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libuv/src/win/fs.c  view on Meta::CPAN

  assert(r == target_len);
  target[target_len] = '\0';
  *target_ptr = target;
  return 0;
}


INLINE static int fs__readlink_handle(HANDLE handle, char** target_ptr,
    uint64_t* target_len_ptr) {
  char buffer[MAXIMUM_REPARSE_DATA_BUFFER_SIZE];
  REPARSE_DATA_BUFFER* reparse_data = (REPARSE_DATA_BUFFER*) buffer;
  WCHAR* w_target;
  DWORD w_target_len;
  DWORD bytes;

  if (!DeviceIoControl(handle,
                       FSCTL_GET_REPARSE_POINT,
                       NULL,
                       0,
                       buffer,
                       sizeof buffer,
                       &bytes,
                       NULL)) {
    return -1;
  }

  if (reparse_data->ReparseTag == IO_REPARSE_TAG_SYMLINK) {
    /* Real symlink */
    w_target = reparse_data->SymbolicLinkReparseBuffer.PathBuffer +
        (reparse_data->SymbolicLinkReparseBuffer.SubstituteNameOffset /
        sizeof(WCHAR));
    w_target_len =
        reparse_data->SymbolicLinkReparseBuffer.SubstituteNameLength /
        sizeof(WCHAR);

    /* Real symlinks can contain pretty much everything, but the only thing we
     * really care about is undoing the implicit conversion to an NT namespaced
     * path that CreateSymbolicLink will perform on absolute paths. If the path
     * is win32-namespaced then the user must have explicitly made it so, and
     * we better just return the unmodified reparse data. */
    if (w_target_len >= 4 &&
        w_target[0] == L'\\' &&
        w_target[1] == L'?' &&
        w_target[2] == L'?' &&
        w_target[3] == L'\\') {
      /* Starts with \??\ */
      if (w_target_len >= 6 &&
          ((w_target[4] >= L'A' && w_target[4] <= L'Z') ||
           (w_target[4] >= L'a' && w_target[4] <= L'z')) &&
          w_target[5] == L':' &&
          (w_target_len == 6 || w_target[6] == L'\\')) {
        /* \??\<drive>:\ */
        w_target += 4;
        w_target_len -= 4;

      } else if (w_target_len >= 8 &&
                 (w_target[4] == L'U' || w_target[4] == L'u') &&
                 (w_target[5] == L'N' || w_target[5] == L'n') &&
                 (w_target[6] == L'C' || w_target[6] == L'c') &&
                 w_target[7] == L'\\') {
        /* \??\UNC\<server>\<share>\ - make sure the final path looks like
         * \\<server>\<share>\ */
        w_target += 6;
        w_target[0] = L'\\';
        w_target_len -= 6;
      }
    }

  } else if (reparse_data->ReparseTag == IO_REPARSE_TAG_MOUNT_POINT) {
    /* Junction. */
    w_target = reparse_data->MountPointReparseBuffer.PathBuffer +
        (reparse_data->MountPointReparseBuffer.SubstituteNameOffset /
        sizeof(WCHAR));
    w_target_len = reparse_data->MountPointReparseBuffer.SubstituteNameLength /
        sizeof(WCHAR);

    /* Only treat junctions that look like \??\<drive>:\ as symlink. Junctions
     * can also be used as mount points, like \??\Volume{<guid>}, but that's
     * confusing for programs since they wouldn't be able to actually
     * understand such a path when returned by uv_readlink(). UNC paths are
     * never valid for junctions so we don't care about them. */
    if (!(w_target_len >= 6 &&
          w_target[0] == L'\\' &&
          w_target[1] == L'?' &&
          w_target[2] == L'?' &&
          w_target[3] == L'\\' &&
          ((w_target[4] >= L'A' && w_target[4] <= L'Z') ||
           (w_target[4] >= L'a' && w_target[4] <= L'z')) &&
          w_target[5] == L':' &&
          (w_target_len == 6 || w_target[6] == L'\\'))) {
      SetLastError(ERROR_SYMLINK_NOT_SUPPORTED);
      return -1;
    }

    /* Remove leading \??\ */
    w_target += 4;
    w_target_len -= 4;

  } else {
    /* Reparse tag does not indicate a symlink. */
    SetLastError(ERROR_SYMLINK_NOT_SUPPORTED);
    return -1;
  }

  return fs__wide_to_utf8(w_target, w_target_len, target_ptr, target_len_ptr);
}


void fs__open(uv_fs_t* req) {
  DWORD access;
  DWORD share;
  DWORD disposition;
  DWORD attributes = 0;
  HANDLE file;
  int fd, current_umask;
  int flags = req->fs.info.file_flags;

  /* Obtain the active umask. umask() never fails and returns the previous
   * umask. */
  current_umask = umask(0);
  umask(current_umask);