--- loncom/homework/lonhomework.pm	2003/09/21 21:40:06	1.151
+++ loncom/homework/lonhomework.pm	2003/10/13 21:09:47	1.152
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # The LON-CAPA Homework handler
 #
-# $Id: lonhomework.pm,v 1.151 2003/09/21 21:40:06 www Exp $
+# $Id: lonhomework.pm,v 1.152 2003/10/13 21:09:47 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -147,6 +147,51 @@ sub send_footer {
 
 $Apache::lonxml::browse='';
 
+sub check_ip_acc {
+    my ($acc)=@_;
+    if (!defined($acc)) { return 1; }
+    my $allowed=0;
+    my $ip=$ENV{'REMOTE_ADDR'};
+    my $name;
+    foreach my $pattern (split(',',$acc)) {
+	if ($pattern =~ /\*$/) {
+	    #35.8.*
+	    $pattern=~s/\*//;
+	    if ($ip =~ /^\Q$pattern\E/) { $allowed=1; }
+	} elsif ($pattern =~ /(\d+\.\d+\.\d+)\.\[(\d+)-(\d+)\]$/) {    
+	    #35.8.3.[34-56]
+	    my $low=$2;
+	    my $high=$3;
+	    $pattern=$1;
+	    if ($ip =~ /^\Q$pattern\E/) { 
+		my $last=(split(/\./,$ip))[3];
+		if ($last <=$high && $last >=$low) { $allowed=1; }
+	    }
+	} elsif ($pattern =~ /^\*/) {
+	    #*.msu.edu
+	    $pattern=~s/\*//;
+	    if (!defined($name)) {
+		use Socket;
+		my $netaddr=inet_aton($ip);
+		($name)=gethostbyaddr($netaddr,AF_INET);
+		}
+	    if ($name =~ /\Q$pattern\E$/i) { $allowed=1; }
+	} elsif ($pattern =~ /\d+\.\d+\.\d+\.\d+/) {
+	    #127.0.0.1
+	    if ($ip =~ /^\Q$pattern\E/) { $allowed=1; }
+	} else {
+	    #some.name.com
+	    if (!defined($name)) {
+		use Socket;
+		my $netaddr=inet_aton($ip);
+		($name)=gethostbyaddr($netaddr,AF_INET);
+	    }
+	    if ($name =~ /\Q$pattern\E$/i) { $allowed=1; }
+	}
+	if ($allowed) { last; }
+    }
+    return $allowed;
+}
 # JB, 9/24/2002: Any changes in this function may require a change
 # in lonnavmaps::resource::getDateStatus.
 sub check_access {
@@ -168,6 +213,15 @@ sub check_access {
 
     &Apache::lonxml::debug("checking for part :$id:");
     &Apache::lonxml::debug("time:".time);
+    
+    my $allowed=&check_ip_acc(&Apache::lonnet::EXT("resource.$id.acc"));
+    if (!$allowed) {
+	&Apache::lonnet::logthis("Early exit");
+	$status='INVALID_ACCESS';
+	$date=&mt("may be open from a different computer.");
+	return($status,$date);
+    }
+
     foreach $temp ("opendate","duedate","answerdate") {
 	$lastdate = $date;
 	$date = &Apache::lonnet::EXT("resource.$id.$temp");