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, 19, 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)(NULL, 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()) 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 int l2cap_can_send_connectionless_packet_now(void){ 251 // TODO provide real handle 252 return hci_can_send_acl_packet_now(0x1234); 253 } 254 255 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 256 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 257 if (channel) { 258 return channel->remote_mtu; 259 } 260 return 0; 261 } 262 263 static l2cap_channel_t * l2cap_channel_for_rtx_timer(timer_source_t * ts){ 264 linked_list_iterator_t it; 265 linked_list_iterator_init(&it, &l2cap_channels); 266 while (linked_list_iterator_has_next(&it)){ 267 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 268 if ( &channel->rtx == ts) { 269 return channel; 270 } 271 } 272 return NULL; 273 } 274 275 static void l2cap_rtx_timeout(timer_source_t * ts){ 276 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 277 if (!ts) return; 278 279 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 280 281 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 282 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 283 // notify client 284 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 285 286 // discard channel 287 // no need to stop timer here, it is removed from list during timer callback 288 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 289 btstack_memory_l2cap_channel_free(channel); 290 } 291 292 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 293 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 294 run_loop_remove_timer(&channel->rtx); 295 } 296 297 static void l2cap_start_rtx(l2cap_channel_t * channel){ 298 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 299 l2cap_stop_rtx(channel); 300 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 301 run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 302 run_loop_add_timer(&channel->rtx); 303 } 304 305 static void l2cap_start_ertx(l2cap_channel_t * channel){ 306 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 307 l2cap_stop_rtx(channel); 308 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 309 run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 310 run_loop_add_timer(&channel->rtx); 311 } 312 313 void l2cap_require_security_level_2_for_outgoing_sdp(){ 314 require_security_level2_for_outgoing_sdp = 1; 315 } 316 317 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 318 return (psm == PSM_SDP) && (!require_security_level2_for_outgoing_sdp); 319 } 320 321 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 322 323 if (!hci_can_send_acl_packet_now(handle)){ 324 log_info("l2cap_send_signaling_packet, cannot send\n"); 325 return BTSTACK_ACL_BUFFERS_FULL; 326 } 327 328 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 329 hci_reserve_packet_buffer(); 330 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 331 va_list argptr; 332 va_start(argptr, identifier); 333 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 334 va_end(argptr); 335 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 336 return hci_send_acl_packet_buffer(len); 337 } 338 339 #ifdef HAVE_BLE 340 int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 341 342 if (!hci_can_send_acl_packet_now(handle)){ 343 log_info("l2cap_send_signaling_packet, cannot send\n"); 344 return BTSTACK_ACL_BUFFERS_FULL; 345 } 346 347 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 348 hci_reserve_packet_buffer(); 349 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 350 va_list argptr; 351 va_start(argptr, identifier); 352 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 353 va_end(argptr); 354 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 355 return hci_send_acl_packet_buffer(len); 356 } 357 #endif 358 359 uint8_t *l2cap_get_outgoing_buffer(void){ 360 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 361 } 362 363 int l2cap_reserve_packet_buffer(void){ 364 return hci_reserve_packet_buffer(); 365 } 366 367 void l2cap_release_packet_buffer(void){ 368 hci_release_packet_buffer(); 369 } 370 371 372 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 373 374 if (!hci_is_packet_buffer_reserved()){ 375 log_error("l2cap_send_prepared called without reserving packet first"); 376 return BTSTACK_ACL_BUFFERS_FULL; 377 } 378 379 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 380 if (!channel) { 381 log_error("l2cap_send_prepared no channel for cid 0x%02x\n", local_cid); 382 return -1; // TODO: define error 383 } 384 385 if (channel->packets_granted == 0){ 386 log_error("l2cap_send_prepared cid 0x%02x, no credits!\n", local_cid); 387 return -1; // TODO: define error 388 } 389 390 if (!hci_can_send_prepared_acl_packet_now(channel->handle)){ 391 log_info("l2cap_send_prepared cid 0x%02x, cannot send\n", local_cid); 392 return BTSTACK_ACL_BUFFERS_FULL; 393 } 394 395 --channel->packets_granted; 396 397 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used, credits left %u;\n", 398 local_cid, channel->handle, channel->packets_granted); 399 400 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 401 402 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 403 404 // 0 - Connection handle : PB=pb : BC=00 405 bt_store_16(acl_buffer, 0, channel->handle | (pb << 12) | (0 << 14)); 406 // 2 - ACL length 407 bt_store_16(acl_buffer, 2, len + 4); 408 // 4 - L2CAP packet length 409 bt_store_16(acl_buffer, 4, len + 0); 410 // 6 - L2CAP channel DEST 411 bt_store_16(acl_buffer, 6, channel->remote_cid); 412 // send 413 int err = hci_send_acl_packet_buffer(len+8); 414 415 l2cap_hand_out_credits(); 416 417 return err; 418 } 419 420 int l2cap_send_prepared_connectionless(uint16_t handle, uint16_t cid, uint16_t len){ 421 422 if (!hci_is_packet_buffer_reserved()){ 423 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 424 return BTSTACK_ACL_BUFFERS_FULL; 425 } 426 427 if (!hci_can_send_prepared_acl_packet_now(handle)){ 428 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send\n", handle, cid); 429 return BTSTACK_ACL_BUFFERS_FULL; 430 } 431 432 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x\n", handle, cid); 433 434 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 435 436 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 437 438 // 0 - Connection handle : PB=pb : BC=00 439 bt_store_16(acl_buffer, 0, handle | (pb << 12) | (0 << 14)); 440 // 2 - ACL length 441 bt_store_16(acl_buffer, 2, len + 4); 442 // 4 - L2CAP packet length 443 bt_store_16(acl_buffer, 4, len + 0); 444 // 6 - L2CAP channel DEST 445 bt_store_16(acl_buffer, 6, cid); 446 // send 447 int err = hci_send_acl_packet_buffer(len+8); 448 449 l2cap_hand_out_credits(); 450 451 return err; 452 } 453 454 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 455 456 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 457 if (!channel) { 458 log_error("l2cap_send_internal no channel for cid 0x%02x\n", local_cid); 459 return -1; // TODO: define error 460 } 461 462 if (!hci_can_send_acl_packet_now(channel->handle)){ 463 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", local_cid); 464 return BTSTACK_ACL_BUFFERS_FULL; 465 } 466 467 hci_reserve_packet_buffer(); 468 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 469 470 memcpy(&acl_buffer[8], data, len); 471 472 return l2cap_send_prepared(local_cid, len); 473 } 474 475 int l2cap_send_connectionless(uint16_t handle, uint16_t cid, uint8_t *data, uint16_t len){ 476 477 if (!hci_can_send_acl_packet_now(handle)){ 478 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", cid); 479 return BTSTACK_ACL_BUFFERS_FULL; 480 } 481 482 hci_reserve_packet_buffer(); 483 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 484 485 memcpy(&acl_buffer[8], data, len); 486 487 return l2cap_send_prepared_connectionless(handle, cid, len); 488 } 489 490 int l2cap_send_echo_request(uint16_t handle, uint8_t *data, uint16_t len){ 491 return l2cap_send_signaling_packet(handle, ECHO_REQUEST, 0x77, len, data); 492 } 493 494 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 495 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 496 } 497 498 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 499 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 500 } 501 502 503 504 // MARK: L2CAP_RUN 505 // process outstanding signaling tasks 506 void l2cap_run(void){ 507 508 // check pending signaling responses 509 while (signaling_responses_pending){ 510 511 hci_con_handle_t handle = signaling_responses[0].handle; 512 513 if (!hci_can_send_acl_packet_now(handle)) break; 514 515 uint8_t sig_id = signaling_responses[0].sig_id; 516 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 517 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 518 519 switch (signaling_responses[0].code){ 520 case CONNECTION_REQUEST: 521 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 522 // also disconnect if result is 0x0003 - security blocked 523 hci_disconnect_security_block(handle); 524 break; 525 case ECHO_REQUEST: 526 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 527 break; 528 case INFORMATION_REQUEST: 529 switch (infoType){ 530 case 1: { // Connectionless MTU 531 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 532 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 533 break; 534 } 535 case 2: { // Extended Features Supported 536 // extended features request supported, only supporing fixed channel map 537 uint32_t features = 0x80; 538 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 539 break; 540 } 541 case 3: { // Fixed Channels Supported 542 uint8_t map[8]; 543 memset(map, 0, 8); 544 map[0] = 0x01; // L2CAP Signaling Channel 545 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 546 break; 547 } 548 default: 549 // all other types are not supported 550 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 551 break; 552 } 553 break; 554 case COMMAND_REJECT: 555 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 556 #ifdef HAVE_BLE 557 case COMMAND_REJECT_LE: 558 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 559 break; 560 #endif 561 default: 562 // should not happen 563 break; 564 } 565 566 // remove first item 567 signaling_responses_pending--; 568 int i; 569 for (i=0; i < signaling_responses_pending; i++){ 570 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 571 } 572 } 573 574 uint8_t config_options[4]; 575 linked_list_iterator_t it; 576 linked_list_iterator_init(&it, &l2cap_channels); 577 while (linked_list_iterator_has_next(&it)){ 578 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 579 580 if (!hci_can_send_command_packet_now()) break; 581 if (!hci_can_send_acl_packet_now(channel->handle)) break; 582 583 // log_info("l2cap_run: state %u, var 0x%02x\n", channel->state, channel->state_var); 584 585 switch (channel->state){ 586 587 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 588 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 589 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 590 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 591 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 592 } 593 break; 594 595 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 596 // send connection request - set state first 597 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 598 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 599 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 600 break; 601 602 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 603 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 604 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 605 l2cap_stop_rtx(channel); 606 linked_list_iterator_remove(&it); 607 btstack_memory_l2cap_channel_free(channel); 608 break; 609 610 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 611 channel->state = L2CAP_STATE_CONFIG; 612 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 613 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 614 break; 615 616 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 617 // success, start l2cap handshake 618 channel->local_sig_id = l2cap_next_sig_id(); 619 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 620 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 621 l2cap_start_rtx(channel); 622 break; 623 624 case L2CAP_STATE_CONFIG: 625 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 626 uint16_t flags = 0; 627 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 628 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 629 flags = 1; 630 } else { 631 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 632 } 633 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 634 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 635 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 636 config_options[0] = 1; // MTU 637 config_options[1] = 2; // len param 638 bt_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 639 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 640 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 641 } else { 642 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 643 } 644 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 645 } 646 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 647 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 648 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 649 channel->local_sig_id = l2cap_next_sig_id(); 650 config_options[0] = 1; // MTU 651 config_options[1] = 2; // len param 652 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 653 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 654 l2cap_start_rtx(channel); 655 } 656 if (l2cap_channel_ready_for_open(channel)){ 657 channel->state = L2CAP_STATE_OPEN; 658 l2cap_emit_channel_opened(channel, 0); // success 659 l2cap_emit_credits(channel, 1); 660 } 661 break; 662 663 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 664 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 665 // 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 :) 666 l2cap_finialize_channel_close(channel); // -- remove from list 667 break; 668 669 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 670 channel->local_sig_id = l2cap_next_sig_id(); 671 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 672 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 673 break; 674 default: 675 break; 676 } 677 } 678 } 679 680 uint16_t l2cap_max_mtu(void){ 681 return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE; 682 } 683 684 static void l2cap_handle_connection_complete(uint16_t handle, l2cap_channel_t * channel){ 685 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 686 log_info("l2cap_handle_connection_complete expected state"); 687 // success, start l2cap handshake 688 channel->handle = handle; 689 channel->local_cid = l2cap_next_local_cid(); 690 // check remote SSP feature first 691 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 692 } 693 } 694 695 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 696 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 697 698 // we have been waiting for remote supported features, if both support SSP, 699 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)); 700 if (hci_ssp_supported_on_both_sides(channel->handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 701 // request security level 2 702 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 703 gap_request_security_level(channel->handle, LEVEL_2); 704 return; 705 } 706 // fine, go ahead 707 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 708 } 709 710 // open outgoing L2CAP channel 711 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 712 bd_addr_t address, uint16_t psm, uint16_t mtu){ 713 714 log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 715 716 // alloc structure 717 l2cap_channel_t * chan = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 718 if (!chan) { 719 // emit error event 720 l2cap_channel_t dummy_channel; 721 BD_ADDR_COPY(dummy_channel.address, address); 722 dummy_channel.psm = psm; 723 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 724 return; 725 } 726 // limit local mtu to max acl packet length 727 if (mtu > l2cap_max_mtu()) { 728 mtu = l2cap_max_mtu(); 729 } 730 731 // fill in 732 BD_ADDR_COPY(chan->address, address); 733 chan->psm = psm; 734 chan->handle = 0; 735 chan->connection = connection; 736 chan->packet_handler = packet_handler; 737 chan->remote_mtu = L2CAP_MINIMAL_MTU; 738 chan->local_mtu = mtu; 739 chan->packets_granted = 0; 740 741 // set initial state 742 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 743 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 744 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 745 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 746 chan->required_security_level = LEVEL_0; 747 748 // add to connections list 749 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 750 751 // check if hci connection is already usable 752 hci_connection_t * conn = hci_connection_for_bd_addr_and_type((bd_addr_t*)address, BD_ADDR_TYPE_CLASSIC); 753 if (conn){ 754 log_info("l2cap_create_channel_internal, hci connection already exists"); 755 l2cap_handle_connection_complete(conn->con_handle, chan); 756 // check ir remote supported fearures are already received 757 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 758 l2cap_handle_remote_supported_features_received(chan); 759 } 760 } 761 762 l2cap_run(); 763 } 764 765 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 766 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 767 // find channel for local_cid 768 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 769 if (channel) { 770 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 771 } 772 // process 773 l2cap_run(); 774 } 775 776 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 777 linked_list_iterator_t it; 778 linked_list_iterator_init(&it, &l2cap_channels); 779 while (linked_list_iterator_has_next(&it)){ 780 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 781 if ( BD_ADDR_CMP( channel->address, address) != 0) continue; 782 // channel for this address found 783 switch (channel->state){ 784 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 785 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 786 // failure, forward error code 787 l2cap_emit_channel_opened(channel, status); 788 // discard channel 789 l2cap_stop_rtx(channel); 790 linked_list_iterator_remove(&it); 791 btstack_memory_l2cap_channel_free(channel); 792 break; 793 default: 794 break; 795 } 796 } 797 } 798 799 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 800 linked_list_iterator_t it; 801 linked_list_iterator_init(&it, &l2cap_channels); 802 while (linked_list_iterator_has_next(&it)){ 803 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 804 if ( ! BD_ADDR_CMP( channel->address, address) ){ 805 l2cap_handle_connection_complete(handle, channel); 806 } 807 } 808 // process 809 l2cap_run(); 810 } 811 812 void l2cap_event_handler(uint8_t *packet, uint16_t size){ 813 814 bd_addr_t address; 815 hci_con_handle_t handle; 816 linked_list_iterator_t it; 817 int hci_con_used; 818 819 switch(packet[0]){ 820 821 // handle connection complete events 822 case HCI_EVENT_CONNECTION_COMPLETE: 823 bt_flip_addr(address, &packet[5]); 824 if (packet[2] == 0){ 825 handle = READ_BT_16(packet, 3); 826 l2cap_handle_connection_success_for_addr(address, handle); 827 } else { 828 l2cap_handle_connection_failed_for_addr(address, packet[2]); 829 } 830 break; 831 832 // handle successful create connection cancel command 833 case HCI_EVENT_COMMAND_COMPLETE: 834 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 835 if (packet[5] == 0){ 836 bt_flip_addr(address, &packet[6]); 837 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 838 l2cap_handle_connection_failed_for_addr(address, 0x16); 839 } 840 } 841 l2cap_run(); // try sending signaling packets first 842 break; 843 844 case HCI_EVENT_COMMAND_STATUS: 845 l2cap_run(); // try sending signaling packets first 846 break; 847 848 // handle disconnection complete events 849 case HCI_EVENT_DISCONNECTION_COMPLETE: 850 // send l2cap disconnect events for all channels on this handle and free them 851 handle = READ_BT_16(packet, 3); 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 (channel->handle != handle) continue; 856 l2cap_emit_channel_closed(channel); 857 l2cap_stop_rtx(channel); 858 linked_list_iterator_remove(&it); 859 btstack_memory_l2cap_channel_free(channel); 860 } 861 break; 862 863 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 864 l2cap_run(); // try sending signaling packets first 865 l2cap_hand_out_credits(); 866 break; 867 868 // HCI Connection Timeouts 869 case L2CAP_EVENT_TIMEOUT_CHECK: 870 handle = READ_BT_16(packet, 2); 871 if (hci_authentication_active_for_handle(handle)) break; 872 hci_con_used = 0; 873 linked_list_iterator_init(&it, &l2cap_channels); 874 while (linked_list_iterator_has_next(&it)){ 875 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 876 if (channel->handle != handle) continue; 877 hci_con_used = 1; 878 break; 879 } 880 if (hci_con_used) break; 881 if (!hci_can_send_command_packet_now()) break; 882 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 883 break; 884 885 case DAEMON_EVENT_HCI_PACKET_SENT: 886 linked_list_iterator_init(&it, &l2cap_channels); 887 while (linked_list_iterator_has_next(&it)){ 888 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 889 if (!channel->packet_handler) continue; 890 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 891 } 892 if (attribute_protocol_packet_handler) { 893 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 894 } 895 if (security_protocol_packet_handler) { 896 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 897 } 898 break; 899 900 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 901 handle = READ_BT_16(packet, 3); 902 linked_list_iterator_init(&it, &l2cap_channels); 903 while (linked_list_iterator_has_next(&it)){ 904 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 905 if (channel->handle != handle) continue; 906 l2cap_handle_remote_supported_features_received(channel); 907 break; 908 } 909 break; 910 911 case GAP_SECURITY_LEVEL: 912 handle = READ_BT_16(packet, 2); 913 log_info("l2cap - security level update"); 914 linked_list_iterator_init(&it, &l2cap_channels); 915 while (linked_list_iterator_has_next(&it)){ 916 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 917 if (channel->handle != handle) continue; 918 919 log_info("l2cap - state %u", channel->state); 920 921 gap_security_level_t actual_level = packet[4]; 922 gap_security_level_t required_level = channel->required_security_level; 923 924 switch (channel->state){ 925 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 926 if (actual_level >= required_level){ 927 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 928 l2cap_emit_connection_request(channel); 929 } else { 930 channel->reason = 0x03; // security block 931 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 932 } 933 break; 934 935 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 936 if (actual_level >= required_level){ 937 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 938 } else { 939 // disconnnect, authentication not good enough 940 hci_disconnect_security_block(handle); 941 } 942 break; 943 944 default: 945 break; 946 } 947 } 948 break; 949 950 default: 951 break; 952 } 953 954 // pass on: main packet handler, att and sm packet handlers 955 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 956 if (attribute_protocol_packet_handler){ 957 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 958 } 959 if (security_protocol_packet_handler) { 960 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 961 } 962 963 l2cap_run(); 964 } 965 966 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 967 channel->remote_sig_id = identifier; 968 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 969 l2cap_run(); 970 } 971 972 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 973 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 974 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 975 signaling_responses[signaling_responses_pending].handle = handle; 976 signaling_responses[signaling_responses_pending].code = code; 977 signaling_responses[signaling_responses_pending].sig_id = sig_id; 978 signaling_responses[signaling_responses_pending].data = data; 979 signaling_responses_pending++; 980 l2cap_run(); 981 } 982 } 983 984 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 985 986 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x\n", handle, psm, source_cid); 987 l2cap_service_t *service = l2cap_get_service(psm); 988 if (!service) { 989 // 0x0002 PSM not supported 990 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 991 return; 992 } 993 994 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 995 if (!hci_connection) { 996 // 997 log_error("no hci_connection for handle %u\n", handle); 998 return; 999 } 1000 1001 // reject connection (0x03 security block) and disconnect if both have SSP, connection is not encrypted and PSM != SDP 1002 if ( hci_ssp_supported_on_both_sides(handle) 1003 && gap_security_level(handle) == LEVEL_0 1004 && !l2cap_security_level_0_allowed_for_PSM(psm)){ 1005 1006 // 0x0003 Security Block 1007 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0003); 1008 return; 1009 } 1010 1011 1012 // alloc structure 1013 // log_info("l2cap_handle_connection_request register channel\n"); 1014 l2cap_channel_t * channel = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 1015 if (!channel){ 1016 // 0x0004 No resources available 1017 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 1018 return; 1019 } 1020 1021 // fill in 1022 BD_ADDR_COPY(channel->address, hci_connection->address); 1023 channel->psm = psm; 1024 channel->handle = handle; 1025 channel->connection = service->connection; 1026 channel->packet_handler = service->packet_handler; 1027 channel->local_cid = l2cap_next_local_cid(); 1028 channel->remote_cid = source_cid; 1029 channel->local_mtu = service->mtu; 1030 channel->remote_mtu = L2CAP_DEFAULT_MTU; 1031 channel->packets_granted = 0; 1032 channel->remote_sig_id = sig_id; 1033 channel->required_security_level = service->required_security_level; 1034 1035 // limit local mtu to max acl packet length 1036 if (channel->local_mtu > l2cap_max_mtu()) { 1037 channel->local_mtu = l2cap_max_mtu(); 1038 } 1039 1040 // set initial state 1041 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1042 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 1043 1044 // add to connections list 1045 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 1046 1047 // assert security requirements 1048 gap_request_security_level(handle, channel->required_security_level); 1049 } 1050 1051 void l2cap_accept_connection_internal(uint16_t local_cid){ 1052 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1053 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1054 if (!channel) { 1055 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 1056 return; 1057 } 1058 1059 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1060 1061 // process 1062 l2cap_run(); 1063 } 1064 1065 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 1066 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); 1067 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1068 if (!channel) { 1069 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 1070 return; 1071 } 1072 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1073 channel->reason = reason; 1074 l2cap_run(); 1075 } 1076 1077 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1078 1079 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1080 1081 uint16_t flags = READ_BT_16(command, 6); 1082 if (flags & 1) { 1083 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1084 } 1085 1086 // accept the other's configuration options 1087 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1088 uint16_t pos = 8; 1089 while (pos < end_pos){ 1090 uint8_t option_hint = command[pos] >> 7; 1091 uint8_t option_type = command[pos] & 0x7f; 1092 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1093 pos++; 1094 uint8_t length = command[pos++]; 1095 // MTU { type(8): 1, len(8):2, MTU(16) } 1096 if (option_type == 1 && length == 2){ 1097 channel->remote_mtu = READ_BT_16(command, pos); 1098 // log_info("l2cap cid 0x%02x, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 1099 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1100 } 1101 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1102 if (option_type == 2 && length == 2){ 1103 channel->flush_timeout = READ_BT_16(command, pos); 1104 } 1105 // check for unknown options 1106 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1107 log_info("l2cap cid %u, unknown options", channel->local_cid); 1108 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1109 } 1110 pos += length; 1111 } 1112 } 1113 1114 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1115 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 1116 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1117 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1118 return 1; 1119 } 1120 1121 1122 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1123 1124 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1125 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1126 uint16_t result = 0; 1127 1128 log_info("L2CAP signaling handler code %u, state %u\n", code, channel->state); 1129 1130 // handle DISCONNECT REQUESTS seperately 1131 if (code == DISCONNECTION_REQUEST){ 1132 switch (channel->state){ 1133 case L2CAP_STATE_CONFIG: 1134 case L2CAP_STATE_OPEN: 1135 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1136 case L2CAP_STATE_WAIT_DISCONNECT: 1137 l2cap_handle_disconnect_request(channel, identifier); 1138 break; 1139 1140 default: 1141 // ignore in other states 1142 break; 1143 } 1144 return; 1145 } 1146 1147 // @STATEMACHINE(l2cap) 1148 switch (channel->state) { 1149 1150 case L2CAP_STATE_WAIT_CONNECT_RSP: 1151 switch (code){ 1152 case CONNECTION_RESPONSE: 1153 l2cap_stop_rtx(channel); 1154 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1155 switch (result) { 1156 case 0: 1157 // successful connection 1158 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1159 channel->state = L2CAP_STATE_CONFIG; 1160 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1161 break; 1162 case 1: 1163 // connection pending. get some coffee, but start the ERTX 1164 l2cap_start_ertx(channel); 1165 break; 1166 default: 1167 // channel closed 1168 channel->state = L2CAP_STATE_CLOSED; 1169 // map l2cap connection response result to BTstack status enumeration 1170 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1171 1172 // drop link key if security block 1173 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1174 hci_drop_link_key_for_bd_addr(&channel->address); 1175 } 1176 1177 // discard channel 1178 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1179 btstack_memory_l2cap_channel_free(channel); 1180 break; 1181 } 1182 break; 1183 1184 default: 1185 //@TODO: implement other signaling packets 1186 break; 1187 } 1188 break; 1189 1190 case L2CAP_STATE_CONFIG: 1191 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1192 switch (code) { 1193 case CONFIGURE_REQUEST: 1194 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1195 l2cap_signaling_handle_configure_request(channel, command); 1196 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1197 // only done if continuation not set 1198 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1199 } 1200 break; 1201 case CONFIGURE_RESPONSE: 1202 l2cap_stop_rtx(channel); 1203 switch (result){ 1204 case 0: // success 1205 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1206 break; 1207 case 4: // pending 1208 l2cap_start_ertx(channel); 1209 break; 1210 default: 1211 // retry on negative result 1212 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1213 break; 1214 } 1215 break; 1216 default: 1217 break; 1218 } 1219 if (l2cap_channel_ready_for_open(channel)){ 1220 // for open: 1221 channel->state = L2CAP_STATE_OPEN; 1222 l2cap_emit_channel_opened(channel, 0); 1223 l2cap_emit_credits(channel, 1); 1224 } 1225 break; 1226 1227 case L2CAP_STATE_WAIT_DISCONNECT: 1228 switch (code) { 1229 case DISCONNECTION_RESPONSE: 1230 l2cap_finialize_channel_close(channel); 1231 break; 1232 default: 1233 //@TODO: implement other signaling packets 1234 break; 1235 } 1236 break; 1237 1238 case L2CAP_STATE_CLOSED: 1239 // @TODO handle incoming requests 1240 break; 1241 1242 case L2CAP_STATE_OPEN: 1243 //@TODO: implement other signaling packets, e.g. re-configure 1244 break; 1245 default: 1246 break; 1247 } 1248 // log_info("new state %u\n", channel->state); 1249 } 1250 1251 1252 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1253 1254 // get code, signalind identifier and command len 1255 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1256 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1257 1258 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1259 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1260 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1261 return; 1262 } 1263 1264 // general commands without an assigned channel 1265 switch(code) { 1266 1267 case CONNECTION_REQUEST: { 1268 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1269 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1270 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1271 return; 1272 } 1273 1274 case ECHO_REQUEST: 1275 l2cap_register_signaling_response(handle, code, sig_id, 0); 1276 return; 1277 1278 case INFORMATION_REQUEST: { 1279 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1280 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1281 return; 1282 } 1283 1284 default: 1285 break; 1286 } 1287 1288 1289 // Get potential destination CID 1290 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1291 1292 // Find channel for this sig_id and connection handle 1293 linked_list_iterator_t it; 1294 linked_list_iterator_init(&it, &l2cap_channels); 1295 while (linked_list_iterator_has_next(&it)){ 1296 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 1297 if (channel->handle != handle) continue; 1298 if (code & 1) { 1299 // match odd commands (responses) by previous signaling identifier 1300 if (channel->local_sig_id == sig_id) { 1301 l2cap_signaling_handler_channel(channel, command); 1302 break; 1303 } 1304 } else { 1305 // match even commands (requests) by local channel id 1306 if (channel->local_cid == dest_cid) { 1307 l2cap_signaling_handler_channel(channel, command); 1308 break; 1309 } 1310 } 1311 } 1312 } 1313 1314 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 1315 1316 // Get Channel ID 1317 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1318 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1319 1320 switch (channel_id) { 1321 1322 case L2CAP_CID_SIGNALING: { 1323 1324 uint16_t command_offset = 8; 1325 while (command_offset < size) { 1326 1327 // handle signaling commands 1328 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1329 1330 // increment command_offset 1331 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1332 } 1333 break; 1334 } 1335 1336 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1337 if (attribute_protocol_packet_handler) { 1338 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1339 } 1340 break; 1341 1342 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1343 if (security_protocol_packet_handler) { 1344 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1345 } 1346 break; 1347 1348 case L2CAP_CID_SIGNALING_LE: { 1349 switch (packet[8]){ 1350 case CONNECTION_PARAMETER_UPDATE_RESPONSE: { 1351 uint16_t result = READ_BT_16(packet, 12); 1352 l2cap_emit_connection_parameter_update_response(handle, result); 1353 break; 1354 } 1355 case CONNECTION_PARAMETER_UPDATE_REQUEST: { 1356 uint8_t event[10]; 1357 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 1358 event[1] = 8; 1359 memcpy(&event[2], &packet[12], 8); 1360 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1361 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, event, sizeof(event)); 1362 break; 1363 } 1364 default: { 1365 uint8_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1366 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1367 break; 1368 } 1369 } 1370 break; 1371 } 1372 1373 default: { 1374 // Find channel for this channel_id and connection handle 1375 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1376 if (channel) { 1377 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1378 } 1379 break; 1380 } 1381 } 1382 } 1383 1384 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1385 switch (packet_type) { 1386 case HCI_EVENT_PACKET: 1387 l2cap_event_handler(packet, size); 1388 break; 1389 case HCI_ACL_DATA_PACKET: 1390 l2cap_acl_handler(packet, size); 1391 break; 1392 default: 1393 break; 1394 } 1395 l2cap_run(); 1396 } 1397 1398 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1399 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1400 channel->state = L2CAP_STATE_CLOSED; 1401 l2cap_emit_channel_closed(channel); 1402 // discard channel 1403 l2cap_stop_rtx(channel); 1404 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1405 btstack_memory_l2cap_channel_free(channel); 1406 } 1407 1408 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1409 linked_list_iterator_t it; 1410 linked_list_iterator_init(&it, &l2cap_services); 1411 while (linked_list_iterator_has_next(&it)){ 1412 l2cap_service_t * service = (l2cap_service_t *) linked_list_iterator_next(&it); 1413 if ( service->psm == psm){ 1414 return service; 1415 }; 1416 } 1417 return NULL; 1418 } 1419 1420 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){ 1421 1422 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1423 1424 // check for alread registered psm 1425 // TODO: emit error event 1426 l2cap_service_t *service = l2cap_get_service(psm); 1427 if (service) { 1428 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 1429 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1430 return; 1431 } 1432 1433 // alloc structure 1434 // TODO: emit error event 1435 service = (l2cap_service_t *) btstack_memory_l2cap_service_get(); 1436 if (!service) { 1437 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 1438 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1439 return; 1440 } 1441 1442 // fill in 1443 service->psm = psm; 1444 service->mtu = mtu; 1445 service->connection = connection; 1446 service->packet_handler = packet_handler; 1447 service->required_security_level = security_level; 1448 1449 // add to services list 1450 linked_list_add(&l2cap_services, (linked_item_t *) service); 1451 1452 // enable page scan 1453 hci_connectable_control(1); 1454 1455 // done 1456 l2cap_emit_service_registered(connection, 0, psm); 1457 } 1458 1459 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1460 1461 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1462 1463 l2cap_service_t *service = l2cap_get_service(psm); 1464 if (!service) return; 1465 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1466 btstack_memory_l2cap_service_free(service); 1467 1468 // disable page scan when no services registered 1469 if (!linked_list_empty(&l2cap_services)) return; 1470 hci_connectable_control(0); 1471 } 1472 1473 // 1474 void l2cap_close_connection(void *connection){ 1475 1476 linked_list_iterator_t it; 1477 1478 // close open channels 1479 linked_list_iterator_init(&it, &l2cap_channels); 1480 while (linked_list_iterator_has_next(&it)){ 1481 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 1482 if (channel->connection != connection) continue; 1483 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1484 channel->connection = NULL; 1485 } 1486 1487 // unregister services 1488 linked_list_iterator_init(&it, &l2cap_services); 1489 while (linked_list_iterator_has_next(&it)){ 1490 l2cap_service_t * service = (l2cap_service_t *) linked_list_iterator_next(&it); 1491 if (service->connection != connection) continue; 1492 linked_list_iterator_remove(&it); 1493 btstack_memory_l2cap_service_free(service); 1494 } 1495 1496 // process 1497 l2cap_run(); 1498 } 1499 1500 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1501 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1502 switch(channel_id){ 1503 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1504 attribute_protocol_packet_handler = packet_handler; 1505 break; 1506 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1507 security_protocol_packet_handler = packet_handler; 1508 break; 1509 } 1510 } 1511 1512 #ifdef HAVE_BLE 1513 // Request LE connection parameter update 1514 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){ 1515 if (!hci_can_send_acl_packet_now(handle)){ 1516 log_info("l2cap_send_signaling_packet, cannot send\n"); 1517 return BTSTACK_ACL_BUFFERS_FULL; 1518 } 1519 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 1520 hci_reserve_packet_buffer(); 1521 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1522 uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); 1523 return hci_send_acl_packet_buffer(len); 1524 } 1525 #endif 1526 1527