# Net::DNS::RR::OPT - phpMan

## NAME
    [Net::DNS::RR::OPT] - DNS OPT resource record

## SYNOPSIS
        use [Net::DNS];
        $packet = [Net::DNS::Packet]->new( ... );

        $packet->header->[do(1)];                     # extended flag

        $packet->edns->[size(1280)];                  # UDP payload size

        $packet->edns->option( COOKIE => 'rawbytes' );

        $packet->edns->print;

        ;; EDNS version 0
        ;;      flags:  8000
        ;;      rcode:  NOERROR
        ;;      size:   1280
        ;;      option: COOKIE => ( 7261776279746573 )
        ;;              DAU    => ( 8, 10, 13, 14, 15, 16 )
        ;;              DHU    => ( 1, 2, 4 )
        ;;              EXTENDED-ERROR => ( INFO-CODE => 123, EXTRA-TEXT =>  )

## DESCRIPTION
    EDNS OPT pseudo resource record.

    The OPT record supports EDNS protocol extensions and is not intended to
    be created, accessed or modified directly by user applications.

    All EDNS features are performed indirectly by operations on the objects
    returned by the $packet->header and $packet->edns creator methods. The
    underlying mechanisms are entirely hidden from the user.

## METHODS
    The available methods are those inherited from the base class augmented
    by the type-specific methods defined in this package.

    Use of undocumented package features or direct access to internal data
    structures is discouraged and could result in program termination or
    other unpredictable behaviour.

  version
        $version = $rr->version;
        $rr->version( $version );

    The version of EDNS supported by this OPT record.

  size
            $size = $packet->edns->size;
            $more = $packet->edns->[size(1280)];

    size() advertises the maximum size (octets) of UDP packet that can be
    reassembled in the network stack of the originating host.

  rcode
            $extended_rcode   = $packet->header->rcode;
            $incomplete_rcode = $packet->edns->rcode;

    The 12 bit extended RCODE. The most significant 8 bits reside in the OPT
    record. The least significant 4 bits can only be obtained from the
    packet header.

  flags
            $edns_flags = $packet->edns->flags;

            $do = $packet->header->do;
            $packet->header->[do(1)];

    16 bit field containing EDNS extended header flags.

  options, option
            @option = $packet->edns->options;

            $octets = $packet->edns->option($option_code);

            $packet->edns->option( COOKIE => $octets );
            $packet->edns->option( 10     => $octets );

    When called in a list context, options() returns a list of option codes
    found in the OPT record.

    When called in a scalar context with a single argument, option() returns
    the uninterpreted octet string corresponding to the specified option.
    The method returns undef if the specified option is absent.

    Options can be added or replaced by providing the (name => value) pair.
    The option is deleted if the value is undefined.

    When option() is called in a list context with a single argument, the
    returned values provide a structured interpretation appropriate to the
    specified option.

    For example:

            @algorithms = $packet->edns->option('DAU');

    For some options, a hash table is more convenient:

            %hash_table = $packet->edns->[option(15)];
            $info_code  = $hash_table{'INFO-CODE'};
            $extra_text = $hash_table{'EXTRA-TEXT'};

    Similar forms of array or hash syntax may be used to construct the
    option value:

            $packet->edns->option( DHU => [1, 2, 4] );

            $packet->edns->option( EXPIRE => {'EXPIRE-TIMER' => 604800} );

## COPYRIGHT
    Copyright (c)2001,2002 RIPE NCC. Author Olaf M. Kolkman.

    Portions Copyright (c)2012,2017-2020 Dick Franks.

    All rights reserved.

    Package template (c)2009,2012 O.M.Kolkman and R.W.Franks.

## LICENSE
    Permission to use, copy, modify, and distribute this software and its
    documentation for any purpose and without fee is hereby granted,
    provided that the original copyright notices appear in all copies and
    that both copyright notice and this permission notice appear in
    supporting documentation, and that the name of the author not be used in
    advertising or publicity pertaining to distribution of the software
    without specific prior written permission.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
    OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
    IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
    CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
    TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
    SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

## SEE ALSO
    perl, [Net::DNS], [Net::DNS::RR], RFC6891, RFC3225