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 Module::Refresh;

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::base_dir/conf/$server::ip";
        mkdir $conf unless -e $conf;

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

        mkdir $_ foreach grep { ! -e $_ } map { "$conf/$_" } ( 'ip', 'mac' );

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

        print "$mac NEW $ip\n";

        return $ip;
}

use log;
use config;

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

sub process_packet {
        my $sock = shift;

        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,
        };

        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_DHCP_SERVER_IDENTIFIER()} = $server::ip;          # FIXME
                        $packet->{DHO_SUBNET_MASK()}            = '255.255.255.0';
                        $packet->{DHO_ROUTERS()}                = $server::ip;
#                       $packet->{DHO_DOMAIN_NAME()}            = 'pxelator.lan';
#                       $packet->{DHO_NAME_SERVERS()}           = $server::ip;
#                       $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) {
                Module::Refresh->refresh;
                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	44	use Module::Refresh;
23	dpavlin	1
24	dpavlin	44	use lib '..';
25	dpavlin	27	use Net::DHCP::Packet;
26			use Net::DHCP::Constants 0.67;
27	dpavlin	1
28	dpavlin	44	use server;
29	dpavlin	67	my $debug = server::debug;
30	dpavlin	1
31	dpavlin	44	if ( ! $server::ip ) {
32			my $server_ip = `/sbin/ifconfig`;
33	dpavlin	22	$server_ip =~ s/^.+?addr:([\d\.]+).*$/$1/gs;
34	dpavlin	44	$server::ip = $server_ip;
35	dpavlin	22	}
36
37	dpavlin	110	warn "server ip $server::ip range: $server::ip_from - $server::ip_to\n";
38	dpavlin	1
39	dpavlin	45	my $addr = $server::ip_from;
40	dpavlin	17
41	dpavlin	1	sub client_ip {
42			my ( $mac ) = @_;
43
44	dpavlin	69	my $conf = "$server::base_dir/conf/$server::ip";
45	dpavlin	17	mkdir $conf unless -e $conf;
46	dpavlin	1
47	dpavlin	22	if ( -e "$conf/mac/$mac" ) {
48			my $ip = read_file "$conf/mac/$mac";
49	dpavlin	94	print "RENEW $mac $ip\n";
50	dpavlin	17	return $ip;
51			}
52	dpavlin	1
53	dpavlin	17	mkdir $_ foreach grep { ! -e $_ } map { "$conf/$_" } ( 'ip', 'mac' );
54
55	dpavlin	36	my $p = Net::Ping->new;
56
57	dpavlin	44	my $prefix = $server::ip;
58	dpavlin	17	$prefix =~ s{\.\d+$}{.};
59			my $ip = $prefix . $addr;
60	dpavlin	36	while ( -e "conf/ip/$ip" \|\| $p->ping( $ip ) ) {
61	dpavlin	17	$ip = $prefix . $addr++;
62	dpavlin	45	die "all addresses allocated!" if $addr == $server::ip_to;
63	dpavlin	1	}
64
65	dpavlin	17	write_file "$conf/mac/$mac", $ip;
66	dpavlin	33	if ( -l "$conf/ip/$ip" && readlink "$conf/ip/$ip" ne "$conf/mac/$mac") {
67			unlink "$conf/ip/$ip";
68			symlink "$conf/mac/$mac", "$conf/ip/$ip";
69			warn "$mac IP changed to $ip";
70			}
71	dpavlin	17
72			print "$mac NEW $ip\n";
73
74	dpavlin	1	return $ip;
75			}
76
77	dpavlin	110	use log;
78			use config;
79
80			our $file;
81	dpavlin	44	our $transaction = 0; # FIXME predictible transaction numbers
82	dpavlin	27
83	dpavlin	44	sub process_packet {
84			my $sock = shift;
85	dpavlin	1
86			my $buf;
87			$sock->recv($buf, 1024);
88	dpavlin	44	my $size = 'empty';
89			$size = length($buf) . ' bytes' if defined $buf;
90	dpavlin	1
91	dpavlin	94	print "packet from ",$sock->peerhost,":",$sock->peerport," $size\n" if $debug;
92	dpavlin	44	return unless $buf;
93	dpavlin	1
94	dpavlin	44	my $dhcp = Net::DHCP::Packet->new($buf);
95			$dhcp->comment( $transaction++ );
96	dpavlin	1
97	dpavlin	67	warn "recv: ", $dhcp->toString if $debug;
98	dpavlin	1
99	dpavlin	44	my $mac = substr($dhcp->chaddr(),0,$dhcp->hlen()*2);
100			my $ip = client_ip($mac);
101	dpavlin	1
102	dpavlin	44	=for later
103	dpavlin	6
104	dpavlin	44	my $user_class = $dhcp->getOptionValue(DHO_USER_CLASS());
105	dpavlin	1
106	dpavlin	44	if ( $user_class eq 'gPXE' ) {
107			$file = $gpxe_file;
108			} elsif ( ! $file ) {
109			$file = 'undionly.kpxe';
110			}
111	dpavlin	22
112	dpavlin	44	=cut
113
114	dpavlin	110	config::for_ip( $ip );
115
116	dpavlin	44	my $packet = {
117			Op => BOOTREPLY(),
118			Hops => $dhcp->hops(),
119			Xid => $dhcp->xid(),
120			Flags => $dhcp->flags(),
121			Ciaddr => $dhcp->ciaddr(),
122			Yiaddr => $ip,
123			Siaddr => $server::ip,
124			Giaddr => $dhcp->giaddr(),
125			Chaddr => $dhcp->chaddr(),
126	dpavlin	110	File => $file,
127	dpavlin	44	};
128
129			my $messagetype = $dhcp->getOptionValue(DHO_DHCP_MESSAGE_TYPE());
130
131			if ($messagetype eq DHCPDISCOVER()) {
132	dpavlin	72	log::mac $mac, "DHCP DISCOVER";
133	dpavlin	44	$packet->{Comment} = $dhcp->comment();
134			$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPOFFER();
135			} elsif ($messagetype eq DHCPREQUEST()) {
136			my $requested_ip = $dhcp->getOptionValue(DHO_DHCP_REQUESTED_ADDRESS());
137	dpavlin	110	log::mac $mac, "DHCP REQUEST $requested_ip $ip $file";
138	dpavlin	44	if ( $ip eq $requested_ip ) {
139			$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPACK();
140			$packet->{DHO_DHCP_LEASE_TIME()} = 5 * 60; # 5 min
141			# $packet->{DHO_DHCP_SERVER_IDENTIFIER()} = $server::ip; # FIXME
142			$packet->{DHO_SUBNET_MASK()} = '255.255.255.0';
143			$packet->{DHO_ROUTERS()} = $server::ip;
144			# $packet->{DHO_DOMAIN_NAME()} = 'pxelator.lan';
145			# $packet->{DHO_NAME_SERVERS()} = $server::ip;
146			# $packet->{DHO_ROOT_PATH()} = '/exports/foobar';
147	dpavlin	27	} else {
148	dpavlin	44	$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPNAK();
149			$packet->{DHO_DHCP_MESSAGE()} = "Bad request, expected $ip";
150	dpavlin	27	}
151	dpavlin	44	} elsif ($messagetype eq DHCPINFORM()) {
152	dpavlin	72	log::mac $mac, "DHCP INFORM ignored";
153	dpavlin	44	} else {
154	dpavlin	72	log::mac $mac, "$messagetype igored (bootp?)";
155	dpavlin	44	}
156	dpavlin	27
157	dpavlin	110	warn ">> $mac == $ip server: $server::ip", $file ? " file: $file\n" : "\n" if $debug;
158	dpavlin	27
159	dpavlin	44	$packet = new Net::DHCP::Packet( %$packet );
160	dpavlin	67	warn "send ",$packet->toString() if $debug;
161	dpavlin	27
162	dpavlin	44	my $reply = IO::Socket::INET->new(
163			LocalAddr => $server::ip,
164			LocalPort => 67,
165			Proto => "udp",
166			Broadcast => 1,
167			PeerAddr => '255.255.255.255',
168			PeerPort => 68,
169			Reuse => 1,
170			) or die "socket: $@";
171	dpavlin	1
172	dpavlin	44	my $buff = $packet->serialize();
173			$reply->send( $buff, 0 ) or die "Error sending: $!\n";
174	dpavlin	1
175	dpavlin	44	# system("arp -s $ip $mac"),
176	dpavlin	1
177	dpavlin	44	}
178	dpavlin	1
179	dpavlin	44	sub start {
180
181			my $sock = IO::Socket::INET->new(
182			LocalPort => 67,
183			# LocalAddr => 'localhost',
184			# LocalAddr => '10.0.0.100',
185			LocalAddr => '0.0.0.0',
186			Proto => 'udp',
187			ReuseAddr => 1,
188			# PeerPort => getservbyname('bootpc', 'udp'),
189			Broadcast => 1,
190			Type => SOCK_DGRAM,
191			) or die "Failed to bind to socket: $@";
192
193			print "DHCP listen on ",$sock->sockhost,":",$sock->sockport,"\n";
194
195			while (1) {
196			Module::Refresh->refresh;
197			process_packet $sock;
198	dpavlin	1	}
199	dpavlin	44	}
200	dpavlin	1
201	dpavlin	45	warn "loaded";
202
203	dpavlin	44	1;