[wimlib] / src / extract.c

/*
 * extract.c
 *
 * Support for extracting WIM images, or files or directories contained in a WIM
 * image.
 */

/*
 * Copyright (C) 2012, 2013, 2014 Eric Biggers
 *
 * This file is part of wimlib, a library for working with WIM files.
 *
 * wimlib 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.
 *
 * wimlib 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 wimlib; if not, see http://www.gnu.org/licenses/.
 */

/*
 * This file provides the API functions wimlib_extract_image(),
 * wimlib_extract_image_from_pipe(), wimlib_extract_files(),
 * wimlib_extract_paths(), and wimlib_extract_pathlist().  Internally, all end
 * up calling do_wimlib_extract_paths() and extract_trees().
 *
 * Although wimlib supports multiple extraction modes/backends (NTFS-3g, UNIX,
 * Win32), this file does not itself have code to extract files or directories
 * to any specific target; instead, it handles generic functionality and relies
 * on lower-level callback functions declared in `struct apply_operations' to do
 * the actual extraction.
 */

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

#include "wimlib/apply.h"
#include "wimlib/dentry.h"
#include "wimlib/encoding.h"
#include "wimlib/endianness.h"
#include "wimlib/error.h"
#include "wimlib/lookup_table.h"
#include "wimlib/metadata.h"
#include "wimlib/pathlist.h"
#include "wimlib/paths.h"
#include "wimlib/reparse.h"
#include "wimlib/resource.h"
#include "wimlib/security.h"
#ifdef __WIN32__
#  include "wimlib/win32.h" /* for realpath() equivalent */
#endif
#include "wimlib/xml.h"
#include "wimlib/wildcard.h"
#include "wimlib/wim.h"

#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <unistd.h>

#define WIMLIB_EXTRACT_FLAG_MULTI_IMAGE 0x80000000
#define WIMLIB_EXTRACT_FLAG_FROM_PIPE   0x40000000
#define WIMLIB_EXTRACT_FLAG_FILEMODE    0x20000000
#define WIMLIB_EXTRACT_FLAG_IMAGEMODE   0x10000000

/* Keep in sync with wimlib.h  */
#define WIMLIB_EXTRACT_MASK_PUBLIC                              \
        (WIMLIB_EXTRACT_FLAG_NTFS                       |       \
         WIMLIB_EXTRACT_FLAG_HARDLINK                   |       \
         WIMLIB_EXTRACT_FLAG_SYMLINK                    |       \
         WIMLIB_EXTRACT_FLAG_VERBOSE                    |       \
         WIMLIB_EXTRACT_FLAG_SEQUENTIAL                 |       \
         WIMLIB_EXTRACT_FLAG_UNIX_DATA                  |       \
         WIMLIB_EXTRACT_FLAG_NO_ACLS                    |       \
         WIMLIB_EXTRACT_FLAG_STRICT_ACLS                |       \
         WIMLIB_EXTRACT_FLAG_RPFIX                      |       \
         WIMLIB_EXTRACT_FLAG_NORPFIX                    |       \
         WIMLIB_EXTRACT_FLAG_TO_STDOUT                  |       \
         WIMLIB_EXTRACT_FLAG_REPLACE_INVALID_FILENAMES  |       \
         WIMLIB_EXTRACT_FLAG_ALL_CASE_CONFLICTS         |       \
         WIMLIB_EXTRACT_FLAG_STRICT_TIMESTAMPS          |       \
         WIMLIB_EXTRACT_FLAG_STRICT_SHORT_NAMES         |       \
         WIMLIB_EXTRACT_FLAG_STRICT_SYMLINKS            |       \
         WIMLIB_EXTRACT_FLAG_RESUME                     |       \
         WIMLIB_EXTRACT_FLAG_FILE_ORDER                 |       \
         WIMLIB_EXTRACT_FLAG_GLOB_PATHS                 |       \
         WIMLIB_EXTRACT_FLAG_STRICT_GLOB                |       \
         WIMLIB_EXTRACT_FLAG_NO_ATTRIBUTES              |       \
         WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE  |       \
         WIMLIB_EXTRACT_FLAG_WIMBOOT)

static bool
dentry_in_list(const struct wim_dentry *dentry)
{
        return dentry->extraction_list.next != NULL;
}

static inline bool
is_linked_extraction(const struct apply_ctx *ctx)
{
        return 0 != (ctx->extract_flags & (WIMLIB_EXTRACT_FLAG_HARDLINK |
                                           WIMLIB_EXTRACT_FLAG_SYMLINK));
}

static inline bool
can_extract_named_data_streams(const struct apply_ctx *ctx)
{
        return ctx->supported_features.named_data_streams &&
                !is_linked_extraction(ctx);
}
/* Inform library user of progress of stream extraction following the successful
 * extraction of a copy of the stream specified by @lte.  */
static void
update_extract_progress(struct apply_ctx *ctx,
                        const struct wim_lookup_table_entry *lte)
{
        wimlib_progress_func_t progress_func = ctx->progress_func;
        union wimlib_progress_info *progress = &ctx->progress;

        progress->extract.completed_bytes += lte->size;
        if (progress_func &&
            progress->extract.completed_bytes >= ctx->next_progress)
        {
                progress_func(WIMLIB_PROGRESS_MSG_EXTRACT_STREAMS, progress);
                if (progress->extract.completed_bytes >=
                    progress->extract.total_bytes)
                {
                        ctx->next_progress = ~0ULL;
                } else {
                        ctx->next_progress += progress->extract.total_bytes / 128;
                        if (ctx->next_progress > progress->extract.total_bytes)
                                ctx->next_progress = progress->extract.total_bytes;
                }
        }
}

#ifndef __WIN32__
/* Extract a symbolic link (not directly as reparse data), handling fixing up
 * the target of absolute symbolic links and updating the extract progress.
 *
 * @inode must specify the WIM inode for a symbolic link or junction reparse
 * point.
 *
 * @lte_override overrides the resource used as the reparse data for the
 * symbolic link.  */
static int
extract_symlink(const tchar *path, struct apply_ctx *ctx,
                struct wim_inode *inode,
                struct wim_lookup_table_entry *lte_override)
{
        ssize_t bufsize = ctx->ops->path_max;
        tchar target[bufsize];
        tchar *buf = target;
        tchar *fixed_target;
        ssize_t sret;
        int ret;

        /* If absolute symbolic link fixups requested, reserve space in the link
         * target buffer for the absolute path of the target directory.  */
        if (ctx->extract_flags & WIMLIB_EXTRACT_FLAG_RPFIX)
        {
                buf += ctx->realtarget_nchars;
                bufsize -= ctx->realtarget_nchars;
        }

        /* Translate the WIM inode's reparse data into the link target.  */
        sret = wim_inode_readlink(inode, buf, bufsize - 1, lte_override);
        if (sret < 0) {
                errno = -sret;
                return WIMLIB_ERR_READLINK;
        }
        buf[sret] = '\0';

        if ((ctx->extract_flags & WIMLIB_EXTRACT_FLAG_RPFIX) &&
            buf[0] == '/')
        {
                /* Fix absolute symbolic link target to point into the
                 * actual extraction destination.  */
                tmemcpy(target, ctx->realtarget, ctx->realtarget_nchars);
                fixed_target = target;
        } else {
                /* Keep same link target.  */
                fixed_target = buf;
        }

        /* Call into the apply_operations to create the symbolic link.  */
        DEBUG("Creating symlink \"%"TS"\" => \"%"TS"\"",
              path, fixed_target);
        ret = ctx->ops->create_symlink(fixed_target, path, ctx);
        if (ret) {
                ERROR_WITH_ERRNO("Failed to create symlink "
                                 "\"%"TS"\" => \"%"TS"\"", path, fixed_target);
                return ret;
        }

        /* Account for reparse data consumed.  */
        update_extract_progress(ctx,
                                (lte_override ? lte_override :
                                      inode_unnamed_lte_resolved(inode)));
        return 0;
}
#endif /* !__WIN32__ */

/* Create a file, directory, or symbolic link.  */
static int
extract_inode(const tchar *path, struct apply_ctx *ctx, struct wim_inode *inode)
{
        int ret;

#ifndef __WIN32__
        if (ctx->supported_features.symlink_reparse_points &&
            !ctx->supported_features.reparse_points &&
            inode_is_symlink(inode))
        {
                ret = extract_symlink(path, ctx, inode, NULL);
        } else
#endif /* !__WIN32__ */
        if (inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY) {
                ret = ctx->ops->create_directory(path, ctx, &inode->extract_cookie);
                if (ret) {
                        ERROR_WITH_ERRNO("Failed to create the directory "
                                         "\"%"TS"\"", path);
                }
        } else if ((inode->i_attributes & FILE_ATTRIBUTE_ENCRYPTED) &&
                    ctx->ops->extract_encrypted_stream_creates_file &&
                    ctx->supported_features.encrypted_files) {
                ret = ctx->ops->extract_encrypted_stream(
                                path, inode_unnamed_lte_resolved(inode), ctx);
                if (ret) {
                        ERROR_WITH_ERRNO("Failed to create and extract "
                                         "encrypted file \"%"TS"\"", path);
                }
        } else {
                ret = ctx->ops->create_file(path, ctx, &inode->extract_cookie);
                if (ret) {
                        ERROR_WITH_ERRNO("Failed to create the file "
                                         "\"%"TS"\"", path);
                }
        }
        return ret;
}

static int
extract_hardlink(const tchar *oldpath, const tchar *newpath,
                 struct apply_ctx *ctx)
{
        int ret;

        DEBUG("Creating hardlink \"%"TS"\" => \"%"TS"\"", newpath, oldpath);
        ret = ctx->ops->create_hardlink(oldpath, newpath, ctx);
        if (ret) {
                ERROR_WITH_ERRNO("Failed to create hardlink "
                                 "\"%"TS"\" => \"%"TS"\"",
                                 newpath, oldpath);
        }
        return ret;
}

#ifdef __WIN32__
static int
try_extract_rpfix(u8 *rpbuf,
                  u16 *rpbuflen_p,
                  const wchar_t *extract_root_realpath,
                  unsigned extract_root_realpath_nchars)
{
        struct reparse_data rpdata;
        wchar_t *target;
        size_t target_nchars;
        size_t stripped_nchars;
        wchar_t *stripped_target;
        wchar_t stripped_target_nchars;
        int ret;

        utf16lechar *new_target;
        utf16lechar *new_print_name;
        size_t new_target_nchars;
        size_t new_print_name_nchars;
        utf16lechar *p;

        ret = parse_reparse_data(rpbuf, *rpbuflen_p, &rpdata);
        if (ret)
                return ret;

        if (extract_root_realpath[0] == L'\0' ||
            extract_root_realpath[1] != L':' ||
            extract_root_realpath[2] != L'\\')
                return WIMLIB_ERR_REPARSE_POINT_FIXUP_FAILED;

        ret = parse_substitute_name(rpdata.substitute_name,
                                    rpdata.substitute_name_nbytes,
                                    rpdata.rptag);
        if (ret < 0)
                return 0;
        stripped_nchars = ret;
        target = rpdata.substitute_name;
        target_nchars = rpdata.substitute_name_nbytes / sizeof(utf16lechar);
        stripped_target = target + stripped_nchars;
        stripped_target_nchars = target_nchars - stripped_nchars;

        new_target = alloca((6 + extract_root_realpath_nchars +
                             stripped_target_nchars) * sizeof(utf16lechar));

        p = new_target;
        if (stripped_nchars == 6) {
                /* Include \??\ prefix if it was present before */
                p = wmempcpy(p, L"\\??\\", 4);
        }

        /* Print name excludes the \??\ if present. */
        new_print_name = p;
        if (stripped_nchars != 0) {
                /* Get drive letter from real path to extract root, if a drive
                 * letter was present before. */
                *p++ = extract_root_realpath[0];
                *p++ = extract_root_realpath[1];
        }
        /* Copy the rest of the extract root */
        p = wmempcpy(p, extract_root_realpath + 2, extract_root_realpath_nchars - 2);

        /* Append the stripped target */
        p = wmempcpy(p, stripped_target, stripped_target_nchars);
        new_target_nchars = p - new_target;
        new_print_name_nchars = p - new_print_name;

        if (new_target_nchars * sizeof(utf16lechar) >= REPARSE_POINT_MAX_SIZE ||
            new_print_name_nchars * sizeof(utf16lechar) >= REPARSE_POINT_MAX_SIZE)
                return WIMLIB_ERR_REPARSE_POINT_FIXUP_FAILED;

        rpdata.substitute_name = new_target;
        rpdata.substitute_name_nbytes = new_target_nchars * sizeof(utf16lechar);
        rpdata.print_name = new_print_name;
        rpdata.print_name_nbytes = new_print_name_nchars * sizeof(utf16lechar);
        return make_reparse_buffer(&rpdata, rpbuf, rpbuflen_p);
}
#endif /* __WIN32__ */

/* Set reparse data on extracted file or directory that has
 * FILE_ATTRIBUTE_REPARSE_POINT set.  */
static int
extract_reparse_data(const tchar *path, struct apply_ctx *ctx,
                     struct wim_inode *inode,
                     struct wim_lookup_table_entry *lte_override)
{
        int ret;
        u8 rpbuf[REPARSE_POINT_MAX_SIZE];
        u16 rpbuflen;

        ret = wim_inode_get_reparse_data(inode, rpbuf, &rpbuflen, lte_override);
        if (ret)
                goto error;

#ifdef __WIN32__
        /* Fix up target of absolute symbolic link or junction points so
         * that they point into the actual extraction target.  */
        if ((ctx->extract_flags & WIMLIB_EXTRACT_FLAG_RPFIX) &&
            (inode->i_reparse_tag == WIM_IO_REPARSE_TAG_SYMLINK ||
             inode->i_reparse_tag == WIM_IO_REPARSE_TAG_MOUNT_POINT) &&
            !inode->i_not_rpfixed)
        {
                ret = try_extract_rpfix(rpbuf, &rpbuflen, ctx->realtarget,
                                        ctx->realtarget_nchars);
                if (ret && !(ctx->extract_flags &
                             WIMLIB_EXTRACT_FLAG_STRICT_SYMLINKS))
                {
                        WARNING("Reparse point fixup of \"%"TS"\" "
                                "failed", path);
                        ret = 0;
                }
                if (ret)
                        goto error;
        }
#endif

        ret = ctx->ops->set_reparse_data(path, rpbuf, rpbuflen, ctx);

        /* On Windows, the SeCreateSymbolicLink privilege is required to create
         * symbolic links.  To be more friendly towards non-Administrator users,
         * we merely warn the user if symbolic links cannot be created due to
         * insufficient permissions or privileges, unless
         * WIMLIB_EXTRACT_FLAG_STRICT_SYMLINKS was provided.  */
#ifdef __WIN32__
        if (ret && inode_is_symlink(inode) &&
            (errno == EACCES || errno == EPERM) &&
            !(ctx->extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_SYMLINKS))
        {
                WARNING("Can't set reparse data on \"%"TS"\": "
                        "Access denied!\n"
                        "          You may be trying to "
                        "extract a symbolic link without the\n"
                        "          SeCreateSymbolicLink privilege, "
                        "which by default non-Administrator\n"
                        "          accounts do not have.",
                        path);
                ret = 0;
        }
#endif
        if (ret)
                goto error;

        /* Account for reparse data consumed.  */
        update_extract_progress(ctx,
                                (lte_override ? lte_override :
                                      inode_unnamed_lte_resolved(inode)));
        return 0;

error:
        ERROR_WITH_ERRNO("Failed to set reparse data on \"%"TS"\"", path);
        return ret;
}

/*
 * Extract zero or more streams to a file.
 *
 * This function operates slightly differently depending on whether @lte_spec is
 * NULL or not.  When @lte_spec is NULL, the behavior is to extract the default
 * file contents (unnamed stream), and, if named data streams are supported in
 * the extract mode and volume, any named data streams.  When @lte_spec is not
 * NULL, the behavior is to extract only all copies of the stream @lte_spec, and
 * in addition use @lte_spec to set the reparse data or create the symbolic link
 * if appropriate.
 *
 * @path
 *      Path to file to extract (as can be passed to apply_operations
 *      functions).
 * @ctx
 *      Apply context.
 * @dentry
 *      WIM dentry that corresponds to the file being extracted.
 * @lte_spec
 *      If non-NULL, specifies the lookup table entry for a stream to extract,
 *      and only that stream will be extracted (although there may be more than
 *      one instance of it).
 * @lte_override
 *      Used only if @lte_spec != NULL; it is passed to the extraction functions
 *      rather than @lte_spec, allowing the location of the stream to be
 *      overridden.  (This is used when the WIM is being read from a nonseekable
 *      file, such as a pipe, when streams need to be used more than once; each
 *      such stream is extracted to a temporary file.)
 */
static int
extract_streams(const tchar *path, struct apply_ctx *ctx,
                struct wim_dentry *dentry,
                struct wim_lookup_table_entry *lte_spec,
                struct wim_lookup_table_entry *lte_override)
{
        struct wim_inode *inode = dentry->d_inode;
        struct wim_lookup_table_entry *lte;
        file_spec_t file_spec;
        int ret;

        if (dentry->was_linked)
                return 0;

#ifdef ENABLE_DEBUG
        if (lte_spec) {
                char sha1_str[100];
                char *p = sha1_str;
                for (unsigned i = 0; i < SHA1_HASH_SIZE; i++)
                        p += sprintf(p, "%02x", lte_override->hash[i]);
                DEBUG("Extracting stream SHA1=%s to \"%"TS"\"",
                      sha1_str, path, inode->i_ino);
        } else {
                DEBUG("Extracting streams to \"%"TS"\"", path, inode->i_ino);
        }
#endif

        if (ctx->ops->uses_cookies)
                file_spec.cookie = inode->extract_cookie;
        else
                file_spec.path = path;

        /* Unnamed data stream.  */
        lte = inode_unnamed_lte_resolved(inode);
        if (lte && (!lte_spec || lte == lte_spec)) {
                if (lte_spec)
                        lte = lte_override;
                if (!(inode->i_attributes & (FILE_ATTRIBUTE_DIRECTORY |
                                             FILE_ATTRIBUTE_REPARSE_POINT)))
                {
                        if (inode->i_attributes & FILE_ATTRIBUTE_ENCRYPTED &&
                            ctx->supported_features.encrypted_files) {
                                if (!ctx->ops->extract_encrypted_stream_creates_file) {
                                        ret = ctx->ops->extract_encrypted_stream(
                                                                path, lte, ctx);
                                        if (ret)
                                                goto error;
                                }
                        } else {
                                ret = ctx->ops->extract_unnamed_stream(
                                                        file_spec, lte, ctx);
                                if (ret)
                                        goto error;
                        }
                        update_extract_progress(ctx, lte);
                }
                else if (inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT)
                {
                        ret = 0;
                        if (ctx->supported_features.reparse_points)
                                ret = extract_reparse_data(path, ctx, inode, lte);
                #ifndef __WIN32__
                        else if ((inode_is_symlink(inode) &&
                                  ctx->supported_features.symlink_reparse_points))
                                ret = extract_symlink(path, ctx, inode, lte);
                #endif
                        if (ret)
                                return ret;
                }
        }

        /* Named data streams.  */
        if (can_extract_named_data_streams(ctx)) {
                for (u16 i = 0; i < inode->i_num_ads; i++) {
                        struct wim_ads_entry *entry = &inode->i_ads_entries[i];

                        if (!ads_entry_is_named_stream(entry))
                                continue;
                        lte = entry->lte;
                        if (!lte)
                                continue;
                        if (lte_spec && lte_spec != lte)
                                continue;
                        if (lte_spec)
                                lte = lte_override;
                        ret = ctx->ops->extract_named_stream(file_spec, entry->stream_name,
                                                             entry->stream_name_nbytes / 2,
                                                             lte, ctx);
                        if (ret)
                                goto error;
                        update_extract_progress(ctx, lte);
                }
        }
        return 0;

error:
        ERROR_WITH_ERRNO("Failed to extract data of \"%"TS"\"", path);
        return ret;
}

/* Set attributes on an extracted file or directory if supported by the
 * extraction mode.  */
static int
extract_file_attributes(const tchar *path, struct apply_ctx *ctx,
                        struct wim_dentry *dentry, unsigned pass)
{
        int ret;

        if (ctx->ops->set_file_attributes &&
            !(ctx->extract_flags & WIMLIB_EXTRACT_FLAG_NO_ATTRIBUTES) &&
            !(dentry == ctx->target_dentry && ctx->root_dentry_is_special)) {
                u32 attributes = dentry->d_inode->i_attributes;

                /* Clear unsupported attributes.  */
                attributes &= ctx->supported_attributes_mask;

                if ((attributes & FILE_ATTRIBUTE_DIRECTORY &&
                     !ctx->supported_features.encrypted_directories) ||
                    (!(attributes & FILE_ATTRIBUTE_DIRECTORY) &&
                     !ctx->supported_features.encrypted_files))
                {
                        attributes &= ~FILE_ATTRIBUTE_ENCRYPTED;
                }

                if (attributes == 0)
                        attributes = FILE_ATTRIBUTE_NORMAL;

                ret = ctx->ops->set_file_attributes(path, attributes, ctx, pass);
                if (ret) {
                        ERROR_WITH_ERRNO("Failed to set attributes on "
                                         "\"%"TS"\"", path);
                        return ret;
                }
        }
        return 0;
}


/* Set or remove the short (DOS) name on an extracted file or directory if
 * supported by the extraction mode.  Since DOS names are unimportant and it's
 * easy to run into problems setting them on Windows (SetFileShortName()
 * requires SE_RESTORE privilege, which only the Administrator can request, and
 * also requires DELETE access to the file), failure is ignored unless
 * WIMLIB_EXTRACT_FLAG_STRICT_SHORT_NAMES is set.  */
static int
extract_short_name(const tchar *path, struct apply_ctx *ctx,
                   struct wim_dentry *dentry)
{
        int ret;

        /* The root of the dentry tree being extracted may not be extracted to
         * its original name, so its short name should be ignored.  */
        if (dentry == ctx->target_dentry)
                return 0;

        if (ctx->supported_features.short_names) {
                ret = ctx->ops->set_short_name(path,
                                               dentry->short_name,
                                               dentry->short_name_nbytes / 2,
                                               ctx);
                if (ret && (ctx->extract_flags &
                            WIMLIB_EXTRACT_FLAG_STRICT_SHORT_NAMES))
                {
                        ERROR_WITH_ERRNO("Failed to set short name of "
                                         "\"%"TS"\"", path);
                        return ret;
                }
        }
        return 0;
}

/* Set security descriptor, UNIX data, or neither on an extracted file, taking
 * into account the current extraction mode and flags.  */
static int
extract_security(const tchar *path, struct apply_ctx *ctx,
                 struct wim_dentry *dentry)
{
        int ret;
        struct wim_inode *inode = dentry->d_inode;

        if (ctx->extract_flags & WIMLIB_EXTRACT_FLAG_NO_ACLS)
                return 0;

        if ((ctx->target_dentry == dentry) && ctx->root_dentry_is_special)
                return 0;

#ifndef __WIN32__
        if (ctx->extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA) {
                struct wimlib_unix_data data;

                ret = inode_get_unix_data(inode, &data, NULL);
                if (ret < 0)
                        ret = 0;
                else if (ret == 0)
                        ret = ctx->ops->set_unix_data(path, &data, ctx);
                if (ret) {
                        if (ctx->extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_ACLS) {
                                ERROR_WITH_ERRNO("Failed to set UNIX owner, "
                                                 "group, and/or mode on "
                                                 "\"%"TS"\"", path);
                                return ret;
                        } else {
                                WARNING_WITH_ERRNO("Failed to set UNIX owner, "
                                                   "group, and/or/mode on "
                                                   "\"%"TS"\"", path);
                        }
                }
        }
        else
#endif /* __WIN32__ */
        if (ctx->supported_features.security_descriptors &&
            inode->i_security_id != -1)
        {
                const struct wim_security_data *sd;
                const u8 *desc;
                size_t desc_size;

                sd = wim_const_security_data(ctx->wim);
                desc = sd->descriptors[inode->i_security_id];
                desc_size = sd->sizes[inode->i_security_id];

                ret = ctx->ops->set_security_descriptor(path, desc,
                                                        desc_size, ctx);
                if (ret) {
                        if (ctx->extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_ACLS) {
                                ERROR_WITH_ERRNO("Failed to set security "
                                                 "descriptor on \"%"TS"\"", path);
                                return ret;
                        } else {
                        #if 0
                                if (errno != EACCES) {
                                        WARNING_WITH_ERRNO("Failed to set "
                                                           "security descriptor "
                                                           "on \"%"TS"\"", path);
                                }
                        #endif
                                ctx->no_security_descriptors++;
                        }
                }
        }
        return 0;
}

/* Set timestamps on an extracted file.  Failure is warning-only unless
 * WIMLIB_EXTRACT_FLAG_STRICT_TIMESTAMPS is set.  */
static int
extract_timestamps(const tchar *path, struct apply_ctx *ctx,
                   struct wim_dentry *dentry)
{
        struct wim_inode *inode = dentry->d_inode;
        int ret;

        if ((ctx->target_dentry == dentry) && ctx->root_dentry_is_special)
                return 0;

        if (ctx->ops->set_timestamps) {
                ret = ctx->ops->set_timestamps(path,
                                               inode->i_creation_time,
                                               inode->i_last_write_time,
                                               inode->i_last_access_time,
                                               ctx);
                if (ret) {
                        if (ctx->extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_TIMESTAMPS) {
                                ERROR_WITH_ERRNO("Failed to set timestamps "
                                                 "on \"%"TS"\"", path);
                                return ret;
                        } else {
                                WARNING_WITH_ERRNO("Failed to set timestamps "
                                                   "on \"%"TS"\"", path);
                        }
                }
        }
        return 0;
}

/* Check whether the extraction of a dentry should be skipped completely.  */
static bool
dentry_is_supported(struct wim_dentry *dentry,
                    const struct wim_features *supported_features)
{
        struct wim_inode *inode = dentry->d_inode;

        if (inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
                return supported_features->reparse_points ||
                        (inode_is_symlink(inode) &&
                         supported_features->symlink_reparse_points);
        }
        if (inode->i_attributes & FILE_ATTRIBUTE_ENCRYPTED) {
                if (inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY)
                        return supported_features->encrypted_directories != 0;
                else
                        return supported_features->encrypted_files != 0;
        }
        return true;
}

/* Given a WIM dentry to extract, build the path to which to extract it, in the
 * format understood by the callbacks in the apply_operations being used.
 *
 * Write the resulting path into @path, which must have room for at least
 * ctx->ops->path_max characters.
 *
 * Return %true if successful; %false if this WIM dentry doesn't actually need
 * to be extracted or if the calculated path exceeds ctx->ops->max_path
 * characters.
 *
 * This function clobbers the tmp_list member of @dentry and its ancestors up
 * until the extraction root.  */
static bool
build_extraction_path(tchar path[], struct wim_dentry *dentry,
                      const struct apply_ctx *ctx)
{
        size_t path_nchars;
        LIST_HEAD(ancestor_list);
        tchar *p = path;
        const tchar *target_prefix;
        size_t target_prefix_nchars;
        struct wim_dentry *d;

        path_nchars = ctx->ops->path_prefix_nchars;

        if (ctx->ops->requires_realtarget_in_paths) {
                target_prefix        = ctx->realtarget;
                target_prefix_nchars = ctx->realtarget_nchars;
        } else if (ctx->ops->requires_target_in_paths) {
                target_prefix        = ctx->target;
                target_prefix_nchars = ctx->target_nchars;
        } else {
                target_prefix        = NULL;
                target_prefix_nchars = 0;
        }
        path_nchars += target_prefix_nchars;

        for (d = dentry; d != ctx->target_dentry; d = d->parent) {
                if (!dentry_in_list(d))
                        break;

                path_nchars += d->extraction_name_nchars + 1;
                list_add(&d->tmp_list, &ancestor_list);
        }

        path_nchars++; /* null terminator */

        if (path_nchars > ctx->ops->path_max) {
                WARNING("\"%"TS"\": Path too long to extract",
                        dentry_full_path(dentry));
                return false;
        }

        p = tmempcpy(p, ctx->ops->path_prefix, ctx->ops->path_prefix_nchars);
        p = tmempcpy(p, target_prefix, target_prefix_nchars);
        list_for_each_entry(d, &ancestor_list, tmp_list) {
                *p++ = ctx->ops->path_separator;
                p = tmempcpy(p, d->extraction_name, d->extraction_name_nchars);
        }
        *p++ = T('\0');
        wimlib_assert(p - path == path_nchars);
        return true;
}

static unsigned
get_num_path_components(const tchar *path, tchar path_separator)
{
        unsigned num_components = 0;
#ifdef __WIN32__
        /* Ignore drive letter.  */
        if (path[0] != L'\0' && path[1] == L':')
                path += 2;
#endif

        while (*path) {
                while (*path == path_separator)
                        path++;
                if (*path)
                        num_components++;
                while (*path && *path != path_separator)
                        path++;
        }
        return num_components;
}

static int
extract_multiimage_symlink(const tchar *oldpath, const tchar *newpath,
                           struct apply_ctx *ctx, struct wim_dentry *dentry)
{
        size_t num_raw_path_components;
        const struct wim_dentry *d;
        size_t num_target_path_components;
        tchar *p;
        const tchar *p_old;
        int ret;

        num_raw_path_components = 0;
        for (d = dentry; d != ctx->target_dentry; d = d->parent)
                num_raw_path_components++;

        if (ctx->ops->requires_realtarget_in_paths)
                num_target_path_components = get_num_path_components(ctx->realtarget,
                                                                     ctx->ops->path_separator);
        else if (ctx->ops->requires_target_in_paths)
                num_target_path_components = get_num_path_components(ctx->target,
                                                                     ctx->ops->path_separator);
        else
                num_target_path_components = 0;

        if (ctx->extract_flags & WIMLIB_EXTRACT_FLAG_MULTI_IMAGE) {
                wimlib_assert(num_target_path_components > 0);
                num_raw_path_components++;
                num_target_path_components--;
        }

        p_old = oldpath + ctx->ops->path_prefix_nchars;
#ifdef __WIN32__
        if (p_old[0] != L'\0' && p_old[1] == ':')
                p_old += 2;
#endif
        while (*p_old == ctx->ops->path_separator)
                p_old++;
        while (--num_target_path_components) {
                while (*p_old != ctx->ops->path_separator)
                        p_old++;
                while (*p_old == ctx->ops->path_separator)
                        p_old++;
        }

        tchar symlink_target[tstrlen(p_old) + 3 * num_raw_path_components + 1];

        p = &symlink_target[0];
        while (num_raw_path_components--) {
                *p++ = '.';
                *p++ = '.';
                *p++ = ctx->ops->path_separator;
        }
        tstrcpy(p, p_old);
        DEBUG("Creating symlink \"%"TS"\" => \"%"TS"\"",
              newpath, symlink_target);
        ret = ctx->ops->create_symlink(symlink_target, newpath, ctx);
        if (ret) {
                ERROR_WITH_ERRNO("Failed to create symlink "
                                 "\"%"TS"\" => \"%"TS"\"",
                                 newpath, symlink_target);
        }
        return ret;
}

/* Create the "skeleton" of an extracted file or directory.  Don't yet extract
 * data streams, reparse data (including symbolic links), timestamps, and
 * security descriptors.  Basically, everything that doesn't require reading
 * non-metadata resources from the WIM file and isn't delayed until the final
 * pass.  */
static int
do_dentry_extract_skeleton(tchar path[], struct wim_dentry *dentry,
                           struct apply_ctx *ctx)
{
        struct wim_inode *inode = dentry->d_inode;
        int ret;
        const tchar *oldpath;

        if (unlikely(is_linked_extraction(ctx))) {
                struct wim_lookup_table_entry *unnamed_lte;

                unnamed_lte = inode_unnamed_lte_resolved(dentry->d_inode);
                if (unnamed_lte && unnamed_lte->extracted_file) {
                        oldpath = unnamed_lte->extracted_file;
                        if (ctx->extract_flags & WIMLIB_EXTRACT_FLAG_HARDLINK)
                                goto hardlink;
                        else
                                goto symlink;
                }
        }

        /* Create hard link if this dentry corresponds to an already-extracted
         * inode.  */
        if (inode->i_extracted_file) {
                oldpath = inode->i_extracted_file;
                goto hardlink;
        }

        /* Skip symlinks unless they can be extracted as reparse points rather
         * than created directly.  */
        if (inode_is_symlink(inode) && !ctx->supported_features.reparse_points)
                return 0;

        /* Create this file or directory unless it's the extraction root, which
         * was already created if necessary.  */
        if (dentry != ctx->target_dentry) {
                ret = extract_inode(path, ctx, inode);
                if (ret)
                        return ret;
        }

        /* Create empty named data streams.  */
        if (can_extract_named_data_streams(ctx)) {
                for (u16 i = 0; i < inode->i_num_ads; i++) {
                        file_spec_t file_spec;
                        struct wim_ads_entry *entry = &inode->i_ads_entries[i];

                        if (!ads_entry_is_named_stream(entry))
                                continue;
                        if (entry->lte)
                                continue;
                        if (ctx->ops->uses_cookies)
                                file_spec.cookie = inode->extract_cookie;
                        else
                                file_spec.path = path;
                        ret = ctx->ops->extract_named_stream(file_spec,
                                                             entry->stream_name,
                                                             entry->stream_name_nbytes / 2,
                                                             entry->lte, ctx);
                        if (ret) {
                                ERROR_WITH_ERRNO("\"%"TS"\": failed to create "
                                                 "empty named data stream",
                                                 path);
                                return ret;
                        }
                }
        }

        /* Set file attributes (if supported).  */
        ret = extract_file_attributes(path, ctx, dentry, 0);
        if (ret)
                return ret;

        /* Set or remove file short name (if supported).  */
        ret = extract_short_name(path, ctx, dentry);
        if (ret)
                return ret;

        /* If inode has multiple links and hard links are supported in this
         * extraction mode and volume, save the path to the extracted file in
         * case it's needed to create a hard link.  */
        if (unlikely(is_linked_extraction(ctx))) {
                struct wim_lookup_table_entry *unnamed_lte;

                unnamed_lte = inode_unnamed_lte_resolved(dentry->d_inode);
                if (unnamed_lte) {
                        unnamed_lte->extracted_file = TSTRDUP(path);
                        if (!unnamed_lte->extracted_file)
                                return WIMLIB_ERR_NOMEM;
                }
        } else if (inode->i_nlink > 1 && ctx->supported_features.hard_links) {
                inode->i_extracted_file = TSTRDUP(path);
                if (!inode->i_extracted_file)
                        return WIMLIB_ERR_NOMEM;
        }
        return 0;

symlink:
        ret = extract_multiimage_symlink(oldpath, path, ctx, dentry);
        if (ret)
                return ret;
        dentry->was_linked = 1;
        return 0;

hardlink:
        ret = extract_hardlink(oldpath, path, ctx);
        if (ret)
                return ret;
        dentry->was_linked = 1;
        return 0;
}

/* This is a wrapper around do_dentry_extract_skeleton() that handles building
 * the path, doing short name reordering.  This is also idempotent; dentries
 * already processed have skeleton_extracted set and no action is taken.  See
 * apply_operations.requires_short_name_reordering for more details about short
 * name reordering.  */
static int
dentry_extract_skeleton(struct wim_dentry *dentry, struct apply_ctx *ctx)
{
        tchar path[ctx->ops->path_max];
        struct wim_dentry *orig_dentry;
        struct wim_dentry *other_dentry;
        int ret;

        if (dentry->skeleton_extracted)
                return 0;

        orig_dentry = NULL;
        if (ctx->supported_features.short_names
            && ctx->ops->requires_short_name_reordering
            && !dentry_has_short_name(dentry)
            && !dentry->d_inode->i_dos_name_extracted)
        {
                inode_for_each_dentry(other_dentry, dentry->d_inode) {
                        if (dentry_has_short_name(other_dentry)
                            && !other_dentry->skeleton_extracted
                            && dentry_in_list(other_dentry))
                        {
                                DEBUG("Creating %"TS" before %"TS" "
                                      "to guarantee correct DOS name extraction",
                                      dentry_full_path(other_dentry),
                                      dentry_full_path(dentry));
                                orig_dentry = dentry;
                                dentry = other_dentry;
                                break;
                        }
                }
        }
again:
        if (!build_extraction_path(path, dentry, ctx))
                return 0;
        ret = do_dentry_extract_skeleton(path, dentry, ctx);
        if (ret)
                return ret;

        dentry->skeleton_extracted = 1;

        if (orig_dentry) {
                dentry = orig_dentry;
                orig_dentry = NULL;
                goto again;
        }
        dentry->d_inode->i_dos_name_extracted = 1;
        return 0;
}

/* Create a file or directory, then immediately extract all streams.  The WIM
 * may not be read sequentially by this function.  */
static int
dentry_extract(struct wim_dentry *dentry, struct apply_ctx *ctx)
{
        tchar path[ctx->ops->path_max];
        int ret;

        ret = dentry_extract_skeleton(dentry, ctx);
        if (ret)
                return ret;

        if (!build_extraction_path(path, dentry, ctx))
                return 0;

        return extract_streams(path, ctx, dentry, NULL, NULL);
}

/* Finish extracting a file, directory, or symbolic link by setting file
 * security and timestamps.  */
static int
dentry_extract_final(struct wim_dentry *dentry, struct apply_ctx *ctx)
{
        int ret;
        tchar path[ctx->ops->path_max];

        if (!build_extraction_path(path, dentry, ctx))
                return 0;

        ret = extract_security(path, ctx, dentry);
        if (ret)
                return ret;

        if (ctx->ops->requires_final_set_attributes_pass) {
                /* Set file attributes (if supported).  */
                ret = extract_file_attributes(path, ctx, dentry, 1);
                if (ret)
                        return ret;
        }

        return extract_timestamps(path, ctx, dentry);
}

static int
extract_structure(struct list_head *dentry_list, struct apply_ctx *ctx)
{
        struct wim_dentry *dentry;
        int ret;

        list_for_each_entry(dentry, dentry_list, extraction_list) {
                ret = dentry_extract_skeleton(dentry, ctx);
                if (ret)
                        return ret;
        }
        return 0;
}

static int
extract_dir_structure(struct list_head *dentry_list, struct apply_ctx *ctx)
{
        struct wim_dentry *dentry;
        int ret;

        list_for_each_entry(dentry, dentry_list, extraction_list) {
                if (dentry_is_directory(dentry)) {
                        ret = dentry_extract_skeleton(dentry, ctx);
                        if (ret)
                                return ret;
                }
        }
        return 0;
}

static int
extract_dentries(struct list_head *dentry_list, struct apply_ctx *ctx)
{
        struct wim_dentry *dentry;
        int ret;

        list_for_each_entry(dentry, dentry_list, extraction_list) {
                ret = dentry_extract(dentry, ctx);
                if (ret)
                        return ret;
        }
        return 0;
}

static int
extract_final_metadata(struct list_head *dentry_list, struct apply_ctx *ctx)
{
        struct wim_dentry *dentry;
        int ret;

        list_for_each_entry_reverse(dentry, dentry_list, extraction_list) {
                ret = dentry_extract_final(dentry, ctx);
                if (ret)
                        return ret;
        }
        return 0;
}

/* Creates a temporary file opened for writing.  The open file descriptor is
 * returned in @fd_ret and its name is returned in @name_ret (dynamically
 * allocated).  */
static int
create_temporary_file(struct filedes *fd_ret, tchar **name_ret)
{
        tchar *name;
        int raw_fd;

retry:
        name = ttempnam(NULL, T("wimlib"));
        if (name == NULL) {
                ERROR_WITH_ERRNO("Failed to create temporary filename");
                return WIMLIB_ERR_NOMEM;
        }

        raw_fd = topen(name, O_WRONLY | O_CREAT | O_EXCL | O_BINARY, 0600);

        if (raw_fd < 0) {
                if (errno == EEXIST) {
                        FREE(name);
                        goto retry;
                }
                ERROR_WITH_ERRNO("Failed to open temporary file \"%"TS"\"", name);
                FREE(name);
                return WIMLIB_ERR_OPEN;
        }

        filedes_init(fd_ret, raw_fd);
        *name_ret = name;
        return 0;
}

/* Extract all instances of the stream @lte that are being extracted in this
 * call of extract_tree(), but actually read the stream data from @lte_override.
 */
static int
extract_stream_instances(struct wim_lookup_table_entry *lte,
                         struct wim_lookup_table_entry *lte_override,
                         struct apply_ctx *ctx)
{
        struct wim_dentry **lte_dentries;
        tchar path[ctx->ops->path_max];
        size_t i;
        int ret;

        if (lte->out_refcnt <= ARRAY_LEN(lte->inline_lte_dentries))
                lte_dentries = lte->inline_lte_dentries;
        else
                lte_dentries = lte->lte_dentries;

        for (i = 0; i < lte->out_refcnt; i++) {
                struct wim_dentry *dentry = lte_dentries[i];

                if (dentry->tmp_flag)
                        continue;
                if (!build_extraction_path(path, dentry, ctx))
                        continue;
                ret = extract_streams(path, ctx, dentry, lte, lte_override);
                if (ret)
                        goto out_clear_tmp_flags;
                dentry->tmp_flag = 1;
        }
        ret = 0;
out_clear_tmp_flags:
        for (i = 0; i < lte->out_refcnt; i++)
                lte_dentries[i]->tmp_flag = 0;
        return ret;
}

/* Determine whether the specified stream needs to be extracted to a temporary
 * file or not.
 *
 * @lte->out_refcnt specifies the number of instances of this stream that must
 * be extracted.
 *
 * @is_partial_res is %true if this stream is just one of multiple in a single
 * WIM resource being extracted.  */
static bool
need_tmpfile_to_extract(struct wim_lookup_table_entry *lte,
                        bool is_partial_res)
{
        /* Temporary file is always required when reading a partial resource,
         * since in that case we retrieve all the contained streams in one pass.
         * */
        if (is_partial_res)
                return true;

        /* Otherwise we don't need a temporary file if only a single instance of
         * the stream is needed.  */
        if (lte->out_refcnt == 1)
                return false;

        wimlib_assert(lte->out_refcnt >= 2);

        /* We also don't need a temporary file if random access to the stream is
         * allowed.  */
        if (lte->resource_location != RESOURCE_IN_WIM ||
            filedes_is_seekable(&lte->rspec->wim->in_fd))
                return false;

        return true;
}

static int
begin_extract_stream_to_tmpfile(struct wim_lookup_table_entry *lte,
                                bool is_partial_res,
                                void *_ctx)
{
        struct apply_ctx *ctx = _ctx;
        int ret;

        if (!need_tmpfile_to_extract(lte, is_partial_res)) {
                DEBUG("Temporary file not needed "
                      "for stream (size=%"PRIu64")", lte->size);
                ret = extract_stream_instances(lte, lte, ctx);
                if (ret)
                        return ret;

                return BEGIN_STREAM_STATUS_SKIP_STREAM;
        }

        DEBUG("Temporary file needed for stream (size=%"PRIu64")", lte->size);
        return create_temporary_file(&ctx->tmpfile_fd, &ctx->tmpfile_name);
}

static int
end_extract_stream_to_tmpfile(struct wim_lookup_table_entry *lte,
                              int status, void *_ctx)
{
        struct apply_ctx *ctx = _ctx;
        struct wim_lookup_table_entry lte_override;
        int ret;
        int errno_save = errno;

        ret = filedes_close(&ctx->tmpfile_fd);

        if (status) {
                ret = status;
                errno = errno_save;
                goto out_delete_tmpfile;
        }

        if (ret) {
                ERROR_WITH_ERRNO("Error writing temporary file %"TS, ctx->tmpfile_name);
                ret = WIMLIB_ERR_WRITE;
                goto out_delete_tmpfile;
        }

        /* Now that a full stream has been extracted to a temporary file,
         * extract all instances of it to the actual target.  */

        memcpy(&lte_override, lte, sizeof(struct wim_lookup_table_entry));
        lte_override.resource_location = RESOURCE_IN_FILE_ON_DISK;
        lte_override.file_on_disk = ctx->tmpfile_name;

        ret = extract_stream_instances(lte, &lte_override, ctx);

out_delete_tmpfile:
        errno_save = errno;
        tunlink(ctx->tmpfile_name);
        FREE(ctx->tmpfile_name);
        errno = errno_save;
        return ret;
}

/* Extracts a list of streams (ctx.stream_list), assuming that the directory
 * structure and empty files were already created.  This relies on the
 * per-`struct wim_lookup_table_entry' list of dentries that reference each
 * stream that was constructed earlier.  */
static int
extract_stream_list(struct apply_ctx *ctx)
{
        struct read_stream_list_callbacks cbs = {
                .begin_stream           = begin_extract_stream_to_tmpfile,
                .begin_stream_ctx       = ctx,
                .consume_chunk          = extract_chunk_to_fd,
                .consume_chunk_ctx      = &ctx->tmpfile_fd,
                .end_stream             = end_extract_stream_to_tmpfile,
                .end_stream_ctx         = ctx,
        };
        return read_stream_list(&ctx->stream_list,
                                offsetof(struct wim_lookup_table_entry, extraction_list),
                                &cbs, VERIFY_STREAM_HASHES);
}

#define PWM_ALLOW_WIM_HDR 0x00001
#define PWM_SILENT_EOF    0x00002

/* Read the header from a stream in a pipable WIM.  */
static int
read_pwm_stream_header(WIMStruct *pwm, struct wim_lookup_table_entry *lte,
                       struct wim_resource_spec *rspec,
                       int flags, struct wim_header_disk *hdr_ret)
{
        union {
                struct pwm_stream_hdr stream_hdr;
                struct wim_header_disk pwm_hdr;
        } buf;
        struct wim_reshdr reshdr;
        int ret;

        ret = full_read(&pwm->in_fd, &buf.stream_hdr, sizeof(buf.stream_hdr));
        if (ret)
                goto read_error;

        if ((flags & PWM_ALLOW_WIM_HDR) && buf.stream_hdr.magic == PWM_MAGIC) {
                BUILD_BUG_ON(sizeof(buf.pwm_hdr) < sizeof(buf.stream_hdr));
                ret = full_read(&pwm->in_fd, &buf.stream_hdr + 1,
                                sizeof(buf.pwm_hdr) - sizeof(buf.stream_hdr));

                if (ret)
                        goto read_error;
                lte->resource_location = RESOURCE_NONEXISTENT;
                memcpy(hdr_ret, &buf.pwm_hdr, sizeof(buf.pwm_hdr));
                return 0;
        }

        if (le64_to_cpu(buf.stream_hdr.magic) != PWM_STREAM_MAGIC) {
                ERROR("Data read on pipe is invalid (expected stream header).");
                return WIMLIB_ERR_INVALID_PIPABLE_WIM;
        }

        copy_hash(lte->hash, buf.stream_hdr.hash);

        reshdr.size_in_wim = 0;
        reshdr.flags = le32_to_cpu(buf.stream_hdr.flags);
        reshdr.offset_in_wim = pwm->in_fd.offset;
        reshdr.uncompressed_size = le64_to_cpu(buf.stream_hdr.uncompressed_size);
        wim_res_hdr_to_spec(&reshdr, pwm, rspec);
        lte_bind_wim_resource_spec(lte, rspec);
        lte->flags = rspec->flags;
        lte->size = rspec->uncompressed_size;
        lte->offset_in_res = 0;
        return 0;

read_error:
        if (ret != WIMLIB_ERR_UNEXPECTED_END_OF_FILE || !(flags & PWM_SILENT_EOF))
                ERROR_WITH_ERRNO("Error reading pipable WIM from pipe");
        return ret;
}

static int
extract_streams_from_pipe(struct apply_ctx *ctx)
{
        struct wim_lookup_table_entry *found_lte;
        struct wim_resource_spec *rspec;
        struct wim_lookup_table_entry *needed_lte;
        struct wim_lookup_table *lookup_table;
        struct wim_header_disk pwm_hdr;
        int ret;
        int pwm_flags;

        ret = WIMLIB_ERR_NOMEM;
        found_lte = new_lookup_table_entry();
        if (found_lte == NULL)
                goto out;

        rspec = MALLOC(sizeof(struct wim_resource_spec));
        if (rspec == NULL)
                goto out_free_found_lte;

        lookup_table = ctx->wim->lookup_table;
        pwm_flags = PWM_ALLOW_WIM_HDR;
        if ((ctx->extract_flags & WIMLIB_EXTRACT_FLAG_RESUME))
                pwm_flags |= PWM_SILENT_EOF;
        memcpy(ctx->progress.extract.guid, ctx->wim->hdr.guid, WIM_GID_LEN);
        ctx->progress.extract.part_number = ctx->wim->hdr.part_number;
        ctx->progress.extract.total_parts = ctx->wim->hdr.total_parts;
        if (ctx->progress_func)
                ctx->progress_func(WIMLIB_PROGRESS_MSG_EXTRACT_SPWM_PART_BEGIN,
                                   &ctx->progress);
        while (ctx->num_streams_remaining) {
                if (found_lte->resource_location != RESOURCE_NONEXISTENT)
                        lte_unbind_wim_resource_spec(found_lte);
                ret = read_pwm_stream_header(ctx->wim, found_lte, rspec,
                                             pwm_flags, &pwm_hdr);
                if (ret) {
                        if (ret == WIMLIB_ERR_UNEXPECTED_END_OF_FILE &&
                            (ctx->extract_flags & WIMLIB_EXTRACT_FLAG_RESUME))
                        {
                                goto resume_done;
                        }
                        goto out_free_found_lte;
                }

                if ((found_lte->resource_location != RESOURCE_NONEXISTENT)
                    && !(found_lte->flags & WIM_RESHDR_FLAG_METADATA)
                    && (needed_lte = lookup_stream(lookup_table, found_lte->hash))
                    && (needed_lte->out_refcnt))
                {
                        tchar *tmpfile_name = NULL;
                        struct wim_lookup_table_entry *lte_override;
                        struct wim_lookup_table_entry tmpfile_lte;

                        needed_lte->offset_in_res = found_lte->offset_in_res;
                        needed_lte->flags = found_lte->flags;
                        needed_lte->size = found_lte->size;

                        lte_unbind_wim_resource_spec(found_lte);
                        lte_bind_wim_resource_spec(needed_lte, rspec);

                        if (needed_lte->out_refcnt > 1) {

                                struct filedes tmpfile_fd;

                                /* Extract stream to temporary file.  */
                                ret = create_temporary_file(&tmpfile_fd, &tmpfile_name);
                                if (ret) {
                                        lte_unbind_wim_resource_spec(needed_lte);
                                        goto out_free_found_lte;
                                }

                                ret = extract_full_stream_to_fd(needed_lte,
                                                                &tmpfile_fd);
                                if (ret) {
                                        filedes_close(&tmpfile_fd);
                                        goto delete_tmpfile;
                                }

                                if (filedes_close(&tmpfile_fd)) {
                                        ERROR_WITH_ERRNO("Error writing to temporary "
                                                         "file \"%"TS"\"", tmpfile_name);
                                        ret = WIMLIB_ERR_WRITE;
                                        goto delete_tmpfile;
                                }
                                memcpy(&tmpfile_lte, needed_lte,
                                       sizeof(struct wim_lookup_table_entry));
                                tmpfile_lte.resource_location = RESOURCE_IN_FILE_ON_DISK;
                                tmpfile_lte.file_on_disk = tmpfile_name;
                                lte_override = &tmpfile_lte;
                        } else {
                                lte_override = needed_lte;
                        }

                        ret = extract_stream_instances(needed_lte, lte_override, ctx);
                delete_tmpfile:
                        lte_unbind_wim_resource_spec(needed_lte);
                        if (tmpfile_name) {
                                tunlink(tmpfile_name);
                                FREE(tmpfile_name);
                        }
                        if (ret)
                                goto out_free_found_lte;
                        ctx->num_streams_remaining--;
                } else if (found_lte->resource_location != RESOURCE_NONEXISTENT) {
                        ret = skip_wim_stream(found_lte);
                        if (ret)
                                goto out_free_found_lte;
                } else {
                        u16 part_number = le16_to_cpu(pwm_hdr.part_number);
                        u16 total_parts = le16_to_cpu(pwm_hdr.total_parts);

                        if (part_number != ctx->progress.extract.part_number ||
                            total_parts != ctx->progress.extract.total_parts ||
                            memcmp(pwm_hdr.guid, ctx->progress.extract.guid,
                                   WIM_GID_LEN))
                        {
                                ctx->progress.extract.part_number = part_number;
                                ctx->progress.extract.total_parts = total_parts;
                                memcpy(ctx->progress.extract.guid,
                                       pwm_hdr.guid, WIM_GID_LEN);
                                if (ctx->progress_func) {
                                        ctx->progress_func(
                                                WIMLIB_PROGRESS_MSG_EXTRACT_SPWM_PART_BEGIN,
                                                           &ctx->progress);
                                }

                        }
                }
        }
        ret = 0;
out_free_found_lte:
        if (found_lte->resource_location != RESOURCE_IN_WIM)
                FREE(rspec);
        free_lookup_table_entry(found_lte);
out:
        return ret;

resume_done:
        /* TODO */
        return 0;
}

/* Extract a WIM dentry to standard output.
 *
 * This obviously doesn't make sense in all cases.  We return an error if the
 * dentry does not correspond to a regular file.  Otherwise we extract the
 * unnamed data stream only.  */
static int
extract_dentry_to_stdout(struct wim_dentry *dentry,
                         const struct wim_lookup_table *lookup_table)
{
        struct wim_inode *inode = dentry->d_inode;
        struct wim_lookup_table_entry *lte;
        struct filedes _stdout;

        if (inode->i_attributes & (FILE_ATTRIBUTE_REPARSE_POINT |
                                   FILE_ATTRIBUTE_DIRECTORY))
        {
                ERROR("\"%"TS"\" is not a regular file and therefore cannot be "
                      "extracted to standard output", dentry_full_path(dentry));
                return WIMLIB_ERR_NOT_A_REGULAR_FILE;
        }

        lte = inode_unnamed_lte(inode, lookup_table);
        if (!lte) {
                const u8 *hash = inode_unnamed_stream_hash(inode);
                if (!is_zero_hash(hash))
                        return stream_not_found_error(inode, hash);
                return 0;
        }

        filedes_init(&_stdout, STDOUT_FILENO);
        return extract_full_stream_to_fd(lte, &_stdout);
}

static int
extract_dentries_to_stdout(struct wim_dentry **dentries, size_t num_dentries,
                           const struct wim_lookup_table *lookup_table)
{
        for (size_t i = 0; i < num_dentries; i++) {
                int ret = extract_dentry_to_stdout(dentries[i], lookup_table);
                if (ret)
                        return ret;
        }
        return 0;
}

/**********************************************************************/

/*
 * Removes duplicate dentries from the array.
 *
 * Returns the new number of dentries, packed at the front of the array.
 */
static size_t
remove_duplicate_trees(struct wim_dentry **trees, size_t num_trees)
{
        size_t i, j = 0;
        for (i = 0; i < num_trees; i++) {
                if (!trees[i]->tmp_flag) {
                        /* Found distinct dentry.  */
                        trees[i]->tmp_flag = 1;
                        trees[j++] = trees[i];
                }
        }
        for (i = 0; i < j; i++)
                trees[i]->tmp_flag = 0;
        return j;
}

/*
 * Remove dentries that are descendants of other dentries in the array.
 *
 * Returns the new number of dentries, packed at the front of the array.
 */
static size_t
remove_contained_trees(struct wim_dentry **trees, size_t num_trees)
{
        size_t i, j = 0;
        for (i = 0; i < num_trees; i++)
                trees[i]->tmp_flag = 1;
        for (i = 0; i < num_trees; i++) {
                struct wim_dentry *d = trees[i];
                while (!dentry_is_root(d)) {
                        d = d->parent;
                        if (d->tmp_flag)
                                goto tree_contained;
                }
                trees[j++] = trees[i];
                continue;

        tree_contained:
                trees[i]->tmp_flag = 0;
        }

        for (i = 0; i < j; i++)
                trees[i]->tmp_flag = 0;
        return j;
}

static int
dentry_append_to_list(struct wim_dentry *dentry, void *_dentry_list)
{
        struct list_head *dentry_list = _dentry_list;
        list_add_tail(&dentry->extraction_list, dentry_list);
        return 0;
}

static void
dentry_reset_extraction_list_node(struct wim_dentry *dentry)
{
        dentry->extraction_list = (struct list_head){NULL, NULL};
}

static int
dentry_delete_from_list(struct wim_dentry *dentry, void *_ignore)
{
        list_del(&dentry->extraction_list);
        dentry_reset_extraction_list_node(dentry);
        return 0;
}

/*
 * Build the preliminary list of dentries to be extracted.
 *
 * The list maintains the invariant that if d1 and d2 are in the list and d1 is
 * an ancestor of d2, then d1 appears before d2 in the list.
 */
static void
build_dentry_list(struct list_head *dentry_list, struct wim_dentry **trees,
                  size_t num_trees, bool add_ancestors)
{
        INIT_LIST_HEAD(dentry_list);

        /* Add the trees recursively.  */
        for (size_t i = 0; i < num_trees; i++)
                for_dentry_in_tree(trees[i], dentry_append_to_list, dentry_list);

        /* If requested, add ancestors of the trees.  */
        if (add_ancestors) {
                for (size_t i = 0; i < num_trees; i++) {
                        struct wim_dentry *dentry = trees[i];
                        struct wim_dentry *ancestor;
                        struct list_head *place_after;

                        if (dentry_is_root(dentry))
                                continue;

                        place_after = dentry_list;
                        ancestor = dentry;
                        do {
                                ancestor = ancestor->parent;
                                if (dentry_in_list(ancestor)) {
                                        place_after = &ancestor->extraction_list;
                                        break;
                                }
                        } while (!dentry_is_root(ancestor));

                        ancestor = dentry;
                        do {
                                ancestor = ancestor->parent;
                                if (dentry_in_list(ancestor))
                                        break;
                                list_add(&ancestor->extraction_list, place_after);
                        } while (!dentry_is_root(ancestor));
                }
        }
}

static const struct apply_operations *
select_apply_operations(int extract_flags)
{
#ifdef WITH_NTFS_3G
        if (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS)
                return &ntfs_3g_apply_ops;
#endif
#ifdef __WIN32__
        return &win32_apply_ops;
#else
        return &unix_apply_ops;
#endif
}

#ifdef __WIN32__
static const utf16lechar replacement_char = cpu_to_le16(0xfffd);
#else
static const utf16lechar replacement_char = cpu_to_le16('?');
#endif

static bool
file_name_valid(utf16lechar *name, size_t num_chars, bool fix)
{
        size_t i;

        if (num_chars == 0)
                return true;
        for (i = 0; i < num_chars; i++) {
                switch (name[i]) {
        #ifdef __WIN32__
                case cpu_to_le16('\\'):
                case cpu_to_le16(':'):
                case cpu_to_le16('*'):
                case cpu_to_le16('?'):
                case cpu_to_le16('"'):
                case cpu_to_le16('<'):
                case cpu_to_le16('>'):
                case cpu_to_le16('|'):
        #endif
                case cpu_to_le16('/'):
                case cpu_to_le16('\0'):
                        if (fix)
                                name[i] = replacement_char;
                        else
                                return false;
                }
        }

#ifdef __WIN32__
        if (name[num_chars - 1] == cpu_to_le16(' ') ||
            name[num_chars - 1] == cpu_to_le16('.'))
        {
                if (fix)
                        name[num_chars - 1] = replacement_char;
                else
                        return false;
        }
#endif
        return true;
}

static int
dentry_calculate_extraction_name(struct wim_dentry *dentry,
                                 struct apply_ctx *ctx)
{
        int ret;

        if (dentry == ctx->target_dentry)
                return 0;

        if (!dentry_is_supported(dentry, &ctx->supported_features))
                goto skip_dentry;

        if (!ctx->ops->supports_case_sensitive_filenames)
        {
                struct wim_dentry *other;
                list_for_each_entry(other, &dentry->d_ci_conflict_list,
                                    d_ci_conflict_list)
                {
                        if (dentry_in_list(other)) {
                                if (ctx->extract_flags &
                                    WIMLIB_EXTRACT_FLAG_ALL_CASE_CONFLICTS) {
                                        WARNING("\"%"TS"\" has the same "
                                                "case-insensitive name as "
                                                "\"%"TS"\"; extracting "
                                                "dummy name instead",
                                                dentry_full_path(dentry),
                                                dentry_full_path(other));
                                        goto out_replace;
                                } else {
                                        WARNING("Not extracting \"%"TS"\": "
                                                "has same case-insensitive "
                                                "name as \"%"TS"\"",
                                                dentry_full_path(dentry),
                                                dentry_full_path(other));
                                        goto skip_dentry;
                                }
                        }
                }
        }

        if (file_name_valid(dentry->file_name, dentry->file_name_nbytes / 2, false)) {
#if TCHAR_IS_UTF16LE
                dentry->extraction_name = dentry->file_name;
                dentry->extraction_name_nchars = dentry->file_name_nbytes / 2;
                return 0;
#else
                return utf16le_to_tstr(dentry->file_name,
                                       dentry->file_name_nbytes,
                                       &dentry->extraction_name,
                                       &dentry->extraction_name_nchars);
#endif
        } else {
                if (ctx->extract_flags & WIMLIB_EXTRACT_FLAG_REPLACE_INVALID_FILENAMES)
                {
                        WARNING("\"%"TS"\" has an invalid filename "
                                "that is not supported on this platform; "
                                "extracting dummy name instead",
                                dentry_full_path(dentry));
                        goto out_replace;
                } else {
                        WARNING("Not extracting \"%"TS"\": has an invalid filename "
                                "that is not supported on this platform",
                                dentry_full_path(dentry));
                        goto skip_dentry;
                }
        }

out_replace:
        {
                utf16lechar utf16_name_copy[dentry->file_name_nbytes / 2];

                memcpy(utf16_name_copy, dentry->file_name, dentry->file_name_nbytes);
                file_name_valid(utf16_name_copy, dentry->file_name_nbytes / 2, true);

                tchar *tchar_name;
                size_t tchar_nchars;
        #if TCHAR_IS_UTF16LE
                tchar_name = utf16_name_copy;
                tchar_nchars = dentry->file_name_nbytes / 2;
        #else
                ret = utf16le_to_tstr(utf16_name_copy,
                                      dentry->file_name_nbytes,
                                      &tchar_name, &tchar_nchars);
                if (ret)
                        return ret;
        #endif
                size_t fixed_name_num_chars = tchar_nchars;
                tchar fixed_name[tchar_nchars + 50];

                tmemcpy(fixed_name, tchar_name, tchar_nchars);
                fixed_name_num_chars += tsprintf(fixed_name + tchar_nchars,
                                                 T(" (invalid filename #%lu)"),
                                                 ++ctx->invalid_sequence);
        #if !TCHAR_IS_UTF16LE
                FREE(tchar_name);
        #endif
                dentry->extraction_name = memdup(fixed_name,
                                                 2 * fixed_name_num_chars + 2);
                if (!dentry->extraction_name)
                        return WIMLIB_ERR_NOMEM;
                dentry->extraction_name_nchars = fixed_name_num_chars;
        }
        return 0;

skip_dentry:
        for_dentry_in_tree(dentry, dentry_delete_from_list, NULL);
        return 0;
}

/*
 * Calculate the actual filename component at which each WIM dentry will be
 * extracted, with special handling for dentries that are unsupported by the
 * extraction backend or have invalid names.
 *
 * Note: this has a dependency on start_extract() being called because
 * ctx.supported_features must be filled in in order to determine whether each
 * dentry is supported.
 *
 * Possible error codes: WIMLIB_ERR_NOMEM, WIMLIB_ERR_INVALID_UTF16_STRING
 */
static int
dentry_list_calculate_extraction_names(struct list_head *dentry_list,
                                       struct apply_ctx *ctx)
{
        struct list_head *prev, *cur;

        /* Can't use list_for_each_entry() because a call to
         * dentry_calculate_extraction_name() may delete the current dentry and
         * its children from the list.  */

        prev = dentry_list;
        for (;;) {
                struct wim_dentry *dentry;
                int ret;

                cur = prev->next;
                if (cur == dentry_list)
                        break;

                dentry = list_entry(cur, struct wim_dentry, extraction_list);

                ret = dentry_calculate_extraction_name(dentry, ctx);
                if (ret)
                        return ret;

                if (prev->next == cur)
                        prev = cur;
                else
                        ; /* Current dentry and its children (which follow in
                             the list) were deleted.  prev stays the same.  */
        }
        return 0;
}

static int
dentry_resolve_streams(struct wim_dentry *dentry, int extract_flags,
                       struct wim_lookup_table *lookup_table)
{
        struct wim_inode *inode = dentry->d_inode;
        struct wim_lookup_table_entry *lte;
        int ret;
        bool force = false;

        /* Special case:  when extracting from a pipe, the WIM lookup table is
         * initially empty, so "resolving" an inode's streams is initially not
         * possible.  However, we still need to keep track of which streams,
         * identified by SHA1 message digests, need to be extracted, so we
         * "resolve" the inode's streams anyway by allocating new entries.  */
        if (extract_flags & WIMLIB_EXTRACT_FLAG_FROM_PIPE)
                force = true;
        ret = inode_resolve_streams(inode, lookup_table, force);
        if (ret)
                return ret;
        for (u32 i = 0; i <= inode->i_num_ads; i++) {
                lte = inode_stream_lte_resolved(inode, i);
                if (lte)
                        lte->out_refcnt = 0;
        }
        return 0;
}

/*
 * For each dentry to be extracted, resolve all streams in the corresponding
 * inode and set 'out_refcnt' in each to 0.
 *
 * Possible error codes: WIMLIB_ERR_RESOURCE_NOT_FOUND, WIMLIB_ERR_NOMEM.
 */
static int
dentry_list_resolve_streams(struct list_head *dentry_list,
                            struct apply_ctx *ctx)
{
        struct wim_dentry *dentry;
        int ret;

        list_for_each_entry(dentry, dentry_list, extraction_list) {
                ret = dentry_resolve_streams(dentry,
                                             ctx->extract_flags,
                                             ctx->wim->lookup_table);
                if (ret)
                        return ret;
        }
        return 0;
}

static int
ref_stream(struct wim_lookup_table_entry *lte,
           struct wim_dentry *dentry, struct apply_ctx *ctx)
{
        if (!lte)
                return 0;

        /* Tally the size only for each extraction of the stream (not hard
         * links).  */
        if (!(dentry->d_inode->i_visited &&
              ctx->supported_features.hard_links) &&
            (!is_linked_extraction(ctx) || (lte->out_refcnt == 0 &&
                                            lte->extracted_file == NULL)))
        {
                ctx->progress.extract.total_bytes += lte->size;
                ctx->progress.extract.num_streams++;
        }

        /* Add stream to the dentry_list only one time, even if it's going
         * to be extracted to multiple locations.  */
        if (lte->out_refcnt == 0) {
                list_add_tail(&lte->extraction_list, &ctx->stream_list);
                ctx->num_streams_remaining++;
        }

        if (!(ctx->extract_flags & WIMLIB_EXTRACT_FLAG_FILE_ORDER)) {
                struct wim_dentry **lte_dentries;

                /* Append dentry to this stream's array of dentries referencing
                 * it.  Use inline array to avoid memory allocation until the
                 * number of dentries becomes too large.  */
                if (lte->out_refcnt < ARRAY_LEN(lte->inline_lte_dentries)) {
                        lte_dentries = lte->inline_lte_dentries;
                } else {
                        struct wim_dentry **prev_lte_dentries;
                        size_t alloc_lte_dentries;

                        if (lte->out_refcnt == ARRAY_LEN(lte->inline_lte_dentries)) {
                                prev_lte_dentries = NULL;
                                alloc_lte_dentries = ARRAY_LEN(lte->inline_lte_dentries);
                        } else {
                                prev_lte_dentries = lte->lte_dentries;
                                alloc_lte_dentries = lte->alloc_lte_dentries;
                        }

                        if (lte->out_refcnt == alloc_lte_dentries) {
                                alloc_lte_dentries *= 2;
                                lte_dentries = REALLOC(prev_lte_dentries,
                                                       alloc_lte_dentries *
                                                        sizeof(lte_dentries[0]));
                                if (lte_dentries == NULL)
                                        return WIMLIB_ERR_NOMEM;
                                if (prev_lte_dentries == NULL) {
                                        memcpy(lte_dentries,
                                               lte->inline_lte_dentries,
                                               sizeof(lte->inline_lte_dentries));
                                }
                                lte->lte_dentries = lte_dentries;
                                lte->alloc_lte_dentries = alloc_lte_dentries;
                        }
                        lte_dentries = lte->lte_dentries;
                }
                lte_dentries[lte->out_refcnt] = dentry;
        }
        lte->out_refcnt++;
        return 0;
}

static int
dentry_ref_streams(struct wim_dentry *dentry, struct apply_ctx *ctx)
{
        struct wim_inode *inode = dentry->d_inode;
        int ret;

        /* The unnamed data stream will always be extracted, except in an
         * unlikely case.  */
        if (!inode_is_encrypted_directory(inode)) {
                ret = ref_stream(inode_unnamed_lte_resolved(inode),
                                 dentry, ctx);
                if (ret)
                        return ret;
        }

        /* Named data streams will be extracted only if supported in the current
         * extraction mode and volume, and to avoid complications, if not doing
         * a linked extraction.  */
        if (can_extract_named_data_streams(ctx)) {
                for (u16 i = 0; i < inode->i_num_ads; i++) {
                        if (!ads_entry_is_named_stream(&inode->i_ads_entries[i]))
                                continue;
                        ret = ref_stream(inode->i_ads_entries[i].lte,
                                         dentry, ctx);
                        if (ret)
                                return ret;
                }
        }
        inode->i_visited = 1;
        return 0;
}

/*
 * For each dentry to be extracted, iterate through the data streams of the
 * corresponding inode.  For each such stream that is not to be ignored due to
 * the supported features or extraction flags, add it to the list of streams to
 * be extracted (ctx->stream_list) if not already done so.
 *
 * Also, if doing a sequential extraction, build a mapping from each stream to
 * the dentries referencing it.
 *
 * This also initializes the extract progress info with byte and stream
 * information.
 *
 * Note: This has a dependency on start_extract being called because
 * ctx.supported_features must be filled in in order to determine whether named
 * data streams are supported.
 *
 * Note: this uses the i_visited member of the inodes (assumed to be 0
 * initially), but does not reset it.
 *
 * Possible error codes: WIMLIB_ERR_NOMEM.
 */
static int
dentry_list_ref_streams(struct list_head *dentry_list, struct apply_ctx *ctx)
{
        struct wim_dentry *dentry;
        int ret;

        list_for_each_entry(dentry, dentry_list, extraction_list) {
                ret = dentry_ref_streams(dentry, ctx);
                if (ret)
                        return ret;
        }
        return 0;
}

/* Tally features necessary to extract a dentry and the corresponding inode.  */
static void
dentry_tally_features(struct wim_dentry *dentry, struct wim_features *features)
{
        struct wim_inode *inode = dentry->d_inode;

        if (inode->i_attributes & FILE_ATTRIBUTE_ARCHIVE)
                features->archive_files++;
        if (inode->i_attributes & FILE_ATTRIBUTE_HIDDEN)
                features->hidden_files++;
        if (inode->i_attributes & FILE_ATTRIBUTE_SYSTEM)
                features->system_files++;
        if (inode->i_attributes & FILE_ATTRIBUTE_COMPRESSED)
                features->compressed_files++;
        if (inode->i_attributes & FILE_ATTRIBUTE_ENCRYPTED) {
                if (inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY)
                        features->encrypted_directories++;
                else
                        features->encrypted_files++;
        }
        if (inode->i_attributes & FILE_ATTRIBUTE_NOT_CONTENT_INDEXED)
                features->not_context_indexed_files++;
        if (inode->i_attributes & FILE_ATTRIBUTE_SPARSE_FILE)
                features->sparse_files++;
        if (inode_has_named_stream(inode))
                features->named_data_streams++;
        if (inode->i_visited)
                features->hard_links++;
        if (inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
                features->reparse_points++;
                if (inode_is_symlink(inode))
                        features->symlink_reparse_points++;
                else
                        features->other_reparse_points++;
        }
        if (inode->i_security_id != -1)
                features->security_descriptors++;
        if (dentry->short_name_nbytes)
                features->short_names++;
        if (inode_has_unix_data(inode))
                features->unix_data++;
        inode->i_visited = 1;
}

/* Tally the features necessary to extract the specified dentries.  */
static void
dentry_list_get_features(struct list_head *dentry_list,
                         struct wim_features *features)
{
        struct wim_dentry *dentry;

        memset(features, 0, sizeof(struct wim_features));

        list_for_each_entry(dentry, dentry_list, extraction_list)
                dentry_tally_features(dentry, features);

        list_for_each_entry(dentry, dentry_list, extraction_list)
                dentry->d_inode->i_visited = 0;
}

static u32
compute_supported_attributes_mask(const struct wim_features *supported_features)
{
        u32 mask = (u32)~0UL;

        if (!supported_features->archive_files)
                mask &= ~FILE_ATTRIBUTE_ARCHIVE;

        if (!supported_features->hidden_files)
                mask &= ~FILE_ATTRIBUTE_HIDDEN;

        if (!supported_features->system_files)
                mask &= ~FILE_ATTRIBUTE_SYSTEM;

        if (!supported_features->not_context_indexed_files)
                mask &= ~FILE_ATTRIBUTE_NOT_CONTENT_INDEXED;

        if (!supported_features->compressed_files)
                mask &= ~FILE_ATTRIBUTE_COMPRESSED;

        if (!supported_features->sparse_files)
                mask &= ~FILE_ATTRIBUTE_SPARSE_FILE;

        if (!supported_features->reparse_points)
                mask &= ~FILE_ATTRIBUTE_REPARSE_POINT;

        return mask;
}

static int
do_feature_check(const struct wim_features *required_features,
                 const struct wim_features *supported_features,
                 int extract_flags, const struct apply_operations *ops)
{
        /* File attributes.  */
        if (!(extract_flags & WIMLIB_EXTRACT_FLAG_NO_ATTRIBUTES)) {
                /* Note: Don't bother the user about FILE_ATTRIBUTE_ARCHIVE.
                 * We're an archive program, so theoretically we can do what we
                 * want with it.  */

                if (required_features->hidden_files &&
                    !supported_features->hidden_files)
                        WARNING("Ignoring FILE_ATTRIBUTE_HIDDEN of %lu files",
                                required_features->hidden_files);

                if (required_features->system_files &&
                    !supported_features->system_files)
                        WARNING("Ignoring FILE_ATTRIBUTE_SYSTEM of %lu files",
                                required_features->system_files);

                if (required_features->compressed_files &&
                    !supported_features->compressed_files)
                        WARNING("Ignoring FILE_ATTRIBUTE_COMPRESSED of %lu files",
                                required_features->compressed_files);

                if (required_features->not_context_indexed_files &&
                    !supported_features->not_context_indexed_files)
                        WARNING("Ignoring FILE_ATTRIBUTE_NOT_CONTENT_INDEXED of %lu files",
                                required_features->not_context_indexed_files);

                if (required_features->sparse_files &&
                    !supported_features->sparse_files)
                        WARNING("Ignoring FILE_ATTRIBUTE_SPARSE_FILE of %lu files",
                                required_features->sparse_files);

                if (required_features->encrypted_directories &&
                    !supported_features->encrypted_directories)
                        WARNING("Ignoring FILE_ATTRIBUTE_ENCRYPTED of %lu directories",
                                required_features->encrypted_directories);
        }

        /* Encrypted files.  */
        if (required_features->encrypted_files &&
            !supported_features->encrypted_files)
                WARNING("Ignoring %lu encrypted files",
                        required_features->encrypted_files);

        /* Named data streams.  */
        if (required_features->named_data_streams &&
            (!supported_features->named_data_streams ||
             (extract_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK |
                               WIMLIB_EXTRACT_FLAG_HARDLINK))))
                WARNING("Ignoring named data streams of %lu files",
                        required_features->named_data_streams);

        /* Hard links.  */
        if ((extract_flags & WIMLIB_EXTRACT_FLAG_HARDLINK) &&
            !supported_features->hard_links)
        {
                ERROR("Extraction backend does not support hard links!");
                return WIMLIB_ERR_UNSUPPORTED;
        }
        if (required_features->hard_links && !supported_features->hard_links)
                WARNING("Extracting %lu hard links as independent files",
                        required_features->hard_links);

        /* Symbolic links and reparse points.  */
        if ((extract_flags & WIMLIB_EXTRACT_FLAG_SYMLINK) &&
            !supported_features->symlink_reparse_points)
        {
                ERROR("Extraction backend does not support symbolic links!");
                return WIMLIB_ERR_UNSUPPORTED;
        }
        if ((extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_SYMLINKS) &&
            required_features->symlink_reparse_points &&
            !supported_features->symlink_reparse_points &&
            !supported_features->reparse_points)
        {
                ERROR("Extraction backend does not support symbolic links!");
                return WIMLIB_ERR_UNSUPPORTED;
        }
        if (required_features->reparse_points &&
            !supported_features->reparse_points)
        {
                if (supported_features->symlink_reparse_points) {
                        if (required_features->other_reparse_points) {
                                WARNING("Ignoring %lu non-symlink/junction "
                                        "reparse point files",
                                        required_features->other_reparse_points);
                        }
                } else {
                        WARNING("Ignoring %lu reparse point files",
                                required_features->reparse_points);
                }
        }

        /* Security descriptors.  */
        if (((extract_flags & (WIMLIB_EXTRACT_FLAG_STRICT_ACLS |
                               WIMLIB_EXTRACT_FLAG_UNIX_DATA))
             == WIMLIB_EXTRACT_FLAG_STRICT_ACLS) &&
            required_features->security_descriptors &&
            !supported_features->security_descriptors)
        {
                ERROR("Extraction backend does not support security descriptors!");
                return WIMLIB_ERR_UNSUPPORTED;
        }
        if (!(extract_flags & WIMLIB_EXTRACT_FLAG_NO_ACLS) &&
            required_features->security_descriptors &&
            !supported_features->security_descriptors)
                WARNING("Ignoring Windows NT security descriptors of %lu files",
                        required_features->security_descriptors);

        /* UNIX data.  */
        if ((extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA) &&
            required_features->unix_data && !supported_features->unix_data)
        {
                ERROR("Extraction backend does not support UNIX data!");
                return WIMLIB_ERR_UNSUPPORTED;
        }

        /* DOS Names.  */
        if (required_features->short_names &&
            !supported_features->short_names)
        {
                if (extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_SHORT_NAMES) {
                        ERROR("Extraction backend does not support DOS names!");
                        return WIMLIB_ERR_UNSUPPORTED;
                }
                WARNING("Ignoring DOS names of %lu files",
                        required_features->short_names);
        }

        /* Timestamps.  */
        if ((extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_TIMESTAMPS) &&
            !ops->set_timestamps)
        {
                ERROR("Extraction backend does not support timestamps!");
                return WIMLIB_ERR_UNSUPPORTED;
        }

        return 0;
}

static void
do_extract_warnings(struct apply_ctx *ctx)
{
        if (ctx->partial_security_descriptors == 0 &&
            ctx->no_security_descriptors == 0)
                return;

        WARNING("Extraction to \"%"TS"\" complete, but with one or more warnings:",
                ctx->target);
        if (ctx->partial_security_descriptors != 0) {
                WARNING("- Could only partially set the security descriptor\n"
                        "            on %lu files or directories.",
                        ctx->partial_security_descriptors);
        }
        if (ctx->no_security_descriptors != 0) {
                WARNING("- Could not set security descriptor at all\n"
                        "            on %lu files or directories.",
                        ctx->no_security_descriptors);
        }
#ifdef __WIN32__
        WARNING("To fully restore all security descriptors, run the program\n"
                "          with Administrator rights.");
#endif
}

static void
destroy_dentry_list(struct list_head *dentry_list)
{
        struct wim_dentry *dentry, *tmp;
        struct wim_inode *inode;

        list_for_each_entry_safe(dentry, tmp, dentry_list, extraction_list) {
                inode = dentry->d_inode;
                dentry_reset_extraction_list_node(dentry);
                dentry->was_linked = 0;
                dentry->skeleton_extracted = 0;
                inode->i_visited = 0;
                FREE(inode->i_extracted_file);
                inode->i_extracted_file = NULL;
                inode->i_dos_name_extracted = 0;
                if ((void*)dentry->extraction_name != (void*)dentry->file_name)
                        FREE(dentry->extraction_name);
                dentry->extraction_name = NULL;
        }
}

static void
destroy_stream_list(struct list_head *stream_list)
{
        struct wim_lookup_table_entry *lte;

        list_for_each_entry(lte, stream_list, extraction_list)
                if (lte->out_refcnt > ARRAY_LEN(lte->inline_lte_dentries))
                        FREE(lte->lte_dentries);
}

static int
extract_trees(WIMStruct *wim, struct wim_dentry **trees, size_t num_trees,
              const tchar *target, int extract_flags,
              wimlib_progress_func_t progress_func)
{
        int ret;
        struct apply_ctx ctx;
        struct list_head dentry_list;
        struct wim_features required_features;

        /* Handle stdout extraction as a separate case.  */
        if (extract_flags & WIMLIB_EXTRACT_FLAG_TO_STDOUT)
                return extract_dentries_to_stdout(trees, num_trees,
                                                  wim->lookup_table);

        /* Start initializing the apply_ctx.  */
        memset(&ctx, 0, sizeof(struct apply_ctx));
        ctx.wim = wim;
        ctx.extract_flags = extract_flags;
        ctx.target = target;
        ctx.target_nchars = tstrlen(target);
        ctx.progress_func = progress_func;
        if (progress_func) {
                ctx.progress.extract.wimfile_name = wim->filename;
                ctx.progress.extract.image = wim->current_image;
                ctx.progress.extract.extract_flags = (extract_flags &
                                                      WIMLIB_EXTRACT_MASK_PUBLIC);
                ctx.progress.extract.image_name = wimlib_get_image_name(wim,
                                                                        wim->current_image);
                ctx.progress.extract.target = target;
        }

        if (extract_flags & WIMLIB_EXTRACT_FLAG_FILEMODE) {
                /* Called from wimlib_extract_files().  There should be only 1
                 * tree, and directory structure should not be preserved.  */
                wimlib_assert(num_trees == 1);
                wimlib_assert(extract_flags &
                              WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE);
                ret = calculate_dentry_full_path(trees[0]);
                if (ret)
                        return ret;
                ctx.progress.extract.extract_root_wim_source_path = trees[0]->_full_path;
                ctx.target_dentry = trees[0];
        } else {
                ctx.progress.extract.extract_root_wim_source_path = T("");
                ctx.target_dentry = wim_root_dentry(wim);
        }
        /* Note: ctx.target_dentry represents the dentry that gets extracted to
         * @target.  There may be none, in which case it gets set to the image
         * root and never matches any of the dentries actually being extracted.
         */

        num_trees = remove_duplicate_trees(trees, num_trees);

        /* All trees are now distinct.  */

        num_trees = remove_contained_trees(trees, num_trees);

        /* All trees are now distinct and non-overlapping.  */

        /* Build list of dentries to be extracted.  */
        build_dentry_list(&dentry_list, trees, num_trees,
                          !(extract_flags & WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE));

        /* Select the appropriate apply_operations based on the platform and
         * extract_flags.  */
        ctx.ops = select_apply_operations(extract_flags);

        /* Figure out whether the root dentry is being extracted to the root of
         * a volume and therefore needs to be treated "specially", for example
         * not being explicitly created and not having attributes set.  */
        if (ctx.ops->target_is_root && ctx.ops->root_directory_is_special)
                ctx.root_dentry_is_special = ctx.ops->target_is_root(target);

        /* Call the start_extract() callback.  This gives the apply_operations
         * implementation a chance to do any setup needed to access the volume.
         * Furthermore, start_extract() is expected to set the supported
         * features of this extraction mode (ctx.supported_features), which are
         * determined at runtime as they may vary depending on the actual
         * volume.  */
        ret = ctx.ops->start_extract(target, &ctx);
        if (ret)
                goto out_destroy_dentry_list;

        /* Get and check the features required to extract the dentries.  */
        dentry_list_get_features(&dentry_list, &required_features);
        ret = do_feature_check(&required_features, &ctx.supported_features,
                               extract_flags, ctx.ops);
        if (ret)
                goto out_finish_or_abort_extract;

        ctx.supported_attributes_mask =
                compute_supported_attributes_mask(&ctx.supported_features);

        /* Calculate extraction name for each dentry and remove subtrees that
         * can't be extracted due to naming problems.  */
        ret = dentry_list_calculate_extraction_names(&dentry_list, &ctx);
        if (ret)
                goto out_finish_or_abort_extract;

        /* Build list of streams to extract.  */
        ret = dentry_list_resolve_streams(&dentry_list, &ctx);
        if (ret)
                goto out_finish_or_abort_extract;
        INIT_LIST_HEAD(&ctx.stream_list);
        ret = dentry_list_ref_streams(&dentry_list, &ctx);
        if (ret)
                goto out_destroy_stream_list;

        if (extract_flags & WIMLIB_EXTRACT_FLAG_FROM_PIPE) {
                /* When extracting from a pipe, the number of bytes of data to
                 * extract can't be determined in the normal way (examining the
                 * lookup table), since at this point all we have is a set of
                 * SHA1 message digests of streams that need to be extracted.
                 * However, we can get a reasonably accurate estimate by taking
                 * <TOTALBYTES> from the corresponding <IMAGE> in the WIM XML
                 * data.  This does assume that a full image is being extracted,
                 * but currently there is no API for doing otherwise.  (Also,
                 * subtract <HARDLINKBYTES> from this if hard links are
                 * supported by the extraction mode.)  */
                ctx.progress.extract.total_bytes =
                        wim_info_get_image_total_bytes(wim->wim_info,
                                                       wim->current_image);
                if (ctx.supported_features.hard_links) {
                        ctx.progress.extract.total_bytes -=
                                wim_info_get_image_hard_link_bytes(wim->wim_info,
                                                                   wim->current_image);
                }
        }

        if (ctx.ops->realpath_works_on_nonexisting_files &&
            ((extract_flags & WIMLIB_EXTRACT_FLAG_RPFIX) ||
             ctx.ops->requires_realtarget_in_paths))
        {
                ctx.realtarget = realpath(target, NULL);
                if (!ctx.realtarget) {
                        ret = WIMLIB_ERR_NOMEM;
                        goto out_destroy_stream_list;
                }
                ctx.realtarget_nchars = tstrlen(ctx.realtarget);
        }

        if (progress_func) {
                int msg;
                if (extract_flags & WIMLIB_EXTRACT_FLAG_IMAGEMODE)
                        msg = WIMLIB_PROGRESS_MSG_EXTRACT_IMAGE_BEGIN;
                else
                        msg = WIMLIB_PROGRESS_MSG_EXTRACT_TREE_BEGIN;
                progress_func(msg, &ctx.progress);
        }

        if (!ctx.root_dentry_is_special) {
                tchar path[ctx.ops->path_max];
                if (build_extraction_path(path, ctx.target_dentry, &ctx)) {
                        ret = extract_inode(path, &ctx, ctx.target_dentry->d_inode);
                        if (ret)
                                goto out_free_realtarget;
                }
        }

        /* If we need to fix up the targets of absolute symbolic links
         * (WIMLIB_EXTRACT_FLAG_RPFIX) or the extraction mode requires paths to
         * be absolute, use realpath() (or its replacement on Windows) to get
         * the absolute path to the extraction target.  Note that this requires
         * the target directory to exist, unless
         * realpath_works_on_nonexisting_files is set in the apply_operations.
         * */
        if (!ctx.realtarget &&
            (((extract_flags & WIMLIB_EXTRACT_FLAG_RPFIX) &&
              required_features.symlink_reparse_points) ||
             ctx.ops->requires_realtarget_in_paths))
        {
                ctx.realtarget = realpath(target, NULL);
                if (!ctx.realtarget) {
                        ret = WIMLIB_ERR_NOMEM;
                        goto out_free_realtarget;
                }
                ctx.realtarget_nchars = tstrlen(ctx.realtarget);
        }

        if (ctx.ops->requires_short_name_reordering) {
                if (progress_func)
                        progress_func(WIMLIB_PROGRESS_MSG_EXTRACT_DIR_STRUCTURE_BEGIN,
                                      &ctx.progress);
                ret = extract_dir_structure(&dentry_list, &ctx);
                if (ret)
                        goto out_free_realtarget;
        }

        /* Finally, the important part: extract the tree of files.  */
        if (!(extract_flags & WIMLIB_EXTRACT_FLAG_FILE_ORDER)) {
                /* Sequential extraction requested, so two passes are needed
                 * (one for file structure, one for streams.)  */
                if (progress_func && !ctx.ops->requires_short_name_reordering)
                        progress_func(WIMLIB_PROGRESS_MSG_EXTRACT_DIR_STRUCTURE_BEGIN,
                                      &ctx.progress);

                if (!(extract_flags & WIMLIB_EXTRACT_FLAG_RESUME)) {
                        ret = extract_structure(&dentry_list, &ctx);
                        if (ret)
                                goto out_free_realtarget;
                }
                if (progress_func)
                        progress_func(WIMLIB_PROGRESS_MSG_EXTRACT_DIR_STRUCTURE_END,
                                      &ctx.progress);
                if (extract_flags & WIMLIB_EXTRACT_FLAG_FROM_PIPE)
                        ret = extract_streams_from_pipe(&ctx);
                else
                        ret = extract_stream_list(&ctx);
                if (ret)
                        goto out_free_realtarget;
        } else {
                /* Sequential extraction was not requested, so we can make do
                 * with one pass where we both create the files and extract
                 * streams.   */
                if (progress_func && !ctx.ops->requires_short_name_reordering)
                        progress_func(WIMLIB_PROGRESS_MSG_EXTRACT_DIR_STRUCTURE_BEGIN,
                                      &ctx.progress);
                ret = extract_dentries(&dentry_list, &ctx);
                if (ret)
                        goto out_free_realtarget;
                if (progress_func)
                        progress_func(WIMLIB_PROGRESS_MSG_EXTRACT_DIR_STRUCTURE_END,
                                      &ctx.progress);
        }

        /* If the total number of bytes to extract was miscalculated, just jump
         * to the calculated number in order to avoid confusing the progress
         * function.  This should only occur when extracting from a pipe.  */
        if (ctx.progress.extract.completed_bytes != ctx.progress.extract.total_bytes)
        {
                DEBUG("Calculated %"PRIu64" bytes to extract, but actually "
                      "extracted %"PRIu64,
                      ctx.progress.extract.total_bytes,
                      ctx.progress.extract.completed_bytes);
        }
        if (progress_func &&
            ctx.progress.extract.completed_bytes < ctx.progress.extract.total_bytes)
        {
                ctx.progress.extract.completed_bytes = ctx.progress.extract.total_bytes;
                progress_func(WIMLIB_PROGRESS_MSG_EXTRACT_STREAMS, &ctx.progress);
        }

        /* Apply security descriptors and timestamps.  This is done at the end,
         * and in a depth-first manner, to prevent timestamps from getting
         * changed by subsequent extract operations and to minimize the chance
         * of the restored security descriptors getting in our way.  */
        if (progress_func)
                progress_func(WIMLIB_PROGRESS_MSG_APPLY_TIMESTAMPS,
                              &ctx.progress);
        ret = extract_final_metadata(&dentry_list, &ctx);
        if (ret)
                goto out_free_realtarget;

        if (progress_func) {
                int msg;
                if (extract_flags & WIMLIB_EXTRACT_FLAG_IMAGEMODE)
                        msg = WIMLIB_PROGRESS_MSG_EXTRACT_IMAGE_END;
                else
                        msg = WIMLIB_PROGRESS_MSG_EXTRACT_TREE_END;
                progress_func(msg, &ctx.progress);
        }
        do_extract_warnings(&ctx);
        ret = 0;
out_free_realtarget:
        FREE(ctx.realtarget);
out_destroy_stream_list:
        if (!(ctx.extract_flags & WIMLIB_EXTRACT_FLAG_FILE_ORDER))
                destroy_stream_list(&ctx.stream_list);
out_finish_or_abort_extract:
        if (ret) {
                if (ctx.ops->abort_extract)
                        ctx.ops->abort_extract(&ctx);
        } else {
                if (ctx.ops->finish_extract)
                        ret = ctx.ops->finish_extract(&ctx);
        }
out_destroy_dentry_list:
        destroy_dentry_list(&dentry_list);
        return ret;
}

static int
mkdir_if_needed(const tchar *target)
{
        struct stat stbuf;
        if (tstat(target, &stbuf)) {
                if (errno == ENOENT) {
                        if (tmkdir(target, 0755)) {
                                ERROR_WITH_ERRNO("Failed to create directory "
                                                 "\"%"TS"\"", target);
                                return WIMLIB_ERR_MKDIR;
                        }
                } else {
                        ERROR_WITH_ERRNO("Failed to stat \"%"TS"\"", target);
                        return WIMLIB_ERR_STAT;
                }
        } else if (!S_ISDIR(stbuf.st_mode)) {
                ERROR("\"%"TS"\" is not a directory", target);
                return WIMLIB_ERR_NOTDIR;
        }
        return 0;
}

/* Make sure the extraction flags make sense, and update them if needed.  */
static int
check_extract_flags(const WIMStruct *wim, int *extract_flags_p)
{
        int extract_flags = *extract_flags_p;

        /* Check for invalid flag combinations  */
        if ((extract_flags &
             (WIMLIB_EXTRACT_FLAG_SYMLINK |
              WIMLIB_EXTRACT_FLAG_HARDLINK)) == (WIMLIB_EXTRACT_FLAG_SYMLINK |
                                                 WIMLIB_EXTRACT_FLAG_HARDLINK))
                return WIMLIB_ERR_INVALID_PARAM;

        if ((extract_flags &
             (WIMLIB_EXTRACT_FLAG_NO_ACLS |
              WIMLIB_EXTRACT_FLAG_STRICT_ACLS)) == (WIMLIB_EXTRACT_FLAG_NO_ACLS |
                                                    WIMLIB_EXTRACT_FLAG_STRICT_ACLS))
                return WIMLIB_ERR_INVALID_PARAM;

        if ((extract_flags &
             (WIMLIB_EXTRACT_FLAG_RPFIX |
              WIMLIB_EXTRACT_FLAG_NORPFIX)) == (WIMLIB_EXTRACT_FLAG_RPFIX |
                                                WIMLIB_EXTRACT_FLAG_NORPFIX))
                return WIMLIB_ERR_INVALID_PARAM;

        if ((extract_flags &
             (WIMLIB_EXTRACT_FLAG_RESUME |
              WIMLIB_EXTRACT_FLAG_FROM_PIPE)) == WIMLIB_EXTRACT_FLAG_RESUME)
                return WIMLIB_ERR_INVALID_PARAM;

#ifndef WITH_NTFS_3G
        if (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS) {
                ERROR("wimlib was compiled without support for NTFS-3g, so\n"
                      "        it cannot apply a WIM image directly to a NTFS volume.");
                return WIMLIB_ERR_UNSUPPORTED;
        }
#endif

#ifndef __WIN32__
        if (extract_flags & WIMLIB_EXTRACT_FLAG_WIMBOOT) {
                ERROR("WIMBoot extraction is only supported on Windows!");
                return WIMLIB_ERR_UNSUPPORTED;
        }
#endif

        if ((extract_flags & (WIMLIB_EXTRACT_FLAG_RPFIX |
                              WIMLIB_EXTRACT_FLAG_NORPFIX |
                              WIMLIB_EXTRACT_FLAG_IMAGEMODE)) ==
                                        WIMLIB_EXTRACT_FLAG_IMAGEMODE)
        {
                /* For full-image extraction, do reparse point fixups by default
                 * if the WIM header says they are enabled.  */
                if (wim->hdr.flags & WIM_HDR_FLAG_RP_FIX)
                        extract_flags |= WIMLIB_EXTRACT_FLAG_RPFIX;
        }

        /* TODO: Since UNIX data entries are stored in the file resources, in a
         * completely sequential extraction they may come up before the
         * corresponding file or symbolic link data.  This needs to be handled
         * better.  */
        if ((extract_flags & (WIMLIB_EXTRACT_FLAG_UNIX_DATA |
                              WIMLIB_EXTRACT_FLAG_FILE_ORDER))
                                    == WIMLIB_EXTRACT_FLAG_UNIX_DATA)
        {
                if (extract_flags & WIMLIB_EXTRACT_FLAG_FROM_PIPE) {
                        WARNING("Setting UNIX file/owner group may "
                                "be impossible on some\n"
                                "          symbolic links "
                                "when applying from a pipe.");
                } else {
                        extract_flags |= WIMLIB_EXTRACT_FLAG_FILE_ORDER;
                        WARNING("Disabling sequential extraction for "
                                "UNIX data mode");
                }
        }

        *extract_flags_p = extract_flags;
        return 0;
}

static u32
get_wildcard_flags(int extract_flags)
{
        u32 wildcard_flags = 0;

        if (extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_GLOB)
                wildcard_flags |= WILDCARD_FLAG_ERROR_IF_NO_MATCH;
        else
                wildcard_flags |= WILDCARD_FLAG_WARN_IF_NO_MATCH;

        if (default_ignore_case)
                wildcard_flags |= WILDCARD_FLAG_CASE_INSENSITIVE;

        return wildcard_flags;
}

struct append_dentry_ctx {
        struct wim_dentry **dentries;
        size_t num_dentries;
        size_t num_alloc_dentries;
};

static int
append_dentry_cb(struct wim_dentry *dentry, void *_ctx)
{
        struct append_dentry_ctx *ctx = _ctx;

        if (ctx->num_dentries == ctx->num_alloc_dentries) {
                struct wim_dentry **new_dentries;
                size_t new_length;

                new_length = max(ctx->num_alloc_dentries + 8,
                                 ctx->num_alloc_dentries * 3 / 2);
                new_dentries = REALLOC(ctx->dentries,
                                       new_length * sizeof(ctx->dentries[0]));
                if (new_dentries == NULL)
                        return WIMLIB_ERR_NOMEM;
                ctx->dentries = new_dentries;
                ctx->num_alloc_dentries = new_length;
        }
        ctx->dentries[ctx->num_dentries++] = dentry;
        return 0;
}

static int
do_wimlib_extract_paths(WIMStruct *wim, int image, const tchar *target,
                        const tchar * const *paths, size_t num_paths,
                        int extract_flags, wimlib_progress_func_t progress_func)
{
        int ret;
        struct wim_dentry **trees;
        size_t num_trees;

        if (wim == NULL || target == NULL || target[0] == T('\0') ||
            (num_paths != 0 && paths == NULL))
                return WIMLIB_ERR_INVALID_PARAM;

        ret = check_extract_flags(wim, &extract_flags);
        if (ret)
                return ret;

        ret = select_wim_image(wim, image);
        if (ret)
                return ret;

        ret = wim_checksum_unhashed_streams(wim);
        if (ret)
                return ret;

        if ((extract_flags & (WIMLIB_EXTRACT_FLAG_NTFS |
                              WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE |
                              WIMLIB_EXTRACT_FLAG_FILEMODE)) ==
            (WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE))
        {
                ret = mkdir_if_needed(target);
                if (ret)
                        return ret;
        }

        if (extract_flags & WIMLIB_EXTRACT_FLAG_GLOB_PATHS) {

                struct append_dentry_ctx append_dentry_ctx = {
                        .dentries = NULL,
                        .num_dentries = 0,
                        .num_alloc_dentries = 0,
                };

                u32 wildcard_flags = get_wildcard_flags(extract_flags);

                for (size_t i = 0; i < num_paths; i++) {
                        tchar *path = canonicalize_wim_path(paths[i]);
                        if (path == NULL) {
                                ret = WIMLIB_ERR_NOMEM;
                                trees = append_dentry_ctx.dentries;
                                goto out_free_trees;
                        }
                        ret = expand_wildcard(wim, path,
                                              append_dentry_cb,
                                              &append_dentry_ctx,
                                              wildcard_flags);
                        FREE(path);
                        if (ret) {
                                trees = append_dentry_ctx.dentries;
                                goto out_free_trees;
                        }
                }
                trees = append_dentry_ctx.dentries;
                num_trees = append_dentry_ctx.num_dentries;
        } else {
                trees = MALLOC(num_paths * sizeof(trees[0]));
                if (trees == NULL)
                        return WIMLIB_ERR_NOMEM;

                for (size_t i = 0; i < num_paths; i++) {

                        tchar *path = canonicalize_wim_path(paths[i]);
                        if (path == NULL) {
                                ret = WIMLIB_ERR_NOMEM;
                                goto out_free_trees;
                        }

                        trees[i] = get_dentry(wim, path,
                                              WIMLIB_CASE_PLATFORM_DEFAULT);
                        FREE(path);
                        if (trees[i] == NULL) {
                                  ERROR("Path \"%"TS"\" does not exist "
                                        "in WIM image %d",
                                        paths[i], wim->current_image);
                                  ret = WIMLIB_ERR_PATH_DOES_NOT_EXIST;
                                  goto out_free_trees;
                        }
                }
                num_trees = num_paths;
        }

        if (num_trees == 0) {
                ret = 0;
                goto out_free_trees;
        }

        ret = extract_trees(wim, trees, num_trees,
                            target, extract_flags, progress_func);
out_free_trees:
        FREE(trees);
        return ret;
}

static int
extract_single_image(WIMStruct *wim, int image,
                     const tchar *target, int extract_flags,
                     wimlib_progress_func_t progress_func)
{
        const tchar *path = T("");
        extract_flags |= WIMLIB_EXTRACT_FLAG_IMAGEMODE;
        return do_wimlib_extract_paths(wim, image, target, &path, 1,
                                       extract_flags, progress_func);
}

static const tchar * const filename_forbidden_chars =
T(
#ifdef __WIN32__
"<>:\"/\\|?*"
#else
"/"
#endif
);

/* This function checks if it is okay to use a WIM image's name as a directory
 * name.  */
static bool
image_name_ok_as_dir(const tchar *image_name)
{
        return image_name && *image_name &&
                !tstrpbrk(image_name, filename_forbidden_chars) &&
                tstrcmp(image_name, T(".")) &&
                tstrcmp(image_name, T(".."));
}

/* Extracts all images from the WIM to the directory @target, with the images
 * placed in subdirectories named by their image names. */
static int
extract_all_images(WIMStruct *wim,
                   const tchar *target,
                   int extract_flags,
                   wimlib_progress_func_t progress_func)
{
        size_t image_name_max_len = max(xml_get_max_image_name_len(wim), 20);
        size_t output_path_len = tstrlen(target);
        tchar buf[output_path_len + 1 + image_name_max_len + 1];
        int ret;
        int image;
        const tchar *image_name;

        extract_flags |= WIMLIB_EXTRACT_FLAG_MULTI_IMAGE;

        if (extract_flags & WIMLIB_EXTRACT_FLAG_NTFS) {
                ERROR("Cannot extract multiple images in NTFS extraction mode.");
                return WIMLIB_ERR_INVALID_PARAM;
        }

        ret = mkdir_if_needed(target);
        if (ret)
                return ret;
        tmemcpy(buf, target, output_path_len);
        buf[output_path_len] = OS_PREFERRED_PATH_SEPARATOR;
        for (image = 1; image <= wim->hdr.image_count; image++) {
                image_name = wimlib_get_image_name(wim, image);
                if (image_name_ok_as_dir(image_name)) {
                        tstrcpy(buf + output_path_len + 1, image_name);
                } else {
                        /* Image name is empty or contains forbidden characters.
                         * Use image number instead. */
                        tsprintf(buf + output_path_len + 1, T("%d"), image);
                }
                ret = extract_single_image(wim, image, buf, extract_flags,
                                           progress_func);
                if (ret)
                        return ret;
        }
        return 0;
}

static void
clear_lte_extracted_file(WIMStruct *wim, int extract_flags)
{
        if (unlikely(extract_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK |
                                      WIMLIB_EXTRACT_FLAG_HARDLINK)))
                for_lookup_table_entry(wim->lookup_table,
                                       lte_free_extracted_file, NULL);
}

static int
do_wimlib_extract_image(WIMStruct *wim,
                        int image,
                        const tchar *target,
                        int extract_flags,
                        wimlib_progress_func_t progress_func)
{
        int ret;

        if (extract_flags & (WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE |
                             WIMLIB_EXTRACT_FLAG_TO_STDOUT |
                             WIMLIB_EXTRACT_FLAG_GLOB_PATHS))
                return WIMLIB_ERR_INVALID_PARAM;

        if (image == WIMLIB_ALL_IMAGES)
                ret = extract_all_images(wim, target, extract_flags,
                                         progress_func);
        else
                ret = extract_single_image(wim, image, target, extract_flags,
                                           progress_func);

        clear_lte_extracted_file(wim, extract_flags);
        return ret;
}


/****************************************************************************
 *                          Extraction API                                  *
 ****************************************************************************/

/* Note: new code should use wimlib_extract_paths() instead of
 * wimlib_extract_files() if possible.  */
WIMLIBAPI int
wimlib_extract_files(WIMStruct *wim, int image,
                     const struct wimlib_extract_command *cmds, size_t num_cmds,
                     int default_extract_flags,
                     wimlib_progress_func_t progress_func)
{
        int all_flags = 0;
        int link_flags;
        int ret;

        if (num_cmds == 0)
                return 0;

        default_extract_flags |= WIMLIB_EXTRACT_FLAG_NO_PRESERVE_DIR_STRUCTURE;

        for (size_t i = 0; i < num_cmds; i++) {
                int cmd_flags = (cmds[i].extract_flags |
                                 default_extract_flags);

                if (cmd_flags & ~WIMLIB_EXTRACT_MASK_PUBLIC)
                        return WIMLIB_ERR_INVALID_PARAM;

                int cmd_link_flags = (cmd_flags & (WIMLIB_EXTRACT_FLAG_SYMLINK |
                                                   WIMLIB_EXTRACT_FLAG_HARDLINK));
                if (i == 0) {
                        link_flags = cmd_link_flags;
                } else {
                        if (cmd_link_flags != link_flags) {
                                ERROR("The same symlink or hardlink extraction mode "
                                      "must be set on all extraction commands!");
                                return WIMLIB_ERR_INVALID_PARAM;
                        }
                }
                all_flags |= cmd_flags;
        }
        if (all_flags & WIMLIB_EXTRACT_FLAG_GLOB_PATHS) {
                ERROR("Glob paths not supported for wimlib_extract_files(). "
                      "Use wimlib_extract_paths() instead.");
                return WIMLIB_ERR_INVALID_PARAM;
        }

        for (size_t i = 0; i < num_cmds; i++) {
                int extract_flags = (cmds[i].extract_flags |
                                     default_extract_flags);
                const tchar *target = cmds[i].fs_dest_path;
                const tchar *wim_source_path = cmds[i].wim_source_path;

                ret = do_wimlib_extract_paths(wim, image, target,
                                              &wim_source_path, 1,
                                              extract_flags | WIMLIB_EXTRACT_FLAG_FILEMODE,
                                              progress_func);
                if (ret)
                        break;
        }

        clear_lte_extracted_file(wim, all_flags);
        return ret;
}

WIMLIBAPI int
wimlib_extract_paths(WIMStruct *wim, int image, const tchar *target,
                     const tchar * const *paths, size_t num_paths,
                     int extract_flags, wimlib_progress_func_t progress_func)
{
        int ret;

        if (extract_flags & ~WIMLIB_EXTRACT_MASK_PUBLIC)
                return WIMLIB_ERR_INVALID_PARAM;

        ret = do_wimlib_extract_paths(wim, image, target, paths, num_paths,
                                      extract_flags, progress_func);
        clear_lte_extracted_file(wim, extract_flags);
        return ret;
}

WIMLIBAPI int
wimlib_extract_pathlist(WIMStruct *wim, int image, const tchar *target,
                        const tchar *path_list_file, int extract_flags,
                        wimlib_progress_func_t progress_func)
{
        int ret;
        tchar **paths;
        size_t num_paths;
        void *mem;

        ret = read_path_list_file(path_list_file, &paths, &num_paths, &mem);
        if (ret) {
                ERROR("Failed to read path list file \"%"TS"\"",
                      path_list_file);
                return ret;
        }

        ret = wimlib_extract_paths(wim, image, target,
                                   (const tchar * const *)paths, num_paths,
                                   extract_flags, progress_func);
        FREE(paths);
        FREE(mem);
        return ret;
}

WIMLIBAPI int
wimlib_extract_image_from_pipe(int pipe_fd, const tchar *image_num_or_name,
                               const tchar *target, int extract_flags,
                               wimlib_progress_func_t progress_func)
{
        int ret;
        WIMStruct *pwm;
        struct filedes *in_fd;
        int image;
        unsigned i;

        if (extract_flags & ~WIMLIB_EXTRACT_MASK_PUBLIC)
                return WIMLIB_ERR_INVALID_PARAM;

        if (extract_flags & WIMLIB_EXTRACT_FLAG_FILE_ORDER)
                return WIMLIB_ERR_INVALID_PARAM;

        /* Read the WIM header from the pipe and get a WIMStruct to represent
         * the pipable WIM.  Caveats:  Unlike getting a WIMStruct with
         * wimlib_open_wim(), getting a WIMStruct in this way will result in
         * an empty lookup table, no XML data read, and no filename set.  */
        ret = open_wim_as_WIMStruct(&pipe_fd,
                                    WIMLIB_OPEN_FLAG_FROM_PIPE,
                                    &pwm, progress_func);
        if (ret)
                return ret;

        /* Sanity check to make sure this is a pipable WIM.  */
        if (pwm->hdr.magic != PWM_MAGIC) {
                ERROR("The WIM being read from file descriptor %d "
                      "is not pipable!", pipe_fd);
                ret = WIMLIB_ERR_NOT_PIPABLE;
                goto out_wimlib_free;
        }

        /* Sanity check to make sure the first part of a pipable split WIM is
         * sent over the pipe first.  */
        if (pwm->hdr.part_number != 1) {
                ERROR("The first part of the split WIM must be "
                      "sent over the pipe first.");
                ret = WIMLIB_ERR_INVALID_PIPABLE_WIM;
                goto out_wimlib_free;
        }

        in_fd = &pwm->in_fd;
        wimlib_assert(in_fd->offset == WIM_HEADER_DISK_SIZE);

        /* As mentioned, the WIMStruct we created from the pipe does not have
         * XML data yet.  Fix this by reading the extra copy of the XML data
         * that directly follows the header in pipable WIMs.  (Note: see
         * write_pipable_wim() for more details about the format of pipable
         * WIMs.)  */
        {
                struct wim_lookup_table_entry xml_lte;
                struct wim_resource_spec xml_rspec;
                ret = read_pwm_stream_header(pwm, &xml_lte, &xml_rspec, 0, NULL);
                if (ret)
                        goto out_wimlib_free;

                if (!(xml_lte.flags & WIM_RESHDR_FLAG_METADATA))
                {
                        ERROR("Expected XML data, but found non-metadata "
                              "stream.");
                        ret = WIMLIB_ERR_INVALID_PIPABLE_WIM;
                        goto out_wimlib_free;
                }

                wim_res_spec_to_hdr(&xml_rspec, &pwm->hdr.xml_data_reshdr);

                ret = read_wim_xml_data(pwm);
                if (ret)
                        goto out_wimlib_free;

                if (wim_info_get_num_images(pwm->wim_info) != pwm->hdr.image_count) {
                        ERROR("Image count in XML data is not the same as in WIM header.");
                        ret = WIMLIB_ERR_IMAGE_COUNT;
                        goto out_wimlib_free;
                }
        }

        /* Get image index (this may use the XML data that was just read to
         * resolve an image name).  */
        if (image_num_or_name) {
                image = wimlib_resolve_image(pwm, image_num_or_name);
                if (image == WIMLIB_NO_IMAGE) {
                        ERROR("\"%"TS"\" is not a valid image in the pipable WIM!",
                              image_num_or_name);
                        ret = WIMLIB_ERR_INVALID_IMAGE;
                        goto out_wimlib_free;
                } else if (image == WIMLIB_ALL_IMAGES) {
                        ERROR("Applying all images from a pipe is not supported!");
                        ret = WIMLIB_ERR_INVALID_IMAGE;
                        goto out_wimlib_free;
                }
        } else {
                if (pwm->hdr.image_count != 1) {
                        ERROR("No image was specified, but the pipable WIM "
                              "did not contain exactly 1 image");
                        ret = WIMLIB_ERR_INVALID_IMAGE;
                        goto out_wimlib_free;
                }
                image = 1;
        }

        /* Load the needed metadata resource.  */
        for (i = 1; i <= pwm->hdr.image_count; i++) {
                struct wim_lookup_table_entry *metadata_lte;
                struct wim_image_metadata *imd;
                struct wim_resource_spec *metadata_rspec;

                metadata_lte = new_lookup_table_entry();
                if (metadata_lte == NULL) {
                        ret = WIMLIB_ERR_NOMEM;
                        goto out_wimlib_free;
                }
                metadata_rspec = MALLOC(sizeof(struct wim_resource_spec));
                if (metadata_rspec == NULL) {
                        ret = WIMLIB_ERR_NOMEM;
                        free_lookup_table_entry(metadata_lte);
                        goto out_wimlib_free;
                }

                ret = read_pwm_stream_header(pwm, metadata_lte, metadata_rspec, 0, NULL);
                imd = pwm->image_metadata[i - 1];
                imd->metadata_lte = metadata_lte;
                if (ret) {
                        FREE(metadata_rspec);
                        goto out_wimlib_free;
                }

                if (!(metadata_lte->flags & WIM_RESHDR_FLAG_METADATA)) {
                        ERROR("Expected metadata resource, but found "
                              "non-metadata stream.");
                        ret = WIMLIB_ERR_INVALID_PIPABLE_WIM;
                        goto out_wimlib_free;
                }

                if (i == image) {
                        /* Metadata resource is for the image being extracted.
                         * Parse it and save the metadata in memory.  */
                        ret = read_metadata_resource(pwm, imd);
                        if (ret)
                                goto out_wimlib_free;
                        imd->modified = 1;
                } else {
                        /* Metadata resource is not for the image being
                         * extracted.  Skip over it.  */
                        ret = skip_wim_stream(metadata_lte);
                        if (ret)
                                goto out_wimlib_free;
                }
        }
        /* Extract the image.  */
        extract_flags |= WIMLIB_EXTRACT_FLAG_FROM_PIPE;
        ret = do_wimlib_extract_image(pwm, image, target,
                                      extract_flags, progress_func);
        /* Clean up and return.  */
out_wimlib_free:
        wimlib_free(pwm);
        return ret;
}

WIMLIBAPI int
wimlib_extract_image(WIMStruct *wim, int image, const tchar *target,
                     int extract_flags, wimlib_progress_func_t progress_func)
{
        if (extract_flags & ~WIMLIB_EXTRACT_MASK_PUBLIC)
                return WIMLIB_ERR_INVALID_PARAM;
        return do_wimlib_extract_image(wim, image, target, extract_flags,
                                       progress_func);
}