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