--- loncom/lonnet/perl/lonnet.pm	2007/09/29 04:03:51	1.914
+++ loncom/lonnet/perl/lonnet.pm	2007/10/01 23:53:44	1.917
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.914 2007/09/29 04:03:51 albertel Exp $
+# $Id: lonnet.pm,v 1.917 2007/10/01 23:53:44 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -320,7 +320,10 @@ sub convert_and_load_session_env {
     my ($lonidsdir,$handle)=@_;
     my @profile;
     {
-	open(my $idf,"$lonidsdir/$handle.id");
+	my $opened = open(my $idf,'+<',"$lonidsdir/$handle.id");
+	if (!$opened) {
+	    return 0;
+	}
 	flock($idf,LOCK_SH);
 	@profile=<$idf>;
 	close($idf);
@@ -359,7 +362,10 @@ sub transfer_profile_to_env {
 
     my $convert;
     {
-    	open(my $idf,"$lonidsdir/$handle.id");
+    	my $opened = open(my $idf,'+<',"$lonidsdir/$handle.id");
+	if (!$opened) {
+	    return;
+	}
 	flock($idf,LOCK_SH);
 	if (tie(my %disk_env,'GDBM_File',"$lonidsdir/$handle.id",
 		&GDBM_READER(),0640)) {
@@ -391,6 +397,34 @@ sub transfer_profile_to_env {
     }
 }
 
+# ---------------------------------------------------- Check for valid session 
+sub check_for_valid_session {
+    my ($r) = @_;
+    my %cookies=CGI::Cookie->parse($r->header_in('Cookie'));
+    my $lonid=$cookies{'lonID'};
+    return undef if (!$lonid);
+
+    my $handle=&LONCAPA::clean_handle($lonid->value);
+    my $lonidsdir=$r->dir_config('lonIDsDir');
+    return undef if (!-e "$lonidsdir/$handle.id");
+
+    my $opened = open(my $idf,'+<',"$lonidsdir/$handle.id");
+    return undef if (!$opened);
+
+    flock($idf,LOCK_SH);
+    my %disk_env;
+    if (!tie(%disk_env,'GDBM_File',"$lonidsdir/$handle.id",
+	    &GDBM_READER(),0640)) {
+	return undef;	
+    }
+
+    if (!defined($disk_env{'user.name'})
+	|| !defined($disk_env{'user.domain'})) {
+	return undef;
+    }
+    return $handle;
+}
+
 sub timed_flock {
     my ($file,$lock_type) = @_;
     my $failed=0;
@@ -425,8 +459,9 @@ sub appenv {
             $env{$key}=$newenv{$key};
         }
     }
-    open(my $env_file,$env{'user.environment'});
-    if (&timed_flock($env_file,LOCK_EX)
+    my $opened = open(my $env_file,'+<',$env{'user.environment'});
+    if ($opened
+	&& &timed_flock($env_file,LOCK_EX)
 	&&
 	tie(my %disk_env,'GDBM_File',$env{'user.environment'},
 	    (&GDBM_WRITER()|&GDBM_NOLOCK()),0640)) {
@@ -446,16 +481,17 @@ sub delenv {
                 "Attempt to delete from environment ".$delthis);
         return 'error';
     }
-    open(my $env_file,$env{'user.environment'});
-    if (&timed_flock($env_file,LOCK_EX)
+    my $opened = open(my $env_file,'+<',$env{'user.environment'});
+    if ($opened
+	&& &timed_flock($env_file,LOCK_EX)
 	&&
 	tie(my %disk_env,'GDBM_File',$env{'user.environment'},
 	    (&GDBM_WRITER()|&GDBM_NOLOCK()),0640)) {
 	foreach my $key (keys(%disk_env)) {
 	    if ($key=~/^$delthis/) { 
-                delete($env{$key});
-                delete($disk_env{$key});
-            }
+		delete($env{$key});
+		delete($disk_env{$key});
+	    }
 	}
 	untie(%disk_env);
     }