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[src/trunk]: src/usr.sbin/fstyp fstyp: Show exFAT volume labels with -l flag
details: https://anonhg.NetBSD.org/src/rev/b99b31905569
branches: trunk
changeset: 466628:b99b31905569
user: tkusumi <tkusumi%NetBSD.org@localhost>
date: Sat Dec 28 08:00:08 2019 +0000
description:
fstyp: Show exFAT volume labels with -l flag
taken-from: FreeBSD (freebsd/freebsd@73773fcda9f69ce7ee0c73292f273bab940223bf)
diffstat:
usr.sbin/fstyp/exfat.c | 302 ++++++++++++++++++++++++++++++++++++++++++++++++-
usr.sbin/fstyp/fstyp.c | 50 ++++++--
usr.sbin/fstyp/fstyp.h | 9 +-
3 files changed, 343 insertions(+), 18 deletions(-)
diffs (truncated from 467 to 300 lines):
diff -r 0f3b821ce211 -r b99b31905569 usr.sbin/fstyp/exfat.c
--- a/usr.sbin/fstyp/exfat.c Sat Dec 28 04:23:26 2019 +0000
+++ b/usr.sbin/fstyp/exfat.c Sat Dec 28 08:00:08 2019 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: exfat.c,v 1.1 2019/11/18 14:53:34 tkusumi Exp $ */
+/* $NetBSD: exfat.c,v 1.2 2019/12/28 08:00:08 tkusumi Exp $ */
/*
* Copyright (c) 2017 Conrad Meyer <cem%FreeBSD.org@localhost>
@@ -26,8 +26,16 @@
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
-__RCSID("$NetBSD: exfat.c,v 1.1 2019/11/18 14:53:34 tkusumi Exp $");
+__RCSID("$NetBSD: exfat.c,v 1.2 2019/12/28 08:00:08 tkusumi Exp $");
+
+#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>
@@ -35,6 +43,10 @@
#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];
@@ -56,19 +68,301 @@
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 {
+ /*
+ * Count of "secondary" dirents following this one.
+ *
+ * A single logical entity may be composed of a
+ * sequence of several dirents, starting with a primary
+ * one; the rest are secondary dirents.
+ */
+ 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 fstyp.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, __UNCONST(&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 / (uint32_t)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;
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