def serialize_static(vrrp_, prev):
if isinstance(prev, ipv4.ipv4):
assert type(vrrp_.ip_addresses[0]) == str
conv = addrconv.ipv4.text_to_bin
ip_address_pack_raw = vrrpv3._IPV4_ADDRESS_PACK_STR_RAW
elif isinstance(prev, ipv6.ipv6):
assert type(vrrp_.ip_addresses[0]) == str
conv = addrconv.ipv6.text_to_bin
ip_address_pack_raw = vrrpv3._IPV6_ADDRESS_PACK_STR_RAW
else:
raise ValueError('Unkown network layer %s' % type(prev))
ip_addresses_pack_str = '!' + ip_address_pack_raw * vrrp_.count_ip
ip_addresses_len = struct.calcsize(ip_addresses_pack_str)
vrrp_len = vrrpv3._MIN_LEN + ip_addresses_len
checksum = False
if vrrp_.checksum is None:
checksum = True
vrrp_.checksum = 0
buf = bytearray(vrrp_len)
assert vrrp_.max_adver_int <= VRRP_V3_MAX_ADVER_INT_MASK
struct.pack_into(vrrpv3._PACK_STR, buf, 0,
vrrp_to_version_type(vrrp_.version, vrrp_.type),
vrrp_.vrid, vrrp_.priority,
vrrp_.count_ip, vrrp_.max_adver_int, vrrp_.checksum)
struct.pack_into(ip_addresses_pack_str, buf, vrrpv3._MIN_LEN,
*map(lambda x: conv(x), vrrp_.ip_addresses))
if checksum:
vrrp_.checksum = packet_utils.checksum_ip(prev, len(buf), buf)
struct.pack_into(vrrpv3._CHECKSUM_PACK_STR, buf,
vrrpv3._CHECKSUM_OFFSET, vrrp_.checksum)
return buf
def checksum_ok(self, ipvx, vrrp_buf):
# There are two interpretation of IPv4 checksum
# include IPv4 pseudo header or not.
# http://www.ietf.org/mail-archive/web/vrrp/current/msg01473.html
# if not self.is_ipv6:
# return packet_utils.checksum(vrrp_buf) == 0
return packet_utils.checksum_ip(ipvx, len(self), vrrp_buf) == 0