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 CouchDB;
  27 use format;
  28
  29 use server;
  30 my $debug = server::debug;
  31
  32 if ( ! $server::ip ) {
  33         my $server_ip = `/sbin/ifconfig`;
  34         $server_ip =~ s/^.+?addr:([\d\.]+).*$/$1/gs;
  35         $server::ip = $server_ip;
  36 }
  37
  38 warn "server ip $server::ip range: $server::ip_from - $server::ip_to\n";
  39
  40 use client;
  41
  42 sub client_mac_ip {
  43         my ( $mac, $request_ip ) = @_;
  44
  45         if ( ! $mac ) {
  46                 warn "W: no mac in requiest\n";
  47                 return;
  48         }
  49
  50         my $conf = $server::conf;
  51         mkdir $conf unless -e $conf;
  52
  53         my $ip;
  54
  55         if ( $ip = client::ip_from_mac( $mac ) ) {
  56                 print "RENEW $mac $ip\n";
  57                 client::save_ip_mac( $ip, $mac );
  58                 return $ip;
  59         } elsif ( ip::in_dhcp_range( $request_ip ) || $request_ip eq '0.0.0.0' ) {
  60                 $ip = client::next_ip( $mac );
  61                 print "NEW $mac $ip\n";
  62         } else {
  63                 $ip = $request_ip;
  64                 client::save_ip_mac( $ip, $mac );
  65                 warn "W: $ip our of server range $server::ip $server::netmask\n";
  66         }
  67
  68         return $ip;
  69 }
  70
  71 use log;
  72 use config;
  73 use pxelinux;
  74 use client;
  75
  76 our $file;
  77 our $transaction = 0; # FIXME predictible transaction numbers
  78
  79 sub process_packet {
  80         my $sock = shift;
  81
  82         server->refresh;
  83
  84         my $buf;
  85         $sock->recv($buf, 1024);
  86         my $size = 'empty';
  87         $size = length($buf) . ' bytes' if defined $buf;
  88
  89         print "packet from ",$sock->peerhost,":",$sock->peerport," $size\n" if $debug;
  90         return unless $buf;
  91
  92         my $dhcp = Net::DHCP::Packet->new($buf);
  93
  94         warn "recv: ", $dhcp->toString if $debug;
  95
  96         $dhcp->comment( $transaction++ );
  97
  98         my $mac = format::mac( substr($dhcp->chaddr(),0,$dhcp->hlen()*2) );
  99         my $ip = client_mac_ip($mac, $dhcp->ciaddr);
 100
 101         my $hostname = $dhcp->getOptionValue(DHO_HOST_NAME);
 102         print "$ip ", client::conf( $ip => 'hostname', default => $hostname ), " >> /etc/hosts\n" if $hostname;
 103
 104         my $audit = { mac => $mac, ip => $ip, hostname => $hostname,
 105                 options => {
 106                         map {
 107                                 ( $_ => $dhcp->getOptionValue( $_ ) )
 108                         } @{ $dhcp->{options_order} }
 109                 },
 110         };
 111
 112 =for later
 113
 114         my $user_class = $dhcp->getOptionValue(DHO_USER_CLASS());
 115
 116         if ( $user_class eq 'gPXE' ) {
 117                 $file = $gpxe_file;
 118         } elsif ( ! $file ) {
 119                 $file = 'undionly.kpxe';
 120         }
 121
 122 =cut
 123
 124         config::for_ip( $ip );
 125
 126         my $packet = {
 127                 Op              => BOOTREPLY(),
 128                 Hops    => $dhcp->hops(),
 129                 Xid             => $dhcp->xid(),
 130                 Flags   => $dhcp->flags(),
 131                 Ciaddr  => $dhcp->ciaddr(),
 132                 Yiaddr  => $ip,
 133                 Siaddr  => $server::ip,
 134                 Giaddr  => $dhcp->giaddr(),
 135                 Chaddr  => $dhcp->chaddr(),
 136                 File    => $file,
 137                 DHO_DHCP_SERVER_IDENTIFIER()    => $server::ip, # busybox/udhcpc needs it but doesn't request
 138         };
 139
 140         my $options = {
 141                 DHO_SUBNET_MASK()       => $server::netmask,
 142                 DHO_ROUTERS()           => $server::ip,
 143                 DHO_DOMAIN_NAME()       => $server::domain,
 144                 DHO_NAME_SERVERS()      => $server::ip,
 145                 DHO_DOMAIN_NAME_SERVERS() => $server::ip,
 146                 DHO_HOST_NAME()         => client::conf( $ip, 'hostname' ),
 147                 DHO_BROADCAST_ADDRESS() => $server::bcast,
 148 #               DHO_NTP_SERVERS() => '',
 149         };
 150
 151         my @requested = split(/\s/, $dhcp->getOptionValue(DHO_DHCP_PARAMETER_REQUEST_LIST));
 152         warn "options ",dump( $options ), ' requested: ',dump( @requested ) if $debug;
 153
 154         my @missing;
 155         foreach ( @requested ) {
 156                 if ( defined $options->{$_} ) {
 157                         $packet->{$_} = $options->{$_};
 158                 } else {
 159                         push @missing, $_;
 160                 }
 161         }
 162
 163         warn "W: options requested but missing: ",dump( @missing ),$/;
 164         $audit->{requested} = [ @requested ];
 165         $audit->{missing}   = [ @missing   ];
 166
 167         foreach my $opt ( 'magic', 'config_file', 'path_prefix', 'reboot_time' ) {
 168                 my $DH0 = eval 'DHO_PXELINUX_' . uc $opt;
 169                 warn "DH0: $@" if $@;
 170                 my $v = eval "\$pxelinux::$opt";
 171                 warn "v: $@" if $@;
 172                 next unless defined $v;
 173                 warn "pxelinux dhcp option $opt = $DH0 = $v\n" if $debug;
 174                 $packet->{ $DH0 } = $v;
 175         }
 176
 177         my $messagetype = $dhcp->getOptionValue(DHO_DHCP_MESSAGE_TYPE());
 178
 179         my @type;
 180
 181         if ($messagetype eq DHCPDISCOVER()) {
 182                 $packet->{Comment} = $dhcp->comment();
 183                 $packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPOFFER();
 184                 @type = qw( discover offer );
 185         } elsif ($messagetype eq DHCPREQUEST()) {
 186                 @type = qw( request );
 187                 my $requested_ip = $dhcp->getOptionValue(DHO_DHCP_REQUESTED_ADDRESS()) || $dhcp->ciaddr();
 188                 if ( $ip eq $requested_ip ) {
 189                         $packet->{DHO_DHCP_MESSAGE_TYPE()}      = DHCPACK();
 190                         $packet->{DHO_DHCP_LEASE_TIME()}        = 5 * 60; # 5 min
 191 #                       $packet->{DHO_ROOT_PATH()}              = '/exports/foobar';
 192                         $type[1] = 'ack';
 193                 } else {
 194                         $packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPNAK();
 195                         $packet->{DHO_DHCP_MESSAGE()} = "Bad request, expected $ip got $requested_ip";
 196                         $type[1] = 'nak';
 197                 }
 198         } elsif ($messagetype eq DHCPINFORM()) {
 199                 @type = qw( inform ignored );
 200         } else {
 201                 @type = ( $messagetype, 'ignored' );
 202         }
 203
 204         warn "# type ",dump @type;
 205         $audit->{type} = [ @type ];
 206
 207         $audit->{response} = $packet;
 208
 209         $packet = new Net::DHCP::Packet( %$packet );
 210         warn "send ",$packet->toString() if $debug;
 211
 212         if ( ip::in_dhcp_range( $ip ) ) {
 213                 my $buff = $packet->serialize();
 214
 215                 my $reply = IO::Socket::INET->new(
 216                         LocalAddr => $server::ip,
 217                         LocalPort => 67,
 218                         Proto => "udp",
 219                         Broadcast => 1,
 220                         PeerAddr => '255.255.255.255',
 221                         PeerPort => 68,
 222                         Reuse => 1,
 223                 ) or die "socket: $@";
 224
 225                 $reply->send( $buff, 0 ) or die "Error sending: $!\n";
 226                 warn ">> $mac == $ip server: $server::ip", $file ? " file: $file\n" : "\n";
 227         } else {
 228                 $audit->{error} = "$ip our of our range $server::ip $server::netmask";
 229                 warn $audit->{error};
 230         }
 231
 232         CouchDB::audit( @type, $audit );
 233
 234 #       system("arp -s $ip $mac"),
 235
 236 }
 237
 238 sub start {
 239
 240         my $sock = IO::Socket::INET->new(
 241                 LocalPort       => 67,
 242 #               LocalAddr       => 'localhost',
 243 #               LocalAddr       => '10.0.0.100',
 244                 LocalAddr       => '0.0.0.0',
 245                 Proto           => 'udp',
 246                 ReuseAddr       => 1,
 247 #               PeerPort        => getservbyname('bootpc', 'udp'),
 248                 Broadcast       => 1,
 249                 Type            => SOCK_DGRAM,
 250         ) or die "Failed to bind to socket: $@";
 251
 252         print "DHCP listen on ",$sock->sockhost,":",$sock->sockport,"\n";
 253
 254         CouchDB::audit( 'start', { addr => $sock->sockhost, port => $sock->sockport } );
 255
 256         while (1) {
 257                 process_packet $sock;
 258         }
 259 }
 260
 261 warn "loaded";
 262
 263 1;