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 out 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         my $buf;
  83         $sock->recv($buf, 1024);
  84         my $size = 'empty';
  85         $size = length($buf) . ' bytes' if defined $buf;
  86
  87         print "packet from ",$sock->peerhost,":",$sock->peerport," $size\n" if $debug;
  88         return unless $buf;
  89
  90         my $dhcp = Net::DHCP::Packet->new($buf);
  91
  92         warn "recv: ", $dhcp->toString if $debug;
  93
  94         $dhcp->comment( $transaction++ );
  95
  96         my $mac = format::mac( substr($dhcp->chaddr(),0,$dhcp->hlen()*2) );
  97         my $ip = client_mac_ip($mac, $dhcp->ciaddr);
  98
  99         my $hostname = $dhcp->getOptionValue(DHO_HOST_NAME);
 100         print "$ip ", client::conf( $ip => 'hostname', default => $hostname ), " >> /etc/hosts\n" if $hostname;
 101
 102         my $audit = { mac => $mac, ip => $ip, hostname => $hostname,
 103                 options => {
 104                         map {
 105                                 ( $_ => $dhcp->getOptionValue( $_ ) )
 106                         } @{ $dhcp->{options_order} }
 107                 },
 108         };
 109
 110 =for later
 111
 112         my $user_class = $dhcp->getOptionValue(DHO_USER_CLASS());
 113
 114         if ( $user_class eq 'gPXE' ) {
 115                 $file = $gpxe_file;
 116         } elsif ( ! $file ) {
 117                 $file = 'undionly.kpxe';
 118         }
 119
 120 =cut
 121
 122         config::for_ip( $ip );
 123
 124         my $server;
 125         map { $server->{ $_ } = eval '$server::' . $_ } ( 'ip', 'netmask', 'bcast', 'domain' );
 126
 127         if ( my $force = client::conf( $ip => 'dhcpd.pl' ) ) {
 128                 eval $force;
 129                 die "$force\n$@" if $@;
 130                 warn "force server ", dump $server;
 131         }
 132
 133         my $packet = {
 134                 Op              => BOOTREPLY(),
 135                 Hops    => $dhcp->hops(),
 136                 Xid             => $dhcp->xid(),
 137                 Flags   => $dhcp->flags(),
 138                 Ciaddr  => $dhcp->ciaddr(),
 139                 Yiaddr  => $ip,
 140                 Siaddr  => $server->{ip},
 141                 Giaddr  => $dhcp->giaddr(),
 142                 Chaddr  => $dhcp->chaddr(),
 143                 File    => $file,
 144                 DHO_DHCP_SERVER_IDENTIFIER()    => $server->{ip},       # busybox/udhcpc needs it but doesn't request
 145         };
 146
 147         my $options = {
 148                 DHO_SUBNET_MASK()       => $server->{netmask},
 149                 DHO_ROUTERS()           => $server->{ip},
 150                 DHO_DOMAIN_NAME()       => $server->{domain},
 151                 DHO_NAME_SERVERS()      => $server->{ip},
 152                 DHO_DOMAIN_NAME_SERVERS() => $server->{ip},
 153                 DHO_HOST_NAME()         => client::conf( $ip, 'hostname' ),
 154                 DHO_BROADCAST_ADDRESS() => $server->{bcast},
 155 #               DHO_NTP_SERVERS() => '',
 156         };
 157
 158         my @requested = split(/\s/, $dhcp->getOptionValue(DHO_DHCP_PARAMETER_REQUEST_LIST));
 159         warn "options ",dump( $options ), ' requested: ',dump( @requested ) if $debug;
 160
 161         my @missing;
 162         foreach ( @requested ) {
 163                 if ( defined $options->{$_} ) {
 164                         $packet->{$_} = $options->{$_};
 165                 } else {
 166                         push @missing, $_;
 167                 }
 168         }
 169
 170         warn "W: options requested but missing: ",dump( @missing ),$/;
 171         $audit->{requested} = [ @requested ];
 172         $audit->{missing}   = [ @missing   ];
 173
 174         foreach my $opt ( 'magic', 'config_file', 'path_prefix', 'reboot_time' ) {
 175                 my $DH0 = eval 'DHO_PXELINUX_' . uc $opt;
 176                 warn "DH0: $@" if $@;
 177                 my $v = eval "\$pxelinux::$opt";
 178                 warn "v: $@" if $@;
 179                 next unless defined $v;
 180                 warn "pxelinux dhcp option $opt = $DH0 = $v\n" if $debug;
 181                 $packet->{ $DH0 } = $v;
 182         }
 183
 184         my $messagetype = $dhcp->getOptionValue(DHO_DHCP_MESSAGE_TYPE());
 185
 186         my @type;
 187
 188         if ($messagetype eq DHCPDISCOVER()) {
 189                 $packet->{Comment} = $dhcp->comment();
 190                 $packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPOFFER();
 191                 @type = qw( discover offer );
 192         } elsif ($messagetype eq DHCPREQUEST()) {
 193                 @type = qw( request );
 194                 my $requested_ip = $dhcp->getOptionValue(DHO_DHCP_REQUESTED_ADDRESS()) || $dhcp->ciaddr();
 195                 if ( $ip eq $requested_ip ) {
 196                         $packet->{DHO_DHCP_MESSAGE_TYPE()}      = DHCPACK();
 197                         $packet->{DHO_DHCP_LEASE_TIME()}        = 5 * 60; # 5 min
 198 #                       $packet->{DHO_ROOT_PATH()}              = '/exports/foobar';
 199                         $type[1] = 'ack';
 200                 } else {
 201                         $packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPNAK();
 202                         $packet->{DHO_DHCP_MESSAGE()} = "Bad request, expected $ip got $requested_ip";
 203                         $type[1] = 'nak';
 204                 }
 205         } elsif ($messagetype eq DHCPINFORM()) {
 206                 @type = qw( inform ignored );
 207         } else {
 208                 @type = ( $messagetype, 'ignored' );
 209         }
 210
 211         warn "# type ",dump @type;
 212         $audit->{type} = [ @type ];
 213
 214         $audit->{response} = $packet;
 215
 216         $packet = new Net::DHCP::Packet( %$packet );
 217         warn "send ",$packet->toString() if $debug;
 218
 219         if ( ip::in_dhcp_range( $ip ) ) {
 220                 my $buff = $packet->serialize();
 221
 222                 my $reply = IO::Socket::INET->new(
 223                         LocalAddr => $server->{ip},
 224                         LocalPort => 67,
 225                         Proto => "udp",
 226                         Broadcast => 1,
 227 #                       PeerAddr => '255.255.255.255',
 228                         PeerAddr => $server->{bcast},
 229                         PeerPort => 68,
 230                         Reuse => 1,
 231                 ) or die "socket: $@";
 232
 233                 $reply->send( $buff, 0 ) or die "Error sending: $!\n";
 234                 warn ">> $mac == $ip server: $server->{ip}", $file ? " file: $file\n" : "\n";
 235         } else {
 236                 $audit->{error} = "$ip not in server range $server::ip $server::netmask - no packet sent";
 237                 warn $audit->{error};
 238         }
 239
 240         CouchDB::audit( @type, $audit );
 241
 242 #       system("arp -s $ip $mac"),
 243
 244 }
 245
 246 sub start {
 247
 248         my $sock = IO::Socket::INET->new(
 249                 LocalPort       => 67,
 250 #               LocalAddr       => 'localhost',
 251 #               LocalAddr       => '10.0.0.100',
 252                 LocalAddr       => '0.0.0.0',
 253                 Proto           => 'udp',
 254                 ReuseAddr       => 1,
 255 #               PeerPort        => getservbyname('bootpc', 'udp'),
 256                 Broadcast       => 1,
 257                 Type            => SOCK_DGRAM,
 258         ) or die "Failed to bind to socket: $@";
 259
 260         print "DHCP listen on ",$sock->sockhost,":",$sock->sockport,"\n";
 261
 262         CouchDB::audit( 'start', { addr => $sock->sockhost, port => $sock->sockport } );
 263
 264         while (1) {
 265                 server->refresh;
 266                 process_packet $sock;
 267         }
 268 }
 269
 270 warn "loaded";
 271
 272 1;