--- projects/cms/source/host/ihost-perl/ihost.pl	2001/02/28 10:52:16	1.19
+++ projects/cms/source/host/ihost-perl/ihost.pl	2001/03/16 18:25:59	1.32
@@ -9,8 +9,8 @@
 # methods as you see fit.
 #  - pjm2@ukc.ac.uk
 #
-# $Author: tdb $
-# $Id: ihost.pl,v 1.19 2001/02/28 10:52:16 tdb Exp $
+# $Author: pjm2 $
+# $Id: ihost.pl,v 1.32 2001/03/16 18:25:59 pjm2 Exp $
 #------------------------------------------------------------
 
 $| = 1;
@@ -33,6 +33,8 @@ use vars qw (
              $filter_addr
              $file_list
              $fqdn
+             $pidfile
+             $retry_wait
             );
 
 if (@ARGV != 2) {
@@ -43,7 +45,12 @@ $filter_manager_addr = $ARGV[0];
 $filter_manager_port = $ARGV[1];
 
 $seq_no = 1;
+$retry_wait = 6;
 
+# write our PID to a file
+$pidfile = "/var/tmp/ihost.pid";
+&write_pid();
+
 &tcp_configure();
 &send_udp_packet();
 
@@ -71,10 +78,23 @@ while (1) {
     `sleep $delay`;
 }
 
+# we'll probably never get here...
+`rm -f $pidfile`;
 exit(0);
 
 
 #-----------------------------------------------------------------------
+# wait_then_retry
+# Waits for the period of time specified in $retry_wait, then attempts
+# to reconfigure with the server.
+#-----------------------------------------------------------------------
+sub wait_then_retry() {
+    print "Will retry configuration with filter manager in $retry_wait seconds.\n";
+    `sleep $retry_wait`;
+}
+
+
+#-----------------------------------------------------------------------
 # tcp_configure
 # Establishes a TCP connection to the specified i-scream filter manager.
 # The host then requests details from the server, such as the intervals
@@ -82,96 +102,150 @@ exit(0);
 #-----------------------------------------------------------------------
 sub tcp_configure() {
     
-    my($sock) = new IO::Socket::INET(
-                                     PeerAddr => $filter_manager_addr,
-                                     PeerPort => $filter_manager_port,
-                                     Proto => 'tcp'
-                                    );
-    if (!defined $sock) {
-        print "IHOST ERROR: Could not connect to $filter_manager_addr:$filter_manager_port.\n";
-        print "Please check that there is an i-scream server at this address.\n";
-        print "Program ended.\n";
-        exit(1);
-    }
+    while (1) {
+        my($sock) = new IO::Socket::INET(
+                                         PeerAddr => $filter_manager_addr,
+                                         PeerPort => $filter_manager_port,
+                                         Proto => 'tcp'
+                                        ) or die "Cannot connect!";
+        if (!defined $sock) {
+            print "IHOST ERROR: Could not connect to $filter_manager_addr:$filter_manager_port.\n";
+            print "Please check that there is an i-scream server at this address.\n";
+            wait_then_retry();
+            next;
+        }
 
-    # Now run through the configuration process...
-    my($response);
+        # Now run through the configuration process...
+        my($response);
     
-    print $sock "STARTCONFIG\n";
-    $response = <$sock>;
-    if (!chop $response eq "OK") {
-        print "The i-scream server rejected the STARTCONFIG command.  Terminated.";
-        exit(1);
-    }
+        print $sock "STARTCONFIG\n";
+        $response = <$sock>;
+        if ($response && !($response eq "OK\n")) {
+            print "The i-scream server rejected the STARTCONFIG command.\n";
+            close($sock);
+            wait_then_retry();
+            next;
+        }
 
-    print "Config started okay.\n";
+        print "Config started okay.\n";
     
-    print $sock "LASTMODIFIED\n";
-    $response = <$sock>;
-    chop $response;
-    $last_modified = $response;
+        print $sock "LASTMODIFIED\n";
+        $response = <$sock>;
+        if (!$response) {
+            print "The i-scream server did not return anything for the LASTMODIFIED command.\n";
+            close($sock);
+            wait_then_retry();
+            next;
+        }
+        chop $response;
+        $last_modified = $response;
     
-    print "Config last modified: ". (scalar localtime $last_modified/1000) . "\n";
+        print "Config last modified: ". (scalar localtime $last_modified/1000) . "\n";
 
-    print $sock "FILELIST\n";
-    $response = <$sock>;
-    chop $response;
-    $file_list = $response;
+        print $sock "FILELIST\n";
+        $response = <$sock>;
+        if (!$response) {
+            print "The i-scream server did not provide a configuration file list.\n";
+            close($sock);
+            wait_then_retry();
+            next;
+        }
+        chop $response;
+        $file_list = $response;
 
-    print "File list obtained: $file_list\n";
+        print "File list obtained: $file_list\n";
 
-    print $sock "FQDN\n";
-    $response = <$sock>;
-    chop $response;
-    $fqdn = $response;
+        print $sock "FQDN\n";
+        $response = <$sock>;
+        if (!$response) {
+            print "The i-scream server did not tell us our FQDN.\n";
+            close($sock);
+            wait_then_retry();
+            next;
+        }
+        chop $response;
+        $fqdn = $response;
 
-    print "FQDN returned: $fqdn\n";
+        print "FQDN returned: $fqdn\n";
 
-    print $sock "UDPUpdateTime\n";
-    $response = <$sock>;
-    chop $response;
-    $udp_update_time = $response;
+        print $sock "UDPUpdateTime\n";
+        $response = <$sock>;
+        if (!$response) {
+            print "The i-scream server did not give us a UDPUpdateTime.\n";
+            close($sock);
+            wait_then_retry();
+            next;
+        }
+        chop $response;
+        $udp_update_time = $response;
 
-    print $sock "TCPUpdateTime\n";
-    $response = <$sock>;
-    chop $response;
-    $tcp_update_time = $response;
+        print $sock "TCPUpdateTime\n";
+        $response = <$sock>;
+        if (!$response) {
+            print "The i-scream server did not give us a TCPUpdateTime.\n";
+            close($sock);
+            wait_then_retry();
+            next;
+        }
+        chop $response;
+        $tcp_update_time = $response;
     
-    print "UDP packet period: $udp_update_time seconds.\nTCP heartbeat period: $tcp_update_time seconds.\n";
+        print "UDP packet period: $udp_update_time seconds.\nTCP heartbeat period: $tcp_update_time seconds.\n";
 
-    print $sock "ENDCONFIG\n";
-    $response = <$sock>;
-    chomp $response;
-    if (!$response eq "OK") {
-        print "ENDCONFIG command to server failed.  Terminated.\n";
-        exit(1);
-    }
+        print $sock "ENDCONFIG\n";
+        $response = <$sock>;
+        if ($response && !($response eq "OK\n")) {
+            print "ENDCONFIG command to server failed.  Terminated.\n";
+            close($sock);
+            wait_then_retry();
+            next;
+        }
 
-    print "Config ended.\n";
+        print "Config ended.\n";
     
-    print $sock "FILTER\n";
-    $response = <$sock>;
-    chop $response;
-    $response =~ /(.*);(.*);(.*)/;
-    ($filter_addr, $udp_port, $tcp_port) = ($1, $2, $3);
+        print $sock "FILTER\n";
+        $response = <$sock>;
+        if (!$response) {
+            print "Failed: Could not get a filter address from the filter manager.\n";
+            close($sock);
+            wait_then_retry();
+            next;
+        }
+        chop $response;
+        $response =~ /^(.*);(.*);(.*)/;
+        if ($response eq "ERROR") {
+            print "There are no active configured filters for your host.\n";
+            close($sock);
+            wait_then_retry();
+            next;
+        }
+        ($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: $response\n";
+            close($sock);
+            wait_then_retry();
+            next;
+        }
     
-    print "Got filter data ($filter_addr, $udp_port, $tcp_port)\n";
+        print "Got filter data ($filter_addr, $udp_port, $tcp_port)\n";
 
-    print $sock "END\n";
-    $response = <$sock>;
-    chop $response;
-    if ($response eq "OK") {
-        print "Host successfully configured via TCP.\n"
-    }
-    else {
-        print "The server failed the host configuration on the END command.";
-        exit(1);
-    }
+        print $sock "END\n";
+        $response = <$sock>;
+        if ($response && ($response eq "OK\n")) {
+            print "Host successfully configured via TCP.\n"
+        }
+        else {
+            print "The server failed the host configuration on the END command.\n";
+            close($sock);
+            wait_then_retry();
+            next;
+        }
     
-    close($sock);
+        close($sock);
 
-    print "Configuration finished sucessfully!\n";
-    
+        print "Configuration finished sucessfully!\n";
+        last;
+    }
     return;
 }
 
@@ -265,13 +339,11 @@ EOF
     # Make the packet smaller by stripping out newlines and leading spaces.
     $xml =~ s/\n\s*//g;
 
-print $xml;
-    
     my($sock) = new IO::Socket::INET (
                                       PeerPort => $udp_port,
                                       PeerAddr => $filter_addr,
                                       Proto => 'udp'
-                                     ) or die "Socket: $!\n";
+                                     ) or die "Could not send UDP: $!\n";
 
     print $sock $xml or die "Could not send UDP packet: $!\n";
     close($sock);
@@ -295,9 +367,10 @@ sub send_tcp_heartbeat() {
                                      PeerAddr => $filter_addr,
                                      PeerPort => $tcp_port,
                                      Proto => 'tcp'
-                                    );
+                                    ) or return;
     if (!defined $sock) {
         print "IHOST WARNING: Failed to deliver a heartbeat to the i-scream filter.\n";
+        &tcp_configure();
         return;
     }
 
@@ -306,56 +379,70 @@ sub send_tcp_heartbeat() {
 
     print $sock "HEARTBEAT\n";
     $response = <$sock>;
-    chop $response;
-    if (!$response eq "OK") {
+    if (!$response eq "OK\n") {
         close($sock);
         print "Server gave wrong response to HEARTBEAT: $response\n";
+        &tcp_configure();
         return;
     }
     
     print $sock "CONFIG\n";
     $response = <$sock>;
-    chop $response;
-    if (!$response eq "OK") {
+    if (!$response eq "OK\n") {
         close($sock);
         print "Server gave wrong response to CONFIG: $response\n";
+        &tcp_configure();
         return;
     }
 
     print $sock "$file_list\n";
     $response = <$sock>;
-    chop $response;
-    if (!$response eq "OK") {
+    if (!$response eq "OK\n") {
         close($sock);
         print "Server gave wrong response to file list: $response\n";
+        &tcp_configure();
         return;
     }
     
     print $sock "$last_modified\n";
     $response = <$sock>;
-    chop $response;
-    if ($response eq "ERROR") {
+    if ($response eq "ERROR\n") {
         close($sock);
+        print "Server configuration changed.  Reconfiguring with filter manager.\n";
         &tcp_configure();
         return;
     }
-    if (!$response eq "OK") {
+    if (!$response eq "OK\n") {
         close($sock);
         print "Server gave wrong response to HEARTBEAT: $response\n";
+        &tcp_configure();
         return;
     }
     
     print $sock "ENDHEARTBEAT\n";
     $response = <$sock>;
-    chop $response;
-    if (!$response eq "OK") {
+    if (!$response eq "OK\n") {
         close($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;
 }