def parse_experimenter(reader):
experimenter, = reader.peek("!4xL")
if experimenter == 0x005c16c7: # Big Switch Networks
subtype, = reader.peek("!8xL")
elif experimenter == 0x00002320: # Nicira
subtype, = reader.peek("!8xH")
else:
raise loxi.ProtocolError("unexpected experimenter id %#x" % experimenter)
if subtype in experimenter_parsers[experimenter]:
return experimenter_parsers[experimenter][subtype](reader)
else:
raise loxi.ProtocolError("unexpected BSN experimenter subtype %#x" % subtype)
def read(self, fmt):
st = struct.Struct(fmt)
if self.offset + st.size > self.length:
raise loxi.ProtocolError("Buffer too short")
result = st.unpack_from(self.buf, self.start + self.offset)
self.offset += st.size
return result
def slice(self, length, rewind=0):
if self.offset + length - rewind > self.length:
raise loxi.ProtocolError("Buffer too short")
reader = OFReader(self.buf, self.start + self.offset - rewind, length)
reader.skip(rewind)
self.offset += length - rewind
return reader
def deserializer(reader, typ):
parser = parsers.get(typ)
if not parser:
raise loxi.ProtocolError("unknown instruction type %d" % typ)
return parser(reader)
def skip(self, length):
if self.offset + length > self.length:
raise loxi.ProtocolError("Buffer too short")
self.offset += length
def skip_align(self):
new_offset = (self.offset + 7) / 8 * 8
if new_offset > self.length:
raise loxi.ProtocolError("Buffer too short")
self.offset = new_offset
def slice(self, length):
if self.offset + length > self.length:
raise loxi.ProtocolError("Buffer too short")
reader = OFReader(self.buf, self.start + self.offset, length)
self.offset += length
return reader
def slice(self, length):
if self.offset + length > len(self.buf):
raise loxi.ProtocolError("Buffer too short")
buf = OFReader(buffer(self.buf, self.offset, length))
self.offset += length
return buf
def peek(self, fmt):
st = struct.Struct(fmt)
if self.offset + st.size > len(self.buf):
raise loxi.ProtocolError("Buffer too short")
result = st.unpack_from(self.buf, self.offset)
return result
