def _of_message_to_object(binary_string):
"""
Map a binary string to the corresponding class.
Appropriately resolves subclasses
"""
hdr = ofp.ofp_header()
hdr.unpack(binary_string)
# FIXME: Add error detection
if not hdr.type in msg_type_subclassed:
return msg_type_to_class_map[hdr.type]()
if hdr.type == ofp.OFPT_STATS_REQUEST:
sub_hdr = ofp.ofp_stats_request()
sub_hdr.unpack(binary_string[ofp.OFP_HEADER_BYTES:])
try:
obj = stats_request_to_class_map[sub_hdr.type]()
except LookupError:
obj = None
return obj
elif hdr.type == ofp.OFPT_STATS_REPLY:
sub_hdr = ofp.ofp_stats_reply()
sub_hdr.unpack(binary_string[ofp.OFP_HEADER_BYTES:])
try:
obj = stats_reply_to_class_map[sub_hdr.type]()
except LookupError:
obj = None
return obj
elif hdr.type == ofp.OFPT_ERROR:
sub_hdr = ofp.ofp_error_msg()
sub_hdr.unpack(binary_string[ofp.OFP_HEADER_BYTES:])
return error_to_class_map[sub_hdr.type]()
else:
parse_logger.error("Cannot parse pkt to message")
return None
def of_header_parse(binary_string, raw=False):
"""
Parse only the header from an OpenFlow packet
Parses the header from a raw OpenFlow packet into a
an ofp_header Python class.
@param binary_string The packet (string) to be parsed
@param raw If true, interpret the packet as an L2 packet. Not
yet supported.
@return An ofp_header object
"""
if raw:
parse_logger.error("raw packet message parsing not supported")
return None
hdr = ofp.ofp_header()
hdr.unpack(binary_string)
return hdr
