NAME

Nagios::NRPE::Packet - Assembly and de-assembly of an NRPE packet

SYNOPSIS

 use IO::Socket;
 use IO::Socket::INET;
 # Import necessary constants into Namespace
 use Nagios::NRPE::Packet qw(NRPE_PACKET_VERSION_2
		             NRPE_PACKET_QUERY
		             MAX_PACKETBUFFER_LENGTH
		             STATE_UNKNOWN
		             STATE_CRITICAL
		             STATE_WARNING
		             STATE_OK);

 my $packet = Nagios::NRPE::Packet->new();

 my $socket = IO::Socket::INET->new(
                    PeerAddr => $host,
                    PeerPort => $port,
                    Proto    => 'tcp',
                    Type     => SOCK_STREAM) or die "ERROR: $@ \n";

 print $socket $packet->assemble(type => QUERY_PACKET,
                              buffer => "check_load 1 2 3",
                              version => NRPE_PACKET_VERSION_2 );

 my $data = <$socket>
 my $response = $packet->deassemble($data);

 print $response->{buffer};

DESCRIPTION

This class is meant to be used when an active connection exists and is ready to send the packet.

CONSTRUCTION

new

Takes the following options as a hashref

FUNCTIONS

Following functions can be used after the creation of the packet

• assemble

  Takes a hash of options defining the packet to be sent and returns the assembled packet. You can print this to an open socket and send it to either a server or the client depending on your situation.

  check

  A string defining the check to be run or the output of a check eg: "check_cpu" NOTE: Nagios can accept arguments appended to the check in the form: "check_somecheck!ARG1!ARG2!ARG..."

  version

  The NRPE version you want to use (currently only V2 is accepted).

  See CONSTANTS for options here.

  type

  The TYPE of packet you wish to send, which is either QUERY or RESPONSE.

  See CONSTANTS for options here.

  result_code

  This is a curios value as it seems to have no apparent affect on neither the server nor the client.

  A set value is 2324.

• deassemble

  Takes a packet recieved by either client or server and deassembles them. The returned hashref contains the following values:

• packet_type

  crc32_value
  result_code
  buffer

• validate($packet)

  Validates the contents of a packet using CRC32 checksumming. Returns undef if not succesful.

CONSTANTS

These constants can be exported upon request with the 'use' pragma like this:

# Will only import the constant NRPE_PACKET_VERSION_2 into your namespace
use Nagios::NRPE::Packet qw(NRPE_PACKET_VERSION_2);
=over 2

• NRPE_PACKET_VERSION_3 NRPE_PACKET_VERSION_2 NRPE_PACKET_VERSION_1

  The value of the NRPE version you want/need to use.

• QUERY_PACKET RESPONSE_PACKET

  The packet type you want to send or recieve

• MAX_PACKETBUFFER_LENGTH MAX_COMMAND_ARGUMENTS

  A threshhold on the send data

• NRPE_HELLO_COMMAND

  unknown

• DEFAULT_SOCKET_TIMEOUT DEFAULT_CONNECTION_TIMEOUT

  The default timeout for a connection and its corresponding socket

• STATE_UNKNOWN STATE_CRITICAL STATE_WARNING STATE_OK

  States returned by the check

crc32

Checksumming for the packet. Necessary for sending a valid Packet.

packet_dump

Debugging function for hexdumping a binary string.