--- loncom/lond	2000/12/05 03:24:48	1.22
+++ loncom/lond	2003/03/14 21:25:44	1.103.2.1
@@ -1,6 +1,31 @@
 #!/usr/bin/perl
 # The LearningOnline Network
 # lond "LON Daemon" Server (port "LOND" 5663)
+#
+# $Id: lond,v 1.103.2.1 2003/03/14 21:25:44 albertel Exp $
+#
+# Copyright Michigan State University Board of Trustees
+#
+# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
+#
+# LON-CAPA is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# LON-CAPA is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with LON-CAPA; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# /home/httpd/html/adm/gpl.txt
+#
+# http://www.lon-capa.org/
+#
 # 5/26/99,6/4,6/10,6/11,6/14,6/15,6/26,6/28,6/30,
 # 7/8,7/9,7/10,7/12,7/17,7/19,9/21,
 # 10/7,10/8,10/9,10/11,10/13,10/15,11/4,11/16,
@@ -8,13 +33,38 @@
 # 03/07,05/31 Gerd Kortemeyer
 # 06/26 Scott Harrison
 # 06/29,06/30,07/14,07/15,07/17,07/20,07/25,09/18 Gerd Kortemeyer
-#
+# 12/05 Scott Harrison
+# 12/05,12/13,12/29 Gerd Kortemeyer
+# YEAR=2001
+# Jan 01 Scott Harrison
+# 02/12 Gerd Kortemeyer
+# 03/15 Scott Harrison
+# 03/24 Gerd Kortemeyer
+# 04/02 Scott Harrison
+# 05/11,05/28,08/30 Gerd Kortemeyer
+# 9/30,10/22,11/13,11/15,11/16 Scott Harrison
+# 11/26,11/27 Gerd Kortemeyer
+# 12/20 Scott Harrison
+# 12/22 Gerd Kortemeyer
+# YEAR=2002
+# 01/20/02,02/05 Gerd Kortemeyer
+# 02/05 Guy Albertelli
+# 02/07 Scott Harrison
+# 02/12 Gerd Kortemeyer
+# 02/19 Matthew Hall
+# 02/25 Gerd Kortemeyer
+# 05/11 Scott Harrison
+###
+
 # based on "Perl Cookbook" ISBN 1-56592-243-3
 # preforker - server who forks first
 # runs as a daemon
 # HUPs
 # uses IDEA encryption
 
+use lib '/home/httpd/lib/perl/';
+use LONCAPA::Configuration;
+
 use IO::Socket;
 use IO::File;
 use Apache::File;
@@ -24,25 +74,115 @@ use Crypt::IDEA;
 use LWP::UserAgent();
 use GDBM_File;
 use Authen::Krb4;
+use Authen::Krb5;
+use lib '/home/httpd/lib/perl/';
+use localauth;
 
-# -------------------------------- Set signal handlers to record abnormal exits
+my $DEBUG = 0;		       # Non zero to enable debug log entries.
 
-$SIG{'QUIT'}=\&catchexception;
-$SIG{__DIE__}=\&catchexception;
+my $status='';
+my $lastlog='';
 
-# ------------------------------------ Read httpd access.conf and get variables
+#
+#  The array below are password error strings."
+#
+my $lastpwderror    = 13;		# Largest error number from lcpasswd.
+my @passwderrors = ("ok",
+		   "lcpasswd must be run as user 'www'",
+		   "lcpasswd got incorrect number of arguments",
+		   "lcpasswd did not get the right nubmer of input text lines",
+		   "lcpasswd too many simultaneous pwd changes in progress",
+		   "lcpasswd User does not exist.",
+		   "lcpasswd Incorrect current passwd",
+		   "lcpasswd Unable to su to root.",
+		   "lcpasswd Cannot set new passwd.",
+		   "lcpasswd Username has invalid characters",
+		   "lcpasswd Invalid characters in password",
+		    "11", "12",
+		    "lcpasswd Password mismatch");
+
+
+#  The array below are lcuseradd error strings.:
+
+my $lastadderror = 13;
+my @adderrors    = ("ok",
+		    "User ID mismatch, lcuseradd must run as user www",
+		    "lcuseradd Incorrect number of command line parameters must be 3",
+		    "lcuseradd Incorrect number of stdinput lines, must be 3",
+		    "lcuseradd Too many other simultaneous pwd changes in progress",
+		    "lcuseradd User does not exist",
+		    "lcuseradd Unabel to mak ewww member of users's group",
+		    "lcuseradd Unable to su to root",
+		    "lcuseradd Unable to set password",
+		    "lcuseradd Usrname has invbalid charcters",
+		    "lcuseradd Password has an invalid character",
+		    "lcuseradd User already exists",
+		    "lcuseradd Could not add user.",
+		    "lcuseradd Password mismatch");
 
-open (CONFIG,"/etc/httpd/conf/access.conf")
-    || catchdie "Can't read access.conf";
 
-while ($configline=<CONFIG>) {
-    if ($configline =~ /PerlSetVar/) {
-	my ($dummy,$varname,$varvalue)=split(/\s+/,$configline);
-        chomp($varvalue);
-        $perlvar{$varname}=$varvalue;
+#
+#  Convert an error return code from lcpasswd to a string value.
+#
+sub lcpasswdstrerror {
+    my $ErrorCode = shift;
+    if(($ErrorCode < 0) || ($ErrorCode > $lastpwderror)) {
+	return "lcpasswd Unrecognized error return value ".$ErrorCode;
+    } else {
+	return $passwderrors[$ErrorCode];
     }
 }
-close(CONFIG);
+
+#
+# Convert an error return code from lcuseradd to a string value:
+#
+sub lcuseraddstrerror {
+    my $ErrorCode = shift;
+    if(($ErrorCode < 0) || ($ErrorCode > $lastadderror)) {
+	return "lcuseradd - Unrecognized error code: ".$ErrorCode;
+    } else {
+	return $adderrors[$ErrorCode];
+    }
+}
+
+# grabs exception and records it to log before exiting
+sub catchexception {
+    my ($error)=@_;
+    $SIG{'QUIT'}='DEFAULT';
+    $SIG{__DIE__}='DEFAULT';
+    &logthis("<font color=red>CRITICAL: "
+     ."ABNORMAL EXIT. Child $$ for server $wasserver died through "
+     ."a crash with this error msg->[$error]</font>");
+    &logthis('Famous last words: '.$status.' - '.$lastlog);
+    if ($client) { print $client "error: $error\n"; }
+    $server->close();
+    die($error);
+}
+
+sub timeout {
+    &logthis("<font color=ref>CRITICAL: TIME OUT ".$$."</font>");
+    &catchexception('Timeout');
+}
+# -------------------------------- Set signal handlers to record abnormal exits
+
+$SIG{'QUIT'}=\&catchexception;
+$SIG{__DIE__}=\&catchexception;
+
+# ---------------------------------- Read loncapa_apache.conf and loncapa.conf
+&status("Read loncapa.conf and loncapa_apache.conf");
+my $perlvarref=LONCAPA::Configuration::read_conf('loncapa.conf');
+my %perlvar=%{$perlvarref};
+undef $perlvarref;
+
+# ----------------------------- Make sure this process is running from user=www
+my $wwwid=getpwnam('www');
+if ($wwwid!=$<) {
+   $emailto="$perlvar{'lonAdmEMail'},$perlvar{'lonSysEMail'}";
+   $subj="LON: $perlvar{'lonHostID'} User ID mismatch";
+   system("echo 'User ID mismatch.  lond must be run as user www.' |\
+ mailto $emailto -s '$subj' > /dev/null");
+   exit 1;
+}
 
 # --------------------------------------------- Check if other instance running
 
@@ -52,19 +192,18 @@ if (-e $pidfile) {
    my $lfh=IO::File->new("$pidfile");
    my $pide=<$lfh>;
    chomp($pide);
-   if (kill 0 => $pide) { catchdie "already running"; }
+   if (kill 0 => $pide) { die "already running"; }
 }
 
 $PREFORK=4; # number of children to maintain, at least four spare
 
 # ------------------------------------------------------------- Read hosts file
 
-open (CONFIG,"$perlvar{'lonTabDir'}/hosts.tab")
-    || catchdie "Can't read host file";
+open (CONFIG,"$perlvar{'lonTabDir'}/hosts.tab") || die "Can't read host file";
 
 while ($configline=<CONFIG>) {
     my ($id,$domain,$role,$name,$ip)=split(/:/,$configline);
-    chomp($ip);
+    chomp($ip); $ip=~s/\D+$//;
     $hostid{$ip}=$id;
     if ($id eq $perlvar{'lonHostID'}) { $thisserver=$name; }
     $PREFORK++;
@@ -77,13 +216,13 @@ $server = IO::Socket::INET->new(LocalPor
                                 Proto     => 'tcp',
                                 Reuse     => 1,
                                 Listen    => 10 )
-  or catchdie "making socket: $@\n";
+  or die "making socket: $@\n";
 
 # --------------------------------------------------------- Do global variables
 
 # global variables
 
-$MAX_CLIENTS_PER_CHILD  = 5;        # number of clients each child should 
+$MAX_CLIENTS_PER_CHILD  = 50;        # number of clients each child should 
                                     # process
 %children               = ();       # keys are current child process IDs
 $children               = 0;        # current number of children
@@ -91,14 +230,19 @@ $children               = 0;        # cu
 sub REAPER {                        # takes care of dead children
     $SIG{CHLD} = \&REAPER;
     my $pid = wait;
-    $children --;
-    &logthis("Child $pid died");
-    delete $children{$pid};
+    if (defined($children{$pid})) {
+	&logthis("Child $pid died");
+	$children --;
+	delete $children{$pid};
+    } else {
+	&logthis("Unknown Child $pid died");
+    }
 }
 
 sub HUNTSMAN {                      # signal handler for SIGINT
     local($SIG{CHLD}) = 'IGNORE';   # we're going to kill our children
     kill 'INT' => keys %children;
+    &logthis("Free socket: ".shutdown($server,2)); # free up socket
     my $execdir=$perlvar{'lonDaemons'};
     unlink("$execdir/logs/lond.pid");
     &logthis("<font color=red>CRITICAL: Shutting down</font>");
@@ -108,12 +252,47 @@ sub HUNTSMAN {                      # si
 sub HUPSMAN {                      # signal handler for SIGHUP
     local($SIG{CHLD}) = 'IGNORE';  # we're going to kill our children
     kill 'INT' => keys %children;
-    close($server);                # free up socket
+    &logthis("Free socket: ".shutdown($server,2)); # free up socket
     &logthis("<font color=red>CRITICAL: Restarting</font>");
+    unlink("$execdir/logs/lond.pid");
     my $execdir=$perlvar{'lonDaemons'};
     exec("$execdir/lond");         # here we go again
 }
 
+sub checkchildren {
+    &initnewstatus();
+    &logstatus();
+    &logthis('Going to check on the children');
+    $docdir=$perlvar{'lonDocRoot'};
+    foreach (sort keys %children) {
+	sleep 1;
+        unless (kill 'USR1' => $_) {
+	    &logthis ('Child '.$_.' is dead');
+            &logstatus($$.' is dead');
+        } 
+    }
+    sleep 5;
+    $SIG{ALRM} = sub { die "timeout" };
+    $SIG{__DIE__} = 'DEFAULT';
+    foreach (sort keys %children) {
+        unless (-e "$docdir/lon-status/londchld/$_.txt") {
+          eval {
+            alarm(300);
+	    &logthis('Child '.$_.' did not respond');
+	    kill 9 => $_;
+	    $emailto="$perlvar{'lonAdmEMail'},$perlvar{'lonSysEMail'}";
+	    $subj="LON: $perlvar{'lonHostID'} killed lond process $_";
+	    my $result=`echo 'Killed lond process $_.' | mailto $emailto -s '$subj' > /dev/null`;
+	    $execdir=$perlvar{'lonDaemons'};
+	    $result=`/bin/cp $execdir/logs/lond.log $execdir/logs/lond.log.$_`;
+	    alarm(0);
+	  }
+        }
+    }
+    $SIG{ALRM} = 'DEFAULT';
+    $SIG{__DIE__} = \&cathcexception;
+}
+
 # --------------------------------------------------------------------- Logging
 
 sub logthis {
@@ -122,9 +301,55 @@ sub logthis {
     my $fh=IO::File->new(">>$execdir/logs/lond.log");
     my $now=time;
     my $local=localtime($now);
+    $lastlog=$local.': '.$message;
     print $fh "$local ($$): $message\n";
 }
 
+# ------------------------- Conditional log if $DEBUG true.
+sub Debug {
+    my $message = shift;
+    if($DEBUG) {
+	&logthis($message);
+    }
+}
+# ------------------------------------------------------------------ Log status
+
+sub logstatus {
+    my $docdir=$perlvar{'lonDocRoot'};
+    {
+    my $fh=IO::File->new(">>$docdir/lon-status/londstatus.txt");
+    print $fh $$."\t".$status."\t".$lastlog."\n";
+    $fh->close();
+    }
+    {
+	my $fh=IO::File->new(">$docdir/lon-status/londchld/$$.txt");
+        print $fh $status."\n".$lastlog."\n".time;
+        $fh->close();
+    }
+}
+
+sub initnewstatus {
+    my $docdir=$perlvar{'lonDocRoot'};
+    my $fh=IO::File->new(">$docdir/lon-status/londstatus.txt");
+    my $now=time;
+    my $local=localtime($now);
+    print $fh "LOND status $local - parent $$\n\n";
+    opendir(DIR,"$docdir/lon-status/londchld");
+    while ($filename=readdir(DIR)) {
+        unlink("$docdir/lon-status/londchld/$filename");
+    }
+    closedir(DIR);
+}
+
+# -------------------------------------------------------------- Status setting
+
+sub status {
+    my $what=shift;
+    my $now=time;
+    my $local=localtime($now);
+    $status=$local.': '.$what;
+    $0='lond: '.$what.' '.$local;
+}
 
 # -------------------------------------------------------- Escape Special Chars
 
@@ -154,10 +379,10 @@ sub reconlonc {
         if (kill 0 => $loncpid) {
 	    &logthis("lonc at pid $loncpid responding, sending USR1");
             kill USR1 => $loncpid;
-            sleep 1;
+            sleep 5;
             if (-e "$peerfile") { return; }
             &logthis("$peerfile still not there, give it another try");
-            sleep 5;
+            sleep 10;
             if (-e "$peerfile") { return; }
             &logthis(
  "<font color=blue>WARNING: $peerfile still not there, giving up</font>");
@@ -195,6 +420,7 @@ sub reply {
     if ($answer eq 'con_lost') {
 	$answer=subreply("ping",$server);
         if ($answer ne $server) {
+	    &logthis("sub reply: answer != server");
            &reconlonc("$perlvar{'lonSockDir'}/$server");
         }
         $answer=subreply($cmd,$server);
@@ -260,9 +486,9 @@ sub ishome {
 
 $fpid=fork;
 exit if $fpid;
-catchdie "Couldn't fork: $!" unless defined ($fpid);
+die "Couldn't fork: $!" unless defined ($fpid);
 
-POSIX::setsid() or catchdie "Can't start new session: $!";
+POSIX::setsid() or die "Can't start new session: $!";
 
 # ------------------------------------------------------- Write our PID on disk
 
@@ -271,6 +497,7 @@ open (PIDSAVE,">$execdir/logs/lond.pid")
 print PIDSAVE "$$\n";
 close(PIDSAVE);
 &logthis("<font color=red>CRITICAL: ---------- Starting ----------</font>");
+&status('Starting');
 
 # ------------------------------------------------------- Now we are on our own
     
@@ -281,13 +508,19 @@ for (1 .. $PREFORK) {
 
 # ----------------------------------------------------- Install signal handlers
 
+&status('Forked children');
+
 $SIG{CHLD} = \&REAPER;
 $SIG{INT}  = $SIG{TERM} = \&HUNTSMAN;
 $SIG{HUP}  = \&HUPSMAN;
+$SIG{USR1} = \&checkchildren;
 
 # And maintain the population.
 while (1) {
+    &status('Sleeping');
     sleep;                          # wait for a signal (i.e., child's death)
+    &logthis('Woke up');
+    &status('Woke up');
     for ($i = $children; $i < $PREFORK; $i++) {
         make_new_child();           # top up the child pool
     }
@@ -301,48 +534,64 @@ sub make_new_child {
     # block signal for fork
     $sigset = POSIX::SigSet->new(SIGINT);
     sigprocmask(SIG_BLOCK, $sigset)
-        or catchdie "Can't block SIGINT for fork: $!\n";
+        or die "Can't block SIGINT for fork: $!\n";
     
-    catchdie "fork: $!" unless defined ($pid = fork);
+    die "fork: $!" unless defined ($pid = fork);
     
     if ($pid) {
         # Parent records the child's birth and returns.
         sigprocmask(SIG_UNBLOCK, $sigset)
-            or catchdie "Can't unblock SIGINT for fork: $!\n";
+            or die "Can't unblock SIGINT for fork: $!\n";
         $children{$pid} = 1;
         $children++;
+        &status('Started child '.$pid);
         return;
     } else {
         # Child can *not* return from this subroutine.
         $SIG{INT} = 'DEFAULT';      # make SIGINT kill us as it did before
-    
+        $SIG{USR1}= \&logstatus;
+        $SIG{ALRM}= \&timeout;
+        $lastlog='Forked ';
+        $status='Forked';
+
         # unblock signals
         sigprocmask(SIG_UNBLOCK, $sigset)
-            or catchdie "Can't unblock SIGINT for fork: $!\n";
+            or die "Can't unblock SIGINT for fork: $!\n";
 
         $tmpsnum=0;
-    
+#---------------------------------------------------- kerberos 5 initialization
+        &Authen::Krb5::init_context();
+        &Authen::Krb5::init_ets();
+
         # handle connections until we've reached $MAX_CLIENTS_PER_CHILD
         for ($i=0; $i < $MAX_CLIENTS_PER_CHILD; $i++) {
+            &status('Idle, waiting for connection');
             $client = $server->accept()     or last;
-
+            &status('Accepted connection');
 # =============================================================================
             # do something with the connection
 # -----------------------------------------------------------------------------
+	    $client->sockopt(SO_KEEPALIVE, 1);# Enable monitoring of
+	                                      # connection liveness.
             # see if we know client and check for spoof IP by challenge
             my $caller=getpeername($client);
             my ($port,$iaddr)=unpack_sockaddr_in($caller);
             my $clientip=inet_ntoa($iaddr);
             my $clientrec=($hostid{$clientip} ne undef);
             &logthis(
-"<font color=yellow>INFO: Connect from $clientip ($hostid{$clientip})</font>");
+"<font color=yellow>INFO: Connection $i, $clientip ($hostid{$clientip})</font>"
+            );
+            &status("Connecting $clientip ($hostid{$clientip})"); 
             my $clientok;
             if ($clientrec) {
+	      &status("Waiting for init from $clientip ($hostid{$clientip})");
 	      my $remotereq=<$client>;
               $remotereq=~s/\W//g;
               if ($remotereq eq 'init') {
 		  my $challenge="$$".time;
                   print $client "$challenge\n";
+                  &status(
+           "Waiting for challenge reply from $clientip ($hostid{$clientip})"); 
                   $remotereq=<$client>;
                   $remotereq=~s/\W//g;
                   if ($challenge eq $remotereq) {
@@ -351,28 +600,33 @@ sub make_new_child {
                   } else {
 		      &logthis(
  "<font color=blue>WARNING: $clientip did not reply challenge</font>");
-                      print $client "bye\n";
+                      &status('No challenge reply '.$clientip);
                   }
               } else {
 		  &logthis(
                     "<font color=blue>WARNING: "
                    ."$clientip failed to initialize: >$remotereq< </font>");
-		  print $client "bye\n";
+                  &status('No init '.$clientip);
               }
 	    } else {
               &logthis(
  "<font color=blue>WARNING: Unknown client $clientip</font>");
-              print $client "bye\n";
+              &status('Hung up on '.$clientip);
             }
             if ($clientok) {
 # ---------------- New known client connecting, could mean machine online again
+
 	      &reconlonc("$perlvar{'lonSockDir'}/$hostid{$clientip}");
               &logthis(
        "<font color=green>Established connection: $hostid{$clientip}</font>");
+              &status('Will listen to '.$hostid{$clientip});
 # ------------------------------------------------------------ Process requests
               while (my $userinput=<$client>) {
                 chomp($userinput);
+		Debug("Request = $userinput\n");
+                &status('Processing '.$hostid{$clientip}.': '.$userinput);
                 my $wasenc=0;
+                alarm(120);
 # ------------------------------------------------------------ See if encrypted
 		if ($userinput =~ /^enc/) {
 		  if ($cipher) {
@@ -386,8 +640,9 @@ sub make_new_child {
 		    }
 		    $userinput=substr($userinput,0,$cmdlength);
                     $wasenc=1;
-		  }
 		}
+	      }
+	  
 # ------------------------------------------------------------- Normal commands
 # ------------------------------------------------------------------------ ping
 		   if ($userinput =~ /^ping/) {
@@ -420,6 +675,20 @@ sub make_new_child {
                        $loadavg =~ s/\s.*//g;
                        my $loadpercent=100*$loadavg/$perlvar{'lonLoadLim'};
 		       print $client "$loadpercent\n";
+# ----------------------------------------------------------------- currentauth
+		   } elsif ($userinput =~ /^currentauth/) {
+		     if ($wasenc==1) {
+                       my ($cmd,$udom,$uname)=split(/:/,$userinput);
+		       my $result = GetAuthType($udom, $uname);
+		       if($result eq "nouser") {
+			   print $client "unknown_user\n";
+		       }
+		       else {
+			   print $client "$result\n"
+		       }
+		     } else {
+		       print $client "refused\n";
+		     }
 # ------------------------------------------------------------------------ auth
                    } elsif ($userinput =~ /^auth/) {
 		     if ($wasenc==1) {
@@ -435,18 +704,59 @@ sub make_new_child {
                           my ($howpwd,$contentpwd)=split(/:/,$realpasswd);
                           my $pwdcorrect=0;
                           if ($howpwd eq 'internal') {
+			      &Debug("Internal auth");
 			      $pwdcorrect=
 				  (crypt($upass,$contentpwd) eq $contentpwd);
                           } elsif ($howpwd eq 'unix') {
-                              $contentpwd=(getpwnam($uname))[1];
-                              $pwdcorrect=
-                                  (crypt($upass,$contentpwd) eq $contentpwd);
+			      &Debug("Unix auth");
+                              if((getpwnam($uname))[1] eq "") { #no such user!
+				  $pwdcorrect = 0;
+			      } else {
+				  $contentpwd=(getpwnam($uname))[1];
+				  my $pwauth_path="/usr/local/sbin/pwauth";
+				  unless ($contentpwd eq 'x') {
+				      $pwdcorrect=
+					  (crypt($upass,$contentpwd) eq 
+					   $contentpwd);
+				  }
+		  
+			      elsif (-e $pwauth_path) {
+				  open PWAUTH, "|$pwauth_path" or
+				      die "Cannot invoke authentication";
+				  print PWAUTH "$uname\n$upass\n";
+				  close PWAUTH;
+				  $pwdcorrect=!$?;
+			      }
+			      }
                           } elsif ($howpwd eq 'krb4') {
+                             $null=pack("C",0);
+			     unless ($upass=~/$null/) {
                               $pwdcorrect=(
                                  Authen::Krb4::get_pw_in_tkt($uname,"",
                                         $contentpwd,'krbtgt',$contentpwd,1,
 							     $upass) == 0);
-                          }
+			     } else { $pwdcorrect=0; }
+                          } elsif ($howpwd eq 'krb5') {
+			      $null=pack("C",0);
+			      unless ($upass=~/$null/) {
+				  my $krbclient=&Authen::Krb5::parse_name($uname.'@'.$contentpwd);
+				  my $krbservice="krbtgt/".$contentpwd."\@".$contentpwd;
+				  my $krbserver=&Authen::Krb5::parse_name($krbservice);
+				  my $credentials=&Authen::Krb5::cc_default();
+				  $credentials->initialize($krbclient);
+				  my $krbreturn = 
+				    &Authen::Krb5::get_in_tkt_with_password(
+				     $krbclient,$krbserver,$upass,$credentials);
+#				  unless ($krbreturn) {
+#				      &logthis("Krb5 Error: ".
+#					       &Authen::Krb5::error());
+#				  }
+				  $pwdcorrect = ($krbreturn == 1);
+			   } else { $pwdcorrect=0; }
+                          } elsif ($howpwd eq 'localauth') {
+			    $pwdcorrect=&localauth::localauth($uname,$upass,
+							      $contentpwd);
+			  }
                           if ($pwdcorrect) {
                              print $client "authorized\n";
                           } else {
@@ -464,7 +774,10 @@ sub make_new_child {
                        my 
                        ($cmd,$udom,$uname,$upass,$npass)=split(/:/,$userinput);
                        chomp($npass);
-                       my $proname=propath($udom,$uname);
+                       $upass=&unescape($upass);
+                       $npass=&unescape($npass);
+		       &Debug("Trying to change password for $uname");
+		       my $proname=propath($udom,$uname);
                        my $passfilename="$proname/passwd";
                        if (-e $passfilename) {
 			   my $realpasswd;
@@ -473,17 +786,54 @@ sub make_new_child {
                           chomp($realpasswd);
                           my ($howpwd,$contentpwd)=split(/:/,$realpasswd);
                           if ($howpwd eq 'internal') {
+			   &Debug("internal auth");
 			   if (crypt($upass,$contentpwd) eq $contentpwd) {
 			     my $salt=time;
                              $salt=substr($salt,6,2);
 			     my $ncpass=crypt($npass,$salt);
                              { my $pf = IO::File->new(">$passfilename");
- 	  		       print $pf "internal:$ncpass\n";; }             
+ 	  		       print $pf "internal:$ncpass\n"; }             
+			     &logthis("Result of password change for $uname: pwchange_success");
                              print $client "ok\n";
                            } else {
                              print $client "non_authorized\n";
                            }
-                          } else {
+                          } elsif ($howpwd eq 'unix') {
+			      # Unix means we have to access /etc/password
+			      # one way or another.
+			      # First: Make sure the current password is
+			      #        correct
+			      &Debug("auth is unix");
+			      $contentpwd=(getpwnam($uname))[1];
+			      my $pwdcorrect = "0";
+			      my $pwauth_path="/usr/local/sbin/pwauth";
+			      unless ($contentpwd eq 'x') {
+				  $pwdcorrect=
+                                    (crypt($upass,$contentpwd) eq $contentpwd);
+			      } elsif (-e $pwauth_path) {
+				  open PWAUTH, "|$pwauth_path" or
+				      die "Cannot invoke authentication";
+				  print PWAUTH "$uname\n$upass\n";
+				  close PWAUTH;
+				  &Debug("exited pwauth with $? ($uname,$upass) ");
+				  $pwdcorrect=($? == 0);
+			      }
+			     if ($pwdcorrect) {
+				 my $execdir=$perlvar{'lonDaemons'};
+				 &Debug("Opening lcpasswd pipeline");
+				 my $pf = IO::File->new("|$execdir/lcpasswd > /home/www/lcpasswd.log");
+				 print $pf "$uname\n$npass\n$npass\n";
+				 close $pf;
+				 my $err = $?;
+				 my $result = ($err>0 ? 'pwchange_failure' 
+					       : 'ok');
+				 &logthis("Result of password change for $uname: ".
+					  &lcpasswdstrerror($?));
+				 print $client "$result\n";
+			     } else {
+				 print $client "non_authorized\n";
+			     }
+			  } else {
                             print $client "auth_mode_error\n";
                           }  
 		       } else {
@@ -492,6 +842,71 @@ sub make_new_child {
 		     } else {
 		       print $client "refused\n";
 		     }
+# -------------------------------------------------------------------- makeuser
+                   } elsif ($userinput =~ /^makeuser/) {
+		     &Debug("Make user received");
+    	             my $oldumask=umask(0077);
+		     if ($wasenc==1) {
+                       my 
+                       ($cmd,$udom,$uname,$umode,$npass)=split(/:/,$userinput);
+		       &Debug("cmd =".$cmd." $udom =".$udom.
+				    " uname=".$uname);
+                       chomp($npass);
+                       $npass=&unescape($npass);
+                       my $proname=propath($udom,$uname);
+                       my $passfilename="$proname/passwd";
+		       &Debug("Password file created will be:".
+				    $passfilename);
+                       if (-e $passfilename) {
+			   print $client "already_exists\n";
+                       } elsif ($udom ne $perlvar{'lonDefDomain'}) {
+                           print $client "not_right_domain\n";
+                       } else {
+                           @fpparts=split(/\//,$proname);
+                           $fpnow=$fpparts[0].'/'.$fpparts[1].'/'.$fpparts[2];
+                           $fperror='';
+                           for ($i=3;$i<=$#fpparts;$i++) {
+                               $fpnow.='/'.$fpparts[$i]; 
+                               unless (-e $fpnow) {
+				   unless (mkdir($fpnow,0777)) {
+                                      $fperror="error:$!";
+                                   }
+                               }
+                           }
+                           unless ($fperror) {
+			       my $result=&make_passwd_file($uname, $umode,$npass,
+							    $passfilename);
+			       print $client $result;
+                           } else {
+                               print $client "$fperror\n";
+                           }
+                       }
+		     } else {
+		       print $client "refused\n";
+		     }
+		     umask($oldumask);
+# -------------------------------------------------------------- changeuserauth
+                   } elsif ($userinput =~ /^changeuserauth/) {
+		       &Debug("Changing authorization");
+		      if ($wasenc==1) {
+                       my 
+		       ($cmd,$udom,$uname,$umode,$npass)=split(/:/,$userinput);
+                       chomp($npass);
+		       &Debug("cmd = ".$cmd." domain= ".$udom.
+			      "uname =".$uname." umode= ".$umode);
+                       $npass=&unescape($npass);
+                       my $proname=&propath($udom,$uname);
+                       my $passfilename="$proname/passwd";
+		       if ($udom ne $perlvar{'lonDefDomain'}) {
+                           print $client "not_right_domain\n";
+                       } else {
+			   my $result=&make_passwd_file($uname, $umode,$npass,
+							$passfilename);
+			   print $client $result;
+                       }
+		     } else {
+		       print $client "refused\n";
+		     }
 # ------------------------------------------------------------------------ home
                    } elsif ($userinput =~ /^home/) {
                        my ($cmd,$udom,$uname)=split(/:/,$userinput);
@@ -529,12 +944,13 @@ sub make_new_child {
                              $response=$ua->request($request,$transname);
 			      }
                              if ($response->is_error()) {
-				 unline($transname);
+				 unlink($transname);
                                  my $message=$response->status_line;
                                  &logthis(
                                   "LWP GET: $message for $fname ($remoteurl)");
                              } else {
 	                         if ($remoteurl!~/\.meta$/) {
+                                  my $ua=new LWP::UserAgent;
                                   my $mrequest=
                                    new HTTP::Request('GET',$remoteurl.'.meta');
                                   my $mresponse=
@@ -553,42 +969,65 @@ sub make_new_child {
 		       } else {
 			print $client "rejected\n";
                        }
+# -------------------------------------- fetch a user file from a remote server
+                   } elsif ($userinput =~ /^fetchuserfile/) {
+                      my ($cmd,$fname)=split(/:/,$userinput);
+		      my ($udom,$uname,$ufile)=split(/\//,$fname);
+                      my $udir=propath($udom,$uname).'/userfiles';
+                      unless (-e $udir) { mkdir($udir,0770); }
+                       if (-e $udir) {
+                       $ufile=~s/^[\.\~]+//;
+                       $ufile=~s/\///g;
+                       my $transname=$udir.'/'.$ufile;
+                       my $remoteurl='http://'.$clientip.'/userfiles/'.$fname;
+                             my $response;
+                              {
+                             my $ua=new LWP::UserAgent;
+                             my $request=new HTTP::Request('GET',"$remoteurl");
+                             $response=$ua->request($request,$transname);
+			      }
+                             if ($response->is_error()) {
+				 unlink($transname);
+                                 my $message=$response->status_line;
+                                 &logthis(
+                                  "LWP GET: $message for $fname ($remoteurl)");
+				 print $client "failed\n";
+                             } else {
+                                 print $client "ok\n";
+                             }
+                     } else {
+                       print $client "not_home\n";
+                     } 
+# ------------------------------------------ authenticate access to a user file
+                   } elsif ($userinput =~ /^tokenauthuserfile/) {
+                       my ($cmd,$fname,$session)=split(/:/,$userinput);
+                       chomp($session);
+                       $reply='non_auth';
+                       if (open(ENVIN,$perlvar{'lonIDsDir'}.'/'.
+                                      $session.'.id')) {
+                        while ($line=<ENVIN>) {
+			   if ($line=~/userfile\.$fname\=/) { $reply='ok'; }
+                        }
+                        close(ENVIN);
+                        print $client $reply."\n";
+		       } else {
+			print $client "invalid_token\n";
+                       }
 # ----------------------------------------------------------------- unsubscribe
                    } elsif ($userinput =~ /^unsub/) {
                        my ($cmd,$fname)=split(/:/,$userinput);
                        if (-e $fname) {
-                           if (unlink("$fname.$hostid{$clientip}")) {
-                              print $client "ok\n";
-			   } else {
-                              print $client "not_subscribed\n";
-			   }
+			   print $client &unsub($client,$fname,$clientip);
                        } else {
 			   print $client "not_found\n";
                        }
 # ------------------------------------------------------------------- subscribe
                    } elsif ($userinput =~ /^sub/) {
+		       print $client &subscribe($userinput,$clientip);
+# ------------------------------------------------------------- current version
+                   } elsif ($userinput =~ /^currentversion/) {
                        my ($cmd,$fname)=split(/:/,$userinput);
-                       my $ownership=ishome($fname);
-                       if ($ownership eq 'owner') {
-                        if (-e $fname) {
-			 if (-d $fname) {
-			   print $client "directory\n";
-                         } else {
-                           $now=time;
-                           { 
-                            my $sh=IO::File->new(">$fname.$hostid{$clientip}");
-                            print $sh "$clientip:$now\n";
-			   }
-                           $fname=~s/\/home\/httpd\/html\/res/raw/;
-                           $fname="http://$thisserver/".$fname;
-                           print $client "$fname\n";
-		         }
-                        } else {
-		      	   print $client "not_found\n";
-                        }
-		       } else {
-                        print $client "rejected\n";
-		       }
+		       print $client &currentversion($fname)."\n";
 # ------------------------------------------------------------------------- log
                    } elsif ($userinput =~ /^log/) {
                        my ($cmd,$udom,$uname,$what)=split(/:/,$userinput);
@@ -614,7 +1053,7 @@ sub make_new_child {
                        chomp($what);
                        my $proname=propath($udom,$uname);
                        my $now=time;
-                       {
+                       unless ($namespace=~/^nohist\_/) {
 			   my $hfh;
 			   if (
                              $hfh=IO::File->new(">>$proname/$namespace.hist")
@@ -639,9 +1078,13 @@ sub make_new_child {
                       }
 # -------------------------------------------------------------------- rolesput
                    } elsif ($userinput =~ /^rolesput/) {
+		       &Debug("rolesput");
 		    if ($wasenc==1) {
                        my ($cmd,$exedom,$exeuser,$udom,$uname,$what)
                           =split(/:/,$userinput);
+		       &Debug("cmd = ".$cmd." exedom= ".$exedom.
+				    "user = ".$exeuser." udom=".$udom.
+				    "what = ".$what);
                        my $namespace='roles';
                        chomp($what);
                        my $proname=propath($udom,$uname);
@@ -658,7 +1101,11 @@ sub make_new_child {
       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_WRCREAT,0640)) {
                            foreach $pair (@pairs) {
 			       ($key,$value)=split(/=/,$pair);
+			       &ManagePermissions($key, $udom, $uname,
+						  &GetAuthType( $udom, 
+								$uname));
                                $hash{$key}=$value;
+			       
                            }
 			   if (untie(%hash)) {
                               print $client "ok\n";
@@ -739,7 +1186,7 @@ sub make_new_child {
                        chomp($what);
                        my $proname=propath($udom,$uname);
                        my $now=time;
-                       {
+                       unless ($namespace=~/^nohist\_/) {
 			   my $hfh;
 			   if (
                              $hfh=IO::File->new(">>$proname/$namespace.hist")
@@ -781,21 +1228,34 @@ sub make_new_child {
                        }
 # ------------------------------------------------------------------------ dump
                    } elsif ($userinput =~ /^dump/) {
-                       my ($cmd,$udom,$uname,$namespace)
+                       my ($cmd,$udom,$uname,$namespace,$regexp)
                           =split(/:/,$userinput);
                        $namespace=~s/\//\_/g;
                        $namespace=~s/\W//g;
-                       my $proname=propath($udom,$uname);
+                       if (defined($regexp)) {
+                          $regexp=&unescape($regexp);
+		       } else {
+                          $regexp='.';
+		       }
                        my $qresult='';
-      if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER,0640)) {
-                           foreach $key (keys %hash) {
-                               $qresult.="$key=$hash{$key}&";
-                           }
-			   if (untie(%hash)) {
-		              $qresult=~s/\&$//;
-                              print $client "$qresult\n";
+                       my $proname=propath($udom,$uname);
+    if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER(),0640)) {
+                           study($regexp);
+                           while (($key,$value) = each(%hash)) {
+                               if ($regexp eq '.') {
+                                   $qresult.=$key.'='.$value.'&';
+                               } else {
+                                   my $unescapeKey = &unescape($key);
+                                   if (eval('$unescapeKey=~/$regexp/')) {
+                                       $qresult.="$key=$value&";
+                                   }
+                               }
+                           }
+                           if (untie(%hash)) {
+                               chop($qresult);
+                               print $client "$qresult\n";
                            } else {
-                              print $client "error:$!\n";
+                               print $client "error:$!\n";
                            }
                        } else {
                            print $client "error:$!\n";
@@ -810,7 +1270,7 @@ sub make_new_child {
                        chomp($what);
                        my $proname=propath($udom,$uname);
                        my $now=time;
-                       {
+                       unless ($namespace=~/^nohist\_/) {
 			   my $hfh;
 			   if (
                              $hfh=IO::File->new(">>$proname/$namespace.hist")
@@ -829,7 +1289,8 @@ sub make_new_child {
                                $allkeys.=$key.':';
                                $hash{"$version:$rid:$key"}=$value;
                            }
-                           $allkeys=~s/:$//;
+                           $hash{"$version:$rid:timestamp"}=$now;
+                           $allkeys.='timestamp';
                            $hash{"$version:keys:$rid"}=$allkeys;
 			   if (untie(%hash)) {
                               print $client "ok\n";
@@ -873,19 +1334,40 @@ sub make_new_child {
                        } else {
                            print $client "error:$!\n";
                        }
+# -------------------------------------------------------------------- chatsend
+                   } elsif ($userinput =~ /^chatsend/) {
+                       my ($cmd,$cdom,$cnum,$newpost)=split(/\:/,$userinput);
+                       &chatadd($cdom,$cnum,$newpost);
+                       print $client "ok\n";
+# -------------------------------------------------------------------- chatretr
+                   } elsif ($userinput =~ /^chatretr/) {
+                       my ($cmd,$cdom,$cnum)=split(/\:/,$userinput);
+                       my $reply='';
+                       foreach (&getchat($cdom,$cnum)) {
+			   $reply.=&escape($_).':';
+                       }
+                       $reply=~s/\:$//;
+                       print $client $reply."\n";
 # ------------------------------------------------------------------- querysend
                    } elsif ($userinput =~ /^querysend/) {
-                       my ($cmd,$query)=split(/:/,$userinput);
+                       my ($cmd,$query,
+			   $arg1,$arg2,$arg3)=split(/\:/,$userinput);
 		       $query=~s/\n*$//g;
-                     print $client sqlreply("$hostid{$clientip}\&$query")."\n";
+		       print $client "".
+			       sqlreply("$hostid{$clientip}\&$query".
+					"\&$arg1"."\&$arg2"."\&$arg3")."\n";
 # ------------------------------------------------------------------ queryreply
                    } elsif ($userinput =~ /^queryreply/) {
                        my ($cmd,$id,$reply)=split(/:/,$userinput); 
 		       my $store;
                        my $execdir=$perlvar{'lonDaemons'};
                        if ($store=IO::File->new(">$execdir/tmp/$id")) {
+			   $reply=~s/\&/\n/g;
 			   print $store $reply;
 			   close $store;
+			   my $store2=IO::File->new(">$execdir/tmp/$id.end");
+			   print $store2 "done\n";
+			   close $store2;
 			   print $client "ok\n";
 		       }
 		       else {
@@ -979,34 +1461,58 @@ sub make_new_child {
                        my $ulsout='';
                        my $ulsfn;
                        if (-e $ulsdir) {
-                          while ($ulsfn=<$ulsdir/*>) {
-			     my @ulsstats=stat($ulsfn);
-                             $ulsout.=$ulsfn.'&'.join('&',@ulsstats).':';
-                          }
-		       } else {
+                           if(-d $ulsdir) {
+                               if (opendir(LSDIR,$ulsdir)) {
+                                   while ($ulsfn=readdir(LSDIR)) {
+                                       my @ulsstats=stat($ulsdir.'/'.$ulsfn);
+                                       $ulsout.=$ulsfn.'&'.
+                                                join('&',@ulsstats).':';
+                                   }
+                                   closedir(LSDIR);
+                               }
+                           } else {
+                               my @ulsstats=stat($ulsdir);
+                               $ulsout.=$ulsfn.'&'.join('&',@ulsstats).':';
+                           }
+                       } else {
                           $ulsout='no_such_dir';
                        }
                        if ($ulsout eq '') { $ulsout='empty'; }
                        print $client "$ulsout\n";
+# ------------------------------------------------------------------ Hanging up
+                   } elsif (($userinput =~ /^exit/) ||
+                            ($userinput =~ /^init/)) {
+                       &logthis(
+      "Client $clientip ($hostid{$clientip}) hanging up: $userinput");
+                       print $client "bye\n";
+                       $client->close();
+		       last;
 # ------------------------------------------------------------- unknown command
                    } else {
                        # unknown command
                        print $client "unknown_cmd\n";
                    }
-# ------------------------------------------------------ client unknown, refuse
+# -------------------------------------------------------------------- complete
+		   alarm(0);
+                   &status('Listening to '.$hostid{$clientip});
 	       }
+# --------------------------------------------- client unknown or fishy, refuse
             } else {
 	        print $client "refused\n";
+                $client->close();
                 &logthis("<font color=blue>WARNING: "
                 ."Rejected client $clientip, closing connection</font>");
-            }              
-            &logthis("<font color=red>CRITICAL: "
-                    ."Disconnect from $clientip ($hostid{$clientip})</font>");
+            }
+	}              
+
 # =============================================================================
-        }
-    
+       
+	&logthis("<font color=red>CRITICAL: "
+		 ."Disconnect from $clientip ($hostid{$clientip})</font>");    
         # tidy up gracefully and finish
     
+        $server->close();
+
         # this exit is VERY important, otherwise the child will become
         # a producer of more and more children, forking yourself into
         # process death.
@@ -1014,27 +1520,593 @@ sub make_new_child {
     }
 }
 
-# grabs exception and records it to log before exiting
-sub catchexception {
-    my ($signal)=@_;
-    &logthis("<font color=red>CRITICAL: "
-     ."ABNORMAL EXIT. Child $$ for server $wasserver died through "
-     ."$signal with this parameter->[$@]</font>");
-    die($@);
+
+#
+#   Checks to see if the input roleput request was to set
+# an author role.  If so, invokes the lchtmldir script to set
+# up a correct public_html 
+# Parameters:
+#    request   - The request sent to the rolesput subchunk.
+#                We're looking for  /domain/_au
+#    domain    - The domain in which the user is having roles doctored.
+#    user      - Name of the user for which the role is being put.
+#    authtype  - The authentication type associated with the user.
+#
+sub ManagePermissions
+{
+    my $request = shift;
+    my $domain  = shift;
+    my $user    = shift;
+    my $authtype= shift;
+
+    # See if the request is of the form /$domain/_au
+
+    if($request =~ /^(\/$domain\/_au)$/) { # It's an author rolesput...
+	my $execdir = $perlvar{'lonDaemons'};
+	my $userhome= "/home/$user" ;
+	Debug("system $execdir/lchtmldir $userhome $system $authtype");
+	system("$execdir/lchtmldir $userhome $user $authtype");
+    }
 }
+#
+#   GetAuthType - Determines the authorization type of a user in a domain.
 
-# grabs exception and records it to log before exiting
-# NOTE: we must NOT use the regular (non-overrided) die function in
-# the code because a handler CANNOT be attached to it
-# (despite what some of the documentation says about SIG{__DIE__}.
-sub catchdie {
-    my ($message)=@_;
-    &logthis("<font color=red>CRITICAL: "
-     ."ABNORMAL EXIT. Child $$ for server $wasserver died through "
-     ."\_\_DIE\_\_ with this parameter->[$message]</font>");
-    die($message);
+#     Returns the authorization type or nouser if there is no such user.
+#
+sub GetAuthType 
+{
+    my $domain = shift;
+    my $user   = shift;
+
+    Debug("GetAuthType( $domain, $user ) \n");
+    my $proname    = &propath($domain, $user); 
+    my $passwdfile = "$proname/passwd";
+    if( -e $passwdfile ) {
+	my $pf = IO::File->new($passwdfile);
+	my $realpassword = <$pf>;
+	chomp($realpassword);
+	Debug("Password info = $realpassword\n");
+	my ($authtype, $contentpwd) = split(/:/, $realpassword);
+	Debug("Authtype = $authtype, content = $contentpwd\n");
+	my $availinfo = '';
+	if($authtype eq 'krb4' or $authtype eq 'krb5') {
+	    $availinfo = $contentpwd;
+	}
+
+	return "$authtype:$availinfo";
+    }
+    else {
+	Debug("Returning nouser");
+	return "nouser";
+    }
+}
+
+sub addline {
+    my ($fname,$hostid,$ip,$newline)=@_;
+    my $contents;
+    my $found=0;
+    my $expr='^'.$hostid.':'.$ip.':';
+    $expr =~ s/\./\\\./g;
+    if ($sh=IO::File->new("$fname.subscription")) {
+	while (my $subline=<$sh>) {
+	    if ($subline !~ /$expr/) {$contents.= $subline;} else {$found=1;}
+	}
+	$sh->close();
+    }
+    $sh=IO::File->new(">$fname.subscription");
+    if ($contents) { print $sh $contents; }
+    if ($newline) { print $sh $newline; }
+    $sh->close();
+    return $found;
+}
+
+sub getchat {
+    my ($cdom,$cname)=@_;
+    my %hash;
+    my $proname=&propath($cdom,$cname);
+    my @entries=();
+    if (tie(%hash,'GDBM_File',"$proname/nohist_chatroom.db",
+	    &GDBM_READER(),0640)) {
+	@entries=map { $_.':'.$hash{$_} } sort keys %hash;
+	untie %hash;
+    }
+    return @entries;
+}
+
+sub chatadd {
+    my ($cdom,$cname,$newchat)=@_;
+    my %hash;
+    my $proname=&propath($cdom,$cname);
+    my @entries=();
+    if (tie(%hash,'GDBM_File',"$proname/nohist_chatroom.db",
+	    &GDBM_WRCREAT(),0640)) {
+	@entries=map { $_.':'.$hash{$_} } sort keys %hash;
+	my $time=time;
+	my ($lastid)=($entries[$#entries]=~/^(\w+)\:/);
+	my ($thentime,$idnum)=split(/\_/,$lastid);
+	my $newid=$time.'_000000';
+	if ($thentime==$time) {
+	    $idnum=~s/^0+//;
+	    $idnum++;
+	    $idnum=substr('000000'.$idnum,-6,6);
+	    $newid=$time.'_'.$idnum;
+	}
+	$hash{$newid}=$newchat;
+	my $expired=$time-3600;
+	foreach (keys %hash) {
+	    my ($thistime)=($_=~/(\d+)\_/);
+	    if ($thistime<$expired) {
+		delete $hash{$_};
+	    }
+	}
+	untie %hash;
+    }
+}
+
+sub unsub {
+    my ($fname,$clientip)=@_;
+    my $result;
+    if (unlink("$fname.$hostid{$clientip}")) {
+	$result="ok\n";
+    } else {
+	$result="not_subscribed\n";
+    }
+    if (-e "$fname.subscription") {
+	my $found=&addline($fname,$hostid{$clientip},$clientip,'');
+	if ($found) { $result="ok\n"; }
+    } else {
+	if ($result != "ok\n") { $result="not_subscribed\n"; }
+    }
+    return $result;
+}
+
+sub currentversion {
+    my $fname=shift;
+    my $version=-1;
+    my $ulsdir='';
+    if ($fname=~/^(.+)\/[^\/]+$/) {
+       $ulsdir=$1;
+    }
+    $fname=~s/\.\d+\.(\w+(?:\.meta)*)$/\.$1/;
+    $fname=~s/\.(\w+(?:\.meta)*)$/\.\(\\d\+\)\.$1\$/;
+
+    if (-e $fname) { $version=1; }
+    if (-e $ulsdir) {
+       if(-d $ulsdir) {
+          if (opendir(LSDIR,$ulsdir)) {
+             while ($ulsfn=readdir(LSDIR)) {
+# see if this is a regular file (ignore links produced earlier)
+                 my $thisfile=$ulsdir.'/'.$ulsfn;
+                 unless (-l $thisfile) {
+		    if ($thisfile=~/$fname/) {
+		        if ($1>$version) { $version=$1; }
+                    }
+		 }
+             }
+             closedir(LSDIR);
+             $version++;
+          }
+      }
+   }
+   return $version;
+}
+
+sub thisversion {
+    my $fname=shift;
+    my $version=-1;
+    if ($fname=~/\.(\d+)\.\w+(?:\.meta)*$/) {
+	$version=$1;
+    }
+    return $version;
+}
+
+sub subscribe {
+    my ($userinput,$clientip)=@_;
+    my $result;
+    my ($cmd,$fname)=split(/:/,$userinput);
+    my $ownership=&ishome($fname);
+    if ($ownership eq 'owner') {
+# explitly asking for the current version?
+        unless (-e $fname) {
+            my $currentversion=&currentversion($fname);
+	    if (&thisversion($fname)==$currentversion) {
+                if ($fname=~/^(.+)\.\d+\.(\w+(?:\.meta)*)$/) {
+		    my $root=$1;
+                    my $extension=$2;
+                    symlink($root.'.'.$extension,
+                            $root.'.'.$currentversion.'.'.$extension);
+                    unless ($extension=~/\.meta$/) {
+                       symlink($root.'.'.$extension.'.meta',
+                            $root.'.'.$currentversion.'.'.$extension.'.meta');
+		    }
+                }
+            }
+        }
+	if (-e $fname) {
+	    if (-d $fname) {
+		$result="directory\n";
+	    } else {
+		if (-e "$fname.$hostid{$clientip}") {&unsub($fname,$clientip);}
+		$now=time;
+		my $found=&addline($fname,$hostid{$clientip},$clientip,
+				   "$hostid{$clientip}:$clientip:$now\n");
+		if ($found) { $result="$fname\n"; }
+		# if they were subscribed to only meta data, delete that
+                # subscription, when you subscribe to a file you also get
+                # the metadata
+		unless ($fname=~/\.meta$/) { &unsub("$fname.meta",$clientip); }
+		$fname=~s/\/home\/httpd\/html\/res/raw/;
+		$fname="http://$thisserver/".$fname;
+		$result="$fname\n";
+	    }
+	} else {
+	    $result="not_found\n";
+	}
+    } else {
+	$result="rejected\n";
+    }
+    return $result;
 }
 
+sub make_passwd_file {
+    my ($uname, $umode,$npass,$passfilename)=@_;
+    my $result="ok\n";
+    if ($umode eq 'krb4' or $umode eq 'krb5') {
+	{
+	    my $pf = IO::File->new(">$passfilename");
+	    print $pf "$umode:$npass\n";
+	}
+    } elsif ($umode eq 'internal') {
+	my $salt=time;
+	$salt=substr($salt,6,2);
+	my $ncpass=crypt($npass,$salt);
+	{
+	    &Debug("Creating internal auth");
+	    my $pf = IO::File->new(">$passfilename");
+	    print $pf "internal:$ncpass\n"; 
+	}
+    } elsif ($umode eq 'localauth') {
+	{
+	    my $pf = IO::File->new(">$passfilename");
+	    print $pf "localauth:$npass\n";
+	}
+    } elsif ($umode eq 'unix') {
+	{
+	    my $execpath="$perlvar{'lonDaemons'}/"."lcuseradd";
+	    {
+		&Debug("Executing external: ".$execpath);
+		&Debug("user  = ".$uname.", Password =". $npass);
+		my $se = IO::File->new("|$execpath > /home/www/lcuseradd.log");
+		print $se "$uname\n";
+		print $se "$npass\n";
+		print $se "$npass\n";
+	    }
+	    my $useraddok = $?;
+	    if($useraddok > 0) {
+		&logthis("Failed lcuseradd: ".&lcuseraddstrerror($useraddok));
+	    }
+	    my $pf = IO::File->new(">$passfilename");
+	    print $pf "unix:\n";
+	}
+    } elsif ($umode eq 'none') {
+	{
+	    my $pf = IO::File->new(">$passfilename");
+	    print $pf "none:\n";
+	}
+    } else {
+	$result="auth_mode_error\n";
+    }
+    return $result;
+}
+
+# ----------------------------------- POD (plain old documentation, CPAN style)
+
+=head1 NAME
+
+lond - "LON Daemon" Server (port "LOND" 5663)
+
+=head1 SYNOPSIS
+
+Usage: B<lond>
+
+Should only be run as user=www.  This is a command-line script which
+is invoked by B<loncron>.  There is no expectation that a typical user
+will manually start B<lond> from the command-line.  (In other words,
+DO NOT START B<lond> YOURSELF.)
+
+=head1 DESCRIPTION
+
+There are two characteristics associated with the running of B<lond>,
+PROCESS MANAGEMENT (starting, stopping, handling child processes)
+and SERVER-SIDE ACTIVITIES (password authentication, user creation,
+subscriptions, etc).  These are described in two large
+sections below.
+
+B<PROCESS MANAGEMENT>
+
+Preforker - server who forks first. Runs as a daemon. HUPs.
+Uses IDEA encryption
+
+B<lond> forks off children processes that correspond to the other servers
+in the network.  Management of these processes can be done at the
+parent process level or the child process level.
+
+B<logs/lond.log> is the location of log messages.
+
+The process management is now explained in terms of linux shell commands,
+subroutines internal to this code, and signal assignments:
+
+=over 4
+
+=item *
+
+PID is stored in B<logs/lond.pid>
+
+This is the process id number of the parent B<lond> process.
+
+=item *
+
+SIGTERM and SIGINT
+
+Parent signal assignment:
+ $SIG{INT}  = $SIG{TERM} = \&HUNTSMAN;
+
+Child signal assignment:
+ $SIG{INT}  = 'DEFAULT'; (and SIGTERM is DEFAULT also)
+(The child dies and a SIGALRM is sent to parent, awaking parent from slumber
+ to restart a new child.)
+
+Command-line invocations:
+ B<kill> B<-s> SIGTERM I<PID>
+ B<kill> B<-s> SIGINT I<PID>
+
+Subroutine B<HUNTSMAN>:
+ This is only invoked for the B<lond> parent I<PID>.
+This kills all the children, and then the parent.
+The B<lonc.pid> file is cleared.
+
+=item *
+
+SIGHUP
+
+Current bug:
+ This signal can only be processed the first time
+on the parent process.  Subsequent SIGHUP signals
+have no effect.
+
+Parent signal assignment:
+ $SIG{HUP}  = \&HUPSMAN;
+
+Child signal assignment:
+ none (nothing happens)
+
+Command-line invocations:
+ B<kill> B<-s> SIGHUP I<PID>
+
+Subroutine B<HUPSMAN>:
+ This is only invoked for the B<lond> parent I<PID>,
+This kills all the children, and then the parent.
+The B<lond.pid> file is cleared.
+
+=item *
+
+SIGUSR1
+
+Parent signal assignment:
+ $SIG{USR1} = \&USRMAN;
+
+Child signal assignment:
+ $SIG{USR1}= \&logstatus;
+
+Command-line invocations:
+ B<kill> B<-s> SIGUSR1 I<PID>
+
+Subroutine B<USRMAN>:
+ When invoked for the B<lond> parent I<PID>,
+SIGUSR1 is sent to all the children, and the status of
+each connection is logged.
+
+=item *
+
+SIGCHLD
+
+Parent signal assignment:
+ $SIG{CHLD} = \&REAPER;
+
+Child signal assignment:
+ none
+
+Command-line invocations:
+ B<kill> B<-s> SIGCHLD I<PID>
+
+Subroutine B<REAPER>:
+ This is only invoked for the B<lond> parent I<PID>.
+Information pertaining to the child is removed.
+The socket port is cleaned up.
+
+=back
+
+B<SERVER-SIDE ACTIVITIES>
+
+Server-side information can be accepted in an encrypted or non-encrypted
+method.
+
+=over 4
+
+=item ping
+
+Query a client in the hosts.tab table; "Are you there?"
+
+=item pong
+
+Respond to a ping query.
+
+=item ekey
+
+Read in encrypted key, make cipher.  Respond with a buildkey.
+
+=item load
+
+Respond with CPU load based on a computation upon /proc/loadavg.
+
+=item currentauth
+
+Reply with current authentication information (only over an
+encrypted channel).
+
+=item auth
+
+Only over an encrypted channel, reply as to whether a user's
+authentication information can be validated.
+
+=item passwd
+
+Allow for a password to be set.
+
+=item makeuser
+
+Make a user.
+
+=item passwd
+
+Allow for authentication mechanism and password to be changed.
+
+=item home
+
+Respond to a question "are you the home for a given user?"
+
+=item update
+
+Update contents of a subscribed resource.
+
+=item unsubscribe
+
+The server is unsubscribing from a resource.
+
+=item subscribe
+
+The server is subscribing to a resource.
+
+=item log
+
+Place in B<logs/lond.log>
+
+=item put
+
+stores hash in namespace
+
+=item rolesput
+
+put a role into a user's environment
+
+=item get
+
+returns hash with keys from array
+reference filled in from namespace
+
+=item eget
+
+returns hash with keys from array
+reference filled in from namesp (encrypts the return communication)
+
+=item rolesget
+
+get a role from a user's environment
+
+=item del
+
+deletes keys out of array from namespace
+
+=item keys
+
+returns namespace keys
+
+=item dump
+
+dumps the complete (or key matching regexp) namespace into a hash
+
+=item store
+
+stores hash permanently
+for this url; hashref needs to be given and should be a \%hashname; the
+remaining args aren't required and if they aren't passed or are '' they will
+be derived from the ENV
+
+=item restore
+
+returns a hash for a given url
+
+=item querysend
+
+Tells client about the lonsql process that has been launched in response
+to a sent query.
+
+=item queryreply
+
+Accept information from lonsql and make appropriate storage in temporary
+file space.
+
+=item idput
+
+Defines usernames as corresponding to IDs.  (These "IDs" are unique identifiers
+for each student, defined perhaps by the institutional Registrar.)
+
+=item idget
+
+Returns usernames corresponding to IDs.  (These "IDs" are unique identifiers
+for each student, defined perhaps by the institutional Registrar.)
+
+=item tmpput
+
+Accept and store information in temporary space.
+
+=item tmpget
+
+Send along temporarily stored information.
+
+=item ls
+
+List part of a user's directory.
+
+=item Hanging up (exit or init)
+
+What to do when a client tells the server that they (the client)
+are leaving the network.
+
+=item unknown command
+
+If B<lond> is sent an unknown command (not in the list above),
+it replys to the client "unknown_cmd".
+
+=item UNKNOWN CLIENT
+
+If the anti-spoofing algorithm cannot verify the client,
+the client is rejected (with a "refused" message sent
+to the client, and the connection is closed.
+
+=back
+
+=head1 PREREQUISITES
+
+IO::Socket
+IO::File
+Apache::File
+Symbol
+POSIX
+Crypt::IDEA
+LWP::UserAgent()
+GDBM_File
+Authen::Krb4
+Authen::Krb5
+
+=head1 COREQUISITES
+
+=head1 OSNAMES
+
+linux
 
+=head1 SCRIPT CATEGORIES
 
+Server/Process
 
+=cut