X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=chiark-utils.git;a=blobdiff_plain;f=scripts%2Fnamed-conf;h=a7894f510fbccbbb1ab919b2f76110c255c47718;hp=a54db8277c5c26adfbe4dff32435ab21535f9f8c;hb=c4441d680a870752e80ad0dfd839c9fa1d24c062;hpb=5ed8bc665fbc0fc51dbfebdeed49153686e26699

diff --git a/scripts/named-conf b/scripts/named-conf
index a54db82..a7894f5 100755
--- a/scripts/named-conf
+++ b/scripts/named-conf
@@ -19,7 +19,7 @@ $where= '<built-in>';
 $debug= 0;
 $needglue= 1;
 $localonly= 0;
-$verbosity= 1;
+$verbosity= 2;
 $repeat= 0;
 
 use vars qw($dig_owner $dig_type $dig_rdata);
@@ -33,9 +33,9 @@ while (@ARGV && $ARGV[0] =~ m/^\-/) {
 	elsif (m/^config$/) { $etcfile= loarg(); $where= '--config option'; }
 	elsif (m/^glueless$/) { $needglue=0; }
 	elsif (m/^localonly$/) { $localonly=1; }
-	elsif (m/^quiet$/) { $verbosity=0; }
+	elsif (m/^quiet$/) { $verbosity--; }
 	elsif (m/^repeat$/) { $repeat=1; }
-	elsif (m/^verbose$/) { $verbosity=2; }
+	elsif (m/^verbose$/) { $verbosity++; }
 	else { usageerr("unknown option --$_"); }
     } else {
 	s/^\-//;
@@ -47,9 +47,9 @@ while (@ARGV && $ARGV[0] =~ m/^\-/) {
 	    elsif (s/^D//) { $debug++; }
 	    elsif (s/^g//) { $needglue=0; }
 	    elsif (s/^l//) { $localonly=1; }
-	    elsif (s/^q//) { $verbosity=0; }
+	    elsif (s/^q//) { $verbosity--; }
 	    elsif (s/^r//) { $repeat=1; }
-	    elsif (s/^v//) { $verbosity=2; }
+	    elsif (s/^v//) { $verbosity++; }
 	    else { usageerr("unknown option -$&"); }
 	}
     }
@@ -58,6 +58,8 @@ while (@ARGV && $ARGV[0] =~ m/^\-/) {
 sub loarg() { usageerr("missing option value") if !@ARGV; return shift @ARGV; }
 sub soarg() { my ($rv); $rv=$_; $_=''; return length $rv ? $rv : loarg(); }
 
+usageerr("-q may be specified at most twice") if $verbosity<0;
+usageerr("-v may be specified at most once") if $verbosity>3;
 usageerr("-D may be specified at most twice") if $debug>2;
 usageerr("must specify either -f|-y|-n or zones (and not both)")
     if !!$mode == !!@ARGV;
@@ -135,7 +137,7 @@ sub read_config ($) {
 	    last;
 	}
 	chomp; s/\s+$//;
-	if (m/\\$/) { $before.= $_; next; }
+	if (s/\\$//) { $before.= $_; next; }
 	$_= $before.$_;
 	$before= '';
 	s/^\s+//;
@@ -200,7 +202,8 @@ sub read_config ($) {
 	    read_config($1);
 	} else {
 	    cfg_fail("unknown configuration directive".
-		     " or incorrect syntax or arguments");
+		     " or incorrect syntax or arguments:\n".
+		     " \`$_'");
 	}
     }
     $fh->close or cfg_fail("close config file $if:\n $!");
@@ -230,10 +233,11 @@ sub zone_conf ($$$$$@) {
     $zone_cfg{$zone}{'style_p'}= $style.$mod;
     $zone_cfg{$zone}{'s'}= $sabbr.$mod; # p)rimary s)econdary u)npub f)oreign
     $zone_cfg{$zone}{'servers'}= [ @servers ];
-    foreach $sfx (qw(soa ns addr)) {
-	{ no strict 'refs'; $aref= [ @{ "self_$sfx" } ]; }
-	@$aref or cfg_fail("failed to specify self-$sfx before zone");
-	$zone_cfg{$zone}{"self_$sfx"}= $aref;
+    foreach $sfx (qw(self_soa self_ns self_addr forbid_addr conv_glueless)) {
+	{ no strict 'refs'; $aref= [ @$sfx ]; }
+	@$aref or cfg_fail("failed to specify $sfx before zone")
+	    if $sfx =~ m/^self/;
+	$zone_cfg{$zone}{$sfx}= $aref;
     }
     $zone_cfg{$zone}{'output'}= $output;
     push @zone_cfg_list, $zone;
@@ -248,18 +252,16 @@ sub set_output($) {
 
 #-------------------- checking
 
-use vars qw($zone $cfg $warnings);
+use vars qw($zone $cfg $warnings %zone_warnings);
 $warnings= 0;
 
-sub progress ($) {
-    return if !$verbosity;
-    print "$_[0]\n";
+sub progress ($$) {
+    my ($minv,$m) = @_;
+    return if $verbosity < $minv;
+    print "$m\n";
 }
 
-sub verbose ($) {
-    return if $verbosity<2;
-    print "    $_[0]\n";
-}
+sub verbose ($) { progress(3, '    ' . $_[0]); }
 
 sub process_zones (@) {
     my (@zones) = @_;
@@ -272,7 +274,7 @@ sub process_zones (@) {
 	    's' => 'f',
 	    'servers' => [ ],
 	    };
-	progress(sprintf "%-40s %s", $zone, $$cfg{'style_p'});
+	progress(1, sprintf "%-20s %s", $zone, $$cfg{'style_p'});
 	if ($check && ($doall || $cfg->{'s'} !~ m/\?/)) {
 	    eval {
 		if ($localonly && $cfg->{'s'} =~ m/f/) {
@@ -289,32 +291,40 @@ sub process_zones (@) {
 	$output_contents{$$cfg{'output'}} .= zone_output()
 	    if $install;
     }
-    print STDERR "$quis: $warnings warnings\n" or die $!
-	if $warnings;
+    if ($warnings) {
+	printf STDERR ("%s: %d warning(s) in %d zone(s);".
+		       " %d zone(s) checked ok.\n",
+		       $quis,
+		       $warnings,
+		       scalar(keys %zone_warnings),
+		       scalar(@zones - keys %zone_warnings));
+    } else {
+	progress(1, sprintf "%d zone(s) checked ok", scalar @zones);
+    }
 }
 
 use vars qw(%delgs); # $delgs{$nameserver_list} = [ $whosaidandwhy ]
 use vars qw(%auths); # $auths{$nameserver_list} = [ $whosaidandwhy ]
 use vars qw(%glue);  # $glue{$name}{$addr_list} = [ $whosaidandwhy ]
-use vars qw(%soas);  # $soa{"$origin $serial"} = [ $whosaidandwhy ]
+use vars qw(%soas);  # $soa{"$serial $origin"} = [ $whosaidandwhy ]
 use vars qw(%addr_is_ok %warned);
 use vars qw($delg_to_us);
-use vars qw(@to_check); # ($addr,$whyask,$is_auth,$glueless_ok, ...)
-use vars qw(@to_check_soa); # ($addr,$whyask, ...)
+use vars qw(@to_check); # ($addr,$whyask,$name_if_auth,$glueless_ok, ...)
+use vars qw(@to_check_soa); # ($addr,$whyask,$name,$is_ns, ...)
 
 sub zone_warning ($$) {
     my ($w,$o) = @_;
     my ($wk);
 
-    $wk= $w;
-    $wk =~ s/,.*// if !$repeat;
-    return 0 if $warned{$w}{$wk}++;
+    return 0 if !$repeat && $warned{$w}++;
 
     $w =~ s/\n$//;
     $w =~ s,\n, // ,g;
 
+    $w .= " ($o)" if length $o;
     print STDERR "$zone: warning: $w\n" or die $!;
     $warnings++;
+    $zone_warnings{$zone}++;
     return 1;
 }
 
@@ -336,24 +346,27 @@ sub zone_reset() {
 
 sub zone_investigate() {
     my ($super_zone, @super_nsnames,
-	$super_ns, @super_ns_addrs, $s, $wa, $is_auth,
-	%nsrrset_checked, %soa_checked, $addr, $glueless_ok, $rcode);
+	$super_ns, @super_ns_addrs, $s, $wa, $name_if_auth,
+	%nsrrset_checked, %soa_checked, $addr, $glueless_ok,
+	$rcode, $name, $is_ns);
 
     $super_zone= $zone;
     for (;;) {
 	debug_trace("zone $zone superzone $super_zone");
 	$super_zone =~ s/^[^.]+\.// or die "no superzone ? ($super_zone)\n";
-	($rcode,@super_nsnames)= lookup($super_zone,'ns-','06');
+	($rcode,@super_nsnames)=
+	    lookup($super_zone,'ns-','06',"superzone search");
 	last if !$rcode;
     }
     for $super_ns (@super_nsnames) {
 	$super_ns= lc $super_ns;
-	($rcode,@super_ns_addrs)= lookup($super_ns,'a','0');
+	($rcode,@super_ns_addrs)=
+	    lookup($super_ns,'a','0',"published nameserver");
 	foreach $addr (@super_ns_addrs) {
 	    push @to_check,
 	         $addr,
 		 "$super_ns, server for $super_zone",
-		 0, 0;
+		 undef, 0;
 	}
     }
     for (;;) {
@@ -362,13 +375,14 @@ sub zone_investigate() {
 	# we might set nsrrset_checked due to a glueless_ok check,
 	# and then not check for gluefulness later.
 	debug_dump('@to_check @to_check_soa');
-	if (($addr,$wa,$is_auth,$glueless_ok,@to_check) = @to_check) {
-	    push @to_check_soa, $addr, $wa if $is_auth;
+	if (($addr,$wa,$name_if_auth,$glueless_ok,@to_check) = @to_check) {
+	    push @to_check_soa, $addr, $wa, $name_if_auth, 1,
+		if defined $name_if_auth;
 	    next if $nsrrset_checked{$addr}++;
-	    zone_check_nsrrset($addr, $wa, $is_auth, $glueless_ok);
-	} elsif (($addr,$wa,@to_check_soa) = @to_check_soa) {
+	    zone_check_nsrrset($addr, $wa, $name_if_auth, $glueless_ok);
+	} elsif (($addr,$wa,$name,$is_ns,@to_check_soa) = @to_check_soa) {
 	    next if $soa_checked{$addr}++;
-	    zone_check_soa($addr, $wa, "NS [$addr]");
+	    zone_check_soa($addr,$wa,$name,$is_ns);
 	} else {
 	    last;
 	}
@@ -376,16 +390,16 @@ sub zone_investigate() {
 }
 
 sub zone_check_nsrrset ($$$$) {
-    my ($uaddr,$wa, $is_auth, $glueless_ok) = @_;
+    my ($uaddr,$wa, $name_if_auth, $glueless_ok) = @_;
     my (@s, $s, %s2g, @glue, $glue, $delgs_or_auths, $wwn, $ww);
-    verbose("checking delegation by $ww");
     $ww= "[$uaddr] $wa";
+    verbose("checking delegation by $ww");
     dig(sub {
 	if ($dig_type eq 'ns' && $dig_owner eq $zone) {
 	    $s2g{lc $dig_rdata} = [ ];
 	} elsif ($dig_type eq 'a' && exists $s2g{$dig_owner}) {
 	    $wwn= "in glue from $ww";
-	    push @to_check, $dig_rdata, "$dig_owner, $wwn", 1, 0;
+	    push @to_check, $dig_rdata, "$dig_owner, $wwn", $dig_owner, 0;
 	    zone_server_addr($dig_rdata,$dig_owner,$wwn,"NS [$uaddr]",0);
 	    push @{ $s2g{$dig_owner} }, $dig_rdata;
 	}
@@ -395,42 +409,52 @@ sub zone_check_nsrrset ($$$$) {
 	zone_warning("unable to find NS RRset at [$uaddr]", $wa);
 	return;
     } elsif (keys %s2g == 1) {
-	zone_warning("only one nameserver",$ww);
+	zone_warning("only one nameserver ". (join '', keys %s2g),
+		     $ww);
     }
     @s= sort keys %s2g;
     foreach $s (@s) {
+	zone_ns_name($s,$ww);
 	@glue= @{ $s2g{$s} };
 	if (!@glue) {
-	    zone_warning("glueless NS $s,".($needglue<=1 ? " (eg)" : ""),
-			 $ww)
+	    zone_warning("glueless NS $s", $ww)
 		unless $glueless_ok || !$needglue ||
-		       grep { has_suffix_of($s,".$_"); } @conv_glueless;
+		       grep { has_suffix_of($s,".$_"); }
+			   @{ $cfg->{'conv_glueless'} };
 	    next;
 	}
 	$glue= join ' ', sort @glue;
 	push @{ $glue{$s}{$glue} }, $ww;
     }
     $s= join ' ', @s;
-    $delgs_or_auths= $is_auth ? \%auths : \%delgs;
+    $delgs_or_auths= defined($name_if_auth) ? \%auths : \%delgs;
     push @{ $delgs_or_auths->{$s} }, $ww;
 }
 
-sub zone_server_addr ($$$$$) {
-    my ($addr,$name,$ww,$wwq,$is_soa) = @_;
+sub zone_ns_name ($$) {
+    my ($name,$ww) = @_;
     my ($cg);
-    $addr_is_ok{$addr}= "$name ($wwq)"
-	if $is_soa || $cfg->{'s'} =~ m/u/;
-    foreach $cg (@conv_glueless) {
-	next unless has_suffix_of(".$name",".$cg");
-	zone_warning("nameserver [$addr] $name in serverless-glueless".
+    $delg_to_us=1 if grep { $name eq $_ } @{ $cfg->{'self_ns'} };
+    foreach $cg (@{ $cfg->{'conv_glueless'} }) {
+	zone_warning("nameserver $name in serverless-glueless".
 		     " namespace area $cg",
-		     $ww);
+		     $ww)
+	    if has_suffix_of(".$name",".$cg");
     }
-    zone_warning("configured as stealth but we [$addr] $name are published",
+    zone_warning("published server, as $name, but configured as stealth",
 		 $ww)
-	if $cfg->{'s'} =~ m/u/ && grep { $_ eq $addr } @self_addr;
+	if $cfg->{'s'} =~ m/u/ &&
+	   grep { $_ eq $name }
+               @{ $cfg->{'self_ns'} }, @{ $cfg->{'self_soa'} };
+}
+
+sub zone_server_addr ($$$$$) {
+    my ($addr,$name,$ww,$wwq,$is_soa) = @_;
+    debug_trace("zone_server_addr ".join '|',@_);
+    $addr_is_ok{$addr}= "$name ($wwq)"
+	if $is_soa || $cfg->{'s'} =~ m/u/;
     zone_warning("forbidden nameserver address [$addr] $name",$ww)
-	if grep { $_ eq $addr } @forbid_addr;
+	if grep { $_ eq $addr } @{ $cfg->{'forbid_addr'} };
 
     my ($name_is_self, $addr_is_self);
     $name_is_self= grep { $_ eq $name }
@@ -438,19 +462,26 @@ sub zone_server_addr ($$$$$) {
     $addr_is_self= grep { $_ eq $addr }
         @{ $cfg->{'self_addr'} };
     if ($name_is_self && !$addr_is_self) {
-	zone_warning("our name $name with wrong address [$addr]",$ww);
-    } elsif (!$name_is_self && $addr_is_self) {
-	zone_warning(($is_soa ? "SOA ORIGIN maps to" : "referral to").
-		     " us [$addr] with wrong name $name",
+	zone_warning("our $name supplied with wrong address [$addr]", $ww);
+    }
+    if (!$name_is_self && $addr_is_self) {
+	zone_warning("we [$addr] are named in ".
+		     ($is_soa ? "SOA" : "NS").
+		     " by wrong name $name",
 		     $ww);
     }
-    $delg_to_us=1 if $name_is_self;
+    if (!$name_is_self && !$addr_is_self &&
+	$is_soa && $cfg->{'s'} =~ m/p/) {
+	zone_warning("SOA ORIGIN $name is not us (".
+		     (join ' ', @{ $cfg->{'self_soa'} }).")", $ww);
+    }
+    $delg_to_us=1 if $addr_is_self && !$is_soa;
 }
 
-sub zone_check_soa ($$$) {
-    my ($uaddr,$wa,$waq) = @_;
-    my ($lame,$origin,$got,$rcode,@soa_addrs,$soa_addr,$ww,$wwn);
-    verbose("checking service at [$uaddr] $waq");
+sub zone_check_soa ($$$$) {
+    my ($uaddr,$wa,$name,$is_ns) = @_;
+    my ($lame,$serial,$origin,$got,$rcode,@soa_addrs,$soa_addr,$ww,$wwn);
+    verbose("checking service at [$uaddr] $name");
     $lame= 'dead or lame';
     $ww= "[$uaddr] $wa";
     dig(sub {
@@ -459,19 +490,21 @@ sub zone_check_soa ($$$) {
 	} elsif ($dig_type eq 'soa' && $dig_owner eq $zone && !$lame) {
 	    die "several SOAs ? $ww" if defined $origin;
 	    $got= $dig_rdata;
-	    $got =~ m/^(\S+) \d+/ or die "$got ?";
-	    $origin= $1;
+	    $got =~ m/^(\d+) (\S+)$/ or die "$got ?";
+	    ($serial,$origin) = ($1,$2);
 	}
     },
 	     $zone,'soa',$uaddr);
     $lame= 'broken' if !$lame && !defined $origin;
     if ($lame) { zone_warning("$lame server [$uaddr]",$wa); return; }
+    progress(2, sprintf "%-22s %40s has %s%s",
+	     $zone, $name, $serial, $is_ns ? '' : '*');
     push @{ $soas{$got} }, $ww;
-    ($rcode,@soa_addrs)= lookup($origin,'a','0');
+    ($rcode,@soa_addrs)= lookup($origin,'a','0',"SOA ORIGIN");
     $wwn= "SOA ORIGIN from $ww";
     foreach $soa_addr (@soa_addrs) {
 	zone_server_addr($soa_addr,$origin,$wwn,"SOA [$uaddr]",1);
-	push @to_check, $soa_addr, "$origin, $wwn";
+	push @to_check, $soa_addr, "$origin, $wwn", $origin, 1;
     }
 }
 
@@ -483,23 +516,12 @@ sub zone_consistency() {
     foreach $h (keys %glue) {
 	zone_consistency_set("glue for $h", $glue{$h});
     }
-    zone_consistency_set("SOA ORIGIN and SERIAL",\%soas);
+    zone_consistency_set("serial number and/or SOA ORIGIN",\%soas);
     $self_soa= $cfg->{'self_soa'};
-    if ($cfg->{'s'} =~ m/p/) {
-	foreach $org_ser (keys %soas) {
-	    $org_ser =~ m/^(\S+) \d+$/ or die "$org_ser ?";
-	    $origin= $1;
-	    next if grep { $_ eq $origin } @$self_soa;
-	    foreach $wa (@{ $soas{$org_ser} }) {
-		zone_warning("SOA ORIGIN $origin is not our name (@$self_soa)",
-			     $wa);
-	    }
-	}
-    }
 }
 
 sub zone_servers_ok () {
-    my ($showok);
+    my ($showok,%fs);
     if (%addr_is_ok) {
 	$showok= 0;
 	foreach $a (@{ $cfg->{'servers'} }) {
@@ -516,6 +538,8 @@ sub zone_servers_ok () {
     if ($cfg->{'s'} =~ m/s/ && !$delg_to_us) {
 	zone_warning("we are supposedly published secondary,".
 		     " but not listed as a nameserver",'');
+	map { $fs{$_}=1 } keys(%delgs), keys(%auths);
+	zone_warnmore("servers are: ". join ' ', sort keys %fs);
     }
 }
 
@@ -538,19 +562,23 @@ sub zone_check_local () {
 sub zone_servers_simplefind () {
     my ($rcode,@nsnames,$ns,@soas,$origin);
 
-    ($rcode,@nsnames)= lookup($zone,'ns-','0');
-    foreach $ns (@nsnames) { zone_server_simple($ns,'NS',0); }
+    ($rcode,@nsnames)= lookup($zone,'ns-','0',"zone's servers");
+    foreach $ns (@nsnames) {
+	zone_ns_name($ns,"NS");
+	zone_server_simple($ns,'NS',0);
+    }
 
-    ($rcode,@soas)= lookup($zone,'soa','0');
+    ($rcode,@soas)= lookup($zone,'soa','0',"SOA ORIGIN");
     die "multiple SOA RRs in set!  @soas ?" if @soas!=1;
     $soas[0] =~ m/^(\S+)\s/ or die "SOA ? $_";
-    zone_server_simple(domain_canon($1),'SOA',1);
+    zone_server_simple(domain_canon($1,"lookup $zone SOA"),'SOA',1);
 }
 
 sub zone_server_simple ($$$) {
     my ($name,$ww,$is_soa) = @_;
     my ($rcode,@addrs,$addr);
-    ($rcode,@addrs)= lookup($name,'a','0');
+    ($rcode,@addrs)= lookup($name,'a','0', "server - ".
+			    ($is_soa ? "SOA ORIGIN" : "NS"));
     foreach $addr (@addrs) { zone_server_addr($addr,$name,$ww,$ww,$is_soa); }
 }
 
@@ -633,14 +661,16 @@ sub debug_trace ($) {
 }
 
 sub has_suffix_of ($$) {
-    my ($whole,$suffix);
+    my ($whole,$suffix) = @_;
+    debug_trace("has_suffix_of $whole $suffix");
     return 0 if length $whole < length $suffix;
     return 0 if substr($whole, length($whole) - length($suffix)) ne $suffix;
+    debug_trace("has_suffix_of $whole $suffix YES");
     return 1;
 }
 
-sub lookup ($$$) {
-    my ($domain,$type,$okrcodes) = @_;
+sub lookup ($$$$) {
+    my ($domain,$type,$okrcodes,$w) = @_;
     my ($c,$h,@result);
     debug_trace("lookup ==> (->$okrcodes) $domain $type");
     $h= new IO::Handle;
@@ -655,17 +685,16 @@ sub lookup ($$$) {
     $h->error and die "$quis: read from adnshost:\n $!\n";
     chomp @result;
     $!=0; $h->close;
-    die "$quis: lookup -t$type $domain $okrcodes failed $? $! @result\n"
+    die "$quis: lookup -t$type $domain $okrcodes ($w) failed $? $! @result\n"
 	if $! or $?&255 or $?>1536 or index($okrcodes,$?>>8)<0;
     debug_trace("lookup <== $? @result");
     return ($?,@result);
 }
 
-
 sub dig (&$$$) {
     my ($eachrr, $qowner,$qtype,$qaddr) = @_;
     # also pseudo-rr with type `flags:'
-    my ($h,$inmid,$irdata,$c);
+    my ($h,$inmid,$irdata,$c,$digwhy);
     local ($_);
 
     debug_trace("dig ==> \@$qaddr $qowner $qtype");
@@ -694,6 +723,7 @@ sub dig (&$$$) {
 	    s/$/ \(/ unless s/\s*\)\s*$//;
 	}
 	if (s/\s*\(\s*$//) { $inmid= $_; next; }
+	$digwhy= "dig $qowner $qtype $qaddr \`$_'";
 	if (m/^\;\; flags\:( [-0-9a-z ]+)\;/) {
 	    $dig_owner=''; $dig_type='flags:'; $dig_rdata= "$1 ";
 	    debug_trace("dig  f: $dig_rdata");
@@ -701,17 +731,17 @@ sub dig (&$$$) {
 	} elsif (m/^\;/) {
 	} elsif (!m/\S/) {
 	} elsif (m/^([-.0-9a-z]+)\s+\d\w+\s+in\s+([a-z]+)\s+(\S.*)/i) {
-	    $dig_owner=domain_canon($1); $dig_type=lc $2; $irdata=$3;
+	    $dig_owner=domain_canon($1,$digwhy); $dig_type=lc $2; $irdata=$3;
 	    if ($dig_type eq 'a') {
 		$irdata =~ m/^[.0-9]+$/ or die "$irdata ?";
 		$dig_rdata= $&;
 	    } elsif ($dig_type eq 'ns') {
 		$irdata =~ m/^[-.0-9a-z]+$/i or die "bad nameserver $irdata ?";
-		$dig_rdata= domain_canon($irdata);
+		$dig_rdata= domain_canon($irdata,$digwhy);
 	    } elsif ($dig_type eq 'soa') {
 		$irdata =~ m/^([-.0-9a-z]+)\s+.*\s+(\d+)(?:\s+\d\w+){4}$/i
 		    or die "bad SOA $irdata ?";
-		$dig_rdata= domain_canon($1).' '.$2;
+		$dig_rdata= $2.' '.domain_canon($1,$digwhy);
 	    } else {
 		debug_trace("ignoring uknown RR type $dig_type");
 		next;
@@ -726,9 +756,10 @@ sub dig (&$$$) {
     debug_trace("dig <== gave $?");
 }
 
-sub domain_canon ($) {
-    local ($_) = @_;
-    s/(.)\.$/$1/;
-    die "domain $_ ?" unless m/^[0-9a-z]/i;
-    return lc $_;
+sub domain_canon ($$) {
+    my ($i,$w) = @_;
+    $i =~ s/(.)\.$/$1/;
+    return '.' if $i eq '.';
+    die "domain $i ($w) ?" unless $i =~ m/^[0-9a-z]/i;
+    return lc $i;
 }