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