Sun Jan 24 14:37:32 2021 UTC ()

fstyp: Fix exfat detection

taken-from FreeBSD ddf61156132b610915325769cbb93ea11be0d433


(tkusumi)

diff -r1.3 -r1.4 src/usr.sbin/fstyp/exfat.c

--- src/usr.sbin/fstyp/exfat.c 2020/02/08 12:56:56	1.3
+++ src/usr.sbin/fstyp/exfat.c 2021/01/24 14:37:32	1.4

 @@ -1,14 +1,14 @@
-/*	$NetBSD: exfat.c,v 1.3 2020/02/08 12:56:56 fox Exp $	*/
+/*	$NetBSD: exfat.c,v 1.4 2021/01/24 14:37:32 tkusumi Exp $	*/
 /*
  * Copyright (c) 2017 Conrad Meyer <cem@FreeBSD.org>
  * 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.
 @@ -16,27 +16,27 @@
  * 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>
-__RCSID("$NetBSD: exfat.c,v 1.3 2020/02/08 12:56:56 fox Exp $");
+__RCSID("$NetBSD: exfat.c,v 1.4 2021/01/24 14:37:32 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>
 #include <string.h>
 @@ -317,56 +317,53 @@ exfat_find_label(FILE *fp, const struct
 		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;
 	error = 1;
 	cksect = NULL;
 	ev = (struct exfat_vbr *)read_buf(fp, 0, 512);
 	if (ev == NULL || strncmp(ev->ev_fsname, "EXFAT   ", 8) != 0)
-		goto fail;
+		goto out;
 	if (ev->ev_log_bytes_per_sect < 9 || ev->ev_log_bytes_per_sect > 12) {
 		warnx("exfat: Invalid BytesPerSectorShift");
-		goto done;
+		goto out;
+	}
 	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;
+		goto out;
 	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;
+		error = 1;
 		goto out;
+	}
 	if (show_label)
 		exfat_find_label(fp, ev, bytespersec, label, size);
-done:
+out:
 	free(cksect);
 	free(ev);
-	return (0);
+	return (error != 0);
 fail:
 	free(ev);
 	return (1);
+}