## This file is part of Scapy ## See http://www.secdev.org/projects/scapy for more informations ## Copyright (C) Philippe Biondi ## Copyright (C) 6WIND ## This program is published under a GPLv2 license """ VRRP (Virtual Router Redundancy Protocol). """ from scapy.packet import * from scapy.fields import * from scapy.layers.inet import IP IPPROTO_VRRP=112 # RFC 3768 - Virtual Router Redundancy Protocol (VRRP) class VRRP(Packet): fields_desc = [ BitField("version" , 2, 4), BitField("type" , 1, 4), ByteField("vrid", 1), ByteField("priority", 100), FieldLenField("ipcount", None, count_of="addrlist", fmt="B"), ByteField("authtype", 0), ByteField("adv", 1), XShortField("chksum", None), FieldListField("addrlist", [], IPField("", "0.0.0.0"), count_from = lambda pkt: pkt.ipcount), IntField("auth1", 0), IntField("auth2", 0) ] def post_build(self, p, pay): if self.chksum is None: ck = checksum(p) p = p[:6]+chr(ck>>8)+chr(ck&0xff)+p[8:] return p bind_layers( IP, VRRP, proto=IPPROTO_VRRP)