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(HCI_ACL_DATA_PACKET); 236 } 237 238 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 239 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 240 if (channel) { 241 return channel->remote_mtu; 242 } 243 return 0; 244 } 245 246 static l2cap_channel_t * l2cap_channel_for_rtx_timer(timer_source_t * ts){ 247 linked_item_t *it; 248 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 249 l2cap_channel_t * channel = (l2cap_channel_t *) it; 250 if ( &channel->rtx == ts) { 251 return channel; 252 } 253 } 254 return NULL; 255 } 256 257 static void l2cap_rtx_timeout(timer_source_t * ts){ 258 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 259 if (!ts) return; 260 261 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 262 263 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 264 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 265 // notify client 266 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 267 268 // discard channel 269 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 270 btstack_memory_l2cap_channel_free(channel); 271 } 272 273 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 274 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 275 run_loop_remove_timer(&channel->rtx); 276 } 277 278 static void l2cap_start_rtx(l2cap_channel_t * channel){ 279 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 280 l2cap_stop_rtx(channel); 281 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 282 run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 283 run_loop_add_timer(&channel->rtx); 284 } 285 286 static void l2cap_start_ertx(l2cap_channel_t * channel){ 287 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 288 l2cap_stop_rtx(channel); 289 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 290 run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 291 run_loop_add_timer(&channel->rtx); 292 } 293 294 void l2cap_require_security_level_2_for_outgoing_sdp(){ 295 require_security_level2_for_outgoing_sdp = 1; 296 } 297 298 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 299 return (psm == PSM_SDP) && (!require_security_level2_for_outgoing_sdp); 300 } 301 302 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 303 304 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 305 log_info("l2cap_send_signaling_packet, cannot send\n"); 306 return BTSTACK_ACL_BUFFERS_FULL; 307 } 308 309 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 310 hci_reserve_packet_buffer(); 311 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 312 va_list argptr; 313 va_start(argptr, identifier); 314 uint16_t len = l2cap_create_signaling_classic(acl_buffer, handle, cmd, identifier, argptr); 315 va_end(argptr); 316 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 317 return hci_send_acl_packet(acl_buffer, len); 318 } 319 320 #ifdef HAVE_BLE 321 int l2cap_send_le_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 322 323 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 324 log_info("l2cap_send_signaling_packet, cannot send\n"); 325 return BTSTACK_ACL_BUFFERS_FULL; 326 } 327 328 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 329 hci_reserve_packet_buffer(); 330 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 331 va_list argptr; 332 va_start(argptr, identifier); 333 uint16_t len = l2cap_create_signaling_le(acl_buffer, handle, cmd, identifier, argptr); 334 va_end(argptr); 335 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 336 return hci_send_acl_packet(acl_buffer, len); 337 } 338 #endif 339 340 uint8_t *l2cap_get_outgoing_buffer(void){ 341 return hci_get_outgoing_acl_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 342 } 343 344 int l2cap_reserve_packet_buffer(void){ 345 return hci_reserve_packet_buffer(); 346 } 347 348 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 349 350 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 351 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", local_cid); 352 return BTSTACK_ACL_BUFFERS_FULL; 353 } 354 355 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 356 if (!channel) { 357 log_error("l2cap_send_internal no channel for cid 0x%02x\n", local_cid); 358 return -1; // TODO: define error 359 } 360 361 if (channel->packets_granted == 0){ 362 log_error("l2cap_send_internal cid 0x%02x, no credits!\n", local_cid); 363 return -1; // TODO: define error 364 } 365 366 --channel->packets_granted; 367 368 log_debug("l2cap_send_internal cid 0x%02x, handle %u, 1 credit used, credits left %u;\n", 369 local_cid, channel->handle, channel->packets_granted); 370 371 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 372 373 // 0 - Connection handle : PB=10 : BC=00 374 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 375 // 2 - ACL length 376 bt_store_16(acl_buffer, 2, len + 4); 377 // 4 - L2CAP packet length 378 bt_store_16(acl_buffer, 4, len + 0); 379 // 6 - L2CAP channel DEST 380 bt_store_16(acl_buffer, 6, channel->remote_cid); 381 // send 382 int err = hci_send_acl_packet(acl_buffer, len+8); 383 384 l2cap_hand_out_credits(); 385 386 return err; 387 } 388 389 int l2cap_send_prepared_connectionless(uint16_t handle, uint16_t cid, uint16_t len){ 390 391 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 392 log_info("l2cap_send_prepared_to_handle cid 0x%02x, cannot send\n", cid); 393 return BTSTACK_ACL_BUFFERS_FULL; 394 } 395 396 log_debug("l2cap_send_prepared_to_handle cid 0x%02x, handle %u\n", cid, handle); 397 398 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 399 400 // 0 - Connection handle : PB=10 : BC=00 401 bt_store_16(acl_buffer, 0, handle | (2 << 12) | (0 << 14)); 402 // 2 - ACL length 403 bt_store_16(acl_buffer, 2, len + 4); 404 // 4 - L2CAP packet length 405 bt_store_16(acl_buffer, 4, len + 0); 406 // 6 - L2CAP channel DEST 407 bt_store_16(acl_buffer, 6, cid); 408 // send 409 int err = hci_send_acl_packet(acl_buffer, len+8); 410 411 l2cap_hand_out_credits(); 412 413 return err; 414 } 415 416 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 417 418 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 419 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", local_cid); 420 return BTSTACK_ACL_BUFFERS_FULL; 421 } 422 423 hci_reserve_packet_buffer(); 424 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 425 426 memcpy(&acl_buffer[8], data, len); 427 428 return l2cap_send_prepared(local_cid, len); 429 } 430 431 int l2cap_send_connectionless(uint16_t handle, uint16_t cid, uint8_t *data, uint16_t len){ 432 433 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 434 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", cid); 435 return BTSTACK_ACL_BUFFERS_FULL; 436 } 437 438 hci_reserve_packet_buffer(); 439 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 440 441 memcpy(&acl_buffer[8], data, len); 442 443 return l2cap_send_prepared_connectionless(handle, cid, len); 444 } 445 446 int l2cap_send_echo_request(uint16_t handle, uint8_t *data, uint16_t len){ 447 return l2cap_send_signaling_packet(handle, ECHO_REQUEST, 0x77, len, data); 448 } 449 450 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 451 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 452 } 453 454 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 455 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 456 } 457 458 459 460 // MARK: L2CAP_RUN 461 // process outstanding signaling tasks 462 void l2cap_run(void){ 463 464 // check pending signaling responses 465 while (signaling_responses_pending){ 466 467 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)) break; 468 469 hci_con_handle_t handle = signaling_responses[0].handle; 470 uint8_t sig_id = signaling_responses[0].sig_id; 471 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 472 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 473 474 switch (signaling_responses[0].code){ 475 case CONNECTION_REQUEST: 476 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 477 // also disconnect if result is 0x0003 - security blocked 478 hci_disconnect_security_block(handle); 479 break; 480 case ECHO_REQUEST: 481 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 482 break; 483 case INFORMATION_REQUEST: 484 switch (infoType){ 485 case 1: { // Connectionless MTU 486 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 487 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 488 break; 489 } 490 case 2: { // Extended Features Supported 491 // extended features request supported, only supporing fixed channel map 492 uint32_t features = 0x80; 493 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 494 break; 495 } 496 case 3: { // Fixed Channels Supported 497 uint8_t map[8]; 498 memset(map, 0, 8); 499 map[0] = 0x01; // L2CAP Signaling Channel 500 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 501 break; 502 } 503 default: 504 // all other types are not supported 505 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 506 break; 507 } 508 break; 509 case COMMAND_REJECT: 510 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 511 #ifdef HAVE_BLE 512 case COMMAND_REJECT_LE: 513 l2cap_send_le_signaling_packet(handle, COMMAND_REJECT, sig_id, result, 0, NULL); 514 break; 515 #endif 516 default: 517 // should not happen 518 break; 519 } 520 521 // remove first item 522 signaling_responses_pending--; 523 int i; 524 for (i=0; i < signaling_responses_pending; i++){ 525 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 526 } 527 } 528 529 uint8_t config_options[4]; 530 linked_item_t *it; 531 linked_item_t *next; 532 for (it = (linked_item_t *) l2cap_channels; it ; it = next){ 533 next = it->next; // cache next item as current item might get freed 534 535 if (!hci_can_send_packet_now_using_packet_buffer(HCI_COMMAND_DATA_PACKET)) break; 536 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)) break; 537 538 l2cap_channel_t * channel = (l2cap_channel_t *) it; 539 540 // log_info("l2cap_run: state %u, var 0x%02x\n", channel->state, channel->state_var); 541 542 543 switch (channel->state){ 544 545 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 546 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 547 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 548 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 549 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 550 } 551 break; 552 553 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 554 // send connection request - set state first 555 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 556 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 557 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 558 break; 559 560 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 561 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 562 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 563 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); // -- remove from list 564 btstack_memory_l2cap_channel_free(channel); 565 break; 566 567 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 568 channel->state = L2CAP_STATE_CONFIG; 569 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 570 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 571 break; 572 573 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 574 // success, start l2cap handshake 575 channel->local_sig_id = l2cap_next_sig_id(); 576 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 577 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 578 l2cap_start_rtx(channel); 579 break; 580 581 case L2CAP_STATE_CONFIG: 582 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 583 uint16_t flags = 0; 584 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 585 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 586 flags = 1; 587 } else { 588 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 589 } 590 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 591 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 592 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 593 config_options[0] = 1; // MTU 594 config_options[1] = 2; // len param 595 bt_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 596 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 597 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 598 } else { 599 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 600 } 601 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 602 } 603 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 604 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 605 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 606 channel->local_sig_id = l2cap_next_sig_id(); 607 config_options[0] = 1; // MTU 608 config_options[1] = 2; // len param 609 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 610 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 611 l2cap_start_rtx(channel); 612 } 613 if (l2cap_channel_ready_for_open(channel)){ 614 channel->state = L2CAP_STATE_OPEN; 615 l2cap_emit_channel_opened(channel, 0); // success 616 l2cap_emit_credits(channel, 1); 617 } 618 break; 619 620 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 621 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 622 // 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 :) 623 l2cap_finialize_channel_close(channel); // -- remove from list 624 break; 625 626 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 627 channel->local_sig_id = l2cap_next_sig_id(); 628 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 629 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 630 break; 631 default: 632 break; 633 } 634 } 635 } 636 637 uint16_t l2cap_max_mtu(void){ 638 return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE; 639 } 640 641 static void l2cap_handle_connection_complete(uint16_t handle, l2cap_channel_t * channel){ 642 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 643 log_info("l2cap_handle_connection_complete expected state"); 644 // success, start l2cap handshake 645 channel->handle = handle; 646 channel->local_cid = l2cap_next_local_cid(); 647 // check remote SSP feature first 648 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 649 } 650 } 651 652 static void l2cap_handle_remote_supported_features_received(l2cap_channel_t * channel){ 653 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) return; 654 655 // we have been waiting for remote supported features, if both support SSP, 656 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)); 657 if (hci_ssp_supported_on_both_sides(channel->handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 658 // request security level 2 659 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 660 gap_request_security_level(channel->handle, LEVEL_2); 661 return; 662 } 663 // fine, go ahead 664 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 665 } 666 667 // open outgoing L2CAP channel 668 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 669 bd_addr_t address, uint16_t psm, uint16_t mtu){ 670 671 log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 672 673 // alloc structure 674 l2cap_channel_t * chan = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 675 if (!chan) { 676 // emit error event 677 l2cap_channel_t dummy_channel; 678 BD_ADDR_COPY(dummy_channel.address, address); 679 dummy_channel.psm = psm; 680 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 681 return; 682 } 683 // limit local mtu to max acl packet length 684 if (mtu > l2cap_max_mtu()) { 685 mtu = l2cap_max_mtu(); 686 } 687 688 // fill in 689 BD_ADDR_COPY(chan->address, address); 690 chan->psm = psm; 691 chan->handle = 0; 692 chan->connection = connection; 693 chan->packet_handler = packet_handler; 694 chan->remote_mtu = L2CAP_MINIMAL_MTU; 695 chan->local_mtu = mtu; 696 chan->packets_granted = 0; 697 698 // set initial state 699 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 700 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 701 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 702 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 703 chan->required_security_level = LEVEL_0; 704 705 // add to connections list 706 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 707 708 // check if hci connection is already usable 709 hci_connection_t * conn = hci_connection_for_bd_addr((bd_addr_t*)address); 710 if (conn){ 711 log_info("l2cap_create_channel_internal, hci connection already exists"); 712 l2cap_handle_connection_complete(conn->con_handle, chan); 713 // check ir remote supported fearures are already received 714 if (conn->bonding_flags & BONDING_RECEIVED_REMOTE_FEATURES) { 715 l2cap_handle_remote_supported_features_received(chan); 716 } 717 } 718 719 l2cap_run(); 720 } 721 722 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 723 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 724 // find channel for local_cid 725 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 726 if (channel) { 727 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 728 } 729 // process 730 l2cap_run(); 731 } 732 733 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 734 linked_item_t *it = (linked_item_t *) &l2cap_channels; 735 while (it->next){ 736 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 737 if ( ! BD_ADDR_CMP( channel->address, address) ){ 738 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 739 // failure, forward error code 740 l2cap_emit_channel_opened(channel, status); 741 // discard channel 742 it->next = it->next->next; 743 btstack_memory_l2cap_channel_free(channel); 744 } 745 } else { 746 it = it->next; 747 } 748 } 749 } 750 751 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 752 linked_item_t *it; 753 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 754 l2cap_channel_t * channel = (l2cap_channel_t *) it; 755 if ( ! BD_ADDR_CMP( channel->address, address) ){ 756 l2cap_handle_connection_complete(handle, channel); 757 } 758 } 759 // process 760 l2cap_run(); 761 } 762 763 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 764 765 bd_addr_t address; 766 hci_con_handle_t handle; 767 l2cap_channel_t * channel; 768 linked_item_t *it; 769 int hci_con_used; 770 771 switch(packet[0]){ 772 773 // handle connection complete events 774 case HCI_EVENT_CONNECTION_COMPLETE: 775 bt_flip_addr(address, &packet[5]); 776 if (packet[2] == 0){ 777 handle = READ_BT_16(packet, 3); 778 l2cap_handle_connection_success_for_addr(address, handle); 779 } else { 780 l2cap_handle_connection_failed_for_addr(address, packet[2]); 781 } 782 break; 783 784 // handle successful create connection cancel command 785 case HCI_EVENT_COMMAND_COMPLETE: 786 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 787 if (packet[5] == 0){ 788 bt_flip_addr(address, &packet[6]); 789 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 790 l2cap_handle_connection_failed_for_addr(address, 0x16); 791 } 792 } 793 l2cap_run(); // try sending signaling packets first 794 break; 795 796 case HCI_EVENT_COMMAND_STATUS: 797 l2cap_run(); // try sending signaling packets first 798 break; 799 800 // handle disconnection complete events 801 case HCI_EVENT_DISCONNECTION_COMPLETE: 802 // send l2cap disconnect events for all channels on this handle 803 handle = READ_BT_16(packet, 3); 804 it = (linked_item_t *) &l2cap_channels; 805 while (it->next){ 806 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 807 if ( channel->handle == handle ){ 808 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 809 it->next = it->next->next; 810 l2cap_emit_channel_closed(channel); 811 btstack_memory_l2cap_channel_free(channel); 812 } else { 813 it = it->next; 814 } 815 } 816 break; 817 818 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 819 l2cap_run(); // try sending signaling packets first 820 l2cap_hand_out_credits(); 821 break; 822 823 // HCI Connection Timeouts 824 case L2CAP_EVENT_TIMEOUT_CHECK: 825 handle = READ_BT_16(packet, 2); 826 if (hci_authentication_active_for_handle(handle)) break; 827 hci_con_used = 0; 828 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 829 channel = (l2cap_channel_t *) it; 830 if (channel->handle == handle) { 831 hci_con_used = 1; 832 } 833 } 834 if (hci_con_used) break; 835 if (!hci_can_send_packet_now_using_packet_buffer(HCI_COMMAND_DATA_PACKET)) break; 836 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 837 break; 838 839 case DAEMON_EVENT_HCI_PACKET_SENT: 840 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 841 channel = (l2cap_channel_t *) it; 842 if (channel->packet_handler) { 843 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 844 } 845 } 846 if (attribute_protocol_packet_handler) { 847 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 848 } 849 if (security_protocol_packet_handler) { 850 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 851 } 852 break; 853 854 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 855 handle = READ_BT_16(packet, 3); 856 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 857 channel = (l2cap_channel_t *) it; 858 if (channel->handle != handle) continue; 859 l2cap_handle_remote_supported_features_received(channel); 860 break; 861 } 862 863 case GAP_SECURITY_LEVEL: 864 handle = READ_BT_16(packet, 2); 865 log_info("l2cap - security level update"); 866 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 867 channel = (l2cap_channel_t *) it; 868 if (channel->handle != handle) continue; 869 870 log_info("l2cap - state %u", channel->state); 871 872 gap_security_level_t actual_level = packet[4]; 873 gap_security_level_t required_level = channel->required_security_level; 874 875 switch (channel->state){ 876 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 877 if (actual_level >= required_level){ 878 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 879 l2cap_emit_connection_request(channel); 880 } else { 881 channel->reason = 0x03; // security block 882 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 883 } 884 break; 885 886 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 887 if (actual_level >= required_level){ 888 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 889 } else { 890 // disconnnect, authentication not good enough 891 hci_disconnect_security_block(handle); 892 } 893 break; 894 895 default: 896 break; 897 } 898 } 899 break; 900 901 default: 902 break; 903 } 904 905 // pass on 906 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 907 908 l2cap_run(); 909 } 910 911 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 912 channel->remote_sig_id = identifier; 913 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 914 l2cap_run(); 915 } 916 917 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 918 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 919 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 920 signaling_responses[signaling_responses_pending].handle = handle; 921 signaling_responses[signaling_responses_pending].code = code; 922 signaling_responses[signaling_responses_pending].sig_id = sig_id; 923 signaling_responses[signaling_responses_pending].data = data; 924 signaling_responses_pending++; 925 l2cap_run(); 926 } 927 } 928 929 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 930 931 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x\n", handle, psm, source_cid); 932 l2cap_service_t *service = l2cap_get_service(psm); 933 if (!service) { 934 // 0x0002 PSM not supported 935 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 936 return; 937 } 938 939 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 940 if (!hci_connection) { 941 // 942 log_error("no hci_connection for handle %u\n", handle); 943 return; 944 } 945 946 // reject connection (0x03 security block) and disconnect if both have SSP, connection is not encrypted and PSM != SDP 947 if ( hci_ssp_supported_on_both_sides(handle) 948 && gap_security_level(handle) == LEVEL_0 949 && !l2cap_security_level_0_allowed_for_PSM(psm)){ 950 951 // 0x0003 Security Block 952 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0003); 953 return; 954 } 955 956 957 // alloc structure 958 // log_info("l2cap_handle_connection_request register channel\n"); 959 l2cap_channel_t * channel = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 960 if (!channel){ 961 // 0x0004 No resources available 962 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 963 return; 964 } 965 966 // fill in 967 BD_ADDR_COPY(channel->address, hci_connection->address); 968 channel->psm = psm; 969 channel->handle = handle; 970 channel->connection = service->connection; 971 channel->packet_handler = service->packet_handler; 972 channel->local_cid = l2cap_next_local_cid(); 973 channel->remote_cid = source_cid; 974 channel->local_mtu = service->mtu; 975 channel->remote_mtu = L2CAP_DEFAULT_MTU; 976 channel->packets_granted = 0; 977 channel->remote_sig_id = sig_id; 978 channel->required_security_level = service->required_security_level; 979 980 // limit local mtu to max acl packet length 981 if (channel->local_mtu > l2cap_max_mtu()) { 982 channel->local_mtu = l2cap_max_mtu(); 983 } 984 985 // set initial state 986 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 987 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 988 989 // add to connections list 990 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 991 992 // assert security requirements 993 gap_request_security_level(handle, channel->required_security_level); 994 } 995 996 void l2cap_accept_connection_internal(uint16_t local_cid){ 997 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 998 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 999 if (!channel) { 1000 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 1001 return; 1002 } 1003 1004 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 1005 1006 // process 1007 l2cap_run(); 1008 } 1009 1010 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 1011 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); 1012 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 1013 if (!channel) { 1014 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 1015 return; 1016 } 1017 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 1018 channel->reason = reason; 1019 l2cap_run(); 1020 } 1021 1022 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 1023 1024 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1025 1026 uint16_t flags = READ_BT_16(command, 6); 1027 if (flags & 1) { 1028 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 1029 } 1030 1031 // accept the other's configuration options 1032 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1033 uint16_t pos = 8; 1034 while (pos < end_pos){ 1035 uint8_t option_hint = command[pos] >> 7; 1036 uint8_t option_type = command[pos] & 0x7f; 1037 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 1038 pos++; 1039 uint8_t length = command[pos++]; 1040 // MTU { type(8): 1, len(8):2, MTU(16) } 1041 if (option_type == 1 && length == 2){ 1042 channel->remote_mtu = READ_BT_16(command, pos); 1043 // log_info("l2cap cid 0x%02x, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 1044 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 1045 } 1046 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 1047 if (option_type == 2 && length == 2){ 1048 channel->flush_timeout = READ_BT_16(command, pos); 1049 } 1050 // check for unknown options 1051 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 1052 log_info("l2cap cid %u, unknown options", channel->local_cid); 1053 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 1054 } 1055 pos += length; 1056 } 1057 } 1058 1059 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 1060 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 1061 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 1062 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 1063 return 1; 1064 } 1065 1066 1067 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 1068 1069 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1070 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1071 uint16_t result = 0; 1072 1073 log_info("L2CAP signaling handler code %u, state %u\n", code, channel->state); 1074 1075 // handle DISCONNECT REQUESTS seperately 1076 if (code == DISCONNECTION_REQUEST){ 1077 switch (channel->state){ 1078 case L2CAP_STATE_CONFIG: 1079 case L2CAP_STATE_OPEN: 1080 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1081 case L2CAP_STATE_WAIT_DISCONNECT: 1082 l2cap_handle_disconnect_request(channel, identifier); 1083 break; 1084 1085 default: 1086 // ignore in other states 1087 break; 1088 } 1089 return; 1090 } 1091 1092 // @STATEMACHINE(l2cap) 1093 switch (channel->state) { 1094 1095 case L2CAP_STATE_WAIT_CONNECT_RSP: 1096 switch (code){ 1097 case CONNECTION_RESPONSE: 1098 l2cap_stop_rtx(channel); 1099 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1100 switch (result) { 1101 case 0: 1102 // successful connection 1103 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1104 channel->state = L2CAP_STATE_CONFIG; 1105 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1106 break; 1107 case 1: 1108 // connection pending. get some coffee, but start the ERTX 1109 l2cap_start_ertx(channel); 1110 break; 1111 default: 1112 // channel closed 1113 channel->state = L2CAP_STATE_CLOSED; 1114 // map l2cap connection response result to BTstack status enumeration 1115 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1116 1117 // drop link key if security block 1118 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1119 hci_drop_link_key_for_bd_addr(&channel->address); 1120 } 1121 1122 // discard channel 1123 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1124 btstack_memory_l2cap_channel_free(channel); 1125 break; 1126 } 1127 break; 1128 1129 default: 1130 //@TODO: implement other signaling packets 1131 break; 1132 } 1133 break; 1134 1135 case L2CAP_STATE_CONFIG: 1136 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1137 switch (code) { 1138 case CONFIGURE_REQUEST: 1139 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1140 l2cap_signaling_handle_configure_request(channel, command); 1141 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1142 // only done if continuation not set 1143 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1144 } 1145 break; 1146 case CONFIGURE_RESPONSE: 1147 l2cap_stop_rtx(channel); 1148 switch (result){ 1149 case 0: // success 1150 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1151 break; 1152 case 4: // pending 1153 l2cap_start_ertx(channel); 1154 break; 1155 default: 1156 // retry on negative result 1157 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1158 break; 1159 } 1160 break; 1161 default: 1162 break; 1163 } 1164 if (l2cap_channel_ready_for_open(channel)){ 1165 // for open: 1166 channel->state = L2CAP_STATE_OPEN; 1167 l2cap_emit_channel_opened(channel, 0); 1168 l2cap_emit_credits(channel, 1); 1169 } 1170 break; 1171 1172 case L2CAP_STATE_WAIT_DISCONNECT: 1173 switch (code) { 1174 case DISCONNECTION_RESPONSE: 1175 l2cap_finialize_channel_close(channel); 1176 break; 1177 default: 1178 //@TODO: implement other signaling packets 1179 break; 1180 } 1181 break; 1182 1183 case L2CAP_STATE_CLOSED: 1184 // @TODO handle incoming requests 1185 break; 1186 1187 case L2CAP_STATE_OPEN: 1188 //@TODO: implement other signaling packets, e.g. re-configure 1189 break; 1190 default: 1191 break; 1192 } 1193 // log_info("new state %u\n", channel->state); 1194 } 1195 1196 1197 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1198 1199 // get code, signalind identifier and command len 1200 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1201 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1202 1203 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1204 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1205 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1206 return; 1207 } 1208 1209 // general commands without an assigned channel 1210 switch(code) { 1211 1212 case CONNECTION_REQUEST: { 1213 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1214 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1215 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1216 return; 1217 } 1218 1219 case ECHO_REQUEST: 1220 l2cap_register_signaling_response(handle, code, sig_id, 0); 1221 return; 1222 1223 case INFORMATION_REQUEST: { 1224 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1225 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1226 return; 1227 } 1228 1229 default: 1230 break; 1231 } 1232 1233 1234 // Get potential destination CID 1235 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1236 1237 // Find channel for this sig_id and connection handle 1238 linked_item_t *it; 1239 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1240 l2cap_channel_t * channel = (l2cap_channel_t *) it; 1241 if (channel->handle == handle) { 1242 if (code & 1) { 1243 // match odd commands (responses) by previous signaling identifier 1244 if (channel->local_sig_id == sig_id) { 1245 l2cap_signaling_handler_channel(channel, command); 1246 break; 1247 } 1248 } else { 1249 // match even commands (requests) by local channel id 1250 if (channel->local_cid == dest_cid) { 1251 l2cap_signaling_handler_channel(channel, command); 1252 break; 1253 } 1254 } 1255 } 1256 } 1257 } 1258 1259 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 1260 1261 // Get Channel ID 1262 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1263 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1264 1265 switch (channel_id) { 1266 1267 case L2CAP_CID_SIGNALING: { 1268 1269 uint16_t command_offset = 8; 1270 while (command_offset < size) { 1271 1272 // handle signaling commands 1273 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1274 1275 // increment command_offset 1276 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1277 } 1278 break; 1279 } 1280 1281 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1282 if (attribute_protocol_packet_handler) { 1283 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1284 } 1285 break; 1286 1287 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1288 if (security_protocol_packet_handler) { 1289 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1290 } 1291 break; 1292 1293 case L2CAP_CID_SIGNALING_LE: { 1294 // not implemented yet for LE Peripheral 1295 uint8_t sig_id = packet[COMPLETE_L2CAP_HEADER + 1]; 1296 l2cap_register_signaling_response(handle, COMMAND_REJECT_LE, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1297 break; 1298 } 1299 1300 default: { 1301 // Find channel for this channel_id and connection handle 1302 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1303 if (channel) { 1304 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1305 } 1306 break; 1307 } 1308 } 1309 } 1310 1311 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1312 switch (packet_type) { 1313 case HCI_EVENT_PACKET: 1314 l2cap_event_handler(packet, size); 1315 break; 1316 case HCI_ACL_DATA_PACKET: 1317 l2cap_acl_handler(packet, size); 1318 break; 1319 default: 1320 break; 1321 } 1322 l2cap_run(); 1323 } 1324 1325 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1326 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1327 channel->state = L2CAP_STATE_CLOSED; 1328 l2cap_emit_channel_closed(channel); 1329 // discard channel 1330 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1331 btstack_memory_l2cap_channel_free(channel); 1332 } 1333 1334 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1335 linked_item_t *it; 1336 1337 // close open channels 1338 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 1339 l2cap_service_t * service = ((l2cap_service_t *) it); 1340 if ( service->psm == psm){ 1341 return service; 1342 }; 1343 } 1344 return NULL; 1345 } 1346 1347 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){ 1348 1349 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1350 1351 // check for alread registered psm 1352 // TODO: emit error event 1353 l2cap_service_t *service = l2cap_get_service(psm); 1354 if (service) { 1355 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 1356 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1357 return; 1358 } 1359 1360 // alloc structure 1361 // TODO: emit error event 1362 service = (l2cap_service_t *) btstack_memory_l2cap_service_get(); 1363 if (!service) { 1364 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 1365 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1366 return; 1367 } 1368 1369 // fill in 1370 service->psm = psm; 1371 service->mtu = mtu; 1372 service->connection = connection; 1373 service->packet_handler = packet_handler; 1374 service->required_security_level = security_level; 1375 1376 // add to services list 1377 linked_list_add(&l2cap_services, (linked_item_t *) service); 1378 1379 // enable page scan 1380 hci_connectable_control(1); 1381 1382 // done 1383 l2cap_emit_service_registered(connection, 0, psm); 1384 } 1385 1386 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1387 1388 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1389 1390 l2cap_service_t *service = l2cap_get_service(psm); 1391 if (!service) return; 1392 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1393 btstack_memory_l2cap_service_free(service); 1394 1395 // disable page scan when no services registered 1396 if (!linked_list_empty(&l2cap_services)) return; 1397 hci_connectable_control(0); 1398 } 1399 1400 // 1401 void l2cap_close_connection(void *connection){ 1402 linked_item_t *it; 1403 1404 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 1405 l2cap_channel_t * channel; 1406 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1407 channel = (l2cap_channel_t *) it; 1408 if (channel->connection == connection) { 1409 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1410 } 1411 } 1412 1413 // unregister services 1414 it = (linked_item_t *) &l2cap_services; 1415 while (it->next) { 1416 l2cap_service_t * service = (l2cap_service_t *) it->next; 1417 if (service->connection == connection){ 1418 it->next = it->next->next; 1419 btstack_memory_l2cap_service_free(service); 1420 } else { 1421 it = it->next; 1422 } 1423 } 1424 1425 // process 1426 l2cap_run(); 1427 } 1428 1429 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1430 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1431 switch(channel_id){ 1432 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1433 attribute_protocol_packet_handler = packet_handler; 1434 break; 1435 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1436 security_protocol_packet_handler = packet_handler; 1437 break; 1438 } 1439 } 1440 1441 #ifdef HAVE_BLE 1442 // Request LE connection parameter update 1443 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){ 1444 if (!hci_can_send_packet_now_using_packet_buffer(HCI_ACL_DATA_PACKET)){ 1445 log_info("l2cap_send_signaling_packet, cannot send\n"); 1446 return BTSTACK_ACL_BUFFERS_FULL; 1447 } 1448 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 1449 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 1450 uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); 1451 return hci_send_acl_packet(acl_buffer, len); 1452 } 1453 #endif 1454 1455