1 /* 2 * Copyright (C) 2014 BlueKitchen GmbH 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 BLUEKITCHEN GMBH 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 34 * [email protected] 35 * 36 */ 37 38 #define __BTSTACK_FILE__ "goep_client.c" 39 40 #include "btstack_config.h" 41 42 #include <stdint.h> 43 #include <stdio.h> 44 #include <stdlib.h> 45 #include <string.h> 46 47 #include "btstack_debug.h" 48 #include "hci_dump.h" 49 #include "bluetooth_sdp.h" 50 #include "btstack_event.h" 51 #include "classic/goep_client.h" 52 #include "classic/obex.h" 53 #include "classic/obex_iterator.h" 54 #include "classic/rfcomm.h" 55 #include "classic/sdp_client.h" 56 #include "classic/sdp_util.h" 57 #include "l2cap.h" 58 59 //------------------------------------------------------------------------------------------------------------ 60 // goep_client.c 61 // 62 63 // #define ENABLE_GOEP_L2CAP 64 65 #ifdef ENABLE_GOEP_L2CAP 66 #ifndef ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE 67 #error "ENABLE_GOEP_L2CAP requires ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE. Please enable ENABLE_L2CAP_ENHANCED_RETRANSMISSION_MODE or disable ENABLE_GOEP_L2CAP" 68 #endif 69 #endif 70 71 typedef enum { 72 GOEP_INIT, 73 GOEP_W4_SDP, 74 GOEP_W4_CONNECTION, 75 GOEP_CONNECTED, 76 } goep_state_t; 77 78 typedef struct { 79 uint16_t cid; 80 goep_state_t state; 81 bd_addr_t bd_addr; 82 hci_con_handle_t con_handle; 83 uint8_t incoming; 84 uint8_t rfcomm_port; 85 uint16_t l2cap_psm; 86 uint16_t bearer_cid; 87 uint16_t bearer_mtu; 88 uint32_t pbap_supported_features; 89 90 uint8_t obex_opcode; 91 uint32_t obex_connection_id; 92 int obex_connection_id_set; 93 94 btstack_packet_handler_t client_handler; 95 } goep_client_t; 96 97 static goep_client_t _goep_client; 98 static goep_client_t * goep_client = &_goep_client; 99 100 static uint8_t attribute_value[30]; 101 static const unsigned int attribute_value_buffer_size = sizeof(attribute_value); 102 103 static uint8_t goep_packet_buffer[100]; 104 105 #ifdef ENABLE_GOEP_L2CAP 106 static uint8_t ertm_buffer[1000]; 107 static l2cap_ertm_config_t ertm_config = { 108 1, // ertm mandatory 109 2, // max transmit, some tests require > 1 110 2000, 111 12000, 112 512, // l2cap ertm mtu 113 2, 114 2, 115 0, // No FCS 116 }; 117 #endif 118 119 static inline void goep_client_emit_connected_event(goep_client_t * context, uint8_t status){ 120 uint8_t event[15]; 121 int pos = 0; 122 event[pos++] = HCI_EVENT_GOEP_META; 123 pos++; // skip len 124 event[pos++] = GOEP_SUBEVENT_CONNECTION_OPENED; 125 little_endian_store_16(event,pos,context->cid); 126 pos+=2; 127 event[pos++] = status; 128 memcpy(&event[pos], context->bd_addr, 6); 129 pos += 6; 130 little_endian_store_16(event,pos,context->con_handle); 131 pos += 2; 132 event[pos++] = context->incoming; 133 event[1] = pos - 2; 134 if (pos != sizeof(event)) log_error("goep_client_emit_connected_event size %u", pos); 135 context->client_handler(HCI_EVENT_PACKET, context->cid, &event[0], pos); 136 } 137 138 static inline void goep_client_emit_connection_closed_event(goep_client_t * context){ 139 uint8_t event[5]; 140 int pos = 0; 141 event[pos++] = HCI_EVENT_GOEP_META; 142 pos++; // skip len 143 event[pos++] = GOEP_SUBEVENT_CONNECTION_CLOSED; 144 little_endian_store_16(event,pos,context->cid); 145 pos+=2; 146 event[1] = pos - 2; 147 if (pos != sizeof(event)) log_error("goep_client_emit_connection_closed_event size %u", pos); 148 context->client_handler(HCI_EVENT_PACKET, context->cid, &event[0], pos); 149 } 150 151 static inline void goep_client_emit_can_send_now_event(goep_client_t * context){ 152 uint8_t event[5]; 153 int pos = 0; 154 event[pos++] = HCI_EVENT_GOEP_META; 155 pos++; // skip len 156 event[pos++] = GOEP_SUBEVENT_CAN_SEND_NOW; 157 little_endian_store_16(event,pos,context->cid); 158 pos+=2; 159 event[1] = pos - 2; 160 if (pos != sizeof(event)) log_error("goep_client_emit_can_send_now_event size %u", pos); 161 context->client_handler(HCI_EVENT_PACKET, context->cid, &event[0], pos); 162 } 163 164 static void goep_client_handle_connection_opened(goep_client_t * context, uint8_t status, uint16_t mtu){ 165 if (status) { 166 context->state = GOEP_INIT; 167 log_info("goep_client: open failed, status %u", status); 168 } else { 169 context->bearer_mtu = mtu; 170 context->state = GOEP_CONNECTED; 171 log_info("goep_client: connection opened. cid %u, max frame size %u", context->bearer_cid, context->bearer_mtu); 172 } 173 goep_client_emit_connected_event(context, status); 174 } 175 176 static void goep_client_handle_connection_close(goep_client_t * context){ 177 context->state = GOEP_INIT; 178 goep_client_emit_connection_closed_event(context); 179 } 180 181 static void goep_client_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 182 UNUSED(channel); 183 UNUSED(size); 184 goep_client_t * context = goep_client; 185 switch (packet_type){ 186 case HCI_EVENT_PACKET: 187 switch (hci_event_packet_get_type(packet)) { 188 #ifdef ENABLE_GOEP_L2CAP 189 case L2CAP_EVENT_CHANNEL_OPENED: 190 goep_client_handle_connection_opened(context, l2cap_event_channel_opened_get_status(packet), 191 btstack_min(l2cap_event_channel_opened_get_remote_mtu(packet), l2cap_event_channel_opened_get_local_mtu(packet))); 192 return; 193 case L2CAP_EVENT_CAN_SEND_NOW: 194 goep_client_emit_can_send_now_event(context); 195 break; 196 case L2CAP_EVENT_CHANNEL_CLOSED: 197 goep_client_handle_connection_close(context); 198 break; 199 #endif 200 case RFCOMM_EVENT_CHANNEL_OPENED: 201 goep_client_handle_connection_opened(context, rfcomm_event_channel_opened_get_status(packet), rfcomm_event_channel_opened_get_max_frame_size(packet)); 202 return; 203 case RFCOMM_EVENT_CAN_SEND_NOW: 204 goep_client_emit_can_send_now_event(context); 205 break; 206 case RFCOMM_EVENT_CHANNEL_CLOSED: 207 goep_client_handle_connection_close(context); 208 break; 209 default: 210 break; 211 } 212 break; 213 case L2CAP_DATA_PACKET: 214 case RFCOMM_DATA_PACKET: 215 context->client_handler(GOEP_DATA_PACKET, context->cid, packet, size); 216 break; 217 default: 218 break; 219 } 220 } 221 222 static void goep_client_handle_sdp_query_event(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){ 223 goep_client_t * context = goep_client; 224 225 UNUSED(packet_type); 226 UNUSED(channel); 227 UNUSED(size); 228 229 des_iterator_t des_list_it; 230 des_iterator_t prot_it; 231 uint8_t status; 232 233 234 switch (hci_event_packet_get_type(packet)){ 235 case SDP_EVENT_QUERY_ATTRIBUTE_VALUE: 236 237 // check if relevant attribute 238 switch(sdp_event_query_attribute_byte_get_attribute_id(packet)){ 239 case BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST: 240 case BLUETOOTH_ATTRIBUTE_PBAP_SUPPORTED_FEATURES: 241 #ifdef ENABLE_GOEP_L2CAP 242 case BLUETOOTH_ATTRIBUTE_GOEP_L2CAP_PSM: 243 #endif 244 break; 245 default: 246 return; 247 } 248 249 // warn if attribute too large to fit in our buffer 250 if (sdp_event_query_attribute_byte_get_attribute_length(packet) > attribute_value_buffer_size) { 251 log_error("SDP attribute value size exceeded for attribute %x: available %d, required %d", sdp_event_query_attribute_byte_get_attribute_id(packet), attribute_value_buffer_size, sdp_event_query_attribute_byte_get_attribute_length(packet)); 252 break; 253 } 254 255 // store single byte 256 attribute_value[sdp_event_query_attribute_byte_get_data_offset(packet)] = sdp_event_query_attribute_byte_get_data(packet); 257 258 // wait until value fully received 259 if ((uint16_t)(sdp_event_query_attribute_byte_get_data_offset(packet)+1) != sdp_event_query_attribute_byte_get_attribute_length(packet)) break; 260 261 // process attributes 262 switch(sdp_event_query_attribute_byte_get_attribute_id(packet)) { 263 case BLUETOOTH_ATTRIBUTE_PROTOCOL_DESCRIPTOR_LIST: 264 for (des_iterator_init(&des_list_it, attribute_value); des_iterator_has_more(&des_list_it); des_iterator_next(&des_list_it)) { 265 uint8_t *des_element; 266 uint8_t *element; 267 uint32_t uuid; 268 #ifdef ENABLE_GOEP_L2CAP 269 uint16_t l2cap_psm; 270 #endif 271 272 if (des_iterator_get_type(&des_list_it) != DE_DES) continue; 273 274 des_element = des_iterator_get_element(&des_list_it); 275 des_iterator_init(&prot_it, des_element); 276 277 // first element is UUID 278 element = des_iterator_get_element(&prot_it); 279 if (de_get_element_type(element) != DE_UUID) continue; 280 281 uuid = de_get_uuid32(element); 282 des_iterator_next(&prot_it); 283 if (!des_iterator_has_more(&prot_it)) continue; 284 285 // second element is RFCOMM server channel or L2CAP PSM 286 element = des_iterator_get_element(&prot_it); 287 switch (uuid){ 288 #ifdef ENABLE_GOEP_L2CAP 289 case BLUETOOTH_PROTOCOL_L2CAP: 290 if (de_element_get_uint16(element, &l2cap_psm)){ 291 context->l2cap_psm = l2cap_psm; 292 } 293 break; 294 #endif 295 case BLUETOOTH_PROTOCOL_RFCOMM: 296 context->rfcomm_port = element[de_get_header_size(element)]; 297 break; 298 default: 299 break; 300 } 301 } 302 break; 303 #ifdef ENABLE_GOEP_L2CAP 304 case BLUETOOTH_ATTRIBUTE_GOEP_L2CAP_PSM: 305 de_element_get_uint16(attribute_value, &context->l2cap_psm); 306 break; 307 #endif 308 case BLUETOOTH_ATTRIBUTE_PBAP_SUPPORTED_FEATURES: 309 if (de_get_element_type(attribute_value) != DE_UINT) break; 310 if (de_get_size_type(attribute_value) != DE_SIZE_32) break; 311 context->pbap_supported_features = big_endian_read_32(attribute_value, de_get_header_size(attribute_value)); 312 log_info("pbap_supported_features 0x%x", context->pbap_supported_features); 313 break; 314 default: 315 break; 316 } 317 break; 318 319 case SDP_EVENT_QUERY_COMPLETE: 320 status = sdp_event_query_complete_get_status(packet); 321 if (status != ERROR_CODE_SUCCESS){ 322 log_info("GOEP client, SDP query failed 0x%02x", status); 323 context->state = GOEP_INIT; 324 goep_client_emit_connected_event(goep_client, status); 325 break; 326 } 327 if (context->rfcomm_port == 0 && context->l2cap_psm == 0){ 328 log_info("No GOEP RFCOMM or L2CAP server found"); 329 context->state = GOEP_INIT; 330 goep_client_emit_connected_event(goep_client, ERROR_CODE_UNSUPPORTED_FEATURE_OR_PARAMETER_VALUE); 331 break; 332 } 333 #ifdef ENABLE_GOEP_L2CAP 334 if (context->l2cap_psm){ 335 log_info("Remote GOEP L2CAP PSM: %u", context->l2cap_psm); 336 l2cap_create_ertm_channel(&goep_client_packet_handler, context->bd_addr, context->l2cap_psm, 337 &ertm_config, ertm_buffer, sizeof(ertm_buffer), &context->bearer_cid); 338 return; 339 } 340 #endif 341 log_info("Remote GOEP RFCOMM Server Channel: %u", context->rfcomm_port); 342 rfcomm_create_channel(&goep_client_packet_handler, context->bd_addr, context->rfcomm_port, &context->bearer_cid); 343 } 344 } 345 346 static uint8_t * goep_client_get_outgoing_buffer(goep_client_t * context){ 347 if (context->l2cap_psm){ 348 return goep_packet_buffer; 349 } else { 350 return rfcomm_get_outgoing_buffer(); 351 } 352 } 353 354 static void goep_client_packet_append(const uint8_t * data, uint16_t len){ 355 goep_client_t * context = goep_client; 356 uint8_t * buffer = goep_client_get_outgoing_buffer(context); 357 uint16_t pos = big_endian_read_16(buffer, 1); 358 memcpy(&buffer[pos], data, len); 359 pos += len; 360 big_endian_store_16(buffer, 1, pos); 361 } 362 363 static void goep_client_packet_init(uint16_t goep_cid, uint8_t opcode){ 364 UNUSED(goep_cid); 365 goep_client_t * context = goep_client; 366 if (context->l2cap_psm){ 367 } else { 368 rfcomm_reserve_packet_buffer(); 369 } 370 uint8_t * buffer = goep_client_get_outgoing_buffer(context); 371 buffer[0] = opcode; 372 big_endian_store_16(buffer, 1, 3); 373 // store opcode for parsing of response 374 context->obex_opcode = opcode; 375 } 376 377 static void goep_client_packet_add_connection_id(uint16_t goep_cid){ 378 UNUSED(goep_cid); 379 goep_client_t * context = goep_client; 380 // add connection_id header if set, must be first header if used 381 if (context->obex_connection_id != OBEX_CONNECTION_ID_INVALID){ 382 goep_client_add_word_header(goep_cid, OBEX_HEADER_CONNECTION_ID, context->obex_connection_id); 383 } 384 } 385 386 void goep_client_init(void){ 387 memset(goep_client, 0, sizeof(goep_client_t)); 388 goep_client->state = GOEP_INIT; 389 goep_client->cid = 1; 390 goep_client->obex_connection_id = OBEX_CONNECTION_ID_INVALID; 391 } 392 393 uint8_t goep_client_create_connection(btstack_packet_handler_t handler, bd_addr_t addr, uint16_t uuid, uint16_t * out_cid){ 394 goep_client_t * context = goep_client; 395 if (context->state != GOEP_INIT) return BTSTACK_MEMORY_ALLOC_FAILED; 396 context->client_handler = handler; 397 context->state = GOEP_W4_SDP; 398 context->l2cap_psm = 0; 399 context->rfcomm_port = 0; 400 context->pbap_supported_features = PBAP_FEATURES_NOT_PRESENT; 401 memcpy(context->bd_addr, addr, 6); 402 sdp_client_query_uuid16(&goep_client_handle_sdp_query_event, context->bd_addr, uuid); 403 *out_cid = context->cid; 404 return 0; 405 } 406 407 uint32_t goep_client_get_pbap_supported_features(uint16_t goep_cid){ 408 UNUSED(goep_cid); 409 goep_client_t * context = goep_client; 410 return context->pbap_supported_features; 411 } 412 413 uint8_t goep_client_disconnect(uint16_t goep_cid){ 414 UNUSED(goep_cid); 415 goep_client_t * context = goep_client; 416 rfcomm_disconnect(context->bearer_cid); 417 return 0; 418 } 419 420 void goep_client_set_connection_id(uint16_t goep_cid, uint32_t connection_id){ 421 UNUSED(goep_cid); 422 goep_client_t * context = goep_client; 423 context->obex_connection_id = connection_id; 424 } 425 426 uint8_t goep_client_get_request_opcode(uint16_t goep_cid){ 427 UNUSED(goep_cid); 428 goep_client_t * context = goep_client; 429 return context->obex_opcode; 430 } 431 432 void goep_client_request_can_send_now(uint16_t goep_cid){ 433 UNUSED(goep_cid); 434 goep_client_t * context = goep_client; 435 if (context->l2cap_psm){ 436 l2cap_request_can_send_now_event(context->bearer_cid); 437 } else { 438 rfcomm_request_can_send_now_event(context->bearer_cid); 439 } 440 } 441 442 void goep_client_create_connect_request(uint16_t goep_cid, uint8_t obex_version_number, uint8_t flags, uint16_t maximum_obex_packet_length){ 443 UNUSED(goep_cid); 444 goep_client_t * context = goep_client; 445 goep_client_packet_init(goep_cid, OBEX_OPCODE_CONNECT); 446 uint8_t fields[4]; 447 fields[0] = obex_version_number; 448 fields[1] = flags; 449 // workaround: limit OBEX packet len to L2CAP/RFCOMM MTU to avoid handling of fragemented packets 450 maximum_obex_packet_length = btstack_min(maximum_obex_packet_length, context->bearer_mtu); 451 big_endian_store_16(fields, 2, maximum_obex_packet_length); 452 goep_client_packet_append(&fields[0], sizeof(fields)); 453 } 454 455 void goep_client_create_get_request(uint16_t goep_cid){ 456 goep_client_packet_init(goep_cid, OBEX_OPCODE_GET | OBEX_OPCODE_FINAL_BIT_MASK); 457 goep_client_packet_add_connection_id(goep_cid); 458 } 459 460 void goep_client_create_set_path_request(uint16_t goep_cid, uint8_t flags){ 461 UNUSED(goep_cid); 462 goep_client_packet_init(goep_cid, OBEX_OPCODE_SETPATH); 463 uint8_t fields[2]; 464 fields[0] = flags; 465 fields[1] = 0; // reserved 466 goep_client_packet_append(&fields[0], sizeof(fields)); 467 goep_client_packet_add_connection_id(goep_cid); 468 } 469 470 void goep_client_create_abort_request(uint16_t goep_cid){ 471 goep_client_packet_init(goep_cid, OBEX_OPCODE_ABORT); 472 goep_client_packet_add_connection_id(goep_cid); 473 } 474 475 void goep_client_create_disconnect_request(uint16_t goep_cid){ 476 UNUSED(goep_cid); 477 goep_client_packet_init(goep_cid, OBEX_OPCODE_DISCONNECT); 478 goep_client_packet_add_connection_id(goep_cid); 479 } 480 481 void goep_client_add_variable_header(uint16_t goep_cid, uint8_t header_type, uint16_t header_data_length, const uint8_t * header_data){ 482 UNUSED(goep_cid); 483 uint8_t header[3]; 484 header[0] = header_type; 485 big_endian_store_16(header, 1, sizeof(header) + header_data_length); 486 goep_client_packet_append(&header[0], sizeof(header)); 487 goep_client_packet_append(header_data, header_data_length); 488 } 489 490 void goep_client_add_byte_header(uint16_t goep_cid, uint8_t header_type, uint8_t value){ 491 UNUSED(goep_cid); 492 uint8_t header[2]; 493 header[0] = header_type; 494 header[1] = value; 495 goep_client_packet_append(&header[0], sizeof(header)); 496 } 497 498 void goep_client_add_word_header(uint16_t goep_cid, uint8_t header_type, uint32_t value){ 499 UNUSED(goep_cid); 500 uint8_t header[5]; 501 header[0] = header_type; 502 big_endian_store_32(header, 1, value); 503 goep_client_packet_append(&header[0], sizeof(header)); 504 } 505 506 void goep_client_add_header_srm_enable(uint16_t goep_cid){ 507 goep_client_add_byte_header(goep_cid, OBEX_HEADER_SINGLE_RESPONSE_MODE, OBEX_SRM_ENABLE); 508 } 509 510 void goep_client_add_header_target(uint16_t goep_cid, uint16_t length, const uint8_t * target){ 511 goep_client_add_variable_header(goep_cid, OBEX_HEADER_TARGET, length, target); 512 } 513 514 void goep_client_add_header_application_parameters(uint16_t goep_cid, uint16_t length, const uint8_t * data){ 515 goep_client_add_variable_header(goep_cid, OBEX_HEADER_APPLICATION_PARAMETERS, length, data); 516 } 517 518 void goep_client_add_header_challenge_response(uint16_t goep_cid, uint16_t length, const uint8_t * data){ 519 goep_client_add_variable_header(goep_cid, OBEX_HEADER_AUTHENTICATION_RESPONSE, length, data); 520 } 521 522 void goep_client_add_header_name(uint16_t goep_cid, const char * name){ 523 UNUSED(goep_cid); 524 goep_client_t * context = goep_client; 525 int len = strlen(name); 526 if (len) { 527 // empty string does not have trailing \0 528 len++; 529 } 530 uint8_t * buffer = goep_client_get_outgoing_buffer(context); 531 uint16_t pos = big_endian_read_16(buffer, 1); 532 buffer[pos++] = OBEX_HEADER_NAME; 533 big_endian_store_16(buffer, pos, 1 + 2 + len*2); 534 pos += 2; 535 int i; 536 // @note name[len] == 0 537 for (i = 0 ; i < len ; i++){ 538 buffer[pos++] = 0; 539 buffer[pos++] = *name++; 540 } 541 big_endian_store_16(buffer, 1, pos); 542 } 543 544 void goep_client_add_header_type(uint16_t goep_cid, const char * type){ 545 UNUSED(goep_cid); 546 uint8_t header[3]; 547 header[0] = OBEX_HEADER_TYPE; 548 int len_incl_zero = strlen(type) + 1; 549 big_endian_store_16(header, 1, 1 + 2 + len_incl_zero); 550 goep_client_packet_append(&header[0], sizeof(header)); 551 goep_client_packet_append((const uint8_t*)type, len_incl_zero); 552 } 553 554 int goep_client_execute(uint16_t goep_cid){ 555 UNUSED(goep_cid); 556 goep_client_t * context = goep_client; 557 uint8_t * buffer = goep_client_get_outgoing_buffer(context); 558 uint16_t pos = big_endian_read_16(buffer, 1); 559 if (context->l2cap_psm){ 560 return l2cap_send(context->bearer_cid, buffer, pos); 561 } else { 562 return rfcomm_send_prepared(context->bearer_cid, pos); 563 } 564 } 565