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