tools/iproxy.c - third_party/libusbmuxd - Git at Google

 /*
  * iproxy.c -- proxy that enables tcp service access to iOS devices
  *
  * Copyright (C) 2009-2020 Nikias Bassen <nikias@gmx.li>
  * Copyright (C) 2014      Martin Szulecki <m.szulecki@libimobiledevice.org>
  * Copyright (C) 2009      Paul Sladen <libiphone@paul.sladen.org>
  *
  * Based upon iTunnel source code, Copyright (c) 2008 Jing Su.
  * http://www.cs.toronto.edu/~jingsu/itunnel/
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program 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 General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; 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 "iproxy"

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <fcntl.h>
 #include <stddef.h>
 #include <unistd.h>
 #include <errno.h>
 #include <getopt.h>
 #ifdef WIN32
 #include <winsock2.h>
 #include <windows.h>
 typedef unsigned int socklen_t;
 #else
 #include <sys/select.h>
 #include <sys/socket.h>
 #include <signal.h>
 #endif
 #include <libimobiledevice-glue/socket.h>
 #include <libimobiledevice-glue/thread.h>
 #include "usbmuxd.h"

 #ifndef ETIMEDOUT
 #define ETIMEDOUT 138
 #endif

 static int debug_level = 0;

 struct client_data {
 	int fd;
 	int sfd;
 	char* udid;
 	enum usbmux_lookup_options lookup_opts;
 	uint16_t device_port;
 };

 #define CDATA_FREE(x) if (x) { \
 	if ((x)->fd > 0) socket_close((x)->fd); \
 	if ((x)->sfd > 0) socket_close((x)->sfd); \
 	free((x)->udid); \
 	free(x); \
 }

 static void *acceptor_thread(void *arg)
 {
 	char buffer[32768];
 	struct client_data *cdata = (struct client_data*)arg;
 	usbmuxd_device_info_t *dev_list = NULL;
 	usbmuxd_device_info_t *dev = NULL;
 	usbmuxd_device_info_t muxdev;
 	int count;

 	if (!cdata) {
 		fprintf(stderr, "invalid client_data provided!\n");
 		return NULL;
 	}

 	if (cdata->udid) {
 		if (usbmuxd_get_device(cdata->udid, &muxdev, cdata->lookup_opts) > 0) {
 			dev = &muxdev;
 		}
 	} else {
 		if ((count = usbmuxd_get_device_list(&dev_list)) < 0) {
 			printf("Connecting to usbmuxd failed, terminating.\n");
 			free(dev_list);
 			CDATA_FREE(cdata);
 			return NULL;
 		}

 		if (dev_list == NULL || dev_list[0].handle == 0) {
 			printf("No connected device found, terminating.\n");
 			free(dev_list);
 			CDATA_FREE(cdata);
 			return NULL;
 		}

 		int i;
 		for (i = 0; i < count; i++) {
 			if (dev_list[i].conn_type == CONNECTION_TYPE_USB && (cdata->lookup_opts & DEVICE_LOOKUP_USBMUX)) {
 				dev = &(dev_list[i]);
 				break;
 			}
 			if (dev_list[i].conn_type == CONNECTION_TYPE_NETWORK && (cdata->lookup_opts & DEVICE_LOOKUP_NETWORK)) {
 				dev = &(dev_list[i]);
 				break;
 			}
 		}
 	}

 	if (dev == NULL || dev->handle == 0) {
 		printf("No connected/matching device found, disconnecting client.\n");
 		free(dev_list);
 		CDATA_FREE(cdata);
 		return NULL;
 	}

 	cdata->sfd = -1;
 	if (dev->conn_type == CONNECTION_TYPE_NETWORK) {
 		struct sockaddr_storage saddr_storage;
 		struct sockaddr* saddr = (struct sockaddr*)&saddr_storage;

 		if (dev->conn_data[1] == 0x02) { // AF_INET
 			saddr->sa_family = AF_INET;
 			memcpy(&saddr->sa_data[0], (uint8_t*)dev->conn_data+2, 14);
 		}
 		else if (dev->conn_data[1] == 0x1E) { //AF_INET6 (bsd)
 #ifdef AF_INET6
 			saddr->sa_family = AF_INET6;
 			/* copy the address and the host dependent scope id */
 			memcpy(&saddr->sa_data[0], (uint8_t*)dev->conn_data+2, 26);
 #else
 			fprintf(stderr, "ERROR: Got an IPv6 address but this system doesn't support IPv6\n");
 			CDATA_FREE(cdata);
 			return NULL;
 #endif
 		}
 		else {
 			fprintf(stderr, "Unsupported address family 0x%02x\n", dev->conn_data[1]);
 			CDATA_FREE(cdata);
 			return NULL;
 		}
 		char addrtxt[48];
 		addrtxt[0] = '\0';
 		if (!socket_addr_to_string(saddr, addrtxt, sizeof(addrtxt))) {
 			fprintf(stderr, "Failed to convert network address: %d (%s)\n", errno, strerror(errno));
 		}
 		fprintf(stdout, "Requesting connection to NETWORK device %s (serial: %s), port %d\n", addrtxt, dev->udid, cdata->device_port);
 		cdata->sfd = socket_connect_addr(saddr, cdata->device_port);
 	} else if (dev->conn_type == CONNECTION_TYPE_USB) {
 		fprintf(stdout, "Requesting connection to USB device handle %d (serial: %s), port %d\n", dev->handle, dev->udid, cdata->device_port);

 		cdata->sfd = usbmuxd_connect(dev->handle, cdata->device_port);
 	}
 	free(dev_list);
 	if (cdata->sfd < 0) {
 		fprintf(stderr, "Error connecting to device: %s\n", strerror(errno));
 	} else {
 		fd_set fds;
 		FD_ZERO(&fds);
 		FD_SET(cdata->fd, &fds);
 		FD_SET(cdata->sfd, &fds);
 		int maxfd = cdata->fd > cdata->sfd ? cdata->fd : cdata->sfd;

 		while (1) {
 			fd_set read_fds = fds;
 			int ret_sel = select(maxfd+1, &read_fds, NULL, NULL, NULL);
 			if (ret_sel < 0) {
 				perror("select");
 				break;
 			}
 			if (FD_ISSET(cdata->fd, &read_fds)) {
 				int r = socket_receive_timeout(cdata->fd, buffer, sizeof(buffer), 0, 100);
 				if (r <= 0) {
 					break;
 				}
 				int sent = 0;
 				while (sent < r) {
 					int s = socket_send(cdata->sfd, buffer+sent, r-sent);
 					if (s <= 0) {
 						break;
 					}
 					sent += s;
 				}
 			}
 			if (FD_ISSET(cdata->sfd, &read_fds)) {
 				int r = socket_receive_timeout(cdata->sfd, buffer, sizeof(buffer), 0, 100);
 				if (r <= 0) {
 					break;
 				}
 				int sent = 0;
 				while (sent < r) {
 					int s = socket_send(cdata->fd, buffer+sent, r-sent);
 					if (s <= 0) {
 						break;
 					}
 					sent += s;
 				}
 			}
 		}
 	}

 	CDATA_FREE(cdata);

 	return NULL;
 }

 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] LOCAL_PORT:DEVICE_PORT [LOCAL_PORT2:DEVICE_PORT2 ...]\n", (name ? name+1 : argv[0]));
 	fprintf(is_error ? stderr : stdout,
 		"\n" \
 		"Proxy that binds local TCP ports to be forwarded to the specified ports on a usbmux device.\n" \
 		"\n" \
 		"OPTIONS:\n" \
 		"  -u, --udid UDID    target specific device by UDID\n" \
 		"  -n, --network      connect to network device\n" \
 		"  -l, --local        connect to USB device (default)\n" \
 		"  -s, --source ADDR  source address for listening socket (default 127.0.0.1)\n" \
 		"  -h, --help         prints usage information\n" \
 		"  -d, --debug        increase debug level\n" \
 		"  -v, --version      prints version information\n" \
 		"\n" \
 		"Homepage:    <" PACKAGE_URL ">\n"
 		"Bug Reports: <" PACKAGE_BUGREPORT ">\n"
 	);
 }

 int main(int argc, char **argv)
 {
 	char* device_udid = NULL;
 	char* source_addr = NULL;
 	uint16_t listen_port[16];
 	uint16_t device_port[16];
 #ifdef AF_INET6
 #define MAX_LISTEN_NUM 32
 #else
 #define MAX_LISTEN_NUM 16
 #endif
 	struct listen_sock {
 		int fd;
 		int index;
 	} listen_sock[MAX_LISTEN_NUM];
 	int num_listen = 0;
 	int num_pairs = 0;
 	int i = 0;
 	enum usbmux_lookup_options lookup_opts = 0;

 	const struct option longopts[] = {
 		{ "debug", no_argument, NULL, 'd' },
 		{ "help", no_argument, NULL, 'h' },
 		{ "udid", required_argument, NULL, 'u' },
 		{ "local", no_argument, NULL, 'l' },
 		{ "network", no_argument, NULL, 'n' },
 		{ "source", required_argument, NULL, 's' },
 		{ "version", no_argument, NULL, 'v' },
 		{ NULL, 0, NULL, 0}
 	};
 	int c = 0;
 	while ((c = getopt_long(argc, argv, "dhu:lns:v", longopts, NULL)) != -1) {
 		switch (c) {
 		case 'd':
 			libusbmuxd_set_debug_level(++debug_level);
 			break;
 		case 'u':
 			if (!*optarg) {
 				fprintf(stderr, "ERROR: UDID must not be empty!\n");
 				print_usage(argc, argv, 1);
 				return 2;
 			}
 			free(device_udid);
 			device_udid = strdup(optarg);
 			break;
 		case 'l':
 			lookup_opts |= DEVICE_LOOKUP_USBMUX;
 			break;
 		case 'n':
 			lookup_opts |= DEVICE_LOOKUP_NETWORK;
 			break;
 		case 's':
 			if (!*optarg) {
 				fprintf(stderr, "ERROR: source address must not be empty!\n");
 				print_usage(argc, argv, 1);
 				return 2;
 			}
 			free(source_addr);
 			source_addr = strdup(optarg);
 			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 (lookup_opts == 0) {
 		lookup_opts = DEVICE_LOOKUP_USBMUX;
 	}

 	argc -= optind;
 	argv += optind;

 	if (argc == 0) {
 		fprintf(stderr, "ERROR: Not enough parameters. Need at least one pair of ports.\n");
 		print_usage(argc + optind, argv - optind, 1);
 		free(device_udid);
 		free(source_addr);
 		return 2;
 	}

 	if (argc == 2 && (strchr(argv[0], ':') == NULL) && (strchr(argv[1], ':') == NULL)) {
 		/* support old-style port pair specification */
 		char* endp = NULL;
 		listen_port[0] = (uint16_t)strtol(argv[0], &endp, 10);
 		if (!listen_port[0] || *endp != '\0') {
 			fprintf(stderr, "Invalid listen port specified in argument '%s'!\n", argv[0]);
 			free(device_udid);
 			free(source_addr);
 			return -EINVAL;
 		}
 		endp = NULL;
 		device_port[0] = (uint16_t)strtol(argv[1], &endp, 10);
 		if (!device_port[0] || *endp != '\0') {
 			fprintf(stderr, "Invalid device port specified in argument '%s'!\n", argv[1]);
 			free(device_udid);
 			free(source_addr);
 			return -EINVAL;
 		}
 		num_pairs = 1;
 	} else {
 		/* new style, colon-separated local:device port pairs */
 		for (i = 0; i < argc; i++) {
 			char* endp = NULL;
 			listen_port[i] = (uint16_t)strtol(argv[i], &endp, 10);
 			if (!listen_port[i] || (*endp != ':')) {
 				fprintf(stderr, "Invalid listen port specified in argument '%s'!\n", argv[i]);
 				free(device_udid);
 				free(source_addr);
 				return -EINVAL;
 			}
 			device_port[i] = (uint16_t)strtol(endp+1, &endp, 10);
 			if (!device_port[i] || (*endp != '\0')) {
 				fprintf(stderr, "Invalid device port specified in argument '%s'!\n", argv[i+1]);
 				free(device_udid);
 				free(source_addr);
 				return -EINVAL;
 			}
 		}
 		num_pairs = argc;
 	}

 	if (num_pairs > 16) {
 		fprintf(stderr, "ERROR: Too many LOCAL:DEVICE port pairs. Maximum is 16.\n");
 		return -1;
 	}

 #ifndef WIN32
 	signal(SIGPIPE, SIG_IGN);
 #endif

 	// first create the listening sockets
 	for (i = 0; i < num_pairs; i++) {
 		printf("Creating listening port %d for device port %d\n", listen_port[i], device_port[i]);
 		if (!source_addr) {
 			listen_sock[num_listen].fd = socket_create(NULL, listen_port[i]);
 			if (listen_sock[num_listen].fd < 0) {
 				int j;
 				fprintf(stderr, "Error creating socket for listen port %u: %s\n", listen_port[i], strerror(errno));
 				free(source_addr);
 				free(device_udid);
 				for (j = num_listen; j >= 0; j--) {
 					socket_close(listen_sock[j].fd);
 				}
 				return -errno;
 			}
 			listen_sock[num_listen].index = i;
 			num_listen++;
 		} else {
 			listen_sock[num_listen].fd = socket_create(source_addr, listen_port[i]);
 			if (listen_sock[num_listen].fd < 0) {
 				int j;
 				fprintf(stderr, "Error creating socket for listen port %u: %s\n", listen_port[i], strerror(errno));
 				free(source_addr);
 				free(device_udid);
 				for (j = num_listen; j >= 0; j--) {
 					socket_close(listen_sock[j].fd);
 				}
 				return -errno;
 			}
 			listen_sock[num_listen].index = i;
 			num_listen++;
 		}
 	}

 	// make them non-blocking and add them to fd set
 	fd_set fds;
 	FD_ZERO(&fds);
 	for (i = 0; i < num_listen; i++) {
 #ifdef WIN32
 		u_long l_yes = 1;
 		ioctlsocket(listen_sock[i].fd, FIONBIO, &l_yes);
 #else
 		int flags = fcntl(listen_sock[i].fd, F_GETFL, 0);
 		fcntl(listen_sock[i].fd, F_SETFL, flags | O_NONBLOCK);
 #endif
 		FD_SET(listen_sock[i].fd, &fds);
 	}

 	// main loop
 	while (1) {
 		printf("waiting for connection\n");
 		fd_set read_fds = fds;
 		int ret_sel = select(listen_sock[num_listen-1].fd+1, &read_fds, NULL, NULL, NULL);
 		if (ret_sel < 0) {
 			perror("select");
 			break;
 		}
 		for (i = 0; i < num_listen; i++) {
 			if (FD_ISSET(listen_sock[i].fd, &read_fds)) {
 				THREAD_T acceptor = THREAD_T_NULL;
 				struct client_data *cdata;
 				int c_sock = socket_accept(listen_sock[i].fd, listen_port[listen_sock[i].index]);
 				if (c_sock < 0) {
 					fprintf(stderr, "accept: %s\n", strerror(errno));
 					break;
 				}
 				printf("New connection for %d->%d, fd = %d\n", listen_port[listen_sock[i].index], device_port[listen_sock[i].index], c_sock);
 				cdata = (struct client_data*)malloc(sizeof(struct client_data));
 				if (!cdata) {
 					socket_close(c_sock);
 					fprintf(stderr, "ERROR: Out of memory\n");
 					free(device_udid);
 					return -1;
 				}
 				cdata->fd = c_sock;
 				cdata->sfd = -1;
 				cdata->udid = (device_udid) ? strdup(device_udid) : NULL;
 				cdata->lookup_opts = lookup_opts;
 				cdata->device_port = device_port[listen_sock[i].index];

 				if (thread_new(&acceptor, acceptor_thread, cdata) == 0) {
 					thread_detach(acceptor);
 				} else {
 					fprintf(stderr, "ERROR: Failed to created acceptor thread!\n");
 				}
 			}
 		}
 	}

 	for (i = 0; i < num_listen; i++) {
 		socket_close(listen_sock[i].fd);
 	}

 	free(device_udid);
 	free(source_addr);

 	return 0;
 }
	/*
	* iproxy.c -- proxy that enables tcp service access to iOS devices
	*
	* Copyright (C) 2009-2020 Nikias Bassen <nikias@gmx.li>
	* Copyright (C) 2014 Martin Szulecki <m.szulecki@libimobiledevice.org>
	* Copyright (C) 2009 Paul Sladen <libiphone@paul.sladen.org>
	*
	* Based upon iTunnel source code, Copyright (c) 2008 Jing Su.
	* http://www.cs.toronto.edu/~jingsu/itunnel/
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program 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 General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; 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 "iproxy"

	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <fcntl.h>
	#include <stddef.h>
	#include <unistd.h>
	#include <errno.h>
	#include <getopt.h>
	#ifdef WIN32
	#include <winsock2.h>
	#include <windows.h>
	typedef unsigned int socklen_t;
	#else
	#include <sys/select.h>
	#include <sys/socket.h>
	#include <signal.h>
	#endif
	#include <libimobiledevice-glue/socket.h>
	#include <libimobiledevice-glue/thread.h>
	#include "usbmuxd.h"

	#ifndef ETIMEDOUT
	#define ETIMEDOUT 138
	#endif

	static int debug_level = 0;

	struct client_data {
	int fd;
	int sfd;
	char* udid;
	enum usbmux_lookup_options lookup_opts;
	uint16_t device_port;
	};

	#define CDATA_FREE(x) if (x) { \
	if ((x)->fd > 0) socket_close((x)->fd); \
	if ((x)->sfd > 0) socket_close((x)->sfd); \
	free((x)->udid); \
	free(x); \
	}

	static void acceptor_thread(void arg)
	{
	char buffer[32768];
	struct client_data cdata = (struct client_data)arg;
	usbmuxd_device_info_t *dev_list = NULL;
	usbmuxd_device_info_t *dev = NULL;
	usbmuxd_device_info_t muxdev;
	int count;

	if (!cdata) {
	fprintf(stderr, "invalid client_data provided!\n");
	return NULL;
	}

	if (cdata->udid) {
	if (usbmuxd_get_device(cdata->udid, &muxdev, cdata->lookup_opts) > 0) {
	dev = &muxdev;
	}
	} else {
	if ((count = usbmuxd_get_device_list(&dev_list)) < 0) {
	printf("Connecting to usbmuxd failed, terminating.\n");
	free(dev_list);
	CDATA_FREE(cdata);
	return NULL;
	}

	if (dev_list == NULL \|\| dev_list[0].handle == 0) {
	printf("No connected device found, terminating.\n");
	free(dev_list);
	CDATA_FREE(cdata);
	return NULL;
	}

	int i;
	for (i = 0; i < count; i++) {
	if (dev_list[i].conn_type == CONNECTION_TYPE_USB && (cdata->lookup_opts & DEVICE_LOOKUP_USBMUX)) {
	dev = &(dev_list[i]);
	break;
	}
	if (dev_list[i].conn_type == CONNECTION_TYPE_NETWORK && (cdata->lookup_opts & DEVICE_LOOKUP_NETWORK)) {
	dev = &(dev_list[i]);
	break;
	}
	}
	}

	if (dev == NULL \|\| dev->handle == 0) {
	printf("No connected/matching device found, disconnecting client.\n");
	free(dev_list);
	CDATA_FREE(cdata);
	return NULL;
	}

	cdata->sfd = -1;
	if (dev->conn_type == CONNECTION_TYPE_NETWORK) {
	struct sockaddr_storage saddr_storage;
	struct sockaddr* saddr = (struct sockaddr*)&saddr_storage;

	if (dev->conn_data[1] == 0x02) { // AF_INET
	saddr->sa_family = AF_INET;
	memcpy(&saddr->sa_data[0], (uint8_t*)dev->conn_data+2, 14);
	}
	else if (dev->conn_data[1] == 0x1E) { //AF_INET6 (bsd)
	#ifdef AF_INET6
	saddr->sa_family = AF_INET6;
	/* copy the address and the host dependent scope id */
	memcpy(&saddr->sa_data[0], (uint8_t*)dev->conn_data+2, 26);
	#else
	fprintf(stderr, "ERROR: Got an IPv6 address but this system doesn't support IPv6\n");
	CDATA_FREE(cdata);
	return NULL;
	#endif
	}
	else {
	fprintf(stderr, "Unsupported address family 0x%02x\n", dev->conn_data[1]);
	CDATA_FREE(cdata);
	return NULL;
	}
	char addrtxt[48];
	addrtxt[0] = '\0';
	if (!socket_addr_to_string(saddr, addrtxt, sizeof(addrtxt))) {
	fprintf(stderr, "Failed to convert network address: %d (%s)\n", errno, strerror(errno));
	}
	fprintf(stdout, "Requesting connection to NETWORK device %s (serial: %s), port %d\n", addrtxt, dev->udid, cdata->device_port);
	cdata->sfd = socket_connect_addr(saddr, cdata->device_port);
	} else if (dev->conn_type == CONNECTION_TYPE_USB) {
	fprintf(stdout, "Requesting connection to USB device handle %d (serial: %s), port %d\n", dev->handle, dev->udid, cdata->device_port);

	cdata->sfd = usbmuxd_connect(dev->handle, cdata->device_port);
	}
	free(dev_list);
	if (cdata->sfd < 0) {
	fprintf(stderr, "Error connecting to device: %s\n", strerror(errno));
	} else {
	fd_set fds;
	FD_ZERO(&fds);
	FD_SET(cdata->fd, &fds);
	FD_SET(cdata->sfd, &fds);
	int maxfd = cdata->fd > cdata->sfd ? cdata->fd : cdata->sfd;

	while (1) {
	fd_set read_fds = fds;
	int ret_sel = select(maxfd+1, &read_fds, NULL, NULL, NULL);
	if (ret_sel < 0) {
	perror("select");
	break;
	}
	if (FD_ISSET(cdata->fd, &read_fds)) {
	int r = socket_receive_timeout(cdata->fd, buffer, sizeof(buffer), 0, 100);
	if (r <= 0) {
	break;
	}
	int sent = 0;
	while (sent < r) {
	int s = socket_send(cdata->sfd, buffer+sent, r-sent);
	if (s <= 0) {
	break;
	}
	sent += s;
	}
	}
	if (FD_ISSET(cdata->sfd, &read_fds)) {
	int r = socket_receive_timeout(cdata->sfd, buffer, sizeof(buffer), 0, 100);
	if (r <= 0) {
	break;
	}
	int sent = 0;
	while (sent < r) {
	int s = socket_send(cdata->fd, buffer+sent, r-sent);
	if (s <= 0) {
	break;
	}
	sent += s;
	}
	}
	}
	}

	CDATA_FREE(cdata);

	return NULL;
	}

	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] LOCAL_PORT:DEVICE_PORT [LOCAL_PORT2:DEVICE_PORT2 ...]\n", (name ? name+1 : argv[0]));
	fprintf(is_error ? stderr : stdout,
	"\n" \
	"Proxy that binds local TCP ports to be forwarded to the specified ports on a usbmux device.\n" \
	"\n" \
	"OPTIONS:\n" \
	" -u, --udid UDID target specific device by UDID\n" \
	" -n, --network connect to network device\n" \
	" -l, --local connect to USB device (default)\n" \
	" -s, --source ADDR source address for listening socket (default 127.0.0.1)\n" \
	" -h, --help prints usage information\n" \
	" -d, --debug increase debug level\n" \
	" -v, --version prints version information\n" \
	"\n" \
	"Homepage: <" PACKAGE_URL ">\n"
	"Bug Reports: <" PACKAGE_BUGREPORT ">\n"
	);
	}

	int main(int argc, char **argv)
	{
	char* device_udid = NULL;
	char* source_addr = NULL;
	uint16_t listen_port[16];
	uint16_t device_port[16];
	#ifdef AF_INET6
	#define MAX_LISTEN_NUM 32
	#else
	#define MAX_LISTEN_NUM 16
	#endif
	struct listen_sock {
	int fd;
	int index;
	} listen_sock[MAX_LISTEN_NUM];
	int num_listen = 0;
	int num_pairs = 0;
	int i = 0;
	enum usbmux_lookup_options lookup_opts = 0;

	const struct option longopts[] = {
	{ "debug", no_argument, NULL, 'd' },
	{ "help", no_argument, NULL, 'h' },
	{ "udid", required_argument, NULL, 'u' },
	{ "local", no_argument, NULL, 'l' },
	{ "network", no_argument, NULL, 'n' },
	{ "source", required_argument, NULL, 's' },
	{ "version", no_argument, NULL, 'v' },
	{ NULL, 0, NULL, 0}
	};
	int c = 0;
	while ((c = getopt_long(argc, argv, "dhu:lns:v", longopts, NULL)) != -1) {
	switch (c) {
	case 'd':
	libusbmuxd_set_debug_level(++debug_level);
	break;
	case 'u':
	if (!*optarg) {
	fprintf(stderr, "ERROR: UDID must not be empty!\n");
	print_usage(argc, argv, 1);
	return 2;
	}
	free(device_udid);
	device_udid = strdup(optarg);
	break;
	case 'l':
	lookup_opts \|= DEVICE_LOOKUP_USBMUX;
	break;
	case 'n':
	lookup_opts \|= DEVICE_LOOKUP_NETWORK;
	break;
	case 's':
	if (!*optarg) {
	fprintf(stderr, "ERROR: source address must not be empty!\n");
	print_usage(argc, argv, 1);
	return 2;
	}
	free(source_addr);
	source_addr = strdup(optarg);
	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 (lookup_opts == 0) {
	lookup_opts = DEVICE_LOOKUP_USBMUX;
	}

	argc -= optind;
	argv += optind;

	if (argc == 0) {
	fprintf(stderr, "ERROR: Not enough parameters. Need at least one pair of ports.\n");
	print_usage(argc + optind, argv - optind, 1);
	free(device_udid);
	free(source_addr);
	return 2;
	}

	if (argc == 2 && (strchr(argv[0], ':') == NULL) && (strchr(argv[1], ':') == NULL)) {
	/* support old-style port pair specification */
	char* endp = NULL;
	listen_port[0] = (uint16_t)strtol(argv[0], &endp, 10);
	if (!listen_port[0] \|\| *endp != '\0') {
	fprintf(stderr, "Invalid listen port specified in argument '%s'!\n", argv[0]);
	free(device_udid);
	free(source_addr);
	return -EINVAL;
	}
	endp = NULL;
	device_port[0] = (uint16_t)strtol(argv[1], &endp, 10);
	if (!device_port[0] \|\| *endp != '\0') {
	fprintf(stderr, "Invalid device port specified in argument '%s'!\n", argv[1]);
	free(device_udid);
	free(source_addr);
	return -EINVAL;
	}
	num_pairs = 1;
	} else {
	/* new style, colon-separated local:device port pairs */
	for (i = 0; i < argc; i++) {
	char* endp = NULL;
	listen_port[i] = (uint16_t)strtol(argv[i], &endp, 10);
	if (!listen_port[i] \|\| (*endp != ':')) {
	fprintf(stderr, "Invalid listen port specified in argument '%s'!\n", argv[i]);
	free(device_udid);
	free(source_addr);
	return -EINVAL;
	}
	device_port[i] = (uint16_t)strtol(endp+1, &endp, 10);
	if (!device_port[i] \|\| (*endp != '\0')) {
	fprintf(stderr, "Invalid device port specified in argument '%s'!\n", argv[i+1]);
	free(device_udid);
	free(source_addr);
	return -EINVAL;
	}
	}
	num_pairs = argc;
	}

	if (num_pairs > 16) {
	fprintf(stderr, "ERROR: Too many LOCAL:DEVICE port pairs. Maximum is 16.\n");
	return -1;
	}

	#ifndef WIN32
	signal(SIGPIPE, SIG_IGN);
	#endif

	// first create the listening sockets
	for (i = 0; i < num_pairs; i++) {
	printf("Creating listening port %d for device port %d\n", listen_port[i], device_port[i]);
	if (!source_addr) {
	listen_sock[num_listen].fd = socket_create(NULL, listen_port[i]);
	if (listen_sock[num_listen].fd < 0) {
	int j;
	fprintf(stderr, "Error creating socket for listen port %u: %s\n", listen_port[i], strerror(errno));
	free(source_addr);
	free(device_udid);
	for (j = num_listen; j >= 0; j--) {
	socket_close(listen_sock[j].fd);
	}
	return -errno;
	}
	listen_sock[num_listen].index = i;
	num_listen++;
	} else {
	listen_sock[num_listen].fd = socket_create(source_addr, listen_port[i]);
	if (listen_sock[num_listen].fd < 0) {
	int j;
	fprintf(stderr, "Error creating socket for listen port %u: %s\n", listen_port[i], strerror(errno));
	free(source_addr);
	free(device_udid);
	for (j = num_listen; j >= 0; j--) {
	socket_close(listen_sock[j].fd);
	}
	return -errno;
	}
	listen_sock[num_listen].index = i;
	num_listen++;
	}
	}

	// make them non-blocking and add them to fd set
	fd_set fds;
	FD_ZERO(&fds);
	for (i = 0; i < num_listen; i++) {
	#ifdef WIN32
	u_long l_yes = 1;
	ioctlsocket(listen_sock[i].fd, FIONBIO, &l_yes);
	#else
	int flags = fcntl(listen_sock[i].fd, F_GETFL, 0);
	fcntl(listen_sock[i].fd, F_SETFL, flags \| O_NONBLOCK);
	#endif
	FD_SET(listen_sock[i].fd, &fds);
	}

	// main loop
	while (1) {
	printf("waiting for connection\n");
	fd_set read_fds = fds;
	int ret_sel = select(listen_sock[num_listen-1].fd+1, &read_fds, NULL, NULL, NULL);
	if (ret_sel < 0) {
	perror("select");
	break;
	}
	for (i = 0; i < num_listen; i++) {
	if (FD_ISSET(listen_sock[i].fd, &read_fds)) {
	THREAD_T acceptor = THREAD_T_NULL;
	struct client_data *cdata;
	int c_sock = socket_accept(listen_sock[i].fd, listen_port[listen_sock[i].index]);
	if (c_sock < 0) {
	fprintf(stderr, "accept: %s\n", strerror(errno));
	break;
	}
	printf("New connection for %d->%d, fd = %d\n", listen_port[listen_sock[i].index], device_port[listen_sock[i].index], c_sock);
	cdata = (struct client_data*)malloc(sizeof(struct client_data));
	if (!cdata) {
	socket_close(c_sock);
	fprintf(stderr, "ERROR: Out of memory\n");
	free(device_udid);
	return -1;
	}
	cdata->fd = c_sock;
	cdata->sfd = -1;
	cdata->udid = (device_udid) ? strdup(device_udid) : NULL;
	cdata->lookup_opts = lookup_opts;
	cdata->device_port = device_port[listen_sock[i].index];

	if (thread_new(&acceptor, acceptor_thread, cdata) == 0) {
	thread_detach(acceptor);
	} else {
	fprintf(stderr, "ERROR: Failed to created acceptor thread!\n");
	}
	}
	}
	}

	for (i = 0; i < num_listen; i++) {
	socket_close(listen_sock[i].fd);
	}

	free(device_udid);
	free(source_addr);

	return 0;
	}