--- loncom/auth/migrateuser.pm	2018/03/23 01:01:29	1.27
+++ loncom/auth/migrateuser.pm	2022/06/18 02:10:18	1.61
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # Starts a user off based of an existing token.
 #
-# $Id: migrateuser.pm,v 1.27 2018/03/23 01:01:29 raeburn Exp $
+# $Id: migrateuser.pm,v 1.61 2022/06/18 02:10:18 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -30,12 +30,15 @@ package Apache::migrateuser;
 
 use strict;
 use LONCAPA qw(:DEFAULT :match);
-use Apache::Constants qw(:common :http :methods);
+use Apache::Constants qw(:common :http :methods :remotehost);
 use Apache::lonauth;
 use Apache::lonnet;
+use Apache::loncommon;
 use Apache::lonlocal;
 use Apache::lonlogin();
 use Apache::ltiauth;
+use Apache::switchserver;
+use CGI::Cookie;
 
 sub goto_login {
     my ($r,$domain,$data) = @_;
@@ -87,6 +90,15 @@ sub lti_check {
             if ($data->{'lti.selfenrollrole'}) {
                 $lti_env{'request.lti.selfenrollrole'} = $data->{'lti.selfenrollrole'};
             }
+            if ($data->{'lti.uri'}) {
+                $lti_env{'request.lti.uri'} = $data->{'lti.uri'};
+            }
+            if ($data->{'lti.target'}) {
+                $lti_env{'request.lti.target'} = $data->{'lti.target'};
+            }
+            if ($data->{'lti.sourcecrs'}) {
+                $lti_env{'request.lti.sourcecrs'} = $data->{'lti.sourcecrs'};
+            }
         }
         if ($data->{'lti.passbackid'}) {
             $lti_env{'request.lti.passbackid'} = $data->{'lti.passbackid'};
@@ -104,8 +116,50 @@ sub lti_check {
     return \%lti_env;
 }
 
+sub canhost {
+    my ($uname,$udom,$lonhost,$loncaparev) = @_;
+    my $canhost;
+    if (&Apache::lonnet::is_library($lonhost)) {
+        my @possdoms = &Apache::lonnet::current_machine_domains();
+        my %roleshash = &Apache::lonnet::get_my_roles($uname,$udom,'userroles','',['ca','aa'],\@possdoms);
+        if (keys(%roleshash)) {
+            foreach my $key (keys(%roleshash)) {
+                my $audom = (split(/:/,$key))[1];
+                if ((&Apache::lonnet::will_trust('othcoau',$udom,$audom)) &&
+                    (&Apache::lonnet::will_trust('coaurem',$audom,$udom))) {
+                    $canhost = 1;
+                    last;
+                }
+            }
+        }
+    }
+    unless ($canhost) {
+        my $uprimary_id = &Apache::lonnet::domain($udom,'primary');
+        my $uint_dom = &Apache::lonnet::internet_dom($uprimary_id);
+        my @intdoms;
+        my $internet_names = &Apache::lonnet::get_internet_names($lonhost);
+        if (ref($internet_names) eq 'ARRAY') {
+            @intdoms = @{$internet_names};
+        }
+        if ($uint_dom ne '' && grep(/^\Q$uint_dom\E$/,@intdoms)) {
+            $canhost = 1;
+        } else {
+            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);
+            $canhost =
+                &Apache::lonnet::can_host_session($udom,$lonhost,$loncaparev,
+                                                  $udomdefaults{'remotesessions'},
+                                                  $defdomdefaults{'hostedsessions'});
+        }
+    }
+    return $canhost;
+}
+
 sub ip_changed {
-    my ($r,$udom,$camefrom,$dataref) = @_;
+    my ($r,$udom,$camefrom,$idsref,$dataref) = @_;
     &Apache::loncommon::content_type($r,'text/html');
     $r->send_http_header;
     if (ref($dataref) eq 'HASH') {
@@ -154,8 +208,10 @@ sub ip_changed {
         my $lonhost= $r->dir_config('lonHostID');
         my $switchto = $lonhost;
         if ($rule_in_effect ne 'offloadedto') {
-            my $hosthere;
-            my @ids=&Apache::lonnet::current_machine_ids();
+            my ($hosthere,@ids);
+            if (ref($idsref) eq 'ARRAY') {
+                @ids=@{$idsref};
+            }
             unless ($rule_in_effect eq 'balancer') {
                 if (grep(/^\Q$rule_in_effect\E$/,@ids)) {
                     $hosthere = 1;
@@ -197,6 +253,8 @@ sub ip_changed {
                 if ($hostname) {
                     my $protocol = $Apache::lonnet::protocol{$switchto};
                     $protocol = 'http' if ($protocol ne 'https');
+                    my $alias = &Apache::lonnet::use_proxy_alias($r,$switchto);
+                    $hostname = $alias if ($alias ne '');
                     $url = $protocol.'://'.$hostname;
                     if ($rule_in_effect eq 'balancer') {
                         $message .= '<br />'.
@@ -207,6 +265,11 @@ sub ip_changed {
                     }
                 }
             }
+            unless ($hosthere) {
+                if (($dataref->{'balancer'}) && ($dataref->{'balcookie'})) {
+                    &Apache::lonnet::delbalcookie($dataref->{'balcookie'},$dataref->{'balancer'});
+                }
+            }
         }
         if ($dataref->{'sso.login'}) {
             $url .= '/adm/roles';
@@ -220,19 +283,17 @@ sub ip_changed {
         my %info= (
                     'domain'          => $udom,
                     'username'        => $dataref->{'username'},
-                    'role'            => $dataref->{'role'},
                     'sessionserver'   => $lonhost,
                   );
-        if ($dataref->{'origurl'}) {
-            $info{'origurl'} = $dataref->{'origurl'};
-        }
-        if ($dataref->{'symb'}) {
-            $info{'symb'} = $dataref->{'symb'};
+        my @names = ('origurl','symb','role','linkprotuser','linkprot','linkkey');
+        foreach my $name (@names) {
+            if ($dataref->{$name} ne '') {
+                $info{$name} = $dataref->{$name};
+            }
         }
-        my $iptoken = &Apache::lonnet::tmpput(\%info,$switchto);
+        my $iptoken = &Apache::lonnet::tmpput(\%info,$switchto,'link');
         unless ($iptoken eq 'conlost') {
-            $url .= ($url =~ /\?/) ? '&' : '?';
-            $url .= 'iptoken='.$iptoken;
+            $url .= (($url =~ /\?/) ? '&' : '?') . 'iptoken='.$iptoken;
         }
         $r->print(&Apache::loncommon::start_page($title,undef,
                                                  {'redirect' =>
@@ -246,6 +307,282 @@ sub ip_changed {
     return OK;
 }
 
+sub logout {
+    my ($r,$ip,$handle,$data,$lti_env,$linkprot_info) = @_;
+    my $lonidsdir=$r->dir_config('lonIDsDir');
+    if (unlink("$lonidsdir/$handle.id")) {
+        if (($env{'user.linkedenv'} =~ /^[a-f0-9]+_linked$/) &&
+            (-l "$lonidsdir/$env{'user.linkedenv'}.id") &&
+            (readlink("$lonidsdir/$env{'user.linkedenv'}.id") eq "$lonidsdir/$handle.id")) {
+            unlink("$lonidsdir/$env{'user.linkedenv'}.id");
+        }
+    }
+    my %temp=('logout' => time);
+    &Apache::lonnet::put('email_status',\%temp);
+    &Apache::lonnet::log($env{'user.domain'},
+                         $env{'user.name'},
+                         $env{'user.home'},
+                         "Logout $ip");
+
+    &Apache::loncommon::content_type($r,'text/html');
+
+    #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);
+    }
+    my $lonhost = $r->dir_config('lonHostID');
+    my ($url,$token,%info,%user_info);
+    if (ref($data) eq 'HASH') {
+        %user_info=('ip'       => $ip,
+                    'domain'   => $data->{'domain'},
+                    'username' => $data->{'username'},
+                    'home'     => $data->{'home'},
+                    'role'     => $data->{'role'},
+                    'origurl'  => $data->{'origurl'},
+                    'symb'     => $data->{'symb'},
+                    'server'   => $lonhost);
+    }
+    if (ref($linkprot_info) eq 'HASH') {
+        if ($linkprot_info->{'linkprotuser'} ne '') {
+            $token = &Apache::lonnet::tmpput($linkprot_info,$lonhost);
+            $url = '/adm/login?ltoken='.$token;
+        } else {
+            foreach my $key (keys(%user_info)) {
+                if ($user_info{$key} eq '') {
+                    delete($user_info{$key});
+                }
+            }
+            %info = (%user_info,%{$linkprot_info});
+            $token = &Apache::lonnet::tmpput(\%info,$lonhost);
+            $url = '/adm/migrateuser?token='.$token;
+        }
+    } else {
+        my %lti_info;
+        if (ref($lti_env) eq 'HASH') {
+            foreach my $key (sort(keys(%{$lti_env}))) {
+                if ($key =~ /^request\.(.+)$/) {
+                    $lti_info{$1} = $lti_env->{$key};
+                }
+            }
+        }
+        %info = (%user_info,%lti_info);
+        $token = &Apache::lonnet::tmpput(\%info,$lonhost);
+        $url = '/adm/migrateuser?token='.$token;
+    }
+    $r->send_http_header;
+    $r->print(
+        &Apache::loncommon::start_page('Updating Session ...',undef,
+                                       {'redirect'       => [0.1,$url],
+                                        'only_body'      => 1,}).
+        &Apache::loncommon::end_page());
+    if ($env{'request.balancercookie'}) {
+        my ($balancer,$cookie) = split(/:/,$env{'request.balancercookie'});
+        if ((&Apache::lonnet::hostname($balancer)) && ($cookie =~ /^[a-f0-9]{32}$/)) {
+            $cookie = $env{'user.domain'}.'_'.$env{'user.name'}.'_'.$cookie;
+            &Apache::lonnet::delbalcookie($cookie,$balancer);
+        }
+    }
+    $r->register_cleanup(\&flush_course_logs);
+    return;
+}
+
+sub conlost_userhome {
+    my ($r,$idsref,$dataref) = @_;
+    return unless ((ref($idsref) eq 'ARRAY') && (ref($dataref) eq 'HASH'));
+    my @ids = @{$idsref};
+    my %data = %{$dataref};
+    my ($lonhost,$lowest_load,$otherserver,$is_balancer,%conlost,%posstargets);
+    $lonhost = $r->dir_config('lonHostID');
+    if (grep(/^\Q$lonhost\E$/,split(/,/,$data{'dom_balancers'}))) {
+        $is_balancer = 1;
+    }
+    $lowest_load = 30000;
+    if ($data{'conlost'} ne '') {
+        map { $conlost{$_} = 1; } split(/,/,$data{'conlost'});
+    }
+    if ($data{'loncfail'}) {
+        if ($lonhost ne $data{'from_balancer'}) {
+            my ($is_balancer,$posshost,$setcookie,$offloadto,$dom_balancers) =
+                &Apache::lonnet::check_loadbalancing($data{'username'},$data{'domain'});
+            if ($is_balancer) {
+                if (ref($offloadto) eq 'HASH') {
+                    $data{'offloadto'} = '';
+                    foreach my $key (keys(%{$offloadto})) {
+                        if (ref($offloadto->{$key}) eq 'ARRAY') {
+                            $data{'offloadto'} .= $key.'='.join(',',@{$offloadto->{$key}}).'&';
+                        }
+                    }
+                    $data{'offloadto'} =~ s/\&$//;
+                } elsif (ref($offloadto) eq 'ARRAY') {
+                    $data{'offloadto'} = join(',',@{$offloadto});
+                }
+            }
+        }
+    } else {
+        $conlost{$lonhost} = 1;
+        $data{'conlost'} = join(',',sort(keys(%conlost)));
+    }
+    if ($data{'offloadto'} =~ /\&/) {
+        foreach my $item (split(/\&/,$data{'offloadto'})) {
+            my ($type,$targets) = split(/\=/,$item);
+            @{$posstargets{$type}} = split(/,/,$targets);
+        }
+    } elsif ($data{'offloadto'} =~ /=/) {
+        my ($type,$targets) = split(/\=/,$data{'offloadto'});
+        @{$posstargets{$type}} = split(/,/,$targets);
+    } else {
+        @{$posstargets{'default'}} = split(/,/,$data{'offloadto'});
+    }
+    if (ref($posstargets{'primary'}) eq 'ARRAY') {
+        foreach my $try_server (@{$posstargets{'primary'}}) {
+            next if ($conlost{$try_server});
+            next if ((grep(/^\Q$try_server\E$/,@ids)) && !$data{'loncfail'});
+            ($otherserver,$lowest_load) =
+                &Apache::lonnet::compare_server_load($try_server,
+                                                     $otherserver,
+                                                     $lowest_load);
+        }
+    }
+    my $found_server = ($otherserver ne '' && $lowest_load < 100);
+    if (!$found_server) {
+        if (ref($posstargets{'default'}) eq 'ARRAY') {
+            foreach my $try_server (@{$posstargets{'default'}}) {
+                next if ($conlost{$try_server});
+                next if ((grep(/^\Q$try_server\E$/,@ids)) && !$data{'loncfail'});
+                ($otherserver,$lowest_load) =
+                    &Apache::lonnet::compare_server_load($try_server,
+                                                         $otherserver,
+                                                         $lowest_load);
+            }
+        }
+    }
+    if ($otherserver ne '') {
+        my $switchto = &Apache::lonnet::hostname($otherserver);
+        if ($switchto ne '') {
+            $data{'server'} = $lonhost;
+            if ($data{'loncfail'}) {
+                delete($data{'loncfail'});
+            }
+            if (grep(/^\Q$otherserver\E$/,split(/,/,$data{'dom_balancers'}))) {
+                $data{'noloadbalance'} = $otherserver;
+            }
+            &do_server_switch($r,$otherserver,$switchto,$is_balancer,\%data);
+            return $otherserver;
+        } else {
+            #FIXME Contents of $data{offloadto} contains invalid hostID.
+        }
+    } else {
+        my (%poss_balancers,%tried_balancers);
+        map { $poss_balancers{$_} = 1; } split(/,/,$data{'dom_balancers'});
+        map { $tried_balancers{$_} = 1; } split(/,/,$data{'tried_balancers'});
+        if (keys(%poss_balancers)) {
+            foreach my $try_server (sort(keys(%poss_balancers))) {
+                next if (grep(/^\Q$try_server\E$/,@ids));
+                next if (($data{'loncfail'}) && ($tried_balancers{$try_server}));
+                my $alreadytried;
+                foreach my $key (keys(%posstargets)) {
+                    if ((ref($posstargets{$key}) eq 'ARRAY') &&
+                        (grep(/^\Q$try_server\E$/,@{$posstargets{$key}}))) {
+                        $alreadytried = 1;
+                        last;
+                    }
+                }
+                unless ($alreadytried) {
+                    if (&Apache::lonnet::reply('ping',$try_server) eq $try_server) {
+                        $otherserver = $try_server;
+                        last;
+                    }
+                }
+            }
+        }
+        if ($otherserver ne '') {
+            my $switchto = &Apache::lonnet::hostname($otherserver);
+            if ($switchto ne '') {
+                $data{'server'} = $lonhost;
+                $data{'loncfail'} = $lonhost;
+                $tried_balancers{$otherserver} = 1;
+                $data{'tried_balancers'} = join(',',sort(keys(%tried_balancers)));
+                &do_server_switch($r,$otherserver,$switchto,$is_balancer,\%data);
+                return $otherserver;
+            } else {
+                #FIXME Contents of $data{'dom_balancers'} contains invalid hostID.
+            }
+        } else {
+            if ($data{'loncfail'}) {
+                #FIXME Nowhere to go. 
+            } else {
+                # FIXME Send back to a balancer (no token); different balancer if this is a balancer.
+                # Send command to balancer to exclude this host using http instead on lonc/lond
+            }
+        }
+    }
+    return;
+}
+
+sub do_server_switch {
+    my ($r,$otherserver,$switchto,$is_balancer,$dataref) = @_;
+    if (ref($dataref) eq 'HASH') {
+        my $domain = $dataref->{'domain'};
+        my $username = $dataref->{'username'};
+        # If this is a balancer set a balancer cookie unless browser already sent
+        # LON-CAPA load balancer cookie which points at the target server.
+        if ($is_balancer) {
+            my $newcookieid;
+            my ($found_server,$balancer_cookie) = &Apache::lonnet::check_for_balancer_cookie($r,1);
+            unless (($found_server eq $otherserver) &&
+                    ($balancer_cookie =~ /^\Q$domain\E_\Q$username\E_/)) {
+                $newcookieid =
+                    &Apache::switchserver::balancer_cookieid($r,$otherserver,$username,$domain);
+                if ($newcookieid) {
+                    $dataref->{'balcookie'} = $newcookieid;
+                }
+            }
+        }
+        my $token = &Apache::lonnet::tmpput($dataref,$otherserver);
+        my $protocol = $Apache::lonnet::protocol{$otherserver};
+        $protocol = 'http' if ($protocol ne 'https');
+        my $url = $protocol.'://'.$switchto.'/adm/login?domain='.$domain.
+                                 '&amp;username='.$username.'&amp;token='.$token;
+        $r->send_http_header;
+        $r->print(
+        &Apache::loncommon::start_page('Switching Server ...',undef,
+                                       {'redirect'       => [0.1,$url]}).
+        &Apache::loncommon::end_page());
+    }
+    return;
+}
+
+sub log_switch {
+    my ($r,$data,$lti_env,$ip) = @_;
+    my $lonhost = $r->dir_config('lonHostID');
+    return unless ((ref($data) eq 'HASH') && (ref($lti_env) eq 'HASH'));
+    my $now = time;
+    my %temp=('switchserver' => $now.':'.$lonhost,$data->{'role'});
+    &Apache::lonnet::put('email_status',\%temp);
+    my $logmsg = "Switch Server to $lonhost";
+    if ($data->{'role'}) {
+        $logmsg .= " with role: ".$data->{'role'};
+    } elsif (($lti_env->{'reqcrs'}) && ($lti_env->{'reqrole'} eq 'cc')) {
+        $logmsg .= " to create new LTI course";
+    } elsif ($lti_env->{'selfenrollrole'}) {
+        $logmsg .= " to selfenroll with role: ".$lti_env->{'selfenrollrole'};
+    } else {
+        $logmsg .= " (no role)";
+    }
+    $logmsg .= ' '.$ip;
+    &Apache::lonnet::log($data->{'domain'},$data->{'username'},$data->{'home'},$logmsg);
+}
+
+sub flush_course_logs {
+    &Apache::lonnet::flushcourselogs();
+    return OK;
+}
+
 sub handler {
     my ($r) = @_;
     
@@ -265,19 +602,65 @@ sub handler {
     if (!defined($data{'username'}) || !defined($data{'domain'})) {
         return &goto_login($r,undef,\%data);
     }
-    if ($data{'ip'} ne $ENV{'REMOTE_ADDR'}) {
+    my ($home,@ids);
+    @ids=&Apache::lonnet::current_machine_ids();
+    my $ip = &Apache::lonnet::get_requestor_ip($r,REMOTE_NOLOOKUP); 
+    if ($data{'ip'} ne $ip) {
         &Apache::lonnet::logthis('IP change when session migration requested -- was: '.
-                 $data{'ip'}.'; now: '.$ENV{'REMOTE_ADDR'}.' for '.$data{'username'}.':'.$data{'domain'});
-	return &ip_changed($r,$data{'domain'},$data{'server'},\%data);
+                 $data{'ip'}.'; now: '.$ip.' for '.$data{'username'}.':'.$data{'domain'});
+	return &ip_changed($r,$data{'domain'},$data{'server'},\@ids,\%data);
+    }
+    if ($data{'loncfail'}) {
+        &Apache::lonnet::logthis('Returned from '.$data{'server'}.' -- no connection to library node or other access node(s)');
+        my $otherserver = &conlost_userhome($r,\@ids,\%data);
+        if ($otherserver ne '') {
+            &Apache::lonnet::logthis("Switching to $otherserver");
+        }
+        return OK;
+    } else {
+        $home=&Apache::lonnet::homeserver($data{'username'},$data{'domain'});
+        if ($home eq 'no_host') {
+            if (($data{'home'} ne '') && (&Apache::lonnet::hostname($data{'home'}))) {
+                &Apache::lonnet::reconlonc($data{'home'});
+                $home=&Apache::lonnet::homeserver($data{'username'},$data{'domain'});
+                if ($home eq 'no_host') {
+                    unless (grep(/^\Q$data{'home'}\E$/,@ids)) {
+                        if (&Apache::lonnet::reply('ping',$data{'home'}) eq 'con_lost') {
+                            my $otherserver = &conlost_userhome($r,\@ids,\%data);
+                            if ($otherserver ne '') {
+                                &Apache::lonnet::logthis("No connection to home server ($data{'home'}) for $data{'username'}:$data{'domain'}. Switching to $otherserver");
+                            }
+                            return OK;
+                        }
+                    }
+                }
+            }
+        }
     }
 
-    &Apache::lonnet::logthis("Allowing access for $data{'username'}:$data{'domain'} to $data{'role'}");
-    my $home=&Apache::lonnet::homeserver($data{'username'},$data{'domain'});
     my $udom;
     if (&Apache::lonnet::domain($data{'domain'})) {
         $udom=$data{'domain'};
     }
-    if ($home =~ /(con_lost|no_such_host)/) { return &goto_login($r,$udom,\%data); }
+    if ($home eq 'no_host') { return &goto_login($r,$udom,\%data); }
+    if (&Apache::lonnet::hostname($home) eq '') { return &goto_login($r,$udom,\%data); }
+
+    unless (grep(/^\Q$home\E$/,@ids)) {
+        my $lonhost = $r->dir_config('lonHostID');
+        my $loncaparev = $r->dir_config('lonVersion');
+        unless (&canhost($data{'username'},$data{'domain'},$lonhost,$loncaparev)) {
+            return &goto_login($r,$udom,\%data);
+        }
+    }
+
+    my $rolemsg;
+    if ($data{'role'}) {
+        $rolemsg = "role: $data{'role'}";
+    } else {
+        $rolemsg = '(no role)';
+    }
+
+    &Apache::lonnet::logthis("Allowing access for $data{'username'}:$data{'domain'} $rolemsg");
 
     my $sso_env = &sso_check(\%data);
     my $lti_env = &lti_check(\%data);
@@ -288,8 +671,39 @@ sub handler {
     } elsif ((ref($lti_env) eq 'HASH') && (keys(%{$lti_env}))) {
         $extra_env = $lti_env;
     }
+    if (($data{'balancer'}) && ($data{'server'}) && ($data{'balcookie'})) {
+        if (ref($extra_env) eq 'HASH') {
+            $extra_env->{'request.balancercookie'} = $data{'server'}.':'.$data{'balcookie'};
+        } else {
+            $extra_env = { 'request.balancercookie' => $data{'server'}.':'.$data{'balcookie'} };
+        }
+    } elsif (($data{'server'}) && ($data{'otherbalcookie'})) {
+        my ($balancer,$balcookie) = split(/:/,$data{'otherbalcookie'});
+        if (defined(&Apache::lonnet::hostname($balancer)) && $balcookie =~ /^[a-f0-9]{32}$/) {
+            my $baldom = &Apache::lonnet::host_domain($balancer);
+            if (&Apache::lonnet::shared_institution($baldom)) {
+                my $cookieid = join('_',$udom,$data{'username'},$balcookie);
+                &Apache::lonnet::updatebalcookie($cookieid,$balancer,$data{'server'});
+                if (ref($extra_env) eq 'HASH') {
+                    $extra_env->{'request.balancercookie'} = $data{'otherbalcookie'};
+                } else {
+                    $extra_env = { 'request.balancercookie' => $data{'otherbalcookie'} };
+                }
+            }
+        }
+    }
 
-    my %form;
+    if (($data{'conlost'}) && ($data{'server'})) {
+        my @conlosts = split(/,/,$data{'conlost'});
+        my $switchfrom = $data{'server'};
+        if (@conlosts) {
+            if (grep(/^\Q$switchfrom\E$/,@conlosts)) {
+                &log_switch($r,\%data,$extra_env,$ip);
+            }
+        }
+    }
+
+    my (%form,$cid);
     if ($data{'symb'} ne '') {
         $form{'symb'} = $data{'symb'};
     }
@@ -299,44 +713,207 @@ sub handler {
     if ($data{'noloadbalance'} ne '') {
         $form{'noloadbalance'} = $data{'noloadbalance'};
     }
+    if ($data{'role'}) {
+        if ($data{'role'} =~ m{\./($match_domain)/($match_courseid)(?:/\w+|$)}) {
+            unless (&Apache::lonnet::homeserver($2,$1) eq 'no_host') {
+                $cid = $1.'_'.$2;
+            }
+        }
+    } else {
+        my ($handle,$expirepub);
+        $handle = &Apache::lonnet::check_for_valid_session($r);
 
-    if (!$data{'role'}) {
-	my $handle = &Apache::lonnet::check_for_valid_session($r);
+# For "public user" - remove any existing "public" cookie so actual user is logged in.
+        if ($handle) {
+            if ($handle=~/^publicuser\_/) {
+                my $lonidsdir=$r->dir_config('lonIDsDir');
+                if ($lonidsdir ne '') {
+                    unlink("$lonidsdir/$handle.id");
+                }
+                undef($handle);
+                $expirepub = 1;
+            }
+        }
 	if ($handle) {
 	    &Apache::lonnet::transfer_profile_to_env($r->dir_config('lonIDsDir'),
 						     $handle);
-#FIXME if user is not currently logged in as an LTI log-in log them out.
+            my $checklaunch;
+            if ($data{'origurl'} =~ m{^/tiny/$match_domain/\w+$}) {
+                unless ($env{'request.linkprot'} eq $data{'linkprot'}) {
+                    $checklaunch = 1;
+                }
+                unless ($env{'request.linkkey'} eq $data{'linkkey'}) {
+                    $checklaunch = 1;
+                }
+                unless ($env{'request.deeplink.login'} eq $data{'deeplink.login'}) {
+                    $checklaunch = 1;
+                }
+            }
+            if ($data{'linkprot'} ne '') {
+                if (($env{'user.name'} ne $data{'username'}) ||
+                    ($env{'user.domain'} ne $data{'domain'})) {
+                    my %linkprot_env;
+                    foreach my $item ('linkprot','deeplink.login') {
+                        if ($data{$item}) {
+                            $linkprot_env{$item} = $data{$item};
+                        }
+                    }
+                    &logout($r,$ip,$handle,\%data,undef,\%linkprot_env);
+                    return OK;
+                }
+                &Apache::lonnet::appenv({'request.linkprot' => $data{'linkprot'}});
+                if ($env{'request.linkkey'}) {
+                    &Apache::lonnet::delenv('request.linkkey');
+                }
+                my ($linkprotector,$deeplink) = split(/:/,$data{'linkprot'},2);
+                if ($env{'user.linkprotector'}) {
+                    my @protectors = split(/,/,$env{'user.linkprotector'});
+                    unless (grep(/^\Q$linkprotector\E$/,@protectors)) {
+                        push(@protectors,$linkprotector);
+                        @protectors = sort { $a <=> $b } @protectors;
+                        &Apache::lonnet::appenv({'user.linkprotector' => join(',',@protectors)});
+                    }
+                } else {
+                    &Apache::lonnet::appenv({'user.linkprotector' => $linkprotector });
+                }
+                if ($env{'user.linkproturi'}) {
+                    my @proturis = split(/,/,$env{'user.linkproturi'});
+                    unless(grep(/^\Q$deeplink\E$/,@proturis)) {
+                        push(@proturis,$deeplink);
+                        @proturis = sort @proturis;
+                        &Apache::lonnet::appenv({'user.linkproturi' => join(',',@proturis)});
+                    }
+                } else {
+                    &Apache::lonnet::appenv({'user.linkproturi' => $deeplink});
+                }
+            } elsif ($data{'linkkey'} ne '') {
+                &Apache::lonnet::appenv({'request.linkkey' => $data{'linkkey'}});
+                if ($env{'request.linkprot'}) {
+                    &Apache::lonnet::delenv('request.linkprot');
+                }
+                my $deeplink = $data{'deeplink.login'};
+                my $linkkey = $data{'linkkey'};
+                if ($env{'user.deeplinkkey'} ne '') {
+                    my @linkkeys = split(/,/,$env{'user.deeplinkkey'});
+                    unless (grep(/^\Q$linkkey\E$/,@linkkeys)) {
+                        push(@linkkeys,$linkkey);
+                        &Apache::lonnet::appenv({'user.deeplinkkey' => join(',',sort(@linkkeys))});
+                    }
+                } else {
+                    &Apache::lonnet::appenv({'user.deeplinkkey' => $linkkey});
+                }
+                if ($deeplink) {
+                    if ($env{'user.keyedlinkuri'}) {
+                        my @keyeduris = split(/,/,$env{'user.keyedlinkuri'});
+                        unless (grep(/^\Q$deeplink\E$/,@keyeduris)) {
+                            push(@keyeduris,$deeplink);
+                            &Apache::lonnet::appenv({'user.keyedlinkuri' => join(',',sort(@keyeduris))});
+                        }
+                    } else {
+                        &Apache::lonnet::appenv({'user.keyedlinkuri' => $deeplink});
+                    }
+                }
+            }
+            if ($data{'deeplink.login'}) {
+                &Apache::lonnet::appenv({'request.deeplink.login' => $data{'deeplink.login'}});
+            }
             if ($data{'lti.login'}) {
-                if (($data{'lti.reqcrs'}) && ($data{'lti.reqrole'} eq 'cc')) {
+                my $needslogout;
+                if ($env{'request.lti.login'}) {
+                    if (($env{'user.name'} ne $data{'username'}) ||
+                        ($env{'user.domain'} ne $data{'domain'})) {
+                        $needslogout = 1;
+                    }
+                } else {
+                    $needslogout = 1;
+                }
+# If access is via LTI, and user already has a non-LTI session cookie 
+# (and session) or has an LTI session cookie for a different username,
+# logout the existing session, and start a new one
+                if ($needslogout) {
+                    &logout($r,$ip,$handle,\%data,$lti_env);
+                } elsif (($data{'lti.reqcrs'}) && ($data{'lti.reqrole'} eq 'cc')) {
                     $form{'lti.reqcrs'} = $data{'lti.reqcrs'};
                     $form{'lti.reqrole'} = $data{'lti.reqrole'};
                     $form{'lti.sourcecrs'} = $data{'lti.sourcecrs'};
+                    $form{'lti.uri'} = $data{'lti.uri'};
+                    if ($data{'lti.passbackid'}) {
+                        $form{'lti.passbackid'} = $data{'lti.passbackid'};
+                    }
+                    if ($data{'lti.passbackurl'}) {
+                        $form{'lti.passbackurl'} = $data{'lti.passbackurl'};
+                    }
+                    if ($data{'lti.rosterid'}) {
+                        $form{'lti.rosterid'} = $data{'lti.rosterid'};
+                    }
+                    if ($data{'lti.rosterurl'}) {
+                        $form{'lti.rosterurl'} = $data{'lti.rosterurl'};
+                    }
+                    if ($data{'lti.target'}) {
+                        $form{'lti.target'} = $data{'lti.target'};
+                    }
                     &Apache::loncommon::content_type($r,'text/html');
                     $r->send_http_header;
                     &Apache::ltiauth::lti_reqcrs($r,$data{'domain'},\%form,$data{'username'},$data{'domain'});
-                } elsif ($data{'lti.selfenrollrole'}) {
-                    if (&Apache::ltiauth::lti_enroll($data{'username'},data{'domain'},
-                                                 $data{'lti.selfenrollrole'}) eq 'ok') {
-                        my $url = '/adm/roles?selectrole=1&'.
-                                  &escape($data{'lti.selfenrollrole'}).'=1';
-                        if ($data{'origurl'} =~ m{/default_\d+\.sequence$}) {
-                            $url .= '&orgurl='.$data{'origurl'}.'&navmap=1';
-                        } elsif ($data{'origurl'} ne '') {
-                            $url .= '&orgurl='.$data{'origurl'};
+                } else {
+                    if (ref($lti_env) eq 'HASH') {
+                        delete($lti_env->{'reqcrs'});
+                        delete($lti_env->{'reqrole'});
+                        delete($lti_env->{'selfenrollrole'});
+                    }
+                    if ($data{'lti.selfenrollrole'}) {
+                        if (&Apache::ltiauth::lti_enroll($data{'username'},$data{'domain'},
+                                                         $data{'lti.selfenrollrole'}) eq 'ok') {
+                            my $url = '/adm/roles?selectrole=1&'.
+                                      &escape($data{'lti.selfenrollrole'}).'=1';
+                            if ($data{'origurl'} =~ m{/default_\d+\.sequence$}) {
+                                $url .= '&orgurl='.$data{'origurl'}.'&navmap=1';
+                            } elsif ($data{'origurl'} ne '') {
+                                $url .= '&orgurl='.$data{'origurl'};
+                            }
+                            if (ref($lti_env) eq 'HASH') {
+                                &Apache::lonnet::appenv($lti_env);
+                            }
+                            $r->internal_redirect($url);
+                        } else {
+                            &Apache::ltiauth::invalid_request($r,23);
+                        }
+                    } elsif ($data{'origurl'} ne '') {
+                        my $url = $data{'origurl'};
+                        if ($url =~ m{/default_\d+\.sequence$}) {
+                            $url .= (($url =~/\?/)?'&':'?').'navmap=1';
+                        }
+                        if (ref($lti_env) eq 'HASH') {
+                            &Apache::lonnet::appenv($lti_env);
                         }
                         $r->internal_redirect($url);
                     } else {
-                        &Apache::ltiauth::invalid_request($r,23);
-                    }
-                } elsif ($data{'origurl'} ne '') {
-                    my $url = $data{'origurl'};
-                    if ($url =~ m{/default_\d+\.sequence$}) {
-                        $url .= (($url =~/\?/)?'&':'?').'navmap=1';
+                        if (ref($lti_env) eq 'HASH') {
+                            &Apache::lonnet::appenv($lti_env);
+                        }
                     }
-                    $r->internal_redirect($url);
                 }
             } elsif ($data{'origurl'} ne '') {
-                $r->internal_redirect($data{'origurl'});
+                my $dest = $data{'origurl'};
+                if (($env{'request.deeplink.login'} eq $data{'origurl'}) &&
+                    (($env{'request.linkprot'}) || ($env{'request.linkkey'} ne ''))) {
+                    my %info;
+                    if ($env{'request.linkprot'}) {
+                        $info{'linkprot'} = $env{'request.linkprot'};
+                    } elsif ($env{'request.linkkey'} ne '') {
+                        $info{'linkkey'} = $env{'request.linkkey'};
+                    }
+                    $info{'origurl'} = $data{'origurl'};
+                    if ($checklaunch) {
+                        $info{'checklaunch'} = 1;
+                    }
+                    my $token = &Apache::lonnet::tmpput(\%info,$r->dir_config('lonHostID'),'link');
+                    unless (($token eq 'con_lost') || ($token eq 'refused') || ($token =~ /^error:/) ||
+                            ($token eq 'unknown_cmd') || ($token eq 'no_such_host')) {
+                        $dest .= (($dest =~ /\?/) ? '&' : '?') . 'ttoken='.$token;
+                    }
+                }
+                $r->internal_redirect($dest);
             } elsif ($env{'request.course.id'}) {
                 $r->internal_redirect('/adm/navmaps');
 	    } else {
@@ -344,32 +921,141 @@ sub handler {
 	    }
 	} else {
             my $desturl = '/adm/roles';
-            if ($data{'origurl'} ne '') {
-                $desturl = $data{'origurl'};
-                if ($data{'lti.login'}) {
-                    $desturl = $data{'origurl'};
+            if ($data{'lti.login'}) {
+                if ($data{'lti.selfenrollrole'}) {
+                    $desturl .= '?selectrole=1&'.
+                                &escape($data{'lti.selfenrollrole'}).'=1';
+                    if ($data{'origurl'} ne '') {
+                        $desturl .= '&orgurl='.$data{'origurl'};
+                        if ($data{'origurl'} =~ m{/default_\d+\.sequence$}) {
+                            $desturl .= '&navmap=1';
+                        }  
+                    }
+                } elsif ($data{'origurl'} ne '') {
+                    $desturl = $data{'origurl'}; 
                     if ($desturl =~ m{/default_\d+\.sequence$}) {
                         $desturl .= (($desturl =~/\?/)?'&':'?').'navmap=1';
                     }
                 }
+            } elsif ($data{'origurl'} ne '') {
+                $desturl = $data{'origurl'};
+                if ($data{'linkprot'}) {
+                    my ($linkprotector,$linkuri) = split(/:/,$data{'linkprot'},2);
+                    if ($linkprotector) {
+                        if (ref($extra_env) eq 'HASH') {
+                            $extra_env->{'user.linkprotector'} = $linkprotector;
+                            $extra_env->{'user.linkproturi'} = $linkuri;
+                            $extra_env->{'request.linkprot'} = $data{'linkprot'};
+                        } else {
+                            $extra_env = {'user.linkprotector' => $linkprotector,
+                                          'user.linkproturi' => $linkuri,
+                                          'request.linkprot' => $data{'linkprot'}};
+                        }
+                    }
+                } elsif ($data{'linkkey'} ne '') {
+                    if (ref($extra_env) eq 'HASH') {
+                        $extra_env->{'user.deeplinkkey'} = $data{'linkkey'};
+                        $extra_env->{'user.keyedlinkuri'} = $data{'deeplink.login'};
+                        $extra_env->{'request.linkkey'} = $data{'linkkey'};
+                     } else {
+                        $extra_env = {'user.deeplinkkey' => $data{'linkkey'},
+                                      'user.keyedlinkuri' => $data{'deeplink.login'},
+                                      'request.linkkey' => $data{'linkkey'}};
+                    }
+                }
+                if ($data{'deeplink.login'}) {
+                   if (ref($extra_env) eq 'HASH') {
+                        $extra_env->{'request.deeplink.login'} = $data{'deeplink.login'};
+                    } else {
+                        $extra_env = {'request.deeplink.login' => $data{'deeplink.login'}};
+                    }
+                }
             }
             my $skipcritical;
-            if (($data{'lti.login'}) && ($data{'lti.reqcrs'}) &&
-                ($data{'lti.reqrole'} eq 'cc')) {
-                $skipcritical = 1;
+            if ($data{'lti.login'}) {
+                if ((($data{'lti.reqcrs'}) &&
+                     ($data{'lti.reqrole'} eq 'cc')) ||
+                    ($data{'lti.selfenrollrole'})) {
+                    $skipcritical = 1;
+                }
             }
 	    &Apache::lonauth::success($r,$data{'username'},$data{'domain'},
-				      $home,$desturl,$extra_env,\%form,$skipcritical);
+				      $home,$desturl,$extra_env,\%form,$skipcritical,'',
+                                      $expirepub);
 	}
 	return OK;
     }
 
-    my $next_url='/adm/roles?selectrole=1&amp;'.&escape($data{'role'}).'=1';
-    if ($data{'origurl'} ne '') {
-        $next_url .= '&amp;orgurl='.&escape($data{'origurl'});
+    if ($data{'lti.login'}) {
+        my $handle = &Apache::lonnet::check_for_valid_session($r);
+        if ($handle) {
+            &Apache::lonnet::transfer_profile_to_env($r->dir_config('lonIDsDir'),
+                                                     $handle);
+            my $needslogout;
+            if ($env{'request.lti.login'}) {
+                if (($env{'user.name'} ne $data{'username'}) ||
+                    ($env{'user.domain'} ne $data{'domain'})) {
+                    $needslogout = 1;
+                }
+            } else {
+                $needslogout = 1;
+            }
+            if ($needslogout) {
+                &logout($r,$ip,$handle,\%data,$lti_env);
+                return OK;
+            }
+        }
+    }
+
+# check if current user, and role match those expected.
+    my ($next_url,$reuse_session);
+    if (($env{'user.name'} eq $data{'username'}) && ($env{'user.domain'} eq $data{'domain'}) &&
+        ($env{'request.role'} eq $data{'role'}) && ($data{'origurl'} ne '')) {
+        $next_url = $data{'origurl'};
+        $reuse_session = 1;
+    } elsif ($data{'origurl'} =~ m{^/tiny/$match_domain/\w+$}) {
+        $next_url=$data{'origurl'};
+    } else {
+        if ($data{'lti.login'}) {
+            $next_url='/adm/roles?selectrole=1&'.&escape($data{'role'}).'=1';
+            if ($data{'origurl'} ne '') {
+                $next_url .= '&orgurl='.&escape($data{'origurl'});
+            }
+        } else {
+            $next_url='/adm/roles?selectrole=1&amp;'.&escape($data{'role'}).'=1';
+            if ($data{'origurl'} ne '') {
+                $next_url .= '&amp;orgurl='.&escape($data{'origurl'});
+            }
+        }
+    }
+    if ($data{'lti.login'}) {
+        if (($data{'origurl'} =~ m{/default_\d+\.sequence$}) ||
+            ($data{'origurl'} =~ m{^/res/.+\.sequence$})) {
+            if ($reuse_session) {
+                $next_url .= '&amp;navmap=1';
+            } else {
+                $next_url .= '&navmap=1';
+            }
+        }
+    }
+    if ($reuse_session) {
+        $r->internal_redirect($next_url);
+    } else {
+        if ($data{'deeplink.login'}) {
+            if (ref($extra_env) eq 'HASH') {
+                $extra_env->{'request.deeplink.login'} = $data{'deeplink.login'};
+            } else {
+                $extra_env = {'request.deeplink.login' => $data{'deeplink.login'}};
+            }
+            if ($data{'linkprot'}) {
+                $extra_env->{'request.linkprot'} = $data{'linkprot'};
+            } elsif ($data{'linkkey'} ne '') {
+                $extra_env->{'request.linkkey'} = $data{'linkkey'};
+            }
+        }
+        &Apache::lonauth::success($r,$data{'username'},$data{'domain'},$home,
+                                  $next_url,$extra_env,\%form,'',$cid);
     }
-    &Apache::lonauth::success($r,$data{'username'},$data{'domain'},$home,
-			      $next_url,$extra_env,\%form);
     return OK;
 }