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 uint8_t response_code = signaling_responses[0].code; 529 530 // remove first item before sending (to avoid sending response mutliple times) 531 signaling_responses_pending--; 532 int i; 533 for (i=0; i < signaling_responses_pending; i++){ 534 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 535 } 536 537 switch (response_code){ 538 case CONNECTION_REQUEST: 539 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 540 // also disconnect if result is 0x0003 - security blocked 541 if (result == 0x0003){ 542 hci_disconnect_security_block(handle); 543 } 544 break; 545 case ECHO_REQUEST: 546 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 547 break; 548 case INFORMATION_REQUEST: 549 switch (infoType){ 550 case 1: { // Connectionless MTU 551 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 552 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 553 break; 554 } 555 case 2: { // Extended Features Supported 556 // extended features request supported, only supporing fixed channel map 557 uint32_t features = 0x80; 558 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 559 break; 560 } 561 case 3: { // Fixed Channels Supported 562 uint8_t map[8]; 563 memset(map, 0, 8); 564 map[0] = 0x01; // L2CAP Signaling Channel 565 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 566 break; 567 } 568 default: 569 // all other types are not supported 570 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 571 break; 572 } 573 break; 574 case COMMAND_REJECT: 575 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 576 #ifdef HAVE_BLE 577 case COMMAND_REJECT_LE: 578 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 579 break; 580 #endif 581 default: 582 // should not happen 583 break; 584 } 585 } 586 587 uint8_t config_options[4]; 588 linked_list_iterator_t it; 589 linked_list_iterator_init(&it, &l2cap_channels); 590 while (linked_list_iterator_has_next(&it)){ 591 592 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 593 // log_info("l2cap_run: state %u, var 0x%02x", channel->state, channel->state_var); 594 switch (channel->state){ 595 596 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 597 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 598 if (!hci_can_send_acl_packet_now(channel->handle)) break; 599 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 600 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 601 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 602 } 603 break; 604 605 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 606 if (!hci_can_send_command_packet_now()) break; 607 // send connection request - set state first 608 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 609 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 610 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 611 break; 612 613 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 614 if (!hci_can_send_acl_packet_now(channel->handle)) break; 615 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 616 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 617 l2cap_stop_rtx(channel); 618 linked_list_iterator_remove(&it); 619 btstack_memory_l2cap_channel_free(channel); 620 break; 621 622 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 623 if (!hci_can_send_acl_packet_now(channel->handle)) break; 624 channel->state = L2CAP_STATE_CONFIG; 625 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 626 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 627 break; 628 629 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 630 if (!hci_can_send_acl_packet_now(channel->handle)) break; 631 // success, start l2cap handshake 632 channel->local_sig_id = l2cap_next_sig_id(); 633 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 634 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 635 l2cap_start_rtx(channel); 636 break; 637 638 case L2CAP_STATE_CONFIG: 639 if (!hci_can_send_acl_packet_now(channel->handle)) break; 640 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 641 uint16_t flags = 0; 642 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 643 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 644 flags = 1; 645 } else { 646 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 647 } 648 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 649 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 650 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 651 config_options[0] = 1; // MTU 652 config_options[1] = 2; // len param 653 bt_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 654 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 655 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 656 } else { 657 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 658 } 659 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 660 } 661 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 662 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 663 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 664 channel->local_sig_id = l2cap_next_sig_id(); 665 config_options[0] = 1; // MTU 666 config_options[1] = 2; // len param 667 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 668 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 669 l2cap_start_rtx(channel); 670 } 671 if (l2cap_channel_ready_for_open(channel)){ 672 channel->state = L2CAP_STATE_OPEN; 673 l2cap_emit_channel_opened(channel, 0); // success 674 l2cap_emit_credits(channel, 1); 675 } 676 break; 677 678 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 679 if (!hci_can_send_acl_packet_now(channel->handle)) break; 680 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 681 // 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 :) 682 l2cap_finialize_channel_close(channel); // -- remove from list 683 break; 684 685 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 686 if (!hci_can_send_acl_packet_now(channel->handle)) break; 687 channel->local_sig_id = l2cap_next_sig_id(); 688 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 689 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 690 break; 691 default: 692 break; 693 } 694 } 695 696 #ifdef HAVE_BLE 697 // send l2cap con paramter update if necessary 698 hci_connections_get_iterator(&it); 699 while(linked_list_iterator_has_next(&it)){ 700 hci_connection_t * connection = (hci_connection_t *) linked_list_iterator_next(&it); 701 int result; 702 703 switch (connection->le_con_parameter_update_state){ 704 case CON_PARAMETER_UPDATE_SEND_RESPONSE: 705 result = 0; 706 break; 707 case CON_PARAMETER_UPDATE_DENY: 708 result = 1; 709 break; 710 default: 711 result = -1; 712 break; 713 } 714 if (result < 0) break; 715 716 if (!hci_can_send_acl_packet_now(connection->con_handle)) break; 717 hci_reserve_packet_buffer(); 718 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 719 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_CHANGE_HCI_CON_PARAMETERS; 720 uint16_t len = l2cap_le_create_connection_parameter_update_response(acl_buffer, connection->con_handle, 0); 721 hci_send_acl_packet_buffer(len); 722 } 723 #endif 724 725 } 726 727 uint16_t l2cap_max_mtu(void){ 728 return HCI_ACL_PAYLOAD_SIZE - L2CAP_HEADER_SIZE; 729 } 730 731 uint16_t l2cap_max_le_mtu(){ 732 return l2cap_max_mtu(); 733 } 734 735 static void l2cap_handle_connection_complete(uint16_t handle, l2cap_channel_t * channel){ 736 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 737 log_info("l2cap_handle_connection_complete expected state"); 738 // success, start l2cap handshake 739 channel->handle = handle; 740 channel->local_cid = l2cap_next_local_cid(); 741 // check remote SSP feature first 742 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 743 } 744 } 745 746 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 747 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 748 749 // we have been waiting for remote supported features, if both support SSP, 750 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)); 751 if (hci_ssp_supported_on_both_sides(channel->handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 752 // request security level 2 753 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 754 gap_request_security_level(channel->handle, LEVEL_2); 755 return; 756 } 757 // fine, go ahead 758 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 759 } 760 761 // open outgoing L2CAP channel 762 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 763 bd_addr_t address, uint16_t psm, uint16_t mtu){ 764 765 log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 766 767 // alloc structure 768 l2cap_channel_t * chan = btstack_memory_l2cap_channel_get(); 769 if (!chan) { 770 // emit error event 771 l2cap_channel_t dummy_channel; 772 BD_ADDR_COPY(dummy_channel.address, address); 773 dummy_channel.psm = psm; 774 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 775 return; 776 } 777 // limit local mtu to max acl packet length - l2cap header 778 if (mtu > l2cap_max_mtu()) { 779 mtu = l2cap_max_mtu(); 780 } 781 782 // fill in 783 BD_ADDR_COPY(chan->address, address); 784 chan->psm = psm; 785 chan->handle = 0; 786 chan->connection = connection; 787 chan->packet_handler = packet_handler; 788 chan->remote_mtu = L2CAP_MINIMAL_MTU; 789 chan->local_mtu = mtu; 790 chan->packets_granted = 0; 791 792 // set initial state 793 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 794 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 795 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 796 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 797 chan->required_security_level = LEVEL_0; 798 799 // add to connections list 800 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 801 802 // check if hci connection is already usable 803 hci_connection_t * conn = hci_connection_for_bd_addr_and_type((bd_addr_t*)address, BD_ADDR_TYPE_CLASSIC); 804 if (conn){ 805 log_info("l2cap_create_channel_internal, hci connection already exists"); 806 l2cap_handle_connection_complete(conn->con_handle, chan); 807 // check ir remote supported fearures are already received 808 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 809 l2cap_handle_remote_supported_features_received(chan); 810 } 811 } 812 813 l2cap_run(); 814 } 815 816 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 817 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 818 // find channel for local_cid 819 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 820 if (channel) { 821 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 822 } 823 // process 824 l2cap_run(); 825 } 826 827 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 828 linked_list_iterator_t it; 829 linked_list_iterator_init(&it, &l2cap_channels); 830 while (linked_list_iterator_has_next(&it)){ 831 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 832 if ( BD_ADDR_CMP( channel->address, address) != 0) continue; 833 // channel for this address found 834 switch (channel->state){ 835 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 836 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 837 // failure, forward error code 838 l2cap_emit_channel_opened(channel, status); 839 // discard channel 840 l2cap_stop_rtx(channel); 841 linked_list_iterator_remove(&it); 842 btstack_memory_l2cap_channel_free(channel); 843 break; 844 default: 845 break; 846 } 847 } 848 } 849 850 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 851 linked_list_iterator_t it; 852 linked_list_iterator_init(&it, &l2cap_channels); 853 while (linked_list_iterator_has_next(&it)){ 854 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 855 if ( ! BD_ADDR_CMP( channel->address, address) ){ 856 l2cap_handle_connection_complete(handle, channel); 857 } 858 } 859 // process 860 l2cap_run(); 861 } 862 863 void l2cap_event_handler(uint8_t *packet, uint16_t size){ 864 865 bd_addr_t address; 866 hci_con_handle_t handle; 867 linked_list_iterator_t it; 868 int hci_con_used; 869 870 switch(packet[0]){ 871 872 // handle connection complete events 873 case HCI_EVENT_CONNECTION_COMPLETE: 874 bt_flip_addr(address, &packet[5]); 875 if (packet[2] == 0){ 876 handle = READ_BT_16(packet, 3); 877 l2cap_handle_connection_success_for_addr(address, handle); 878 } else { 879 l2cap_handle_connection_failed_for_addr(address, packet[2]); 880 } 881 break; 882 883 // handle successful create connection cancel command 884 case HCI_EVENT_COMMAND_COMPLETE: 885 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 886 if (packet[5] == 0){ 887 bt_flip_addr(address, &packet[6]); 888 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 889 l2cap_handle_connection_failed_for_addr(address, 0x16); 890 } 891 } 892 l2cap_run(); // try sending signaling packets first 893 break; 894 895 case HCI_EVENT_COMMAND_STATUS: 896 l2cap_run(); // try sending signaling packets first 897 break; 898 899 // handle disconnection complete events 900 case HCI_EVENT_DISCONNECTION_COMPLETE: 901 // send l2cap disconnect events for all channels on this handle and free them 902 handle = READ_BT_16(packet, 3); 903 linked_list_iterator_init(&it, &l2cap_channels); 904 while (linked_list_iterator_has_next(&it)){ 905 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 906 if (channel->handle != handle) continue; 907 l2cap_emit_channel_closed(channel); 908 l2cap_stop_rtx(channel); 909 linked_list_iterator_remove(&it); 910 btstack_memory_l2cap_channel_free(channel); 911 } 912 break; 913 914 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 915 l2cap_run(); // try sending signaling packets first 916 l2cap_hand_out_credits(); 917 break; 918 919 // HCI Connection Timeouts 920 case L2CAP_EVENT_TIMEOUT_CHECK: 921 handle = READ_BT_16(packet, 2); 922 if (hci_authentication_active_for_handle(handle)) break; 923 hci_con_used = 0; 924 linked_list_iterator_init(&it, &l2cap_channels); 925 while (linked_list_iterator_has_next(&it)){ 926 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 927 if (channel->handle != handle) continue; 928 hci_con_used = 1; 929 break; 930 } 931 if (hci_con_used) break; 932 if (!hci_can_send_command_packet_now()) break; 933 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 934 break; 935 936 case DAEMON_EVENT_HCI_PACKET_SENT: 937 linked_list_iterator_init(&it, &l2cap_channels); 938 while (linked_list_iterator_has_next(&it)){ 939 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 940 if (!channel->packet_handler) continue; 941 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 942 } 943 if (attribute_protocol_packet_handler) { 944 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 945 } 946 if (security_protocol_packet_handler) { 947 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 948 } 949 break; 950 951 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 952 handle = READ_BT_16(packet, 3); 953 linked_list_iterator_init(&it, &l2cap_channels); 954 while (linked_list_iterator_has_next(&it)){ 955 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 956 if (channel->handle != handle) continue; 957 l2cap_handle_remote_supported_features_received(channel); 958 break; 959 } 960 break; 961 962 case GAP_SECURITY_LEVEL: 963 handle = READ_BT_16(packet, 2); 964 log_info("l2cap - security level update"); 965 linked_list_iterator_init(&it, &l2cap_channels); 966 while (linked_list_iterator_has_next(&it)){ 967 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 968 if (channel->handle != handle) continue; 969 970 log_info("l2cap - state %u", channel->state); 971 972 gap_security_level_t actual_level = packet[4]; 973 gap_security_level_t required_level = channel->required_security_level; 974 975 switch (channel->state){ 976 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 977 if (actual_level >= required_level){ 978 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 979 l2cap_emit_connection_request(channel); 980 } else { 981 channel->reason = 0x03; // security block 982 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 983 } 984 break; 985 986 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 987 if (actual_level >= required_level){ 988 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 989 } else { 990 // disconnnect, authentication not good enough 991 hci_disconnect_security_block(handle); 992 } 993 break; 994 995 default: 996 break; 997 } 998 } 999 break; 1000 1001 default: 1002 break; 1003 } 1004 1005 // pass on: main packet handler, att and sm packet handlers 1006 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 1007 if (attribute_protocol_packet_handler){ 1008 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 1009 } 1010 if (security_protocol_packet_handler) { 1011 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 1012 } 1013 1014 l2cap_run(); 1015 } 1016 1017 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 1018 channel->remote_sig_id = identifier; 1019 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 1020 l2cap_run(); 1021 } 1022 1023 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 1024 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 1025 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 1026 signaling_responses[signaling_responses_pending].handle = handle; 1027 signaling_responses[signaling_responses_pending].code = code; 1028 signaling_responses[signaling_responses_pending].sig_id = sig_id; 1029 signaling_responses[signaling_responses_pending].data = data; 1030 signaling_responses_pending++; 1031 l2cap_run(); 1032 } 1033 } 1034 1035 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 1036 1037 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x", handle, psm, source_cid); 1038 l2cap_service_t *service = l2cap_get_service(psm); 1039 if (!service) { 1040 // 0x0002 PSM not supported 1041 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 1042 return; 1043 } 1044 1045 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 1046 if (!hci_connection) { 1047 // 1048 log_error("no hci_connection for handle %u", handle); 1049 return; 1050 } 1051 1052 // reject connection (0x03 security block) and disconnect if both have SSP, connection is not encrypted and PSM != SDP 1053 if ( hci_ssp_supported_on_both_sides(handle) 1054 && gap_security_level(handle) == LEVEL_0 1055 && !l2cap_security_level_0_allowed_for_PSM(psm)){ 1056 1057 // 0x0003 Security Block 1058 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0003); 1059 return; 1060 } 1061 1062 1063 // alloc structure 1064 // log_info("l2cap_handle_connection_request register channel"); 1065 l2cap_channel_t * channel = btstack_memory_l2cap_channel_get(); 1066 if (!channel){ 1067 // 0x0004 No resources available 1068 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 1069 return; 1070 } 1071 1072 // fill in 1073 BD_ADDR_COPY(channel->address, hci_connection->address); 1074 channel->psm = psm; 1075 channel->handle = handle; 1076 channel->connection = service->connection; 1077 channel->packet_handler = service->packet_handler; 1078 channel->local_cid = l2cap_next_local_cid(); 1079 channel->remote_cid = source_cid; 1080 channel->local_mtu = service->mtu; 1081 channel->remote_mtu = L2CAP_DEFAULT_MTU; 1082 channel->packets_granted = 0; 1083 channel->remote_sig_id = sig_id; 1084 channel->required_security_level = service->required_security_level; 1085 1086 // limit local mtu to max acl packet length - l2cap header 1087 if (channel->local_mtu > l2cap_max_mtu()) { 1088 channel->local_mtu = l2cap_max_mtu(); 1089 } 1090 1091 // set initial state 1092 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1093 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 1094 1095 // add to connections list 1096 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 1097 1098 // assert security requirements 1099 gap_request_security_level(handle, channel->required_security_level); 1100 } 1101 1102 void l2cap_accept_connection_internal(uint16_t local_cid){ 1103 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1104 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1105 if (!channel) { 1106 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 1107 return; 1108 } 1109 1110 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1111 1112 // process 1113 l2cap_run(); 1114 } 1115 1116 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 1117 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); 1118 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1119 if (!channel) { 1120 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 1121 return; 1122 } 1123 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1124 channel->reason = reason; 1125 l2cap_run(); 1126 } 1127 1128 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1129 1130 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1131 1132 uint16_t flags = READ_BT_16(command, 6); 1133 if (flags & 1) { 1134 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1135 } 1136 1137 // accept the other's configuration options 1138 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1139 uint16_t pos = 8; 1140 while (pos < end_pos){ 1141 uint8_t option_hint = command[pos] >> 7; 1142 uint8_t option_type = command[pos] & 0x7f; 1143 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1144 pos++; 1145 uint8_t length = command[pos++]; 1146 // MTU { type(8): 1, len(8):2, MTU(16) } 1147 if (option_type == 1 && length == 2){ 1148 channel->remote_mtu = READ_BT_16(command, pos); 1149 // log_info("l2cap cid 0x%02x, remote mtu %u", channel->local_cid, channel->remote_mtu); 1150 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1151 } 1152 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1153 if (option_type == 2 && length == 2){ 1154 channel->flush_timeout = READ_BT_16(command, pos); 1155 } 1156 // check for unknown options 1157 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1158 log_info("l2cap cid %u, unknown options", channel->local_cid); 1159 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1160 } 1161 pos += length; 1162 } 1163 } 1164 1165 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1166 // log_info("l2cap_channel_ready_for_open 0x%02x", channel->state_var); 1167 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1168 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1169 return 1; 1170 } 1171 1172 1173 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1174 1175 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1176 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1177 uint16_t result = 0; 1178 1179 log_info("L2CAP signaling handler code %u, state %u", code, channel->state); 1180 1181 // handle DISCONNECT REQUESTS seperately 1182 if (code == DISCONNECTION_REQUEST){ 1183 switch (channel->state){ 1184 case L2CAP_STATE_CONFIG: 1185 case L2CAP_STATE_OPEN: 1186 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1187 case L2CAP_STATE_WAIT_DISCONNECT: 1188 l2cap_handle_disconnect_request(channel, identifier); 1189 break; 1190 1191 default: 1192 // ignore in other states 1193 break; 1194 } 1195 return; 1196 } 1197 1198 // @STATEMACHINE(l2cap) 1199 switch (channel->state) { 1200 1201 case L2CAP_STATE_WAIT_CONNECT_RSP: 1202 switch (code){ 1203 case CONNECTION_RESPONSE: 1204 l2cap_stop_rtx(channel); 1205 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1206 switch (result) { 1207 case 0: 1208 // successful connection 1209 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1210 channel->state = L2CAP_STATE_CONFIG; 1211 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1212 break; 1213 case 1: 1214 // connection pending. get some coffee, but start the ERTX 1215 l2cap_start_ertx(channel); 1216 break; 1217 default: 1218 // channel closed 1219 channel->state = L2CAP_STATE_CLOSED; 1220 // map l2cap connection response result to BTstack status enumeration 1221 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1222 1223 // drop link key if security block 1224 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1225 hci_drop_link_key_for_bd_addr(&channel->address); 1226 } 1227 1228 // discard channel 1229 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1230 btstack_memory_l2cap_channel_free(channel); 1231 break; 1232 } 1233 break; 1234 1235 default: 1236 //@TODO: implement other signaling packets 1237 break; 1238 } 1239 break; 1240 1241 case L2CAP_STATE_CONFIG: 1242 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1243 switch (code) { 1244 case CONFIGURE_REQUEST: 1245 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1246 l2cap_signaling_handle_configure_request(channel, command); 1247 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1248 // only done if continuation not set 1249 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1250 } 1251 break; 1252 case CONFIGURE_RESPONSE: 1253 l2cap_stop_rtx(channel); 1254 switch (result){ 1255 case 0: // success 1256 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1257 break; 1258 case 4: // pending 1259 l2cap_start_ertx(channel); 1260 break; 1261 default: 1262 // retry on negative result 1263 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1264 break; 1265 } 1266 break; 1267 default: 1268 break; 1269 } 1270 if (l2cap_channel_ready_for_open(channel)){ 1271 // for open: 1272 channel->state = L2CAP_STATE_OPEN; 1273 l2cap_emit_channel_opened(channel, 0); 1274 l2cap_emit_credits(channel, 1); 1275 } 1276 break; 1277 1278 case L2CAP_STATE_WAIT_DISCONNECT: 1279 switch (code) { 1280 case DISCONNECTION_RESPONSE: 1281 l2cap_finialize_channel_close(channel); 1282 break; 1283 default: 1284 //@TODO: implement other signaling packets 1285 break; 1286 } 1287 break; 1288 1289 case L2CAP_STATE_CLOSED: 1290 // @TODO handle incoming requests 1291 break; 1292 1293 case L2CAP_STATE_OPEN: 1294 //@TODO: implement other signaling packets, e.g. re-configure 1295 break; 1296 default: 1297 break; 1298 } 1299 // log_info("new state %u", channel->state); 1300 } 1301 1302 1303 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1304 1305 // get code, signalind identifier and command len 1306 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1307 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1308 1309 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1310 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1311 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1312 return; 1313 } 1314 1315 // general commands without an assigned channel 1316 switch(code) { 1317 1318 case CONNECTION_REQUEST: { 1319 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1320 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1321 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1322 return; 1323 } 1324 1325 case ECHO_REQUEST: 1326 l2cap_register_signaling_response(handle, code, sig_id, 0); 1327 return; 1328 1329 case INFORMATION_REQUEST: { 1330 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1331 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1332 return; 1333 } 1334 1335 default: 1336 break; 1337 } 1338 1339 1340 // Get potential destination CID 1341 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1342 1343 // Find channel for this sig_id and connection handle 1344 linked_list_iterator_t it; 1345 linked_list_iterator_init(&it, &l2cap_channels); 1346 while (linked_list_iterator_has_next(&it)){ 1347 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 1348 if (channel->handle != handle) continue; 1349 if (code & 1) { 1350 // match odd commands (responses) by previous signaling identifier 1351 if (channel->local_sig_id == sig_id) { 1352 l2cap_signaling_handler_channel(channel, command); 1353 break; 1354 } 1355 } else { 1356 // match even commands (requests) by local channel id 1357 if (channel->local_cid == dest_cid) { 1358 l2cap_signaling_handler_channel(channel, command); 1359 break; 1360 } 1361 } 1362 } 1363 } 1364 1365 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 1366 1367 // Get Channel ID 1368 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1369 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1370 1371 switch (channel_id) { 1372 1373 case L2CAP_CID_SIGNALING: { 1374 1375 uint16_t command_offset = 8; 1376 while (command_offset < size) { 1377 1378 // handle signaling commands 1379 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1380 1381 // increment command_offset 1382 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1383 } 1384 break; 1385 } 1386 1387 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1388 if (attribute_protocol_packet_handler) { 1389 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1390 } 1391 break; 1392 1393 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1394 if (security_protocol_packet_handler) { 1395 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1396 } 1397 break; 1398 1399 case L2CAP_CID_SIGNALING_LE: { 1400 switch (packet[8]){ 1401 case CONNECTION_PARAMETER_UPDATE_RESPONSE: { 1402 uint16_t result = READ_BT_16(packet, 12); 1403 l2cap_emit_connection_parameter_update_response(handle, result); 1404 break; 1405 } 1406 case CONNECTION_PARAMETER_UPDATE_REQUEST: { 1407 uint8_t event[10]; 1408 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 1409 event[1] = 8; 1410 memcpy(&event[2], &packet[12], 8); 1411 1412 hci_connection_t * connection = hci_connection_for_handle(handle); 1413 if (connection){ 1414 int update_parameter = 1; 1415 le_connection_parameter_range_t existing_range = gap_le_get_connection_parameter_range(); 1416 uint16_t le_conn_interval_min = READ_BT_16(packet,12); 1417 uint16_t le_conn_interval_max = READ_BT_16(packet,14); 1418 uint16_t le_conn_latency = READ_BT_16(packet,16); 1419 uint16_t le_supervision_timeout = READ_BT_16(packet,18); 1420 1421 if (le_conn_interval_min < existing_range.le_conn_interval_min) update_parameter = 0; 1422 if (le_conn_interval_max > existing_range.le_conn_interval_max) update_parameter = 0; 1423 1424 if (le_conn_latency < existing_range.le_conn_latency_min) update_parameter = 0; 1425 if (le_conn_latency > existing_range.le_conn_latency_max) update_parameter = 0; 1426 1427 if (le_supervision_timeout < existing_range.le_supervision_timeout_min) update_parameter = 0; 1428 if (le_supervision_timeout > existing_range.le_supervision_timeout_max) update_parameter = 0; 1429 1430 if (update_parameter){ 1431 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_SEND_RESPONSE; 1432 connection->le_conn_interval_min = le_conn_interval_min; 1433 connection->le_conn_interval_max = le_conn_interval_max; 1434 connection->le_conn_latency = le_conn_latency; 1435 connection->le_supervision_timeout = le_supervision_timeout; 1436 } else { 1437 connection->le_con_parameter_update_state = CON_PARAMETER_UPDATE_DENY; 1438 } 1439 } 1440 1441 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1442 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, event, sizeof(event)); 1443 1444 break; 1445 } 1446 default: { 1447 uint8_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1448 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1449 break; 1450 } 1451 } 1452 break; 1453 } 1454 1455 default: { 1456 // Find channel for this channel_id and connection handle 1457 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1458 if (channel) { 1459 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1460 } 1461 break; 1462 } 1463 } 1464 } 1465 1466 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1467 switch (packet_type) { 1468 case HCI_EVENT_PACKET: 1469 l2cap_event_handler(packet, size); 1470 break; 1471 case HCI_ACL_DATA_PACKET: 1472 l2cap_acl_handler(packet, size); 1473 break; 1474 default: 1475 break; 1476 } 1477 l2cap_run(); 1478 } 1479 1480 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1481 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1482 channel->state = L2CAP_STATE_CLOSED; 1483 l2cap_emit_channel_closed(channel); 1484 // discard channel 1485 l2cap_stop_rtx(channel); 1486 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1487 btstack_memory_l2cap_channel_free(channel); 1488 } 1489 1490 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1491 linked_list_iterator_t it; 1492 linked_list_iterator_init(&it, &l2cap_services); 1493 while (linked_list_iterator_has_next(&it)){ 1494 l2cap_service_t * service = (l2cap_service_t *) linked_list_iterator_next(&it); 1495 if ( service->psm == psm){ 1496 return service; 1497 }; 1498 } 1499 return NULL; 1500 } 1501 1502 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){ 1503 1504 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u connection %p", psm, mtu, connection); 1505 1506 // check for alread registered psm 1507 // TODO: emit error event 1508 l2cap_service_t *service = l2cap_get_service(psm); 1509 if (service) { 1510 log_error("l2cap_register_service_internal: PSM %u already registered", psm); 1511 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1512 return; 1513 } 1514 1515 // alloc structure 1516 // TODO: emit error event 1517 service = btstack_memory_l2cap_service_get(); 1518 if (!service) { 1519 log_error("l2cap_register_service_internal: no memory for l2cap_service_t"); 1520 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1521 return; 1522 } 1523 1524 // fill in 1525 service->psm = psm; 1526 service->mtu = mtu; 1527 service->connection = connection; 1528 service->packet_handler = packet_handler; 1529 service->required_security_level = security_level; 1530 1531 // add to services list 1532 linked_list_add(&l2cap_services, (linked_item_t *) service); 1533 1534 // enable page scan 1535 hci_connectable_control(1); 1536 1537 // done 1538 l2cap_emit_service_registered(connection, 0, psm); 1539 } 1540 1541 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1542 1543 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1544 1545 l2cap_service_t *service = l2cap_get_service(psm); 1546 if (!service) return; 1547 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1548 btstack_memory_l2cap_service_free(service); 1549 1550 // disable page scan when no services registered 1551 if (!linked_list_empty(&l2cap_services)) return; 1552 hci_connectable_control(0); 1553 } 1554 1555 1556 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1557 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1558 switch(channel_id){ 1559 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1560 attribute_protocol_packet_handler = packet_handler; 1561 break; 1562 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1563 security_protocol_packet_handler = packet_handler; 1564 break; 1565 } 1566 } 1567 1568 #ifdef HAVE_BLE 1569 1570 // Request LE connection parameter update 1571 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){ 1572 if (!hci_can_send_acl_packet_now(handle)){ 1573 log_info("l2cap_send_signaling_packet, cannot send"); 1574 return BTSTACK_ACL_BUFFERS_FULL; 1575 } 1576 // log_info("l2cap_send_signaling_packet type %u", cmd); 1577 hci_reserve_packet_buffer(); 1578 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1579 uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); 1580 return hci_send_acl_packet_buffer(len); 1581 } 1582 #endif 1583 1584