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 ( in_our_range( $request_ip ) ) {
  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 ip2bin { pack('C*', split(/\./, $_[0])) };
  80 sub in_our_range {
  81         my $ip = shift;
  82         return 1 if $ip eq '0.0.0.0';
  83         return 1 if (
  84                 ( ip2bin($ip)         & ip2bin($server::netmask) )
  85                 eq
  86                 ( ip2bin($server::ip) & ip2bin($server::netmask) )
  87         );
  88 }
  89
  90 sub process_packet {
  91         my $sock = shift;
  92
  93         server->refresh;
  94
  95         my $buf;
  96         $sock->recv($buf, 1024);
  97         my $size = 'empty';
  98         $size = length($buf) . ' bytes' if defined $buf;
  99
 100         print "packet from ",$sock->peerhost,":",$sock->peerport," $size\n" if $debug;
 101         return unless $buf;
 102
 103         my $dhcp = Net::DHCP::Packet->new($buf);
 104
 105         warn "recv: ", $dhcp->toString if $debug;
 106
 107         $dhcp->comment( $transaction++ );
 108
 109         my $mac = format::mac( substr($dhcp->chaddr(),0,$dhcp->hlen()*2) );
 110         my $ip = client_mac_ip($mac, $dhcp->ciaddr);
 111
 112         my $hostname = $dhcp->getOptionValue(DHO_HOST_NAME);
 113         print "$ip ", client::conf( $ip => 'hostname', default => $hostname ), " >> /etc/hosts\n" if $hostname;
 114
 115         my $audit = { mac => $mac, ip => $ip, hostname => $hostname,
 116                 options => {
 117                         map {
 118                                 ( $_ => $dhcp->getOptionValue( $_ ) )
 119                         } @{ $dhcp->{options_order} }
 120                 },
 121         };
 122
 123 =for later
 124
 125         my $user_class = $dhcp->getOptionValue(DHO_USER_CLASS());
 126
 127         if ( $user_class eq 'gPXE' ) {
 128                 $file = $gpxe_file;
 129         } elsif ( ! $file ) {
 130                 $file = 'undionly.kpxe';
 131         }
 132
 133 =cut
 134
 135         config::for_ip( $ip );
 136
 137         my $packet = {
 138                 Op              => BOOTREPLY(),
 139                 Hops    => $dhcp->hops(),
 140                 Xid             => $dhcp->xid(),
 141                 Flags   => $dhcp->flags(),
 142                 Ciaddr  => $dhcp->ciaddr(),
 143                 Yiaddr  => $ip,
 144                 Siaddr  => $server::ip,
 145                 Giaddr  => $dhcp->giaddr(),
 146                 Chaddr  => $dhcp->chaddr(),
 147                 File    => $file,
 148                 DHO_DHCP_SERVER_IDENTIFIER()    => $server::ip, # busybox/udhcpc needs it but doesn't request
 149         };
 150
 151         my $options = {
 152                 DHO_SUBNET_MASK()       => $server::netmask,
 153                 DHO_ROUTERS()           => $server::ip,
 154                 DHO_DOMAIN_NAME()       => $server::domain_name,
 155                 DHO_NAME_SERVERS()      => $server::ip,
 156                 DHO_DOMAIN_NAME_SERVERS() => $server::ip,
 157                 DHO_HOST_NAME()         => client::conf( $ip, 'hostname' ),
 158                 DHO_BROADCAST_ADDRESS() => $server::bcast,
 159 #               DHO_NTP_SERVERS() => '',
 160         };
 161
 162         my @requested = split(/\s/, $dhcp->getOptionValue(DHO_DHCP_PARAMETER_REQUEST_LIST));
 163         warn "options ",dump( $options ), ' requested: ',dump( @requested ) if $debug;
 164
 165         my @missing;
 166         foreach ( @requested ) {
 167                 if ( defined $options->{$_} ) {
 168                         $packet->{$_} = $options->{$_};
 169                 } else {
 170                         push @missing, $_;
 171                 }
 172         }
 173
 174         warn "W: options requested but missing: ",dump( @missing ),$/;
 175         $audit->{requested} = [ @requested ];
 176         $audit->{missing}   = [ @missing   ];
 177
 178         foreach my $opt ( 'magic', 'config_file', 'path_prefix', 'reboot_time' ) {
 179                 my $DH0 = eval 'DHO_PXELINUX_' . uc $opt;
 180                 warn "DH0: $@" if $@;
 181                 my $v = eval "\$pxelinux::$opt";
 182                 warn "v: $@" if $@;
 183                 next unless defined $v;
 184                 warn "pxelinux dhcp option $opt = $DH0 = $v\n" if $debug;
 185                 $packet->{ $DH0 } = $v;
 186         }
 187
 188         my $messagetype = $dhcp->getOptionValue(DHO_DHCP_MESSAGE_TYPE());
 189
 190         if ($messagetype eq DHCPDISCOVER()) {
 191                 $audit->{type} = 'discover';
 192                 $packet->{Comment} = $dhcp->comment();
 193                 $packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPOFFER();
 194         } elsif ($messagetype eq DHCPREQUEST()) {
 195                 my $requested_ip = $dhcp->getOptionValue(DHO_DHCP_REQUESTED_ADDRESS());
 196                 $audit->{type} = 'request';
 197                 if ( $ip eq $requested_ip ) {
 198                         $packet->{DHO_DHCP_MESSAGE_TYPE()}      = DHCPACK();
 199                         $packet->{DHO_DHCP_LEASE_TIME()}        = 5 * 60; # 5 min
 200 #                       $packet->{DHO_ROOT_PATH()}              = '/exports/foobar';
 201                 } else {
 202                         $packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPNAK();
 203                         $packet->{DHO_DHCP_MESSAGE()} = "Bad request, expected $ip";
 204                 }
 205         } elsif ($messagetype eq DHCPINFORM()) {
 206                 $audit->{type} = 'inform';
 207         } else {
 208                 $audit->{type} = sprintf('ignored %x', $messagetype);
 209         }
 210
 211         warn ">> $mac == $ip server: $server::ip", $file ? " file: $file\n" : "\n" if $debug;
 212         $audit->{response} = $packet;
 213
 214         $packet = new Net::DHCP::Packet( %$packet );
 215         warn "send ",$packet->toString() if $debug;
 216
 217         if ( in_our_range( $ip ) ) {
 218                 my $buff = $packet->serialize();
 219
 220                 my $reply = IO::Socket::INET->new(
 221                         LocalAddr => $server::ip,
 222                         LocalPort => 67,
 223                         Proto => "udp",
 224                         Broadcast => 1,
 225                         PeerAddr => '255.255.255.255',
 226                         PeerPort => 68,
 227                         Reuse => 1,
 228                 ) or die "socket: $@";
 229
 230                 $reply->send( $buff, 0 ) or die "Error sending: $!\n";
 231         } else {
 232                 $audit->{error} = "$ip our of our range $server::ip $server::netmask";
 233         }
 234
 235         CouchDB::audit( $audit->{type}, $audit );
 236
 237 #       system("arp -s $ip $mac"),
 238
 239 }
 240
 241 sub start {
 242
 243         my $sock = IO::Socket::INET->new(
 244                 LocalPort       => 67,
 245 #               LocalAddr       => 'localhost',
 246 #               LocalAddr       => '10.0.0.100',
 247                 LocalAddr       => '0.0.0.0',
 248                 Proto           => 'udp',
 249                 ReuseAddr       => 1,
 250 #               PeerPort        => getservbyname('bootpc', 'udp'),
 251                 Broadcast       => 1,
 252                 Type            => SOCK_DGRAM,
 253         ) or die "Failed to bind to socket: $@";
 254
 255         print "DHCP listen on ",$sock->sockhost,":",$sock->sockport,"\n";
 256
 257         CouchDB::audit( 'start', { addr => $sock->sockhost, port => $sock->sockport } );
 258
 259         while (1) {
 260                 process_packet $sock;
 261         }
 262 }
 263
 264 warn "loaded";
 265
 266 1;