--- loncom/lond	2004/07/27 10:50:37	1.213
+++ loncom/lond	2004/07/28 21:33:22	1.217
@@ -2,7 +2,7 @@
 # The LearningOnline Network
 # lond "LON Daemon" Server (port "LOND" 5663)
 #
-# $Id: lond,v 1.213 2004/07/27 10:50:37 foxr Exp $
+# $Id: lond,v 1.217 2004/07/28 21:33:22 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: 1.213 $'; #' stupid emacs
+my $VERSION='$Revision: 1.217 $'; #' stupid emacs
 my $remoteVERSION;
-my $currenthostid;
+my $currenthostid="default";
 my $currentdomainid;
 
 my $client;
@@ -1032,6 +1032,179 @@ 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.
+
+#++
+#
+# Handles pong requests.  Pong replies with our current host id, and
+#                         the results of a ping sent to us via our lonc.
+#
+# 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:
+#      $currenthostid - Global variable that carries the name of the host we are
+#                       connected to.
+#  Returns:
+#      1       - Ok to continue processing.
+#      0       - Program should exit.
+#  Side effects:
+#      Reply information is sent to the client.
+
+sub pong_handler {
+    my ($cmd, $tail, $replyfd) = @_;
+
+    my $reply=&reply("ping",$clientname);
+    &Reply( $replyfd, "$currenthostid:$reply\n", "$cmd:$tail"); 
+    return 1;
+}
+&register_handler("pong", \&pong_handler, 0, 1, 1);       # Pong unencoded, client or manager
+
+#++
+#      Called to establish an encrypted session key with the remote client.
+#      Note that with secure lond, in most cases this function is never
+#      invoked.  Instead, the secure session key is established either
+#      via a local file that's locked down tight and only lives for a short
+#      time, or via an ssl tunnel...and is generated from a bunch-o-random
+#      bits from /dev/urandom, rather than the predictable pattern used by
+#      by this sub.  This sub is only used in the old-style insecure
+#      key negotiation.
+# 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
+#                       known as.
+#      $clientname    - Global variable that carries the name of the hsot we're connected to.
+#  Returns:
+#      1       - Ok to continue processing.
+#      0       - Program should exit.
+#  Implicit Outputs:
+#      Reply information is sent to the client.
+#      $cipher is set with a reference to a new IDEA encryption object.
+#
+sub establish_key_handler {
+    my ($cmd, $tail, $replyfd) = @_;
+
+    my $buildkey=time.$$.int(rand 100000);
+    $buildkey=~tr/1-6/A-F/;
+    $buildkey=int(rand 100000).$buildkey.int(rand 100000);
+    my $key=$currenthostid.$clientname;
+    $key=~tr/a-z/A-Z/;
+    $key=~tr/G-P/0-9/;
+    $key=~tr/Q-Z/0-9/;
+    $key=$key.$buildkey.$key.$buildkey.$key.$buildkey;
+    $key=substr($key,0,32);
+    my $cipherkey=pack("H32",$key);
+    $cipher=new IDEA $cipherkey;
+    &Reply($replyfd, "$buildkey\n", "$cmd:$tail"); 
+   
+    return 1;
+
+}
+&register_handler("ekey", \&establish_key_handler, 0, 1,1);
+
+
+#     Handler for the load command.  Returns the current system load average
+#     to the requestor.
+#
+# 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
+#                       known as.
+#      $clientname    - Global variable that carries the name of the hsot we're connected to.
+#  Returns:
+#      1       - Ok to continue processing.
+#      0       - Program should exit.
+#  Side effects:
+#      Reply information is sent to the client.
+sub load_handler {
+    my ($cmd, $tail, $replyfd) = @_;
+
+   # Get the load average from /proc/loadavg and calculate it as a percentage of
+   # the allowed load limit as set by the perl global variable lonLoadLim
+
+    my $loadavg;
+    my $loadfile=IO::File->new('/proc/loadavg');
+   
+    $loadavg=<$loadfile>;
+    $loadavg =~ s/\s.*//g;                      # Extract the first field only.
+   
+    my $loadpercent=100*$loadavg/$perlvar{'lonLoadLim'};
+
+    &Reply( $replyfd, "$loadpercent\n", "$cmd:$tail");
+   
+    return 1;
+}
+register_handler("load", \&load_handler, 0, 1, 0);
+
+#
+#   Process the userload request.  This sub returns to the client the current
+#  user load average.  It can be invoked either by clients or managers.
+#
+# 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
+#                       known as.
+#      $clientname    - Global variable that carries the name of the hsot we're connected to.
+#  Returns:
+#      1       - Ok to continue processing.
+#      0       - Program should exit
+# Implicit inputs:
+#     whatever the userload() function requires.
+#  Implicit outputs:
+#     the reply is written to the client.
+#
+sub user_load_handler {
+    my ($cmd, $tail, $replyfd) = @_;
+
+    my $userloadpercent=&userload();
+    &Reply($replyfd, "$userloadpercent\n", "$cmd:$tail");
+    
+    return 1;
+}
+register_handler("userload", \&user_load_handler, 0, 1, 0);
+
+
 #---------------------------------------------------------------
 #
 #   Getting, decoding and dispatching requests:
@@ -1096,6 +1269,10 @@ sub process_request {
     chomp($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");
 
@@ -1139,65 +1316,10 @@ sub process_request {
 
     }    
 
-# ------------------------------------------------------------- Normal commands
-# ------------------------------------------------------------------------ ping
-    if ($userinput =~ /^ping/) {	# client only
-	if(isClient) {
-	    print $client "$currenthostid\n";
-	} else {
-	    Reply($client, "refused\n", $userinput);
-	}
-# ------------------------------------------------------------------------ pong
-    }elsif ($userinput =~ /^pong/) { # client only
-	if(isClient) {
-	    my $reply=&reply("ping",$clientname);
-	    print $client "$currenthostid:$reply\n"; 
-	} else {
-	    Reply($client, "refused\n", $userinput);
-	}
-# ------------------------------------------------------------------------ ekey
-    } elsif ($userinput =~ /^ekey/) { # ok for both clients & mgrs
-	my $buildkey=time.$$.int(rand 100000);
-	$buildkey=~tr/1-6/A-F/;
-	$buildkey=int(rand 100000).$buildkey.int(rand 100000);
-	my $key=$currenthostid.$clientname;
-	$key=~tr/a-z/A-Z/;
-	$key=~tr/G-P/0-9/;
-	$key=~tr/Q-Z/0-9/;
-	$key=$key.$buildkey.$key.$buildkey.$key.$buildkey;
-	$key=substr($key,0,32);
-	my $cipherkey=pack("H32",$key);
-	$cipher=new IDEA $cipherkey;
-	print $client "$buildkey\n"; 
-# ------------------------------------------------------------------------ load
-    } elsif ($userinput =~ /^load/) { # client only
-	if (isClient) {
-	    my $loadavg;
-	    {
-		my $loadfile=IO::File->new('/proc/loadavg');
-		$loadavg=<$loadfile>;
-	    }
-	    $loadavg =~ s/\s.*//g;
-	    my $loadpercent=100*$loadavg/$perlvar{'lonLoadLim'};
-	    print $client "$loadpercent\n";
-	} else {
-	    Reply($client, "refused\n", $userinput);
-	    
-	}
-# -------------------------------------------------------------------- userload
-    } elsif ($userinput =~ /^userload/) { # client only
-	if(isClient) {
-	    my $userloadpercent=&userload();
-	    print $client "$userloadpercent\n";
-	} else {
-	    Reply($client, "refused\n", $userinput);
-	    
-	}
-#
-#        Transactions requiring encryption:
-#
+#------------------- Commands not yet in spearate handlers. --------------
+
 # ----------------------------------------------------------------- currentauth
-    } elsif ($userinput =~ /^currentauth/) {
+    if ($userinput =~ /^currentauth/) {
 	if (($wasenc==1)  && isClient) { # Encoded & client only.
 	    my ($cmd,$udom,$uname)=split(/:/,$userinput);
 	    my $result = GetAuthType($udom, $uname);
@@ -3129,17 +3251,11 @@ 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);
 
 
 }