--- loncom/lonnet/perl/lonnet.pm	2020/05/04 15:07:10	1.1172.2.123
+++ loncom/lonnet/perl/lonnet.pm	2021/03/08 14:48:41	1.1172.2.140.2.1
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.1172.2.123 2020/05/04 15:07:10 raeburn Exp $
+# $Id: lonnet.pm,v 1.1172.2.140.2.1 2021/03/08 14:48:41 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -125,12 +125,13 @@ our @EXPORT = qw(%env);
 	$logid ++;
         my $now = time();
 	my $id=$now.'00000'.$$.'00000'.$logid;
+        my $ip = &get_requestor_ip();  
         my $logentry = {
                          $id => {
                                   'exe_uname' => $env{'user.name'},
                                   'exe_udom'  => $env{'user.domain'},
                                   'exe_time'  => $now,
-                                  'exe_ip'    => $ENV{'REMOTE_ADDR'},
+                                  'exe_ip'    => $ip,
                                   'delflag'   => $delflag,
                                   'logentry'  => $storehash,
                                   'uname'     => $uname,
@@ -1082,6 +1083,21 @@ sub check_for_balancer_cookie {
     return ($otherserver,$cookie);
 }
 
+sub updatebalcookie {
+    my ($cookie,$balancer,$lastentry)=@_;
+    if ($cookie =~ /^($match_domain)\_($match_username)\_[a-f0-9]{32}$/) {
+        my ($udom,$uname) = ($1,$2);
+        my $uprimary_id = &domain($udom,'primary');
+        my $uintdom = &internet_dom($uprimary_id);
+        my $intdom = &internet_dom($balancer);
+        my $serverhomedom = &host_domain($balancer);
+        if (($uintdom ne '') && ($uintdom eq $intdom)) {
+            return &reply('updatebalcookie:'.&escape($cookie).':'.&escape($lastentry),$balancer);
+        }
+    }
+    return;
+}
+
 sub delbalcookie {
     my ($cookie,$balancer) =@_;
     if ($cookie =~ /^($match_domain)\_($match_username)\_[a-f0-9]{32}$/) {
@@ -1091,7 +1107,7 @@ sub delbalcookie {
         my $intdom = &internet_dom($balancer);
         my $serverhomedom = &host_domain($balancer);
         if (($uintdom ne '') && ($uintdom eq $intdom)) {
-            return &reply("delbalcookie:$cookie",$balancer);
+            return &reply('delbalcookie:'.&escape($cookie),$balancer);
         }
     }
 }
@@ -1360,6 +1376,15 @@ sub spare_can_host {
             $canhost = 0;
         }
     }
+    if ($canhost) {
+        if (ref($defdomdefaults{'offloadoth'}) eq 'HASH') {
+            if ($defdomdefaults{'offloadoth'}{$try_server}) {
+                unless (&shared_institution($udom,$try_server)) {
+                    $canhost = 0;
+                }
+            }
+        }
+    }
     if (($canhost) && ($uint_dom)) {
         my @intdoms;
         my $internet_names = &get_internet_names($try_server);
@@ -1578,7 +1603,7 @@ sub check_loadbalancing {
     if ($domneedscache) {
         &do_cache_new('loadbalancing',$domneedscache,$is_balancer,$cachetime);
     }
-    if ($is_balancer) {
+    if (($is_balancer) && ($caller ne 'switchserver')) {
         my $lowest_load = 30000;
         if (ref($offloadto) eq 'HASH') {
             if (ref($offloadto->{'primary'}) eq 'ARRAY') {
@@ -1618,9 +1643,9 @@ sub check_loadbalancing {
                 }
             }
         }
-        unless ($homeintdom) {
-            undef($setcookie);
-        }
+    }
+    if (($is_balancer) && (!$homeintdom)) {
+        undef($setcookie);
     }
     return ($is_balancer,$otherserver,$setcookie);
 }
@@ -1873,7 +1898,13 @@ sub get_dom {
         }
     }
     if ($udom && $uhome && ($uhome ne 'no_host')) {
-        my $rep=&reply("getdom:$udom:$namespace:$items",$uhome);
+        my $rep;
+        if (grep { $_ eq $uhome } &current_machine_ids()) {
+            # domain information is hosted on this machine
+            $rep = &LONCAPA::Lond::get_dom("getdom:$udom:$namespace:$items");
+        } else {        
+            $rep=&reply("getdom:$udom:$namespace:$items",$uhome);
+        }
         my %returnhash;
         if ($rep eq '' || $rep =~ /^error: 2 /) {
             return %returnhash;
@@ -2400,6 +2431,9 @@ sub get_domain_defaults {
         if (ref($domconfig{'usersessions'}{'offloadnow'}) eq 'HASH') {
             $domdefaults{'offloadnow'} = $domconfig{'usersessions'}{'offloadnow'};
         }
+        if (ref($domconfig{'usersessions'}{'offloadoth'}) eq 'HASH') {
+            $domdefaults{'offloadoth'} = $domconfig{'usersessions'}{'offloadoth'};
+        }
     }
     if (ref($domconfig{'selfenrollment'}) eq 'HASH') {
         if (ref($domconfig{'selfenrollment'}{'admin'}) eq 'HASH') {
@@ -3069,6 +3103,27 @@ sub repcopy {
     }
 }
 
+# ------------------------------------------------- Unsubscribe from a resource
+
+sub unsubscribe {
+    my ($fname) = @_;
+    my $answer;
+    if ($fname=~/\/(aboutme|syllabus|bulletinboard|smppg)$/) { return $answer; }
+    $fname=~s/[\n\r]//g;
+    my $author=$fname;
+    $author=~s/\/home\/httpd\/html\/res\/([^\/]*)\/([^\/]*).*/$1\/$2/;
+    my ($udom,$uname)=split(/\//,$author);
+    my $home=homeserver($uname,$udom);
+    if ($home eq 'no_host') {
+        $answer = 'no_host';
+    } elsif (grep { $_ eq $home } &current_machine_ids()) {
+        $answer = 'home';
+    } else {
+        $answer = reply("unsub:$fname",$home);
+    }
+    return $answer;
+}
+
 # ------------------------------------------------ Get server side include body
 sub ssi_body {
     my ($filelink,%form)=@_;
@@ -3227,12 +3282,18 @@ sub remove_stale_resfile {
                                     $stale = 1;
                                 }
                                 if ($stale) {
-                                    unlink($fname);
-                                    if ($uri!~/\.meta$/) {
-                                        unlink($fname.'.meta');
+                                    if (unlink($fname)) {
+                                        if ($uri!~/\.meta$/) {
+                                            if (-e $fname.'.meta') {
+                                                unlink($fname.'.meta');
+                                            }
+                                        }
+                                        my $unsubresult = &unsubscribe($fname);
+                                        unless ($unsubresult eq 'ok') {
+                                            &logthis("no unsub of $fname from $homeserver, reason: $unsubresult");
+                                        }
+                                        $removed = 1;
                                     }
-                                    &reply("unsub:$fname",$homeserver);
-                                    $removed = 1;
                                 }
                             }
                         }
@@ -3675,6 +3736,10 @@ sub clean_filename {
 # Replace all .\d. sequences with _\d. so they no longer look like version
 # numbers
     $fname=~s/\.(\d+)(?=\.)/_$1/g;
+# Replace three or more adjacent underscores with one for consistency
+# with loncfile::filename_check() so complete url can be extracted by
+# lonnet::decode_symb()
+    $fname=~s/_{3,}/_/g;
     return $fname;
 }
 
@@ -4645,7 +4710,11 @@ sub courseacclog {
                 if ($formitem =~ /^HWFILE(?:SIZE|TOOBIG)/) {
                     $what.=':'.$formitem.'='.$env{$key};
                 } elsif ($formitem !~ /^HWFILE(?:[^.]+)$/) {
-                    $what.=':'.$formitem.'='.$env{$key};
+                    if ($formitem eq 'proctorpassword') {
+                        $what.=':'.$formitem.'=' . '*' x length($env{$key});
+                    } else {
+                        $what.=':'.$formitem.'='.$env{$key};
+                    }
                 }
             }
         }
@@ -5401,9 +5470,10 @@ my %cachedtimes=();
 my $cachedtime='';
 
 sub load_all_first_access {
-    my ($uname,$udom)=@_;
+    my ($uname,$udom,$ignorecache)=@_;
     if (($cachedkey eq $uname.':'.$udom) &&
-        (abs($cachedtime-time)<5) && (!$env{'form.markaccess'})) {
+        (abs($cachedtime-time)<5) && (!$env{'form.markaccess'}) &&
+        (!$ignorecache)) {
         return;
     }
     $cachedtime=time;
@@ -5412,7 +5482,7 @@ sub load_all_first_access {
 }
 
 sub get_first_access {
-    my ($type,$argsymb,$argmap)=@_;
+    my ($type,$argsymb,$argmap,$ignorecache)=@_;
     my ($symb,$courseid,$udom,$uname)=&whichuser();
     if ($argsymb) { $symb=$argsymb; }
     my ($map,$id,$res)=&decode_symb($symb);
@@ -5424,7 +5494,7 @@ sub get_first_access {
     } else {
 	$res=$symb;
     }
-    &load_all_first_access($uname,$udom);
+    &load_all_first_access($uname,$udom,$ignorecache);
     return $cachedtimes{"$courseid\0$res"};
 }
 
@@ -5476,13 +5546,14 @@ sub checkout {
     my ($symb,$tuname,$tudom,$tcrsid)=@_;
     my $now=time;
     my $lonhost=$perlvar{'lonHostID'};
+    my $ip = &get_requestor_ip();
     my $infostr=&escape(
                  'CHECKOUTTOKEN&'.
                  $tuname.'&'.
                  $tudom.'&'.
                  $tcrsid.'&'.
                  $symb.'&'.
-                 $now.'&'.$ENV{'REMOTE_ADDR'});
+                 $now.'&'.$ip);
     my $token=&reply('tmpput:'.$infostr,$lonhost);
     if ($token=~/^error\:/) {
         &logthis("<font color=\"blue\">WARNING: ".
@@ -5496,7 +5567,7 @@ sub checkout {
 
     my %infohash=('resource.0.outtoken' => $token,
                   'resource.0.checkouttime' => $now,
-                  'resource.0.outremote' => $ENV{'REMOTE_ADDR'});
+                  'resource.0.outremote' => $ip);
 
     unless (&cstore(\%infohash,$symb,$tcrsid,$tudom,$tuname) eq 'ok') {
        return '';
@@ -5527,6 +5598,7 @@ sub checkin {
     $lonhost=~tr/A-Z/a-z/;
     my $dtoken=$ta.'_'.&hostname($lonhost).'_'.$tb;
     $dtoken=~s/\W/\_/g;
+    my $ip = &get_requestor_ip();
     my ($dummy,$tuname,$tudom,$tcrsid,$symb,$chtim,$rmaddr)=
                  split(/\&/,&unescape(&reply('tmpget:'.$dtoken,$lonhost)));
 
@@ -5543,7 +5615,7 @@ sub checkin {
 
     my %infohash=('resource.0.intoken' => $token,
                   'resource.0.checkintime' => $now,
-                  'resource.0.inremote' => $ENV{'REMOTE_ADDR'});
+                  'resource.0.inremote' => $ip);
 
     unless (&cstore(\%infohash,$symb,$tcrsid,$tudom,$tuname) eq 'ok') {
        return '';
@@ -5811,7 +5883,7 @@ sub tmpreset {
   if (!$domain) { $domain=$env{'user.domain'}; }
   if (!$stuname) { $stuname=$env{'user.name'}; }
   if ($domain eq 'public' && $stuname eq 'public') {
-      $stuname=$ENV{'REMOTE_ADDR'};
+      $stuname=&get_requestor_ip();
   }
   my $path=LONCAPA::tempdir();
   my %hash;
@@ -5848,7 +5920,7 @@ sub tmpstore {
   if (!$domain) { $domain=$env{'user.domain'}; }
   if (!$stuname) { $stuname=$env{'user.name'}; }
   if ($domain eq 'public' && $stuname eq 'public') {
-      $stuname=$ENV{'REMOTE_ADDR'};
+      $stuname=&get_requestor_ip();
   }
   my $now=time;
   my %hash;
@@ -5892,7 +5964,7 @@ sub tmprestore {
   if (!$domain) { $domain=$env{'user.domain'}; }
   if (!$stuname) { $stuname=$env{'user.name'}; }
   if ($domain eq 'public' && $stuname eq 'public') {
-      $stuname=$ENV{'REMOTE_ADDR'};
+      $stuname=&get_requestor_ip();
   }
   my %returnhash;
   $namespace=~s/\//\_/g;
@@ -5948,7 +6020,7 @@ sub store {
     }
     if (!$home) { $home=$env{'user.home'}; }
 
-    $$storehash{'ip'}=$ENV{'REMOTE_ADDR'};
+    $$storehash{'ip'}=&get_requestor_ip();
     $$storehash{'host'}=$perlvar{'lonHostID'};
 
     my $namevalue='';
@@ -5984,7 +6056,7 @@ sub cstore {
     }
     if (!$home) { $home=$env{'user.home'}; }
 
-    $$storehash{'ip'}=$ENV{'REMOTE_ADDR'};
+    $$storehash{'ip'}=&get_requestor_ip();
     $$storehash{'host'}=$perlvar{'lonHostID'};
 
     my $namevalue='';
@@ -6976,7 +7048,8 @@ sub putstore {
        foreach my $key (keys(%{$storehash})) {
            $namevalue.=&escape($key).'='.&freeze_escape($storehash->{$key}).'&';
        }
-       $namevalue .= 'ip='.&escape($ENV{'REMOTE_ADDR'}).
+       my $ip = &get_requestor_ip();
+       $namevalue .= 'ip='.&escape($ip).
                      '&host='.&escape($perlvar{'lonHostID'}).
                      '&version='.$esc_v.
                      '&by='.&escape($env{'user.name'}.':'.$env{'user.domain'});
@@ -7757,7 +7830,7 @@ sub customaccess {
 # ------------------------------------------------- Check for a user privilege
 
 sub allowed {
-    my ($priv,$uri,$symb,$role,$clientip,$noblockcheck)=@_;
+    my ($priv,$uri,$symb,$role,$clientip,$noblockcheck,$ignorecache)=@_;
     my $ver_orguri=$uri;
     $uri=&deversion($uri);
     my $orguri=$uri;
@@ -7774,7 +7847,7 @@ sub allowed {
 
     if (defined($env{'allowed.'.$priv})) { return $env{'allowed.'.$priv}; }
 # Free bre access to adm and meta resources
-    if (((($uri=~/^adm\//) && ($uri !~ m{/(?:smppg|bulletinboard)$})) 
+    if (((($uri=~/^adm\//) && ($uri !~ m{/(?:smppg|bulletinboard|viewclasslist|aboutme)$})) 
 	 || (($uri=~/\.meta$/) && ($uri!~m|^uploaded/|) )) 
 	&& ($priv eq 'bre')) {
 	return 'F';
@@ -7982,7 +8055,7 @@ sub allowed {
                 if ($noblockcheck) {
                     $thisallowed.=$value;
                 } else {
-                    my @blockers = &has_comm_blocking($priv,$symb,$uri);
+                    my @blockers = &has_comm_blocking($priv,$symb,$uri,$ignorecache);
                     if (@blockers > 0) {
                         $thisallowed = 'B';
                     } else {
@@ -8002,7 +8075,7 @@ sub allowed {
                         if ($noblockcheck) {
                             $thisallowed='F';
                         } else {
-                            my @blockers = &has_comm_blocking($priv,$symb,$refuri);
+                            my @blockers = &has_comm_blocking($priv,'',$refuri,'',1);
                             if (@blockers > 0) {
                                 $thisallowed = 'B';
                             } else {
@@ -8075,7 +8148,7 @@ sub allowed {
                    if ($noblockcheck) {
                        $thisallowed.=$value;
                    } else {
-                       my @blockers = &has_comm_blocking($priv,$symb,$uri);
+                       my @blockers = &has_comm_blocking($priv,$symb,$uri,$ignorecache);
                        if (@blockers > 0) {
                            $thisallowed = 'B';
                        } else {
@@ -8088,7 +8161,7 @@ sub allowed {
                $checkreferer=0;
            }
        }
-       
+
        if ($checkreferer) {
 	  my $refuri=$env{'httpref.'.$orguri};
             unless ($refuri) {
@@ -8117,7 +8190,7 @@ sub allowed {
                       if ($noblockcheck) {
                           $thisallowed.=$value;
                       } else {
-                          my @blockers = &has_comm_blocking($priv,$symb,$refuri);
+                          my @blockers = &has_comm_blocking($priv,'',$refuri,'',1);
                           if (@blockers > 0) {
                               $thisallowed = 'B';
                           } else {
@@ -8203,7 +8276,7 @@ sub allowed {
 	   }
        }
     }
-   
+
 #
 # Rest of the restrictions depend on selected course
 #
@@ -8361,22 +8434,27 @@ sub constructaccess {
 #
 # User for whom data are being temporarily cached.
 my $cacheduser='';
+# Course for which data are being temporarily cached.
+my $cachedcid='';
 # Cached blockers for this user (a hash of blocking items).
 my %cachedblockers=();
 # When the data were last cached.
 my $cachedlast='';
 
 sub load_all_blockers {
-    my ($uname,$udom,$blocks)=@_;
+    my ($uname,$udom)=@_;
     if (($uname ne '') && ($udom ne '')) {
         if (($cacheduser eq $uname.':'.$udom) &&
+            ($cachedcid eq $env{'request.course.id'}) &&
             (abs($cachedlast-time)<5)) {
             return;
         }
     }
     $cachedlast=time;
     $cacheduser=$uname.':'.$udom;
-    %cachedblockers = &get_commblock_resources($blocks);
+    $cachedcid=$env{'request.course.id'};
+    %cachedblockers = &get_commblock_resources();
+    return;
 }
 
 sub get_comm_blocks {
@@ -8456,14 +8534,23 @@ sub get_commblock_resources {
                             if ($mapsymb) {
                                 if (ref($navmap)) {
                                     my $mapres = $navmap->getBySymb($mapsymb);
-                                    @to_test = $mapres->retrieveResources($mapres,undef,0,0,0,1);
-                                    foreach my $res (@to_test) {
-                                        my $symb = $res->symb();
-                                        next if ($symb eq $mapsymb);
-                                        if ($symb ne '') {
-                                            @interval=&EXT("resource.0.interval",$symb);
-                                            if ($interval[1] eq 'map') {
-                                                last;
+                                    if (ref($mapres)) {
+                                        my $first = $mapres->map_start();
+                                        my $finish = $mapres->map_finish();
+                                        my $it = $navmap->getIterator($first,$finish,undef,0,0);
+                                        if (ref($it)) {
+                                            my $res;
+                                            while ($res = $it->next(undef,1)) {
+                                                next unless (ref($res));
+                                                my $symb = $res->symb();
+                                                next if (($symb eq $mapsymb) || ($symb eq ''));
+                                                @interval=&EXT("resource.0.interval",$symb);
+                                                if ($interval[1] eq 'map') {
+                                                    if ($res->answerable()) {
+                                                        push(@to_test,$res);
+                                                        last;
+                                                    }
+                                                }
                                             }
                                         }
                                     }
@@ -8471,7 +8558,8 @@ sub get_commblock_resources {
                             }
                         }
                     }
-                    if ($interval[0] =~ /^\d+$/) {
+                    if ($interval[0] =~ /^(\d+)/) {
+                        my $timelimit = $1;
                         my $first_access;
                         if ($type eq 'resource') {
                             $first_access=&get_first_access($interval[1],$item);
@@ -8481,7 +8569,7 @@ sub get_commblock_resources {
                             $first_access=&get_first_access($interval[1]);
                         }
                         if ($first_access) {
-                            my $timesup = $first_access+$interval[0];
+                            my $timesup = $first_access+$timelimit;
                             if ($timesup > $now) {
                                 my $activeblock;
                                 foreach my $res (@to_test) {
@@ -8513,17 +8601,23 @@ sub get_commblock_resources {
 }
 
 sub has_comm_blocking {
-    my ($priv,$symb,$uri,$blocks) = @_;
+    my ($priv,$symb,$uri,$ignoresymbdb,$noenccheck,$blocked,$blocks) = @_;
     my @blockers;
     return unless ($env{'request.course.id'});
     return unless ($priv eq 'bre');
     return if ($env{'user.priv.'.$env{'request.role'}} =~/evb\&([^\:]*)/);
     return if ($env{'request.state'} eq 'construct');
-    &load_all_blockers($env{'user.name'},$env{'user.domain'},$blocks);
-    return unless (keys(%cachedblockers) > 0);
+    my %blockinfo;
+    if (ref($blocks) eq 'HASH') {
+        %blockinfo = &get_commblock_resources($blocks);
+    } else {
+        &load_all_blockers($env{'user.name'},$env{'user.domain'});
+        %blockinfo = %cachedblockers;
+    }
+    return unless (keys(%blockinfo) > 0);
     my (%possibles,@symbs);
     if (!$symb) {
-        $symb = &symbread($uri,1,1,1,\%possibles);
+        $symb = &symbread($uri,1,1,1,\%possibles,$ignoresymbdb,$noenccheck);
     }
     if ($symb) {
         @symbs = ($symb);
@@ -8534,34 +8628,38 @@ sub has_comm_blocking {
     foreach my $symb (@symbs) {
         last if ($noblock);
         my ($map,$resid,$resurl)=&decode_symb($symb);
-        foreach my $block (keys(%cachedblockers)) {
+        foreach my $block (keys(%blockinfo)) {
             if ($block =~ /^firstaccess____(.+)$/) {
                 my $item = $1;
-                if (($item eq $map) || ($item eq $symb)) {
-                    $noblock = 1;
-                    last;
+                unless ($blocked) {
+                    if (($item eq $map) || ($item eq $symb)) {
+                        $noblock = 1;
+                        last;
+                    }
                 }
             }
-            if (ref($cachedblockers{$block}) eq 'HASH') {
-                if (ref($cachedblockers{$block}{'resources'}) eq 'HASH') {
-                    if ($cachedblockers{$block}{'resources'}{$symb}) {
+            if (ref($blockinfo{$block}) eq 'HASH') {
+                if (ref($blockinfo{$block}{'resources'}) eq 'HASH') {
+                    if ($blockinfo{$block}{'resources'}{$symb}) {
                         unless (grep(/^\Q$block\E$/,@blockers)) {
                             push(@blockers,$block);
                         }
                     }
                 }
-            }
-            if (ref($cachedblockers{$block}{'maps'}) eq 'HASH') {
-                if ($cachedblockers{$block}{'maps'}{$map}) {
-                    unless (grep(/^\Q$block\E$/,@blockers)) {
-                        push(@blockers,$block);
+                if (ref($blockinfo{$block}{'maps'}) eq 'HASH') {
+                    if ($blockinfo{$block}{'maps'}{$map}) {
+                        unless (grep(/^\Q$block\E$/,@blockers)) {
+                            push(@blockers,$block);
+                        }
                     }
                 }
             }
         }
     }
-    return if ($noblock);
-    return @blockers;
+    unless ($noblock) {
+        return @blockers;
+    }
+    return;
 }
 }
 
@@ -9876,13 +9974,14 @@ sub modifyuserauth {
              ' in domain '.$env{'request.role.domain'});  
     my $reply=&reply('encrypt:changeuserauth:'.$udom.':'.$uname.':'.$umode.':'.
 		     &escape($upass),$uhome);
+    my $ip = &get_requestor_ip();
     &log($env{'user.domain'},$env{'user.name'},$env{'user.home'},
         'Authentication changed for '.$udom.', '.$uname.', '.$umode.
-         '(Remote '.$ENV{'REMOTE_ADDR'}.'): '.$reply);
+         '(Remote '.$ip.'): '.$reply);
     &log($udom,,$uname,$uhome,
         'Authentication changed by '.$env{'user.domain'}.', '.
                                      $env{'user.name'}.', '.$umode.
-         '(Remote '.$ENV{'REMOTE_ADDR'}.'): '.$reply);
+         '(Remote '.$ip.'): '.$reply);
     unless ($reply eq 'ok') {
         &logthis('Authentication mode error: '.$reply);
 	return 'error: '.$reply;
@@ -10398,7 +10497,7 @@ sub store_userdata {
             if (($uhome eq '') || ($uhome eq 'no_host')) {
                 $result = 'error: no_host';
             } else {
-                $storehash->{'ip'} = $ENV{'REMOTE_ADDR'};
+                $storehash->{'ip'} = &get_requestor_ip();
                 $storehash->{'host'} = $perlvar{'lonHostID'};
 
                 my $namevalue='';
@@ -12400,13 +12499,16 @@ sub deversion {
 # ------------------------------------------------------ Return symb list entry
 
 sub symbread {
-    my ($thisfn,$donotrecurse,$ignorecachednull,$checkforblock,$possibles)=@_;
+    my ($thisfn,$donotrecurse,$ignorecachednull,$checkforblock,$possibles,
+        $ignoresymbdb,$noenccheck)=@_;
     my $cache_str='request.symbread.cached.'.$thisfn;
     if (defined($env{$cache_str})) {
-        if ($ignorecachednull) {
-            return $env{$cache_str} unless ($env{$cache_str} eq '');
-        } else {
-            return $env{$cache_str};
+        unless (ref($possibles) eq 'HASH') {
+            if ($ignorecachednull) {
+                return $env{$cache_str} unless ($env{$cache_str} eq '');
+            } else {
+                return $env{$cache_str};
+            }
         }
     }
 # no filename provided? try from environment
@@ -12435,10 +12537,18 @@ sub symbread {
 	if ($targetfn =~ m|^adm/wrapper/(ext/.*)|) {
 	    $targetfn=$1;
 	}
-        if (tie(%hash,'GDBM_File',$env{'request.course.fn'}.'_symb.db',
-                      &GDBM_READER(),0640)) {
-	    $syval=$hash{$targetfn};
-            untie(%hash);
+        unless ($ignoresymbdb) {
+            if (tie(%hash,'GDBM_File',$env{'request.course.fn'}.'_symb.db',
+                          &GDBM_READER(),0640)) {
+	        $syval=$hash{$targetfn};
+                untie(%hash);
+            }
+            if ($syval && $checkforblock) {
+                my @blockers = &has_comm_blocking('bre',$syval,$thisfn,$ignoresymbdb,$noenccheck);
+                if (@blockers) {
+                    $syval='';
+                }
+            }
         }
 # ---------------------------------------------------------- There was an entry
         if ($syval) {
@@ -12471,13 +12581,18 @@ sub symbread {
 		     $syval=&encode_symb($bighash{'map_id_'.$mapid},
 						    $resid,$thisfn);
                      if (ref($possibles) eq 'HASH') {
-                         $possibles->{$syval} = 1;
+                         unless ($bighash{'randomout_'.$ids} || $env{'request.role.adv'}) {
+                             $possibles->{$syval} = 1;
+                         }
                      }
                      if ($checkforblock) {
-                         my @blockers = &has_comm_blocking('bre',$syval,$bighash{'src_'.$ids});
-                         if (@blockers) {
-                             $syval = '';
-                             return;
+                         unless ($bighash{'randomout_'.$ids} || $env{'request.role.adv'}) {
+                             my @blockers = &has_comm_blocking('bre',$syval,$bighash{'src_'.$ids},'',$noenccheck);
+                             if (@blockers) {
+                                 $syval = '';
+                                 untie(%bighash);
+                                 return $env{$cache_str}='';
+                             }
                          }
                      }
                  } elsif ((!$donotrecurse) || ($checkforblock) || (ref($possibles) eq 'HASH')) {
@@ -12496,12 +12611,13 @@ sub symbread {
                              if ($bighash{'map_type_'.$mapid} ne 'page') {
                                  my $poss_syval=&encode_symb($bighash{'map_id_'.$mapid},
                                                              $resid,$thisfn);
-                                 if (ref($possibles) eq 'HASH') {
-                                     $possibles->{$syval} = 1;
-                                 }
+                                 next if ($bighash{'randomout_'.$id} && !$env{'request.role.adv'});
+                                 next unless (($noenccheck) || ($bighash{'encrypted_'.$id} eq $env{'request.enc'}));
                                  if ($checkforblock) {
-                                     my @blockers = &has_comm_blocking('bre',$poss_syval,$file);
-                                     unless (@blockers > 0) {
+                                     my @blockers = &has_comm_blocking('bre',$poss_syval,$file,'',$noenccheck);
+                                     if (@blockers > 0) {
+                                         $syval = '';
+                                     } else {
                                          $syval = $poss_syval;
                                          $realpossible++;
                                      }
@@ -12509,6 +12625,11 @@ sub symbread {
                                      $syval = $poss_syval;
                                      $realpossible++;
                                  }
+                                 if ($syval) {
+                                     if (ref($possibles) eq 'HASH') {
+                                         $possibles->{$syval} = 1;
+                                     }
+                                 }
                              }
 			 }
                      }
@@ -13250,9 +13371,12 @@ sub default_login_domain {
 }
 
 sub shared_institution {
-    my ($dom) = @_;
+    my ($dom,$lonhost) = @_;
+    if ($lonhost eq '') {
+        $lonhost = $perlvar{'lonHostID'};
+    }
     my $same_intdom;
-    my $hostintdom = &internet_dom($perlvar{'lonHostID'});
+    my $hostintdom = &internet_dom($lonhost);
     if ($hostintdom ne '') {
         my %iphost = &get_iphost();
         my $primary_id = &domain($dom,'primary');
@@ -13309,6 +13433,17 @@ sub uses_sts {
     return;
 }
 
+sub get_requestor_ip {
+    my ($r,$nolookup,$noproxy) = @_;
+    my $from_ip;
+    if (ref($r)) {
+        $from_ip = $r->get_remote_host($nolookup);
+    } else {
+        $from_ip = $ENV{'REMOTE_ADDR'};
+    }
+    return $from_ip;
+}
+
 # ------------------------------------------------------------- Declutters URLs
 
 sub declutter {