 1565 } 1566 1567 #ifdef HAVE_BLE 1568 1569 // Request LE connection parameter update 1570 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){ 1571 if (!hci_can_send_acl_packet_now(handle)){ 1572 log_info("l2cap_send_signaling_packet, cannot send"); 1573 return BTSTACK_ACL_BUFFERS_FULL; 1574 } 1575 // log_info("l2cap_send_signaling_packet type %u", cmd); 1576 hci_reserve_packet_buffer(); 1577 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1578 uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); 1579 return hci_send_acl_packet_buffer(len); 1580 } 1581 #endif 1582 1583