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 IO::Socket::INET; |
9 |
use Net::DHCP::Packet; |
10 |
use Net::DHCP::Constants; |
11 |
use Data::Dump qw/dump/; |
12 |
|
13 |
die "need to run $0 as root like this\nsudo $0\n" unless $< == 0; |
14 |
|
15 |
my $debug = shift @ARGV; |
16 |
|
17 |
our ( $server_ip, $next_file ); |
18 |
require "config.pl"; |
19 |
|
20 |
my $sock = IO::Socket::INET->new( |
21 |
LocalPort => 67, |
22 |
# LocalAddr => 'localhost', |
23 |
# LocalAddr => '10.0.0.100', |
24 |
LocalAddr => '0.0.0.0', |
25 |
Proto => 'udp', |
26 |
ReuseAddr => 1, |
27 |
# PeerPort => getservbyname('bootpc', 'udp'), |
28 |
Broadcast => 1, |
29 |
Type => SOCK_DGRAM, |
30 |
) or die "Failed to bind to socket: $@"; |
31 |
|
32 |
my $_ip = 10; |
33 |
my $_mac2ip; |
34 |
|
35 |
sub client_ip { |
36 |
my ( $mac ) = @_; |
37 |
|
38 |
my $ip = $_mac2ip->{$mac}; |
39 |
return $ip if $ip; |
40 |
|
41 |
$ip = "10.0.0.$_ip"; |
42 |
$_mac2ip->{$mac} = $ip; |
43 |
|
44 |
$_ip++; |
45 |
if ( $_ip == 100 ) { |
46 |
warn "IP roll-over to 10\n"; |
47 |
$_ip = 10; |
48 |
} |
49 |
|
50 |
return $ip; |
51 |
} |
52 |
|
53 |
while (1) { |
54 |
|
55 |
print "waiting for DHCP requests on ",$sock->sockhost,":",$sock->sockport,"\n"; |
56 |
|
57 |
my $buf; |
58 |
$sock->recv($buf, 1024); |
59 |
print "<< peer:",$sock->peerhost,":",$sock->peerport,"\n"; |
60 |
|
61 |
if (defined $buf) { |
62 |
|
63 |
my $dhcp; |
64 |
|
65 |
eval { $dhcp = Net::DHCP::Packet->new($buf); }; |
66 |
die "can't use request", dump( $buf ) if $@; |
67 |
|
68 |
if ( $debug ) { |
69 |
warn "recv: ", $dhcp->toString, "\n\n"; |
70 |
} |
71 |
|
72 |
my $mac = substr($dhcp->chaddr(),0,$dhcp->hlen()*2); |
73 |
my $ip = client_ip($mac); |
74 |
|
75 |
my $file = $next_file; |
76 |
$file = 'undionly.kpxe' if ! $file || $dhcp->getOptionValue(DHO_USER_CLASS()) ne 'gPXE'; |
77 |
|
78 |
my $packet = new Net::DHCP::Packet( |
79 |
Op => BOOTREPLY(), |
80 |
Hops => $dhcp->hops(), |
81 |
Xid => $dhcp->xid(), |
82 |
Flags => $dhcp->flags(), |
83 |
Ciaddr => $dhcp->ciaddr(), |
84 |
Yiaddr => $ip, |
85 |
Siaddr => $server_ip, |
86 |
Giaddr => $dhcp->giaddr(), |
87 |
Chaddr => $dhcp->chaddr(), |
88 |
File => $file, |
89 |
# DHO_DHCP_MESSAGE_TYPE() => DHCPACK(), |
90 |
DHO_SUBNET_MASK() => '255.0.0.0', |
91 |
); |
92 |
|
93 |
warn ">> $mac == $ip server $server_ip\n"; |
94 |
|
95 |
warn "## ",$packet->toString(),"\n" if $debug; |
96 |
|
97 |
my $reply = IO::Socket::INET->new( |
98 |
LocalAddr => $server_ip, |
99 |
LocalPort => 67, |
100 |
Proto => "udp", |
101 |
Broadcast => 1, |
102 |
PeerAddr => '255.255.255.255', |
103 |
PeerPort => 68, |
104 |
Reuse => 1, |
105 |
) or die "socket: $@"; |
106 |
|
107 |
my $buff = $packet->serialize(); |
108 |
$reply->send( $buff, 0 ) or die "Error sending: $!\n"; |
109 |
|
110 |
# system("arp -s $ip $mac"), |
111 |
|
112 |
} else { |
113 |
print "No bootp request.\n"; |
114 |
} |
115 |
|
116 |
} |