1 |
#!/usr/bin/perl |
2 |
|
3 |
# based on http://www.perlmonks.org/index.pl?node_id=325248 |
4 |
|
5 |
use strict; |
6 |
use warnings; |
7 |
|
8 |
use autodie; |
9 |
|
10 |
use IO::Socket::INET; |
11 |
use File::Slurp; |
12 |
use Data::Dump qw/dump/; |
13 |
|
14 |
use lib 'lib'; |
15 |
use Net::DHCP::Packet; |
16 |
use Net::DHCP::Constants 0.67; |
17 |
die "need to run $0 as root like this\nsudo $0\n" unless $< == 0; |
18 |
|
19 |
my $debug = shift @ARGV; |
20 |
|
21 |
our ( $file, $gpxe_file ); |
22 |
our ( $ip_from, $ip_to ) = ( 10, 100 ); |
23 |
|
24 |
our $server_ip = readlink 'conf/server.ip' if -l 'conf/server.ip'; |
25 |
|
26 |
if ( ! $server_ip ) { |
27 |
$server_ip = `/sbin/ifconfig`; |
28 |
$server_ip =~ s/^.+?addr:([\d\.]+).*$/$1/gs; |
29 |
warn "auto-configure server ip to $server_ip\n"; |
30 |
} else { |
31 |
warn "server ip $server_ip\n"; |
32 |
} |
33 |
|
34 |
my $sock = IO::Socket::INET->new( |
35 |
LocalPort => 67, |
36 |
# LocalAddr => 'localhost', |
37 |
# LocalAddr => '10.0.0.100', |
38 |
LocalAddr => '0.0.0.0', |
39 |
Proto => 'udp', |
40 |
ReuseAddr => 1, |
41 |
# PeerPort => getservbyname('bootpc', 'udp'), |
42 |
Broadcast => 1, |
43 |
Type => SOCK_DGRAM, |
44 |
) or die "Failed to bind to socket: $@"; |
45 |
|
46 |
|
47 |
my $addr = $ip_from; |
48 |
|
49 |
sub client_ip { |
50 |
my ( $mac ) = @_; |
51 |
|
52 |
my $conf = "conf/$server_ip"; |
53 |
mkdir $conf unless -e $conf; |
54 |
|
55 |
if ( -e "$conf/mac/$mac" ) { |
56 |
my $ip = read_file "$conf/mac/$mac"; |
57 |
print "$mac old $ip\n"; |
58 |
return $ip; |
59 |
} |
60 |
|
61 |
mkdir $_ foreach grep { ! -e $_ } map { "$conf/$_" } ( 'ip', 'mac' ); |
62 |
|
63 |
my $prefix = $server_ip; |
64 |
$prefix =~ s{\.\d+$}{.}; |
65 |
my $ip = $prefix . $addr; |
66 |
while ( -e "conf/ip/$ip" ) { |
67 |
$ip = $prefix . $addr++; |
68 |
die "all addresses allocated!" if $addr == $ip_to; |
69 |
} |
70 |
|
71 |
write_file "$conf/mac/$mac", $ip; |
72 |
unlink "$conf/ip/$ip" if -e "$conf/ip/$ip"; |
73 |
symlink "$conf/mac/$mac", "$conf/ip/$ip"; |
74 |
|
75 |
print "$mac NEW $ip\n"; |
76 |
|
77 |
return $ip; |
78 |
} |
79 |
|
80 |
my $transaction = 0; # FIXME predictible transaction numbers |
81 |
|
82 |
while (1) { |
83 |
|
84 |
require "config.pl"; # refresh config |
85 |
|
86 |
print "waiting for DHCP requests on ",$sock->sockhost,":",$sock->sockport,"\n"; |
87 |
|
88 |
my $buf; |
89 |
$sock->recv($buf, 1024); |
90 |
print "<< ",$sock->peerhost,":",$sock->peerport,"\n"; |
91 |
|
92 |
if (defined $buf) { |
93 |
|
94 |
my $dhcp = Net::DHCP::Packet->new($buf); |
95 |
$dhcp->comment( $transaction++ ); |
96 |
|
97 |
warn "recv: ", $dhcp->toString, "\n\n"; |
98 |
|
99 |
my $mac = substr($dhcp->chaddr(),0,$dhcp->hlen()*2); |
100 |
my $ip = client_ip($mac); |
101 |
my $user_class = $dhcp->getOptionValue(DHO_USER_CLASS()); |
102 |
|
103 |
if ( $user_class eq 'gPXE' ) { |
104 |
$file = $gpxe_file; |
105 |
} elsif ( ! $file ) { |
106 |
$file = 'undionly.kpxe'; |
107 |
} |
108 |
|
109 |
my $packet = { |
110 |
Op => BOOTREPLY(), |
111 |
Hops => $dhcp->hops(), |
112 |
Xid => $dhcp->xid(), |
113 |
Flags => $dhcp->flags(), |
114 |
Ciaddr => $dhcp->ciaddr(), |
115 |
Yiaddr => $ip, |
116 |
Siaddr => $server_ip, |
117 |
Giaddr => $dhcp->giaddr(), |
118 |
Chaddr => $dhcp->chaddr(), |
119 |
File => $file, |
120 |
# DHO_DHCP_MESSAGE_TYPE() => DHCPACK(), |
121 |
# DHO_SUBNET_MASK() => '255.255.255.0', |
122 |
}; |
123 |
|
124 |
my $messagetype = $dhcp->getOptionValue(DHO_DHCP_MESSAGE_TYPE()); |
125 |
|
126 |
if ($messagetype eq DHCPDISCOVER()) { |
127 |
warn "DHCP DISCOVER"; |
128 |
$packet->{Comment} = $dhcp->comment(); |
129 |
$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPOFFER(); |
130 |
} elsif ($messagetype eq DHCPREQUEST()) { |
131 |
my $requested_ip = $dhcp->getOptionValue(DHO_DHCP_REQUESTED_ADDRESS()); |
132 |
warn "DHCP REQUEST $requested_ip"; |
133 |
if ( $ip eq $requested_ip ) { |
134 |
$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPACK(); |
135 |
$packet->{DHO_DHCP_LEASE_TIME()} = 100; |
136 |
} else { |
137 |
$packet->{DHO_DHCP_MESSAGE_TYPE()} = DHCPNAK(); |
138 |
$packet->{DHO_DHCP_MESSAGE()} = "Bad request, expected $ip"; |
139 |
} |
140 |
} elsif ($messagetype eq DHCPINFORM()) { |
141 |
warn "DHCP INFORM ignored"; |
142 |
} else { |
143 |
warn "$messagetype igored (bootp?)"; |
144 |
} |
145 |
|
146 |
|
147 |
warn ">> $mac == $ip server: $server_ip", $file ? " file: $file\n" : "\n"; |
148 |
|
149 |
$packet = new Net::DHCP::Packet( %$packet ); |
150 |
warn "## ",$packet->toString(),"\n" if $debug; |
151 |
|
152 |
my $reply = IO::Socket::INET->new( |
153 |
LocalAddr => $server_ip, |
154 |
LocalPort => 67, |
155 |
Proto => "udp", |
156 |
Broadcast => 1, |
157 |
PeerAddr => '255.255.255.255', |
158 |
PeerPort => 68, |
159 |
Reuse => 1, |
160 |
) or die "socket: $@"; |
161 |
|
162 |
my $buff = $packet->serialize(); |
163 |
$reply->send( $buff, 0 ) or die "Error sending: $!\n"; |
164 |
|
165 |
# system("arp -s $ip $mac"), |
166 |
|
167 |
} else { |
168 |
print "No bootp request.\n"; |
169 |
} |
170 |
|
171 |
} |