--- loncom/auth/lonauth.pm	2008/07/13 00:51:31	1.94
+++ loncom/auth/lonauth.pm	2014/05/04 15:16:10	1.121.2.11
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # User Authentication Module
 #
-# $Id: lonauth.pm,v 1.94 2008/07/13 00:51:31 raeburn Exp $
+# $Id: lonauth.pm,v 1.121.2.11 2014/05/04 15:16:10 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -40,6 +40,8 @@ use Apache::lonmenu();
 use Apache::createaccount;
 use Fcntl qw(:flock);
 use Apache::lonlocal;
+use Apache::File();
+use HTML::Entities;
  
 # ------------------------------------------------------------ Successful login
 sub success {
@@ -73,20 +75,67 @@ sub success {
 # ------------------------------------------------------------ Get cookie ready
     $cookie="lonID=$cookie; path=/";
 # -------------------------------------------------------- Menu script and info
+    my $destination = $lowerurl;
+
+    if (defined($form->{role})) {
+        my $envkey = 'user.role.'.$form->{role};
+        my $now=time;
+        my $then=$env{'user.login.time'};
+        my $refresh=$env{'user.refresh.time'};
+        my $update=$env{'user.update.time'};
+        if (!$update) {
+            $update = $then;
+        }
+        if (exists($env{$envkey})) {
+            my ($role,$where,$trolecode,$tstart,$tend,$tremark,$tstatus);
+            &Apache::lonnet::role_status($envkey,$update,$refresh,$now,\$role,\$where,
+                                         \$trolecode,\$tstatus,\$tstart,\$tend);
+            if ($tstatus eq 'is') {
+                $destination  .= ($destination =~ /\?/) ? '&' : '?';
+                my $newrole = &HTML::Entities::encode($form->{role},'"<>&');
+                $destination .= 'selectrole=1&'.$newrole.'=1';
+            }
+        }
+    }
+    if (defined($form->{symb})) {
+        my $destsymb = $form->{symb};
+        $destination  .= ($destination =~ /\?/) ? '&' : '?';
+        if ($destsymb =~ /___/) {
+            # FIXME Need to deal with encrypted symbs and urls as needed.
+            my ($map,$resid,$desturl)=split(/___/,$destsymb);
+            unless ($desturl=~/^(adm|editupload|public)/) {
+                $desturl = &Apache::lonnet::clutter($desturl);
+            }
+            $desturl = &HTML::Entities::encode($desturl,'"<>&');
+            $destsymb = &HTML::Entities::encode($destsymb,'"<>&');
+            $destination .= 'destinationurl='.$desturl.
+                            '&destsymb='.$destsymb;
+        } else {
+            $destsymb = &HTML::Entities::encode($destsymb,'"<>&');
+            $destination .= 'destinationurl='.$destsymb;
+        }
+    }
+    if ($destination =~ m{^/adm/roles}) {
+        $destination  .= ($destination =~ /\?/) ? '&' : '?';
+        $destination .= 'source=login';
+    }
+
     my $windowinfo=&Apache::lonmenu::open($env{'browser.os'});
-    my $startupremote=&Apache::lonmenu::startupremote($lowerurl);
+    my $startupremote=&Apache::lonmenu::startupremote($destination);
     my $remoteinfo=&Apache::lonmenu::load_remote_msg($lowerurl);
     my $setflags=&Apache::lonmenu::setflags();
     my $maincall=&Apache::lonmenu::maincall();
+    my $brcrum = [{'href' => '',
+                   'text' => 'Successful Login'},];
     my $start_page=&Apache::loncommon::start_page('Successful Login',
-						  $startupremote,
-						  {'no_inline_link' => 1,});
+                                                  $startupremote,
+                                                  {'no_inline_link' => 1,
+                                                   'bread_crumbs' => $brcrum,});
     my $end_page  =&Apache::loncommon::end_page();
 
     my $continuelink;
-    if (($env{'browser.interface'} eq 'textual') ||
-        ($env{'environment.remote'} eq 'off')) {
-	$continuelink="<a href=\"$lowerurl\">".&mt('Continue')."</a>";
+    if ($env{'environment.remote'} eq 'off') {
+	$continuelink='<a href="'.$destination.'">'.&mt('Continue').'</a>';
     }
 # ------------------------------------------------- Output for successful login
 
@@ -96,41 +145,81 @@ sub success {
 
     my %lt=&Apache::lonlocal::texthash(
 				       'wel' => 'Welcome',
-				       'mes' => 'Welcome to the Learning<i>Online</i> Network with CAPA. Please wait while your session is being set up.',
 				       'pro' => 'Login problems?',
-				       'log' => 'loginproblems.html',
 				       );
+    my $loginhelp = &loginhelpdisplay($domain);
+    if ($loginhelp) {
+        $loginhelp = '<p><a href="'.$loginhelp.'">'.$lt{'pro'}.'</a></p>';
+    }
+
+    my $welcome = &mt('Welcome to the Learning[_1]Online[_2] Network with CAPA. Please wait while your session is being set up.','<i>','</i>'); 
     $r->print(<<ENDSUCCESS);
 $start_page
 $setflags
 $windowinfo
 <h1>$lt{'wel'}</h1>
-$lt{'mes'}<p>
-<a href="/adm/$lt{'log'}">$lt{'pro'}</a></p>
+$welcome
+$loginhelp
 $remoteinfo
 $maincall
 $continuelink
 $end_page
 ENDSUCCESS
+    return;
 }
 
 # --------------------------------------------------------------- Failed login!
 
 sub failed {
     my ($r,$message,$form) = @_;
-    my $start_page = &Apache::loncommon::start_page('Unsuccessful Login',undef,
-						    {'no_inline_link' => 1,});
-    my $end_page   = &Apache::loncommon::end_page();
+    (undef,undef,undef,my $clientmathml,my $clientunicode) =
+        &Apache::loncommon::decode_user_agent();
+    my $args = {};
+    if ($clientunicode && !$clientmathml) {
+        $args = {'browser.unicode' => 1};
+    }
+
+    my $start_page = &Apache::loncommon::start_page('Unsuccessful Login',undef,$args);
+    my $uname = &Apache::loncommon::cleanup_html($form->{'uname'});
+    my $udom = &Apache::loncommon::cleanup_html($form->{'udom'});
+    if (&Apache::lonnet::domain($udom,'description') eq '') {
+        undef($udom);
+    }
+    my $retry = '/adm/login';
+    if ($uname eq $form->{'uname'}) {
+        $retry .= '?username='.$uname;
+    }
+    if ($udom) {
+        $retry .= (($retry=~/\?/)?'&amp;':'?').'domain='.$udom;
+    }
+    if (exists($form->{role})) {
+        my $role = &Apache::loncommon::cleanup_html($form->{role});
+        if ($role ne '') {
+            $retry .= (($retry=~/\?/)?'&amp;':'?').'role='.$role;
+        }
+    }
+    if (exists($form->{symb})) {
+        my $symb = &Apache::loncommon::cleanup_html($form->{symb});
+        if ($symb ne '') {
+            $retry .= (($retry=~/\?/)?'&amp;':'?').'symb='.$symb;
+        }
+    }
+    my $end_page = &Apache::loncommon::end_page();
     &Apache::loncommon::content_type($r,'text/html');
     $r->send_http_header;
+    my @actions =
+         (&mt('Please [_1]log in again[_2].','<a href="'.$retry.'">','</a>'));
+    my $loginhelp = &loginhelpdisplay($udom);
+    if ($loginhelp) {
+        push(@actions, '<a href="'.$loginhelp.'">'.&mt('Login problems?').'</a>');
+    }
+    #FIXME: link to helpdesk might be added here
+
     $r->print(
        $start_page
-      .'<h1>'.&mt('Sorry ...').'</h1>'
-      .'<p><b>'.&mt($message).'</b></p>'
-      .'<p>'.&mt('Please [_1]log in again[_2].'
-                ,"<a href=\"/adm/login?username=$form->{'uname'}&domain=$form->{'udom'}\">",'</a>')
-      .'</p>'
-      .'<p><a href="/adm/loginproblems.html">'.&mt('Login problems?').'</a></p>'
+      .'<h2>'.&mt('Sorry ...').'</h2>'
+      .&Apache::lonhtmlcommon::confirm_success(&mt($message),1).'<br /><br />'
+      .&Apache::lonhtmlcommon::actionbox(\@actions)
       .$end_page
     );
  }
@@ -141,18 +230,19 @@ sub reroute {
     my ($r) = @_;
     &Apache::loncommon::content_type($r,'text/html');
     $r->send_http_header;
-    my $msg='<h1>'.&mt('Sorry ...').'</h1>'
+    my $msg='<b>'.&mt('Sorry ...').'</b><br />'
            .&mt('Please [_1]log in again[_2].');
-    &Apache::loncommon::simple_error_page($r,'Rerouting',$msg);
+    &Apache::loncommon::simple_error_page($r,'Rerouting',$msg,{'no_auto_mt_msg' => 1});
 }
 
 # ---------------------------------------------------------------- Main handler
 
 sub handler {
     my $r = shift;
+    my $londocroot = $r->dir_config('lonDocRoot');
     my $form;
 # Are we re-routing?
-    if (-e '/home/httpd/html/lon-status/reroute.txt') {
+    if (-e "$londocroot/lon-status/reroute.txt") {
 	&reroute($r);
 	return OK;
     }
@@ -162,23 +252,33 @@ sub handler {
 # -------------------------------- Prevent users from attempting to login twice
     my $handle = &Apache::lonnet::check_for_valid_session($r);
     if ($handle ne '') {
+        my $lonidsdir=$r->dir_config('lonIDsDir');
+        if ($handle=~/^publicuser\_/) {
+# For "public user" - remove it, we apparently really want to login
+            unlink($r->dir_config('lonIDsDir')."/$handle.id");
+        } else {
 # Indeed, a valid token is found
-	&Apache::loncommon::content_type($r,'text/html');
-	$r->send_http_header;
-	my $start_page = 
-	    &Apache::loncommon::start_page('Already logged in');
-	my $end_page = 
-	    &Apache::loncommon::end_page();
-        $r->print(
-           $start_page
-          .'<h1>'.&mt('You are already logged in!').'</h1>'
-          .'<p>'.&mt('Please either [_1]continue the current session[_2] or [_3]logout[_4].'
-                    ,'<a href="/adm/roles">','</a>','<a href="/adm/logout">','</a>')
-          .'</p>'
-          .'<p><a href="/adm/loginproblems.html">'.&mt('Login problems?').'</a></p>'
-          .$end_page
-        );
-        return OK;
+            &Apache::lonnet::transfer_profile_to_env($lonidsdir,$handle);
+	    &Apache::loncommon::content_type($r,'text/html');
+	    $r->send_http_header;
+	    my $start_page = 
+	        &Apache::loncommon::start_page('Already logged in');
+	    my $end_page = 
+	        &Apache::loncommon::end_page();
+            my $dest = '/adm/roles';
+            if ($env{'form.firsturl'} ne '') {
+                $dest = $env{'form.firsturl'};
+            }
+            $r->print(
+               $start_page
+              .'<p class="LC_warning">'.&mt('You are already logged in!').'</p>'
+              .'<p>'.&mt('Please either [_1]continue the current session[_2] or [_3]log out[_4].'
+                    ,'<a href="'.$dest.'">','</a>','<a href="/adm/logout">','</a>')
+              .'</p>'
+              .$end_page
+            );
+            return OK;
+        }
     }
 
 # ---------------------------------------------------- No valid token, continue
@@ -194,7 +294,7 @@ sub handler {
        $value =~ tr/+/ /;
        $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;
        $form{$name}=$value;
-    } 
+    }
 
     if ((!$form{'uname'}) || (!$form{'upass0'}) || (!$form{'udom'})) {
 	&failed($r,'Username, password and domain need to be specified.',
@@ -219,7 +319,14 @@ sub handler {
     my $tmpinfo=Apache::lonnet::reply('tmpget:'.$form{'logtoken'},
                                       $form{'serverid'});
 
-    if (($tmpinfo=~/^error/) || ($tmpinfo eq 'con_lost')) {
+    my %sessiondata;
+    if ($form{'iptoken'}) {
+        %sessiondata = &Apache::lonnet::tmpget($form{'iptoken'});
+        my $delete = &Apache::lonnet::tmpdel($form{'iptoken'});
+    }
+
+    if (($tmpinfo=~/^error/) || ($tmpinfo eq 'con_lost') || 
+        ($tmpinfo eq 'no_such_host')) {
 	&failed($r,'Information needed to verify your login information is missing, inaccessible or expired.',\%form);
         return OK;
     } else {
@@ -231,11 +338,25 @@ sub handler {
 	    return OK;
 	}
     }
+
     if (!&Apache::lonnet::domain($form{'udom'})) {
         &failed($r,'The domain you provided is not a valid LON-CAPA domain.',\%form);
         return OK;
     }
-    my ($key,$firsturl)=split(/&/,$tmpinfo);
+
+    my ($key,$firsturl,$rolestr,$symbstr)=split(/&/,$tmpinfo);
+    if ($rolestr) {
+        $rolestr = &unescape($rolestr);
+    }
+    if ($symbstr) {
+        $symbstr= &unescape($symbstr);
+    }
+    if ($rolestr =~ /^role=/) {
+        (undef,$form{'role'}) = split('=',$rolestr);
+    }
+    if ($symbstr =~ /^symb=/) { 
+        (undef,$form{'symb'}) = split('=',$symbstr);
+    }
 
     my $keybin=pack("H16",$key);
 
@@ -259,24 +380,20 @@ sub handler {
     }
 
 # ---------------------------------------------------------------- Authenticate
-    my @cancreate;
+
     my %domconfig = &Apache::lonnet::get_dom('configuration',['usercreation'],$form{'udom'});
-    if (ref($domconfig{'usercreation'}) eq 'HASH') {
-        if (ref($domconfig{'usercreation'}{'cancreate'}) eq 'HASH') {
-            if (ref($domconfig{'usercreation'}{'cancreate'}{'selfcreate'}) eq 'ARRAY') {
-                @cancreate = @{$domconfig{'usercreation'}{'cancreate'}{'selfcreate'}};
-            } elsif (($domconfig{'usercreation'}{'cancreate'}{'selfcreate'} ne 'none') && 
-                     ($domconfig{'usercreation'}{'cancreate'}{'selfcreate'} ne '')) {
-                @cancreate = ($domconfig{'usercreation'}{'cancreate'}{'selfcreate'});
-            }
-        }
-    }
+    my ($cancreate,$statustocreate) =
+        &Apache::createaccount::get_creation_controls($form{'udom'},$domconfig{'usercreation'});
     my $defaultauth;
-    if (grep(/^login$/,@cancreate)) {
-        $defaultauth = 1;
+    if (ref($cancreate) eq 'ARRAY') {
+        if (grep(/^login$/,@{$cancreate})) {
+            $defaultauth = 1;
+        }
     }
+    my $clientcancheckhost = 1;
     my $authhost=Apache::lonnet::authenticate($form{'uname'},$upass,
-                                              $form{'udom'},$defaultauth);
+                                              $form{'udom'},$defaultauth,
+                                              $clientcancheckhost);
     
 # --------------------------------------------------------------------- Failed?
 
@@ -285,22 +402,25 @@ sub handler {
 		\%form);
         return OK;
     } elsif ($authhost eq 'no_account_on_host') {
-        my %domconfig = 
-            &Apache::lonnet::get_dom('configuration',['usercreation'],$form{'udom'});
-        if (grep(/^login$/,@cancreate)) {
+        if ($defaultauth) {
+            my $domdesc = &Apache::lonnet::domain($form{'udom'},'description');
+            unless (&check_can_host($r,\%form,'no_account_on_host',$domdesc)) {
+                return OK;
+            }
             my $start_page = 
                 &Apache::loncommon::start_page('Create a user account in LON-CAPA',
                                                '',{'no_inline_link'   => 1,});
-            my $domdesc = &Apache::lonnet::domain($form{'udom'},'description');
             my $lonhost = $r->dir_config('lonHostID');
             my $origmail = $Apache::lonnet::perlvar{'lonSupportEMail'};
             my $contacts = 
                 &Apache::loncommon::build_recipient_list(undef,'helpdeskmail',
                                                         $form{'udom'},$origmail);
             my ($contact_email) = split(',',$contacts); 
-            my $output = &Apache::createaccount::username_check($form{'uname'}, 
-                                                                $form{'udom'},$domdesc,'',
-                                                                $lonhost,$contact_email,$contact_name);
+            my $output = 
+                &Apache::createaccount::username_check($form{'uname'},$form{'udom'},
+                                                       $domdesc,'',$lonhost,
+                                                       $contact_email,$contact_name,
+                                                       undef,$statustocreate);
             &Apache::loncommon::content_type($r,'text/html');
             $r->send_http_header;
             &Apache::createaccount::print_header($r,$start_page);
@@ -318,6 +438,15 @@ sub handler {
 	($firsturl=~/^\/adm\/(logout|remote)/)) {
 	$firsturl='/adm/roles';
     }
+
+    my $hosthere;
+    if ($form{'iptoken'}) {
+        if (($sessiondata{'domain'} eq $form{'udom'}) &&
+            ($sessiondata{'username'} eq $form{'uname'})) {
+            $hosthere = 1;
+        }
+    }
+
 # --------------------------------- Are we attempting to login as somebody else?
     if ($form{'suname'}) {
 # ------------ see if the original user has enough privileges to pull this stunt
@@ -341,15 +470,188 @@ sub handler {
 	}
     }
 
-    if ($r->dir_config("lonBalancer") eq 'yes') {
-	&success($r,$form{'uname'},$form{'udom'},$authhost,'noredirect',undef,
-		 \%form);
-	$r->internal_redirect('/adm/switchserver');
+    my ($is_balancer,$otherserver);
+
+    unless ($hosthere) {
+        ($is_balancer,$otherserver) =
+            &Apache::lonnet::check_loadbalancing($form{'uname'},$form{'udom'});
+    }
+
+    if ($is_balancer) {
+        if (!$otherserver) { 
+            ($otherserver) = &Apache::lonnet::choose_server($form{'udom'});
+        }
+        if ($otherserver) {
+            &success($r,$form{'uname'},$form{'udom'},$authhost,'noredirect',undef,
+                     \%form);
+            my $switchto = '/adm/switchserver?otherserver='.$otherserver;
+            if (($firsturl) && ($firsturl ne '/adm/switchserver') && ($firsturl ne '/adm/roles')) {
+                $switchto .= '&origurl='.$firsturl;
+            }
+            if ($form{'role'}) {
+                $switchto .= '&role='.$form{'role'};
+            }
+            if ($form{'symb'}) {
+                $switchto .= '&symb='.$form{'symb'};
+            }
+            $r->internal_redirect($switchto);
+        } else {
+            $r->print(&noswitch());
+        }
+        return OK;
     } else {
-	&success($r,$form{'uname'},$form{'udom'},$authhost,$firsturl,undef,
-		 \%form);
+        if (!&check_can_host($r,\%form,$authhost)) {
+            my ($otherserver) = &Apache::lonnet::choose_server($form{'udom'});
+            if ($otherserver) {
+                &success($r,$form{'uname'},$form{'udom'},$authhost,'noredirect',undef,
+                         \%form);
+                my $switchto = '/adm/switchserver?otherserver='.$otherserver;
+                if (($firsturl) && ($firsturl ne '/adm/switchserver') && ($firsturl ne '/adm/roles')) {
+                    $switchto .= '&origurl='.$firsturl;
+                }
+                if ($form{'role'}) {
+                    $switchto .= '&role='.$form{'role'};
+                }
+                if ($form{'symb'}) {
+                    $switchto .= '&symb='.$form{'symb'};
+                }
+                $r->internal_redirect($switchto);
+            } else {
+                $r->print(&noswitch());
+            }
+            return OK;
+        }
+
+# ------------------------------------------------------- Do the load balancing
+
+# ---------------------------------------------------------- Determine own load
+        my $loadlim = $r->dir_config('lonLoadLim');
+        my $loadavg;
+        {
+            my $loadfile=Apache::File->new('/proc/loadavg');
+            $loadavg=<$loadfile>;
+        }
+        $loadavg =~ s/\s.*//g;
+        my $loadpercent=sprintf("%.1f",100*$loadavg/$loadlim);
+        my $userloadpercent=&Apache::lonnet::userload();
+
+# ---------------------------------------------------------- Are we overloaded?
+        if ((($userloadpercent>100.0)||($loadpercent>100.0))) {
+            my $unloaded=Apache::lonnet::spareserver($loadpercent,$userloadpercent,1,$form{'udom'});
+            if (!$unloaded) {
+                ($unloaded) = &Apache::lonnet::choose_server($form{'udom'});
+            }
+            if ($unloaded) {
+                &success($r,$form{'uname'},$form{'udom'},$authhost,'noredirect',
+                         undef,\%form);
+                $r->internal_redirect('/adm/switchserver?otherserver='.$unloaded.'&origurl='.$firsturl);
+                return OK;
+            }
+        }
+        &success($r,$form{'uname'},$form{'udom'},$authhost,$firsturl,undef,
+                 \%form);
+        return OK;
+    }
+}
+
+sub check_can_host {
+    my ($r,$form,$authhost,$domdesc) = @_;
+    return unless (ref($form) eq 'HASH');
+    my $canhost = 1;
+    my $lonhost = $r->dir_config('lonHostID');
+    my $udom = $form->{'udom'};
+    my @intdoms;
+    my $internet_names = &Apache::lonnet::get_internet_names($lonhost);
+    if (ref($internet_names) eq 'ARRAY') {
+        @intdoms = @{$internet_names};
+    }
+    my $uprimary_id = &Apache::lonnet::domain($udom,'primary');
+    my $uint_dom = &Apache::lonnet::internet_dom($uprimary_id);
+    unless ($uint_dom ne '' && grep(/^\Q$uint_dom\E$/,@intdoms)) {
+        my $machine_dom = &Apache::lonnet::host_domain($lonhost);
+        my $hostname = &Apache::lonnet::hostname($lonhost);
+        my $serverhomeID = &Apache::lonnet::get_server_homeID($hostname);
+        my $serverhomedom = &Apache::lonnet::host_domain($serverhomeID);
+        my %defdomdefaults = &Apache::lonnet::get_domain_defaults($serverhomedom);
+        my %udomdefaults = &Apache::lonnet::get_domain_defaults($udom);
+        my $loncaparev;
+        if ($authhost eq 'no_account_on_host') {
+            $loncaparev = &Apache::lonnet::get_server_loncaparev($machine_dom);
+        } else {
+            $loncaparev = &Apache::lonnet::get_server_loncaparev($machine_dom,$lonhost);
+        }
+        $canhost = &Apache::lonnet::can_host_session($udom,$lonhost,$loncaparev,
+                                                     $udomdefaults{'remotesessions'},
+                                                     $defdomdefaults{'hostedsessions'});
+    }
+    unless ($canhost) {
+        if ($authhost eq 'no_account_on_host') {
+            my $checkloginvia = 1;
+            my ($login_host,$hostname) = 
+                &Apache::lonnet::choose_server($udom,$checkloginvia);
+            &Apache::loncommon::content_type($r,'text/html');
+            $r->send_http_header;
+            if ($login_host ne '') {
+                my $protocol = $Apache::lonnet::protocol{$login_host};
+                $protocol = 'http' if ($protocol ne 'https');
+                my $newurl = $protocol.'://'.$hostname.'/adm/createaccount';
+                $r->print(&Apache::loncommon::start_page('Create a user account in LON-CAPA').
+                          '<h3>'.&mt('Account creation').'</h3>'.
+                          &mt('You do not currently have a LON-CAPA account at this institution.').'<br />'.
+                          '<p>'.&mt('You will be able to create one by logging into a LON-CAPA server within the [_1] domain.',$domdesc).'</p>'.
+                          '<p>'.&mt('[_1]Log in[_2]','<a href="'.$newurl.'">','</a>').
+                          &Apache::loncommon::end_page());
+            } else {
+                $r->print(&Apache::loncommon::start_page('Access to LON-CAPA unavailable').
+                          '<h3>'.&mt('Account creation unavailable').'</h3>'.
+                          &mt('You do not currently have a LON-CAPA account at this institution.').'<br />'.
+                          '<p>'.&mt('Currently a LON-CAPA server is not available within the [_1] domain for you to log-in to, to create an account.',$domdesc).'</p>'.
+                          &Apache::loncommon::end_page());
+            }
+        } else {
+            &success($r,$form->{'uname'},$udom,$authhost,'noredirect',undef,
+                     $form);
+            my ($otherserver) = &Apache::lonnet::choose_server($udom);
+            $r->internal_redirect('/adm/switchserver?otherserver='.$otherserver);
+        }
+    }
+    return $canhost;
+}
+
+sub noswitch {
+    my $result = &Apache::loncommon::start_page('Access to LON-CAPA unavailable').
+                 '<h3>'.&mt('Session unavailable').'</h3>'.
+                 &mt('This LON-CAPA server is unable to host your session.').'<br />'.
+                 '<p>'.&mt('Currently no other LON-CAPA server is available to host your session either.').'</p>'.
+                 &Apache::loncommon::end_page();
+    return $result;
+}
+
+sub loginhelpdisplay {
+    my ($authdomain) = @_;
+    my $login_help = 1;
+    my $lang = &Apache::lonlocal::current_language();
+    if ($login_help) {
+        my $dom = $authdomain;
+        if ($dom eq '') {
+            $dom = &Apache::lonnet::default_login_domain();
+        }
+        my %domconfhash = &Apache::loncommon::get_domainconf($dom);
+        my $loginhelp_url;
+        if ($lang) {
+            $loginhelp_url = $domconfhash{$dom.'.login.helpurl_'.$lang};
+            if ($loginhelp_url ne '') {
+                return $loginhelp_url;
+            }
+        }
+        $loginhelp_url = $domconfhash{$dom.'.login.helpurl_nolang'};
+        if ($loginhelp_url ne '') {
+            return $loginhelp_url;
+        } else {
+            return '/adm/loginproblems.html';
+        }
     }
-    return OK;
+    return;
 }
 
 1;