wimlib.net Git - wimlib/blob - programs/imagex-win32.c

   1
   2 /* Replacements for functions needed specifically by the 'imagex' program in
   3  * Windows native builds; also, Windows-specific code to acquire and release
   4  * privileges needed to backup and restore files */
   5
   6 #ifndef __WIN32__
   7 #  error "This file contains Windows code"
   8 #endif
   9
  10 #include "imagex-win32.h"
  11 #include <windows.h>
  12 #include <errno.h>
  13 #include <string.h>
  14 #include <assert.h>
  15 #include <stdio.h>
  16 #include <fcntl.h>
  17 #include <io.h>
  18
  19 /* Replacement for glob() in Windows native builds that operates on wide
  20  * characters. */
  21 int
  22 win32_wglob(const wchar_t *pattern, int flags,
  23             int (*errfunc)(const wchar_t *epath, int eerrno),
  24             glob_t *pglob)
  25 {
  26         WIN32_FIND_DATAW dat;
  27         DWORD err;
  28         HANDLE hFind;
  29         int ret;
  30         size_t nspaces;
  31
  32         const wchar_t *backslash, *end_slash;
  33         size_t prefix_len;
  34
  35         backslash = wcsrchr(pattern, L'\\');
  36         end_slash = wcsrchr(pattern, L'/');
  37
  38         if (backslash > end_slash)
  39                 end_slash = backslash;
  40
  41         if (end_slash)
  42                 prefix_len = end_slash - pattern + 1;
  43         else
  44                 prefix_len = 0;
  45
  46         /* This function does not support all functionality of the POSIX glob(),
  47          * so make sure the parameters are consistent with supported
  48          * functionality. */
  49         assert(errfunc == NULL);
  50         assert((flags & GLOB_ERR) == GLOB_ERR);
  51         assert((flags & ~(GLOB_NOSORT | GLOB_ERR)) == 0);
  52
  53         hFind = FindFirstFileW(pattern, &dat);
  54         if (hFind == INVALID_HANDLE_VALUE) {
  55                 err = GetLastError();
  56                 if (err == ERROR_FILE_NOT_FOUND) {
  57                         errno = 0;
  58                         return GLOB_NOMATCH;
  59                 } else {
  60                         /* The other possible error codes for FindFirstFile()
  61                          * are undocumented. */
  62                         errno = EIO;
  63                         return GLOB_ABORTED;
  64                 }
  65         }
  66         pglob->gl_pathc = 0;
  67         pglob->gl_pathv = NULL;
  68         nspaces = 0;
  69         do {
  70                 wchar_t *path;
  71                 if (pglob->gl_pathc == nspaces) {
  72                         size_t new_nspaces;
  73                         wchar_t **pathv;
  74
  75                         new_nspaces = nspaces * 2 + 1;
  76                         pathv = realloc(pglob->gl_pathv,
  77                                         new_nspaces * sizeof(pglob->gl_pathv[0]));
  78                         if (!pathv)
  79                                 goto oom;
  80                         pglob->gl_pathv = pathv;
  81                         nspaces = new_nspaces;
  82                 }
  83                 size_t filename_len = wcslen(dat.cFileName);
  84                 size_t len_needed = prefix_len + filename_len;
  85
  86                 path = malloc((len_needed + 1) * sizeof(wchar_t));
  87                 if (!path)
  88                         goto oom;
  89
  90                 wmemcpy(path, pattern, prefix_len);
  91                 wmemcpy(path + prefix_len, dat.cFileName, filename_len + 1);
  92                 pglob->gl_pathv[pglob->gl_pathc++] = path;
  93         } while (FindNextFileW(hFind, &dat));
  94         err = GetLastError();
  95         CloseHandle(hFind);
  96         if (err == ERROR_NO_MORE_FILES) {
  97                 errno = 0;
  98                 return 0;
  99         } else {
 100                 /* Other possible error codes for FindNextFile() are
 101                  * undocumented */
 102                 errno = EIO;
 103                 ret = GLOB_ABORTED;
 104                 goto fail_globfree;
 105         }
 106 oom:
 107         CloseHandle(hFind);
 108         errno = ENOMEM;
 109         ret = GLOB_NOSPACE;
 110 fail_globfree:
 111         globfree(pglob);
 112         return ret;
 113 }
 114
 115 void
 116 globfree(glob_t *pglob)
 117 {
 118         size_t i;
 119         for (i = 0; i < pglob->gl_pathc; i++)
 120                 free(pglob->gl_pathv[i]);
 121         free(pglob->gl_pathv);
 122 }
 123
 124 static bool
 125 win32_modify_privilege(const wchar_t *privilege, bool enable)
 126 {
 127         HANDLE hToken;
 128         LUID luid;
 129         TOKEN_PRIVILEGES newState;
 130         bool ret = false;
 131
 132         if (!OpenProcessToken(GetCurrentProcess(),
 133                               TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY,
 134                               &hToken))
 135                 goto out;
 136
 137         if (!LookupPrivilegeValueW(NULL, privilege, &luid))
 138                 goto out;
 139
 140         newState.PrivilegeCount = 1;
 141         newState.Privileges[0].Luid = luid;
 142         newState.Privileges[0].Attributes = (enable ? SE_PRIVILEGE_ENABLED : 0);
 143         ret = AdjustTokenPrivileges(hToken, FALSE, &newState, 0, NULL, NULL);
 144         CloseHandle(hToken);
 145 out:
 146         if (!ret) {
 147                 fwprintf(stderr, L"WARNING: Failed to %ls privilege %s\n",
 148                         enable ? L"enable" : L"disable", privilege);
 149                 fwprintf(stderr,
 150                         L"WARNING: The program will continue, "
 151                         L"but if permission issues are\n"
 152                         L"encountered, you may need to run "
 153                         L"this program as the administrator\n");
 154         }
 155         return ret;
 156 }
 157
 158 static void
 159 win32_modify_capture_privileges(bool enable)
 160 {
 161         win32_modify_privilege(SE_BACKUP_NAME, enable);
 162         win32_modify_privilege(SE_SECURITY_NAME, enable);
 163 }
 164
 165 static void
 166 win32_modify_restore_privileges(bool enable)
 167 {
 168         win32_modify_privilege(SE_RESTORE_NAME, enable);
 169         win32_modify_privilege(SE_SECURITY_NAME, enable);
 170         win32_modify_privilege(SE_TAKE_OWNERSHIP_NAME, enable);
 171 }
 172
 173 void
 174 win32_acquire_capture_privileges(void)
 175 {
 176         win32_modify_capture_privileges(true);
 177 }
 178
 179 void
 180 win32_release_capture_privileges(void)
 181 {
 182         win32_modify_capture_privileges(false);
 183 }
 184
 185 void
 186 win32_acquire_restore_privileges(void)
 187 {
 188         win32_modify_restore_privileges(true);
 189 }
 190
 191 void
 192 win32_release_restore_privileges(void)
 193 {
 194         win32_modify_restore_privileges(false);
 195 }
 196
 197 /* Convert a string from the "current Windows codepage" to UTF-16LE. */
 198 wchar_t *
 199 win32_mbs_to_wcs(const char *mbs, size_t mbs_nbytes, size_t *num_wchars_ret)
 200 {
 201         if (mbs_nbytes > INT_MAX) {
 202                 fwprintf(stderr, L"ERROR: too much data (%zu bytes)!\n",
 203                          mbs_nbytes);
 204                 return NULL;
 205         }
 206         if (mbs_nbytes == 0) {
 207                 *num_wchars_ret = 0;
 208                 return (wchar_t*)mbs;
 209         }
 210         int len = MultiByteToWideChar(CP_ACP,
 211                                       MB_ERR_INVALID_CHARS,
 212                                       mbs,
 213                                       mbs_nbytes,
 214                                       NULL,
 215                                       0);
 216         if (len <= 0)
 217                 goto out_invalid;
 218         wchar_t *wcs = malloc(len * sizeof(wchar_t));
 219         if (!wcs) {
 220                 fwprintf(stderr, L"ERROR: out of memory!\n");
 221                 return NULL;
 222         }
 223         int len2 = MultiByteToWideChar(CP_ACP,
 224                                        MB_ERR_INVALID_CHARS,
 225                                        mbs,
 226                                        mbs_nbytes,
 227                                        wcs,
 228                                        len);
 229         if (len2 != len) {
 230                 free(wcs);
 231                 goto out_invalid;
 232         }
 233         *num_wchars_ret = len;
 234         return wcs;
 235 out_invalid:
 236         fwprintf(stderr,
 237 L"ERROR: Invalid multi-byte string in the text file you provided as input!\n"
 238 L"       Maybe try converting your text file to UTF-16LE?\n"
 239         );
 240         return NULL;
 241 }
 242
 243 static inline bool
 244 is_path_separator(wchar_t c)
 245 {
 246         return c == L'/' || c == L'\\';
 247 }
 248
 249 /* basename() (modifying, trailing-slash stripping version) for wide-character
 250  * strings. */
 251 wchar_t *
 252 win32_wbasename(wchar_t *path)
 253 {
 254         wchar_t *p = wcschr(path, L'\0');
 255
 256         p--;
 257         while (p >= path && is_path_separator(*p))
 258                 *p-- = '\0';
 259         while (p >= path && !is_path_separator(*p))
 260                 p--;
 261         p++;
 262         return p;
 263 }
 264
 265 void set_fd_to_binary_mode(int fd)
 266 {
 267         _setmode(fd, _O_BINARY);
 268 }