--- loncom/auth/switchserver.pm	2007/09/08 02:43:33	1.16
+++ loncom/auth/switchserver.pm	2020/10/23 21:26:32	1.35.2.3
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # Switch Servers Handler
 #
-# $Id: switchserver.pm,v 1.16 2007/09/08 02:43:33 raeburn Exp $
+# $Id: switchserver.pm,v 1.35.2.3 2020/10/23 21:26:32 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -31,9 +31,10 @@ 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);
 
 sub init_env {
     my ($r) = @_;
@@ -42,35 +43,56 @@ sub init_env {
 	return  $env{'user.environment'};
     }
     my $requrl=$r->uri;
-    my %cookies=CGI::Cookie->parse($r->header_in('Cookie'));
-    my $lonid=$cookies{'lonID'};
-    my $cookie;
-    if (!$lonid) { return undef; }
-
-    my $handle=&LONCAPA::clean_handle($lonid->value);
-    my $lonidsdir=$r->dir_config('lonIDsDir');
-    if ((!-e "$lonidsdir/$handle.id") || ($handle eq '')) {
-	$r->log_reason("Cookie $handle not valid", $r->filename); 
+    my $handle= &Apache::lonnet::check_for_valid_session($r);
+    if ($handle ne '') {
 	return undef;
     }
-
+    my $lonidsdir=$r->dir_config('lonIDsDir');
     &Apache::lonnet::transfer_profile_to_env($lonidsdir,$handle);
-    
+
     return $r->dir_config('lonIDsDir')."/$handle.id";
 }
 
 sub do_redirect {
     my ($r,$url,$only_body,$extra_text) = @_;
     $r->send_http_header;
+    my $delay = 0.5;
+    if ($only_body) {
+        $delay = 0;
+    }
     my $start_page = 
 	&Apache::loncommon::start_page('Switching Server ...',undef,
-				       {'redirect'       => [0.5,$url],
-                                        'no_inline_link' => 1,
+				       {'redirect'       => [$delay,$url],
 					'only_body'      => $only_body,});
     my $end_page   = &Apache::loncommon::end_page();
     $r->print($start_page.$extra_text.$end_page);
+    unless ($env{'user.name'} eq 'public' && ($env{'user.domain'} eq 'public')) {
+        $r->register_cleanup(\&flush_course_logs);
+    }
     return OK;
+}
+
+sub balancer_cookieid {
+    my ($r,$desthost,$uname,$udom) = @_;
+    my @hosts = &Apache::lonnet::current_machine_ids();
+    my $newcookieid;
+    unless (grep(/^\Q$desthost\E$/,@hosts)) {
+        my $balancedir=$r->dir_config('lonBalanceDir');
+        $newcookieid = &md5_hex(&md5_hex(time.{}.rand().$$));
+        my $cookie = $udom.'_'.$uname.'_'.$newcookieid;
+        my $balcookie = "balanceID=$cookie; path=/; HttpOnly;";
+        if (open(my $fh,'>',"$balancedir/$cookie.id")) {
+            print $fh $desthost;
+            close($fh);
+            $r->headers_out->add('Set-cookie' => $balcookie);
+        }
+    }
+    return $newcookieid;
+}
 
+sub flush_course_logs {
+    &Apache::lonnet::flushcourselogs();
+    return OK;
 }
 
 sub handler {
@@ -80,55 +102,169 @@ sub handler {
     if (!defined($handle)) { return FORBIDDEN; }
 
     &Apache::loncommon::get_unprocessed_cgi($ENV{'QUERY_STRING'},
-					    ['otherserver','role']);
+				['otherserver','role','origurl','symb']);
 
     my $switch_to=&Apache::lonnet::hostname($env{'form.otherserver'});
-    if (!$env{'form.otherserver'}) {
-	$env{'form.otherserver'}=&Apache::lonnet::spareserver(30000,undef,1);
+    if (! $env{'form.otherserver'}) {
+	$env{'form.otherserver'} =	
+	    &Apache::lonnet::find_existing_session($env{'user.domain'},
+						   $env{'user.name'});
+	if (! $env{'form.otherserver'}) {
+	    $env{'form.otherserver'} = 
+		&Apache::lonnet::spareserver(30000,undef,1);
+	}
 	$switch_to=&Apache::lonnet::hostname($env{'form.otherserver'});
     }
 
     if (!defined($switch_to)) { return FORBIDDEN; }
 
+    my $protocol = 'http';
+    if ($env{'form.otherserver'}) {
+        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') {
-	my $url = 'http://'.$switch_to.'/'.$r->uri;
+	my $url = $protocol.'://'.$switch_to.$r->uri;
+        unlink($handle);
+        #expire the cookie
+        my $c = new CGI::Cookie(-name    => 'lonPubID',
+                                -value   => '',
+                                -expires => '-10y',);
+        $r->header_out('Set-cookie' => $c);
 	return &do_redirect($r,$url,1)
     }
 
-    if ($env{'form.role'} && 
-	!exists($env{'user.role.'.$env{'form.role'}})) { return FORBIDDEN; }
+    my $skip_canhost_check = '';
+    my $now = time;
+    if ($env{'form.role'}) {
+        if (!exists($env{'user.role.'.$env{'form.role'}})) {
+            delete($env{'form.role'});
+        } else {
+            my ($start,$end) = split(/\./,$env{'user.role.'.$env{'form.role'}});
+            if (($start && $start > $now) || ($end && $end < $now)) {
+                delete($env{'form.role'});
+            } elsif ($env{'form.role'} eq 'au./'.$env{'user.domain'}.'/') {
+                if (&Apache::lonnet::homeserver($env{'user.name'},$env{'user.domain'}) eq $env{'form.otherserver'}) {
+                    $skip_canhost_check = 1;
+                }
+            } elsif ($env{'form.role'} =~ m{^[ac]a\./($match_domain)/($match_username)$}) {
+                if (&Apache::lonnet::homeserver($2,$1) eq $env{'form.otherserver'}) {
+                    $skip_canhost_check = 1; 
+                }
+            }
+        }
+    }
+
+    unless ($skip_canhost_check) {
+        my $canhost = 1;
+        my $uprimary_id = &Apache::lonnet::domain($env{'user.domain'},'primary');
+        my $uint_dom = &Apache::lonnet::internet_dom($uprimary_id);
+        my @intdoms;
+        my $internet_names = &Apache::lonnet::get_internet_names($env{'form.otherserver'});
+        if (ref($internet_names) eq 'ARRAY') {
+            @intdoms = @{$internet_names};
+        }
+        unless ($uint_dom ne '' && grep(/^\Q$uint_dom\E$/,@intdoms)) {
+            my $serverhomeID = &Apache::lonnet::get_server_homeID($switch_to);
+            my $serverhomedom = &Apache::lonnet::host_domain($serverhomeID);
+            my %defdomdefaults = &Apache::lonnet::get_domain_defaults($serverhomedom);
+            my %udomdefaults = &Apache::lonnet::get_domain_defaults($env{'user.domain'});
+            my $remoterev = &Apache::lonnet::get_server_loncaparev($env{'user.domain'},$env{'form.otherserver'});
+            $canhost = 
+                &Apache::lonnet::can_host_session($env{'user.domain'},
+                                                  $env{'form.otherserver'},
+                                                  $remoterev,
+                                                  $udomdefaults{'remotesessions'},
+                                                  $defdomdefaults{'hostedsessions'});
+        }
+        unless ($canhost) { return FORBIDDEN; }
+    }
 
     #remove session env, and log event
-    unlink($handle);
-    my %temp=('switchserver' => time.':'.$env{'form.otherserver'},
+    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' => $now.':'.$env{'form.otherserver'},
 	      $env{'form.role'});
     &Apache::lonnet::put('email_status',\%temp);
+    my $logmsg = "Switch Server to $env{'form.otherserver'}";
+    if ($env{'form.role'}) {
+        $logmsg .= " with role: $env{'form.role'}";
+    } else {
+        $logmsg .= " (no role)";
+    }
+    $logmsg .= ' '.$ENV{'REMOTE_ADDR'};
     &Apache::lonnet::log($env{'user.domain'},$env{'user.name'},
-			 $env{'user.home'},
-			 "Switch Server to $env{'form.otherserver'} with role $env{'form.role'} $ENV{'REMOTE_ADDR'}");
+			 $env{'user.home'},$logmsg);
 
     &Apache::loncommon::content_type($r,'text/html');
 
-    #expire the cookie
-    my $c = new CGI::Cookie(-name    => 'lonID',
-			    -value   => '',
-			    -expires => '-10y',);
-    $r->header_out('Set-cookie' => $c);
-    $r->send_http_header;
-    return OK if $r->header_only;
+    #expire the cookies
+    my %cookies=CGI::Cookie->parse($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;
+    }
 # -------------------------------------------------------- Menu script and info
-	   
-    my $windowinfo=
-	&Apache::lonmenu::close().
-	&Apache::lonnavmaps::close();
+
 # ---------------------------------------------------------------- Get handover
 
+    my ($is_balancer,$setcookie,$newcookieid);
+    my $only_body = 0;
+    ($is_balancer,undef,$setcookie) =
+        &Apache::lonnet::check_loadbalancing($env{'user.name'},$env{'user.domain'},'switchserver');
+    if ($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);
+
+        if (($found_server eq $env{'form.otherserver'}) &&
+            ($balancer_cookie =~ /^\Q$env{'user.domain'}\E_\Q$env{'user.name'}\E_/)) {
+            $only_body = 1;
+        } else {
+            $newcookieid = &balancer_cookieid($r,$env{'form.otherserver'},
+                                              $env{'user.name'},$env{'user.domain'});
+        }
+    }
+    if ((!$is_balancer) && ($env{'request.balancercookie'})) {
+        $otherbalcookie = $env{'request.balancercookie'};
+    }
+
     my %info=('ip'       => $ENV{'REMOTE_ADDR'},
 	      'domain'   => $env{'user.domain'},
 	      'username' => $env{'user.name'},
 	      'role'     => $env{'form.role'},
-	      'server'   => $r->dir_config('lonHostID'));
+	      'server'   => $r->dir_config('lonHostID'),
+	      'balancer' => $is_balancer);
+    if ($newcookieid) {
+        $info{'balcookie'} = $newcookieid;
+    } elsif ($otherbalcookie) {
+        $info{'otherbalcookie'} = $otherbalcookie;
+    }
+    if ($env{'form.origurl'}) {
+        $info{'origurl'} = $env{'form.origurl'};
+    }
+    if ($env{'form.symb'}) {
+        $info{'symb'} = $env{'form.symb'};
+    }
     if ($env{'request.sso.login'}) {
 	$info{'sso.login'} = $env{'request.sso.login'};
     }
@@ -136,13 +272,12 @@ sub handler {
         $info{'sso.reloginserver'} = $env{'request.sso.reloginserver'};
     }
     my $token = &Apache::lonnet::tmpput(\%info,$env{'form.otherserver'});
-    my $url ='http://'.$switch_to.'/adm/login?'.
+    my $url =$protocol.'://'.$switch_to.'/adm/login?'.
 	'domain='.$env{'user.domain'}.
-	'&username='.$env{'user.name'}.
-	'&token='.$token;
+	'&amp;username='.$env{'user.name'}.
+	'&amp;token='.$token;
 # --------------------------------------------------------------- Screen Output
-    &Apache::lonnet::flushcourselogs();
-    return &do_redirect($r,$url,0,$windowinfo);
+    return &do_redirect($r, $url, $only_body);
 }
 
 1;