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