3 # based on http://www.perlmonks.org/index.pl?node_id=325248
10 use Net::DHCP::Constants;
12 use Data::Dump qw/dump/;
14 die "need to run $0 as root like this\nsudo $0\n" unless $< == 0;
16 my $debug = shift @ARGV;
18 our ( $file, $next_file );
19 our ( $ip_from, $ip_to ) = ( 10, 100 );
21 our $server_ip = readlink 'conf/server.ip';
23 my $sock = IO::Socket::INET->new(
25 # LocalAddr => 'localhost',
26 # LocalAddr => '10.0.0.100',
27 LocalAddr => '0.0.0.0',
30 # PeerPort => getservbyname('bootpc', 'udp'),
33 ) or die "Failed to bind to socket: $@";
41 my $conf = "conf/$server_ip";
42 mkdir $conf unless -e $conf;
44 if ( -e "$conf/$mac" ) {
45 my $ip = read_file "conf/mac/$mac";
46 print "$mac old $ip\n";
50 mkdir $_ foreach grep { ! -e $_ } map { "$conf/$_" } ( 'ip', 'mac' );
52 my $prefix = $server_ip;
53 $prefix =~ s{\.\d+$}{.};
54 my $ip = $prefix . $addr;
55 while ( -e "conf/ip/$ip" ) {
56 $ip = $prefix . $addr++;
57 die "all addresses allocated!" if $addr == $ip_to;
60 write_file "$conf/mac/$mac", $ip;
61 symlink "$conf/mac/$mac", "conf/ip/$ip";
63 print "$mac NEW $ip\n";
70 require "config.pl"; # refresh config
72 print "waiting for DHCP requests on ",$sock->sockhost,":",$sock->sockport,"\n";
75 $sock->recv($buf, 1024);
76 print "<< ",$sock->peerhost,":",$sock->peerport,"\n";
82 eval { $dhcp = Net::DHCP::Packet->new($buf); };
83 die "can't use request", dump( $buf ) if $@;
86 warn "recv: ", $dhcp->toString, "\n\n";
89 my $mac = substr($dhcp->chaddr(),0,$dhcp->hlen()*2);
90 my $ip = client_ip($mac);
93 if ( $dhcp->getOptionValue(DHO_USER_CLASS()) ne 'gPXE' ) {
94 $file = 'undionly.kpxe';
100 my $packet = new Net::DHCP::Packet(
102 Hops => $dhcp->hops(),
104 Flags => $dhcp->flags(),
105 Ciaddr => $dhcp->ciaddr(),
107 Siaddr => $server_ip,
108 Giaddr => $dhcp->giaddr(),
109 Chaddr => $dhcp->chaddr(),
111 # DHO_DHCP_MESSAGE_TYPE() => DHCPACK(),
112 DHO_SUBNET_MASK() => '255.0.0.0',
115 warn ">> $mac == $ip server $server_ip\n";
117 warn "## ",$packet->toString(),"\n" if $debug;
119 my $reply = IO::Socket::INET->new(
120 LocalAddr => $server_ip,
124 PeerAddr => '255.255.255.255',
127 ) or die "socket: $@";
129 my $buff = $packet->serialize();
130 $reply->send( $buff, 0 ) or die "Error sending: $!\n";
132 # system("arp -s $ip $mac"),
135 print "No bootp request.\n";