pkt

%% Copyright (c) 2009-2015, Michael Santos <michael.santos@gmail.com>
%% All rights reserved.
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%% modification, are permitted provided that the following conditions
%% are met:
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%% notice, this list of conditions and the following disclaimer.
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%% Redistributions in binary form must reproduce the above copyright
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%% Neither the name of the author nor the names of its contributors
%% may be used to endorse or promote products derived from this software
%% without specific prior written permission.
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%% "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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%% POSSIBILITY OF SUCH DAMAGE.
-module(pkt_vrrp).

-export([codec/1]).

-include("pkt_vrrp.hrl").

codec(<<Version:4, Type:4, VRID:8, Prio:8, CntIP:8, AuthType:8, AdverInt:8, Sum:16, Rest/binary>>) ->
    ASize = CntIP * 4,
    <<Addresses:ASize/binary, 0:64, Payload/binary>> = Rest, % 0:64 - Application Data {1,2}
    {#vrrp{
        version = Version,
        type = Type,
        vrid = VRID,
        priority = Prio,
        auth_type = AuthType,
        adver_int = AdverInt,
        sum = Sum,
        ip_addresses = [{A, B, C, D} || <<A:8, B:8, C:8, D:8>> <= Addresses]
    }, Payload};
codec(#vrrp{version = Version, type = Type, vrid = VRID, priority = Prio, auth_type = AuthType, adver_int = AdverInt, sum = Sum, ip_addresses = Addresses}) ->
    CntIP = length(Addresses),
    ASize = CntIP * 4,
    IPs = << <<A:8, B:8, C:8, D:8>> || {A, B, C, D} <- Addresses >>,
    <<Version:4, Type:4, VRID:8, Prio:8, CntIP:8, AuthType:8, AdverInt:8, Sum:16, IPs:ASize/binary, 0:64>>.