vrrp_packet.hh

// -*- c-basic-offset: 4; tab-width: 8; indent-tabs-mode: t -*-
// vim:set sts=4 ts=8:

// Copyright (c) 2008-2011 XORP, Inc and Others
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License, Version 2, June
// 1991 as published by the Free Software Foundation. Redistribution
// and/or modification of this program under the terms of any other
// version of the GNU General Public License is not permitted.
// 
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. For more details,
// see the GNU General Public License, Version 2, a copy of which can be
// found in the XORP LICENSE.gpl file.
//
// XORP Inc, 2953 Bunker Hill Lane, Suite 204, Santa Clara, CA 95054, USA;
// http://xorp.net

// $XORP: xorp/vrrp/vrrp_packet.hh,v 1.5 2008/12/18 11:34:51 abittau Exp $

#ifndef __VRRP_VRRP_PACKET_HH__
#define __VRRP_VRRP_PACKET_HH__

#include "libxorp/ipv4.hh"
#include "libproto/packet.hh"

typedef vector<uint8_t> PAYLOAD;

struct VrrpHeader {
    enum Versions {
    VRRP_VERSION = 2
    };
    enum PktTypes {
    VRRP_TYPE_ADVERTISEMENT = 1
    };
    enum AuthTypes {
    VRRP_AUTH_NONE = 0
    };

    static VrrpHeader&        assign(uint8_t* data);

    static const VrrpHeader&  assign(const PAYLOAD& payload);

    uint32_t              finalize();

    void              add_ip(const IPv4& ip);

    IPv4              ip(unsigned index) const;

#if __BYTE_ORDER == __BIG_ENDIAN
    uint8_t     vh_v:4;
    uint8_t     vh_type:4;
#elif __BYTE_ORDER == __LITTLE_ENDIAN
    uint8_t     vh_type:4;
    uint8_t     vh_v:4;
#else
#error "Unknown endianness"
#endif
    uint8_t     vh_vrid;
    uint8_t     vh_priority;
    uint8_t     vh_ipcount;
    uint8_t     vh_auth;
    uint8_t     vh_interval;
    uint16_t        vh_sum;
    struct in_addr  vh_addr[0];
};

struct VrrpAuth {
    uint8_t     va_data[8];
};

#define IP_HEADER_MIN_SIZE  20
#define VRRP_MAX_PACKET_SIZE    (IP_HEADER_MIN_SIZE             \
                     + sizeof(VrrpHeader) + sizeof(VrrpAuth)    \
                 + sizeof(struct in_addr) * 255)

class VrrpPacket {
public:
    static const IPv4 mcast_group;

    VrrpPacket();

    void        set_source(const IPv4& ip);

    void        set_vrid(uint8_t vrid);

    void        set_priority(uint8_t priority);

    void        set_interval(uint8_t interval);

    void        clear_ips();

    void        add_ip(const IPv4& ip);

    void        finalize();

    const PAYLOAD&  data() const;

    uint32_t        size() const;

    void set_size(uint32_t size);

    template<class T> void set_ips(const T& ips)
    {
    clear_ips();
    for (typename T::const_iterator i = ips.begin(); i != ips.end(); ++i)
        add_ip(*i);
    }

private:
    PAYLOAD     _data;
    IpHeader4Writer _ip;
    VrrpHeader&     _vrrp;
};

#endif // __VRRP_VRRP_PACKET_HH__