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 = NULL; 76 static linked_list_t l2cap_services = NULL; 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 = NULL; 81 static btstack_packet_handler_t security_protocol_packet_handler = NULL; 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; 100 101 // 102 // register callback with HCI 103 // 104 hci_register_packet_handler(&l2cap_packet_handler); 105 hci_connectable_control(0); // no services yet 106 } 107 108 109 /** Register L2CAP packet handlers */ 110 static void null_packet_handler(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 111 } 112 void l2cap_register_packet_handler(void (*handler)(void * connection, uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size)){ 113 packet_handler = handler; 114 } 115 116 // notify client/protocol handler 117 void l2cap_dispatch(l2cap_channel_t *channel, uint8_t type, uint8_t * data, uint16_t size){ 118 if (channel->packet_handler) { 119 (* (channel->packet_handler))(type, channel->local_cid, data, size); 120 } else { 121 (*packet_handler)(channel->connection, type, channel->local_cid, data, size); 122 } 123 } 124 125 void l2cap_emit_channel_opened(l2cap_channel_t *channel, uint8_t status) { 126 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", 127 status, bd_addr_to_str(channel->address), channel->handle, channel->psm, 128 channel->local_cid, channel->remote_cid, channel->local_mtu, channel->remote_mtu, channel->flush_timeout); 129 uint8_t event[23]; 130 event[0] = L2CAP_EVENT_CHANNEL_OPENED; 131 event[1] = sizeof(event) - 2; 132 event[2] = status; 133 bt_flip_addr(&event[3], channel->address); 134 bt_store_16(event, 9, channel->handle); 135 bt_store_16(event, 11, channel->psm); 136 bt_store_16(event, 13, channel->local_cid); 137 bt_store_16(event, 15, channel->remote_cid); 138 bt_store_16(event, 17, channel->local_mtu); 139 bt_store_16(event, 19, channel->remote_mtu); 140 bt_store_16(event, 19, channel->flush_timeout); 141 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 142 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 143 } 144 145 void l2cap_emit_channel_closed(l2cap_channel_t *channel) { 146 log_info("L2CAP_EVENT_CHANNEL_CLOSED local_cid 0x%x", channel->local_cid); 147 uint8_t event[4]; 148 event[0] = L2CAP_EVENT_CHANNEL_CLOSED; 149 event[1] = sizeof(event) - 2; 150 bt_store_16(event, 2, channel->local_cid); 151 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 152 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 153 } 154 155 void l2cap_emit_connection_request(l2cap_channel_t *channel) { 156 log_info("L2CAP_EVENT_INCOMING_CONNECTION addr %s handle 0x%x psm 0x%x local_cid 0x%x remote_cid 0x%x", 157 bd_addr_to_str(channel->address), channel->handle, channel->psm, channel->local_cid, channel->remote_cid); 158 uint8_t event[16]; 159 event[0] = L2CAP_EVENT_INCOMING_CONNECTION; 160 event[1] = sizeof(event) - 2; 161 bt_flip_addr(&event[2], channel->address); 162 bt_store_16(event, 8, channel->handle); 163 bt_store_16(event, 10, channel->psm); 164 bt_store_16(event, 12, channel->local_cid); 165 bt_store_16(event, 14, channel->remote_cid); 166 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 167 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 168 } 169 170 static void l2cap_emit_service_registered(void *connection, uint8_t status, uint16_t psm){ 171 log_info("L2CAP_EVENT_SERVICE_REGISTERED status 0x%x psm 0x%x", status, psm); 172 uint8_t event[5]; 173 event[0] = L2CAP_EVENT_SERVICE_REGISTERED; 174 event[1] = sizeof(event) - 2; 175 event[2] = status; 176 bt_store_16(event, 3, psm); 177 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 178 (*packet_handler)(connection, HCI_EVENT_PACKET, 0, event, sizeof(event)); 179 } 180 181 void l2cap_emit_credits(l2cap_channel_t *channel, uint8_t credits) { 182 183 log_info("L2CAP_EVENT_CREDITS local_cid 0x%x credits %u", channel->local_cid, credits); 184 // track credits 185 channel->packets_granted += credits; 186 187 uint8_t event[5]; 188 event[0] = L2CAP_EVENT_CREDITS; 189 event[1] = sizeof(event) - 2; 190 bt_store_16(event, 2, channel->local_cid); 191 event[4] = credits; 192 hci_dump_packet( HCI_EVENT_PACKET, 0, event, sizeof(event)); 193 l2cap_dispatch(channel, HCI_EVENT_PACKET, event, sizeof(event)); 194 } 195 196 void l2cap_block_new_credits(uint8_t blocked){ 197 new_credits_blocked = blocked; 198 } 199 200 void l2cap_hand_out_credits(void){ 201 202 if (new_credits_blocked) return; // we're told not to. used by daemon 203 204 linked_item_t *it; 205 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 206 if (!hci_number_free_acl_slots()) return; 207 l2cap_channel_t * channel = (l2cap_channel_t *) it; 208 if (channel->state != L2CAP_STATE_OPEN) continue; 209 if (hci_number_outgoing_packets(channel->handle) < NR_BUFFERED_ACL_PACKETS && channel->packets_granted == 0) { 210 l2cap_emit_credits(channel, 1); 211 } 212 } 213 } 214 215 l2cap_channel_t * l2cap_get_channel_for_local_cid(uint16_t local_cid){ 216 linked_item_t *it; 217 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 218 l2cap_channel_t * channel = (l2cap_channel_t *) it; 219 if ( channel->local_cid == local_cid) { 220 return channel; 221 } 222 } 223 return NULL; 224 } 225 226 int l2cap_can_send_packet_now(uint16_t local_cid){ 227 l2cap_channel_t *channel = l2cap_get_channel_for_local_cid(local_cid); 228 if (!channel) return 0; 229 if (!channel->packets_granted) return 0; 230 return hci_can_send_packet_now(HCI_ACL_DATA_PACKET); 231 } 232 233 uint16_t l2cap_get_remote_mtu_for_local_cid(uint16_t local_cid){ 234 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 235 if (channel) { 236 return channel->remote_mtu; 237 } 238 return 0; 239 } 240 241 static l2cap_channel_t * l2cap_channel_for_rtx_timer(timer_source_t * ts){ 242 linked_item_t *it; 243 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 244 l2cap_channel_t * channel = (l2cap_channel_t *) it; 245 if ( &channel->rtx == ts) { 246 return channel; 247 } 248 } 249 return NULL; 250 } 251 252 static void l2cap_rtx_timeout(timer_source_t * ts){ 253 l2cap_channel_t * channel = l2cap_channel_for_rtx_timer(ts); 254 if (!ts) return; 255 256 log_info("l2cap_rtx_timeout for local cid 0x%02x", channel->local_cid); 257 258 // "When terminating the channel, it is not necessary to send a L2CAP_DisconnectReq 259 // and enter WAIT_DISCONNECT state. Channels can be transitioned directly to the CLOSED state." 260 // notify client 261 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_RTX_TIMEOUT); 262 263 // discard channel 264 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 265 btstack_memory_l2cap_channel_free(channel); 266 } 267 268 static void l2cap_stop_rtx(l2cap_channel_t * channel){ 269 log_info("l2cap_stop_rtx for local cid 0x%02x", channel->local_cid); 270 run_loop_remove_timer(&channel->rtx); 271 } 272 273 static void l2cap_start_rtx(l2cap_channel_t * channel){ 274 log_info("l2cap_start_rtx for local cid 0x%02x", channel->local_cid); 275 l2cap_stop_rtx(channel); 276 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 277 run_loop_set_timer(&channel->rtx, L2CAP_RTX_TIMEOUT_MS); 278 run_loop_add_timer(&channel->rtx); 279 } 280 281 static void l2cap_start_ertx(l2cap_channel_t * channel){ 282 log_info("l2cap_start_ertx for local cid 0x%02x", channel->local_cid); 283 l2cap_stop_rtx(channel); 284 run_loop_set_timer_handler(&channel->rtx, l2cap_rtx_timeout); 285 run_loop_set_timer(&channel->rtx, L2CAP_ERTX_TIMEOUT_MS); 286 run_loop_add_timer(&channel->rtx); 287 } 288 289 static int l2cap_security_level_0_allowed_for_PSM(uint16_t psm){ 290 return psm != PSM_SDP; 291 } 292 293 int l2cap_send_signaling_packet(hci_con_handle_t handle, L2CAP_SIGNALING_COMMANDS cmd, uint8_t identifier, ...){ 294 295 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 296 log_info("l2cap_send_signaling_packet, cannot send\n"); 297 return BTSTACK_ACL_BUFFERS_FULL; 298 } 299 300 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 301 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 302 va_list argptr; 303 va_start(argptr, identifier); 304 uint16_t len = l2cap_create_signaling_internal(acl_buffer, handle, cmd, identifier, argptr); 305 va_end(argptr); 306 // log_info("l2cap_send_signaling_packet con %u!\n", handle); 307 return hci_send_acl_packet(acl_buffer, len); 308 } 309 310 uint8_t *l2cap_get_outgoing_buffer(void){ 311 return hci_get_outgoing_acl_packet_buffer() + COMPLETE_L2CAP_HEADER; // 8 bytes 312 } 313 314 int l2cap_send_prepared(uint16_t local_cid, uint16_t len){ 315 316 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 317 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", local_cid); 318 return BTSTACK_ACL_BUFFERS_FULL; 319 } 320 321 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 322 if (!channel) { 323 log_error("l2cap_send_internal no channel for cid 0x%02x\n", local_cid); 324 return -1; // TODO: define error 325 } 326 327 if (channel->packets_granted == 0){ 328 log_error("l2cap_send_internal cid 0x%02x, no credits!\n", local_cid); 329 return -1; // TODO: define error 330 } 331 332 --channel->packets_granted; 333 334 log_debug("l2cap_send_internal cid 0x%02x, handle %u, 1 credit used, credits left %u;\n", 335 local_cid, channel->handle, channel->packets_granted); 336 337 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 338 339 // 0 - Connection handle : PB=10 : BC=00 340 bt_store_16(acl_buffer, 0, channel->handle | (2 << 12) | (0 << 14)); 341 // 2 - ACL length 342 bt_store_16(acl_buffer, 2, len + 4); 343 // 4 - L2CAP packet length 344 bt_store_16(acl_buffer, 4, len + 0); 345 // 6 - L2CAP channel DEST 346 bt_store_16(acl_buffer, 6, channel->remote_cid); 347 // send 348 int err = hci_send_acl_packet(acl_buffer, len+8); 349 350 l2cap_hand_out_credits(); 351 352 return err; 353 } 354 355 int l2cap_send_prepared_connectionless(uint16_t handle, uint16_t cid, uint16_t len){ 356 357 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 358 log_info("l2cap_send_prepared_to_handle cid 0x%02x, cannot send\n", cid); 359 return BTSTACK_ACL_BUFFERS_FULL; 360 } 361 362 log_debug("l2cap_send_prepared_to_handle cid 0x%02x, handle %u\n", cid, handle); 363 364 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 365 366 // 0 - Connection handle : PB=10 : BC=00 367 bt_store_16(acl_buffer, 0, handle | (2 << 12) | (0 << 14)); 368 // 2 - ACL length 369 bt_store_16(acl_buffer, 2, len + 4); 370 // 4 - L2CAP packet length 371 bt_store_16(acl_buffer, 4, len + 0); 372 // 6 - L2CAP channel DEST 373 bt_store_16(acl_buffer, 6, cid); 374 // send 375 int err = hci_send_acl_packet(acl_buffer, len+8); 376 377 l2cap_hand_out_credits(); 378 379 return err; 380 } 381 382 int l2cap_send_internal(uint16_t local_cid, uint8_t *data, uint16_t len){ 383 384 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 385 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", local_cid); 386 return BTSTACK_ACL_BUFFERS_FULL; 387 } 388 389 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 390 391 memcpy(&acl_buffer[8], data, len); 392 393 return l2cap_send_prepared(local_cid, len); 394 } 395 396 int l2cap_send_connectionless(uint16_t handle, uint16_t cid, uint8_t *data, uint16_t len){ 397 398 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 399 log_info("l2cap_send_internal cid 0x%02x, cannot send\n", cid); 400 return BTSTACK_ACL_BUFFERS_FULL; 401 } 402 403 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 404 405 memcpy(&acl_buffer[8], data, len); 406 407 return l2cap_send_prepared_connectionless(handle, cid, len); 408 } 409 410 static inline void channelStateVarSetFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 411 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var | flag); 412 } 413 414 static inline void channelStateVarClearFlag(l2cap_channel_t *channel, L2CAP_CHANNEL_STATE_VAR flag){ 415 channel->state_var = (L2CAP_CHANNEL_STATE_VAR) (channel->state_var & ~flag); 416 } 417 418 419 420 // MARK: L2CAP_RUN 421 // process outstanding signaling tasks 422 void l2cap_run(void){ 423 424 // check pending signaling responses 425 while (signaling_responses_pending){ 426 427 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)) break; 428 429 hci_con_handle_t handle = signaling_responses[0].handle; 430 uint8_t sig_id = signaling_responses[0].sig_id; 431 uint16_t infoType = signaling_responses[0].data; // INFORMATION_REQUEST 432 uint16_t result = signaling_responses[0].data; // CONNECTION_REQUEST, COMMAND_REJECT 433 434 switch (signaling_responses[0].code){ 435 case CONNECTION_REQUEST: 436 l2cap_send_signaling_packet(handle, CONNECTION_RESPONSE, sig_id, 0, 0, result, 0); 437 // also disconnect if result is 0x0003 - security blocked 438 hci_disconnect_security_block(handle); 439 break; 440 case ECHO_REQUEST: 441 l2cap_send_signaling_packet(handle, ECHO_RESPONSE, sig_id, 0, NULL); 442 break; 443 case INFORMATION_REQUEST: 444 switch (infoType){ 445 case 1: { // Connectionless MTU 446 uint16_t connectionless_mtu = hci_max_acl_data_packet_length(); 447 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(connectionless_mtu), &connectionless_mtu); 448 break; 449 } 450 case 2: { // Extended Features Supported 451 // extended features request supported, only supporing fixed channel map 452 uint32_t features = 0x80; 453 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(features), &features); 454 break; 455 } 456 case 3: { // Fixed Channels Supported 457 uint8_t map[8]; 458 memset(map, 0, 8); 459 map[0] = 0x01; // L2CAP Signaling Channel 460 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 0, sizeof(map), &map); 461 break; 462 } 463 default: 464 // all other types are not supported 465 l2cap_send_signaling_packet(handle, INFORMATION_RESPONSE, sig_id, infoType, 1, 0, NULL); 466 break; 467 } 468 break; 469 case COMMAND_REJECT: 470 l2cap_send_signaling_packet(handle, COMMAND_REJECT, sig_id, result); 471 break; 472 default: 473 // should not happen 474 break; 475 } 476 477 // remove first item 478 signaling_responses_pending--; 479 int i; 480 for (i=0; i < signaling_responses_pending; i++){ 481 memcpy(&signaling_responses[i], &signaling_responses[i+1], sizeof(l2cap_signaling_response_t)); 482 } 483 } 484 485 uint8_t config_options[4]; 486 linked_item_t *it; 487 linked_item_t *next; 488 for (it = (linked_item_t *) l2cap_channels; it ; it = next){ 489 next = it->next; // cache next item as current item might get freed 490 491 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 492 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)) break; 493 494 l2cap_channel_t * channel = (l2cap_channel_t *) it; 495 496 // log_info("l2cap_run: state %u, var 0x%02x\n", channel->state, channel->state_var); 497 498 499 switch (channel->state){ 500 501 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 502 case L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT: 503 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND) { 504 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND); 505 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 1, 0); 506 } 507 break; 508 509 case L2CAP_STATE_WILL_SEND_CREATE_CONNECTION: 510 // send connection request - set state first 511 channel->state = L2CAP_STATE_WAIT_CONNECTION_COMPLETE; 512 // BD_ADDR, Packet_Type, Page_Scan_Repetition_Mode, Reserved, Clock_Offset, Allow_Role_Switch 513 hci_send_cmd(&hci_create_connection, channel->address, hci_usable_acl_packet_types(), 0, 0, 0, 1); 514 break; 515 516 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE: 517 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, channel->reason, 0); 518 // discard channel - l2cap_finialize_channel_close without sending l2cap close event 519 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); // -- remove from list 520 btstack_memory_l2cap_channel_free(channel); 521 break; 522 523 case L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT: 524 channel->state = L2CAP_STATE_CONFIG; 525 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 526 l2cap_send_signaling_packet(channel->handle, CONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid, 0, 0); 527 break; 528 529 case L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST: 530 // success, start l2cap handshake 531 channel->local_sig_id = l2cap_next_sig_id(); 532 channel->state = L2CAP_STATE_WAIT_CONNECT_RSP; 533 l2cap_send_signaling_packet( channel->handle, CONNECTION_REQUEST, channel->local_sig_id, channel->psm, channel->local_cid); 534 l2cap_start_rtx(channel); 535 break; 536 537 case L2CAP_STATE_CONFIG: 538 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP){ 539 uint16_t flags = 0; 540 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 541 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT) { 542 flags = 1; 543 } else { 544 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP); 545 } 546 if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID){ 547 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, L2CAP_CONF_RESULT_UNKNOWN_OPTIONS, 0, NULL); 548 } else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU){ 549 config_options[0] = 1; // MTU 550 config_options[1] = 2; // len param 551 bt_store_16( (uint8_t*)&config_options, 2, channel->remote_mtu); 552 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 4, &config_options); 553 channelStateVarClearFlag(channel,L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 554 } else { 555 l2cap_send_signaling_packet(channel->handle, CONFIGURE_RESPONSE, channel->remote_sig_id, channel->remote_cid, flags, 0, 0, NULL); 556 } 557 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 558 } 559 else if (channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ){ 560 channelStateVarClearFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 561 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SENT_CONF_REQ); 562 channel->local_sig_id = l2cap_next_sig_id(); 563 config_options[0] = 1; // MTU 564 config_options[1] = 2; // len param 565 bt_store_16( (uint8_t*)&config_options, 2, channel->local_mtu); 566 l2cap_send_signaling_packet(channel->handle, CONFIGURE_REQUEST, channel->local_sig_id, channel->remote_cid, 0, 4, &config_options); 567 l2cap_start_rtx(channel); 568 } 569 if (l2cap_channel_ready_for_open(channel)){ 570 channel->state = L2CAP_STATE_OPEN; 571 l2cap_emit_channel_opened(channel, 0); // success 572 l2cap_emit_credits(channel, 1); 573 } 574 break; 575 576 case L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE: 577 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_RESPONSE, channel->remote_sig_id, channel->local_cid, channel->remote_cid); 578 // 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 :) 579 l2cap_finialize_channel_close(channel); // -- remove from list 580 break; 581 582 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 583 channel->local_sig_id = l2cap_next_sig_id(); 584 channel->state = L2CAP_STATE_WAIT_DISCONNECT; 585 l2cap_send_signaling_packet( channel->handle, DISCONNECTION_REQUEST, channel->local_sig_id, channel->remote_cid, channel->local_cid); 586 break; 587 default: 588 break; 589 } 590 } 591 } 592 593 uint16_t l2cap_max_mtu(void){ 594 return hci_max_acl_data_packet_length() - L2CAP_HEADER_SIZE; 595 } 596 597 // open outgoing L2CAP channel 598 void l2cap_create_channel_internal(void * connection, btstack_packet_handler_t packet_handler, 599 bd_addr_t address, uint16_t psm, uint16_t mtu){ 600 601 log_info("L2CAP_CREATE_CHANNEL_MTU addr %s psm 0x%x mtu %u", bd_addr_to_str(address), psm, mtu); 602 603 // alloc structure 604 l2cap_channel_t * chan = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 605 if (!chan) { 606 // emit error event 607 l2cap_channel_t dummy_channel; 608 BD_ADDR_COPY(dummy_channel.address, address); 609 dummy_channel.psm = psm; 610 l2cap_emit_channel_opened(&dummy_channel, BTSTACK_MEMORY_ALLOC_FAILED); 611 return; 612 } 613 // limit local mtu to max acl packet length 614 if (mtu > l2cap_max_mtu()) { 615 mtu = l2cap_max_mtu(); 616 } 617 618 // fill in 619 BD_ADDR_COPY(chan->address, address); 620 chan->psm = psm; 621 chan->handle = 0; 622 chan->connection = connection; 623 chan->packet_handler = packet_handler; 624 chan->remote_mtu = L2CAP_MINIMAL_MTU; 625 chan->local_mtu = mtu; 626 chan->packets_granted = 0; 627 628 // set initial state 629 chan->state = L2CAP_STATE_WILL_SEND_CREATE_CONNECTION; 630 chan->state_var = L2CAP_CHANNEL_STATE_VAR_NONE; 631 chan->remote_sig_id = L2CAP_SIG_ID_INVALID; 632 chan->local_sig_id = L2CAP_SIG_ID_INVALID; 633 634 // add to connections list 635 linked_list_add(&l2cap_channels, (linked_item_t *) chan); 636 637 l2cap_run(); 638 } 639 640 void l2cap_disconnect_internal(uint16_t local_cid, uint8_t reason){ 641 log_info("L2CAP_DISCONNECT local_cid 0x%x reason 0x%x", local_cid, reason); 642 // find channel for local_cid 643 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 644 if (channel) { 645 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 646 } 647 // process 648 l2cap_run(); 649 } 650 651 static void l2cap_handle_connection_failed_for_addr(bd_addr_t address, uint8_t status){ 652 linked_item_t *it = (linked_item_t *) &l2cap_channels; 653 while (it->next){ 654 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 655 if ( ! BD_ADDR_CMP( channel->address, address) ){ 656 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 657 // failure, forward error code 658 l2cap_emit_channel_opened(channel, status); 659 // discard channel 660 it->next = it->next->next; 661 btstack_memory_l2cap_channel_free(channel); 662 } 663 } else { 664 it = it->next; 665 } 666 } 667 } 668 669 static void l2cap_handle_connection_success_for_addr(bd_addr_t address, hci_con_handle_t handle){ 670 linked_item_t *it; 671 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 672 l2cap_channel_t * channel = (l2cap_channel_t *) it; 673 if ( ! BD_ADDR_CMP( channel->address, address) ){ 674 if (channel->state == L2CAP_STATE_WAIT_CONNECTION_COMPLETE || channel->state == L2CAP_STATE_WILL_SEND_CREATE_CONNECTION) { 675 // success, start l2cap handshake 676 channel->handle = handle; 677 channel->local_cid = l2cap_next_local_cid(); 678 // check remote SSP feature first 679 channel->state = L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES; 680 } 681 } 682 } 683 // process 684 l2cap_run(); 685 } 686 687 void l2cap_event_handler( uint8_t *packet, uint16_t size ){ 688 689 bd_addr_t address; 690 hci_con_handle_t handle; 691 l2cap_channel_t * channel; 692 linked_item_t *it; 693 int hci_con_used; 694 695 switch(packet[0]){ 696 697 // handle connection complete events 698 case HCI_EVENT_CONNECTION_COMPLETE: 699 bt_flip_addr(address, &packet[5]); 700 if (packet[2] == 0){ 701 handle = READ_BT_16(packet, 3); 702 l2cap_handle_connection_success_for_addr(address, handle); 703 } else { 704 l2cap_handle_connection_failed_for_addr(address, packet[2]); 705 } 706 break; 707 708 // handle successful create connection cancel command 709 case HCI_EVENT_COMMAND_COMPLETE: 710 if ( COMMAND_COMPLETE_EVENT(packet, hci_create_connection_cancel) ) { 711 if (packet[5] == 0){ 712 bt_flip_addr(address, &packet[6]); 713 // CONNECTION TERMINATED BY LOCAL HOST (0X16) 714 l2cap_handle_connection_failed_for_addr(address, 0x16); 715 } 716 } 717 l2cap_run(); // try sending signaling packets first 718 break; 719 720 case HCI_EVENT_COMMAND_STATUS: 721 l2cap_run(); // try sending signaling packets first 722 break; 723 724 // handle disconnection complete events 725 case HCI_EVENT_DISCONNECTION_COMPLETE: 726 // send l2cap disconnect events for all channels on this handle 727 handle = READ_BT_16(packet, 3); 728 it = (linked_item_t *) &l2cap_channels; 729 while (it->next){ 730 l2cap_channel_t * channel = (l2cap_channel_t *) it->next; 731 if ( channel->handle == handle ){ 732 // update prev item before free'ing next element - don't call l2cap_finalize_channel_close 733 it->next = it->next->next; 734 l2cap_emit_channel_closed(channel); 735 btstack_memory_l2cap_channel_free(channel); 736 } else { 737 it = it->next; 738 } 739 } 740 break; 741 742 case HCI_EVENT_NUMBER_OF_COMPLETED_PACKETS: 743 l2cap_run(); // try sending signaling packets first 744 l2cap_hand_out_credits(); 745 break; 746 747 // HCI Connection Timeouts 748 case L2CAP_EVENT_TIMEOUT_CHECK: 749 handle = READ_BT_16(packet, 2); 750 if (hci_authentication_active_for_handle(handle)) break; 751 hci_con_used = 0; 752 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 753 channel = (l2cap_channel_t *) it; 754 if (channel->handle == handle) { 755 hci_con_used = 1; 756 } 757 } 758 if (hci_con_used) break; 759 if (!hci_can_send_packet_now(HCI_COMMAND_DATA_PACKET)) break; 760 hci_send_cmd(&hci_disconnect, handle, 0x13); // remote closed connection 761 break; 762 763 case DAEMON_EVENT_HCI_PACKET_SENT: 764 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 765 channel = (l2cap_channel_t *) it; 766 if (channel->packet_handler) { 767 (* (channel->packet_handler))(HCI_EVENT_PACKET, channel->local_cid, packet, size); 768 } 769 } 770 if (attribute_protocol_packet_handler) { 771 (*attribute_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 772 } 773 if (security_protocol_packet_handler) { 774 (*security_protocol_packet_handler)(HCI_EVENT_PACKET, 0, packet, size); 775 } 776 break; 777 778 case HCI_EVENT_READ_REMOTE_SUPPORTED_FEATURES_COMPLETE: 779 handle = READ_BT_16(packet, 3); 780 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 781 channel = (l2cap_channel_t *) it; 782 if (channel->handle != handle) continue; 783 if (channel->state != L2CAP_STATE_WAIT_REMOTE_SUPPORTED_FEATURES) continue; 784 // we have been waiting for remote supported features, if both support SSP, 785 if (hci_ssp_supported_on_both_sides(channel->handle) && !l2cap_security_level_0_allowed_for_PSM(channel->psm)){ 786 // request security level 2 787 gap_request_security_level(channel->handle, LEVEL_2); 788 channel->state = L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE; 789 break; 790 } 791 // fine, go ahead 792 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 793 break; 794 } 795 796 case GAP_SECURITY_LEVEL: 797 handle = READ_BT_16(packet, 2); 798 log_info("GAP_SECURITY_LEVEL"); 799 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 800 channel = (l2cap_channel_t *) it; 801 gap_security_level_t actual_level = packet[4]; 802 if (channel->handle != handle) continue; 803 switch (channel->state){ 804 case L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE: 805 log_info("gap incoming"); 806 if (actual_level >= channel->required_security_level){ 807 channel->state = L2CAP_STATE_WAIT_CLIENT_ACCEPT_OR_REJECT; 808 l2cap_emit_connection_request(channel); 809 } else { 810 channel->reason = 0x03; // security block 811 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 812 } 813 break; 814 815 case L2CAP_STATE_WAIT_OUTGOING_SECURITY_LEVEL_UPDATE: 816 log_info("gap outgoing"); 817 if (actual_level >= channel->required_security_level){ 818 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_REQUEST; 819 } else { 820 // disconnnect, authentication not good enough 821 hci_disconnect_security_block(handle); 822 } 823 break; 824 825 default: 826 break; 827 } 828 } 829 break; 830 831 default: 832 break; 833 } 834 835 // pass on 836 (*packet_handler)(NULL, HCI_EVENT_PACKET, 0, packet, size); 837 } 838 839 static void l2cap_handle_disconnect_request(l2cap_channel_t *channel, uint16_t identifier){ 840 channel->remote_sig_id = identifier; 841 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_RESPONSE; 842 l2cap_run(); 843 } 844 845 static void l2cap_register_signaling_response(hci_con_handle_t handle, uint8_t code, uint8_t sig_id, uint16_t data){ 846 // Vol 3, Part A, 4.3: "The DCID and SCID fields shall be ignored when the result field indi- cates the connection was refused." 847 if (signaling_responses_pending < NR_PENDING_SIGNALING_RESPONSES) { 848 signaling_responses[signaling_responses_pending].handle = handle; 849 signaling_responses[signaling_responses_pending].code = code; 850 signaling_responses[signaling_responses_pending].sig_id = sig_id; 851 signaling_responses[signaling_responses_pending].data = data; 852 signaling_responses_pending++; 853 l2cap_run(); 854 } 855 } 856 857 static void l2cap_handle_connection_request(hci_con_handle_t handle, uint8_t sig_id, uint16_t psm, uint16_t source_cid){ 858 859 // log_info("l2cap_handle_connection_request for handle %u, psm %u cid 0x%02x\n", handle, psm, source_cid); 860 l2cap_service_t *service = l2cap_get_service(psm); 861 if (!service) { 862 // 0x0002 PSM not supported 863 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0002); 864 return; 865 } 866 867 hci_connection_t * hci_connection = hci_connection_for_handle( handle ); 868 if (!hci_connection) { 869 // 870 log_error("no hci_connection for handle %u\n", handle); 871 return; 872 } 873 874 // reject connection (0x03 security block) and disconnect if both have SSP, connection is not encrypted and PSM != SDP 875 if ( l2cap_security_level_0_allowed_for_PSM(psm) 876 && hci_ssp_supported_on_both_sides(handle) 877 && gap_security_level(handle) == LEVEL_0){ 878 879 // 0x0003 Security Block 880 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0003); 881 return; 882 } 883 884 885 // alloc structure 886 // log_info("l2cap_handle_connection_request register channel\n"); 887 l2cap_channel_t * channel = (l2cap_channel_t*) btstack_memory_l2cap_channel_get(); 888 if (!channel){ 889 // 0x0004 No resources available 890 l2cap_register_signaling_response(handle, CONNECTION_REQUEST, sig_id, 0x0004); 891 return; 892 } 893 894 // fill in 895 BD_ADDR_COPY(channel->address, hci_connection->address); 896 channel->psm = psm; 897 channel->handle = handle; 898 channel->connection = service->connection; 899 channel->packet_handler = service->packet_handler; 900 channel->local_cid = l2cap_next_local_cid(); 901 channel->remote_cid = source_cid; 902 channel->local_mtu = service->mtu; 903 channel->remote_mtu = L2CAP_DEFAULT_MTU; 904 channel->packets_granted = 0; 905 channel->remote_sig_id = sig_id; 906 channel->required_security_level = service->required_security_level; 907 908 // limit local mtu to max acl packet length 909 if (channel->local_mtu > l2cap_max_mtu()) { 910 channel->local_mtu = l2cap_max_mtu(); 911 } 912 913 // set initial state 914 channel->state = L2CAP_STATE_WAIT_INCOMING_SECURITY_LEVEL_UPDATE; 915 channel->state_var = L2CAP_CHANNEL_STATE_VAR_SEND_CONN_RESP_PEND; 916 917 // add to connections list 918 linked_list_add(&l2cap_channels, (linked_item_t *) channel); 919 920 // assert security requirements 921 gap_request_security_level(handle, channel->required_security_level); 922 } 923 924 void l2cap_accept_connection_internal(uint16_t local_cid){ 925 log_info("L2CAP_ACCEPT_CONNECTION local_cid 0x%x", local_cid); 926 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(local_cid); 927 if (!channel) { 928 log_error("l2cap_accept_connection_internal called but local_cid 0x%x not found", local_cid); 929 return; 930 } 931 932 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_ACCEPT; 933 934 // process 935 l2cap_run(); 936 } 937 938 void l2cap_decline_connection_internal(uint16_t local_cid, uint8_t reason){ 939 log_info("L2CAP_DECLINE_CONNECTION local_cid 0x%x, reason %x", local_cid, reason); 940 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid( local_cid); 941 if (!channel) { 942 log_error( "l2cap_decline_connection_internal called but local_cid 0x%x not found", local_cid); 943 return; 944 } 945 channel->state = L2CAP_STATE_WILL_SEND_CONNECTION_RESPONSE_DECLINE; 946 channel->reason = reason; 947 l2cap_run(); 948 } 949 950 void l2cap_signaling_handle_configure_request(l2cap_channel_t *channel, uint8_t *command){ 951 952 channel->remote_sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 953 954 uint16_t flags = READ_BT_16(command, 6); 955 if (flags & 1) { 956 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT); 957 } 958 959 // accept the other's configuration options 960 uint16_t end_pos = 4 + READ_BT_16(command, L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 961 uint16_t pos = 8; 962 while (pos < end_pos){ 963 uint8_t option_hint = command[pos] >> 7; 964 uint8_t option_type = command[pos] & 0x7f; 965 log_info("l2cap cid %u, hint %u, type %u", channel->local_cid, option_hint, option_type); 966 pos++; 967 uint8_t length = command[pos++]; 968 // MTU { type(8): 1, len(8):2, MTU(16) } 969 if (option_type == 1 && length == 2){ 970 channel->remote_mtu = READ_BT_16(command, pos); 971 // log_info("l2cap cid 0x%02x, remote mtu %u\n", channel->local_cid, channel->remote_mtu); 972 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_MTU); 973 } 974 // Flush timeout { type(8):2, len(8): 2, Flush Timeout(16)} 975 if (option_type == 2 && length == 2){ 976 channel->flush_timeout = READ_BT_16(command, pos); 977 } 978 // check for unknown options 979 if (option_hint == 0 && (option_type == 0 || option_type >= 0x07)){ 980 log_info("l2cap cid %u, unknown options", channel->local_cid); 981 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_INVALID); 982 } 983 pos += length; 984 } 985 } 986 987 static int l2cap_channel_ready_for_open(l2cap_channel_t *channel){ 988 // log_info("l2cap_channel_ready_for_open 0x%02x\n", channel->state_var); 989 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP) == 0) return 0; 990 if ((channel->state_var & L2CAP_CHANNEL_STATE_VAR_SENT_CONF_RSP) == 0) return 0; 991 return 1; 992 } 993 994 995 void l2cap_signaling_handler_channel(l2cap_channel_t *channel, uint8_t *command){ 996 997 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 998 uint8_t identifier = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 999 uint16_t result = 0; 1000 1001 log_info("L2CAP signaling handler code %u, state %u\n", code, channel->state); 1002 1003 // handle DISCONNECT REQUESTS seperately 1004 if (code == DISCONNECTION_REQUEST){ 1005 switch (channel->state){ 1006 case L2CAP_STATE_CONFIG: 1007 case L2CAP_STATE_OPEN: 1008 case L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST: 1009 case L2CAP_STATE_WAIT_DISCONNECT: 1010 l2cap_handle_disconnect_request(channel, identifier); 1011 break; 1012 1013 default: 1014 // ignore in other states 1015 break; 1016 } 1017 return; 1018 } 1019 1020 // @STATEMACHINE(l2cap) 1021 switch (channel->state) { 1022 1023 case L2CAP_STATE_WAIT_CONNECT_RSP: 1024 switch (code){ 1025 case CONNECTION_RESPONSE: 1026 l2cap_stop_rtx(channel); 1027 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1028 switch (result) { 1029 case 0: 1030 // successful connection 1031 channel->remote_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1032 channel->state = L2CAP_STATE_CONFIG; 1033 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1034 break; 1035 case 1: 1036 // connection pending. get some coffee, but start the ERTX 1037 l2cap_start_ertx(channel); 1038 break; 1039 default: 1040 // channel closed 1041 channel->state = L2CAP_STATE_CLOSED; 1042 // map l2cap connection response result to BTstack status enumeration 1043 l2cap_emit_channel_opened(channel, L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result); 1044 1045 // drop link key if security block 1046 if (L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL + result == L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY){ 1047 hci_drop_link_key_for_bd_addr(&channel->address); 1048 } 1049 1050 // discard channel 1051 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1052 btstack_memory_l2cap_channel_free(channel); 1053 break; 1054 } 1055 break; 1056 1057 default: 1058 //@TODO: implement other signaling packets 1059 break; 1060 } 1061 break; 1062 1063 case L2CAP_STATE_CONFIG: 1064 result = READ_BT_16 (command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+4); 1065 switch (code) { 1066 case CONFIGURE_REQUEST: 1067 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP); 1068 l2cap_signaling_handle_configure_request(channel, command); 1069 if (!(channel->state_var & L2CAP_CHANNEL_STATE_VAR_SEND_CONF_RSP_CONT)){ 1070 // only done if continuation not set 1071 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_REQ); 1072 } 1073 break; 1074 case CONFIGURE_RESPONSE: 1075 l2cap_stop_rtx(channel); 1076 switch (result){ 1077 case 0: // success 1078 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_RCVD_CONF_RSP); 1079 break; 1080 case 4: // pending 1081 l2cap_start_ertx(channel); 1082 break; 1083 default: 1084 // retry on negative result 1085 channelStateVarSetFlag(channel, L2CAP_CHANNEL_STATE_VAR_SEND_CONF_REQ); 1086 break; 1087 } 1088 break; 1089 default: 1090 break; 1091 } 1092 if (l2cap_channel_ready_for_open(channel)){ 1093 // for open: 1094 channel->state = L2CAP_STATE_OPEN; 1095 l2cap_emit_channel_opened(channel, 0); 1096 l2cap_emit_credits(channel, 1); 1097 } 1098 break; 1099 1100 case L2CAP_STATE_WAIT_DISCONNECT: 1101 switch (code) { 1102 case DISCONNECTION_RESPONSE: 1103 l2cap_finialize_channel_close(channel); 1104 break; 1105 default: 1106 //@TODO: implement other signaling packets 1107 break; 1108 } 1109 break; 1110 1111 case L2CAP_STATE_CLOSED: 1112 // @TODO handle incoming requests 1113 break; 1114 1115 case L2CAP_STATE_OPEN: 1116 //@TODO: implement other signaling packets, e.g. re-configure 1117 break; 1118 default: 1119 break; 1120 } 1121 // log_info("new state %u\n", channel->state); 1122 } 1123 1124 1125 void l2cap_signaling_handler_dispatch( hci_con_handle_t handle, uint8_t * command){ 1126 1127 // get code, signalind identifier and command len 1128 uint8_t code = command[L2CAP_SIGNALING_COMMAND_CODE_OFFSET]; 1129 uint8_t sig_id = command[L2CAP_SIGNALING_COMMAND_SIGID_OFFSET]; 1130 1131 // not for a particular channel, and not CONNECTION_REQUEST, ECHO_[REQUEST|RESPONSE], INFORMATION_REQUEST 1132 if (code < 1 || code == ECHO_RESPONSE || code > INFORMATION_REQUEST){ 1133 l2cap_register_signaling_response(handle, COMMAND_REJECT, sig_id, L2CAP_REJ_CMD_UNKNOWN); 1134 return; 1135 } 1136 1137 // general commands without an assigned channel 1138 switch(code) { 1139 1140 case CONNECTION_REQUEST: { 1141 uint16_t psm = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1142 uint16_t source_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET+2); 1143 l2cap_handle_connection_request(handle, sig_id, psm, source_cid); 1144 return; 1145 } 1146 1147 case ECHO_REQUEST: 1148 l2cap_register_signaling_response(handle, code, sig_id, 0); 1149 return; 1150 1151 case INFORMATION_REQUEST: { 1152 uint16_t infoType = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1153 l2cap_register_signaling_response(handle, code, sig_id, infoType); 1154 return; 1155 } 1156 1157 default: 1158 break; 1159 } 1160 1161 1162 // Get potential destination CID 1163 uint16_t dest_cid = READ_BT_16(command, L2CAP_SIGNALING_COMMAND_DATA_OFFSET); 1164 1165 // Find channel for this sig_id and connection handle 1166 linked_item_t *it; 1167 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1168 l2cap_channel_t * channel = (l2cap_channel_t *) it; 1169 if (channel->handle == handle) { 1170 if (code & 1) { 1171 // match odd commands (responses) by previous signaling identifier 1172 if (channel->local_sig_id == sig_id) { 1173 l2cap_signaling_handler_channel(channel, command); 1174 break; 1175 } 1176 } else { 1177 // match even commands (requests) by local channel id 1178 if (channel->local_cid == dest_cid) { 1179 l2cap_signaling_handler_channel(channel, command); 1180 break; 1181 } 1182 } 1183 } 1184 } 1185 } 1186 1187 void l2cap_acl_handler( uint8_t *packet, uint16_t size ){ 1188 1189 // Get Channel ID 1190 uint16_t channel_id = READ_L2CAP_CHANNEL_ID(packet); 1191 hci_con_handle_t handle = READ_ACL_CONNECTION_HANDLE(packet); 1192 1193 switch (channel_id) { 1194 1195 case L2CAP_CID_SIGNALING: { 1196 1197 uint16_t command_offset = 8; 1198 while (command_offset < size) { 1199 1200 // handle signaling commands 1201 l2cap_signaling_handler_dispatch(handle, &packet[command_offset]); 1202 1203 // increment command_offset 1204 command_offset += L2CAP_SIGNALING_COMMAND_DATA_OFFSET + READ_BT_16(packet, command_offset + L2CAP_SIGNALING_COMMAND_LENGTH_OFFSET); 1205 } 1206 break; 1207 } 1208 1209 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1210 if (attribute_protocol_packet_handler) { 1211 (*attribute_protocol_packet_handler)(ATT_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1212 } 1213 break; 1214 1215 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1216 if (security_protocol_packet_handler) { 1217 (*security_protocol_packet_handler)(SM_DATA_PACKET, handle, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1218 } 1219 break; 1220 1221 default: { 1222 // Find channel for this channel_id and connection handle 1223 l2cap_channel_t * channel = l2cap_get_channel_for_local_cid(channel_id); 1224 if (channel) { 1225 l2cap_dispatch(channel, L2CAP_DATA_PACKET, &packet[COMPLETE_L2CAP_HEADER], size-COMPLETE_L2CAP_HEADER); 1226 } 1227 break; 1228 } 1229 } 1230 } 1231 1232 static void l2cap_packet_handler(uint8_t packet_type, uint8_t *packet, uint16_t size){ 1233 switch (packet_type) { 1234 case HCI_EVENT_PACKET: 1235 l2cap_event_handler(packet, size); 1236 break; 1237 case HCI_ACL_DATA_PACKET: 1238 l2cap_acl_handler(packet, size); 1239 break; 1240 default: 1241 break; 1242 } 1243 l2cap_run(); 1244 } 1245 1246 // finalize closed channel - l2cap_handle_disconnect_request & DISCONNECTION_RESPONSE 1247 void l2cap_finialize_channel_close(l2cap_channel_t *channel){ 1248 channel->state = L2CAP_STATE_CLOSED; 1249 l2cap_emit_channel_closed(channel); 1250 // discard channel 1251 linked_list_remove(&l2cap_channels, (linked_item_t *) channel); 1252 btstack_memory_l2cap_channel_free(channel); 1253 } 1254 1255 l2cap_service_t * l2cap_get_service(uint16_t psm){ 1256 linked_item_t *it; 1257 1258 // close open channels 1259 for (it = (linked_item_t *) l2cap_services; it ; it = it->next){ 1260 l2cap_service_t * service = ((l2cap_service_t *) it); 1261 if ( service->psm == psm){ 1262 return service; 1263 }; 1264 } 1265 return NULL; 1266 } 1267 1268 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){ 1269 1270 log_info("L2CAP_REGISTER_SERVICE psm 0x%x mtu %u", psm, mtu); 1271 1272 // check for alread registered psm 1273 // TODO: emit error event 1274 l2cap_service_t *service = l2cap_get_service(psm); 1275 if (service) { 1276 log_error("l2cap_register_service_internal: PSM %u already registered\n", psm); 1277 l2cap_emit_service_registered(connection, L2CAP_SERVICE_ALREADY_REGISTERED, psm); 1278 return; 1279 } 1280 1281 // alloc structure 1282 // TODO: emit error event 1283 service = (l2cap_service_t *) btstack_memory_l2cap_service_get(); 1284 if (!service) { 1285 log_error("l2cap_register_service_internal: no memory for l2cap_service_t\n"); 1286 l2cap_emit_service_registered(connection, BTSTACK_MEMORY_ALLOC_FAILED, psm); 1287 return; 1288 } 1289 1290 // fill in 1291 service->psm = psm; 1292 service->mtu = mtu; 1293 service->connection = connection; 1294 service->packet_handler = packet_handler; 1295 service->required_security_level = security_level; 1296 1297 // add to services list 1298 linked_list_add(&l2cap_services, (linked_item_t *) service); 1299 1300 // enable page scan 1301 hci_connectable_control(1); 1302 1303 // done 1304 l2cap_emit_service_registered(connection, 0, psm); 1305 } 1306 1307 void l2cap_unregister_service_internal(void *connection, uint16_t psm){ 1308 1309 log_info("L2CAP_UNREGISTER_SERVICE psm 0x%x", psm); 1310 1311 l2cap_service_t *service = l2cap_get_service(psm); 1312 if (!service) return; 1313 linked_list_remove(&l2cap_services, (linked_item_t *) service); 1314 btstack_memory_l2cap_service_free(service); 1315 1316 // disable page scan when no services registered 1317 if (!linked_list_empty(&l2cap_services)) return; 1318 hci_connectable_control(0); 1319 } 1320 1321 // 1322 void l2cap_close_connection(void *connection){ 1323 linked_item_t *it; 1324 1325 // close open channels - note to myself: no channel is freed, so no new for fancy iterator tricks 1326 l2cap_channel_t * channel; 1327 for (it = (linked_item_t *) l2cap_channels; it ; it = it->next){ 1328 channel = (l2cap_channel_t *) it; 1329 if (channel->connection == connection) { 1330 channel->state = L2CAP_STATE_WILL_SEND_DISCONNECT_REQUEST; 1331 } 1332 } 1333 1334 // unregister services 1335 it = (linked_item_t *) &l2cap_services; 1336 while (it->next) { 1337 l2cap_service_t * service = (l2cap_service_t *) it->next; 1338 if (service->connection == connection){ 1339 it->next = it->next->next; 1340 btstack_memory_l2cap_service_free(service); 1341 } else { 1342 it = it->next; 1343 } 1344 } 1345 1346 // process 1347 l2cap_run(); 1348 } 1349 1350 // Bluetooth 4.0 - allows to register handler for Attribute Protocol and Security Manager Protocol 1351 void l2cap_register_fixed_channel(btstack_packet_handler_t packet_handler, uint16_t channel_id) { 1352 switch(channel_id){ 1353 case L2CAP_CID_ATTRIBUTE_PROTOCOL: 1354 attribute_protocol_packet_handler = packet_handler; 1355 break; 1356 case L2CAP_CID_SECURITY_MANAGER_PROTOCOL: 1357 security_protocol_packet_handler = packet_handler; 1358 break; 1359 } 1360 } 1361 1362 #ifdef HAVE_BLE 1363 // Request LE connection parameter update 1364 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){ 1365 if (!hci_can_send_packet_now(HCI_ACL_DATA_PACKET)){ 1366 log_info("l2cap_send_signaling_packet, cannot send\n"); 1367 return BTSTACK_ACL_BUFFERS_FULL; 1368 } 1369 // log_info("l2cap_send_signaling_packet type %u\n", cmd); 1370 uint8_t *acl_buffer = hci_get_outgoing_acl_packet_buffer(); 1371 uint16_t len = l2cap_le_create_connection_parameter_update_request(acl_buffer, handle, interval_min, interval_max, slave_latency, timeout_multiplier); 1372 return hci_send_acl_packet(acl_buffer, len); 1373 } 1374 #endif 1375 1376