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_item_t *it; 210 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 211 if (!hci_number_free_acl_slots()) return; 212 l2cap_channel_t * channel = (l2cap_channel_t *) it; 213 if (channel->state != L2CAP_STATE_OPEN) continue; 214 if (hci_number_outgoing_packets(channel->handle) < NR_BUFFERED_ACL_PACKETS && channel->packets_granted == 0) { 215 l2cap_emit_credits(channel, 1); 216 } 217 } 218 } 219 220 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 221 linked_item_t *it; 222 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 223 l2cap_channel_t * channel = (l2cap_channel_t *) it; 224 if ( channel->local_cid == local_cid) { 225 return channel; 226 } 227 } 228 return NULL; 229 } 230 231 int l2cap_can_send_packet_now(uint16_t local_cid){ 232 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 233 if (!channel) return 0; 234 if (!channel->packets_granted) return 0; 235 return hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET); 236 } 237 238 int l2cap_can_send_connectionless_packet_now(void){ 239 return hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET); 240 } 241 242 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 243 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 244 if (channel) { 245 return channel->remote_mtu; 246 } 247 return 0; 248 } 249 250 static l2cap_channel_t * l2cap_channel_for_rtx_timer(timer_source_t * ts){ 251 linked_item_t *it; 252 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 253 l2cap_channel_t * channel = (l2cap_channel_t *) it; 254 if ( &channel->rtx == ts) { 255 return channel; 256 } 257 } 258 return NULL; 259 } 260 261 static void l2cap_rtx_timeout(timer_source_t * ts){ 262 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 263 if (!ts) return; 264 265 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 266 267 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 268 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 269 // notify client 270 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 271 272 // discard channel 273 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 274 btstack_memory_l2cap_channel_free(channel); 275 } 276 277 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 278 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 279 run_loop_remove_timer(&channel->rtx); 280 } 281 282 static void l2cap_start_rtx(l2cap_channel_t * channel){ 283 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 284 l2cap_stop_rtx(channel); 285 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 286 run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 287 run_loop_add_timer(&channel->rtx); 288 } 289 290 static void l2cap_start_ertx(l2cap_channel_t * channel){ 291 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 292 l2cap_stop_rtx(channel); 293 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 294 run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 295 run_loop_add_timer(&channel->rtx); 296 } 297 298 void l2cap_require_security_level_2_for_outgoing_sdp(){ 299 require_security_level2_for_outgoing_sdp = 1; 300 } 301 302 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 303 return (psm == PSM_SDP) && (!require_security_level2_for_outgoing_sdp); 304 } 305 306 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 307 308 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 309 log_info("l2cap_send_signaling_packet, cannot send\n"); 310 return BTSTACK_ACL_BUFFERS_FULL; 311 } 312 313 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 314 hci_reserve_packet_buffer(); 315 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 316 va_list argptr; 317 va_start(argptr, identifier); 318 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 319 va_end(argptr); 320 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 321 return hci_send_acl_packet(acl_buffer, len); 322 } 323 324 #ifdef HAVE_BLE 325 int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 326 327 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 328 log_info("l2cap_send_signaling_packet, cannot send\n"); 329 return BTSTACK_ACL_BUFFERS_FULL; 330 } 331 332 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 333 hci_reserve_packet_buffer(); 334 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 335 va_list argptr; 336 va_start(argptr, identifier); 337 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 338 va_end(argptr); 339 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 340 return hci_send_acl_packet(acl_buffer, len); 341 } 342 #endif 343 344 uint8_t *l2cap_get_outgoing_buffer(void){ 345 return hci_get_outgoing_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 346 } 347 348 int l2cap_reserve_packet_buffer(void){ 349 return hci_reserve_packet_buffer(); 350 } 351 352 void l2cap_release_packet_buffer(void){ 353 hci_release_packet_buffer(); 354 } 355 356 357 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 358 359 if (!hci_is_packet_buffer_reserved()){ 360 log_error("l2cap_send_prepared called without reserving packet first"); 361 return BTSTACK_ACL_BUFFERS_FULL; 362 } 363 364 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 365 log_info("l2cap_send_prepared cid 0x%02x, cannot send\n", local_cid); 366 return BTSTACK_ACL_BUFFERS_FULL; 367 } 368 369 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 370 if (!channel) { 371 log_error("l2cap_send_prepared no channel for cid 0x%02x\n", local_cid); 372 return -1; // TODO: define error 373 } 374 375 if (channel->packets_granted == 0){ 376 log_error("l2cap_send_prepared cid 0x%02x, no credits!\n", local_cid); 377 return -1; // TODO: define error 378 } 379 380 --channel->packets_granted; 381 382 log_debug("l2cap_send_prepared cid 0x%02x, handle %u, 1 credit used, credits left %u;\n", 383 local_cid, channel->handle, channel->packets_granted); 384 385 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 386 387 // 0 - Connection handle : PB=10 : BC=00 388 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 389 // 2 - ACL length 390 bt_store_16(acl_buffer, 2, len + 4); 391 // 4 - L2CAP packet length 392 bt_store_16(acl_buffer, 4, len + 0); 393 // 6 - L2CAP channel DEST 394 bt_store_16(acl_buffer, 6, channel->remote_cid); 395 // send 396 int err = hci_send_acl_packet(acl_buffer, len+8); 397 398 l2cap_hand_out_credits(); 399 400 return err; 401 } 402 403 int l2cap_send_prepared_connectionless(uint16_t handle, uint16_t cid, uint16_t len){ 404 405 if (!hci_is_packet_buffer_reserved()){ 406 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 407 return BTSTACK_ACL_BUFFERS_FULL; 408 } 409 410 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 411 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send\n", handle, cid); 412 return BTSTACK_ACL_BUFFERS_FULL; 413 } 414 415 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x\n", handle, cid); 416 417 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 418 419 // 0 - Connection handle : PB=10 : BC=00 420 bt_store_16(acl_buffer, 0, handle | (2 << 12) | (0 << 14)); 421 // 2 - ACL length 422 bt_store_16(acl_buffer, 2, len + 4); 423 // 4 - L2CAP packet length 424 bt_store_16(acl_buffer, 4, len + 0); 425 // 6 - L2CAP channel DEST 426 bt_store_16(acl_buffer, 6, cid); 427 // send 428 int err = hci_send_acl_packet(acl_buffer, len+8); 429 430 l2cap_hand_out_credits(); 431 432 return err; 433 } 434 435 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 436 437 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 438 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", local_cid); 439 return BTSTACK_ACL_BUFFERS_FULL; 440 } 441 442 hci_reserve_packet_buffer(); 443 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 444 445 memcpy(&acl_buffer[8], data, len); 446 447 return l2cap_send_prepared(local_cid, len); 448 } 449 450 int l2cap_send_connectionless(uint16_t handle, uint16_t cid, uint8_t *data, uint16_t len){ 451 452 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 453 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", cid); 454 return BTSTACK_ACL_BUFFERS_FULL; 455 } 456 457 hci_reserve_packet_buffer(); 458 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 459 460 memcpy(&acl_buffer[8], data, len); 461 462 return l2cap_send_prepared_connectionless(handle, cid, len); 463 } 464 465 int l2cap_send_echo_request(uint16_t handle, uint8_t *data, uint16_t len){ 466 return l2cap_send_signaling_packet(handle, ECHO_REQUEST, 0x77, len, data); 467 } 468 469 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 470 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 471 } 472 473 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 474 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 475 } 476 477 478 479 // MARK: L2CAP_RUN 480 // process outstanding signaling tasks 481 void l2cap_run(void){ 482 483 // check pending signaling responses 484 while (signaling_responses_pending){ 485 486 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)) break; 487 488 hci_con_handle_t handle = signaling_responses[0].handle; 489 uint8_t sig_id = signaling_responses[0].sig_id; 490 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 491 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 492 493 switch (signaling_responses[0].code){ 494 case CONNECTION_REQUEST: 495 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 496 // also disconnect if result is 0x0003 - security blocked 497 hci_disconnect_security_block(handle); 498 break; 499 case ECHO_REQUEST: 500 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 501 break; 502 case INFORMATION_REQUEST: 503 switch (infoType){ 504 case 1: { // Connectionless MTU 505 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 506 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 507 break; 508 } 509 case 2: { // Extended Features Supported 510 // extended features request supported, only supporing fixed channel map 511 uint32_t features = 0x80; 512 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 513 break; 514 } 515 case 3: { // Fixed Channels Supported 516 uint8_t map[8]; 517 memset(map, 0, 8); 518 map[0] = 0x01; // L2CAP Signaling Channel 519 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 520 break; 521 } 522 default: 523 // all other types are not supported 524 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 525 break; 526 } 527 break; 528 case COMMAND_REJECT: 529 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 530 #ifdef HAVE_BLE 531 case COMMAND_REJECT_LE: 532 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 533 break; 534 #endif 535 default: 536 // should not happen 537 break; 538 } 539 540 // remove first item 541 signaling_responses_pending--; 542 int i; 543 for (i=0; i < signaling_responses_pending; i++){ 544 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 545 } 546 } 547 548 uint8_t config_options[4]; 549 linked_item_t *it; 550 linked_item_t *next; 551 for (it = (linked_item_t *) l2cap_channels; it ; it = next){ 552 next = it->next; // cache next item as current item might get freed 553 554 if (!hci_can_send_packet_now_using_packet_buffer(HCI_COMMAND_DATA_PACKET)) break; 555 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)) break; 556 557 l2cap_channel_t * channel = (l2cap_channel_t *) it; 558 559 // log_info("l2cap_run: state %u, var 0x%02x\n", channel->state, channel->state_var); 560 561 562 switch (channel->state){ 563 564 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 565 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 566 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 567 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 568 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 569 } 570 break; 571 572 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 573 // send connection request - set state first 574 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 575 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 576 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 577 break; 578 579 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 580 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 581 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 582 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); // -- remove from list 583 btstack_memory_l2cap_channel_free(channel); 584 break; 585 586 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 587 channel->state = L2CAP_STATE_CONFIG; 588 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 589 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 590 break; 591 592 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 593 // success, start l2cap handshake 594 channel->local_sig_id = l2cap_next_sig_id(); 595 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 596 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 597 l2cap_start_rtx(channel); 598 break; 599 600 case L2CAP_STATE_CONFIG: 601 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 602 uint16_t flags = 0; 603 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 604 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 605 flags = 1; 606 } else { 607 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 608 } 609 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 610 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 611 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 612 config_options[0] = 1; // MTU 613 config_options[1] = 2; // len param 614 bt_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 615 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 616 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 617 } else { 618 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 619 } 620 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 621 } 622 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 623 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 624 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 625 channel->local_sig_id = l2cap_next_sig_id(); 626 config_options[0] = 1; // MTU 627 config_options[1] = 2; // len param 628 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 629 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 630 l2cap_start_rtx(channel); 631 } 632 if (l2cap_channel_ready_for_open(channel)){ 633 channel->state = L2CAP_STATE_OPEN; 634 l2cap_emit_channel_opened(channel, 0); // success 635 l2cap_emit_credits(channel, 1); 636 } 637 break; 638 639 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 640 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 641 // 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 :) 642 l2cap_finialize_channel_close(channel); // -- remove from list 643 break; 644 645 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 646 channel->local_sig_id = l2cap_next_sig_id(); 647 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 648 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 649 break; 650 default: 651 break; 652 } 653 } 654 } 655 656 uint16_t l2cap_max_mtu(void){ 657 return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE; 658 } 659 660 static void l2cap_handle_connection_complete(uint16_t handle, l2cap_channel_t * channel){ 661 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 662 log_info("l2cap_handle_connection_complete expected state"); 663 // success, start l2cap handshake 664 channel->handle = handle; 665 channel->local_cid = l2cap_next_local_cid(); 666 // check remote SSP feature first 667 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 668 } 669 } 670 671 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 672 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 673 674 // we have been waiting for remote supported features, if both support SSP, 675 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)); 676 if (hci_ssp_supported_on_both_sides(channel->handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 677 // request security level 2 678 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 679 gap_request_security_level(channel->handle, LEVEL_2); 680 return; 681 } 682 // fine, go ahead 683 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 684 } 685 686 // open outgoing L2CAP channel 687 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 688 bd_addr_t address, uint16_t psm, uint16_t mtu){ 689 690 log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 691 692 // alloc structure 693 l2cap_channel_t * chan = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 694 if (!chan) { 695 // emit error event 696 l2cap_channel_t dummy_channel; 697 BD_ADDR_COPY(dummy_channel.address, address); 698 dummy_channel.psm = psm; 699 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 700 return; 701 } 702 // limit local mtu to max acl packet length 703 if (mtu > l2cap_max_mtu()) { 704 mtu = l2cap_max_mtu(); 705 } 706 707 // fill in 708 BD_ADDR_COPY(chan->address, address); 709 chan->psm = psm; 710 chan->handle = 0; 711 chan->connection = connection; 712 chan->packet_handler = packet_handler; 713 chan->remote_mtu = L2CAP_MINIMAL_MTU; 714 chan->local_mtu = mtu; 715 chan->packets_granted = 0; 716 717 // set initial state 718 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 719 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 720 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 721 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 722 chan->required_security_level = LEVEL_0; 723 724 // add to connections list 725 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 726 727 // check if hci connection is already usable 728 hci_connection_t * conn = hci_connection_for_bd_addr_and_type((bd_addr_t*)address, BD_ADDR_TYPE_CLASSIC); 729 if (conn){ 730 log_info("l2cap_create_channel_internal, hci connection already exists"); 731 l2cap_handle_connection_complete(conn->con_handle, chan); 732 // check ir remote supported fearures are already received 733 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 734 l2cap_handle_remote_supported_features_received(chan); 735 } 736 } 737 738 l2cap_run(); 739 } 740 741 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 742 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 743 // find channel for local_cid 744 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 745 if (channel) { 746 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 747 } 748 // process 749 l2cap_run(); 750 } 751 752 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 753 linked_item_t *it = (linked_item_t *) &l2cap_channels; 754 while (it->next){ 755 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 756 if ( ! BD_ADDR_CMP( channel->address, address) ){ 757 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 758 // failure, forward error code 759 l2cap_emit_channel_opened(channel, status); 760 // discard channel 761 it->next = it->next->next; 762 btstack_memory_l2cap_channel_free(channel); 763 } 764 } else { 765 it = it->next; 766 } 767 } 768 } 769 770 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 771 linked_item_t *it; 772 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 773 l2cap_channel_t * channel = (l2cap_channel_t *) it; 774 if ( ! BD_ADDR_CMP( channel->address, address) ){ 775 l2cap_handle_connection_complete(handle, channel); 776 } 777 } 778 // process 779 l2cap_run(); 780 } 781 782 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 783 784 bd_addr_t address; 785 hci_con_handle_t handle; 786 l2cap_channel_t * channel; 787 linked_item_t *it; 788 int hci_con_used; 789 790 switch(packet[0]){ 791 792 // handle connection complete events 793 case HCI_EVENT_CONNECTION_COMPLETE: 794 bt_flip_addr(address, &packet[5]); 795 if (packet[2] == 0){ 796 handle = READ_BT_16(packet, 3); 797 l2cap_handle_connection_success_for_addr(address, handle); 798 } else { 799 l2cap_handle_connection_failed_for_addr(address, packet[2]); 800 } 801 break; 802 803 // handle successful create connection cancel command 804 case HCI_EVENT_COMMAND_COMPLETE: 805 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 806 if (packet[5] == 0){ 807 bt_flip_addr(address, &packet[6]); 808 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 809 l2cap_handle_connection_failed_for_addr(address, 0x16); 810 } 811 } 812 l2cap_run(); // try sending signaling packets first 813 break; 814 815 case HCI_EVENT_COMMAND_STATUS: 816 l2cap_run(); // try sending signaling packets first 817 break; 818 819 // handle disconnection complete events 820 case HCI_EVENT_DISCONNECTION_COMPLETE: 821 // send l2cap disconnect events for all channels on this handle 822 handle = READ_BT_16(packet, 3); 823 it = (linked_item_t *) &l2cap_channels; 824 while (it->next){ 825 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 826 if ( channel->handle == handle ){ 827 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 828 it->next = it->next->next; 829 l2cap_emit_channel_closed(channel); 830 btstack_memory_l2cap_channel_free(channel); 831 } else { 832 it = it->next; 833 } 834 } 835 break; 836 837 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 838 l2cap_run(); // try sending signaling packets first 839 l2cap_hand_out_credits(); 840 break; 841 842 // HCI Connection Timeouts 843 case L2CAP_EVENT_TIMEOUT_CHECK: 844 handle = READ_BT_16(packet, 2); 845 if (hci_authentication_active_for_handle(handle)) break; 846 hci_con_used = 0; 847 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 848 channel = (l2cap_channel_t *) it; 849 if (channel->handle == handle) { 850 hci_con_used = 1; 851 } 852 } 853 if (hci_con_used) break; 854 if (!hci_can_send_packet_now_using_packet_buffer(HCI_COMMAND_DATA_PACKET)) break; 855 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 856 break; 857 858 case DAEMON_EVENT_HCI_PACKET_SENT: 859 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 860 channel = (l2cap_channel_t *) it; 861 if (channel->packet_handler) { 862 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 863 } 864 } 865 if (attribute_protocol_packet_handler) { 866 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 867 } 868 if (security_protocol_packet_handler) { 869 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 870 } 871 break; 872 873 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 874 handle = READ_BT_16(packet, 3); 875 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 876 channel = (l2cap_channel_t *) it; 877 if (channel->handle != handle) continue; 878 l2cap_handle_remote_supported_features_received(channel); 879 break; 880 } 881 882 case GAP_SECURITY_LEVEL: 883 handle = READ_BT_16(packet, 2); 884 log_info("l2cap - security level update"); 885 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 886 channel = (l2cap_channel_t *) it; 887 if (channel->handle != handle) continue; 888 889 log_info("l2cap - state %u", channel->state); 890 891 gap_security_level_t actual_level = packet[4]; 892 gap_security_level_t required_level = channel->required_security_level; 893 894 switch (channel->state){ 895 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 896 if (actual_level >= required_level){ 897 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 898 l2cap_emit_connection_request(channel); 899 } else { 900 channel->reason = 0x03; // security block 901 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 902 } 903 break; 904 905 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 906 if (actual_level >= required_level){ 907 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 908 } else { 909 // disconnnect, authentication not good enough 910 hci_disconnect_security_block(handle); 911 } 912 break; 913 914 default: 915 break; 916 } 917 } 918 break; 919 920 default: 921 break; 922 } 923 924 // pass on 925 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 926 927 l2cap_run(); 928 } 929 930 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 931 channel->remote_sig_id = identifier; 932 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 933 l2cap_run(); 934 } 935 936 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 937 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 938 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 939 signaling_responses[signaling_responses_pending].handle = handle; 940 signaling_responses[signaling_responses_pending].code = code; 941 signaling_responses[signaling_responses_pending].sig_id = sig_id; 942 signaling_responses[signaling_responses_pending].data = data; 943 signaling_responses_pending++; 944 l2cap_run(); 945 } 946 } 947 948 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 949 950 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x\n", handle, psm, source_cid); 951 l2cap_service_t *service = l2cap_get_service(psm); 952 if (!service) { 953 // 0x0002 PSM not supported 954 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 955 return; 956 } 957 958 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 959 if (!hci_connection) { 960 // 961 log_error("no hci_connection for handle %u\n", handle); 962 return; 963 } 964 965 // reject connection (0x03 security block) and disconnect if both have SSP, connection is not encrypted and PSM != SDP 966 if ( hci_ssp_supported_on_both_sides(handle) 967 && gap_security_level(handle) == LEVEL_0 968 && !l2cap_security_level_0_allowed_for_PSM(psm)){ 969 970 // 0x0003 Security Block 971 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0003); 972 return; 973 } 974 975 976 // alloc structure 977 // log_info("l2cap_handle_connection_request register channel\n"); 978 l2cap_channel_t * channel = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 979 if (!channel){ 980 // 0x0004 No resources available 981 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 982 return; 983 } 984 985 // fill in 986 BD_ADDR_COPY(channel->address, hci_connection->address); 987 channel->psm = psm; 988 channel->handle = handle; 989 channel->connection = service->connection; 990 channel->packet_handler = service->packet_handler; 991 channel->local_cid = l2cap_next_local_cid(); 992 channel->remote_cid = source_cid; 993 channel->local_mtu = service->mtu; 994 channel->remote_mtu = L2CAP_DEFAULT_MTU; 995 channel->packets_granted = 0; 996 channel->remote_sig_id = sig_id; 997 channel->required_security_level = service->required_security_level; 998 999 // limit local mtu to max acl packet length 1000 if (channel->local_mtu > l2cap_max_mtu()) { 1001 channel->local_mtu = l2cap_max_mtu(); 1002 } 1003 1004 // set initial state 1005 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1006 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 1007 1008 // add to connections list 1009 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 1010 1011 // assert security requirements 1012 gap_request_security_level(handle, channel->required_security_level); 1013 } 1014 1015 void l2cap_accept_connection_internal(uint16_t local_cid){ 1016 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1017 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1018 if (!channel) { 1019 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 1020 return; 1021 } 1022 1023 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1024 1025 // process 1026 l2cap_run(); 1027 } 1028 1029 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 1030 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); 1031 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1032 if (!channel) { 1033 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 1034 return; 1035 } 1036 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1037 channel->reason = reason; 1038 l2cap_run(); 1039 } 1040 1041 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1042 1043 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1044 1045 uint16_t flags = READ_BT_16(command, 6); 1046 if (flags & 1) { 1047 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1048 } 1049 1050 // accept the other's configuration options 1051 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1052 uint16_t pos = 8; 1053 while (pos < end_pos){ 1054 uint8_t option_hint = command[pos] >> 7; 1055 uint8_t option_type = command[pos] & 0x7f; 1056 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1057 pos++; 1058 uint8_t length = command[pos++]; 1059 // MTU { type(8): 1, len(8):2, MTU(16) } 1060 if (option_type == 1 && length == 2){ 1061 channel->remote_mtu = READ_BT_16(command, pos); 1062 // log_info("l2cap cid 0x%02x, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 1063 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1064 } 1065 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1066 if (option_type == 2 && length == 2){ 1067 channel->flush_timeout = READ_BT_16(command, pos); 1068 } 1069 // check for unknown options 1070 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1071 log_info("l2cap cid %u, unknown options", channel->local_cid); 1072 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1073 } 1074 pos += length; 1075 } 1076 } 1077 1078 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1079 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 1080 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1081 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1082 return 1; 1083 } 1084 1085 1086 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1087 1088 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1089 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1090 uint16_t result = 0; 1091 1092 log_info("L2CAP signaling handler code %u, state %u\n", code, channel->state); 1093 1094 // handle DISCONNECT REQUESTS seperately 1095 if (code == DISCONNECTION_REQUEST){ 1096 switch (channel->state){ 1097 case L2CAP_STATE_CONFIG: 1098 case L2CAP_STATE_OPEN: 1099 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1100 case L2CAP_STATE_WAIT_DISCONNECT: 1101 l2cap_handle_disconnect_request(channel, identifier); 1102 break; 1103 1104 default: 1105 // ignore in other states 1106 break; 1107 } 1108 return; 1109 } 1110 1111 // @STATEMACHINE(l2cap) 1112 switch (channel->state) { 1113 1114 case L2CAP_STATE_WAIT_CONNECT_RSP: 1115 switch (code){ 1116 case CONNECTION_RESPONSE: 1117 l2cap_stop_rtx(channel); 1118 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1119 switch (result) { 1120 case 0: 1121 // successful connection 1122 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1123 channel->state = L2CAP_STATE_CONFIG; 1124 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1125 break; 1126 case 1: 1127 // connection pending. get some coffee, but start the ERTX 1128 l2cap_start_ertx(channel); 1129 break; 1130 default: 1131 // channel closed 1132 channel->state = L2CAP_STATE_CLOSED; 1133 // map l2cap connection response result to BTstack status enumeration 1134 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1135 1136 // drop link key if security block 1137 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1138 hci_drop_link_key_for_bd_addr(&channel->address); 1139 } 1140 1141 // discard channel 1142 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1143 btstack_memory_l2cap_channel_free(channel); 1144 break; 1145 } 1146 break; 1147 1148 default: 1149 //@TODO: implement other signaling packets 1150 break; 1151 } 1152 break; 1153 1154 case L2CAP_STATE_CONFIG: 1155 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1156 switch (code) { 1157 case CONFIGURE_REQUEST: 1158 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1159 l2cap_signaling_handle_configure_request(channel, command); 1160 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1161 // only done if continuation not set 1162 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1163 } 1164 break; 1165 case CONFIGURE_RESPONSE: 1166 l2cap_stop_rtx(channel); 1167 switch (result){ 1168 case 0: // success 1169 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1170 break; 1171 case 4: // pending 1172 l2cap_start_ertx(channel); 1173 break; 1174 default: 1175 // retry on negative result 1176 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1177 break; 1178 } 1179 break; 1180 default: 1181 break; 1182 } 1183 if (l2cap_channel_ready_for_open(channel)){ 1184 // for open: 1185 channel->state = L2CAP_STATE_OPEN; 1186 l2cap_emit_channel_opened(channel, 0); 1187 l2cap_emit_credits(channel, 1); 1188 } 1189 break; 1190 1191 case L2CAP_STATE_WAIT_DISCONNECT: 1192 switch (code) { 1193 case DISCONNECTION_RESPONSE: 1194 l2cap_finialize_channel_close(channel); 1195 break; 1196 default: 1197 //@TODO: implement other signaling packets 1198 break; 1199 } 1200 break; 1201 1202 case L2CAP_STATE_CLOSED: 1203 // @TODO handle incoming requests 1204 break; 1205 1206 case L2CAP_STATE_OPEN: 1207 //@TODO: implement other signaling packets, e.g. re-configure 1208 break; 1209 default: 1210 break; 1211 } 1212 // log_info("new state %u\n", channel->state); 1213 } 1214 1215 1216 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1217 1218 // get code, signalind identifier and command len 1219 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1220 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1221 1222 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1223 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1224 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1225 return; 1226 } 1227 1228 // general commands without an assigned channel 1229 switch(code) { 1230 1231 case CONNECTION_REQUEST: { 1232 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1233 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1234 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1235 return; 1236 } 1237 1238 case ECHO_REQUEST: 1239 l2cap_register_signaling_response(handle, code, sig_id, 0); 1240 return; 1241 1242 case INFORMATION_REQUEST: { 1243 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1244 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1245 return; 1246 } 1247 1248 default: 1249 break; 1250 } 1251 1252 1253 // Get potential destination CID 1254 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1255 1256 // Find channel for this sig_id and connection handle 1257 linked_item_t *it; 1258 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1259 l2cap_channel_t * channel = (l2cap_channel_t *) it; 1260 if (channel->handle == handle) { 1261 if (code & 1) { 1262 // match odd commands (responses) by previous signaling identifier 1263 if (channel->local_sig_id == sig_id) { 1264 l2cap_signaling_handler_channel(channel, command); 1265 break; 1266 } 1267 } else { 1268 // match even commands (requests) by local channel id 1269 if (channel->local_cid == dest_cid) { 1270 l2cap_signaling_handler_channel(channel, command); 1271 break; 1272 } 1273 } 1274 } 1275 } 1276 } 1277 1278 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 1279 1280 // Get Channel ID 1281 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1282 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1283 1284 switch (channel_id) { 1285 1286 case L2CAP_CID_SIGNALING: { 1287 1288 uint16_t command_offset = 8; 1289 while (command_offset < size) { 1290 1291 // handle signaling commands 1292 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1293 1294 // increment command_offset 1295 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1296 } 1297 break; 1298 } 1299 1300 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1301 if (attribute_protocol_packet_handler) { 1302 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1303 } 1304 break; 1305 1306 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1307 if (security_protocol_packet_handler) { 1308 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1309 } 1310 break; 1311 1312 case L2CAP_CID_SIGNALING_LE: { 1313 // not implemented yet for LE Peripheral 1314 uint8_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1315 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1316 break; 1317 } 1318 1319 default: { 1320 // Find channel for this channel_id and connection handle 1321 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1322 if (channel) { 1323 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1324 } 1325 break; 1326 } 1327 } 1328 } 1329 1330 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1331 switch (packet_type) { 1332 case HCI_EVENT_PACKET: 1333 l2cap_event_handler(packet, size); 1334 break; 1335 case HCI_ACL_DATA_PACKET: 1336 l2cap_acl_handler(packet, size); 1337 break; 1338 default: 1339 break; 1340 } 1341 l2cap_run(); 1342 } 1343 1344 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1345 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1346 channel->state = L2CAP_STATE_CLOSED; 1347 l2cap_emit_channel_closed(channel); 1348 // discard channel 1349 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1350 btstack_memory_l2cap_channel_free(channel); 1351 } 1352 1353 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1354 linked_item_t *it; 1355 1356 // close open channels 1357 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 1358 l2cap_service_t * service = ((l2cap_service_t *) it); 1359 if ( service->psm == psm){ 1360 return service; 1361 }; 1362 } 1363 return NULL; 1364 } 1365 1366 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){ 1367 1368 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1369 1370 // check for alread registered psm 1371 // TODO: emit error event 1372 l2cap_service_t *service = l2cap_get_service(psm); 1373 if (service) { 1374 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 1375 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1376 return; 1377 } 1378 1379 // alloc structure 1380 // TODO: emit error event 1381 service = (l2cap_service_t *) btstack_memory_l2cap_service_get(); 1382 if (!service) { 1383 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 1384 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1385 return; 1386 } 1387 1388 // fill in 1389 service->psm = psm; 1390 service->mtu = mtu; 1391 service->connection = connection; 1392 service->packet_handler = packet_handler; 1393 service->required_security_level = security_level; 1394 1395 // add to services list 1396 linked_list_add(&l2cap_services, (linked_item_t *) service); 1397 1398 // enable page scan 1399 hci_connectable_control(1); 1400 1401 // done 1402 l2cap_emit_service_registered(connection, 0, psm); 1403 } 1404 1405 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1406 1407 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1408 1409 l2cap_service_t *service = l2cap_get_service(psm); 1410 if (!service) return; 1411 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1412 btstack_memory_l2cap_service_free(service); 1413 1414 // disable page scan when no services registered 1415 if (!linked_list_empty(&l2cap_services)) return; 1416 hci_connectable_control(0); 1417 } 1418 1419 // 1420 void l2cap_close_connection(void *connection){ 1421 linked_item_t *it; 1422 1423 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 1424 l2cap_channel_t * channel; 1425 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1426 channel = (l2cap_channel_t *) it; 1427 if (channel->connection == connection) { 1428 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1429 } 1430 } 1431 1432 // unregister services 1433 it = (linked_item_t *) &l2cap_services; 1434 while (it->next) { 1435 l2cap_service_t * service = (l2cap_service_t *) it->next; 1436 if (service->connection == connection){ 1437 it->next = it->next->next; 1438 btstack_memory_l2cap_service_free(service); 1439 } else { 1440 it = it->next; 1441 } 1442 } 1443 1444 // process 1445 l2cap_run(); 1446 } 1447 1448 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1449 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1450 switch(channel_id){ 1451 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1452 attribute_protocol_packet_handler = packet_handler; 1453 break; 1454 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1455 security_protocol_packet_handler = packet_handler; 1456 break; 1457 } 1458 } 1459 1460 #ifdef HAVE_BLE 1461 // Request LE connection parameter update 1462 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){ 1463 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 1464 log_info("l2cap_send_signaling_packet, cannot send\n"); 1465 return BTSTACK_ACL_BUFFERS_FULL; 1466 } 1467 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 1468 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1469 uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); 1470 return hci_send_acl_packet(acl_buffer, len); 1471 } 1472 #endif 1473 1474