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 ) = @_;

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

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

        my $mac = substr($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";

        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;

        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	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	244	} elsif ( in_our_range( $request_ip ) ) {
54	dpavlin	200	$ip = client::next_ip( $mac );
55	dpavlin	177	print "NEW $mac $ip\n";
56	dpavlin	244	} else {
57			$ip = $request_ip;
58			client::save_ip_mac( $ip, $mac );
59			warn "W: $ip our of server range $server::ip $server::netmask\n";
60	dpavlin	17	}
61	dpavlin	1
62			return $ip;
63			}
64
65	dpavlin	110	use log;
66			use config;
67	dpavlin	129	use pxelinux;
68	dpavlin	160	use client;
69	dpavlin	110
70			our $file;
71	dpavlin	44	our $transaction = 0; # FIXME predictible transaction numbers
72	dpavlin	27
73	dpavlin	244	sub ip2bin { pack('C*', split(/\./, $_[0])) };
74			sub in_our_range {
75			my $ip = shift;
76			return 1 if $ip eq '0.0.0.0';
77			return 1 if (
78			( ip2bin($ip) & ip2bin($server::netmask) )
79			eq
80			( ip2bin($server::ip) & ip2bin($server::netmask) )
81			);
82			}
83
84	dpavlin	44	sub process_packet {
85			my $sock = shift;
86	dpavlin	1
87	dpavlin	128	server->refresh;
88
89	dpavlin	1	my $buf;
90			$sock->recv($buf, 1024);
91	dpavlin	44	my $size = 'empty';
92			$size = length($buf) . ' bytes' if defined $buf;
93	dpavlin	1
94	dpavlin	94	print "packet from ",$sock->peerhost,":",$sock->peerport," $size\n" if $debug;
95	dpavlin	44	return unless $buf;
96	dpavlin	1
97	dpavlin	44	my $dhcp = Net::DHCP::Packet->new($buf);
98			$dhcp->comment( $transaction++ );
99	dpavlin	1
100	dpavlin	67	warn "recv: ", $dhcp->toString if $debug;
101	dpavlin	1
102	dpavlin	44	my $mac = substr($dhcp->chaddr(),0,$dhcp->hlen()*2);
103	dpavlin	244	my $ip = client_mac_ip($mac, $dhcp->ciaddr);
104	dpavlin	1
105	dpavlin	201	my $hostname = $dhcp->getOptionValue(DHO_HOST_NAME);
106			print "$ip ", client::conf( $ip => 'hostname', default => $hostname ), " >> /etc/hosts\n";
107
108	dpavlin	208	my $audit = { mac => format::mac($mac), ip => $ip, hostname => $hostname };
109	dpavlin	207
110	dpavlin	44	=for later
111	dpavlin	6
112	dpavlin	44	my $user_class = $dhcp->getOptionValue(DHO_USER_CLASS());
113	dpavlin	1
114	dpavlin	44	if ( $user_class eq 'gPXE' ) {
115			$file = $gpxe_file;
116			} elsif ( ! $file ) {
117			$file = 'undionly.kpxe';
118			}
119	dpavlin	22
120	dpavlin	44	=cut
121
122	dpavlin	110	config::for_ip( $ip );
123
124	dpavlin	44	my $packet = {
125			Op => BOOTREPLY(),
126			Hops => $dhcp->hops(),
127			Xid => $dhcp->xid(),
128			Flags => $dhcp->flags(),
129			Ciaddr => $dhcp->ciaddr(),
130			Yiaddr => $ip,
131			Siaddr => $server::ip,
132			Giaddr => $dhcp->giaddr(),
133			Chaddr => $dhcp->chaddr(),
134	dpavlin	110	File => $file,
135	dpavlin	160	DHO_DHCP_SERVER_IDENTIFIER() => $server::ip, # busybox/udhcpc needs it but doesn't request
136	dpavlin	44	};
137
138	dpavlin	160	my $options = {
139			DHO_SUBNET_MASK() => $server::netmask,
140			DHO_ROUTERS() => $server::ip,
141			DHO_DOMAIN_NAME() => $server::domain_name,
142			DHO_NAME_SERVERS() => $server::ip,
143			DHO_DOMAIN_NAME_SERVERS() => $server::ip,
144			DHO_HOST_NAME() => client::conf( $ip, 'hostname' ),
145			DHO_BROADCAST_ADDRESS() => $server::bcast,
146			# DHO_NTP_SERVERS() => '',
147			};
148
149			my @requested = split(/\s/, $dhcp->getOptionValue(DHO_DHCP_PARAMETER_REQUEST_LIST));
150	dpavlin	167	warn "options ",dump( $options ), ' requested: ',dump( @requested ) if $debug;
151
152			my @missing;
153	dpavlin	160	foreach ( @requested ) {
154	dpavlin	167	if ( defined $options->{$_} ) {
155			$packet->{$_} = $options->{$_};
156			} else {
157			push @missing, $_;
158			}
159	dpavlin	160	}
160
161	dpavlin	168	warn "W: options requested but missing: ",dump( @missing ),$/;
162	dpavlin	207	$audit->{requested} = [ @requested ];
163			$audit->{missing} = [ @missing ];
164	dpavlin	167
165	dpavlin	129	foreach my $opt ( 'magic', 'config_file', 'path_prefix', 'reboot_time' ) {
166			my $DH0 = eval 'DHO_PXELINUX_' . uc $opt;
167			warn "DH0: $@" if $@;
168			my $v = eval "\$pxelinux::$opt";
169			warn "v: $@" if $@;
170			next unless defined $v;
171	dpavlin	167	warn "pxelinux dhcp option $opt = $DH0 = $v\n" if $debug;
172	dpavlin	129	$packet->{ $DH0 } = $v;
173			}
174
175	dpavlin	44	my $messagetype = $dhcp->getOptionValue(DHO_DHCP_MESSAGE_TYPE());
176
177			if ($messagetype eq DHCPDISCOVER()) {
178	dpavlin	207	$audit->{type} = 'discover';
179	dpavlin	44	$packet->{Comment} = $dhcp->comment();
180			$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPOFFER();
181			} elsif ($messagetype eq DHCPREQUEST()) {
182			my $requested_ip = $dhcp->getOptionValue(DHO_DHCP_REQUESTED_ADDRESS());
183	dpavlin	207	$audit->{type} = 'request';
184	dpavlin	44	if ( $ip eq $requested_ip ) {
185			$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPACK();
186			$packet->{DHO_DHCP_LEASE_TIME()} = 5 * 60; # 5 min
187			# $packet->{DHO_ROOT_PATH()} = '/exports/foobar';
188	dpavlin	27	} else {
189	dpavlin	44	$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPNAK();
190			$packet->{DHO_DHCP_MESSAGE()} = "Bad request, expected $ip";
191	dpavlin	27	}
192	dpavlin	44	} elsif ($messagetype eq DHCPINFORM()) {
193	dpavlin	207	$audit->{type} = 'inform';
194	dpavlin	44	} else {
195	dpavlin	207	$audit->{type} = sprintf('ignored %x', $messagetype);
196	dpavlin	44	}
197	dpavlin	27
198	dpavlin	110	warn ">> $mac == $ip server: $server::ip", $file ? " file: $file\n" : "\n" if $debug;
199	dpavlin	207	$audit->{response} = $packet;
200	dpavlin	27
201	dpavlin	44	$packet = new Net::DHCP::Packet( %$packet );
202	dpavlin	67	warn "send ",$packet->toString() if $debug;
203	dpavlin	27
204	dpavlin	244	if ( in_our_range( $ip ) ) {
205			my $buff = $packet->serialize();
206	dpavlin	207
207	dpavlin	244	my $reply = IO::Socket::INET->new(
208			LocalAddr => $server::ip,
209			LocalPort => 67,
210			Proto => "udp",
211			Broadcast => 1,
212			PeerAddr => '255.255.255.255',
213			PeerPort => 68,
214			Reuse => 1,
215			) or die "socket: $@";
216	dpavlin	1
217	dpavlin	244	$reply->send( $buff, 0 ) or die "Error sending: $!\n";
218			} else {
219			$audit->{error} = "$ip our of our range $server::ip $server::netmask";
220			}
221	dpavlin	1
222	dpavlin	244	CouchDB::audit( $audit->{type}, $audit );
223
224	dpavlin	44	# system("arp -s $ip $mac"),
225	dpavlin	1
226	dpavlin	44	}
227	dpavlin	1
228	dpavlin	44	sub start {
229
230			my $sock = IO::Socket::INET->new(
231			LocalPort => 67,
232			# LocalAddr => 'localhost',
233			# LocalAddr => '10.0.0.100',
234			LocalAddr => '0.0.0.0',
235			Proto => 'udp',
236			ReuseAddr => 1,
237			# PeerPort => getservbyname('bootpc', 'udp'),
238			Broadcast => 1,
239			Type => SOCK_DGRAM,
240			) or die "Failed to bind to socket: $@";
241
242			print "DHCP listen on ",$sock->sockhost,":",$sock->sockport,"\n";
243
244	dpavlin	232	CouchDB::audit( 'start', { addr => $sock->sockhost, port => $sock->sockport } );
245	dpavlin	207
246	dpavlin	44	while (1) {
247			process_packet $sock;
248	dpavlin	1	}
249	dpavlin	44	}
250	dpavlin	1
251	dpavlin	45	warn "loaded";
252
253	dpavlin	44	1;