add a toy name server that replies from the wrong address

bin/dig/include/dig/dig.h

@@ -142,8 +142,8 @@ struct dig_lookup {
 		idnout,
 		expandaaaa,
 		qr,
-		accept_reply_unexpected_src;  /*%  print replies from unexpected 
-					           sources. */
+		accept_reply_unexpected_src;  /*%  print replies from unexpected
+						   sources. */
 	char textname[MXNAME]; /*% Name we're going to be looking up */
 	char cmdline[MXNAME];
 	dns_rdatatype_t rdtype;

bin/tests/system/digdelv/ans6/ans.pl

+#!/usr/bin/perl -w
+#
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+use IO::File;
+use IO::Socket;
+use Net::DNS;
+use Net::DNS::Packet;
+
+my $localport = int($ENV{'PORT'});
+if (!$localport) { $localport = 5300; }
+
+my $sock = IO::Socket::INET->new(LocalAddr => "10.53.0.6",
+   LocalPort => $localport, Proto => "udp") or die "$!";
+
+my $pidf = new IO::File "ans.pid", "w" or die "cannot open pid file: $!";
+print $pidf "$$\n" or die "cannot write pid file: $!";
+$pidf->close or die "cannot close pid file: $!";
+sub rmpid { unlink "ans.pid"; exit 1; };
+
+$SIG{INT} = \&rmpid;
+$SIG{TERM} = \&rmpid;
+
+for (;;) {
+	$sock->recv($buf, 512);
+
+	print "**** request from " , $sock->peerhost, " port ", $sock->peerport, "\n";
+
+	my $packet;
+
+	if ($Net::DNS::VERSION > 0.68) {
+		$packet = new Net::DNS::Packet(\$buf, 0);
+		$@ and die $@;
+	} else {
+		my $err;
+		($packet, $err) = new Net::DNS::Packet(\$buf, 0);
+		$err and die $err;
+	}
+
+	print "REQUEST:\n";
+	$packet->print;
+
+	$packet->header->qr(1);
+
+	my @questions = $packet->question;
+	my $qname = $questions[0]->qname;
+	my $qtype = $questions[0]->qtype;
+
+	my $donotrespond = 0;
+
+	$packet->header->aa(1);
+	if ($qtype eq "A") {
+		$packet->push("answer",
+			      new Net::DNS::RR($qname .  " 300 A 10.53.0.5"));
+	} else {
+		$donotrespond = 1;
+	}
+
+	if ($donotrespond == 0) {
+                my $sendsock =
+                        IO::Socket::INET->new(LocalAddr => "10.53.1.2",
+                                              PeerAddr => $sock->peerhost,
+                                              PeerPort => "5300",
+                                              Proto => "udp") or die "$!";
+                print "**** response from ", $sendsock->sockhost, " to " ,
+                      $sendsock->peerhost, " port ", $sendsock->peerport, "\n";
+		$sendsock->send($packet->data);
+                $sendsock->close;
+		print "RESPONSE:\n";
+		$packet->print;
+		print "\n";
+	} else {
+		print "DROP:\n";
+	}
+}

util/copyrights

@@ -497,6 +497,7 @@
 ./bin/tests/system/digcomp.pl			PERL	2000,2001,2004,2007,2012,2013,2016,2018,2019
 ./bin/tests/system/digdelv/ans4/startme		X	2017,2018,2019
 ./bin/tests/system/digdelv/ans5/ans.pl		PERL	2019
+./bin/tests/system/digdelv/ans6/ans.pl		PERL	2019
 ./bin/tests/system/digdelv/clean.sh		SH	2015,2016,2018,2019
 ./bin/tests/system/digdelv/ns2/sign.sh		SH	2018,2019
 ./bin/tests/system/digdelv/prereq.sh		SH	2018,2019