/**
* Revalidates the fields cache
*
* @param header the header
*/
static void
_dbus_header_cache_revalidate (DBusHeader *header)
{
DBusTypeReader array;
DBusTypeReader reader;
int i;
i = 0;
while (i <= DBUS_HEADER_FIELD_LAST)
{
header->fields[i].value_pos = _DBUS_HEADER_FIELD_VALUE_NONEXISTENT;
++i;
}
_dbus_type_reader_init (&reader,
header->byte_order,
&_dbus_header_signature_str,
FIELDS_ARRAY_SIGNATURE_OFFSET,
&header->data,
FIELDS_ARRAY_LENGTH_OFFSET);
_dbus_type_reader_recurse (&reader, &array);
while (_dbus_type_reader_get_current_type (&array) != DBUS_TYPE_INVALID)
{
DBusTypeReader sub;
DBusTypeReader variant;
unsigned char field_code;
_dbus_type_reader_recurse (&array, &sub);
_dbus_assert (_dbus_type_reader_get_current_type (&sub) == DBUS_TYPE_BYTE);
_dbus_type_reader_read_basic (&sub, &field_code);
/* Unknown fields should be ignored */
if (field_code > DBUS_HEADER_FIELD_LAST)
goto next_field;
_dbus_type_reader_next (&sub);
_dbus_assert (_dbus_type_reader_get_current_type (&sub) == DBUS_TYPE_VARIANT);
_dbus_type_reader_recurse (&sub, &variant);
_dbus_header_cache_one (header, field_code, &variant);
next_field:
_dbus_type_reader_next (&array);
}
}
static dbus_bool_t
find_field_for_modification (DBusHeader *header,
int field,
DBusTypeReader *reader,
DBusTypeReader *realign_root)
{
dbus_bool_t retval;
retval = FALSE;
_dbus_type_reader_init (realign_root,
header->byte_order,
&_dbus_header_signature_str,
FIELDS_ARRAY_SIGNATURE_OFFSET,
&header->data,
FIELDS_ARRAY_LENGTH_OFFSET);
_dbus_type_reader_recurse (realign_root, reader);
while (_dbus_type_reader_get_current_type (reader) != DBUS_TYPE_INVALID)
{
DBusTypeReader sub;
unsigned char field_code;
_dbus_type_reader_recurse (reader, &sub);
_dbus_assert (_dbus_type_reader_get_current_type (&sub) == DBUS_TYPE_BYTE);
_dbus_type_reader_read_basic (&sub, &field_code);
if (field_code == (unsigned) field)
{
_dbus_assert (_dbus_type_reader_get_current_type (reader) == DBUS_TYPE_STRUCT);
retval = TRUE;
goto done;
}
_dbus_type_reader_next (reader);
}
done:
return retval;
}
static void
do_byteswap_test (int byte_order)
{
int sequence;
DBusString signature;
DBusString body;
int opposite_order;
if (!_dbus_string_init (&signature) || !_dbus_string_init (&body))
_dbus_assert_not_reached ("oom");
opposite_order = byte_order == DBUS_LITTLE_ENDIAN ? DBUS_BIG_ENDIAN : DBUS_LITTLE_ENDIAN;
sequence = 0;
while (dbus_internal_do_not_use_generate_bodies (sequence,
byte_order,
&signature, &body))
{
DBusString copy;
DBusTypeReader body_reader;
DBusTypeReader copy_reader;
if (!_dbus_string_init (©))
_dbus_assert_not_reached ("oom");
if (!_dbus_string_copy (&body, 0, ©, 0))
_dbus_assert_not_reached ("oom");
_dbus_marshal_byteswap (&signature, 0,
byte_order,
opposite_order,
©, 0);
_dbus_type_reader_init (&body_reader, byte_order, &signature, 0,
&body, 0);
_dbus_type_reader_init (©_reader, opposite_order, &signature, 0,
©, 0);
if (!_dbus_type_reader_equal_values (&body_reader, ©_reader))
{
_dbus_verbose_bytes_of_string (&signature, 0,
_dbus_string_get_length (&signature));
_dbus_verbose_bytes_of_string (&body, 0,
_dbus_string_get_length (&body));
_dbus_verbose_bytes_of_string (©, 0,
_dbus_string_get_length (©));
_dbus_warn ("Byte-swapped data did not have same values as original data");
_dbus_assert_not_reached ("test failed");
}
_dbus_string_free (©);
_dbus_string_set_length (&signature, 0);
_dbus_string_set_length (&body, 0);
++sequence;
}
_dbus_string_free (&signature);
_dbus_string_free (&body);
printf (" %d blocks swapped from order '%c' to '%c'\n",
sequence, byte_order, opposite_order);
}
/**
* Creates a message header from potentially-untrusted data. The
* return value is #TRUE if there was enough memory and the data was
* valid. If it returns #TRUE, the header will be created. If it
* returns #FALSE and *validity == #DBUS_VALIDITY_UNKNOWN_OOM_ERROR,
* then there wasn't enough memory. If it returns #FALSE
* and *validity != #DBUS_VALIDITY_UNKNOWN_OOM_ERROR then the data was
* invalid.
*
* The byte_order, fields_array_len, and body_len args should be from
* _dbus_header_have_message_untrusted(). Validation performed in
* _dbus_header_have_message_untrusted() is assumed to have been
* already done.
*
* @param header the header (must be initialized)
* @param mode whether to do validation
* @param validity return location for invalidity reason
* @param byte_order byte order from header
* @param fields_array_len claimed length of fields array
* @param body_len claimed length of body
* @param header_len claimed length of header
* @param str a string
* @param start start of header, 8-aligned
* @param len length of string to look at
* @returns #FALSE if no memory or data was invalid, #TRUE otherwise
*/
dbus_bool_t
_dbus_header_load (DBusHeader *header,
DBusValidationMode mode,
DBusValidity *validity,
int byte_order,
int fields_array_len,
int header_len,
int body_len,
const DBusString *str,
int start,
int len)
{
int leftover;
DBusValidity v;
DBusTypeReader reader;
DBusTypeReader array_reader;
unsigned char v_byte;
dbus_uint32_t v_uint32;
dbus_uint32_t serial;
int padding_start;
int padding_len;
int i;
_dbus_assert (start == (int) _DBUS_ALIGN_VALUE (start, 8));
_dbus_assert (header_len <= len);
_dbus_assert (_dbus_string_get_length (&header->data) == 0);
if (!_dbus_string_copy_len (str, start, header_len, &header->data, 0))
{
_dbus_verbose ("Failed to copy buffer into new header\n");
*validity = DBUS_VALIDITY_UNKNOWN_OOM_ERROR;
return FALSE;
}
if (mode == DBUS_VALIDATION_MODE_WE_TRUST_THIS_DATA_ABSOLUTELY)
{
leftover = len - header_len - body_len - start;
}
else
{
v = _dbus_validate_body_with_reason (&_dbus_header_signature_str, 0,
byte_order,
&leftover,
str, start, len);
if (v != DBUS_VALID)
{
*validity = v;
goto invalid;
}
}
_dbus_assert (leftover < len);
padding_len = header_len - (FIRST_FIELD_OFFSET + fields_array_len);
padding_start = start + FIRST_FIELD_OFFSET + fields_array_len;
_dbus_assert (start + header_len == (int) _DBUS_ALIGN_VALUE (padding_start, 8));
_dbus_assert (start + header_len == padding_start + padding_len);
if (mode != DBUS_VALIDATION_MODE_WE_TRUST_THIS_DATA_ABSOLUTELY)
{
if (!_dbus_string_validate_nul (str, padding_start, padding_len))
{
*validity = DBUS_INVALID_ALIGNMENT_PADDING_NOT_NUL;
goto invalid;
}
}
header->padding = padding_len;
if (mode == DBUS_VALIDATION_MODE_WE_TRUST_THIS_DATA_ABSOLUTELY)
{
*validity = DBUS_VALID;
return TRUE;
}
/* We now know the data is well-formed, but we have to check that
* it's valid.
*/
_dbus_type_reader_init (&reader,
byte_order,
&_dbus_header_signature_str, 0,
str, start);
/* BYTE ORDER */
_dbus_assert (_dbus_type_reader_get_current_type (&reader) == DBUS_TYPE_BYTE);
_dbus_assert (_dbus_type_reader_get_value_pos (&reader) == BYTE_ORDER_OFFSET);
_dbus_type_reader_read_basic (&reader, &v_byte);
_dbus_type_reader_next (&reader);
_dbus_assert (v_byte == byte_order);
header->byte_order = byte_order;
/* MESSAGE TYPE */
_dbus_assert (_dbus_type_reader_get_current_type (&reader) == DBUS_TYPE_BYTE);
_dbus_assert (_dbus_type_reader_get_value_pos (&reader) == TYPE_OFFSET);
_dbus_type_reader_read_basic (&reader, &v_byte);
_dbus_type_reader_next (&reader);
/* unknown message types are supposed to be ignored, so only validation here is
* that it isn't invalid
*/
if (v_byte == DBUS_MESSAGE_TYPE_INVALID)
{
*validity = DBUS_INVALID_BAD_MESSAGE_TYPE;
goto invalid;
}
/* FLAGS */
_dbus_assert (_dbus_type_reader_get_current_type (&reader) == DBUS_TYPE_BYTE);
_dbus_assert (_dbus_type_reader_get_value_pos (&reader) == FLAGS_OFFSET);
_dbus_type_reader_read_basic (&reader, &v_byte);
_dbus_type_reader_next (&reader);
/* unknown flags should be ignored */
/* PROTOCOL VERSION */
_dbus_assert (_dbus_type_reader_get_current_type (&reader) == DBUS_TYPE_BYTE);
_dbus_assert (_dbus_type_reader_get_value_pos (&reader) == VERSION_OFFSET);
_dbus_type_reader_read_basic (&reader, &v_byte);
_dbus_type_reader_next (&reader);
if (v_byte != DBUS_MAJOR_PROTOCOL_VERSION)
{
*validity = DBUS_INVALID_BAD_PROTOCOL_VERSION;
goto invalid;
}
/* BODY LENGTH */
_dbus_assert (_dbus_type_reader_get_current_type (&reader) == DBUS_TYPE_UINT32);
_dbus_assert (_dbus_type_reader_get_value_pos (&reader) == BODY_LENGTH_OFFSET);
_dbus_type_reader_read_basic (&reader, &v_uint32);
_dbus_type_reader_next (&reader);
_dbus_assert (body_len == (signed) v_uint32);
/* SERIAL */
_dbus_assert (_dbus_type_reader_get_current_type (&reader) == DBUS_TYPE_UINT32);
_dbus_assert (_dbus_type_reader_get_value_pos (&reader) == SERIAL_OFFSET);
_dbus_type_reader_read_basic (&reader, &serial);
_dbus_type_reader_next (&reader);
if (serial == 0)
{
*validity = DBUS_INVALID_BAD_SERIAL;
goto invalid;
}
_dbus_assert (_dbus_type_reader_get_current_type (&reader) == DBUS_TYPE_ARRAY);
_dbus_assert (_dbus_type_reader_get_value_pos (&reader) == FIELDS_ARRAY_LENGTH_OFFSET);
_dbus_type_reader_recurse (&reader, &array_reader);
while (_dbus_type_reader_get_current_type (&array_reader) != DBUS_TYPE_INVALID)
{
DBusTypeReader struct_reader;
DBusTypeReader variant_reader;
unsigned char field_code;
_dbus_assert (_dbus_type_reader_get_current_type (&array_reader) == DBUS_TYPE_STRUCT);
_dbus_type_reader_recurse (&array_reader, &struct_reader);
_dbus_assert (_dbus_type_reader_get_current_type (&struct_reader) == DBUS_TYPE_BYTE);
_dbus_type_reader_read_basic (&struct_reader, &field_code);
_dbus_type_reader_next (&struct_reader);
if (field_code == DBUS_HEADER_FIELD_INVALID)
{
_dbus_verbose ("invalid header field code\n");
*validity = DBUS_INVALID_HEADER_FIELD_CODE;
goto invalid;
}
if (field_code > DBUS_HEADER_FIELD_LAST)
{
_dbus_verbose ("unknown header field code %d, skipping\n",
field_code);
goto next_field;
}
_dbus_assert (_dbus_type_reader_get_current_type (&struct_reader) == DBUS_TYPE_VARIANT);
_dbus_type_reader_recurse (&struct_reader, &variant_reader);
v = load_and_validate_field (header, field_code, &variant_reader);
if (v != DBUS_VALID)
{
_dbus_verbose ("Field %d was invalid\n", field_code);
*validity = v;
goto invalid;
}
next_field:
_dbus_type_reader_next (&array_reader);
}
/* Anything we didn't fill in is now known not to exist */
i = 0;
while (i <= DBUS_HEADER_FIELD_LAST)
{
if (header->fields[i].value_pos == _DBUS_HEADER_FIELD_VALUE_UNKNOWN)
header->fields[i].value_pos = _DBUS_HEADER_FIELD_VALUE_NONEXISTENT;
++i;
}
v = check_mandatory_fields (header);
if (v != DBUS_VALID)
{
_dbus_verbose ("Mandatory fields were missing, code %d\n", v);
*validity = v;
goto invalid;
}
*validity = DBUS_VALID;
return TRUE;
invalid:
_dbus_string_set_length (&header->data, 0);
return FALSE;
}
