1 files changed, 316 insertions, 0 deletions
diff --git a/libparted/labels/loop.c b/libparted/labels/loop.c
new file mode 100644
index 0000000..45d169d
--- /dev/null
+++ b/libparted/labels/loop.c
@@ -0,0 +1,316 @@
+/*
+    libparted - a library for manipulating disk partitions
+    Copyright (C) 1999-2000, 2007-2014, 2019-2023 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>
+#include <parted/debug.h>
+#include <parted/endian.h>
+#include <stdbool.h>
+
+#include "pt-tools.h"
+
+#if ENABLE_NLS
+#  include <libintl.h>
+#  define _(String) dgettext (PACKAGE, String)
+#else
+#  define _(String) (String)
+#endif /* ENABLE_NLS */
+
+#define	LOOP_SIGNATURE		"GNU Parted Loopback 0"
+
+static PedDiskType loop_disk_type;
+
+static PedDisk* loop_alloc (const PedDevice* dev);
+static void loop_free (PedDisk* disk);
+
+static int
+loop_probe (const PedDevice* dev)
+{
+	PedDisk *disk = loop_alloc (dev);
+	if (!disk)
+		goto error;
+
+	void *buf;
+	if (!ptt_read_sector (dev, 0, &buf))
+		goto error_destroy_disk;
+        int found_sig = !strncmp (buf, LOOP_SIGNATURE, strlen (LOOP_SIGNATURE));
+        free (buf);
+
+	int result;
+	if (found_sig) {
+		result = 1;
+	} else {
+		PedGeometry*	geom;
+
+		geom = ped_geometry_new (dev, 0, disk->dev->length);
+		if (!geom)
+			goto error_destroy_disk;
+		result = ped_file_system_probe (geom) != NULL;
+		ped_geometry_destroy (geom);
+	}
+	loop_free (disk);
+	return result;
+
+error_destroy_disk:
+	loop_free (disk);
+error:
+	return 0;
+}
+
+static PedDisk*
+loop_alloc (const PedDevice* dev)
+{
+	PED_ASSERT (dev != NULL);
+
+	if (dev->length < 256)
+		return NULL;
+	PedDisk *disk = _ped_disk_alloc ((PedDevice*)dev, &loop_disk_type);
+	PED_ASSERT (disk != NULL);
+	PedGeometry *geom = ped_geometry_new (dev, 0, dev->length);
+	PED_ASSERT (geom != NULL);
+	PedPartition *part = ped_partition_new (disk, PED_PARTITION_NORMAL,
+						NULL, geom->start, geom->end);
+	PED_ASSERT (part != NULL);
+	ped_geometry_destroy (geom);
+	PedConstraint *constraint_any = ped_constraint_any (dev);
+	if (!ped_disk_add_partition (disk, part, constraint_any))
+		goto error;
+	ped_constraint_destroy (constraint_any);
+	return disk;
+ error:
+	ped_constraint_destroy (constraint_any);
+	ped_disk_destroy (disk);
+	return NULL;
+}
+
+static PedDisk*
+loop_duplicate (const PedDisk* disk)
+{
+	return ped_disk_new_fresh (disk->dev, &loop_disk_type);
+}
+
+static void
+loop_free (PedDisk* disk)
+{
+	PED_ASSERT (disk != NULL);
+
+	_ped_disk_free (disk);
+}
+
+static int
+loop_read (PedDisk* disk)
+{
+	PedDevice*		dev = NULL;
+	PedGeometry*		geom;
+	PedFileSystemType*	fs_type;
+	PedPartition*		part;
+	PedConstraint*		constraint_any;
+
+	PED_ASSERT (disk != NULL);
+	dev = disk->dev;
+	constraint_any = ped_constraint_any (dev);
+
+	ped_disk_delete_all (disk);
+
+	void *buf;
+	if (!ptt_read_sector (dev, 0, &buf))
+		goto error;
+
+        int found_sig = !strncmp (buf, LOOP_SIGNATURE, strlen (LOOP_SIGNATURE));
+        free (buf);
+	geom = ped_geometry_new (dev, 0, dev->length);
+	if (!geom)
+		goto error;
+
+	fs_type = ped_file_system_probe (geom);
+	if (!fs_type && !found_sig)
+		goto error_free_geom;
+
+	part = ped_partition_new (disk, PED_PARTITION_NORMAL,
+                                  fs_type, geom->start, geom->end);
+	ped_geometry_destroy (geom);
+	if (!part)
+		goto error;
+
+	if (!ped_disk_add_partition (disk, part, constraint_any))
+		goto error;
+	ped_constraint_destroy (constraint_any);
+	return 1;
+
+error_free_geom:
+	ped_geometry_destroy (geom);
+error:
+	ped_constraint_destroy (constraint_any);
+	return 0;
+}
+
+#ifndef DISCOVER_ONLY
+static int
+loop_write (const PedDisk* disk)
+{
+	size_t buflen = disk->dev->sector_size;
+	char *buf = alloca (buflen);
+	PedPartition *part = ped_disk_get_partition (disk, 1);
+	/* if there is already a filesystem on the disk, we don't need to write the signature */
+	if (part && part->fs_type)
+		return 1;
+	if (!ped_device_read (disk->dev, buf, 0, 1))
+		return 0;
+	strcpy (buf, LOOP_SIGNATURE);
+
+        return ped_device_write (disk->dev, buf, 0, 1);
+}
+#endif /* !DISCOVER_ONLY */
+
+static PedPartition*
+loop_partition_new (const PedDisk* disk, PedPartitionType part_type,
+		    const PedFileSystemType* fs_type,
+		    PedSector start, PedSector end)
+{
+	PedPartition*	part;
+
+	part = _ped_partition_alloc (disk, part_type, fs_type, start, end);
+	if (!part)
+		return NULL;
+	part->disk_specific = NULL;
+	return part;
+}
+
+static PedPartition*
+loop_partition_duplicate (const PedPartition* part)
+{
+	PedPartition* result;
+
+	result = ped_partition_new (part->disk, part->type, part->fs_type,
+				    part->geom.start, part->geom.end);
+	if (result == NULL)
+		return NULL;
+	result->num = part->num;
+	return result;
+}
+
+static void
+loop_partition_destroy (PedPartition* part)
+{
+	free (part);
+}
+
+static int
+loop_partition_set_system (PedPartition* part, const PedFileSystemType* fs_type)
+{
+	part->fs_type = fs_type;
+	return 1;
+}
+
+static int
+loop_partition_set_flag (PedPartition* part, PedPartitionFlag flag, int state)
+{
+	return 0;
+}
+
+static int
+loop_partition_get_flag (const PedPartition* part, PedPartitionFlag flag)
+{
+	return 0;
+}
+
+static int
+loop_partition_align (PedPartition* part, const PedConstraint* constraint)
+{
+	PedGeometry*	new_geom;
+
+	new_geom = ped_constraint_solve_nearest (constraint, &part->geom);
+	if (!new_geom) {
+		ped_exception_throw (
+			PED_EXCEPTION_ERROR,
+			PED_EXCEPTION_CANCEL,
+			_("Unable to satisfy all constraints on the "
+			  "partition."));
+		return 0;
+	}
+	ped_geometry_set (&part->geom, new_geom->start, new_geom->length);
+	ped_geometry_destroy (new_geom);
+	return 1;
+}
+
+static int
+loop_partition_is_flag_available (const PedPartition* part,
+	       			  PedPartitionFlag flag)
+{
+	return 0;
+}
+
+static int
+loop_partition_enumerate (PedPartition* part)
+{
+	part->num = 1;
+	return 1;
+}
+
+static int
+loop_alloc_metadata (PedDisk* disk)
+{
+	return 1;
+}
+
+static int
+loop_get_max_primary_partition_count (const PedDisk* disk)
+{
+	return 1;
+}
+
+static bool
+loop_get_max_supported_partition_count (const PedDisk* disk, int *max_n)
+{
+	*max_n = 1;
+	return true;
+}
+
+#include "pt-common.h"
+PT_define_limit_functions (loop)
+
+static PedDiskOps loop_disk_ops = {
+	clobber:		NULL,
+	write:			NULL_IF_DISCOVER_ONLY (loop_write),
+
+	partition_set_name:	NULL,
+	partition_get_name:	NULL,
+
+	PT_op_function_initializers (loop)
+};
+
+static PedDiskType loop_disk_type = {
+	next:		NULL,
+	name:		"loop",
+	ops:		&loop_disk_ops,
+	features:	0
+};
+
+void
+ped_disk_loop_init ()
+{
+	ped_disk_type_register (&loop_disk_type);
+}
+
+void
+ped_disk_loop_done ()
+{
+	ped_disk_type_unregister (&loop_disk_type);
+}