Add fstyp(8). This utility, named after its SVR4 counterpart, detects

filesystems.  It differs from file(1) in that it gives machine-parseable
output, it outputs filesystem labels, doesn't get confused by other
formats metadata, and runs in Capsicum sandbox.

Differential Revision:	https://reviews.freebsd.org/D1255
Relnotes:	yes
Sponsored by:	The FreeBSD Foundation

13 files changed, 1126 insertions, 2 deletions

diff --git a/contrib/file/doc/file.man b/contrib/file/doc/file.man
index 361188e13998..8e403bef897c 100644
--- a/contrib/file/doc/file.man
+++ b/contrib/file/doc/file.man
@@ -1,5 +1,5 @@
 .\" $File: file.man,v 1.106 2014/03/07 23:11:51 christos Exp $
-.Dd January 30, 2014
+.Dd December 3, 2014
 .Dt FILE __CSECTION__
 .Os
 .Sh NAME
@@ -385,6 +385,7 @@ options.
 .Xr hexdump 1 ,
 .Xr od 1 ,
 .Xr strings 1 ,
+.Xr fstyp 8
 .Sh STANDARDS CONFORMANCE
 This program is believed to exceed the System V Interface Definition
 of FILE(CMD), as near as one can determine from the vague language
diff --git a/sbin/mount/mount.8 b/sbin/mount/mount.8
index 12c25add90e6..aa7acfd61031 100644
--- a/sbin/mount/mount.8
+++ b/sbin/mount/mount.8
@@ -28,7 +28,7 @@
 .\"     @(#)mount.8	8.8 (Berkeley) 6/16/94
 .\" $FreeBSD$
 .\"
-.Dd November 22, 2014
+.Dd December 3, 2014
 .Dt MOUNT 8
 .Os
 .Sh NAME
@@ -549,6 +549,7 @@ support for a particular file system might be provided either on a static
 .Xr fstab 5 ,
 .Xr procfs 5 ,
 .Xr automount 8 ,
+.Xr fstyp 8 ,
 .Xr kldload 8 ,
 .Xr mount_cd9660 8 ,
 .Xr mount_msdosfs 8 ,
diff --git a/usr.sbin/Makefile b/usr.sbin/Makefile
index df9f8674793d..7c444816f42d 100644
--- a/usr.sbin/Makefile
+++ b/usr.sbin/Makefile
@@ -29,6 +29,7 @@ SUBDIR=	adduser \
 	extattr \
 	extattrctl \
 	fifolog \
+	fstyp \
 	fwcontrol \
 	getfmac \
 	getpmac \
diff --git a/usr.sbin/fstyp/Makefile b/usr.sbin/fstyp/Makefile
new file mode 100644
index 000000000000..d0b14d1bc795
--- /dev/null
+++ b/usr.sbin/fstyp/Makefile
@@ -0,0 +1,9 @@
+# $FreeBSD$
+
+PROG=	fstyp
+SRCS=	fstyp.c ext2fs.c cd9660.c msdosfs.c ntfs.c ufs.c
+MAN=	fstyp.8
+
+WARNS=	6
+
+.include <bsd.prog.mk>
diff --git a/usr.sbin/fstyp/cd9660.c b/usr.sbin/fstyp/cd9660.c
new file mode 100644
index 000000000000..26ea6942d6bb
--- /dev/null
+++ b/usr.sbin/fstyp/cd9660.c
@@ -0,0 +1,72 @@
+/*-
+ * Copyright (c) 2004 Pawel Jakub Dawidek <pjd@FreeBSD.org>
+ * Copyright (c) 2014 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Edward Tomasz Napierala under sponsorship
+ * from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "fstyp.h"
+
+#define G_LABEL_ISO9660_DIR	"iso9660"
+
+#define	ISO9660_MAGIC	"\x01" "CD001" "\x01\x00"
+#define	ISO9660_OFFSET	0x8000
+#define	VOLUME_LEN	32
+
+int
+fstyp_cd9660(FILE *fp, char *label, size_t size)
+{
+	char *sector, *volume;
+	int i;
+
+	sector = read_buf(fp, ISO9660_OFFSET, 512);
+	if (sector == NULL)
+		return (1);
+	if (bcmp(sector, ISO9660_MAGIC, sizeof(ISO9660_MAGIC) - 1) != 0) {
+		free(sector);
+		return (1);
+	}
+	volume = sector + 0x28;
+	bzero(label, size);
+	strlcpy(label, volume, MIN(size, VOLUME_LEN));
+	free(sector);
+	for (i = size - 1; i > 0; i--) {
+		if (label[i] == '\0')
+			continue;
+		else if (label[i] == ' ')
+			label[i] = '\0';
+		else
+			break;
+	}
+	return (0);
+}
diff --git a/usr.sbin/fstyp/ext2fs.c b/usr.sbin/fstyp/ext2fs.c
new file mode 100644
index 000000000000..df9e66e9155a
--- /dev/null
+++ b/usr.sbin/fstyp/ext2fs.c
@@ -0,0 +1,90 @@
+/*-
+ * Copyright (c) 2005 Stanislav Sedov
+ * Copyright (c) 2014 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Edward Tomasz Napierala under sponsorship
+ * from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "fstyp.h"
+
+#define EXT2FS_SB_OFFSET	1024
+#define EXT2_SUPER_MAGIC	0xef53
+#define EXT2_DYNAMIC_REV	1
+
+typedef struct e2sb {
+	uint8_t		fake1[56];
+	uint16_t	s_magic;
+	uint8_t		fake2[18];
+	uint32_t	s_rev_level;
+	uint8_t		fake3[40];
+	char		s_volume_name[16];
+} e2sb_t;
+
+int
+fstyp_ext2fs(FILE *fp, char *label, size_t size)
+{
+	e2sb_t *fs;
+	char *s_volume_name;
+
+	fs = (e2sb_t *)read_buf(fp, EXT2FS_SB_OFFSET, 512);
+	if (fs == NULL)
+		return (1);
+
+	/* Check for magic and versio n*/
+	if (fs->s_magic == EXT2_SUPER_MAGIC &&
+	    fs->s_rev_level == EXT2_DYNAMIC_REV) {
+		//G_LABEL_DEBUG(1, "ext2fs file system detected on %s.",
+		//    pp->name);
+	} else {
+		free(fs);
+		return (1);
+	}
+
+	s_volume_name = fs->s_volume_name;
+	/* Terminate label */
+	s_volume_name[sizeof(fs->s_volume_name) - 1] = '\0';
+
+	if (s_volume_name[0] == '/')
+		s_volume_name += 1;
+
+	/* Check for volume label */
+	if (s_volume_name[0] == '\0') {
+		free(fs);
+		return (1);
+	}
+
+	strlcpy(label, s_volume_name, size);
+
+	return (0);
+}
diff --git a/usr.sbin/fstyp/fstyp.8 b/usr.sbin/fstyp/fstyp.8
new file mode 100644
index 000000000000..a2594c5b7ca4
--- /dev/null
+++ b/usr.sbin/fstyp/fstyp.8
@@ -0,0 +1,97 @@
+.\" Copyright (c) 2014 The FreeBSD Foundation
+.\" All rights reserved.
+.\"
+.\" This software was developed by Edward Tomasz Napierala under sponsorship
+.\" from the FreeBSD Foundation.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd December 6, 2014
+.Dt FSTYP 8
+.Os
+.Sh NAME
+.Nm fstyp
+.Nd determine filesystem type
+.Sh SYNOPSIS
+.Nm
+.Op Fl l
+.Op Fl s
+.Ar special
+.Sh DESCRIPTION
+The
+.Nm
+utility is used to determine the filesystem type on a given device.
+It can recognize ISO-9660, Ext2, FAT, NTFS, and UFS filesystems.
+The filesystem name is printed to the standard output
+as, respectively,
+.Li cd9660 ,
+.Li ext2fs ,
+.Li msdosfs ,
+.Li ntfs ,
+or
+.Li ufs .
+.Pp
+Because
+.Nm
+is built specifically to detect filesystem types, it differs from
+.Xr file 1
+in several ways.
+The output is machine-parsable, filesystem labels are supported,
+and only filesystems are identified.
+Security is improved with
+.Xr capsicum 4 .
+.Pp
+These options are available:
+.Bl -tag -width ".Fl l"
+.It Fl l
+In addition to filesystem type, print filesystem label if available.
+.It Fl s
+Ignore file type.
+By default,
+.Nm
+only works on regular files and disk-like device nodes.
+Trying to read other file types might have unexpected consequences or hang
+indefinitely.
+.El
+.Sh EXIT STATUS
+The
+.Nm
+utility exits 0 on success, and >0 if an error occurs or the filesystem
+type is not recognized.
+.Sh SEE ALSO
+.Xr file 1 ,
+.Xr capsicum 4 ,
+.Xr glabel 8 ,
+.Xr mount 8
+.Sh HISTORY
+The
+.Nm
+command appeared in
+.Fx 11.0 .
+.Sh AUTHORS
+The
+.Nm
+utility was developed by
+.An Edward Tomasz Napierala Aq Mt trasz@FreeBSD.org
+under sponsorship from the FreeBSD Foundation.
diff --git a/usr.sbin/fstyp/fstyp.c b/usr.sbin/fstyp/fstyp.c
new file mode 100644
index 000000000000..d6a48f61d63a
--- /dev/null
+++ b/usr.sbin/fstyp/fstyp.c
@@ -0,0 +1,210 @@
+/*-
+ * Copyright (c) 2014 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Edward Tomasz Napierala under sponsorship
+ * from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/capsicum.h>
+#include <sys/disk.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <err.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <vis.h>
+
+#include "fstyp.h"
+
+#define	LABEL_LEN	256
+
+typedef int (*fstyp_function)(FILE *, char *, size_t);
+
+static struct {
+	const char	*name;
+	fstyp_function	function;
+} fstypes[] = {
+	{ "cd9660", &fstyp_cd9660 },
+	{ "ext2fs", &fstyp_ext2fs },
+	{ "msdosfs", &fstyp_msdosfs },
+	{ "ntfs", &fstyp_ntfs },
+	{ "ufs", &fstyp_ufs },
+	{ NULL, NULL }
+};
+
+void *
+read_buf(FILE *fp, off_t off, size_t len)
+{
+	int error;
+	size_t nread;
+	void *buf;
+
+	error = fseek(fp, off, SEEK_SET);
+	if (error != 0) {
+		warn("cannot seek to %jd", (uintmax_t)off);
+		return (NULL);
+	}
+
+	buf = malloc(len);
+	if (buf == 0) {
+		warn("cannot malloc %zd bytes of memory", len);
+		return (NULL);
+	}
+
+	nread = fread(buf, len, 1, fp);
+	if (nread != 1) {
+		free(buf);
+		if (feof(fp) == 0)
+			warn("fread");
+		return (NULL);
+	}
+
+	return (buf);
+}
+
+char *
+checked_strdup(const char *s)
+{
+	char *c;
+
+	c = strdup(s);
+	if (c == NULL)
+		err(1, "strdup");
+	return (c);
+}
+
+static void
+usage(void)
+{
+
+	fprintf(stderr, "usage: fstyp [-l][-s] special\n");
+	exit(1);
+}
+
+static void
+type_check(const char *path, FILE *fp)
+{
+	int error, fd;
+	off_t mediasize;
+	struct stat sb;
+
+	fd = fileno(fp);
+
+	error = fstat(fd, &sb);
+	if (error != 0)
+		err(1, "%s: fstat", path);
+
+	if (S_ISREG(sb.st_mode))
+		return;
+
+	error = ioctl(fd, DIOCGMEDIASIZE, &mediasize);
+	if (error != 0)
+		errx(1, "%s: not a disk", path);
+}
+
+int
+main(int argc, char **argv)
+{
+	int ch, error, i, nbytes;
+	bool ignore_type = false, show_label = false;
+	char label[LABEL_LEN + 1], strvised[LABEL_LEN * 4 + 1];
+	char *path;
+	FILE *fp;
+	fstyp_function fstyp_f;
+
+	while ((ch = getopt(argc, argv, "ls")) != -1) {
+		switch (ch) {
+		case 'l':
+			show_label = true;
+			break;
+		case 's':
+			ignore_type = true;
+			break;
+		default:
+			usage();
+		}
+	}
+
+	argc -= optind;
+	argv += optind;
+	if (argc != 1)
+		usage();
+
+	path = argv[0];
+
+	fp = fopen(path, "r");
+	if (fp == NULL)
+		err(1, "%s", path);
+
+	error = cap_enter();
+	if (error != 0 && errno != ENOSYS)
+		err(1, "cap_enter");
+
+	if (ignore_type == false)
+		type_check(path, fp);
+
+	memset(label, '\0', sizeof(label));
+
+	for (i = 0;; i++) {
+		fstyp_f = fstypes[i].function;
+		if (fstyp_f == NULL)
+			break;
+
+		error = fstyp_f(fp, label, sizeof(label));
+		if (error == 0)
+			break;
+	}
+
+	if (fstypes[i].name == NULL) {
+		warnx("%s: filesystem not recognized", path);
+		return (1);
+	}
+
+	if (show_label && label[0] != '\0') {
+		/*
+		 * XXX: I'd prefer VIS_HTTPSTYLE, but it unconditionally
+		 *      encodes spaces.
+		 */
+		nbytes = strsnvis(strvised, sizeof(strvised), label,
+		    VIS_GLOB | VIS_NL, "\"'$");
+		if (nbytes == -1)
+			err(1, "strsnvis");
+
+		printf("%s %s\n", fstypes[i].name, strvised);
+	} else {
+		printf("%s\n", fstypes[i].name);
+	}
+
+	return (0);
+}
diff --git a/usr.sbin/fstyp/fstyp.h b/usr.sbin/fstyp/fstyp.h
new file mode 100644
index 000000000000..4474ffe6f858
--- /dev/null
+++ b/usr.sbin/fstyp/fstyp.h
@@ -0,0 +1,46 @@
+/*-
+ * Copyright (c) 2014 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Edward Tomasz Napierala under sponsorship
+ * from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef FSTYP_H
+#define	FSTYP_H
+
+#define	MIN(a,b) (((a)<(b))?(a):(b))
+
+void	*read_buf(FILE *fp, off_t off, size_t len);
+char	*checked_strdup(const char *s);
+
+int	fstyp_cd9660(FILE *fp, char *label, size_t size);
+int	fstyp_ext2fs(FILE *fp, char *label, size_t size);
+int	fstyp_msdosfs(FILE *fp, char *label, size_t size);
+int	fstyp_ntfs(FILE *fp, char *label, size_t size);
+int	fstyp_ufs(FILE *fp, char *label, size_t size);
+
+#endif /* !FSTYP_H */
diff --git a/usr.sbin/fstyp/msdosfs.c b/usr.sbin/fstyp/msdosfs.c
new file mode 100644
index 000000000000..b299243aebd1
--- /dev/null
+++ b/usr.sbin/fstyp/msdosfs.c
@@ -0,0 +1,183 @@
+/*-
+ * Copyright (c) 2004 Pawel Jakub Dawidek <pjd@FreeBSD.org>
+ * Copyright (c) 2006 Tobias Reifenberger
+ * Copyright (c) 2014 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Edward Tomasz Napierala under sponsorship
+ * from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "fstyp.h"
+#include "msdosfs.h"
+
+#define LABEL_NO_NAME		"NO NAME    "
+
+int
+fstyp_msdosfs(FILE *fp, char *label, size_t size)
+{
+	FAT_BSBPB *pfat_bsbpb;
+	FAT32_BSBPB *pfat32_bsbpb;
+	FAT_DES *pfat_entry;
+	uint8_t *sector0, *sector;
+	uint32_t i;
+
+	sector0 = NULL;
+	sector = NULL;
+
+	/* Load 1st sector with boot sector and boot parameter block. */
+	sector0 = (uint8_t *)read_buf(fp, 0, 512);
+	if (sector0 == NULL)
+		return (1);
+
+	/* Check for the FAT boot sector signature. */
+	if (sector0[510] != 0x55 || sector0[511] != 0xaa) {
+		goto error;
+	}
+
+	/*
+	 * Test if this is really a FAT volume and determine the FAT type.
+	 */
+
+	pfat_bsbpb = (FAT_BSBPB *)sector0;
+	pfat32_bsbpb = (FAT32_BSBPB *)sector0;
+
+	if (UINT16BYTES(pfat_bsbpb->BPB_FATSz16) != 0) {
+		/*
+		 * If the BPB_FATSz16 field is not zero and the string "FAT" is
+		 * at the right place, this should be a FAT12 or FAT16 volume.
+		 */
+		if (strncmp(pfat_bsbpb->BS_FilSysType, "FAT", 3) != 0) {
+			goto error;
+		}
+
+		/* A volume with no name should have "NO NAME    " as label. */
+		if (strncmp(pfat_bsbpb->BS_VolLab, LABEL_NO_NAME,
+		    sizeof(pfat_bsbpb->BS_VolLab)) == 0) {
+			goto endofchecks;
+		}
+		strlcpy(label, pfat_bsbpb->BS_VolLab,
+		    MIN(size, sizeof(pfat_bsbpb->BS_VolLab) + 1));
+	} else if (UINT32BYTES(pfat32_bsbpb->BPB_FATSz32) != 0) {
+		uint32_t fat_FirstDataSector, fat_BytesPerSector, offset;
+
+		/*
+		 * If the BPB_FATSz32 field is not zero and the string "FAT" is
+		 * at the right place, this should be a FAT32 volume.
+		 */
+		if (strncmp(pfat32_bsbpb->BS_FilSysType, "FAT", 3) != 0) {
+			goto error;
+		}
+
+		/*
+		 * If the volume label is not "NO NAME    " we're done.
+		 */
+		if (strncmp(pfat32_bsbpb->BS_VolLab, LABEL_NO_NAME,
+		    sizeof(pfat32_bsbpb->BS_VolLab)) != 0) {
+			strlcpy(label, pfat32_bsbpb->BS_VolLab,
+			    MIN(size, sizeof(pfat32_bsbpb->BS_VolLab) + 1));
+			goto endofchecks;
+		}
+
+		/*
+		 * If the volume label "NO NAME    " is in the boot sector, the
+		 * label of FAT32 volumes may be stored as a special entry in
+		 * the root directory.
+		 */
+		fat_FirstDataSector =
+		    UINT16BYTES(pfat32_bsbpb->BPB_RsvdSecCnt) +
+		    (pfat32_bsbpb->BPB_NumFATs *
+		     UINT32BYTES(pfat32_bsbpb->BPB_FATSz32));
+		fat_BytesPerSector = UINT16BYTES(pfat32_bsbpb->BPB_BytsPerSec);
+
+		//    fat_FirstDataSector, fat_BytesPerSector);
+
+		for (offset = fat_BytesPerSector * fat_FirstDataSector;;
+		    offset += fat_BytesPerSector) {
+			sector = (uint8_t *)read_buf(fp, offset, fat_BytesPerSector);
+			if (sector == NULL)
+				goto error;
+
+			pfat_entry = (FAT_DES *)sector;
+			do {
+				/* No more entries available. */
+				if (pfat_entry->DIR_Name[0] == 0) {
+					goto endofchecks;
+				}
+
+				/* Skip empty or long name entries. */
+				if (pfat_entry->DIR_Name[0] == 0xe5 ||
+				    (pfat_entry->DIR_Attr &
+				     FAT_DES_ATTR_LONG_NAME) ==
+				    FAT_DES_ATTR_LONG_NAME) {
+					continue;
+				}
+
+				/*
+				 * The name of the entry is the volume label if
+				 * ATTR_VOLUME_ID is set.
+				 */
+				if (pfat_entry->DIR_Attr &
+				    FAT_DES_ATTR_VOLUME_ID) {
+					strlcpy(label, pfat_entry->DIR_Name,
+					    MIN(size,
+					    sizeof(pfat_entry->DIR_Name) + 1));
+					goto endofchecks;
+				}
+			} while((uint8_t *)(++pfat_entry) <
+			    (uint8_t *)(sector + fat_BytesPerSector));
+			free(sector);
+		}
+	} else {
+		goto error;
+	}
+
+endofchecks:
+	for (i = size - 1; i > 0; i--) {
+		if (label[i] == '\0')
+			continue;
+		else if (label[i] == ' ')
+			label[i] = '\0';
+		else
+			break;
+	}
+
+	free(sector0);
+	free(sector);
+
+	return (0);
+
+error:
+	free(sector0);
+	free(sector);
+
+	return (1);
+}
diff --git a/usr.sbin/fstyp/msdosfs.h b/usr.sbin/fstyp/msdosfs.h
new file mode 100644
index 000000000000..a04b87fe9706
--- /dev/null
+++ b/usr.sbin/fstyp/msdosfs.h
@@ -0,0 +1,140 @@
+/*-
+ * Copyright (c) 2006 Tobias Reifenberger
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include <sys/types.h>
+
+/*
+ * Conversion macros for little endian encoded unsigned integers
+ * in byte streams to the local unsigned integer format.
+ */
+#define UINT16BYTES(p) ((uint32_t)((p)[0] + (256*(p)[1])))
+#define UINT32BYTES(p) ((uint32_t)((p)[0] + (256*(p)[1]) +		\
+	    (65536*(p)[2]) + (16777216*(p)[3])))
+
+/*
+ * All following structures are according to:
+ *
+ * Microsoft Extensible Firmware Initiative FAT32 File System Specification
+ * FAT: General Overview of On-Disk Format
+ * Version 1.03, December 6, 2000
+ * Microsoft Corporation
+ */
+
+/*
+ * FAT boot sector and boot parameter block for
+ * FAT12 and FAT16 volumes
+ */
+typedef struct fat_bsbpb {
+	/* common fields */
+	uint8_t BS_jmpBoot[3];
+	uint8_t BS_OEMName[8];
+	uint8_t BPB_BytsPerSec[2];
+	uint8_t BPB_SecPerClus;
+	uint8_t BPB_RsvdSecCnt[2];
+	uint8_t BPB_NumFATs;
+	uint8_t BPB_RootEntCnt[2];
+	uint8_t BPB_TotSec16[2];
+	uint8_t BPB_Media;
+	uint8_t BPB_FATSz16[2];
+	uint8_t BPB_SecPerTrack[2];
+	uint8_t BPB_NumHeads[2];
+	uint8_t BPB_HiddSec[4];
+	uint8_t BPB_TotSec32[4];
+	/* FAT12/FAT16 only fields */
+	uint8_t BS_DrvNum;
+	uint8_t BS_Reserved1;
+	uint8_t BS_BootSig;
+	uint8_t BS_VolID[4];
+	uint8_t BS_VolLab[11];
+	uint8_t BS_FilSysType[8];
+} FAT_BSBPB; /* 62 bytes */
+
+/*
+ * FAT boot sector and boot parameter block for
+ * FAT32 volumes
+ */
+typedef struct fat32_bsbpb {
+	/* common fields */
+	uint8_t BS_jmpBoot[3];
+	uint8_t BS_OEMName[8];
+	uint8_t BPB_BytsPerSec[2];
+	uint8_t BPB_SecPerClus;
+	uint8_t BPB_RsvdSecCnt[2];
+	uint8_t BPB_NumFATs;
+	uint8_t BPB_RootEntCnt[2];
+	uint8_t BPB_TotSec16[2];
+	uint8_t BPB_Media;
+	uint8_t BPB_FATSz16[2];
+	uint8_t BPB_SecPerTrack[2];
+	uint8_t BPB_NumHeads[2];
+	uint8_t BPB_HiddSec[4];
+	uint8_t BPB_TotSec32[4];
+	/* FAT32 only fields */
+	uint8_t BPB_FATSz32[4];
+	uint8_t BPB_ExtFlags[2];
+	uint8_t BPB_FSVer[2];
+	uint8_t BPB_RootClus[4];
+	uint8_t BPB_FSInfo[2];
+	uint8_t BPB_BkBootSec[2];
+	uint8_t BPB_Reserved[12];
+	uint8_t BS_DrvNum;
+	uint8_t BS_Reserved1;
+	uint8_t BS_BootSig;
+	uint8_t BS_VolID[4];
+	uint8_t BS_VolLab[11];
+	uint8_t BS_FilSysType[8];
+} FAT32_BSBPB; /* 90 bytes */
+
+/*
+ * FAT directory entry structure
+ */
+#define	FAT_DES_ATTR_READ_ONLY	0x01
+#define	FAT_DES_ATTR_HIDDEN	0x02
+#define	FAT_DES_ATTR_SYSTEM	0x04
+#define	FAT_DES_ATTR_VOLUME_ID	0x08
+#define	FAT_DES_ATTR_DIRECTORY	0x10
+#define	FAT_DES_ATTR_ARCHIVE	0x20
+#define	FAT_DES_ATTR_LONG_NAME	(FAT_DES_ATTR_READ_ONLY |		\
+				 FAT_DES_ATTR_HIDDEN |			\
+				 FAT_DES_ATTR_SYSTEM |			\
+				 FAT_DES_ATTR_VOLUME_ID)
+
+typedef struct fat_des {
+	uint8_t DIR_Name[11];
+	uint8_t DIR_Attr;
+	uint8_t DIR_NTRes;
+	uint8_t DIR_CrtTimeTenth;
+	uint8_t DIR_CrtTime[2];
+	uint8_t DIR_CrtDate[2];
+	uint8_t DIR_LstAccDate[2];
+	uint8_t DIR_FstClusHI[2];
+	uint8_t DIR_WrtTime[2];
+	uint8_t DIR_WrtDate[2];
+	uint8_t DIR_FstClusLO[2];
+	uint8_t DIR_FileSize[4];
+} FAT_DES;
diff --git a/usr.sbin/fstyp/ntfs.c b/usr.sbin/fstyp/ntfs.c
new file mode 100644
index 000000000000..582f6b955e21
--- /dev/null
+++ b/usr.sbin/fstyp/ntfs.c
@@ -0,0 +1,165 @@
+/*-
+ * Copyright (c) 2005 Takanori Watanabe
+ * Copyright (c) 2014 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Edward Tomasz Napierala under sponsorship
+ * from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "fstyp.h"
+
+#define	NTFS_A_VOLUMENAME	0x60
+#define	NTFS_FILEMAGIC		((uint32_t)(0x454C4946))
+#define	NTFS_VOLUMEINO		3
+
+#define G_LABEL_NTFS_DIR	"ntfs"
+
+struct ntfs_attr {
+	uint32_t	a_type;
+	uint32_t	reclen;
+	uint8_t		a_flag;
+	uint8_t		a_namelen;
+	uint8_t		a_nameoff;
+	uint8_t		reserved1;
+	uint8_t		a_compression;
+	uint8_t		reserved2;
+	uint16_t	a_index;
+	uint16_t	a_datalen;
+	uint16_t	reserved3;
+	uint16_t	a_dataoff;
+	uint16_t	a_indexed;
+} __packed;
+
+struct ntfs_filerec {
+	uint32_t	fr_hdrmagic;
+	uint16_t	fr_hdrfoff;
+	uint16_t	fr_hdrfnum;
+	uint8_t		reserved[8];
+	uint16_t	fr_seqnum;
+	uint16_t	fr_nlink;
+	uint16_t	fr_attroff;
+	uint16_t	fr_flags;
+	uint32_t	fr_size;
+	uint32_t	fr_allocated;
+	uint64_t	fr_mainrec;
+	uint16_t	fr_attrnum;
+} __packed;
+
+struct ntfs_bootfile {
+	uint8_t		reserved1[3];
+	uint8_t		bf_sysid[8];
+	uint16_t	bf_bps;
+	uint8_t		bf_spc;
+	uint8_t		reserved2[7];
+	uint8_t		bf_media;
+	uint8_t		reserved3[2];
+	uint16_t	bf_spt;
+	uint16_t	bf_heads;
+	uint8_t		reserver4[12];
+	uint64_t	bf_spv;
+	uint64_t	bf_mftcn;
+	uint64_t	bf_mftmirrcn;
+	int8_t		bf_mftrecsz;
+	uint32_t	bf_ibsz;
+	uint32_t	bf_volsn;
+} __packed;
+
+int
+fstyp_ntfs(FILE *fp, char *label, size_t size)
+{
+	struct ntfs_bootfile *bf;
+	struct ntfs_filerec *fr;
+	struct ntfs_attr *atr;
+	off_t voloff;
+	char *filerecp, *ap;
+	int8_t mftrecsz;
+	char vnchar;
+	int recsize, j;
+
+	filerecp = NULL;
+
+	bf = (struct ntfs_bootfile *)read_buf(fp, 0, 512);
+	if (bf == NULL || strncmp(bf->bf_sysid, "NTFS    ", 8) != 0)
+		return (1);
+
+	mftrecsz = bf->bf_mftrecsz;
+	recsize = (mftrecsz > 0) ? (mftrecsz * bf->bf_bps * bf->bf_spc) : (1 << -mftrecsz);
+
+	voloff = bf->bf_mftcn * bf->bf_spc * bf->bf_bps +
+	    recsize * NTFS_VOLUMEINO;
+
+	filerecp = read_buf(fp, voloff, recsize);
+	if (filerecp == NULL)
+		goto fail;
+	fr = (struct ntfs_filerec *)filerecp;
+
+	if (fr->fr_hdrmagic != NTFS_FILEMAGIC)
+		goto fail;
+
+	for (ap = filerecp + fr->fr_attroff;
+	    atr = (struct ntfs_attr *)ap, (int)atr->a_type != -1;
+	    ap += atr->reclen) {
+		if (atr->a_type == NTFS_A_VOLUMENAME) {
+			if(atr->a_datalen >= size *2){
+				goto fail;
+			}
+			/*
+			 *UNICODE to ASCII.
+			 * Should we need to use iconv(9)?
+			 */
+			for (j = 0; j < atr->a_datalen; j++) {
+				vnchar = *(ap + atr->a_dataoff + j);
+				if (j & 1) {
+					if (vnchar) {
+						goto fail;
+					}
+				} else {
+					label[j / 2] = vnchar;
+				}
+			}
+			label[j / 2] = 0;
+			break;
+		}
+	}
+
+	free(bf);
+	free(filerecp);
+
+	return (0);
+
+fail:
+	free(bf);
+	free(filerecp);
+
+	return (1);
+}
diff --git a/usr.sbin/fstyp/ufs.c b/usr.sbin/fstyp/ufs.c
new file mode 100644
index 000000000000..8b27ca00fe43
--- /dev/null
+++ b/usr.sbin/fstyp/ufs.c
@@ -0,0 +1,109 @@
+/*-
+ * Copyright (c) 2002, 2003 Gordon Tetlow
+ * Copyright (c) 2006 Pawel Jakub Dawidek <pjd@FreeBSD.org>
+ * Copyright (c) 2014 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Edward Tomasz Napierala under sponsorship
+ * from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <ufs/ufs/dinode.h>
+#include <ufs/ffs/fs.h>
+
+#include "fstyp.h"
+
+static const int superblocks[] = SBLOCKSEARCH;
+
+int
+fstyp_ufs(FILE *fp, char *label, size_t labelsize)
+{
+	int sb, superblock;
+	struct fs *fs;
+
+	/*
+	 * Walk through the standard places that superblocks hide and look
+	 * for UFS magic. If we find magic, then check that the size in the
+	 * superblock corresponds to the size of the underlying provider.
+	 * Finally, look for a volume label and create an appropriate
+	 * provider based on that.
+	 */
+	for (sb = 0; (superblock = superblocks[sb]) != -1; sb++) {
+		fs = (struct fs *)read_buf(fp, superblock, SBLOCKSIZE);
+		if (fs == NULL)
+			continue;
+		/*
+		 * Check for magic. We also need to check if file system size is equal
+		 * to providers size, because sysinstall(8) used to bogusly put first
+		 * partition at offset 0 instead of 16, and glabel/ufs would find file
+		 * system on slice instead of partition.
+		 */
+#ifdef notyet
+		if (fs->fs_magic == FS_UFS1_MAGIC && fs->fs_fsize > 0 &&
+		    ((pp->mediasize / fs->fs_fsize == fs->fs_old_size) ||
+		    (pp->mediasize / fs->fs_fsize == fs->fs_providersize))) {
+		    	/* Valid UFS1. */
+		} else if (fs->fs_magic == FS_UFS2_MAGIC && fs->fs_fsize > 0 &&
+		    ((pp->mediasize / fs->fs_fsize == fs->fs_size) ||
+		    (pp->mediasize / fs->fs_fsize == fs->fs_providersize))) {
+		    	/* Valid UFS2. */
+		} else {
+			g_free(fs);
+			continue;
+		}
+#else
+		if (fs->fs_magic == FS_UFS1_MAGIC && fs->fs_fsize > 0) {
+		    	/* Valid UFS1. */
+		} else if (fs->fs_magic == FS_UFS2_MAGIC && fs->fs_fsize > 0) {
+		    	/* Valid UFS2. */
+		} else {
+			free(fs);
+			continue;
+		}
+#endif
+
+		if (fs->fs_sblockloc != superblock || fs->fs_ncg < 1 ||
+		    fs->fs_bsize < MINBSIZE ||
+		    (size_t)fs->fs_bsize < sizeof(struct fs)) {
+			free(fs);
+			continue;
+		}
+
+		strlcpy(label, fs->fs_volname, labelsize);
+
+		free(fs);
+		return (0);
+	}
+
+	return (1);
+}