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 hci_disconnect_security_block(handle); 534 break; 535 case ECHO_REQUEST: 536 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 537 break; 538 case INFORMATION_REQUEST: 539 switch (infoType){ 540 case 1: { // Connectionless MTU 541 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 542 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 543 break; 544 } 545 case 2: { // Extended Features Supported 546 // extended features request supported, only supporing fixed channel map 547 uint32_t features = 0x80; 548 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 549 break; 550 } 551 case 3: { // Fixed Channels Supported 552 uint8_t map[8]; 553 memset(map, 0, 8); 554 map[0] = 0x01; // L2CAP Signaling Channel 555 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 556 break; 557 } 558 default: 559 // all other types are not supported 560 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 561 break; 562 } 563 break; 564 case COMMAND_REJECT: 565 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 566 #ifdef HAVE_BLE 567 case COMMAND_REJECT_LE: 568 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 569 break; 570 #endif 571 default: 572 // should not happen 573 break; 574 } 575 576 // remove first item 577 signaling_responses_pending--; 578 int i; 579 for (i=0; i < signaling_responses_pending; i++){ 580 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 581 } 582 } 583 584 uint8_t config_options[4]; 585 linked_list_iterator_t it; 586 linked_list_iterator_init(&it, &l2cap_channels); 587 while (linked_list_iterator_has_next(&it)){ 588 589 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 590 // log_info("l2cap_run: state %u, var 0x%02x", channel->state, channel->state_var); 591 switch (channel->state){ 592 593 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 594 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 595 if (!hci_can_send_acl_packet_now(channel->handle)) break; 596 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 597 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 598 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 599 } 600 break; 601 602 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 603 if (!hci_can_send_command_packet_now()) break; 604 // send connection request - set state first 605 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 606 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 607 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 608 break; 609 610 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 611 if (!hci_can_send_acl_packet_now(channel->handle)) break; 612 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 613 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 614 l2cap_stop_rtx(channel); 615 linked_list_iterator_remove(&it); 616 btstack_memory_l2cap_channel_free(channel); 617 break; 618 619 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 620 if (!hci_can_send_acl_packet_now(channel->handle)) break; 621 channel->state = L2CAP_STATE_CONFIG; 622 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 623 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 624 break; 625 626 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 627 if (!hci_can_send_acl_packet_now(channel->handle)) break; 628 // success, start l2cap handshake 629 channel->local_sig_id = l2cap_next_sig_id(); 630 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 631 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 632 l2cap_start_rtx(channel); 633 break; 634 635 case L2CAP_STATE_CONFIG: 636 if (!hci_can_send_acl_packet_now(channel->handle)) break; 637 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 638 uint16_t flags = 0; 639 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 640 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 641 flags = 1; 642 } else { 643 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 644 } 645 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 646 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 647 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 648 config_options[0] = 1; // MTU 649 config_options[1] = 2; // len param 650 bt_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 651 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 652 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 653 } else { 654 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 655 } 656 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 657 } 658 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 659 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 660 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 661 channel->local_sig_id = l2cap_next_sig_id(); 662 config_options[0] = 1; // MTU 663 config_options[1] = 2; // len param 664 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 665 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 666 l2cap_start_rtx(channel); 667 } 668 if (l2cap_channel_ready_for_open(channel)){ 669 channel->state = L2CAP_STATE_OPEN; 670 l2cap_emit_channel_opened(channel, 0); // success 671 l2cap_emit_credits(channel, 1); 672 } 673 break; 674 675 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 676 if (!hci_can_send_acl_packet_now(channel->handle)) break; 677 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 678 // 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 :) 679 l2cap_finialize_channel_close(channel); // -- remove from list 680 break; 681 682 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 683 if (!hci_can_send_acl_packet_now(channel->handle)) break; 684 channel->local_sig_id = l2cap_next_sig_id(); 685 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 686 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 687 break; 688 default: 689 break; 690 } 691 } 692 693 #ifdef HAVE_BLE 694 // send l2cap con paramter update if necessary 695 hci_connections_get_iterator(&it); 696 while(linked_list_iterator_has_next(&it)){ 697 hci_connection_t * connection = (hci_connection_t *) linked_list_iterator_next(&it); 698 int result; 699 700 switch (connection->le_con_parameter_update_state){ 701 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 702 result = 0; 703 break; 704 case CON_PARAMETER_UPDATE_DENY: 705 result = 1; 706 break; 707 default: 708 result = -1; 709 break; 710 } 711 if (result < 0) break; 712 713 if (!hci_can_send_acl_packet_now(connection->con_handle)) break; 714 hci_reserve_packet_buffer(); 715 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 716 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 717 uint16_t len = l2cap_le_create_connection_parameter_update_response(acl_buffer, connection->con_handle, 0); 718 hci_send_acl_packet_buffer(len); 719 } 720 #endif 721 722 } 723 724 uint16_t l2cap_max_mtu(void){ 725 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 726 } 727 728 uint16_t l2cap_max_le_mtu(){ 729 return l2cap_max_mtu(); 730 } 731 732 static void l2cap_handle_connection_complete(uint16_t handle, l2cap_channel_t * channel){ 733 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 734 log_info("l2cap_handle_connection_complete expected state"); 735 // success, start l2cap handshake 736 channel->handle = handle; 737 channel->local_cid = l2cap_next_local_cid(); 738 // check remote SSP feature first 739 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 740 } 741 } 742 743 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 744 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 745 746 // we have been waiting for remote supported features, if both support SSP, 747 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)); 748 if (hci_ssp_supported_on_both_sides(channel->handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 749 // request security level 2 750 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 751 gap_request_security_level(channel->handle, LEVEL_2); 752 return; 753 } 754 // fine, go ahead 755 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 756 } 757 758 // open outgoing L2CAP channel 759 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 760 bd_addr_t address, uint16_t psm, uint16_t mtu){ 761 762 log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 763 764 // alloc structure 765 l2cap_channel_t * chan = btstack_memory_l2cap_channel_get(); 766 if (!chan) { 767 // emit error event 768 l2cap_channel_t dummy_channel; 769 BD_ADDR_COPY(dummy_channel.address, address); 770 dummy_channel.psm = psm; 771 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 772 return; 773 } 774 // limit local mtu to max acl packet length 775 if (mtu > l2cap_max_mtu()) { 776 mtu = l2cap_max_mtu(); 777 } 778 779 // fill in 780 BD_ADDR_COPY(chan->address, address); 781 chan->psm = psm; 782 chan->handle = 0; 783 chan->connection = connection; 784 chan->packet_handler = packet_handler; 785 chan->remote_mtu = L2CAP_MINIMAL_MTU; 786 chan->local_mtu = mtu; 787 chan->packets_granted = 0; 788 789 // set initial state 790 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 791 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 792 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 793 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 794 chan->required_security_level = LEVEL_0; 795 796 // add to connections list 797 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 798 799 // check if hci connection is already usable 800 hci_connection_t * conn = hci_connection_for_bd_addr_and_type((bd_addr_t*)address, BD_ADDR_TYPE_CLASSIC); 801 if (conn){ 802 log_info("l2cap_create_channel_internal, hci connection already exists"); 803 l2cap_handle_connection_complete(conn->con_handle, chan); 804 // check ir remote supported fearures are already received 805 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 806 l2cap_handle_remote_supported_features_received(chan); 807 } 808 } 809 810 l2cap_run(); 811 } 812 813 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 814 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 815 // find channel for local_cid 816 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 817 if (channel) { 818 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 819 } 820 // process 821 l2cap_run(); 822 } 823 824 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 825 linked_list_iterator_t it; 826 linked_list_iterator_init(&it, &l2cap_channels); 827 while (linked_list_iterator_has_next(&it)){ 828 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 829 if ( BD_ADDR_CMP( channel->address, address) != 0) continue; 830 // channel for this address found 831 switch (channel->state){ 832 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 833 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 834 // failure, forward error code 835 l2cap_emit_channel_opened(channel, status); 836 // discard channel 837 l2cap_stop_rtx(channel); 838 linked_list_iterator_remove(&it); 839 btstack_memory_l2cap_channel_free(channel); 840 break; 841 default: 842 break; 843 } 844 } 845 } 846 847 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 848 linked_list_iterator_t it; 849 linked_list_iterator_init(&it, &l2cap_channels); 850 while (linked_list_iterator_has_next(&it)){ 851 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 852 if ( ! BD_ADDR_CMP( channel->address, address) ){ 853 l2cap_handle_connection_complete(handle, channel); 854 } 855 } 856 // process 857 l2cap_run(); 858 } 859 860 void l2cap_event_handler(uint8_t *packet, uint16_t size){ 861 862 bd_addr_t address; 863 hci_con_handle_t handle; 864 linked_list_iterator_t it; 865 int hci_con_used; 866 867 switch(packet[0]){ 868 869 // handle connection complete events 870 case HCI_EVENT_CONNECTION_COMPLETE: 871 bt_flip_addr(address, &packet[5]); 872 if (packet[2] == 0){ 873 handle = READ_BT_16(packet, 3); 874 l2cap_handle_connection_success_for_addr(address, handle); 875 } else { 876 l2cap_handle_connection_failed_for_addr(address, packet[2]); 877 } 878 break; 879 880 // handle successful create connection cancel command 881 case HCI_EVENT_COMMAND_COMPLETE: 882 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 883 if (packet[5] == 0){ 884 bt_flip_addr(address, &packet[6]); 885 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 886 l2cap_handle_connection_failed_for_addr(address, 0x16); 887 } 888 } 889 l2cap_run(); // try sending signaling packets first 890 break; 891 892 case HCI_EVENT_COMMAND_STATUS: 893 l2cap_run(); // try sending signaling packets first 894 break; 895 896 // handle disconnection complete events 897 case HCI_EVENT_DISCONNECTION_COMPLETE: 898 // send l2cap disconnect events for all channels on this handle and free them 899 handle = READ_BT_16(packet, 3); 900 linked_list_iterator_init(&it, &l2cap_channels); 901 while (linked_list_iterator_has_next(&it)){ 902 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 903 if (channel->handle != handle) continue; 904 l2cap_emit_channel_closed(channel); 905 l2cap_stop_rtx(channel); 906 linked_list_iterator_remove(&it); 907 btstack_memory_l2cap_channel_free(channel); 908 } 909 break; 910 911 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 912 l2cap_run(); // try sending signaling packets first 913 l2cap_hand_out_credits(); 914 break; 915 916 // HCI Connection Timeouts 917 case L2CAP_EVENT_TIMEOUT_CHECK: 918 handle = READ_BT_16(packet, 2); 919 if (hci_authentication_active_for_handle(handle)) break; 920 hci_con_used = 0; 921 linked_list_iterator_init(&it, &l2cap_channels); 922 while (linked_list_iterator_has_next(&it)){ 923 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 924 if (channel->handle != handle) continue; 925 hci_con_used = 1; 926 break; 927 } 928 if (hci_con_used) break; 929 if (!hci_can_send_command_packet_now()) break; 930 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 931 break; 932 933 case DAEMON_EVENT_HCI_PACKET_SENT: 934 linked_list_iterator_init(&it, &l2cap_channels); 935 while (linked_list_iterator_has_next(&it)){ 936 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 937 if (!channel->packet_handler) continue; 938 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 939 } 940 if (attribute_protocol_packet_handler) { 941 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 942 } 943 if (security_protocol_packet_handler) { 944 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 945 } 946 break; 947 948 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 949 handle = READ_BT_16(packet, 3); 950 linked_list_iterator_init(&it, &l2cap_channels); 951 while (linked_list_iterator_has_next(&it)){ 952 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 953 if (channel->handle != handle) continue; 954 l2cap_handle_remote_supported_features_received(channel); 955 break; 956 } 957 break; 958 959 case GAP_SECURITY_LEVEL: 960 handle = READ_BT_16(packet, 2); 961 log_info("l2cap - security level update"); 962 linked_list_iterator_init(&it, &l2cap_channels); 963 while (linked_list_iterator_has_next(&it)){ 964 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 965 if (channel->handle != handle) continue; 966 967 log_info("l2cap - state %u", channel->state); 968 969 gap_security_level_t actual_level = packet[4]; 970 gap_security_level_t required_level = channel->required_security_level; 971 972 switch (channel->state){ 973 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 974 if (actual_level >= required_level){ 975 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 976 l2cap_emit_connection_request(channel); 977 } else { 978 channel->reason = 0x03; // security block 979 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 980 } 981 break; 982 983 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 984 if (actual_level >= required_level){ 985 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 986 } else { 987 // disconnnect, authentication not good enough 988 hci_disconnect_security_block(handle); 989 } 990 break; 991 992 default: 993 break; 994 } 995 } 996 break; 997 998 default: 999 break; 1000 } 1001 1002 // pass on: main packet handler, att and sm packet handlers 1003 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 1004 if (attribute_protocol_packet_handler){ 1005 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 1006 } 1007 if (security_protocol_packet_handler) { 1008 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 1009 } 1010 1011 l2cap_run(); 1012 } 1013 1014 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1015 channel->remote_sig_id = identifier; 1016 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1017 l2cap_run(); 1018 } 1019 1020 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 1021 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1022 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1023 signaling_responses[signaling_responses_pending].handle = handle; 1024 signaling_responses[signaling_responses_pending].code = code; 1025 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1026 signaling_responses[signaling_responses_pending].data = data; 1027 signaling_responses_pending++; 1028 l2cap_run(); 1029 } 1030 } 1031 1032 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1033 1034 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1035 l2cap_service_t *service = l2cap_get_service(psm); 1036 if (!service) { 1037 // 0x0002 PSM not supported 1038 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 1039 return; 1040 } 1041 1042 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1043 if (!hci_connection) { 1044 // 1045 log_error("no hci_connection for handle %u", handle); 1046 return; 1047 } 1048 1049 // reject connection (0x03 security block) and disconnect if both have SSP, connection is not encrypted and PSM != SDP 1050 if ( hci_ssp_supported_on_both_sides(handle) 1051 && gap_security_level(handle) == LEVEL_0 1052 && !l2cap_security_level_0_allowed_for_PSM(psm)){ 1053 1054 // 0x0003 Security Block 1055 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0003); 1056 return; 1057 } 1058 1059 1060 // alloc structure 1061 // log_info("l2cap_handle_connection_request register channel"); 1062 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 1063 if (!channel){ 1064 // 0x0004 No resources available 1065 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 1066 return; 1067 } 1068 1069 // fill in 1070 BD_ADDR_COPY(channel->address, hci_connection->address); 1071 channel->psm = psm; 1072 channel->handle = handle; 1073 channel->connection = service->connection; 1074 channel->packet_handler = service->packet_handler; 1075 channel->local_cid = l2cap_next_local_cid(); 1076 channel->remote_cid = source_cid; 1077 channel->local_mtu = service->mtu; 1078 channel->remote_mtu = L2CAP_DEFAULT_MTU; 1079 channel->packets_granted = 0; 1080 channel->remote_sig_id = sig_id; 1081 channel->required_security_level = service->required_security_level; 1082 1083 // limit local mtu to max acl packet length 1084 if (channel->local_mtu > l2cap_max_mtu()) { 1085 channel->local_mtu = l2cap_max_mtu(); 1086 } 1087 1088 // set initial state 1089 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1090 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 1091 1092 // add to connections list 1093 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 1094 1095 // assert security requirements 1096 gap_request_security_level(handle, channel->required_security_level); 1097 } 1098 1099 void l2cap_accept_connection_internal(uint16_t local_cid){ 1100 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1101 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1102 if (!channel) { 1103 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 1104 return; 1105 } 1106 1107 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1108 1109 // process 1110 l2cap_run(); 1111 } 1112 1113 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 1114 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); 1115 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1116 if (!channel) { 1117 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 1118 return; 1119 } 1120 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1121 channel->reason = reason; 1122 l2cap_run(); 1123 } 1124 1125 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1126 1127 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1128 1129 uint16_t flags = READ_BT_16(command, 6); 1130 if (flags & 1) { 1131 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1132 } 1133 1134 // accept the other's configuration options 1135 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1136 uint16_t pos = 8; 1137 while (pos < end_pos){ 1138 uint8_t option_hint = command[pos] >> 7; 1139 uint8_t option_type = command[pos] & 0x7f; 1140 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1141 pos++; 1142 uint8_t length = command[pos++]; 1143 // MTU { type(8): 1, len(8):2, MTU(16) } 1144 if (option_type == 1 && length == 2){ 1145 channel->remote_mtu = READ_BT_16(command, pos); 1146 // log_info("l2cap cid 0x%02x, remote mtu %u", channel->local_cid, channel->remote_mtu); 1147 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1148 } 1149 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1150 if (option_type == 2 && length == 2){ 1151 channel->flush_timeout = READ_BT_16(command, pos); 1152 } 1153 // check for unknown options 1154 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1155 log_info("l2cap cid %u, unknown options", channel->local_cid); 1156 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1157 } 1158 pos += length; 1159 } 1160 } 1161 1162 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1163 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1164 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1165 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1166 return 1; 1167 } 1168 1169 1170 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1171 1172 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1173 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1174 uint16_t result = 0; 1175 1176 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1177 1178 // handle DISCONNECT REQUESTS seperately 1179 if (code == DISCONNECTION_REQUEST){ 1180 switch (channel->state){ 1181 case L2CAP_STATE_CONFIG: 1182 case L2CAP_STATE_OPEN: 1183 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1184 case L2CAP_STATE_WAIT_DISCONNECT: 1185 l2cap_handle_disconnect_request(channel, identifier); 1186 break; 1187 1188 default: 1189 // ignore in other states 1190 break; 1191 } 1192 return; 1193 } 1194 1195 // @STATEMACHINE(l2cap) 1196 switch (channel->state) { 1197 1198 case L2CAP_STATE_WAIT_CONNECT_RSP: 1199 switch (code){ 1200 case CONNECTION_RESPONSE: 1201 l2cap_stop_rtx(channel); 1202 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1203 switch (result) { 1204 case 0: 1205 // successful connection 1206 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1207 channel->state = L2CAP_STATE_CONFIG; 1208 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1209 break; 1210 case 1: 1211 // connection pending. get some coffee, but start the ERTX 1212 l2cap_start_ertx(channel); 1213 break; 1214 default: 1215 // channel closed 1216 channel->state = L2CAP_STATE_CLOSED; 1217 // map l2cap connection response result to BTstack status enumeration 1218 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1219 1220 // drop link key if security block 1221 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1222 hci_drop_link_key_for_bd_addr(&channel->address); 1223 } 1224 1225 // discard channel 1226 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1227 btstack_memory_l2cap_channel_free(channel); 1228 break; 1229 } 1230 break; 1231 1232 default: 1233 //@TODO: implement other signaling packets 1234 break; 1235 } 1236 break; 1237 1238 case L2CAP_STATE_CONFIG: 1239 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1240 switch (code) { 1241 case CONFIGURE_REQUEST: 1242 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1243 l2cap_signaling_handle_configure_request(channel, command); 1244 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1245 // only done if continuation not set 1246 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1247 } 1248 break; 1249 case CONFIGURE_RESPONSE: 1250 l2cap_stop_rtx(channel); 1251 switch (result){ 1252 case 0: // success 1253 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1254 break; 1255 case 4: // pending 1256 l2cap_start_ertx(channel); 1257 break; 1258 default: 1259 // retry on negative result 1260 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1261 break; 1262 } 1263 break; 1264 default: 1265 break; 1266 } 1267 if (l2cap_channel_ready_for_open(channel)){ 1268 // for open: 1269 channel->state = L2CAP_STATE_OPEN; 1270 l2cap_emit_channel_opened(channel, 0); 1271 l2cap_emit_credits(channel, 1); 1272 } 1273 break; 1274 1275 case L2CAP_STATE_WAIT_DISCONNECT: 1276 switch (code) { 1277 case DISCONNECTION_RESPONSE: 1278 l2cap_finialize_channel_close(channel); 1279 break; 1280 default: 1281 //@TODO: implement other signaling packets 1282 break; 1283 } 1284 break; 1285 1286 case L2CAP_STATE_CLOSED: 1287 // @TODO handle incoming requests 1288 break; 1289 1290 case L2CAP_STATE_OPEN: 1291 //@TODO: implement other signaling packets, e.g. re-configure 1292 break; 1293 default: 1294 break; 1295 } 1296 // log_info("new state %u", channel->state); 1297 } 1298 1299 1300 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1301 1302 // get code, signalind identifier and command len 1303 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1304 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1305 1306 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1307 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1308 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1309 return; 1310 } 1311 1312 // general commands without an assigned channel 1313 switch(code) { 1314 1315 case CONNECTION_REQUEST: { 1316 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1317 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1318 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1319 return; 1320 } 1321 1322 case ECHO_REQUEST: 1323 l2cap_register_signaling_response(handle, code, sig_id, 0); 1324 return; 1325 1326 case INFORMATION_REQUEST: { 1327 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1328 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1329 return; 1330 } 1331 1332 default: 1333 break; 1334 } 1335 1336 1337 // Get potential destination CID 1338 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1339 1340 // Find channel for this sig_id and connection handle 1341 linked_list_iterator_t it; 1342 linked_list_iterator_init(&it, &l2cap_channels); 1343 while (linked_list_iterator_has_next(&it)){ 1344 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 1345 if (channel->handle != handle) continue; 1346 if (code & 1) { 1347 // match odd commands (responses) by previous signaling identifier 1348 if (channel->local_sig_id == sig_id) { 1349 l2cap_signaling_handler_channel(channel, command); 1350 break; 1351 } 1352 } else { 1353 // match even commands (requests) by local channel id 1354 if (channel->local_cid == dest_cid) { 1355 l2cap_signaling_handler_channel(channel, command); 1356 break; 1357 } 1358 } 1359 } 1360 } 1361 1362 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 1363 1364 // Get Channel ID 1365 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1366 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1367 1368 switch (channel_id) { 1369 1370 case L2CAP_CID_SIGNALING: { 1371 1372 uint16_t command_offset = 8; 1373 while (command_offset < size) { 1374 1375 // handle signaling commands 1376 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1377 1378 // increment command_offset 1379 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1380 } 1381 break; 1382 } 1383 1384 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1385 if (attribute_protocol_packet_handler) { 1386 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1387 } 1388 break; 1389 1390 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1391 if (security_protocol_packet_handler) { 1392 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1393 } 1394 break; 1395 1396 case L2CAP_CID_SIGNALING_LE: { 1397 switch (packet[8]){ 1398 case CONNECTION_PARAMETER_UPDATE_RESPONSE: { 1399 uint16_t result = READ_BT_16(packet, 12); 1400 l2cap_emit_connection_parameter_update_response(handle, result); 1401 break; 1402 } 1403 case CONNECTION_PARAMETER_UPDATE_REQUEST: { 1404 uint8_t event[10]; 1405 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 1406 event[1] = 8; 1407 memcpy(&event[2], &packet[12], 8); 1408 1409 hci_connection_t * connection = hci_connection_for_handle(handle); 1410 if (connection){ 1411 int update_parameter = 1; 1412 le_connection_parameter_range_t existing_range = gap_le_get_connection_parameter_range(); 1413 uint16_t le_conn_interval_min = READ_BT_16(packet,12); 1414 uint16_t le_conn_interval_max = READ_BT_16(packet,14); 1415 uint16_t le_conn_latency = READ_BT_16(packet,16); 1416 uint16_t le_supervision_timeout = READ_BT_16(packet,18); 1417 1418 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 1419 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 1420 1421 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 1422 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 1423 1424 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 1425 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 1426 1427 if (update_parameter){ 1428 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 1429 connection->le_conn_interval_min = le_conn_interval_min; 1430 connection->le_conn_interval_max = le_conn_interval_max; 1431 connection->le_conn_latency = le_conn_latency; 1432 connection->le_supervision_timeout = le_supervision_timeout; 1433 } else { 1434 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 1435 } 1436 } 1437 1438 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1439 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, event, sizeof(event)); 1440 1441 break; 1442 } 1443 default: { 1444 uint8_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1445 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1446 break; 1447 } 1448 } 1449 break; 1450 } 1451 1452 default: { 1453 // Find channel for this channel_id and connection handle 1454 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1455 if (channel) { 1456 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1457 } 1458 break; 1459 } 1460 } 1461 } 1462 1463 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1464 switch (packet_type) { 1465 case HCI_EVENT_PACKET: 1466 l2cap_event_handler(packet, size); 1467 break; 1468 case HCI_ACL_DATA_PACKET: 1469 l2cap_acl_handler(packet, size); 1470 break; 1471 default: 1472 break; 1473 } 1474 l2cap_run(); 1475 } 1476 1477 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1478 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1479 channel->state = L2CAP_STATE_CLOSED; 1480 l2cap_emit_channel_closed(channel); 1481 // discard channel 1482 l2cap_stop_rtx(channel); 1483 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1484 btstack_memory_l2cap_channel_free(channel); 1485 } 1486 1487 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1488 linked_list_iterator_t it; 1489 linked_list_iterator_init(&it, &l2cap_services); 1490 while (linked_list_iterator_has_next(&it)){ 1491 l2cap_service_t * service = (l2cap_service_t *) linked_list_iterator_next(&it); 1492 if ( service->psm == psm){ 1493 return service; 1494 }; 1495 } 1496 return NULL; 1497 } 1498 1499 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){ 1500 1501 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u connection %p", psm, mtu, connection); 1502 1503 // check for alread registered psm 1504 // TODO: emit error event 1505 l2cap_service_t *service = l2cap_get_service(psm); 1506 if (service) { 1507 log_error("l2cap_register_service_internal: PSM %u already registered", psm); 1508 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1509 return; 1510 } 1511 1512 // alloc structure 1513 // TODO: emit error event 1514 service = btstack_memory_l2cap_service_get(); 1515 if (!service) { 1516 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 1517 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1518 return; 1519 } 1520 1521 // fill in 1522 service->psm = psm; 1523 service->mtu = mtu; 1524 service->connection = connection; 1525 service->packet_handler = packet_handler; 1526 service->required_security_level = security_level; 1527 1528 // add to services list 1529 linked_list_add(&l2cap_services, (linked_item_t *) service); 1530 1531 // enable page scan 1532 hci_connectable_control(1); 1533 1534 // done 1535 l2cap_emit_service_registered(connection, 0, psm); 1536 } 1537 1538 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1539 1540 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1541 1542 l2cap_service_t *service = l2cap_get_service(psm); 1543 if (!service) return; 1544 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1545 btstack_memory_l2cap_service_free(service); 1546 1547 // disable page scan when no services registered 1548 if (!linked_list_empty(&l2cap_services)) return; 1549 hci_connectable_control(0); 1550 } 1551 1552 1553 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1554 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1555 switch(channel_id){ 1556 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1557 attribute_protocol_packet_handler = packet_handler; 1558 break; 1559 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1560 security_protocol_packet_handler = packet_handler; 1561 break; 1562 } 1563 } 1564 1565 #ifdef HAVE_BLE 1566 1567 // Request LE connection parameter update 1568 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){ 1569 if (!hci_can_send_acl_packet_now(handle)){ 1570 log_info("l2cap_send_signaling_packet, cannot send"); 1571 return BTSTACK_ACL_BUFFERS_FULL; 1572 } 1573 // log_info("l2cap_send_signaling_packet type %u", cmd); 1574 hci_reserve_packet_buffer(); 1575 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1576 uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); 1577 return hci_send_acl_packet_buffer(len); 1578 } 1579 #endif 1580 1581