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 83 // prototypes 84 static void l2cap_finialize_channel_close(l2cap_channel_t *channel); 85 static l2cap_service_t * l2cap_get_service(uint16_t psm); 86 static void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status); 87 static void l2cap_emit_channel_closed(l2cap_channel_t *channel); 88 static void l2cap_emit_connection_request(l2cap_channel_t *channel); 89 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel); 90 91 92 void l2cap_init(){ 93 new_credits_blocked = 0; 94 signaling_responses_pending = 0; 95 96 l2cap_channels = NULL; 97 l2cap_services = NULL; 98 99 packet_handler = null_packet_handler; 100 attribute_protocol_packet_handler = NULL; 101 security_protocol_packet_handler = NULL; 102 103 // 104 // register callback with HCI 105 // 106 hci_register_packet_handler(&l2cap_packet_handler); 107 hci_connectable_control(0); // no services yet 108 } 109 110 111 /** Register L2CAP packet handlers */ 112 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 113 } 114 void l2cap_register_packet_handler(void (*handler)(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 115 packet_handler = handler; 116 } 117 118 // notify client/protocol handler 119 void l2cap_dispatch(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 120 if (channel->packet_handler) { 121 (* (channel->packet_handler))(type, channel->local_cid, data, size); 122 } else { 123 (*packet_handler)(channel->connection, type, channel->local_cid, data, size); 124 } 125 } 126 127 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 128 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", 129 status, bd_addr_to_str(channel->address), channel->handle, channel->psm, 130 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 131 uint8_t event[23]; 132 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 133 event[1] = sizeof(event) - 2; 134 event[2] = status; 135 bt_flip_addr(&event[3], channel->address); 136 bt_store_16(event, 9, channel->handle); 137 bt_store_16(event, 11, channel->psm); 138 bt_store_16(event, 13, channel->local_cid); 139 bt_store_16(event, 15, channel->remote_cid); 140 bt_store_16(event, 17, channel->local_mtu); 141 bt_store_16(event, 19, channel->remote_mtu); 142 bt_store_16(event, 19, channel->flush_timeout); 143 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 144 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 145 } 146 147 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 148 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 149 uint8_t event[4]; 150 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 151 event[1] = sizeof(event) - 2; 152 bt_store_16(event, 2, channel->local_cid); 153 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 154 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 155 } 156 157 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 158 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 159 bd_addr_to_str(channel->address), channel->handle, channel->psm, channel->local_cid, channel->remote_cid); 160 uint8_t event[16]; 161 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 162 event[1] = sizeof(event) - 2; 163 bt_flip_addr(&event[2], channel->address); 164 bt_store_16(event, 8, channel->handle); 165 bt_store_16(event, 10, channel->psm); 166 bt_store_16(event, 12, channel->local_cid); 167 bt_store_16(event, 14, channel->remote_cid); 168 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 169 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 170 } 171 172 static void l2cap_emit_service_registered(void *connection, uint8_t status, uint16_t psm){ 173 log_info("L2CAP_EVENT_SERVICE_REGISTERED status 0x%x psm 0x%x", status, psm); 174 uint8_t event[5]; 175 event[0] = L2CAP_EVENT_SERVICE_REGISTERED; 176 event[1] = sizeof(event) - 2; 177 event[2] = status; 178 bt_store_16(event, 3, psm); 179 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 180 (*packet_handler)(connection, HCI_EVENT_PACKET, 0, event, sizeof(event)); 181 } 182 183 void l2cap_emit_credits(l2cap_channel_t *channel, uint8_t credits) { 184 185 log_info("L2CAP_EVENT_CREDITS local_cid 0x%x credits %u", channel->local_cid, credits); 186 // track credits 187 channel->packets_granted += credits; 188 189 uint8_t event[5]; 190 event[0] = L2CAP_EVENT_CREDITS; 191 event[1] = sizeof(event) - 2; 192 bt_store_16(event, 2, channel->local_cid); 193 event[4] = credits; 194 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 195 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 196 } 197 198 void l2cap_block_new_credits(uint8_t blocked){ 199 new_credits_blocked = blocked; 200 } 201 202 void l2cap_hand_out_credits(void){ 203 204 if (new_credits_blocked) return; // we're told not to. used by daemon 205 206 linked_item_t *it; 207 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 208 if (!hci_number_free_acl_slots()) return; 209 l2cap_channel_t * channel = (l2cap_channel_t *) it; 210 if (channel->state != L2CAP_STATE_OPEN) continue; 211 if (hci_number_outgoing_packets(channel->handle) < NR_BUFFERED_ACL_PACKETS && channel->packets_granted == 0) { 212 l2cap_emit_credits(channel, 1); 213 } 214 } 215 } 216 217 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 218 linked_item_t *it; 219 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 220 l2cap_channel_t * channel = (l2cap_channel_t *) it; 221 if ( channel->local_cid == local_cid) { 222 return channel; 223 } 224 } 225 return NULL; 226 } 227 228 int l2cap_can_send_packet_now(uint16_t local_cid){ 229 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 230 if (!channel) return 0; 231 if (!channel->packets_granted) return 0; 232 return hci_can_send_packet_now(HCI_ACL_DATA_PACKET); 233 } 234 235 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 236 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 237 if (channel) { 238 return channel->remote_mtu; 239 } 240 return 0; 241 } 242 243 static l2cap_channel_t * l2cap_channel_for_rtx_timer(timer_source_t * ts){ 244 linked_item_t *it; 245 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 246 l2cap_channel_t * channel = (l2cap_channel_t *) it; 247 if ( &channel->rtx == ts) { 248 return channel; 249 } 250 } 251 return NULL; 252 } 253 254 static void l2cap_rtx_timeout(timer_source_t * ts){ 255 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 256 if (!ts) return; 257 258 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 259 260 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 261 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 262 // notify client 263 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 264 265 // discard channel 266 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 267 btstack_memory_l2cap_channel_free(channel); 268 } 269 270 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 271 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 272 run_loop_remove_timer(&channel->rtx); 273 } 274 275 static void l2cap_start_rtx(l2cap_channel_t * channel){ 276 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 277 l2cap_stop_rtx(channel); 278 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 279 run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 280 run_loop_add_timer(&channel->rtx); 281 } 282 283 static void l2cap_start_ertx(l2cap_channel_t * channel){ 284 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 285 l2cap_stop_rtx(channel); 286 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 287 run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 288 run_loop_add_timer(&channel->rtx); 289 } 290 291 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 292 return psm != PSM_SDP; 293 } 294 295 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 296 297 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 298 log_info("l2cap_send_signaling_packet, cannot send\n"); 299 return BTSTACK_ACL_BUFFERS_FULL; 300 } 301 302 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 303 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 304 va_list argptr; 305 va_start(argptr, identifier); 306 uint16_t len = l2cap_create_signaling_internal(acl_buffer, handle, cmd, identifier, argptr); 307 va_end(argptr); 308 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 309 return hci_send_acl_packet(acl_buffer, len); 310 } 311 312 uint8_t *l2cap_get_outgoing_buffer(void){ 313 return hci_get_outgoing_acl_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 314 } 315 316 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 317 318 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 319 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", local_cid); 320 return BTSTACK_ACL_BUFFERS_FULL; 321 } 322 323 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 324 if (!channel) { 325 log_error("l2cap_send_internal no channel for cid 0x%02x\n", local_cid); 326 return -1; // TODO: define error 327 } 328 329 if (channel->packets_granted == 0){ 330 log_error("l2cap_send_internal cid 0x%02x, no credits!\n", local_cid); 331 return -1; // TODO: define error 332 } 333 334 --channel->packets_granted; 335 336 log_debug("l2cap_send_internal cid 0x%02x, handle %u, 1 credit used, credits left %u;\n", 337 local_cid, channel->handle, channel->packets_granted); 338 339 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 340 341 // 0 - Connection handle : PB=10 : BC=00 342 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 343 // 2 - ACL length 344 bt_store_16(acl_buffer, 2, len + 4); 345 // 4 - L2CAP packet length 346 bt_store_16(acl_buffer, 4, len + 0); 347 // 6 - L2CAP channel DEST 348 bt_store_16(acl_buffer, 6, channel->remote_cid); 349 // send 350 int err = hci_send_acl_packet(acl_buffer, len+8); 351 352 l2cap_hand_out_credits(); 353 354 return err; 355 } 356 357 int l2cap_send_prepared_connectionless(uint16_t handle, uint16_t cid, uint16_t len){ 358 359 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 360 log_info("l2cap_send_prepared_to_handle cid 0x%02x, cannot send\n", cid); 361 return BTSTACK_ACL_BUFFERS_FULL; 362 } 363 364 log_debug("l2cap_send_prepared_to_handle cid 0x%02x, handle %u\n", cid, handle); 365 366 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 367 368 // 0 - Connection handle : PB=10 : BC=00 369 bt_store_16(acl_buffer, 0, handle | (2 << 12) | (0 << 14)); 370 // 2 - ACL length 371 bt_store_16(acl_buffer, 2, len + 4); 372 // 4 - L2CAP packet length 373 bt_store_16(acl_buffer, 4, len + 0); 374 // 6 - L2CAP channel DEST 375 bt_store_16(acl_buffer, 6, cid); 376 // send 377 int err = hci_send_acl_packet(acl_buffer, len+8); 378 379 l2cap_hand_out_credits(); 380 381 return err; 382 } 383 384 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 385 386 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 387 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", local_cid); 388 return BTSTACK_ACL_BUFFERS_FULL; 389 } 390 391 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 392 393 memcpy(&acl_buffer[8], data, len); 394 395 return l2cap_send_prepared(local_cid, len); 396 } 397 398 int l2cap_send_connectionless(uint16_t handle, uint16_t cid, uint8_t *data, uint16_t len){ 399 400 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 401 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", cid); 402 return BTSTACK_ACL_BUFFERS_FULL; 403 } 404 405 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 406 407 memcpy(&acl_buffer[8], data, len); 408 409 return l2cap_send_prepared_connectionless(handle, cid, len); 410 } 411 412 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 413 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 414 } 415 416 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 417 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 418 } 419 420 421 422 // MARK: L2CAP_RUN 423 // process outstanding signaling tasks 424 void l2cap_run(void){ 425 426 // check pending signaling responses 427 while (signaling_responses_pending){ 428 429 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)) break; 430 431 hci_con_handle_t handle = signaling_responses[0].handle; 432 uint8_t sig_id = signaling_responses[0].sig_id; 433 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 434 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 435 436 switch (signaling_responses[0].code){ 437 case CONNECTION_REQUEST: 438 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 439 // also disconnect if result is 0x0003 - security blocked 440 hci_disconnect_security_block(handle); 441 break; 442 case ECHO_REQUEST: 443 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 444 break; 445 case INFORMATION_REQUEST: 446 switch (infoType){ 447 case 1: { // Connectionless MTU 448 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 449 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 450 break; 451 } 452 case 2: { // Extended Features Supported 453 // extended features request supported, only supporing fixed channel map 454 uint32_t features = 0x80; 455 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 456 break; 457 } 458 case 3: { // Fixed Channels Supported 459 uint8_t map[8]; 460 memset(map, 0, 8); 461 map[0] = 0x01; // L2CAP Signaling Channel 462 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 463 break; 464 } 465 default: 466 // all other types are not supported 467 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 468 break; 469 } 470 break; 471 case COMMAND_REJECT: 472 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result); 473 break; 474 default: 475 // should not happen 476 break; 477 } 478 479 // remove first item 480 signaling_responses_pending--; 481 int i; 482 for (i=0; i < signaling_responses_pending; i++){ 483 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 484 } 485 } 486 487 uint8_t config_options[4]; 488 linked_item_t *it; 489 linked_item_t *next; 490 for (it = (linked_item_t *) l2cap_channels; it ; it = next){ 491 next = it->next; // cache next item as current item might get freed 492 493 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 494 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)) break; 495 496 l2cap_channel_t * channel = (l2cap_channel_t *) it; 497 498 // log_info("l2cap_run: state %u, var 0x%02x\n", channel->state, channel->state_var); 499 500 501 switch (channel->state){ 502 503 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 504 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 505 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 506 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 507 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 508 } 509 break; 510 511 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 512 // send connection request - set state first 513 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 514 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 515 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 516 break; 517 518 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 519 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 520 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 521 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); // -- remove from list 522 btstack_memory_l2cap_channel_free(channel); 523 break; 524 525 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 526 channel->state = L2CAP_STATE_CONFIG; 527 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 528 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 529 break; 530 531 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 532 // success, start l2cap handshake 533 channel->local_sig_id = l2cap_next_sig_id(); 534 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 535 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 536 l2cap_start_rtx(channel); 537 break; 538 539 case L2CAP_STATE_CONFIG: 540 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 541 uint16_t flags = 0; 542 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 543 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 544 flags = 1; 545 } else { 546 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 547 } 548 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 549 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 550 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 551 config_options[0] = 1; // MTU 552 config_options[1] = 2; // len param 553 bt_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 554 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 555 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 556 } else { 557 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 558 } 559 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 560 } 561 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 562 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 563 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 564 channel->local_sig_id = l2cap_next_sig_id(); 565 config_options[0] = 1; // MTU 566 config_options[1] = 2; // len param 567 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 568 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 569 l2cap_start_rtx(channel); 570 } 571 if (l2cap_channel_ready_for_open(channel)){ 572 channel->state = L2CAP_STATE_OPEN; 573 l2cap_emit_channel_opened(channel, 0); // success 574 l2cap_emit_credits(channel, 1); 575 } 576 break; 577 578 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 579 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 580 // 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 :) 581 l2cap_finialize_channel_close(channel); // -- remove from list 582 break; 583 584 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 585 channel->local_sig_id = l2cap_next_sig_id(); 586 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 587 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 588 break; 589 default: 590 break; 591 } 592 } 593 } 594 595 uint16_t l2cap_max_mtu(void){ 596 return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE; 597 } 598 599 // open outgoing L2CAP channel 600 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 601 bd_addr_t address, uint16_t psm, uint16_t mtu){ 602 603 log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 604 605 // alloc structure 606 l2cap_channel_t * chan = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 607 if (!chan) { 608 // emit error event 609 l2cap_channel_t dummy_channel; 610 BD_ADDR_COPY(dummy_channel.address, address); 611 dummy_channel.psm = psm; 612 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 613 return; 614 } 615 // limit local mtu to max acl packet length 616 if (mtu > l2cap_max_mtu()) { 617 mtu = l2cap_max_mtu(); 618 } 619 620 // fill in 621 BD_ADDR_COPY(chan->address, address); 622 chan->psm = psm; 623 chan->handle = 0; 624 chan->connection = connection; 625 chan->packet_handler = packet_handler; 626 chan->remote_mtu = L2CAP_MINIMAL_MTU; 627 chan->local_mtu = mtu; 628 chan->packets_granted = 0; 629 630 // set initial state 631 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 632 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 633 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 634 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 635 636 // add to connections list 637 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 638 639 l2cap_run(); 640 } 641 642 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 643 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 644 // find channel for local_cid 645 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 646 if (channel) { 647 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 648 } 649 // process 650 l2cap_run(); 651 } 652 653 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 654 linked_item_t *it = (linked_item_t *) &l2cap_channels; 655 while (it->next){ 656 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 657 if ( ! BD_ADDR_CMP( channel->address, address) ){ 658 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 659 // failure, forward error code 660 l2cap_emit_channel_opened(channel, status); 661 // discard channel 662 it->next = it->next->next; 663 btstack_memory_l2cap_channel_free(channel); 664 } 665 } else { 666 it = it->next; 667 } 668 } 669 } 670 671 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 672 linked_item_t *it; 673 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 674 l2cap_channel_t * channel = (l2cap_channel_t *) it; 675 if ( ! BD_ADDR_CMP( channel->address, address) ){ 676 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 677 // success, start l2cap handshake 678 channel->handle = handle; 679 channel->local_cid = l2cap_next_local_cid(); 680 // check remote SSP feature first 681 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 682 } 683 } 684 } 685 // process 686 l2cap_run(); 687 } 688 689 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 690 691 bd_addr_t address; 692 hci_con_handle_t handle; 693 l2cap_channel_t * channel; 694 linked_item_t *it; 695 int hci_con_used; 696 697 switch(packet[0]){ 698 699 // handle connection complete events 700 case HCI_EVENT_CONNECTION_COMPLETE: 701 bt_flip_addr(address, &packet[5]); 702 if (packet[2] == 0){ 703 handle = READ_BT_16(packet, 3); 704 l2cap_handle_connection_success_for_addr(address, handle); 705 } else { 706 l2cap_handle_connection_failed_for_addr(address, packet[2]); 707 } 708 break; 709 710 // handle successful create connection cancel command 711 case HCI_EVENT_COMMAND_COMPLETE: 712 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 713 if (packet[5] == 0){ 714 bt_flip_addr(address, &packet[6]); 715 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 716 l2cap_handle_connection_failed_for_addr(address, 0x16); 717 } 718 } 719 l2cap_run(); // try sending signaling packets first 720 break; 721 722 case HCI_EVENT_COMMAND_STATUS: 723 l2cap_run(); // try sending signaling packets first 724 break; 725 726 // handle disconnection complete events 727 case HCI_EVENT_DISCONNECTION_COMPLETE: 728 // send l2cap disconnect events for all channels on this handle 729 handle = READ_BT_16(packet, 3); 730 it = (linked_item_t *) &l2cap_channels; 731 while (it->next){ 732 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 733 if ( channel->handle == handle ){ 734 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 735 it->next = it->next->next; 736 l2cap_emit_channel_closed(channel); 737 btstack_memory_l2cap_channel_free(channel); 738 } else { 739 it = it->next; 740 } 741 } 742 break; 743 744 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 745 l2cap_run(); // try sending signaling packets first 746 l2cap_hand_out_credits(); 747 break; 748 749 // HCI Connection Timeouts 750 case L2CAP_EVENT_TIMEOUT_CHECK: 751 handle = READ_BT_16(packet, 2); 752 if (hci_authentication_active_for_handle(handle)) break; 753 hci_con_used = 0; 754 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 755 channel = (l2cap_channel_t *) it; 756 if (channel->handle == handle) { 757 hci_con_used = 1; 758 } 759 } 760 if (hci_con_used) break; 761 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 762 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 763 break; 764 765 case DAEMON_EVENT_HCI_PACKET_SENT: 766 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 767 channel = (l2cap_channel_t *) it; 768 if (channel->packet_handler) { 769 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 770 } 771 } 772 if (attribute_protocol_packet_handler) { 773 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 774 } 775 if (security_protocol_packet_handler) { 776 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 777 } 778 break; 779 780 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 781 handle = READ_BT_16(packet, 3); 782 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 783 channel = (l2cap_channel_t *) it; 784 if (channel->handle != handle) continue; 785 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) continue; 786 // we have been waiting for remote supported features, if both support SSP, 787 if (hci_ssp_supported_on_both_sides(channel->handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 788 // request security level 2 789 gap_request_security_level(channel->handle, LEVEL_2); 790 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 791 break; 792 } 793 // fine, go ahead 794 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 795 break; 796 } 797 798 case GAP_SECURITY_LEVEL: 799 handle = READ_BT_16(packet, 2); 800 log_info("GAP_SECURITY_LEVEL"); 801 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 802 channel = (l2cap_channel_t *) it; 803 gap_security_level_t actual_level = packet[4]; 804 if (channel->handle != handle) continue; 805 switch (channel->state){ 806 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 807 log_info("gap incoming"); 808 if (actual_level >= channel->required_security_level){ 809 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 810 l2cap_emit_connection_request(channel); 811 } else { 812 channel->reason = 0x03; // security block 813 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 814 } 815 break; 816 817 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 818 log_info("gap outgoing"); 819 if (actual_level >= channel->required_security_level){ 820 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 821 } else { 822 // disconnnect, authentication not good enough 823 hci_disconnect_security_block(handle); 824 } 825 break; 826 827 default: 828 break; 829 } 830 } 831 break; 832 833 default: 834 break; 835 } 836 837 // pass on 838 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 839 } 840 841 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 842 channel->remote_sig_id = identifier; 843 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 844 l2cap_run(); 845 } 846 847 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 848 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 849 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 850 signaling_responses[signaling_responses_pending].handle = handle; 851 signaling_responses[signaling_responses_pending].code = code; 852 signaling_responses[signaling_responses_pending].sig_id = sig_id; 853 signaling_responses[signaling_responses_pending].data = data; 854 signaling_responses_pending++; 855 l2cap_run(); 856 } 857 } 858 859 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 860 861 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x\n", handle, psm, source_cid); 862 l2cap_service_t *service = l2cap_get_service(psm); 863 if (!service) { 864 // 0x0002 PSM not supported 865 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 866 return; 867 } 868 869 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 870 if (!hci_connection) { 871 // 872 log_error("no hci_connection for handle %u\n", handle); 873 return; 874 } 875 876 // reject connection (0x03 security block) and disconnect if both have SSP, connection is not encrypted and PSM != SDP 877 if ( l2cap_security_level_0_allowed_for_PSM(psm) 878 && hci_ssp_supported_on_both_sides(handle) 879 && gap_security_level(handle) == LEVEL_0){ 880 881 // 0x0003 Security Block 882 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0003); 883 return; 884 } 885 886 887 // alloc structure 888 // log_info("l2cap_handle_connection_request register channel\n"); 889 l2cap_channel_t * channel = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 890 if (!channel){ 891 // 0x0004 No resources available 892 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 893 return; 894 } 895 896 // fill in 897 BD_ADDR_COPY(channel->address, hci_connection->address); 898 channel->psm = psm; 899 channel->handle = handle; 900 channel->connection = service->connection; 901 channel->packet_handler = service->packet_handler; 902 channel->local_cid = l2cap_next_local_cid(); 903 channel->remote_cid = source_cid; 904 channel->local_mtu = service->mtu; 905 channel->remote_mtu = L2CAP_DEFAULT_MTU; 906 channel->packets_granted = 0; 907 channel->remote_sig_id = sig_id; 908 channel->required_security_level = service->required_security_level; 909 910 // limit local mtu to max acl packet length 911 if (channel->local_mtu > l2cap_max_mtu()) { 912 channel->local_mtu = l2cap_max_mtu(); 913 } 914 915 // set initial state 916 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 917 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 918 919 // add to connections list 920 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 921 922 // assert security requirements 923 gap_request_security_level(handle, channel->required_security_level); 924 } 925 926 void l2cap_accept_connection_internal(uint16_t local_cid){ 927 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 928 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 929 if (!channel) { 930 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 931 return; 932 } 933 934 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 935 936 // process 937 l2cap_run(); 938 } 939 940 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 941 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); 942 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 943 if (!channel) { 944 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 945 return; 946 } 947 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 948 channel->reason = reason; 949 l2cap_run(); 950 } 951 952 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 953 954 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 955 956 uint16_t flags = READ_BT_16(command, 6); 957 if (flags & 1) { 958 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 959 } 960 961 // accept the other's configuration options 962 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 963 uint16_t pos = 8; 964 while (pos < end_pos){ 965 uint8_t option_hint = command[pos] >> 7; 966 uint8_t option_type = command[pos] & 0x7f; 967 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 968 pos++; 969 uint8_t length = command[pos++]; 970 // MTU { type(8): 1, len(8):2, MTU(16) } 971 if (option_type == 1 && length == 2){ 972 channel->remote_mtu = READ_BT_16(command, pos); 973 // log_info("l2cap cid 0x%02x, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 974 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 975 } 976 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 977 if (option_type == 2 && length == 2){ 978 channel->flush_timeout = READ_BT_16(command, pos); 979 } 980 // check for unknown options 981 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 982 log_info("l2cap cid %u, unknown options", channel->local_cid); 983 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 984 } 985 pos += length; 986 } 987 } 988 989 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 990 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 991 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 992 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 993 return 1; 994 } 995 996 997 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 998 999 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1000 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1001 uint16_t result = 0; 1002 1003 log_info("L2CAP signaling handler code %u, state %u\n", code, channel->state); 1004 1005 // handle DISCONNECT REQUESTS seperately 1006 if (code == DISCONNECTION_REQUEST){ 1007 switch (channel->state){ 1008 case L2CAP_STATE_CONFIG: 1009 case L2CAP_STATE_OPEN: 1010 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1011 case L2CAP_STATE_WAIT_DISCONNECT: 1012 l2cap_handle_disconnect_request(channel, identifier); 1013 break; 1014 1015 default: 1016 // ignore in other states 1017 break; 1018 } 1019 return; 1020 } 1021 1022 // @STATEMACHINE(l2cap) 1023 switch (channel->state) { 1024 1025 case L2CAP_STATE_WAIT_CONNECT_RSP: 1026 switch (code){ 1027 case CONNECTION_RESPONSE: 1028 l2cap_stop_rtx(channel); 1029 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1030 switch (result) { 1031 case 0: 1032 // successful connection 1033 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1034 channel->state = L2CAP_STATE_CONFIG; 1035 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1036 break; 1037 case 1: 1038 // connection pending. get some coffee, but start the ERTX 1039 l2cap_start_ertx(channel); 1040 break; 1041 default: 1042 // channel closed 1043 channel->state = L2CAP_STATE_CLOSED; 1044 // map l2cap connection response result to BTstack status enumeration 1045 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1046 1047 // drop link key if security block 1048 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1049 hci_drop_link_key_for_bd_addr(&channel->address); 1050 } 1051 1052 // discard channel 1053 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1054 btstack_memory_l2cap_channel_free(channel); 1055 break; 1056 } 1057 break; 1058 1059 default: 1060 //@TODO: implement other signaling packets 1061 break; 1062 } 1063 break; 1064 1065 case L2CAP_STATE_CONFIG: 1066 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1067 switch (code) { 1068 case CONFIGURE_REQUEST: 1069 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1070 l2cap_signaling_handle_configure_request(channel, command); 1071 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1072 // only done if continuation not set 1073 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1074 } 1075 break; 1076 case CONFIGURE_RESPONSE: 1077 l2cap_stop_rtx(channel); 1078 switch (result){ 1079 case 0: // success 1080 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1081 break; 1082 case 4: // pending 1083 l2cap_start_ertx(channel); 1084 break; 1085 default: 1086 // retry on negative result 1087 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1088 break; 1089 } 1090 break; 1091 default: 1092 break; 1093 } 1094 if (l2cap_channel_ready_for_open(channel)){ 1095 // for open: 1096 channel->state = L2CAP_STATE_OPEN; 1097 l2cap_emit_channel_opened(channel, 0); 1098 l2cap_emit_credits(channel, 1); 1099 } 1100 break; 1101 1102 case L2CAP_STATE_WAIT_DISCONNECT: 1103 switch (code) { 1104 case DISCONNECTION_RESPONSE: 1105 l2cap_finialize_channel_close(channel); 1106 break; 1107 default: 1108 //@TODO: implement other signaling packets 1109 break; 1110 } 1111 break; 1112 1113 case L2CAP_STATE_CLOSED: 1114 // @TODO handle incoming requests 1115 break; 1116 1117 case L2CAP_STATE_OPEN: 1118 //@TODO: implement other signaling packets, e.g. re-configure 1119 break; 1120 default: 1121 break; 1122 } 1123 // log_info("new state %u\n", channel->state); 1124 } 1125 1126 1127 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1128 1129 // get code, signalind identifier and command len 1130 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1131 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1132 1133 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1134 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1135 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1136 return; 1137 } 1138 1139 // general commands without an assigned channel 1140 switch(code) { 1141 1142 case CONNECTION_REQUEST: { 1143 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1144 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1145 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1146 return; 1147 } 1148 1149 case ECHO_REQUEST: 1150 l2cap_register_signaling_response(handle, code, sig_id, 0); 1151 return; 1152 1153 case INFORMATION_REQUEST: { 1154 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1155 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1156 return; 1157 } 1158 1159 default: 1160 break; 1161 } 1162 1163 1164 // Get potential destination CID 1165 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1166 1167 // Find channel for this sig_id and connection handle 1168 linked_item_t *it; 1169 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1170 l2cap_channel_t * channel = (l2cap_channel_t *) it; 1171 if (channel->handle == handle) { 1172 if (code & 1) { 1173 // match odd commands (responses) by previous signaling identifier 1174 if (channel->local_sig_id == sig_id) { 1175 l2cap_signaling_handler_channel(channel, command); 1176 break; 1177 } 1178 } else { 1179 // match even commands (requests) by local channel id 1180 if (channel->local_cid == dest_cid) { 1181 l2cap_signaling_handler_channel(channel, command); 1182 break; 1183 } 1184 } 1185 } 1186 } 1187 } 1188 1189 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 1190 1191 // Get Channel ID 1192 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1193 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1194 1195 switch (channel_id) { 1196 1197 case L2CAP_CID_SIGNALING: { 1198 1199 uint16_t command_offset = 8; 1200 while (command_offset < size) { 1201 1202 // handle signaling commands 1203 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1204 1205 // increment command_offset 1206 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1207 } 1208 break; 1209 } 1210 1211 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1212 if (attribute_protocol_packet_handler) { 1213 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1214 } 1215 break; 1216 1217 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1218 if (security_protocol_packet_handler) { 1219 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1220 } 1221 break; 1222 1223 default: { 1224 // Find channel for this channel_id and connection handle 1225 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1226 if (channel) { 1227 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1228 } 1229 break; 1230 } 1231 } 1232 } 1233 1234 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1235 switch (packet_type) { 1236 case HCI_EVENT_PACKET: 1237 l2cap_event_handler(packet, size); 1238 break; 1239 case HCI_ACL_DATA_PACKET: 1240 l2cap_acl_handler(packet, size); 1241 break; 1242 default: 1243 break; 1244 } 1245 l2cap_run(); 1246 } 1247 1248 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1249 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1250 channel->state = L2CAP_STATE_CLOSED; 1251 l2cap_emit_channel_closed(channel); 1252 // discard channel 1253 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1254 btstack_memory_l2cap_channel_free(channel); 1255 } 1256 1257 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1258 linked_item_t *it; 1259 1260 // close open channels 1261 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 1262 l2cap_service_t * service = ((l2cap_service_t *) it); 1263 if ( service->psm == psm){ 1264 return service; 1265 }; 1266 } 1267 return NULL; 1268 } 1269 1270 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){ 1271 1272 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1273 1274 // check for alread registered psm 1275 // TODO: emit error event 1276 l2cap_service_t *service = l2cap_get_service(psm); 1277 if (service) { 1278 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 1279 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1280 return; 1281 } 1282 1283 // alloc structure 1284 // TODO: emit error event 1285 service = (l2cap_service_t *) btstack_memory_l2cap_service_get(); 1286 if (!service) { 1287 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 1288 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1289 return; 1290 } 1291 1292 // fill in 1293 service->psm = psm; 1294 service->mtu = mtu; 1295 service->connection = connection; 1296 service->packet_handler = packet_handler; 1297 service->required_security_level = security_level; 1298 1299 // add to services list 1300 linked_list_add(&l2cap_services, (linked_item_t *) service); 1301 1302 // enable page scan 1303 hci_connectable_control(1); 1304 1305 // done 1306 l2cap_emit_service_registered(connection, 0, psm); 1307 } 1308 1309 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1310 1311 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1312 1313 l2cap_service_t *service = l2cap_get_service(psm); 1314 if (!service) return; 1315 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1316 btstack_memory_l2cap_service_free(service); 1317 1318 // disable page scan when no services registered 1319 if (!linked_list_empty(&l2cap_services)) return; 1320 hci_connectable_control(0); 1321 } 1322 1323 // 1324 void l2cap_close_connection(void *connection){ 1325 linked_item_t *it; 1326 1327 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 1328 l2cap_channel_t * channel; 1329 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1330 channel = (l2cap_channel_t *) it; 1331 if (channel->connection == connection) { 1332 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1333 } 1334 } 1335 1336 // unregister services 1337 it = (linked_item_t *) &l2cap_services; 1338 while (it->next) { 1339 l2cap_service_t * service = (l2cap_service_t *) it->next; 1340 if (service->connection == connection){ 1341 it->next = it->next->next; 1342 btstack_memory_l2cap_service_free(service); 1343 } else { 1344 it = it->next; 1345 } 1346 } 1347 1348 // process 1349 l2cap_run(); 1350 } 1351 1352 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1353 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1354 switch(channel_id){ 1355 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1356 attribute_protocol_packet_handler = packet_handler; 1357 break; 1358 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1359 security_protocol_packet_handler = packet_handler; 1360 break; 1361 } 1362 } 1363 1364 #ifdef HAVE_BLE 1365 // Request LE connection parameter update 1366 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){ 1367 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 1368 log_info("l2cap_send_signaling_packet, cannot send\n"); 1369 return BTSTACK_ACL_BUFFERS_FULL; 1370 } 1371 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 1372 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 1373 uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); 1374 return hci_send_acl_packet(acl_buffer, len); 1375 } 1376 #endif 1377 1378