--- loncom/lonnet/perl/lonnet.pm	2013/01/03 19:59:47	1.1172.2.16
+++ loncom/lonnet/perl/lonnet.pm	2013/02/02 03:30:24	1.1172.2.17
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.1172.2.16 2013/01/03 19:59:47 raeburn Exp $
+# $Id: lonnet.pm,v 1.1172.2.17 2013/02/02 03:30:24 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -11513,12 +11513,12 @@ sub goodbye {
 }
 
 sub get_dns {
-    my ($url,$func,$ignore_cache) = @_;
+    my ($url,$func,$ignore_cache,$nocache,$hashref) = @_;
     if (!$ignore_cache) {
 	my ($content,$cached)=
 	    &Apache::lonnet::is_cached_new('dns',$url);
 	if ($cached) {
-	    &$func($content);
+	    &$func($content,$hashref);
 	    return;
 	}
     }
@@ -11543,8 +11543,10 @@ sub get_dns {
         delete($alldns{$dns});
 	next if ($response->is_error());
 	my @content = split("\n",$response->content);
-	&Apache::lonnet::do_cache_new('dns',$url,\@content,30*24*60*60);
-	&$func(\@content);
+        unless ($nocache) {
+	    &Apache::lonnet::do_cache_new('dns',$url,\@content,30*24*60*60);
+        }
+	&$func(\@content,$hashref);
 	return;
     }
     close($config);
@@ -11552,9 +11554,62 @@ sub get_dns {
     &logthis("unable to contact DNS defaulting to on disk file dns_$which.tab\n");
     open($config,"<$perlvar{'lonTabDir'}/dns_$which.tab");
     my @content = <$config>;
-    &$func(\@content);
+    &$func(\@content,$hashref);
+    return;
+}
+
+# ------------------------------------------------------Get DNS checksums file
+sub parse_dns_checksums_tab {
+    my ($lines,$hashref) = @_;
+    my $machine_dom = &Apache::lonnet::host_domain($perlvar{'lonHostID'});
+    my $loncaparev = &get_server_loncaparev($machine_dom);
+    my ($release,$timestamp) = split(/\-/,$loncaparev);
+    my (%chksum,%revnum);
+    if (ref($lines) eq 'ARRAY') {
+        chomp(@{$lines});
+        my $versions = shift(@{$lines});
+        my %supported;
+        if ($versions =~ /^VERSIONS\:([\w\.\,]+)$/) {
+            my $releaseslist = $1;
+            if ($releaseslist =~ /,/) {
+                map { $supported{$_} = 1; } split(/,/,$releaseslist);
+            } elsif ($releaseslist) {
+                $supported{$releaseslist} = 1;
+            }
+        }
+        if ($supported{$release}) {
+            my $matchthis = 0;
+            foreach my $line (@{$lines}) {
+                if ($line =~ /^(\d[\w\.]+)$/) {
+                    if ($matchthis) {
+                        last;
+                    } elsif ($1 eq $release) {
+                        $matchthis = 1;
+                    }
+                } elsif ($matchthis) {
+                    my ($file,$version,$shasum) = split(/,/,$line);
+                    $chksum{$file} = $shasum;
+                    $revnum{$file} = $version;
+                }
+            }
+            if (ref($hashref) eq 'HASH') {
+                %{$hashref} = (
+                                sums     => \%chksum,
+                                versions => \%revnum,
+                              );
+            }
+        }
+    }
     return;
 }
+
+sub fetch_dns_checksums {
+    my %checksums;
+    &get_dns('/adm/dns/checksums',\&parse_dns_checksums_tab,1,1,
+             \%checksums);
+    return \%checksums;
+}
+
 # ------------------------------------------------------------ Read domain file
 {
     my $loaded;
@@ -12737,7 +12792,7 @@ returns the data handle
 
 =item *
 
-symbverify($symb,$thisfn,$ecstate) : verifies that $symb actually exists
+symbverify($symb,$thisfn,$encstate) : verifies that $symb actually exists
 and is a possible symb for the URL in $thisfn, and if is an encrypted
 resource that the user accessed using /enc/ returns a 1 on success, 0
 on failure, user must be in a course, as it assumes the existence of