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 Net::Ping;

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";

my $addr = $server::ip_from;

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

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

        if ( -e "$conf/mac/$mac" ) {
                my $ip = read_file "$conf/mac/$mac";
                print "RENEW $mac $ip\n";
                return $ip;
        }

        my $p = Net::Ping->new;

        my $prefix = $server::ip;
        $prefix =~ s{\.\d+$}{.};
        my $ip = $prefix . $addr;

        while ( -e "$conf/ip/$ip" || $p->ping( $ip ) ) {
                $ip = $prefix . $addr++;
                die "all addresses allocated!" if $addr == $server::ip_to;
        }

        write_file "$conf/mac/$mac", $ip;

        my $ip_path = "$conf/ip/$ip";
        mkdir $ip_path unless -e $ip_path;

        if ( -l "$ip_path/mac" && readlink "$ip_path/mac" ne "$conf/mac/$mac" ) {
                warn "$mac IP changed from ", readlink "$ip_path/mac", " to $ip";
                unlink "$ip_path/mac";
        };
        symlink "$conf/mac/$mac", "$ip_path/mac";

        print "$mac NEW $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	dpavlin	36	use Net::Ping;
22	dpavlin	1
23	dpavlin	44	use lib '..';
24	dpavlin	27	use Net::DHCP::Packet;
25			use Net::DHCP::Constants 0.67;
26	dpavlin	1
27	dpavlin	44	use server;
28	dpavlin	67	my $debug = server::debug;
29	dpavlin	1
30	dpavlin	44	if ( ! $server::ip ) {
31			my $server_ip = `/sbin/ifconfig`;
32	dpavlin	22	$server_ip =~ s/^.+?addr:([\d\.]+).*$/$1/gs;
33	dpavlin	44	$server::ip = $server_ip;
34	dpavlin	22	}
35
36	dpavlin	110	warn "server ip $server::ip range: $server::ip_from - $server::ip_to\n";
37	dpavlin	1
38	dpavlin	45	my $addr = $server::ip_from;
39	dpavlin	17
40	dpavlin	1	sub client_ip {
41			my ( $mac ) = @_;
42
43	dpavlin	156	my $conf = $server::conf;
44	dpavlin	17	mkdir $conf unless -e $conf;
45	dpavlin	1
46	dpavlin	22	if ( -e "$conf/mac/$mac" ) {
47			my $ip = read_file "$conf/mac/$mac";
48	dpavlin	94	print "RENEW $mac $ip\n";
49	dpavlin	17	return $ip;
50			}
51	dpavlin	1
52	dpavlin	36	my $p = Net::Ping->new;
53
54	dpavlin	44	my $prefix = $server::ip;
55	dpavlin	17	$prefix =~ s{\.\d+$}{.};
56			my $ip = $prefix . $addr;
57	dpavlin	156
58	dpavlin	146	while ( -e "$conf/ip/$ip" \|\| $p->ping( $ip ) ) {
59	dpavlin	17	$ip = $prefix . $addr++;
60	dpavlin	45	die "all addresses allocated!" if $addr == $server::ip_to;
61	dpavlin	1	}
62
63	dpavlin	17	write_file "$conf/mac/$mac", $ip;
64	dpavlin	146
65	dpavlin	156	my $ip_path = "$conf/ip/$ip";
66			mkdir $ip_path unless -e $ip_path;
67
68			if ( -l "$ip_path/mac" && readlink "$ip_path/mac" ne "$conf/mac/$mac" ) {
69			warn "$mac IP changed from ", readlink "$ip_path/mac", " to $ip";
70			unlink "$ip_path/mac";
71	dpavlin	146	};
72	dpavlin	156	symlink "$conf/mac/$mac", "$ip_path/mac";
73	dpavlin	17
74			print "$mac NEW $ip\n";
75
76	dpavlin	1	return $ip;
77			}
78
79	dpavlin	110	use log;
80			use config;
81	dpavlin	129	use pxelinux;
82	dpavlin	160	use client;
83	dpavlin	110
84			our $file;
85	dpavlin	44	our $transaction = 0; # FIXME predictible transaction numbers
86	dpavlin	27
87	dpavlin	44	sub process_packet {
88			my $sock = shift;
89	dpavlin	1
90	dpavlin	128	server->refresh;
91
92	dpavlin	1	my $buf;
93			$sock->recv($buf, 1024);
94	dpavlin	44	my $size = 'empty';
95			$size = length($buf) . ' bytes' if defined $buf;
96	dpavlin	1
97	dpavlin	94	print "packet from ",$sock->peerhost,":",$sock->peerport," $size\n" if $debug;
98	dpavlin	44	return unless $buf;
99	dpavlin	1
100	dpavlin	44	my $dhcp = Net::DHCP::Packet->new($buf);
101			$dhcp->comment( $transaction++ );
102	dpavlin	1
103	dpavlin	67	warn "recv: ", $dhcp->toString if $debug;
104	dpavlin	1
105	dpavlin	44	my $mac = substr($dhcp->chaddr(),0,$dhcp->hlen()*2);
106			my $ip = client_ip($mac);
107	dpavlin	1
108	dpavlin	44	=for later
109	dpavlin	6
110	dpavlin	44	my $user_class = $dhcp->getOptionValue(DHO_USER_CLASS());
111	dpavlin	1
112	dpavlin	44	if ( $user_class eq 'gPXE' ) {
113			$file = $gpxe_file;
114			} elsif ( ! $file ) {
115			$file = 'undionly.kpxe';
116			}
117	dpavlin	22
118	dpavlin	44	=cut
119
120	dpavlin	110	config::for_ip( $ip );
121
122	dpavlin	44	my $packet = {
123			Op => BOOTREPLY(),
124			Hops => $dhcp->hops(),
125			Xid => $dhcp->xid(),
126			Flags => $dhcp->flags(),
127			Ciaddr => $dhcp->ciaddr(),
128			Yiaddr => $ip,
129			Siaddr => $server::ip,
130			Giaddr => $dhcp->giaddr(),
131			Chaddr => $dhcp->chaddr(),
132	dpavlin	110	File => $file,
133	dpavlin	160	DHO_DHCP_SERVER_IDENTIFIER() => $server::ip, # busybox/udhcpc needs it but doesn't request
134	dpavlin	44	};
135
136	dpavlin	160	my $options = {
137			DHO_SUBNET_MASK() => $server::netmask,
138			DHO_ROUTERS() => $server::ip,
139			DHO_DOMAIN_NAME() => $server::domain_name,
140			DHO_NAME_SERVERS() => $server::ip,
141			DHO_DOMAIN_NAME_SERVERS() => $server::ip,
142			DHO_HOST_NAME() => client::conf( $ip, 'hostname' ),
143			DHO_BROADCAST_ADDRESS() => $server::bcast,
144			# DHO_NTP_SERVERS() => '',
145			};
146
147			my @requested = split(/\s/, $dhcp->getOptionValue(DHO_DHCP_PARAMETER_REQUEST_LIST));
148	dpavlin	167	warn "options ",dump( $options ), ' requested: ',dump( @requested ) if $debug;
149
150			my @missing;
151	dpavlin	160	foreach ( @requested ) {
152	dpavlin	167	if ( defined $options->{$_} ) {
153			$packet->{$_} = $options->{$_};
154			} else {
155			push @missing, $_;
156			}
157	dpavlin	160	}
158
159	dpavlin	167	warn "W: options requested but missing: ",dump( @missing );
160
161	dpavlin	129	foreach my $opt ( 'magic', 'config_file', 'path_prefix', 'reboot_time' ) {
162			my $DH0 = eval 'DHO_PXELINUX_' . uc $opt;
163			warn "DH0: $@" if $@;
164			my $v = eval "\$pxelinux::$opt";
165			warn "v: $@" if $@;
166			next unless defined $v;
167	dpavlin	167	warn "pxelinux dhcp option $opt = $DH0 = $v\n" if $debug;
168	dpavlin	129	$packet->{ $DH0 } = $v;
169			}
170
171	dpavlin	44	my $messagetype = $dhcp->getOptionValue(DHO_DHCP_MESSAGE_TYPE());
172
173			if ($messagetype eq DHCPDISCOVER()) {
174	dpavlin	72	log::mac $mac, "DHCP DISCOVER";
175	dpavlin	44	$packet->{Comment} = $dhcp->comment();
176			$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPOFFER();
177			} elsif ($messagetype eq DHCPREQUEST()) {
178			my $requested_ip = $dhcp->getOptionValue(DHO_DHCP_REQUESTED_ADDRESS());
179	dpavlin	110	log::mac $mac, "DHCP REQUEST $requested_ip $ip $file";
180	dpavlin	44	if ( $ip eq $requested_ip ) {
181			$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPACK();
182			$packet->{DHO_DHCP_LEASE_TIME()} = 5 * 60; # 5 min
183			# $packet->{DHO_ROOT_PATH()} = '/exports/foobar';
184	dpavlin	27	} else {
185	dpavlin	44	$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPNAK();
186			$packet->{DHO_DHCP_MESSAGE()} = "Bad request, expected $ip";
187	dpavlin	27	}
188	dpavlin	44	} elsif ($messagetype eq DHCPINFORM()) {
189	dpavlin	72	log::mac $mac, "DHCP INFORM ignored";
190	dpavlin	44	} else {
191	dpavlin	72	log::mac $mac, "$messagetype igored (bootp?)";
192	dpavlin	44	}
193	dpavlin	27
194	dpavlin	110	warn ">> $mac == $ip server: $server::ip", $file ? " file: $file\n" : "\n" if $debug;
195	dpavlin	27
196	dpavlin	44	$packet = new Net::DHCP::Packet( %$packet );
197	dpavlin	67	warn "send ",$packet->toString() if $debug;
198	dpavlin	27
199	dpavlin	44	my $reply = IO::Socket::INET->new(
200			LocalAddr => $server::ip,
201			LocalPort => 67,
202			Proto => "udp",
203			Broadcast => 1,
204			PeerAddr => '255.255.255.255',
205			PeerPort => 68,
206			Reuse => 1,
207			) or die "socket: $@";
208	dpavlin	1
209	dpavlin	44	my $buff = $packet->serialize();
210			$reply->send( $buff, 0 ) or die "Error sending: $!\n";
211	dpavlin	1
212	dpavlin	44	# system("arp -s $ip $mac"),
213	dpavlin	1
214	dpavlin	44	}
215	dpavlin	1
216	dpavlin	44	sub start {
217
218			my $sock = IO::Socket::INET->new(
219			LocalPort => 67,
220			# LocalAddr => 'localhost',
221			# LocalAddr => '10.0.0.100',
222			LocalAddr => '0.0.0.0',
223			Proto => 'udp',
224			ReuseAddr => 1,
225			# PeerPort => getservbyname('bootpc', 'udp'),
226			Broadcast => 1,
227			Type => SOCK_DGRAM,
228			) or die "Failed to bind to socket: $@";
229
230			print "DHCP listen on ",$sock->sockhost,":",$sock->sockport,"\n";
231
232			while (1) {
233			process_packet $sock;
234	dpavlin	1	}
235	dpavlin	44	}
236	dpavlin	1
237	dpavlin	45	warn "loaded";
238
239	dpavlin	44	1;