Example #1
0
    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
Example #2
0
 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