lib::Net::DNS::UsereContributed Perl Doculib::Net::DNS::Header(3)NAMENet::DNS::Header - DNS packet header class
SYNOPSIS
use Net::DNS::Header;
DESCRIPTION
A Net::DNS::Header object represents the header portion of
a DNS packet.
METHODS
new
$header = new Net::DNS::Header;
$header = new Net::DNS::Header(\$data);
Without an argument, new creates a header object
appropriate for making a DNS query.
If new is passed a reference to a scalar containing DNS
packet data, it creates a header object from that data.
Returns undef if unable to create a header object (e.g.,
if the data is incomplete).
print
$header->print;
Dumps the header data to the standard output.
string
print $header->string;
Returns a string representation of the header object.
id
print "query id = ", $header->id, "\n";
$header->id(1234);
Gets or sets the query identification number.
qr
print "query response flag = ", $header->qr, "\n";
$header->qr(0);
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Gets or sets the query response flag.
opcode
print "query opcode = ", $header->opcode, "\n";
$header->opcode("UPDATE");
Gets or sets the query opcode (the purpose of the query).
aa
print "answer is ", $header->aa ? "" : "non-", "authoritative\n";
$header->aa(0);
Gets or sets the authoritative answer flag.
tc
print "packet is ", $header->tc ? "" : "not ", "truncated\n";
$header->tc(0);
Gets or sets the truncated packet flag.
rd
print "recursion was ", $header->rd ? "" : "not ", "desired\n";
$header->rd(0);
Gets or sets the recursion desired flag.
ra
print "recursion is ", $header->ra ? "" : "not ", "available\n";
$header->ra(0);
Gets or sets the recursion available flag.
rcode
print "query response code = ", $header->rcode, "\n";
$header->rcode("SERVFAIL");
Gets or sets the query response code (the status of the
query).
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qdcount, zocount
print "# of question records: ", $header->qdcount, "\n";
$header->qdcount(2);
Gets or sets the number of records in the question section
of the packet. In dynamic update packets, this field is
known as zocount and refers to the number of RRs in the
zone section.
ancount, prcount
print "# of answer records: ", $header->ancount, "\n";
$header->ancount(5);
Gets or sets the number of records in the answer section
of the packet. In dynamic update packets, this field is
known as prcount and refers to the number of RRs in the
prerequisite section.
nscount, upcount
print "# of authority records: ", $header->nscount, "\n";
$header->nscount(2);
Gets or sets the number of records in the authority
section of the packet. In dynamic update packets, this
field is known as upcount and refers to the number of RRs
in the update section.
arcount, adcount
print "# of additional records: ", $header->arcount, "\n";
$header->arcount(3);
Gets or sets the number of records in the additional
section of the packet. In dynamic update packets, this
field is known as adcount.
data
$hdata = $header->data;
Returns the header data in binary format, appropriate for
use in a DNS query packet.
COPYRIGHT
Copyright (c) 1997 Michael Fuhr. All rights reserved.
This program is free software; you can redistribute it
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and/or modify it under the same terms as Perl itself.
SEE ALSO
the perl(1) manpage, the Net::DNS manpage, the
Net::DNS::Resolver manpage, the Net::DNS::Packet manpage,
the Net::DNS::Update manpage, the Net::DNS::Question
manpage, the Net::DNS::RR manpage, RFC 1035 Section 4.1.1
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