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Gentoo: libspf2 DNS response buffer overflow
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Net::DNS::Nameserver(3) User Contributed Perl Documentation Net::DNS::Nameserver(3) NAME
Net::DNS::Nameserver - DNS server class SYNOPSIS
"use Net::DNS::Nameserver;" DESCRIPTION
Instances of the "Net::DNS::Nameserver" class represent simple DNS server objects. See "EXAMPLE" for an example. METHODS
new my $ns = Net::DNS::Nameserver->new( LocalAddr => "10.1.2.3", LocalPort => "5353", ReplyHandler => &reply_handler, Verbose => 1 ); Creates a nameserver object. Attributes are: LocalAddr IP address on which to listen. Defaults to INADDR_ANY. LocalPort Port on which to listen. Defaults to 53. ReplyHandler Reference to reply-handling subroutine. Required. Verbose Print info about received queries. Defaults to 0 (off). The ReplyHandler subroutine is passed the query name, query class, and query type. It must return the response code and references to the answer, authority, and additional sections of the response. Common response codes are: NOERROR No error FORMERR Format error SERVFAIL Server failure NXDOMAIN Non-existent domain (name doesn't exist) NOTIMP Not implemented REFUSED Query refused See RFC 1035 and the IANA dns-parameters file for more information: ftp://ftp.rfc-editor.org/in-notes/rfc1035.txt http://www.isi.edu/in-notes/iana/assignments/dns-parameters The nameserver will listen for both UDP and TCP connections. On Unix-like systems, the program will probably have to run as root to listen on the default port, 53. A non-privileged user should be able to listen on ports 1024 and higher. Returns a Net::DNS::Nameserver object, or undef if the object couldn't be created. See "EXAMPLE" for an example. main_loop $ns->main_loop; Start accepting queries. EXAMPLE
The following example will listen on port 5353 and respond to all queries for A records with the IP address 10.1.2.3. All other queries will be answered with NXDOMAIN. Authority and additional sections are left empty. #!/usr/bin/perl -Tw use Net::DNS; use strict; sub reply_handler { my ($qname, $qclass, $qtype) = @_; my ($rcode, @ans, @auth, @add); if ($qtype eq "A") { my ($ttl, $rdata) = (3600, "10.1.2.3"); push @ans, Net::DNS::RR->new("$qname $ttl $qclass $qtype $rdata"); $rcode = "NOERROR"; } else { $rcode = "NXDOMAIN"; } return ($rcode, @ans, @auth, @add); } my $ns = Net::DNS::Nameserver->new( LocalPort => 5353, ReplyHandler => &reply_handler, Verbose => 1 ); if ($ns) { $ns->main_loop; } else { die "couldn't create nameserver object "; } BUGS
Net::DNS::Nameserver objects can handle only one query at a time. COPYRIGHT
Copyright (c) 2000-2002 Michael Fuhr. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. SEE ALSO
perl(1), Net::DNS, Net::DNS::Resolver, Net::DNS::Packet, Net::DNS::Update, Net::DNS::Header, Net::DNS::Question, Net::DNS::RR, RFC 1035 perl v5.8.0 2002-05-31 Net::DNS::Nameserver(3)
