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_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET); 248 } 249 250 int l2cap_can_send_connectionless_packet_now(void){ 251 return hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET); 252 } 253 254 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 255 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 256 if (channel) { 257 return channel->remote_mtu; 258 } 259 return 0; 260 } 261 262 static l2cap_channel_t * l2cap_channel_for_rtx_timer(timer_source_t * ts){ 263 linked_list_iterator_t it; 264 linked_list_iterator_init(&it, &l2cap_channels); 265 while (linked_list_iterator_has_next(&it)){ 266 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 267 if ( &channel->rtx == ts) { 268 return channel; 269 } 270 } 271 return NULL; 272 } 273 274 static void l2cap_rtx_timeout(timer_source_t * ts){ 275 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 276 if (!ts) return; 277 278 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 279 280 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 281 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 282 // notify client 283 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 284 285 // discard channel 286 // no need to stop timer here, it is removed from list during timer callback 287 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 288 btstack_memory_l2cap_channel_free(channel); 289 } 290 291 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 292 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 293 run_loop_remove_timer(&channel->rtx); 294 } 295 296 static void l2cap_start_rtx(l2cap_channel_t * channel){ 297 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 298 l2cap_stop_rtx(channel); 299 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 300 run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 301 run_loop_add_timer(&channel->rtx); 302 } 303 304 static void l2cap_start_ertx(l2cap_channel_t * channel){ 305 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 306 l2cap_stop_rtx(channel); 307 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 308 run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 309 run_loop_add_timer(&channel->rtx); 310 } 311 312 void l2cap_require_security_level_2_for_outgoing_sdp(){ 313 require_security_level2_for_outgoing_sdp = 1; 314 } 315 316 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 317 return (psm == PSM_SDP) && (!require_security_level2_for_outgoing_sdp); 318 } 319 320 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 321 322 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 323 log_info("l2cap_send_signaling_packet, cannot send\n"); 324 return BTSTACK_ACL_BUFFERS_FULL; 325 } 326 327 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 328 hci_reserve_packet_buffer(); 329 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 330 va_list argptr; 331 va_start(argptr, identifier); 332 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 333 va_end(argptr); 334 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 335 return hci_send_acl_packet_buffer(len); 336 } 337 338 #ifdef HAVE_BLE 339 int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 340 341 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 342 log_info("l2cap_send_signaling_packet, cannot send\n"); 343 return BTSTACK_ACL_BUFFERS_FULL; 344 } 345 346 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 347 hci_reserve_packet_buffer(); 348 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 349 va_list argptr; 350 va_start(argptr, identifier); 351 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 352 va_end(argptr); 353 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 354 return hci_send_acl_packet_buffer(len); 355 } 356 #endif 357 358 uint8_t *l2cap_get_outgoing_buffer(void){ 359 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 360 } 361 362 int l2cap_reserve_packet_buffer(void){ 363 return hci_reserve_packet_buffer(); 364 } 365 366 void l2cap_release_packet_buffer(void){ 367 hci_release_packet_buffer(); 368 } 369 370 371 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 372 373 if (!hci_is_packet_buffer_reserved()){ 374 log_error("l2cap_send_prepared called without reserving packet first"); 375 return BTSTACK_ACL_BUFFERS_FULL; 376 } 377 378 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 379 log_info("l2cap_send_prepared cid 0x%02x, cannot send\n", local_cid); 380 return BTSTACK_ACL_BUFFERS_FULL; 381 } 382 383 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 384 if (!channel) { 385 log_error("l2cap_send_prepared no channel for cid 0x%02x\n", local_cid); 386 return -1; // TODO: define error 387 } 388 389 if (channel->packets_granted == 0){ 390 log_error("l2cap_send_prepared cid 0x%02x, no credits!\n", local_cid); 391 return -1; // TODO: define error 392 } 393 394 --channel->packets_granted; 395 396 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used, credits left %u;\n", 397 local_cid, channel->handle, channel->packets_granted); 398 399 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 400 401 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 402 403 // 0 - Connection handle : PB=pb : BC=00 404 bt_store_16(acl_buffer, 0, channel->handle | (pb << 12) | (0 << 14)); 405 // 2 - ACL length 406 bt_store_16(acl_buffer, 2, len + 4); 407 // 4 - L2CAP packet length 408 bt_store_16(acl_buffer, 4, len + 0); 409 // 6 - L2CAP channel DEST 410 bt_store_16(acl_buffer, 6, channel->remote_cid); 411 // send 412 int err = hci_send_acl_packet_buffer(len+8); 413 414 l2cap_hand_out_credits(); 415 416 return err; 417 } 418 419 int l2cap_send_prepared_connectionless(uint16_t handle, uint16_t cid, uint16_t len){ 420 421 if (!hci_is_packet_buffer_reserved()){ 422 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 423 return BTSTACK_ACL_BUFFERS_FULL; 424 } 425 426 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 427 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send\n", handle, cid); 428 return BTSTACK_ACL_BUFFERS_FULL; 429 } 430 431 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x\n", handle, cid); 432 433 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 434 435 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 436 437 // 0 - Connection handle : PB=pb : BC=00 438 bt_store_16(acl_buffer, 0, handle | (pb << 12) | (0 << 14)); 439 // 2 - ACL length 440 bt_store_16(acl_buffer, 2, len + 4); 441 // 4 - L2CAP packet length 442 bt_store_16(acl_buffer, 4, len + 0); 443 // 6 - L2CAP channel DEST 444 bt_store_16(acl_buffer, 6, cid); 445 // send 446 int err = hci_send_acl_packet_buffer(len+8); 447 448 l2cap_hand_out_credits(); 449 450 return err; 451 } 452 453 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 454 455 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 456 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", local_cid); 457 return BTSTACK_ACL_BUFFERS_FULL; 458 } 459 460 hci_reserve_packet_buffer(); 461 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 462 463 memcpy(&acl_buffer[8], data, len); 464 465 return l2cap_send_prepared(local_cid, len); 466 } 467 468 int l2cap_send_connectionless(uint16_t handle, uint16_t cid, uint8_t *data, uint16_t len){ 469 470 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 471 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", cid); 472 return BTSTACK_ACL_BUFFERS_FULL; 473 } 474 475 hci_reserve_packet_buffer(); 476 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 477 478 memcpy(&acl_buffer[8], data, len); 479 480 return l2cap_send_prepared_connectionless(handle, cid, len); 481 } 482 483 int l2cap_send_echo_request(uint16_t handle, uint8_t *data, uint16_t len){ 484 return l2cap_send_signaling_packet(handle, ECHO_REQUEST, 0x77, len, data); 485 } 486 487 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 488 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 489 } 490 491 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 492 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 493 } 494 495 496 497 // MARK: L2CAP_RUN 498 // process outstanding signaling tasks 499 void l2cap_run(void){ 500 501 // check pending signaling responses 502 while (signaling_responses_pending){ 503 504 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)) break; 505 506 hci_con_handle_t handle = signaling_responses[0].handle; 507 uint8_t sig_id = signaling_responses[0].sig_id; 508 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 509 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 510 511 switch (signaling_responses[0].code){ 512 case CONNECTION_REQUEST: 513 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 514 // also disconnect if result is 0x0003 - security blocked 515 hci_disconnect_security_block(handle); 516 break; 517 case ECHO_REQUEST: 518 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 519 break; 520 case INFORMATION_REQUEST: 521 switch (infoType){ 522 case 1: { // Connectionless MTU 523 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 524 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 525 break; 526 } 527 case 2: { // Extended Features Supported 528 // extended features request supported, only supporing fixed channel map 529 uint32_t features = 0x80; 530 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 531 break; 532 } 533 case 3: { // Fixed Channels Supported 534 uint8_t map[8]; 535 memset(map, 0, 8); 536 map[0] = 0x01; // L2CAP Signaling Channel 537 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 538 break; 539 } 540 default: 541 // all other types are not supported 542 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 543 break; 544 } 545 break; 546 case COMMAND_REJECT: 547 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 548 #ifdef HAVE_BLE 549 case COMMAND_REJECT_LE: 550 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 551 break; 552 #endif 553 default: 554 // should not happen 555 break; 556 } 557 558 // remove first item 559 signaling_responses_pending--; 560 int i; 561 for (i=0; i < signaling_responses_pending; i++){ 562 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 563 } 564 } 565 566 uint8_t config_options[4]; 567 linked_list_iterator_t it; 568 linked_list_iterator_init(&it, &l2cap_channels); 569 while (linked_list_iterator_has_next(&it)){ 570 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 571 572 if (!hci_can_send_command_packet_now()) break; 573 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)) break; 574 575 // log_info("l2cap_run: state %u, var 0x%02x\n", channel->state, channel->state_var); 576 577 switch (channel->state){ 578 579 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 580 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 581 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 582 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 583 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 584 } 585 break; 586 587 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 588 // send connection request - set state first 589 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 590 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 591 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 592 break; 593 594 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 595 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 596 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 597 l2cap_stop_rtx(channel); 598 linked_list_iterator_remove(&it); 599 btstack_memory_l2cap_channel_free(channel); 600 break; 601 602 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 603 channel->state = L2CAP_STATE_CONFIG; 604 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 605 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 606 break; 607 608 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 609 // success, start l2cap handshake 610 channel->local_sig_id = l2cap_next_sig_id(); 611 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 612 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 613 l2cap_start_rtx(channel); 614 break; 615 616 case L2CAP_STATE_CONFIG: 617 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 618 uint16_t flags = 0; 619 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 620 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 621 flags = 1; 622 } else { 623 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 624 } 625 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 626 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 627 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 628 config_options[0] = 1; // MTU 629 config_options[1] = 2; // len param 630 bt_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 631 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 632 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 633 } else { 634 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 635 } 636 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 637 } 638 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 639 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 640 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 641 channel->local_sig_id = l2cap_next_sig_id(); 642 config_options[0] = 1; // MTU 643 config_options[1] = 2; // len param 644 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 645 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 646 l2cap_start_rtx(channel); 647 } 648 if (l2cap_channel_ready_for_open(channel)){ 649 channel->state = L2CAP_STATE_OPEN; 650 l2cap_emit_channel_opened(channel, 0); // success 651 l2cap_emit_credits(channel, 1); 652 } 653 break; 654 655 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 656 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 657 // 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 :) 658 l2cap_finialize_channel_close(channel); // -- remove from list 659 break; 660 661 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 662 channel->local_sig_id = l2cap_next_sig_id(); 663 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 664 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 665 break; 666 default: 667 break; 668 } 669 } 670 } 671 672 uint16_t l2cap_max_mtu(void){ 673 return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE; 674 } 675 676 static void l2cap_handle_connection_complete(uint16_t handle, l2cap_channel_t * channel){ 677 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 678 log_info("l2cap_handle_connection_complete expected state"); 679 // success, start l2cap handshake 680 channel->handle = handle; 681 channel->local_cid = l2cap_next_local_cid(); 682 // check remote SSP feature first 683 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 684 } 685 } 686 687 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 688 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 689 690 // we have been waiting for remote supported features, if both support SSP, 691 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)); 692 if (hci_ssp_supported_on_both_sides(channel->handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 693 // request security level 2 694 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 695 gap_request_security_level(channel->handle, LEVEL_2); 696 return; 697 } 698 // fine, go ahead 699 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 700 } 701 702 // open outgoing L2CAP channel 703 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 704 bd_addr_t address, uint16_t psm, uint16_t mtu){ 705 706 log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 707 708 // alloc structure 709 l2cap_channel_t * chan = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 710 if (!chan) { 711 // emit error event 712 l2cap_channel_t dummy_channel; 713 BD_ADDR_COPY(dummy_channel.address, address); 714 dummy_channel.psm = psm; 715 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 716 return; 717 } 718 // limit local mtu to max acl packet length 719 if (mtu > l2cap_max_mtu()) { 720 mtu = l2cap_max_mtu(); 721 } 722 723 // fill in 724 BD_ADDR_COPY(chan->address, address); 725 chan->psm = psm; 726 chan->handle = 0; 727 chan->connection = connection; 728 chan->packet_handler = packet_handler; 729 chan->remote_mtu = L2CAP_MINIMAL_MTU; 730 chan->local_mtu = mtu; 731 chan->packets_granted = 0; 732 733 // set initial state 734 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 735 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 736 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 737 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 738 chan->required_security_level = LEVEL_0; 739 740 // add to connections list 741 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 742 743 // check if hci connection is already usable 744 hci_connection_t * conn = hci_connection_for_bd_addr_and_type((bd_addr_t*)address, BD_ADDR_TYPE_CLASSIC); 745 if (conn){ 746 log_info("l2cap_create_channel_internal, hci connection already exists"); 747 l2cap_handle_connection_complete(conn->con_handle, chan); 748 // check ir remote supported fearures are already received 749 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 750 l2cap_handle_remote_supported_features_received(chan); 751 } 752 } 753 754 l2cap_run(); 755 } 756 757 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 758 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 759 // find channel for local_cid 760 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 761 if (channel) { 762 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 763 } 764 // process 765 l2cap_run(); 766 } 767 768 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 769 linked_list_iterator_t it; 770 linked_list_iterator_init(&it, &l2cap_channels); 771 while (linked_list_iterator_has_next(&it)){ 772 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 773 if ( BD_ADDR_CMP( channel->address, address) != 0) continue; 774 // channel for this address found 775 switch (channel->state){ 776 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 777 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 778 // failure, forward error code 779 l2cap_emit_channel_opened(channel, status); 780 // discard channel 781 l2cap_stop_rtx(channel); 782 linked_list_iterator_remove(&it); 783 btstack_memory_l2cap_channel_free(channel); 784 break; 785 default: 786 break; 787 } 788 } 789 } 790 791 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 792 linked_list_iterator_t it; 793 linked_list_iterator_init(&it, &l2cap_channels); 794 while (linked_list_iterator_has_next(&it)){ 795 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 796 if ( ! BD_ADDR_CMP( channel->address, address) ){ 797 l2cap_handle_connection_complete(handle, channel); 798 } 799 } 800 // process 801 l2cap_run(); 802 } 803 804 void l2cap_event_handler(uint8_t *packet, uint16_t size){ 805 806 bd_addr_t address; 807 hci_con_handle_t handle; 808 linked_list_iterator_t it; 809 int hci_con_used; 810 811 switch(packet[0]){ 812 813 // handle connection complete events 814 case HCI_EVENT_CONNECTION_COMPLETE: 815 bt_flip_addr(address, &packet[5]); 816 if (packet[2] == 0){ 817 handle = READ_BT_16(packet, 3); 818 l2cap_handle_connection_success_for_addr(address, handle); 819 } else { 820 l2cap_handle_connection_failed_for_addr(address, packet[2]); 821 } 822 break; 823 824 // handle successful create connection cancel command 825 case HCI_EVENT_COMMAND_COMPLETE: 826 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 827 if (packet[5] == 0){ 828 bt_flip_addr(address, &packet[6]); 829 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 830 l2cap_handle_connection_failed_for_addr(address, 0x16); 831 } 832 } 833 l2cap_run(); // try sending signaling packets first 834 break; 835 836 case HCI_EVENT_COMMAND_STATUS: 837 l2cap_run(); // try sending signaling packets first 838 break; 839 840 // handle disconnection complete events 841 case HCI_EVENT_DISCONNECTION_COMPLETE: 842 // send l2cap disconnect events for all channels on this handle and free them 843 handle = READ_BT_16(packet, 3); 844 linked_list_iterator_init(&it, &l2cap_channels); 845 while (linked_list_iterator_has_next(&it)){ 846 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 847 if (channel->handle != handle) continue; 848 l2cap_emit_channel_closed(channel); 849 l2cap_stop_rtx(channel); 850 linked_list_iterator_remove(&it); 851 btstack_memory_l2cap_channel_free(channel); 852 } 853 break; 854 855 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 856 l2cap_run(); // try sending signaling packets first 857 l2cap_hand_out_credits(); 858 break; 859 860 // HCI Connection Timeouts 861 case L2CAP_EVENT_TIMEOUT_CHECK: 862 handle = READ_BT_16(packet, 2); 863 if (hci_authentication_active_for_handle(handle)) break; 864 hci_con_used = 0; 865 linked_list_iterator_init(&it, &l2cap_channels); 866 while (linked_list_iterator_has_next(&it)){ 867 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 868 if (channel->handle != handle) continue; 869 hci_con_used = 1; 870 break; 871 } 872 if (hci_con_used) break; 873 if (!hci_can_send_command_packet_now()) break; 874 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 875 break; 876 877 case DAEMON_EVENT_HCI_PACKET_SENT: 878 linked_list_iterator_init(&it, &l2cap_channels); 879 while (linked_list_iterator_has_next(&it)){ 880 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 881 if (!channel->packet_handler) continue; 882 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 883 } 884 if (attribute_protocol_packet_handler) { 885 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 886 } 887 if (security_protocol_packet_handler) { 888 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 889 } 890 break; 891 892 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 893 handle = READ_BT_16(packet, 3); 894 linked_list_iterator_init(&it, &l2cap_channels); 895 while (linked_list_iterator_has_next(&it)){ 896 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 897 if (channel->handle != handle) continue; 898 l2cap_handle_remote_supported_features_received(channel); 899 break; 900 } 901 break; 902 903 case GAP_SECURITY_LEVEL: 904 handle = READ_BT_16(packet, 2); 905 log_info("l2cap - security level update"); 906 linked_list_iterator_init(&it, &l2cap_channels); 907 while (linked_list_iterator_has_next(&it)){ 908 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 909 if (channel->handle != handle) continue; 910 911 log_info("l2cap - state %u", channel->state); 912 913 gap_security_level_t actual_level = packet[4]; 914 gap_security_level_t required_level = channel->required_security_level; 915 916 switch (channel->state){ 917 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 918 if (actual_level >= required_level){ 919 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 920 l2cap_emit_connection_request(channel); 921 } else { 922 channel->reason = 0x03; // security block 923 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 924 } 925 break; 926 927 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 928 if (actual_level >= required_level){ 929 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 930 } else { 931 // disconnnect, authentication not good enough 932 hci_disconnect_security_block(handle); 933 } 934 break; 935 936 default: 937 break; 938 } 939 } 940 break; 941 942 default: 943 break; 944 } 945 946 // pass on: main packet handler, att and sm packet handlers 947 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 948 if (attribute_protocol_packet_handler){ 949 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 950 } 951 if (security_protocol_packet_handler) { 952 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 953 } 954 955 l2cap_run(); 956 } 957 958 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 959 channel->remote_sig_id = identifier; 960 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 961 l2cap_run(); 962 } 963 964 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 965 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 966 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 967 signaling_responses[signaling_responses_pending].handle = handle; 968 signaling_responses[signaling_responses_pending].code = code; 969 signaling_responses[signaling_responses_pending].sig_id = sig_id; 970 signaling_responses[signaling_responses_pending].data = data; 971 signaling_responses_pending++; 972 l2cap_run(); 973 } 974 } 975 976 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 977 978 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x\n", handle, psm, source_cid); 979 l2cap_service_t *service = l2cap_get_service(psm); 980 if (!service) { 981 // 0x0002 PSM not supported 982 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 983 return; 984 } 985 986 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 987 if (!hci_connection) { 988 // 989 log_error("no hci_connection for handle %u\n", handle); 990 return; 991 } 992 993 // reject connection (0x03 security block) and disconnect if both have SSP, connection is not encrypted and PSM != SDP 994 if ( hci_ssp_supported_on_both_sides(handle) 995 && gap_security_level(handle) == LEVEL_0 996 && !l2cap_security_level_0_allowed_for_PSM(psm)){ 997 998 // 0x0003 Security Block 999 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0003); 1000 return; 1001 } 1002 1003 1004 // alloc structure 1005 // log_info("l2cap_handle_connection_request register channel\n"); 1006 l2cap_channel_t * channel = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 1007 if (!channel){ 1008 // 0x0004 No resources available 1009 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 1010 return; 1011 } 1012 1013 // fill in 1014 BD_ADDR_COPY(channel->address, hci_connection->address); 1015 channel->psm = psm; 1016 channel->handle = handle; 1017 channel->connection = service->connection; 1018 channel->packet_handler = service->packet_handler; 1019 channel->local_cid = l2cap_next_local_cid(); 1020 channel->remote_cid = source_cid; 1021 channel->local_mtu = service->mtu; 1022 channel->remote_mtu = L2CAP_DEFAULT_MTU; 1023 channel->packets_granted = 0; 1024 channel->remote_sig_id = sig_id; 1025 channel->required_security_level = service->required_security_level; 1026 1027 // limit local mtu to max acl packet length 1028 if (channel->local_mtu > l2cap_max_mtu()) { 1029 channel->local_mtu = l2cap_max_mtu(); 1030 } 1031 1032 // set initial state 1033 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1034 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 1035 1036 // add to connections list 1037 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 1038 1039 // assert security requirements 1040 gap_request_security_level(handle, channel->required_security_level); 1041 } 1042 1043 void l2cap_accept_connection_internal(uint16_t local_cid){ 1044 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1045 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1046 if (!channel) { 1047 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 1048 return; 1049 } 1050 1051 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1052 1053 // process 1054 l2cap_run(); 1055 } 1056 1057 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 1058 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); 1059 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1060 if (!channel) { 1061 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 1062 return; 1063 } 1064 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1065 channel->reason = reason; 1066 l2cap_run(); 1067 } 1068 1069 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1070 1071 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1072 1073 uint16_t flags = READ_BT_16(command, 6); 1074 if (flags & 1) { 1075 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1076 } 1077 1078 // accept the other's configuration options 1079 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1080 uint16_t pos = 8; 1081 while (pos < end_pos){ 1082 uint8_t option_hint = command[pos] >> 7; 1083 uint8_t option_type = command[pos] & 0x7f; 1084 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1085 pos++; 1086 uint8_t length = command[pos++]; 1087 // MTU { type(8): 1, len(8):2, MTU(16) } 1088 if (option_type == 1 && length == 2){ 1089 channel->remote_mtu = READ_BT_16(command, pos); 1090 // log_info("l2cap cid 0x%02x, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 1091 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1092 } 1093 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1094 if (option_type == 2 && length == 2){ 1095 channel->flush_timeout = READ_BT_16(command, pos); 1096 } 1097 // check for unknown options 1098 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1099 log_info("l2cap cid %u, unknown options", channel->local_cid); 1100 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1101 } 1102 pos += length; 1103 } 1104 } 1105 1106 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1107 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 1108 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1109 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1110 return 1; 1111 } 1112 1113 1114 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1115 1116 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1117 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1118 uint16_t result = 0; 1119 1120 log_info("L2CAP signaling handler code %u, state %u\n", code, channel->state); 1121 1122 // handle DISCONNECT REQUESTS seperately 1123 if (code == DISCONNECTION_REQUEST){ 1124 switch (channel->state){ 1125 case L2CAP_STATE_CONFIG: 1126 case L2CAP_STATE_OPEN: 1127 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1128 case L2CAP_STATE_WAIT_DISCONNECT: 1129 l2cap_handle_disconnect_request(channel, identifier); 1130 break; 1131 1132 default: 1133 // ignore in other states 1134 break; 1135 } 1136 return; 1137 } 1138 1139 // @STATEMACHINE(l2cap) 1140 switch (channel->state) { 1141 1142 case L2CAP_STATE_WAIT_CONNECT_RSP: 1143 switch (code){ 1144 case CONNECTION_RESPONSE: 1145 l2cap_stop_rtx(channel); 1146 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1147 switch (result) { 1148 case 0: 1149 // successful connection 1150 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1151 channel->state = L2CAP_STATE_CONFIG; 1152 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1153 break; 1154 case 1: 1155 // connection pending. get some coffee, but start the ERTX 1156 l2cap_start_ertx(channel); 1157 break; 1158 default: 1159 // channel closed 1160 channel->state = L2CAP_STATE_CLOSED; 1161 // map l2cap connection response result to BTstack status enumeration 1162 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1163 1164 // drop link key if security block 1165 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1166 hci_drop_link_key_for_bd_addr(&channel->address); 1167 } 1168 1169 // discard channel 1170 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1171 btstack_memory_l2cap_channel_free(channel); 1172 break; 1173 } 1174 break; 1175 1176 default: 1177 //@TODO: implement other signaling packets 1178 break; 1179 } 1180 break; 1181 1182 case L2CAP_STATE_CONFIG: 1183 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1184 switch (code) { 1185 case CONFIGURE_REQUEST: 1186 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1187 l2cap_signaling_handle_configure_request(channel, command); 1188 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1189 // only done if continuation not set 1190 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1191 } 1192 break; 1193 case CONFIGURE_RESPONSE: 1194 l2cap_stop_rtx(channel); 1195 switch (result){ 1196 case 0: // success 1197 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1198 break; 1199 case 4: // pending 1200 l2cap_start_ertx(channel); 1201 break; 1202 default: 1203 // retry on negative result 1204 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1205 break; 1206 } 1207 break; 1208 default: 1209 break; 1210 } 1211 if (l2cap_channel_ready_for_open(channel)){ 1212 // for open: 1213 channel->state = L2CAP_STATE_OPEN; 1214 l2cap_emit_channel_opened(channel, 0); 1215 l2cap_emit_credits(channel, 1); 1216 } 1217 break; 1218 1219 case L2CAP_STATE_WAIT_DISCONNECT: 1220 switch (code) { 1221 case DISCONNECTION_RESPONSE: 1222 l2cap_finialize_channel_close(channel); 1223 break; 1224 default: 1225 //@TODO: implement other signaling packets 1226 break; 1227 } 1228 break; 1229 1230 case L2CAP_STATE_CLOSED: 1231 // @TODO handle incoming requests 1232 break; 1233 1234 case L2CAP_STATE_OPEN: 1235 //@TODO: implement other signaling packets, e.g. re-configure 1236 break; 1237 default: 1238 break; 1239 } 1240 // log_info("new state %u\n", channel->state); 1241 } 1242 1243 1244 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1245 1246 // get code, signalind identifier and command len 1247 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1248 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1249 1250 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1251 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1252 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1253 return; 1254 } 1255 1256 // general commands without an assigned channel 1257 switch(code) { 1258 1259 case CONNECTION_REQUEST: { 1260 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1261 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1262 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1263 return; 1264 } 1265 1266 case ECHO_REQUEST: 1267 l2cap_register_signaling_response(handle, code, sig_id, 0); 1268 return; 1269 1270 case INFORMATION_REQUEST: { 1271 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1272 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1273 return; 1274 } 1275 1276 default: 1277 break; 1278 } 1279 1280 1281 // Get potential destination CID 1282 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1283 1284 // Find channel for this sig_id and connection handle 1285 linked_list_iterator_t it; 1286 linked_list_iterator_init(&it, &l2cap_channels); 1287 while (linked_list_iterator_has_next(&it)){ 1288 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 1289 if (channel->handle != handle) continue; 1290 if (code & 1) { 1291 // match odd commands (responses) by previous signaling identifier 1292 if (channel->local_sig_id == sig_id) { 1293 l2cap_signaling_handler_channel(channel, command); 1294 break; 1295 } 1296 } else { 1297 // match even commands (requests) by local channel id 1298 if (channel->local_cid == dest_cid) { 1299 l2cap_signaling_handler_channel(channel, command); 1300 break; 1301 } 1302 } 1303 } 1304 } 1305 1306 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 1307 1308 // Get Channel ID 1309 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1310 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1311 1312 switch (channel_id) { 1313 1314 case L2CAP_CID_SIGNALING: { 1315 1316 uint16_t command_offset = 8; 1317 while (command_offset < size) { 1318 1319 // handle signaling commands 1320 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1321 1322 // increment command_offset 1323 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1324 } 1325 break; 1326 } 1327 1328 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1329 if (attribute_protocol_packet_handler) { 1330 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1331 } 1332 break; 1333 1334 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1335 if (security_protocol_packet_handler) { 1336 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1337 } 1338 break; 1339 1340 case L2CAP_CID_SIGNALING_LE: { 1341 switch (packet[8]){ 1342 case CONNECTION_PARAMETER_UPDATE_RESPONSE: { 1343 uint16_t result = READ_BT_16(packet, 12); 1344 l2cap_emit_connection_parameter_update_response(handle, result); 1345 break; 1346 } 1347 case CONNECTION_PARAMETER_UPDATE_REQUEST: { 1348 uint8_t event[10]; 1349 event[0] = L2CAP_EVENT_CONNECTION_PARAMETER_UPDATE_REQUEST; 1350 event[1] = 8; 1351 memcpy(&event[2], &packet[12], 8); 1352 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 1353 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, event, sizeof(event)); 1354 break; 1355 } 1356 default: { 1357 uint8_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1358 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1359 break; 1360 } 1361 } 1362 break; 1363 } 1364 1365 default: { 1366 // Find channel for this channel_id and connection handle 1367 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1368 if (channel) { 1369 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1370 } 1371 break; 1372 } 1373 } 1374 } 1375 1376 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1377 switch (packet_type) { 1378 case HCI_EVENT_PACKET: 1379 l2cap_event_handler(packet, size); 1380 break; 1381 case HCI_ACL_DATA_PACKET: 1382 l2cap_acl_handler(packet, size); 1383 break; 1384 default: 1385 break; 1386 } 1387 l2cap_run(); 1388 } 1389 1390 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1391 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1392 channel->state = L2CAP_STATE_CLOSED; 1393 l2cap_emit_channel_closed(channel); 1394 // discard channel 1395 l2cap_stop_rtx(channel); 1396 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1397 btstack_memory_l2cap_channel_free(channel); 1398 } 1399 1400 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1401 linked_list_iterator_t it; 1402 linked_list_iterator_init(&it, &l2cap_services); 1403 while (linked_list_iterator_has_next(&it)){ 1404 l2cap_service_t * service = (l2cap_service_t *) linked_list_iterator_next(&it); 1405 if ( service->psm == psm){ 1406 return service; 1407 }; 1408 } 1409 return NULL; 1410 } 1411 1412 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){ 1413 1414 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1415 1416 // check for alread registered psm 1417 // TODO: emit error event 1418 l2cap_service_t *service = l2cap_get_service(psm); 1419 if (service) { 1420 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 1421 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1422 return; 1423 } 1424 1425 // alloc structure 1426 // TODO: emit error event 1427 service = (l2cap_service_t *) btstack_memory_l2cap_service_get(); 1428 if (!service) { 1429 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 1430 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1431 return; 1432 } 1433 1434 // fill in 1435 service->psm = psm; 1436 service->mtu = mtu; 1437 service->connection = connection; 1438 service->packet_handler = packet_handler; 1439 service->required_security_level = security_level; 1440 1441 // add to services list 1442 linked_list_add(&l2cap_services, (linked_item_t *) service); 1443 1444 // enable page scan 1445 hci_connectable_control(1); 1446 1447 // done 1448 l2cap_emit_service_registered(connection, 0, psm); 1449 } 1450 1451 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1452 1453 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1454 1455 l2cap_service_t *service = l2cap_get_service(psm); 1456 if (!service) return; 1457 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1458 btstack_memory_l2cap_service_free(service); 1459 1460 // disable page scan when no services registered 1461 if (!linked_list_empty(&l2cap_services)) return; 1462 hci_connectable_control(0); 1463 } 1464 1465 // 1466 void l2cap_close_connection(void *connection){ 1467 1468 linked_list_iterator_t it; 1469 1470 // close open channels 1471 linked_list_iterator_init(&it, &l2cap_channels); 1472 while (linked_list_iterator_has_next(&it)){ 1473 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 1474 if (channel->connection != connection) continue; 1475 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1476 channel->connection = NULL; 1477 } 1478 1479 // unregister services 1480 linked_list_iterator_init(&it, &l2cap_services); 1481 while (linked_list_iterator_has_next(&it)){ 1482 l2cap_service_t * service = (l2cap_service_t *) linked_list_iterator_next(&it); 1483 if (service->connection != connection) continue; 1484 linked_list_iterator_remove(&it); 1485 btstack_memory_l2cap_service_free(service); 1486 } 1487 1488 // process 1489 l2cap_run(); 1490 } 1491 1492 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1493 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1494 switch(channel_id){ 1495 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1496 attribute_protocol_packet_handler = packet_handler; 1497 break; 1498 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1499 security_protocol_packet_handler = packet_handler; 1500 break; 1501 } 1502 } 1503 1504 #ifdef HAVE_BLE 1505 // Request LE connection parameter update 1506 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){ 1507 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 1508 log_info("l2cap_send_signaling_packet, cannot send\n"); 1509 return BTSTACK_ACL_BUFFERS_FULL; 1510 } 1511 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 1512 hci_reserve_packet_buffer(); 1513 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1514 uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); 1515 return hci_send_acl_packet_buffer(len); 1516 } 1517 #endif 1518 1519