1 |
package dhcpd; |
2 |
|
3 |
=head1 dhcpd |
4 |
|
5 |
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 |
use strict; |
14 |
use warnings; |
15 |
|
16 |
use autodie; |
17 |
|
18 |
use IO::Socket::INET; |
19 |
use File::Slurp; |
20 |
use Data::Dump qw/dump/; |
21 |
use Net::Ping; |
22 |
use Module::Refresh; |
23 |
|
24 |
use lib '..'; |
25 |
use Net::DHCP::Packet; |
26 |
use Net::DHCP::Constants 0.67; |
27 |
|
28 |
use server; |
29 |
use pxe; |
30 |
|
31 |
my $debug = 1; |
32 |
|
33 |
if ( ! $server::ip ) { |
34 |
my $server_ip = `/sbin/ifconfig`; |
35 |
$server_ip =~ s/^.+?addr:([\d\.]+).*$/$1/gs; |
36 |
$server::ip = $server_ip; |
37 |
} |
38 |
|
39 |
warn "server ip $server::ip file: $pxe::file range: $server::ip_from - $server::ip_to\n"; |
40 |
|
41 |
my $addr = $server::ip_from; |
42 |
|
43 |
sub client_ip { |
44 |
my ( $mac ) = @_; |
45 |
|
46 |
my $conf = "conf/$server::ip"; |
47 |
mkdir $conf unless -e $conf; |
48 |
|
49 |
if ( -e "$conf/mac/$mac" ) { |
50 |
my $ip = read_file "$conf/mac/$mac"; |
51 |
print "$mac old $ip\n"; |
52 |
return $ip; |
53 |
} |
54 |
|
55 |
mkdir $_ foreach grep { ! -e $_ } map { "$conf/$_" } ( 'ip', 'mac' ); |
56 |
|
57 |
my $p = Net::Ping->new; |
58 |
|
59 |
my $prefix = $server::ip; |
60 |
$prefix =~ s{\.\d+$}{.}; |
61 |
my $ip = $prefix . $addr; |
62 |
while ( -e "conf/ip/$ip" || $p->ping( $ip ) ) { |
63 |
$ip = $prefix . $addr++; |
64 |
die "all addresses allocated!" if $addr == $server::ip_to; |
65 |
} |
66 |
|
67 |
write_file "$conf/mac/$mac", $ip; |
68 |
if ( -l "$conf/ip/$ip" && readlink "$conf/ip/$ip" ne "$conf/mac/$mac") { |
69 |
unlink "$conf/ip/$ip"; |
70 |
symlink "$conf/mac/$mac", "$conf/ip/$ip"; |
71 |
warn "$mac IP changed to $ip"; |
72 |
} |
73 |
|
74 |
print "$mac NEW $ip\n"; |
75 |
|
76 |
return $ip; |
77 |
} |
78 |
|
79 |
our $transaction = 0; # FIXME predictible transaction numbers |
80 |
|
81 |
sub process_packet { |
82 |
my $sock = shift; |
83 |
|
84 |
my $buf; |
85 |
$sock->recv($buf, 1024); |
86 |
my $size = 'empty'; |
87 |
$size = length($buf) . ' bytes' if defined $buf; |
88 |
|
89 |
print "packet from ",$sock->peerhost,":",$sock->peerport," $size\n"; |
90 |
return unless $buf; |
91 |
|
92 |
my $dhcp = Net::DHCP::Packet->new($buf); |
93 |
$dhcp->comment( $transaction++ ); |
94 |
|
95 |
warn "recv: ", $dhcp->toString; |
96 |
|
97 |
my $mac = substr($dhcp->chaddr(),0,$dhcp->hlen()*2); |
98 |
my $ip = client_ip($mac); |
99 |
|
100 |
=for later |
101 |
|
102 |
my $user_class = $dhcp->getOptionValue(DHO_USER_CLASS()); |
103 |
|
104 |
if ( $user_class eq 'gPXE' ) { |
105 |
$file = $gpxe_file; |
106 |
} elsif ( ! $file ) { |
107 |
$file = 'undionly.kpxe'; |
108 |
} |
109 |
|
110 |
=cut |
111 |
|
112 |
my $packet = { |
113 |
Op => BOOTREPLY(), |
114 |
Hops => $dhcp->hops(), |
115 |
Xid => $dhcp->xid(), |
116 |
Flags => $dhcp->flags(), |
117 |
Ciaddr => $dhcp->ciaddr(), |
118 |
Yiaddr => $ip, |
119 |
Siaddr => $server::ip, |
120 |
Giaddr => $dhcp->giaddr(), |
121 |
Chaddr => $dhcp->chaddr(), |
122 |
File => $pxe::file, |
123 |
}; |
124 |
|
125 |
my $messagetype = $dhcp->getOptionValue(DHO_DHCP_MESSAGE_TYPE()); |
126 |
|
127 |
if ($messagetype eq DHCPDISCOVER()) { |
128 |
warn "DHCP DISCOVER"; |
129 |
$packet->{Comment} = $dhcp->comment(); |
130 |
$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPOFFER(); |
131 |
} elsif ($messagetype eq DHCPREQUEST()) { |
132 |
my $requested_ip = $dhcp->getOptionValue(DHO_DHCP_REQUESTED_ADDRESS()); |
133 |
warn "DHCP REQUEST $requested_ip"; |
134 |
if ( $ip eq $requested_ip ) { |
135 |
$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPACK(); |
136 |
$packet->{DHO_DHCP_LEASE_TIME()} = 5 * 60; # 5 min |
137 |
# $packet->{DHO_DHCP_SERVER_IDENTIFIER()} = $server::ip; # FIXME |
138 |
$packet->{DHO_SUBNET_MASK()} = '255.255.255.0'; |
139 |
$packet->{DHO_ROUTERS()} = $server::ip; |
140 |
# $packet->{DHO_DOMAIN_NAME()} = 'pxelator.lan'; |
141 |
# $packet->{DHO_NAME_SERVERS()} = $server::ip; |
142 |
# $packet->{DHO_ROOT_PATH()} = '/exports/foobar'; |
143 |
} else { |
144 |
$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPNAK(); |
145 |
$packet->{DHO_DHCP_MESSAGE()} = "Bad request, expected $ip"; |
146 |
} |
147 |
} elsif ($messagetype eq DHCPINFORM()) { |
148 |
warn "DHCP INFORM ignored"; |
149 |
} else { |
150 |
warn "$messagetype igored (bootp?)"; |
151 |
} |
152 |
|
153 |
warn ">> $mac == $ip server: $server::ip", $pxe::file ? " pxe file: $pxe::file\n" : "\n"; |
154 |
|
155 |
$packet = new Net::DHCP::Packet( %$packet ); |
156 |
warn "## ",$packet->toString(),"\n" if $debug; |
157 |
|
158 |
my $reply = IO::Socket::INET->new( |
159 |
LocalAddr => $server::ip, |
160 |
LocalPort => 67, |
161 |
Proto => "udp", |
162 |
Broadcast => 1, |
163 |
PeerAddr => '255.255.255.255', |
164 |
PeerPort => 68, |
165 |
Reuse => 1, |
166 |
) or die "socket: $@"; |
167 |
|
168 |
my $buff = $packet->serialize(); |
169 |
$reply->send( $buff, 0 ) or die "Error sending: $!\n"; |
170 |
|
171 |
# system("arp -s $ip $mac"), |
172 |
|
173 |
} |
174 |
|
175 |
sub start { |
176 |
|
177 |
my $sock = IO::Socket::INET->new( |
178 |
LocalPort => 67, |
179 |
# LocalAddr => 'localhost', |
180 |
# LocalAddr => '10.0.0.100', |
181 |
LocalAddr => '0.0.0.0', |
182 |
Proto => 'udp', |
183 |
ReuseAddr => 1, |
184 |
# PeerPort => getservbyname('bootpc', 'udp'), |
185 |
Broadcast => 1, |
186 |
Type => SOCK_DGRAM, |
187 |
) or die "Failed to bind to socket: $@"; |
188 |
|
189 |
print "DHCP listen on ",$sock->sockhost,":",$sock->sockport,"\n"; |
190 |
|
191 |
while (1) { |
192 |
Module::Refresh->refresh; |
193 |
process_packet $sock; |
194 |
} |
195 |
} |
196 |
|
197 |
warn "loaded"; |
198 |
|
199 |
1; |