wimlib.net Git - wimlib/blob - src/win32_replacements.c

   1 /*
   2  * win32_replacements.c - Replacements for various functions not available on
   3  * Windows, such as fsync().
   4  */
   5
   6 /*
   7  * Copyright (C) 2013 Eric Biggers
   8  *
   9  * This file is part of wimlib, a library for working with WIM files.
  10  *
  11  * wimlib is free software; you can redistribute it and/or modify it under the
  12  * terms of the GNU General Public License as published by the Free
  13  * Software Foundation; either version 3 of the License, or (at your option)
  14  * any later version.
  15  *
  16  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
  17  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  18  * A PARTICULAR PURPOSE. See the GNU General Public License for more
  19  * details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with wimlib; if not, see http://www.gnu.org/licenses/.
  23  */
  24
  25 #ifdef __WIN32__
  26
  27 #ifdef HAVE_CONFIG_H
  28 #  include "config.h"
  29 #endif
  30
  31 #include <errno.h>
  32 #include <pthread.h>
  33 #include <shlwapi.h> /* for PathMatchSpecW() */
  34 #include "wimlib/win32_common.h"
  35
  36 #include "wimlib/assert.h"
  37 #include "wimlib/file_io.h"
  38 #include "wimlib/glob.h"
  39 #include "wimlib/error.h"
  40 #include "wimlib/util.h"
  41
  42 /* Replacement for POSIX fsync() */
  43 int
  44 fsync(int fd)
  45 {
  46         HANDLE h;
  47
  48         h = (HANDLE)_get_osfhandle(fd);
  49         if (h == INVALID_HANDLE_VALUE)
  50                 goto err;
  51         if (!FlushFileBuffers(h))
  52                 goto err_set_errno;
  53         return 0;
  54 err_set_errno:
  55         set_errno_from_GetLastError();
  56 err:
  57         return -1;
  58 }
  59
  60 /* Use the Win32 API to get the number of processors */
  61 unsigned
  62 win32_get_number_of_processors(void)
  63 {
  64         SYSTEM_INFO sysinfo;
  65         GetSystemInfo(&sysinfo);
  66         return sysinfo.dwNumberOfProcessors;
  67 }
  68
  69 /* Replacement for POSIX-2008 realpath().  Warning: partial functionality only
  70  * (resolved_path must be NULL).   Also I highly doubt that GetFullPathName
  71  * really does the right thing under all circumstances. */
  72 wchar_t *
  73 realpath(const wchar_t *path, wchar_t *resolved_path)
  74 {
  75         DWORD ret;
  76         DWORD err;
  77         wimlib_assert(resolved_path == NULL);
  78
  79         ret = GetFullPathNameW(path, 0, NULL, NULL);
  80         if (!ret) {
  81                 err = GetLastError();
  82                 goto fail_win32;
  83         }
  84
  85         resolved_path = MALLOC(ret * sizeof(wchar_t));
  86         if (!resolved_path)
  87                 goto out;
  88         ret = GetFullPathNameW(path, ret, resolved_path, NULL);
  89         if (!ret) {
  90                 err = GetLastError();
  91                 free(resolved_path);
  92                 resolved_path = NULL;
  93                 goto fail_win32;
  94         }
  95         goto out;
  96 fail_win32:
  97         set_errno_from_win32_error(err);
  98 out:
  99         return resolved_path;
 100 }
 101
 102 /* rename() on Windows fails if the destination file exists.  And we need to
 103  * make it work on wide characters.  Fix it. */
 104 int
 105 win32_rename_replacement(const wchar_t *oldpath, const wchar_t *newpath)
 106 {
 107         if (MoveFileExW(oldpath, newpath, MOVEFILE_REPLACE_EXISTING)) {
 108                 return 0;
 109         } else {
 110                 set_errno_from_GetLastError();
 111                 return -1;
 112         }
 113 }
 114
 115 /* Replacement for POSIX fnmatch() (partial functionality only) */
 116 int
 117 fnmatch(const wchar_t *pattern, const wchar_t *string, int flags)
 118 {
 119         if (PathMatchSpecW(string, pattern))
 120                 return 0;
 121         else
 122                 return FNM_NOMATCH;
 123 }
 124
 125 /* truncate() replacement */
 126 int
 127 win32_truncate_replacement(const wchar_t *path, off_t size)
 128 {
 129         DWORD err = NO_ERROR;
 130         LARGE_INTEGER liOffset;
 131
 132         HANDLE h = win32_open_existing_file(path, GENERIC_WRITE);
 133         if (h == INVALID_HANDLE_VALUE)
 134                 goto fail;
 135
 136         liOffset.QuadPart = size;
 137         if (!SetFilePointerEx(h, liOffset, NULL, FILE_BEGIN))
 138                 goto fail_close_handle;
 139
 140         if (!SetEndOfFile(h))
 141                 goto fail_close_handle;
 142         CloseHandle(h);
 143         return 0;
 144
 145 fail_close_handle:
 146         err = GetLastError();
 147         CloseHandle(h);
 148 fail:
 149         if (err == NO_ERROR)
 150                 err = GetLastError();
 151         set_errno_from_win32_error(err);
 152         return -1;
 153 }
 154
 155
 156 /* This really could be replaced with _wcserror_s, but this doesn't seem to
 157  * actually be available in MSVCRT.DLL on Windows XP (perhaps it's statically
 158  * linked in by Visual Studio...?). */
 159 extern int
 160 win32_strerror_r_replacement(int errnum, wchar_t *buf, size_t buflen)
 161 {
 162         static pthread_mutex_t strerror_lock = PTHREAD_MUTEX_INITIALIZER;
 163
 164         pthread_mutex_lock(&strerror_lock);
 165         mbstowcs(buf, strerror(errnum), buflen);
 166         buf[buflen - 1] = '\0';
 167         pthread_mutex_unlock(&strerror_lock);
 168         return 0;
 169 }
 170
 171 static int
 172 do_pread_or_pwrite(int fd, void *buf, size_t count, off_t offset,
 173                    bool is_pwrite)
 174 {
 175         HANDLE h;
 176         LARGE_INTEGER orig_offset;
 177         DWORD bytes_read_or_written;
 178         LARGE_INTEGER relative_offset;
 179         OVERLAPPED overlapped;
 180         BOOL bret;
 181
 182         h = (HANDLE)_get_osfhandle(fd);
 183         if (h == INVALID_HANDLE_VALUE)
 184                 goto err;
 185
 186         if (GetFileType(h) == FILE_TYPE_PIPE) {
 187                 errno = ESPIPE;
 188                 goto err;
 189         }
 190
 191         /* Get original position */
 192         relative_offset.QuadPart = 0;
 193         if (!SetFilePointerEx(h, relative_offset, &orig_offset, FILE_CURRENT))
 194                 goto err_set_errno;
 195
 196         memset(&overlapped, 0, sizeof(overlapped));
 197         overlapped.Offset = offset;
 198         overlapped.OffsetHigh = offset >> 32;
 199
 200         /* Do the read or write at the specified offset */
 201         if (is_pwrite)
 202                 bret = WriteFile(h, buf, count, &bytes_read_or_written, &overlapped);
 203         else
 204                 bret = ReadFile(h, buf, count, &bytes_read_or_written, &overlapped);
 205         if (!bret)
 206                 goto err_set_errno;
 207
 208         /* Restore the original position */
 209         if (!SetFilePointerEx(h, orig_offset, NULL, FILE_BEGIN))
 210                 goto err_set_errno;
 211
 212         return bytes_read_or_written;
 213 err_set_errno:
 214         set_errno_from_GetLastError();
 215 err:
 216         return -1;
 217 }
 218
 219 /* Dumb Windows implementation of pread().  It temporarily changes the file
 220  * offset, so it is not safe to use with readers/writers on the same file
 221  * descriptor.  */
 222 ssize_t
 223 pread(int fd, void *buf, size_t count, off_t offset)
 224 {
 225         return do_pread_or_pwrite(fd, buf, count, offset, false);
 226 }
 227
 228 /* Dumb Windows implementation of pwrite().  It temporarily changes the file
 229  * offset, so it is not safe to use with readers/writers on the same file
 230  * descriptor. */
 231 ssize_t
 232 pwrite(int fd, const void *buf, size_t count, off_t offset)
 233 {
 234         return do_pread_or_pwrite(fd, (void*)buf, count, offset, true);
 235 }
 236
 237 /* Dumb Windows implementation of writev().  It writes the vectors one at a
 238  * time. */
 239 ssize_t writev(int fd, const struct iovec *iov, int iovcnt)
 240 {
 241         ssize_t total_bytes_written = 0;
 242
 243         if (iovcnt <= 0) {
 244                 errno = EINVAL;
 245                 return -1;
 246         }
 247         for (int i = 0; i < iovcnt; i++) {
 248                 ssize_t bytes_written;
 249
 250                 bytes_written = write(fd, iov[i].iov_base, iov[i].iov_len);
 251                 if (bytes_written >= 0)
 252                         total_bytes_written += bytes_written;
 253                 if (bytes_written != iov[i].iov_len) {
 254                         if (total_bytes_written == 0)
 255                                 total_bytes_written = -1;
 256                         break;
 257                 }
 258         }
 259         return total_bytes_written;
 260 }
 261
 262 int
 263 win32_get_file_and_vol_ids(const wchar_t *path, u64 *ino_ret, u64 *dev_ret)
 264 {
 265         HANDLE h;
 266         BY_HANDLE_FILE_INFORMATION file_info;
 267         int ret;
 268         DWORD err;
 269
 270         h = win32_open_existing_file(path, FILE_READ_ATTRIBUTES);
 271         if (h == INVALID_HANDLE_VALUE) {
 272                 ret = WIMLIB_ERR_OPEN;
 273                 goto out;
 274         }
 275
 276         if (!GetFileInformationByHandle(h, &file_info)) {
 277                 ret = WIMLIB_ERR_STAT;
 278         } else {
 279                 *ino_ret = ((u64)file_info.nFileIndexHigh << 32) |
 280                             (u64)file_info.nFileIndexLow;
 281                 *dev_ret = file_info.dwVolumeSerialNumber;
 282                 ret = 0;
 283         }
 284         err = GetLastError();
 285         CloseHandle(h);
 286         SetLastError(err);
 287 out:
 288         set_errno_from_GetLastError();
 289         return ret;
 290 }
 291
 292 /* Replacement for glob() in Windows native builds that operates on wide
 293  * characters.  */
 294 int
 295 win32_wglob(const wchar_t *pattern, int flags,
 296             int (*errfunc)(const wchar_t *epath, int eerrno),
 297             glob_t *pglob)
 298 {
 299         WIN32_FIND_DATAW dat;
 300         DWORD err;
 301         HANDLE hFind;
 302         int ret;
 303         size_t nspaces;
 304
 305         const wchar_t *backslash, *end_slash;
 306         size_t prefix_len;
 307
 308         backslash = wcsrchr(pattern, L'\\');
 309         end_slash = wcsrchr(pattern, L'/');
 310
 311         if (backslash > end_slash)
 312                 end_slash = backslash;
 313
 314         if (end_slash)
 315                 prefix_len = end_slash - pattern + 1;
 316         else
 317                 prefix_len = 0;
 318
 319         /* This function does not support all functionality of the POSIX glob(),
 320          * so make sure the parameters are consistent with supported
 321          * functionality. */
 322         wimlib_assert(errfunc == NULL);
 323         wimlib_assert((flags & GLOB_ERR) == GLOB_ERR);
 324         wimlib_assert((flags & ~(GLOB_NOSORT | GLOB_ERR)) == 0);
 325
 326         hFind = FindFirstFileW(pattern, &dat);
 327         if (hFind == INVALID_HANDLE_VALUE) {
 328                 err = GetLastError();
 329                 if (err == ERROR_FILE_NOT_FOUND) {
 330                         errno = 0;
 331                         return GLOB_NOMATCH;
 332                 } else {
 333                         /* The other possible error codes for FindFirstFile()
 334                          * are undocumented. */
 335                         errno = EIO;
 336                         return GLOB_ABORTED;
 337                 }
 338         }
 339         pglob->gl_pathc = 0;
 340         pglob->gl_pathv = NULL;
 341         nspaces = 0;
 342         do {
 343                 wchar_t *path;
 344                 if (pglob->gl_pathc == nspaces) {
 345                         size_t new_nspaces;
 346                         wchar_t **pathv;
 347
 348                         new_nspaces = nspaces * 2 + 1;
 349                         pathv = REALLOC(pglob->gl_pathv,
 350                                         new_nspaces * sizeof(pglob->gl_pathv[0]));
 351                         if (!pathv)
 352                                 goto oom;
 353                         pglob->gl_pathv = pathv;
 354                         nspaces = new_nspaces;
 355                 }
 356                 size_t filename_len = wcslen(dat.cFileName);
 357                 size_t len_needed = prefix_len + filename_len;
 358
 359                 path = MALLOC((len_needed + 1) * sizeof(wchar_t));
 360                 if (!path)
 361                         goto oom;
 362
 363                 wmemcpy(path, pattern, prefix_len);
 364                 wmemcpy(path + prefix_len, dat.cFileName, filename_len + 1);
 365                 pglob->gl_pathv[pglob->gl_pathc++] = path;
 366         } while (FindNextFileW(hFind, &dat));
 367         err = GetLastError();
 368         CloseHandle(hFind);
 369         if (err == ERROR_NO_MORE_FILES) {
 370                 errno = 0;
 371                 return 0;
 372         } else {
 373                 /* Other possible error codes for FindNextFile() are
 374                  * undocumented */
 375                 errno = EIO;
 376                 ret = GLOB_ABORTED;
 377                 goto fail_globfree;
 378         }
 379 oom:
 380         CloseHandle(hFind);
 381         errno = ENOMEM;
 382         ret = GLOB_NOSPACE;
 383 fail_globfree:
 384         globfree(pglob);
 385         return ret;
 386 }
 387
 388 void
 389 globfree(glob_t *pglob)
 390 {
 391         size_t i;
 392         for (i = 0; i < pglob->gl_pathc; i++)
 393                 free(pglob->gl_pathv[i]);
 394         free(pglob->gl_pathv);
 395 }
 396
 397 #endif /* __WIN32__ */