/*
 * ntfs-3g_apply.c
 *
 * Apply a WIM image directly to an NTFS volume using libntfs-3g.  Restore as
 * much information as possible, including security data, file attributes, DOS
 * names, and alternate data streams.
 *
 * Note: because NTFS-3g offers inode-based interfaces, we actually don't need
 * to deal with paths at all!  (Other than for error messages.)
 */

/*
 * Copyright (C) 2012, 2013, 2014, 2015 Eric Biggers
 *
 * This file is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 3 of the License, or (at your option) any
 * later version.
 *
 * This file 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 Lesser General Public License for more
 * details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this file; if not, see http://www.gnu.org/licenses/.
 */

#ifdef HAVE_CONFIG_H
#  include "config.h"
#endif

#include <locale.h>
#include <string.h>

#include <ntfs-3g/attrib.h>
#include <ntfs-3g/reparse.h>
#include <ntfs-3g/security.h>

#include "wimlib/assert.h"
#include "wimlib/apply.h"
#include "wimlib/blob_table.h"
#include "wimlib/dentry.h"
#include "wimlib/encoding.h"
#include "wimlib/error.h"
#include "wimlib/metadata.h"
#include "wimlib/ntfs_3g.h"
#include "wimlib/reparse.h"
#include "wimlib/security.h"
#include "wimlib/security_descriptor.h"

static int
ntfs_3g_get_supported_features(const char *target,
			       struct wim_features *supported_features)
{
	supported_features->archive_files             = 1;
	supported_features->hidden_files              = 1;
	supported_features->system_files              = 1;
	supported_features->compressed_files          = 1;
	supported_features->not_context_indexed_files = 1;
	supported_features->named_data_streams        = 1;
	supported_features->hard_links                = 1;
	supported_features->reparse_points            = 1;
	supported_features->security_descriptors      = 1;
	supported_features->short_names               = 1;
	supported_features->timestamps                = 1;
	supported_features->case_sensitive_filenames  = 1;
	return 0;
}

struct ntfs_3g_apply_ctx {
	/* Extract flags, the pointer to the WIMStruct, etc.  */
	struct apply_ctx common;

	/* Pointer to the open NTFS volume  */
	ntfs_volume *vol;

	ntfs_attr *open_attrs[MAX_OPEN_FILES];
	unsigned num_open_attrs;
	ntfs_inode *open_inodes[MAX_OPEN_FILES];
	unsigned num_open_inodes;

	struct reparse_buffer_disk rpbuf;
	u8 *reparse_ptr;

	/* Offset in the blob currently being read  */
	u64 offset;

	unsigned num_reparse_inodes;
	ntfs_inode *ntfs_reparse_inodes[MAX_OPEN_FILES];
	struct wim_inode *wim_reparse_inodes[MAX_OPEN_FILES];
};

static size_t
sid_size(const wimlib_SID *sid)
{
	return offsetof(wimlib_SID, sub_authority) +
		sizeof(le32) * sid->sub_authority_count;
}

/*
 * sd_fixup - Fix up a Windows NT security descriptor for libntfs-3g.
 *
 * libntfs-3g validates security descriptors before setting them, but old
 * versions contain bugs causing it to reject unusual but valid security
 * descriptors:
 *
 * - Versions before 2013.1.13 reject security descriptors ending with an empty
 *   SACL (System Access Control List).  This bug can be worked around either by
 *   moving the empty SACL earlier in the security descriptor or by removing the
 *   SACL entirely.  The latter work-around is valid because an empty SACL is
 *   equivalent to a "null", or non-existent, SACL.
 * - Versions up to and including 2013.1.13 reject security descriptors ending
 *   with an empty DACL (Discretionary Access Control List).  This is very
 *   similar to the SACL bug and should be fixed in the next release after
 *   2013.1.13.  However, removing the DACL is not a valid workaround because
 *   this changes the meaning of the security descriptor--- an empty DACL allows
 *   no access, whereas a "null" DACL allows all access.
 *
 * If the security descriptor was fixed, this function returns an allocated
 * buffer containing the fixed security descriptor, and its size is updated.
 * Otherwise (or if no memory is available) the original descriptor is returned.
 */
static u8 *
sd_fixup(const u8 *_desc, size_t *size_p)
{
	u32 owner_offset, group_offset, dacl_offset;
#if !defined(HAVE_NTFS_MNT_RDONLY)
	u32 sacl_offset;
#endif
	bool owner_valid, group_valid;
	size_t size = *size_p;
	const wimlib_SECURITY_DESCRIPTOR_RELATIVE *desc =
			(const wimlib_SECURITY_DESCRIPTOR_RELATIVE*)_desc;
	wimlib_SECURITY_DESCRIPTOR_RELATIVE *desc_new;
	const wimlib_SID *owner, *group, *sid;

	/* Don't attempt to fix clearly invalid security descriptors.  */
	if (size < sizeof(wimlib_SECURITY_DESCRIPTOR_RELATIVE))
		return (u8*)_desc;

	if (le16_to_cpu(desc->control) & wimlib_SE_DACL_PRESENT)
		dacl_offset = le32_to_cpu(desc->dacl_offset);
	else
		dacl_offset = 0;

#if !defined(HAVE_NTFS_MNT_RDONLY)
	if (le16_to_cpu(desc->control) & wimlib_SE_SACL_PRESENT)
		sacl_offset = le32_to_cpu(desc->sacl_offset);
	else
		sacl_offset = 0;
#endif

	/* Check if the security descriptor will be affected by one of the bugs.
	 * If not, do nothing and return.
	 *
	 * Note: HAVE_NTFS_MNT_RDONLY is defined if libntfs-3g is
	 * version 2013.1.13 or later.  */
	if (!(
	#if !defined(HAVE_NTFS_MNT_RDONLY)
	    (sacl_offset != 0 && sacl_offset == size - sizeof(wimlib_ACL)) ||
	#endif
	    (dacl_offset != 0 && dacl_offset == size - sizeof(wimlib_ACL))))
		return (u8*)_desc;

	owner_offset = le32_to_cpu(desc->owner_offset);
	group_offset = le32_to_cpu(desc->group_offset);
	owner = (const wimlib_SID*)((const u8*)desc + owner_offset);
	group = (const wimlib_SID*)((const u8*)desc + group_offset);

	/* We'll try to move the owner or group SID to the end of the security
	 * descriptor to avoid the bug.  This is only possible if at least one
	 * is valid.  */
	owner_valid = (owner_offset != 0) &&
			(owner_offset % 4 == 0) &&
			(owner_offset <= size - sizeof(SID)) &&
			(owner_offset + sid_size(owner) <= size) &&
			(owner_offset >= sizeof(wimlib_SECURITY_DESCRIPTOR_RELATIVE));
	group_valid = (group_offset != 0) &&
			(group_offset % 4 == 0) &&
			(group_offset <= size - sizeof(SID)) &&
			(group_offset + sid_size(group) <= size) &&
			(group_offset >= sizeof(wimlib_SECURITY_DESCRIPTOR_RELATIVE));
	if (owner_valid) {
		sid = owner;
	} else if (group_valid) {
		sid = group;
	} else {
		return (u8*)_desc;
	}

	desc_new = MALLOC(size + sid_size(sid));
	if (!desc_new)
		return (u8*)_desc;

	memcpy(desc_new, desc, size);
	if (owner_valid)
		desc_new->owner_offset = cpu_to_le32(size);
	else if (group_valid)
		desc_new->group_offset = cpu_to_le32(size);
	memcpy((u8*)desc_new + size, sid, sid_size(sid));
	*size_p = size + sid_size(sid);
	return (u8*)desc_new;
}

/* Set the security descriptor @desc of size @desc_size on the NTFS inode @ni.
  */
static int
ntfs_3g_set_security_descriptor(ntfs_inode *ni, const void *desc, size_t desc_size)
{
	struct SECURITY_CONTEXT sec_ctx;
	u8 *desc_fixed;
	int ret = 0;

	memset(&sec_ctx, 0, sizeof(sec_ctx));
	sec_ctx.vol = ni->vol;

	desc_fixed = sd_fixup(desc, &desc_size);

	if (ntfs_set_ntfs_acl(&sec_ctx, ni, desc_fixed, desc_size, 0))
		ret = WIMLIB_ERR_SET_SECURITY;

	if (desc_fixed != desc)
		FREE(desc_fixed);

	return ret;
}

static int
ntfs_3g_set_timestamps(ntfs_inode *ni, const struct wim_inode *inode)
{
	u64 times[3] = {
		inode->i_creation_time,
		inode->i_last_write_time,
		inode->i_last_access_time,
	};

	if (ntfs_inode_set_times(ni, (const char *)times, sizeof(times), 0))
		return WIMLIB_ERR_SET_TIMESTAMPS;
	return 0;
}

/* Restore the timestamps on the NTFS inode corresponding to @inode.  */
static int
ntfs_3g_restore_timestamps(ntfs_volume *vol, const struct wim_inode *inode)
{
	ntfs_inode *ni;
	int res;

	ni = ntfs_inode_open(vol, inode->i_mft_no);
	if (!ni)
		goto fail;

	res = ntfs_3g_set_timestamps(ni, inode);

	if (ntfs_inode_close(ni) || res)
		goto fail;

	return 0;

fail:
	ERROR_WITH_ERRNO("Failed to update timestamps of \"%s\" in NTFS volume",
			 dentry_full_path(inode_first_extraction_dentry(inode)));
	return WIMLIB_ERR_SET_TIMESTAMPS;
}

/* Restore the DOS name of the @dentry.
 * This closes both @ni and @dir_ni.
 * If either is NULL, then they are opened temporarily.  */
static int
ntfs_3g_restore_dos_name(ntfs_inode *ni, ntfs_inode *dir_ni,
			 struct wim_dentry *dentry, ntfs_volume *vol)
{
	int ret;
	const char *dos_name;
	size_t dos_name_nbytes;

	/* Note: ntfs_set_ntfs_dos_name() closes both inodes (even if it fails).
	 * And it takes in a multibyte string, even though it translates it to
	 * UTF-16LE internally... which is annoying because we currently have
	 * the UTF-16LE string but not the multibyte string.  */

	ret = utf16le_get_tstr(dentry->d_short_name, dentry->d_short_name_nbytes,
			       &dos_name, &dos_name_nbytes);
	if (ret)
		goto out_close;

	if (!dir_ni)
		dir_ni = ntfs_inode_open(vol, dentry->d_parent->d_inode->i_mft_no);
	if (!ni)
		ni = ntfs_inode_open(vol, dentry->d_inode->i_mft_no);
	if (dir_ni && ni) {
		ret = ntfs_set_ntfs_dos_name(ni, dir_ni,
					     dos_name, dos_name_nbytes, 0);
		dir_ni = NULL;
		ni = NULL;
	} else {
		ret = -1;
	}
	utf16le_put_tstr(dos_name);
	if (ret) {
		ERROR_WITH_ERRNO("Failed to set DOS name of \"%s\" in NTFS "
				 "volume", dentry_full_path(dentry));
		ret = WIMLIB_ERR_SET_SHORT_NAME;
		goto out_close;
	}

	/* Unlike most other NTFS-3g functions, ntfs_set_ntfs_dos_name()
	 * changes the directory's last modification timestamp...
	 * Change it back.  */
	return ntfs_3g_restore_timestamps(vol, dentry->d_parent->d_inode);

out_close:
	/* ntfs_inode_close() can take a NULL argument, but it's probably best
	 * not to rely on this behavior.  */
	if (ni)
		ntfs_inode_close(ni);
	if (dir_ni)
		ntfs_inode_close(dir_ni);
	return ret;
}

static int
ntfs_3g_restore_reparse_point(ntfs_inode *ni, const struct wim_inode *inode,
			      unsigned blob_size, struct ntfs_3g_apply_ctx *ctx)
{
	complete_reparse_point(&ctx->rpbuf, inode, blob_size);

	if (ntfs_set_ntfs_reparse_data(ni, (const char *)&ctx->rpbuf,
				       REPARSE_DATA_OFFSET + blob_size, 0))
	{
		ERROR_WITH_ERRNO("Failed to set reparse data on \"%s\"",
				 dentry_full_path(
					inode_first_extraction_dentry(inode)));
		return WIMLIB_ERR_SET_REPARSE_DATA;
	}

	return 0;
}


/*
 * Create empty attributes (named data streams and potentially a reparse point)
 * for the specified file, if there are any.
 *
 * Since these won't have blob descriptors, they won't show up in the call to
 * extract_blob_list().  Hence the need for the special case.
 */
static int
ntfs_3g_create_empty_attributes(ntfs_inode *ni,
				const struct wim_inode *inode,
				struct ntfs_3g_apply_ctx *ctx)
{

	for (unsigned i = 0; i < inode->i_num_streams; i++) {

		const struct wim_inode_stream *strm = &inode->i_streams[i];
		int ret;

		if (stream_blob_resolved(strm) != NULL)
			continue;

		if (strm->stream_type == STREAM_TYPE_REPARSE_POINT) {
			ret = ntfs_3g_restore_reparse_point(ni, inode, 0, ctx);
			if (ret)
				return ret;
		} else if (stream_is_named_data_stream(strm)) {
			if (ntfs_attr_add(ni, AT_DATA, strm->stream_name,
					  utf16le_len_chars(strm->stream_name),
					  NULL, 0))
			{
				ERROR_WITH_ERRNO("Failed to create named data "
						 "stream of \"%s\"",
						 dentry_full_path(
					inode_first_extraction_dentry(inode)));
				return WIMLIB_ERR_NTFS_3G;
			}
		}
	}
	return 0;
}

/* Set attributes, security descriptor, and timestamps on the NTFS inode @ni.
 */
static int
ntfs_3g_set_metadata(ntfs_inode *ni, const struct wim_inode *inode,
		     const struct ntfs_3g_apply_ctx *ctx)
{
	int extract_flags;
	const struct wim_security_data *sd;
	struct wim_dentry *one_dentry;
	int ret;

	extract_flags = ctx->common.extract_flags;
	sd = wim_get_current_security_data(ctx->common.wim);
	one_dentry = inode_first_extraction_dentry(inode);

	/* Attributes  */
	if (!(extract_flags & WIMLIB_EXTRACT_FLAG_NO_ATTRIBUTES)) {
		u32 attrib = inode->i_attributes;

		attrib &= ~(FILE_ATTRIBUTE_SPARSE_FILE |
			    FILE_ATTRIBUTE_ENCRYPTED);

		if (ntfs_set_ntfs_attrib(ni, (const char *)&attrib,
					 sizeof(attrib), 0))
		{
			ERROR_WITH_ERRNO("Failed to set attributes on \"%s\" "
					 "in NTFS volume",
					 dentry_full_path(one_dentry));
			return WIMLIB_ERR_SET_ATTRIBUTES;
		}
	}

	/* Security descriptor  */
	if (inode_has_security_descriptor(inode)
	    && !(extract_flags & WIMLIB_EXTRACT_FLAG_NO_ACLS))
	{
		const void *desc;
		size_t desc_size;

		desc = sd->descriptors[inode->i_security_id];
		desc_size = sd->sizes[inode->i_security_id];

		ret = ntfs_3g_set_security_descriptor(ni, desc, desc_size);
		if (ret) {
			if (wimlib_print_errors) {
				ERROR_WITH_ERRNO("Failed to set security descriptor "
						 "on \"%s\" in NTFS volume",
						 dentry_full_path(one_dentry));
				fprintf(wimlib_error_file,
					"The security descriptor is: ");
				print_byte_field(desc, desc_size, wimlib_error_file);
				fprintf(wimlib_error_file, "\n");
			}
			return ret;
		}
	}

	/* Timestamps  */
	ret = ntfs_3g_set_timestamps(ni, inode);
	if (ret) {
		ERROR_WITH_ERRNO("Failed to set timestamps on \"%s\" "
				 "in NTFS volume",
				 dentry_full_path(one_dentry));
		return ret;
	}
	return 0;
}

/* Recursively creates all the subdirectories of @dir, which has been created as
 * the NTFS inode @dir_ni.  */
static int
ntfs_3g_create_dirs_recursive(ntfs_inode *dir_ni, struct wim_dentry *dir,
			      struct ntfs_3g_apply_ctx *ctx)
{
	struct wim_dentry *child;

	for_dentry_child(child, dir) {
		ntfs_inode *ni;
		int ret;

		if (!(child->d_inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY))
			continue;
		if (!will_extract_dentry(child))
			continue;

		ni = ntfs_create(dir_ni, 0, child->d_extraction_name,
				 child->d_extraction_name_nchars, S_IFDIR);
		if (!ni) {
			ERROR_WITH_ERRNO("Error creating \"%s\" in NTFS volume",
					 dentry_full_path(child));
			return WIMLIB_ERR_NTFS_3G;
		}

		child->d_inode->i_mft_no = ni->mft_no;

		ret = report_file_created(&ctx->common);
		if (!ret)
			ret = ntfs_3g_set_metadata(ni, child->d_inode, ctx);
		if (!ret)
			ret = ntfs_3g_create_empty_attributes(ni, child->d_inode, ctx);
		if (!ret)
			ret = ntfs_3g_create_dirs_recursive(ni, child, ctx);

		if (ntfs_inode_close_in_dir(ni, dir_ni) && !ret) {
			ERROR_WITH_ERRNO("Error closing \"%s\" in NTFS volume",
					 dentry_full_path(child));
			ret = WIMLIB_ERR_NTFS_3G;
		}
		if (ret)
			return ret;
	}
	return 0;
}

/* For each WIM dentry in the @root tree that represents a directory, create the
 * corresponding directory in the NTFS volume @ctx->vol.  */
static int
ntfs_3g_create_directories(struct wim_dentry *root,
			   struct list_head *dentry_list,
			   struct ntfs_3g_apply_ctx *ctx)
{
	ntfs_inode *root_ni;
	int ret;
	struct wim_dentry *dentry;

	/* Create the directories using POSIX names.  */

	root_ni = ntfs_inode_open(ctx->vol, FILE_root);
	if (!root_ni) {
		ERROR_WITH_ERRNO("Can't open root of NTFS volume");
		return WIMLIB_ERR_NTFS_3G;
	}

	root->d_inode->i_mft_no = FILE_root;

	ret = ntfs_3g_create_dirs_recursive(root_ni, root, ctx);

	if (ntfs_inode_close(root_ni) && !ret) {
		ERROR_WITH_ERRNO("Error closing root of NTFS volume");
		ret = WIMLIB_ERR_NTFS_3G;
	}
	if (ret)
		return ret;

	/* Set the DOS name of any directory that has one.  */
	list_for_each_entry(dentry, dentry_list, d_extraction_list_node) {
		if (!(dentry->d_inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY))
			continue;
		if (!dentry_has_short_name(dentry))
			continue;
		ret = ntfs_3g_restore_dos_name(NULL, NULL, dentry, ctx->vol);
		if (ret)
			return ret;
		ret = report_file_created(&ctx->common);
		if (ret)
			return ret;
	}
	return 0;
}

/* When creating an inode that will have a short (DOS) name, we create it using
 * the long name associated with the short name.  This ensures that the short
 * name gets associated with the correct long name.  */
static struct wim_dentry *
ntfs_3g_first_extraction_alias(struct wim_inode *inode)
{
	struct wim_dentry *dentry;

	inode_for_each_extraction_alias(dentry, inode)
		if (dentry_has_short_name(dentry))
			return dentry;
	return inode_first_extraction_dentry(inode);
}

/*
 * Add a hard link for the NTFS inode @ni at the location corresponding to the
 * WIM dentry @dentry.
 *
 * The parent directory must have already been created on the NTFS volume.
 *
 * Returns 0 on success; returns WIMLIB_ERR_NTFS_3G and sets errno on failure.
 */
static int
ntfs_3g_add_link(ntfs_inode *ni, struct wim_dentry *dentry)
{
	ntfs_inode *dir_ni;
	int res;

	/* Open the inode of the parent directory.  */
	dir_ni = ntfs_inode_open(ni->vol, dentry->d_parent->d_inode->i_mft_no);
	if (!dir_ni)
		goto fail;

	/* Create the link.  */
	res = ntfs_link(ni, dir_ni, dentry->d_extraction_name,
			dentry->d_extraction_name_nchars);

	/* Close the parent directory.  */
	if (ntfs_inode_close(dir_ni) || res)
		goto fail;

	return 0;

fail:
	ERROR_WITH_ERRNO("Can't create link \"%s\" in NTFS volume",
			 dentry_full_path(dentry));
	return WIMLIB_ERR_NTFS_3G;
}

static int
ntfs_3g_create_nondirectory(struct wim_inode *inode,
			    struct ntfs_3g_apply_ctx *ctx)
{
	struct wim_dentry *first_dentry;
	ntfs_inode *dir_ni;
	ntfs_inode *ni;
	struct wim_dentry *dentry;
	int ret;

	first_dentry = ntfs_3g_first_extraction_alias(inode);

	/* Create first link.  */

	dir_ni = ntfs_inode_open(ctx->vol, first_dentry->d_parent->d_inode->i_mft_no);
	if (!dir_ni) {
		ERROR_WITH_ERRNO("Can't open \"%s\" in NTFS volume",
				 dentry_full_path(first_dentry->d_parent));
		return WIMLIB_ERR_NTFS_3G;
	}

	ni = ntfs_create(dir_ni, 0, first_dentry->d_extraction_name,
			 first_dentry->d_extraction_name_nchars, S_IFREG);

	if (!ni) {
		ERROR_WITH_ERRNO("Can't create \"%s\" in NTFS volume",
				 dentry_full_path(first_dentry));
		ntfs_inode_close(dir_ni);
		return WIMLIB_ERR_NTFS_3G;
	}

	inode->i_mft_no = ni->mft_no;

	/* Set short name if present.  */
	if (dentry_has_short_name(first_dentry)) {

		ret = ntfs_3g_restore_dos_name(ni, dir_ni, first_dentry, ctx->vol);

		/* ntfs_3g_restore_dos_name() closed both 'ni' and 'dir_ni'.  */

		if (ret)
			return ret;

		/* Reopen the inode.  */
		ni = ntfs_inode_open(ctx->vol, inode->i_mft_no);
		if (!ni) {
			ERROR_WITH_ERRNO("Failed to reopen \"%s\" "
					 "in NTFS volume",
					 dentry_full_path(first_dentry));
			return WIMLIB_ERR_NTFS_3G;
		}
	} else {
		/* Close the directory in which the first link was created.  */
		if (ntfs_inode_close(dir_ni)) {
			ERROR_WITH_ERRNO("Failed to close \"%s\" in NTFS volume",
					 dentry_full_path(first_dentry->d_parent));
			ret = WIMLIB_ERR_NTFS_3G;
			goto out_close_ni;
		}
	}

	/* Create additional links if present.  */
	inode_for_each_extraction_alias(dentry, inode) {
		if (dentry != first_dentry) {
			ret = ntfs_3g_add_link(ni, dentry);
			if (ret)
				goto out_close_ni;
		}
	}

	/* Set metadata.  */
	ret = ntfs_3g_set_metadata(ni, inode, ctx);
	if (ret)
		goto out_close_ni;

	ret = ntfs_3g_create_empty_attributes(ni, inode, ctx);

out_close_ni:
	/* Close the inode.  */
	if (ntfs_inode_close(ni) && !ret) {
		ERROR_WITH_ERRNO("Error closing \"%s\" in NTFS volume",
				 dentry_full_path(first_dentry));
		ret = WIMLIB_ERR_NTFS_3G;
	}
	return ret;
}

/* For each WIM dentry in the @dentry_list that represents a nondirectory file,
 * create the corresponding nondirectory file in the NTFS volume.
 *
 * Directories must have already been created.  */
static int
ntfs_3g_create_nondirectories(struct list_head *dentry_list,
			      struct ntfs_3g_apply_ctx *ctx)
{
	struct wim_dentry *dentry;
	struct wim_inode *inode;
	int ret;

	list_for_each_entry(dentry, dentry_list, d_extraction_list_node) {
		inode = dentry->d_inode;
		if (inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY)
			continue;
		if (dentry == inode_first_extraction_dentry(inode)) {
			ret = ntfs_3g_create_nondirectory(inode, ctx);
			if (ret)
				return ret;
		}
		ret = report_file_created(&ctx->common);
		if (ret)
			return ret;
	}
	return 0;
}

static int
ntfs_3g_begin_extract_blob_instance(struct blob_descriptor *blob,
				    ntfs_inode *ni,
				    struct wim_inode *inode,
				    const struct wim_inode_stream *strm,
				    struct ntfs_3g_apply_ctx *ctx)
{
	struct wim_dentry *one_dentry = inode_first_extraction_dentry(inode);
	size_t stream_name_nchars;
	ntfs_attr *attr;

	if (unlikely(strm->stream_type == STREAM_TYPE_REPARSE_POINT)) {

		if (blob->size > REPARSE_DATA_MAX_SIZE) {
			ERROR("Reparse data of \"%s\" has size "
			      "%"PRIu64" bytes (exceeds %u bytes)",
			      dentry_full_path(one_dentry),
			      blob->size, REPARSE_DATA_MAX_SIZE);
			return WIMLIB_ERR_INVALID_REPARSE_DATA;
		}
		ctx->reparse_ptr = ctx->rpbuf.rpdata;
		ctx->ntfs_reparse_inodes[ctx->num_reparse_inodes] = ni;
		ctx->wim_reparse_inodes[ctx->num_reparse_inodes] = inode;
		ctx->num_reparse_inodes++;
		return 0;
	}

	/* It's a data stream (may be unnamed or named).  */
	wimlib_assert(strm->stream_type == STREAM_TYPE_DATA);

	stream_name_nchars = utf16le_len_chars(strm->stream_name);

	if (stream_name_nchars &&
	    (ntfs_attr_add(ni, AT_DATA, strm->stream_name,
			   stream_name_nchars, NULL, 0)))
	{
		ERROR_WITH_ERRNO("Failed to create named data stream of \"%s\"",
				 dentry_full_path(one_dentry));
		return WIMLIB_ERR_NTFS_3G;
	}

	/* This should be ensured by extract_blob_list()  */
	wimlib_assert(ctx->num_open_attrs < MAX_OPEN_FILES);

	attr = ntfs_attr_open(ni, AT_DATA, strm->stream_name,
			      stream_name_nchars);
	if (!attr) {
		ERROR_WITH_ERRNO("Failed to open data stream of \"%s\"",
				 dentry_full_path(one_dentry));
		return WIMLIB_ERR_NTFS_3G;
	}
	ctx->open_attrs[ctx->num_open_attrs++] = attr;
	ntfs_attr_truncate_solid(attr, blob->size);
	return 0;
}

static int
ntfs_3g_cleanup_blob_extract(struct ntfs_3g_apply_ctx *ctx)
{
	int ret = 0;

	for (unsigned i = 0; i < ctx->num_open_attrs; i++) {
		if (ntfs_attr_pclose(ctx->open_attrs[i]))
			ret = -1;
		ntfs_attr_close(ctx->open_attrs[i]);
	}

	ctx->num_open_attrs = 0;

	for (unsigned i = 0; i < ctx->num_open_inodes; i++) {
		if (ntfs_inode_close(ctx->open_inodes[i]))
			ret = -1;
	}
	ctx->num_open_inodes = 0;

	ctx->offset = 0;
	ctx->reparse_ptr = NULL;
	ctx->num_reparse_inodes = 0;
	return ret;
}

static ntfs_inode *
ntfs_3g_open_inode(struct wim_inode *inode, struct ntfs_3g_apply_ctx *ctx)
{
	ntfs_inode *ni;

	/* If the same blob is being extracted to multiple streams of the same
	 * inode, then we must only open the inode once.  */
	if (unlikely(inode->i_num_streams > 1)) {
		for (unsigned i = 0; i < ctx->num_open_inodes; i++) {
			if (ctx->open_inodes[i]->mft_no == inode->i_mft_no) {
				ni = ctx->open_inodes[i];
				goto have_inode;
			}
		}
	}

	ni = ntfs_inode_open(ctx->vol, inode->i_mft_no);
	if (unlikely(!ni)) {
		ERROR_WITH_ERRNO("Can't open \"%s\" in NTFS volume",
				 dentry_full_path(
					inode_first_extraction_dentry(inode)));
		return NULL;
	}

have_inode:
	ctx->open_inodes[ctx->num_open_inodes++] = ni;
	return ni;
}

static int
ntfs_3g_begin_extract_blob(struct blob_descriptor *blob, void *_ctx)
{
	struct ntfs_3g_apply_ctx *ctx = _ctx;
	const struct blob_extraction_target *targets = blob_extraction_targets(blob);
	int ret;
	ntfs_inode *ni;

	for (u32 i = 0; i < blob->out_refcnt; i++) {
		ret = WIMLIB_ERR_NTFS_3G;
		ni = ntfs_3g_open_inode(targets[i].inode, ctx);
		if (!ni)
			goto out_cleanup;

		ret = ntfs_3g_begin_extract_blob_instance(blob, ni,
							  targets[i].inode,
							  targets[i].stream, ctx);
		if (ret)
			goto out_cleanup;
	}
	ret = 0;
	goto out;

out_cleanup:
	ntfs_3g_cleanup_blob_extract(ctx);
out:
	return ret;
}

static int
ntfs_3g_extract_chunk(const void *chunk, size_t size, void *_ctx)
{
	struct ntfs_3g_apply_ctx *ctx = _ctx;
	s64 res;

	for (unsigned i = 0; i < ctx->num_open_attrs; i++) {
		res = ntfs_attr_pwrite(ctx->open_attrs[i],
				       ctx->offset, size, chunk);
		if (res != size) {
			ERROR_WITH_ERRNO("Error writing data to NTFS volume");
			return WIMLIB_ERR_NTFS_3G;
		}
	}
	if (ctx->reparse_ptr)
		ctx->reparse_ptr = mempcpy(ctx->reparse_ptr, chunk, size);
	ctx->offset += size;
	return 0;
}

static int
ntfs_3g_end_extract_blob(struct blob_descriptor *blob, int status, void *_ctx)
{
	struct ntfs_3g_apply_ctx *ctx = _ctx;
	int ret;

	if (status) {
		ret = status;
		goto out;
	}

	for (u32 i = 0; i < ctx->num_reparse_inodes; i++) {
		ret = ntfs_3g_restore_reparse_point(ctx->ntfs_reparse_inodes[i],
						    ctx->wim_reparse_inodes[i],
						    blob->size, ctx);
		if (ret)
			goto out;
	}
	ret = 0;
out:
	if (ntfs_3g_cleanup_blob_extract(ctx) && !ret) {
		ERROR_WITH_ERRNO("Error writing data to NTFS volume");
		ret = WIMLIB_ERR_NTFS_3G;
	}
	return ret;
}

static u64
ntfs_3g_count_dentries(const struct list_head *dentry_list)
{
	const struct wim_dentry *dentry;
	u64 count = 0;

	list_for_each_entry(dentry, dentry_list, d_extraction_list_node) {
		count++;
		if ((dentry->d_inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY) &&
		    dentry_has_short_name(dentry))
		{
			count++;
		}
	}

	return count;
}

static int
ntfs_3g_extract(struct list_head *dentry_list, struct apply_ctx *_ctx)
{
	struct ntfs_3g_apply_ctx *ctx = (struct ntfs_3g_apply_ctx *)_ctx;
	ntfs_volume *vol;
	struct wim_dentry *root;
	int ret;

	/* For NTFS-3g extraction mode we require that the dentries to extract
	 * form a single tree.  */
	root = list_first_entry(dentry_list, struct wim_dentry,
				d_extraction_list_node);

	/* Mount the NTFS volume.  */
	vol = ntfs_mount(ctx->common.target, 0);
	if (!vol) {
		ERROR_WITH_ERRNO("Failed to mount \"%s\" with NTFS-3g",
				 ctx->common.target);
		return WIMLIB_ERR_NTFS_3G;
	}
	ctx->vol = vol;

	/* Create all inodes and aliases, including short names, and set
	 * metadata (attributes, security descriptors, and timestamps).  */

	ret = start_file_structure_phase(&ctx->common,
					 ntfs_3g_count_dentries(dentry_list));
	if (ret)
		goto out_unmount;

	ret = ntfs_3g_create_directories(root, dentry_list, ctx);
	if (ret)
		goto out_unmount;

	ret = ntfs_3g_create_nondirectories(dentry_list, ctx);
	if (ret)
		goto out_unmount;

	ret = end_file_structure_phase(&ctx->common);
	if (ret)
		goto out_unmount;

	/* Extract blobs.  */
	struct read_blob_callbacks cbs = {
		.begin_blob	= ntfs_3g_begin_extract_blob,
		.consume_chunk	= ntfs_3g_extract_chunk,
		.end_blob	= ntfs_3g_end_extract_blob,
		.ctx		= ctx,
	};
	ret = extract_blob_list(&ctx->common, &cbs);

	/* We do not need a final pass to set timestamps because libntfs-3g does
	 * not update timestamps automatically (exception:
	 * ntfs_set_ntfs_dos_name() does, but we handle this elsewhere).  */

out_unmount:
	if (ntfs_umount(ctx->vol, FALSE) && !ret) {
		ERROR_WITH_ERRNO("Failed to unmount \"%s\" with NTFS-3g",
				 ctx->common.target);
		ret = WIMLIB_ERR_NTFS_3G;
	}
	return ret;
}

const struct apply_operations ntfs_3g_apply_ops = {
	.name			= "NTFS-3g",
	.get_supported_features = ntfs_3g_get_supported_features,
	.extract                = ntfs_3g_extract,
	.context_size           = sizeof(struct ntfs_3g_apply_ctx),
	.single_tree_only	= true,
};

void
libntfs3g_global_init(void)
{
       ntfs_set_char_encoding(setlocale(LC_ALL, ""));
}