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 use Net::Ping;
  22
  23 use lib '..';
  24 use Net::DHCP::Packet;
  25 use Net::DHCP::Constants 0.67;
  26
  27 use server;
  28 my $debug = server::debug;
  29
  30 if ( ! $server::ip ) {
  31         my $server_ip = `/sbin/ifconfig`;
  32         $server_ip =~ s/^.+?addr:([\d\.]+).*$/$1/gs;
  33         $server::ip = $server_ip;
  34 }
  35
  36 warn "server ip $server::ip range: $server::ip_from - $server::ip_to\n";
  37
  38 my $addr = $server::ip_from;
  39
  40 sub client_ip {
  41         my ( $mac ) = @_;
  42
  43         my $conf = "$server::base_dir/conf/$server::ip";
  44         mkdir $conf unless -e $conf;
  45
  46         if ( -e "$conf/mac/$mac" ) {
  47                 my $ip = read_file "$conf/mac/$mac";
  48                 print "RENEW $mac $ip\n";
  49                 return $ip;
  50         }
  51
  52         mkdir $_ foreach grep { ! -e $_ } map { "$conf/$_" } ( 'ip', 'mac' );
  53
  54         my $p = Net::Ping->new;
  55
  56         my $prefix = $server::ip;
  57         $prefix =~ s{\.\d+$}{.};
  58         my $ip = $prefix . $addr;
  59         while ( -e "conf/ip/$ip" || $p->ping( $ip ) ) {
  60                 $ip = $prefix . $addr++;
  61                 die "all addresses allocated!" if $addr == $server::ip_to;
  62         }
  63
  64         write_file "$conf/mac/$mac", $ip;
  65         if ( -l "$conf/ip/$ip" && readlink "$conf/ip/$ip" ne "$conf/mac/$mac") {
  66                 unlink     "$conf/ip/$ip";
  67                 symlink    "$conf/mac/$mac", "$conf/ip/$ip";
  68                 warn "$mac IP changed to $ip";
  69         }
  70
  71         print "$mac NEW $ip\n";
  72
  73         return $ip;
  74 }
  75
  76 use log;
  77 use config;
  78
  79 our $file;
  80 our $transaction = 0; # FIXME predictible transaction numbers
  81
  82 sub process_packet {
  83         my $sock = shift;
  84
  85         my $buf;
  86         $sock->recv($buf, 1024);
  87         my $size = 'empty';
  88         $size = length($buf) . ' bytes' if defined $buf;
  89
  90         print "packet from ",$sock->peerhost,":",$sock->peerport," $size\n" if $debug;
  91         return unless $buf;
  92
  93         my $dhcp = Net::DHCP::Packet->new($buf);
  94         $dhcp->comment( $transaction++ );
  95
  96         warn "recv: ", $dhcp->toString if $debug;
  97
  98         my $mac = substr($dhcp->chaddr(),0,$dhcp->hlen()*2);
  99         my $ip = client_ip($mac);
 100
 101 =for later
 102
 103         my $user_class = $dhcp->getOptionValue(DHO_USER_CLASS());
 104
 105         if ( $user_class eq 'gPXE' ) {
 106                 $file = $gpxe_file;
 107         } elsif ( ! $file ) {
 108                 $file = 'undionly.kpxe';
 109         }
 110
 111 =cut
 112
 113         config::for_ip( $ip );
 114
 115         my $packet = {
 116                 Op              => BOOTREPLY(),
 117                 Hops    => $dhcp->hops(),
 118                 Xid             => $dhcp->xid(),
 119                 Flags   => $dhcp->flags(),
 120                 Ciaddr  => $dhcp->ciaddr(),
 121                 Yiaddr  => $ip,
 122                 Siaddr  => $server::ip,
 123                 Giaddr  => $dhcp->giaddr(),
 124                 Chaddr  => $dhcp->chaddr(),
 125                 File    => $file,
 126
 127                 DHO_PXELINUX_MAGIC()       => 0xF100747E,
 128                 DHO_PXELINUX_CONFIG_FILE() => 'pxelinux.cfg/default',
 129                 DHO_PXELINUX_PATH_PREFIX() => 'live-helper/tftpboot/',
 130                 DHO_PXELINUX_REBOOT_TIME() => 5, # default: 300 s
 131         };
 132
 133         my $messagetype = $dhcp->getOptionValue(DHO_DHCP_MESSAGE_TYPE());
 134
 135         if ($messagetype eq DHCPDISCOVER()) {
 136                 log::mac $mac, "DHCP DISCOVER";
 137                 $packet->{Comment} = $dhcp->comment();
 138                 $packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPOFFER();
 139         } elsif ($messagetype eq DHCPREQUEST()) {
 140                 my $requested_ip = $dhcp->getOptionValue(DHO_DHCP_REQUESTED_ADDRESS());
 141                 log::mac $mac, "DHCP REQUEST $requested_ip $ip $file";
 142                 if ( $ip eq $requested_ip ) {
 143                         $packet->{DHO_DHCP_MESSAGE_TYPE()}      = DHCPACK();
 144                         $packet->{DHO_DHCP_LEASE_TIME()}        = 5 * 60; # 5 min
 145 #                       $packet->{DHO_DHCP_SERVER_IDENTIFIER()} = $server::ip;          # FIXME
 146                         $packet->{DHO_SUBNET_MASK()}            = '255.255.255.0';
 147                         $packet->{DHO_ROUTERS()}                = $server::ip;
 148 #                       $packet->{DHO_DOMAIN_NAME()}            = 'pxelator.lan';
 149 #                       $packet->{DHO_NAME_SERVERS()}           = $server::ip;
 150 #                       $packet->{DHO_ROOT_PATH()}              = '/exports/foobar';
 151                 } else {
 152                         $packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPNAK();
 153                         $packet->{DHO_DHCP_MESSAGE()} = "Bad request, expected $ip";
 154                 }
 155         } elsif ($messagetype eq DHCPINFORM()) {
 156                 log::mac $mac, "DHCP INFORM ignored";
 157         } else {
 158                 log::mac $mac, "$messagetype igored (bootp?)";
 159         }
 160
 161         warn ">> $mac == $ip server: $server::ip", $file ? " file: $file\n" : "\n" if $debug;
 162
 163         $packet = new Net::DHCP::Packet( %$packet );
 164         warn "send ",$packet->toString() if $debug;
 165
 166         my $reply = IO::Socket::INET->new(
 167                 LocalAddr => $server::ip,
 168                 LocalPort => 67,
 169                 Proto => "udp",
 170                 Broadcast => 1,
 171                 PeerAddr => '255.255.255.255',
 172                 PeerPort => 68,
 173                 Reuse => 1,
 174         ) or die "socket: $@";
 175
 176         my $buff = $packet->serialize();
 177         $reply->send( $buff, 0 ) or die "Error sending: $!\n";
 178
 179 #       system("arp -s $ip $mac"),
 180
 181 }
 182
 183 sub start {
 184
 185         my $sock = IO::Socket::INET->new(
 186                 LocalPort       => 67,
 187 #               LocalAddr       => 'localhost',
 188 #               LocalAddr       => '10.0.0.100',
 189                 LocalAddr       => '0.0.0.0',
 190                 Proto           => 'udp',
 191                 ReuseAddr       => 1,
 192 #               PeerPort        => getservbyname('bootpc', 'udp'),
 193                 Broadcast       => 1,
 194                 Type            => SOCK_DGRAM,
 195         ) or die "Failed to bind to socket: $@";
 196
 197         print "DHCP listen on ",$sock->sockhost,":",$sock->sockport,"\n";
 198
 199         while (1) {
 200                 process_packet $sock;
 201         }
 202 }
 203
 204 warn "loaded";
 205
 206 1;