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_mac_ip {
        my ( $mac, $request_ip ) = @_;

        if ( ! $mac ) {
                warn "W: no mac in requiest\n";
                return;
        }

        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;
        } elsif ( in_our_range( $request_ip ) ) {
                $ip = client::next_ip( $mac );
                print "NEW $mac $ip\n";
        } else {
                $ip = $request_ip;
                client::save_ip_mac( $ip, $mac );
                warn "W: $ip our of server range $server::ip $server::netmask\n";
        }

        return $ip;
}

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

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

sub ip2bin { pack('C*', split(/\./, $_[0])) };
sub in_our_range {
        my $ip = shift;
        return 1 if $ip eq '0.0.0.0';
        return 1 if (
                ( ip2bin($ip)         & ip2bin($server::netmask) )
                eq
                ( ip2bin($server::ip) & ip2bin($server::netmask) )
        );
}

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);

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

        $dhcp->comment( $transaction++ );

        my $mac = format::mac( substr($dhcp->chaddr(),0,$dhcp->hlen()*2) );
        my $ip = client_mac_ip($mac, $dhcp->ciaddr);

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

        my $audit = { mac => $mac, ip => $ip, hostname => $hostname,
                options => {
                        map {
                                ( $_ => $dhcp->getOptionValue( $_ ) )
                        } @{ $dhcp->{options_order} }
                },
        };

=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;

        if ( in_our_range( $ip ) ) {
                my $buff = $packet->serialize();

                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: $@";

                $reply->send( $buff, 0 ) or die "Error sending: $!\n";
        } else {
                $audit->{error} = "$ip our of our range $server::ip $server::netmask";
        }

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

#       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	244	sub client_mac_ip {
43			my ( $mac, $request_ip ) = @_;
44	dpavlin	1
45	dpavlin	267	if ( ! $mac ) {
46			warn "W: no mac in requiest\n";
47			return;
48			}
49
50	dpavlin	156	my $conf = $server::conf;
51	dpavlin	17	mkdir $conf unless -e $conf;
52	dpavlin	1
53	dpavlin	177	my $ip;
54
55	dpavlin	194	if ( $ip = client::ip_from_mac( $mac ) ) {
56	dpavlin	94	print "RENEW $mac $ip\n";
57	dpavlin	17	return $ip;
58	dpavlin	244	} elsif ( in_our_range( $request_ip ) ) {
59	dpavlin	200	$ip = client::next_ip( $mac );
60	dpavlin	177	print "NEW $mac $ip\n";
61	dpavlin	244	} else {
62			$ip = $request_ip;
63			client::save_ip_mac( $ip, $mac );
64			warn "W: $ip our of server range $server::ip $server::netmask\n";
65	dpavlin	17	}
66	dpavlin	1
67			return $ip;
68			}
69
70	dpavlin	110	use log;
71			use config;
72	dpavlin	129	use pxelinux;
73	dpavlin	160	use client;
74	dpavlin	110
75			our $file;
76	dpavlin	44	our $transaction = 0; # FIXME predictible transaction numbers
77	dpavlin	27
78	dpavlin	244	sub ip2bin { pack('C*', split(/\./, $_[0])) };
79			sub in_our_range {
80			my $ip = shift;
81			return 1 if $ip eq '0.0.0.0';
82			return 1 if (
83			( ip2bin($ip) & ip2bin($server::netmask) )
84			eq
85			( ip2bin($server::ip) & ip2bin($server::netmask) )
86			);
87			}
88
89	dpavlin	44	sub process_packet {
90			my $sock = shift;
91	dpavlin	1
92	dpavlin	128	server->refresh;
93
94	dpavlin	1	my $buf;
95			$sock->recv($buf, 1024);
96	dpavlin	44	my $size = 'empty';
97			$size = length($buf) . ' bytes' if defined $buf;
98	dpavlin	1
99	dpavlin	94	print "packet from ",$sock->peerhost,":",$sock->peerport," $size\n" if $debug;
100	dpavlin	44	return unless $buf;
101	dpavlin	1
102	dpavlin	44	my $dhcp = Net::DHCP::Packet->new($buf);
103	dpavlin	1
104	dpavlin	67	warn "recv: ", $dhcp->toString if $debug;
105	dpavlin	1
106	dpavlin	260	$dhcp->comment( $transaction++ );
107
108	dpavlin	313	my $mac = format::mac( substr($dhcp->chaddr(),0,$dhcp->hlen()*2) );
109	dpavlin	244	my $ip = client_mac_ip($mac, $dhcp->ciaddr);
110	dpavlin	1
111	dpavlin	201	my $hostname = $dhcp->getOptionValue(DHO_HOST_NAME);
112	dpavlin	313	print "$ip ", client::conf( $ip => 'hostname', default => $hostname ), " >> /etc/hosts\n" if $hostname;
113	dpavlin	201
114	dpavlin	313	my $audit = { mac => $mac, ip => $ip, hostname => $hostname,
115	dpavlin	260	options => {
116			map {
117			( $_ => $dhcp->getOptionValue( $_ ) )
118			} @{ $dhcp->{options_order} }
119			},
120			};
121	dpavlin	207
122	dpavlin	44	=for later
123	dpavlin	6
124	dpavlin	44	my $user_class = $dhcp->getOptionValue(DHO_USER_CLASS());
125	dpavlin	1
126	dpavlin	44	if ( $user_class eq 'gPXE' ) {
127			$file = $gpxe_file;
128			} elsif ( ! $file ) {
129			$file = 'undionly.kpxe';
130			}
131	dpavlin	22
132	dpavlin	44	=cut
133
134	dpavlin	110	config::for_ip( $ip );
135
136	dpavlin	44	my $packet = {
137			Op => BOOTREPLY(),
138			Hops => $dhcp->hops(),
139			Xid => $dhcp->xid(),
140			Flags => $dhcp->flags(),
141			Ciaddr => $dhcp->ciaddr(),
142			Yiaddr => $ip,
143			Siaddr => $server::ip,
144			Giaddr => $dhcp->giaddr(),
145			Chaddr => $dhcp->chaddr(),
146	dpavlin	110	File => $file,
147	dpavlin	160	DHO_DHCP_SERVER_IDENTIFIER() => $server::ip, # busybox/udhcpc needs it but doesn't request
148	dpavlin	44	};
149
150	dpavlin	160	my $options = {
151			DHO_SUBNET_MASK() => $server::netmask,
152			DHO_ROUTERS() => $server::ip,
153			DHO_DOMAIN_NAME() => $server::domain_name,
154			DHO_NAME_SERVERS() => $server::ip,
155			DHO_DOMAIN_NAME_SERVERS() => $server::ip,
156			DHO_HOST_NAME() => client::conf( $ip, 'hostname' ),
157			DHO_BROADCAST_ADDRESS() => $server::bcast,
158			# DHO_NTP_SERVERS() => '',
159			};
160
161			my @requested = split(/\s/, $dhcp->getOptionValue(DHO_DHCP_PARAMETER_REQUEST_LIST));
162	dpavlin	167	warn "options ",dump( $options ), ' requested: ',dump( @requested ) if $debug;
163
164			my @missing;
165	dpavlin	160	foreach ( @requested ) {
166	dpavlin	167	if ( defined $options->{$_} ) {
167			$packet->{$_} = $options->{$_};
168			} else {
169			push @missing, $_;
170			}
171	dpavlin	160	}
172
173	dpavlin	168	warn "W: options requested but missing: ",dump( @missing ),$/;
174	dpavlin	207	$audit->{requested} = [ @requested ];
175			$audit->{missing} = [ @missing ];
176	dpavlin	167
177	dpavlin	129	foreach my $opt ( 'magic', 'config_file', 'path_prefix', 'reboot_time' ) {
178			my $DH0 = eval 'DHO_PXELINUX_' . uc $opt;
179			warn "DH0: $@" if $@;
180			my $v = eval "\$pxelinux::$opt";
181			warn "v: $@" if $@;
182			next unless defined $v;
183	dpavlin	167	warn "pxelinux dhcp option $opt = $DH0 = $v\n" if $debug;
184	dpavlin	129	$packet->{ $DH0 } = $v;
185			}
186
187	dpavlin	44	my $messagetype = $dhcp->getOptionValue(DHO_DHCP_MESSAGE_TYPE());
188
189			if ($messagetype eq DHCPDISCOVER()) {
190	dpavlin	207	$audit->{type} = 'discover';
191	dpavlin	44	$packet->{Comment} = $dhcp->comment();
192			$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPOFFER();
193			} elsif ($messagetype eq DHCPREQUEST()) {
194			my $requested_ip = $dhcp->getOptionValue(DHO_DHCP_REQUESTED_ADDRESS());
195	dpavlin	207	$audit->{type} = 'request';
196	dpavlin	44	if ( $ip eq $requested_ip ) {
197			$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPACK();
198			$packet->{DHO_DHCP_LEASE_TIME()} = 5 * 60; # 5 min
199			# $packet->{DHO_ROOT_PATH()} = '/exports/foobar';
200	dpavlin	27	} else {
201	dpavlin	44	$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPNAK();
202			$packet->{DHO_DHCP_MESSAGE()} = "Bad request, expected $ip";
203	dpavlin	27	}
204	dpavlin	44	} elsif ($messagetype eq DHCPINFORM()) {
205	dpavlin	207	$audit->{type} = 'inform';
206	dpavlin	44	} else {
207	dpavlin	207	$audit->{type} = sprintf('ignored %x', $messagetype);
208	dpavlin	44	}
209	dpavlin	27
210	dpavlin	110	warn ">> $mac == $ip server: $server::ip", $file ? " file: $file\n" : "\n" if $debug;
211	dpavlin	207	$audit->{response} = $packet;
212	dpavlin	27
213	dpavlin	44	$packet = new Net::DHCP::Packet( %$packet );
214	dpavlin	67	warn "send ",$packet->toString() if $debug;
215	dpavlin	27
216	dpavlin	244	if ( in_our_range( $ip ) ) {
217			my $buff = $packet->serialize();
218	dpavlin	207
219	dpavlin	244	my $reply = IO::Socket::INET->new(
220			LocalAddr => $server::ip,
221			LocalPort => 67,
222			Proto => "udp",
223			Broadcast => 1,
224			PeerAddr => '255.255.255.255',
225			PeerPort => 68,
226			Reuse => 1,
227			) or die "socket: $@";
228	dpavlin	1
229	dpavlin	244	$reply->send( $buff, 0 ) or die "Error sending: $!\n";
230			} else {
231			$audit->{error} = "$ip our of our range $server::ip $server::netmask";
232			}
233	dpavlin	1
234	dpavlin	244	CouchDB::audit( $audit->{type}, $audit );
235
236	dpavlin	44	# system("arp -s $ip $mac"),
237	dpavlin	1
238	dpavlin	44	}
239	dpavlin	1
240	dpavlin	44	sub start {
241
242			my $sock = IO::Socket::INET->new(
243			LocalPort => 67,
244			# LocalAddr => 'localhost',
245			# LocalAddr => '10.0.0.100',
246			LocalAddr => '0.0.0.0',
247			Proto => 'udp',
248			ReuseAddr => 1,
249			# PeerPort => getservbyname('bootpc', 'udp'),
250			Broadcast => 1,
251			Type => SOCK_DGRAM,
252			) or die "Failed to bind to socket: $@";
253
254			print "DHCP listen on ",$sock->sockhost,":",$sock->sockport,"\n";
255
256	dpavlin	232	CouchDB::audit( 'start', { addr => $sock->sockhost, port => $sock->sockport } );
257	dpavlin	207
258	dpavlin	44	while (1) {
259			process_packet $sock;
260	dpavlin	1	}
261	dpavlin	44	}
262	dpavlin	1
263	dpavlin	45	warn "loaded";
264
265	dpavlin	44	1;