--- loncom/auth/switchserver.pm	2018/04/14 02:30:11	1.40
+++ loncom/auth/switchserver.pm	2018/12/02 13:52:56	1.44
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # Switch Servers Handler
 #
-# $Id: switchserver.pm,v 1.40 2018/04/14 02:30:11 raeburn Exp $
+# $Id: switchserver.pm,v 1.44 2018/12/02 13:52:56 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -31,7 +31,7 @@ package Apache::switchserver;
 use strict;
 use Apache::Constants qw(:common);
 use Apache::lonnet;
-use Apache::lonmenu;
+use Digest::MD5 qw(md5_hex);
 use CGI::Cookie();
 use Apache::lonlocal;
 use LONCAPA qw(:DEFAULT :match);
@@ -49,7 +49,7 @@ sub init_env {
     }
     my $lonidsdir=$r->dir_config('lonIDsDir');
     &Apache::lonnet::transfer_profile_to_env($lonidsdir,$handle);
-    
+
     return $r->dir_config('lonIDsDir')."/$handle.id";
 }
 
@@ -101,7 +101,7 @@ sub handler {
         if ($Apache::lonnet::protocol{$env{'form.otherserver'}} eq 'https') {
             $protocol = $Apache::lonnet::protocol{$env{'form.otherserver'}};
         }
-    } 
+    }
 
     if ($env{'user.name'} eq 'public'
 	&& $env{'user.domain'} eq 'public') {
@@ -166,15 +166,18 @@ sub handler {
     }
 
     #remove session env, and log event
-    unlink($handle);
-    if ($env{'user.linkedenv'} ne '') {
-        my $lonidsdir=$r->dir_config('lonIDsDir');
-        if ((-l $env{'user.linkedenv'}) &&
-            (readlink($env{'user.linkedenv'}) eq "$lonidsdir/$handle.id")) {
-            unlink($env{'user.linkedenv'});
+    if (unlink($handle)) {
+        if ($env{'user.linkedenv'} ne '') {
+            my $lonidsdir=$r->dir_config('lonIDsDir');
+            if (($env{'user.linkedenv'} =~ /^[a-f0-9]+_linked$/) &&
+                (-l "$lonidsdir/$env{'user.linkedenv'}.id") &&
+                (readlink("$lonidsdir/$env{'user.linkedenv'}.id") eq $handle)) {
+                unlink("$lonidsdir/$env{'user.linkedenv'}.id");
+            }
         }
     }
-    my %temp=('switchserver' => time.':'.$env{'form.otherserver'},
+    my $now = time;
+    my %temp=('switchserver' => $now.':'.$env{'form.otherserver'},
 	      $env{'form.role'});
     &Apache::lonnet::put('email_status',\%temp);
     my $logmsg = "Switch Server to $env{'form.otherserver'}";
@@ -193,18 +196,15 @@ sub handler {
 
     &Apache::loncommon::content_type($r,'text/html');
 
-    #expire the cookie
-    my $c = new CGI::Cookie(-name    => 'lonID',
-			    -value   => '',
-			    -expires => '-10y',);
-    $r->headers_out->add('Set-cookie' => $c);
-    if ($env{'user.linkedenv'}) {
-        my $linked = new CGI::Cookie(-name    => 'lonLinkID',
-                                     -value   => '',
-                                     -expires => '-10y',);
-        $r->headers_out->add('Set-cookie' => $linked);
+    #expire the cookies
+    my %cookies=CGI::Cookie->parse($r->header_in('Cookie'));
+    foreach my $name (keys(%cookies)) {
+        next unless ($name =~ /^lon(|S|Link|Pub)ID$/);
+        my $c = new CGI::Cookie(-name    => $name,
+                                -value   => '',
+                                -expires => '-10y',);
+        $r->headers_out->add('Set-cookie' => $c);
     }
-
     if ($r->header_only) {
 	$r->send_http_header;
 	return OK;
@@ -213,13 +213,55 @@ sub handler {
 	   
 # ---------------------------------------------------------------- Get handover
 
-    my ($is_balancer) = &Apache::lonnet::check_loadbalancing($env{'user.name'},$env{'user.domain'});
-    my %info=('ip'       => $ENV{'REMOTE_ADDR'},
-	      'domain'   => $env{'user.domain'},
-	      'username' => $env{'user.name'},
-	      'role'     => $env{'form.role'},
-	      'server'   => $r->dir_config('lonHostID'),
-	      'balancer' => $is_balancer);
+    my $newcookieid;
+    my ($is_balancer,$posshost,$setcookie,$offloadto,$dom_balancers) =
+        &Apache::lonnet::check_loadbalancing($env{'user.name'},$env{'user.domain'});
+    if ($is_balancer && $setcookie && $env{'form.otherserver'}) {
+
+        # Set a balancer cookie unless browser already sent LON-CAPA load balancer
+        # cookie which points at the target server
+        my ($found_server,$balancer_cookie) = &Apache::lonnet::check_for_balancer_cookie($r,1);
+
+        unless (($found_server eq $env{'form.otherserver'}) &&
+                ($balancer_cookie =~ /^\Q$env{'user.domain'}\E_\Q$env{'user.name'}\E_/)) {
+            my @hosts = &Apache::lonnet::current_machine_ids();
+            my $desthost = $env{'form.otherserver'};
+            unless (grep(/^\Q$desthost\E$/,@hosts)) {
+                my $balancedir=$r->dir_config('lonBalanceDir');
+                $newcookieid = &md5_hex(&md5_hex($now.{}.rand().$$));
+                my $cookie = $env{'user.domain'}.'_'.$env{'user.name'}.'_'.$newcookieid;
+                my $balcookie = "balanceID=$cookie; path=/; HttpOnly;";
+                if (open(my $fh,'>',"$balancedir/$cookie.id")) {
+                    print $fh $env{'form.otherserver'};
+                    close($fh);
+                }
+                $r->headers_out->add('Set-cookie' => $balcookie);
+            }
+        }
+    }
+
+    my %info=('ip'            => $ENV{'REMOTE_ADDR'},
+              'domain'        => $env{'user.domain'},
+              'username'      => $env{'user.name'},
+              'home'          => $env{'user.home'},
+              'role'          => $env{'form.role'},
+              'server'        => $r->dir_config('lonHostID'),
+              'balancer'      => $is_balancer,
+              'dom_balancers' => $dom_balancers,
+              'offloadto'     => '');
+    if (ref($offloadto) eq 'HASH') {
+        foreach my $key (keys(%{$offloadto})) {
+            if (ref($offloadto->{$key}) eq 'ARRAY') {
+                $info{'offloadto'} .= $key.'='.join(',',@{$offloadto->{$key}}).'&';
+            }
+        }
+        $info{'offloadto'} =~ s/\&$//;
+    } elsif (ref($offloadto) eq 'ARRAY') {
+        $info{'offloadto'} = join(',',@{$offloadto});
+    }
+    if ($newcookieid) {
+        $info{'balcookie'} = $newcookieid;
+    }
     if ($env{'form.origurl'}) {
         $info{'origurl'} = $env{'form.origurl'};
     }
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>500 Internal Server Error</title>
</head><body>
<h1>Internal Server Error</h1>
<p>The server encountered an internal error or
misconfiguration and was unable to complete
your request.</p>
<p>Please contact the server administrator at 
 root@localhost to inform them of the time this error occurred,
 and the actions you performed just before this error.</p>
<p>More information about this error may be available
in the server error log.</p>
</body></html>