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_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_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 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 388 389 // 0 - Connection handle : PB=pb : BC=00 390 bt_store_16(acl_buffer, 0, channel->handle | (pb << 12) | (0 << 14)); 391 // 2 - ACL length 392 bt_store_16(acl_buffer, 2, len + 4); 393 // 4 - L2CAP packet length 394 bt_store_16(acl_buffer, 4, len + 0); 395 // 6 - L2CAP channel DEST 396 bt_store_16(acl_buffer, 6, channel->remote_cid); 397 // send 398 int err = hci_send_acl_packet_buffer(len+8); 399 400 l2cap_hand_out_credits(); 401 402 return err; 403 } 404 405 int l2cap_send_prepared_connectionless(uint16_t handle, uint16_t cid, uint16_t len){ 406 407 if (!hci_is_packet_buffer_reserved()){ 408 log_error("l2cap_send_prepared_connectionless called without reserving packet first"); 409 return BTSTACK_ACL_BUFFERS_FULL; 410 } 411 412 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 413 log_info("l2cap_send_prepared_connectionless handle 0x%02x, cid 0x%02x, cannot send\n", handle, cid); 414 return BTSTACK_ACL_BUFFERS_FULL; 415 } 416 417 log_debug("l2cap_send_prepared_connectionless handle %u, cid 0x%02x\n", handle, cid); 418 419 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 420 421 int pb = hci_non_flushable_packet_boundary_flag_supported() ? 0x00 : 0x02; 422 423 // 0 - Connection handle : PB=pb : BC=00 424 bt_store_16(acl_buffer, 0, handle | (pb << 12) | (0 << 14)); 425 // 2 - ACL length 426 bt_store_16(acl_buffer, 2, len + 4); 427 // 4 - L2CAP packet length 428 bt_store_16(acl_buffer, 4, len + 0); 429 // 6 - L2CAP channel DEST 430 bt_store_16(acl_buffer, 6, cid); 431 // send 432 int err = hci_send_acl_packet_buffer(len+8); 433 434 l2cap_hand_out_credits(); 435 436 return err; 437 } 438 439 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 440 441 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 442 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", local_cid); 443 return BTSTACK_ACL_BUFFERS_FULL; 444 } 445 446 hci_reserve_packet_buffer(); 447 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 448 449 memcpy(&acl_buffer[8], data, len); 450 451 return l2cap_send_prepared(local_cid, len); 452 } 453 454 int l2cap_send_connectionless(uint16_t handle, uint16_t cid, uint8_t *data, uint16_t len){ 455 456 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 457 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", cid); 458 return BTSTACK_ACL_BUFFERS_FULL; 459 } 460 461 hci_reserve_packet_buffer(); 462 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 463 464 memcpy(&acl_buffer[8], data, len); 465 466 return l2cap_send_prepared_connectionless(handle, cid, len); 467 } 468 469 int l2cap_send_echo_request(uint16_t handle, uint8_t *data, uint16_t len){ 470 return l2cap_send_signaling_packet(handle, ECHO_REQUEST, 0x77, len, data); 471 } 472 473 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 474 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 475 } 476 477 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 478 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 479 } 480 481 482 483 // MARK: L2CAP_RUN 484 // process outstanding signaling tasks 485 void l2cap_run(void){ 486 487 // check pending signaling responses 488 while (signaling_responses_pending){ 489 490 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)) break; 491 492 hci_con_handle_t handle = signaling_responses[0].handle; 493 uint8_t sig_id = signaling_responses[0].sig_id; 494 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 495 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 496 497 switch (signaling_responses[0].code){ 498 case CONNECTION_REQUEST: 499 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 500 // also disconnect if result is 0x0003 - security blocked 501 hci_disconnect_security_block(handle); 502 break; 503 case ECHO_REQUEST: 504 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 505 break; 506 case INFORMATION_REQUEST: 507 switch (infoType){ 508 case 1: { // Connectionless MTU 509 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 510 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 511 break; 512 } 513 case 2: { // Extended Features Supported 514 // extended features request supported, only supporing fixed channel map 515 uint32_t features = 0x80; 516 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 517 break; 518 } 519 case 3: { // Fixed Channels Supported 520 uint8_t map[8]; 521 memset(map, 0, 8); 522 map[0] = 0x01; // L2CAP Signaling Channel 523 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 524 break; 525 } 526 default: 527 // all other types are not supported 528 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 529 break; 530 } 531 break; 532 case COMMAND_REJECT: 533 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 534 #ifdef HAVE_BLE 535 case COMMAND_REJECT_LE: 536 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 537 break; 538 #endif 539 default: 540 // should not happen 541 break; 542 } 543 544 // remove first item 545 signaling_responses_pending--; 546 int i; 547 for (i=0; i < signaling_responses_pending; i++){ 548 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 549 } 550 } 551 552 uint8_t config_options[4]; 553 linked_item_t *it; 554 linked_item_t *next; 555 for (it = (linked_item_t *) l2cap_channels; it ; it = next){ 556 next = it->next; // cache next item as current item might get freed 557 558 if (!hci_can_send_packet_now_using_packet_buffer(HCI_COMMAND_DATA_PACKET)) break; 559 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)) break; 560 561 l2cap_channel_t * channel = (l2cap_channel_t *) it; 562 563 // log_info("l2cap_run: state %u, var 0x%02x\n", channel->state, channel->state_var); 564 565 566 switch (channel->state){ 567 568 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 569 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 570 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 571 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 572 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 573 } 574 break; 575 576 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 577 // send connection request - set state first 578 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 579 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 580 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 581 break; 582 583 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 584 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 585 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 586 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); // -- remove from list 587 btstack_memory_l2cap_channel_free(channel); 588 break; 589 590 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 591 channel->state = L2CAP_STATE_CONFIG; 592 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 593 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 594 break; 595 596 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 597 // success, start l2cap handshake 598 channel->local_sig_id = l2cap_next_sig_id(); 599 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 600 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 601 l2cap_start_rtx(channel); 602 break; 603 604 case L2CAP_STATE_CONFIG: 605 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 606 uint16_t flags = 0; 607 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 608 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 609 flags = 1; 610 } else { 611 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 612 } 613 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 614 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 615 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 616 config_options[0] = 1; // MTU 617 config_options[1] = 2; // len param 618 bt_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 619 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 620 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 621 } else { 622 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 623 } 624 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 625 } 626 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 627 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 628 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 629 channel->local_sig_id = l2cap_next_sig_id(); 630 config_options[0] = 1; // MTU 631 config_options[1] = 2; // len param 632 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 633 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 634 l2cap_start_rtx(channel); 635 } 636 if (l2cap_channel_ready_for_open(channel)){ 637 channel->state = L2CAP_STATE_OPEN; 638 l2cap_emit_channel_opened(channel, 0); // success 639 l2cap_emit_credits(channel, 1); 640 } 641 break; 642 643 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 644 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 645 // 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 :) 646 l2cap_finialize_channel_close(channel); // -- remove from list 647 break; 648 649 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 650 channel->local_sig_id = l2cap_next_sig_id(); 651 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 652 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 653 break; 654 default: 655 break; 656 } 657 } 658 } 659 660 uint16_t l2cap_max_mtu(void){ 661 return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE; 662 } 663 664 static void l2cap_handle_connection_complete(uint16_t handle, l2cap_channel_t * channel){ 665 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 666 log_info("l2cap_handle_connection_complete expected state"); 667 // success, start l2cap handshake 668 channel->handle = handle; 669 channel->local_cid = l2cap_next_local_cid(); 670 // check remote SSP feature first 671 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 672 } 673 } 674 675 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 676 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 677 678 // we have been waiting for remote supported features, if both support SSP, 679 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)); 680 if (hci_ssp_supported_on_both_sides(channel->handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 681 // request security level 2 682 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 683 gap_request_security_level(channel->handle, LEVEL_2); 684 return; 685 } 686 // fine, go ahead 687 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 688 } 689 690 // open outgoing L2CAP channel 691 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 692 bd_addr_t address, uint16_t psm, uint16_t mtu){ 693 694 log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 695 696 // alloc structure 697 l2cap_channel_t * chan = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 698 if (!chan) { 699 // emit error event 700 l2cap_channel_t dummy_channel; 701 BD_ADDR_COPY(dummy_channel.address, address); 702 dummy_channel.psm = psm; 703 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 704 return; 705 } 706 // limit local mtu to max acl packet length 707 if (mtu > l2cap_max_mtu()) { 708 mtu = l2cap_max_mtu(); 709 } 710 711 // fill in 712 BD_ADDR_COPY(chan->address, address); 713 chan->psm = psm; 714 chan->handle = 0; 715 chan->connection = connection; 716 chan->packet_handler = packet_handler; 717 chan->remote_mtu = L2CAP_MINIMAL_MTU; 718 chan->local_mtu = mtu; 719 chan->packets_granted = 0; 720 721 // set initial state 722 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 723 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 724 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 725 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 726 chan->required_security_level = LEVEL_0; 727 728 // add to connections list 729 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 730 731 // check if hci connection is already usable 732 hci_connection_t * conn = hci_connection_for_bd_addr_and_type((bd_addr_t*)address, BD_ADDR_TYPE_CLASSIC); 733 if (conn){ 734 log_info("l2cap_create_channel_internal, hci connection already exists"); 735 l2cap_handle_connection_complete(conn->con_handle, chan); 736 // check ir remote supported fearures are already received 737 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 738 l2cap_handle_remote_supported_features_received(chan); 739 } 740 } 741 742 l2cap_run(); 743 } 744 745 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 746 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 747 // find channel for local_cid 748 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 749 if (channel) { 750 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 751 } 752 // process 753 l2cap_run(); 754 } 755 756 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 757 linked_item_t *it = (linked_item_t *) &l2cap_channels; 758 while (it->next){ 759 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 760 if ( ! BD_ADDR_CMP( channel->address, address) ){ 761 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 762 // failure, forward error code 763 l2cap_emit_channel_opened(channel, status); 764 // discard channel 765 it->next = it->next->next; 766 btstack_memory_l2cap_channel_free(channel); 767 } 768 } else { 769 it = it->next; 770 } 771 } 772 } 773 774 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 775 linked_item_t *it; 776 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 777 l2cap_channel_t * channel = (l2cap_channel_t *) it; 778 if ( ! BD_ADDR_CMP( channel->address, address) ){ 779 l2cap_handle_connection_complete(handle, channel); 780 } 781 } 782 // process 783 l2cap_run(); 784 } 785 786 void l2cap_event_handler(uint8_t *packet, uint16_t size){ 787 788 bd_addr_t address; 789 hci_con_handle_t handle; 790 l2cap_channel_t * channel; 791 linked_item_t *it; 792 int hci_con_used; 793 794 switch(packet[0]){ 795 796 // handle connection complete events 797 case HCI_EVENT_CONNECTION_COMPLETE: 798 bt_flip_addr(address, &packet[5]); 799 if (packet[2] == 0){ 800 handle = READ_BT_16(packet, 3); 801 l2cap_handle_connection_success_for_addr(address, handle); 802 } else { 803 l2cap_handle_connection_failed_for_addr(address, packet[2]); 804 } 805 break; 806 807 // handle successful create connection cancel command 808 case HCI_EVENT_COMMAND_COMPLETE: 809 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 810 if (packet[5] == 0){ 811 bt_flip_addr(address, &packet[6]); 812 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 813 l2cap_handle_connection_failed_for_addr(address, 0x16); 814 } 815 } 816 l2cap_run(); // try sending signaling packets first 817 break; 818 819 case HCI_EVENT_COMMAND_STATUS: 820 l2cap_run(); // try sending signaling packets first 821 break; 822 823 // handle disconnection complete events 824 case HCI_EVENT_DISCONNECTION_COMPLETE: 825 // send l2cap disconnect events for all channels on this handle 826 handle = READ_BT_16(packet, 3); 827 it = (linked_item_t *) &l2cap_channels; 828 while (it->next){ 829 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 830 if ( channel->handle == handle ){ 831 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 832 it->next = it->next->next; 833 l2cap_emit_channel_closed(channel); 834 btstack_memory_l2cap_channel_free(channel); 835 } else { 836 it = it->next; 837 } 838 } 839 break; 840 841 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 842 l2cap_run(); // try sending signaling packets first 843 l2cap_hand_out_credits(); 844 break; 845 846 // HCI Connection Timeouts 847 case L2CAP_EVENT_TIMEOUT_CHECK: 848 handle = READ_BT_16(packet, 2); 849 if (hci_authentication_active_for_handle(handle)) break; 850 hci_con_used = 0; 851 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 852 channel = (l2cap_channel_t *) it; 853 if (channel->handle == handle) { 854 hci_con_used = 1; 855 } 856 } 857 if (hci_con_used) break; 858 if (!hci_can_send_packet_now_using_packet_buffer(HCI_COMMAND_DATA_PACKET)) break; 859 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 860 break; 861 862 case DAEMON_EVENT_HCI_PACKET_SENT: 863 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 864 channel = (l2cap_channel_t *) it; 865 if (channel->packet_handler) { 866 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 867 } 868 } 869 if (attribute_protocol_packet_handler) { 870 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 871 } 872 if (security_protocol_packet_handler) { 873 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 874 } 875 break; 876 877 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 878 handle = READ_BT_16(packet, 3); 879 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 880 channel = (l2cap_channel_t *) it; 881 if (channel->handle != handle) continue; 882 l2cap_handle_remote_supported_features_received(channel); 883 break; 884 } 885 886 case GAP_SECURITY_LEVEL: 887 handle = READ_BT_16(packet, 2); 888 log_info("l2cap - security level update"); 889 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 890 channel = (l2cap_channel_t *) it; 891 if (channel->handle != handle) continue; 892 893 log_info("l2cap - state %u", channel->state); 894 895 gap_security_level_t actual_level = packet[4]; 896 gap_security_level_t required_level = channel->required_security_level; 897 898 switch (channel->state){ 899 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 900 if (actual_level >= required_level){ 901 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 902 l2cap_emit_connection_request(channel); 903 } else { 904 channel->reason = 0x03; // security block 905 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 906 } 907 break; 908 909 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 910 if (actual_level >= required_level){ 911 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 912 } else { 913 // disconnnect, authentication not good enough 914 hci_disconnect_security_block(handle); 915 } 916 break; 917 918 default: 919 break; 920 } 921 } 922 break; 923 924 default: 925 break; 926 } 927 928 // pass on: main packet handler, att and sm packet handlers 929 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 930 if (attribute_protocol_packet_handler){ 931 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 932 } 933 if (security_protocol_packet_handler) { 934 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 935 } 936 937 l2cap_run(); 938 } 939 940 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 941 channel->remote_sig_id = identifier; 942 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 943 l2cap_run(); 944 } 945 946 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 947 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 948 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 949 signaling_responses[signaling_responses_pending].handle = handle; 950 signaling_responses[signaling_responses_pending].code = code; 951 signaling_responses[signaling_responses_pending].sig_id = sig_id; 952 signaling_responses[signaling_responses_pending].data = data; 953 signaling_responses_pending++; 954 l2cap_run(); 955 } 956 } 957 958 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 959 960 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x\n", handle, psm, source_cid); 961 l2cap_service_t *service = l2cap_get_service(psm); 962 if (!service) { 963 // 0x0002 PSM not supported 964 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 965 return; 966 } 967 968 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 969 if (!hci_connection) { 970 // 971 log_error("no hci_connection for handle %u\n", handle); 972 return; 973 } 974 975 // reject connection (0x03 security block) and disconnect if both have SSP, connection is not encrypted and PSM != SDP 976 if ( hci_ssp_supported_on_both_sides(handle) 977 && gap_security_level(handle) == LEVEL_0 978 && !l2cap_security_level_0_allowed_for_PSM(psm)){ 979 980 // 0x0003 Security Block 981 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0003); 982 return; 983 } 984 985 986 // alloc structure 987 // log_info("l2cap_handle_connection_request register channel\n"); 988 l2cap_channel_t * channel = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 989 if (!channel){ 990 // 0x0004 No resources available 991 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 992 return; 993 } 994 995 // fill in 996 BD_ADDR_COPY(channel->address, hci_connection->address); 997 channel->psm = psm; 998 channel->handle = handle; 999 channel->connection = service->connection; 1000 channel->packet_handler = service->packet_handler; 1001 channel->local_cid = l2cap_next_local_cid(); 1002 channel->remote_cid = source_cid; 1003 channel->local_mtu = service->mtu; 1004 channel->remote_mtu = L2CAP_DEFAULT_MTU; 1005 channel->packets_granted = 0; 1006 channel->remote_sig_id = sig_id; 1007 channel->required_security_level = service->required_security_level; 1008 1009 // limit local mtu to max acl packet length 1010 if (channel->local_mtu > l2cap_max_mtu()) { 1011 channel->local_mtu = l2cap_max_mtu(); 1012 } 1013 1014 // set initial state 1015 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 1016 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 1017 1018 // add to connections list 1019 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 1020 1021 // assert security requirements 1022 gap_request_security_level(handle, channel->required_security_level); 1023 } 1024 1025 void l2cap_accept_connection_internal(uint16_t local_cid){ 1026 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 1027 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 1028 if (!channel) { 1029 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 1030 return; 1031 } 1032 1033 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1034 1035 // process 1036 l2cap_run(); 1037 } 1038 1039 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 1040 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); 1041 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1042 if (!channel) { 1043 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 1044 return; 1045 } 1046 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1047 channel->reason = reason; 1048 l2cap_run(); 1049 } 1050 1051 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1052 1053 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1054 1055 uint16_t flags = READ_BT_16(command, 6); 1056 if (flags & 1) { 1057 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1058 } 1059 1060 // accept the other's configuration options 1061 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1062 uint16_t pos = 8; 1063 while (pos < end_pos){ 1064 uint8_t option_hint = command[pos] >> 7; 1065 uint8_t option_type = command[pos] & 0x7f; 1066 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1067 pos++; 1068 uint8_t length = command[pos++]; 1069 // MTU { type(8): 1, len(8):2, MTU(16) } 1070 if (option_type == 1 && length == 2){ 1071 channel->remote_mtu = READ_BT_16(command, pos); 1072 // log_info("l2cap cid 0x%02x, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 1073 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1074 } 1075 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1076 if (option_type == 2 && length == 2){ 1077 channel->flush_timeout = READ_BT_16(command, pos); 1078 } 1079 // check for unknown options 1080 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1081 log_info("l2cap cid %u, unknown options", channel->local_cid); 1082 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1083 } 1084 pos += length; 1085 } 1086 } 1087 1088 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1089 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 1090 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1091 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1092 return 1; 1093 } 1094 1095 1096 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1097 1098 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1099 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1100 uint16_t result = 0; 1101 1102 log_info("L2CAP signaling handler code %u, state %u\n", code, channel->state); 1103 1104 // handle DISCONNECT REQUESTS seperately 1105 if (code == DISCONNECTION_REQUEST){ 1106 switch (channel->state){ 1107 case L2CAP_STATE_CONFIG: 1108 case L2CAP_STATE_OPEN: 1109 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1110 case L2CAP_STATE_WAIT_DISCONNECT: 1111 l2cap_handle_disconnect_request(channel, identifier); 1112 break; 1113 1114 default: 1115 // ignore in other states 1116 break; 1117 } 1118 return; 1119 } 1120 1121 // @STATEMACHINE(l2cap) 1122 switch (channel->state) { 1123 1124 case L2CAP_STATE_WAIT_CONNECT_RSP: 1125 switch (code){ 1126 case CONNECTION_RESPONSE: 1127 l2cap_stop_rtx(channel); 1128 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1129 switch (result) { 1130 case 0: 1131 // successful connection 1132 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1133 channel->state = L2CAP_STATE_CONFIG; 1134 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1135 break; 1136 case 1: 1137 // connection pending. get some coffee, but start the ERTX 1138 l2cap_start_ertx(channel); 1139 break; 1140 default: 1141 // channel closed 1142 channel->state = L2CAP_STATE_CLOSED; 1143 // map l2cap connection response result to BTstack status enumeration 1144 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1145 1146 // drop link key if security block 1147 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1148 hci_drop_link_key_for_bd_addr(&channel->address); 1149 } 1150 1151 // discard channel 1152 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1153 btstack_memory_l2cap_channel_free(channel); 1154 break; 1155 } 1156 break; 1157 1158 default: 1159 //@TODO: implement other signaling packets 1160 break; 1161 } 1162 break; 1163 1164 case L2CAP_STATE_CONFIG: 1165 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1166 switch (code) { 1167 case CONFIGURE_REQUEST: 1168 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1169 l2cap_signaling_handle_configure_request(channel, command); 1170 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1171 // only done if continuation not set 1172 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1173 } 1174 break; 1175 case CONFIGURE_RESPONSE: 1176 l2cap_stop_rtx(channel); 1177 switch (result){ 1178 case 0: // success 1179 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1180 break; 1181 case 4: // pending 1182 l2cap_start_ertx(channel); 1183 break; 1184 default: 1185 // retry on negative result 1186 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1187 break; 1188 } 1189 break; 1190 default: 1191 break; 1192 } 1193 if (l2cap_channel_ready_for_open(channel)){ 1194 // for open: 1195 channel->state = L2CAP_STATE_OPEN; 1196 l2cap_emit_channel_opened(channel, 0); 1197 l2cap_emit_credits(channel, 1); 1198 } 1199 break; 1200 1201 case L2CAP_STATE_WAIT_DISCONNECT: 1202 switch (code) { 1203 case DISCONNECTION_RESPONSE: 1204 l2cap_finialize_channel_close(channel); 1205 break; 1206 default: 1207 //@TODO: implement other signaling packets 1208 break; 1209 } 1210 break; 1211 1212 case L2CAP_STATE_CLOSED: 1213 // @TODO handle incoming requests 1214 break; 1215 1216 case L2CAP_STATE_OPEN: 1217 //@TODO: implement other signaling packets, e.g. re-configure 1218 break; 1219 default: 1220 break; 1221 } 1222 // log_info("new state %u\n", channel->state); 1223 } 1224 1225 1226 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1227 1228 // get code, signalind identifier and command len 1229 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1230 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1231 1232 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1233 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1234 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1235 return; 1236 } 1237 1238 // general commands without an assigned channel 1239 switch(code) { 1240 1241 case CONNECTION_REQUEST: { 1242 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1243 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1244 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1245 return; 1246 } 1247 1248 case ECHO_REQUEST: 1249 l2cap_register_signaling_response(handle, code, sig_id, 0); 1250 return; 1251 1252 case INFORMATION_REQUEST: { 1253 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1254 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1255 return; 1256 } 1257 1258 default: 1259 break; 1260 } 1261 1262 1263 // Get potential destination CID 1264 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1265 1266 // Find channel for this sig_id and connection handle 1267 linked_item_t *it; 1268 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1269 l2cap_channel_t * channel = (l2cap_channel_t *) it; 1270 if (channel->handle == handle) { 1271 if (code & 1) { 1272 // match odd commands (responses) by previous signaling identifier 1273 if (channel->local_sig_id == sig_id) { 1274 l2cap_signaling_handler_channel(channel, command); 1275 break; 1276 } 1277 } else { 1278 // match even commands (requests) by local channel id 1279 if (channel->local_cid == dest_cid) { 1280 l2cap_signaling_handler_channel(channel, command); 1281 break; 1282 } 1283 } 1284 } 1285 } 1286 } 1287 1288 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 1289 1290 // Get Channel ID 1291 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1292 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1293 1294 switch (channel_id) { 1295 1296 case L2CAP_CID_SIGNALING: { 1297 1298 uint16_t command_offset = 8; 1299 while (command_offset < size) { 1300 1301 // handle signaling commands 1302 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1303 1304 // increment command_offset 1305 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1306 } 1307 break; 1308 } 1309 1310 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1311 if (attribute_protocol_packet_handler) { 1312 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1313 } 1314 break; 1315 1316 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1317 if (security_protocol_packet_handler) { 1318 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1319 } 1320 break; 1321 1322 case L2CAP_CID_SIGNALING_LE: { 1323 // not implemented yet for LE Peripheral 1324 uint8_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1325 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1326 break; 1327 } 1328 1329 default: { 1330 // Find channel for this channel_id and connection handle 1331 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1332 if (channel) { 1333 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1334 } 1335 break; 1336 } 1337 } 1338 } 1339 1340 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1341 switch (packet_type) { 1342 case HCI_EVENT_PACKET: 1343 l2cap_event_handler(packet, size); 1344 break; 1345 case HCI_ACL_DATA_PACKET: 1346 l2cap_acl_handler(packet, size); 1347 break; 1348 default: 1349 break; 1350 } 1351 l2cap_run(); 1352 } 1353 1354 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1355 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1356 channel->state = L2CAP_STATE_CLOSED; 1357 l2cap_emit_channel_closed(channel); 1358 // discard channel 1359 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1360 btstack_memory_l2cap_channel_free(channel); 1361 } 1362 1363 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1364 linked_item_t *it; 1365 1366 // close open channels 1367 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 1368 l2cap_service_t * service = ((l2cap_service_t *) it); 1369 if ( service->psm == psm){ 1370 return service; 1371 }; 1372 } 1373 return NULL; 1374 } 1375 1376 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){ 1377 1378 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1379 1380 // check for alread registered psm 1381 // TODO: emit error event 1382 l2cap_service_t *service = l2cap_get_service(psm); 1383 if (service) { 1384 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 1385 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1386 return; 1387 } 1388 1389 // alloc structure 1390 // TODO: emit error event 1391 service = (l2cap_service_t *) btstack_memory_l2cap_service_get(); 1392 if (!service) { 1393 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 1394 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1395 return; 1396 } 1397 1398 // fill in 1399 service->psm = psm; 1400 service->mtu = mtu; 1401 service->connection = connection; 1402 service->packet_handler = packet_handler; 1403 service->required_security_level = security_level; 1404 1405 // add to services list 1406 linked_list_add(&l2cap_services, (linked_item_t *) service); 1407 1408 // enable page scan 1409 hci_connectable_control(1); 1410 1411 // done 1412 l2cap_emit_service_registered(connection, 0, psm); 1413 } 1414 1415 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1416 1417 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1418 1419 l2cap_service_t *service = l2cap_get_service(psm); 1420 if (!service) return; 1421 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1422 btstack_memory_l2cap_service_free(service); 1423 1424 // disable page scan when no services registered 1425 if (!linked_list_empty(&l2cap_services)) return; 1426 hci_connectable_control(0); 1427 } 1428 1429 // 1430 void l2cap_close_connection(void *connection){ 1431 linked_item_t *it; 1432 1433 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 1434 l2cap_channel_t * channel; 1435 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1436 channel = (l2cap_channel_t *) it; 1437 if (channel->connection == connection) { 1438 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1439 } 1440 } 1441 1442 // unregister services 1443 it = (linked_item_t *) &l2cap_services; 1444 while (it->next) { 1445 l2cap_service_t * service = (l2cap_service_t *) it->next; 1446 if (service->connection == connection){ 1447 it->next = it->next->next; 1448 btstack_memory_l2cap_service_free(service); 1449 } else { 1450 it = it->next; 1451 } 1452 } 1453 1454 // process 1455 l2cap_run(); 1456 } 1457 1458 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1459 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1460 switch(channel_id){ 1461 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1462 attribute_protocol_packet_handler = packet_handler; 1463 break; 1464 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1465 security_protocol_packet_handler = packet_handler; 1466 break; 1467 } 1468 } 1469 1470 #ifdef HAVE_BLE 1471 // Request LE connection parameter update 1472 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){ 1473 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 1474 log_info("l2cap_send_signaling_packet, cannot send\n"); 1475 return BTSTACK_ACL_BUFFERS_FULL; 1476 } 1477 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 1478 hci_reserve_packet_buffer(); 1479 uint8_t *acl_buffer = hci_get_outgoing_packet_buffer(); 1480 uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); 1481 return hci_send_acl_packet_buffer(len); 1482 } 1483 #endif 1484 1485