--- loncom/lond	2004/07/27 10:25:07	1.212
+++ loncom/lond	2004/07/27 11:10:47	1.214
@@ -2,7 +2,7 @@
 # The LearningOnline Network
 # lond "LON Daemon" Server (port "LOND" 5663)
 #
-# $Id: lond,v 1.212 2004/07/27 10:25:07 foxr Exp $
+# $Id: lond,v 1.214 2004/07/27 11:10:47 foxr Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -56,9 +56,9 @@ my $DEBUG = 0;		       # Non zero to ena
 my $status='';
 my $lastlog='';
 
-my $VERSION='$Revision: 1.212 $'; #' stupid emacs
+my $VERSION='$Revision: 1.214 $'; #' stupid emacs
 my $remoteVERSION;
-my $currenthostid;
+my $currenthostid="default";
 my $currentdomainid;
 
 my $client;
@@ -1032,6 +1032,37 @@ sub tie_user_hash {
     }
     
 }
+
+#--------------------- Request Handlers --------------------------------------------
+#
+#   By convention each request handler registers itself prior to the sub declaration:
+#
+
+#  Handles ping requests.
+#  Parameters:
+#      $cmd    - the actual keyword that invoked us.
+#      $tail   - the tail of the request that invoked us.
+#      $replyfd- File descriptor connected to the client
+#  Implicit Inputs:
+#      $currenthostid - Global variable that carries the name of the host we are
+#                       known as.
+#  Returns:
+#      1       - Ok to continue processing.
+#      0       - Program should exit.
+#  Side effects:
+#      Reply information is sent to the client.
+
+sub ping_handler {
+    my ($cmd, $tail, $client) = @_;
+    Debug("$cmd $tail $client .. $currenthostid:");
+   
+    Reply( $client,"$currenthostid\n","$cmd:$tail");
+   
+    return 1;
+}
+&register_handler("ping", \&ping_handler, 0, 1, 1);       # Ping unencoded, client or manager.
+
+
 #---------------------------------------------------------------
 #
 #   Getting, decoding and dispatching requests:
@@ -1079,16 +1110,72 @@ sub process_request {
     }
     Debug("process_request: $userinput\n");
     
-# ------------------------------------------------------------- Normal commands
-# ------------------------------------------------------------------------ ping
-    if ($userinput =~ /^ping/) {	# client only
-	if(isClient) {
-	    print $client "$currenthostid\n";
+    #  
+    #   The 'correct way' to add a command to lond is now to
+    #   write a sub to execute it and Add it to the command dispatch
+    #   hash via a call to register_handler..  The comments to that
+    #   sub should give you enough to go on to show how to do this
+    #   along with the examples that are building up as this code
+    #   is getting refactored.   Until all branches of the
+    #   if/elseif monster below have been factored out into
+    #   separate procesor subs, if the dispatch hash is missing
+    #   the command keyword, we will fall through to the remainder
+    #   of the if/else chain below in order to keep this thing in 
+    #   working order throughout the transmogrification.
+
+    my ($command, $tail) = split(/:/, $userinput, 2);
+    chomp($command);
+    chomp($tail);
+    $tail =~ s/(\r)//;		# This helps people debugging with e.g. telnet.
+    $command =~ s/(\r)//;	# And this too for parameterless commands.
+    if(!$tail) {
+	$tail ="";		# defined but blank.
+    }
+
+    &Debug("Command received: $command, encoded = $wasenc");
+
+    if(defined $Dispatcher{$command}) {
+
+	my $dispatch_info = $Dispatcher{$command};
+	my $handler       = $$dispatch_info[0];
+	my $need_encode   = $$dispatch_info[1];
+	my $client_types  = $$dispatch_info[2];
+	Debug("Matched dispatch hash: mustencode: $need_encode "
+	      ."ClientType $client_types");
+      
+	#  Validate the request:
+      
+	my $ok = 1;
+	my $requesterprivs = 0;
+	if(&isClient()) {
+	    $requesterprivs |= $CLIENT_OK;
+	}
+	if(&isManager()) {
+	    $requesterprivs |= $MANAGER_OK;
+	}
+	if($need_encode && (!$wasenc)) {
+	    Debug("Must encode but wasn't: $need_encode $wasenc");
+	    $ok = 0;
+	}
+	if(($client_types & $requesterprivs) == 0) {
+	    Debug("Client not privileged to do this operation");
+	    $ok = 0;
+	}
+
+	if($ok) {
+	    Debug("Dispatching to handler $command $tail");
+	    my $keep_going = &$handler($command, $tail, $client);
+	    return $keep_going;
 	} else {
-	    Reply($client, "refused\n", $userinput);
+	    Debug("Refusing to dispatch because client did not match requirements");
+	    Failure($client, "refused\n", $userinput);
+	    return 1;
 	}
-# ------------------------------------------------------------------------ pong
-    }elsif ($userinput =~ /^pong/) { # client only
+
+    }    
+
+# ------------------------------------------------------------- Normal commands
+    if ($userinput =~ /^pong/) { # client only
 	if(isClient) {
 	    my $reply=&reply("ping",$clientname);
 	    print $client "$currenthostid:$reply\n"; 
@@ -3069,17 +3156,11 @@ sub Debug {
 #     request - Original request from client.
 #
 sub Reply {
-    alarm(120);
-    my $fd      = shift;
-    my $reply   = shift;
-    my $request = shift;
-
     my ($fd, $reply, $request) = @_;
     print $fd $reply;
     Debug("Request was $request  Reply was $reply");
 
     $Transactions++;
-    alarm(0);
 
 
 }