Attachment #209496 for bug #242225




 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/endian.h>

#include <assert.h>
#include <err.h>
#include <errno.h>
#include <iconv.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "fstyp.h"

/*
 * https://docs.microsoft.com/en-us/windows/win32/fileio/exfat-specification
 */

struct exfat_vbr {
	char		ev_jmp[3];
	char		ev_fsname[8];
	char		ev_zeros[53];
	uint64_t	ev_part_offset;

	uint8_t		ev_num_fats;
	uint8_t		ev_drive_sel;
	uint8_t		ev_percent_used;
} __packed;

struct exfat_dirent {
	uint8_t		xde_type;
#define	XDE_TYPE_INUSE_MASK	0x80	/* 1=in use */
#define	XDE_TYPE_INUSE_SHIFT	7
#define	XDE_TYPE_CATEGORY_MASK	0x40	/* 0=primary */
#define	XDE_TYPE_CATEGORY_SHIFT	6
#define	XDE_TYPE_IMPORTNC_MASK	0x20	/* 0=critical */
#define	XDE_TYPE_IMPORTNC_SHIFT	5
#define	XDE_TYPE_CODE_MASK	0x1f
/* InUse=0, ..., TypeCode=0: EOD. */
#define	XDE_TYPE_EOD		0x00
#define	XDE_TYPE_ALLOC_BITMAP	(XDE_TYPE_INUSE_MASK | 0x01)
#define	XDE_TYPE_UPCASE_TABLE	(XDE_TYPE_INUSE_MASK | 0x02)
#define	XDE_TYPE_VOL_LABEL	(XDE_TYPE_INUSE_MASK | 0x03)
#define	XDE_TYPE_FILE		(XDE_TYPE_INUSE_MASK | 0x05)
#define	XDE_TYPE_VOL_GUID	(XDE_TYPE_INUSE_MASK | XDE_TYPE_IMPORTNC_MASK)
#define	XDE_TYPE_STREAM_EXT	(XDE_TYPE_INUSE_MASK | XDE_TYPE_CATEGORY_MASK)
#define	XDE_TYPE_FILE_NAME	(XDE_TYPE_INUSE_MASK | XDE_TYPE_CATEGORY_MASK | 0x01)
#define	XDE_TYPE_VENDOR		(XDE_TYPE_INUSE_MASK | XDE_TYPE_CATEGORY_MASK | XDE_TYPE_IMPORTNC_MASK)
#define	XDE_TYPE_VENDOR_ALLOC	(XDE_TYPE_INUSE_MASK | XDE_TYPE_CATEGORY_MASK | XDE_TYPE_IMPORTNC_MASK | 0x01)
	union {
		uint8_t	xde_generic_[19];
		struct exde_primary {
			// XXX: count of following dirents, "secondary"
			uint8_t		xde_secondary_count_;
			uint16_t	xde_set_chksum_;
			uint16_t	xde_prim_flags_;
			uint8_t		xde_prim_generic_[14];
		} __packed xde_primary_;
		struct exde_secondary {
			uint8_t		xde_sec_flags_;
			uint8_t		xde_sec_generic_[18];
		} __packed xde_secondary_;
	} u;
	uint32_t	xde_first_cluster;
	uint64_t	xde_data_len;
} __packed;
#define	xde_generic		u.xde_generic_
#define	xde_secondary_count	u.xde_primary_.xde_secondary_count
#define	xde_set_chksum		u.xde_primary_.xde_set_chksum_
#define	xde_prim_flags		u.xde_primary_.xde_prim_flags_
#define	xde_sec_flags		u.xde_secondary_.xde_sec_flags_
_Static_assert(sizeof(struct exfat_dirent) == 32, "spec");

struct exfat_de_label {
	uint8_t		xdel_type;	/* XDE_TYPE_VOL_LABEL */
	uint8_t		xdel_char_cnt;	/* Length of UCS-2 label */
	uint16_t	xdel_vol_lbl[11];
	uint8_t		xdel_reserved[8];
} __packed;
_Static_assert(sizeof(struct exfat_de_label) == 32, "spec");

#define	MAIN_BOOT_REGION_SECT	0
#define	BACKUP_BOOT_REGION_SECT	12

#define	SUBREGION_CHKSUM_SECT	11

#define	FIRST_CLUSTER		2
#define	BAD_BLOCK_SENTINEL	0xfffffff7u
#define	END_CLUSTER_SENTINEL	0xffffffffu

static inline void *
read_sectn(FILE *fp, off_t sect, unsigned count, unsigned bytespersec)
{
	return (read_buf(fp, sect * bytespersec, bytespersec * count));
}

static inline void *
read_sect(FILE *fp, off_t sect, unsigned bytespersec)
{
	return (read_sectn(fp, sect, 1, bytespersec));
}

/*
 * Compute the byte-by-byte multi-sector checksum of the given boot region
 * (MAIN or BACKUP), for a given bytespersec (typically 512 or 4096).
 *
 * Endian-safe; result is host endian.
 */
static int
exfat_compute_boot_chksum(FILE *fp, unsigned region, unsigned bytespersec,
    uint32_t *result)
{
	unsigned char *sector;
	unsigned n, sect;
	uint32_t checksum;

	checksum = 0;
	for (sect = 0; sect < 11; sect++) {
		sector = read_sect(fp, region + sect, bytespersec);
		if (sector == NULL)
			return (ENXIO);
		for (n = 0; n < bytespersec; n++) {
			if (sect == 0) {
				switch (n) {
				case 106:
				case 107:
				case 112:
					continue;
				}
			}
			checksum = ((checksum & 1) ? 0x80000000u : 0u) +
			    (checksum >> 1) + (uint32_t)sector[n];
		}
		free(sector);
	}

	*result = checksum;
	return (0);
}

static void
convert_label(const uint16_t *ucs2label /* LE */, unsigned ucs2len, char
    *label_out, size_t label_sz)
{
	const char *label;
	char *label_out_orig;
	iconv_t cd;
	size_t srcleft, rc;

	/* Currently hardcoded in fstype.c as 256 or so. */
	assert(label_sz > 1);

	if (ucs2len == 0) {
		/*
		 * Kind of seems bogus, but the spec allows an empty label
		 * entry with the same meaning as no label.
		 */
		return;
	}

	if (ucs2len > 11) {
		warnx("exfat: Bogus volume label length: %u", ucs2len);
		return;
	}

	/* dstname="" means convert to the current locale. */
	cd = iconv_open("", EXFAT_ENC);
	if (cd == (iconv_t)-1) {
		warn("exfat: Could not open iconv");
		return;
	}

	label_out_orig = label_out;

	/* Dummy up the byte pointer and byte length iconv's API wants. */
	label = (const void *)ucs2label;
	srcleft = ucs2len * sizeof(*ucs2label);

	rc = iconv(cd, __DECONST(char **, &label), &srcleft, &label_out,
	    &label_sz);
	if (rc == (size_t)-1) {
		warn("exfat: iconv()");
		*label_out_orig = '\0';
	} else {
		/* NUL-terminate result (iconv advances label_out). */
		if (label_sz == 0)
			label_out--;
		*label_out = '\0';
	}

	iconv_close(cd);
}

/*
 * Using the FAT table, look up the next cluster in this chain.
 */
static uint32_t
exfat_fat_next(FILE *fp, const struct exfat_vbr *ev, unsigned BPS,
    uint32_t cluster)
{
	uint32_t fat_offset_sect, clsect, clsectoff;
	uint32_t *fatsect, nextclust;

	fat_offset_sect = le32toh(ev->ev_fat_offset);
	clsect = fat_offset_sect + (cluster / (BPS / sizeof(cluster)));
	clsectoff = (cluster % (BPS / sizeof(cluster)));

	/* XXX This is pretty wasteful without a block cache for the FAT. */
	fatsect = read_sect(fp, clsect, BPS);
	nextclust = le32toh(fatsect[clsectoff]);
	free(fatsect);

	return (nextclust);
}

static void
exfat_find_label(FILE *fp, const struct exfat_vbr *ev, unsigned BPS,
    char *label_out, size_t label_sz)
{
	uint32_t rootdir_cluster, sects_per_clust, cluster_offset_sect;
	off_t rootdir_sect;
	struct exfat_dirent *declust, *it;

	cluster_offset_sect = le32toh(ev->ev_cluster_offset);
	rootdir_cluster = le32toh(ev->ev_rootdir_cluster);
	sects_per_clust = (1u << ev->ev_log_sect_per_clust);

	if (rootdir_cluster < FIRST_CLUSTER) {
		warnx("%s: invalid rootdir cluster %u < %d", __func__,
		    rootdir_cluster, FIRST_CLUSTER);
		return;
	}


	for (; rootdir_cluster != END_CLUSTER_SENTINEL;
	    rootdir_cluster = exfat_fat_next(fp, ev, BPS, rootdir_cluster)) {
		if (rootdir_cluster == BAD_BLOCK_SENTINEL) {
			warnx("%s: Bogus bad block in root directory chain",
			    __func__);
			return;
		}

		rootdir_sect = (rootdir_cluster - FIRST_CLUSTER) *
		    sects_per_clust + cluster_offset_sect;
		declust = read_sectn(fp, rootdir_sect, sects_per_clust, BPS);
		for (it = declust;
		    it < declust + (sects_per_clust * BPS / sizeof(*it)); it++) {
			bool eod = false;

			/*
			 * Simplistic directory traversal doesn't do any
			 * validation of MUST requirements in spec.
			 */
			switch (it->xde_type) {
			case XDE_TYPE_EOD:
				eod = true;
				break;
			case XDE_TYPE_VOL_LABEL: {
				struct exfat_de_label *lde = (void*)it;
				convert_label(lde->xdel_vol_lbl,
				    lde->xdel_char_cnt, label_out, label_sz);
				free(declust);
				return;
				}
			}

			if (eod)
				break;
		}
		free(declust);
	}
}

int
fstyp_exfat(FILE *fp, char *label, size_t size)
{
	struct exfat_vbr *ev;
	uint32_t *cksect;
	unsigned bytespersec;
	uint32_t chksum;
	int error;

	cksect = NULL;
	ev = (struct exfat_vbr *)read_buf(fp, 0, 512);
	if (ev == NULL || strncmp(ev->ev_fsname, "EXFAT   ", 8) != 0)
		goto fail;

	if (ev->ev_log_bytes_per_sect < 9 || ev->ev_log_bytes_per_sect > 12) {
		warnx("exfat: Invalid BytesPerSectorShift");
		goto done;
	}

	bytespersec = (1u << ev->ev_log_bytes_per_sect);

	error = exfat_compute_boot_chksum(fp, MAIN_BOOT_REGION_SECT,
	    bytespersec, &chksum);
	if (error != 0)
		goto done;

	cksect = read_sect(fp, MAIN_BOOT_REGION_SECT + SUBREGION_CHKSUM_SECT,
	    bytespersec);

	/*
	 * Technically the entire sector should be full of repeating 4-byte
	 * checksum pattern, but we only verify the first.
	 */
	if (chksum != le32toh(cksect[0])) {
		warnx("exfat: Found checksum 0x%08x != computed 0x%08x",
		    le32toh(cksect[0]), chksum);
		goto done;
	}

	exfat_find_label(fp, ev, bytespersec, label, size);

done:
	free(cksect);
	free(ev);
	return (0);

fail:
	free(ev);




#include <sys/ioctl.h>
#include <sys/stat.h>
#include <capsicum_helpers.h>
#include <err.h>
#include <errno.h>
#include <iconv.h>
#include <locale.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>


static struct {
	const char	*name;
	fstyp_function	function;
	bool		unmountable;
	char		*precache_encoding;
} fstypes[] = {
	{ "cd9660", &fstyp_cd9660, false, NULL },
	{ "exfat", &fstyp_exfat, false, EXFAT_ENC },
	{ "ext2fs", &fstyp_ext2fs, false, NULL },
	{ "geli", &fstyp_geli, true, NULL },
	{ "msdosfs", &fstyp_msdosfs, false, NULL },
	{ "ntfs", &fstyp_ntfs, false, NULL },
	{ "ufs", &fstyp_ufs, false, NULL },
#ifdef HAVE_ZFS
	{ "zfs", &fstyp_zfs, true, NULL },
#endif
	{ NULL, NULL, NULL, NULL }
};

void *
read_buf(FILE *fp, off_t off, size_t len)
{

	if (argc != 1)
		usage();

	path = argv[0];

	if (setlocale(LC_CTYPE, "") == NULL)
		err(1, "setlocale");
	caph_cache_catpages();

	/* Cache iconv conversion data before entering capability mode. */
	if (show_label) {
		for (i = 0; i < nitems(fstypes); i++) {
			iconv_t cd;

			if (fstypes[i].precache_encoding == NULL)
				continue;
			cd = iconv_open("", fstypes[i].precache_encoding);
			if (cd == (iconv_t)-1)
				err(1, "%s: iconv_open %s", fstypes[i].name,
				    fstypes[i].precache_encoding);
			/* Iconv keeps a small cache of unused encodings. */
			iconv_close(cd);
		}
	}

	fp = fopen(path, "r");
	if (fp == NULL)
		err(1, "%s", path);

	if (caph_enter() < 0)

Lines 31-40 Link Here

(-)b/usr.sbin/fstyp/fstyp.h (+2 lines)
31		31
32	#ifndef FSTYP_H	32	#ifndef FSTYP_H
33	#define FSTYP_H	33	#define FSTYP_H
34		34
35	#define MIN(a,b) (((a)<(b))?(a):(b))	35	#define MIN(a,b) (((a)<(b))?(a):(b))
		36	/* The spec doesn't seem to permit UTF-16 surrogates. Definitely LE. */
		37	#define EXFAT_ENC "UCS-2LE"
36		38
37	void read_buf(FILE fp, off_t off, size_t len);	39	void read_buf(FILE fp, off_t off, size_t len);
38	char checked_strdup(const char s);	40	char checked_strdup(const char s);
39	void rtrim(char *label, size_t size);	41	void rtrim(char *label, size_t size);
40		42




exfat_body() {
	bzcat $(atf_get_srcdir)/dfr-01-xfat.img.bz2 > exfat.img
	atf_check -s exit:0 -o inline:"exfat\n" fstyp -u exfat.img
}

atf_test_case exfat_label
exfat_label_head() {
	atf_set "descr" "fstyp(8) can read exFAT labels"
}
exfat_label_body() {
	bzcat $(atf_get_srcdir)/dfr-01-xfat.img.bz2 > exfat.img
	atf_check -s exit:0 -o inline:"exfat exFat\n" fstyp -u -l exfat.img
}

atf_test_case empty
empty_head() {
	atf_set "descr" "fstyp(8) should fail on an empty file"
}
empty_body() {

	atf_add_test_case cd9660
	atf_add_test_case cd9660_label
	atf_add_test_case dir
	atf_add_test_case empty
	atf_add_test_case exfat
	atf_add_test_case exfat_label
	atf_add_test_case ext2
	atf_add_test_case ext3
	atf_add_test_case ext4
	atf_add_test_case ext4_label
	atf_add_test_case fat12
- 

Return to bug 242225

Lines 66-75 exfat_head() { Link Here

(-)b/usr.sbin/fstyp/tests/fstyp_test.sh (-1 / +10 lines)
66	exfat_body() {	66	exfat_body() {
67	bzcat $(atf_get_srcdir)/dfr-01-xfat.img.bz2 > exfat.img	67	bzcat $(atf_get_srcdir)/dfr-01-xfat.img.bz2 > exfat.img
68	atf_check -s exit:0 -o inline:"exfat\n" fstyp -u exfat.img	68	atf_check -s exit:0 -o inline:"exfat\n" fstyp -u exfat.img
69	}	69	}
70		70
		71	atf_test_case exfat_label
		72	exfat_label_head() {
		73	atf_set "descr" "fstyp(8) can read exFAT labels"
		74	}
		75	exfat_label_body() {
		76	bzcat $(atf_get_srcdir)/dfr-01-xfat.img.bz2 > exfat.img
		77	atf_check -s exit:0 -o inline:"exfat exFat\n" fstyp -u -l exfat.img
		78	}
		79
71	atf_test_case empty	80	atf_test_case empty
72	empty_head() {	81	empty_head() {
73	atf_set "descr" "fstyp(8) should fail on an empty file"	82	atf_set "descr" "fstyp(8) should fail on an empty file"
74	}	83	}
75	empty_body() {	84	empty_body() {
Lines 251-260 atf_init_test_cases() { Link Here
251	atf_add_test_case cd9660	260	atf_add_test_case cd9660
252	atf_add_test_case cd9660_label	261	atf_add_test_case cd9660_label
253	atf_add_test_case dir	262	atf_add_test_case dir
254	atf_add_test_case empty	263	atf_add_test_case empty
255	atf_add_test_case exfat	264	atf_add_test_case exfat
		265	atf_add_test_case exfat_label
256	atf_add_test_case ext2	266	atf_add_test_case ext2
257	atf_add_test_case ext3	267	atf_add_test_case ext3
258	atf_add_test_case ext4	268	atf_add_test_case ext4
259	atf_add_test_case ext4_label	269	atf_add_test_case ext4_label
260	atf_add_test_case fat12	270	atf_add_test_case fat12
261	-

Lines 25-41 Link Here

(-)b/usr.sbin/fstyp/exfat.c (-2 / +288 lines)
25	*/	25	*/
26		26
27	#include <sys/cdefs.h>	27	#include <sys/cdefs.h>
28	__FBSDID("$FreeBSD$");	28	__FBSDID("$FreeBSD$");
29		29
		30	#include <sys/param.h>
		31	#include <sys/endian.h>
		32
		33	#include <assert.h>
		34	#include <err.h>
		35	#include <errno.h>
		36	#include <iconv.h>
		37	#include <stdbool.h>
30	#include <stdint.h>	38	#include <stdint.h>
31	#include <stdio.h>	39	#include <stdio.h>
32	#include <stdlib.h>	40	#include <stdlib.h>
33	#include <string.h>	41	#include <string.h>
34		42
35	#include "fstyp.h"	43	#include "fstyp.h"
36		44
		45	/*
		46	* https://docs.microsoft.com/en-us/windows/win32/fileio/exfat-specification
		47	*/
		48
37	struct exfat_vbr {	49	struct exfat_vbr {
38	char ev_jmp[3];	50	char ev_jmp[3];
39	char ev_fsname[8];	51	char ev_fsname[8];
40	char ev_zeros[53];	52	char ev_zeros[53];
41	uint64_t ev_part_offset;	53	uint64_t ev_part_offset;
Lines 53-75 struct exfat_vbr { Link Here
53	uint8_t ev_num_fats;	65	uint8_t ev_num_fats;
54	uint8_t ev_drive_sel;	66	uint8_t ev_drive_sel;
55	uint8_t ev_percent_used;	67	uint8_t ev_percent_used;
56	} __packed;	68	} __packed;
57		69
		70	struct exfat_dirent {
		71	uint8_t xde_type;
		72	#define XDE_TYPE_INUSE_MASK 0x80 /* 1=in use */
		73	#define XDE_TYPE_INUSE_SHIFT 7
		74	#define XDE_TYPE_CATEGORY_MASK 0x40 /* 0=primary */
		75	#define XDE_TYPE_CATEGORY_SHIFT 6
		76	#define XDE_TYPE_IMPORTNC_MASK 0x20 /* 0=critical */
		77	#define XDE_TYPE_IMPORTNC_SHIFT 5
		78	#define XDE_TYPE_CODE_MASK 0x1f
		79	/* InUse=0, ..., TypeCode=0: EOD. */
		80	#define XDE_TYPE_EOD 0x00
		81	#define XDE_TYPE_ALLOC_BITMAP (XDE_TYPE_INUSE_MASK \| 0x01)
		82	#define XDE_TYPE_UPCASE_TABLE (XDE_TYPE_INUSE_MASK \| 0x02)
		83	#define XDE_TYPE_VOL_LABEL (XDE_TYPE_INUSE_MASK \| 0x03)
		84	#define XDE_TYPE_FILE (XDE_TYPE_INUSE_MASK \| 0x05)
		85	#define XDE_TYPE_VOL_GUID (XDE_TYPE_INUSE_MASK \| XDE_TYPE_IMPORTNC_MASK)
		86	#define XDE_TYPE_STREAM_EXT (XDE_TYPE_INUSE_MASK \| XDE_TYPE_CATEGORY_MASK)
		87	#define XDE_TYPE_FILE_NAME (XDE_TYPE_INUSE_MASK \| XDE_TYPE_CATEGORY_MASK \| 0x01)
		88	#define XDE_TYPE_VENDOR (XDE_TYPE_INUSE_MASK \| XDE_TYPE_CATEGORY_MASK \| XDE_TYPE_IMPORTNC_MASK)
		89	#define XDE_TYPE_VENDOR_ALLOC (XDE_TYPE_INUSE_MASK \| XDE_TYPE_CATEGORY_MASK \| XDE_TYPE_IMPORTNC_MASK \| 0x01)
		90	union {
		91	uint8_t xde_generic_[19];
		92	struct exde_primary {
		93	// XXX: count of following dirents, "secondary"
		94	uint8_t xde_secondary_count_;
		95	uint16_t xde_set_chksum_;
		96	uint16_t xde_prim_flags_;
		97	uint8_t xde_prim_generic_[14];
		98	} __packed xde_primary_;
		99	struct exde_secondary {
		100	uint8_t xde_sec_flags_;
		101	uint8_t xde_sec_generic_[18];
		102	} __packed xde_secondary_;
		103	} u;
		104	uint32_t xde_first_cluster;
		105	uint64_t xde_data_len;
		106	} __packed;
		107	#define xde_generic u.xde_generic_
		108	#define xde_secondary_count u.xde_primary_.xde_secondary_count
		109	#define xde_set_chksum u.xde_primary_.xde_set_chksum_
		110	#define xde_prim_flags u.xde_primary_.xde_prim_flags_
		111	#define xde_sec_flags u.xde_secondary_.xde_sec_flags_
		112	_Static_assert(sizeof(struct exfat_dirent) == 32, "spec");
		113
		114	struct exfat_de_label {
		115	uint8_t xdel_type; /* XDE_TYPE_VOL_LABEL */
		116	uint8_t xdel_char_cnt; /* Length of UCS-2 label */
		117	uint16_t xdel_vol_lbl[11];
		118	uint8_t xdel_reserved[8];
		119	} __packed;
		120	_Static_assert(sizeof(struct exfat_de_label) == 32, "spec");
		121
		122	#define MAIN_BOOT_REGION_SECT 0
		123	#define BACKUP_BOOT_REGION_SECT 12
		124
		125	#define SUBREGION_CHKSUM_SECT 11
		126
		127	#define FIRST_CLUSTER 2
		128	#define BAD_BLOCK_SENTINEL 0xfffffff7u
		129	#define END_CLUSTER_SENTINEL 0xffffffffu
		130
		131	static inline void *
		132	read_sectn(FILE *fp, off_t sect, unsigned count, unsigned bytespersec)
		133	{
134	return (read_buf(fp, sect * bytespersec, bytespersec * count));
135	}
136
137	static inline void *
138	read_sect(FILE *fp, off_t sect, unsigned bytespersec)
139	{
140	return (read_sectn(fp, sect, 1, bytespersec));
141	}
142
143	/*
144	* Compute the byte-by-byte multi-sector checksum of the given boot region
145	* (MAIN or BACKUP), for a given bytespersec (typically 512 or 4096).
146	*
147	* Endian-safe; result is host endian.
148	*/
149	static int
150	exfat_compute_boot_chksum(FILE *fp, unsigned region, unsigned bytespersec,
151	uint32_t *result)
152	{
153	unsigned char *sector;
154	unsigned n, sect;
155	uint32_t checksum;
156
157	checksum = 0;
158	for (sect = 0; sect < 11; sect++) {
159	sector = read_sect(fp, region + sect, bytespersec);
160	if (sector == NULL)
161	return (ENXIO);
162	for (n = 0; n < bytespersec; n++) {
163	if (sect == 0) {
164	switch (n) {
165	case 106:
166	case 107:
167	case 112:
168	continue;
169	}
170	}
171	checksum = ((checksum & 1) ? 0x80000000u : 0u) +
172	(checksum >> 1) + (uint32_t)sector[n];
173	}
174	free(sector);
175	}
176
177	*result = checksum;
178	return (0);
179	}
180
181	static void
182	convert_label(const uint16_t ucs2label / LE */, unsigned ucs2len, char
183	*label_out, size_t label_sz)
184	{
185	const char *label;
186	char *label_out_orig;
187	iconv_t cd;
188	size_t srcleft, rc;
189
190	/* Currently hardcoded in fstype.c as 256 or so. */
191	assert(label_sz > 1);
192
193	if (ucs2len == 0) {
194	/*
195	* Kind of seems bogus, but the spec allows an empty label
196	* entry with the same meaning as no label.
197	*/
198	return;
199	}
200
201	if (ucs2len > 11) {
202	warnx("exfat: Bogus volume label length: %u", ucs2len);
203	return;
204	}
205
206	/* dstname="" means convert to the current locale. */
207	cd = iconv_open("", EXFAT_ENC);
208	if (cd == (iconv_t)-1) {
209	warn("exfat: Could not open iconv");
210	return;
211	}
212
213	label_out_orig = label_out;
214
215	/* Dummy up the byte pointer and byte length iconv's API wants. */
216	label = (const void *)ucs2label;
217	srcleft = ucs2len * sizeof(*ucs2label);
218
219	rc = iconv(cd, __DECONST(char **, &label), &srcleft, &label_out,
220	&label_sz);
221	if (rc == (size_t)-1) {
222	warn("exfat: iconv()");
223	*label_out_orig = '\0';
224	} else {
225	/* NUL-terminate result (iconv advances label_out). */
226	if (label_sz == 0)
227	label_out--;
228	*label_out = '\0';
229	}
230
231	iconv_close(cd);
232	}
233
234	/*
235	* Using the FAT table, look up the next cluster in this chain.
236	*/
237	static uint32_t
238	exfat_fat_next(FILE fp, const struct exfat_vbr ev, unsigned BPS,
239	uint32_t cluster)
240	{
241	uint32_t fat_offset_sect, clsect, clsectoff;
242	uint32_t *fatsect, nextclust;
243
244	fat_offset_sect = le32toh(ev->ev_fat_offset);
245	clsect = fat_offset_sect + (cluster / (BPS / sizeof(cluster)));
246	clsectoff = (cluster % (BPS / sizeof(cluster)));
247
248	/* XXX This is pretty wasteful without a block cache for the FAT. */
249	fatsect = read_sect(fp, clsect, BPS);
250	nextclust = le32toh(fatsect[clsectoff]);
251	free(fatsect);
252
253	return (nextclust);
254	}
255
256	static void
257	exfat_find_label(FILE fp, const struct exfat_vbr ev, unsigned BPS,
258	char *label_out, size_t label_sz)
259	{
260	uint32_t rootdir_cluster, sects_per_clust, cluster_offset_sect;
261	off_t rootdir_sect;
262	struct exfat_dirent declust, it;
263
264	cluster_offset_sect = le32toh(ev->ev_cluster_offset);
265	rootdir_cluster = le32toh(ev->ev_rootdir_cluster);
266	sects_per_clust = (1u << ev->ev_log_sect_per_clust);
267
268	if (rootdir_cluster < FIRST_CLUSTER) {
269	warnx("%s: invalid rootdir cluster %u < %d", __func__,
270	rootdir_cluster, FIRST_CLUSTER);
271	return;
272	}
273
274
275	for (; rootdir_cluster != END_CLUSTER_SENTINEL;
276	rootdir_cluster = exfat_fat_next(fp, ev, BPS, rootdir_cluster)) {
277	if (rootdir_cluster == BAD_BLOCK_SENTINEL) {
278	warnx("%s: Bogus bad block in root directory chain",
279	__func__);
280	return;
281	}
282
283	rootdir_sect = (rootdir_cluster - FIRST_CLUSTER) *
284	sects_per_clust + cluster_offset_sect;
285	declust = read_sectn(fp, rootdir_sect, sects_per_clust, BPS);
286	for (it = declust;
287	it < declust + (sects_per_clust * BPS / sizeof(*it)); it++) {
288	bool eod = false;
289
290	/*
291	* Simplistic directory traversal doesn't do any
292	* validation of MUST requirements in spec.
293	*/
294	switch (it->xde_type) {
295	case XDE_TYPE_EOD:
296	eod = true;
297	break;
298	case XDE_TYPE_VOL_LABEL: {
299	struct exfat_de_label lde = (void)it;
300	convert_label(lde->xdel_vol_lbl,
301	lde->xdel_char_cnt, label_out, label_sz);
302	free(declust);
303	return;
304	}
305	}
306
307	if (eod)
308	break;
309	}
310	free(declust);
311	}
312	}
313
58	int	314	int
59	fstyp_exfat(FILE fp, char label, size_t size)	315	fstyp_exfat(FILE fp, char label, size_t size)
60	{	316	{
61	struct exfat_vbr *ev;	317	struct exfat_vbr *ev;
		318	uint32_t *cksect;
		319	unsigned bytespersec;
		320	uint32_t chksum;
		321	int error;
62		322
		323	cksect = NULL;
63	ev = (struct exfat_vbr *)read_buf(fp, 0, 512);	324	ev = (struct exfat_vbr *)read_buf(fp, 0, 512);
64	if (ev == NULL \|\| strncmp(ev->ev_fsname, "EXFAT ", 8) != 0)	325	if (ev == NULL \|\| strncmp(ev->ev_fsname, "EXFAT ", 8) != 0)
65	goto fail;	326	goto fail;
66		327
		328	if (ev->ev_log_bytes_per_sect < 9 \|\| ev->ev_log_bytes_per_sect > 12) {
		329	warnx("exfat: Invalid BytesPerSectorShift");
		330	goto done;
		331	}
		332
		333	bytespersec = (1u << ev->ev_log_bytes_per_sect);
		334
		335	error = exfat_compute_boot_chksum(fp, MAIN_BOOT_REGION_SECT,
		336	bytespersec, &chksum);
		337	if (error != 0)
		338	goto done;
		339
		340	cksect = read_sect(fp, MAIN_BOOT_REGION_SECT + SUBREGION_CHKSUM_SECT,
		341	bytespersec);
		342
67	/*	343	/*
68	* Reading the volume label requires walking the root directory to look	344	* Technically the entire sector should be full of repeating 4-byte
69	* for a special label file. Left as an exercise for the reader.	345	* checksum pattern, but we only verify the first.
70	*/	346	*/
		347	if (chksum != le32toh(cksect[0])) {
		348	warnx("exfat: Found checksum 0x%08x != computed 0x%08x",
		349	le32toh(cksect[0]), chksum);
		350	goto done;
		351	}
		352
		353	exfat_find_label(fp, ev, bytespersec, label, size);
		354
		355	done:
		356	free(cksect);
71	free(ev);	357	free(ev);
72	return (0);	358	return (0);
73		359
74	fail:	360	fail:
75	free(ev);	361	free(ev);

Lines 36-45 __FBSDID("$FreeBSD$"); Link Here

(-)b/usr.sbin/fstyp/fstyp.c (-9 / +32 lines)
36	#include <sys/ioctl.h>	36	#include <sys/ioctl.h>
37	#include <sys/stat.h>	37	#include <sys/stat.h>
38	#include <capsicum_helpers.h>	38	#include <capsicum_helpers.h>
39	#include <err.h>	39	#include <err.h>
40	#include <errno.h>	40	#include <errno.h>
		41	#include <iconv.h>
		42	#include <locale.h>
41	#include <stdbool.h>	43	#include <stdbool.h>
42	#include <stddef.h>	44	#include <stddef.h>
43	#include <stdio.h>	45	#include <stdio.h>
44	#include <stdlib.h>	46	#include <stdlib.h>
45	#include <string.h>	47	#include <string.h>
Lines 54-75 typedef int (fstyp_function)(FILE , char *, size_t); Link Here
54		56
55	static struct {	57	static struct {
56	const char *name;	58	const char *name;
57	fstyp_function function;	59	fstyp_function function;
58	bool unmountable;	60	bool unmountable;
		61	char *precache_encoding;
59	} fstypes[] = {	62	} fstypes[] = {
60	{ "cd9660", &fstyp_cd9660, false },	63	{ "cd9660", &fstyp_cd9660, false, NULL },
61	{ "exfat", &fstyp_exfat, false },	64	{ "exfat", &fstyp_exfat, false, EXFAT_ENC },
62	{ "ext2fs", &fstyp_ext2fs, false },	65	{ "ext2fs", &fstyp_ext2fs, false, NULL },
63	{ "geli", &fstyp_geli, true },	66	{ "geli", &fstyp_geli, true, NULL },
64	{ "msdosfs", &fstyp_msdosfs, false },	67	{ "msdosfs", &fstyp_msdosfs, false, NULL },
65	{ "ntfs", &fstyp_ntfs, false },	68	{ "ntfs", &fstyp_ntfs, false, NULL },
66	{ "ufs", &fstyp_ufs, false },	69	{ "ufs", &fstyp_ufs, false, NULL },
67	#ifdef HAVE_ZFS	70	#ifdef HAVE_ZFS
68	{ "zfs", &fstyp_zfs, true },	71	{ "zfs", &fstyp_zfs, true, NULL },
69	#endif	72	#endif
70	{ NULL, NULL, NULL }	73	{ NULL, NULL, NULL, NULL }
71	};	74	};
72		75
73	void *	76	void *
74	read_buf(FILE *fp, off_t off, size_t len)	77	read_buf(FILE *fp, off_t off, size_t len)
75	{	78	{
Lines 186-195 main(int argc, char **argv) Link Here
186	if (argc != 1)	189	if (argc != 1)
187	usage();	190	usage();
188		191
189	path = argv[0];	192	path = argv[0];
190		193
		194	if (setlocale(LC_CTYPE, "") == NULL)
		195	err(1, "setlocale");
		196	caph_cache_catpages();
		197
		198	/* Cache iconv conversion data before entering capability mode. */
		199	if (show_label) {
		200	for (i = 0; i < nitems(fstypes); i++) {
		201	iconv_t cd;
		202
		203	if (fstypes[i].precache_encoding == NULL)
		204	continue;
		205	cd = iconv_open("", fstypes[i].precache_encoding);
		206	if (cd == (iconv_t)-1)
		207	err(1, "%s: iconv_open %s", fstypes[i].name,
		208	fstypes[i].precache_encoding);
		209	/* Iconv keeps a small cache of unused encodings. */
		210	iconv_close(cd);
		211	}
		212	}
		213
191	fp = fopen(path, "r");	214	fp = fopen(path, "r");
192	if (fp == NULL)	215	if (fp == NULL)
193	err(1, "%s", path);	216	err(1, "%s", path);
194		217
195	if (caph_enter() < 0)	218	if (caph_enter() < 0)