--- loncom/lonnet/perl/lonnet.pm	2007/03/02 23:17:40	1.838
+++ loncom/lonnet/perl/lonnet.pm	2007/03/30 18:18:43	1.855
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.838 2007/03/02 23:17:40 albertel Exp $
+# $Id: lonnet.pm,v 1.855 2007/03/30 18:18:43 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -35,12 +35,10 @@ use HTTP::Headers;
 use HTTP::Date;
 # use Date::Parse;
 use vars 
-qw(%perlvar %badServerCache %iphost %spareid %hostdom 
-   %libserv %pr %prp $memcache %packagetab 
+qw(%perlvar %badServerCache %spareid 
+   %pr %prp $memcache %packagetab 
    %courselogs %accesshash %userrolehash %domainrolehash $processmarker $dumpcount 
    %coursedombuf %coursenumbuf %coursehombuf %coursedescrbuf %courseinstcodebuf %courseownerbuf %coursetypebuf
-   %domaindescription %domain_auth_def %domain_auth_arg_def 
-   %domain_lang_def %domain_city %domain_longi %domain_lati %domain_primary
    $tmpdir $_64bit %env);
 
 use IO::Socket;
@@ -146,6 +144,20 @@ sub logperm {
     return 1;
 }
 
+sub create_connection {
+    my ($hostname,$lonid) = @_;
+    my $client=IO::Socket::UNIX->new(Peer    => $perlvar{'lonSockCreate'},
+				     Type    => SOCK_STREAM,
+				     Timeout => 10);
+    return 0 if (!$client);
+    print $client (join(':',$hostname,$lonid,&machine_ids($lonid))."\n");
+    my $result = <$client>;
+    chomp($result);
+    return 1 if ($result eq 'done');
+    return 0;
+}
+
+
 # -------------------------------------------------- Non-critical communication
 sub subreply {
     my ($cmd,$server)=@_;
@@ -172,8 +184,10 @@ sub subreply {
 				      Timeout => 10);
 	if($client) {
 	    last;		# Connected!
+	} else {
+	    &create_connection(&hostname($server),$server);
 	}
-	sleep(1);		# Try again later if failed connection.
+        sleep(1);		# Try again later if failed connection.
     }
     my $answer;
     if ($client) {
@@ -640,19 +654,19 @@ sub homeserver {
     my $index="$uname:$udom";
 
     if (exists($homecache{$index})) { return $homecache{$index}; }
-    my $tryserver;
-    foreach $tryserver (keys %libserv) {
+
+    my %servers = &get_servers($udom,'library');
+    foreach my $tryserver (keys(%servers)) {
         next if ($ignoreBadCache ne 'true' && 
 		 exists($badServerCache{$tryserver}));
-	if ($hostdom{$tryserver} eq $udom) {
-           my $answer=reply("home:$udom:$uname",$tryserver);
-           if ($answer eq 'found') {
-               delete($badServerCache{$tryserver}); 
-	       return $homecache{$index}=$tryserver;
-           } elsif ($answer eq 'no_host') {
-	       $badServerCache{$tryserver}=1;
-           }
-       }
+
+	my $answer=reply("home:$udom:$uname",$tryserver);
+	if ($answer eq 'found') {
+	    delete($badServerCache{$tryserver}); 
+	    return $homecache{$index}=$tryserver;
+	} elsif ($answer eq 'no_host') {
+	    $badServerCache{$tryserver}=1;
+	}
     }    
     return 'no_host';
 }
@@ -663,24 +677,22 @@ sub idget {
     my ($udom,@ids)=@_;
     my %returnhash=();
     
-    my $tryserver;
-    foreach $tryserver (keys %libserv) {
-       if ($hostdom{$tryserver} eq $udom) {
-	  my $idlist=join('&',@ids);
-          $idlist=~tr/A-Z/a-z/; 
-	  my $reply=&reply("idget:$udom:".$idlist,$tryserver);
-          my @answer=();
-          if (($reply ne 'con_lost') && ($reply!~/^error\:/)) {
-	      @answer=split(/\&/,$reply);
-          }                    ;
-          my $i;
-          for ($i=0;$i<=$#ids;$i++) {
-              if ($answer[$i]) {
-		  $returnhash{$ids[$i]}=$answer[$i];
-              } 
-          }
-       }
-    }    
+    my %servers = &get_servers($udom,'library');
+    foreach my $tryserver (keys(%servers)) {
+	my $idlist=join('&',@ids);
+	$idlist=~tr/A-Z/a-z/; 
+	my $reply=&reply("idget:$udom:".$idlist,$tryserver);
+	my @answer=();
+	if (($reply ne 'con_lost') && ($reply!~/^error\:/)) {
+	    @answer=split(/\&/,$reply);
+	}                    ;
+	my $i;
+	for ($i=0;$i<=$#ids;$i++) {
+	    if ($answer[$i]) {
+		$returnhash{$ids[$i]}=$answer[$i];
+	    } 
+	}
+    } 
     return %returnhash;
 }
 
@@ -729,8 +741,8 @@ sub get_dom {
     }
     $items=~s/\&$//;
     if (!$udom) { $udom=$env{'user.domain'}; }
-    if (exists($domain_primary{$udom})) {
-        my $uhome=$domain_primary{$udom};
+    if (defined(&domain($udom,'primary'))) {
+        my $uhome=&domain($udom,'primary');
         my $rep=&reply("getdom:$udom:$namespace:$items",$uhome);
         my @pairs=split(/\&/,$rep);
         if ( $#pairs==0 && $pairs[0] =~ /^(con_lost|error|no_such_host)/i) {
@@ -753,8 +765,8 @@ sub get_dom {
 sub put_dom {
     my ($namespace,$storehash,$udom)=@_;
     if (!$udom) { $udom=$env{'user.domain'}; }
-    if (exists($domain_primary{$udom})) {
-        my $uhome=$domain_primary{$udom};
+    if (defined(&domain($udom,'primary'))) {
+        my $uhome=&domain($udom,'primary');
         my $items='';
         foreach my $item (keys(%$storehash)) {
             $items.=&escape($item).'='.&freeze_escape($$storehash{$item}).'&';
@@ -769,8 +781,8 @@ sub put_dom {
 sub retrieve_inst_usertypes {
     my ($udom) = @_;
     my (%returnhash,@order);
-    if (exists($domain_primary{$udom})) {
-        my $uhome=$domain_primary{$udom};
+    if (defined(&domain($udom,'primary'))) {
+        my $uhome=&domain($udom,'primary');
         my $rep=&reply("inst_usertypes:$udom",$uhome);
         my ($hashitems,$orderitems) = split(/:/,$rep); 
         my @pairs=split(/\&/,$hashitems);
@@ -1014,10 +1026,16 @@ my %remembered;
 my %accessed;
 my $kicks=0;
 my $hits=0;
+sub make_key {
+    my ($name,$id) = @_;
+    if (length($id) > 200) { $id=length($id).':'.&Digest::MD5::md5_hex($id); }
+    return &escape($name.':'.$id);
+}
+
 sub devalidate_cache_new {
     my ($name,$id,$debug) = @_;
     if ($debug) { &Apache::lonnet::logthis("deleting $name:$id"); }
-    $id=&escape($name.':'.$id);
+    $id=&make_key($name,$id);
     $memcache->delete($id);
     delete($remembered{$id});
     delete($accessed{$id});
@@ -1025,7 +1043,7 @@ sub devalidate_cache_new {
 
 sub is_cached_new {
     my ($name,$id,$debug) = @_;
-    $id=&escape($name.':'.$id);
+    $id=&make_key($name,$id);
     if (exists($remembered{$id})) {
 	if ($debug) { &Apache::lonnet::logthis("Earyl return $id of $remembered{$id} "); }
 	$accessed{$id}=[&gettimeofday()];
@@ -1048,7 +1066,7 @@ sub is_cached_new {
 
 sub do_cache_new {
     my ($name,$id,$value,$time,$debug) = @_;
-    $id=&escape($name.':'.$id);
+    $id=&make_key($name,$id);
     my $setvalue=$value;
     if (!defined($setvalue)) {
 	$setvalue='__undef__';
@@ -1843,8 +1861,9 @@ sub flushcourselogs {
 # Write course id database (reverse lookup) to homeserver of courses 
 # Is used in pickcourse
 #
-    foreach my $crsid (keys(%courseidbuffer)) {
-        &courseidput($hostdom{$crsid},$courseidbuffer{$crsid},$crsid);
+    foreach my $crs_home (keys(%courseidbuffer)) {
+        &courseidput(&host_domain($crs_home),$courseidbuffer{$crs_home},
+		     $crs_home);
     }
 #
 # File accesses
@@ -1911,13 +1930,12 @@ sub flushcourselogs {
         delete $domainrolehash{$entry};
     }
     foreach my $dom (keys(%domrolebuffer)) {
-        foreach my $tryserver (keys %libserv) {
-            if ($hostdom{$tryserver} eq $dom) {
-                unless (&reply('domroleput:'.$dom.':'.
-                  $domrolebuffer{$dom},$tryserver) eq 'ok') {
-                    &logthis('Put of domain roles failed for '.$dom.' and  '.$tryserver);
-                }
-            }
+	my %servers = &get_servers($dom,'library');
+	foreach my $tryserver (keys(%servers)) {
+	    unless (&reply('domroleput:'.$dom.':'.
+			   $domrolebuffer{$dom},$tryserver) eq 'ok') {
+		&logthis('Put of domain roles failed for '.$dom.' and  '.$tryserver);
+	    }
         }
     }
     $dumpcount++;
@@ -2099,7 +2117,7 @@ sub get_my_roles {
 
 sub postannounce {
     my ($server,$text)=@_;
-    unless (&allowed('psa',$hostdom{$server})) { return 'refused'; }
+    unless (&allowed('psa',&host_domain($server))) { return 'refused'; }
     unless ($text=~/\w/) { $text=''; }
     return &reply('setannounce:'.&escape($text),$server);
 }
@@ -2135,11 +2153,16 @@ sub courseiddump {
     my ($domfilter,$descfilter,$sincefilter,$instcodefilter,$ownerfilter,$coursefilter,$hostidflag,$hostidref,$typefilter,$regexp_ok)=@_;
     my %returnhash=();
     unless ($domfilter) { $domfilter=''; }
-    foreach my $tryserver (keys %libserv) {
-        if ( ($hostidflag == 1 && grep/^$tryserver$/,@{$hostidref}) || (!defined($hostidflag)) ) {
-	    if ((!$domfilter) || ($hostdom{$tryserver} eq $domfilter)) {
+    my %libserv = &all_library();
+    foreach my $tryserver (keys(%libserv)) {
+        if ( (  $hostidflag == 1 
+	        && grep(/^\Q$tryserver\E$/,@{$hostidref}) ) 
+	     || (!defined($hostidflag)) ) {
+
+	    if ($domfilter eq ''
+		|| (&host_domain($tryserver) eq $domfilter)) {
 	        foreach my $line (
-                 split(/\&/,&reply('courseiddump:'.$hostdom{$tryserver}.':'.
+                 split(/\&/,&reply('courseiddump:'.&host_domain($tryserver).':'.
 			       $sincefilter.':'.&escape($descfilter).':'.
                                &escape($instcodefilter).':'.&escape($ownerfilter).':'.&escape($coursefilter).':'.&escape($typefilter).':'.&escape($regexp_ok),
                                $tryserver))) {
@@ -2167,12 +2190,13 @@ sub dcmailput {
 sub dcmaildump {
     my ($dom,$startdate,$enddate,$senders) = @_;
     my %returnhash=();
-    if (exists($domain_primary{$dom})) {
+
+    if (defined(&domain($dom,'primary'))) {
         my $cmd='dcmaildump:'.$dom.':'.&escape($startdate).':'.
                                                          &escape($enddate).':';
 	my @esc_senders=map { &escape($_)} @$senders;
 	$cmd.=&escape(join('&',@esc_senders));
-	foreach my $line (split(/\&/,&reply($cmd,$domain_primary{$dom}))) {
+	foreach my $line (split(/\&/,&reply($cmd,&domain($dom,'primary')))) {
             my ($key,$value) = split(/\=/,$line,2);
             if (($key) && ($value)) {
                 $returnhash{&unescape($key)} = &unescape($value);
@@ -2193,19 +2217,19 @@ sub get_domain_roles {
     }
     my $rolelist = join(':',@{$roles});
     my %personnel = ();
-    foreach my $tryserver (keys(%libserv)) {
-        if ($hostdom{$tryserver} eq $dom) {
-            %{$personnel{$tryserver}}=();
-            foreach my $line (
-                split(/\&/,&reply('domrolesdump:'.$dom.':'.
-                   &escape($startdate).':'.&escape($enddate).':'.
-                   &escape($rolelist), $tryserver))) {
-                my ($key,$value) = split(/\=/,$line,2);
-                if (($key) && ($value)) {
-                    $personnel{$tryserver}{&unescape($key)} = &unescape($value);
-                }
-            }
-        }
+
+    my %servers = &get_servers($dom,'library');
+    foreach my $tryserver (keys(%servers)) {
+	%{$personnel{$tryserver}}=();
+	foreach my $line (split(/\&/,&reply('domrolesdump:'.$dom.':'.
+					    &escape($startdate).':'.
+					    &escape($enddate).':'.
+					    &escape($rolelist), $tryserver))) {
+	    my ($key,$value) = split(/\=/,$line,2);
+	    if (($key) && ($value)) {
+		$personnel{$tryserver}{&unescape($key)} = &unescape($value);
+	    }
+	}
     }
     return %personnel;
 }
@@ -4172,6 +4196,7 @@ sub definerole {
 sub metadata_query {
     my ($query,$custom,$customshow,$server_array)=@_;
     my %rhash;
+    my %libserv = &all_library();
     my @server_list = (defined($server_array) ? @$server_array
                                               : keys(%libserv) );
     for my $server (@server_list) {
@@ -4458,12 +4483,11 @@ sub auto_instcode_format {
     my $courses = '';
     my @homeservers;
     if ($caller eq 'global') {
-        foreach my $tryserver (keys(%libserv)) {
-            if ($hostdom{$tryserver} eq $codedom) {
-                if (!grep(/^\Q$tryserver\E$/,@homeservers)) {
-                    push(@homeservers,$tryserver);
-                }
-            }
+	my %servers = &get_servers($codedom,'library');
+	foreach my $tryserver (keys(%servers)) {
+	    if (!grep(/^\Q$tryserver\E$/,@homeservers)) {
+		push(@homeservers,$tryserver);
+	    }
         }
     } else {
         push(@homeservers,&homeserver($caller,$codedom));
@@ -4497,35 +4521,31 @@ sub auto_instcode_format {
 sub auto_instcode_defaults {
     my ($domain,$returnhash,$code_order) = @_;
     my @homeservers;
-    foreach my $tryserver (keys(%libserv)) {
-        if ($hostdom{$tryserver} eq $domain) {
-            if (!grep(/^\Q$tryserver\E$/,@homeservers)) {
-                push(@homeservers,$tryserver);
-            }
-        }
+
+    my %servers = &get_servers($domain,'library');
+    foreach my $tryserver (keys(%servers)) {
+	if (!grep(/^\Q$tryserver\E$/,@homeservers)) {
+	    push(@homeservers,$tryserver);
+	}
     }
-    my $ok_response = 0;
+
     my $response;
-    while (@homeservers > 0 && $ok_response == 0) {
-        my $server = shift(@homeservers);
+    foreach my $server (@homeservers) {
         $response=&reply('autoinstcodedefaults:'.$domain,$server);
-        if ($response !~ /(con_lost|error|no_such_host|refused)/) {
-            foreach my $pair (split(/\&/,$response)) {
-                my ($name,$value)=split(/\=/,$pair);
-                if ($name eq 'code_order') {
-                    @{$code_order} = split(/\&/,&unescape($value));
-                } else {
-                    $returnhash->{&unescape($name)}=&unescape($value);
-                }
-            }
-            $ok_response = 1;
-        }
-    }
-    if ($ok_response) {
-        return 'ok';
-    } else {
-        return $response;
+        next if ($response =~ /(con_lost|error|no_such_host|refused)/);
+	
+	foreach my $pair (split(/\&/,$response)) {
+	    my ($name,$value)=split(/\=/,$pair);
+	    if ($name eq 'code_order') {
+		@{$code_order} = split(/\&/,&unescape($value));
+	    } else {
+		$returnhash->{&unescape($name)}=&unescape($value);
+	    }
+	}
+	return 'ok';
     }
+
+    return $response;
 } 
 
 sub auto_validate_class_sec {
@@ -4818,21 +4838,19 @@ sub modifyuser {
     if (($uhome eq 'no_host') && 
 	(($umode && $upass) || ($umode eq 'localauth'))) {
         my $unhome='';
-        if (defined($desiredhome) && $hostdom{$desiredhome} eq $udom) { 
+        if (defined($desiredhome) && &host_domain($desiredhome) eq $udom) { 
             $unhome = $desiredhome;
 	} elsif($env{'course.'.$env{'request.course.id'}.'.domain'} eq $udom) {
 	    $unhome=$env{'course.'.$env{'request.course.id'}.'.home'};
         } else { # load balancing routine for determining $unhome
-            my $tryserver;
             my $loadm=10000000;
-            foreach $tryserver (keys %libserv) {
-	       if ($hostdom{$tryserver} eq $udom) {
-                  my $answer=reply('load',$tryserver);
-                  if (($answer=~/\d+/) && ($answer<$loadm)) {
-		      $loadm=$answer;
-                      $unhome=$tryserver;
-                  }
-	       }
+	    my %servers = &get_servers($udom,'library');
+	    foreach my $tryserver (keys(%servers)) {
+		my $answer=reply('load',$tryserver);
+		if (($answer=~/\d+/) && ($answer<$loadm)) {
+		    $loadm=$answer;
+		    $unhome=$tryserver;
+		}
 	    }
         }
         if (($unhome eq '') || ($unhome eq 'no_host')) {
@@ -5047,7 +5065,7 @@ sub createcourse {
    }
 # ------------------------------------------------ Check supplied server name
     $course_server = $env{'user.homeserver'} if (! defined($course_server));
-    if (! exists($libserv{$course_server})) {
+    if (! &is_library($course_server)) {
         return 'error:bad server name '.$course_server;
     }
 # ------------------------------------------------------------- Make the course
@@ -5580,28 +5598,27 @@ sub dirlist {
             return @listing_results;
         } elsif(!defined($alternateDirectoryRoot)) {
             my %allusers;
-            foreach my $tryserver (keys(%libserv)) {
-                if($hostdom{$tryserver} eq $udom) {
-                    my $listing = &reply('ls2:'.$perlvar{'lonDocRoot'}.'/res/'.
-					 $udom, $tryserver);
-                    my @listing_results;
-                    if ($listing eq 'unknown_cmd') {
-                        $listing = &reply('ls:'.$perlvar{'lonDocRoot'}.'/res/'.
-					  $udom, $tryserver);
-                        @listing_results = split(/:/,$listing);
-                    } else {
-                        @listing_results =
-                            map { &unescape($_); } split(/:/,$listing);
-                    }
-                    if ($listing_results[0] ne 'no_such_dir' && 
-                        $listing_results[0] ne 'empty'       &&
-                        $listing_results[0] ne 'con_lost') {
-                        foreach my $line (@listing_results) {
-                            my ($entry) = split(/&/,$line,2);
-                            $allusers{$entry} = 1;
-                        }
-                    }
-                }
+	    my %servers = &get_servers($udom,'library');
+	    foreach my $tryserver (keys(%servers)) {
+		my $listing = &reply('ls2:'.$perlvar{'lonDocRoot'}.'/res/'.
+				     $udom, $tryserver);
+		my @listing_results;
+		if ($listing eq 'unknown_cmd') {
+		    $listing = &reply('ls:'.$perlvar{'lonDocRoot'}.'/res/'.
+				      $udom, $tryserver);
+		    @listing_results = split(/:/,$listing);
+		} else {
+		    @listing_results =
+			map { &unescape($_); } split(/:/,$listing);
+		}
+		if ($listing_results[0] ne 'no_such_dir' && 
+		    $listing_results[0] ne 'empty'       &&
+		    $listing_results[0] ne 'con_lost') {
+		    foreach my $line (@listing_results) {
+			my ($entry) = split(/&/,$line,2);
+			$allusers{$entry} = 1;
+		    }
+		}
             }
             my $alluserstr='';
             foreach my $user (sort(keys(%allusers))) {
@@ -5613,18 +5630,12 @@ sub dirlist {
             return ('missing user name');
         }
     } elsif(!defined($alternateDirectoryRoot)) {
-        my $tryserver;
-        my %alldom=();
-        foreach $tryserver (keys(%libserv)) {
-            $alldom{$hostdom{$tryserver}}=1;
-        }
-        my $alldomstr='';
-        foreach my $domain (sort(keys(%alldom))) {
-            $alldomstr.=$perlvar{'lonDocRoot'}.'/res/'.$domain.'/&domain:';
-        }
-        $alldomstr=~s/:$//;
-        return split(/:/,$alldomstr);       
-    } else {
+        my @all_domains = sort(&all_domains());
+         foreach my $domain (@all_domains) {
+             $domain = $perlvar{'lonDocRoot'}.'/res/'.$domain.'/&domain';
+         }
+         return @all_domains;
+     } else {
         return ('missing domain');
     }
 }
@@ -6187,7 +6198,8 @@ sub packages_tab_default {
 	    $do_default=1;
 	} elsif ($pack_type eq 'extension') {
 	    push(@extension,[$package,$pack_type,$pack_part]);
-	} else {
+	} elsif ($pack_part eq $part) {
+	    # only look at packages defaults for packages that this id is
 	    push(@specifics,[$package,$pack_type,$pack_part]);
 	}
     }
@@ -7414,20 +7426,29 @@ sub hreflocation {
 }
 
 sub current_machine_domains {
-    my $hostname=&hostname($perlvar{'lonHostID'});
+    return &machine_domains(&hostname($perlvar{'lonHostID'}));
+}
+
+sub machine_domains {
+    my ($hostname) = @_;
     my @domains;
     my %hostname = &all_hostnames();
     while( my($id, $name) = each(%hostname)) {
 #	&logthis("-$id-$name-$hostname-");
 	if ($hostname eq $name) {
-	    push(@domains,$hostdom{$id});
+	    push(@domains,&host_domain($id));
 	}
     }
     return @domains;
 }
 
 sub current_machine_ids {
-    my $hostname=&hostname($perlvar{'lonHostID'});
+    return &machine_ids(&hostname($perlvar{'lonHostID'}));
+}
+
+sub machine_ids {
+    my ($hostname) = @_;
+    $hostname ||= &hostname($perlvar{'lonHostID'});
     my @ids;
     my %hostname = &all_hostnames();
     while( my($id, $name) = each(%hostname)) {
@@ -7575,86 +7596,202 @@ BEGIN {
     %perlvar = (%perlvar,%{$configvars});
 }
 
+sub get_dns {
+    my ($url,$func) = @_;
+    open(my $config,"<$perlvar{'lonTabDir'}/hosts.tab");
+    foreach my $dns (<$config>) {
+	next if ($dns !~ /^\^(\S*)/x);
+	$dns = $1;
+	my $ua=new LWP::UserAgent;
+	my $request=new HTTP::Request('GET',"http://$dns$url");
+	my $response=$ua->request($request);
+	next if ($response->is_error());
+	my @content = split("\n",$response->content);
+	&$func(\@content);
+    }
+    close($config);
+}
 # ------------------------------------------------------------ Read domain file
 {
-    %domaindescription = ();
-    %domain_auth_def = ();
-    %domain_auth_arg_def = ();
-    my $fh;
-    if (open($fh,"<".$Apache::lonnet::perlvar{'lonTabDir'}.'/domain.tab')) {
-	while (my $line = <$fh>) {
-           next if ($line =~ /^(\#|\s*$)/);
-#           next if /^\#/;
-           chomp $line;
-           my ($domain, $domain_description, $def_auth, $def_auth_arg,
-	       $def_lang, $city, $longi, $lati, $primary) = split(/:/,$line,9);
-	   $domain_auth_def{$domain}=$def_auth;
-           $domain_auth_arg_def{$domain}=$def_auth_arg;
-	   $domaindescription{$domain}=$domain_description;
-	   $domain_lang_def{$domain}=$def_lang;
-	   $domain_city{$domain}=$city;
-	   $domain_longi{$domain}=$longi;
-	   $domain_lati{$domain}=$lati;
-           $domain_primary{$domain}=$primary;
+    my $loaded;
+    my %domain;
 
- #         &logthis("Domain.tab: $domain, $domain_auth_def{$domain}, $domain_auth_arg_def{$domain},$domaindescription{$domain}");
-#          &logthis("Domain.tab: $domain ".$domaindescription{$domain} );
+    sub parse_domain_tab {
+	my ($lines) = @_;
+	foreach my $line (@$lines) {
+	    next if ($line =~ /^(\#|\s*$ )/x);
+
+	    chomp($line);
+	    my ($name,@elements) = split(/:/,$line,9);
+	    my %this_domain;
+	    foreach my $field ('description', 'auth_def', 'auth_arg_def',
+			       'lang_def', 'city', 'longi', 'lati',
+			       'primary') {
+		$this_domain{$field} = shift(@elements);
+	    }
+	    $domain{$name} = \%this_domain;
+	    &logthis("Domain.tab: $name ".$domain{$name}{'description'} );
 	}
     }
-    close ($fh);
+    
+    sub load_domain_tab {
+	&get_dns('/adm/dns/domain',\&parse_domain_tab);
+	my $fh;
+	if (open($fh,"<".$perlvar{'lonTabDir'}.'/domain.tab')) {
+	    my @lines = <$fh>;
+	    &parse_domain_tab(\@lines);
+	}
+	close($fh);
+	$loaded = 1;
+    }
+
+    sub domain {
+	&load_domain_tab() if (!$loaded);
+
+	my ($name,$what) = @_;
+	return if ( !exists($domain{$name}) );
+
+	if (!$what) {
+	    return $domain{$name}{'description'};
+	}
+	return $domain{$name}{$what};
+    }
 }
 
 
 # ------------------------------------------------------------- Read hosts file
 {
     my %hostname;
-    open(my $config,"<$perlvar{'lonTabDir'}/hosts.tab");
+    my %hostdom;
+    my %libserv;
+    my $loaded;
+
+    sub parse_hosts_tab {
+	my ($file) = @_;
+	foreach my $configline (@$file) {
+	    next if ($configline =~ /^(\#|\s*$ )/x);
+	    next if ($configline =~ /^\^/);
+	    chomp($configline);
+	    my ($id,$domain,$role,$name)=split(/:/,$configline);
+	    $name=~s/\s//g;
+	    if ($id && $domain && $role && $name) {
+		$hostname{$id}=$name;
+		$hostdom{$id}=$domain;
+		if ($role eq 'library') { $libserv{$id}=$name; }
+	    }
+	    &logthis("Hosts.tab: $name ".$id );
+	}
+    }
 
-    while (my $configline=<$config>) {
-       next if ($configline =~ /^(\#|\s*$)/);
-       chomp($configline);
-       my ($id,$domain,$role,$name)=split(/:/,$configline);
-       $name=~s/\s//g;
-       if ($id && $domain && $role && $name) {
-	 $hostname{$id}=$name;
-	 $hostdom{$id}=$domain;
-	 if ($role eq 'library') { $libserv{$id}=$name; }
-       }
+    sub load_hosts_tab {
+	&get_dns('/adm/dns/hosts',\&parse_hosts_tab);
+	open(my $config,"<$perlvar{'lonTabDir'}/hosts.tab");
+	my @config = <$config>;
+	&parse_hosts_tab(\@config);
+	close($config);
+	$loaded=1;
     }
-    close($config);
+
     # FIXME: dev server don't want this, production servers _do_ want this
     #&get_iphost();
 
     sub hostname {
+	&load_hosts_tab() if (!$loaded);
+
 	my ($lonid) = @_;
 	return $hostname{$lonid};
     }
+
     sub all_hostnames {
+	&load_hosts_tab() if (!$loaded);
+
 	return %hostname;
     }
-}
 
-sub get_iphost {
-    if (%iphost) { return %iphost; }
-    my %name_to_ip;
-    my %hostname = &all_hostnames();
-    foreach my $id (keys(%hostname)) {
-	my $name=$hostname{$id};
-	my $ip;
-	if (!exists($name_to_ip{$name})) {
-	    $ip = gethostbyname($name);
-	    if (!$ip || length($ip) ne 4) {
-		&logthis("Skipping host $id name $name no IP found");
-		next;
+    sub is_library {
+	&load_hosts_tab() if (!$loaded);
+
+	return exists($libserv{$_[0]});
+    }
+
+    sub all_library {
+	&load_hosts_tab() if (!$loaded);
+
+	return %libserv;
+    }
+
+    sub get_servers {
+	&load_hosts_tab() if (!$loaded);
+
+	my ($domain,$type) = @_;
+	my %possible_hosts = ($type eq 'library') ? %libserv
+	                                          : %hostname;
+	my %result;
+	if (ref($domain) eq 'ARRAY') {
+	    while ( my ($host,$hostname) = each(%possible_hosts)) {
+		if (grep(/^\Q$hostdom{$host}\E$/,@$domain)) {
+		    $result{$host} = $hostname;
+		}
 	    }
-	    $ip=inet_ntoa($ip);
-	    $name_to_ip{$name} = $ip;
 	} else {
-	    $ip = $name_to_ip{$name};
+	    while ( my ($host,$hostname) = each(%possible_hosts)) {
+		if ($hostdom{$host} eq $domain) {
+		    $result{$host} = $hostname;
+		}
+	    }
+	}
+	return %result;
+    }
+
+    sub host_domain {
+	&load_hosts_tab() if (!$loaded);
+
+	my ($lonid) = @_;
+	return $hostdom{$lonid};
+    }
+
+    sub all_domains {
+	&load_hosts_tab() if (!$loaded);
+
+	my %seen;
+	my @uniq = grep(!$seen{$_}++, values(%hostdom));
+	return @uniq;
+    }
+}
+
+{ 
+    my %iphost;
+    sub get_hosts_from_ip {
+	my ($ip) = @_;
+	my %iphosts = &get_iphost();
+	if (ref($iphosts{$ip})) {
+	    return @{$iphosts{$ip}};
+	}
+	return;
+    }
+    
+    sub get_iphost {
+	if (%iphost) { return %iphost; }
+	my %name_to_ip;
+	my %hostname = &all_hostnames();
+	foreach my $id (keys(%hostname)) {
+	    my $name=$hostname{$id};
+	    my $ip;
+	    if (!exists($name_to_ip{$name})) {
+		$ip = gethostbyname($name);
+		if (!$ip || length($ip) ne 4) {
+		    &logthis("Skipping host $id name $name no IP found");
+		    next;
+		}
+		$ip=inet_ntoa($ip);
+		$name_to_ip{$name} = $ip;
+	    } else {
+		$ip = $name_to_ip{$name};
+	    }
+	    push(@{$iphost{$ip}},$id);
 	}
-	push(@{$iphost{$ip}},$id);
+	return %iphost;
     }
-    return %iphost;
 }
 
 # ------------------------------------------------------ Read spare server file