[thirdparty/util-linux.git] / sys-utils / unshare.c

/*
 * unshare(1) - command-line interface for unshare(2)
 *
 * Copyright (C) 2009 Mikhail Gusarov <dottedmag@dottedmag.net>
 *
 * 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, 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.,
 * 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <errno.h>
#include <getopt.h>
#include <sched.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include "nls.h"
#include "c.h"

#ifndef CLONE_NEWSNS
# define CLONE_NEWNS 0x00020000
#endif
#ifndef CLONE_NEWUTS
# define CLONE_NEWUTS 0x04000000
#endif
#ifndef CLONE_NEWIPC
# define CLONE_NEWIPC 0x08000000
#endif
#ifndef CLONE_NEWNET
# define CLONE_NEWNET 0x40000000
#endif

#ifndef HAVE_UNSHARE
# include <sys/syscall.h>

static int unshare(int flags)
{
	return syscall(SYS_unshare, flags);
}
#endif

static void usage(int status)
{
	FILE *out = status == EXIT_SUCCESS ? stdout : stderr;

	fprintf(out, _("Usage: %s [options] <program> [args...]\n"),
		program_invocation_short_name);

	fputs(_("Run program with some namespaces unshared from parent\n\n"
		"  -h, --help        usage information (this)\n"
		"  -m, --mount       unshare mounts namespace\n"
		"  -u, --uts         unshare UTS namespace (hostname etc)\n"
		"  -i, --ipc         unshare System V IPC namespace\n"
		"  -n, --net         unshare network namespace\n"), out);

	fprintf(out, _("\nFor more information see unshare(1).\n"));
	exit(status);
}

int main(int argc, char *argv[])
{
	struct option longopts[] = {
		{ "help", no_argument, 0, 'h' },
		{ "mount", no_argument, 0, 'm' },
		{ "uts", no_argument, 0, 'u' },
		{ "ipc", no_argument, 0, 'i' },
		{ "net", no_argument, 0, 'n' },
		{ NULL, 0, 0, 0 }
	};

	int unshare_flags = 0;

	int c;

	setlocale(LC_MESSAGES, "");
	bindtextdomain(PACKAGE, LOCALEDIR);
	textdomain(PACKAGE);

	while((c = getopt_long(argc, argv, "hmuin", longopts, NULL)) != -1) {
		switch(c) {
		case 'h':
			usage(EXIT_SUCCESS);
		case 'm':
			unshare_flags |= CLONE_NEWNS;
			break;
		case 'u':
			unshare_flags |= CLONE_NEWUTS;
			break;
		case 'i':
			unshare_flags |= CLONE_NEWIPC;
			break;
		case 'n':
			unshare_flags |= CLONE_NEWNET;
			break;
		default:
			usage(EXIT_FAILURE);
		}
	}

	if(optind >= argc)
		usage(EXIT_FAILURE);

	if(-1 == unshare(unshare_flags))
		err(EXIT_FAILURE, _("unshare failed"));

	/* drop potential root euid/egid if we had been setuid'd */
	if (setgid(getgid()) < 0)
		err(EXIT_FAILURE, _("cannot set group id"));

	if (setuid(getuid()) < 0)
		err(EXIT_FAILURE, _("cannot set user id"));

	execvp(argv[optind], argv + optind);

	err(EXIT_FAILURE, _("exec %s failed"), argv[optind]);
}
Commit	Line	Data
4205f1fd MG	1	/*
	2	* unshare(1) - command-line interface for unshare(2)
	3	*
	4	* Copyright (C) 2009 Mikhail Gusarov <dottedmag@dottedmag.net>
	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms of the GNU General Public License as published by the
	8	* Free Software Foundation; either version 2, or (at your option) any
	9	* later version.
	10	*
	11	* This program is distributed in the hope that it will be useful, but
	12	* WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	14	* General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License along
	17	* with this program; if not, write to the Free Software Foundation, Inc.,
	18	* 675 Mass Ave, Cambridge, MA 02139, USA.
	19	*/
	20
4205f1fd MG	21	#include <errno.h>
	22	#include <getopt.h>
	23	#include <sched.h>
	24	#include <stdio.h>
	25	#include <stdlib.h>
	26	#include <unistd.h>
	27
	28	#include "nls.h"
eb76ca98	29	#include "c.h"
4205f1fd MG	30
	31	#ifndef CLONE_NEWSNS
	32	# define CLONE_NEWNS 0x00020000
	33	#endif
	34	#ifndef CLONE_NEWUTS
	35	# define CLONE_NEWUTS 0x04000000
	36	#endif
	37	#ifndef CLONE_NEWIPC
	38	# define CLONE_NEWIPC 0x08000000
	39	#endif
	40	#ifndef CLONE_NEWNET
	41	# define CLONE_NEWNET 0x40000000
	42	#endif
	43
	44	#ifndef HAVE_UNSHARE
	45	# include <sys/syscall.h>
	46
	47	static int unshare(int flags)
	48	{
	49	return syscall(SYS_unshare, flags);
	50	}
	51	#endif
	52
	53	static void usage(int status)
	54	{
	55	FILE *out = status == EXIT_SUCCESS ? stdout : stderr;
	56
	57	fprintf(out, _("Usage: %s [options] <program> [args...]\n"),
	58	program_invocation_short_name);
	59
	60	fputs(_("Run program with some namespaces unshared from parent\n\n"
	61	" -h, --help usage information (this)\n"
	62	" -m, --mount unshare mounts namespace\n"
	63	" -u, --uts unshare UTS namespace (hostname etc)\n"
	64	" -i, --ipc unshare System V IPC namespace\n"
	65	" -n, --net unshare network namespace\n"), out);
	66
	67	fprintf(out, _("\nFor more information see unshare(1).\n"));
	68	exit(status);
	69	}
	70
	71	int main(int argc, char *argv[])
	72	{
	73	struct option longopts[] = {
	74	{ "help", no_argument, 0, 'h' },
	75	{ "mount", no_argument, 0, 'm' },
	76	{ "uts", no_argument, 0, 'u' },
	77	{ "ipc", no_argument, 0, 'i' },
	78	{ "net", no_argument, 0, 'n' },
4ffde0b6	79	{ NULL, 0, 0, 0 }
4205f1fd MG	80	};
	81
	82	int unshare_flags = 0;
	83
	84	int c;
	85
	86	setlocale(LC_MESSAGES, "");
	87	bindtextdomain(PACKAGE, LOCALEDIR);
	88	textdomain(PACKAGE);
	89
	90	while((c = getopt_long(argc, argv, "hmuin", longopts, NULL)) != -1) {
	91	switch(c) {
	92	case 'h':
	93	usage(EXIT_SUCCESS);
	94	case 'm':
	95	unshare_flags \|= CLONE_NEWNS;
	96	break;
	97	case 'u':
	98	unshare_flags \|= CLONE_NEWUTS;
	99	break;
	100	case 'i':
	101	unshare_flags \|= CLONE_NEWIPC;
	102	break;
	103	case 'n':
	104	unshare_flags \|= CLONE_NEWNET;
	105	break;
	106	default:
	107	usage(EXIT_FAILURE);
	108	}
	109	}
	110
	111	if(optind >= argc)
	112	usage(EXIT_FAILURE);
	113
	114	if(-1 == unshare(unshare_flags))
	115	err(EXIT_FAILURE, _("unshare failed"));
	116
3f1be691 KZ	117	/* drop potential root euid/egid if we had been setuid'd */
	118	if (setgid(getgid()) < 0)
	119	err(EXIT_FAILURE, _("cannot set group id"));
	120
	121	if (setuid(getuid()) < 0)
	122	err(EXIT_FAILURE, _("cannot set user id"));
	123
4205f1fd MG	124	execvp(argv[optind], argv + optind);
	125
	126	err(EXIT_FAILURE, _("exec %s failed"), argv[optind]);
	127	}