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 static void l2cap_emit_service_registered(void *connection, uint8_t status, uint16_t psm){ 176 log_info("L2CAP_EVENT_SERVICE_REGISTERED status 0x%x psm 0x%x", status, psm); 177 uint8_t event[5]; 178 event[0] = L2CAP_EVENT_SERVICE_REGISTERED; 179 event[1] = sizeof(event) - 2; 180 event[2] = status; 181 bt_store_16(event, 3, psm); 182 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 183 (*packet_handler)(connection, HCI_EVENT_PACKET, 0, event, sizeof(event)); 184 } 185 186 void l2cap_emit_credits(l2cap_channel_t *channel, uint8_t credits) { 187 188 log_info("L2CAP_EVENT_CREDITS local_cid 0x%x credits %u", channel->local_cid, credits); 189 // track credits 190 channel->packets_granted += credits; 191 192 uint8_t event[5]; 193 event[0] = L2CAP_EVENT_CREDITS; 194 event[1] = sizeof(event) - 2; 195 bt_store_16(event, 2, channel->local_cid); 196 event[4] = credits; 197 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 198 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 199 } 200 201 void l2cap_block_new_credits(uint8_t blocked){ 202 new_credits_blocked = blocked; 203 } 204 205 void l2cap_hand_out_credits(void){ 206 207 if (new_credits_blocked) return; // we're told not to. used by daemon 208 209 linked_list_iterator_t it; 210 linked_list_iterator_init(&it, &l2cap_channels); 211 while (linked_list_iterator_has_next(&it)){ 212 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 213 if (!hci_number_free_acl_slots()) return; 214 if (channel->state != L2CAP_STATE_OPEN) continue; 215 if (hci_number_outgoing_packets(channel->handle) < NR_BUFFERED_ACL_PACKETS && channel->packets_granted == 0) { 216 l2cap_emit_credits(channel, 1); 217 } 218 } 219 } 220 221 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 222 linked_list_iterator_t it; 223 linked_list_iterator_init(&it, &l2cap_channels); 224 while (linked_list_iterator_has_next(&it)){ 225 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 226 if ( channel->local_cid == local_cid) { 227 return channel; 228 } 229 } 230 return NULL; 231 } 232 233 int l2cap_can_send_packet_now(uint16_t local_cid){ 234 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 235 if (!channel) return 0; 236 if (!channel->packets_granted) return 0; 237 return hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET); 238 } 239 240 int l2cap_can_send_connectionless_packet_now(void){ 241 return hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET); 242 } 243 244 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 245 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 246 if (channel) { 247 return channel->remote_mtu; 248 } 249 return 0; 250 } 251 252 static l2cap_channel_t * l2cap_channel_for_rtx_timer(timer_source_t * ts){ 253 linked_list_iterator_t it; 254 linked_list_iterator_init(&it, &l2cap_channels); 255 while (linked_list_iterator_has_next(&it)){ 256 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 257 if ( &channel->rtx == ts) { 258 return channel; 259 } 260 } 261 return NULL; 262 } 263 264 static void l2cap_rtx_timeout(timer_source_t * ts){ 265 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 266 if (!ts) return; 267 268 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 269 270 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 271 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 272 // notify client 273 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 274 275 // discard channel 276 // no need to stop timer here, it is removed from list during timer callback 277 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 278 btstack_memory_l2cap_channel_free(channel); 279 } 280 281 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 282 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 283 run_loop_remove_timer(&channel->rtx); 284 } 285 286 static void l2cap_start_rtx(l2cap_channel_t * channel){ 287 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 288 l2cap_stop_rtx(channel); 289 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 290 run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 291 run_loop_add_timer(&channel->rtx); 292 } 293 294 static void l2cap_start_ertx(l2cap_channel_t * channel){ 295 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 296 l2cap_stop_rtx(channel); 297 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 298 run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 299 run_loop_add_timer(&channel->rtx); 300 } 301 302 void l2cap_require_security_level_2_for_outgoing_sdp(){ 303 require_security_level2_for_outgoing_sdp = 1; 304 } 305 306 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 307 return (psm == PSM_SDP) && (!require_security_level2_for_outgoing_sdp); 308 } 309 310 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 311 312 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 313 log_info("l2cap_send_signaling_packet, cannot send\n"); 314 return BTSTACK_ACL_BUFFERS_FULL; 315 } 316 317 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 318 hci_reserve_packet_buffer(); 319 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 320 va_list argptr; 321 va_start(argptr, identifier); 322 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 323 va_end(argptr); 324 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 325 return hci_send_acl_packet_buffer(len); 326 } 327 328 #ifdef HAVE_BLE 329 int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 330 331 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 332 log_info("l2cap_send_signaling_packet, cannot send\n"); 333 return BTSTACK_ACL_BUFFERS_FULL; 334 } 335 336 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 337 hci_reserve_packet_buffer(); 338 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 339 va_list argptr; 340 va_start(argptr, identifier); 341 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 342 va_end(argptr); 343 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 344 return hci_send_acl_packet_buffer(len); 345 } 346 #endif 347 348 uint8_t *l2cap_get_outgoing_buffer(void){ 349 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 350 } 351 352 int l2cap_reserve_packet_buffer(void){ 353 return hci_reserve_packet_buffer(); 354 } 355 356 void l2cap_release_packet_buffer(void){ 357 hci_release_packet_buffer(); 358 } 359 360 361 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 362 363 if (!hci_is_packet_buffer_reserved()){ 364 log_error("l2cap_send_prepared called without reserving packet first"); 365 return BTSTACK_ACL_BUFFERS_FULL; 366 } 367 368 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 369 log_info("l2cap_send_prepared cid 0x%02x, cannot send\n", local_cid); 370 return BTSTACK_ACL_BUFFERS_FULL; 371 } 372 373 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 374 if (!channel) { 375 log_error("l2cap_send_prepared no channel for cid 0x%02x\n", local_cid); 376 return -1; // TODO: define error 377 } 378 379 if (channel->packets_granted == 0){ 380 log_error("l2cap_send_prepared cid 0x%02x, no credits!\n", local_cid); 381 return -1; // TODO: define error 382 } 383 384 --channel->packets_granted; 385 386 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used, credits left %u;\n", 387 local_cid, channel->handle, channel->packets_granted); 388 389 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 390 391 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 392 393 // 0 - Connection handle : PB=pb : BC=00 394 bt_store_16(acl_buffer, 0, channel->handle | (pb << 12) | (0 << 14)); 395 // 2 - ACL length 396 bt_store_16(acl_buffer, 2, len + 4); 397 // 4 - L2CAP packet length 398 bt_store_16(acl_buffer, 4, len + 0); 399 // 6 - L2CAP channel DEST 400 bt_store_16(acl_buffer, 6, channel->remote_cid); 401 // send 402 int err = hci_send_acl_packet_buffer(len+8); 403 404 l2cap_hand_out_credits(); 405 406 return err; 407 } 408 409 int l2cap_send_prepared_connectionless(uint16_t handle, uint16_t cid, uint16_t len){ 410 411 if (!hci_is_packet_buffer_reserved()){ 412 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 413 return BTSTACK_ACL_BUFFERS_FULL; 414 } 415 416 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 417 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send\n", handle, cid); 418 return BTSTACK_ACL_BUFFERS_FULL; 419 } 420 421 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x\n", handle, cid); 422 423 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 424 425 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 426 427 // 0 - Connection handle : PB=pb : BC=00 428 bt_store_16(acl_buffer, 0, handle | (pb << 12) | (0 << 14)); 429 // 2 - ACL length 430 bt_store_16(acl_buffer, 2, len + 4); 431 // 4 - L2CAP packet length 432 bt_store_16(acl_buffer, 4, len + 0); 433 // 6 - L2CAP channel DEST 434 bt_store_16(acl_buffer, 6, cid); 435 // send 436 int err = hci_send_acl_packet_buffer(len+8); 437 438 l2cap_hand_out_credits(); 439 440 return err; 441 } 442 443 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 444 445 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 446 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", local_cid); 447 return BTSTACK_ACL_BUFFERS_FULL; 448 } 449 450 hci_reserve_packet_buffer(); 451 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 452 453 memcpy(&acl_buffer[8], data, len); 454 455 return l2cap_send_prepared(local_cid, len); 456 } 457 458 int l2cap_send_connectionless(uint16_t handle, uint16_t cid, uint8_t *data, uint16_t len){ 459 460 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 461 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", cid); 462 return BTSTACK_ACL_BUFFERS_FULL; 463 } 464 465 hci_reserve_packet_buffer(); 466 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 467 468 memcpy(&acl_buffer[8], data, len); 469 470 return l2cap_send_prepared_connectionless(handle, cid, len); 471 } 472 473 int l2cap_send_echo_request(uint16_t handle, uint8_t *data, uint16_t len){ 474 return l2cap_send_signaling_packet(handle, ECHO_REQUEST, 0x77, len, data); 475 } 476 477 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 478 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 479 } 480 481 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 482 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 483 } 484 485 486 487 // MARK: L2CAP_RUN 488 // process outstanding signaling tasks 489 void l2cap_run(void){ 490 491 // check pending signaling responses 492 while (signaling_responses_pending){ 493 494 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)) break; 495 496 hci_con_handle_t handle = signaling_responses[0].handle; 497 uint8_t sig_id = signaling_responses[0].sig_id; 498 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 499 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 500 501 switch (signaling_responses[0].code){ 502 case CONNECTION_REQUEST: 503 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 504 // also disconnect if result is 0x0003 - security blocked 505 hci_disconnect_security_block(handle); 506 break; 507 case ECHO_REQUEST: 508 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 509 break; 510 case INFORMATION_REQUEST: 511 switch (infoType){ 512 case 1: { // Connectionless MTU 513 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 514 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 515 break; 516 } 517 case 2: { // Extended Features Supported 518 // extended features request supported, only supporing fixed channel map 519 uint32_t features = 0x80; 520 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 521 break; 522 } 523 case 3: { // Fixed Channels Supported 524 uint8_t map[8]; 525 memset(map, 0, 8); 526 map[0] = 0x01; // L2CAP Signaling Channel 527 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 528 break; 529 } 530 default: 531 // all other types are not supported 532 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 533 break; 534 } 535 break; 536 case COMMAND_REJECT: 537 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 538 #ifdef HAVE_BLE 539 case COMMAND_REJECT_LE: 540 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 541 break; 542 #endif 543 default: 544 // should not happen 545 break; 546 } 547 548 // remove first item 549 signaling_responses_pending--; 550 int i; 551 for (i=0; i < signaling_responses_pending; i++){ 552 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 553 } 554 } 555 556 uint8_t config_options[4]; 557 linked_list_iterator_t it; 558 linked_list_iterator_init(&it, &l2cap_channels); 559 while (linked_list_iterator_has_next(&it)){ 560 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 561 562 if (!hci_can_send_packet_now_using_packet_buffer(HCI_COMMAND_DATA_PACKET)) break; 563 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)) break; 564 565 // log_info("l2cap_run: state %u, var 0x%02x\n", channel->state, channel->state_var); 566 567 switch (channel->state){ 568 569 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 570 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 571 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 572 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 573 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 574 } 575 break; 576 577 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 578 // send connection request - set state first 579 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 580 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 581 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 582 break; 583 584 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 585 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 586 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 587 l2cap_stop_rtx(channel); 588 linked_list_iterator_remove(&it); 589 btstack_memory_l2cap_channel_free(channel); 590 break; 591 592 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 593 channel->state = L2CAP_STATE_CONFIG; 594 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 595 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 596 break; 597 598 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 599 // success, start l2cap handshake 600 channel->local_sig_id = l2cap_next_sig_id(); 601 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 602 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 603 l2cap_start_rtx(channel); 604 break; 605 606 case L2CAP_STATE_CONFIG: 607 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 608 uint16_t flags = 0; 609 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 610 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 611 flags = 1; 612 } else { 613 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 614 } 615 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 616 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 617 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 618 config_options[0] = 1; // MTU 619 config_options[1] = 2; // len param 620 bt_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 621 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 622 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 623 } else { 624 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 625 } 626 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 627 } 628 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 629 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 630 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 631 channel->local_sig_id = l2cap_next_sig_id(); 632 config_options[0] = 1; // MTU 633 config_options[1] = 2; // len param 634 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 635 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 636 l2cap_start_rtx(channel); 637 } 638 if (l2cap_channel_ready_for_open(channel)){ 639 channel->state = L2CAP_STATE_OPEN; 640 l2cap_emit_channel_opened(channel, 0); // success 641 l2cap_emit_credits(channel, 1); 642 } 643 break; 644 645 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 646 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 647 // 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 :) 648 l2cap_finialize_channel_close(channel); // -- remove from list 649 break; 650 651 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 652 channel->local_sig_id = l2cap_next_sig_id(); 653 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 654 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 655 break; 656 default: 657 break; 658 } 659 } 660 } 661 662 uint16_t l2cap_max_mtu(void){ 663 return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE; 664 } 665 666 static void l2cap_handle_connection_complete(uint16_t handle, l2cap_channel_t * channel){ 667 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 668 log_info("l2cap_handle_connection_complete expected state"); 669 // success, start l2cap handshake 670 channel->handle = handle; 671 channel->local_cid = l2cap_next_local_cid(); 672 // check remote SSP feature first 673 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 674 } 675 } 676 677 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 678 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 679 680 // we have been waiting for remote supported features, if both support SSP, 681 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)); 682 if (hci_ssp_supported_on_both_sides(channel->handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 683 // request security level 2 684 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 685 gap_request_security_level(channel->handle, LEVEL_2); 686 return; 687 } 688 // fine, go ahead 689 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 690 } 691 692 // open outgoing L2CAP channel 693 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 694 bd_addr_t address, uint16_t psm, uint16_t mtu){ 695 696 log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 697 698 // alloc structure 699 l2cap_channel_t * chan = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 700 if (!chan) { 701 // emit error event 702 l2cap_channel_t dummy_channel; 703 BD_ADDR_COPY(dummy_channel.address, address); 704 dummy_channel.psm = psm; 705 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 706 return; 707 } 708 // limit local mtu to max acl packet length 709 if (mtu > l2cap_max_mtu()) { 710 mtu = l2cap_max_mtu(); 711 } 712 713 // fill in 714 BD_ADDR_COPY(chan->address, address); 715 chan->psm = psm; 716 chan->handle = 0; 717 chan->connection = connection; 718 chan->packet_handler = packet_handler; 719 chan->remote_mtu = L2CAP_MINIMAL_MTU; 720 chan->local_mtu = mtu; 721 chan->packets_granted = 0; 722 723 // set initial state 724 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 725 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 726 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 727 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 728 chan->required_security_level = LEVEL_0; 729 730 // add to connections list 731 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 732 733 // check if hci connection is already usable 734 hci_connection_t * conn = hci_connection_for_bd_addr_and_type((bd_addr_t*)address, BD_ADDR_TYPE_CLASSIC); 735 if (conn){ 736 log_info("l2cap_create_channel_internal, hci connection already exists"); 737 l2cap_handle_connection_complete(conn->con_handle, chan); 738 // check ir remote supported fearures are already received 739 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 740 l2cap_handle_remote_supported_features_received(chan); 741 } 742 } 743 744 l2cap_run(); 745 } 746 747 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 748 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 749 // find channel for local_cid 750 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 751 if (channel) { 752 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 753 } 754 // process 755 l2cap_run(); 756 } 757 758 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 759 linked_list_iterator_t it; 760 linked_list_iterator_init(&it, &l2cap_channels); 761 while (linked_list_iterator_has_next(&it)){ 762 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 763 if ( BD_ADDR_CMP( channel->address, address) != 0) continue; 764 // channel for this address found 765 switch (channel->state){ 766 case L2CAP_STATE_WAIT_CONNECTION_COMPLETE: 767 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 768 // failure, forward error code 769 l2cap_emit_channel_opened(channel, status); 770 // discard channel 771 l2cap_stop_rtx(channel); 772 linked_list_iterator_remove(&it); 773 btstack_memory_l2cap_channel_free(channel); 774 break; 775 default: 776 break; 777 } 778 } 779 } 780 781 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 782 linked_list_iterator_t it; 783 linked_list_iterator_init(&it, &l2cap_channels); 784 while (linked_list_iterator_has_next(&it)){ 785 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 786 if ( ! BD_ADDR_CMP( channel->address, address) ){ 787 l2cap_handle_connection_complete(handle, channel); 788 } 789 } 790 // process 791 l2cap_run(); 792 } 793 794 void l2cap_event_handler(uint8_t *packet, uint16_t size){ 795 796 bd_addr_t address; 797 hci_con_handle_t handle; 798 linked_list_iterator_t it; 799 int hci_con_used; 800 801 switch(packet[0]){ 802 803 // handle connection complete events 804 case HCI_EVENT_CONNECTION_COMPLETE: 805 bt_flip_addr(address, &packet[5]); 806 if (packet[2] == 0){ 807 handle = READ_BT_16(packet, 3); 808 l2cap_handle_connection_success_for_addr(address, handle); 809 } else { 810 l2cap_handle_connection_failed_for_addr(address, packet[2]); 811 } 812 break; 813 814 // handle successful create connection cancel command 815 case HCI_EVENT_COMMAND_COMPLETE: 816 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 817 if (packet[5] == 0){ 818 bt_flip_addr(address, &packet[6]); 819 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 820 l2cap_handle_connection_failed_for_addr(address, 0x16); 821 } 822 } 823 l2cap_run(); // try sending signaling packets first 824 break; 825 826 case HCI_EVENT_COMMAND_STATUS: 827 l2cap_run(); // try sending signaling packets first 828 break; 829 830 // handle disconnection complete events 831 case HCI_EVENT_DISCONNECTION_COMPLETE: 832 // send l2cap disconnect events for all channels on this handle and free them 833 handle = READ_BT_16(packet, 3); 834 linked_list_iterator_init(&it, &l2cap_channels); 835 while (linked_list_iterator_has_next(&it)){ 836 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 837 if (channel->handle != handle) continue; 838 l2cap_emit_channel_closed(channel); 839 l2cap_stop_rtx(channel); 840 linked_list_iterator_remove(&it); 841 btstack_memory_l2cap_channel_free(channel); 842 } 843 break; 844 845 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 846 l2cap_run(); // try sending signaling packets first 847 l2cap_hand_out_credits(); 848 break; 849 850 // HCI Connection Timeouts 851 case L2CAP_EVENT_TIMEOUT_CHECK: 852 handle = READ_BT_16(packet, 2); 853 if (hci_authentication_active_for_handle(handle)) break; 854 hci_con_used = 0; 855 linked_list_iterator_init(&it, &l2cap_channels); 856 while (linked_list_iterator_has_next(&it)){ 857 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 858 if (channel->handle != handle) continue; 859 hci_con_used = 1; 860 break; 861 } 862 if (hci_con_used) break; 863 if (!hci_can_send_packet_now_using_packet_buffer(HCI_COMMAND_DATA_PACKET)) break; 864 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 865 break; 866 867 case DAEMON_EVENT_HCI_PACKET_SENT: 868 linked_list_iterator_init(&it, &l2cap_channels); 869 while (linked_list_iterator_has_next(&it)){ 870 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 871 if (!channel->packet_handler) continue; 872 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 873 } 874 if (attribute_protocol_packet_handler) { 875 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 876 } 877 if (security_protocol_packet_handler) { 878 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 879 } 880 break; 881 882 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 883 handle = READ_BT_16(packet, 3); 884 linked_list_iterator_init(&it, &l2cap_channels); 885 while (linked_list_iterator_has_next(&it)){ 886 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 887 if (channel->handle != handle) continue; 888 l2cap_handle_remote_supported_features_received(channel); 889 break; 890 } 891 break; 892 893 case GAP_SECURITY_LEVEL: 894 handle = READ_BT_16(packet, 2); 895 log_info("l2cap - security level update"); 896 linked_list_iterator_init(&it, &l2cap_channels); 897 while (linked_list_iterator_has_next(&it)){ 898 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 899 if (channel->handle != handle) continue; 900 901 log_info("l2cap - state %u", channel->state); 902 903 gap_security_level_t actual_level = packet[4]; 904 gap_security_level_t required_level = channel->required_security_level; 905 906 switch (channel->state){ 907 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 908 if (actual_level >= required_level){ 909 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 910 l2cap_emit_connection_request(channel); 911 } else { 912 channel->reason = 0x03; // security block 913 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 914 } 915 break; 916 917 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 918 if (actual_level >= required_level){ 919 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 920 } else { 921 // disconnnect, authentication not good enough 922 hci_disconnect_security_block(handle); 923 } 924 break; 925 926 default: 927 break; 928 } 929 } 930 break; 931 932 default: 933 break; 934 } 935 936 // pass on: main packet handler, att and sm packet handlers 937 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 938 if (attribute_protocol_packet_handler){ 939 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 940 } 941 if (security_protocol_packet_handler) { 942 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 943 } 944 945 l2cap_run(); 946 } 947 948 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 949 channel->remote_sig_id = identifier; 950 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 951 l2cap_run(); 952 } 953 954 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 955 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 956 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 957 signaling_responses[signaling_responses_pending].handle = handle; 958 signaling_responses[signaling_responses_pending].code = code; 959 signaling_responses[signaling_responses_pending].sig_id = sig_id; 960 signaling_responses[signaling_responses_pending].data = data; 961 signaling_responses_pending++; 962 l2cap_run(); 963 } 964 } 965 966 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 967 968 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x\n", handle, psm, source_cid); 969 l2cap_service_t *service = l2cap_get_service(psm); 970 if (!service) { 971 // 0x0002 PSM not supported 972 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 973 return; 974 } 975 976 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 977 if (!hci_connection) { 978 // 979 log_error("no hci_connection for handle %u\n", handle); 980 return; 981 } 982 983 // reject connection (0x03 security block) and disconnect if both have SSP, connection is not encrypted and PSM != SDP 984 if ( hci_ssp_supported_on_both_sides(handle) 985 && gap_security_level(handle) == LEVEL_0 986 && !l2cap_security_level_0_allowed_for_PSM(psm)){ 987 988 // 0x0003 Security Block 989 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0003); 990 return; 991 } 992 993 994 // alloc structure 995 // log_info("l2cap_handle_connection_request register channel\n"); 996 l2cap_channel_t * channel = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 997 if (!channel){ 998 // 0x0004 No resources available 999 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 1000 return; 1001 } 1002 1003 // fill in 1004 BD_ADDR_COPY(channel->address, hci_connection->address); 1005 channel->psm = psm; 1006 channel->handle = handle; 1007 channel->connection = service->connection; 1008 channel->packet_handler = service->packet_handler; 1009 channel->local_cid = l2cap_next_local_cid(); 1010 channel->remote_cid = source_cid; 1011 channel->local_mtu = service->mtu; 1012 channel->remote_mtu = L2CAP_DEFAULT_MTU; 1013 channel->packets_granted = 0; 1014 channel->remote_sig_id = sig_id; 1015 channel->required_security_level = service->required_security_level; 1016 1017 // limit local mtu to max acl packet length 1018 if (channel->local_mtu > l2cap_max_mtu()) { 1019 channel->local_mtu = l2cap_max_mtu(); 1020 } 1021 1022 // set initial state 1023 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1024 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 1025 1026 // add to connections list 1027 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 1028 1029 // assert security requirements 1030 gap_request_security_level(handle, channel->required_security_level); 1031 } 1032 1033 void l2cap_accept_connection_internal(uint16_t local_cid){ 1034 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1035 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1036 if (!channel) { 1037 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 1038 return; 1039 } 1040 1041 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1042 1043 // process 1044 l2cap_run(); 1045 } 1046 1047 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 1048 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); 1049 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1050 if (!channel) { 1051 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 1052 return; 1053 } 1054 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1055 channel->reason = reason; 1056 l2cap_run(); 1057 } 1058 1059 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1060 1061 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1062 1063 uint16_t flags = READ_BT_16(command, 6); 1064 if (flags & 1) { 1065 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1066 } 1067 1068 // accept the other's configuration options 1069 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1070 uint16_t pos = 8; 1071 while (pos < end_pos){ 1072 uint8_t option_hint = command[pos] >> 7; 1073 uint8_t option_type = command[pos] & 0x7f; 1074 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1075 pos++; 1076 uint8_t length = command[pos++]; 1077 // MTU { type(8): 1, len(8):2, MTU(16) } 1078 if (option_type == 1 && length == 2){ 1079 channel->remote_mtu = READ_BT_16(command, pos); 1080 // log_info("l2cap cid 0x%02x, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 1081 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1082 } 1083 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1084 if (option_type == 2 && length == 2){ 1085 channel->flush_timeout = READ_BT_16(command, pos); 1086 } 1087 // check for unknown options 1088 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1089 log_info("l2cap cid %u, unknown options", channel->local_cid); 1090 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1091 } 1092 pos += length; 1093 } 1094 } 1095 1096 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1097 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 1098 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1099 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1100 return 1; 1101 } 1102 1103 1104 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1105 1106 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1107 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1108 uint16_t result = 0; 1109 1110 log_info("L2CAP signaling handler code %u, state %u\n", code, channel->state); 1111 1112 // handle DISCONNECT REQUESTS seperately 1113 if (code == DISCONNECTION_REQUEST){ 1114 switch (channel->state){ 1115 case L2CAP_STATE_CONFIG: 1116 case L2CAP_STATE_OPEN: 1117 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1118 case L2CAP_STATE_WAIT_DISCONNECT: 1119 l2cap_handle_disconnect_request(channel, identifier); 1120 break; 1121 1122 default: 1123 // ignore in other states 1124 break; 1125 } 1126 return; 1127 } 1128 1129 // @STATEMACHINE(l2cap) 1130 switch (channel->state) { 1131 1132 case L2CAP_STATE_WAIT_CONNECT_RSP: 1133 switch (code){ 1134 case CONNECTION_RESPONSE: 1135 l2cap_stop_rtx(channel); 1136 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1137 switch (result) { 1138 case 0: 1139 // successful connection 1140 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1141 channel->state = L2CAP_STATE_CONFIG; 1142 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1143 break; 1144 case 1: 1145 // connection pending. get some coffee, but start the ERTX 1146 l2cap_start_ertx(channel); 1147 break; 1148 default: 1149 // channel closed 1150 channel->state = L2CAP_STATE_CLOSED; 1151 // map l2cap connection response result to BTstack status enumeration 1152 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1153 1154 // drop link key if security block 1155 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1156 hci_drop_link_key_for_bd_addr(&channel->address); 1157 } 1158 1159 // discard channel 1160 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1161 btstack_memory_l2cap_channel_free(channel); 1162 break; 1163 } 1164 break; 1165 1166 default: 1167 //@TODO: implement other signaling packets 1168 break; 1169 } 1170 break; 1171 1172 case L2CAP_STATE_CONFIG: 1173 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1174 switch (code) { 1175 case CONFIGURE_REQUEST: 1176 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1177 l2cap_signaling_handle_configure_request(channel, command); 1178 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1179 // only done if continuation not set 1180 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1181 } 1182 break; 1183 case CONFIGURE_RESPONSE: 1184 l2cap_stop_rtx(channel); 1185 switch (result){ 1186 case 0: // success 1187 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1188 break; 1189 case 4: // pending 1190 l2cap_start_ertx(channel); 1191 break; 1192 default: 1193 // retry on negative result 1194 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1195 break; 1196 } 1197 break; 1198 default: 1199 break; 1200 } 1201 if (l2cap_channel_ready_for_open(channel)){ 1202 // for open: 1203 channel->state = L2CAP_STATE_OPEN; 1204 l2cap_emit_channel_opened(channel, 0); 1205 l2cap_emit_credits(channel, 1); 1206 } 1207 break; 1208 1209 case L2CAP_STATE_WAIT_DISCONNECT: 1210 switch (code) { 1211 case DISCONNECTION_RESPONSE: 1212 l2cap_finialize_channel_close(channel); 1213 break; 1214 default: 1215 //@TODO: implement other signaling packets 1216 break; 1217 } 1218 break; 1219 1220 case L2CAP_STATE_CLOSED: 1221 // @TODO handle incoming requests 1222 break; 1223 1224 case L2CAP_STATE_OPEN: 1225 //@TODO: implement other signaling packets, e.g. re-configure 1226 break; 1227 default: 1228 break; 1229 } 1230 // log_info("new state %u\n", channel->state); 1231 } 1232 1233 1234 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1235 1236 // get code, signalind identifier and command len 1237 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1238 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1239 1240 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1241 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1242 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1243 return; 1244 } 1245 1246 // general commands without an assigned channel 1247 switch(code) { 1248 1249 case CONNECTION_REQUEST: { 1250 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1251 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1252 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1253 return; 1254 } 1255 1256 case ECHO_REQUEST: 1257 l2cap_register_signaling_response(handle, code, sig_id, 0); 1258 return; 1259 1260 case INFORMATION_REQUEST: { 1261 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1262 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1263 return; 1264 } 1265 1266 default: 1267 break; 1268 } 1269 1270 1271 // Get potential destination CID 1272 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1273 1274 // Find channel for this sig_id and connection handle 1275 linked_list_iterator_t it; 1276 linked_list_iterator_init(&it, &l2cap_channels); 1277 while (linked_list_iterator_has_next(&it)){ 1278 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 1279 if (channel->handle != handle) continue; 1280 if (code & 1) { 1281 // match odd commands (responses) by previous signaling identifier 1282 if (channel->local_sig_id == sig_id) { 1283 l2cap_signaling_handler_channel(channel, command); 1284 break; 1285 } 1286 } else { 1287 // match even commands (requests) by local channel id 1288 if (channel->local_cid == dest_cid) { 1289 l2cap_signaling_handler_channel(channel, command); 1290 break; 1291 } 1292 } 1293 } 1294 } 1295 1296 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 1297 1298 // Get Channel ID 1299 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1300 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1301 1302 switch (channel_id) { 1303 1304 case L2CAP_CID_SIGNALING: { 1305 1306 uint16_t command_offset = 8; 1307 while (command_offset < size) { 1308 1309 // handle signaling commands 1310 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1311 1312 // increment command_offset 1313 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1314 } 1315 break; 1316 } 1317 1318 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1319 if (attribute_protocol_packet_handler) { 1320 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1321 } 1322 break; 1323 1324 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1325 if (security_protocol_packet_handler) { 1326 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1327 } 1328 break; 1329 1330 case L2CAP_CID_SIGNALING_LE: { 1331 // not implemented yet for LE Peripheral 1332 uint8_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1333 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1334 break; 1335 } 1336 1337 default: { 1338 // Find channel for this channel_id and connection handle 1339 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1340 if (channel) { 1341 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1342 } 1343 break; 1344 } 1345 } 1346 } 1347 1348 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1349 switch (packet_type) { 1350 case HCI_EVENT_PACKET: 1351 l2cap_event_handler(packet, size); 1352 break; 1353 case HCI_ACL_DATA_PACKET: 1354 l2cap_acl_handler(packet, size); 1355 break; 1356 default: 1357 break; 1358 } 1359 l2cap_run(); 1360 } 1361 1362 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1363 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1364 channel->state = L2CAP_STATE_CLOSED; 1365 l2cap_emit_channel_closed(channel); 1366 // discard channel 1367 l2cap_stop_rtx(channel); 1368 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1369 btstack_memory_l2cap_channel_free(channel); 1370 } 1371 1372 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1373 linked_list_iterator_t it; 1374 linked_list_iterator_init(&it, &l2cap_services); 1375 while (linked_list_iterator_has_next(&it)){ 1376 l2cap_service_t * service = (l2cap_service_t *) linked_list_iterator_next(&it); 1377 if ( service->psm == psm){ 1378 return service; 1379 }; 1380 } 1381 return NULL; 1382 } 1383 1384 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){ 1385 1386 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1387 1388 // check for alread registered psm 1389 // TODO: emit error event 1390 l2cap_service_t *service = l2cap_get_service(psm); 1391 if (service) { 1392 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 1393 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1394 return; 1395 } 1396 1397 // alloc structure 1398 // TODO: emit error event 1399 service = (l2cap_service_t *) btstack_memory_l2cap_service_get(); 1400 if (!service) { 1401 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 1402 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1403 return; 1404 } 1405 1406 // fill in 1407 service->psm = psm; 1408 service->mtu = mtu; 1409 service->connection = connection; 1410 service->packet_handler = packet_handler; 1411 service->required_security_level = security_level; 1412 1413 // add to services list 1414 linked_list_add(&l2cap_services, (linked_item_t *) service); 1415 1416 // enable page scan 1417 hci_connectable_control(1); 1418 1419 // done 1420 l2cap_emit_service_registered(connection, 0, psm); 1421 } 1422 1423 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1424 1425 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1426 1427 l2cap_service_t *service = l2cap_get_service(psm); 1428 if (!service) return; 1429 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1430 btstack_memory_l2cap_service_free(service); 1431 1432 // disable page scan when no services registered 1433 if (!linked_list_empty(&l2cap_services)) return; 1434 hci_connectable_control(0); 1435 } 1436 1437 // 1438 void l2cap_close_connection(void *connection){ 1439 1440 linked_list_iterator_t it; 1441 1442 // close open channels 1443 linked_list_iterator_init(&it, &l2cap_channels); 1444 while (linked_list_iterator_has_next(&it)){ 1445 l2cap_channel_t * channel = (l2cap_channel_t *) linked_list_iterator_next(&it); 1446 if (channel->connection != connection) continue; 1447 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1448 } 1449 1450 // unregister services 1451 linked_list_iterator_init(&it, &l2cap_services); 1452 while (linked_list_iterator_has_next(&it)){ 1453 l2cap_service_t * service = (l2cap_service_t *) linked_list_iterator_next(&it); 1454 if (service->connection != connection) continue; 1455 linked_list_iterator_remove(&it); 1456 btstack_memory_l2cap_service_free(service); 1457 } 1458 1459 // process 1460 l2cap_run(); 1461 } 1462 1463 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1464 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1465 switch(channel_id){ 1466 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1467 attribute_protocol_packet_handler = packet_handler; 1468 break; 1469 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1470 security_protocol_packet_handler = packet_handler; 1471 break; 1472 } 1473 } 1474 1475 #ifdef HAVE_BLE 1476 // Request LE connection parameter update 1477 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){ 1478 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 1479 log_info("l2cap_send_signaling_packet, cannot send\n"); 1480 return BTSTACK_ACL_BUFFERS_FULL; 1481 } 1482 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 1483 hci_reserve_packet_buffer(); 1484 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1485 uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); 1486 return hci_send_acl_packet_buffer(len); 1487 } 1488 #endif 1489 1490