tools/idevicebtlogger.c - third_party/libimobiledevice - Git at Google

 /*
  * idevicebt_packet_logger.c
  * Capture Bluetooth HCI traffic to native PKLG or PCAP
  *
  * Copyright (c) 2021 Geoffrey Kruse, All Rights Reserved.
  * Copyright (c) 2022 Matthias Ringwald, All Rights Reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */

 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif

 #define TOOL_NAME "idevicebtlogger"

 #include <stdio.h>
 #include <string.h>
 #include <errno.h>
 #include <signal.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <getopt.h>
 #include <assert.h>
 #include <fcntl.h>

 #ifdef WIN32
 #include <windows.h>
 #define sleep(x) Sleep(x*1000)
 #else
 #include <arpa/inet.h>
 #endif


 #include <libimobiledevice/libimobiledevice.h>
 #include <libimobiledevice/bt_packet_logger.h>

 typedef enum {
 	HCI_COMMAND = 0x00,
 	HCI_EVENT = 0x01,
 	SENT_ACL_DATA = 0x02,
 	RECV_ACL_DATA = 0x03,
 	SENT_SCO_DATA = 0x08,
 	RECV_SCO_DATA = 0x09,
 } PacketLoggerPacketType;

 static int quit_flag = 0;
 static int exit_on_disconnect = 0;

 static char* udid = NULL;
 static idevice_t device = NULL;
 static bt_packet_logger_client_t bt_packet_logger = NULL;
 static int use_network = 0;
 static char* out_filename = NULL;
 static char* log_format_string = NULL;
 static FILE * packetlogger_file = NULL;

 static enum {
 	LOG_FORMAT_PACKETLOGGER,
 	LOG_FORMAT_PCAP
 } log_format = LOG_FORMAT_PACKETLOGGER;

 const uint8_t pcap_file_header[] = {
 	// Magic Number
 	0xA1, 0xB2, 0xC3, 0xD4,
 	// Major / Minor Version
 	0x00, 0x02, 0x00, 0x04,
 	// Reserved1
 	0x00, 0x00, 0x00, 0x00,
 	// Reserved2
 	0x00, 0x00, 0x00, 0x00,
 	// Snaplen == max packet size - use 2kB (larger than any ACL)
 	0x00, 0x00, 0x08, 0x00,
 	// LinkType: DLT_BLUETOOTH_HCI_H4_WITH_PHDR
 	0x00, 0x00, 0x00, 201,
 };

 static uint32_t big_endian_read_32(const uint8_t * buffer, int position)
 {
 	return ((uint32_t) buffer[position+3]) | (((uint32_t)buffer[position+2]) << 8) | (((uint32_t)buffer[position+1]) << 16) | (((uint32_t) buffer[position]) << 24);
 }

 static void big_endian_store_32(uint8_t * buffer, uint16_t position, uint32_t value)
 {
 	uint16_t pos = position;
 	buffer[pos++] = (uint8_t)(value >> 24);
 	buffer[pos++] = (uint8_t)(value >> 16);
 	buffer[pos++] = (uint8_t)(value >> 8);
 	buffer[pos++] = (uint8_t)(value);
 }

 /**
  * Callback from the packet logger service to handle packets and log to PacketLogger format
  */
 static void bt_packet_logger_callback_packetlogger(uint8_t * data, uint16_t len, void *user_data)
 {
 	(void) fwrite(data, 1, len, packetlogger_file);
 }

 /**
  * Callback from the packet logger service to handle packets and log to pcap
  */
 static void bt_packet_logger_callback_pcap(uint8_t * data, uint16_t len, void *user_data)
 {
 	// check len
 	if (len < 13) {
 		return;
 	}

 	// parse packet header (ignore len field)
 	uint32_t ts_secs = big_endian_read_32(data, 4);
 	uint32_t ts_us   = big_endian_read_32(data, 8);
 	uint8_t packet_type = data[12];
 	data += 13;
 	len  -= 13;

 	// map PacketLogger packet type onto PCAP direction flag and hci_h4_type
 	uint8_t direction_in = 0;
 	uint8_t hci_h4_type  = 0xff;
 	switch(packet_type) {
 		case HCI_COMMAND:
 			hci_h4_type = 0x01;
 			direction_in = 0;
 			break;
 		case SENT_ACL_DATA:
 			hci_h4_type = 0x02;
 			direction_in = 0;
 			break;
 		case RECV_ACL_DATA:
 			hci_h4_type = 0x02;
 			direction_in = 1;
 			break;
 		case SENT_SCO_DATA:
 			hci_h4_type = 0x03;
 			direction_in = 0;
 			break;
 		case RECV_SCO_DATA:
 			hci_h4_type = 0x03;
 			direction_in = 1;
 			break;
 		case HCI_EVENT:
 			hci_h4_type = 0x04;
 			direction_in = 1;
 			break;
 		default:
 			// unknown packet logger type, drop packet
 			return;
 	}

 	// setup pcap record header, 4 byte direction flag, 1 byte HCI H4 packet type, data
 	uint8_t pcap_record_header[21];
 	big_endian_store_32(pcap_record_header,  0, ts_secs);       // Timestamp seconds
 	big_endian_store_32(pcap_record_header,  4, ts_us);         // Timestamp microseconds
 	big_endian_store_32(pcap_record_header,  8, 4 + 1 + len);   // Captured  Packet Length
 	big_endian_store_32(pcap_record_header, 12, 4 + 1 + len);   // Original Packet Length
 	big_endian_store_32(pcap_record_header, 16, direction_in);  // Direction: Incoming = 1
 	pcap_record_header[20] = hci_h4_type;

 	// write header
 	(void) fwrite(pcap_record_header, 1, sizeof(pcap_record_header), packetlogger_file);

 	// write packet
 	(void) fwrite(data, 1, len, packetlogger_file);

 	// flush
 	(void) fflush(packetlogger_file);
 }

 /**
  * Disable HCI log capture
  */
 static void stop_logging(void)
 {
 	fflush(NULL);

 	if (bt_packet_logger) {
 		bt_packet_logger_client_free(bt_packet_logger);
 		bt_packet_logger = NULL;
 	}

 	if (device) {
 		idevice_free(device);
 		device = NULL;
 	}
 }

 /**
  * Enable HCI log capture
  */
 static int start_logging(void)
 {
 	idevice_error_t ret = idevice_new_with_options(&device, udid, (use_network) ? IDEVICE_LOOKUP_NETWORK : IDEVICE_LOOKUP_USBMUX);
 	if (ret != IDEVICE_E_SUCCESS) {
 		fprintf(stderr, "Device with udid %s not found!?\n", udid);
 		return -1;
 	}

 	lockdownd_client_t lockdown = NULL;
 	lockdownd_error_t lerr = lockdownd_client_new_with_handshake(device, &lockdown, TOOL_NAME);
 	if (lerr != LOCKDOWN_E_SUCCESS) {
 		fprintf(stderr, "ERROR: Could not connect to lockdownd: %d\n", lerr);
 		idevice_free(device);
 		device = NULL;
 		return -1;
 	}

 	/* start bt_packet_logger service */
 	bt_packet_logger_client_start_service(device, &bt_packet_logger, TOOL_NAME);

 	/* start capturing bt_packet_logger */
 	void (*callback)(uint8_t * data, uint16_t len, void *user_data);
 	switch (log_format){
 		case LOG_FORMAT_PCAP:
 			callback = bt_packet_logger_callback_pcap;
 			break;
 		case LOG_FORMAT_PACKETLOGGER:
 			callback = bt_packet_logger_callback_packetlogger;
 			break;
 		default:
 			assert(0);
 			return 0;
 	}
 	bt_packet_logger_error_t serr = bt_packet_logger_start_capture(bt_packet_logger, callback, NULL);
 	if (serr != BT_PACKET_LOGGER_E_SUCCESS) {
 		fprintf(stderr, "ERROR: Unable to start capturing bt_packet_logger.\n");
 		bt_packet_logger_client_free(bt_packet_logger);
 		bt_packet_logger = NULL;
 		idevice_free(device);
 		device = NULL;
 		return -1;
 	}

 	fprintf(stderr, "[connected:%s]\n", udid);
 	fflush(stderr);

 	return 0;
 }

 /**
  * Callback for device events
  */
 static void device_event_cb(const idevice_event_t* event, void* userdata)
 {
 	if (use_network && event->conn_type != CONNECTION_NETWORK) {
 		return;
 	} else if (!use_network && event->conn_type != CONNECTION_USBMUXD) {
 		return;
 	}
 	if (event->event == IDEVICE_DEVICE_ADD) {
 		if (!bt_packet_logger) {
 			if (!udid) {
 				udid = strdup(event->udid);
 			}
 			if (strcmp(udid, event->udid) == 0) {
 				if (start_logging() != 0) {
 					fprintf(stderr, "Could not start logger for udid %s\n", udid);
 				}
 			}
 		}
 	} else if (event->event == IDEVICE_DEVICE_REMOVE) {
 		if (bt_packet_logger && (strcmp(udid, event->udid) == 0)) {
 			stop_logging();
 			fprintf(stderr, "[disconnected:%s]\n", udid);
 			if (exit_on_disconnect) {
 				quit_flag++;
 			}
 		}
 	}
 }

 /**
  * signal handler function for cleaning up properly
  */
 static void clean_exit(int sig)
 {
 	fprintf(stderr, "\nExiting...\n");
 	quit_flag++;
 }

 /**
  * print usage information
  */
 static void print_usage(int argc, char **argv, int is_error)
 {
 	char *name = NULL;
 	name = strrchr(argv[0], '/');
 	fprintf(is_error ? stderr : stdout, "Usage: %s [OPTIONS] <FILE>\n", (name ? name + 1: argv[0]));
 	fprintf(is_error ? stderr : stdout,
 		"\n" \
 		"Capture HCI packets from a connected device.\n" \
 		"\n" \
 		"OPTIONS:\n" \
 		"  -u, --udid UDID     target specific device by UDID\n" \
 		"  -n, --network       connect to network device\n" \
 		"  -f, --format FORMAT logging format: packetlogger (default) or pcap\n" \
 		"  -x, --exit          exit when device disconnects\n" \
 		"  -h, --help          prints usage information\n" \
 		"  -d, --debug         enable communication debugging\n" \
 		"  -v, --version       prints version information\n" \
 		"\n" \
 		"Homepage:    <" PACKAGE_URL ">\n"
 		"Bug Reports: <" PACKAGE_BUGREPORT ">\n"
 	);
 }

 /**
  * Program entry
  */
 int main(int argc, char *argv[])
 {
 	int c = 0;
 	const struct option longopts[] = {
 		{ "debug", no_argument, NULL, 'd' },
 		{ "help", no_argument, NULL, 'h' },
 		{ "udid", required_argument, NULL, 'u' },
 		{ "format", required_argument, NULL, 'f' },
 		{ "network", no_argument, NULL, 'n' },
 		{ "exit", no_argument, NULL, 'x' },
 		{ "version", no_argument, NULL, 'v' },
 		{ NULL, 0, NULL, 0}
 	};

 	signal(SIGINT, clean_exit);
 	signal(SIGTERM, clean_exit);
 #ifndef WIN32
 	signal(SIGQUIT, clean_exit);
 	signal(SIGPIPE, SIG_IGN);
 #endif

 	while ((c = getopt_long(argc, argv, "dhu:f:nxv", longopts, NULL)) != -1) {
 		switch (c) {
 		case 'd':
 			idevice_set_debug_level(1);
 			break;
 		case 'u':
 			if (!*optarg) {
 				fprintf(stderr, "ERROR: UDID must not be empty!\n");
 				print_usage(argc, argv, 1);
 				return 2;
 			}
 			free(udid);
 			udid = strdup(optarg);
 			break;
 		case 'f':
 			if (!*optarg) {
 				fprintf(stderr, "ERROR: FORMAT must not be empty!\n");
 				print_usage(argc, argv, 1);
 				return 2;
 			}
 			free(log_format_string);
 			log_format_string = strdup(optarg);
 			break;
 		case 'n':
 			use_network = 1;
 			break;
 		case 'x':
 			exit_on_disconnect = 1;
 			break;
 		case 'h':
 			print_usage(argc, argv, 0);
 			return 0;
 		case 'v':
 			printf("%s %s\n", TOOL_NAME, PACKAGE_VERSION);
 			return 0;
 		default:
 			print_usage(argc, argv, 1);
 			return 2;
 		}
 	}

 	if (optind < argc) {
 		out_filename = argv[optind];
 		// printf("Output File: %s\n", out_filename);
 	}
 	else {
 		print_usage(argc, argv, 1);
 		return 2;
 	}

 	if (log_format_string != NULL){
 		if (strcmp("packetlogger", log_format_string) == 0){
 			log_format = LOG_FORMAT_PACKETLOGGER;
 		} else if (strcmp("pcap", log_format_string) == 0){
 			log_format = LOG_FORMAT_PCAP;
 		} else {
 			printf("Unknown logging format: '%s'\n", log_format_string);
 			print_usage(argc, argv, 1);
 			return 2;
 		}
 	}

 	int num = 0;
 	idevice_info_t *devices = NULL;
 	idevice_get_device_list_extended(&devices, &num);
 	idevice_device_list_extended_free(devices);
 	if (num == 0) {
 		if (!udid) {
 			fprintf(stderr, "No device found. Plug in a device or pass UDID with -u to wait for device to be available.\n");
 			return -1;
 		} else {
 			fprintf(stderr, "Waiting for device with UDID %s to become available...\n", udid);
 		}
 	}

 	// support streaming to stdout
 	if (strcmp(out_filename, "-") == 0){
 		packetlogger_file = stdout;
 	} else {
 		packetlogger_file = fopen(out_filename, "wb");
 	}


 	if (packetlogger_file == NULL){
 		fprintf(stderr, "Failed to open file %s, errno = %d\n", out_filename, errno);
 		return -2;
 	}

 	switch (log_format){
 		case LOG_FORMAT_PCAP:
 			// printf("Output Format: PCAP\n");
 			// write PCAP file header
 			(void) fwrite(&pcap_file_header, 1, sizeof(pcap_file_header), packetlogger_file);
 			break;
 		case LOG_FORMAT_PACKETLOGGER:
 			printf("Output Format: PacketLogger\n");
 			break;
 		default:
 			assert(0);
 			return -2;
 	}
 	idevice_subscription_context_t context = NULL;
 	idevice_events_subscribe(&context, device_event_cb, NULL);

 	while (!quit_flag) {
 		sleep(1);
 	}

 	idevice_events_unsubscribe(context);
 	stop_logging();

 	fclose(packetlogger_file);

 	free(udid);

 	return 0;
 }
	/*
	* idevicebt_packet_logger.c
	* Capture Bluetooth HCI traffic to native PKLG or PCAP
	*
	* Copyright (c) 2021 Geoffrey Kruse, All Rights Reserved.
	* Copyright (c) 2022 Matthias Ringwald, All Rights Reserved.
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Lesser General Public
	* License as published by the Free Software Foundation; either
	* version 2.1 of the License, or (at your option) any later version.
	*
	* This library is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Lesser General Public License for more details.
	*
	* You should have received a copy of the GNU Lesser General Public
	* License along with this library; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	*/

	#ifdef HAVE_CONFIG_H
	#include "config.h"
	#endif

	#define TOOL_NAME "idevicebtlogger"

	#include <stdio.h>
	#include <string.h>
	#include <errno.h>
	#include <signal.h>
	#include <stdlib.h>
	#include <unistd.h>
	#include <getopt.h>
	#include <assert.h>
	#include <fcntl.h>

	#ifdef WIN32
	#include <windows.h>
	#define sleep(x) Sleep(x*1000)
	#else
	#include <arpa/inet.h>
	#endif


	#include <libimobiledevice/libimobiledevice.h>
	#include <libimobiledevice/bt_packet_logger.h>

	typedef enum {
	HCI_COMMAND = 0x00,
	HCI_EVENT = 0x01,
	SENT_ACL_DATA = 0x02,
	RECV_ACL_DATA = 0x03,
	SENT_SCO_DATA = 0x08,
	RECV_SCO_DATA = 0x09,
	} PacketLoggerPacketType;

	static int quit_flag = 0;
	static int exit_on_disconnect = 0;

	static char* udid = NULL;
	static idevice_t device = NULL;
	static bt_packet_logger_client_t bt_packet_logger = NULL;
	static int use_network = 0;
	static char* out_filename = NULL;
	static char* log_format_string = NULL;
	static FILE * packetlogger_file = NULL;

	static enum {
	LOG_FORMAT_PACKETLOGGER,
	LOG_FORMAT_PCAP
	} log_format = LOG_FORMAT_PACKETLOGGER;

	const uint8_t pcap_file_header[] = {
	// Magic Number
	0xA1, 0xB2, 0xC3, 0xD4,
	// Major / Minor Version
	0x00, 0x02, 0x00, 0x04,
	// Reserved1
	0x00, 0x00, 0x00, 0x00,
	// Reserved2
	0x00, 0x00, 0x00, 0x00,
	// Snaplen == max packet size - use 2kB (larger than any ACL)
	0x00, 0x00, 0x08, 0x00,
	// LinkType: DLT_BLUETOOTH_HCI_H4_WITH_PHDR
	0x00, 0x00, 0x00, 201,
	};

	static uint32_t big_endian_read_32(const uint8_t * buffer, int position)
	{
	return ((uint32_t) buffer[position+3]) \| (((uint32_t)buffer[position+2]) << 8) \| (((uint32_t)buffer[position+1]) << 16) \| (((uint32_t) buffer[position]) << 24);
	}

	static void big_endian_store_32(uint8_t * buffer, uint16_t position, uint32_t value)
	{
	uint16_t pos = position;
	buffer[pos++] = (uint8_t)(value >> 24);
	buffer[pos++] = (uint8_t)(value >> 16);
	buffer[pos++] = (uint8_t)(value >> 8);
	buffer[pos++] = (uint8_t)(value);
	}

	/**
	* Callback from the packet logger service to handle packets and log to PacketLogger format
	*/
	static void bt_packet_logger_callback_packetlogger(uint8_t * data, uint16_t len, void *user_data)
	{
	(void) fwrite(data, 1, len, packetlogger_file);
	}

	/**
	* Callback from the packet logger service to handle packets and log to pcap
	*/
	static void bt_packet_logger_callback_pcap(uint8_t * data, uint16_t len, void *user_data)
	{
	// check len
	if (len < 13) {
	return;
	}

	// parse packet header (ignore len field)
	uint32_t ts_secs = big_endian_read_32(data, 4);
	uint32_t ts_us = big_endian_read_32(data, 8);
	uint8_t packet_type = data[12];
	data += 13;
	len -= 13;

	// map PacketLogger packet type onto PCAP direction flag and hci_h4_type
	uint8_t direction_in = 0;
	uint8_t hci_h4_type = 0xff;
	switch(packet_type) {
	case HCI_COMMAND:
	hci_h4_type = 0x01;
	direction_in = 0;
	break;
	case SENT_ACL_DATA:
	hci_h4_type = 0x02;
	direction_in = 0;
	break;
	case RECV_ACL_DATA:
	hci_h4_type = 0x02;
	direction_in = 1;
	break;
	case SENT_SCO_DATA:
	hci_h4_type = 0x03;
	direction_in = 0;
	break;
	case RECV_SCO_DATA:
	hci_h4_type = 0x03;
	direction_in = 1;
	break;
	case HCI_EVENT:
	hci_h4_type = 0x04;
	direction_in = 1;
	break;
	default:
	// unknown packet logger type, drop packet
	return;
	}

	// setup pcap record header, 4 byte direction flag, 1 byte HCI H4 packet type, data
	uint8_t pcap_record_header[21];
	big_endian_store_32(pcap_record_header, 0, ts_secs); // Timestamp seconds
	big_endian_store_32(pcap_record_header, 4, ts_us); // Timestamp microseconds
	big_endian_store_32(pcap_record_header, 8, 4 + 1 + len); // Captured Packet Length
	big_endian_store_32(pcap_record_header, 12, 4 + 1 + len); // Original Packet Length
	big_endian_store_32(pcap_record_header, 16, direction_in); // Direction: Incoming = 1
	pcap_record_header[20] = hci_h4_type;

	// write header
	(void) fwrite(pcap_record_header, 1, sizeof(pcap_record_header), packetlogger_file);

	// write packet
	(void) fwrite(data, 1, len, packetlogger_file);

	// flush
	(void) fflush(packetlogger_file);
	}

	/**
	* Disable HCI log capture
	*/
	static void stop_logging(void)
	{
	fflush(NULL);

	if (bt_packet_logger) {
	bt_packet_logger_client_free(bt_packet_logger);
	bt_packet_logger = NULL;
	}

	if (device) {
	idevice_free(device);
	device = NULL;
	}
	}

	/**
	* Enable HCI log capture
	*/
	static int start_logging(void)
	{
	idevice_error_t ret = idevice_new_with_options(&device, udid, (use_network) ? IDEVICE_LOOKUP_NETWORK : IDEVICE_LOOKUP_USBMUX);
	if (ret != IDEVICE_E_SUCCESS) {
	fprintf(stderr, "Device with udid %s not found!?\n", udid);
	return -1;
	}

	lockdownd_client_t lockdown = NULL;
	lockdownd_error_t lerr = lockdownd_client_new_with_handshake(device, &lockdown, TOOL_NAME);
	if (lerr != LOCKDOWN_E_SUCCESS) {
	fprintf(stderr, "ERROR: Could not connect to lockdownd: %d\n", lerr);
	idevice_free(device);
	device = NULL;
	return -1;
	}

	/* start bt_packet_logger service */
	bt_packet_logger_client_start_service(device, &bt_packet_logger, TOOL_NAME);

	/* start capturing bt_packet_logger */
	void (callback)(uint8_t data, uint16_t len, void *user_data);
	switch (log_format){
	case LOG_FORMAT_PCAP:
	callback = bt_packet_logger_callback_pcap;
	break;
	case LOG_FORMAT_PACKETLOGGER:
	callback = bt_packet_logger_callback_packetlogger;
	break;
	default:
	assert(0);
	return 0;
	}
	bt_packet_logger_error_t serr = bt_packet_logger_start_capture(bt_packet_logger, callback, NULL);
	if (serr != BT_PACKET_LOGGER_E_SUCCESS) {
	fprintf(stderr, "ERROR: Unable to start capturing bt_packet_logger.\n");
	bt_packet_logger_client_free(bt_packet_logger);
	bt_packet_logger = NULL;
	idevice_free(device);
	device = NULL;
	return -1;
	}

	fprintf(stderr, "[connected:%s]\n", udid);
	fflush(stderr);

	return 0;
	}

	/**
	* Callback for device events
	*/
	static void device_event_cb(const idevice_event_t* event, void* userdata)
	{
	if (use_network && event->conn_type != CONNECTION_NETWORK) {
	return;
	} else if (!use_network && event->conn_type != CONNECTION_USBMUXD) {
	return;
	}
	if (event->event == IDEVICE_DEVICE_ADD) {
	if (!bt_packet_logger) {
	if (!udid) {
	udid = strdup(event->udid);
	}
	if (strcmp(udid, event->udid) == 0) {
	if (start_logging() != 0) {
	fprintf(stderr, "Could not start logger for udid %s\n", udid);
	}
	}
	}
	} else if (event->event == IDEVICE_DEVICE_REMOVE) {
	if (bt_packet_logger && (strcmp(udid, event->udid) == 0)) {
	stop_logging();
	fprintf(stderr, "[disconnected:%s]\n", udid);
	if (exit_on_disconnect) {
	quit_flag++;
	}
	}
	}
	}

	/**
	* signal handler function for cleaning up properly
	*/
	static void clean_exit(int sig)
	{
	fprintf(stderr, "\nExiting...\n");
	quit_flag++;
	}

	/**
	* print usage information
	*/
	static void print_usage(int argc, char **argv, int is_error)
	{
	char *name = NULL;
	name = strrchr(argv[0], '/');
	fprintf(is_error ? stderr : stdout, "Usage: %s [OPTIONS] <FILE>\n", (name ? name + 1: argv[0]));
	fprintf(is_error ? stderr : stdout,
	"\n" \
	"Capture HCI packets from a connected device.\n" \
	"\n" \
	"OPTIONS:\n" \
	" -u, --udid UDID target specific device by UDID\n" \
	" -n, --network connect to network device\n" \
	" -f, --format FORMAT logging format: packetlogger (default) or pcap\n" \
	" -x, --exit exit when device disconnects\n" \
	" -h, --help prints usage information\n" \
	" -d, --debug enable communication debugging\n" \
	" -v, --version prints version information\n" \
	"\n" \
	"Homepage: <" PACKAGE_URL ">\n"
	"Bug Reports: <" PACKAGE_BUGREPORT ">\n"
	);
	}

	/**
	* Program entry
	*/
	int main(int argc, char *argv[])
	{
	int c = 0;
	const struct option longopts[] = {
	{ "debug", no_argument, NULL, 'd' },
	{ "help", no_argument, NULL, 'h' },
	{ "udid", required_argument, NULL, 'u' },
	{ "format", required_argument, NULL, 'f' },
	{ "network", no_argument, NULL, 'n' },
	{ "exit", no_argument, NULL, 'x' },
	{ "version", no_argument, NULL, 'v' },
	{ NULL, 0, NULL, 0}
	};

	signal(SIGINT, clean_exit);
	signal(SIGTERM, clean_exit);
	#ifndef WIN32
	signal(SIGQUIT, clean_exit);
	signal(SIGPIPE, SIG_IGN);
	#endif

	while ((c = getopt_long(argc, argv, "dhu:f:nxv", longopts, NULL)) != -1) {
	switch (c) {
	case 'd':
	idevice_set_debug_level(1);
	break;
	case 'u':
	if (!*optarg) {
	fprintf(stderr, "ERROR: UDID must not be empty!\n");
	print_usage(argc, argv, 1);
	return 2;
	}
	free(udid);
	udid = strdup(optarg);
	break;
	case 'f':
	if (!*optarg) {
	fprintf(stderr, "ERROR: FORMAT must not be empty!\n");
	print_usage(argc, argv, 1);
	return 2;
	}
	free(log_format_string);
	log_format_string = strdup(optarg);
	break;
	case 'n':
	use_network = 1;
	break;
	case 'x':
	exit_on_disconnect = 1;
	break;
	case 'h':
	print_usage(argc, argv, 0);
	return 0;
	case 'v':
	printf("%s %s\n", TOOL_NAME, PACKAGE_VERSION);
	return 0;
	default:
	print_usage(argc, argv, 1);
	return 2;
	}
	}

	if (optind < argc) {
	out_filename = argv[optind];
	// printf("Output File: %s\n", out_filename);
	}
	else {
	print_usage(argc, argv, 1);
	return 2;
	}

	if (log_format_string != NULL){
	if (strcmp("packetlogger", log_format_string) == 0){
	log_format = LOG_FORMAT_PACKETLOGGER;
	} else if (strcmp("pcap", log_format_string) == 0){
	log_format = LOG_FORMAT_PCAP;
	} else {
	printf("Unknown logging format: '%s'\n", log_format_string);
	print_usage(argc, argv, 1);
	return 2;
	}
	}

	int num = 0;
	idevice_info_t *devices = NULL;
	idevice_get_device_list_extended(&devices, &num);
	idevice_device_list_extended_free(devices);
	if (num == 0) {
	if (!udid) {
	fprintf(stderr, "No device found. Plug in a device or pass UDID with -u to wait for device to be available.\n");
	return -1;
	} else {
	fprintf(stderr, "Waiting for device with UDID %s to become available...\n", udid);
	}
	}

	// support streaming to stdout
	if (strcmp(out_filename, "-") == 0){
	packetlogger_file = stdout;
	} else {
	packetlogger_file = fopen(out_filename, "wb");
	}


	if (packetlogger_file == NULL){
	fprintf(stderr, "Failed to open file %s, errno = %d\n", out_filename, errno);
	return -2;
	}

	switch (log_format){
	case LOG_FORMAT_PCAP:
	// printf("Output Format: PCAP\n");
	// write PCAP file header
	(void) fwrite(&pcap_file_header, 1, sizeof(pcap_file_header), packetlogger_file);
	break;
	case LOG_FORMAT_PACKETLOGGER:
	printf("Output Format: PacketLogger\n");
	break;
	default:
	assert(0);
	return -2;
	}
	idevice_subscription_context_t context = NULL;
	idevice_events_subscribe(&context, device_event_cb, NULL);

	while (!quit_flag) {
	sleep(1);
	}

	idevice_events_unsubscribe(context);
	stop_logging();

	fclose(packetlogger_file);

	free(udid);

	return 0;
	}