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 CouchDB;
use format;

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);

        my $hostname = $dhcp->getOptionValue(DHO_HOST_NAME);
        print "$ip ", client::conf( $ip => 'hostname', default => $hostname ), " >> /etc/hosts\n";

        my $audit = { mac => format::mac($mac), ip => $ip, hostname => $hostname };

=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 ),$/;
        $audit->{requested} = [ @requested ];
        $audit->{missing}   = [ @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()) {
                $audit->{type} = 'discover';
                $packet->{Comment} = $dhcp->comment();
                $packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPOFFER();
        } elsif ($messagetype eq DHCPREQUEST()) {
                my $requested_ip = $dhcp->getOptionValue(DHO_DHCP_REQUESTED_ADDRESS());
                $audit->{type} = 'request';
                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()) {
                $audit->{type} = 'inform';
        } else {
                $audit->{type} = sprintf('ignored %x', $messagetype);
        }

        warn ">> $mac == $ip server: $server::ip", $file ? " file: $file\n" : "\n" if $debug;
        $audit->{response} = $packet;

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

        CouchDB::audit( $audit->{type}, $audit );

        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";

        CouchDB::audit( 'start', { addr => $sock->sockhost, port => $sock->sockport } );

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