Net::DHCP::Packet 0.66

Net::DHCP::Packet is a Perl module with object methods to create a DHCP packet.

SYNOPSIS

use Net::DHCP::Packet;

my $p = new Net::DHCP::Packet->new(
Chaddr => 000BCDEF,
Xid => 0x9F0FD,
Ciaddr => 0.0.0.0,
Siaddr => 0.0.0.0,
Hops => 0);

Represents a DHCP packet as specified in RFC 1533, RFC 2132.

CONSTRUCTOR

This module only provides basic constructor. For "easy" constructors, you can use the Net::DHCP::Session module.

new( )

new( BUFFER )

new( ARG => VALUE, ARG => VALUE... )

Creates an Net::DHCP::Packet object, which can be used to send or receive DHCP network packets. BOOTP is not supported.

Without argument, a default empty packet is created.

$packet = Net::DHCP::Packet();

A BUFFER argument is interpreted as a binary buffer like one provided by the socket recv() function. if the packet is malformed, a fatal error is issued.

use IO::Socket::INET;
use Net::DHCP::Packet;

$sock = IO::Socket::INET->new(LocalPort => 67, Proto => "udp", Broadcast => 1)
or die "socket: $@";

while ($sock->recv($newmsg, 1024)) {
$packet = Net::DHCP::Packet->new($newmsg);
print $packet->toString();
}

To create a fresh new packet new() takes arguments as a key-value pairs :

ARGUMENT FIELD OCTETS DESCRIPTION
-------- ----- ------ -----------

Op op 1 Message op code / message type.
1 = BOOTREQUEST, 2 = BOOTREPLY
Htype htype 1 Hardware address type, see ARP section in "Assigned
Numbers" RFC; e.g., 1 = 10mb ethernet.
Hlen hlen 1 Hardware address length (e.g. 6 for 10mb
ethernet).
Hops hops 1 Client sets to zero, optionally used by relay agents
when booting via a relay agent.
Xid xid 4 Transaction ID, a random number chosen by the
client, used by the client and server to associate
messages and responses between a client and a
server.
Secs secs 2 Filled in by client, seconds elapsed since client
began address acquisition or renewal process.
Flags flags 2 Flags (see figure 2).
Ciaddr ciaddr 4 Client IP address; only filled in if client is in
BOUND, RENEW or REBINDING state and can respond
to ARP requests.
Yiaddr yiaddr 4 your (client) IP address.
Siaddr siaddr 4 IP address of next server to use in bootstrap;
returned in DHCPOFFER, DHCPACK by server.
Giaddr giaddr 4 Relay agent IP address, used in booting via a
relay agent.
Chaddr chaddr 16 Client hardware address.
Sname sname 64 Optional server host name, null terminated string.
File file 128 Boot file name, null terminated string; "generic"
name or null in DHCPDISCOVER, fully qualified
directory-path name in DHCPOFFER.
IsDhcp isDhcp 4 Controls whether the packet is BOOTP or DHCP.
DHCP conatains the "magic cookie" of 4 bytes.
0x63 0x82 0x53 0x63.
DHO_*code Optional parameters field. See the options
documents for a list of defined options.
See Net::DHCP::Constants.
Padding padding * Optional padding at the end of the packet

See below methods for values and syntax descrption.

Note: DHCP options are created in the same order as key-value pairs.