| 1 | /* Work around platform bugs in stat. |
| 2 | Copyright (C) 2009-2019 Free Software Foundation, Inc. |
| 3 | |
| 4 | This program is free software: you can redistribute it and/or modify |
| 5 | it under the terms of the GNU General Public License as published by |
| 6 | the Free Software Foundation; either version 3 of the License, or |
| 7 | (at your option) any later version. |
| 8 | |
| 9 | This program is distributed in the hope that it will be useful, |
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | GNU General Public License for more details. |
| 13 | |
| 14 | You should have received a copy of the GNU General Public License |
| 15 | along with this program. If not, see <https://www.gnu.org/licenses/>. */ |
| 16 | |
| 17 | /* Written by Eric Blake and Bruno Haible. */ |
| 18 | |
| 19 | /* If the user's config.h happens to include <sys/stat.h>, let it include only |
| 20 | the system's <sys/stat.h> here, so that orig_stat doesn't recurse to |
| 21 | rpl_stat. */ |
| 22 | #define __need_system_sys_stat_h |
| 23 | #include <config.h> |
| 24 | |
| 25 | /* Get the original definition of stat. It might be defined as a macro. */ |
| 26 | #include <sys/types.h> |
| 27 | #include <sys/stat.h> |
| 28 | #undef __need_system_sys_stat_h |
| 29 | |
| 30 | #if defined _WIN32 && ! defined __CYGWIN__ |
| 31 | # define WINDOWS_NATIVE |
| 32 | #endif |
| 33 | |
| 34 | #if !defined WINDOWS_NATIVE |
| 35 | |
| 36 | static int |
| 37 | orig_stat (const char *filename, struct stat *buf) |
| 38 | { |
| 39 | return stat (filename, buf); |
| 40 | } |
| 41 | |
| 42 | #endif |
| 43 | |
| 44 | /* Specification. */ |
| 45 | #ifdef __osf__ |
| 46 | /* Write "sys/stat.h" here, not <sys/stat.h>, otherwise OSF/1 5.1 DTK cc |
| 47 | eliminates this include because of the preliminary #include <sys/stat.h> |
| 48 | above. */ |
| 49 | # include "sys/stat.h" |
| 50 | #else |
| 51 | # include <sys/stat.h> |
| 52 | #endif |
| 53 | |
| 54 | #include "stat-time.h" |
| 55 | |
| 56 | #include <errno.h> |
| 57 | #include <limits.h> |
| 58 | #include <stdbool.h> |
| 59 | #include <string.h> |
| 60 | #include "filename.h" |
| 61 | #include "malloca.h" |
| 62 | #include "verify.h" |
| 63 | |
| 64 | #ifdef WINDOWS_NATIVE |
| 65 | # define WIN32_LEAN_AND_MEAN |
| 66 | # include <windows.h> |
| 67 | # include "stat-w32.h" |
| 68 | #endif |
| 69 | |
| 70 | #ifdef WINDOWS_NATIVE |
| 71 | /* Return TRUE if the given file name denotes an UNC root. */ |
| 72 | static BOOL |
| 73 | is_unc_root (const char *rname) |
| 74 | { |
| 75 | /* Test whether it has the syntax '\\server\share'. */ |
| 76 | if (ISSLASH (rname[0]) && ISSLASH (rname[1])) |
| 77 | { |
| 78 | /* It starts with two slashes. Find the next slash. */ |
| 79 | const char *p = rname + 2; |
| 80 | const char *q = p; |
| 81 | while (*q != '\0' && !ISSLASH (*q)) |
| 82 | q++; |
| 83 | if (q > p && *q != '\0') |
| 84 | { |
| 85 | /* Found the next slash at q. */ |
| 86 | q++; |
| 87 | const char *r = q; |
| 88 | while (*r != '\0' && !ISSLASH (*r)) |
| 89 | r++; |
| 90 | if (r > q && *r == '\0') |
| 91 | return TRUE; |
| 92 | } |
| 93 | } |
| 94 | return FALSE; |
| 95 | } |
| 96 | #endif |
| 97 | |
| 98 | /* Store information about NAME into ST. Work around bugs with |
| 99 | trailing slashes. Mingw has other bugs (such as st_ino always |
| 100 | being 0 on success) which this wrapper does not work around. But |
| 101 | at least this implementation provides the ability to emulate fchdir |
| 102 | correctly. */ |
| 103 | |
| 104 | int |
| 105 | rpl_stat (char const *name, struct stat *buf) |
| 106 | { |
| 107 | #ifdef WINDOWS_NATIVE |
| 108 | /* Fill the fields ourselves, because the original stat function returns |
| 109 | values for st_atime, st_mtime, st_ctime that depend on the current time |
| 110 | zone. See |
| 111 | <https://lists.gnu.org/r/bug-gnulib/2017-04/msg00134.html> */ |
| 112 | /* XXX Should we convert to wchar_t* and prepend '\\?\', in order to work |
| 113 | around length limitations |
| 114 | <https://docs.microsoft.com/en-us/windows/desktop/FileIO/naming-a-file> ? */ |
| 115 | |
| 116 | /* POSIX <https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13> |
| 117 | specifies: "More than two leading <slash> characters shall be treated as |
| 118 | a single <slash> character." */ |
| 119 | if (ISSLASH (name[0]) && ISSLASH (name[1]) && ISSLASH (name[2])) |
| 120 | { |
| 121 | name += 2; |
| 122 | while (ISSLASH (name[1])) |
| 123 | name++; |
| 124 | } |
| 125 | |
| 126 | size_t len = strlen (name); |
| 127 | size_t drive_prefix_len = (HAS_DEVICE (name) ? 2 : 0); |
| 128 | |
| 129 | /* Remove trailing slashes (except the very first one, at position |
| 130 | drive_prefix_len), but remember their presence. */ |
| 131 | size_t rlen; |
| 132 | bool check_dir = false; |
| 133 | |
| 134 | rlen = len; |
| 135 | while (rlen > drive_prefix_len && ISSLASH (name[rlen-1])) |
| 136 | { |
| 137 | check_dir = true; |
| 138 | if (rlen == drive_prefix_len + 1) |
| 139 | break; |
| 140 | rlen--; |
| 141 | } |
| 142 | |
| 143 | /* Handle '' and 'C:'. */ |
| 144 | if (!check_dir && rlen == drive_prefix_len) |
| 145 | { |
| 146 | errno = ENOENT; |
| 147 | return -1; |
| 148 | } |
| 149 | |
| 150 | /* Handle '\\'. */ |
| 151 | if (rlen == 1 && ISSLASH (name[0]) && len >= 2) |
| 152 | { |
| 153 | errno = ENOENT; |
| 154 | return -1; |
| 155 | } |
| 156 | |
| 157 | const char *rname; |
| 158 | char *malloca_rname; |
| 159 | if (rlen == len) |
| 160 | { |
| 161 | rname = name; |
| 162 | malloca_rname = NULL; |
| 163 | } |
| 164 | else |
| 165 | { |
| 166 | malloca_rname = malloca (rlen + 1); |
| 167 | if (malloca_rname == NULL) |
| 168 | { |
| 169 | errno = ENOMEM; |
| 170 | return -1; |
| 171 | } |
| 172 | memcpy (malloca_rname, name, rlen); |
| 173 | malloca_rname[rlen] = '\0'; |
| 174 | rname = malloca_rname; |
| 175 | } |
| 176 | |
| 177 | /* There are two ways to get at the requested information: |
| 178 | - by scanning the parent directory and examining the relevant |
| 179 | directory entry, |
| 180 | - by opening the file directly. |
| 181 | The first approach fails for root directories (e.g. 'C:\') and |
| 182 | UNC root directories (e.g. '\\server\share'). |
| 183 | The second approach fails for some system files (e.g. 'C:\pagefile.sys' |
| 184 | and 'C:\hiberfil.sys'): ERROR_SHARING_VIOLATION. |
| 185 | The second approach gives more information (in particular, correct |
| 186 | st_dev, st_ino, st_nlink fields). |
| 187 | So we use the second approach and, as a fallback except for root and |
| 188 | UNC root directories, also the first approach. */ |
| 189 | { |
| 190 | int ret; |
| 191 | |
| 192 | { |
| 193 | /* Approach based on the file. */ |
| 194 | |
| 195 | /* Open a handle to the file. |
| 196 | CreateFile |
| 197 | <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-createfilea> |
| 198 | <https://docs.microsoft.com/en-us/windows/desktop/FileIO/creating-and-opening-files> */ |
| 199 | HANDLE h = |
| 200 | CreateFile (rname, |
| 201 | FILE_READ_ATTRIBUTES, |
| 202 | FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, |
| 203 | NULL, |
| 204 | OPEN_EXISTING, |
| 205 | /* FILE_FLAG_POSIX_SEMANTICS (treat file names that differ only |
| 206 | in case as different) makes sense only when applied to *all* |
| 207 | filesystem operations. */ |
| 208 | FILE_FLAG_BACKUP_SEMANTICS /* | FILE_FLAG_POSIX_SEMANTICS */, |
| 209 | NULL); |
| 210 | if (h != INVALID_HANDLE_VALUE) |
| 211 | { |
| 212 | ret = _gl_fstat_by_handle (h, rname, buf); |
| 213 | CloseHandle (h); |
| 214 | goto done; |
| 215 | } |
| 216 | } |
| 217 | |
| 218 | /* Test for root and UNC root directories. */ |
| 219 | if ((rlen == drive_prefix_len + 1 && ISSLASH (rname[drive_prefix_len])) |
| 220 | || is_unc_root (rname)) |
| 221 | goto failed; |
| 222 | |
| 223 | /* Fallback. */ |
| 224 | { |
| 225 | /* Approach based on the directory entry. */ |
| 226 | |
| 227 | if (strchr (rname, '?') != NULL || strchr (rname, '*') != NULL) |
| 228 | { |
| 229 | /* Other Windows API functions would fail with error |
| 230 | ERROR_INVALID_NAME. */ |
| 231 | if (malloca_rname != NULL) |
| 232 | freea (malloca_rname); |
| 233 | errno = ENOENT; |
| 234 | return -1; |
| 235 | } |
| 236 | |
| 237 | /* Get the details about the directory entry. This can be done through |
| 238 | FindFirstFile |
| 239 | <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-findfirstfilea> |
| 240 | <https://docs.microsoft.com/en-us/windows/desktop/api/minwinbase/ns-minwinbase-_win32_find_dataa> |
| 241 | or through |
| 242 | FindFirstFileEx with argument FindExInfoBasic |
| 243 | <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-findfirstfileexa> |
| 244 | <https://docs.microsoft.com/en-us/windows/desktop/api/minwinbase/ne-minwinbase-findex_info_levels> |
| 245 | <https://docs.microsoft.com/en-us/windows/desktop/api/minwinbase/ns-minwinbase-_win32_find_dataa> */ |
| 246 | WIN32_FIND_DATA info; |
| 247 | HANDLE h = FindFirstFile (rname, &info); |
| 248 | if (h == INVALID_HANDLE_VALUE) |
| 249 | goto failed; |
| 250 | |
| 251 | /* Test for error conditions before starting to fill *buf. */ |
| 252 | if (sizeof (buf->st_size) <= 4 && info.nFileSizeHigh > 0) |
| 253 | { |
| 254 | FindClose (h); |
| 255 | if (malloca_rname != NULL) |
| 256 | freea (malloca_rname); |
| 257 | errno = EOVERFLOW; |
| 258 | return -1; |
| 259 | } |
| 260 | |
| 261 | # if _GL_WINDOWS_STAT_INODES |
| 262 | buf->st_dev = 0; |
| 263 | # if _GL_WINDOWS_STAT_INODES == 2 |
| 264 | buf->st_ino._gl_ino[0] = buf->st_ino._gl_ino[1] = 0; |
| 265 | # else /* _GL_WINDOWS_STAT_INODES == 1 */ |
| 266 | buf->st_ino = 0; |
| 267 | # endif |
| 268 | # else |
| 269 | /* st_ino is not wide enough for identifying a file on a device. |
| 270 | Without st_ino, st_dev is pointless. */ |
| 271 | buf->st_dev = 0; |
| 272 | buf->st_ino = 0; |
| 273 | # endif |
| 274 | |
| 275 | /* st_mode. */ |
| 276 | unsigned int mode = |
| 277 | /* XXX How to handle FILE_ATTRIBUTE_REPARSE_POINT ? */ |
| 278 | ((info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) ? _S_IFDIR | S_IEXEC_UGO : _S_IFREG) |
| 279 | | S_IREAD_UGO |
| 280 | | ((info.dwFileAttributes & FILE_ATTRIBUTE_READONLY) ? 0 : S_IWRITE_UGO); |
| 281 | if (!(info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)) |
| 282 | { |
| 283 | /* Determine whether the file is executable by looking at the file |
| 284 | name suffix. */ |
| 285 | if (info.nFileSizeHigh > 0 || info.nFileSizeLow > 0) |
| 286 | { |
| 287 | const char *last_dot = NULL; |
| 288 | const char *p; |
| 289 | for (p = info.cFileName; *p != '\0'; p++) |
| 290 | if (*p == '.') |
| 291 | last_dot = p; |
| 292 | if (last_dot != NULL) |
| 293 | { |
| 294 | const char *suffix = last_dot + 1; |
| 295 | if (_stricmp (suffix, "exe") == 0 |
| 296 | || _stricmp (suffix, "bat") == 0 |
| 297 | || _stricmp (suffix, "cmd") == 0 |
| 298 | || _stricmp (suffix, "com") == 0) |
| 299 | mode |= S_IEXEC_UGO; |
| 300 | } |
| 301 | } |
| 302 | } |
| 303 | buf->st_mode = mode; |
| 304 | |
| 305 | /* st_nlink. Ignore hard links here. */ |
| 306 | buf->st_nlink = 1; |
| 307 | |
| 308 | /* There's no easy way to map the Windows SID concept to an integer. */ |
| 309 | buf->st_uid = 0; |
| 310 | buf->st_gid = 0; |
| 311 | |
| 312 | /* st_rdev is irrelevant for normal files and directories. */ |
| 313 | buf->st_rdev = 0; |
| 314 | |
| 315 | /* st_size. */ |
| 316 | if (sizeof (buf->st_size) <= 4) |
| 317 | /* Range check already done above. */ |
| 318 | buf->st_size = info.nFileSizeLow; |
| 319 | else |
| 320 | buf->st_size = ((long long) info.nFileSizeHigh << 32) | (long long) info.nFileSizeLow; |
| 321 | |
| 322 | /* st_atime, st_mtime, st_ctime. */ |
| 323 | # if _GL_WINDOWS_STAT_TIMESPEC |
| 324 | buf->st_atim = _gl_convert_FILETIME_to_timespec (&info.ftLastAccessTime); |
| 325 | buf->st_mtim = _gl_convert_FILETIME_to_timespec (&info.ftLastWriteTime); |
| 326 | buf->st_ctim = _gl_convert_FILETIME_to_timespec (&info.ftCreationTime); |
| 327 | # else |
| 328 | buf->st_atime = _gl_convert_FILETIME_to_POSIX (&info.ftLastAccessTime); |
| 329 | buf->st_mtime = _gl_convert_FILETIME_to_POSIX (&info.ftLastWriteTime); |
| 330 | buf->st_ctime = _gl_convert_FILETIME_to_POSIX (&info.ftCreationTime); |
| 331 | # endif |
| 332 | |
| 333 | FindClose (h); |
| 334 | |
| 335 | ret = 0; |
| 336 | } |
| 337 | |
| 338 | done: |
| 339 | if (ret >= 0 && check_dir && !S_ISDIR (buf->st_mode)) |
| 340 | { |
| 341 | errno = ENOTDIR; |
| 342 | ret = -1; |
| 343 | } |
| 344 | if (malloca_rname != NULL) |
| 345 | { |
| 346 | int saved_errno = errno; |
| 347 | freea (malloca_rname); |
| 348 | errno = saved_errno; |
| 349 | } |
| 350 | return ret; |
| 351 | } |
| 352 | |
| 353 | failed: |
| 354 | { |
| 355 | DWORD error = GetLastError (); |
| 356 | #if 0 |
| 357 | fprintf (stderr, "rpl_stat error 0x%x\n", (unsigned int) error); |
| 358 | #endif |
| 359 | |
| 360 | if (malloca_rname != NULL) |
| 361 | freea (malloca_rname); |
| 362 | |
| 363 | switch (error) |
| 364 | { |
| 365 | /* Some of these errors probably cannot happen with the specific flags |
| 366 | that we pass to CreateFile. But who knows... */ |
| 367 | case ERROR_FILE_NOT_FOUND: /* The last component of rname does not exist. */ |
| 368 | case ERROR_PATH_NOT_FOUND: /* Some directory component in rname does not exist. */ |
| 369 | case ERROR_BAD_PATHNAME: /* rname is such as '\\server'. */ |
| 370 | case ERROR_BAD_NET_NAME: /* rname is such as '\\server\nonexistentshare'. */ |
| 371 | case ERROR_INVALID_NAME: /* rname contains wildcards, misplaced colon, etc. */ |
| 372 | case ERROR_DIRECTORY: |
| 373 | errno = ENOENT; |
| 374 | break; |
| 375 | |
| 376 | case ERROR_ACCESS_DENIED: /* rname is such as 'C:\System Volume Information\foo'. */ |
| 377 | case ERROR_SHARING_VIOLATION: /* rname is such as 'C:\pagefile.sys' (second approach only). */ |
| 378 | /* XXX map to EACCES or EPERM? */ |
| 379 | errno = EACCES; |
| 380 | break; |
| 381 | |
| 382 | case ERROR_OUTOFMEMORY: |
| 383 | errno = ENOMEM; |
| 384 | break; |
| 385 | |
| 386 | case ERROR_WRITE_PROTECT: |
| 387 | errno = EROFS; |
| 388 | break; |
| 389 | |
| 390 | case ERROR_WRITE_FAULT: |
| 391 | case ERROR_READ_FAULT: |
| 392 | case ERROR_GEN_FAILURE: |
| 393 | errno = EIO; |
| 394 | break; |
| 395 | |
| 396 | case ERROR_BUFFER_OVERFLOW: |
| 397 | case ERROR_FILENAME_EXCED_RANGE: |
| 398 | errno = ENAMETOOLONG; |
| 399 | break; |
| 400 | |
| 401 | case ERROR_DELETE_PENDING: /* XXX map to EACCES or EPERM? */ |
| 402 | errno = EPERM; |
| 403 | break; |
| 404 | |
| 405 | default: |
| 406 | errno = EINVAL; |
| 407 | break; |
| 408 | } |
| 409 | |
| 410 | return -1; |
| 411 | } |
| 412 | #else |
| 413 | int result = orig_stat (name, buf); |
| 414 | if (result == 0) |
| 415 | { |
| 416 | # if REPLACE_FUNC_STAT_FILE |
| 417 | /* Solaris 9 mistakenly succeeds when given a non-directory with a |
| 418 | trailing slash. */ |
| 419 | if (!S_ISDIR (buf->st_mode)) |
| 420 | { |
| 421 | size_t len = strlen (name); |
| 422 | if (ISSLASH (name[len - 1])) |
| 423 | { |
| 424 | errno = ENOTDIR; |
| 425 | return -1; |
| 426 | } |
| 427 | } |
| 428 | # endif /* REPLACE_FUNC_STAT_FILE */ |
| 429 | result = stat_time_normalize (result, buf); |
| 430 | } |
| 431 | return result; |
| 432 | #endif |
| 433 | } |