[wimlib] / src / win32.c

/*
 * win32.c
 *
 * All the library code specific to native Windows builds is in here.
 */

/*
 * Copyright (C) 2013 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/.
 */

#ifdef __WIN32__

#include "config.h"
#include <windows.h>
#include <ntdef.h>
#include <wchar.h>
#include <shlwapi.h> /* for PathMatchSpecW() */
#include <aclapi.h> /* for SetSecurityInfo() */
#ifdef ERROR /* windows.h defines this */
#  undef ERROR
#endif

#include "win32.h"
#include "dentry.h"
#include "lookup_table.h"
#include "security.h"
#include "endianness.h"
#include "buffer_io.h"
#include <pthread.h>

#include <errno.h>

#define MAX_GET_SD_ACCESS_DENIED_WARNINGS 1
#define MAX_GET_SACL_PRIV_NOTHELD_WARNINGS 1
#define MAX_CREATE_HARD_LINK_WARNINGS 5
struct win32_capture_state {
        unsigned long num_get_sd_access_denied;
        unsigned long num_get_sacl_priv_notheld;
};

#define MAX_SET_SD_ACCESS_DENIED_WARNINGS 1
#define MAX_SET_SACL_PRIV_NOTHELD_WARNINGS 1

#ifdef ENABLE_ERROR_MESSAGES
static void
win32_error(u32 err_code)
{
        wchar_t *buffer;
        DWORD nchars;
        nchars = FormatMessageW(FORMAT_MESSAGE_FROM_SYSTEM |
                                    FORMAT_MESSAGE_ALLOCATE_BUFFER,
                                NULL, err_code, 0,
                                (wchar_t*)&buffer, 0, NULL);
        if (nchars == 0) {
                ERROR("Error printing error message! "
                      "Computer will self-destruct in 3 seconds.");
        } else {
                ERROR("Win32 error: %ls", buffer);
                LocalFree(buffer);
        }
}
#else /* ENABLE_ERROR_MESSAGES */
#  define win32_error(err_code)
#endif /* !ENABLE_ERROR_MESSAGES */

/* Pointers to functions that are not available on all targetted versions of
 * Windows (XP and later).  NOTE: The WINAPI annotations seem to be important; I
 * assume it specifies a certain calling convention. */

/* Vista and later */
static HANDLE (WINAPI *win32func_FindFirstStreamW)(LPCWSTR lpFileName,
                                            STREAM_INFO_LEVELS InfoLevel,
                                            LPVOID lpFindStreamData,
                                            DWORD dwFlags) = NULL;

/* Vista and later */
static BOOL (WINAPI *win32func_FindNextStreamW)(HANDLE hFindStream,
                                         LPVOID lpFindStreamData) = NULL;

static HMODULE hKernel32 = NULL;

/* Try to dynamically load some functions */
void
win32_global_init()
{
        DWORD err;

        if (hKernel32 == NULL) {
                DEBUG("Loading Kernel32.dll");
                hKernel32 = LoadLibraryW(L"Kernel32.dll");
                if (hKernel32 == NULL) {
                        err = GetLastError();
                        WARNING("Can't load Kernel32.dll");
                        win32_error(err);
                        return;
                }
        }

        DEBUG("Looking for FindFirstStreamW");
        win32func_FindFirstStreamW = (void*)GetProcAddress(hKernel32, "FindFirstStreamW");
        if (!win32func_FindFirstStreamW) {
                WARNING("Could not find function FindFirstStreamW() in Kernel32.dll!");
                WARNING("Capturing alternate data streams will not be supported.");
                return;
        }

        DEBUG("Looking for FindNextStreamW");
        win32func_FindNextStreamW = (void*)GetProcAddress(hKernel32, "FindNextStreamW");
        if (!win32func_FindNextStreamW) {
                WARNING("Could not find function FindNextStreamW() in Kernel32.dll!");
                WARNING("Capturing alternate data streams will not be supported.");
                win32func_FindFirstStreamW = NULL;
        }
}

void
win32_global_cleanup()
{
        if (hKernel32 != NULL) {
                DEBUG("Closing Kernel32.dll");
                FreeLibrary(hKernel32);
                hKernel32 = NULL;
        }
}

static const wchar_t *capture_access_denied_msg =
L"         If you are not running this program as the administrator, you may\n"
 "         need to do so, so that all data and metadata can be backed up.\n"
 "         Otherwise, there may be no way to access the desired data or\n"
 "         metadata without taking ownership of the file or directory.\n"
 ;

static const wchar_t *apply_access_denied_msg =
L"If you are not running this program as the administrator, you may\n"
 "          need to do so, so that all data and metadata can be extracted\n"
 "          exactly as the origignal copy.  However, if you do not care that\n"
 "          the security descriptors are extracted correctly, you could run\n"
 "          `wimlib-imagex apply' with the --no-acls flag instead.\n"
 ;

static HANDLE
win32_open_existing_file(const wchar_t *path, DWORD dwDesiredAccess)
{
        return CreateFileW(path,
                           dwDesiredAccess,
                           FILE_SHARE_READ,
                           NULL, /* lpSecurityAttributes */
                           OPEN_EXISTING,
                           FILE_FLAG_BACKUP_SEMANTICS |
                               FILE_FLAG_OPEN_REPARSE_POINT,
                           NULL /* hTemplateFile */);
}

HANDLE
win32_open_file_data_only(const wchar_t *path)
{
        return win32_open_existing_file(path, FILE_READ_DATA);
}

int
read_win32_file_prefix(const struct wim_lookup_table_entry *lte,
                       u64 size,
                       consume_data_callback_t cb,
                       void *ctx_or_buf,
                       int _ignored_flags)
{
        int ret = 0;
        void *out_buf;
        DWORD err;
        u64 bytes_remaining;

        HANDLE hFile = win32_open_file_data_only(lte->file_on_disk);
        if (hFile == INVALID_HANDLE_VALUE) {
                err = GetLastError();
                ERROR("Failed to open \"%ls\"", lte->file_on_disk);
                win32_error(err);
                return WIMLIB_ERR_OPEN;
        }

        if (cb)
                out_buf = alloca(WIM_CHUNK_SIZE);
        else
                out_buf = ctx_or_buf;

        bytes_remaining = size;
        while (bytes_remaining) {
                DWORD bytesToRead, bytesRead;

                bytesToRead = min(WIM_CHUNK_SIZE, bytes_remaining);
                if (!ReadFile(hFile, out_buf, bytesToRead, &bytesRead, NULL) ||
                    bytesRead != bytesToRead)
                {
                        err = GetLastError();
                        ERROR("Failed to read data from \"%ls\"", lte->file_on_disk);
                        win32_error(err);
                        ret = WIMLIB_ERR_READ;
                        break;
                }
                bytes_remaining -= bytesRead;
                if (cb) {
                        ret = (*cb)(out_buf, bytesRead, ctx_or_buf);
                        if (ret)
                                break;
                } else {
                        out_buf += bytesRead;
                }
        }
        CloseHandle(hFile);
        return ret;
}

struct win32_encrypted_read_ctx {
        consume_data_callback_t read_prefix_cb;
        void *read_prefix_ctx_or_buf;
        int wimlib_err_code;
        void *buf;
        size_t buf_filled;
        u64 bytes_remaining;
};

static DWORD WINAPI
win32_encrypted_export_cb(unsigned char *_data, void *_ctx, unsigned long len)
{
        const void *data = _data;
        struct win32_encrypted_read_ctx *ctx = _ctx;
        int ret;

        DEBUG("len = %lu", len);
        if (ctx->read_prefix_cb) {
                /* The length of the buffer passed to the ReadEncryptedFileRaw()
                 * export callback is undocumented, so we assume it may be of
                 * arbitrary size. */
                size_t bytes_to_buffer = min(ctx->bytes_remaining - ctx->buf_filled,
                                             len);
                while (bytes_to_buffer) {
                        size_t bytes_to_copy_to_buf =
                                min(bytes_to_buffer, WIM_CHUNK_SIZE - ctx->buf_filled);

                        memcpy(ctx->buf + ctx->buf_filled, data,
                               bytes_to_copy_to_buf);
                        ctx->buf_filled += bytes_to_copy_to_buf;
                        data += bytes_to_copy_to_buf;
                        bytes_to_buffer -= bytes_to_copy_to_buf;

                        if (ctx->buf_filled == WIM_CHUNK_SIZE ||
                            ctx->buf_filled == ctx->bytes_remaining)
                        {
                                ret = (*ctx->read_prefix_cb)(ctx->buf,
                                                             ctx->buf_filled,
                                                             ctx->read_prefix_ctx_or_buf);
                                if (ret) {
                                        ctx->wimlib_err_code = ret;
                                        /* Shouldn't matter what error code is returned
                                         * here, as long as it isn't ERROR_SUCCESS. */
                                        return ERROR_READ_FAULT;
                                }
                                ctx->bytes_remaining -= ctx->buf_filled;
                                ctx->buf_filled = 0;
                        }
                }
        } else {
                size_t len_to_copy = min(len, ctx->bytes_remaining);
                memcpy(ctx->read_prefix_ctx_or_buf, data, len_to_copy);
                ctx->bytes_remaining -= len_to_copy;
                ctx->read_prefix_ctx_or_buf += len_to_copy;
        }
        return ERROR_SUCCESS;
}

int
read_win32_encrypted_file_prefix(const struct wim_lookup_table_entry *lte,
                                 u64 size,
                                 consume_data_callback_t cb,
                                 void *ctx_or_buf,
                                 int _ignored_flags)
{
        struct win32_encrypted_read_ctx export_ctx;
        DWORD err;
        void *file_ctx;
        int ret;

        DEBUG("Reading %"PRIu64" bytes from encryted file \"%ls\"",
              size, lte->file_on_disk);

        export_ctx.read_prefix_cb = cb;
        export_ctx.read_prefix_ctx_or_buf = ctx_or_buf;
        export_ctx.wimlib_err_code = 0;
        if (cb) {
                export_ctx.buf = MALLOC(WIM_CHUNK_SIZE);
                if (!export_ctx.buf)
                        return WIMLIB_ERR_NOMEM;
        } else {
                export_ctx.buf = NULL;
        }
        export_ctx.buf_filled = 0;
        export_ctx.bytes_remaining = size;

        err = OpenEncryptedFileRawW(lte->file_on_disk, 0, &file_ctx);
        if (err != ERROR_SUCCESS) {
                ERROR("Failed to open encrypted file \"%ls\" for raw read",
                      lte->file_on_disk);
                win32_error(err);
                ret = WIMLIB_ERR_OPEN;
                goto out_free_buf;
        }
        err = ReadEncryptedFileRaw(win32_encrypted_export_cb,
                                   &export_ctx, file_ctx);
        if (err != ERROR_SUCCESS) {
                ERROR("Failed to read encrypted file \"%ls\"",
                      lte->file_on_disk);
                win32_error(err);
                ret = export_ctx.wimlib_err_code;
                if (ret == 0)
                        ret = WIMLIB_ERR_READ;
        } else if (export_ctx.bytes_remaining != 0) {
                ERROR("Only could read %"PRIu64" of %"PRIu64" bytes from "
                      "encryted file \"%ls\"",
                      size - export_ctx.bytes_remaining, size,
                      lte->file_on_disk);
                ret = WIMLIB_ERR_READ;
        } else {
                ret = 0;
        }
        CloseEncryptedFileRaw(file_ctx);
out_free_buf:
        FREE(export_ctx.buf);
        return ret;
}

/* Given a path, which may not yet exist, get a set of flags that describe the
 * features of the volume the path is on. */
static int
win32_get_vol_flags(const wchar_t *path, unsigned *vol_flags_ret)
{
        wchar_t *volume;
        BOOL bret;
        DWORD vol_flags;

        if (path[0] != L'\0' && path[0] != L'\\' &&
            path[0] != L'/' && path[1] == L':')
        {
                /* Path starts with a drive letter; use it. */
                volume = alloca(4 * sizeof(wchar_t));
                volume[0] = path[0];
                volume[1] = path[1];
                volume[2] = L'\\';
                volume[3] = L'\0';
        } else {
                /* Path does not start with a drive letter; use the volume of
                 * the current working directory. */
                volume = NULL;
        }
        bret = GetVolumeInformationW(volume, /* lpRootPathName */
                                     NULL,  /* lpVolumeNameBuffer */
                                     0,     /* nVolumeNameSize */
                                     NULL,  /* lpVolumeSerialNumber */
                                     NULL,  /* lpMaximumComponentLength */
                                     &vol_flags, /* lpFileSystemFlags */
                                     NULL,  /* lpFileSystemNameBuffer */
                                     0);    /* nFileSystemNameSize */
        if (!bret) {
                DWORD err = GetLastError();
                WARNING("Failed to get volume information for path \"%ls\"", path);
                win32_error(err);
                vol_flags = 0xffffffff;
        }

        DEBUG("using vol_flags = %x", vol_flags);
        *vol_flags_ret = vol_flags;
        return 0;
}


static u64
FILETIME_to_u64(const FILETIME *ft)
{
        return ((u64)ft->dwHighDateTime << 32) | (u64)ft->dwLowDateTime;
}

static int
win32_get_short_name(struct wim_dentry *dentry, const wchar_t *path)
{
        WIN32_FIND_DATAW dat;
        HANDLE hFind;
        int ret = 0;

        /* If we can't read the short filename for some reason, we just ignore
         * the error and assume the file has no short name.  I don't think this
         * should be an issue, since the short names are essentially obsolete
         * anyway. */
        hFind = FindFirstFileW(path, &dat);
        if (hFind != INVALID_HANDLE_VALUE) {
                if (dat.cAlternateFileName[0] != L'\0') {
                        DEBUG("\"%ls\": short name \"%ls\"", path, dat.cAlternateFileName);
                        size_t short_name_nbytes = wcslen(dat.cAlternateFileName) *
                                                   sizeof(wchar_t);
                        size_t n = short_name_nbytes + sizeof(wchar_t);
                        dentry->short_name = MALLOC(n);
                        if (dentry->short_name) {
                                memcpy(dentry->short_name, dat.cAlternateFileName, n);
                                dentry->short_name_nbytes = short_name_nbytes;
                        } else {
                                ret = WIMLIB_ERR_NOMEM;
                        }
                }
                FindClose(hFind);
        }
        return ret;
}

static int
win32_get_security_descriptor(struct wim_dentry *dentry,
                              struct sd_set *sd_set,
                              const wchar_t *path,
                              struct win32_capture_state *state,
                              int add_image_flags)
{
        SECURITY_INFORMATION requestedInformation;
        DWORD lenNeeded = 0;
        BOOL status;
        DWORD err;
        unsigned long n;

        requestedInformation = DACL_SECURITY_INFORMATION |
                               SACL_SECURITY_INFORMATION |
                               OWNER_SECURITY_INFORMATION |
                               GROUP_SECURITY_INFORMATION;
again:
        /* Request length of security descriptor */
        status = GetFileSecurityW(path, requestedInformation,
                                  NULL, 0, &lenNeeded);
        err = GetLastError();
        if (!status && err == ERROR_INSUFFICIENT_BUFFER) {
                DWORD len = lenNeeded;
                char buf[len];
                if (GetFileSecurityW(path, requestedInformation,
                                     (PSECURITY_DESCRIPTOR)buf, len, &lenNeeded))
                {
                        int security_id = sd_set_add_sd(sd_set, buf, len);
                        if (security_id < 0)
                                return WIMLIB_ERR_NOMEM;
                        else {
                                dentry->d_inode->i_security_id = security_id;
                                return 0;
                        }
                } else {
                        err = GetLastError();
                }
        }

        if (add_image_flags & WIMLIB_ADD_IMAGE_FLAG_STRICT_ACLS)
                goto fail;

        switch (err) {
        case ERROR_PRIVILEGE_NOT_HELD:
                if (requestedInformation & SACL_SECURITY_INFORMATION) {
                        n = state->num_get_sacl_priv_notheld++;
                        requestedInformation &= ~SACL_SECURITY_INFORMATION;
                        if (n < MAX_GET_SACL_PRIV_NOTHELD_WARNINGS) {
                                WARNING(
"We don't have enough privileges to read the full security\n"
"          descriptor of \"%ls\"!\n"
"          Re-trying with SACL omitted.\n", path);
                        } else if (n == MAX_GET_SACL_PRIV_NOTHELD_WARNINGS) {
                                WARNING(
"Suppressing further privileges not held error messages when reading\n"
"          security descriptors.");
                        }
                        goto again;
                }
                /* Fall through */
        case ERROR_ACCESS_DENIED:
                n = state->num_get_sd_access_denied++;
                if (n < MAX_GET_SD_ACCESS_DENIED_WARNINGS) {
                        WARNING("Failed to read security descriptor of \"%ls\": "
                                "Access denied!\n%ls", path, capture_access_denied_msg);
                } else if (n == MAX_GET_SD_ACCESS_DENIED_WARNINGS) {
                        WARNING("Suppressing further access denied errors messages i"
                                "when reading security descriptors");
                }
                return 0;
        default:
fail:
                ERROR("Failed to read security descriptor of \"%ls\"", path);
                win32_error(err);
                return WIMLIB_ERR_READ;
        }
}

static int
win32_build_dentry_tree_recursive(struct wim_dentry **root_ret,
                                  wchar_t *path,
                                  size_t path_num_chars,
                                  struct add_image_params *params,
                                  struct win32_capture_state *state,
                                  unsigned vol_flags);

/* Reads the directory entries of directory using a Win32 API and recursively
 * calls win32_build_dentry_tree() on them. */
static int
win32_recurse_directory(struct wim_dentry *root,
                        wchar_t *dir_path,
                        size_t dir_path_num_chars,
                        struct add_image_params *params,
                        struct win32_capture_state *state,
                        unsigned vol_flags)
{
        WIN32_FIND_DATAW dat;
        HANDLE hFind;
        DWORD err;
        int ret;

        DEBUG("Recurse to directory \"%ls\"", dir_path);

        /* Begin reading the directory by calling FindFirstFileW.  Unlike UNIX
         * opendir(), FindFirstFileW has file globbing built into it.  But this
         * isn't what we actually want, so just add a dummy glob to get all
         * entries. */
        dir_path[dir_path_num_chars] = L'/';
        dir_path[dir_path_num_chars + 1] = L'*';
        dir_path[dir_path_num_chars + 2] = L'\0';
        hFind = FindFirstFileW(dir_path, &dat);
        dir_path[dir_path_num_chars] = L'\0';

        if (hFind == INVALID_HANDLE_VALUE) {
                err = GetLastError();
                if (err == ERROR_FILE_NOT_FOUND) {
                        return 0;
                } else {
                        ERROR("Failed to read directory \"%ls\"", dir_path);
                        win32_error(err);
                        return WIMLIB_ERR_READ;
                }
        }
        ret = 0;
        do {
                /* Skip . and .. entries */
                if (dat.cFileName[0] == L'.' &&
                    (dat.cFileName[1] == L'\0' ||
                     (dat.cFileName[1] == L'.' &&
                      dat.cFileName[2] == L'\0')))
                        continue;
                size_t filename_len = wcslen(dat.cFileName);

                dir_path[dir_path_num_chars] = L'/';
                wmemcpy(dir_path + dir_path_num_chars + 1,
                        dat.cFileName,
                        filename_len + 1);

                struct wim_dentry *child;
                size_t path_len = dir_path_num_chars + 1 + filename_len;
                ret = win32_build_dentry_tree_recursive(&child,
                                                        dir_path,
                                                        path_len,
                                                        params,
                                                        state,
                                                        vol_flags);
                dir_path[dir_path_num_chars] = L'\0';
                if (ret)
                        goto out_find_close;
                if (child)
                        dentry_add_child(root, child);
        } while (FindNextFileW(hFind, &dat));
        err = GetLastError();
        if (err != ERROR_NO_MORE_FILES) {
                ERROR("Failed to read directory \"%ls\"", dir_path);
                win32_error(err);
                if (ret == 0)
                        ret = WIMLIB_ERR_READ;
        }
out_find_close:
        FindClose(hFind);
        return ret;
}

int
win32_get_file_and_vol_ids(const wchar_t *path, u64 *ino_ret, u64 *dev_ret)
{
        HANDLE hFile;
        DWORD err;
        BY_HANDLE_FILE_INFORMATION file_info;
        int ret;

        hFile = win32_open_existing_file(path, FILE_READ_ATTRIBUTES);
        if (hFile == INVALID_HANDLE_VALUE) {
                err = GetLastError();
                if (err != ERROR_FILE_NOT_FOUND) {
                        WARNING("Failed to open \"%ls\" to get file "
                                "and volume IDs", path);
                        win32_error(err);
                }
                return WIMLIB_ERR_OPEN;
        }

        if (!GetFileInformationByHandle(hFile, &file_info)) {
                err = GetLastError();
                ERROR("Failed to get file information for \"%ls\"", path);
                win32_error(err);
                ret = WIMLIB_ERR_STAT;
        } else {
                *ino_ret = ((u64)file_info.nFileIndexHigh << 32) |
                            (u64)file_info.nFileIndexLow;
                *dev_ret = file_info.dwVolumeSerialNumber;
                ret = 0;
        }
        CloseHandle(hFile);
        return ret;
}

/* Reparse point fixup status code */
enum rp_status {
        /* Reparse point corresponded to an absolute symbolic link or junction
         * point that pointed outside the directory tree being captured, and
         * therefore was excluded. */
        RP_EXCLUDED       = 0x0,

        /* Reparse point was not fixed as it was either a relative symbolic
         * link, a mount point, or something else we could not understand. */
        RP_NOT_FIXED      = 0x1,

        /* Reparse point corresponded to an absolute symbolic link or junction
         * point that pointed inside the directory tree being captured, where
         * the target was specified by a "full" \??\ prefixed path, and
         * therefore was fixed to be relative to the root of the directory tree
         * being captured. */
        RP_FIXED_FULLPATH = 0x2,

        /* Same as RP_FIXED_FULLPATH, except the absolute link target did not
         * have the \??\ prefix.  It may have begun with a drive letter though.
         * */
        RP_FIXED_ABSPATH  = 0x4,

        /* Either RP_FIXED_FULLPATH or RP_FIXED_ABSPATH. */
        RP_FIXED          = RP_FIXED_FULLPATH | RP_FIXED_ABSPATH,
};

/* Given the "substitute name" target of a Windows reparse point, try doing a
 * fixup where we change it to be absolute relative to the root of the directory
 * tree being captured.
 *
 * Note that this is only executed when WIMLIB_ADD_IMAGE_FLAG_RPFIX has been
 * set.
 *
 * @capture_root_ino and @capture_root_dev indicate the inode number and device
 * of the root of the directory tree being captured.  They are meant to identify
 * this directory (as an alternative to its actual path, which could potentially
 * be reached via multiple destinations due to other symbolic links).  This may
 * not work properly on FAT, which doesn't seem to supply proper inode numbers
 * or file IDs.  However, FAT doesn't support reparse points so this function
 * wouldn't even be called anyway.
 */
static enum rp_status
win32_capture_maybe_rpfix_target(wchar_t *target, u16 *target_nbytes_p,
                                 u64 capture_root_ino, u64 capture_root_dev,
                                 u32 rptag)
{
        u16 target_nchars = *target_nbytes_p / 2;
        size_t stripped_chars;
        wchar_t *orig_target;
        int ret;

        ret = parse_substitute_name(target, *target_nbytes_p, rptag);
        if (ret < 0)
                return RP_NOT_FIXED;
        stripped_chars = ret;
        if (stripped_chars)
                stripped_chars -= 2;
        target[target_nchars] = L'\0';
        orig_target = target;
        target = capture_fixup_absolute_symlink(target + stripped_chars,
                                                capture_root_ino, capture_root_dev);
        if (!target)
                return RP_EXCLUDED;
        target_nchars = wcslen(target);
        wmemmove(orig_target + stripped_chars, target, target_nchars + 1);
        *target_nbytes_p = (target_nchars + stripped_chars) * sizeof(wchar_t);
        DEBUG("Fixed reparse point (new target: \"%ls\")", orig_target);
        if (stripped_chars)
                return RP_FIXED_FULLPATH;
        else
                return RP_FIXED_ABSPATH;
}

/* Returns: `enum rp_status' value on success; negative WIMLIB_ERR_* value on
 * failure. */
static int
win32_capture_try_rpfix(u8 *rpbuf, u16 *rpbuflen_p,
                        u64 capture_root_ino, u64 capture_root_dev,
                        const wchar_t *path)
{
        struct reparse_data rpdata;
        DWORD rpbuflen;
        int ret;
        enum rp_status rp_status;

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

        rp_status = win32_capture_maybe_rpfix_target(rpdata.substitute_name,
                                                     &rpdata.substitute_name_nbytes,
                                                     capture_root_ino,
                                                     capture_root_dev,
                                                     le32_to_cpu(*(u32*)rpbuf));
        if (rp_status & RP_FIXED) {
                wimlib_assert(rpdata.substitute_name_nbytes % 2 == 0);
                utf16lechar substitute_name_copy[rpdata.substitute_name_nbytes / 2];
                wmemcpy(substitute_name_copy, rpdata.substitute_name,
                        rpdata.substitute_name_nbytes / 2);
                rpdata.substitute_name = substitute_name_copy;
                rpdata.print_name = substitute_name_copy;
                rpdata.print_name_nbytes = rpdata.substitute_name_nbytes;
                if (rp_status == RP_FIXED_FULLPATH) {
                        /* "full path", meaning \??\ prefixed.  We should not
                         * include this prefix in the print name, as it is
                         * apparently meant for the filesystem driver only. */
                        rpdata.print_name += 4;
                        rpdata.print_name_nbytes -= 8;
                }
                ret = make_reparse_buffer(&rpdata, rpbuf);
                if (ret == 0)
                        ret = rp_status;
                else
                        ret = -ret;
        } else {
                if (ret == RP_EXCLUDED) {
                        size_t print_name_nchars = rpdata.print_name_nbytes / 2;
                        wchar_t print_name0[print_name_nchars + 1];
                        print_name0[print_name_nchars] = L'\0';
                        wmemcpy(print_name0, rpdata.print_name, print_name_nchars);
                        WARNING("Ignoring %ls pointing out of capture directory:\n"
                                "          \"%ls\" -> \"%ls\"\n"
                                "          (Use --norpfix to capture all symbolic links "
                                "and junction points as-is)",
                                (rpdata.rptag == WIM_IO_REPARSE_TAG_SYMLINK) ?
                                        L"absolute symbolic link" : L"junction point",
                                path, print_name0);
                }
                ret = rp_status;
        }
        return ret;
}

/*
 * Loads the reparse point data from a reparse point into memory, optionally
 * fixing the targets of absolute symbolic links and junction points to be
 * relative to the root of capture.
 *
 * @hFile:  Open handle to the reparse point.
 * @path:   Path to the reparse point.  Used for error messages only.
 * @params: Additional parameters, including whether to do reparse point fixups
 *          or not.
 * @rpbuf:  Buffer of length at least REPARSE_POINT_MAX_SIZE bytes into which
 *          the reparse point buffer will be loaded.
 * @rpbuflen_ret:  On success, the length of the reparse point buffer in bytes
 *                 is written to this location.
 *
 * Returns:
 *      On success, returns an `enum rp_status' value that indicates if and/or
 *      how the reparse point fixup was done.
 *
 *      On failure, returns a negative value that is a negated WIMLIB_ERR_*
 *      code.
 */
static int
win32_get_reparse_data(HANDLE hFile, const wchar_t *path,
                       struct add_image_params *params,
                       u8 *rpbuf, u16 *rpbuflen_ret)
{
        DWORD bytesReturned;
        u32 reparse_tag;
        int ret;
        u16 rpbuflen;

        DEBUG("Loading reparse data from \"%ls\"", path);
        if (!DeviceIoControl(hFile, FSCTL_GET_REPARSE_POINT,
                             NULL, /* "Not used with this operation; set to NULL" */
                             0, /* "Not used with this operation; set to 0" */
                             rpbuf, /* "A pointer to a buffer that
                                                   receives the reparse point data */
                             REPARSE_POINT_MAX_SIZE, /* "The size of the output
                                                        buffer, in bytes */
                             &bytesReturned,
                             NULL))
        {
                DWORD err = GetLastError();
                ERROR("Failed to get reparse data of \"%ls\"", path);
                win32_error(err);
                return -WIMLIB_ERR_READ;
        }
        if (bytesReturned < 8 || bytesReturned > REPARSE_POINT_MAX_SIZE) {
                ERROR("Reparse data on \"%ls\" is invalid", path);
                return -WIMLIB_ERR_INVALID_REPARSE_DATA;
        }

        rpbuflen = bytesReturned;
        reparse_tag = le32_to_cpu(*(u32*)rpbuf);
        if (params->add_image_flags & WIMLIB_ADD_IMAGE_FLAG_RPFIX &&
            (reparse_tag == WIM_IO_REPARSE_TAG_SYMLINK ||
             reparse_tag == WIM_IO_REPARSE_TAG_MOUNT_POINT))
        {
                /* Try doing reparse point fixup */
                ret = win32_capture_try_rpfix(rpbuf,
                                              &rpbuflen,
                                              params->capture_root_ino,
                                              params->capture_root_dev,
                                              path);
        } else {
                ret = RP_NOT_FIXED;
        }
        *rpbuflen_ret = rpbuflen;
        return ret;
}

static DWORD WINAPI
win32_tally_encrypted_size_cb(unsigned char *_data, void *_ctx,
                              unsigned long len)
{
        *(u64*)_ctx += len;
        return ERROR_SUCCESS;
}

static int
win32_get_encrypted_file_size(const wchar_t *path, u64 *size_ret)
{
        DWORD err;
        void *file_ctx;
        int ret;

        *size_ret = 0;
        err = OpenEncryptedFileRawW(path, 0, &file_ctx);
        if (err != ERROR_SUCCESS) {
                ERROR("Failed to open encrypted file \"%ls\" for raw read", path);
                win32_error(err);
                return WIMLIB_ERR_OPEN;
        }
        err = ReadEncryptedFileRaw(win32_tally_encrypted_size_cb,
                                   size_ret, file_ctx);
        if (err != ERROR_SUCCESS) {
                ERROR("Failed to read raw encrypted data from \"%ls\"", path);
                win32_error(err);
                ret = WIMLIB_ERR_READ;
        } else {
                ret = 0;
        }
        CloseEncryptedFileRaw(file_ctx);
        return ret;
}

/* Scans an unnamed or named stream of a Win32 file (not a reparse point
 * stream); calculates its SHA1 message digest and either creates a `struct
 * wim_lookup_table_entry' in memory for it, or uses an existing 'struct
 * wim_lookup_table_entry' for an identical stream.
 *
 * @path:               Path to the file (UTF-16LE).
 *
 * @path_num_chars:     Number of 2-byte characters in @path.
 *
 * @inode:              WIM inode to save the stream into.
 *
 * @lookup_table:       Stream lookup table for the WIM.
 *
 * @dat:                A `WIN32_FIND_STREAM_DATA' structure that specifies the
 *                      stream name.
 *
 * Returns 0 on success; nonzero on failure.
 */
static int
win32_capture_stream(const wchar_t *path,
                     size_t path_num_chars,
                     struct wim_inode *inode,
                     struct wim_lookup_table *lookup_table,
                     WIN32_FIND_STREAM_DATA *dat)
{
        struct wim_ads_entry *ads_entry;
        struct wim_lookup_table_entry *lte;
        int ret;
        wchar_t *stream_name, *colon;
        size_t stream_name_nchars;
        bool is_named_stream;
        wchar_t *spath;
        size_t spath_nchars;
        size_t spath_buf_nbytes;
        const wchar_t *relpath_prefix;
        const wchar_t *colonchar;

        DEBUG("Capture \"%ls\" stream \"%ls\"", path, dat->cStreamName);

        /* The stream name should be returned as :NAME:TYPE */
        stream_name = dat->cStreamName;
        if (*stream_name != L':')
                goto out_invalid_stream_name;
        stream_name += 1;
        colon = wcschr(stream_name, L':');
        if (colon == NULL)
                goto out_invalid_stream_name;

        if (wcscmp(colon + 1, L"$DATA")) {
                /* Not a DATA stream */
                ret = 0;
                goto out;
        }

        *colon = '\0';

        stream_name_nchars = colon - stream_name;
        is_named_stream = (stream_name_nchars != 0);

        if (is_named_stream) {
                /* Allocate an ADS entry for the named stream. */
                ads_entry = inode_add_ads_utf16le(inode, stream_name,
                                                  stream_name_nchars * sizeof(wchar_t));
                if (!ads_entry) {
                        ret = WIMLIB_ERR_NOMEM;
                        goto out;
                }
        }

        /* If zero length stream, no lookup table entry needed. */
        if ((u64)dat->StreamSize.QuadPart == 0) {
                ret = 0;
                goto out;
        }

        /* Create a UTF-16LE string @spath that gives the filename, then a
         * colon, then the stream name.  Or, if it's an unnamed stream, just the
         * filename.  It is MALLOC()'ed so that it can be saved in the
         * wim_lookup_table_entry if needed.
         *
         * As yet another special case, relative paths need to be changed to
         * begin with an explicit "./" so that, for example, a file t:ads, where
         * :ads is the part we added, is not interpreted as a file on the t:
         * drive. */
        spath_nchars = path_num_chars;
        relpath_prefix = L"";
        colonchar = L"";
        if (is_named_stream) {
                spath_nchars += 1 + stream_name_nchars;
                colonchar = L":";
                if (path_num_chars == 1 &&
                    path[0] != L'/' &&
                    path[0] != L'\\')
                {
                        spath_nchars += 2;
                        relpath_prefix = L"./";
                }
        }

        spath_buf_nbytes = (spath_nchars + 1) * sizeof(wchar_t);
        spath = MALLOC(spath_buf_nbytes);

        swprintf(spath, L"%ls%ls%ls%ls",
                 relpath_prefix, path, colonchar, stream_name);

        /* Make a new wim_lookup_table_entry */
        lte = new_lookup_table_entry();
        if (!lte) {
                ret = WIMLIB_ERR_NOMEM;
                goto out_free_spath;
        }
        lte->file_on_disk = spath;
        spath = NULL;
        if (inode->i_attributes & FILE_ATTRIBUTE_ENCRYPTED && !is_named_stream) {
                u64 encrypted_size;
                lte->resource_location = RESOURCE_WIN32_ENCRYPTED;
                ret = win32_get_encrypted_file_size(path, &encrypted_size);
                if (ret)
                        goto out_free_spath;
                lte->resource_entry.original_size = encrypted_size;
        } else {
                lte->resource_location = RESOURCE_WIN32;
                lte->resource_entry.original_size = (u64)dat->StreamSize.QuadPart;
        }

        u32 stream_id;
        if (is_named_stream) {
                stream_id = ads_entry->stream_id;
                ads_entry->lte = lte;
        } else {
                stream_id = 0;
                inode->i_lte = lte;
        }
        lookup_table_insert_unhashed(lookup_table, lte, inode, stream_id);
        ret = 0;
out_free_spath:
        FREE(spath);
out:
        return ret;
out_invalid_stream_name:
        ERROR("Invalid stream name: \"%ls:%ls\"", path, dat->cStreamName);
        ret = WIMLIB_ERR_READ;
        goto out;
}

/* Scans a Win32 file for unnamed and named data streams (not reparse point
 * streams).
 *
 * @path:               Path to the file (UTF-16LE).
 *
 * @path_num_chars:     Number of 2-byte characters in @path.
 *
 * @inode:              WIM inode to save the stream into.
 *
 * @lookup_table:       Stream lookup table for the WIM.
 *
 * @file_size:          Size of unnamed data stream.  (Used only if alternate
 *                      data streams API appears to be unavailable.)
 *
 * @vol_flags:          Flags that specify features of the volume being
 *                      captured.
 *
 * Returns 0 on success; nonzero on failure.
 */
static int
win32_capture_streams(const wchar_t *path,
                      size_t path_num_chars,
                      struct wim_inode *inode,
                      struct wim_lookup_table *lookup_table,
                      u64 file_size,
                      unsigned vol_flags)
{
        WIN32_FIND_STREAM_DATA dat;
        int ret;
        HANDLE hFind;
        DWORD err;

        DEBUG("Capturing streams from \"%ls\"", path);

        if (win32func_FindFirstStreamW == NULL ||
            !(vol_flags & FILE_NAMED_STREAMS))
                goto unnamed_only;

        hFind = win32func_FindFirstStreamW(path, FindStreamInfoStandard, &dat, 0);
        if (hFind == INVALID_HANDLE_VALUE) {
                err = GetLastError();
                if (err == ERROR_CALL_NOT_IMPLEMENTED)
                        goto unnamed_only;

                /* Seems legal for this to return ERROR_HANDLE_EOF on reparse
                 * points and directories */
                if ((inode->i_attributes &
                    (FILE_ATTRIBUTE_REPARSE_POINT | FILE_ATTRIBUTE_DIRECTORY))
                    && err == ERROR_HANDLE_EOF)
                {
                        DEBUG("ERROR_HANDLE_EOF (ok)");
                        return 0;
                } else {
                        if (err == ERROR_ACCESS_DENIED) {
                                WARNING("Failed to look up data streams "
                                        "of \"%ls\": Access denied!\n%ls",
                                        path, capture_access_denied_msg);
                                return 0;
                        } else {
                                ERROR("Failed to look up data streams "
                                      "of \"%ls\"", path);
                                win32_error(err);
                                return WIMLIB_ERR_READ;
                        }
                }
        }
        do {
                ret = win32_capture_stream(path,
                                           path_num_chars,
                                           inode, lookup_table,
                                           &dat);
                if (ret)
                        goto out_find_close;
        } while (win32func_FindNextStreamW(hFind, &dat));
        err = GetLastError();
        if (err != ERROR_HANDLE_EOF) {
                ERROR("Win32 API: Error reading data streams from \"%ls\"", path);
                win32_error(err);
                ret = WIMLIB_ERR_READ;
        }
out_find_close:
        FindClose(hFind);
        return ret;
unnamed_only:
        /* FindFirstStreamW() API is not available, or the volume does not
         * support named streams.  Only capture the unnamed data stream. */
        DEBUG("Only capturing unnamed data stream");
        if (inode->i_attributes &
             (FILE_ATTRIBUTE_REPARSE_POINT | FILE_ATTRIBUTE_DIRECTORY))
        {
                ret = 0;
        } else {
                /* Just create our own WIN32_FIND_STREAM_DATA for an unnamed
                 * stream to reduce the code to a call to the
                 * already-implemented win32_capture_stream() */
                wcscpy(dat.cStreamName, L"::$DATA");
                dat.StreamSize.QuadPart = file_size;
                ret = win32_capture_stream(path,
                                           path_num_chars,
                                           inode, lookup_table,
                                           &dat);
        }
        return ret;
}

static int
win32_build_dentry_tree_recursive(struct wim_dentry **root_ret,
                                  wchar_t *path,
                                  size_t path_num_chars,
                                  struct add_image_params *params,
                                  struct win32_capture_state *state,
                                  unsigned vol_flags)
{
        struct wim_dentry *root = NULL;
        struct wim_inode *inode;
        DWORD err;
        u64 file_size;
        int ret;
        u8 *rpbuf;
        u16 rpbuflen;
        u16 not_rpfixed;

        if (exclude_path(path, path_num_chars, params->config, true)) {
                if (params->add_image_flags & WIMLIB_ADD_IMAGE_FLAG_ROOT) {
                        ERROR("Cannot exclude the root directory from capture");
                        ret = WIMLIB_ERR_INVALID_CAPTURE_CONFIG;
                        goto out;
                }
                if ((params->add_image_flags & WIMLIB_ADD_IMAGE_FLAG_EXCLUDE_VERBOSE)
                    && params->progress_func)
                {
                        union wimlib_progress_info info;
                        info.scan.cur_path = path;
                        info.scan.excluded = true;
                        params->progress_func(WIMLIB_PROGRESS_MSG_SCAN_DENTRY, &info);
                }
                ret = 0;
                goto out;
        }

        if ((params->add_image_flags & WIMLIB_ADD_IMAGE_FLAG_VERBOSE)
            && params->progress_func)
        {
                union wimlib_progress_info info;
                info.scan.cur_path = path;
                info.scan.excluded = false;
                params->progress_func(WIMLIB_PROGRESS_MSG_SCAN_DENTRY, &info);
        }

        HANDLE hFile = win32_open_existing_file(path,
                                                FILE_READ_DATA | FILE_READ_ATTRIBUTES);
        if (hFile == INVALID_HANDLE_VALUE) {
                err = GetLastError();
                ERROR("Win32 API: Failed to open \"%ls\"", path);
                win32_error(err);
                ret = WIMLIB_ERR_OPEN;
                goto out;
        }

        BY_HANDLE_FILE_INFORMATION file_info;
        if (!GetFileInformationByHandle(hFile, &file_info)) {
                err = GetLastError();
                ERROR("Win32 API: Failed to get file information for \"%ls\"",
                      path);
                win32_error(err);
                ret = WIMLIB_ERR_STAT;
                goto out_close_handle;
        }

        if (file_info.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) {
                rpbuf = alloca(REPARSE_POINT_MAX_SIZE);
                ret = win32_get_reparse_data(hFile, path, params,
                                             rpbuf, &rpbuflen);
                if (ret < 0) {
                        /* WIMLIB_ERR_* (inverted) */
                        ret = -ret;
                        goto out_close_handle;
                } else if (ret & RP_FIXED) {
                        not_rpfixed = 0;
                } else if (ret == RP_EXCLUDED) {
                        ret = 0;
                        goto out_close_handle;
                } else {
                        not_rpfixed = 1;
                }
        }

        /* Create a WIM dentry with an associated inode, which may be shared.
         *
         * However, we need to explicitly check for directories and files with
         * only 1 link and refuse to hard link them.  This is because Windows
         * has a bug where it can return duplicate File IDs for files and
         * directories on the FAT filesystem. */
        ret = inode_table_new_dentry(params->inode_table,
                                     path_basename_with_len(path, path_num_chars),
                                     ((u64)file_info.nFileIndexHigh << 32) |
                                         (u64)file_info.nFileIndexLow,
                                     file_info.dwVolumeSerialNumber,
                                     (file_info.nNumberOfLinks <= 1 ||
                                        (file_info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)),
                                     &root);
        if (ret)
                goto out_close_handle;

        ret = win32_get_short_name(root, path);
        if (ret)
                goto out_close_handle;

        inode = root->d_inode;

        if (inode->i_nlink > 1) /* Shared inode; nothing more to do */
                goto out_close_handle;

        inode->i_attributes = file_info.dwFileAttributes;
        inode->i_creation_time = FILETIME_to_u64(&file_info.ftCreationTime);
        inode->i_last_write_time = FILETIME_to_u64(&file_info.ftLastWriteTime);
        inode->i_last_access_time = FILETIME_to_u64(&file_info.ftLastAccessTime);
        inode->i_resolved = 1;

        params->add_image_flags &= ~(WIMLIB_ADD_IMAGE_FLAG_ROOT | WIMLIB_ADD_IMAGE_FLAG_SOURCE);

        if (!(params->add_image_flags & WIMLIB_ADD_IMAGE_FLAG_NO_ACLS)
            && (vol_flags & FILE_PERSISTENT_ACLS))
        {
                ret = win32_get_security_descriptor(root, params->sd_set,
                                                    path, state,
                                                    params->add_image_flags);
                if (ret)
                        goto out_close_handle;
        }

        file_size = ((u64)file_info.nFileSizeHigh << 32) |
                     (u64)file_info.nFileSizeLow;

        CloseHandle(hFile);

        /* Capture the unnamed data stream (only should be present for regular
         * files) and any alternate data streams. */
        ret = win32_capture_streams(path,
                                    path_num_chars,
                                    inode,
                                    params->lookup_table,
                                    file_size,
                                    vol_flags);
        if (ret)
                goto out;

        if (inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
                /* Reparse point: set the reparse data (which we read already)
                 * */
                inode->i_not_rpfixed = not_rpfixed;
                inode->i_reparse_tag = le32_to_cpu(*(u32*)rpbuf);
                ret = inode_set_unnamed_stream(inode, rpbuf + 8, rpbuflen - 8,
                                               params->lookup_table);
        } else if (inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY) {
                /* Directory (not a reparse point) --- recurse to children */
                ret = win32_recurse_directory(root,
                                              path,
                                              path_num_chars,
                                              params,
                                              state,
                                              vol_flags);
        }
        goto out;
out_close_handle:
        CloseHandle(hFile);
out:
        if (ret == 0)
                *root_ret = root;
        else
                free_dentry_tree(root, params->lookup_table);
        return ret;
}

static void
win32_do_capture_warnings(const struct win32_capture_state *state,
                          int add_image_flags)
{
        if (state->num_get_sacl_priv_notheld == 0 &&
            state->num_get_sd_access_denied == 0)
                return;

        WARNING("");
        WARNING("Built dentry tree successfully, but with the following problem(s):");
        if (state->num_get_sacl_priv_notheld != 0) {
                WARNING("Could not capture SACL (System Access Control List)\n"
                        "          on %lu files or directories.",
                        state->num_get_sacl_priv_notheld);
        }
        if (state->num_get_sd_access_denied != 0) {
                WARNING("Could not capture security descriptor at all\n"
                        "          on %lu files or directories.",
                        state->num_get_sd_access_denied);
        }
        WARNING(
          "Try running the program as the Administrator to make sure all the\n"
"          desired metadata has been captured exactly.  However, if you\n"
"          do not care about capturing security descriptors correctly, then\n"
"          nothing more needs to be done%ls\n",
        (add_image_flags & WIMLIB_ADD_IMAGE_FLAG_NO_ACLS) ? L"." :
         L", although you might consider\n"
"          passing the --no-acls flag to `wimlib-imagex capture' or\n"
"          `wimlib-imagex append' to explicitly capture no security\n"
"          descriptors.\n");
}

/* Win32 version of capturing a directory tree */
int
win32_build_dentry_tree(struct wim_dentry **root_ret,
                        const wchar_t *root_disk_path,
                        struct add_image_params *params)
{
        size_t path_nchars;
        wchar_t *path;
        int ret;
        struct win32_capture_state state;
        unsigned vol_flags;


        path_nchars = wcslen(root_disk_path);
        if (path_nchars > 32767)
                return WIMLIB_ERR_INVALID_PARAM;

        if (GetFileAttributesW(root_disk_path) == INVALID_FILE_ATTRIBUTES &&
            GetLastError() == ERROR_FILE_NOT_FOUND)
        {
                ERROR("Capture directory \"%ls\" does not exist!",
                      root_disk_path);
                return WIMLIB_ERR_OPENDIR;
        }

        ret = win32_get_file_and_vol_ids(root_disk_path,
                                         &params->capture_root_ino,
                                         &params->capture_root_dev);
        if (ret)
                return ret;

        win32_get_vol_flags(root_disk_path, &vol_flags);

        /* There is no check for overflow later when this buffer is being used!
         * But the max path length on NTFS is 32767 characters, and paths need
         * to be written specially to even go past 260 characters, so we should
         * be okay with 32770 characters. */
        path = MALLOC(32770 * sizeof(wchar_t));
        if (!path)
                return WIMLIB_ERR_NOMEM;

        wmemcpy(path, root_disk_path, path_nchars + 1);

        memset(&state, 0, sizeof(state));
        ret = win32_build_dentry_tree_recursive(root_ret, path,
                                                path_nchars, params,
                                                &state, vol_flags);
        FREE(path);
        if (ret == 0)
                win32_do_capture_warnings(&state, params->add_image_flags);
        return ret;
}

static int
win32_extract_try_rpfix(u8 *rpbuf,
                        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, 8 + le16_to_cpu(*(u16*)(rpbuf + 4)),
                                 &rpdata);
        if (ret)
                return ret;

        if (extract_root_realpath[0] == L'\0' ||
            extract_root_realpath[1] != L':' ||
            extract_root_realpath[2] != L'\\')
        {
                ERROR("Can't understand full path format \"%ls\".  "
                      "Try turning reparse point fixups off...",
                      extract_root_realpath);
                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 + 6;
        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 */
                wmemcpy(p, L"\\??\\", 4);
                p += 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 */
        wmemcpy(p, extract_root_realpath + 2, extract_root_realpath_nchars - 2);
        p += extract_root_realpath_nchars - 2;

        /* Append the stripped target */
        wmemcpy(p, stripped_target, stripped_target_nchars);
        p += 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)
        {
                ERROR("Path names too long to do reparse point fixup!");
                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);
}

/* Wrapper around the FSCTL_SET_REPARSE_POINT ioctl to set the reparse data on
 * an extracted reparse point. */
static int
win32_set_reparse_data(HANDLE h,
                       const struct wim_inode *inode,
                       const struct wim_lookup_table_entry *lte,
                       const wchar_t *path,
                       const struct apply_args *args)
{
        int ret;
        u8 rpbuf[REPARSE_POINT_MAX_SIZE];
        DWORD bytesReturned;

        DEBUG("Setting reparse data on \"%ls\"", path);

        ret = wim_inode_get_reparse_data(inode, rpbuf);
        if (ret)
                return ret;

        if (args->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 = win32_extract_try_rpfix(rpbuf,
                                              args->target_realpath,
                                              args->target_realpath_len);
                if (ret)
                        return WIMLIB_ERR_REPARSE_POINT_FIXUP_FAILED;
        }

        /* Set the reparse data on the open file using the
         * FSCTL_SET_REPARSE_POINT ioctl.
         *
         * There are contradictions in Microsoft's documentation for this:
         *
         * "If hDevice was opened without specifying FILE_FLAG_OVERLAPPED,
         * lpOverlapped is ignored."
         *
         * --- So setting lpOverlapped to NULL is okay since it's ignored.
         *
         * "If lpOverlapped is NULL, lpBytesReturned cannot be NULL. Even when an
         * operation returns no output data and lpOutBuffer is NULL,
         * DeviceIoControl makes use of lpBytesReturned. After such an
         * operation, the value of lpBytesReturned is meaningless."
         *
         * --- So lpOverlapped not really ignored, as it affects another
         *  parameter.  This is the actual behavior: lpBytesReturned must be
         *  specified, even though lpBytesReturned is documented as:
         *
         *  "Not used with this operation; set to NULL."
         */
        if (!DeviceIoControl(h, FSCTL_SET_REPARSE_POINT, rpbuf,
                             8 + le16_to_cpu(*(u16*)(rpbuf + 4)),
                             NULL, 0,
                             &bytesReturned /* lpBytesReturned */,
                             NULL /* lpOverlapped */))
        {
                DWORD err = GetLastError();
                ERROR("Failed to set reparse data on \"%ls\"", path);
                win32_error(err);
                if (err == ERROR_ACCESS_DENIED || err == ERROR_PRIVILEGE_NOT_HELD)
                        return WIMLIB_ERR_INSUFFICIENT_PRIVILEGES_TO_EXTRACT;
                else if (inode->i_reparse_tag == WIM_IO_REPARSE_TAG_SYMLINK ||
                         inode->i_reparse_tag == WIM_IO_REPARSE_TAG_MOUNT_POINT)
                        return WIMLIB_ERR_LINK;
                else
                        return WIMLIB_ERR_WRITE;
        }
        return 0;
}

/* Wrapper around the FSCTL_SET_COMPRESSION ioctl to change the
 * FILE_ATTRIBUTE_COMPRESSED flag of a file or directory. */
static int
win32_set_compression_state(HANDLE hFile, USHORT format, const wchar_t *path)
{
        DWORD bytesReturned;
        if (!DeviceIoControl(hFile, FSCTL_SET_COMPRESSION,
                             &format, sizeof(USHORT),
                             NULL, 0,
                             &bytesReturned, NULL))
        {
                /* Could be a warning only, but we only call this if the volume
                 * supports compression.  So I'm calling this an error. */
                DWORD err = GetLastError();
                ERROR("Failed to set compression flag on \"%ls\"", path);
                win32_error(err);
                if (err == ERROR_ACCESS_DENIED || err == ERROR_PRIVILEGE_NOT_HELD)
                        return WIMLIB_ERR_INSUFFICIENT_PRIVILEGES_TO_EXTRACT;
                else
                        return WIMLIB_ERR_WRITE;
        }
        return 0;
}

/* Wrapper around FSCTL_SET_SPARSE ioctl to set a file as sparse. */
static int
win32_set_sparse(HANDLE hFile, const wchar_t *path)
{
        DWORD bytesReturned;
        if (!DeviceIoControl(hFile, FSCTL_SET_SPARSE,
                             NULL, 0,
                             NULL, 0,
                             &bytesReturned, NULL))
        {
                /* Could be a warning only, but we only call this if the volume
                 * supports sparse files.  So I'm calling this an error. */
                DWORD err = GetLastError();
                WARNING("Failed to set sparse flag on \"%ls\"", path);
                win32_error(err);
                if (err == ERROR_ACCESS_DENIED || err == ERROR_PRIVILEGE_NOT_HELD)
                        return WIMLIB_ERR_INSUFFICIENT_PRIVILEGES_TO_EXTRACT;
                else
                        return WIMLIB_ERR_WRITE;
        }
        return 0;
}

/*
 * Sets the security descriptor on an extracted file.
 */
static int
win32_set_security_data(const struct wim_inode *inode,
                        HANDLE hFile,
                        const wchar_t *path,
                        struct apply_args *args)
{
        PSECURITY_DESCRIPTOR descriptor;
        unsigned long n;
        DWORD err;
        const struct wim_security_data *sd;

        SECURITY_INFORMATION securityInformation = 0;

        void *owner = NULL;
        void *group = NULL;
        ACL *dacl = NULL;
        ACL *sacl = NULL;

        BOOL owner_defaulted;
        BOOL group_defaulted;
        BOOL dacl_present;
        BOOL dacl_defaulted;
        BOOL sacl_present;
        BOOL sacl_defaulted;

        sd = wim_const_security_data(args->w);
        descriptor = sd->descriptors[inode->i_security_id];

        GetSecurityDescriptorOwner(descriptor, &owner, &owner_defaulted);
        if (owner)
                securityInformation |= OWNER_SECURITY_INFORMATION;

        GetSecurityDescriptorGroup(descriptor, &group, &group_defaulted);
        if (group)
                securityInformation |= GROUP_SECURITY_INFORMATION;

        GetSecurityDescriptorDacl(descriptor, &dacl_present,
                                  &dacl, &dacl_defaulted);
        if (dacl)
                securityInformation |= DACL_SECURITY_INFORMATION;

        GetSecurityDescriptorSacl(descriptor, &sacl_present,
                                  &sacl, &sacl_defaulted);
        if (sacl)
                securityInformation |= SACL_SECURITY_INFORMATION;

again:
        if (securityInformation == 0)
                return 0;
        if (SetSecurityInfo(hFile, SE_FILE_OBJECT,
                            securityInformation, owner, group, dacl, sacl))
                return 0;
        err = GetLastError();
        if (args->extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_ACLS)
                goto fail;
        switch (err) {
        case ERROR_PRIVILEGE_NOT_HELD:
                if (securityInformation & SACL_SECURITY_INFORMATION) {
                        n = args->num_set_sacl_priv_notheld++;
                        securityInformation &= ~SACL_SECURITY_INFORMATION;
                        sacl = NULL;
                        if (n < MAX_SET_SACL_PRIV_NOTHELD_WARNINGS) {
                                WARNING(
"We don't have enough privileges to set the full security\n"
"          descriptor on \"%ls\"!\n", path);
                                if (args->num_set_sd_access_denied +
                                    args->num_set_sacl_priv_notheld == 1)
                                {
                                        WARNING("%ls", apply_access_denied_msg);
                                }
                                WARNING("Re-trying with SACL omitted.\n", path);
                        } else if (n == MAX_GET_SACL_PRIV_NOTHELD_WARNINGS) {
                                WARNING(
"Suppressing further 'privileges not held' error messages when setting\n"
"          security descriptors.");
                        }
                        goto again;
                }
                /* Fall through */
        case ERROR_INVALID_OWNER:
        case ERROR_ACCESS_DENIED:
                n = args->num_set_sd_access_denied++;
                if (n < MAX_SET_SD_ACCESS_DENIED_WARNINGS) {
                        WARNING("Failed to set security descriptor on \"%ls\": "
                                "Access denied!\n", path);
                        if (args->num_set_sd_access_denied +
                            args->num_set_sacl_priv_notheld == 1)
                        {
                                WARNING("%ls", apply_access_denied_msg);
                        }
                } else if (n == MAX_SET_SD_ACCESS_DENIED_WARNINGS) {
                        WARNING(
"Suppressing further access denied error messages when setting\n"
"          security descriptors");
                }
                return 0;
        default:
fail:
                ERROR("Failed to set security descriptor on \"%ls\"", path);
                win32_error(err);
                if (err == ERROR_ACCESS_DENIED || err == ERROR_PRIVILEGE_NOT_HELD)
                        return WIMLIB_ERR_INSUFFICIENT_PRIVILEGES_TO_EXTRACT;
                else
                        return WIMLIB_ERR_WRITE;
        }
}


static int
win32_extract_chunk(const void *buf, size_t len, void *arg)
{
        HANDLE hStream = arg;

        DWORD nbytes_written;
        wimlib_assert(len <= 0xffffffff);

        if (!WriteFile(hStream, buf, len, &nbytes_written, NULL) ||
            nbytes_written != len)
        {
                DWORD err = GetLastError();
                ERROR("WriteFile(): write error");
                win32_error(err);
                return WIMLIB_ERR_WRITE;
        }
        return 0;
}

static int
do_win32_extract_stream(HANDLE hStream, const struct wim_lookup_table_entry *lte)
{
        return extract_wim_resource(lte, wim_resource_size(lte),
                                    win32_extract_chunk, hStream);
}

struct win32_encrypted_extract_ctx {
        const struct wim_lookup_table_entry *lte;
        u64 offset;
};

static DWORD WINAPI
win32_encrypted_import_cb(unsigned char *data, void *_ctx,
                          unsigned long *len_p)
{
        struct win32_encrypted_extract_ctx *ctx = _ctx;
        unsigned long len = *len_p;
        const struct wim_lookup_table_entry *lte = ctx->lte;

        len = min(len, wim_resource_size(lte) - ctx->offset);

        if (read_partial_wim_resource_into_buf(lte, len, ctx->offset, data, false))
                return ERROR_READ_FAULT;

        ctx->offset += len;
        *len_p = len;
        return ERROR_SUCCESS;
}

/* Create an encrypted file and extract the raw encrypted data to it.
 *
 * @path:  Path to encrypted file to create.
 * @lte:   WIM lookup_table entry for the raw encrypted data.
 *
 * This is separate from do_win32_extract_stream() because the WIM is supposed
 * to contain the *raw* encrypted data, which needs to be extracted ("imported")
 * using the special APIs OpenEncryptedFileRawW(), WriteEncryptedFileRaw(), and
 * CloseEncryptedFileRaw().
 *
 * Returns 0 on success; nonzero on failure.
 */
static int
do_win32_extract_encrypted_stream(const wchar_t *path,
                                  const struct wim_lookup_table_entry *lte)
{
        void *file_ctx;
        int ret;

        DEBUG("Opening file \"%ls\" to extract raw encrypted data", path);

        ret = OpenEncryptedFileRawW(path, CREATE_FOR_IMPORT, &file_ctx);
        if (ret) {
                ERROR("Failed to open \"%ls\" to write raw encrypted data", path);
                win32_error(ret);
                return WIMLIB_ERR_OPEN;
        }

        if (lte) {
                struct win32_encrypted_extract_ctx ctx;

                ctx.lte = lte;
                ctx.offset = 0;
                ret = WriteEncryptedFileRaw(win32_encrypted_import_cb, &ctx, file_ctx);
                if (ret == ERROR_SUCCESS) {
                        ret = 0;
                } else {
                        ret = WIMLIB_ERR_WRITE;
                        ERROR("Failed to extract encrypted file \"%ls\"", path);
                }
        }
        CloseEncryptedFileRaw(file_ctx);
        return ret;
}

static bool
path_is_root_of_drive(const wchar_t *path)
{
        if (!*path)
                return false;

        if (*path != L'/' && *path != L'\\') {
                if (*(path + 1) == L':')
                        path += 2;
                else
                        return false;
        }
        while (*path == L'/' || *path == L'\\')
                path++;
        return (*path == L'\0');
}

static inline DWORD
win32_mask_attributes(DWORD i_attributes)
{
        return i_attributes & ~(FILE_ATTRIBUTE_SPARSE_FILE |
                                FILE_ATTRIBUTE_COMPRESSED |
                                FILE_ATTRIBUTE_REPARSE_POINT |
                                FILE_ATTRIBUTE_DIRECTORY |
                                FILE_ATTRIBUTE_ENCRYPTED |
                                FILE_FLAG_DELETE_ON_CLOSE |
                                FILE_FLAG_NO_BUFFERING |
                                FILE_FLAG_OPEN_NO_RECALL |
                                FILE_FLAG_OVERLAPPED |
                                FILE_FLAG_RANDOM_ACCESS |
                                /*FILE_FLAG_SESSION_AWARE |*/
                                FILE_FLAG_SEQUENTIAL_SCAN |
                                FILE_FLAG_WRITE_THROUGH);
}

static inline DWORD
win32_get_create_flags_and_attributes(DWORD i_attributes)
{
        /*
         * Some attributes cannot be set by passing them to CreateFile().  In
         * particular:
         *
         * FILE_ATTRIBUTE_DIRECTORY:
         *   CreateDirectory() must be called instead of CreateFile().
         *
         * FILE_ATTRIBUTE_SPARSE_FILE:
         *   Needs an ioctl.
         *   See: win32_set_sparse().
         *
         * FILE_ATTRIBUTE_COMPRESSED:
         *   Not clear from the documentation, but apparently this needs an
         *   ioctl as well.
         *   See: win32_set_compressed().
         *
         * FILE_ATTRIBUTE_REPARSE_POINT:
         *   Needs an ioctl, with the reparse data specified.
         *   See: win32_set_reparse_data().
         *
         * In addition, clear any file flags in the attributes that we don't
         * want, but also specify FILE_FLAG_OPEN_REPARSE_POINT and
         * FILE_FLAG_BACKUP_SEMANTICS as we are a backup application.
         */
        return win32_mask_attributes(i_attributes) |
                FILE_FLAG_OPEN_REPARSE_POINT |
                FILE_FLAG_BACKUP_SEMANTICS;
}

/* Set compression and/or sparse attributes on a stream, if supported by the
 * volume. */
static int
win32_set_special_stream_attributes(HANDLE hFile, const struct wim_inode *inode,
                                    struct wim_lookup_table_entry *unnamed_stream_lte,
                                    const wchar_t *path, unsigned vol_flags)
{
        int ret;

        if (inode->i_attributes & FILE_ATTRIBUTE_COMPRESSED) {
                if (vol_flags & FILE_FILE_COMPRESSION) {
                        ret = win32_set_compression_state(hFile,
                                                          COMPRESSION_FORMAT_DEFAULT,
                                                          path);
                        if (ret)
                                return ret;
                } else {
                        DEBUG("Cannot set compression attribute on \"%ls\": "
                              "volume does not support transparent compression",
                              path);
                }
        }

        if (inode->i_attributes & FILE_ATTRIBUTE_SPARSE_FILE) {
                if (vol_flags & FILE_SUPPORTS_SPARSE_FILES) {
                        DEBUG("Setting sparse flag on \"%ls\"", path);
                        ret = win32_set_sparse(hFile, path);
                        if (ret)
                                return ret;
                } else {
                        DEBUG("Cannot set sparse attribute on \"%ls\": "
                              "volume does not support sparse files",
                              path);
                }
        }
        return 0;
}

/* Pre-create directories; extract encrypted streams */
static int
win32_begin_extract_unnamed_stream(const struct wim_inode *inode,
                                   const struct wim_lookup_table_entry *lte,
                                   const wchar_t *path,
                                   DWORD *creationDisposition_ret,
                                   unsigned int vol_flags)
{
        DWORD err;
        int ret;

        /* Directories must be created with CreateDirectoryW().  Then the call
         * to CreateFileW() will merely open the directory that was already
         * created rather than creating a new file. */
        if (inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY &&
            !path_is_root_of_drive(path)) {
                if (!CreateDirectoryW(path, NULL)) {
                        err = GetLastError();
                        if (err != ERROR_ALREADY_EXISTS) {
                                ERROR("Failed to create directory \"%ls\"",
                                      path);
                                win32_error(err);
                                return WIMLIB_ERR_MKDIR;
                        }
                }
                DEBUG("Created directory \"%ls\"", path);
                *creationDisposition_ret = OPEN_EXISTING;
        }
        if (inode->i_attributes & FILE_ATTRIBUTE_ENCRYPTED &&
            vol_flags & FILE_SUPPORTS_ENCRYPTION)
        {
                if (inode->i_attributes & FILE_ATTRIBUTE_DIRECTORY) {
                        unsigned remaining_sharing_violations = 100;
                        while (!EncryptFile(path)) {
                                if (remaining_sharing_violations &&
                                    err == ERROR_SHARING_VIOLATION)
                                {
                                        WARNING("Couldn't encrypt directory \"%ls\" "
                                                "due to sharing violation; re-trying "
                                                "after 100 ms", path);
                                        Sleep(100);
                                        remaining_sharing_violations--;
                                } else {
                                        err = GetLastError();
                                        ERROR("Failed to encrypt directory \"%ls\"",
                                              path);
                                        win32_error(err);
                                        return WIMLIB_ERR_WRITE;
                                }
                        }
                } else {
                        ret = do_win32_extract_encrypted_stream(path, lte);
                        if (ret)
                                return ret;
                        DEBUG("Extracted encrypted file \"%ls\"", path);
                }
                *creationDisposition_ret = OPEN_EXISTING;
        }

        /* Set file attributes if we created the file.  Otherwise, we haven't
         * created the file set and we will set the attributes in the call to
         * CreateFileW().
         *
         * The FAT filesystem does not let you change the attributes of the root
         * directory, so treat that as a special case and do not set attributes.
         * */
        if (*creationDisposition_ret == OPEN_EXISTING &&
            !path_is_root_of_drive(path))
        {
                if (!SetFileAttributesW(path,
                                        win32_mask_attributes(inode->i_attributes)))
                {
                        err = GetLastError();
                        ERROR("Failed to set attributes on \"%ls\"", path);
                        win32_error(err);
                        return WIMLIB_ERR_WRITE;
                }
        }
        return 0;
}

/* Set security descriptor and extract stream data or reparse data (skip the
 * unnamed data stream of encrypted files, which was already extracted). */
static int
win32_finish_extract_stream(HANDLE h, const struct wim_dentry *dentry,
                            const struct wim_lookup_table_entry *lte,
                            const wchar_t *stream_path,
                            const wchar_t *stream_name_utf16,
                            struct apply_args *args)
{
        int ret = 0;
        const struct wim_inode *inode = dentry->d_inode;
        const wchar_t *short_name;
        if (stream_name_utf16 == NULL) {
                /* Unnamed stream. */

                /* Set security descriptor, unless the extract_flags indicate
                 * not to or the volume does not supported it.  Note that this
                 * is only done when the unnamed stream is being extracted, as
                 * security descriptors are per-file and not per-stream. */
                if (inode->i_security_id >= 0 &&
                    !(args->extract_flags & WIMLIB_EXTRACT_FLAG_NO_ACLS)
                    && (args->vol_flags & FILE_PERSISTENT_ACLS))
                {
                        ret = win32_set_security_data(inode, h, stream_path, args);
                        if (ret)
                                return ret;
                }

                /* Handle reparse points.  The data for them needs to be set
                 * using a special ioctl.  Note that the reparse point may have
                 * been created using CreateFileW() in the case of
                 * non-directories or CreateDirectoryW() in the case of
                 * directories; but the ioctl works either way.  Also, it is
                 * only this step that actually sets the
                 * FILE_ATTRIBUTE_REPARSE_POINT, as it is not valid to set it
                 * using SetFileAttributesW() or CreateFileW().
                 *
                 * If the volume does not support reparse points we simply
                 * ignore the reparse data.  (N.B. the code currently doesn't
                 * actually reach this case because reparse points are skipped
                 * entirely on such volumes.) */
                if (inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT) {
                        if (args->vol_flags & FILE_SUPPORTS_REPARSE_POINTS) {
                                ret = win32_set_reparse_data(h, inode,
                                                             lte, stream_path,
                                                             args);
                                if (ret)
                                        return ret;
                        } else {
                                DEBUG("Cannot set reparse data on \"%ls\": volume "
                                      "does not support reparse points", stream_path);
                        }
                } else if (lte != NULL &&
                           !(args->vol_flags & FILE_SUPPORTS_ENCRYPTION &&
                             inode->i_attributes & FILE_ATTRIBUTE_ENCRYPTED))
                {
                        /* Extract the data of the unnamed stream, unless the
                         * lookup table entry is NULL (indicating an empty
                         * stream for which no data needs to be extracted), or
                         * the stream is encrypted and therefore was already
                         * extracted as a special case. */
                        ret = do_win32_extract_stream(h, lte);
                        if (ret)
                                return ret;
                }

                if (dentry_has_short_name(dentry))
                        short_name = dentry->short_name;
                else
                        short_name = L"";
                /* Set short name */
                if (!SetFileShortNameW(h, short_name)) {
                #if 0
                        DWORD err = GetLastError();
                        ERROR("Could not set short name on \"%ls\"", stream_path);
                        win32_error(err);
                #endif
                }
        } else {
                /* Extract the data for a named data stream. */
                if (lte != NULL) {
                        DEBUG("Extracting named data stream \"%ls\" (len = %"PRIu64")",
                              stream_path, wim_resource_size(lte));
                        ret = do_win32_extract_stream(h, lte);
                }
        }
        return ret;
}

static int
win32_decrypt_file(HANDLE open_handle, const wchar_t *path)
{
        DWORD err;
        /* We cannot call DecryptFileW() while there is an open handle to the
         * file.  So close it first. */
        if (!CloseHandle(open_handle)) {
                err = GetLastError();
                ERROR("Failed to close handle for \"%ls\"", path);
                win32_error(err);
                return WIMLIB_ERR_WRITE;
        }
        if (!DecryptFileW(path, 0 /* reserved parameter; set to 0 */)) {
                err = GetLastError();
                ERROR("Failed to decrypt file \"%ls\"", path);
                win32_error(err);
                return WIMLIB_ERR_WRITE;
        }
        return 0;
}

/*
 * Create and extract a stream to a file, or create a directory, using the
 * Windows API.
 *
 * This handles reparse points, directories, alternate data streams, encrypted
 * files, compressed files, etc.
 *
 * @dentry: WIM dentry for the file or directory being extracted.
 *
 * @path:  Path to extract the file to.
 *
 * @stream_name_utf16:
 *         Name of the stream, or NULL if the stream is unnamed.  This will
 *         be called with a NULL stream_name_utf16 before any non-NULL
 *         stream_name_utf16's.
 *
 * @lte:   WIM lookup table entry for the stream.  May be NULL to indicate
 *         a stream of length 0.
 *
 * @args:  Additional apply context, including flags indicating supported
 *         volume features.
 *
 * Returns 0 on success; nonzero on failure.
 */
static int
win32_extract_stream(const struct wim_dentry *dentry,
                     const wchar_t *path,
                     const wchar_t *stream_name_utf16,
                     struct wim_lookup_table_entry *lte,
                     struct apply_args *args)
{
        wchar_t *stream_path;
        HANDLE h;
        int ret;
        DWORD err;
        DWORD creationDisposition = CREATE_ALWAYS;
        DWORD requestedAccess;
        BY_HANDLE_FILE_INFORMATION file_info;
        unsigned remaining_sharing_violations = 1000;
        const struct wim_inode *inode = dentry->d_inode;

        if (stream_name_utf16) {
                /* Named stream.  Create a buffer that contains the UTF-16LE
                 * string [./]path:stream_name_utf16.  This is needed to
                 * create and open the stream using CreateFileW().  I'm not
                 * aware of any other APIs to do this.  Note: the '$DATA' suffix
                 * seems to be unneeded.  Additional note: a "./" prefix needs
                 * to be added when the path is not absolute to avoid ambiguity
                 * with drive letters. */
                size_t stream_path_nchars;
                size_t path_nchars;
                size_t stream_name_nchars;
                const wchar_t *prefix;

                path_nchars = wcslen(path);
                stream_name_nchars = wcslen(stream_name_utf16);
                stream_path_nchars = path_nchars + 1 + stream_name_nchars;
                if (path[0] != cpu_to_le16(L'\0') &&
                    path[0] != cpu_to_le16(L'/') &&
                    path[0] != cpu_to_le16(L'\\') &&
                    path[1] != cpu_to_le16(L':'))
                {
                        prefix = L"./";
                        stream_path_nchars += 2;
                } else {
                        prefix = L"";
                }
                stream_path = alloca((stream_path_nchars + 1) * sizeof(wchar_t));
                swprintf(stream_path, L"%ls%ls:%ls",
                         prefix, path, stream_name_utf16);
        } else {
                /* Unnamed stream; its path is just the path to the file itself.
                 * */
                stream_path = (wchar_t*)path;

                ret = win32_begin_extract_unnamed_stream(inode, lte, path,
                                                         &creationDisposition,
                                                         args->vol_flags);
                if (ret)
                        goto fail;
        }

        DEBUG("Opening \"%ls\"", stream_path);
        /* DELETE access is needed for SetFileShortNameW(), for some reason. */
        requestedAccess = GENERIC_READ | GENERIC_WRITE | DELETE |
                          ACCESS_SYSTEM_SECURITY;
try_open_again:
        /* Open the stream to be extracted.  Depending on what we have set
         * creationDisposition to, we may be creating this for the first time,
         * or we may be opening on existing stream we already created using
         * CreateDirectoryW() or OpenEncryptedFileRawW(). */
        h = CreateFileW(stream_path,
                        requestedAccess,
                        FILE_SHARE_READ,
                        NULL,
                        creationDisposition,
                        win32_get_create_flags_and_attributes(inode->i_attributes),
                        NULL);
        if (h == INVALID_HANDLE_VALUE) {
                err = GetLastError();
                if (err == ERROR_ACCESS_DENIED &&
                    path_is_root_of_drive(stream_path))
                {
                        ret = 0;
                        goto out;
                }
                if ((err == ERROR_PRIVILEGE_NOT_HELD ||
                     err == ERROR_ACCESS_DENIED) &&
                    (requestedAccess & ACCESS_SYSTEM_SECURITY))
                {
                        /* Try opening the file again without privilege to
                         * modify SACL. */
                        requestedAccess &= ~ACCESS_SYSTEM_SECURITY;
                        goto try_open_again;
                }
                if (err == ERROR_SHARING_VIOLATION) {
                        if (remaining_sharing_violations) {
                                --remaining_sharing_violations;
                                /* This can happen when restoring encrypted directories
                                 * for some reason.  Probably a bug in EncryptFile(). */
                                WARNING("Couldn't open \"%ls\" due to sharing violation; "
                                        "re-trying after 100ms", stream_path);
                                Sleep(100);
                                goto try_open_again;
                        } else {
                                ERROR("Too many sharing violations; giving up...");
                        }
                } else {
                        if (creationDisposition == OPEN_EXISTING)
                                ERROR("Failed to open \"%ls\"", stream_path);
                        else
                                ERROR("Failed to create \"%ls\"", stream_path);
                        win32_error(err);
                }
                ret = WIMLIB_ERR_OPEN;
                goto fail;
        }

        /* Check the attributes of the file we just opened, and remove
         * encryption or compression if either was set by default but is not
         * supposed to be set based on the WIM inode attributes. */
        if (!GetFileInformationByHandle(h, &file_info)) {
                err = GetLastError();
                ERROR("Failed to get attributes of \"%ls\"", stream_path);
                win32_error(err);
                ret = WIMLIB_ERR_STAT;
                goto fail_close_handle;
        }

        /* Remove encryption? */
        if (file_info.dwFileAttributes & FILE_ATTRIBUTE_ENCRYPTED &&
            !(inode->i_attributes & FILE_ATTRIBUTE_ENCRYPTED))
        {
                /* File defaulted to encrypted due to being in an encrypted
                 * directory, but is not actually supposed to be encrypted.
                 *
                 * This is a workaround, because I'm not aware of any way to
                 * directly (e.g. with CreateFileW()) create an unencrypted file
                 * in a directory with FILE_ATTRIBUTE_ENCRYPTED set. */
                ret = win32_decrypt_file(h, stream_path);
                if (ret)
                        goto fail; /* win32_decrypt_file() closed the handle. */
                creationDisposition = OPEN_EXISTING;
                goto try_open_again;
        }

        /* Remove compression? */
        if (file_info.dwFileAttributes & FILE_ATTRIBUTE_COMPRESSED &&
            !(inode->i_attributes & FILE_ATTRIBUTE_COMPRESSED))
        {
                /* Similar to the encrypted case, above, if the file defaulted
                 * to compressed due to being in an compressed directory, but is
                 * not actually supposed to be compressed, explicitly set the
                 * compression format to COMPRESSION_FORMAT_NONE. */
                ret = win32_set_compression_state(h, COMPRESSION_FORMAT_NONE,
                                                  stream_path);
                if (ret)
                        goto fail_close_handle;
        }

        /* Set compression and/or sparse attributes if needed */
        ret = win32_set_special_stream_attributes(h, inode, lte, path,
                                                  args->vol_flags);

        if (ret)
                goto fail_close_handle;

        /* At this point we have at least created the needed stream with the
         * appropriate attributes.  We have yet to set the appropriate security
         * descriptor and actually extract the stream data (other than for
         * extracted files, which were already extracted).
         * win32_finish_extract_stream() handles these additional steps. */
        ret = win32_finish_extract_stream(h, dentry, lte, stream_path,
                                          stream_name_utf16, args);
        if (ret)
                goto fail_close_handle;

        /* Done extracting the stream.  Close the handle and return. */
        DEBUG("Closing \"%ls\"", stream_path);
        if (!CloseHandle(h)) {
                err = GetLastError();
                ERROR("Failed to close \"%ls\"", stream_path);
                win32_error(err);
                ret = WIMLIB_ERR_WRITE;
                goto fail;
        }
        ret = 0;
        goto out;
fail_close_handle:
        CloseHandle(h);
fail:
        ERROR("Error extracting \"%ls\"", stream_path);
out:
        return ret;
}

/*
 * Creates a file, directory, or reparse point and extracts all streams to it
 * (unnamed data stream and/or reparse point stream, plus any alternate data
 * streams).  Handles sparse, compressed, and/or encrypted files.
 *
 * @dentry:     WIM dentry for this file or directory.
 * @path:       UTF-16LE external path to extract the inode to.
 * @args:       Additional extraction context.
 *
 * Returns 0 on success; nonzero on failure.
 */
static int
win32_extract_streams(const struct wim_dentry *dentry,
                      const wchar_t *path, struct apply_args *args)
{
        struct wim_lookup_table_entry *unnamed_lte;
        int ret;
        const struct wim_inode *inode = dentry->d_inode;

        /* First extract the unnamed stream. */

        unnamed_lte = inode_unnamed_lte_resolved(inode);
        ret = win32_extract_stream(dentry, path, NULL, unnamed_lte, args);
        if (ret)
                goto out;

        /* Extract any named streams, if supported by the volume. */

        if (!(args->vol_flags & FILE_NAMED_STREAMS))
                goto out;
        for (u16 i = 0; i < inode->i_num_ads; i++) {
                const struct wim_ads_entry *ads_entry = &inode->i_ads_entries[i];

                /* Skip the unnamed stream if it's in the ADS entries (we
                 * already extracted it...) */
                if (ads_entry->stream_name_nbytes == 0)
                        continue;

                /* Skip special UNIX data entries (see documentation for
                 * WIMLIB_ADD_IMAGE_FLAG_UNIX_DATA) */
                if (ads_entry->stream_name_nbytes == WIMLIB_UNIX_DATA_TAG_UTF16LE_NBYTES
                    && !memcmp(ads_entry->stream_name,
                               WIMLIB_UNIX_DATA_TAG_UTF16LE,
                               WIMLIB_UNIX_DATA_TAG_UTF16LE_NBYTES))
                        continue;

                /* Extract the named stream */
                ret = win32_extract_stream(dentry,
                                           path,
                                           ads_entry->stream_name,
                                           ads_entry->lte,
                                           args);
                if (ret)
                        break;
        }
out:
        return ret;
}

/* If not done already, load the supported feature flags for the volume onto
 * which the image is being extracted, and warn the user about any missing
 * features that could be important. */
static int
win32_check_vol_flags(const wchar_t *output_path, struct apply_args *args)
{
        if (args->have_vol_flags)
                return 0;

        win32_get_vol_flags(output_path, &args->vol_flags);
        args->have_vol_flags = true;
        /* Warn the user about data that may not be extracted. */
        if (!(args->vol_flags & FILE_SUPPORTS_SPARSE_FILES))
                WARNING("Volume does not support sparse files!\n"
                        "          Sparse files will be extracted as non-sparse.");
        if (!(args->vol_flags & FILE_SUPPORTS_REPARSE_POINTS))
                WARNING("Volume does not support reparse points!\n"
                        "          Reparse point data will not be extracted.");
        if (!(args->vol_flags & FILE_NAMED_STREAMS)) {
                WARNING("Volume does not support named data streams!\n"
                        "          Named data streams will not be extracted.");
        }
        if (!(args->vol_flags & FILE_SUPPORTS_ENCRYPTION)) {
                WARNING("Volume does not support encryption!\n"
                        "          Encrypted files will be extracted as raw data.");
        }
        if (!(args->vol_flags & FILE_FILE_COMPRESSION)) {
                WARNING("Volume does not support transparent compression!\n"
                        "          Compressed files will be extracted as non-compressed.");
        }
        if (!(args->vol_flags & FILE_PERSISTENT_ACLS)) {
                if (args->extract_flags & WIMLIB_EXTRACT_FLAG_STRICT_ACLS) {
                        ERROR("Strict ACLs requested, but the volume does not "
                              "support ACLs!");
                        return WIMLIB_ERR_VOLUME_LACKS_FEATURES;
                } else {
                        WARNING("Volume does not support persistent ACLS!\n"
                                "          File permissions will not be extracted.");
                }
        }
        return 0;
}

/*
 * Try extracting a hard link.
 *
 * @output_path:  Path to link to be extracted.
 *
 * @inode:        WIM inode that the link is to; inode->i_extracted_file
 *                the path to a name of the file that has already been
 *                extracted (we use this to create the hard link).
 *
 * @args:         Additional apply context, used here to keep track of
 *                the number of times creating a hard link failed due to
 *                ERROR_INVALID_FUNCTION.  This error should indicate that hard
 *                links are not supported by the volume, and we would like to
 *                warn the user a few times, but not too many times.
 *
 * Returns 0 if the hard link was successfully extracted.  Returns
 * WIMLIB_ERR_LINK (> 0) if an error occurred, other than hard links possibly
 * being unsupported by the volume.  Returns a negative value if creating the
 * hard link failed due to ERROR_INVALID_FUNCTION.
 */
static int
win32_try_hard_link(const wchar_t *output_path, const struct wim_inode *inode,
                    struct apply_args *args)
{
        DWORD err;

        /* There is a volume flag for this (FILE_SUPPORTS_HARD_LINKS),
         * but it's only available on Windows 7 and later.  So no use
         * even checking it, really.  Instead, CreateHardLinkW() will
         * apparently return ERROR_INVALID_FUNCTION if the volume does
         * not support hard links. */
        DEBUG("Creating hard link \"%ls => %ls\"",
              output_path, inode->i_extracted_file);
        if (CreateHardLinkW(output_path, inode->i_extracted_file, NULL))
                return 0;

        err = GetLastError();
        if (err != ERROR_INVALID_FUNCTION) {
                ERROR("Can't create hard link \"%ls => %ls\"",
                      output_path, inode->i_extracted_file);
                win32_error(err);
                return WIMLIB_ERR_LINK;
        } else {
                args->num_hard_links_failed++;
                if (args->num_hard_links_failed < MAX_CREATE_HARD_LINK_WARNINGS) {
                        WARNING("Can't create hard link \"%ls => %ls\":\n"
                                "          Volume does not support hard links!\n"
                                "          Falling back to extracting a copy of the file.",
                                output_path, inode->i_extracted_file);
                } else if (args->num_hard_links_failed == MAX_CREATE_HARD_LINK_WARNINGS) {
                        WARNING("Suppressing further hard linking warnings...");
                }
                return -1;
        }
}

/* Extract a file, directory, reparse point, or hard link to an
 * already-extracted file using the Win32 API */
int
win32_do_apply_dentry(const wchar_t *output_path,
                      size_t output_path_num_chars,
                      struct wim_dentry *dentry,
                      struct apply_args *args)
{
        int ret;
        struct wim_inode *inode = dentry->d_inode;

        ret = win32_check_vol_flags(output_path, args);
        if (ret)
                return ret;
        if (inode->i_nlink > 1 && inode->i_extracted_file != NULL) {
                /* Linked file, with another name already extracted.  Create a
                 * hard link. */
                ret = win32_try_hard_link(output_path, inode, args);
                if (ret >= 0)
                        return ret;
                /* Negative return value from win32_try_hard_link() indicates
                 * that hard links are probably not supported by the volume.
                 * Fall back to extracting a copy of the file. */
        }

        /* If this is a reparse point and the volume does not support reparse
         * points, just skip it completely. */
        if (inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT &&
            !(args->vol_flags & FILE_SUPPORTS_REPARSE_POINTS))
        {
                WARNING("Skipping extraction of reparse point \"%ls\":\n"
                        "          Not supported by destination filesystem",
                        output_path);
        } else {
                /* Create the file, directory, or reparse point, and extract the
                 * data streams. */
                ret = win32_extract_streams(dentry, output_path, args);
                if (ret)
                        return ret;
        }
        if (inode->i_extracted_file == NULL) {
                const struct wim_lookup_table_entry *lte;

                /* Tally bytes extracted, including all alternate data streams,
                 * unless we extracted a hard link (or, at least extracted a
                 * name that was supposed to be a hard link) */
                for (unsigned i = 0; i <= inode->i_num_ads; i++) {
                        lte = inode_stream_lte_resolved(inode, i);
                        if (lte)
                                args->progress.extract.completed_bytes +=
                                                        wim_resource_size(lte);
                }
                if (inode->i_nlink > 1) {
                        /* Save extracted path for a later call to
                         * CreateHardLinkW() if this inode has multiple links.
                         * */
                        inode->i_extracted_file = WSTRDUP(output_path);
                        if (!inode->i_extracted_file)
                                return WIMLIB_ERR_NOMEM;
                }
        }
        return 0;
}

/* Set timestamps on an extracted file using the Win32 API */
int
win32_do_apply_dentry_timestamps(const wchar_t *path,
                                 size_t path_num_chars,
                                 const struct wim_dentry *dentry,
                                 const struct apply_args *args)
{
        DWORD err;
        HANDLE h;
        const struct wim_inode *inode = dentry->d_inode;

        if (inode->i_attributes & FILE_ATTRIBUTE_REPARSE_POINT &&
            !(args->vol_flags & FILE_SUPPORTS_REPARSE_POINTS))
        {
                /* Skip reparse points not extracted */
                return 0;
        }

        /* Windows doesn't let you change the timestamps of the root directory
         * (at least on FAT, which is dumb but expected since FAT doesn't store
         * any metadata about the root directory...) */
        if (path_is_root_of_drive(path))
                return 0;

        DEBUG("Opening \"%ls\" to set timestamps", path);
        h = win32_open_existing_file(path, FILE_WRITE_ATTRIBUTES);
        if (h == INVALID_HANDLE_VALUE) {
                err = GetLastError();
                goto fail;
        }

        FILETIME creationTime = {.dwLowDateTime = inode->i_creation_time & 0xffffffff,
                                 .dwHighDateTime = inode->i_creation_time >> 32};
        FILETIME lastAccessTime = {.dwLowDateTime = inode->i_last_access_time & 0xffffffff,
                                  .dwHighDateTime = inode->i_last_access_time >> 32};
        FILETIME lastWriteTime = {.dwLowDateTime = inode->i_last_write_time & 0xffffffff,
                                  .dwHighDateTime = inode->i_last_write_time >> 32};

        DEBUG("Calling SetFileTime() on \"%ls\"", path);
        if (!SetFileTime(h, &creationTime, &lastAccessTime, &lastWriteTime)) {
                err = GetLastError();
                CloseHandle(h);
                goto fail;
        }
        DEBUG("Closing \"%ls\"", path);
        if (!CloseHandle(h)) {
                err = GetLastError();
                goto fail;
        }
        goto out;
fail:
        /* Only warn if setting timestamps failed; still return 0. */
        WARNING("Can't set timestamps on \"%ls\"", path);
        win32_error(err);
out:
        return 0;
}

/* Replacement for POSIX fsync() */
int
fsync(int fd)
{
        DWORD err;
        HANDLE h;

        h = (HANDLE)_get_osfhandle(fd);
        if (h == INVALID_HANDLE_VALUE) {
                err = GetLastError();
                ERROR("Could not get Windows handle for file descriptor");
                win32_error(err);
                errno = EBADF;
                return -1;
        }
        if (!FlushFileBuffers(h)) {
                err = GetLastError();
                ERROR("Could not flush file buffers to disk");
                win32_error(err);
                errno = EIO;
                return -1;
        }
        return 0;
}

/* Use the Win32 API to get the number of processors */
unsigned
win32_get_number_of_processors()
{
        SYSTEM_INFO sysinfo;
        GetSystemInfo(&sysinfo);
        return sysinfo.dwNumberOfProcessors;
}

/* Replacement for POSIX-2008 realpath().  Warning: partial functionality only
 * (resolved_path must be NULL).   Also I highly doubt that GetFullPathName
 * really does the right thing under all circumstances. */
wchar_t *
realpath(const wchar_t *path, wchar_t *resolved_path)
{
        DWORD ret;
        wimlib_assert(resolved_path == NULL);
        DWORD err;

        ret = GetFullPathNameW(path, 0, NULL, NULL);
        if (!ret) {
                err = GetLastError();
                goto fail_win32;
        }

        resolved_path = TMALLOC(ret);
        if (!resolved_path)
                goto out;
        ret = GetFullPathNameW(path, ret, resolved_path, NULL);
        if (!ret) {
                err = GetLastError();
                free(resolved_path);
                resolved_path = NULL;
                goto fail_win32;
        }
        goto out;
fail_win32:
        win32_error(err);
        errno = -1;
out:
        return resolved_path;
}

/* rename() on Windows fails if the destination file exists.  And we need to
 * make it work on wide characters.  Fix it. */
int
win32_rename_replacement(const wchar_t *oldpath, const wchar_t *newpath)
{
        if (MoveFileExW(oldpath, newpath, MOVEFILE_REPLACE_EXISTING)) {
                return 0;
        } else {
                /* As usual, the possible error values are not documented */
                DWORD err = GetLastError();
                ERROR("MoveFileEx(): Can't rename \"%ls\" to \"%ls\"",
                      oldpath, newpath);
                win32_error(err);
                errno = -1;
                return -1;
        }
}

/* Replacement for POSIX fnmatch() (partial functionality only) */
int
fnmatch(const wchar_t *pattern, const wchar_t *string, int flags)
{
        if (PathMatchSpecW(string, pattern))
                return 0;
        else
                return FNM_NOMATCH;
}

/* truncate() replacement */
int
win32_truncate_replacement(const wchar_t *path, off_t size)
{
        DWORD err = NO_ERROR;
        LARGE_INTEGER liOffset;

        HANDLE h = win32_open_existing_file(path, GENERIC_WRITE);
        if (h == INVALID_HANDLE_VALUE)
                goto fail;

        liOffset.QuadPart = size;
        if (!SetFilePointerEx(h, liOffset, NULL, FILE_BEGIN))
                goto fail_close_handle;

        if (!SetEndOfFile(h))
                goto fail_close_handle;
        CloseHandle(h);
        return 0;

fail_close_handle:
        err = GetLastError();
        CloseHandle(h);
fail:
        if (err == NO_ERROR)
                err = GetLastError();
        ERROR("Can't truncate \"%ls\" to %"PRIu64" bytes", path, size);
        win32_error(err);
        errno = -1;
        return -1;
}


/* This really could be replaced with _wcserror_s, but this doesn't seem to
 * actually be available in MSVCRT.DLL on Windows XP (perhaps it's statically
 * linked in by Visual Studio...?). */
extern int
win32_strerror_r_replacement(int errnum, wchar_t *buf, size_t buflen)
{
        static pthread_mutex_t strerror_lock = PTHREAD_MUTEX_INITIALIZER;

        pthread_mutex_lock(&strerror_lock);
        mbstowcs(buf, strerror(errnum), buflen);
        buf[buflen - 1] = '\0';
        pthread_mutex_unlock(&strerror_lock);
        return 0;
}

#endif /* __WIN32__ */