Hullo..its me again..
i have been using Perl for 3 months now(still a novice, so please forgive me if my code looks bad)..and i'm trying to make a module..which is a Dhcpclient..(yes, there are modules in CPAN for a Dhcpclient, but for now i want to create my own module to broaden my knowledge).

Right now i am stuck and not quite sure if i am doing the right thing and before i proceed with this module i need to know if i am on the right track....
and i humbly ask for your guidance on this one so that i can achieve my goal(learning perl).

Here's my code:

package Dhcpclient;
use strict;
use warnings;

use Net::PcapUtils;
use NetPacket::Ethernet;
use NetPacket::IP;
use NetPacket::UDP;
use Net::RawIP;
use Net::DHCP::Packet;
use Net::DHCP::Constants;

sub new {
    my $class=shift;
    my $self= {};
    my %args = @_;
    bless ($self,$class);
    exists($args{Server}) ? $self->serverid($args{Server}) : $self->{S
+ERVER} = "0.0.0.0";
    exists($args{Requestip}) ? $self->requestip($args{Requestip}) : $s
+elf->{REQIP} = "0.0.0.0";
    exists($args{Releaseip}) ? $self->releaseip($args{Releaseip}) : $s
+elf->{RELIP} = "0.0.0.0";
    exists($args{State}) ? $self->state($args{State}) : $self->{STATE}
+ = "INIT";
    exists($args{Interface}) ? $self->interface($args{Interface}) : $s
+elf->{INTERFACE} = "eth0";
    exists($args{Mac}) ? $self->genmac($args{Mac}) : $self->{MACADDRES
+S} = genmac();
    return $self;
    }

sub serverid
    {
    my $self = shift;
    if (@_)
        { $self->{SERVER} = shift}
        return $self->{SERVER};
    }
sub requestip
    {
    my $self = shift;
    if (@_)
        {$self->{REQIP} = shift}
        return $self->{REQIP};
    }
sub releaseip
    {
    my $self = shift;
    if (@_)
        {$self->{RELIP} = shift}
        return $self->{RELIP};
    }
sub state
    {
    my $self = shift;
    if (@_)
        {$self->{STATE} = shift}
        return $self->{STATE};
    }
sub interface
    {
    my $self = shift;
    if (@_)
        { $self->{INTERFACE} = shift}
          return $self->{INTERFACE};
    }



sub genmac
{
my $test_mac="004d";
my $a=0;
while($a++<4)
        {
        $test_mac.= sprintf("%x",int rand 16);
        $test_mac.= sprintf("%x",int rand 16);
        }
return $test_mac;
}

sub createpacket
    {
     my $self=shift;
            my $state = $self->{STATE};
     my $p;
     my $data;     
        if ( $state eq 'Release')
            {
            $p= Net::DHCP::Packet->new(op => '1',
                           hlen=> '6',
                           htype=> '1',
                           hops => '0');

            $p->chaddr($self->{MACADDRESS});
            $p->xid(int(rand(0xFFFFFFFF)));
            $p->isDhcp();
            $p->ciaddr($self->{RELIP});
            $p->addOptionValue(DHO_DHCP_MESSAGE_TYPE(), 7);
            $p->addOptionValue(DHO_DHCP_SERVER_IDENTIFIER(), $self->{S
+ERVER});
            $data=$p->serialize();    
            return $data;        
             }
        elsif ( $state eq 'Request')
            
            {
              $p= Net::DHCP::Packet->new(op => '1',
                                                   hlen=> '6',
                                                   htype=> '1',
                                                   hops => '0');

                        $p->chaddr($self->{MACADDRESS});
                        $p->xid(int(rand(0xFFFFFFFF)));
                        $p->isDhcp();
                        $p->addOptionValue(DHO_DHCP_MESSAGE_TYPE(), 3)
+;
                        $p->addOptionValue(DHO_DHCP_SERVER_IDENTIFIER(
+), $self->{SERVER});
                        $p->addOptionValue(DHO_DHCP_REQUESTED_ADDRESS(
+), $self->{REQIP});
            $data=$p->serialize();
                        return $data;
            }    
    }

sub packetsend
    {
    my $self= shift;
    my $data=$self->createpacket();
    my $n =Net::RawIP->new({ ip=> {
                    saddr => '0.0.0.0',
                    daddr => '255.255.255.255',    
                    },
                  udp => {
                    source => 68,
                    dest => 67,
                    data => $data
                    }
                  });
    
    my $mac=$self->{MACADDRESS};
    my @macar = split //, $mac;
    my $i;
    my $macjoin;
    my $counter=0;
        foreach $i (@macar)
            {
            $macjoin.=$i;
            $counter++;
                if($counter%2==0)
                {
                $macjoin.=":";
                }
            }
    chop($macjoin);
    $n->ethnew($self->{INTERFACE});
    $n->ethset( source => $macjoin, dest => 'ff:ff:ff:ff:ff:ff');
    $n->ethsend;
    if ($self->{STATE} eq 'Request')
        {
        $self->getack();
        }
    }

sub printpacket
    {
    my $self=shift;
    my $data=$self->createpacket();
    my $p= Net::DHCP::Packet->new($data);
    print $p->toString();
    } 
    

sub getack
    {
    my $self=shift;
    my $packetcap1= Net::PcapUtils::open( FILTER =>'udp' , DEV => $sel
+f->{INTERFACE}, SNAPLEN => 400);
    my ($packetcap, %hdr)=Net::PcapUtils::next($packetcap1);
    my $ethpack=NetPacket::Ethernet->decode($packetcap);
    my $ipack=NetPacket::IP->decode($ethpack->{data});
    my $udpack=NetPacket::UDP->decode($ipack->{data});
    my $capture=Net::DHCP::Packet->new($udpack->{data});
    my $smac=sprintf ($ethpack->{src_mac});
    my $dmac=sprintf ($ethpack->{dest_mac});
    my $srcmac= sprintf("%s%s:%s%s:%s%s:%s%s:%s%s:%s%s", split//, $sma
+c);
    my $destmac= sprintf("%s%s:%s%s:%s%s:%s%s:%s%s:%s%s", split//, $dm
+ac);

    print ("====================BOOT REPLY========================\n")
+;
    print "\n";
    print $ipack->{src_ip} . "=====>" . $ipack->{dest_ip} . "(id : $ip
+ack->{id}, ttl: $ipack->{ttl})" . "\n";
    print "UDP Source: $udpack->{src_port}  ==> UDP Destination: $udpa
+ck->{dest_port} \n";
    print "UDP Length: $udpack->{len}, UDP Data Length:", length($udpa
+ck->{data})," \n";
    print "UDP Checksum: $udpack->{cksum} \n";
    print "\n";
    print "Source Mac address is : ".$srcmac."=====>";
    print "Destination Mac address is: " . $destmac."\n";
    my $ethtype=sprintf("%0.4x", $ethpack->{type});
    print "Ethertype: ". $ethtype . "\n";
    print "\n";

    print ("====================UDP PACKET========================\n")
+;
    print $capture->toString()."\n";
    }
1;
[download]

i would really appreciate any advice,comments,suggestions or opinion on what i am doing. i know i still have a lot to learn...again i humbly seek your guidance..

Thanks in advance..

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