--- projects/cms/source/host/ihost-perl/ihost.pl	2001/02/28 12:25:48	1.21
+++ projects/cms/source/host/ihost-perl/ihost.pl	2001/03/14 18:00:16	1.27
@@ -10,7 +10,7 @@
 #  - pjm2@ukc.ac.uk
 #
 # $Author: pjm2 $
-# $Id: ihost.pl,v 1.21 2001/02/28 12:25:48 pjm2 Exp $
+# $Id: ihost.pl,v 1.27 2001/03/14 18:00:16 pjm2 Exp $
 #------------------------------------------------------------
 
 $| = 1;
@@ -33,6 +33,7 @@ use vars qw (
              $filter_addr
              $file_list
              $fqdn
+             $pidfile
             );
 
 if (@ARGV != 2) {
@@ -44,6 +45,10 @@ $filter_manager_port = $ARGV[1];
 
 $seq_no = 1;
 
+# write our PID to a file
+$pidfile = "/var/tmp/ihost.pid";
+&write_pid();
+
 &tcp_configure();
 &send_udp_packet();
 
@@ -71,6 +76,8 @@ while (1) {
     `sleep $delay`;
 }
 
+# we'll probably never get here...
+`rm -f $pidfile`;
 exit(0);
 
 
@@ -151,9 +158,17 @@ sub tcp_configure() {
     
     print $sock "FILTER\n";
     $response = <$sock>;
+    unless (defined($response)) {
+        print "Failed: Could not get a filter address from the filter manager.\n";
+        exit(1);
+    }
     chop $response;
     $response =~ /(.*);(.*);(.*)/;
     ($filter_addr, $udp_port, $tcp_port) = ($1, $2, $3);
+    unless (defined($filter_addr) && defined($udp_port) && defined($tcp_port)) {
+        print "Failed: Filter address response from server did not make sense: $response\n";
+        exit(1);
+    }
     
     print "Got filter data ($filter_addr, $udp_port, $tcp_port)\n";
 
@@ -296,6 +311,7 @@ sub send_tcp_heartbeat() {
                                     ) or return;
     if (!defined $sock) {
         print "IHOST WARNING: Failed to deliver a heartbeat to the i-scream filter.\n";
+        &tcp_configure();
         return;
     }
 
@@ -304,56 +320,80 @@ sub send_tcp_heartbeat() {
 
     print $sock "HEARTBEAT\n";
     $response = <$sock>;
+    return if (!defined $response);
     chop $response;
     if (!$response eq "OK") {
         close($sock);
         print "Server gave wrong response to HEARTBEAT: $response\n";
+        &tcp_configure();
         return;
     }
     
     print $sock "CONFIG\n";
     $response = <$sock>;
+    return if (!defined $response);
     chop $response;
     if (!$response eq "OK") {
         close($sock);
         print "Server gave wrong response to CONFIG: $response\n";
+        &tcp_configure();
         return;
     }
 
     print $sock "$file_list\n";
     $response = <$sock>;
+    return if (!defined $response);
     chop $response;
     if (!$response eq "OK") {
         close($sock);
         print "Server gave wrong response to file list: $response\n";
+        &tcp_configure();
         return;
     }
     
     print $sock "$last_modified\n";
     $response = <$sock>;
+    return if (!defined $response);
     chop $response;
     if ($response eq "ERROR") {
         close($sock);
+        print "Server configuration changed.  Reconfiguring with filter manager.\n";
         &tcp_configure();
         return;
     }
     if (!$response eq "OK") {
         close($sock);
         print "Server gave wrong response to HEARTBEAT: $response\n";
+        &tcp_configure();
         return;
     }
     
     print $sock "ENDHEARTBEAT\n";
     $response = <$sock>;
+    return if (!defined $response);
     chop $response;
     if (!$response eq "OK") {
         close($sock);
         print "Server gave wrong response to ENDHEARTBEAT: $response\n";
+        &tcp_configure();
         return;
     }
     
     close($sock);
     print "^";
+    
+    return;
+}
+
+#-----------------------------------------------------------------------
+# write_pid
+# Writes the PID (process ID) of this instance to $pidfile.
+# This is then used by a seperate script to check (and restart) ihost.
+#-----------------------------------------------------------------------
+sub write_pid() {
+    open PID, ">$pidfile";
+    print PID $$;
+    close PID;
     
     return;
 }