# IBM(c) 2010 EPL license http://www.eclipse.org/legal/epl-v10.html
package xCAT_plugin::dhcp;

BEGIN
{
    $::XCATROOT = $ENV{'XCATROOT'} ? $ENV{'XCATROOT'} : '/opt/xcat';
}
use lib "$::XCATROOT/lib/perl";

use strict;
use IPC::Open2;
use xCAT::Table;

#use Data::Dumper;
use MIME::Base64;
use Getopt::Long;
Getopt::Long::Configure("bundling");
Getopt::Long::Configure("pass_through");
use Socket;
my $candoipv6 = eval {
    require Socket6;
    1;
};
use Sys::Syslog;
use IPC::Open2;
use xCAT::Utils;
use xCAT::TableUtils;
use xCAT::NetworkUtils qw/getipaddr/;
use xCAT::ServiceNodeUtils;
use xCAT::NodeRange;
use Fcntl ':flock';

my @aixcfg;       # hold AIX entries created by NIM
my @dhcpconf;     #Hold DHCP config file contents to be written back.
my @dhcp6conf;    #ipv6 equivalent
my @nrn;   # To hold output of networks table to be consulted throughout process
my @nrn6; #holds ip -6 route output on Linux, yeah, name doesn't make much sense now..
my $site_domain;
my @alldomains;
my $omshell;
my $omshell6;      #separate session to DHCPv6 instance of dhcp
my $statements;    #Hold custom statements to be slipped into host declarations
my $localonly;     # flag for running only on local server - needs to be global
my $callback;
my $restartdhcp;
my $restartdhcp6;
my $sitenameservers;
my $sitentpservers;
my $sitelogservers;
my $nrhash;
my $machash;
my $vpdhash;
my $iscsients;
my $nodetypeents;
my $chainents;
my $tftpdir = xCAT::TableUtils->getTftpDir();
use Math::BigInt;
my $dhcpconffile = $^O eq 'aix' ? '/etc/dhcpsd.cnf' : '/etc/dhcpd.conf';
my %dynamicranges; #track dynamic ranges defined to see if a host that resolves is actually a dynamic address
my %netcfgs;
my $distro = xCAT::Utils->osver();

# dhcp 4.x will use /etc/dhcp/dhcpd.conf as the config file
my $dhcp6conffile;
if ($^O ne 'aix' and -d "/etc/dhcp") {
    $dhcpconffile  = '/etc/dhcp/dhcpd.conf';
    $dhcp6conffile = '/etc/dhcp/dhcpd6.conf';
}
my $usingipv6;

# define usage statement
my $usage = "Usage: makedhcp -n\n\tmakedhcp -a\n\tmakedhcp -a -d\n\tmakedhcp -d noderange\n\tmakedhcp <noderange> [-s statements]\n\tmakedhcp -q\n\tmakedhcp [-h|--help]";


# is this ubuntu ?
if ($distro =~ /ubuntu.*/) {
    if (-e '/etc/dhcp/') {
        $dhcpconffile = '/etc/dhcp/dhcpd.conf';
    }
    else {
        $dhcpconffile = '/etc/dhcp3/dhcpd.conf';
    }
}

sub check_uefi_support {
    my $ntent     = shift;
    my %blacklist = (
        "win2k3.*"  => 1,
        "winxp.*"   => 1,
        "SL5.*"     => 1,
        "rhels5.*"  => 1,
        "centos5.*" => 1,
        "sl5.*"     => 1,
        "sles10.*"  => 1,
        "esxi4.*"   => 1);
    if ($ntent and $ntent->{os}) {
        foreach (keys %blacklist) {
            if ($ntent->{os} =~ /$_/) {
                return 0;
            }
        }
    }
    if ($ntent->{os} =~ /^win/ or $ntent->{os} =~ /^hyperv/) { #UEFI support is a tad different, need to punt..
        return 2;
    }
    return 1;
}

# check whether the proxydhcp has been enabled.
sub proxydhcp {
    my $nrent = shift;

    if ($nrent && defined $nrent->{'proxydhcp'} && $nrent->{'proxydhcp'} =~ /0|no|n/i) {
        return 0;
    }
    my @output = xCAT::Utils->runcmd("ps -C proxydhcp-xcat", -1);
    if (@output) {
        if (grep /proxydhcp-xcat/, @output) {
            return 1;
        }
    }

    return 0;
}

sub ipIsDynamic {

    #meant to be v4/v6 agnostic.  DHCPv6 however takes some care to allow a dynamic range to overlap static reservations
    #xCAT will for now continue to advise people to keep their nodes out of the dynamic range
    my $ip = shift;
    my $number = getipaddr($ip, GetNumber => 1);
    unless ($number) { # shouldn't be possible, but pessimistically presume it dynamically if so
        return 1;
    }
    foreach (values %dynamicranges) {
        if ($_->[0] <= $number and $_->[1] >= $number) {
            return 1;
        }
    }
    return 0;          #it isn't in any of the dynamic ranges we are aware of
}

sub handled_commands
{
    return { makedhcp => "dhcp", };
}

######################################################
# List nodes in DHCP for both IPv4 and IPv6
######################################################
sub listnode
{
    my $node     = shift;
    my $callback = shift;
    my $lines;
    my $ipaddr = "";
    my $hwaddr;
    my $nname;
    my $rsp;
    my ($OMOUT, $OMIN, $OMOUT6, $OMIN6);

    my $usingipv6;
    my $omapiuser;
    my $omapikey;

    # Collect the omapi user and key from the passwd table
    my $pwtab = xCAT::Table->new("passwd");
    my @pws = $pwtab->getAllAttribs('key', 'username', 'password', 'cryptmethod', 'authdomain', 'comments', 'disable');
    foreach (@pws) {

        # Look for the opapi entry in the passwd table
        if ($_->{key} =~ "omapi") {    #omapi key
                # save username and password for omapi connection
            $omapiuser = $_->{username};
            $omapikey  = $_->{password};
        }
    }

    # Look through the networks table for networks with IPv6 format for address
    my $nettab = xCAT::Table->new("networks");
    my @vnets = $nettab->getAllAttribs('net', 'mgtifname', 'mask', 'dynamicrange', 'nameservers', 'ddnsdomain', 'domain');
    foreach (@vnets) {
        if ($_->{net} =~ /:/) {    #IPv6 detected
            $usingipv6 = 1;
        }
    }

    # open ipv4 omshell file handles - $OMOUT will contain the response
    open2($OMOUT, $OMIN, "/usr/bin/omshell ");

    # setup omapi for the connection and check for the node requested
    print $OMIN "key "
      . $omapiuser . " \""
      . $omapikey . "\"\n";
    print $OMIN "connect\n";
    print $OMIN "new host\n";

    # specify which node we are looking up
    print $OMIN "set name = \"$node\"\n";
    print $OMIN "open\n";

    # the close will put the data into $OMOUT
    print $OMIN "close\n";
    close($OMIN);
    my $name = 0;

    # Process the output
    while (<$OMOUT>) {    # now read the output of sort(1)
        chomp $_;

        # if this line contains the node name
        if ($_ =~ $node) {

            # save the name returned
            if ($name) {
                $nname = $_;
                $nname =~ s/name = //;
                $nname =~ s/"//g;
            }
            $name = 1;
        }

        # if this line is the hardware-address line
        if ($_ =~ 'hardware-address') {

            # save the hardware address as it is with the hardware-address label
            $hwaddr = $_;
        }

        # if this line is the ip-address line
        elsif ($_ =~ 'ip-address') {

            # convert the hex IP address to a dotted decimal address for readability
            my ($ipname, $ip) = split /= /, $_;
            chomp($ip);
            my ($p1, $p2, $p3, $p4) = split(/\:/, $ip);
            my $dp1 = hex($p1);
            my $dp2 = hex($p2);
            my $dp3 = hex($p3);
            my $dp4 = hex($p4);
            $ipaddr = "ip-address = $dp1.$dp2.$dp3.$dp4";
        }
    }

    # if we collected the ip address then print out the information for this node
    if ($ipaddr) {
        push @{ $rsp->{data} }, "$nname: $ipaddr, $hwaddr";
        xCAT::MsgUtils->message("I", $rsp, $callback);
    }
    close($OMOUT);

    # if using IPv6 addresses check using omshell IPv6 port
    if ($usingipv6) {
        open2($OMOUT6, $OMIN6, "/usr/bin/omshell ");
        print $OMOUT6 "port 7912\n";
        print $OMOUT6 "connect\n";
        print $OMIN6 "key "
          . $omapiuser . " \""
          . $omapikey . "\"\n";
        print $OMIN6 "connect\n";
        print $OMIN6 "new host\n";

        # check for the node specified
        print $OMIN6 "set name = \"$node\"\n";
        print $OMIN6 "open\n";
        print $OMIN6 "close\n";
        close($OMIN6);
        $name   = 0;
        $ipaddr = "";
        while (<$OMOUT6>) {    # now read the output
            chomp $_;
            if ($_ =~ $node) {

                # save the name
                if ($name) {
                    $nname = $_;
                    $nname =~ s/name = //;
                    $nname =~ s/"//g;
                }
                $name = 1;
            }
            if ($_ =~ 'hardware-address') {

                # save the hardware-address
                $hwaddr = $_;
            }
            elsif ($_ =~ 'ip-address') {

                #save the ip address
                my ($ipname, $ipaddr) = split /= /, $_;
                chomp($ipaddr);
            }
        }

        # print the information if the ip address is found
        if ($ipaddr) {
            push @{ $rsp->{data} }, "$nname: $ipaddr, $hwaddr";
            xCAT::MsgUtils->message("I", $rsp, $callback);
        }

        # close the IPv6 output file handle
        close($OMOUT6);
    }
}

sub delnode
{
    my $node  = shift;
    my $inetn = inet_aton($node);

    my $mactab = xCAT::Table->new('mac');
    my $ent;
    if ($machash) { $ent = $machash->{$node}->[0]; }
    if ($ent and $ent->{mac})
    {
        my @macs = split(/\|/, $ent->{mac});
        my $mace;
        my $count = 0;
        foreach $mace (@macs)
        {
            my $mac;
            my $hname;
            ($mac, $hname) = split(/!/, $mace);

            unless ($hname)
            {
                $hname = $node;
            }    #Default to hostname equal to nodename
            unless ($mac) { next; }    #Skip corrupt format

            if (!grep /:/, $mac) {
                $mac = lc($mac);
                $mac =~ s/(\w{2})/$1:/g;
                $mac =~ s/:$//;
            }
            my $hostname       = $hname;
            my %client_nethash = xCAT::DBobjUtils->getNetwkInfo([$node]);
            if ($client_nethash{$node}{mgtifname} =~ /hf/)
            {
                if (scalar(@macs) > 1) {
                    if ($hname !~ /^(.*)-hf(.*)$/) {
                        $hostname = $hname . "-hf" . $count;
                    } else {
                        $hostname = $1 . "-hf" . $count;
                    }
                }
            }
            $count = $count + 2;

            unless ($hostname) { $hostname = $node; }
            print $omshell "new host\n";
            print $omshell
              "set name = \"$hostname\"\n";    #Find and destroy conflict name
            print $omshell "open\n";
            print $omshell "remove\n";
            print $omshell "close\n";

            if ($mac)
            {
                print $omshell "new host\n";
                print $omshell "set hardware-address = " . $mac
                  . "\n";                      #find and destroy mac conflict
                print $omshell "open\n";
                print $omshell "remove\n";
                print $omshell "close\n";
            }
            if ($inetn)
            {
                my $ip;
                if (inet_aton($hostname))
                {
                    $ip = inet_ntoa(inet_aton($hostname));
                }
                if ($ip)
                {
                    print $omshell "new host\n";
                    print $omshell
                      "set ip-address = $ip\n";    #find and destroy ip conflict
                    print $omshell "open\n";
                    print $omshell "remove\n";
                    print $omshell "close\n";
                }
            }
        }
    }
    print $omshell "new host\n";
    print $omshell "set name = \"$node\"\n";    #Find and destroy conflict name
    print $omshell "open\n";
    print $omshell "remove\n";
    print $omshell "close\n";
    if ($inetn)
    {
        my $ip = inet_ntoa(inet_aton($node));
        unless ($ip) { return; }
        print $omshell "new host\n";
        print $omshell "set ip-address = $ip\n";   #find and destroy ip conflict
        print $omshell "open\n";
        print $omshell "remove\n";
        print $omshell "close\n";
    }
}

sub addnode6 {

    #omshell to add host dynamically
    my $node = shift;
    unless ($vpdhash) {
        $callback->({ node => [ { name => [$node], warning => ["Skipping DHCPv6 setup due to missing vpd.uuid information."] } ] });
        return;
    }
    my $ent = $vpdhash->{$node}->[0];    #tab->getNodeAttribs($node, [qw(mac)]);
    unless ($ent and $ent->{uuid})
    {
        $callback->({ node => [ { name => [$node], warning => ["Skipping DHCPv6 setup due to missing vpd.uuid information."] } ] });
        return;
    }

    #phase 1, dynamic and static addresses, hopefully ddns-hostname works, may be tricky to do 'send hostname'
    #since FQDN is the only thing to be sent down, and that RFC clearly suggests that the client
    #assembles that data, not host
    #tricky for us since the client wouldn't know it's hostname/fqdn in advance
    #unless acquired via IPv4 first
    #don't think dhclient is smart enough to assemble advertised domain with it's own name and then
    #request FQDN update
    #goal is simple enough, we want `hostname` to look sane *and* we want DNS to look right
    my $uuid = $ent->{uuid};
    $uuid =~ s/-//g;
    $uuid =~ s/(..)/$1:/g;
    $uuid =~ s/:\z//;
    $uuid =~ s/^/00:04:/;
    my $ip = getipaddr($node);
    if ($ip and $ip =~ /:/ and not ipIsDynamic($ip)) {
        $ip = getipaddr($ip, GetNumber => 1);
        $ip = $ip->as_hex;
        $ip =~ s/^0x//;
        $ip =~ s/(..)/$1:/g;
        $ip =~ s/:\z//;
        print $omshell6 "set ip-address = $ip\n";
    } else {
        $ip = 0;
    }
    print $omshell6 "new host\n";
    print $omshell6 "set name = \"$node\"\n";    #Find and destroy conflict name
    print $omshell6 "open\n";
    print $omshell6 "remove\n";
    print $omshell6 "close\n";
    if ($ip) {
        print $omshell6 "new host\n";
        print $omshell6 "set ip-address = $ip\n";  #find and destroy ip conflict
        print $omshell6 "open\n";
        print $omshell6 "remove\n";
        print $omshell6 "close\n";
    }
    print $omshell6 "new host\n";
    print $omshell6 "set dhcp-client-identifier = " . $uuid . "\n"; #find and destroy DUID-UUID conflict
    print $omshell6 "open\n";
    print $omshell6 "remove\n";
    print $omshell6 "close\n";
    print $omshell6 "new host\n";
    print $omshell6 "set name = \"$node\"\n";
    print $omshell6 "set dhcp-client-identifier = $uuid\n";
    print $omshell6 'set statements = "ddns-hostname \"' . $node . '\";";' . "\n";

    if ($ip) {
        print $omshell6 "set ip-address = $ip\n";
    }
    print $omshell6 "create\n";
    print $omshell6 "close\n";

}

sub addnode
{

    #Use omshell to add the node.
    #the process used is blind typing commands that should work
    #it tries to delet any conflicting entries matched by name and
    #hardware address and ip address before creating a brand now one
    #unfortunate side effect: dhcpd.leases can look ugly over time, when
    #doing updates would keep it cleaner, good news, dhcpd restart cleans
    #up the lease file the way we would want anyway.
    my $node = shift;
    my $ent;
    my $nrent;
    my $chainent;
    my $ient;
    my $ntent;
    my $tftpserver;

    if ($chainents and $chainents->{$node}) {
        $chainent = $chainents->{$node}->[0];
    }
    if ($iscsients and $iscsients->{$node}) {
        $ient = $iscsients->{$node}->[0];
    }
    if ($nodetypeents and $nodetypeents->{$node}) {
        $ntent = $nodetypeents->{$node}->[0];
    }
    my $lstatements       = $statements;
    my $guess_next_server = 0;
    my $nxtsrv;
    if ($nrhash)
    {
        $nrent = $nrhash->{$node}->[0];
        if ($nrent and $nrent->{tftpserver})
        {
            #check the value of inet_ntoa(inet_aton("")),if the hostname cannot be resolved,
            #the value of inet_ntoa() will be "undef", which will cause fatal error
            my $tmp_name = inet_aton($nrent->{tftpserver});
            unless ($tmp_name) {

                #tell the reason to the user
                $callback->(
                    { error => ["Unable to resolve the tftpserver for node"], errorcode => [1] }
                );
                return;
            }
            $tftpserver = inet_ntoa($tmp_name);
            $nxtsrv     = $tftpserver;
            $lstatements =
              'next-server '
              . $tftpserver . ';'
              . $statements;
        }
        else
        {
            $guess_next_server = 1;
        }
        if ($nrent->{netboot} and $nrent->{netboot} eq 'petitboot') {
            if ($guess_next_server) {
                my $node_server = undef;
                if ($nrent->{xcatmaster}) {
                    $node_server = $nrent->{xcatmaster};
                } elsif ($nrent->{servicenode}) {
                    $node_server = $nrent->{servicenode};
                }
                unless ($node_server) {
                    my @nxtsrvd = xCAT::NetworkUtils->my_ip_facing($node);
                    unless ($nxtsrvd[0]) { $nxtsrv = $nxtsrvd[1]; }
                    elsif ($nxtsrvd[0] == 1) { $callback->({ error => [ $nxtsrvd[1] ] }); }
                    else {
                        $callback->({ error => ["Unable to determine the tftpserver for $node"], errorcode => [1] });
                        return;
                    }
                } else {
                    my $tmp_server = inet_aton($node_server);
                    unless ($tmp_server) {
                        $callback->({ error => ["Unable to resolve the tftpserver for $node"], errorcode => [1] });
                        return;
                    }
                    $nxtsrv = inet_ntoa($tmp_server);
                }
                unless ($nxtsrv) {
                    $callback->({ error => ["Unable to determine the tftpserver for $node"], errorcode => [1] });
                    return;
                }
                $guess_next_server = 0;
            }
        }

        #else {
        # $nrent = $nrtab->getNodeAttribs($node,['servicenode']);
        # if ($nrent and $nrent->{servicenode}) {
        #  $statements = 'next-server  = \"'.inet_ntoa(inet_aton($nrent->{servicenode})).'\";'.$statements;
        # }
        #}
    }
    else
    {
        $guess_next_server = 1;
    }
    unless ($machash)
    {
        $callback->(
            {
                warning => ["Unable to open mac table, it may not exist yet"]
            }
        );
        return;
    }
    $ent = $machash->{$node}->[0];    #tab->getNodeAttribs($node, [qw(mac)]);
    unless ($ent and $ent->{mac})
    {
        $callback->(
            {
                warning => ["Unable to find mac address for $node"]
            }
        );
        return;
    }
    my @macs = split(/\|/, $ent->{mac});
    my $mace;
    my $deflstaments = $lstatements;
    my $count        = 0;
    foreach $mace (@macs)
    {
        $lstatements = $deflstaments;    #force recalc on every entry
        my $mac;
        my $hname;
        $hname = "";
        ($mac, $hname) = split(/!/, $mace);
        unless ($hname)
        {
            $hname = $node;
        }                                #Default to hostname equal to nodename
        unless ($mac) { next; }          #Skip corrupt format
        my $ip = getipaddr($hname, OnlyV4 => 1);
        if ($hname eq '*NOIP*') {
            $hname = $node . "-noip" . $mac;
            $hname =~ s/://g;
            $ip = 'DENIED';

            #        } #if 'guess_next_server', inherit from the network provided value... see how this pans out
            #       if ($guess_next_server and $ip and $ip ne "DENIED")
            #       {
            #           $nxtsrv = xCAT::NetworkUtils->my_ip_facing($hname);
            #           if ($nxtsrv)
            #           {
            #               $tftpserver = $nxtsrv;
            #               $lstatements = "next-server $nxtsrv;$statements";
            #           } #of course, we set the xNBA variable to let that propogation carry forward into filename uri interpolation
        } elsif ($guess_next_server) {
            $nxtsrv = '${next-server}'; #if floating IP support, cause gPXE command-line expansion patch to drive inheritence from network
        }

        # The hostname could not be resolved, print a warning message
        if (!$ip)
        {
            $callback->(
                {
                    warning => [
"The hostname $hname of node $node could not be resolved."
                      ]
                }
            );
        }
        my $doiscsi = 0;
        if ($ient and $ient->{server} and $ient->{target}) {
            $doiscsi = 1;
            unless (defined($ient->{lun})) { #Some firmware fails to properly implement the spec, so we must explicitly say zero for such firmware
                $ient->{lun} = 0;
            }
            my $iscsirootpath = 'iscsi:' . $ient->{server} . ':6:3260:' . $ient->{lun} . ':' . $ient->{target};
            if (defined($ient->{iname})) { #Attempt to use gPXE or IBM iSCSI formats to specify the initiator
                 #This all goes on one line, but will break it out to at least be readable in here
                $lstatements = 'if option vendor-class-identifier = \"ISAN\" { ' #This is declared by IBM iSCSI initiators, will call it 'ISAN' mode
                  . 'option isan.iqn \"' . $ient->{iname} . '\"; '               #Use vendor-spcefic option to declare the expected Initiator name
                  . 'option isan.root-path \"' . $iscsirootpath . '\"; '         #We must *not* use standard root-path if using ISAN style options
                  . '} else { '
                  . 'option root-path \"' . $iscsirootpath . '\"; ' #For everything but ISAN, use standard, RFC defined behavior for root
                  . 'if exists gpxe.bus-id { ' #Since our iscsi-initiator-iqn is in no way a standardized thing, only use it for gPXE
                  . ' option iscsi-initiator-iqn \"' . $ient->{iname} . '\";' #gPXE will consider option 203 for initiator IQN
                  . '}'
                  . '}'
                  . $lstatements;
                print $lstatements;
            } else { #We stick to the good old RFC defined behavior, ISAN, gPXE, everyone should be content with this so long as no initiator name need be specified
                $lstatements = 'option root-path \"' . $iscsirootpath . '\";' . $lstatements;
            }
        }
        my $douefi = check_uefi_support($ntent);
        if ($nrent and $nrent->{netboot} and $nrent->{netboot} eq 'xnba' and $lstatements !~ /filename/) {
            if (-f "$tftpdir/xcat/xnba.kpxe") {
                if ($doiscsi and $chainent and $chainent->{currstate} and ($chainent->{currstate} eq 'iscsiboot' or $chainent->{currstate} eq 'boot')) {
                    $lstatements = 'if option client-architecture = 00:00 and not exists gpxe.bus-id { filename = \"xcat/xnba.kpxe\"; } else { filename = \"\"; } ' . $lstatements;
                } else {

                    # If proxydhcp daemon is enabled for windows deployment, do vendor-class-identifier of "PXEClient" to bump it over to proxydhcp.c
                    if (($douefi == 2 and $chainent->{currstate} =~ /^install/) or $chainent->{currstate} =~ /^winshell/) {
                        if (proxydhcp($nrent)) { #proxy dhcp required in uefi invocation
                            $lstatements = 'if option client-architecture = 00:00 or option client-architecture = 00:07 or option client-architecture = 00:09 { filename = \"\"; option vendor-class-identifier \"PXEClient\"; } else { filename = \"\"; }' . $lstatements; #If proxydhcp daemon is enable, use it.
                        } else {
                            $lstatements = 'if option user-class-identifier = \"xNBA\" and option client-architecture = 00:00 { always-broadcast on; filename = \"http://' . $nxtsrv . '/tftpboot/xcat/xnba/nodes/' . $node . '\"; } else if option client-architecture = 00:07 or option client-architecture = 00:09 { filename = \"\"; option vendor-class-identifier \"PXEClient\"; } else if option client-architecture = 00:00 { filename = \"xcat/xnba.kpxe\"; } else { filename = \"\"; }' . $lstatements; #Only PXE compliant clients should ever receive xNBA
                        }
                    } elsif ($douefi and $chainent->{currstate} ne "boot" and $chainent->{currstate} ne "iscsiboot") {
                        $lstatements = 'if option user-class-identifier = \"xNBA\" and option client-architecture = 00:00 { always-broadcast on; filename = \"http://' . $nxtsrv . '/tftpboot/xcat/xnba/nodes/' . $node . '\"; } else if option user-class-identifier = \"xNBA\" and option client-architecture = 00:09 { filename = \"http://' . $nxtsrv . '/tftpboot/xcat/xnba/nodes/' . $node . '.uefi\"; } else if option client-architecture = 00:07 { filename = \"xcat/xnba.efi\"; } else if option client-architecture = 00:00 { filename = \"xcat/xnba.kpxe\"; } else { filename = \"\"; }' . $lstatements; #Only PXE compliant clients should ever receive xNBA
                    } else {
                        $lstatements = 'if option user-class-identifier = \"xNBA\" and option client-architecture = 00:00 { filename = \"http://' . $nxtsrv . '/tftpboot/xcat/xnba/nodes/' . $node . '\"; } else if option client-architecture = 00:00 { filename = \"xcat/xnba.kpxe\"; } else { filename = \"\"; }' . $lstatements; #Only PXE compliant clients should ever receive xNBA
                    }
                }
            }    #TODO: warn when windows
        } elsif ($nrent and $nrent->{netboot} and $nrent->{netboot} eq 'pxe' and $lstatements !~ /filename/) {
            if (-f "$tftpdir/xcat/xnba.kpxe") {
                if ($doiscsi and $chainent and $chainent->{currstate} and ($chainent->{currstate} eq 'iscsiboot' or $chainent->{currstate} eq 'boot')) {
                    $lstatements = 'if exists gpxe.bus-id { filename = \"\"; } else if exists client-architecture { filename = \"xcat/xnba.kpxe\"; } ' . $lstatements;
                } else {
                    $lstatements = 'if option vendor-class-identifier = \"ScaleMP\" { filename = \"vsmp/pxelinux.0\"; } else { filename = \"pxelinux.0\"; }' . $lstatements;
                }
            }
        } elsif ($nrent and $nrent->{netboot} and $nrent->{netboot} eq 'yaboot') {
            $lstatements = 'filename = \"/yb/node/yaboot-' . $node . '\";' . $lstatements;
        } elsif ($nrent and $nrent->{netboot} and $nrent->{netboot} eq 'grub2') {
            $lstatements = 'filename = \"/boot/grub2/grub2-' . $node . '\";' . $lstatements;
        } elsif ($nrent and $nrent->{netboot} and $nrent->{netboot} eq 'petitboot') {
            $lstatements = 'option conf-file \"http://' . $nxtsrv . '/tftpboot/petitboot/' . $node . '\";' . $lstatements;
        } elsif ($nrent and $nrent->{netboot} and $nrent->{netboot} eq 'nimol') {
            $lstatements = 'supersede server.filename=\"/vios/nodes/' . $node . '\";' . $lstatements;
        }


        if ($^O eq 'aix')
        {
            addnode_aix($ip, $mac, $hname, $tftpserver);
        }
        else
        {
            if (!grep /:/, $mac) {
                $mac = lc($mac);
                $mac =~ s/(\w{2})/$1:/g;
                $mac =~ s/:$//;
            }
            my $hostname       = $hname;
            my $hardwaretype   = 1;
            my %client_nethash = xCAT::DBobjUtils->getNetwkInfo([$node]);
            if ($client_nethash{$node}{mgtifname} =~ /hf/)
            {
                $hardwaretype = 37;
                if (scalar(@macs) > 1) {
                    if ($hname !~ /^(.*)-hf(.*)$/) {
                        $hostname = $hname . "-hf" . $count;
                    } else {
                        $hostname = $1 . "-hf" . $count;
                    }
                }
            }

            #syslog("local4|err", "Setting $node ($hname|$ip) to " . $mac);
            print $omshell "new host\n";
            print $omshell
              "set name = \"$hostname\"\n";    #Find and destroy conflict name
            print $omshell "open\n";
            print $omshell "remove\n";
            print $omshell "close\n";
            if ($ip and $ip ne 'DENIED') {
                print $omshell "new host\n";
                print $omshell "set ip-address = $ip\n"; #find and destroy ip conflict
                print $omshell "open\n";
                print $omshell "remove\n";
                print $omshell "close\n";
            }
            print $omshell "new host\n";
            print $omshell "set hardware-address = " . $mac
              . "\n";    #find and destroy mac conflict
            print $omshell "open\n";
            print $omshell "remove\n";
            print $omshell "close\n";
            print $omshell "new host\n";
            print $omshell "set name = \"$hostname\"\n";
            print $omshell "set hardware-address = " . $mac . "\n";
            print $omshell "set hardware-type = $hardwaretype\n";

            if ($ip eq "DENIED")
            { #Blacklist this mac to preclude confusion, give best shot at things working
                print $omshell "set statements = \"deny booting;\"\n";
            }
            else
            {
                if ($ip and not ipIsDynamic($ip)) {
                    print $omshell "set ip-address = $ip\n";
                } else {

                    # only if when ip is not blank, blank ip warning already done earlier in the code
                    if ($ip)
                    {
                        $callback->(
                            {
                                warning => [
"The ip address $ip of node $node overlaps with the DHCP dynamic range specified in networks table, will not add this ip address into dhcpd.leases file."
                                  ]
                            }
                        );
                    }
                }
                if ($lstatements)
                {
                    $lstatements = 'ddns-hostname \"' . $node . '\"; send host-name \"' . $node . '\";' . $lstatements;

                } else {
                    $lstatements = 'ddns-hostname \"' . $node . '\"; send host-name \"' . $node . '\";';
                }
                print $omshell "set statements = \"$lstatements\"\n";
            }

            print $omshell "create\n";
            print $omshell "close\n";
            unless ($::XCATSITEVALS{externaldhcpservers}) {
                unless (grep /#definition for host $node aka host $hostname/, @dhcpconf)
                {
                    push @dhcpconf,
"#definition for host $node aka host $hostname can be found in the dhcpd.leases file (typically /var/lib/dhcpd/dhcpd.leases)\n";
                }
            }
        }
        $count = $count + 2;
    }
}

sub addrangedetection {
    my $net = shift;
    my $tranges = $net->{dynamicrange}; #temp range, the dollar sign makes it look strange
    my $trange;
    my $begin;
    my $end;
    my $myip;
    my @myipd = xCAT::NetworkUtils->my_ip_facing($net->{net});
    unless ($myipd[0]) { $myip = $myipd[1]; }

    # convert <xcatmaster> to nameserver IP
    if ($net->{nameservers} eq '<xcatmaster>')
    {
        $netcfgs{ $net->{net} }->{nameservers} = $myip;
    }
    else
    {
        $netcfgs{ $net->{net} }->{nameservers} = $net->{nameservers};
    }
    $netcfgs{ $net->{net} }->{ddnsdomain} = $net->{ddnsdomain};
    $netcfgs{ $net->{net} }->{domain}     = $net->{domain};

    unless ($netcfgs{ $net->{net} }->{nameservers}) {

        # convert <xcatmaster> to nameserver IP
        if ($::XCATSITEVALS{nameservers} eq '<xcatmaster>')
        {
            $netcfgs{ $net->{net} }->{nameservers} = $myip;
        }
        else
        {
            $netcfgs{ $net->{net} }->{nameservers} = $::XCATSITEVALS{nameservers};
        }
    }
    foreach $trange (split /;/, $tranges) {
        if ($trange =~ /[ ,-]/) {    #a range of one number to another..
            $trange =~ s/[,-]/ /g;
            $netcfgs{ $net->{net} }->{range} = $trange;
            ($begin, $end) = split / /, $trange;
            $dynamicranges{$trange} = [ getipaddr($begin, GetNumber => 1), getipaddr($end, GetNumber => 1) ];
        } elsif ($trange =~ /\//) { #a CIDR style specification for a range that could be described in subnet rules
             #we are going to assume that this is a subset of the network (it really ought to be) and therefore all zeroes or all ones is good to include
            my $prefix;
            my $suffix;
            ($prefix, $suffix) = split /\//, $trange;
            my $numbits;
            if ($prefix =~ /:/) {    #ipv6
                $netcfgs{ $net->{net} }->{range} = $trange; #we can put in dhcpv6 ranges verbatim as CIDR
                $numbits = 128;
            } else {
                $numbits = 32;
            }
            my $number = getipaddr($prefix, GetNumber => 1);
            my $highmask = Math::BigInt->new("0b" . ("1" x $suffix) . ("0" x ($numbits - $suffix)));
            my $lowmask = Math::BigInt->new("0b" . ("1" x ($numbits - $suffix)));
            $number &= $highmask;  #remove any errant high bits beyond the mask.
            $begin = $number->copy();
            $number |= $lowmask;    #get the highest number in the range,
            $end = $number->copy();
            $dynamicranges{$trange} = [ $begin, $end ];

            if ($prefix !~ /:/) {    #ipv4, must convert CIDR subset to range
                my $lowip  = inet_ntoa(pack("N*", $begin));
                my $highip = inet_ntoa(pack("N*", $end));
                $netcfgs{ $net->{net} }->{range} = "$lowip $highip";

            }
        }
    }
}
######################################################
# Add nodes into dhcpsd.cnf. For AIX only
######################################################
sub addnode_aix
{
    my $ip         = shift;
    my $mac        = shift;
    my $hname      = shift;
    my $tftpserver = shift;

    $restartdhcp = 1;

    # Format the mac address to aix
    $mac =~ s/://g;
    $mac = lc($mac);

    delnode_aix($hname);

    #Find the location to insert node
    my $isSubnetFound = 0;
    my $i;
    my $netmask;
    for ($i = 0 ; $i < scalar(@dhcpconf) ; $i++)
    {
        if ($dhcpconf[$i] =~ / ([\d\.]+)\/(\d+) ip configuration end/)
        {
            if (xCAT::NetworkUtils::isInSameSubnet($ip, $1, $2, 1))
            {
                $isSubnetFound = 1;
                $netmask       = $2;
                last;
            }
        }
    }

    # Format the netmask from AIX format (24) to Linux format (255.255.255.0)
    my $netmask_linux = xCAT::NetworkUtils::formatNetmask($netmask, 1, 0);

    # Create node section
    my @node_section = ();
    push @node_section, "        client 1 $mac $ip #node $hname start\n";
    push @node_section, "        {\n";
    push @node_section, "            option 1 $netmask_linux\n";
    push @node_section, "            option 12 $hname\n";

    #    push @node_section, "            option sa $tftpserver\n";
    #    push @node_section, "            option bf \"/tftpboot/$hname\"\n";
    push @node_section, "        } # node $hname end\n";


    if ($isSubnetFound)
    {
        splice @dhcpconf, $i, 0, @node_section;
    }
}

###################################################
# Delete nodes in dhcpsd.cnf. For AIX only
###################################################
sub delnode_aix
{
    my $hname = shift;
    my $i;
    my $node_start = 0;
    my $node_end   = 0;
    for ($i = 0 ; $i < scalar(@dhcpconf) ; $i++)
    {
        if ($dhcpconf[$i] =~ /node $hname start/)
        {
            $node_start = $i;
        }
        elsif ($dhcpconf[$i] =~ /node $hname end/)
        {
            $node_end = $i;
            last;
        }
    }
    if ($node_start && $node_end)
    {
        $restartdhcp = 1;
        splice @dhcpconf, $node_start, ($node_end - $node_start + 1);
        return 1;
    }
    else
    {
        return 0;
    }
}

############################################################
# check_options will process the options for makedhcp and
# give a usage error for any invalid options
############################################################
sub check_options
{
    my $req      = shift;
    my $opt      = shift;
    my $callback = shift;
    my $rc       = 0;

    # Exit if the packet has been preprocessed
    # Comment this line to make sure check_options can be processed on service node.
    if ($req->{_xcatpreprocessed}->[0] == 1) { return 0; }

    # display the usage if -h
    if ($opt->{h})
    {
        my $rsp = {};
        $rsp->{data}->[0] = $usage;
        xCAT::MsgUtils->message("I", $rsp, $callback, 0);
        return 0;
    }

    # if not help and not -n,  dhcpd needs to be running
    if (!($opt->{h}) && (!($opt->{n}))) {
        if (xCAT::Utils->isLinux()) {

            #my $DHCPSERVER="dhcpd";
            #if( -e "/etc/init.d/isc-dhcp-server" ){
            #       $DHCPSERVER="isc-dhcp-server";
            #}

            #my @output = xCAT::Utils->runcmd("service $DHCPSERVER status", -1);
            #if ($::RUNCMD_RC != 0)  { # not running
            my $ret = 0;
            $ret = xCAT::Utils->checkservicestatus("dhcp");
            if ($ret != 0)
            {
                my $rsp = {};
                $rsp->{data}->[0] = "dhcp server is not running.  please start the dhcp server.";
                xCAT::MsgUtils->message("E", $rsp, $callback, 1);
                return 1;
            }
        } else {    # AIX
            my @output = xCAT::Utils->runcmd("lssrc -s dhcpsd ", -1);
            if ($::RUNCMD_RC != 0) {    # not running
                my $rsp = {};
                $rsp->{data}->[0] = "dhcpsd is not running. Run startsrc -s dhcpsd  and rerun your command.";
                xCAT::MsgUtils->message("E", $rsp, $callback, 1);
                return 1;
            } else {                    # check the status
                 # the return output varies, sometime status is the third sometimes the 4th col
                if (grep /inoperative/, @output)
                {
                    my $rsp = {};
                    $rsp->{data}->[0] = "dhcpsd is not running. Run startsrc -s dhcpsd and rerun your command.";
                    xCAT::MsgUtils->message("E", $rsp, $callback, 1);
                    return 1;

                }
            }
        }
    }


    # check to see if -q is listed with any other options which is not allowed
    if ($opt->{q} and ($opt->{a} || $opt->{d} || $opt->{n} || $opt->{r} || $opt->{l} || $statements)) {
        my $rsp = {};
        $rsp->{data}->[0] = "The -q option cannot be used with other options.";
        xCAT::MsgUtils->message("E", $rsp, $callback, 1);
        return 1;
    }

    # check to see if -n is listed with any other options which is not allowed
    if ($opt->{n} and ($opt->{a} || $opt->{d} || $opt->{q} || $opt->{r} || $opt->{l} || $statements)) {
        my $rsp = {};
        $rsp->{data}->[0] = "The -n option cannot be used with other options.";
        xCAT::MsgUtils->message("E", $rsp, $callback, 1);
        return 1;
    }


    unless (($req->{arg} and (@{ $req->{arg} } > 0)) or $req->{node})
    {
        my $rsp = {};
        $rsp->{data}->[0] = $usage;
        xCAT::MsgUtils->message("I", $rsp, $callback, 1);
        return;
    }

    return 0;
}

############################################################
# preprocess_request will perform syntax checking and do basic precess checking
############################################################
sub preprocess_request
{
    my $req      = shift;
    my $callback = shift;
    my $rc       = 0;

    #>>>>>>>used for trace log>>>>>>>
    my $verbose_on_off = 0;

    Getopt::Long::Configure("bundling");
    $Getopt::Long::ignorecase = 0;
    Getopt::Long::Configure("no_pass_through");

    # Exit if the packet has been preprocessed
    if ($req->{_xcatpreprocessed}->[0] == 1) { return [$req]; }

    # Save the arguements in ARGV for GetOptions
    if   ($req && $req->{arg}) { @ARGV = @{ $req->{arg} }; }
    else                       { @ARGV = (); }

    my %opt;

    # Parse the options for makedhcp
    if (!GetOptions(
            'h|help'      => \$opt{h},
            'a'           => \$opt{a},
            'd'           => \$opt{d},
            'l|localonly' => \$localonly,
            'n'           => \$opt{n},
            'r'           => \$opt{r},
            's=s'         => \$statements,    # $statements is declared globally
            'q'           => \$opt{q},
            'V'           => \$opt{V}         #>>>>>>>used for trace log>>>>>>>
        ))
    {
        # If the arguements do not pass GetOptions then issue error message and return
        my $rsp = {};
        $rsp->{data}->[0] = $usage;
        xCAT::MsgUtils->message("E", $rsp, $callback, 1);
        return 1;
    }

    #>>>>>>>used for trace log>>>>>>>
    if ($opt{V}) { $verbose_on_off = 1; }

    # check the syntax
    $rc = check_options($req, \%opt, $callback);
    if ($rc) {
        xCAT::MsgUtils->trace($verbose_on_off, "e", "dhcp: command syntax error");
        return [];
    }

    my $snonly  = 0;
    my @entries = xCAT::TableUtils->get_site_attribute("disjointdhcps");
    my $t_entry = $entries[0];
    if (defined($t_entry)) {
        $snonly = $t_entry;
    }
    xCAT::MsgUtils->trace($verbose_on_off, "d", "dhcp: disjointdhcps=$t_entry");
    my @requests     = ();
    my $hasHierarchy = 0;

    my @nodes = ();

    # if the new option is not specified
    if (!$opt{n}) {

        # save the node names specified
        if ($req->{node}) {
            @nodes = @{ $req->{node} };
        }

        # if option all
        elsif ($opt{a}) {

            # if option delete - Delete all node entries, that were added by xCAT, from the DHCP server configuration.
            if ($opt{d})
            {
                my $nodelist = xCAT::Table->new('nodelist');
                my @entries  = ($nodelist->getAllNodeAttribs([qw(node)]));
                foreach (@entries)
                {
                    push @nodes, $_->{node};
                }
            }

            # Delete not specified so only add - Define all nodes to the DHCP server
            else
            {
                my $mactab  = xCAT::Table->new('mac');
                my @entries = ();
                if ($mactab) {
                    @entries = ($mactab->getAllNodeAttribs([qw(mac)]));
                }
                foreach (@entries)
                {
                    push @nodes, $_->{node};
                }
            }
        }    # end - if -a

        # don't put compute node entries in for AIX nodes
        # this is handled by NIM - duplicate entires will cause
        # an error
        if ($^O eq 'aix') {
            my @tmplist;
            my $Imsg;
            foreach my $n (@nodes)
            {
                # get the nodetype for each node
                my $ntable = xCAT::Table->new('nodetype');
                if ($ntable) {
                    my $mytype = $ntable->getNodeAttribs($n, ['nodetype']);
                    if ($mytype->{nodetype} =~ /osi/) {
                        $Imsg++;
                    }

                    # if its aix and not "osi" then add it to the list of nodes
                    unless ($mytype->{nodetype} =~ /osi/) {
                        push @tmplist, $n;
                    }
                }
            }

            # replace nodes with the tmplist of nodes that are not osi nodetype
            @nodes = @tmplist;

            # if any nodes were found with a ndoetype of osi - issue message that they are handled by NIM
            if ($Imsg) {
                my $rsp;
                push @{ $rsp->{data} }, "AIX nodes with a nodetype of \'osi\' will not be added to the dhcp configuration file.  This is handled by NIM.\n";
                xCAT::MsgUtils->message("I", $rsp, $callback);
            }
        }
    }

    #>>>>>>>used for trace log>>>>>>>
    my $str_node = join(" ", @nodes);
    xCAT::MsgUtils->trace($verbose_on_off, "d", "dhcp: nodes are $str_node");

    # If service node and not -n option
    if (($snonly == 1) && (!$opt{n})) {

        # if a list of nodes are specified
        if (@nodes > 0) {

            # get the hash of service nodes
            my $sn_hash = xCAT::ServiceNodeUtils->getSNformattedhash(\@nodes, "xcat", "MN");

            # if processing only on the local host
            if ($localonly) {

                #check if this node is the service node for any input node
                my @hostinfo = xCAT::NetworkUtils->determinehostname();
                my %iphash   = ();

                # flag the hostnames in iphash
                foreach (@hostinfo) { $iphash{$_} = 1; }

                # compare the service node hash with the iphash - a match adds this service node
                foreach (keys %$sn_hash) {
                    if (exists($iphash{$_})) {
                        my $reqcopy = {%$req};
                        $reqcopy->{'node'}                 = $sn_hash->{$_};
                        $reqcopy->{'_xcatdest'}            = $_;
                        $reqcopy->{_xcatpreprocessed}->[0] = 1;
                        push @requests, $reqcopy;
                    }
                }
            } else {

                # check to see if dhcp is running on service nodes
                my @sn = xCAT::ServiceNodeUtils->getSNList('dhcpserver');
                if (@sn > 0) { $hasHierarchy = 1; }

                # create a request for each service node
                foreach (keys %$sn_hash) {
                    my $reqcopy = {%$req};
                    $reqcopy->{'node'}                 = $sn_hash->{$_};
                    $reqcopy->{'_xcatdest'}            = $_;
                    $reqcopy->{_xcatpreprocessed}->[0] = 1;
                    push @requests, $reqcopy;
                }
            }
        }    # list of nodes specified
             # if new specified or there are nodes
    }    # end if service node only and NOT -n option
         # if -n option or nodes were specified
    elsif (@nodes > 0 or $opt{n}) {    #send the request to every dhservers
        $req->{'node'} = \@nodes;
        @requests = ({%$req}); #Start with a straight copy to reflect local instance
             # if not localonly - get list of service nodes and create requests
        unless ($localonly) {
            my @sn = xCAT::ServiceNodeUtils->getSNList('dhcpserver');
            if (@sn > 0) { $hasHierarchy = 1; }

            foreach my $s (@sn)
            {
                if (scalar @nodes == 1 and $nodes[0] eq $s) { next; }
                my $reqcopy = {%$req};
                $reqcopy->{'_xcatdest'} = $s;
                $reqcopy->{_xcatpreprocessed}->[0] = 1;
                push @requests, $reqcopy;
            }
        }
    }

    xCAT::MsgUtils->trace($verbose_on_off, "d", "dhcp: hasHierarchy=$hasHierarchy");

    if ($hasHierarchy)
    {
        #hierarchy detected, enforce more rigorous sanity
        my $ntab = xCAT::Table->new('networks');
        if ($ntab)
        {
            foreach (@{ $ntab->getAllEntries() })
            {
                # if dynamicrange specified but dhcpserver was not - issue error message
                if ($_->{dynamicrange} and not $_->{dhcpserver})
                {
                    $callback->({ error => [ "Hierarchy requested, therefore networks.dhcpserver must be set for net=" . $_->{net} . "" ], errorcode => [1] });
                    return [];
                }
            }
        }
    }

    #print Dumper(@requests);
    return \@requests;

}

#############################################################################
# process_request will perform syntax checking and do basic process checkingi
# and call other functions to complete the request to add or delete entries
#############################################################################
sub process_request
{
    my $req = shift;
    $callback = shift;
    my $oldmask = umask 0077;
    $restartdhcp = 0;
    my $rsp;

    #print Dumper($req);

    #>>>>>>>used for trace log>>>>>>>
    my $verbose_on_off = 0;

    Getopt::Long::Configure("bundling");
    $Getopt::Long::ignorecase = 0;
    Getopt::Long::Configure("no_pass_through");

    # Save the arguements in ARGV for GetOptions
    if   ($req && $req->{arg}) { @ARGV = @{ $req->{arg} }; }
    else                       { @ARGV = (); }

    my %opt;

    # Parse the options for makedhcp
    if (!GetOptions(
            'h|help'      => \$opt{h},
            'a'           => \$opt{a},
            'd'           => \$opt{d},
            'l|localonly' => \$localonly,
            'n'           => \$opt{n},
            'r'           => \$opt{r},
            's=s'         => \$statements,    # $statements is declared globally
            'q'           => \$opt{q},
            'V'           => \$opt{V}         #>>>>>>>used for trace log>>>>>>>
        ))
    {
        # If the arguements do not pass GetOptions then issue error message and return
        my $rsp = {};
        $rsp->{data}->[0] = $usage;
        xCAT::MsgUtils->message("E", $rsp, $callback, 1);
        return 1;
    }

    #>>>>>>>used for trace log>>>>>>>
    if ($opt{V}) { $verbose_on_off = 1; }

    # Check options again in case we are called from plugin and options have not been processed
    my $rc = 0;
    $rc = check_options($req, \%opt, $callback);

    if ($rc) {
        xCAT::MsgUtils->trace($verbose_on_off, "e", "dhcp: there is invalid option in command");
        return [];
    }


    # if option is query then call listnode for each node and return
    if ($opt{q})
    {
        # call listnode for each node requested
        foreach my $node (@{ $req->{node} }) {
            listnode($node, $callback);
        }
        return;
    }

    # if current node is a servicenode, make sure that it is also a dhcpserver
    my $isok = 1;
    if (xCAT::Utils->isServiceNode()) {
        $isok = 0;
        my @hostinfo = xCAT::NetworkUtils->determinehostname();
        my %iphash   = ();
        foreach (@hostinfo) { $iphash{$_} = 1; }
        my @sn = xCAT::ServiceNodeUtils->getSNList('dhcpserver');
        foreach my $s (@sn) {
            if (exists($iphash{$s})) {
                $isok = 1;
            }
        }
    }

    if ($isok == 0) {    #do nothing if it is a service node, but not dhcpserver
        xCAT::MsgUtils->trace($verbose_on_off, "d", "dhcp: it is a service node, but not dhcpserver. Do nothing");
        print "Do nothing\n";
        return;
    }

    my $servicenodetab = xCAT::Table->new('servicenode');
    my @nodeinfo       = xCAT::NetworkUtils->determinehostname;
    my $nodename       = pop @nodeinfo;                           # get hostname
    my $dhcpinterfaces = $servicenodetab->getNodeAttribs($nodename, ['dhcpinterfaces']);

    my %activenics;
    my $querynics = 1;

    if (xCAT::Utils->isServiceNode() and $dhcpinterfaces and $dhcpinterfaces->{dhcpinterfaces}) {
        my @dhcpifs = split ',', $dhcpinterfaces->{dhcpinterfaces};
        foreach my $nic (@dhcpifs) {
            $activenics{$nic} = 1;
            $querynics = 0;
        }
    }
    else
    {
        my @entries = xCAT::TableUtils->get_site_attribute("dhcpinterfaces");
        my $t_entry = $entries[0];
        unless (defined($t_entry))
        {    #LEGACY: singular keyname for old style site value
            @entries = xCAT::TableUtils->get_site_attribute("dhcpinterface");
            $t_entry = $entries[0];
        }
        if (defined($t_entry))

          #syntax should be like host|ifname1,ifname2;host2|ifname3,ifname2 etc or simply ifname,ifname2
          #depending on complexity of network wished to be described
        {
            my $dhcpinterfaces = $t_entry;
            my $dhcpif;
          INTF: foreach $dhcpif (split /;/, $dhcpinterfaces) {
                my $host;
                my $savehost;
                my $foundself = 1;
                if ($dhcpif =~ /\|/) {
                    $foundself = 0;

                    (my $ngroup, $dhcpif) = split /\|/, $dhcpif;
                    foreach $host (noderange($ngroup)) {
                        $savehost = $host;
                        unless (xCAT::NetworkUtils->thishostisnot($host)) {
                            $foundself = 1;
                            last;
                        }
                    }
                    if (!defined($savehost)) {    # host not defined in db,
                                                  # probably management node
                        unless (xCAT::NetworkUtils->thishostisnot($ngroup)) {
                            $foundself = 1;
                        }
                    }
                }
                unless ($foundself) {
                    next INTF;
                }
                foreach (split /[,\s]+/, $dhcpif)
                {
                    $activenics{$_} = 1;
                    $querynics = 0;
                }
            }
        }
        @entries = xCAT::TableUtils->get_site_attribute("nameservers");
        $t_entry = $entries[0];
        if (defined($t_entry)) {
            $sitenameservers = $t_entry;
        }
        @entries = xCAT::TableUtils->get_site_attribute("ntpservers");
        $t_entry = $entries[0];
        if (defined($t_entry)) {
            $sitentpservers = $t_entry;
        }
        @entries = xCAT::TableUtils->get_site_attribute("logservers");
        $t_entry = $entries[0];
        if (defined($t_entry)) {
            $sitelogservers = $t_entry;
        }
        @entries = xCAT::TableUtils->get_site_attribute("domain");
        $t_entry = $entries[0];

        unless (defined($t_entry))
        {
            # this may not be an error
            #    $callback->(
            #         {error => ["No domain defined in site tabe"], errorcode => [1]}
            #         );
            #    return;
        } else {
            $site_domain = $t_entry;
        }

        xCAT::MsgUtils->trace($verbose_on_off, "d", "dhcp: sitelogservers=$sitelogservers sitentpservers=$sitentpservers sitenameservers=$sitenameservers site_domain=$site_domain");
    }

    @dhcpconf  = ();
    @dhcp6conf = ();

    my $dhcplockfd;
    open($dhcplockfd, ">", "/tmp/xcat/dhcplock");
    flock($dhcplockfd, LOCK_EX);
    if ($::XCATSITEVALS{externaldhcpservers}) {

        # do nothing if remote dhcpservers at this point
        xCAT::MsgUtils->trace($verbose_on_off, "d", "dhcp: remote dhcpservers at this point, do nothing");
    } elsif ($opt{n}) {
        if (-e $dhcpconffile) {
            if ($^O eq 'aix') {

                # save NIM aix entries - to be restored later
                my $aixconf;
                open($aixconf, $dhcpconffile);
                if ($aixconf) {
                    my $save = 0;
                    while (<$aixconf>) {
                        if ($save) {
                            push @aixcfg, $_;
                        }

                        if ($_ =~ /#Network configuration end\n/) {
                            $save++;
                        }
                    }
                    close($aixconf);
                }
                $restartdhcp = 1;
                @dhcpconf    = ();
            }

            my $rsp;
            push @{ $rsp->{data} }, "Renamed existing dhcp configuration file to  $dhcpconffile.xcatbak\n";
            xCAT::MsgUtils->message("I", $rsp, $callback);

            my $bakname = "$dhcpconffile.xcatbak";
            rename("$dhcpconffile", $bakname);
            xCAT::MsgUtils->trace($verbose_on_off, "d", "dhcp: Renamed existing dhcp configuration file to  $dhcpconffile.xcatbak");
        }
    }
    else
    {
        xCAT::MsgUtils->trace($verbose_on_off, "d", "dhcp: load dhcp config file $dhcpconffile");
        my $rconf;
        open($rconf, $dhcpconffile);    # Read file into memory
        if ($rconf)
        {
            while (<$rconf>)
            {
                push @dhcpconf, $_;
            }
            close($rconf);
        }
        unless ($dhcpconf[0] =~ /^#xCAT/)
        {    #Discard file if not xCAT originated, like 1.x did
            $restartdhcp = 1;
            @dhcpconf    = ();
        }
        if ($dhcp6conffile and -e $dhcp6conffile) {
            open($rconf, $dhcp6conffile);
            while (<$rconf>) { push @dhcp6conf, $_; }
            close($rconf);
        }
        unless ($dhcp6conf[0] =~ /^#xCAT/)
        {    #Discard file if not xCAT originated
            $restartdhcp6 = 1;
            @dhcp6conf    = ();
        }
    }
    my $nettab = xCAT::Table->new("networks");
    my @vnets = $nettab->getAllAttribs('net', 'mgtifname', 'mask', 'dynamicrange', 'nameservers', 'ddnsdomain', 'domain');

    # get a list of all domains listed in xCAT network defs
    #       - include the site domain - if any
    my $nettab = xCAT::Table->new("networks");
    my @doms   = $nettab->getAllAttribs('domain');
    foreach my $netdom (@doms) {
        if ($netdom->{domain}) {
            push(@alldomains, $netdom->{domain}) unless grep(/^$netdom->{domain}$/, @alldomains);
        }
    }
    $nettab->close;

    # add the site domain
    if ($site_domain) {
        if (!grep(/^$site_domain$/, @alldomains)) {
            push(@alldomains, $site_domain);
        }
    }

    foreach (@vnets) {
        if ($_->{net} =~ /:/) {    #IPv6 detected
            $usingipv6 = 1;
        }
        addrangedetection($_); #add to hash for remembering whether a node has a static address or just happens to live dynamically
    }
    if ($^O eq 'aix')
    {
        @nrn = xCAT::NetworkUtils::get_subnet_aix();
    }
    else
    {
        my @nsrnoutput = split /\n/, `/bin/netstat -rn`;
        splice @nsrnoutput, 0, 2;
        foreach (@nsrnoutput) {    #scan netstat
            my @parts = split /\s+/;
            push @nrn, $parts[0] . ":" . $parts[7] . ":" . $parts[2] . ":" . $parts[3];
        }
        my @ip6routes = `ip -6 route`;
        foreach (@ip6routes) {

            #TODO: filter out multicast?  Don't know if multicast groups *can* appear in ip -6 route...
            if (/^default/ or /^fe80::\/64/ or /^unreachable/ or /^[^ ]+ via/) { #ignore link-local, junk, and routed networks
                next;
            }
            my @parts = split /\s+/;
            push @nrn6, { net => $parts[0], iface => $parts[2] };
        }
    }

    foreach (@vnets) {

        #TODO: v6 relayed networks?
        my $n  = $_->{net};
        my $if = $_->{mgtifname};
        my $nm = $_->{mask};
        if ($if =~ /!remote!/ and $n !~ /:/) { #only take in networks with special interface, but only v4 for now
            push @nrn, "$n:$if:$nm";
        }
    }
    if ($querynics)
    {
        # Use netstat to determine activenics only when no site ent.
        # TODO: IPv6 auto-detect, or just really really insist people define dhcpinterfaces or suffer doom?
        foreach (@nrn)
        {
            my @ent        = split /:/;
            my $firstoctet = $ent[0];
            $firstoctet =~ s/^(\d+)\..*/$1/;
            if ($ent[0] eq "169.254.0.0" or ($firstoctet >= 224 and $firstoctet <= 239) or $ent[0] eq "127.0.0.0" or $ent[0] eq '127')
            {
                next;
            }
            my $netif = $ent[1];
            if ($netif =~ /!remote!\S+/) {
                $netif =~ s/!remote!\s*(.*)$/$1/;
            }

            # Bridge nics
            if ((-f "/usr/sbin/brctl") || (-f "/sbin/brctl"))
            {
                #system "brctl showmacs $ent[1] 2>&1 1>/dev/null";
                system "brctl showmacs $netif 2>&1 1>/dev/null";
                if ($? == 0)
                {
                    #$activenics{$ent[1]} = 1;
                    $activenics{$netif} = 1;
                    next;
                }
            }

            #if ($ent[1] =~ m/(remote|ipoib|ib|vlan|bond|eth|myri|man|wlan|en\S*\d+|em\S*\d+)/)
            if ($netif =~ m/(remote|ipoib|ib|vlan|bond|eth|myri|man|wlan|en\S*\d+|em\S*\d+)/)
            {    #Mask out many types of interfaces, like xCAT 1.x
                    #$activenics{$ent[1]} = 1;
                $activenics{$netif} = 1;
            }
        }
    }

    if ($^O ne 'aix')
    {
        my $os = xCAT::Utils->osver();

        #add the active nics to /etc/sysconfig/dhcpd or /etc/default/dhcp3-server(ubuntu)
        my $dhcpver;
        my %missingfiles = ("dhcpd" => 1, "dhcpd6" => 1, "dhcp3-server" => 1);
        foreach $dhcpver ("dhcpd", "dhcpd6", "dhcp3-server", "isc-dhcp-server") {

            # if ipv6 is not present, no need to look at dhcpd6 files
            if (!$usingipv6 and $dhcpver eq "dhcpd6") {
                delete($missingfiles{"dhcpd6"});
                next;
            }

            # check the possible system config paths for the various Linux O/S
            my $syspath;
            foreach $syspath ("/etc/sysconfig", "/etc/default") {

                my $generatedpath = "$syspath/$dhcpver";
                my $dhcpd_key     = "DHCPDARGS";

                # For SLES11+ and RHEL7+ Operating system releases, the
                # dhcpd/dhcpd6 configuration is stored in the same file
                my $os_ver = $os;
                $os_ver =~ s/[^0-9.^0-9]//g;
                if (($os =~ /sles/i && $os_ver >= 11) ||
                    ($os =~ /rhels/i && $os_ver >= 7)) {

                    $dhcpd_key = "DHCPD_INTERFACE";
                    if ($usingipv6 and $dhcpver eq "dhcpd6") {
                        $dhcpd_key     = "DHCPD6_INTERFACE";
                        $generatedpath = "$syspath/dhcpd";
                    }
                }

                if ($generatedpath and -e "$generatedpath") {

                    # remove the file from the hash because it will be processed
                    if ($dhcpver eq "dhcpd") {

                        # If dhcpd is found, then not necessary to find dhcp3-server
                        delete($missingfiles{"dhcp3-server"});
                    }

                    # UBUNTU/DEBIAN specific
                    if ($dhcpver eq "isc-dhcp-server") {

                        # UBUNTU/DEBIAN configuration ipv6 & ipv4 uses the isc-dhcp-server
                        # remove all other from the missingfiles hash
                        delete($missingfiles{"dhcpd"});
                        delete($missingfiles{"dhcpd6"});
                        delete($missingfiles{"dhcp3-server"});

                        $dhcpd_key = "INTERFACES";
                    }
                    delete($missingfiles{$dhcpver});

                    open DHCPD_FD, "$generatedpath";
                    my $syscfg_dhcpd = "";
                    my $found        = 0;

                    my $ifarg = "$dhcpd_key=\"";
                    foreach (keys %activenics) {
                        if (/!remote!/) { next; }
                        $ifarg .= " $_";
                    }
                    $ifarg =~ s/\=\" /\=\"/;
                    $ifarg .= "\"\n";

                    while (<DHCPD_FD>) {
                        if ($_ =~ m/^$dhcpd_key/) {
                            $found = 1;
                            $syscfg_dhcpd .= $ifarg;
                        } else {
                            $syscfg_dhcpd .= $_;
                        }
                    }

                    if ($found eq 0) {
                        $syscfg_dhcpd .= $ifarg;
                    }
                    close DHCPD_FD;

                    # write out the new file with the interfaces defined
                    open DBG_FD, '>', "$generatedpath";
                    print DBG_FD $syscfg_dhcpd;
                    close DBG_FD;
                }
            }
        }

        if ($usingipv6) {

            # sles11.3 and rhels7 has dhcpd and dhcpd6 config in the dhcp file
            if ($os =~ /sles/i || $os =~ /rhels7/i) {
                if ($missingfiles{dhcpd}) {
                    $callback->({ error => ["The file /etc/sysconfig/dhcpd doesn't exist, check the dhcp server"] });
                }
            } else {
                if ($missingfiles{dhcpd6}) {
                    $callback->({ error => ["The file /etc/sysconfig/dhcpd6 doesn't exist, check the dhcp server"] });
                }
            }
        }
        if ($missingfiles{dhcpd}) {
            $callback->({ error => ["The file /etc/sysconfig/dhcpd doesn't exist, check the dhcp server"] });
        }
    }

    unless ($dhcpconf[0])
    {    #populate an empty config with some starter data...
        $restartdhcp = 1;
        newconfig();
    }
    if ($usingipv6 and not $dhcp6conf[0]) {
        $restartdhcp6 = 1;
        newconfig6();
    }
    if ($^O ne 'aix')
    {
        foreach (keys %activenics)
        {
            addnic($_, \@dhcpconf);
            if ($usingipv6) {
                addnic($_, \@dhcp6conf);
            }
        }
    }

    #need to transfer CEC/Frame to FSPs/BPAs
    my @inodes     = ();
    my @validnodes = ();
    my $pnode;
    my $cnode;
    if ($req->{node})
    {
        #@inodes = split /,/,${$req->{noderange}};
        my $typehash = xCAT::DBobjUtils->getnodetype(\@{ $req->{node} });
        foreach $pnode (@{ $req->{node} })
        {
            my $ntype = $$typehash{$pnode};
            if ($ntype =~ /^(cec|frame)$/)
            {
                $cnode = xCAT::DBobjUtils->getchildren($pnode);
                foreach (@$cnode)
                {
                    push @validnodes, $_;
                }
            } else
            {
                push @validnodes, $pnode;
            }
        }
        $req->{node} = \@validnodes;
    }

    if ((!$req->{node}) && ($opt{a}))
    {
        if ($opt{d})    #delete all entries
        {
            $req->{node} = [];
            my $nodelist = xCAT::Table->new('nodelist');
            my @entries  = ($nodelist->getAllNodeAttribs([qw(node)]));
            my @nodeentries;
            foreach (@entries) {
                push @nodeentries, $_->{node};
            }
            my $typehash = xCAT::DBobjUtils->getnodetype(\@nodeentries);
            foreach (@entries)
            {
                #delete the CEC and Frame node
                my $ntype = $$typehash{ $_->{node} };
                unless ($ntype =~ /^(cec|frame)$/)
                {
                    push @{ $req->{node} }, $_->{node};
                }
            }
        }
        else    #add all entries
        {
            $req->{node} = [];
            my $mactab = xCAT::Table->new('mac');

            my @entries = ();
            if ($mactab) {
                @entries = ($mactab->getAllNodeAttribs([qw(mac)]));
            }

            foreach (@entries)
            {
                push @{ $req->{node} }, $_->{node};
            }

            # don't put compute node entries in for AIX nodes
            # this is handled by NIM - duplicate entires will cause
            # an error
            if ($^O eq 'aix') {
                my @tmplist;
                foreach my $n (@{ $req->{node} })
                {
                    # get the nodetype for each node
                    my $ntable = xCAT::Table->new('nodetype');
                    if ($ntable) {
                        my $ntype = $ntable->getNodeAttribs($n, ['nodetype']);

                        # don't add if it is type "osi"
                        unless ($ntype->{nodetype} =~ /osi/) {
                            push @tmplist, $n;
                        }
                    }
                }
                @{ $req->{node} } = @tmplist;
            }
        }
    }

    foreach (@nrn)
    {
        my @line       = split /:/;
        my $firstoctet = $line[0];
        $firstoctet =~ s/^(\d+)\..*/$1/;
        if ($line[0] eq "169.254.0.0" or ($firstoctet >= 224 and $firstoctet <= 239))
        {
            next;
        }
        my $netif = $line[1];
        if ($netif =~ /!remote!\S+/) {
            $netif =~ s/!remote!\s*(.*)$/$1/;
            if (!defined($activenics{"!remote!"})) {
                next;
            } elsif (!defined($activenics{$netif})) {
                addnic($netif, \@dhcpconf);
                $activenics{$netif} = 1;
            }
        }

        #if ($activenics{$line[1]} and $line[3] !~ /G/)
        if ($activenics{$netif} and $line[3] !~ /G/)
        {
            addnet($line[0], $line[2]);
        }
    }
    foreach (@nrn6) {    #do the ipv6 networks
        addnet6($_);     #already did all the filtering before putting into nrn6
    }

    if ($req->{node})
    {
        my $ip_hash;
        foreach my $node (@{ $req->{node} }) {

            #need to change the way of finding IP for nodes
            my $ifip = xCAT::NetworkUtils->isIpaddr($node);
            if ($ifip)
            {
                $ip_hash->{$node} = $node;
            }
            else
            {
                my $hoststab = xCAT::Table->new('hosts');
                my $ent = $hoststab->getNodeAttribs($node, ['ip']);
                if ($ent->{ip}) {
                    if ($ip_hash->{ $ent->{ip} }) {
                        $callback->({ error => [ "Duplicated IP addresses in hosts table for following nodes: $node," . $ip_hash->{ $ent->{ip} } ], errorcode => [1] });
                        return;
                    }
                    $ip_hash->{ $ent->{ip} } = $node;
                }
            }
        }

        if ($^O ne 'aix')
        {
            my $passtab = xCAT::Table->new('passwd');
            my $ent;
            ($ent) = $passtab->getAttribs({ key => "omapi" }, qw(username password));
            unless ($ent->{username} and $ent->{password})
            {
                $callback->({ error => ["Unable to access omapi key from passwd table, add the key from dhcpd.conf or makedhcp -n to create a new one"], errorcode => [1] });
                syslog("local4|err", "Unable to access omapi key from passwd table, unable to update DHCP configuration");
                return;
            }    # TODO sane err

            #Have nodes to update
            #open2($omshellout,$omshell,"/usr/bin/omshell");
            open($omshell, "|/usr/bin/omshell > /dev/null");
            print $omshell "key "
              . $ent->{username} . " \""
              . $ent->{password} . "\"\n";
            if ($::XCATSITEVALS{externaldhcpservers}) {
                print $omshell "server $::XCATSITEVALS{externaldhcpservers}\n";
            }
            print $omshell "connect\n";
            if ($usingipv6) {
                open($omshell6, "|/usr/bin/omshell > /dev/null");
                if ($::XCATSITEVALS{externaldhcpservers}) {
                    print $omshell "server $::XCATSITEVALS{externaldhcpservers}\n";
                }
                print $omshell6 "port 7912\n";
                print $omshell6 "key "
                  . $ent->{username} . " \""
                  . $ent->{password} . "\"\n";
                print $omshell6 "connect\n";
            }
        }

        my $nrtab    = xCAT::Table->new('noderes');
        my $chaintab = xCAT::Table->new('chain');
        if ($chaintab) {
            $chainents = $chaintab->getNodesAttribs($req->{node}, ['currstate']);
        } else {
            $chainents = undef;
        }
        $nrhash = $nrtab->getNodesAttribs($req->{node}, [ 'tftpserver', 'netboot', 'proxydhcp' ]);
        my $nodetypetab;
        $nodetypetab = xCAT::Table->new('nodetype', -create => 0);
        if ($nodetypetab) {
            $nodetypeents = $nodetypetab->getNodesAttribs($req->{node}, [qw(os)]);
        }
        my $iscsitab = xCAT::Table->new('iscsi', -create => 0);
        if ($iscsitab) {
            $iscsients = $iscsitab->getNodesAttribs($req->{node}, [qw(server target lun iname)]);
        }
        my $mactab = xCAT::Table->new('mac');
        $machash = $mactab->getNodesAttribs($req->{node}, ['mac']);
        my $vpdtab = xCAT::Table->new('vpd');
        $vpdhash = $vpdtab->getNodesAttribs($req->{node}, ['uuid']);
        foreach (@{ $req->{node} })
        {
            if ($opt{d})
            {
                if ($^O eq 'aix')
                {
                    delnode_aix $_;
                }
                else
                {
                    delnode $_;
                }
            }
            else
            {
                if (xCAT::NetworkUtils->getipaddr($_) and not xCAT::NetworkUtils->nodeonmynet($_))
                {
                    next;
                }
                addnode $_;
                if ($usingipv6) {
                    addnode6 $_;
                }
            }
        }
        close($omshell) if ($^O ne 'aix');
        close($omshell6) if ($omshell6 and $^O ne 'aix');
        foreach my $node (@{ $req->{node} })
        {
            unless ($machash)
            {
                $callback->(
                    {
                        error => ["Unable to open mac table, it may not exist yet"],
                        errorcode => [1]
                    }
                );
                return;
            }
            my $ent = $machash->{$node}->[0]; #tab->getNodeAttribs($node, [qw(mac)]);
            unless ($ent and $ent->{mac})
            {
                $callback->(
                    {
                        warning => ["Unable to find mac address for $node"]
                    }
                );
                next;
            }
        }
    }
    writeout();
    if (not $::XCATSITEVALS{externaldhcpservers} and $restartdhcp) {
        xCAT::MsgUtils->trace($verbose_on_off, "d", "dhcp: restart dhcp service");
        if ($^O eq 'aix')
        {
            restart_dhcpd_aix();
        }
        else {
            if ($distro =~ /ubuntu.*/ || $distro =~ /debian.*/i)
            {
                if (-e '/etc/dhcp/dhcpd.conf') {
                    system("chmod a+r /etc/dhcp/dhcpd.conf");

                    #system("/etc/init.d/isc-dhcp-server restart");
                }
                else {
                    #ubuntu config
                    system("chmod a+r /etc/dhcp3/dhcpd.conf");

                    #system("/etc/init.d/dhcp3-server restart");
                }
            }

            #else
            #{
            #    system("/etc/init.d/dhcpd restart");
            #    # should not chkconfig dhcpd on every makedhcp invoation
            #    # it is not appropriate and will cause problem for HAMN
            #    # do it in xcatconfig instead
            #    #system("chkconfig dhcpd on");
            #}
            xCAT::Utils->restartservice("dhcp");
            print "xx";
        }
    }
    flock($dhcplockfd, LOCK_UN);
    umask $oldmask;
}

# Restart dhcpd on aix
sub restart_dhcpd_aix
{
    #Check if dhcpd is running
    my @res = xCAT::Utils->runcmd('lssrc -s dhcpsd', 0);
    if ($::RUNCMD_RC != 0)
    {
        xCAT::MsgUtils->message("E", "Failed to check dhcpsd status\n");
    }
    if (grep /\sactive/, @res)
    {
        xCAT::Utils->runcmd('refresh -s dhcpsd', 0);
        xCAT::MsgUtils->message("E", "Failed to refresh dhcpsd configuration\n") if ($::RUNCMD_RC);
    }
    else
    {
        xCAT::Utils->runcmd('startsrc -s dhcpsd', 0);
        xCAT::MsgUtils->message("E", "Failed to start dhcpsd\n") if ($::RUNCMD_RC);
    }
    return 1;
}

sub getzonesfornet {
    my $net   = shift;
    my $mask  = shift;
    my @zones = ();
    if ($net =~ /:/) { #ipv6, for now do the simple stuff under the assumption we won't have a mask indivisible by 4
        $net =~ s/\/(.*)//;
        my $maskbits = $1;
        if ($mask) {
            die "Not supporting having a mask like $mask on an ipv6 network like $net";
        }
        my $netnum = getipaddr($net, GetNumber => 1);
        unless ($netnum) { return (); }
        $netnum->brsft(128 - $maskbits);
        my $prefix = $netnum->as_hex();
        my $nibbs  = $maskbits / 4;
        $prefix =~ s/^0x//;
        my $rev;

        foreach (reverse(split //, $prefix)) {
            $rev .= $_ . ".";
            $nibbs--;
        }
        while ($nibbs) {
            $rev .= "0.";
            $nibbs--;
        }
        $rev .= "ip6.arpa.";
        return ($rev);
    }

    #return all in-addr reverse zones for a given mask and net
    #for class a,b,c, the answer is easy
    #for classless, identify the partial byte, do $netbyte | (0xff&~$maskbyte) to get the highest value
    #return sequence from $net to value calculated above
    #since old bind.pm only went as far as class c, we will carry that over for now (more people with smaller than class c complained
    #and none hit the theoretical conflict.  FYI, the 'official' method in RFC 2317 seems cumbersome, but maybe one day it makes sense
    #since this is dhcpv4 for now, we'll use the inet_aton, ntop functions to generate the answers (dhcpv6 omapi would be nice...)
    my $netn  = inet_aton($net);
    my $maskn = inet_aton($mask);
    unless ($netn and $mask) { return (); }
    my $netnum  = unpack('N', $netn);
    my $masknum = unpack('N', $maskn);
    if ($masknum >= 0xffffff00) { #treat all netmasks higher than 255.255.255.0 as class C
        $netnum = $netnum & 0xffffff00;
        $netn   = pack('N', $netnum);
        $net    = inet_ntoa($netn);
        $net =~ s/\.[^\.]*$//;
        return (join('.', reverse(split('\.', $net))) . '.IN-ADDR.ARPA.');
    } elsif ($masknum > 0xffff0000) {    #class b (/16) to /23
        my $tempnumber = ($netnum >> 8);
        $masknum = $masknum >> 8;
        my $highnet = $tempnumber | (0xffffff & ~$masknum);
        foreach ($tempnumber .. $highnet) {
            $netnum = $_ << 8;
            $net = inet_ntoa(pack('N', $netnum));
            $net =~ s/\.[^\.]*$//;
            push @zones, join('.', reverse(split('\.', $net))) . '.IN-ADDR.ARPA.';
        }
        return @zones;
    } elsif ($masknum > 0xff000000) { #class a (/8) to /15, could have made it more flexible, for for only two cases, not worth in
        my $tempnumber = ($netnum >> 16); #the last two bytes are insignificant, shift them off to make math easier
        $masknum = $masknum >> 16;
        my $highnet = $tempnumber | (0xffff & ~$masknum);
        foreach ($tempnumber .. $highnet) {
            $netnum = $_ << 16;    #convert back to the real network value
            $net = inet_ntoa(pack('N', $netnum));
            $net =~ s/\.[^\.]*$//;
            $net =~ s/\.[^\.]*$//;
            push @zones, join('.', reverse(split('\.', $net))) . '.IN-ADDR.ARPA.';
        }
        return @zones;
    } else {    #class a (theoretically larger, but those shouldn't exist)
        my $tempnumber = ($netnum >> 24); #the last two bytes are insignificant, shift them off to make math easier
        $masknum = $masknum >> 24;
        my $highnet = $tempnumber | (0xff & ~$masknum);
        foreach ($tempnumber .. $highnet) {
            $netnum = $_ << 24;    #convert back to the real network value
            $net = inet_ntoa(pack('N', $netnum));
            $net =~ s/\.[^\.]*$//;
            $net =~ s/\.[^\.]*$//;
            $net =~ s/\.[^\.]*$//;
            push @zones, join('.', reverse(split('\.', $net))) . '.IN-ADDR.ARPA.';
        }
        return @zones;
    }
}

sub putmyselffirst {
    my $srvlist = shift;
    if ($srvlist =~ /,/) { #TODO: only reshuffle when requested, or allow opt out of reshuffle?
        my @dnsrvs = split /,/, $srvlist;
        my @reordered;
        foreach (@dnsrvs) {
            if (xCAT::NetworkUtils->thishostisnot($_)) {
                push @reordered, $_;
            } else {
                unshift @reordered, $_;
            }
        }
        $srvlist = join(', ', @reordered);
    }
    return $srvlist;
}

sub addnet6
{
    if ($::XCATSITEVALS{externaldhcpservers}) { return; }
    if (!$usingipv6) { return; }
    my $netentry = shift;
    my $net      = $netentry->{net};
    my $iface    = $netentry->{iface};
    my $idx      = 0;
    if (grep /\} # $net subnet_end/, @dhcp6conf) {    #need to add to dhcp6conf
        return;
    } else {                                          #need to add to dhcp6conf
        $restartdhcp6 = 1;
        while ($idx <= $#dhcp6conf)
        {
            if ($dhcp6conf[$idx] =~ /\} # $iface nic_end/) {
                last;
            }
            $idx++;
        }
        unless ($dhcp6conf[$idx] =~ /\} # $iface nic_end\n/) {
            $callback->(
                {
                    error =>
                      ["Could not add the subnet $net for interface $iface into $dhcpconffile.\nPlease verify the xCAT database matches networks defined on this system."],
                    errorcode => [1]
                }
            );
            return 1;
        }

    }

    my $dhcplease = 43200;
    if (defined $::XCATSITEVALS{'dhcplease'} && $::XCATSITEVALS{'dhcplease'} ne "") {
        $dhcplease = $::XCATSITEVALS{'dhcplease'};
    }

    my @netent = (
        "  subnet6 $net {\n",
        "    authoritative;\n",
        "    max-lease-time $dhcplease;\n",
        "    min-lease-time $dhcplease;\n",
        "    default-lease-time $dhcplease;\n",
    );

    #for now, just do address allocatios (phase 1)
    #phase 2 (by 2.6 presumably) will include the various things like DNS server and other options allowed by dhcpv6
    #gateway is *not* currently allowed to be DHCP designated, router advertises its own self indpendent of dhcp.  We'll just keep it that way
    #domain search list is allowed (rfc 3646)
    #nis domain is also an alloed option (rfc 3898)
    #sntp server list (rfc 4075)
    #ntp server rfc 5908
    #fqdn rfc 4704
    #posix timezone rfc 4833/tzdb timezone
    #phase 3 will include whatever is required to do Netboot6.  That might be in the october timeframe for lack of implementations to test
    #boot url/param (rfc 59070)
    my $netdomain = $netcfgs{$net}->{domain};
    unless ($netdomain) { $netdomain = $site_domain; }
    push @netent, "    option domain-name \"" . $netdomain . "\";\n";

    #  add domain-search if not sles10 or rh5
    my $osv = xCAT::Utils->osver();
    unless (($osv =~ /^sle[sc]10/) || ($osv =~ /^rh.*5$/)) {

        # We want something like "option domain-search "foo.com", "bar.com";"
        my $domainstring = qq~"$netcfgs{$net}->{domain}"~;
        foreach my $dom (@alldomains) {
            chomp $dom;
            if ($dom ne $netcfgs{$net}->{domain}) {
                $domainstring .= qq~, "$dom"~;
            }
        }

        if ($netcfgs{$net}->{domain}) {
            push @netent, "    option domain-search  $domainstring;\n";
        }
    }

    my $nameservers = $netcfgs{$net}->{nameservers};
    if ($nameservers and $nameservers =~ /:/) {
        push @netent, "    nameservers " . $netcfgs{$net}->{nameservers} . ";\n";
    }
    my $ddnserver = $nameservers;
    $ddnserver =~ s/,.*//;
    my $ddnsdomain;
    if ($netcfgs{$net}->{ddnsdomain}) {
        $ddnsdomain = $netcfgs{$net}->{ddnsdomain};
    }
    if ($::XCATSITEVALS{dnshandler} =~ /ddns/) {
        if ($ddnsdomain) {
            push @netent, "    ddns-domainname \"" . $ddnsdomain . "\";\n";
            push @netent, "    zone $ddnsdomain. {\n";
        } else {
            push @netent, "    zone $netdomain. {\n";
        }
        push @netent, "       primary $ddnserver; key xcat_key; \n";
        push @netent, "    }\n";
        foreach (getzonesfornet($net)) {
            push @netent, "    zone $_ {\n";
            push @netent, "       primary $ddnserver; key xcat_key; \n";
            push @netent, "    }\n";
        }
    }
    if ($netcfgs{$net}->{range}) {
        push @netent, "    range6 " . $netcfgs{$net}->{range} . ";\n";
    } else {
        $callback->({ warning => ["No dynamic range specified for $net. Hosts with no static address will receive no addresses on this subnet."] });
    }
    push @netent, "  } # $net subnet_end\n";
    splice(@dhcp6conf, $idx, 0, @netent);
}

sub addnet
{
    if ($::XCATSITEVALS{externaldhcpservers}) { return; }
    my $net  = shift;
    my $mask = shift;
    my $nic;
    my $domain;
    my $firstoctet = $net;
    $firstoctet =~ s/^(\d+)\..*/$1/;
    if ($net eq "169.254.0.0" or ($firstoctet >= 224 and $firstoctet <= 239)) {
        return;
    }
    unless (grep /\} # $net\/$mask subnet_end/, @dhcpconf)
    {
        $restartdhcp = 1;
        foreach (@nrn)
        {    # search for relevant NIC
            my @ent = split /:/;
            $firstoctet = $ent[0];
            $firstoctet =~ s/^(\d+)\..*/$1/;
            if ($ent[0] eq "169.254.0.0" or ($firstoctet >= 224 and $firstoctet <= 239))
            {
                next;
            }
            if ($ent[0] eq $net and $ent[2] eq $mask)
            {
                $nic = $ent[1];
                if ($nic =~ /!remote!\S+/) {
                    $nic =~ s/!remote!\s*(.*)$/$1/;
                }

                # The first nic that matches the network,
                # what will happen if there are more than one nics in the same subnet,
                # and we want to use the second nic as the dhcp interfaces?
                # this is a TODO
                last;
            }
        }

        #print " add $net $mask under $nic\n";
        my $idx = 0;
        if ($^O ne 'aix')
        {
            while ($idx <= $#dhcpconf)
            {
                if ($dhcpconf[$idx] =~ /\} # $nic nic_end\n/)
                {
                    last;
                }
                $idx++;
            }
            unless ($dhcpconf[$idx] =~ /\} # $nic nic_end\n/)
            {
                $callback->(
                    {
                        error =>
                          ["Could not add the subnet $net for interface $nic into $dhcpconffile.\nPlease verify the xCAT database matches networks defined on this system."],
                        errorcode => [1]
                    }
                );
                return 1;
            }
        }

        # if here, means we found the idx before which to insert
        my $nettab = xCAT::Table->new("networks");
        my $nameservers;
        my $ntpservers;
        my $logservers;
        my $gateway;
        my $tftp;
        my $range;
        my $myip;
        my @myipd = xCAT::NetworkUtils->my_ip_facing($net);
        unless ($myipd[0]) { $myip = $myipd[1]; }

        if ($nettab)
        {
            my $mask_formated = $mask;
            if ($^O eq 'aix')
            {
                my $mask_shift = 32 - $mask;
                $mask_formated = inet_ntoa(pack("N", 2**$mask - 1 << $mask_shift));

                #  $mask_formated = inet_ntoa(pack("N", 2**$mask - 1 << (32 - $mask)));
            }

            my ($ent) =
              $nettab->getAttribs({ net => $net, mask => $mask_formated },
                qw(tftpserver nameservers ntpservers logservers gateway dynamicrange dhcpserver domain));
            if ($ent and $ent->{ntpservers}) {
                $ntpservers = $ent->{ntpservers};
            } elsif ($sitentpservers) {
                $ntpservers = $sitentpservers;
            }
            if ($ent and $ent->{logservers}) {
                $logservers = $ent->{logservers};
            } elsif ($sitelogservers) {
                $logservers = $sitelogservers;
            }
            if ($ent and $ent->{domain}) {
                $domain = $ent->{domain};
            } elsif ($site_domain) {
                $domain = $site_domain;
            } else {
                $callback->(
                    {
                        warning => [
"No $net specific entry for domain, and no domain defined in site table."
                          ]
                    });
            }

            if ($ent and $ent->{nameservers})
            {
                $nameservers = $ent->{nameservers};
            }
            else
            {
                if ($sitenameservers) {
                    $nameservers = $sitenameservers;
                } else {
                    $callback->(
                        {
                            warning => [
"No $net specific entry for nameservers, and no nameservers defined in site table."
                              ]
                        }
                    );
                }
            }

            # convert <xcatmaster> to nameserver IP
            $nameservers =~ s/<xcatmaster>/$myip/g;

            if (!$ntpservers || ($ntpservers eq '<xcatmaster>'))
            {
                $ntpservers = $myip;
            }

            $nameservers = putmyselffirst($nameservers);
            $ntpservers  = putmyselffirst($ntpservers);
            $logservers  = putmyselffirst($logservers);


            if ($ent and $ent->{tftpserver})
            {
                $tftp = $ent->{tftpserver};
            }
            else
            {    #presume myself to be it, dhcp no longer does this for us
                $tftp = $myip;
            }
            if ($ent and $ent->{gateway})
            {
                $gateway = $ent->{gateway};

                if ($gateway eq '<xcatmaster>')
                {
                    if (xCAT::NetworkUtils->ip_forwarding_enabled())
                    {
                        $gateway = $myip;
                    }
                    else
                    {
                        $gateway = '';
                    }
                }
            }
            if ($ent and $ent->{dynamicrange})
            {
                unless ($ent->{dhcpserver}
                    and xCAT::NetworkUtils->thishostisnot($ent->{dhcpserver}))
                {    #If specific, only one dhcp server gets a dynamic range
                    $range = $ent->{dynamicrange};
                    $range =~ s/[,-]/ /g;
                }
            }
            else
            {
                $callback->(
                    {
                        warning => [
"No dynamic range specified for $net. If hardware discovery is being used, a dynamic range is required."
                          ]
                    }
                );
            }
        }
        else
        {
            $callback->(
                {
                    error =>
                      ["Unable to open networks table, please run makenetworks"],
                    errorcode => [1]
                }
            );
            return 1;
        }

        if ($^O eq 'aix')
        {
            return gen_aix_net($myip, $net, $mask, $gateway, $tftp,
                $logservers, $ntpservers, $domain,
                $nameservers, $range);
        }
        my @netent;

        my $maskn = unpack("N", inet_aton($mask));
        my $netn  = unpack("N", inet_aton($net));
        my $dhcplease = 43200;
        if (defined $::XCATSITEVALS{'dhcplease'} && $::XCATSITEVALS{'dhcplease'} ne "") {
            $dhcplease = $::XCATSITEVALS{'dhcplease'};
        }
        @netent = (
            "  subnet $net netmask $mask {\n",
            "    authoritative;\n",
            "    max-lease-time $dhcplease;\n",
            "    min-lease-time $dhcplease;\n",
            "    default-lease-time $dhcplease;\n"
        );
        if ($gateway)
        {
            my $gaten = unpack("N", inet_aton($gateway));
            if (($gaten & $maskn) == ($maskn & $netn))
            {
                push @netent, "    option routers  $gateway;\n";
            }
            else
            {
                $callback->(
                    {
                        error => [
"Specified gateway $gateway is not valid for $net/$mask, must be on same network"
                        ],
                        errorcode => [1]
                    }
                );
            }
        }
        if ($tftp)
        {
            push @netent, "    next-server  $tftp;\n";
        }
        if ($logservers) {
            push @netent, "    option log-servers $logservers;\n";
        } elsif ($myip) {
            push @netent, "    option log-servers $myip;\n";
        }
        if ($ntpservers) {
            push @netent, "    option ntp-servers $ntpservers;\n";
        }
        if ($nameservers)
        {
            push @netent, "    option domain-name \"$domain\";\n";
            push @netent, "    option domain-name-servers  $nameservers;\n";
        }

        #  add domain-search if not sles10 or rh5
        my $osv = xCAT::Utils->osver();
        unless (($osv =~ /^sle[sc]10/) || ($osv =~ /^rh.*5$/)) {

            # want something like "option domain-search "foo.com", "bar.com";"
            my $domainstring = qq~"$domain"~;
            foreach my $dom (@alldomains) {
                chomp $dom;
                if ($dom ne $domain) {
                    $domainstring .= qq~, "$dom"~;
                }
            }

            if ($domain) {
                push @netent, "    option domain-search  $domainstring;\n";
            }
        }

        my $ddnserver = $nameservers;
        $ddnserver =~ s/,.*//;
        my $ddnsdomain;
        if ($netcfgs{$net}->{ddnsdomain}) {
            $ddnsdomain = $netcfgs{$net}->{ddnsdomain};
        }
        if ($::XCATSITEVALS{dnshandler} =~ /ddns/) {
            if ($ddnsdomain) {
                push @netent, "    ddns-domainname \"" . $ddnsdomain . "\";\n";
                push @netent, "    zone $ddnsdomain. {\n";
            } else {
                push @netent, "    zone $domain. {\n";
            }
            if ($ddnserver)
            {
                push @netent, "   primary $ddnserver; key xcat_key; \n";
            }
            push @netent, " }\n";
            foreach (getzonesfornet($net, $mask)) {
                push @netent, "zone $_ {\n";
                if ($ddnserver)
                {
                    push @netent, "   primary $ddnserver; key xcat_key; \n";
                }
                push @netent, " }\n";
            }
        }

        my $tmpmaskn = unpack("N", inet_aton($mask));
        my $maskbits = 32;
        while (not($tmpmaskn & 1)) {
            $maskbits--;
            $tmpmaskn = $tmpmaskn >> 1;
        }

        # $lstatements = 'if exists gpxe.bus-id { filename = \"\"; } else if exists client-architecture { filename = \"xcat/xnba.kpxe\"; } '.$lstatements;
        push @netent, "    if option user-class-identifier = \"xNBA\" and option client-architecture = 00:00 { #x86, xCAT Network Boot Agent\n";
        push @netent, "       always-broadcast on;\n";
        push @netent, "       filename = \"http://$tftp/tftpboot/xcat/xnba/nets/" . $net . "_" . $maskbits . "\";\n";
        push @netent, "    } else if option user-class-identifier = \"xNBA\" and option client-architecture = 00:09 { #x86, xCAT Network Boot Agent\n";
        push @netent, "       filename = \"http://$tftp/tftpboot/xcat/xnba/nets/" . $net . "_" . $maskbits . ".uefi\";\n";
        push @netent, "    } else if option client-architecture = 00:00  { #x86\n";
        push @netent, "      filename \"xcat/xnba.kpxe\";\n";
        push @netent, "    } else if option vendor-class-identifier = \"Etherboot-5.4\"  { #x86\n";
        push @netent, "      filename \"xcat/xnba.kpxe\";\n";
        push @netent,
          "    } else if option client-architecture = 00:07 { #x86_64 uefi\n ";
        push @netent, "      filename \"xcat/xnba.efi\";\n";
        push @netent,
"    } else if option client-architecture = 00:09 { #x86_64 uefi alternative id\n ";
        push @netent, "      filename \"xcat/xnba.efi\";\n";
        push @netent,
          "    } else if option client-architecture = 00:02 { #ia64\n ";
        push @netent, "      filename \"elilo.efi\";\n";
        push @netent,
          "    } else if option client-architecture = 00:0e { #OPAL-v3\n ";
        push @netent, "      option conf-file = \"http://$tftp/tftpboot/pxelinux.cfg/p/" . $net . "_" . $maskbits . "\";\n";
        push @netent,
"    } else if substring(filename,0,1) = null { #otherwise, provide yaboot if the client isn't specific\n ";
        push @netent, "      filename \"/yaboot\";\n";
        push @netent, "    }\n";

        if ($range) {
            foreach my $singlerange (split /;/, $range) {
                push @netent, "    range dynamic-bootp $singlerange;\n"
            }
        }
        push @netent, "  } # $net\/$mask subnet_end\n";
        splice(@dhcpconf, $idx, 0, @netent);
    }
}

######################################################
# Generate network configuration for aix
######################################################
sub gen_aix_net
{
    my $myip        = shift;
    my $net         = shift;
    my $mask        = shift;
    my $gateway     = shift;
    my $tftp        = shift;
    my $logservers  = shift;
    my $ntpservers  = shift;
    my $domain      = shift;
    my $nameservers = shift;
    my $range       = shift;

    my $idx = 0;
    while ($idx <= $#dhcpconf)
    {
        if ($dhcpconf[$idx] =~ /#Network configuration end\n/)
        {
            last;
        }
        $idx++;
    }

    unless ($dhcpconf[$idx] =~ /#Network configuration end\n/)
    {
        return 1;    #TODO: this is an error condition
    }

    $range =~ s/ /-/;
    my @netent = ("network $net $mask\n{\n");
    if ($gateway)
    {
        if ($gateway eq '<xcatmaster>')
        {
            if (xCAT::NetworkUtils->ip_forwarding_enabled())
            {
                $gateway = $myip;
            }
            else
            {
                $gateway = '';
            }
        }
        if (xCAT::NetworkUtils::isInSameSubnet($gateway, $net, $mask, 1))
        {
            push @netent, "    option 3 $gateway\n";
        }
        else
        {
            $callback->(
                {
                    error => [
"Specified gateway $gateway is not valid for $net/$mask, must be on same network"
                    ],
                    errorcode => [1]
                }
            );
        }
    }

    #    if ($tftp)
    #    {
    #        push @netent, "    option 66 $tftp\n";
    #    }
    if ($logservers) {
        $logservers =~ s/,/ /g;
        push @netent, "    option 7 $logservers\n";
    } elsif ($myip) {
        push @netent, "    option 7 $myip\n";
    }
    if ($ntpservers) {
        $ntpservers =~ s/,/ /g;
        push @netent, "    option 42 $ntpservers\n";
    } elsif ($myip) {
        push @netent, "    option 42 $myip\n";
    }
    push @netent, "    option 15 \"$domain\"\n";
    if ($nameservers)
    {
        $nameservers =~ s/,/ /g;
        push @netent, "    option 6 $nameservers\n";
    }
    push @netent, "    subnet $net $range\n    {\n";
    push @netent, "    } # $net/$mask ip configuration end\n";
    push @netent, "} # $net/$mask subnet_end\n\n";

    splice(@dhcpconf, $idx, 0, @netent);
}

sub addnic
{
    if ($::XCATSITEVALS{externaldhcpservers}) { return; }
    my $nic        = shift;
    my $conf       = shift;
    my $firstindex = 0;
    my $lastindex  = 0;
    unless (grep /} # $nic nic_end/, @$conf)
    {    #add a section if not there
            #$restartdhcp=1;
            #print "Adding NIC $nic\n";
        if ($nic eq '!remote!') {
            push @$conf, "#shared-network $nic {\n";
            push @$conf, "#\} # $nic nic_end\n";
        } else {
            push @$conf, "shared-network $nic {\n";
            push @$conf, "\} # $nic nic_end\n";
        }

    }

    #return; #Don't touch it, it should already be fine..
    #my $idx=0;
    #while ($idx <= $#dhcpconf) {
    #  if ($dhcpconf[$idx] =~ /^shared-network $nic {/) {
    #    $firstindex = $idx; # found the first place to chop...
    #  } elsif ($dhcpconf[$idx] =~ /} # $nic network_end/) {
    #    $lastindex=$idx;
    #  }
    #  $idx++;
    #}
    #print Dumper(\@dhcpconf);
    #if ($firstindex and $lastindex) {
    #  splice @dhcpconf,$firstindex,($lastindex-$firstindex+1);
    #}
    #print Dumper(\@dhcpconf);
}

sub writeout
{
    if ($::XCATSITEVALS{externaldhcpservers}) { return; }

    # add the new entries to the dhcp config file
    my $targ;
    open($targ, '>', $dhcpconffile);
    my $idx;
    my $skipone;
    foreach $idx (0 .. $#dhcpconf)
    {
        #avoid writing out empty shared network declarations
        if ($dhcpconf[$idx] =~ /^shared-network/ and $dhcpconf[ $idx + 1 ] =~ /^} .* nic_end/) {
            $skipone = 1;
            next;
        } elsif ($skipone) {
            $skipone = 0;
            next;
        }
        print $targ $dhcpconf[$idx];
    }

    if ($^O eq 'aix')
    {
        # add back any NIM entries that were saved earlier
        if (@aixcfg) {
            foreach $idx (0 .. $#aixcfg)
            {
                print $targ $aixcfg[$idx];
            }
        }
    }
    close($targ);
    @dhcpconf = ();    #dispose of the file contents in memory, no longer needed
    @aixcfg   = ();


    if (@dhcp6conf) {
        open($targ, '>', $dhcp6conffile);
        foreach $idx (0 .. $#dhcp6conf)
        {
            if ($dhcp6conf[$idx] =~ /^shared-network/ and $dhcp6conf[ $idx + 1 ] =~ /^} .* nic_end/) {
                $skipone = 1;
                next;
            } elsif ($skipone) {
                $skipone = 0;
                next;
            }
            print $targ $dhcp6conf[$idx];
        }
        close($targ);
        @dhcp6conf = ();
    }
}

sub newconfig6 {
    if ($::XCATSITEVALS{externaldhcpservers}) { return; }

    #phase 1, basic working
    #phase 2, ddns too, evaluate other stuff from dhcpv4 as applicable
    push @dhcp6conf, "#xCAT generated dhcp configuration\n";
    push @dhcp6conf, "\n";
    push @dhcp6conf, "ddns-update-style interim;\n";
    push @dhcp6conf, "ignore client-updates;\n";

    #    push @dhcp6conf, "update-static-leases on;\n";
    push @dhcp6conf, "omapi-port 7912;\n";        #Enable omapi...
    push @dhcp6conf, "key xcat_key {\n";
    push @dhcp6conf, "  algorithm hmac-md5;\n";
    my $passtab = xCAT::Table->new('passwd', -create => 1);
    (my $passent) =
      $passtab->getAttribs({ key => 'omapi', username => 'xcat_key' }, 'password');
    my $secret = encode_base64(genpassword(32));    #Random from set of  62^32
    chomp $secret;
    if ($passent->{password}) { $secret = $passent->{password}; }
    else
    {
        $callback->(
            {
                data =>
                  ["The dhcp server must be restarted for OMAPI function to work"]
            }
        );
        $passtab->setAttribs({ key => 'omapi' },
            { username => 'xcat_key', password => $secret });
    }

    push @dhcp6conf, "  secret \"" . $secret . "\";\n";
    push @dhcp6conf, "};\n";
    push @dhcp6conf, "omapi-key xcat_key;\n";

    #that is all for pristine ipv6 config
}

sub newconfig
{
    if ($::XCATSITEVALS{externaldhcpservers}) { return; }
    return newconfig_aix() if ($^O eq 'aix');

    # This function puts a standard header in and enough to make omapi work.
    my $passtab = xCAT::Table->new('passwd', -create => 1);
    push @dhcpconf, "#xCAT generated dhcp configuration\n";
    push @dhcpconf, "\n";
    push @dhcpconf, "option conf-file code 209 = text;\n";
    push @dhcpconf, "option space isan;\n";
    push @dhcpconf, "option isan-encap-opts code 43 = encapsulate isan;\n";
    push @dhcpconf, "option isan.iqn code 203 = string;\n";
    push @dhcpconf, "option isan.root-path code 201 = string;\n";
    push @dhcpconf, "option space gpxe;\n";
    push @dhcpconf, "option gpxe-encap-opts code 175 = encapsulate gpxe;\n";
    push @dhcpconf, "option gpxe.bus-id code 177 = string;\n";
    push @dhcpconf, "option user-class-identifier code 77 = string;\n";
    push @dhcpconf, "option gpxe.no-pxedhcp code 176 = unsigned integer 8;\n";
    push @dhcpconf, "option tcode code 101 = text;\n";

    push @dhcpconf, "option iscsi-initiator-iqn code 203 = string;\n"; #Only via gPXE, not a standard
    push @dhcpconf, "ddns-update-style interim;\n";
    push @dhcpconf, "ignore client-updates;\n"; #Windows clients like to do all caps, very un xCAT-like

    #    push @dhcpconf, "update-static-leases on;\n"; #makedns rendered optional
    push @dhcpconf,
      "option client-architecture code 93 = unsigned integer 16;\n";
    if ($::XCATSITEVALS{timezone}) {
        push @dhcpconf, "option tcode \"" . $::XCATSITEVALS{timezone} . "\";\n";
    }
    push @dhcpconf, "option gpxe.no-pxedhcp 1;\n";
    push @dhcpconf, "\n";
    push @dhcpconf, "omapi-port 7911;\n";            #Enable omapi...
    push @dhcpconf, "key xcat_key {\n";
    push @dhcpconf, "  algorithm hmac-md5;\n";
    (my $passent) =
      $passtab->getAttribs({ key => 'omapi', username => 'xcat_key' }, 'password');
    my $secret = encode_base64(genpassword(32));     #Random from set of  62^32
    chomp $secret;
    if ($passent->{password}) { $secret = $passent->{password}; }
    else
    {
        $callback->(
            {
                data =>
                  ["The dhcp server must be restarted for OMAPI function to work"]
            }
        );
        $passtab->setAttribs({ key => 'omapi' },
            { username => 'xcat_key', password => $secret });
    }

    push @dhcpconf, "  secret \"" . $secret . "\";\n";
    push @dhcpconf, "};\n";
    push @dhcpconf, "omapi-key xcat_key;\n";
    push @dhcpconf, ('class "pxe" {' . "\n", "   match if substring (option vendor-class-identifier, 0, 9) = \"PXEClient\";\n", "   ddns-updates off;\n", "    max-lease-time 600;\n", "}\n");
}

sub newconfig_aix
{
    push @dhcpconf, "#xCAT generated dhcp configuration\n";
    push @dhcpconf, "\n";

    #push @dhcpconf, "numLogFiles 4\n";
    #push @dhcpconf, "logFileSize 100\n";
    #push @dhcpconf, "logFileName /var/log/dhcpsd.log\n";
    #push @dhcpconf, "logItem SYSERR\n";
    #push @dhcpconf, "logItem OBJERR\n";
    #push @dhcpconf, "logItem PROTERR\n";
    #push @dhcpconf, "logItem WARNING\n";
    #push @dhcpconf, "logItem EVENT\n";
    #push @dhcpconf, "logItem ACTION\n";
    #push @dhcpconf, "logItem INFO\n";
    #push @dhcpconf, "logItem ACNTING\n";
    #push @dhcpconf, "logItem TRACE\n";

    push @dhcpconf, "leaseTimeDefault 43200 seconds\n";
    push @dhcpconf, "#Network configuration begin\n";
    push @dhcpconf, "#Network configuration end\n";
}


sub genpassword
{

    #Generate a pseudo-random password of specified length
    my $length   = shift;
    my $password = '';
    my $characters =
      'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890';
    srand;    #have to reseed, rand is not rand otherwise
    while (length($password) < $length)
    {
        $password .= substr($characters, int(rand 63), 1);
    }
    return $password;
}

1;