--- loncom/auth/lonracc.pm	1999/10/13 17:48:52	1.1.1.1
+++ loncom/auth/lonracc.pm	2020/12/18 15:23:03	1.24
@@ -1,43 +1,144 @@
 # The LearningOnline Network
 # Access Handler for File Transfers
-# (lonacc: Cookie Based Access Handler
-# 5/21/99,5/22,5/29,5/31,6/15 Gerd Kortemeyer)
-# 6/16,6/18,7/3 Gerd Kortemeyer
+#
+# $Id: lonracc.pm,v 1.24 2020/12/18 15:23:03 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/
+#
+
+=pod
+
+=head1 NAME
+
+Apache::lonracc - Access Handler for File Transfers
+
+=head1 SYNOPSIS
+
+Invoked by /etc/httpd/conf/loncapa.conf:
+
+ <LocationMatch "^/raw.*">
+ PerlAccessHandler Apache::lonracc
+ </LocationMatch>
+
+=head1 INTRODUCTION
+
+This module enables authentication for file transfers and works
+against the /res tree.
+
+Only lond invokes the /raw namespace through its subscribe function.
+
+This is part of the LearningOnline Network with CAPA project
+described at http://www.lon-capa.org.
+
+=head1 HANDLER SUBROUTINE
+
+This routine is called by Apache and mod_perl.
+
+=over 4
+
+=item *
+
+Determine requesting host
+
+=item *
+
+See whether or not the requesting host is subscribed.
+
+=item *
+
+Respond with status of request and make log entry in case of unallowed
+access.
+
+=back
+
+=cut
 
 package Apache::lonracc;
 
 use strict;
 use Apache::Constants qw(:common :remotehost);
+use Apache::lonnet;
 use Apache::File();
+use IO::Socket;
+
+sub subscribed {
+    my ($filename,$id) = @_;
+
+    return 0 if (!-e "$filename.subscription");
+
+    my $hostname=&Apache::lonnet::hostname($id);
+    my (undef,undef,undef,undef,$ip) = gethostbyname($hostname);
+    
+    return 0 if (length($ip) != 4);
+
+    $ip=inet_ntoa($ip);
+
+    my $expr='^'.quotemeta($id).':'.quotemeta($ip).':';
+
+    my $found=0;
+    if (my $sh=Apache::File->new("$filename.subscription")) {
+	while (my $subline=<$sh>) { if ($subline =~ /$expr/) { $found=1; } }
+	$sh->close();
+    }
+    return $found;
+}
 
 sub handler {
     my $r = shift;
-    my $reqhost;
-    unless ($reqhost=$r->get_remote_host(REMOTE_DOUBLE_REV)) {
-       $r->log_reason("Spoof request");
-       return FORBIDDEN;
-    }
-    my $readline;
-    my $lontabdir=$r->dir_config('lonTabDir');
-    {
-       my $fh;
-       unless ($fh=Apache::File->new("$lontabdir/hosts.tab")) {
-          $r->log_reason("Could not find host tab file");
-          return FORBIDDEN;
-       }
-       while ($readline=<$fh>) {
-          my ($id,$domain,$role,$name,$ip)=split(/:/,$readline);
-          if ($name =~ /$reqhost/i) {
-              my $filename=$r->filename;
-              if (-e "$filename.$id") {
-	         return OK;
-              } else {
-                 $r->log_reason("$id not subscribed", $r->filename);
-                 return FORBIDDEN;
-              }
-          }
-       }
 
+    my $filename=$r->filename;
+    if (!-e $filename) {
+	return NOT_FOUND;
+    }
+
+    my $reqhost = &Apache::lonnet::get_requestor_ip($r,REMOTE_NOLOOKUP,1);
+    my @hostids= &Apache::lonnet::get_hosts_from_ip($reqhost);
+    if (!@hostids && $reqhost ne '127.0.0.1' ) {
+	$r->log_reason("Unable to find a host for ".
+		       $r->get_remote_host(REMOTE_NOLOOKUP));
+	return FORBIDDEN;
+    }
+    if ($reqhost eq '127.0.0.1') {
+	return OK;
+    }
+    my $return;
+    my @ids;
+
+    foreach my $id (@hostids) {
+	my $uri =$r->uri;
+	if (($filename=~/\.meta$/) ||
+	    ($uri=~m|^/raw/uploaded|) ||
+	    (-e "$filename.$id") ||
+	    &subscribed($filename,$id) ) {
+	    return OK;
+	} else {
+	    $return=FORBIDDEN;
+	    push(@ids,$id);
+	}
+    }
+    if ($return == FORBIDDEN) {
+	$r->log_reason(join(':',@ids)." not subscribed", $r->filename);
+	return FORBIDDEN;
     }
     $r->log_reason("Invalid request for file transfer from $reqhost", 
                    $r->filename); 
@@ -49,6 +150,7 @@ __END__
 
 
 
+