lib/PXElator/dhcpd.pm

package dhcpd;

=head1 dhcpd

start with:

 perl -Ilib/PXElator -Ilib -Mdhcpd -e start

based on L<http://www.perlmonks.org/index.pl?node_id=325248>

=cut

use strict;
use warnings;

use autodie;

use IO::Socket::INET;
use File::Slurp;
use Data::Dump qw/dump/;

use lib '..';
use Net::DHCP::Packet;
use Net::DHCP::Constants 0.67;

use server;
my $debug = server::debug;

if ( ! $server::ip ) {
        my $server_ip = `/sbin/ifconfig`;
        $server_ip =~ s/^.+?addr:([\d\.]+).*$/$1/gs;
        $server::ip = $server_ip;
}

warn "server ip $server::ip range: $server::ip_from - $server::ip_to\n";

use client;

sub client_ip {
        my ( $mac ) = @_;

        my $conf = $server::conf;
        mkdir $conf unless -e $conf;

        my $ip;

        if ( $ip = client::ip_from_mac( $mac ) ) {
                print "RENEW $mac $ip\n";
                return $ip;
        } else {
                $ip = client::next_ip( $mac );
                print "NEW $mac $ip\n";
        }

        return $ip;
}

use log;
use config;
use pxelinux;
use client;

our $file;
our $transaction = 0; # FIXME predictible transaction numbers

sub process_packet {
        my $sock = shift;

        server->refresh;

        my $buf;
        $sock->recv($buf, 1024);
        my $size = 'empty';
        $size = length($buf) . ' bytes' if defined $buf;

        print "packet from ",$sock->peerhost,":",$sock->peerport," $size\n" if $debug;
        return unless $buf;

        my $dhcp = Net::DHCP::Packet->new($buf);
        $dhcp->comment( $transaction++ );

        warn "recv: ", $dhcp->toString if $debug;

        my $mac = substr($dhcp->chaddr(),0,$dhcp->hlen()*2);
        my $ip = client_ip($mac);

=for later

        my $user_class = $dhcp->getOptionValue(DHO_USER_CLASS());

        if ( $user_class eq 'gPXE' ) {
                $file = $gpxe_file;
        } elsif ( ! $file ) {
                $file = 'undionly.kpxe';
        }

=cut

        config::for_ip( $ip );

        my $packet = {
                Op              => BOOTREPLY(),
                Hops    => $dhcp->hops(),
                Xid             => $dhcp->xid(),
                Flags   => $dhcp->flags(),
                Ciaddr  => $dhcp->ciaddr(),
                Yiaddr  => $ip,
                Siaddr  => $server::ip,
                Giaddr  => $dhcp->giaddr(),
                Chaddr  => $dhcp->chaddr(),
                File    => $file,
                DHO_DHCP_SERVER_IDENTIFIER()    => $server::ip, # busybox/udhcpc needs it but doesn't request
        };

        my $options = {
                DHO_SUBNET_MASK()       => $server::netmask,
                DHO_ROUTERS()           => $server::ip,
                DHO_DOMAIN_NAME()       => $server::domain_name,
                DHO_NAME_SERVERS()      => $server::ip,
                DHO_DOMAIN_NAME_SERVERS() => $server::ip,
                DHO_HOST_NAME()         => client::conf( $ip, 'hostname' ),
                DHO_BROADCAST_ADDRESS() => $server::bcast,
#               DHO_NTP_SERVERS() => '',
        };

        my @requested = split(/\s/, $dhcp->getOptionValue(DHO_DHCP_PARAMETER_REQUEST_LIST));
        warn "options ",dump( $options ), ' requested: ',dump( @requested ) if $debug;

        my @missing;
        foreach ( @requested ) {
                if ( defined $options->{$_} ) {
                        $packet->{$_} = $options->{$_};
                } else {
                        push @missing, $_;
                }
        }

        warn "W: options requested but missing: ",dump( @missing ),$/;

        foreach my $opt ( 'magic', 'config_file', 'path_prefix', 'reboot_time' ) {
                my $DH0 = eval 'DHO_PXELINUX_' . uc $opt;
                warn "DH0: $@" if $@;
                my $v = eval "\$pxelinux::$opt";
                warn "v: $@" if $@;
                next unless defined $v;
                warn "pxelinux dhcp option $opt = $DH0 = $v\n" if $debug;
                $packet->{ $DH0 } = $v;
        }

        my $messagetype = $dhcp->getOptionValue(DHO_DHCP_MESSAGE_TYPE());

        if ($messagetype eq DHCPDISCOVER()) {
                log::mac $mac, "DHCP DISCOVER";
                $packet->{Comment} = $dhcp->comment();
                $packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPOFFER();
        } elsif ($messagetype eq DHCPREQUEST()) {
                my $requested_ip = $dhcp->getOptionValue(DHO_DHCP_REQUESTED_ADDRESS());
                log::mac $mac, "DHCP REQUEST $requested_ip $ip $file";
                if ( $ip eq $requested_ip ) {
                        $packet->{DHO_DHCP_MESSAGE_TYPE()}      = DHCPACK();
                        $packet->{DHO_DHCP_LEASE_TIME()}        = 5 * 60; # 5 min
#                       $packet->{DHO_ROOT_PATH()}              = '/exports/foobar';
                } else {
                        $packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPNAK();
                        $packet->{DHO_DHCP_MESSAGE()} = "Bad request, expected $ip";
                }
        } elsif ($messagetype eq DHCPINFORM()) {
                log::mac $mac, "DHCP INFORM ignored";
        } else {
                log::mac $mac, "$messagetype igored (bootp?)";
        }

        warn ">> $mac == $ip server: $server::ip", $file ? " file: $file\n" : "\n" if $debug;

        $packet = new Net::DHCP::Packet( %$packet );
        warn "send ",$packet->toString() if $debug;

        my $reply = IO::Socket::INET->new(
                LocalAddr => $server::ip,
                LocalPort => 67,
                Proto => "udp",
                Broadcast => 1,
                PeerAddr => '255.255.255.255',
                PeerPort => 68,
                Reuse => 1,
        ) or die "socket: $@";

        my $buff = $packet->serialize();
        $reply->send( $buff, 0 ) or die "Error sending: $!\n";

#       system("arp -s $ip $mac"),

}

sub start {

        my $sock = IO::Socket::INET->new(
                LocalPort       => 67,
#               LocalAddr       => 'localhost',
#               LocalAddr       => '10.0.0.100',
                LocalAddr       => '0.0.0.0',
                Proto           => 'udp',
                ReuseAddr       => 1,
#               PeerPort        => getservbyname('bootpc', 'udp'),
                Broadcast       => 1,
                Type            => SOCK_DGRAM,
        ) or die "Failed to bind to socket: $@";

        print "DHCP listen on ",$sock->sockhost,":",$sock->sockport,"\n";

        while (1) {
                process_packet $sock;
        }
}

warn "loaded";

1;
1	dpavlin	48	package dhcpd;
2	dpavlin	1
3	dpavlin	44	=head1 dhcpd
4	dpavlin	1
5	dpavlin	44	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	dpavlin	1	use strict;
14			use warnings;
15
16	dpavlin	22	use autodie;
17
18	dpavlin	1	use IO::Socket::INET;
19	dpavlin	17	use File::Slurp;
20	dpavlin	1	use Data::Dump qw/dump/;
21
22	dpavlin	44	use lib '..';
23	dpavlin	27	use Net::DHCP::Packet;
24			use Net::DHCP::Constants 0.67;
25	dpavlin	1
26	dpavlin	44	use server;
27	dpavlin	67	my $debug = server::debug;
28	dpavlin	1
29	dpavlin	44	if ( ! $server::ip ) {
30			my $server_ip = `/sbin/ifconfig`;
31	dpavlin	22	$server_ip =~ s/^.+?addr:([\d\.]+).*$/$1/gs;
32	dpavlin	44	$server::ip = $server_ip;
33	dpavlin	22	}
34
35	dpavlin	110	warn "server ip $server::ip range: $server::ip_from - $server::ip_to\n";
36	dpavlin	1
37	dpavlin	168	use client;
38	dpavlin	17
39	dpavlin	1	sub client_ip {
40			my ( $mac ) = @_;
41
42	dpavlin	156	my $conf = $server::conf;
43	dpavlin	17	mkdir $conf unless -e $conf;
44	dpavlin	1
45	dpavlin	177	my $ip;
46
47	dpavlin	194	if ( $ip = client::ip_from_mac( $mac ) ) {
48	dpavlin	94	print "RENEW $mac $ip\n";
49	dpavlin	17	return $ip;
50	dpavlin	177	} else {
51	dpavlin	200	$ip = client::next_ip( $mac );
52	dpavlin	177	print "NEW $mac $ip\n";
53	dpavlin	17	}
54	dpavlin	1
55			return $ip;
56			}
57
58	dpavlin	110	use log;
59			use config;
60	dpavlin	129	use pxelinux;
61	dpavlin	160	use client;
62	dpavlin	110
63			our $file;
64	dpavlin	44	our $transaction = 0; # FIXME predictible transaction numbers
65	dpavlin	27
66	dpavlin	44	sub process_packet {
67			my $sock = shift;
68	dpavlin	1
69	dpavlin	128	server->refresh;
70
71	dpavlin	1	my $buf;
72			$sock->recv($buf, 1024);
73	dpavlin	44	my $size = 'empty';
74			$size = length($buf) . ' bytes' if defined $buf;
75	dpavlin	1
76	dpavlin	94	print "packet from ",$sock->peerhost,":",$sock->peerport," $size\n" if $debug;
77	dpavlin	44	return unless $buf;
78	dpavlin	1
79	dpavlin	44	my $dhcp = Net::DHCP::Packet->new($buf);
80			$dhcp->comment( $transaction++ );
81	dpavlin	1
82	dpavlin	67	warn "recv: ", $dhcp->toString if $debug;
83	dpavlin	1
84	dpavlin	44	my $mac = substr($dhcp->chaddr(),0,$dhcp->hlen()*2);
85			my $ip = client_ip($mac);
86	dpavlin	1
87	dpavlin	44	=for later
88	dpavlin	6
89	dpavlin	44	my $user_class = $dhcp->getOptionValue(DHO_USER_CLASS());
90	dpavlin	1
91	dpavlin	44	if ( $user_class eq 'gPXE' ) {
92			$file = $gpxe_file;
93			} elsif ( ! $file ) {
94			$file = 'undionly.kpxe';
95			}
96	dpavlin	22
97	dpavlin	44	=cut
98
99	dpavlin	110	config::for_ip( $ip );
100
101	dpavlin	44	my $packet = {
102			Op => BOOTREPLY(),
103			Hops => $dhcp->hops(),
104			Xid => $dhcp->xid(),
105			Flags => $dhcp->flags(),
106			Ciaddr => $dhcp->ciaddr(),
107			Yiaddr => $ip,
108			Siaddr => $server::ip,
109			Giaddr => $dhcp->giaddr(),
110			Chaddr => $dhcp->chaddr(),
111	dpavlin	110	File => $file,
112	dpavlin	160	DHO_DHCP_SERVER_IDENTIFIER() => $server::ip, # busybox/udhcpc needs it but doesn't request
113	dpavlin	44	};
114
115	dpavlin	160	my $options = {
116			DHO_SUBNET_MASK() => $server::netmask,
117			DHO_ROUTERS() => $server::ip,
118			DHO_DOMAIN_NAME() => $server::domain_name,
119			DHO_NAME_SERVERS() => $server::ip,
120			DHO_DOMAIN_NAME_SERVERS() => $server::ip,
121			DHO_HOST_NAME() => client::conf( $ip, 'hostname' ),
122			DHO_BROADCAST_ADDRESS() => $server::bcast,
123			# DHO_NTP_SERVERS() => '',
124			};
125
126			my @requested = split(/\s/, $dhcp->getOptionValue(DHO_DHCP_PARAMETER_REQUEST_LIST));
127	dpavlin	167	warn "options ",dump( $options ), ' requested: ',dump( @requested ) if $debug;
128
129			my @missing;
130	dpavlin	160	foreach ( @requested ) {
131	dpavlin	167	if ( defined $options->{$_} ) {
132			$packet->{$_} = $options->{$_};
133			} else {
134			push @missing, $_;
135			}
136	dpavlin	160	}
137
138	dpavlin	168	warn "W: options requested but missing: ",dump( @missing ),$/;
139	dpavlin	167
140	dpavlin	129	foreach my $opt ( 'magic', 'config_file', 'path_prefix', 'reboot_time' ) {
141			my $DH0 = eval 'DHO_PXELINUX_' . uc $opt;
142			warn "DH0: $@" if $@;
143			my $v = eval "\$pxelinux::$opt";
144			warn "v: $@" if $@;
145			next unless defined $v;
146	dpavlin	167	warn "pxelinux dhcp option $opt = $DH0 = $v\n" if $debug;
147	dpavlin	129	$packet->{ $DH0 } = $v;
148			}
149
150	dpavlin	44	my $messagetype = $dhcp->getOptionValue(DHO_DHCP_MESSAGE_TYPE());
151
152			if ($messagetype eq DHCPDISCOVER()) {
153	dpavlin	72	log::mac $mac, "DHCP DISCOVER";
154	dpavlin	44	$packet->{Comment} = $dhcp->comment();
155			$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPOFFER();
156			} elsif ($messagetype eq DHCPREQUEST()) {
157			my $requested_ip = $dhcp->getOptionValue(DHO_DHCP_REQUESTED_ADDRESS());
158	dpavlin	110	log::mac $mac, "DHCP REQUEST $requested_ip $ip $file";
159	dpavlin	44	if ( $ip eq $requested_ip ) {
160			$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPACK();
161			$packet->{DHO_DHCP_LEASE_TIME()} = 5 * 60; # 5 min
162			# $packet->{DHO_ROOT_PATH()} = '/exports/foobar';
163	dpavlin	27	} else {
164	dpavlin	44	$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPNAK();
165			$packet->{DHO_DHCP_MESSAGE()} = "Bad request, expected $ip";
166	dpavlin	27	}
167	dpavlin	44	} elsif ($messagetype eq DHCPINFORM()) {
168	dpavlin	72	log::mac $mac, "DHCP INFORM ignored";
169	dpavlin	44	} else {
170	dpavlin	72	log::mac $mac, "$messagetype igored (bootp?)";
171	dpavlin	44	}
172	dpavlin	27
173	dpavlin	110	warn ">> $mac == $ip server: $server::ip", $file ? " file: $file\n" : "\n" if $debug;
174	dpavlin	27
175	dpavlin	44	$packet = new Net::DHCP::Packet( %$packet );
176	dpavlin	67	warn "send ",$packet->toString() if $debug;
177	dpavlin	27
178	dpavlin	44	my $reply = IO::Socket::INET->new(
179			LocalAddr => $server::ip,
180			LocalPort => 67,
181			Proto => "udp",
182			Broadcast => 1,
183			PeerAddr => '255.255.255.255',
184			PeerPort => 68,
185			Reuse => 1,
186			) or die "socket: $@";
187	dpavlin	1
188	dpavlin	44	my $buff = $packet->serialize();
189			$reply->send( $buff, 0 ) or die "Error sending: $!\n";
190	dpavlin	1
191	dpavlin	44	# system("arp -s $ip $mac"),
192	dpavlin	1
193	dpavlin	44	}
194	dpavlin	1
195	dpavlin	44	sub start {
196
197			my $sock = IO::Socket::INET->new(
198			LocalPort => 67,
199			# LocalAddr => 'localhost',
200			# LocalAddr => '10.0.0.100',
201			LocalAddr => '0.0.0.0',
202			Proto => 'udp',
203			ReuseAddr => 1,
204			# PeerPort => getservbyname('bootpc', 'udp'),
205			Broadcast => 1,
206			Type => SOCK_DGRAM,
207			) or die "Failed to bind to socket: $@";
208
209			print "DHCP listen on ",$sock->sockhost,":",$sock->sockport,"\n";
210
211			while (1) {
212			process_packet $sock;
213	dpavlin	1	}
214	dpavlin	44	}
215	dpavlin	1
216	dpavlin	45	warn "loaded";
217
218	dpavlin	44	1;