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 |
|
22 |
use lib '..'; |
23 |
use Net::DHCP::Packet; |
24 |
use Net::DHCP::Constants 0.67; |
25 |
|
26 |
use server; |
27 |
my $debug = server::debug; |
28 |
|
29 |
if ( ! $server::ip ) { |
30 |
my $server_ip = `/sbin/ifconfig`; |
31 |
$server_ip =~ s/^.+?addr:([\d\.]+).*$/$1/gs; |
32 |
$server::ip = $server_ip; |
33 |
} |
34 |
|
35 |
warn "server ip $server::ip range: $server::ip_from - $server::ip_to\n"; |
36 |
|
37 |
use client; |
38 |
|
39 |
sub client_ip { |
40 |
my ( $mac ) = @_; |
41 |
|
42 |
my $conf = $server::conf; |
43 |
mkdir $conf unless -e $conf; |
44 |
|
45 |
if ( -e "$conf/mac/$mac" ) { |
46 |
my $ip = read_file "$conf/mac/$mac"; |
47 |
print "RENEW $mac $ip\n"; |
48 |
return $ip; |
49 |
} |
50 |
|
51 |
my $ip = client::next_ip; |
52 |
|
53 |
write_file "$conf/mac/$mac", $ip; |
54 |
|
55 |
my $ip_path = "$conf/ip/$ip"; |
56 |
mkdir $ip_path unless -e $ip_path; |
57 |
|
58 |
if ( -l "$ip_path/mac" && readlink "$ip_path/mac" ne "$conf/mac/$mac" ) { |
59 |
warn "$mac IP changed from ", readlink "$ip_path/mac", " to $ip"; |
60 |
unlink "$ip_path/mac"; |
61 |
}; |
62 |
symlink "$conf/mac/$mac", "$ip_path/mac"; |
63 |
|
64 |
print "$mac NEW $ip\n"; |
65 |
|
66 |
return $ip; |
67 |
} |
68 |
|
69 |
use log; |
70 |
use config; |
71 |
use pxelinux; |
72 |
use client; |
73 |
|
74 |
our $file; |
75 |
our $transaction = 0; # FIXME predictible transaction numbers |
76 |
|
77 |
sub process_packet { |
78 |
my $sock = shift; |
79 |
|
80 |
server->refresh; |
81 |
|
82 |
my $buf; |
83 |
$sock->recv($buf, 1024); |
84 |
my $size = 'empty'; |
85 |
$size = length($buf) . ' bytes' if defined $buf; |
86 |
|
87 |
print "packet from ",$sock->peerhost,":",$sock->peerport," $size\n" if $debug; |
88 |
return unless $buf; |
89 |
|
90 |
my $dhcp = Net::DHCP::Packet->new($buf); |
91 |
$dhcp->comment( $transaction++ ); |
92 |
|
93 |
warn "recv: ", $dhcp->toString if $debug; |
94 |
|
95 |
my $mac = substr($dhcp->chaddr(),0,$dhcp->hlen()*2); |
96 |
my $ip = client_ip($mac); |
97 |
|
98 |
=for later |
99 |
|
100 |
my $user_class = $dhcp->getOptionValue(DHO_USER_CLASS()); |
101 |
|
102 |
if ( $user_class eq 'gPXE' ) { |
103 |
$file = $gpxe_file; |
104 |
} elsif ( ! $file ) { |
105 |
$file = 'undionly.kpxe'; |
106 |
} |
107 |
|
108 |
=cut |
109 |
|
110 |
config::for_ip( $ip ); |
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 => $file, |
123 |
DHO_DHCP_SERVER_IDENTIFIER() => $server::ip, # busybox/udhcpc needs it but doesn't request |
124 |
}; |
125 |
|
126 |
my $options = { |
127 |
DHO_SUBNET_MASK() => $server::netmask, |
128 |
DHO_ROUTERS() => $server::ip, |
129 |
DHO_DOMAIN_NAME() => $server::domain_name, |
130 |
DHO_NAME_SERVERS() => $server::ip, |
131 |
DHO_DOMAIN_NAME_SERVERS() => $server::ip, |
132 |
DHO_HOST_NAME() => client::conf( $ip, 'hostname' ), |
133 |
DHO_BROADCAST_ADDRESS() => $server::bcast, |
134 |
# DHO_NTP_SERVERS() => '', |
135 |
}; |
136 |
|
137 |
my @requested = split(/\s/, $dhcp->getOptionValue(DHO_DHCP_PARAMETER_REQUEST_LIST)); |
138 |
warn "options ",dump( $options ), ' requested: ',dump( @requested ) if $debug; |
139 |
|
140 |
my @missing; |
141 |
foreach ( @requested ) { |
142 |
if ( defined $options->{$_} ) { |
143 |
$packet->{$_} = $options->{$_}; |
144 |
} else { |
145 |
push @missing, $_; |
146 |
} |
147 |
} |
148 |
|
149 |
warn "W: options requested but missing: ",dump( @missing ),$/; |
150 |
|
151 |
foreach my $opt ( 'magic', 'config_file', 'path_prefix', 'reboot_time' ) { |
152 |
my $DH0 = eval 'DHO_PXELINUX_' . uc $opt; |
153 |
warn "DH0: $@" if $@; |
154 |
my $v = eval "\$pxelinux::$opt"; |
155 |
warn "v: $@" if $@; |
156 |
next unless defined $v; |
157 |
warn "pxelinux dhcp option $opt = $DH0 = $v\n" if $debug; |
158 |
$packet->{ $DH0 } = $v; |
159 |
} |
160 |
|
161 |
my $messagetype = $dhcp->getOptionValue(DHO_DHCP_MESSAGE_TYPE()); |
162 |
|
163 |
if ($messagetype eq DHCPDISCOVER()) { |
164 |
log::mac $mac, "DHCP DISCOVER"; |
165 |
$packet->{Comment} = $dhcp->comment(); |
166 |
$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPOFFER(); |
167 |
} elsif ($messagetype eq DHCPREQUEST()) { |
168 |
my $requested_ip = $dhcp->getOptionValue(DHO_DHCP_REQUESTED_ADDRESS()); |
169 |
log::mac $mac, "DHCP REQUEST $requested_ip $ip $file"; |
170 |
if ( $ip eq $requested_ip ) { |
171 |
$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPACK(); |
172 |
$packet->{DHO_DHCP_LEASE_TIME()} = 5 * 60; # 5 min |
173 |
# $packet->{DHO_ROOT_PATH()} = '/exports/foobar'; |
174 |
} else { |
175 |
$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPNAK(); |
176 |
$packet->{DHO_DHCP_MESSAGE()} = "Bad request, expected $ip"; |
177 |
} |
178 |
} elsif ($messagetype eq DHCPINFORM()) { |
179 |
log::mac $mac, "DHCP INFORM ignored"; |
180 |
} else { |
181 |
log::mac $mac, "$messagetype igored (bootp?)"; |
182 |
} |
183 |
|
184 |
warn ">> $mac == $ip server: $server::ip", $file ? " file: $file\n" : "\n" if $debug; |
185 |
|
186 |
$packet = new Net::DHCP::Packet( %$packet ); |
187 |
warn "send ",$packet->toString() if $debug; |
188 |
|
189 |
my $reply = IO::Socket::INET->new( |
190 |
LocalAddr => $server::ip, |
191 |
LocalPort => 67, |
192 |
Proto => "udp", |
193 |
Broadcast => 1, |
194 |
PeerAddr => '255.255.255.255', |
195 |
PeerPort => 68, |
196 |
Reuse => 1, |
197 |
) or die "socket: $@"; |
198 |
|
199 |
my $buff = $packet->serialize(); |
200 |
$reply->send( $buff, 0 ) or die "Error sending: $!\n"; |
201 |
|
202 |
# system("arp -s $ip $mac"), |
203 |
|
204 |
} |
205 |
|
206 |
sub start { |
207 |
|
208 |
my $sock = IO::Socket::INET->new( |
209 |
LocalPort => 67, |
210 |
# LocalAddr => 'localhost', |
211 |
# LocalAddr => '10.0.0.100', |
212 |
LocalAddr => '0.0.0.0', |
213 |
Proto => 'udp', |
214 |
ReuseAddr => 1, |
215 |
# PeerPort => getservbyname('bootpc', 'udp'), |
216 |
Broadcast => 1, |
217 |
Type => SOCK_DGRAM, |
218 |
) or die "Failed to bind to socket: $@"; |
219 |
|
220 |
print "DHCP listen on ",$sock->sockhost,":",$sock->sockport,"\n"; |
221 |
|
222 |
while (1) { |
223 |
process_packet $sock; |
224 |
} |
225 |
} |
226 |
|
227 |
warn "loaded"; |
228 |
|
229 |
1; |