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Diff for /loncom/lond between versions 1.46 and 1.198

version 1.46, 2001/04/02 14:43:17 version 1.198, 2004/06/17 22:37:52
Line 1 Line 1
 #!/usr/bin/perl  #!/usr/bin/perl
 # The LearningOnline Network  # The LearningOnline Network
 # lond "LON Daemon" Server (port "LOND" 5663)  # lond "LON Daemon" Server (port "LOND" 5663)
 # 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,  # $Id$
 # 10/7,10/8,10/9,10/11,10/13,10/15,11/4,11/16,  #
 # 12/7,12/15,01/06,01/11,01/12,01/14,2/8,  # Copyright Michigan State University Board of Trustees
 # 03/07,05/31 Gerd Kortemeyer  #
 # 06/26 Scott Harrison  # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
 # 06/29,06/30,07/14,07/15,07/17,07/20,07/25,09/18 Gerd Kortemeyer  #
 # 12/05 Scott Harrison  # LON-CAPA is free software; you can redistribute it and/or modify
 # 12/05,12/13,12/29 Gerd Kortemeyer  # it under the terms of the GNU General Public License as published by
 # Jan 01 Scott Harrison  # the Free Software Foundation; either version 2 of the License, or 
 # 02/12 Gerd Kortemeyer  # (at your option) any later version.
 # 03/15 Scott Harrison  #
 # 03/24 Gerd Kortemeyer  # LON-CAPA is distributed in the hope that it will be useful,
 #  # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # based on "Perl Cookbook" ISBN 1-56592-243-3  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # preforker - server who forks first  # GNU General Public License for more details.
 # runs as a daemon  #
 # HUPs  # You should have received a copy of the GNU General Public License
 # uses IDEA encryption  # 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/
   #
   
   use strict;
   use lib '/home/httpd/lib/perl/';
   use LONCAPA::Configuration;
   
 use IO::Socket;  use IO::Socket;
 use IO::File;  use IO::File;
 use Apache::File;  #use Apache::File;
 use Symbol;  use Symbol;
 use POSIX;  use POSIX;
 use Crypt::IDEA;  use Crypt::IDEA;
 use LWP::UserAgent();  use LWP::UserAgent();
 use GDBM_File;  use GDBM_File;
 use Authen::Krb4;  use Authen::Krb4;
   use Authen::Krb5;
   use lib '/home/httpd/lib/perl/';
   use localauth;
   use localenroll;
   use File::Copy;
   use LONCAPA::ConfigFileEdit;
   use LONCAPA::lonlocal;
   use LONCAPA::lonssl;
   
   my $DEBUG = 11;       # Non zero to enable debug log entries.
   
   my $status='';
   my $lastlog='';
   
   my $VERSION='$Revision$'; #' stupid emacs
   my $remoteVERSION;
   my $currenthostid;
   my $currentdomainid;
   
   my $client;
   my $clientip; # IP address of client.
   my $clientdns; # DNS name of client.
   my $clientname; # LonCAPA name of client.
   
   my $server;
   my $thisserver; # DNS of us.
   
   my $keymode;
   
   # 
   #   Connection type is:
   #      client                   - All client actions are allowed
   #      manager                  - only management functions allowed.
   #      both                     - Both management and client actions are allowed
   #
   
   my $ConnectionType;
   
   my %hostid; # ID's for hosts in cluster by ip.
   my %hostdom; # LonCAPA domain for hosts in cluster.
   my %hostip; # IPs for hosts in cluster.
   my %hostdns; # ID's of hosts looked up by DNS name.
   
   my %managers; # Ip -> manager names
   
   my %perlvar; # Will have the apache conf defined perl vars.
   
   #
   #  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 Unable to make www member of users's group",
       "lcuseradd Unable to su to root",
       "lcuseradd Unable to set password",
       "lcuseradd Usrname has invalid characters",
       "lcuseradd Password has an invalid character",
       "lcuseradd User already exists",
       "lcuseradd Could not add user.",
       "lcuseradd Password mismatch");
   
   
   #------------------------------------------------------------------------
   #
   #   LocalConnection
   #     Completes the formation of a locally authenticated connection.
   #     This function will ensure that the 'remote' client is really the
   #     local host.  If not, the connection is closed, and the function fails.
   #     If so, initcmd is parsed for the name of a file containing the
   #     IDEA session key.  The fie is opened, read, deleted and the session
   #     key returned to the caller.
   #
   # Parameters:
   #   $Socket      - Socket open on client.
   #   $initcmd     - The full text of the init command.
   #
   # Implicit inputs:
   #    $clientdns  - The DNS name of the remote client.
   #    $thisserver - Our DNS name.
   #
   # Returns:
   #     IDEA session key on success.
   #     undef on failure.
   #
   sub LocalConnection {
       my ($Socket, $initcmd) = @_;
       Debug("Attempting local connection: $initcmd client: $clientdns me: $thisserver");
       if($clientdns ne $thisserver) {
    &logthis('<font color="red"> LocalConnection rejecting non local: '
    ."$clientdns ne $thisserver </font>");
    close $Socket;
    return undef;
       } 
       else {
    chomp($initcmd); # Get rid of \n in filename.
    my ($init, $type, $name) = split(/:/, $initcmd);
    Debug(" Init command: $init $type $name ");
   
    # Require that $init = init, and $type = local:  Otherwise
    # the caller is insane:
   
    if(($init ne "init") && ($type ne "local")) {
       &logthis('<font color = "red"> LocalConnection: caller is insane! '
        ."init = $init, and type = $type </font>");
       close($Socket);;
       return undef;
   
    }
    #  Now get the key filename:
   
    my $IDEAKey = lonlocal::ReadKeyFile($name);
    return $IDEAKey;
       }
   }
   #------------------------------------------------------------------------------
   #
   #  SSLConnection
   #   Completes the formation of an ssh authenticated connection. The
   #   socket is promoted to an ssl socket.  If this promotion and the associated
   #   certificate exchange are successful, the IDEA key is generated and sent
   #   to the remote peer via the SSL tunnel. The IDEA key is also returned to
   #   the caller after the SSL tunnel is torn down.
   #
   # Parameters:
   #   Name              Type             Purpose
   #   $Socket          IO::Socket::INET  Plaintext socket.
   #
   # Returns:
   #    IDEA key on success.
   #    undef on failure.
   #
   sub SSLConnection {
       my $Socket   = shift;
   
       Debug("SSLConnection: ");
       my $KeyFile         = lonssl::KeyFile();
       if(!$KeyFile) {
    my $err = lonssl::LastError();
    &logthis("<font color=\"red\"> CRITICAL"
    ."Can't get key file $err </font>");
    return undef;
       }
       my ($CACertificate,
    $Certificate) = lonssl::CertificateFile();
   
   
       # If any of the key, certificate or certificate authority 
       # certificate filenames are not defined, this can't work.
   
       if((!$Certificate) || (!$CACertificate)) {
    my $err = lonssl::LastError();
    &logthis("<font color=\"red\"> CRITICAL"
    ."Can't get certificates: $err </font>");
   
    return undef;
       }
       Debug("Key: $KeyFile CA: $CACertificate Cert: $Certificate");
   
       # Indicate to our peer that we can procede with
       # a transition to ssl authentication:
   
       print $Socket "ok:ssl\n";
   
       Debug("Approving promotion -> ssl");
       #  And do so:
   
       my $SSLSocket = lonssl::PromoteServerSocket($Socket,
    $CACertificate,
    $Certificate,
    $KeyFile);
       if(! ($SSLSocket) ) { # SSL socket promotion failed.
    my $err = lonssl::LastError();
    &logthis("<font color=\"red\"> CRITICAL "
    ."SSL Socket promotion failed: $err </font>");
    return undef;
       }
       Debug("SSL Promotion successful");
   
       # 
       #  The only thing we'll use the socket for is to send the IDEA key
       #  to the peer:
   
       my $Key = lonlocal::CreateCipherKey();
       print $SSLSocket "$Key\n";
   
       lonssl::Close($SSLSocket); 
   
       Debug("Key exchange complete: $Key");
   
       return $Key;
   }
   #
   #     InsecureConnection: 
   #        If insecure connections are allowd,
   #        exchange a challenge with the client to 'validate' the
   #        client (not really, but that's the protocol):
   #        We produce a challenge string that's sent to the client.
   #        The client must then echo the challenge verbatim to us.
   #
   #  Parameter:
   #      Socket      - Socket open on the client.
   #  Returns:
   #      1           - success.
   #      0           - failure (e.g.mismatch or insecure not allowed).
   #
   sub InsecureConnection {
       my $Socket  =  shift;
   
       #   Don't even start if insecure connections are not allowed.
   
       if(! $perlvar{londAllowInsecure}) { # Insecure connections not allowed.
    return 0;
       }
   
       #   Fabricate a challenge string and send it..
   
       my $challenge = "$$".time; # pid + time.
       print $Socket "$challenge\n";
       &status("Waiting for challenge reply");
   
       my $answer = <$Socket>;
       $answer    =~s/\W//g;
       if($challenge eq $answer) {
    return 1;
       } 
       else {
    logthis("<font color='blue'>WARNING client did not respond to challenge</font>");
    &status("No challenge reqply");
    return 0;
       }
       
   
   }
   
   #
   #   GetCertificate: Given a transaction that requires a certificate,
   #   this function will extract the certificate from the transaction
   #   request.  Note that at this point, the only concept of a certificate
   #   is the hostname to which we are connected.
   #
   #   Parameter:
   #      request   - The request sent by our client (this parameterization may
   #                  need to change when we really use a certificate granting
   #                  authority.
   #
   sub GetCertificate {
       my $request = shift;
   
       return $clientip;
   }
   
   #
   #   Return true if client is a manager.
   #
   sub isManager {
       return (($ConnectionType eq "manager") || ($ConnectionType eq "both"));
   }
   #
   #   Return tru if client can do client functions
   #
   sub isClient {
       return (($ConnectionType eq "client") || ($ConnectionType eq "both"));
   }
   
   
   #
   #   ReadManagerTable: Reads in the current manager table. For now this is
   #                     done on each manager authentication because:
   #                     - These authentications are not frequent
   #                     - This allows dynamic changes to the manager table
   #                       without the need to signal to the lond.
   #
   
   sub ReadManagerTable {
   
       #   Clean out the old table first..
   
      foreach my $key (keys %managers) {
         delete $managers{$key};
      }
   
      my $tablename = $perlvar{'lonTabDir'}."/managers.tab";
      if (!open (MANAGERS, $tablename)) {
         logthis('<font color="red">No manager table.  Nobody can manage!!</font>');
         return;
      }
      while(my $host = <MANAGERS>) {
         chomp($host);
         if ($host =~ "^#") {                  # Comment line.
            logthis('<font color="green"> Skipping line: '. "$host</font>\n");
            next;
         }
         if (!defined $hostip{$host}) { # This is a non cluster member
       #  The entry is of the form:
       #    cluname:hostname
       #  cluname - A 'cluster hostname' is needed in order to negotiate
       #            the host key.
       #  hostname- The dns name of the host.
       #
             my($cluname, $dnsname) = split(/:/, $host);
             
             my $ip = gethostbyname($dnsname);
             if(defined($ip)) {                 # bad names don't deserve entry.
               my $hostip = inet_ntoa($ip);
               $managers{$hostip} = $cluname;
               logthis('<font color="green"> registering manager '.
                       "$dnsname as $cluname with $hostip </font>\n");
            }
         } else {
            logthis('<font color="green"> existing host'." $host</font>\n");
            $managers{$hostip{$host}} = $host;  # Use info from cluster tab if clumemeber
         }
      }
   }
   
   #
   #  ValidManager: Determines if a given certificate represents a valid manager.
   #                in this primitive implementation, the 'certificate' is
   #                just the connecting loncapa client name.  This is checked
   #                against a valid client list in the configuration.
   #
   #                  
   sub ValidManager {
       my $certificate = shift; 
   
       return isManager;
   }
   #
   #  CopyFile:  Called as part of the process of installing a 
   #             new configuration file.  This function copies an existing
   #             file to a backup file.
   # Parameters:
   #     oldfile  - Name of the file to backup.
   #     newfile  - Name of the backup file.
   # Return:
   #     0   - Failure (errno has failure reason).
   #     1   - Success.
   #
   sub CopyFile {
   
       my ($oldfile, $newfile) = @_;
   
       #  The file must exist:
   
       if(-e $oldfile) {
   
    # Read the old file.
   
    my $oldfh = IO::File->new("< $oldfile");
    if(!$oldfh) {
       return 0;
    }
    my @contents = <$oldfh>;  # Suck in the entire file.
   
    # write the backup file:
   
    my $newfh = IO::File->new("> $newfile");
    if(!(defined $newfh)){
       return 0;
    }
    my $lines = scalar @contents;
    for (my $i =0; $i < $lines; $i++) {
       print $newfh ($contents[$i]);
    }
   
    $oldfh->close;
    $newfh->close;
   
    chmod(0660, $newfile);
   
    return 1;
       
       } else {
    return 0;
       }
   }
   #
   #  Host files are passed out with externally visible host IPs.
   #  If, for example, we are behind a fire-wall or NAT host, our 
   #  internally visible IP may be different than the externally
   #  visible IP.  Therefore, we always adjust the contents of the
   #  host file so that the entry for ME is the IP that we believe
   #  we have.  At present, this is defined as the entry that
   #  DNS has for us.  If by some chance we are not able to get a
   #  DNS translation for us, then we assume that the host.tab file
   #  is correct.  
   #    BUGBUGBUG - in the future, we really should see if we can
   #       easily query the interface(s) instead.
   # Parameter(s):
   #     contents    - The contents of the host.tab to check.
   # Returns:
   #     newcontents - The adjusted contents.
   #
   #
   sub AdjustHostContents {
       my $contents  = shift;
       my $adjusted;
       my $me        = $perlvar{'lonHostID'};
   
    foreach my $line (split(/\n/,$contents)) {
    if(!(($line eq "") || ($line =~ /^ *\#/) || ($line =~ /^ *$/))) {
       chomp($line);
       my ($id,$domain,$role,$name,$ip,$maxcon,$idleto,$mincon)=split(/:/,$line);
       if ($id eq $me) {
             my $ip = gethostbyname($name);
             my $ipnew = inet_ntoa($ip);
            $ip = $ipnew;
    #  Reconstruct the host line and append to adjusted:
   
      my $newline = "$id:$domain:$role:$name:$ip";
      if($maxcon ne "") { # Not all hosts have loncnew tuning params
        $newline .= ":$maxcon:$idleto:$mincon";
      }
      $adjusted .= $newline."\n";
   
         } else { # Not me, pass unmodified.
      $adjusted .= $line."\n";
         }
    } else {                  # Blank or comment never re-written.
       $adjusted .= $line."\n"; # Pass blanks and comments as is.
    }
    }
    return $adjusted;
   }
   #
   #   InstallFile: Called to install an administrative file:
   #       - The file is created with <name>.tmp
   #       - The <name>.tmp file is then mv'd to <name>
   #   This lugubrious procedure is done to ensure that we are never without
   #   a valid, even if dated, version of the file regardless of who crashes
   #   and when the crash occurs.
   #
   #  Parameters:
   #       Name of the file
   #       File Contents.
   #  Return:
   #      nonzero - success.
   #      0       - failure and $! has an errno.
   #
   sub InstallFile {
   
       my ($Filename, $Contents) = @_;
       my $TempFile = $Filename.".tmp";
   
       #  Open the file for write:
   
       my $fh = IO::File->new("> $TempFile"); # Write to temp.
       if(!(defined $fh)) {
    &logthis('<font color="red"> Unable to create '.$TempFile."</font>");
    return 0;
       }
       #  write the contents of the file:
   
       print $fh ($Contents); 
       $fh->close; # In case we ever have a filesystem w. locking
   
       chmod(0660, $TempFile);
   
       # Now we can move install the file in position.
       
       move($TempFile, $Filename);
   
       return 1;
   }
   
   
   #
   #   ConfigFileFromSelector: converts a configuration file selector
   #                 (one of host or domain at this point) into a 
   #                 configuration file pathname.
   #
   #  Parameters:
   #      selector  - Configuration file selector.
   #  Returns:
   #      Full path to the file or undef if the selector is invalid.
   #
   sub ConfigFileFromSelector {
       my $selector   = shift;
       my $tablefile;
   
       my $tabledir = $perlvar{'lonTabDir'}.'/';
       if ($selector eq "hosts") {
    $tablefile = $tabledir."hosts.tab";
       } elsif ($selector eq "domain") {
    $tablefile = $tabledir."domain.tab";
       } else {
    return undef;
       }
       return $tablefile;
   
   }
   #
   #   PushFile:  Called to do an administrative push of a file.
   #              - Ensure the file being pushed is one we support.
   #              - Backup the old file to <filename.saved>
   #              - Separate the contents of the new file out from the
   #                rest of the request.
   #              - Write the new file.
   #  Parameter:
   #     Request - The entire user request.  This consists of a : separated
   #               string pushfile:tablename:contents.
   #     NOTE:  The contents may have :'s in it as well making things a bit
   #            more interesting... but not much.
   #  Returns:
   #     String to send to client ("ok" or "refused" if bad file).
   #
   sub PushFile {
       my $request = shift;    
       my ($command, $filename, $contents) = split(":", $request, 3);
       
       #  At this point in time, pushes for only the following tables are
       #  supported:
       #   hosts.tab  ($filename eq host).
       #   domain.tab ($filename eq domain).
       # Construct the destination filename or reject the request.
       #
       # lonManage is supposed to ensure this, however this session could be
       # part of some elaborate spoof that managed somehow to authenticate.
       #
   
   
       my $tablefile = ConfigFileFromSelector($filename);
       if(! (defined $tablefile)) {
    return "refused";
       }
       #
       # >copy< the old table to the backup table
       #        don't rename in case system crashes/reboots etc. in the time
       #        window between a rename and write.
       #
       my $backupfile = $tablefile;
       $backupfile    =~ s/\.tab$/.old/;
       if(!CopyFile($tablefile, $backupfile)) {
    &logthis('<font color="green"> CopyFile from '.$tablefile." to ".$backupfile." failed </font>");
    return "error:$!";
       }
       &logthis('<font color="green"> Pushfile: backed up '
       .$tablefile." to $backupfile</font>");
       
       #  If the file being pushed is the host file, we adjust the entry for ourself so that the
       #  IP will be our current IP as looked up in dns.  Note this is only 99% good as it's possible
       #  to conceive of conditions where we don't have a DNS entry locally.  This is possible in a 
       #  network sense but it doesn't make much sense in a LonCAPA sense so we ignore (for now)
       #  that possibilty.
   
       if($filename eq "host") {
    $contents = AdjustHostContents($contents);
       }
   
       #  Install the new file:
   
       if(!InstallFile($tablefile, $contents)) {
    &logthis('<font color="red"> Pushfile: unable to install '
    .$tablefile." $! </font>");
    return "error:$!";
       }
       else {
    &logthis('<font color="green"> Installed new '.$tablefile
    ."</font>");
   
       }
   
   
       #  Indicate success:
    
       return "ok";
   
   }
   
   #
   #  Called to re-init either lonc or lond.
   #
   #  Parameters:
   #    request   - The full request by the client.  This is of the form
   #                reinit:<process>  
   #                where <process> is allowed to be either of 
   #                lonc or lond
   #
   #  Returns:
   #     The string to be sent back to the client either:
   #   ok         - Everything worked just fine.
   #   error:why  - There was a failure and why describes the reason.
   #
   #
   sub ReinitProcess {
       my $request = shift;
   
   
       # separate the request (reinit) from the process identifier and
       # validate it producing the name of the .pid file for the process.
       #
       #
       my ($junk, $process) = split(":", $request);
       my $processpidfile = $perlvar{'lonDaemons'}.'/logs/';
       if($process eq 'lonc') {
    $processpidfile = $processpidfile."lonc.pid";
    if (!open(PIDFILE, "< $processpidfile")) {
       return "error:Open failed for $processpidfile";
    }
    my $loncpid = <PIDFILE>;
    close(PIDFILE);
    logthis('<font color="red"> Reinitializing lonc pid='.$loncpid
    ."</font>");
    kill("USR2", $loncpid);
       } elsif ($process eq 'lond') {
    logthis('<font color="red"> Reinitializing self (lond) </font>');
    &UpdateHosts; # Lond is us!!
       } else {
    &logthis('<font color="yellow" Invalid reinit request for '.$process
    ."</font>");
    return "error:Invalid process identifier $process";
       }
       return 'ok';
   }
   #   Validate a line in a configuration file edit script:
   #   Validation includes:
   #     - Ensuring the command is valid.
   #     - Ensuring the command has sufficient parameters
   #   Parameters:
   #     scriptline - A line to validate (\n has been stripped for what it's worth).
   #
   #   Return:
   #      0     - Invalid scriptline.
   #      1     - Valid scriptline
   #  NOTE:
   #     Only the command syntax is checked, not the executability of the
   #     command.
   #
   sub isValidEditCommand {
       my $scriptline = shift;
   
       #   Line elements are pipe separated:
   
       my ($command, $key, $newline)  = split(/\|/, $scriptline);
       &logthis('<font color="green"> isValideditCommand checking: '.
        "Command = '$command', Key = '$key', Newline = '$newline' </font>\n");
       
       if ($command eq "delete") {
    #
    #   key with no newline.
    #
    if( ($key eq "") || ($newline ne "")) {
       return 0; # Must have key but no newline.
    } else {
       return 1; # Valid syntax.
    }
       } elsif ($command eq "replace") {
    #
    #   key and newline:
    #
    if (($key eq "") || ($newline eq "")) {
       return 0;
    } else {
       return 1;
    }
       } elsif ($command eq "append") {
    if (($key ne "") && ($newline eq "")) {
       return 1;
    } else {
       return 0;
    }
       } else {
    return 0; # Invalid command.
       }
       return 0; # Should not get here!!!
   }
   #
   #   ApplyEdit - Applies an edit command to a line in a configuration 
   #               file.  It is the caller's responsiblity to validate the
   #               edit line.
   #   Parameters:
   #      $directive - A single edit directive to apply.  
   #                   Edit directives are of the form:
   #                  append|newline      - Appends a new line to the file.
   #                  replace|key|newline - Replaces the line with key value 'key'
   #                  delete|key          - Deletes the line with key value 'key'.
   #      $editor   - A config file editor object that contains the
   #                  file being edited.
   #
   sub ApplyEdit {
   
       my ($directive, $editor) = @_;
   
       # Break the directive down into its command and its parameters
       # (at most two at this point.  The meaning of the parameters, if in fact
       #  they exist depends on the command).
   
       my ($command, $p1, $p2) = split(/\|/, $directive);
   
       if($command eq "append") {
    $editor->Append($p1);          # p1 - key p2 null.
       } elsif ($command eq "replace") {
    $editor->ReplaceLine($p1, $p2);   # p1 - key p2 = newline.
       } elsif ($command eq "delete") {
    $editor->DeleteLine($p1);         # p1 - key p2 null.
       } else {          # Should not get here!!!
    die "Invalid command given to ApplyEdit $command"
       }
   }
   #
   # AdjustOurHost:
   #           Adjusts a host file stored in a configuration file editor object
   #           for the true IP address of this host. This is necessary for hosts
   #           that live behind a firewall.
   #           Those hosts have a publicly distributed IP of the firewall, but
   #           internally must use their actual IP.  We assume that a given
   #           host only has a single IP interface for now.
   # Formal Parameters:
   #     editor   - The configuration file editor to adjust.  This
   #                editor is assumed to contain a hosts.tab file.
   # Strategy:
   #    - Figure out our hostname.
   #    - Lookup the entry for this host.
   #    - Modify the line to contain our IP
   #    - Do a replace for this host.
   sub AdjustOurHost {
       my $editor        = shift;
   
       # figure out who I am.
   
       my $myHostName    = $perlvar{'lonHostID'}; # LonCAPA hostname.
   
       #  Get my host file entry.
   
       my $ConfigLine    = $editor->Find($myHostName);
       if(! (defined $ConfigLine)) {
    die "AdjustOurHost - no entry for me in hosts file $myHostName";
       }
       # figure out my IP:
       #   Use the config line to get my hostname.
       #   Use gethostbyname to translate that into an IP address.
       #
       my ($id,$domain,$role,$name,$ip,$maxcon,$idleto,$mincon) = split(/:/,$ConfigLine);
       my $BinaryIp = gethostbyname($name);
       my $ip       = inet_ntoa($ip);
       #
       #  Reassemble the config line from the elements in the list.
       #  Note that if the loncnew items were not present before, they will
       #  be now even if they would be empty
       #
       my $newConfigLine = $id;
       foreach my $item ($domain, $role, $name, $ip, $maxcon, $idleto, $mincon) {
    $newConfigLine .= ":".$item;
       }
       #  Replace the line:
   
       $editor->ReplaceLine($id, $newConfigLine);
       
   }
   #
   #   ReplaceConfigFile:
   #              Replaces a configuration file with the contents of a
   #              configuration file editor object.
   #              This is done by:
   #              - Copying the target file to <filename>.old
   #              - Writing the new file to <filename>.tmp
   #              - Moving <filename.tmp>  -> <filename>
   #              This laborious process ensures that the system is never without
   #              a configuration file that's at least valid (even if the contents
   #              may be dated).
   #   Parameters:
   #        filename   - Name of the file to modify... this is a full path.
   #        editor     - Editor containing the file.
   #
   sub ReplaceConfigFile {
       
       my ($filename, $editor) = @_;
   
       CopyFile ($filename, $filename.".old");
   
       my $contents  = $editor->Get(); # Get the contents of the file.
   
       InstallFile($filename, $contents);
   }
   #   
   #
   #   Called to edit a configuration table  file
   #   Parameters:
   #      request           - The entire command/request sent by lonc or lonManage
   #   Return:
   #      The reply to send to the client.
   #
   sub EditFile {
       my $request = shift;
   
       #  Split the command into it's pieces:  edit:filetype:script
   
       my ($request, $filetype, $script) = split(/:/, $request,3); # : in script
   
       #  Check the pre-coditions for success:
   
       if($request != "edit") { # Something is amiss afoot alack.
    return "error:edit request detected, but request != 'edit'\n";
       }
       if( ($filetype ne "hosts")  &&
    ($filetype ne "domain")) {
    return "error:edit requested with invalid file specifier: $filetype \n";
       }
   
       #   Split the edit script and check it's validity.
   
       my @scriptlines = split(/\n/, $script);  # one line per element.
       my $linecount   = scalar(@scriptlines);
       for(my $i = 0; $i < $linecount; $i++) {
    chomp($scriptlines[$i]);
    if(!isValidEditCommand($scriptlines[$i])) {
       return "error:edit with bad script line: '$scriptlines[$i]' \n";
    }
       }
   
       #   Execute the edit operation.
       #   - Create a config file editor for the appropriate file and 
       #   - execute each command in the script:
       #
       my $configfile = ConfigFileFromSelector($filetype);
       if (!(defined $configfile)) {
    return "refused\n";
       }
       my $editor = ConfigFileEdit->new($configfile);
   
       for (my $i = 0; $i < $linecount; $i++) {
    ApplyEdit($scriptlines[$i], $editor);
       }
       # If the file is the host file, ensure that our host is
       # adjusted to have our ip:
       #
       if($filetype eq "host") {
    AdjustOurHost($editor);
       }
       #  Finally replace the current file with our file.
       #
       ReplaceConfigFile($configfile, $editor);
   
       return "ok\n";
   }
   #
   #  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];
       }
   }
   
   #
   # 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  # grabs exception and records it to log before exiting
 sub catchexception {  sub catchexception {
     my ($error)=@_;      my ($error)=@_;
     $SIG{'QUIT'}='DEFAULT';      $SIG{'QUIT'}='DEFAULT';
     $SIG{__DIE__}='DEFAULT';      $SIG{__DIE__}='DEFAULT';
     &logthis("<font color=red>CRITICAL: "      &status("Catching exception");
      ."ABNORMAL EXIT. Child $$ for server $wasserver died through "      &logthis("<font color='red'>CRITICAL: "
        ."ABNORMAL EXIT. Child $$ for server $thisserver died through "
      ."a crash with this error msg->[$error]</font>");       ."a crash with this error msg->[$error]</font>");
       &logthis('Famous last words: '.$status.' - '.$lastlog);
     if ($client) { print $client "error: $error\n"; }      if ($client) { print $client "error: $error\n"; }
       $server->close();
     die($error);      die($error);
 }  }
   
   sub timeout {
       &status("Handling Timeout");
       &logthis("<font color='red'>CRITICAL: TIME OUT ".$$."</font>");
       &catchexception('Timeout');
   }
 # -------------------------------- Set signal handlers to record abnormal exits  # -------------------------------- Set signal handlers to record abnormal exits
   
 $SIG{'QUIT'}=\&catchexception;  $SIG{'QUIT'}=\&catchexception;
 $SIG{__DIE__}=\&catchexception;  $SIG{__DIE__}=\&catchexception;
   
 # ------------------------------------ Read httpd access.conf and get variables  # ---------------------------------- Read loncapa_apache.conf and loncapa.conf
   &status("Read loncapa.conf and loncapa_apache.conf");
 open (CONFIG,"/etc/httpd/conf/access.conf") || die "Can't read access.conf";  my $perlvarref=LONCAPA::Configuration::read_conf('loncapa.conf');
   %perlvar=%{$perlvarref};
 while ($configline=<CONFIG>) {  undef $perlvarref;
     if ($configline =~ /PerlSetVar/) {  
  my ($dummy,$varname,$varvalue)=split(/\s+/,$configline);  
         chomp($varvalue);  
         $perlvar{$varname}=$varvalue;  
     }  
 }  
 close(CONFIG);  
   
 # ----------------------------- Make sure this process is running from user=www  # ----------------------------- Make sure this process is running from user=www
 my $wwwid=getpwnam('www');  my $wwwid=getpwnam('www');
 if ($wwwid!=$<) {  if ($wwwid!=$<) {
    $emailto="$perlvar{'lonAdmEMail'},$perlvar{'lonSysEMail'}";     my $emailto="$perlvar{'lonAdmEMail'},$perlvar{'lonSysEMail'}";
    $subj="LON: $perlvar{'lonHostID'} User ID mismatch";     my $subj="LON: $currenthostid User ID mismatch";
    system("echo 'User ID mismatch.  lond must be run as user www.' |\     system("echo 'User ID mismatch.  lond must be run as user www.' |\
  mailto $emailto -s '$subj' > /dev/null");   mailto $emailto -s '$subj' > /dev/null");
    exit 1;     exit 1;
Line 82  if (-e $pidfile) { Line 976  if (-e $pidfile) {
    if (kill 0 => $pide) { die "already running"; }     if (kill 0 => $pide) { die "already running"; }
 }  }
   
 $PREFORK=4; # number of children to maintain, at least four spare  
   
 # ------------------------------------------------------------- Read hosts file  # ------------------------------------------------------------- Read hosts 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);  
     $hostid{$ip}=$id;  
     if ($id eq $perlvar{'lonHostID'}) { $thisserver=$name; }  
     $PREFORK++;  
 }  
 close(CONFIG);  
   
 # establish SERVER socket, bind and listen.  # establish SERVER socket, bind and listen.
 $server = IO::Socket::INET->new(LocalPort => $perlvar{'londPort'},  $server = IO::Socket::INET->new(LocalPort => $perlvar{'londPort'},
Line 109  $server = IO::Socket::INET->new(LocalPor Line 992  $server = IO::Socket::INET->new(LocalPor
   
 # global variables  # global variables
   
 $MAX_CLIENTS_PER_CHILD  = 5;        # number of clients each child should   my %children               = ();       # keys are current child process IDs
                                     # process  
 %children               = ();       # keys are current child process IDs  
 $children               = 0;        # current number of children  
   
 sub REAPER {                        # takes care of dead children  sub REAPER {                        # takes care of dead children
     $SIG{CHLD} = \&REAPER;      $SIG{CHLD} = \&REAPER;
     my $pid = wait;      &status("Handling child death");
     $children --;      my $pid;
     &logthis("Child $pid died");      do {
     delete $children{$pid};   $pid = waitpid(-1,&WNOHANG());
    if (defined($children{$pid})) {
       &logthis("Child $pid died");
       delete($children{$pid});
    } elsif ($pid > 0) {
       &logthis("Unknown Child $pid died");
    }
       } while ( $pid > 0 );
       foreach my $child (keys(%children)) {
    $pid = waitpid($child,&WNOHANG());
    if ($pid > 0) {
       &logthis("Child $child - $pid looks like we missed it's death");
       delete($children{$pid});
    }
       }
       &status("Finished Handling child death");
 }  }
   
 sub HUNTSMAN {                      # signal handler for SIGINT  sub HUNTSMAN {                      # signal handler for SIGINT
       &status("Killing children (INT)");
     local($SIG{CHLD}) = 'IGNORE';   # we're going to kill our children      local($SIG{CHLD}) = 'IGNORE';   # we're going to kill our children
     kill 'INT' => keys %children;      kill 'INT' => keys %children;
       &logthis("Free socket: ".shutdown($server,2)); # free up socket
     my $execdir=$perlvar{'lonDaemons'};      my $execdir=$perlvar{'lonDaemons'};
     unlink("$execdir/logs/lond.pid");      unlink("$execdir/logs/lond.pid");
     &logthis("<font color=red>CRITICAL: Shutting down</font>");      &logthis("<font color='red'>CRITICAL: Shutting down</font>");
       &status("Done killing children");
     exit;                           # clean up with dignity      exit;                           # clean up with dignity
 }  }
   
 sub HUPSMAN {                      # signal handler for SIGHUP  sub HUPSMAN {                      # signal handler for SIGHUP
     local($SIG{CHLD}) = 'IGNORE';  # we're going to kill our children      local($SIG{CHLD}) = 'IGNORE';  # we're going to kill our children
       &status("Killing children for restart (HUP)");
     kill 'INT' => keys %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>");      &logthis("<font color='red'>CRITICAL: Restarting</font>");
     unlink("$execdir/logs/lond.pid");  
     my $execdir=$perlvar{'lonDaemons'};      my $execdir=$perlvar{'lonDaemons'};
       unlink("$execdir/logs/lond.pid");
       &status("Restarting self (HUP)");
     exec("$execdir/lond");         # here we go again      exec("$execdir/lond");         # here we go again
 }  }
   
   #
   #    Kill off hashes that describe the host table prior to re-reading it.
   #    Hashes affected are:
   #       %hostid, %hostdom %hostip %hostdns.
   #
   sub KillHostHashes {
       foreach my $key (keys %hostid) {
    delete $hostid{$key};
       }
       foreach my $key (keys %hostdom) {
    delete $hostdom{$key};
       }
       foreach my $key (keys %hostip) {
    delete $hostip{$key};
       }
       foreach my $key (keys %hostdns) {
    delete $hostdns{$key};
       }
   }
   #
   #   Read in the host table from file and distribute it into the various hashes:
   #
   #    - %hostid  -  Indexed by IP, the loncapa hostname.
   #    - %hostdom -  Indexed by  loncapa hostname, the domain.
   #    - %hostip  -  Indexed by hostid, the Ip address of the host.
   sub ReadHostTable {
   
       open (CONFIG,"$perlvar{'lonTabDir'}/hosts.tab") || die "Can't read host file";
       my $myloncapaname = $perlvar{'lonHostID'};
       Debug("My loncapa name is : $myloncapaname");
       while (my $configline=<CONFIG>) {
    if (!($configline =~ /^\s*\#/)) {
       my ($id,$domain,$role,$name,$ip)=split(/:/,$configline);
       chomp($ip); $ip=~s/\D+$//;
       $hostid{$ip}=$id;         # LonCAPA name of host by IP.
       $hostdom{$id}=$domain;    # LonCAPA domain name of host. 
       $hostip{$id}=$ip;      # IP address of host.
       $hostdns{$name} = $id;    # LonCAPA name of host by DNS.
   
       if ($id eq $perlvar{'lonHostID'}) { 
    Debug("Found me in the host table: $name");
    $thisserver=$name; 
       }
    }
       }
       close(CONFIG);
   }
   #
   #  Reload the Apache daemon's state.
   #  This is done by invoking /home/httpd/perl/apachereload
   #  a setuid perl script that can be root for us to do this job.
   #
   sub ReloadApache {
       my $execdir = $perlvar{'lonDaemons'};
       my $script  = $execdir."/apachereload";
       system($script);
   }
   
   #
   #   Called in response to a USR2 signal.
   #   - Reread hosts.tab
   #   - All children connected to hosts that were removed from hosts.tab
   #     are killed via SIGINT
   #   - All children connected to previously existing hosts are sent SIGUSR1
   #   - Our internal hosts hash is updated to reflect the new contents of
   #     hosts.tab causing connections from hosts added to hosts.tab to
   #     now be honored.
   #
   sub UpdateHosts {
       &status("Reload hosts.tab");
       logthis('<font color="blue"> Updating connections </font>');
       #
       #  The %children hash has the set of IP's we currently have children
       #  on.  These need to be matched against records in the hosts.tab
       #  Any ip's no longer in the table get killed off they correspond to
       #  either dropped or changed hosts.  Note that the re-read of the table
       #  will take care of new and changed hosts as connections come into being.
   
   
       KillHostHashes;
       ReadHostTable;
   
       foreach my $child (keys %children) {
    my $childip = $children{$child};
    if(!$hostid{$childip}) {
       logthis('<font color="blue"> UpdateHosts killing child '
       ." $child for ip $childip </font>");
       kill('INT', $child);
    } else {
       logthis('<font color="green"> keeping child for ip '
       ." $childip (pid=$child) </font>");
    }
       }
       ReloadApache;
       &status("Finished reloading hosts.tab");
   }
   
   
   sub checkchildren {
       &status("Checking on the children (sending signals)");
       &initnewstatus();
       &logstatus();
       &logthis('Going to check on the children');
       my $docdir=$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" };
       $SIG{__DIE__} = 'DEFAULT';
       &status("Checking on the children (waiting for reports)");
       foreach (sort keys %children) {
           unless (-e "$docdir/lon-status/londchld/$_.txt") {
             eval {
               alarm(300);
       &logthis('Child '.$_.' did not respond');
       kill 9 => $_;
       #$emailto="$perlvar{'lonAdmEMail'},$perlvar{'lonSysEMail'}";
       #$subj="LON: $currenthostid 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__} = \&catchexception;
       &status("Finished checking children");
   }
   
 # --------------------------------------------------------------------- Logging  # --------------------------------------------------------------------- Logging
   
 sub logthis {  sub logthis {
Line 149  sub logthis { Line 1184  sub logthis {
     my $fh=IO::File->new(">>$execdir/logs/lond.log");      my $fh=IO::File->new(">>$execdir/logs/lond.log");
     my $now=time;      my $now=time;
     my $local=localtime($now);      my $local=localtime($now);
       $lastlog=$local.': '.$message;
     print $fh "$local ($$): $message\n";      print $fh "$local ($$): $message\n";
 }  }
   
   # ------------------------- Conditional log if $DEBUG true.
   sub Debug {
       my $message = shift;
       if($DEBUG) {
    &logthis($message);
       }
   }
   
   #
   #   Sub to do replies to client.. this gives a hook for some
   #   debug tracing too:
   #  Parameters:
   #     fd      - File open on client.
   #     reply   - Text to send to client.
   #     request - Original request from client.
   #
   sub Reply {
   
       my ($fd, $reply, $request) = @_;
   
       print $fd $reply;
       Debug("Request was $request  Reply was $reply");
   
   }
   # ------------------------------------------------------------------ Log status
   
   sub logstatus {
       &status("Doing logging");
       my $docdir=$perlvar{'lonDocRoot'};
       {
       my $fh=IO::File->new(">>$docdir/lon-status/londstatus.txt");
       print $fh $$."\t".$clientname."\t".$currenthostid."\t"
    .$status."\t".$lastlog."\t $keymode\n";
       $fh->close();
       }
       &status("Finished londstatus.txt");
       {
    my $fh=IO::File->new(">$docdir/lon-status/londchld/$$.txt");
           print $fh $status."\n".$lastlog."\n".time."\n$keymode";
           $fh->close();
       }
       &status("Finished logging");
   }
   
   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 (my $filename=readdir(DIR)) {
           unlink("$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  # -------------------------------------------------------- Escape Special Chars
   
Line 181  sub reconlonc { Line 1283  sub reconlonc {
         if (kill 0 => $loncpid) {          if (kill 0 => $loncpid) {
     &logthis("lonc at pid $loncpid responding, sending USR1");      &logthis("lonc at pid $loncpid responding, sending USR1");
             kill USR1 => $loncpid;              kill USR1 => $loncpid;
             sleep 1;  
             if (-e "$peerfile") { return; }  
             &logthis("$peerfile still not there, give it another try");  
             sleep 5;  
             if (-e "$peerfile") { return; }  
             &logthis(  
  "<font color=blue>WARNING: $peerfile still not there, giving up</font>");  
         } else {          } else {
     &logthis(      &logthis(
               "<font color=red>CRITICAL: "                "<font color='red'>CRITICAL: "
              ."lonc at pid $loncpid not responding, giving up</font>");               ."lonc at pid $loncpid not responding, giving up</font>");
         }          }
     } else {      } else {
       &logthis('<font color=red>CRITICAL: lonc not running, giving up</font>');        &logthis('<font color="red">CRITICAL: lonc not running, giving up</font>');
     }      }
 }  }
   
Line 217  sub subreply { Line 1312  sub subreply {
 sub reply {  sub reply {
   my ($cmd,$server)=@_;    my ($cmd,$server)=@_;
   my $answer;    my $answer;
   if ($server ne $perlvar{'lonHostID'}) {     if ($server ne $currenthostid) { 
     $answer=subreply($cmd,$server);      $answer=subreply($cmd,$server);
     if ($answer eq 'con_lost') {      if ($answer eq 'con_lost') {
  $answer=subreply("ping",$server);   $answer=subreply("ping",$server);
         if ($answer ne $server) {          if ($answer ne $server) {
       &logthis("sub reply: answer != server answer is $answer, server is $server");
            &reconlonc("$perlvar{'lonSockDir'}/$server");             &reconlonc("$perlvar{'lonSockDir'}/$server");
         }          }
         $answer=subreply($cmd,$server);          $answer=subreply($cmd,$server);
Line 285  sub ishome { Line 1381  sub ishome {
 # ======================================================= Continue main program  # ======================================================= Continue main program
 # ---------------------------------------------------- Fork once and dissociate  # ---------------------------------------------------- Fork once and dissociate
   
 $fpid=fork;  my $fpid=fork;
 exit if $fpid;  exit if $fpid;
 die "Couldn't fork: $!" unless defined ($fpid);  die "Couldn't fork: $!" unless defined ($fpid);
   
Line 293  POSIX::setsid() or die "Can't start new Line 1389  POSIX::setsid() or die "Can't start new
   
 # ------------------------------------------------------- Write our PID on disk  # ------------------------------------------------------- Write our PID on disk
   
 $execdir=$perlvar{'lonDaemons'};  my $execdir=$perlvar{'lonDaemons'};
 open (PIDSAVE,">$execdir/logs/lond.pid");  open (PIDSAVE,">$execdir/logs/lond.pid");
 print PIDSAVE "$$\n";  print PIDSAVE "$$\n";
 close(PIDSAVE);  close(PIDSAVE);
 &logthis("<font color=red>CRITICAL: ---------- Starting ----------</font>");  &logthis("<font color='red'>CRITICAL: ---------- Starting ----------</font>");
   &status('Starting');
   
   
 # ------------------------------------------------------- Now we are on our own  
       
 # Fork off our children.  
 for (1 .. $PREFORK) {  
     make_new_child();  
 }  
   
 # ----------------------------------------------------- Install signal handlers  # ----------------------------------------------------- Install signal handlers
   
   
 $SIG{CHLD} = \&REAPER;  $SIG{CHLD} = \&REAPER;
 $SIG{INT}  = $SIG{TERM} = \&HUNTSMAN;  $SIG{INT}  = $SIG{TERM} = \&HUNTSMAN;
 $SIG{HUP}  = \&HUPSMAN;  $SIG{HUP}  = \&HUPSMAN;
   $SIG{USR1} = \&checkchildren;
   $SIG{USR2} = \&UpdateHosts;
   
   #  Read the host hashes:
   
   ReadHostTable;
   
   # --------------------------------------------------------------
   #   Accept connections.  When a connection comes in, it is validated
   #   and if good, a child process is created to process transactions
   #   along the connection.
   
 # And maintain the population.  
 while (1) {  while (1) {
     sleep;                          # wait for a signal (i.e., child's death)      &status('Starting accept');
     for ($i = $children; $i < $PREFORK; $i++) {      $client = $server->accept() or next;
         make_new_child();           # top up the child pool      &status('Accepted '.$client.' off to spawn');
     }      make_new_child($client);
       &status('Finished spawning');
 }  }
   
 sub make_new_child {  sub make_new_child {
     my $pid;      my $pid;
     my $cipher;      my $cipher;
     my $sigset;      my $sigset;
     &logthis("Attempting to start child");      
       $client = shift;
       &status('Starting new child '.$client);
       &logthis('<font color="green"> Attempting to start child ('.$client.
        ")</font>");    
     # block signal for fork      # block signal for fork
     $sigset = POSIX::SigSet->new(SIGINT);      $sigset = POSIX::SigSet->new(SIGINT);
     sigprocmask(SIG_BLOCK, $sigset)      sigprocmask(SIG_BLOCK, $sigset)
         or die "Can't block SIGINT for fork: $!\n";          or die "Can't block SIGINT for fork: $!\n";
       
     die "fork: $!" unless defined ($pid = fork);      die "fork: $!" unless defined ($pid = fork);
   
       $client->sockopt(SO_KEEPALIVE, 1); # Enable monitoring of
                                  # connection liveness.
   
       #
       #  Figure out who we're talking to so we can record the peer in 
       #  the pid hash.
       #
       my $caller = getpeername($client);
       my ($port,$iaddr);
       if (defined($caller) && length($caller) > 0) {
    ($port,$iaddr)=unpack_sockaddr_in($caller);
       } else {
    &logthis("Unable to determine who caller was, getpeername returned nothing");
       }
       if (defined($iaddr)) {
    $clientip  = inet_ntoa($iaddr);
    Debug("Connected with $clientip");
    $clientdns = gethostbyaddr($iaddr, AF_INET);
    Debug("Connected with $clientdns by name");
       } else {
    &logthis("Unable to determine clientip");
    $clientip='Unavailable';
       }
           
     if ($pid) {      if ($pid) {
         # Parent records the child's birth and returns.          # Parent records the child's birth and returns.
         sigprocmask(SIG_UNBLOCK, $sigset)          sigprocmask(SIG_UNBLOCK, $sigset)
             or die "Can't unblock SIGINT for fork: $!\n";              or die "Can't unblock SIGINT for fork: $!\n";
         $children{$pid} = 1;          $children{$pid} = $clientip;
         $children++;          &status('Started child '.$pid);
         return;          return;
     } else {      } else {
         # Child can *not* return from this subroutine.          # Child can *not* return from this subroutine.
         $SIG{INT} = 'DEFAULT';      # make SIGINT kill us as it did before          $SIG{INT} = 'DEFAULT';      # make SIGINT kill us as it did before
               $SIG{CHLD} = 'DEFAULT'; #make this default so that pwauth returns 
                                   #don't get intercepted
           $SIG{USR1}= \&logstatus;
           $SIG{ALRM}= \&timeout;
           $lastlog='Forked ';
           $status='Forked';
   
         # unblock signals          # unblock signals
         sigprocmask(SIG_UNBLOCK, $sigset)          sigprocmask(SIG_UNBLOCK, $sigset)
             or die "Can't unblock SIGINT for fork: $!\n";              or die "Can't unblock SIGINT for fork: $!\n";
   
         $tmpsnum=0;          my $tmpsnum=0;
       #---------------------------------------------------- kerberos 5 initialization
         # handle connections until we've reached $MAX_CLIENTS_PER_CHILD          &Authen::Krb5::init_context();
         for ($i=0; $i < $MAX_CLIENTS_PER_CHILD; $i++) {          &Authen::Krb5::init_ets();
             $client = $server->accept()     or last;  
   
    &status('Accepted connection');
 # =============================================================================  # =============================================================================
             # do something with the connection              # do something with the connection
 # -----------------------------------------------------------------------------  # -----------------------------------------------------------------------------
             # see if we know client and check for spoof IP by challenge   # see if we know client and 'check' for spoof IP by ineffective challenge
             my $caller=getpeername($client);  
             my ($port,$iaddr)=unpack_sockaddr_in($caller);   ReadManagerTable; # May also be a manager!!
             my $clientip=inet_ntoa($iaddr);  
             my $clientrec=($hostid{$clientip} ne undef);   my $clientrec=($hostid{$clientip}     ne undef);
             &logthis(   my $ismanager=($managers{$clientip}    ne undef);
 "<font color=yellow>INFO: Connect from $clientip ($hostid{$clientip})</font>");   $clientname  = "[unknonwn]";
             my $clientok;   if($clientrec) { # Establish client type.
             if ($clientrec) {      $ConnectionType = "client";
       my $remotereq=<$client>;      $clientname = $hostid{$clientip};
               $remotereq=~s/\W//g;      if($ismanager) {
               if ($remotereq eq 'init') {   $ConnectionType = "both";
   my $challenge="$$".time;      }
                   print $client "$challenge\n";   } else {
                   $remotereq=<$client>;      $ConnectionType = "manager";
                   $remotereq=~s/\W//g;      $clientname = $managers{$clientip};
                   if ($challenge eq $remotereq) {   }
       $clientok=1;   my $clientok;
                       print $client "ok\n";  
                   } else {   if ($clientrec || $ismanager) {
       &logthis(      &status("Waiting for init from $clientip $clientname");
  "<font color=blue>WARNING: $clientip did not reply challenge</font>");      &logthis('<font color="yellow">INFO: Connection, '.
                       print $client "bye\n";       $clientip.
                   }    " ($clientname) connection type = $ConnectionType </font>" );
               } else {      &status("Connecting $clientip  ($clientname))"); 
   &logthis(      my $remotereq=<$client>;
                     "<font color=blue>WARNING: "      chomp($remotereq);
                    ."$clientip failed to initialize: >$remotereq< </font>");      Debug("Got init: $remotereq");
   print $client "bye\n";      my $inikeyword = split(/:/, $remotereq);
               }      if ($remotereq =~ /^init/) {
    &sethost("sethost:$perlvar{'lonHostID'}");
    #
    #  If the remote is attempting a local init... give that a try:
    #
    my ($i, $inittype) = split(/:/, $remotereq);
   
    # If the connection type is ssl, but I didn't get my
    # certificate files yet, then I'll drop  back to 
    # insecure (if allowed).
   
    if($inittype eq "ssl") {
       my ($ca, $cert) = lonssl::CertificateFile;
       my $kfile       = lonssl::KeyFile;
       if((!$ca)   || 
          (!$cert) || 
          (!$kfile)) {
    $inittype = ""; # This forces insecure attempt.
    &logthis("<font color=\"blue\"> Certificates not "
    ."installed -- trying insecure auth</font>");
       }
       else { # SSL certificates are in place so
       } # Leave the inittype alone.
    }
   
    if($inittype eq "local") {
       my $key = LocalConnection($client, $remotereq);
       if($key) {
    Debug("Got local key $key");
    $clientok     = 1;
    my $cipherkey = pack("H32", $key);
    $cipher       = new IDEA($cipherkey);
    print $client "ok:local\n";
    &logthis('<font color="green"'
    . "Successful local authentication </font>");
    $keymode = "local"
       } else {
    Debug("Failed to get local key");
    $clientok = 0;
    shutdown($client, 3);
    close $client;
       }
    } elsif ($inittype eq "ssl") {
       my $key = SSLConnection($client);
       if ($key) {
    $clientok = 1;
    my $cipherkey = pack("H32", $key);
    $cipher       = new IDEA($cipherkey);
    &logthis('<font color="green">'
    ."Successfull ssl authentication with $clientname </font>");
    $keymode = "ssl";
        
       } else {
    $clientok = 0;
    close $client;
       }
      
    } else {
       my $ok = InsecureConnection($client);
       if($ok) {
    $clientok = 1;
    &logthis('<font color="green">'
    ."Successful insecure authentication with $clientname </font>");
    print $client "ok\n";
    $keymode = "insecure";
       } else {
    &logthis('<font color="yellow">'
     ."Attempted insecure connection disallowed </font>");
    close $client;
    $clientok = 0;
   
       }
    }
     } else {      } else {
               &logthis(   &logthis(
  "<font color=blue>WARNING: Unknown client $clientip</font>");   "<font color='blue'>WARNING: "
               print $client "bye\n";   ."$clientip failed to initialize: >$remotereq< </font>");
             }   &status('No init '.$clientip);
             if ($clientok) {      }
       
    } else {
       &logthis(
        "<font color='blue'>WARNING: Unknown client $clientip</font>");
       &status('Hung up on '.$clientip);
    }
    
    if ($clientok) {
 # ---------------- New known client connecting, could mean machine online again  # ---------------- New known client connecting, could mean machine online again
       &reconlonc("$perlvar{'lonSockDir'}/$hostid{$clientip}");      
               &logthis(      foreach my $id (keys(%hostip)) {
        "<font color=green>Established connection: $hostid{$clientip}</font>");   if ($hostip{$id} ne $clientip ||
       $hostip{$currenthostid} eq $clientip) {
       # no need to try to do recon's to myself
       next;
    }
    &reconlonc("$perlvar{'lonSockDir'}/$id");
       }
       &logthis("<font color='green'>Established connection: $clientname</font>");
       &status('Will listen to '.$clientname);
 # ------------------------------------------------------------ Process requests  # ------------------------------------------------------------ Process requests
               while (my $userinput=<$client>) {      while (my $userinput=<$client>) {
                 chomp($userinput);                  chomp($userinput);
    Debug("Request = $userinput\n");
                   &status('Processing '.$clientname.': '.$userinput);
                 my $wasenc=0;                  my $wasenc=0;
                   alarm(120);
 # ------------------------------------------------------------ See if encrypted  # ------------------------------------------------------------ See if encrypted
  if ($userinput =~ /^enc/) {   if ($userinput =~ /^enc/) {
   if ($cipher) {      if ($cipher) {
                     my ($cmd,$cmdlength,$encinput)=split(/:/,$userinput);   my ($cmd,$cmdlength,$encinput)=split(/:/,$userinput);
     $userinput='';   $userinput='';
                     for (my $encidx=0;$encidx<length($encinput);$encidx+=16) {   for (my $encidx=0;$encidx<length($encinput);$encidx+=16) {
                        $userinput.=      $userinput.=
    $cipher->decrypt(   $cipher->decrypt(
                             pack("H16",substr($encinput,$encidx,16))   pack("H16",substr($encinput,$encidx,16))
                            );   );
     }   }
     $userinput=substr($userinput,0,$cmdlength);   $userinput=substr($userinput,0,$cmdlength);
                     $wasenc=1;   $wasenc=1;
   }      }
  }   }
   
 # ------------------------------------------------------------- Normal commands  # ------------------------------------------------------------- Normal commands
 # ------------------------------------------------------------------------ ping  # ------------------------------------------------------------------------ ping
    if ($userinput =~ /^ping/) {   if ($userinput =~ /^ping/) { # client only
                        print $client "$perlvar{'lonHostID'}\n";      if(isClient) {
    print $client "$currenthostid\n";
       } else {
    Reply($client, "refused\n", $userinput);
       }
 # ------------------------------------------------------------------------ pong  # ------------------------------------------------------------------------ pong
    } elsif ($userinput =~ /^pong/) {   }elsif ($userinput =~ /^pong/) { # client only
                        $reply=reply("ping",$hostid{$clientip});      if(isClient) {
                        print $client "$perlvar{'lonHostID'}:$reply\n";    my $reply=&reply("ping",$clientname);
    print $client "$currenthostid:$reply\n"; 
       } else {
    Reply($client, "refused\n", $userinput);
       }
 # ------------------------------------------------------------------------ ekey  # ------------------------------------------------------------------------ ekey
    } elsif ($userinput =~ /^ekey/) {   } elsif ($userinput =~ /^ekey/) { # ok for both clients & mgrs
                        my $buildkey=time.$$.int(rand 100000);      my $buildkey=time.$$.int(rand 100000);
                        $buildkey=~tr/1-6/A-F/;      $buildkey=~tr/1-6/A-F/;
                        $buildkey=int(rand 100000).$buildkey.int(rand 100000);      $buildkey=int(rand 100000).$buildkey.int(rand 100000);
                        my $key=$perlvar{'lonHostID'}.$hostid{$clientip};      my $key=$currenthostid.$clientname;
                        $key=~tr/a-z/A-Z/;      $key=~tr/a-z/A-Z/;
                        $key=~tr/G-P/0-9/;      $key=~tr/G-P/0-9/;
                        $key=~tr/Q-Z/0-9/;      $key=~tr/Q-Z/0-9/;
                        $key=$key.$buildkey.$key.$buildkey.$key.$buildkey;      $key=$key.$buildkey.$key.$buildkey.$key.$buildkey;
                        $key=substr($key,0,32);      $key=substr($key,0,32);
                        my $cipherkey=pack("H32",$key);      my $cipherkey=pack("H32",$key);
                        $cipher=new IDEA $cipherkey;      $cipher=new IDEA $cipherkey;
                        print $client "$buildkey\n";       print $client "$buildkey\n"; 
 # ------------------------------------------------------------------------ load  # ------------------------------------------------------------------------ load
    } elsif ($userinput =~ /^load/) {   } elsif ($userinput =~ /^load/) { # client only
                        my $loadavg;      if (isClient) {
                        {   my $loadavg;
                           my $loadfile=IO::File->new('/proc/loadavg');   {
                           $loadavg=<$loadfile>;      my $loadfile=IO::File->new('/proc/loadavg');
                        }      $loadavg=<$loadfile>;
                        $loadavg =~ s/\s.*//g;   }
                        my $loadpercent=100*$loadavg/$perlvar{'lonLoadLim'};   $loadavg =~ s/\s.*//g;
        print $client "$loadpercent\n";   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:
   #
   # ----------------------------------------------------------------- currentauth
    } elsif ($userinput =~ /^currentauth/) {
       if (($wasenc==1)  && isClient) { # Encoded & client only.
    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 {
    Reply($client, "refused\n", $userinput);
   
       }
   #--------------------------------------------------------------------- pushfile
    } elsif($userinput =~ /^pushfile/) { # encoded & manager.
       if(($wasenc == 1) && isManager) {
    my $cert = GetCertificate($userinput);
    if(ValidManager($cert)) {
       my $reply = PushFile($userinput);
       print $client "$reply\n";
    } else {
       print $client "refused\n";
    } 
       } else {
    Reply($client, "refused\n", $userinput);
   
       }
   #--------------------------------------------------------------------- reinit
    } elsif($userinput =~ /^reinit/) { # Encoded and manager
    if (($wasenc == 1) && isManager) {
    my $cert = GetCertificate($userinput);
    if(ValidManager($cert)) {
    chomp($userinput);
    my $reply = ReinitProcess($userinput);
    print $client  "$reply\n";
    } else {
    print $client "refused\n";
    }
    } else {
    Reply($client, "refused\n", $userinput);
    }
   #------------------------------------------------------------------------- edit
       } elsif ($userinput =~ /^edit/) {    # encoded and manager:
    if(($wasenc ==1) && (isManager)) {
       my $cert = GetCertificate($userinput);
       if(ValidManager($cert)) {
                  my($command, $filetype, $script) = split(/:/, $userinput);
                  if (($filetype eq "hosts") || ($filetype eq "domain")) {
                     if($script ne "") {
         Reply($client, EditFile($userinput));
                     } else {
                        Reply($client,"refused\n",$userinput);
                     }
                  } else {
                     Reply($client,"refused\n",$userinput);
                  }
               } else {
                  Reply($client,"refused\n",$userinput);
               }
            } else {
        Reply($client,"refused\n",$userinput);
    }
 # ------------------------------------------------------------------------ auth  # ------------------------------------------------------------------------ auth
                    } elsif ($userinput =~ /^auth/) {      } elsif ($userinput =~ /^auth/) { # Encoded and client only.
      if ($wasenc==1) {      if (($wasenc==1) && isClient) {
                        my ($cmd,$udom,$uname,$upass)=split(/:/,$userinput);   my ($cmd,$udom,$uname,$upass)=split(/:/,$userinput);
                        chomp($upass);   chomp($upass);
                        $upass=unescape($upass);   $upass=unescape($upass);
                        my $proname=propath($udom,$uname);   my $proname=propath($udom,$uname);
                        my $passfilename="$proname/passwd";   my $passfilename="$proname/passwd";
                        if (-e $passfilename) {   if (-e $passfilename) {
                           my $pf = IO::File->new($passfilename);      my $pf = IO::File->new($passfilename);
                           my $realpasswd=<$pf>;      my $realpasswd=<$pf>;
                           chomp($realpasswd);      chomp($realpasswd);
                           my ($howpwd,$contentpwd)=split(/:/,$realpasswd);      my ($howpwd,$contentpwd)=split(/:/,$realpasswd);
                           my $pwdcorrect=0;      my $pwdcorrect=0;
                           if ($howpwd eq 'internal') {      if ($howpwd eq 'internal') {
       $pwdcorrect=   &Debug("Internal auth");
   (crypt($upass,$contentpwd) eq $contentpwd);   $pwdcorrect=
                           } elsif ($howpwd eq 'unix') {      (crypt($upass,$contentpwd) eq $contentpwd);
                               $contentpwd=(getpwnam($uname))[1];      } elsif ($howpwd eq 'unix') {
                               $pwdcorrect=   &Debug("Unix auth");
                                   (crypt($upass,$contentpwd) eq $contentpwd);   if((getpwnam($uname))[1] eq "") { #no such user!
                           } elsif ($howpwd eq 'krb4') {      $pwdcorrect = 0;
                               $pwdcorrect=(   } else {
                                  Authen::Krb4::get_pw_in_tkt($uname,"",      $contentpwd=(getpwnam($uname))[1];
                                         $contentpwd,'krbtgt',$contentpwd,1,      my $pwauth_path="/usr/local/sbin/pwauth";
      $upass) == 0);      unless ($contentpwd eq 'x') {
                           }   $pwdcorrect=
                           if ($pwdcorrect) {      (crypt($upass,$contentpwd) eq 
                              print $client "authorized\n";       $contentpwd);
                           } else {      }
                              print $client "non_authorized\n";      
                           }        elsif (-e $pwauth_path) {
        } else {   open PWAUTH, "|$pwauth_path" or
                           print $client "unknown_user\n";      die "Cannot invoke authentication";
                        }   print PWAUTH "$uname\n$upass\n";
      } else {   close PWAUTH;
        print $client "refused\n";   $pwdcorrect=!$?;
      }      }
    }
       } elsif ($howpwd eq 'krb4') {
    my $null=pack("C",0);
    unless ($upass=~/$null/) {
       my $krb4_error = &Authen::Krb4::get_pw_in_tkt
    ($uname,"",$contentpwd,'krbtgt',
    $contentpwd,1,$upass);
       if (!$krb4_error) {
    $pwdcorrect = 1;
       } else { 
    $pwdcorrect=0; 
    # log error if it is not a bad password
    if ($krb4_error != 62) {
       &logthis('krb4:'.$uname.','.
        &Authen::Krb4::get_err_txt($Authen::Krb4::error));
    }
       }
    }
       } elsif ($howpwd eq 'krb5') {
    my $null=pack("C",0);
    unless ($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 {
    print $client "non_authorized\n";
       }  
    } else {
       print $client "unknown_user\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
          
       }
 # ---------------------------------------------------------------------- passwd  # ---------------------------------------------------------------------- passwd
                    } elsif ($userinput =~ /^passwd/) {   } elsif ($userinput =~ /^passwd/) { # encoded and client
      if ($wasenc==1) {      if (($wasenc==1) && isClient) {
                        my    my 
                        ($cmd,$udom,$uname,$upass,$npass)=split(/:/,$userinput);      ($cmd,$udom,$uname,$upass,$npass)=split(/:/,$userinput);
                        chomp($npass);   chomp($npass);
                        $upass=&unescape($upass);   $upass=&unescape($upass);
                        $npass=&unescape($npass);   $npass=&unescape($npass);
                        my $proname=propath($udom,$uname);   &Debug("Trying to change password for $uname");
                        my $passfilename="$proname/passwd";   my $proname=propath($udom,$uname);
                        if (-e $passfilename) {   my $passfilename="$proname/passwd";
    my $realpasswd;   if (-e $passfilename) {
                           { my $pf = IO::File->new($passfilename);      my $realpasswd;
     $realpasswd=<$pf>; }      { my $pf = IO::File->new($passfilename);
                           chomp($realpasswd);        $realpasswd=<$pf>; }
                           my ($howpwd,$contentpwd)=split(/:/,$realpasswd);      chomp($realpasswd);
                           if ($howpwd eq 'internal') {      my ($howpwd,$contentpwd)=split(/:/,$realpasswd);
    if (crypt($upass,$contentpwd) eq $contentpwd) {      if ($howpwd eq 'internal') {
      my $salt=time;   &Debug("internal auth");
                              $salt=substr($salt,6,2);   if (crypt($upass,$contentpwd) eq $contentpwd) {
      my $ncpass=crypt($npass,$salt);      my $salt=time;
                              { my $pf = IO::File->new(">$passfilename");      $salt=substr($salt,6,2);
           print $pf "internal:$ncpass\n"; }                   my $ncpass=crypt($npass,$salt);
                              print $client "ok\n";      {
                            } else {   my $pf;
                              print $client "non_authorized\n";   if ($pf = IO::File->new(">$passfilename")) {
                            }      print $pf "internal:$ncpass\n";
                           } else {      &logthis("Result of password change for $uname: pwchange_success");
                             print $client "auth_mode_error\n";      print $client "ok\n";
                           }     } else {
        } else {      &logthis("Unable to open $uname passwd to change password");
                           print $client "unknown_user\n";      print $client "non_authorized\n";
                        }   }
      } else {      }             
        print $client "refused\n";      
      }   } else {
       print $client "non_authorized\n";
    }
       } elsif ($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 > $perlvar{'lonDaemons'}/logs/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 {
       print $client "unknown_user\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
          
       }
 # -------------------------------------------------------------------- makeuser  # -------------------------------------------------------------------- makeuser
                    } elsif ($userinput =~ /^makeuser/) {   } elsif ($userinput =~ /^makeuser/) { # encoded and client.
      if ($wasenc==1) {      &Debug("Make user received");
                        my       my $oldumask=umask(0077);
                        ($cmd,$udom,$uname,$umode,$npass)=split(/:/,$userinput);      if (($wasenc==1) && isClient) {
                        chomp($npass);   my 
                        $npass=&unescape($npass);      ($cmd,$udom,$uname,$umode,$npass)=split(/:/,$userinput);
                        my $proname=propath($udom,$uname);   &Debug("cmd =".$cmd." $udom =".$udom.
                        my $passfilename="$proname/passwd";         " uname=".$uname);
                        if (-e $passfilename) {   chomp($npass);
    print $client "already_exists\n";   $npass=&unescape($npass);
                        } elsif ($udom ne $perlvar{'lonDefDomain'}) {   my $proname=propath($udom,$uname);
                            print $client "not_right_domain\n";   my $passfilename="$proname/passwd";
                        } else {   &Debug("Password file created will be:".
                            @fpparts=split(/\//,$proname);         $passfilename);
                            $fpnow=$fpparts[0].'/'.$fpparts[1].'/'.$fpparts[2];   if (-e $passfilename) {
                            $fperror='';      print $client "already_exists\n";
                            for ($i=3;$i<=$#fpparts;$i++) {   } elsif ($udom ne $currentdomainid) {
                                $fpnow.='/'.$fpparts[$i];       print $client "not_right_domain\n";
                                unless (-e $fpnow) {   } else {
    unless (mkdir($fpnow,0777)) {      my @fpparts=split(/\//,$proname);
                                       $fperror="error:$!\n";      my $fpnow=$fpparts[0].'/'.$fpparts[1].'/'.$fpparts[2];
                                    }      my $fperror='';
                                }      for (my $i=3;$i<=$#fpparts;$i++) {
                            }   $fpnow.='/'.$fpparts[$i]; 
                            unless ($fperror) {   unless (-e $fpnow) {
      if ($umode eq 'krb4') {      unless (mkdir($fpnow,0777)) {
                                {    $fperror="error: ".($!+0)
                                  my $pf = IO::File->new(">$passfilename");      ." mkdir failed while attempting "
             print $pf "krb4:$npass\n";       ."makeuser";
                                }                   }
                                print $client "ok\n";   }
                              } elsif ($umode eq 'internal') {      }
        my $salt=time;      unless ($fperror) {
                                $salt=substr($salt,6,2);   my $result=&make_passwd_file($uname, $umode,$npass,
        my $ncpass=crypt($npass,$salt);       $passfilename);
                                {    print $client $result;
                                  my $pf = IO::File->new(">$passfilename");      } else {
             print $pf "internal:$ncpass\n";    print $client "$fperror\n";
                                }                   }
                                print $client "ok\n";   }
                              } elsif ($umode eq 'none') {      } else {
                                {    Reply($client, "refused\n", $userinput);
                                  my $pf = IO::File->new(">$passfilename");        
             print $pf "none:\n";       }
                                }                   umask($oldumask);
                                print $client "ok\n";  # -------------------------------------------------------------- changeuserauth
                              } else {   } elsif ($userinput =~ /^changeuserauth/) { # encoded & client
                                print $client "auth_mode_error\n";      &Debug("Changing authorization");
                              }        if (($wasenc==1) && isClient) {
                            } else {   my 
                                print $client "$fperror\n";      ($cmd,$udom,$uname,$umode,$npass)=split(/:/,$userinput);
                            }   chomp($npass);
                        }   &Debug("cmd = ".$cmd." domain= ".$udom.
      } else {         "uname =".$uname." umode= ".$umode);
        print $client "refused\n";   $npass=&unescape($npass);
      }   my $proname=&propath($udom,$uname);
    my $passfilename="$proname/passwd";
    if ($udom ne $currentdomainid) {
       print $client "not_right_domain\n";
    } else {
       my $result=&make_passwd_file($uname, $umode,$npass,
    $passfilename);
       print $client $result;
    }
       } else {
    Reply($client, "refused\n", $userinput);
      
       }
 # ------------------------------------------------------------------------ home  # ------------------------------------------------------------------------ home
                    } elsif ($userinput =~ /^home/) {   } elsif ($userinput =~ /^home/) { # client clear or encoded
                        my ($cmd,$udom,$uname)=split(/:/,$userinput);      if(isClient) {
                        chomp($uname);   my ($cmd,$udom,$uname)=split(/:/,$userinput);
                        my $proname=propath($udom,$uname);   chomp($uname);
                        if (-e $proname) {   my $proname=propath($udom,$uname);
                           print $client "found\n";   if (-e $proname) {
                        } else {      print $client "found\n";
   print $client "not_found\n";   } else {
                        }      print $client "not_found\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
   
       }
 # ---------------------------------------------------------------------- update  # ---------------------------------------------------------------------- update
                    } elsif ($userinput =~ /^update/) {   } elsif ($userinput =~ /^update/) { # client clear or encoded.
                        my ($cmd,$fname)=split(/:/,$userinput);      if(isClient) {
                        my $ownership=ishome($fname);   my ($cmd,$fname)=split(/:/,$userinput);
                        if ($ownership eq 'not_owner') {   my $ownership=ishome($fname);
                         if (-e $fname) {   if ($ownership eq 'not_owner') {
                           my ($dev,$ino,$mode,$nlink,      if (-e $fname) {
                               $uid,$gid,$rdev,$size,   my ($dev,$ino,$mode,$nlink,
                               $atime,$mtime,$ctime,      $uid,$gid,$rdev,$size,
                               $blksize,$blocks)=stat($fname);      $atime,$mtime,$ctime,
                           $now=time;      $blksize,$blocks)=stat($fname);
                           $since=$now-$atime;   my $now=time;
                           if ($since>$perlvar{'lonExpire'}) {   my $since=$now-$atime;
                               $reply=   if ($since>$perlvar{'lonExpire'}) {
                                     reply("unsub:$fname","$hostid{$clientip}");      my $reply=
                               unlink("$fname");   &reply("unsub:$fname","$clientname");
                           } else {      unlink("$fname");
      my $transname="$fname.in.transfer";   } else {
                              my $remoteurl=      my $transname="$fname.in.transfer";
                                     reply("sub:$fname","$hostid{$clientip}");      my $remoteurl=
                              my $response;   &reply("sub:$fname","$clientname");
                               {      my $response;
                              my $ua=new LWP::UserAgent;      {
                              my $request=new HTTP::Request('GET',"$remoteurl");   my $ua=new LWP::UserAgent;
                              $response=$ua->request($request,$transname);   my $request=new HTTP::Request('GET',"$remoteurl");
       }   $response=$ua->request($request,$transname);
                              if ($response->is_error()) {      }
  unlink($transname);      if ($response->is_error()) {
                                  my $message=$response->status_line;   unlink($transname);
                                  &logthis(   my $message=$response->status_line;
                                   "LWP GET: $message for $fname ($remoteurl)");   &logthis(
                              } else {   "LWP GET: $message for $fname ($remoteurl)");
                          if ($remoteurl!~/\.meta$/) {      } else {
                                   my $ua=new LWP::UserAgent;   if ($remoteurl!~/\.meta$/) {
                                   my $mrequest=      my $ua=new LWP::UserAgent;
                                    new HTTP::Request('GET',$remoteurl.'.meta');      my $mrequest=
                                   my $mresponse=   new HTTP::Request('GET',$remoteurl.'.meta');
                                    $ua->request($mrequest,$fname.'.meta');      my $mresponse=
                                   if ($mresponse->is_error()) {   $ua->request($mrequest,$fname.'.meta');
                     unlink($fname.'.meta');      if ($mresponse->is_error()) {
                                   }   unlink($fname.'.meta');
                          }      }
                                  rename($transname,$fname);   }
      }   rename($transname,$fname);
                           }      }
                           print $client "ok\n";   }
                         } else {   print $client "ok\n";
                           print $client "not_found\n";      } else {
                         }   print $client "not_found\n";
        } else {      }
  print $client "rejected\n";   } else {
                        }      print $client "rejected\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
   
       }
   # -------------------------------------- fetch a user file from a remote server
    } elsif ($userinput =~ /^fetchuserfile/) { # Client clear or enc.
       if(isClient) {
    my ($cmd,$fname)=split(/:/,$userinput);
    my ($udom,$uname,$ufile) = ($fname =~ m|^([^/]+)/([^/]+)/(.+)$|);
    my $udir=propath($udom,$uname).'/userfiles';
    unless (-e $udir) { mkdir($udir,0770); }
    if (-e $udir) {
                               $ufile=~s/^[\.\~]+//;
                               my $path = $udir;
                               if ($ufile =~m|(.+)/([^/]+)$|) {
                                   my @parts=split('/',$1);
                                   foreach my $part (@parts) {
                                       $path .= '/'.$part;
                                       if ((-e $path)!=1) {
                                           mkdir($path,0770);
                                       }
                                   }
                               }
       my $destname=$udir.'/'.$ufile;
       my $transname=$udir.'/'.$ufile.'.in.transit';
       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 $client "failed\n";
       } else {
    if (!rename($transname,$destname)) {
       &logthis("Unable to move $transname to $destname");
       unlink($transname);
       print $client "failed\n";
    } else {
       print $client "ok\n";
    }
       }
    } else {
       print $client "not_home\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
       }
   # --------------------------------------------------------- remove a user file 
    } elsif ($userinput =~ /^removeuserfile/) { # Client clear or enc.
       if(isClient) {
    my ($cmd,$fname)=split(/:/,$userinput);
    my ($udom,$uname,$ufile) = ($fname =~ m|^([^/]+)/([^/]+)/(.+)$|);
    &logthis("$udom - $uname - $ufile");
    if ($ufile =~m|/\.\./|) {
       # any files paths with /../ in them refuse 
                               # to deal with
       print $client "refused\n";
    } else {
       my $udir=propath($udom,$uname);
       if (-e $udir) {
    my $file=$udir.'/userfiles/'.$ufile;
    if (-e $file) {
       unlink($file);
       if (-e $file) {
    print $client "failed\n";
       } else {
    print $client "ok\n";
       }
    } else {
       print $client "not_found\n";
    }
       } else {
    print $client "not_home\n";
       }
    }
       } else {
    Reply($client, "refused\n", $userinput);
       }
   # ------------------------------------------ authenticate access to a user file
    } elsif ($userinput =~ /^tokenauthuserfile/) { # Client only
       if(isClient) {
    my ($cmd,$fname,$session)=split(/:/,$userinput);
    chomp($session);
    my $reply='non_auth';
    if (open(ENVIN,$perlvar{'lonIDsDir'}.'/'.
    $session.'.id')) {
       while (my $line=<ENVIN>) {
    if ($line=~ m|userfile\.\Q$fname\E\=|) { $reply='ok'; }
       }
       close(ENVIN);
       print $client $reply."\n";
    } else {
       print $client "invalid_token\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
   
       }
 # ----------------------------------------------------------------- unsubscribe  # ----------------------------------------------------------------- unsubscribe
                    } elsif ($userinput =~ /^unsub/) {   } elsif ($userinput =~ /^unsub/) {
                        my ($cmd,$fname)=split(/:/,$userinput);      if(isClient) {
                        if (-e $fname) {   my ($cmd,$fname)=split(/:/,$userinput);
                            if (unlink("$fname.$hostid{$clientip}")) {   if (-e $fname) {
                               print $client "ok\n";      print $client &unsub($fname,$clientip);
    } else {   } else {
                               print $client "not_subscribed\n";      print $client "not_found\n";
    }   }
                        } else {      } else {
    print $client "not_found\n";   Reply($client, "refused\n", $userinput);
                        }  
       }
 # ------------------------------------------------------------------- subscribe  # ------------------------------------------------------------------- subscribe
                    } elsif ($userinput =~ /^sub/) {   } elsif ($userinput =~ /^sub/) {
                        my ($cmd,$fname)=split(/:/,$userinput);      if(isClient) {
                        my $ownership=ishome($fname);   print $client &subscribe($userinput,$clientip);
                        if ($ownership eq 'owner') {      } else {
                         if (-e $fname) {   Reply($client, "refused\n", $userinput);
  if (-d $fname) {  
    print $client "directory\n";      }
                          } else {  # ------------------------------------------------------------- current version
                            $now=time;   } elsif ($userinput =~ /^currentversion/) {
                            {       if(isClient) {
     my $sh;   my ($cmd,$fname)=split(/:/,$userinput);
                             if ($sh=   print $client &currentversion($fname)."\n";
                              IO::File->new(">$fname.$hostid{$clientip}")) {      } else {
                                print $sh "$clientip:$now\n";   Reply($client, "refused\n", $userinput);
     }  
    }      }
                            unless ($fname=~/\.meta$/) {  
        unlink("$fname.meta.$hostid{$clientip}");  
                            }  
                            $fname=~s/\/home\/httpd\/html\/res/raw/;  
                            $fname="http://$thisserver/".$fname;  
                            print $client "$fname\n";  
          }  
                         } else {  
          print $client "not_found\n";  
                         }  
        } else {  
                         print $client "rejected\n";  
        }  
 # ------------------------------------------------------------------------- log  # ------------------------------------------------------------------------- log
                    } elsif ($userinput =~ /^log/) {   } elsif ($userinput =~ /^log/) {
                        my ($cmd,$udom,$uname,$what)=split(/:/,$userinput);      if(isClient) {
                        chomp($what);   my ($cmd,$udom,$uname,$what)=split(/:/,$userinput);
                        my $proname=propath($udom,$uname);   chomp($what);
                        my $now=time;   my $proname=propath($udom,$uname);
                        {   my $now=time;
  my $hfh;   {
  if ($hfh=IO::File->new(">>$proname/activity.log")) {       my $hfh;
                             print $hfh "$now:$hostid{$clientip}:$what\n";      if ($hfh=IO::File->new(">>$proname/activity.log")) { 
                             print $client "ok\n";    print $hfh "$now:$clientname:$what\n";
  } else {   print $client "ok\n"; 
                             print $client "error:$!\n";      } else {
         }   print $client "error: ".($!+0)
        }      ." IO::File->new Failed "
       ."while attempting log\n";
       }
    }
       } else {
    Reply($client, "refused\n", $userinput);
   
       }
 # ------------------------------------------------------------------------- put  # ------------------------------------------------------------------------- put
                    } elsif ($userinput =~ /^put/) {   } elsif ($userinput =~ /^put/) {
                       my ($cmd,$udom,$uname,$namespace,$what)      if(isClient) {
                           =split(/:/,$userinput);   my ($cmd,$udom,$uname,$namespace,$what)
                       $namespace=~s/\//\_/g;      =split(/:/,$userinput);
                       $namespace=~s/\W//g;   $namespace=~s/\//\_/g;
                       if ($namespace ne 'roles') {   $namespace=~s/\W//g;
                        chomp($what);   if ($namespace ne 'roles') {
                        my $proname=propath($udom,$uname);      chomp($what);
                        my $now=time;      my $proname=propath($udom,$uname);
                        {      my $now=time;
    my $hfh;      unless ($namespace=~/^nohist\_/) {
    if (   my $hfh;
                              $hfh=IO::File->new(">>$proname/$namespace.hist")   if (
        ) { print $hfh "P:$now:$what\n"; }      $hfh=IO::File->new(">>$proname/$namespace.hist")
        }      ) { print $hfh "P:$now:$what\n"; }
                        my @pairs=split(/\&/,$what);      }
       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_WRCREAT,0640)) {      my @pairs=split(/\&/,$what);
                            foreach $pair (@pairs) {      my %hash;
        ($key,$value)=split(/=/,$pair);      if (tie(%hash,'GDBM_File',
                                $hash{$key}=$value;      "$proname/$namespace.db",
                            }      &GDBM_WRCREAT(),0640)) {
    if (untie(%hash)) {   foreach my $pair (@pairs) {
                               print $client "ok\n";      my ($key,$value)=split(/=/,$pair);
                            } else {      $hash{$key}=$value;
                               print $client "error:$!\n";   }
                            }   if (untie(%hash)) {
                        } else {      print $client "ok\n";
                            print $client "error:$!\n";   } else {
                        }      print $client "error: ".($!+0)
       } else {   ." untie(GDBM) failed ".
                           print $client "refused\n";   "while attempting put\n";
                       }   }
       } else {
    print $client "error: ".($!)
       ." tie(GDBM) Failed ".
       "while attempting put\n";
       }
    } else {
       print $client "refused\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
   
       }
   # ------------------------------------------------------------------- inc
    } elsif ($userinput =~ /^inc:/) {
       if(isClient) {
    my ($cmd,$udom,$uname,$namespace,$what)
       =split(/:/,$userinput);
    $namespace=~s/\//\_/g;
    $namespace=~s/\W//g;
    if ($namespace ne 'roles') {
       chomp($what);
       my $proname=propath($udom,$uname);
       my $now=time;
       unless ($namespace=~/^nohist\_/) {
    my $hfh;
    if (
       $hfh=IO::File->new(">>$proname/$namespace.hist")
       ) { print $hfh "P:$now:$what\n"; }
       }
       my @pairs=split(/\&/,$what);
       my %hash;
       if (tie(%hash,'GDBM_File',
       "$proname/$namespace.db",
       &GDBM_WRCREAT(),0640)) {
    foreach my $pair (@pairs) {
       my ($key,$value)=split(/=/,$pair);
                                       # We could check that we have a number...
                                       if (! defined($value) || $value eq '') {
                                           $value = 1;
                                       }
       $hash{$key}+=$value;
    }
    if (untie(%hash)) {
       print $client "ok\n";
    } else {
       print $client "error: ".($!+0)
    ." untie(GDBM) failed ".
    "while attempting inc\n";
    }
       } else {
    print $client "error: ".($!)
       ." tie(GDBM) Failed ".
       "while attempting inc\n";
       }
    } else {
       print $client "refused\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
   
       }
 # -------------------------------------------------------------------- rolesput  # -------------------------------------------------------------------- rolesput
                    } elsif ($userinput =~ /^rolesput/) {   } elsif ($userinput =~ /^rolesput/) {
     if ($wasenc==1) {      if(isClient) {
                        my ($cmd,$exedom,$exeuser,$udom,$uname,$what)   &Debug("rolesput");
                           =split(/:/,$userinput);   if ($wasenc==1) {
                        my $namespace='roles';      my ($cmd,$exedom,$exeuser,$udom,$uname,$what)
                        chomp($what);   =split(/:/,$userinput);
                        my $proname=propath($udom,$uname);      &Debug("cmd = ".$cmd." exedom= ".$exedom.
                        my $now=time;     "user = ".$exeuser." udom=".$udom.
                        {     "what = ".$what);
    my $hfh;      my $namespace='roles';
    if (      chomp($what);
                              $hfh=IO::File->new(">>$proname/$namespace.hist")      my $proname=propath($udom,$uname);
        ) {       my $now=time;
                                   print $hfh "P:$now:$exedom:$exeuser:$what\n";      {
                                  }   my $hfh;
        }   if (
                        my @pairs=split(/\&/,$what);      $hfh=IO::File->new(">>$proname/$namespace.hist")
       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_WRCREAT,0640)) {      ) { 
                            foreach $pair (@pairs) {      print $hfh "P:$now:$exedom:$exeuser:$what\n";
        ($key,$value)=split(/=/,$pair);   }
                                $hash{$key}=$value;      }
                            }      my @pairs=split(/\&/,$what);
    if (untie(%hash)) {      my %hash;
                               print $client "ok\n";      if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_WRCREAT(),0640)) {
                            } else {   foreach my $pair (@pairs) {
                               print $client "error:$!\n";      my ($key,$value)=split(/=/,$pair);
                            }      &ManagePermissions($key, $udom, $uname,
                        } else {         &GetAuthType( $udom, 
                            print $client "error:$!\n";       $uname));
                        }      $hash{$key}=$value;
       } else {   }
                           print $client "refused\n";   if (untie(%hash)) {
                       }      print $client "ok\n";
    } else {
       print $client "error: ".($!+0)
    ." untie(GDBM) Failed ".
    "while attempting rolesput\n";
    }
       } else {
    print $client "error: ".($!+0)
       ." tie(GDBM) Failed ".
       "while attempting rolesput\n";
       }
    } else {
       print $client "refused\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
     
       }
   # -------------------------------------------------------------------- rolesdel
    } elsif ($userinput =~ /^rolesdel/) {
       if(isClient) {
    &Debug("rolesdel");
    if ($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);
       my $now=time;
       {
    my $hfh;
    if (
       $hfh=IO::File->new(">>$proname/$namespace.hist")
       ) { 
       print $hfh "D:$now:$exedom:$exeuser:$what\n";
    }
       }
       my @rolekeys=split(/\&/,$what);
       my %hash;
       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_WRCREAT(),0640)) {
    foreach my $key (@rolekeys) {
       delete $hash{$key};
    }
    if (untie(%hash)) {
       print $client "ok\n";
    } else {
       print $client "error: ".($!+0)
    ." untie(GDBM) Failed ".
    "while attempting rolesdel\n";
    }
       } else {
    print $client "error: ".($!+0)
       ." tie(GDBM) Failed ".
       "while attempting rolesdel\n";
       }
    } else {
       print $client "refused\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
         
       }
 # ------------------------------------------------------------------------- get  # ------------------------------------------------------------------------- get
                    } elsif ($userinput =~ /^get/) {   } elsif ($userinput =~ /^get/) {
                        my ($cmd,$udom,$uname,$namespace,$what)      if(isClient) {
                           =split(/:/,$userinput);   my ($cmd,$udom,$uname,$namespace,$what)
                        $namespace=~s/\//\_/g;      =split(/:/,$userinput);
                        $namespace=~s/\W//g;   $namespace=~s/\//\_/g;
                        chomp($what);   $namespace=~s/\W//g;
                        my @queries=split(/\&/,$what);   chomp($what);
                        my $proname=propath($udom,$uname);   my @queries=split(/\&/,$what);
                        my $qresult='';   my $proname=propath($udom,$uname);
       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER,0640)) {   my $qresult='';
                            for ($i=0;$i<=$#queries;$i++) {   my %hash;
                                $qresult.="$hash{$queries[$i]}&";   if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER(),0640)) {
                            }      for (my $i=0;$i<=$#queries;$i++) {
    if (untie(%hash)) {   $qresult.="$hash{$queries[$i]}&";
               $qresult=~s/\&$//;      }
                               print $client "$qresult\n";      if (untie(%hash)) {
                            } else {   $qresult=~s/\&$//;
                               print $client "error:$!\n";   print $client "$qresult\n";
                            }      } else {
                        } else {   print $client "error: ".($!+0)
                            print $client "error:$!\n";      ." untie(GDBM) Failed ".
                        }      "while attempting get\n";
       }
    } else {
       if ($!+0 == 2) {
    print $client "error:No such file or ".
       "GDBM reported bad block error\n";
       } else {
    print $client "error: ".($!+0)
       ." tie(GDBM) Failed ".
       "while attempting get\n";
       }
    }
       } else {
    Reply($client, "refused\n", $userinput);
          
       }
 # ------------------------------------------------------------------------ eget  # ------------------------------------------------------------------------ eget
                    } elsif ($userinput =~ /^eget/) {   } elsif ($userinput =~ /^eget/) {
                        my ($cmd,$udom,$uname,$namespace,$what)      if (isClient) {
                           =split(/:/,$userinput);   my ($cmd,$udom,$uname,$namespace,$what)
                        $namespace=~s/\//\_/g;      =split(/:/,$userinput);
                        $namespace=~s/\W//g;   $namespace=~s/\//\_/g;
                        chomp($what);   $namespace=~s/\W//g;
                        my @queries=split(/\&/,$what);   chomp($what);
                        my $proname=propath($udom,$uname);   my @queries=split(/\&/,$what);
                        my $qresult='';   my $proname=propath($udom,$uname);
       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER,0640)) {   my $qresult='';
                            for ($i=0;$i<=$#queries;$i++) {   my %hash;
                                $qresult.="$hash{$queries[$i]}&";   if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER(),0640)) {
                            }      for (my $i=0;$i<=$#queries;$i++) {
    if (untie(%hash)) {   $qresult.="$hash{$queries[$i]}&";
               $qresult=~s/\&$//;      }
                               if ($cipher) {      if (untie(%hash)) {
                                 my $cmdlength=length($qresult);   $qresult=~s/\&$//;
                                 $qresult.="         ";   if ($cipher) {
                                 my $encqresult='';      my $cmdlength=length($qresult);
                                 for       $qresult.="         ";
  (my $encidx=0;$encidx<=$cmdlength;$encidx+=8) {      my $encqresult='';
                                  $encqresult.=      for 
                                  unpack("H16",   (my $encidx=0;$encidx<=$cmdlength;$encidx+=8) {
                                  $cipher->encrypt(substr($qresult,$encidx,8)));      $encqresult.=
                                 }   unpack("H16",
                                 print $client "enc:$cmdlength:$encqresult\n";         $cipher->encrypt(substr($qresult,$encidx,8)));
       } else {   }
         print $client "error:no_key\n";      print $client "enc:$cmdlength:$encqresult\n";
                               }   } else {
                            } else {      print $client "error:no_key\n";
                               print $client "error:$!\n";   }
                            }      } else {
                        } else {   print $client "error: ".($!+0)
                            print $client "error:$!\n";      ." untie(GDBM) Failed ".
                        }      "while attempting eget\n";
       }
    } else {
       print $client "error: ".($!+0)
    ." tie(GDBM) Failed ".
    "while attempting eget\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
       
       }
 # ------------------------------------------------------------------------- del  # ------------------------------------------------------------------------- del
                    } elsif ($userinput =~ /^del/) {   } elsif ($userinput =~ /^del/) {
                        my ($cmd,$udom,$uname,$namespace,$what)      if(isClient) {
                           =split(/:/,$userinput);   my ($cmd,$udom,$uname,$namespace,$what)
                        $namespace=~s/\//\_/g;      =split(/:/,$userinput);
                        $namespace=~s/\W//g;   $namespace=~s/\//\_/g;
                        chomp($what);   $namespace=~s/\W//g;
                        my $proname=propath($udom,$uname);   chomp($what);
                        my $now=time;   my $proname=propath($udom,$uname);
                        {   my $now=time;
    my $hfh;   unless ($namespace=~/^nohist\_/) {
    if (      my $hfh;
                              $hfh=IO::File->new(">>$proname/$namespace.hist")      if (
        ) { print $hfh "D:$now:$what\n"; }   $hfh=IO::File->new(">>$proname/$namespace.hist")
        }   ) { print $hfh "D:$now:$what\n"; }
                        my @keys=split(/\&/,$what);   }
       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_WRCREAT,0640)) {   my @keys=split(/\&/,$what);
                            foreach $key (@keys) {   my %hash;
                                delete($hash{$key});   if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_WRCREAT(),0640)) {
                            }      foreach my $key (@keys) {
    if (untie(%hash)) {   delete($hash{$key});
                               print $client "ok\n";      }
                            } else {      if (untie(%hash)) {
                               print $client "error:$!\n";   print $client "ok\n";
                            }      } else {
                        } else {   print $client "error: ".($!+0)
                            print $client "error:$!\n";      ." untie(GDBM) Failed ".
                        }      "while attempting del\n";
       }
    } else {
       print $client "error: ".($!+0)
    ." tie(GDBM) Failed ".
    "while attempting del\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
   
       }
 # ------------------------------------------------------------------------ keys  # ------------------------------------------------------------------------ keys
                    } elsif ($userinput =~ /^keys/) {   } elsif ($userinput =~ /^keys/) {
                        my ($cmd,$udom,$uname,$namespace)      if(isClient) {
                           =split(/:/,$userinput);   my ($cmd,$udom,$uname,$namespace)
                        $namespace=~s/\//\_/g;      =split(/:/,$userinput);
                        $namespace=~s/\W//g;   $namespace=~s/\//\_/g;
                        my $proname=propath($udom,$uname);   $namespace=~s/\W//g;
                        my $qresult='';   my $proname=propath($udom,$uname);
       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER,0640)) {   my $qresult='';
                            foreach $key (keys %hash) {   my %hash;
                                $qresult.="$key&";   if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER(),0640)) {
                            }      foreach my $key (keys %hash) {
    if (untie(%hash)) {   $qresult.="$key&";
               $qresult=~s/\&$//;      }
                               print $client "$qresult\n";      if (untie(%hash)) {
                            } else {   $qresult=~s/\&$//;
                               print $client "error:$!\n";   print $client "$qresult\n";
                            }      } else {
                        } else {   print $client "error: ".($!+0)
                            print $client "error:$!\n";      ." untie(GDBM) Failed ".
                        }      "while attempting keys\n";
       }
    } else {
       print $client "error: ".($!+0)
    ." tie(GDBM) Failed ".
    "while attempting keys\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
      
       }
   # ----------------------------------------------------------------- dumpcurrent
    } elsif ($userinput =~ /^currentdump/) {
       if (isClient) {
    my ($cmd,$udom,$uname,$namespace)
       =split(/:/,$userinput);
    $namespace=~s/\//\_/g;
    $namespace=~s/\W//g;
    my $qresult='';
    my $proname=propath($udom,$uname);
    my %hash;
    if (tie(%hash,'GDBM_File',
    "$proname/$namespace.db",
    &GDBM_READER(),0640)) {
       # Structure of %data:
       # $data{$symb}->{$parameter}=$value;
       # $data{$symb}->{'v.'.$parameter}=$version;
       # since $parameter will be unescaped, we do not
       # have to worry about silly parameter names...
       my %data = ();
       while (my ($key,$value) = each(%hash)) {
    my ($v,$symb,$param) = split(/:/,$key);
    next if ($v eq 'version' || $symb eq 'keys');
    next if (exists($data{$symb}) && 
    exists($data{$symb}->{$param}) &&
    $data{$symb}->{'v.'.$param} > $v);
    $data{$symb}->{$param}=$value;
    $data{$symb}->{'v.'.$param}=$v;
       }
       if (untie(%hash)) {
    while (my ($symb,$param_hash) = each(%data)) {
       while(my ($param,$value) = each (%$param_hash)){
    next if ($param =~ /^v\./);
    $qresult.=$symb.':'.$param.'='.$value.'&';
       }
    }
    chop($qresult);
    print $client "$qresult\n";
       } else {
    print $client "error: ".($!+0)
       ." untie(GDBM) Failed ".
       "while attempting currentdump\n";
       }
    } else {
       print $client "error: ".($!+0)
    ." tie(GDBM) Failed ".
    "while attempting currentdump\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
       }
 # ------------------------------------------------------------------------ dump  # ------------------------------------------------------------------------ dump
                    } elsif ($userinput =~ /^dump/) {   } elsif ($userinput =~ /^dump/) {
                        my ($cmd,$udom,$uname,$namespace)      if(isClient) {
                           =split(/:/,$userinput);   my ($cmd,$udom,$uname,$namespace,$regexp)
                        $namespace=~s/\//\_/g;      =split(/:/,$userinput);
                        $namespace=~s/\W//g;   $namespace=~s/\//\_/g;
                        my $proname=propath($udom,$uname);   $namespace=~s/\W//g;
                        my $qresult='';   if (defined($regexp)) {
       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER,0640)) {      $regexp=&unescape($regexp);
                            foreach $key (keys %hash) {   } else {
                                $qresult.="$key=$hash{$key}&";      $regexp='.';
                            }   }
    if (untie(%hash)) {   my $qresult='';
               $qresult=~s/\&$//;   my $proname=propath($udom,$uname);
                               print $client "$qresult\n";   my %hash;
                            } else {   if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER(),0640)) {
                               print $client "error:$!\n";         while (my ($key,$value) = each(%hash)) {
                            }     if ($regexp eq '.') {
                        } else {         $qresult.=$key.'='.$value.'&';
                            print $client "error:$!\n";     } else {
                        }         my $unescapeKey = &unescape($key);
          if (eval('$unescapeKey=~/$regexp/')) {
      $qresult.="$key=$value&";
          }
      }
          }
          if (untie(%hash)) {
      chop($qresult);
      print $client "$qresult\n";
          } else {
      print $client "error: ".($!+0)
          ." untie(GDBM) Failed ".
                                          "while attempting dump\n";
          }
      } else {
          print $client "error: ".($!+0)
      ." tie(GDBM) Failed ".
      "while attempting dump\n";
      }
       } else {
    Reply($client, "refused\n", $userinput);
     
       }
 # ----------------------------------------------------------------------- store  # ----------------------------------------------------------------------- store
                    } elsif ($userinput =~ /^store/) {   } elsif ($userinput =~ /^store/) {
                       my ($cmd,$udom,$uname,$namespace,$rid,$what)      if(isClient) {
                           =split(/:/,$userinput);   my ($cmd,$udom,$uname,$namespace,$rid,$what)
                       $namespace=~s/\//\_/g;      =split(/:/,$userinput);
                       $namespace=~s/\W//g;   $namespace=~s/\//\_/g;
                       if ($namespace ne 'roles') {   $namespace=~s/\W//g;
                        chomp($what);   if ($namespace ne 'roles') {
                        my $proname=propath($udom,$uname);      chomp($what);
                        my $now=time;      my $proname=propath($udom,$uname);
                        {      my $now=time;
    my $hfh;      unless ($namespace=~/^nohist\_/) {
    if (   my $hfh;
                              $hfh=IO::File->new(">>$proname/$namespace.hist")   if (
        ) { print $hfh "P:$now:$rid:$what\n"; }      $hfh=IO::File->new(">>$proname/$namespace.hist")
        }      ) { print $hfh "P:$now:$rid:$what\n"; }
                        my @pairs=split(/\&/,$what);      }
                                my @pairs=split(/\&/,$what);
     if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_WRCREAT,0640)) {      my %hash;
                            my @previouskeys=split(/&/,$hash{"keys:$rid"});      if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_WRCREAT(),0640)) {
                            my $key;   my @previouskeys=split(/&/,$hash{"keys:$rid"});
                            $hash{"version:$rid"}++;   my $key;
                            my $version=$hash{"version:$rid"};   $hash{"version:$rid"}++;
                            my $allkeys='';    my $version=$hash{"version:$rid"};
                            foreach $pair (@pairs) {   my $allkeys=''; 
        ($key,$value)=split(/=/,$pair);   foreach my $pair (@pairs) {
                                $allkeys.=$key.':';      my ($key,$value)=split(/=/,$pair);
                                $hash{"$version:$rid:$key"}=$value;      $allkeys.=$key.':';
                            }      $hash{"$version:$rid:$key"}=$value;
                            $hash{"$version:$rid:timestamp"}=$now;   }
                            $allkeys.='timestamp';   $hash{"$version:$rid:timestamp"}=$now;
                            $hash{"$version:keys:$rid"}=$allkeys;   $allkeys.='timestamp';
    if (untie(%hash)) {   $hash{"$version:keys:$rid"}=$allkeys;
                               print $client "ok\n";   if (untie(%hash)) {
                            } else {      print $client "ok\n";
                               print $client "error:$!\n";   } else {
                            }      print $client "error: ".($!+0)
                        } else {   ." untie(GDBM) Failed ".
                            print $client "error:$!\n";   "while attempting store\n";
                        }   }
       } else {      } else {
                           print $client "refused\n";   print $client "error: ".($!+0)
                       }      ." tie(GDBM) Failed ".
       "while attempting store\n";
       }
    } else {
       print $client "refused\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
        
       }
 # --------------------------------------------------------------------- restore  # --------------------------------------------------------------------- restore
                    } elsif ($userinput =~ /^restore/) {   } elsif ($userinput =~ /^restore/) {
                        my ($cmd,$udom,$uname,$namespace,$rid)      if(isClient) {
                           =split(/:/,$userinput);   my ($cmd,$udom,$uname,$namespace,$rid)
                        $namespace=~s/\//\_/g;      =split(/:/,$userinput);
                        $namespace=~s/\W//g;   $namespace=~s/\//\_/g;
                        chomp($rid);   $namespace=~s/\W//g;
                        my $proname=propath($udom,$uname);   chomp($rid);
                        my $qresult='';   my $proname=propath($udom,$uname);
       if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER,0640)) {   my $qresult='';
                   my $version=$hash{"version:$rid"};   my %hash;
                            $qresult.="version=$version&";   if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER(),0640)) {
                            my $scope;      my $version=$hash{"version:$rid"};
                            for ($scope=1;$scope<=$version;$scope++) {      $qresult.="version=$version&";
       my $vkeys=$hash{"$scope:keys:$rid"};      my $scope;
                               my @keys=split(/:/,$vkeys);      for ($scope=1;$scope<=$version;$scope++) {
                               my $key;   my $vkeys=$hash{"$scope:keys:$rid"};
                               $qresult.="$scope:keys=$vkeys&";   my @keys=split(/:/,$vkeys);
                               foreach $key (@keys) {   my $key;
      $qresult.="$scope:$key=".$hash{"$scope:$rid:$key"}."&";   $qresult.="$scope:keys=$vkeys&";
                               }                                     foreach $key (@keys) {
                            }      $qresult.="$scope:$key=".$hash{"$scope:$rid:$key"}."&";
    if (untie(%hash)) {   }                                  
               $qresult=~s/\&$//;      }
                               print $client "$qresult\n";      if (untie(%hash)) {
                            } else {   $qresult=~s/\&$//;
                               print $client "error:$!\n";   print $client "$qresult\n";
                            }      } else {
                        } else {   print $client "error: ".($!+0)
                            print $client "error:$!\n";      ." untie(GDBM) Failed ".
                        }      "while attempting restore\n";
       }
    } else {
       print $client "error: ".($!+0)
    ." tie(GDBM) Failed ".
    "while attempting restore\n";
    }
       } else  {
    Reply($client, "refused\n", $userinput);
          
       }
   # -------------------------------------------------------------------- chatsend
    } elsif ($userinput =~ /^chatsend/) {
       if(isClient) {
    my ($cmd,$cdom,$cnum,$newpost)=split(/\:/,$userinput);
    &chatadd($cdom,$cnum,$newpost);
    print $client "ok\n";
       } else {
    Reply($client, "refused\n", $userinput);
         
       }
   # -------------------------------------------------------------------- chatretr
    } elsif ($userinput =~ /^chatretr/) {
       if(isClient) {
    my 
       ($cmd,$cdom,$cnum,$udom,$uname)=split(/\:/,$userinput);
    my $reply='';
    foreach (&getchat($cdom,$cnum,$udom,$uname)) {
       $reply.=&escape($_).':';
    }
    $reply=~s/\:$//;
    print $client $reply."\n";
       } else {
    Reply($client, "refused\n", $userinput);
          
       }
 # ------------------------------------------------------------------- querysend  # ------------------------------------------------------------------- querysend
                    } elsif ($userinput =~ /^querysend/) {   } elsif ($userinput =~ /^querysend/) {
                        my ($cmd,$query,      if (isClient) {
    $custom,$customshow)=split(/:/,$userinput);   my ($cmd,$query,
        $query=~s/\n*$//g;      $arg1,$arg2,$arg3)=split(/\:/,$userinput);
        unless ($custom or $customshow) {   $query=~s/\n*$//g;
    print $client "".   print $client "".
        sqlreply("$hostid{$clientip}\&$query")."\n";      sqlreply("$clientname\&$query".
        }       "\&$arg1"."\&$arg2"."\&$arg3")."\n";
        else {      } else {
    print $client "".   Reply($client, "refused\n", $userinput);
        sqlreply("$hostid{$clientip}\&$query".        
  "\&$custom"."\&$customshow")."\n";      }
        }  
 # ------------------------------------------------------------------ queryreply  # ------------------------------------------------------------------ queryreply
                    } elsif ($userinput =~ /^queryreply/) {   } elsif ($userinput =~ /^queryreply/) {
                        my ($cmd,$id,$reply)=split(/:/,$userinput);       if(isClient) {
        my $store;   my ($cmd,$id,$reply)=split(/:/,$userinput); 
                        my $execdir=$perlvar{'lonDaemons'};   my $store;
                        if ($store=IO::File->new(">$execdir/tmp/$id")) {   my $execdir=$perlvar{'lonDaemons'};
    $reply=~s/\&/\n/g;   if ($store=IO::File->new(">$execdir/tmp/$id")) {
    print $store $reply;      $reply=~s/\&/\n/g;
    close $store;      print $store $reply;
    my $store2=IO::File->new(">$execdir/tmp/$id.end");      close $store;
    print $store2 "done\n";      my $store2=IO::File->new(">$execdir/tmp/$id.end");
    close $store2;      print $store2 "done\n";
    print $client "ok\n";      close $store2;
        }      print $client "ok\n";
        else {   }
    print $client "error:$!\n";   else {
        }      print $client "error: ".($!+0)
    ." IO::File->new Failed ".
    "while attempting queryreply\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
        
       }
   # ----------------------------------------------------------------- courseidput
    } elsif ($userinput =~ /^courseidput/) {
       if(isClient) {
    my ($cmd,$udom,$what)=split(/:/,$userinput);
    chomp($what);
    $udom=~s/\W//g;
    my $proname=
       "$perlvar{'lonUsersDir'}/$udom/nohist_courseids";
    my $now=time;
    my @pairs=split(/\&/,$what);
    my %hash;
    if (tie(%hash,'GDBM_File',"$proname.db",&GDBM_WRCREAT(),0640)) {
       foreach my $pair (@pairs) {
    my ($key,$value)=split(/=/,$pair);
    $hash{$key}=$value.':'.$now;
       }
       if (untie(%hash)) {
    print $client "ok\n";
       } else {
    print $client "error: ".($!+0)
       ." untie(GDBM) Failed ".
       "while attempting courseidput\n";
       }
    } else {
       print $client "error: ".($!+0)
    ." tie(GDBM) Failed ".
    "while attempting courseidput\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
          
       }
   # ---------------------------------------------------------------- courseiddump
    } elsif ($userinput =~ /^courseiddump/) {
       if(isClient) {
    my ($cmd,$udom,$since,$description)
       =split(/:/,$userinput);
    if (defined($description)) {
       $description=&unescape($description);
    } else {
       $description='.';
    }
    unless (defined($since)) { $since=0; }
    my $qresult='';
    my $proname=
       "$perlvar{'lonUsersDir'}/$udom/nohist_courseids";
    my %hash;
    if (tie(%hash,'GDBM_File',"$proname.db",&GDBM_READER(),0640)) {
       while (my ($key,$value) = each(%hash)) {
    my ($descr,$lasttime)=split(/\:/,$value);
    if ($lasttime<$since) { next; }
    if ($description eq '.') {
       $qresult.=$key.'='.$descr.'&';
    } else {
       my $unescapeVal = &unescape($descr);
       if (eval('$unescapeVal=~/\Q$description\E/i')) {
    $qresult.="$key=$descr&";
       }
    }
       }
       if (untie(%hash)) {
    chop($qresult);
    print $client "$qresult\n";
       } else {
    print $client "error: ".($!+0)
       ." untie(GDBM) Failed ".
       "while attempting courseiddump\n";
       }
    } else {
       print $client "error: ".($!+0)
    ." tie(GDBM) Failed ".
    "while attempting courseiddump\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
          
       }
 # ----------------------------------------------------------------------- idput  # ----------------------------------------------------------------------- idput
                    } elsif ($userinput =~ /^idput/) {   } elsif ($userinput =~ /^idput/) {
                        my ($cmd,$udom,$what)=split(/:/,$userinput);      if(isClient) {
                        chomp($what);   my ($cmd,$udom,$what)=split(/:/,$userinput);
                        $udom=~s/\W//g;   chomp($what);
                        my $proname="$perlvar{'lonUsersDir'}/$udom/ids";   $udom=~s/\W//g;
                        my $now=time;   my $proname="$perlvar{'lonUsersDir'}/$udom/ids";
                        {   my $now=time;
    my $hfh;   {
    if (      my $hfh;
                              $hfh=IO::File->new(">>$proname.hist")      if (
        ) { print $hfh "P:$now:$what\n"; }   $hfh=IO::File->new(">>$proname.hist")
        }   ) { print $hfh "P:$now:$what\n"; }
                        my @pairs=split(/\&/,$what);   }
                  if (tie(%hash,'GDBM_File',"$proname.db",&GDBM_WRCREAT,0640)) {   my @pairs=split(/\&/,$what);
                            foreach $pair (@pairs) {   my %hash;
        ($key,$value)=split(/=/,$pair);   if (tie(%hash,'GDBM_File',"$proname.db",&GDBM_WRCREAT(),0640)) {
                                $hash{$key}=$value;      foreach my $pair (@pairs) {
                            }   my ($key,$value)=split(/=/,$pair);
    if (untie(%hash)) {   $hash{$key}=$value;
                               print $client "ok\n";      }
                            } else {      if (untie(%hash)) {
                               print $client "error:$!\n";   print $client "ok\n";
                            }      } else {
                        } else {   print $client "error: ".($!+0)
                            print $client "error:$!\n";      ." untie(GDBM) Failed ".
                        }      "while attempting idput\n";
       }
    } else {
       print $client "error: ".($!+0)
    ." tie(GDBM) Failed ".
    "while attempting idput\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
          
       }
 # ----------------------------------------------------------------------- idget  # ----------------------------------------------------------------------- idget
                    } elsif ($userinput =~ /^idget/) {   } elsif ($userinput =~ /^idget/) {
                        my ($cmd,$udom,$what)=split(/:/,$userinput);      if(isClient) {
                        chomp($what);   my ($cmd,$udom,$what)=split(/:/,$userinput);
                        $udom=~s/\W//g;   chomp($what);
                        my $proname="$perlvar{'lonUsersDir'}/$udom/ids";   $udom=~s/\W//g;
                        my @queries=split(/\&/,$what);   my $proname="$perlvar{'lonUsersDir'}/$udom/ids";
                        my $qresult='';   my @queries=split(/\&/,$what);
                  if (tie(%hash,'GDBM_File',"$proname.db",&GDBM_READER,0640)) {   my $qresult='';
                            for ($i=0;$i<=$#queries;$i++) {   my %hash;
                                $qresult.="$hash{$queries[$i]}&";   if (tie(%hash,'GDBM_File',"$proname.db",&GDBM_READER(),0640)) {
                            }      for (my $i=0;$i<=$#queries;$i++) {
    if (untie(%hash)) {   $qresult.="$hash{$queries[$i]}&";
               $qresult=~s/\&$//;      }
                               print $client "$qresult\n";      if (untie(%hash)) {
                            } else {   $qresult=~s/\&$//;
                               print $client "error:$!\n";   print $client "$qresult\n";
                            }      } else {
                        } else {   print $client "error: ".($!+0)
                            print $client "error:$!\n";      ." untie(GDBM) Failed ".
                        }      "while attempting idget\n";
       }
    } else {
       print $client "error: ".($!+0)
    ." tie(GDBM) Failed ".
    "while attempting idget\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
          
       }
 # ---------------------------------------------------------------------- tmpput  # ---------------------------------------------------------------------- tmpput
                    } elsif ($userinput =~ /^tmpput/) {   } elsif ($userinput =~ /^tmpput/) {
                        my ($cmd,$what)=split(/:/,$userinput);      if(isClient) {
        my $store;   my ($cmd,$what)=split(/:/,$userinput);
                        $tmpsnum++;   my $store;
                        my $id=$$.'_'.$clientip.'_'.$tmpsnum;   $tmpsnum++;
                        $id=~s/\W/\_/g;   my $id=$$.'_'.$clientip.'_'.$tmpsnum;
                        $what=~s/\n//g;   $id=~s/\W/\_/g;
                        my $execdir=$perlvar{'lonDaemons'};   $what=~s/\n//g;
                        if ($store=IO::File->new(">$execdir/tmp/$id.tmp")) {   my $execdir=$perlvar{'lonDaemons'};
    print $store $what;   if ($store=IO::File->new(">$execdir/tmp/$id.tmp")) {
    close $store;      print $store $what;
    print $client "$id\n";      close $store;
        }      print $client "$id\n";
        else {   }
    print $client "error:$!\n";   else {
        }      print $client "error: ".($!+0)
    ."IO::File->new Failed ".
    "while attempting tmpput\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
       
       }
       
 # ---------------------------------------------------------------------- tmpget  # ---------------------------------------------------------------------- tmpget
                    } elsif ($userinput =~ /^tmpget/) {   } elsif ($userinput =~ /^tmpget/) {
                        my ($cmd,$id)=split(/:/,$userinput);      if(isClient) {
                        chomp($id);   my ($cmd,$id)=split(/:/,$userinput);
                        $id=~s/\W/\_/g;   chomp($id);
                        my $store;   $id=~s/\W/\_/g;
                        my $execdir=$perlvar{'lonDaemons'};   my $store;
                        if ($store=IO::File->new("$execdir/tmp/$id.tmp")) {   my $execdir=$perlvar{'lonDaemons'};
                            my $reply=<$store>;   if ($store=IO::File->new("$execdir/tmp/$id.tmp")) {
    print $client "$reply\n";      my $reply=<$store>;
                            close $store;      print $client "$reply\n";
        }      close $store;
        else {   }
    print $client "error:$!\n";   else {
        }      print $client "error: ".($!+0)
    ."IO::File->new Failed ".
    "while attempting tmpget\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
         
       }
   # ---------------------------------------------------------------------- tmpdel
    } elsif ($userinput =~ /^tmpdel/) {
       if(isClient) {
    my ($cmd,$id)=split(/:/,$userinput);
    chomp($id);
    $id=~s/\W/\_/g;
    my $execdir=$perlvar{'lonDaemons'};
    if (unlink("$execdir/tmp/$id.tmp")) {
       print $client "ok\n";
    } else {
       print $client "error: ".($!+0)
    ."Unlink tmp Failed ".
    "while attempting tmpdel\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
        
       }
 # -------------------------------------------------------------------------- ls  # -------------------------------------------------------------------------- ls
                    } elsif ($userinput =~ /^ls/) {   } elsif ($userinput =~ /^ls/) {
                        my ($cmd,$ulsdir)=split(/:/,$userinput);      if(isClient) {
                        my $ulsout='';   my $obs;
                        my $ulsfn;   my $rights;
                        if (-e $ulsdir) {   my ($cmd,$ulsdir)=split(/:/,$userinput);
  if (opendir(LSDIR,$ulsdir)) {   my $ulsout='';
                           while ($ulsfn=readdir(LSDIR)) {   my $ulsfn;
      my @ulsstats=stat($ulsfn);   if (-e $ulsdir) {
                              $ulsout.=$ulsfn.'&'.join('&',@ulsstats).':';      if(-d $ulsdir) {
                           }   if (opendir(LSDIR,$ulsdir)) {
                           closedir(LSDIR);      while ($ulsfn=readdir(LSDIR)) {
         }   undef $obs, $rights; 
        } else {   my @ulsstats=stat($ulsdir.'/'.$ulsfn);
                           $ulsout='no_such_dir';   #We do some obsolete checking here
                        }   if(-e $ulsdir.'/'.$ulsfn.".meta") { 
                        if ($ulsout eq '') { $ulsout='empty'; }      open(FILE, $ulsdir.'/'.$ulsfn.".meta");
                        print $client "$ulsout\n";      my @obsolete=<FILE>;
       foreach my $obsolete (@obsolete) {
           if($obsolete =~ m|(<obsolete>)(on)|) { $obs = 1; } 
    if($obsolete =~ m|(<copyright>)(default)|) { $rights = 1; }
       }
    }
    $ulsout.=$ulsfn.'&'.join('&',@ulsstats);
    if($obs eq '1') { $ulsout.="&1"; }
    else { $ulsout.="&0"; }
    if($rights eq '1') { $ulsout.="&1:"; }
    else { $ulsout.="&0:"; }
       }
       closedir(LSDIR);
    }
       } else {
    my @ulsstats=stat($ulsdir);
    $ulsout.=$ulsfn.'&'.join('&',@ulsstats).':';
       }
    } else {
       $ulsout='no_such_dir';
    }
    if ($ulsout eq '') { $ulsout='empty'; }
    print $client "$ulsout\n";
       } else {
    Reply($client, "refused\n", $userinput);
        
       }
   # ----------------------------------------------------------------- setannounce
    } elsif ($userinput =~ /^setannounce/) {
       if (isClient) {
    my ($cmd,$announcement)=split(/:/,$userinput);
    chomp($announcement);
    $announcement=&unescape($announcement);
    if (my $store=IO::File->new('>'.$perlvar{'lonDocRoot'}.
       '/announcement.txt')) {
       print $store $announcement;
       close $store;
       print $client "ok\n";
    } else {
       print $client "error: ".($!+0)."\n";
    }
       } else {
    Reply($client, "refused\n", $userinput);
          
       }
   # ------------------------------------------------------------------ Hanging up
    } elsif (($userinput =~ /^exit/) ||
    ($userinput =~ /^init/)) { # no restrictions.
       &logthis(
        "Client $clientip ($clientname) hanging up: $userinput");
       print $client "bye\n";
       $client->shutdown(2);        # shutdown the socket forcibly.
       $client->close();
       last;
   
   # ---------------------------------- set current host/domain
    } elsif ($userinput =~ /^sethost:/) {
       if (isClient) {
    print $client &sethost($userinput)."\n";
       } else {
    print $client "refused\n";
       }
   #---------------------------------- request file (?) version.
    } elsif ($userinput =~/^version:/) {
       if (isClient) {
    print $client &version($userinput)."\n";
       } else {
    print $client "refused\n";
       }
   #------------------------------- is auto-enrollment enabled?
                   } elsif ($userinput =~/^autorun:/) {
                       if (isClient) {
                           my ($cmd,$cdom) = split(/:/,$userinput);
                           my $outcome = &localenroll::run($cdom);
                           print $client "$outcome\n";
                       } else {
                           print $client "0\n";
                       }
   #------------------------------- get official sections (for auto-enrollment).
                   } elsif ($userinput =~/^autogetsections:/) {
                       if (isClient) {
                           my ($cmd,$coursecode,$cdom)=split(/:/,$userinput);
                           my @secs = &localenroll::get_sections($coursecode,$cdom);
                           my $seclist = &escape(join(':',@secs));
                           print $client "$seclist\n";
                       } else {
                           print $client "refused\n";
                       }
   #----------------------- validate owner of new course section (for auto-enrollment).
                   } elsif ($userinput =~/^autonewcourse:/) {
                       if (isClient) {
                           my ($cmd,$inst_course_id,$owner,$cdom)=split(/:/,$userinput);
                           my $outcome = &localenroll::new_course($inst_course_id,$owner,$cdom);
                           print $client "$outcome\n";
                       } else {
                           print $client "refused\n";
                       }
   #-------------- validate course section in schedule of classes (for auto-enrollment).
                   } elsif ($userinput =~/^autovalidatecourse:/) {
                       if (isClient) {
                           my ($cmd,$inst_course_id,$cdom)=split(/:/,$userinput);
                           my $outcome=&localenroll::validate_courseID($inst_course_id,$cdom);
                           print $client "$outcome\n";
                       } else {
                           print $client "refused\n";
                       }
   #--------------------------- create password for new user (for auto-enrollment).
                   } elsif ($userinput =~/^autocreatepassword:/) {
                       if (isClient) {
                           my ($cmd,$authparam,$cdom)=split(/:/,$userinput);
                           my ($create_passwd,$authchk);
                           ($authparam,$create_passwd,$authchk) = &localenroll::create_password($authparam,$cdom);
                           print $client &escape($authparam.':'.$create_passwd.':'.$authchk)."\n";
                       } else {
                           print $client "refused\n";
                       }
   #---------------------------  read and remove temporary files (for auto-enrollment).
                   } elsif ($userinput =~/^autoretrieve:/) {
                       if (isClient) {
                           my ($cmd,$filename) = split(/:/,$userinput);
                           my $source = $perlvar{'lonDaemons'}.'/tmp/'.$filename;
                           if ( (-e $source) && ($filename ne '') ) {
                               my $reply = '';
                               if (open(my $fh,$source)) {
                                   while (<$fh>) {
                                       chomp($_);
                                       $_ =~ s/^\s+//g;
                                       $_ =~ s/\s+$//g;
                                       $reply .= $_;
                                   }
                                   close($fh);
                                   print $client &escape($reply)."\n";
   #                                unlink($source);
                               } else {
                                   print $client "error\n";
                               }
                           } else {
                               print $client "error\n";
                           }
                       } else {
                           print $client "refused\n";
                       }
 # ------------------------------------------------------------- unknown command  # ------------------------------------------------------------- unknown command
                    } else {  
                        # unknown command   } else {
                        print $client "unknown_cmd\n";      # unknown command
                    }      print $client "unknown_cmd\n";
 # ------------------------------------------------------ client unknown, refuse   }
        }  # -------------------------------------------------------------------- complete
             } else {   alarm(0);
         print $client "refused\n";   &status('Listening to '.$clientname." ($keymode)");
                 &logthis("<font color=blue>WARNING: "      }
                 ."Rejected client $clientip, closing connection</font>");  # --------------------------------------------- client unknown or fishy, refuse
             }                 } else {
             &logthis("<font color=red>CRITICAL: "      print $client "refused\n";
                     ."Disconnect from $clientip ($hostid{$clientip})</font>");      $client->close();
       &logthis("<font color='blue'>WARNING: "
        ."Rejected client $clientip, closing connection</font>");
    }
       }             
       
 # =============================================================================  # =============================================================================
         }  
           
         # tidy up gracefully and finish      &logthis("<font color='red'>CRITICAL: "
        ."Disconnect from $clientip ($clientname)</font>");    
       
           
         # this exit is VERY important, otherwise the child will become      # this exit is VERY important, otherwise the child will become
         # a producer of more and more children, forking yourself into      # a producer of more and more children, forking yourself into
         # process death.      # process death.
         exit;      exit;
       
   }
   
   
   #
   #   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, $domain, $user, $authtype) = @_;
   
       # 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" ;
    &logthis("system $execdir/lchtmldir $userhome $user $authtype");
    system("$execdir/lchtmldir $userhome $user $authtype");
       }
   }
   #
   #   GetAuthType - Determines the authorization type of a user in a domain.
   
   #     Returns the authorization type or nouser if there is no such user.
   #
   sub GetAuthType 
   {
   
       my ($domain, $user)  = @_;
   
       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;
       my $sh;
       if ($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,$udom,$uname)=@_;
       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;
       }
       my @participants=();
       my $cutoff=time-60;
       if (tie(%hash,'GDBM_File',"$proname/nohist_inchatroom.db",
       &GDBM_WRCREAT(),0640)) {
           $hash{$uname.':'.$udom}=time;
           foreach (sort keys %hash) {
       if ($hash{$_}>$cutoff) {
    $participants[$#participants+1]='active_participant:'.$_;
               }
           }
           untie %hash;
       }
       return (@participants,@entries);
   }
   
   sub chatadd {
       my ($cdom,$cname,$newchat)=@_;
       my %hash;
       my $proname=&propath($cdom,$cname);
       my @entries=();
       my $time=time;
       if (tie(%hash,'GDBM_File',"$proname/nohist_chatroom.db",
       &GDBM_WRCREAT(),0640)) {
    @entries=map { $_.':'.$hash{$_} } sort keys %hash;
    my ($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;
       }
       {
    my $hfh;
    if ($hfh=IO::File->new(">>$proname/chatroom.log")) { 
       print $hfh "$time:".&unescape($newchat)."\n";
    }
     }      }
 }  }
   
   sub unsub {
       my ($fname,$clientip)=@_;
       my $result;
       my $unsubs = 0; # Number of successful unsubscribes:
   
   
       # An old way subscriptions were handled was to have a 
       # subscription marker file:
   
       Debug("Attempting unlink of $fname.$clientname");
       if (unlink("$fname.$clientname")) {
    $unsubs++; # Successful unsub via marker file.
       } 
   
       # The more modern way to do it is to have a subscription list
       # file:
   
       if (-e "$fname.subscription") {
    my $found=&addline($fname,$clientname,$clientip,'');
    if ($found) { 
       $unsubs++;
    }
       } 
   
       #  If either or both of these mechanisms succeeded in unsubscribing a 
       #  resource we can return ok:
   
       if($unsubs) {
    $result = "ok\n";
       } else {
    $result = "not_subscribed\n";
       }
   
       return $result;
   }
   
   sub currentversion {
       my $fname=shift;
       my $version=-1;
       my $ulsdir='';
       if ($fname=~/^(.+)\/[^\/]+$/) {
          $ulsdir=$1;
       }
       my ($fnamere1,$fnamere2);
       # remove version if already specified
       $fname=~s/\.\d+\.(\w+(?:\.meta)*)$/\.$1/;
       # get the bits that go before and after the version number
       if ( $fname=~/^(.*\.)(\w+(?:\.meta)*)$/ ) {
    $fnamere1=$1;
    $fnamere2='.'.$2;
       }
       if (-e $fname) { $version=1; }
       if (-e $ulsdir) {
    if(-d $ulsdir) {
       if (opendir(LSDIR,$ulsdir)) {
    my $ulsfn;
    while ($ulsfn=readdir(LSDIR)) {
   # see if this is a regular file (ignore links produced earlier)
       my $thisfile=$ulsdir.'/'.$ulsfn;
       unless (-l $thisfile) {
    if ($thisfile=~/\Q$fnamere1\E(\d+)\Q$fnamere2\E$/) {
       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.$clientname") {&unsub($fname,$clientip);}
    my $now=time;
    my $found=&addline($fname,$clientname,$clientip,
      "$clientname:$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') {
    {
       #
       #  Don't allow the creation of privileged accounts!!! that would
       #  be real bad!!!
       #
       my $uid = getpwnam($uname);
       if((defined $uid) && ($uid == 0)) {
    &logthis(">>>Attempted to create privilged account blocked");
    return "no_priv_account_error\n";
       }
   
       my $execpath="$perlvar{'lonDaemons'}/"."lcuseradd";
       {
    &Debug("Executing external: ".$execpath);
    &Debug("user  = ".$uname.", Password =". $npass);
    my $se = IO::File->new("|$execpath > $perlvar{'lonDaemons'}/logs/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;
   }
   
   sub sethost {
       my ($remotereq) = @_;
       my (undef,$hostid)=split(/:/,$remotereq);
       if (!defined($hostid)) { $hostid=$perlvar{'lonHostID'}; }
       if ($hostip{$perlvar{'lonHostID'}} eq $hostip{$hostid}) {
    $currenthostid  =$hostid;
    $currentdomainid=$hostdom{$hostid};
    &logthis("Setting hostid to $hostid, and domain to $currentdomainid");
       } else {
    &logthis("Requested host id $hostid not an alias of ".
    $perlvar{'lonHostID'}." refusing connection");
    return 'unable_to_set';
       }
       return 'ok';
   }
   
   sub version {
       my ($userinput)=@_;
       $remoteVERSION=(split(/:/,$userinput))[1];
       return "version:$VERSION";
   }
   
   #There is a copy of this in lonnet.pm
   sub userload {
       my $numusers=0;
       {
    opendir(LONIDS,$perlvar{'lonIDsDir'});
    my $filename;
    my $curtime=time;
    while ($filename=readdir(LONIDS)) {
       if ($filename eq '.' || $filename eq '..') {next;}
       my ($mtime)=(stat($perlvar{'lonIDsDir'}.'/'.$filename))[9];
       if ($curtime-$mtime < 1800) { $numusers++; }
    }
    closedir(LONIDS);
       }
       my $userloadpercent=0;
       my $maxuserload=$perlvar{'lonUserLoadLim'};
       if ($maxuserload) {
    $userloadpercent=100*$numusers/$maxuserload;
       }
       $userloadpercent=sprintf("%.2f",$userloadpercent);
       return $userloadpercent;
   }
   
   
   # ----------------------------------- 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 *
   
   SIGUSR2
   
   Parent Signal assignment:
       $SIG{USR2} = \&UpdateHosts
   
   Child signal assignment:
       NONE
   
   
   =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 pushtable
   
   Pushes a file in /home/httpd/lonTab directory.  Currently limited to:
   hosts.tab and domain.tab. The old file is copied to  *.tab.backup but
   must be restored manually in case of a problem with the new table file.
   pushtable requires that the request be encrypted and validated via
   ValidateManager.  The form of the command is:
   enc:pushtable tablename <tablecontents> \n
   where pushtable, tablename and <tablecontents> will be encrypted, but \n is a 
   cleartext newline.
   
   =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
Removed from v.1.46  
changed lines
  Added in v.1.198

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