[mirror_zfs-debian.git] / cmd / mount_zfs / mount_zfs.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2011 Lawrence Livermore National Security, LLC.
 */

#include <libintl.h>
#include <unistd.h>
#include <sys/file.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <libzfs.h>
#include <locale.h>
#ifdef HAVE_LIBSELINUX
#include <selinux/selinux.h>
#endif /* HAVE_LIBSELINUX */

libzfs_handle_t *g_zfs;

typedef struct option_map {
	const char *name;
	unsigned long mntmask;
	unsigned long zfsmask;
} option_map_t;

static const option_map_t option_map[] = {
	/* Canonicalized filesystem independent options from mount(8) */
	{ MNTOPT_NOAUTO,	MS_COMMENT,	ZS_COMMENT	},
	{ MNTOPT_DEFAULTS,	MS_COMMENT,	ZS_COMMENT	},
	{ MNTOPT_NODEVICES,	MS_NODEV,	ZS_COMMENT	},
	{ MNTOPT_DIRSYNC,	MS_DIRSYNC,	ZS_COMMENT	},
	{ MNTOPT_NOEXEC,	MS_NOEXEC,	ZS_COMMENT	},
	{ MNTOPT_GROUP,		MS_GROUP,	ZS_COMMENT	},
	{ MNTOPT_NETDEV,	MS_COMMENT,	ZS_COMMENT	},
	{ MNTOPT_NOFAIL,	MS_COMMENT,	ZS_COMMENT	},
	{ MNTOPT_NOSUID,	MS_NOSUID,	ZS_COMMENT	},
	{ MNTOPT_OWNER,		MS_OWNER,	ZS_COMMENT	},
	{ MNTOPT_REMOUNT,	MS_REMOUNT,	ZS_COMMENT	},
	{ MNTOPT_RO,		MS_RDONLY,	ZS_COMMENT	},
	{ MNTOPT_RW,		MS_COMMENT,	ZS_COMMENT	},
	{ MNTOPT_SYNC,		MS_SYNCHRONOUS,	ZS_COMMENT	},
	{ MNTOPT_USER,		MS_USERS,	ZS_COMMENT	},
	{ MNTOPT_USERS,		MS_USERS,	ZS_COMMENT	},
#ifdef MS_NOATIME
	{ MNTOPT_NOATIME,	MS_NOATIME,	ZS_COMMENT	},
#endif
#ifdef MS_NODIRATIME
	{ MNTOPT_NODIRATIME,	MS_NODIRATIME,	ZS_COMMENT	},
#endif
#ifdef MS_RELATIME
	{ MNTOPT_RELATIME,	MS_RELATIME,	ZS_COMMENT	},
#endif
#ifdef MS_STRICTATIME
	{ MNTOPT_DFRATIME,	MS_STRICTATIME,	ZS_COMMENT	},
#endif
	{ MNTOPT_CONTEXT,	MS_COMMENT,	ZS_NOCONTEXT	},
	{ MNTOPT_NOCONTEXT,	MS_COMMENT,	ZS_NOCONTEXT	},
	{ MNTOPT_FSCONTEXT,	MS_COMMENT,	ZS_NOCONTEXT	},
	{ MNTOPT_DEFCONTEXT,	MS_COMMENT,	ZS_NOCONTEXT	},
	{ MNTOPT_ROOTCONTEXT,	MS_COMMENT,	ZS_NOCONTEXT	},
#ifdef MS_I_VERSION
	{ MNTOPT_IVERSION,	MS_I_VERSION,	ZS_COMMENT	},
#endif
#ifdef MS_MANDLOCK
	{ MNTOPT_NBMAND,	MS_MANDLOCK,	ZS_COMMENT	},
#endif
	/* Valid options not found in mount(8) */
	{ MNTOPT_BIND,		MS_BIND,	ZS_COMMENT	},
#ifdef MS_REC
	{ MNTOPT_RBIND,		MS_BIND|MS_REC,	ZS_COMMENT	},
#endif
	{ MNTOPT_COMMENT,	MS_COMMENT,	ZS_COMMENT	},
#ifdef MS_NOSUB
	{ MNTOPT_NOSUB,		MS_NOSUB,	ZS_COMMENT	},
#endif
#ifdef MS_SILENT
	{ MNTOPT_QUIET,		MS_SILENT,	ZS_COMMENT	},
#endif
	/* Custom zfs options */
	{ MNTOPT_XATTR,		MS_COMMENT,	ZS_COMMENT	},
	{ MNTOPT_NOXATTR,	MS_COMMENT,	ZS_COMMENT	},
	{ MNTOPT_ZFSUTIL,	MS_COMMENT,	ZS_ZFSUTIL	},
	{ NULL,			0,		0		} };

/*
 * Break the mount option in to a name/value pair.  The name is
 * validated against the option map and mount flags set accordingly.
 */
static int
parse_option(char *mntopt, unsigned long *mntflags,
    unsigned long *zfsflags, int sloppy)
{
	const option_map_t *opt;
	char *ptr, *name, *value = NULL;
	int error = 0;

	name = strdup(mntopt);
	if (name == NULL)
		return (ENOMEM);

	for (ptr = name; ptr && *ptr; ptr++) {
		if (*ptr == '=') {
			*ptr = '\0';
			value = ptr+1;
			VERIFY3P(value, !=, NULL);
			break;
		}
	}

	for (opt = option_map; opt->name != NULL; opt++) {
		if (strncmp(name, opt->name, strlen(name)) == 0) {
			*mntflags |= opt->mntmask;
			*zfsflags |= opt->zfsmask;

			/* MS_USERS implies default user options */
			if (opt->mntmask & (MS_USERS))
				*mntflags |= (MS_NOEXEC|MS_NOSUID|MS_NODEV);

			/* MS_OWNER|MS_GROUP imply default owner options */
			if (opt->mntmask & (MS_OWNER | MS_GROUP))
				*mntflags |= (MS_NOSUID|MS_NODEV);

			error = 0;
			goto out;
		}
	}

	if (!sloppy)
		error = ENOENT;
out:
	/* If required further process on the value may be done here */
	free(name);
	return (error);
}

/*
 * Translate the mount option string in to MS_* mount flags for the
 * kernel vfs.  When sloppy is non-zero unknown options will be ignored
 * otherwise they are considered fatal are copied in to badopt.
 */
static int
parse_options(char *mntopts, unsigned long *mntflags, unsigned long *zfsflags,
    int sloppy, char *badopt, char *mtabopt)
{
	int error = 0, quote = 0, flag = 0, count = 0;
	char *ptr, *opt, *opts;

	opts = strdup(mntopts);
	if (opts == NULL)
		return (ENOMEM);

	*mntflags = 0;
	opt = NULL;

	/*
	 * Scan through all mount options which must be comma delimited.
	 * We must be careful to notice regions which are double quoted
	 * and skip commas in these regions.  Each option is then checked
	 * to determine if it is a known option.
	 */
	for (ptr = opts; ptr && !flag; ptr++) {
		if (opt == NULL)
			opt = ptr;

		if (*ptr == '"')
			quote = !quote;

		if (quote)
			continue;

		if (*ptr == '\0')
			flag = 1;

		if ((*ptr == ',') || (*ptr == '\0')) {
			*ptr = '\0';

			error = parse_option(opt, mntflags, zfsflags, sloppy);
			if (error) {
				strcpy(badopt, opt);
				goto out;

			}

			if (!(*mntflags & MS_REMOUNT) &&
			    !(*zfsflags & ZS_ZFSUTIL)) {
				if (count > 0)
					strlcat(mtabopt, ",", MNT_LINE_MAX);

				strlcat(mtabopt, opt, MNT_LINE_MAX);
				count++;
			}

			opt = NULL;
		}
	}

out:
	free(opts);
	return (error);
}

/*
 * If a file or directory in your current working directory is named
 * 'dataset' then mount(8) will prepend your current working directory
 * to dataset.  The is no way to prevent this behavior so we simply
 * check for it and strip the prepended patch when it is added.
 */
static char *
parse_dataset(char *dataset)
{
	char cwd[PATH_MAX];
	int len;

	if (getcwd(cwd, PATH_MAX) == NULL)
		return (dataset);

	len = strlen(cwd);

	/* Do not add one when cwd already ends in a trailing '/' */
	if (!strncmp(cwd, dataset, len))
		return (dataset + len + (cwd[len-1] != '/'));

	return (dataset);
}

/*
 * Update the mtab_* code to use the libmount library when it is commonly
 * available otherwise fallback to legacy mode.  The mount(8) utility will
 * manage the lock file for us to prevent racing updates to /etc/mtab.
 */
static int
mtab_is_writeable(void)
{
	struct stat st;
	int error, fd;

	error = lstat(MNTTAB, &st);
	if (error || S_ISLNK(st.st_mode))
		return (0);

	fd = open(MNTTAB, O_RDWR | O_CREAT, 0644);
	if (fd < 0)
		return (0);

	close(fd);
	return (1);
}

static int
mtab_update(char *dataset, char *mntpoint, char *type, char *mntopts)
{
	struct mntent mnt;
	FILE *fp;
	int error;

	mnt.mnt_fsname = dataset;
	mnt.mnt_dir = mntpoint;
	mnt.mnt_type = type;
	mnt.mnt_opts = mntopts ? mntopts : "";
	mnt.mnt_freq = 0;
	mnt.mnt_passno = 0;

	fp = setmntent(MNTTAB, "a+");
	if (!fp) {
		(void) fprintf(stderr, gettext(
		    "filesystem '%s' was mounted, but %s "
		    "could not be opened due to error %d\n"),
		    dataset, MNTTAB, errno);
		return (MOUNT_FILEIO);
	}

	error = addmntent(fp, &mnt);
	if (error) {
		(void) fprintf(stderr, gettext(
		    "filesystem '%s' was mounted, but %s "
		    "could not be updated due to error %d\n"),
		    dataset, MNTTAB, errno);
		return (MOUNT_FILEIO);
	}

	(void) endmntent(fp);

	return (MOUNT_SUCCESS);
}

int
main(int argc, char **argv)
{
	zfs_handle_t *zhp;
	char legacy[ZFS_MAXPROPLEN];
	char mntopts[MNT_LINE_MAX] = { '\0' };
	char badopt[MNT_LINE_MAX] = { '\0' };
	char mtabopt[MNT_LINE_MAX] = { '\0' };
	char *dataset, *mntpoint;
	unsigned long mntflags = 0, zfsflags = 0, remount_ro = 0;
	int sloppy = 0, fake = 0, verbose = 0, nomtab = 0, zfsutil = 0;
	int error, c;

	(void) setlocale(LC_ALL, "");
	(void) textdomain(TEXT_DOMAIN);

	opterr = 0;

	/* check options */
	while ((c = getopt(argc, argv, "sfnvo:h?")) != -1) {
		switch (c) {
		case 's':
			sloppy = 1;
			break;
		case 'f':
			fake = 1;
			break;
		case 'n':
			nomtab = 1;
			break;
		case 'v':
			verbose++;
			break;
		case 'o':
			(void) strlcpy(mntopts, optarg, sizeof (mntopts));
			break;
		case 'h':
		case '?':
			(void) fprintf(stderr, gettext("Invalid option '%c'\n"),
			    optopt);
			(void) fprintf(stderr, gettext("Usage: mount.zfs "
			    "[-sfnv] [-o options] <dataset> <mountpoint>\n"));
			return (MOUNT_USAGE);
		}
	}

	argc -= optind;
	argv += optind;

	/* check that we only have two arguments */
	if (argc != 2) {
		if (argc == 0)
			(void) fprintf(stderr, gettext("missing dataset "
			    "argument\n"));
		else if (argc == 1)
			(void) fprintf(stderr,
			    gettext("missing mountpoint argument\n"));
		else
			(void) fprintf(stderr, gettext("too many arguments\n"));
		(void) fprintf(stderr, "usage: mount <dataset> <mountpoint>\n");
		return (MOUNT_USAGE);
	}

	dataset = parse_dataset(argv[0]);
	mntpoint = argv[1];

	/* validate mount options and set mntflags */
	error = parse_options(mntopts, &mntflags, &zfsflags, sloppy,
	    badopt, mtabopt);
	if (error) {
		switch (error) {
		case ENOMEM:
			(void) fprintf(stderr, gettext("filesystem '%s' "
			    "cannot be mounted due to a memory allocation "
			    "failure.\n"), dataset);
			return (MOUNT_SYSERR);
		case ENOENT:
			(void) fprintf(stderr, gettext("filesystem '%s' "
			    "cannot be mounted of due invalid option "
			    "'%s'.\n"), dataset, badopt);
			(void) fprintf(stderr, gettext("Use the '-s' option "
			    "to ignore the bad mount option.\n"));
			return (MOUNT_USAGE);
		default:
			(void) fprintf(stderr, gettext("filesystem '%s' "
			    "cannot be mounted due to internal error %d.\n"),
			    dataset, error);
			return (MOUNT_SOFTWARE);
		}
	}

#ifdef HAVE_LIBSELINUX
	/*
	 * Automatically add the default zfs context when selinux is enabled
	 * and the caller has not specified their own context.  This must be
	 * done until zfs is added to the default selinux policy configuration
	 * as a known filesystem type which supports xattrs.
	 */
        if (is_selinux_enabled() && !(zfsflags & ZS_NOCONTEXT)) {
                (void) strlcat(mntopts, ",context=\"system_u:"
                    "object_r:file_t:s0\"", sizeof (mntopts));
                (void) strlcat(mtabopt, ",context=\"system_u:"
                    "object_r:file_t:s0\"", sizeof (mtabopt));
	}
#endif /* HAVE_LIBSELINUX */


	if (verbose)
		(void) fprintf(stdout, gettext("mount.zfs:\n"
		    "  dataset:    \"%s\"\n  mountpoint: \"%s\"\n"
		    "  mountflags: 0x%lx\n  zfsflags:   0x%lx\n"
		    "  mountopts:  \"%s\"\n  mtabopts:   \"%s\"\n"),
		    dataset, mntpoint, mntflags, zfsflags, mntopts, mtabopt);

	if (mntflags & MS_REMOUNT)
		nomtab = 1;

	if ((mntflags & MS_REMOUNT) && (mntflags & MS_RDONLY))
		remount_ro = 1;

	if (zfsflags & ZS_ZFSUTIL)
		zfsutil = 1;

	if ((g_zfs = libzfs_init()) == NULL)
		return (MOUNT_SYSERR);

	/* try to open the dataset to access the mount point */
	if ((zhp = zfs_open(g_zfs, dataset,
	    ZFS_TYPE_FILESYSTEM | ZFS_TYPE_SNAPSHOT)) == NULL) {
		(void) fprintf(stderr, gettext("filesystem '%s' cannot be "
		    "mounted, unable to open the dataset\n"), dataset);
		libzfs_fini(g_zfs);
		return (MOUNT_USAGE);
	}

	/* treat all snapshots as legacy mount points */
	if (zfs_get_type(zhp) == ZFS_TYPE_SNAPSHOT)
		(void) strlcpy(legacy, ZFS_MOUNTPOINT_LEGACY, ZFS_MAXPROPLEN);
	else
		(void) zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT, legacy,
		    sizeof (legacy), NULL, NULL, 0, B_FALSE);

	zfs_close(zhp);
	libzfs_fini(g_zfs);

	/*
	 * Legacy mount points may only be mounted using 'mount', never using
	 * 'zfs mount'.  However, since 'zfs mount' actually invokes 'mount'
	 * we differentiate the two cases using the 'zfsutil' mount option.
	 * This mount option should only be supplied by the 'zfs mount' util.
	 *
	 * The only exception to the above rule is '-o remount,ro'.  This is
	 * always allowed for non-legacy datasets for rc.sysinit/umountroot
	 * to safely remount the root filesystem and flush its cache.
	 */
	if (zfsutil && !strcmp(legacy, ZFS_MOUNTPOINT_LEGACY)) {
		(void) fprintf(stderr, gettext(
		    "filesystem '%s' cannot be mounted using 'zfs mount'.\n"
		    "Use 'zfs set mountpoint=%s' or 'mount -t zfs %s %s'.\n"
		    "See zfs(8) for more information.\n"),
		   dataset, mntpoint, dataset, mntpoint);
		return (MOUNT_USAGE);
	}

	if (!zfsutil && strcmp(legacy, ZFS_MOUNTPOINT_LEGACY) && !remount_ro) {
		(void) fprintf(stderr, gettext(
		    "filesystem '%s' cannot be mounted using 'mount'.\n"
		    "Use 'zfs set mountpoint=%s' or 'zfs mount %s'.\n"
		    "See zfs(8) for more information.\n"),
		    dataset, "legacy", dataset);
		return (MOUNT_USAGE);
	}

	if (!fake) {
		error = mount(dataset, mntpoint, MNTTYPE_ZFS,
		    mntflags, mntopts);
		if (error) {
			switch (errno) {
			case ENOENT:
				(void) fprintf(stderr, gettext("mount point "
				    "'%s' does not exist\n"), mntpoint);
				return (MOUNT_SYSERR);
			case EBUSY:
				(void) fprintf(stderr, gettext("filesystem "
				    "'%s' is already mounted\n"), dataset);
				return (MOUNT_SYSERR);
			default:
				(void) fprintf(stderr, gettext("filesystem "
				    "'%s' can not be mounted due to error "
				    "%d\n"), dataset, errno);
				return (MOUNT_USAGE);
			}
		}
	}

	if (!nomtab && mtab_is_writeable()) {
		error = mtab_update(dataset, mntpoint, MNTTYPE_ZFS, mtabopt);
		if (error)
			return (error);
	}

	return (MOUNT_SUCCESS);
}
Commit	Line	Data
d53368f6 BB	1	/*
	2	* CDDL HEADER START
	3	*
	4	* The contents of this file are subject to the terms of the
	5	* Common Development and Distribution License (the "License").
	6	* You may not use this file except in compliance with the License.
	7	*
	8	* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
	9	* or http://www.opensolaris.org/os/licensing.
	10	* See the License for the specific language governing permissions
	11	* and limitations under the License.
	12	*
	13	* When distributing Covered Code, include this CDDL HEADER in each
	14	* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
	15	* If applicable, add the following below this CDDL HEADER, with the
	16	* fields enclosed by brackets "[]" replaced with your own identifying
	17	* information: Portions Copyright [yyyy] [name of copyright owner]
	18	*
	19	* CDDL HEADER END
	20	*/
	21
	22	/*
	23	* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
	24	* Copyright (c) 2011 Lawrence Livermore National Security, LLC.
	25	*/
	26
	27	#include <libintl.h>
	28	#include <unistd.h>
	29	#include <sys/file.h>
	30	#include <sys/mount.h>
	31	#include <sys/stat.h>
	32	#include <libzfs.h>
92e91da2	33	#include <locale.h>
d53368f6 BB	34	#ifdef HAVE_LIBSELINUX
	35	#include <selinux/selinux.h>
	36	#endif /* HAVE_LIBSELINUX */
	37
	38	libzfs_handle_t *g_zfs;
	39
	40	typedef struct option_map {
	41	const char *name;
	42	unsigned long mntmask;
	43	unsigned long zfsmask;
	44	} option_map_t;
	45
	46	static const option_map_t option_map[] = {
	47	/* Canonicalized filesystem independent options from mount(8) */
	48	{ MNTOPT_NOAUTO, MS_COMMENT, ZS_COMMENT },
	49	{ MNTOPT_DEFAULTS, MS_COMMENT, ZS_COMMENT },
	50	{ MNTOPT_NODEVICES, MS_NODEV, ZS_COMMENT },
	51	{ MNTOPT_DIRSYNC, MS_DIRSYNC, ZS_COMMENT },
	52	{ MNTOPT_NOEXEC, MS_NOEXEC, ZS_COMMENT },
	53	{ MNTOPT_GROUP, MS_GROUP, ZS_COMMENT },
	54	{ MNTOPT_NETDEV, MS_COMMENT, ZS_COMMENT },
	55	{ MNTOPT_NOFAIL, MS_COMMENT, ZS_COMMENT },
	56	{ MNTOPT_NOSUID, MS_NOSUID, ZS_COMMENT },
	57	{ MNTOPT_OWNER, MS_OWNER, ZS_COMMENT },
	58	{ MNTOPT_REMOUNT, MS_REMOUNT, ZS_COMMENT },
	59	{ MNTOPT_RO, MS_RDONLY, ZS_COMMENT },
	60	{ MNTOPT_RW, MS_COMMENT, ZS_COMMENT },
	61	{ MNTOPT_SYNC, MS_SYNCHRONOUS, ZS_COMMENT },
	62	{ MNTOPT_USER, MS_USERS, ZS_COMMENT },
	63	{ MNTOPT_USERS, MS_USERS, ZS_COMMENT },
	64	#ifdef MS_NOATIME
	65	{ MNTOPT_NOATIME, MS_NOATIME, ZS_COMMENT },
	66	#endif
	67	#ifdef MS_NODIRATIME
	68	{ MNTOPT_NODIRATIME, MS_NODIRATIME, ZS_COMMENT },
	69	#endif
	70	#ifdef MS_RELATIME
	71	{ MNTOPT_RELATIME, MS_RELATIME, ZS_COMMENT },
	72	#endif
	73	#ifdef MS_STRICTATIME
	74	{ MNTOPT_DFRATIME, MS_STRICTATIME, ZS_COMMENT },
	75	#endif
d53368f6 BB	76	{ MNTOPT_CONTEXT, MS_COMMENT, ZS_NOCONTEXT },
	77	{ MNTOPT_NOCONTEXT, MS_COMMENT, ZS_NOCONTEXT },
	78	{ MNTOPT_FSCONTEXT, MS_COMMENT, ZS_NOCONTEXT },
	79	{ MNTOPT_DEFCONTEXT, MS_COMMENT, ZS_NOCONTEXT },
	80	{ MNTOPT_ROOTCONTEXT, MS_COMMENT, ZS_NOCONTEXT },
d53368f6 BB	81	#ifdef MS_I_VERSION
	82	{ MNTOPT_IVERSION, MS_I_VERSION, ZS_COMMENT },
	83	#endif
	84	#ifdef MS_MANDLOCK
	85	{ MNTOPT_NBMAND, MS_MANDLOCK, ZS_COMMENT },
	86	#endif
	87	/* Valid options not found in mount(8) */
	88	{ MNTOPT_BIND, MS_BIND, ZS_COMMENT },
	89	#ifdef MS_REC
	90	{ MNTOPT_RBIND, MS_BIND\|MS_REC, ZS_COMMENT },
	91	#endif
	92	{ MNTOPT_COMMENT, MS_COMMENT, ZS_COMMENT },
	93	#ifdef MS_NOSUB
	94	{ MNTOPT_NOSUB, MS_NOSUB, ZS_COMMENT },
	95	#endif
	96	#ifdef MS_SILENT
	97	{ MNTOPT_QUIET, MS_SILENT, ZS_COMMENT },
	98	#endif
	99	/* Custom zfs options */
2cf7f52b	100	{ MNTOPT_XATTR, MS_COMMENT, ZS_COMMENT },
d53368f6 BB	101	{ MNTOPT_NOXATTR, MS_COMMENT, ZS_COMMENT },
	102	{ MNTOPT_ZFSUTIL, MS_COMMENT, ZS_ZFSUTIL },
	103	{ NULL, 0, 0 } };
	104
	105	/*
	106	* Break the mount option in to a name/value pair. The name is
	107	* validated against the option map and mount flags set accordingly.
	108	*/
	109	static int
	110	parse_option(char mntopt, unsigned long mntflags,
	111	unsigned long *zfsflags, int sloppy)
	112	{
	113	const option_map_t *opt;
	114	char ptr, name, *value = NULL;
	115	int error = 0;
	116
	117	name = strdup(mntopt);
	118	if (name == NULL)
	119	return (ENOMEM);
	120
	121	for (ptr = name; ptr && *ptr; ptr++) {
	122	if (*ptr == '=') {
	123	*ptr = '\0';
	124	value = ptr+1;
03514b01	125	VERIFY3P(value, !=, NULL);
d53368f6 BB	126	break;
	127	}
	128	}
	129
	130	for (opt = option_map; opt->name != NULL; opt++) {
	131	if (strncmp(name, opt->name, strlen(name)) == 0) {
	132	*mntflags \|= opt->mntmask;
	133	*zfsflags \|= opt->zfsmask;
	134
	135	/* MS_USERS implies default user options */
	136	if (opt->mntmask & (MS_USERS))
	137	*mntflags \|= (MS_NOEXEC\|MS_NOSUID\|MS_NODEV);
	138
	139	/* MS_OWNER\|MS_GROUP imply default owner options */
	140	if (opt->mntmask & (MS_OWNER \| MS_GROUP))
	141	*mntflags \|= (MS_NOSUID\|MS_NODEV);
	142
	143	error = 0;
	144	goto out;
	145	}
	146	}
	147
	148	if (!sloppy)
	149	error = ENOENT;
	150	out:
	151	/* If required further process on the value may be done here */
	152	free(name);
	153	return (error);
	154	}
	155
	156	/*
	157	* Translate the mount option string in to MS_* mount flags for the
	158	* kernel vfs. When sloppy is non-zero unknown options will be ignored
	159	* otherwise they are considered fatal are copied in to badopt.
	160	*/
	161	static int
3aff7755 BB	162	parse_options(char mntopts, unsigned long mntflags, unsigned long *zfsflags,
3aff7755 BB	163	int sloppy, char badopt, char mtabopt)
d53368f6	164	{
3aff7755	165	int error = 0, quote = 0, flag = 0, count = 0;
d53368f6 BB	166	char ptr, opt, *opts;
	167
	168	opts = strdup(mntopts);
	169	if (opts == NULL)
	170	return (ENOMEM);
	171
	172	*mntflags = 0;
	173	opt = NULL;
	174
	175	/*
	176	* Scan through all mount options which must be comma delimited.
	177	* We must be careful to notice regions which are double quoted
	178	* and skip commas in these regions. Each option is then checked
	179	* to determine if it is a known option.
	180	*/
	181	for (ptr = opts; ptr && !flag; ptr++) {
	182	if (opt == NULL)
	183	opt = ptr;
	184
	185	if (*ptr == '"')
	186	quote = !quote;
	187
	188	if (quote)
	189	continue;
	190
	191	if (*ptr == '\0')
	192	flag = 1;
	193
	194	if ((ptr == ',') \|\| (ptr == '\0')) {
	195	*ptr = '\0';
	196
	197	error = parse_option(opt, mntflags, zfsflags, sloppy);
	198	if (error) {
	199	strcpy(badopt, opt);
	200	goto out;
3aff7755 BB	201
	202	}
	203
	204	if (!(*mntflags & MS_REMOUNT) &&
	205	!(*zfsflags & ZS_ZFSUTIL)) {
	206	if (count > 0)
	207	strlcat(mtabopt, ",", MNT_LINE_MAX);
	208
	209	strlcat(mtabopt, opt, MNT_LINE_MAX);
	210	count++;
d53368f6 BB	211	}
	212
	213	opt = NULL;
	214	}
	215	}
	216
	217	out:
	218	free(opts);
	219	return (error);
	220	}
	221
	222	/*
	223	* If a file or directory in your current working directory is named
	224	* 'dataset' then mount(8) will prepend your current working directory
	225	* to dataset. The is no way to prevent this behavior so we simply
	226	* check for it and strip the prepended patch when it is added.
	227	*/
	228	static char *
	229	parse_dataset(char *dataset)
	230	{
	231	char cwd[PATH_MAX];
a6cba65c	232	int len;
d53368f6	233
ec49a5f0 BB	234	if (getcwd(cwd, PATH_MAX) == NULL)
	235	return (dataset);
	236
a6cba65c BB	237	len = strlen(cwd);
	238
	239	/* Do not add one when cwd already ends in a trailing '/' */
	240	if (!strncmp(cwd, dataset, len))
	241	return (dataset + len + (cwd[len-1] != '/'));
d53368f6 BB	242
	243	return (dataset);
	244	}
	245
	246	/*
	247	* Update the mtab_* code to use the libmount library when it is commonly
	248	* available otherwise fallback to legacy mode. The mount(8) utility will
	249	* manage the lock file for us to prevent racing updates to /etc/mtab.
	250	*/
	251	static int
	252	mtab_is_writeable(void)
	253	{
	254	struct stat st;
	255	int error, fd;
	256
e130330a	257	error = lstat(MNTTAB, &st);
d53368f6 BB	258	if (error \|\| S_ISLNK(st.st_mode))
	259	return (0);
	260
	261	fd = open(MNTTAB, O_RDWR \| O_CREAT, 0644);
	262	if (fd < 0)
	263	return (0);
	264
	265	close(fd);
	266	return (1);
	267	}
	268
	269	static int
	270	mtab_update(char dataset, char mntpoint, char type, char mntopts)
	271	{
	272	struct mntent mnt;
	273	FILE *fp;
	274	int error;
	275
	276	mnt.mnt_fsname = dataset;
	277	mnt.mnt_dir = mntpoint;
	278	mnt.mnt_type = type;
	279	mnt.mnt_opts = mntopts ? mntopts : "";
	280	mnt.mnt_freq = 0;
	281	mnt.mnt_passno = 0;
	282
	283	fp = setmntent(MNTTAB, "a+");
	284	if (!fp) {
	285	(void) fprintf(stderr, gettext(
	286	"filesystem '%s' was mounted, but %s "
	287	"could not be opened due to error %d\n"),
	288	dataset, MNTTAB, errno);
	289	return (MOUNT_FILEIO);
	290	}
	291
	292	error = addmntent(fp, &mnt);
	293	if (error) {
	294	(void) fprintf(stderr, gettext(
	295	"filesystem '%s' was mounted, but %s "
	296	"could not be updated due to error %d\n"),
	297	dataset, MNTTAB, errno);
	298	return (MOUNT_FILEIO);
	299	}
	300
	301	(void) endmntent(fp);
	302
	303	return (MOUNT_SUCCESS);
	304	}
	305
	306	int
	307	main(int argc, char **argv)
	308	{
	309	zfs_handle_t *zhp;
	310	char legacy[ZFS_MAXPROPLEN];
	311	char mntopts[MNT_LINE_MAX] = { '\0' };
	312	char badopt[MNT_LINE_MAX] = { '\0' };
3aff7755	313	char mtabopt[MNT_LINE_MAX] = { '\0' };
d53368f6	314	char dataset, mntpoint;
093aa692	315	unsigned long mntflags = 0, zfsflags = 0, remount_ro = 0;
d53368f6 BB	316	int sloppy = 0, fake = 0, verbose = 0, nomtab = 0, zfsutil = 0;
	317	int error, c;
	318
	319	(void) setlocale(LC_ALL, "");
	320	(void) textdomain(TEXT_DOMAIN);
	321
	322	opterr = 0;
	323
	324	/* check options */
	325	while ((c = getopt(argc, argv, "sfnvo:h?")) != -1) {
	326	switch (c) {
	327	case 's':
	328	sloppy = 1;
	329	break;
	330	case 'f':
	331	fake = 1;
	332	break;
	333	case 'n':
	334	nomtab = 1;
	335	break;
	336	case 'v':
	337	verbose++;
	338	break;
	339	case 'o':
	340	(void) strlcpy(mntopts, optarg, sizeof (mntopts));
	341	break;
	342	case 'h':
	343	case '?':
	344	(void) fprintf(stderr, gettext("Invalid option '%c'\n"),
	345	optopt);
	346	(void) fprintf(stderr, gettext("Usage: mount.zfs "
	347	"[-sfnv] [-o options] <dataset> <mountpoint>\n"));
	348	return (MOUNT_USAGE);
	349	}
	350	}
	351
	352	argc -= optind;
	353	argv += optind;
	354
	355	/* check that we only have two arguments */
	356	if (argc != 2) {
	357	if (argc == 0)
	358	(void) fprintf(stderr, gettext("missing dataset "
	359	"argument\n"));
	360	else if (argc == 1)
	361	(void) fprintf(stderr,
	362	gettext("missing mountpoint argument\n"));
	363	else
	364	(void) fprintf(stderr, gettext("too many arguments\n"));
	365	(void) fprintf(stderr, "usage: mount <dataset> <mountpoint>\n");
	366	return (MOUNT_USAGE);
	367	}
	368
	369	dataset = parse_dataset(argv[0]);
	370	mntpoint = argv[1];
	371
	372	/* validate mount options and set mntflags */
3aff7755 BB	373	error = parse_options(mntopts, &mntflags, &zfsflags, sloppy,
3aff7755 BB	374	badopt, mtabopt);
d53368f6 BB	375	if (error) {
	376	switch (error) {
	377	case ENOMEM:
	378	(void) fprintf(stderr, gettext("filesystem '%s' "
	379	"cannot be mounted due to a memory allocation "
3aff7755	380	"failure.\n"), dataset);
d53368f6	381	return (MOUNT_SYSERR);
3aff7755	382	case ENOENT:
d53368f6	383	(void) fprintf(stderr, gettext("filesystem '%s' "
3aff7755 BB	384	"cannot be mounted of due invalid option "
3aff7755 BB	385	"'%s'.\n"), dataset, badopt);
d53368f6 BB	386	(void) fprintf(stderr, gettext("Use the '-s' option "
	387	"to ignore the bad mount option.\n"));
	388	return (MOUNT_USAGE);
	389	default:
	390	(void) fprintf(stderr, gettext("filesystem '%s' "
3aff7755	391	"cannot be mounted due to internal error %d.\n"),
d53368f6 BB	392	dataset, error);
	393	return (MOUNT_SOFTWARE);
	394	}
	395	}
	396
	397	#ifdef HAVE_LIBSELINUX
	398	/*
	399	* Automatically add the default zfs context when selinux is enabled
	400	* and the caller has not specified their own context. This must be
	401	* done until zfs is added to the default selinux policy configuration
	402	* as a known filesystem type which supports xattrs.
	403	*/
3aff7755	404	if (is_selinux_enabled() && !(zfsflags & ZS_NOCONTEXT)) {
d53368f6 BB	405	(void) strlcat(mntopts, ",context=\"system_u:"
d53368f6 BB	406	"object_r:file_t:s0\"", sizeof (mntopts));
3aff7755 BB	407	(void) strlcat(mtabopt, ",context=\"system_u:"
	408	"object_r:file_t:s0\"", sizeof (mtabopt));
	409	}
d53368f6 BB	410	#endif /* HAVE_LIBSELINUX */
	411
	412
	413	if (verbose)
	414	(void) fprintf(stdout, gettext("mount.zfs:\n"
	415	" dataset: \"%s\"\n mountpoint: \"%s\"\n"
	416	" mountflags: 0x%lx\n zfsflags: 0x%lx\n"
3aff7755 BB	417	" mountopts: \"%s\"\n mtabopts: \"%s\"\n"),
3aff7755 BB	418	dataset, mntpoint, mntflags, zfsflags, mntopts, mtabopt);
d53368f6 BB	419
	420	if (mntflags & MS_REMOUNT)
	421	nomtab = 1;
	422
093aa692 BB	423	if ((mntflags & MS_REMOUNT) && (mntflags & MS_RDONLY))
	424	remount_ro = 1;
	425
	426	if (zfsflags & ZS_ZFSUTIL)
d53368f6 BB	427	zfsutil = 1;
	428
	429	if ((g_zfs = libzfs_init()) == NULL)
	430	return (MOUNT_SYSERR);
	431
	432	/* try to open the dataset to access the mount point */
3613204c BB	433	if ((zhp = zfs_open(g_zfs, dataset,
3613204c BB	434	ZFS_TYPE_FILESYSTEM \| ZFS_TYPE_SNAPSHOT)) == NULL) {
d53368f6 BB	435	(void) fprintf(stderr, gettext("filesystem '%s' cannot be "
	436	"mounted, unable to open the dataset\n"), dataset);
	437	libzfs_fini(g_zfs);
	438	return (MOUNT_USAGE);
	439	}
	440
3613204c BB	441	/* treat all snapshots as legacy mount points */
	442	if (zfs_get_type(zhp) == ZFS_TYPE_SNAPSHOT)
	443	(void) strlcpy(legacy, ZFS_MOUNTPOINT_LEGACY, ZFS_MAXPROPLEN);
	444	else
	445	(void) zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT, legacy,
	446	sizeof (legacy), NULL, NULL, 0, B_FALSE);
d53368f6 BB	447
	448	zfs_close(zhp);
	449	libzfs_fini(g_zfs);
	450
	451	/*
	452	* Legacy mount points may only be mounted using 'mount', never using
	453	* 'zfs mount'. However, since 'zfs mount' actually invokes 'mount'
	454	* we differentiate the two cases using the 'zfsutil' mount option.
	455	* This mount option should only be supplied by the 'zfs mount' util.
093aa692 BB	456	*
	457	* The only exception to the above rule is '-o remount,ro'. This is
	458	* always allowed for non-legacy datasets for rc.sysinit/umountroot
	459	* to safely remount the root filesystem and flush its cache.
d53368f6 BB	460	*/
	461	if (zfsutil && !strcmp(legacy, ZFS_MOUNTPOINT_LEGACY)) {
	462	(void) fprintf(stderr, gettext(
	463	"filesystem '%s' cannot be mounted using 'zfs mount'.\n"
	464	"Use 'zfs set mountpoint=%s' or 'mount -t zfs %s %s'.\n"
	465	"See zfs(8) for more information.\n"),
	466	dataset, mntpoint, dataset, mntpoint);
	467	return (MOUNT_USAGE);
	468	}
	469
093aa692	470	if (!zfsutil && strcmp(legacy, ZFS_MOUNTPOINT_LEGACY) && !remount_ro) {
d53368f6 BB	471	(void) fprintf(stderr, gettext(
	472	"filesystem '%s' cannot be mounted using 'mount'.\n"
	473	"Use 'zfs set mountpoint=%s' or 'zfs mount %s'.\n"
	474	"See zfs(8) for more information.\n"),
	475	dataset, "legacy", dataset);
	476	return (MOUNT_USAGE);
	477	}
	478
	479	if (!fake) {
	480	error = mount(dataset, mntpoint, MNTTYPE_ZFS,
	481	mntflags, mntopts);
	482	if (error) {
	483	switch (errno) {
847de122 RY	484	case ENOENT:
	485	(void) fprintf(stderr, gettext("mount point "
	486	"'%s' does not exist\n"), mntpoint);
	487	return (MOUNT_SYSERR);
d53368f6 BB	488	case EBUSY:
	489	(void) fprintf(stderr, gettext("filesystem "
	490	"'%s' is already mounted\n"), dataset);
	491	return (MOUNT_SYSERR);
	492	default:
	493	(void) fprintf(stderr, gettext("filesystem "
	494	"'%s' can not be mounted due to error "
	495	"%d\n"), dataset, errno);
	496	return (MOUNT_USAGE);
	497	}
	498	}
	499	}
	500
	501	if (!nomtab && mtab_is_writeable()) {
3aff7755	502	error = mtab_update(dataset, mntpoint, MNTTYPE_ZFS, mtabopt);
d53368f6 BB	503	if (error)
	504	return (error);
	505	}
	506
	507	return (MOUNT_SUCCESS);
	508	}