# The LearningOnline Network
# Starts a user off based of an existing token.
#
# $Id: migrateuser.pm,v 1.55 2021/11/17 00:44:47 raeburn Exp $
#
# Copyright Michigan State University Board of Trustees
#
# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
#
# LON-CAPA is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# LON-CAPA is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with LON-CAPA; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# /home/httpd/html/adm/gpl.txt
#
# http://www.lon-capa.org/
#

package Apache::migrateuser;

use strict;
use LONCAPA qw(:DEFAULT :match);
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,$data) = @_;
    if ((ref($data) eq 'HASH') && ($data->{'lti.login'})) {
        &Apache::ltiauth::invalid_request($r,'22');
    } else {
        &Apache::loncommon::content_type($r,'text/html');
        $r->send_http_header;
        my $url = '/adm/login';
        if ($domain) {
            $url .= '?domain='.$domain;
        }
        $r->print(&Apache::loncommon::start_page('Going to login',undef,
					         {'redirect' => [0,$url],}).
	          '<h1>'.&mt('One moment please...').'</h1>'.
	          '<p>'.&mt('Transferring to login page.').'</p>'.
	          &Apache::loncommon::end_page());
    }
    return OK;
}

sub sso_check {
    my ($data) = @_;
    my %extra_env;
    if (ref($data) eq 'HASH') {
        if ($data->{'sso.login'}) {
            $extra_env{'request.sso.login'} = $data->{'sso.login'};
        }
        if ($data->{'sso.reloginserver'}) {
            $extra_env{'request.sso.reloginserver'} = 
                $data->{'sso.reloginserver'};
        }
    }
    return \%extra_env;
}

sub lti_check {
    my ($data) = @_;
    my %lti_env;
    if (ref($data) eq 'HASH') {
        if ($data->{'lti.login'}) {
            $lti_env{'request.lti.login'} = $data->{'lti.login'};
            if ($data->{'lti.reqcrs'}) {
                $lti_env{'request.lti.reqcrs'} = $data->{'lti.reqcrs'};
            }
            if ($data->{'lti.reqrole'}) {
                $lti_env{'request.lti.reqrole'} = $data->{'lti.reqrole'};
            }
            if ($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'} = $data->{'lti.passbackid'};
        }
        if ($data->{'lti.passbackurl'}) {
            $lti_env{'request.lti.passbackurl'} = $data->{'lti.passbackurl'};
        }
        if ($data->{'lti.rosterid'}) {
            $lti_env{'request.lti.rosterid'} = $data->{'lti.rosterid'};
        }
        if ($data->{'lti.rosterurl'}) {
            $lti_env{'request.lti.rosterurl'} = $data->{'lti.rosterurl'};
        }
    }
    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,$camefrom,$idsref,$dataref) = @_;
    &Apache::loncommon::content_type($r,'text/html');
    $r->send_http_header;
    if (ref($dataref) eq 'HASH') {
        my $title = 'LON-CAPA Session redirected';
        my $message = &mt('Your internet address has changed since you logged in.');  
        my $rule_in_effect;
        if ($dataref->{'balancer'}) {
            my $baldom = &Apache::lonnet::host_domain($camefrom);
            my $balprimaryid = &Apache::lonnet::domain($baldom,'primary');
            my $balintdom = &Apache::lonnet::internet_dom($balprimaryid);
            my $uprimaryid = &Apache::lonnet::domain($udom,'primary'); 
            my $uintdom = &Apache::lonnet::internet_dom($uprimaryid);
            my $dom_in_use;
            if (($uintdom ne '') && ($uintdom eq $balintdom)) {
                $dom_in_use = $udom;
            } else {
                $dom_in_use = $baldom;
            }
            my ($result,$cached)=&Apache::lonnet::is_cached_new('loadbalancing',$dom_in_use);
            unless (defined($cached)) {
                my $cachetime = 60*60*24; 
                my %domconfig =
                    &Apache::lonnet::get_dom('configuration',['loadbalancing'],$dom_in_use);
                if (ref($domconfig{'loadbalancing'}) eq 'HASH') {
                    $result = &Apache::lonnet::do_cache_new('loadbalancing',$dom_in_use,
                                                            $domconfig{'loadbalancing'},$cachetime);
                }
            }
            if (ref($result) eq 'HASH') {
                (undef,my $currtargets,my $currrules) =
                    &Apache::lonnet::check_balancer_result($result,$dataref->{'server'});
                if (ref($currrules) eq 'HASH') {
                    if ($dataref->{'sso.login'}) {
                        if ($currrules->{'_LC_ipchangesso'} ne '') {
                            $rule_in_effect = $currrules->{'_LC_ipchangesso'};
                        }
                    } else {
                        if ($currrules->{'_LC_ipchange'} ne '') {
                            $rule_in_effect = $currrules->{'_LC_ipchange'};
                        }
                    }
                }
            }
        }
        my $url;
        my $lonhost= $r->dir_config('lonHostID');
        my $switchto = $lonhost;
        if ($rule_in_effect ne 'offloadedto') {
            my ($hosthere,@ids);
            if (ref($idsref) eq 'ARRAY') {
                @ids=@{$idsref};
            }
            unless ($rule_in_effect eq 'balancer') {
                if (grep(/^\Q$rule_in_effect\E$/,@ids)) {
                    $hosthere = 1;
                }
            }
            unless ($hosthere) {
                if ($dataref->{'role'}) {
                    my ($adom,$aname);
                    if ($dataref->{'role'} =~ m{^au\./($match_domain)/$}) {
                        $adom = $1;
                        $aname = $dataref->{'username'};
                    } elsif ($dataref->{'role'} =~ m{^(?:ca|aa)\./($match_domain)/($match_username)$}) {
                        $adom = $1;
                        $aname = $2;
                    }
                    if ($adom ne '' && $aname ne '') {
                        my $ahome = &Apache::lonnet::homeserver($aname,$adom);
                        unless ($ahome eq 'no_host') {
                            if ($ahome && grep(/^\Q$ahome\E$/,@ids)) {
                                $hosthere = 1;
                            }
                        }
                    }
                }
            }
            unless ($hosthere) {
                my $hostname;
                if ($rule_in_effect eq 'balancer') {
                    $hostname = &Apache::lonnet::hostname($dataref->{'server'});
                    if ($hostname) {
                        $switchto = $dataref->{'server'};
                    }
                } else {
                    $hostname = &Apache::lonnet::hostname($rule_in_effect);
                    if ($hostname) {
                        $switchto = $rule_in_effect;
                    }
                }
                if ($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 />'.
                                    &mt('As a result, your LON-CAPA session is being redirected to the server where you originally logged in.');
                    } else {
                        $message .= '<br />'.
                                    &mt('As a result, your LON-CAPA session is being redirected.');
                    }
                }
            }
            unless ($hosthere) {
                if (($dataref->{'balancer'}) && ($dataref->{'balcookie'})) {
                    &Apache::lonnet::delbalcookie($dataref->{'balcookie'},$dataref->{'balancer'});
                }
            }
        }
        if ($dataref->{'sso.login'}) {
            $url .= '/adm/roles';
        } else {
            $url .= '/adm/login';
            if ($udom) {
                $url .= '?domain='.$udom;
            }
            $message .= '<br />'.&mt('You will need to provide your password one more time.');
        }
        my %info= (
                    'domain'          => $udom,
                    'username'        => $dataref->{'username'},
                    'sessionserver'   => $lonhost,
                  );
        my @names = ('origurl','symb','role','linkprot','linkkey');
        foreach my $name (@names) {
            if ($dataref->{$name} ne '') {
                $info{$name} = $dataref->{$name};
            }
        }
        my $iptoken = &Apache::lonnet::tmpput(\%info,$switchto,'link');
        unless ($iptoken eq 'conlost') {
            $url .= (($url =~ /\?/) ? '&' : '?') . 'iptoken='.$iptoken;
        }
        $r->print(&Apache::loncommon::start_page($title,undef,
                                                 {'redirect' =>
                                                  [2,$url],}).
                  '<h1>'.&mt('One moment please...').'</h1>'.
                  '<p class="LC_warning">'.$message.'</p>'.
                  &Apache::loncommon::end_page());
    } else {
        return &goto_login($r);
    }
    return OK;
}

sub logout {
    my ($r,$ip,$handle,$data,$lti_env) = @_;
    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' => $c);
    }
    my (%info,%user_info,%lti_info);
    if (ref($lti_env) eq 'HASH') {
        foreach my $key (sort(keys(%{$lti_env}))) {
            if ($key =~ /^request\.(.+)$/) {
                $lti_info{$1} = $lti_env->{$key};
            }
        }
    }
    my $lonhost = $r->dir_config('lonHostID');
    if (ref($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);
    }
    %info = (%user_info,%lti_info);
    my $token = &Apache::lonnet::tmpput(\%info,$lonhost);
    my $url = '/adm/migrateuser?token='.$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) = @_;
    
    &Apache::loncommon::get_unprocessed_cgi($ENV{'QUERY_STRING'},['token']);
    my %data =   &Apache::lonnet::tmpget($env{'form.token'});
    if (keys(%data) == 0) {
        return &goto_login($r);
    }
    my $delete = &Apache::lonnet::tmpdel($env{'form.token'});

    &Apache::lonlocal::get_language_handle($r);

    if ($delete ne 'ok') {
	return &goto_login($r,undef,\%data);
    }

    if (!defined($data{'username'}) || !defined($data{'domain'})) {
        return &goto_login($r,undef,\%data);
    }
    my ($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: '.
                 $data{'ip'}.'; now: '.$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;
                        }
                    }
                }
            }
        }
    }

    my $udom;
    if (&Apache::lonnet::domain($data{'domain'})) {
        $udom=$data{'domain'};
    }
    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);

    my $extra_env;
    if ((ref($sso_env) eq 'HASH') && (keys(%{$sso_env}))) {
        $extra_env = $sso_env;
    } elsif ((ref($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'} };
                }
            }
        }
    }

    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'} = $data{'symb'};
    }
    if ($data{'iptoken'} ne '') {
        $form{'iptoken'} = $data{'iptoken'};
    }
    if ($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);

# For "public user" - remove any exising "public" cookie so actual user is ogged 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);
            my $checklaunch;
            if ($data{'origurl'} =~ m{^/tiny/$match_domain/\w+$}) {
                if ($env{'request.linkprot'} ne '') {
                     unless ($env{'request.linkprot'} eq $data{'linkprot'}) {
                         $checklaunch = 1;
                     }
                }
                if ($env{'request.linkkey'} ne '') {
                    unless ($env{'request.linkkey'} eq $data{'linkkey'}) {
                        $checklaunch = 1;
                    }
                }
                if ($env{'request.deeplink.login'}) {
                    unless ($env{'request.deeplink.login'} eq $data{'deeplink.login'}) {
                        $checklaunch = 1;
                    }
                }
            }
            if ($data{'linkprot'} ne '') {
                &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'}) {
                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'},$data{'domain'});
                } else {
                    if (ref($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 {
                        if (ref($lti_env) eq 'HASH') {
                            &Apache::lonnet::appenv($lti_env);
                        }
                    }
                }
            } elsif ($data{'origurl'} ne '') {
                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') ||
                            ($token eq 'unknown_cmd') || ($token eq 'no_such_host')) {
                        $dest .= (($dest =~ /\?/) ? '&' : '?') . 'ttoken='.$token;
                    }
                }
                $r->internal_redirect($dest);
            } elsif ($env{'request.course.id'}) {
                $r->internal_redirect('/adm/navmaps');
	    } else {
		$r->internal_redirect('/adm/roles');
	    }
	} else {
            my $desturl = '/adm/roles';
            if ($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'}) {
                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,'',
                                      $expirepub);
	}
	return OK;
    }

    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 {
        $next_url='/adm/roles?selectrole=1&amp;'.&escape($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$})) {
            $next_url .= '&amp;navmap=1';
        }
    }
    if ($reuse_session) {
        $r->internal_redirect($next_url);
    } elsif ($data{'deeplink.login'}) {
        if (ref($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);
    }
    return OK;
}

1;
__END__
<!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>