git.rot13.org Git - pxelator/blob - lib/PXElator/dhcpd.pm

   1 package dhcpd;
   2
   3 =head1 dhcpd
   4
   5 start with:
   6
   7  perl -Ilib/PXElator -Ilib -Mdhcpd -e start
   8
   9 based on L<http://www.perlmonks.org/index.pl?node_id=325248>
  10
  11 =cut
  12
  13 use strict;
  14 use warnings;
  15
  16 use autodie;
  17
  18 use IO::Socket::INET;
  19 use File::Slurp;
  20 use Data::Dump qw/dump/;
  21
  22 use lib '..';
  23 use Net::DHCP::Packet;
  24 use Net::DHCP::Constants 0.67;
  25
  26 use server;
  27 my $debug = server::debug;
  28
  29 if ( ! $server::ip ) {
  30         my $server_ip = `/sbin/ifconfig`;
  31         $server_ip =~ s/^.+?addr:([\d\.]+).*$/$1/gs;
  32         $server::ip = $server_ip;
  33 }
  34
  35 warn "server ip $server::ip range: $server::ip_from - $server::ip_to\n";
  36
  37 use client;
  38
  39 sub client_ip {
  40         my ( $mac ) = @_;
  41
  42         my $conf = $server::conf;
  43         mkdir $conf unless -e $conf;
  44
  45         my $ip;
  46
  47         if ( $ip = client::ip_from_mac( $mac ) ) {
  48                 print "RENEW $mac $ip\n";
  49                 return $ip;
  50         } else {
  51                 $ip = client::next_ip( $mac );
  52                 print "NEW $mac $ip\n";
  53         }
  54
  55         return $ip;
  56 }
  57
  58 use log;
  59 use config;
  60 use pxelinux;
  61 use client;
  62
  63 our $file;
  64 our $transaction = 0; # FIXME predictible transaction numbers
  65
  66 sub process_packet {
  67         my $sock = shift;
  68
  69         server->refresh;
  70
  71         my $buf;
  72         $sock->recv($buf, 1024);
  73         my $size = 'empty';
  74         $size = length($buf) . ' bytes' if defined $buf;
  75
  76         print "packet from ",$sock->peerhost,":",$sock->peerport," $size\n" if $debug;
  77         return unless $buf;
  78
  79         my $dhcp = Net::DHCP::Packet->new($buf);
  80         $dhcp->comment( $transaction++ );
  81
  82         warn "recv: ", $dhcp->toString if $debug;
  83
  84         my $mac = substr($dhcp->chaddr(),0,$dhcp->hlen()*2);
  85         my $ip = client_ip($mac);
  86
  87 =for later
  88
  89         my $user_class = $dhcp->getOptionValue(DHO_USER_CLASS());
  90
  91         if ( $user_class eq 'gPXE' ) {
  92                 $file = $gpxe_file;
  93         } elsif ( ! $file ) {
  94                 $file = 'undionly.kpxe';
  95         }
  96
  97 =cut
  98
  99         config::for_ip( $ip );
 100
 101         my $packet = {
 102                 Op              => BOOTREPLY(),
 103                 Hops    => $dhcp->hops(),
 104                 Xid             => $dhcp->xid(),
 105                 Flags   => $dhcp->flags(),
 106                 Ciaddr  => $dhcp->ciaddr(),
 107                 Yiaddr  => $ip,
 108                 Siaddr  => $server::ip,
 109                 Giaddr  => $dhcp->giaddr(),
 110                 Chaddr  => $dhcp->chaddr(),
 111                 File    => $file,
 112                 DHO_DHCP_SERVER_IDENTIFIER()    => $server::ip, # busybox/udhcpc needs it but doesn't request
 113         };
 114
 115         my $options = {
 116                 DHO_SUBNET_MASK()       => $server::netmask,
 117                 DHO_ROUTERS()           => $server::ip,
 118                 DHO_DOMAIN_NAME()       => $server::domain_name,
 119                 DHO_NAME_SERVERS()      => $server::ip,
 120                 DHO_DOMAIN_NAME_SERVERS() => $server::ip,
 121                 DHO_HOST_NAME()         => client::conf( $ip, 'hostname' ),
 122                 DHO_BROADCAST_ADDRESS() => $server::bcast,
 123 #               DHO_NTP_SERVERS() => '',
 124         };
 125
 126         my @requested = split(/\s/, $dhcp->getOptionValue(DHO_DHCP_PARAMETER_REQUEST_LIST));
 127         warn "options ",dump( $options ), ' requested: ',dump( @requested ) if $debug;
 128
 129         my @missing;
 130         foreach ( @requested ) {
 131                 if ( defined $options->{$_} ) {
 132                         $packet->{$_} = $options->{$_};
 133                 } else {
 134                         push @missing, $_;
 135                 }
 136         }
 137
 138         warn "W: options requested but missing: ",dump( @missing ),$/;
 139
 140         foreach my $opt ( 'magic', 'config_file', 'path_prefix', 'reboot_time' ) {
 141                 my $DH0 = eval 'DHO_PXELINUX_' . uc $opt;
 142                 warn "DH0: $@" if $@;
 143                 my $v = eval "\$pxelinux::$opt";
 144                 warn "v: $@" if $@;
 145                 next unless defined $v;
 146                 warn "pxelinux dhcp option $opt = $DH0 = $v\n" if $debug;
 147                 $packet->{ $DH0 } = $v;
 148         }
 149
 150         my $messagetype = $dhcp->getOptionValue(DHO_DHCP_MESSAGE_TYPE());
 151
 152         if ($messagetype eq DHCPDISCOVER()) {
 153                 log::mac $mac, "DHCP DISCOVER";
 154                 $packet->{Comment} = $dhcp->comment();
 155                 $packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPOFFER();
 156         } elsif ($messagetype eq DHCPREQUEST()) {
 157                 my $requested_ip = $dhcp->getOptionValue(DHO_DHCP_REQUESTED_ADDRESS());
 158                 log::mac $mac, "DHCP REQUEST $requested_ip $ip $file";
 159                 if ( $ip eq $requested_ip ) {
 160                         $packet->{DHO_DHCP_MESSAGE_TYPE()}      = DHCPACK();
 161                         $packet->{DHO_DHCP_LEASE_TIME()}        = 5 * 60; # 5 min
 162 #                       $packet->{DHO_ROOT_PATH()}              = '/exports/foobar';
 163                 } else {
 164                         $packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPNAK();
 165                         $packet->{DHO_DHCP_MESSAGE()} = "Bad request, expected $ip";
 166                 }
 167         } elsif ($messagetype eq DHCPINFORM()) {
 168                 log::mac $mac, "DHCP INFORM ignored";
 169         } else {
 170                 log::mac $mac, "$messagetype igored (bootp?)";
 171         }
 172
 173         warn ">> $mac == $ip server: $server::ip", $file ? " file: $file\n" : "\n" if $debug;
 174
 175         $packet = new Net::DHCP::Packet( %$packet );
 176         warn "send ",$packet->toString() if $debug;
 177
 178         my $reply = IO::Socket::INET->new(
 179                 LocalAddr => $server::ip,
 180                 LocalPort => 67,
 181                 Proto => "udp",
 182                 Broadcast => 1,
 183                 PeerAddr => '255.255.255.255',
 184                 PeerPort => 68,
 185                 Reuse => 1,
 186         ) or die "socket: $@";
 187
 188         my $buff = $packet->serialize();
 189         $reply->send( $buff, 0 ) or die "Error sending: $!\n";
 190
 191 #       system("arp -s $ip $mac"),
 192
 193 }
 194
 195 sub start {
 196
 197         my $sock = IO::Socket::INET->new(
 198                 LocalPort       => 67,
 199 #               LocalAddr       => 'localhost',
 200 #               LocalAddr       => '10.0.0.100',
 201                 LocalAddr       => '0.0.0.0',
 202                 Proto           => 'udp',
 203                 ReuseAddr       => 1,
 204 #               PeerPort        => getservbyname('bootpc', 'udp'),
 205                 Broadcast       => 1,
 206                 Type            => SOCK_DGRAM,
 207         ) or die "Failed to bind to socket: $@";
 208
 209         print "DHCP listen on ",$sock->sockhost,":",$sock->sockport,"\n";
 210
 211         while (1) {
 212                 process_packet $sock;
 213         }
 214 }
 215
 216 warn "loaded";
 217
 218 1;