fhandler_registry.cc

cygwin, 著名的在win32下模拟unix操作系统的东东

  /* We get here if `buf' contains valid data.  */
  if (*buf == 0)
    strcpy (dir->__d_dirent->d_name, DEFAULT_VALUE_NAME);
  else
    strcpy (dir->__d_dirent->d_name, buf);

  dir->__d_position++;
  if (dir->__d_position & REG_ENUM_VALUES_MASK)
    dir->__d_position += 0x10000;
  res = dir->__d_dirent;
out:
  syscall_printf ("%p = readdir (%p)", &dir->__d_dirent, dir);
  return res;
}

__off64_t
fhandler_registry::telldir (DIR * dir)
{
  return dir->__d_position & REG_POSITION_MASK;
}

void
fhandler_registry::seekdir (DIR * dir, __off64_t loc)
{
  /* Unfortunately cannot simply set __d_position due to transition from sub-keys to
   * values.
   */
  rewinddir (dir);
  while (loc > (dir->__d_position & REG_POSITION_MASK))
    if (!readdir (dir))
      break;
}

void
fhandler_registry::rewinddir (DIR * dir)
{
  if (dir->__d_u.__d_data.__handle != INVALID_HANDLE_VALUE)
    {
      (void) RegCloseKey ((HKEY) dir->__d_u.__d_data.__handle);
      dir->__d_u.__d_data.__handle = INVALID_HANDLE_VALUE;
    }
  dir->__d_position = 0;
  return;
}

int
fhandler_registry::closedir (DIR * dir)
{
  int res = 0;
  if (dir->__d_u.__d_data.__handle != INVALID_HANDLE_VALUE &&
      RegCloseKey ((HKEY) dir->__d_u.__d_data.__handle) != ERROR_SUCCESS)
    {
      __seterrno ();
      res = -1;
    }
  syscall_printf ("%d = closedir (%p)", res, dir);
  return 0;
}

int
fhandler_registry::open (path_conv * pc, int flags, mode_t mode)
{
  int pathlen;
  const char *file;
  HKEY handle;

  int res = fhandler_virtual::open (pc, flags, mode);
  if (!res)
    goto out;

  const char *path;
  path = get_name () + proc_len + 1 + registry_len;
  if (!*path)
    {
      if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
	{
	  set_errno (EEXIST);
	  res = 0;
	  goto out;
	}
      else if (flags & O_WRONLY)
	{
	  set_errno (EISDIR);
	  res = 0;
	  goto out;
	}
      else
	{
	  flags |= O_DIROPEN;
	  goto success;
	}
    }
  path++;
  pathlen = strlen (path);
  file = path + pathlen - 1;
  if (SLASH_P (*file) && pathlen > 1)
    file--;
  while (!SLASH_P (*file))
    file--;
  file++;

  if (file == path)
    {
      for (int i = 0; registry_listing[i]; i++)
	if (path_prefix_p
	    (registry_listing[i], path, strlen (registry_listing[i])))
	  {
	    if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
	      {
		set_errno (EEXIST);
		res = 0;
		goto out;
	      }
	    else if (flags & O_WRONLY)
	      {
		set_errno (EISDIR);
		res = 0;
		goto out;
	      }
	    else
	      {
		flags |= O_DIROPEN;
		goto success;
	      }
	  }

      if (flags & O_CREAT)
	{
	  set_errno (EROFS);
	  res = 0;
	  goto out;
	}
      else
	{
	  set_errno (ENOENT);
	  res = 0;
	  goto out;
	}
    }

  if (flags & O_WRONLY)
    {
      set_errno (EROFS);
      res = 0;
      goto out;
    }

  handle = open_key (path, KEY_READ, true);
  if (handle == (HKEY) INVALID_HANDLE_VALUE)
    {
      res = 0;
      goto out;
    }

  set_io_handle (handle);

  if (pathmatch (file, DEFAULT_VALUE_NAME))
    value_name = cstrdup ("");
  else
    value_name = cstrdup (file);

  if (!fill_filebuf ())
    {
      RegCloseKey (handle);
      res = 0;
      goto out;
    }

  if (flags & O_APPEND)
    position = filesize;
  else
    position = 0;

success:
  res = 1;
  set_flags ((flags & ~O_TEXT) | O_BINARY);
  set_open_status ();
out:
  syscall_printf ("%d = fhandler_registry::open (%p, %d)", res, flags, mode);
  return res;
}

int
fhandler_registry::close ()
{
  int res = fhandler_virtual::close ();
  if (res != 0)
    return res;
  HKEY handle = (HKEY) get_handle ();
  if (handle != (HKEY) INVALID_HANDLE_VALUE)
    {
      if (RegCloseKey (handle) != ERROR_SUCCESS)
	{
	  __seterrno ();
	  res = -1;
	}
    }
  if (value_name)
    cfree (value_name);
  return res;
}

bool
fhandler_registry::fill_filebuf ()
{
  DWORD type, size;
  LONG error;
  HKEY handle = (HKEY) get_handle ();
  if (handle != HKEY_PERFORMANCE_DATA)
    {
      error = RegQueryValueEx (handle, value_name, NULL, &type, NULL, &size);
      if (error != ERROR_SUCCESS)
	{
	  if (error != ERROR_FILE_NOT_FOUND)
	    {
	      seterrno_from_win_error (__FILE__, __LINE__, error);
	      return false;
	    }
	  goto value_not_found;
	}
      bufalloc = size;
      filebuf = (char *) malloc (bufalloc);
      error =
	RegQueryValueEx (handle, value_name, NULL, NULL, (BYTE *) filebuf,
			 &size);
      if (error != ERROR_SUCCESS)
	{
	  seterrno_from_win_error (__FILE__, __LINE__, error);
	  return true;
	}
      filesize = size;
    }
  else
    {
      bufalloc = 0;
      do
	{
	  bufalloc += 1000;
	  filebuf = (char *) realloc (filebuf, bufalloc);
	  error = RegQueryValueEx (handle, value_name, NULL, &type,
				   (BYTE *) filebuf, &size);
	  if (error != ERROR_SUCCESS && error != ERROR_MORE_DATA)
	    {
	      if (error != ERROR_FILE_NOT_FOUND)
		{
		  seterrno_from_win_error (__FILE__, __LINE__, error);
		  return true;
		}
	      goto value_not_found;
	    }
	}
      while (error == ERROR_MORE_DATA);
      filesize = size;
    }
  return true;
value_not_found:
  DWORD buf_size = MAX_PATH;
  char buf[buf_size];
  int index = 0;
  while (ERROR_SUCCESS ==
	 (error = RegEnumKeyEx (handle, index++, buf, &buf_size, NULL, NULL,
				NULL, NULL)) || (error == ERROR_MORE_DATA))
    {
      if (pathmatch (buf, value_name))
	{
	  set_errno (EISDIR);
	  return false;
	}
      buf_size = MAX_PATH;
    }
  if (error != ERROR_NO_MORE_ITEMS)
    {
      seterrno_from_win_error (__FILE__, __LINE__, error);
      return false;
    }
  set_errno (ENOENT);
  return false;
}

/* Auxillary member function to open registry keys.  */
static HKEY
open_key (const char *name, REGSAM access, bool isValue)
{
  HKEY hKey = (HKEY) INVALID_HANDLE_VALUE;
  HKEY hParentKey = (HKEY) INVALID_HANDLE_VALUE;
  bool parentOpened = false;
  char component[MAX_PATH];

  while (*name)
    {
      const char *anchor = name;
      while (*name && !SLASH_P (*name))
	name++;
      strncpy (component, anchor, name - anchor);
      component[name - anchor] = '\0';
      if (*name)
	name++;
      if (*name == 0 && isValue == true)
	goto out;

      if (hParentKey != (HKEY) INVALID_HANDLE_VALUE)
	{
	  REGSAM effective_access = KEY_READ;
	  if ((strchr (name, '/') == NULL && isValue == true) || *name == 0)
	    effective_access = access;
	  LONG
	    error =
	    RegOpenKeyEx (hParentKey, component, 0, effective_access, &hKey);
	  if (error != ERROR_SUCCESS)
	    {
	      hKey = (HKEY) INVALID_HANDLE_VALUE;
	      seterrno_from_win_error (__FILE__, __LINE__, error);
	      return hKey;
	    }
	  if (parentOpened)
	    RegCloseKey (hParentKey);
	  hParentKey = hKey;
	  parentOpened = true;
	}
      else
	{
	  for (int i = 0; registry_listing[i]; i++)
	    if (pathmatch (component, registry_listing[i]))
	      hKey = registry_keys[i];
	  if (hKey == (HKEY) INVALID_HANDLE_VALUE)
	    return hKey;
	  hParentKey = hKey;
	}
    }
out:
  return hKey;
}