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   1 /*
   2  * wimboot.c
   3  *
   4  * Support for creating WIMBoot pointer files.
   5  *
   6  * See http://technet.microsoft.com/en-us/library/dn594399.aspx for general
   7  * information about WIMBoot.
   8  *
   9  * Note that WIMBoot pointer files are actually implemented on top of the
  10  * Windows Overlay File System Filter (WOF).  See wof.h for more info.
  11  */
  12
  13 /*
  14  * Copyright (C) 2014 Eric Biggers
  15  *
  16  * This file is part of wimlib, a library for working with WIM files.
  17  *
  18  * wimlib is free software; you can redistribute it and/or modify it under the
  19  * terms of the GNU General Public License as published by the Free
  20  * Software Foundation; either version 3 of the License, or (at your option)
  21  * any later version.
  22  *
  23  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
  24  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  25  * A PARTICULAR PURPOSE. See the GNU General Public License for more
  26  * details.
  27  *
  28  * You should have received a copy of the GNU General Public License
  29  * along with wimlib; if not, see http://www.gnu.org/licenses/.
  30  */
  31
  32 #ifndef __WIN32__
  33 #  error "This file contains Windows code!"
  34 #endif
  35
  36 #ifdef HAVE_CONFIG_H
  37 #  include "config.h"
  38 #endif
  39
  40 #include "wimlib/win32_common.h"
  41 #include "wimlib/win32.h"
  42 #include "wimlib/assert.h"
  43 #include "wimlib/error.h"
  44 #include "wimlib/util.h"
  45 #include "wimlib/wimboot.h"
  46 #include "wimlib/wof.h"
  47
  48 static int
  49 win32_get_drive_path(const wchar_t *file_path, wchar_t drive_path[7])
  50 {
  51         tchar *file_abspath;
  52
  53         file_abspath = realpath(file_path, NULL);
  54         if (!file_abspath)
  55                 return WIMLIB_ERR_NOMEM;
  56
  57         if (file_abspath[0] == L'\0' || file_abspath[1] != L':') {
  58                 ERROR("\"%ls\": Path format not recognized", file_abspath);
  59                 FREE(file_abspath);
  60                 return WIMLIB_ERR_UNSUPPORTED;
  61         }
  62
  63         wsprintf(drive_path, L"\\\\.\\%lc:", file_abspath[0]);
  64         FREE(file_abspath);
  65         return 0;
  66 }
  67
  68 /*
  69  * Allocate a WOF data source ID for a WIM file.
  70  *
  71  * @wim_path
  72  *      Absolute path to the WIM file.  This must include a drive letter and use
  73  *      backslash path separators.
  74  * @image
  75  *      Index of the image in the WIM being applied.
  76  * @target
  77  *      Path to the target drive.
  78  * @data_source_id_ret
  79  *      On success, an identifier for the backing WIM file will be returned
  80  *      here.
  81  *
  82  * Returns 0 on success, or a positive error code on failure.
  83  */
  84 int
  85 wimboot_alloc_data_source_id(const wchar_t *wim_path, int image,
  86                              const wchar_t *target, u64 *data_source_id_ret)
  87 {
  88         tchar drive_path[7];
  89         size_t wim_path_nchars;
  90         size_t wim_file_name_length;
  91         void *in;
  92         size_t insize;
  93         struct wof_external_info *wof_info;
  94         struct wim_provider_add_overlay_input *wim_info;
  95         HANDLE h;
  96         u64 data_source_id;
  97         DWORD bytes_returned;
  98         int ret;
  99         const wchar_t *prefix = L"\\??\\";
 100         const size_t prefix_nchars = 4;
 101
 102         ret = win32_get_drive_path(target, drive_path);
 103         if (ret)
 104                 return ret;
 105
 106         wimlib_assert(!wcschr(wim_path, L'/'));
 107         wimlib_assert(wim_path[0] != L'\0' && wim_path[1] == L':');
 108
 109         wim_path_nchars = wcslen(wim_path);
 110         wim_file_name_length = sizeof(wchar_t) *
 111                                (wim_path_nchars + prefix_nchars);
 112
 113         insize = sizeof(struct wof_external_info) +
 114                  sizeof(struct wim_provider_add_overlay_input) +
 115                  wim_file_name_length;
 116
 117         in = MALLOC(insize);
 118         if (!in) {
 119                 ret = WIMLIB_ERR_NOMEM;
 120                 goto out;
 121         }
 122
 123         wof_info = (struct wof_external_info *)in;
 124         wof_info->version = WOF_CURRENT_VERSION;
 125         wof_info->provider = WOF_PROVIDER_WIM;
 126
 127         wim_info = (struct wim_provider_add_overlay_input *)(wof_info + 1);
 128         wim_info->wim_type = WIM_BOOT_NOT_OS_WIM;
 129         wim_info->wim_index = image;
 130         wim_info->wim_file_name_offset = offsetof(struct wim_provider_add_overlay_input,
 131                                                   wim_file_name);
 132         wim_info->wim_file_name_length = wim_file_name_length;
 133         wmemcpy(&wim_info->wim_file_name[0], prefix, prefix_nchars);
 134         wmemcpy(&wim_info->wim_file_name[prefix_nchars], wim_path, wim_path_nchars);
 135
 136         h = CreateFile(drive_path, GENERIC_WRITE,
 137                        FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
 138                        NULL, OPEN_EXISTING, 0, NULL);
 139
 140         if (h == INVALID_HANDLE_VALUE) {
 141                 set_errno_from_GetLastError();
 142                 ERROR_WITH_ERRNO("Failed to open \"%ls\"", drive_path);
 143                 ret = WIMLIB_ERR_OPEN;
 144                 goto out_free_in;
 145         }
 146
 147         if (!DeviceIoControl(h, FSCTL_ADD_OVERLAY,
 148                              in, insize,
 149                              &data_source_id, sizeof(data_source_id),
 150                              &bytes_returned, NULL))
 151         {
 152                 set_errno_from_GetLastError();
 153                 ERROR_WITH_ERRNO("Failed to add overlay source \"%ls\" "
 154                                  "to volume \"%ls\"", wim_path, drive_path);
 155                 ret = WIMLIB_ERR_WIMBOOT;
 156                 goto out_close_handle;
 157         }
 158
 159         if (bytes_returned != sizeof(data_source_id)) {
 160                 set_errno_from_win32_error(ERROR_INVALID_DATA);
 161                 ret = WIMLIB_ERR_WIMBOOT;
 162                 ERROR("Unexpected result size when adding "
 163                       "overlay source \"%ls\" to volume \"%ls\"",
 164                       wim_path, drive_path);
 165                 goto out_close_handle;
 166         }
 167
 168         *data_source_id_ret = data_source_id;
 169         ret = 0;
 170
 171 out_close_handle:
 172         CloseHandle(h);
 173 out_free_in:
 174         FREE(in);
 175 out:
 176         return ret;
 177 }
 178
 179
 180 /*
 181  * Set WIMBoot information on the specified file.
 182  *
 183  * @path
 184  *      Path to extracted file (already created).
 185  * @data_source_id
 186  *      Identifier for backing WIM file.
 187  * @hash
 188  *      SHA-1 message digest of the file's unnamed data stream.
 189  *
 190  * Returns 0 on success, or a positive error code on failure.
 191  */
 192 int
 193 wimboot_set_pointer(const wchar_t *path, u64 data_source_id,
 194                     const u8 hash[20])
 195 {
 196         struct {
 197                 struct wof_external_info wof_info;
 198                 struct wim_provider_external_info wim_info;
 199         } in;
 200         HANDLE h;
 201         DWORD bytes_returned;
 202         int ret;
 203
 204         in.wof_info.version = WOF_CURRENT_VERSION;
 205         in.wof_info.provider = WOF_PROVIDER_WIM;
 206
 207         in.wim_info.version = WIM_PROVIDER_CURRENT_VERSION;
 208         in.wim_info.flags = 0;
 209         in.wim_info.data_source_id = data_source_id;
 210         memcpy(in.wim_info.resource_hash, hash, 20);
 211
 212         h = win32_open_existing_file(path, GENERIC_WRITE);
 213         if (h == INVALID_HANDLE_VALUE) {
 214                 set_errno_from_GetLastError();
 215                 ret = WIMLIB_ERR_OPEN;
 216                 goto out;
 217         }
 218
 219         if (!DeviceIoControl(h, FSCTL_SET_EXTERNAL_BACKING,
 220                              &in, sizeof(in), NULL, 0, &bytes_returned, NULL))
 221         {
 222                 set_errno_from_GetLastError();
 223                 ret = WIMLIB_ERR_WIMBOOT;
 224                 goto out_close_handle;
 225         }
 226         ret = 0;
 227 out_close_handle:
 228         CloseHandle(h);
 229 out:
 230         return ret;
 231 }