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package dhcpd; |
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|
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=head1 dhcpd |
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|
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start with: |
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|
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perl -Ilib/PXElator -Ilib -Mdhcpd -e start |
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|
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based on L<http://www.perlmonks.org/index.pl?node_id=325248> |
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|
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=cut |
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|
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use strict; |
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use warnings; |
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|
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use autodie; |
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|
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use IO::Socket::INET; |
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use File::Slurp; |
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use Data::Dump qw/dump/; |
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use Net::Ping; |
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use Module::Refresh; |
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|
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use lib '..'; |
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use Net::DHCP::Packet; |
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use Net::DHCP::Constants 0.67; |
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|
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use server; |
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use pxe; |
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|
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my $debug = 1; |
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|
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if ( ! $server::ip ) { |
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my $server_ip = `/sbin/ifconfig`; |
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$server_ip =~ s/^.+?addr:([\d\.]+).*$/$1/gs; |
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$server::ip = $server_ip; |
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} |
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|
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warn "server ip $server::ip file: $pxe::file range: $server::ip_from - $server::ip_to\n"; |
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|
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my $addr = $server::ip_from; |
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|
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sub client_ip { |
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my ( $mac ) = @_; |
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|
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my $conf = "conf/$server::ip"; |
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mkdir $conf unless -e $conf; |
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|
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if ( -e "$conf/mac/$mac" ) { |
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my $ip = read_file "$conf/mac/$mac"; |
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print "$mac old $ip\n"; |
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return $ip; |
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} |
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|
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mkdir $_ foreach grep { ! -e $_ } map { "$conf/$_" } ( 'ip', 'mac' ); |
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|
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my $p = Net::Ping->new; |
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|
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my $prefix = $server::ip; |
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$prefix =~ s{\.\d+$}{.}; |
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my $ip = $prefix . $addr; |
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while ( -e "conf/ip/$ip" || $p->ping( $ip ) ) { |
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$ip = $prefix . $addr++; |
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die "all addresses allocated!" if $addr == $server::ip_to; |
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} |
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|
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write_file "$conf/mac/$mac", $ip; |
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if ( -l "$conf/ip/$ip" && readlink "$conf/ip/$ip" ne "$conf/mac/$mac") { |
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unlink "$conf/ip/$ip"; |
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symlink "$conf/mac/$mac", "$conf/ip/$ip"; |
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warn "$mac IP changed to $ip"; |
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} |
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|
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print "$mac NEW $ip\n"; |
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|
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return $ip; |
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} |
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|
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our $transaction = 0; # FIXME predictible transaction numbers |
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|
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sub process_packet { |
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my $sock = shift; |
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|
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my $buf; |
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$sock->recv($buf, 1024); |
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my $size = 'empty'; |
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$size = length($buf) . ' bytes' if defined $buf; |
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|
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print "packet from ",$sock->peerhost,":",$sock->peerport," $size\n"; |
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return unless $buf; |
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|
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my $dhcp = Net::DHCP::Packet->new($buf); |
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$dhcp->comment( $transaction++ ); |
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|
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warn "recv: ", $dhcp->toString; |
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|
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my $mac = substr($dhcp->chaddr(),0,$dhcp->hlen()*2); |
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my $ip = client_ip($mac); |
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|
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=for later |
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|
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my $user_class = $dhcp->getOptionValue(DHO_USER_CLASS()); |
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|
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if ( $user_class eq 'gPXE' ) { |
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$file = $gpxe_file; |
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} elsif ( ! $file ) { |
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$file = 'undionly.kpxe'; |
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} |
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|
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=cut |
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|
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my $packet = { |
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Op => BOOTREPLY(), |
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Hops => $dhcp->hops(), |
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Xid => $dhcp->xid(), |
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Flags => $dhcp->flags(), |
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Ciaddr => $dhcp->ciaddr(), |
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Yiaddr => $ip, |
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Siaddr => $server::ip, |
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Giaddr => $dhcp->giaddr(), |
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Chaddr => $dhcp->chaddr(), |
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File => $pxe::file, |
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}; |
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|
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pxe::config_for_ip( $ip ); |
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|
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my $messagetype = $dhcp->getOptionValue(DHO_DHCP_MESSAGE_TYPE()); |
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|
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if ($messagetype eq DHCPDISCOVER()) { |
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warn "DHCP DISCOVER"; |
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$packet->{Comment} = $dhcp->comment(); |
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$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPOFFER(); |
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} elsif ($messagetype eq DHCPREQUEST()) { |
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my $requested_ip = $dhcp->getOptionValue(DHO_DHCP_REQUESTED_ADDRESS()); |
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warn "DHCP REQUEST $requested_ip"; |
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if ( $ip eq $requested_ip ) { |
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$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPACK(); |
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$packet->{DHO_DHCP_LEASE_TIME()} = 5 * 60; # 5 min |
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# $packet->{DHO_DHCP_SERVER_IDENTIFIER()} = $server::ip; # FIXME |
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$packet->{DHO_SUBNET_MASK()} = '255.255.255.0'; |
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$packet->{DHO_ROUTERS()} = $server::ip; |
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# $packet->{DHO_DOMAIN_NAME()} = 'pxelator.lan'; |
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# $packet->{DHO_NAME_SERVERS()} = $server::ip; |
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# $packet->{DHO_ROOT_PATH()} = '/exports/foobar'; |
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} else { |
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$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPNAK(); |
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$packet->{DHO_DHCP_MESSAGE()} = "Bad request, expected $ip"; |
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} |
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} elsif ($messagetype eq DHCPINFORM()) { |
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warn "DHCP INFORM ignored"; |
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} else { |
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warn "$messagetype igored (bootp?)"; |
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} |
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|
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warn ">> $mac == $ip server: $server::ip", $pxe::file ? " pxe file: $pxe::file\n" : "\n"; |
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|
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$packet = new Net::DHCP::Packet( %$packet ); |
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warn "## ",$packet->toString(),"\n" if $debug; |
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|
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my $reply = IO::Socket::INET->new( |
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LocalAddr => $server::ip, |
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LocalPort => 67, |
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Proto => "udp", |
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Broadcast => 1, |
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PeerAddr => '255.255.255.255', |
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PeerPort => 68, |
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Reuse => 1, |
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) or die "socket: $@"; |
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|
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my $buff = $packet->serialize(); |
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$reply->send( $buff, 0 ) or die "Error sending: $!\n"; |
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|
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# system("arp -s $ip $mac"), |
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|
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} |
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|
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sub start { |
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|
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my $sock = IO::Socket::INET->new( |
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LocalPort => 67, |
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# LocalAddr => 'localhost', |
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# LocalAddr => '10.0.0.100', |
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LocalAddr => '0.0.0.0', |
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Proto => 'udp', |
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ReuseAddr => 1, |
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# PeerPort => getservbyname('bootpc', 'udp'), |
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Broadcast => 1, |
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Type => SOCK_DGRAM, |
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) or die "Failed to bind to socket: $@"; |
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|
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print "DHCP listen on ",$sock->sockhost,":",$sock->sockport,"\n"; |
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|
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while (1) { |
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Module::Refresh->refresh; |
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process_packet $sock; |
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} |
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} |
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|
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warn "loaded"; |
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|
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1; |
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