parted/0099-libparted-Add-support-for-MBR-id-GPT-GUID-and-detect.patch

From 8740cfcff3ea839dd6dc8650dec0a466e9870625 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali.rohar@gmail.com>
Date: Tue, 28 Aug 2018 21:20:01 +0200
Subject: [PATCH 099/103] libparted: Add support for MBR id, GPT GUID and
 detection of UDF filesystem

This is needed for libparted based applications (like Gparted) to correctly
choose MBR id and GPT GUID for UDF filesystem. MBR id for UDF is 0x07 and
GPT GUID is Microsoft Basic Data, see why: https://serverfault.com/a/829172

Without registering a new libparted fs code it is not possible to assign
MBR id or GPT GUID.

Detection of UDF filesystem is done by checking presence of UDF VSD (NSR02
or NSR03 identifier) and UDF AVDP at expected locations (blocks 256, -257,
-1, 512).

Signed-off-by: Brian C. Lane <bcl@redhat.com>
---
 NEWS                                  |   2 +
 libparted/fs/Makefile.am              |   1 +
 libparted/fs/udf/udf.c                | 175 ++++++++++++++++++++++++++
 libparted/labels/dos.c                |   3 +
 libparted/labels/gpt.c                |   1 +
 libparted/libparted.c                 |   4 +
 scripts/data/abi/baseline_symbols.txt |   2 +
 tests/Makefile.am                     |   1 +
 tests/t2410-dos-udf-partition-type.sh |  38 ++++++
 9 files changed, 227 insertions(+)
 create mode 100644 libparted/fs/udf/udf.c
 create mode 100644 tests/t2410-dos-udf-partition-type.sh

diff --git a/NEWS b/NEWS
index ee6efb6..45ea91c 100644
--- a/NEWS
+++ b/NEWS
@@ -47,6 +47,8 @@ GNU parted NEWS                                    -*- outline -*-
 
 ** New Features
 
+  Add support for MBR id, GPT GUID and detection of UDF filesystem.
+
   libparted-fs-resize: Work on non 512 byte sectors.
 
   Add resizepart command to resize a partition.  This works even on
diff --git a/libparted/fs/Makefile.am b/libparted/fs/Makefile.am
index d3cc8bc..cab32c7 100644
--- a/libparted/fs/Makefile.am
+++ b/libparted/fs/Makefile.am
@@ -44,6 +44,7 @@ libfs_la_SOURCES =		\
   ntfs/ntfs.c			\
   reiserfs/reiserfs.c		\
   reiserfs/reiserfs.h		\
+  udf/udf.c			\
   ufs/ufs.c			\
   xfs/platform_defs.h		\
   xfs/xfs.c			\
diff --git a/libparted/fs/udf/udf.c b/libparted/fs/udf/udf.c
new file mode 100644
index 0000000..00209e1
--- /dev/null
+++ b/libparted/fs/udf/udf.c
@@ -0,0 +1,175 @@
+/*
+    libparted - a library for manipulating disk partitions
+    Copyright (C) 2018 Free Software Foundation, Inc.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <config.h>
+
+#include <parted/parted.h>
+
+/* Read bytes using ped_geometry_read() function */
+static int read_bytes (const PedGeometry* geom, void* buffer, PedSector offset, PedSector count)
+{
+	char* sector_buffer;
+	PedSector sector_offset, sector_count, buffer_offset;
+
+	sector_offset = offset / geom->dev->sector_size;
+	sector_count = (offset + count + geom->dev->sector_size - 1) / geom->dev->sector_size - sector_offset;
+	buffer_offset = offset - sector_offset * geom->dev->sector_size;
+
+	sector_buffer = alloca (sector_count * geom->dev->sector_size);
+
+	if (!ped_geometry_read (geom, sector_buffer, sector_offset, sector_count))
+		return 0;
+
+	memcpy (buffer, sector_buffer + buffer_offset, count);
+	return 1;
+}
+
+/* Scan VSR and check for UDF VSD */
+static int check_vrs (const PedGeometry* geom, unsigned int vsdsize)
+{
+	PedSector block;
+	PedSector offset;
+	unsigned char ident[5];
+
+	/* Check only first 64 blocks, but theoretically standard does not define upper limit */
+	for (block = 0; block < 64; block++) {
+		/* VRS starts at fixed offset 32kB, it is independent of block size or vsd size */
+		offset = 32768 + block * vsdsize;
+
+		/* Read VSD identifier, it is at offset 1 */
+		if (!read_bytes (geom, ident, offset + 1, 5))
+			return 0;
+
+		/* Check for UDF identifier */
+		if (memcmp (ident, "NSR02", 5) == 0 ||
+		    memcmp (ident, "NSR03", 5) == 0)
+			return 1;
+
+		/* Unknown VSD identifier means end of VRS */
+		if (memcmp (ident, "BEA01", 5) != 0 &&
+		         memcmp (ident, "TEA01", 5) != 0 &&
+		         memcmp (ident, "BOOT2", 5) != 0 &&
+		         memcmp (ident, "CD001", 5) != 0 &&
+		         memcmp (ident, "CDW02", 5) != 0)
+			break;
+	}
+
+	return 0;
+}
+
+/* Check for UDF AVDP */
+static int check_anchor (const PedGeometry* geom, unsigned int blocksize, int rel_block)
+{
+	PedSector block;
+	unsigned char tag[16];
+
+	/* Negative block means relative to the end of device */
+	if (rel_block < 0) {
+		block = geom->length * geom->dev->sector_size / blocksize;
+		if (block <= (PedSector)(-rel_block))
+			return 0;
+		block -= (PedSector)(-rel_block);
+		if (block < 257)
+			return 0;
+	} else {
+		block = rel_block;
+	}
+
+	if (!read_bytes (geom, tag, block * blocksize, 16))
+		return 0;
+
+	/* Check for AVDP type (0x0002) */
+	if (((unsigned short)tag[0] | ((unsigned short)tag[1] << 8)) != 0x0002)
+		return 0;
+
+	/* Check that location stored in AVDP matches */
+	if (((unsigned long)tag[12] | ((unsigned long)tag[13] << 8) | ((unsigned long)tag[14] << 16) | ((unsigned long)tag[15] << 24)) != block)
+		return 0;
+
+	return 1;
+}
+
+/* Detect presence of UDF AVDP */
+static int detect_anchor(const PedGeometry* geom, unsigned int blocksize)
+{
+	/* All possible AVDP locations in preferred order */
+	static int anchors[] = { 256, -257, -1, 512 };
+	size_t i;
+
+	for (i = 0; i < sizeof (anchors)/sizeof (*anchors); i++) {
+		if (check_anchor (geom, blocksize, anchors[i]))
+			return 1;
+	}
+
+	return 0;
+}
+
+/* Detect UDF filesystem, it must have VRS and AVDP */
+static int detect_udf (const PedGeometry* geom)
+{
+	unsigned int blocksize;
+
+	/* VSD size is min(2048, UDF block size), check for block sizes <= 2048 */
+	if (check_vrs (geom, 2048)) {
+		for (blocksize = 512; blocksize <= 2048; blocksize *= 2) {
+			if (detect_anchor (geom, blocksize))
+				return 1;
+		}
+	}
+
+	/* Check for block sizes larger then 2048, maximal theoretical block size is 32kB */
+	for (blocksize = 4096; blocksize <= 32768; blocksize *= 2) {
+		if (!check_vrs (geom, blocksize))
+			continue;
+		if (detect_anchor (geom, blocksize))
+			return 1;
+	}
+
+	return 0;
+}
+
+PedGeometry*
+udf_probe (PedGeometry* geom)
+{
+	if (!detect_udf (geom))
+		return NULL;
+
+	return ped_geometry_duplicate (geom);
+}
+
+static PedFileSystemOps udf_ops = {
+	probe:		udf_probe,
+};
+
+static PedFileSystemType udf_type = {
+	next:	NULL,
+	ops:	&udf_ops,
+	name:	"udf",
+};
+
+void
+ped_file_system_udf_init ()
+{
+	ped_file_system_type_register (&udf_type);
+}
+
+void
+ped_file_system_udf_done ()
+{
+	ped_file_system_type_unregister (&udf_type);
+}
diff --git a/libparted/labels/dos.c b/libparted/labels/dos.c
index fa53020..b2b8de9 100644
--- a/libparted/labels/dos.c
+++ b/libparted/labels/dos.c
@@ -65,6 +65,7 @@ static const char MBR_BOOT_CODE[] = {
 #define PARTITION_FAT16		0x06
 #define PARTITION_NTFS		0x07
 #define PARTITION_HPFS		0x07
+#define PARTITION_UDF		0x07
 #define PARTITION_FAT32		0x0b
 #define PARTITION_FAT32_LBA	0x0c
 #define PARTITION_FAT16_LBA	0x0e
@@ -1498,6 +1499,8 @@ msdos_partition_set_system (PedPartition* part,
 	} else if (!strcmp (fs_type->name, "hfs")
 		   || !strcmp (fs_type->name, "hfs+"))
 		dos_data->system = PARTITION_HFS;
+	else if (!strcmp (fs_type->name, "udf"))
+		dos_data->system = PARTITION_UDF;
 	else if (!strcmp (fs_type->name, "sun-ufs"))
 		dos_data->system = PARTITION_SUN_UFS;
 	else if (is_linux_swap (fs_type->name))
diff --git a/libparted/labels/gpt.c b/libparted/labels/gpt.c
index 6f92a34..860f415 100644
--- a/libparted/labels/gpt.c
+++ b/libparted/labels/gpt.c
@@ -1513,6 +1513,7 @@ gpt_partition_set_system (PedPartition *part,
   if (fs_type)
     {
       if (strncmp (fs_type->name, "fat", 3) == 0
+          || strcmp (fs_type->name, "udf") == 0
           || strcmp (fs_type->name, "ntfs") == 0)
         {
           gpt_part_data->type = PARTITION_BASIC_DATA_GUID;
diff --git a/libparted/libparted.c b/libparted/libparted.c
index 3bd071d..e517875 100644
--- a/libparted/libparted.c
+++ b/libparted/libparted.c
@@ -112,6 +112,7 @@ extern void ped_file_system_fat_init (void);
 extern void ped_file_system_ext2_init (void);
 extern void ped_file_system_nilfs2_init (void);
 extern void ped_file_system_btrfs_init (void);
+extern void ped_file_system_udf_init (void);
 
 static void
 init_file_system_types ()
@@ -128,6 +129,7 @@ init_file_system_types ()
 	ped_file_system_ext2_init ();
 	ped_file_system_nilfs2_init ();
 	ped_file_system_btrfs_init ();
+	ped_file_system_udf_init ();
 }
 
 extern void ped_disk_aix_done ();
@@ -193,6 +195,7 @@ extern void ped_file_system_ufs_done (void);
 extern void ped_file_system_xfs_done (void);
 extern void ped_file_system_amiga_done (void);
 extern void ped_file_system_btrfs_done (void);
+extern void ped_file_system_udf_done (void);
 
 static void
 done_file_system_types ()
@@ -209,6 +212,7 @@ done_file_system_types ()
 	ped_file_system_xfs_done ();
 	ped_file_system_amiga_done ();
 	ped_file_system_btrfs_done ();
+	ped_file_system_udf_done ();
 }
 
 static void _done() __attribute__ ((destructor));
diff --git a/scripts/data/abi/baseline_symbols.txt b/scripts/data/abi/baseline_symbols.txt
index 9162f1a..69abd82 100644
--- a/scripts/data/abi/baseline_symbols.txt
+++ b/scripts/data/abi/baseline_symbols.txt
@@ -340,6 +340,8 @@ FUNC:ped_file_system_type_get
 FUNC:ped_file_system_type_get_next
 FUNC:ped_file_system_type_register
 FUNC:ped_file_system_type_unregister
+FUNC:ped_file_system_udf_init
+FUNC:ped_file_system_udf_done
 FUNC:ped_file_system_ufs_done
 FUNC:ped_file_system_ufs_init
 FUNC:ped_file_system_xfs_done
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 3851983..3fa75a9 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -51,6 +51,7 @@ TESTS = \
   t2310-dos-extended-2-sector-min-offset.sh \
   t2320-dos-extended-noclobber.sh \
   t2400-dos-hfs-partition-type.sh \
+  t2410-dos-udf-partition-type.sh \
   t2500-probe-corrupt-hfs.sh \
   t3000-resize-fs.sh \
   t3200-resize-partition.sh \
diff --git a/tests/t2410-dos-udf-partition-type.sh b/tests/t2410-dos-udf-partition-type.sh
new file mode 100644
index 0000000..7cc8a02
--- /dev/null
+++ b/tests/t2410-dos-udf-partition-type.sh
@@ -0,0 +1,38 @@
+#!/bin/sh
+# Ensure that an UDF partition in a dos table gets the right ID
+
+# Copyright (C) 2018 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/init.sh"; path_prepend_ ../parted
+
+dev=loop-file
+ss=$sector_size_
+n_sectors=8000
+
+dd if=/dev/null of=$dev bs=$ss seek=$n_sectors || framework_failure
+
+# create a GPT partition table
+parted -s $dev mklabel msdos \
+  mkpart pri udf 2048s 4095s > out 2>&1 || fail=1
+# expect no output
+compare /dev/null out || fail=1
+
+# Extract the "type" byte of the first partition.
+od -An -j450 -tx1 -N1 $dev > out || fail=1
+printf ' 07\n' > exp || fail=1
+compare exp out || fail=1
+
+Exit $fail
-- 
2.17.2