def parse(self, data, negotiated):
if not data:
return self
# We do not care if the attribute are transitive or not as we do not redistribute
flag = Attribute.Flag(ord(data[0]))
aid = Attribute.ID(ord(data[1]))
if flag & Attribute.Flag.EXTENDED_LENGTH:
length = unpack('!H', data[2:4])[0]
offset = 4
else:
length = ord(data[2])
offset = 3
data = data[offset:]
next = data[length:]
attribute = data[:length]
logger = Logger()
logger.parser(
LazyFormat(
"parsing flag %x type %02x (%s) len %02x %s" %
(flag, int(aid), aid, length, 'payload ' if length else ''),
od, data[:length]))
# remove the PARTIAL bit before comparaison if the attribute is optional
if aid in Attribute.attributes_optional:
aid &= Attribute.Flag.MASK_PARTIAL & 0xFF
# aid &= ~Attribute.Flag.PARTIAL & 0xFF # cleaner than above (python use signed integer for ~)
# handle the attribute if we know it
if Attribute.registered(aid, flag):
self.add(Attribute.unpack(aid, flag, attribute, negotiated))
return self.parse(next, negotiated)
# XXX: FIXME: we could use a fallback function here like capability
# if we know the attribute but the flag is not what the RFC says. ignore it.
if aid in Attribute.attributes_known:
logger.parser(
'invalid flag for attribute %s (flag 0x%02X, aid 0x%02X)' %
(Attribute.ID.names.get(aid, 'unset'), flag, aid))
return self.parse(next, negotiated)
# it is an unknown transitive attribute we need to pass on
if flag & Attribute.Flag.TRANSITIVE:
logger.parser(
'unknown transitive attribute (flag 0x%02X, aid 0x%02X)' %
(flag, aid))
self.add(
GenericAttribute(aid, flag | Attribute.Flag.PARTIAL,
attribute), attribute)
return self.parse(next, negotiated)
# it is an unknown non-transitive attribute we can ignore.
logger.parser(
'ignoring unknown non-transitive attribute (flag 0x%02X, aid 0x%02X)'
% (flag, aid))
return self.parse(next, negotiated)
def flag_attribute_content(data):
flag = Attribute.Flag(ord(data[0]))
attr = Attribute.ID(ord(data[1]))
if flag & Attribute.Flag.EXTENDED_LENGTH:
length = unpack('!H', data[2:4])[0]
return flag, attr, data[4:length + 4]
else:
length = ord(data[2])
return flag, attr, data[3:length + 3]
def add(self, attribute, data=None):
# we return None as attribute if the unpack code must not generate them
if attribute is None:
return
self._str = ''
self._json = ''
if attribute.MULTIPLE:
if self.has(attribute.ID):
self[attribute.ID].append(attribute)
else:
self[attribute.ID] = MultiAttributes(attribute)
else:
if attribute.ID in self:
raise Notify(
3, 0, 'multiple attribute for %s' %
str(Attribute.ID(attribute.ID)))
self[attribute.ID] = attribute
